Search PubMed⌕ Search

Biomedical subjects

G Utermann

Publications and source records attributed to G Utermann.

At least 199 records · Page 11Linked to original sources
PubMed1978

Polymorphism of apolipoprotein E. I. Methodological aspects and diagnosis of hyperlipoproteinemia type III without ultracentrifugation.

Two methods for phenotyping apolipoprotein E are compared. One is based on preparation of VLDL by conventional ultracentrifugation, whereas the other uses heparin/Mg precipitation of VLDG. In principle, the same results were obtained by both methods. However, the group limits for the three different phenotypes Apo E-N, Apo E-ND and Apo E-D were slightly different by the two methods. Phenotype Apo E-D - the phenotype characterizing type III dyslipoproteinemia - is clearly definable by both methods. Hence the precipitation-I.E.F. method for Apo E phenotyping provides a simple tool for genetic and population genetic studies and also for the routine diagnosis of hyperlipoproteinemia type III, based on the only specific marker known for this disease.

Apolipoproteins↗
PubMed1977

Studies on the metabolic defect in Broad-beta disease (hyperlipoproteinaemia type III).

The apoprotein composition of the main lipoprotein fractions (VLDL, LDL-1, LDL-2 and HDL) was studied initially in 15 patients with Broad-beta disease. Analytical isoelectric focusing of urea-soluble apo-VLDL and apo LSL-1 demonstrated a variant pattern of the polymorphic Apoprotein E with a deficient Apo E-III band in all patients. The Apo E-III deficiency pattern was seen in only six out of 304 hyperlipidaemic controls. These six Apo E-III deficient controls had characteristic signs of Broad-beta disease, and thus represented patients not previously recognized as having the disorder. The Apo E focusing patterns were constant on repeated examinations and were stable under different metabolic conditions. The data show that Apo E-III deficiency in VLDL is a specific qualitative marker for Broad-beta disease, allowing an unequivocal diagnosis that had not been possible previously. Indirect evidence suggests that Apo E-III deficiency is the basic lipoprotein abnormality underlying the familial dyslipoproteinaemia.

Adult↗
PubMed1976

Prenatal diagnosis of homoxygous familial hypercholesterolemia: investigation of a case at risk.

Cultivated amnion cells obtained from a pregnancy at risk for the homozygous form of familial hypercholesterolemia were analyzed, as were fibroblasts from normal, heterozygous and homozygous controls. Three different methods were employed in order to compare their diagnostic value: i. Acetate incorporation into the cellular 3beta-OH-sterol fraction; ii. LDL-binding to the cell surface receptor; and iii. Oleate incorporation into the cholesterylester pool of the cells after addition of LDL to lipoprotein-deficient growth medium. The best discrimination between normal, heterozygous and homozygous cells was achieved using the third technique. On the basis of the acetate incorporation analysis, we concluded that the child is not homozygous, but probably completely unaffected. This diagnosis was confirmed by repeated determinations of plasma cholesterol levels during the first 11 months of life. Our investigations further substantiate the specularion that prenatal diagnosis of this disorder is possible.

Acetates↗
PubMed1975

Lipoproteins in lecithin-cholesterol-acyltransferase(LCAT)-deficiency. II. Further studies on the abnormal high-density-lipoproteins.

The lipoproteins from two sibs with familial lecithin-cholesterol-acyltransferase(LCAT)-deficiency were further characterized. Comparatively lipoproteins from patients with secondary LCAT-deficiency were studied. Both groups of patients had particles of unusual size and shape in the alpha1-(HD-2)-lipoprotein subfraction. The abnormal HDL-2 particles were disk-like in appearance with a major axis of about 180 A and a minor axis of about 40 A and tended to aggregate into long coinlike stacks. The abnormal HDL-2 particles contained the normal protein constituents of HDL Apo A-I, Apo A-II and Apo C but in addition a major polypeptide with a M.W. of 39000 not seen in significant amounts in normal high-density-lipoproteins. This polypeptide was found identical in size, isoelectric focusing and immunochemically with an arginine-rich normal polypeptide constituent of very-low-density-lipoproteins designated apoprotein E. Presence of this protein marker in the HDL allowed the specific immunological detection of the abnormal HDL-2 (LP-E) in plasma. Further minor biochemical abnormalities were observed in the lipoproteins of the patients with familial LCAT-deficiency. However, the main protein constituents of their HDL, the Apo A, Apo C and Apo E polypeptides, were found to be identical electrophoretically and by analytical isoelectric focusing with their normal counterparts. The data suggest that the basic genetic defect in the hereditary disease leads to a deficient activity of the LCAT-enzyme and that all abnormalities in the lipoprotein spectrum are secondary.

Acetyltransferases↗
PubMed1975

Plasma lipoprotein abnormalities in a case of primary high-density lipoprotein (HDL) deficiency.

A 53-year-old patient with primary HDL-deficiency is reported. About 2% of the normal concentration of alpha1 HDL was present in his plasma. The alpha1-high-density-lipoproteins separated into two fast-moving components in polyacrylamide gel electrophoresis. The Apo HDL contained both the main apolipoproteins, Apo A-I and Apo A-II, but in disproportionally reduced amounts, the concentration of Apo A-I being reduced about 360-fold, and that of Apo A-II about 14-fold. Concomitantly, the amount of the Apo C polypeptides in the HDL-fractions was decreased to about 5.5% and the activity of the enzyme lecithin cholesterol acyltransferase (EC 2.3.1.4.3) in plasma was found to be only 40% of normal. Apoprotein D was present in the LDL in association with Apo B, forming an abnormal, fast-moving LDL-complex. Apo A-I and Apo A-II were both of normal size as determined by SDS-PAGE, and reduction with thiols resulted in the shift of the M.W. of Apo A-II from 17,000 daltons to about 8,500 daltons. Both proteins were found in the same position as their normal counterparts in analytical isoelectric focusing. The most likely explanation for the multiple lipoprotein abnormalities seems to be that a defect in the regulation or structure of Apo A-I is the basis of the HDL-deficeincy.

Blood Protein Electrophoresis↗
PubMed1975

Isolation and partial characterization of an arginine-rich apolipoprotein from human plasma very-low-density lipoproteins: apolipoprotein E.

A water-insoluble apoprotein was isolated from apo-VLDL by column chromatography on Sephadex G-200 in sodium dodecylsulfate followed by preparative polyacrylamide gel electrophoresis in a discontinous sodium dodecylsulfate system, or by preparative electrophoresis alone. The protein was similar in amino acid composition to the "arginine-rich protein" reported by Shore and Shore. It represented about 10% of the total protein mass of VLDL. The apoprotein showed one single band with an apparent Mr of 39000 in sodium dodecylsulfate gel electrophoresis, and was homogeneous in gel electrophoresis at pH 8.9 In 8M urea. Immunochemical studies also showed homogeneity of this protein, and antisera prepared against it did not react with any other of the well known apolipoproteins, but did react with VLDL and apo-VLDL preparations. Analytical isoelectric focusing in 8M urea resulted in a heterogeneous banding pattern showing three major polypeptides with pI values of 5.5, 5.6 and 5.75. Thus this apolipoprotein clearly differs from the apo-B and apo-C polypeptides of VLDL as well as from apoproteins A and D in its molecular weight, amino acid composition, focusing behavior and immunochemical properties.

Amino Acids↗