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Title:Immunological Effects of Microwaves, Ultrasound, and Hyperthermia: B-Lymphocyte Capping
Author(s):Sultan, Michel Farid
Department / Program:Electrical Engineering
Discipline:Electrical Engineering
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Engineering, Electronics and Electrical
Abstract:The present study was undertaken to evaluate the in vitro effects of microwaves, ultrasound, and hyperthermia on the redistribution and capping of antigen-antibody (Ag-Ab) complexes on the surface of freshly isolated splenic mouse B-lymphocytes. Capping is an active process where Ag-Ab complexes are regrouped under normal conditions into a polar cap on a small portion of the cell membrane. The expression and movement of receptors on B-lymphocytes and other cells of the immune system play an important role in antigen recognition, in triggering effector cells, and in immune regulation. In addition, the redistribution of specific receptor antigens on the surface of tumor cells may be important in immune recognition and cytolytic phenomena.
In the initial phase of the present study, the effects of hyperthermia on capping were investigated. The percentage of capping dropped gradually from more than 90% at 37(DEGREES)C to less than 10% at 42(DEGREES)C, whether the cells were heated immediately before or during the 10 minute capping assay. While less than two hours at 37(DEGREES)C were required for cells pretreated for 30 minutes at temperatures up to 42(DEGREES)C to recover the ability to cap Ag-Ab complexes, no such recovery was observed when cells were heated at 43(DEGREES)C.
No significant nonthermal field specific effects were observed following exposure to microwaves (2.45 GHz CW; 5-100 mW/cm('2)), amplitude modulated radiofrequency (147 MHz; 9,16, and 60 Hz modulation frequency; 0.1-48 mW/cm('2)), or ultrasound (0.99 MHz CW; 1-20 W/cm('2)), as long as both irradiated and control preparations were kept at the same temperatures. Further reduction of capping was observed on cells exposed to 20 W/cm('2) ultrasound at 41(DEGREES)C or 42(DEGREES)C. However, this significant reduction of capping was explainable on the basis of thermal effects only.
The physiological significance of inhibition of capping was studied in a series of antibody-complement (Ab-C) cytotoxicity experiments. The results demonstrated a strong correlation between hyperthermic enhancement of Ab-C cytotoxicity and hyperthermic inhibition of capping, suggesting that the increased sensitivity to Ab-C lysis resulted from the availability of more cell membrane binding sites for complement activity.
Issue Date:1982
Description:113 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.
Other Identifier(s):(UMI)AAI8302997
Date Available in IDEALS:2014-12-15
Date Deposited:1982

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