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Biomedical subjects

M W Shaw

Publications and source records attributed to M W Shaw.

8 recordsLinked to original sources

Antibody--antigen complex stimulated lysis of non-sensitized sheep red cells by human lymphocytes. I. Requirements for IgG complexes.

IgG antibody--antigen complexes stimulated lysis of non-sensitized sheep erythrocytes (SRBC) by normal human peripheral blood lymphocytes (PBL). Heat-aggregated human IgG, rabbit IgG-ovalbumin complexes and rabbit IgG-sensitized ox erythrocytes (ORBC) were effective in the induction of SRBC lysis by PBL. However, IgM-sensitized ORBC and IgM-complement-sensitized ORBC were ineffective. As only SRBC and not ORBC or chicken erythrocytes (CRBC) were lysed under identical experimental conditions, it is conceivable that the SRBC receptor present on the T cell is involved. Furthermore, 45% inhibition of lysis was obtained by pretreating the effector cells with anti-human thymocyte globulin (ATG) and complete inhibition was obtained by adding SRBC stroma to the reaction mixture. The requirement for the inclusion of IgG complexes and the absence of specific anti-target cell antibody distinguish this reaction from natural cell-mediated cytotoxicity and antibody-dependent cell-mediated cytotoxicity (ADCC). Immune killer T cells would not appear to be responsible as eight different donors were used and none of these were cytotoxic to SRBC in the absence of IgG complexes. The induction of this cytotoxic reaction appears to require the recognition and interaction by the effector cells of two separate molecular entities, i.e. the SRBC membrane by the T cell and the IgG Fc region by an IgG-Fc receptor-bearing cell.

Animals

Isolation and characterization of cytoplasmic inclusions from influenza A virus-infected cells.

Influenza A viruses induce the accumulation of electron-dense inclusions in the cytoplasm of infected cells during the latter stages of the replication cycle. Cell fractionation studies showed that these inclusions could be recovered in subcellular fractions containing ribosomes and polysomes. Isolation of these inclusions was accomplished by procedures involving RNase treatment of these fractions followed by repurification, or by fluorocarbon extraction and gradient centrifugation. Electron microscopy indicated that the isolated inclusions exhibited a major periodicity of approximately 8 nm with minor periodicities of approximately 4 nm. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the influenza virus coded nonstructural protein was the only protein component present in isolated inclusions.

Amino Acids

Antibody-dependent cell-mediated cytotoxicity in the Moloney sarcoma virus system: differential activity of IgG and IgM with different subpopulations of lymphocytes.

Antibody-dependent cell-mediated cytotoxicity in the Moloney sarcoma virus (MSV) system was evaluated in terms of the differential ability of IgG and IgM from MSV regressor animals to induce cytotoxicity by lymphocytes from lymph node, spleen, and thymus. The cell-mediated cytotoxicity induced by both IgM and IgG was specific for target possessing the appropriate virally determined cell surface antigen(s). IgM induced cytotoxicity by lymphocytes from all the organs tested. However, differences in magnitude and efficiency were revealed. Lymph node cells and thymocytes were most efficient against IgM-coated target cells. Against IgG-sensitized target cells, spleen and lymph node cells were about equally active, but thymocytes were inactive. Cortisone treatment of the donors of effector cells revealed that the cortisone resistant subpopulation of thymocytes, 2 days after cortisone injection, exhibited an increased cytotoxicity against target cells treated with unfractionated antiserum and its IgM fraction. This subpopulation of thymocytes was also cytotoxic against IgG-coated target cells. At 12 days after cortisone injection, the repopulated thymus showed little change in activity, compared to control thymus, against antibody-coated target cells.

Animals

Genetically defective children: emerging legal considerations.

Despite modern medical advances, births of genetically defective children still occur. The author outlines the problem of genetic disease, and describes the medical and legal advances that now make possible a reduction in its incidence. Then she cites--and briefly comments upon--some court cases brought by parents of genetically defective children against their physicians for allegedly failing to predict or to diagnose genetic defects in those children in time for the parents to exercise any procreative options such as sterilization, contraception, or abortion. In addition, the author speculates on various questions that may arise in future litigation in this area--among them, the question of whether or not courts someday will endow genetically defective children with a cause of action against their parents for bringing them into the world.

Child

Polymporphism of human C-band heterochromatin. II. Family studies with suggestive evidence for somatic crossing over.

An analysis of the inherited pattern of C-band heterochromatin has been made in five pedigrees containing a total of 33 offspring that were available for analysis. The majority of variants were found to be inherited; however, at least seven of the 99 variants were not present in either parent, and an additional seven differed from the parental variant by either a morphological change or the appearance of mosaicism. It is believed that the polymorphism of human constitutive heterochromatin arises from a mismatching of the repetitive DNA sequences contained in these regions with subsequent unequal crossing over. Further, the observed mosaic patterns provide suggestive evidence that such an event occurs in somatic cells as well as during meiosis.

Blood Group Antigens