Dissertations / Theses: 'Biological Crises'

1

Guillam, Elvis. "Les deux crises biologiques de la fin du Dévonien : les ostracodes marqueurs des variations paléoenvironnementales et des relations paléobiogéographiques." Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS157.pdf.

Full text

Abstract:

Au cours des temps géologiques, la vie s'est grandement complexifiée et a connu de nombreuses et importantes variations de biodiversité. Parmi les déclins du Phanérozoïque (-541.0 ± 1.0 Ma à actuel), cinq grandes crises sont considérées comme majeures. L'une d'elles, appelée événement Kellwasser, marque la limite entre le Frasnien et le Famennien (-372 ± 1.6 Ma). Elle est suivie à la transition Dévonien-Carbonifère par un second événement de premier ordre, appelé événement Hangenberg. Ces événements de nature anoxique auraient été déclenchés par les importants changements climatiques caractérisant le Dévonien supérieur et les variations eustatiques associées. Les ostracodes, microcrustacés essentiellement benthiques, sont connus pour leur registre fossile continu à travers tous les événements d'extinction ainsi que pour leurs capacités d'adaptation et sont de bons marqueurs des variations des paramètres environnementaux. Ce sont ainsi d'excellents outils pour comprendre les déclins de biodiversité lors des crises biologiques et la récupération des écosystèmes après ces déclins. L'important travail de taxinomie réalisée sur le matériel de la coupe de Blue Snake (Guizhou, Chine du Sud) a permis de quantifier de manière précise et pour la première fois les variations de diversité chez les ostracodes en lien avec l'événement Hangenberg et de caractériser le paléoenvironnement et ses variations à la transition Dévonien-Carbonifère. Sur cette coupe, le taux d'extinction spécifique est estimé à 44%. Sur cet intervalle, le paléoenvironnement correspondait à une plateforme continentale ayant subi une transgression, avec le passage d'un environnement littoral peu profond au Famennien à un milieu offshore au Tournaisien. Les révisions réalisées dans le cadre de cette thèse ont également permis de quantifier l'impact des événements Kellwasser et Hangenberg sur les ostracodes. Ces crustacés ont été grandement affectés à bas niveaux taxinomiques (espèces et genres) par ces deux événements avec des taux d'extinction spécifique estimé à 80% pour l'événement Kellwasser et 69% pour l'événement Hangenberg. Les niveaux supra-génériques ont été très peu touchés. Ces événements ont affecté la diversité de ces organismes dans divers paléoenvironnements (plateforme continentale interne et externe et milieux profonds) et dans de nombreuses zones paléogéographiques, démontrant le caractère global de ces extinctions. La récupération des faunes d'ostracodes à la suite de ces événements a certainement été influencée par les variations des paramètres environnementaux et climatiques. Elle est principalement caractérisée par la diversification de taxons cosmopolites, notamment au sein des Bairdiidae et des Bairdiocyprididae. Les Paraparchitidae se sont également diversifiés au cours du Tournaisien (Carbonifère inférieur). La distribution paléobiogéographique des ostracodes sur l'intervalle Frasnien-Tournaisien suggère que quatre facteurs principaux influencent leur répartition. Le climat, plus particulièrement la température, semble avoir influencé la distribution paléobiogéographique des ostracodes, la répartition des communautés identifiées suivant grossièrement la répartition latitudinale des climats. La circulation océanique pourrait expliquer les affinités observées entre les faunes provenant de zones paléogéographiques relativement éloignées. Le niveau marin et ses variations ainsi que la dynamique des plaques tectoniques semblent quant à eux avoir surtout influencé la connectivité globale entre les faunes des différentes zones paléogéographiques à l'échelle globale
Over geological time, life has greatly increased in complexity and has undergone many important variations in biodiversity. Among the declines occurring during the Phanerozoic (541.0 ± 1.0 Ma to present), five major crises are considered as major. One of them, called the Kellwasser event, marks the Frasnian-Famennian boundary (-372 ± 1.6 Ma). It is followed at the Devonian-Carboniferous transition by a second first-order event, called Hangenberg event. These anoxic events have been triggered by important climatic changes and the associated eustatic variations characterizing the Late Devonian. Ostracods, essentially benthic microcrustaceans, are known for their continuous fossil record through all extinction events as well as for their adaptive capacities and are good markers of environmental changes. They are thus excellent tools for understanding biodiversity declines during biological crises and the recovery of ecosystems after these declines. The important taxonomic work realized on the material from the Blue Snake section (Guizhou, South China) allowed to quantify precisely and for the first time the diversity variations among ostracods related to the Hangenberg event and to characterize the paleoenvironment and its variations at the Devonian-Carboniferous transition. In this section, the specific extinction rate is estimated at 44%. Over this interval, the paleoenvironment corresponded to a continental shelf that underwent transgression, with the transition from a nearshore shallow environment in the Famennian to a deeper and more open offshore environment in the Tournaisian. The revisions realized during this thesis also allowed to quantify the impact of both Kellwasser and Hangenberg events on ostracods. These crustaceans were greatly affected at low taxonomic levels (species and genera) by both events with specific extinction rates estimated at 80% for the Kellwasser event and 69% for the Hangenberg event. The supra-generic levels were only slightly affected. These events affected the diversity of these crustaceans in various paleoenvironments (nearshore and outer-shelf and bathyal environments) and in numerous geographic areas, demonstrating the global character of these extinctions. The recovery of ostracod faunas following these events was certainly influenced by variations in environmental and climatic parameters. It is mainly characterized by the diversification of cosmopolitan taxa, notably within the Bairdiidae and Bairdiocyprididae. The Paraparchitidae also diversified during the Tournaisian (Lower Carboniferous). The palaeobiogeographic distribution of ostracods over the Frasnian-Tournaisian interval suggests that four main factors influence their repartition. Climate, especially temperature, seems to have influenced the palaeobiogeographic distribution of ostracods, with the identified communities roughly following the latitudinal distribution of climates. Oceanic circulation could explain the affinities observed between faunas from relatively distant palaeogeographical areas. The sea level and its variations as well as the tectonic plates dynamic had mainly influenced the global connectivity between the faunas from the different palaeogeographical areas on a global scale

APA, Harvard, Vancouver, ISO, and other styles

2

Lynteris, Christos. "Epidemic events : state-formation, class struggle and biopolitics in three epidemic crises of modern China." Thesis, University of St Andrews, 2010. http://hdl.handle.net/10023/2150.

Full text

Abstract:

Based on extended research on Chinese medical and epidemiological archival material dating back to the beginning of the 20th century, and on six months of internship in epidemiology in Beijing’s Medical School and in Haidian District’s Centre of Disease Control and Prevention, this thesis explores the conjunction of three major epidemiological crises in modern Chinese history with processes of State formation: the 1911 Manchurian pneumonic plague, the 1952 germ-warfare, and the 2003 SARS outbreak. Analysing the three crises as Events in line with Alain Badiou’s epistemology it seeks to establish how different strategies of governmental fidelity to the imagined cause of each crisis have led to distinct modes of organisation and valorisation of the social: Republican China and its decline to fascism; the clash between professional revolutionaries and technocrats in Maoist China; and the emergence of the “Harmonious Society” of mass exploitation and repression today. This conjunction between State formation and epidemiological Events is explored with the use of Foucault’s genealogical method in a quest for a historical materialist approach that posits at its epicentre processes of class composition, decomposition and recomposition, and their contested enclosure by the governmental apparati of capture. The present thesis thus examines the three major epidemiological crises of modern China as forming grounds for biopolitical strategies that give rise to modes of subjectivation and circuits of debt/guilt within the context of the class struggle. And at the same time, it aims to create a new field of investigation for anthropology: the relation of State and Event, from a viewpoint that contests the accepted relation of event and structure expounded by Marshall Sahlins, proposing as the main object of this investigation the conjunction between necessity and will that can never be reduced either to the naturalism of historical determinism, nor to the culturalism of subjective contingency.

APA, Harvard, Vancouver, ISO, and other styles

3

Siebel, Anna Maria. "O papel do sistema purin?rgico e da via de sinaliza??o TOR em crises convulsivas e estresse oxidativo." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2013. http://tede2.pucrs.br/tede2/handle/tede/5474.

Full text

Abstract:

Made available in DSpace on 2015-04-14T14:51:28Z (GMT). No. of bitstreams: 1 451454.pdf: 6697842 bytes, checksum: 890c954db41088b36538c3133a7c2606 (MD5) Previous issue date: 2013-09-27
Epilepsy, characterized by the occurrence of spontaneous and recurrent seizures, is one of the main chronic neurological diseases, affecting around 1% of the world's population. Adenosine is an endogenous modulator of neuronal excitability and has anticonvulsant properties. Thus, the modulation of adenosinergic signalling pathway may presents important effects on epilepsy. In this study we characterize different aspects of the adenosinergic signaling in a model of seizures induced by pentylenetetrazole (PTZ) in zebrafish. In this study we also analyzed the effect of different modulators of adenosinergic signaling on controlling the development of seizures. Our results showed that the activation of type A1 adenosine receptors has an important role in controlling seizures in zebrafish. Furthermore, we observed that ecto-5?-nucleotidase and ADA enzymes, in addition to nucleoside transporters, are directly involved in controlling extracellular adenosine levels and, consequently, in controlling the development of seizures in this teleost. In addition, we clarified the occurrence of controversial data related to the mTOR signaling pathway in oxidative stress. Previous studies have suggested the activation of this pathway in oxidative stress based on the misinterpretation of the phosphorylation of RSK and MSK proteins through the antibody anti-phospho-Thr389-S6K, in addition to protein S6 phosphorylation, regulated by the MAPK signaling pathway in this case. Therefore, these findings might contribute for a better understanding about the signaling pathways involved in the mechanisms of seizure control and represents na alternative for the development of antiepileptic drugs, increasing the therapeutic options in epilepsia. Our results may also contribute to future studies on the characterization and modulation of TOR signaling pathway in zebrafish.
A epilepsia, caracterizada pela ocorr?ncia de crises convulsivas espont?neas e recorrentes, ? umas das principais doen?as neurol?gicas cr?nicas, afetando em torno de 1% da popula??o mundial. A adenosina ? um modulador end?geno da excitabilidade neuronal e apresenta propriedades anticonvulsivantes. Sendo assim, a modula??o da via de sinaliza??o adenosin?rgica pode apresentar um efeito importante na epilepsia. Neste estudo, n?s caracterizamos diferentes aspectos da sinaliza??o adenosin?rgica em modelo de crise convulsiva induzida por pentilenotetrazol (PTZ) em peixe-zebra. Nossos resultados demonstram um aumento nas atividades da adenosina desaminase (ADA), respons?vel pela desamina??o de adenosina em inosina, logo ap?s uma crise convulsiva. Al?m disso, foi observado que os f?rmacos antiepil?pticos gabapentina, fenito?na e ?cido valpr?ico preveniram o efeito estimulat?rio promovido pelo PTZ sobre as atividades da adenosina desaminase. Neste estudo, tamb?m analisamos o efeito de diferentes moduladores da sinaliza??o adenosin?rgica no controle do desenvolvimento de convuls?es induzidas por PTZ. Nossos resultados demonstraram que a ativa??o de receptores de adenosina do tipo A1 tem importante participa??o no controle de crises convulsivas em peixe-zebra. Al?m disso, observamos que as enzimas ecto-5?-nucleotidase e ADA, al?m dos transportadores de nucleos?deos est?o diretamente envolvidos no controle dos n?veis extracelulares de adenosina e, consequentemente, no controle do desenvolvimento de crises convulsivas neste tele?steo. Al?m disso, esclarecemos a ocorr?ncia de dados controversos relacionados ? via de sinaliza??o mTOR em estresse oxidativo. Estudos sugeriram a ativa??o desta via em estresse oxidativo baseados na interpreta??o equivocada da fosforila??o das prote?nas RSK e MSK pelo anticorpo anti-fosfo-Thr389-S6K, al?m da fosforila??o da prote?na S6, regulada neste caso pela via de sinaliza??o MAPK. Este estudo pode contribuir para um maior entendimento das vias de sinaliza??o envolvidas nos mecanismos de controle de crises convulsivas e representar uma alternativa para o desenvolvimento de f?rmacos antiepil?pticos, aumentando as op??es terap?uticas em epilepsia. Nossos resultados tamb?m podem contribuir para futuros estudos referentes ? caracteriza??o e modula??o da via de sinaliza??o TOR em peixe-zebra.

APA, Harvard, Vancouver, ISO, and other styles

4

Siebel, Anna Maria. "Efeito de crises convulsivas e f?rmacos antiepil?pticos em par?metros neuroqu?micos e moleculares em peixe zebra (Danio rerio)." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2011. http://tede2.pucrs.br/tede2/handle/tede/5392.

Full text

Abstract:

Made available in DSpace on 2015-04-14T14:51:06Z (GMT). No. of bitstreams: 1 431137.pdf: 15580738 bytes, checksum: 8de463b0a32f5623e6e47a0d1d0edad2 (MD5) Previous issue date: 2011-03-10
A epilepsia ? uma desordem neuronal caracterizada pela ocorr?ncia de convuls?es espont?neas e recorrentes. Essa patologia e seu tratamento interferem em diversos mecanismos neurol?gicos. O sistema purin?rgico ? uma importante rota de sinaliza??o celular que emprega nucleot?deos e nucleos?deos extracelulares como mol?culas sinalizadoras. O neurotransmissor ATP atua atrav?s de receptores do tipo P2Y, acoplados ? prote?na G e receptores P2X, que s?o ionotr?picos. A degrada??o do ATP extracelular e a conseq?ente produ??o de adenosina ? realizada por uma fam?lia de enzimas de superf?cie celular conhecidas como ectonucleotidases, que inclui as NTPDases (nucleos?deo trifosfato difosfoidrolases) e a ecto-5?-nucleotidase. A adenosina ? um neuromodulador que atua atrav?s da ativa??o de receptores metabotr?picos do tipo P1 (A1, A2A, A2B, A3). Esse nucleos?deo pode agir como um anticonvulsivante end?geno, principalmente via receptores A1. As NTPDases hidrolisam nucleot?deos tri- e difosfatados originando a adenosina, que ? hidrolisada pela adenosina deaminase (ADA). Assim, as NTPDases, ecto-5 -nucleotidase e ADA controlam os n?veis de nucleot?deos e nucleos?deos, modulando o sistema purin?rgico. No sistema colin?rgico, a acetilcolina (ACh) atua atrav?s de receptores muscar?nicos (metabotr?picos) e nicot?nicos (ionotr?picos). Sua a??o ? encerrada atrav?s de sua hidr?lise catalisada pela acetilcolinesterase (AChE). O peixe zebra ? um pequeno tele?steo de ?gua doce que vem sendo amplamente utilizado como modelo experimental em pesquisa. Estudos mostram que o peixe zebra pode ser uma ferramenta importante para o entendimento da epilepsia, bem como para o screening de f?rmacos antiepil?pticos. Considerando que as sinaliza??es purin?rgica e colin?rgica t?m importante participa??o no sistema nervoso e que essas vias de neurotransmiss?o est?o identificadas e caracterizadas em peixe zebra, o objetivo desse estudo foi avaliar nesse tele?steo o efeito de convuls?es induzidas por pentilenotetrazol (PTZ), bem como de f?rmacos antiepil?pticos na atividade das ectonucleotidases, ADA e AChE, enzimas essenciais na modula??o destas vias de sinaliza??o. Foram avaliados os efeitos in vitro da carbamazepina, fenito?na e gabapentina na atividade das ectonucleotidases e AChE. A carbamazepina diminuiu a hidr?lise de ATP e tamb?m de ACh. A fenito?na aumentou a hidr?lise de AMP e a gabapentina n?o provocou altera??es enzim?ticas. Foi analisado tamb?m o efeito de crises convulsivas induzidas por PTZ na atividade das ectonucleotidases e da ADA. Os resultados n?o mostraram altera??es nas ectonucleotidases e ADA nas fra??es extracelular e intracelular, respectivamente. No entanto, a atividade extracelular da ADA foi inibida em animais expostos ao PTZ. As an?lises mostraram que os f?rmacos antiepil?pticos podem influenciar a atividade das enzimas envolvidas na degrada??o extracelular de nucleot?deos, bem como na hidr?lise de ACh. Al?m disso, a diminui??o na degrada??o de adenosina observada em nosso modelo de estudo pode sugerir a participa??o da ADA na modula??o nos n?veis de adenosina durante as crises convulsivas em peixe zebra

APA, Harvard, Vancouver, ISO, and other styles

5

Schwengber, Solange Pereira. "Utiliza??o de marcadores de cromossomo Y como ferramenta visando a elucida??o de casos de crimes sexuais na gen?tica forense." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2008. http://tede2.pucrs.br/tede2/handle/tede/5324.

Full text

Abstract:

Made available in DSpace on 2015-04-14T14:50:52Z (GMT). No. of bitstreams: 1 405027.pdf: 58857 bytes, checksum: 3137651cc6ea0e3ba8d2644d92086797 (MD5) Previous issue date: 2008-08-28
Marcadores moleculares de cromossomo Y s?o essenciais ? per?cia em gen?tica forense. Os marcadores moleculares STR (Short Tandem Repeats) espec?ficos para o cromossomo Y s?o amplamente utilizados nos Laborat?rios de Per?cias. Entretanto, n?o havia dados estat?sticos pr?prios do Estado do Rio Grande do Sul, implicando na utiliza??o de bancos de dados alternativos (brasileiro e europeu). Assim, a forma??o de um banco de dados de hapl?tipos, pr?prio da popula??o do RS, com os perfis do cromossomo Y, permitiria a emiss?o de Laudos Periciais com informa??es estat?sticas mais fidedignas. Neste trabalho foram tipados 255 indiv?duos n?o aparentados, pertencentes a sete mesoregi?es do estado do Rio Grande do Sul. Foram colhidas amostras de sangue ou saliva a partir das quais foi feita a extra??o de DNA, seguida da amplifica??o dos 17 loci do cromossomo Y atrav?s do kit Y-STRs (AmpF=iSTR? YfilerTM - Applied Biosystems). Os produtos de amplifica??o foram analisados no ABI PRISM? 3100 Avant Genetic Analyzer (Applied Biosystems). Na an?lise dos dados foram identificados 247 hapl?tipos, dos quais 239 ?nicos e 8 foram encontrados em dois indiv?duos, cada. A diversidade haplot?pica de Y-STRs da popula??o do Rio Grande do Sul foi de 99,98% e o poder de discrimina??o de 96,86%. As dist?ncias gen?ticas mostraram que a popula??o do RS, como um todo, n?o ? significativamente diferente das amostras do Brasil, Rio de Janeiro e Argentina; ? marginalmente diferente de S?o Paulo, It?lia e do Norte de Portugal; mais distante da Espanha, regi?o Amaz?nica e Alemanha; e muito distante da amostra de nativos sul-americanos. Quando os dados do RS foram comparados por mesoregi?o, alguns pares apresentaram diferen?a significativa entre si, de acordo com a hist?ria da imigra??o, sendo a Mesoregi?o Centro Oriental Rio-Grandense a mais diferente. Por?m, nenhuma regi?o apresentou diferen?a significativa em rela??o ? popula??o brasileira.

APA, Harvard, Vancouver, ISO, and other styles

6

Lopes, Rodrigo Pestana. "Efeitos neuroimunoend?crinos do estresse por abuso f?sico ou neglig?ncia na inf?ncia em mulheres com depress?o maior." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2011. http://tede2.pucrs.br/tede2/handle/tede/5405.

Full text

Abstract:

Made available in DSpace on 2015-04-14T14:51:10Z (GMT). No. of bitstreams: 1 431890.pdf: 1738256 bytes, checksum: 1de40e064eb7209fe3bee4e61b0b071b (MD5) Previous issue date: 2011-03-28
INTRODU??O: Sabe-se que experi?ncias traum?ticas na inf?ncia podem levar ao surgimento de dist?rbios psiqui?tricos na vida adulta, incluindo a depress?o maior (DM). Contudo, ainda se desconhece o grau de altera??es biol?gicas que eventos estressores traum?ticos vivenciados na inf?ncia podem produzir em indiv?duos com depress?o. OBJETIVOS: Investigar par?metros neuroend?crinos e imunol?gicos em mulheres adultas deprimidas, com sintomas de Estresse P?s- Traum?tico (TEPT) e hist?ria de abuso e neglig?ncia infantil (ANI). M?TODOS: Trinta e oito mulheres com DM com ou sem hist?ria de abuso e neglig?ncia infantil e sintomas de TEPT e 19 mulheres saud?veis fizeram parte da coleta de dados desta tese. Os resultados deste trabalho foram divididos em 3 artigos cient?ficos originais e uma revis?o do tema. As avalia??es inclu?ram dosagens de n?veis salivares de cortisol e de sulfato de dehidroepiandrosterona (DHEAS) por radioimunoensaio; a mitog?nese induzida de linf?citos T de sangue perif?rico foi avaliada por ensaio colorim?trico, bem como a sensibilidade de linf?citos T a moduladores sint?ticos (dexametasona) e naturais (epinefrina e sulfato de dehidroepiandrosterona); a secre??o de citocinas de perfis Th1/Th2 (IL-2, IL-4, IL-6, IL-10, TNF-a, IFN-g) por c?lulas mononucleares foi identificada por citometria de fluxo; e os n?veis plasm?ticos de BDNF, al?m de TNF-a e seus receptores sol?veis (sTNFR1 e sTNFR2), foram identificados por ELISA. RESULTADOS: Pacientes deprimidas com ou sem trauma infantil apresentaram n?veis reduzidos e semelhantes de cortisol salivar e DHEAS em paralelo com prolifera??o reduzida de linf?citos T. As c?lulas mononucleares de sangue perif?rico das pacientes deprimidas foram menos sens?veis ? dexametasona (DEX) ou epinefrina (EPI) e produziram n?veis significativamente reduzidos de IL-2, IL-4 e TNF-a quando comparadas ao grupo de controles. As pacientes deprimidas apresentaram ainda n?veis plasm?ticos elevados de sTNFR1 e sTNFR2, al?m de redu??o dos 6 n?veis de BDNF. CONCLUS?ES: Embora muitas altera??es biol?gicas tenham sido identificadas nas mulheres com DM em rela??o ao grupo de mulheres saud?veis, poucas foram correlacionadas com hist?ria de abuso e neglig?ncia na inf?ncia. Sendo assim, de uma forma geral, conclui-se que a hist?ria de abuso e neglig?ncia na inf?ncia n?o impacta significativamente as altera??es neuroend?crinas e imunol?gicas apresentadas por pacientes com depress?o maior

APA, Harvard, Vancouver, ISO, and other styles

7

Gusso, Darlan. "Efeito do Piriproxifeno sobre o desenvolvimento, par?metros comportamentais e end?crinos em larvas e adultos de Peixe-zebra (Danio rerio)." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/7950.

Full text

Abstract:

Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-04-04T12:33:24Z No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5)
Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-04-19T16:26:33Z (GMT) No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5)
Made available in DSpace on 2018-04-19T16:43:13Z (GMT). No. of bitstreams: 1 DARLAN_GUSSO_DIS.pdf: 1507228 bytes, checksum: e2389f511956dbb64bb7b767d8f73e40 (MD5) Previous issue date: 2018-02-21
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Mosquitoes are responsible for the transmission of various pathogens. Over the past three years, the world has witnessed epidemics affecting all age groups, such as dengue fever, yellow fever, chikungunya and zika virus. To control and eliminate Aedes vectors responsible for the transmission of these diseases, it is necessary to use larvicides and insecticides such as pyriproxyfen. Pyriproxyfen is a larvicide used to control mosquitoes, mainly of the genus Aedes. This study evaluated the effects of pyriproxyfen on survival, morphology, behavior, and endocrine parameters at different stages of zebrafish development. We have demonstrated that pyriproxyfen can cause changes in the survival rate, behavior and morphology of exposed larvae, adults exposed at the larval stage, and adult offspring of exposed parents. Larvae exposed to pyriproxyfen for 1-96 hpf (hours post-fertilization) showed a decrease in survival rate, heart rate 3 dpf (days post-fertilization), and body length at 5 and 8 dpf. The distance traveled and the mean velocities of the exposed larvae were reduced in comparison to the vehicle group (1% DMSO). Therefore, pyriproxyfen changes the morphology and behavior of zebrafish in early stages of development and may affect the next generations. However, when the exposed larvae were maintained until the adult stage (6 months), we did not observe differences in locomotor parameters. Parental exposure to pyriproxyfen induced decrease in locomotion of zebrafish adult offspring as well as an anxiolytic-like behavior. We also tested pyriproxyfen exposure for 96 hours in adult zebrafish and the locomotion, anxiety, memory and endocrine parameters were analyzed as well as the gene expression of the glucocorticoid receptor (GR) and corticotropin-releasing factor (CRF). These results showed that there was no significant difference in locomotion, anxiety and endocrine parameters. In addition, there was an impairment of habituation memory in adult zebrafish exposed to pyriproxyfen. Therefore, it is important to control the use of larvicides due to their toxic effects on non-target species. Our findings demonstrated the importance of studies related to the use of larvicides, since they are potential causes of morphological and behavioral alterations in aquatic species, such as zebrafish.
Mosquitos s?o respons?veis pela transmiss?o de v?rios agentes patog?nicos. Nos ?ltimos tr?s anos, o mundo testemunhou epidemias que afetam todas as faixas et?rias, tais como dengue, febre amarela, chikungunya e zika v?rus. Para controlar e eliminar vetores do g?nero Aedes, respons?vel pela transmiss?o destas doen?as, ? necess?rio usar larvicidas e inseticidas como o piriproxifeno. O piriproxifeno ? um larvicida usado para eliminar mosquitos, principalmente do g?nero Aedes. Este estudo avaliou os efeitos do piriproxifeno sobre a sobreviv?ncia, morfologia, comportamento e par?metros end?crinos em diferentes est?gios de desenvolvimento de peixe-zebra. N?s demonstramos que o piriproxifeno pode causar altera??es na taxa de sobreviv?ncia, comportamento e morfologia de larvas expostas, adultos expostos no est?gio larval e descendentes adultos de pais expostos. As larvas expostas ao piriproxifeno durante 1-96 hpf (horas p?s-fertiliza??o) mostraram uma diminui??o na taxa de sobreviv?ncia, frequ?ncia card?aca 3 dpf e comprimento corporal nos 5 e 8 dpf (dias p?s- fertiliza??o). A dist?ncia percorrida e a velocidade m?dia das larvas expostas foram reduzidas em rela??o ao grupo ve?culo (1% de DMSO). Portanto, o piriproxifeno altera a morfologia e o comportamento do peixe-zebra em est?gios iniciais de desenvolvimento e pode afetar as pr?ximas gera??es. No entanto, quando as larvas expostas foram mantidas at? o est?gio adulto (6 meses), n?o observamos diferen?as nos par?metros locomotores. A exposi??o parental ao piriproxifeno induziu uma diminui??o na locomo??o da prole adulta, bem como um comportamento do tipo ansiol?tico. N?s tamb?m avaliamos o efeito da exposi??o ao piriproxifeno em peixe-zebra na fase adulta durante 96 horas sobre a locomo??o, ansiedade, mem?ria e par?metros end?crinos, como express?o g?nica do receptor de glicocorticoide (GR) e fator de libera??o de corticotrofina (CRF). Os resultados demonstraram que n?o houve diferen?a significativa na locomo??o, ansiedade e par?metros end?crinos. Al?m disso, houve um preju?zo da mem?ria de habitua??o do peixe-zebra adulto exposto ? piriproxifeno. Portanto, ? importante controlar o uso de larvicidas devido aos seus efeitos t?xicos em esp?cies n?o-alvo. Nossos achados demonstram a import?ncia de estudos relacionados com a utiliza??o de larvicidas, uma vez que s?o potenciais causadores de altera??es morfol?gicas e comportamentais em esp?cies aqu?ticas, como o peixe-zebra.

APA, Harvard, Vancouver, ISO, and other styles

8

Menezes, Fabiano Peres. "Interfer?ncias na sinaliza??o adenosin?rgica durante a embriog?nese acarretam em altera??es duradouras na morfologia e na sensibilidade a pr?-convulsivantes em peixe-zebra (Danio rerio)." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/8117.

Full text

Abstract:

Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-05-24T14:27:28Z No. of bitstreams: 1 FABIANO_PERES_MENEZES_TES.pdf: 24793474 bytes, checksum: 8b7fdf3efa2bb4839dd339d485cee522 (MD5)
Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-06-11T14:26:49Z (GMT) No. of bitstreams: 1 FABIANO_PERES_MENEZES_TES.pdf: 24793474 bytes, checksum: 8b7fdf3efa2bb4839dd339d485cee522 (MD5)
Made available in DSpace on 2018-06-11T14:31:14Z (GMT). No. of bitstreams: 1 FABIANO_PERES_MENEZES_TES.pdf: 24793474 bytes, checksum: 8b7fdf3efa2bb4839dd339d485cee522 (MD5) Previous issue date: 2018-03-16
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Epilepsy is the most serious neurological condition in the world. It is characterized by recurrent seizures from synchronous neuronal discharges. Disturbances in neuronal signaling in the early stages of development may lead to increased susceptibility to seizures in adulthood, as well as seizures in the early stages of development may lead to alterations in neurotransmission systems. Adenosinergic signaling is known to act as an endogenous anticonvulsant through its neuromodulatory function. Disturbances in adenosinergic signaling in early stages of development lead to changes in the susceptibility to seizures conditionally at the stage of development in which the disturbance occurs, and time of exposure to the disturbing agent. In the four chapters of this thesis, it was discussed about factors that influence the susceptibility to pentylenetetrazole (PTZ)-induced seizure under different aspects using zebrafish. In the first chapter, it was analyzed the influence of temperature on zebrafish sensitivity to PTZ as well as the ability of the MK-801 antagonist to reverse the effects of hyperthermia on susceptibility to PTZ-induced seizures. In addition, it was verifyed possible differences in the susceptibility to seizures according to gender or weight. In the second chapter, it was used transient molecular blockade through the morpholine technique to block the translation of the transcripts corresponding to the adenosinergic A1 and A2A receptors at the beginning of embryogenesis. The animals that underwent transient blockade were evaluated for survival rate and morphology, at 7 days post-fertilization (dpf) and locomotor activity and susceptibility to seizures caused by PTZ at 7 dpf and in adulthood. In the third chapter, it was used the morpholine technique to block the translation of the transcripts corresponding to the enzyme ecto-5'-nucleotidase and concentrative nucleoside transporters type 2 (CNT2) at the beginning of embryogenesis. The animals that underwent transient blockade were evaluated for survival rate and morphology at 7 days post-fertilization (dpf) and locomotor activity and susceptibility to seizures caused by PTZ at 7 dpf and in adulthood. In the fourth chapter, it was performed microinjection of the 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), antagonist of A1 receptor; ZM241385, A2A antagonist; caffeine, non-selective adenosine receptor antagonist; dipyridamole, equilibrative nucleoside transporter blocker (ENT) and Adenosine 5 '- (?, ?-methylene) diphosphate (AMPCP), ecto-5'-nucleotidase enzyme inhibitor, in zebrafish eggs (1 hour post -fertilization). The animals exposed to these drugs were evaluated for survival rate, morphology and locomotor activity at 7 dpf and susceptibility to seizures caused by PTZ at 7 dpf and in adulthood. These results indicated that hyperthermia increases the susceptibility of zebrafish to PTZ-induced seizures and that this effect is prevented by the administration of MK-801. In addition, there was no difference in susceptibility to PTZ dependent on gender or body mass. These results indicated that disturbances in adenosinergic signaling through blockade via morpholine or in the higher doses of the drugs mentioned above, caused a decrease in the survival rate and high rates of morphological changes. None of the approaches caused alterations in the locomotor activity in the initial phase of development, whereas in the adult phase, there were occasional changes. At 7dpf, none of the targets blocked by morpholine caused alterations in the susceptibility to seizures caused by PTZ, whereas among the targets blocked by drugs there was alteration mainly in animals microinjected with DPCPX, Caffeine and Dipyridamole. However, in the adult phase all the targets blocked by morpholine triggered in greater susceptibility to seizures, while those blocked by drugs showed changes in specific doses and seizure stage. These results corroborate a series of studies that report the importance of adenosinergic signaling in the early stages of development as well as the deleterious effects of both exogenous and endogenous perturbations in this signaling pathway.
A epilepsia ? a condi??o neurol?gica grave de maior incid?ncia no mundo. ? caracterizada por crises convulsivas recorrentes, provenientes de descargas neuronais sincr?nicas. Dist?rbios na sinaliza??o neuronal na fase inicial do desenvolvimento podem acarretar em aumento na suscetibilidade a crises convulsivas na fase adulta, assim como crises convulsivas na fase inicial do desenvolvimento podem acarretar em altera??es nos sistemas de neurotransmiss?o. A sinaliza??o adenosin?rgica reconhecidamente ? capaz de agir como um anticonvulsivante end?geno, atrav?s de sua fun??o neuromoduladora. Perturba??es na sinaliza??o adenosin?rgica em fases inicias do desenvolvimento acarretam em altera??es na suscetibilidade a crises convulsivas de forma condicional ao est?gio de desenvolvimento em que a perturba??o ocorre e tempo de exposi??o ao agente perturbador. Nos quatro cap?tulos integrantes dessa tese foram abordados, sob diferentes aspectos, fatores que influenciam a susceptibilidade a crise convulsiva provocada pela exposi??o ao pentilenotetrazol (PTZ) utilizando peixe-zebra. No primeiro cap?tulo, foi analisada a influ?ncia da temperatura na sensibilidade do peixe-zebra ao PTZ, bem como a capacidade do antagonista MK-801 de reverter os efeitos provocados pela hipertermia na suscetibilidade a crises convulsivas induzidas por PTZ. Al?m de serem verificadas as poss?veis diferen?as na suscetibilidade a crises convulsivas em fun??o do g?nero ou peso. No segundo cap?tulo, foi descrito o uso do bloqueio molecular transit?rio atrav?s da t?cnica de morfolinos para bloquear a tradu??o dos transcritos correspondentes aos receptores adenosin?rgicos A1 e A2A no inicio da embriog?nese. Os animais que sofreram o bloqueio transit?rio foram avaliados quanto a taxa de sobreviv?ncia e morfologia at? os 7 dias p?s-fertiliza??o (dpf) e atividade locomotora e suscetibilidade a crises convulsivas provocadas por PTZ aos 7 dpf e na fase adulta. No terceiro cap?tulo, foi descrito o uso da t?cnica de morfolinos para bloquear a tradu??o dos transcritos correspondentes a enzima ecto-5?-nucleotidase (e5?nt) e transportadores concentrativos de nucleos?deo tipo 2 (CNT2) no inicio da embriog?nese. Os animais que sofreram o bloqueio transit?rio foram avaliados quanto a taxa de sobreviv?ncia e morfologia aos 7 dpf e atividade locomotora e suscetibilidade a crises convulsivas provocadas por PTZ aos 7dpf e na fase adulta. No quarto cap?tulo, foi abordado o efeito da microinje??o de 8-Ciclopentil-1,3-dipropilxantina (DPCPX), antagonista do receptor A1; ZM241385 antagonista do receptor A2A; cafe?na, antagonista n?o-seletivo dos receptores de adenosina; dipiridamol, bloqueador do transportador equilibrativo de nucleos?deo (ENT) e Adenosina 5?-(?,?-metileno)difosfato (AMPCP), inibidor da enzima ecto-5?-nucleotidase, nos ovos do peixe-zebra (1 hora p?s-fertiliza??o). Os animais expostos a estes f?rmacos foram avaliados quanto a taxa de sobreviv?ncia, morfologia, atividade locomotora aos 7 dpf e suscetibilidade a crises convulsivas provocadas por PTZ aos 7dpf e na fase adulta. Nossos resultados apontam que a hipertermia aumenta a suscetibilidade do peixe-zebra a crises convulsivas provocadas por PTZ e que esse efeito ? prevenido pela administra??o de MK-801. Al?m disso, n?o houve diferen?a na suscetibilidade do PTZ dependente de g?nero ou massa corporal. Nossos resultados indicam que perturba??es na sinaliza??o adenosin?rgica atrav?s de bloqueio via morfolinos ou nas doses mais altas dos f?rmacos acima citados, provocaram diminui??o na taxa de sobreviv?ncia e altas taxas de altera??es morfol?gicas. Nenhuma das abordagens provocou altera??es na atividade locomotora na fase inicial do desenvolvimento, enquanto que na fase adulta foram verificadas altera??es pontuais. Aos 7dpf nenhum dos alvos bloqueados por morfolinos provocou altera??o na suscetibilidade a crises convulsivas provocadas por PTZ, enquanto que entre os alvos bloqueados por f?rmacos houve altera??o principalmente em animais microinjetados com DPCPX, Cafe?na e Dipiridamol. J? na fase adulta todos os alvos bloqueados por morfolinos desencadearam em maior suscetibilidade a crises convulsivas enquanto os bloqueados por f?rmacos exibiram altera??es em doses e est?gio de convuls?o espec?ficos. Esses resultados corroboram com uma s?rie de estudos que reportam a import?ncia da sinaliza??o adenosin?rgica na fase inicial do desenvolvimento, bem como os efeitos delet?rios provenientes de perturba??es tanto ex?genas quanto end?genas nessa via de sinaliza??o.

APA, Harvard, Vancouver, ISO, and other styles

9

Siebel, Anna Maria. "O papel do sistema purinérgico e da via de sinalização TOR em crises convulsivas e estresse oxidativo." Pontifícia Universidade Católica do Rio Grande do Sul, 2013. http://hdl.handle.net/10923/5484.

Full text

Abstract:

Made available in DSpace on 2013-10-11T13:35:16Z (GMT). No. of bitstreams: 1 000451454-Texto+Completo-0.pdf: 6697842 bytes, checksum: 890c954db41088b36538c3133a7c2606 (MD5) Previous issue date: 2013
Epilepsy, characterized by the occurrence of spontaneous and recurrent seizures, is one of the main chronic neurological diseases, affecting around 1% of the world's population. Adenosine is an endogenous modulator of neuronal excitability and has anticonvulsant properties. Thus, the modulation of adenosinergic signalling pathway may presents important effects on epilepsy. In this study we characterize different aspects of the adenosinergic signaling in a model of seizures induced by pentylenetetrazole (PTZ) in zebrafish. In this study we also analyzed the effect of different modulators of adenosinergic signaling on controlling the development of seizures. Our results showed that the activation of type A1 adenosine receptors has an important role in controlling seizures in zebrafish. Furthermore, we observed that ecto-5´-nucleotidase and ADA enzymes, in addition to nucleoside transporters, are directly involved in controlling extracellular adenosine levels and, consequently, in controlling the development of seizures in this teleost. In addition, we clarified the occurrence of controversial data related to the mTOR signaling pathway in oxidative stress. Previous studies have suggested the activation of this pathway in oxidative stress based on the misinterpretation of the phosphorylation of RSK and MSK proteins through the antibody anti-phospho-Thr389-S6K, in addition to protein S6 phosphorylation, regulated by the MAPK signaling pathway in this case. Therefore, these findings might contribute for a better understanding about the signaling pathways involved in the mechanisms of seizure control and represents na alternative for the development of antiepileptic drugs, increasing the therapeutic options in epilepsia. Our results may also contribute to future studies on the characterization and modulation of TOR signaling pathway in zebrafish.
A epilepsia, caracterizada pela ocorrência de crises convulsivas espontâneas e recorrentes, é umas das principais doenças neurológicas crônicas, afetando em torno de 1% da população mundial. A adenosina é um modulador endógeno da excitabilidade neuronal e apresenta propriedades anticonvulsivantes. Sendo assim, a modulação da via de sinalização adenosinérgica pode apresentar um efeito importante na epilepsia. Neste estudo, nós caracterizamos diferentes aspectos da sinalização adenosinérgica em modelo de crise convulsiva induzida por pentilenotetrazol (PTZ) em peixe-zebra. Nossos resultados demonstram um aumento nas atividades da adenosina desaminase (ADA), responsável pela desaminação de adenosina em inosina, logo após uma crise convulsiva. Além disso, foi observado que os fármacos antiepilépticos gabapentina, fenitoína e ácido valpróico preveniram o efeito estimulatório promovido pelo PTZ sobre as atividades da adenosina desaminase. Neste estudo, também analisamos o efeito de diferentes moduladores da sinalização adenosinérgica no controle do desenvolvimento de convulsões induzidas por PTZ. Nossos resultados demonstraram que a ativação de receptores de adenosina do tipo A1 tem importante participação no controle de crises convulsivas em peixe-zebra. Além disso, observamos que as enzimas ecto-5´-nucleotidase e ADA, além dos transportadores de nucleosídeos estão diretamente envolvidos no controle dos níveis extracelulares de adenosina e, consequentemente, no controle do desenvolvimento de crises convulsivas neste teleósteo. Além disso, esclarecemos a ocorrência de dados controversos relacionados à via de sinalização mTOR em estresse oxidativo. Estudos sugeriram a ativação desta via em estresse oxidativo baseados na interpretação equivocada da fosforilação das proteínas RSK e MSK pelo anticorpo anti-fosfo-Thr389-S6K, além da fosforilação da proteína S6, regulada neste caso pela via de sinalização MAPK. Este estudo pode contribuir para um maior entendimento das vias de sinalização envolvidas nos mecanismos de controle de crises convulsivas e representar uma alternativa para o desenvolvimento de fármacos antiepilépticos, aumentando as opções terapêuticas em epilepsia. Nossos resultados também podem contribuir para futuros estudos referentes à caracterização e modulação da via de sinalização TOR em peixe-zebra.

APA, Harvard, Vancouver, ISO, and other styles

10

Young, Helena. "Experiences of mental health professionals : patient suicide and working in a crisis team." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/55965/.

Full text

Abstract:

This research thesis explores mental health professionals’ reactions to patient suicide and the emotional experiences of working in a Crisis Team. Chapter one is a literature review examining twelve empirical studies of the impact of patient suicide on mental health professionals and the resources they draw on to cope with the effects. The review revealed a range of personal and professional responses amongst professionals and highlighted the concept of blame in the coping process. Chapter two is a qualitative empirical study of seven clinicians’ emotional experiences of working in a UK Crisis Team. Interpretative Phenomenological Analysis revealed three main themes of importance; response to difficult emotions, impact on self and intergroup processes. The clinical implications and areas for future research are discussed alongside methodological considerations and limitations. Chapter three is a reflective account of the emotional experience of conducting the research and considers the impact of the chosen methodology, parallels of experience between the researcher and the participants and the impact of the research process on future clinical practice.

APA, Harvard, Vancouver, ISO, and other styles

11

Nilsson, Louise. "The biodiversity loss crisis in Southeast Asia." Thesis, Malmö universitet, Fakulteten för kultur och samhälle (KS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-24000.

Full text

Abstract:

Denna kandidatuppsats gör en ansats till att belysa biodiversitetsproblematiken i Sydostasien, som är ett område med mycket hög artrikedom som samtidigt hotas av en intensifierad förlust av arter. Fyra ’biodiversitet hotspots’ omger Sydostasien, vilka indikerar platser med hög artrikedom vilka sammanfaller med hög förlust av habitat. Det största orsaken till förlust av biologisk mångfald i Sydostasien är omvandlingen utav artrika naturtyper till monokulturodlingar, och expansionen av jordbruk och urbana områden. För att undersöka den pågående biodiversitetsforskningen genomfördes en systematisk litteraturanalys av publicerade artiklar från 2010-2019. Vad litteraturanalysen kom fram till var att flera problem, socioekonomiska samt miljöproblem intensifierar varandra, liksom fattigdom och förlust av biologisk mångfald. Internationellt samarbete krävs för att stoppa exploateringen av de värdefulla arter och naturtyper som går förlorade till fördel för den globala handeln med produkter som kommer från området. Medel för att stoppa denna biodiversitetskatastrof måste riktas till forskning och organisationer som arbetar i området. Vi bör genast agera på ett globalt plan för att förhindra förlusten av biodiversitet samt dess tillhörande ekosystemtjänster, detta skulle kunna tacklas genom att vi rör oss ifrån den antropocentriska och emot den ekocentriska natursynen.
This bachelor thesis focuses on the biodiversity loss problematics in Southeast Asia, since it is one of the most species rich places on Earth, coupled with the highest rate of loss of species. Four biodiversity hotspots encompasses Southeast Asia which implies areas of high endemism coupled with high rates habitat loss. This thesis aim to understand what current research in the field focuses on and what ways of protecting biodiversity in the area that exists. The main driver of biodiversity loss in Southeast Asia as well as in the rest of the world, are land-use alterations; forests and natural habitat being converted to monoculture plantations, as well as agricultural- and urban expansions. Through a systematic literature review of scientific material from 2010-2019, the biodiversity research in Southeast Asia is reviewed. What the literature review concluded was that an array of environmental- as well as socioeconomic problems intensifies each other in the area, such as poverty and biodiversity loss. International cooperation to halt biodiversity loss and the global demand for products produced in the area which greatly damages ecosystems needs to be addressed urgently. Actions to halt the mass-extinction of species and their connected ecosystem services needs to be taken by providing means to organizations and to scientists that work in the area and could possibly be addressed by moving from anthropocentrism towards a biocentric nature view.

APA, Harvard, Vancouver, ISO, and other styles

12

Siebel, Anna Maria. "Efeito de crises convulsivas e fármacos antiepilépticos em parâmetros neuroquímicos e moleculares em peixe zebra (Danio rerio)." Pontifícia Universidade Católica do Rio Grande do Sul, 2011. http://hdl.handle.net/10923/1323.

Full text

Abstract:

Made available in DSpace on 2013-08-07T18:41:37Z (GMT). No. of bitstreams: 1 000431137-Texto+Completo-0.pdf: 15580738 bytes, checksum: 8de463b0a32f5623e6e47a0d1d0edad2 (MD5) Previous issue date: 2011
Epilepsy is a neurological disorder characterized by the occurrence of spontaneous and recurrent seizures. This disease and its treatment influence diverse neurological pathways. The purinergic system is an essential route for cell-to-cell communication and employs extracellular nucleotides and nucleosides as signaling molecules. The neurotransmitter ATP mediates synaptic currents through activation of G-proteincoupled P2Y receptors and P2X ionotropic receptors. The ATP degradation and consequent production of adenosine is promoted by a family of enzymes named ectonucleotidases, which includes NTPDases (nucleoside triphosphate diphosphohydrolases) and ecto-5´-nucleotidase. Adenosine is a neuromodulator that acts through the activation of P1 metabotropic receptors (A1, A2A, A2B, and A3). Adenosine can acts as an endogenous anticonvulsant, mainly by A1 receptors. The NTPDases hydrolyze both tri- and diphosphonucleosides whereas ecto-5’- nucleotidase hydrolyzes nucleoside monophosphates producing the nucleoside adenosine, that is hydrolyzed by adenosine deaminase (ADA). Therefore, NTPDases, ecto-5’-nucleotidase, and ADA control nucleotide and nucleoside levels, modulating the purinergic signaling. In the cholinergic system, acetylcholine (ACh) acts through muscarinic (metabotropic) and nicotinic (ionotropic) receptors. ACh is inactivated by its hydrolysis, that is catalyzed by acetylcholinesterase (AChE). Zebrafish is a small freshwater teleost which is becoming widely used as an experimental organism. Studies have demonstrated that zebrafish could be an important model to study seizures and to screen antiepileptic drugs. Considering that the purinergic and cholinergic systems exert an important role in the nervous system and that these neurotransmitter pathways have been already described in zebrafish, the aim of this study was to evaluate in this teleost the effect of pentylenetetrazole (PTZ)-induced seizures and antiepileptic drugs on the ectonucleotidases, ADA, and AChE activities. We have tested the in vitro effects of carbamazepine, phenytoin, and gabapentine at different concentrations on ectonucleotidase and AChE activities. Our results have shown that carbamazepine reduced ATP and ACh hydrolysis whereas phenytoin enhanced AMP hydrolysis. Gabapentin did not promote any changes on enzymatic activities. In addition, we tested the effect of PTZ-induced seizures on ectonucleotidases and ADA activities in adult zebrafish brain. Our results have demonstrated that PTZ treatments did not alter ectonucleotidase and ADA activities in membranes and soluble fraction, respectively. However, ecto-ADA activity was significantly decreased in brain membranes of animals exposed to PTZ treatments. These results have shown that antiepileptic drugs can influence the enzyme activities involved in the degradation of ACh and extracellular nucleotides. Furthermore, the decreased adenosine deamination observed in our study suggests the ADA participation on the modulation of extracellular adenosine levels during PTZinduced seizures in zebrafish.
A epilepsia é uma desordem neuronal caracterizada pela ocorrência de convulsões espontâneas e recorrentes. Essa patologia e seu tratamento interferem em diversos mecanismos neurológicos. O sistema purinérgico é uma importante rota de sinalização celular que emprega nucleotídeos e nucleosídeos extracelulares como moléculas sinalizadoras. O neurotransmissor ATP atua através de receptores do tipo P2Y, acoplados à proteína G e receptores P2X, que são ionotrópicos. A degradação do ATP extracelular e a conseqüente produção de adenosina é realizada por uma família de enzimas de superfície celular conhecidas como ectonucleotidases, que inclui as NTPDases (nucleosídeo trifosfato difosfoidrolases) e a ecto-5´-nucleotidase. A adenosina é um neuromodulador que atua através da ativação de receptores metabotrópicos do tipo P1 (A1, A2A, A2B, A3). Esse nucleosídeo pode agir como um anticonvulsivante endógeno, principalmente via receptores A1. As NTPDases hidrolisam nucleotídeos tri- e difosfatados originando a adenosina, que é hidrolisada pela adenosina deaminase (ADA). Assim, as NTPDases, ecto-5’-nucleotidase e ADA controlam os níveis de nucleotídeos e nucleosídeos, modulando o sistema purinérgico. No sistema colinérgico, a acetilcolina (ACh) atua através de receptores muscarínicos (metabotrópicos) e nicotínicos (ionotrópicos). Sua ação é encerrada através de sua hidrólise catalisada pela acetilcolinesterase (AChE). O peixe zebra é um pequeno teleósteo de água doce que vem sendo amplamente utilizado como modelo experimental em pesquisa. Estudos mostram que o peixe zebra pode ser uma ferramenta importante para o entendimento da epilepsia, bem como para o screening de fármacos antiepilépticos. Considerando que as sinalizações purinérgica e colinérgica têm importante participação no sistema nervoso e que essas vias de neurotransmissão estão identificadas e caracterizadas em peixe zebra, o objetivo desse estudo foi avaliar nesse teleósteo o efeito de convulsões induzidas por pentilenotetrazol (PTZ), bem como de fármacos antiepilépticos na atividade das ectonucleotidases, ADA e AChE, enzimas essenciais na modulação destas vias de sinalização. Foram avaliados os efeitos in vitro da carbamazepina, fenitoína e gabapentina na atividade das ectonucleotidases e AChE. A carbamazepina diminuiu a hidrólise de ATP e também de ACh. A fenitoína aumentou a hidrólise de AMP e a gabapentina não provocou alterações enzimáticas. Foi analisado também o efeito de crises convulsivas induzidas por PTZ na atividade das ectonucleotidases e da ADA. Os resultados não mostraram alterações nas ectonucleotidases e ADA nas frações extracelular e intracelular, respectivamente. No entanto, a atividade extracelular da ADA foi inibida em animais expostos ao PTZ. As análises mostraram que os fármacos antiepilépticos podem influenciar a atividade das enzimas envolvidas na degradação extracelular de nucleotídeos, bem como na hidrólise de ACh. Além disso, a diminuição na degradação de adenosina observada em nosso modelo de estudo pode sugerir a participação da ADA na modulação nos níveis de adenosina durante as crises convulsivas em peixe zebra.

APA, Harvard, Vancouver, ISO, and other styles

13

Piza, Patrícia Bonilha de Toledo. "ANÁLISE GENÉTICA DOS VESTÍGIOS DE CRIMES SEXUAIS." Pontifícia Universidade Católica de Goiás, 2012. http://localhost:8080/tede/handle/tede/2342.

Full text

Abstract:

Made available in DSpace on 2016-08-10T10:38:31Z (GMT). No. of bitstreams: 1 PATRICIA BONILHA DE TOLEDO PIZA.pdf: 970259 bytes, checksum: e296c4994d48ecfafd048f3cc57617e4 (MD5) Previous issue date: 2012-08-31
In Brazil sexual violence is a crime. Rape and vulnerable rape are heinous crimes. It is estimated that only 10% of rapes are recorded and the SENASP point 42.946 police incidents in 2010. Most victims are women aged below 14 years. The absence of expert evidence difficult the sentencing of the offender. In victim, exams corpus delicti of carnal knowledge and research of semen when positive do not identify the perpetrator and negativity is not a factor of no sexual assault. Genetic analysis by PCR-STR and Y identifies the presence of male DNA and the genetic profile of the perpetrator. This paper aims to analyze samples for traces of sex crimes to obtain molecular profiles of Y-STR. We selected 19 cases of sex crimes with no suspect, totaling 20 female victims aged 11 months to 81 years, which resulted in 48 samples questioned, of which 44 were subjected to differential extraction and 4 to organic extraction, totaling 92 products extraction (44 SF, 44 NSF and 4 Organic). The DNA quantitation by real-time PCR detected the presence of male DNA in 62% of the samples. Of these, 21 samples were selected and standardized to a concentration of Y-DNA 0.1 ng to 1.25 ng / PCR reaction for Y-STR. Amplification was performed for 17 joint multiplex Y-STR markers and electrophoresis capillary was preceded in genetic analyzer and the results were analyzed by programs. Of the 21 samples amplified, 12 had results for Y-STR and their haplotype been classified as full (Y-STR 17), minimum (11 Y-STR) and incomplete (absence of one or more of the Y-STR minimum haplotype) resulting 10 minimal haplotypes and complete and 02 incomplete. After comparing the minimum haplotypes and complete intra case and between their criminal cases, it was evident that the sexual assaults were committed in each case, by a single assailant, not featuring serial crimes. It is easy to recognize the importance that the Y-STR haplotype analysis assumes the sexual crimes as expert evidence, especially when it becomes the only genetic information of the offender being questioned samples obtained. The results presented in this study demonstrate the importance of being analyzed the largest number of polymorphic markers Y-STR haplotype to compose an informative, giving preference to multiplex sets that amplify multiple loci simultaneously, including polymorphic markers with products up to 200 base pairs.
No Brasil a violência sexual é crime. O estupro e o estupro de vulnerável são crimes hediondos. Estima-se que apenas 10% dos estupros são registrados e dados da SENASP apontam 42.946 ocorrências policiais em 2010. A maioria das vítimas é do sexo feminino com idade abaixo de 14 anos. A ausência de prova pericial dificulta a condenação do agressor. Na vítima, os exames de corpo de delito de conjunção carnal e pesquisa de sêmen quando positivos não identificam o agressor e a negatividade não é fator de inexistência de agressão sexual. A análise genética, através da PCR e Y-STR permite identificar a presença de DNA masculino e o perfil genético do agressor. Este trabalho objetiva analisar amostras de vestígios de crimes sexuais para a obtenção de perfis moleculares de Y-STR. Foram selecionados 19 casos de crimes sexuais com ausência de suspeito, totalizando 20 vítimas do sexo feminino com idade entre 11 meses a 81 anos, que resultaram em 48 amostras questionadas, das quais 44 foram submetidas à extração diferencial e 4 à extração orgânica, totalizando 92 produtos de extração (44 FE, 44 FNE e 4 Orgânica). A quantificação de DNA pela PCR em tempo real detectou a presença de DNA masculino em 62% das amostras extraídas. Destas, 21 amostras foram selecionadas e normalizadas a uma concentração de Y-DNA entre 0,1 ng a 1,25 ng/reação de PCR para Y-STR. A amplificação foi realizada com conjunto multiplex para 17 marcadores Y-STR e a eletroforese capilar foi procedida em analisador genético; os resultados foram analisados por programas específicos. Das 21 amostras amplificadas, 12 apresentaram resultados para Y-STR e seus haplótipos foram classificados como completo (17 Y-STR), mínimo (11 Y-STR) e incompleto (ausência de 1 ou mais Y-STR do haplótipo mínimo), resultando em 10 haplótipos mínimos e completos e 02 incompletos. Após confrontar os haplótipos mínimos e completos intra caso e entre os respectivos casos criminais, ficou evidenciado que as agressões sexuais foram cometidas, em cada caso, por um único agressor, não caracterizando crimes em série. É de facil reconhecimento a importância que o haplótipo de Y-STR assume nas análises de crimes sexuais como prova pericial, principalmente quando este se torna a única informação genética do agressor a ser obtida de amostras questionadas. Os resultados apresentados neste estudo demonstraram a importância de serem analisados o maior número de marcadores polimórficos Y-STR para compor um haplótipo informativo, dando-se preferência a conjuntos multiplex que amplificam simultaneamente vários loci, incluindo marcadores polimórficos com produtos de até 200 pares de bases.

APA, Harvard, Vancouver, ISO, and other styles

14

Gaspary, Karina Vidarte. "Mem?ria de reconhecimento e localiza??o de objetos em peixe-zebra (Danio rerio) : influ?ncia da sinaliza??o glutamat?rgica e respostas end?crinas." Pontif?cia Universidade Cat?lica do Rio Grande do Sul, 2018. http://tede2.pucrs.br/tede2/handle/tede/8023.

Full text

Abstract:

Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2018-04-24T12:44:41Z No. of bitstreams: 1 KARINA_VIDARTE_GASPARY_DIS.pdf: 1111674 bytes, checksum: e2b2dc4b1b1eea8b10007b7c07f592ec (MD5)
Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-05-11T17:57:10Z (GMT) No. of bitstreams: 1 KARINA_VIDARTE_GASPARY_DIS.pdf: 1111674 bytes, checksum: e2b2dc4b1b1eea8b10007b7c07f592ec (MD5)
Made available in DSpace on 2018-05-11T18:03:07Z (GMT). No. of bitstreams: 1 KARINA_VIDARTE_GASPARY_DIS.pdf: 1111674 bytes, checksum: e2b2dc4b1b1eea8b10007b7c07f592ec (MD5) Previous issue date: 2018-02-08
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
Memory and learning allow animals to adapt and modify their behavior towards new experiences. Some factors may result in memory deficits such as: neurodegenerative diseases, changes due to intoxication and the use of drugs. Zebrafish can be used to model complex human behavioral traits such as learning and memory. This study aims to establish a protocol for evaluating the object recognition memory or object location tasks in zebrafish. We evaluated novel object recognition memory and analyzed the exploration time of novel and familiar objects in the training and test sessions. There was a preference of the animal to explore the new object in comparison to the familiar object (61% of exploration time). We also evaluated the object location task and measured the exploration time of each object in the familiar and novel object locations. There was a preference of the animal to explore the object in the novel location in comparison to the object in the familiar location (63% of exploration time). We also evaluated the effect of the non-competitive NMDA receptor antagonist MK-801 on the object recognition and object location memory in zebrafish. In this regimen treatment, control (water only) and treated animals (5 ?M MK-801) presented a significant preference in exploring the familiar object in comparison to the new object (66 and 68% of exploration time, respectively); however, 10 ?M MK-801-treated animals did not show differences in the exploration time of the objects. In the object location task, the animals treated with the 5 or 10 ?M MK-801 did not show a significant preference for the familiar or novel location whereas the control group had a higher preference in exploring the object in the familiar location (64% of exploration time). Therefore, it is possible to suggest that 5 ?M MK-801 impaired the memory formation in an object location task, which is in agreement with previous studies demonstrating the cognitive deficit induced by MK-801 treatment in aversive and spatial memory. Considering the different responses of the control group between original task and in the regimen treatment, we evaluated the impact of habituation on cortisol levels of animals in three different protocols: 1) habituated at the experiment apparatus for 3 days (Condition 1 ? C1), 2) habituated at the experiment apparatus for 3 days plus treatment tank exposure at fourth day (Condition 2 - C2), 3) habituated at the treatment tank exposure and experiment apparatus for 3 days and exposed to treatment tank again at fourth day (Condition 3 ? C3). The results showed higher levels of cortisol in animals submitted to C2 and C3 conditions compared to animals submitted to C1. These results demonstrated that the animals submitted to treatment tank exposure have a different performance in object recognition and object location memory due to stress responses. Therefore, these tasks are prone to evaluate memory in physiological and pathological conditions, but its use is limited to perform pharmacological studies due to sensitivity to stress caused by manipulation.
A mem?ria permite que os animais possam adaptar e modificar seu comportamento diante de novas experi?ncias. Uma s?rie de fatores pode resultar num d?ficit de mem?ria como: doen?as neurodegenerativas, altera??es decorrentes de intoxica??es e uso de f?rmacos. O peixe-zebra vem sendo usado para modelar caracter?sticas comportamentais humanas complexas, como o aprendizado e mem?ria. Este estudo tem como objetivo estabelecer um protocolo para avaliar tarefas de mem?ria de reconhecimento de objetos ou de localiza??o de objetos no peixe-zebra. N?s avaliamos a mem?ria de reconhecimento de objeto novo e analisamos o tempo de explora??o de objetos novos e familiares nas sess?es de treino e teste. Houve uma prefer?ncia do animal em explorar o novo objeto em compara??o com o objeto familiar (61% do tempo de explora??o). Tamb?m avaliamos a tarefa de localiza??o de objeto e medimos o tempo de explora??o de cada objeto nos locais familiares e novos. Houve uma prefer?ncia do animal para explorar o objeto na localiza??o nova em compara??o com o objeto na localiza??o familiar (63% do tempo de explora??o). Tamb?m avaliamos o efeito do antagonista n?o competitivo do receptor NMDA MK-801 na mem?ria de reconhecimento de objeto novo e na localiza??o de objeto em peixe-zebra. Neste tratamento, o controle (somente ?gua) e os animais tratados (MK-801 5 ?M) apresentaram uma prefer?ncia significativa na explora??o do objeto familiar em compara??o com o novo objeto (66 e 68% do tempo de explora??o, respectivamente); no entanto, animais tratados com MK-801 10 ?M n?o mostraram diferen?as no tempo de explora??o dos objetos. Na tarefa de localiza??o de objeto, os animais tratados com MK-801 5 ou 10 ?M n?o mostraram prefer?ncia significativa pelo objeto na localiza??o familiar ou nova, enquanto que o grupo controle teve uma prefer?ncia maior em explorar o objeto na localiza??o familiar (64% de tempo de explora??o). Portanto, sugere-se que o MK-801 5 ?M prejudicou a forma??o da mem?ria em uma tarefa de localiza??o de objeto, o que est? de acordo com estudos pr?vios, demonstrando o d?ficit cognitivo induzido pelo MK-801 em mem?rias aversivas ou espaciais. Considerando as diferentes respostas do grupo controle entre a tarefa original e no tratamento, avaliamos o impacto da habitua??o nos n?veis de cortisol dos animais em tr?s protocolos diferentes: 1) habituado ao aparato experimental por 3 dias (Condi??o 1 - C1) 2) habituado ao aparato experimental por 3 dias mais a exposi??o ao aqu?rio de tratamento no quarto dia (Condi??o 2 - C2), 3) habituado na exposi??o ao aqu?rio de tratamento e no aparato experimental por 3 dias e exposto ao aqu?rio de tratamento novamente no quarto dia (Condi??o 3 - C3). Os resultados mostraram n?veis mais elevados de cortisol em animais submetidos a condi??es C2 e C3 em compara??o com animais submetidos a C1. Esses resultados demonstraram que os animais submetidos ? exposi??o ao aqu?rio de tratamento apresentam desempenho diferente nas tarefas de mem?ria de reconhecimento de objetos e de localiza??o do objeto devido ao estresse. Portanto, essas tarefas s?o adequadas para avaliar a mem?ria em condi??es fisiol?gicas e patol?gicas, mas seu uso ? limitado em estudos farmacol?gicos devido ? sensibilidade ao estresse causado pela manipula??o.

APA, Harvard, Vancouver, ISO, and other styles

15

Vasseur, Raphaël. "Extinctions et recouvrements de coraux au cours de la crise Pliensbachien - Toarcien." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0204/document.

Full text

Abstract:

Le passage entre les étages géologiques du Pliensbachien et du Toarcien au Jurassique inférieur est suivi au Toarcien inférieur par un évènement anoxique d’importance planétaire (TOAE pour Toarcian Oceanic Anoxic Event). Dans les archives de l’histoire de la terre, ce moment correspond en bien des endroits à un temps de fossilisation massive de matière organique donnant ici où là des roches mères d’intérêt pétrolier. Si, en termes de fluctuation du niveau eustatique, ces évènements sont souvent situés dans une zone d’inondation maximale de 2ème ordre, ils sont aussi interprétés comme une perturbation globale du cycle du carbone avec acidification des océans, liée à la mise en place des provinces ignées du Karroo-Ferrar en Afrique du Sud et en Amérique du Sud, contrées jointives à ce moment-là. Il s’agit d’une période de réchauffement global faisant suite à une période particulièrement froide au Pliensbachien. Cette perturbation écologique globale a certainement affecté la biosphère dans une mesure qui reste aujourd’hui très mal connue. Nous connaissons des études par exemple sur des ammonites ou des bivalves dont la définition stratigraphique permet rarement de distinguer l’impact du passage de la limite entre les deux étages du passage au Toarcien inférieur de la TOAE et la seule étude disponible sur les coraux est une étude purement bibliographique (Lathuilière et Marchal 2009) qui laisse supposer une extinction significative sur la même période. Les coraux sont très généralement des marqueurs particulièrement précieux des perturbations écologiques majeures comme on peut le voir pour les cinq grandes extinctions et même pour la sixième extinction en cours. Cette extinction au Pliensbachien-Toarcien pour l’instant considérée de second ordre mérite donc d’être analysée de ce point de vue. Dans le cadre de cette thèse, des collectes de coraux ont été effectuées sur le terrain au Maroc et en Italie dans un contexte sédimentologique défini de part et d’autre de la limite Pliensbachien - Toarcien. Les prélèvements ont été réalisés de façon à pouvoir évaluer la diversité ainsi que, dans la mesure du possible, la variabilité intraspécifique. Le traitement statistique des données a été réalisé dans le souci d’assurer une bonne connaissance de la variabilité pour fournir une taxinomie fiable dans l’optique de comparer des populations comparables en termes d’analyse de la diversité, des extinctions et des apparitions de taxons. Au total, 107 espèces ont été décrites (dont au moins 19 nouvelles espèces) réparties parmi 60 genres (dont 5 nouveaux) dans au moins 22 familles (dont 1 nouvelle). Cette étude nous révèle pour les eaux froides et chargées en matière organique du Pliensbachien des assemblages de coraux présentant une grande part d’affinité avec les faunes du Trias (en termes de genres et familles). Ils partagent une partie de leurs niches écologiques sur les plateformes internes de l’ouest téthysien avec des bivalves constructeurs de récifs connaissant alors un succès évolutif fulgurant : les lithiotidés. Les données récoltées témoignent de conditions ayant contraint les coraux à s’adapter et à se diversifier pour se maintenir lors de cette période peu propice, au profit des formes solitaires et phacéloïdes et au détriment des formes de plus hauts niveaux d’intégration. Au Toarcien inférieur, le réchauffement global des eaux couplé à la disparition quasi-totale des concurrents des coraux a permis une explosion de diversité déterminante pour l’avenir de ce groupe avec la mise en place de faunes d’assemblages très similaires à celles du Jurassique moyen et supérieur (en terme de genres, familles et morphologies coloniales). Il s’agit d’un évènement d’extinction biphasé dont la première phase se produit au passage entre Pliensbachien et Toarcien, la seconde phase correspondant au passage du TOAE. L’évènement pris dans son ensemble amène à l’extinction de près de 97% des espèces de coraux présentes au Pliensbachien
The transition from the Pliensbachian to the Toarcian geological stages in Lower Jurassic is followed by a global oceanic anoxic event during the lower Toarcian (TOAE for Toarcian Oceanic Anoxic Event). This moment corresponds to a massive fossilization time for organic matter in the worldwide geological record that produced here and there source rocks of petroleum interest. Concerning the eustatic fluctuations, these events are associated to a second-order maximal flooding zone. They are also interpreted as the remains of a global carbon-cycle perturbation case associated with oceanic acidification and correlated with the setup of Karoo-Ferrar igneous provinces in the southern Pangea territories corresponding to present-day Southern Africa and Southern America. It corresponds to a period of global warming that directly follow a global cooling at the Pliensbachian. This worldwide ecological perturbation probably disturbed the biosphere in a degree that is still poorly quantified. For example, studies about ammonites and bivalvs are known but the stratigraphic definition generally do not allow to distinguish the Pliensbachian-Toarcian boundary itself to the TOAE effect on these fauna. One single available study about corals is purely bibliographic (Lathuiliere and Marchal 2009) and suggests a significant extinction event for this group at the same period. Corals are generally precious indicators for major ecological disruptions as it is testified in the case of the big-five major crisis and the current sixth one. The Pliensbachian-Toarcian extinction has been considered up-to-now as a second-order crisis event and require to be studied as such. In the context of this thesis, fossilized corals have been collected in the field in Morocco and Italy in a well-defined sedimentological context before and after the Pliensbachian-Toarcian boundary. Sampling has been in view to quantify the diversity and as far as possible, the intraspecific variability. The statistical treatment of the data has been realized in view to provide a satisfying quantification of the variability in order to supply a strong taxonomy and be able to compare comparable populations in analyses of diversity, extinctions and apparitions of taxons. In total, 107 species have been describes (including at least 19 new species) as part of 60 genera (including 5 new ones) among 22 families (including a new one). According to this study, the cold and highly concentrated in organic matter oceanic waters of the Pliensbachian contained corals faunas with an important affinity with Triassic faunas (in terms of genera and families). They shared the ecological niches of the western tethysian inner platforms with the lithiotids, a group of aberrants reefal bivalvs that demonstrated a stupendous evolutive success during the same period. Collected data attest of conditions that constrained corals to adapt and diversify in view to maintain during these unfavourable times, for the benefit of the solitary and phaceloid form but at the expense of the highly integrated forms. During the Lower Toarcian, global warming of oceanic waters associated with the almost total disparition of the competitors premised an explosion of diversity that is determinant for the future of the corals, with the apparition of faunal assemblages very similar to the typical Middle and Upper Jurassic ones (in terms of genera, families and colonial morphologies). It is a two-folded extinction event with a first phase during the Pliensbachian –Toarcian transition and a second phase at the onset of the TOAE. In the end, this pulsed event led to the extinction of approximately 97% of the Pliensbachian coral species

APA, Harvard, Vancouver, ISO, and other styles

16

Fleck, Juliana. "MONTELUCASTE DIMINUI AS CRISES CONVULSIVAS EM ANIMAIS ABRASADOS E POTENCIALIZA O EFEITO ANTICONVULSIVANTE DO FENOBARBITAL." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/3855.

Full text

Abstract:

Epilepsy is a chronic neurological disease characterized by recurrent, unprovoked seizures. Evidence suggests that inflammation plays a role in the pathophysiology of seizures. Although cysteinyl leukotrienes (CysLTs) have been implicated in seizures, no study has investigated whether blocking of CysLT1 receptors potentiates the anticonvulsant action of classic antiepileptic drugs, as well as the expression of CysLT receptors is altered by inflammation. In this study we showed that the inverse agonist of CysLT1 receptor, montelukast, synergistically increases the anticonvulsant action of phenobarbital against seizures induced in a model of acute injection of pentylenetetrazole (PTZ). Furthermore, it is shown that LTD4 (leukotriene D4) prevents the effect of montelukast. Isobolographic analysis revealed an ED50 mix value for a fixed-ratio combination (1:1 proportion) of montelukast plus phenobarbital of 0.06 ± 0.02 μmol, whereas the calculated ED50 add value was 0.49 ± 0.03 μmol. The interaction index was 0.12, indicating a synergistic interaction. Montelukast significantly decreased the antiseizure DE50 for phenobarbital (0.74 and 0.04 μmol in the absence and presence of montelukast, respectively) and, consequently, phenobarbital-induced sedation at equieffective doses. We also investigated whether the CysLT1 inverse agonist montelukast and a classical anticonvulsant, phenobarbital, decrease seizures in PTZ-kindled mice and CysLT receptor expression. Montelukast (10 mg/kg, s.c.) and phenobarbital (20 mg/kg, s.c.) increased the latency to generalized seizures in kindled mice. Montelukast increased CysLT1 immunoreactivity only in non-kindled PTZ-challenged mice. Interestingly, PTZ challenge decreased CysLT2 immunoreactivity only in kindled mice. CysLT1 antagonists seem to emerge as promising adjunct therapeutic agents in the treatment of refractory seizures. Notwithstanding, additional studies are necessary to evaluate the clinical implications of this work.
A epilepsia é uma doença que se manifesta por crises epilépticas recorrentes, não provocadas. Evidências sugerem que a inflamação desempenha um papel na patofisiologia destas crises. Embora os leucotrienos cisteínicos (CysLTs) tenham sido implicados no desenvolvimento de crises convulsivas, nenhum estudo investigou se o bloqueio dos receptores CysLT1 potencializa a ação anticonvulsivante de antiepilépticos clássicos, assim como se a expressão dos receptores de CysLT é alterada por inflamação. Neste estudo mostramos que o agonista inverso de CysLT1, montelucaste, sinergicamente aumenta a ação anticonvulsivante do fenobarbital contra crises convulsivas induzidas em um modelo de injeção aguda de pentilenotetrazol (PTZ). Além disso, é mostrado que o LTD4 (leucotrieno D4) previne o efeito do montelucaste. A análise isobolográfica revelou que o valor de DE50 mix, calculado experimentalmente para uma combinação de proporção 1: 1 de montelucaste e fenobarbital foi de 0,06 ± 0,02 umol, ao passo que o valor de DE50 add, calculado foi de 0,49 ± 0,03 umol. O índice de interação encontrado foi de 0,12, indicando uma interação sinérgica. A associação dos fármacos diminuiu significativamente o DE50 para o efeito anticonvulsivante do fenobarbital de 0,74 para 0,04 umol (na ausência e na presença de montelucaste, respectivamente) e, consequentemente, a sedação induzida por fenobarbital em doses equieficazes. Posteriormente foi avaliado se o montelucaste e o fenobarbital diminuem as crises convulsivas em animais previamente abrasados, assim como se o tratamento farmacológico ou o abrasamento alteram a expressão de receptores CysLTs. O montelucaste (10 mg/kg; s.c.) e o fenobarbital (20 mg/kg, s.c.) aumentaram a latência para crises convulsivas generalizadas em camundongos abrasados. O montelucaste aumentou a imunorreatividade do receptor CysLT1 em camundongos não abrasados e que foram desafiados por PTZ que não foram abrasados. Entretanto, o desafio de PTZ diminuiu a imunorreatividade do receptor CysLT2 apenas em camundongos abrasados. Antagonistas do receptor CysLT1 parecem emergir como agentes terapêuticos adjuntos promissores no tratamento de crises refratárias. Não obstante, estudos adicionais são necessários para avaliar as implicações clínicas deste trabalho.

APA, Harvard, Vancouver, ISO, and other styles

17

Morris, Nicola Louise. "A grounded theory study of the experiences of clinical psychologists working in crisis resolution and home treatment teams." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/37452/.

Full text

Abstract:

There has been a rapid development and implementation of Crisis Resolution Home Treatment Teams (CRHT) in the United Kingdom over the past decade. The available research studies of this service provision to date have largely focussed on issues related to the ‘outputs’ of CRHT, for example cost efficacy and the impact on admission rates. There is no available research on the experiences of clinical psychologists within CRHT. This is despite the fact that it would seem that research exploring the experiences of clinical psychologists in CRHT is important, as working in a new area of service provision may present specific challenges. An understanding of the nature of these challenges is considered important in order to support clinical psychologists in these settings, and to sustain and improve service delivery. This study presents a qualitative exploration of clinical psychologists’ experiences of working in a CRHT. Eleven clinical psychologists were interviewed about their perceptions of working within CRHT, their relationships with other professionals and their experiences of working with service users in ‘crisis’. The Grounded Theory approach was employed to analyse participants’ accounts. Three broad themes relating to ‘Psychological and Clinical Work’, ‘Teamwork’ and ‘Positive and Negative Aspects of CRHT Working’ were identified in the study. The emergent themes are compared to the wider literature on clinical psychologists’ experiences of working in teams, and working with service users in crisis. The findings have a range of implications for clinical practice in CRHT, service development and future research.

APA, Harvard, Vancouver, ISO, and other styles

18

Medeiros, Jo?o Paulo do Vale de. "Ecossocialismo: a g?nese de uma ecologia social em assentamentos de reforma agr?ria a partir dos movimentos sociais do campo." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/18243.

Full text

Abstract:

Made available in DSpace on 2014-12-17T15:55:03Z (GMT). No. of bitstreams: 1 JoaoPVM_DISSERT.pdf: 1440684 bytes, checksum: f894b737f60bc93063040e0cfaa91846 (MD5) Previous issue date: 2013-02-18
The world`s ecology crisis has in the capitalism way of production one of the possible causes. The unstopped search for the profits, into unlimited exploration of limited resources, made a huge transformation in human relationships with the nature, causing environment devastation, shortage of resources and species disappearance. Arises the necessity of question the society model that we are and which brings this crisis state, while we are impelled to search an alternative way. The ecosociallist praxis blows marxist principles with ecological matters, bringing important contributions regarding alternatives to capital/exploratory modus, advocating for a social fair society and environmentally sustainable. This way, by bibliographic review, we will research about this theory which have been growing in academic middles. In the same way, we will analyze the rural social movements paper in the construct of this reality. Throut the half estruture interviwes, bibliografic research and visities in the space of settlement called Moacir Lucena, that is today a exemple of rural resignification
A crise ecol?gica mundial tem no sistema de produ??o capitalista uma de suas poss?veis causas. A busca desenfreada pelo lucro, mediante a explora??o ilimitada de recursos limitados, operaram transforma??es de grande porte nas rela??es do ser humano com a natureza, provocando a devasta??o ambiental, escassez de recursos e desaparecimento de esp?cies. Surge ent?o a necessidade de questionarmos o modelo de sociedade em que estamos inseridos e que originou esse estado de crise, no mesmo passo que somos impelidos a buscar um alternativa. A pr?xis ecossocialista, que funde princ?pios marxistas e quest?es ecol?gicas, traz importante contribui??es no que se refere ? alternativas a esse modus capital/explorador, advogando por uma sociedade justa socialmente e ambientalmente sustent?vel. Dessa forma, por meio de revis?o bibliogr?fica, pesquisaremos a respeito dessa teoria que tem crescido nos meio acad?micos. No mesmo sentido, analisaremos qual o papel dos movimentos sociais do campo na constru??o dessa realidade. Por meio de entrevistas semi-estruturadas, pesquisas bibliogr?ficas e visitas de campo estudaremos a realidade do Assentamento Moacir Lucena, hoje exemplo de uma ressignifica??o do rural

APA, Harvard, Vancouver, ISO, and other styles

19

Hoffmann, Mauricio Scopel. "AVALIAÇÃO DA SUPLEMENTAÇÃO DE CREATINA EM RATOS COM TRAUMATISMO CRANIOENCEFÁLICO SOBRE A SUSCETIBILIDADE A CRISES EPILÉPTICAS." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/8985.

Full text

Abstract:

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul
This study presents an analysis on the effects of creatine supplementation on parameters of susceptibility to seizures induced by subconvulsant dose of pentylenetetrazol (PTZ) in an experimental rat model of traumatic brain injury (TBI). TBI is an acute neurological event that can lead to chronic neurological disease, such as epilepsy. Given the magnitude of the problem, various forms of therapy is being tested, but many have failed and yet, few take into account the susceptibility to seizures as an outcome and concentrate on a very early period of injury, getting away from the reality of patients in underdeveloped countries. Creatine is an interesting compound to be evaluated for this purpose, since it has neuromodulatory properties and may regulate synaptic plasticity in developing neurons. Thus, it became interesting to investigate whether there is any effect of creatine in this scenario. To this, creatine supplementation was held by gavage in rats subjected to fluid percussion TBI model and this supplementation began one week after TBI, once a day for four weeks. PTZ test was performed two hours after the last dose of creatine. Furthermore a similar protocol was performed to verify the persistence of the effect and secondly, to verify the acute effect of creatine, just before the PTZ test. Latency for myoclonic and tonic clonic seizures, total time of generalized seizure as the clinical severity through the scale of Racine were measured and also epileptiform discharges and spindle activity before and after the administration of PTZ were quantified. As main results, it was found a decreased susceptibility to seizures in rats supplemented by a month, and the effect remained even if there was withdrawal of creatine for a week, however, this effect was not observed in the single dose of the compound. Still, a positive correlation between epileptiform discharges and spindle activity was found, both reduced in animals supplemented continuously. Thus, creatine is presented as a candidate to be tested in studies with TBI, with the purpose of reducing the susceptibility to seizures.
Este trabalho apresenta uma análise dos efeitos da suplementação de creatina sobre parâmetros de suscetibilidade à crise epiléptica induzida por pentilenotetrazol (PTZ) em dose subconvulsivante, por modelo experimental de traumatismo cranioencefálico (TCE) em ratos. O traumatismo cranioencefálico (TCE) é um evento neurológico agudo que pode levar à doença neurológica crônica, como a epilepsia. Devido a magnitude do problema, diversas formas terapêuticas vêm sendo testadas, porém muitas falharam e ainda, poucas levam em conta o desfecho da suscetibilidade à crises epilépticas, além de se concentrarem em um período muito precoce da patologia, ficando longe da realidade dos pacientes de países subdesenvolvidos. A creatina consiste num interessante composto a ser avaliado para esse fim, já que apresenta propriedades neuromodulatorias e de regulação da plasticidade sináptica em neurônios em desenvovlimento. Assim, tornou-se interessante investigar se existe algum efeito da creatina nesse cenário. Para isso, realizou-se suplementação de creatina por gavagem em ratos submetidos ao TCE por percussão de fluído, iniciada esta suplementação uma semana após o TCE, uma vez ao dia, por quatro semanas, sendo o teste com PTZ realizado duas horas após a última dose. Também foi realizado um protocolo semelhante para verificar se o efeito da creatina era duradouro e outro, para verificar o efeito agudo, logo antes do teste com PTZ. Foram mensurados o tempo de latência para crises mioclônica e tônico clônica generalizada, tempo total de crise generalizada, gravidade da crise através da escala de Racine, bem como quantificada as descargas epileptiformes e ondas de fuso antes e após a administração de PTZ. Como resultados principais, encontrou-se a diminuição da suscetibilidade à crises epilépticas nos ratos suplementados por um mês, e o efeito permaneceu mesmo quando houve retirada da creatina por uma semana adicional, porém, esse efeito não foi observado na administração única do composto. Também houve correlação positiva do aparecimento de descargas epileptiformes e atividades de fuso, ambas reduzidas nos animais suplementados continuamente. Assim, a creatina apresenta-se como substância candidata à testes em estudos com traumatismo cranioencefálico, com a finalidade de diminuir a suscetibilidade à crises epilépticas.

APA, Harvard, Vancouver, ISO, and other styles

20

Decker, Richard E. Jr. "Production and Biocompatibility of Spider Silk Proteins in Goat Milk." DigitalCommons@USU, 2018. https://digitalcommons.usu.edu/etd/7288.

Full text

Abstract:

Due to its strength, flexibility, and biocompatibility, spider silk is a highly appealing material for applications in the medical field. Unfortunately, natural spider silk is difficult to obtain in large quantities because spiders are territorial and cannibalistic, making them impractical to farm. Synthetic spider silk proteins produced by transgenic hosts such as bacteria and goats have made it possible to obtain the quantities of spider silk needed to study it more fully and to investigate its potential uses. The spider silk proteins produced in our laboratory do not have an optimal purification method to remove all of the non-biocompatible contaminants and have not previously been tested for their biocompatibility. The first focus of this dissertation was to create goat cells that can be used to create new goats. These new goats will produce proteins that can be purified more efficiently and more completely. The second focus of this dissertation was to perform biocompatibility tests on goat-derived spider silk proteins. Prior to performing any biocompatibility tests, a method was established for removing endotoxins – an impurity that causes an immune response in the body – from the proteins. This work has shed light on areas for improvement in the silk protein purification process and laid groundwork for the production of new goat-derived proteins. These steps will help make it possible for synthetic spider silk to progress further toward becoming a viable biomaterial.

APA, Harvard, Vancouver, ISO, and other styles

21

Ruiz, Karine Pequeno Nakao. "Análise molecular de amostras negativas para o antígeno específico da próstata (PSA) coletadas de vítimas de crimes sexuais." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9469.

Full text

Abstract:

Submitted by Vasti Diniz (vastijpa@hotmail.com) on 2017-09-08T14:06:42Z No. of bitstreams: 1 arquivototal.pdf: 2742380 bytes, checksum: cf8f43acdec2329a5d6d78a8a373b6b7 (MD5)
Made available in DSpace on 2017-09-08T14:06:42Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2742380 bytes, checksum: cf8f43acdec2329a5d6d78a8a373b6b7 (MD5) Previous issue date: 2017-04-20
The finding of sperm through the screening tests on samples collected from rape victims confirms the occurrence of the sexual act, but its absence usually closes biological research in the crime in question, leaving a gap about the authorship of the crime, as well as about the criminal typification. The present work aimed to analyze the need of implementation in forensic routine of Genetics Laboratories of molecular analysis of negative samples to the prostate-specific antigen (PSA) collected from sex crimes victims. Vaginal swabs were selected and proceedings collected from 200 women who have been victims of those crimes in Paraíba from January 2015 to January 2016. Such materials had been sorted and presented negative result for PSA. Proceeded to the sample quantification by Real-time PCR using the Plexor® HY kit and there was a far greater concentration of autosomal DNA in relation to the male DNA. With the use of thermal cyclers GeneAmp® PCR System 9700, 200 DNA samples extracted from the sperm fraction (SF) were amplified for Y-STR with the use of PowerPlex® Y23 Systems and AmpFlSTR® Yfiler PCR Amplification kits. Such products have been subjected to capillary electrophoresis in genetic sequencer ABI PRISM™ 3500 Genetic Analyzer and the results analyzed by GeneMapper® ID software v 3.2. The fractions analyzed, only two full profiles amplification (1%), 24 (12%) partials, while the 174 remaining samples (87%) did not present any amplification. Screening with PSA testing negative served, statistically, how to determine guiding absence of sperm in swabs of vaginal origin and anally for victims of sex crimes. However, in this study were analyzed samples from rape victims. Due to the large social call caused by this type of crime, any nonzero statistic must be acceptable to a presumptive test. The results obtained have awakened to the need to study a new way of sorting this material, as well as the repetition of some analytical steps in order to get a genetic profile informative for illicit criminal resolution.
A constatação de espermatozoides, através dos testes de triagem, em amostras coletadas de vítimas de estupro confirma a ocorrência do ato sexual, todavia a sua ausência geralmente encerra a investigação biológica no crime em questão, ficando uma lacuna quanto à autoria do delito, bem como quanto à tipificação penal. O presente trabalho objetivou analisar a necessidade de implantação na rotina dos laboratórios de genética forense da análise molecular de amostras negativas para o antígeno específico da próstata (PSA) coletadas de vítimas de crimes sexuais. Foram selecionadas swabs vaginais e anais coletados de 200 mulheres que foram vítimas desses crimes na Paraíba entre os meses de janeiro de 2015 e janeiro de 2016. Tais materiais haviam sido triados e apresentaram resultado negativo para PSA. Procedeu-se à quantificação amostral por PCR em tempo real, com uso do kit Plexor® HY e observou-se uma concentração bem maior de DNA autossômico com relação ao DNA masculino. Com uso de termocicladores GeneAmp® PCR System 9700, 200 amostras de DNA extraído das frações espermáticas (FE) foram amplificadas para Y-STR com o emprego dos sistemas PowerPlex® Y23 System e AmpFlSTR® Yfiler® PCR Amplification. Tais produtos foram submetidos à eletroforese capilar em seqüenciador genético ABI PRISM 3500™ Genetic Analyzer e os resultados analisados pelo software GeneMapper® ID v3.2. Das frações analisadas, constatou-se amplificação de apenas dois perfis completos (1%), 24 parciais (12%), enquanto as 174 amostras restantes (87%) não apresentaram amplificação alguma. O teste de triagem com PSA negativo serviu, estatisticamente, como norteador para se determinar a ausência de esperma em swabs de origem vaginal e anal das vítimas de crimes sexuais. Contudo, no presente trabalho foram analisadas amostras provenientes de vítimas de estupro. Devido ao grande apelo social provocado por esse tipo de crime, nenhuma estatística diferente de zero deve ser aceitável para um teste presuntivo. Os resultados obtidos despertaram para a necessidade de estudar uma nova forma de triagem desse material, bem como pela repetição de alguns passos analíticos no intuito de se obter um perfil genético informativo para resolução do ilícito penal.

APA, Harvard, Vancouver, ISO, and other styles

22

Gould, Chandré. "South Africa's chemical and biological warfare programme 1981-1995." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1002396.

Full text

Abstract:

In 1981 the apartheid military initiated a chemical and biological warfare (CBW) programme (code-named Project Coast). The programme, terminated in 1993, was aimed at developing novel irritating and incapacitating agents for internal and external use, covert assassination weapons for use against apartheid opponents, and defensive equipment for use by South African Defence Force (SADF) troops in Angola. The CBW programme was driven by a single individual, Dr Wouter Basson, who reported to a military management committee (the Co-ordinating Management Committee) which comprised a select group of high ranking officers. Practical and financial oversight of the programme was weak which allowed both for the abuse of programme funds and for senior military officers to deny knowledge of aspects of the programme. The biological component of Project Coast was conducted in violation of the commitments of the South African government to the Biological and Toxins Weapons Convention (BTWC). While the state’s commitment to the BTWC was one of the factors considered when initiating the programme, it was not a sufficient constraint to prevent the development of the biological weapons programme, but rather influenced its structure such that the programme could avoid national and international detection. Despite efforts to conceal the military front companies where the chemical and biological warfare (CBW) research and development was undertaken, evidence presented in this thesis shows that the United States had sufficient information about the programme to have been aware of its existence. Yet, it was only in 1993, on the eve of the democratic election in South Africa, that any attempt was made by the US administration to pressure the government to terminate the programme. This thesis considers the factors which influenced the decision to develop Project Coast; the structure and nature of the programme; the motivations of scientists to become involved in the programme and remain involved; the use of chemical and biological agents against opponents of the state, and the factors which influenced the termination of the programme on the eve of the first democratic elections in 1994. It also considers the nature and exent of international support, both tacit and overt, for the programme and argues that the failure of Western nations to call for the termination of the programme before the early 1990s was a function of political expediency and indicates a significant weakness in the ability of international agreements to constrain the development of such programmes.

APA, Harvard, Vancouver, ISO, and other styles

23

Taufer, Clarissa Reginato. "Avaliação da diferenciação de células da crista neural de aves sobre matrizes de PuraMatrix." reponame:Repositório Institucional da UFSC, 2017. https://repositorio.ufsc.br/xmlui/handle/123456789/180701.

Full text

Abstract:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Florianópolis, 2017.
Made available in DSpace on 2017-11-07T03:25:46Z (GMT). No. of bitstreams: 1 347991.pdf: 3464947 bytes, checksum: 4b9adce4d95c51c30b0828be864fb06e (MD5) Previous issue date: 2017
A crista neural (CN) é composta por células heterogêneas e multipotentes, e pode ser dividida em CN cefálica (CNC) e truncal (CNT). As células da CNC originam, in vivo, células neurais e mesenquimais, neste último caso, formando parte do esqueleto craniofacial (condrócitos, osteócitos e odontoblastos) e tecido conjuntivo da face (adipócitos e fibroblastos dermais). As células da CN truncal (CNT), por sua vez, originam in vivo, células gliais e neurônios do sistema nervoso periférico, além de células cromafins do sistema endócrino. Melanócitos são formados por células da CNC e CNT. In vivo, as células da CNT não apresentam a capacidade de se diferenciarem em fenótipos mesenquimais. Entretanto, in vitro, sob estímulo com fatores químicos e físicos, estas células podem se diferenciar em condrócitos, osteócitos e adipócitos. Frente a estas capacidades que as células da CNT apresentam in vitro, avaliamos a utilização de uma matriz sintética e pura chamada PuraMatrix , para cultivo e diferenciação de células da CNT. Inicialmente, testamos e padronizamos anticorpos para marcação de osteócitos (SB-1, SB-2, SB-3 e SB-5) em membros posteriores de embriões de codornas. Em seguida, realizamos culturas de células da CNT com embriões de 18-22 pares de somitos, com meio básico de cultivo e com adição de Fatores de Diferenciação Mesenquimais (FDM) para estimular as células a se diferenciarem em adipócitos e osteócitos. Foram testadas as concentrações de PuraMatrix 0,15%; 0,25%, 0,5% e 1%. Análises fenotípicas de frequência e quantitativas através da técnica de imunocitoquímica e colorações específicas foram realizadas nos 14º e 21º dias de cultivos para todos os fenótipos da CN. As quatro concentrações de PuraMatrix suportaram o cultivo de células da CNT. Entretanto, pelo baixo número de células observado, a concentração de PuraMatrix 1% foi descartada de nossas análises. As concentrações de PuraMatrix 0,15%; 0,25% e 0,5% possibilitaram a diferenciação de células da CNT para células gliais, neurônios, melanócitos, células musculares lisas e condrócitos, tanto em culturas controles quanto estimuladas com FDM. Adipócitos estiveram presentes nas três concentrações quando estimuladas com FDM, e também nas concentrações de PuraMatrix 0,15% e 0,25% na condição controle. Osteócitos foram analisados nas duas concentrações mais baixas de PuraMatrix , onde marcações para SB-3 ocorreram, mas em co-localização com cartilagem, assim como observado in vivo. SB-5 mostrou-se muito específico para osteoblastos/osteócitos e apresentou marcação tanto em cultivos controles quanto tratados. Apenas no 21º dia, houve marcação de alcalina fosfatase e de matriz mineralizada. PuraMatrix abre novas perspectivas para o desenvolvimento de estudos clonais de progenitores da CN e poderá permitir a identificação de novos progenitores com as potencialidades neurais-mesenquimais para CNT.
Abstract : The neural crest (NC) is composed of heterogenous and multipotent cells, and can be divided into cephalic (CNC) and trunkal (TNC) NC. CNC cells originate, in vivo, neural and mesenchymal cells, the last one forming part of the craniofacial skeleton (chondrocytes, osteocytes and odontoblasts) and connective tissue of the face (adipocytes and dermal fibroblasts). The TNC cells, in turn, originated in vivo, glial cells and neurons of the peripheral nervous system, in addition to chromaffin cells of the endocrine system. Melanocytes are formed by CNC and TNC cells. In vivo, TNC cells don?t have the ability to differentiate into mesenquimal phenotypes. However, in vitro, under stimulation with chemical and physical factors, these cells can differentiate into chondrocytes, osteocytes and adipocytes. Faced with these capabilities that TNC cells present in vitro, we evaluated the use of a pure synthetic matrix called PuraMatrix , for TNC cell culture and differentiation. Initially, we tested and standardized antibodies for marking osteocytes (SB-1, SB-2, SB-3 and SB-5) on hind limbs of quail embryos. Then, we performed cell cultures of TNC cells with embryos of 18-22 pairs of somites, with basic culture medium and with addition of Mesenchymal Differentiation Factors (MDF) to stimulate the cells to differentiate into adipocytes and osteocytes. The concentrations of PuraMatrix 0.15%; 0.25%, 0.5% and 1% were tested. Frequency and quantitative phenotypic analyzes using the immunocytochemistry technique and specific staining were performed on the 14th and 21st day of cultures for all NC phenotypes. The four concentrations of PuraMatrix supported the cultivation of CNT cells. However, due to the low number of cells observed, the concentration of PuraMatrix 1% was discarded from the analyzes. The concentrations of PuraMatrix 0.15%; 0.25% and 0.5% allowed the differentiation of TNC cells into glial cells, neurons, melanocytes, smooth muscle cells and chondrocytes in both control and MDF stimulated cultures. Adipocytes were present in the three concentrations when stimulated with MDF, and also in the concentrations of PuraMatrix 0.15% and 0.25% in the control condition. Osteocytes were analyzed for the two lowest concentrations of PuraMatrix , where SB-3 marker occurred with co-localization with cartilage as well as observed in vivo. SB-5 showed to be very specific for osteoblasts/osteocytes and showed labeling in both control and treated cultures. On day 21 only, there was marking of alkaline phosphatase and mineralized matrix. PuraMatrix opens new perspectives for the development of clonal studies of NC progenitors and may allow the identification of new progenitors with the neural-mesenchymal potentialities for TNC.

APA, Harvard, Vancouver, ISO, and other styles

24

Reschke, Cristina Ruedell. "RECEPTORES EP1 E EP3 MODULAM AS CRISES EPILÉPTICAS INDUZIDAS POR PENTILENOTETRAZOL E ÁCIDO CAÍNICO EM CAMUNDONGOS." Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/3852.

Full text

Abstract:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Epilepsy is one of the most common neurologic disorders. It has been suggested that seizures may be facilitaded by inflammation. PGE2 is one of the most important inflammatory mediators, and facilitates pentylenetetrazol (PTZ)-induced seizures by stimulating EP1 and EP3 receptors. However, up to the present moment, no study has investigated whether EP1 and EP3 receptors blocking attenuate seizures induced by convulsants other than PTZ. It is also unknown whether Na+,K+-ATPase activity alterations are involved in such an effect. Therefore, in the current study we investigated whether EP1 and EP3 ligands (agonists and antagonists) modulate PTZ- and kainic acid (KA)-induced seizures, and whether alterations in Na+,K+-ATPase activity mediate such a protective effect, in mice. EP1 and EP3 antagonists (ONO-8713 and ONO-AE3-240, respectively, 10 Og/kg, s.c.) attenuated PTZ (60 mg/kg, i.p.)- and KA (20 mg/kg, i.p.)-induced seizures. The respective agonists (ONO-DI-004 and ONO-AE-248, 10 Og/kg, s.c.) facilitated seizures in both acute models, and at noneffective doses, prevented the protective effects of the antagonists. Animals injected with PTZ presented decreased Na+,K+-ATPase activity in the cerebral cortex and hippocampus. On the other hand, animals injected with KA presented increased Na+,K+-ATPase activity in the same cerebral structures at the end of the experiment. These divergent findings suggest that alterations in Na+,K+-ATPase activity in both acute models depends on the convulsant agent used and make difficult to establish a relationship between Na+,K+-ATPase activity and seizure development. Moreover, EP1 and EP3 antagonists administration abolished Na+,K+- ATPase activity alterations induced by PTZ and KA, in such a way that these alterations seem to be related more to the presence of ictal phenomenon itself than to the seizure induction mechanisms. Notwithstanding, the currrent results clearly show that EP1 and EP3 receptors might constitute novel targets for anticonvulsants development, since EP1 and EP3 decreased seizures, regardless of the convulsant agent used.
A epilepsia é uma das disfunções neurológicas mais comuns. Tem sido sugerido que as crises epilépticas podem ser facilitadas pela ocorrência de inflamação. A PGE2 é um dos mediadores inflamatórios mais importantes que, agindo por meio dos receptores EP1 e EP3, facilita as convulsões induzidas por pentilenotetrazol (PTZ). Contudo, até a presente data, nenhum estudo investigou, de maneira sistêmica, se a ativação ou bloqueio de receptores EP1 e EP3 facilitam as convulsões induzidas por outros agentes; tampouco se alterações na atividade da Na+,K+-ATPase estão envolvidas nesse efeito. Assim, no presente estudo, investigamos se ligantes (agonistas e antagonistas) de receptores EP1 e EP3 modificam as crises induzidas por PTZ e ácido caínico (KA), e se tais efeitos estão associados a alterações na atividade da enzima Na+,K+-ATPase, em camundongos. Os antagonistas EP1 e EP3 (ONO-8713 e ONO-AE3-240, respectivamente, 10 Og/Kg, s.c.) atenuaram as convulsões induzidas por PTZ (60 mg/Kg, i.p.) e KA (20 mg/Kg). Os seus respectivos agonistas (ONO-DI-004 e ONO-AE-248 de 10 Og/Kg, s.c.) facilitaram as convulsões em ambos modelos agudos de crises epilépticas e, em doses não efetivas para gerar crises, preveniram os efeitos dos antagonistas. Os animais submetidos à administração de PTZ apresentaram, ao final do experimento, a atividade Na+,K+-ATPásica diminuída no córtex cerebral e hipocampo. Por outro lado, animais tratados com KA apresentaram um aumento na atividade Na+,K+-ATPásica nestas mesmas estruturas, que se correlacionou positivamente com a vigência de status epilepticus no momento do sacrifício. Os achados divergentes no que diz respeito à alteração da atividade da Na+,K+-ATPase nos dois modelos de crises agudas sugere que tais alterações estejam relacionadas ao tipo de agente convulsivante utilizado, e dificultam estabelecer, de forma inequívoca, uma relação entre atividade desta ATPase e sensibilidade à crises agudas. Ademais, a administração de antagonistas EP1 e EP3 aboliu as alterações da atividade da Na+,K+-ATPase induzidas tanto por PTZ como por KA, de tal forma que estas parecem estar mais associadas com o fenômeno ictal em si, do que com os mecanismos de indução da crise. Contudo, os resultados mostram de forma clara que os receptores EP1 e EP3 podem se constituir possíveis novos alvos para o desenvolvimento de drogas antiepilépticas, pois antagonistas EP1 e EP3 diminuíram as crises, independente do agente convulsivante utilizado.

APA, Harvard, Vancouver, ISO, and other styles

25

Merisio, Paulo Roberto. "Avaliação de marcadores de lesão endotelial nas crises vasoclusivas das doenças falciformes / Paulo Roberto Merisio ; orientadora, Mara Albonei Dudeque Pianovski." reponame:Biblioteca Digital de Teses e Dissertações da PUC_PR, 2012. http://www.biblioteca.pucpr.br/tede/tde_busca/arquivo.php?codArquivo=2453.

Full text

Abstract:

Dissertação (mestrado) - Pontifícia Universidade Católica do Paraná, Curitiba, 2012
Bibliografia: f. 50-61
Pacientes com doenca falciforme podem apresentar crises clinicas que prejudicam sua qualidade de vida. Com o intuito de contribuir para o conhecimento da fisiopatologia foi desenvolvido o presente trabalho tendo como objetivo analisar marcadores endotelia
Patients with sickle cell disease may have clinical seizures that impair their life quality. The aim of this study was to analyze endothelial markers in children and adolescents with sickle cell disease in order to contribute to the knowledge of this path

APA, Harvard, Vancouver, ISO, and other styles

26

O’Brien, Colleen. "DARK EMBRACE: ORESTES COMPLEX, CATATHYMIC CRISIS AND METHOD OF MURDER. A STUDY OF MATRICIDE IN A FORENSIC PSYCHIATRIC SAMPLE." Thesis, Laurentian University of Sudbury, 2014. https://zone.biblio.laurentian.ca/dspace/handle/10219/2197.

Full text

Abstract:

A study was conducted to investigate and identify differences inherent in two subtypes of psychosis driven or mentally disordered homicide: matricide versus any other biological intrafamilial homicide or attempted homicide. Matricide was further investigated through the exploration of offence specific details, as well as demographic and diagnostic characteristics of persons who had committed (or attempted) homicide against the mother and were subsequently found not criminally responsible and detained by the Ontario Review Board between 1992 and 2012. Matricidal accused were more often diagnosed with childhood disorders and paranoid schizophrenia. As adults, they failed to mature sexually and socially, and continued to live at home, dependent on the mothers that were the ultimate victims of their violence. Attachment theory is offered as a proposed explanation for the matricidal impulse.

APA, Harvard, Vancouver, ISO, and other styles

27

Schwengber, Solange Pereira. "Utilização de marcadores de cromossomo Y como ferramenta visando a elucidação de casos de crimes sexuais na genética forense." Pontifícia Universidade Católica do Rio Grande do Sul, 2008. http://hdl.handle.net/10923/1360.

Full text

Abstract:

Made available in DSpace on 2013-08-07T18:41:47Z (GMT). No. of bitstreams: 1 000405027-Texto+Parcial-0.pdf: 58857 bytes, checksum: 3137651cc6ea0e3ba8d2644d92086797 (MD5) Previous issue date: 2008
Marcadores moleculares de cromossomo Y são essenciais à perícia em genética forense. Os marcadores moleculares STR (Short Tandem Repeats) específicos para o cromossomo Y são amplamente utilizados nos Laboratórios de Perícias. Entretanto, não havia dados estatísticos próprios do Estado do Rio Grande do Sul, implicando na utilização de bancos de dados alternativos (brasileiro e europeu). Assim, a formação de um banco de dados de haplótipos, próprio da população do RS, com os perfis do cromossomo Y, permitiria a emissão de Laudos Periciais com informações estatísticas mais fidedignas. Neste trabalho foram tipados 255 indivíduos não aparentados, pertencentes a sete mesoregiões do estado do Rio Grande do Sul. Foram colhidas amostras de sangue ou saliva a partir das quais foi feita a extração de DNA, seguida da amplificação dos 17 loci do cromossomo Y através do kit Y-STRs (AmpF=iSTR® YfilerTM - Applied Biosystems). Os produtos de amplificação foram analisados no ABI PRISM® 3100 Avant Genetic Analyzer (Applied Biosystems).Na análise dos dados foram identificados 247 haplótipos, dos quais 239 únicos e 8 foram encontrados em dois indivíduos, cada. A diversidade haplotípica de Y-STRs da população do Rio Grande do Sul foi de 99,98% e o poder de discriminação de 96,86%. As distâncias genéticas mostraram que a população do RS, como um todo, não é significativamente diferente das amostras do Brasil, Rio de Janeiro e Argentina; é marginalmente diferente de São Paulo, Itália e do Norte de Portugal; mais distante da Espanha, região Amazônica e Alemanha; e muito distante da amostra de nativos sul-americanos. Quando os dados do RS foram comparados por mesoregião, alguns pares apresentaram diferença significativa entre si, de acordo com a história da imigração, sendo a Mesoregião Centro Oriental Rio-Grandense a mais diferente. Porém, nenhuma região apresentou diferença significativa em relação à população brasileira.

APA, Harvard, Vancouver, ISO, and other styles

28

Younis, Shady. "Functional characterization of the biological significance of the ZBED6/ZC3H11A locus in placental mammals." Doctoral thesis, Uppsala universitet, Institutionen för medicinsk biokemi och mikrobiologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-329190.

Full text

Abstract:

The recent advances in molecular and computational biology have made possible the study of complicated transcriptional regulatory networks that control a wide range of biological processes and phenotypic traits. In this thesis, several approaches were combined including next generation sequencing, gene expression profiling, chromatin and RNA immunoprecipitation, bioinformatics and genome editing methods in order to characterize the biological significance of the ZBED6 and ZC3H11A genes. A mutation in the binding site of ZBED6, located in an intron of IGF2, disrupts the binding and leads to 3-fold upregulation of IGF2 mRNA in pig muscle tissues. The first part of the thesis presents a detailed functional characterization of ZBED6. Transient silencing of ZBED6 expression in mouse myoblasts led to increased Igf2 expression (~2-fold). ChIP-seq analysis of ZBED6 and histone modifications showed that ZBED6 preferentially binds active promoters and modulates their transcriptional activities (paper I). In the follow-up studies using CRISPR/Cas9 we showed that either the deletion of ZBED6 or its binding site in Igf2 (Igf2ΔGGCT) led to more than 30-fold up-regulation of Igf2 expression in myoblasts. Differentiation of these genetically engineered cells resulted in hypertrophic myotubes. Transcriptome analysis revealed ~30% overlap between the differentially expressed genes in Zbed6-/- and Igf2ΔGGCT myotubes, with significant enrichment of muscle-specific genes. ZBED6-overexpression in myoblasts led to cell cycle arrest, reduced cell viability, reduced mitochondrial activities and impaired the differentiation of myoblasts (paper II). Further studies on cancer cells showed that ZBED6 influences the growth of colorectal cancer cells with dramatic changes in the transcription of hundreds of cancer-related genes (paper III). The phenotypic characterization of Zbed6-/- and Igf2pA/mG mouse models showed that the ZBED6-Igf2 axis has a major effect on regulating muscle growth and the growth of internal organs. Transcriptome analysis demonstrated a massive up-regulation of Igf2 expression (~30-fold) in adult tissues, but not in fetal tissues, of transgenic mice (paper IV). In the second part of the thesis we investigated the cellular function of Zc3h11a, the gene harboring ZBED6 in one of its first introns. The function of the ZC3H11A protein is so far poorly characterized. We show that ZC3H11A is a novel stress-induced protein that is required for efficient mRNA export from the nucleus. The inactivation of ZC3H11A inhibited the growth of multiple viruses including HIV, influenza, HSV and adenoviruses (paper V).

APA, Harvard, Vancouver, ISO, and other styles

29

Pereira, Charlane Kelly Souto. "Estudo da ação psicofarmacológica de Herissantia crispa (L.) Brizicky (Malvaceae)." Universidade Federal da Paraíba, 2009. http://tede.biblioteca.ufpb.br:8080/handle/tede/6761.

Full text

Abstract:

Made available in DSpace on 2015-05-14T12:59:45Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 884408 bytes, checksum: 448afd42d1cb8f67ef7beee9503e0735 (MD5) Previous issue date: 2009-11-11
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Herissantia crispa (L.) Brizicky popularly know as malvaísco is a plant which belongs to the Malvaceae family. There aren t many reports about H. crispa, however, steroids, flavonoids and glycosidic flavonoids with pharmacological activity have been isolated from this species. Other species of Malvaceae have been used in traditional medicine and many studies have shown activities such as anti-inflammatory, antinociceptive, diuretic and others. The aim of this work was to evaluate a possible psychopharmacological activity of H. crispa ethanolic crude extract (EEHc) performing a central nervous system (CNS) investigation in mice. Initially, behavioral pharmacological screening was performed to assess the possible effect of EEHc on the nervous system. Some behavioral changes were observed similar to that of CNS depressant drugs in treated mice. No death was observed 72 hours after treatment with EEHc, nor toxic signs on the highest dose (2000 mg/Kg, i.p.). Therefore we established the doses 500 or 800 mg/kg to perform the pharmacological tests. None of the two doses reduced the time of permanence of mice on a rota-rod revolving bar. On the open-field test, both doses of EEHc significantly reduced ambulation, rearing and defecation, suggesting a profile that resembles hypnotic-sedative drugs. The EEHc treatment did not affect grooming. There were no differences between the control group and the EEHc treated groups when mice were tested for differences in anxiety-related behavior on the elevated plus maze or electroshock- induced tonic convulsions triggered by auricular shock, suggesting that EEHc does not have anxiolytic or anticonvulsant effects. Both doses of EEHc significantly increased the duration of sleeping time induced by sodium thiopental but failed to increase the latency of thiopental-induced hypnosis. Regarding the antinociceptive tests, EEHc significantly reduced acetic acid-induced abdominal writhes in a non dose-dependent manner. EEHc at 500 mg/kg also significantly reduced the hot-plate latency time only 60 minutes after treatment. In the formalin test, EEHc at 500 mg/kg was only able to reduce licking paw time in the first phase of the test. EEHc at the dose of 800 mg/kg reduced licking paw time the first and second phases. These results support the evidence of a central antinociceptive action. In order to confirm the central antinociceptive activity of EEHc, mice were treated with naloxona, an opioid antagonist, and them submitted to formalin test. Since the effect of the EEHc was not reverted by naloxone is excluded the participation of the opioid system in the mechanism of this activity. Therefore, an results suggest that EEHc presented evidences a sedativehypnotic drug profile with central non-opioid antinociceptive activity.
A espécie Herissantia crispa (L.) Brizicky, popularmente conhecida como malvaísco, é uma planta pertencente à família Malvaceae. Não há muitos relatos sobre H. crispa na literatura, no entanto, esteróides, flavonóides e glicosídeos flavonoídicos com atividades comprovadas foram isolados desta planta. Outras espécies da família Malvaceae são usadas na medicina tradicional e estudos comprovaram atividades anti-inflamatórias, antinociceptivas, diuréticas, entre outras. O objetivo do presente trabalho foi avaliar as possíveis ações psicofarmacológicas do extrato etanólico de Herissantia crispa (EEHc), pela investigação de seus efeitos no sistema nervoso central (SNC), em camundongos. Inicialmente, foi realizada a triagem farmacológica comportamental, para verificar o possível efeito do EEHc no sistema nervoso. Algumas alterações comportamentais semelhantes às de drogas depressoras do SNC foram observadas nos camundongos tratados, tais como, redução da ambulação e pequeno grau de ptose. Nas 72 horas seguintes não houve morte dos animais, nem presença de sinais tóxicos na maior dose possível (2000 mg/kg i.p), sendo estabelecidas as doses de 500 e 800 mg/kg para os testes subsequentes. Nenhuma das doses testadas do EEHc diminuíram o tempo de permanência dos animais na barra giratória no teste do rota-rod. No teste do campo aberto, as duas doses testadas do EEHc diminuíram significativamente a ambulação, o comportamento de levantar e a defecação, sugerindo perfil semelhante ao de drogas sedativo-hipnóticas. O comportamento de autolimpeza não foi alterado por nenhuma dose. O tratamento dos animais com o EEHc nas doses testadas não alteraram seu comportamento no teste do labirinto em cruz elevado e também não protegeram os animais contra as convulsões induzidas pelo eletrochoque auricular, descartando-se os efeitos ansiolítico e anticonvulsivante, respectivamente. As doses de 500 e 800 mg/kg do EEHc induziram significante potencialização do tempo do sono induzido pelo tiopental, no entanto, não alteraram a latência de indução do sono, característica semelhante à de drogas sedativa-hipnóticas. Na avaliação da atividade antinociceptiva, o EEHC reduziu significativamente o número de contorções abdominais, evidenciando atividade antinociceptiva. Tal efeito não foi dose dependente, pois foi mais pronunciado na dose de 500mg/kg do que na dose de 800mg/kg. No teste da placa quente o EEHc aumentou o tempo de latência ao estímulo térmico apenas na dose de 500 mg/kg, 60 minutos após o tratamento. No teste da formalina, o EEHc na dose de 500 mk/kg só foi capaz de reduzir o tempo de lambida na primeira fase do teste, mas a dose de 800 mg/kg reduziu o tempo de lambida da pata na primeira e segunda fase do teste , confirmando assim o efeito antinociceptivo de ação central. Para detalhar essa atividade antinociceptiva, realizou-se o teste da formalina submetendo os animais a um tratamento prévio com a naloxona, um antagonista opióide, no entanto, o efeito antinociceptivo não foi revertido, excluindo assim a participação do sistema opióide no mecanismo desta atividade. Portanto, baseado nos resultados obtidos no presente estudo, o EEHC apresentou características de drogas com perfil sedativo-hipnótico e atividade antinociceptiva central, sem participação do sistema opióide.

APA, Harvard, Vancouver, ISO, and other styles

30

Valladares, Rodrigo, and Hanna Briheim. "Metoder och tillämpningar av CRISPR-Cas9 i cancerforskning. : Samt hur CRISPR-Cas9 kan implementeras i skolundervisningen." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-166140.

Full text

Abstract:

CRISPR-Cas9 är ett effektivt genredigeringsverktyg som har upptäckts på senare år. Verktyget härstammar från ett adaptivt immunförsvar hos prokaryoter. Tekniken används för att modifiera DNA hos växter, djur och människor på ett enkelt och billigt sätt. CRISPR-Cas9 har visat sig ha stor potential vid bekämpning av olika sjukdomar däribland cancer som idag är ett globalt hälsoproblem. Inom cancerforskningen ses CRISPR-Cas9 som ett lovande verktyg vid cancerterapi och läkemedelsutveckling. I denna studie sammanställer vi aktuella metoder och användningsområden med CRISPR-Cas9 inom cancerforskning. Dessutom undersöker vi hur denna form av genteknik kan lyftas upp och tillämpas i biologiundervisningen.
CRISPR-Cas9 has recently emerged as an effective genome editing tool. The tool derives from an adaptive immune system in prokaryotes. The technology is used for modification of DNA in plants, animals and humans in a simple and inexpensive way. CRISPR-Cas9 has shown great potential in fighting different diseases like cancer which today is a global health issue. It is seen as a promising tool for cancer research when it comes to cancer therapy and drug development. Here we summarize current methods and applications of CRISPR-Cas9 for cancer research. Furthermore, we explore the possibilities of introducing and applying this kind of genetic engineering in biology teaching.

Framläggning, opponering och respondering skedde skriftligt till följd av covid19.

APA, Harvard, Vancouver, ISO, and other styles

31

Ramos, Hryb Ana Belén. "Avaliação do potencial de diferenciação das células da crista neural truncal de aves cultivadas sobre Matrigel." reponame:Repositório Institucional da UFSC, 2013. https://repositorio.ufsc.br/handle/123456789/106862.

Full text

Abstract:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Florianópolis, 2013.
Made available in DSpace on 2013-12-05T22:35:37Z (GMT). No. of bitstreams: 1 320037.pdf: 1679970 bytes, checksum: ef7c5e9994dac949503795a373ca9fb2 (MD5) Previous issue date: 2013
A Crista Neural (CN) constitui uma população de células que emergem a partir das pregas dorsais do neuroepitélio durante a neurulação. Estas células migram ao longo de todo o eixo antero-posterior embrionário dos vertebrados até encontrarem seus locais definidos onde irão diferenciar em diversos derivados neurais e mesenquimais. As células da CN cefálica (CNC) e da CN Truncal (CNT) podem dar origem a neurônios e células gliais do sistema nervoso periférico, melanócitos e células endócrinas. Diferentemente do que ocorre com a CNC, a CNT possui uma limitada capacidade de originar elementos mesenquimais in vivo. Entretanto, sob determinadas condições in vitro, a CNT pode originar fenótipos mesenquimais. Até o momento, a maior parte dos estudos com a CNT foram realizados sobre substratos bidimensionais (2D), geralmente revestidos moléculas isoladas da matriz extracelular (colágeno, laminina, fibronectina) ou sobre monocamadas de fibroblastos embrionários (3T3). Atualmente, sabe-se que este tipo de ambiente não reflete a complexa fisiologia dos tecidos in vivo. No presente estudo nós realizamos cultivos de células isoladas da CNT sobre um extrato solúvel da membrana basal, comumente denominado de Matrigel. Elaboramos uma metodologia que permitiu criar dois microambientes dentro do mesmo poço de cultivo: um ambiente bidimensional (2D) e um ambiente tridimensional (3D). Verificamos que o Matrigel permite a diferenciação dos principais fenótipos da CNT (neurais: células gliais, células musculares lisas, neurônios, melanócitos e mesenquimais: condrócitos). Embora tenham sido observadas algumas variações na obtenção dos fenótipos descritos conforme o lote de Matrigel utilizado, o uso de uma mistura destes lotes permitiu normalizar a frequência de poços de cultivo contendo cada tipo celular. Além disso, 70% dos poços de cultivo apresentavam nódulos de cartilagem, os quais frequentemente se encontravam na região 3D. Interessantemente, esta frequência de condrócitos detectada utilizando um microambiente 3D de Matrigel, resultou ser muito maior quando comparado a trabalhos anteriores realizados sobre ambientes 2D convencionais. Estes dados sugerem que o Matrigel pode ser um ótimo substrato para estudar a diferenciação e multipotencialidade das células da CN.
Abstract : The Neural Crest (NC) is a cell population that detach from dorsal neural folds during neurulation. These cells migrate along the entire vertebrate embryonic axis until they find their final destination and differentiate into both neural and mesenchymal phenotypes. Cephalic NC (CNC) and Trunk NC cells (TNCCs) give rise to neurons and glia from the peripheral nervous system, melanocytes and endocrine cells. Differently from CNC, TNC have a limited capacity to give rise to mesenchymal derivatives in vivo. Nevertheless, under special culture conditions, TNC can give rise to mesenchymal phenotypes. Until now, most of studies of TNC were conducted on 2D substrates, usually covered with extracellular matrix molecules (e.g. collagen, laminin, fibronectin) or under fibroblast feeder-layers (3T3). Nowadays, it is worth knowing that this kind of environment does not mimic the complex tissue physiology in vivo. In the present study, we conducted cell cultures isolated from TNC on a soluble extract of basal membrane, commonly named Matrigel. We performed a new methodology that permitted to create two microenvironments in the same culture well: a two-dimensional (2D) and a three-dimensional (3D) environment. We observed that Matrigel permits the differentiation of the main TNC phenotypes (glial cells, melanocytes, smooth muscle cells, neurons and chondrocytes). Even though we observed some described variations on the phenotypes obtained according to the Matrigel lot used, the use of a mixture of lots allowed normalizing the frequency of culture wells containing each cell type. Moreover, 70% of culture wells contained cartilage nodules, which were frequently on the 3D zone. Interestingly, this frequency of chondrocytes detected using a 3D microenvironment of Matrigel resulted even higher than previous reports performed on traditional 2D cultures. Together, this data suggest that Matrigel could be an excellent substrate to study NC differentiation and multipotenciality.

APA, Harvard, Vancouver, ISO, and other styles

32

Paladini, L. "BIOLOGICAL SIGNIFICANCE OF ALTERATIONS IN BRCA1 AND BRCA2 GENES AND RESPONSE TO DNA DAMAGE AGENTS IN HEREDITARY BREAST CANCER." Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/488444.

Full text

Abstract:

Background: Although the large number of studies investigating BRCA mutations and their clinical role in different populations and ethnicities, there is a lack of a systematic analysis on these alterations in Italian cohorts, including the analysis of Variants of Unknown biological and clinical Significance (VUS). Moreover, correct management of breast cancer patients tested positive for alterations in BRCA1 or BRCA2 genes is still controversial. We aimed to assess the biological and clinical relevance of BRCA alterations in a consecutive cohort of hereditary breast cancer patients, with particular attention to VUS. Methods: Genetic and clinical data from 366 patients with familial history of breast cancer were reviewed. The association between clinical-pathological, molecular data, and breast cancer patient subgroups was assessed. BRCA1/2 and γ-H2AX expression levels were assessed by qRT-PCR and IHC for all tumors. In silico protein prediction models were computed for VUS with potential clinical significance. Cell proliferation and apoptosis assays for CRISPR/Ca9s-generated mutant MDA-MB-231 cell line were performed to evaluate the sensitivity of specific VUS to DNA damage agents. Results: Overall, 73 breast cancer patients (20%) tested positive for BRCA1/2 alterations. BRCA1 and BRCA2 mutations were reported in 34 (46.5%) and 15 (20.5%) patients, respectively. Two patients (3%) showed two concurrent mutations in both genes. Twenty-two patients (30%) tested positive for VUS. Breast cancer family history and early onset of disease were significantly associated with BRCA1 (p < 0.001) and BRCA2 (p = 0.045 and p = 0.005) mutations. Triple-negative histotype, grading 3, and high Ki-67 levels were significantly associated with BRCA1 mutations (p < 0.001). Molecular, in silico and in vitro experiments confirmed the deleterious effect of BRCA1 c.5509T>C VUS, which was associated with significant high levels of DNA damage and greater sensitivity to Olaparib compared to Cisplatin treatment. Conclusions: Our study supports the deleterious effect of the BRCA1 c.5509T>C VUS in hereditary breast cancer patients, and suggests that breast cancer patient carriers of this variant could benefit from an intense surveillance and from a single agent treatment with Olaparib avoiding various side effects of chemotherapy treatment.

APA, Harvard, Vancouver, ISO, and other styles

33

Pereira, Charlane Kelly Souto. "Atividade antinociceptiva e anti-inflamatória de Herissantia crispa (L.) Brizicky em camundongos." Universidade Federal da Paraíba, 2013. http://tede.biblioteca.ufpb.br:8080/handle/tede/6820.

Full text

Abstract:

Made available in DSpace on 2015-05-14T13:00:02Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1186433 bytes, checksum: a2657e7816d226f92f3431c0227b0dbc (MD5) Previous issue date: 2013-09-09
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The Herissantia crispa (L.) Brizicky (Malvaceae), is composed of substances that have proven activities, such as anti-inflammatory, antinociceptive and antioxidant. There are few reports in the literature of this plant, but previous studies have determined, that H.crispa characteristics of drugs with antinociceptive and sedative-hypnotic profile. The aim of this study was to evaluate the antinociceptive effect of H. crispa, using the ethyl acetate phase from H. crispa (FAEHc), hydroalcoholic phase (FHAHc) and two flavonoids isolated from this plant (tiliroside and lespedin), as well as the possible mechanisms involved in this activity and the anti-inflammatory effect. To determine the antinociceptive mechanisms of action and the anti-inflammatory activity only FAEHc was used. The experiments conducted in mice demonstrate that FAEHc, FHAHc and flavonóides, injected via i.p., promoted significantly antinociception in the formalin test, and also showed a significantly reduction in the glutamate-induced nociception. The antinociception produced by FAEHc was significantly reversed by pretreatment of animals with caffeine, atropine or L-arginine suggesting involvement of adenosinergic, muscarinic and oxidonitrergic systems, respectively. However, FAEHc antinociceptive response was not blocked when animals were pretreated with naloxone, yohimbine and glibenclamide, indicating that FAEHc probably is not acting through these pathways. The treatment of animals with FAEHc promoted significant reduction of the paw edema induced by carrageenan in the first 48 hours of the test. Furthermore, FAEHc significantly decreased leukocyte migration, particularly the influx of neutrophils, and the levels of TNF-α and IL-1β in the model of peritonitis induced by carrageenan. Considering the results obtained in this study, is evident that FAEHc, FHAHc and flavonoids lespedin and tiliroside, chemical markers of this plant, have antinociceptive activity, but this effect cannot be attributed only to the markers, since the effect was lower than that shown by the phases and the crude extract. Also, the antinociception induced by FAEHc possibly involves activation of adenosine and muscarinic receptors as well as the nitric oxide pathway. Furthermore, FAEHc is capable of promoting a reduction of inflammation, and this effect is related to the reduction of leukocyte influx to the site of inflammation that could be attributed to inhibiting of the production of TNF-α and IL-1β
A Herissantia crispa (L.) Brizicky (Malvaceae), é composta por substâncias que apresentam atividades anti-inflamatória, antinociceptiva e antioxidante comprovadas. Há poucos relatos desta planta na literatura, mas já foi determinado, em estudos anteriores, que H. crispa apresenta características de fármacos com perfil sedativo-hipnótico e antinociceptivo. O objetivo do presente trabalho foi avaliar o efeito antinociceptivo da H. crispa, utilizando a fase acetato de etila da H. crispa (FAEHc), a fase hidroalcoólica (FHAHc) e dois flavonóides isolados desta planta (tilirosídeo e lespedina), assim como, os possíveis mecanismos de ação envolvidos nesta atividade, além do efeito anti-inflamatório. Para a determinação dos mecanismos de ação antinociceptivos e da atividade anti-inflamatória usou-se apenas a FAEHc. Os experimentos realizados em camundongos demonstram que a FAEHc, a FHAHc e os flavonóides administrados por via i.p., promoveram antinocicepção significativa no teste da formalina, porém, este efeito foi mais pronunciado com a FAEHc, que também mostrou significativa redução na nocicepção induzida pelo glutamato. A antinocicepção produzida pela FAEHc foi significativamente revertida pelo pré-tratamento dos animais com cafeína, atropina e L-arginina sugerindo envolvimento dos sistemas adenosinérgico, muscarínico e oxidonitrérgico, respectivamente. Contudo, a resposta antinociceptiva da FAEHc não foi bloqueada quando os animais foram pré-tratados com naloxona, ioimbina e glibenclamida, indicando que a FAEHc provavelmente não atua por essas vias. O tratamento dos animais com a FAEHc promoveu significante redução do edema de pata induzido pela carragenina nas primeiras 48 horas do teste. Além disso, a FAEHc diminuiu significativamente a migração leucocitária, particularmente o influxo de neutrófilos, e os níveis das citocinas TNF-α e IL-1β no modelo da peritonite induzida por carragenina. Considerando os resultados obtidos no presente trabalho, fica evidente que a FAEHc, a FHAHc e os flavonóides lespedina e tilirosídeo, marcadores químicos desta planta, apresentam atividade antinociceptiva, porém não se pode atribuir tal efeito exclusivamente aos marcadores, uma vez que o efeito apresentado foi inferior ao apresentado pelas fases e extrato bruto. E a antinocicepção induzida pela FAEHc possivelmente envolve ativação de receptores adenosinérgicos, de receptores muscarínicos e a via que envolve o óxido nítrico. Além disso, a FAEHc é capaz de promover controle da inflamação, e esse efeito está relacionado com a redução do influxo de leucócitos para o local da inflamação que pode ser atribuída a inibição da produção das citocinas TNF-α e IL-1β

APA, Harvard, Vancouver, ISO, and other styles

34

Lenz, Quéli Fernandes. "Envolvimento dos receptores CysLT1 nas crises induzidas por pentilenotetrazol em camundongos, na permeabilidade da barreira hematoencefálica e na modulação da enzima na+,k+-ATPase em hipocampo." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/3844.

Full text

Abstract:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Growing evidence has shown that leukotrienes are important contributors in the pathophysiology of several SNC inflammatory diseases where excitotoxicity is involved, including traumatic brain injury, encephalitis, Parkinson's disease, ischemia, epilepsy and neuropathic pain. However little is known about the molecular mechanism by which leukotrienes facilitate excitatory activity in the brain. Thus, in this study we investigated the effect of antagonists for cysteinyl leukotrienes receptors (CysLT) on PTZ-induced seizure in mice. Bay-u9973 (3 and 30 nmol), montelukast (0.03 and 0.3 μmol) and pranlukast (1 and 3 μmol), increased the latency to generalized seizures and decreased the mean amplitude of EEG recordings during seizures. LTD4 (0.2 and 2 pmol) reverted the anticonvulsant effect of montelukast (0.3 μmol). Montelukast (0.03 and 0.3 μmol) prevented PTZ-induced BBB disruption, an effect that was reversed by LTD4 (6 pmol). In addition, doses of LTD4 (0.2 and 2 pmol) which reversed the effect of montelukast in crisis did not alter the protective effect of montelukast on the barrier, dissociating the anticonvulsant of protective effect on BBB. The confocal microscopy analysis revealed that 1. PTZ increased the number of CD45+ and IgG cells in cerebral cortex, indicating BBB leakage with leukocyte infiltration; 2. while LTD4 (6 pmol) potentiated, montelukast decreased the effect of PTZ on leukocyte migration. Considering that increase levels of leukotrienes and decrease in Na+,K+-ATPase are common findings in several excitotoxic conditions, including epileptic seizures, we also investigated the effects of LTD4 on the activity of Na+,K+-ATPase activity in mice hippocampal slices. LTD4 10 and 100 nM decreases Na+,K+-ATPase activity alpha 2, 3 and alpha 1 subunits, respectively, in mice hippocampal slices. The inhibitory effect of LTD4 on Na+,K+-ATPase activity was not observed in hippocampal homogenates, indicating that it requires intact cells. Moreover, we showed that LTD4-induced decrease Na+,K+-ATPase activity was reversed by CysLT1R inverse agonis, montelukast (1 μM). In addition, we also showed that possibly the PKC activation pathway is involved in LTD4-induced decrease of Na+,K+-ATPase activity in mice hippocampal slices, since PKC inhibitor, GF 109203X (0,3 μM), prevent this effect. Finally, but not least important, we have demonstrated that animals injected with LTD4 (2 pmol/3 μL icv), there also occurs a decrease in Na+,K+-ATPase activity, corroborating our in vitro findings and confirming the biological importance of this work. In summary, we showed that CysLT1 receptor activation modulates hippocampal Na+,K+-ATPase activity in mice, suggesting a possible mechanism for the involvement of leukotrienes in several dosorders related with brain inflammation and hyperexcitability.
Evidências crescentes têm mostrado que os leucotrienos são importantes contribuintes na patofisiologia de diversas doenças inflamatórias do sistema nervoso central nas quais a excitotoxicidade esteja envolvida, incluindo trauma crânio-encefálico, encefalite, doença de Parkinson, isquemia, dor neuropática e epilepsia. Entretanto pouco se sabe sobre o mecanismo molecular pelo qual os leucotrienos facilitam a atividade excitatória no encéfalo. Assim, neste trabalho investigamos o efeito de antagonistas para receptores de leucotrienos cisteínicos (CysLT) sobre as convulsões induzidas por PTZ em camundongos. Bay-u9973 (3 and 30 nmol), montelucaste (0.03 and 0.3 μmol) e pranlucaste (1 and 3 μmol), aumentaram a latência para as crises e diminuíram a amplitude média do EEG durante as crises. Montelucaste (0.03 and 0.3 μmol) preveniu a ruptura da BHE induzida pelo PTZ, e o efeito foi revertido pelo LTD4 (6 pmol). Além disso, as doses de LTD4 (0.2 and 2 pmol) que reverteram o efeito do montelucaste nas crises não alteraram o efeito protetor do montelucaste sobre a barreira, dissociando o efeito anticonvulsivante do efeito protetor sobre a BHE. As análises de microscopia confocal revelaram: 1) PTZ aumentou o número de células CD45+ e IgG no córtex, evidenciando a ruptura da BHE; 2) enquanto o LTD4 (6 pmol) potencializou, o montelucaste diminuiu o efeito do PTZ sobre a migração leucocitária. Considerando que níveis aumentados de leucotrienos e diminuição na atividade da Na+,K+-ATPase são achados comuns em diversas condições excitotóxicas, incluindo crises epilépticas, também investigamos o efeito do LTD4 sobre a atividade da Na+,K+- ATPase em fatias de hipocampo de camundongos. LTD4 nas doses de 10 e 100 nM, diminuiu a atividade das subunidades alfa 2/3 e alfa 1, respectivamente. O efeito inibitório do LTD4 na atividade da Na+,K+-ATPase não foi reproduzido quando realizado com homogeneizado de hipocampo, indicando que esse efeito requer a célula intacta. A fim de nos certificarmos de que o LTD4 (10 nM) estava se ligando ao receptor CysLT1, incubamos as fatias com anticorpo anti- CysLT1, e verificamos que, na presença do anticorpo, o LTD4 perde o efeito. Além disso, observamos que a diminuição na atividade da Na+,K+-ATPase induzida pelo LTD4 foi revertida pelo montelucaste (1 μM), agonista inverso dos receptores CysLT1. Neste trabalho mostramos ainda que a ativação da PKC possivelmente esteja envolvida no efeito do LTD4 sobre a atividade da Na+,K+-ATPase em fatias de hipocampo de camundongos, uma vez que o GF 109203X (0,3 μM), inibidor da PKC, preveniu esse efeito. Por fim, mas não menos importante, também demonstramos que em animais injetados i.c.v. com LTD4 (2 pmol/3 μL, i.c.v.), também ocorre uma diminuição na atividade da Na+,K+-ATPase, corroborando com nossos achados in vitro e confirmando a importância biológica deste trabalho. Assim, este trabalho mostrou evidências do envolvimento dos receptores CysLT1 nas crises induzidas por PTZ bem como na permeabilidade da BHE, sendo a modulação da enzima Na+,K+-ATPase um possível mecanismo para a implicação dos leucotrienos em diversas doenças do SNC relacionadas com inflamação e hiperexcitabilidade.

APA, Harvard, Vancouver, ISO, and other styles

35

Ferreira, Diana Aline N?ga Morais. "Efeito anticonvulsivante de fra??es isoladas da pe?onha da formiga Dinoponera quadriceps (Formicidae: Ponerinae)." Universidade Federal do Rio Grande do Norte, 2015. http://repositorio.ufrn.br/handle/123456789/20246.

Full text

Abstract:

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-15T21:41:00Z No. of bitstreams: 1 DianaAlineNogaMoraisFerreira_DISSERT.pdf: 1601671 bytes, checksum: 0d50d44c04af4da6c6dd76cda2792325 (MD5)
Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-20T00:00:50Z (GMT) No. of bitstreams: 1 DianaAlineNogaMoraisFerreira_DISSERT.pdf: 1601671 bytes, checksum: 0d50d44c04af4da6c6dd76cda2792325 (MD5)
Made available in DSpace on 2016-04-20T00:00:50Z (GMT). No. of bitstreams: 1 DianaAlineNogaMoraisFerreira_DISSERT.pdf: 1601671 bytes, checksum: 0d50d44c04af4da6c6dd76cda2792325 (MD5) Previous issue date: 2015-05-11
A epilepsia ? uma patologia cr?nica do sistema nervoso central que afeta cerca de 65 milh?es de indiv?duos no mundo. Aproximadamente 30% desses indiv?duos desenvolvem crises convulsivas que persistem apesar do tratamento monitorado com drogas antiepil?ptica s. Assim, h? uma evidente necessidade do desenvolvimento de novos f?rmacos antiepil?pticos e as pe?onhas podem ser uma excelente fonte de modelos. Nesse contexto, enquanto j? v?rios estudos sobre pe?onhas de serpentes, escorpi?es e aranhas, pouco se sabe s obre as pe?onhas de formigas. Estudos pr?vios do nosso laborat?rio demonstraram que a pe?onha desnaturada da formiga Dinoponera quadr?ceps protegeu camundongos de crises convulsivas e morte induzidas por bicuculina (BIC). Nesse contexto, o objetivo desse t rabalho foi investigar o potencial anticonvulsivante de fra??es isoladas da pe?onha de D. quadr?ceps em crises convulsivas induzidas pela BIC, bem como uma an?lise dos efeitos dessas fra??es no comportamento natural dos camundongos no campo aberto. Os anim ais foram divididos em grupos, os quais receberam inje??es (1 mg/ml i.c.v.) de seis fra??es distintas e tiveram seu comportamento geral observado no campo aberto durante 3 0 min. No segundo experimento, o s animais receberam as mesmas fra??es 20 min antes da administra??o de bicuculina (10 mg/ml). Em seguida, foi analisado o comportamento motor convulsivo desses animais durante 30 minutos no campo aberto. No primeiro experimento, n?o foram observadas altera??es comportamentais. J? no segundo experimento, a ad ministra??o pr?via de DqTx1, DqTx3, DqTx4 e DqTx6 aumentou a lat?ncia para o desenvolvimento de crises t?nico - cl?nicas. Al?m disso, todas as fra??es, exceto DqTx5, aumentaram a lat?ncia para a morte dos animais. Ainda, os melhores resultados foram obtidos com a fra??o DqTx6, que protegeu 62,5% dos animais testados contra o desenvolvimento de crises t?nico - cl?nicas e 100% dos animais contra a morte.

APA, Harvard, Vancouver, ISO, and other styles

36

Teixeira, Bianca Luise. "Efeitos do fator de crescimento epidermal (EGF) na potencialidade e diferenciação das células da crista neural de aves." Florianópolis, SC, 2011. http://repositorio.ufsc.br/xmlui/handle/123456789/95368.

Full text

Abstract:

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e do Desenvolvimento, Florianópolis, 2011
Made available in DSpace on 2012-10-26T00:43:50Z (GMT). No. of bitstreams: 1 296293.pdf: 595442 bytes, checksum: 4a44716096b914945e724217369d1213 (MD5)
A crista neural (CN) é uma população de células originadas das margens dorsais do tubo neural durante o desenvolvimento de vertebrados. Essas células possuem um alto potencial migratório e dão origem a múltiplos fenótipos como neurônios, células gliais, melanócitos e a diversos derivados mesenquimais. Sabe-se que essa diversificação de fenótipos é espacialmente e temporalmente influenciada por fatores do microambiente. Vários fatores de crescimento, incluindo o fator de crescimento epidermal (EGF), têm sido identificados como sendo capazes de direcionar a diferenciação de progenitores multipotentes da CN para tipos celulares específicos. Segundo Garcez e colaboradores (2009), o EGF é capaz de influenciar in vitro a diferenciação melanocítica das células da CN, aumentando o número de células pigmentadas em cultura. No presente trabalho investigamos os efeitos do EGF na potencialidade e diferenciação das células da CN de codornas (Coturnix coturnix japonica). Para isso culturas de massa e clonais de CN foram tratadas com EGF (10ng/mL). Nas células da CN truncal (CNT) os tratamentos foram realizados nas primeiras 20h, fase de migração das células a partir do tubo neural. Já para as células da CN cefálica (CNC) os tratamentos foram realizados após o período de migração, durante toda a cultura secundária. As células foram então fixadas e analisadas quanto à expressão do receptor de EGF (EGFR) e dos diferentes fenótipos celulares derivados da CN. Nossos resultados demonstram a expressão do EGFR pelas células da CNT 20h após o início da migração a partir do tubo neural, na cultura primária. O possível efeito do EGF na diferenciação condrocítica foi avaliado na CNC por apresentar o potencial mesectodermal. Em nossos resultados observamos frequência, número e tamanho dos nódulos de cartilagem equivalentes entre as condições controle e após tratamento com EGF, sugerindo que o EGF não influencia a diferenciação da CN para o fenótipo condrocítico. Para avaliar um possível efeito do EGF na potencialidade dos progenitores da CN, realizamos ensaios clonais, onde as células são plaqueadas individualmente sob controle microscópico. Identificamos progenitores comprometidos com as linhagens neuronal, glial, melanocítica ou muscular lisa, assim como progenitores bi, tri e tetrapotentes para diversas combinações destes fenótipos celulares. As proporções dos progenitores assim como a eficiência clonal (cerca de 60%) foram equivalentes nas duas condições experimentais, demonstrando que o EGF não interfere na proliferação nem na potencialidade dos progenitores da CN. Em trabalho anterior verificamos que o EGF promove aumento do número de melanócitos diferenciados identificados pela presença de melanina. Investigamos, então, se EGF influencia na diferenciação final dos melanócitos, avaliando a relação entre a expressão do marcador da linhagem melanocítica (melanocyte earlier marker, MelEM), que identifica tanto melanoblastos quanto melanócitos diferenciados, e a melanina. Observamos na condição controle que cerca de 20% das células da CN positivas para MelEM também apresentavam melanina, enquanto que após o tratamento com EGF essa proporção foi de 60%, correspondendo a um aumento de 3X. Esses resultados indicam que o EGF deva estar atuando sobre a etapa final do processo de diferenciação dos melanócitos, possivelmente envolvendo o processo da síntese de melanina. Entender o papel do EGF sobre a diferenciação melanocítica certamente contribuirá para avanços nos estudos de patologias que envolvam alterações no padrão de pigmentação, e as suas consequências, em organismos vertebrados.

APA, Harvard, Vancouver, ISO, and other styles

37

L?pez, Christian Camilo Garc?a. "Livre-arb?trio? Fatores psiconeuroend?crinos envolvidos no processo de tomada de decis?o sob risco em homens adultos jovens." PROGRAMA DE P?S-GRADUA??O EM PSICOBIOLOGIA, 2017. https://repositorio.ufrn.br/jspui/handle/123456789/24442.

Full text

Abstract:

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-04T20:41:47Z No. of bitstreams: 1 ChristianCamiloGarciaLopez_DISSERT.pdf: 2196830 bytes, checksum: 3aec0c3604ab6bb915398d3380ba6a61 (MD5)
Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-07T19:26:20Z (GMT) No. of bitstreams: 1 ChristianCamiloGarciaLopez_DISSERT.pdf: 2196830 bytes, checksum: 3aec0c3604ab6bb915398d3380ba6a61 (MD5)
Made available in DSpace on 2017-12-07T19:26:20Z (GMT). No. of bitstreams: 1 ChristianCamiloGarciaLopez_DISSERT.pdf: 2196830 bytes, checksum: 3aec0c3604ab6bb915398d3380ba6a61 (MD5) Previous issue date: 2017-06-05
O comportamento de risco est? sob influ?ncia de fatores neuropsicol?gicos, neuroend?crinos, sociais e individuais. O perfil hormonal, estados de humor, bem como status de relacionamento rom?ntico, sexo e idade est?o todos implicados neste comportamento. Embora ainda n?o haja um consenso claro sobre o quanto esses fatores modulam o processo de tomada de decis?o sob risco. O presente estudo avaliou o efeito de estados psicol?gicos, o envolvimento em um relacionamento rom?ntico, e testosterona (pr?-natal e ativa??o) e cortisol sobre o comportamento de risco; bem como a reatividade desses horm?nios no desempenho de uma tarefa de risco. Estudantes universit?rios entre os 21 e 30 anos (n = 49) participaram da investiga??o. O comportamento em rela??o ao risco foi medido utilizando uma escala de propens?o ao risco (EPR) e uma tarefa de tomada de decis?o sob risco, Columbia Card Task (CCT). Um efeito negativo foi encontrado entre uma baixa propor??o 2D:4D e a atitude em rela??o ao risco na dimens?o sa?de/seguran?a no EPR, quando a testosterona basal e o cortisol foram baixos ou altos. Enquanto, os participantes com alta propor??o 2D:4D, mostram um maior comportamento de risco no CCT, associado com altos n?veis de testosterona basal e baixos do cortisol. Um aumento na testosterona foi relacionado com um melhor desempenho, e menos tempo gasto no CCT. Estar envolvido em um relacionamento rom?ntico foi associado a uma maior avers?o ao risco no CCT. Os participantes com maior pontua??o para depress?o e ansiedade tinham uma atitude mais elevada em rela??o ao risco no CCT. Estes resultados sugerem que uma elevada exposi??o pr?-natal ? testosterona fortalece a atitude em rela??o ao risco, diminuindo o efeito activacional da testosterona e do cortisol, bem como a plasticidade comportamental, sugerindo que a testosterona activacional n?o ? cr?tica para a express?o deste tra?o comportamental. Por outro lado, n?veis mais baixos de testosterona pr?-natal permitem maiores efeitos da ativa??o hormonal e plasticidade comportamental dependendo do contexto. A reatividade da testosterona pode promover uma avers?o ao risco para obter um resultado mais favor?vel. Nossas descobertas suportam as descobertas de que estar envolvido em um relacionamento rom?ntico, est? relacionado com um maior risco assumindo comportamento em favor da sua aptid?o evolutiva. Tamb?m ? proposto que, em contextos de alto risco, os participantes com caracter?sticas mais depressivas e ansiosas podem levar a comportamentos mais arriscados.
Risk-taking behavior is influenced by neuropsychological, neuroendocrine, social and individual factors. However, there is still no clear consensus on the extent to which these factors modulate decision-making under risk. The present study evaluated the effect of psychological states, romantic partnership, testosterone (prenatal and activational) and cortisol on risk-taking behavior, as well as the reactivity of these hormones on the performance of a risk-taking task. University students aged between 21 and 30 years (n = 49) participated in the investigation. The behavior towards risk was measured using a self-reported risk propensity scale (RPS) and for the decision-making task under risk, the Columbia Card Task (CCT). A negative effect was found between a low 2D:4D ratio and the attitude towards risk in the health/safety dimension of the RPS, when basal testosterone and cortisol were either low or high. On the other hand participants with a high 2D:4D ratio show greater risk- taking behavior in the CCT, associated with high basal testosterone and low cortisol. An increase in testosterone was related to better performance and less time spent on the CCT. Being involved in a romantic relationship was associated with higher aversion to risk on the CCT. Participants with higher depression and anxiety scores had a greater attitude towards risk on the CCT. These results suggest that high prenatal testosterone exposure strengthens the attitude toward risk, decreasing the activational effect of testosterone and cortisol, as well as behavioral plasticity, suggesting that activational testosterone is not critical for the expression of this behavioral trait. However, lower levels of prenatal testosterone allow greater hormonal activational effects and behavioral plasticity depending on the context. Testosterone reactivity might promote aversion to risk to produce a more favorable outcome. Our findings show that being involved in a romantic relationship is related to being more prone to risk taking behavior in favor of evolutionary fitness. It is also proposed that in situations high-risk participants with more severe depressive and anxiety traits may lead to an increase in risky behavior.
2018-10-01

APA, Harvard, Vancouver, ISO, and other styles

38

DI, LILLO ALESSIA. "CAN A PRECISELY-POSITIONED DNA DOUBLE-STRAND BREAK (DSB) ACTIVATE GENE EXPRESSION?" Doctoral thesis, Università degli Studi di Milano, 2021. http://hdl.handle.net/2434/884393.

Full text

Abstract:

Our group previously demonstrated that when a DNA double-strand break (DSB) occurs, RNA polymerase II (RNAPII) is recruited to the exposed DNA ends and allows the by-directional synthesis of transcripts derived from exposed DNA ends that we called damage-induced long non-coding RNAs (dilncRNAs). Recently we reported that a DSB also recruits the full transcriptional machinery, in particular the preinitiation complex (PIC), just as commonly recruited at canonical RNA polymerase II-driven transcriptional promoters. This, blurs the distinction between a DSB and a transcriptional promoter. dilncRNAs were defined as non-coding as most of our genome is not coding for polypeptides and thus, DSB will most often transcribe non coding regions of DNA. However, what would be the consequences of a DSB occurring upstream of a gene unit, lacking a promoter but carrying all other features of a coding sequence, such as an open reading frame (ORF) and a poly(A) signal? Would the ensuing dilncRNA actually be a coding transcript? In other words: can a DSB trigger the synthesis of a protein? Therefore, the aim of this project is to test if a DSB appropriately positioned at the transcriptional start site (TSS) of an otherwise silent gene may assemble a functional promoter, triggering RNA synthesis which leads to protein expression. I have carried out such studies in artificial cell systems in which I have engineered promoter-less reporter genes. In addition, I have tested whether a DSB is sufficient to re-express a candidate tumour suppressor gene, HIC-1 (hyper-methylated in cancer 1), that is commonly silenced by promoter methylation. In more in detail, I tested my working hypothesis in three different systems. As a proof of concept, I first used two reporter gene-based systems: a stable clonal cell line of HeLa cells bearing an integrated lentiviral construct encoding for an enhanced green fluorescent protein (EGFP) ORF lacking its transcriptional promoter and enhancer region, and an immortalized mouse embryonic fibroblast (MEF) cell line carrying a promoter-less enhanced yellow fluorescent protein (EYFP) integrated by homologous recombination in the locus Rosa26 of the mouse genome. To induce sites-specific DSBs, I employed the CRISPR/Cas9 technology. Single guide RNAs targeting the GFP or EYFP transcriptional start site (TSS) were cloned in a lentiviral vector and cells were transduced with such a vector expressing them together with Cas9 to test the impact of DSB induction on the expression of the reporter gene. The second system takes advantage of MDA MB 231, a human breast cancer cell line, in which HIC1 endogenous gene is actively silenced by promoter DNA methylation. The goal, here, is to infect these cells with a CRISPR/Cas9 lentiviral vector to induce a DSB at the TSS of HIC1 gene and monitor the synthesis of a mature messenger RNA. These experiments suggested that a DSB, appropriately positioned at a gene TSS, triggers the transcription of RNAs that are polyadenylated, exported in the cytoplasm and translated into a functional protein. This study could be relevant to identify a novel mechanism of transcriptional regulation based on DSB at promoters. This approach could also be used to activate gene expression in genetic disease settings, or to activate the expression of tumor suppressor genes that are silenced in tumors.

APA, Harvard, Vancouver, ISO, and other styles

39

Licon, Ana Laura. "Spiderworms: Using Silkworms as Hosts to Produce a Hybrid Silkworm-Spider Silk Fiber." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7591.

Full text

Abstract:

Spider silk has received significant attention due to its fascinating mechanical properties. Given the solitary and cannibalistic behavior of spiders, spider silk farming is impractical. Unlike spiders, silkworms are capable of producing large quantities of a fibrous product in a manner mimetic to spiders, and there already exists an industry to process cocoons into threads and textiles for many applications. The combination of silk farming (sericulture), a millennia old practice, and modern advancements in genetic engineering has given rise to an innovative biomaterial inspired by nature; transgenic silkworm silk. This project focuses on the creation of chimeric silkworm-spider silk fibers through the genetic modification of silkworms. Advanced genetic engineering techniques were used to introduce the minor ampullate spider silk (MiSp) genes into the silkworm genome. A subset of these transgenic silkworms was cross-bred with other transgenic silkworms containing the same spider silk gene in a different section of the silkworm genome to create hybrid, dual-transgenic silkworms. The transgenic silk samples showed increased mechanical properties compared to native silkworm fibers, with the strongest fibers approaching or surpassing the mechanical properties of native spider silk. The transgenic silk retained the elasticity of the native silkworm silk and gained the strength of the spider silk. Ultimately, genetic engineering opens the door to mass produce synthetic spider silk in an established organism and industry, and the results of this project demonstrate that the properties of silkworm silk can be predictably altered through this technology.

APA, Harvard, Vancouver, ISO, and other styles

40

Janin, Grajcarek. "Genome-wide microhomologies enable precise template-free editing of biologically relevant deletion mutations." Kyoto University, 2020. http://hdl.handle.net/2433/253215.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

TAVELLA, SARA. "WEAPONIZING CRISPR/CAS9." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/908993.

Full text

Abstract:

One of the major limits of current therapies against cancer and viral infections is the nonspecific toxicity that they often cause on healthy tissues because of their impact on important cellular mechanisms shared, to different extents, between diseased and healthy cells. For this reason, there is an unmet need for more specific and more effective therapies. Wherefore, the aim of my project is the development of a novel strategy, with potential for therapy, that allows the induction of sequence-specific DNA lesions (DNA double-strand break, DSB), by the use of the CRISPR/Cas9 system targeting a genome sequence abnormality in diseased cells, while sparing normal cells. Potential applications of this approach can be cancer cells carrying genomic mutations or chromosomal rearrangements and infected cells carrying an integrated proviral genome. Importantly, whether the aberrant genome sequences are expressed or not is irrelevant for the efficacy of this approach. As a proof of principle, I generated, in two parallel cell systems, an isogenic pair of cell lines with a healthy and a diseased counterpart. The “diseased” target sequence is an integrated proviral genome. To generate them, I infected HeLa and RKO cells with a lentiviral vector containing the sequence of the green fluorescent protein (GFP). I then treated these two cell systems with the purpose of inducing a DSB by retroviral transduction of the Cas9 endonuclease and its RNA guide targeting the integrated GFP sequences. As a negative control, I treated these cell lines in parallel with a Cas9 carrying a scramble guide that does not recognize any sequence in the human genome. Upon these treatments, I observed a preferential reduction of proliferation and an increased mortality in cells bearing the target sequence and transduced with the targeting RNA guide compared to cells without the target sequence or transduced with the scramble guide. I also observed that Cas9-mediated DNA damage is associated with the formation of micronuclei which often stain positive for cGAS and activate an inflammatory response. These results suggest the possibility to “weaponize” the CRISPR/Cas9 system for the elimination of cells with an aberrant genome. However, cells can survive DNA damage insults by repairing them. In order to address this mechanism of “resistance” to the treatment, I investigated if the generation of a sequencespecific DSB can be combined with the inhibition of its repair. Indeed, Cas9-induced DNA damage and inhibition of DNA repair by non-homologous end-joining (NHEJ) by the use of a pharmacological inhibitor of the DNA-dependent protein kinase (DNA-PK), a DNA repair factor involved in NHEJ, further kill target cells. However, DNA-PK inhibition lacks sequence specificity in its activity, thus impacting on the repair of endogenous DNA damage too. For this reason, a sequence-specific DSB repair inhibitor would be desirable. Our group has previously demonstrated that DSBs trigger the recruitment of RNA polymerase II that generates damage-induced long non-coding RNAs (dilncRNAs) at DSB. DilncRNAs are the precursors of small non-coding RNAs called DNA damage response RNAs (DDRNAs) and the interaction between dilncRNAs and DDRNAs is necessary for the recruitment of the proteins involved in DDR, including DNA repair. Noteworthy, antisense oligonucleotides (ASO) against these damage-induced RNA species impair their functions and inhibit the assembly of DDR factors in the form of foci and thus they are effective sequence-specific DNA repair inhibitors. In cells treated with Cas9, I observed a reduction in DDR foci, compared to controls, upon treatment with sequence-specific ASO, confirming the efficacy of ASO also in my experimental system.

APA, Harvard, Vancouver, ISO, and other styles

42

Soardi, Michela. "Generation of novel zebrafish models of sarcoglycanopathy." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3426362.

Full text

Abstract:

Sarcoglycanopathy is the collective name of four rare autosomal recessive diseases belonging to the limb-girdle muscular dystrophies type 2 (LGMD2C-F), due to mutations in SGCG, SGCA, SGCB, SGCD genes coding for γ-, α-, β- and δ- sarcoglycan (SG) respectively. SGs form a tetrameric sub-complex on the sarcolemma, closely linked to the dystrophin associated protein complex (DAPC) and play an essential role in assuring membrane integrity during muscle contraction (Bushby, 2009). Mutations in each SG gene cause the loss/reduction of the mutated protein as well as of the wild type (WT) partners with an alteration of the DAPC structural properties and an increased fragility of the sarcolemma. Most of the known disease-causing mutations are missense mutations that results in a folding defective SG, recognized and prematurely degraded by the endoplasmic reticulum associated degradation (ERAD) through the proteasome (Gastaldello et al., 2008). The knowledge of the pathological mechanism opens new avenues to two small molecules-based pharmacological interventions. By inhibiting the mutant degradation or assisting its folding the whole SG complex is recovered on the membrane, suggesting that many mutants are still functional although structurally defective (Bianchini et al., 2014; Carotti et al., 2018). Now for the subsequent preclinical test, these in vitro data need to be validated in vivo. To accomplish this task, in the absence of suitable rodent models, zebrafish models carrying missense mutations in SGs are needed to mimic the human condition. Among SGs, β- and δ-SG are the most conserved, therefore they were chosen to mimic sarcoglycanopathy in zebrafish. The nearly identical muscle structure with the human one, the ease to set up functional and drug screening test, make this vertebrate an ideal choice for our task. The proof of concept of the suitability of the model came from the knock-down of δ-SG by using the morpholino technique. Morphants showed altered morphology and compromised swimming ability. On these promising data, we decided to generate novel zebrafish lines in which β- or δ-SG genes are modified by using the CRISPR/Cas9 technique. β- and δ-SG Knock-out (KO) animals have been generated and characterized. The absence of the protein led to the progressive alteration of the muscle structure and impairment of the swimming ability. Presently, KO animals are used as the background for the injection of the WT or mutated sequence of the corresponding SG, of human or zebrafish origin. The injection of the WT sequence should allow the rescue of the phenotype, whereas that of the mutated forms will permit to evaluate the ability of the zebrafish ERAD to recognize and degrade a folding defective SG. This data will be of utmost importance to verify the suitability of zebrafish in mimicking those forms of sarcoglycanopathy due to missense mutations. β-SGT145R/T145R and δ-SGE264K/E264K Knock-in (KI) are presently under production. Since the efficacy of the homologoy direct repair is very low, much effort has been devoted to set up a selective procedure to screen the positive fish. Actually, the screening of the somatic recombinants for the introduction of the T145R mutation in z-sgcb gene was positive. We are presently waiting for the sexual maturation of the F0 population to perform the outcross with WT in order to identify the founder animals, in which the recombination occurred in the germline. If successfully modelling the sarcoglycanopathy conditions, these KI lines will represent a fundamental tool for testing the proposed pharmacological approach and will be a valuable boost for both basic and translational research.
Le sarcoglicanopatie sono quattro rare patologie autosomiche recessive appartenenti alla famiglia delle distrofie muscolari di tipo 2 (LGMD2C-F). Esse sono causate da mutazioni nei geni SGCG, SGCA, SGCB, SGCD codificanti rispettivamente per γ-, α-, β- e δ- sarcoglicano (SG). I SG formano un complesso tetramerico nel sarcolemma, connesso a quello delle glicoproteine associate alla distrofina (DAPC), essenziale per garantire l'integrità della membrana durante la contrazione muscolare (Bushby, 2009). Mutazioni dei SG causano la perdita/riduzione della proteina mutata e dei partner wild type (WT), alterando le proprietà strutturali del DAPC e aumentando la fragilità del sarcolemma. La maggior parte delle mutazioni sono di tipo missenso e, causando un problema nel folding, portano alla prematura degradazione della proteina mutata effettuata dalla via ERAD (degradazione associata al reticolo endoplasmatico) attraverso il proteasoma (Gastaldello et al., 2008; Bartoli et al., 2008). La conoscenza del meccanismo patologico ha aperto nuove strade a due possibili interventi farmacologici: inibendo la degradazione o assistendo il processo di folding dei mutanti, il complesso dei SG è recuperato riducendo così la fragilità della membrana (Bianchini et al., 2014; Carotti et al., 2018). Questi dati prodotti in vitro suggeriscono che molti mutanti sono ancora funzionali, sebbene strutturalmente difettosi. Tuttavia, per la messa a punto di un approccio terapeutico, questi dati necessitano di una validazione in vivo, attraverso modelli animali per mimare la malattia umana e recanti quindi mutazioni missenso nei SG. In assenza di modelli murini, un’alternativa promettente per lo studio di molte malattie, fra cui i disturbi muscolari, è rappresentata dallo zebrafish (D.rerio). Tra gli ortologhi dei SG umani, β- e δ-SG sono i più conservati e quindi sono stati scelti per produrre linee knock-out (KO) e knock-in (KI). La bontà dell’uso di questo vertebrato nel mimare la sarcoglicanopatia nasce da uno studio preliminare di Knock-Down con morfolino contro il δ-SG. I morfanti ottenuti hanno mostrato: alterazioni morfologiche, danni alla struttura muscolare e compromissione delle capacità motorie. Grazie a queste premesse, il sistema CRISPR/Cas9 è stato usato per generare modelli KO di β- e δ-SG. In entrambi i casi, l'assenza della proteina provoca la progressiva alterazione della struttura muscolare e delle capacità motorie. Attualmente stiamo usando i KO come background per l'iniezione della sequenza WT o mutata dei SG, sia di origine umana sia di zebrafish. La prima dovrebbe consentire il recupero del fenotipo, mentre quella delle forme mutate permetterà di valutare la capacità dello zebrafish di riconoscerle e degradarle. Questi esperimenti sono della massima importanza per verificare l'idoneità dello zebrafish nel mimare le forme di sarcoglicanopatia causate da mutazioni missenso. La generazione di due modelli KI in zebrafish, β-SGT145R/T145R e δ-SGE264K/E264K, prevede l’attivazione della via di riparazione HDR (riparazione omologa diretta). Poiché l'efficienza della ricombinazione omologa è molto bassa, è necessario l’uso di un metodo altamente selettivo per identificare i pesci positivi alla voluta mutazione. Lo screening delle mutazioni somatiche per l'introduzione della mutazione T145R nel gene z-sgcb è stato positivo. Attualmente stiamo aspettando la maturazione sessuale della popolazione F0 per identificare quei pesci in cui ricombinazione sia avvenuta nella linea germinale. Se le linee KI, una volta caratterizzate, mimeranno la patologia umana, rappresenteranno uno strumento fondamentale per testare l'approccio farmacologico proposto in vitro, e costituiranno un valido stimolo per la ricerca di base e traslazionale.

APA, Harvard, Vancouver, ISO, and other styles

43

Stringa, Blerta. "The effect of germline variants on the genesis of early somatic events in cancer explored via Cas9 genome editing." Doctoral thesis, Università degli studi di Trento, 2019. http://hdl.handle.net/11572/242372.

Full text

Abstract:

Although the understanding of genetic predisposition to prostate cancer (PCa) has been improved through genome-wide association studies (GWAS), little is known about the biological implication of germline variants residing in coding or non-coding regions in cancer development and progression. Our hypothesis is that inherited variants may predispose to specific early recurrent genomic events observed in PCa adenocarcinomas, possibly in the context of variable androgen receptor (AR) signaling that changes during a man’s lifetime. Recent in silico analysis by our group on potential association between germline variants and PCa specific somatic lesions identified a non-coding polymorphic regulatory element at the 7p14.3 locus associated with DNA repair and hormone regulated transcript levels and with an early recurrent prostate cancer specific somatic mutation in the Speckle-Type POZ protein (SPOP) gene (OR=5.54, P=1.22e-08) in human prostate tissue data. In order to functionally characterize the polymorphic 7p14.3 locus (rs1376350, single nucleotide polymorphism, G>A), we set up to establish isogenic cell lines harboring the minor allele by using the CRISPR/Cas9 system. In parallel, CRISPR/Cas9 system was used to knock out different portion of the region encompassing the 7p14.3 variant and to eliminate transcription factors (TFs) binding sites that were identified from previous in silico analysis (i.e. AR and CCAAT/Enhancer Binding Protein (C/EBP) beta (CEBPβ)). The transcriptomes of edited pools and edited single clones from macrodeletion (731 bp), microdeletion (50 bp) and alterations of TFs binding sites were analyzed and compared to the transcriptomes of isogenic cells heterozygous (A/G) and homozygous (A/A) for the minor allele A of the risk variant rs1376350 (with or without AR overexpression). These data identified a set of genes scattered throughout the genome with the same pattern of deregulation suggesting the implication of the variant on the regulation of genes residing in different chromosomes. Additionally, ChIP-qPCR experiments for histone modification supported the identification of the 7p14.3 locus with enhancer activity. Furthermore, ChIP-qPCR of histone mark associated with transcriptional activation or repression in isogenic cells harboring the minor allele A upon AR overexpression showed that the activity of the locus is higher for the minor allele A compared to G, independently from AR activation. Despite the limitations of our model and the current lack of validation in other cells, we confirmed that some of the differentially expressed genes that emerged from the comparative analysis of edited cells are deregulated in human normal and tumor prostate samples as well. This work is a proof of concept of germline predisposition to molecularly distinct cancer subclasses and has the potential to nominate new mechanisms of cancer development. Future work aims to elucidate the mechanisms implicated in the deregulation of the transcriptome by combining the information obtained until now with potential new players that we expect to identify by Mass Spectrometry experiments. To clarify the link between the 7p14.3 variant and the somatic mutations in SPOP, we plan to express mutant SPOP in isogenic cells harboring the minor allele and to asses DNA damage response upon overexpression or silencing of TFs binding at and around the rs1376350 variant. My work is an example of how the CRISPR/Cas9 system can be used to develop a technical framework with convergent approaches to functionally characterize polymorphic regulatory regions including but not limited to the establishment of isogenic cells upon single nucleotide editing.

APA, Harvard, Vancouver, ISO, and other styles

44

Stringa, Blerta. "The effect of germline variants on the genesis of early somatic events in cancer explored via Cas9 genome editing." Doctoral thesis, Università degli studi di Trento, 2019. http://hdl.handle.net/11572/242372.

Full text

Abstract:

Although the understanding of genetic predisposition to prostate cancer (PCa) has been improved through genome-wide association studies (GWAS), little is known about the biological implication of germline variants residing in coding or non-coding regions in cancer development and progression. Our hypothesis is that inherited variants may predispose to specific early recurrent genomic events observed in PCa adenocarcinomas, possibly in the context of variable androgen receptor (AR) signaling that changes during a man’s lifetime. Recent in silico analysis by our group on potential association between germline variants and PCa specific somatic lesions identified a non-coding polymorphic regulatory element at the 7p14.3 locus associated with DNA repair and hormone regulated transcript levels and with an early recurrent prostate cancer specific somatic mutation in the Speckle-Type POZ protein (SPOP) gene (OR=5.54, P=1.22e-08) in human prostate tissue data. In order to functionally characterize the polymorphic 7p14.3 locus (rs1376350, single nucleotide polymorphism, G>A), we set up to establish isogenic cell lines harboring the minor allele by using the CRISPR/Cas9 system. In parallel, CRISPR/Cas9 system was used to knock out different portion of the region encompassing the 7p14.3 variant and to eliminate transcription factors (TFs) binding sites that were identified from previous in silico analysis (i.e. AR and CCAAT/Enhancer Binding Protein (C/EBP) beta (CEBPβ)). The transcriptomes of edited pools and edited single clones from macrodeletion (731 bp), microdeletion (50 bp) and alterations of TFs binding sites were analyzed and compared to the transcriptomes of isogenic cells heterozygous (A/G) and homozygous (A/A) for the minor allele A of the risk variant rs1376350 (with or without AR overexpression). These data identified a set of genes scattered throughout the genome with the same pattern of deregulation suggesting the implication of the variant on the regulation of genes residing in different chromosomes. Additionally, ChIP-qPCR experiments for histone modification supported the identification of the 7p14.3 locus with enhancer activity. Furthermore, ChIP-qPCR of histone mark associated with transcriptional activation or repression in isogenic cells harboring the minor allele A upon AR overexpression showed that the activity of the locus is higher for the minor allele A compared to G, independently from AR activation. Despite the limitations of our model and the current lack of validation in other cells, we confirmed that some of the differentially expressed genes that emerged from the comparative analysis of edited cells are deregulated in human normal and tumor prostate samples as well. This work is a proof of concept of germline predisposition to molecularly distinct cancer subclasses and has the potential to nominate new mechanisms of cancer development. Future work aims to elucidate the mechanisms implicated in the deregulation of the transcriptome by combining the information obtained until now with potential new players that we expect to identify by Mass Spectrometry experiments. To clarify the link between the 7p14.3 variant and the somatic mutations in SPOP, we plan to express mutant SPOP in isogenic cells harboring the minor allele and to asses DNA damage response upon overexpression or silencing of TFs binding at and around the rs1376350 variant. My work is an example of how the CRISPR/Cas9 system can be used to develop a technical framework with convergent approaches to functionally characterize polymorphic regulatory regions including but not limited to the establishment of isogenic cells upon single nucleotide editing.

APA, Harvard, Vancouver, ISO, and other styles

45

Stens, Cassandra, Isabella Enoksson, and Sara Berggren. "The CRISPR-Cas system." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-171997.

Full text

Abstract:

Derived from and inspired by the adaptive immune system of bacteria, CRISPR has gone from basic biology knowledge to a revolutionizing biotechnological tool, applicable in many research areas such as medicine, industry and agriculture. The full mechanism of CRISPR-Cas9 was first published in 2012 and various CRISPR-Cas systems have already passed the first stages of clinical trials as new gene therapies. The immense research has resulted in continuously growing knowledge of CRISPR systems and the technique seems to have the potential to greatly impact all life on our planet. Therefore, this literature study aims to thoroughly describe the CRISPR-Cas system, and further suggest an undergraduate laboratory exercise involving gene editing with the CRISPR-Cas9 tool. In this paper, we describe the fundamental technical background of the CRISPR-Cas system, especially emphasizing the most studied CRISPR-Cas9 system, its development and applications areas, as well as highlighting its current limitations and ethical concerns. The history of genetic engineering and the discovery of the CRISPR system is also described, along with a comparison with other established gene editing techniques. This study concludes that a deeper knowledge about CRISPR is important and required since the technique is applicable in many research areas. A laboratory exercise will not only inspire but also provide extended theoretical and practical knowledge for undergraduate students.

APA, Harvard, Vancouver, ISO, and other styles

46

RUBOLINO, CARMELA. "NEW FINDINGS INTO TARGET-DIRECTED MICRORNA DEGRADATION MECHANISM." Doctoral thesis, Università degli Studi di Milano, 2022. https://hdl.handle.net/2434/945228.

Full text

Abstract:

MiRNAs are a class of small non-coding RNAs that function in post-transcriptional gene silencing by interacting with target RNAs. A novel mechanism in control of miRNA levels, called Target-Directed miRNA degradation (TDMD), has been described, which involves specific transcripts able to interact with miRNAs and induce miRNA degradation. We showed that an endogenous RNA transcript, Serpine1, uses TDMD to control levels and activity of miR:30b/c in murine fibroblasts. It is unknown how many other TDMD transcripts exist; therefore, we developed TDMDfinder, a computational pipeline and free webtool, that identifies “high confidence” TDMD interactions in the Human and Mouse transcriptomes by combining sequence alignment and feature selection approaches. Our predictions suggested that TDMD is widespread, with potentially every miRNA controlled by endogenous targets. We experimentally tested 37 TDMDfinder predictions, of which 17 showed TDMD effects as measured by RT-qPCR and small RNA sequencing, linking the miR-17, miR-19, miR-30, miR-221, miR-26 and miR-23 families to novel endogenous TDMD triggers. Computational analyses performed using the multiomic TCGA platform substantiated the possible involvement of many TDMD transcripts in human cancer and highlighted 36 highly significant pan-cancer interactions, suggesting TDMD as a new potential oncogenic mechanism. Focusing on the SERPINE1:miR30b/c pair as a model, we applied molecular and genetic approaches to manipulate TDMD and investigate the effects afforded by miRNA degradation in breast cancer. Our results suggested that TDMD is used by breast cancer cells to keep low miRNA activity and provide a selective advantage in various cancer phenotypes. In order to identify all TDMD-regulated miRNAs in breast cancer, we inhibited the TDMD mechanism by knocking down a critical player of the pathway, the ZSWIM8 culling-RING ubiquitin ligase substrate adapter. We repressed ZSWIM8 by CRISPR interference in a set of 8 different breast cancer (BC) cell lines, representing the entire spectrum of BC subtypes. Our analyses showed that loss of ZSWIM8 caused significantly increased accumulation of 31 miRNAs, without any evidence of transcriptional regulation, thus expanding the role of endogenous TDMD in sculpting miRNA levels. Finally, to identify the TDMD triggers in BC, we designed a strategy based on the combined use of TDMDfinder predictions and experimental CRISPR-based tools. We performed a proof-of-concept validation of the approach by identifying the endogenous TDMD trigger (NREP) for miR-29b-3p in SUM159PT and BT549, proving that this can be an effective strategy to quickly identify TDMD substrates and triggers.

APA, Harvard, Vancouver, ISO, and other styles

47

RICCI, RAFFAELE. "Activatory CRISPR/dCa9 as a therapeutic strategy in Dravet Syndrome." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2022. http://hdl.handle.net/10281/365223.

Full text

Abstract:

La sindrome di Dravet (SD) è una encefalopatia epilettica dello sviluppo, caratterizzata da crisi convulsive farmaco-resistenti e un alto rischio di morte improvvisa durante le crisi. L'80% dei pazienti presenta mutazioni eterozigoti sul gene SCN1A, con conseguente perdita della sua funzionalità, indicando che un meccanismo di aploinsufficienza sia alla base dell'insorgenza della patologia. SCN1A codifica per la subunità alfa del canale del sodio voltaggio-dipendente Nav1.1, essenziale per la generazione del potenziale d'azione (PA) negli interneuroni gabaergici (ING).Analisi di modelli animali hanno evidenziato che lo sviluppo delle crisi è dovuto a una riduzione dell'eccitabilità degli ING, in particolare dei sottotipi esprimenti i markers parvalbumina (PV), somatostatina (SST) e peptide intestinale vasoattivo (VIP), con conseguente sovraeccitazione della rete neuronale. Altri lavori hanno anche riportato ipereccitabilità nei neuroni eccitatori (NE) durante tutte le fasi della patologia o solo nella fase pre-epilettica, suggerendo il coinvolgimento di questo sottotipo neuronale nella SD.Le mutazioni eterozigoti con perdita della funzionalità conducono ad una riduzione quantitativa dell'espressione genica del 50%. Per questo motivo, abbiamo deciso di impiegare una nuova strategia basata sull'attivatore trascrizionale CRISPR-dCas9 per aumentare specificamente i livelli della proteina Nav1.1 stimolando la trascrizione del gene Scn1a.Abbiamo quindi dimostrato l'efficienza di questo sistema nell’indurre aumento dell’espressione di Scn1a in una linea cellulare e in neuroni primari di topo WT.Quindi abbiamo anche valutato il potenziale terapeutico di questo sistema nei neuroni primari di topo SD, i quali, una volta trattati, hanno raggiunto livelli di proteina paragonabili ai neuroni WT e hanno riacquisito la loro capacità di generare PA. Inoltre, inserendo il sistema Scn1a-dCas9 in un vettore AAV, abbiamo dimostrato la rilevanza terapeutica di questo strumento iniettandolo in cuccioli di topo SD, riportando un recupero della funzionalità degli interneuroni PV+ adulti, con l'attenuazione delle crisi febbrili. Quindi, incoraggiati da questi dati, siamo passati al modello umano per verificare se anche il gene umano SCN1A fosse responsivo al trattamento con dCas9. Per questo motivo, abbiamo innanzitutto ottimizzato un protocollo di differenziamento neuronale già pubblicato, che consente di generare ING umani da cellule staminali pluripotenti indotte. Poi, abbiamo generato staminali da fibroblasti di due pazienti con SD recanti diverse mutazioni puntiformi sul gene SCN1A. Utilizzando il CRISPR-Cas9 abbiamo isolato cloni isogenici e abbiamo differenziato tutte le linee cellulari in ING e NE cercando di stabilire un modello umano appropriato della malattia. Tuttavia, abbiamo riportato un trend di ipoeccitabilità negli ING dei pazienti analizzando la media dei PA massimi. Analizzando poi i NE, abbiamo evidenziato solo un lieve fenotipo ipereccitabile nei neuroni del paziente 1.Supponendo che il fenotipo lieve che abbiamo rivelato fosse associato ad uno stato neuronale immaturo, abbiamo cercato di porre le basi per analizzare altre condizioni di maturazione. Abbiamo introdotto un terreno specifico nelle nostre colture neuronali in modo da migliorne l'attività e la maturazione e poi abbiamo iniettato cellule umane nel cervello di topi immunodepressi, per verificarne la capacità di integrazione nella corteccia murina, in modo da poter testare con esperimenti futuri le proprietà funzionali dei neuroni migrati e integrati.Allo stesso tempo, abbiamo testato il CRISPR-dCas9 su una linea cellulare umana, e abbiamo identificato tre sgRNA in grado di aumentare l’espressione di SCN1A. L’efficienza di questi sgRNAs è stata dimostrata anche in ING di controllo derivati da staminali, i quali hanno mostrato aumento nei livelli di espressione di SCN1A e nella densità di correnta al sodio.
Dravet syndrome (DS) is a catastrophic developmental and epileptic encephalopathy characterized by severe, pharmaco-resistant seizures and a high risk of Sudden Unexpected Death in Epilepsy (SUDEP). To date, no cure is effective in controlling seizures. 80% of the patients present heterozygous loss-of-function mutations in the SCN1A gene, indicating that a haploinsufficient mechanism underlies the onset of the pathology. SCN1A encodes for the voltage-gated sodium channel alpha-subunit Nav1.1, essential to initiate action potentials (APs) in gabaergic interneurons (GINs). The analysis of different animal models pointed out that seizure development is due to a reduction of excitability of GINs, particularly of parvalbumin (PV), somatostatin (SST), and vasoactive intestinal peptide (VIP) subtypes, ultimately resulting in an over-excitation of neuronal network. However, other works also reported hyperexcitability in excitatory neurons (ExNs) during all stages of the pathology or only in the pre-epileptic stage, suggesting the involvement of this neuronal subtype in DS. Heterozygous loss-of-function mutations result from quantitative reduction of gene expression to 50% of normal levels. For this reason, we decided to employ a new strategy based on the activatory CRISPR-dCas9 to specifically raise the Nav1.1 protein levels by stimulating the transcription of the Scn1a gene in a DS mouse model. We demonstrated the efficiency of this system in upregulating Scn1a gene expression in cell line and primary WT neurons. Then, we also assessed the therapeutic potential of this system to increase Nav1.1 levels in DS primary neurons, letting them to reach protein levels comparable to WT neurons, and to rescue their ability to fire APs. Furthermore, by packaging Scn1a-dCas9 system into an AAV vector, we showed the therapeutical relevance of this tool by injecting DS pups, reporting a rescue of adult PV+ interneurons functionality, together with attenuation of febrile seizures. Then, encouraged from these data, we moved to a human setting to verify if also SCN1A gene was responsive to dCas9 treatment. For this reason, we firstly optimized a neuronal differentiation protocol already published, which allows generating human GINs from induced pluripotent stem cells (iPSCs). Then, we generated iPSCs from fibroblasts of two DS patients carrying different point mutations on SCN1A gene. By using the CRISPR-Cas9 gene-editing tool we isolated isogenic clones, and we differentiated all iPSC lines into GINs and ExNs trying to establish a proper human model. Only a trend of hypoexcitability was reported in patient GINs by analysing the mean of maximal APs. Following with ExNs functional studies, we only highlighted a mild hyperexcitable phenotype in patient 1 neurons, while no alteration was revealed analysing the second pair of iPSCs. Assuming that the mild phenotype we assessed could be associated with a not proper state of maturation of our neurons, we performed pilot experiments to set the basis to analyse other maturation conditions. We introduced a specific medium enhancing neuronal activity and maturation in our protocol, and we tried to inject our human cells into immunodeficient mouse brain, to possibly test with future experiments the functional properties of neurons migrated and integrated into the mouse cortex. At the same time, we finally explored the activatory CRISPR-dCas9 in SHSY-5Y cell line, by performing an sgRNAs screening of three different regions placed in proximity of the three SCN1A transcription start sites. We identified three sgRNAs able to increase SCN1A gene expression levels, whose efficiency was also demonstrated in control iPSC-derived GINs. Indeed, dCas9-treated neurons, not only demonstrated to express a higher level of SCN1A, but also, they showed an increase in the sodium current. With these results, we demonstrated that also the human SCN1A gene promoter is responsive to the activatory CRISPR-dCas9 treatment.

APA, Harvard, Vancouver, ISO, and other styles

48

DE, FLORIAN FANIA ROSSELLA. "Identification and characterization of therapeutic molecules affecting expression levels of the tumor suppressor DAB2IP in cancer." Doctoral thesis, Università degli Studi di Trieste, 2023. https://hdl.handle.net/11368/3042421.

Full text

Abstract:

In tumors, the reciprocal communication between malignant cells and non-transformed stromal cells involves a variety of signaling proteins and modulators that cooperate to control proliferation, migration and apoptosis. Among them, the tumor suppressor DAB2IP, a Ras-GAP and signaling adaptor protein, modulates signal transduction in response to several extracellular stimuli, negatively regulating multiple oncogenic pathways. Accordingly, the loss of DAB2IP in tumor cells fosters metastasis and enhances chemo- and radio-resistance. DAB2IP is rarely mutated in cancer but is frequently downregulated or inactivated by multiple mechanisms. Solid experimental evidences indicate that DAB2IP reactivation can reduce cancer aggressiveness in tumors driven by multiple different oncogenic mutations. In this regard, we showed that the ectopic overexpression of DAB2IP is sufficient to significantly affect the behavior of prostate cancer cells, possibly slowing tumor dissemination. All these evidences indicate DAB2IP as a strong target for anti-cancer therapy. Nevertheless, therapeutic approaches to increase DAB2IP function in cancer are still not available. Based on these observations, we performed a high-throughput screening with more than 1200 FDA- approved drugs to search for molecules that increase DAB2IP protein levels. Since detection of endogenous DAB2IP is technically difficult due to relatively low expression levels and the limitations of available antibodies, we exploited CRISPR/Cas9 gene editing to generate two prostate cancer cell models expressing endogenous DAB2IP fused to HiBiT, a peptide tag that enabled luminescence- based detection of protein levels in a sensitive and quantitative manner. Using this approach, we identified a set of candidate drugs able to increase DAB2IP levels. We focused our attention on the three more effective drugs: one antibacterial, one antileukemic and one antiasthmatic. Although not conclusive, functional experiments indicate that DAB2IP-upregulating drugs can inhibit some cancer-associated phenotypes, and that some of these effects are at least in part dependent on DAB2IP. These findings, if further confirmed, may suggest a potential repurposing of these drugs for solid cancers’ treatment, as support to current therapies.
In tumors, the reciprocal communication between malignant cells and non-transformed stromal cells involves a variety of signaling proteins and modulators that cooperate to control proliferation, migration and apoptosis. Among them, the tumor suppressor DAB2IP, a Ras-GAP and signaling adaptor protein, modulates signal transduction in response to several extracellular stimuli, negatively regulating multiple oncogenic pathways. Accordingly, the loss of DAB2IP in tumor cells fosters metastasis and enhances chemo- and radio-resistance. DAB2IP is rarely mutated in cancer but is frequently downregulated or inactivated by multiple mechanisms. Solid experimental evidences indicate that DAB2IP reactivation can reduce cancer aggressiveness in tumors driven by multiple different oncogenic mutations. In this regard, we showed that the ectopic overexpression of DAB2IP is sufficient to significantly affect the behavior of prostate cancer cells, possibly slowing tumor dissemination. All these evidences indicate DAB2IP as a strong target for anti-cancer therapy. Nevertheless, therapeutic approaches to increase DAB2IP function in cancer are still not available. Based on these observations, we performed a high-throughput screening with more than 1200 FDA- approved drugs to search for molecules that increase DAB2IP protein levels. Since detection of endogenous DAB2IP is technically difficult due to relatively low expression levels and the limitations of available antibodies, we exploited CRISPR/Cas9 gene editing to generate two prostate cancer cell models expressing endogenous DAB2IP fused to HiBiT, a peptide tag that enabled luminescence- based detection of protein levels in a sensitive and quantitative manner. Using this approach, we identified a set of candidate drugs able to increase DAB2IP levels. We focused our attention on the three more effective drugs: one antibacterial, one antileukemic and one antiasthmatic. Although not conclusive, functional experiments indicate that DAB2IP-upregulating drugs can inhibit some cancer-associated phenotypes, and that some of these effects are at least in part dependent on DAB2IP. These findings, if further confirmed, may suggest a potential repurposing of these drugs for solid cancers’ treatment, as support to current therapies.

APA, Harvard, Vancouver, ISO, and other styles

49

Souza, Gustavo Torres de. "Produção de células MDBK expressando a enzima CAS9 e edição do gene da beta-lactoglobulina pelo sistema CRISPR/Cas9." Universidade Federal de Juiz de Fora (UFJF), 2017. https://repositorio.ufjf.br/jspui/handle/ufjf/6049.

Full text

Abstract:

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-08T14:33:50Z No. of bitstreams: 1 gustavotorresdesouza.pdf: 5085443 bytes, checksum: eada917698a8738ea1947743e940692c (MD5)
Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-01-23T11:05:29Z (GMT) No. of bitstreams: 1 gustavotorresdesouza.pdf: 5085443 bytes, checksum: eada917698a8738ea1947743e940692c (MD5)
Made available in DSpace on 2018-01-23T11:05:29Z (GMT). No. of bitstreams: 1 gustavotorresdesouza.pdf: 5085443 bytes, checksum: eada917698a8738ea1947743e940692c (MD5) Previous issue date: 2017-08-08
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
O advento sistema CRISPR/Cas9 tornou o processo de edição gênica consideravelmente mais fácil e direto, uma vez que retirou empecilhos técnicos relacionados aos sistemas já disponíveis. Desta forma, foram permitidos diversos avanços no entendimento da função de elementos genômicos, assim como a produção de embriões geneticamente modificados com diversas finalidades. O atual trabalho objetivou a edição gênica no gene da beta-lactoglobulina em células somáticas bovinas objetivando a produção futura de embriões da espécie geneticamente modificados. Considerando-se que a hipersensibilidade a essa proteína responde pela maior parte das alergias ao leite bovino, a produção de animais cujo leite não contenha essa molécula é de grande interesse para a indústria de laticínios. Durante os experimentos, foi possível obter uma linhagem de células bovinas MDBK expressando a enzima Cas9 (MDBK-Cas). Usando células MDBK e as células MBDK-Cas foi possível se obter com sucesso edições gênicas no locus beta-lactoglobulina utilizando-se os componentes do sistema CRISPR/Cas9 na forma de mRNA da proteína Cas9 e sgRNAs. Conclui-se que o sistema CRISPR/Cas9 pode ser usado com os sgRNA desenhados neste estudo para editar o gene da betalactoglobulina em células MDBK. Assim, células MDBK podem ser utilizadas como alvo o locus em estudo. Modelos de estudos para edição do genoma bovino. Em vista da escassa literatura constando de trabalhos em que tenha sido feita a edição gênica em embriões bovinos, os dados gerados por esse trabalho colaborarão para o avanço do estado da arte no que diz respeito a engenharia gênica de bovinos e no conhecimento do funcionamento do sistema CRISPR/Cas9.
The advent of the CRISPR / Cas9 system made the process of gene editing considerably easier and more straightforward, since it removed technical impediments related to the systems already available. In this way, several advances were made in the understanding of the function of genomic elements, as well as the production of genetically modified embryos for various purposes. The present work aimed at the genetic editing of the beta-lactoglobulin gene in bovine somatic cells aiming at the future production of genetically modified embryos of the species. Considering that hypersensitivity to this protein accounts for most of the allergies to bovine milk, the production of animals whose milk does not contain this molecule is of great interest to the dairy industry. During the experiments, it was possible to obtain a lineage of bovine MDBK cells expressing the Cas9 enzyme (MDBK-Cas). Using MDBK cells and MBDKCas cells it was possible to successfully obtain gene editions at the beta-lactoglobulin locus using the components of the CRISPR / Cas9 system as mRNA of the Cas9 protein and sgRNAs. It is concluded that the CRISPR / Cas9 system can be used with the sgRNAs designed in this study to edit the beta-lactoglobulin gene in MDBK cells. Thus, MDBK cells can be targeted as the locus under study. Models of studies for editing the bovine genome. In view of the scarce literature consisting of studies in which bovine embryos have been genetically engineered, the data generated by this work will contribute to the advancement of the state of the art regarding the genetic engineering of cattle and the knowledge of the functioning of the system CRISPR / Cas9.

APA, Harvard, Vancouver, ISO, and other styles

50

Costa, Alexandre Augusto. "Avaliação da eficácia da legislação penal ambiental na conservação de áreas naturais e na preservação da ictiofauna autóctone." Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/1794.

Full text

Abstract:

Made available in DSpace on 2016-06-02T19:29:54Z (GMT). No. of bitstreams: 1 5018.pdf: 2520100 bytes, checksum: e319d300926f01d1ea5bcfbf52683290 (MD5) Previous issue date: 2013-04-05
The analysis of information from the prosecution of legal instruments allows not only rational underpinning the development of public policies to conserve natural resources, as also promotes the constant improvement of the repressive legislation of conduct considered detrimental to the environment. The objective of this study has been assessing the effectiveness of legal protection models adopted by the criminal law in force in environmental area characterized by full economic development and subjected to intense and constant anthropogenic threats. So, we studied the region of Sao Jose do Rio Preto, northwest of Sao Paulo state, Brazil. We analyze the feasibility of legal instruments for the protection of natural areas on private property and subjected to anthropogenic pressures for land use. The results indicate that the increased demand for areas intended for food production and biofuels represents one of the greatest challenges to the preservation of natural resources in Brazil. The juridical protection is insufficient to guarantee the conservation of natural areas, requiring for the success of conservation strategies the development and implementation of participatory management projects. Withal, we evaluated the effectiveness of the typical structuring technique taken into account by the environmental crimes law in preserving autochthonous fish fauna. The results indicate that the tutelage technique of environmental legislation is effective in controlling fishing activities, mainly due to the high incidence of non-selective means of capture and the prevalence autochthonous species against non-autochthonous (allochthonous and exotics) species. Although environmental legislation constitutes an important tool for protection of natural resources its effectiveness is directly subjected to the development and deployment of other concomitant conservation strategies, particularly the development of comprehensive and active policies, able to overcome the challenge of reconciling the socio-economic interests and conservationist interests.
A analise de informacoes provenientes dos instrumentos juridicos de repressao penal pode nao apenas alicercar a implantacao racional de politicas publicas de conservacao dos recursos naturais, como, ainda, promover o constante aperfeicoamento da legislacao repressora das condutas consideradas lesivas ao meio ambiente. O objetivo do trabalho consistiu em avaliar a eficacia de modelos de protecao juridica adotados pela legislacao penal ambiental vigente em area caracterizada por pleno desenvolvimento economico e submetida a intensas e constantes ameacas antropogenicas. Para tanto, utilizou-se a regiao de Sao Jose do Rio Preto, noroeste do estado de Sao Paulo. Analisou-se a viabilidade dos instrumentos legais para a protecao de areas naturais inseridas em propriedades privadas e submetidas a pressoes antropogenicas pelo uso da terra. Os resultados apontam que o aumento na demanda por areas destinadas a producao de alimentos e de biocombustiveis representa um dos maiores desafios a preservacao dos recursos naturais no Brasil. A protecao juridica revelou-se insuficiente a garantir a conservacao das areas naturais, exigindo, para o sucesso das estrategias conservacionistas, o desenvolvimento e a implantacao de projetos de manejo participativos. Paralelamente, avaliou-se a eficacia da tecnica de estruturacao tipica adotada pela lei de crimes ambientais na preservacao da ictiofauna autoctone. Os resultados indicam que a tecnica de tutela da legislacao ambiental mostra-se eficaz no controle das atividades de pesca predatoria, sobretudo em funcao da elevada incidencia de meios nao-seletivos de captura e da prevalencia de especies autoctones em relacao as nao-autoctones (aloctones e exoticas). Ainda que a legislacao ambiental constitua importante ferramenta na protecao dos recursos naturais, sua eficacia esta diretamente condicionada ao desenvolvimento e a implantacao concomitante de outras estrategias de conservacao, sobretudo o desenvolvimento de politicas publicas abrangentes e atuantes, capazes de superar o desafio de conciliacao entre os interesses socioeconomicos e os interesses conservacionistas.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Biological Crises'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles