Diagnosis of polyhydramnios in early gestation: Indication for prenatal diagnosis?

Previously published reports have indicated that idiopathic polyhydramnios may be associated with trisomies 18 and 21 and that chromosomal analysis is indicated. Furthermore, the natural history and fetal outcome of polyhydramnios diagnosed in early gestation have not been well delineated. We identified 138 pregnancies with polyhydramnios prior to 26 weeks' gestation. Of 131 complete cases, 21 were diagnosed as severe, 18 as moderate, and 92 as mild polyhydramnios. Congenital abnormalities were noted in 18 of 21 severe cases (86 per cent). Two of the remaining three cases were twin-to-twin transfusion. Thirteen of 18 cases with moderate polyhydramnios (72 per cent) were associated with anomalies; six of the remaining cases were twin-to-twin transfusion. Sixteen of 92 cases of mild polyhydramnios (17 per cent) were associated with congenital abnormalities. In 69 of 76 cases of mild hydramnios not associated with anomalies (91 per cent), the hydramnios resolved prior to delivery. Only 2 of 16 (13 per cent) associated with anomalies resolved. In 4 of 5 cases (80 per cent) with moderate hydramnios and no anomalies, the amniotic fluid volume was normal on subsequent ultrasound. No case of moderate polyhydramnios associated with anomalies or maternal conditions nor any case of severe polyhydramnios resolved. There were seven cases of chromosomal abnormalities in this series; all were associated with sonographic findings in addition to the presence of polyhydramnios. On the basis of these data, we doubt the benefit of amniocentesis following the early diagnosis of idiopathic polyhydramnios in the absence of other ultrasound findings.     

Mild fetal cerebral ventriculomegaly as a prenatal sonographic marker for Kartagener syndrome

Primary ciliary dyskinesia (PCD), also referred to as immotile-cilia syndrome or Kartagener syndrome, is a group of genetic disorders caused by defective cilia leading to chronic sinupulmonary infection, situs inversus and reduced fertility. Some PCD patients also have cerebral ventriculomegaly or hydrocephalus. We report here two fetuses and one newborn with mild cerebral ventriculomegaly and a suspected and/or confirmed diagnosis of PCD. These cases demonstrate that mild fetal cerebral ventriculomegaly can be a prenatal sonographic marker of PCD, certainly in fetuses with situs inversus or a history of a previous sib with PCD. Copyright © 2003 John Wiley & Sons, Ltd.     

Isolated mild fetal cerebral ventriculomegaly: a retrospective analysis of 26 cases

We retrospectively studied 26 fetuses with isolated mild cerebral ventriculomegaly diagnosed between 1992 and 1998 and defined by a lateral ventricular atrial diameter of 10–15 mm without any other cerebral anomaly. Our objectives were to determine maternal risk factors, to evaluate complementary investigations, to assess developmental prognosis and to propose possible management. During pregnancy 10/26 patients had regressive ventriculomegalies, ten remained borderline at birth and six were confirmed postnatally. No maternal risk factors were identified. Prenatal investigations were carried out in 69% of cases but in only a few cases supplied any information. Postnatal examinations revealed one case of Down syndrome and one of porencephaly. Four children were lost to follow-up. In the 22 other cases, four had developmental delay. Early and unexplained mild ventriculomegaly appears to have a good prognosis. If ventriculomegaly is persistent, prenatal management should be carried out to investigate chromosomal abnormalities, viral infection, and fetal cerebral parenchymal damage. A long postnatal clinical follow-up is required. Copyright © 2001 John Wiley & Sons, Ltd.     

Apert syndrome: what prenatal radiographic findings should prompt its consideration?

Apert syndrome was diagnosed in a newborn with typical facial and digital features whose only detected prenatal abnormality had been agenesis of the corpus callosum. This prompted a review of the central nervous system findings in all cases of Apert syndrome treated at the Craniofacial Center Boston Children's Hospital between 1978 and 2004. Two of 30 patients with Apert syndrome had prenatal identification of mild dilatation of the lateral cerebral ventricles and complete agenesis of the corpus callosum (ACC) documented with both ultrasound and MRI. Both had the common S252W mutation of FGFR2. Though cranial and orbital malformations typical of Apert were eventually seen in these fetuses in the third-trimester, even in retrospect, these were not detectable at mid second-trimester, ultrasound screening for congenital malformations. Hand malformations also went undetected in the second-trimester despite extensive imaging by experienced radiologists. We conclude that prenatal ultrasonographic identification of mild ventriculomegaly or ACC should stimulate a careful search for features of Apert syndrome and prompt follow-up imaging to look for bony abnormalities that have later onset. Prenatal molecular testing for Apert mutations should be considered in cases of mild ventriculomegaly and ACC. Copyright © 2006 John Wiley & Sons, Ltd.     

Role of the second-trimester ‘genetic sonogram’ for Down syndrome screen in the era of first-trimester screening and noninvasive prenatal testing

Ultrasonography for the screening of Down syndrome was first introduced about 25 years ago. Different combinations of markers detectable at second-trimester ultrasonography have been proposed under the banner of ‘genetic sonogram’. In recent years, several developments in first-trimester screening and the recent introduction of noninvasive prenatal testing for aneuploidy screening have had important implications for the prevalence of these conditions in the second-trimester and the screening performance of a genetic sonogram. Several second-trimester sonographic markers for Down syndrome have been reported; meta-analysis has shown that the most powerful predictors are mild ventriculomegaly, increased nuchal fold, hyperechoic bowel, and absent or hypoplastic nasal bone. Whereas use of individual markers should be discouraged and scoring systems of multiple markers are now obsolete, use of combined likelihood ratio and logistic regression analysis formulae provides better accuracy. However, there is significant heterogeneity in results among studies. Despite such limitations, the genetic sonogram will continue to have a place in prenatal screening, particularly in twin and higher-order multiple pregnancies, in countries with limited access to the most recent genetic screening tests, in cases with borderline results at maternal serum screening tests, and as noninvasive supplementary test for high-risk women reluctant to undergo invasive diagnostic testing. © 2014 John Wiley & Sons, Ltd.     

Fetal renal artery flow velocity waveforms in the presence of congenital renal tract anomalies

Colour Doppler flow mapping of the renal arteries and subsequent pulsed Doppler measurement of impedance to flow in these vessels were attempted in 33 fetuses with postnatally confirmed renal pathology. The majority presented with unilateral or bilateral hydronephro-sis (n = 21) and bilateral renal agenesis (n = 8). Renal artery blood flow could be visualized in all, except for the eight cases of bilateral renal agenesis. Bilateral flow velocity recordings were collected in six out of 12 cases of bilateral hydronephrosis and in five out of nine cases of unilateral hydronephrosis. The pulsatility index (PI), as a measure of downstream impedance, was in the normal range in 16 out of 18 kidneys (88 per cent) in bilateral hydronephrosis and in 12 out of 14 kidneys (85 per cent) in unilateral hydronephrosis. The PI was significantly higher in severe hydronephrosis compared with mild hydronephrosis. In four cases of unilateral multicystic kidney, the PI was always higher on the affected side. Colour Doppler flow mapping and pulsed Doppler evaluation may be helpful in our understanding of renal vascularization in renal pathology and in confirming the diagnosis of renal agenesis.     

Prenatal evaluation of fetal renal function based on serum beta2-microglobulin assessment

The relationship between fetal renal function (FRF) and fetal serum beta₂-microglobulin (B2MG) was investigated by comparing its value in 112 unaffected fetuses with that of 23 fetuses presenting with urinary tract malformations (UTM). Fetal serum level of B2MG was totally unrelated to gestational age; its value increased in cases of severe impairment of FRF but was similar to controls in all mild uropathies (p<0.05). Evaluating serum B2MG could be beneficial in fetuses with severe renal damage, but is of no use in unilateral UTM since only the global FRF is tested and not the function of each single kidney. Copyright © 2001 John Wiley & Sons, Ltd.     

Intrafamilial variability in Fraser syndrome

Fraser syndrome (OMIM 219000) is a rare, autosomal recessive disorder characterized by cryptophthalmos, cutanaeous syndactyly, malformations of the larynx and genitourinary tract, craniofacial dysmorphism, orofacial clefting, mental retardation and musculoskeletal anomalies. There is marked interfamilial clinical heterogeneity. However, there is strong phenotypic similarity and concordance of the degree of severity of the disease within a family. We report a family with two cases of Fraser syndrome with marked clinical heterogeneity. One case had lethal phenotype with bilateral renal agenesis, while the other had mild phenotype with normal kidneys. It has not been reported before and highlights the importance of careful screening of pregnancies in families with Fraser syndrome. Copyright © 2007 John Wiley & Sons, Ltd.     

Prenatal diagnosis and prenatal imaging features of fetal monosomy 1p36

Deletion of the distal end of the short arm of chromosome 1 (1p36) is thought to be a common terminal chromosomal deletion. However, few cases prospectively diagnosed prenatally have been reported. In this case, prenatal ultrasound at 21 weeks of gestation noted the fetus to have mild ventriculomegaly (Vhanterior = 11 mm and Vhposterior = 12 mm) and increased nuchal edema (6 mm). Maternal serum α-fetoprotein was normal unlike in a majority of previously described cases. The prenatal ultrasound features were further clarified with fetal MRI. Chromosome analysis following amniocentesis demonstrated a 1p36 deletion, which was confirmed by fluorescence in situ hybridization (FISH). The syndrome associated with 1p36 deletion is well described in infants and is characterized by typical facial features (prominent forehead, straight eyebrows. deep-set eyes, flat nasal bridge and a pointed chin). Other associated features are neurodevelopmental delay, seizures, cardiomyopathy and neurosensory hearing impairment. This case supplements our knowledge of the prenatal features of 1p36. Identification of this deletion by direct chromosomal analysis can be technically difficult and vigilance is required to improve diagnosis. FISH analysis is an important diagnostic adjunct where the diagnosis is suspected following classical G-banding techniques. However, in this chromosomal anomaly there remain few characteristic prenatal signs that are readily diagnosed with prenatal imaging. Copyright © 2007 John Wiley & Sons, Ltd.     

雾霾重污染期间北京居民对高浓度PM2.5持续暴露的健康风险及其损害价值评估

开展短期内高浓度空气污染造成的人体健康风险评价以及健康经济损失研究,对推进城市大气污染防控,保证人民群众的健康水平具有重要的科学价值和实际意义.研究选择2013年1月发生的北京市雾霾重污染事件,采用泊松回归模型评价全市居民对10~15日高浓度PM2.5暴露的急性健康损害风险,并采用环境价值评估方法估算人群健康损害的经济损失.结果表明,短期高浓度PM2.5污染对人群健康风险较高,约造成早逝201例,呼吸系统疾病住院1 056例,心血管疾病住院545例,儿科门诊7 094例,内科门诊16 881例,急性支气管炎10 132例,哮喘7 643例.相关健康经济损失高达4.89亿元(95%CI:2.04~7.49),其中早逝与急性支气管炎、哮喘三者占总损失的90%以上.建议应针对不同人群不同健康终点的健康风险进行健康预警并开展及早医学干预,以降低类似空气重污染事件给居民健康带来的风险和损失.     

温和预氧化提高后续生物修复石油污染土壤

为得到一种能促进后期生物阶段高效降解石油烃(TPH)的温和Fenton预氧化方式,本文考察了不同Fenton预氧化过程中羟基自由基(·OH)特征、后续生物修复过程中营养消耗、土著菌活性(CO_2)以及TPH去除量的差异,结果表明,温和Fenton预氧化组(·OH存在时间:73 h;双氧水浓度:225 mmol·L~(-1))中·OH存在时间短H_2O_2用量少,残余细菌活性高,后续对石油的生物降解率高,不加菌就能够达到与加菌相同的修复效果(TPH去除率38%左右).且在不加菌的条件下,后期生物阶段TPH去除率,温和预氧化组(38%)要高于普通预氧化组(15. 32%～33. 15%).进一步分析各链烃的去除效果,发现在后续生物修复阶段,温和预氧化组能减少对链烃组分(C17～C21)的抑制;而对比各组的土著菌活性,发现温和预氧化可以适当刺激土著微生物生长并提高其活性,这些因素均有利于TPH的去除.温和预氧化在后期生物修复阶段对TPH的去除不加菌就能够达到与加菌相同的处理效果,是一种低成本可行的修复方式.     

Statistical regression modeling for energy consumption in wastewater treatment

Wastewater treatment is one of critical issues faced by water utilities, and receives more and more attentions recently. The energy consumption modeling in biochemical wastewater treatment was investigated in the study via a general and robust approach based on Bayesian semi-parametric quantile regression. The dataset was derived from a municipal wastewater treatment plant, where the energy consumption of unit chemical oxygen demand (COD) reduction was the response variable of interest. Via the proposed approach, the comprehensive regression pictures of the energy consumption and truly influencing factors, i.e., the regression relationships at lower, median and higher energy consumption levels were characterized respectively. Meanwhile, the proposals for energy saving in different cases were also facilitated specifically. First, the lower level of energy consumption was closely associated with the temperature of influent wastewater, and the chroma-rich wastewater also showed helpful in the execution of energy saving. Second, at median energy consumption level, the COD-rich wastewater played a determinative role in the reduction of energy consumption, while the higher quality of treated water led to slightly energy intensive. Third, the higher level of energy consumption was most likely to be attributed to the relatively high temperature of wastewater and total nitrogen (TN)-rich wastewater, and both of the factors were preferably to be avoided to alleviate the burden of energy consumption. The study provided an efficient approach to controlling the energy consumption of wastewater treatment in the perspective of statistical regression modeling, and offered valuable suggestions for the future energy saving.     

透明箱法监测稻田生态系统CO2通量的研究

采用透明箱法对稻田生态系统CO₂通量进行了田间定位观测,并对透明箱内CO₂浓度的变化规律及拟合方法进行了探讨.结果表明,在水稻生长旺盛期的晴天(白天),箱内CO₂浓度随测定时间呈非线性变化,因此用常规的线性拟合法(LR)计算的CO₂净吸收通量明显低于指数一级动力学拟合法(ER).在水稻生长旺盛期的阴天、成熟期以及夜间,箱内CO₂浓度随测定时间表现为线性变化,LR法与ER法的CO₂净吸收通量计算结果无显著差异.在水稻生长期间,基于LR法的稻田生态系统碳累积吸收量结果明显低于ER法,而后者与常用方法(植物净固定碳量减去土壤异氧呼吸排放碳量)的计算结果比较接近.证实了当植被同化速率较强时,采用ER法对透明箱内CO₂浓度随时间的变化进行拟合并计算CO₂净吸收通量较为适宜.同时表明采用透明箱法观测农田生态系统CO₂通量是可行的.     

Presentation of ventriculomegaly at 11–14 weeks of gestation: An analysis of longitudinal data

Objectives

The aim of this study was to examine the value of the sonographic measurements of the choroid plexus and the lateral ventricles at 11–14 gestational weeks in fetuses that had the diagnosis of second-trimester ventriculomegaly (VM) as a clinical reference.

Methods

The standard axial plane used for biparietal diameter measurement from 2D stored images in the first trimester was used to calculate the ratio between the choroid plexus and lateral ventricle diameter (PDVDR), the choroid plexus and lateral ventricle length (PLVLR) and the choroid plexus and lateral ventricle area (PAVAR) in 100 normal and 15 fetuses diagnosed with second-trimester VM.

Results

In fetuses with VM, the measurements of PDVDR, PLVLR and PAVAR were all significantly smaller compared to normal fetuses (p = < 0.001, <0.001, <0.01). Four out of seven cases with mild VM had measurements below the 5th percentile (57%). 75% of cases with moderate or severe VM had at least one measurement below the 5th percentile.

Conclusions

Since the axial plane of the fetal head is obtained in all first-trimester routine screenings, the measurements of PDVDR, PLVLR and PAVAR could easily be integrated into routine examinations for an early detection of VM.     

Fetal cerebral hemorrhage due to X-linked GATA1 gene mutation

We report a multiplex family with a GATA1 gene mutation responsible for a massive fetal cerebral hemorrhage occurring at 36 weeks. Two other stillbirth cousins presented with fetal hydrops and congenital hemochromatosis' phenotype at 37 and 12 weeks of gestation. Molecular screening revealed the presence of a c.613G>A pathogenic allelic variation in exon 4 of GATA1 gene in the 3 male siblings and their carrier mothers. The diagnosis of a GATA1 gene mutation may be suspected in cases of male fetuses with intracerebral bleeding, particularly if a history of prior fetal loss(es) and mild maternal thrombocytopenia are also present.     

Agenesis of the corpus callosum: What to tell expecting parents?

Agenesis of the corpus callosum (ACC) is one of the most common brain malformations, with an incidence estimated to range from 0.5 to 70 in 10,000 among the general population. Prenatal diagnosis is made via ultrasound; however, fetal MRI is useful to confirm or exclude the presence of associated cerebral abnormalities–mostly cortical malformations–that may affect postnatal prognosis. When no additional central nervous system (CNS) or extra CNS anomalies are identified and no genetic cause is found, an isolated ACC is diagnosed. Overall, in cases of ACC, an underlying genetic cause can be identified in up to 12.5% with chromosomal microarray (CMA) and up to 47% with whole exome sequencing (WES). In cases where ACC is the only anomaly detected, the yield of WES is 30%. Postnatal outcomes are variable and depend on whether the condition is isolated or not. In truly isolated ACC, outcomes range from normal in 65% of cases through mild to severe neurodevelopmental impairments in 35% of cases. An interdisciplinary team of medical experts is key in guiding parents toward informed decision-making in pregnancies complicated by ACC. Considering current and expected advancements in genetic testing and imaging technologies in upcoming years, we herein summarize current recommendations for the management and prenatal counseling of expecting parents of fetuses with ACC. Our review pertains primarily to expecting parents of fetuses with complete ACC.     

Evaluation of the use of Sr2+ in alginate immobilization of cells

In recent years the method of immobilization of living cells in Ca-alginate beads has gained a wide range of applications. In all cases high chemical stability of the immobilization material and mild conditions for the cells are prerequisites. However, in long-term experiments that may last for several days Ca-alginate may dissolve due to an exchange of Ca²⁺ with Na⁺, forming fluid Na-alginate. As well as Ca-alginate, the more chemically stable Sr-alginate and Ba-alginate are materials that have been used for the immobilization of living cells. In this study, the effects of Ca²⁺, Sr²⁺ and Ba²⁺ on growth, viability and intracellular free calcium concentration in a human leukemic T cell line (Jurkat) were investigated. The findings in this study, and the fact that Sr-alginate has a considerably higher chemical stability than Ca-alginate, led to the conclusion that Sr-alginate is a more suitable material for use in the entrapment of living cells in long-term studies.     

Fetal intestinal loop dilatation: Follow-up and outcome of a series of 133 consecutive cases (the DILDIG study)

Objectives

To define the prognostic markers of fetal dilated bowel loops.

Methods

National non-interventional study of 133 consecutive prenatal observations of dilated loops including ultrasound examinations, complementary laboratory tests, magnetic resonance imaging (MRI), outcomes, and postnatal diagnosis.

Results

One hundred twenty seven cases were classified according to outcome: Group 1, very severe (n = 43), Group 2, children needing specific care (n = 39), and Group 3, healthy children (n = 45). Prenatal ultrasound scan suggested duodenal obstruction in 30 cases, small bowel obstruction in 81, colonic obstruction in 11, and diffuse dilatation in 5. Diameter of dilated loops did not significantly differ between the groups. A poor prognosis was significantly associated with duodenal obstruction, genetic anomalies (53% vs. 21.8%), including aneuploidies or CFTR gene mutations and abnormal amniotic fluid biochemistry (86.4% vs. 38.7%). A good prognosis was associated with regression of dilatation and normal MRI.

Conclusion

In this study, postnatal outcomes for fetuses with intestinal dilatation were best predicted by assessing the level of obstruction with prenatal ultrasound and MRI, determining the presence of associated malformations, amniotic fluid biochemical and genetic testing, and monitoring for regression of bowel dilatation. These results should help inform future guidelines on the prenatal and neonatal management of congenital intestinal obstruction.     

福州市不同功能区土壤中多环芳烃的含量及其源解析

对福州市不同土地利用类型下5种功能区(加油站、工业区、文教区、公园和居民区)的50个土壤样品中多环芳烃(PAHs)含量进行了分析,并对土壤中PAHs的污染程度进行了评价,同时应用因子分析/多元线性回归方法对不同功能区土壤中PAHs的来源进行了解析.结果表明,福州市表层土壤中PAHs总含量的平均值为595.9μg/kg,在国内外处于中等含量水平,为轻度污染.土壤中PAHs来源以化石燃料的燃烧源为主,煤的燃烧占53%,石油燃烧占47%.不同功能区土壤都存在一定程度的PAHs污染,15种PAHs总量的大小顺序为加油站>工业区>居民区>文教区>公园,不同功能区土壤中PAHs的来源虽然有所差异,但都以化石燃料燃烧为主要来源.     

香港大气能见度与污染物长期变化的特征和相互关系

利用香港天文台40年(1968~2007年)的能见度数据,中西区空气监测站24年(1984~2007年)的空气质量数据,采用多元回归法,分析了香港地区大气环境状况与大气污染物变化的关系.结果表明,香港地区1968~2007年间低能见度时数百分比平均每10年上升3.1%,其中,其上升趋势在1968~1989年较为平缓(平均0.7%/10a),20世纪90年代后(1990~2007年)则较为明显(平均7.3%/10a),且与地面臭氧浓度呈同步上升趋势.1993年前,低能见度时数百分比与NO2和NOx相关性显著,1993年后,与其相关性显著的污染物则是O3、SO2和NO2.这说明香港地区能见度的恶化在1993年前与光化学烟雾有关,但在1993年后则同时受光化学烟雾和与硫酸盐粒子有关的气溶胶烟雾的共同影响.