False-positive diagnosis of trisomy 21 using fluorescence in situ hybridisation (FISH) on uncultured amniotic fluid cells

An amniocentesis was performed on a 22-week pregnancy following the detection of foetal abnormalities on ultrasound. A rapid aneuploid screen using fluorescence in situ hybridisation on uncultured amniotic fluid cells revealed 3 signals for chromosome 21, consistent with trisomy 21. In situ metaphase cultures revealed a 46,XY normal male karyotype. These discordant results may be explained by a sub-standard batch of the commercially available probe or alternatively, a very specific variation within the sample interacting with the probe. Alternative strategies are proposed in order to safeguard against inappropriate clinical action as a consequence of discordant results. Copyright © 2003 John Wiley & Sons, Ltd.     

Prenatal overgrowth and mosaic trisomy 15q25-qter including the IGF1 receptor gene

Overgrowth is rarely associated with chromosomal imbalances. Here, we report on a male foetus presenting with overgrowth and additional material on the short arm of one of the chromosome 15 in 12% of lymphocytes and 50% of amniotic cells. Parents' karyotypes were normal, indicating a de novo origin for this unbalanced rearrangement. Complementary studies using cytogenetic and FISH studies showed that this additional material resulted in a 15q25-qter trisomy and confirmed the presence of three copies of the insulin-like growth factor 1 receptor (IGF1R) gene, included in the trisomic region. Autopsy performed after termination of pregnancy revealed isolated overgrowth and absence of visceral malformations. The possible mechanisms and origins for the formation of this mosaic pure trisomy are complex. The present observation emphasises the hypothesis that the overgrowth phenotype, frequently reported in patients with trisomy including the 15q26 region, might be causally related to a dosage effect of the IGF1R gene, as well as the importance of chromosome analysis in patients with overgrowth. It also confirms that the overgrowth is of prenatal onset in those observations. Copyright © 2004 John Wiley & Sons, Ltd.     

Risk of amniocentesis in women screened positive for Down syndrome with second trimester maternal serum markers

In routine obstetrical practice, prior to offering invasive prenatal diagnosis, it is crucial to weigh the risks attendant on amniocentesis against the individual's risk of aneuploidy. We took advantage of a policy of follow-up of patients undergoing Down syndrome maternal serum screening to compare the rates of fetal loss before 24 weeks and of early premature delivery at 24–28 weeks between women who underwent amniocentesis and women who did not. A total of 54 902 patients entered the study, of whom 4039 (7.35%) were lost to follow-up and 387 were excluded because of a severe fetal abnormality. Of the 50 476 remaining patients, 3472 had an amniocentesis whereas 47 004 had not and served as controls. In the amniocentesis group, the fetal loss rate before 24 weeks was 1.12% (95% CI=1.08–1.15) and the 24–28 weeks premature delivery rate was 0.40% (95% CI=0.39–0.41) which was significantly higher than in controls (0.42% with 95% CI 0.41–0.43 and 0.24% with 95% CI 0.23–0.25, respectively). The 0.86% difference in adverse outcome rates between the amniocentesis and control groups may be attributable to amniocentesis and compares favourably with the positive predictive value of maternal serum markers (1.70%) observed in the present study. Copyright © 2002 John Wiley & Sons, Ltd.     

Resource windfalls,investment, and long-term income

We develop a simple mechanism to explain why resource windfalls are likely to lower income levels in the long run. Most mineral-producing countries, in particular, fail to maintain incentives for savings and investment after positive resource shocks. Our analysis focuses on this savings–investment transmission channel through which resource rents affect welfare, and develops an OverLapping-Generations (OLG) model with features from endogenous growth theory to study the mechanism. In this model, savings adjust downwards to income from natural resources, investments adjust to savings, and subsequently the level of overall productivity falls. Resource affluence has two counteracting effects on income. In the short term, resource wealth augments income, but in the long-term, it decreases income through a crowding-out effect on knowledge creation.     

Prenatal diagnosis of partial trisomy 12q: clinical presentations and outcome

We present a pregnant woman with a fetus prenatally diagnosed as 46, XY,der(4) t(4;12) (q35.1; q21.2). This defect resulted from the unbalanced segregation of a paternal balanced translocation, t(4;12) (q35.1; q21.2). Prenatal ultrasound revealed borderline ventriculomegaly, a thick nuchal fold, pericardial effusion, arthrogryposis, a single umbilical artery, and micropenis. Fluorescence in situ hybridization (FISH) with whole chromosome painting probe and microarray-based comparative genomic hybridization analysis further confirmed chromosomal gain of terminal 12q. The woman had her pregnancy terminated at 20 weeks of gestational age. When compared with previously reported cases, the proband had characteristics common to the phenotypes of partial trisomy 12q, including an abnormal facial appearance and multiple anomalies. Additionally, this case had previously unreported phenotypes, such as arthrogryposis, a single umbilical artery, and a micropenis. Regarding the outcome of partial trisomy 12q, the fetuses carrying trisomies distal to 12q24 have a good chance of extended postnatal survival. In contrast, the cases with trisomies involving a larger amount of 12q likely die prenatally or within a few days after birth. Copyright © 2005 John Wiley & Sons, Ltd.     

Congenital heart disease and aneuploidy

Congenital heart disease (CHD) is one of the commonest prenatal diagnoses made on routine ultrasound screening. Overall, up to 33% of CHD are associated with fetal aneuploidy. However, some specific cardiac lesions have a significantly greater association with particular chromosomal abnormalities. The majority of fetuses with CHD and aneuploidy also have extra-cardiac anomalies and are best managed by a multidisciplinary team where the management and prognosis of the cardiac defect can be discussed in the context of the baby as a whole. It is therefore important for clinicians involved in the management of fetuses with CHD to be aware of the association of aneuploidy as well as the prognosis and management of these cases, so that they can appropriately counsel the parents. In this chapter, we review the frequency and types of aneuploidy associated with the commonly diagnosed CHD and discuss their management. Copyright © 2004 John Wiley & Sons, Ltd.     

昆明市“十三五”环境保护和生态建设思路探讨

“十三五”是国家全面建成小康社会的攻坚时期,在昆明市经济社会发展迈入新常态的同时,环境保护将面临诸多挑战和重大机遇。文章梳理了昆明市的环境保护形势,提出了昆明市“十三五”环境保护与生态建设的构想。在“十三五”期间,要积极努力将昆明市环境保护的改善和提供民生环境福祉作为核心目标,重点围绕大气、水、生态、环境风险以及公众参与等方面,设计战略任务,并建立夯实法律基础,突出经济引导相融合的环境管理新模式,开创环境保护与生态建设新局面。