Insulin treatment improves islet function in type 2 diabetic Chinese hamsters.

To study whether normalization of hyperglycemia improves islet function in long-standing type 2 diabetes, hyperglycemic CHIG/Han subline of the genetic type 2 diabetic Chinese hamster (>15 mmol/l: n=23) were either treated with insulin implants (liberating 1 U/day) or vehicle for two weeks. Islets were isolated and incubated for 3 h in the presence of 10 mmol/l glucose with or without 0.1 mmol/l 3-isobutyl-1-methylxanthine (IBMX).

Indication and results of insulin therapy for gestational diabetes mellitus.

The aim of this study was to determine whether amniotic fluid insulin concentration (AFI) is a better parameter than mean maternal blood glucose values (MBG) for deciding about insulin therapy in patients with gestational diabetes. MBG's were calculated on the base of 9 blood glucose levels during a 24 hour period after one week of diet therapy. In a prospective trial between 1987 and 1989 in Karlsburg, 123 gestational diabetic patients were randomized into two groups.

Validation of red cell sodium-lithium countertransport measurement--influence of different loading conditions.

Increased sodium-lithium countertransport in erythrocytes from patients with long-standing type I (insulin-dependent) diabetes mellitus has been considered as an early marker of nephropathy. Since the activity and kinetics of the sodium-lithium countertransport may critically depend on loading conditions, this study was aimed at determining sodium-lithium countertransport activity, Michaelis constant Km and maximum velocity Vmax in erythrocytes loaded in two different Li+ solutions. Sodium-lithium countertransport activity was determined in erythrocytes in 8 healthy control subjects after loading with 150 mmol/l LiCl compared with those loaded with 150 mmol/l LiHCO3.

Discordant results in the assay of cytoplasmic islet cell autoantibodies with ELISA and immunohistochemical techniques.

We evaluated 6 batches of a solid phase enzyme-linked immunosorbent assay (ELISA) Isletest-ICA kit commercially available for the determination of autoantibodies to pancreatic islet cells, and compared the results with those obtained by a standardized immunohistochemical method. Following the immunohistochemical determination of autoantibodies to pancreatic islet cells, sera from patients with insulin-dependent diabetes mellitus, both positive and negative for autoantibodies to pancreatic islet cells, were randomly selected and analysed by ELISA. Sera from healthy control subjects, as well as standards recommended by the International Diabetes Workshop (IDW) ICA (Autoantibodies to Pancreatic Islet Cells) Proficiency Program, were included.

Autoantibodies to insulin and to proinsulin in type 1 diabetic patients and in at-risk probands differentiate only little between both antigens.

To answer the question whether insulin or proinsulin would be the true antigen for both insulin and proinsulin autoantibodies, displacement experiments of 125I-insulin and -proinsulin binding with both unlabeled antigens were performed in sera of four groups of antibody-positive probands: first-degree relatives of Type 1 diabetic patients, pre-Type 1 diabetic persons, recent-onset Type 1 diabetic patients, insulin-treated Type 1 diabetic patients. In subjects who were primarily screened to constitute these groups, prevalences of insulin and proinsulin autoantibodies were nearly identical. In antibody-positive sera, 125I-insulin and -proinsulin binding values in general were closely correlated to each other with regression coefficients near 1.