[The correlation of Occupational musculoskeletal disorders and occupational safety behaviors in assembly line workers].

Objective: To study the correlation of occupation musculoskeletal disease (OMD) and safety behavior in assembly line workers. Methods: Selected assembly line workers of 3 manufacturing factory in Pacity as the objects of this study by judgement sampling. Questionnaires were used for messages collection including the general sociodemographic characteristic, OMD condition, occupational safety behaviors. Results: This study shows that, 826 OMD workers were found that the annual prevalence was 38.03%. The scores of work posture, handling habits, health habit in OMD group was lower than non-OMD group (P<0.01) but personal protection behavior was higher than non-OMD group (P<0.01) . Test of binary logistic regression revealed that age, workage, work posture, handling habits were the factors of OMD (P<0.01) . Conclusion: Safety behaviors were the potent factors of OMD that work posture and handling habits should be broadcast.

[Observation of ultrastructure and drug sensitivity of in vitro cultured exoerythrocytic form of Plasmodium berghei].

The ultrastructure of in vitro cultured exoerythrocytic stage (EE) of Plasmodium berghei (P. b.) was observed under transmission electron microscope (TEM). The drug sensitivity of EE was also measured in vitro. The EE was cultured in monolayer host cell, fixed and embedded in situ. The ultrathin sections were prepared and examined by routine methods. The TEM pictures showed that the fine structure of in vitro cultured EE was similar with that of EE grown in rat hepatocytes in vivo, as described by Meis et al. The parasite was found within a parasitophorous vacuole, with nucleus, mitochondria, endoplasmic reticula and Golgi apparatus were observed inside the parasite. After 24 h cultivation, the EE was incubated for 48 h in medium containing a serial concentrations of primaquine or chloroquine, then examined under light microscope. The percentage of abnormal parasites was calculated. The preliminary results showed that the sensitivity of cultured P. b. EE to primaquine and chloroquine was significantly different. At the same concentration of 1 x 10(-5) mol/L, the percentage of abnormal parasites was 38.5 +/- 3.9% and 5.7 +/- 1.9%, respectively. These results demonstrated that the in vitro cultivation system of P. b. EE would have potential utility in antimalarial drug research. (Figs. 1-6).

[In vitro cultivation of the exoerythrocytic stage of Plasmodium berghei].

This paper reports on an in vitro culture system for the exoerythrocytic (EE) stage of Plasmodium berghei (P.b.) using embryonic lung cells. The system was first developed by our laboratory in China. The embryonic lung cells were isolated by trypsin digestion of a human embryonic lung obtained from a therapeutic abortion case and was designated as cell line Elu 8801. Anopheles stephensi mosquitoes were infected by biting P.b. ANKA strain infected Kunming mice and after 18-21 days were dissected under aseptic conditions for preparation of a sporozoite suspension. This suspension was used to inoculate the monolayer cultures of Elu 8801. Regular examination found that following a cultivation for 48 hours, up to 100 multinuclear EE schizonts of P.b. could be observed on 1 x 1 cm cover slide. Seventy-two hours later mature merozoites were seen among part of the schizonts. An intraperitoneal inoculation of the supernatant culture medium to mice could induce malaria infection which could be transferred to other mice by blood inoculation. When the mice infected with the second generation were allowed to feed A. stephensi, sporozoites developed in the mosquitoes. The results demonstrate that the human embryonic lung cell line Elu 8801 established in our laboratory is susceptible to P.b. ANKA sporozoites and can support the developmental maturation of EE stages, producing potentially infectious merozoites.