Henry J. Gomberg

Immunization to Schistosoma mansoni in mice inoculated with radiated cercariae.

Preliminary experiments indicate that mice inoculated with cercariae of Schistosoma mansoni that have been exposed to cobalt-60 radiation in the range of 2500 to 3000 rep develop immunity to reinfection with nonradiated cercariae.

Radio Iodine Uptake in Humans. V. Absolute Determination of Radio-iodine in the Thyroid

Summary A method of counting at a distance over the thyroid was used in animal and human subjects. This method involves the shielding of the Geiger counter tube from all radiation except the thyroid gland, by enclosing the counter in a long lead tube opening over the thyroid. The statistical error inherent in long distance counting is thereby effectively reduced. Independent beta assays were done on the thyroids of 5 dogs and 1 human adult who were subjected to total thyroidectomy immediately after counting with the above technic. Comparison of radioactivity of these glands, as determined by beta assays and by long distance gamma counting, showed a maximal deviation of the order of 20%, with the majority agreeing within about 5%. Suggestions are made regarding improvement of in vivo measurements such as employed in this technic.

Effect of cobalt 60 and X-ray on infectivity of cysticercoids of Hymenolepis diminuta.

Tests were conducted to determine the amount of Co/sup 60/ gamma radiation or x radiation necessary to apply to cysticanercoids of Hymenolepis diminuta, the rat tapeworm, in order to render them noninfective. Cysticercoide were obtained by feeding flour beetles (Tribolium confusum) with infective eggs from the tapeworm; the cysts recovered from the beetles were irradiated and counted numbers were fed to white rats to determine their ability to produce tapeworms. A dose of 12,000 rep Co/sup 60/ or 12,000 r x-ray prevented most cysticercoids from developing to tapeworms, and in some cases the few tapeworms that developed were stunted or sexually sterile. Doses of l5,000 rep Co/sup 60/ or 15,000 r x ray generally prevented cysticercoids from developing into adult tapeworms. (auth)

Effect of Cobalt-60 and X-Ray on Infectivity of Ascaris Eggs.

We have been interested in the feasibility of using ionizing radiations as a possible means of reducing or controlling certain parasitic infections of man and animals, particularly those transmitted by contact with contaminated soil or by ingestion of contaminated food. Investigators in food technology have been exploring the possible use of radiation in the sterilization of food by the application of doses of radiation sufficient to inhibit the growth of microorganisms, such as bacteria, molds, and yeasts. Information on the effect of similar radiations on food-borne parasites is therefore desirable.

An analysis of the series generator — Shunt motor oscillator

IN THE COURSE of a University “Open House” exhibition at the University of Michigan, a self-excited series generator — shunt motor oscillator was demonstrated. This inspired some of the students to search the literature for a theoretical discussion of the rotating machine oscillator. When their search proved fruitless, this brief essay was prepared and some quantitative tests of the theory presented were made. These tests are submitted for what value they may have for other teachers and anyone else who might be interested in the subject of machinery system analysis.

A nuclear reactor simulator for teaching purposes

The nuclear power reactor furnishes an excellent illustration of many of the principles and problems involved in the field of nuclear engineering. The design and operation of a portable electronic reactor simulator suitable for teaching purposes are discussed.