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Biomedical subjects

A O'Leary

Publications and source records attributed to A O'Leary.

18 recordsLinked to original sources
PubMed1992

Predictors of safer sex on the college campus: a social cognitive theory analysis.

In April and May 1989, the authors surveyed a sample of students enrolled on four college campuses in New Jersey (N = 923) concerning their HIV transmission-related behavior, knowledge, and a variety of conceptual variables taken primarily from social cognitive theory that were thought to be potentially predictive of safer sexual behavior. Analyses of sexually active, unmarried students' responses indicated that men expected more negative outcomes of condom use and were more likely to have sexual intercourse while under the influence of alcohol or other drugs, whereas women reported higher perceived self-efficacy to practice safer sex. Regression analyses indicated that, among the factors assessed, stronger perceptions of self-efficacy to engage in safer behavior, expecting fewer negative outcomes of condom use, and less frequency of sex in conjunction with alcohol or other drug use significantly predicted safer sexual behavior. Enhanced self-efficacy to discuss personal history with a new partner was associated with a greater number of risky encounters. Implications of these findings for intervention efforts with students are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Adaptation to form distortion of a familiar shape.

Adaptation to the shape distortion produced by an arrangement of cylindrical lenses was demonstrated. Adaptation was produced by exposing subjects to a series of photographs of faces, which appeared horizontally stretched when seen through the lens arrangement. A 16-min adaptation procedure caused a change when the width of a test face was gradually varied and the subject indicated that it looked normal. An alteration in the perceived shape of a test face and an ellipse was also demonstrated when subjects gave estimates of the height and width of these test objects. These studies provide evidence for the operation of memory representations as the veridical cue in process assimilation.

Adaptation, Ocular↗
PubMed1990

Impact of perceived self-efficacy in coping with stressors on components of the immune system.

This experiment examined the impact of experimentally varied perceived self-efficacy in exercising control over stressors on components of the immunological system. Immunological changes while coping with phobic stressors were measured within an intrasubject control design that included a baseline phase, an efficacy-acquisition phase, and a maximal-efficacy phase. In each of these phases, perceived coping self-efficacy, level of autonomic and endocrine activation, and several components of the immunological system were measured. Development of strong perceived self-efficacy to control phobic stressors had an immunoenhancing effect. A slow growth of perceived self-efficacy, heart rate acceleration, and cortisol activation attenuated immunological system status during the efficacy-acquisition phase. Rapid growth of perceived self-efficacy also predicted maintenance of immunoenhancement during the maximal perceived self-efficacy phase.

Adaptation, Psychological↗
PubMed1990

Stress, emotion, and human immune function.

This article provides a review of empirical evidence linking emotional processes to immune function in humans. Acute stressors have produced mixed effects on immunity, presumably through differential activation of physiological stress systems. Chronic stress has been associated with suppression of immune function, and there is evidence that the immune system may not adapt over time. Effects of stress accompanying social disruption and psychological depression, when demonstrated, have been consistently adverse. Certain personality styles may enhance or degrade immune response. Relationships between psychosocial factors and immunity have been identified for several diseases, including cancer, acquired immune deficiency syndrome, and autoimmune diseases; psychosocial interventions have been tested with variable results. Theoretical and methodological considerations are summarized and directions for future research suggested.

Acquired Immunodeficiency Syndrome↗
PubMed1988

A cognitive-behavioral treatment for rheumatoid arthritis.

This experiment tested a cognitive-behavioral rheumatoid arthritis treatment designed to confer skills in managing stress, pain, and other symptoms of the disease. We hypothesized that a mediator of the magnitude of treatment effects might be enhancement of perceived self-efficacy to manage the disease. It was predicted that the treatment would reduce arthritis symptoms and possibly would improve both immunologic competence and psychological functioning. The treatment provided instruction in self-relaxation, cognitive pain management, and goal setting. A control group received a widely available arthritis helpbook containing useful information about arthritis self-management. We obtained suggestive evidence of an enhancement of perceived self-efficacy, reduced pain and joint inflammation, and improved psychosocial functioning in the treated group. No change was demonstrated in numbers or function of T-cell subsets. The magnitude of the improvements was correlated with degree of self-efficacy enhancement.

Adult↗
PubMed1987

Perceived self-efficacy and pain control: opioid and nonopioid mechanisms.

In this experiment, we tested for opioid and nonopioid mechanisms of pain control through cognitive means and the relation of opioid involvement to perceived coping efficacy. Subjects were taught cognitive methods of pain control, were administered a placebo, or received no intervention. Their pain tolerance was then measured at periodic intervals after they were administered either a saline solution or naloxone, an opiate antagonist that blocks the effects of endogenous opiates. Training in cognitive control strengthened perceived self-efficacy both to withstand and to reduce pain; placebo medication enhanced perceived efficacy to withstand pain but not reductive efficacy; and neither form of perceived self-efficacy changed without any intervention. Regardless of condition, the stronger the perceived self-efficacy to withstand pain, the longer subjects endured mounting pain stimulation. The findings provide evidence that attenuation of the impact of pain stimulation through cognitive control is mediated by both opioid and nonopioid mechanisms. Cognitive copers administered naloxone were less able to tolerate pain stimulation than were their saline counterparts. The stronger the perceived self-efficacy to reduce pain, the greater was the opioid activation. Cognitive copers were also able to achieve some increase in pain tolerance even when opioid mechanisms were blocked by naloxone, which is in keeping with a nonopioid component in cognitive pain control. We found suggestive evidence that placebo medication may also activate some opioid involvement. Because placebos do not impart pain reduction skills, it was perceived self-efficacy to endure pain that predicted degree of opioid activation.

Female↗
PubMed1986

Trimoprostil plasma concentration-gastric acid inhibition relationships in duodenal ulcer patients.

The effect of single 0.25 mg, 0.75 mg, 1.5 mg, and 3.0-mg oral doses of trimoprostil and placebo on the inhibition of meal-stimulated gastric acid secretion was investigated in duodenal ulcer patients. Drug and placebo were administered in a double-blind, randomized, crossover study under fasting conditions. A bactopeptone meal was administered 30 minutes after dosing. Gastric acid output was measured by intragastric titation (pH 5.5) and trimoprostil plasma concentrations were measured by a specific gas chromatography-negative chemical ionization-mass spectrometric method. Meal-stimulated gastric acid secretion was significantly reduced when compared to placebo for one hour after 0.25 mg, 1.5 hours after 0.75 mg, and for 2.5-3.0 hours after both 1.5 mg and 3.0 mg doses. The maximal inhibition of gastric acid ranged from 65% reduction after 0.75 mg to 74% after 1.5 mg to 82% after 3.0-mg doses. Trimoprostil was rapidly absorbed and eliminated; terminal elimination half-life ranged from 21 to 45 minutes. Both maximum concentration and area under the plasma concentration-time curve increased proportionately with an increase in the dose. The concentration-effect data at a given dose were simultaneously fit to a pharmacokinetic/pharmacologic effect model. An IC50 (plasma concentration needed to elicit a 50% inhibition effect) value of 0.2 ng/mL was observed at doses of 0.75 mg to 3.0 mg. Overall, trimoprostil was effective in inhibiting acid output in a dose-related manner in duodenal ulcer patients.

Adult↗