Increases in chromosome aberrations and in abnormal sperm morphology in rubber factory workers.

Subjects working at a rubber plant in a chemicals warehouse or in calandering and bambury units were analyzed for both sperm parameters and structural chromosome aberrations in peripheral blood lymphocytes. Sperm analysis was performed in a group of 24 workers for comparison with fertile (n = 24) and infertile (n = 24) control groups. The statistical analyses of semen volume, vitality and sperm count did not show significant differences between exposed and fertile groups but significant differences were found from the infertile group. A significantly lower proportion of normal sperm head shapes was found in exposed subjects when compared to the fertile group (40.1 vs. 57.8). Seven exposed workers were re-analyzed 1 year later and their sperm parameters did not change. The cytogenetic analysis showed a significant increase (3.90%) in the percentage of cells with aberrations in bambury workers (n = 11). However, no differences were found between calandering workers (n = 8) and control subjects (n = 10). Workplace air samples taken on the day of tissue sampling did not show any increase above the Cuban maximal allowed concentration for benzo[a]pyrene or toluene.

Policosanol inhibits cholesterol biosynthesis and enhances low density lipoprotein processing in cultured human fibroblasts.

Policosanol is a mixture of aliphatic primary alcohols isolated and purified from sugar cane wax, that induces cholesterol-lowering effects in experimental models and human beings. When human lung fibroblasts were incubated with policosanol for 48 hours prior to the experiment, a dose dependent inhibition of 14C-acetate incorporation into total cholesterol was observed, whereas labeled mevalonate incorporation was not inhibited. Even when cholesterol synthesis was not strongly inhibited, low density lipoprotein (LDL) processing was markedly enhanced. Thus, LDL binding, internalization and degradation were significantly increased after policosanol treatment. In addition, despite the fact that'cholesterol generation was not inhibited at the lowest dose of policosanol assayed, LDL processing was significantly increased. The current data indicate that policosanol inhibits cholesterol synthesis at the earliest steps of the cholesterol biosynthetic pathway. On the other hand, this study suggests that the increase in LDL processing may be partially explained by the inhibition of cholesterol biosynthesis, even though an sterol-independent mechanism might be responsible for the enhancement of LDL-receptor activity.

Policosanol inhibits cholesterol biosynthesis and enhances low density lipoprotein processing in cultured human fibroblasts

Policosanol is a mixture of aliphatic primary alcohols isolated and purified from sugar cane wax, that induces cholesterol-lowering effects in experimental models and human beings. When human lung fibroblasts were incubated with policosanol for 48 hours prior to the experiment, a dose dependent inhibition of 14C-acetate incorporation into total cholesterol was observed, whereas labeled mevalonate incorporation was not inhibited. Even when cholesterol synthesis was not strongly inhibited, low density lipoprotein (LDL) processing was markedly enhanced. Thus, LDL binding, internalization and degradation were significantly increased after policosanol treatment. In addition, despite the fact that'cholesterol generation was not inhibited at the lowest dose of policosanol assayed, LDL processing was significantly increased. The current data indicate that policosanol inhibits cholesterol synthesis at the earliest steps of the cholesterol biosynthetic pathway. On the other hand, this study suggests that the increase in LDL processing may be partially explained by the inhibition of cholesterol biosynthesis, even though an sterol-independent mechanism might be responsible for the enhancement of LDL-receptor activity

Policosanol inhibits cholesterol biosynthesis and enhances low density lipoprotein processing in cultured human fibroblasts

Policosanol is a mixture of aliphatic primary alcohols isolated and purified from sugar cane wax, that induces cholesterol-lowering effects in experimental models and human beings. When human lung fibroblasts were incubated with policosanol for 48 hours prior to the experiment, a dose dependent inhibition of 14C-acetate incorporation into total cholesterol was observed, whereas labeled mevalonate incorporation was not inhibited. Even when cholesterol synthesis was not strongly inhibited, low density lipoprotein (LDL) processing was markedly enhanced. Thus, LDL binding, internalization and degradation were significantly increased after policosanol treatment. In addition, despite the fact that'cholesterol generation was not inhibited at the lowest dose of policosanol assayed, LDL processing was significantly increased. The current data indicate that policosanol inhibits cholesterol synthesis at the earliest steps of the cholesterol biosynthetic pathway. On the other hand, this study suggests that the increase in LDL processing may be partially explained by the inhibition of cholesterol biosynthesis, even though an sterol-independent mechanism might be responsible for the enhancement of LDL-receptor activity(AU)

No increase in chromosome aberrations in workers from an oil catalytic cracking plant.

A study of structural chromosome aberration frequencies in blood lymphocytes was performed in a group of 20 oil catalytic cracking unit workers and in 26 subjects belonging to the office staff of an oil refining plant, as well as in 35 matched controls. Subjects in the latter group were of the same sex (males) and similar age as the exposed group, and had similar smoking habits. Benzo[a]pyrene levels in workplace air samples were also determined. The cytogenetic analysis failed to show any differences between the exposed and control groups. A slight increase in benzo[a]pyrene level above the Cuban national standard of 1 ng/m3 was found during the air sample analysis in the oil catalytic cracking unit.

Mutagenicity of N-nitrosomorpholine biosynthesized from morpholine in the presence of nitrate and its inhibition by ascorbic acid.

N-nitrosomorpholine biosynthesis and inhibition in mice treated with nitrate, morpholine and ascorbic acid, was studied by means of the mutagenic activity in urine samples. The preincubation method was used and Salmonella typhimurium TA 1535 was the test strain. The results suggest that N-nitrosomorpholine biosynthesis was carried out when the animals were fed high doses of nitrate, however ascorbic acid was an inhibitor of this process.

Studies on mutagenicity of 2 bronchodilators under development in Cuba.

2 pyridoquinazolones, 2-amino-11H-pyrido[2,1-b]quinazolin-11-one (2-APQ) and 11H-pyrido[2,1-b]quinazolin-11-one (PQ), under development as anti-asthma drugs, were studied for mutagenicity. 2-APQ was found to be a strong mutagen in 5 strains of Salmonella typhimurium and a mild one in the forward-mutation system of the yeast Schizosaccharomyces pombe. Furthermore, 2-APQ had strong clastogenic effects in mouse bone marrow. Because of these results, development of 2-APQ as a bronchodilator was stopped. PQ, on the other hand, did not induce mutation in the 5 Salmonella strains or in S. pombe. S9 mix generally increased the response of 2-APQ in Salmonella dramatically. On the contrary, the mutagenic effectiveness of this compound in S. pombe was only slightly higher in the presence of S9 than without it, suggesting that metabolic activation was not effective in this system.