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Biomedical subjects

R B Lee

Publications and source records attributed to R B Lee.

At least 73 records · Page 4Linked to original sources
PubMed1982

A comparative pilot study of enalapril, a new converting enzyme inhibitor, and hydrochlorothiazide in essential hypertension.

Eight patients with essential hypertension completed a double-blind, randomly allocated crossover comparison of either 5 or 10 mg enalapril maleate, 50 mg hydrochlorothiazide, or their combination administered once daily during sequential two-week periods. Blood pressure, pulse rate, plasma renin activity, angiotensin-converting enzyme activity, plasma aldosterone concentration, and urinary electrolytes were monitored for 24 hours after placebo and on days 1 and 14 of each treatment period. After two weeks of each treatment, only the combination of enalapril and hydrochlorothiazide significantly lowered the mean seated diastolic blood pressure (SDBP). Likewise, SDBP control (less than or equal to 90 mm Hg) was achieved only after combination therapy; six of the eight patients were controlled by the combination for up to 24 hours. The initial SDBP response to combination therapy differed with the sequence of drug addition; however, by day 14 the responses were comparable, regardless of whether hydrochlorothiazide or enalapril was first given. Mean converting enzyme activity was suppressed by enalapril in all patients, though it did not always correlate with changes in SDBP or plasma aldosterone. Mean plasma renin activity increased, but the increase was significant only on the combination. There were no serious adverse effects.

Adult↗
PubMed1982

Kinetics of osmotically controlled indomethacin delivery systems after repeated dosing.

Two osmotically driven, controlled-release dosage forms of indomethacin were evaluated in a multiple-dose crossover study in 12 healthy subjects. Following equivalent daily doses, less frequent dosing of both controlled-release forms resulted in plasma concentration profiles that are more uniform than those following capsule regimens. After the first day, morning predose plasma levels wer significantly higher for the controlled-release treatments. Renal clearances were similar between days and among treatments. Total urinary recoveries were comparable for all regimens.

Delayed-Action Preparations↗
PubMed1981

Pharmacology of enantiomers and (-) p-OH metabolite of indacrinone.

Indacrinone, a racemic mixture, is a loop-blocking diuretic with effects on uric acid elimination that differ from those of furosemide. A series of studies in healthy men was undertaken to characterize the pharmacologic activity of the positive (+) and negative (-) enantiomers (E) of indacrinone and its (-) p-OH metabolite, (-) MET. All subjects were on sodium- and potassium-controlled diet; each experiment was similar in design and included placebo and positive controls. Oral (-)E and (-)MET exerted dose-related natriuretic and diuretic effects; intravenous doses of (-)E were more effective than (-)MET. The effects of (-)E and (-)MET on serum uric acid were the same as those reported with indacrinone. After (-)E, both (-)E and generated (-)MET appeared to contribute to the natriuresis. (+)E induced dose-related decreases in serum uric acid up to 24 hr after dosage; at the higher doses of (+)E, the hypouricemic effects were of the order of those after 500 mg of probenecid. Thus, indacrinone is a novel loop diuretic with enantiomers and a (-)MET, each of which has a different pharmacologic profile.

Adult↗
PubMed1981

Effects of diflunisal on platelet function and fecal blood loss.

The effects of diflunisal, a nonacetylated difluorinated salicylate, on platelet function were compared with those of aspirin and placebo. In a randomized, double-blind trial, normal subjects were given diflunisal, 250, 500, or 1,000 mg twice daily; aspirin, 650 or 1,300 mg twice daily; or placebo for 8-day periods. Difunisal, 250 mg, had no effect on platelet function, whereas 500 mg induced minimal inhibition of colagen-induced release of platelet serotonin, and 1,000 mg inhibited platelet malondialdehyde production, moderately prolonged template bleeding times (P = NS), and increased fecal blood loss (P less than 0.05). In contrast, aspirin, 650 mg, markedly inhibited collagen-induced platelet aggregation and serotonin release, and 1,300 mg prolonged bleeding time (P less than 0.01) and increased fecal blood loss (P less than 0.01). The effects of aspirin lasted for up to 5 days, whereas changes induced by diflunisal had returned to baseline 24 hr after the drug was discontinued. We conclude that in doses in the same range as those of aspirin diflunisal inhibits platelet function less.

Adult↗
PubMed1981

Cervical carcinoma in pregnancy.

Forty-one cases of invasive carcinoma of the cervix associated with pregnancy that were treated at the Walter Reed Army Medical Center from January 1961 through April 1979 were reviewed. Postpartum patients were included in the study if the diagnosis of cancer was made within 6 months of delivery. Three cases of clinical stage IA disease treated by Wertheim-Taussig hysterectomy had a 5-year survival rate of 100%. There were 22 cases of stage IB disease with a 5-year actuarial survival rate of 90%. Four patients with stage IB were treated by radiotherapy, 17 by Wertheim-Taussig hysterectomy, and 1 by a combination of pelvic irradiation, cesium application, and simple extrafascial total abdominal hysterectomy and bilateral salpingo-oophorectomy for a barrel-shaped cervix. Twelve cases of stage II disease treated by radiotherapy had a 5-year actuarial survival rate of 24%. There were no survivors in 2 cases of stages III and IV disease. The 5-year actuarial survival rate of patients with stage I carcinoma of the cervix associated with pregnancy is not statistically different from that of nonpregnant patients, regardless of the method of treatment.

Adult↗
PubMed1980

Minilaparotomy under local anesthesia for outpatient sterilization: a preliminary report.

An outpatient sterilization program was started at Silas B. Hays Hospital, Fort Ord, California, and later extended to Malcolm Grow USAF Medical Center and the Walter Reed Army Medical Center. From January 1976 to June 1978, two hundred and eight outpatient minilaparotomy Pomeroy tubal ligations were performed under local anesthesia. The minilaparotomy technique, using standard operating room equipment, is described. The average operating time was 31.8 minutes and the complication rate was 2.5%.

Adult↗
PubMedDate not supplied

Evidence for route dependent biotransformation of cyclobenzaprine hydrochloride.

Cyclobenzaprine hydrochloride was administered to healthy volunteers as a 10 mg oral tablet, 10 mg and 20 mg intramuscular injections, and a 10 mg intravenous injection. Urinary excretion and plasma level data for cyclobenzaprine together provide evidence for route dependent biotransformation. Urinary excretion of total cyclobenzaprine (unchanged plus the glucuronide conjugate) was greater for the oral treatment than for the parenteral treatments (i.m. and i.v.). Area under the plasma concentration-time curve for unchanged cyclobenzaprine, however, was less for the oral treatment than for the parenteral treatments. Based on area calculations, the bioavailability of the 10 mg oral tablet, 10 mg i.m. and 20 mg i.m. injection was 0.33, 0.76, and 0.56, respectively, when compared to the 10 mg i.v. injection of cyclobenzaprine hydrochloride. The four treatments were well tolerated and no clinically adverse effects were observed.

Adult↗
PubMedDate not supplied

Comparative antihypertensive effects of enalapril maleate and hydrochlorothiazide, alone and in combination.

Enalapril maleate is an investigational oral prodrug whose hydrolyzed diacid metabolite is a potent angiotensin-converting enzyme inhibitor. Fourteen patients with mild to moderate hypertension were evaluated after receiving placebo, and two weeks of treatment with each of the following: enalapril maleate (20 mg b.i.d.), hydrochlorothiazide (25 mg b.i.d.), and the two in combination. In comparison to placebo, the magnitudes of the blood pressure reduction after enalapril and hydrochlorothiazide alone were comparable. The reduction in blood pressure following enalapril was evident throughout the 12-hour dosing interval. The combination of enalapril and hydrochlorothiazide resulted in a marked further reduction in blood pressure that was greater than that predicted from the responses to the individual drugs (P less than 0.05). Biochemical parameters confirmed inhibition of angiotensin-converting enzyme during enalapril treatment; serum angiotensin-converting enzyme activity proved an excellent monitor of compliance. Enalapril was generally well tolerated. Adverse effects included symptomatic hypotension in three patients when enalapril was first added to hydrochlorothiazide and hyperesthesia of the oral mucosa without a loss of taste in one patient on enalapril. Enalapril maleate alone and especially in combination with hydrochlorothiazide appears to be an effective, well-tolerated converting enzyme inhibitor with at least a 12-hour duration of action.

Adult↗
PubMedDate not supplied

Fracture resistance of all-ceramic and metal-ceramic inlays.

PURPOSE: Metal-ceramic inlay designs were developed to determine if the esthetic qualities of all-ceramic inlays could be duplicated and at the same time improve their strength and stability. The objectives of this study were to: (1) compare the fracture resistance of metal-ceramic inlays with that of all-ceramic inlays; (2) determine the correlation between the degree of preparation taper and fracture resistance; and (3) determine the correlation between marginal gap width and fracture resistance. MATERIALS AND METHODS: Inlay preparations were made on 60 Dentoform teeth, with 30 teeth allocated for metal-ceramic inlays and 30 teeth for all-ceramic inlays. Each group was further subdivided into 5-, 10-, and 20-degree taper preparations. Metal-ceramic inlays were fabricated using Goldtech Bio 2000 metal and Ceramco porcelain extending to the margin, while all-ceramic inlays were made from Empress II ceramic. Marginal gap widths were measured at six critical areas after fabrication. The load at failure was measured using an Instron Universal Testing Machine. RESULTS: The mean fracture load for all-ceramic inlays and metal-ceramic inlays at 5, 10, and 20 degrees was 70+/-40 N, 48+/-37 N, 33+/-7 N, and 40+/-23 N, 29+/-22 N, and 14+/-4 N, respectively. The mean gap width was 105 microm and 126 microm for all-ceramic and metal-ceramic inlays, respectively. CONCLUSION: The mean fracture load for Empress inlays was significantly higher than that for metal-ceramic inlays. Inlays with a 5-degree taper were significantly more fracture resistant than those with a 20-degree taper. There was no relation between marginal gap width and fracture resistance.

Aluminum Silicates↗