Tesis: "Hevea brasiliensis latex"

1

CAURET, LAUREN. "Nouveaux stimulants pour la production de latex par l'hevea brasiliensis". Le Mans, 1995. http://www.theses.fr/1995LEMA1017.

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Intapun, Jutharat. "Study of the effects of biological maturation of coagula of hevea brasiliensis latex on dry rubber properties". Montpellier SupAgro, 2009. http://www.theses.fr/2009NSAM0036.

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The aim of this work was to study the maturation phenomena undergone bycup coagula of Hevea brasiliensis latex. The experimental strategy was to firstcharacterize the maturation industrial conditions (temperature, relative humidity andoxygen content of the air), secondly to reproduce this maturation at laboratory scale inorder to, thirdly, be able to study the effect of key determinants such as microbialpopulation or enzymatic activity on processed natural rubber properties. The maturation conditions of cup rubber coagula stored as a pile in anindustrial plant have been characterized. This requested an optimization of theexperimental material used to measure conditions in order to get repeatable andconsistent data. It was found that temperature and relative humidity of the airincreased with depth within the pile. In contrast, oxygen content of the air within thepile decreased as depth increased. Effects of 24-day maturation in these conditions onrubber properties (pH, P0, PRI and Weight-average molar mass) were found to varywith the position of cup coagula within the pile. In order to be able to study maturation of coagula in laboratory controlledcondition, methodological and technical developments were performed and concernedthe design and optimization of a maturation device as well as of a dry rubber process(creping + drying). Before the development of devices, it was checked that thereduction of cup coagula size for practical experimental reasons would not induce anyartifact. The developed maturation device in laboratory was set up with 6 maturationunits, each of them being able to contain up to 18 mini-cup coagula. An assessment ofthe regulation of the maturation unit atmosphere showed that the developed deviceallowed the control of conditions in the following ranges: relative humidity10% - 90%, temperature 35°C - 45°C and oxygen content 0%-21%. Referring to thestudy of the conditions in cup coagula pile, it was decided to work at 40°C±1°C and90%±10% RH in the maturation device. The laboratory process parameters wereoptimized in order to obtain a rubber with the same quality as if it was processed infactory practice. In order to assess the involvement of microorganisms in the initial stage ofmaturation of natural rubber cup coagula, the inoculated rubber was characterized forits physical and structural properties for different maturation times. The resultsshowed that the quantity of microorganisms significantly affected the physicalproperties and molecular structure (Average-molar mass and gel content) of processedrubber. Microorganisms are not only involved in the increase of sensitivity to thermooxidationbut also in the crosslinking phenomenon between polyisoprene chains. Thetotal number of microorganisms in the inoculum was around 1x109 CFU/mL, amongwhich were yeasts, gram positive, gram negative and lactic acid bacteria. Fifteen ofthe 16 bacterial strains isolated from the inoculum used in latex treatments producedhydrolytic enzymes such as lipase, phospholipase and protease when inoculated inspecific media, thus potentially participating to lipid and protein degradation in latexand coagula. The addition of lipase in mini-cup coagula resulted in an increasedrelease of free fatty acids but had no significant effect on PRI evolution during thefirst 6 days of maturation. The main effect was observed in the presence of a protease,papain, which showed a clear positive dose-effect on enzyme concentration on P0. This enzyme also had an improving effect on PRI. The methodologies and devices developed during this study should serve as abasis for further studies aiming at a better understanding of the role ofmicroorganisms and enzymes in the variability of quality of natural rubber
L'objectif de ce travail était d'étudier le phénomène de maturation des coagula de latex d'Hevea brasiliensis. La stratégie expérimentale a consisté dans un premier temps à caractériser les conditions de maturations régnant sur un site industriel (température,humidité relative, teneur en oxygène de l'air), puis de reproduire ces conditions de maturation à l'échelle du laboratoire dans le but de pouvoir, dans une troisième phase, étudier l'effet de paramètres clés tels que la population microbienne ou l'activité de diverses enzymes sur les propriétés du caoutchouc naturel obtenu à partir de ces coagula. Les conditions de maturation des coagula de latex empilés sur un site industriel ont été caractérisées. Ceci a nécessité la mise au point d'un matériel expérimental spécifique permettant des mesures fiables et répétables. Nous avons montré que la température et l'humidité relative de l'air au sein du tas augmentent avec la profondeur, alors que la teneur en oxygène diminue jusqu'à des conditions d'anaérobiose. Après 24 jours de maturation dans ces conditions, les propriétés des coagula (pH) et du caoutchouc obtenu (P0, PRI, masse moléculaire moyenne) dépendent de la position des coagula au sein de la pile. L'étude de la maturation des coagula dans des conditions de laboratoire contrôlées a nécessité des développements méthodologiques et techniques aboutissant à la mise en place et à l'optimisation d'un dispositif de maturation contrôlée associé à un procédé miniaturisé de production de caoutchouc sec comprenant une étape de crêpage et un séchage au four. Ce dispositif a été confronté au système réel en vérifiant que la réduction d'échelle n'introduisait pas de biais dans les propriétés des produits étudiés. Le dispositif de maturation contrôlée est constitué de 6 unités pouvant fonctionner en parallèle, chacune d'entre elle pouvant contenir jusqu’à 18 échantillons. Les unités sont contrôlées en humidité relative (10%-90%), température (35Ê C - 45Ê C) et teneur en oxygène (0-21%). Sur la base des mesures réalisées sur site industriel, les études on été réalisées à 40Ê CØ+1Ê C et 90%Ø+10% d'humidité relative dans le dispositif de maturation. Nous avons ensuite démontré le rôle des microorganismes dans la maturation des coagula de latex et leur impact sur les propriétés du caoutchouc naturel sec en comparant les propriétés physiques et structurales, avant et après maturation, d'échantillons de caoutchouc issus de coagula inoculés avec des quantités variables de microorganismes provenant d'un coagulum industriel. Cette étude a mis en évidence un effet-dose des microorganismes sur ces propriétés. Les microorganismes contenus dans l'inoculum comprenaient des levures et des bactéries gram positives et gram négatives, dont des bactéries lactiques. Quinze des seize souches isolées produisaient des enzymes hydrolytiques, notamment à activité lipase, phospholipase et protéase, qui pourraient participer à la dégradation de lipides et protéines au sein du latex et des coagula. L'addition de lipase pure à des coagula dans lesquels le développement des microorganismes était inhibé a provoqué la libération d'acides gras sans toutefois modifier les propriétés du caoutchouc après 6 jours de maturation. Par contre, l'addition de papaÉine a provoqué une amélioration de la valeur de la viscosité initiale (P0) des échantillons directement liée à la quantité d'enzyme ajoutée. L'activité de cette protéase a également entraîné une augmentation de la résistance à la thermooxydation (PRI) du caoutchouc. Les méthodologies et outils développés au cours de se travail devraient permettre le développement de futures recherches visant à comprendre le rôle des microorganismes et des enzymes dans la variabilité de la qualité du caoutchouc naturel

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3

Gomes, Willian Pereira. "Prevulcanização do látex natural extraído da "hancornia speciosa gomes" (Mangabeira) e da "hevea brasiliensis" (seringueira) /". Ilha Solteira, 2013. http://hdl.handle.net/11449/136022.

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Orientador: José Antonio Malmonge
Banca: Rosangela da Silva de Lauretiz
Banca: Rogério Manoel Biagi Moreno
Resumo: A borracha natural é um dos polímeros mais consumidos mundialmente, onde seu principal mercado é o setor pneumático com cerca de três quartos do consumo total. A seringueira é a mais importante produtora de borracha natural, sendo responsável por cerca de 99% da produção mundial A mangabeira é também uma arvore lactescente produzida quase em sua totalidade de forma extrativista e visada somente para a produção do seu fruto, a mangaba. Embora já ter sido utilizada comercialmente em períodos emergenciais, hoje a borracha natural provinda da mangabeira não tem qualquer utilização tecnológica, pois é considerada uma borracha de qualidade inferior. Neste trabalho foram produzidos filmes de borracha prevulcanizada com o látex de seringueira, de mangabeira e também com a mistura (m/m) do látex de mangabeira no látex de seringueira, nas proporções de 95/5, 90/10, 80/20, 70/30 e 60/40. Os resultados mostraram que o número de ligações cruzadas, tensão na ruptura e dureza Shore A são dependentes do sistema de vulcanização convencional, semi-eficiente ou eficiente, e da temperatura e do tempo de cozimento do latex de ambas as fontes. Os valores dessas propriedades encontrados para a borracha da mangabeira foram inferiores ao da borracha da seringueira. O maior valor de tensão de ruptura, dureza Shore e deformação encontrada para a borracha de seringueira foi alcançado utilizando o sistema convencional com 3 horas de cozimento sob 80°C. Esses valores são: 22 MPa, 42 Shore A e 895% o que é aproximadamente 150%, 68% e 25%, respectivamente, maiores do que os maiores valores encontrados para a borracha da mangabeira (8,8 MPa, 25 Shore A e 714%) que foi obtido utilizando o sistema semi-eficiente. As borrachas obtidas da mistura dos látex apresentaram, para composições inferiores a 20%, em massa de borracha de mangabeira, um comportamento similar a da seringueira mostrando ser viável a sua utilização para fabricação...
Abstract: Natural rubber is one of the most consumed polymer in the worldwide and pneumatic industry is responsible for approximately three fourths of total consumption. Hevea brasiliensis is the most important producer of natural rubber, being responsible for 99% of global production. The Hancornia speciosa Gomes is also produces white latex that can be tapped from the tree similarly to Hevea. Although it has been used commercially in emergency periods, nowadays Hancornia rubber has no technology use due to its low production and rubber quality. The latex blend can be a viable alternative to the use of mangabeira latex as one additional income besides of fruit commercialization. In this sense, the proposal of this work was to evaluate the influence of prevulcanization condition in the Hancornia speciosa Gomes (mangabeira) and Hevea brasiliensis (seringueira) latexes and also in its mixture, on the rubber proprieties. The latexes were prevulcanizated by conventional (CV), semi-efficient (SEV) and efficient (EV) vulcanization systems under temperatures of 60, 70 and 80 ° C. The crosslinked quantity was investigated by the swelling technique and the mechanical proprieties were obtained from tensile experiments and shore A hardness. The results showed that the quantity of crosslinked, stress at break and shore hardness are dependent of prevulcanization condition. The values of these proprieties found for mangabeira rubber were lower than the values found for the seringueira rubber. The highest stress at break, shore hardness and strain to seringueira and mangabeira rubber were obtained using the CV and SEV systems, respectively, under temperature of 80° C for 3 hours. Theses value are: 22 MPa, 42 shore A and 895% that are around 150%, 68% e 25%, respectively, higher than found to mangabeira rubber (8,8 MPa, 25 Shore A and 714%). The rubbers obtained from mixture of latex have the mechanical proprieties closed to the seringueira rubber for blends ...
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Bahari, Azlina. "Approaches to understanding diversity in rubber and carotenoid synthesis in Hevea brasiliensis latex". Thesis, University of Dundee, 2019. https://discovery.dundee.ac.uk/en/studentTheses/73b6fffb-faf0-4fb9-94f1-aa9bbb330154.

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Hevea brasiliensis latex contains a large quantity of high molecular weight rubber and is thus the primary commercial source of natural rubber. Rubber and other non-rubber isoprenoids in Hevea latex are synthesised from isopentenyl diphosphate (IPP) generated from the cytoplasmic mevalonate (MVA) pathway and the plastidic methyl erythritol phosphate pathway (MEP). This study utilised two rubber tree clones (RRIM600 and PB235) that show visibly contrasting levels of yellow carotenoids for the measurement of latex isoprenoids (carotenoids, rubber and isoprenoid intermediates) and transcript levels of the genes involved in isoprenoid biosynthesis. Metabolite extraction and analysis showed that four major carotenoids namely lutein, zeaxanthin, α-carotene and β-carotene were consistently present in both RRIM600 and PB235 latex. β-carotene was found to be the major carotenoid, at 1.2 μg/g in PB235 and 0.8 μg/g in RRIM600 fresh latex samples. However, the analytical method developed to measure isoprenoid intermediates needed to be further optimised to increase extraction efficiency. To enable accurate measurement of transcript levels of key genes involved in the isoprenoid biosynthetic pathway, a set of reference transcripts was constructed by merging short-reads (RNA-seq) and long-reads (Iso-seq and full-length cDNA sequences) data from Hevea brasiliensis. This produced a comprehensive set of 193,997 transcript sequences with good level of coverage of predicted transcripts and highly conserved core plant genes. Not only did the reference transcriptome update the annotation of rubber gene models, additional transcript variants were also discovered. Manual curation of gene models for key steps associated with rubber and carotenoids resulted in a repertoire of 115 genes, with 151 corresponding transcript variants. Subsequently, differential expression analysis on the basis of mapping RRIM600 and PB235 RNA-seq reads to the reference transcriptome revealed isoform-specific expression of genes for biosynthesis of carotenoids (PSY isoform 2), IPP (AACT2 and HMGR1) and rubber (REFSRPP gene members). In addition, the levels of these genes correlated positively with the carotenoid and rubber content measurements from the same latex of PB235 and RRIM600 used for metabolite extraction. Finally, the utility of the reference transcript catalogue was demonstrated by the characterisation of the REFSRPP gene family, which is involved in rubber elongation steps. REFSRPP gene family showed a local expansion which appear to be unique to Hevea. A pilot study has demonstrated there is considerable diversity of the genomic region containing the duplicated REFSRPP genes.

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Piyatrakul, Piyanuch. "Caractérisation des gènes AP2/ERF impliqués dans le développement chez Hevea brasiliensis". Thesis, Montpellier, SupAgro, 2013. http://www.theses.fr/2013NSAM0033/document.

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Hevea brasiliensis est une culture industrielle majeure pour la production de caoutchouc naturel (CN). La stimulation par l'éthéphon, un libérateur d'éthylène, est utilisée pour augmenter la production de latex en prolongeant son écoulement et en stimulant le métabolisme pour la régénération du latex. Cependant, le mécanisme d'action de l'éthylène n'est pas clairement élucidé chez l'hévéa. L'éthylène est un signal important qui régule le développement des plantes. Les facteurs de transcription AP2/ERF, et plus particulièrement les Ethylene Response Factors, jouent un rôle crucial dans le développement et la réponse aux stress biotiques et abiotiques chez les plantes. La production d'éthylène et sa signalisation sont aussi importantes en embryogenèse somatique et tout spécialement chez les espèces récalcitrantes à la culture in vitro.Dans cette étude, le transcriptome de référence a été amélioré par addition des fragments de séquence d'ARN issus de tissus reproducteurs lors d'un nouvel assemblage. Les 30.342 contigs ont été annotés par la base de données Gene Ontology. L'analyse des facteurs de transcription a permis d'identifier 2.448 contigs qui ont été classés en 58 familles de facteurs de transcription. Six pourcents de ces facteurs de transcription correspondent aux membres de la superfamille des AP2/ERF. L'accumulation de transcrits des gènes AP2/ERF a été analysée au cours du processus d'embryogenèse somatique chez des lignées de cal avec différents potentiels de régénération et dans différents tissus végétatifs et reproducteurs. L'analyse de l'abondance relative de transcrits dans les différents tissus montre que les ERFs des groupes I, VII et VIII sont fortement présents à tous les stades de l'embryogenèse somatique et dans les tissus immatures et matures de fleurs males et femelle, d'embryons zygotiques, de feuilles, d'écorce et de latex. Quarante gènes AP2/ERF représentent des marqueurs d'expression génique pour le potentiel de régénération de plantes de lignées de cal à différents stades du processus d'embryogenèse somatique. Quatorze marqueurs d'expression génique permettent même de prédire la capacité de régénération dès le stade de multiplication du cal. Cinquante-neuf marqueurs d'expression géniques sont spécifiquement exprimés dans les différents tissus de l'hévéa, et plusieurs AP2/ERFs ont les transcrits fortement accumulés dans le latex. La plupart des marqueurs de l'expression génique du latex appartient aux ERF du groupe VII. Les ERFs de ce groupe ont un motif conservé en N-terminal (MCGGAII), lequel est impliqué dans la voie N-end rule. Les analyses de localisation subcellulaire et de transactivation suggèrent que ces gènes HbERF-VII codent pour des facteurs de transcription fonctionnels potentiellement impliqués dans la réponse à l'hypoxie dans le latex
Hevea brasiliensis is the major industrial crop for natural rubber (NR) production. Ethephon stimulation, an ethylene releaser, is used for increasing latex production by prolonging latex flow and stimulating the metabolism required for the latex regeneration. However, the mechanism of ethylene action is not clearly elucidated in this species. Ethylene is an important signal regulating the plant development. AP2/ERF transcription factors, and especially Ethylene-Response Factors, play a crucial role in plant development and response to biotic and abiotic stresses. Ethylene production and signalling are also important to somatic embryogenesis, especially for species that are recalcitrant in in vitro culture.In this study, a comprehensive Hevea transcriptome was improved using additional RNA reads from reproductive tissues in a new assembly. The 30,342 contigs were annotated in the Gene Ontology database. The analysis of transcription factors led to 2,448 contigs being identified, which were classed in 58 transcription factor families. Six percent of the transcription factors corresponded to members from the AP2/ERF superfamily. The transcript accumulation of AP2/ERF genes was analyzed during somatic embryogenesis for callus lines with different regeneration potential and in various vegetative and reproductive tissue of Hevea. The relative transcript abundance were studied and showed that ERFs from group I, VII and VIII were abundant at all stages of the somatic embryogenesis as well as, in both immature and mature male and female flowers, zygotic embryos, leaf, bark and latex. Forty genes were identified as expression marker for callus with different plant regeneration potential regeneration capacity. Interestingly, fourteen expression marker genes were found that be able to predict the regeneration capacity of callus at proliferating calli, the early stage of somatic embryogenesis process. Fifty-nine expression marker genes were found in the various plant tissues. Several AP2/ERF genes were shown highly transcript accumulation in latex and were assigned as latex expression marker genes. Almost of latex expression marker genes belong to the ERF group VII. Base on conserved motif analysis showed this ERF group contained the conserved N-terminal motif (MCGGAII) involved in the N-end rule pathway. Subcellular localization and transactivation analyses suggested that HbERF-VII candidate genes encoded functional transcription factors

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Carlos, Bruna Leonel. "Efeitos da membrana de látex na regeneração de defeito ósseo em tíbia de rato". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17142/tde-02042018-112204/.

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Problemas de consolidação óssea são um grande desafio clínico, pois geram altos custos de tratamento, morbidades e prejuízos a qualidade de vida. A técnica de regeneração óssea guiada é empregada com o intuito de promover a melhora no processo de regeneração de defeitos ósseos através da utilização de barreiras biológicas, que protegem o local da lesão e favorecem a ação de células osteogênicas. A membrana de látex natural, extraído da seringueira Hevea brasiliensis tem sido apontado como um biomaterial promotor da regeneração em diferentes tecidos, e por este motivo escolhido como objeto de estudo desta pesquisa. O objetivo foi avaliar o efeito da utilização de membrana de látex natural no processo de regeneração guiada de defeito ósseo em ossos longos de ratos, através de análises estruturais, radiológicas, microscópicas e da expressão de proteínas osteogênicas. Foram utilizados sessenta ratos Wistar divididos igualmente em quatro grupos (n=15), sendo: animais tratados com membrana de látex por uma (L1) ou quatro semanas (L4) e animais que não receberam tratamento específico por uma (C1) ou quatro semanas (C4). Um defeito ósseo de 2,5 mm de diâmetro foi realizado na região medial da tíbia esquerda de cada animal. Nos animais do grupo tratado, uma membrana de látex foi posicionada sobre os defeitos ósseos. Após os períodos experimentais de uma ou quatro semanas os animais foram submetidos a eutanásia e a tíbia esquerda de cada animal foi dissecada, limpa das partes moles e submetida às análises macroscópica, densitométrica, radiológica, mecânica, histomorfométrica, estereológica e imunohistoquímica. A influência das varáveis tempo e membrana, bem como a interação tempo*membrana sobre os dados foram avaliadas. Para os dados referentes à imunomarcação de osteocalcina foi aplicado teste de modelo linear generalizado com fatores independentes. Para o restante dos resultados foi realizada análise de ANOVA multivariada com dois fatores independentes. Todas as comparações foram realizadas com ajuste de Bonferroni e adotado nível de significância de 5%. Foram observadas diferenças estatisticamente significantes em relação a variável tempo, em que grupos avaliados quatro semanas após a cirurgia apresentaram resultados superiores para as medidas de comprimento (p<0,001), massa (p<0,001), força máxima (p<0,001) e rigidez relativa da tíbia (p<0,001), bem como para as medidas de densidade radiológica (p=0,008), densidade mineral óssea (p=0,017), volume ósseo neoformado (p<0,001) e fibras de colágeno tipo III (p<0,001). Em relação à utilização da membrana de látex, os grupos tratados apresentaram resultados estatisticamente superiores para as análises de rigidez relativa (p=0,048), fibras de colágeno tipo I (p=0,018), volume ósseo neoformado (p<0,001) e expressão de osteopontina (p=0,037). Concluímos que a utilização de membrana de látex em regeneração óssea guiada em defeitos realizados em tíbias de ratos melhorou sensivelmente a regeneração do tecido.
Problems of bone consolidation are a significant clinical challenge, as they generate high treatment costs, morbidities, and damages to the quality of life. The guided bone regeneration technique is used to improve the regeneration process of bone defects through the use of biological barriers that protect the site and favor the action of osteogenic cells. The natural latex membrane extracted from the rubber tree Hevea brasiliensis has been identified as a biomaterial promoting regeneration in different tissues, and for this reason chosen as the object of study of this research. The objective was to evaluate the effect of the use of natural latex membrane in the process of guided regeneration of bone defect in long bones of rats, through structural, radiological, microscopic analysis and the expression of osteogenic proteins. Sixty Wistar rats were equally divided into four groups (n = 15): latex membrane treated animals for one (L1) or four weeks (L4) and animals that received no specific treatment for one (C1) or four weeks (C4). A bone defect of 2.5 mm diameter was performed in the medial region of the left tibia of each animal. In the animals of the treated group, a latex membrane was positioned over the bone defects. After the experimental periods of one or four weeks, the animals were submitted to euthanasia, and the left tibia of each animal was dissected, cleaned of soft parts and submitted to macroscopic, densitometric, radiological, mechanical, histomorphometric, stereological and immunohistochemical analysis. The influence of the variable time and membrane as well as the time * membrane interaction on the data were evaluated. For the data referring to the osteocalcin immunostaining, a generalized linear model with independent factors was applied. For the rest of the results, a multivariate ANOVA analysis was performed with two independent factors. All comparisons were performed with Bonferroni adjustment and adopted a significance level of 5%. Statistically significant differences were observed in relation to the time variable, in which groups evaluated four weeks after surgery presented superior results for the measures of length (p <0.001), mass (p <0.001), maximal strength (p <0.001) and stiffness (P <0.001), as well as for measurements of radiological density (p = 0.008), bone mineral density (p = 0.017), neoformed bone volume (p <0.001) and type III collagen fibers (p <0.001) ). About the use of the latex membrane, the treated groups presented statistically superior results for analyzes of relative stiffness (p = 0.048), type I collagen fibers (p = 0.018), neoformed bone volume (p <0.001) and expression of Osteopontin (p = 0.037). We conclude that the use of latex membrane in guided bone regeneration in defects performed in rat tibiae significantly improved tissue regeneration.

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Gomes, Willian Pereira [UNESP]. "Prevulcanização do látex natural extraído da hancornia speciosa gomes (Mangabeira) e da hevea brasiliensis (seringueira)". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/136022.

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A borracha natural é um dos polímeros mais consumidos mundialmente, onde seu principal mercado é o setor pneumático com cerca de três quartos do consumo total. A seringueira é a mais importante produtora de borracha natural, sendo responsável por cerca de 99% da produção mundial A mangabeira é também uma arvore lactescente produzida quase em sua totalidade de forma extrativista e visada somente para a produção do seu fruto, a mangaba. Embora já ter sido utilizada comercialmente em períodos emergenciais, hoje a borracha natural provinda da mangabeira não tem qualquer utilização tecnológica, pois é considerada uma borracha de qualidade inferior. Neste trabalho foram produzidos filmes de borracha prevulcanizada com o látex de seringueira, de mangabeira e também com a mistura (m/m) do látex de mangabeira no látex de seringueira, nas proporções de 95/5, 90/10, 80/20, 70/30 e 60/40. Os resultados mostraram que o número de ligações cruzadas, tensão na ruptura e dureza Shore A são dependentes do sistema de vulcanização convencional, semi-eficiente ou eficiente, e da temperatura e do tempo de cozimento do latex de ambas as fontes. Os valores dessas propriedades encontrados para a borracha da mangabeira foram inferiores ao da borracha da seringueira. O maior valor de tensão de ruptura, dureza Shore e deformação encontrada para a borracha de seringueira foi alcançado utilizando o sistema convencional com 3 horas de cozimento sob 80°C. Esses valores são: 22 MPa, 42 Shore A e 895% o que é aproximadamente 150%, 68% e 25%, respectivamente, maiores do que os maiores valores encontrados para a borracha da mangabeira (8,8 MPa, 25 Shore A e 714%) que foi obtido utilizando o sistema semi-eficiente. As borrachas obtidas da mistura dos látex apresentaram, para composições inferiores a 20%, em massa de borracha de mangabeira, um comportamento similar a da seringueira mostrando ser viável a sua utilização para fabricação...
Natural rubber is one of the most consumed polymer in the worldwide and pneumatic industry is responsible for approximately three fourths of total consumption. Hevea brasiliensis is the most important producer of natural rubber, being responsible for 99% of global production. The Hancornia speciosa Gomes is also produces white latex that can be tapped from the tree similarly to Hevea. Although it has been used commercially in emergency periods, nowadays Hancornia rubber has no technology use due to its low production and rubber quality. The latex blend can be a viable alternative to the use of mangabeira latex as one additional income besides of fruit commercialization. In this sense, the proposal of this work was to evaluate the influence of prevulcanization condition in the Hancornia speciosa Gomes (mangabeira) and Hevea brasiliensis (seringueira) latexes and also in its mixture, on the rubber proprieties. The latexes were prevulcanizated by conventional (CV), semi-efficient (SEV) and efficient (EV) vulcanization systems under temperatures of 60, 70 and 80 ° C. The crosslinked quantity was investigated by the swelling technique and the mechanical proprieties were obtained from tensile experiments and shore A hardness. The results showed that the quantity of crosslinked, stress at break and shore hardness are dependent of prevulcanization condition. The values of these proprieties found for mangabeira rubber were lower than the values found for the seringueira rubber. The highest stress at break, shore hardness and strain to seringueira and mangabeira rubber were obtained using the CV and SEV systems, respectively, under temperature of 80° C for 3 hours. Theses value are: 22 MPa, 42 shore A and 895% that are around 150%, 68% e 25%, respectively, higher than found to mangabeira rubber (8,8 MPa, 25 Shore A and 714%). The rubbers obtained from mixture of latex have the mechanical proprieties closed to the seringueira rubber for blends ...

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Agostini, Deuber Lincon da Silva [UNESP]. "Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/103766.

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Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias
Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties

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Agostini, Deuber Lincon da Silva. "Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese /". Bauru, 2013. http://hdl.handle.net/11449/103766.

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Orientador: Aldo Eloizo Job
Banca: Mariselma Ferreira
Banca: Ivan Helmuth Bechtold
Banca: José Antonio Malmonge
Banca: Eduardo René Perez
Resumo: Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias
Abstract: Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties
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Yusof, Faridah. "Factors affecting the formation of rubber from isopentenyl pyrophosphate in Hevea brasiliensis latex". Thesis, University of Hertfordshire, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361264.

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Kuswanhadi. "Isolement et caractérisation des gènes ACS et ACO impliqués dans la biosynthèse de l’éthylène chez Hevea brasiliensis : évaluation de leur rôle dans la production de caoutchouc naturel". Montpellier 2, 2006. http://www.theses.fr/2006MON20201.

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Bellacicco, Sophie. "Etude de l’impact de l’origine clonale du latex d’Hevea brasiliensis sur la composition biochimique du latex et la mésostructure du caoutchouc naturel". Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0003.

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Le caoutchouc naturel produit du latex d'Hevea brasiliensis a des propriétés remarquables qui n'ont jamais été égalées par ses homologues synthétiques. Toutefois, ce matériau d'origine naturel présente un désavantage : la variabilité non négligeable de ses propriétés. Cette dernière est partiellement attribuée aux 3 à 5 % de composés non isoprènes (lipides, protéines, sucres et minéraux) présents dans le caoutchouc naturel. Parmi les facteurs pouvant être tenus comme responsables de cette variabilité, l'origine clonale semble prépondérante. L'objectif principal de cette étude était d'évaluer l'impact de l'origine clonale sur la variabilité en composition biochimique du latex (lipides, protéines, sucres et éléments minéraux) et sur les caractéristiques mésostructurales du caoutchouc naturel; puis d'étudier les relations pouvant exister entre le génotype, la composition biochimique du latex et la mésostructure du caoutchouc. Cette étude a été conduite sur 5 clones d'Hevea brasiliensis : GT1, RRIM600, PB235, PB217 et PB260. Des études préalables à la caractérisation clonale ont permis de déterminer les conditions d'échantillonnage à mettre en œuvre pour pratiquer des prélèvements de latex clonaux les plus représentatifs possible des clones. Le latex étant un matériau instable, il été choisi de travailler sur du latex lyophilisé pour l'analyse de tous les composés biochimiques du latex (autres que les lipides) et pour l'étude de la mésostructure du caoutchouc naturel. Des protocoles d'extractions des protéines et des sucres sur lyophilisat de latex ont été développés en se basant sur les propriétés de solubilisation du caoutchouc naturel en milieu organique. L'extraction des lipides a été réalisée en suivant le protocole mis au point sur plantation sur latex frais par Liengrayoon (Liengprayoon, 2008). Les différents résultats obtenus au niveau de la composition biochimique du latex et de la mésostructure du caoutchouc ont permis de mettre en évidence l'importante de l'origine clonale des latex. L'étude des relations entre le génotype et la composition biochimique du latex (ACP) a clairement montré que l'origine clonale jouait un rôle important dans la variabilité totale des données biochimiques du latex. Les analyses des relations entre la biochimie du latex et la mésostructure du caoutchouc naturel ont permis de mettre en évidence des corrélations intéressantes des lipides et des protéines avec la mésostructure (essentiellement Mn et I). Cette analyse biochimique clonale des latex s'est révélée pertinente pour étudier la diversité clonale et ses répercutions sur la mésostructure du caoutchouc naturel. Cette approche de la diversité clonale d'Hevea brasiliensis, ainsi que les connaissances acquises lors de cette étude constituent une base de données solide à compléter par des études futures sur des plantations différentes, des clones différents et des analyses biochimiques et structurales plus poussées
Natural rubber produced from Hevea brasiliensis latex possesses remarkable properties which have not been matched by its synthetic counterparts. However, this natural origin material presents a disadvantage: the significant variability of its properties. This variability has been partly ascribed to the 3 to 5% non isoprene components (lipids, proteins, sugars and minerals) present in the natural rubber. Among the factors that could be held responsible for this variability, clonal origin seems to be decisive.The main aim of this study was to evaluate the impact of clonal origin on the biochemical latex composition and on natural rubber mésostructural characteristics and also to study relationships between genotype, latex biochemical composition and rubber mesostructure. This study was conducted with five Hevea brasiliensis clones: GT1, RRIM600, PB235, PB217 and PB260. Before clonal characterization, preliminary studies were performed to determine the suitable sampling conditions in order to get the latex samples that represented as much as possible the clones. Fresh latex is an unstable material. It was decided to work on freeze-dried latex for the biochemical components analysis (except lipids) and for the natural rubber mesostructure study. Protocols for proteins and sugars' extractions on freeze-dried latex have been developed on the natural rubber solubilizing properties in organic media. Lipids extractions was performed according to the protocol developed by Liengrayoon (Liengprayoon , 2008) on fresh latex.The different results obtained on the latex biochemical composition and the natural rubber mesostructure allowed to clearly observe the clonal origin importance. Study of relationships between genotype and latex biochemical composition (PCA) has clearly shown that the clonal origin played an important role in the total variability of latex biochemical data. Analysis of relationships between latex biochemistry and natural rubber mesostructure helped highlight interesting correlations of lipids and proteins with mesostructure (mainly Mn and I).This biochemical analysis of clonal latex has proved to be appropriate for studying the clonal diversity and its repercussions on the natural rubber mesostructure. This approach of Hevea brasiliensis clonal diversity, and the knowledge gained from this study, provides a solid basis to be completed by further studies on different plantations, different clones and further biochemical and structural analyses

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Gallois, Richard. "Métabolisme des nucléotides adényliques dans le latex de l'"Hevea brasiliensis". Effets de l'éthylène". Montpellier 2, 1998. http://www.theses.fr/1998MON20116.

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Une phosphoribosylpyrophosphate synthetase (prs) d'origine vegetale (latex d'hevea brasiliensis) a ete, pour la premiere fois, purifiee a homogeneite (visualisee apres sds-page) et les mecanismes de controle de son activite dans le cytosol ont ete analyses. La presence de deux adenylate kinase (ak) a ete confirmee. Quelques une des caracteristiques biochimiques de l'ak fortement liee aux membranes du compartiment vacuolysosomal du latex (lutoides) ont ete etudiees. Un nouvel effet de l'ethylene a ete mis en evidence sur le metabolisme energetique du latex, par l'augmentation transitoire des activites specifiques adenine phosphoribosyltransferase (aprt) et prs. Cette activation, concomitante de l'accroissement de la taille du pool adenylique, contribue a expliquer l'effet de l'ethylene sur la synthese de nucleotides adenyliques. Ces resultats permettent d'une part d'entrevoir certains mecanismes de controle de la synthese des nucleotides adenyliques et d'autre part de mieux comprendre l'action tres complexe de l'ethylene sur la production du latex, mais aussi sur les tissus vegetaux en general.

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Kerche-Silva, Leandra Ernst. "Avaliação in vitro e in vivo da capacidade antioxidante e antitumoral da fração C do látex de Hevea brasiliensis RRIM 600 /". Presidente Prudente, 2017. http://hdl.handle.net/11449/148926.

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Orientador: Aldo Eloizo Job
Banca: Eduardo Rene Perez Gonzalez
Banca: Edgardo Alfonso Gomes Pineda
Banca: Antonio Hernandes Chaves Neto
Banca: Aneli de Melo Barbosa
Resumo: Biomateriais podem ser definidos como dispositivos que entram em contato com sistemas biológicos tanto na forma de sólidos quanto de líquidos e géis. Para um novo biomaterial, são necessários testes toxicológicos e de interação in vitro e in vivo. O látex é uma substância branca e leitosa que exsuda da casca da Hevea brasiliensis quando a mesma é perfurada e que tem sido apontado como um biomaterial promissor. O látex quando centrifugado em alta velocidade é separado em três frações: a fração com partículas de borracha, uma fração aquosa chamada fração C e uma fração de fundo chamada fração B. A fração C é a fração metabolicamente ativa do látex. Assim, o presente estudo investigou os potenciais efeitos antioxidantes, citotóxicos, genotóxicos e antitumorais da fração C do látex da Hevea brasiliensis. Para isso, foram utilizados os testes de sequestro de radicais livres e capacidade antioxidante total em meio in vitro sem células; o teste do MTT, o ensaio do cometa, avaliação de morte celular com coloração com Hoechst 33342 e Iodeto de Propídio (PI) e avaliação de parâmetros bioquímicos de estresse oxidativo em meio in vitro com duas linhagens celulares, a CHO-k1, linhagem de células normais de epitélio de ovário de hamster, e a B16F10, linhagem de células de melanoma murino; e a ação da fração C na indução de carcinoma de células escamosas (SCC) em camundongos SKH-1 por exposição crônica à radiação UVB. Nossos resultados mostraram que a fração C é antioxidante, com capacidade... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Biomaterials can be defined as devices that come in contact with biological systems in the form of solids, liquids and gels. In vitro and in vivo toxicological tests are needed for a new biomaterial to come out. Latex is a while and milky solution that exsudes from Hevea Brasiliensis bark when perforated, and it has been appointed as a new promising biomaterial. When centrifuged in high speed, latex can be separated in three parts: rubber particle fraction, aqueous C-serum fraction and a bottom fraction called B-serum. C-serum is the part that is metabolically active. In this way, the aim of this work was to investigate potential antioxidant, cytotoxic, genotoxic and antitumor effect of latex C-serum from Hevea brasiliensis. For this purpose, we used in vitro free-radical scavenger and total antioxidant capacity tests; MIT test, comet assay, staining with Hoechst 33342 and Propidium Iodide (PI) to evaluate cell death, and evaluation of biochemical parameters of oxidative stress in Chinese hamster ovary epithelium normal cell line, CHO-K1, and murine melanoma cell line, B16F10; and C-serum effects in the inductino of squamous cell carcinoma (SCC) in KKH-1 mice by chronic UVB exposure. Our results show that latex C-serum is an antioxidant compound that was able to scavenge HO and NO radicals and H2O2. C-serum did not after the cell viability in CHO-k1 cells and it did not promote DNA damage in these cells, it did not after the levels of apoptotic and necrotic cells for this cell lineage and did not alter total thiol and MDA levels in these cells. However, for B16F10 cells, latex C-serum presented antitumor effect, reducing cell viability, inducing DNA damage and cell death, and altering total thiol and MDA levels in these cells. In the animals chronically exposed to UVA radiation, latex C-serum proteted the erythrocytes and skin cells from oxidative stress promote by the irradiation, and... (Complete abstract electronic access below)
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Salomez, Mélanie. "Etude du rôle des microorganismes dans les modifications biochimiques intervenant lors de la maturation des coagulums de latex d’Hevea brasiliensis : impact sur les propriétés du caoutchouc naturel sec". Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0002.

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L'objectif général de cette thèse était d'étudier les mécanismes microbiens intervenant dans l'évolution de la structure et des propriétés du caoutchouc naturel produit à partir du latex d'Hevea brasiliensis lors de la maturation du latex et des coagula de tasse. Pour cela, trois niveaux d'analyses ont été réalisés sur des expériences de maturation en conditions contrôlées : analyse de la structure et des propriétés du caoutchouc sec, analyse des flores microbiennes et analyses biochimiques. Après une phase de mises au point méthodologiques permettant notamment d'optimiser les conditions de maturation en chambre contrôlée et de définir une méthode d'extraction d'ADN adaptée au latex et au sérum de coagulum, des échantillons de caoutchouc sec et de sérum ont été produits à différents temps de maturation et selon différents traitements faisant varier trois paramètres : la présence de microorganismes, la présence d'oxygène, et le mode de coagulation du latex. Les analyses sur caoutchouc sec se sont portées sur la macrostructure (P0, P30 et PRI) et sur la mésostructure (Mw, Mn et gel total). L'analyse des flores microbiennes s'est appuyée sur plusieurs méthodologies complémentaires : comptages sur boîtes, dosage de l'ADN total, clonage/séquençage et pyroséquençage 454. L'objectif était d'évaluer la diversité des flores sur plantation et dans le latex ainsi que de suivre la dynamique de leur évolution au cours de la maturation en milieu contrôlé. Diverses analyses biochimiques ont réalisées sur latex, sérum et caoutchouc sec (taux d'azote, protéines, lipides, sucres, québrachitol, acides organiques). Les résultats obtenus ont ensuite été analysés en vue d'établir des corrélations et de proposer des mécanismes reliant l'évolution des propriétés du caoutchouc sec à celle de la biochimie du latex et des coagula et de leur évolution sous l'action des microorganismes et des enzymes, et de proposer quelques pistes en vue de l'amélioration des itinéraires techniques dans la filière
The overall objective of this thesis was to study the microbial mechanisms involved in the evolution of the structure and the properties of the natural rubber from Hevea brasiliensis during the maturation of latex and cup-coagula. For this, three levels of analyses were performed on maturation experiments under controlled conditions: dry rubber structure and properties, biochemistry and microbial flora. After a methodology development phase aiming at (i) optimizing maturation conditions in a controlled chamber and (ii) defining suitable DNA extraction methods, samples of serum and dry rubber coagulum were produced at different times and under different maturation treatments varying three parameters: the presence of microorganisms, the presence of oxygen, and the latex coagulation method. Dry rubber analyses concerned macrostructure (P0, P30 and PRI) and mesostructure (Mw, Mn and total gel). The microbial flora was analyzed using several complementary methods: plate-counts, total DNA determination, cloning / sequencing and 454 pyrosequencing. The objective was to assess microbial diversity on field and in latex, and to follow the dynamics of their evolution during maturation in a controlled environment. Various biochemical investigations were performed on latex, serum and dry rubber (nitrogen content, proteins, lipids, sugars, quebrachitol, organic acids). The results were then analyzed for correlations to propose mechanisms linking changes in dry rubber properties, latex and coagula biochemistry, and their evolution under the action of microorganisms and enzymes. Some ideas for improving technical routes in the process are also proposed

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Friolani, Milena [UNESP]. "Utilização da biomembrana de látex de seringueira (Hevea brasiliensis) em lesões diafragmáticas de coelhos: estudo experimental". Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/89027.

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Tendo em vista as propriedades de aceleração do processo cicatricial com utilização da biomembrana de látex, este trabalho teve como objetivo avaliar o comportamento de retalho de biomembrana natural de látex, em lesões diafragmáticas induzidas experimentalmente em coelhos. Utilizaram-se 15 coelhos sadios, raça Nova Zelândia, adultos, machos e fêmeas, tendo como acesso ao diafragma, o 8º espaço intercostal direito. Os animais foram divididos, aleatoriamente, em cinco grupos experimentais de três cada, e avaliados diariamente desde o dia da cirurgia até a eutanásia, quanto ao comportamento, freqüência respiratória e cardíaca, cicatrização externa. Os animais foram eutanasiados aos 15, 30, 45, 60 e 90 dias de pós cirúrgico, obtendo-se uma avaliação macroscópica e microscópica do conjunto diafragma/enxerto. Todos os animais apresentaram evolução clínica satisfatória. Macroscopicamente, em todos os grupos experimentais observou-se boa cicatrização na região do implante, com exceção de um dos animais eutanasiados aos quinze dias. Após quinze dias, houve neoformação tecidual, e após trinta dias do ato operatório, em todos animais observou-se aderência do fígado e do pulmão na área de implante. As observações clínico-cirúrgicas complementadas pela análise das alterações histológicas, permitiram concluir pela indicação do emprego da membrana de látex em lesões diafragmáticas reparadoras, em razão da facilidade de obtenção, custo baixo, fácil aplicabilidade, resistência e resposta satisfatória em relação ao tempo de cicatrização.
Having in mind the acceleration properties of the cicatricial process by using the latex bio-membrane, the present paper was aimed at evaluating the behavior of the natural latex bio-membrane flap in diaphragmatic lesions experimentally induced in rabbits. Fifteen healthy New Zealand rabbits, adults, males and females were used, having the eighth right intercostal space as an access to the diaphragm. The animals were randomly assigned to five experimental groups, each with three rabbits. They were evaluated daily from the day of surgery to the day of euthanasia in relation to behavior, respiratory and cardiac frequencies and external cicatrization. The animals were euthanized in 15, 30, 45, 60 and 90 days after the surgery and it was obtained a macroscopic and microscopic evaluation of the set diaphragm/graft. All rabbits presented a satisfactory clinical evolution. Macroscopically, in all experimental groups it was observed a good cicatrization of the implant region, except for one animal that was euthanized in 15 days. After fifteen days, there was tissular neo-formation and thirty days after surgery in all animals it was observed the adherence of the liver and lungs in the implant area. The clinical surgical observations complemented by the analysis of histological alterations allowed the conclusion in favor of the indication of using the latex membrane in reparative diaphragmatic lesions because of the easy obtainment, low cost, easy applicability, resistance, and satisfactory response in relation to the cicatrization time.

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Andrade, Thiago Antonio Moretti de. "Atividade da biomembrana de látex natural da seringueira Hevea brasiliensis na neoformação tecidual em camundongos". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/17/17138/tde-08072008-143229/.

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A biomenbrana de látex natural (BLN) da serigueira HEVEA brasiliensis, utilizada como curativo no tratamento de úlceras crônicas em humanos, mostra-se eficaz no desbridamento e no estímulo à granulação, acelerando a cicatrização. Seu mecanismo de ação ainda é desconhecido, tornando-se importante avaliar sua atividade como implante na indução tecidual, comparando-a aos outros implantes e à cicatrização normal (SHAM). Foram utilizados camundongos C57BL/6, constituído de 5 grupos distintos pelo implante subcutâneo dorsal (1cm2): 15 implantados com BLN; 15-LUVA cirúrgica (látex desnaturado); 15-ePTFE (PoliTetraFluorEtileno Expandido - implante sintético) e 15-SHAM. A atividade dos implantes foi avaliada no 2º, 7º e 14º dias, sacrificando 5 animais/grupo/tempo para biópsias (punch-4mm). Toda pele da área implantada foi recortada e fotografada. As amostras foram submetidas a estudos histológicos por HE para contagem das células inflamatórias, fibroplasia e angiogênese, utilizando o plugin \"Cell Counter\" no software ImageJ®; pelo Tricrômio de Gomori para quantificação colagênica pelo \"Threshold\" no ImageJ®, e imunohistoquímica para iNOS, IL-1?, VEGF e TGF-?1. A partir do sobrenadante do macerado das biópsias foram realizadas as dosagens de mieloperoxidase (MPO), IL-1? e de TGF-?1 por ELISA. Macroscopicamente, viu-se maior quantidade de tecido neoformado nos animais implantados com BLN já no 2º dia, diferente dos demais grupos. À histologia (HE), constatou-se que a BLN no 2º dia estimulou denso infiltrado inflamatório, principalmente neutrófilos, seguido de maior produção de MPO e de IL-1?, diferente dos demais tratamentos (P<0,01). Com 7 e 14 dias, a quantidade de IL-1? nos grupos LUVA e SHAM foi maior que a da BLN e do ePTFE, mostrando o equilíbrio no estímulo inicial da atividade inflamatória pela BLN. Quanto a angiogênese, os grupos BLN e LUVA com 7 e 14 dias apresentaram maior formação de vasos que o ePTFE e SHAM. Entretanto, na imunohistoquímica observou-se baixa expressão de VEGF no grupo BLN no 7º e 14º dia. Quanto a fibroplasia, o ePTFE com 7 dias apresentou maior fibroplasia que todos os grupos (P<0,01). No 14º dia, a BLN apresentou maior fibroplasia, embora sem diferença estatística entre os grupos. Quanto à colagênese, pelo ImageJ® (\"Threshold\") por Tricrômio de Gomori, os implantes se comportaram de maneira semelhante, inclusive com o SHAM, exceto no 14º dia que o ePTFE apresentou colagênese maior que a LUVA e BLN (P<0,01). O grupo SHAM apresentou maior concentração de TGF-beta1 que os demais grupos no sétimo dia (P<0,01), semelhante à BLN e à LUVA no 14º, entretanto maior que o ePTFE (P<0,01). Conclui-se que a biomembrana de látex da seringueira Hevea brasiliensis atua significativamente na fase inflamatória da cicatrização, importante no recrutamento neutrofílico para o local, confirmado quantitativamente pela concentração de MPO e IL-beta1 e por imunohistoquímica. Este fato parece influenciar diretamente as fases subseqüentes do processo cicatricial, confirmada pela sua capacidade estimuladora de angiogênese, provavelmente não influenciada por VEGF, e pelo estímulo à fibroplasia independente de TGF-beat1 e sem modificação na produção colagênica.
The natural latex biomembrane (NLB) from Hevea brasiliensis rubber tree, used as dressing in the treatment of human chronic ulcers, has been showed efficient in the debridement and the granulation stimulation, accelerating the healing. Its mechanism of action is still unknown, becoming important to evaluate its activity as implantation in the tissue induction, comparing it with the other implants and with the normal healing (SHAM). Mice C57BL/6, consisting of 5 distinct groups had been used of the dorsal subcutaneous implantation (1cm2): 15 implanted with NLB; 15 with surgical GLOVE (unnatural latex); 15 with ePTFE (expanded polytetrafluorethylene - synthetic implantation) and 15 without implant (SHAM). The activity of the implants was evaluated in 2nd, 7th and 14th days. Five animals for group each time were sacrificed for biopsies with 4mm punch. All skin of the implanted area was cut and photographed. The samples had been submitted to the histology studies for haematoxylin-eosin for counting the inflammatory cells, fibroplasia and angiogenesis, using \"Cell Counter\" plugin in the ImageJ® software; by Gomori\'s thrichrome for collagen quantification using \"Threshold\" in the ImageJ®, and iNOS, IL-beta1, VEGF and TGF-beta1 immunohistochemistry. From the biopsies macerated supernatant, the myeloperoxidase assay had been carried through (MPO), IL-beta1 and of TGF-beta1 by ELISA. Macroscopically, it was observed a big amount of new tissue formed in the NLB implanted animals on 2nd day, different of the other groups. In histological analyze by H&E, it was observed that the NLB in 2nd day stimulated dense inflammatory infiltrated, mainly by neutrophils, followed of bigger production of MPO and IL-beta1, different of the other treatments (P<0,01). After 7 and 14 days, the amount of IL-beta1 in the groups GLOVE and SHAM were greater than the NLB and ePTFE, showing the balance in the initial stimulation of the inflammatory activity by the NLB. About angiogenesis, both groups (NLB and GLOVE) after 7 and 14 days had presented greater formation of vessels than ePTFE and SHAM (P<0,01).However, in the immunohistochemistry was observed a low VEGF expression in the NLB group in 7th and 14th days. Related to fibroplasia, ePTFE after 7 days presented greater fibroplasia than all the groups (P<0,01). In 14th day, the NLB presented an important fibroplasia, even so without statistic difference between the groups. The collagen proliferation evaluated by the ImageJ® (\"Threshold\") applied in Gormori\'s thrichrome stained biopsies, the implants showed similar results, also with the SHAM, except in 14th day that ePTFE presented bigger collagen proliferation than the GLOVE (P<0,01).The SHAM group presented greater concentration of TGF-beta1 than the other groups in the seventh day (P<0,01), equal to the NLB and the GLOVE in 14th, however bigger than ePTFE (P<0,01).In conclusion, natural latex biomembrane (NLB) from Hevea brasiliensis rubber tree acts significantly in the inflammatory phase of the healing process, important in the neutrophilic recruitment to injury local, confirmed quantitatively by MPO and IL-beta1 concentrations and by immuno histochemistry. This fact seems to influence directly the subsequent phases of the healing process, confirmed for its stimulatory capacity of the angiogenesis, probably not influenced by VEGF, and the fibroplasia stimulation independent of TGF-beta1 and without modification in the collagen production.

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Baudoin, Marion. "Impact de la taille des particules de caoutchouc du latex d’Hevea brasiliensis sur leurs propriétés aux interfaces fluides et en feuilles de caoutchouc sec". Electronic Thesis or Diss., Université de Rennes (2023-....), 2024. http://www.theses.fr/2024URENS038.

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Cette thèse vise à approfondir notre compréhension du processus de coagulation des deux catégories de taille de particules de caoutchouc issues du latex d’Hevea brasiliensis et à établir un lien avec les propriétés mécaniques du caoutchouc final. L’originalité réside dans une approche multi-échelle et pluridisciplinaire, englobant l’analyse des particules natives et de leur auto-organisation à l’état liquide, ainsi que les propriétés mécaniques des films secs sous forme de feuilles de caoutchouc (mini ADS). L’étude a été menée sur deux tailles de particules provenant des clones, RRIM600 et PB235. La première partie aux interfaces liquide/air est une nouvelle approche utilisant une cuve de Langmuir, avec un suivi des cinétiques d’adsorption des particules à l’interface à l’aide de techniques complémentaires telles que l’ellipsométrie, la tensiométrie, la rhéologie et la microscopie à angle de Brewster. Les premières étapes de la coagulation et l’organisation des composants des particules ont été observées par microscopie à force atomique. La seconde partie a permis de relier ces organisations aux propriétés mécaniques de feuilles de caoutchouc sec à travers des essais de traction uni axiale. Ce travail ouvre de nouvelles perspectives en reliant les processus moléculaires aux propriétés macroscopiques du caoutchouc naturel, élargissant ainsi les voies de recherche dans ce domaine
The aim of this thesis is to gain a deeper understanding of the coagulation process of the two size classes of rubber particles derived from Hevea brasiliensis latex, and to establish a link with the mechanical properties of the final rubber. The originality lies in a multi-scale, multi-disciplinary approach, covering the analysis of native particles and their self-organization in the liquid state, as well as the mechanical properties of dry films in the form of rubber sheets (mini ADS). The study was carried out on two particle sizes from the RRIM600 and PB235 clones. The first part is a new liquid/air approach using a Langmuir trough, with particle adsorption kinetics at the interface monitored using complementary techniques such as ellipsometry, tensiometry, rheology and Brewster angle microscopy. The first stages of coagulation and the organization of particle components were observed by atomic force microscopy. In the second part, these organizations were linked to the mechanical properties of dry rubber sheets using uniaxial tensile tests. This work opens up new perspectives by linking molecular processes to the macroscopic properties of natural rubber, thus broadening research lines in this field

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Friolani, Milena. "Utilização da biomembrana de látex de seringueira (Hevea brasiliensis) em lesões diafragmáticas de coelhos : estudo experimental /". Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/89027.

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Resumo: Tendo em vista as propriedades de aceleração do processo cicatricial com utilização da biomembrana de látex, este trabalho teve como objetivo avaliar o comportamento de retalho de biomembrana natural de látex, em lesões diafragmáticas induzidas experimentalmente em coelhos. Utilizaram-se 15 coelhos sadios, raça Nova Zelândia, adultos, machos e fêmeas, tendo como acesso ao diafragma, o 8º espaço intercostal direito. Os animais foram divididos, aleatoriamente, em cinco grupos experimentais de três cada, e avaliados diariamente desde o dia da cirurgia até a eutanásia, quanto ao comportamento, freqüência respiratória e cardíaca, cicatrização externa. Os animais foram eutanasiados aos 15, 30, 45, 60 e 90 dias de pós cirúrgico, obtendo-se uma avaliação macroscópica e microscópica do conjunto diafragma/enxerto. Todos os animais apresentaram evolução clínica satisfatória. Macroscopicamente, em todos os grupos experimentais observou-se boa cicatrização na região do implante, com exceção de um dos animais eutanasiados aos quinze dias. Após quinze dias, houve neoformação tecidual, e após trinta dias do ato operatório, em todos animais observou-se aderência do fígado e do pulmão na área de implante. As observações clínico-cirúrgicas complementadas pela análise das alterações histológicas, permitiram concluir pela indicação do emprego da membrana de látex em lesões diafragmáticas reparadoras, em razão da facilidade de obtenção, custo baixo, fácil aplicabilidade, resistência e resposta satisfatória em relação ao tempo de cicatrização.
Abstract: Having in mind the acceleration properties of the cicatricial process by using the latex bio-membrane, the present paper was aimed at evaluating the behavior of the natural latex bio-membrane flap in diaphragmatic lesions experimentally induced in rabbits. Fifteen healthy New Zealand rabbits, adults, males and females were used, having the eighth right intercostal space as an access to the diaphragm. The animals were randomly assigned to five experimental groups, each with three rabbits. They were evaluated daily from the day of surgery to the day of euthanasia in relation to behavior, respiratory and cardiac frequencies and external cicatrization. The animals were euthanized in 15, 30, 45, 60 and 90 days after the surgery and it was obtained a macroscopic and microscopic evaluation of the set diaphragm/graft. All rabbits presented a satisfactory clinical evolution. Macroscopically, in all experimental groups it was observed a good cicatrization of the implant region, except for one animal that was euthanized in 15 days. After fifteen days, there was tissular neo-formation and thirty days after surgery in all animals it was observed the adherence of the liver and lungs in the implant area. The clinical surgical observations complemented by the analysis of histological alterations allowed the conclusion in favor of the indication of using the latex membrane in reparative diaphragmatic lesions because of the easy obtainment, low cost, easy applicability, resistance, and satisfactory response in relation to the cicatrization time.
Orientador: Carlos Roberto Daleck
Coorientadora: Cláudia Sampaio Fonseca Repetti
Banca: Maria Rita Fernandes Machado
Banca: Celso Sanches Braccialli
Mestre

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Caetano, Guilherme Ferreira. "Células mesenquimais estromais multipotentes derivadas do tecido adiposo e fração proteica do látex natural (Hevea brasiliensis) associados à scaffolds de policaprolactona e grafeno na osteogênese experimental". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/17/17138/tde-22082017-171808/.

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Defeitos ósseos assumem importância na crescente prevalência de condições crônicas de saúde, agravando-se conforme o envelhecimento da população. O tratamento convencional baseia-se no transplante autólogo e abordagens extremamente invasivas. Uma proposta promissora é a obtenção de tecidos saudáveis em laboratórios utilizando suportes tridimensionais porosos (scaffolds) que atuarão como arcabouço para o crescimento e diferenciação de células tronco mesenquimais (CTMs) podendo ser otimizados para proporcionar adequada vascularização, uma importante característica na regeneração óssea. CTMs apresentam potencial de diferenciação, imunoregulação e angiogênese. O pico proteico F1 do soro do látex da seringueira Hevea brasiliensis apresenta importante atividade angiogênica e cicatrizante. O objetivo deste trabalho foi investigar a influência de scaffolds de policaprolactona (PCL) colonizados com CTMs na osteogênese experimental in vitro e in vivo (xenotransplante), a segurança e a influência do pico F1 do látex em cultura de CTMs aplicadas no scaffold de PCL e PCL reforçado com diferentes concentrações de grafeno (PCL/grafeno) na proliferação e diferenciação osteogênica. Para isso, as CTMs foram isoladas do tecido adiposo humano (ADSCs), caracterizadas por imunofenotipagem e diferenciação in vitro. Scaffolds de PCL, produzidos por técnica de manufatura aditiva, foram avaliados quanto ao potencial de adesão/viabilidade celular (ensaio MTT), diferenciação osteogênica (vermelho de alizarina) e potencial in vivo de osteointegração e osteoindução em defeito crítico de calvária avaliados por histologia e imunoistoquímica. O pico F1 do látex, em diferentes concentrações, foi avaliado em cultura de ADSCs e fibroblastos 3T3 quanto a citotoxicidade (MTT), potencial proliferativo (timidina-tritiada), migratório (scratch assay) e indução osteogênica (fosfatase alcalina). Scaffolds de PCL foram reforçados com grafeno (PCL/grafeno), revestidos com pico F1 (adsorção), avaliados quanto a viabilidade/proliferação celular (Alamar blue) e diferenciação osteogênica (fosfatase alcalina e vermelho de alizarina). A imunofenotipagem das ADSCs demonstrou baixa percentagem para marcadores negativos, alta para os positivos e diferenciação in vitro, comprovando o sucesso do isolamento e manutenção das ADSCs. O scaffold de PCL apresentou não-toxicidade e diferenciação osteogênica induzida pelo meio de cultura. Scaffolds de PCL, pré-colonizado e não colonizado com ADSCs, foram implantados em defeito crítico de calvária de ratos. O grupo que recebeu scaffolds com ADSCs humanas proporcionou melhor formação óssea no animal, com participação direta e indireta das ADSCs neste processo. Nos ensaios in vitro com o pico F1 (cultura 2D), observou-se estímulo proliferativo para as concentrações de 0.00001% e 0.0001%, além de maior percentagem de migração celular para as concentrações de 0.001%, 0.0001% e 0.00001%, diferentes do controle. Os scaffolds de PCL/grafeno demonstraram estimulo proliferativo quando colonizados por ADSCs e este estímulo foi ainda maior em scaffolds revestidos com F1, principalmente na concentração de 0.75% de grafeno. Embora o pico F1 não tenha potencializado a diferenciação osteogênico em cultura 2D, este estímulo foi observado em scaffolds revestidos com F1 com superior atividade da fosfatase alcalina. Este trabalho demonstrou sucesso no emprego de ADSCs humanas e scaffolds in vitro e in vivo (transplante xenogênico) para regeneração óssea, além de apresentar dois promissores produtos para engenharia tecidual como os scaffolds com reforço de grafeno em baixas concentrações e o pico proteico F1 na proliferação e diferenciação celular.
The increment of life expectancy and frequency of chronic diseases in the population has led to an increasing incidence of chronic bone defects. Conventional treatment is based on autologous transplantation, which depends on extremely invasive approaches. A promising proposal is to obtain healthy tissues in laboratories using porous three-dimensional matriz (scaffolds), which enable cellular growth and differentiation of mesenchymal stem cells (MSCs). Scaffolds can be optimized to provide adequate vascularization, a critical event to bone regeneration. MSCs have potential for differentiation, immunoregulation and angiogenesis. F1 natural latex protein from Hevea brasiliensis rubber tree presents important angiogenic and healing activity. The objective of this work was to investigate the influence of pre-colonized polycaprolactone (PCL) scaffolds on experimental in vitro and in vivo osteogenesis (xenotransplantation) and also the safety and influence of F1 protein on MSCs seeded on PCL and PCL reinforced with different concentrations of graphene scaffolds (PCL/graphene) in cell proliferation and osteogenic differentiation. MSCs were isolated from human adipose tissue (ADSCs), characterized by positive and negative markers and also in vitro differentiation. PCL Scaffolds, produced by an additive manufacturing technique, were evaluated for cell adhesion/viability potential (MTT assay), osteogenic differentiation (alizarin red) and in vivo xenogenic grafting potential for osteointegration and osteoinduction evaluated by histology and immunohistochemistry. F1 latex protein, prepared in different concentrations, was evaluated in contact with ADSCs and 3T3 fibroblasts culture in vitro regarding to cytotoxicity (MTT), proliferative potential (tritiated thymidine), migratory (scratch assay) and osteogenic induction (alkaline phosphatase). PCL scaffolds were reinforced with graphene (PCL/graphene scaffolds), coated with F1 protein (adsorption) and evaluated for cell viability/proliferation assay (Alamar blue) and osteogenic differentiation (alkaline phosphatase and alizarin red). ADSCs showed low percentage for negative markers, high percentage for positive markers and differentiation properties in vitro, providing enough information on the successful isolation and maintenance of human ADSCs. PCL scaffolds showed non-toxicity activity and osteogenic differentiation induced by culture medium. PCL scaffolds, pre-colonized and non-colonized with ADSCs, were implanted in a critical calvarial defect in rats. The group of rats which received scaffolds with ADSCs to treat the bone defect had improved bone formation with direct and indirect participation of ADSCs to the bone repair process. To in vitro assays with F1 (2D culture model), proliferative stimulus was observed to F1 0.00001% and 0.0001% samples, in addition to a higher percentage of cell migration to 0.001% and 0.0001%, different from control. PCL/graphene scaffolds demonstrated proliferative stimulation when colonized by ADSCs and this stimulus was even higher to F1 coated PCL/graphene scaffolds, mainly to 0.75% graphene. Although F1 have not enhanced osteogenic differentiation on 2D cell culture model, the stimulus was observed to F1 coated scaffolds with higher alkaline phosphatase activity. This work demonstrated success in the use of ADSCs and scaffolds for bone regeneration and presented two promising products to be applied in tissue engineering field, such as, scaffolds with graphene reinforcement at low concentration and F1 latex protein to improve cell proliferation and differentiation.

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Pujade-Renaud, Valérie. "Recherche de marqueurs moleculaires de la production de latex et de sa stimulation par l'ethylene chez hevea brasiliensis". Paris 11, 1993. http://www.theses.fr/1993PA112508.

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L'apport d'ethylene sous forme d'ethephon stimule la production de caoutchouc chez hevea brasiliensis, en prolongeant l'ecoulement du latex lors de la saignee et en stimulant le metabolisme implique dans la regeneration du latex. La recherche de marqueurs moleculaires de la production de latex nous a conduits a etudier l'effet de l'ethylene sur l'expression des genes dans les laticiferes. La technique de traduction in vitro a permis de demontrer que l'expression de plusieurs genes etait specifiquement modifiee par l'ethylene, dans le sens d'une stimulation pour certains et d'une repression pour d'autres. En se basant sur les connaissances physiologiques et biochimiques concernant les laticiferes ainsi que sur les donnees bibliographiques concernant les genes sous controle de l'ethylene dans d'autres systemes vegetaux, une selection de sondes a ete realisee puis testee par hybridation en northern blot. Huit sondes ont donne un signal d'hybridation sans ambiguite. Les sondes codant pour une superoxyde dismutase a noyau mn, une chitinase, une heveine, une glutamine synthetase, une glycin rich protein et une extensine ont revele une accumulation des messagers correspondants dans le latex. Les niveaux de transcrits reveles par les sondes codant pour une calmoduline et une proteine kinase ne sont pas modifies. La glutamine synthetase (gs) a ete plus particulierement etudiee. Une banque d'adnc de latex issu d'arbres traites a l'ethephon a ete construite. Un clone isole par criblage de la banque au moyen d'une sonde heterologue de gs a ete sequence et s'est avere correspondre a un clone pleine longueur codant pour une gs cytosolique

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Pagnano, Leonardo de Oliveira [UNESP]. "Análise da cicatrização na pele de coelhos após tratamentos de feridas com biomateriais associados à fração de proteína do látex natural da seringueira (Hevea brasiliensis)". Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/101102.

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Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-30Bitstream added on 2014-06-13T18:41:44Z : No. of bitstreams: 1 pagnano_lo_dr_jabo.pdf: 626602 bytes, checksum: 91e708f2a8ad849761e7177151a3d66e (MD5)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
O objetivo deste trabalho foi avaliar o potencial de cicatrização de uma fração de proteína extraída do látex da seringueira em diferentes concentrações (0,01% e 0,001%) associada a diferentes biomateriais (Fibracol plusÒ e ácido hialurônico a 1%). Utilizaram-se 36 coelhos albinos da raça Nova Zelândia Branco submetidos à realização de 4 feridas em cada orelha. Dividiu-se o experimento em etapas de acordo com a análise do período pós-operatório (3º, 7º, 14º e 21º dias), sendo utilizados 9 animais para cada etapa. Na primeira etapa (3º dia de pósoperatório), os animais foram numerados aleatoriamente de 1 a 9, sendo que em 3 animais, nas orelhas esquerdas, as feridas foram tratadas com solução salina (T1) e nas orelhas direitas, as feridas foram tratadas com membrana de Fibracol plus® + FrHb1 a 0,01% (T2). Em outros 3 animais, realizaram-se os mesmos procedimentos, diferenciando os tratamentos, onde nas feridas das orelhas esquerdas o tratamento foi com Fibracol plus® (T3) e nas feridas das orelhas direitas Fibracol plus® + FrHb1 a 0,001% (T4). Nos 3 animais restantes, seguiram-se os mesmos procedimentos, inserindo nas feridas das orelhas esquerdas ácido hialurônico a 1% + FrHb1 a 0,01% (T5) e nas feridas das orelhas direitas ácido hialurônico a 1% + FrHb1 a 0,001% (T6). Os animais foram sacrificados no 3º dia de pós-operatório e as feridas foram analisadas macroscopicamente e em seguida separadas para a análise histológica. Estes procedimentos foram repetidos para as etapas de 7, 14 e 21 dias de pós-operatório. Os segmentos de tecidos com as feridas foram fixados em solução de Bouin por 24 horas, e processados rotineiramente, para inclusão em paraplast e posterior avaliação histológica e morfométrica. A morfometria foi realizada por meio do sistema...
The aim of this study was to evaluate the potential for healing of a fraction of protein extracted from the latex of rubber trees in different concentrations (0.01% and 0.001%) associated with various biomaterials (Fibracol plus®1 and hyaluronic acid to 1%). There were used 36 New Zealand White rabbits underwent achievement of 4 wounds on each ear. The experiment was divided into stages according to the analysis of the postoperative period (3, 7, 14 and 21 days), and 9 animals used for each step. In the first stage (day 3 post-surgery), animals were randomly numbered from 1 to 9, with 3 animals in the left ear, the wounds were treated with saline (T1) and the right ear, the wounds were treated with membrane of Fibracol plus® + FrHb1 to 0.01% (T2). In 3 other animals, the same procedures were held, differing treatments, where the wounds of the left ear they were treated with Fibracol plus® (T3) and the wounds of the right ears Fibracol Plus® + FrHb1 to 0.001% (T4). In the 3 remaining animals, there was followed by the same procedures, including the ears wounds hyaluronic acid at 1% + FrHb1 to 0.01% (T5) and right ears wounds of hyaluronic acid 1% + FrHb1 a 0.001% (T6). The animals were sacrificed at 3 days postoperatively and the wounds were examined macroscopically and then separated for histological analysis. These procedures were repeated on the steps of 7, 14 and 21 days postoperatively. The segments of the injured tissues were fixed in Bouin solution for 24 hours and routinely processed for inclusion in paraplastic and subsequent histologic and morphometric evaluation. The morphometry was performed using the image analyzing system (Image Pro-PLUS2) and the evaluation of healing was done by enumeration of leukocytes and fibroblasts. The data were subjected to statistical analysis (ANOVA and Tukey test at 5%)... (Complete abstract click electronic access below)

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Lacrotte, Régis. "Etude des relations entre la teneur en sucres du latex et la production : approche des mécanismes du chargement en saccharose des laticifères d'"Hevea brasiliensis" Muell. Arg". Montpellier 2, 1991. http://www.theses.fr/1991MON20245.

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La teneur en saccharose du latex de l'hevea est dependante d'un certain nombre de facteurs lies au systeme d'exploitation des arbres. En fonction de la mise en saignee, de la frequence de saignee, de la position de l'encoche sur le tronc, de la stimulation hormonale et de la saison, la concentration en saccharose du latex subit des variations qui sont le reflet de sa disponibilite apoplastique, de son chargement et de son utilisation in situ. Des correlations directes sucre-production ont ete montrees: a une forte teneur en saccharose correspond une forte production et vice versa. Le saccharose est donc un des facteurs majeurs pouvant limiter la production. Si les voies de l'utilisation du saccharose dans les laticiferes sont maintenant bien connues, une etude du chargement intralaticifere du sucre s'est averee necessare afin d'en comprendre le ou les mecanismes. Les resultats de cette etude, menee tant in situ (sur l'ecorce de l'arbre, par marquage radioactif) que in vivo (sur des fragments de tissus, par des techniques electrophysiologiques) demontrent que le transport du saccharose dans les laticiferes est, pour une grande part, de type actif. Il peut etre freine par des inhibiteurs metaboliques (fna, dnp, van, des), exalte par l'ethylene exogene. Il peut etre attribue a une atpase plasmalemmique creant un gradient electrochimique de protons. Le mecanisme de transport propose est un co-transport (symport) saccharose-h#+, dependant du fonctionnement de la pompe a protons plasmalemmique, sensible directement ou non a l'ethylene

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Pagnano, Leonardo de Oliveira. "Análise da cicatrização na pele de coelhos após tratamentos de feridas com biomateriais associados à fração de proteína do látex natural da seringueira (Hevea brasiliensis) /". Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/101102.

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Orientadora: Silvana Martinez Baraldi Artoni
Banca: Isabel Cristina Boleli
Banca: Antônio Carlos Alessi
Banca: Joaquim Coutinho Netto
Banca: João José Lachat
Resumo: O objetivo deste trabalho foi avaliar o potencial de cicatrização de uma fração de proteína extraída do látex da seringueira em diferentes concentrações (0,01% e 0,001%) associada a diferentes biomateriais (Fibracol plusÒ e ácido hialurônico a 1%). Utilizaram-se 36 coelhos albinos da raça Nova Zelândia Branco submetidos à realização de 4 feridas em cada orelha. Dividiu-se o experimento em etapas de acordo com a análise do período pós-operatório (3º, 7º, 14º e 21º dias), sendo utilizados 9 animais para cada etapa. Na primeira etapa (3º dia de pósoperatório), os animais foram numerados aleatoriamente de 1 a 9, sendo que em 3 animais, nas orelhas esquerdas, as feridas foram tratadas com solução salina (T1) e nas orelhas direitas, as feridas foram tratadas com membrana de Fibracol plus® + FrHb1 a 0,01% (T2). Em outros 3 animais, realizaram-se os mesmos procedimentos, diferenciando os tratamentos, onde nas feridas das orelhas esquerdas o tratamento foi com Fibracol plus® (T3) e nas feridas das orelhas direitas Fibracol plus® + FrHb1 a 0,001% (T4). Nos 3 animais restantes, seguiram-se os mesmos procedimentos, inserindo nas feridas das orelhas esquerdas ácido hialurônico a 1% + FrHb1 a 0,01% (T5) e nas feridas das orelhas direitas ácido hialurônico a 1% + FrHb1 a 0,001% (T6). Os animais foram sacrificados no 3º dia de pós-operatório e as feridas foram analisadas macroscopicamente e em seguida separadas para a análise histológica. Estes procedimentos foram repetidos para as etapas de 7, 14 e 21 dias de pós-operatório. Os segmentos de tecidos com as feridas foram fixados em solução de Bouin por 24 horas, e processados rotineiramente, para inclusão em paraplast e posterior avaliação histológica e morfométrica. A morfometria foi realizada por meio do sistema... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The aim of this study was to evaluate the potential for healing of a fraction of protein extracted from the latex of rubber trees in different concentrations (0.01% and 0.001%) associated with various biomaterials (Fibracol plus®1 and hyaluronic acid to 1%). There were used 36 New Zealand White rabbits underwent achievement of 4 wounds on each ear. The experiment was divided into stages according to the analysis of the postoperative period (3, 7, 14 and 21 days), and 9 animals used for each step. In the first stage (day 3 post-surgery), animals were randomly numbered from 1 to 9, with 3 animals in the left ear, the wounds were treated with saline (T1) and the right ear, the wounds were treated with membrane of Fibracol plus® + FrHb1 to 0.01% (T2). In 3 other animals, the same procedures were held, differing treatments, where the wounds of the left ear they were treated with Fibracol plus® (T3) and the wounds of the right ears Fibracol Plus® + FrHb1 to 0.001% (T4). In the 3 remaining animals, there was followed by the same procedures, including the ears wounds hyaluronic acid at 1% + FrHb1 to 0.01% (T5) and right ears wounds of hyaluronic acid 1% + FrHb1 a 0.001% (T6). The animals were sacrificed at 3 days postoperatively and the wounds were examined macroscopically and then separated for histological analysis. These procedures were repeated on the steps of 7, 14 and 21 days postoperatively. The segments of the injured tissues were fixed in Bouin solution for 24 hours and routinely processed for inclusion in paraplastic and subsequent histologic and morphometric evaluation. The morphometry was performed using the image analyzing system (Image Pro-PLUS2) and the evaluation of healing was done by enumeration of leukocytes and fibroblasts. The data were subjected to statistical analysis (ANOVA and Tukey test at 5%)... (Complete abstract click electronic access below)
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Kerche, Silva Leandra Ernst [UNESP]. "Avaliação in vitro e in vivo da capacidade antioxidante e antitumoral da fração C do látex de Hevea brasiliensis RRIM 600". Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/148926.

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Biomateriais podem ser definidos como dispositivos que entram em contato com sistemas biológicos tanto na forma de sólidos quanto de líquidos e géis. Para um novo biomaterial, são necessários testes toxicológicos e de interação in vitro e in vivo. O látex é uma substância branca e leitosa que exsuda da casca da Hevea brasiliensis quando a mesma é perfurada e que tem sido apontado como um biomaterial promissor. O látex quando centrifugado em alta velocidade é separado em três frações: a fração com partículas de borracha, uma fração aquosa chamada fração C e uma fração de fundo chamada fração B. A fração C é a fração metabolicamente ativa do látex. Assim, o presente estudo investigou os potenciais efeitos antioxidantes, citotóxicos, genotóxicos e antitumorais da fração C do látex da Hevea brasiliensis. Para isso, foram utilizados os testes de sequestro de radicais livres e capacidade antioxidante total em meio in vitro sem células; o teste do MTT, o ensaio do cometa, avaliação de morte celular com coloração com Hoechst 33342 e Iodeto de Propídio (PI) e avaliação de parâmetros bioquímicos de estresse oxidativo em meio in vitro com duas linhagens celulares, a CHO-k1, linhagem de células normais de epitélio de ovário de hamster, e a B16F10, linhagem de células de melanoma murino; e a ação da fração C na indução de carcinoma de células escamosas (SCC) em camundongos SKH-1 por exposição crônica à radiação UVB. Nossos resultados mostraram que a fração C é antioxidante, com capacidade para sequestrar os radicais HO• e NO• e o H2O2. A fração C não alterou a viabilidade celular das células CHO-k1, não induziu danos no DNA dessas células, não induziu apoptose e necrose e nem alterou a quantidade de tiol total e de malonaldeído (MDA) nessas células. No entanto, para a linhagem celular B16F10, a fração C mostrou atividade antitumoral, reduzindo a viabilidade celular, induzindo danos no material genético, induzindo morte celular e alterando os níveis de tiol e MDA nessas células. Nos animais que foram expostos cronicamente à radiação UVB, a fração C protegeu os eritrócitos e a pele dos animais do estresse oxidativo promovido pela irradiação e protegeu as células da pele de transformação maligna para SCC. Em resumo, nossos resultados mostraram que a fração C do látex da H. brasiliensis apresenta propriedades terapêuticas antioxidantes e antitumorais.
Biomaterials can be defined as devices that come in contact with biological systems in the form of solids, liquids and gels. In vitro and in vivo toxicological tests are needed for a new biomaterial to come out. Latex is a white and milky solution that exsudes from Hevea brasiliensis bark when perforated, and it has been appointed as a new promising biomaterial. When centrifuged in high speed, latex can be separated in three parts: rubber particle fraction, aqueous C-serum fraction and a bottom fraction called B-serum. Cserum is the part that is metabolically active. In this way, the aim of this work was to investigate potential antioxidant, cytotoxic, genotoxic and antitumor effects of latex Cserum from Hevea brasiliensis. For this purpose, we used in vitro free-radical scavenger and total antioxidant capacity tests; MTT test, comet assay, staining with Hoechst 33342 and Propidium Iodide (PI) to evaluate cell death, and evaluation of biochemical parameters of oxidative stress in Chinese hamster ovary epithelium normal cell line, CHO-k1, and murine melanoma cell line, B16F10; and C-serum effects in the induction of squamous cell carcinoma (SCC) in SKH-1 mice by chronic UVB exposure. Our results show that latex C-serum is an antioxidant compound that was able to scavenge HO• and NO• radicals and H2O2. C-serum did not alter the cell viability in CHO-k1 cells and it did not promote DNA damage in these cells, it did not alter the levels of apoptotic and necrotic cells for this cell lineage and did not alter total thiol and MDA levels in these cells. However, for B16F10 cells, latex C-serum presented antitumor effect, reducing cell viability, inducing DNA damage and cell death, and altering total thiol and MDA levels in these cells. In the animals chronically exposed to UVB radiation, latex C-serum protected the erythrocytes and skin cells from oxidative stress promoted by the irradiation, and prevented skin cells from malignant transformation to SCC. In summary, this work shows that latex C-serum from Hevea brasiliensis present antioxidant and antitumor therapeutic properties.

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Musigamart, Natedao. "Study of the role of lipids from maturated coagula from Hevea brasiliensis latex on natural rubber behavior in oxidative conditions". Thesis, Montpellier, SupAgro, 2015. http://www.theses.fr/2015NSAM0004/document.

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Le caoutchouc naturel (CN), un produit dérivé du latex d'Hevea brasiliensis, est connu pour ses propriétés mécaniques supérieures pour certaines à celles de ses concurrents synthétiques. Néanmoins, le haut degré d'insaturation du poly(cis-1,4-isoprene) le rend susceptible à la thermo-oxydation. Heureusement, le CN est doté de composés non-isoprènes dont certains ont des propriétés antioxydantes. Les lipides sont les plus importants non-isoprènes retenus dans le caoutchouc et contiennent des molécules à activité antioxydante en particulier les tocotriènols. Il est connu que durant la maturation de coagula de latex, la composition chimique et les propriétés du caoutchouc obtenu sont altérées, mais les mécanismes complexes de cette altération ne sont pas encore complètement élucidés. Dans cette étude, l'évolution de certaines molécules antioxydantes natives pendant la maturation a été suivie en relation avec certaines propriétés physiques du caoutchouc. Deux expérimentations de maturation ont été mises en œuvre. La première mettait en jeu des conditions non contrôlées de maturation suivies d'un procédé de confection du caoutchouc basé sur celui des feuilles fumées (RSS) ou non (USS). La seconde a été conduite dans un dispositif expérimental dédié permettant le contrôle des facteurs de l'environnement tels que l'humidité relative, la température et la concentration en oxygène. Le procédé de confection du caoutchouc était dans ce cas basé sur celui des caoutchoucs spécifiés techniquement (TSR). L'évolution des échantillons pendant la maturation a été étudiée à différentes échelles : propriétés en masse (P0, P30 et PRI), mésostructure (% gel, Mw and Mn) et composition biochimique (lipides). En parallèle, l'activité antioxydante in vitro des extraits lipidiques correspondants a été mesurée en utilisant une méthode DPPH optimisée. La quantité et la qualité des lipides extraits évoluent pendant la maturation, en particulier en aérobiose. La quantité totale de lipides décroit, avec, en début de maturation, une libération d'acides gras dont la quantité diminue ensuite, avec une disparation des espèces insaturées en premier. La quantité de γ-tocotrienol libres extraits change peu au cours de la maturation alors que sa forme estérifiée montre un enrichissement en acides gras saturés. L'activité antioxydante de l'extrait lipidique mesurée in vitro est corrélée avec la concentration de γ-tocotrienol libre mais pas avec les valeurs de P30 et PRI qui estiment la résistance du caoutchouc à la thermo-oxydation. Cette absence de corrélation pourrait être due à la différence des conditions de mesure in-vitro de celles existantes au sein du matériau caoutchouc. La localisation des antioxydants dans le caoutchouc et en particulier leur possibilité physique d'interagir avec les doubles liaisons du poly(cis-1,4-isoprene) ou avec des espèces oxydantes reste à étudier afin de comprendre ce qui régit la chute de P30 au cours de la maturation. Des lipides non extractibles ou des molécules non-isoprènes plus polaires (protéines, polyphénols, …) pourraient également influencer la résistance du caoutchouc à la thermo-oxydation
Natural rubber (NR), a derived product from H. brasiliensis latex, is known for its high mechanical properties that are, for some, superior to those of its synthetic counterparts. However, the high degree of unsaturation of poly(cis-1,4-isoprene) makes it susceptible to thermo-oxidation. Fortunately, NR is endowed with non-isoprene components of which some have antioxidant properties. Especially, lipids, the main non-isoprene component retained in NR, have been reported to contain antioxidant substances, especially tocotrienols. It is well known that during the maturation of latex coagula, both NR physical properties and chemical composition are altered, but the complex mechanisms of this alteration are still to be elucidated. In the present work, the evolution of some native antioxidant molecules during maturation was followed in relation with some physical properties. Two experimental conditions of maturation were chosen. The first experiment involved uncontrolled conditions based on traditional unsmoked (USS) or ribbed smoked sheet (RSS) processing, while the second was performed in a dedicated maturation device with full control of environmental factors (relative humidity, temperature and oxygen content) followed by a processing based on that of Technically Specified Rubber (TSR). The evolution of samples during maturation was studied at different scales: bulk properties (P0, P30 and PRI), mesostructure (% gel content, Mw and Mn) and biochemical composition (lipids components). In parallel, in vitro antioxidant activity of NR lipid extracts was also investigated using an optimized DPPH method. Lipid quantity and quality evolved during maturation, especially under aerobic conditions. The total amount of lipid extract decreased, with a release of free fatty acids at early stage of maturation followed by a later decrease, unsaturated fatty acids being the first to disappear. The amount of extractable free γ-tocotrienol did not change much during maturation, while its esterified form was enriched in saturated fatty acids. The antioxidant activity measured in vitro correlated well with free γ-tocotrienol concentration but not with the resistance of rubber to thermo-oxidation assessed by P30 or PRI. Indeed, the in vitro conditions of measurement were far from those occurring inside rubber material. The localization of antioxidants in rubber and especially their physical possibility to interact with the double bonds of poly(cis-1,4-isoprene) or with oxidant species should be further investigated to understand what drives the drop of P30 along maturation time. Non extractable lipids or more polar non-isoprene molecular species (proteins, polyphenols, etc…) could also influence the resistance to thermo-oxidation

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Dusotoit-Coucaud, Anaïs. "Caractérisations physiologique et moléculaire des transporteurs de sucres et de polyols des cellules laticifères chez "Hevea brasiliensis", en relation avec la production de latex". Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2009. http://tel.archives-ouvertes.fr/tel-00725589.

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L'hévéa est un arbre qui revêt un fort intérêt à l'échelle mondiale. Il représente la seule source de caoutchouc naturel commercialement exploitée. La demande grandissante de cette matière première a conduit à l'initiation de nombreuses recherches visant à augmenter la production de latex. La biosynthèse du caoutchouc à partir du saccharose se déroule dans le cytoplasme (latex) des cellules laticifères, hétérotrophes et dépourvues de plasmodesmes, les cellules laticifères disposeraient d'un équipement membranaire de transporteurs actifs spécifiques, afin de répondre à leurs besoins importants en photoassimilats.Toutefois, le rôle de ces transporteurs dans la physiologie des cellules laticifères n'a jamais été élucidé. Ce travail propose la première étude moléculaire des co-transporteurs H+ / sucres solubles et H+ / polyol (quebrachitol) au sein des cellules laticifères, en relation aves la production de latex. Ce travail a permis l'identification des premiers co-transpoteurs de saccharose d'hexoses et de polyols chez l'hévéa. Dix gènes de trasporteurs ont été clonés dans les cellules laticifères : 7 transporteurs putatifs de saccharose (HbSUT1A, HbSUT B, HbSUT2A, HbSUT2B, HbSUT2C, HbSUT4, HbSUT5), 1 transporteur putatif d'hexoses (HbHXT1) et 2 transporteurs putatifs de polyols (HbPLT1, HbPLT2). Ensuite les caractérisations physiologiques et moléculaires fines de ces transporteurs ont permis la mise en evidence du rôle potentiel et complémentaire de HbSUT1B, HbHXT1et HbPLT2 dans la production de latex, HbSUT1B et HbHXT1 seraient impliqués dans la régulation de la régénération du latex, alors que HbPLT2 interviendrait dans le contrôle de l'écoulement. Ces trois gènes sont proposés en tant que marqueurs moléculaires potentiels de production.

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Alves, Maxley Martins. "INFLUÊNCIA DO SORO LÁTEX NATURAL DA SERINGUEIRA Hevea Brasiliensis SOBRE A RESPOSTA INFLAMATÓRIA AGUDA INDUZIDA POR SEPSE: ESTUDO EXPERIMENTAL EM RATOS". Pontifícia Universidade Católica de Goiás, 2014. http://localhost:8080/tede/handle/tede/2985.

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The acute inflammatory answer is a manifestation of the organism triggered by an infectious or non-infectious taunting. Predisposal factors are, for instance: bacteria, viruses, amongst other microorganisms or traumas. It is an internal survival mechanism. The development of a cascade of immunological events in an attempt of destroying an aggressive agent, with cardiologic, hemodynamic, respiratory, renal, endocrine, metabolic, gastrointestinal and hematological alterations occurs determining a syndrome clinic case. Vascular and immunological alterations trigger a counter balance inflammatory response. Recent researches using a specific derived fraction of the natural gum of Hevea brasiliensis rubber tree, called Hev b 13, has shown induction capability to synthesize interleukin 10 (IL-10) in vitro, stimulating the anti-inflammatory response that may result in homeostasis. These evidences are assessed with high mortality sepis induction, after surgical procedure with gastric, intestinal and pancreatic damaging and strain infusion of Acinetobacter baumanni of resistance profile to multiple antibiotics tested. In dose 0,5 mg/kg of Hev b 13 solution, subcutaneous, similarities were observed in the survival of animals treated with this solution and the control group, treated with 1 ml of SF0, 9% (p= 0,8106). The laboratorial analysis, on the other hand, showed total leukocytes reckoning (p = 0,0207) and total lymphocyte (p= 0,0032) with statistically significant differences. In further counting there was no significant difference (p>0,05). The Hev b 13 solution may lead to the induction of reducing the amplification of immunological cellular cascade, reducing the production of total leukocytes and lymphocytes, with effect over the immunological response, anti-inflammatory effect. The experiment induced synthesis of interleukin-10 (IL-10) and tumor necrosis factor (TNF). Rats receiving Hev b 13, lung tissue showed lesser involvement of inflammatory cells.
A resposta inflamatória aguda é uma manifestação do organismo desencadeada por um insulto. Fatores que predispõem são, por exemplo: bactérias, vírus, dentre outros micro-organismos ou traumas. É um mecanismo interno de sobrevivência. A resposta inflamatória leva ao desenvolvimento de uma cascata de eventos imunológicos na tentativa de destruir o agente agressor, com alterações cardiológicas, hemodinâmicas, respiratórias, renais, endocrinometabólicas, gastrointestinais e hematológicas determinando um quadro clínico sindrômico. As alterações vasculares e imunológicas desencadeiam uma resposta de contra-balanço inflamatória. Pesquisas recentes utilizando uma fração específica derivada do látex natural da seringueira Hevea brasiliensis, denominada Hev b 13, tem mostrado capacidade de induzir síntese de interleucina 10 (IL-10) in vitro, estimulando a resposta anti-inflamatória, podendo resultar em homeostase. Estas evidências são avaliadas no modelo experimental adotado com indução de sepse grave, após procedimento cirúrgico com lesões gástrica, intestinal e pancreática, além de infusão de cepas de Acinetobacter baumanni com perfil de resistência a múltiplos antibióticos testados. Foi infundido solução Hev b 13 via subcutânea na dosagem 0,5 mg/Kg. Observou-se semelhança na sobrevida dos animais que foram tratados com esta solução e os animais do grupo controle, tratados com 1 ml de SF0,9% (p =0 ,8106). A contagem de leucócitos totais (p= 0,0207) e linfócitos totais (p= 0,0032) apresentou diferenças estatisticamente significativas. Nas demais células as contagens não apresentaram diferença estatística significativa (p>0,05). A solução de Hev b 13 pode induzir a redução da amplificação da cascata celular imunológica, reduzindo a produção de leucócitos e linfócitos totais, modulando a resposta imunológica. O experimento realizado induziu síntese de interleucina 10 (IL-10) e Fator de necrose tumoral (TNF). Os ratos que receberam Hev b 13, apresentaram no tecido pulmonar menor envolvimento de células inflamatórias.

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Reis, Guilherme de Oliveira. "Study of the mechanism of acid coagulation of Hevea latex and of the rheological properties of resulting gels". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS227/document.

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Latex d’Hevea brasiliensis est composé principalement de particules de caoutchouc dont le noyau est constitué de cis-1,4-polyisoprène et la membrane de composés dit non-isoprène. Sa stabilité dans l'arbre est assurée par les charges négatives de la membrane en raison de la présence de protéines et de lipides. Le latex d’Hevea brasiliensis coagule après acidification pour former un gel colloïdal qui est la première étape de sa transformation en caoutchouc naturel.Dans cette thèse, nous avons étudié l’agrégation et la gélification induite par ajout d’un acide et les propriétés des gels obtenus. Pour cela, un latex de caoutchouc naturel commercial constitué par des particules de caoutchouc (1 µm de diamètre), a été utilisée. L'agrégation a été induite par l'hydrolyse d'un composé appelé glucano-delta-lactone (GDL). Cette agrégation a été suivie par différentes techniques basées sur la diffusion de la lumière (turbidimétrie, DWS, SLS). La gélification a été suivie in situ par la rhéologie. Ensuite, les propriétés rhéologiques de gels colloïdaux formés à pH 4 ont été caractérisées dans les régimes linéaires et non-linéaires.La dépendance à la fraction volumique et le pH de l'apparition de l'agrégation ont été observée. La non-redispersion des agrégats montre les interactions fortes entre les particules de caoutchouc. Trois comportements d’état différents (solution stable, la séparation de phase et gel) peuvent être prédits à partir d'un diagramme d’état fraction volumique-pH qui a été établi pendant 5 semaines. L'état de gel présente une structure fractale, caractérisé par une relation de loi de puissance entre le module élastique G' et la fraction volumique. Pour des fortes déformations, une réorganisation irréversible sous contrainte a abouti à un durcissement irréversible du matériau. Nous avons observé par rheo-ultrasound qu'au-dessus de 50% de déformation, une déstructuration homogène est produite dans le gel
Natural rubber latex is mainly composed by rubber particles whose core is made of cis-1,4-polyisoprene and the shell of non-isoprene compounds. It stability in the tree is provided by the negative charge of the shell due to the presence of proteins and lipids. Natural rubber latex coagulates after acidification to form a colloidal gel that is the first step of its transformation into natural rubber.In this PhD thesis, we studied this acid-induced aggregation and gelation and the properties of the resulting gels. For this, a commercial natural rubber latex composed by rubber particles (1 µm in diameter), was used. Aggregation was induced by hydrolysis of a compound called glucano-delta-lactone (GDL). The aggregation was followed by different techniques based on light scattering (turbidimetry, DWS, SLS). Gelation was followed in situ by rheology. Then, the rheological properties of colloidal gels formed at pH 4 were characterized in the linear and non-linear regimes.Dependence to the volume fraction and the pH of the onset of aggregation was observed. The non-redispersion of aggregates proves the strong interactions between rubber particles. Three different state behaviors (stable solution, phase separation and gel) can be predicted from a state diagram pH-volume fraction that was established over 5 weeks. The gel state exhibits a fractal structure, characterized by a power law relationship between the elastic modulus G’ and the volume fraction. At high deformations, an irreversible reorganization under stress resulted in an irreversible strain hardening of the material. We observed by rheo-ultrasound that above 50% deformation, an homogenous destructuration occurred in the gel

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Frade, Marco Andrey Cipriani. "Úlcera de perna: caracterização clínica e perfil imunohistopatológico da cicatrização na presença da biomembrana de látex natural da seringueira Hevea brasiliensis". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/17/17138/tde-17042012-215000/.

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Úlcera de perna é uma doença muito freqüente na população idosa. Inúmeros são os tipos de curativos atualmente usados para tratamento das úlceras de perna, com diferentes indicações, vantagens e desvantagens, cuja eficácia não está bem esclarecida devido à descontinuidade dos tratamentos e os custos envolvidos em algumas situações. Para avaliar a ação da biomembrana de látex (BML) no tratamento de úlceras de perna, que se comportou como eficiente indutora do tecido de cicatrização. Foram realizadas avaliações clínicas e imunohistopatológicas em 21 doentes, casualmente selecionados, submetidos à aplicação da biomembrana (14 pacientes), comparando com o tratamento clássico (07 pacientes) constituído de pomada com cloranfenicol e enzimas proteolíticas (Fibrase) com o objetivo de analisar e comparar as alterações histopatológicas e imunohistoquímicas relacionadas aos diferentes tratamentos. Foram coletadas biópsias da lesão antes e 30 dias após os tratamentos. As biópsias foram divididas em dois fragmentos, um deles para o estudo histopatológico e outro congelado a -70°C para análise imunohistoquímica. Os resultados mostram que o uso da biomembrana de látex facilitou os cuidados à lesão aliada ao baixo custo e praticidade de sua aplicação. Adicionalmente, foi observado que a BML induz a uma diferenciação clínica e histopatológica do tecido de cicatrização, com aumento da detecção de fatores de crescimento como VEGF (vascular endothelial growth factor) e TGF1(transforming growth factor 1), associada à redução da expressão da enzima iNOS (óxido nítrico-sintase induzida), quando comparado ao tratamento controle. A análise global dos dados sugere que o tratamento com a biomembrana conduz a organização do tecido cicatricial conseqüente à maior produção de fatores de crescimento celular. Dessa forma, a biomembrana se caracteriza como uma boa opção terapêutica para úlcera de perna, devido à praticidade de sua aplicação, baixo custo e alta potencialidade na indução da cicatrização.
The leg ulcer is a disease very frequent in elderly people. Nowadays, there are many kinds of dressing to treat its with different indications, advantage and disadvantage. Their efficacy is not clear yet because to the treatments discontinuous and the costs involved in same situations. The latex biomembrane from rubber tree Hevea brasiliensis (NLB) showed an improvement of the healing process to treat leg ulcer, observed by the clinical and the immune histopathological aspects. To verify whether the NLB could be associated with an increased healing we selected 21 leg ulcer patients to be submitted to the topical treatment. These patients were divided into two groups. In the first group 14 randomized patients were treated with latex biomembrane and in the other group 07 patients were treated with topical ointment of cloranfenicol and proteolitic enzymes with the objectives to analyze and to compare the histopathological and immunohistochemical alterations related to the different treatments. All the patients were submitted at least to two biopsies; before the treatment and the 30th day of the treatment. The biopsies specimens were divided into two parts; one of them for the histopathological study and the other was frozen for the immunohistochemical analysis. The results showed that the biomembrane is very easy, practical and cheap leg ulcer topical treatment. Additionally, the NLB induces to a clinical and hystopathological differentiation of the cicatrization tissue with increased detection of growth factors as VEGF (vascular endothelial growth factor) and TGF-1(transforming growth factor1), associated to a reduction of iNOS (induced oxide nitric sintase) expression when compared to the control treatment. The global analyze of the data suggest that the biomembrane of natural latex led to cicatricial tissue organization and a higher production of cellular growth factors. So, this treatment can characterize as a good therapeutic option for leg ulcers due the facility of the application, low costs and high potentiality to induce of the cicatrization.

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Zhang, Yi. "Identification des gènes impliqués dans la production et la détoxication des espèces activées de l'oxygène chez Hevea brasiliensis et leur caractérisation dans le latex". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTG004/document.

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Hevea brasiliensis, un arbre tropical, est la source principale de caoutchouc naturel commercialement viable. La biosynthèse de caoutchouc se passe dans les cellules spécialisées appelées laticifères. Il représente jusqu’à 90% de la matière sèche du latex. Le latex, laiteux, s’écoule de l’encoche faite sur l’écorce de l’arbre jusqu’aux cellules laticifères. La collecte de latex, faite par saignée régulière tous 2-3 jours, est vraiment stressante pour l’arbre. Pour stimuler la production de latex, un générateur d’éthylène peut être appliqué sur le panneau de saignée. Le stress s’intensifie avec l’application hormonale. La production d’espèces activées de l’oxygène (ROS) se fait en réponse aux stress environnementaux ainsi que lors de l’exploitation de l’arbre. Au-delà d’un certain seuil, la production de ROS est massive dans les laticifères. De nombreuses études ont montré que les ROS entraîne une dégradation par peroxydation des lipides insaturés des membranes et ensuite une déstabilisation et lyse des organites. La lyse des lutoïdes permet la libération des facteurs de coagulation dans le latex entraînant la coagulation in situ des particules de caoutchouc dans l’écorce des arbres stressés. Ce syndrome physiologique, appelé syndrome de l’encoche sèche (TPD), est un des facteurs limitant la production de caoutchouc.Ce travail de thèse vise à identifier les gènes associés à la production et la neutralisation des ROS ainsi que leurs caractérisations dans les laticifères. Premièrement, nous avons fait une analyse bibliographique complète sur les gènes associés à la production et la neutralisation des ROS chez l’hévéa et les plantes modèles. La NADPH oxydase a été décrite comme la source principale de ROS chez les arbres stressés. Les enzymes antioxydantes et les antioxydants constituent le système de neutralisation des ROS. Deuxièmement, à partir d’une analyse à l’échelle du génome, 407 gènes impliqués dans la production des ROS et dans leur neutralisation ont été identifiés. Troisièmement, à partir d’une analyse du transcriptome, 164 gènes redox ont été détectés dans le latex du clone SP 217 et 161 dans celui du clone PB 260. Quatrièmement, à partir des petits ARNs et d’une analyse dégradome, 13 gènes ont été identifiés pour être clivés par 11 microARNs et 15 gènes clivés par 16 petits ARNs phasés dans le latex. Enfin, cette étude a mis en évidence des régulations spécifiques de la production des ROS et du système antioxydant dans le latex. HbRBOH2 a été identifié comme la source principale de ROS dans le latex. HbCuZnSOD4 pourrait être le contributeur majeur de la neutralisation des ROS dans le latex des arbres atteints de TPD
Hevea brasiliensis, a tropical tree, is the main commercial source of nature rubber. The rubber biosynthesis occurs in specialized latex cells of rubber tree. Up 90% dry weight of latex is nature rubber. The milky latex flows out from cut latex cells by tapping rubber tree trunk bark. Rubber exploitation by tapping every several days is very stressful for the bark of rubber tree. To stimulate latex production, ethylene releaser is applied during rubber exploitation in some cases. The stress is increased after hormone stimulation. Reactive oxygen species (ROS) is generated when plant suffers stresses from environment and harvesting activity. Over a certain limit of stress, ROS bursting is motivated in latex cell. A lots of the evidences showed that the ROS lead to the peroxidatic degradation of the unsaturated lipids of the membrane and then to destabilisation and lysis of the organelles. Lysis of the lutoids results in liberation of coagulating factors into latex and coagulation in situ of rubber particles in stressed trees. This serious physiology syndrome is tapping panel dryness (TPD) which is one of main factor limiting rubber production.This PhD aims at identifying ROS production and scavenging genes and their characterizations in latex cell. Firstly, we made a comprehensive bibliography study on ROS production and scavenging genes both in rubber tree and model plant. The NADPH oxidase was considered as the main source of ROS in the stressed trees. ROS scavenging enzymes and antioxidants constituted the ROS scavenging systems in latex. Secondly, based on a genome-wide analysis, 407 genes involved in ROS production and scavenging were identified. Thirdly, based on a transcriptome analysis, 164 redox-related genes were detected expressing in latex of clone SP217 and 161 genes expressing in latex of clone PB260. Fourthly, based on small RNA and degradome analysis, 13 genes were shown to be targeted by 11 microRNAs and 15 genes by 16 phased siRNA in latex. Lastly, this study illustrated specific regulation systems of ROS production and scavenging in latex. HbRBOH2 was identified as the main source gene of ROS in latex. HbCuZnSOD4 might be the most important ROS scavenging gene to detoxify the ROS in latex of TPD tolerant tree

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Honorato, Sara Braga. "Antioxidant effect of components of the latex from seringueira (Hevea brasiliensis)and mangabeira(Hancoria speciosa)on thermo-oxidative degradatiion of synthesic Poly (1,4-cis-isoprene". Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1429.

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FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
FundaÃÃo de Amparo Ã Pesquisa do Estado do CearÃ
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
This work is divided into two parts: The first is associated with the isolation of non-isoprenic components from the natural rubber (NR) latex from seringueira (Hevea brasiliensis) and mangabeira (Hancornia speciosa) by centrifugation. In the first centrifugation the phase serum was isolated (MAT 1). The rubber phase was treated with the surfactant sodium dodecyl sulphate (SDS) and isolated after the third centrifugation (MAT 2). The other materials tested in the synthetic rubber (PIS) were CENT 1, CENT 2 and the NR extract. These were kindly provided by Prof Jean Marinho from UNESP. The second part is associated with the possible antioxidant effect of the isolated latex components on the thermo-oxidative degradation of synthetic poly(1,4-cis-isoprene) carried out via infrared (FT-IR), thermogravimetric analysis (TG) and Nuclear Magnetic Resonance (RMN). It was observed that, from the substances obtained from the purification of the latex and tested on synthetic PIS, both MAT 1 and CENT 1 have pro-oxidant effects. The remain can be ordered in the following sequence in regards to their antioxidant capabilities: PIS + MAT 2 > PIS + NR EXTRACT > PIS + CENT 2 The calculation of the activation energy of the thermal degradation of PIS in synthetic air containing 2.0% of MAT 2 confirms that the stabilizer effect of PIS increases with the increase of this material, as all Ea of pure polymer are inferior to that of the doped sample. The NMR spectra for MAT 2 showed, in addition to the characteristic bands of cis-1,4-polyisoprene, also bands associated with fatty acids and/or SDS. The spectra of NR extract showed bands that are characteristic of oligosaccharides and minoritary cis-1,4-polyisoprene.
O presente trabalho Ã dividido em duas partes: A primeira estÃ relacionada com o isolamento dos componentes nÃo-isoprÃnicos do lÃtex da borracha natural (BN) da seringueira (Hevea brasiliensis) e mangabeira (Hancornia speciosa) por centrifugaÃÃo. Na primeira centrifugaÃÃo foi isolada a fase serum (MAT 1). A fase borracha foi tratada com o surfactante dodecil sulfato de sÃdio (SDS) e isolada apÃs a terceira centrifugaÃÃo, (MAT 2). Os outros materiais testados Ã borracha sintÃtica (PIS) foram o CENT 1, CENT 2 e o extrato de BN, os quais foram gentilmente cedidos pelo Prof. Jean Marinho da UNESP. A segunda parte refere-se ao possÃvel efeito antioxidante dos componentes do lÃtex isolados sobre a degradaÃÃo termo-oxidativa do poli (1,4-cis-isopreno) sintÃtico realizada atravÃs das tÃcnicas de Infravermelho (FT-IR), AnÃlise TermogravimÃtrica (TG) e RessonÃncia MagnÃtica Nuclear (RMN). Foi observado que, das substÃncias obtidas da purificaÃÃo do lÃtex e testadas no PIS sintÃtico, tanto o MAT 1 quanto o CENT 1 tÃm efeitos prÃ-oxidantes. Os demais podem ser ordenados na seguinte seqÃÃncia quanto ao poder antioxidante: PIS + MAT 2 > PIS + EXTRATO DE BN > PIS + CENT 2 O cÃlculo da energia de ativaÃÃo (Ea) da degradaÃÃo tÃrmica do PIS em ar sintÃtico contendo 2,0% do MAT 2 confirma que o acrÃscimo desse material exerce um efeito estabilizante ao PIS, pois todas as Ea do polÃmero puro sÃo inferiores Ã da amostra dopada. Os espectros de RessonÃncia MagnÃtica Nuclear para o MAT 2 exibiram, alÃm de sinais caracterÃsticos do cis-1,4-poliisopreno, sinais relativos a Ãcidos graxos e/ou SDS, enquanto que os espectros do Extrato de BN exibiram sinais caracterÃsticos de oligossacarÃdeos e poli (1,4-cis-isopreno) como componentes minoritÃrios.

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Thepchalerm, Chalao. "Influence of Hevea brasiliensis latex compartments on the storage hardening of natural rubber : study of the mesostructure by AF4-MALS and of the mineral element composition by ICP-MS". Thesis, Montpellier, SupAgro, 2014. http://www.theses.fr/2014NSAM0016/document.

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Le but de la présente étude était de vérifier l'influence de deux compartiments du latex d'Hevea brasiliensis, les lutoïdes et le sérum C, sur le durcissement au stockage et sur la mésostructure du caoutchouc naturel (NR). L'implication des composants minéraux du latex a fait l'objet d'un focus spécial. La mésostructure du NR a été étudié par fractionnement par couplage flux-force à flux asymétrique couplé à un détecteur à diffusion de lumière multiangulaire (AF4-MALS) et par chromatographie d'exclusion de tailles équipée d'un détecteur de diffusion de lumière multiangulaire (SEC- MALS). La spectrométrie de masse couplée à une torche à plasma (ICP- MS) a été utilisée pour déterminer la composition en éléments minéraux du NR.L'AF4 - MALS et l'ICP-MS n'ayant jamais été utilisées pour l'analyse du NR, les méthodes ont été développées. Pour l'AF4 - MALS, la meilleure séparation entre les deux populations principales, chaînes de polyisoprène isolées (pelote statistique) et les microagrégats (Gel<1μ), a été obtenue avec une diminution linéaire, plutôt qu'exponentielle, du flux croisé. Pour l'ICP-MS, les optimisations réalisées concernent la quantité de NR à échantillonner, la méthodologie de solubilisation des cendres, la concentration des solutions de cendres et la gestion des interférences m/z . Tous les éléments, excepté le soufre, ont été analysés en utilisant un mélange H2/He comme gaz de collision-réaction (mode CCT H2/He). La teneur en soufre a été déterminée par le rapport m/z égal à 48 (32S16O+) en mode CCT O2.Les différents compartiments du latex des champs (crème, skim, sérum C et lutoïdes) ont été séparés par centrifugation à grande vitesse. L'évolution de la mésostructure des films obtenus à partir de ces trois latex; latex des champ (FL), le latex de crème (CL) et de latex de skim (SK), par un procédé de structuration lente (échantillons stockés à température ambiante dans le laboratoire pendant 3 mois) a été suivie par SEC- MALS. Le skim n'étant pas sensible au processus de structuration lente, le nombre des étapes de centrifugation a été réduit. La stabilité des lutoïdes a été étudiée par un paramètre qualitatif (état visuel des lutoïdes après centrifugation) et un paramètre quantitatif (indice d'éclatement ou BI). Bien que les deux méthodes n'aient pas donné de résultats strictement corrélées, le BI peut être un bon indicateur de la stabilité des lutoïdes. Pour les échantillons de FL, une bonne corrélation entre la stabilité des lutoïdes et le durcissement au stockage (P) a été observée. Pour déterminer si des composés du C-sérum étaient également impliqués dans le durcissement au stockage, des expériences supplémentaires ont été effectuées en ajoutant des quantités variables de sérum C ou de lutoïdes à des particules de caoutchouc purifiées. L'augmentation à la fois de les quantités de sérum C et des lutoïdes a entrainé une augmentation du durcissement au stockage (P).La mésostructure des films et des feuilles séchées de l'air (ADS) préparés à partir des FL et CL a été analysée par SEC-MALS et AF4-MALS. Pour les échantillons d'ADS, quelle que soit la technique utilisée, les échantillons de FL présentaient des Mw, Mn et Gel>1μ supérieurs aux échantillons de CL. Cette différence entre échantillons de FL et de CL n'a pas été observée pour les échantillons de films
The aim of the present work was to study the influence of two Hevea brasiliensis latex compartments, namely lutoids and C-serum, on the storage hardening and on mesostructure of natural rubber (NR). A special focus was done on the involvement of mineral components of latex. The NR mesostructure was studied by asymmetrical flow field-flow fractionation coupled to a multiangular light scattering detector (AF4-MALS) and by size exclusion chromatography equipped with a multiangular light scattering detector (SEC-MALS). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the mineral element composition of NR.As AF4-MALS and ICP-MS were never used for NR analysis, the methodologies were developed. For AF4-MALS, the best separation between the two main populations, namely isolated polyisoprene chains (random coil) and microaggregates (Gel<1µ) was given by a linear decrease, rather than exponential, of the cross-flow. For ICP-MS, the optimizations were in terms of amount of NR to be sampled, ash solubilisation methodology, ash solutions concentrations and m/z interference management. All elements, except sulfur, were determined using a mixture H2/He as collision-reaction gas (CCT H2/He mode). Sulfur content was determined through the m/z equal to 48 (32S16O+) in the CCT O2 mode.The different compartments of the whole field latex (cream, skim, C-serum and lutoids) were separated by high speed centrifugation. The mesostructure evolution of films obtained from these 3 lattices; whole field latex (FL), cream latex (CL), and skim latex (SK), by a slow structuring process (samples stored at room temperature in the laboratory for 3 months) was followed by SEC-MALS. As it was observed that the skim was not sensitive to the slow structuring, the centrifugation steps were reduced.Lutoid stability was studied by a qualitative parameter (visual lutoid status after centrifugation) and a quantitative parameter (bursting index or BI). Although the two methods could not provide strictly correlated results, BI can be a good indicator of lutoid stability. For the FL samples, a good correlation between the lutoid stability and storage hardening (ΔP) was observed. To determine if some compounds of C-serum are also involved in the storage hardening, additional experiments were done adding variable quantities of C-serum or lutoids to purified rubber particles. The storage hardening (ΔP) increased by the increase of both C-serum and lutoid quantities.The mesostructure of films and air dried sheet (ADS) made from FL and CL lattices (obtained from reduced centrifugation process) were analyzed by SEC-MALS and AF4-MALS. Concerning the ADS samples, whatever the technique used, FL samples exhibited a higher Mw, Mn, and Gel>1µ than CL samples. This difference between FL and CL samples was not observed for film samples. The microaggregates (Gel<1µ) were presented in all samples but the FL samples had more compact microaggregates, with a much higher Mw than the CL samples. Moreover, AF4 showed that the structure of microaggregates was very different between ADS and film samples. The Mw of microaggregates of ADS was 2 to 4 times higher than that of films. The mineral elements were determined only on samples from ADS (FL and CL). The main elements in NR were K, P, Mg, and S, in decreasing order. The purification of rubber particles affected the decrease in the element contents. During the storage of the latex at room temperature, only calcium content decreased, for both FL and CL samples

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Araújo, Marcos Miranda de. "Efeitos da utilização de insulina e de um implante transitório de biomembrana de látex natural, derivado da seringueira Hevea brasiliensis, em um modelo experimental de perfuração traumática de membrana timpânica". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/17/17150/tde-20012013-151842/.

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Nos últimos anos, houve uma tendência na busca por substâncias reguladoras que pudessem otimizar o processo de cicatrização de membranas timpânicas (MTs) perfuradas. Objetivos: Determinar os efeitos da utilização da insulina tópica e da biomembrana de látex natural, de forma isolada e em associação, no processo de cicatrização de perfurações traumáticas de MTs. Materiais e Métodos: MTs de 61 ratos Wistar foram perfuradas nas porções anterior e posterior ao cabo do martelo. Os animais foram divididos em quatro grupos: Controle, Insulina, Látex e Insulina+Látex. No grupo Insulina, as perfurações foram tratadas com uso tópico de insulina regular. No grupo Látex, tratadas com biomembrana de látex natural. No grupo Insulina+Látex, tratadas com associação da insulina e da biomembrana de látex. As MTs foram avaliadas por técnicas histológicas com três, cinco e sete dias após sua perfuração traumática. Foram analisadas as morfometrias das espessuras das camadas epitelial, fibrosa e mucosa; tamanho da perfuração; área de secção transversal da MT; avaliação semiquantitativa e qualitativa da produção de colágeno por microscopia de polarização; e avaliação imuno-histoquímica das células epiteliais, dos miofibroblastos e da vascularização. Resultados: A insulina e a biomembrana de látex anteciparam o fechamento das perfurações traumáticas de MTs (p<0,01); estimularam precocemente o aumento da espessura da camada epitelial externa (p<0,01); promoveram aumento precoce da espessura da camada fibrosa (p<0,01); contribuíram para a maior identificação do anticorpo anti-panqueratina como marcador epitelial (p<0,05); aumentaram a marcação do anticorpo anti-alfa-actina de músculo liso (p<0,05), caracterizando maior proliferação de miofibroblastos. A insulina, isoladamente, provocou maior formação do colágeno tecidual (p<0,05), com fibras colágenas mais espessas e melhor organizadas (p<0,05). Conclusão: A insulina e a biomembrana de látex natural, de forma isolada e em associação, aceleraram o processo de cicatrização de perfurações traumáticas de MTs.
In recent years, there has been a tendency to search for regulatory substances that can optimize the healing process of perforated tympanic membranes (TMs). Objectives: To determine the effects of using topical insulin and natural latex biomembrane, alone or in combination, in the healing process of traumatic perforations of TMs. Methods: TMs of 61 Wistar rats were perforated in two sections, anterior and posterior to the malleus. The rats were divided into 4 groups: Control, Insulin, Latex, and Insulin+Latex. The Insulin group was treated with topical regular insulin. The Latex group was treated with natural latex biomembrane. The Insulin+Latex group was treated with a combination of insulin plus latex biomembrane. The TMs were histologically examined 3, 5, and 7 days post-perforation through morphometric analysis of the thickness of the epithelial, fibrous, and mucosal layers; size of the perforation; cross sectional area of the TM; semiquantitative and qualitative evaluation of the collagen production by polarization microscopy, and immunohistochemical evaluation of epithelial cells, myofibroblasts, and vascularization markers. Results: Insulin and latex biomembrane accelerated the healing process of the perforated TMs (p<0.01); stimulated early thickening of the outer epithelial layer (p<0.01); promoted premature increase in the thickness of the fibrous layer (p<0.01); contributed to a larger identification of anti-pankeratin antibody as epithelial marker (p<0.05); increased labeling of anti-alpha smooth muscle actin antibody (p<0.05), indicating greater proliferation of myofibroblasts. When insulin was used alone, it resulted in greater formation of collagen tissue (p<0.05), with thicker and better-organized collagen fibers (p<0.05). Conclusion: Insulin and natural latex biomembrane, used alone or in combination, accelerated the healing process of traumatic perforations of TMs.

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