Kinetics and metabolic activity of biosynthetic NPH insulin evaluated by the glucose clamp technique.

The glucose clamp technique has been used to evaluate the metabolic activity of NPH biosynthetic insulin in diabetic subjects free from anti-insulin antibodies. After overnight blood glucose normalization with a glucose-controlled insulin infusion system (Biostator), an s.c. injection of NPH insulin was given in the abdominal region. The insulin dose (0.236 +/- 0.05 U/kg body wt) was related to the usual intermediate-acting insulin requirement in the morning. Glucose was clamped at 100 mg/dl by a feedback i.v. glucose infusion. The end of the action of s.c. injected insulin considered conventionally to be the time of the spontaneous rise of blood glucose to 110 mg/dl. Free insulin levels were higher and the length of action was longer after NPH porcine than after NPH biosynthetic human insulin (BHI) (area under the free insulin curve: porcine 1423 +/- 556 mU/L/h; BHI 1045 +/- 338 mU/L/h, P less than 0.05; length of action: porcine 16.0 +/- 3.2 h; BHI 13.7 +/- 0.9 h, P less than 0.05); the glucose requirement was higher after porcine (76.8 +/- 13.5 g) than after BHI (58.5 +/- 14.6 g) without reaching statistical significance. However, the metabolic activity of the bioavailable insulin (index of plasma free insulin activity) was similar for the two insulins (porcine 381 +/- 77.4, BHI 342.8 +/- 54.2 mU/L/g of glucose/h). We conclude that a difference in pharmacokinetics exists between NPH BHI and porcine NPH insulin, which makes the latter metabolically more active. The different behavior does not seem to be related to the insulin molecule itself but could be a consequence of the unequal content of protamine in the two pharmacologic preparations.

Continuous subcutaneous insulin infusion treatment in insulin-dependent diabetic patients: a comparison with conventional optimized treatment in a long-term study.

The effects of continuous subcutaneous insulin infusion (CSII) by portable pump (Microjet MC2, Miles) and conventional optimized insulin therapy (OCT) on metabolic control were compared in a group of five insulin-dependent diabetic patients. A group of seven normal volunteers was examined as control. CSII treatment consisted of a basal insulin infusion and three boluses of 60 min, starting 30 min before each main meal. OCT was characterized by three daily s.c. insulin injections: regular insulin before breakfast and lunch, regular plus lente before dinner. Two protocols of study were performed. In the first one the metabolic (blood glucose, NEFA, 3-beta-OH-butyrate) and hormonal (free insulin, pancreatic glucagon, cortisol, growth hormone) profiles were examined in the hospital with the patients connected to a "blood glucose monitor," after 45 days of OCT and CSII treatment, respectively. In the course of CSII treatment, a better blood glucose profile was observed than during OCT (OCT: MBG = 162 +/- 18 mg/dl, M = 43 +/- 11, MAGE = 151 +/- 26 mg/dl. CSII: MBG = 133 +/- 8 mg/dl, M = 29 +/- 5, MAGE = 138 +/- 19 mg/dl: P less than 0.05), although the indices remained higher than in normal subjects (MBG = 85 +/- 3 mg/dl, M = 0.98 +/- 0.18, MAGE = 49 +/- 3.6 mg/dl). CSII treatment was also associated with an improvement of NEFA and 3-beta-OH-butyrate profiles. Plasma "free" insulin (IRI) ranged between 18.2 +/- 5.4 and 32 +/- 5.5 microU/ml during CSII. Plasma glucagon (IRG) concentration after overnight fast was 195 +/- 65 pg/ml and 220 +/- 55 pg/ml during OCT and CSII treatment, respectively, with minor changes throughout the day. (ABSTRACT TRUNCATED AT 250 WORDS)

Activity of an alcohol-based hand gel against human adeno-, rhino-, and rotaviruses using the fingerpad method.

OBJECTIVE: To assess the activity against three non-enveloped viruses (an adeno-, a rhino- and a rotavirus) of a gel containing 60% ethanol, using experimentally contaminated thumb- and fingerpads of 12 panelists, as per standard procedure E-1838-96 of the American Society of Testing and Materials. DESIGN: Each digit received 10 microL of the test virus suspension. The inoculum from the thumbs was eluted immediately with 990 microL of Earle's balanced salt solution (EBSS) to assess the amount of virus on each digit (0-minute control). The inoculum on the fingers was allowed to dry (20-25 minutes), and virus was eluted from two fingerpads to determine the loss in virus infectivity upon drying (baseline titer). Then the dried inoculum on randomly selected fingers was exposed to 1 mL of the test product or standard hard water (200-ppm calcium carbonate) for 20 seconds. The virus remaining was eluted with 1 mL of EBSS, titrated to determine the amounts eliminated, and compared to the baseline titer. RESULTS: Each digit received at least 10(4) plaque-forming units of virus in 10 microL. The amounts of adeno-, rhino-, and rotaviruses surviving the drying were 30%, 75%, and 42%, respectively. The product reduced the infectivity titers of the three viruses by 3 to >4 log10 when compared to a reduction of < or =1 log10 for the hard-water rinse. CONCLUSION: The level of virus reduction by gel was statistically significantly higher than that seen with the water control. Evidence for such activity against non-enveloped viruses supports further investigation of the benefits of this product.

[Use of the endocrine artificial pancreas (GCIIS; Biostator) in heart surgery]. / Applicazione del pancreas artificiale endocrino (GCIIS; Biostator) nella cardiochirurgia.

It is well known that deep hypothermia used in open-heart surgery is usually associated with a marked reduction in carbohydrate tolerance, especially dangerous in the diabetic patient, since it might result in severe metabolic complications, namely ketosis and hyperosmolar coma. In order to prevent the occurrence of such complications we treated an insulin-dependent diabetic patient undergoing cardiovascular surgery, with a feed-back insulin infusion operated by an artificial pancreas (GCIIS, Biostator). The Biostator was then used to perform a continuous (minute by minute) blood glucose monitoring in 2 more patients, a type II (non insulin-dependent) diabetic and a non diabetic. Blood samples were drawn sequentially in order to determine plasma free insulin concentration. The glycemic profile observed in the insulin-dependent diabetic under artificial pancreas treatment was similar to that in the non-diabetic. Plasma free insulin levels dropped near to zero during by-pass cooling, returning toward basal level during the rewarming phase. Such results are then discussed by the Authors and given a pathogenetic interpretation.

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.

Metabolic effects of intensified insulin therapy.

Intensified insulin therapy is usually carried out either with multiple subcutaneous insulin injections (ICT: intensified conventional therapy) or with continuous subcutaneous insulin infusion (CSII) by minipumps. For two years we have been studying two matched groups of type I diabetic patients, treated with 3 daily insulin injections (ICT) and with CSII ( Microjet , Miles), respectively. Blood glucose control, as assessed by integrated mean blood glucose (MBG), was similar in both groups, but a better metabolic stability ('M' index of Schlichtkrull ) was evident in the CSII group. From the 24-hour profiles of plasma 'free' IRI and metabolites (glucose, beta-OH-butyrate, lactate, pyruvate, alanine), both the hepatic and peripheral underinsulinization and related metabolic alterations were still evident in both groups of patients. The number of hypoglycaemic episodes, recorded by home blood glucose monitoring, was similar in both groups of patients, while the perception of symptomatic hypoglycaemia seemed to be reduced in the patients treated with CSII.

Improvement of artificial endocrine pancreas (Biostator; GCIIS) performance combining feedback controlled insulin administration with a pre-programmed insulin infusion.

It is well known that the glycemic control accomplished by the artificial endocrine pancreas (Biostator; GCIIS), requires an excessive insulin consumption. In order to improve the Biostator performance, we have studied 5 insulin dependent diabetic patients on anticipated automatic pre-programmed insulin infusion starting at the beginning of breakfast. Such an operating method allowed us to obtain a significant reduction in insulin requirements (from 17,3 +/- 2,2 U to 13,3 +/- 2,2 U), and a better glycemic control (MBG 98,7 +/- 5,4 vs 111,1 +/- 5,6; M 2,34 +/- 0,9 vs 6,96 +/- 1,7; delta G 43,8 +/- 3 vs 73,4 +/- 9,7), as compared to those observed under conventional feed-back control in relation to breakfast.

Clinical trial with porcine des-Phe B1 insulin. A comparative study with unmodified insulin on therapeutical efficacy, biological activity and immunogenicity.

Studies have been carried out in insulin-dependent diabetics of porcine Des-pheB1 insulin, which is an insulin analogue obtained by removal of the N-terminal aminoacid of the B chain. The therapeutic activity of Des-phe insulin (regular and semilinte preparations) was tested in a group of 24 insulin-dependent diabetics and compared with the unmodified parent compound. Both types of insulin, Des-phe and unmodified were chromatographically purified preparations. The mean daily blood glucose profile obtained with Des-phe insulin was slightly higher than that of unmodified preparations, while the mean blood glucose and the "M" index of Schlichtkrull were similar. The biological activity of regular Des-phe and its unmodified parent compound was evaluated in 6 further insulin-dependent diabetics, with the aid of an artificial endocrine pancreas. The insulin requirement to achieve an optimal metabolic control was 10% less with Des-phe insulin than with the unmodified preparation. The immunogenicity of Des-phe and unmodified insulins, tested by measuring plasma insulin antibody titres in diabetic patients either newly or already insulin treated, was comparable. However the binding capacity of 125I-Des-phe insulin to preexisting antibodies seemed to be less than that of unmodified 125I-insulin in patients previously treated with unmodified insulin. Finally Des-phe appeared able to correct promptly and completely the insulin-induced lipodystrophy of three insulin-dependent diabetics.

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.

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.

Clustering of albumin excretion rate abnormalities in Caucasian patients with NIDDM. The Italian NIDDM Nephropathy Study Group.

Proteinuria and nephropathy have been found to cluster in families of non-insulin-dependent diabetic (NIDDM) Pima Indian, and in Caucasian insulin-dependent diabetic (IDDM) patients. No information is at present available for Caucasian NIDDM patients. The aim of the present study was to determine whether micro-macroalbuminuria (AER+) is associated with albumin excretion rate abnormalities in diabetic and non-diabetic siblings of probands with NIDDM and AER+. We identified 169 Caucasian families with one NIDDM proband (the patient with longest known NIDDM duration) (101 families with only NIDDM siblings, 33 families with both NIDDM and non-NIDDM siblings and 35 families with only non-NIDDM siblings). Of the probands 56 had AER+ [Prob-NIDDM-(AER+)], 78 had AER-[Prob-NIDDM-(AER-)], 74 siblings of Prob-NIDDM-(AER+), and 113 siblings of Prob-NIDDM-(AER-) also had NIDDM. Data on albuminuria and retinopathy from multiple sibling pairs when the size of the sibship was more than two was adjusted according to a weighting factor. The odds ratio for AER+, in siblings of Prob-NIDDM-(AER+) adjusted for age, hypertension, glycated haemoglobin A1c and other confounding variables was 3.94 (95% confidence intervals: 1.93-9.01) as compared to siblings of Prob-NIDDM-(AER-). The 74 siblings of Prob-NIDDM-(AER+) had higher prevalence of proliferative retinopathy than siblings of Prob-NIDDM-(AER-) (14 vs 2%; p < 0.01). We also identified 66 non-diabetic siblings of 41 NIDDM probands with AER+ and 36 non-diabetic siblings of 27 NIDDM probands with AER-. Albumin excretion was two times higher, although still within the normal range, in the non-diabetic siblings of Prob-NIDDM-(AER+) than in siblings of Prob-NIDDM-(AER-) [median = 13.5 (range 0.5-148) vs 6.6 (range 1-17) micrograms/min (p < 0.05)]. In conclusion higher rates of albumin excretion aggregate in Caucasian families with NIDDM. Proliferative retinopathy is more frequently observed in families showing a clustering of AER+ and NIDDM. These findings suggest that familial factors play a role in the pathogenesis of renal and retinal complications in NIDDM.