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Biomedical subjects

B Vialettes

Publications and source records attributed to B Vialettes.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Evaluation of the acceptability of 2 methods for self monitoring of blood sugar by a group of insulin-dependent diabetic patients].

In order to evaluate the advantages and disadvantages of two methods of blood glucose self-monitoring (either direct semi-quantitative reading on Haemoglukotest 20-800 or quantitative reading of Dextrostix strips using a reflectance-meter, Glucometer) 20 insulin-dependent diabetics selected according to the quality of the management of their own diabetes were asked to try both methods for 3 months and then fill a questionnaire assessing their acceptance. Analysis of the responses shows that home blood glucose monitoring is well accepted even after one year by patients aware of the necessity of a good glycemic control. It is specially useful for the adaptation of insulin doses and less so for identification of hypoglycemic attacks. Haemoglukotest 20-800 is appreciated for its easy utilization specially during professional life and outside leisure. However, the reflectance-meter Glucometer is preferred by most patients because they feel it is more reliable and safe.

Adolescent↗
PubMed1983

Clinical features of diabetogenic and atherogenic obesity.

Fat mass per se has little effect on the progression of obesity towards diabetes. Predominance of fat in the upper part of the body resulting in android obesity is at least the clinical reflection of factors which lead obesity to progress towards diabetes and atherosclerosis. Therefore, this type of obesity may be termed diabetogenic and atherogenic obesity. Insulin and cortisol secretion in obesity are not correlated with body fat but with the predominance of fat in the upper part of the body. Diabetogenic obesity may evolve through 5 stages from initial obesity without diabetes to insulin dependent diabetes in previously obese subjects. Aside from the characteristics of body fat distribution, the mechanisms which induce or interrupt this progression remain unknown.

Adolescent↗
PubMed1983

Assessment of viral and immune factors in EMC virus-induced diabetes: effects of cyclosporin A and interferon.

EMC virus-induced diabetes in mice may be a model of human type I diabetes. It is postulated that auto-immune reaction plays a role in beta cell destruction after viral aggression. The use of anti-viral (interferon) or immunosuppressive drugs (Cyclosporin A) could contribute to an understanding of the pathogenesis of diabetes in this model. Early or late administration of cyclosporin A increased mortality and frequency of diabetes in female mice and did not influence these parameters in males despite a reduction of pancreatic inflammatory lesions. Interferon administered at the time of virus inoculation diminished mortality in both sexes and frequency of diabetes in males. These results are against an autoimmune pathogenesis for diabetes in this model and suggest that the virus plays the major role in beta cell damage.

Animals↗
PubMed1983

Overnight basal insulin requirements in insulin dependent diabetics.

Programming open loop insulin delivery systems makes necessary the knowledge of patients insulin needs. It is frequently postulated that insulin needs increase at the end of the night in relation to the rise in cortisol secretion. According to this hypothesis is it justified to speed up the insulin infusion rate in the early morning? This question was addressed by studying insulin infusion rate by an artificial pancreas during the night in 12 C. peptide negative insulin dependent diabetics. They were connected to the artificial pancreas from 8 a.m. to 10 a.m. the next morning while on their habitual diabetic diet and slept as usual from 11 p.m. to 7 a.m. approximately. From 11 p.m. to 7 a.m. mean insulin infusion rate was 21.5 +/- 3.3 mU/Kg/h representing 15.6 +/- 1.6% of the dose delivered in 24 hours. Blood glucose was stable around 85 mg/dl. No significant differences were observed in the hourly insulin infusion rate during the night period, in spite of a slight tendency to a rise (from 21.1 +/- 2.8 to 22.1 +/- 2.6 mU/kg/h) tendency to a rise (from 21.1 +/- 2.8 to 22.1 +/- 2.6 mU/kg/h) after 4 a.m. On the basis of these results obtained in patients sleeping as usual it does not appear useful to envisage a systematic acceleration of insulin infusion rate by continuous delivery systems in the early morning.

Adult↗
PubMed1983

[Decrease in the serum level of the C3 complement component in noninsulin dependent diabetes of recent onset].

Complement components C3, C4 and C3A were measured by immuno-diffusion in plasma of 36 recent onset insulin-dependent diabetics (IDD) and compared to plasma complement levels of 19 long-standing IDD and 18 non diabetic controls. A significant decrease of C3 and a mild increase of C3A was found in recent-onset diabetes group. However these variations could not be correlated with IgG-islet cell antibodies, C3--fixing islet cell antibodies or A--B HLA antigens. No significant difference was found between long-standing IDD and controls for the 3 complement components. In conclusion, the decrease of C3, found in 30% of recent onset IDD, might be due to increase complement consumption either by the insulitis process or by circulating immune complexes.

Adolescent↗
PubMed1982

[The artificial pancreas in surgery. An attempt to simplify intra- and post-operative insulin therapy].

The insulin requirements of 10 insulin-dependent diabetic patients were evaluated during and after surgery (including 4 caesarian sections) by connecting the patients with an artificial pancreas. Considerable variations were observed in the intra-operative period. In contrast, the amounts of insulin released during the immediate post-operative period were more regular and reproducible (mean: 2.36 U/h for a glucose intake of 200-250 g/24 h). A satisfactory control of glycaemia was obtained with this dosage in 7 insulin-dependent post-operative patients without using an artificial pancreas. It would therefore seem that in most cases continuous insulin infusion combined with direct measurement of capillary glycaemia could replace an artificial pancreas and make the intra- and post-operative care of diabetic patients simpler and more effective.

Adult↗
PubMed1982

Abnormalities of erythrocyte deformability and platelet aggregation in insulin-dependent diabetics corrected by insulin in vivo and in vitro.

Erythrocyte deformability is lower than normal in uncontrolled insulin-dependent diabetics and returns towards normal after 24 h treatment with a feedback-controlled insulin infusion. Deformability of normal erythrocytes is reduced by incubation in plasma from uncontrolled insulin-dependent diabetics but is normal in plasma from insulin-dependent diabetics controlled by 24 h insulin infusion, or in plasma from uncontrolled insulin-dependent diabetics with insulin added in vitro. Therefore, insulin has a direct action on erythrocyte deformability. Platelet aggregation measured in whole blood is raised in uncontrolled insulin-dependent diabetics and returns to normal after 24 h treatment with a feedback-controlled insulin infusion. Aggregation of normal platelets rises in the presence of erythrocytes from uncontrolled insulin-dependent diabetics, but not erythrocytes from the same patients after 24 h treatment with insulin. The effect of insulin on platelet aggregation therefore seems to be at least partly mediated by erythrocytes. The enhanced platelet aggregation seen in uncontrolled insulin-dependent diabetics can be explained either by a direct effect of erythrocyte rigidity or by an increased release of nucleotides (ADP) by the erythrocytes.

Diabetes Mellitus↗
PubMed1982

Kinetics of fast haemoglobin in diabetic rats.

This study was designed to examine the appearance and disappearance kinetics of glycosylated haemoglobin during abrupt changes of blood glucose in the rat. The concentration of the fast haemoglobin component, which has similar chromatographic and electrophoretic profiles to human haemoglobin A1, was measured after the induction of diabetes by streptozotocin and its cure by syngeneic intraportal islet transplantation. Fast haemoglobin was increased in 12 diabetic rats compared with 22 controls (15.8 +/- 0.8 versus 8.2 +/- 0.3%, mean +/- SEM). In a group with mild diabetes (n = 8, blood glucose less than 22 mmol/l), fast haemoglobin rose to 13.7 +/- 1.0% by week 8. In a group with severe diabetes (n = 4, blood glucose greater than 22 mmol/l), fast haemoglobin rose more quickly (in 3 weeks) to a higher level (18.2 +/- 3.3%) and changed little thereafter. This suggests a saturable system in which the rate of increase and final value depend upon the degree of hyperglycaemia. After islet transplantation, fast haemoglobin returned to normal in 4 weeks (n = 5, 17.6 +/- 1.4 to 9.4 +/- 0.9%). This delay is shorter than expected from the red cell lifespan (around 60 days), suggesting that haemoglobin glycosylation may be partly reversible. These results suggest that in unstable diabetes the interpretation of haemoglobin A1 levels is not as simple as was supposed previously.

Animals↗
PubMed1982

[Effects of strict control of blood sugar by an artificial pancreas on nerve conduction velocity in diabetics].

This study concerned 13 patients with diabetes mellitus who, although under insulin therapy treatment, had poor control of their diabetes. Motor conduction velocity (MCV) in the peroneal, ulnar and median nerves, sensory conduction velocity (SVC) of the median nerve and sensory potential amplitude (SPA) of the median nerve were determined immediately before and after 24 h of strict control of blood glucose by an artificial pancreas. A significant increase in the MCV of the ulnar nerve (P less than 0.01) and in the SCV of the median nerve (P less than 0.05) was found. This acute improvement led us to presume that repair of anatomic lesions would be extremely unlikely. Only a metabolic disturbance due to hyperglycemia can be rapidly corrected. This metabolite alteration may be held partly responsible for the slowing of nerve conduction in diabetes. No significant difference was noted in the MCV of the peroneal nerve and of the median nerve and the SPA of the median nerve. This suggests that advanced degenerative lesions are present in these nerves particularly in the lower limbs. Such lesions cannot be rapidly reversed by metabolic control.

Adolescent↗
PubMed1982

[Auto-immunity and insulin-dependent diabetes].

Many observations suggest that auto-immune process are activated during the beta-cell destruction in insulin-dependent diabetes (IDD): they include association with organ specific auto-immune disease, frequency of circulating anti-organ antibodies, circulating anti-islet cell antibodies, insulitis-like lesions in the pancreas and in vitro lymphocytic reaction against pancreatic antigens. However, it is still uncertain if these reactions are actually involved in the beta cell destruction. Cytotoxicity experiments on beta cells in culture and animal models support this hypothesis. Nosologic classification which categorizes an autoimmune type of IDD, a viral type of IDD and a large proportion termed idiopathic IDD may be a useful device to further our understanding of the pathogenic pathways but may be open to criticism of undue simplification as in this presumably multifactorial disease, the differences between affected individuals may be quantitative and not qualitative.

Animals↗
PubMed1981

[Plasma lipid fractions in insulin-dependent diabetic patients. Effects of short-term control of glycaemia (author's transl)].

In order to elicitate a possible influence of short-term control of glycaemia on circulating plasma lipid fractions, the authors have endeavoured to find out: (a) whether there was a correlation between these fractions and glycosyl-haemoglobin (Hb A1) which indicates previous glycaemic balance, and (b) whether the various lipid fractions were modified by absolute control of glycaemia during a 24-hour application of artificial pancreas. They found that HbA1 correlated positively with total cholesterol and VLDL + LDL cholesterol, but not with HDL cholesterol. After 24 hours on artificial pancreas there was a significant decrease in total blood cholesterol without changes in blood triglycerides. The decrease was homogenous and concerned cholesterol concentrations in both low and high density lipoproteins. The authors conclude that the increased risk of atherosclerosis in insulin-dependent patients is in-related to a decrease in HDL cholesterol.

Adult↗
PubMed1981

Effects of insulin on erythrocyte deformability in diabetics--relationship between erythrocyte deformability and platelet aggregation.

Erythrocyte deformability was studied by the filtration technique of Reid & Dormandy using whole blood and washed erythrocytes from insulin-dependent diabetics (IDD) under insulin delivery by an artificial pancreas (AP). The same technique was employed to study deformability in vitro using normal erythrocytes incubated in the presence of insulin. Results of this study show that in IDD the initially poor erythrocyte deformability is improved within hours of insulin administration. Improved deformability was accompanied by increased levels of intra-erythrocyte ATP but without changes in levels of HbG and 23 DPG. Incubation of erythrocytes in medium containing glucose showed that deformability was significantly improved in the presence of insulin. These results indicate that insulin favourably affects erythrocyte deformability in IDD. Before and after 24 hours treatment by AP, platelet aggregation was studied in IDD by the technique of Born using platelet-rich plasma (PRP) and by a modified Breddin technique using PRP, whole blood or whole blood treated by chlorpromazine and mixtures of erythrocytes from IDD with normal PRP. Platelet hyperaggregation was only found in the presence of erythrocytes from untreated diabetics. Chlorpromazine, at a dose (10 mumole) which inhibits haemolysis without inducing platelet hyperaggregation, eliminated the above anomaly. In conclusion, it is conceivable that the insulin-induced correction of poor erythrocyte deformability eliminates excessive fragility of erythrocytes and their haemolysis wit release of ADP, thus avoiding platelet hyperaggregation.

2,3-Diphosphoglycerate↗
PubMed1980

Low plasma levels of pancreatic polypeptide in obesity.

Plasma levels of pancreatic polypeptide (PP) were studied in a group of 22 normal and 22 obese subjects after an overnight fast. In a second group of 10 normal and 13 obese adults, PP secretion was stimulated by a protein-rich meal. The results indicate lower fasting PP values in the obese subjects and a decreased response during the second phase of the meal-induced secretion. This could suggest a possible role of PP in obesity.

Adult↗
PubMed1980

[The clinical value of C-peptide assay (author's transl)].

The C-peptide is a polypeptide generated from enzymatic cleavage of proinsulin into insulin in pancreatic B. cell. C-peptide and insulin are secreted in an equimolar ratio. For this reason. C-peptide radio-immunoassay in blood or urine reflects the insulin secretion when direct insulin determination cannot be done (insulin treatment, circulating insulin antibodies). This assay is mainly used in clinical and investigational studies of insulin dependent diabets. It enabled demonstation of residual secretion of insulin in numerous insulin dependent patients (70% during the first year and 15% after the 15th year of the disease). Persistence of insulin secretion may play a role in the natural history of diabetes since patients with detectable C-peptide immunoreactivity have more stable diabetes, are controlled by lower insulin dose and are less ketosis prone than the others. Factors which influence persistence of B. cell activity in some IDD remain unknown.

C-Peptide↗