Tumor-promoting phorbol esters affect production of prolactin and growth hormone by rat pituitary cells

GH4C1 cells are strain of rat pituitary cells which synthesize and secrete both PRL and GH. Phorbol esters, which are potent tumor promoters in mouse skin and have diverse actions in a variety of cell and tissue systems, were found to alter hormone production by GH4C1 cells. 12-O-Tetradecanoylphorbol-13-acetate (TPA), the most potent phorbol ester, stimulated both PRL synthesis and release. The synthesis of PRL was stimulated 2.3- to 6.2-fold over control values after 3 days of treatment; the ED50 for TPA was 8.9 +/- 2.1 nM (5.5 +/- 1.3 ng/ml). The release of stored PRL was stimulated within 10 min of the addition of 100 ng/ml TPA to the culture medium. Maximum stimulation of release was 1.3- to 2.3-fold over control, and the ED50 for TPA was 13.2 +/- 2.3 nM (8.1 +/- 1.4 ng/ml). Another tumor-promoting phorbol ester, phorbol 12,13-didecanoate (PDD), stimulated PRL synthesis and release to the same maximum extent at TPA, but two biologically inactive compounds, 4 alpha-PDD and phorbol, had no effect. The stimulation of PRL release by TPA was a Ca++-dependent process; Co++, a competitive antagonist of Ca++, at 2.0 mM blocked completely the stimulation of PRL release by 100 ng/ml TPA, and this block was overcome by 2.0 mM Ca++, but not by 2.0 mM Mg++. Although phorbol esters stimulate prostaglandin (PG) synthesis in certain other cells types, PGs were not required for TPA action in GH4C1 cells. Indomethacin, a PG cyclooxygenase inhibitor, at 200 ng/ml did not inhibit the stimulation of PRL synthesis and release by TPA. Furthermore, there was no detectable (less than 50 pg/ml) PGE2 or PGF2 alpha in the medium of control or TPA-treated cells. In GH3 cells, a related cell strain, TPA (100 ng/ml) decreased GH production in both control and hydrocortisone-stimulated cells to 35% of untreated control values after 3 days of incubation. TPA also altered cell morphology, but had little or no effect on cell growth. We conclude that GH cells provide a useful system to study the mechanisms of phorbol ester action on differentiated functions.

Surgical manifestations and results of treatment of pulmonary coccidioidomycosis

Fifty consecutive patients with pulmonary coccidioidomycosis undergoing operation in an eight-year period were analyzed with regard to clinical and roentgenographic indications, surgical procedure, complications, and recurrence. Surgical indications could be divided into operation necessary primarily for diagnosis (22 out of 50, 44%) and operation because of suspected residual complications of coccidioidomycosis requiring therapy (28 out of 50, 56%). Of 16 patients with solitary nodules, 2 had lobectomy and 14 had wedge resection with no recurrence. Of 24 patients with coccidioidomycosis cavities, 14 underwent lobectomy and 10 had lesser resections, with three recurrences. Results indicate that (1) resection for primary pulmonary coccidioidomycosis for both diagnosis and therapy is associated with low perioperative risk, (2) routine administration of amphotericin is not indicated, (3) skin tests, serological study, bronchoscopy, and mediastinoscopy may not be diagnostic, and (4) lobectomy is not necessarily indicated since lesser resections are associated with equally low recurrence and complications rates.

Preliminary report of the lung cancer detection program in New York

The early lung cancer detection program in New York is described, and preliminary prevalence rate data are reported. Cigarette-smoking men over the age of 45, who are considered at high risk, are encouraged to enroll in the program and, to date, 6,612 have done so. These men receive PA and lateral chest x-rays annually, while a randomly selected sub-population of about half also have sputum cytology every four months. A controlled study of sputum cytology as an adjunct to the chest x-ray is now in progress. There were 15 cases of late lung cancer (pathologic stages II and III) detected at the initial examination, and 11 early cases (pathologic stages O and I). In the population of 3,387 men who had x-rays alone there were three early lung cancers detected; in the population of 3,225 men who had both examinations four early cancers were detected by x-ray and four by cytology. In addition, three cases of larynx cancer were detected by cytology. The early lung cancers detected by x-ray were peripheral and most were bronchiolar or adenocarcinoma; the early cancers detected by cytology were central epidermoid carcinoma of major bronchi. No early carcinomas were detected by both techniques. These findings suggest that a combination of chest x-rays and sputum cytology can be more effective than either one alone in detecting early lung cancer.

Correction for Regression on a Secondary Trait As a Method of Increasing the Efficiency of Selective Breeding

A revised estimate is given for the efficiency of a selection index investigated by Rendel (1954) which corrects the variations in a particular trait for linear regression on another.