Congenital nephrosis in low-risk pregnancies

Congenital nephrosis is an autosomal recessive disorder requiring neonatal renal transplant for survival. The postnatal diagnosis rests upon the electron microscopic evaluation of the epithelial foot processes and basal membrane of the glomeruli. The prenatal diagnosis can be suspected in the presence of a positive family history with an amniotic fluid (AF) alpha-fetoprotein level greater than 5 standard deviations (SD) above the population mean accompanied by a negative AF acetylcholinesterase, absent haemoglobin F, and an unremarkable fetal sonographic examination. We reviewed our series of seven cases of congenital nephrosis fulfilling the above criteria; four cases had negative family histories, and in two cases the diagnosis of congenital nephrosis was further supported by the presence of elevated AF albumin concentrations. We conclude that (1) the prenatal diagnosis of congenital nephrosis is feasible in a low-risk population, and (2) an elevated AF albumin concentration may represent an additional marker for the diagnosis of congenital nephrosis, even though false-negative results have been reported.     

1株分离自煤矿废水的铁硫氧化细菌LY01的鉴定及其氧化特性研究

从贵州省某煤矿废水中分离出1株嗜酸性的铁硫氧化细菌菌株LY01,经过对该菌株的形态特征、理化特征检测及16S rRNA序列分析,初步鉴定菌株LY01为嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans).在无机盐培养液中菌株LY01可以从氧化Fe2+、单质硫(S0)及黄铁矿(FeS2)获得能量生长,对Fe2+的氧化速率最快,反应30 h即可将44.2 g.L-1的FeSO4.7H2O完全氧化,菌体细胞达到4.2×107个.mL-1;反应21 d可将溶液中10 g.L-1含量的S0氧化6.7%,溶液中SO24-浓度达2 001 mg.L-1,菌体细胞达到8.9×107个.mL-1;反应20 d可将溶液中30 g.L-1含量的FeS2氧化10%,溶液中SO24-浓度达4 443 mg.L-1,菌体细胞达到3.4×108个.mL-1.研究重金属离子Ni2+、Pb2+对菌株LY01氧化FeS2活性的影响,结果发现10～100 mg.L-1的Ni2+对菌株LY01氧化FeS2活性有一定的影响,而10～100 mg.L-1Pb2+对菌株LY01氧化FeS2的活性无影响.     

Prenatal diagnosis of the Hunter syndrome and the introduction of a new fluorimetric enzyme assay

Prenatal diagnosis of the Hunter syndrome (mucopolysaccharidosis type II; MPS II) is preferably achieved by the assay of iduronate-2-sulphate sulphatase (IDS) in uncultured chorionic villi (CV) as this allows early (12th week), rapid (2–3 days) and reliable results. We summarize the results of 174 prenatal analyses in the past 30 years, using various methods such as radiolabelled sulphate incorporation in amniotic fluid (AF) cells, glycosaminoglycan (GAG)-electrophoresis in AF and IDS assay in CV, CV-cells, AF and AF-cells. Twenty-seven fetuses with MPS II were diagnosed after finding clearly abnormal results in pregnancies with a male fetus; very low IDS activity has also been measured in some pregnancies with a (heterozygous) female fetus, emphasizing the need to combine enzyme assay with fetal sex determination. IDS activity has until recently been assessed by a cumbersome radioactive enzyme assay. Here we describe the use of a novel fluorigenic 4-methylumbelliferyl substrate, which allows a sensitive, rapid and convenient assay of IDS activity and reliable early prenatal diagnosis. This novel IDS assay was validated in retrospective analyses of 14 CV, CV-cell, AF and AF-cell samples from affected pregnancies in addition to prospective prenatal diagnosis in eight pregnancies at risk with one MPS II-affected fetus. Copyright © 2002 John Wiley & Sons, Ltd.     

Prenatal diagnosis of citrullinaemia: Review of a 10-year experience including recent use of DNA analysis

Prenatal diagnosis of citrullinaemia has been accomplished by three different methods to date: (1) enzyme assay of cultured fetal cells; (2) quantification of citrullirie in amniotic fluid supernatant; and (3) incorporation of [¹⁴C]citrulline into protein by cultured fetal cells. Our laboratory has used these methods to perform prenatal diagnosis for 28 fetuses over a 10-year period. More recently, DNA polymorphisms were used for prenatal diagnosis by linkage analysis. Of the 28 fetuses studied, 23 were predicted to be unaffected, four were predicted to be affected, and results were conflicting in one case where [¹⁴C]citrulline incorporation erroneously indicated an affected fetus but linkage analysis correctly predicted an unaffected fetus. Because of low levels of enzyme activity in heterozygotes and in certain amniotic fluid cell types, biochemical diagnosis of citrullinaemia is complicated by the risk of false affected results, although [¹⁴C]citrulline incorporation is relatively reliable. When informative, linkage analysis is the preferable method for cases with a 25 per cent risk. The risk of false affected results makes prenatal diagnosis for cases with less than 25 per cent risk of questionable value.     

Prenatal diagnosis of medium-chain acyl-coenzyme A dehydrogenase deficiency

A fatal case of medium-chain acyl-coenzyme A dehydrogenase deficiency is described in a patient who presented with hypoglycaemia and a gross non-ketotic dicarboxylic aciduria. Cultured skin fibroblasts released ¹⁴CO₂ from [1–¹⁴C] octanoic acid at half the normal rate. Prenatal diagnosis was undertaken in a subsequent pregnancy in which cultured amniotic fluid cells revealed a marked reduction in octanoate oxidation indicative of an affected fetus. The pregnancy was terminated and the diagnosis was confirmed by enzyme analysis of skin fibroblasts taken from the fetus. The high residual octanoate oxidation by affected fibroblasts together with the absence of any characteristic abnormality of amniotic fluid organic acids are a potential limitation to the reliability of this type of prenatal diagnosis.     

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.     

管流电氧化杀藻及其影响要素

对藻种类、电流密度、电极材料、细胞密度和流量对电化学氧化杀藻的影响进行了研究.实验结果显示,铜绿微囊藻比水华鱼腥藻对电化学氧化更为敏感,藻的种类和形状对杀藻效果存在影响.使用普通镀锌水管、铜水管和钛管作为阴极进行实验,发现阴极材料对结果影响不大,而阳极对杀藻效果影响较大,钌钛电极效果明显好于钛电极.电流密度对杀藻效果影响很大,电流密度为1mA.cm^-2时,杀藻效果不明显,当电流密度大于2.5mA.cm^-2时,杀藻效果开始非常显著.细胞密度是影响杀藻效果的重要因素,在5mA.cm^-2下,低密度(6×10⁸个/L)水样的光密度值下降明显比高密度(6×10⁹个/L)水样快.水样在反应器中的流量对结果影响不大.     

Circulating ‘trophoblast’ cells in pregnancy have maternal genetic markers

A syncytiotrophoblast-associated antigen identified by the monoclonal antibody (McAb) H315 is detectable on the surface of a low proportion of peripheral blood cells in pregnant women, raising the possibility of a new approach to prenatal diagnosis of genetic disorders. We aimed at verifying the trophoblastic origin of H315⁺ cells and their use for prenatal diagnosis of β-thalassaemia. H315 ⁺ cells were separated from the peripheral blood of pregnant women: the DNA obtained from these cells in two selected cases was shown to have genetic markers indistinguishable from those of the mother and definitely different from the fetus. Our results suggest that H315 antigen is expressed by maternal cells and that prenatal diagnosis on peripheral blood of the mother using H315 McAb is not feasible.     

Prenatal interphase FISH diagnosis of PLP1 duplication associated with Pelizaeus–Merzbacher disease

A submicroscopic genomic duplication in Xq22.2 that contains the entire proteolipid protein 1 gene (PLP1) is responsible for the majority of Pelizaeus–Merzbacher disease (PMD) patients. We previously developed an interphase FISH assay to screen for PLP1 duplications in PMD patients using peripheral blood and lymphoblastoid cell lines. This assay has been utilized as a clinical diagnostic test in our cytogenetics laboratory. To expand usage of the interphase FISH assay to prenatal diagnosis of PLP1 duplications, we examined three PMD families with PLP1 duplications utilizing aminiotic fluid samples. In two families the FISH assay revealed fetuses with PLP1 duplications, whereas the other fetus showed a normal copy number of PLP1. Haplotype analyses, as well as an additional FISH analysis using postnatal blood samples, confirmed the results of the prenatal analyses. Our study demonstrates utility of the interphase FISH assay in the prenatal diagnosis of PLP1 duplications in PMD. Copyright © 2001 John Wiley & Sons, Ltd.     

All-in-one whole exome sequencing strategy with simultaneous copy number variant,single nucleotide variant and absence-of-heterozygosity analysis in fetuses with structural ultrasound anomalies: A 1-year experience

Objective

We performed a 1-year evaluation of a novel strategy of simultaneously analyzing single nucleotide variants (SNVs), copy number variants (CNVs) and copy-number-neutral Absence-of-Heterozygosity from Whole Exome Sequencing (WES) data for prenatal diagnosis of fetuses with ultrasound (US) anomalies and a non-causative QF-PCR result.

Methods

After invasive diagnostics, whole exome parent-offspring trio-sequencing with exome-wide CNV analysis was performed in pregnancies with fetal US anomalies and a non-causative QF-PCR result (WES-CNV). On request, additional SNV-analysis, restricted to (the) requested gene panel(s) only (with the option of whole exome SNV-analysis afterward) was performed simultaneously (WES-CNV/SNV) or as rapid SNV-re-analysis, following a normal CNV analysis.

Results

In total, 415 prenatal samples were included. Following a non-causative QF-PCR result, WES-CNV analysis was initially requested for 74.3% of the chorionic villus (CV) samples and 45% of the amniotic fluid (AF) samples. In case WES-CNV analysis did not reveal a causative aberration, SNV-re-analysis was requested in 41.7% of the CV samples and 17.5% of the AF samples. All initial analyses could be finished within 2 weeks after sampling. For SNV-re-analysis during pregnancy, turn-around-times (TATs) varied between one and 8 days.

Conclusion

We show a highly efficient all-in-one WES-based strategy, with short TATs, and the option of rapid SNV-re-analysis after a normal CNV result.     

Fenton氧化深度处理石化废水厂二级出水研究

采用连续流Fenton氧化对石化废水处理厂二级出水进行了处理试验,研究了药剂投量对COD及磷处理效果的影响,同时对处理过程中有机物的变化特性进行了分析.结果表明,原水COD平均为64.8 mg·L-1,PO3-4-P平均为0.79 mg·L-1,当H2O2(30%)投加量为0.4 m L·L-1,Fe SO4·7H2O的投加量为0.8 g·L-1,PAM投加量为0.9 mg·L-1,停留时间为30 min时,COD的平均去除率为24.3%,出水COD低于50 mg·L-1,PO3-4-P平均去除率为95.5%,原水中相对分子质量小于1×103的有机物占80.4%,Fenton氧化处理后该部分比例增加至95.6%.三维荧光分析结果表明,Fenton氧化对水中蛋白类、酚类去除效果显著.GC-MS结果表明,石化二级出水中检出主要有机物约117种,氧化后检出27种,含不饱和键类有机物去除明显.Fenton氧化可用于石化二级出水的深度处理.     

The development of the fetal eye: In utero ultrasonographic measurements of the vitreous and lens

Our objective was to establish nomograms for fetal eye measurements from 12 weeks' gestation by using transvaginal and transabdominal high-resolution ultrasound techniques. A prospective cross-sectional study was performed on 450 normal singleton pregnancies between 12 and 37 weeks' gestation. Vitreous and lens circumferences were measured by transvaginal ultrasonography until 17 weeks, and by abdominal ultrasound between 18 and 37 weeks' gestation. Regression analyses were used to create nomograms, and several transformations were done to obtain linearity. Eye measurements of 12 fetuses at risk for ocular disturbances were plotted on the constructed nomograms. Linear relationships were fitted between vitreous (r²=0.79) and lens (r²=0.88) circumferences and gestational age. In addition, there was a significant correlation between these measurements and the biparietal diameter. Data of the fetuses at risk showed that disturbances in ocular growth were associated mainly with abnormal cerebral development. These normative data may be helpful in the prenatal diagnosis of suspected congenital syndromes that include, among their manifestations, ocular growth disturbances such as microphthalmos and anophthalmos.     

Management of prenatally detected trisomy 8 mosaicism

We report on ten pregnancies with trisomy 8 mosaicism. Nine cases were prenatally detected in chorionic villi (n=6), amniotic fluid (AF) cells (n=2) or fetal blood (FB) lymphocytes (n=1). Follow-up laboratory investigations showed confined placental mosaicism (CPM) or pseudomosaicism in eight cases. In one case with ultrasound abnormalities, trisomy 8 mosaicism was detected in FB cells although cultured AF cells showed normal cells only. Another case of mosaic trisomy 8 was prenatally missed; cytogenetic analysis of short-term cultured villi revealed a normal male karyotype, while postnatally, trisomy 8 mosaicism was detected in peripheral blood lymphocytes and skin fibroblasts of the affected child. These findings indicate the difficulties in the prenatal diagnosis of trisomy 8 mosaicism. When found in chorionic villi, it mostly represented CPM, while in a case of true fetal trisomy 8 mosaicism, the cytotrophoblast cells showed a normal karyotype. So, the cytotrophoblast compartment of chorionic villi is a poor indicator of the presence or absence of fetal trisomy 8 mosaicism. Follow-up investigations including amniocentesis and especially fetal blood sampling are required to come to a definite prenatal diagnosis of trisomy 8 mosaicism. Copyright © 2001 John Wiley & Sons, Ltd.     

Prenatal diagnosis of haemoglobin disorders by cordocentesis at 12 weeks' gestation

Prenatal diagnosis of haemoglobin disorders is accepted to be a useful procedure to avoid births of infants with homozygous diseases. Advances in sampling and molecular techniques, such as polymerase chain reaction (PCR) and chorionic villus sampling (CVS), have made earlier and safer first-trimester prenatal diagnosis possible. However, these procedures need previous studies of at-risk couples, which can be very time-consuming when a number of different β-thalassaemia mutations occur in the region. We describe the possibility of making a first-trimester prenatal diagnosis by cordocentesis and fetal blood analysis at the 12th week of gestation. We found no statistically significant difference (p>0.05) between β/γ values in fetuses at the 12th and 18th weeks of gestation. In seven affected fetuses aborted at the 12th week of gestation, the diagnosis was confirmed in all cases by PCR analysis. These findings suggest that early cordocentesis could be an alternative procedure to CVS and PCR analysis.     

Fetal erythroblasts from maternal blood identified with 2,3-bisphosphoglycerate (BPG) and in situ hybridization (ISH) using Y-specific probes

Different types of fetal nucleated cells can be found in maternal blood, providing the possibility of non-invasive prenatal diagnosis. For this purpose, we have studied fetal erythroblasts. We discovered that haemoglobin-containing cells treated with 2,3-bisphosphoglycerate (BPG) can be visualized by a peroxidase reaction, which at the same time visualizes an in situ hybridization (ISH) signal, specific for the X, Y or 21 chromosome. In order to prove that the BPG-positive cells were erythroid, an anti-glycophorin A (GPA) antiserum combined with a staphylococcal rosette technique was used. To enrich for erythroblasts, leukocytes were depleted from maternal blood by treatment with anti-CD45 monoclonal antibody and passage over an anti-mouse IgG-coated glass bead column. To evaluate the potential of the method for clinical use, we studied maternal blood samples from 18 women referred to us for prenatal diagnosis between 6 and 19 weeks of gestation. Erythroblasts were found in 13 out of 14 normal pregnancies. Erythroblasts with a Y-signal were found as early as 9 weeks of gestation, but at 6 weeks the Y-signal was seen in BPG-negative cells only. These cells showed an epithelioid morphology indicating that they were cytotrophoblasts. The BPG-ISH method provides a simple technique for identifying erythroblasts and simultaneously visualizing a desired probe.     

闽江口鳝鱼滩芦苇湿地沉积物甲烷产生与氧化潜力对外源物质输入的响应

研究河口湿地沉积物甲烷(CH4)产生和氧化对外源物质输入的响应,对环境保护及温室气体减排具有重要意义.本研究基于室内培养-气相色谱法,探讨了闽江河口半咸水芦苇(Phragmites australis)沼泽湿地沉积物CH4产生与氧化对不同外源物质(底物、电子受体和营养物质)输入的响应.结果表明:CH3OH(500 mg·kg-1)、C3H9N(500 mg·kg-1)和Fe2+(0~500 mg·kg-1)对CH4产生潜力起促进作用(p0.05);NO-3(0~500 mg·kg-1)、NO-2(0~500 mg·kg-1)、Fe3+(50 mg·kg-1)和NH+4(50~500 mg·kg-1)表现为抑制CH4产生潜力(p0.05);而0~50 mg·kg-1的CH3OH和C3H9N、0~500 mg·kg-1的CH3COOH、SO2-4、Mn4+、PO3-4和低剂量的NH+4(0~5 mg·kg-1)对CH4产生的影响不显著(p0.05).实验剂量内(0~500 mg·kg-1),Fe3+和Mn4+的添加可促进CH4氧化(p0.05);CH3COOH、CH3OH、C3H9N、NO-3、NO-2、SO2-4、NH+4和低剂量的PO3-4(0~50 mg·kg-1)对沉积物CH4氧化潜力均有显著的抑制作用(p0.05);而Fe2+对CH4氧化没有显著影响(p0.05).综合分析表明,CH3COOH、CH3OH、C3H9N、NO-3、NO-2、SO2-4、PO3-4、NH+4和Fe2+的输入对沉积物CH4产生和氧化的综合作用为增加CH4排放通量,而Fe3+和Mn4+输入的综合作用则与之相反.     

腐殖酸在氯离子体系中的电解氧化特性

通过小型实验对腐殖酸模拟废水进行了电解氧化处理,考察了阳极材料、氯离子初始浓度对腐殖酸电解氧化处理效果的影响,探讨了腐殖酸在电解处理过程中分子量分布的变化及电解产生的低分子量产物组成.研究结果表明,PbO2阳极的电解处理效果比 Ru-Ir/Ti阳极的处理效果好,当废水在氯离子体系中电解时.可缩小2种阳极对CODCr去除效果的差距;电解后溶液中溶解性有机物的分子量分布向小分子量方向转变;当溶液中有氯离子存在时,电解过程产生的 ClO-的间接氧化作用可有效地将大分子有机物降解为小分子有机物.腐殖酸在氯离子体系中电解生成的低分子量化合物主要有 CO2、氯仿、乙酸、苯酚、苯乙醇、2H-1,4 氯苯基双氮杂卓-2-1,1-(1,1-二甲基乙基)-萘酚、3-(3-羧基-4-羟基-5-硝基酚)-D-丙氨酸等.     

我国北方四类土壤中氨氧化古菌和氨氧化细菌的活性及对氨氧化的贡献

氨氧化古菌(ammonia-oxidizing archaea,AOA)与氨氧化细菌(ammonia-oxidizing bacteria,AOB)是目前已知的两类好氧氨氧化微生物,广泛分布于各类生态系统中.采用双氰胺(dicyandiamide;DCD)和1-辛炔(1-octyne)抑制剂的方法对我国北方湿地、草原、农田、沙漠4类生态系统的土壤中AOA和AOB的氨氧化速率(ammonia oxidation rate,AR)分别进行定量测定,剖析AOA、AOB对不同土壤中氨氧化的贡献.结果表明:在氨氮含量较高的湿地土壤((32.58±1.38)mg·kg~(-1))中氨氧化速率由AOB主导(ARAOB占AR的86.19%),而在氨氮含量较低的草原土壤((10.40±0.69)mg·kg~(-1))、农田土壤((5.09±0.25)mg·kg~(-1))中氨氧化速率则由AOA主导(ARAOA分别占AR的65.50%、62.20%).氨氮含量是影响AOA、AOB相对活性的主要限制性因素.湿地土壤中氨氧化速率最高,为3.22 mg·kg~(-1)·d~(-1)(以N计),其次是草原土壤和农田土壤,其AR分别为1.11、1.00 mg·kg~(-1)·d~(-1),沙漠土壤中未检测到氨氧化速率.对氨氧化古菌、细菌的amoA基因进行定量分析的结果表明:在氨氮含量最高的湿地土壤和最低的沙漠土壤((1.27±0.05)mg·kg~(-1))中AOA丰度高于AOB丰度,在草原、农田土壤中AOB丰度高于AOA丰度.amoA基因生物多样性分析表明,377个古菌amoA序列以85%相似度可以划分为19个独立操作单元(operational taxonomic unit,OTU),具有较高的生物多样性,其Shannon指数为1.51~1.73.直接通过氨氧化微生物amoA基因丰度来推测AOA、AOB的活性具有一定的缺陷,而依靠AOA、AOB分别的氨氧化速率能够准确地衡量其在不同生态系统中对氨氮去除的相对贡献,对于理解不同生态系统中氨氮去除过程和效应有着重要的意义.     

Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions: Effects of Ca2+ and Mg2+

Tetracyclines constitute one of the most important antibiotic families and represent a classic example of phototoxicity. The photoproducts of tetracyclines and their parent compounds have potentially adverse effects on natural ecosystem. In this study, the self-sensitized oxidation products of tetracycline (TC) and oxytetracycline (OTC) were determined and the effects of Ca²⁺ and Mg²⁺on self-sensitized degradation were investigated. The Ca²⁺ and Mg²⁺ in the natural water sample accounted for enhancement (pH 7.3) and inhibition (pH 9.0) of photodegradation of TC and OTC due to the formation of metal-ions complexes. The formation of Mg²⁺ complexes was unfavorable for the photodegradation of the tetracyclines at both pH values. In contrast, the Ca²⁺ complexes facilitated the attack of singlet oxygen (¹O₂) arising from self-sensitization at pH 7.3 and enhanced TC photodegradation. For the first time, self-sensitized oxidation products of TC and OTC were verified by quenching experiments and detected by LC/ESI-DAD-MS. The products had a nominal mass 14 Da higher than the parent drugs (designated M+14), which resulted from the ¹O₂ attack of the dimethylamino group on the C-4 atom of the tetracyclines. The presence of Ca²⁺ and Mg²⁺ also affected the generation of M+14 due to the formation of metal-ions complexes with TC and OTC. The findings suggest that the metal-ion complexation has significant impact on the self-sensitized oxidation processes and the photoproducts of tetracyclines.     

The clinical utility of microarray technologies applied to prenatal cytogenetics in the presence of a normal conventional karyotype: a review of the literature

The clinical utility of microarray technologies when used in the context of prenatal diagnosis lies in the technology's ability to detect submicroscopic copy number changes that are associated with clinically significant outcomes. We have carried out a systematic review of the literature to calculate the utility of prenatal microarrays in the presence of a normal conventional karyotype. Amongst 12 362 cases in studies that recruited cases from all prenatal ascertainment groups, 295/12 362 (2.4%) overall were reported to have copy number changes with associated clinical significance (pCNC), 201/3090 (6.5%) when ascertained with an abnormal ultrasound, 50/5108 (1.0%) when ascertained because of increased maternal age and 44/4164 (1.1%) for all other ascertainment groups (e.g. parental anxiety and abnormal serum screening result). When additional prenatal microarray studies are included in which ascertainment was restricted to fetuses with abnormal ultrasound scans, 262/3730 (7.0%) were reported to have pCNCs. © 2013 The Authors. Prenatal Diagnosis published by John Wiley & Sons Ltd.