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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

Aspectos comparativos da resposta inflamatória em lesões de leishmaniose cutânea

Dantas, Marina Loyola January 2012 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2013-04-19T16:30:30Z No. of bitstreams: 1 Marina Loyola Dantas Aspectos comparativos....pdf: 35265598 bytes, checksum: c8a29ec5c8fd370f04c04a980fb43507 (MD5) / Made available in DSpace on 2013-04-19T16:30:30Z (GMT). No. of bitstreams: 1 Marina Loyola Dantas Aspectos comparativos....pdf: 35265598 bytes, checksum: c8a29ec5c8fd370f04c04a980fb43507 (MD5) Previous issue date: 2012 / Universidade Federal da Bahia. Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz / A forma clínica mais frequente das leishmanioses é a leishmaniose cutânea, que acomete somente a pele e constitui um importante problema de saúde no Brasil. A leishmaniose cutânea caracteriza-se por lesão cutânea ulcerada única: leishmaniose cutânea localizada, que pode regredir espontaneamente ou se disseminar com múltiplas úlceras e pápulas e que aparecem em diferentes locais. A presença de disseminação caracteriza a leishmaniose cutânea disseminada. Investigar, no tecido, células que compõem o infiltrado inflamatório em lesões de pele na leishmaniose e caracterizar a resposta imune e sua correlação com a extensão total da inflamação in situ pode contribuir para aprofundar o entendimento da leishmaniose cutânea. Neste estudo, através da imunomarcação e quantificação de células por imunoistoquímica e HE, e análise da extensão da inflamação, foi comparado a histopatologia e presença de células inflamatórias CD4+, CD8+, CD68+, CD20+, plasmócitos e neutrófilos, e células granzima B+ em biópsias de pacientes com leishmaniose cutânea tardia (úlcera tardia e úlcera recente) e leishmaniose disseminada (úlcera e pápula). A análise dos padrões histomorfológicos mostrou semelhança entre os quatro grupos de biópsias analisados. Avaliando o número e tipo de células presentes, o predomínio foi de macrófagos e linfócitos. As úlceras da leishmaniose cutânea clássica e disseminada apresentaram média maior de inflamação, maior frequência de linfócitos T CD4+, T CD8+, macrófagos, linfócitos B CD20+ e plasmócitos que úlceras recentes e pápulas. Estas, por sua vez, ao contrário das úlceras tardias de ambas formas clínicas, tiveram correlação positiva entre o aumento do infiltrado inflamatório e T CD4+ e T CD8+, e não correlação com granzima B e neutrófilos. Os plasmócitos se mostraram elementos quase constantes no infiltrado das lesões em todos os grupos, e sua frequência foi maior que de linfócitos B. Seguindo o mesmo padrão descrito nos linfócitos B, os plasmócitos não apresentam correlação com o influxo de infiltrado inflamatório entre os grupos. A frequência de macrófagos é vista nos dois estágios avaliados da doença e nas duas formas clínicas de forma semelhante, porém com uma tendência para maior presença em lesões de LD. A análise de neutrófilos revelou semelhança da frequência dessas células em todos os tipos de lesões em ambas formas clínicas, com as pápulas tendendo para uma menor quantidade. Portanto, o desenvolvimento das lesões ocorrem com o influxo de células inflamatórias, como linfócitos T CD4+ e T CD8+ e a resposta imune celular é mais intensa em lesões crônicas da leishmaniose cutânea localizada e disseminada do que em lesões localizadas recentes e pápulas da leishmaniose disseminada. Diferenças in situ na resposta inflamatória destas duas formas clínicas e quatro espectros de lesão da leishmaniose humana podem elucidar o papel de células no local da lesão e contribuir para o entendimento da patogênese da leishmaniose. / Cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis, which affects only the skin and is an important health problem in Brazil. Cutaneous leishmaniasis is characterized by single ulcerated skin lesion: localized cutaneous leishmaniasis, which may regress spontaneously or spread with multiple ulcers and papules that appear in different parts of the body. The presence of dissemination features disseminated leishmaniasis. Investigate tissue cells from inflammatory infiltrate in skin lesions in leishmaniasis and characterize the immune response and its correlation with the total extent of inflammation in situ may contribute to deepen the understanding of cutaneous leishmaniasis. In this study, immunostaining and cells quantification by immunohistochemistry and HE and analysis of inflammation extention was compared with histopathology and CD4+, CD8+, CD68+, CD20+, plasma cells, neutrophils and granzyme B+ cells in biopsies of patients with localized cutaneous leishmaniasis (late ulcer and recent ulcer) and disseminated leishmaniasis (ulcers and papules). The histopathological patterns analysis was similar among the four biopsies groups analyzed. Macrophages and lymphocytes were the predominant cells. The ulcers of localized cutaneous leishmaniasis and disseminated leishmaniasis presented higher mean inflammation, increased frequency of CD4+ and CD8+ T cells, macrophages, B lymphocytes CD20+ and plasma cells than recent ulcers and papules. These, in turn, unlike late ulcers of both clinical forms, had positive correlation between the increase in inflammatory infiltrate and CD4+ and CD8+ T cells, differing in Granzyme B and neutrophils. Plasma cells were almost constant in lesion infiltrate in all groups and was higher than the frequency of B lymphocytes. Following the same pattern described in B lymphocytes, plasma cells did not show an association with the influx of inflammatory infiltrate between groups. The frequency of macrophages is seen in both stages of the disease and in the two clinical forms similarly, but with a tendency to be increased in disseminated lesihmaniasis lesions. The analysis revealed similarity of neutrophils frequency in all types of lesions, with papules tending to a lesser extent. Therefore, the development of lesions occur with the influx of inflammatory cells such as CD4+ and CD8+ T cells and cellular immune response is more intense in chronic lesions of localized cutaneous leishmaniasis and disseminated leishmaniasis than recent localized lesions and papules from disseminated leishmaniasis. Differences of inflammatory response in situ in these two clinical forms and four spectra of human leishmaniasis lesions may elucidate the role of cells at the lesion site and contribute to the understanding of leishmaniasis pathogenesis.
12

ModulaÃÃo imunolÃgica preventiva aplicada ao controle de infecÃÃes bacterianas por salmonella typhimurium pelo uso de lectinas / Preventive immune modulation applied to the control of bacterial infections by Salmonella typhimurium by the use of lectins

Ayrles Fernanda BrandÃo da Silva 22 April 2014 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / DoenÃas infecciosas constituem a principal causa de morte em todo o mundo. Dentre estas, as causadas por infecÃÃes bacterianas se destacam devido à diversidade de bactÃrias e à sua capacidade evolutiva e adaptativa. Respostas inflamatÃrias inadequadas estÃo associadas a essas infecÃÃes e em detrimento de avanÃos cientÃficos, o diagnÃstico precoce e o tratamento de quadros de infecÃÃes bacterianas sistÃmicas permanecem um desafio à saÃde pÃblica. Neste contexto, este estudo avaliou a capacidade da lectina de Canavalia brasiliensis (ConBr) e Cratylia argentea (CFL) em modular a inflamaÃÃo sistÃmica causada por Salmonella enterica sorotipo Typhimurium. As lectinas foram purificadas por cromatografia de afinidade em coluna de Sephadex G-50 e ensaios de avaliaÃÃo toxicolÃgica e seguranÃa farmacolÃgica foram realizados. Ambas as lectinas nÃo demonstraram toxicidade atà a mÃxima dose de 2000 mg/kg. EntÃo, camundongos foram inoculados, por via intraperitoneal, com as lectinas (10 mg/kg), 72, 48 e 24 horas antes de serem infectados com a Salmonella (107 UFC/mL). Foi observada uma sobrevida de 100% e 90% dos animais tratados com a ConBr e CFL, respectivamente, avaliados no sÃtimo dia. Este protocolo reduziu significativamente o nÃmero de bactÃrias no sangue, fluÃdo peritoneal e nos principais ÃrgÃos da infecÃÃo (baÃo e fÃgado). Foi observado ainda reversÃo da falÃncia na migraÃÃo de neutrÃfilos, leucopenia, bem como, reduÃÃo nos nÃveis de citocinas (TNF-α, IL-1 e IL-10) e Ãxido nÃtrico no soro. Foi tambÃm verificado um aumento na concentraÃÃo de Ãxido nÃtrico no fluido peritoneal e do nÃmero de plaquetas no sangue. AnÃlises in vitro mostraram que ambas as lectinas nÃo apresentam atividade bactericida, reduzem o tempo de ativaÃÃo do sistema complemento e aumentam o tempo de coagulaÃÃo intrÃnseca e extrÃnseca. As lectinas nÃo apresentaram efeito curativo quando administradas apÃs a infecÃÃo e nÃo demonstraram efeito preventivo quando inoculadas por via endovenosa ou oral. AtravÃs da anÃlise proteÃmica, proteÃnas relacionadas à infecÃÃo e à aÃÃo moduladora das lectinas foram identificadas. Assim, as lectinas possivelmente atuam sobre os macrÃfagos/monÃcitos, controlando sua ativaÃÃo, e desta forma, atenuando o processo inflamatÃrio e protegendo os animais do choque sÃptico. Estes resultados representam uma interessante perspectiva para o controle de infecÃÃes, com uso independente ou associado a antibiÃticos de aÃÃo direta sobre microrganismos / Infectious diseases are a leading cause of death throughout the world. Among these, bacterial infections stand out due to the enormous diversity of bacteria and their evolutionary and adaptive abilities. Inappropriate inflammatory responses have been associated with these infections and despite contemporaneous scientific approaches, timely diagnosis and proper treatment of systemic bacterial infection are still a challenge for public health. Thus, this study evaluated the ability of Canavalia brasiliensis (ConBr) and Cratylia argentea (CFL) lectin in modulating systemic inflammation caused by Salmonella enterica serovar Typhimurium. The lectins were purified by affinity chromatography on Sephadex G50. Toxicology and the pharmacological security of lectins was evaluated. Both lectins exhibited no toxicity up to 2000 mg/kg. Mice were inoculated intraperitoneally with lectins (10 mg/kg) within 72, 48 and 24 h before infection with Salmonella (107 CFU/mL). Animals treated with ConBr and CFL, respectively, showed 100% and 90% survival, seven days after infection. This protocol significantly reduced the bacteria in blood, peritoneal fluid and in main organs such as liver and spleen. It was also observed a reversal of the neutrophil migration failure, leukopenia, as well as reduction of cytokine levels (TNF- α, IL- 1 and IL -10) and nitric oxide on the serum. In addition, elevated peritoneal fluid concentration of nitric oxide and increase in the number of platelets were found. In vitro analyzes identified that both lectins did not exhibit antibacterial activity, can decrease the time of activation of complement system and increase intrinsic and extrinsic clotting time. Lectins had no curative effect when administered after infection and none protective effect when inoculated either intravenously or orally. Through proteomic analysis, proteins related to infection and to modulating action of lectins were identified. According to our results, we found that lectins can act on macrophages/monocytes, controlling their activation and thereby influencing the inflammatory process, protecting the animals from septic shock. These results represent an interesting approach for the control of infections, using lectins independently or associated with antibiotics whose action is directly on microorganisms.
13

Perfil epidemiológico dos pacientes com histoplasmose disseminada associada à AIDS em Goiânia-GO / Epidemiological profile of disseminated histoplasmosis patients associated with AIDS in Goiânia-GO

Silva, Thaísa Cristina 28 February 2013 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-01T12:34:48Z No. of bitstreams: 2 Dissertação - Thaísa Cristina Silva - 2014.pdf: 1534323 bytes, checksum: 4be57ed4c03026ea32f34f1f69ce1046 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-12-04T14:20:07Z (GMT) No. of bitstreams: 2 Dissertação - Thaísa Cristina Silva - 2014.pdf: 1534323 bytes, checksum: 4be57ed4c03026ea32f34f1f69ce1046 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-12-04T14:20:07Z (GMT). No. of bitstreams: 2 Dissertação - Thaísa Cristina Silva - 2014.pdf: 1534323 bytes, checksum: 4be57ed4c03026ea32f34f1f69ce1046 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-02-28 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Histoplasmosis is a systemic mycosis considered an important public health problem, especially in patients with the human immunodeficiency virus (HIV), in which the disease is associated with poor prognosis and high mortality. It has worldwide distribution with higher prevalence in tropical and temperate zones, and in Brazil has been reported more frequently in the South and Southeast. Objectives: Conduct a descriptive sociodemographic, clinical, laboratory and treatment analysis of patients with histoplasmosis and aids treated between January 2000 and June 2012, at the Hospital for Tropical Diseases - Dr. Anuar Auad (HDT). Methodology: It is a descriptive, observational, cross-sectional and retrospective study, with secondary data analysis of records filed in Sector Statistics Division and Medical File (DEAM) of HDT. All confirmed cases of disseminated histoplasmosis (HD) were sample through laboratory testing. Results: This study found a prevalence of 4.2%, which corresponds to 279 cases of AIDS associated HD. Most patients were young adult males, unmarried and with low education, and most from the interior of Goiás and urban area residents. The main occupations/professions exercised by patients were related to construction activities, home activities and rural. Regarding the signs and symptoms the most frequent were: fever (84.2%), cough (63.4%), weight loss (63.1%), dyspnea (56.3%) and asthenia (53.8 %). The diagnosis was made by blood culture (59.5%) and direct examination of peripheral blood (24.8%). Oral candidiasis, cryptococcosis and pneumocystosis were opportunistic infections associated with histoplasmosis found in these patients. Prevalent laboratory findings were hemoglobin < 10 g/dL (61.2%), platelets > 100,000 cells/mm3 (60.6%), creatinine < 1.5 mg/dL (75.9%), aspartate aminotransferase (AST) ≥ 45 UI/L (76.2%), lactate dehydrogenase (LDH) ≥ 480 UI/L (79.1%) and CD4 cell count below 150 cells/mm3 in 85.9% of patients. After diagnosis, 86.7% of patients were treated with amphotericin B, and 70.3% died and the fatality rate presented was 6.45%. When analyzed risk factors associated with death from HD no variable was significant. Conclusion: Histoplasmosis showed high prevalence and lethality in AIDS patients in Goiânia, showing the need to adopt actions to facilitate early diagnosis, proper treatment and thus improved prognosis. / A histoplasmose é uma micose sistêmica considerada um importante problema de saúde pública, especialmente em portadores do vírus da imunodeficiência adquirida (HIV), nos quais a doença está associada com mau prognóstico e alta mortalidade. Possui distribuição mundial, com maior prevalência em zonas tropicais e temperadas, e no Brasil tem sido relatada frequentemente nas regiões Sul e Sudeste. Objetivos: Realizar análise descritiva dos aspectos sociodemográficos, clínicos, laboratoriais e terapêuticos nos pacientes com histoplasmose e aids atendidos entre janeiro de 2000 a junho de 2012, no Hospital de Doenças Tropicais - Dr. Anuar Auad (HDT). Metodologia: Trata-se de um estudo descritivo, observacional, transversal e retrospectivo, com análise de dados secundários dos prontuários arquivados no Setor de Divisão de Estatística e Arquivo Médico (DEAM) do HDT. Foram incluídos na amostra todos os casos confirmados de histoplasmose disseminada (HD) por meio de exame laboratorial. Resultados: Neste estudo foi encontrada uma prevalência de 4,2%, o que corresponde a 279 casos de HD associada a aids. A maioria dos pacientes eram homens adultos jovens, solteiros e com baixa escolaridade, principalmente do interior de Goiás e residentes em áreas urbanas. As principais ocupações/profissões exercidas pelos pacientes foram atividades relacionadas à construção civil, atividades do lar e rurais. Em relação aos sinais e sintomas, os mais frequentes foram: febre (84,2%), tosse (63,4%), perda de peso (63,1%), dispneia (56,3%) e astenia (53,8%). O diagnóstico foi realizado através de hemocultura (59,5%) e exame direto de sangue periférico (24,8%). Candidíase oral, pneumocistose e criptococcose foram infecções oportunísticas encontradas associadas à histoplasmose nestes pacientes. Os achados laboratoriais prevalentes foram hemoglobina < 10 g/dL (61,2%), plaquetas > 100.000 células/mm3 (60,6%), creatinina < 1,5 mg/dL (75,9%), aspartato aminotransferase (AST) ≥ 45 UI/L (76,2%), desidrogenase lática (DHL) ≥ 480 UI/L (79,1%) e contagem de células CD4 inferior a 150 células/mm3 em 85,9% dos pacientes. Após o diagnóstico, 86,7% dos pacientes foram tratados com anfotericina B, dos quais 70,3% evoluíram para óbito com taxa de letalidade de 6,45%. Quando analisados fatores de risco associados ao óbito por HD nenhuma variável foi significativa. Conclusão: A histoplasmose apresentou alta prevalência e letalidade em pacientes com aids em Goiânia, mostrando a necessidade de adotar medidas para facilitar o diagnóstico precoce, tratamento adequado e, consequentemente, melhorar o prognóstico.
14

Disseminated sporotrichosis in an immunocompetent patient

Hassan, Kareem, Turker, Tolga, Zangeneh, Tirdad 31 May 2016 (has links)
Sporothrix schenckii, the causative agent of sporotrichosis, is a relatively rare infection. Local infection usually occurs through direct inoculation of the organism through the skin; disseminated disease is rarely seen. This article describes a case of disseminated sporotrichosis in a middle-aged man without the commonly seen risk factors for dissemination.
15

Wird der szintigrafische Befund der disseminierten Schilddrüsenautonomie durch mangelnde Sensitivität der TSHRAK- Assays, intrathyreoidalen Iodmangel, Schilddrüsenvergrößerung oder TSH-Rezeptor-Keimbahnmutationen verursacht?: Wird der szintigrafische Befund der disseminierten Schilddrüsenautonomie durch mangelnde Sensitivität der TSHRAK-Assays, intrathyreoidalen Iodmangel, Schilddrüsenvergrößerung oder TSH-Rezeptor-Keimbahnmutationen verursacht?

Schmidt, Claudia 15 March 2012 (has links)
Das Krankheitsbild der disseminierten Schilddrüsen(SD)-Autonomie ist nur in Mitteleuropa bekannt und wird in der englischsprachigen Literatur nicht beschrieben. Die exakte Pathogenese der disseminierten SD-Autonomie, insbesondere ob es sich um ein eigenständiges Krankheitsbild oder nur um ein szintigrafisches Phänomen handelt, ist nicht geklärt. Daher war es Ziel dieser Arbeit, die klinische Entität der disseminierten Autonomie genauer zu klassifizieren, mit anderen SD-Autonomien zu vergleichen und weitere Erkenntnisse über die Pathogenese, insbesondere bezüglich des intrathyreoidalen Iodgehalts sowie TSH-Rezeptorkeimbahnmutationen dieser Erkrankung zu gewinnen.
16

Acute Kidney Injury, Immune Thrombocytopenic Purpura, and the Infection That Binds Them Together: Disseminated Histoplasmosis

Sethi, Pooja, Treece, Jennifer, Onweni, Chidinma, Pai, Vandana, Arikapudi, Sowminya, Kallur, Lakshmi, Kohli, Varun, Moorman, Jonathan 01 December 2017 (has links)
Untreated human immunodeficiency virus (HIV) can be complicated by opportunistic infections, including disseminated histoplasmosis (DH). Although endemic to portions of the United States and usually benign, DH can rarely act as an opportunistic infection in immunocompromised patients presenting with uncommon complications such as acute kidney injury and idiopathic thrombocytopenic purpura. We report a rare presentation of DH presenting with acute kidney injury and immune thrombocytopenic purpura in an immunocompromised patient with HIV.
17

Identification of Multiple Levels of Trauma Induced Coagulopathy

Newton, Jason 24 June 2013 (has links)
Trauma continues to be a major cause of death across the globe. While the exact causes of trauma differ greatly between the military and civilian lifestyles, the ability to stop bleeding after trauma is paramount for survival. Over the past decade coagulation research has transitioned from a classical understanding of plasma based protein coagulation to the current cell focused research. As part of this shift, platelets have become a central player in hemostasis. Unfortunately little is currently understood about how platelet function is affected by trauma. In an effort to better define platelet function during trauma and the resulting shock from exsanguination, a multipronged approach was developed. The hypothesis that the introduction of a state of clinical shock in a controlled environment would allow for an in-depth assessment of trauma-induced coagulopathy led to the development of a swine based model of hemorrhagic shock. In this model a composite injury consisting of soft tissue damage, long bone fracture, and controlled hemorrhage was used to induce a moderate state of hypovolemic shock. As a result of this injury the animals showed both the beginning of a plasma protein consumption coagulopathy as well as kinetic quickening in the clotting process. These surprising results show competing up-regulation and down-regulation of the coagulation system in response to trauma induced shock. To better define the effect of polytrauma on platelet function in a human population a clinical study was conducted. The hypothesis behind the development of this study was that the examination of platelet function during polytrauma would lead to a more complete understanding of the effects of trauma on hemostasis. This study resulted in the identification of two separate but not mutually exclusive coagulopathies in response to trauma. The first was the traditional consumption based coagulopathies recently suggested to be varying degrees of disseminated intravascular coagulopathy. The second was a development a hypercoagulable state that may be attributed to increased platelet function. The identification of these two competing coagulopathies in separate models highlights the inadequacies of the current plasma based clinical testing, and the need for increased whole blood testing in the trauma treatment environment.
18

OBSERVED GAS HYDRATE MORPHOLOGIES IN MARINE SEDIMENTS

Holland, Melanie, Schultheiss, Peter, Roberts, John, Druce, Matthew 07 1900 (has links)
Small-scale morphology of gas hydrate is important for understanding the formation of gas hydrate deposits, for estimating the concentrations of gas hydrate from geophysical data, and for predicting their response to climate change or commercial production. The recent use of borehole pressure coring tools has allowed marine gas-hydrate-bearing sediments to be recovered with centimeter to sub-millimeter gas hydrate structures preserved in their in situ condition. Once these sediment samples are recovered at in situ temperature and pressure, nondestructive analyses, including gamma density, P-wave velocity, and X-ray imaging, are used to examine the character of the gas hydrate relative to the structure of the surrounding sediment. Gas hydrate morphology from pressure core data is summarized from the recent national gas hydrate expeditions of India, China, and Korea, as well as from Ocean Drilling Program Leg 204, Integrated Ocean Drilling Program Expedition 311, and the Gulf of Mexico Chevron-Texaco Joint Industry Project. The most striking result is the variability of gas hydrate morphology in clay, ranging from complex vein structures to an invisible pore-filling matrix. Both of these morphologies have been observed in clay sediments at gas hydrate saturations equivalent to 30-40% of pore volume. A clear knowledge of detailed gas hydrate morphology will provide important data to help determine the mechanisms of gas hydrate deposit formation and also provide crucial data for modeling the kinetics of deposit dissociation, from both natural and artificial causes. The morphology also has large effects on sedimentary physical properties, from seismic velocities on a large scale to borehole electrical resistivities on a smaller scale, and gas hydrate morphology will therefore impact estimation of gas hydrate saturation from geophysical data. The detailed morphology of gas hydrate is an essential component for a full understanding of the past, present, and future of any gas hydrate environment.
19

Modelagem farmacocinética-farmacodinâmica do antifúngico voriconazol

Araújo, Bibiana Verlindo de January 2008 (has links)
Objetivos: O objetivo deste trabalho foi o desenvolvimento de um modelo farmacocinético/farmacodinâmico (PK/PD) para descrever o efeito antifúngico voriconazol (VRC) contra espécies de Candida. Método: Para alcançar este objetivo as seguintes etapas foram realizadas: i) foi adaptado e padronizado modelo de candidíase disseminada em ratos Wistar imunocompetentes e imunocomprometidos com Candida sp.; ii) foram validados métodos analíticos de LC-MS/MS e LC-UV para o doseamento do VRC em amostras de plasma e microdialisado de tecido; iii) foram estabelecidas as condições para microdiálise do VRC e as taxas de recuperação in vitro, por perda e ganho, e em tecido renal in vivo, por retrodiálise, foram determinadas; iv) foi avaliada a PK não-linear do VRC após administração i.v. bolus das doses de 2,5, 5 e 10 mg/kg e a biodisponibilidade oral foi determinada em roedores; v) a penetração renal do VRC após administração oral das doses de 40 e 60 mg/kg foi determinada em ratos Wistar sadios e infectados com C. albicans ou C. krusei; e (vi) o perfil fungistático do VRC contra C. albicans e C. krusei foi determinado utilizando modelo de infecção experimental in vitro onde foram simuladas as concentrações livres renais do VRC esperadas em humanos após administração oral e i.v. de diferentes posologias. Os dados de cinética e dinâmica obtidos foram modelados com equação de Emax modificada, com auxílio do Scientist®. Resultados e Conclusões: i) O modelo de candidíase disseminada foi adaptado com sucesso para ratos Wistar. C. albicans apresentou maior virulência com Log UFC/g de tecido renal de 5,51 ± 0,56 e 7,29 ± 0,26, após 2 e 7 dias de infecção em animais imunocompetentes, respectivamente. Em animais imunocomprometidos a contagem foi de 6,43 ± 0,59 Log UFC/g após 2 dias de infecção, com morte de todo o grupo dentro de 4 dias. As espécies não-albicans (C. krusei e C. glabrata) apresentaram um perfil de infecção semelhante em animais imunocompetentes (Log UFC/g = 2,98 ± 0,27 para C. krusei e 2,48 ± 0,46 para C. glabrata). Entretanto, nos animais imunocomprometidos, C. krusei promoveu morte de todo o grupo em até 7 dias, enquanto C. glabrata causou apenas um aumento no grau de infecção (Log UFC/g = 6,98 ± 0,48). ii) Os métodos analíticos por LC-UV e LCMS/ MS para quantificação do VRC foram validados. As curvas de calibração foram lineares na faixa de 50 a 2500 ng/mL (r > 0,98) para ambos os métodos. Os ensaios de precisão intra e inter-dia foram > 94,9 e 95,8 %, para microdialisado por HPLC-UV e > 87,5 e 92,3 % para LC-MS/MS em plasma, respectivamente. A exatidão foi > 89,1 % para HPLC-UV e > 88,4 % para LC-MS/MS. iii) A avaliação do VRC por microdiálise mostrou que a recuperação é concentração independente (0,1–2,0 μg/mL). O VRC entretanto, devido a sua moderada lipofilia, liga-se às tubulações do sistema de microdiálise, gerando diferenças entre a recuperação determinada pelo método de perda (retrodiálise) e de ganho (diálise) in vitro, as quais puderam ser corrigidas após o cálculo do coeficiente de ligação do fármaco ao sistema. A recuperação in vivo após correção da ligação ao sistema foi de 24,5 ± 2,8 % iv) A análise dos perfis de plasmáticos do VRC obtidos em ratos Wistar após administração oral mostrou comportamento não-linear, compatível com saturação de eliminação. A avaliação compartimental dos perfis i.v. de diferentes doses, utilizando modelo de três compartimentos com eliminação de Michaelis-Menten, permitiu a determinação da constante de Michaelis (KM) de 0,58 μg/mL e da velocidade máxima da eliminação (VM) de 2,63 μg/h, em média. A modelagem simultânea dos dados plasmáticos (40 mg/kg) e i.v. (10 mg/kg) permitiu a determinação da biodisponibilidade oral do VRC em ratos, que foi de 82,8%. v) A fração de penetração renal do VRC, determinada por microdiálise em ratos sadios e infectados, foi de 0,34 ± 0,01, similar a fração livre do fármaco no plasma (0,34), indicando que as concentrações livres renais de VRC são semelhantes às concentrações livres plasmáticas e que as mesmas não se modificam devido a infecções causadas por Candida sp. vi) Os parâmetros da modelagem PK/PD do efeito do VRC contra espécies de Candida em modelo de infecção experimental in vitro obtidos foram: CE50 de 2,96 μg/mL e Kmax = 0,26 h-1 para C. albicans e CE50 de 3,47 μg/mL e Kmax = 0,51 h-1 para C. krusei. Houve diferença estatística apenas no Kmax para as duas espécies (α = 0,05) indicando uma maior suscetibilidade da C. krusei ao VRC. O modelo PK/PD de Emax modificado utilizado foi capaz de descrever adequadamente os perfis de inibição do crescimento de Candida sp em função do tempo, para todos os regimes terapêuticos do VRC avaliados, podendo ser usado para otimização da terapia com esse fármaco. / Objectives: The aim of this work was the development of a pharmacokineticpharmacodynamic model (PK/PD) to describe the fungistatic effect of voriconazole (VRC) against Candida species. Method: To reach this objective, the following steps were done: i) a disseminated candidiasis model to immunocompetent and immunocompromised Wistar rats with Candida sp was adapted and standardized; ii) analytical methods of LC-MS/MS and LC-UV for measurement of VRC in plasma and microdialysate tissue samples were validated; iii) microdialysis conditions of VRC and the recoveries rate in vitro, by loss and gain, in renal tissue in vivo, by retrodialysis, were determined; iv) the non-linear PK of VRC after i.v. bolus administration of 2.5, 5 e 10 mg/kg doses were evaluated and the oral bioavailability in rodents was estimated; v) tissue penetration of VRC after oral administration of 40 and 60 mg/kg was determined in healthy and infected by C. albicans or C. krusei Wistar male rats; vi) the fungistatic profile of VRC against C. albicans and C. krusei was determined using a experimental infection model in vitro, where the free renal concentrations of VRC expected in humans after oral and iv administration of different dosing regimens were simulated. The kinetic and dynamic data obtained were modeled using an Emax modified model, with aid of Scientist®. Results and Conclusions: i) The disseminated candidiasis model was successfully adapted to Wistar rats. C. albicans showing high virulence with Log CFU/g of renal tissue of 5.51 ± 0.56 and 7.29 ± 0.26, after 2 and 7 days of infection in immunocompetent animals, respectively. In immunocompromised animals, the counting was 6.43 ± 0.59 Log CFU/g after 2 days of infection, with whole group death within 4 days. Non-albicans especies (C. krusei e C. glabrata) showed a similar infection profile in immunocompetent and immunocompromised animals (Log CFU/g = 2.98 ± 0.27 to C. krusei e 2.48 ± 0.46 to C. glabrata). However, in immunocompromised animals, C. krusei causes death in the whole group up to 7 days, instead, C. glabrata causes only a low increase in the infection degree (Log CFU/g = 6.98 ± 0.48). ii) The analytical methods of HPLC-UV and LC-MS/MS to VRC quantification were validated. Linearity was between 50 - 2500 range ng/mL (r > 0.98) for both methods. The intra and inter-day precision assays were > 94.9 e 95.8 %, for microdialysate using LC-UV and > 87.5 e 92.3 % using LCxx MS/MS for plasma, respectively. The accuracy was > 89.1 % for HPLC-UV and > 88.4 % for LC-MS/MS. iii) The evaluation of VRC by microdialysis showed that recovery is concentration independent (0.1–2 μg/mL). VRC, however, due to its moderate lipophilic characteristic, binds to the microdialysis system tubing’s, generating differences between recoveries determined by loss (retrodialysis) and gain (dialysis) in vitro methods, which could be corrected after determination of drug’s binding coefficient to the system. The in vivo recovery determined after correction of system binding was 24.5 ± 2.8 %. iv) VRC plasma profiles analysis obtained from Wistar rats after oral administration showed a nonlinear behavior, compatible with saturable elimination. The compartmental evaluation of i.v. profiles in different doses, employing the a compartment model with Michaelis-Menten elimination, allowed to determine the Michaelis-Menten constant (KM) of 0.58 μg/mL and the maximum velocity (VM) of 2.63 μg/h, in average. The simultaneous modeling of oral (40 mg/kg) and iv (10 mg/kg) plasma data allowed the determination of the oral bioavailability of VRC in rats, equal to 82.8%. v) The VRC renal penetration fraction, determined by microdialysis in healthy and infected rats, was 0.34 ± 0.01, similar to the free unbound fraction in plasma (0.34), showing that VRC free renal concentration levels are similar to the unbound plasma concentrations and that did not change due the infection associated to Candida sp. vi) The parameters of PK-PD modeling of VRC effect against Candida species in the in vitro experimental infection model obtained were: EC50 de 2.97 μg/mL and Kmax = 0.203 h−1 to C. albicans and EC50 of 3.47 μg/mL and Kmax = 0.51 h−1 to C. krusei. There is a statistical difference only in Kmax value for the two species (α = 0.05), showing a higher susceptibility of C. krusei to VRC. The PK/PD Emax modified model employed was able to describe adequately the growth inhibition profiles of Candida sp in function of time, for all VRC dosing regimens evaluated, and can be used for therapy optimization with this drug.
20

Modelagem farmacocinética-farmacodinâmica do antifúngico voriconazol

Araújo, Bibiana Verlindo de January 2008 (has links)
Objetivos: O objetivo deste trabalho foi o desenvolvimento de um modelo farmacocinético/farmacodinâmico (PK/PD) para descrever o efeito antifúngico voriconazol (VRC) contra espécies de Candida. Método: Para alcançar este objetivo as seguintes etapas foram realizadas: i) foi adaptado e padronizado modelo de candidíase disseminada em ratos Wistar imunocompetentes e imunocomprometidos com Candida sp.; ii) foram validados métodos analíticos de LC-MS/MS e LC-UV para o doseamento do VRC em amostras de plasma e microdialisado de tecido; iii) foram estabelecidas as condições para microdiálise do VRC e as taxas de recuperação in vitro, por perda e ganho, e em tecido renal in vivo, por retrodiálise, foram determinadas; iv) foi avaliada a PK não-linear do VRC após administração i.v. bolus das doses de 2,5, 5 e 10 mg/kg e a biodisponibilidade oral foi determinada em roedores; v) a penetração renal do VRC após administração oral das doses de 40 e 60 mg/kg foi determinada em ratos Wistar sadios e infectados com C. albicans ou C. krusei; e (vi) o perfil fungistático do VRC contra C. albicans e C. krusei foi determinado utilizando modelo de infecção experimental in vitro onde foram simuladas as concentrações livres renais do VRC esperadas em humanos após administração oral e i.v. de diferentes posologias. Os dados de cinética e dinâmica obtidos foram modelados com equação de Emax modificada, com auxílio do Scientist®. Resultados e Conclusões: i) O modelo de candidíase disseminada foi adaptado com sucesso para ratos Wistar. C. albicans apresentou maior virulência com Log UFC/g de tecido renal de 5,51 ± 0,56 e 7,29 ± 0,26, após 2 e 7 dias de infecção em animais imunocompetentes, respectivamente. Em animais imunocomprometidos a contagem foi de 6,43 ± 0,59 Log UFC/g após 2 dias de infecção, com morte de todo o grupo dentro de 4 dias. As espécies não-albicans (C. krusei e C. glabrata) apresentaram um perfil de infecção semelhante em animais imunocompetentes (Log UFC/g = 2,98 ± 0,27 para C. krusei e 2,48 ± 0,46 para C. glabrata). Entretanto, nos animais imunocomprometidos, C. krusei promoveu morte de todo o grupo em até 7 dias, enquanto C. glabrata causou apenas um aumento no grau de infecção (Log UFC/g = 6,98 ± 0,48). ii) Os métodos analíticos por LC-UV e LCMS/ MS para quantificação do VRC foram validados. As curvas de calibração foram lineares na faixa de 50 a 2500 ng/mL (r > 0,98) para ambos os métodos. Os ensaios de precisão intra e inter-dia foram > 94,9 e 95,8 %, para microdialisado por HPLC-UV e > 87,5 e 92,3 % para LC-MS/MS em plasma, respectivamente. A exatidão foi > 89,1 % para HPLC-UV e > 88,4 % para LC-MS/MS. iii) A avaliação do VRC por microdiálise mostrou que a recuperação é concentração independente (0,1–2,0 μg/mL). O VRC entretanto, devido a sua moderada lipofilia, liga-se às tubulações do sistema de microdiálise, gerando diferenças entre a recuperação determinada pelo método de perda (retrodiálise) e de ganho (diálise) in vitro, as quais puderam ser corrigidas após o cálculo do coeficiente de ligação do fármaco ao sistema. A recuperação in vivo após correção da ligação ao sistema foi de 24,5 ± 2,8 % iv) A análise dos perfis de plasmáticos do VRC obtidos em ratos Wistar após administração oral mostrou comportamento não-linear, compatível com saturação de eliminação. A avaliação compartimental dos perfis i.v. de diferentes doses, utilizando modelo de três compartimentos com eliminação de Michaelis-Menten, permitiu a determinação da constante de Michaelis (KM) de 0,58 μg/mL e da velocidade máxima da eliminação (VM) de 2,63 μg/h, em média. A modelagem simultânea dos dados plasmáticos (40 mg/kg) e i.v. (10 mg/kg) permitiu a determinação da biodisponibilidade oral do VRC em ratos, que foi de 82,8%. v) A fração de penetração renal do VRC, determinada por microdiálise em ratos sadios e infectados, foi de 0,34 ± 0,01, similar a fração livre do fármaco no plasma (0,34), indicando que as concentrações livres renais de VRC são semelhantes às concentrações livres plasmáticas e que as mesmas não se modificam devido a infecções causadas por Candida sp. vi) Os parâmetros da modelagem PK/PD do efeito do VRC contra espécies de Candida em modelo de infecção experimental in vitro obtidos foram: CE50 de 2,96 μg/mL e Kmax = 0,26 h-1 para C. albicans e CE50 de 3,47 μg/mL e Kmax = 0,51 h-1 para C. krusei. Houve diferença estatística apenas no Kmax para as duas espécies (α = 0,05) indicando uma maior suscetibilidade da C. krusei ao VRC. O modelo PK/PD de Emax modificado utilizado foi capaz de descrever adequadamente os perfis de inibição do crescimento de Candida sp em função do tempo, para todos os regimes terapêuticos do VRC avaliados, podendo ser usado para otimização da terapia com esse fármaco. / Objectives: The aim of this work was the development of a pharmacokineticpharmacodynamic model (PK/PD) to describe the fungistatic effect of voriconazole (VRC) against Candida species. Method: To reach this objective, the following steps were done: i) a disseminated candidiasis model to immunocompetent and immunocompromised Wistar rats with Candida sp was adapted and standardized; ii) analytical methods of LC-MS/MS and LC-UV for measurement of VRC in plasma and microdialysate tissue samples were validated; iii) microdialysis conditions of VRC and the recoveries rate in vitro, by loss and gain, in renal tissue in vivo, by retrodialysis, were determined; iv) the non-linear PK of VRC after i.v. bolus administration of 2.5, 5 e 10 mg/kg doses were evaluated and the oral bioavailability in rodents was estimated; v) tissue penetration of VRC after oral administration of 40 and 60 mg/kg was determined in healthy and infected by C. albicans or C. krusei Wistar male rats; vi) the fungistatic profile of VRC against C. albicans and C. krusei was determined using a experimental infection model in vitro, where the free renal concentrations of VRC expected in humans after oral and iv administration of different dosing regimens were simulated. The kinetic and dynamic data obtained were modeled using an Emax modified model, with aid of Scientist®. Results and Conclusions: i) The disseminated candidiasis model was successfully adapted to Wistar rats. C. albicans showing high virulence with Log CFU/g of renal tissue of 5.51 ± 0.56 and 7.29 ± 0.26, after 2 and 7 days of infection in immunocompetent animals, respectively. In immunocompromised animals, the counting was 6.43 ± 0.59 Log CFU/g after 2 days of infection, with whole group death within 4 days. Non-albicans especies (C. krusei e C. glabrata) showed a similar infection profile in immunocompetent and immunocompromised animals (Log CFU/g = 2.98 ± 0.27 to C. krusei e 2.48 ± 0.46 to C. glabrata). However, in immunocompromised animals, C. krusei causes death in the whole group up to 7 days, instead, C. glabrata causes only a low increase in the infection degree (Log CFU/g = 6.98 ± 0.48). ii) The analytical methods of HPLC-UV and LC-MS/MS to VRC quantification were validated. Linearity was between 50 - 2500 range ng/mL (r > 0.98) for both methods. The intra and inter-day precision assays were > 94.9 e 95.8 %, for microdialysate using LC-UV and > 87.5 e 92.3 % using LCxx MS/MS for plasma, respectively. The accuracy was > 89.1 % for HPLC-UV and > 88.4 % for LC-MS/MS. iii) The evaluation of VRC by microdialysis showed that recovery is concentration independent (0.1–2 μg/mL). VRC, however, due to its moderate lipophilic characteristic, binds to the microdialysis system tubing’s, generating differences between recoveries determined by loss (retrodialysis) and gain (dialysis) in vitro methods, which could be corrected after determination of drug’s binding coefficient to the system. The in vivo recovery determined after correction of system binding was 24.5 ± 2.8 %. iv) VRC plasma profiles analysis obtained from Wistar rats after oral administration showed a nonlinear behavior, compatible with saturable elimination. The compartmental evaluation of i.v. profiles in different doses, employing the a compartment model with Michaelis-Menten elimination, allowed to determine the Michaelis-Menten constant (KM) of 0.58 μg/mL and the maximum velocity (VM) of 2.63 μg/h, in average. The simultaneous modeling of oral (40 mg/kg) and iv (10 mg/kg) plasma data allowed the determination of the oral bioavailability of VRC in rats, equal to 82.8%. v) The VRC renal penetration fraction, determined by microdialysis in healthy and infected rats, was 0.34 ± 0.01, similar to the free unbound fraction in plasma (0.34), showing that VRC free renal concentration levels are similar to the unbound plasma concentrations and that did not change due the infection associated to Candida sp. vi) The parameters of PK-PD modeling of VRC effect against Candida species in the in vitro experimental infection model obtained were: EC50 de 2.97 μg/mL and Kmax = 0.203 h−1 to C. albicans and EC50 of 3.47 μg/mL and Kmax = 0.51 h−1 to C. krusei. There is a statistical difference only in Kmax value for the two species (α = 0.05), showing a higher susceptibility of C. krusei to VRC. The PK/PD Emax modified model employed was able to describe adequately the growth inhibition profiles of Candida sp in function of time, for all VRC dosing regimens evaluated, and can be used for therapy optimization with this drug.

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