The effects of methionine and choline on the expression levels of CaMKII and CREB mRNA and proteins in rats exposed to lead / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of methionine and choline on the expression levels of CaMKII and CREB mRNA and proteins in hippocampus of rats exposed to lead.</p><p><b>METHODS</b>Male SD rats were divided into five groups. (1) control group, (2) group exposed to lead+2 by drinking water with 0.40 g/L lead acetate, (3) group exposed to methionine and choline (1:1, 400 mg/kg), (4) group exposed to 0.40 g/L lead acetate plus methionine and choline (1:1, 100 mg/kg), (5) group exposed to 0.40 g/L lead acetate plus methionine and choline (1:1, 400 mg/kg). In 8 weeks after exposure, all rats were killed. Then CREB mRNA and CaMK II mRNA expression levels in hippocampus were detected by real-time PCR, CREB and CaMK II protein expression levels in hippocampus were measured by western blot assay.</p><p><b>RESULTS</b>The expression levels (0.743 ± 0.185 and 0.729 ± 0.199) of CaMKII mRNA and CREB mRNA in the hippocampus of lead group were significantly lower than those (0.950 ± 0.238 and 0.901 ± 0.232) of control group (P < 0.05), also the expression levels (0.271 ± 0.045 and 0.212 ± 0.058) of CREB protein and pCREB protein in the hippocampus of lead group were significantly lower than those (0.319 ± 0.058 and 0.506 ± 0.125) of control group (P < 0.05). The expression levels (1.014 ± 0.210 and 1.126 ± 0.379) of CaMKII mRNA and the expression levels (1.029 ± 0.335 and 0.932 ± 0.251) of CREB mRNA in the hippocampus of 2 groups exposed to lead acetate plus methionine and choline were significantly higher than those of lead group (P < 0.05). The expression levels (0.407 ± 0.951 and 0.563 ± 0.178) of CREB protein and pCREB protein in the hippocampus of group exposed to lead acetate plus 400 mg/kg methionine and choline were significantly higher than those of lead group (P < 0.05).</p><p><b>CONCLUSION</b>Methionine and choline could decrease the inhibition effects of lead on the expression of CaMKII and CREB mRNA or CREB and pCREB proteins in the hippocampus of rats.</p>

Study on mental workload of teachers in primary schools / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the distribution characteristics and influencing factors of mental workload of teachers in primary schools.</p><p><b>METHODS</b>National Aeronautics and Space Administration-Task Load Index (NASA-TLX) was used to assess the mental workload levels for 397 teachers of primary schools in a city.</p><p><b>RESULTS</b>The mental workload (64.34+10.56) of female teachers was significantly higher than that (61.73+ 9.77) of male teachers (P<0.05). The mental workload (65.66+10.42) of "-35" years old group was the highest. When age of teachers was younger than 35 years old, there was a positive correlation between the mental workload and age (r=0.146, P<0.05). When age of teachers was older than 35 years old, there was a negative correlation between the mental workload and age (r=-0.190, P<0.05). The teachers with higher education level felt higher mental workload (unstandardized coefficients B=1.524, standardized coefficients /=0.111, P<0.05). There was a positive correlation between the mental workload and working hours per day (unstandardized coefficients B =4.659, standardized coefficients/3 =0.223, P<0.001).</p><p><b>CONCLUSION</b>Mental workload of the teachers in primary schools is closely related to age, educational level and work hours per day. Work hours per day is an important risk factor for mental workload. Reducing work hours per day (8 hours) is an effective measure of alleviating the mental workload of teachers in primary schools.</p>

Study on Mental Characteristics of Children's with Light Lead Poisoning / 实用儿科临床杂志

Objective To study mental characteristics of children with light lead poisoning. Methods Eighty - six children with light lead poisioning and 33 control children were evaluated with WISC - R and social adaptive capacity(SAB). Results 1. Intelligence quotient( IQ)and SAB of children with light lead poisoning were lower than normal children. 2. There was also deficiency of perception factor and memory/ concentration factor among children with lead poisioning and the blood lead level had negative association with perception factor. Conclusion Light lead poisioning may affect children's IQ, especially in the perception factor and memory /concentration factor.

Effects of Thulium Exposure on IQ of Children / 环境与健康杂志

Objective To study the effects of environmental exposure to rare earth elements REEs on intelligence of children. Methods Intelligence quotient IQ were examined with Drawing a Man Test in 464 children aged 7-10 years living in RE ore containing area and the control area in Xunwu country Jiangxi province China. Fifteen kinds of REEs in 112 blood samples 69 samples from RE ore area and 43 samples from the control area  were detected by inductively coupled plasma source mass spectrometry ICP-MS. Results All 15 kinds of REEs were detected in each sample the content of blood REEs of the children in the rare earth area 2.18?1.08 ng/g was 1.73 times of that of the children in the control area 1.26?0.35 ng/g the difference was significant P