Fetal renal anomalies and genetic syndromes

Renal abnormalities are some of the commonest and most easily detectable anomalies on ultrasound. Many are an isolated finding but the prognosis may be altered considerably by the detection of other anomalies which could indicate a genetic disorder or syndrome. It is often easier to detect presupposed anomalies and the purpose of this article is to introduce and discuss those syndromes that may present with a renal abnormality on ultrasound. Common renal findings are presented with the range of additional anomalies that should be sought and suggested diagnostic tests. It should be remembered that although for many genetic conditions specific mutation analysis is now available, this usually requires pre‒pregnancy investigations. Furthermore, in some cases the definitive diagnosis may not be suspected until post mortem. By this time it may be too late to establish a cell line to confirm the suspicion using laboratory methods. It is therefore important to take tissue samples antenatally where possible, or at delivery, as postnatal samples may have a high culture failure rate. Copyright © 2001 John Wiley & Sons, Ltd.     

Role of amniotic fluid interphase fluorescence in situ hybridization (FISH) analysis in patient management

We retrospectively reviewed 309 amniotic fluid interphase fluorescence in situ hybridization (FISH) analyses performed from October 1995 to June 1999 to assess the role of interphase FISH in the management of patients at increased risk for fetal aneuploidies. Gestational age and indications for amniocentesis, clinical interventions after FISH results, as well as interventions after final culture reports were analyzed. There were 244 (79%) normal, 50 (16%) abnormal and 15 (5%) inconclusive FISH results. There were no false-positive or false-negative results, but there were nine (3%) clinically significant chromosomal abnormalities not detectable by FISH. Of the 50 women with abnormal FISH results, 26 (52%) elected to terminate the pregnancy prior to the availability of the standard chromosome analysis. In two of the fetuses with trisomy 21 no abnormalities were reported by ultrasound examination. Our experience indicates that interphase FISH results played an important role in decision making, especially for pregnancies close to 24 weeks' gestation. Standard karyotype analysis is still required for detection of chromosome abnormalities not detectable by interphase FISH techniques and for clarification of unusual or inconclusive FISH results. Copyright © 2001 John Wiley & Sons, Ltd.     

消融的冰川：加拿大班夫国家公园亚高山带鲍湖中持久性有机氯的主要来源

有机氯杀虫剂和多氯联苯（PCB）是环境中普遍而稳固的化合物。现已查明，由于它们从温暖的地区逐渐蒸发出来，并在较冷的地区凝聚下来，因而它们富集在寒冷的环境中。在本研究中，我们的结果是，消融的冰川供给阿尔伯达亚高山带湖泊中的有机氯输入量为50%～97％，而提供的水量为73％。对氚的分析结果表明，在夏季的中、晚期，至少10％的冰川消融物是在1950～1970年期间沉积下来的，这期间它受到有机氯更多的污染。这一发现表明，气候变暖可能会使消融的冰川成为日益增多的淡水污染物来源。由于有机物贫乏的冰川粘土对多氯联苯这样的疏水化合物的吸附能力有限，因此冰川水流带来的有机氯大多呈溶解状态。