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Biomedical subjects

B G Smith

Publications and source records attributed to B G Smith.

15 recordsLinked to original sources
PubMed1979

The value of a perception and control test in predicting performance in dental students and ancillary personnel.

A test designed to measure basic manual perception and control skills, assumed to be less susceptible to the effects of haphazard and unplanned training, was developed and used with groups of dental students and ancillary personnel. The test was similar to one reported to be successful in predicting practical ability in American dental students. Statistical techniques were used to compare the results of the perception and control test with practical and theory examination results. The results show that the perception and control test is not a reliable predictor of performance with British dental students but was more successful with the ancillary groups and particularly with dental auxiliaries.

Dental Auxiliaries↗
PubMed1976

Effective colostomy irrigation.

The ultimate goal of the cone method of colostomy irrigation is to return patients with colostomies to their former role in society with confidence in themselves to the extent that having a colostomy is not considered a handicap. The results have generally been excellent. We believe all patients with stomas should be afforded the opportunity to attempt colostomy irrigation.

Colostomy↗
PubMed1975

Inhibitory effect of synthetic polyribonucleotides on the primary in vitro immune response.

The synthetic double-stranded polyribonucleotides, poly (rA):poly (rU) and poly (rI):poly (rC), were shown to be potent inhibitors of the in vitro plaque-forming cell (PFC) response to a thymus-dependent (SRBC) and thymus-independent (E. coli 0127 LPS) antigen in mouse C57BL/6 spleen cell cultures. The same polynucleotides had no effect on the PFC response of nude (athymic) mouse spleen cells to E. coli 0127 LPS, suggesting that functional T lymphocytes are necessary for the inhibitory effect. Enhancement effects were modest and inconsistent in the cultures. Poly (rA) and poly (rU) were ineffective as inhibitors. The data indirectly suggest that the inhibition may be due to the early production of interferon by functional T lymphocytes.

Animals↗
PubMed1975

Tartrazine: solid-phase radioimmunoassay studies of an azo dye implicated in allergic reactions (azo dyes and allergy).

A solid-phase radioimmunoassay procedure was adapted for the haptenic study of tartrazine, an azo dye implicated in various forms of allergy. Further, the haptenic relationship of tartrazine and aspirin was investigated, since sensitivity of individuals to the two substances is often clinically associated. The specificity of antibody to tartrazine was directed strongly toward a pyrazolone intermediate of the molecule, 1-(4-sulfophenyl)-3-carboxy-5-hydroxy-pyrazole. Aspirin did not cross-react with anti-tartrazine, suggesting that the clinical association of aspirin and tartrazine sensitivity in patients is a nonimmunological phenomenon.

Antigens↗
PubMed1975

Inhibition of the primary in vitro antibody response by interferon preparations.

The primary in vitro plaque forming cell (PFC) response of mouse (C57BL/6J) spleen cells to sheep red blood cells (SRBC) was inhibited by two sources of crude and two sources of partially purified mouse interferon. The substance(s) in the interferon preparations which induced PFC and antiviral inhibitory activity have the following common characteristics: a) The interferon preparations were of different potencies and specific activities, but they inhibited the PFC response in proportion to their activities; 20 to 60 units were the minimal amounts required for greater than 90% inhibition of the PFC response. b) Both the antiviral activity and the PFC inhibitory activity of the interferons were neutralized by antibody specific for mouse interferon. c) Both activities were partially or completely inactivated by heating at 60 degrees C for 1 h. d) Human interferons had neither antiviral activity nor PFC inhibitory activity in mouse cells. e) Limited exposure (4 h) of cells to interferon significantly inhibits both viral infection and the PFC response. f) Both the antiviral activity and the PFC inhibitory activity of the interferon preparations are acid stable. It is concluded, therefore, that the inhibition of the primary in vitro PFC response is due to interferon in the preparations. Maximum inhibition of the PFC response occurred when interferon was added to cultured at the same time as SRBC. Significant inhibition was also observed when interferon was added 1 day later, and slight enhancement was observed when added at days 2 and 3 of SRBC addition. Kinetic data showed that the greater the concentration of interferon added to the cultures, the earlier the effect on the PFC response. The presence of interferon in cultures for the first 4 h is sufficient to inhibit the PFC response. Interferon, then, appears to affect some early event(s), which leads to inhibition of the PFC response. Since mature T cells can be one of the sources of interferon, we have demonstrated a suppressor effect of a T cell lymphokine. The precise relationship of interferon to various expressions of suppressor T cell effects remains to be determined.

Animals↗
PubMed1975

The effect of staphylococcal enterotoxins on the primary in vitro immune response.

Staphylococcal enterotoxins, like several plant lectins, have been shown to stimulate mitogenic activity and lymphokine production in lymphocytes. The effect of enterotoxins A and B on the primary in vitro plaque-forming cell (PFC) response of mouse (C57BL/6) spleen cells to sheep red blood cells (SRBC) was examined. PFC responses in 4- or 5-day cultures were inhibited greater than 90% by 0.1 mug enterotoxin A and by 3- to 6-mug enterotoxin B when the toxins were added to the cultures either at the time of SRBC addition or 24 hr before. Both enterotoxins A and B were shown to be T lymphocyte mitogens. Kinetic data indicated that the enterotoxins (10 mug) inhibited the PFC response as early as day 3, but were relatively more inhibitory at days 4 and 5. The PFC response was inhibited when enterotoxins were added to cultures at the same time as antigen or a day later; it was enhanced when added at day 2; and it was unaffected when added at day 3 of 4-day cultures. Further, the presence of enterotoxin A during the first 24 hr of culture and subsequent removal was still as effective in inhibiting the PFC response as when it was present throughout the culture period. The PFC inhibitory properties of enterotoxins appear, then, to affect some early event(s) in the in vitro immune response. Alpha-methyl-D-mannopyranoside blocked the PFC inhibitory effect of concanavalin A (con A), but it had no effect on enterotoxin A. The two mitogens appear, then, to react with different receptors on the lymphocytes or to differ in the dynamics of their reactivity. The effects of staphylococcal enterotoxins on the PFC response of spleen cells were remarkably similar to those reported for lectins such as con A. Enterotoxins are structurally simpler than con A and should therefore be quite useful in studying various biologic activities of lymphocytes.

Animals↗