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61.
Stickler syndrome is an autosomal dominant disorder of the connective tissue which includes ocular and systemic manifestations. We report on a large kindred in which we were able to demonstrate very tight linkage between the disease and the type II collagen gene (COL2A1) (LOD score 3·91 at θ=0). In a family in which the father and one of his daughters were severely affected, DNA analysis from a chorionic villus sample demonstrated that the fetus possessed the normal allele of COL2A1. Thereafter a normal child was born.  相似文献   
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We have determined the activity of alkaline phosphatase in chorionic villous tissue obtained in the first trimester of pregnancy, in order to obtain the normal range of values as a prerequisite for application to the prenatal diagnosis of the rare bone disease hypophosphatasia. The activities found were a combination of intestinal and liver/bone/kidney types; traces of placental type were present in only one sample.  相似文献   
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Multiple placental passes during chorionic villus sampling (CVS) increase the risk of fetal loss; however, specific factors that predispose to repeat aspiration have not been delineated. To identify anatomic and technical variables associated with multiple-pass procedures, a detailed review of 205 videotaped CVS procedures (single pass = 163; multiple pass = 42) was performed, blinded to pregnancy outcome. The route of sampling did not influence the need for multiple aspiration attempts (transabdominal—30/ 135; transcervical—12/70), nor was placental location alone discriminatory. However, the combination of a posterior placenta and uterine retroversion was observed more frequently in the multiple-pass cohort (8/42 vs. 9/163; p<0.05). In transabdominal cases, suboptimal needle placement (e.g., perpendicular to the placental long axis) was more common in the initial aspiration of a multiple-pass procedure (21/30 vs. 38/105;p<0.01), while limited penetration of the catheter tip (e.g., just inside the placental edge) characterized a majority of multiple-pass cases in the transcervical subset (7/12 vs. 3/58; p<0.0001). A case-control cohort was constructed to evaluate the impact of these technical variables on sampling efficacy, independent of the influence of uterine position and placental site. In that analysis, suboptimal location and/or orientation of the sampling device remained characteristic of multiple-pass cases. We conclude that further reduction in the frequency of multiple-pass procedures might be achieved by consistent placement of the device tip in the central placental mass. Unlike amniocentesis, where any point of amnion entry will suffice, this technical nuance should be emphasized with CVS to maximize the single-pass success rate.  相似文献   
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We describe the prenatal diagnosis of isolated bilateral fetal microphthalmia in a woman at increased risk of having a fetus with microphthalmia. Ultrasound examinations at 161 and 19-5 weeks' gestation demonstrated bilateral fetal microphthalmia with no other associated structural defects. The patient elected to terminate her pregnancy at 19.5 weeks. Pathological evaluation of the products of conception obtained by dilation and evacuation confirmed the prenatal diagnosis of isolated bilateral fetal microphthalmia.  相似文献   
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This paper considers relationships between sustainability objectives, transport, spatial design of the built environment and rational use of energy. Conventional transport modelling, housing supply and energy assessment tools are drawn together to provide a common platform for appraisal of city-wide energy use by stationary and mobile sources. The paper outlines methodologies developed for the city of Belfast, Northern Ireland. The paper concludes by briefly reviewing the effect in terms of mobile and stationary energy consumption and travel behaviour of implementing sustainable policy measures in current and future years within the study area.  相似文献   
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Mitigation and Adaptation Strategies for Global Change -  相似文献   
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