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Biomedical subjects

D White

Publications and source records attributed to D White.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

Etiology of anovulation in polycystic ovary syndrome.

Various endocrine factors may contribute to the phenomenon of arrested follicular development, which is the hallmark of anovulatory infertility in polycystic ovary syndrome. Hypersecretion of luteinizing hormone and/or insulin, together with high intrafollicular concentrations of androgens, can interact to produce supraphysiological levels of cyclic AMP in granulosa cells, resulting in premature activation of terminal differentiation and, hence, arrest of follicle growth.

Anovulation↗
PubMedDate not supplied

Regret is what you get: the effects of manipulating anticipated affect and time perspective on risky single-occasion drinking.

This study tested anticipated affect as a potential strategy for reducing risky single-occasion drinking (RSOD). The hypothesis was that asking respondents to focus on their anticipated affect following RSOD would lead to higher ratings of negative affect than those obtained when asking respondents to focus on their feelings towards RSOD. In turn, these negative affect ratings were hypothesized as leading to safer behavioural estimates and reductions in RSOD. The study is based on a self-report questionnaire administered at two time points. At Time 1, measures of past drinking and demographic information were collected, along with affect ratings of drinking within safer single-occasion limits and affect ratings of RSOD (within-subjects condition). Time perspective was manipulated whereby the experimental group was asked to focus on affective reactions after RSOD and the control group to focus on affective reactions towards RSOD (between-subjects condition). Two weeks later, drinking behaviour was measured. The findings showed that the time perspective manipulation resulted in significantly higher negative affect ratings in the feeling after condition than in the feeling towards condition. Further, females reported lower negative affect than males. No other main or interaction effects were found. The time perspective manipulation, however, failed to produce safer behavioural estimates and RSOD reduction at follow-up. No significant differences were found between ratings of negative affect when drinking within safe limits as compared with ratings of affect when drinking above such limits. Despite greater negative affect 'after' rather than 'toward' the target behaviour, anticipated affect following RSOD did not yield safer behavioural estimates and subsequent drinking reduction at follow-up. These findings are interpreted in the context of risk perception associated with RSOD. The implications of this study for design of interventions aimed at reducing RSOD are discussed. In particular, ways of intensifying negative affect for RSOD are considered.

Adult↗
PubMedDate not supplied

Pituitary-gonadal function during sleep in men with erectile impotence and normal controls.

Studies of pituitary-gonadal function in men with erectile disorders have provided conflicting findings. This study compares blood LH and testosterone during sleep in 17 physically healthy men with erectile impotence and 12 matched normal controls, and relates hormonal variations to stages of sleep and penile tumescence. Subjects, aged 23-36 were studied in a sleep laboratory for 3-6 nights with the last two nights devoted to sequential blood sampling every 20 minutes. Five men had never been able to achieve intercourse (primary impotent group) and 12 suffered from a life-long history of intermittent erectile failures (secondary-impotent group). There were no significant differences in sleep duration and REM time among the impotent groups and normal controls. Primary-impotent men showed half as many full tumescent episodes as secondary-impotent men and controls, and spent significantly less time above 80% of full tumescence. The secondary-impotent group did not differ in nocturnal penile tumescent measures from controls. There was a pattern of irregularly occurring fluctuations in plasma LH and testosterone with no differences among groups in frequency and amount of peak hormonal increases. Normal subjects had significantly higher mean testosterone concentrations during REM sleep than during other sleep stages, and during full tumescence than during partial and nontumescent periods. A direct causal relation between REM-related activity and circulating testosterone was not supported by the observation that the hormonal levels during REM sleep and during full tumescence did not differ statistically from the levels measured during adjacent time periods. As with normal subjects, the secondary-impotent group exhibited higher testosterone levels during REM sleep and full tumescence; by contrast, the primary-impotent group did not show significant hormonal differences across stages of sleep and tumescent/ nontumescent periods. These data are discussed with respect to the possible existence of subgroups of impotent men without known organic pathology than may be characterized by psychophysiologic and endocrine differences during sleep.

Adult↗
PubMedDate not supplied

Pituitary-gonadal function during sleep in men with hypoactive sexual desire and in normal controls.

There is virtually no information on the psychobiology of hypoactive sexual desire (HSD) in men. This study compares pituitary and gonadal hormones and nocturnal penile tumescence (NPT) during sleep in 17 physically healthy men with HSD and 17 age-matched, nondysfunctional volunteers. There were six HSD men with problems of sexual arousal and 11 with secondary erectile impotence. The subjects, aged 27-55, were studied in a sleep laboratory for 4 nights with the last night devoted to sequential blood sampling every 20 min. The total group of HSD men had significantly lower plasma testosterone, measured hourly through the night, than controls, and there was a positive relation between testosterone and frequency of sexual behavior. There were no differences in free testosterone, prolactin, luteinizing hormone (LH), and estradiol between the HSD and control groups. The NPT parameters of HSD men with secondary impotence were consistently and significantly lower than the nondysfunctional men. These data are discussed with respect to the role of gonadal hormones in male sexual function, the significance of NPT as a window to central biologic events, and to possible heterogeneity of men with hypoactive sexual desire.

Adult↗
PubMedDate not supplied

The relationship between pituitary-gonadal function and sexual behavior in healthy aging men.

Few studies have assessed the role of pituitary and gonadal hormones on age-related changes in sexual behavior in healthy men. We conducted a retrospective and prospective evaluation of sexual function and behavior in 77 healthy married men aged 45 to 74 years. The subjects were studied in the sleep laboratory for four nights with the last night devoted to sequential blood sampling every 20 minutes. Significant age-related decreases in sexual desire, sexual arousal and activity, and increases in erectile problems were noted. Aging was negatively correlated with bioavailable testosterone (bT), was positively correlated with luteinizing hormone (LH), and was not related to total testosterone, estradiol, and prolactin. Bioavailable testosterone, and the ratio of bT over LH showed a close association with several sexual behavior dimensions while total testosterone, estradiol, and prolactin demonstrated few or no behavioral relationships. The age-related effect of bT was, however, a more important determinant of the reported behavioral differences than were the effect of bT independent of age. There was no evidence that changes in circulating hormones contribute to erectile disorders in healthy aging men.

Age Factors↗
PubMedDate not supplied

Angiotensin converting enzyme and substance P changes in blister fluid following afferent nerve stimulation in the rat.

We have examined the effect of electrical nerve stimulation on substance P and angiotensin converting enzyme activity in the interstitial fluid of rat skin using a blister model. Following sciatic nerve stimulation, blister fluid immunoreactive substance P (fmol/ml) was increased from 118 (unstimulated side, s.e.m. = 13, n = 15) to 197 (stimulated side, s.e.m. = 26, n = 15, P less than 0.0125, paired t-test, 14 d.f.). Angiotensin converting enzyme (ACE) activity (nmol HL/ml per h) was reduced in blister fluid from 26.5 (unstimulated side, s.e.m. = 2.4, n = 12) to 22.4 (stimulated side, s.e.m. = 1.4, P less than 0.05, paired t-test, 11 d.f.). Electrical stimulation of afferent nerves inhibits angiotensin converting enzyme activity in vivo. This may contribute to the process of neurogenic inflammation.

Animals↗
PubMedDate not supplied

Glycosylated haemoglobin in uraemia.

Glycosylated haemoglobin (GHb) was measured in 71 patients with stable chronic renal failure by the thiobarbituric acid (TBA) reaction and by agar gel electrophoresis. Nineteen patients were diabetic. Of the non-diabetics, 22 were treated conservatively (including 8 children), 15 by maintenance haemodialysis, and 15 by continuous ambulatory peritoneal dialysis. GHb measured by both methods correlated with postprandial blood glucose levels. There was a significant discrepancy between the two methods only in patients with serum urea concentrations greater than 30 mmol/l, mean +/- SD, (6.8 +/- 2.6% vs 8.2 +/- 2.5% for TBA and electrophoresis, respectively). This difference, delta GHb, correlated with serum urea, serum creatinine, and serum bicarbonate, but after logistic regression of results from all 71 patients only serum urea was associated with delta GHb. Lower haemoglobin and GHb and high fetal haemoglobin concentrations in the haemodialysis group suggested increased haemolysis in these patients. Measurement of GHb by the TBA method and by agar gel electrophoresis remain useful indicators of hyperglycaemia in patients with mild, stable chronic renal failure.

Adolescent↗
PubMedDate not supplied

Anonymized sero-survey of HIV in a genitourinary medicine clinic population.

An anonymized sero-survey of the prevalence of HIV antibody was performed at an inner city Genitourinary medicine clinic in Birmingham. In 1991 8686 patients undergoing routine serological syphilis tests were anonymously tested for HIV antibodies once during the year. Demographic information was recorded for each sample but they were otherwise unlinked. There were 31 samples which tested positive for anti-HIV 1 from this group compared with 13 diagnosed by concomitant voluntary named testing. Sero-prevalence rates of 0.17% for women and heterosexual men and 4.37% for homosexual/bisexual men were found. No drug users tested positive. The survey provided evidence of occult disease outside the recognized risk behaviour patterns of homosexual men and injecting drug users outside London.

AIDS Serodiagnosis↗
PubMedDate not supplied

Low-frequency positive pressure ventilation with extracorporeal carbon dioxide removal (LFPPV-ECCO2R): an experimental study.

We describe a new form of mechanical pulmonary ventilation, low-frequency positive pressure ventilation with extracorporeal CO2 removal (LEPPV-ECCO2R). In a series of animal studies the rate of mechanical ventilation was 0.66, 1, 2, and 4 min-1 at a tidal volume of 3, 10, and 15 ml kg-1. We were able to maintain normal blood gases and normal lung volumes and lung mechanics even at the lowest ventilator rate with tidal volumes of 10 or 15 ml kg-1. Each experiment lasted 7 hours. Our data suggest a possible new dimension in the management of a difficult patient on mechanical pulmonary ventilation.

Animals↗
PubMedDate not supplied

Antibody to sin nombre virus in rodents associated with peridomestic habitats in west central Montana.

Most human cases of hantavirus pulmonary syndrome are acquired in the peridomestic environment, yet studies of the ecology and infection dynamics in the reservoir host, the deer mouse (Peromyscus maniculatus), have focused on sylvan populations. We describe a 2.5-year study of hantavirus infection in rodents associated with peridomestic habitats in west central Montana. Antibodies reactive with Sin Nombre virus (SNV) were found in five species. Overall SNV antibody prevalence was highest among deer mice (25% of individuals tested). As has been demonstrated for sylvan populations, the antibody-positive component of the deer mouse population consisted of a higher proportion of adults and males. However, the prevalence of antibodies to SNV was higher in this study than has been reported in most sylvan studies. The average monthly proportion of deer mouse blood samples with antibodies to SNV ranged from approximately 20% to 25% and was highest in the late spring/early summer. The higher SNV antibody prevalence in peridomestic compared with sylvan settings may be related to behavioral differences and/or potentially longer survival of the virus deposited inside buildings. Peridomestic settings presented higher concentrations of virus and may present a higher risk of human infection than do sylvan settings.

Animals↗
PubMedDate not supplied

Education and training of occupational therapists for neonatal intensive care units.

OBJECTIVE: The neonatal intensive care unit (NICU) is an area in which occupational therapists require specialized advanced training and skills. The purpose of this study was to evaluate the nature of current practice among occupational therapists in NICU settings, their training, and their opinions regarding educational experiences necessary for NICU work. METHOD: One hundred seventy-four NICU occupational therapists completed a survey questionnaire designed to elicit information about these issues. RESULTS: The majority of respondents were engaged in similar practice duties in NICUs, most of which had been using therapy services for less than 10 years. Most of the respondents (83%) reported that their primary source of training was on the job rather than through formal course work or training programs. Many of the respondents (40%) lacked training in the use of any infant assessments, and 50% had 2 years or less of pediatric work experience before entering practice in the NICU. The respondents indicated that mentored experience, on-the-job training, pediatric work experience, extended continuing education courses, and formal internships could prove helpful to future occupational therapists who wish to acquire the knowledge and skills to become competent in the NICU. CONCLUSION: Results of the survey indicate that current training and education to work in an NICU is inadequate and needs to be addressed. Occupational therapists working in NICUs desire and express the need for specialized training to work in this practice area. A more aggressive effort toward standard NICU education and training is necessary to ensure that occupational therapists are competent members of the NICU team.

Adult↗
PubMedDate not supplied

Factors influencing enrollment in a physiotherapy degree-completion program in Atlantic Canada: a survey.

The purpose of this study was to identify factors that influence enrollment in Dalhousie University's BSc (PT) degree-completion program. A geographically stratified, random sample of 100 nondegree physiotherapists practising in Atlantic Canada was surveyed by mail. The questionnaire solicited information on demographic data, program awareness and attitudes towards degree-completion programs. The response rate was 63 percent. More than 65 percent of respondents were trained in Canada, were older than 30 years, and had at least one child. Ninety percent of respondents were aware of the Dalhousie program; seven were currently enrolled. Ninety-three percent of respondents were confident they could continue to practise without a degree and 70 percent were confident they could meet academic standards required to complete a degree. Respondents were least certain on whether employers valued experience over a degree. Family responsibilities, age over 50, and job security were deterrents to enrollment. Nondegree physiotherapists in Atlantic Canada may not choose to upgrade to a degree because of the regional manpower shortage and job security. A strong pool of degree-completion students was not identified.

Canada↗