Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 120-141). Also available in print.

published_or_final_version / Medicine / Master / Master of Philosophy

Non-alcoholic fatty liver disease (NAFLD) includes simple hepatic steatosis (SS) and non-alcoholic steatohepatitis (NASH). NAFLD is tightly linked to obesity and is thought to be secondary to various noxious signals, some of which may originate from the intestinal microbiota (IM). Despite a growing body of evidence supporting a link between obesity and altered IM, there are no studies assessing the IM of patients with NAFLD. In this cross-sectional study we aimed at comparing fecal levels of total bacteria, Bacteroidetes, C. coccoides, C. leptum, Bifidobacteria, E. coli, and Archaea between healthy controls (HC) and patients with SS or NASH. We found higher C. coccoides levels in NASH compared to SS and lower percentage Bacteroidetes in NASH compared to SS and HC. Controlling for body mass index and fat intake we found an association between presence of NASH and percentage Bacteroidetes. The latter inversely correlated with insulin resistance.

Thesis (M. Res.(Med.))--University of Hong Kong, 2007.

Inaug.-Diss.--Zürich. / Vita. Bibliography: p. 16-17.

BACKGROUND: As the prevalence of metabolic risk factors in the American population has increased over time, so too has the diagnoses of non-alcoholic fatty liver disease (NAFLD). Within this spectrum of disease lies the potential for silent progression towards cirrhosis, leaving the patient with few options for treatment. Currently, the standard of care remains counseling on diet and exercise with the goal of reversing disease progression by addressing the underlying risk factors. LITERATURE REVIEW: Recent studies have shown that a correlation exists between low levels of serum 25-hydroxyvitamin D and hepatic injury from NAFLD. This has become an active area of research, due in part to the anti-inflammatory and immunoregulatory properties of vitamin D. The prospect of a simple and cost effective intervention that can exert its effects on the mechanisms behind the development of NAFLD is interesting and warrants further research. PROPOSED PROJECT: This proposal is for a double-blind, randomized, experimental study of vitamin D3 (cholecalciferol) versus placebo in a patient population of those with both clinically proven NAFLD and concomitant vitamin D deficiency. Liver fibrosis will be measured and staged with the use of FibroScan elastography. The statistical analysis thereafter will determine if a clinically significant reduction in hepatic fibrosis exists, compared with the results of the placebo group. CONCLUSIONS/SIGNIFICANCE: Should vitamin D prove to be an effective treatment option in reversing the progression of NAFLD, clinicians would be equipped with a simple and safe tool to augment their management of the patient. For those that experience barriers (i.e. lower socioeconomic status, other comorbidities, etc.) preventing them from improving diet and exercise, vitamin D would serve as an alternative therapy to aid in reducing their disease burden. Easier methods to treat their disease now projects improved quality of life years later.

Orientador: Cecilia Amelia Fazzio Escanhoela / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T22:27:25Z (GMT). No. of bitstreams: 1 Silva_GustavoHenriqueda_D.pdf: 4225256 bytes, checksum: 6254dc5eb8ce2f1f9c9ac0ffbce99d41 (MD5) Previous issue date: 2009 / Resumo: A esteatose hepática não relacionada ao alcoolismo pode ocorrer isoladamente ou fazer parte da doença hepática gordurosa não alcoólica (DGHNA). Esta abrange um amplo espectro de alterações morfológicas, variando desde a esteatose até um estágio mais grave, acompanhado por fibrose, podendo chegar à cirrose. O objetivo do nosso estudo foi avaliar e caracterizar a esteatose de causa não definida na infância, por meio de análise morfológica e morfométrica do tecido hepático. Dezoito biópsias provenientes de 16 pacientes com idade variando de 3 meses a 12 anos e 9 meses, com vaga dor abdominal e/ou mínima hepatomegalia associada a aumento discreto e persistente das enzimas hepáticas, foram analisadas através de microscopia de luz e eletrônica de transmissão. Nestes detectou-se esteatose macro e microvesicular "pura", ou seja, não acompanhada de fibrose ou de quaisquer outras alterações histológicas. Na microscopia de luz foi realizada a determinação semi-quantitativa da intensidade da esteatose total (macro e microvesicular), com classificação de 1 a 4 e a estimativa da porcentagem de hepatócitos afetados pela esteatose microvesicular em relação aos hepatócitos afetados pela macrovesicular; na microscopia eletrônica calculou-se a densidade mitocondrial por hepatócito e a área mitocondrial média utilizado-se em ambos os casos o programa TPS Dig versão 1.30. Dez pacientes com 1 a 14 anos de idade e com diagnóstico de normalidade em biópsia hepática foram utilizados como grupo controle. Os resultados obtidos mostraram predomínio de esteatose microvesicular entre os pacientes estudados (61%), com elevação significativa da área mitocondrial, sendo 1,52 ± 0,08 µm2 a área média para o grupo controle, 1,49 ± 0,07 µm2 para o grupo de esteatose macrovesicular e 2,92 ± 0,36 µm2 para o grupo de esteatose microvesicular. Não foram observadas alterações significativas na densidade mitocondrial, seja relacionada à esteatose microvesicular predominante ou à macrovesicular (72 ± 2 mitocôndrias/hepatócitos para o grupo controle, 70 ± 11 mitocôndrias/hepatócitos para o grupo de esteatose macrovesicular e 66 ± 8 mitocôndrias/hepatócitos para o grupo de esteatose microvesicular). Tampouco se observou correlação entre as variações dos valores das transaminases com ambos os tipos de esteatose, uma vez que para o grupo de esteatose microvesicular os valores médios foram AST = 62.9 ± 35.0, ALT = 125.9 ± 129.0 e GGT = 210.5 ± 278.3 e para o grupo de esteatose macrovesicular AST = 82.1 ± 97.5, ALT = 57.4 ± 41.4 e GGT = 185.8 ± 141.7. No grupo de estudo, a esteatose "pura", com pouca ou nenhuma sintomatologia clínica, associada ou não a alterações de transaminases, não relacionada à obesidade ou doença metabólica conhecida, mostrou-se predominantemente microvesicular e relacionada a aumento do volume mitocondrial. Nas hepatopatias mitocondriais primárias (HMP), principalmente por defeitos na cadeia respiratória, este tipo de alteração é comum. Devido a estas alterações mitocondriais, esta esteatose não deve ser denominada "pura" podendo, inclusive, corresponder à porção mais distal no longo espectro da DGHNA. Destacamos que, apesar da pouca manifestação clínica e laboratorial destas crianças, é fundamental o acompanhamento sistemático destas, havendo necessidade de maior atenção aos casos de esteatose na infância com predomínio da forma microvesicular. / Abstract: Hepatic steatosis unrelated to alcoholism may occur separately or be part of fatty liver disease (NAFLD). It encompasses a wide spectrum of morphologic alterations, ranging from steatosis to a more severe stage accompanied by fibrosis and cirrhosis. The aim of our study was to assess and characterize childhood steatosis of not defined cause carrying out morphologic and morphometric analysis of liver tissue. Eighteen biopsies from 16 patients with age varying from 3 months to 10 years, with vague abdominal pain and/or minimal hepatomegaly associated with slight and persistent increase in hepatic enzymes had been analyzed through light microscopy and transmission electron microscopy. On those patients, "pure" steatosis was detected, meaning it was not followed of fibrose or any other significant histological alterations. In light microscopy total steatosis was semi-quantified with estimative of macro- and microvesicular steatosis percentage and determination of predominant steatosis, classified from 1 to 4 and estimate the percentage of hepatocytes affected by steatosis microvesicular in comparison to hepatocytes affected by macrovesicular; in electron microscopy it was determined the degree of mitochondrial density in the hepatocytes and mean mitochondrial surface area using in both cases the TPS Dig version 1.30. Ten patients between 1 and 14 years old who had a normal diagnosis on liver biopsy were used as a control group. The results had shown microvesicular predominance of steatosis in the studied patients (61%) with significant increase of mitochondrial surface area values: 1,52 ± 0,08 µm2 in the control group, 1,49 ± 0,07 µm2 in the macrovesicular steatosis group and 2,92 ± 0,36 µm2 in the microvesicular steatosis group. Significant alterations in mitochondrial density were not observed, neither related to predominant micro nor macrovesicular steatosis (72 ± 2 mitochondrias/hepatocytes in the control group, 70 ± 11 mitochondrias/hepatocytes in the macrovesicular steatosis group and 66 ± 8 mitochondrias/hepatocytes in the microvesicular steatosis group). A correlation between variations in transaminases levels and both types of steatosis was also not observed, since for the microvesicular steatosis group the average values was AST = 62.9 ± 35.0, ALT = 125.9 ± 129.0 and GGT = 210.5 ± 278.3 and for the macrovesicular steatosis AST = 82.1 ± 97.5, ALT = 57.4 ± 41.4 e GGT = 185.8 ± 141.7. In our study group, "pure" steatosis, with little or no clinical symptoms, associate or not to alterations of transaminases and that did not correlate with obesity or known metabolic diseases is predominantly microvesicular and was related to increased mitochondrial volume. In the primary mitochondrial hepatopathies (PMH), especially for respiratory chain defects, this alteration is common. Due to these probable mitochondrial alterations, this steatosis doesn't have to be called "pure", being able, also, to correspond to the portion distal in the long specter of the NAFLD. It is important to emphasize that although the small number of clinical and laboratorial manifestations of these children, it is essential their systematic accompaniment. There is necessity of more attention to the cases with steatosis in pediatric group where microvesicular form predominance occurs. / Doutorado / Ciencias Biomedicas / Doutor em Ciências Médicas

Obesity is increasing worldwide. The addition of excess calorie intake and unhealthy human behavior leads to also other diseases such as metabolic syndromes and liver disease such as non-alcoholic fatty liver disease. Furthermore, the accumulation of fat triggers specific mechanisms that, if prolonged, can cause tissue damage. For instance, the innate immune system becomes agitated in patients with NAFLD or obesity due to excessive fat accumulation. This leads to inflammation in specific tissues and infiltration of other immune cells. One of the main immune cells are neutrophils, which secrete a protease enzyme called protease neutrophil elastase. Interestingly, there have been studies conducted that have shown that when neutrophil elastase is knocked out in mouse models that mimic NAFLD, there seems to be a protective effect occurring in the body and lessen tissue scarring. A possible explanation, and the aim of this thesis, is to explore if autophagy is regulated and thus plays a role in protecting liver from inflammation and fibrosis. Western blotting approach was used to test this hypothesis. The protein samples that are used are extracted from neutrophil elastase knockout mice that have been fed a high-fat high-fructose diet and compare them to samples from wild-type control mice that have been fed a normal chow diet, high-fat diet, and high fat high fructose diet. The results indicated that potential upregulation of the autophagy pathway in the liver of neutrophil elastase knockout mice and more studies would need before accurately and reliably acknowledging the alternation of the autophagy pathway in the liver from mouse model of NAFLD and when neutrophil elastase is knocked out. / 2023-12-10T00:00:00Z

archives@tulane.edu / Alcoholic and nonalcoholic fatty liver disease is projected to be the most common cause of liver disease in developing countries. The main significant risk factors are obesity, diabetes mellitus type 2, cardiovascular disease, and dyslipidemia. Louisiana is ranked seventh in liver cancer diagnoses and ranked sixth in the leading cause of death. Recent findings indicated that multifaceted stress response due to the accumulation of fatty acids from the diet is the driving force of disease progression. We sought to study multifaceted integrated stress response (ISR) in liver cells cultured with saturated fatty acids. Understanding the process that ISR takes to either induce or inhibit autophagy, self-eating machinery, in strongly permissive HUH 7.5 cells is vital when treating liver abnormalities. The major protein kinase, P-EIF2 alpha, was the targeted factor contributing the most to autophagy due to its functional link to the endoplasmic reticulum, mitochondria, and cellular membrane by further assessment using the inductive drug, Sephin 1. HUH, 7.5 liver cells are treated with increasing amounts of palmitic acid for 24 hours in DMEM with 10% FBS. ISR activated after substantial cellular damage leading to autophagy impairment. The cell culture was assessed for lipid accumulation, and the expression of PKR, IRE1 alpha, PERK, ATF6, P-EIF2 alpha, HRI, MTORC1, GCN2, P62, and LC3B was achieved by immunoblot analysis. Membrane fluidity PKR, lysosomal MTORC1, and protein synthesis GCN2 activated to elicit an integral response to the ISR pathway. Endoplasmic reticulum protein kinases induced in response to UPR activation lead to an integration of the P-EIF2 alpha pathway. Mitochondrial stress heme regulated inhibitor proliferated to provoke an activation in the significant protein kinase leading to autophagy impairment. The P-EIF2 alpha kinase invoked autophagic deficiency even when dephosphorylation was prevented by Sephin 1 drug treatment. ISR constrained autophagy in the liver-derived cell line due to the accumulation of the toxic saturated fatty acid. Keywords: palmitate, autophagy, fatty liver disease, integrated stress response, Sephin 1 / 1 / Glory Ogunyinka

Student Number : 0101826W - M Med dissertation - School of Clinical Medicine - Faculty of Health Sciences / Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease with hepatic histology that resembles alcoholic liver disease. It is a frequent cause of chronic liver disease and is attracting increasing scientific attention worldwide. I explored the possibility that increased gastrointestinal alcohol production may have a role as a “second hit” in the pathogenesis of NAFLD in study subjects with the metabolic syndrome. In an attempt to investigate this hypothesis, this study looked at blood, urine and breath levels of alcohol in patients with the metabolic syndrome versus matched age and ethnic group healthy controls. Of the twenty study subjects, 80% had dyslipidaemia, 60% had hypertension and 70% had type 2 diabetes mellitus. Their mean BMI was 35.1±8.2 kg/m² (mean ± SD, P < 0.0001 versus controls). The serum aminotransferases were significantly elevated in the study subjects, their ALT levels being 57.4±44.79 U/L versus 17.4±4.60 U/L in the controls (95% CI 18.02 – 61.42, P < 0.001), and their AST levels 52.5±36.21 U/L versus 23.4±4.86 U/L in the controls (95% CI 11.99 – 46.20, P < 0.01). Seventy five percent of the study group had sonar features suggestive of fatty liver disease. Two adipocytokines, adiponectin and leptin, mediators of insulin resistance, an important factor in the development and progression of NAFLD, were also measured. Adiponectin levels were significantly lower (6875 ng/L versus 15475 ng/L; median value, P < 0.01), and leptin concentration levels significantly higher (13.56 ng/L versus 3.05 ng/L; median value, P < 0.05) in the study subjects than in the control group. Alcohol was detected in 60% of the study subjects, of which 35% tested positive for ethanol, 55% tested positive for methanol, and 30% tested positive for both ethanol and methanol. This was a statistically significant result, as none of the control group tested positive for any of the alcohols. The ethanol concentration in the study subjects’ blood was 7.14±3.28 mg% (mean ± SD), in their urine 3.71± 12.87 mg% (mean ± SD) whilst none was detected in their breath. The methanol concentration in the study subjects’ blood was 16.17±17.95 mg% (mean ± SD), in their urine 6.8± 13.58 mg% (mean ± SD) while their breath level was 2.05±3.19 mg (mean ± SD). This study therefore suggests that endogenous alcohol production may be indeed be involved in the pathogenesis of NAFLD in subjects with the metabolic syndrome. Not only ethanol but also methanol was detected in the subjects tested. Endogenous alcohol may therefore be responsible for the ‘second hit’ theory in the pathogenesis of NAFLD, and it is likely that formaldehyde, the metabolite of methanol may be a more potent toxin of hepatocyte injury as opposed to acetaldehyde, the metabolite of ethanol. The most likely source of the alcohol is from intestinal bacterial flora. These findings provide further insight into the pathogenesis of NALFD, suggesting other therapeutic alternatives such as the use of antibiotics and probiotics as a potential treatment strategy for NAFLD.