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Biomedical subjects

R Lieberman

Publications and source records attributed to R Lieberman.

At least 127 records · Page 7Linked to original sources
PubMed1972

H-2-linked immune response (Ir) genes. Independent loci for Ir-IgG and Ir-IgA genes.

Two H-2-linked autosomal dominant immune response (Ir) genes Ir-IgG and Ir-IgA were demonstrated to be at separate loci. Ir-IgG controls the immune response to IgG (gamma2a) myeloma proteins and Ir-IgA the immune response to IgA meyloma proteins. Both genes are associated with the H-2K region specificities of the H-2 chromosome, specifically Ir-IgG with H-2(b) and Ir-IgA with H-2(a). Different recombinants derived from H-2(a)/H-2(b) crossovers were examined for their immune responsiveness to BALB/c IgG (gamma2a) and IgA myeloma proteins. B10 (H-2(b)) parental type responded only to IgG; B10.A (H-2(a)) responded only to IgA. All the recombinants except for B10.A (4R) responded to either IgG or IgA. B10.A (4R), however, responded to both IgG and IgA. This indicated that the crossover event giving rise to B10.A (4R) occurred between the Ir-IgG and Ir-IgA loci.

Animals↗
PubMed1972

Genetic factors controlling anti-sheep erythrocyte antibody response and immunoglobulin synthesis in backcross and F2 progeny of mice genetically selected for "high" or "low" antibody synthesis.

Agglutinin responses to sheep erythrocytes and immunoglobulin heavy chain phenotypes determined in F(1), F(2), and backcross progeny of mice genetically selected for high and low antibody synthesis indicated that an immune response gene for sheep erythrocytes is linked to the immunoglobulin heavy chain allotype. Mice homozygous for the phenotype of the high line had significantly higher titers than mice homozygous for the phenotype of the low line. An association was also observed in some progeny of the backcross of the F(1) generation with the low line. However, the control of the immune response was clearly multigenic since heterozygous mice of the same phenotype (2/3, 5) resulting from the two backcrosses (high and low) had very different immune responses. Immunoglobulin levels in the same progeny showed no linkage to the immunoglobulin allotype but a rather simple pattern of inheritance.

Animals↗
PubMed1972

Mechanism of antidiuretic effect of beta adrenergic stimulation.

The effect of beta adrenergic stimulation on renal-diluting capacity was examined in the dog. Beta adrenergic stimulation with intravenous isoproterenol significantly increased urinary osmolality (U(Osm)) and decreased free water clearance (C(H2O)), and these effects were rapidly reversible with cessation of the infusion. This antidiuretic effect of systemic beta adrenergic stimulation was comparable in innervated and denervated kidneys and was not associated with alterations in glomerular filtration rate or renal vascular resistance. Renal perfusion pressure was maintained constant in all of the experiments. The same dose of isoproterenol, which produced the antidiuretic effect and markedly stimulated cardiac beta adrenergic receptors when infused intravenously, was not found either to increase U(Osm) or to decrease C(H2O) when infused directly into the renal artery. Removal of the source of production and release of antidiuretic hormone (ADH) was, however, found to abolish the effect of intravenous isoproterenol on U(Osm). A small effect on C(H2O) persisted and appeared to be related to an increase in arterial hematocrit. Thus, the results of the study exclude a major role of alterations in renal hemodynamics and renal innervation in the antidiuretic response to beta adrenergic stimulation with isoproterenol. They also provide no support for the hypothesis that beta adrenergic stimulation may directly alter the water permeability of the renal tubular epithelium. Rather the results suggest that the primary mechanism of the antidiuretic effect of beta adrenergic stimulation involves the integrity of the hypothalamoneurohypophyial system and the release of ADH.

Animals↗
PubMed1971

Association of H-2 types with genetic control of immune responsiveness to IgA allotypes in the mouse.

The immune response to BALB/c IgA myeloma proteins (Ir-IgA) was determined in mice of various H-2 types from five different linkage groups of immunoglobulin heavy chains (IgC(H)). Antisera were examined for antibodies to idiotypic (Fab) and allotypic (Fc) specificities. No immune response to IgA myeloma proteins was found in mice with the same linkage group as BALB/c but with different H-2 alleles. In mice with immunoglobulin heavy chains that are different than BALB/c, a high immune response to IgA myeloma proteins was found in H-2 types a, k, r, and s; a low response is associated with H-2(b) and H-2(d) types. Chromosome mapping of Ir-IgA genes in the H-2 locus indicate that they are on the right side of the chromosome, to the right of the Ss locus. Ir-IgA genes are controlled by dominant autosomal genes.

Animals↗
PubMed1970

Common individual antigenic determinants in five of eight BALB-c IgA myeloma proteins that bind phosphoryl choline.

Eight IgA myeloma proteins derived from independently induced plasma-cytomas in genetically similar inbred BALB/c mice are functionally related by their binding of phosphoryl choline-containing antigens (Pneumococcus C polysaccharide or Lactobacillus antigen). Each protein resembles a single species of immunoglobulin in antibody. The proteins are characterized by highly sensitive myeloma-specific antisera prepared by immunizing mice of other inbred strains with the BALB/c myeloma proteins. Individual or myeloma-specific determinants located on Fab fragments were found on three of the proteins that were unique for that protein and did not react with any other IgA protein among over 70 tested. Remarkably, five of the proteins shared two common myeloma-specific determinants which were specific for this group of five proteins. These results suggest that the five functionally and genetically related proteins sharing the same myeloma-specific determinants might also be structurally similar.

Animals↗
PubMed1970

Serum concentrations and allotypes of immunoglobulins in two lines of mice genetically selected for "high" or "low" antibody synthesis.

Random-bred Swiss mice were selectively bred for 16 generations; selection was based on their agglutinin response to sheep and pigeon erythrocytes to produce a high and a low responder line. The serum levels of individual immunoglobulins differed significantly in these two lines before immunization. The differences in the levels of immunoglobulins were much more marked after immunization with pigeon or sheep erythrocytes. Greater differences between the two lines were noted in IgM and IgG levels than in IgA. Another remarkable finding was the presence of different immunoglobulin phenotypes in the two lines. The high responders were homozygous or heterozygous for heavy-chain linkage groups found separately in the prototype BALB/c and C57BL inbred strains. The low responders were homozygous for a heavy-chain linkage group not present in bred mice in the United States, but observed as a recombinant type among wild mice probably representing a crossover between the heavy-chain linkage groups of the prototype DBA/2 and NH inbred mice.

Animals↗
PubMed1969

Crossing over between genes in the immunoglobulin heavy chain linkage group of the mouse.

Immunoglobulin heavy chain genes were found in wild mice (Mus musculus) that could best be explained as recombinants of immunoglobulin genotypes. In wild mice from Kitty Hawk, N. C., two new heavy chain linkage groups, G(3,5,7,8)H(9,11)F(f)A(-) and G(3,5,8)H(9,11)F(f)A(-), were found, each of which genetically controls both the 3 and 5 distinct immunoglobulin determinants. In inbred strains the 3 and 5 determinants are found independently. The new heavy chain allotype G(3,5,7,8)H(9,11)F(f)A(-) probably arose from a homologous (intragenic) cross-over between G(3,8)H(9,11)F(f)A(-) and G(5,7,8)H(9,11)F(f)A(14) heavy chain linkage groups. It was suggested that genes controlling G(3,8)G(5,7,8), G(3,5,8), and G(3,5,7,8) are alleles. Another homozygous wild mouse (Kyushu, Japan) showed a new heavy chain allotype, (2)G(1,6,7,8)H(9,16)F(s)A(15). The 2 and G(1,6,7,8) determinants are also separated in inbred strains. The 2 determinant in inbred mice is not on the gammaF, gammaH, or gammaA heavy chain and is probably on a gammaG or gammaG-like immunoglobulin heavy chain. Papain digestion of serum from the Kyushu mouse showed two electrophoretically different Fc fragments, one carrying the G(1,6,7,8) and the other the 2 determinant. The new heavy chain allotype, (2)G(1,6,7,8)H(9,16)F(s)A(15), of the Kyushu wild mouse probably arose from a nonhomologous (unequal) cross over between (2)G(-)H(9,16)F(s)A(15) and G(1,6,7,8)H(9,11)F(f)A(12,13,14) heavy chain linkage groups. The linkage group of the Kyushu wild mouse has at least five heavy chain genes, while that of the inbred mice has four.

Animals↗
PubMed1968

2-chain immunoglobulin A molecules: abnormal or normal intermediates in synthesis.

Immunoglobulin A (gammaA) myeloma proteins secreted by plasma-cell tumors of mice are of two types, a common four-chain molecule and a rare two-chain (3.9S) molecule. The close similarity between two-chain gammaA molecules and four-chain gammaA molecules and their polymers is demonstrated in tryptic peptide maps of isolated polypeptide chains and by precipitin reactions with rabbit antiserums to gammaA immzunoglobulins. However, a difference between these two types is distinguishable with homologous antiserums. Homologous antiserums to two-chain gammaA immunoglobulins are specific and do not cross-react with four-chain gammaA immutnoglobulins.

Animals↗