Dissertations / Theses on the topic 'Necrosis'
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Bridges, James. "Necrosis in colorectal cancer /." Leeds : University of Leeds, School of Computer Studies, 2008. http://www.comp.leeds.ac.uk/fyproj/reports/0708/Bridges.pdf.
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Albataineh, Eman Mohammad. "Studies of tumour necrosis factor receptor-1 in tumour necrosis factor receptor associated periodic sysndrome (TRAPS)." Thesis, University of Nottingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.537655.
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Dry, P. R. "Primary bud-axis necrosis of grapevines /." Title page, contents and summary only, 1986. http://web4.library.adelaide.edu.au/theses/09A/09ad798.pdf.
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Naylor, Michael Stuart. "Tumour necrosis factor and ovarian cancer." Thesis, Open University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332896.
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Braidwood, Luke Anthony. "Engineering resistance to maize lethal necrosis." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/273678.
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Modern agriculture is dependent on both global supply chains and crop monocultures. These features aid the evolution and spread of novel plant pathogens. Limited genetic diversity in commercial crop lines can result in widespread susceptibility to emerging pathogens. Pathogen resistance may be developed through conventional breeding approaches, or a number of transgenic strategies. This thesis focuses on the characterisation of an emerging maize disease, Maize lethal necrosis (MLN), and engineering resistant maize lines using an artificial microRNA (amiRNA) approach. MLN is a synergistic viral disease caused by the interaction of Maize chlorotic mottle virus (MCMV) with any maize-infecting member of the potyviridae. I used next-generation RNA sequencing to characterise the MLN outbreak in East Africa, discovering that local and Chinese strains of the potyvirus Sugarcane mosaic virus (SCMV) typically coinfect with MCMV. A first global MCMV phylogeny was constructed using these samples combined with new Sanger sequencing of samples in Ecuador and Hawaii. The phylogeny supported previous hypotheses of a link between the Chinese and African outbreaks, and suggested a novel link between the Hawaiian and Ecuadorian outbreaks. The SCMV sequences generated demonstrated strong evidence of extensive recombination, in line with previous reports on SCMV and potyviruses. These data also produced first reports of a number of RNA viruses in East Africa, and five novel viral-like sequences, with their presence confirmed by RT-PCR. RNA silencing is an important component of the plant immune response to viral infection. amiRNAs can be used to generate specific and effective viral resistance through Watson- Crick base pairing between the amiRNA and the (RNA) viral genome. Previous amiRNA approaches have targeted invariable genomic regions using consensus sequences. However, the high mutation rate of RNA viruses means single cells contain a variety of mutant genomes, collectively called a quasispecies. To deter the evolution of resistance breaking I devised a novel strategy to include intra-sample variation from NGS data in amiRNA design, and constructs, each containing five of these amiRNAs, were transformed into tropical maize lines. RNA silencing may be hampered by the expression of viral suppressors of silencing (VSRs). Local VSR assays demonstrated that there are no local VSRs in the MCMV genome, while systemic VSR assays showed a possible systemic VSR role for the unique P32 protein, and an interesting link between photoperiod and systemic silencing more generally.
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Björnberg, Flemming. "Processing of TNF-receptors to soluble receptor forms in myeloid cells." Lund : Dept. of Hematology, Lund University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/39176479.html.
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Green, Ian R. "Studies on ovine tumour necrosis factor alpha." Thesis, University of Edinburgh, 1994. http://hdl.handle.net/1842/29788.
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Tumour necrosis factor alpha (TNFα), a mediator of inflammatory responses and pathologies of a wide variety of diseases, has been extensively studied in humans and mice. However, little has previously been known about this cytokine in the sheep, a species of value not only to the agricultural industry, but also as a laboratory animal. In this work, the cDNA encoding ovine TNFα has been amplified, cloned, sequenced and used to express recombinant ovine TNFα (rovTNFα). The latter has been partially purified, characterised and used to raise both poly- and mono- clonal antibodies. The sequence of ovine TNFα shows a high degree of homology to those of other species. Certain regions, which are known to be structurally or functionally important to the mRNA and/or protein, are particularly well conserved. Consequently, rovTNFα displays several biological activities previously noted for TNF'sα of other species, including cytotoxicity, enhancement of thymocyte and fibroblast profileration and cartilage-degrading and anti-viral activities. However, whilst rovTNFα is active in assays on ovine cells at concentrations comparable to those observed in similar assays for other species, it is 1000 fold less active than recombinant human TNFα (rhTNFα) in cytotoxicity assays on TNF-sensitive murine (L929) cells, whose general lack of species specificity allows their use in detecting TNF'sα from many sources. A monoclonal antibody raised to rovTNFα detects a glycoprotein of appropriate size for mature ovine TNFα in the supernatants of stimulated ovine cell cultures. As in other species both ovine TNFα mRNA and protein are rapidly inducible. Such supernatants repeatedly have no activity in cytotoxicity assays (sensitive to 30pg rhTNFα/ml) on L929 cells, in spite of many containing >1ng ovine TNFα/ml.
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Stewart, Victoria C. "Human renal lipoxygenases : implications for papillary necrosis." Thesis, University of Aberdeen, 1995. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU078660.
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The long-term administration or abuse of analgesics and therapeutic doses of non-steroidal anti-inflammatory drugs have been implicated in renal papillary necrosis (RPN). Several drugs implicated in RPN undergo metabolic activation, via prostaglandin synthetase (PGS) and / or lipoxygenase (LO) systems in papilla, forming potentially damaging free radicals, providing an attractive theory to account for the necrosis. This thesis demonstrated interspecies and intrarenal variation in terms of renal PGS and LO activities. PGS was primarily responsible for arachidonic acid (AA)-dependent metabolism of xenobiotics in rabbit, while in a combination of PGS and LO catalysed drug cooxidation in rat kidney. In contrast in man, AA-dependent cooxidation of drugs in renal tissue occurred via the 5-lipoxygenase, which was predominately located in the papilla. These results indicated that the commonly used laboratory animals, rabbit and rat, are not suitable models for studying RPN in man. These studies also offer a potential explanation for a long-standing anomaly. PGS was thought to be central to the development of RPN but it has been difficult to equate the involvement of PGS with the fact that many papillotoxic compounds are also PGS inhibitors (eg, indomethacin, mefenamic acid). However, this study suggests that 5-LO may be responsible for RPN, either by metabolic activation of drugs or production of pro-inflammatory 5-LO products, altering the renal eicosanoid balance and subsequently renal haemodynamics, thereby precipitating necrosis. This hypothesis was further strengthened by the increased activity of renal 5-LO noted in animal models of both diabetic- and chemically-induced papillotoxicity. Unfortunately, administration of 5-LO inhibitors did not protect against this chemically-induced papillotoxicity. It is possible that inhibitors of 5-LO may provide protection against, or reverse, drug- or disease-induced nephropathy.
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Schobesberger, Martina. "Oligodendroglial degeneration in distemper : apoptosis or necrosis? /." [S.l.] : [s.n.], 1998. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Jaramillo, Martinez Diana. "Epidemiology and pathogenesis of Nervous Necrosis Virus." Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/13088.
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Viral Nervous Necrosis (VNN) is a globally distributed disease that affects a large number of finfish species, causing significant economic losses on affected farms. The causative agent is a small single stranded RNA virus called Nervous Necrosis Virus (NNV) from the genus Betanodavirus. NNV is neurotropic; clinical signs involve abnormal behaviour and high mortality associated with histopathological findings of vacuolating necrosis in the central nervous system and retina. In Australia, NNV has been isolated from Australian bass (Macquaria Novemaculeata) and barramundi (Lates calcarifer) populations recurrently for the past 10 and 25 years, respectively. However, the prognosis of NNV infection is highly variable. Although NNV became notorious for mass mortalities in marine fish hatcheries, it is often detected in apparently healthy individuals in the absence of clinical signs or histopathological lesions. Current knowledge on NNV epidemiology and pathogenesis is fragmentary. It is still unclear how the virus is transmitted between hosts and why some individuals are susceptible to VNN while others are not. The aim of this work was to study the epidemiology and pathogenesis of NNV in Australian native species with a focus on transmission and disease determinants to provide a basis for the development of prevention and control strategies. In Chapter 3, a partially retrospective study was conducted on the occurrence of NNV at the Darwin Aquaculture Centre (DAC), a barramundi hatchery. Observations on NNV detection frequency and distribution provided clues to the possible transmission pathways of the virus, including the potential role of broodstock as reservoirs, and the age-dependency of the disease. To assess the NNV exposure distribution among populations of adult fish, an indirect antibody detection ELISA was developed (Chapter 4). The assay was optimized and compared with a competitive ELISA format to provide the best discriminatory power between sera from immunized and non-immunized populations. After defining the best antibody detection protocol (the indirect ELISA), the diagnostic accuracy of the assay was assessed in naturally exposed subjects using a Bayesian approach in the absence of a gold standard (Chapter 5). After validation of the ELISA, a single point and repeated cross sectional analysis of NNV seroprevalence was conducted on native Australian adult fish populations (barramundi, Australian bass and groupers Epinephelus sp.) (Chapter 6). Survey results discredited the role of broodstock as NNV reservoirs based on the lack of correspondence between NNV seroprevalence and the occurrence of NNV outbreaks at the hatchery level. Results also suggested that the exposure of adult fish to NNV antigens must be progressive as seroconversion was often observed and the seroprevalence tended to be higher in older fish populations. From this and previous accumulated epidemiological evidence, horizontal transmission of NNV was considered most likely. An environmental reservoir outside the hatcheries has yet to be investigated. In Chapter 7, the factors influencing the pathogenesis of NNV in barramundi were explored. Juveniles of different ages were challenged by immersion to analyse the influence of the age of the host on VNN disease expression. Additionally, to test the influence of the virus isolate, juveniles were challenged with two inoculums obtained from NNV outbreaks in barramundi populations with different disease presentation (clinical and subclinical). Results showed that fish from all the age groups tested (range 20 to 63 days post hatch) were susceptible to NNV infection. However, the survival of the fish following NNV challenge was highly influenced by the age of the host. Juveniles of 5 weeks of age and older showed no clinical signs and their survival odds were the same as the non-challenged controls, whereas younger fish developed clinical disease. No significant effect on disease severity was noted between different NNV isolates. In Chapter 8, the factors influencing the pathogenesis of NNV in Australian bass were explored. In addition to the age of the host and the isolate factor, the influence of the dose of the virus and the water temperature on VNN expression was examined. As with barramundi, the disease expression in Australian bass was age dependent. The severity of the disease was affected by the water temperature in younger fish but it did not affect the outcome in fish above 5 weeks of age. The dose of the virus influenced the incidence of infection but not the severity of the disease expression. Again, no significant effect on disease severity was noted between the two isolates tested. From the experimental challenge of barramundi and Australian bass, further observations on NNV pathogenesis were provided: incubation period, minimum infectious dose, tissue distribution, shedding and humoral immune response. The results from this study narrow the knowledge gap on NNV transmission mechanisms and provide important insights into the virus pathogenesis in barramundi and Australian bass. The virus is most likely being transmitted horizontally and VNN disease expression as distinct from infection with NNV is highly age dependent. From this evidence, recommendations are made on the direction of efforts to control VNN at the farm level.
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Doerge, Thomas A., Deborah Young, and Claire Owen. "Internal Bark Necrosis in Southeastern Arizona Apples." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/215718.
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Moriguti, Eny Kiyomi Uemura. "Efeito da L-alanil-L-glutamina na forma de dipeptídeo e L-glutamina-L-alanina na forma de aminoácido livre na evolução da necrose de lesão por queimaduras em ratos." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17137/tde-10042018-143956/.
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Introdução: A classificação da gravidade da queimadura é determinada a partir da relação entre a superfície corporal queimada (SCQ) e a profundidade da lesão. Os fatores que influenciam a evolução da necrose na zona de estase que circunda a zona de necrose (coagulação) podem estar relacionados com a perfusão, inflamação e estresse oxidativo. No presente estudo avaliamos o efeito da glutamina, pois tem sido demonstrado ter papel importante na prevenção de lesão por isquemia e reperfusão, da inflamação e do estresse oxidativo. Objetivo: avaliar o efeito da glutamina na forma de aminoácido livre e dipeptídeo na evolução da necrose nos interespaços (zona de estase) da queimadura. Materiais e Métodos: Foram utilizados 30 ratos machos da linhagem Wistar. Em todos os animais foi feito a lesão por queimadura de terceiro grau com um pente de metal contendo quatro dentes e três interespaços pré aquecido em água à 98ºC. O Grupo 1- Controle (n=10) recebeu 7,4ml/kg de peso, de solução fisiológica a 0,9%, o Grupo 2- Dipeptídeo, recebeu 7,4 ml do dipeptídeo L-alanil-L-glutamina (1g/kg de L-glutamina e 0,6g/kg de L-Alanina) e o Grupo 3- AA-livre recebeu 1g/kg de L-glutamina e 0,6g/kg de L-alanina na forma de aminoácido livre, por gavagem, por 7 dias após a lesão por queimadura. As análises avaliadas foram por meio de fotografia (no momento 48 horas e 7 dias) e histopatologia (no 7º dia após a lesão), para avaliar a extensão da necrose, alterações isquêmicas nos interespaços (zona de estase), além da alteração da Glutationa. Resultado: Na avaliação fotográfica, houve redução significante da necrose especificamente no Grupo 3- AA-livre entre o momento 48 horas e sete dias (P=0,04). Na avaliação por histologia, globalmente houve redução da inflamação nos Grupos 2- Dipeptídeo e 3- AA-livre quando comparados com o Grupo 1- Controle (p< 0,01). Ainda nos grupos tratados houve tendência a redução de necrose na derme dos interespaços ( Grupo 1- Controle =0,95; Grupo 2- Dipeptídeo =0,73 e Grupo 3- AA-livre =0,8), mas essas diferenças não foram significantes. Os grupos tratados também apresentaram aumento do número de fibroblastos quando comparados ao Grupo 1- Controle (p<0,05). Na dosagem de Glutationa foi encontrado maior quantidade no Grupo 2- Dipeptídeo (p<0,05) quando comparado com o Grupo 1- Controle. Conclusão: A redução das lesões histológicas, redução da inflamação, manutenção de maior extensão dos interespaços, a maior quantidade de fibroblastos e o aumento da glutationa, com a administração de glutamina, observados no presente estudo, podem ter beneficiado a manutenção ou redução da evolução da necrose de queimadura em ratos.a inflamação, acelerou a cicatrização e regrediu a evolução da necrose das zonas de estase das queimaduras em ratos.Introduction: The classification of burn severity is based on the relationship between the burned body surface (SCQ) and the depth of the lesion. Factors influencing the progression of necrosis in the stasis zone surrounding the area of necrosis (coagulation) may be related to perfusion, inflammation and oxidative stress. In the present study, we evaluated the effect of glutamine, as it has been shown to play an important role in the prevention of ischemia and reperfusion injury, inflammation and oxidative stress. Objective: to evaluate the effect of glutamine as a free amino acid and dipeptide on the progression of necrosis in the interspace (stasis zone) of the burn. Materials and Methods: Thirty male Wistar rats were used. In all animals a third degree burn injury was done with a metal comb containing four teeth and three interspaces preheated in water at 98ºC. Group 1- Control (n = 10) received 7,4 ml of 0.9% saline solution, Group 2- Dipeptide received 7.4 ml of dipeptide solution L-alanyl-L-glutamine (1g/k Lglutamine and 0.6g/k L-Alanine) and Group 3- Free AA received 1g/k L-glutamine and 0,6g/kg L-alanine as free amino acid, by gavage, for 7 days after burn injury. The analyzes evaluated were by means of photograph (in the time 48 hours and 7 days) and histopathology (on the 7th day after the injury), to evaluate the extent of necrosis, ischemic changes in the interspaces (stasis zone), besides the alteration of Glutathione . Results: In the photographic evaluation, there was a significant reduction of necrosis specifically in the 3-AA-free group between 48 hours and 7 days (P = 0.04). Histologically, there was a reduction in inflammation in Groups 2- Dipeptide and 3-AA-free when compared to Group 1-Control (p <0.01). Even in the treated groups there was a tendency to reduce necrosis in the interspaces dermis (Group 1-Control = 0.95, Group 2-Dipeptide = 0.73 and Group 3- AA-free = 0.8), but these differences were not significant. The treated groups also showed an increase in the number of fibroblasts when compared to Group 1- Control (p <0.05). In the dosage of Glutathione, a greater amount was found in Group 2 - Dipeptide (p <0.05) when compared to Group 1 - Control. Conclusion: The reduction of histological lesions, reduction of inflammation, maintenance of greater extension of the interspaces, the greater amount of fibroblasts and the increase of glutathione, with the administration of glutamine observed in the present study, may have benefited the maintenance or reduction of the evolution of necrosis of burn in rats.
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Offei, Samuel K. "Molecular analysis of the tobacco necrosis virus genome." Thesis, Imperial College London, 1995. http://hdl.handle.net/10044/1/11319.
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Johnston, Julie Catherine. "In vitro translation of cucumber necrosis virus RNA." Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/28969.
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The in vitro translation products directed by cucumber necrosis virus (CNV) RNA were analyzed in both rabbit reticulocyte lysate and wheat germ extract cell-free translation systems. In rabbit reticulocyte lysates, one major protein of ca. 33 Mr was produced. In wheat germ extracts, four proteins of ca. 41, 33, 21 and 20 Mr were produced. Hybrid-arrested translation (HART) studies using synthetic CNV antisense RNA corresponding to the entire CNV genome demonstrated that the four major proteins synthesized from CNV virion RNA in wheat germ extracts are virus-specific translation products. The genomic locations of the CNV in vitro translation products were determined using a number of experimental approaches including: (1) HART using antisense RNA corresponding to selected regions of the CNV genome; (2) in vitro translation of synthetic messenger-sense CNV transcripts; (3) immunoprecipitation of in vitro translation products with CNV polyclonal antisera and (4) in vitro translation of size-fractionated CNV virion RNA. Together, these experiments demonstrated that the ca. 33 Mr protein is derived from the 5' proximal coding region, the ca. 41 Mr protein is derived from an internal coding region, and that at least one but probably both of the ca. 20 and 21 Mr proteins are derived from the 3' terminal coding region(s) of the CNV genome. In addition, immunoprecipitation experiments provided further evidence that the ca. 41 Mr protein is the viral coat protein. The size, number, and genomic locations of the CNV in vitro translation products reported here are in agreement with those predicted from nucleotide sequence data (Rochon & Tremaine, 1989). The natural template for the expression of downstream cistrons in the CNV genome was investigated by in vitro translation of sucrose fractionated CNV virion RNA as well as in vitro translation of messenger-sense synthetic transcripts. These studies indicate that in vitro, both subgenomic and genomic-length CNV RNA molecules may act as templates for the synthesis of the ca. 41,21 and 20 Mr proteins as well as the ca. 33 Mr protein.Land and Food Systems, Faculty of
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Molloy, Sally Dixon. "A DNA Vaccine Against Infectious Pancreatic Necrosis Virus." Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/MolloySD2007.pdf.
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Engelberts, Ingeborg. "Tumor necrosis factor during sepsis king of cytokines? /." Maastricht : Maastricht : Universitaire Pers Maastricht ; University Library, Maastricht University [Host], 1994. http://arno.unimaas.nl/show.cgi?fid=6955.
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Pérez, Lozano Alba Astril. "PATOGENIA DEL VIRUS DE LA NECROSIS PANCREÁTICA INFECCIOSA." Tesis de Licenciatura, Universidad Autónoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/95135.
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La presente tesina es una revisión bibliográfica sistemática y exhaustiva de la patogenia del virus de la necrosis pancreática infecciosa, con base en la teoría respuesta – daño; propuesta por Casadevall y Pirofski (2003).RESUMEN El virus de la necrosis pancreática infecciosa (VNPI) es el agente causal de la enfermedad conocida como necrosis pancreática infecciosa (NPI). De manera natural los salmónidos son los peces más susceptibles. El curso agudo de la enfermedad puede provocar una mortalidad hasta del 100% en salmónidos jóvenes. En las truchas, la susceptibilidad a la enfermedad disminuye con la edad. Los peces infectados transmiten el virus por vía horizontal y vertical, esto promueve que el virus se encuentre de forma continua en el agua y que infecte a otros peces. Al alcanzar los 1500 grados-día (valor que se obtiene multiplicando los días de edad de los peces, por el promedio de la temperatura en grados Celsius durante su esperanza de vida), los peces resisten más a la enfermedad. Los signos clínicos que presentan los peces afectados por el VNPI son: anorexia, ataxia, hiperventilación, obscurecimiento de piel (hiperpigmentación), hemorragias en áreas ventrales y aletas. Con base en ésto, un pez puede estar infectado mas no enfermo, y un pez enfermo sí está infectado. Por la complejidad del proceso salud - enfermedad, Casadevall y Pirofski propusieron una nueva teoría de la patogenia microbiana, empleando modelos de microorganismos patógenos en los humanos. Esto nos lleva a revisar los conceptos propuestos por estos autores, haciendo énfasis en modelos de patógenos importantes en el área de la Medicina Veterinaria. En nuestro país, el virus de la necrosis pancreática infecciosa fue reportado en 2002 y afecta principalmente a truchas jóvenes de unidades de producción intensiva. El virus ha sido aislado en unidades de producción trutícola de las siguientes entidades: México, Hidalgo, Morelos, Michoacán, Puebla, Chihuahua, Durango y Veracruz. Conocer la patogenia microbiana del único virus identificado y confirmado hasta ahora en la trutícultura nacional es de vital importancia. Palabras clave: patogenia microbiana, VNPI, trucha arcoíris.
“Serotificación y virulencia de aislados mexicanos del virus de la necrosis pancreática infecciosa”, financiado por CONACYT, CB-257781, con registro interno 4226/2016C; responsable técnico Dra. en C. Celene Salgado Miranda.
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Brodowicz, Gary Ray. "Exercise training, indomethacin, and isoproterenol-induced myocardial necrosis /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265555440899.
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Krugten, Michiel Volkert van. "Tumor necrosis factor gene polymorphisms and rheumatic diseases /." Leiden, 2003. http://catalogue.bnf.fr/ark:/12148/cb40223074h.
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Oukacha, Khadija. "Perturbation chimique du transport de Tumor Necrosis Factor." Electronic Thesis or Diss., Université Paris sciences et lettres, 2023. http://www.theses.fr/2023UPSLS067.
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Alors qu'il est essentiel pour lutter contre les agents pathogènes, TNF (Tumor Necrosis factor) secrété́ en excès devient nocif pour l'organisme comme dans le cas de maladies inflammatoires chroniques (polyarthrite rhumatoïde ou maladie de Crohn). Les thérapies actuelles sont basées sur des injections récurrentes d'anti-TNF contre lesquelles 30% des patients développent une résistance. Il existe donc un fort besoin de composés chimiques réduisant la sécrétion de TNF. Nous avons exploité la diversité́ des voies de sécrétion dépendantes de l’appareil de Golgi pour identifier des molécules inhibant spécifiquement la sécrétion de TNF. L’outil RUSH (Retention Using Selective Hooks) a permis la synchronisation et l’analyse du transport de TNF dans les cellules HeLa. En combinant le test RUSH à un criblage phénotypique différentiel de banques chimiques, 85 molécules inhibant le transport de TNF ont été sélectionnées. Les effets de certaines molécules ont été validés. Seules les molécules inhibantes au moins 40% de la sécrétion de TNF ont été retenues. La spécificité de ces molécules sur le transport d’autres protéines, à savoir EGFP-GPI et IL-6 a été évaluée. Les 14 molécules inhibantes plutôt spécifiquement la sécrétion de TNF ont été retenues pour poursuivre leur caractérisation en modèle physiologique.Les effets des molécules sur la sécrétion endogène de TNF et d’autres cytokines ont été mesurés dans des monocytes et des macrophages primaires humains issus du sang de donneurs après incubation avec du lipopolysaccharide (LPS) bactérien. Ces expériences en modèles physiologiques ont mis en évidence trois molécules capables d'inhiber significativement la sécrétion endogène de TNF sans affecter la sécrétion d'IL-8. Des expériences de dose-réponse et l’évaluation des effets des molécules sur l’expression de TNF ont été réalisées pour aider dans la compréhension du mode d’action de ces molécules.En conclusion, le criblage chimique, les expériences en modèle hétérologue puis en modèles physiologiques ont permis d'identifier 3 molécules inhibant la sécrétion de TNF. Ces résultats confirment que la diversité́ des voies sécrétoires est suffisamment grande pour cibler le transport d'une protéine impliquée dans une maladie et pourraient ouvrir la voie à des traitements alternatifs ou complémentaires contre les maladies inflammatoiresWhile it is essential to fight against pathogens, TNF (Tumor Necrosis factor) secreted in excess becomes harmful to the body as in the case of chronic inflammatory diseases (rheumatoid arthritis or Crohn's disease). Current therapies are based on recurrent injections of anti-TNF against which 30% of patients develop resistance. There is therefore a strong need for chemical compounds which reduce the secretion of TNF. We have exploited the diversity of secretory pathways dependent on the Golgi apparatus to identify molecules that specifically inhibit TNF secretion. The RUSH (Retention Using Selective Hooks) tool allowed the synchronization and analysis of TNF transport in HeLa cells. By combining the RUSH assay with a differential hight content screening of chemical libraries, 85 molecules inhibiting TNF transport were selected. The effects of certain molecules have been validated. Only molecules inhibiting at least 40% of TNF secretion were retained. The specificity of these molecules on the transport of other proteins, namely EGFP-GPI and IL-6 was evaluated. The 14 molecules rather specifically inhibiting the secretion of TNF were selected to continue their characterization in a physiological model.The effects of the molecules on the endogenous secretion of TNF and other cytokines were measured in human primary monocytes and macrophages obtained from blood donors after incubation with bacterial lipopolysaccharide (LPS). These experiments in physiological models have demonstrated three molecules capable of significantly inhibiting the endogenous secretion of TNF without affecting the secretion of IL-8. Dose-response experiments and the evaluation of the effects of molecules on the expression of TNF have been carried out to help in understanding the mode of action of these molecules.In conclusion, the chemical screening, the experiments in heterologous model then in physiological models made it possible to identify 3 molecules inhibiting the secretion of TNF. These results confirm that the diversity of secretory pathways is large enough to target the transport of a protein involved in a disease and could open the way to alternative or complementary treatments against inflammatory diseases
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Helliwell, Timothy Richard. "Investigations into skeletal muscle damage and regeneration : a study of lectin-binding structures and desmin in skeletal muscle in vivo and in vitro." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327222.
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Vaughan-Scott, Tarquin. "Serum concentrations of tumour necrosis factor in dogs naturally infected with Babesia Canis and its relation to severity of disease." Diss., University of Pretoria, 2002. http://hdl.handle.net/2263/29287.
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Please read the abstract in the section 00front of this documentCanine babesiosis, caused by the tick-borne protozoan Babesia canis rossi, is an economically important and potentially fatal disease of dogs in South Africa. The host's response to many infectious diseases is mediated (at least in part) by intercellular messengers called cytokines. One of the most important cytokines released is tumour necrosis factor (TNF). A study was designed to measure serum concentrations of TNF in dogs naturally infected with canine babesiosis and to relate TNF concentrations to clinical severity, mortality, rectal temperature and parasitaemia. There was a statistically significant difference in TNF concentrations between groups of differing disease severity, with a general trend of increasing mean 10g(TNF) with increasing severity of disease. A noteworthy finding was that dogs with hypoglycaemia had very high TNF (mean 15.03 nglml compared to a mean of 2.32 nglml for other sick dogs without hypoglycaemia). When TNF values were compared between survival and non-survival groups, there was no significant difference. The rectal temperature of the dogs in this study did not show any statistically significant association with TNF concentrations. When parasitaemia and TNF were examined within groups of infected dogs, there was no significant relationship. However, when the sample size was increased by pooling all infected dogs and treating them as a single group, there was a highly significant positive correlation (p = 0.003) between parasitaemia and serum TNF concentrations. The results ofthis study were encouraging and indicate that canine babesiosis may share a similar pathophysiology with human malaria in terms ofTNF being associated with disease severity. One ofthe most significant findings in this study was the presence ofvery high TNF values in two ofthree dogs with hypoglycaemia. Hypoglycaemia has not been previously recorded in dogs with babesiosis and is a potentially important finding particularly in view ofthe hypoglycaemia associated with malaria in humans. Malarial hypoglycaemia is correlated with a higher mortality in humans, especially in pregnant women and children. If the findings ofthis study can be Vl confinned and expanded, they may lend further support to the use of canine babesiosis as a model for some ofthe problems encountered in human malaria research.
Dissertation (MMed Vet (Med))--University of Pretoria, 2001.
Companion Animal Clinical Studies
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Barbara, Jeffrey A. J. "The mechanism of action of tumour necrosis factor-[alpha] /." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phb229.pdf.
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Mahtani, Kamal Ram. "The post-transcriptional regulation of tumour necrosis factor alpha." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.271639.
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Rayner, Sandra Anne. "Tumour necrosis factor and gene transfer in corneal transplantation." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248143.
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Williams, Llinos. "Expression of tumour necrosis factors during chick lens development." Thesis, Cardiff University, 2008. http://orca.cf.ac.uk/54869/.
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During development of the lens, epithelial cells at the lens equator begin a differentiation process to become secondary fibre cells. The differentiating cells elongate and migrate towards the centre of the lens where they envelop the older, central fibre cells. Differentiation into fibre cells is accompanied by the breakdown of all organelles, such as the mitochondria. All organelle degradation is completed and denucleation occurs at the border of the organelle free zone (OFZ) which contains the central, terminally differentiated, fibre cells. The differentiation pathway is not well characterised, though it is believed to have similarities to an attenuated form of apoptosis supported by the identification of apoptosis related genes, such as TNF, in the lens. This study continues the search for and characterisation of apoptosis related genes expressed during lens development, focusing on TNFs and their extended family. Reverse Transcriptase-(RT-) PCR was carried out, identifying a number of TNF and extended family member genes in the chick lens, expression studies established novel, statistically significant differential expression for TRAF2 and TRAF3. TRAF2 protein expression from western blotting, similar to RT-PCR expression was found to decline as the lens developed. TRAF2 localisation studies showed limited expression in the equatorial region but there was extensive signalling found in the developing iris, a region in the corneal-scleral boundary and some staining was also detected in the ciliary body. TRAF3 protein and RT-PCR expression were similar, with increasing expression as the lens developed. Western blotting identified two bands and subcellular fractionation confirmed different localisation for the two isoforms. Immunofluorescence identified increasing TRAF3 staining in the cortical fibre cells, this staining was found to be similar to proteins that were reported to be involved in lens fibre cell remodelling and maintenance, suggesting a possibly similar role for TRAF3. Following interest in TRAIL as a gene therapy for Posterior Capsule Opacification (PCO) its expression was examined using RT-PCR and Western blotting which showed low, similar levels of expression throughout the stages of lens development studied. Peroxidase staining showed interesting staining in the equatorial epithelial cells and those just beginning to differentiate at the transition zone. Novel nuclear staining was identified at all time points in both epithelial and fibre cells containing nuclei. Characterisation of whole lens culture was undertaken to discover the optimum culture system for the whole chick lens. Of the published research using whole chick lens culture none stated the basic morphology of the developing lens in organ culture, though each lab had their preferred methodology. The characterisation resulted in the preference of E10 chick lenses being grown with vitreous attached in medium containing glucose. Understanding the morphology of lenses in culture will be invaluable when undertaking the functional studies required to clarify the roles in the lens of the newly identified genes, specifically TRAF2 and TRAF3.
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Longin, Ondřej. "Construction of synthetic antibodies against tumour necrosis factor alpha." Thesis, University of Glasgow, 2018. http://theses.gla.ac.uk/39025/.
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This thesis describes efforts towards size reduction of a human tumour necrosis factor alpha (hTNFα)-targeting monoclonal antibody (mAb) infliximab (Remicade®) by means of construction of medium-sized antibody mimics, denoted as synthetic antibodies. The synthetic antibodies constructed by Cu(I) catalyzed azide-alkyne cycloaddition of complementarity determining region (CDR) mimics onto semi-orthogonally protected CTV scaffold derivatives have less than 4% of the molecular weight of the original monoclonal antibody infliximab (144 kDa). The introductory Chapter 1 describes different approaches of targeting hTNFα with small, medium, and large molecules. Furthermore, it explains research undertaken in the Liskamp group which served as a basis for the research reported in this thesis. Chapter 2 describes the development of a synthetic route for the synthesis of semi-orthogonally protected CTV scaffold derivatives. The synthetic route was applied in the synthesis of four semi-orthogonally protected CTV scaffold derivatives with different aqueous solubility-modifying spacer. Chapter 3 focuses on the selection of CDR sequences for mimicry of the mAb infliximab. It further describes their synthesis, cyclisation, and sequential attachment to the CTV scaffold derivatives towards synthesis of synthetic antibodies. Chapter 4 describes an evaluation of the capability of the prepared synthetic antibodies to mimic mAb infliximab. The evaluation was attempted by means of an MTT cell cytotoxicity assay, by affinity determination using isothermal titration calorimetry (ITC), and by surface plasmon resonance (SPR). Chapter 5 focuses on the expression of a recombinant hTNFα using an E. coli expression system. Furthermore, the characterisation of the expressed hTNFα, which was used in the ITC and SPR experiments, is described.
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Borg, Sebastian. "Synthetic bone grafts for treatment of femoral head necrosis." Thesis, Uppsala universitet, Oorganisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-314857.
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Necrosis of the femoral head is a relatively common medical condition that radically decrease the quality of life for the patient. Left untreated it could lead to destruction of the hip joint. A common treatment is using bone autografts, also called bone chips. However, in the last decades synthetic bone grafts have become a very interesting alternative. This thesis had two aims; to evaulate how porous hydroxyapatite grafts with varied pore size could be produced by different size of the porogen and to create two-phase cements which would form pores in situ by using a dissolvable phase of calcium sulfate hemihydrate. The phase composition, morphology, porosity and pore size distribution were characterized with x-ray diffraction, scanning electron microscopy and micro-computed tomography. It was found that hydroxyapatite granules could be produced and it was possible to vary their pore size to some extent by changing the size of the porogen. At physiological temperature, pores were formed in the two-phase cements from one week and onwards.
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González, Aguirre Laura V. "Revascularización en dientes traumatizados, rizogénesis incompleta y necrosis pulpar." Trabajo final de especialización, Universidad Nacional de Cuyo. Facultad de Odontología, 2020. http://bdigital.uncu.edu.ar/15323.
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Necrosis pulpar en niños y adolescentes ya sea por traumatismos o caries puede detener el desarrollo radicular en dientes permanentes jóvenes.
El tratamiento endodóntico en estos elementos con rizogénesis incompleta, con pulpa necrótica con o sin lesión periapical supone una serie de cambios en la clínica, ya que en el tratamiento convencional hay riesgos tales como provocar fractura de las paredes dentinarias y extrusión del material de relleno hacia el periápice durante la condensación dentro del canal radicular. Aunque actualmente contamos con técnicas de apexificación que utilizan hidróxido de calcio intracanal y MTA colocado como tapón apical que ayudan a minimizar estas dificultades, el riesgo de fractura de paredes dentinarias e incluso movilidad dentaria suelen permanecer debido a la baja relación corono radicular. La revascularización pulpar se estudió como terapia alternativa para tratar dientes permanentes jóvenes necróticos con la ventaja de inducir el desarrollo de la raíz , y consiste básicamente en la desinfección química del conducto radicular con solución de irrigación y medicación intracanal seguida de inducción de un coágulo sanguíneo, sello coronal de MTA y colocación de restauración de la corona. La inducción de un coágulo es la técnica más frecuentemente empleada. Sin dejar de tener en cuenta que la necrosis en un diente inmaduro traumatizado presenta un gran compromiso físico de las células del ligamento periodontal y de la papila apical, se torna de suma importancia mantener la integridad y viabilidad de estas células para la reparación de revascularización.
El objetivo de este trabajo es conocer, evaluar y comparar las diferentes técnicas de apexificación para el tratamiento de elementos con rizogénesis incompleta y profundizar conocimientos sobre la técnica de revascularización para poder aplicarlo en nuestra clínica diaria.
La revascularización de la pulpa puede considerarse una alternativa prometedora para los dientes con rizogénesis incompleta, necrosis pulpar, con antecedente de traumatismo dentario.Fil: González Aguirre, Laura V.. Universidad Nacional de Cuyo. Facultad de Odontología.
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Willingham, Stephen B. Ting Jenny P. Y. "Microbial pathogen-induced necrosis mediated by NLRP3 and ASC." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1712.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Sep. 16, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Curriculum in Genetics & Molecular Biology." Discipline: Genetics and Molecular Biology; Department/School: Medicine.
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Watts, Alan D. "The biological role of transmembrane tumour necrosis factor [alpha]." Thesis, The University of Sydney, 1998. https://hdl.handle.net/2123/27668.
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Tumour necrosis factor (TNF) exists in two physiological forms. One is
a soluble polypeptide of 17 kDa, and the other a type II integral membrane
protein of 26 kDa designated transmembrane TNF. Soluble TNF is derived
from the transmembrane form by proteolytic processing. The soluble TNF
molecule exerts potent cytotoxic activity against certain types of cancer cells,
and plays a critical role in the functioning of the immune and inflammatory
system. The transmembrane TNF molecule shares many of the properties of
the soluble form in vitro, but its function in the immune system is not as clearly
defined as for the sTNF form. In this thesis the biological role of
transmembrane TNF was investigated.
The synthesis and expression of both soluble TNF and transmembrane
TNF forms was examined in macrophage cells stimulated with LPS. Basic
parameters for the production of transmembrane TNF were established to
enable further analysis of its function.
Using a hydroxamic acid-based inhibitor of TNF processing it was
possible to obtain macrophage cells that expressed transmembrane TNF, but
not soluble TNF; This enabled the investigation of transmembrane TNF free
from the complicating effects of soluble TNF. It was found that inhibition of
TNF processing in this way caused an accumulation of transmembrane TNF
on the macrophage cells surface 5.1-7.5-fold greater than in cells not treated
with the hydroxamic acid-based inhibitor. This corresponded to a 6.4-fold
increase in TNF-mediated cytotoxicity of macrophage cells towards cells
sensitive to transmembrane TNF.
By radiolabelling macrophages, and using a specialised
immunoprecipitation method, it was demonstrated that a soluble form of one of
the TNF receptors (sTNFFi) binds transmembrane TNF. The consequence of
this binding was neutralisation of transmembrane TNF-mediated cytotoxicity,
but not inhibition of proteolytic processing of transmembrane TNF to release
soluble TNF.
The possibility that transmembrane TNF is capable of transducing a
signal upon ligation with sTNFR was investigated. A broad range of cellular
parameters were measured to see whether sTNFFi treatment of macrophages
expressing transmembrane TNF induced a biochemical/physiochemical
change. It was found that sTNFR caused a large increase (~200%) in
ix
intracellular calcium levels after 15 min treatment. This is the first direct
evidence that transmembrane TNF is capable of acting like a receptor.
The composition of the predicted amino acid sequence of
transmembrane TNF was closely examined to determine the presence of
features important for both structure and intracellular signalling. A model is
presented in Chapter 6 which outlines in diagrammatic form likely structural
features of transmembrane TNF. The molecule is predicted to possess a
region of cytoplasmic alpha-helices corresponding to a highly conserved
domain of the sequence. The structure of transmembrane TNF is consistent
with that of a transmembrane receptor, capable of transducing signals initiated
by ligation with an extracellular ligand.
The comparison of predicted amino acid sequences of transmembrane
TNF from different mammalian species revealed the presence of a conserved
casein kinase | site. This site was also found to be present in most members
of the TNF ligand family. Using orthophosphate labelling, it was shown that
mouse transmembrane TNF is phosphorylated in macrophages. Ligation of
sTNFR with transmembrane TNF induced de-phosphorylation of mTNF. This
de-phosphorylation could be prevented by pre-incubation of the cells with
serine phosphatase inhibitors. A selective inhibitor of casein kinase |
dramatically reduced the phosphorylation of transmembrane TNF produced
by macrophages. In addition, a recombinant form of casein kinase l
phosphorylated transmembrane TNF in vitro on the site naturally
phosphorylated by the endogenous kinase in vivo.
The evidence presented in this study supports an entirely new role for
transmembrane TNF, one in which the molecule is capable of acting like a
transmembrane receptor, with the ligand being sTNFR. This phenomenon is
known as "reverse signalling", and has been shown by other researchers to
occur in the majority of members of the TNF ligand family. Implications of
mTNF "reverse signalling" are relevant to the treatment of human diseases in
which sTNFRs are currently being assessed in clinical trials.
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Valbuena-Gonzalo, Carlos. "Identifying Genetic Causes of Hybrid Necrosis in Arrabidopsis lyrata." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-163444.
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Deleterious gene interactions due to accumulation of individual genetic variations between different lineages are a cause of population diversification by creating reproductive barriers that ultimately lead to differentiation of species. One type of deleterious interactions is called “hybrid necrosis”, in which epistatic interactions between some plant immunity genes (usually very variable) cause autoimmunities that produce a necrotic and dwarf phenotype. Hybrid necrosis has been widely studied in several plant species, such as Arabidopsis thaliana and many gene interactions were found for that plant. This study tests the applicability of these results on a close relative, A. lyrata, by crossing individuals from different populations and genotyping F2 progeny with polymorphic markers close to homologous sequences to those involved in hybrid necrosis in A. thaliana. Results suggest the possibility of a homologous gene to DM8 or DM9 in chromosome 7 to be involved in formation of hybrid necrosis.
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Atkinson, Yvelle Hope. "Regulation of neutrophil functions by tumor necrosis factor-alpha /." Title page, contents and summary only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09pha878.pdf.
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Ferreira, Juliana. ""Análise da necrose em tecidos normais fotossensibilizados pós terapia fotodinâmica - estudo in vivo"." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/17/17143/tde-17052004-144509/.
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O conceito de PDT é a fotoindução da citotoxicidade das células proliferativas envolvendo um agente fotossensibilizador, uma fonte de luz e oxigênio. Apesar de ser uma terapia eficiente no tratamento de várias neoplasias, a PDT apresenta algumas limitações dentre as quais a não seletividade em células do tecido hepático.O presente trabalho avaliou a correlação entre penetração luminosa e necrose, assim como a extensão da mesma em função da concentração do fotossensibilizador utilizado (Photogem) e de três diferentes doses de energia. A transição do epitélio necrosado e do epitélio sadio, foi realizada após a irradiação de fígados normais de ratos previamente fotossensibilizados. O acúmulo do Photogem, administrado via endovenosa, no fígado, foi investigado através da espectroscopia de fluorescência. As fontes de luz utilizadas para irradiação foram um laser de diodo de 630nm e um dispositivo a base de LEDs (diodos emissores de luz). Observamos que o tecido hepático normal, fotossensibilizado, apresenta suas características ópticas alteradas, evidenciadas nos estudos de penetração da luz e alteração térmica durante a irradiação, refletindo na profundidade da necrose. Verificamos que a presença do FS no tecido alvo diminui a penetração da luz, levando a um aumento da temperatura, devido à grande quantidade de energia absorvida pelo FS, a qual é dissipada na forma de calor. Notamos uma abrupta delineação da necrose correspondendo à queda de intensidade luminosa no tecido iluminado. A profundidade de necrose obtida com o uso do LED apresentou uma pequena variação, devido à linha espectral do mesmo ser mais larga, quando comparado ao laser. Histologicamente o tecido hepático e irradiado apresentou necrose coagulativa, infiltrado inflamatório neutrofílico e necrose da veia centrolobular em todos os grupos experimentais; também observamos uma nítida delimitação entre o tecido epitelial normal e o tecido epitelial fotossensibilizado. Estes resultados serão importantes para o desenvolvimento de estratégias para um possível protocolo para aplicação da PDT em tumores malignos hepáticos.The PDT concept is the photo induction of the citotoxicity of proliferating cells involving a photosensitizer agent, a light source and oxygen. Despite being an efficient therapy on the treatment of several neoplasias, PDT presents some restrictions including the non-selectivity in hepatic tissue cells. This work evaluated the correlation between light penetration and necrosis, as well as the extension of such as function of the concentration of the photosensitizer used (Photogem) and three different doses of energy. The necrosed epithelium and healthy epithelium transition was performed after the irradiation of normal livers of previously photosensitized rats. The Photogem accumulation, intravenously administrated, on the liver was investigated through fluorescence spectroscopy. The light sources used for irradiation were: diode laser operating at 630 nm and a LEDs (Light Emitting Diode) device. We observe that the photosensitized normal hepatic tissue presents its optical characteristics altered, which was previously evidenced on the studies of light penetration and thermal alteration during the irradiation, altering the necrosis depth. We checked that the photosensitizer presence on the target tissue decreases the light penetration leading to a temperature increase, due to a large amount of energy absorbed by the photosensitizer, which is dissipated by means of heat. We noticed an abrupt necrosis delineation corresponding to the drop of the light intensity on the irradiated tissue. When the LED was used, the necrosis depth presented little variation, due to its spectral line being larger when compared to the lasers spectral line. Histological, the irradiated hepatic tissue presented coagulative necrosis, inflammatory infiltration neutrophilic and centrilobular vein necrosis in all experimental groups, we also observed a clear delimitation between normal epithelial tissue and photosensitized tissue. These results will be important to the development of strategies for a possible protocol for the PDT application on hepatic malign tumors.
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Freitas, Vanessa Santana. "Investigação do efeito citotóxico do extrato metanólico de Bixa orellana L sobre células astrocíticas tumorais e astrócitos in vitro." reponame:Repositório Institucional da FIOCRUZ, 2011. https://www.arca.fiocruz.br/handle/icict/4320.
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Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-09-04T17:32:14Z
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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil
Investigar a capacidade antitumoral do extrato metanólico de Bixa orellana em células neoplásicas de Glioblastoma multiforme (GL-15) e Glioma murino (C6), sem toxicidadade para as células astrocitárias normais in vitro. Métodos e resultados: Caracterização do extrato por espectrofotometria por absorção de luz visível apresentou picos em 286, 363 e 435 nm. Determinou-se os teores de bixina e compostos fenólicos – 0,17 mg/mg e 0,05 mg por equivalência de pirogalol/mg de extrato seco, respectivamente. A citoxicidade foi investigada pelo teste de Brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium. A Mínima Concentração Citotóxica (MCC) para GL-15 foi 180 e 80 μg/mL para C6, para astrócitos foi 240 μg/mL, após 48 horas de tratamento. O teste de exclusão com azul tripan confirmou a EC50 para GL-15 após 24 horas. A análise morfológica foi realizada por microscopia de contrataste de fase e fluorescência. Comprovou-se a diminuição de células neoplásicas e alterações celulares na MCC em astrócitos. A capacidade de fluorescência foi comprovada em GL-15. A citotoxicidade não depletou GSH. Investigou-se alterações de ciclo celular e morte celular por citometria de fluxo. Alterações de ciclo celular não foram evidenciadas. O tipo de morte celular foi investigado com marcação para anexina V e Iodeto de Propídio comprovou morte por necrose em GL-15 e por apoptose tardia em C6, os astrócitos apresentaram valores pequenos de morte por apoptose tardia e necrose. Conclusão: Os dados indicam um potencial antitumoral das substâncias presentes neste extrato para células neoplásicas sem ser tóxico para células normais.
This work investigated the hypothesis that the methanol extract of Bixa orellana decreases the viability of GL-15 and C6 cells, without being toxic to normal astrocytes in vitro. Methods: The methanol extract of B. orellana seeds was obtained and characterized by UV-Vis spectrophotometry. The cytotoxic effects were assayed in vitro using the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide method. The cell morphology was investigated by phase contrast and fluorescence microscopy. The depletion of reduced glutathione (GSH) was observed by fluorescence microscopy. The effects on cell cycle and the mode of cell death was studied by flow cytometry. Results: The contents of bixin and phenol were 0.17 mg/mg of extract and 0.05 mg of pyrogallol equivalent/mg of extract, respectively. Three peaks were observed at 286, 363, and 435 nm. The extract killed cells in a dose-dependent manner. The minimum cytotoxic concentrations in the two tumoral cells (GL-15 and C6) were respectively: 180 μg/mL and 80 μg/mL, meanwhile in astrocytes it was 240 μg/mL after 48 hours. The trypan blue assay confirmed the cytotoxic effect to GL-15 cells. Morphological degeneration of treated glioma cells was observed. The same was observed with astrocytes, but at a higher concentration. Treated cells became fluorescent, probably due to incorporation of bixin. The treatment neither depleted GSH, nor interfered on the cell cycle. The main kind of cell death was necrosis. Conclusions: Compounds present in B. orellana seeds are potentially cytotoxic to glioma cells, meanwhile primary astrocytes are more resistant.
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Langton, Amy Jean. "The role of TRUSS in TNFα-TNFRI signalling : implications for inflammatory lung diseases." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608019.
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Bond, Arden Lenore. "The production and characterization of a putative anti-idiotypic antibody to tumor necrosis factor-[alpha] /." This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-05042010-020132/.
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Saccon, Cassia Maria Toledo. "Alterações nas vias proteoliticas endogenas causados pela peçonha de Bothrops Jararacussu em musculo esqueletico." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/314699.
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Orientadores: Stephen Hyslop, Maria Cristina Cintra Gomes MarcondesDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O acidente causado por serpentes botrópicas produz intensa hemorragia e mionecrose local, com perda e degradação tecidual. Neste trabalho, investigamos as atividades do proteossomo (via seletiva da degradação protéica), catepsinas (proteases lisossomais) e calpaína (protease neutra dependente de cálcio) no envenenamento causado por peçonha de Bothrops jararacussu. Também analisamos a capacidade do MG-132, inibidor proteossômico, em atenuar os efeitos causados pela peçonha. A peçonha (25 µg e 75 µg) foi injetada em músculo gastrocnêmio de camundongos, que foram sacrificados 1, 3, 6, 12, 24, 48, 72 h e 7, 14, 21, 28 dias após o envenenamento. Os músculos tratados e contralaterais foram retirados e processados para histologia e para ensaios fluorimétricos e colorimétricos das enzimas e o sangue foi coletado para quantificação da creatina quinase (CK, indicador da mionecrose). A peçonha de B. jararacussu causou hemorragia e mionecrose (fase 1, até 6 h a 12 h pós-envenenamento - p.e.), a presença de infiltrado inflamatório e desencadeou a formação de miotubos e mioblastos (fase 2, de 12 h a 72 h p.e.) e o aparecimento de células regenerativas com maior deposição de colágeno ao redor dessas células (fase 3, 7-28 dias p.e.). De modo geral, as alterações mais marcantes ocorreram com a dose maior da peçonha. O dano tecidual agudo foi confirmado pelo aumento nos níveis plasmáticos de CK entre 1 h e 6 h p.e., com pico em 3 h. Houve redução na concentração de aminoácidos livres do músculo durante as primeiras 24 h, seguida por retorno a níveis normais. Também houve redução significativa na atividade proteossomal (até 48 h) nos músculos envenenados seguida por recuperação e aumento significativo em alguns períodos da regeneração. Nesses períodos de regeneração, houve aumento da expressão das subunidades 20Sa e 11S do proteossomo, principalmente com a dose maior da peçonha. O inibidor proteossômico diminuiu a atividade quimiotripsina e o número de células regenerativas, mas esses efeitos também foram observados no grupo que recebeu apenas o veículo do inibidor (DMSO). A calpaína foi ativada nas primeiras 6 h após o envenenamento somente com a dose maior da peçonha. As catepsinas (B e H) exibiram ativação significativa no período de regeneração (de 48 h até 28 dias) nas duas doses aplicadas. Esses resultados indicam que a peçonha de B. jararacussu afetou diferencialmente as vias proteolíticas estudadas. É possível que a calpaína esteja envolvida na fase 1 do dano tecidual e que as catepsinas estejam relacionadas à presença de infiltrado inflamatório (fase 2) ou à regeneração (fase 3). O proteossomo parece não estar relacionado à fase aguda de degradação tecidual, mas pode estar envolvido na regeneração muscular embora isso ainda precise ser confirmado
Abstract: Bites by Bothrops snakes produce intense local hemorrhage and myonecrosis, often with extensive tissue degradation. In this work, we investigated the activities of the proteasome (pathway for selective protein degradation), cathepsins (lysosomal proteinases) and calpains (neutral, calcium-dependent proteinases) in envenoming by Bothrops jararacussu. We also examined the ability of MG-132, a proteasome inhibitor, to attenuate the venom-induced effects. Mice were injected with venom (25 µg or 75 µg) in the left gastrocnemius muscle and then killed 1, 3, 6, 12, 24, 48, 72 h and 7, 14, 21 and 28 days post-venom. The venom-injected and contralateral muscles were removed and processed for histological analysis or enzymatic assays using fluorimetric or colorimetric substrates. Blood was also collected for the quantification of plasma creatine kinase (CK, an indicator of myonecrosis). Bothrops jararacussu venom caused hemorrhage and necrosis (phase 1, up to 6-12 h post-venom), an inflammatory cell infiltrate and it generated the formation of myotubes and myoblasts (phase 2, 12-72 h post-venom), and the appearance of regenerative cells with increase of collagen deposition around these cells (phase 3, 7-28 days post-venom). The alterations were generally more marked with the higher dose of venom. The early tissue damage was confirmed by an increase in plasma CK levels 1-6 h post-venom, with a peak at 3 h. The muscle content of free amino acids decreased during the first 24 h, followed by a return to normal levels. Proteasomal activity was significantly inhibited for up to 48 h post-venom, followed by recuperation and a significant increase during muscle regeneration. During regeneration, there was also an increase in the expression of the 20Sa and 11S proteasomal subunits, mainly with the highest dose of venom. The proteasomal inhibitor reduced the chymotrypsin activity of the proteasome and the number of regenerating cells, but these effects were also seen in mice that received vehicle (DMSO) alone. The highest dose of venom caused an increase in calpain activity in the first 6 h whereas both of the venom doses significantly increased the activities of cathepsins B and H during the regeneration phase (48 h¿28 days post-venom). These results indicate that B. jararacussu venom differentially affects the proteolytic activities studied. Calpain may be involved in phase 1 of tissue damage and cathepsin activity may be related to the presence of an inflammatory infiltrate (phase 2) and/or regeneration (phase 3). The lack of proteasomal activation in the early stages of envenoming suggests that this proteolytic pathway is not involved in early venom-induced muscle damage. However, the involvement of proteasomal activity during muscle regeneration remains to be established.
Mestrado
Bioquimica
Mestre em Biologia Funcional e Molecular
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Higashi, Rosemeire Rosa. "Estudo da osteonecrose no processo de usinagem da cabeça do fêmur utilizando um dispositivo mecânico de furação." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18146/tde-16122014-173014/.
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A utilização de implantes cirúrgicos para artroplastia de quadril com prótese de recapeamento da cabeça femoral como substituto ósseo é um procedimento que tem sido realizado em 35% dos casos de Osteoartrose nos EUA. Entretanto, o atrito da broca e o aumento da temperatura durante a usinagem da cabeça femoral são responsáveis pelo possível aquecimento do tecido ósseo, podendo provocar a necrose óssea térmica. Neste sentido, o desenvolvimento de novos ferramentais e metodologias para minimizar os danos térmicos do atrito torna-se importante. Diante disso, o presente estudo teve como objetivo verificar se há a ocorrência de necrose óssea em um procedimento de furação óssea utilizando o dispositivo EQUITRON; Mod.ES 2200, desenvolvido no LTC-EESC-USP. Para tal, utilizamos 4 amostras de costela bovina removidas após a morte do animal, que foram furadas com broca de aço inoxidável (HSS-SKF), de 8 milímetros, sem irrigação externa. As amostras foram furadas com rotações de 100, 1000, 1200 e 2500 RPM, aferidas por tacômetro foto/contato digital da marca MINIPA, MDT-2238, e com avanço controlado de 80 mm/min (dispositivo da marca-EQUITRON; MOD.ES 2200; RPM 2800; Potência 0,30; Torque 1,6 Nm). Foram mensuradas as temperaturas iniciais da broca e da amostra e a final da amostra com termômetro digital, marca-MEDISANA®. Após a furação foram confeccionadas lâminas histológicas (HE) do tecido ósseo, preparadas de acordo com a metodologia apropriada, para posterior qualificação e quantificação da ocorrência de necrose óssea térmica através de imagens captadas por microscopia óptica (Olympus BX 41TF - Made Japan) utilizando-se o programa Motic Images Plus 2.0 para a captura das imagens. Os valores de temperaturas aferidos na amostra após a furação apresentaram relação positiva com a RPM utilizada, isto é, quanto maior a rotação, maior foi a temperatura observada. Apenas a amostra furada a 2500 RPM ultrapassou a temperatura de referencia para a gênese da osteonecrose térmica, que é de 47ºC. As análises histológicas apresentaram uma baixa predominância de células picnóticas e lacunas, sugerindo menor dano tecidual. Os resultados obtidos no presente estudo sugerem que o dispositivo (furadeira) desenvolvido no LTC-EESC-USP para a realização das furações nas amostras ósseas em testes de bancada foi eficiente em minimizar a ocorrência de necrose óssea térmica, até mesmo em condições de temperatura acima do limite fisiológico aceitável.The utilization of surgical implants for hip arthroplasty with a resurfacing prosthesis of the femoral head as a bone substitute have been conducted in 35% of osteoarthrosis cases in the USA. However, the friction of the drill and the increase in the temperature during the machining of the femoral head can possibly heat the bony tissue and provoke a thermal bone necrosis. The development of new tools and methodologies for minimizing the thermal damage of the friction has become fundamental. The present study analyzes the occurrence of bone necrosis in a procedure of bone drilling that uses an EQUITRON device, Mod. ES 2200, developed at the LTC-EESC-USP. Four samples of bovine ribs removed after the death of the animal were used for the tests. They were drilled by an 8mm stainless-steel drill (HSS-SKF) with no external irrigation, at 100, 1000, 1200 and 2500 RPM calibrated by a MINIPA, MDT-2238 digital photo/contact tachometer and whose 80mm/min. advance (EQUITORN device; MOD.ES 2200; RPM 2800; 0.30 Potency and 1,6Nm torque) was controlled. The initial temperatures of the drill and the sample and the final temperature of the sample were measured by a MEDISANA digital thermometer. After drilling, histological blades (HE) were produced from the bony tissue and prepared according to the adequate methodology for further qualification and quantification of the occurrence of thermal bone necrosis through images captured by optical microscopy (Olympus BX 41TF - made in Japan) and Motic Images Plus 2.0 program. The values of the temperatures measured in the sample after drilling showed a positive relation with the RPM utilized, i.e., the faster the rotation, the higher the temperature. Only the sample drilled at 2500RPM exceeded the reference temperature (47ºC) for the genesis of the thermal osteonecrosis. The histological analyses revealed a low predominance of picnotic cells and gaps, which suggest minor tissue damage. The results show the device (drilling machine) developed at the LTC-EESC-USP for the drilling in the bone samples in workbench tests is efficient to minimize the occurrence of thermal bone necrosis, even at temperatures above the physiological acceptable limit.
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Maioli, Marcos Antonio. "Papel da mitocôndria na citoxicidade induzida pela abamectina em hepatócitos isolados de rato /." Araçatuba, 2012. http://hdl.handle.net/11449/92104.
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Orientador: Fabio Ermínio MingattoBanca: Cézar Rangel Pestana
Banca: Guilherme de Paula Nogueira
Resumo: Abamectina (ABA), pertencente à família das avermectinas é utilizada mundialmente como parasiticida, porém a intoxicação por ABA pode prejudicar o funcionamento hepático. Existem substâncias que quando metabolizadas exercem atividade tóxica, afetando a função de importantes organelas como a mitocôndria, responsável por uma variedade de processos bioquímicos, como a produção de ATP e morte celular. O objetivo desse estudo foi caracterizar o mecanismo de toxicidade da ABA em hepatócitos isolados de ratos e avaliar se esse efeito é dependente do seu metabolismo. A toxicidade da ABA foi avaliada monitorando o consumo de oxigênio e o potencial de membrana mitocondrial, concentração intracelular de ATP, viabilidade celular por meio da liberação das enzimas ALT e AST, homeostase intracelular Ca2+, liberação de citocromo c, atividade da caspase 3 e morte celular por necrose. A ABA reduz a respiração celular, tanto em células energizadas com glutamato mais malato quanto com succinato. O metabolismo da ABA reduz sua toxicidade, uma vez que hepatócitos previamente incubados com proadifen apresentam maior sensibilidade ao composto, sendo isto observado pelo rápido decréscimo da formação do potencial de membrana mitocondrial acompanhado pelas reduções das concentrações de ATP, viabilidade celular e ruptura da homeostase intracelular de Ca2+ com estabelecimento de necrose. Nossos resultados indicam que a toxicidade da ABA diminui com a sua biotransformação, e sua ação tóxica está relacionada com a inibição da atividade mitocondrial, levando à diminuição da síntese de ATP seguida pela morte da célula
Abstract: Abamectin (ABA), which belongs to the family of avermectinas, used worldwide as a parasiticide, but the ABA poisoning can impair the functioning liver. There are substances which exert toxic activity when metabolized, thus affecting the function of important organelles such as mitochondria, responsible for a variety of biochemical processes, such as ATP production and cell death. The aim of this study was to characterize the mechanism of toxicity of ABA in isolated rat hepatocytes and to evaluate whether this effect is dependent on your metabolism. The toxicity of ABA was assessed by monitoring oxygen consumption and mitochondrial membrane potential, intracellular concentration of ATP, cell viability by releasing enzymes ALT and AST, homeostasis intracellular Ca2+, release of cytochrome c, activity of caspase 3 and cell death necrosis. The ABA reduces cellular respiration, both in cells energized with glutamate and succinate over malate. The metabolism of ABA reduces its toxicity, since hepatocytes pre-incubated with proadifen are more sensitive to the compound, this being observed by the formation of rapidly decreasing mitochondrial membrane potential accompanied by reductions in concentrations of ATP, cell viability and rupture of the intracellular homeostasis Ca2+ with the establishment of necrosis. Our results indicate that the toxicity decreases as the ABA its biotransformed and its toxic action is related to the inhibition of mitochondrial activity, leading to decreased synthesis of ATP followed by cell death
Mestre
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Dias, Kássia de Carvalho. "Efeito das toxinas microbianas provenientes de biofilme simples ou misto de Staphylococcus aureus e Candida albicans sobre monoculturas ou culturas 3D de células da mucosa oral /." Araraquara, 2016. http://hdl.handle.net/11449/148693.
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Orientador: Carlos Eduardo VerganiResumo: Esta presente tese foi dividida em quatro estudos que tiveram como objetivos. 1. Validar um protocolo e comparar o efeito dos tampões RPMI/MOPS e RPMI/HEPES no desenvolvimento de biofilmes e na viabilidade celular de queratinócitos (NOK-si e HaCat); 2. Comparar o dano celular e a resposta inflamatória induzidos pelos metabólitos de biofilmes simples e misto de Staphylococcus aureus e Candida albicans; 3. Avaliar o tipo de morte celular (apoptose vs. necrose) e a ativação de caspases relacionadas aos metabólitos desses biofilmes e 4. Caracterizar um tecido oral reconstituído e analisar o dano tecidual causado pelo sobrenadante e biofilme propriamente dito desses microrganismos. No estudo 1, a viabilidade celular foi avaliada pelo método colorimétrico do MTT e por imagens da cultura após 12 horas em contato com os meios de cultura. Ambos os tampões permitiram similar crescimento do biofilme. Efeito citotóxico do MOPS foi verificado após 6 horas de crescimento de NOK-si e HaCat. Houve preservação da viabilidade e morfologia quando as células foram expostas a RPMI/HEPES. Conclui-se que RPMI/HEPES pode ser utilizado como um meio tamponamente viável para estudos que avaliam o efeito do biofilme em cultura de queratinócitos ao longo do tempo. No estudo 2, o sobrenadante dos biofilmes de 36 h de C. albicans e S. aureus, isolados ou em associação, foi colocado em contato com NOK-si, HaCat e macrófagos (J774A.1). O dano celular foi avaliado por meio de ensaios de viabilidade celular ... (Resumo completo, clicar acesso eletrônico abaixo)
The present thesis was divided into four studies with the following objectives. 1. Validate a protocol and compare the effect of RPMI/MOPS and RPMI/HEPES buffers on the development of biofilms and keratinocyte cell viability (NOK-si and HaCat); 2. Compare the cellular damage and the inflammatory response induced by the metabolites of simple and mixed biofilms of Staphylococcus aureus and Candida albicans; 3. Evaluate the type of cell death (apoptosis vs. necrosis) and the activation of caspases related to the metabolites of these biofilms and 4. Characterize the reconstituted oral tissue and analyze the tissue damage caused by the supernatant and biofilm of these microorganisms. In study 1, cell viability was evaluated by the MTT colorimetric method and by culture images after 12 hours in contact with the culture media. Both buffers permitted similar biofilm growth. The cytotoxic effect of MOPS was observed after six hours of NOK-si and HaCat growth. There was preservation of viability and morphology when cells were exposed to RPMI/HEPES. It was concluded that RPMI/HEPES can be used as a buffering medium for studies evaluating the effect of biofilm on keratinocyte culture over time. In study 2, the supernatant of the 36-hour biofilms of C. albicans and S. aureus, isolated or in combination, was placed in contact with NOK-si, HaCat and macrophages (J774A.1). Cell damage was assessed by cell viability assays (MTT) and LDH enzyme release. Cytokine production was analyzed by the ELISA method and evaluation of the type of cell death by the staining of the apoptotic cells with annexin V and the necrotic cells with propidium iodide. The mixed biofilm and biofilm of C. albicans were more cytotoxic, and the mixed biofilm caused greater cellular damage through the release of the LDH enzyme. S. aureus biofilm metabolites stimulated greater production of NO, IL-6 and TNF-α... (Complete abstract electronic access below)
Doutor
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Han, Jiahuai. "Study of the regulation of cachectin/tumor necrosis factor expression." Doctoral thesis, Universite Libre de Bruxelles, 1990. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/213139.
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Jersmann, Hubertus Paul Anton. "Bacterial lipopolysaccharide and tumour necrosis factor- alpha synergism in inflammation." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phj56.pdf.
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Bibliography: leaves 152-194. This thesis has contributed to the knowledge of how the bacteriokine-cytokine network operates by demonstrating how two major proinflammatory mediators interact in modulating the inflammatory response. Furthermore the discovery of CD14 expression on endothelial cells not only provides greater insight in the pathogenesis of bacterial infection, sepsis and perhaps atherosclerosis, it is also likely to influence the future development of new treatment strategies for those conditions.
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Hel, Zdenek. "Posttranscriptional regulation of tumor necrosis factor-Ã production in macrophages." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0010/NQ36980.pdf.
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Mustapha, Shareef. "Signaling pathways of tumor necrosis factor à in ventricular myocytes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ41751.pdf.
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Morris, Alison. "The role of tumour necrosis factor alpha (TNFđ) in obesity /." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phm8748.pdf.
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Hel, Zdenĕk. "Posttranscriptional regulation of tumor necrosis factor-a production in macrophages." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34642.
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The production of tumor necrosis factor-alpha (TNF-alpha), a key cytokine regulator of an early immune response and a central mediator of the deleterious effects of systemic inflammatory response syndrome, is regulated at both the transcriptional and posttranscriptional level. The 3' -untranslated region (3'-UTR) of TNF-alpha mRNA contains sequences that confer its translational repression in quiescent cells and are responsible for the induction of TNF-alpha production following macrophage contact with bacterial lipopolysaccharide, live bacteria, or viruses.We demonstrate that two distinct regions, located in a part of the 3 '-UTR of murine TNF-alpha mRNA previously shown to play a crucial role in the regulation of the stability and translatability, interact with macrophage nuclear and cytoplasmic proteins. The first protein binding region is located inside the AU-rich sequence 424 bp downstream of the end of the coding sequence, while the second protein binding region contains a single AUAUUUAU motif and is located 147 bp downstream of the first region. Six detectable protein species interact with the first protein binding region and seven proteins interact with the second binding region. Some of the RNA binding proteins mutually compete for the binding to both regions. TNF-alpha derived cRNA probes form complexes with proteins differentially distributed among the nuclear, cytosolic and particulate fractions of murine macrophages. Three of the TNF-alpha mRNA binding complexes cosediment in the polyribosomal fraction. The stimulation of macrophages with LPS, interferon-gamma, PMA or their combination significantly increases the stability and translational efficiency of TNF-alpha mRNA, yet does not alter the RNA binding activity nor the localization of TNF-alpha mRNA binding proteins, suggesting that regulation of gene expression by RNA-binding proteins may involve other mechanisms, such as posttranslational modification of these proteins or proteins interacting with them rather than global alteration of their amounts in particular cell compartements. The GA dinucleotide insertion inside the first protein binding region, found in NZW and several other strains of mice and associated with lowered ability of peritoneal macrophages to produce TNF-alpha, alters the formation of RNA-protein complexes, supporting their role in the posttranscriptional regulation of TNF-alpha production. Two candidate TNF-alpha mRNA binding proteins were cloned by direct screening of cDNA protein expression library using modified northwestern
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Bain, Nicola. "Understanding host-pathogen interactions of infectious pancreatic necrosis virus (IPNV)." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=158418.
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Sequencing and phylogenetic analysis was used to characterise a number of Scottish IPNV isolates. The majority of isolates from Scotland were genetically closely related to the Sp strain of IPNV. There appears to be a link between the IPN status of a farm and the presence of IPNV in the environment but this is short lived as IPNV does not typically persist in natural reservoirs at sufficiently high levels to allow re-infection to occur. Real-time PCR was used to study the expression of a subset of immune relevant genes following IPNV challenges by a natural (co-habitation) and unnatural (i.p.) route. Differences were observed between the two challenge routes which may reflect orientation towards a Th1 or Th2/regulatory response in i.p. and cohabiting infected fish respectively. These results may give us a better understanding of immune regulation in Atlantic salmon, and may lead to improved vaccine development. Real-time PCR was used to analyse the expression of the two Atlantic salmon IRF-1 isoforms, the results show that the IRF-1 gene is induced in response to IPNV infection in kidney tissue and in ASK cells but in macrophages no significant difference in expression was observed. SSH identified several candidate genes that may be part of a protection mechanism in Atlantic salmon important for controlling viral replication and the pathogenic effects of IPNV. Genes that were found to be significantly up-regulated belong functionally to the following groups of processes: proteolysis immune and stress response, transcription/replication, translation, protein transport/protein interactions and the metabolism. This is the first report identifying Vig-2 as being upregulated by IPNV.
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Dunlop, J. "Modulation of human neutrophil apoptosis by tumour necrosis factor-alpha." Thesis, University of Edinburgh, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.649799.
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Many pro-inflammatory mediators have been demonstrated to inhibit neutrophil apoptosis in vitro, suggesting that such agents act not only in a priming or secretagogue capacity but also increase neutrophil functional longevity by delaying apoptosis. We have examined whether this hypothesis holds true for all neutrophil priming agents, in particular TNFα, a potent neutrophil priming agent which has been variably reported to either induce, delay, or have no effect on the rate of constitutive neutrophil apoptosis. We have shown that following a 20 hr incubation the rate of neutrophil apoptosis is inhibited by TNFα, however more detailed analysis demonstrated the ability of this cytokine to promote apoptosis in a subpopulation of cells at earlier (2-8 hr) times. FMLP, PAF, inositol hexakisphosphate, LPS, LTB and GM-CSF which represent a broad spectrum of alternative neutrophil priming and activating agents all inhibited apoptosis at 6 and 20 hr. The early pro-apoptotic effect of TNFα was confirmed by DNA fragmentation and propidium iodide binding and shown to be concentration-dependent with a near-identical EC50 value (2.8 ng/ml) to that observed for TNFα-priming of fMLP-stimulated superoxide anion generation. Moreover, the early cytocidal effect of this cytokine was detectable within 2 hr, abolished by TNFα neutralizing antibody, and was not associated with any change in cell viability or recovery. Of note, TNFα-stimulated apoptosis was abolished by pre-incubation of neutrophils with selective blocking antibodies to both the TNFR55 (which contains the classical death-domain sequence and is entirely responsible for the TNFα priming effect in suspension neutrophils) and TNFR75 receptor subtypes. Moreover, the TNFR55-selective mutants (E146K, R23W-S86T) induced neutrophil apoptosis but with a potency 14-fold lower than wild type TNFα while the TNFR75-selective mutant (D143F) did not induce apoptosis. These data indicate that TNFα has the ability apparently unique to this priming agent to induce apoptosis in human neutrophils at early time points via a mechanism whereby the TNFR75 facilitates and permits TNFR55-mediated induction of cell death.
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Knott, Rachel M. "The persistence of infectious pancreatic necrosis virus in Atlantic salmon." Thesis, University of Aberdeen, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330104.
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The persistence of infectious pancreatic necrosis virus (IPNV) in Atlantic salmon was examined with particular emphasis on the association of IPNV with leucocytes. Atlantic salmon were infected with IPNV via the water and via the feed. Despite relatively low mortalities, a high prevalence of IPNV was demonstrated particularly when the virus was introduced via the water. No virus-specific pathology or reduction in the growth performance of infected populations was evident. The conditions for the stimulation of Atlantic salmon leucocytes with the mitogen, phytohemagglutinin (PHA) were optimised and utilized in a co-stimulation assay. In this assay, leucocytes were infected with IPNV and simultaneously stimulated with PHA. It was demonstrated that the ability of IPNV to infect and replicate in leucocytes was enhanced when the cells were stimulated with mitogen. DNA synthesis was inhibited in the infected leucocytes. The inhibition was dependent upon the presence of infectious virus; inactivated virus failed to inhibit DNA synthesis. Three groups of salmon were examined to investigate the in vivo relationship of IPNV with leucocytes. Group A were the control group. IPNV was not isolated from these fish and the leucocytes responded to stimulation with PHA. Group B were experimentally infected IPNV carriers; virus was isolated from 6% of the fish using standard diagnostic methods but was not isolated from the supernatants of leucocyte cultures. The leucocytes of most fish responded to PHA stimulation. Neutralising antibody titres were variable and did not correlate with virus isolation. Group C were also IPNV carriers; virus could not be isolated using standard diagnostic methods but was isolated from the supernatants of stimulated leucocyte cultures of 44% of the fish. A significant inhibition of DNA synthesis in response to PHA stimulation was observed. The persistence of IPNV in Atlantic salmon is discussed in the light of the data presented here and existing knowledge of the persistence of mammalian viruses.