First-trimester screening for Down syndrome; the role of nasal bone assessment in the Korean population

Objectives The aim of this study was to evaluate the role of nasal bone assessment in first-trimester screening for Down syndrome (DS) in the Korean population. Methods From July 2004 to March 2006, we prospectively evaluated the fetal nasal bones at 11–14 weeks' gestation in the Korean population. Results A successful evaluation was possible in 6490 of 6787 fetuses (95.6%). Absent, hypoechoic, and short nasal bones were seen in 4 (26.7%), 4 (26.7%), and 1 (6.7%) of 15 fetuses with DS, respectively, whereas in 5 (0.1%), 11 (0.2%), and 246 (3.8%) of 6456 normal fetuses. The incidence of absent and hypoechoic nasal bone showed significant differences between normal fetuses and fetuses with DS (P < 0.0005, both). Screening for DS using an absent or hypoechoic nasal bone resulted in a sensitivity of 53.3%, a specificity of 99.8%, a positive likelihood ratio of 215.2, and a negative likelihood ratio of 0.5. Conclusion Our study showed that nasal bone abnormality at 11–14 weeks of gestation had a high association with DS in the Korean population. This suggests that nasal bone assessment can be used to supplement the current first-trimester screening for DS in the Korean population. Copyright © 2007 John Wiley & Sons, Ltd.     

阳离子型微乳液一亚硫酸钠光度法测定α-TNT

以阳离子型微乳液ＣＰＣ／正戊醇／正已烷／水为介质，进行了α－ＴＮＴ－Ｎａ２ＳＯ３分光光度法的研究（ε＝３．０６５×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）与以ＣＰＣ为介质（ε＝２．６４４×１０４Ｌ·ｍｏｌ－１·ｃｍ－１）比较，测定灵敏度明显提高，α－ＴＮＴ在０．０５～２０μｇ／ｍＬ范围内符合比耳定律．相对标准偏差０．１９７％．该法成功地应用于污染土壤中及合成水样中α－ＴＮＴ的测定．     

Genetic amniocentesis in multiple gestations

Thirty-one genetic amniocenteses involving multiple gestations were performed in the genetics unit between 1976 and 1982. Three sets of triplets were included. Precise locations of the sacs were determined using real-time ultrasonography and successful sampling of all sacs was accomplished. Spontaneous abortions occurred in two normal twins and one normal triplet gestation. Two therapeutic abortions were performed for fetal abnormalities. Two cases of discordance for trisomy 21 (one twin and one triplet) were allowed to continue; the twin case terminated at 25 weeks' gestation with neonatal deaths and the triplets are alive and well.     

含铬固体废渣中Cr~(3+) 的氧化

研究了ｐＨ、温度对铬渣中Ｃｒ３＋的氧化速率的影响．结果表明，在碱性条件下，空气中的氧气具有相当强的氧化性，足以将Ｃｒ３＋氧化为Ｃｒ６＋，且随ｐＨ、温度的升高而加快．     

Cr6+的隆线溞趋光指数与LC50急性毒性的比较

采用隆线 (D .carinata)为试验生物 ,研究Cr6 对隆线趋光指数的影响 ,并与LC50 急性毒性结果进行了比较 .结果表明 ,水的趋光指数 (Ip)与铬浓度存在着显著的相关关系 (y =0 391- 0 5 14x ,R2 =0 81) ,3h的Ip 监测下限为 0 0 5 6mg·L-1,分别是LC50 ( 2 4h)及LC50 ( 48h)的 2 3 6 0 %和 39 0 0 % ,仅相当于LC50 ( 96h) .因此 ,利用水趋光指数 ,可能为评价水体的健康状况提供一种快速、灵敏的方法     

Abnormal immunological development in fetuses with trisomy 18

Flow cytometry was used to enumerate the lymphocyte subpopulations in fetal blood obtained by cordocentesis from eight trisomy 18 fetuses at 20–36 weeks' gestation. Compared with values in chromosomally normal fetuses, in trisomy 18 the mean T- and natural killer (NK) cell counts were significantly lower (t= − 7·63, P<0·001 and t= − 3·58, P<0·01, respectively); the mean B-cell count was not significantly different (t= − 1·32). These findings demonstrate that in trisomy 18 there is abnormal intrauterine development of the immune system.     

First-trimester screening for fetal chromosomal abnormalities. Preliminary results

We have started a multicentre trial to study the possibilities of first-trimester maternal serum screening for fetal chromosomal abnormalities. Maternal blood samples were obtained before 13 weeks of gestation. We present the preliminary results of the first 950 patients on alpha-fetoprotein (AFP). Results on cancer antigen 125 (CA 125) in Down's syndrome and normal pregnancies are also presented. We conclude that the results on AFP are promising and that CA 125 might be predictive for fetal Down's syndrome.     

凝胶化改性尼龙-6渔网的防生物附着性能研究

采用对渔网尼龙-6纤维进行接枝丙烯酸的方法,制备防止海洋污损生物附着的表面凝胶化改性渔网材料.以小球藻、杜氏藻、金藻为实验海藻,研究了三种海藻在改性材料表面的生物附着性能.结果表明,三种海藻在聚丙烯酸凝胶改性尼龙-6纤维表面的附着量明显少于普通尼龙-6纤维.改性纤维的接枝率越高,海藻的附着量越小,接枝率16.1%以上时纤维具有优良抗生物附着性能.