Role of DNMT3a in Hydroquinone-Induced Hematopoietic Stem Cell Toxicity / 中国实验血液学杂志

OBJECTIVE@#To investigate the regulatory effect and mechanism of DNA methyltransferase 3A (DNMT3a) in hydroquinone-induced hematopoietic stem cell toxicity.@*METHODS@#Cells (HSPC-1) were divided into 4 groups, that is A: normal HSPC-1; B: HQ-intervented HSPC-1; C: group B + pcDNA3 empty vector; D: group B + pcDNA3- DNMT3a. RT-qPCR and Western blot were used to detect the expression levels of DNMT3a and PARP-1 mRNA and protein, respectively. Cell morphology was observe; Cell viability and apoptosis rate of HSPC-1 were detected by MTT and flow cytometry, respectively.@*RESULTS@#Compared with group A, the expression levels of DNMT3a mRNA and protein in HSPC-1 of group B were decreased, while PARP-1 mRNA and protein were increased (P<0.05); there was no significant difference in the above indexes between group C and group B; compared with group B, the expression levels of DNMT3a mRNA and protein showed increased, while PARP-1 mRNA and protein were decreased significantly in cells of group D transfected with DNMT3a (P<0.05). Cells in each group were transfected with DNMT3a and cultured for 24 h, HSPC-1 in group A showed high density growth and mononuclear fusion growth, while the number of HSPC-1 in group B and C decreased and grew slowly. Compared with group B and C, the cell growth rate of group D was accelerated. The MTT analysis showed that cell viability of HSPC-1 in group B were lower than that of group A at 24 h, 48 h and 72 h (P<0.05); after transfected with DNMT3a, the cell viability of HSPC-1 in group D were higher than that of group B at 24 h, 48 h and 72 h (P<0.05). The apoptosis rate of cells in group B was significantly higher than that of group A (P<0.001), while the apoptosis rate in group D was lower than that of group B (P<0.001).@*CONCLUSION@#DNMT3a may be involved in the damage of hematopoietic stem cells induced by hydroquinone, which may be related to the regulation of PARP-1 activity by hydroquinone-inhibited DNMT3a.

Body mass index, waist circumference, and risk of hearing loss: a meta-analysis and systematic review of observational study

BACKGROUND@#Emerging evidence implicates excess weight as a potential risk factor for hearing loss. However, this association remained inconclusive. Therefore, we aimed to systematically and quantitatively review the published observational study on the association between body mass index (BMI) or waist circumference (WC) and hearing loss.@*METHODS@#The odds ratios (ORs) or relative risks (RRs) with their 95% confidence intervals (CIs) were pooled under a random-effects model. Fourteen observational studies were eligible for the inclusion in the final analysis.@*RESULTS@#In the meta-analysis of cross-sectional studies, the ORs for prevalent hearing loss were 1.10 (95% CI 0.88, 1.38) underweight, 1.14 (95% CI 0.99, 1.32) for overweight, OR 1.40 (95% CI 1.14, 1.72) for obesity, 1.14 (95% CI 1.04, 1.24) for each 5 kg/m increase in BMI, and 1.22 (95% CO 0.88. 1.68) for higher WC. In the meta-analysis of longitudinal studies, the RRs were 0.96 (95% CI 0.52, 1.79) for underweight, 1.15 (95% CI 1.04, 1.27) for overweight, 1.38 (95% CI 1.07, 1.79) for obesity, 1.15 (95% CI 1.01, 1.30) for each 5 kg/m increase in BMI, and 1.11 (95% CI 1.01, 1.22) for higher WC.@*CONCLUSIONS@#In summary, our findings add weight to the evidence that elevated BMI and higher WC may be positively associated with the risk of hearing loss.

Study on Immobilization of Petroleum Biodesulfurization Catalyst Agrobacterium tumefaciens UP-3 / 微生物学通报

Immobilization of the bacterium Agrobacterium tumefaciens UP-3 was studied in this paper. The results showed that the immobilized cells with the mixture of polyvinyl alcohol (PVA) and sodium alginate (SA) as the immobilizing carrier had good biodesulfurization characteristics; The optimum operation immobilization conditions were 4℃, the total concentration of PVA and SA being 7%(wt), and the concentration of cells being 0.05 g/mL. When DBT addition was 2.7 mmol/L, the DBT degradation of immobilized cells was above 60% while that of resting cells is 13%. The optimum degradation time and temperature of immobilized cells were 5d and 28℃～32℃, respectively.

Isolation of Biodesulfurization Bacteria Pseudomonas stutzeri UP-1 for Petroleum / 微生物学通报

Dibenzothiophene (DBT) was used as a model compound. A bacteria strain, which can degrade dibenzo-thiophene efficiently, was obtained. This strain was identified as Pseudomonas stutzeris UP-1 according to its morphological, physiological and biochemical characters, and 16S rDNA sequence. The strain exhibits strong degradation capacity of DBT, and the end product of degradation is a kind of soluble compound. After the analysis of product of DBT degradation, it was deduced that the degradation of DBT by Pseudomonas stutzeri UP-1 is in accordance with the Kodama mechanism.