Prenatal morphology in meckel's syndrome (with special reference to polycystic kidneys and double encephalocele)

Prenatal morphology of Meckel's syndrome was studied in five fetuses of different gestational age, that had been aborted because ultrasonography and elevated amniotic AFP-levels indicated neural tube defect. Histologically, the enlarged polycystic kidneys were completely alike with respect to the type of involvement and differed only in the severity of changes. They could be identified as type III cystic kidneys according to the classification of Potter. Proliferation of hepatic bile ducts and slight cystic dilatation of pancreatic ducts is already evident in the youngest fetus. Additional cyst formation in the epididymis was found in one of the cases. Occipital encephalocele, located within an apical occipital bone defect was always associated with a second mostly occult encephalocele protruding through a separate defect of the basal occipital squame and of the first and second vertebral arch. It is assumed that double encephalocele represents a constant finding in Meckel's syndrome, indicating a specific pattern within the disturbance of neural tube closure.     

Maternal serum CA 125 levels in pregnancies with chromosomally-normal and -abnormal fetuses

We measured the maternal serum cancer antigen 125 (MS-CA 125) levels in 98 nonpregnant women, 765 first- and second-trimester pregnancies with chromosomally-normal fetuses, and 54 chromosomally-abnormal pregnancies. To determine the MS-CA 125 concentration, we used a new automated microparticle enzyme immunoassay with low inter-assay variability. The median MS-CA 125 level decreased from the first to the second trimester of pregnancy and was higher than that in non-pregnant women. We found no difference between normal and Down's syndrome (n = 29) pregnancies ( t-test: t = 0·57, p >0·5). The MS-CA 125 levels in pregnancies with other chromosomal abnormalities showed no difference either, compared with the normals. We conclude that MS-CA 125 is not a useful marker for fetal Down's syndrome, nor for other chromosomal disorders in pregnancy.     

固态聚合氯化铝的27Al NMR研究

聚合氯化铝(PAC)是一种水处理混凝剂,可为液态(PAC-L),也可浓缩成固体(PAC-S)、PAC-L在水中稀释时铝的形态的变化已用~(27)Al核磁共振法(NMR)进行了研究。本工作试图用~(27)Al NMR法对PAC-S及其在水中溶解稀释物中铝的形态进行研究,以探讨固化对PAC及其在水中铝的形态的影响。     

Value of maternal serum unconjugated oestriol measurement in prenatal screening for Down's syndrome

We compared the medical and financial cost-effectiveness of prenatal serum screening for Down's syndrome using maternal age, serum alpha-fetoprotein and human chorionic gonadotrophin with and without the use of unconjugated oestriol. The use of unconjugated oestriol is medically more cost-effective than screening without it at all levels of detection. The actual performance depends on whether gestational age is estimated using ‘dates’ or an ultrasound scan. At a detection rate of 60 per cent, the proportion of unaffected fetal losses per case diagnosed at amniocentesis is about 22 per cent less if gestational age is estimated using dates (time since the first day of the last menstrual period) and about 47 per cent less if it is based on an ultrasound scan examination. At this detection rate, the inclusion of unconjugated oestriol increases costs by about £2k per case diagnosed (£36k instead of £34k) if gestational age is estimated using dates, but it is no more expensive if gestational age is measured from an ultrasound scan examination (indeed, it is more cost-effective at detection rates above 60 per cent). Since there is little change in the financial cost with the inclusion of unconjugated oestriol, for the improved medical performance of screening, it is worthwhile including it in the screening test.     

Amniotic fluid pregnancy-specific β1-glycoprotein (SP1) in fetal developmental disorders

Concentration of pregnancy-specific β1-glycoprotein (SP1) was studied in second and third trimester amniotic fluid from pregnancies with various fetal developmental disorders. The material consisted of 26 cases with chromosomal disorders and 19 cases with nonchromosomal fetal malformations. The SP1 concentration was elevated in two cases of Meckel's syndrome (mean + 2.7–4.0 S.D.) as well as in one case of fetal triploidy (mean + 22 S.D.), while it was normal in all other 14 different fetal disorders.     

Maternal serum free α- and free β-human chorionic gonadotrophin in pregnancies with insulin-dependent diabetes mellitus: Implications for screening for Down's syndrome

A study was performed to investigate the concentrations of the α and β free sub-units of human chorionic gonadotrophin (free α-hCG and free β-hCG) in maternal serum between 15 and 22 weeks of pregnancy in 126 pregnancies among 92 women with insulin-dependent diabetes mellitus (IDDM). Each IDDM pregnancy was matched with two control singleton pregnancies for gestational age (same completed week) and duration of sample storage (same calendar quarter). The median free α-hCG level in the IDDM pregnancies was 0·86 multiples of the median (MOM) for pregnancies without IDDM at the same gestational age (P<0·002) (95 per cent confidence interval 0·80–0·94). The corresponding free β-hCG level was 0·96 MOM (95 per cent confidence interval 0·85–1·09). These results enable free α-hCG values to be adjusted so that antenatal screening for Down's syndrome can be performed using this marker in IDDM pregnancies as well as in non-diabetic pregnancies.     

青海省海东市平安区土壤Se的地球化学特征

通过对平安区表层土壤样品的系统采集,测定了Se及其它元素的含量,研究了区内土壤Se的地球化学特征,探讨土壤Se富集机理。结果表明,表层土壤Se处于0.04～5.79 mg/kg之间,均值为0.29 mg/kg,富Se(Se≥0.4 mg/kg)和足Se(0.175≤Se0.4 mg/kg)土壤面积分别为121.4 km~2和464.1 km~2,总共占平安区总面积的75.1%,主要分布在古-新近纪棕红色泥岩风化物和第四纪冲洪积物为母质的土壤区。富Se土壤存在两个区带,分布位于平安盆地和拉脊山。平安区Se富集机理主要有两种:平安盆地Se与Sr、Mo活动相近,在咸水、干旱、氧化的沉积环境与盐类物质同时发生富集;拉脊山Se与Cu、S、Mo活动相近,与铜硫化物伴生并受表层高有机质吸附所致。     

Alpha-fetoprotein and ultrasound scanning in the prenatal diagnosis of Turner's Syndrome

Based on data from 5 cases of fetal cystic hygroma (4 cases of Turner's Syndrome and one case of Trisomy 18) and one case of Down's Syndrome with severe subcutaneous oedema, it is concluded that amniotic fluid alpha-fetoprotein (AFP) is normal or only slightly elevated in such cases whereas AFP in fluid from the cystic structures is very high. Reported high values of ‘amniotic fluid’ AFP are therefore likely to have been obtained from fluids accidentally drawn from the cystic structures. Fluids from the two sources cannot be distinguished from each other visually. In support of this theory is that the maternal serum AFP was found to be normal in all cases where investigated. In the diagnosis of cystic hygromata detailed ultrasound scanning will reveal the correct diagnosis.     

Sonographic presentation of Hirschsprung's disease. A case of an entirely aganglionic colon and ileum

Prenatal sonographic presentation of Hirschsprung's disease has been considered non-specific and uncommon. This report presents a second-trimester fetus with an aganglionic colon and ileum diagnosed by the sonographic presentation of dilated fetal bowel loops, increased abdominal circumference, and mild polyhydramnios. The prenatal sonographic diagnosis of Hirschsprung's disease helped to expedite early neonatal treatment.     

First-trimester biochemical screening for fetal chromosome abnormalities and neural tube defects

Alpha-fetoprotein (AFP), unconjugated oestriol (UE3), intact human chorionic gonado-trophin (intHCG), and the free β subunit of chorionic gonadotrophin (FβHCG) were investigated in a series of 21 chromosomally abnormal and 14 open neural tube defect pregnancies ascertained from a series of 14 000 prospectively collected maternal serum samples at 6–14 weeks' gestation. In 16 cases of Down's syndrome, significant reductions were found for AFP (0.65 multiples of the normal median) and UE3 (0.67 MOM). IntHCG levels were unaltered (0.97 MOM) but a significant increase was found for FβHCG (1.96 MOM). Significant correlations were found for AFP and UE3 in the controls and for int HCG and FβHCG in both the control and the Down's syndrome pregnancies. In a group of five trisomy 18 pregnancies, median MOMs were for AFP 0. 71 , for UE3 0. 34 , for intHCG 0. 27 , and for FβHCG 0.15. None of 13 pregnancies with open neural tube defects at 8-13 weeks gestation had elevated maternal serum AFP levels, whereas matched second-trimester samples from the same pregnancies at 16-18 weeks gestation all had significantly elevated AFP levels. Thus, biochemical screening for chromosome abnormalities may be practicable in the first trimester using free β human chorionic gonadotrophin in combination with AFP and maternal age. However, a separate screening protocol using AFP at 15-18 weeks gestation would still be required for effective detection of neural tube defects.