[Comparative investigation of hearing injury in workers exposed to punching machine noise and to steady state noise].

OBJECTIVE: To compare the difference of effects on hearing injury between punching machine noise and steady state noise. METHODS: The subjects of present study were 100 workers, included 38 workers exposed to punching machine noise from forging shops and 62 workers exposed to steady state noise from drawbench or abrasive dust workshops. The individual noise dosimetries were used to detect noise that workers exposed, and cumulative noise exposure (CNE) was then calculated. On the basis of GBZ 49-2007, the worker hearing was tested, and the results were assessed. RESULTS: There were no differences of CNE between group exposed to punching machine noise and group exposed to steady state noise. The hearing loss rate (55.3%) at high frequency in workers exposed to punching machine noise was significantly higher than that (32.3%) in workers exposed to steady state noise (P < 0.01). CNE and the hearing loss rate at high frequency showed dose-response relationship (P < 0.01). CONCLUSION: when the exposure levels of workers were similar, the hearing injury induced by punching machine noise may be significantly higher than that induced by steady state noise.

[Expression and significance of RhoA and NF-ΚB in human gastric carcinoma].

OBJECTIVE: To investigate the expression of RhoA and NF-κB in gastric carcinoma and their correlation with clinicopathological fearures. To determine the effective prognostic factors of long-term suivival of gastric carcinoma patients. METHODS: The role of RhoA and NF-κB in gastric carcinoma was assessed by tissue array technology and the levels of RhoA and NF-κB expression in paraffin-embedded tissues was quantified by immunohistochemistry from 189 cases of gastric carcinoma, 54 cases of their adjacent tissues, and 32 cases of normal gastric mucosa. The prognosis of gastric carcinoma was evaluated by Kaplan-Meier survival analysis and Cox multivariate regression analysis. RESULTS: The positive rates of RhoA expression were 84.7%, 68.5% and 65.6% in gastric carcinoma, adjacent tissues and normal mucosa, respectively. The expression of RhoA in gasric carcinoma was significantly higher than that in adjacent tissues and normal mucosa (P < 0.05). The positive rates of NF-κB expression were 75.1%, 42.6% and 15.6%% in gastric carcinoma, adjacent tissues and normal mucosa, respectively. The expression of NF-κB in gasric carcinoma was significantly higher than that in adjacent tissues and normal mucosa (P < 0.05). RhoA was positively linked with NF-κB (r = 0.203, P = 0.005). In gastric carcinoma, the expression of RhoA was related with depth of invasion (P < 0.05), and the expression of NF-κB was related with depth of invasion and lymph node metastasis (P < 0.05). The Kaplan-Meier survival analysis showed that the tumor size, lymph node metastasis, depth of invasion, expression of RhoA and NF-κB can shorten the cumulative survival rate. With these paramaters entering the Cox multivariate regression analysis mode, it was revealed that expression of NF-κB, lymph node metastasis and depth of invasion are independent prognostic factors. CONCLUSIONS: The overexpression of RhoA and NF-κB is involved in the occurrence and development of gastric carcinoma. RhoA is positively linked with NF-κB. They are correlated with the invasion and metastasis of gastric carcinoma. The expression of NF-κB, lymph node metastasis, depth of invasion are independent prognostic factors playing an important role in prediction of the clinical outcome after radical resection of gastric carcinoma.

[Prevalence of occult hepatitis B virus infection and its phylogenetic features among mother-teenager pairs].

OBJECTIVE: Prevalence of occult hepatitis B virus (HBV) infection (OBI) was investigated in a paired mother-teenager population and HBV S gene variation including overt and occult HBV, was determined. METHODS: A follow-up study based on an initial survey of 135 mother-teenager pairs was carried out through collection of questionnaires and blood samples HBsAg were detected by ELISA method, viral load by PCR amplification and HBV S gene by phylogenetic analysis. RESULTS: 102 pairs of subjects were followed-up. Blood samples from 94 mothers and 101 children were collected. OBI prevalence in mothers was 10.0% (6/60), significantly higher than 2.0% (2/101) in teenagers. Medians of viral load were 399.9 IU/ml and 247.6 IU/ml in overt and occult HBV strains, but without significant difference. 1 occult HBV strain belonged to genotype B with serotype adw while the other 7 were genotype C with serotype adr. 15 of the overt HBV strains belonged to genotype B with serotype adw and the other 8 were genotype C with serotype adr. Proportions of genotype-C strains were significantly higher in occult HBV strains than in overt HBV strains. CONCLUSION: OBI was seen in teenage-mother population.