Biologic effects of microwave exposure. II. Studies on the mechanisms controlling susceptibility to microwave-induced increases in complement receptor-positive spleen cells

In attempting to evaluate the mechanisms responsible for susceptibility to the inductive increase in splenic complement receptor-positive (CR⁺) cells following exposure to 2450-MHz microwaves, it was found that sensitivity to microwave-induced CR⁺cell increases was under genetic control. In particular, evidence was accumulated suggesting that regulation was under the control of a gene or genes closely associated with but outside of the mouse major histocompatibility complex (H-2). All responsive strains of mice tested were of the H-2^k haplotype, while mice of the H-2^a, H-2^b, H-2^d and H-2i⁵ haplotypes were refractory to the microwave-induced increases in CR⁺ cells. By utilizing certain H-2^k strains of mice that were genetically unable to respond to endotoxin, we were able to show that these strains of mice responded to microwaves, but not to endotoxin, by increasing CR⁺ cells. Microwave-induced increases in CR⁺cells were not mimicked by the intraperitoneal injection of hydrocortisone. Athymic mice responded to microwave exposure, indicating that this event was not regulated by the T-cell population. Mice less than eight weeks old were found not to be susceptible to exposure to 2450-MHz microwaves. These studies indicate that microwaves do induce changes in the population of cells with specific cell-surface receptors, that susceptibility to these changes is under genetic control, and that it is unlikely that endotoxin, corticosteroids, or regulatory T cells play a significant role in the mechanisms regulating these increases.     

Simple method to isolate vacuoles and protoplasts for patch-clamp experiments

It was not possible to obtain protoplasts or vacuoles from the thallus of the liverwortConocephalum conicum by applying cell-wall-degrading enzymes. Therefore, a surgical method was developed to isolate protoplasts and vacuoles. A thallus was plasmolyzed and cut. The few protoplasts along the cutting edge that were not destroyed emerged from the edge under deplasmolysis and became thus accessible for a patch pipette. Whereas under slightly hypoosmolar conditions the emerging protoplast remained largely intact, more hypoosmolar conditions gave rise to isolated vacuoles. This method to isolate protoplasts and vacuoles could also be applied to other plant tissues like leaves ofArabidopsis thaliana. Patch-clamp measurements were performed with isolated vacuoles and excised tonoplast patches. A slowly activating vacuolar channel inC. conicum displayed the characteristic features of higher-plant slowly activating vacuolar channels.Abbreviations AP action potential - SV channel slowly activating vacuolar channel     

Prolyl hydroxylase activity as an index of liver damage induced by ethanol

It was found that chronic intoxication of rats with ethanol results in an increase of prolyl hydroxylase activity in liver and serum of the experimental animals. The increase of enzyme activity precedes the morphological symptoms of liver damage. The possibility arises that the assay of prolyl hydroxylase in serum or in liver biopsy samples could be useful for the diagnosis of the tendency of some individuals to develop liver cirrhosis induced by ethanol.