Objective To study a gastric carcinoma subcell line with higher invasive potential and its biologic characteristics screened by a transwell chamber. Methods Transwell chamber was used for the selection of tumor subline. The biological characteristics of the cell lines were studied with optics microscope, Westem blotting, Transwell, immunohistochemical staining and growth curve. Results A gastric carcinoma cell subcell line (named MKN-28S10) was established from its parent cell line MKN-28 with higher invasive potential. MKN-28S10 showed essentially the same morphous as MKN-28. The expression of E-cadherin and TIMP-1 decreased significantly in the screened subcell line(P<0.05). The expression of NM23-H1 in MKN-28S10 was significantly lower than that in MKN-28 (P<0.05). Compared with MKN-28 (61.75±2.06 per vision), the migrative ability of passing through the membrane Millipore(100.25±0.50 per vision) was obviously increased in MKN-28S10(P<0.05). Compared with MKN-28, the growth rate of MKN-28S10 was increased obviously. Conclusion MKN-28S10 cell has stronger invasive ability and more powerful proliferation than that of its mother line MKN-28.

Objective To investigate the role of CD4 ~+ CD25~+ regulatory T lymphocytes (Treg)in modulating the cellular immune response and pathogenesis of murine pulmonary tuberculosis.Methods Inactivation of Treg was achieved by intraperitoneal injection anti-CD25 (clone PC61,50 μ/mouse) in PC61 group, and rat-IgG (50 μ/mouse) was injected intraperitoneally in control group. All the mice were inoculated intravenously with H37Rv 0. 1 mL (1 × 10~6 CFU) 3 days after Treg inactivation. The effects of Treg inactivation in different tissues were analyzed by flow cytometry. The cellular immune response, pulmonary histopathology and bacterial load were determined in vitro at different time points. The data were compared using homogeneity of variance F test and non-paired t test. Results In spleen, the percentages of Treg/CD4 T lymphocytes in PC61 group and control group were (21. 13± 3. 58)% and (30. 42± 4. 20)%, respectively at day 10 of inoculation (t = 2. 38, P < 0. 05), and those were (16. 12 ± 1. 26)% and ( 17. 34± 1. 62)%,respectively at day 30 of inoculation (t = 0. 84,P>0. 05). The percentages of Foxp3~+/CD4~+ T lymphocytes in PC61 group and control group were (32. 07 ± 3. 95)% and (60. 55 ± 5. 48)%,respectively at day 10 of inoculation (t = 5. 96, P<0. 05). Similar results were achieved in the peripheral blood. Bacillus calmette-guerin (BCG)-specific 1L-17 (ng/L) secreted by murine spleen cells in PC61 group and control group at day 10, 30 and 60 of inoculation were 5. 1± 0.9 vs 0, 43. 1± 10.0 vs5. 9± 2. 8 and 124.8 ± 5.8 vs 102. 5±8. 1, respectively (t = 7. 90, t=5. 10,t = 3. 19; all P<0.05); those of BCG-specific IFN-γ (ng/L) were 28. 4 ± 8. 2 vs 4. 0±1. 3, 685. 9± 128. 6 vs418. 7±20.4 and 310.9±119. 7 vs 32. 8±7. 5, respectively(tO = 4. 21,t = 8. 43, t = 3. 27; all P<0.05);those of TNF-a (ng/L) were 38. 6±5.0 vs 16. 3±4. 0, 112. 9 ±12. 3 vs 71. 5±12. 6 and 86. 2±8. 2vs0, respectively(t = 4. 95, t=3. 33,t/=14.8; all P<0. 05). The lung bacterial load at day 10 of inoculation in PC61 group was lower than that in control group (t = 4. 63, P < 0. 01), but the differences were not significant thereafter. The changes of lung histopathology at late stage of infection (day 120) in PC61 group were less severe than those in control group. Conclusions Murine Tregs increase dramatically after Mycobacterium tuberculosis infection. Treg could inhibit the specific cellular immunity against Mycobacterium tuberculosis, and therefore, may facilitate the persistent infection of Mycobacterium tuberculosis and development of tuberculosis.

Objective To evaluate the effectiveness of an activity of nutrition science experience on nutrition and food safety cog-nition among primary and secondary school students .Methods With stratified cluster sampling ,students of grade 5 and 6 in one primary school and students of grade 1 and 2 in one middle school in Chongqing were selected ,and randomly divided into interven-tion group(n= 501) and control group(n= 522) .Only conducted the activity in the intervention group .Baseline data of all the students were investigated before the intervention .Effect evaluation was performed instantly in the intervention group and control group ,and a follow-up survey carried out in the intervention group after 9 months(n= 472) .Results The nutrition knowledge scores of instant intervention group were 9 .03 ± 2 .75 and 14 .70 ± 3 .28 before and after intervention respectively (U=29 .78 ,P<0 .01);the knowledge scores of the nine months later intervention group were 12 .35 ± 2 .89 ,which were lower than instant interven-tion group(U=12 .40 ,P<0 .01) ,but higher than before intervention(U=18 .04 ,P<0 .01) .The food safety scores of instant inter-vention group ,which were higher than control group ,nine months later intervention group and before intervention(P<0 .01) .Con-clusion It is feasible and effective to conduct a nutrition science experience among primary and secondary school students .

Objective The staffs of biosafety level 3 laboratories (BSL-3) face with the stress of handling highly pathogenic microbs and special laboratory environment.The job stress may result in accidents in the laboratory as negative factor for the risk control.The research may provide support for the control of risk in biosafety laboratories.Methods In order to assess the job stress in the staff in BSL-3 laboratory, we modified “the Chinese simple job stress questionnaire”based on the theory of the JDC mode and ERI mode, and an investigation was carried out.The present study included the staffs (87 employees) from six BSL-3 laboratories located in five provinces ( Shanghai, Zhejiang, Jiangsu, Fujian and Wuhan) .Results Analysis of the data indicates that variables of age, working years, job duties, manipulating of animals, type of microorganisms and transmission route have a significant influence on the level of job stress in BSL-3 laboratory.Conclusion The BSL-3 laboratory staff in higher stress level have the characteristicses:20-39 years old, short work years, regular staff, operating on air-borne microbiology, manipulating of animals and operating on one more microbiology.