Showing papers by "Rosalyn S. Yalow published in 1984"
TL;DR: Fractionation on Sephadex G50 gel of methanol extracts of rat intestine revealed two molecular forms of cholecystokinin of about equal immunopotency: one has an elution volume between CCK33 and CCK12; the other elutes in the salt region as does authentic CCK8.
70 citations
TL;DR: COOH-terminal immunoreactive cholecystokinin in methanol and acid extracts of brain and gut in the developing rat between 3 and 28 days after birth and in the adult has been fractionated on Sephadex G50.
26 citations
TL;DR: Three of the 14 patients with hypoglycemia whose diagnosis was clarified by the use of a species-specific insulin radioimmunoassay had hyperinsulinemia as the result of excessive human insulin release and were found to have either intrinsic pancreatic disease or secretagogue-mediated insulin release.
Abstract: Hypoglycemia when associated with hyperinsulinemia is usually a consequence of an insulinoma or the administration of either insulin or an insulin secretagogue. This report describes 14 patients with hypoglycemia whose diagnosis was clarified by the use of a species-specific insulin radioimmunoassay. Eleven of the 14 patients had elevated levels of animal insulin due to surreptitious accidental or malicious administration of insulin. Three of the 14 patients had hyperinsulinemia as the result of excessive human insulin release and were found to have either intrinsic pancreatic disease or secretagogue-mediated insulin release. (JAMA1984;252:2730-2734)
18 citations
TL;DR: These results are in marked contrast with the ontogeny of these hormones in the rat in which brain concentrations of CCK and VIP in the neonate are less than 10% of adult levels and in which there are age-related changes in the content of these hormone in the duodenum as well.
13 citations
TL;DR: A single determination of renal gastrin clearance and 24-hour gastrin urinary output appears to be sufficient for the determination of averaged plasma gastrin levels in normal subjects without renal disease, and should be applicable to a variety of other peptidal hormones.
Abstract: Gastrin can readily be concentrated from 10 to 50 ml of urine with better than 90% recovery using octadecylsilyl (ODS) silica columns (C18 Sep-Pak cartridge) and then measured by radioimmunoassay. Fractionation on Sephadex G50 gel filtration reveals that the apparent immunoreactivity is not due to nonspecific interference in the assay system but does correspond to the two known forms of gastrin, the 17 and 34 amino acid peptides. Renal clearance of gastrin in 5 normal subjects does not appear to differ in the fasted and fed state and ranged from 0.09 to 0.26 ml/min with an average of 0.16 +/- 0.05 (S.D.) ml/min. Urinary gastrin excretion in the overnight fasting state was generally less than 0.005 pmol/hr/kg body weight and fell to lower levels after a 20-hour fast. Increased urinary gastrin output was observed following feeding. Gastrin output in urine in 7 subjects ranged from 6.8 to 10.2 pmol/24 hr with an average of 8.5 +/- 1.5 (S.D.) pmol/24 hr. A single determination of renal gastrin clearance and 24-hour gastrin urinary output appears to be sufficient for the determination of averaged plasma gastrin levels in normal subjects without renal disease. Similar methodology should be applicable to a variety of other peptidal hormones as well.
6 citations
TL;DR: The Michaelis constants (Km's) and maximum reaction velocities (Vmax's) for the degradation of beef insulin by livers from frogs, guinea pigs, rats, a rabbit, a dog and a pig were determined.
3 citations
TL;DR: The possible value of mass screening for carcinoma of the lung by the detection of precursor adrenocorticotropic hormone (ACTH) in plasma was tested, but the usefulness was limited by the potential for false‐positives.
Abstract: The role of radioimmunoassay (RIA) in the diagnosis and management of endocrine tumors, such as pituitary tumors, insulinomas, and gastrinomas, has long been well established. A variety of nonendocrine tumors are capable of elaborating one or more humoral substances that resemble immunologically well-known, well-characterized biologically active hormones or their prohormone precursors or metabolic products. The possible value of mass screening for carcinoma of the lung by the detection of precursor adrenocorticotropic hormone (ACTH) in plasma was tested. However, the usefulness was limited by the potential for false-positives, i.e., elevation of marker concentration in the plasma of heavy smokers even in the absence of invasive carcinoma. Although on occasion a dramatic decrease of plasma ACTH after surgical resection or on some chemotherapeutic schedules has been observed, this does not occur with sufficient regularity to serve definitely as an objective measure of efficacy of therapy. The limitations of nonhormonal tumor markers, such as carcinoembryonic antigen (CEA), are also considered. Cancer 53:1426-1431, 1984.
1 citations