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Selected AbstractsPRECLINICAL STUDY: FULL ARTICLE: Repeated ethanol administration modifies the temporal structure of sucrose intake patterns in mice: effects associated with behavioral sensitizationADDICTION BIOLOGY, Issue 3 2010Raśl Pastor ABSTRACT Neuroadaptations supporting behavioral sensitization to abused drugs are suggested to underlie pathological, excessive motivation toward drugs and drug-associated stimuli. Drug-induced sensitization has also been linked to increased appetitive responses for non-drug, natural reinforcers. The present research investigated whether ethanol (EtOH)-induced neural changes, inferred from psychomotor sensitization, can modify consumption and intake dynamics for the natural reinforcer, sucrose. The effects of EtOH-induced sensitization in mice on the temporal structure of sucrose intake patterns were measured using a lickometer system. After sensitization, sucrose intake dynamics were measured for 1 hour daily for 7 days and indicated more rapid initial approach and consumption of sucrose in EtOH-sensitized groups; animals showed a shorter latency to the first intake bout and an increased number of sucrose bottle licks during the initial 15 minutes of the 1-hour sessions. This effect was associated with increased frequency and size of bouts. For the total 1-hour session, sucrose intake and bout dynamics were not different between groups, indicating a change in patterns of sucrose intake but not total consumption. When sensitization was prevented by the ,-aminobutyric acid B receptor agonist, baclofen, the increased rate of approach and consumption of sucrose were also prevented. Thus, EtOH-induced sensitization, and not the mere exposure to EtOH, was associated with changes in sucrose intake patterns. These data are consistent with current literature suggesting an enhancing effect of drug-induced sensitization on motivational processes involved in reinforcement. [source] Stages of Change, Processes of Change, and Social Support for Exercise and Weight Gain in Postpartum WomenJOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 2 2006Colleen Keller Objectives:, To test the extent to which social support and variables included in the Transtheoretical Model were explanatory for exercise initiation and weight maintenance in postpartum women. Design:, A cross-sectional descriptive design. Setting:, Data were collected in the participant's homes. Participants:, Postpartum women who had normal pregnancies were interviewed and measured on body fat, physical activity, and psychosocial scales. Main outcome measure:, (a) Stages of exercise change measure, (b) Seven Day Recall, (c) Friend and Family Support for Exercise Scale, (d) Processes of Change Questionnaire, and (e) body fat measures including body mass index and percent body fat. Results:, Forty percent reported engaging in vigorous activity less than 1 hour daily, 55% walked less than four city blocks daily, and 52% engaged in less than 2 hours of vigorous weekend activity. Multilinear regression showed that the processes of change contributed 36% to the body mass index, and 21% of the variance in waist-thigh ratio. Of the processes of change, environmental reevaluation correlated significantly with body mass index. Conclusion:, The impact of a woman's weight on others as well as information concerning the health effects of obesity and physical activity could enhance the initiation of exercise in the postpartum woman. JOGNN, 35, 232-240; 2006. DOI: 10.1111/J.1552-6909.2006.00030.x [source] Intracellular Na+ and Ca2+ modulation increases the tensile properties of developing engineered articular cartilageARTHRITIS & RHEUMATISM, Issue 4 2010Roman M. Natoli Objective Significant collagen content and tensile properties are difficult to achieve in tissue-engineered articular cartilage. The aim of this study was to investigate whether treating developing tissue-engineered cartilage constructs with modulators of intracellular Na+ or Ca2+ could increase collagen concentration and construct tensile properties. Methods Inhibitors of Na+ ion transporters and stimulators of intracellular Ca2+ were investigated for their ability to affect articular cartilage development in a scaffoldless, 3-dimensional chondrocyte culture. Using a systematic approach, we applied ouabain (Na+/K+ -ATPase inhibitor), bumetanide (Na+/K+/2Cl, tritransporter inhibitor), histamine (cAMP activator), and ionomycin (a Ca2+ ionophore) to tissue-engineered constructs for 1 hour daily on days 10,14 of culture and examined the constructs at 2 weeks or 4 weeks. The gross morphology, biochemical content, and compressive and tensile mechanical properties of the constructs were assayed. Results The results of these experiments showed that 20 ,M ouabain, 0.3 ,M ionomycin, or their combination increased the tensile modulus by 40,95% compared with untreated controls and resulted in an increased amount of collagen normalized to construct wet weight. In constructs exposed to ouabain, the increased percentage of collagen per construct wet weight was secondary to decreased glycosaminoglycan production on a per-cell basis. Treatment with 20 ,M ouabain also increased the ultimate tensile strength of neo-tissue by 56,86% at 4 weeks. Other construct properties, such as construct growth and type I collagen production, were affected differently by Na+ modulation with ouabain versus Ca2+ modulation with ionomycin. Conclusion These data are the first to show that treatments known to alter intracellular ion concentrations are a viable method for increasing the mechanical properties of engineered articular cartilage and identifying potentially important relationships to hydrostatic pressure mechanotransduction. Ouabain and ionomycin may be useful pharmacologic agents for increasing tensile integrity and directing construct maturation. [source] Circadian Timing of Ethanol Exposure Exerts Enduring Effects on Subsequent Ad Libitum Consumption in C57 MiceALCOHOLISM, Issue 7 2009Jennifer L. Trujillo Background:, There is a daily rhythm in the voluntary intake of ethanol in mice, with greatest consumption in the early night and lowest intake during the day. The role of daily timing of ethanol exposure on the development and control of long-term ethanol self-administration has been neglected. The present study examines these issues using C57BL/6J mice. Methods:, Mice were repeatedly exposed to 10% ethanol for 2 hours early in the night or day for several weeks. Subsequently, ethanol was available at the opposite time (Expt 1) or 24 hours daily (Expts 1 and 2). Lick sensors recorded the patterns of drinking activity in Experiment 2. Results:, Mice exposed to ethanol during the night drink more than mice exposed during the day. Prior history did not affect ethanol intake when the schedule was reversed. Under 24-hour exposure conditions, mice with a history of drinking during the night consumed significantly more than mice drinking during the day. The circadian patterns of drinking were not altered. Conclusions:, These results demonstrate that the daily timing of ethanol exposure exerts enduring effects of self-administration of ethanol in mice. Understanding how circadian rhythms regulate ethanol consumption may be valuable for modifying subsequent intake. [source] The ,1 -Adrenergic Receptor Antagonist, Prazosin, Reduces Alcohol Drinking in Alcohol-Preferring (P) RatsALCOHOLISM, Issue 2 2009Dennis D. Rasmussen Background:, Preliminary evidence suggest that noradrenergic signaling may play a role in mediating alcohol drinking behavior in both humans and rats. Accordingly, we tested the hypothesis that blockade of ,1 -adrenergic receptors will suppress alcohol drinking in rats selectively bred for alcohol preference (P line). Methods:, Adult male P rats were given 24-hour access to food and water and scheduled access to a 15% (v/v) alcohol solution for 2 hours daily. Rats were injected IP with the ,1 -adrenergic receptor antagonist, prazosin (0, 0.5, 1.0, 1.5, or 2.0 mg/kg body weight), once a day at 15 minutes prior to onset of the daily 2-hour 2-bottle choice, alcohol versus water, access period for 2 consecutive days and then 3 weeks later for 5 consecutive days. Results:, Prazosin significantly reduced (p < 0.01) alcohol intake during the initial 2 daily administrations, and this reduction of alcohol intake was maintained for 5 consecutive days by daily prazosin treatment in the subsequent more prolonged trial (p < 0.05). The prazosin-induced reduction of alcohol intake was not dependent upon drug-induced motor impairment since increases in water drinking (p < 0.05) were exhibited during the 2-hour access periods during both 2- and 5-day prazosin treatment. Conclusions:, The results indicate that the noradrenergic system plays a role in mediating alcohol drinking in rats of the P line and suggest that prazosin,a safe, well-characterized, and well-tolerated drug,may be an effective pharmacotherapeutic agent for the treatment of alcohol use disorders. [source] | ||||||||||