Oscar E. Tauber

Hereditary Differences in Serum Proteins of Normal Mice.

Summary In a study of the serum proteins of 7 mouse strains, it was established that there were inherent differences in the electro-phoretic patterns and in the amount of total serum protein. A distinct β-globulin component was found in only one, E, of the strains. The hybrid progeny of this strain also had this globulin component in their serum. This indicates that the protein is probably determined by a dominant gene (or genes).

Cortisone and Mortality in Mouse Typhoid. I. Effect of Hormone Dosage and Time of Injection.

Summary Cortisone, administered in single injections ranging from 0.25 to 5 mg, markedly decreased resistance of mice to S. typhimurium. Cortisone had the greatest effect on resistance when administered within 2 days before or after typhoid inoculation. Subcutaneous injections of two other steroids, progesterone and desoxycorticosterone acetate, in dosage range of 0.1 to 10 mg, had no effect on mortality in mouse typhoid.

Effect of DDT Ingestion on Total Cholesterol Content of Ovaries Of White Rat.

Summary and conclusions Female albino rats, age 30 days at beginning of the experiments, were fed ad libitum ground feed diets containing 100, 300, or 600 p.p.m. of pure p, p′ DDT. After 60 days, at age 90 days, the rats were sacrificed, ovaries were removed, weighed, and analysed either for total cholesterol or for organic chloride. Control females were handled the same way except food was uncontaminated with DDT. Other groups of 30-day females were started on 800 and 1,000 p.p.m. DDT diets but had to be sacrificed after 11 and 5 days, respectively, when death was imminent. Normal average ovarian organic chloride from control rats was 594 μ/g of tissue (range 558-637); average ovarian total cholesterol was 6.7 parts/1,000 (range 6.0-7.5). Average weight of both ovaries from control 90-day rats was 66.8 mg. On 100, 300, and 600 p.p.m. diets, the average calculated DDT contents of the ovaries were 364, 1423, and 2594 μ/g of ovary; the total cholesterol values were 3.9, 4.6 and 4.1 parts 1,000, respectively. Rats on the diet of 800 p.p.m. for 11 days, and on the 1,000 p.p.m. for 5 days showed less change in total cholesterol values (5.2 and 6.2, respectively) than did the 90-day rats, exposed to the DDT diets for 60 days, perhaps because the shorter exposure to the toxicant was not long enough to disrupt the sterol metabolism of the ovaries. On the other hand, the DDT content of ovaries from rats on 800 p.p.m. averaged nearly 4600 μ/g of tissue; and on 1,000 p.p.m., nearly 7500 μ/g. These data indicate a“selective accumulation” of DDT by female gonadal tissue. The disturbance in the sterol balance of the ovary may be significant in view of the opinion that cholesterol may be a precursor of progesterone.

Isolation of Staphylococcus albus from Hemolymph of the Roach, Blatta orientalis

Summary A bacterium, pathogenic for the roach, Blatta orientalis, was isolated in pure culture from the hemolymph of this insect, and proved to be Staphylococcus albus, as described in Bergeys Manual. Infections could be established in normal roaches by inoculation with diseased hemolymph or with broth cultures. Death was preceded by a characteristic progressive paralysis.

On Counting Mitotically Dividing Cells in the Blood of the Cockroach, Periplaneta orientalis (Linn.)

Although cell divisions in insect blood have been described by Hollande 1 and others, few quantitative counts apparently have been reported. This is a preliminary report of blood cell counts in P. orientalis, especially mitotically dividing cell (M.D.C.) counts. Large nymphs were used. Method. Antennal blood is taken into a pipette, made to handle 1.22 mm.3 blood, and rapidly diluted; a total count is obtained with a hemocytometer. A small drop of the antennal blood is placed also in a larger drop of diluting fluid on a slide, immediately stirred to prevent cell coagulation, covered with a coverslip, and rimmed with oil to prevent evaporation. The cells are randomly counted (oil immersion) and the % M.D.C. determined. The diluting fluid consists of 0.081 M NaCl, 0.002 M KCl, 0.001 M CaCl2, 0.005% Gentian Violet, 0.125% glacial acetic acid. Results. Some of the counts obtained are in Table I. Groups I and II include normal animals. In Group I only anaphases and telophases, while in Group II prophases, metaphases, anaphases, and telophases were counted. Each animal was bled only once, to make the count. Group III contains 3 series of 3 animals each: 1 control, bled once for the count, and 2 experimental animals bled extensively at previous times; for example, No. A-2 was bled at 4 and again at 2 days before the count. Group IV includes 1 control, bled once for each count, and 1 experimental animal, also bled extensively after each count. This experiment lasted 14 days. Discussion and Conclusions. The average total cell count of Groups I and II is 31,672 cells/mm.3 blood, or about the same as the count for P. fuliginosa obtained previously. 2 The average. % M.D.C. is 0.07 in Group I and 0.51 in Group II. Assuming this, difference to be due (1) to the counting of all phases in Group II and only anaphases and telophases in Group I and (2) to a longer time duration of pro- plus meta- as compared to ana- plus telophase, then the observed difference would indicate that the average mitotically dividing cell remains in all mitotic phases about 7 times as long as in the last 2 phases.

Histochemistry of selected tissues in vitamin deficient Tribolium confusum duVal

Abstract Newly emerged virgin females of Tribolium confusum duVal, when fed a control diet consisting of 20.7 percent amino acid mixture, 2.0 percent salts, 1.5 percent wheat germ oil, 1.0 percent cholesterol, 5.0 percent whole brewers yeast, 69.3 percent dextrin, and a mixture of nine vitamins, have normal ovarian development after 30 days on such a mixture. After 60 days on this diet, ovarian development is somewhat inferior. When hot water-extracted yeast is substituted for whole yeast in the control diet, ovarian development is slightly poorer and ovarian cells show signs of pycnosis in the germarium, and evidence of degeneration of the follicular epithelium. When T. confusum is fed a diet deficient in thiamin, less than 50 percent of the insects survive for 30 days. Nuclei of ovarian trophocytes of such insects are packed with RNA; cells of the follicular epithelium are extensively vacuolated; and the yolk appears abnormal. The gut epithelium of thiamin-deficient animals loses much of its RNA content. It is suggested that loss of gut function may play an indirect role in the development of the observed ovarian lesions.

Cortisone and mortality in mouse typhoid. II. Effect of environmental temperature.

Summary Mice infected with S. typhimurium were maintained for 3 weeks either in a warm environmental temperature of 29° to 36°C or a moderate temperature 21° to 25°C. At the warmer temperature, subcutaneous injections of cortisone were more effective in reducing survival. Room temperature had no significant effect upon survival of those infected mice which received the Aqueous Vehicle of cortisone.

Velocity of Hemocyte Circulation in the Elytron of the Cockroach, Periplaneta americana Linn

Summary The average hemocyte velocity in the subcostal cell of the elytron of the cockroach, Periplaneta americana Linn., is 34.3 ± 14.4 mm. per minute. The range of normal average velocities extends from 14.5 to 65.2 mm. per minute. This range approaches the range of 30 to 54 mm. per minute found in the capillaries of man. The highest hemocyte speed observed was 65.5 mm. per minute; the lowest 10.1. No relationship was detected between variations in velocity and sex or the heart rate of the insects used for this study.

Cortisone and Mortality in Mouse Typhoid. III. Effect of Natural and Acquired Immunity.

Summary Seven mouse strains which were selected for the wide range in their natural resistance to S. typhimurium were used. Typhoid resistance of every strain was decreased when 1 mg cortisone was given one day before typhoid inoculation. The difference between survival of cortisone treated mice and that of controls was evident at an earlier time in the genetically susceptible strains than in resistant strains. A single injection of 5 mg cortisone which reduced survival of non-immunized mice from 100% to 0% had no significant effect on survival of immunized mice.