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Biomedical subjects

W A Reynolds

Publications and source records attributed to W A Reynolds.

At least 19 recordsLinked to original sources

Barriers to prostate cancer screening.

The revised prostate cancer screening guidelines of the American Cancer Society recommend that men be informed of the risks associated with prostate cancer screening. However, there are no published studies on men's fear of impotence and its impact on prostate cancer screening. In addition, little is known about barriers to prostate cancer screening when the two main barriers of cost and lack of knowledge are eliminated. This study reports the association between barriers and free prostate cancer screening after a prostate cancer education program. All men were called 1 month after a prostate cancer education program and asked: "What would (or did) make it hard for you to get your prostate checkup done?" A total postbarrier score was created to measure how many barriers each man indicated. The following barriers were significant in predicting participation in prostate cancer screening: "put it off," "doctor hours not convenient," "didn't know kind of doctor," "didn't know where to go," and "refuse to go." Fear of impotence was not a significant barrier. Suggestions for reducing barriers to prostate cancer screening are given.

Adult↗

Urinary symptoms as a predictor for participation in prostate cancer screening among African American men.

BACKGROUND: There are minimal data on the influence of urinary symptoms and participation in prostate cancer screening in African American men. METHODS: This correlational study examined the influence of urinary symptoms on 1) participation in a free prostate cancer screening program and 2) abnormal screening results. The 1,402 African American men in the South Carolina Prostate Cancer Project (SCPCP), mean age of 50 years, completed a survey that included self-reported urinary symptoms, participated in a prostate cancer educational program, and received a free prostate cancer screening consisting of a digital rectal examination (DRE) and prostate-specific antigen (PSA) from their personal physician. RESULTS: One in 5 men reported the presence of urinary symptoms. Over 60% of the 1,402 men participated in the free CaP screening. Among the 852 men who participated in the free prostate cancer screening, 73 (8.6%) had abnormal screening results as classified by abnormal DRE and/or PSA >4.0 ng/ml. Urinary symptoms were significant predictors, both of participation in screening (OR = 1.30, CI = 1.00, 1.70) and of obtaining an abnormal screening result (OR = 1.78, CI = 1.17, 2.72). CONCLUSIONS: Prostate cancer health education needs to include the fact that prostate cancer, in its early stages, has no urinary symptoms.

Adult↗

Increasing prostate cancer screening in African American men with peer-educator and client-navigator interventions.

BACKGROUND: Few African American men participate in prostate cancer screening, although they have higher prostate cancer incidence and mortality rates. METHODS: This study documents the benefits of two educational methods; the peer-educator method and the client-navigator method, in increasing their participation. RESULTS: Sixty-one percent of the 1,211 African American men who received an educational program on prostate cancer participated in the free prostate cancer screening. Men who received the peer-educator method intervention, which included a testimony in support of prostate cancer screening given by an African American man, were more likely to participate, p = 0.04, than were men who received a standard educational program. Also, men who received the client-navigator method intervention, which included 1) a phone call aimed at overcoming screening barriers and 2) reminders for screening, were more likely to participate, p = 0.0001. CONCLUSIONS: More African American men will participate in prostate cancer screening following the peer-education and client-navigator interventions.

Black or African American↗

Comparison of acute subjective and heart rate effects of nicotine intake via tobacco smoking versus nasal spray.

Nicotine is the primary psychoactive constituent of tobacco smoke, but it is not clear whether the reinforcing effects of cigarette smoking can be attributed solely to nicotine intake. In this study, two groups of male and female smokers participated in three sessions involving intermittent exposure to moderate low, or no nicotine doses via controlled tobacco smoking ("smoke," n = 20) or measured-dose nasal spray ("spray," n = 16). Visual analog scales of subjective effects (VAS) and heart rate (HR) were obtained within 5 min of each dosing. Plasma nicotine levels indicated comparable dosing between methods. For both methods, there were significant nicotine dose effects for most subjective measures and HR. More importantly, the pattern of effects across doses was virtually identical between methods, as nicotine intake via smoking or spray significantly increased HR and the VAS scales of Head Rush and Dizzy, decreased Hunger and Desire to Smoke, and had no effect on Comfortable, Jittery, or Relaxed. These results suggest that rapid nicotine uptake by novel methods may provide effects very similar to nicotine intake by smoking.

Administration, Intranasal↗

Chronic and acute tolerance to subjective, behavioral and cardiovascular effects of nicotine in humans.

Understanding tolerance to effects of nicotine in humans may elucidate processes involved in the onset and maintenance of tobacco dependence. Subjective, behavioral and cardiovascular responses to nicotine were examined as a function of past history of nicotine exposure (i.e., smokers vs. nonsmokers, chronic tolerance) and of immediately preceding nicotine exposure (acute tolerance). Dose-effect relationships between nicotine (0-2 micrograms/kg via measured-dose nasal spray) and each response were determined in male and female smokers (n = 17) and nonsmokers (n = 18), with different doses presented on different days. Each day, subjects also received a challenge dose of 20 micrograms/kg 30 min after the previous dosing to assess acute tolerance. Plasma nicotine concentrations were 30% lower in nonsmokers compared with smokers and analyses were adjusted to control for this difference. Results showed significant changes in nearly all responses as a function of nicotine dose. Dose-effect curves were shifted to the right or dampened in smokers relative to nonsmokers for most subjective and some behavioral responses, consistent with chronic tolerance, but there was less evidence of chronic tolerance to other behavioral effects or to cardiovascular responses. A pattern of acute tolerance generally similar to that of chronic tolerance was observed across response domains (i.e., clear acute tolerance to subjective measures but less to behavioral or cardiovascular effects). These results support the notions that regular use of nicotine is associated with chronic functional tolerance and that repeated nicotine exposure during a single episode produces acute tolerance. A similar pattern of chronic vs. acute tolerance suggests similarity of mechanisms responsible for both "types" of tolerance. However, variability in tolerance magnitude across subjective, behavioral and cardiovascular response domains indicates that different mechanisms may be responsible for these different effects of nicotine.

Adult↗

Fibrocartilaginous dysplasia of bone.

Fibrocartilaginous dysplasia is a benign, unusual complication of fibrous dysplasia occurring in the lower extremities, especially the femoral neck. Rapid growth and chondroid features may cause fibrocartilaginous dysplasia to be misdiagnosed as malignant. True chondrosarcomatous transformation of fibrous dysplasia is probably very rare. A recent case of fibrocartilaginous dysplasia is presented.

Adolescent↗

Inhibition of the enzymes of glutathione metabolism by mercuric chloride in the rat kidney: reversal by selenium.

The treatment of rats with 10 mumoles/kg (s.c.) of mercuric chloride (Hg2+) caused time-dependent decreases in the activities of the enzymes of the glutathione (GSH) metabolism pathway in the kidney. Twenty-four hours after administration of Hg2+, the activities of gamma-glutamylcysteine synthetase and glutathione disulfide (GSSG)-reductase in the kidney were decreased by 50-60%, and the activities of the GSH catabolic enzymes, gamma-glutamyl transpeptidase and GSH-peroxidase, were decreased by 25-35%. In the liver, only the activity of GSSG-reductase was decreased at this time. The observed decreases in the enzyme activities were not accompanied by a depression in the cellular protein concentration. The same pattern of enzyme response was noted when rats were given 30 mumoles/kg Hg2+; however, the decreases in the specific activity of the enzymes were accompanied by great losses in the cellular protein concentrations in both the liver and the kidney (35-40%). This dose of Hg2+ also caused significant decreases in the concentration of GSH in both organs. In vitro, Hg2+ only inhibited the activity of GSSG-reductase. When rats were given sodium selenite (Na2SeO3; 5, 10 or 20 mumoles/kg, s.c.) 30 min after Hg2+ treatment (10 mumoles/kg), the Hg2+-related depressions in the activities of the enzymes of GSH metabolism in the liver and the kidney were blocked. Also, in rats treated with 30 mumoles/kg Hg2+, the administration of 10 mumoles/kg selenium significantly decreased the magnitude of depression in the concentration of GSH in the kidney.

Animals↗

Calcitropic hormone responsiveness during pregnancy.

Release of the calcitropic hormones parathyroid hormone (PTH) and calcitonin (CT) in-response to provocative stimuli was assessed in pregnant rhesus monkeys tested three times during gestation (corresponding to the end of each trimester) and again 6 weeks post partum. In the case of PTH, although basal levels were higher during pregnancy than post partum and tended to increase with advancing gestation, similar to observations in human subjects, the incremental response of the hormone to a hypocalcemic stimulus was diminished in pregnant animals and tended to lessen with advancing gestation. Basal CT levels were also increased during pregnancy but, in contrast to PTH, the incremental CT response to a provocative stimulus was generally greater during pregnancy than post partum and tended to increase with advancing gestation. The explanation of these findings may lie in differing degrees of hormone storage. These adjustments in maternal endocrine physiology regulating calcium metabolism would have the net effect of tending to preserve the maternal skeleton by protecting it from excessive resorption at times of hypocalcemia and promoting increased calcium storage during episodes of hypercalcemia.

Animals↗