Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section)

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

[Association of 8-hydroxyguanine glycosidase OGG1 Ser326Cys polymorphism with male infertility]

OBJECTIVE

To explore the association of 8-hydroxyguanine glycosidase OGG1 Ser326Cys polymorphism with semen quality and the risk of male infertility.

METHODS

This case-control study included 620 idiopathic infertile patients and 385 normal fertile controls. We determined their genotypes by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and analyzed their semen quality by computer-aided semen analysis (CASA).

RESULTS

The individuals with OGG1 326 Cys/Cys showed significantly lower sperm motility and concentration ([52.1 +/- 26.7]% and (3.75 +/- 0.91) x 10(6)/ml, ln transformed value) than the Ser/Ser carriers ([59.0 +/- 21.8] % and (4.12 +/- 0.88) x 10(6)/ml, ln transformed value) (P < 0.05). The risk of male infertility increased 69% in the OGG1 326Cys allele carriers as compared with the Ser carriers (OR = 1.69, 95% CI: 1.24 -2.31).

CONCLUSION

OGG1 326 Ser/Cys polymorphism might contribute to the risk of male infertility in the southern Chinese population.

[Bulky DNA adducts in human sperm correlate with semen parameters and sperm apoptosis]

OBJECTIVE

To explore the correlation of sperm polycyclic aromatic hydrocarbons (PAH)-DNA adducts with semen quality and sperm apoptosis.

METHODS

We collected semen samples from 433 infertile Chinese men, detected sperm PAH-DNA adducts using immunofluorescence staining and flow cytometry, and determined the rate of sperm apoptosis by TUNEL.

RESULTS

Multiple linear regression analysis showed that the level of sperm PAH-DNA adducts was correlated negatively with sperm concentration (beta = -0.632), total sperm count (beta = -0.830) and sperm motility (beta = -9.647), but positively with the rate of sperm apoptosis (beta = 0.130).

CONCLUSION

Sperm PAH-DNA adducts are evidently correlated with semen quality and sperm apoptosis, and play an important role in the evaluation of male productivity.

Dose-dependent pharmacokinetics of bulleyaconitine A in rats

This study was conducted to determine the pharmacokinetic characteristics of bulleyaconitine A (BLA) after oral gavage and intravenous administration of BLA at a single dose of 0.04, 0.12, 0.36 mg/kg (oral) or 0.02 mg/kg (i.v.) in male Sprague-Dawley rats. Plasma concentration profiles were analysed using a non-compartmental pharmacokinetic method. Following i.v. 0.02 mg/kg and oral administration 0.04, 0.12 or 0.36 mg/kg, the geometric mean Cmax values were 19.97, 2.11, 5.11 and 11.47 ng/ml, respectively; the corresponding geometric mean AUC(0-t) values were 10.50, 3.19, 9.59 and 18.10 ng x h/ml, respectively. The median Tmax values were 0.033, 0.167, 0.167 and 0.167 h, respectively. The terminal elimination half-lives (t1/2) were 1.23, 2.48, 1.93 and 2.17h, respectively. The results showed that Cmax and AUC(0-t) increased with increasing doses of BLA. The increase in exposure with increasing dose was lower than expected under conditions of strict proportionality.

Genetic variants in TP53 and MDM2 associated with male infertility in Chinese population

The TP53, a transcriptional regulator and tumor suppressor, is functionally important in spermatogenesis. MDM2 is a key regulator of the p53 pathway and modulates p53 activity. Both proteins have been functionally linked to germ cell apoptosis, which may affect human infertility, but very little is known on how common polymorphisms in these genes may influence germ cell apoptosis and the risk of male infertility. Thus, this study was designed to test whether three previously described polymorphisms 72Arg>Pro (rs1042522) and the Ex2+19C>T (rs2287498) in TP53, and the 5' untranslated region (5' UTR) 309T>G (rs937283) in MDM2, are associated with idiopathic male infertility in a Chinese population. The three polymorphisms were genotyped using OpenArray assay in a hospital-based case-control study, including 580 infertile patients and 580 fertile controls. Our analyses revealed that TP53 Ex2+19C>T and MDM2 309T>G polymorphisms are associated with male infertility. Furthermore, we detected a nearly statistically significant additive interaction between TP53 rs2287498 and MDM2 rs937283 for the development of male infertility (P(interaction)=0.055). In summary, this study found preliminary evidence, demonstrating that genetic variants in genes of the TP53 pathway are risk factors for male infertility.