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Objective To investigate the effect of 1 800 MHz electromagnetic radiation on activity of SOD and GSH－Px in the skin tissues of SD rats.Methods A total of 98 healthy SD rats with SPF level,aged 4 weeks, were randomly divided into radiation group and control group.The radiation group was totally exposed under 1 800 MHz electromagnetic wave with seven different power density of radiation of 0.1 mW/cm2,0.3 mW/cm2,0.5 mW/cm2 , 0.7 mW/cm2, 0.9 mW/cm2, 1.0 mW/cm2and 1.2 mW/cm2respectively.It lasted 21 days and for a period of 12 hours a day. After radiation,the activity of SOD and GSH－Px in the skin tissues were detected by enzyme marker. Results In radiation group,the activity of SOD and GSH－Px in the skin tissues of SD rats were decreased under 0.3 mW/cm2and 0.5 mW/cm21 800 MHz electromagnetic wave. Compared with the control group, there was a significantly difference in radiation group (P＜0.05) .While under other four 1 800 MHz electromagnetic waves, the activity of GSH－Px and SOD in the skin tissues showed no statistical difference between the two groups (P＞0.05) . Under 1 mW/cm21 800 MHz electromagnetic wave, the activity of GSH－Px showed no statistical difference between two groups (P＞0.05) . Conclusion The power density of 0.3 mW/cm2and 0.5 mW/cm21 800 MHz electromagnetic wave can reduce the activity of GSH－Px and SOD in the skin tissues of rats.
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Objective To explore the potential correlation between fluoride levels of urine and influencing factors in water-high-fluoride areas.Methods In 2010,based on plain area,mountainous area and mixed area (altitudes were 898,2 200,1 460 m,respectively),3 villages of water-high-fluoride areas were selected by purpose sampling;pupils' family members were selected as survey population by cluster sampling.Questionnaire was conducted to collect general information;fluoride contents in urine and drinking water were measured using ionselective electrode.A linear multiple regression was used to examine which factors affected urinary fluoride.Results Totally there were 968 people distributed in plain area (444),mixed area (368) and mountainous area (156),medians of urinary fluoride level were 0.71,1.59 and 1.67 mg/L,respectively,the difference was significant (F =203.90,P ＜0.01);medians of water fluoride level in the three different habitats were 0.50,1.00 and 3.50 mg/L,respectively,the difference was significant (F =331.98,P ＜ 0.01).Age,gender,fluoride contents in drinking waters and habitat explained 33.1％ of urinary fluoride variation.Male had higher urine fluoride than female,older age and higher level fluoride in drinking water contributed to higher fluoride level in urine,higher altitude contributed to higher urinary fluoride.Conclusion Once fluoride content in urine is used to estimate fluoride exposure level among people in high fluoride area,gender and age must be taken in consideration.
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Objective To express the plasminogen activator(Pla) of Yersinia pestis and one of its gene fragments,and to detect their immunological reactivity.Methods The pla gene and its specific gene fragment pla-c were amplified by PCR using the EV76 strain as a template.PCR products were then ligated with the plasmid pET32a (+).The recombinant plasmids pET32a (+)-pla and pET32a (+)-pla-c were subsequently trausformed into E.coli BL21 (DE3).The expressed products were purified by HIS affinity chromatography,and their immunological reactivity was detected by Western blotting.Results The recombinant Pla(52.8 × 103) was expressed as inclusion bodies,and the recombinant Pla-c protein (24.0 × 103) was expressed in the soluble form.These two recombinant proteins reacted with anti-Yersinia pestis EV76 rabbit sera.Conclusions The recombinant Pla and its specific fragments have displayed immunological reactivity,and can be served as an alternative diagnosis method for Yersinia pestis.
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<p><b>OBJECTIVE</b>To identify the effects of NMDA receptor subunits NR2A and NR2B expression in rat's hippocampus after exposure to 1800 MHz radiofrequency radiation.</p><p><b>METHODS</b>Four-week old female Wistar rats were randomly divided into four groups, with 12 animals for each. The subjects in two experimental groups had been continuously exposed to 1800 MHz microwave radiation (CW) with respective power density of 0.5 mW/cm(2) and 1.0 mW/cm(2) 12 hours each day for 21 days. Meanwhile, sham-controls were carried out. The brain tissue sections were performed by immunohistochemistry to demonstrate both expressions of NR2A, NR2B immune-activity in the hippocampal CA1, CA3 and DG by using computer-assisted image analysis system.</p><p><b>RESULTS</b>In NR2A: the expression of 0.5 mW/cm(2) power density group was significantly lower than 0 mW/cm(2) power density group in CA3 [(8.5 +/- 1.5) vs (11.1 +/- 1.8), P < 0.01] and had not been significantly changed in CA1 and DG. The expression of 1.0 mW/cm(2) power density group was significantly lower than 0 mW/cm(2) power density group in CA1 and CA3 [(7.9 +/- 1.6) vs (9.7 +/- 1.5); (8.4 +/- 1.7) vs (11.1 +/- 1.8), respective P < 0.05, P < 0.01] and had not been significantly changed in DG. In NR2B: the expression of 0.5 mW/cm(2) power density group was significantly lower than 0 mW/cm(2) power density group in CA1 and CA3 [(16.4 +/- 1.0) vs (17.8 +/- 1.6); (9.6 +/- 1.9) vs (11.2 +/- 2.1), respective P < 0.05]. The expression of 1.0 mW/cm(2) power density group was significantly lower than 0 mW/cm(2) power density group in CA1, CA3 and DG [(13.1 +/- 2.4) vs (17.8 +/- 1.6); (9.3 +/- 1.4) vs (11.2 +/- 2.1); (7.3 +/- 0.1) vs (8.5 +/- 1.0), respective P < 0.01, P < 0.05, P < 0.05].</p><p><b>CONCLUSION</b>There were findings of the effects on NMDA receptor subunits in different hippocampus sections after exposure to 1800 MHz radiofrequency radiation.</p>