Prenatal diagnosis of thalassemia: The viewpoint of patients

Twenty-eight young people with thalassemia major expressed their opinion about prenatal diagnosis. All of them stated that they intended to marry and have children; thirteen of them (46 per cent) said that they would have also accepted a thalassemic carrier as a partner and that if married to a carrier they would have undergone prenatal diagnosis and selective abortion. All but one refused the prospect of an affected child. When asked if they would have preferred that before their birth their parents had undergone prenatal diagnosis and abortion, 19 patients (68 per cent) gave an affirmative answer. These results clearly indicate that even people affected by thalassemia major, who are the potential victims of prenatal diagnosis and selective abortion, largely accept prenatal diagnosis as a means of preventing their disease.     

Prenatal diagnosis of pyruvate dehydrogenase E1α subunit deficiency

Pyruvate dehydrogenase (PDH) E1α subunit deficiency is an X-linked inborn error of metabolism affecting males and females with equal frequency. The diagnosis is usually based on determination of enzyme activity, although this may present difficulties in some females because of X-inactivation patterns favouring expression of the normal X chromosome. This is a particular problem for prenatal diagnosis using chorionic villus cells where normal enzyme assay results do not necessarily exclude the diagnosis and confirmatory X-inactivation analysis may be complicated by variable methylation of active and inactive X chromosomes. We describe prenatal diagnosis in two pregnancies in a family following diagnosis of a PDH E1α deficient male. The first prenatal diagnosis was performed by enzyme assay, but by the time of the subsequent pregnancy, the underlying mutation in the affected male had been identified and direct gene analysis was possible. This study highlights the limitations of diagnosis of PDH E1α deficiency based on measurement of the gene product and illustrates the need for mutation analysis in affected individuals.     

Antenatal sonographic diagnosis of arthrogryposis multiplex Congenita

Arthrogryposis Multiplex Congenita (AMC) was suspected on ultrasound examination of a fetus at 30·5 weeks of gestation. The criteria for establishing this prenatal diagnosis as well as the importance of establishing the diagnosis at any gestational age are discussed. The diagnosis of AMC was confirmed at birth in this case.     

Prenatal diagnosis of an intra-abdominal sacrococcygeal teratoma

The prenatal diagnosis of a presacral (type IV) sacrococcygeal teratoma (SCT) is described. The initial ultrasound appearance was suggestive of a lower urinary tract obstruction, but further ultrasonic examination and radiological imaging using contrast medium led to the diagnosis of SCT. This is the first prenatal diagnosis of a totally intra-abdominal SCT.     

DNA-based carrier detection and prenatal diagnosis of tyrosinase-negative oculocutaneous albinism (OCA1A)

We describe molecular prenatal diagnosis and carrier detection of tyrosinase-negative oculocutaneous albinism (OCA1A) in two families. In one family, we carried out DNA-based prenatal diagnosis of OCA1A. In the other family, mutation analysis and carrier detection obviated the need for prenatal diagnosis. Molecular analysis is safer and probably more accurate than fetoscopy and fetal scalp biopsy, and should become the method of first choice for prenatal diagnosis of OCA1.     

基于人工免疫算法的离散隐马尔科夫故障诊断模型优化

目的解决离散隐马尔科夫模型在行星齿轮箱故障诊断中的自适应性和泛化性问题。方法建立人工免疫优化模型,将包含易被误判样本的多样本集作为抗原,以其正确识别率为适应度函数,不断对初始观测矩阵进行增殖、变异和选择,获得识别率最高时的初始观测矩阵,利用人工免疫算法对隐马尔科夫故障诊断模型的初始观测矩阵进行优化。结果将该方法应用于行星齿轮箱的故障诊断中,通过不同工况下的对比试验、单样本和多样本优化对比试验,验证了优化后的隐马尔科夫故障诊断模型的诊断效果。结论优化后的隐马尔科夫故障诊断模型具有更好的适应性,诊断精度显著提高。     

海洋平台不间断电源锂离子蓄电池故障诊断

目的针对海洋平台不间断电源(Uninterrupted Power Supply,UPS)可靠性要求高,工作环境复杂等特点,建立一种基于多模型粒子滤波的海洋平台UPS故障诊断系统。方法该系统基于飞思卡尔芯片建立各模块间的通信,并根据锂离子电池故障实验后的参数建立故障模型,通过条件概率对海洋平台UPS的正常、过充、过放和过热四类状态进行诊断,提高海洋平台UPS的可靠性。结果使用部分实验所得数据测试了诊断系统对单一故障和复合故障诊断的结果,得到诊断算法对过充、过放和过热三种故障的诊断时间在5 s以内,准确率极高。结论测试结果显示,设计得到的海洋平台UPS故障诊断系统可以准确迅速地诊断故障类型。     

Consequences of prenatal diagnosis of cystic fibrosis on the reproductive attitudes of parents of affected children

Three hundred and twenty-six French families with a cystic fibrosis-affected child who were referred for prenatal diagnosis were analysed by sibship size: 74.2 per cent of the couples had no further pregnancies to term after the affected child, who was deceased in 34.6 per cent of cases. These couples were followed prospectively after prenatal diagnosis and 77 had two or more consecutive pregnancies with prenatal diagnosis. The aim of these couples was to succeed in constituting a family with two normal children.     

Prenatal diagnosis of cystinosis utilizing chorionic villus sampling

The prenatal diagnosis of cystinosis is currently based on the increased amount of free-cystine present in amniotic fluid cells. Amniocyte cultures must be grown for at least 2 weeks to obtain sufficient cells for such measurements. Thus, the diagnosis cannot be made until close to 20 weeks gestational age by this method. We report a case in which chorionic villi were used for direct cystine measurement resulting in the in utero diagnosis of cystinosis at 9 weeks gestational age. The diagnosis was confirmed by the study of cultured chorionic villus cells, and of the 10-week abortus.     

First-trimester diagnosis of conjoined twins

Conjoined twins are a rare and complex complication of monozygotic twinning, which is associated with high perinatal mortality. Early prenatal diagnosis of conjoined twins allows better counselling of the parents regarding the management options, including continuation of pregnancy with post-natal surgery, termination of pregnancy or selective fetocide in case of a triplet pregnancy. With the introduction of high-resolution and transvaginal ultrasound imaging, accurate prenatal diagnosis of conjoined twins is possible early in pregnancy. We have reviewed the medical literature on the early prenatal diagnosis of suspected conjoined twins using a MEDLINE search. Although first-trimester diagnosis of conjoined twins is feasible, false-positive cases are common before 10 weeks because, earlier in gestation, fetal movements are limited and monoamniotic twins may appear conjoined. As most parents opt for immediate termination of pregnancy at confirmation of the diagnosis, there are limited data on the prenatal follow-up of conjoined twins. When the parents opt for conservative management, half of the fetuses die in utero and another 44% will die during the neonatal period. A detailed analysis of case reports where 3D imaging was used indicates that this modality does not improve on the diagnosis made by 2D ultrasound. Overall, very early prenatal diagnosis and first-trimester 3D imaging provide very little additional practical medical information compared to the 11–14 weeks' ultrasound examination. Copyright © 2005 John Wiley & Sons, Ltd.     

Ultrasound diagnosis of the pena shokeir phenotype at 14 weeks of pregnancy

This report describes the early prenatal diagnosis of the Pena Shokeir phenotype in an at-risk patient at 14 weeks' gestation. The diagnosis was based on an abnormal fetal movement profile, in association with an abnormal position of the fetal limbs. Pena Shokeir phenotype describes an inherited condition characterized by arthrogryposis and dysmorphic features as a result of fetal akinesia. It is a lethal abnormality and early diagnosis allows safer surgical methods of termination.     

Prenatal diagnosis of carbamoyl-phosphate synthetase deficiency by fetal liver biopsy

In a pregnancy at risk for carbamoyl-phosphate synthetase (CPS) deficiency, prenatal diagnosis was attempted by fetal liver biopsy, performed at 18 weeks of gestation. CPS activity was absent and the diagnosis was confirmed after termination of the pregnancy. The technique employed for fetal liver biopsy is described together with an evaluation of its possible role in prenatal diagnosis.     

Partial trisomy 20p resulting from recombination of a maternal pericentric inversion: case report of a prenatal diagnosis by chorionic villus sampling

We report a case of prenatal diagnosis of trisomy 20p resulting from a maternal pericentric inversion. The diagnosis was confirmed on both chorionic villi and amniotic cells. This case underlines the fact that prenatal ultrasound diagnosis of this structural anomaly is difficult. The only early sonographic feature was increased nuchal translucency. Copyright © 2006 John Wiley & Sons, Ltd.     

土壤污染的生态毒理诊断

土壤污染诊断是土壤清洁过程中必不可少的重要环节。然而，单纯依靠化学方法进行土壤污染诊断，不能表征土壤的整体质量特征，因此需要生态毒理诊断方法做补充。以土壤生态毒理诊断研究为主线，对土壤污染生态毒理诊断的特殊性、重要性、客观需求以及现有诊断研究等国内外现状进行了综述并对发展前景进行展望。     

Prenatal molecular diagnosis of gaucher disease

Prenatal diagnosis of Gaucher disease, the most prevalent glycolipid storage disease, is based on a reliable enzyme assay of cells from amniocentesis or chorionic villous samples. However, this method cannot differentiate among the various forms of the disease. This report details four cases of prenatal diagnosis of Gaucher disease, three of which predate the use of molecular diagnosis. DNA mutation analysis to determine the genotype was predictive of the phenotypic status of the fetus and conformed to the genotype of an affected proband where available.     

Prenatal genetic considerations of congenital anomalies of the kidney and urinary tract (CAKUT)

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute 20% of all congenital malformations occurring in one in 500 live births. Worldwide, CAKUT are responsible for 40% to 50% of pediatric and 7% of adult end-stage renal disease. Pathogenic variants in genes causing CAKUT include monogenic diseases such as polycystic kidney disease and ciliopathies, as well as syndromes that include isolated kidney disease in conjunction with other abnormalities. Prenatal diagnosis most often occurs using ultrasonography; however, further genetic diagnosis may be made using a variety of testing strategies. Family history and pathologic examination can also provide information to improve the ability to make a prenatal diagnosis of CAKUT. Here, we provide a comprehensive overview of genetic considerations in the prenatal diagnosis of CAKUT disorders. Specifically, we discuss monogenic causes of CAKUT, associated ultrasound characteristics, and considerations for genetic diagnosis, antenatal care, and postnatal care.     

基于GIS的耕地土壤养分贫瘠化评价及其障碍因子分析

论文在山东省禹城市开展的系统土壤调查采样和室内化验分析获得的土壤养分各要素数据信息基础上,在GIS技术支持下,综合利用采样点养分要素和空间信息数据,通过建立土壤"阈值样点"、利用层次分析法(AHP)等方法改进灰色关联等级评价模型,实现了土壤养分贫瘠化评价定量化,引入障碍因子诊断模型对引起禹城市土壤养分贫瘠化的因子进行障碍诊断。评价利用Kriging空间插值技术获取了研究区土壤贫瘠化状况、主要障碍因子的空间分布信息,与实地调查分析结果相符,表明运用该技术方法对土壤贫瘠化评价和障碍因子诊断的可行性和科学性。该法开展的贫瘠化状况评价和障碍因子诊断对土壤资源的科学管理和可持续利用具有积极意义,并可为研究区提升土壤质量提供科学参考。     

First trimester diagnosis of lesch-nyhan syndrome: Applications to other disorders of purine metabolism

The prenatal detection of hypoxanthine phosphoribosyltransferase (HPRT, EC 2.4.2.8) deficiency, the Lesch-Nyhan syndrome, during the first trimester of an affected pregnancy through the use of chorionic villus sampling is reported. Quantitation of reaction products formed by villus cell extracts from exogenous hypoxanthine-8-[¹⁴C] or adenine-8-[¹⁴C] is used in diagnosis. We report the diagnosis of Lesch-Nyhan syndrome using a chorionic villus specimen and confirmation of that diagnosis. In addition, adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP), enzymes deficient in inherited immune disorders, are detected in chorionic villus samples. These heritable disorders also appear amenable to early prenatal diagnosis.     

Rapid prenatal diagnosis of Duchenne muscular dystrophy with gene duplications by ion-pair reversed-phase high-performance liquid chromatography coupled with competitive multiplex polymerase chain reaction strategy

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are caused by various mutations in the dystrophin gene. Rapid prenatal diagnosis of DMD with gene duplications is difficult due to limitation in gene dosage determination and the requirement for a known disease-causing mutation in the pedigree to achieve a rapid and accurate diagnosis. We report, here, a case with rapid prenatal diagnosis of DMD-affected male with gene duplications in the absence of a known disease-causing variation in the pedigree by using ion-pair reversed-phase high-performance liquid chromatography (IP-RP-HPLC) coupled with competitive multiplex polymerase chain reaction (PCR) protocol. In cases with clinical diagnosis of DMD/BMD, this test should identify greater than 92% of disease-causing DNA variants. The postnatal genetic diagnosis of this case and the same disease-causing mutations subsequently identified in other members of the pedigree confirmed the accuracy of competitive multiplex PCR/IP-RP-HPLC assay in direct prenatal diagnosis of DMD. Copyright © 2007 John Wiley & Sons, Ltd.     

First report of prenatal diagnosis of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency in a pregnancy at risk

Prenatal diagnosis of long-chain 3-hydroxyacyl-CoA dehydrogenase (3-HAD) deficiency was performed in a family at risk. The diagnosis of an affected fetus was carried out by enzyme assay in cultured chorionic villus cells.