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Biomedical subjects

M R Clarke

Publications and source records attributed to M R Clarke.

49 records · Page 3Linked to original sources
PubMed1986

Social dominance and serum testosterone concentration in dyads of male Macaca fascicularis.

The relationship between social dominance and serum testosterone concentration was evaluated in 24 male Macaca fascicularis in 14 dyads at 2-week intervals over an 8-month period. No associations between testosterone concentration and dominance ranks were found in dyads with "clear dominance" relationships. A significant positive association was found between testosterone concentration and dominance ranks in dyads that exhibited "contested dominance" or dominance reversals. Thus, higher testosterone concentration corresponded to social dominance in subjects dominant as the result of a contest, rather than a consequence of high relative rank.

Animals↗
PubMed1977

Variations of sodium, potassium, and chloride plasma levels in the rat with age and sex.

Sodium, potassium, and chloride plasma levels were measured in 294 male and 286 female Sprague Dawley rats [Crl:COBS CD(SD)BR]. The rats were distributed between four groups according to age (65-125 days, 235-275 days, 353-482 days, and 665-775 days). The levels of all three ions were higher in males than in females: about 1% higher for sodium and chloride and about 7% higher for potassium. Potassium and chloride values decreased with increasing age in both sexes; potassium decreased 12% and chloride decreased 6%. Distributions were not perfectly Gaussian but the departures from normality were slight. It was concluded, therefore, that determinations based on parametric statistical tests on the data are unlikely to be seriously biased by the distribution.

Age Factors↗
PubMedDate not supplied

Parathyromatosis: a cause for recurrent hyperparathyroidism.

OBJECTIVE: To report a case of parathyromatosis as a cause for recurrent hyperparathyroidism. METHODS: We present the case history, laboratory results, operative interventions, and pathologic findings in a 36-year-old woman. Relevant reports from the literature are reviewed. RESULTS: Our patient, who had been undergoing long-term hemodialysis because of renal failure, presented with secondary hyperparathyroidism and progressive bone pain. After an uneventful subtotal parathyroidectomy (removal of 3-1/2 glands), her symptoms resolved in conjunction with normalization of parathyroid hormone levels. Subsequently, however, recurrent hyperparathyroidism and severe bone pain necessitated second and third neck explorations, during which parathyromatosis was discovered. A total thyroidectomy was performed because of the bilateral nature of the disease. Postoperatively, the patient's bone pain resolved substantially, although her parathyroid hormone levels remained high. CONCLUSION: Parathyromatosis is a rare cause of recurrent hyperparathyroidism after parathyroidectomy. It consists of hyperfunctioning parathyroid tissues scattered throughout the neck, due either to intraoperative tissue spillage and subsequent implantation or to hyperplasia of parathyroid rests from embryologic development. This is one of the few case reports of parathyromatosis and the first case report of a mixed form of the disease, consisting of features of both subcapsular parathyroid rests and extracapsular implantation.

Adult↗
PubMedDate not supplied

Preoperative chemoradiotherapy for carcinoma of the esophagus and gastroesophageal junction.

PURPOSE: To determine whether combination 5-fluorouracil, cisplatin, and interferon alfa, an active regimen in advanced esophageal cancer, is efficacious as induction therapy before esophagectomy. MATERIALS AND METHODS: Forty-four patients with potentially resectable esophageal/gastroesophageal junction adenocarcinoma or squamous cell carcinoma were entered into a phase I/II study of this chemotherapeutic regimen and concurrent external-beam radiotherapy before resection. The initial 16 patients were treated with prolonged-infusion 5-fluorouracil (300 mg/m2 on days 1 to 28), cisplatin (20 mg/m2 on days 1 to 5 and 24 to 28), interferon alfa (3 x 10(6) U/m2 intravenously on days 1 to 5 and 24 to 28; subcutaneous injection every other day on days 6 to 23), and radiation (4000 cGy). The subsequent 28 patients were treated over 21 days with two modifications: dose escalation of 5-fluorouracil (250 to 350 mg/m2) and double-fractionated radiotherapy to a total dose of 4500 cGy. RESULTS: Forty-one patients completed chemoradiotherapy and were evaluable for toxicity. Adverse events were substantial but tolerable, and most toxic episodes were hematologic and gastrointestinal. Three patients died, and one patient had progressive disease before resection. Of the 37 patients eligible for curative resection, 36 had all gross tumor removed. Thirty-three (80%) patients had a major pathologic response: 10 (24%) with no residual tumor and 23 with only microscopic residual tumor. Median survival for all patients was 27 months and for responders was 36 months. CONCLUSIONS: This combination regimen is active but yields results similar to those of other chemoradiotherapy phase II trials; therefore, the contribution of interferon alfa to treatment efficacy remains uncertain. The true worth of preoperative chemoradiotherapy is unknown pending results of phase III trials.

Adenocarcinoma↗