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Biomedical subjects

S J Marx

Publications and source records attributed to S J Marx.

At least 217 records · Page 12Linked to original sources
PubMed1978

Reoperative parathyroid surgery for persistent hyperparathyroidism.

In a 2-year period 30 patients with persistent hyperparathyroidism following 59 prior unsuccessful procedures underwent reoperation. Preoperative arteriography was useful in planning the surgical approach in 56%, and retrospectively was correct in 63%. Selective venous catheterization gave localizing information in 83%, correctly predicting site or side in 60% of the total. Computerized axial tomography was helpful in identifying mediastinal glands before operation. Reoperation was successful in rendering the patient hypocalcemic or normocalcemic in 83%. Of the 11 patients (37%) who were rendered profoundly hypocalcemic, two were subsequently weaned from vitamin D and calcium support; seven have received either fresh or cryopreserved parathyroid autografts. Persistent hyperparathyroidism is a difficult surgical problem which we believe warrants aggressive localization attempts prior to operation. Autotransplantation with cryopreserved parathyroid tissue may be of value in the long-term management of the high incidence of postoperative hypocalcemia in this patient group.

Adenoma↗
PubMed1977

Family studies in patients with primary parathyroid hyperplasia.

The relatives of 25 index patients with primary parathyroid hyperplasia were tested for hypercalcemia. At least 13 of these patients had one or more first degree relatives with hypercalcemia. Two familial syndromes each with autosomal dominant transmission were recognized. Two index patients were part of large kindreds categorized as having familial hypocalciuric hypercalcemia (FHH). Manifestations of multiple endocrine neoplasia type I were present in the kindreds of at least four other index patients (FMEN I). In seven other kindreds there were too few affected members to allow definitive classification. Differences between manifestations of FHH and FMEN I were described. Among offspring of affected persons in kindreds with FHH, as distinct from FMEN I, the prevalence of hypercalcemia approached the theoretic maximum of 50 per cent during the first two decades. In FHH, nephrolithiasis and peptic disease were unusual; moderate hypercalcemia occurred without hypercalciuria; and subtotal parathyroidectomy did not abolish hypercalcemia. Concentrations of peptide hormones other than parathyroid hormone (PTH) were normal in those with FHH; in FMEN I high concentrations of glucagon in plasma were found in five of six patients tested, and high concentrations of gastrin were found in three of 12 patients. Hypergastrinemia generally accompanied obvious peptic disease. Distinction of the two conditions is important since patients with FHH may not benefit from subtotal parathyroidectomy, but they generally have a better clinical prognosis than do patients with FMEN I.

Adolescent↗
PubMed1977

The blood supply of mediastinal parathyroid adenomas.

Arteriography for parathyroid localization following unsuccessful neck surgery should include selective catheterization of the inferior thyroid and internal mammary arteries bilaterally. When the arterial supply to a mediastinal adenoma arises from the internal mammary artery, recovery from the neck may not be possible and an open mediastinal exploration (or embolization) should be considered.

Adenoma↗
PubMed1977

Computed tomography for parathyroid localization.

Computed tomography (CT) of the neck and mediastinum was performed in 10 patients with primary hyperparathyroidism. Nine had undergone previous surgery and were considered localization problems. Of four subsequently proven cervical adenomas, only one unusually large 19-g adenoma was visualized by CT. However, of two subsequently proven anterior mediastinal adenomas, CT scanning was positive in both; a single posterior mediastinal adenoma was not demonstrated. Of the remaining three patients, one was not operated on; in two others no adenoma was found at surgery. CT scanning is recommended prior to neck surgery in all patients with primary hyperparathyroidism to identify adenomas in the anterior mediastinum.

Adenoma↗
PubMed1977

Scleral calcifications in hyperparathyroidism: demonstration by computed tomography.

Scleral calcifications were demonstrated roentgenographically in two patients with known hyperparathyroidism and clinically normal eyes. In one of these patients, scleral calcification was evident both on plain films and with computed tomography (CT). In the second patient, a solitary plaque of calcified sclera was visible only by CT. Histopathologic examination of the eyes of a third hyperparathyroid patient who died during surgery demonstrated calcium plaques in the posterior sclera consistent with the CT appearance of the sclera in the other patients.

Adult↗
PubMed1977

Benign breast dysplasia causing hypercalcemia.

An adolescent female had hypercalcemia and massive, bilateral breast enlargement. At neck and mediastinal explorations three parathyroid glands were removed and found to be histologically normal. Following bilateral mastectomy the hypercalcemia resolved within two days and did not recur during a six-year period of followup. Microscopic examination of the excised breast tissue revealed marked dysplasia but no cancer. Those findings suggest that benign, dysplastic breast tissue can release humoral mediators of hypercalcemia.

Adolescent↗
PubMed1975

Intrathyroidal parathyroid adenoma or hyperplasia. An occasionally overlooked cause of surgical failure in primary hyperparathyroidism.

In six surgically proved intrathyroidal parathyroid tumors, neither thyroid scan nor gross appearance of the thyroid at surgery allowed reliable detection of parathyroid glands wholly within the thyroid. Preoperative selective catheterization of thyroid veins with radioimmunoassay for parathyroid hormone facilitated successful removal of hyperfunctioning intrathyroidal parathyroid tissue in all five cases in which it was performed.

Adenoma↗
PubMed1975

The localization of abnormal mediastinal parathyroid glands.

The venous drainage of parathyroid glands ectopically located in the mediastinum is generally caraniad into the inferior thyroid veins. Parathyroid glands in the neck can cause elevated concentrations of parathyroid hormone in mediastinal veins because of thyroidalthymic anastomoses. Therefore venous sampling alone cannot distinguish cervical from mediastinal adenomas. Arteriography can localize mediastinal parathyroids and should be perfomred before any repeat exploration.

Adenoma↗
PubMed1975

Treatment of hyperparathyroidism by percutaneous embolization of a mediastinal adenoma.

Percutaneous embolization of parathyroid adenomas was attempted in three hypercalcemic patients with previously unsuccessful neck explorations. Two adenomas were in the mediastinum and the third was within the thyroid lobe. Autologous clot, Gelfoam, and silicone rubber were used to obstruct feeding arteries. The intrathyroidal adenoma failed to respond but both mediastinal adenomas were infarcted. Hyperparathyroidism recurred after 7 months in one patient but the other remains normocalcemic 8 months postembolization.

Adenoma↗
PubMed1975

Renal receptors for calcitonin: coordinate occurrence with calcitonin-activated adenylate cyclase.

High affinity binding of 125I-labeled salmon calcitonin ([125I]SCT) and calcitonin-activated adenylate cyclase were detectable in renal plasma membranes from the rat. Addition of 5'-guanylyl-imidodiphosphate lowered the threshold for enzyme activation by peptide hormones. Renal plasma membranes from man, dog and cow contained little or no calcitonin-sensitive adenylate cyclase and showed no high affinity binding of [125I]SCT. High affinity binding sites were distributed during membrane fractionation in fractions where the specific activity of hormone-sensitive adenylate cyclase was greatest. Calcitonin binding and activation of the adenylate cyclase enzyme occurred at similar hormone concentrations. The relative potencies of calcitonin analogues were similar whether measured by competition for high affinity binding sites or by effect on adenylate cyclase. Low concentrations of Lubrol-PX, a nonionic detergent, did not affect catalytic function of the enzyme determined in the presence of sodium fluoride but caused parallel loss of high affinity [125I]SCT binding and hormonal sensitivity of the enzyme. This observation provided further evidence that interaction of calcitonin with specific receptors (identified with [125I]SCT binding) is essential for calcitonin activation of adenylate cyclase, but showed that catalytic activity of enzyme does not require functioning hormone receptors.

Adenylyl Cyclases↗
PubMed1975

Total body retention of orally administered 47-calcium in primary hyperparathyroidism.

Using a whole body radiation detector, we have measured the total body retention of 47-Ca 7 days after oral administration of the isotope to patients with various disorders of calcium metabolism. The percent retention of 47-Ca given with 90 mg of unlabeled (carrier) calcium varied with the calcium metabolic status as follows: normals (n equals 14), 33-43 percent (mean 38); primary hyperparathyroidism (n equals 28), 32-74 percent (mean 52); idiopathic hypercalciuria (n equals 9), 34-49 percent (mean 42); and hypercalcemia of other etiology (n equals 3), 23-26 percent (mean 25). Almost half (13/28) of those with hyperparathyroidism showed a retention above 55 percent, distinguishing them from subjects with idiopathic hypercalciuria. Retention of 47-Ca correlated poorly with clinical measures of severity of hyperparathyroidism. When isotope was diluted with a smaller amount of carrier calcium (20 mg), retention was increaseed in normals (n equals 5) to 46-54 percent (mean 50) and in hyperparathyroidism (n equals 5) to 64-87 percent (mean 73). After surgical cure of hyperparathyroidism retention of isotope returned toward normal in 5 of 7 subjects. Whole body retention of orally administered 47-Ca may prove useful in detecting hyperparathyroidism in subjects with mild hypercalcemia or hypercalciuria.

Administration, Oral↗