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Biomedical subjects

D Michaelis

Publications and source records attributed to D Michaelis.

At least 91 records · Page 5Linked to original sources
PubMed1984

Cellular immune reactions against rat pancreatic islets mediated by antibodies from type I diabetic patients.

Serum samples from 13 newly diagnosed type I diabetics were tested for their ability to mediate antibody-dependent cellular immune reactions against pancreatic islets prepared from Wistar/Jena K rats. Nine of these serum samples proved able to mediate islet cell damage when the islets were preincubated with sera and then cultivated with leukocytes of healthy subjects for 20 h. Damage to islets was demonstrated both by the trypan-blue exclusion test and by measurement of insulin leakage during incubation. The data presented point to a possible pathogenetic role of antibodies mediating cellular immune reactions in type I diabetes.

Adolescent↗
PubMed1984

Islet cell cytoplasmic and surface antibodies' prevalence and beta cell specificity of islet cell surface antibodies in some subjects with putative islet cell autoimmunity.

In human sera two methods of islet cell cytoplasmic antibody (ICA) detection (on Bouin-fixed or cryostate sections of human pancreas) and the islet cell surface antibody (ICSA) method on isolated rat islet cells were compared. The ICA detection on Bouin-fixed sections was more sensitive than that on cryostate sections. In two groups of subjects with putative islet cell autoimmunity ICA prevalence was higher than ICSA prevalence. However, a weak correlation between both types of antibodies was established. In one group of healthy subjects with cytotoxic serum against rat beta cells a high prevalence of ICSA was found, whereas none of them had ICA. Defined on the basis of a positive immunofluorescence on rat islet cells, ICSA positive sera of newly diagnosed IDDM patients reacted to a significantly higher percentage with beta cells than did normal controls. In conclusion, of all methods compared ICA detection on Bouin-fixed pancreas sections seems to be the most suitable method for the detection of an islet cell autoimmunity.

Acetates↗
PubMed1982

[Results of a multicentric study on long term diabetes in the East German population].

In the diabetes population of the GDR by means of the dispensary network of the consulting points 159 diabetics with a duration of the disease of at least 40 years were recognized and investigated on the basis of a standardized documentation material. 23 diabetics had survived their disease for longer than 50 years. The number of benign long-term courses in males was absolutely and relatively higher. The following frequencies of normal findings were stated: 55 per cent good general condition, 78 per cent normal weight/or underweight, 33 per cent no retinopathy, 65 per cent no proteinuria, 49 per cent normal ECG in rest. A proliferating retinopathy was found in 10 per cent, creatinine increases in 10 per cent, coronary infarctions in 32 per cent, gangrene and amputations, respectively, in 9 per cent. There was no striking longevity of the parents. In the majority of cases disciplined patients with a well-balanced metabolic condition were concerned. The partly existing atherogenic factors of risk (hypertension, smoking habits) speak for complex causes of the favourable course, including vasoprotective factors up to now not yet clarified.

Adult↗
PubMed1982

Insulin antibodies in juvenile diabetes mellitus. Correlations to diabetic stability, insulin requirement and duration of insulin treatment.

We investigated the plasma insulin binding patterns of 15 insulin-treated juvenile diabetics with a very low residual B-cell function. Determination of the insulin binding was performed after removal of therapeutic insulin. 125I-monoiodoinsulin was used and insulin binding was measured over a large range of insulin concentration. Insulin binding parameters were evaluated by Scatchard analysis of the binding data. Significantly elevated insulin binding was detected when the diabetic control was stable. These patients had a lower insulin requirement and low equilibrium dissociation constants of the high affinity antibodies. Furthermore, a strong negative correlation between the duration of insulin treatment and insulin binding could be demonstrated resulting from both decreasing antibody affinities and maximum binding capacities. We discuss the stabilizing effect of insulin antibodies on the metabolic character assuming that dissociating insulin-antibody complexes mimic a "basal insulin secretion" similar to pancreatic B-cells with residual functional capacity.

Adolescent↗
PubMed1980

[Spontaneous changes in carbohydrate tolerance and insulin secretion in persons with indications of disturbed carbohydrate tolerance. Preliminary results and follow-up observations for 7 years].

115 patients with normal weight and 15 adipose persons with suspicion of a disturbance of the carbohydrate metabolism were characterized by means of a glucose infusion test lasting two hours concerning the carbohydrate tolerance and insulin secretion. Longitudinal analyses of the spontaneous behaviour of the carbohydrate tolerance and insulin secretion depending on the degree of the carbohydrate tolerance up to duration of the observation of 7 years. A deterioration of the carbohydrate tolerance was to be proved in 21% of 87 persons with normal carbohydrate tolerance within two years. With normal carbohydrate tolerance within two years. With an increase of the duration of the observation up to 7 years the frequency of disturbances of the carbohydrate tolerance increases to 30%. This development cannot be coordinated to a certain type of insulin secretion. In the individual case a deterioration of the carbohydrate tolerance may be associated with an increase or reduction of the glucose stimulated insuline secretion. An improvement of the carbohydrate tolerance was observed in 15 (54%) of 28 patients with disturbed carbohydrate tolerance within 2 years. In a group with pathological carbohydrate tolerance this development was associated with a significant reduction of the basic and glucose stimulated insulin secretion. In all patients with improved carbohydrate tolerance on the side of the insulin secretion primarily the type of "normal response" was present. The lacking relation between changes of the B-cell function and the carbohydrate tolerance emphasizes the importance of other factors, such as a peripheral insulin resistance, for the development of disturbances in the carbohydrate metabolism.

Carbohydrate Metabolism↗
PubMed1980

Investigation of insulin sensitivity in early diabetes. I. Procedure for the determination of insulin responsiveness in vivo.

Twenty-three normal weight subjects without any heredity of diabetes were characterized by a 2-hour glucose infusion test. All persons showed a normal carbohydrate tolerance and normal biphasic insulin secretion pattern. For the determination of insulin sensitivity a 1-hour priming dose--constant infusion technique was used. Two 30-minute-periods of insulin infusion (8 and 16 mU/kg, primed by a start injection of 1 and 2 mU/kg, respectively) provoked a decrease of plasma glucose and FFA concentrations by 35 +/- 12.5% and 55 +/- 30.2%, respectively. Values lower than 22.5% (glycemia) or 25% (FFA) indicate a diminished insulin responsiveness. The metabolic clearance rate of insulin did not change at several concentrations of IRI. Thus, the proposed procedure is suitable to study the insulin sensitivity in vivo.

Blood Glucose↗
PubMed1979

[Incidence of gestational diabetes and changes in insulin secretion of pregnant women (author's transl)].

The 50-g oGTT was applied to pregnant women suspected of having contracted diabetes. Carbohydrate tolerances were pathological in 23.6 per cent of all probands and in borderline vicinity in 17.9 per cent. The oral glucose tainting test thus worked according to expectation by revealing a relatiively high frequency of disorders of the carbohydrate tolerance. Yet, impaired insulin secretion was established rarely, with high response having been recorded from only seven per cent and delayed insulin secretion from 4.1 per cent. Low response was not found at all. No correlations were found to exist, by the 50-g oGTT, between disorders of the carbohydrate tolerance and insulin secretion. The groups involved differed but little with regard to their IRI mean value curves. Sugar excretion in urine was found to be increased with significance in response to pathological carbohydrate tolerance in early pregnancy and may be used as a complementary criterion for diagnosis.

Blood Glucose↗
PubMed1978

[Incidence of gestational diabetes as well as changes in insulin secretion during pregnancy. 1. Studies on pregnant women suspected of diabetes using the glucose infusion test (GIT)].

Based on the glucose infusion test, we find with 17.9 per cent of a group of anamnestically tainted pregnant women gestational diabetes, and with 5.7 per cent of this group a carbohydrate tolerance with disturbed boundaries. With probands having a carbohydrate tolerance with disturbed boundaries we find a significantly more frequent IRI-high-response. This coincidence of a carbohydrate tolerance in the border range and of an IRI-high-response might correspond to the early asymptomatic stage of diabetes. In the following stages, there will take place a depression of the early insulin phase with a pathological carbohydrate tolerance of the pregnant women in the sense of a gestational diabetes. With probands exhibiting a disturbed carbohydrate tolerance, a diminished depression of free fatty acids is found. The total lipid content and cholesterol are not essentially changed. With women suffering from gestational diabetes urinary sugar excretion is significantly higher than with probands showing a normal carbohydrate tolerance.

Adult↗
PubMed1977

[Obesity as a metabolic risk factor].

On the basis of the results of clinico-experimental examinations and of animal experiments the importance of obesity as metabolic factor of risk is confirmed and hereby the diabetes mellitus as well as cardiovascular effects are particularly taken into consideration. Conclusions are made relevant to practice and it is particularly referred to the central position of the B-cells for the pathogenesis of diabetes as well as to prophylactic and early therapeutic measures.

Adult↗