Search PubMed⌕ Search

Biomedical subjects

A E Kitabchi

Publications and source records attributed to A E Kitabchi.

At least 145 records · Page 8Linked to original sources
PubMed1970

The biological and immunological properties of pork and beef insulin, proinsulin, and connecting peptides.

The recently discovered hormone precursors, pork and beef proinsulins, their respective connecting peptides, and beef proinsulin intermediates have been compared to insulin in their ability to stimulate the conversion of glucose-U-(14)C to (14)CO(2) and lipids in isolated fat cells. The concentrations of beef and pork proinsulins required to achieve the same biological effect were respectively, 15 and 10 times that of insulin. Beef proinsulin intermediates required only 2.6 times the concentration of insulin for the same effect. Pork and beef connecting peptides in high or low concentrations alone or in combination with proinsulin, insulin, or proinsulin intermediates showed no biological effect on the isolated fat cell system. The insulin-like activity of beef and pork proinsulins on the isolated fat cell system was not abolished with pancreatic trypsin or kallikrein inhibitors. Pork insulin antiserum inhibited the biological activity of pork insulin and proinsulin as well as that of beef insulin or proinsulin. Pork proinsulin antiserum also inhibited the insulin-like activity of both pork insulin and proinsulin. By the radioimmunoassay method, pork insulin antiserum bound only (1/4) to [unk] as much proinsulin as insulin. Beef proinsulin intermediates, on the other hand, were found to react with the pork insulin antiserum to an extent nearly equal to that of insulin. These data suggest that (a) proinsulin exhibits its effect on the isolated fat cells independent of its conversion to insulin, (b) connecting peptides have no biological effect under present experimental conditions, and (c) in comparison to insulin, immunological reactivity of proinsulin is greater than its biological activity using our pork insulin antiserum; thus, the comparison of antibody specificity with the fat cell receptor specificity suggests that the biological site of action is different from the immunologic site.

Adipose Tissue↗
PubMedDate not supplied

Accelerated insulin degradation: an alternate mechanism for insulin resistance.

We have examined insulin and glucagon degrading activities of muscle and fat tissues in 11 subjects (4 lean controls, 3 insulin-resistant obese subjects, 2 non-insulin-dependent diabetic subjects, and 2 insulin-treated diabetic subjects) and correlated degrading activity with (1) basal insulin level and (2) state of insulin resistance. We found hyperinsulinemia and insulin resistance to be significantly correlated with accelerated insulin and glucagon degrading activity. Weight reduction in an insulin-resistant obese patients results in parallel reduction in both basal insulin level and insulin-glucagon degrading activity. These data are consistent with the hypothesis that an alternative mechanism for insulin resistance may be an accelerated insulin degradation at the level of target tissues.

Adipose Tissue↗
PubMedDate not supplied

Evaluation of a portable insulin infusion pump for outpatient management of brittle diabetes.

Three "brittle" diabetic patients were given constant subcutaneous insulin infusion with a portable battery-driven pump, and their plasma glucose and hemoglobin A1 were measured at frequent intervals during inpatient or outpatient periods. Mean plasma glucose decreased significantly in all inhospital patients and remained significantly less than before pump therapy in two of three as outpatients during the 8--12 wk of follow-ups; however, complete normalization of glucose metabolism was not accomplished in any. All three demonstrated a progressive decline in hemoglobin A1 levels to normal or near-normal values. The need for long-term studies of open loop infusion systems in a research setting before their adaptation to routine care is emphasized.

Adolescent↗
PubMedDate not supplied

Efficacy of low-dose insulin therapy for severely obtunded patients in diabetic ketoacidosis.

To evaluate the efficacy of low-dose insulin therapy in cases of severe diabetic ketoacidosis (DKA), we examined admission clinical and biochemical parameters and responses to therapy in 48 diabetic patients who presented with DKA and were randomized to receive either high- or low-dose insulin. There were no differences in the initial clinical and biochemical parameters of the patients, regardless of assignment to low or high dose; however, a subgroup of 13 patients who were classified as severe DKA (based on their presentation in a comatose or stuporous state) had, as expected, more marked clinical and biochemical abnormalities than their alert cohorts. The responses to therapy (rate of glucose decrement and control of acidosis) were comparable in the high-dose and low-dose groups of comatose/stuporous patients and were not significantly different from the noncomatose cohorts. These data indicate that low-dose insulin therapy in severely ill comatose patients is as effective as high-dose.

Adult↗
PubMedDate not supplied

Maturity-onset diabetes of the young: an illustrative case for control of diabetes and hormonal normalization with dietary management.

The efficacy of diet therapy used for one patient with the newly classified maturity-onset diabetes of the young (MODY) is reported. Using the conventional American Diabetes Association's food exchange system with appropriate caloric restriction, the patient's weight was reduced from 25% to 6% above ideal body weight in the 14-wk study. Results of three meal tolerance tests compared with a group of lean, normal subjects revealed a steady improvement from baseline and postprandial hyperglycemia, with concomitant normalization of the counterregulatory hormones as well as hemoglobin A1, free fatty acids, and subsequent euglycemia. This case demonstrates the effectiveness of dietary manipulation as the major therapy in MODY with obesity.

Adult↗