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Biomedical subjects

M K Fleetwood

Publications and source records attributed to M K Fleetwood.

7 recordsLinked to original sources
PubMed1998

Use of a rapid intraoperative parathyroid hormone assay in the surgical management of parathyroid disease.

OBJECTIVE: To evaluate the utility of a rapid intraoperative parathyroid hormone (PTH) immunoradiometric assay in the surgical management of parathyroid disease, particularly with reference to limiting extent of cervical exploration. DESIGN: Nonrandomized prospective study. SETTING: Academic tertiary care center. PATIENTS: Forty-three consecutive patients undergoing parathyroid exploration for adenoma or hyperplasia had rapid PTH assays performed from blood drawn at induction and 7 minutes after resection of all hyperfunctioning parathyroid tissue. OUTCOME MEASURES: Excision of all hyperfunctioning parathyroid tissue as assessed by bilateral neck exploration, postoperative normalization of serum calcium and PTH levels, and resolution of clinical symptoms. RESULTS: The intraoperative rapid PTH assay accurately reflected whether all hyperfunctioning parathyroid tissue was excised in every patient. In 41 patients, all hyperfunctioning parathyroid tissue was resected at the time of surgery and confirmed by a corresponding decrease in the intraoperative postexcision rapid PTH determination as well as by subsequent normalization of postoperative serum calcium and PTH levels and resolution of clinical symptoms. In 2 patients, the postexcision rapid PTH assay determination was not consistent with removal of all hyperfunctioning parathyroid disease and both patients demonstrated persistent hyperparathyroidism postoperatively. CONCLUSIONS: The intraoperative rapid PTH assay may be of significant benefit in permitting directed unilateral parathyroid explorations for adenoma when combined with preoperative localization with a technetium-99m sestamibi scan. Additionally, the rapid PTH assay has proved to be of benefit in confirming excision of all hyperfunctioning parathyroid tissue in patients with multiple gland hyperplasia, particularly those who may harbor ectopic parathyroid tissue.

Adenoma↗
PubMed1990

The effects of radioisotopes used in nuclear medicine on diagnostic radioimmunoassay testing. Is there any significant interference?

The administration of radioisotopes for diagnostic nuclear medicine scans and therapeutic procedures is quite prevalent today. A period of interference with the counting of a radioimmunoassay [RIA] test may occur with the serum of a patient receiving an in vivo radionuclide that decays by gamma emission. Because the logistics of precounting all specimens may be cumbersome and prohibitive, it is important to determine the degree of this interference. In this study, the authors evaluate the potential interference of the most commonly used radioisotopes with RIA studies. For two months (March and August 1988) 10,650 patient serum specimens were counted for significant background gamma radiation before RIA testing. Forty-three patients, on whom 105 RIA tests were performed, were identified as having preassay gamma radiation in their serum. With the use of selective energy windows for each different interfering radionuclide, proportional determinations were made as to the amount of interfering gamma radiation spilling into the iodine 125 test marker window. It was shown that initial whole serum pretest gamma counts as high as 111,000 counts/minute did not significantly affect the results of the RIA. Because of the meticulous washing and decanting procedures required in modern RIA and the monoclonal nature of most antibodies used currently, it appears the degree of nonspecific binding of this potentially interfering radiation is minuscule. The energy level of cobalt 57, however, and many of the other commonly used radioisotopes, overlaps so closely that it is difficult to window for this interference. It is possible, therefore, that this distinction cannot be made and folate and vitamin B12 test systems using cobalt 57 markers may have to be routinely prescreened. The authors conclude that the requirement for prescreening of all RIA test samples for interfering gamma radiation is unnecessary (1987 CAP Commission on Laboratory Accreditation Inspection Checklist, Section VII, Question 07.0290).

Diagnostic Techniques, Radioisotope↗
PubMed1983

Plasma DNA in the diagnosis of pulmonary embolism.

To assess the diagnostic value of measuring free plasma deoxyribonucleic acid (DNA) in patients suspected of having pulmonary embolism, we prospectively assayed the plasma of 40 consecutive patients who underwent pulmonary angiography for the presence of free plasma DNA. Fifteen of them had angiographic evidence of pulmonary embolism. Of these 15 only two (13%) had a positive result in the test for free double-stranded plasma DNA. We concluded that measuring free double-stranded plasma DNA is of no value in the diagnosis of pulmonary embolism.

DNA↗
PubMed1975

Effect of metabolic inhibitors on pyrogen production by rabbit leukocytes.

The metabolic inhibitors, actinomycin D, cycloheximide, puromycin dihydrochloride, puromycin aminonucleoside, and p-fluorophenylalanine did not inhibit the release of leukocytic pyrogen whether endotoxin was preincubated with cells for 20 min at 37 degrees C before addition of inhibitor or inhibitor was preincubated with cells for 1 hr before addition of endotoxin. On the other hand, cortison inhibited release of pyrogen under both experimental conditions. Poly(I): poly(C) was not effective in inducing rabbit leukocytes to produce an endogenous pyrogen.

Animals↗