PubMed Health⌕ Search

Biomedical subjects

R M Young

Publications and source records attributed to R M Young.

69 records · Page 4Linked to original sources
PubMed1982

Sound output of electronic laryngeal prostheses at room and body temperature.

An electronic laryngeal prosthesis, fully-implantable in the neck, is a desirable source of artificial voice. Emitted sound energy in a frequency range suitable for adult males and females must be of the correct period and intensity and rich in powerful harmonics. Any such device places severe demands on a bioencapsulant used to enclose the transducer. Location of the devices within the central neck demands a prosthesis-coating combination capable of passing sound energy at central body temperature. This study reports on four identical prostheses, coated with a polyvinylidene chloride, a copolyether polyurethane, a semi-rigid epoxy, or uncoated. Units were tested at room (72 degrees F) and body (100 degrees F) temperature in a sound-isolated chamber. Results indicated that performance of the uncoated unit was altered due to temperature effects. The presence of the polymer encapsulants did not have any differential effect on sound spectrum due to temperature differences.

Biocompatible Materials↗
PubMed1981

Effectiveness of out-of-hours biochemistry investigations.

A survey was carried out of doctors who used their out-of-hours biochemistry service to find out why requests for investigations were made, how often the results altered patient management, and whether they could define areas where investigations were unproductive. Of 107 questionnaires distributed, 147 (88%) were completed. In 86% the requests were for diagnosis or immediate patient management and in 35% the results actually altered management. Senior clinical staff were more efficient than their juniors in instigating biochemical investigations that proved to be effective. In no instance where the clinical staff predicted that it was unlikely that the results would alter management was management altered. It is suggested that joint reviews of case notes by junior and senior clinical staff would prove to be the most appropriate way to increase the effectiveness and efficiency of clinical investigation.

Biochemistry↗
PubMedDate not supplied

Pharmacokinetics of oral pramiracetam in normal volunteers.

The pharmacokinetics of pramiracetam, a new, investigational, cognition activator, were assessed in normal male volunteers as part of a clinical tolerance study. In a double-blind, randomized design, two groups of six subjects each received alternating placebo and single 400, 800, 1,200, and 1,600 mg oral doses of pramiracetam after an overnight fast. Mean (+/- SD) peak plasma concentrations of the four dose groups (2.71 +/- 0.54, 5.40 +/- 1.34, 6.13 +/- 0.71, 8.98 +/- 0.71 micrograms/mL) were attained between two to three hours following drug administration. The harmonic mean elimination half-life (4.5-6.5 hours), the mean total body clearance (4.45-4.85 mL/min/kg), the mean renal clearance (1.83-3.00 mL/min/kg), and the mean apparent volume of distribution (1.82-2.94 L/kg) were independent of dose, whereas the peak plasma concentrations and area under the curves increased as a linear function of dose. No significant side effects were observed at any dose level.

Administration, Oral↗
PubMedDate not supplied

The predictive utility of drinking refusal self-efficacy and alcohol expectancy: a diary-based study of tension reduction.

The potential tension reduction effects of alcohol may be most appropriately tested by examining the role of alcohol related beliefs regarding alcohol's anxiolytic properties. The relationship between affective change drinking refusal self-efficacy, tension reduction alcohol expectancies, and ongoing drinking behavior was examined amongst 57 regular drinkers. Alcohol consumption, antecedent, and consequent mood states were monitored prospectively by diary, Social learning theory hypothesizes that low drinking refusal self-efficacy when experiencing a negative mood state should be associated with more frequent drinking when tense. Strong alcohol expectancies of tension reduction were hypothesized to predict subsequent tension reduction. Contrary to this hypothesis, the present study found that alcohol expectancies were more strongly related to antecedent mood states. Only a weak relationship between drinking refusal self-efficacy and predrinking tension, and between alcohol expectancy and subsequent tension reduction, was evident.

Adult↗
PubMedDate not supplied

Mesenteric revascularization in a contaminated abdomen: a case report.

The management of acute mesenteric ischemia in the contaminated abdomen may require the use of an autogenous graft to achieve mesenteric revascularization. The authors present a case of an ischemic small bowel perforation in a 62-year-old-woman whose preoperative angiogram demonstrated occlusion of the celiac, superior mesenteric, and inferior mesenteric arteries. Vein mapping of the right greater saphenous vein demonstrated a dual saphenous system whose individual diameters were more than 4 millimeters. Exploratory laparotomy revealed a diffusely ischemic small bowel and liver, as well as abdominal sepsis from the perforated small bowel. Revascularization was accomplished by using saphenous vein in a nonreversed orientation as a bifurcated conduit from the supraceliac aorta to the hepatic and superior mesenteric arteries. Following revascularization, the liver and small bowel immediately regained a normal perfused appearance and the perforated segment of small bowel was resected and reanastomosed. She returned for a follow-up clinic visit 5 months later and was found to have an asymptomatic 6 cm aneurysm involving the proximal mesenteric vein bypass. The aneurysmal aspect of the vein bypass was replaced with a polytetrafluoroethylene interposition graft originating from the supraceliac aorta. On follow-up 3 months later, her aortomesenteric bypass is patent without aneurysmal recurrence, and she is clinically asymptomatic from any symptoms of mesenteric ischemia.

Abdomen↗