bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Assessment of the Ability of Oral Ethanol to Function as a Reinforcing Stimulus
Authors: Samson Herman H. , Czachowski Cristine L. , Slawecki Craig J 
Published: April 2006

Background: In animal studies, the ability of ethanol to function as a reinforcer has been described as weak to moderate. This is in contrast with the human condition, where the consumption of alcoholic beverages can result in a variety of unwanted drinking behaviors. However, when the ethanol self‐administration pattern is examined, animal studies over the last several years indicate that the ability of ethanol presentation to maintain behavior may be greater than originally assumed.Methods: We reevaluated the ability of ethanol to function as a reinforcing stimulus in two paradigms by using an analysis of drinking bout characteristics. Data from previous studies that employed two self‐administration models were analyzed. With the “dipper” model, small amounts of ethanol are presented after each completion of a response requirement; with the “sipper” model, the animal is allowed access to a drinking tube that contains ethanol for an extended period after completing a single response requirement. For both models, the consumption pattern could be characterized as occurring in a bout. Each drinking bout was divided into runs within the bout, and run rates and size were analyzed. As well, in the sipper model, the data on response requirement size were reviewed to demonstrate the ability of ethanol presentation to maintain high levels of responding in this model.Results: From this assessment, we suggest that ethanol presentation in non‐food‐ or non‐water‐restricted rats is as reinforcing as many other stimuli generally considered to be strong reinforcers (i.e., food in food‐restricted rats). Using run size, we demonstrated that intake control appears to be regulated by shifts in run size during the bout and not run rate.Conclusions: Assessment of the pattern of ethanol consummatory bouts and the behaviors that precede them is critical in understanding how ethanol functions as a reinforcer. By using a drinking pattern analysis, the shifts in the momentary salience of the ethanol stimulus can be evaluated in these animal models. In addition, the separation of responding required to gain access to ethanol from consumption of ethanol demonstrated that ethanol presentation in this procedure can be a strong reinforcer for rats.
Reverse Microdialysis of a Dopamine Uptake Inhibitor in the Nucleus Accumbens of Alcohol‐Preferring Rats: Effects on Dialysate Dopamine Levels and Ethanol Intake
Authors: Engleman Eric A. , McBride William J. , Wilber Aaron A. , Shaikh Saame R. , Eha Renee D. , Lumeng Lawrence , Li Ting‐Kai , Murphy James M. 
Published: April 2006

Background: The mesolimbic dopamine (DA) system has been implicated in mediating the reinforcing actions of ethanol (EtOH). This study examines the effects of local perfusion of the DA uptake inhibitor GBR12909 (GBR) on (1) DA levels in the nucleus accumbens (NAc) and (2) EtOH drinking in alcohol‐preferring rats.Methods: Stable drinking of a 15% (v/v) EtOH solution (minimum of 0.75 g/kg body weight) was established in daily 1 hr limited access sessions. Rats were then implanted with bilateral guide cannulae aimed 4 mm above the NAc. After recovery from surgery, concentric microdialysis probes (2 mm dialysis membrane surface) were inserted into the NAc. Most placements were in the shell or overlapping both shell and core. Two days later, the probes were perfused at 1.0 μl/min with artificial cerebral spinal fluid (aCSF) for at least a 90 min washout period followed by collection of five basal samples over 150 min. Rats were then perfused with either aCSF alone or 10, 25, 100, or 200 μM of GBR for 240 min on the first day of microdialysis. During the last 60 min of the drug treatment phase, rats were given their scheduled access to 15% EtOH. All rats were then perfused with aCSF for the last 90 min of the experiment. The following day, the procedure was repeated, but animals that received aCSF on the first day were given a dose of GBR and rats given GBR on the first day received only aCSF.Results: GBR perfusion increased extracellular NAc DA levels dose dependently to more than 800% of basal levels at 100 to 200 μM but failed to alter EtOH intake (p > 0.05, paired t test) at any concentration tested. Moreover, after 100 μM of GBR perfusion had terminated, the extracellular levels of DA in the NAc remained elevated for approximately 24 hr (790% of day 1 basal;p < 0.05). The increase in dialysate DA levels observed during GBR perfusion with 100 μM was significantly greater for EtOH‐experienced rats than for EtOH‐naïve rats [F (7,59) = 14.85, p < 0.0001, analysis of variance, Student‐Newman‐Keuls post hoc test].Conclusions: The results suggest (1) that EtOH drinking experience induces neuroadaptations that increase DA release in the NAc, and (2) that additional elevation in synaptic levels of DA in the NAc does not influence the maintenance of ongoing alcohol drinking under scheduled access conditions in alcohol‐preferring animals.
4.0 T Water Proton T1 Relaxation Times in Normal Human Brain and During Acute Ethanol Intoxication
Authors: Rooney William D. , Lee Jing‐Huei , Li Xin , Wang Gene‐Jack , Franceschi Dinko , Springer Charles S. , Volkow Nora D. 
Published: April 2006

Background: It has been reported that acute ethanol intoxication decreases the brain water proton magnetic resonance T1 values, an effect that has been interpreted to indicate brain dehydration during this condition. Because water macromolecular interactions largely determine tissue water T1, another possible explanation for reduced brain water proton T1 values is that the interaction between water and brain macromolecules is altered by ethanol.Methods: A 4.0 T magnetic resonance imaging (MRI) instrument was used to measure brain water proton T1 relaxation times before, during, and after ethanol intoxication (dose, 0.75 mg/kg) in healthy controls.Results: The T1 relaxation times as assessed with MRI were highly reproducible. The mean, paired ethanol‐induced differences in T1 were −0.004 ± 0.007 sec (mean ± standard deviation) for white matter and 0.010 ± 0.015 sec for internal gray matter structures, neither of which was significant.Conclusions: This reasonably sensitive measurement does not support the view that tissue water content or water macromolecule interactions are significantly altered in the brain during acute alcohol intoxication in otherwise healthy subjects.
Role of Nitric Oxide in Endotoxin‐Induced Hepatic Microvascular Dysfunction in Rats Chronically Fed Ethanol
Authors: Horie Yoshinori , Kimura Hiroyuki , Kato Shinzo , Ohki Eiji , Tamai Hironao , Yamagishi Yoshiyuki , Ishii Hiromasa 
Published: April 2006

Background: Nitric oxide (NO) appears to be involved in the pathogenesis of endotoxin‐induced liver injury. However, little is known about how NO acts on the hepatic microcirculation, especially in alcohol‐fed animals. We examined the roles of NO in endotoxin‐induced hepatic microvascular dysfunction in control and ethanol‐fed rats.Methods: One lobe of the liver was observed with an intravital microscope. Flow velocity of fluorescein isothiocyanate‐labeled erythrocytes in sinusoids was measured with an off‐line velocimeter. Portal pressure and mean arterial pressure also were measured.Results: After administration of endotoxin to control, the flow velocity decreased after 30 min. Portal pressure increased after 45 min. However, in ethanol‐fed rats, both the flow velocity and portal pressure temporarily increased in the early phase. Thereafter, the flow velocity decreased and portal pressure increased. At 30 min after administration of the endotoxin, pretreatment with 10 mg/kg of an NO synthase inhibitor, NG‐monomethyl‐L‐arginine (L‐NMMA), enhanced the endotoxin‐induced decrease in the velocity of erythrocytes in the midzonal region of both control and ethanol‐fed rats. Although 0.5 mg/kg of L‐NMMA enhanced the endotoxin‐induced reduction of erythrocyte velocity in the midzonal region of ethanol‐fed rats, L‐NMMA enhanced the endotoxin‐induced reduction of erythrocyte velocity in the pericentral region of control rats. At 60 min after the endotoxin administration, L‐NMMA did not affect the endotoxin‐induced decrease of erythrocyte velocity in either control or ethanol‐fed rats. Although 10 mg/kg of L‐NMMA increased mean arterial pressure both in control and ethanol‐fed rats, 0.5 mg/kg of L‐NMMA did not change mean arterial pressure in either control or ethanol‐fed rats.Conclusions: These results suggest that NO is involved in endotoxin‐induced hepatic microvascular dysfunction, which may contribute to the sequential liver injury, especially in alcohol‐fed animals.
Effects of CH‐100, a Chinese Herbal Medicine, on Acute Concanavalin A‐Mediated Hepatitis in Control and Alcohol‐Fed Rats
Authors: Batey R. , Cao Q. 
Published: April 2006

Background: Administration of concanavalin A (Con A) leads to acute hepatitis that involves T‐cell activation and inflammatory mediator production in mice and rats. We examined the role of CH‐100, a Chinese herbal medicine previously trialed in human hepatitis C, in the prevention of Con A‐related, T‐cell‐mediated, acute liver injury in rats.Methods: Female Wistar rats were fed 40% ethanol, 2% sucrose, or isocaloric sucrose for 8 weeks. At the same time, these animals were fed either the Chinese herbal medicine CH‐100 (4 tablets/kg body weight/day) or placebo in chow daily. Blood from the tail vein was collected for endotoxin (lipopolysaccharide) assay at 0, 4, and 8 weeks of ethanol consumption. Twenty‐four hours after injection of Con A (20 mg/kg body weight) or phosphate‐buffered saline, blood from the tail vein was collected for alanine aminotransferase and tumor necrosis factor (TNF)‐α assays. Liver‐associated CD4+ T cells were isolated from liver perfusates and then cultured with Con A (5 μg/ml) at 37°C for 24 hr. Supernatants were harvested for TNF‐α assay. The proportion of CD4+ T cells in blood and liver perfusates was measured. Liver samples were collected for histopathological analysis.Results: Lipopolysaccharide levels were significantly reduced in CH‐100‐treated ethanol‐fed rats compared with placebo‐treated rats. After Con A injection, alanine aminotransferase levels were lower at 12 and 24 hr in herb‐treated rats compared with placebo‐treated rats. Furthermore, serum TNF‐α levels were lower in ethanol‐fed rats on herbal treatment. A significant decrease in TNF‐α production by liver‐associated CD4+ T cells in culture was observed in CH‐100‐treated ethanol‐fed rats. CH‐100 treatment was associated with a decreased percentage of CD4+ cells in both blood and liver perfusate in all groups. Herb‐treated rats displayed markedly less hepatic necrosis and a reduced CD4+ T‐cell infiltrate in portal areas than did placebo‐fed rats.Conclusions: The results demonstrate that CH‐100 modified the T‐cell response to Con A injection. The effect was more marked in ethanol‐fed rats, which suggests a possible role for CH‐100 in treating alcoholic liver disease.
Heart Mitochondrial Respiratory Chain Complexes Are Functionally Unaffected in Heavy Ethanol Drinkers Without Cardiomyopathy
Authors: Miró Òscar , Robert Jordi , Casademont Jordi , Alonso Josep R. , Nicolás Josep M. , Fernández‐Solá Joaquim , Urbano‐Márquez Àlvaro , Hoek Jan B. , Cardellach Francesc 
Published: April 2006

Background: Harmful effects of chronic ethanol intake on liver mitochondria have been clearly demonstrated; however, mitochondria from skeletal muscle are preserved, and the effect of ethanol on heart mitochondria remains controversial. We assessed individual enzyme activity of mitochondrial respiratory chain (MRC) complexes and membrane oxidative damage of heart mitochondria in active ethanol drinkers before the development of dilated cardiomyopathy.Patients and Methods: Heart samples were obtained from otherwise healthy organ donor individuals with a sudden death of traumatic or neurological cause in whom hearts could not be used because of absence of matched receptors or size inadequacy. Detailed history of alcohol intake was achieved from the relatives. Citrate synthase activity was spectrophotometrically assayed, as well as absolute (nmol · min−1· mg protein−1) and relative (corrected by citrate synthase) activities of complex I, II, III, and IV of the MRC. Oxidative damage of myocardium membranes was assessed measuring the degree of lipid peroxidation by fluorescence using cis‐parinaric acid as probe.Results: We included 10 ethanol drinkers (age 53 ± 13 years, 100% males, mean lifetime intake of 15.6 ± 7.9 kg ethanol · kg body weight−1) and 12 controls (age 60 ± 10 years, 75% males). Mitochondrial content did not differ between the two groups. Absolute enzyme activities for ethanol drinkers and controls were, respectively, 145 ± 75 and 130 ± 50 for complex I (p= NS); 399 ± 193 and 376 ± 100 for complex II (p= NS); 719 ± 288 and 714 ± 308 for complex III (p= NS); and 475 ± 139 and 570 ± 160 for complex IV (p= NS). After correcting such activities by citrate synthase activity, we failed again to demonstrate differences between ethanol drinkers and controls. Lipid peroxidation of myocardium membranes was similar in both groups.Conclusions: Chronic ethanol drinkers without cardiomyopathy exhibit normal MRC activity in the heart and do not show increased oxidative damage in myocardial membranes.
Integrating Person‐Centered and Variable‐Centered Analyses: Growth Mixture Modeling With Latent Trajectory Classes
Authors: Muthén Bengt , Muthén Linda K. 
Published: April 2006

Background: Many alcohol research questions require methods that take a person‐centered approach because the interest is in finding heterogeneous groups of individuals, such as those who are susceptible to alcohol dependence and those who are not. A person‐centered focus also is useful with longitudinal data to represent heterogeneity in developmental trajectories. In alcohol, drug, and mental health research the recognition of heterogeneity has led to theories of multiple developmental pathways.Methods: This paper gives a brief overview of new methods that integrate variable‐ and person‐centered analyses. Methods discussed include latent class analysis, latent transition analysis, latent class growth analysis, growth mixture modeling, and general growth mixture modeling. These methods are presented in a general latent variable modeling framework that expands traditional latent variable modeling by including not only continuous latent variables but also categorical latent variables.Results: Four examples that use the National Longitudinal Survey of Youth (NLSY) data are presented to illustrate latent class analysis, latent class growth analysis, growth mixture modeling, and general growth mixture modeling. Latent class analysis of antisocial behavior found four classes. Four heavy drinking trajectory classes were found. The relationship between the latent classes and background variables and consequences was studied.Conclusions: Person‐centered and variable‐centered analyses typically have been seen as different activities that use different types of models and software. This paper gives a brief overview of new methods that integrate variable‐ and person‐centered analyses. The general framework makes it possible to combine these models and to study new models serving as a stimulus for asking research questions that have both person‐ and variable‐centered aspects.
Early Adult Outcomes of Adolescent Binge Drinking: Person‐ and Variable‐Centered Analyses of Binge Drinking Trajectories
Authors: Hill Karl G. , White Helene R. , Chung Ick‐Joong , Hawkins J. David , Catalano Richard F. 
Published: April 2006

Background: Many studies of the consequences of binge drinking take a variable‐centered approach that may mask developmentally different trajectories. Recent studies have reported qualitatively different binge drinking trajectories in young adulthood. However, analyses of developmental trajectories of binge drinking have not been examined for an important period of drinking development: adolescence. The purpose of this study was to examine young adult outcomes of adolescent binge drinking using an approach that combines person‐centered and variable‐centered methods.Methods: Data were from the Seattle Social Development Project, an ethnically diverse, gender balanced sample (n= 808) followed prospectively from age 10 to age 21. Semiparametric group‐based modeling was used to determine groups of binge drinking trajectories in adolescence. Logistic regression was used to examine how well the trajectory groups predicted young adult outcomes after demographics, childhood measures, and adolescent drug use were considered.Results: Four distinct trajectories of binge drinking during adolescence were identified: Early Highs, Increasers, Late Onsetters, and Nonbingers. These trajectories significantly predicted positive and negative outcomes in adulthood after controlling for demographic characteristics, early proxy measures of the outcome, and adolescent drug use.Conclusions: This integrated person‐ and variable‐centered approach provides more information about the effects of specific patterns of binge drinking than studies that employ variable‐centered methods alone.
Transitions in Drinking in Adolescent Females: Evidence From the Missouri Adolescent Female Twin Study
Authors: Bucholz K. K. , Heath A. C. , Madden P. A. F. 
Published: April 2006

Background: Data from adult community samples indicate that alcohol dependence originates in late adolescence, thus marking that period as a fruitful one for the study of transitions in drinking.Methods: Using retrospective data about the timing of alcohol symptom onset from 1799 female twins who participated in the Missouri Adolescent Female Twin Study (MOAFTS), we integrated person‐centered (PC) and variable‐centered (VC) analyses to study 1‐year transitions in alcohol symptomatology. A person‐year data set reflecting the onset of 15 alcohol dependence symptoms was constructed, with each year in the young woman's life from the year of her first drink to her current age counting as one observation. Latent class analysis—a PC technique—identified classes of alcohol symptomatology for each person‐year, and a lag function was used to identify class membership 1 year earlier. One‐year transitions in drinking—a VC analysis—were then studied.Results: Smoking, marijuana use, and conduct problems were consistent promoters of transitions to more severe drinking classes, but depressed affect was not a significant predictor. Parental history of alcohol problems or excessive drinking, particularly maternal history, was a significant predictor of more serious transitions to moderate and dependent problem drinking.Conclusions: These data confirm that even over a 1‐year time frame there was considerable change in drinking patterns in this adolescent sample. Smoking was as potent a risk factor as conduct problems in promoting the progression of alcohol symptomatology, and the role of familial factors was found to be influential in transitions at the more severe end of the drinking spectrum.
Use of a High‐Risk Alcohol Relapse Scale in Evaluating Liver Transplant Candidates
Authors: DiMartini Andrea , Magill Judy , Fitzgerald Mary Grace , Jain Ashok , Irish William , Khera Gagan , Yates William 
Published: April 2006

Background: Methods to improve assessment, selection, and monitoring of patients with alcoholic cirrhosis who pursue liver transplantation are sought continuously. We chose to investigate the use of the High‐Risk Alcohol Relapse (HRAR) scale in our transplant population in the hope that it would improve our ability to identify and follow patients at highest risk for alcohol relapse.Methods: Detailed alcohol histories of 207 patients evaluated for liver transplantation were collected and graded for severity by using the HRAR. The HRAR provides information on the duration of alcohol use (a measure of chronicity), daily quantity of alcohol use, and rehabilitation experiences (treatment responsiveness). Posttransplant alcohol use was monitored through clinical follow‐up in the transplant clinic.Results: Although men and women had similar years of heavy drinking pretransplant, women's daily alcohol consumption was significantly less than men’s. HRAR scores did not distinguish those listed for transplant from those not listed or those who drank posttransplant from those who did not. Transplant patients were predominantly in the low‐risk group (83% had an HRAR score <4).Conclusions: The HRAR did not have predictive ability in our transplant population. Few of our patients were rated as high risk, and few drank posttransplant. Nevertheless, identifying patients at high risk may improve clinical care and decrease the rate of posttransplant alcohol consumption.
Understanding Drinking During Pregnancy Among Urban American Indians and African Americans: Health Messages, Risk Beliefs, and How We Measure Consumption
Authors: Kaskutas Lee Ann 
Published: April 2006

Background: Little is known about urban American Indian and African American women's drinking during pregnancy, or their beliefs about the risk of doing so. However, rates of fetal alcohol syndrome (FAS) are believed to be highest among those ethnic groups.Methods: The Developing Effective Educational Resources (DEER) project recruited pregnant American Indian, African American, and white women from urban California areas (n= 321), to develop culturally appropriate consumption measures, to gather epidemiological data about drinking during pregnancy, and to assess exposure and reactions to health warnings intended to encourage abstinence during pregnancy.Results: The study found high levels of exposure to health warnings among all ethnic groups, but many women were unclear about the actual consequences of FAS, about the risk of drinking even beer or wine or wine coolers, or about the value of reducing intake at any time during pregnancy. The majority of the women who drank malt liquor, fortified wine, wine, and spirits reported having larger than standard drinks, and daily drinkers had the highest levels of reporting error. When drink size was considered in the calculation of alcohol volume, average daily volume of consumption during pregnancy increased to the FAS risk level (average daily volume ≥ 1) in the overall sample and among the African American and white subjects.Conclusions: Because some women, especially heavy drinkers, will continue drinking despite exposure to abstention‐oriented health messages, it may be prudent to develop campaigns and interventions that provide factual information to help at‐risk women reduce their drinking during pregnancy. Women could be advised of beverage equivalency, of standard drink sizes, and of how their own drinks compare with standard ones. Reliance on standard drink sizes in research can result in significant underreporting of consumption, especially among pregnant risk drinkers.