Biomedical subjects
Publications and source records attributed to U Bienzle.
Separation of Triton X-100-extracted red-cell membrane proteins by linking SDS-electrophoresis in polyacrylamide to isoelectric focusing revealed differences between young and ageing erythrocytes in vitro, which are attributed to progressing conformational changes among membrane proteins.
Five electrophoretically slow-moving genetic variants of glucose 6-phosphate dehydrogenase are described: four are from Nigeria and one is from Togo. All variants have normal or moderately reduced activity, and they are not associated with adverse clinical or haematological manifestations. Three variants have been fully characterized and are different from all previously described ones. Two variants have been partially characterized and at least one of them is also probably new. The overall population incidence of sporadic variants of G6PD in the Nigerian population is 0-3%. In the course of this study a previously described ion-exchange chromatographic technique for the characterization of G6PD variants has been extensively evaluated. Data are given on ten different variants to demonstrate the high resolving power of this technique.
A patient is presented who manifested the typical clinical and pathological features of congenital immunodeficiency and agranulocytosis (reticular dysgenesia). Treatment under gnotobiotic conditions enabled the measurement of immunogical parameters up to the 17th week of life with the following results: negative skin test, low response to phytohaemagglutinin, weak response in the mixed leukocyte culture and very few E rosettes. Peripheral lymphocytes and lymphocytes in the lymphatic tissues were markedly decreased. Humoral immunoglobulins and plasma cells in the organs were decreased. The in vitro culture of hemopoietic cells showed a diminished content of myelopoietic progenitor cells ("committed stem cells"). It is concluded that the disease may be primarily a defect of stem cells with regard to differentiation in myelopoiesis or lymphopoiesis.
Bone marrow transplantation is an experimental therapy, which has been used with success in patients with aplastic anemia, severe combined immunodeficiency and leukemia. We report here on the procedure of transplantation and the possible difficulties which can be encountered.
A case of connatal malaria due to Plasmodium vivax in a newborn of turkish origin is presented. Most likely the infection was acquired by materno - fetal transfusion during labor. Pathophysiological aspects and mode of transmission of this rare disease are discussed.
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Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a major cause of severe neonatal jaundice in Nigeria, but not all G6PD-deficient babies become jaundiced. Neonatal jaundice not attributable to G6PD deficiency nor to any other known aetiology is also common. In an effort to explain these two facts, we have measured the levels of the three enzymes G6PD, glutathione peroxidase (GSHPX), and glutathione reductase (GSSGR) in 38 jaundiced newborns, 26 control newborns, and 44 normal adults, all of them males. We could not yet prove an additive effect of GSSGR or GSHPX deficiency with G6PD deficiency in causing jaundice. There was no evidence that low levels of GSHPX per se are associated with jaundice. However, jaundiced newborns with normal G6PD had significantly lower levels of GSSGR than control newborns with normal G6PD. These data suggest that a relatively low activity of GSSGR, a riboflavin-dependent enzyme, may predispose the red cells to accelerated destruction in the neonatal period.
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Three cases of congenital selective malabsorption of vitamin B12 (Imerslund-Grasbeck syndrome) are presented. Pathophysiological aspected and clinical symptoms of this disease are discussed together with other megaloblastic anaemias in childhood caused by vitamin B12 deficiency.
A new case of congenital stomatocytosis associated with haemolytic anaemia, increased autohaemolysis, abnormalities in the erythrocyte metabolism, increased osmotic fragility and shortened erythrocyte survival is described. Intracellular cation concentrations are abnormal: Red cell sodium is high, and potassium is low. The pump rate for monovalent cations is increased.
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The glucose 6-phosphate dehydrogenase (G6PD) genotype was determined in 100 male patients with homozygous sickle cell anemia (SS) by a combination of quantitative assay, cytochemical testing, and starch-gel electrophoresis. Of the 100 patients tested, 16 were found to be G6PD deficient (GdA-), AND 84 G6PD normal (22GsA and 62 GdB). This distribution of G6PD genotypes did not differ significantly from that observed in the general population. The level of G6PD activity in GdA- SS patients was nearly always higher than in G6PD-deficient subjects who did not have an associated hemolytic state, but it was nearly always lower than in G6PD-normal subjects. The clinical course of sickle cell disease, including the degree of anemia, was not milder in GdA- than in G6PD-normal patients but could not be proved to be significantly more severe. It was concluded that in this community the incidence of G6PD deficiency in sickle cell anemia was not greater than would be expected by chance, and there was no evidence that the coexistence of the GdA- gene in SS patients ameliorated their disease.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.