Within-day variation and health risk assessment of trihalomethanes (THMs) in a chlorinated indoor swimming pool in China.

Trihalomethanes (THMs) are the most common species of disinfection by-products (DBPs) in swimming pools and have received widespread attention due to their risk to public health. However, studies examining within-day variation and the carcinogenic health risks from exposure to THMs in indoor swimming pools are limited. Our study aimed to detect the within-day variation of four THMs categories and carcinogenic health risk in indoor swimming pool water in Taiyuan, China, and to examine the correlations between THMs and environmental parameters. Our results showed chloroform (TCM) was the most abundant component in THMs with median concentrations from 0.038-0.118 µg/m3. TCM and THMs were significantly positively correlated with FCl and significantly negatively correlated with the cumulative number of swimmers (CNS) in the swimming pool. The concentration of total THMs and TCM, lifetime average daily doses (LADD) of TCM, and the total lifetime cancer risks (ELCR) values of THMs declined with time with the highest level occurring at 8:00 am. ELCR values of THMs were in the range of 1.368 × 10-5-1.968 × 10-5, which exceeded the negligible risk level (10-6) defined by US EPA. Our results suggest that THM occurrence and the carcinogenic health risks in pool water varied temporally. Exposure to pool water THMs may pose a carcinogenic risk to human health, especially at the pool's opening time.

Knockdown of α-enolase (Eno1) genes by RNAi does not increase the sensitivity of Propsilocerus akamusi to cadmium stress.

α-enolase (Eno1) is a multifunctional enzyme which can as a stress protein under various environmental stresses. Recent researches also reported that Eno1 appears to have Cd2+ stress-related functions in cadmium tolerant plants. Our previous study inferred that the Eno1 gene might play an important role in the response of Propsilocerus akamusi to exogenous Cd2+. However, reports on the role of the Eno1 gene in coping with cadmium stress are still limited. In this study, we evaluated the roles of PaEno1 in the tolerance of P. akamusi to Cd2+ using RNAi technology and the response of recombinant proteins of PaEno1 in an E. coli expression system under Cd2+ stress. Our results showed that knockdown of PaEno1 did not increase but reduce the sensitivity of P. akamusi larvae to Cd2+ stress. However, bioassays showed the expression of recombinant PaEno1 protein in Rosetta cells enhanced the growth ability of E. coli under Cd2+ stress. These results suggested that overexpression of PaEno1 can significantly enhance the tolerance to heavy metal cadmium stresses in E. coli cells. However, knockdown of PaEno1 genes by RNAi does not increase the sensitivity of P. akamusi to cadmium stress.

Changes in the gut microbiota of honey bees associated with jujube flower disease.

Honeybees are prone to poisoning after collecting jujube nectar during the jujube flowering period ('honeybee's jujube flower disease'). To explore the mechanism of honeybee poisoning, the gut microbiota of honeybees undergoing the disease were characterised based on amplicon sequencing of the 16 S rRNA gene. Our results showed that the composition and diversity of the gut microbiota were significantly altered in diseased honeybees. We observed a decrease in the relative abundance of Proteobacteria and increased abundances of Firmicutes and Actinobacteria in the midgut and hindgut of diseased honeybees. Moreover, linear discriminant analysis (LDA) effect size revealed significantly selected enrichment of Fructobacillus and Snodgrassella in the midguts from diseased honeybees and Lactobacillus, Bifidobacterium, and Snodgrassella in the hindguts from diseased honeybees. Tax4Fun anylasis indicated that the functional potential of the diseased honeybee gut bacterial community was significantly changed relative to the healthy honeybee. Carbohydrate metabolism, nucleotides metabolism, amino acid synthesis metabolism, coenzyme and vitamins metabolism were increased, while energy metabolism and xenobiotic biodegradation and metabolism were decreased in the diseased honeybees. These results provide a new perspective for evaluating the response of honeybees to jujube flower disease based on changes in the intestinal microflora.

iTRAQ-based quantitative proteomic analysis identified Eno1 as a cadmium stress response gene in Propsilocerus akamusi (Tokunaga) hemolymph.

Propsilocerus akamusi (Tokunaga) is a common species of midge in Siberia, Japan, and China and an important prey species for fish and aquatic birds. Furthermore, this species has been shown to have an extraordinary capacity to resist cadmium (Cd) toxicity. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) coupled liquid chromatography tandem mass spectrometry (LC-MS/MS) was used to analyze relative changes in the P. akamusi hemolymph proteome following exposure to a sublethal concentration of Cd2+. The results showed that Cd2+ stress affects energy metabolism in P. akamusi. After examining the differentially expressed proteins (DEPs), only one up-regulated protein associated with metabolism, α-enolase (Eno1) was identified and further isolated and characterized. Sequence alignments showed that the deduced P. akamusi Eno1 amino acid sequence is highly conserved, with similarities of 77-95% noted when compared to other Dipteran Eno1 sequences. Furthermore, prolonged Cd2+ exposure impacted Eno1 transcription, protein expression and enzyme activity levels. These results suggest that Eno1 may play a role in the response to Cd2+ stress in P. akamusi.

Association between male infertility and either the +331G/A or the progins polymorphism of the progesterone receptor gene in a Chinese population.

BACKGROUND: Progesterone has been suggested to contribute to the regulation of spermatogenesis and to facilitate the production of viable sperm. Investigations have showed that polymorphism of progesterone receptor (PGR) is associated with some diseases. OBJECTIVE: To analyze the potential relationship between male infertility and the +331G/A and progins polymorphisms of PGR gene. MATERIALS AND METHODS: The cross-sectional study was carried out at the Department of Male Reproduction, Reproductive Medical Center, the Second Hospital of Jilin University. The restriction fragment length polymorphism (RFLP) technique was used to detect gene point mutations. Of the 145 semen samples analyzed, 35 were asthenozoospermic, 50 were oligoasthenozoospermic, 21 were azoospermic, 11 were teratozoospermic and 28 were from fertile male subjects. RESULTS: Statistical analyses revealed that the genotypes of the +331G/A polymorphisms were in Hardy-Weinberg equilibrium in both the fertile ((2)=0, p=0.534) and oligospermic groups ((2)=0.021, p=0.537). Similarly, the genotypes of the progins polymorphisms were also in Hardy-Weinberg equilibrium in both the fertile ((2)=0, p=1) and oligospermic groups ((2)=0.005, p=1). CONCLUSION: Our results indicated that polymorphisms of the +331G/A and progins of the PGR gene are unrelated to male infertility, at least in a Chinese population.