The finding that intermittent exposure produces more rapid increases in self-administration of ethanol relative to continuous exposure suggests that intermittent exposure may be associated with a more rapid escalation of the allostatic processes responsible for excessive ethanol self-administration. The mechanisms that drive the increases in drinking during withdrawal are similar after 2 and 8 hr of withdrawal and seem to be specific to ethanol.

Recently, there have been some reports that changes in serum lipid composition may be related to suicide, major depression and immune-inflammatory responses. Findings from our laboratory suggest that major depression is accompanied by reduced formation of cholesteryl esters and perhaps by impairment of reverse cholesterol transport. The latter is reportedly accompanied by lower serum high-density lipoprotein cholesterol (HDL-C). The aim of this study was to examine whether (i) major depression is accompanied by lower serum HDL-C or by abnormal levels of serum total cholesterol, triglycerides, low-density lipoprotein-C (LDL-C) or vitamin E, (ii) suicidal attempts are related to lower serum HDL-C and (iii) there are significant associations between serum HDL-C and immune/inflammatory markers. A total of 36 subjects with major depression, of whom 28 patients showed treatment resistance, as well as 28 normal control subjects, had blood sampled for the assay of the above lipids, serum zinc (Zn), albumin (Alb) and flow cytometric determination of the T-helper/T-suppressor (CD4+/CD8+) T-cell ratio. In total, 28 depressed subjects had repeated measures of these variables both before and after treatment with antidepressants. Serum HDL-C and total cholesterol, as well as the HDL-C/cholesterol ratio, were significantly lower in subjects with major depression than in normal controls. Serum HDL-C levels were significantly lower in depressed men who had at some time made serious suicidal attempts than in those without such suicidal behaviour. Treatment with antidepressants for 5 weeks did not significantly alter either serum HDL-C or other lipid variables. Serum HDL-C levels were significantly and negatively correlated with the (CD4+/CD8+) T-cell ratio, and positively correlated with serum Alb and Zn. These results suggest that (i) lower serum HDL-C levels are a marker for major depression and suicidal behaviour in depressed men, (ii) lower serum HDL-C levels are probably induced by the immune/inflammatory response in depression and (iii) there is impairment of reverse cholesterol transport from the body tissues to the liver.

The negative effects of nicotine withdrawal are lower during adolescence relative to later periods of development. Both the enhanced rewarding effects and the diminished nicotine withdrawal likely contribute to the rapid development of nicotine use during adolescence.

The present study characterized nicotine intake, circadian patterns of food and water intake, precipitated somatic signs of withdrawal, and extinction of nicotine-seeking behavior in rats with 23-h access to intravenous self-administration (IVSA). Separate groups of animals were allowed access to nicotine IVSA (0.015, n ϭ 9; 0.03, n ϭ 14; 0.06, n ϭ 16; mg/kg/0.1 ml infusion/s; fixed ratio 1) and trained to nosepoke for food and water 23 h/day for 40 consecutive days. Somatic signs of nicotine withdrawal were examined following saline or mecamylamine administration (1.5 mg/kg i.p.), and extinction of nicotine-seeking behavior was assessed. A dose-dependent decrease in lever responding and an increase in nicotine intake were observed, with the highest nicotine dose producing the lowest amount of lever responding and the highest amount of nicotine intake. Nicotine acutely reduced diurnal and nocturnal food intake, producing smaller and fewer meals, and an increased rate of eating. Differences in rate of nicotine intake between the light and dark phase decreased significantly, especially in rats receiving higher unit nicotine doses (0.03 and 0.06 mg/kg), along with long-term decreases in the circadian profile and amplitude of feeding. Mecamylamine precipitated robust withdrawal signs, the magnitude of which was positively correlated with the total amount of self-administered nicotine. Extinction of nicotine-seeking behavior was observed and was facilitated by removal of nicotine-associated cues. The results demonstrate that rats will self-administer nicotine to the point of producing dependence, as measured by somatic signs, resistance to extinction, and measures of food intake.To more closely model tobacco use in humans, recent studies have examined extended access to nicotine intravenous self-administration (IVSA) in rats. For example, female rats display increased nicotine IVSA during the active phase of the light cycle during 3 weeks of continuous nicotine access (Cox et al., 1984). These rats also display a compensatory increase in nicotine IVSA when the dose is lowered (0.03 to 0.003 mg/kg) and a decrease in nicotine-seeking behavior when nicotine is replaced with saline. Moreover, male rats display nicotine IVSA in extended access models (6 -23 h) using low nicotine doses (0.00375 mg/kg/injection), and the level of nicotine intake approximates that of human smokers (Valentine et al., 1997;Paterson and Markou, 2004;Kenny and Markou, 2006). The 23-h access model of nicotine IVSA seems to be sensitive to genetic differences, since nicotine intake is more quickly acquired and persistently maintained in Lewis versus Holtzman and Fisher strains of male rats (Brower et al., 2002). Furthermore, the 23-h model of nicotine IVSA is sensitive to passive nicotine administration. Nicotine intake decreased following implantation of a minipump that delivers doses of nicotine that are equal to, or higher than, peak levels associated with simulated nicotine intake (LeSage et al., 2002). In addition, nicotine intake in ...

The purpose of this study was to examine changes in various aerobic and anaerobic physical performance measures in male National Collegiate Athletic Association (NCAA) Division III soccer players during the competitive soccer season. Twelve starters of the men's soccer team (mean +/- SD; age = 20.0 +/- 0.9 years, height = 175.7 +/- 8.1 cm, body mass = 73.9 +/- 11.00 kg, body mass index [BMI] 24.0 +/- 3.0 kg.m2, and percent body fat = 10.6 +/- 5.4%) were tested at the beginning (PRS) and the end (POS) of the collegiate soccer season. Each experimental trial included a maximal aerobic capacity test (VO2max); 10-, 30-, and 40-m sprints; pro-agility test; and the Wingate anaerobic power test (WAnT). From PRS to POS, VO2max significantly increased (51.05 +/- 5.97 vs. 54.64 +/- 4.90 ml.kg-1.min-1), and the 10- and 30-m sprint were significantly lower (2.03 +/- 0.15 vs. 1.96 +/- 0.11 seconds and 4.72 +/- 0.26 vs. 4.51 +/- 0.24 seconds, respectively). Anthropometric measures, 40-m sprint, pro-agility test, and WAnT were not significantly different between PRS and POS. The results of this study indicate that NCAA Division III male soccer players appear to improve aerobic and anaerobic performance measures during the competitive soccer season. It is arguable that these performance improvements may represent a poor preseason conditioning level that may result in a competitive disadvantage during the early stages of the season. An ongoing process of recruiting better-quality players that may closely follow the off-season training regimen may partially remedy this problem.