Epidemiologic research on the genetic risk factors in gastric and colorectal cancer.

This study is aimed to evaluate the hereditary risk factors in colorectal and gastric cancer, using the case-control method. The 21% heritability in gastric cancer (GC) and the 30% heritability in colorectal (CRC), serve as evidence for the higher involvement of hereditary factors in CRC. These findings are in line with some literature data regarding CRC, but at the same time they emphasize the increased awareness of hereditary risk factors in GC as well.

Sister chromatid exchanges induced by sarcolysine in human lymphocytes in vitro.

The effect of three concentrations of sarcolysine (0.5 micrograms/ml, 1 microgram/ml and 2 micrograms/ml) on the sister chromatid exchanges (SCE) was investigated in human lymphocytes in vitro. A dose related increase in SCEs frequencies was observed after sarcolysine administration and also a delayed development of cell cycle has been induced by the two last concentrations. The variation range of SCEs per cell was dose-dependent and it was considered to represent the acquired genetic instability induced by the drug.

Incidence of chromosomal aberrations in patients under combined tuberculostatic chemotherapy.

Chromosome studies were carried out on the peripheral blood lymphocytes of ten tuberculosis (tb) patients receiving combined tuberculostatic chemotherapy for long intervals (3-10 months) and on those of two control groups, one of ten healthy subjects and the second of ten other tb patients in whom the tuberculostatic treatment had been discontinued 10-19 months previously. An increased proportion of aberrations, particularly chromosomal breaks and achromatic gaps, were observed in the patients under treatment, suggesting a possible synergic interaction of INH and RMA in the production of chromosomal damage.

Cytogenetic effect of some anti-tuberculosis drugs in vitro.

The comparative cytogenetic effects of some widely used anti-tuberculosis drugs (PAS Na, PRA, RMA) were estimated depending on the in vitro administered concentrations, in human peripheral blood cultures. The structural chromosomal lesions were randomly distributed between the different chromosome groups of the human karyotype; nearly 10 to 30% of affected cells had more than one lesion per metaphase. In the treatements with PAS Na and PRA the analysis of the frequencies of the cell carring chromosomal aberrations and of the chromosomal lesion types indicated a dose-response correlation. The significance of the results obtained in vitro on the chromosome-breaking effects of anti-tuberculosis agents and the genetic peril is pointed out.

[Action of diphenylhydantoin on chromosomes]. / Action de la diphényl-hydantoïne sur les chromosomes.

PIP: The effect of diphenyl hydantoin, (DPH) a nonbarbituate anticonvulsant drug, on chromosomes and fertility was tested in cultured human lymphocytes, mouse fertility, and rat maternal marrow chromosomes and fetal development. Whole human blood from 5 male and 5 female subjects was cultured for 68 hours with phytohemagglutinin, then incubated for 2 hours in isotonic salts with .05-.3 mg per ml DPH, .02 mcg per ml colchicine, or .4 mg per ml sodium diethylbarbiturate. The mean number of metaphases per 1000 stimulated cells was 10.0 in controls, 40.3 with colchicine, 27.9 with diethylbarbiturate, and 30.5 with .25 mg DPH per ml. Both diphenylbarbiturate and DPH produced linear dose effect curves. These results were demonstrated not to be due to urea, since there were no differences in urea content, with a 2 hour urease micromethod. Mouse fertility was totally inhibited in 6 virgin mice given .1mg DPH daily for 10 days compared to 41 pups both of 6 control mice. In 6 pregnant rats given 25 mg DPH per 100 gm/orally 4 times daily for 2 days on gestation Days 7 and 8, there were 5 rats with all fetuses resorbed and 1 rat with 3 living and several resorptions. 6 controls had 6-14 normal fetuses each. 50 metaphase plates from each rat's femoral marrow and each fetus were examined 2 hous after injecting .3 mg colchicine per 100 gm. 30% of the metaphase cells from treated females and fetuses showed strongly contracted chromosomes and reduced number os "pulverized" chromosomes. These phenomena may have been due to inhibition by DPH of folic acid metabolism which is involved in purine synthesis.^ieng