Effect and interaction of TNKS genetic polymorphisms and environmental factors on telomere damage in COEs-exposure workers.

Coke oven emissions (COEs) contain many carcinogenic polycyclic aromatic hydrocarbons (PAHs). Telomere damage is an early biological marker reflecting long-term COEs-exposure. Whereas, whether the genetic variations of telomere-regulated gene TNKS have an effect on the COEs-induced telomere damage is unknown. So we detected the environmental exposure levels, relative telomere length (RTL), and TNKS genetic polymorphisms among 544 COEs-exposure workers and 238 healthy participants. We found that the RTL of the wild homozygous GG genotype in rs1055328 locus was statistically shorter compared with the CG+CC genotype for the healthy participants using covariance analysis(P = 0.008). In the Generalized linear model (GLM) analysis, TNKS rs1055328 GG could accelerate telomere shortening (P = 0.011); and the interaction between TNKS rs1055328 GG and COEs-exposure had an effect on RTL (P = 0.002). In conclusion, this study was the first to discover the role of TNKS rs1055328 locus in COEs-induced telomere damage, and proved that chromosomal damage was a combined consequence of environmental and genetic factors.

Alternation of nasopharyngeal microbiota in healthy youth is associated with environmental factors: implication for respiratory diseases.

The nasopharynx is a key niche of the upper respiratory tract which contains many commensal bacteria and potential pathogens. Dysbiosis of the nasopharyngeal (NP) microbiota is associated with a variety of respiratory diseases. Little is known about NP flora in healthy youth, nor about its relationship with environmental factors. We characterized NP microbiota using the 16S rRNA gene sequencing method, and compared microbial composition from subjects sampled in Spring and Fall when exposed to different environmental factors. Results showed that beta diversity was significantly different. Phyla Acidobacteria, Gemmatimonadetes, and genus Symbiobacterium were positively associated with PM2.5. Genera Streptococcus, Prevotella, and [Prevotella] were positively correlated with temperature (T). Ozone (O3) was associated with these floras for exposure that occurred 30 days prior to collection. These preliminary data suggest that the change in environmental factors between spring and fall can influence the composition of the NP microbiota, characterized by a significant correlation to specific taxa. These changes in NP microbiota might be a potential risk factor for respiratory disease.

PM2.5 exposure induces reproductive injury through IRE1/JNK/autophagy signaling in male rats.

Fine particulate matter (PM2.5) constitutes the most significant air pollutant that causes health risks. However, the mechanism(s) underlying PM2.5-induced male reproductive injury has not been clarified. In the present study we explored whether PM2.5 activated the inositol-requiring enzyme 1 (IRE1)/c-Jun NH 2-terminal kinase (JNK)/autophagy-signaling pathway, and whether this pathway mediated reproductive injury in male rats. We established a male Sprague-Dawley rat model of PM2.5 (1.5 mg/kg) exposure-induced reproductive injury, and observed the intervention effects of STF083010 (an IRE1 inhibitor, 1 mg/kg). After 4 weeks of exposure, reproductive injury-related indicators and IRE1-cascade protein expression were analyzed. Our results showed that sperm quality and serum testosterone level significantly decreased and apoptotic index increased after exposure to PM2.5. After STF083010 intervention, sperm quality and serum testosterone level were significantly improved, while the apoptotic index was reduced. Under light microscopy, we observed that the structure of spermatogenic cells in the PM2.5 group was loose, and that the numbers of spermatogenic cells and mature spermatozoa were reduced. After STF083010 intervention, the structural damage to spermatogenic cells was improved, and the number of cells shed was reduced. Western blotting analysis showed that the expression of IRE1, phosphorylated JNK (p-JNK), beclin-1, and microtubule-associated protein 1 light chain 3(LC3)II/LC3I proteins was significantly upregulated, and that the expression of p62 protein was significantly downregulated in the PM2.5 group. The concomitant administration of STF083010 significantly antagonized the aforementioned adverse effects. STF083010 exerted specific protective effects on reproductive injury-related effects in male rats exposed to PM2.5, with effects mediated via IRE1/JNK/autophagy signaling.

Bacterial composition and community structure of the oropharynx of adults with asthma are associated with environmental factors.

The development and exacerbation of asthma are mainly attributed to inflammatory reactions caused by allergens. However, less is known about the development of asthma caused by microbial disorders in the oropharynx and induced by environmental factors. Here, the metagenome of the oropharyngeal microbiome of adults with asthma was analysed to identify their association with air pollutants. Oropharyngeal swabs from patients with asthma were collected in two winters (W1 and W2) with different environmental factor exposures. The bacterial composition and community structure of the oropharynx were analysed through high-throughput sequencing. After analysis, the α-diversity and ß-diversity exhibited significant differences between the two groups. LEfSe analysis detected 8 significantly different phyla and 11 significantly different genera between the W1 and W2 groups. Multiple linear regression analyses found that the asthma status might contribute to the alteration of microbial composition. Redundancy analysis showed that NO2 was the only environmental factor that significantly affected the microbial community structure of the oropharynx. The different genera associated with NO2 were Rothia, Actinomyces, Fusobacterium and Leptotrichia. The altered taxa related to PM2.5 were Cupriavidus and Acinetobacter. Actinobacillus and Prevotella showed a highly positive correlation with O3. Moreover, network analysis was carried out to explore the co-occurrence relationships of the main genera, and PICRUSt was conducted to predict bacterial functions. This study showed that environmental factors might cause alteration in the oropharyngeal flora, which might be a potential risk factor of asthma.

Heavy metal pollution and health risk assessment of agricultural soil near a smelter in an industrial city in China.

To assess heavy metal pollution and human health risk, a total of 28 topsoil samples were collected during four seasons from seven agricultural soil sites near a famous smelter in Jiyuan, China. The maximum concentrations of Cd, Pb, Hg, As, Zn, Cu, Ni, and Cr were 26.00, 2601.00, 3.29, 65.00, 410.00, 156.30, 54.80, and 73.60 mg kg-1, respectively. Compared with the sampling site nearest to the smelter, the concentrations of six metals at the farthest site were decreased significantly (P < 0.05). All sites were heavily contaminated, with Nemerow index (P) >3.0, and all sites had very high ecological risks related to Cd and Hg. The non-carcinogenic risk for children (based on combined exposure to the eight metals) was above the safety level. The carcinogenic risk of As for adults (8.98 × 10-6) and children (1.49 × 10-5) exceeded the acceptable level (1 × 10-6). Results suggest a serious health risk in the polluted areas, particularly for children.Abbreviation Cd: Cadmium; Pb: Lead; Hg: Mercury; As: Arsenic; Zn: Zinc; Cu: Copper; Ni: Nickel; Cr: Chromium; P: Nemerow index; RI: Potential ecological risk index; Ei: Monomial potential ecological risk of a specific heavy metal; HI: non-carcinogenic hazard index; CR: Carcinogenic risk; TN: Total nitrogen; TP: Total phosphorus; OM: Organic matter; MC: Moisture content; ADD: Average daily dose.

Association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed workers.

Omethoate, an organophosphorous pesticide, can cause a variety of health effects, especially the decrease of cholinesterase activity. The aim of this study is to explore the association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed population. Cholinesterase activities in whole blood, red blood cell and plasma were detected using acetylthiocholine and dithio-bis-(nitrobenzoic acid) method; Genetic Genotyping of POT1 rs1034794, POT1 rs10250202, TERF1 rs3863242 and TERT rs2736098 were performed with PCR-RFLP. The cholinesterase activities of whole blood, red blood cells and plasma in exposure group are significantly lower than that of the control group (P < 0.001). Multivariate analysis indicates that exposure group (b = - 1.016, P < 0.001), agender (b = 0.365, P < 0.001), drinking (b = 0.271, P = 0.004) and TERF1rs3863242 (b = - 0.368, P = 0.016) had an impact on cholinesterase activities. The results suggest that individual carrying AG+GG genotypes in TERF1 gene rs3863242 polymorphism were susceptible to damage in cholinesterase induced by omethoate.

Changes in the expression of genes involved in cell cycle regulation and the relative telomere length in the process of canceration induced by omethoate.

Organophosphorous pesticides (OPs), with high efficiency, broad-spectrum and low residue, are widely used in China. Omethoate is a broad category of organophosphorous pesticides and is more domestically utilized which has chronic toxic effect on human health caused by long-term, low-dose exposure to Ops, recently its potential genotoxicity has attracted wide attention which can cause chromosomal DNA damage. Thus, the aim of this study is screen susceptible biomarkers and explore the mechanism of canceration induced by omethoate. 180 long-term organophosphorus pesticide-exposed workers and 115 healthy controls were recruited. Quantitative polymerase chain reaction method was applied to determine the relative telomere length in peripheral lymphocyte DNA as well as p53 and p21 gene expression levels. Genetic polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism method. Multiple linear regression was conducted to explore the effects of exposure, expression levels, and polymorphisms in genes on the telomere length. The results showed the relative telomere lengths in the exposure group were significantly longer than that in the control group. The messenger RNA expression levels of p53 and p21 in exposure group were significantly lower than that in the control group; telomere lengths of the CA genotype individuals of p21 rs1801270 polymorphism locus were significantly longer than that of the CC genotype in the control group that were estimated using the Bonferroni method; and bivariate correlation analysis showed that the messenger RNA expression level of gene p53 was negatively correlated with telomere length, and the messenger RNA expression level of gene p21 was positively correlated with telomere length. Multivariate analysis found that p53 messenger RNA and p21 messenger RNA had an impact on telomere length. These results demonstrated that the messenger RNA expression levels of p53 and p21 may have a relationship with the changes in telomere length induced by omethoate and provided strong evidence for the mechanism of canceration induced by poison.

Do Environmental Fluoride Exposure and ESRα Genetic Variation Modulate Methylation Modification on Bone Changes in Chinese Farmers?

Although increasing evidence suggests that estrogen receptor α (ESRα) genetic variation could modify bone damage caused by environmental fluoride exposure, little is known about epigenetic mechanisms in relation to bone changes. A case-control study was conducted among farmers aged 18-55 years in Henan Province, China. X-ray was used to detect bone changes. Methylation status was determined by methylation-specific PCR. Genotypes were identified by Taqman probe and real-time PCR. In this study, we found that methylation status in the promoter region of the ESRα gene was lower in bone change cases than that in controls, which was only observed in male farmers after stratification by gender. Furthermore, methylation level was negatively associated with the urinary fluoride concentration in male farmers. No significant association was found between the distribution of ESRα rs2941740 genotypes and the risk of bone changes. Multivariate logistic regression analysis showed that after adjusting for age and gender, increased serum calcium and methylation status were protective factors for bone changes. No interaction effect was observed between fluoride exposure and ESRα rs2941740 polymorphism on bone changes. In conclusion, the current work suggests that bone changes are associated with methylation status, which might be modulated by fluoride exposure in male farmers. Methylation status and bone changes were not modified by ESRα gene rs2941740 polymorphism in the promoter region.

An Improved PCR-RFLP Assay for the Detection of a Polymorphism of PLIN1 Gene.

BACKGROUND: In recent research, it has been shown that there have been variants of rs894160 within the PLINI gene which have been associated with obesity, type 2 diabetes, and other diseases. But the isoschizomers such as the Mn1I enzyme required for the detection of this polymorphism are expensive. METHODS: The study used an improved PCR-RFLP method with mismatched base for detection of the single nucleotide polymorphism rs894160. RESULTS: After detecting 550 Chinese Han individuals, the genotype frequencies were 26.0% for AA, 50.0% for AG, and 24.0% for GG. The allelic frequencies were 51.0% for A and 49.0% for G. The PCR results were confirmed by DNA sequencing. The chi2 test showed the genotype and allele frequencies of PLIN1 do not deviate from Hardy-Weinberg equilibrium, and the sequences of amplified products were consistent with the one published in Genbank with the exception of mismatched base. CONCLUSIONS: Based on the PCR with mismatched primers we designed, the PLIN1 polymorphisms could be identified effectively.

Effect of oxidative stress on fluoride-induced apoptosis in primary cultured Sertoli cells of rats.

This study examined the effect of oxidative stress on the apoptosis of Sertoli cells induced by sodium fluoride (NaF). Cell viability, reactive oxygen species, malondialdehyde content, superoxide dismutase activity, mitochondrial membrane potential, and apoptosis were measured after the rat Sertoli cells were exposed to various concentrations of (0, 6, 12, and 24 µg/ml) sodium fluoride in the presence and absence of 2 mM N-acetylcysteine (NAC) for 24 h. The present study showed that decrease in cell viability and excessive oxidative stress were observed in NaF-treated cells. The treatment with NAC restored the decreased cell viability and excessive oxidative stress. Moreover, fluoride exposure decreased mitochondrial membrane potential and increased apoptosis in Sertoli cells. NAC was also found to suppress a loss of mitochondrial membrane potential and the percentage of apoptosis in NaF-treated Sertoli cells. This study proved that oxidative stress probably play a major role in NaF-induced apoptosis of Sertoli cells.

[Effects of resveratrol on Nrf2 signal pathway of chronic lead-exposed mouse brain tissue].

OBJECTIVE: To evaluate the effect of resveratrol on NF-E2-related factor 2 (Nrf2) signal pathway in the process of oxidative stress of mice brain tissue induced by chronic lead exposure. METHODS: A total of 48 healthy weaned C57BL/6 male mice were randomly divided into four groups (12 mice each group), control group, lead poisoning model group, lead poisoning coupled with resveratrol intervention group and resveratrol group. The lead poisoning mice model had been made by exposed to 0.2% lead acetate solution in the drinking water for 12 weeks. At the same time, the mice in the intervention group and resveratrol group were fed with resveratrol (50 mg/(kg · d)) by oral gavage and the other two groups were treated with the same volume of solvent, sodium carboxymethylcellulose. The serum and brain tissues were removed and used for detecting the lead concentration and measuring the activity of GSH-Px and the content of GSH and MDA. The levels of protein Nrf2 and γ-GCS were determined by western blot. RESULTS: Compared with the poisoning model group, GSH-Px activity and GSH content were significantly increased (P < 0.05), and MDA content was significantly decreased in the brain tissue intervened by resveratrol (P < 0.05). The protein expression of Nrf2 and γ-GCS were induced in the brain tissue of the intervention group (P < 0.05). CONCLUSION: Resveratrol could reduce the oxidation damage caused by chronic lead exposure in drinking water which may due to the protein activation of Nrf2, further up-regulated expression of targeting γ-GCS and adjusted dynamic balance of GSH system.

Sodium fluoride induces apoptosis through reactive oxygen species-mediated endoplasmic reticulum stress pathway in Sertoli cells.

Excessive fluoride exposure is known to contribute to reproductive system dysfunction, ultimately leading to pathological damage and apoptosis in cells. Although both oxidative and endoplasmic reticulum (ER) stresses have been implicated in fluorosis, the signaling pathways and their roles in sodium fluoride (NaF)-induced apoptosis of Sertoli cells have been sparsely described. In this study, oxidative damage, ER stress, and apoptosis were analyzed after Sertoli cells were treated with varying doses of NaF for 24hr. Moreover, the antioxidant N-acetylcysteine (NAC) and pro-apoptotic transcription factor CHOP knockdown were used to clarify the precise interplay between reactive oxygen species (ROS), ER stress and their roles in NaF-induced apoptosis in Sertoli cells. The present study indicated that NaF significantly decreased cell viability and induced apoptosis in Sertoli cells. In addition, NaF exposure facilitated the accumulation of ROS and increased nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) in Sertoli cells. Treatment with NAC caused remarkable recovery from these NaF-induced responses. Meanwhile, excessive NaF triggered ER stress as evidenced by up-regulated glucose-regulated protein 78 kDa (GRP78), PKR-like ER kinase (PERK), phosphorylation of eukaryotic translation initiation factor 2α (p-eIF2α) and CCAAT/enhancer-binding protein-homologous protein (CHOP), without affecting total eukaryotic translation initiation factor 2α (eIF2α). NAC effectively blocked the activation of ER stress, suggesting that NaF-induced ROS is an early event that triggers ER stress. Taken together, the results demonstrate that the ROS-mediated ER stress pathway is the crucial mechanistic event involved in NaF-induced apoptosis of Sertoli cells.

Estrogenic activity of organic extracts in the effluents treated byivity present treatment and the new process.

OBJECTIVE: Evaluate the estrogenic activity of organic extracts in the effluents treated by present treatment and the new technique find the scientific evidences of the new wastewater treatment technique to compare the removal efficiency of trace organic pollutants. METHODS: The solid phase extraction was adopted to enrich the trace organic pollutants in the water samples with resin adsorbing, then detected the estrogenic activity of them by using yeast estrogens screen and immature rat uterine bioassay. RESULTS: Yeast estrogens screen demonstrated that the organic extracts in the new technique effluent showed the activity as estrogen after concentrated 1000 times, because the activity of beta-galactosidase produced by yeast began to appear, otherwise, the same phenomenon occurred for the tertiary effluent, the secondary effluent and the influent at concentration of 500 times. At same concentration times of the extracts, the activity of beta-galactosidase of each group could be listed as, the new technique effluent < the tertiarity effluent < the secondary effluent < the influent. The immature rat uterine bioassay showed there was significant difference only between the high dose group of the influent organic extracts and the negative control (P < 0.05), but not between other groups, about the ratio of uterine weight to body weight. CONCLUSION: The estrogenic activity of urban sewage in Zhengzhou was significantly decreased after treated but it still possesses potential hazard to environment. And the trace organic pollutants in wastewater were removed by the new technique more efficiently than by the present treatment.

[The inherent toxicity of organic extracts in the effluents treated by present treatment and the new process].

OBJECTIVE: Evaluate the inherent toxicity of organic extracts in the effluents treated by present treatment and the new process find the scientific evidences of the new wastewater treatment technique to compare the removal efficiency of trace organic pollutants. METHODS: The Solid Phase Extraction was adopted to enrich the trace organic pollutants in the water samples with resin adsorbing, then detected the inherent toxicity of them by using Vicia faba root-tip micronucleus test and single cell gel electropheorsis test. RESULTS: After concentrated 100 times, the organic extracts enriched from the water samples showed some positive reactions. The micronuclear rates of root-tip cells were of significantly difference between all groups (F = 42.526, P < 0.001). Compared with each other, the group of DMSO and the group of new technique were not significantly different from the negative control (P > 0.05), but the group of secondary effluent and the group of influent were significantly different from the new technique (P < 0.05), at last, there was significant difference between the secondary effluent and the influent (P < 0.05). After exposed with DMSO and the organic extracts, the length of comet tails and the tailing ratio were obviously different between all groups (F = 243.535 and 148.623 correspodingly, P < 0.001). Compared with negative control, the length of comet tails and the tailing ratio of the influent group and the secondary effluent group were significantly different (P < 0.01). Compared with the influent group, the comet tail length of the secondary effluent group and the tertiary effluent group were both shorter (P < 0.01), and the tailing ratio were both smaller (P < 0.01). The tailing ratio of the tertiary effluent group was significantly smaller than the secondary effluent group. CONCLUSION: The inherent toxicity of urban sewage in Zhengzhou was significantly decreased after treated but it still possesses potential hazard to environment. And the trace organic pollutants in wastewater were removed by the new technique more efficiently than by the present treatment.

[Effects. of N-acetylcysteine on fluoride-induced endoplasmic reticulum stress in sertoli cells].

OBJECTIVE: Investigated the effects of N-acetylcysteine (NAC) on endoplasmic reticulum stress of sertoli cells induced by sodium fluoride (NaF). METHODS: Rat sertoli cells were exposed to various concentration of (0, 6, 12, 24 µg/ml) sodium fluoride with or without 2 mmol/L NAC for 24 hours. The cell viability was evaluated using trypan blue exclusion test. Intracellular reactive oxygen species (ROS) was measured using the fluorescent probe DCFH-DA. Western blot was used to test the expression of GRP78, PERK and CHOP. RESULTS: It was found that treatment with NAC (2 mmol/L) restored the reduced cell viability and excessive oxidative stress (P < 0.01). Moreover, fluoride exposure upregulated the expression of GRP7 8, PERK and CHOP protein (P <0. 01 ). NAC was also found to suppress the levels of GRP78, PERK and CHOP expression in NaF-treated cells (p<0.01). CONCLUSION: Endoplasmic reticulum stress signaling pathways were activated by ROS, and NAC attenuate endoplasmic reticulum stress through inhibiting the levels of ROS in NaF-treated sertoli cells.

[The influence of high fluoride exposure in drinking water on endocrine hormone in female].

OBJECTIVE: To explore the influence of water fluoride exposure on reproductive hormones in female. METHODS: Cross-sectional study was conducted in seven villages of a county in Henan province by using simple random sampling including high fluoride area, defluoridation project area and control area on April, 2011 based on the preliminary study results of fluoride concentration in drinking water. Women who were born and growth or lived in the village at least 5 years and aged 18-48 years old were recruited using cluster sampling. They were divided into high fluoride group (HFG, 116 subjects), defluoridation project group (DFPG, 132 subjects) and control group (CG, 227 subjects) in accordance with the above areas. All subjects accepted questionnaire and physical checkup. Fasting blood and morning urine samples were collected. The concentration of fluoride in urine was determined by fluoride ion selective electrode method. The serum level of GnRH was detected using enzyme linked immunosorbent assay (ELISA). The serum level of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), estradiol (E2) were determined by chemiluminesence immunoassay (CLIA). RESULTS: The average age was (39.44 ± 7.34), (38.84 ± 8.03), (37.45 ± 7.70) years old in female from DFPG, HFG and CG respectively, there were no significant differences among the three groups (F = 3.02, P = 0.05). The urine fluoride levels were (1.34 ± 1.07), (2.59 ± 1.57), (0.92 ± 0.46) mg/ml in female from DFPG, HFG and CG respectively, there was a significant difference among three groups (F = 105.38, P < 0.01). No significant differences were observed of serum GnRH, LH, T, FSH and E2 among three groups in follicular phase (P > 0.05). The serum levels of E2 in Ovulatory period were 67.73, 58.09, 84.96 pg/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in CG (H = 4.00, P < 0.05). The serum levels of T in Ovulatory period were 0.55, 0.45, 0.55 ng/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in DFPG (H = 6.47, P < 0.05), but no significant difference was observed between HFG and CG (H = 2.41, P > 0.05). The serum levels of GnRH in Luteal phase were 24.09, 20.16, 23.50 ng/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in DFPG (H = 14.14, P < 0.05) and CG (H = 12.53, P < 0.05). The serum level of E2 in luteal phase were 81.47, 64.60, 74.55 pg/ml in female from DFPG, HFG and CG respectively. It was lower in HFG than that in DFPG (H = 5.69, P < 0.05). As for LH, FSH and T, no significant differences were observed among the three groups (P > 0.05 respectively). The abnormal rates of E2 level were 22.73 (30/102), 37.93 (44/72), 20.26 (46/181) in female from DFPG, HFG and CG respectively. The E2 abnormal rate in female from HFG was higher that from DFPG (χ(2) = 6.82, P < 0.05) and CG (χ(2) = 12.38, P < 0.05). CONCLUSION: Fluoride exposure may influence reproductive hormones in female, especially in ovulatory and luteal phase of menstrual cycle.

[Effects of fluoride on oxidative stress and apoptosis in primary culture of rat sertoli cells].

OBJECTIVE: To study effects of fluoride on oxidative stress and apoptosis in rat sertoli cells. METHODS: Intracellular reactive oxygen species (ROS) , malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, mitochondrial membrane potential and percentage of apoptosis were measured after the rat sertoli cells were incubated with 0, 6, 12 and 24 microg/ml sodium fluorides or 24 hours in vitro. RESULTS: Fluoride decreased the cell activity significantly (P < 0.01). The results suggested that exposure to fluoride significantly increased the level of ROS and MDA content (P < 0.01), fluoride also decreased SOD activity significantly (P < 0.05 or P < 0.01). In addition, with the NaF dose increased, there is a significantly decreasing in mitochondrial membrane potential and a significantly increasing in early apoptosis rate (P < 0.01). CONCLUSION: Fluoride can induce excessive oxidative stress and increased apoptosis rate in rat sertoli cells.

[Influence of phthalates from Shaying river on children's intelligence and secretion of thyroid hormone].

OBJECTIVE: To investigate the effect of phthalates exposure from drinking water on children's intelligence and secretion of thyroid hormone. METHODS: Two villages in S County were selected randomly as polluted area and control area according to the distance from the Shaying river basin. Phthalates including DEP, DBP, DMP, DEHP were measured both in the river water and drinking water using HPLC method. Children aged 8 to 13 years old studying in the village primary school were recruited by cluster sampling (n = 154). The combined Reven Test was used to test children intelligence and ELISA method was used to determined thyroid hormone levels. RESULTS: The concentrations of phthalates (DEP, DBP) were exceeding standards of surface water quality in any of the three sections of the river. Compared to the control area, the concentration of DEP and DBP in drinking water were significant higher in the polluted area than that in control area (P < 0.05). Children from polluted area had significant higher FT4 concentration compared to children from control area (P < 0.05). Intelligence level in children from polluted area was lower than that from control area (P < 0.05). CONCLUSION: The drinking water has been polluted by Shaying river and thyroid hormones levels of children were affected in the polluted areas. It is necessary to verify if this change is related to the phthalates.

[Influence of water fluoride exposure on sex hormone binding globulin and testosterone in adult male].

OBJECTIVE: To explore the influence of water fluoride exposure on sex hormone binding globulin (SHBG) and testosterone in adult male. METHODS: Cross-sectional study was conducted in three villages of Tongxu county including high fluoride group (HFG), defluoridation project group (DFPG) and control group (CG) based on the fluoride concentration in drinking water. Adult male who were born and raised in the village and aged 18 - 50 years old were recruited using cluster sampling. Fasting blood and morning urine samples were collected. The fluoride levels in drinking water and urine were detected by fluoride-ion selective electrode method. Serum SHBG level was determined using enzyme-linked immunosorbent assay (ELISA). The chemical luminescence immune analysis method was used to detect serum testosterone content. RESULTS: Serum SHBG level was 47.85 nmol/L in CG, 31.37 nmol/L in DFPG and 24.52 nmol/L in HFG respectively. There were significant difference among of three groups (P < 0.05). Serum testosterone level was 3.69 ng/ml in CG, 4.61 ng/ml in DFPG and 4.83 ng/ml in HFG respectively. Serum testosterone level in HFG was significantly higher than that in CG (P < 0.05). Serum SHBG level in HFG has positive correlation with serum testosterone (r = 0.230, P = 0.049), which has not been observed in DFPG and CG. CONCLUSIONS: Long-time fluorine exposure may affect serum SHBG and testosterone level in adult male.

[Effect of fluoride on the expression of StAR mRNA and P450scc mRNA in the progesterone synthesis of mouse Leydig tumor cells].

OBJECTIVE: To observe the effect of sodium fluoride on the expression of steroidogenic acute regulatory protein (StAR) mRNA and cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) mRNA in the testosterone synthesis of mouse Leydig tumor cells (mLTC-1). and to explore the molecular mechanisms of fluoride on reproductive injury. METHODS: Using mLTC-1 cells as a model, progesterone in the supernatant of cell culture medium was measured by RIA. The expression of StAR mRNA and P450scc mRNA in mLTC-1 cells was determined by real-time PCR. RESULTS: In comparison with the control group, the expression of StAR mRNA and P450scc mRNA in mLTC-1 cells and the secretion of progesterone of mLTC-1 cells in the three fluoride groups with 12,16 and 20 microg/ml of NaF in their media respectively were obviously lower (P < 0.05). CONCLUSION: The expression of StAR mRNA and P450scc mRNA in mLTC-1 cells could be inhibited by NaF, and consequently the secretion of progesterone in mLTC-1 cells was affected.