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Biomedical subjects

R W Pickens

Publications and source records attributed to R W Pickens.

At least 55 records · Page 3Linked to original sources
PubMed1988

Needle sharing among intravenous drug abusers: future directions.

In summary, the conference focused on one means of HIV transmission among intravenous drug abusers: exposure through the sharing of drug injection equipment. The participants emphasized the urgency of the AIDS epidemic among intravenous drug abusers. A massive effort is needed now to prevent further spread of the disease. The prevention of AIDS requires a multipronged approach to reach intravenous drug abusers, with various motivations for behavior change: Communities across the United States should quickly implement programs to educate addicts regarding their risk for AIDS and how they may reduce their risk. Aggressive outreach is a key educational tool. Drug abuse treatment is an important means of combating the AIDS epidemic among intravenous drug abusers who wish to quit using drugs and are willing to enter treatment. Resources need to be expanded so that drug abuse treatment is readily available. Since a substantial number of intravenous drug abusers will continue to inject drugs, an effective AIDS prevention strategy must encourage these individuals not to share injection equipment and must provide clear and explicit information on how they can clean their injection equipment to decrease the likelihood of HIV transmission if they continue to share. Public policies that restrict the availability of needles and thereby encourage needle sharing should be reexamined. As part of this reexamination, research should be conducted to determine the effectiveness of needle exchange programs that provide intravenous drug abusers with sterile needles in exchange for used needles.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Smoking topography in a nonlaboratory environment.

The relationships between the number of cigarettes smoked/day and the number of puffs/cigarette, puff duration, and total puff time/cigarette were studied. Data were collected on 12 regular smokers for all cigarettes smoked over a 3-day period in a nonlaboratory environment. Between-subject variability was substantial on each of the topographical measures. Neither the number of cigarettes smoked per day nor the classification of Heavy (greater than 25 cigarettes/day) vs Moderate (less than 25 cigarettes/day) smoking levels was related to the intensity with which cigarettes were smoked. Within-subject consistency on the topography measures indicates that smokers may have relatively unique smoking patterns.

Adult↗
PubMed1986

Sex differences in tobacco withdrawal syndrome.

Prospective data from an inpatient (n = 20) and outpatient (n = 50) study were examined for sex differences in tobacco withdrawal symptoms. With each subject serving as his/her own control, changes in a wide range of physiological, psychological and behavioral measures were determined from baseline to tobacco abstinence condition. For all 46 measures, no statistically significant differences between men and women were found in either the number or severity of tobacco withdrawal symptoms.

Chewing Gum↗
PubMed1986

Smoking behavior of type A and type B smokers.

Retrospective surveys have compared smoking between Type A and Type B individuals; however, prospective studies using objective measures have not been reported. In Study 1, we used an ambulatory smoking recorder to compare the smoking behavior of Type A and Type B smokers. Individual smoking behaviors and the derived tobacco and nicotine exposures were similar for Type A and Type B smokers. In Study 2, we compared serum nicotine before and after smoking a cigarette between Type A and Type B smokers. Pre-cigarette and post-cigarette nicotine levels and nicotine boost were similar for Type A and Type B smokers. We conclude that Type A and Type B smokers do not differ in smoking behavior or tobacco and nicotine intake.

Adult↗
PubMed1985

Measurement of reinforcement in depression: a pilot study.

We tested whether performance on a progressive ratio schedule of reinforcement with increasing magnitudes of monetary reward could be used as a behavioral measure of response to reinforcement during depression. Performance on the task was recorded before, during and after treatment of depression in six melancholic patients. The amount of money earned and the number of responses to obtain money during the task increased in the three subjects who improved with treatment but did not increase in three subjects who did not improve. In addition, the degree to which responses increased with increasing monetary reward became greater in two of the three subjects who improved but in none of the subjects who did not improve. Methodological liabilities (e.g., the small sample size and absence of a control group) may limit the validity of our findings. Our results do suggest performance of the task may be an objective measure of response to reinforcement that could be used in both basic and clinical research on depression.

Adolescent↗
PubMed1985

Blood nicotine, smoke exposure and tobacco withdrawal symptoms.

The relationship between tobacco withdrawal symptoms and pre- and post-cigarette blood nicotine levels, pre-cigarette cotinine levels, change in nicotine level from pre- to post-cigarette, half-life for nicotine, and total smoke exposure was examined in 20 smokers. Subjects' reports of craving for cigarettes were significantly related to blood nicotine/cotinine levels and change in nicotine level from pre- to post-cigarette; questionnaire measures of confusion and number of awakenings during sleep was related to half-life for nicotine; and number of awakenings during sleep was related to behavioral measures of total smoke exposure. These results suggests some symptoms of tobacco withdrawal are related to nicotine deprivation while others are not.

Adult↗
PubMed1985

Temporal patterns of smoking topography in the natural environment.

Temporal patterns of smoking topography were studied in the natural environment. Six smokers smoked all cigarettes over a 10-day period using a small portable electronic recording device which allowed the measurement of a number of aspects of smoking topography. When the data were averaged in 2-hour blocks across the 10-day smoking period, all subjects except one showed differences in smoking topography as a function of time of day. There was considerable intersubject variability in the aspects of smoking topography which varied over the smoking day, and subjects also differed in the pattern of changes seen.

Adult↗
PubMed1985

Instructions control whether nicotine will serve as a reinforcer.

Three studies examined self-administration of nicotine among exsmokers given concurrent access to nicotine (2 mg) and placebo gums during the first 2 weeks of abstinence from smoking. In Study 1 subjects were told they would receive either nicotine or placebo gum. With this instructional set, nicotine served as a reinforcer; i.e., subjects consistently self-administered nicotine but not placebo gum. However, subjects could discriminate gums on the basis of side-effects; thus, the ability of nicotine to serve as a reinforcer may have been due, not to its psychoactive effects, but rather because subjects believed the gum with more side-effects to be the active gum. In Study 2 we attempted to change this belief by telling subjects they would receive either the marketed nicotine gum or a new nicotine gum that is as effective as the marketed gum but has less side-effects (i.e., placebo). In Study 3 we attempted to change the belief by telling subjects that placebo gum had more side-effects than nicotine gum. With these two instructional sets, the stimulus properties of nicotine did not serve as reinforcer; i.e., subjects self-administered equal amounts of nicotine and placebo gums. To our knowledge, this is the first demonstration that instructions can control whether a drug will serve as a reinforcer.

Discrimination Learning↗
PubMed1984

Effect of nicotine on the tobacco withdrawal syndrome.

This study tested the ability of nicotine to alleviate the tobacco withdrawal syndrome. Signs and symptoms of tobacco withdrawal were measured in 100 smokers who fulfilled DSM-III criteria for tobacco dependence and a past history of tobacco withdrawal. After 2 evenings of baseline measurement, subjects were randomly assigned to receive either nicotine or placebo gum in a double blind manner. Subjects then stopped smoking, chewed gum freely, and returned on the 1st, 2nd, and 4th evenings of abstinence for further measurement. Nicotine reduced the increase in irritability, anxiety, difficulty concentrating, restlessness, impatience, and somatic complaints that subjects reported after cessation. Reductions in these withdrawal symptoms by nicotine were confirmed by ratings of significant others and by subjects' scores on the Profile of Mood States. Nicotine did not reduce the increases in cigarette craving, hunger, eating, insomnia, tremulousness , or supine heart rate after cessation. The effects of nicotine occurred immediately and persisted throughout the study. Although many subjects correctly identified their drug group, the efficacy of the gum was independent of subjects' identifications of drug. The relief of tobacco withdrawal by nicotine gum suggests that the tobacco withdrawal syndrome is caused, in part, by nicotine deprivation.

Adult↗
PubMed1984

Tobacco withdrawal symptoms: an experimental analysis.

This study was a prospective examination of tobacco withdrawal symptoms in a controlled environment. Smokers (N = 27) were hospitalized for a 7-day period during which a battery of tests was administered. Smokers were assigned to either an experimental group (N = 20) or a control group (N = 7). Subjects in the experimental group smoked ad libitum for a 3-day baseline period and then underwent 4 days of tobacco deprivation. Subjects in the control group continued to smoke ad libitum throughout the study. Of the 37 measures of tobacco withdrawal employed in this study, nine showed significant changes following tobacco deprivation. These changes include decreased heart rate and increased caloric intake, weight, craving for tobacco, confusion, depression-dejection, number of awakenings, duration of awakenings, and increased poor concentrations as observed by others.

Adult↗
PubMed1984

Consistency of the tobacco withdrawal syndrome.

The consistency of the tobacco withdrawal syndrome across repeated periods of abstinence was tested using a modified A-B-A-B design. The large majority of the signs and symptoms of tobacco withdrawal occurred during abstinence, returned to baseline, and then recurred during a second abstinence period. This finding suggests that the syndrome is reliable and can be studied with within-subject designs.

Humans↗
PubMed1983

Diazepam dose preference in humans.

Diazepam dose preference was studied in 10 human subjects in a hospital setting. Subjects were allowed to select between a standard compound (diazepam or pentobarbital) and one of several doses of diazepam (2-40 mg/capsule) on an ad lib basis. When 5 or 10 mg/capsule diazepam was the standard, no clear cut diazepam dose preference was found. When 30 or 50 mg/capsule pentobarbital was the standard, clear cut diazepam dose preference in some subjects was found. The shape of the dose preference function differed among subjects. Within subjects, diazepam dose preference differed within the self-administration day, with some subjects preferring one dose in the morning and a different dose later in the day.

Adult↗
PubMed1983

Relation of puff volume to other topographical measures of smoking.

Puff volume, puff duration, interpuff interval, cigarette interval, puffing rate, and number of puffs per cigarette were recorded in eight normally smoking subjects during five daily one-hour laboratory sessions. Topographical measures showed wide variability across subjects, but measures were relatively stable within subjects. Puff volume was significantly positively correlated with puff duration for five subjects. As the cigarette was smoked, puff duration remained relatively constant, while puff volume decreased systematically and interpuff interval increased initially and then decreased.

Adult↗