Risk assessment of xenoestrogens in a typical domestic sewage-holding lake in China

Release of domestic sewage leads to accumulation of xenoestrogens in holding waters, especially in closed or semi-enclosed waters such as lakes. In the study, the occurrence, distribution, estrogenic activity and risk of eight xenoestreogens were evaluated in Lake Donghu, China. Nonylphenol (NP), octylphenol (OP), and bisphenol A (BPA) were identified as the main xenoestrogens ranging from tens of ng L⁻¹ (in the surface water) or ng g⁻¹ dw (in the suspended particles and sediment) to tens of μg L⁻¹ or μg g⁻¹ dw. The sum of 17β-estradiol equivalents (∑EEQs) ranged from 0.32 to 45.02 ng L⁻¹ in the surface water, 0.53 to 71.86 ng g⁻¹ dw in the suspended particles, and 0.09 to 24.73 ng g⁻¹ dw in the sediment. Diethylstilbestrol (DES) was determined as the main contributor to ∑EEQs followed by NP. The risk assessment showed a higher risk in the surface water than in the suspended particles and sediment in such domestic sewage-holding lake.     

Second-trimester maternal serum screening using alpha-fetoprotein,human chorionic gonadotrophin,and unconjugated oestriol: Experience of a regional programme

Over a 2-year period from January 1991 to December 1992, second-trimester maternal serum screening for Down's syndrome using alpha-fetoprotein (aFP), human chorionic gonadotrophin (hCG), and unconjugated oestriol (uE₃) was made available to five health districts in East Anglia, with a total population of 1·2 million. Amniocentesis was offered when the risk of Down's syndrome at term was 1:200 or greater. 25359 singleton pregnancies were screened, representing an uptake of 77 per cent. The recall rate for the 24 per cent of women who had not had a dating scan prior to the test was 9·4 per cent compared with 3·9 per cent for those who had been scanned (P<0·0005). Seventy-five per cent (36/48) of Down's syndrome pregnancies were detected for a false-positive rate of 4·0 per cent. Twenty-five out of 36 of detected Down's syndrome pregnancies were dated by scan prior to sampling, and in the 11 remaining cases, the dates were confirmed by scan after a high-risk result was obtained. The exclusion of uE₃ from the screening protocol would have reduced the detection rate to 52 per cent (25/48) for the same false-positive rate. Eighty-five per cent of women identified at high risk accepted the offer of an amniocentesis. Other fetal abnormalities detected were trisomy 18 (3), trisomy 13 (2), 45,X (6), 69,XXX (5), other chromosome abnormalities (9), open neural tube defects (26), hydrocephalus (7), abdominal wall defects (4), and steroid sulphatase deficiency (6).     

Low or absent unconjugated estriol in pregnancy: an indicator for steroid sulfatase deficiency detectable by fluorescence in situ hybridization and biochemical analysis

It has been previously reported that a low or absent maternal serum unconjugated estriol (uE3) level is associated with placental steroid sulfatase (STS) deficiency. Here we report a correlation between patients who present with a very low or absent maternal serum uE3 and a deletion of the STS gene as assessed by fluorescence in situ hybridization (FISH). We studied nine prenatal cases that presented to the clinical laboratory with an abnormal triple screen, specifically low or absent maternal serum uE3 and a 46,XY karyotype. FISH analysis showed complete deletion of a probe containing the STS gene in six cases and one case had a partial deletion (reduced but not absent signal). The remaining two cases were not deleted for the STS probe. All mothers tested whose fetus showed a deletion were shown to be STS deletion carriers using FISH. Biochemical analysis was performed on 7/9 prenatal specimens. All fetuses deleted for the STS probe were also found to be deficient for STS by biochemical analysis of cultured amniotic fluid (5/5). Of the two fetuses not deleted for the STS probe, one was deficient for STS activity, while the other had a normal result. The abnormal result of enzyme deficiency by biochemical analysis in a non-deletion case likely represents a mutation in the STS gene, not detectable by this FISH assay. Postnatal FISH confirmation of the STS deletion was performed in 1/7 cases. Clinical follow-up was available for 4/9 cases following birth. Copyright © 2002 John Wiley & Sons, Ltd.     

Four-marker serum screening for Down's syndrome

The value of measuring the separate sub-units of human chorionic gonadotrophin (free α-hCG and free β-hCG) instead of total hCG together with alpha-fetoprotein (AFP) and unconjugated oestriol (uE₃) was examined to determine the effect on the performance of serum screening for Down's syndrome between 15 and 22 weeks of pregnancy. The study was based on stored serum samples relating to 75 singleton pregnancies with fetal Down's syndrome and 367 unaffected singleton pregnancies, matched for maternal age, gestational age, and duration of storage of the serum sample, supplemented by data from 970 white women with unaffected pregnancies. Using the four serum markers AFP, uE₃, free β-hCG, and free α-hCG, in addition to maternal age, 65 per cent of Down's syndrome pregnancies were detected for a 5 per cent false-positive rate compared with 59 per cent with the conventional triple test (AFP, uE₃, total hCG with maternal age). If gestation was based on an ultrasound scan examination, the detection rate was 72 per cent using the four serum markers compared with 67 per cent with the triple test. As an alternative illustration, if the detection rate was kept at 60 per cent and gestation was estimated by an ultrasound scan examination the four-marker test reduced the false-positive rate by one-third from 3 per cent using the triple test to 2 per cent with the four-marker test. Screening performance was hardly affected by adjusting marker levels for maternal weight. The four-marker test is, both from a medical and from a financial perspective, the most effective method of prenatal screening for Down's syndrome suitable for routine use.     

水体类固醇雌激素污染现状研究进展

类固醇雌激素被认为具有极强的内分泌干扰性和生物活性,在极低浓度下就能引起人体或动物生殖障碍、行为异常和幼体变异等.由于水体中的类固醇雌激素的生态环境效应最为直接,因此,本文综述了近年来关于水环境中几种常见的类固醇雌激素的基本特征、污染现状、来源及迁移过程的研究,以期为类固醇雌激素的水处理技术研究提供基础信息.