[Concentration of C-peptide and insulin in serum of patients with acute virus hepatitis (author's transl)]. / C-Peptide- und Insulinkonzentration im Serum bei akuter Virushepatitis.

Intravenous glucose tolerance tests were performed in 10 patients with acute virus hepatitis. The assimilation coefficient of glucose and the level of insulin and C-peptide in serum were determined before and in the course of the glucose tolerance tests. In comparison to healthy normal weight persons C-peptide concentration in patients with acute hepatitis increased twice as high whereas the pattern of insulin secretion did not differ significantly. The higher levels of C-peptide indicate an increase of the beta-cell secretion in acute hepatitis. One could suppose an increased hepatic destruction of insulin in acute hepatitis, because there is no significant difference among the insulin levels. More likely, there is a reactive increase of secretion of the beta-cell due to a reduction of insulin sensitivity and this is indicated much better by C-peptide- than insulin levels because of the longer half live of the the C-peptide molecule.

[Studies on the question of a possible autoregulation of insulin secretion (author's transl)]. / Untersuchungen zur Frage einer Autoregulation der Insulinsekretion.

In eight normal weight healthy volunteers it was proved by C-peptide assay whether high concentrations of insulin in serum would suppress the secretion of insulin in an autoregulative manner. Insulin combined with glucose, therefore was given intravenously as a single bolus injection as well as an infusion over a period of two hours. Moreover it was proved whether high levels of insulin would suppress the reactivity of the B-cell to sulphonylurea administration. It was demonstrated that the secretion of the B-cell is regulated only by the concentration of the blood sugar, but not by the level of serum insulin. Likewise the stimulation of the B-cell by sulphonyl-urea administration is not suppressed by high concentrations of insulin.

[Value and relevance of metabolic function tests in the diagnosis of primary hyperparathyroidism (author's transl)]. / Wertigkeit verschiedener Stoffwechselparameter bei der Diagnostik des primären Hyperparathyreoidismus

Calcium, phosphate and alcaline phosphatase levels were determined in the serum of 29 patients with suspected primary hyperparathyroidism. Phosphate clearance according to Kyle, 24 hours urine hydroxyproline excretion during collagen free diet, the excretion of cAMP in the 24 h urine during calcium restricted diet were examined with regard to the diagnostic value and relevance as compared to the consumption of laboratory and staff time. The elevation of the serum calcium levels are not specific and only of minor diagnostic value. It has been found that the highest diagnostic value is given by the Kyle-test using 15 mg Ca ions/kg body weight. No false positive results were recorded. The excretion of hydroxyproline and calcium are only of limited value. Serum alcaline phosphatase and cAMP excretion have no diagnostic significance whereas concentration of serum phosphate may have some value.