UNCLASSIFIED ic II - BIOLOGY AND MEDICINE Research Activities Toxicity studies at ANL. Considerable research at Arge National Laboratory has been aimed at counteracting the effects ment of experimental plutonium and yttrium poisoning by zirconi hour after plutonium injections caused: (a) a marked increase in] plutonium excretion (from approximately 1.3 percent to as much as 50-60 pefcent of injected dose); and (b) a decrease in the amounts deposited in the bone (from approximately 65 percent-to 10 percent of the dose). The ¢ffect on yttrium is similar but less marked. In mice injected repeatedly with an LD-95 of beryllium gulfate (0.7 milligrams of beryllium per kilogram body weight), it was f@und that administration of avrintricarboxylic acid following each beryllidm injection not only protected the animals but enabled them to survive wfhile still containing lethal amounts of beryllium. Studies elucidatiig the mode of action of ATA have provided a rational basis for the seldction of other compounds of potential therapeutic value. The studies hav@ also given insight into some of the chemical mechanisms involved in md@talenzyme interaction. Studies on passive immunity. Experiments at Brookhaven Netional Laboratory have been conducted to test the effect of whole body danma irradiation on immunity mechanisms. A cobalt 60 source was used fdr the studies and radiation dosages of approximately 650 roentgens equivalent physical {the LD-50 being 750 reps) were administered to mice. finding suggests that the lowered antibacterial resistance follo body irradiatigqn is attributable primarily to the failure of phagpbcytosis by reason of the white cell deficiency, and that this phagocytosif may not be necessary in antiviral immunity or in prevention of intoxicatibbn by tetanus toxin. Photosynthesis and antibiotics. At the Radiation Laborafory, University of California (Berkeley), the effects of antibiotics afd other biological inhibitors on photosynthesis and dark COo fixation are] being investigated. The plant used for test is the alga Scenedesmus. Phe antibiotics used were chloromycetin, penicillin, aureomycin, and terrgmycin. —a. eee oe te ne ana SI the time of irradiation. Taken together with other bits of evidence, this Several anti-folic compounds and dinitrophenol were also tested. While UNCLASSIFIED AOE AR WES

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