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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Estudo dos compostos mesoiônicos tiadiazólicos contra Leishmania sp e inibição da tripanotiona redutase

Rodrigues, Raquel Ferreira January 2011 (has links)
Submitted by Tatiana Silva (tsilva@icict.fiocruz.br) on 2012-08-13T04:37:36Z No. of bitstreams: 1 raquel_f_rodrigues_ioc_bp_0056_2011.pdf: 571332 bytes, checksum: b292e41b82ba36c32976100adb623288 (MD5) / Made available in DSpace on 2012-08-13T04:37:36Z (GMT). No. of bitstreams: 1 raquel_f_rodrigues_ioc_bp_0056_2011.pdf: 571332 bytes, checksum: b292e41b82ba36c32976100adb623288 (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto de Comunicação e Informação Cientifica e Tecnológica em Saúde. Rio de Janeiro, RJ, Brasil. / A leishmaniose é uma das principais doenças parasitárias com prioridades de pesquisa segundo a Organização Mundial da Saúde. Aurgência por drogas mais seletivas e menos tóxicas tenm conduzido a pesquisa por novas terapias químicas. Os compostos mesoiônicos (Mls) da classe 1,3,2 - tiadiazol-2-aminida, apresentam um amplo espectro de atividades biológica, incluindo efeitos antitumoral e leishmanicida. Neste estudo investigamos a atividade in vitro de Ml-HH, Ml-4-NO2, Ml-3OCH3 e Ml-4-OCH3 sobre promastigotas e amastigotas axênicas de L. infantum e amastigotas intracelulares de L. infantum e L. amazonensis. Uma alta atividade leishmanicida foi demonstrada contra L. infantum e constatou-se uma relação de dose-resposta para formas amastigotas intracelulares de L. infantum e L. amazonensis pelo Ml-4-NO2. Em etapa seguinte investigamos in vivo o efeito de Mls nos seguintes modelos camundongo/parasito: CBA/J e L. amazonensis, BALB/c e L. amazonensis e BALB/c e L. infantum. No primeiro modelo, a administração por via subcutânea de Ml-HH e Ml-4-OCH3 levou a uma diminuição da carga parasitária no linfonodo adjacente à lesão e no baço. Nos dois modelos seguintes, altamente sensíveis à infecção, foram estudados Ml-HH, Ml-4-NO2, avaliando além de parâmetros daresposta terapêutica e tóxicos, possíveis efeitos imunomoduladores. Camundongos susceptíveis da linhagem BALB/c foram infectados por via subcutânea na pata com promastigotas de L. amazonensis e viaintraperitonal por L. infantum. Os tratamentos utilizados foram por vias tópica, intralesional para leishmaniose cutâna (LC) e intraperitoneal para leishmaniose visceral (LV). Glucantime, droga anti-Leishmania clássica, foi utilizada como referência. Embora a cura completa não tenha sido observada nos animais com LC, os grupos tratados com Ml-4 - NO2 e Ml-4-OCH3 apresentaram pequenas lesões na pata infectada até 12ª semana após a infecção sem apresentar ulcerações. Ogrupo LV tratado com Ml-4-NO2 apresentou carga parasitária negativa no baçço e no fígado. O tratamento de LV com Glucantime e Ml-4-OCH3 reduziu de forma significativa a carga parasitária. Porém o tratamento com Ml-HH, em todas as vias utilizadas, não apresentou atividade terapêutica para LC ou LV. A avaliação de enzimas hepáticas (AST e ALT) e de creatinina apontam para a ausência de toxidade no tratamento com Mls. Além disso, também foram realizados estudos na tentativa de buscar um alvo de ação destes compostos, investigando-se a tripanotiona redutase, enzima específica no parasito, responsável por desencadear uma cascata dedetoxificação nos parasitos. Estudos de cinética enzimática (enzimas recombinantes de L. infantum e T. cruzi) e modelagem molecular indicaram que Ml-4-NO2 é o único derivado mesoionico, dentre os estudados, capaz de inibir de forma não- competitiva esta enzima. Todos esses resultados demonstraram que Mls podem ser uma nova perspectiva no desenvolvimento de drogas com menor toxidade e capazes de modificar a resposta imunológica no combate a infecção por Leishmania, além de atuar sobre um alvo específico no parasito / Leishmaniasis is a parasitic disease with the main research priorities according to World Health Organization Aurgência drug more selective and less toxic tenm conducting research for new chemical therapies. The mesoionic compound (mls) of the class 1,3,2 - thiadiazol-2-aminida, have a broad spectrum of biological activities, including antitumor effects and antileishmanial. We investigated the in vitro activity of HH-Ml, Ml-4-NO2,-3OCH3 Ml and Ml-4-OCH3 on promastigotes and axenic amastigotes of L. infantum and intracellular amastigotes of L. infantum and L. amazonensis. A high leishmanicidal activity was demonstrated against L. infantum and it was observed a dose-response for intracellular amastigote L. infantum and L. amazonensis by ML-4-NO 2. In next step we investigate in vivo the effect of MLS in the following models mouse / parasite: CBA / J and L. amazonensis, BALB / c and L. amazonensis and BALB / c and L. infantum. In the first model, the subcutaneous administration of ML-HH and ML-4-OCH 3 led to a reduction of parasite load in lymph node adjacent to the lesion and the spleen. In both models the following, highly susceptible to infection have been studied HH-ML, ML-4-NO 2, besides evaluating parameters daresposta therapeutic and toxic potential immunomodulatory effects. Susceptible mice of BALB / c mice were infected subcutaneously in the foot with a promastigote L. by L. amazonensis and viaintraperitonal infantum.   The treatments were used by inland topical, intralesional cutâna for leishmaniasis (CL) and intraperitoneal for visceral leishmaniasis (VL). Glucantime, anti-Leishmania classical drug was used as reference. While the complete healing was not observed in animals with LC, the groups treated with ML-4 - NO2 and ML-4-OCH 3 showed small lesions in the infected foot up to 12 weeks after infection without presenting ulcerations. GROUP Ml treated with LV-4-NO2 showed negative bacco parasite load and liver. Treatment of VL with Glucantime and Ml-4-OCH3 significantly reduced parasite burden. However, treatment with ML-HH in all pathways used, had no therapeutic activity for LV or LC. The evaluation of liver enzymes (ALT and AST) and creatinine indicate the absence of toxicity in the treatment mls. In addition, studies were performed in an attempt to seek a target of action of these compounds by investigating whether the trypanothione reductase, an enzyme specific to the parasite responsible for triggering a cascade dedetoxificação in parasites. Kinetic studies enzyme (enzymes of L. infantum and recombinant T. cruzi) and molecular modeling indicated that ML-4-one derivative is NO2 mesoionico, of those studied, capable of inhibiting a non-competitive this enzyme. All these results showed that MLs may be a new perspective in the development of drugs with lower toxicity and can modify the immune response to fight infection by Leishmania, and act on a specific target in the parasite
12

Efeitos dos componentes acilhidrazonas pirazólicas sobre as formas evolutivas da Leishmania amazonensis e na infecção experimental em camundongos isogênicos CBA

Charret, Karen dos Santos January 2011 (has links)
Submitted by Tatiana Silva (tsilva@icict.fiocruz.br) on 2012-11-19T18:30:11Z No. of bitstreams: 1 karen_s_charret_ioc_bp_0055_2011.pdf: 28875915 bytes, checksum: 38bf86603dba71d83a48b9e25560c47f (MD5) / Made available in DSpace on 2012-11-19T18:30:11Z (GMT). No. of bitstreams: 1 karen_s_charret_ioc_bp_0055_2011.pdf: 28875915 bytes, checksum: 38bf86603dba71d83a48b9e25560c47f (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz.Instituto Oswaldo Cruz. Rio de janeiro, RJ, Brasil / Atualmente, não há vacina eficaz e o controle das leishmanioses depende principalmente da quimioterapia. Recentemente, novos compostos sintéticos os derivados carbohidrazidas pirazolocas apresentaram atividade em Leishmania amazonensis in vitro e quando testadas em modelo experimental murino de infecção de L. amazonensis mostraram eum efeito um efeito terapêutico significativo. Um estudo com compostos intermediários da síntesedas carbohidrazidas poderia ser interessante, pois estes possuem uma potencial atividade leishmanicida e ajudaria a cmpreender os mecanismos de ação dos compostos finais. Por outro lado, é necessário conhcer o comportamento do sistema imune frente a estes compostos na infecção por leishmaniose.Os compostos precursores naão foram ativos em formas promastigotas de L. amazonensis. No entanto, todos os compostos apresentaram atividade sobre formas de amastigotas e sem citotoxicidade em célula de mamíferos. Aqui, foi sugerida a contribuição farmacofórica do anel N-heteroaromático para a atividade leishmanicida e do grupamento hidrazina para o composto intermediário. Além disso, foi mostrado que todos os componentes podem induzir um aumento da produção de óxido nitrico em macrófagos estimulados ou não. Em camundongos CBA infectados com L amazonensis e tratados por via oral com os derivados carbohidrazidas, o estudo histopatológico rervelou que mudanças na derme foram correlacionadas com o tamanho macroscópico da lesão. Camundongos CBA infectados e tratados tinham lesões cutâneas menores, e as estruturas da epiderme e derme tinham níveis mais baixos de infiltrtado inflamatório, comparadas com as de camundongos controles infectados e não tratados. Também foi observado um infiltrado inflamatório misto contendo linfócitos e neutrófilos. Além disso, expressão de IL-4 RNAm foi menor no grupo tratado.. Um aumento dos níveis de anticorpos das subclasses específicas anti-Leishmania IgG2a e IgG3 foi observado nos grupos tratados com as pirozol carbohidrazidas exercem efeitos terapêuticos significativos, podendo agir diretamente sobre o parasito e/ou sobre as células dos sistemas imune do hospedeiro.. / Currently, there is no effective vaccine and control of leishmanioses depends mainly on the chemotherapy. Recently, new synthetic carbohidrazidas derivatives pirazolocas compounds showed activity on Leishmania amazonensis when tested in vitro and in experimental murine model of infection of l. amazonensis showed a significant therapeutic effect effect. A study of intermediate compounds síntesedas carbohidrazidas could be interesting, as these have a potential activity leishmanicida and help cmpreender the mechanisms of action of compounds. On the other hand, it is necessary to know the behavior of the immune system against these compounds in leishmaniasis infection.The precursor compounds are active in ways does promastigotas of l. amazonensis. However, all compounds showed activity on amastigote forms and without cytotoxicity in mammalian cell. Here, it was suggested the contribution farmacofórica of the ring N-heteroaromatic compound for leishmanicida and activity of hydrazine to the intermediate grouping. In addition, it was shown that all components can induce an increase in nitric oxide production in macrophages stimulated or not. In CBA mice infected with l. amazonensis and treated orally with carbohidrazidas derivatives, the histopathologic study rervelou that changes in the DermIS were correlated with the macroscopic size of the lesion. CBA mice infected and treated tin
13

Recrutamento de neutrófilos induzido por leptina em modelo murino de obesidade induzida por dieta

Almeida, Gláucia Souza de January 2012 (has links)
Submitted by Gilvan Almeida (gilvan.almeida@icict.fiocruz.br) on 2016-10-11T17:33:25Z No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 72053.pdf: 1362653 bytes, checksum: fba356e2b9087f52b86707b982c63e23 (MD5) / Approved for entry into archive by Anderson Silva (avargas@icict.fiocruz.br) on 2016-10-25T16:57:44Z (GMT) No. of bitstreams: 2 72053.pdf: 1362653 bytes, checksum: fba356e2b9087f52b86707b982c63e23 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) / Made available in DSpace on 2016-10-25T16:57:44Z (GMT). No. of bitstreams: 2 72053.pdf: 1362653 bytes, checksum: fba356e2b9087f52b86707b982c63e23 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2012 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / Leptina é um hormônio/citocina produzido pelo tecido adiposo que inibe a ingestão alimentar e o metabolismo lipídico. É altamente expressa na obesidade, sem no entanto intensificar seu efeito de inibição do apetite. Dentre outras funções, regula a imunidade inata e adaptativa. Sabe-se que a leptina ativa macrófagos, induzindo a produção de mediadores inflamatórios, como TNF-\F061, IL-1, IL-6 e LTB4. A leptina parece ainda regular a participação de neutrófilos em respostas inflamatórias. No entanto, não estão esclarecidos os mecanismos pelos quais a leptina seria capaz de regular migração ou ativação de neutrófilos, uma vez que estes não apresentam o principal receptor funcional de leptina, ObRb. Estudos in vitro não são conclusivos quanto aos efeitos serem diretos ou indiretos, enquanto estudos in vivo não se detém a estudar efeitos quimiotáticos de leptina sobre neutrófilos. O objetivo deste trabalho é investigar a sinalização por leptina envolvida na migração de neutrófilos. Para isso, foi realizada estimulação de animais C57Bl/6, bem como knockout de TNFR1-/-, MIP-1\F061-/-, 5-LO -/-, PI3K\F067-/-, machos, com leptina i.p. por 1, 6 e 24 h para avaliação do influxo de neutrófilos para a cavidade peritoneal e quantificação de mediadores inflamatórios no sobrenadante de lavado peritoneal e plasma. Também foram realizados tratamentos com rapamicina, para inibição de mTOR, Zileuton e U-75302, para inibir a sinalização por LTB4, bem como anticorpos anti-KC Foi observado que macrófagos incubados com leptina 20 nM in vitro produzem KC e TNF-\F061, mediadores que recrutam neutrófilos. In vivo, foi observado que a migração de neutrófilos por leptina é dependente de TNF-\F061, KC e PI3K\F067, e independente de 5-LO/LTB4, MIP-1\F061\F020e mTOR. Para avaliar o efeito de hiperleptinemia crônica na imunidade inata, foi estabelecido um modelo murino de obesidade induzida por dieta. Animais do grupo obeso foram alimentados com dieta hiperlipídica com 60% de teor calórico proveniente de gordura, enquanto a dieta controle possui 10% de teor calórico proveniente de gordura. Animais obesos apresentaram hiperglicemia e hiperleptinemia. A dieta hiperlipídica predispôs a ativação de macrófagos peritoneais por leptina, incrementando a produção de corpúsculos lipídicos. Os níveis de TNF-\F061 no sobrenadante de lavado peritoneal foram maiores em animais obesos não estimulados com leptina i.p., sendo a estimulação com leptina i.p. capaz de induzir recrutamento de neutrófilos em animais obesos. Tais eventos sugerem que a dieta hiperlipídica induziu background inflamatório, que, no entanto, não interferiu na capacidade da leptina induzir recrutamento neutrofílico. Tais dados sugerem que leptina promove recrutamento de neutrófilos por meio da ativação de macrófagos e produção de mediadores. Além disso, a obesidade experimental promove ativação subclínica de macrófagos, sem alterar o recrutamento de neutrófilos. Com este trabalho, espera-se contribuir para o melhor entendimento da participação da leptina na regulação do sistema imune inato / Leptin is an adipose tissue-produced hormone/cytokine which inhibits food intake and lipid metabolism. It is highly expressed in obesity without appetite inhibition enhancement. Also regulates innate and adaptive immunity. It is known that leptin activates macrophages inducing the production of inflammatory mediators such as TNF-\F061, IL-1, IL-6 and LTB4. Leptin regulates neutrophil functions in inflammatory responses. However, mechanisms by which leptin could induce neutrophils migration and activation are not elucidated, since they do not show the main functional leptin receptor, ObRb. In vitro studies are inconclusive about direct or indirect effects, while in vivo studies usually do not focus on leptin effects on neutrophil chemotaxis. This study aims to investigate leptin signaling involved in neutrophil migration. C57BL/6 and knockout TNFR1-/-, MIP-1\F061-/-, 5-LO-/-, PI3K\F067-/- male mice were stimulated with leptin ip for 1, 6 or 24 h for evaluation of neutrophil influx into peritoneal cavity and quantification of inflammatory mediators in the supernatant of peritoneal fluid and plasma. It was also performed treatments with rapamycin, for inhibition of mTOR, Zileuton and U-75302 for inhibition of LTB4 signaling, and anti-KC antibodies. Macrophages incubated with 20 nM leptin in vitro produce KC and TNF-\F061, neutrophil recruitment mediators. In vivo, neutrophil migration induced by leptin is dependent on TNF-\F061, KC and PI3K\F067, and independent on 5-LO/LTB4, MIP-1\F061 and mTOR To evaluate the effect of chronic hyperleptinemia in innate immunity, we established a murine model of diet induced obesity. The obese animals were fed with high fat diet with 60% calories from fat content, while the control diet had 10% of caloric content derived from fat. Obese animals showed hyperglycemia and hyperleptinemia. The fat diet predisposed the activation of peritoneal macrophages by leptin, increasing the lipid bodies formation. The levels of TNF-\F061 in the supernatant of peritoneal fluid were higher in obese animals, not stimulated with leptin ip; leptin ip stimulus induced neutrophil recruitment in obese animals. Such events suggest that the high fat diet induced inflammatory background, which, however, did not affect the ability of leptin to induce neutrophil recruitment. These data suggest that leptin promotes neutrophils recruitment through the activation of macrophages and production of mediators. Furthermore, experimental obesity promotes subclinical activation of macrophages, without changing the recruitment of neutrophils. This thesis is expected to contribute to a better understanding of leptin role in the regulation of innate immune system
14

Population biology and aspects of the socio-spatial organisation of the woodland dormouse Graphiurus Murinus (Desmaret, 1822) in the Great Fish River Reserve, South Africa

Madikiza, Zimkitha Josephine Kimberly January 2010 (has links)
The population biology and socio-spatial organisation of the woodland dormouse, Graphiurus murinus (Desmarest, 1822), was investigated in a riverine forest at the Great Fish River Reserve (GFRR), South Africa. Data were collected by means of a monthly live trapping and nestbox monitoring programme. Between February 2006 and June 2007, 75 woodland dormice were trapped and/or found in nestboxes and marked: these were 39 adults (13 males, 21 females, five undetermined) and 36 juveniles (five males, 14 females, 17 undetermined). The population showed a steady increase from June 2006–November 2006 and a peak in December 2006–January 2007 as a result of the influx of juveniles. The minimum number of dormice known to be alive (MNA) varied between 40 in December 2006– January 2007 (summer), and a low of three in June 2007 (winter). The range in population density was therefore between 1.2 and 16 dormice per ha. Winter mortality and/or spring dispersal accounted for the disappearance of 55 percent of juveniles. The overall annual adult:juvenile ratio was 1.08. The overall sex ratio was 1.94 female per one male. In females, reproductive activity was observed from September 2006 to end January 2007. The pattern observed in males was similar, as dormice with descended testes were exclusively found from October to end January. Females gave birth during the second half of October to beginning of February. Litters (n = 11) consisted of an average (± SD) 3.73 ± 0.47 young. Over the study period, 27 dormice were trapped or found in nestboxes more than eight times, thus allowing me to estimate their home range size and the spatial overlap between these individuals. On average, dormouse home range size was 2,514 m2 (range: 319 – 4,863 m2). No difference was recorded between one-year old adults and older adults, or between all adults and juveniles. However, adult male dormice (3,989 m2, n = 5) had home ranges almost twice as large as females (2,091 m2, n = 9). No similar trend was found in juveniles. Intrasexual home range overlap was on average 62 percent in adult males, and 26 percent in adult females. However, females overlapped with more neighbouring female home ranges than did males with neighbouring male home ranges, so that, as for males, only small parts of female home ranges were really exclusive. On average, males overlapped a larger Abstract Ecology of woodland dormice M.Sc. Thesis 16 proportion (48 percent) of female home ranges than did females with neighbouring male home ranges (27 percent). In addition, males overlapped with significantly more female home ranges (7.8) than did females with male home ranges (4.9). Trapping success and nestbox data agree with the socio-ecological model. Females showed increased mobility during summer, more likely to find suitable nesting sites, and food for milk production during the reproductive season. The use of nestboxes, however, was constant throughout the year. In males, both the trapping success and nestbox use were higher during the mating season (spring), when an increased mobility and occupation of nestboxes probably increased the chances to locate and mate with (a) receptive female(s). Hence, food and (artificial) nest sites may constitute an important resource for females, whereas females seem to represent the main resource for males. Although food availability was not determined, a comparison of female and male distribution patterns provided interesting information on the mating system of woodland dormice. In GFRR, the dispersion pattern of female woodland dormice was “rather” clumped, i.e. females were non-territorial. As some females showed a dyadic intrasexual overlap of up to 90 percent, and population density was very high at the study site, this may indicate that food was very abundant and/or renewed rapidly. Based on the wide range of birth dates observed during the study period, females clearly come into oestrus at different times. In such circumstances (asynchronous sexual receptivity in females), the Female in Space and Time Hypothesis (Ims 1987a) predicts that males will be non-territorial and promiscuous. Live-trapping, nestbox use and home range data indeed suggested that male woodland dormice do not defend territories, but search for and aggregate around receptive females during the mating season.
15

Molecular evolution of the carboxy terminal, the putative sperm-ZP binding site, of the zona pellucida 3 glycoprotein in old world murine rodents.

Swann, Christine A. January 2007 (has links)
In mammals, before fertilisation can occur, sperm have to bind to, and penetrate, the extracellular coat of the oocyte, the zona pellucida (ZP). In the laboratory mouse, which has been used as a model system for fertilization studies, sperm-ZP binding has been found to be mediated by a region near the carboxy terminal, encoded by exon 7 of the Zp3 gene. This region shows considerable interspecific sequence diversity in North American cricetid rodents, with some evidence of adaptive evolution, suggesting that this may contribute to species specific sperm-ZP binding. However, by contrast, in a preliminary study of three species of Australian murine rodents an identical protein sequence of the region encoded by exon 7 of Zp3 was found to be present. The aim of this present study was to determine the pattern of sequence diversity of this region in the most speciose subfamily of mammals, the murine rodents, and to obtain insight into the selective pressures involved in its evolution. For this, DNA was extracted from murine rodents of Africa, Eurasia, South-east Asia, New Guinea and Australia. The nucleotide and predicted amino acid sequence of exons 6 and 7 of Zp3 in 96 murine species from 14 divisions, as recently defined by Musser and Carleton (2005), was determined and compared. Generally, it was found that closely related species shared a highly similar ZP3 sequence. Maximum likelihood analyses of codon substitution models using representatives from 14 murine divisions, suggested that positive selection had occurred within only a few lineages at several different codon sites adjacent to, or within, the putative combining-site for sperm of ZP3. Positive selection was not evident when the analysis was restricted to the Australian taxa which showed low levels of both intra- and inter-generic sequence divergence. There was no good evidence that this region contributes to species specificity of sperm-ZP binding in these species. These findings thus suggest that the selective forces acting on the Zp3 exon 7 region during the evolution of the murine rodents have varied possibly due to a range of selective pressures not necessarily restricted to the prevention of hybridization. It seems unlikely, therefore, that the amino acid sequence of the exon 7 coding region contributes to species specificity of sperm-ZP binding within most of the lineages from this most speciose subfamily of eutherian mammals. / http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1294654 / Thesis(Ph.D.)-- School of Medical Sciences, 2007
16

3D cranial morphometry, sensory ecology and climate change in African rodents / Morphométrie crânienne 3D, écologie sensorielle et changement climatique chez les Rongeurs Africains

Nengovhela, Aluwani 18 December 2018 (has links)
L'ordre des rongeurs (Rodentia) est le groupe de mammifères le plus riche en espèces, les muroïdes étant la superfamille la plus diversifiée. Comme ils occupent des niches écologiques arboricoles, semi-aquatiques, souterraines et terrestres, les rongeurs peuvent présenter des traits morphologiques reflétant leurs adaptations à des environnements aussi divers. Cette thèse porte sur la morphologie de l'endocrâne, de la bulle auditive et de la cochlée dans trois tribus (Otomyini, Taterillini et Gerbillini) représentant 10 espèces de rongeurs africains, en se concentrant sur la variabilité de ces traits, leur fonction et leur adaptabilité, à l'aide d'imagerie par micro-scanner et de méthodes de comparaison de formes tridimensionnelles. De plus, les variations de la taille du crâne ont également été étudiées en fonction du réchauffement climatique et des variables climatiques. Les changements / variations morphologiques sont liées à des différences environnementales. Par conséquent, chaque chapitre de cette étude détaille l'effet des changements environnementaux (dans l'espace et dans le temps) sur différents traits morphologiques, c'est-à-dire la taille générale du crâne (chapitre 2), la cochlée et les bulles auditives (chapitre 3), et la taille et la forme endocrânienne (chapitre 4). Le chapitre 2 traite spécifiquement du changement climatique au sens strict et les deux autres chapitres traitent de différents gradients environnementaux. Le chapitre 2 teste l'applicabilité de la "troisième réponse universelle au réchauffement" (c'est-à-dire de la diminution de la taille corporelle) et de la "règle des ressource" dans deux sous-familles de muridés, Murinae et Gerbillinae. L'étude montre que la troisième réponse n'est pas universelle puisqu'une seule espèce s'est conformée à ce type de réponse. De plus, il a été démontré que la disponibilité de nourriture (règle des ressources) était un facteur plus important que la règle de Bergmann pour expliquer les corrélations entre variations de l'environnement et celles de la taille des espèces de rongeurs.[...] / The order Rodentia is the most speciose group of mammals with muroids being the most diverse superfamily. Since they are represented in arboreal, semiaquatic, subterranean and terrestrial niches, rodents may exhibit morphological traits reflecting their adaptations to such diverse environments. This thesis focuses on the morphology of the endocranium, auditory bulla and cochlea in three tribes (Otomyini, Taterillini and Gerbillini) representing 10 species of African rodents, concentrating on their variability, function and adaptability, using micro-CT imaging and 3D shape comparative methods. Additionally, variations in cranial size were also studied in respective of global warming and climatic variables. Morphological changes/variations are a result of environmental change, therefore each chapter in this study details the effect of environmental change (in space and time) on different morphological traits i.e. general cranial size (chapter 2), cochlea and auditory bulla (chapter 3) and endocranial size and shape (chapter 4). With chapter 2 dealing specifically with climate change in its straict sense and the remaining two chapters looking at different environmental gradients. Chapter 2 tests the applicability of the "third universal response to warming" (i.e. declining body size) and the Resource Rule in two murid subfamilies, Murinae and Gerbillinae. The study shows that the third response is not as universal as only one species conformed to this response. Further, food availability (Resource Rule) was shown to be the more important factor correlated with body size variations in rodent species than Bergmann's Rule. [...]
17

Avaliação da resposta terapêutica de um isolado murino de Schistosoma mansoni ao praziquantel: uma abordagem morfológica e biológica.

Silva, Michele Costa da January 2011 (has links)
Submitted by Alessandra Portugal (alessandradf@ioc.fiocruz.br) on 2013-09-17T15:45:54Z No. of bitstreams: 1 Tese Biologia Parasitaria Michele Costa da Silva.pdf: 12475456 bytes, checksum: 609ce8de504a83a73a1066ce6c810c6c (MD5) / Made available in DSpace on 2013-09-17T15:45:54Z (GMT). No. of bitstreams: 1 Tese Biologia Parasitaria Michele Costa da Silva.pdf: 12475456 bytes, checksum: 609ce8de504a83a73a1066ce6c810c6c (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / O munícipio de Sumidouro é localizado na região serrana do estado do Rio de Janeiro, onde a infecção por Schistosoma mansoni tem sido descrita em humanos e em roedores silvestres. A população humana vem sendo submetida a sucessivos programas de controle desde a década de 1950. Vários estudos indicam que o rato d’água (Nectomys squamipes) é um reservatório natural de S. mansoni, a sua presença em localidades endêmicas, pode prejudicar os programas de controle da esquistossomose. Em condições de laboratório, vermes adultos de S. mansoni apresentam plasticidade fenotípica induzida por modificações no microambiente do parasita, principalmente durante a primeira passagem em condições de laboratório. Em nosso estudo, avaliamos o efeito do praziquantel (PZQ) no isolado R, isolado de N. squamipes naturalmente infectados, provenientes de Sumidouro, utilizando parâmetros parasitológicos e morfológicos. Os parâmetros parasitológicos (ovos eliminados nas fezes, a redução de vermes adultos e o oograma) foram utilizados para avaliar os efeitos do PZQ no isolado R de S. mansoni. Utilizamos também, um isolado de laboratório (isolado BH) como controle. Camundongos infectados com 50 cercárias foram tratados por via oral com PZQ nas seguintes dosagens: 62,5mg/kg (grupo 1), 125mg/kg (grupo 2), 250mg/kg (grupo 3) e 500mg/kg (grupo 4). Cada dose foi dividida em 3 dias (49, 50 e 51 dias pós-infecção). Os dados foram analisados usando o teste estatístico ANOVA. Nos experimentos com o isolado R, não foram observados ovos nas fezes com as doses 250mg/kg e 500mg/kg (p<0,05), enquanto a excreção em BH chegou à zero com todas as doses. A redução da carga parasitária foi significativamente maior (p<0,05) nas duas concentrações maiores testadas de PZQ, independente do isolado. Com 62,5mg/kg, a porcentagem de ovos imaturos variou de 17% (isolado R) à 38% (isolado BH). Na dosagem de 125mg/kg, a porcentagem de ovos imaturos variou de 20% (isolado R) à 16% (isolado BH). Com 250mg/kg, a contagem de ovos imaturos caiu significativamente à 1% (isolado R) e à 4% (isolado BH). Com 500mg/kg, não foram encontrados ovos imaturos no isolado R, enquanto que em BH o valor era de 8%. Nenhuma dosagem afetou, significativamente (p>0,05), a porcentagem de ovos maduros, independente do isolado. Todos os grupos tratados apresentaram um grande aumento na quantidade de ovos mortos, com diferenças significativas (p<0,001) de 62% e 64% nos grupos 3 e 4, respectivamente (isolado R). A porcentagem de ovos mortos subiu de 34% (grupo 1) para 58% (grupo 3) no isolado BH. Embora o grupo 4 tenha mostrado um pequeno aumento na porcentagem de ovos mortos (46%), foi significativamente maior (p<0,001) comparado com os 8% do controle. Os helmintos machos do isolado R (grupos 3 e 4) apresentaram diminuição dos tubérculos. Dos espécimes fêmeas analisados do isolado R, 44% (grupo 3) não apresentaram ovo. O isolado BH, também apresentou diminuição de tubérculos nos helmintos machos (grupos 3 e 4). Os lobos testiculares dos vermes dos grupos tratados apresentaram área e comprimento menor em relação aos helmintos recuperados de camundongos não tratados. Os nossos dados demonstram que o isolado silvestre testado é susceptível ao PZQ. / Sumidouro municipality is a mountain region of the Rio de Janeiro state, where natural schistosomiasis mansoni has been described in both human and water rat population. The human population has been submitted to successive control programs since around 1955. A number of studies suggest that water rat (Nectomys squamipes) is one natural reservoir of Schistosoma mansoni, which may implicate as a confounding factor for control programs of schistosomiasis. Under laboratory conditions, S. mansoni adult worms present phenotypic plasticity induced by modifications in the parasite's microenvironment, mainly during the first passage under laboratory conditions. In our study the effects of praziquantel (PZQ) were evaluated on the isolate (R) first isolated from naturally-infected N. squamipes from Sumidouro by parasitological and morphological parameters. The therapeutic effects of PZQ against a S. mansoni isolate derived from N. squamipes (isolate R) and a susceptible isolate (BH) were analyzed in Swiss mice by fecal egg counting, adult worm load and oogram pattern. Infected mice were orally administrated with 62.5mg/kg; 125mg/kg 250mg/kg and 500mg/kg, each dose divided over 3 days (49, 50 and 51 days after infection). The data were analyzed using one-way analysis of variance (ANOVA). In regard to isolate R, no fecal eggs were observed with 250mg/kg and 500mg/kg (p < 0.05), whereas BH excretion reached zero with all doses. Mean worm burden reduction was significantly (p < 0.05) higher at the two highest concentrations tested of PZQ, regardless of isolate. At 62.5mg/kg, the percentage of immature eggs varied from 17% (isolate R) to 38% (BH isolate). At 125mg/kg, the percentage of immature eggs varied from 20% (isolate R) to 16% (isolate BH). At 250mg/kg, immature eggs dropped significantly to 1% (isolate R) and 4% (isolate BH). At 500mg/kg, no immature eggs were found in isolate R, whereas in BH was 8%. No dosage significantly (p > 0.05) affected the percentage of mature eggs, regardless of isolate. There was a large increase in the percentages of dead eggs in all treated groups with significant (p < 0.001) increases of 62% and 64% in groups 3 and 4, respectively (isolate R). The percentage of dead eggs rose from 34% (group 1) to 58% (group 3) in isolate BH. Although group 4 showed lowest increase in the percentage of dead eggs (46%), it was significantly higher (p < 0.001) compared to the 8% in the control. Male worms from isolate R (groups 3 and 4) showed decrease of the tubercles. In female worms from isolate R, 44% (group 3) showed no egg. The isolate BH also showed decrease of the tubercles in male worms (groups 3 and 4). In general, morphometric values of reproductive system (testicular lobes) specimens grown in treated mice were lower than those of control mice. Our findings indicate that the wild isolate from N. squamipes is susceptible to PZQ.
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Camundongos inoculados com DENV2 por via intracerebralhistopatologia, detecção viral e avaliação de proteção mediada por uma vacina de DNA

Silva, Juliana Fernandes Amorim da January 2015 (has links)
Made available in DSpace on 2016-04-04T12:35:23Z (GMT). No. of bitstreams: 2 juliana_silva_ioc_mest_2015.pdf: 9301991 bytes, checksum: 154a53db0411f9dac834feb27f65b697 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2016-02-23 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / A dengue constitui um sério problema de saúde pública, principalmente em regiões tropicais e subtropicais do mundo. Uma grande dificuldade para se estudar essa doença é a falta de um modelo animal que reproduza os efeitos da infecção observados em humanos. Apesar disso, um dos modelos mais utilizados para testes de vacinas contra a dengue se baseia na inoculação em camundongos por via intracerebral (i.c.) de vírus neuroadaptado. No entanto, poucos estudos avaliaram o efeito da infecção i.c. e/ou proteção gerada por protótipos vacinais em diferentes órgãos, tais como fígado, um dos órgãos comprometidos pela dengue em humanos. O nosso grupo construiu a vacina de DNA, pcTPANS1, que induziu altos níveis de sobrevivência em camundongos desafiados por via i.c. com vírus da dengue 2 (DENV2). Diante disso, o presente trabalho se propõe avaliar aspectos da patogênese no cérebro, cerebelo, fígado e pulmão, no modelo de camundongos BALB/c inoculados pela via i.c. com uma dose letal de DENV2, em diferentes dias após infecção (d.p.i.). Adicionalmente, tais análises foram estendidas para animais imunizados com a vacina pcTPANS1 e desafiados com DENV2. Detectamos alterações histopatológicas no cérebro/cerebelo (edema, hemorragia, gliose reacional, microglia hiperplásica e hipertrofiada e infiltrado mononuclear na pia-máter, no neurópilo e perivasculares), no fígado (edema, hemorragia, balonização hepatocitária, infiltrado mononuclear, hiperplasia e hipertrofia de células de Kupffer) e no pulmão (edema, hemorragia, infiltrados mononucleares peribronquiolares, aumento do número de macrófagos alveolares e espessamento de septo interalveolar) Alguns destes danos foram quantificados, utilizando uma escala subjetiva com atribuição de diferentes graus, revelando diferenças significativas. Os animais inoculados com DENV2 também apresentaram um aumento dos níveis séricos das enzimas hepáticas ALT e AST, principalmente de AST ao final da infecção, com diferenças significativas em relação aos controles. Por outro lado, em todos os tecidos dos camundongos vacinados com pcTPANS1 observamos uma melhora progressiva dos danos, quando comparados com os animais somente infectados. Também detectamos a presença do DENV2 no cérebro/cerebelo, no sangue e no pulmão dos animais em ensaios in vitro de infecção de células Vero e/ou por RT-PCR em tempo real. Nos animais somente infectados, observamos no cérebro/cerebelo altos títulos de partículas virais infecciosas e cópias de RNA viral. Já no soro, o maior percentual de animais com a presença de DENV2 foi entre o 90 e 110 d.p.i.. Por outro lado, não foi possível a detecção do vírus no fígado, e no pulmão a detecção foi muito baixa. Entretanto, verificamos a presença do antígeno NS3 de DENV2 não só no tecido nervoso, mas também no hepático, através de ensaios de imunohistoquímica. Em contrapartida, os animais vacinados com pcTPANS1 e desafiados com o vírus apresentaram uma redução drástica na viremia com DENV2. De um modo geral, os nossos estudos podem contribuir para uma melhor compreensão da patogênese da dengue, assim como servir de parâmetro para a avaliação da proteção induzida pela vacina pcTPANS1, bem como de outras vacinas / The dengue is a serious public health problem, mainly in tropical and subtropical regions of the world. One of the great difficulty to study this disease is the lack of an animal model that mimics the infection effects observed in humans. Nevertheless, one of the most widely used model for vaccine tests against dengue is based on the inoculation of mice by the intracerebral route (i.c.) with neuroadapted virus. However, few studies have evaluated the effects of i.c. infection and/or protection generated by vaccine prototypes in different organs, such as the liver, one of the compromised organ in dengue in humans. Our group have constructed a DNA vaccine, pcTPANS1, which induced high survival rates in mice challenged by the i.c. inoculation with dengue virus 2 (DENV2). Therefore, the present work aim to evaluate aspects of the pathogenesis in the brain, cerebellum, liver and lung in the BALB/c mouse model intracerebrally inoculated with a lethal dose of DENV2, at different days post infection (d.p.i.). In addition, these analyzes were extended to pcTPANS1-immunized animals challenged with DENV2. We detect histopathological changes in the brain/cerebellum (hemorrhage, edema, reactive gliosis, hyperplasic and hypertrophied microglia and mononuclear infiltrate in the pia-mater, neuropile and perivascular), the liver (hemorrhage, edema, hepatocyte ballooning, mononuclear infiltrate, hyperplasia and hypertrophy of Kupffer cells) and the lung (hemorrhage, edema, peribronchial mononuclear infiltrates, increased number of alveolar macrophages and thickening of interalveolar septa). Some of these damages were quantified using a subjective scale with different degrees and revealing significant differences. Animals inoculated with DENV2 also showed increased serum levels of the liver enzymes AST and ALT, mainly AST on the end of infection, with significant differences compared to controls. On the other hand, in all the tissues of pcTPANS1-vaccinated mice, we observed a progressive improvement of damages when compared with only infected animals. We also detected the presence of DENV2 in the brain/cerebellum, blood and lung of animals by in vitro assays of infected Vero cells and/or by real time RT-PCR. In only infected animals, we observed high titers of infectious viral particles and viral RNA copies in brain/cerebellum. In serum, the highest percentage of animals with infeccious DENV2 particles was found between 90 and 110 d.p.i.. However, it was not possible to detect the virus in the liver, and the detection in lung was very low. Despite of this, we verified the presence of DENV2 antigen, NS3, not only in nervous tissue but also in liver, by immunohistochemistry assays. In contrast, pcTPANS1-vaccinated animals challenged with the virus showed a drastic reduction of viremia with DENV2. In general, our studies may contribute to a better understanding of dengue pathogenesis, and also serve as a parameter for evaluation of the vaccine-induced protection with pcTPANS1, as well as with other vaccines.
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A study of biochemical and morphological aspects of macrophage function in experimental murine Nocardia asteroides and Nocardia brasiliensis infections

Stephens, Janet January 1987 (has links)
It is submitted in this thesis that the degree of activation or inhibition of macrophage function may differ in N. asteroides and N. brasiliensis infections with respect to release of plasminogen activator and of lysozyme The pattern of secretion of plasminogen activator and lysozyme in N. asteroides infections appears to differ in N. brasiliensis infection; and there is possibly a difference in the amount of lysozyme released by 2 day N. asteroides-activated macrophages and 2 day N. brasiliensis -activated macrophages. Strains of Nocardia organism did not influence macrophage morphology or ultrastructure. The study also shows the biochemical characteristics of plasminogen activator and lysozyme release, but not macrophage morphology and ultrastructure, are modified in the first 21 days of experimental Nocardia infections. There are three apparent mechanisms by which virulent strains of N. asteroides manage to survive within macrophages: (i) an ability to inhibit phagosome-lysozome fusion: (ii) alteration in the intraphagosomal pH: and (iii) alteration in the activity of the lysozomal enzyme acid-phosphatase. This study attempted to elucidate further the mechanisms enabling Nocardia organisms to persist and grow within macrophages. Reduced lysozyme release reflects diminished functional status of the macrophages of mice inoculated with N. asteroides or N. brasiliensis at certain times during infection. Reduced intracellular lysozyme levels have been linked with defects in bactericidal function. Such a reduction in intracellular and consequently extracellular levels of lysozyme might explain the capacity of Nocardia to survive intracellularly and to proliferate in the macrophage host.
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Avaliação da eficácia do (-) !-bisabolol contra Leishmania amazonensis através de tratamento tópico em modelo murino

Rottini, Mariana Margatto January 2015 (has links)
Made available in DSpace on 2016-05-11T13:06:35Z (GMT). No. of bitstreams: 2 mariana_rottini_ioc_dout_2015.pdf: 66121272 bytes, checksum: 81ebf83865bc58345b44635091ee970f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / As opções de tratamento para leishmaniose tegumentar, atualmente disponíveis, apresentam problemas envolvendo a eficácia, os efeitos colaterais e os casos de resistência do parasito relacionados aos principais fármacos utilizados. Além disso, todos os fármacos são de administração parenteral, o que depende de profissionais experientes e deslocamento do paciente ao local de tratamento. Por esse motivo, muitos abandonam o tratamento, o que leva ao surgimento de cepas de Leishmania resistentes. Isso tem incentivado a pesquisa de novos agentes, com características leishmanicidas que apresentem menores efeitos colaterais e que sejam de administração mais fácil. Assim, a utilização de produtos naturais, derivados de plantas, vem despertando o interesse de pesquisadores na busca de tratamentos alternativos para a leishmaniose cutânea. Alguns óleos essenciais têm mostrado, em ensaios experimentais, uma efetiva ação leishmanicida, o que faz desses compostos promissoras opções no tratamento desta doença. Resultados obtidos, anteriormente, pelo nosso grupo, demonstraram que o (-)\03B1-bisabolol apresenta potente atividade leishmanicida, in vitro, contra formas promastigotas e amastigotas intracelulares de L. amazonensis. Ao avaliarmos a citotoxicidade deste óleo demonstramos que este composto apresentou maior atividade citotóxica para os parasitos que para os macrófagos Além disso, foi possível demonstrar alterações morfológicas e ultraestruturais nos parasito, tanto em formas promastigotas, como em formas amastigotas interiorizadas por macrófagos tratadas com o (-)\03B1-bisabolol, através da microscopia eletrônica de transmissão. Baseados nestes resultados in vitro, obtidos pelo nosso grupo, desenvolvemos três formulações tópicas contendo (-)\03B1-bisabolol com diferentes concentrações, as quais foram utilizados no tratamento da leishmaniose experimental no modelo murino. Durante o tratamento com as formulações não observamos alterações que pudessem estar relacionadas com a citotoxicidade ao tratamento tópico. Observamos que os animais tratados com a formulação contendo 1.000 mg/kg/dia de (-)\03B1-bisabolol mostraram regressão e cicatrização das lesões, com diminuição da carga parasitária. Os animais tratados com 500 mg/kg/dia e 250 mg/kg/dia de (-)\03B1-bisabolol também mostraram regressão e cicatrização das lesões, entretanto, sem diminuição da carga parasitária. Diante dos resultados analisados, podemos destacar que o (-)\03B1-bisabolol possui ação leishmanicida, dose dependente, tanto in vitro quanto in vivo, demonstrando ter eficácia no tratamento da leishmaniose experimental, o que poderá transformá-lo num composto promissor, através de um estudo futuro que possibilite aprimorar a sua capacidade leishmanicida / The treatment currently available for cutaneous leishmaniasis have problems involving its efficacy, side effects and resistance cases. In addition, all drugs are administrated parenterally. For this reason, many patients abandon the treatment, which leads to the emergence of Leishmania resistant strains. This has encouraged the search for new agents with antileishmanial features that have fewer side effects. Thus, the use of natural products derived from plants has aroused the interest of researchers in the search for alternative treatments for cutaneous leishmaniasis. Some essential oils or isolated compounds from plants have been shown, in experimental trials, an effective activity against Leishmania, which makes these compounds promising options for the treatment of this disease. Results obtained previously by our group demonstrated that (-)α-bisabolol has potent leishmanicidal activity in vitro against promastigotes and intracellular amastigotes of Leishmania amazonensis. When evaluating the cytotoxicity of this oil we demonstrated that this compound present stronger cytotoxic activity against parasites than macrophages. Furthermore, morphological and ultrastructural changes of the parasite were demonstrated by transmission electron microscopy, both in promastigotes and amastigotes treated with (-)α-bisabolol. Due to the in vitro results obtained by our group, we have developed three topical formulations containing (-) α-bisabolol with different concentrations. During treatment with the formulations changes that might be related to cytotoxicity to topical treatment were not observed. Animals treated with the formulation containing 1.000 mg/kg/day (-) α-bisabolol, showed regression and healing of the lesions with reduction in parasite load. The animals treated with 500 mg/kg/day and 250 mg/kg/day (-)α-bisabolol also showed regression and healing of the lesions, however, without reduction of the parasitic load. On the analyzed results, we emphasize that the (-) α- bisabolol has leishmanicidal action both in vitro and in vivo, showing be effective in the treatment of experimental leishmaniasis, which could turn it into a promising compound through a future study enables leishmanicidal improve its capacity. / 2017-12-02

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