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Biomedical subjects

L Shenkman

Publications and source records attributed to L Shenkman.

At least 91 records · Page 5Linked to original sources
PubMed1977

Hyperthyroidism after propranolol withdrawal.

Classic features of thyrotoxicosis developed in three patients with no prior history of thyroid disease shortly after the discontinuation of therapy with or decrease in doseage of propranolol hydrochloride. Graves' disease probably developed fortuitously after propranolol therapy was instituted, but the beta-adrenergic blockade masked the clinical features of hyperthyroidism. On discontinuation of propranolol therapy or decrease in propranolol dosage, previously latent thyrotoxicosis became manifest. If hyperthyroidism masked by beta-blockade is not recognized before withdrawal of propranolol therapy in patients with ischemic heart disease, the sudden appearance of thyrotoxicosis may lead to symptoms of increased myocardial ischemia.

Adult↗
PubMed1977

Serum prolactin and hypothalamic dopamine in rat strains selectively bred for differences in susceptibility to stress.

Rat strains selectively bred for behavioral differences in susceptibility to mild stress exhibited differences in serum prolactin (Prl) and hypothalamic dopamine (DA). Male rats from the Maudsley Reactive (MR) strain had higher levels of serum Prl and hypothalamic DA than rats from the Maudsley Non-Reactive (MNRA) strain. MR rats also showed a greater percentage increase in serum Prl 1 h after blockade of catecholamine synthesis by administration of alpha-methylparatyrosine (alphaMpT). The correlation of basal serum Prl levels with individual susceptibility to stress constitutes further evidence that Prl may play a functional role in the organism's response to stress. Strain differences in hypothalamic DA function may play a role in the etiology of strain differences in serum Prl.

Animals↗
PubMed1976

Antibodies to Yersinia enterocolitica in thyroid disease.

The prevalence of elevated antibody titers against Yersinia enterocolitica was studied in normal subjects, patients with a variety of nonthyroidal illnesses, and patients with thyroid disease. In contrast to the low prevalence of antibodies in controls (less than 8%), 48 of 67 patients (75%) with a variety of thyroid disorders had titers greater than 1:8. Antibodies were found in 24 of 36 patients with Graves' disease, five of six with autonomous adenoma, seven of seven with Hashimoto's thyroiditis, three of five with idiopathic primary hypothyroidism, four of 11 with nontoxic nodular goiter, and one of two with thyroid carcinoma. Antibodies to serotype 3 were the most prevalent, occurred in the highest titers, and were found particularly in patients with Graves' disease. These observations indicate that in spite of the infreqent occurrence of yersinia infection in the United States as compared with Scandinavia, patients with thyroid disorders have a higher prevalence of antibodies to Yersinia than normal subjects or patients with other disorders.

Adenoma↗
PubMed1975

Effect of methylergonovine on puerperal prolactin secretion.

Serum prolactin concentration was measured by radioimmunoassay in 29 women, in the first 1 1/2 hours postpartum. Fourteen women received 0.2 mg methylergonovine maleate (Methergine) intramuscularly after the delivery of the placenta. Fifteen women who served as controls received only saline. The rise in serum prolactin concentration seen in the control women (266.4 ng/ml +/- 40.8 SE) was significantly greater than that seen in methylergonovine-treated patients (141.0 ng/ml +/- 29.0. SE).

Female↗
PubMed1975

Measurements of the effective thyroxine ratio (ETR) in the neonate, infant, and child.

The applicability of the effective thyroxine ratio (ETR) was assessed in euthyroid neonates, infants, and children. ETR determinations on cord blood fell within the normal adult range. In contrast, ETR values of newborns age 4 hr to 2 days were all elevated (1.17 -1.37) and within the hyperthyroid range for adults. Values in infants age 2 weeks and older and in children age 1-15 years all fell within the normal adult range. These findings suggest that the ETR can be used as an ancillary measure of thyroid function in infants and children. In the immediate postpartum period, however, ETR values may be normally in the adult hyperthyroid range.

Adolescent↗
PubMed1974

Prostaglandins stimulate thyroid function in pregnant women.

Intravaginal or intravenous administration of prostaglandin F(2alpha) to pregnant women produced significant elevations of plasma triiodothyronine and thyroxine concentrations, but no rise of thyrotropin. These observations are consistent with those of previous in vitro studies indicating that prostaglandins can act directly on the thyroid gland to stimulate thyroid hormone synthesis or release, or both.

Female↗
PubMed1973

Modulation of pituitary responsiveness to thyrotropin-releasing hormone by triiodothyronine.

The relative roles of triiodothyronine (T(3)) and thyroxine (T(4)) in modulating pituitary responsiveness to thyrotropin-releasing hormone (TRH) have been assessed. (a) 10 hyperthyroid patients with elevated serum T(2) and T(4) levels showed no pituitary response to TRH. After 2 wk of propylthiouracil therapy T(4) levels had fallen to normal in only five patients while T(2) levels were normal in all. Pituitary responsiveness to TRH returned in all patients with normal or high T(4) concentrations. (b) Patients with isolated elevations of serum T(3) (T(3) toxicosis) failed to respond to TRH. TRH responsiveness was restored when T(3) levels fell to normal after propylthiouracil therapy. (c) When pituitary responsiveness to TRH was tested 60 min after a single oral dose of 50 mug of T(3), which increased serum T(3) levels to slightly above the normal range, no rise in thyrotropin (TSH) was seen in six subjects. These findings indicate that T(3) elevations alone can rapidly inhibit pituitary responsiveness to TRH.

Administration, Oral↗