Objective To study the risk factors which lead to increase in the incidence rate of hypospadias. Methods A case-control design was used.The mothers of 210 cases and 420 controls were interviewed by telephone or face-to-face,and the questionnaires were answered.Thirty probable risk factors were investigated.Statistical analysis was performed using univariate and multivariate unconditional Logistic regression analyses for evaluation of the data. Results All boys with hypospadias in the case group were of Han nationality.Only 5 cases had positive family history.Odds ratio (OR) of the factors investigated were:pregnant age (OR,38.63),threatened abortion (OR,4.71),progestin (OR,3.64),estrogen (OR,5.1),pesticide (OR,2.39),organic solvents (OR,2.12),season of pregnancy (OR,1.86) and detergent (OR, 1.87).But OR of frequency of abortion,weeks of gestation and birth weight were less than 1.The results of other 17 investigated factors were negative. Conclusions Threatened abortion,nonfull-term fetus,low birth weight and some environmental endocrine-disturbing chemicals ( pesticide,detergent,organic solvents,progestin and estrogen) may be risk factors associated with hypospadias.These environmental endocrine-disturbing chemicals may increase the incidence rate of hypospadias.

OBJECTIVETo study the damage of DNA in rat bone marrow cells induced by mustard gas.

METHODMale SD rats were randomly divided into six groups. Physiological saline, propylene glycol and mustard gas(0.2, 0.4, 0.8, 1.6 mg/kg) were given separately by i.p. injection. 5 rats in each group were killed after 0, 24, 48, 72 hours of exposure. The DNA damage in rat bone marrow cells was assayed by single cell gel electrophoresis (SCGE).

RESULTSThere is no significant difference of DNA damage among all groups at 0 h(P > 0.05). The rates of DNA migration and the lengths of DNA migration of the rat bone marrow cells in propylene glycol group at 24, 48, 72 hours were 15.4% +/- 0.21%, 16.0% +/- 0.19%, 15.7% +/- 0.23% and (11.4 +/- 0.2), (13.5 +/- 0.3), (12.8 +/- 0.2) micron respectively, and they were significantly higher than those of physiological saline group at the same time(P < 0.05). The rates of DNA migration and the lengths of DNA migration of the rat bone marrow cells in mustard gas groups at 24, 48, 72 hours were significantly higher than those in physiological saline group and propylene glycol group at the same time(P < 0.05).

CONCLUSIONMustard gas could induce DNA damage in rat bone marrow cells. The damage was likely to rise as the dose increased and was time-dependent.

Animals ; Bone Marrow Cells ; drug effects ; ultrastructure ; Comet Assay ; DNA Damage ; Dose-Response Relationship, Drug ; Male ; Mustard Gas ; toxicity ; Rats ; Rats, Sprague-Dawley ; Time Factors