Ecological risks assessment and pollution source identification of trace elements in contaminated sediments from the Pearl River Delta, China.

Sediments from 14 stations in the Foshan Waterway, a river crossing the industrial district of Guangdong Province, South China, were sampled and subsequently analyzed. The 14 stations were selected for the pollution discharging features of the river, such as the hydrology, the distribution of pollution sources, and the locations of wastewater outlets. The ecological risks were assessed, and the pollution sources were identified to provide valuable information for environmental impact assessment and pollution control. The spatial variability was high and the range were (in milligrams per kilogram dry weight): Pb, 46.0~382.8; Cu, 33.7~ 482.3; Zn, 62.2~1,568.7; Ni, 28.5~130.7; Cr, 34.7~1,656.1; Cd, 0.50~8.53; Hg, 0.02~8.27; and As, 5.77~66.09. The evaluation results of enrichment factor and potential ecological risk index indicate that the metal pollution in the surface and bottom sediments were severely polluted and could pose serious threat to the ecosystem in most stations. Although the hazard levels of the trace element differed among the stations, Hg was the most serious pollutant in all stations. The results of principal component analysis (PCA) show that the discharge of industrial wastewater is the most important polluting factor whereas domestic sewage, which contains a large amount of organic substances, accelerates metal deposition. And potential pollution sources were identified by the way of integrating the analysis results of PCA and data gained from the local government. Therefore, the conclusion is drawn that Foshan Waterway is seriously polluted with trace elements, both in the surface sediment (0 to 20 cm) and the bottom sediments (21 to 50 cm) are contaminated.

[Development and genetic polymorphism of abnormal pronuclear zygotes after intracytoplasmic sperm injection].

OBJECTIVE: To compare the development of abnormal pronuclear zygotes after intracytoplasmic sperm injection (ICSI) and analyze their genetic polymorphism. METHODS: Four hundred and ninety three abnormal pronuclear zygotes after ICSI were divided into three groups based on the number of pronuclei: 347 nonpronuclear oocytes, 71 monopronuclear zygotes and 75 multipronuclear zygotes. All of them were cultured in the medium of Vitrolife G5 series(TM). Sixteen short tandem repeats (STR) of seven blastocysts were then analyzed by ABI3100. RESULTS: The cleavage rate of nonpronuclear group (25.4%) was lower than that of the others (P<0.01), the proportion of blocked embryos in nonpronuclear group (48.9%) was significantly higher than that of the others (P<0.05), but the blastocyst rate showed no significant difference in three groups (P>0.05). The genetic polymorphism of the 16 STRs showed that the blastocysts from the nonpronuclear and multipronuclear were diploid, and one of the blastocysts from nonpronuclear oocyte was Y-bearing. CONCLUSION: The zygotes with abnormal pronuclei after ICSI might have development potential, and the blastocysts from nonpronuclear oocytes and multipronuclear zygotes could be diploid.

Monozygotic quadruplets after in vitro fertilization and embryo transfer.

A unique case is reported of a quadruple gestation (monochorionic quadramniotic quadruplets) after in vitro fertilization (IVF) and the transfer of two embryos. On the ninth week of pregnancy, a transvaginal sonogram revealed that there was no heart beat in any of the fetuses. Uterine curettage was then performed. The fetal karyotype was 46, XX, inv (9) (p11q13).

[In vitro maturation of human oocytes from pregnant late term: a new source of oocytes].

OBJECTIVE: To investigate the in vitro maturation of human oocytes (IVM) from pregnant late term, natural cycles and Gn stimulating cycles and the effect of granulose cells on IVM from pregnant late term. METHODS: A total of 1086 immature oocytes were obtained including 633 oocyte-cumulus complexes (OCCs) and 453 denuded oocytes (DOs). OCCs were divided into pregnant late term group, natural cycle group and IVM group, and DOs were divided into pregnant late term group, natural cycle group and controlled ovarian hyperstimulation (COH) group. All the oocytes were matured in IVM culture system and fertilized by ICSI. The embryos were cultured to blastocyst stage except that those in IVM group were transferred into the uterus. The main outcomes were assessed including maturation rate (MR), fertilization rate (FR), cleavage rate (CR), and blastulation rate (BR) (natural cycle group, pregnant late term group and COH group) and pregnancy rate per transfer cycle (PR) of IVM group. RESULTS: MR of OCCs in pregnant late term group, natural cycle group and COH group was 74.3%, 76.9% and 82.2%, respectively, showing statistical difference between pregnant late term cycle group and IVM group. No statistical difference was observed in FR, CR or BR between the three groups. For IVM cycle group, clinical pregnancy rate of 20% per aspiration was achieved. For DOs, MR of COH group (86.0%) was significantly higher than that of the natural cycle group (72.5%) and pregnant late term group (72.7%) (P<0.01). FR, CR and BR showed no statistical difference among the 3 groups. No difference was found in MR, FR, CR and BR between OCCs group and DOs group from pregnant late term. CONCLUSIONS: The oocytes from pregnant late term have the same development potential as those from natural cycles or Gn stimulating cycles in vitro, and provide a new source of donor oocytes. Granulose cells do not affect the IVM from pregnant late term.

[Sperm acrosin activity helps predict IVF-ET outcome].

OBJECTIVE: To investigate the effect of sperm acrosin activity on the IVF-ET outcome. METHODS: We analyzed sperm parameters, morphology and acrosin activity for 909 infertile husbands by computer-assisted self-assessment (CASA), modified Papanicolaou staining and N-alpha-benzoyl-DL-arginine-p-nitroanilide (BAPNA), respectively, and detected the rates of fertilization, cleavage, quality embryos, embryo cryopreservation, implantation, clinical pregnancy and abortion. The wives were identified as normal or with mere oviduct problems. RESULTS: The rate of normal sperm morphology and sperm motility, vitality, rapid progressive velocity and concentration were significantly lower in the abnormal acrosin activity group than in the normal one (P < 0.01). Significant positive correlations were observed between acrosin activity and the above-mentioned semen parameters (P < 0.01). There were no significant differences in the number of retrieved eggs, the rates of cleavage, quality embryos, embryo cryopreservation, non-embryo transfer cycles and miscarriages, and the number of transferred embryos between the two groups (P > 0.05). The fertilization rate, the percentage of transfer cycles with only 1 embryo and the rate of implantation and clinical pregnancy were notably higher in the normal acrosin activity group than in the abnormal one (P < 0.01). CONCLUSION: Sperm acrosin activity is closely related with semen parameters, and it helps to predict the sperm fertilizing capacity and IVF-ET outcome.