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Biomedical subjects

M H Wheeler

Publications and source records attributed to M H Wheeler.

113 records · Page 7Linked to original sources
PubMedDate not supplied

Laboratory comparison of diagnostic specificity of intact hormone and region-specific immunoassays of parathyroid hormone.

A 2-site immunochemiluminometric assay (ICMA) for intact parathyroid hormone (PTH) has been developed to overcome the problems of limited sensitivity and specificity associated with conventional PTH immunoassays. The present investigation assesses the relative merits of the 2-site intact PTH (ICMA) and a midmolecule PTH radioimmunoassay (RIA). Immunoassay profiles of dispersed hyperparathyroid cell supernatants and hyperparathyroid sera obtained during parathyroidectomy and from renal failure patients, fractionated by gel filtration chromatography, facilitated a direct comparison of the specificity of PTH immunoassays. Using gel filtration matrices which permitted the separation of intact hormone, large C-terminal fragment(s), and a small midmolecule fragment in adenomatous cell supernatant and peripheral sera, the intact PTH (ICMA) assay consistently yielded a single peak of immunoreactivity. In contrast, the midmolecule RIA yielded 2 and 3 broad peaks of immunoreactivity after fractionation of serum and adenomatous cell supernatant, respectively. There was no evidence for the secretion of a small midregion fragment in vitro or its peripheral derivation in vivo. These studies demonstrate the superior specificity of the 2-site intact PTH assay compared with a midmolecule RIA and, thus, confirm the potential diagnostic superiority of the ICMA.

Calcium↗
PubMedDate not supplied

Asymptomatic primary hyperparathyroidism.

The criteria used in selecting patients with asymptomatic hyperparathyroidism (HPT) for surgery remain controversial. Do patients with asymptomatic HPT have less severe disease (smaller glands and less derangement of biochemistry) than those with symptoms? We studied a consecutive series of 111 patients with HPT surgically treated and compared the symptomatic patients (n = 83) and asymptomatic patients (n = 28). There were no significant differences between the two patient groups with respect to age, serum calcium, PTH (intact 1-84), and excised gland weights (adenomas). Hypercalcemia was cured in all patients. The natural history of mild or asymptomatic HPT is unknown, but we summarize the current knowledge relating to mortality, cardiovascular/renal disease, psychiatric and neuromuscular disorders, and bone disease. Symptoms of HPT do not correlate with the degree of biochemical and pathological derangement. Furthermore clinical assessment does not predict severity of disease and should not be the sole basis of selection for surgery. The results of surgery for primary HPT permit us to advocate a liberal approach to the selection of asymptomatic patients for operation.

Humans↗
PubMedDate not supplied

Closure of colostomy--a safe procedure?

A retrospective surgery of a series of 73 patients undergoing closure of colostomy has been carried out. Closure was complicated in 37.8 per cent of cases, and fecal fistulas occurred in 17.6 per cent. The overall mortality rate of the procedure was 2.7 per cent. The underlying disease (carcinoma or diverticulitis) did not influence the complication rate. Furthermore, intraperitoneal and ex-raperitoneal methods of closure appeared equally satisfactory. Closure of colostomy within a month of construction was associated with an unacceptably high incidence of fecal fistula of 33 per cent.

Adult↗