Detection and analysis of lung microbiota in mice with lung cancer lacking the NLRP3 gene.

To explore whether the lung microbiota have changed in the process of NLRP3 inflammasome promoting cancer, we constructed a murine lung cancer model using tracheal instillation of benzo(a)pyrene and an equal volume of tricaprylin, and characterized lung microbiota in bronchoalveolar lavage fluid from 24 SPF wild-type and NLRP3 gene knockout (NLRP3-/-) C57BL/6 mice. 16SrDNA sequencing was used to analyze the changes in the microbiota. The wild-type and the NLRP3-/- lung cancer group had statistically significant differences in tumor formation rate, tumor number, and tumor size. At the phylum and the genus level, the relative abundance of Proteobacteria and Sphingomonas were the highest in each group respectively. Simpson (P = 0.002) and Shannon (P = 0.008) indexes showed that the diversity of microbiota in the lung cancer group was lower than that in the control group under the NLRP3-/- background. According to the ANOSIM and MRPP analysis, there was a difference between the NLRP3-/- lung cancer group and the NLRP3-/- control group (P < 0.05). The knockout of the NLRP3 gene caused changes in the lung microbiota of mice. There may be a regulatory relationship between the NLRP3 inflammasome and the lung microbiota, which affects the occurrence and development of lung cancer.

Prevalence of depression among Chinese university students: a systematic review and meta-analysis.

Estimates of the depression prevalence among Chinese university students vary considerably across studies. This systematic review and meta-analysis aimed to comprehensively analyze the depression prevalence among Chinese university students. We searched four electronic databases with the search terms of depression, China, university student, and questionnaire. Studies reporting depression among Chinese university students were included in the analysis. Two reviewers independently extracted the data and assessed the qualities of the studies. The package of "meta" in R Foundation for Statistical Computing was used to calculate an overall proportion in a random-effects model with 95% confidence intervals. Subgroup analysis was conducted to analyze the influencing factors on the depression prevalence. Any conflict in the data analysis was discussed by all the reviewers. A total of 113 studies were included in the meta-analysis. The overall prevalence of depression among Chinese university students was shown to be 28.4% (n = 185,787), with 95%CI from 25.7 to 31.2%. The overall depression prevalence among Chinese university students was still relatively high. More efforts need to be done to provide better mental healthcare to university students in China.

The effect of different tobacco tar levels on DNA damage in cigarette smoking subjects.

OBJECTIVE: To explore the genetic damage caused by different tar levels in the human body. METHODS: The subjects were divided into high, medium and low (12 mg, 8 mg, 5 mg) tar groups according to the tar levels. Nonsmoking populations served as a control group. 2 ml of peripheral blood was collected on the 10th day after morning fasting. Oxidative and genetic toxicological damage indicators were analysed with enzyme-linked immunosorbent assay, cytokinesis-block micronucleus assay in human lymphocyte and single cell gel electrophoresis. RESULTS: The distribution of hOGG1 concentration was significantly different within all groups, P < 0.01. The concentrations of cotinine, 8-OHdG and Rap-2b were significantly differences between control and medium tar group, control and high tar group, low and medium tar group and low and high tar group, respectively, P < 0.05. The level of PAH-DNA adducts was not significantly changed in the middle tar group and high tar group, P > 0.05. The level of CRP was significantly changed between control and high tar group, low and high tar group and medium and high tar group, respectively, P < 0.0001. The rate of comet tailing was significantly different between all groups. The rate of micronucleus cells was not significantly different between all groups. CONCLUSIONS: The increase of tar content could increase the DNA damage to a certain extent, so the intake of tar content should be monitored.

Family-based Association between Allele T of rs4646536 in CYP27B1 and vitamin D deficiency.

BACKGROUND: The circulating concentration of 25(OH)D is widely applied to indicate the vitamin D status, as the directly metabolic genes of 25(OH)D, CYP2R1, and CYP27B1 are associated with the concentration of 25(OH)D. However, the contributions of allelic transmission disequilibrium of single nucleotide polymorphisms (SNPs) in these genes to vitamin D deficiency remain unclear. We aimed at investigating the family-based association between SNPs of CYP2R1 and CYP27B1 and vitamin D deficiency. METHOD: First, SNPs selected in family-based study were screened by a pilot case-control study. Second, allelic transmissions of the selected SNPs were investigated with family-based study (n = 880). Finally, associations between selected SNPs and the concentration of 25(OH)D were verified in siblings (n = 120). RESULTS: The results of the pilot case-control study indicated that both CT and TT genotypes of rs4646536 in CYP27B1 could increase the susceptibility of vitamin D deficiency when compared with CC genotype. The adjusted ORs were 2.846 (95%CI 1.312-6.174, P = 0.008) and 2.609 (95%CI 1.197-5.687, P = 0.016), respectively. Furthermore, the results of family-based association test suggested that there was transmission disequilibrium for allele T of rs4646536 in vitamin D deficiency families. In addition, the concentration of 25(OH)D3 for CC genotype was higher than CT genotype between siblings (P = 0.016). CONCLUSIONS: Transmission disequilibrium of allele T of rs4646536 is associated with vitamin D deficiency.