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Biomedical subjects

N H Caskey

Publications and source records attributed to N H Caskey.

12 recordsLinked to original sources
PubMed2000

Bromocriptine reduces cigarette smoking.

AIMS: Animal studies have shown that nicotine releases dopamine, a neurotransmitter implicated in drug reinforcement. We hypothesized that bromocriptine would decrease smoking behavior in humans. DESIGN: The study was conducted double blind and subjects' order of dose exposure was randomized. PARTICIPANTS: The smoking behavior of 20 heavy smokers was recorded for 5 hours after ingesting placebo or one of two doses of bromocriptine (2.50 mg, 3.75 mg) over three sessions (one dose per session). FINDINGS: There was a significant negative linear trend by dosage indicating shorter total puffing time with increasing bromocriptine dosages (p < 0.02). Other significant negative linear trends by increasing dosage include fewer number of puffs, fewer number of cigarettes smoked and mean latency to smoke after 3 hours (expected CMAX on the drug (all ps < 0.05). There was a negative significant linear trend showing decreased plasma nicotine (p < 0.02) and cotinine (p < 0.005) with increasing dosages of bromocriptine. Shiffman/Jarvik Withdrawal Scale (SJWS) cigarette craving subscale scores decreased significantly across increasing dosages (linear trend p < 0.02). There was a significant negative linear trend (p < 0.05) on the Profile of Mood States (POMS) Vigor and Depression subscales, with subjects reporting decreased vigor and depression with increasing bromocriptine doses. No other mood effects were observed. CONCLUSION: These results support the hypothesis that dopaminergic mechanisms mediate cigarette smoking reinforcement.

Adolescent↗
PubMed1999

The effects of dopaminergic D2 stimulation and blockade on smoking behavior.

Researchers have hypothesized that dopamine mediates the reinforcing effects of stimulant drugs, including nicotine. Three experiments tested whether manipulating dopamine would alter human smoking behavior. Experiments used double-blind, repeated measures designs. In Experiment 1, 4 participants were given haloperidol (a dopamine antagonist; placebo, 0.5, and 1.0 mg) on 3 occasions. The smoking rate was faster in the 1.0 mg versus the placebo condition. In Experiment 2, 12 participants were given haloperidol (2.0 mg) and placebo on 2 occasions. The intercigarette interval was shorter at the expected time of peak drug concentration. In Experiment 3, 5 participants were given bromocriptine (a dopamine agonist, 2.5 mg) and placebo on 2 occasions. The smoking rate was significantly slower with bromocriptine. These results suggest that blockade of D2 receptors increases smoking whereas their stimulation decreases smoking.

Adult↗
PubMed1995

Predictors of homeless veterans' irregular discharge status from a domiciliary care program.

This study addresses the relationship of homeless veterans' discharge status from a domiciliary care program to biopsychosocial characteristics presented at admission into the program. Hypotheses were that younger age, less education, and substance abuse or psychiatric disorder would predict an irregular discharge. Research participants were 367 homeless male veterans who had been admitted to a domiciliary care program at the West Los Angeles Veterans Affairs Medical Center for treatment of medical, psychiatric, or substance disorders. Status of veterans' program discharge (regular or irregular) served as the outcome measure. Logistic regression analysis revealed that irregular discharge from the program was more likely among veterans who were black, who had poor employment histories, or who had problems with alcohol. Results are discussed in light of the need to maintain homeless veterans in treatment programs so that they can achieve maximum benefit from available programs.

Alcohol Drinking↗
PubMed1995

Homeless veterans' utilization of medical, psychiatric, and substance abuse services.

This study focuses on the association between homeless veterans' prior utilization of medical, psychiatric, and substance abuse services and biopsychosocial characteristics reported at admission into a domiciliary care program. Given the large number of veterans in the US homeless population and their health care needs, understanding factors associated with health service use among homeless veterans is significant. Research participants were 429 homeless male veterans who had been admitted to the Domiciliary Care for Homeless Veterans Program site at the West Los Angeles Veterans Affairs Medical Center between February 1988 and July 1992 for treatment of medical, psychiatric, or substance disorders. Results of logistic regression analyses indicated that self-reported need (chronic medical problems, serious psychiatric symptoms, combat stress, alcohol use) and evaluated need for care (evidence of liver dysfunction) were important to veterans' use of health services in the 6 months before program admission. Predisposing social structure factors (education, residential stability, and usual sleeping place) were also significant predictors of service utilization. Overall, need factors were more strongly related to service use. Supplementary logistic regression analyses indicated that comorbidity of need factors deserves attention in understanding homeless veterans' use of services. In conclusion, it is important to attend to predisposing social structure factors as potential barriers to care for homeless veterans.

Comorbidity↗
PubMed1995

Menthol vs nonmenthol cigarettes: effects on smoking behavior.

OBJECTIVES: The purpose of this study was to examine intraindividual differences in smoking behavior between smoking regular and mentholated cigarettes. METHODS: Healthy male smokers (n = 29) smoked either a regular or a mentholated cigarette in two separate sessions 1 week apart. Commercial brands with comparable tar, nicotine, and CO content were used. Smoking behavior was constrained by fixed 15-second interpuff intervals, but puff volume and number of puffs were unconstrained. RESULTS: When smoking the non-mentholated brand of cigarettes, participants smoked 22% more puffs and had 13% higher mean volumes per puff than they did when smoking the mentholated brand of cigarettes. The aggregate 39% excess exposure to cigarette smoke in the regular-cigarette condition was not accompanied by commensurate excesses in expired carbon monoxide or in physiological measures normally correlated with nicotine exposure. CONCLUSIONS: These findings parallel differences in physiological correlates of exposure to nicotine found in cross-sectional comparisons of African-American and White smokers and are consistent with the results of emerging laboratory investigations.

Adult↗
PubMed1994

Mentholated cigarettes decrease puff volume of smoke and increase carbon monoxide absorption.

The influence of mentholated vs. regular cigarettes on selected chemical and topographic parameters was measured in 20 smokers in a pulmonary function laboratory. Half the subjects were black and half were white; half were menthol and half regular smokers. All subjects smoked both types of cigarettes, one on each of 2 days. Compared to regular cigarettes, mentholated cigarettes produced a significantly greater boost in carbon monoxide measured as both blood carboxyhemoglobin and end-expired carbon monoxide, despite the fact that mentholated cigarettes decreased average and total cumulative puff volumes and increased mean puff flow rates of inhaled smoke. These chemical and topographic differences were independent of race. No significant differences in depth of inhalation of the smoke or in the amount of insoluble smoke particulates delivered to or retained in the respiratory tract were noted between the two types of cigarettes. Mentholation of cigarettes may decrease volume of smoke inhaled but appears to increase exposure of smokers to toxic effects of carbon monoxide.

Adult↗
PubMed1993

Rapid smoking of menthol and nonmenthol cigarettes by black and white smokers.

White subjects took significantly more puffs of cigarette smoke before stopping than did black subjects in a modified, controlled-dose rapid smoking procedure. Paradoxically, however, no racial differences were detected for changes in carbon monoxide levels, or changes in cardiovascular variables (systolic and diastolic blood pressure, and heart rate). Due to the cooling and topical anesthetic properties of menthol, it was hypothesized that menthol and regular cigarette smokers would take more puffs from menthol cigarettes than from regular cigarettes before stopping in the controlled-dose rapid smoking procedure. However, no difference was observed for the number of puffs taken from regular as opposed to menthol cigarettes (cigarette type condition) and no differences were found for Cigarette Preference (regular smokers vs. menthol smokers).

Adult↗
PubMed1991

The effects of smoking-related sensory cues on psychological stress.

Previous studies have shown that the sensory cues of cigarette smoking are important for smoking satisfaction and craving reduction. Sensory cues in the absence of pharmacological doses of nicotine have been found to be moderately satisfying and to reduce craving. The current study was conducted to determine if administration of the sensory cues of cigarette smoking with minimal nicotine would also provide relief from mild anxiety associated with anticipation of a difficult anagram test. This test has previously been shown to be sensitive to the anxiety relieving effects of cigarette smoking. Compared to the placebo control condition, the sensory condition caused a significant alleviation of the stress as measured by components of the Spielberger scale for anxiety. The addition of cigarette smoke containing 0.5 mg of nicotine to the sensory cues caused a slight though nonsignificant enhancement of the stress alleviation. These results demonstrate that sensory cues of smoking can provide similar effects as nicotine containing cigarettes with regard to stress alleviation. Previous studies had shown that sensory cues are important for the consumptive aspects of smoking (i.e., smoking satisfaction and craving reduction). The current study shows that sensory cues are important for other effects of smoking as well.

Adolescent↗
PubMed1989

Anxiolytic effects of smoking associated with four stressors.

There is a widespread belief that cigarette smoking alleviates stress. The literature reveals conflicting results on the anxiolytic effects of smoking. This study was designed to replicate a report that smoking (a) reduced subjective anxiety induced by stressful anagrams and (b) increased pain threshold for a cold pain task. This study (N = 15) included two other stressors: white noise and an auditory vigilance task. A significant Time x Condition (smoking vs. deprived) interaction was found for Spielberger State Anxiety Inventory scores in the anagram task. A borderline significant interaction effect was found for the cold pain task. No significant effects were found with the two other tasks. These results provide partial support for the popular notion that smoking mitigates stress-induced anxiety. No difference was found between the smoking and deprived conditions for either pain threshold or pain endurance.

Adaptation, Psychological↗
PubMed1984

Dual perspectives: clients' and therapists' perceptions of therapist responses.

This study compares clients' and therapists' perceptions of individual therapist responses. Three segments of four responses each were sampled from early, middle, and late in actual therapy sessions with 16 client-therapist pairs. Using interpersonal process recall, both therapists and clients independently described their perceptions of the therapist's response intentions in their own session. They also rated the impact of therapist responses according to four variables, including response helpfulness and therapist empathy. Client-therapist agreements on intentions and impacts were computed using indices of both covariation and mean difference. Clients' and therapists' response-by-response reports of therapist intention were positively associated, but their average ratings for the session were not. On the other hand, their response-by-response ratings of impact were not associated, but their average ratings of helpfulness and affective impact were. Correlates of agreement were also studied. Contrary to expectations, length of therapeutic relationship was not correlated with client-therapist agreement: in fact, there was a trend toward lower agreement for client-therapist pairs of longer duration. Therapist experience also did not predict client-therapist agreement.

Adolescent↗