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Biomedical subjects

J F Koster

Publications and source records attributed to J F Koster.

At least 127 records · Page 7Linked to original sources
PubMed1977

High density lipoprotein and low density lipoprotein catabolism by human liver and parenchymal and non-parenchymal cells from rat liver.

The capacity of the homogenates from human liver, rat parenchymal cells, rat non-parenchymal cells and total rat liver for the breakdown of human and rat high density lipoprotein (HDL) and human low density lipoprotein (LDL) was determined. Human HDL was catabolized by human liver, in contrast to human LDL, the protein degradation of which was low or absent. Human and rat HDL were catabolized by both the rat parenchymal and non-parenchymal cell homogenates with, on protein base, a 10-times higher activity in the non-parenchymal liver cells. This implies that more than 50% of the total liver capacity for HDL protein degradation is localized in these cell types. Human LDL degradation in the rat could only be detected in the non-parenchymal cell homogenates. These findings are discussed in view of the function of HDL and LDL as carriers for cholesterol.

Animals↗
PubMed1976

Leukocyte peroxidase in Spielmeyer-Vogt's disease.

Leukocyte peroxidase activity was estimated in 5 patients with the juvenile form of neuronal ceroid lipofuscinosis (Spielmeyer-Vogt's disease) and in 15 healthy controls. In contradiction to recent reports normal activity of p-phenylene diamine mediated peroxidase was found in the patients. The possible role of contamination of the white cell preparation with hemoglobin is discussed.

Adolescent↗
PubMed1976

Isoenzyme pattern of phosphorylase in white blood cells and fibroblasts from patients with liver phosphorylase deficiency.

Isoenzyme patterns of phosphorylase in white blood cells and cultured fibroblasts of a patient affected with liver-type phosphorylase deficiency were studied. Three bands were observed with electrofocusing of white blood cells and liver from controls. In the white blood cells of the patient only two bands were observed. Patient and control fibroblasts showed two bands, probably identical to the two bands observed in the patient's white blood cells. These results indicate that the liver-type phosphorylase is not expressed in the cultured fibroblasts.

Brain↗
PubMed1976

Physico-chemical and immunological properties of acid alpha-glucosidase from various human tissues in relation to glycogenosis type II (Pompe's disease).

The physico-chemical and immunological properties of acid alpha-glucosidase from various human tissues have been studied. Heat stability of acid alpha-glucosidase from heart, liver and skeletal muscle is identical, but for kidney some different results are obtained. Identical isoelectrofocussing patterns are found for heart, liver and skeletal muscle. Furthermore, the effect of antiserum against human liver acid alpha-glucosidase on the activity of acid alpha-glucosidase from various tissues is studied. The results are discussed in relation to glycogenosis type II (Pompe's disease).

Antigen-Antibody Reactions↗
PubMed1976

beta-Galactosidase deficiency in an adult: a biochemical and somatic cell genetic study on a variant of GM1-gangliosidosis.

Biochemical data are presented of a 29-year-old male, who shows progressive psychomotor retardation and a beta-galactosidase deficiency in leucocytes and cultured skin fibroblasts. Somatic cell hybridization studies show that this variant of GM1-gangliosidosis is based on a different gene mutation than is present in types 1 and 2. No complementation is observed in fusion experiments with cells from type 3 variant.

Adult↗
PubMed1975

Identity and activities of lysosomal enzymes in parenchymal and non-parenchymal cells from rat liver.

1. Intact parenchymal and non-parenchymal cells were isolated from rat liver. The parenchymal cells were purified by differential centrifugation, while non-parenchymal cells were obtained free of parenchymal cell contamination by preferentially destroying the parenchymal cells with the aid of pronase (0.25%). 2. The ability to isolate pure intact parenchymal and non-parenchymal cells permitted the characterization and measurement of specific activities of various lysosomal enzymes, representing the main functional hydrolytic activities of the lysosomes in these distinct cell types. 3. Lysosomal enzymes catalysing the hydrolysis of the terminal carbohydrate moiety of glycoproteins and glycolipids were not particularly enriched in the non-parenchymal cells as compared to parenchymal cells. The ratio of the specific activities of non-parenchymal cells over parenchymal cells varied between 0.7 for N-acetyl-beta-D-hexoseaminidase to 2.1 for alpha-glucosidase. This suggests no specific role of the non-parenchymal cells in the hydrolysis of terminal carbohydrate moieties of glycoproteins and glycolipids. 4. The enzymes acid phosphatase and aryl sulphatase, representing the phosphate and sulphate hydrolyzing activities, were enriched in the non-paranchymal cells as compared to the parenchymal cells by a factor of 2.5. 5. The most important peptidase cathepsin D, representing protein breakdown capacity, is enriched in the non-parenchymal cells as compared to parenchymal cells by a factor 6.0, suggesting a possible specific function of non-parenchymal cells in protein breakdown. 6. The most enriched lysosomal enzyme, representing lipid hydrolysis, is acid lipase, which is enriched in the non-parenchymal cells with a factor of 10. 7. The distribution of lysosomal enzymes between parenchymal and non-parenchymal cells suggests different functional roles of the lysosomes in these cell types. It can be concluded that the non-parenchymal cells possess a set of lysosomal enzymes which makes them extremely suitable for a phagocytic and antimicrobial function in the liver.

Acid Phosphatase↗
PubMed1975

Normalisation of red blood cell pyruvate kinase in pyruvate kinase deficiency by riboflavin treatment.

A patient with an erythrocyte glutathione reductase activity of 50% of the normal value and an abnormal pyruvate kinase (PK) was given 36 mg riboflavin daily for 6 months. The glutathione reductase activity was restored and the abnormal pyruvate kinase was converted to normal. The clinical state of the patient improved. It can be concluded that the abnormality of PK, at least with this patient, is a secondary effect. Therefore, it is suggested that other abnormalities be searched for when an altered PK is detected. Treatment of this abnormality will help the patients more efficiently.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1975

Prenatal diagnosis of type II glycogenosis (Pompe's disease) using microchemical analyses.

1. In order to reduce the time interval between amniocentesis and prenatal diagnosis of Pompe's disease microchemical techniques were used for assay of acid alpha-1,4-glucosidase activities in cultured amniotic fluid cells. 2. Microtechniques used on homogenates of cultured amniotic fluid cells enabled the waiting period to be reduced to 2-3 weeks. 3. When dissected lyophilized groups of 200-300 cultured cells were analyzed, a prenatal diagnosis was possible at about 10 days after amniocentesis. 4. The acid alpha-1,4-glucosidase activity in the amniotic fluid supernatant is not informative in prenatal diagnosis of Pompe's disease. 5. Conditions of cell cultivation such as length of time in culture were found to influence markedly the acid alpha-1,4-glucosidase activity in cultured amniotic fluid cells. 6. For a reliable prenatal diagnosis of metabolic disorders primary cultures of control amniotic fluid cells should be used and the analytical results from the pregnancy at risk should be compared with primary cultures of control amniotic fluid cells and with those in cultured fibroblasts from heterozygous carriers, and an affected sibling from the particular family.

Amniocentesis↗