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Biomedical subjects

C Reynolds

Publications and source records attributed to C Reynolds.

At least 127 records · Page 7Linked to original sources
PubMed1983

Hyperparathyroidism in pregnancy: case report and review of the literature.

The apparent incidence of hyperparathyroidism (HPT) is low in pregnancy but will likely increase now that more asymptomatic HPT is being diagnosed. However, since the serum calcium levels are decreased in pregnant women, mild primary HPT may go unrecognized. In untreated cases of HPT, complications during pregnancy or during the neonatal period have included spontaneous abortion, stillbirth, neonatal death, neonatal tetany and hypercalcemia. A review of the literature indicates a substantial improvement in fetal outcome when parathyroidectomy is done during pregnancy, as in the case reported here. Therefore, parathyroidectomy is the treatment of choice when the diagnosis is made during pregnancy, although oral phosphate therapy may be an alternative if surgery is contraindicated.

Adenoma↗
PubMed1983

Hyperinsulinism after removal of a pheochromocytoma.

The finding of hypoglycemia after the surgical removal of a pheochromocytoma in two patients in a previous study led to monitoring of the serum glucose and plasma C-peptide levels in two other patients with a pheochromocytoma and one with unilateral adrenocortical hyperplasia. In the two patients with a pheochromocytoma endogenous insulin secretion, as measured by a C-peptide assay, was suppressed before removal of the tumours and resumed immediately after removal. The serum glucose levels decreased in these patients, but sufficient intravenous administration of glucose prevented postoperative hypoglycemia. In the patient with adrenocortical hyperplasia the plasma C-peptide level was not decreased before tumour removal, nor did it increase abruptly following removal. It therefore seems likely that the rapid fall in the serum glucose level following removal of a pheochromocytoma is caused by prompt resumption of beta-cell activity, with rebound hyperinsulinism.

Adrenal Cortex Diseases↗
PubMed1983

Generalization of lowered EMG levels during musical performance following biofeedback training.

Electromyographic (EMG) biofeedback training offers a means by which musicians can control excess muscle tension during performance. Music instructors generally agree that unnecessary muscle tension not only leads to physical problems but also can interfere with performance quality. It is important, however, that the reduced EMG levels resulting from biofeedback training generalize to situations in which feedback is not available, and that the reduction in muscle tension not result in decreased performance quality. Eight intermediate to advanced clarinet players participated in four EMG biofeedback training sessions during which short-term and extended generalization of lowered EMG levels was assessed along with trill and scale speed scores. Significant reductions in EMG levels associated with biofeedback training generalized to short-term and extended situations, while trill and scale performances remained at or above pretest levels.

Adolescent↗
PubMed1983

Insulin.

Explore the source record for details and available documents.

Amino Acid Sequence↗
PubMed1982

Gastric and pancreatic hyposecretion following massive small-bowel resection.

It is well established that massive small-bowel resection (MSBR) invariably causes hypersecretion of acid in animals with denervated gastric pouches. The effect of MSBR on the secretory responses of both the totally innervated stomach and pancreas have been less well studied. Eighteen adult mongrel dogs were prepared with chronic gastric and pancreatic fistulae. In eight, massive small-bowel resection was performed in addition. Bowel resection did not alter the responses to graded doses of pentagastrin. However, in response to the intragastric titration of a liver extract meal, it had the following effects: (1) profound gastric acid hyposecretion; (2) reduction in pancreatic bicarbonate and protein secretion; and (3) increase in basal and meal-stimulated serum glucagon levels. Hypergastrinemia did not occur after resection. The hyposecretory responses may represent either increased inhibition or decreased secretory stimulation.

Animals↗
PubMed1982

Intravenous nitroglycerin control of blood pressure during resection of phaeochromocytoma.

The majority of patients presenting for resection of phaeochromocytoma require some form of antihypertensive therapy during operation. Phentolamine and sodium nitroprusside have both been used successfully for this purpose, but each has disadvantages. This report describes the use of intravenous nitroglycerin, a rapidly acting venodilator with no appreciable toxicity, as the sole antihypertensive agent in two patients with phaeochromocytoma and partial alpha adrenergic blockade. Hypertensive episodes were quickly and effectively controlled in each case. There were no hypotensive periods and no side effects.

Adrenal Gland Neoplasms↗
PubMed1981

Using biofeedback to reduce left arm extensor EMG of string players during musical performance.

Electromyographic (EMG) feedback offers a mechanism for helping musicians reduce specific muscle tension during performance. Nine intermediate to advanced level string players participated in a four-session, pretest/posttest design study to determine (1) if left forearm extensor EMG could be reduced using biofeedback, (2) if reductions in EMG would generalize to a no-feedback condition, and (3) if reductions in EMG would generalize from extensors to flexors. Results indicate that biofeedback did facilitate significant decreases in EMG, that the reductions in EMG did generalize to a no-feedback condition, and that generalization from extensors to flexors did not occur.

Adolescent↗
PubMed1981

Evidence concerning insulin activity from the structure of a cross-linked derivative.

The important of crystallographic refinement for confident structural description, even at modest resolution, is demonstrated for N alpha A1,N epsilon B29-L,L-2,7-diaminosuberoyl (A2sb) insulin, a cross-linked insulin of low potency. The spatial arrangement of the cross-link itself can be described, and reliable estimates of the accuracy in atomic positions obtained. Comparison of invariant A2sb and native insulins shows a strong structural similarity, especially for the A chain surface residues and the dimer-forming residues of the B chain which have generally been strongly implicated in the receptor-binding region. Evidence from this analysis directs attention to the A chain, particularly the backbone, as being important in interactions with the membrane-bound receptor.

Animals↗
PubMed1979

Gastric inhibitory polypeptide response to hyper- and hypoglycemia in insulin-dependent diabetics.

The response of gastric inhibitory polypeptide (GIP) levels to oral glucose in 11 insulin-dependent diabetics was compared to that in 8 age- and sex-matched healthy controls to determine whether they would show the pattern of GIP hypersecretion reported by other workers in maturity-onset, insulin-independent diabetes. One gram of glucose per kg bw resulted in a higher level of glycemia and a significantly diminished GIP response in diabetics when compared to controls (6,018 +/- 1,337 vs. 11,343 +/- 2,353 pg/ml.180 min min, respectively). There was virtually no beta cell response in the diabetics, as measured by changes in the levels of free insulin and connecting peptide. A significant lowering of glucagon levels occurred in the controls, while an inconsistent response was seen in the diabetics. An insulin infusion test was administered to test the hypothesis that insulin suppresses GIP secretion. Although hyperinsulinism, hypoglycemia, and suppression of endogenous insulin secretion were produced in the controls, no suppression of baseline GIP was detected. Similarly, hyperinsulinism and hypoglycemia failed to suppress baseline GIP levels in the diabetics. These results do not support a direct role for insulin in suppressing GIP in normal or diabetic subjects.

Adult↗
PubMed1979

Metabolic effects of glucose, mannose, galactose, and fructose in man.

The effects of various hexoses upon immunoreactive insulin (IRI) secretion, glucose disposal, and gastric inhibitory polypeptide (GIP) release have been compared in 10 normal nonobese men. Rapid iv infusion (0.5 g/kg in 3 min) of D-mannose resulted in significant ITI release, the peak levels approaching those after D-glucose infusion. D-Galactose, however, was ineffective. The 60-min urine excretions of mannose, galactose, and glucose were 35 +/- 7%, 16 +/- 4%, and 5.5 +/- 0.7% (mean +/- SEM) of the administered dose, respectively. All subjects also received 50 g oral glucose, mannose, galactose, and fructose on different days, each followed by an iv glucose infusion 30 min later. The ingestion of glucose or galactose resulted in a similar increment of GIP (P less than 0.01), followed by a similar increment in the IRI response to iv glucose. Furthermore, the glucose disposal rate increased 2.5-fold compared to that after iv glucose alone (P less than 0.001). However, oral msnnose or oral fructose caused no significant GIP release, yet the IRI response to a subsequent iv glucose load was moderately augmented after oral mannose or oral fructose when compared to iv glucose alone. In addition, there was a similar enhancement of glucose disposal of the iv glucose load after both oral mannose and oral fructose (P less than 0.01). From these studies we conclude that 1) galactose does not elicit IRI secretion per se, yet, like glucose, potentiates GIP and IRI secretion; 2) mannose, despite weak transport across gut or kidney, evokes significant betacytotropic effects; and 3) mannose- and fructose-induced enhancement of glucose disposal might be mediated by a factor(s) other than GIP.

Adolescent↗
PubMed1979

Zollinger-Ellison syndrome associated with parathyroid adenomas and ectopic gastric tissue in the lower esophageal mucosa.

A rare case of the Zollinger-Ellison syndrome associated with hyperparathyroidism and ectopic gastric tissue in the lower esophageal mucosa is reported. Preoperatively the patient, a 53-year-old woman, had hyperchlorhydria and her fasting serum gastrin concentration was mildly elevated. There was a considerable increase in the gastric acid output and concentration of serum calcium after secretin infusion. At operation the patient had a gastric ulcer 10 cm in diameter, an islet cell tumour of the pancreas 14 cm in diameter, and ectopic gastric mucosa in the distal third of the esophagus. A gastrectomy was perfomed, the pancreatic tumour excised and part of the distal esophagus removed through a left thoracotomy. Four months after the operation the gastrin concentration had returned to low normal, but the serum calcium values remained high. One month later two parathyroid adenomas were removed which effectively cured the hypercalcemia.

Adenoma↗