Source: Dissertation Abstracts International, Volume: 69-10, Section: B, page: 6009. Adviser: Dorothy K. Waller. Includes bibliographical references.

Background: The sensitivity to drug-induced QT prolongation is highly variable in heart failure (HF) patients. QT interval prolongation can lead to a life-threatening ventricular arrhythmia known as torsade de Pointes (TdP), which can result in sudden cardiac death. Although QT prolongation is a surrogate marker for sudden cardiac death, the extent of drug-induced QT prolongation, and thus TdP, is largely unpredictable. Therefore, developing a biomarker to predict patients’ sensitivity to drug-induced QTc prolongation could have a profound clinical impact. MicroRNA (miR) are recognized as important regulators of cardiovascular function as they shape the transcriptome by targeting mRNAs for repression of translation. Our multidisciplinary research group has demonstrated that miR-362-3p regulates a potassium channel (i.e., hERG) that is the most widely implicated in drug-induced QTc prolongation. The primary objects of this analysis focus on characterizing serum miR-362-3p expression in the circulation as a potential biomarker to predict subject’s susceptibility to ibutilide exposure induced QT-interval prolongation.<div><br></div><div>Methods: The dataset utilized to develop the PK-PD models were collected from a previous clinical study carried out by Tisdale et al. (Tisdale,et al. 2020).A total of 22 adult subjects who met the inclusion and exclusion criteria were enrolled and divided into three groups: a group of patients with heart failure with preserved ejection fraction (HFpEF, n=10), a group of patients with heart failure with reduced ejection fraction (HFrEF, n=2), and ten healthy subjects in the control group who were matched to subjects in the HFpEF group for age and sex. Following a baseline day of triplicate 12-lead ECGs, all subjects received ibutilide 0.003mg/kg intravenously infused over 10 minutes. Serial collection of blood samples to determine serum Ibutilide concentrations (HPLC/MS), serum miR-362-3 expression (qPCR), with triplicate ECG readings were obtained pre-and-post ibutilide administration. To describe ibutilide serum concentration exposure and the9relationship with Fridericia-corrected QT (QTF) intervals, a non-linear mixed effect modeling approach was used along with clinical and demographic data, and serum miR-362-3p expression was evaluated as potential covariates on the PK/PD model.<div><br></div><div>Results: A three-compartment model best described the time course of ibutilide concentrations profile with a proportional residual error. The individual ibutilide concentrations time profile was then used in an indirect response model where ibutilide concentrations are indirectly driving the QT interval prolongation through inhibition of the output (Kout) parameters linked to an indirect response model with zero‐order input parameter best described the ibutilide concentrations QT interval lengthening relationship. The Individual PK/PD parameters using the base model for the Imax and IC50 were 11.4% (9.9%RES) and 0.36(8.4% RES)ng/mL, respectively. Following stepwise forwarding inclusion steps, the final covariate analyses identified circulating miR-362-3p expression associated with a history of myocardial infarction covariate influencing both the Imax and IC50( p<0.05). <div><br></div><div>Conclusions: An indirect response model has been developed to describe the effects of ibutilide concentrations on QT-intervals. Although the semi-mechanistic model could not be developed; serummiR-362-3p expression was identified as a significant predictor for ibutilide-induced QT-interval prolongation. Moreover, the upregulation of serum miR-362-3p expression enhanced IC50 seen after ibutilide administration. The potential use of miR-362-3p as a biomarker warrants further investigation to identify patients at the greatest risk of TdP </div></div></div>

Abstract Various genetic aetiologies — including mitochondrial diseases, chromosomal disorders, and other monogenic diseases — are involved in status epilepticus (SE), a common neurologic emergency occurring in children and adults that exhibits high rates of morbidity and mortality. The exact frequency of mitochondrial SE is currently undefined. Furthermore, patients with pathogenic variants of POLG1 encoding mitochondrial DNA polymerase gamma have an increased risk of acute liver failure (ALF) induced by the common antiepileptic drug, valproic acid (VPA), which is problematic due to these patients also often experiencing drug-resistant seizures. Overall, the role of liver transplantation (LT) in VPA-ALF due to mitochondrial disease has been controversial. In the present work, large retrospective cohort studies were conducted for two main purposes: (1) to determine the genetic aetiologies of SE among Finnish paediatric and adult patients by specifically focusing on the common mitochondrial genetic defects associated with an increased risk of SE and (2) to examine whether common POLG1 p.Q1236H and p.E1143G variants are connected to liver or pancreatic toxicity upon exposure to VPA monotherapy. This thesis also describes the characteristics of VPA-ALF associated with the pathogenic POLG1 variant p.W748S and the prognosis of LT in a retrospective case series. Mitochondrial diseases explained 4.5% of SE cases in the study cohort. Patients with mitochondrial SE suffered from refractory SE significantly more often than patients with other forms of genetic or non-genetic SE. Additionally, mortality rates were higher in patients with mitochondrial or chromosomal disorders compared with the other groups, reflecting the severity of the underlying condition and the higher frequency of refractory SE. POLG1 variants p.Q1236H and p.E1143G could not be identified as risk factors for VHT or pancreatic toxicity, implying that VPA treatment might be suitable for patients harbouring these variants when other pathogenic variants are absent. Finally, the homozygous status of the pathogenic POLG1 variant p.W748S and older age of the patient during the presentation of VPA-ALF seem to be associated with higher survival rates following LT, which should be considered in the management of VPA-ALF. / Tiivistelmä Useita perinnöllisiä syitä, kuten mitokondriotauteja, kromosomihäiriöitä ja muita geenimuutoksia on tunnistettu status epilepticuksen (SE) eli pitkittyneen epileptisen kohtauksen taustalla. SE on yleinen neurologinen hätätilanne, johon liittyy merkittävää oheissairastavuutta ja kuolleisuutta sekä lapsilla että aikuisilla. Mitokondriotauteihin liittyvän SE:n tarkkaa esiintyvyyttä ei tiedetä. Potilailla, joilla on patogeenisia variantteja mitokondrioiden DNA-polymeraasia koodaavassa tuman POLG1-geenissä, on todettu kohonnut riski yleisesti käytetyn epilepsialääkkeen valproaatin (VPA) aiheuttaman akuutin maksavaurion kehittymiselle. Tämä tekee lääkehoidon valinnasta ongelmallista, koska näillä potilailla on usein epilepsialääkkeille resistenttejä kohtauksia. Maksansiirron merkitys akuutin maksavaurion hoidossa mitokondriotauteja sairastavilla potilailla on ollut kiistanalainen. Tutkimuksen tavoitteena oli selvittää SE:n perinnöllisiä syitä suomalaisilla lapsi- ja aikuispotilailla retrospektiivisesti kerätyssä laajassa potilasaineistossa. Tutkimuksessa keskityttiin yleisimpiin mitokondriaalisiin perinnöllisiin muutoksiin, joiden on aiemmin todettu liittyvän SE:n lisääntyneeseen riskiin. Tutkimuksen toisena päätavoitteena oli selvittää väestössä yleisten POLG1-geenin muutosten eli varianttien p.Q1236H ja p.E1143G yhteyttä maksatoksisuuteen tai haimatoksisuuteen VPA-monoterapian aikana. Lisäksi tutkittiin VPA:n aiheuttaman maksavaurion kliinisiä erityispiirteitä patogeeniseen POLG1-varianttiin p.W748S liittyen sekä mutaatiostatuksen vaikutusta maksansiirron jälkeiseen ennusteeseen. Mitokondriotaudit selittivät 4,5 % SE-tapauksista tämän väitöskirjatyön potilasaineistossa ja näillä potilailla SE pitkittyi hoitoresistentiksi tai erittäin resistentiksi merkitsevästi muita potilasryhmiä useammin. Kuolleisuus oli suurin potilailla, joilla todettiin mitokondriotauti tai kromosomihäiriö, liittyen todennäköisimmin vakavaan taustasairauteen ja hoitoresistentin SE:n suurempaan esiintyvyyteen. Tutkittuja POLG1-variantteja p.Q1236H ja p.E1143G ei voitu tunnistaa maksa- tai haimatoksisuuden riskitekijöiksi, mikä tarkoittaa, että VPA-hoito voisi sopia näille potilaille, mikäli muita patogeenisiä variantteja ei todeta. Patogeenisen POLG1-variantin p.W748S homotsygoottisuus ja nuoruusikä tai varhainen aikuisikä maksavaurion ajankohtana ovat maksansiirron ennustetta parantavia tekijöitä, mikä tulisi ottaa huomioon hoitopäätöksiä tehtäessä.

OBJECTIVE: To review the evidence surrounding a potential association between liraglutide and pancreatitis. DATA SOURCES: A literature search was conducted in MEDLINE (1948-July 12, 2012) and EMBASE (1974-week 27, 2012) using the search terms pancreatitis, liraglutide, and glucagon-like peptide 1/adverse effects. Reference citations from identified publications were reviewed. The manufacturer was contacted and regulatory documents from the Food and Drug Administration website were reviewed for unpublished data related to cases of pancreatitis associated with liraglutide use. STUDY SELECTION AND DATA EXTRACTION: All identified sources that were published in English were considered for inclusion. DATA SYNTHESIS: Eleven cases of pancreatitis have been reported in patients taking liraglutide. Seven were from the LEAD (Liraglutide Effect and Action in Diabetes) studies, 1 was reported in the extension of a clinical trial, and 1 was in an unpublished obesity trial. Two were published postmarketing case reports. Nine of the cases reported were diagnosed as acute pancreatitis, while 2 were classified as chronic pancreatitis. The mean age of the patients was 57.5 years and mean body mass index was 33.92 kg/m2. Six of the 11 cases occurred in male patients. Nine of the patients were white and 1 was African American. In 7 of the cases, onset occurred at liraglutide doses at or above 1.8 mg daily. Common comorbidities included history of pancreatitis, cholelithiasis, and diabetes. One case was fatal. CONCLUSIONS: Pancreatitis is a potential complication with liraglutide therapy. Liraglutide should be used cautiously in patients at risk of pancreatitis (eg, alcohol abuse, history of pancreatitis, cholelithiasis).

No description available.

Minimizing anti-cancer drug toxicity is a major challenge for the pharmaceutical industry. Toxicity is most frequently due to either the direct interaction of the drug on previously unidentified targets or its conversion to metabolites by drug metabolizing enzymes (e.g. CYP450 enzymes) that cause cellular, tissue or organ damage. Pharmacoproteomics is beginning to take a central role in studying changes in protein expression corresponding to drug administration, the results of which, inform about the mode of action, toxicity, and resistance in pre-clinical and clinical stages of drug development. The main aim of this research is to apply comparative proteomics studies on livers from male and female mice xenograft models treated with major anti-cancer drugs (5-flourouracil, paclitaxel, cisplatin, and doxorubicin) and CYP inducer, TCPOBOP, to investigate their effect on protein expression profiles (proteome). Within this thesis, an attention is paid to optimise a highly validated proteomics workflow for biomarker identification. Proteins were extracted from liver microsomes of mice treated in two separate sets; Set A – male (5-fluoruracil, doxorubicin, cisplatin and untreated) or Set B – female (5-fluoruracil, paclitaxel, TCPOBOP and untreated) using cryo-pulverization and sonication method. The extracts were digested with trypsin ii and the resulting peptides labelled with 4-plex iTRAQ reagents. The labelled peptides were subjected for separation in two-dimensions by iso-electric focusing (IEF) and RP-HPLC techniques before analysis by mass spectrometry and database searching for protein identification. Set A and Set B resulted in identification and quantification of 1146 and 1743 proteins, respectively. Moreover, Set A and Set B recovered 26 and 34 cytochrome P450 isoforms, respectively. The microsomal changes after drug treatments were quite similar. However, more changes were observed in the male set. Up-regulation of MUPs showed the greatest distinction in the protein expression patterns in the treated samples comparing to the untreated controls. In Set A, 5-fluoruracil and cisplatin increased the expression of three isoforms (MUP1, 2, and 6), whereas doxorubicin has increased the expression of four isoforms (MUP1, 2, 3, and 6). On the other side, only TCPOBOP in Set B has increased the expression of two isoforms (MUP1 and 6). Our findings showed that the expression of MUP, normally involved in binding and excretion of pheromones, have drug- and sex-specific differences. The mechanism and significance of MUP up-regulation are ambiguous. Therefore, the impact of each therapeutic agent on MUP and xenobiotic enzymes will be discussed.

No description available.

A fim de prevenir a rejeição do órgão transplantado pelo hospedeiro, se faz necessário o uso de drogas imunossupressoras, como a ciclosporina, que pode levar ao aparecimento de efeitos colaterais como hipertensão arterial, nefrotoxicidade, hepatotoxicidade, e hiperplasia gengival medicamentosa (HGM), que pode ser potencializada se bloqueadores de canal de cálcio como a nifedipina forem associados a fim de controlar a pressão arterial. A patogênese da HGM ainda é incerta, entretanto fatores como a presença de cálculo e placa, concentração plasmática da droga, idade e fatores hormonais podem influenciar as características clínicas e o desenvolvimento da HGM. Recentemente, alguns vírus têm sido associados com a HGM. O HPV (Papiloma Vírus Humano) tem sido associado com casos severos de HGM, enquanto que o EBV (Vírus Epstein-Barr) é associado ao aparecimento de desordens linfoproliferativas pós transplante, que se apresentam como HGM. O objetivo deste trabalho foi avaliar a freqüência e o grau da HGM em pacientes transplantados renais (TR), identificar o EBV e HPV na HGM destes pacientes, e correlacionar a HGM, índice de placa, presença de cálculo e presença do EBV e HPV nos pacientes TR. Foram examinados os prontuários de 58 pacientes TR atendidos no CAPEFOUSP, e os dados com relação à medicação imunossupressora em uso e presença ou ausência de HGM foram registrados. Foram contatados 15 pacientes TR, dos quais foram colhidos dados demográficos, história médica, drogas em uso e história dental. No exame intra-oral foram observados o índice de placa, grau da HGM e presença de cálculo. A HGM foi removida e enviada a Disciplina de Patologia Bucal para análise microscópica. Os espécimes removidos foram comparados com um grupo controle composto por 20 casos de hiperplasia gengival inflamatória. Ambos os grupos foram submetidos ao exame de rotina, enfatizando a presença de coilócitos e a análise molecular, com hibridização in situ para o EBV (sondas EBER e Lytic) e HPV (sonda de amplo espectro e tipos 6/11, 16/18 e 31/33 nos casos positivos para a sonda de amplo espectro). 42% dos pacientes apresentaram HGM grau 1, 50% grau 2 e 8% grau 3. Cálculo estava presente em 50% dos pacientes. O índice de placa médio encontrado foi de 72%. Todas as amostras gengivais removidas cirurgicamente apresentaram um quadro histopatológico compatível com HGM. Os coilócitos estavam presentes em 100% dos casos do grupo de estudo e em 80% dos casos do grupo controle. O HPV esteve presente em 20% dos casos do grupo de estudo e em 10% do grupo controle. O EBV estava presente em 100% dos casos do grupo de estudo e em 90% dos casos do grupo controle, para ambas as sondas, entretanto no grupo de estudo foi observada uma expressão maior do EBV, tanto em quantidade de células marcadas, como em áreas mais profundas. Concluímos que a maioria dos pacientes TR apresentou HGM leve a moderada; EBV foi encontrado em todos os pacientes TR, caracterizando uma infecção oportunista, enquanto que o HPV foi encontrado nas mesmas proporções nos pacientes TR e no grupo controle; não foi encontrada correlação entre índice da HGM, índoce de placa, presença de cálculo e presença do EBV e HPV. / In order to prevent graft rejection in organ transplantation, is necessary the use of immunosuppressive drugs, as cyclosporin, that has several side effects, such as high blood pressure, nephrotoxicity, hepatotoxicity and gingival overgrowth (GO), that can be increased if calcium channel blockers, such as nifedipine, are associated in order to control de blood pressure. The pathogenesis of GO is still uncertain, but some factors such as the presence of calculus and plaque, drug plasmatic concentration, age and hormonal factors can influence the clinical aspects and development of GO. Recently some virus have been associated to GO as well. HPV (Human Papilloma Virus) have been associated to severe cases of GO and EBV (Epstein-Barr Virus) have been associated to posttransplantation lymphoproliferative disorders presenting as GO. The aim of this work was to evaluate GO incidence and score in renal transplant patients (RTP), identify EBV and HPV in GO from RTP, and correlate GO, plaque score, presence of calculus, and presence of EBV and HPV in RTP. We reviewed 58 charts from RTP attending to Special Care Dentistry Center (CAPE-FOUSP). Immunosuppressant drugs and presence or absence of GO were registered. 15 RTP were asked to show up in order to be examined. We collected demographic data, medical history, drugs in use and dental history. In intra-oral exam we observed plaque score, GO score and presence of calculus. GO were removed and sent to Oral Pathology Department for microscopic analysis. GO was compared to a control group composed by 20 cases of inflammatory gingival hyperplasia and both groups were submitted to routine exam emphasizing the presence of koilocytes and to molecular analysis with in situ hybridization for EBV (EBER and Lytic probes) and for HPV (wide spectrum probe and 6/11, 16/18, 31/33 types in cases where wide spectrum were positive). 42% of the patients presented GO score 1, 50% score 2 and 8% score 3. Calculus were presented in 50% of the patients. The average of plaque score was 72%.All GO specimens removed had a histopathological exam compatible with drug induced gingival overgrowth. Koilocytes were presented in 100% of study group (SG) and in 80% of control group (CG). HPV were presented in 20% of the SG and in 10% of the CG. EBV was presented in 100% of SG and in 90% of CG, for both probes, but in SG it could be observed in deeper areas of the epithelium and in a more pronounced expression. We concluded that most RTP presented mild to moderate GO, EBV were found in all RTP, characterizing an opportunistic infection, while HPV were found in the same proportions than in the control group and there were no statistical correlation between GO, plaque score, presence of calculus and presence of EBV and HPV.

by Wong Wing-yee, Felice. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 144-166). / Abstract also in Chinese. / Acknowledgements --- p.i / List of Abbreviations --- p.ii / Abstract --- p.iv / Abstract (Chinese Version) --- p.vi / Table of Contents --- p.viii / List of Tables --- p.xii / List of Figures --- p.xiv / List of Appendices --- p.xvi / Chapter Chapter I --- Literature Review / Chapter 1. --- Introduction --- p.1 / Chapter 2. --- Background of Cytochrome P450 --- p.3 / Chapter 2.1 --- Discovery --- p.3 / Chapter 2.2 --- Tissue Distribution --- p.3 / Chapter 2.3 --- Structure and Functions --- p.7 / Chapter 2.4 --- Nomenclature of the P450 Superfamily --- p.10 / Chapter 3. --- Cytochrome P450 2E1 (CYP2E1) --- p.11 / Chapter 3.1 --- Discovery --- p.11 / Chapter 3.2 --- Tissue Distribution --- p.12 / Chapter 3.3 --- Substrates and Inducers --- p.13 / Chapter 3.4 --- Toxicological Role of CYP2E1 --- p.15 / Chapter 4. --- CYP2E1-knockout Mouse Model --- p.17 / Chapter Chapter II --- Carbon Tetrachloride (CC14) Study / Chapter 1. --- Introduction --- p.19 / Chapter 1.1 --- General Properties and Usage of CC14 --- p.19 / Chapter 1.2 --- Toxicological Aspects of CC14 --- p.19 / Chapter 1.3 --- Mechanism of CCl4-induced Hepatotoxicity --- p.20 / Chapter 1.4 --- Role of CYP2E1 in CCl4-induced Hepatotoxicity --- p.23 / Chapter 1.5 --- Objectives of the Study --- p.27 / Chapter 2. --- Materials and Methods --- p.29 / Chapter 2.1 --- Chemicals and Materials --- p.29 / Chapter 2.2 --- Animals --- p.29 / Chapter 2.3 --- Acute CC14 Treatment --- p.29 / Chapter 2.4 --- Preparation of Microsomal Fractions --- p.30 / Chapter 2.5 --- Determination of Microsomal Protein Concentration --- p.31 / Chapter 2.6 --- Determination of Serum Aminotransferase Activities --- p.31 / Chapter 2.7 --- Liver Histology --- p.32 / Chapter 2.8 --- Hepatic Microsomal CYP2E1 Activity -p-nitrophenol Assay --- p.34 / Chapter 2.9 --- SDS-PAGE and Western Blot Analysis --- p.35 / Chapter 2.10 --- Detection of Lipid Peroxidation in vitro and in vivo --- p.35 / Chapter 2.10.1 --- In vitro Lipid Peroxidation - 2-Thiobarbituric Acid (TBA) assay --- p.35 / Chapter 2.10.2 --- In vivo Lipid Peroxidation - Microsomal Conjugated Dienes Detection --- p.36 / Chapter 2.11 --- Hepatic Lipid Fatty Acid Composition Analysis --- p.39 / Chapter 2.11.1 --- Lipid Extraction --- p.39 / Chapter 2.11.2 --- Thin Layer Chromatography --- p.39 / Chapter 2.11.3 --- Methylation --- p.40 / Chapter 2.11.4 --- Gas Chromatography --- p.40 / Chapter 2.12 --- Statistical Analysis --- p.41 / Chapter 3. --- Results --- p.42 / Chapter 3.1 --- "Mortality, Liver Weight and Liver Color" --- p.42 / Chapter 3.2 --- Hepatotoxicity --- p.42 / Chapter 3.2.1 --- Serum ALT and AST activities --- p.42 / Chapter 3.2.2 --- Liver Histology --- p.45 / Chapter 3.3 --- CYP2E1-catalysed PNP Activities and CYP2E1 Protein Levels --- p.49 / Chapter 3.3.1 --- CYP2El-catalyzed PNP Activities --- p.49 / Chapter 3.3.2 --- CYP2E1 Protein Levels --- p.52 / Chapter 3.4 --- Lipid Peroxidation --- p.52 / Chapter 3.4.1 --- In vitro Lipid Peroxidation --- p.52 / Chapter 3.4.2 --- In vivo Lipid Peroxidation --- p.54 / Chapter 3.5 --- Hepatic Lipid Fatty Acid Composition --- p.56 / Chapter 3.5.1 --- Fatty Acid Composition in Hepatic Phospholipid --- p.56 / Chapter 3.5.2 --- Fatty Acid Composition in Hepatic Microsomal Phospholipid --- p.59 / Chapter 3.5.3 --- Fatty Acid Composition in Hepatic Triglyceride --- p.61 / Chapter 4. --- Discussion --- p.63 / Chapter 4.1 --- CYP2E1 is Required in CCl4-mediated Hepatotoxicity --- p.63 / Chapter 4.2 --- CYP2E1 is Degraded following CC14 Exposure --- p.65 / Chapter 4.3 --- CYP2E1 is Required in CCl4-induced Lipid Peroxidation --- p.67 / Chapter 4.4 --- CYP2E1 is Required in CCl4-induced Hepatic Phospholipid Depletion --- p.70 / Chapter 4.5 --- CYP2E1 is Required in CCl4-induced Hepatic Triglyceride Accumulation --- p.72 / Chapter 5. --- Conclusion --- p.76 / Chapter Chapter III --- Chronic Ethanol Consumption Study / Chapter 1. --- Introduction --- p.77 / Chapter 1.1 --- Multiple Metabolic Pathways for Ethanol Metabolism --- p.77 / Chapter 1.2 --- Metabolism of Ethanol by the Microsomal Ethanol Oxidizing System --- p.79 / Chapter 1.3 --- Role of CYP2E1 in Ethanol Metabolism --- p.82 / Chapter 1.4 --- Role of CYP2E1 in Alcoholic Liver Disease and Associated Oxidative Stress --- p.84 / Chapter 1.5 --- Objectives of the Study --- p.89 / Chapter 2. --- Materials and Methods --- p.90 / Chapter 2.1 --- Chemicals and Materials --- p.90 / Chapter 2.2 --- Animals --- p.90 / Chapter 2.3 --- Chronic Ethanol Treatment --- p.90 / Chapter 2.3.1 --- Ethanol Diet Composition --- p.90 / Chapter 2.3.2 --- Ethanol Feeding --- p.90 / Chapter 2.4 --- Monitoring of Blood Ethanol Levels --- p.96 / Chapter 2.5 --- Preparation of Microsomal Fractions --- p.96 / Chapter 2.6 --- Determination of Microsomal Protein Concentration --- p.97 / Chapter 2.7 --- Determination of Serum Aminotransferase Activities --- p.98 / Chapter 2.8 --- Liver Histology --- p.98 / Chapter 2.9 --- SDS-PAGE and Western Blot Analysis --- p.99 / Chapter 2.10 --- Hepatic Fatty Acid Composition Analysis --- p.100 / Chapter 2.10.1 --- Lipid Extraction --- p.100 / Chapter 2.10.2 --- Thin Layer Chromatography --- p.101 / Chapter 2.10.3 --- Methylation --- p.101 / Chapter 2.10.4 --- Gas Chromatography --- p.102 / Chapter 2.11 --- Statistical Analysis --- p.103 / Chapter 3. --- Results --- p.104 / Chapter 3.1 --- Average Food Consumption --- p.104 / Chapter 3.2 --- Average Ethanol Consumption for Ethanol Liquid Diet Feeding Group --- p.104 / Chapter 3.3 --- Body Weight Gain --- p.104 / Chapter 3.4 --- Blood Ethanol Levels --- p.108 / Chapter 3.5 --- "Mortality, Liver Weight and Liver Color" --- p.108 / Chapter 3.6 --- Serum ALT and AST Activities --- p.110 / Chapter 3.7 --- Liver Histology --- p.114 / Chapter 3.8 --- Western Blot Analysis --- p.119 / Chapter 3.9 --- Hepatic Lipid Fatty Acid Composition --- p.119 / Chapter 3.9.1 --- Fatty Acid Composition in Hepatic Phospholipid --- p.119 / Chapter 3.9.2 --- Fatty Acid Composition in Hepatic Triglyceride --- p.123 / Chapter 4. --- Discussion --- p.126 / Chapter 4.1 --- Nutrients Displacement after Chronic Ethanol Consumption --- p.126 / Chapter 4.2 --- Varied Blood Ethanol Levels after Chronic Ethanol Consumption --- p.127 / Chapter 4.3 --- Increase in CYP2E1 Levels after Chronic Feeding of Ethanolin WT mice --- p.127 / Chapter 4.4 --- Lack of Evidence Indicating the Development of Ethanol- Induced Liver Injury --- p.129 / Chapter 4.4.1 --- No Elevations in Serum ALT and AST Activities --- p.129 / Chapter 4.4.2 --- Normal Liver Histology --- p.130 / Chapter 4.4.3 --- Lack of Triglyceride Accumulation --- p.131 / Chapter 4.4.4 --- Elevations in Hepatic PL --- p.132 / Chapter 4.5 --- Possible Reasons for the Absence of Liver Damage after Chronic Ethanol Consumption in our Mouse Model --- p.134 / Chapter 5. --- Conclusion --- p.137 / Chapter Chapter IV --- Concluding Remarks / Chapter 1. --- A Comparison between Acute CC14 Study and Chronic Ethanol Consumption Study --- p.139 / Chapter 1.1 --- Regulation of CYP2E1 Expression --- p.139 / Chapter 1.2 --- Free Radical Production Involved in CC14- and Chronic Ethanol Consumption-Mediated Liver Injury --- p.140 / Chapter 1.3 --- An Overall Comparison between CC14 study and Chronic Ethanol Consumption Study --- p.140 / Chapter 2. --- Future Studies --- p.142 / Chapter 2.1 --- Acute CC14 Study --- p.142 / Chapter 2.1.1 --- Calcium Homeostasis Studies --- p.142 / Chapter 2.1.2 --- Spin Trapping Studies --- p.142 / Chapter 2.2 --- Chronic Ethanol Study --- p.142 / Chapter 2.2.1 --- "Generation of a Heterozygous ""Ethanol-Sensitive"" Mouse Strain (SV/129/ter x C57BL/6)" --- p.143 / Chapter 3. --- Concluding Remarks --- p.143 / References --- p.144 / Appendix --- p.167

Diabetic pregnancy is associated with increased risk of congenital malformations. Previous studies have shown that maternal diabetes can interact with the vitamin A metabolite, all-trans retinoic acid (RA), in increasing embryonic susceptibility to caudal regression and neural tube defects. The aim of this thesis is to investigate the cellular and molecular mechanisms that underlie this interaction. / First hypothesis. RA concentration in the embryo is tightly regulated by the synthesizing enzyme retinaldehyde dehydrogenase type II (RALDH2), and the degrading enzyme CYP26. Alteration in expression levels of these enzymes under maternal diabetes may affect the availability of RA and thus its teratogenicity. / In conclusion, results of this thesis provide insight into the mechanism of how maternal diabetes interacts with RA in enhancing embryonic susceptibility to congenital malformations. This is also the first report to show that maternal diabetes alters RA homeostasis. (Abstract shortened by UMI.) / Second hypothesis. The transfer of RA to the nucleus for molecular action is regulated by cytoplasmic cellular retinoic acid binding proteins CRABP-I and CRABP-II. Alteration in expression levels of these binding proteins under maternal diabetes may affect the amount of RA reaching the nucleus and thus its teratogenicity. / Third hypothesis. The action of RA is mediated via different nuclear retinoic acid receptors (RAR) and retinoid X receptors (RXR). Alteration in expression levels of these receptors under maternal diabetes may affect the efficacy of RA signal transduction and thus its teratogenicity. / Three hypotheses are proposed to explain the underlying mechanism of increased embryonic susceptibility to RA teratogenicity under maternal diabetes: / To investigate these hypotheses, expression levels of various genes in different groups were compared. Result show that there are no significant differences in mRNA expression levels of CRABP-I, CRABP-II, RARgamma, RARgamma and RXRalpha between embryos of diabetic and non-diabetic mice with or without RA treatment. In contrast, expression levels of Raldh2 and CYP26 are significantly reduced in embryos of diabetic mothers, and in embryos of non-diabetic mice cultured in vitro in hyperglycemic conditions. Moreover, embryos of diabetic mice show significantly reduced response to RA-induced up-regulation of CYP26. These findings suggest that the rate of degradation of RA is slower in embryos of diabetic mice and thus the teratogenic effect of RA is enhanced. / Leung Bo Wah. / "July 2005." / Adviser: Alisa S. W. Shum. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3779. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 158-198). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.