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Biomedical subjects

M McDonald

Publications and source records attributed to M McDonald.

At least 145 records · Page 8Linked to original sources
PubMed1986

Functional preservation of the mammalian kidney. VII. Autologous transplantation of dog kidneys after treatment with dimethylsulfoxide (2.8 and 4.2 M).

This research demonstrates that dog kidneys perfused with dimethylsulfoxide (Me2SO) in likely cryoprotective concentrations (2.8 M) can survive as the sole source of renal support when autologously transplanted. Kidneys were perfused in vitro with Me2SO in one of two vehicles: solution A (K+-Mg2+-rich) or RPS-2 (K+-glucose-rich). Me2SO concentration in the vehicle was gradually increased to maximum (2.8 or 4.2 M) over a period of 28 to 35 min, held for 5-10 min, then decreased over 55-65 min. All groups except one consisted of 5 kidneys perfused at 25 degrees C. Survivors were dogs living 21 days postoperatively. The first group received kidneys perfused with solution A; 5 dogs survived, serum creatinine on day 21 [Cr], [mean +/- SE] = 1.3 +/- 0.1. The second group received RPS-2 kidneys; 4 survived, Cr=1.4 +/- 0.1. The third group received solution A kidneys with 2.8 M Me2SO; 3 survived, Cr=2.7 +/- 1.3. The fourth group received RPS-2 kidneys with 2.8 M Me2SO; 5 survived, Cr=1.2 +/- 0.2. The fifth group received RPS-2 kidneys with 4.2 M Me2SO; 2 survived, Cr=1.7 +/- 0.3. One group of 6 dogs received kidneys perfused at 10 degrees C with 4.2 M Me2SO in RPS-2; one survived, Cr=1.4. Results demonstrate beneficial interaction of vehicle with Me2SO and the efficacy of 25 degrees C perfusion.

Animals↗
PubMed1985

Mitoxantrone as first-line chemotherapy in advanced breast cancer: results of a collaborative European study.

Mitoxantrone (Novantrone; dihydroxyanthracenedione) is a substituted anthraquinone with a spectrum of activity similar to doxorubicin in experimental tumors. One hundred and seventy three patients with advanced breast cancer and no prior cytotoxic therapy for advanced disease entered a phase II study of mitoxantrone, 14 mg/m2 i.v. repeated every 3 weeks. At the time of this analysis 116 patients were evaluable. Eight patients achieved a complete response and 27 a partial response, the overall response rate being 30% (95% confidence limits: 22-39%). The median time until response was recorded was 15 weeks. The median duration of response was 74+ weeks and the median time to progression or death for all 116 patients was 22+ weeks. Mitoxantrone was well tolerated with myelosuppression as the dose-limiting toxicity. The most frequent non-haematological toxicities were nausea and vomiting (65%) but they were rarely severe. Total alopecia occurred in only 6% of the patients. Four patients developed clinically significant evidence of cardiotoxicity after cumulative mitoxantrone doses of 174-256 mg/m2. Thus, mitoxantrone offers comparable efficacy and less acute toxicity than the most active single agents currently available in the treatment of advanced breast cancer.

Adult↗
PubMed1985

Beneficial effects from systematic dosage reduction of the diuretic, chlorthalidone: a randomized study within a clinical trial.

The purpose of this study was to determine the effects on blood pressure and selected biochemical measures of reducing the dosage of chlorthalidone from 100 mg to 50 mg. Within the larger study (Multiple Risk Factor Intervention Trial), 140 Special Intervention hypertensive men, taking 100 mg of chlorthalidone daily, were randomly assigned to either a continuation of 100 mg or a dosage reduction to 50 mg daily. Men were followed monthly for 4 months. Measures were made of blood pressure, serum potassium, serum uric acid, serum glucose, serum cholesterol, and triglycerides. Blood pressure change from baseline to 4 months revealed a significantly higher diastolic blood pressure in the group continued on the 100 mg dose compared to the dose reduction group. However, analysis of covariance, which took into account baseline differences in blood pressure, resulted in a nonsignificant difference in follow-up blood pressure (systolic and diastolic) between groups. Serum potassium increased significantly in the dose reduction group, especially in those participants taking supplemental potassium chloride. The results of this study demonstrate that a reduced dose of 50 mg chlorthalidone over the 4-month period was as effective as the 100 mg dose in long-term, well-controlled hypertensive men. Careful study of other antihypertensive agents is warranted to determine the drug dose that is maximally effective for blood pressure lowering and that also minimized toxic and adverse effects.

Blood Glucose↗
PubMed1985

Compliance with hypertension treatment. Strategies for improving patient cooperation.

Adherence to medical advice and regimens is a basic consideration in the ongoing management of hypertensive patients. The magnitude of poor compliance and noncompliance is a substantial problem in many settings. However, even the busiest practitioner can detect patients with adherence problems through such simple, practical methods as watching for missed clinic visits and directly questioning patients. Although numerous factors have been related to suboptimum compliance, it is clear that no single factor is predictive. The best approach for improving compliance appears to involve a combination of strategies.

Attitude to Health↗
PubMed1984

Psychosocial characteristics of candidates for the prospective evaluation of radial keratotomy (PERK) study.

The National Eye Institute Prospective Evaluation of Radial Keratotomy (PERK) Study is a multicenter clinical trial for the evaluation of radial keratotomy. This article describes the questionnaire data collected on PERK patients and compares them with a similar group of myopic persons studied during the Rand Health Insurance Experiment (heretofore referred to as the Rand study). The PERK patients are young, white myopes who dislike being dependent on corrective lenses but perceive themselves to be more visually impaired than do comparable Rand study myopes. Most female subjects and a plurality of the male subjects have tried contact lenses and quit wearing them mainly because use of the lenses was inconvenient or bothersome. There is no evidence that patients are psychologically or socially deviant. Both male and female subjects expressed a fear of being without vision and cited impatience with the lenses as their major motivation for wanting surgery.

Adolescent↗
PubMed1984

Mitoxantrone for the treatment of advanced breast cancer: single-agent therapy in previously untreated patients.

Mitoxantrone (dihydroxyanthracenedione) is a substituted anthraquinone with a similar spectrum of activity to adriamycin in experimental tumours. One hundred and thirty-four patients with advanced breast cancer and no prior chemotherapy for advanced disease were treated with mitoxantrone (14 mg/m2 i.v. q 3 weeks), of whom 99 are presently evaluable for response and all for toxicity. Six patients achieved a complete response and 29 a partial response, the overall response rate being 35% (95% confidence limits, 25-45%). Median time to treatment failure was greater than 46 weeks. Mitoxantrone was well tolerated, myelosuppression being the dose-limiting toxicity. The most frequent nonhaematological toxicities were nausea and vomiting (40%), but these were rarely severe. Total alopecia occurred in only 6 patients. Four patients developed clinically significant evidence of cardiotoxicity after cumulative mitoxantrone doses of 174-256 mg/m2. Mitoxantrone offers comparable efficacy and less acute toxicity than the most active currently available single agents in advanced breast cancer.

Adult↗
PubMed1984

Mitoxantrone as first-line chemotherapy for advanced breast cancer: results of a European collaborative study.

A total of 134 patients with advanced breast cancer and no prior chemotherapy for advanced disease were treated with mitoxantrone, 14 mg/m2 intravenously every 3 weeks. Of these, 99 could be evaluated for response and all for toxicity. Six patients achieved a complete response and 29 a partial response, the overall response rate being 35% (95% confidence limits 25% to 45%). The median time to treatment failure was greater than 46 weeks. Mitoxantrone was well tolerated. Nausea and vomiting occurred in 40% of patients, but these were seldom severe. Total alopecia occurred in only six patients. Four patients developed clinically significant evidence of cardiotoxicity after cumulative doses of 174 to 256 mg/m2. Mitoxantrone offers comparable efficacy and less acute toxicity than the most active single agents currently used in the treatment of advanced breast cancer.

Adult↗
PubMed1982

Antibiotic-associated diarrhoea and methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus was thought to be the cause of 10 cases of antibiotic-associated diarrhoea observed over a 12-month period at The Royal Melbourne Hospital. Each patient had significant underlying disease, and all had been treated with multiple, broad-spectrum antibiotic agents. The diagnosis was made on the distinctive Gram-stain appearance of faecal smears, the heavy predominant growth of methicillin-resistant Staph. aureus from stool cultures, and the absence of other bowel pathogens, including toxigenic Clostridium difficile. Diarrhoea usually responded to treatment with vancomycin or bacitracin, and, in patients whose condition improved, the stools cleared of staphylococci. Patients with staphylococcal diarrhoea present a significant crossinfection risk, and early diagnosis, treatment, and isolation are essential.

Adult↗
PubMed1982

Trilostane and the normal hypothalamic-pituitary-adrenocortical axis.

Trilostane has been used to treat Cushing's syndrome and other adrenocortical disorders. To investigate its effect on the normal adrenal gland, trilostane (initially 240 mg/day) was given to ten healthy men, the dose increasing at weekly intervals by 240 mg/day up to a final dose of 960 mg/day. The drug was well tolerated although one subject withdrew after the first week because of gastrointestinal side effects. Trilostane had no significant effect on aldosterone levels or blood pressure. The mean 24-h urinary free cortisol excretion rose from 14.2 to 22.0 mumol/mol creatinine (P less than 0.01) before and after trilostane 240 mg/day but did not rise thereafter. Early morning serum cortisol and plasma ACTH levels did not change on trilostane. The mean increment in serum cortisol after the i.v. injection of 0.25 mg of ACTH was reduced from 398 nmol/l before trilostane to 287 nmol/l on 240 mg/day and to 291 nmol/l on 960 mg/day (P less than 0.01). Insulin-induced hypoglycaemia while on 960 mg/day produced a maximum increment in serum cortisol of 361 +/- 118 nmol/l (mean +/- SD) although one subject had a subnormal increment of 180 nmol/l (normal greater than 200 nmol/l). Plasma ACTH rose with hypoglycaemia in all cases. We conclude that trilostane has only a minor effect on the normal hypothalamic-pituitary-adrenocortical axis.

Adrenocorticotropic Hormone↗