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Biomedical subjects

M Massi-Benedetti

Publications and source records attributed to M Massi-Benedetti.

32 records · Page 2Linked to original sources
PubMed1980

Modification of glycosylated haemoglobin concentration during artificial endocrine pancreas treatment of diabetics. Evidence for a short-term effect on HbA 1 (a+b+c) levels.

In order to verify whether or not insulin-induced blood glucose control can acutely lower glycosylated haemoglobin levels, HbAI (a+b+c) (HbAI) was measured in 11 diabetics before, during and after 3 days of treatment with an "artificial endocrine pancreas" (Biostator). Initially 5 patients were in fair glycaemic control (group A), while the other 6 showed poor control (group B). HbAI levels decreased significantly after 3 days in both groups A (from 9.6 +/- 0.2% to 8.5 +/- 0.3%, mean +/- SEM, p less than 0.05) and B (from 13.7 +/- 0.2% to 12.6 +/- 0.3%, p less than 0.05). A further HbAI decrease was observed until day 60 following Biostator treatment, during which period glycaemic control improved, as assessed by fasting and post-lunch plasma glucose values and daily glycosuria determined every 10 days. These results suggest that increased HbAI levels may be reversed early by strict blood glucose control during a 3 day period. It is concluded that HbAI levels not only reflect long-term glycaemic control, but also recent acute variations in mean blood glucose values.

Adolescent↗
PubMed1979

[Adrenergic activity and glycometabolic compensation in patients with diabetes mellitus].

In an assessment of the degree of adrenergic activity in the course of diabetes mellitus, plasma levels and urinary excretion of norepinephrine and epinephrine were determined in 20 normal subjects and 47 diabetics: 11 in good control (group I), 23 in poor control (group II), 13 with frank ketoacidosis (group III). The study was repeated in groups II and III once good glycometabolic control had been achieved. Slightly above normal catecholamine levels were noted in group I, while there was a marked increase in group II. Group III shaved an enormous increase by comparison with the other two groups. After medical treatment values in group III fell to within the group I range. The conclusion is drawn that a close relationship exists between adrenergic acitivity and the degree of control of diabetes. The sympathetic nervous system, therefore, interferes in the course of diabetes with blood sugar control via numerous, complex mechanisms.

Adolescent↗
PubMed1979

Artificial beta-cell application in two cases of insulinoma: a different pattern in beta-cell adenoma and carcinoma.

With the aid of an artificial beta-cell (Biostator, Miles Laboratories Inc.), a different metabolic and biological pattern of behaviour was observed in benign versus malignant insulinoma. In the patient with beta-cell adenoma but not in the one with carcinoma, plasma insulin concentrations decreased promptly and markedly, and blood glucose increased during diazoxide and somatostatin infusion. Moreover, only in the adenoma patient was glucose need characterized by a circadian rhythm with the maximum values during daytime. This behavior could reflect the degree of tumor beta-cell differentiation. The controlled glucose and insulin infusion was of great help during and after surgical treatment.

Adenoma↗
PubMed1979

Therapeutical application of artificial beta-cell in surgery and obstetrics.

An artificial beta-cell (Biostator) was used to control blood glucose concentration in six insulin-dependent diabetics who underwent surgical procedures and in five diabetic women during both vaginal childbirth and Caesarian section. In all cases, an optimal glycometabolic control was achieved before, during, and after surgery and delivery.

Adult↗
PubMed1979

Variation induced by a three-days application of the artificial beta-cell on glucagon, growth hormone and catecholamine secretion, glycosylated hemoglobin, and erythrocyte 2,3-diphosphoglycerate concentration.

Five insulin-dependent diabetics with poor metabolic control were examined at the beginning and after a three-day application of artificial endocrine pancreas (AEP). Pancreatic alpha cell function evaluated by arginine infusion (0.5 g/Kg b.w. over 30 minutes) showed no significant differences between the beginning and during artificial beta cell aplication, but the increment in plasma glucagon level over basal values observed in both tests appeared significantly higher at 30 and 60 min in comparison with a control group. Growth hormone response to arginine infusion was clearly reduced in the second test. C-peptide concentration appeared very low in basal conditions and during arginine infusion; no improvement was observed after three days of AEP application. Urinary excretion of norepinephrine markedly increased at the beginning of the study, reversed almost to normal during AEP treatment, while minor changes were observed in urinary excretion of epinephrine. The Concentration of glycosylated hemoglobin, markedly higher than normally before the connection with AEP, showed a slight but significant decrease during glucose-controlled insulin infusion. Finally, 2,3-diphosphoglycerate was normal and no modifications were observed in the course of the study.

Arginine↗
PubMedDate not supplied

Red cell 2,3-DPG levels in diabetic vasculopathy.

RBC 2,3-DPG resulted statistically increased versus normal subjects in 22 insulin-dependent diabetics affected by arterial vasculopathy and in 19 vasculopathic non-diabetic patients. RBC 2,3-DPG, on the other hand, did not differ from the normal mean in 16 insulin-dependent diabetics without vascular involvement. The increase of RBC 2,3-DPG represents principally a consequence of the vasculopathy.

Diabetes Mellitus, Type 1↗
PubMedDate not supplied

Glucagon and carbohydrate disorder in a totally pancreatectomized man (a study with the aid of an artificial endocrine pancreas).

The effect of insulin withdrawal and exogenous glucagon infusion upon blood glucose concentration was investigated in a totally pancreatectomized patient with the aid of an artificial endocrine pancreas. Blood glucose remained unchanged at about 100 mg/100 ml, when insulin infusion was stopped, but rose up to 300 mg/100 ml, during a 12-h period of exogenous glucagon infusion at a rate of 3 ng/kg/min. Fractionation of whole plasma on Bio Gel P-30 revealed no immunoreactive glucagon in the region of true glucagon. This study seems to reinforce the hypothesis that true glucagon is essential in the fasting condition at least in the short term to produce hyperglycemia in insulin deprived diabetics.

Aged↗
PubMedDate not supplied

A comparative study of the activity of biosynthetic human insulin and pork insulin using the glucose clamp technique in normal subjects.

The activity of biosynthetic human insulin (BHI) has been compared with that of pork insulin using the glucose clamp technique in normal subjects. After a baseline period, insulin was infused at 0.02 U/kg/h for 2 h, then 0.032 U/kg/h for 2 h, and finally 0.05 U/kg/h for 2 h. Glucose was clamped at baseline values using a glucose-controlled insulin infusion system (Biostator) and the amount of glucose infused to maintain normoglycemia calculated for each insulin dose for the two insulins. C-peptide levels decreased with both insulins, suggesting suppression of endogenous insulin secretion. Serum insulin levels attained were the same for both insulins. There were no significant differences in either total glucose infused or glucose infused during the last 30 or 60 min at each insulin dose for the two insulins. Intermediary metabolite responses to the infusion of the two insulins were similar. We conclude that in normal human beings, BHI shows identical metabolic activity with pork insulin.

Adult↗
PubMedDate not supplied

Comparison of the activity and pharmacokinetics of porcine insulin and human insulin (Novo) as assessed by the glucose clamp technique in normal and diabetic man.

Using the glucose clamp technique, human insulin (Novo) and natural porcine insulin were found to have identical potency in terms of glucose delivery in the second hour of i.v. infusion at low (0.02 U/kg/h; 265 +/- 25 versus 232 +/- 35 mg/min, respectively) and high (0.05 U/kg/h; 467 +/- 47 versus 452 +/- 41 mg/min, respectively) doses in normal man. Insulin metabolic clearance rates, serum in vivo half-life, and rate of onset of action were also similar. In insulin-dependent diabetic subjects, whose blood glucose levels were also held constant by feedback glucose infusion, the free insulin profiles after s.c. injection of neutral soluble human insulin and porcine insulin (0.2 U/kg) were identical, and similar to those after conventional and highly purified bovine insulin preparations. Glucose requirement to maintain normoglycemia for the first 5 h after injection was 49.6 +/- 8.2 g for conventional bovine insulin, 50.4 +/- 10.0 g for highly purified bovine, 40.5 +/- 6.9 g for human insulin, and 50.6 +/- 12.4 g for porcine insulin (NS by analysis of variance). No difference in insulin activity was detected when glucose requirement was expressed in terms of the prevailing free insulin concentration. Responses of blood intermediary metabolite levels were indistinguishable between all insulins in both studies.

Adult↗