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Biomedical subjects

D Birnbaum

Publications and source records attributed to D Birnbaum.

At least 325 records · Page 18Linked to original sources
PubMed1982

HLA cosmid clones show complete, widely spaced human class I genes with occasional clusters.

To understand the organization of the human leukocyte antigen (HLA) gene region and its relationship to the transplantation antigens expressed at the cell surface we have isolated clones containing HLA class I genes from a cosmid library (Grosveld et al., Gene 13, 227, 1981) constructed with the DNA from an individual of defined haplotype. Most of the cosmids contain a single HLA gene in 30-40 kb of human DNA, indicating that human class I genes are rather widely spaced; two contain two genes and one contains three. Most of these genes appear to be complete; the double or multiple genes are found in the same orientation. Differences in restriction maps are evident but some common features are observed in particular in the 5' half of these genes.

Bacteriophage lambda↗
PubMed1981

Differences in the cell binding affinity of a cross-reactive monoclonal anti-Ia alloantibody in mice of different H-2 haplotypes.

The analysis of an Ia specificity was performed in several H-2 haplotypes by evaluating the affinity of the binding to mouse spleen cells of a monoclonal anti-Ia alloantibody. We used the monoclonal antibody 10-2.16 (Oi et al., Curr. Top. Microbiol. Immunol. 1978. 81: 115.) which recognizes on I-A gene products a public specificity common to several H-2 haplotypes (f, ja, k, r, s and u). One parameter of the affinity (dissociation rate constant) was determined by the kinetics of the dissociation of cellbound 125 I-labeled Fab fragments in the presence of homologous antibodies. The dissociation rate constants thus obtained were different when the antibody reacted with cells from mice bearing different haplotypes and were similar for reactions with different mouse strains bearing the same haplotype. These data strongly suggest that the Ia public determinants involved are not strictly identical in different haplotypes, and support the concept that a serological cross-reaction does not necessarily mean structural identity between public antigenic determinants.

Animals↗
PubMed1981

[Aggregation and separability of the shikimate pathway enzymes in yeasts].

Gel filtration was employed to estimate the molecular weights and to determine possible physical aggregation of enzymes [5-dehydroquinate synthase (DHQ synthase), 5-dehydroquinase (DHQase, EC 4.2.1.10), shikimate: NADP oxidoreductase (EC 1.1.1.25), shikimate kinase (EC 2.7.1.71), 3-enolpyruvylshikimate 5-phosphate synthase (EPSP synthase)] in the shikimate pathway in eleven species of yeasts. The five enzymes were not aggregated in extracts of Hansenula henricii, H. fabianii, H. anomala, Candida utilis, Pichia guilliermondii, and Lodderomyces elongisporus. Two enzymes (DHQase and shikimate:NADP oxidoreductase) were not separable by this method and by ion exchange chromatography, and we conclude that they exist as an aggregate in these yeasts. Evidence is presented for an enzyme aggregate containing five activities, with a molecular weight of approximately 280,000 in Rhodosporidium spaerocarpum, Rh. toruloides, Rhodotorula rubra, Saccharomycopsis lipolytica, and Saccharomyces cerevisiae. Similarities between the enzymes in the shikimate pathway of plants, bacteria, and other fungi and those of investigated yeasts are discussed.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1981

[General control of amino acid biosynthesis in Hansenula henricii].

The general control of amino acid biosynthesis was investigated in Hansenula henricii. By limitation for single amino acids in wild type strain and mutants no derepression of enzymes was caused. In prototrophic revertants however, obtained from auxotrophic mutants (his, pdx) enzyme activities were 2 - 17 times higher than in the wild type. In these revertants enzymes of the biosynthetic pathways for tryptophan, phenylalanine, tyrosine, arginine, histidine, cysteine, methionine, asparagine, threonine, and isoleucine were derepressed. The amino acid pool pattern of the revertants if completely different from that in the wild type strain. A discussion of possible mechanisms of general control of amino acid biosynthesis in H. henricii is presented.

Amino Acids↗
PubMed1980

[Serological study of Ia antigens determined at the I-A and I-E sub-regions of the H-E complex in the H-2 complex of mice].

Immune serum B10.S (7R) anti-B10.S (9R)(anti I-JEkCd) contained as expected an anti-Ia7 antibody. A series of weaker but reproducible extra-reactions might recognize Ia3 specificity coded at the I-A subregion of the H-2 complex. Results with recombinant haplotypes confirmed this mapping. Such a reactivity could be interpreted as an interlocus cross-reaction (I-E/I-A) since the immunization was induced against an I-E subregion product. Another interpretation was possible: the immune serum would thus contain an antibody recognizing Ia7 (on the E alpha k Ia chain) and another antibody recognizing an antigenic determinant carried by the E beta k Ia chain. The latter antibody might recognize by cross-reaction as specificity carried by the A beta chain of various haplotypes (H-2b,k,q).

Animals↗
PubMed1980

Excretion of peptides by Rhodosporidium torudoides.

Strains of Rhodospordium torloides produced two peptides into the culture filtrate. Peptide I contained 6 amino acids and peptide II contained 5 amino acids. The peptides however, are, not homologous to the alpha-factor, and become assimilated at a later phase of growth.

Amino Acids↗
PubMed1979

[Effects of bacterial peritonitis on the low-pressure system in man].

The effective compliance (C) of the "low-pressure system" has been measured in ten patients with bacterial peritonitis by means of plotting pressure and volume on the first postoperative day (deltaV = 500 ml/10 min). The value of C is decreased in one group of patients, while it increases to as much as five times that of "normal patients" in the other. The cause might be a summation effect of hypovolemia, blood volume shift from intra- to extrathoracic space, and endotoxin reaction on the tone of vascular smooth muscle. The augmentation of the intravascular volume results in an increase of portal venous pressure, which is less than central venous pressure. Splanchnic pooling through increased vascular resistance does not appear.

Bacterial Infections↗
PubMed1979

Effect of concanavalin A on lysosomal enzyme content of Hela cells.

Precoating Hela cells with concanavalin A (Con A) induces a decrease of lysosomal enzyme intracellular content, and correlatively increases the amount of these enzymes in the culture medium. Possible mechanisms of the lectin effect are discussed in relation to the hypothesis of the secretion-endocytosis cycle of lysosomal enzymes.

Concanavalin A↗
PubMed1979

[Varied circulatory effects after rapid infusion of hydroxyethyl starch, dextran 60 and blood in the postoperative patient].

The acute hemodynamic effects which occur after a quick infusion (500 ml per 10 minutes) of hydroxyethyl starch, dextran 60 or autologous blood with identical hematocrit were studied in three groups of 10 patients each on the first day after laparotomy. If blood is infused there is only a moderate increase of the total perfusion (+18%) observed, however hydroxyethyl starch or dextran 60 infusions result in a striking increase of the cardiac output (+34%, +44%, respectively). There is no significant difference among the latter two groups. Thus, hydroxyethyl starch as well as dextran 60 can be considered as a potent volume substitute, if an acute effectiveness is wanted.

Blood Transfusion, Autologous↗