Orientador: Cláudio Antonio Rabello Coelho / Resumo: Na colestase crônica experimental obstrutiva em ratos, ocorre diminuição progressiva do parênquima hepático e, consequentemente, prejuízo das funções hepáticas. A absorção da vitamina lipossolúvel A, depende da presença de ácidos biliares na luz intestinal e, assim, está prejudicada na colestase. A deficiência de vitamina A prejudica as defesas antioxidantes, facilitando as lesões hepáticas intermediadas por radicais livres. Além disso, a lesão do parênquima hepático prejudica a síntese de proteínas ligadoras de retinol (R.B.P.), sua liberação para o sangue e, em consequência, a liberação de V.A. das reservas hepáticas. Nosso objetivo foi testar se a administração de vitamina A hidromiscível interfere com os efeitos da colestase sobre a estrutura e a função do fígado. Para tanto, estudamos 1) níveis séricos da V.A.; 2) mortalidade espontânea num período de 49 dias de colestase; 3) mortalidade após administração de 0,5mg de pentobarbital/g de peso do animal por via intra-peritoneal no 48o dia de colestase; 4) intensidade da fibrose e inflamação hepáticas além da proliferação ductal em 134 ratos machos da raça Wistar desmamados aos 21 dias... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In experimental chronic obstructive cholestasis there is a progressive atrophy of the hepatic parenchima and, therefore, an impairment in hepatic function. Cholestasis is frequently associated with deficiency of the fat-soluble-vitamins A,D,E,K because the intraluminal solubilization and absorption of ingested lipids requires an adequate bile flow. The hepatic dammage secondary to biliary obstruction impairs the hepatic sinthesis and delivery of retinol binding protein (RBP). In consequence, there is an impairment in the delivery of V.A. from the hepatic stores and its supply to the target tissues. Its deficiency diminishes the antioxidative potential enhancing liver dammage mediated by oxygen free radicals. Our aim was to analyse the effects of two factors: 1) cholestasis and 2) the administration of an hidromiscible V.A. and their interaction using male 21 days old Wistar rats submited to double ligature and ressection of the common bile duct or sham-operated as regards 1) the serum levels of V.A., 2) espontaneous mortality; 3) mortality after pentobarbital; 3) intensity of hepatic fibrosis, inflamation and ductal proliferation... (Complete abstract click electronic address below) / Mestre

Adverse reactions to the antiarrhythmic medication amiodarone are severe, potentially life-threatening, and not rare. One in three patients on long-term therapy experience elevated liver enzymes, and clinically apparent liver toxicity occurs in 1% of patients treated. We report the case of a 76-year-old patient with amiodarone-induced intrahepatic cholestasis and prolonged hyperbilirubinemia despite the discontinuation of the offending agent. Current research hypothesizes that amiodarone leads to hepatic injury both by direct hepatotoxicity and by increasing the likelihood of hepatocytes to create abnormal, toxic metabolites. Increased awareness of such an adverse effect can guide clinicians toward the possible underlying etiologies of prolonged jaundice.

Introduction Estrogen-induced cholestasis is a disease characterized by a failure of bile flow and bile production. It can develop in women after oral contraceptives use, hormone replacement therapy or during pregnancy. The estrogen metabolism is a complex process leading to formation of metabolites with different biological activities. It takes place primarily in the liver (Phase I and Phase II including hydroxylation, methylation, sulfation and glucuronidation). The enzymes from UDP-glucuronosyltransferases family , abbreviated UGT, are responsible for the glucuronidation of estrogens. Aims The objective of my work is to define estrogen metabolism and gene expression of UGT1A1, CYP1A2 and SULT1A1 and characterize cholestatic liver damage in the UGT1A1 deficient rat strain (Gunn rats) compared to rats with normal enzyme activity and try to define possible mechanisms responsible for the liver damage. Methods Adult female Gunn and corresponding heterozygous rats were treated with ethinylestradiol (EE, 5 mg/kg body weight SC) for 5 days, while control rats received propanediol (vehicle). Day six, the animals were sacrificed and plasma and liver tissue were collected for analysis. Markers of cholestasis and liver damage ALP, AST, ALT and bilirubin were determined using an automatic analyzer, total...

Introdução: As estenoses biliares são sempre desafiadoras, tanto no diagnóstico como na conduta terapêutica aplicada, seja ela curativa ou paliativa. A obtenção de espécimes se faz necessária uma vez que muitas doenças benignas mimetizam as neoplasias biliopancreáticas, tornando o diagnóstico anatomopatológico fundamental. Apesar da baixa acurácia, a colangiopancreatografia retrógrada endoscópica (CPRE) é o método tradicionalmente utilizado para diagnosticar estenoses biliares por meio do escovado citológico e da biópsia transpapilar. Por outro lado, diversos estudos têm reportado acurácia satisfatória da ecoendoscopia com punção aspirativa com agulha fina (EE-PAAF). Este estudo propõe comparar prospectivamente esses métodos no diagnóstico anatomopatológico da estenose biliar com suspeita de origem maligna. Métodos: Após a realização do cálculo amostral, 50 pacientes com estenoses biliares com suspeita maligna foram submetidos à CPRE com escovado citológico e biópsia transpapilar e à EE-PAAF durante a mesma sedação ou com intervalo máximo de sete dias. O padrão-ouro do resultado anatomopatológico dos métodos foram a cirurgia e o seguimento clínico por pelo menos seis meses. Foram avaliados os índices de acurácia (sensibilidade, especificidade, valor preditivo positivo e negativo, razão de verossimilhança positiva e negativa e acurácia), de concordância e as complicações entre os métodos, além da realização de subanálises, incluindo avaliação de técnicas, localização anatômica e tamanho da lesão. Resultados: O diagnóstico anatomopatológico obtido na associação dos dois métodos nos 50 pacientes (26 mulheres e 24 homens, com média de idade de 63,08 anos) foram: 47 malignos, um suspeito para malignidade e dois benignos. O diagnóstico definitivo definido pelo padrão-ouro demonstrou 48 estenoses malignas e duas benignas. O tamanho médio das lesões foi 3,48 cm, sendo 31 lesões extraductais e 19 intraductais, bem como 35 distais e 15 proximais. Na análise por intenção de tratamento, sensibilidade, especificidade e acurácia da EE foram superiores aos resultados da CPRE (93,8%, 100% e 94% contra 60,4%, 100% e 62%, respectivamente) (p = 0,034) com índices de complicações semelhantes. Não houve concordância entre os métodos e a combinação deles aumentou a sensibilidade e acurácia para 97,9% e 98%, respectivamente. Nas subanálises, a EE foi superior à CPRE tanto nas lesões extraductais com acurácia de 100% contra 54,8%, p=0,019, quanto nas lesões maiores que 1,5 cm (95,8% contra 61,9%, p=0,031). Entretanto os resultados foram semelhantes nas lesões intraductais e nas menores que 1,5 cm. Não houve diferença significativa entre os métodos nas análises de lesões proximais, distais e pancreáticas. Nas subanálises das técnicas empregadas, o escovado citológico e a biópsia transpapilar apresentaram resultados semelhantes entre si, tal como as técnicas de capilaridade e vácuo. Conclusão: A EE-PAAF é superior à CPRE associada ao escovado citológico e à biópsia transpapilar, com índices de complicações semelhantes. Não há concordância entre os métodos e a associação deles aumenta os índices de acurácia. A EE-PAAF é superior à CPRE com obtenção de espécimes na avaliação de lesões extraductais e nas maiores que 1,5 cm e é semelhante nas intraductais e nas menores que 1,5 cm. O escovado citológico e a biópsia transpapilar apresentam resultados semelhantes entre si, tal como as técnicas de capilaridade e vácuo. Não há diferença entre os métodos nas análises individuais de lesões distais, proximais e pancreáticas / Background and Aims: Biliary strictures are always a challenging clinical scenario and the anatomopathological diagnosis is essential in the therapeutic management, whether for curative or palliative purposes. The acquisition of specimens is necessary since many benign diseases mimic biliopancreatic neoplasms. Endoscopic retrograde cholangiopancreatography (ERCP) is the traditionally used method, despite its low accuracy based on biliary brush cytology and forceps biopsy. On the other hand, several studies reported good accuracy rates using endoscopic ultrasound guided-fine needle aspiration (EUS-FNA). The aim of this prospective study is to compare the accuracy of EUS and ERCP for tissue sampling of biliary strictures. Methods: After performing the sample calculation, fifty consecutive patients with indeterminate biliary strictures were included to undergo ERCP and EUS procedures on the same sedation or with a maximum interval of 7 days. The gold standard method was surgery or six months\' follow-up. Evaluation of the accuracy indices (sensitivity, specificity, positive and negative predictive value, positive and negative likelihood ratio and accuracy), concordance and adverse events among the methods were performed. Also, subtype analyses of the techniques evaluation, anatomical localization and size of the lesion were included. Results: The final diagnosis reported in 50 patients (26 Female and 24 Male with a mean age of 63.08 years old) was 47 malignant, one suspicious for malignance and two benign lesions. Thirty-one lesions were extraductal and 19 intraductal, 35 were distal and 15 proximal strictures. The mean size of the lesion was 3.48 cm. In the intention-to-treat analysis, the sensibility and accuracy of EUS-FNA were superior than ERCP tissue sampling with biliary brush cytology and intraductal forceps biopsy (93.8%, 94% vs. 60.4%, 62%, respectively) (p=0.034), with similar adverse events. There was no concordance between the methods and combining both methods improved the sensitivity and accuracy for 97.9% and 98%, respectively. In the subtype analyses, the EUS-FNA was superior, with a higher accuracy than ERCP tissue sampling in evaluating extraductal lesions (100% vs. 54.8%, p=0.019) and in those larger than 1.5 cm (95.8% vs. 61.9%, p=0.031), but were similar in evaluating intraductal lesions and lesions smaller than 1.5 cm. There was no significant difference between the methods in the analyses of proximal, distal and pancreatic lesions. In the subtype analyses of the techniques employed, the brush cytology and the intraductal transpapillary biopsy presented similar results, as well as capillary and suction techniques. Conclusion: EUS-FNA is better than ERCP tissue sampling with biliary brush cytology and intraductal forceps biopsy with similar adverse events. There is no concordance between the methods and their association increases the accuracy. EUS-FNA is superior to ERCP tissue sampling in the assessment of extraductal lesions and in those larger than 1.5 cm and similar in the intraductal and in the lesions smaller than 1.5 cm. The brush cytology and intraductal transpapillary biopsy present similar results as well as capillary and suction techniques. There are no differences between methods in individual analyses of distal, proximal and pancreatic lesions

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [92]-106).

Thesis (doctoral)--Lund University, 1993. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1993. / Added t.p. with thesis statement inserted.

Introdução: A atresia biliar (AB) inclui obstrução completas das vias biliares extra-hepáticas e uma colangiopatia intra-hepática progressiva, cirrogênica. A natureza da colangiopatia destes processos permanece obscura. Uma arteriopatia levando a colangiopatia isquêmica explicaria a natureza progressiva da lesão biliar. A imunolocalização do fator de crescimento endotelial vascular A (VEGFA) em ramos arteriais e ductos biliares intra-hepáticos e do porta hepatis dos pacientes com AB sugere isquemia nestas estruturas. A ocorrência de hipóxia hepatobiliar na AB necessita ser esclarecida. Objetivo: Determinar a presença de hipóxia nos fígados de pacientes com AB, analisando a expressão gênica dos fatores induzidos por hipóxia (HIF) -1α e -2α. Métodos: Estudo de amostras de biópsias em cunha coletadas na laparotomia exploradora de pacientes com AB isolada sem IgM+ para citomegalovírus (n= 32) comparando com lactentes com colestase intra-hepática (CIH, n= 09), pareados por idade. Uma amostra foi ultracongelada (análise molecular) e outra, parafinizada (análises histológica e imunoistoquímica). Por PCRq, usando sondas TaqMan®, avaliaram-se as expressões gênicas de: HIF1-α, HIF2-α, proteína quimiotática de monócitos 1 (MCP1) (marcador de fibrose biliar), citoqueratina 19 (CK19) (marcador de colangiócitos). O gene normalizador foi 18S ribossômico. Por morfometria, foram quantificadas as extensões de fibrose e reação ductular. Dados clínico-laboratoriais foram prospectivamente coletados. Resultados: O grupo AB, comparado à CIH, apresentou maior expressão de HIF1-α e HIF2-α. No grupo AB, a expressão do HIF1-α correlacionou-se positivamente com a bilirrubina total (BT) sérica. Dois subgrupos de AB foram detectados quanto à expressão dos HIFs: alta (hiHIF, expressão 3x maior que a mediana da CIH) e baixa (loHIF). Pacientes hiHIF-1α eram mais velhos e com maiores níveis de BT e bilirrubina direta (BD) que loHIF-1α. O subgrupo hiHIF-2α apresentou expressão de CK19 inferior a do loHIF-2α. As demais variáveis foram semelhantes nos subgrupos HIFs. Conclusão: Na AB ocorre hipóxia tecidual hepática. Os dados sugerem a existência de hipóxia tecidual progressiva nos fígados afetados pela AB, associada ao desaparecimento de ductos biliares e à piora do quadro obstrutivo biliar. / Background: Biliary atresia (BA) includes a complete obstruction of the extrahepatic biliary tract and progressive intrahepatic cholangiopathy, and the nature of these processes remains unclear. An arteriopthy, leading to an ischemic cholangiopathy, can be involved. The immunolocalization of vascular endothelial growth factor A (VEGFA) in arterial branches and bile ducts both within the liver and at porta hepatis from patients with BA suggests ischemia in these structures. The occurrence of hypoxia in the hepatobiliary system in BA needs to be elucidated. Aim: To determinate the presence of hypoxia in the livers from patients with BA, by analyzing the gene expression of hypoxia-inducible factor (HIF) -1α and -2α. Methods: Liver biopsy specimens collected at exploratory laparotomy of age-matched patients with isolated, cytomegalovirus IgM-negative BA (n=32) and intrahepatic cholestasis (IHC, n=9) were evaluated. A sample was ultrafrozen (molecular analysis) and the other was paraffin-embedded (for histological and morphometric analyzes). Gene expression of: HIF-1α, HIF-2α, monocyte chemoattractant protein 1 (MCP1) (biliary fibrosis marker) and cytokeratin 19 (CK19) (cholangiocyte marker) were evaluated by PCRq using TaqMan® probes. The normalizing gene was 18S ribosomal. The extents of fibrosis and ductular reaction were assessed by morphometry. Clinical and laboratory data were prospectively collected. Results: There was higher HIF-1α and HIF-2α expression in BA in comparison with IHC. In BA, the HIF-1α expression was positively correlated with total serum bilirubin (TB). Two groups were observable in BA regarding HIFs: higher (hiHIF, considering as cutoff point a value higher than 3x the median of expression in IHC) and lower (loHIF). Patients with hiHIF-1α were older and presented increased levels of TB and direct-reacting serum bilirubin (DB) than loHIF-1α. Patients with hiHIF-2α presented CK19 expression lower than in loHIF-2α. The other variables were similar in subgroups HIFs. Conclusion: In BA there is hypoxia in the liver tissue, which seems to be progressive and associated with the disappearance of bile ducts and worsening biliary obstruction.

Made available in DSpace on 2014-06-11T19:27:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2002Bitstream added on 2014-06-13T19:35:15Z : No. of bitstreams: 1 eduardo_lhpr_me_botfm.pdf: 344254 bytes, checksum: e4b1f0a9ea2897a0ef33afa14dec935c (MD5) / Na colestase crônica experimental obstrutiva em ratos, ocorre diminuição progressiva do parênquima hepático e, consequentemente, prejuízo das funções hepáticas. A absorção da vitamina lipossolúvel A, depende da presença de ácidos biliares na luz intestinal e, assim, está prejudicada na colestase. A deficiência de vitamina A prejudica as defesas antioxidantes, facilitando as lesões hepáticas intermediadas por radicais livres. Além disso, a lesão do parênquima hepático prejudica a síntese de proteínas ligadoras de retinol (R.B.P.), sua liberação para o sangue e, em consequência, a liberação de V.A. das reservas hepáticas. Nosso objetivo foi testar se a administração de vitamina A hidromiscível interfere com os efeitos da colestase sobre a estrutura e a função do fígado. Para tanto, estudamos 1) níveis séricos da V.A.; 2) mortalidade espontânea num período de 49 dias de colestase; 3) mortalidade após administração de 0,5mg de pentobarbital/g de peso do animal por via intra-peritoneal no 48o dia de colestase; 4) intensidade da fibrose e inflamação hepáticas além da proliferação ductal em 134 ratos machos da raça Wistar desmamados aos 21 dias... / In experimental chronic obstructive cholestasis there is a progressive atrophy of the hepatic parenchima and, therefore, an impairment in hepatic function. Cholestasis is frequently associated with deficiency of the fat-soluble-vitamins A,D,E,K because the intraluminal solubilization and absorption of ingested lipids requires an adequate bile flow. The hepatic dammage secondary to biliary obstruction impairs the hepatic sinthesis and delivery of retinol binding protein (RBP). In consequence, there is an impairment in the delivery of V.A. from the hepatic stores and its supply to the target tissues. Its deficiency diminishes the antioxidative potential enhancing liver dammage mediated by oxygen free radicals. Our aim was to analyse the effects of two factors: 1) cholestasis and 2) the administration of an hidromiscible V.A. and their interaction using male 21 days old Wistar rats submited to double ligature and ressection of the common bile duct or sham-operated as regards 1) the serum levels of V.A., 2) espontaneous mortality; 3) mortality after pentobarbital; 3) intensity of hepatic fibrosis, inflamation and ductal proliferation... (Complete abstract click electronic address below)

This thesis is focused on the study of glycosphingolipids in the rat liver in different types of cholestasis and the effect of oxidative stress on changes in the composition and localization of gangliosides. First, it was necessary to optimize the immunochemical detection of glycosphingolipids. GM1 ganglioside was selected as a representative of a large glycolipid family. We found that minimum water content in the fixing solution was a key condition for fixation of histological sections. Optimized method of GM1 detection was subsequently used in in vivo experiments. We have demonstrated that estrogen-induced cholestasis characterized by high concentrations of bile acids and increased oxidative stress caused changes in the synthesis and distribution of liver gangliosides. HMOX induction is associated with a reduction in oxidative stress level and accompanied by normalization in GSL content. In experiments with obstructive cholestasis, we found that changes in the distribution and synthesis of gangliosides were not strictly specific to a particular type of cholestasis. We assume that it represents a general mechanism of hepatoprotection. We also confirmed the important role of bilirubin, product of HMOX reaction, in protection of hepatocytes against oxidative damage caused by high concentrations of...