Induction of ornithine decarboxylase has been correlated with the onset of cellular proliferation and cAMP production. Whether the resulting increases in polyamine levels are essential mediators of growth and/or differentiation or are merely incidental remains controversial. We have used FRTL-5 thyroid cells in culture to study the effects of three growth factors on ornithine decarboxylase activity. These factors [TSH, bovine calf serum, and 12-O-tetradecanoylphorbol-13-acetate (TPA)] are thought to act through different intracellular pathways. TSH stimulates cAMP production in thyroid cells, calf serum acts through ill-defined pathways to stimulate growth, and TPA is known to activate protein kinase C. Bovine calf serum and TSH acted synergistically to induce ornithine decarboxylase activity. Activity was maximal when the phosphodiesterase inhibitor, methyl isobutyl xanthine, was included. Individually, neither serum nor TSH was a potent stimulator of the enzyme. Ornithine decarboxylase mRNA was apparent on Northern blots as a doublet following one hour of exposure to these agents. TPA did not stimulate ornithine decarboxylase activity and had an inhibitory effect on enzyme induction by TSH and serum. Difluoromethylornithine, a specific inhibitor of ornithine decarboxylase, inhibited growth induced by both TPA and TSH in putrescine-free medium. This effect was not apparent in medium containing 10(-5) M putrescine. The data indicate that, although intracellular levels of cyclic AMP regulate ornithine decarboxylase activity, a component in serum is necessary for significant induction of this enzyme. Factors stimulating growth by non-cyclic AMP-dependent pathways may act without apparently stimulating this enzyme, although polyamines appear to be essential for their growth stimulatory effects.

1-Methyl-3-isobutylxanthine↗

PubMedDate not supplied

Anterior pituitary function in women with postpartum hemorrhage.

Thirteen asymptomatic women with postpartum blood loss of at least 500 cc were evaluated for anterior pituitary endocrine function. Insulin tolerance tests and TRH stimulation tests were done and determinations made for serum growth hormone, cortisol, thyrotropin, and prolactin. There was no laboratory evidence of pituitary dysfunction in this group of 13 patients. Subclinical hypopituitarism in women with previous postpartum hemorrhage would appear to be uncommon.

Adult↗

PubMedDate not supplied

The incidence of carcinoma in solitary "cold" thyroid nodules.

Two hundred and three patients with single thyroid nodules were referred for radioactive scan of the thyroid. Solitary "cold" nodules were identified in 130 patients and 68 of these patients came to surgery. Of this group, 12 patients were found to have carcinoma. There was no obvious selection process which distinguished the 68 patients who underwent surgery from the 62 who did not. There is a significant risk of thyroid neoplasms occurring in patients with solitary "cold" nodules, and this is particularly true in patients under forty.

Adult↗

PubMedDate not supplied

Intellectual development in children whose mothers received propylthiouracil during pregnancy.

Standard intelligence tests were administered to twenty-eight children who had been exposed to PTU in utero and thirty-two non-exposed siblings. There was no significant difference in results between the two groups. The present study suggests that with careful attention, pregnant women with thyrotoxicosis can be treated with propylthiouracil without interfering with subsequent intellectual development in the offspring.

Adolescent↗

PubMedDate not supplied

Truth and fancy in the management of the solitary thyroid nodule.

Although there is considerable controversy about the proper management of the solitary nodule, certain information may be useful in reaching this decision. Age, sex, and a previous history of external irradiation to the head and neck are helpful as are the clinical characteristics of the thyroid gland. Whether the nodule is functioning or "cold" on thyroid scan, and cystic or solid on thyroid ultrasound is also helpful. Based on these findings, the physician must decide whether to recommend surgery or thyroid hormone suppressive therapy.

Biopsy↗

PubMedDate not supplied

Goiter in Tibetan medicine.

The visit of two Tibetan physicians provided a unique opportunity to gain insight into a practice of medicine very different from that of Western civilization. Initial discussions indicated that the practice of medicine and mysticism were inextricably interwoven in the Tibetan culture. Accordingly, the focus of the study was directed to goiter, which is both common in the Himalayas and easy to define.In Tibetan medical practice, illness is considered to be derived from both proximate and distant causes. Three humors, "wind," "bile," and "phlegm" are thought to be responsible for normal mental and physical functions when in balance, but disease when out of balance. Goiter was thought to be due to an imbalance of these humors. The Western discovery that endemic goiter in the Himalayas was due to iodine deficiency explained the proximate cause but did not explain why some individuals have goiter and others do not in the same iodine deficient village.

China↗