Recommendations from the findings by the RCGP oral contraception study on the mortality risks of oral contraceptive users.
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Adult↗
Biomedical subjects
R J Booth
Publications and source records attributed to R J Booth.
Interferon-induced antibody suppression: a selective effect on high density, late responding precursor cells.
Mouse spleen cells have been fractionated into three subpopulations by density gradient centrifugation and the effect of interferon on the ability of each fraction to generate an antibody response in vitro has been examined. The results show that only the antibody-forming cell precursors (AFCP) of the high density, late responding fraction are suppressed by interferon. The presence of interferon had no effect on either the number or the mean size of clones of antibody-forming cells in cultures of the low and medium density fractions. Interferon-mediated suppression of the response of high density precursors was due to a decrease in the number but not the size of responding clones. These results suggest that interferon suppresses antibody responses by affecting the degree to which high density AFCP can becoming activated rather than the degree to which precursors proliferate.
Animals↗
Immune conservation: a possible consequence of the mechanism of interferon-induced antibody suppression.
The effect of interferon preparations on the development of single clones of antibody-forming cells generated against sheep red blood cells in mouse spleen cell cultures has been studied. It was found that the presence of interferon had no effect on either the number or the size of clones which developed early in the in vitro antibody response. At the peak of the response (day 3), a decrease in the number but not in the size of clones was observed in interferon-treated compared to control cultures, while by day 4 both the size and number of clones were significantly decreased. These findings indicate that interferon appears to affect only nonactivated B cell precursors by preventing them from becoming activated and commencing clonal expansion. Early responding precursors, which are in cell cycle, presumably having been previously activated in vivo, are refractory to interferon-induced suppression in vitro. The way in which this immunosuppressive activity of interferon might be of great advantage to an animal as a means of "immune conservation" during viral infections is discussed.
Animals↗
Modulating effects of interferon preparations on an antibody response in vitro.
The effect of mouse interferon preparations on the primary in vitro antibody response of mouse spleen cells was studied. Concentrations of interferon greater than 8 units per ml significantly inhibited the antibody response while low concentrations of 0-08-0-8 units per ml could be shown to be mildly enhancing. Various treatments which affected the antiviral activity of the interferon preparations reduced the immunosuppressive activity to a similar extent. Interferon acts during the first few hours of a response but the effect is not apparent for at least 50 h. Interferon had no effect when added after 48 h. The kinetic data has been interpreted as demonstrating interferon-sensitive and interferon-resistant components of the in vitro response. The results from investigations of the polyclonal response to lipopolysaccharide support the view that interferon acts mainly on B cells alone, although effects on T-B interactions cannot be excluded.
Animals↗
Conditioning allergic skin responses in humans: a controlled trial.
Classical conditioning of immune responsiveness has been extensively investigated in animals, but few successful studies have been reported with humans. We report the results of a study in which an attempt was made to demonstrate conditioned alteration to an allergic skin test response in humans. For 8 of 10 trials, allergic skin tests were administered to one forearm of volunteer subjects, and saline was administered to the other forearm. For the other two trials, the test substances were covertly switched between arms, but no changes in response resulted from this maneuver that could be ascribed to conditioning.
Adult↗
Reduction in skin reactions to histamine after a hypnotic procedure.
This study sought to test whether a cognitive-hypnotic intervention could be used to decrease skin reactivity to histamine and whether hypnotizability, physiological variables, attitudes, and mood would influence the size of the skin weals. Thirty eight subjects undertook three individual laboratory sessions; a pretest session to determine sensitivity to histamine, a control session, and an intervention session during which the subject experienced a cognitive-hypnotic procedure involving imagination and visualization. Compared with the control session, most subjects (32 of 38) decreased the size of their weals measured during the intervention session, and the differences between the weal sizes produced in the two sessions were highly significant (N = 38; t = 4.90; p < .0001). Mood and physiological variables but not hypnotizability scores proved to be effective in explaining the skin test variance and in predicting weal size change. Feelings of irritability and tension and higher blood pressure readings were associated with less change in weal size (i.e., a continuation of reactivity similar to that found in the control session without the cognitive-hypnotic intervention), and peacefulness and a lower blood pressure were associated with less skin reactivity during the intervention. This study has shown highly significant results in reducing skin sensitivity to histamine using a cognitive-hypnotic technique, which indicates some promise for extending this work into the clinical area.
Adolescent↗