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L E Walker

Publications and source records attributed to L E Walker.

48 records · Page 3Linked to original sources
PubMed1981

Biochemical comparison of H-2K antigen isolated from C3HfB/HeN and C3H/HeN mice.

The H-2K glycoproteins were isolated from spleen cells of C3H/HeN and C3HfB/Hen mice and compared by tryptic peptide mapping techniques. The two antigens were found to be very similar in that more than 90 percent of detectable peptides appeared identical. However, two lysine-containing peptide present in tryptic digests of H-2K antigens isolated from C3H mice were absent from tryptic digests of H-2K antigens isolated from C3Hf mice. This was probably not the result of altered glucosylation since neuramindase digestion demonstrated that the disparate peptides were not glycopeptides but most probably resulted from substitution of one or two amino acids in the H-2K molecule of C3HfB/HeN mice. These differences were small but significant and demonstrated that H-2Kk (C3H) and H-2Kkv1 (C3Hf) antigens are structurally distinct. This is compatible with the observed reciprocal skin-graft rejection, MLR, and generation of cytotoxic T lymphocytes between the two strains. The significance of this finding in conjunction with what is known about properties of 1-ethyl-1-nitrosourea-induced tumors of C3Hf mice is discussed.

Animals↗
PubMed1981

The free and the beta 2-microglobulin-associated heavy chains of HLA-A, B alloantigens share the antigenic determinant recognized by the monoclonal antibody Q1/28.

Serological and immunochemical assays have shown that the monoclonal antibody Q1/28 recognizes an antigenic determinant which is expressed on the heavy chain of subsets of HLA-A, B antigens and is distinct from those defining the serological polymorphism of this system. Association of the HLA-A, B heavy chain with beta 2-microglobulin is not required for expression of the antigenic determinant recognized by the monoclonal antibody Q1/28, since this antibody can immunoprecipitate a 45 000 m.w. component from radiolabeled lymphoid-cell glycoproteins immunodepleted with either an anti-human beta 2-microglobulin xenoantiserum or the MoAb W6/32 to framework determinants of HLA-A, B, C antigens. Furthermore, the MoAb Q1/28 can immunoprecipitate a 45 000 m.w. component from an NP40 lysate of radiolabeled Daudi cells, which lack the genetic information for beta 2-microglobulin. The determinant recognized by the MoAb Q1/28 is relatively resistant to denaturing treatments and does not appear to be carbohydrate in nature. The MoAb Q1/28 is the first example of an antibody which recognizes an antigenic determinant expressed on both the beta 2-microglobulin-associated and free HLA-A, B heavy chains.

Antibodies, Monoclonal↗
PubMed1980

Purification of immunologically functional subsets of human Ia-like antigens on a monoclonal antibody (Q5/13) immunoadsorbent.

Serologic and immunochemical asays have shown that the monoclonal antibody Q5/13 recognizes an antigenic determinant expressed on a subset of human Ia-like antigens. Testing with a panel of HLA typed B lymphoid cells has shown that this determinant is different from those defining the serologic polymorphism of HLA-DR antigens. The monoclonal antibody Q5/13 has been used to purify subsets of human Ia-like antigens, which are immunologically functional. These reagents should facilitate the characterization of structural and functional properties of human Ia-like antigens.

Antibodies↗
PubMed1978

Murine Ia and human DR antigens: homology of amino-terminal sequences.

Murine Ia and human DR antigens were isolated and purified by immunoprecipitation and sodium dodecyl sulfate/polyacrylamide gel electrophoresis with allo- and xenoantisera, respectively. The I-A subregion antigen consists of two chains, designated Aalpha and Abeta, with molecular weights of 35,000 and 26,000, respectively. The I-C subregion antigen likewise consists of two chains, designated Calpha and Cbeta, with molecular weights of 32,000 and 29,000, respectively. Under nonreducing conditions, the Cbeta chain migrates appreciably more rapidly on sodium dodecyl sulfate/polyacrylamide gels than the reduced Cbeta chain, reflecting the presence of an intrachain disulfide bond. The human DR antigen is also a two-chain unit and contains DRalpha and DRbeta components with molecular weights of 34,000 and 28,000, respectively. The DRbeta chain migrates more rapidly before reduction than afterward, like the murine Cbeta chain. The DRbeta and Cbeta chains are also strikingly homologous if a single amino acid shift is imposed on one of those chains. Thus, human DR antigens strongly resemble the murine I-C subregion antigens.

Amino Acid Sequence↗
PubMed1975

Blood availability for the trauma patient-autotransfusion.

Recovery of intrathoracic and intraperitoneal blood and reinfusion by autotransfusion has been demonstrated to be safe and practical in selected trauma patients. Autotransfusion is ideally applicable to the trauma patient in whom replacement of six or fewer units of blood is required. In addition, autotransfusion provides readily available blood for patients with unusual blood types and for those in whom multiple transfusions may rapidly deplete available stores. The properties of an ideal autotransfusion device include rapid assembly, relatively low cost, ease of operation, in-line filtration, minimized air blood interface, simplified anticoagulation, and safety from air embolism and coagulopathies.

Bilirubin↗
PubMed1975

Effects of exogenous ATP on short-circuit current and potential difference of the isolated frog skin.

The addition of ATP (10(-3) M = final concentration) to the bathing medium of either side of the isolated frog skin resulted in parallel increases in potential difference and short-circuit current. Reductions in these electrical parameters induced by anaerobic conditions and sodium azide could be partially reversed by exogenous ATP. The response is apparently not mediated by cyclic adenylic acid, as it was not enhanced by theophylline. Ouabain failed to reduce rates of phosphate liberation induced by ATP, although potential difference and short-circuit current were reduced.

Adenosine Monophosphate↗