Showing papers by "Rosalyn S. Yalow published in 1974"

Ectopic ACTH Production in Carcinoma of the Lung

Abstract: Immunoreactive ACTH was found in almost all tissue extracts of lung carcinoma from patients without clinical evidence of Cushing's syndrome; i.e. 14 of 15 primary tumors, nine of nine metastatic lymph nodes, and four of four metastatic liver nodules contained immunoreactive ACTH. The incidence of ACTH in extracts of other tumor types was much lower. Comparable normal tissues contained no detectable ACTH. Immunoreactive growth hormone, parathyroid hormone, or gastrin was not found in the same carcinoma tissue. The predominant form of ACTH in the tumor extracts was big ACTH. In pituitary extracts little ACTH predominated.53% of 83 patients with lung carcinoma had afternoon plasma ACTH levels greater than 150 pg/ml; more than 90% of plasmas containing less than 150 pg/ml were obtained from patients who had received radiation therapy or chemotherapy. 31% of 45 patients with chronic obstructive pulmonary disease (COPD), 28% of 25 patients with other severe lung disease, and 6% of 33 controls had elevated values. Big ACTH predominated in the plasma of patients with lung carcinoma or COPD having elevated ACTH levels. Tissue from the lung of a smoking dog with atypical histologic changes contained immunoreactive ACTH, almost exclusively in the big form, while tissue from another smoking dog that was histologically normal contained no ACTH. Thus ACTH may be present even in precancerous lung lesions. These studies suggest that serial plasma ACTH levels may be of value in screening for, and/or management of, patients with carcinoma of the lung.

Big ACTH: Conversion to Biologically Active ACTH by Trypsin

Abstract: In this study the in vitro biologic activity of big ACTH as determined by an adrenal cell dispersion method is compared to its immunoreactivity before and after treatment with trypsin. Big ACTH and an ACTH-like polypeptide (little ACTH) were extracted from tumors of the lung or pancreas with boiling water and separated by Sephadex G-50 nitration. The biologic activity of big ACTH was less than 4% of its immunologic activity. In contrast, the biologic and immunologic activity of little ACTH were in good agreement. Sephadex gel nitration studies revealed that within 10 sec after the addition of trypsin to big ACTH most of the big ACTH had been degraded and a prominent little ACTH component had appeared. Concomitantly, a rapid evolution of biologic activity was demonstrated. Biologic and immunologic activity were in good agreement from the first post-trypsin sampling, when activity was maximal, and declined over the 5-min period of study. These studies support an earlier suggestion of a precursor ro...

Radioimmunoassay: Its Past, Present, and Potential

Abstract: It is indeed a great honor and pleasure for me to receive the Georg von Hevesy Medal and to present this lecture in this honor. In my Nobel lecture last year I had already acknowledged my debt to him as the scientific progenitor of my career [1]. It is my regret that I never had the opportunity of meeting him. Yet my interests in the role of radioisotopes in biomedical investigation so closely parallel his that it is almost as if Professor von Hevesy were my teacher. His book on “Radioactive Indicators” was published in 1948, just after I joined the Veterans Administration Hospital in the Bronx to establish a Radioisotope Service. Through its pages I felt that I knew him, learned from him and developed professionally under his aegis. As nuclear medicine grew and became increasingly concerned with imaging, my own interests diverged from its mainstream and remained in the development and application of radioisotope methodology to analyze the fine structure of biologic systems. Radioimmunoassay is different from but has much in common with the isotopic dilution technique which Professor von Hevesy pioneered.