THE BIOLOGICAL EFFECTS OF HIGH DOSAGE X-RADIATION UPON DIVIDING, NON-DIVIDING CELLS AND OTHER STAGES OF PARAMECIUM USING THE NEWLY DEVELOPED NYLON RADIATION CHAMBER METHOD
TEMPLE UNIV PHILADELPHIA PA
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In connection with a study of the biological effects of x-radiation upon various mitotic stages of paramecia, a new type of radiation chamber was developed. The new device consists of a piece of 1-in. machined Plexiglas with 2 ice wells and holes for 4 nylon hypodermic syringes of 2-cc capacity 0.1-cc graduation. A machined Lucite cap is tightly fitted over the tapering end of each syringe. Clones of 7 species of paramecia were irradiated in increment dosages of 50,000 r up to 600,000 r specimens were cultivated ins dessicated lettuce medium with Aerobacter aerogenes. Each experiment involved 800 specimens 200syringe in 2 cc of fluid after each dosage, 10 cells were expressed from the syringes and observed periodically for 48 hr. The species exhibited x-ray sensitivity in the following order P. bursaria, P. caudatum, P. aurelia, P. polycaryum, and P. trichium LD50170,000 r. Variations from the percent- survival curves indicated sensitivity levels and specimen differences. Nontoxic hematoporphyrin 110,000 to 140,000 placed in the syringes with normal paramecia caused 100 mortality in 12 hr after irradiation with 100,000 r as with paramecia, cancer cells in the presence of porphyrin appeared to be weakened in their resistance against x-rays. Sodium pentobarbital, sodium nitrite, and cysteine hydrochloride did not protect paramecia from radiation lethality. When lethality was reached, P. polycaryum disintegrated rapidly. P. caudatum, with dosages of 200,000 r to 250,000 r, moved slower with reduction in contractile vacuole formation.
- Radiation and Nuclear Chemistry