Research progress in epigenetic toxicity of diesel exhausts / 环境与职业医学

Diesel exhaust (DE) can enter the organism body and cause multiple organ damage. DE contains particles that can be suspended in the air for a long time. Epigenetic regulation is a post transcriptional regulation change that does not involve DNA sequence changes. Many evidences showed that DE can affect the normal physiological functions of multiple organs and systems through epigenetic changes, thus regulating the occurrence and development of multiple diseases. This paper reviewed the research progress of DNA methylation and non-coding RNA in the biological harmful effects of DE. This will provide a basis for the safety evaluation, health risk assessment, and management of DE.

Prevalence and associated factors of electronic products usage among primary school students of grade 4-6 in Beijing / 中国学校卫生

Objective@#To explore the prevalence and associated factors of non learning-based screen time of 4-6 grade school students in Beijing, and to provide a basic data for further research on hazard control measures such as myopia, overweight and obesity among children and adolescents in Beijing.@*Methods@#Multistage stratified random cluster sampling method was adopted. A total of 2 515 primary school students were randomly selected in from schools in Beijing, self-developed questionnaire was used to investigate on the time for each electronic products usage for non-learning purpose, the total of electronic products usage every day and other information.@*Results@#The rates of screen time >15 minutes each time and ≥1 h daily were 48.43%, 22.90%, respectively. Multiple Logistic regression analysis showed that ordinary school, 6 th grade, male, single-parent family and other types of family, and lack of moderate-to-vigorous physical activity at weekend were associated with the students’ non learning-based screen time (OR=1.66, 2.28, 1.27, 1.44, 1.87, 2.20, P<0.05).@*Conclusion@#The situation of excessive screen time of primary school students was improved in Beijing, but still be prevelent, male students of grade 4 should be given more attention, and more importance should be attached to the offect of family in children.

Molecular cloning and functional identification of sterol C24-methyltransferase gene from

Sterol C24-methyltransferase (SMT) plays multiple important roles in plant growth and development. SMT1, which belongs to the family of transferases and transforms cycloartenol into 24-methylene cycloartenol, is involved in the biosynthesis of 24-methyl sterols. Here, we report the cloning and characterization of a cDNA encoding a sterol C24-methyltransferase from().(GenBank access number KU885950) is a 1530 bp cDNA with a 1041 bp open reading frame predicted to encode a 346-amino acid, 38.62 kDa protein. The polypeptide encoded by thecDNA was expressed and purified as a recombinant protein from() and showed SMT activity. The expression ofwas highly up-regulated incell suspension cultures treated with methyl jasmonate (MeJA). Tissue expression pattern analysis showed higher expression in the phellem layer compared to the other four organs (leaf, stem, xylem and phloem), which is about ten times that of the lowest expression in leaf. The results are meaningful for the study of sterol biosynthesis ofand will further lay the foundations for the research in regulating both the content of other main compounds and growth and development of

Effect of estradiol on proliferation of rat hippocampal neural stem cells / 解剖学报

Objective The aim is to observe the role and mechanism of estradiol ( E2 ) on the proliferation of rat hippocampal neural stem cells ( NSCs ) .Methods Twenty hippocampi from embryonic 17-day ( E17 ) SD rats were dissociated and plated into culture flasks with NSCs specific medium containing different concentrations of estradiol .The proliferation and the vitality of NSCs were detected by immunofluorescence against BrdU and MTT assay .The expression of estrogen receptors ( ERαand ERβ) was measured by immunofluorescence staining combined with Nestin double labeling . Results BrdU and MTT assay results showed that the cell number increased when the concentration of estradiol increased from 10 -10 to 10 -8 mol/L.The number of cell proliferation and the viability of cells were best at the concentration of 10 -8 mol/L compared to the other groups .However, when the estradiol concentration was increased from 10-8 to 10 -6 mol/L, the cell proliferative capacity declined gradually .Double immunofluorescence labeling showed that the two types of estrogen receptors ( ERαand ERβ) were expressed in the cultured hippocampal NSCs .Conclusion Estradiol promotes the proliferation of hippocampal NSCs in a certain concentration range , and ERαand ERβmay be involved in the estradiol-induced proliferation .

Role of PARP-1 in formaldehyde-induced DNA damage repair and apoptosis in human bronchial epithelial cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the role of poly (ADP-ribose) polymerase-l (PARP-1) in formaldehyde-induced DNA damage response in human bronchial epithelial (HBE) cells and to investigate the mechanism of formaldehyde carcinogenicity.</p><p><b>METHODS</b>The protein levels were measured by Western blot. The interaction between different proteins was determined by co-immunoprecipitation assay. The chemical inhibitor was used to confirm the relationship between PARP-1 and DNA damage repair.</p><p><b>RESULTS</b>After being exposed to different concentrations of formaldehyde for 4 h, HBE cells showed no significant changes in cell viability. Cell viability was significantly reduced after 24-h exposure to 80 and 160 µmol/L formaldehyde (P < 0.05). The 10 µmol/L formaldehyde resulted in significant increases in the protein levels of PARP-1 and XRCC-1. However, 80 µmol/L formaldehyde led to a significant decrease in the protein level of PARP-1 of 124 KD molecular weight but a significant increase in the protein level of PARP-1 of 89 KD molecular weight; there was no significant change in the protein level of XRCC-1. The co-immunoprecipitation assay showed that 10 µmol/L formaldehyde induced increased binding between PARP-1 and XRCC-1, but 80 µmol/L formaldehyde led to no significant change in binding between PARP-1 and XRCC-1. Here, we confirmed the role of 10 µmol/L formaldehyde in strand breaks by comet assay which showed an increase in the tail DNA content of HBE cells after 4-h formaldehyde exposure. No significant difference was observed in tail DNA content between treated HBE cells and control cells at 2 h after formaldehyde was removed. Moreover, compared with control, inhibition of PARP-1 induced a significant increase in tail DNA content, and a significant difference was observed in tail DNA content between inhibited HBE cells and control cells at 2 h after formaldehyde was removed. Inhibition of PARP-1 significantly reduced DNA repair capacity.</p><p><b>CONCLUSION</b>PARP-1 mediated the repair of DNA damage induced by low-concentration formaldehyde through recruiting XRCC-1 protein, and may be involved in the regulation of cell apoptosis induced by high-concentration formaldehyde.</p>

The effects of ceruloplasmin in PI3K/PTEN cell signaling pathway change induced by silica / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the roles of ceruloplasmin (Cp) in PI3K/PTEN cell signaling pathway change in human embryonic lung fibroblasts (HELFs) induced by silica.</p><p><b>METHODS</b>HELFs transfected with pGenesil1.1 plasmid and pGenesil1.1 with PTEN shRNA (PT) plasmid were successfully established. 100 µg/ml silica and different concentrations of Cp (10, 20, 30 µg/ml) were used in this experiment and Cp were treated cells after exposed to silica for 1h. Three different cell lines (including HELFs, PT and cells were transfected with p85 dominant negative mutant plasmid (DN-p85)) were divided into control groups, silica groups and silica+different concentrations of Cp groups. MTT assay was used to detect the effects of Cp on silica-induced cell proliferation after inhibiting PTEN and p85. When suppressing the expression of PTEN and p85, western blot assay was performed to detect the levels of p85, p110, AKT308, AKT473 and ERK, JNK and their phosphorylated levels.</p><p><b>RESULTS</b>After inhibition of PTEN, the high levels of p85 induced by 100 µg/ml silica with 30 µg/ml Cp were markedly decreased (P<0.05). When suppressing p85, the increased cell proliferation was not observed. And the high levels of AKT308, AKT473, ERK and phosphorylated JNK and ERK stimulated by 100 µg/ml silica with 30 µg/ml Cp were decrease (P < 0.05).</p><p><b>CONCLUSION</b>Cp could further strengthened silica-induced cell proliferation by PI3K/AKT/MAPK cell signaling pathway, of which the level of p85 was regulated by PTEN.</p>

Clinical application of skin expansion with easily self-controlled and continuous constant pressure / 中华医学美学美容杂志

Objective To study the effects of a self-controlled and totally-enclosed type perfusion skin and tissue expansion in which pressure was continuous and constant. Methods Totally-enclosed type perfusion system included single-used infusion apparatus, triplet, soft water storage bag, catheter, and common expander. Continuous pressure-constant system included inflatable infusion apparatus and common spring sphygmomanometer. Expander was filled from soft water storage bag which was put in inflatable infusion apparatus by crushed ball. The pressure of expander was controlled by patients according to pain threshold. 26 expanders were used in 20 patients in clinical practice. The volume of expander was about 100 ~ 400 ml. After 3~5 days from operation, water began to fill in the expander and stopped when the expansion area reached. Results The volume of expander was 120~640 ml and the duration of expansion was 10~16 days, average (13.6? 2.1) days, without any complication. Conclusions The tissue expansion with continuous and constant pressure and totally-enclosed perfusion is worth popularizing because of its easy preparation, simply operation, rapid expansion, safety and comfort.