OBJECTIVE. To identify clinical, socio-demographic, dietary and biological markers to be used in a non-invasive and cost-effective clinical tool for screening for non-alcoholic fatty liver disease (NAFLD) in obese adolescents. METHODS. We conducted a cross-sectional analysis using baseline data from 77 obese adolescents enrolled in a drug trial for the Glaser Pediatric Research Network, between October 2003 and August 2007. NAFLD was defined as the presence of fatty liver infiltration assessed by computed tomography. Receiver operation characteristic (ROC) analyses were performed to identify variables with the highest area under the curve (AUC) for NAFLD. Serum biomarkers were dichotomized using sensitivity analyses to identify the best cutoff point for NAFLD. Multiple logistic regression models were created to predict prevalent NAFLD. RESULTS. Serum triglycerides was identified as the best biomarker for NAFLD (AUC 0.790; pseudo R2 0.235). Additional adjustment for sex, age and Tanner stage improved the AUC to 0.846 and the pseudo R2 to 0.290. We then explored adding a simple biochemical marker for predicting NAFLD (HOMA-B, ALT or glutamate) and found that HOMA-B led to greater improvement in AUC, ALT to a greater improvement in sensitivity and glutamate to a greater improvement in the pseudo R2. Thus, all three factors individually improved overall model performance to some degree and inclusion of all three led to an AUC=0.907 and pseudo R2=0.433. Our second objective was to develop a more complex exploratory model starting with the inclusion of important clinical predictors (triglycerides, sex, age, Tanner stage, SBP, BMI, waist circumference); this yielded an AUC of 0.871 and pseudo R2 of 0.342. Further adjustment for HOMA-B, ALT and glutamate gave an AUC=0.913 and pseudo R2=0.497. CONCLUSION. Simple clinical and biochemical factors may be used to screen for prevalent NAFLD. Our simplest clinically relevant model using triglycerides, age, sex and Tanner stage provided a reasonable screening tool for NAFLD in obese adolescents. A second more complex model that warrants further testing includes triglycerides, sex, age, Tanner stage, SPB, BMI, waist circumference, HOMA-B, ALT and glutamate. In this study, this model was more accurate for detecting undiagnosed cases of NAFLD in this pediatric population.

The non-alcoholic fatty liver disease (NAFLD) is the most common liver pathology in developed countries with an estimated prevalence of 20 to 30% in the American population. A typically benign and asymptomatic pathology, NAFLD is characterized by hepatic steatosis and abnormal levels of hepatic enzymes stemming from an increase in circulating free fatty acids originating from white adipose tissue lipolysis, an increased de novo lipogenesis, reduced fatty acid oxidation and decreased hepatic triglycerides secretion, all within an insulin resistance context. NAFLD has the potential to progress to the non-alcoholic steatohepatitis (NASH), a condition marked by inflammation, advanced oxidative stress and fibrosis. NASH is expected to be the leading cause of liver transplant by 2020 due to its complications (i.e.: cirrhosis, hepatocellular carcinoma and liver failure). Various xenobiotics such as pesticides have been shown to promote the apparition and development of NAFLD. Of interest to this study is the neonicotinoid imidacloprid, more contemporarily known for its suspected role in the colony collapse disorder of various anthophilae species. Imidacloprid has been shown to induce hepatic oxidative stress in rats, a significant factor in the development of NAFLD and its progression to NASH. Lifestyle modifications, namely physical exercise, is a current treatment which has been proven beneficial to prevent and treat NAFLD by reducing hepatic steatosis, oxidative stress and improving insulin sensitivity. The role of any neonicotinoid on the development of NAFLD has yet to be examine and few have looked at the role of exercise in the treatment of NAFLD brought about by pesticide contamination.

p. 1-79 / Submitted by Antonio Geraldo Couto Barreto (ppgms@ufba.br) on 2013-10-02T17:02:51Z No. of bitstreams: 1 TESE_Consuêlo Padilha-1.pdf: 9442449 bytes, checksum: 72ab1d2cb912c235e58236ec944e7b16 (MD5) / Approved for entry into archive by Patricia Barroso (pbarroso@ufba.br) on 2013-10-30T19:36:47Z (GMT) No. of bitstreams: 1 TESE_Consuêlo Padilha-1.pdf: 9442449 bytes, checksum: 72ab1d2cb912c235e58236ec944e7b16 (MD5) / Made available in DSpace on 2013-10-30T19:36:47Z (GMT). No. of bitstreams: 1 TESE_Consuêlo Padilha-1.pdf: 9442449 bytes, checksum: 72ab1d2cb912c235e58236ec944e7b16 (MD5) Previous issue date: 2013 / A Doença Hepática Gordurosa Não Alcoólica (DHGNA) representa a causa mais comum de doença do fígado na atualidade. Está associada com síndrome metabólica e, mais recentemente, às doenças cardiovasculares. Objetivo: avaliar a associação entre DHGNA e doença arterial coronariana (DAC) e os fatores preditivos desta associação em indivíduos submetidos à cineangiocoronariografia (CAG). Metodologia: Foi realizado estudo transversal, que avaliou indivíduos submetidos à CAG com suspeita de DAC. Os pacientes realizaram avaliação clínico–laboratorial e ultrassonografia abdominal (USAB). Critérios para DAC: presença de lesão obstrutiva em artérias coronárias epicárdicas ou seus principais ramos. Critérios para DHGNA: presença de esteatose na USAB; ingestão alcoólica ≤20 g/dia; ausência de outras doenças hepáticas. As variáveis contínuas foram avaliadas pelos testes t de Student ou teste de Mann-Whitney e as categóricas pelo teste do qui-quadrado com nível de significância (p) < 0,05. Análise de regressão mediu a força da relação entre os fatores de risco e a presença concomitante de DAC e DHGNA. Resultados: Foram estudados 244 pacientes com média de idade de 61,5±9,3 anos. A DAC foi observada em 63,5%, e a DHGNA, em 42,2% dos pacientes. Aqueles com DAC eram, predominantemente, do gênero masculino (p<0,01); diabéticos (p<0,05) e tabagistas (p=0,045), e 43,9% deles tinham DHGNA. A DHGNA esteve associada à DM2, resistência insulínica, síndrome metabólica, obesidade central, índice de massa corpórea, triglicérides e alanina aminotransferase (p<0,05). A ocorrência concomitante de DAC e DHGNA foi positivamente correlacionada a sobrepeso/obesidade e HOMA-IR ≥3,0. Conclusões: A amostra teve elevada frequência de ambas, DAC e DHGNA; DHGNA foi mais elevada em pacientes com DAC, porém não houve associação estatisticamente significante entre as duas doenças; pacientes com associação DAC e DHGNA apresentavam sobrepeso/obesidade, e resistência insulínica. Os resultados sugerem a relevância clínica de investigar a DHGNA em pacientes com DAC, no sentido de diminuir a morbimortalidade desses pacientes. / Salvador

No description available.

A incidência da obesidade tomou proporções epidêmicas nos últimos anos, atingindo bilhões de indivíduos mundialmente. A DHGNA é uma manifestação hepática das alterações metabólicas causadas pela obesidade e os casos desta doença vêm crescendo cada vez mais. Alternativas capazes de reduzir estas alterações são fundamentais para minimizar o impacto na qualidade de vida da população e na economia do país. Diversos estudos têm mostrado que os compostos bioativos de alimentos possuem efeitos benéficos à saúde. O camu-camu (Myrciaria dubia (H. B. K). Mc Vaugh) é um fruto nativo da região amazônica com potencial agroeconômico ainda inexplorado, que contém um grande número de compostos fitoquímicos que podem atuar sobre o metabolismo corporal. Desta forma, o objetivo deste estudo foi avaliar o efeito dos compostos fenólicos do camu-camu no desenvolvimento da DHGNA em camundongos C57BL/6 que receberam dieta rica em lipídios e sacarose (HFS). O extrato rico em compostos fenólicos da polpa comercial deste fruto foi obtido através de extração em fase sólida e caracterizado por cromatografia líquida de alta eficiência (CLAE/DAD). Os extratos obtidos foram testados em doses de 7 mg e de 14 mg equivalentes de ácido gálico/Kg de peso corporal. Foram investigados os efeitos destes compostos sobre as homeostases glicídica e lipídica através de análises séricas, testes de tolerância à insulina e à glicose e conteúdo de glicogênio e triacilglicerol intra-hepático. O extrato do camu-camu apresentou flavonóis, ácido elágico e elagitaninos em sua composição. A suplementação com extrato fenólico de camu-camu diminuiu a intolerância à glicose, independente da dose administrada, e melhorou a sensibilidade à insulina e regulou o conteúdo de glicogênio intra-hepático na maior dose. Não foi observado efeito sobre os lipídios plasmáticos. Entretanto, nota-se que houve uma melhora na função hepática em decorrência da redução da atividade da alanina aminotransferase (ALT), indicadora de dano celular, independente da dose. Além disso, a suplementação com extratos fenólicos do camu-camu na maior dose reduziu o conteúdo de triacilglicerol intra-hepático (p = 0,0001) e de biomarcadores inflamatórios, como Proteína - C Reativa (PCR) (p = 0,0359) e prostaglandina E2 (PGE2) (p = 0,004). Estes efeitos foram associados, principalmente, à menor ingestão alimentar. Portanto, neste estudo, os compostos fenólicos do camu-camu foram eficientes em prevenir a progressão da DHGNA em camundongos alimentados com dieta HFS. / Obesity has reached epidemic proportions in recent years, affecting billions of people worldwide. Nonalcoholic fatty liver disease (NAFLD) is a hepatic disorder induced by the metabolic changes caused by obesity and its incidence has been growing increasingly. Alternatives designed to reduce such changes are crucial to minimize their impact on the population´s quality of life and countries economy. Several studies have shown that food bioactive compounds have beneficial effects on health. Camu-camu (Myrciaria dubia (H. B. K.) Mc Vaugh) is a native fruit from Amazonan, with unexplored agroeconomic potential, which contains a large number of phytochemical compounds that can act on body metabolism. Therefore, this study was designed to assess the effect of the phenolic compounds of camu-camu in the development of NAFLD in C57BL/6 mice fed with a lipid and saccharose-rich diet (HFS). The phenolic compound-rich extract was obtained from the commercial pulp of this fruit using solid-phase extraction and high-performance liquid chromatography with diode array detector (HPLC/DAD). The resulting extracts were tested at 7 mg and 14 mg gallic acid equivalents/kg body weight. The effects of these compounds on glucose and lipid homeostasis were investigated by serum analyses, insulin and glucose tolerance tests and intrahepatic content of glycogen and triacylglycerol. Camu-camu extract presented flavonols, ellagic acid and ellagitannins in its composition. Supplementation with camu-camu phenolic extract decreased glucose intolerance, regardless the dose, improved insulin sensitivity and normalized the intra-hepatic glycogen content at the highest dose. No effects on plasma lipid were found. However, an improvement in liver function due to the decrease in alanine aminotransferase (ALT) was observed, suggestive of cell damage, regardless the dose. Moreover, the supplementation with phenolic extracts of camu-camu at the highest dose decreased the intrahepatic content of triacylglycerol (p = 0.0001) and inflammatory biomarkers, such as C-reactive protein (CRP) (p = 0.0359) and prostaglandin E2 (PGE2) (p = 0.004). Such effects were primarily associated with lower food intake. Therefore, in this study, the phenolic compounds of camu-camu have shown to be effective in preventing the progression of NAFLD in mice fed with HFS (high-fat/sucrose) diet.

<div><div><div><p>Transcriptomic regulation of human liver is a tightly controlled and highly dynamic process. Genetic and environmental exposures to this process play pivotal roles in the development of multiple liver disorders. Despite accumulating knowledge have gained through large-scale genomics studies in the developed adult livers, the contributing factors to the interindividual variability in the pediatric livers remain largely uninvestigated. In the first two chapters of the present study, we addressed this question through an integrative analysis of both genetic variations and transcriptome-wide RNA expression profiles in a pediatric human liver cohort with different developmental stages ranging from embryonic to adulthood. Our systematic analysis revealed a transcriptome-wide transition from stem-cell-like to liver-specific profiles during the course of human liver development. Moreover, for the first time, we observed different genetic control of hepatic gene expression in different developmental stages. Motivated by the critical roles of genetics variations and development in regulating hepatic gene expression, we constructed robust predictive models to impute the virtual liver gene expression using easily available genotype and demographic information. Our model is promising in improving both PK/PD modeling and disease diagnosis for pediatric patients. In the last two chapters of the study, we analyzed the genomics data in a more liver disease- related context. Specifically, in the third chapter, we identified Macrophage migration inhibitory factor (MIF) and its related pathways as potential targets underlying human liver fibrosis through an integrative omics analysis. In the last chapter, utilizing the largest-to-date publicly available GWAS summary data, we dissected the causal relationships among three important and clinically related metabolic diseases: non-alcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D), and obesity. Our analysis suggested new subtypes and provided insights into the precision treatment or prevention for the three complex diseases. Taken together, through integrative analysis of multiple levels of genomics information, we improved the current understanding of human liver development, the pathogenesis of liver disorders, and provided implications to precision medicine.</p></div></div></div>

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<p>This research was conducted to develop and evaluate a screening tool for Hepatic Steatosis (or fatty liver) detection using machine learning based models. The developed models are intended to be used as a potential clinical decision support tool for identifying patients with Non-Alcoholic Fatty  Liver  Disease  (NAFLD).  Two  versions  of  a  HS  prediction  tool  are  discussed  in  Paper  1, Objectives 1A, and 1B, respectively.</p> <p>Explainability  analysis  of  the  developed  models  is  also  a  major  component  of  this  work, discussed in Paper 2. Models from Paper 1 are analyzed further for interpretability and the results are then compared with current clinical literature. Insights from the explainability analysis are used to  identify  best  models  that  follow  the  clinical  literature  logically.  Most  contributing  features within each model are also identified in this work.</p> <p>Another aspect of NAFLD management is related to the chronic exposure to heavy metals in the environment (such as: Arsenic, Lead, Cadmium etc.). The heavy metal exposure component is explored in two ways in this dissertation. In paper 3, another version of the ML-based screening tool is explored by including heavy metal exposure data. The results from the model (with heavy metal data) are then compared with models that exclude the heavy metal exposure data. The results and their implications are discussed in paper 3.</p> <p>Arsenic is a major hepatotoxin and the chronic exposure can lead to severe liver injury. In Paper  4,  a  commercially  available  Arsenic  detection  kit  was examined  for  Arsenic  detection  in water  at  a  household  level.  The  kit  was  evaluated  following  a  short  experimental  plan  and  the obtained  results  are  discussed.  Finally,  the  obtained  images  were  quantified  digitally  using  a customized image analysis and pattern recognition algorithm. The methods used for quantification and the obtained results are also discussed.</p> <p><br></p>

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1 Abstract In this thesis I have focused on the role of lipids in the pathogenesis of liver diseases, specifically on cholestasis and non-alcoholic fatty liver disease (NAFLD). The first major aim was to clarify the changes in liver ganglioside metabolism in various types of cholestasis and to elucidate the role of heme oxygenase-1 (HMOX1) and associated oxidative stress. The second objective was to determine the effects of n-3 polyunsaturated fatty acids (n-3 PUFA) administration on NAFLD development in a rodent dietary model of NAFLD and in patients with metabolic syndrome and NAFLD. Our results suggest that increased ganglioside biosynthesis and their re-distribution might represent a general protective mechanism of hepatocytes under cholestatic conditions (both estrogen-induced and obstructive aetiology). These changes are closely related to oxidative stress and might protect hepatocytes against deleterious effect of accumulated bile acids. The lack of HMOX1 activity and subsequent oxidative stress potentiate pathological changes in the liver and resulted in tissue-specific modulation of synthesis and re-distribution of gangliosides (in vivo and in vitro). Contrary to it, HMOX1 activation has an opposite effect and may represent a general hepatoprotective mechanism. We have proven that observed changes...