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Biomedical subjects

M Gahr

Publications and source records attributed to M Gahr.

At least 127 records · Page 7Linked to original sources
PubMed1983

[Lysinuric protein intolerance].

We report the first case of lysinuric protein intolerance observed in Germany. A girl of Turkish ancestry suffered from severe dehydration at the age of 6 months after changing from breast milk to cow milk. Because of a microcytic hypochromic anaemia and erythrophagocytosis in the bone marrow a hematologic disease (Farquar's disease) was suspected. The definite diagnosis of lysinuric protein intolerance was eventually clarified by the following laboratory and clinical data: increased urinary excretion and low plasma concentration of lysine, arginine and ornithine, apathy, vomiting, diarrhea and hyperammonemia after an oral protein load, high serum LDH-activity, ferritinemia, and increased urinary excretion of orotic acid. Under therapy with citrullin and a low-protein diet the metabolic situation remained stable, even during infections. The bone marrow findings have been reported only in one further case of lysinuric protein intolerance.

Amino Acid Metabolism, Inborn Errors↗
PubMed1982

[Chronic neutropenia (author's transl)].

Chronic neutropenia was demonstrated in 6 members of a family including 3 children. Patient suffered from recurrent infections of the throat and upper respiratory tract and from lymphadenitis. There were no life-threatening diseases in any of the patients. In the bone marrow myelopoiesis showed arrested maturation. The previously reported forms of chronic neutropenia with mild clinical course are not differentiated either by haematological or by clinical data. We therefore suggest that they should be considered as one disease entity for the time being. This results in classification of childhood chronic neutropenia according to the clinical picture: a serious form (Kostmann) and cyclic neutropenia must be differentiated from the benign form described here.

Agranulocytosis↗
PubMed1982

Hemoglobin biosynthesis in juvenile erythroleukemia: evidence of imbalanced globin chain synthesis.

In three young patients with erythroleukemia in whom a partial reversion to the fetal pattern of erythropoiesis occurred there was found additionally an imbalance of globin chain synthesis. The synthesis of beta- plus gamma-chains exceeded that of the alpha-chains. In contrast, physiologic hemoglobin F production occurring in newborn infants and increased hemoglobin F production due to rapidly regenerating erythropoiesis in hereditary spherocytosis and after acute erythroblastopenia are characterized by a well balanced globin chain synthesis. These studies indicate that in distinct cases of juvenile erythroleukemia the genuine reversion to fetal erythropoiesis may be associated not only with a depression of hemoglobin synthesis but also with an imbalanced globin chain synthesis. Unlike adult cases of erythroleukemia without reversion to fetal erythropoiesis the imbalance of globin chain synthesis seems to be a more generalized phenomenon in these cases of juvenile erythroleukemia which is not confined to a particular red cell population.

Adolescent↗
PubMed1982

The pattern of reactivated fetal erythropoiesis in bone marrow disorders of childhood.

The expression of fetal characteristics of erythropoiesis (haemoglobin F concentration, haemoglobin A2 concentration, haemoglobin F cells, globin chain synthesis, carboanhydrase isoenzyme B, hexokinase isoenzymes, erythrocyte membrane antigens of the iI- and the ABH-system) was examined in red cells of twelve patients with different bone marrow disorders (juvenile chronic myeloid leukaemia (JCML), erythroleukaemia (EL), acute myelogenous leukaemia (AML), aplastic anaemia (AA) and Diamond-Blackfan anaemia (DB)). In JCML and EL all red cell parameters studied appeared to be fetal including the distribution of hexokinase isoenzymes. No fetal signs could be found in red cells of patients with AML. In two patients with DB who were treated by transfusion no fetal erythropoiesis could be detected. In one patient with DB under cortisone treatment i-antigen, ABH-antigens, haemoglobin F concentration, globin chain synthesis and hexokinase isoenzyme distribution were of the fetal or mixed type. In patients with AA only slight elevations of haemoglobin F were detectable. The nearly total reversion to fetal erythropoiesis in JCML and EL seems to be a part of the disorder itself, whereas in the other disorders the reactivation of fetal erythropoiesis could be the result of an erythropoietic stress.

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↗
PubMed1981

Pneumatosis intestinalis in children with leukaemia; report of three cases.

Three children with leukaemia (one with acute myeloid, two with acute lymphoblastic leukaemia) developed pneumatosis intestinalis during cytostatic treatment. The aetiology of pneumatosis intestinalis in these children could not be elucidated. Pneumatosis intestinalis may be caused by entry of gas into a bowel wall which is altered by steroid or cytostatic treatment. Otherwise, anaerobic bacteria may produce gas in the intestinal walls, therefore we treated all children with metronidazole.

Adolescent↗
PubMed1981

Red cell phosphoglucomutase (PGM)-deficiency: hereditary defect of the PGM1-locus.

Reduced phosphoglucomutase (PGM) activity (approximately 25% of normal) was found in erythrocytes from a healthy newborn infant. The PGM activity was also diminished (approximately 50% of normal) in the erythrocytes of the parents. No PGM1 isoenzymes were found in the erythrocytes of the propositus, as demonstrated by the starch gel electrophoresis. Both parents showed a normal distribution of the PGM1 isoenzymes. We propose a heterozygous state in the parents for a gene determining the activity of the PGM1 isoenzymes and that no activity of the PGM1 isoenzyme could be detected in erythrocytes of the propositus because of his homozygous state. In neonatal screening for galactosaemia red cell PGM deficiency gives false positive results, as does glucose-6-phosphate dehydrogenase deficiency.

Diagnosis, Differential↗
PubMed1980

Isoelectric focusing of hexokinase and glucose-6-phosphate dehydrogenase isoenzymes in erythrocytes of newborn infants and adults.

Isoenzymes of glucose-6-phosphate dehydrogenase and hexokinase from red cells of newborn infants were analysed by isoelectric focusing in polyacrylamide gel after partial purification. The pattern of isoenzyme distribution was compared with that of erythrocytes from adults. Glucose-6-phosphate dehydrogenase isoenzyme distribution was identical between erythrocytes from newborn infants and adults. Erythrocytic hexokinase isoenzymes patterns were different between newborn infants and adults. Erythrocytes from adults contain a hexokinase isoenzyme which has the same isoelectric point as rat liver hexokinase isoenzyme I (pH 6 . 01). This isoenzyme is lacking in red cells from newborn infants. Isoenzymes with the isoelectric properties of rat liver isoenzyme II (pH 5 . 48) were not detectable in red cells from adults, nor from newborn infants. The occurrence of an isoenzyme III in red cells remained unclear, because only a faint staining was observed in the corresponding region of erythrocytic gels. Preliminary results revealed a fetal type of hexokinase isoenzyme distribution in infants with an age of 10 months. This indicates that regulation of the synthesis of Hb F and of fetal hexokinase isoenzymes is not correlated.

Adult↗
PubMed1980

Different biochemical properties of foetal and adult red cell hexokinase isoenzymes.

The distribution of hexokinase isoenzymes was analyzed in erythrocytes from adults and newborn infants. Isolation by DEAE-cellulose chromatography revealed one main peak (I a) in erythrocytes from adults similar to hexokinase isoenzyme I from rat liver and a smaller peak (I b) which was eluted at a lower conductivity than rat liver isoenzyme II. In erythrocytes from newborn infants the peak I b dominated, isoenzyme I a was the smaller one. In adult erythrocytes an additional isoenzyme was detected which resembled rat liver isoenzyme III, this isoenzyme was absent in erythrocytes from newborn infants. The erythrocytic isoenzymes I a and I b differed in their kinetic properties. Isoenzyme I a had a slightly higher affinity for glucose (Km 47 microM) than isoenzyme I b (Km 100 microM). In the presence of 5mM Pi isoenzyme I b was more inhibited by glucose 6-phosphate than isoenzyme I a. 2.3-Diphosphoglycerate inhibited isoenzyme I b more than isoenzyme I a.

Adult↗
PubMed1979

Fetal properties in red blood cells of newborn infants.

In order to identify the fetal features in neonatal erythrocytes, cord blood was separated into seven fractions of varying specific density. Cell age in the single fractions was ascertained by means of reticulocyte count, glutamic-oxalacetic transaminase activity, and hemoglobin F concentration. The same procedures were used with blood of adults. With the exception of the fraction of neonatal blood with the highest specific density, the blood from neonates and adults correlated well for cell age and specific density. The highest specific density fraction of neonatal blood was found to contain a higher proportion of younger cells. The comparison of enzyme activities in the single fractions between neonates and adults showed that a high activity of glucose-6-phosphatedehydrogenase and enolase and a low activity of phosphofructokinase are typical fetal signs of neonatal cells.

Adult↗
PubMed1979

[The effect of iron on globin chain synthesis during the first six months of extrauterine life (author's transl)].

The mechanism regulating the formation of the globin-chains of hemoglobin is unknown. We have examined the formation of the alpha-, beta- and gamma-chains during the first 6 months in 10 healthy infants. Immediately after birth the ratio between rates of synthesis of alpha- and non-alpha-chains was 0.94 +/- 0.16. At 6 weeks the ratio was alpha/gamma + beta = 1.22 +/- 0.29. After oral therapy with iron (2 mg/kg) between ages 3 and 6 months the ratio alpha/gamma + beta became 0.92 +/- 0.14. Whether the imbalance at 6 weeks is due to a depression of alpha-chain synthesis or to a stimulation of gamma-chain and beta-chain synthesis remains unclear. Possibly in infants without iron therapy the gamma-chain synthesis is stimulated as was suggested by the comparison of the gamma/beta ratios in infants with and without iron therapy.

Age Factors↗
PubMed1978

A new defect of neutrophil chemotaxis and random motility in a child with recurrent bacterial infections and hyperimmunoglobulinemia E.

A new defect of chemotaxis and random motility of polymorphonuclear leukocytes is described in a patient with severe recurrent bacterial infections since early childhood. This defect seems to be intrinsic to the cells. The patient's plasma did not contain an inhibitor of chemotaxis. Addition of plasma to the patient's cells restored their chemotactic activity. High concentrations of immunoglobulin E were found in the patient's plasma. Phagocytosis, bacterial killing, and reduction of nitroblue tetrazolium salt were normal. Histological examination of lung tissue revealed a pattern similar to that observed in chronic granulomatous disease.

Bacterial Infections↗
PubMed1978

Glycosylated hemoglobins and their relation to the control of juvenile diabetes mellitus.

Patients with juvenile diabetes mellitus were studied over a period of six months. During this time their metabolic control was classified and the relation between the blood concentration of the glycosylated hemoglobins Hb A1a + b + c and the degree of diabetic control was established. 12 out of 37 diabetic children were under good control, whereas 6 patients were poorly controlled. Well controlled children had low concentrations of glycosylated hemoglobins, within the range of non-diabetic subjects. Those under poor control showed an almost twofold increase of the concentration of these minor hemoglobins. Hb A1a + b + c levels of 8 newly diagnosed diabetics were also extremely elevated. Since the hemoglobin-sugar linkage is irreversible, these components remains much longer elevated than the blood glucose itself. It is concluded that the determination of Hb A1a + b + c levels is a valuable tool for the evaluation of the efficiency of diabetic therapy in addition to blood and urinary glucose measurements.

Adolescent↗
PubMed1977

[Biochemical characterization of a new variant of glucose-6-phosphate dehydrogenase (G-6-PD) deficiency with favism: G-6-PD Bielefeld (author's transl)].

A new variant of G-6-PD with favism has been detected in a German family. After partial purification the enzyme was biochemically characterized. It revealed normal electrophoretic mobility, normal thermostability and a flat pH-activity curve. The Km-value for G-6-P was reduced, whereas this value was normal for NADP. The substrate analogues 2-desoxy G-6-P, Gal-6-p and deamino-NADP were utilized to increased rates. The biochemical data were compatible with the benign clinical course.

Adult↗
PubMed1977

Membrane deformability of erythrocytes with glucose-6-phosphate dehydrogenase Hamburg.

Deformability of erythrocytes of a patient with chronic nonspherocytic hemolytic anemia caused by a G-6-PD variant (G-6-PD Hamburg) in red cells was studied. The flow rate of erythrocytes from this patient through 5 mum polycarbonate sieves was higher than that of red cells from healthy adults. Even under oxidative stress in vitro, the deformability of erythrocytes of the patient was only slightly decreased. The residual hemoglobin content of red cell membranes (ghosts) from this patient was lower than that of ghosts from healthy adults and of ghosts prepared from comparable reticulocyte-rich blood withoug G-6-PD deficiency. In contrast to the low enzymatic activity of G-6-PD Hamburg in the hemolysate, a high activity of this enzyme could be demonstrated in the ghosts from the patient. In view of the flexibility of this patient's erythrocytes splenectomy is not to be recommended.

Adult↗
PubMed1977

[Pyrivate kinase deficiency. II. Biochemical studies (author's transl)].

Pyruvate kinase deficiency was studied biochemically in ten homozygous and seven heterozygous individuals who previously had been examined clinically and hematologically (see part I). In crude hemolysates some properties of the deficient enzymes were found to be altered. The pH optimum was shifted towards the alkaline range, and the thermal optimum was found between 17 and 27 degrees Cinstead of between 37 und 47 degrees C. The abnormal enzymes were much less stable than normal pyruvate Kinase (PK), and more susceptible to inhibition by adenosinetriphosphate. The affinity to adenosinediphosphate was normal in all cases whereas the affinity to phosphoenolpyruvate was either normal (two cases/, increased (two cases) or slightly decreased (six cases). Fructosediphosphate activated the abnormal enzymes by a factor of 1.5--18 and simultaneously transformed the sigmoidal affinity curve with phosphoenolpyruvate into the hyperbolic curve known for the normal enzyme. The consumption of glucose and the formation of lactate were higher in PK deficient erythrocytes than in normal cells but lower than in erythrocyte populations with similar reticulocyte counts. The formation of 2,3-diphosphoglycerate was markedly increased, whereas its breakdown was low. A close relation between the degree of reticulocytosis and the impairment of glucose metabolism was found. In patients with high reticulocyte counts, i.e. in the splenectomized patients, the highest concentrations of glucose-6-phosphate, phosphoenolpyruvate, 3-phosphoglycerate and 2,3-diphosphoglycerate as well as a high formation and a low breakdown of 2,3-diphosphoglycerate and a deficit in lactate formation were found. In heterozygotes, small increases of the concentration of glucose-6-phosphate, phosphoenolpyruvate and 3-phosphoglycerate were demonstrated. Our results support the conclusion that PK deficiency is mainly a disorder of the reticulocytes. Their metabolism grossly deteriorates within the venous sinuses of the spleen. Splenectomy improves the clinical course because this critical area of microcirculation with a highly unfavourable metabolic milieu is eliminated.

Anemia, Hemolytic, Congenital↗