Nicotine interactions with dopamine agonists: Effects on working memory function

Nicotine has been found to improve memory performance in a variety of tests including the radial-arm maze. Nicotine may have effects mediated by promoting the release of dopamine. The present study was conducted to determine the interactions of nicotine with D₁ and D₂ agonists. Rats were acutely administered nicotine, the D₁ agonist SKF 38393, and D₂/D₃ agonist quinpirole, and nicotine together with each of these agonists. Nicotine significantly improved choice accuracy in the radial-arm maze. The D₁ agonist SKF 38393 significantly impaired choice accuracy. Nicotine was effective in reversing this effect. The D₂/D₃ agonist quinpirole showed a trend toward potentiating the improvement in choice accuracy caused by 0.2 mg/kg (0.43 μmol/kg) of nicotine. These data show that, as with the nicotinic antagonist mecamylamine, there are significant interactions of dopamine systems with nicotine effects. © 1994 Wiley-Liss, Inc.     

A double-blind, placebo-controlled study of the effect of imipramine on TRH-induced urinary urgency in healthy men.

We studied the effect of imipramine (IMI) on thyroid releasing hormone (TRH)-induced urinary urgency as a way of investigating the mechanism of the beneficial effect of IMI on enuresis. In a double-blind study, 12 normal, healthy men between 21 and 39 yr of age ranked their urge to urinate at 30-sec intervals following IV injection of TRH (500 micrograms) or saline. The subjects then were randomly assigned to either IMI (1 mg/kg) or placebo groups for 10 days, and the procedure was repeated. Compared to saline, TRH produced a significant elevation in urinary urgency in all subjects. IMI did not significantly blunt TRH-induced urinary urgency. Thus, the mechanism by which IMI affects enuresis is likely not mediated at the level of the urinary urgency induced by TRH.     

Perceived control of asthma and quality of life among adults with asthma.

BACKGROUND: Perceived control of certain chronic conditions influences health status outcomes. OBJECTIVE: To explore the impact of perceived control of asthma on asthma-specific and generic health status outcomes among adults with asthma. Perceived control was defined as individuals' perceptions of their ability to deal with asthma and its exacerbations. METHODS: Data were drawn from the baseline and first two followups of a longitudinal study of adults with asthma surveyed by telephone at 18-month intervals. An 11-item questionnaire (Perceived Control of Asthma Questionnaire [PCAQ]) was developed and validated. RESULTS: The PCAQ demonstrated high internal consistency (Cronbach's alpha = 0.79). Greater perceived control was associated with less severe asthma, greater asthma self-efficacy, lower perceived asthma severity, lower perceived danger from asthma, and greater perceived usefulness of asthma medicines. Greater perceived control was significantly associated with better asthma-specific quality of life concurrently and 18 and 36 months later, after controlling for demographics, smoking, and severity of asthma. Greater perceived control as also significantly associated with generic mental health outcomes concurrently and 18 and 36 months later, after controlling for covariates. Perceived control was associated with physical function concurrently and 18 months later, but not 36 months later. CONCLUSIONS: The PCAQ is a reliable and valid measure of perceived control of asthma. Perceived control of asthma was associated with both asthma-specific and generic health status outcomes, concurrently and predictively. If perceived control could be modified, better outcomes, particularly better psychologic outcomes, might be achieved for individuals with asthma.     

Work life of persons with asthma, rhinitis, and COPD: A study using a national, population-based sample

Objective  

To estimate the duration of work life among persons reporting a physician's diagnosis of COPD, asthma, or rhinitis compared to those with select non-respiratory conditions or none and to delineate the factors associated with continuance of employment.     

Promoting clinically effective practice: general practitioners' awareness of sources of research evidence

BACKGROUND: Practitioners are being encouraged to base their clinical practice on research evidence. In order to do this, they must be aware of and use the sources of evidence. METHODS: A questionnaire survey was undertaken to establish GPs' awareness of research evidence in their clinical practice and, in fundholding practices, its influence on purchasing plans. Questionnaires were sent to 360 lead fundholders in North Thames Region and 440 of a random sample of the remaining general practitioners in the region for comparison. RESULTS: Questionnaires were returned by 62% of lead fundholders and 63% of GPs in the random sample. There was limited use of the electronic sources of clinical effectiveness. There was greater reported awareness of published sources of research evidence and fundholding GPs were significantly more likely to have referred to publications summarizing research evidence. CONCLUSIONS: GPs seem to make more use of published clinical effectiveness sources than the electronic databases. Consequently, they need educational and technical support if they are to make full use of the available sources of research evidence available in other media.