Immobilisation remediation of arsenic-contaminated soils with promising CaAl-layered double hydroxide and bioavailability, bioaccessibility, and speciation-based health risk assessment.

Arsenic (As)-contaminated soil poses great health risk to human mostly through inadvertent oral exposure. We investigated CaAl-layered double hydroxide (CaAl-LDH), a promising immobilising agent, for the remediation of As-contaminated Chinese soils. The effects on specific soil properties and As fractionation were analyzed, and changes in the health risk of soil As were accurately assessed by means of advanced in vivo mice model and in vitro PBET-SHIME model. Results showed that the application of CaAl-LDH significantly increased soil pH and concentration of Fe and Al oxides, and effectively converted active As fractions into the most stable residual fraction, guaranteeing long-term remediation stability. Based on in vivo test, As relative bioavailability was significantly reduced by 37.75%. Based on in vitro test, As bioaccessibility in small intestinal and colon phases was significantly reduced by 25.65% and 28.57%, respectively. Furthermore, As metabolism (reduction and methylation) by the gut microbiota inhabiting colon was clearly observed. After immobilisation with CaAl-LDH, the concentration of bioaccessible As(Ⅴ) in the colon fluid was significantly reduced by 61.91%, and organic As (least toxic MMA(V) and DMA(V)) became the main species, which further reduced the health risk of soil As. In summary, CaAl-LDH proved to be a feasible option for immobilisation remediation of As-contaminated soils, and considerable progress was made in relevant health risk assessment.

[Effects of mifepristone of different doses on emergency contraception, a randomized double-blind study].

OBJECTIVE: To compare the effects of mifepristone of different doses on emergency contraception. METHODS: 3,052 healthy women with regular menstrual cycle who visited the 10 family planning institutes and hospitals in Beijing, Shanghai, Shangdong, Sichuan, Tianjin, Guangdong, and Liaoning for emergency contraception within the period of 120 hours after a single act of unprotected sex were given a single dose of 10 mg or 25 mg mifepristone randomly and double-blindly. They were asked to record the vaginal hemorrhage that would occur and not to have unprotected sex until the next menstrual onset when they were followed up. The trial for a specific subject ended when she menstruated. If the menstruation was irregular or a specific subject failed to menstruate on time a blood or urine human chorionic gonadotropin (hCG) test was made. If the hCG test was negative, an appointment was made to follow up once one week later. If the hCG test was positive ultrasound examination was made to detect pregnancy. If the subject still failed to menstruate and the hCG test was still negative follow-up for this subject could be finished. RESULTS: Twenty-two of the 3,052 subjects were lost to follow up. Among the remaining 3,030 women 1,516 were in the 10 mg group and 1 514 in the 25 mg group. Seventeen pregnancies occurred in each group, with a pregnancy rate of 1.1% for both groups. The relative risk of pregnancy of treatment of 25 mg mifepristone in comparison with treatment of 10 mg mifepristone was 1.0 (95% CI: 0.51-1.95). Both doses prevented about 85% approximately 86% of the anticipated pregnancy if no measure had been adopted. The pregnancy rate nearly doubled in the women who had unprotected sex after treatment of mifepristone. The efficacy of mifepristone decreased along with the delay of mifepristone administration. Side effects were uncommon and mild. Delay of 7 days or more in the onset of next menstruation occurred in 9%-10% of the women. CONCLUSION: Mifepristone of the dose of 10 mg is safe and effective for emergency contraception. Earlier administration is preferable, although the method can be used effectively up to five days after the unprotected sex.

A multicenter contraceptive efficacy study of injectable testosterone undecanoate in healthy Chinese men.

This report describes a Phase II, multicenter, contraceptive efficacy clinical trial using monthly injections of testosterone undecanoate (TU) alone at a dose of 500 mg in healthy Chinese men. Three hundred eight healthy men were recruited in six centers distributed throughout China. Volunteers underwent a control period with no treatment, then a 12-month treatment period including a 6-month suppression phase followed by a 6-month efficacy phase and a 12-month recovery period. During the suppression phase, an initial loading dose of 1000 mg TU, followed by 500 TU at monthly intervals were given until azoospermia or severe oligozoospermia was achieved, up to a maximum of six injections. During the efficacy phase, 500 mg TU were administered at monthly intervals for 6 months. Nine of 308 men did not achieve azoospermia or severe oligozoospermia (<3 x 10(6)/ml) within the 6-month suppression phase. This gave a methodological failure rate of 2.9/100 couple years (95% confidence interval of 1.0-4.8/100 couple years). Two hundred ninety-six men entered the efficacy phase. The continuation rate during the efficacy phase was 95/100 couple years. There were no pregnancies caused by men who achieved azoospermia or severe oligozoospermia. Reappearance of sperm occurred in six men during the efficacy phase, and one pregnancy was attributed to sperm rebound. This gave a secondary failure rate of 2.3/100 couple years (95% confidence interval of 0.5-4.2/100 couple years). Thus, the total failure rate was 5.2%, and total efficacy was 94.8%. Spermatogenesis in all subjects returned to the normal reference range within the recovery period. The mean serum testosterone concentration increased 131%, and the mean serum LH and FSH concentrations decreased 72% and 70%, respectively, after TU injections during the treatment period. The mean level of serum high density lipoprotein cholesterol decreased (14%), and the mean hematocrit increased 6% compared with baseline. No serious adverse events and no significant changes in serum chemistry occurred during the study. The results showed that monthly TU injection at a dose of 500 mg after an initial loading dose of 1000 mg can effectively, safely, and reversibly suppress spermatogenesis in healthy Chinese men without serious adverse effects.