PubMed Health⌕ Search

Biomedical subjects

M Lober

Publications and source records attributed to M Lober.

At least 19 recordsLinked to original sources
PubMed1991

[Some problems in standardization of fructosamine tests].

The degree of nonenzymatic glycation of serum proteins was estimated in 500 nondiabetic subjects and in 124 Type 2 diabetic out-patients. The values were evaluated in relation to a DMF calibration curve, a secondary glycated protein standard and to serum protein concentrations. Neglecting the evaluation with respect to the protein concentration 0.4% of the samples from nondiabetics and 9% from diabetic patients would have been incorrectly interpreted. The fructosamine values from nondiabetic subjects showed a Gaussian distribution. The use of secondary protein standards is a premise to a widespread application of the fructosamine assay in diabetic care. The calibration of such secondary glycated protein standards results in some problems when using DMF protein mixtures as primary standards, because albumin preparations from the same or different suppliers gave variable standardization curves.

Adult↗
PubMed1990

Complement component 3 (C3) genetics and diabetes mellitus.

Complement component 3 (C3) phenotype and allele frequencies were defined in 312 patients with type-1 diabetes (insulin-dependent diabetes mellitus), 256 patients with type-2 diabetes (non-insulin-dependent diabetes mellitus), 114 apparently non-diabetic first-degree relatives of type-1 diabetics, in 10 families (29 members) with a familial history of type-1 or type-2 diabetes, in 181 patients with coronary heart disease and 255 subjects with arterial hypertension. 512 blood donors served as controls. All persons investigated were Europeans. There is no evidence that genes linked to C3 influence susceptibility to type-1 and type-2 diabetes and to their late complications as well as to atherosclerosis and essential hypertension. The distribution of apolipoprotein E phenotypes in patients and controls was likewise not significantly different. The combined evaluation of data from linked genes (C3 and apo E) could not improve the results. Deductions of C3 as a genetic disease marker have to be interpreted with caution.

Alleles↗
PubMed1988

ATPase and acetylcholinesterase activities in erythrocyte membranes after incubation with glucose and in streptozotocin diabetic rats.

Enzyme activities of ATPases and acetylcholinesterase from isolated erythrocyte membranes (ghosts) were investigated before and after incubation with 50 mM glucose. Glucose incubation caused a time dependent loss of ATPase and acetylcholinesterase activities. Ghost enzyme activities in steptozotocin diabetic rats were found only insignificantly diminished.

Acetylcholinesterase↗
PubMed1988

Diminished adhesion of endothelial aortic cells on fibronectin and collagen layers after nonenzymatic glycation.

Adhesion of bovine endothelial cells on fibronectin and collagen before and after nonenzymatic glycation in vitro has been studied. Nonenzymatic glycation of these proteins reduced their ability to bind endothelial cells. Furthermore, nonenzymatically glycated fibronectin failed to bind to normal and nonenzymatically glycated gelatin and to fibrin. So gelatin and fibrin Sepharoses can be used to separate highly glycated fibronectins from fibronectins with a low degree of nonenzymatic glucose substitution. Sodium dodecylsulfate polyacrylamide gel electrophoresis did not demonstrate a covalent cross-link between nonenzymatically glycated fibronectins. These results present further evidences for the role of nonenzymatic glycation of proteins in the development of vascular complications in long-term diabetes and of atherosclerosis.

Animals↗
PubMed1988

Complement component 3 (C 3) and diabetes mellitus.

Complement factor 3 (C3) phenotype and allele frequencies were defined in 312 patients with Type 1 diabetes (IDDM), 256 patients with Type 2 diabetes mellitus (NIDDM), 114 apparently healthy first-degree relatives of Type 1 diabetics, in 10 families (29 members) with a familial history of Type 1 or Type 2 diabetes, and 512 controls (blood donors). All persons investigated were Europeans. There is no evidence to suggest that genes linked to C3 influence susceptibility to Type 1 and Type 2 diabetes and to their late complications. C3 levels in blood plasma were found to be slightly elevated in both types of diabetes. But the C3 concentrations varied considerably within the groups. C3 split products were demonstrable in a high percentage in the blood plasma of freshly manifested Type 1 diabetic persons as well as in Type 1 diabetics with a duration of the disease of 1 to 3 years. C3 proteolysis could also be found in plasma of Type 2 diabetics (26%).

Adolescent↗
PubMed1987

Properties of in vitro nonenzymatically glycated plasma fibrinogens.

Nonenzymatic glycation of fibrinogen is species independent and depends only on the glucose concentration in the incubation mixture under selected in vitro conditions. An increased fibrin monomer aggregation in the presence of Ca2+ ions and a decreased proteolytic susceptibility of nonenzymatically glycated fibrinogens may favour the development of thrombophilic states. Blocking of lysine residues as well as restricted conformational changes induced by glucose attachment may be responsible for these effects. Fibrin stabilization by factor XIII is not impaired by nonenzymatic glycation of fibrinogen. Attachment of aortic endothelial cells to fibrin films from glycated fibrinogens is diminished. This phenomenon may be the result of blocked plasminogen activator binding sites in fibrin by nonenzymatic glycation. These effects may contribute in vivo to the accumulation of fibrin in those tissues most frequently affected by diabetic complications.

Animals↗
PubMed1986

The nonenzymatic glycation of proteins and nucleic acids, their importance for the development of diabetic complications, possible molecular basis of aging and autoimmunological processes.

The formation of nonenzymatic glycation products of proteins and nucleic acids appears to be a link between chronic hyperglycaemia and long-term diabetic complications and special forms of aging during normoglycaemia. The major effects of extended glycation include cross-linking of glycated proteins, attachment of soluble proteins to extracellular glycated matrices, conformational changes of proteins followed by altered functions and immunogenicity, and abnormalities in nucleic acid functions.

Aging↗
PubMed1985

[Plasma fibrinogen in female patients with genital cancer and its early stage].

Changes of plasma fibrinogen derivates in 54 female patients suffering from carcinomas of the genital system (36 with cervix carcinoma, 9 with ovarian carcinomas, 7 with carcinomas of the corpus uteri, 1 woman with a vulva and 1 patient with vaginal carcinoma) and 6 females with cervical intraepithelial neoplasia were investigated. It was shown, that the fibrinogen content and the concentration of soluble fibrin monomer complexes in blood plasma depend on the extension of the clinically diagnosed tumor. Furthermore, differently degraded fibrinogens were demonstrated to exist in the blood circulation. The extent of fibrinogenolysis did not correlate with the clinically diagnosed tumor stage.

Adenocarcinoma↗
PubMed1985

[Proteolytic changes in plasma fibrinogen from ovarian venous blood in patients with cervix cancer].

From 9 female patients suffering from carcinoma cervicis (8 women with a stage Ib, 1 woman with a stage IIa carcinoma) blood was taken immediately from the ovarian veins and a cubital vein after laparotomy on the occasion of a surgical intervention according to Wertheim-Held. Fibrinogen was isolated from plasmas by affinity chromatography at fibrin monomer Sepharose and characterized by SDS-PAGE. With one exception proteolytically changed fibrinogens could be demonstrated in all plasmas. In 7 cases the fibrinogens from ovarian blood were more degraded than fibrinogen derivates in the blood obtained from cubital veins. It is assumed that the proteinase and/or plasminogen activator activities of tumor tissues are of importance for the observed proteolytic effects.

Adenocarcinoma↗
PubMed1984

[Changes in the cholinesterase activity and glucose concentration in the blood induced by paraoxon in rabbits immunized against paraoxon].

The immunization of rabbits with a paraoxon-HSA-conjugate resulted in an antibody response with titres of 1:25000 to 1:100000 of antisera dilution and average affinity constants K0 of 10(6) M-1 and heterogeneity indices of 0.8 to 0.9 calculated by means of the Sips equation. The serum cholinesterases and the erythrocyte acetylcholinesterase in immunized rabbits were protected against a stronger inhibition by parenteral application of paraoxon. An increase of blood glucose after paraoxon application to immunized rabbits could not be observed but was detectable in unimmunized animals.

Acetylcholinesterase↗
PubMed1983

[Alpha 1-globulin levels in patients with cancer of the genital tract].

Electrophoretical investigations of plasma protein patterns in 59 patients suffering from carcinomas of the genital system provide some evidence, that the alpha 1-globulin fraction amounts to only 2% in 25% and less than 2% of total plasma protein in 19% of the examined persons. The normal range of alpha 1-globulin is 2 to 4%. Low alpha 1-globulin values are mainly the result of a diminished alpha 1-antitrypsin level.

Alpha-Globulins↗