Biomedical subjects

S Davis

Publications and source records attributed to S Davis.

At least 505 records · Page 28Linked to original sources

PubMed1975

Hypothesis: differentiation of the human lymphoid system based on cell surface markers.

Human lymphocytes can be separated into distinct populations based upon receptors on their cell surface. Thymus-derived (T-cell) lymphocytes can be identified by their ability to form rosetts with sheep erythrocytes (SRBC); bone marrow-derived (B-cell) lymphocytes bear characteristic surface markers for immunoglobulin, complement, and the Fc portion of IgG. Recently, populations of lymphocytes having either multiple markers or no detectable markers (null cells) have been observed. Based on studies of cell surface markers, a scheme is proposed that expands the known differentiation of the lymphod cell to include subpopulations which represent developmental stages. It is suggested that lymphocyte maturation involves alloantigenic changes in a circulating stem cell-drived nill cell, leading to a cell bearing markers for both T- and B-cells. It is from this latter cell that the classic T- and B-cells ultimately arise. Maturational defects which may explain the origin of primary lymphoproliferative diseases are discussed.

Ataxia Telangiectasia↗

PubMed1975

Genetic control of the murine cell-mediated immune response in vivo. II. H-2 linked responsiveness to the synthetic polypeptide poly(Tyr,Glu)-poly(DL-Ala)--poly(Lys).

Cell-mediated immunity in response to (T,G)-A-L was studied with a radioisotopic footpad assay. It appears that in vivo cell-mediated immune responsiveness to (T,G)-A--L is linked to the H-2 complex, as was demonstrated previously for specific antibody snythesis. Evidence is presented in this report which indicates that the cell-mediated immunity measured is a function of a population of T cells. The apparent controversy between results obtained by analyzing antibody formation and cell-mediated immunity can be explained by assuming the need for cell cooperation between helper T cell and effector T cell, because efficient purely cellular immunity is analogous to T-B cell cooperation needed for antibody production.

Animals↗

PubMed1975

Computerized EEG: predictor of outcome in schizophrenia.

Based on a double blind cross-over study, it was determined that schizophrenic patient who have more high frequency fast activity and a lesser degree of alpha and slow waves in computerized EEG before the treatment have a better therapeutic outcome to the major tranquilizer (neuroleptic) treatment. The correlation between pretreatment high frequency computer EEG measurements and better therapeutic outcome reached the level of statistical significance. "Therapy resistant" schizophrenic patients were characterized by a lesser degree of very fast beta activity, more alpha waves and slow waves, higher amplitudes in computer EEG, and a lesser degree of acute (florid) psychotic symptomatology but more "negative" symptoms such as motor retardation and blunted affect. One of the most striking results of the study is the finding that schizophrenic patients with certain psychopathological profiles also have similar computer EEG profiles.

Adult↗

PubMed1975

Inhibition of the cellular immune response to simian virus 40 tumor cells in tumor-bearing and tumor-immune mice by concanavalin A.

The effects of in vivo-administered concanavalin A (Con A) on the kinetics of the primary and secondary cellular immune responses to simian virus 40-transformed tumor cells were investigated in BALB/c mice. Either a single initial dose of 400 mug Con A or daily doses of 50 mug depressed the cell-mediated immune response to tumor cells during the progressive growth of tumors, as determined by a radioisotopic foot-pad assay. The immune depression correlated with an increase in ultimate tumor weight. Similarly, Con A suppressed the antitumor cellular immune response in tumor-immune animals. Immune reactivity returned within 6 days after a single injection of 400 mug Con. Continuous administration 50 mug Con A resulted in a gradual decline in antitumor cellular immune responsiveness, which reached a plateau by the 5th day. Splenic lymphocytes from Con A-treated, immune mice failed to elicit a local adoptive transfer reaction; their immune responsiveness tended to return after incubation with alpha-methyl-D-pyranosyl sugars.

Animals↗

PubMed1974