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251.
Cytomegalovirus (CMV) is the most common cause of congenital infection. Recent studies show amniocentesis to be a 100 per cent sensitive and 100 per cent specific predictor of congenital infection, and recommend that it be offered in the at-risk pregnancy. However, these publications have focused on pregnancies at or beyond 22 weeks' gestation. Here, we report a case of maternal CMV hepatitis at 7–8 weeks' gestation, in which culture and polymerase chain reaction testing for CMV in amniotic fluid at 20 weeks' gestation were negative, but the infant had a positive CMV urine culture shortly after delivery. Implications for the prenatal diagnosis of CMV infection are discussed. 相似文献
252.
We report the detection of 42 cases of musculoskeletal anomalies routinely screened by transvaginal sonography at 12-16 weeks of gestation out of 7325 examined pregnant women (incidence of 0·57 per cent). 相似文献
253.
The effect of bridge shading on estuarine marsh food webs was assessed by comparing benthic invertebrate communities beneath seven highway bridges with marshes outside of bridge-affected areas (reference marshes). We used light attenuation and height–width ratio (HW ratio), which takes into account the two main bridge characteristics that determine the degree of shading, to quantify the impact of shading on invertebrate communities. Low bridges, with HW ratio <0.7 and light attenuation greater than 85–90%, had benthic invertebrate densities and diversity that were significantly lower than reference marshes. Density of benthic invertebrates at low bridges was 25–52% (29,685–72,920 organisms/m2) of densities measured in adjacent reference marshes (119,329–173,351 organisms/m2). Likewise, there were fewer taxa under low bridges (5.8/11.35 cm2 core) as compared to the reference marshes (9.0/11.35 cm2 core). Density of numerically dominant taxa (e.g., oligochaetes and nematodes) as well as surface- and subsurface deposit feeders also were reduced under low bridges. Decreased invertebrate density, diversity, dominant taxa, and alterations of trophic feeding groups beneath low bridges was correlated with diminished above- and below-ground macrophyte biomass that presumably resulted in fewer food resources and available refuges from predators. With a greater knowledge of bridge shading effects, bridge construction and design may be improved to reduce the impacts on estuarine benthic invertebrate communities and overall ecosystem structure and function. 相似文献
254.
By chance, we had the opportunity to make serial sonographic observations of the extrusion of meconium in a case of meconium peritonitis. Inflammation leads to exudative processes and production of fluid (ascites) in the fetal abdomen. Sonography at that stage of the disease may lead to a misdiagnosis such as ‘fetal ascites’ or ‘non-immune hydrops’. After bowel perforation and extrusion of meconium, the latter appears as a solitary mass inside fetal ascites or as disseminated echogenic masses distributed subdiaphragmatically or perihepatically. Within a couple of days, in most cases the echogenicity of the masses increases. Calcifications lead to distinct shadowing. These calcifications are often the only visible signs of a previous meconium peritonitis. Serial sonograms are essential for the management of pregnancies with meconium peritonitis. If the amount of fetal ascites does not increase and no signs of cardiovascular stagnation appear, no invasive intrauterine diagnostic and therapeutic steps are required. In none out of the nine cases was a cause found. 相似文献
255.
256.
R. H. Sijmons MD B. Sikkema-Raddatz M. D. Kloosterman J. W. Briet B. De Jong N. J. Leschot 《黑龙江环境通报》1995,15(3):285-290
Chorionic villus sampling (CVS) was performed on a 40-year-old woman at 9 1/2 menstrual weeks because of advanced maternal age. The direct preparation showed 46,XY,dup(10)(q11.2q23.2). CVS long-term culture and fetal tissue revealed a rare additional abnormality: 48,XXXY,dup(10)(q11.2q23.2). This abnormality represented the major cell line (>85 per cent in 691 cells) in an (XY)/XXY/XXXY/(XXXXY) mosaic (all cell lines presumably bearing the dup(10q); the presence of XY and XXXXY cell lines is uncertain). To our knowledge, this is the first report of trisomy 10q11-q23 and of prenatally detected 48,XXXY in chorionic villi. The mosaic could have resulted from early post-zygotic non-disjunctions in a 46,XY,dup(10q) or 47,XXY,dup(10q) zygote. The results from DNA studies of four polymorphisms, mapped to Xp and Xq, support this theory. The literature on prenatally detected cases with sex chromosome tetrasomy and pentasomy and those with additional autosomal abnormalities is reviewed. The reported case underlines the problem of false-negative findings when only direct CVS preparations are karyotyped. 相似文献