Relative biologic activities of human and bovine parathyroid hormones and their synthetic, NH2-terminal (1-34) peptides, as evaluated in vitro with renal cortical adenylate cyclase obtained from three different species

The relative biologic activities of native human parathyroid hormone, hPTH (1-84), native bovine parathyroid hormone, bPTH (1-84), and their respective synthetic, NH2-terminal, biologically-active (1-34) fragments were compared in vitro using adenylate cyclase preparations from human, chicken, and rat renal cortex. The concentrations of the hormones required for half-maximal stimulation of the enzymes were determined from dose response curves. bPTH (1-84) had greater apparent activity than hPTH (1-84), using rat or chicken renal adenylate cyclase, but, with human renal adenylate cyclase, the apparent activities of the two hormones were equal. Synthetic hPTH (1-34) possessed about 1/10 of the apparent activity of hPTH (1-84) in all three adenylate cyclase systems. However, (GLU22)bPTH (1-34) was about equal inapparent activity to bPTH (1-84) in the three systems. We propose that different rates of hormone degradation at or near renal receptor sites may be responsible for the dependence of the relative biologic activity on the assay system used. In the case of hPTH a peptide chain longer than (1-34) may be required for the full biologic activity of the hormone...     

The role of coloscopy in the differential diagnosis between idiopathic ulcerative colitis and Crohn's disease of the colon

The authors point out the striking significance of coloscopy in establishing a correct diagnosis of inflammatory diseases of the colon. In particular, the most valuable endoscopic features are indicated which may permit distinguishing between idiopathic ulcerative colitis and Crohn's disease of the colon. Differentiation between these two diseases cannot always be achieved by means of available diagnostic procedures other than coloscopy. Moreover, the endoscopic findings enable an assessment to be made of the extent, stage, severity and course of either disease. The authors' experience encompass 2,478 coloscopy examinations: the observed cases of idiopathic ulcerative colitis are 182, those of Crohn's disease of the colon are 104.