Biomedical subjects

J C Stout

Publications and source records attributed to J C Stout.

6 recordsLinked to original sources

PubMed1992

Interstitial hybridization sites of the (TTAGGG)n telomeric sequence on the chromosomes of some North American hylid frogs.

Interstitial hybridization sites for the (TTAGGG)n telomeric repeat sequence were present in all seven species of hylid frogs examined and in a triploid hybrid between two of the species. Intra- and interspecific differences and similarities in hybridization sites agreed with what is known about the systematics of these species. Chromosome fusions, fissions, and inversions do not appear to have played a role in the evolution of the interstitial sites for the telomeric repeat in the species examined.

Animals↗

PubMed1990

Corticotropin-releasing factor produces fear-enhancing and behavioral activating effects following infusion into the locus coeruleus.

The present series of experiments tested the hypothesis that the behavioral activating and anxiogenic effects produced by intraventricular administration of corticotropin-releasing factor (CRF) may be mediated by noradrenergic neurons in the brain-stem locus coeruleus (LC). Results showed that infusion of CRF into the LC (100 ng) significantly increased nonambulatory spontaneous motor activity measured in photocell cages; ambulatory (i.e., locomotor) activity was not altered. In the modified Porsolt swim test, which examines arousal and agitation in a stressful situation, significant behavioral activation (i.e., decreased floating) was seen following infusion of CRF (10 ng) into the LC; a 500 ng dose of CRF was necessary to produce similar effects following infusion into the lateral ventricle. The results of these 2 tests suggest that the behavioral activating effects of CRF in the LC may be related to arousing or stress-related effects, rather than to increased locomotor activity per se. Anxiogenic activity was assessed in animals placed in an open field containing a small, darkened compartment. Infusion or CRF into the LC (1-100 ng) significantly increased the time spent in the compartment and decreased the amount of time spent exploring the outside of the compartment or venturing into the inner squares of the open field, all indices of anxiogenic behavior. Biochemical studies showed that bilateral infusion of CRF into the LC produced significant increases in the concentration of the norepinephrine metabolite 3,4-dihydroxyphenylglycol in such forebrain projection areas of the LC as the amygdala and posterior hypothalamus. These data, taken together, suggest that CRF produces its behavioral activating and anxiogenic effects, at least in part, by increasing the activity of LC noradrenergic neurons.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1986

Modulation of cellular immunity in medical students.

This study assessed the psychosocial modulation of cellular immunity in 34 medical-student volunteers. The first blood sample was obtained 1 month before examinations, and the second on the day of examinations. There were significant declines in the percentage of helper/inducer T-lymphocytes, in the helper/inducer-suppressor/cytotoxic-cell ratio, and in natural killer-cell activity in the blood samples obtained on the day of examinations. Half of the subjects were randomly assigned to a relaxation group which met between sample points; the frequency of relaxation practice was a significant predictor of the percentages of helper/inducer cells in the examination sample. Three biochemical nutritional assays (albumin, transferrin, and total iron-binding protein) were within normal limits on both samples. Data from the Brief Symptom Inventory showed significantly increased global self-rated distress associated with examinations in the no-intervention group, compared to nonsignificant change in the relaxation group. Clinical and theoretical implications are discussed.

Adult↗

PubMed1986

Stress depresses interferon production by leukocytes concomitant with a decrease in natural killer cell activity.

This study addressed the effects of a commonplace stressful event on interferon production and natural killer (NK) cell activity and numbers. The quantity of interferons (IFN) produced by concanavalin A stimulated leukocytes obtained from 40 medical students during examinations was significantly lower when compared with IFN levels produced by peripheral blood leukocytes (PBLs) taken 6 weeks earlier (baseline). In addition, three different assays measuring NK cells also showed significant decrements during examinations when compared with baseline samples. These assays included lysis of MOLT-4 target cells, percentage of anti-Leu-7+ (NK) cells, and percentage of large granular lymphocytes. Self-report data documented the significantly greater distress associated with examinations in comparison with baseline samples. The data have implications for immunosuppressive disorders and stress-associated illnesses.

Adult↗

PubMed1985

Stress-related impairments in cellular immunity.

The percentages of total T-lymphocytes (OKT-3+), helper T-cells (OKT-4+), and suppressor T-cells (OKT-8+) were significantly lower in blood samples obtained from 40 medical students during examinations, compared to baseline values obtained 6 weeks earlier. In addition, the response of T-lymphocytes to stimulation by phytohemagglutinin and concanavilin A was also significantly lower during examinations, compared to baseline. Self-report data documented significantly greater distress associated with examinations. The data have implications for immunosuppressive disorders and stress-related illnesses.

Adult↗

PubMedDate not supplied

Marital quality, marital disruption, and immune function.

Marital disruption is associated with significant increases in a variety of psychologic and physical disorders. In order to examine psychologic and physiologic mediators, self-report data and blood samples were obtained from 38 married women and 38 separated/divorced women. Among married subjects, poorer marital quality was associated with greater depression and a poorer response on three qualitative measures of immune function. Women who had been separated 1 year or less had significantly poorer qualitative and quantitative immune function than their sociodemographically matched married counterparts. Among the separated/divorced cohort, shorter separation periods and greater attachment to the (ex)husband were associated with poorer immune function and greater depression. These data are consistent with epidemiologic evidence linking marital disruption with increased morbidity and mortality.

Adult↗