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11.
Howard Cuckle Nicholas Wald Rossana Stone James Densem James Haddow George Knight 《黑龙江环境通报》1988,8(6):439-445
Thyroid antibodies were measured in mid-trimester antenatal serum samples from 77 pregnancies affected by fetal Down's syndrome and 385 unaffected control pregnancies. Using a haemagglutination technique, thyroglobulin antibodies were detected in 5·2 per cent of cases (4) and 2·9 per cent of controls (11), and thyroid microsomal antibodies were detected in 22 per cent (17) and 15 per cent (59), respectively. Using an enzyme-linked immunosorbent assay (ELISA) for thyroglobulin antibodies and a cut-off level of 50 KIU/1, positive results were found in 25 per cent of cases (19) and 22 per cent of controls (84). Using an ELISA for thyroid microsomal antibodies and the same cut-off level, the proportions were 52 per cent (40) and 39 per cent (149), respectively. While not statistically significant, the differences were consistent with the previously reported increased levels of thyroid antibody found in nonpregnant women who had had pregnancies associated with Down's syndrome. 相似文献
12.
Frances R. Sweetman Kenneth M. Gibson Lawrence Sweetman Ph.D William L. Nyhan Homer Chin William Swartz Oliver W. Jones 《黑龙江环境通报》1986,6(3):187-194
We have documented the presence of five mitochondrial enzymes in samples of chorionic villus tissue and measured the levels of activity. Three of the enzymes catalyse biotindependent reactions. These are propionyl-CoA carboxylase, 3-methylcrotonyl-CoA carboxylase and pyruvate carboxylase. the other enzymes. 4-aminobutyric acid aminotransferase and succinic semialdehyde dehydrogenase, are involved inthe degradation of the central inhibitory neurotransmitter GABA. Distinct diseases in whichthere is deficiency of each of these enzymes have been documented in man. Significant levels of activity were observed for all five enzymes in chorionic villus tissue. This methodology should permit early prenatal diagnosis of deficiencies of these enzymes by chorionic villus biopsy in the first trimester. 相似文献
13.
14.
Maternal serum inhibin levels were measured in 19 second-trimester pregnancies affected by fetal Down's syndrome and 95 unaffected control pregnancies matched for gestational age. A statistically significant elevation was found in the affected pregnancies compared with the controls (Wilcoxon rank sum test: one-tail P=0·02). The median level in the cases was 1·3 times that in the controls, with 95 per cent confidence limits of 0·9–1·9. Although the inhibin levels were unrelated to those of alpha-fetoprotein and unconjugated oestriol in the same samples, there was a statistically significant correlation with human chorionic gonadotropin. This together with the relatively small elevation in cases suggests that inhibin would be of limited value in maternal serum screening for Down's syndrome. 相似文献
15.
A case of fatal generalized dystrophic epidermolysis bullosa is described in a prematurely born female whose mother had strikingly elevated mid-trimester serum and amniotic fluid alpha-fetoprotein concentrations, a positive amniotic fluid acetylcholinesterase band, and negative serial ultrasound studies. This case lends further support to an association between autosomal recessive generalized dystrophic epidermolysis bullosa and increased levels of alpha-fetoprotein, positive amniotic fluid acetylcholines'terase, and normal ultrasound findings. 相似文献
16.
H. Cuckle N. Wald J. D. Stevenson H. M. May M. A. Ferguson-Smith A. Milford Ward H. M. Barbour K. M. Laurence B. Norgaard-Pedersen 《黑龙江环境通报》1990,10(2):71-77
Data on maternal serum alpha-fetoprotein (AFP) levels at 13–24 weeks' gestation in 46 twin pregnancies with open neural tube defects (22 with anencephaly, 24 with open spina bifida) and 169 unaffected twins were used to estimate the detection and false-positive rates associated with different cut-off levels. Using the conventional cut-off level of 2·5 multiples of the median (MoM) for unaffected singleton pregnancies of the same gestation and laboratory, the detection rate in twins was 99 per cent for anencephaly and 89 per cent for open spina bifida, with a false-positive rate of 30 per cent. Using a 5·0 MoM cut-off level to maintain a similar false-positive rate to that found among singleton pregnancies at 16–18 weeks' gestation (about 3 per cent), the detection rate was 83 per cent for anencephaly and 39 per cent for open spina bifida. Estimates are provided of the odds of having an affected twin pregnancy given a positive AFP result as well as the odds for individual women with a raised AFP level. 相似文献
17.
J. G. Hooker M. Lucas B. A. Richards I. M. Shirley B. D. Thompson R. H. T. Ward 《黑龙江环境通报》1984,4(1):29-33
Estimation of maternal serum alpha-fetoprotein (AFP) was used as a screening method for the detection of neural tube defects (NTDs) in 6344 women over three years. Of 88 (1.4 per cent) who had one or more serum AFP levels equal to, or greater than, 2.5 multiples of the median (MoM) for the relevant gestational age, 43 (0.68 per cent) underwent amniocentesis. There were eight NTDs. Four of these were screened by serum AFP, and all cases of spina bifida had serum AFP levels greater than 3.0 MoM, including one small open defect which was not seen on ultrasound. The other four cases of NTD, which were not screened, were identified by ultrasound. Of 64 singleton pregnancies 32 (50 per cent) had serum AFP levels between 2.5 and 3.0 MoM, and low birthweight (⪕2500 g) occurred in 29 per cent. Because of improvements in ultrasound techniques and the apparent falling incidence of NTD, the role of serum AFP as the primary screening procedure should be regularly reviewed. Effective screening is dependent on mothers booking early. 相似文献
18.
荧光光谱法研究丙酮与牛血清白蛋白的相互作用特征 总被引:6,自引:0,他引:6
在模拟动物体生理条件和不同温度下,用荧光光谱、三维荧光光谱、同步荧光光谱、紫外可见吸收光谱法等研究了丙酮(ACET)与牛血清白蛋白(BSA)的相互作用,证实了丙酮有很强的猝灭BSA荧光强度的能力.分别用Sterr-Volmer方程、Lineweaver-Burk双倒数方程和热力学方程等分析和处理试验数据,得到了它们相互作用的生成常数KLV(平均值为7.073×106L·mol-1)、热力学参数(△Hθ、△Gθ和△Sθ的平均值分别为-3.982kJ·mol-1、-26.51 kJ·mol-1和73.31J·K-1)和结合位点数(平均值为1.266)等.这为研究ACET对BSA构象的影响、ACET的毒理效应和生物学效应提供了重要信息. 相似文献
19.
B. N. Chodirker M.D. A. E. Chudley K. M. Macdonald C. R. Harman J. A. Evans 《黑龙江环境通报》1994,14(11):1086-1089
This study was undertaken to evaluate the relationship between maternal serum alpha-fetoprotein (MSAFP) levels and oesophageal atresia (OA). OA occurred in 16 fetuses of mothers who had an MSAFP test in the study interval. The multiple of the median (MOM) value for MSAFP averaged 1·54 ± 0·65 (range 0·5–2·9 MOM), which was significantly higher than the value seen in controls. The median MOM was 1·35. Using a cut-off of 2·5 MOM, the sensitivity of MSAFP for detecting OA was 19 per cent. Although OA should be considered in the differential diagnosis of an elevated MSAFP level, MSAFP cannot be considered an appropriate screening test for OA given the low sensitivity. 相似文献
20.
The value of maternal serum pregnancy-associated plasma protein (PAPP)-A in screening for Down syndrome in early pregnancy was assessed using stored samples. Seventeen cases of Down syndrome and 66 unaffected control pregnancies were studied. The median PAPP-A level in the cases was 0.42 multiples of the expected value in controls (p <0.0001). Eleven cases (65 per cent) had levels less than half the expected value compared with only six controls (9 per cent). A commercial assay kit is now needed so that prospective screening with this marker can begin. 相似文献