[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. A face-to-face survey was conducted with self-made questionnaires which covered demographic characteristics, water issues, dietary habits, genetic and medical history. Epidata 3.0 was used to build the database and SPSS 19.0 for the statistical analysis. RESULTS: In the univariate Logistic regression analysis, ten variables were found showing statistical significance. For the multivariate Logistic regression analysis, variables left in the model were labor intensity (OR=0.622, 95%CI: 0.435-0.889), preferring to drink after dinner (OR=0.316, 95%CI: 0.122-0.815), loving drinking (OR=0.232, 95%CI: 0.084-0.642), drinking tea regularly (OR=1.463, 95%CI: 1.033-2.071), eating more vegetables (OR=0.571, 95%CI: 0.328-0.993), the history of the urolithiasis (OR=2.127, 95%CI: 1.065-90.145). CONCLUSION: Drinking tea regularly, urolithiasis history and brain work are the risk factors of kidney calculi while loving drinking and eating more vegetables for the protection.

[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. Corresponding analyses were conducted with SPSS 16.0 statistic software. RESULTS: The top three injuries of faces and hands were burning tingling (48.7% & 41.3%), itch of skin (39% & 34.9%) and pigmentation (31.9% & 24.5%).The major injuries of eyes were ophthalmodynia (61.5%) , photophobia and tearing (61.4%), and blurred vision (50.2%). The incidences of facial and hands burning tingling, hands flushing, hands macula and papula were significantly different between the welders and auxiliary workers (P<0.05). The differences of facial and hands burning tingling, flushing, facial disesthesia and anaesthesia, symptoms and signs of eyes were significant in different working years groups (P<0.05). The top three usages of protective measures were welding masks (87.2%), gloves (84.3%) and glasses (65.9%). Except for UV cut cream, the usages of other protective equipments in the auxiliary workers were significantly lower than those in the welders (P<0.05). The logistic regression analysis showed that prolonged exposure to arc welding, using argon arc welding and CO(2) gas shielded arc welding, not wearing welding masks, and not using UV cut cream was significantly associated with the increased risk of face burning tingling, and the ORs were 3.894 (6 h to 8 h), 2.665 (4 h to 6 h), 2.052, 1.765, 1.759, 1.833, respectively; working years might be a protective factor, and the OR was 0.440, respectively. CONCLUSION: The study suggested that the UV radiation produced during welding operations not only caused harm to welders, but also to the auxiliary workers. Protection should be strengthened,for example, wearing welding masks, glasses, etc. Meanwhile automatic welding machines should be adopted by the factories to reduce the exposure time for workers.

[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. RT-PCR and Western blot were used to exam the mRNA and protein expression in selected clones. The expression level at different inducing times and concentrations of tetracycline were examined. MTT assay was used to observe the effect of P37 on proliferation of 293 cells. RESULTS: P37 protein, which is 43.5x10(3), was expressed in the selected clone as well as secreted from cells. Tetracycline showed a good regulation on the expression of P37 protein, which was not detectable without tetracycline induction. When induced with 2 mg/L tetracycline for 60 hours, the P37 protein expression reached maximum level. Cell growth was promoted after being transfected with p37. CONCLUSION: A stable cell line expressing P37 regularly was established, which provides a good cell model for studying p37 function and its molecular mechanism.

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. We found that p37 localized at the Golgi apparatus and could be secreted out of the cell. Human gastric cancer cells AGS, after being transfected with the p37 gene, were smaller, more spherical and easy to detach from each other. Their adhesion to matrix was also diminished and cytoskeleton in these stable p37 AGS cell was rearranged and transcription co-factor beta-actin was transferred to nucleolus with down-regulation of ICAM-1 and integrin beta1. These findings will be helpful for us to elucidate the effects of p37 on eukaryotic cells as well as to better understand the potential relationship between cancer and mycoplasma infection.