V. Suntzeff

The cellular localization of the two brain specific proteins, S-100 and 14-3-2.

Abstract An attempt has been made to localize, at a cellular level, the two brain specific proteins, S-100 and 14-3-2, by determining their relative concentrations in thalamic nuclei undergoing retrograde cell degeneration after appropriate lesions of the cerebral cortex. As the neuronal degeneration progresses the concentration of the 14-3-2 protein declines so that 6 weeks postoperatively it is only approximately 40% of its control level. On the other hand, there is a slight, but statistically significant, increase in the level of the S-100 protein between the 1st and 4th postoperative weeks which appears to be correlated with the early gliosis in the affected nuclei. On this basis it is suggested that 14-3-2 is primarily a neuronal protein and that the S-100 protein is largely, if not exclusively, confined to glial cells.

REGIONAL CHANGES IN CNS LEVELS OF THE S‐100 AND 14‐3‐2 PROTEINS DURING DEVELOPMENT AND AGING OF THE MOUSE

The levels of the S‐100 and 14‐3‐2 proteins were determined in a number of regions of mouse brain at intervals from 1 day to 30 months of age. Both S‐100 and 14‐3‐2 were found in measurable amounts as early as the first day of postnatal age but did not begin to accumulate rapidly in the forebrain, brain stem and cerebellum of the mouse brain until some time between the 7th and 14th days. From days 14 to 28 the levels of S‐100 and 14‐3‐2 in each region continued to increase rapidly with the exception of the forebrain where the rate of accumulation of S‐100 appeared to lag considerably behind that in the other regions. The proteins continued to accumulate at a rapid rate until approximately 6 months of age.

Serum lactic dehydrogenase activity as indication of neoplastic growth and regression.

Summary Lactic dehydrogenase activity of the sera of Swiss and Leaden mice increases promptly after tumor transplantation and decreases with tumor regression.

Preliminary report on application of iodine in prevention of surgical dissemination of viable malignant cells

Summary Two preliminary experiments were performed to determine the effectiveness of weak iodine solutions in prevention of “studding” and growth of highly malignant transplantable rhabdomyosarcoma tumors in C 3 H mice. The results showed that iodized sutures prevented “studding” in 67.4 per cent of the animals, as well as retarding the growth of tumors in the remaining 32.6 per cent of the mice in which the tumors appeared. The immersion of rhabdomyosarcoma cells in weak (0.1 to 12.5 mg. per cent) iodine solution prior to subcutaneous implantation in C 3 H mice resulted in decreasing the number of “takes”, even at concentrations of iodine as low as 2.5 mg. per cent.

Polarographic determination of pyridine nucleotides. Application of the method to normal and malignant tissues

Abstract A polarographic method for the determination of pyridine nucleotides in tissues is described.

Carcinoma-like proliferations in vagina cervix and uterus of mouse treated with estrogenic hormones.

We have referred 1 to the fact that in mice injected with preparations of estrogenic hormones over long periods of time abnormal proliferations of varying degrees of intensity may be induced not only in the mammary gland but also in certain parts of the vagina, cervix, and uterus. In a number of cases conditions were observed which in human beings would be considered precancerous lesions or as changes representing very early stages of cancer. In the monkey, Overholser and Allen 2 noted that in the cervix atypical epithelial proliferations were induced through administration of ovarian hormones. However, these investigators added traumatization of the tissue to the action of the hormones, while in our experiments the tissues were left intact. In two recent publications Lacassagne 3 described adenomatous proliferations of the uterine glands in the rabbit and in the mouse; in some cases the glands penetrated through the muscular layer. Quite recently we have autopsied a mouse in which proliferative changes had progressed further than in any of the others observed. This mouse, of the “Old Buffalo” strain in which spontaneous tumors are relatively rare, had been injected with estrogenic hormones for 24 months, 20 days, beginning at the age of 18 days. During the first 18 months this animal received 10 rat units of theelol in water daily; for the remaining 6 months, 20 days, daily injections of 30 rat units of theelin. At autopsy vagina, cervix, and uterus were very much enlarged. There were adhesions between the vagina and cervix and the surrounding pelvic tissues. Microscopic examination showed very extensive proliferation in the upper part of the vagina near the cervix, in various parts of the cervix, and in the uterus.

Prostatic fraction of acid phosphatase in human serum.

Summary Serum acid phosphatase represents a mixture of different molecular forms of the enzyme which can be separated and characterized. At least 2 major components can be separated by column chromatography with high recovery of the enzyme activity. The prostatic fraction of acid phosphatase appears, on the basis of its chromatographic behavior and its sensitivity to tartrate inhibition, to be localized in the second chromatographic peak.

Combined action of cigarette tar and beta radiation on mice

Periodic beta irradiation from Sr/sup 90/ to distributed areas of the skin of mice in total doses of as much as 20,800 rep when applied concurrently with cigarette tar produces an additive effect in the production of epidermal carcinogenesis. There is no svidence of a synergistic effect between the two carcinogens. Radiation alone has little carcinogenic effect on the skin as applied under the conditions described. Groups with greater percentuges of malignant skin tumors have had shorter lives than those with smaller percentuges or without skin tumors. The percentage of tumors of the lung, leukemia, mamary- gland carcinoma, and hepatoma was greater in groups in which the percentage of malignant tumors of the skin was low. (auth)

Chromatography of Proteins of Squamous Cell Carcinomas and Normal Epithelium of Mice.

Summary These results show that the above chromatographic procedure can be used to separate different protein extracts into a number of fractions and to investigate the distribution of various enzyme activities to pick out qualitative enzymic differences between malignant tumors and the normal tissues from which they arise.

Incidence of Mammary Cancer and Nature of the Sexual Cycle in Various Strains of Mice.

Loeb and Genther 1 studied the characteristics of the sexual cycle in 2 different strains of mice, which were believed to differ in their incidence of mammary cancer. Subsequently it became doubtful to what degree the cancer incidence differed in these mice, and further-more a comparison of only 2 strains of mice did not seem sufficient. Soon after completion of this first series, we began therefore a new and more extensive series of experiments. In the meantime there appeared communications by Lacassagne 2 and by Harde, 3 which seemed to establish a connection between the differences in the intensity of follicular hormone action during the sexual cycle and the incidence of mammary cancer. Quite recently, however, Bonser 4 in comparing 2 strains of mice differing in the incidence of spontaneous tumors did not find any correspondence between these 2 conditions. Our own investigations are based on the study of 10 strains of mice markedly differing in their tumor incidence. We considered the following characteristics in the sexual cycle: (1) The duration of the sexual cycles and the number of cycles in individual mice, and the averages in the various strains. (2) The average duration of the periods of keratinization and the relation between the periods of oestrus and dioestrus in the various strains and in the individual mice composing them. (3) The degree of regularity of the oestrous cycles. We may summarize our results by stating that there was no parallelism noticeable between any of these factors and the incidence of mammary cancer either in the individual mice or in the whole strains. We studied the effect of 2 different diets on the characteristics of the sexual cycle. In a first period of 30 days, the mice were fed solely on a diet of Purina Chow; in a subsequent period of 28 days the diet consisted of a mixture of chow, cracked corn and oats.