Wolcott B. Dunham

Propagation of Poliovirus in Chick Embryo Cell Cultures. I. Cultivation of 3 Virus Types

Summary Cell cultures were prepared from the chorioallantoic membrane of chick embryos. After 5 transfers these were tested for susceptibility to infection by representative virulent strains of the 3 immunologic types of poliovirus. Multiplication was observed until the series were terminated after 10 or 20 passages. Neutralization tests confirmed the identity of the viruses after passage. The susceptibility of these cells to infection with poliovirus is in marked contrast to that of the tissues from which they were derived.

Action of Penicillin and Other Antibiotics on Treponema Pallidum.

Summary The test for spirocheticidal action of drugs in vitro (Eagle2) has been used with certain antibiotic substances. Penicillin, originally presumed to be inactive in vitro, has proved to be active under these conditions in the relatively high concentration of 800 to 1600 Oxford units per 0.8 ml. Inadequate therapy of syphilis in a rabbit resulted in the production of a more resistant strain of Treponema pallidunz and emphasizes the importance of adequate initial therapy.

Further Experience with a New Blood Medium for the Cultivation of Mycobacterium tuberculosis.

* Retort Pharmaceutical Company, Long Island City 1, N. Y. Lot No. 17Y. glycerol (analytical grade), 1.0 ml; human bank blood (with ACD solution, see below), 30.0 ml; water (distilled), 69.0 ml; penicillin (100 u/ml.) t; final pH approximately 6.8.

Differential Inhibition of Virus Hemagglutination by Chlorophyllin.

PreparationThe agar was dissolved in the glycerol water by heating. The mixture was sterilized by autoclaving at 15 pounds pressure (1210 C) for 15 minutes, after which it was cooled to 450 C in a water bath. The blood and penicillin were added, the ingredients thoroughly mixed, and the medium dispensed aseptically into sterile screw-cap tubes and allowed to harden into slants. The flask was kept in a beaker of water in the bath to prevent tipping when the medium became depleted during the tubing process and was shaken frequently to maintain thorough mixture. Outdated human bank blood approximately four weeks old was used and contained ACD solution as follows: citric acid, 0.50 gm; sodium citrate, 1.37 gm; and glucose,

Chemotherapy of Infections with Cl perfringens in Mice by Homosulfonamides.

Summary Copper chlorophyllin inhibited hemagglutination by influenza A, mumps and Newcastle disease viruses. This action was not due to a dialyzable component. Hemagglutination by Newcastle disease virus was most affected. Part, at least, of the inhibition appeared to be due to a direct effect on the virus.

Culture of Leukocytes after Storage in Serum

Summary Except for sulfadiazine, nomosulfanilamide and its N1-methyl derivative were the most effective drugs in local treatment of experimental gas gangrene of the compounds tested. The acute toxicity of homosulfanilamide was less than that of its derivative. The chronic toxicity of homosulfanilamide in mice appeared to be no greater than that of sulfanilamide. These two compounds were not effective in the treatment of infections in mice with Strep. hemolyticus C203, H. influenza: 62/B, or Staph. aureus Smith, but they were bacteriostatic in vitro for staphylococci. Although infection with Cl. perfringens in mice is not strictly comparable with infection in man, these results indicate that homosulfanilamide may be worthy of a clinical trial in the local treatment of gas gangrene.

Toxicity of Antiseptics for the Chick Embryo.

Summary Cell lines were established from leukocytes stored in homologous serum for 2 weeks at 4°C. Similar viable cells may be present occasionally in serum used as a nutrient for tissue cultures and so may initiate mixed cultures. This can be prevented, however, by heating the serum for 15 minutes at 56°C to destroy any leukocytes present.

Prolonged Culture of Human Leukocytes in an Isolated Environment

The resistance of the chick embryo to toxic substances is a subject which has been little explored in spite of the fact that the embryo is well adapted to a variety of bacteriological and physiological experiments. The developing egg consists of rapidly growing embryonic tissue in a perfect nutritional environment. It comes sealed in an ampule, the shell, which is readily opened for inoculation or other manipulation and easily sealed again for the period of rein-cubation. The original purpose of the present study was to determine whether the fertile egg could be used as a medium for testing the inactivating effect of antiseptics on viruses. Such studies could be made only if the normal physiology of the embryo is not greatly disturbed by the injection of such agents. Three tests were performed on different days with each substance. Embryonated eggs which had been incubated for 6 or 7 days were candled and the location of the embryo marked on the shell. This mark was kept uppermost until the inoculation was completed. A hole was drilled through the shell over the air sac by means of a 2 mm dental bur or a carborundum disc. The injection was made by means of a 2-inch, 20 gauge needle fitted to a tuberculin syringe. The needle was directed slightly upward and inserted 3 cm into the egg. The amount injected was 0.05 cc in each instance. This represents 1 part in 1000 of total egg weight, or the equivalent of 70 cc for a man weighing 70 kilos. The eggs were candled daily and the day of death noted. The results are shown in Table I. The minimal lethal dose for man has not been determined for many of these substances.

VACCINATION OF CHILDREN WITH VARIOUS CHORIOALLANTOIC PASSAGES OF MEASLES VIRUS A Follow-up Study

Conclusions Cells capable of continuous propagation in vitro were cultured from peripheral blood of normal individuals under conditions of complete isolation from other cell lines. A lag phase of 7 weeks preceded rapid multiplication. Cultivation of these cells is apparently not dependent on the presence of a herpes-like virus similar to the leukovirus found in Burkitts lymphoma. The line has been cultured continuously for 1 year.