Effects of alcohol on the fetus: impact and prevention.

In the spectrum of adverse effects on the fetus or infant associated with maternal drinking during pregnancy the most dramatic is the fetal alcohol syndrome, a pattern of malformation that has been associated with maternal alcohol abuse. Other undesirable outcomes of pregnancy linked to alcohol exposure in utero include growth deficiency, major and minor anomalies, decrements in mental and motor performance, and fetal and perinatal wastage. Alcohol, like other teratogens, does not uniformly affect all those exposed to it. Rather, there seems to be a continuum of effects of alcohol on the fetus with increasingly severe outcomes generally associated with higher intakes of alcohol by the mother. The cost of fetal damage associated with alcohol exposure is very high. A program to decrease the incidence of fetal alcohol effects is therefore imperative. The cornerstone of such a program must be not only education of the public but also careful training of all professionals who provide health care for pregnant women.     

Cumulative effects of alcohol (ethanol) on the activity of Purkinje cells in the cat cerebellum

The effects of three consecutive injections of 2 ml/kg 30% alcohol (ethanol, i.v.) on the activity of identified cerebellar Purkinje cells were investigated during experiments on adult cats anesthetized by a Nembutal-chloralose mixture. It was found that repeated alcohol injections exert a cumulative effect on the firing rate of these cells. The alcohol-induced rise in Purkinje cell firing rate, produced by excitation of the mossy fibers, was generally accompanied by a reduction in that of cells responding to excitation of climbing fibers. The inhibitory pause occurring after complex discharges in cerebellar Purkinje cells grew shorter with successive alcohol injections.I. M. Sechenov Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Translated from Neirofiziologiya, Vol. 19, No. 1, pp. 74–80, January–February, 1987.     

Amperometric ethanol biosensor based on poly(vinyl alcohol)-multiwalled carbon nanotube-alcohol dehydrogenase biocomposite

A novel amperometric ethanol biosensor was constructed using alcohol dehydrogenase (ADH) physically immobilized within poly(vinyl alcohol)–multiwalled carbon nanotube (PVA–MWCNT) composite obtained by a freezing–thawing process. It comprises a MWCNT conduit, a PVA binder, and an ADH function. The measurement of ethanol is based on the signal produced by β-nicotinamide adenine dinucleotide (NADH), the product of the enzymatic reaction. The homogeneity of the resulting biocomposite film was characterized by atomic force microscopy (AFM). The performance of the PVA–MWCNT–ADH biocomposite modified glassy carbon electrode was evaluated using cyclic voltammetry and amperometry in the presence of NADH and in the presence of ethanol. The ethanol content in standard solutions was determined and a sensitivity of 196 nA mM⁻¹, a linear range up to 1.5 mM, and a response time of about 8 s were obtained. These characteristics allowed its application for direct detection of ethanol in alcoholic beverages: beer, red wine, and spirit.     

Effects of differential alcohol dehydrogenase activity on the developmental toxicity of ethanol in Drosophila melanogaster

The role of alcohol dehydrogenase (ADH) activity in ethanol toxicity was investigated in Drosophila melanogaster. Flies from three congenic Adh strains (high, medium, and low ADH activity) were allowed to deposit eggs on medium containing 0, 4, or 8% ethanol. The resulting larvae were allowed to complete their development in the medium, and emerging flies were examined for defects. Flies with high ADH activity had malformation incidences of 0.8, 2.4, and 5.2% at 0, 4, and 8% ethanol, respectively. The comparable incidences for the low ADH strain were 1.0, 4.1, and 8.4%, while those for the medium ADH strain were intermediate in value. These results indicate that ethanol teratogenesis may be inversely related to ADH activity. When larvae were treated with ethanol for different lengths of time during development, the incidence of defects in flies from the high ADH strain was 3.9% when exposure started at the first instar and 3.09% when exposure started at the third instar. Results of the same exposures for the intermediate ADH strain were 5.2 and 3.4%, respectively, while those for the low ADH strain were 6.9 and 5.5%, respectively. Thus, length of ethanol exposure was directly related to the increased incidence of malformations in all tested Drosophila strains. For all tested strains, defect incidences appeared to be dose-related as well, regardless of length of exposure. ADH in Drosophila has a dual function and thus can catalyze oxidation of both ethanol and its toxic metabolite, acetaldehyde. This suggests that ethanol is the proximate teratogen in Drosophila.     

Effects of dihydroergotoxine (hydergine) on peripheral blood alcohol levels

To examine the effects of dihydroergotoxine (DHET) on peripheral blood ethanol levels of adult female mice, ethanol (2 g/kg) was administered orally, either alone or in combination with DHET (2, 4, or 8 mg/kg). Blood was drawn after the first day of drug administration (acute study) and again after 21 days (chronic study). Two additional groups of mice received a single dose of ethanol (2 g/kg) and DHET (2 mg/kg) 15 minutes apart, one group receiving ethanol first, the other DHET as the first dose. Blood samples (100μ1) were collected from the tail vein at 5, 15, 30, 60, 120 and 180 minutes after treatment. Samples were analyzed by headspace gas chromatography. Results indicate that (a) combining ethanol with DHET significantly reduced blood ethanol levels compared to administration of ethanol alone, (b) chronic conditions produced higher blood ethanol levels, and (c) administration of ethanol 15 minutes before DHET produced a 27% lowering of peripheral blood alcohol levels compared to the reverse order of administration. These data suggest that DHET may be useful for alleviating some of the symptoms associated with alcohol intoxication.     

Disruption of circulation by ethanol promotes fetal alcohol spectrum disorder (FASD) in medaka (Oryzias latipes) embryogenesis

Japanese medaka (Oryzias latipes) embryos exposed to ethanol have developed craniofacial, cardiovascular and skeletal defects which can be compared with the phenotypic features of fetal alcohol spectrum disorder (FASD) observed in human. The present experiment was designed to show that the disruption in circulation by ethanol during embryogenesis is a potential cause of FASD. Fertilized eggs were exposed to ethanol (0, 100 and/or 400 mM) for 24 or 48 h at various developmental stages (Iwamatsu stages 4-30) and were analyzed at 6 day post fertilization (dpf). It was observed that controls and the embryos exposed to 100 mM ethanol were in circulating state; however, a significant number of embryos of stages 4-24 exposed to 400 mM ethanol had disrupted circulation. Compared to controls, protein and RNA contents were significantly reduced in non-circulating embryos. Lipid peroxidation (LPO) analysis was made at 3, 6, 24, 48, 96 and 144 hour post fertilization (hpf). LPO was increased with the advancement of morphogenesis; however, ethanol or the circulation status had no effect. We further analyzed alcohol dehydrogenase (Adh 5 and adh8) and aldehyde dehydrogenase (Aldh9A and Aldh1A2) enzyme mRNAs in the embryos exposed to 400 mM ethanol for 24 h. A developmental stage-specific reduction in these enzyme mRNAs by ethanol was observed. We conclude that ethanol-induced disruption in circulation during embryogenesis is a potential cause of the development of FASD features in medaka.     

Effects of ethanol on brain monoamine content of spontaneously hypertensive rats (SHR)

Spontaneously hypertensive rats (SHR) were administered either 2.4 g/kg ethanol or an isocaloric glucose daily for 4 weeks and the levels of norepinephrine (NE), epinephrine (EP), dopamine (DA), serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in different brain regions were determined. Results indicated a 3-fold increase in NE level in brain stem and hypothalamus and more than 2-fold increase in DA in corpus striatum in alcohol-treated rats as compared to controls. There was a significant increase in the level of DA in the corpus striatum but the levels in cerebral cortex, brain stem and hippocampus were decreased instead. Decreases in 5-HT levels were found in hypothalamus, brain stem, cortex and cerebellum of alcohol-treated brain as compared to untreated controls. These results indicate alterations of the biogenic amine contents in different regions of the SHR brain after chronic ethanol ingestion. Since stimulated release of biogenic amines in the SHR brain has been implicated in the regulation of blood pressure, changes due to ethanol ingestion may be a risk factor in hypertensive patients.     

Selection at the alcohol dehydrogenase locus of Drosophila melanogaster: Effects of ethanol and temperature

Drosophila melanogaster larvae were subjected to 10 generations of selection on 6% ethanol at 17, 25, and 30°C. For each temperature there was a significant (P<0.01) increase in the frequency of the Adh isoallele. Controls with no ethanol showed no change in the frequency of the Adh ^F isoallele. Larvae subjected to stronger selection on 8% ethanol confirmed the results. When adults of various ages were subjected to 16 and 32°C, the ADH^F isoenzyme retained its twofold advantage in activity over ADH^S regardless of the temperature. The same result was obtained with larvae at 16 and 35°C. Although some effect of temperature was demonstrated, it was concluded that the effect was not strong enough for temperature to be a selective factor under the conditions studied. However, ethanol is a strong selective factor for laboratory populations.     

Production of a chiral alcohol, 1-(3,4-dihydroxyphenyl) ethanol, by mushroom tyrosinase

1-(3,4-Dihydroxyphenyl) ethanol was produced biocatalytically for the first time using mushroom tyrosinase. 4-Ethylphenol at 1 mM was consumed over 12 min giving 0.23 mM 4-ethylcatechol and 0.36 mM (R/S)-1-(3,4-dihydroxyphenyl) ethanol (ee 0.5 %). Mushroom tyrosinase consumed 4-ethylphenol at 6.7 μmol min^?1 mg protein^?1 while the rates of formation of 4-ethylcatechol and 1-(3,4-dihydroxyphenyl) ethanol were 1.1 and 1.9 μmol min^?1 mg protein^?1. Addition of the ascorbic acid, as a reducing agent to biotransformation reactions, increased 4-ethylcatechol formation by 340 %. However, accumulation of 1-(3,4-dihydroxyphenyl) ethanol was not observed in the presence of ascorbic acid. While the 1-(3,4-dihydroxyphenyl) ethanol was racemic, it is the first chiral product produced by tyrosinase starting from a non-chiral substrate.     

Campylobacter fetus Subspecies jejuni (Vibrio fetus) from Commercially Processed Poultry

Three isolates of the human and animal pathogen Campylobacter fetus ss. jejuni (Vibrio fetus) were obtained from 165 poultry meat samples purchased from local retail stores.     

Tube Culture Method for Viable Counts of Campylobacter fetus (Vibrio fetus)

A method was developed for making viable counts of Campylobacter fetus (Vibrio fetus) in tube cultures using a medium containing alkaline hematin and incubation in a carbon dioxide incubator.     

Kinetics of ethanol inhibition in alcohol fermentation

The inhibitory effect of ethanol on yeast growth and fermentation has been studied for the strain Saccharomyces cerevisiae ATCC No. 4126 under anaerobic batch conditions. The results obtained reveal that there is no striking difference between the response of growth and ethanol fermentation. Two kinetic models are also proposed to describe the kinetic pattern of ethanol inhibition on the specific rates of growth and ethanol fermentation: \documentclass{article}\pagestyle{empty}\begin{document}$$\begin{array}{*{20}c} {\frac{{\mu _i }}{{\mu _0 }} = 1{\rm } - {\rm }\left( {\frac{P}{{P_m }}} \right);\alpha } \hfill & {\left( {{\rm for}\ {\rm growth}} \right)} \hfill \\ {\frac{{\nu _i }}{{\nu _0 }} = 1{\rm } - {\rm }\left( {\frac{P}{{P'_m }}} \right);\beta } \hfill & {\left( {{\rm for}\ {\rm ethanol}\ {\rm production}} \right)} \hfill \\ \end{array}$$\end{document} The maximum allowable ethanol concentration above which cells do not grow was predicted to be 112 g/L. The ethanol-producing capability of the cells was completely inhibited at 115 g/L ethanol. The proposed models appear to accurately represent the experimental data obtained in this study and the literature data.     

The role of maternal alcohol damage on ethanol teratogenicity in the rat

To study the severity and degree of in utero alcohol effects in relation to the rate of maternal alcohol damage, multiparous 1-year alcohol-fed rats were used, with an appropriate pair-fed control group. During pregnancy, alcoholic dams showed relatively high acetaldehyde levels (41 +/- 19 mumol/l) and blood alcohol levels of 22.8 +/- 14 mmol/l. They also showed marked histological alterations in liver as well as high serum aspartate-aminotransferase, alanine-aminotransferase, alkaline phosphatase, glutamate dehydrogenase, and gamma-glutamyltransferase activities. The increase in serum enzyme levels did not correlate with an increase in hepatic enzyme levels since only glutamate dehydrogenase was enhanced in liver after 1 year of alcohol intake. In addition, except for an increase in low Km aldehyde dehydrogenase activity, there were no changes in liver alcohol metabolizing enzymes in chronic alcohol vs. pair-fed females. Alcoholic rats showed a high incidence of damage in their progeny (resorptions, immature fetuses, decrease in fetal weight, etc.), and rats with the highest serum levels of the above enzymes (especially glutamate dehydrogenase and gamma-glutamyl transferase) had severely affected progeny. Rats with minimal histological liver damage, in contrast, did not show resorptions. Thus, the results presented suggest that the stage of maternal alcohol illness, as indicated mainly by the extent of liver damage, plays an important role in the frequency and severity of in utero alcohol effects in the rat.     

Main ethanol metabolizing alcohol dehydrogenases (ADH I and ADH IV): biochemical functions and the physiological manifestation

The range of the biochemical reactions which can be catalyzed by ADH I and ADH IV is extremely wide. The most characterized functions of these enzymes are protection against excess endogenous acetaldehyde, products of lipid peroxidation, exogenous alcohols and some xenobiotics. It was found also that ADH I and ADH IV are important members of the enzyme system synthesizing retinoic acid (especially during embryogenesis). They can oxidize some steroids and participate in bioamine and prostaglandin metabolism but so far the extent of their contribution to the latter processes is under discussion. Recent data suggest a correlation between the activity of ADH I in some organs and fine physiological processes including behavior regulation and craving for alcohol in albino rats.     

Determining the roles of the three alcohol dehydrogenases (AdhA,AdhB and AdhE) in Thermoanaerobacter ethanolicus during ethanol formation

Journal of Industrial Microbiology & Biotechnology - Thermoanaerobacter ethanolicus is a promising candidate for biofuel production due to the broad range of substrates it can utilize and its...     

The aldehyde/alcohol dehydrogenase (AdhE) in relation to the ethanol formation in Thermoanaerobacter ethanolicus JW200

A bifunctional aldehyde/alcohol dehydrogenase gene (adhE) from Thermoanaerobacter ethanolicus JW200 was identified and cloned. To unambiguously characterize the activity of AdhE, the recombinant protein was purified. The purified AdhE exhibited high enzymatic activity attributed to aldehyde dehydrogenase (11.0+/-0.3U/mg) and low alcohol dehydrogenase activity (2.6+/-0.2U/mg). Analysis of adhE homologous expression in T. ethanolicus showed that AdhE affected ethanol production.