Control of chronic excessive alcohol drinking by genetic manipulation of the Edinger-Westphal nucleus urocortin-1 neuropeptide system.

Midbrain neurons of the centrally projecting Edinger-Westphal nucleus (EWcp) are activated by alcohol, and enriched with stress-responsive neuropeptide modulators (including the paralog of corticotropin-releasing factor, urocortin-1). Evidence suggests that EWcp neurons promote behavioral processes for alcohol-seeking and consumption, but a definitive role for these cells remains elusive. Here we combined targeted viral manipulations and gene array profiling of EWcp neurons with mass behavioral phenotyping in C57BL/6 J mice to directly define the links between EWcp-specific urocortin-1 expression and voluntary binge alcohol intake, demonstrating a specific importance for EWcp urocortin-1 activity in escalation of alcohol intake.

Strain differences in delay discounting using inbred rats.

A heightened aversion to delayed rewards is associated with substance abuse and numerous other neuropsychiatric disorders. Many of these disorders are heritable, raising the possibility that delay aversion may also have a significant genetic or heritable component. To examine this possibility, we compared delay discounting in six inbred strains of rats (Brown Norway, Copenhagen, Lewis, Fischer, Noble and Wistar Furth) using the adjusting amount procedure, which provides a measure of the subjective value of delayed rewards. The subjective value of rewards decreased as the delay to receipt increased for all strains. However, a main effect of strain and a strain x delay interaction indicated that some strains were more sensitive to the imposition of delays than others. Fitting a hyperbolic discount equation showed significant strain differences in sensitivity to delay (k). These data indicate that there are significant strain differences in delay discounting. All strains strongly preferred the 10% sucrose solution (the reinforcer in the delay discounting task) over water and the amount of sucrose consumed was correlated with sensitivity to delay. Locomotor activity was not correlated with delay discounting behavior. Additional research will be required to disentangle genetic influences from maternal effects and to determine how these factors influence the underlying association between heightened delay discounting and neuropsychiatric disorders.

Rats bred for high alcohol drinking are more sensitive to delayed and probabilistic outcomes.

Alcoholics and heavy drinkers score higher on measures of impulsivity than nonalcoholics and light drinkers. This may be because of factors that predate drug exposure (e.g. genetics). This study examined the role of genetics by comparing impulsivity measures in ethanol-naive rats selectively bred based on their high [high alcohol drinking (HAD)] or low [low alcohol drinking (LAD)] consumption of ethanol. Replicates 1 and 2 of the HAD and LAD rats, developed by the University of Indiana Alcohol Research Center, completed two different discounting tasks. Delay discounting examines sensitivity to rewards that are delayed in time and is commonly used to assess 'choice' impulsivity. Probability discounting examines sensitivity to the uncertain delivery of rewards and has been used to assess risk taking and risk assessment. High alcohol drinking rats discounted delayed and probabilistic rewards more steeply than LAD rats. Discount rates associated with probabilistic and delayed rewards were weakly correlated, while bias was strongly correlated with discount rate in both delay and probability discounting. The results suggest that selective breeding for high alcohol consumption selects for animals that are more sensitive to delayed and probabilistic outcomes. Sensitivity to delayed or probabilistic outcomes may be predictive of future drinking in genetically predisposed individuals.

D4 receptor deficiency in mice has limited effects on impulsivity and novelty seeking.

Alleles of the human dopamine D(4) receptor (D(4)R) gene (DRD4.7) have repeatedly been found to correlate with novelty seeking, substance abuse, pathological gambling, and attention-deficit hyperactivity disorder (ADHD). If these various psychopathologies are a result of attenuated D(4)R-mediated signaling, mice lacking D(4)Rs (D(4)KO) should be more impulsive than wild-type (WT) mice and exhibit more novelty seeking. However, in our study, D(4)KO and WT mice showed similar levels of impulsivity as measured by delay discounting performance and response inhibition on a Go/No-go test, suggesting that D(4)R-mediated signaling may not affect impulsivity. D(4)KO mice were more active than WT mice in the first 5 min of a novel open field test, suggesting greater novelty seeking. For both genotypes, more impulsive mice habituated less in the novel open field. These data suggest that the absence of D(4)Rs is not sufficient to cause psychopathologies associated with heightened impulsivity and novelty seeking.

Occurrence of pesticide residues in mushrooms in Northern Ireland, July 1997-January 1999.

The results of surveillance monitoring for pesticides in mushrooms obtained from wholesale cooperatives in Northern Ireland between 1997 and 1999 are presented. Samples (n = 145) were analysed for up to 11 pesticides, resulting in 1575 pesticide/crop combinations. Fifty-five (38%) samples did not contain detectable residues, with 90 (62%) samples containing residues above their respective detection limits. Residues (carbendazim) above the maximum residue level were found in two (<2%) samples. The most frequently detected residues were diflubenzuron and carbendazim present in 47 (32%) and 38 (26%) samples, respectively. There was no significant seasonality in the distribution of the residues.

Carbendazim and metalaxyl residues in post-harvest treated apples.

Bramley apples were treated with Ridomil mbc 60 WP, containing carbendazim and metalaxyl, at half and full rate application at 10 and 20 degrees C, and with diphenylamine to control disease during storage. Carbendazim and metalaxyl residues were determined by HPLC and GC/MS, respectively, in apple core, flesh and peel at the initial time, 3 and 6 months after storage under controlled atmosphere conditions of 4.5 degrees C, 5% CO(2) and 1% O(2). The concentration of carbendazim residues in apple flesh was

Effects of docosahexaenoic acid and eicosapentaenoic acid on androgen-mediated cell growth and gene expression in LNCaP prostate cancer cells.

There is some epidemiological support for a protective influence of omega-3 fatty acids against prostate cancer. We wanted to explore whether omega-3 polyunsaturated fatty acids such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) can affect androgen receptor function in prostate cancer cells. Our study showed that both DHA and EPA inhibit androgen-stimulated cell growth. Androgenic induction of prostate-specific antigen (PSA) protein was repressed by DHA and EPA in a dose-dependent manner. The mRNA levels of five androgen up-regulated genes, PSA, ornithine decarboxylase, NKX 3.1, immunophilin fkbp 51 and Drg-1, were decreased with DHA treatment in the presence of androgens. Transfection experiments using a DNA vector containing androgen-responsive elements demonstrated that both DHA and EPA could interfere with transactivation activities of the androgen receptor (AR). However, western blot analysis of AR protein showed that DHA and EPA treatments did not change AR expression levels. Interestingly, the proto-oncoprotein c-jun was increased by DHA treatment. A transient transfection found that forced expression of c-jun inhibited AR transactivation activity. Thus, this study found that the inhibitory effects of omega-3 polyunsaturated fatty acids on AR-mediated actions are due, at least in part, to an increase in c-jun protein.

Quercetin inhibits the expression and function of the androgen receptor in LNCaP prostate cancer cells.

The androgen receptor (AR) is involved in the development and progression of prostate cancer. In order to find new compounds that may present novel mechanisms to attenuate the function of AR, we investigated the effect of a natural flavonoid chemical, quercetin, on androgen action in an androgen-responsive LNCaP prostate cancer cell line. Western blot analysis showed that AR protein expression was inhibited by quercetin in a dose-dependent manner. To demonstrate that the repression effects on AR expression can actually reduce its function, we found that quercetin inhibited the secretion of the prostate-specific, androgen-regulated tumor markers, PSA and hK2. The mRNA levels of androgen-regulated genes such as PSA, NKX3.1 as well as ornithine decarboxylase (ODC) were down-regulated by quercetin. Transient transfections further showed that quercetin inhibited AR-mediated PSA expression at the transcription level. Finally, it was demonstrated that quercetin could repress the expression of the AR gene at the transcription level. Our result suggests that quercetin can attenuate the function of AR by repressing its expression and has the potential to become a chemopreventive and/or chemotherapeutic agent for prostate cancer.

An androgen response element mediates LNCaP cell dependent androgen induction of the hK2 gene.

Human glandular kallikrein (hK2) is an androgen regulated protein primarily expressed in the prostate and recently identified as a novel prostate cancer marker. A 5 kb 5' flanking region of the hK2 gene was isolated and sequenced to characterize the regulatory mechanisms for the expression of hK2 in the androgen responsive prostate cell line, LNCaP. Using gene transfer, gel shift, and mutagenesis assays we have identified an ARE in the 5' far upstream promoter region of the hK2 gene that is crucial for its regulation in LNCaP cells. This study further demonstrated that the hK2 upstream ARE plays a predominant role in androgenic response. More interestingly, previously identified AREs in the prostate specific antigen promoter and the hK2 proximal promoter exert little activity in LNCaP cells. This study for the first time identifies a unique ARE that alone mediates the function of the androgen receptor in LNCaP cells in a cell dependent manner. This study also examines the activity of this ARE with 1alpha, 25 dihydroxy-vitamin D3 on the expression of the hK2 gene in LNCaP cells.

Tea polyphenols down-regulate the expression of the androgen receptor in LNCaP prostate cancer cells.

Androgens via their cognate receptor may be involved in the development and progression of prostate cancer. The aim of this study was to determine whether tea polyphenols have inhibitory effects on androgen action in an androgen-responsive, prostate cancer cell line, LNCaP. The tea polyphenol, EGCG, inhibited LNCaP cell growth and the expression of androgen regulated PSA and hK2 genes. Moreover, EGCG had a significant inhibitory effect on the androgenic inducibility of the PSA promoter. Immunoblotting detected a decrease in androgen receptor protein with treatments of the tea polyphenols EGCG, GCG and theaflavins. Northern blot analysis showed decreased levels of androgen receptor mRNA by EGCG. Transient transfections demonstrated that EGCG and theaflavins could repress the transcriptional activities of the androgen receptor promoter region. An Sp1 binding site in the androgen receptor gene promoter is an important regulatory component for its expression. This study suggests Sp1 is the target for the tea polyphenols because treatments of EGCG decreased the expression, DNA binding activity and transactivation activity of Sp1 protein. In conclusion, we have described a new property of tea polyphenols that inhibits androgen action by repressing the transcription of the androgen receptor gene.

Nonapoptotic cell death associated with S-phase arrest of prostate cancer cells via the peroxisome proliferator-activated receptor gamma ligand, 15-deoxy-delta12,14-prostaglandin J2.

15-Deoxy-delta12,14-prostaglandin J2 (15d-PGJ2) is a highly specific activator of the peroxisome proliferator-activated receptor gamma (PPAR-gamma). We investigated the effect of 15d-PGJ2 on three human prostate cancer cell lines, LNCaP, DU145, and PC-3. Western blotting demonstrated that PPAR-gamma1 is expressed predominantly in untreated prostate cancer cells. Treatment with 15d-PGJ2 caused an increase in the expression of PPAR-gamma2, whereas PPAR-gamma1 remained at basal levels. PPARs alpha and beta were not detected in these cells. Lack of lipid accumulation, increase in CCAAT/enhancer binding proteins (C/EBPs), or expression of aP2 mRNA indicated that adipocytic differentiation is not induced in these cells by 15d-PGJ2. 15d-PGJ2 and other PPAR-gamma activators induced cell death in all three cell lines at concentrations as low as 2.5 microM (similar to the Kd of PPAR-gamma for this ligand), coinciding with an accumulation of cells in the S-phase of the cell cycle. Activators for PPAR-alpha and beta did not induce cell death. Staining with trypan blue and propidium iodide suggested that, although the plasma membrane appears intact by electron microscopy, disturbances are evident as early as 2 h after treatment. Mitochondrial transmembrane potentials are significantly reduced by 15d-PGJ2 treatment. In addition, treatment with 15d-PGJ2 resulted in cytoplasmic changes, which are indicative of type 2 (autophagic), nonapoptotic programmed cell death.

Resveratrol inhibits the expression and function of the androgen receptor in LNCaP prostate cancer cells.

Androgens via their receptor (AR) may play a role in prostate cancer etiology. This study focuses on the inhibitory effects of resveratrol on androgen action in the LNCaP prostate cancer cell line. We found that resveratrol represses different classes of androgen up-regulated genes at the protein or mRNA level including prostate-specific antigen, human glandular kallikrein-2, AR-specific coactivator ARA70, and the cyclin-dependent kinase inhibitor p21. This inhibition is likely attributable to a reduction in AR contents at the transcription level, inhibiting androgen-stimulated cell growth and gene expression. This study suggests that resveratrol may be a useful chemopreventive/chemotherapeutic agent for prostate cancer.

Measures of impulsivity in cigarette smokers and non-smokers.

RATIONALE: Drug users are thought to be more "impulsive" than non-users. OBJECTIVES: This study examined whether regular smokers are more impulsive than never smokers using personality and behavioral measures of impulsivity. METHODS: Twenty regular smokers (>/=15 cigarettes/day) and 20 never smokers were recruited. Participants completed five personality questionnaires to assess impulsivity: Adjective Checklist, Barratt's Impulsivity Scale, the Tridimensional Personality Questionnaire, Eysenck's Personality Questionnaire, and the Sensation-Seeking Scale. Participants also performed three behavioral choice tasks designed to assess impulsivity. In the delay task, participants chose between small, immediate and large, delayed monetary rewards. Impulsivity was defined as a relative preference for the small, immediate alternative. In the probability task, participants chose between small, certain and large, uncertain monetary rewards. Impulsivity was defined as a relative preference for the large but more risky alternative. In the work task, participants chose between small monetary rewards obtained by performing a negligible amount of work and a larger amount of money requiring more work. Impulsivity was defined as a relative preference for the smaller, easier alternative. RESULTS: On the personality questionnaires, smokers had statistically higher impulsivity scores on most scales. On the behavioral choice tasks, smokers chose small, immediate money over large, delayed money more frequently, signifying greater levels of impulsivity. There were no differences between the groups' choices on the other tasks. Correlations between questionnaire and task data were small, as were correlations between data from each task. CONCLUSIONS: Together, these results indicate that the smokers were more impulsive than never smokers.

Delay or probability discounting in a model of impulsive behavior: effect of alcohol.

Little is known about the acute effects of drugs of abuse on impulsivity and self-control. In this study, impulsivity was assessed in humans using a computer task that measured delay and probability discounting. Discounting describes how much the value of a reward (or punisher) is decreased when its occurrence is either delayed or uncertain. Twenty-four healthy adult volunteers ingested a moderate dose of ethanol (0.5 or 0.8 g/kg ethanol: n = 12 at each dose) or placebo before completing the discounting task. In the task the participants were given a series of choices between a small, immediate, certain amount of money and $10 that was either delayed (0, 2, 30, 180, or 365 days) or probabilistic (i.e., certainty of receipt was 1.0, .9, .75, .5, or .25). The point at which each individual was indifferent between the smaller immediate or certain reward and the $10 delayed or probabilistic reward was identified using an adjusting-amount procedure. The results indicated that (a) delay and probability discounting were well described by a hyperbolic function; (b) delay and probability discounting were positively correlated within subjects; (c) delay and probability discounting were moderately correlated with personality measures of impulsivity; and (d) alcohol had no effect on discounting.

Reduced gas transfer at rest and during exercise in school-age survivors of bronchopulmonary dysplasia.

School-age children who survive bronchopulmonary dysplasia (BPD) may have a permanent reduction in alveolar surface area that could limit gas transfer both at rest and during exercise. To test this hypothesis, 10 survivors of BPD, 10 children born prematurely without BPD, and 10 healthy children born at term, 6 to 9 yr of age, underwent treadmill exercise studies. During a three-phase protocol we measured intrabreath acetylene (C2H2) and carbon monoxide (CO) transfer, pulmonary function, and SaO2. Both at rest and during exercise, C2H2 transfer corrected for body surface area was lower in survivors of BPD than it was in children born prematurely without BPD or children born at term. With exercise the transfer of both gases increased sharply over resting values in children born prematurely and at term. In survivors of BPD C2H2 transfer with exercise did increase, but not as much as it did in control subjects, and corrected CO transfer did not change at all. In survivors of BPD and children born prematurely, FEV1 fell during recovery from exercise, but this did not correlate with C2H2 transfer or DL(CO)/VA. Thus, soluble gas transfer at rest and during acute exercise is reduced in children who survive BPD. This is likely explained either by long-term derangements in lung structure or residual right ventricular dysfunction affecting cardiac output.

Determination of discount functions in rats with an adjusting-amount procedure.

An adjusting-amount procedure was used to measure discounting of reinforcer value by delay. Eight rats chose between a varying amount of immediate water and a fixed amount of water given after a delay. The amount of immediate water was systematically adjusted as a function of the rats' previous choices. This procedure was used to determine the indifference point at which each rat chose the immediate amount and the delayed amount with equal frequency. The amount of immediate water at this indifference point was used to estimate the value of the delayed amount of water. In Experiment 1, the effects of daily changes in the delay to the fixed reinforcer (100 microliters of water delivered after 0, 2, 4, 8, or 16 s) were tested. Under these conditions, the rats reached indifference points within the first 30 trials of each 60-trial session. In Experiment 2, the effects of water deprivation level on discounting of value by delay were assessed. Altering water deprivation level affected the speed of responding but did not affect delay discounting. In Experiment 3, the effects of varying the magnitude of the delayed water (100, 150, and 200 microliters) were tested. There was some tendency for the discounting function to be steeper for larger than for smaller reinforcers, although this difference did not reach statistical significance. In all three experiments, the obtained discount functions were well described by a hyperbolic function. These experiments demonstrate that the adjusting-amount procedure provides a useful tool for measuring the discounting of reinforcer value by delay.

The work costs of earning food as a determinant of patch leaving.

Foraging theorists have long emphasized the role of the energy (work) costs of food items on foraging behavior. However, few experiments have measured this variable or demonstrated that animals are indeed sensitive to work costs. Experiment 1 assessed whether rats (Long-Evans) can use the work costs of food to determine whether a food patch is exhausted. Rats performed a fixed amount of work for each food item (fixed-work [FW] schedule), but food was withheld unpredictably to simulate sudden patch depletion. It was found that rats left patches only when the work costs of unsuccessful searches (giving-up work) exceeded the prevailing work costs of food. The time and response costs of unsuccessful food searches (giving-up time and giving-up responses) were not predictive of patch leaving. Experiment 2 showed how rats regulated work in this paradigm by examining the role of exteroceptive stimuli connected with fulfilling the FW schedule.

The effects of ethanol on the relative preference for cigarettes.

This study examined the effects of ethanol preloading on preference for tobacco cigarettes in 10 nicotine-dependent volunteers. The crossover, double-blind study involved pretreating participants with 0, 0.2, 0.4 or 0.8 g/kg ethanol immediately prior to a task in which cigarettes and/or money could be earned. Tobacco cigarette preference was measured using the number of responses performed and reinforcers earned on a series of concurrent random-ratio schedules that yielded tobacco and money reinforcers. In addition to the preference measures, subjective effects and psychomotor performance were assessed before beverage ingestion and at regular intervals afterwards. Ethanol induced alterations in mood and psychomotor performance in a dose-related fashion. However, preference for tobacco cigarettes was not affected by ethanol pretreatment. The present study suggests that the increase in cigarette smoking that is associated with ethanol consumption does not involve changes in smokers' preference for cigarettes.

Infants with bronchopulmonary dysplasia: a developmental perspective.

Infants with bronchopulmonary dysplasia (BPD) are medically fragile and developmentally at risk for neuromotor and sensory delays. long-term neurodevelopmental outcomes can be positively impacted by an organized and purposeful program of developmental follow-up and early intervention. Nurses play an integral role in provision and coordination of the multifaceted health care required by these medically fragile infants.