Alcoholism, clinical and experimental research
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Alcohol. Clin. Exp. Res. · Sep 2011
Role of snail activation in alcohol-induced iNOS-mediated disruption of intestinal epithelial cell permeability.
Chronic alcohol use results in many pathological effects including alcoholic liver disease (ALD). ALD pathogenesis requires endotoxemia. Our previous studies showed that increased intestinal permeability is the major cause of endotoxemia, and that this gut leakiness is dependent on alcohol stimulation of inducible nitric oxide synthase (iNOS) in both alcoholic subjects and rodent models of alcoholic steatohepatitis. The mechanism of the alcohol-induced, iNOS-mediated disruption of the intestinal barrier function is not known. We have recently shown that alcohol stimulates activation of the transcription factor Snail and biomarkers of epithelial mesenchymal transition. As activated Snail disrupts tight junctional proteins, we hypothesized that activation of Snail by iNOS might be one of the key signaling pathways mediating alcohol-stimulated intestinal epithelial cell hyperpermeability. ⋯ Our data confirmed our prior results and further demonstrated that alcohol-induced gut leakiness in rodents and intestinal epithelial cell monolayers is iNOS dependent. Our data also support a novel role for Snail activation in alcohol-induced, iNOS-mediated intestinal hyperpermeability and that PAK1 is responsible for activation of Snail at Ser246 with alcohol stimulation. Identification of these mechanisms for alcohol-induced intestinal hyperpermeability may provide new therapeutic targets for prevention and treatment of alcohol-induced leaky gut, endotoxemia, and endotoxin-associated complications of alcoholism such as ALD.
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Alcohol. Clin. Exp. Res. · Aug 2011
Extensive deep gray matter volume reductions in children and adolescents with fetal alcohol spectrum disorders.
The link between the numerous cognitive, motor, and behavioral difficulties of individuals with fetal alcohol spectrum disorders (FASD) and underlying specific structural brain injuries can be investigated using high-resolution imaging. Differential sensitivity of the brain's "relay" stations, namely the deep gray matter structures, may play a key factor given their multifaceted role in brain function. The purpose of our study was to analyze differences in deep gray matter volumes of children and adolescents with FASD relative to age/sex-matched controls and to examine whether any volume differences were consistent across the age range of neurodevelopment. ⋯ Significant, but variable, volume reductions throughout the deep gray matter are observed over a wide age range of 6 to 17 years in FASD.
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Alcohol. Clin. Exp. Res. · Aug 2011
Acute ethanol disrupts photic and serotonergic circadian clock phase-resetting in the mouse.
Alcohol dependence is associated with impaired circadian rhythms and sleep. Ethanol administration disrupts circadian clock phase-resetting, suggesting a mode for the disruptive effect of alcohol dependence on the circadian timing system. In this study, we extend previous work in C57BL/6J mice to: (i) characterize the suprachiasmatic nucleus (SCN) pharmacokinetics of acute systemic ethanol administration, (ii) explore the effects of acute ethanol on photic and nonphotic phase-resetting, and (iii) determine if the SCN is a direct target for photic effects. ⋯ These results confirm that acute ethanol attenuates photic phase-delay shifts and serotonergic phase-advance shifts in the mouse. This dual effect could disrupt photic and nonphotic entrainment mechanisms governing circadian clock timing. It is also significant that the SCN clock is a direct target for disruptive effects of ethanol on photic shifting. Such actions by ethanol could underlie the disruptive effects of alcohol abuse on behavioral, physiological, and endocrine rhythms associated with alcoholism.
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Alcohol. Clin. Exp. Res. · Jul 2011
Comparative StudyOutcomes of patients with alcohol use disorders experiencing healthcare-associated infections.
Healthcare-associated infections (HAI) affect 1.7 million patients annually in the United States, and patients with alcohol use disorders (AUD) are at increased risk of developing HAI. HAI have been shown to substantially increase the hospital length of stay, mortality, and cost. In a cohort of patients with HAI, we sought to determine mortality, cost, and hospital length of stay attributable to AUD. ⋯ Patients with AUD who experience HAI have worse outcomes compared with patients without AUD. Patients with AUD have higher mortality, longer hospital length of stay, and higher costs. Studies aimed at decreasing the morbidity and mortality of HAI in patients with AUD are warranted.
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Alcohol. Clin. Exp. Res. · Jul 2011
Comparative StudyEthanol alters BDNF-induced Rho GTPase activation in axonal growth cones.
The effects of ethanol on development of postmitotic neurons include altered neurite outgrowth and differentiation, which may contribute to neuropathology associated with fetal alcohol spectrum disorders. We previously reported that ethanol exposure alters axon growth dynamics in dissociated cultures of rat hippocampal pyramidal neurons. Given the important regulatory role of small Rho guanosine triphosphatases (GTPases) in cytoskeletal reorganization associated with axon growth, and reports that ethanol alters whole cell Rho GTPase activity in other cell types, this study explored the hypothesis that ethanol alters Rho GTPase activity specifically in axonal growth cones. ⋯ These results reveal an inhibitory effect of ethanol on growth cone signaling via small Rho GTPases during early stages of hippocampal development in vitro, and suggest a mechanism whereby ethanol may disrupt neurotrophic factor regulation of axon growth and guidance.