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Biomedical subjects

R C Williams

Publications and source records attributed to R C Williams.

At least 541 records · Page 30Linked to original sources

Peripheral blood lymphocyte cell surface markers during the course of systemic lupus erythematosus.

Peripheral blood lymphocytes from 23 patients with active systemic lupus erythematosus (SLE) were serially studied. Changes in bone marrow-derived lymphocytes (B cells), as measured by surface Ig receptors and C3 receptors, and in thymus-derived cells (T cells) measured by rabbit T-cell-specific antiserum and E-binding techniques, were correlated with fluctuations in clinical disease activity and treatment. In normal controls B- and T-cell percentages remained relatively stable, although the situation in SLE was much more labile. A relative and absolute decrease in T lymphocytes and cells bearing a receptor for C3 was found in active lupus. Absolute numbers of cells bearing surface Ig were decreased to a lesser extent, whereas the proportion of these cells was increased. It is postulated that the increase in autoantibody formation and diminished delayed hypersensitivity seen in systemic lupus may be due to a loss of T-lymphocyte function.

Antibodies↗

Inhibition of bacterial adherence by secretory immunoglobulin A: a mechanism of antigen disposal.

Preparations of secretory iminunoglobuilin A (S-IgA) isolated from human parotid fluid specifically inhibited the adherence of Streptococcus strains to epithelial cells. Since bacterial adherence is a prerequisite for colonization of mucous surfaces. S-IgA-mediated inhibition of adherence would limit bacterial colonization. This mechanism can explain how secretory immunoglobulins function in the disposal of bacterial antigens.

Agglutination↗

Ultrathin carbon support films for electron microscopy.

Carbon support films only 4 to 6 angstroms thick have been made for use in electron microscopy. The determination of their thickness is based on geometrical calculation, electron scattering measurements, and elemental microanalysis.

Carbon↗

Light chain sequences of human IgM cold agglutinins (variable-region subgroups amino-acid sequence-kappa light chain-N-terminal).

The amino-terminal amino-acid sequence has been determined for the kappa light chains of nine IgM cold agglutinins with specificity for blood group-related carbohydrate antigens. Six of the nine sequences corresponded to the prototype VK(III) subgroup pattern, two to that of subgroup VK(II), and only one to the VK(I) subgroup. This distribution of kappa subgroups differs markedly from that of normal and myeloma proteins sequenced to date, where the VK(I) subgroup is more prevalent than either VK(II) or VK(III). Evidence is presented that supports the conclusion that the unusual subgroup distribution relates to the antibody property itself and not to some other attribute of these molecules.

Amino Acid Sequence↗

Assembly of tobacco mosaic virus in vitro: effect of state of polymerization of the protein component.

The in vitro assembly of tobacco mosaic virus from its constituent RNA and protein was followed by methods of electron microscopy. The effect of the state of polymerization of the protein upon the initiation of assembly of tobacco mosaic virus rods, and the subsequent rod elongation, was investigated. Protein in two identifiable states of polymerization was used: the 20S "disc", consisting of 34 monomers arrayed as a two-ring structure, and the 4S "A-protein", consisting of polymers in the trimer range of size. It is concluded, in confirmation of results of others, that rod assembly is initiated by the attachment of one end of the RNA chain of tobacco mosaic virus to one (or possibly a few) disc structure. Rod elongation, on the other hand, is found to take place by the sequential addition of structures of the size of A-protein, or smaller, to the previously initiated rods.

Chemical Phenomena↗