Prenatal diagnosis of jumping translocation involving chromosome 22 with ultrasonographic findings

We report on the prenatal diagnosis and ultrasonographic findings of a second-trimester fetus with jumping translocation involving chromosome 22. A 28-year-old gravida 2, partus 1, Turkish woman was referred for genetic counselling and ultrasonographic examination at 18 weeks' gestation because of a high risk of trisomy 21 in triple test. Prenatal ultrasonography showed tetralogy of Fallot with a diverticular dilatation of the pulmonary artery, flattened brow, complete absence of the right upper limb, hypospadias, oligodactyly (three digits) in left hand and in both feet, and hyperechogenic abdominal foci. Amniocentesis revealed a karyotype of 46,XY[4]/46,XY,−8,+ der(8),t(8;22)(q24.3;q11.21)[2]/45, XY,−22,−8,+ der(8)t(8;22)(q24.3;q11.21)[22]/45,XY,−22,−5,+ der(5)t(5;22)(q35.3;q11.21)[44]. A C-banding and FISH study with a specific centromeric probe (D14Z1/D22Z1) for chromosome 22 was made. In our case, partial monosomy for the regions 22q11.21→22pter, 8q24.3→8qter and 5q35.3→5qter may partially explain the fetal malformations. Copyright © 2005 John Wiley & Sons, Ltd.     

Incorporating fragmentation and non‐native species into distribution models to inform fluvial fish conservation

Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial‐specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non‐native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non‐native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non‐native congeners, wherein non‐natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free‐flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats.     

Prenatal diagnosis of a lethal form of Netherton syndrome by SPINK5 mutation analysis

Netherton syndrome (NS) is a severe autosomal recessive ichthyosis with no specific treatment or prenatal diagnosis available at present. The recent identification of SPINK5, which encodes a serine protease inhibitor, as the defective gene enables DNA-based prenatal diagnosis to be carried out. Here we report the first direct molecular prenatal diagnosis of a lethal form due to a recurrent SPINK5 mutation in three consanguineous Turkish families. XmnI restriction enzyme digestion and DNA sequencing demonstrated that each deceased affected child was homozygous for mutation 153delT inherited from each parent. Analysis of fetal DNA from amniotic fluid cells in Family 1 and from a chorionic villus sampling in Family 3 showed that the fetus was heterozygous for 153delT in both cases. The pregnancies were carried to term and the newborns were unaffected. In Family 2, fetal DNA analysis from chorionic villus biopsy showed in a first pregnancy that the fetus was homozygous for 153delT. The pregnancy was terminated at 13 weeks and DNA analysis of fetal keratinocytes confirmed the prenatal prediction. In a second pregnancy in Family 2, fetal DNA analysis showed heterozygosity for 153delT, and the pregnancy was continued. Direct SPINK5 mutation analysis in families at risk for NS represents the first early, rapid and reliable method for prenatal diagnosis of this life-threatening form of ichthyosis. Copyright © 2002 John Wiley & Sons, Ltd.     

Prenatal diagnosis of mosaic tetrasomy 5p

We report the prenatal diagnosis of a fetus with tetrasomy 5p mosaicism resulting from a supernumerary isochromosome for the short arm of chromosome 5. The pregnancy was terminated and fetal autopsy revealed minor facial abnormalities (long philtrum, up-slanting palpebral fissures and a broad nasal bridge). Cultures were established from fetal skin, kidney, and pancreas for cytogenetic analysis; the i(5p) was observed only in the skin fibroblasts. To our knowledge, this is the fourth report of mosaic tetrasomy 5p and the first report of prenatal diagnosis of this abnormality. Copyright © 2001 John Wiley & Sons, Ltd.     

3,5-二甲基吡唑对尿素氮转化及NO-3-Ｎ淋溶的影响

采用室内培养和田间试验相结合的方法,探讨了新型硝化抑制剂3,5-二甲基吡唑（DMP）对尿素氮转化及玉米田硝酸盐淋溶损失的影响.结果表明,DMP对尿素水解仅起短暂的抑制作用,但可在较长时间内显著抑制土壤铵的氧化,且随DMP用量的增加,抑制效应显著增强.培养第10 d时,DMP各处理 （0.002?5、0.01 及 0.025 g/kg）的土壤NH₊₄-Ｎ累积量分别比CK提高了5.17、9.36和11.04倍,而NO^-₃-Ｎ累积量于培养第14 d时差异最大,与CK相比分别降低了33.30%、61.19%和73.72%（p<0.01）.土壤NO^-_2-Ｎ只在尿素施用前期有少量累积,但第3 d DMP各处理土壤NO^-_2-Ｎ含量降低幅度达95.77%～96.13%;土壤矿质氮总量于10 d以后,随DMP用量的增加,显著降低,而DMP1处理的土壤微生物量N在培养14～56 d期间显著提高.连续2 a的玉米田间试验原位取土测定结果表明,2004和2005年,DMP的施用使作物根系密集层以下（40～100 cm）土层的NO^-₃-Ｎ累积总量分别比CK降低了28.77%和44.70%.因此,硝化抑制剂DMP与尿素配合施用是调控氮素转化、缓解氮肥污染的有效措施.     

微生物菌粉与菌液矿化固结Zn~(2+)的研究与对比

利用碳酸盐矿化菌在底物诱导下的酶化作用,分解产生碳酸根离子,矿化固结环境(土壤水体)当中的游离重金属离子,减少其危险。文章以Zn2+溶液模拟重金属离子污染体系,研究过程中发现,生产的矿化产物主要是ZnO.5(OH)62(CO)3。分别用菌粉和菌液进行微生物矿化试验,对矿化产物进行底物分解率,SEM,XRD,矿化粒径的对比研究。从对比研究结果看,菌粉复活后,可以达到与菌液基本相同的矿化效果。而菌粉相对于菌液而言,其主要优势在于能长时间储存,产品体积小,运输起来更方便,因此,菌粉具有更广泛的应用性。     

广州市实施I/M简易瞬态工况检测方法的环境效果分析

采用简易瞬态工况法对在用车进行检测,能够更为有效地筛选高排放车辆.2007—2009年广州市轻型汽油车的简易瞬态工况法的初检数据表明,国Ⅰ排放标准实施以前(简称"国Ⅰ前")车辆和国Ⅰ及以后排放标准车辆排放超限值比例分别为20.1%和17.6%.简易瞬态工况法复检数据得到的国Ⅰ前和国Ⅰ及以后车辆经维护后能够达标的比例分别为76.0%和64.7%,且经过有效维护后超标车辆的平均排放水平有较大比例的削减.同时,采用修正的MOBILE5模型对广州市轻型汽油车排放进行模拟.结果发现,广州市2009年轻型汽油车的CO、HC和NO_x排放量分别为24.4×10⁴、3.8×10⁴和1.8×10⁴ t.如果考虑I/M制度实施及实际执行率,复检不达标车辆在全部淘汰情景下,2009年广州市轻型汽油车排放的CO、HC和NO_x分别能削减4.20×10⁴、0.58×10⁴和0.15×10⁴ t,占全部轻型汽油车的削减比例分别为17.2%、15.3%和8.2%;而在全部置换为国Ⅳ新车情景下,3种污染物分别能削减4.12×10⁴、0.57×10⁴和0.14×10⁴ t,削减比例分别为16.9%、15.0%和8.0%.国Ⅰ前及国Ⅰ车辆对CO和HC削减量的贡献达到90%左右,对NO_x削减量的贡献也在85%左右.     

博斯腾湖大湖区环境因子动态分析研究

为促进干旱区湖泊健康发展,分析了博斯腾湖大湖区湖水多年溶解氧与五日生化需氧量、高锰酸盐指数、总磷、总氮和氨氮的动态特征:1991年-2014年(2009、2012除外)水体溶解氧为6.71~9.20 mg/L,最高值与最低值分别在2005年和2006年,此与2005年水位最高,而后下降的特征一致;五日生化需氧量在0.5~6.99 mg/L变幅较大,并与溶解氧同年出现最高值,且二者符合线性回归关系y=0.213x+7.053;高锰酸盐指数波动明显;总氮和总磷则较平稳;氨氮从0.01 mg/L升至最高值0.45 mg/L.高锰酸盐指数和总氮对水质影响最大.     

Prenatal diagnosis of free sialic acid storage disorders (SASD)

Free sialic acid storage disorders, Salla disease (SD) and Infantile sialic acid storage disease (ISSD), are lysosomal storage diseases due to impaired function of a sialic acid transporter, sialin, at the lysosomal membrane. Several mutations of the sialin gene, SLC17A5, are known, leading either to the severe neonatal/infantile disease or to the milder, adult-type developmental disorder, Salla disease. Free sialic acid accumulation in lysosomes causes increased tissue concentration and consequently elevated urinary excretion. Prenatal diagnosis of SASD is possible either by determination of free sialic acid concentration or by mutation analysis of the SLC17A5 gene in fetal specimen, in chorionic villus biopsy particularly. Both techniques have been successfully applied in several cases, sialic acid assay more often in ISSD cases but mutation analysis preferentially in SD. Sialic acid assay of amniotic fluid supernatant or cultured amniotic fluid cells may give erroneous results and should not be used for prenatal diagnosis of these disorders. The present comments are mainly based on our experience of prenatal diagnosis of SD in Finnish families. A founder mutation in SLC17A5 gene, 115C-> T, represents 95% of the disease alleles in the Finnish SD patients, which provides a unique possibility to apply mutation analysis. Therefore, molecular studies have successfully been used in 17 families since the identification of the gene and the characterization of the SD mutations. Earlier, eight prenatal studies were performed by measuring the free sialic acid concentration in chorionic villus samples. Copyright © 2006 John Wiley & Sons, Ltd.