No description available.

No description available.

No description available.

No description available.

One percent of children in North America may be affected by fetal alcohol spectrum disorder (FASD). FASD remains difficult to diagnose because confirmation of maternal alcohol use is a diagnostic criterion, and women consuming alcohol during pregnancy are reluctant to divulge this information for fear of stigmatization and losing custody of the child. Consequently, using a biomarker to assess alcohol exposure would provide a tremendous advantage. Recently, the measurement of fatty acid ethyl ester (FAEE) in hair has provided a powerful tool for assessing alcohol exposure. My thesis fills a translational gap of research between the development of the FAEE hair test and its application in the context of FASD. The guinea pig has been a critical model for FASD research, in which FAEE hair analysis has previously distinguished ethanol-exposed dams/offspring from controls. My first study, reports a positive dose-concentration relationship between alcohol exposure and hair FAEE, in the human, and the guinea pig. Humans also displayed over an order of magnitude higher FAEE incorporation per equivalent alcohol exporsure, suggesting that the test will be a sensitive clinical marker of fetal alcohol exposure. My second study utilized multi-coloured rats to investigate the potential of a hair-colour bias, as has been reported for other clinical hair assays; no evidence of bias is reported here. My third study is the first to examine the clinical use of the FAEE hair test in parents at high risk of having children with FASD. Over one third of parents tested positive for excessive alcohol use. Parents were investigated by social workers working for child protection services, and my fourth study reports that hair FAEE results agree with social worker reports. Individuals highly suspected of abusing alcohol were at a significantly greater risk of testing positive, whereas individuals tested based on other reasons (such as to cover all bases) were negatively associated with testing positive. The last study of my thesis, confirmed an association between alcohol and drug use by parents at high risk for having children with FASD, posing an added risk to children. This work helps bridge a gap in translational research, suggesting that the FAEE hair test has potential for use in FASD diagnosis and research.

No description available.

An investigation of the factors influencing the inhibitory and toxic effects of ethanol and higher alcohols, byproducts of alcoholic fermentation, on yeast, is presented. The relative potency of alcohols was found to correlate strongly with the carbon chain-length or molecular size and the lipid solubility of the respective alcohols. Higher alcohols act synergistically with each other and with ethanol in causing cell death of suspensions of non-growing Saccharomyces cerevisiae. The presence of higher alcohols in fermented broth, even at low concentrations, and other by-products of alcoholic fermentation, could explain the higher potency of ethanol produced during fermentation compared to added ethanol. The kinetics of uptake of labelled ethanol supplied at different concentrations gave no evidence of enzymic involvement in the ethanol uptake process. The rate of release of labelled ethanol by cells fed labelled glucose paralled the rate of p14sC-C0b2s release. This does not support the view that ethanol accumulates within the cells to higher concentrations than occur in the medium. Supplementation of a basal synthetic medium with various nutrients did not confer additional survival capacity on yeast against the adverse effects of alcohol. Osmotic pressure did not influence alcohol toxicity below 10% (w/v) sorbitol equivalent of osmotic pressure. Alcohol toxicity is not influenced by hydrogen ion concentration (pH) over a range of pH 5.3 to 3.5.

The combined use of alcohol and caffeine has been identified as a public health concern, and yet, our knowledge of this type of use and how it relates to the risk of incurring an alcohol-related injury remains limited. Study 1 is a systematic review examining and critically analyzing the literature on the combined use of alcohol with energy drinks and the risk of injury. Studies 2 and 3 use data from a controlled Emergency Department (ED) study that was collected over 1.5 years from 3 separate hospitals in British Columbia. There was a total of 2804 participants across the ages of 18-98. Given the strengths and limitations of these different methodologies, both case-crossover and case-control analyses were performed in order to test for consistency of results. Study 2 examined the temporal association between alcohol and caffeine and use (Alc+Caff) and the risk of injury, as well as the potential moderating role of risk-taking propensity and mediating role of Alc+Caff between risk-taking propensity and injury risk. The combined use of alcohol and caffeine was found to be associated with a higher risk of injury, even after controlling for dose of alcohol and caffeine, other substance use, location at time of injury, risk-taking propensity, and sociodemographic variables. Alcohol and caffeine use was also found to partially mediate the relationship between risk-taking propensity and injury. Study 3 examined gender differences in the risk-relationship of Alc+Caff use and injury by testing the interaction between gender and Alc+Caff use and then examining the risk of injury following Alc+Caff use separately for men and women. Women were found to have a significantly higher risk of injury following alcohol use and Alc+Caff use relative to men. These results were found in both the case-crossover and case-control analyses. The findings from these studies indicate a relationship between Alc+Caff use and an increased risk of injury, especially for women, which is supported by previous research. The results are supportive of differential low-risk drinking guidelines for men and women. The findings also offer a significant contribution to our knowledge base, as the use of standardized measures and inclusion of multiple confounding variables allowed for the examination of the unique effect of Alc+Caff use. Alc+Caff use is associated with an increased risk of injury that cannot solely be explained by increased alcohol consumption, other substance use, risk-taking propensity, location at time of injury, or sociodemographic factors. Based on the epidemiological criteria of causation, the findings contribute evidence supportive of an inference of causality between Alc+Caff use and injury. The results of the current studies also offer suggestions for future research needed in this area, and provide recommendations for policy prevention and intervention efforts to reduce the harm associated with this type of consumption. / Graduate / 2020-07-01

A dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine / Fetal Alcohol Syndrome (F AS), the most severe form of Fetal Alcohol Spectrum Disorder (F ASD), has traditionally been associated with maternal alcohol consumption during pregnancy. However, a number of animal studies have shown an association between paternal preconception alcohol consumption and developmental abnormalities in the offspring that resemble the features of F AS. Dysregulation of epigenetic factors (such as DNA methylation) in the presence of alcohol may provide a plausible mechanism by which paternal alcohol consumption could result in offspring affected with features of F AS. Imprinted genes are expressed in a parentof- origin manner due to DNA methylation at distinct differentially methylated regions (DMRs) and are essential for normal embryonic development. There are only two known paternally methylated DMRs in humans, with an additional one described in mice - associated with Rasgrfl. The first aim of this study was to determine whether the human RASGRFl gene contains a DMR and whether this DMR is paternally methylated. In order to assess the imprint status of RASGRF 1, a number of computational assessments were done to identify key features of imprinted loci. Pyrosequencing analysis was used to assess the methylation status of various CpO islands surrounding RASGRFi in peripheral blood and sperm DNA samples. The RASGRF i-associated CpO regions were not found to exhibit differential methylation in a parent-of-origin manner. The second aIm of the study was to examine the effect of paternal alcohol consumption on the methylation status of the IG-DMR locus in male gametes and to detennine whether alcohol is correlated with methylation in a dose-dependant manner. Methylation assessment was done using the quantitative pyrosequencing technology. While an overall reduction in methylation was noted in males who consumed alcohol after adjusting for confounding variables, the amount of alcohol consumed did not correlate with overall methylation. When analyzed by individual CpG sites, alcohol consumption was found to correlate preferentially with demethylation at CpG 3 while alcohol-dosage preferentially correlated with demethylation at CpG 7. Age was significantly correlated with an increase in the overall methylation at JG-DMR and at individual sites within JG-DMR. In conclusion, these findings support the hypothesis that paternal preconception alcohol consumption can lead to hypomethylation of nonnally hypennethylated DMRs of specific imprinted genes in human spenn. This in tum could have significant implications with regard to the regulation of developmentally significant genes in the zygote and fetus, resulting in developmental, behavioral and neurocognitive disorders.

PhD, Faculty of Health Sciences, University of the Witwatersrand, 2008 / Fetal alcohol spectrum disorders (FASD) describe the range of disorders that result from in utero alcohol exposure. FASD is a serious global health problem and is observed at exceedingly high frequencies in certain South African communities. Although in utero alcohol exposure is the primary trigger, there is evidence that genetic- and other susceptibility factors contribute towards FASD development. To date, no genome-wide association or linkage studies have been performed for any of the FASD syndromes. The main objectives of this study were to develop an innovative approach to computationally identify biologically plausible candidate genes for FASD, for a future association study, and to evaluate the appropriateness and validity of this approach. Further, an in silico analysis of known single nucleotide polymorphisms (SNPs) within the top-ranked candidate gene was performed in conjunction with de novo SNP detection, to select a subset of SNPs based on proposed functional impact on gene expression and protein function, for a prospective association study. A computational binary filtering technique was designed that can be employed to prioritize genes in a candidate list, or could be used to rank all genes in the genome in the absence of such a list. 10174 FASD candidate genes were initially selected from the whole genome using a previously described method. Hereafter the candidates were prioritized using a binary filtering technique. The biological enrichment of the ranked genes was assessed by investigating the protein-protein interactions, functional enrichment and common promoter element binding sites of the top-ranked genes. A group of 87 genes was prioritized as candidates highlighting many strong candidates from the TGF-/, MAPK and Hedgehog signalling pathways, which are all integral to fetal development and potential targets for alcohol's teratogenic effect. To assess the effectiveness and accuracy of this computational approach, X-linked mental retardation (XLMR) was used as a test disease, considering that XLMR is a set of heterogeneous disorders of which some of the underlying genetics is known. This implementation resulted in a prioritized gene list with a noted enrichment of known XLMR genes among the top-ranked genes. Furthermore, the top-ranked list contained genes that were biologically relevant to XLMR, and could potentially be as yet unknown candidate genes for XLMR. Indeed, many of the top-ranked genes mapped to XLMR candidate regions, confirming their status as good candidates. Finally, a subset of seven known and novel SNPs was selected within FGFR1 based on putative functional impact. Data from the HapMap project was used to identify tag SNPs for FGFR1 to complement the selection made based on function. The main limitation of the proposed computational approach to candidate gene prediction is that it is primarily based on gene annotation, and that it is therefore biased towards selecting better-annotated genes. However, the results obtained in this study suggest that the described computational method is an effective approach that can identify likely candidates that are biologically relevant to the disease of interest, and therefore appropriate for a candidate-gene association studies. In practice, this technique is an appropriate approach to select a workable set of candidate genes for a complex disease, in a setting where a whole-genome association study is not a viable option.