N-Diazoacetylglycine amide, a diazochetoalkane, has been studied in vitro for DNA damage and repair in cells of a cloned subline from a BALB/c mouse. To our present knowledge, none of these compounds have been investigated for such activities. At nontoxic levels, a prolonged dose-dependent unscheduled DNA synthesis was observed by autoradiography. DNA damage was studied by sedimentation through alkaline sucrose gradients after the cells were lysed on the gradients. Treatment of the cells for 1 hr with nontoxic doses of N-diazoacetylglycine amide resulted in slower sedimentation of DNA. The number of single-strand breaks appeared rather linearly dose dependent for a large range of concentrations. Breaks were at their maximum after 1 hr of treatment, and no further increase in the number of breaks was seen. Some repair of the breaks probably occurs, but repair was sluggish even 68 hr after treatment. A significant part of the breaks was observed after incubation at 4 degrees in an ethylenediaminetetraacetate hypotonic solution. This seems to indicate that the compound does not require metabolic activation. Nontoxic doses of N-diazoacetylglycine amide and other similar derivatives exert mutagenic and carcinogenic activities. The presence of DNA damage and the difficulty in its repair at such doses could be related to both of these biological properties.

Azo Compounds↗

PubMed1974

[Colloid carcinoma of the ethmoid].

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Adenocarcinoma, Mucinous↗

PubMedDate not supplied

Frequency of micronuclei in lymphocytes from a group of floriculturists exposed to pesticides.

A large part of the commercial flower production in Italy is located in the located in the western part of the Liguria region, near the French border. The use of pesticides in this area has been much higher than the national average. The frequency of micronuclei in peripheral blood lymphocytes was evaluated in a group of 71 floriculturists working in this area and in a control group of 75 healthy blood donors living in the same area. A significant increase of micronucleated lymphocytes was observed in floriculturists as compared to unexposed subjects (8.57 vs. 6.67, p < .05). Females showed a marked increase in MN frequency (45% higher than males) independently of the exposure. A dose-response relationship was observed between duration of exposure and MN frequency. The condition of exposure was also found to influence the micronuclei frequency. Increased relative risks in greenhouse workers (RR = 1.31) and in people working alternately in the greenhouse and in the open field (RR = 1.46) was observed with respect to the reference population.

Agricultural Workers' Diseases↗

PubMedDate not supplied

[Effects of the cobalt ion on the in vitro growth of mouse fetus fibroblasts (author's transl)].

The effect of cobalt II (CoCl2.6 H2O) on growth and plating efficiency of an established line of BALB/c mouse embryo cells was examined. The degree of inhibition of cell proliferation was dependent on both cobaltous ion dose and duration of treatment. Plating efficiency was enhanced by low doses and/or short time of exposure, but was reduced by treatment with higher doses or of longer duration.

Animals↗

PubMedDate not supplied

Modulation of DNA damage by vitamin A in developing Sprague-Dawley rats.

Prenatal and neonatal Sprague-Dawley rats were given a diet deficient in or with an excess of Vitamin A and at the age of 55 days female progeny were treated with a single i.g. dose of 80 mg/kg DMBA or 50 mg/kg MNU. Under these experimental conditions it was found that the exposure of perinatal rats to a diet containing an excess of Vitamin A caused a decrease in the amount of DMBA- and MNU-induced DNA damage in the mammary gland and the liver of the female offspring. When diets were deficient in Vitamin A there was a dual effect in terms of DNA damage detected in the same organs, namely DMBA caused an amount of DNA damage comparable to controls, while the extent of DNA damage induced by MNU greatly increased in both organs. These results indicate that Vitamin A can permanently change the sensitivity of adult progeny to chemically induced DNA damage when it is given to pregnant and lactating females.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

[European multicenter cross-sectional study on exposure to low doses of benzene].

A cross-sectional multicenter european study has been carried out to evacuate the relations between exposure to low level of benzene and biological markers of internal dose (t,t-MA, S-PMA) and early biological effect (DNA-SSB). The research has shown significantly increased levels (adjusted for smoking habits) of the urinary excretion of t,t-MA, S-PMA and DNA-SSB in petrochemical workers (mean benzene level = 5,694 micrograms/m3) but not in filling station attendants, traffic police officers, and bus drivers compared to referent workers. Dose-response relations were detected between benzene air levels, t,t-MA, S-PMA and DNA-SSB in petrochemical workers, with significantly increased levels of DNA-SSB detected for benzene exposure levels in the range 391-1,800 micrograms/m3 (0.12-0.58 ppm).

Benzene↗