Objective To provide improvement measures and recommendations to improve preven-tive medicine's clinical internship. Methods 88 third-year students and 82 fifth-year students of preventive medicine in Sichuan University were surveyed. Then 81 valid questionnaires of the third grade and 79 valid questionnaires of the fifth grade were input into EpiData, and SPSS 17.0 was used to analyze the data. Then, in-depth interviews were conducted among 6 employees and 2 professional teachers of the employing units, and the interview records were organized to form an interview summary. Results The third-year preventive medicine students who are preparing to take part in the clinical internship know little about the clinical in-ternship, which accounts for only 0％and 92.59％(75) think that the internship content should be different with the clinical medicine, in the meantime 44.44％ (36) think chief resident should be the internship teacher. For the fifth-year preventive medicine students who have finished the clinical internship, only 3.80％(3) is very satisfied with clinical internship;84.81％(67) are considered to take into account the pro-fessional characteristics of the clinical practice; meanwhile, the satisfaction of the knowledge or the ability learned from the clinical internship as well as the help in the post-graduation job is only 8.86％ (7); the employer's and professional teachers consider that the related clinical internship program of the preventive medicine student should be suitable for prevention medical students , and at the same time , preventive medicine students should focus on learning clinical knowledge related to disease prevention. Conclusion The clinical internship of preventive medicine needs further improvements, such as adjusting practice con-tents, learning teacher, management methods to form a clinical practice system characterized by preventive medicine so as to meet the needs of employers and students.

The progress in the experimental and epidemiological studies on the mutagenic and carcinogenic effects of gasoline engine exhausts were reviewed in the present paper. Current data showe that gasoline engine exhaust is a genotoxic agent and mutagen to bacteria, animal and human, but for its carcinogenic effects on animal by inhalation route, no new report has been published. So far no consistent relationship has been seen between cancer risk and gasoline engine exhaust exposure in epidemiological fields.

Objective To study the DNA damage and repair of normal lung interstitial cells and human lung adenocarcinoma cells exposed to cigarette smoke. Methods Cultured human embryo lung fibroblasts (HLF) and human lung adenocarcinoma A549 cells. Mainstream smoke was collected by using dimerhyl sulfoxide (DMSO) and phosphate buffer solution (PBS) as absorbents. MTT assay was used to test the cytotoxicity of the solutions of cigarette smoke, then selected the concentrations of the solutions with no obvious cytotoxicity to treat cells and detected DNA damage and repair by comet assay. Results As treated with original solutions or 1/2 dilution of DMSO cigarette smoke solutions only, the Viability of cells was below 80%, but it was beyond 80% when treated with PBS solutions. The results showed that a significant difference of DNA damage was seen between the treated groups and negative control groups (P0.05),but the DNA damage caused by DMSO solutions was worse than PBS solutions significantly (P

liver cells.Repair test showed that liver cells had the strongest repair ability,spleen cells were the second and kidney cells had no repair ability nearly within 2 h incubation. Conclusion The tissue cells had a big difference to oxidative damage and repair ability and comet assay could be used as detection of DNA oxidative damage and repair ability in exo_chemicals.

Methanol fuel is a most promising substitute for gasoline. It is scarcely reported about methanol-fueled exhaust on the health effect, neither about genotoxicity research between methanol- and gasoline-fueled exhaust. In the present study, the two kinds of exhaust were sampled directly from tailpipe at the same type bus, the same state, L5178Y thymidine kinase (TK) gene mutation assay was used to investigate their genotoxicity at the same dose range, and compared with micronucleus and comet assay. The results showed that the genotoxicity of gasoline-fueled exhaust is stronger than that of methanol-fueled exhaust, while the cytotoxicity of methanol-fueled exhaust is stronger than that of gasoline-fueled exhaust at dose range. The study demonstrated that L5178Y TK gene mutation assay is more sensitive than micronucleus and comet assay.
Gasoline ; adverse effects ; Humans ; Methanol ; adverse effects ; Motor Vehicles ; Mutagenicity Tests ; Mutation ; Thymidine Kinase ; genetics ; Vehicle Emissions ; adverse effects

Objective : To explore the microbial contamination status of household washing machines and evaluate the improvement effect of professional washing machine cleaning on microbial contamination. Results : After washing , the total number of fungi in the washing machine ranged from 0 to 49. 22 CFU/cm2 . The fungal clearance rates of the outer wall of the inner cylinder, filter screen , sealring , washing water and detergent drawer box were 99. 36% , 99. 74% , 99. 76% , 99. 51% and 99. 64% , respecing , the number of coliform bacteria was close to 0. Before washing , the average detection rate of Salmonella in the washing machine was 5. 33% , the average detection rate of Shigella was 2. 67% , and no Candida albicans was detected. After washing, Salmonella , Shigella and Candida albicans were not detected. After washing , the total number of fungi in the washing machine ranged from 0 to 49. 22 CFU/cm2 . The fungal clearance rates of the outer wall of the inner cylinder, filter screen , sealring , washing water and detergent drawer box were 99. 36% , 99. 74% , 99. 76% , 99. 51% and 99. 64% , respecing , the number of coliform bacteria was close to 0. Before washing , the average detection rate of Salmonella in the washing machine was 5. 33% , the average detection rate of Shigella was 2. 67% , and no Candida albicans was detected. After washing, Salmonella , Shigella and Candida albicans were not detected. Conclusion There are a large number of bacteria and fungi in the household washing machine before cleaning , and there are Salmonella and Shigella contamination. After professional cleaning , the hygiene condition of the washing machine is significantly improved.