bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethanol Disrupts Carbamylcholine‐Stimulated Release of Arachidonic Acid from Chinese Hamster Ovary Cells Expressing Different Subtypes of Human Muscarinic Receptor
Authors: Stair Susannah M. , May Lisa G. , Puhl Henry L , Phelps Scott H. , Williams Carol L. , Aronstam Robert S.
Published: May 2006

Ethanol disrupts signal transduction mediated by a variety of G‐protein coupled receptors. We examined the effects of ethanol on arachidonic acid release mediated by muscarinic acetylcholine receptors. Chinese hamster ovary (CHO) cells transfected with the different subtypes of human muscarinic receptors (M1 to M5) were incubated with [3H]arachidonic acid ([3H]AA) for 18 hr, washed, and exposed to the cholinergic agonist carbamylcholine for 15 min. Carbamylcholine induced [3H]AA release from CHO cells expressing M1, M3, or M5, but not M2 or M4, muscarinic receptors. Dose response curves revealed that carbamylcholine stimulated [3H]AA release by up to 12‐fold with an EC50 of ∼0.4 μM; maximal responses were obtained with 10 μM carbamylcholine. Exposure of M1‐, M3‐, or M5‐expressing cells to ethanol for 5 min before stimulating with carbamylcholine reduced [3H]AA release by 40 to 65%; 50% of the maximal inhibition was obtained with an ethanol concentration of 30 to 50 mM. Ethanol did not affect basal [3H]AA release measured in the absence of carbamylcholine. Dose response curves suggest that ethanol acts as a noncompetitive inhibitor of muscarinic receptor‐induced [3H]AA release insofar as maximal [3H]AA release was depressed in the presence of ethanol with no apparent change in the EC50 for stimulation by carbamylcholine. Exposure of CHO cells to 38 mM ethanol for 48 hr increased [3H]AA release induced by carbamylcholine without affecting basal [3H]AA release or altering the EC50 for carbamylcholine. These results indicate that ethanol acutely inhibits muscarinic receptor signaling through the arachidonic acid pathway in a noncompetitive manner, but chronically enhances muscarinic signaling through the same pathway.
Pretreatment with Isradipine, a Calcium‐Channel Blocker, Does Not Attenuate the Acute Behavioral Effects of Ethanol in Humans
Authors: Rush Craig R. , Pazzaglia Peggy J.
Published: May 2006

The acute subject‐rated, performance‐impairing, and physiological effects of ethanol (0, 0.5, and 1 g/kg) were examined after pretreatment with isradipine (0, 5, and 10 mg) in nine healthy volunteers. Volunteers received 1 of the 9 ethanol‐isradipine combinations during each of nine experimental sessions. Ethanol alone produced prototypical subject‐rated drug effects (e.g., increased ratings of “Drunk,”“Good effects,” and “Like drug”) and impaired performance. Isradipine alone also produced significant subject‐rated drug effects (e.g., increased ratings of “Drug effect,”“Bad effects,”“High,” and “Stimulated”), but did not impair performance. Isradipine pretreatment generally did not significantly alter the subject‐rated or performance‐impairing effects of ethanol. Isradipine alone, but not ethanol alone, significantly decreased systolic and diastolic blood pressure. The ethanol‐isradipine combinations generally produced significantly greater decreases in blood pressure than were observed with isradipine alone. Breath‐alcohol levels were significantly lower after isradipine pretreatment, which suggests isradipine altered the bioavailability of ethanol. The present findings extend previous studies with humans that examined the behavioral effects of ethanol after pretreatment with other calcium‐channel blockers, including nifedipine, nimodipine, and verapamil. Whereas the available studies suggest that calcium‐channel blockers would not be useful pharmacological adjuncts in the management of ethanol abuse, more research is needed. Future studies should use self‐administration and drug discrimination procedures adapted for use with humans to determine if calcium‐channel blockers can attenuate any of the behavioral effects of ethanol.
Modulation of the Insulin‐Like Growth Factor System by Chronic Alcohol Feeding
Authors: Lang Charles H. , Fan Jie , Lipton Brian P. , Potter Barry J. , McDonough Kathleen H.
Published: May 2006

Insulin‐like growth factor (IGF)‐I is a potent anabolic agent that plays an important role in regulating muscle protein balance. Alterations in one or more of the various components of the IGF system may be in part responsible for the muscle wasting that accompanies chronic alcohol consumption. The purpose of the present study was to characterize changes in the growth hormone‐IGF axis produced by chronic alcohol consumption in rats. After 8 weeks of alcohol feeding, the IGF‐I concentration was decreased in plasma (31%) as well as in the liver and skeletal muscle (40–50%), compared with pair‐fed control animals. In addition, alcohol consumption decreased IGF‐I mRNA abundance in liver and muscle (∼50%). IGF‐I content in duodenum and kidney, however, was not altered by alcohol feeding. Concomitantly, the relative concentration of IGF binding protein (IG‐FBP)‐1 was increased in plasma, liver, and muscle of alcohol‐fed rats, compared with control values. In contrast, no changes in the plasma concentrations of IGFBP‐2, ‐3, or ‐4 were detected in alcohol‐fed rats at this time point. Previous studies have indicated that elevations in glucocorticoids or decreases in insulin or growth hormone might be responsible for the decrease in IGF‐I and/or the increase in IGFBP‐1 in other catabolic conditions. However, there was no difference in the plasma concentrations of these hormones between alcohol‐fed and control animals in this study. These data indicate that chronic alcohol feeding in rats decreases IGF‐I and increases IGFBP‐1 in the circulation and in skeletal muscle and that these changes appear to be independent of changes in classical hormonal regulators of the IGF system. The observed alterations in the IGF system are consistent with a reduction in the anabolic actions of IGF‐I induced by chronic alcohol consumption.
Ethanol Transcriptionally Upregulates t‐PA and u‐PA Gene Expression in Cultured Human Endothelial Cells
Authors: Grenett Hernan E. , Aikens Michael L. , Torres Jose A. , Demissie Sossiena , Tabengwa Edlue M. , Davis Glenda C. , Booyse Francois M.
Published: May 2006

Epidemiological studies have suggested that moderate alcohol consumption reduces the risk of cardiovascular mortality. This cardio‐protective benefit may be mediated, in part, by promoting fibrinolysis through changes in fibrinolytic components and/or activity, resulting in the decreased risk for thrombosis, coronary artery disease, and eventual myocardial infarction. Endothelial cells (ECs) play a pivotal role in maintaining normal hemostasis by regulating fibrinolysis through the synthesis of plasminogen activators (PAS), tissue‐type plasminogen activator (t‐PA), and urokinase‐type plasminogen activator (u‐PA). The studies described herein were conducted to determine whether a single brief preincubation (1 hr, 37°C) of cultured human umbilical vein ECs (HUVECs) with low ethanol (0.1%, v/v), will upregulate t‐PA and/or u‐PA gene expression at the transcriptional level, using a combination of nuclear transcription run‐on assays and transient transfections of cultured HUVECs with the pPA/luc promoter constructs. Nuclear run‐on assays showed ∼2‐ to 3‐fold and ∼6‐ to 7‐fold increase in the transcription of new t‐PA and u‐PA mRNAs, respectively. In addition, transient transfections of cultured HUVECs with the pt‐PA363/luc and pu‐PA236/luc promoter constructs, using lipofectamine, demonstrated ∼4‐ to 6‐fold and ∼6‐ to 9‐fold increase in luciferase activity for t‐PA and U‐PA, respectively. These combined results demonstrate that low ethanol transcription‐ally upregulates both t‐PA and U‐PA gene expression in cultured HUVECs and provides a molecular basis for the ethanol‐induced increase in EC‐mediated fibrinolytic activity that may underlie and contribute, in part, to the cardioprotective benefit associated with moderate alcohol consumption.
Quantitative Microdialysis of Ethanol in Rat Striatum
Authors: Gonzales Rueben A. , McNabb JoCarol , Yim Hyeon Joo , Ripley Tamzin , Bungay Peter M.
Published: May 2006

We have applied a steady‐state theory of microdialysis to characterize the diffusion of ethanol through a microdialysis membrane and through rat striatum. Quantitative characterization required measurement of in vitro and in vivo extraction fractions for ethanol and determination of the clearance of ethanol from brain tissue during steady‐state perfusion through a microdialysis probe. Extraction fraction of ethanol was determined in vitro by perfusing a known concentration of ethanol through probes immersed in water at 37°C with stirring. The in vitro extraction fraction yielded a probe permeability value of 0.046 ± 0.004 cm/min that is comparable with an estimate from published measurements for similar dialysis membranes. The in vivo extraction fraction was determined for probes placed in the striatum. Clearance of ethanol and a brain slice concentration profile of ethanol were determined by measurement of the amount of ethanol remaining in the brain tissue during steady‐state perfusion of the probe. Steady state was achieved within 10 min after beginning the ethanol perfusion in vivo, and the extraction fraction was not altered by sedation of the rat with pentobarbital. The tissue concentration profile was symmetrical around the probe track, and ethanol was detected 1 mm from the probe. The experimental clearance rate constant value obtained for ethanol (2.0 ± 0.3 min−1) was higher than that expected for removal solely by loss to the blood. The tissue diffusivity for ethanol, Du derived from the experimental measurements was 1.2 ± 0.2 × 10−5 cm2/sec. This value is greater than expected for interstitial diffusion, suggesting a substantial contribution by transcellular diffusion of ethanol as well. The predicted tissue concentration profile had a higher peak value and did not extend into the tissue (0.5 mm) as much as the experimental profile (1 mm), although there was reasonable agreement between experiment and theory. Our quantitative characterization of the microdialysis behavior of ethanol in brain provides a framework for interpretation of brain microdialysis experiments using ethanol by supplying, inter alia, a means for estimating the ethanol concentration achieved in the tissue volume being sampled by the probe.
Skeletal Muscle Ribonuclease Activities in Chronically Ethanol‐Treated Rats
Authors: Reilly Matthew E. , Erylaz Eda Imren , Amir Abdu , Peters Timothy J. , Preedy Victor R.
Published: May 2006

Alcoholic myopathy occurs in up to two thirds of alcohol misusers and is characterized by selective atrophy of type II (anaerobic, fast‐twitch) fibers; type I (aerobic, slow twitch) fibers are relatively unaffected. Both clinical and animal studies have indicated that skeletal muscle RNA content is reduced in response to ethanol exposure, and contributes to impaired protein synthesis. We hypothesized that the reduction in muscle RNA may be due to raised ribonuclease (RNase) activities that enhance RNA catabolism. To test this hypothesis, we measured the total tissue and plasma RNase activities as well as the activities of general (RNase A) and specific or “restriction” RNases (T1L, T2L) in ethanol‐treated rats.

Chronically treated rats were fed a nutritionally complete liquid diet with 35% of calories as ethanol. Weight‐matched controls were pair‐fed with isocaloric glucose. Rats were killed at time‐points up to 6 weeks. For comparative purposes, the effect of acute (24 hr) starvation was also analyzed in a second group of rats relative to a group of control rats allowed free access to food and water over 24 hr.

Results showed that the type II fiber‐predominant plantaris muscle exhibited a significant increase in total RNase, RNase A and RNase T1L activities (increases ranged from +59% to +196%; P‐values between 0.025 and 0.01) concomitant with large falls in RNA and protein content. In contrast, none of the RNase activities measured in the type 1 fiber‐predominant soleus muscles were significantly affected; compositional changes were also smaller in the soleus. This effect was independent of reduced nutrition. In conclusion, the raised total RNase, RNase A and RNase T1L activities may contribute to the type II fiber‐specific reduction in total RNA in chronically ethanol‐treated rats. In turn, this may contribute to the alterations in cellular protein metabolism seen under these treatments.
Fatty Acid ω‐ and (ω‐1)‐Hydroxylation in Experimental Alcoholic Liver Disease: Relationship to Different Dietary Fatty Acids
Authors: Amet Yolande , Adas Fadi , Nanji Amin A.
Published: May 2006

Arachidonic acid concentrations in liver are decreased in response to ethanol administration. In addition, the oxygenated products of arachidonic acid metabolites could affect the severity of alcoholic liver injury. Selective utilization of arachidonic acid by the cyto‐chrome P‐450 system could, in part, account for the decrease in arachidonic acid. To evaluate this pathway further, male Wistar rats were fed different dietary fats: medium chain triglycerides, palm oil, and corn oil or fish oil with either ethanol or isocaloric amounts of dextrose. Histopathology, cytochrome P‐45ME1 (CYP2E1) and cy‐tochrome P‐4504A (CYP4A), and ω‐ and (ω‐1)‐hydroxylation products of lauric and arachidonic acids were evaluated. Ethanol induction of CYP2El was related to the concentration of polyunsaturated fatty acids in the diet; induction of CYP4A by ethanol was seen in all groups. The highest levels of 11‐hydroxy‐lauric acid and 19‐hydroxyarachidonic acid (ω‐1) were seen in rats fed ethanol with palm oil and corn oil. Highly significant correlations were seen between the (ω‐1)‐hydroxylation products and CYP2E1 activity. No correlation was seen between the ω‐hydroxylation products and CYP2E1 activity. In contrast, the levels of ω‐hydroxylation products correlated with CYP4A. The overall results showed a significant increase in (ω‐1)‐hydroxylation products in rats fed diets containing significant amounts of linoleic acid (i.e., palm oil and corn oil).
Chronic and Acute Prenatal and Postnatal Ethanol Exposure on Lymphocyte Subsets from Offspring Thymic, Splenic, and Intestinal Intraepithelial Sources
Authors: Basham Karen B. , Whitmore Sarah P. , Adcock Audrey F. , Basta Patricia V.
Published: May 2006

The overall objective of this study was to analyze the effects of a combined prenatal and postnatal (entire gestational human chronic drinking model) ethanol exposure on T‐cell development in mice. Specifically, this study evaluated the effects of chronic exposure to prenatal ethanol on lymphocyte makeup and proliferative capabilities of postnatal offspring's (4 and 12 weeks) peripheral lymphoid tissues. Chronic exposure regimens were conducted over the entire gestational period and through postnatal day 14 or 21. Thymus, spleen, and intestinal intraepithelial lymphocytes were harvested and analyzed by flow cytometry for percentages of T‐cell subsets. Splenic lymphocytes were also analyzed for their ability to proliferate in response to a T‐cell mitogen. Limited effects of chronic ethanol exposure were seen.
Further Evidence That the Central Nucleus of the Amygdala Is Associated with the Ethanol‐Induced Locomotor Response
Authors: Demarest Kristin , Hitzemann Barbara , Mahjubi Elham , McCaughran James , Hitzemann Robert
Published: May 2006

The effect of ethanol on the number of Fos‐like immunoreactive (Fos‐li) neurons was previously studied in the C57BUW (B6) and DBA/2J (D2) inbred mouse strains (Hitzemann and Hitzemann, Alcohol. Clin. Exp. Res. 21:1497–1507, 1997). The data obtained suggested that the locomotor activation response to ethanol found in the D2 but not the B6 strain was associated with an increase in the number of Fos‐li neurons (a putative measure of synaptic activity) in the central nucleus of the amygdala (CeA), but not in other brain regions, including the basal ganglia. The current study was performed to obtain data supporting a role for the CeA in the locomotor response. B6D2 F2 intercross animals were phenotyped for their locomotor response to ethanol (1.5 g/kg). The animals from the extreme phenotypes (> 1 SD from the mean) were denoted as very high and very low activity (HH, LL) and differed in their ethanol response by >9,000 cm/15 min (baseline activity was similar in both phenotypes: 5,500 cm/15 min). These extremes especially differed from the parental strains in that the LL group showed a significant ethanol‐induced inhibition of activity. After 2 weeks, HH and LL animals were rechallenged with 1.5 g/kg of ethanol or saline and the number of Fos‐li neurons determined 1 hr later. In the HH group, ethanol increased the number of Fos‐li neurons >600%, whereas in the LL group the increase was 170% (difference: p < 0.001). The increase in the HH group was principally located in the GABA neuron‐rich lateral aspect of the CeA and not in the medial posterior‐ventral division or the caps division. No significant difference was found between groups in the Fos response for the basolateral or lateral amygdala. Other brain regions were also examined, including the basal ganglia, the hippocampus (CA1, CA3, and dentate gyms), the bed nucleus of the stria terminalis, and several cortical regions. In some regions (e.g., the bed nucleus), a significant ethanol effect was detected, but it did not differentiate the HH and LL groups. Overall, the data obtained further argue that the CeA has an important role in regulating the acute locomotor response to ethanol.
Ethanol Feeding Impairs Innate Immunity and Alters the Expression of Th1‐ and Th2‐Phenotype Cytokines in Murine Klebsiella Pneumonia
Authors: Zisman David A. , Strieter Robert M. , Kunkel Steven L. , Tsai Wan C. , Wilkowski Jodi M. , Bucknell Kathy A. , Standiford Theodore J.
Published: May 2006

The prolonged and excessive consumption of alcohol has been shown to predispose the host to a variety of infectious complications, which may be due, in part, to the inability to produce important activating cytokines. In this study, we assessed the effect of chronic alcohol ingestion on bacterial clearance, survival, and cytokine mRNA and protein expression in mice with Klebsiella pneumonia. Two‐week ethanol feeding resulted in substantial impairment in the clearance of K. pneumoniae and decreased survival, compared with CD‐1 mice receiving an isocaloric diet without ethanol. No differences were noted between control and ethanol groups in the total numbers or percent of bronchoalveolar lavage fluid neutrophils or macrophages at 24 and 48 hr post‐intratracheal K. pneumoniae. Importantly, the lungs of alcohol‐fed mice with Klebsiella pneumonia displayed a decrease or delay in the expression of interleukin (IL)‐12 p35 and p40 mRNA and interferon‐γ mRNA, respectively, as well as reduced IL‐12 and interferon‐γ protein levels, compared with controls. Conversely, a time‐dependent increase in lung IL‐10 mRNA and protein was noted in ethanol‐fed animals, compared with control animals challenged with K. pneumoniae. In summary, our studies indicate that ethanol ingestion results in a profound suppression of lung bacterial clearance and decreased survival in Klebsiella pneumonia, which occurs in association with a shift in the balance of lung cytokine mRNA and protein expression favoring Th2‐ rather than Th1‐phenotype cytokines.
Reversal of Chronic Ethanol‐Induced Testosterone Suppression in Peripubertal Male Rats by Opiate Blockade
Authors: Emanuele N. V. , LaPaglia N. , Steiner J. , Kirsteins L. , Emanuele M. A.
Published: May 2006

Teenage drinking continues to be a significant problem in the US., as well as abroad. We have previously demonstrated that opiate blockade with naltrexone, a drug currently used in patients to diminish alcohol craving, prevented the fall in serum testosterone seen after acute ethanol (EtOH) exposure in young, peripubertal male rats. To follow‐up on this reversal, a series of experiments was performed to determine if naltrexone would also prevent the testosterone suppression caused by chronic EtOH exposure. Peripubertal rats either 45 days old (mid‐pubertal) or 55 days old (late pubertal) were fed an EtOH‐containing liquid diet or pair‐fed control diet for 14 days. Each animal was implanted with either a naltrexone containing or placebo pellet before starting the liquid diet. In each age group, EtOH alone significantly suppressed testosterone, whereas naltrexone prevented this fall, although it had no effect alone. Serum luteinizing hormone was also suppressed by EtOH; however, naltrexone did not abrogate this fall. In the 45‐day‐old animals, β‐luteinizing hormone mRNA levels rose significantly in the EtOH group, but not when naltrexone was coadministered with EtOH. There was no change in hypothalamic luteinizing hormone releasing hormone (LHRH) mRNA, pro‐LHRH, or LHRH in any group at either age. Thus, naltrexone is able to partially prevent the EtOH‐induced suppression of gonadal testosterone of young, adolescent male rats. This effect appears to be mediated directly at gonadal level, because hypothalamic and pituitary hormone changes were minor and nonsignificant.
Voluntary Ethanol Drinking During the First Three Postnatal Weeks in Lines of Rats Selectively Bred for Divergent Ethanol Preference
Authors: McKinzie D.L. , Cox R. , Murphy J.M. , Li T.‐K. , Lumeng L. , McBride W.J.
Published: May 2006

Background: Using a procedure first developed by Hall (1979), we examined ethanol self‐administration in preweanling pups from Wistar rats and in lines of rats selectively bred for divergent ethanol preference (alcohol‐preferring P, alcohol‐nonpreferring NP, high‐alcohol‐drinking HAD‐1 and ‐2, and low‐alcohol‐drinking LAD‐2) to determine if factors contributing to high and low alcohol intakes arc present early in development.

Methods: From postnatal days 5 to 20, nondeprived male and female rat pups received 30 min daily access to either water or a 15% (v/v) ethanol solution. In each daily session, pups were placed in a heated chamber containing Kimwipes soakcd with a water or ethanol solution. Pups were weighed before and after each session, and intake levels were calculated as a percentage of body weight change.

Results: Similar to previous reports, Wistar pups exhibited over a 2‐fold higher level of ethanol ingestion than water on postnatal days 9 through 14, with ethanol intakes approaching 3 g/kg body weight. When the drinking patterns of the selected lines were examincd, only the HAD replicate lines showed a comparable preference for ethanol versus water during the preweanling period. The ethanol consumption of P, NP, and LAD lines was not consistently distinguishable from water intake levels. To reveal whether early ethanol exposure would influence later ethanol drinking behavior, a subset of HAD and LAD rat pups received free‐choice ethanol access upon weaning. Although the divergent ethanol preference between high‐ and low‐alcohol‐drinking lines was evident within the first 4 days of access (>4 g/kg/day for HAD; <2 g/kg/day for LAD). preweanling ethanol exposure did not alter the acquisition or maintenance of ethanol drinking in cither line.

Conclusions: Overall, these results suggest that (a) the enhanced ethanol ingestion observed during the middle portion of the preweanling period is a robust phenomenon and generalizes across nonselected strains of rats, (b) selective breeding for divergent alcohol preference has arrested this age‐specific effect in all hut the HAD lines of rats, and (c) early ethanol exposure does not alter genetic dispositions for later high or low alcohol prefercnce.
Acute Hemodynamic Effects of Ethanol in Conscious Spontaneously Hypertensive and Normotensive Rats
Authors: EI‐Mas Mahmoud M. , Abdel‐Rahman Abdel A.
Published: May 2006

This study investigated the differential hemodynamic effects of small to high doses of ethanol in conscious age‐matched spontaneously hypertensive rats (SHRs) and Wistar Kyoto rats (WKYs). Changes evoked by ethanol (0.25, 0.5, or 1g/kg, iv) or equal volume of saline in mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) were followed for 90 min in the two rat strains. The baseline MAP (163 ± 4 vs. 113 ± 2 mm Hg) of SHRs was significantly (p < 0.05) higher, compared with WKYs due mainly to the presence of an elevated TPR (3.82 ± 0.12 vs. 2.51 ± 0.09 mm Hg/ml/min/100 g, p < 0.05) in SHRs. In both rat strains, all doses of ethanol produced immediate increases in MAP at 1 min, after which the MAP responses varied and depended on the rat strain and dose of ethanol used. In WKYs, 0.25 g/kg ethanol had no effect on MAP, but caused significant decreases in CO and SV and increased HR. Ethanol (0.5 and 1 g/kg) produced a short‐lived (10 min) and dose‐related increase in MAP. The higher dose (1 g/kg) of ethanol elicited significant (p < 0.05) increases in TPR that were counterbalanced by concomitant decreases in CO and SV. In SHRs, the two higher doses (0.5 and 1 g/kg) of ethanol elicited significant (p < 0.05) decreases and increases in MAP, respectively, compared with control (saline‐treated) values. The pressor response to the 1 g/kg dose of ethanol was associated with an increase in TPR that achieved a statistical significance (p < 0.05) at 50 and 80 min after ethanol administration. HR was significantly (p < 0.05) reduced by the two higher doses of ethanol, whereas SV and CO were not changed. Blood ethanol concentrations measured 10, 30, and 60 min after ethanol administration were similar in SHRs and WKYs. These findings suggest that acute administration of ethanol to conscious rats elicits hemodynamic responses that are strain‐and dose‐dependent. In contrast to a short‐lived and dose‐related pressor response in WKYs, ethanol (0.5 and 1 g/kg) elicited opposite and longer lasting effects on MAP (decreases and increases, respectively) in SHRs. In both rat strains, the pressor response to the higher dose of ethanol was associated with an increase in TPR; an effect that was compromised by a concomitant decrease in CO in WKYs but not SHRs.
Effects of Ethanol and Ethanol Withdrawal on Nociception in Rats
Authors: Gatch Michael B. , Lal Harbans
Published: May 2006

The effect of acute and chronic administration of ethanol and ethanol withdrawal on a radiant heat tail‐flick assay of nociception was examined in rats. Acute administration of ethanol (2.0 g/kg, ip) produced peak antinociception (68% of maximum) by 30 min, and effects were gone by 120 min. Cumulative doses of ethanol (0.5–2.0 g/kg, ip) produced dose‐dependent increases in latencies to 49% of maximum. During chronic administration, a liquid diet containing ethanol (6.5%) was given for 10 days. Tail‐flick latencies were measured on day 0 (baseline), day 2, 4, 6, 8, and 10 of chronic ethanol and at 3, 6, 12, and 36 hr after removal of ethanol. To test for behavioral tolerance, both between‐ and within‐group designs were used. In both between‐ and within‐group experiments, the antinociceptive effects of chronic ethanol peaked by day 4 of exposure to the liquid diet, and tolerance developed by day 10. When the liquid diet was removed, hyperalgesia was detected at 6 and 12 hr after withdrawal, and was gone by 36 hr after withdrawal. When cumulative doses of ethanol (0.5–2.0 g/kg) were administered starting 12 hr after withdrawal, ethanol (0.5 g/kg) fully reversed the hyperalgesia induced by ethanol withdrawal, even though this dose was without antinociceptive effect in the absence of withdrawal. Higher doses of ethanol during ethanol withdrawal did not increase tail‐flick latencies over baseline. In summary: (1) ethanol produces antinociception when administered acutely or chronically; (2) tolerance to the antinociceptive effects develops during chronic administration; (3) ethanol withdrawal induced hyperalgesia, which was reversed by ethanol; and (4) repeated testing did not produce behavioral tolerance.
Ethanol Elevates c‐Myc Levels in Cultured Mouse Preimplantation Embryos
Authors: Leach Richard E. , Rout Ujjwal K. , Schultz Jeffrey F. , Saunders Dwight E. , Armant D. Randall
Published: May 2006

A brief exposure to ethanol accelerates the rate of early mouse embryonic development in vitro, increasing blastocyst formation, trophohlast outgrowth, and implantation rates after embryo transfer. The physiological effects of ethanol during preimplantation development are associated with rapid changes in gene expression and apparently arise from the ability of ethanol to elevate cytoplasmic free Ca2+ and alter cellular signaling pathways. The purpose of this study was to examine whether the abundance of c‐Myc, a transcription factor that promotes cell proliferation and is required for blastocyst development, is upregulated in mouse blastocysts challenged with ethanol. After exposure of mouse blastocysts to 0.1% (17.5 mM) ethanol, we determined the levels of: 1) c‐Myc mRNA, using reverse transcription and the polymerase chain reaction; and 2) c‐Myc protein levels, using specific monoclonal antibodies. Within 10 min of exposure to ethanol, the relative abundance of c‐Myc mRNA increased 6‐fold, then rapidly returned to baseline levels within 1 hr. As expected, elevation of c‐Myc mRNA by ethanol was attenuated in embryos that were first treated with the intracellular Ca2+ chelator, BAPTA‐AM. Western blot analysis of solubilized embryos revealed that c‐Myc mRNA was translated into a single 62‐kD protein that increased in intensity 30 min after treatment with ethanol. Immunocytochemical staining demonstrated that c‐Myc was localized exclusively in nuclei and that staining intensity increased significantly after 10 min. Peak levels of c‐Myc protein were found 30 min after ethanol exposure and persisted for at least 2 hr. The c‐myc proto‐oncogenc seems to be an immediate early response gene for ethanol that may regulate the transcription of other genes that influence early embryogenesis and growth.
Ethanol Suppression of the Functional State of Polymorphonuclear Leukocytes Obtained From Uninfected and Simian Immunodeficiency Virus Infected Rhesus Macaques
Authors: Stoltz David A. , Zhang Ping , Nelson Steve , Bohm Rudolf P. , Murphey‐Corb Michael , Bagby Gregory J.
Published: May 2006

Background

: Human immunodeficiency virus (HIV) infection and alcohol abuse frequently coexist in the host and are known to suppress individually the host response to a variety of opportunistic infections.

Methods

: This study examined the effects of in vitro ethanol exposure on several functions of polymorphonuclear leukocytes (PMNs) that were obtained from uninfected and simian immunodeficiency virus (SIV)‐infected rhesus macaques, at the asymptomatic and terminal stages of infection.

Results

: The PMNs obtained from rhesus macaques at both the asymptomatic and terminal stage of SIV disease had elevated phagocytic activity and increased CD11b expression compared with PMNs from uninfected animals. In vitro 100 mM ethanol suppressed phagocytosis and CD1lb adhesion molecule expression by PMNs, regardless of the stage of SIV infection. Treatment of PMNs with granulocyte colony‐stimulating factor (G‐CSF) attenuated the inhibitory effect seen with prior ethanol exposure.

Conclusions

: Thcsc data demonstrate that the functional state of PMNs from uninfected as well as SIV‐infected rhesus macaques is impaired by direct exposure to intoxicating concentrations of ethanol and that this effect can be attenuated by G‐CSF. If alcohol intoxication similarly suppressed PMN function in vivo. it would further increase susceptibility of these hosts to secondary infections. Furthermore, G‐CSF may be useful in overcoming the suppressive effects of ethanol on PMN function in such patients.
Roles of FMO and CYP450 in the Metabolism in Human Liver Microsomes of S‐Methyl‐N, N‐Diethyldithiocarbamate, a Disulfiram Metabolite
Authors: Pike M. Gennett , Martin Yvette N. , Mays Dennis C. , Benson Linda M. , Naylor Stephen , Lipsky James J.
Published: May 2006

Background: The conversion of S‐methyl‐N,N‐diethyldithiocarbamate (MeDDC) to MeDDC sulfine is the first step after methylation in the metabolic pathway of disulfiram, an alcohol deterrent, to its ultimate active metabolite. Various isoforms of CYP450 have recently been shown to catalyze this reaction, but the involvement of flavin monooxygenase (FMO) in this metabolism in humans has not been evaluated. In this study we examined the ability of recombinant human FM03 in insect microsomes to metabolize MeDDC, and investigated the relative roles of FMO and CYP450 in the metabolism of MeDDC in human liver microsomes.

Methods: HPLC‐mass spectrometry was used to identify the products of MeDDC formed by human liver microsomes and by recombinant human FM03. MeDDC metabolism in human liver microsomes was studied by using either heat inactivation to inhibit FMO, or N‐benzylimidazole (NBI) or antibodies to the CYP450 NADPH reductase to inhibit CYP450.

Results: We confirmed by HPLC‐mass spectrometry that MeDDC sulfine was the major product of MeDDC formed by human liver microsomes and by FM03. Recombinant FM03 was an efficient catalyst for the formation of MeDDC sulfine (5.3 ± 0.2 nmol/min/mg, mean ± SEM, n = 6). Inhibition studies showed MeDDC was metabolized primarily by CYP450 in human liver microsomes at pH 7.4, with a 10% contribution from FMO (total microsomal activity 3.1 ± 0.2, n= 17). In the course of this work, methyl p‐tolyl sulfide (MTS), sulfoxidation of which is used by some investigators as a specific probe for FMO activity, was found to be a substrate for both FMO and CYP450 in human liver microsomes.

Conclusions: Our results prove that MeDDC sulfine is the major product of MeDDC oxidation in human liver microsomes, MeDDC is a good substrate for human FM03, and MeDDC is metabolized in human liver microsomes primarily by CYP450. We also showed that use of MTS sulfoxidation as an indicator of FMO activity in microsomes is valid only in the presence of a CYP450 inhibitor, such as NBI.
Alcohol Increases Commission Error Rates for a Continuous Performance Test
Authors: Dougherty Donald M. , Moeller F. Gerard , Steinberg Joel L. , Marsh Dawn M. , Hines Stella E. , Bjork James M.
Published: May 2006

Background: Studying the effects of alcohol on Continuous Performance Test (CPT) performance was of interest for two reasons, i.e., (1) perhaps because of the ease of the task used in previous experiments, alcohol has not been found to impair performance, and (2) CPT commission errors (described below) have been related to impulsive behavior.

Methods: In this study, the CPT featured both an Immediate Memory Task (IMT) and a more difficult Delayed Memory Task (DMT). We compared the performance of 18 subjects under both alcohol and placebo conditions, using a within‐subject design. Both the IMT (0.5‐sec delay) and the DMT (3.5‐sec delay, with distracter stimuli at 0.5‐sec intervals) required the subject to respond if a briefly displayed number was identical to the one presented before it. Stimuli included target (identical match), catch (4 of 5 digits matched), and novel (random number) stimuli. On 2 separate days, subjects performed between administrations of three hourly placebo drinks or three hourly drinks containing 0.20 g/kg of alcohol (producing peak breath alcohol concentrations of approximately 0.035%).

Results: The main finding was that alcohol consumption increased responses to catch stimuli (i.e., commission errors) in the DMT. In contrast, performance in the IMT (the easier task) was unaffected by alcohol. Commission errors measured during peak breath alcohol concentrations were significantly correlated with scores on the Barratt Impulsivity Scale for both the IMT and DMT. Discriminability (A') between target and catch stimuli was reduced by alcohol for the DMT only.

Conclusions: These data indicate that even small amounts of alcohol can produce measurable changes in CPT performance parameters if the task is of sufficient difficulty and that commission errors can be increased by alcohol consumption.
Effects of Ethanol on Intestinal Absorption of Drugs: In Situ Studies with Ciprofloxacin Analogs in Acute and Chronic Alcohol‐Fed Rats
Authors: Ferrando R. , Ganigues T. M. , Bermejo M. V. , Martin‐Algarra R. , Merino V. , Polache A.
Published: May 2006

Background: Previous work from our laboratory on the effect, in rats, of chronic ethanol intake on the intestinal absorption of ciprofloxacin analogs suggested an increased polarity of the lipoidal membrane constituents without effects on the aqueous environment. The aim of the present study was to investigate the influence of acute ethanol intake on the absorption of the same series of compounds.

Methods: The effects of in situ ethanol exposure on intestinal absorption were determined in rats fed either a standard liquid diet or a 5% (w/v) ethanol‐containing liquid diet. Acute intestinal exposure to 5% (w/v) ethanol was performed in situ in each feeding group. The biophysical absorption model was used to establish correlations between the actual absorption rate constants, and the lipophilicity indexes, for each group of rats.

Results: Acute exposure to ethanol produces an increase only in the absorption of hydrophilic homologs in both control and chronic ethanol fed groups. This suggests the absence of homeoviscous adaptation of the intestinal membrane. The biophysical model used allows us to discriminate between the effects of acute and chronic ethanol treatment on the intestinal membrane.

Conclusions: These results suggest that in contrast to previous reports chronic ethanol treatment increases membrane polarity and acute alcohol intake appears to modify membrane fluidity.
Is Heavy Alcohol Consumption an Attributable Factor for Cancer‐Related Deaths Among Japanese Men?
Authors: Makimoto Kiyoko , Oda Hatsue , Higuchi Susumu
Published: May 2006

Background: Over the past four decades, per capita alcohol consumption in Japan has increased 4‐fold. Age‐adjusted cirrhosis mortality rates for men have also increased, whereas the rates for women have declined gradually. This widening difference in mortality could be due to a decreasing prevalence of viral hepatitis infection for both sexes and to differences in alcohol consumption between the sexes. Difficulties in estimating the impact of increased alcohol consumption on mortality rates in Japan also arise from changes in the prevalence of non‐alcohol‐related risk factors.

Methods: To measure the relative contribution of alcohol to death from cirrhosis, liver cancer, esophageal cancer, and head and neck cancer among Japanese men, we used the mortality rate for Japanese women as the standard because alcohol consumption for women has been low. We used published vital statistics data from 1992 to 1996 to calculate the attributable risk percent (ARP) in 5‐year cohorts of Japanese men age 20 and older.

Results: Among Japanese men, heavy alcohol consumption accounted for 70.7% of deaths due to cirrhosis, 76.8% of liver cancer deaths, 88.5% of esophageal cancer deaths, and 87.4% of head and neck cancer deaths. When we examined ARPs by age group, ARPs for these four diseases were approximately 80% in the middle age groups. However, for older groups, the ARPs for cirrhosis and liver cancer were much lower than those for esophageal cancer and head and neck cancer. The prevalence of previous hepatitis C virus infection, considered to be the major cause of cirrhosis and liver cancer, increased with age.

Conclusions: The results support previous epidemiologic studies conducted in Japan. Heavy alcohol consumption is a major public health problem among younger Japanese men, accounting for approximately 80% of the deaths for the four diseases examined.
Efficacy of Nicotine Patch in Smokers With a History of Alcoholism
Authors: Hughes John R. , Novy Pamela , Hatsukami Dorothy K. , Jensen Joni , Callas Peter W.
Published: May 2006

Background: Smokers with a history of alcohol dependence may have more difficulty quitting, might relapse to alcohol use, and might especially benefit from nicotine replacement therapy for smoking cessation.

Methods: One hundred fifteen smokers with a history of alcohol dependence (median of 5 years previously) were randomly assigned to either a 21‐mg nicotine patch or placebo in a trial designed to be as similar as possible to a prior study that examined smokers with no history of alcoholism. Both studies were of heavy smokers with similar levels of nicotine dependence; thus, any differences in trials would be due to a history of alcohol problems per se.

Results: In the current trial, adjusted prolonged smoking abstinence in those with a history of alcohol dependence was higher in the active than the placebo group at end‐of‐treatment (28% vs. 11%; odds ratio, 3.2;p= 0.04) and at 6‐month follow‐up (24% vs. 6%; odds ratio, 4.9;p= 0.02). Among subjects not lost to follow‐up, none reported drinking problems or increases in craving for alcohol. Smoking abstinence was not lower and the odds ratio for nicotine patch therapy was not greater in smokers with a history of alcohol dependence than in smokers with no such history.

Conclusions: Heavy smokers with a history of alcoholism benefit from nicotine patch treatment. A history of alcohol problems after a period of stable sobriety does not appear to influence smoking outcomes or response to nicotine replacement. Although no smokers relapsed to alcohol use, a trial that follows up all subjects is needed to verify this.
Energy Production Risks: What Perspective Should We Take?
Authors: Whipple Chris
Published: May 2006

The controversy over energy‐production risks is in part due to uncertainties and disagreements over the specification of these systems and their characteristics and in part due to the lack of a solid conceptual framework for comparisons between qualitatively different types of risks. The difficulties in specifying energy risks arise primarily from the necessity of using oversimplified descriptions of energy systems and their effects. The major simplifications include the use of marginal analysis (even when inappropriate), the omission of indirect risks, and the incorrect specification of the systems to be analyzed. Comparisons between qualitatively different risks are hampered by the lack of a solid basis for treating occupational risks relative to public risks, catastrophic risks versus chronic risks, and risks distributed differently in time. The difficult problems encountered when social values relating to risk change rapidly lead to delay and indecision. The choice of analytical simplifications and the specification of values systems for energy analysis are best made by considering the context and application of the analysis.
A Method for Projecting Age‐Specific Mortality Rates for Certain Causes of Death
Authors: Leggett Richard W. , Crawford Douglas J.
Published: May 2006

A method is presented for projecting mortality rates for certain causes on the basis of observed rates during past years. This method arose from a study of trends in age‐specific mortality rates for respiratory cancers, and for heuristic purposes it is shown how the method can be developed from certain theories of cancer induction. However, the method is applicable in the more common situation in which the underlying physical processes cannot be modeled with any confidence but the mortality rates are approximable over short time intervals by functions of the form a exp (bt), where b may vary in a continuous, predictable fashion as the time interval is varied. It appears from applications to historical data that this projection method is in some cases a substantial improvement over conventional curve‐fitting methods and often uncovers trends which are not apparent from observed data.
The Saint Petersburg Game: An Exposition of the Classical Treatment
Authors: Ruckle William H.
Published: May 2006

An early attempt to measure risk was the 1738 paper of Bernoulli in which he describes the well‐known Saint Petersburg paradox. Subsequent writers have considered this game to draw conclusions about the nature of risk or to test newly devised risk models. We analyze the paradox, evaluate various theories which have been advanced to resolve it, and briefly examine the implications of these theories on the wider area of risk analysis.
Car Occupant Life Expectancy: Car Mass and Seat Belt Effects
Authors: Evans Leonard , Blumenfeld Dennis E.
Published: May 2006

Average human life expectancies for the U.S. resident population are calculated using tabulated population and survival rate data. These life expectancies are recalculated assuming elimination of various types of motor vehicle fatalities using Fatal Accident Reporting System (FARS) data. The differences between the original and recalculated values provide estimates of life expectancy reductions due to the motor vehicle fatalities. These estimates are combined with prior work relating the likelihood of an occupant fatality to car mass, so that reductions in life expectancy are determined as a function of car mass. The estimates of life expectancy reductions are also used to determine the effect of seat belt use on life expectancy. The estimates, which are based on data for 1978, assume that survival rates remain unchanged. Estimates of the changes in life expectancy associated with switching from a large (1800 kg) car to a small (900 kg) car, and switching from not using to using a seat belt are presented as functions of the age at which an individual makes the switch.
Some Problems in Determining Risks from Cancer
Authors: Totter John R.
Published: May 2006

Age‐adjusted cancer mortality data (1964) were examined for evidence of independence. Indications were found that substitution of one cancer for another is a common occurrence. The data were interpreted as supportive of the view that natural selection for resistance to cancer in general has occurred with many resistance‐related genes common to prevention of cancer of several sites. Consequently, the comparison of age‐adjusted incidence or mortality rates of cancer of single sites alone does not provide a satisfactory estimate of the magnitude of an “environmentally induced” cancer risk. It is necessary to examine all causes of death to find indications of a real life‐shortening episode.
Low Probability Accidents
Authors: Kunreuther Howard , Linnerooth Joanne
Published: May 2006

Experts frequently differ on their estimates of risk associated with accidents that have a low probability of occurrence. Those who stand to benefit from siting a new facility often perceive it as acceptably safe, using expert opinion to defend their argument. Potential losers find data to suggest that the new technology is too hazardous. This paper contrasts the role of risk assessments of low probability events in siting Liquified Natural Gas (LNG) terminals in the United States and the Federal Republic of Germany. In both cases the decision process was a rather lengthy one due to conflicts between interested stakeholders. The paper discusses the potential of compensation and insurance as policy tools for facilitating negotiation. Four criteria for improving the siting process in any country are also outlined.
Probabilistic Risk Analyses: NRC Programs and Perspectives
Authors: Bernero Robert M.
Published: May 2006

The historical basis and more recent activities and products of probabilistic risk analysis (PRA) in the Atomic Energy Commission and Nuclear Regulatory Commission (NRC) are reviewed. Current NRC program activities and objectives are described. The author's opinions on the best uses of PRA are presented.
Health Risks and Air Pollution — Error Analysis for a Cross‐Sectional Mortality Study
Authors: Pickles J. H.
Published: May 2006

An attempt is made to analyze in quantitative terms the uncertainties in multiple regression estimates of the effects of air pollution on death rates. A range of factors—statistical fluctuations in numbers of deaths, differences in local age distribution, differences in smoking habits, errors in estimated pollution levels, migration, and variability of the characterization of socioeconomic effects—are assessed as potential sources of error. Both the precision and the robustness of the regression calculation are shown to be poor. Examples and illustrative calculations are given based on a study of U. K. death rates around the 1971 Census.