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Biomedical subjects

R Berger

Publications and source records attributed to R Berger.

At least 721 records · Page 40Linked to original sources

An international reference typing for Ch and Rg determinants on rare human C4 allotypes.

Red cells, serum and plasma samples of 20 individuals, selected for their C4 allotypes, were distributed from Bonn to five laboratories, for investigation of their Chido (Ch) and Rodgers (Rg) determinants. One anti-Ch (M.H.) and one anti-Rg(Prest.) were distributed, but the individual laboratories also used their own reagents and their own typing methods. There was general agreement in interpretation of the majority of samples. Partial inhibition for Ch and Rg was detected. Two samples gave anomalous results; one sample with C4 A1,3 BQO, QO had Ch determinants on the red cells and in plasma (partial inhibition), and another sample with C4 A3,4 B5, QO apparently lacked Ch determinants on the red cells and in plasma. Heterogeneity of anti-Ch and anti-Rg was suggested in testing red cells, perhaps, reflecting a quantitative effect. This heterogeneity was confirmed by inhibition studies. The capacity of some reagents to detect partial inhibition probably reflects qualitative as well as quantitative differences.

Alleles↗

Successful treatment of severe carbamyl phosphate synthetase I deficiency.

We describe a girl with neonatal hyperammonaemia due to carbamyl phosphate synthetase I deficiency. Treatment consisted of protein restriction from the second day of life. Sodium benzoate was given for three weeks after birth and again from 7 months of age together with sodium phenylacetate to improve protein tolerance. Growth and development are normal at 15 months of age.

Amino Acid Metabolism, Inborn Errors↗

Lactate as a cerebral metabolic fuel for glucose-6-phosphatase deficient children.

The main substrates for brain energy metabolism were measured in blood samples taken from the carotid artery and the internal jugular bulb of four children with glycogen storage disease caused by deficiency of glucose-6-phosphatase. Multiple paired arterial and venous blood samples were analyzed for glucose, lactate, pyruvate, D-beta-hydroxybutyrate, acetoacetate, glycerol and O2, and the arteriovenous differences of the concentrations were calculated. In the first three patients the substrates were measured in two successive conditions with lower and higher glucose-intake, respectively, inducing reciprocally higher and lower concentrations of blood lactate. In the fourth patient medium chain triglycerides were administered simultaneously with the glucose-containing gastric drip feeding. Lactate appeared to be taken up significantly. It consumed, if completely oxidized, between 40-50% of the total O2 uptake in most cases. Only once in one patient the uptake of lactate switched to its release, when the blood lactate level decreased to normal. D-beta-hydroxybutyrate and acetoacetate arteriovenous (A-V) differences were small to negligible and these ketone bodies, therefore, did not contribute substantially to the brain's energy expenditure. Glycerol was not metabolized by the brain. Lactate thus appeared to be the second brain fuel next to glucose. It may protect the brain against fuel depletion in case of hypoglycemia.

Brain↗

The dietary treatment of children with type I glycogen storage disease with slow release carbohydrate.

The effect of ingestion of uncooked cornstarch (2 g/kg body weight) in water, uncooked starch (1 g/kg) added to a meal, and glucose (2 g/kg) in water, was studied in eight patients with type IA glycogen storage disease (GSD) and one patient with type IB GSD. Blood glucose concentrations were determined at 30-min intervals during each tolerance test; blood lactate, blood insulin, and expiratory hydrogen were determined at 60-min intervals. The glucose levels remained in the normal range (greater than or equal to 1.8 mM) during approximately 6.5-9.0 h, 3.5-6.5 h, and 2.25-4.0 h during the three tolerance tests, respectively. The lactate levels differed markedly for the different tests per patient, and for the same type of test between the patients. Blood insulin concentrations after starch administration did not exceed values of 50 mU/liter above fasting levels and were markedly lower than those after glucose administration (maximum levels of 280 mU/liter). The expiratory hydrogen excretion did not increase or only slightly increased after cornstarch administration (less than 20 ppm).

Adolescent↗

[Is there a functional equivalence between abnormalities of the long arm of chromosome 1 and the presence of Epstein-Barr virus in continuous lines of Burkitt's lymphoma?].

Chromosome 1 long arm abnormalities (translocations, partial of complete trisomies) are non-randomly but inconstantly associated with specific translocations involving chromosomes 8, and 2, 14 or 22 in Burkitt's lymphomas and leukemias. All nine Burkitt's lymphoma cell lines not associated with Epstein-Barr virus (EBV) were shown to exhibit a chromosome 1 long arm abnormality and were present in only 3 out of 18 EBV positive cell lines. Bands 1q23 - 1q24 were involved in EBV-negative cell lines. It was thus hypothesised that genetic information resembling that included in viral genome exists on chromosome 1 long arm. This hypothesis implies new possible aspects of relationship between Burkitt's cell line proliferation and EBV.

Burkitt Lymphoma↗

[Acute promyelocytic leukemia: retrospective study of 119 patients treated with daunorubicin].

A retrospective study of 119 patients with acute promyelocytic leukemia (APL) treated with similar DNR containing regimens in reported. Antecedent of radiation exposure or cancer was found in 10 patients. At presentation hyperleucocytosis was rare (13/119 greater than 30 000/microliter); variant form was identified in 5 cases. Organomegaly was uncommon and severe metabolic abnormality was never noted at presentation. DIC was observed in 75% of pts; t (15;17) was confirmed in 25/30 pts. Complete remission (CR) rates have increased from 43% to 76% on account of improvement of supportive therapy with adequate DIC management. Addition of ARA C did not improve CR rates (72%). Surprisingly duration of CR seems related to maintenance therapy as 11/26 pts receiving 6 MP-MTX maintenance regimen were long-term survivors as compared to 1/34 comparable pts receiving cyclic monthly courses of chemotherapy.

Adolescent↗

[Stereotyped chromosome abnormalities in human leukemia and lymphoma].

That chromosomal abnormalities in leukaemias and lymphomas are not non-randomly distributed has been demonstrated by banding techniques. Abnormalities characteristic of a given type of proliferation are described. The chromosomal breakpoints corresponding to these changes are located close to the sequences encoding for cellular oncogens (c-onc), which justifies the growing interest in the cytogenetic study of malignant cells.

Burkitt Lymphoma↗

[Thrombocythemia with Philadelphia chromosome. Secondary appearance of chronic myeloid leukemia].

The finding of a Philadelphia chromosome in a case of apparently primary thrombocythaemia should change the diagnosis for that of chronic myeloid leukaemia. This theoretical view is supported by the case reported here, where a Philadelphia-chromosome was detected in the bone marrow cells of a patient with severe thrombocythaemia; a typical myeloid leukaemia developed 21 months after the onset of the disease; survival was of short duration.

Adult↗

Biochemical studies on the enzymatic deficiencies in hereditary tyrosinemia.

Experiments are described on the effects of succinylacetone and fumarylacetoacetate on delta-aminolevulinic acid dehydratase, methionine adenosyltransferase and p-OH-phenylpyruvate dioxygenase. delta-Aminolevulinic acid dehydratase from human erythrocytes is inhibited non-competitively by succinylacetone (Ki 0.03 mumol/l) and by fumarylacetoacetate (Ki 0.06 mumol/l). The inhibition by succinylacetone is not prevented by dithiothreitol, but the inhibition by fumarylacetoacetate is not observed if dithiothreitol is present. Methionine adenosyltransferase, partially purified from rabbit liver, is not inhibited by succinylacetone but is inhibited by fumarylacetoacetate: 69% inhibition is observed at 1 mmol/l. Human liver p-OH-phenylpyruvate dioxygenase is not inhibited by succinylacetone or fumarylacetoacetate. It is concluded that secondary enzyme deficiencies observed in hereditary tyrosinemia (delta-aminolevulinic acid dehydratase, methionine adenosyl transferase) are the result of inhibition by succinylacetone and fumarylacetoacetate, accumulating as a result of a primary deficiency of fumarylacetoacetase.

4-Hydroxyphenylpyruvate Dioxygenase↗

Location of immunodominant antigenic determinants on fragments of the tick-borne encephalitis virus glycoprotein: evidence for two different mechanisms by which antibodies mediate neutralization and hemagglutination inhibition.

A model showing the topological distribution, functions, and serological specificities of eight distinct, monoclonal antibody-defined epitopes on the tick-borne encephalitis (TBE) virus glycoprotein has been presented in a previous publication (F. X. Heinz, R. Berger, W. Tuma, and Ch. Kunz (1983). Virology 126, 525-537.) In the present report the influence of conformational change, chemical modification, and fragmentation on the antigenic reactivity of each epitope has been analyzed by the use of blocking enzyme immunoassays and "Western blotting." One of the two major antigenic domains (A), composed of three different epitopes, completely lost its antigenicity upon incubation at pH 5.0 or by treatment with guanidine-HCl/urea, SDS, reduction and carboxymethylation, as well as by proteolytic (trypsin, alpha-chymotrypsin, thermolysin) and chemical (CNBr) fragmentation. The second major antigenic domain (B), however, defined by four distinct monoclonal antibodies, three of which are hemagglutination (HA)-inhibiting, neutralizing, and protective, was shown to be resistant to low pH, guanidine-HCl/urea treatment, and proteolytic cleavage of the native protein. Also, polyclonal immune sera from mice and rabbits contained antibody populations reactive with antigenic determinants which are resistant and others which are sensitive to conformational change and fragmentation. Glycoprotein fragments with molecular weights of about 9000, generated by proteolysis of the native protein, were immunoreactive with neutralizing and protective monoclonal antibodies (defining domain B) as well as with a polyclonal mouse immune serum. Thus, these fragments appear to contain antigenic determinants which are immunodominant on the native protein and play an important role in the induction of a protective immune response against TBE virus. In addition, these results show that antibody binding to antigenic domains which are topologically and structurally completely unrelated may result in neutralization and/or HA inhibition. As the presence of two receptor-binding sites is unlikely, different effector mechanisms may account for the effects of these antibodies. The antigenic reactivity of domain A is sensitive to the same treatments which also inactivate HA activity of TBE virus, whereas domain B is resistant. These treatments include a change of domain A induced by incubation at slightly acidic pH which also results in inactivation of virus infectivity. Antibodies to domain A therefore presumably block viral activities by direct binding at or near the putative receptor-binding site whereas antibodies to domain B may cause loss of biological activities by inducing a conformational change of the receptor-binding site.

Antibodies, Monoclonal↗

Malignant myeloblastic transformation of murine long-term bone marrow cultures by F-MuLV: in vitro reproduction of a long-term leukemogenesis, and investigation of preleukemic events.

A Friend helper virus I-5(F-MuLV) which induces myeloblastic leukemias in mice after a latency of several months, was used to infect long-term bone marrow cultures. From 48 to 71 weeks after in vitro infection, 4/14 cultures gave rise to transplantable malignant myeloblastic cells. These cells were shown to genuinely result from as in vitro transformation of virus-infected normal bone marrow cells. The in vitro transformation reproduced the course of the in vivo disease. It provided unique material for in vitro investigation of the preleukemic stages of long-term leukemogenesis. Successive cellular events were: (1) freezing of the normal myelomonocytic differentiation process; (2) change from factor-dependent to an autonomous growth; (3) acquisition of in vivo tumorigenicity.

Animals↗

Urinary excretion of deuterated metabolites in patients with tyrosinemia type I after oral loading with deuterated L-tyrosine.

1. The metabolic fate of orally given deuterated L-tyrosine, 50 mg/kg body weight, was investigated in seven patients with tyrosinemia type I in order to obtain evidence that the primary defect is at the level of fumarylacetoacetase. 2. The absence of fumarylacetoacetase could be proved in liver biopsy specimens obtained from four patients. 3. All patients excreted deuterated succinylacetoacetate and deuterated succinylacetone was detected in six out of seven. The total amount of these compounds was rather low; maximal 8.3% of the dose. The peak of the excretion occurred 3-6 h after loading, indicating an endogenous formation of the metabolites. 4. All patients excreted deuterated 4-hydroxyphenyl acids, probably reflecting secondary 4-hydroxyphenylpyruvate dioxygenase deficiency connected with liver damage. 5. No evidence for other secondary routes of tyrosine metabolism was found.

4-Hydroxyphenylpyruvate Dioxygenase↗

[Fanconi's anemia. Incidence of its development into leukemia].

Fanconi's anaemia (FA) is a hereditary disease transmitted in a recessive manner, characterized by congenital malformations and bone marrow aplasia. A high rate of chromosome breakage is observed in mitoses of cultured blood cells, but the caryotypes are normal. Forty-four patients (27 boys and 17 girls) were followed in the same department between 1962 and 1976. Most were treated with androgens, sometimes combined with corticosteroids. Nine patients died of acute granuloblastic leukaemia, with more than 25% bone marrow blasts; in three of these, cytogenetic examination showed clonal anomalies. Five patients were in preleukaemic state with non-blastic bone marrow; 4 showed clonal anomalies and 2 of these died of aplasia; the 5th patient had gross liver and spleen enlargement and died of haemorrhage. Among the 30 remaining patients 12 are still alive and 18 died of cerebral haemorrhage (7), hepatic failure (3), cardiac failure (1), pancreatitis (1), septicaemia (2) or graft-versus-host reaction after bone marrow transplantation. One patient transplanted 4 years ago has complete chimerism and is still alive without treatment. The incidence of leukaemic or preleukaemic state in this series was 30%, while no case of leukaemia was observed in 200 patients with acquired aplastic anaemia. Neither parents norsibship had leukaemia. Androgen treatment apparently did not increase the risk of leukaemia which developed within 1 to 13 years (mean = 5 years) of the diagnosis, was preceded by a 2 1/2 year long preleukaemic state with clonal chromosomal anamolies and invariably was of the granulocytic type. None of the patients developed cancer. The median survival in this series was 4 1/2 years.

Acute Disease↗