[Risk factors for the kidney stones: a hospital-based case-control study in a distric hospital in Beijing].

Objective: To explore the risk and protective factors of kidney calculi in order to put forward theoretical basis for preventive and control measures.

Methods: A 1:1 matched case-control study was performed using data from a hospital in Beijing. The case group included 100 inpatients who were diagnosed kidney calculi using B ultrasonic, X-ray and intravenous pyelography during the survey while other 100 urolithiasis and endocrine disease excluded inpatients who shared the same sex, within five years gap to the case group inpatients were for the control group.

[Investigation of occupational hazards of ultraviolet radiation and protective measures for workers in electric welding].

Objective: To investigate and analyze the occupational hazards of ultraviolet radiation, protective measures and related factors for typical symptoms among workers in electric welding, and to provide basic information for revision of the occupational standards of UV.

Methods: Questionnaires and physical examinations were used in this investigation. A total of 828 workers from four vehicle manufacturers in Beijing and Guangdong Province were selected.

[Establishment of a stable and regulable 293 cell line expressing mycoplasma hyorhinis protein P37].

Objective: To establish a stable cell line, which can express P37 protein of mycoplasma hyorhinis and be regulated by tetracycline, for investigating the effect of p37 on phenotype of cells and its mechanism.

Methods: Recombinant plasmid PcDNA5/FRT/TO-p37 was constructed and cotransfected with pOG44 into Flp-In-T-REx-293 cells by lipofectamine. Positive clones were screened with Hygromycin and Blasticidin.

Lipoprotein p37 from Mycoplasma hyorhinis inhibiting mammalian cell adhesion.

p37 protein is a membrane lipoprotein of Mycoplasma hyorhinis, and our previous work showed that there was high ratio of M. hyorhinis infection in human gastric carcinoma. To investigate the possible functions of p37 in cancer development, the nucleotide sequence of p37 gene was modified and expressed well in transfected cells.