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Biomedical subjects

W Tillmann

Publications and source records attributed to W Tillmann.

At least 37 records · Page 2Linked to original sources
PubMed1981

Role of the spleen in congenital stomatocytosis associated with high sodium-low potassium erythrocytes.

A girl of German origin with severe congenital hemolytic anemia was found to have overhydrated erythrocytes with markedly increased sodium and reduced potassium concentrations. The cells were stomatocytic with increased osmotic fragility and autohemolysis. Their excessively increased energy production was mainly used for active cation transport. The cells were highly vulnerable to metabolic depletion. Their normal deformability was reduced rapidly during deprivation of glucose. In acidic, hypoglycemic environment of the splenic pulp the cells become swollen and lysed. After splenectomy anemia improved though increased hemolysis persisted.

Adolescent↗
PubMed1981

Flexibility of erythrocytes in juvenile diabetes mellitus.

The rheological properties of erythrocytes of 47 diabetic children and adolescents were studied. Deformability of red cells of 32 patients under "poor" metabolic control was markedly decreased while the deformability of red cells of patients (15 individuals) under "good" control was normal. This diminished flexibility of erythrocytes of patients under "poor" control can be explained partly by an increased concentration of free fatty acids in plasma. Moreover we found a decreased fluidity of the intracellular hemoglobin caused possibly by a decreased concentration of 2, 3-diphosphoglycerate in the cells.

Adolescent↗
PubMed1980

Rheological properties of young and aged human erythrocytes.

Rheological properties were studied of young and old human erythrocytes from healthy adults. Viscosity measurements of packed erythrocyte suspensions as well as filtration of cells through polycarbonate sieves show that young cells are more flexible than aged ones. Since deformability of erythrocytes is the product of cell shape, flexibility of the membrane and fluidity of the intracellular hemoglobin, we studied the manner in which these factors are relevant to the diminished flexibility of aged erythrocytes. The biconcave cell shape is maintained during the process of aging. The viscosity of packed ghost suspensions from aged erythrocytes is increased versus that of young ones. The diminished flexibility of old ghosts correlates well with their smaller cell volume. The fluidity of the hemoglobin in the interior of the cells is decreased as indicated by an increased hemoglobin content of the isolated ghosts. We conclude that aged erythrocytes loose their deformability as a result of both a decreased fluidity of the intracellular hemoglobin and a diminished flexibility of the membrane.

Blood Viscosity↗
PubMed1980

Endocrine studies in Blackfan-Diamond anemia: evidence for hypothalamic-pituitary dysfunction under frequent transfusion therapy.

A 13 year old boy with Blackfan-Diamond anemia treated with frequent transfusions was investigated for endocrine abnormalities. Prepubertal plasms LH and FSH values, lack of sleep-related hormone rhythms of the gonadotropins, as well as prepubertal responses of LH and FSH to acute stimulation with LHRH strongly suggests that a hypothalamic-pituitary abnormality is the cause of the hypogonadotropic hypogonadism observed in this patient. As a result of impaired stimulation of the gonads plasm testosterone was prepubertal. A three-to fourfold increase of basal plasma PRL values was found without any signs of a typical sleep-dependent increase. Values obtained ranged between 21 ng/ml and 24 ng/ml (normal range 5-8 ng/ml). A normal response to TRH stimulation was found. These results suggest that hemosiderosis may be responsible for the hyperprolactinemia as a result of hypothalamic-pituitary dysfunction. Furthermore, dysfunction is demonstrated by prepubertal responses of LH and FSH to LHRH stimulation.

Adolescent↗
PubMed1980

Deformability of erythrocytes in iron deficiency anemia.

The rheological properties of erythrocytes of 14 patients with iron deficiency anemia were studied by filtration of cells through polycarbonate filters with a nominal pore diameter of 5 micron and by viscosity measurements of erythrocyte suspensions with a hematocrit of 80%. Erythrocytes of the patients passed through the filter pores more slowly than the cells from controls. The diminished deformability of the erythrocytes of the patients was solely due to an unfavorable ratio of cell surface area to microcytic cell volume. The viscosity of the ghost suspensions of the patients showed a normal flexibility. The hemoglobin content of the isolated ghosts was diminished, indicating an increased hemoglobin fluidity in the interior of the intact cells. The viscosity of erythrocytes of the patients was slightly increased at low shear rates but was normal at intermediate and high shear rates. We suggest that the decreased erythrocyte flexibility of microcytosis at low shear rates is no longer present at higher shear rates because of an increased fluidity of the intracellular hemoglobin. We discuss whether or not this mechanism also operates in vivo. The in vitro diminished deformability of erythrocytes explains the shortened survival of the patients' erythrocytes in vivo.

Adolescent↗
PubMed1980

[Severe cardiogenic hemolytic anemia with decreased flexibility of erythrocytes following surgical correction of mitral valve stenosis (author's transl)].

After surgical correction of a common atrium and closure of a mitral cleft, a mitral stenosis developed in a 5 year old girl. Postoperatively a pronounced hemolysis developed necessitating multiple blood transfusions. Rheologic measurements showed that hemolysis was due to a loss of erythrocyte deformability after mechanical damage. On the basis of these measurements it was concluded that the mitral stenosis was most likely responsible for this mechanical damage. Following another surgical correction of the mitral valve there was no hemolysis anymore.

Anemia, Hemolytic↗
PubMed1979

Rheological properties of erythrocytes in heterozygous and homozygous beta thalassaemia.

The rheological properties of erythrocytes were studied in 12 heterozygous and nine homozygous beta thalassaemia patients, using filtration of erythrocytes through polycarbonate sieves with a pore diameter of 5 micron and viscosity measurements of erythrocyte and ghost suspensions. Erythrocyte deformability of all patients was decreased. In the heterozygous patients moderately diminished flexibility of cells was due to microcytosis of erythrocytes. Rigidity of erythrocytes in homozygous patients was due to altered cell shape, diminished fluidity of haemoglobin, and in splenectomized patients to the presence of inclusion bodies. Membrane flexibility of erythrocytes remained unaltered. We suggest that the decreased fluidity of haemoglobin as well as the presence of inclusion bodies result from the excess of alpha chains in erythrocytes of homozygous patients. The haemoglobin fluidity of erythrocytes of one patient with thalassaemia intermedia was unchanged. The flexibility of these cells was only moderately altered. In four patients who needed transfusions every 1--4 weeks deformability of transfused erythrocytes was likewise decreased when compared to controls. Erythrocyte suspensions obtained from the splenic artery and vein during splenectomy showed decreased flexibility of transfused cells after their passage through the spleen.

Adolescent↗
PubMed1979

Rheologic properties of erythrocytes in Duchenne muscular dystrophy.

The transformation of erythrocytes into echinocytes by suspension in isotonic phosphate buffer was increased in patients with Duchenne muscular dystrophy (DMD) as compared to healthy controls. The transformation was enhanced when glass slides instead of polystyrole slides were used for observation. Viscosity of erythrocyte suspensions with a hematocrit of 80% was the same in patients and controls. The mean flow rate of erythrocyte suspensions in autologous plasma was only slightly reduced in the patient group, but decreased markedly after suspension of the cells in phosphate buffer, without as well as after preincubation with 10 mM Na salicylate. The decreased flow rate in patients is probably due to the increased number of echinocytes and not to an increased membrane rigidity, because the membrane flexibility of isolated ghosts, measured in a viscosimeter, was normal at all shear rates. Echinocyte formation in patients with DMD is strongly dependent on the techniques applied and difficult to evaluate quantitatively by phase contrast microscopy. Filtration of erythrocyte suspensions seems to be a more reliable, quantitative test for increased erythrocyte vulnerability.

Adolescent↗
PubMed1978

Pyruvate kinase-catalyzed ATP-formation in human red blood cell membranes.

Previous studies on the linkage between enzymatically catalyzed ATP-generating reactions in the red blood cell membrane and the sodium and potassium transport in the control of overall glycolysis of human erythrocytes were controversial. In this study a significant amount of pyruvate kinase activity is shown to be localized within the membrane. Membrane fragments produce 20.5 mumol of ATP per 10(10) membranes per hour from phosphoenolpyruvate and ADP. The kinetics of the membrane-localized pyruvate kinase do not differ from those of the enzyme from hemolysates. The results clearly document the presence of the second ATP-generating enzyme of glycolysis, pyruvate kinase, in human red blood cell membranes. The main fraction of the enzyme is deeply hidden in the lipid layers of the membrane. It can be demasked by mechanical desintegration of membranes at high levels of activity. It is suggested that the amount of the membrane-localized fraction of pyruvate kinase is related to the clinical severity of the hemolytic process in pyruvate kinase deficiency.

Adenosine Triphosphate↗
PubMed1978

[Porphyria erythropoietica congenita Günther and chloroquine (author's transl)].

Treatment of a six-year-old boy with porphyria congenita (Günther) by small amounts of chloroquine was followed by a sharp but transient increase of the urinary excretion of porphyrins. Moreover, a nearly complete normalization of the previously observed rigidity of the erythrocytes occurred. With respect to the possibility that this elevated rigidity plays an important role for the typical hemolysis connected with this porphyria, the application of chloroquine could be of therapeutic value for this disease.

Child↗
PubMed1978

[About the fixation of the transoxode for continuous measurements of fetal oxygen tension during labour (author's transl)].

Modified instruments for the fixation of an electrode for continuous pO2 measurements at the presenting part of the fetus sub partu are presented. A new Polyamid cap screw with a specially designed surface shape in order to keep the cement on the cap is described in detail. This simplified the handling of the electrode during application. Polyamid is resistant against Aceton, a commonly used solving agent for the applied Histoacryl cement. Thus the cap screw is reusable after cleaning.

Electrodes↗
PubMed1978

[On Harada's disease (author's transl)].

2 cases of Harada's disease are reported: in one cases there was a most severe uveo-encephalitis, the other showed only ocular manifestation (according to Shimizu in about 95% of the cases), the diagnosis was made sure by fluorescence photography.

Adult↗