First-trimester prenatal diagnosis of homozygous (14;21) translocation in a fetus with 44 chromosomes

A (14;21) homozygous Robertsonian translocation was detected by first-trimester prenatal diagnosis. The related parents were heterozygous for the same translocation. At birth the baby was physically normal and had a normal psychomotor development. Together with a few previous observations in living homozygotes for (13;14) translocations, this case corroborates the idea that these subjects with 44 chromosomes are healthy without dysmorphic features.     

Prenatal diagnosis of a homologous Robertsonian translocation involving chromosome 15

We report the prenatal diagnosis of a fetus with a de novo Robertsonian translocation: 45,XY,der(15;15)(q10;q10). Although Robertsonian translocations are common chromosomal rearrangements, those involving homologous chromosomes are infrequent. Since chromosome 15 is imprinted, uniparental disomy (UPD) is a concern when chromosomal rearrangements involving chromosome 15 are identified. In the present case, UPD studies showed normal biparental inheritance. In contrast to the fact that most homologous acrocentric rearrangements are isochromosomes, these results indicate postzygotic formation of a Robertsonian translocation between biparentally inherited chromosomes 15. Copyright © 2001 John Wiley & Sons, Ltd.     

Fetal translocation between chromosomes 2, 18, and 21 resolved by fish

An apparently balanced t(2q;21q) translocation was discovered in fetal blood and amniocytes of a 22-week fetus, monitored because of ultrasonographic evidence of a heart disease. FISH (fluorescence in situ hybridization) analysis disclosed a complex translocation between chromosomes 2q, 18q, and 21q, which was inherited from the healthy mother. This observation corroborates the usefulness of molecular cytogenetic techniques in raising the quality of prenatal diagnosis and detecting subtle rearrangements not resolved by standard cytogenetics.     

Confirmation of a balanced chromosomal translocation using molecular techniques

Investigation of a couple, who had produced three babies with cri du chat syndrome, showed initially that the mother had an apparent deletion of chromosome 5. It seemed likely that she had a balanced chromosomal translocation but it proved impossible to detect the second chromosome involved using routine cytogenetic methods. Molecular techniques using quantitative hybridization dosage studies were performed and these showed that the mother had a double dose of DNA in the suspected delected area of chromosome 5. Further studies, using in situ hybridization techniques, revealed that the missing segment of chromosome 5 had translocated onto the short arms of a C group chromosome and further analysis of prometaphase chromosomes showed the presence of a balanced translocation, 46,XY, t(5;9)(5qter → 5p14.1::9p22 → 9pter;9qter → p22::5p14.1 5pter). As a result of these findings, it was possible to offer prenatal diagnosis to the patient in furture pregnancies, by detecting the presence of a balanced or unbalanced translocation in the fetus using molecular and cytogenetic techniques.     

Uniparental disomy in fetuses diagnosed with balanced Robertsonian translocations: risk estimate

Forty-two fetuses with non-homologous Robertsonian translocations were analyzed for uniparental disomy (UPD). One fetus with a de novo translocation t(13q;14q) had maternal isodisomy of chromosome 14. In a summary of the published data (including the present study), 315 cases were analyzed for UPD after prenatal diagnosis of balanced Robertsonian translocations, of these two fetuses had UPD, giving a risk estimate of 0.65% (CI 0.2–2.3). This risk justifies the recommendation of UPD analysis in fetuses diagnosed prenatally with Robertsonian translocations, with the emphasis on the chromosomes known to contain imprinted genes, such as 14 and 15. We also discuss the possibility of UPD in offspring of Robertsonian translocation carriers with normal karyotype. Based on the risk for UPD in fetuses with Robertsonian translocation we suggest to test these fetuses for UPD and to do so on amniocytes rather than chorionic villi when the risk for unbalanced karyotype is ∼1%, comparable to the risk for UPD. Copyright © 2002 John Wiley & Sons, Ltd.     

Trisomy 15 mosaicism owing to familial reciprocal translocation t(1;15): implication for prenatal diagnosis

We describe a 4-year-old female child with severe global mental retardation, myoclonic epilepsy, proximal hypotonia and dysmorphisms, whose prenatal diagnosis following amniocentesis revealed a constitutional female karyotype carrying a t(1;15)(q10;p11) familial reciprocal translocation. Post-natal high-resolution karyotype, Fluorescence in situ hybridization (FISH) screening for subtelomeric rearrangements, VNTR search for UPD15 in the blood and fibroblast, and WCP1 and 15 in the mother, failed to provide an explanation for the complex clinical phenotype of the proband. Since the pachytene configuration of the translocated chromosomes defines a high probability of 3:1 segregation, an extensive workup was undertaken to look for a possibly cryptic mosaicism. Four percent of the cells with trisomy 15 was found in the peripheral blood lymphocytes examined by classical cytogenetic technique and interphase FISH analysis. The clinical features associated with cryptic trisomy 15 mosaicism and the problems concerning prenatal diagnosis and genetic counselling for carriers of translocations at high risk of 3:1 segregation are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

Human parvovirus B19 infection and unbalanced translocation in a case of hydrops fetalis

In a case of hydrops fetalis, serological examination showed a recent maternal human parvovirus B19 infection. Amniocentesis revealed a unique unbalanced translocation between chromosomes 3 and 11 of the fetus. The mother proved to have a balanced reciprocal translocation between chromosomes 3 and 11. A grossly macerated hydropic male fetus was delivered with a flat nose and low implanted deformed ears. Histopathological examination revealed nuclear inclusion bodies in fetal erythroid cells, confirming human parvovirus B19 infection. Parvovirus B19 DNA was demonstrated by in situ hybridization in the nuclei of heart muscle cells. Our finding of two different disorders in one case illustrates the importance of a complete evaluation of every case of hydrops fetalis, especially concerning counselling on the outcome of future pregnancies. The human parvovirus B19 infection will not recur due to the acquired immunity of the mother, whereas the balanced reciprocal translocation will endanger future pregnancies.     

Bioaccumulation and translocation of cadmium in cole （Brassica campestris L.） and celery （Apium graveolens） grown in the polluted oasis soil, Northwest of China

A pot experiment was conducted to study the bioaccumulation and translocation of cadmium (Cd) in cole (Brassica campestris L.) and celery (Apium graveolens) grown in the Cd-polluted oasis soil, Northwest of China. The results showed that Cd in the unpolluted oasis soil was mainly bound to carbonate fraction (F2) and Fe-Mn oxide fraction (F3). However, marked change of Cd fractions was observed with increasing soil Cd concentrations, in which the concentration of Cd in F1 (exchangeable fraction), F2 and F3 increased significantly (p < 0.001 for F1, F2 and F3). The growth of cole and celery could be facilitated by low concentrations of Cd, but inhibited by high concentrations. The correlation analysis between the fraction distribution coefficient of Cd in the soil and Cd concentration accumulated in the two vegetables showed that Cd in F1 in the soil made the greatest contribution on the accumulation of Cd in the two vegetables. The high bio-concentration factor and the translocation factor of Cd in both cole and celery were observed, and Cd had higher accumulation in the edible parts of the two vegetables. Therefore, both cole and celery grown in Cd-polluted oasis soil have higher risk to human health. And the two vegetables are not suitable to be cultivated as vegetables consumed by human in the Cd-polluted oasis soil.     

Nuchal translucency thickness and outcome in chromosome translocation diagnosed in the first trimester

In order to determine the significance of nuchal translucency thickness on the subsequent natural history of first-trimester fetuses with a chromosome translocation, seven consecutive cases diagnosed between 11 and 13 weeks of gestation were reviewed. Nuchal translucency measurements were successfully obtained before chorionic villus sampling (CVS) in all cases. Three fetuses had an unbalanced translocation and all were associated with increased nuchal translucency and multiple anomalies at the detailed second-trimester scan. There were no survivors in this group. The remaining four fetuses had a balanced translocation; all had normal nuchal translucency thickness and no structural anomalies were detected in the second trimester. Three of these fetuses were born at ≥35 weeks of gestation and were phenotypically normal. However, an unexpected single fetal demise occurred in a dichorionic twin pregnancy at 28 weeks of gestation. It is concluded that nuchal translucency measurements provide important prognostic information on pregnancy outcome in first-trimester fetuses with a chromosome translocation. In parents with a known balanced translocation, the detection of increased nuchal translucency at 11–14 weeks of gestation is associated with unbalanced translocations, structural anomalies and poor pregnancy outcome. Copyright © 2001 John Wiley & Sons, Ltd.     

Characterization of marker chromosomes by microdissection and fluorescence in situ hybridization

We characterized by microdissection and fluorescence in situ hybridization (FISH) two marker chromosomes: (1) a de novo, acrocentric marker chromosome detected in 88 per cent of the amniotic fluid cells of one of two physically and developmentally normal twins; and (2) a metacentric marker chromosome present in a phenotypically normal female. Analysis of FISH probes developed from the marker chromosomes indicated that the marker chromosomes in cases 1 and 2 were del(14)(q11) and a derivative chromosome from a Robertsonian translocation, respectively. Microdissection in combination with FISH may prove to be a valuable technique in determining the chromosomal origin of de novo marker chromosomes and unbalanced structural rearrangements detected during prenatal diagnosis.     

单一与复合胁迫下油菜对镉、铅的吸收效应

以干旱区绿洲灰漠土为供试土壤,油菜(Brassica campestris L.)为供试植物,通过盆栽试验研究了Cd/Pb单一和复合胁迫下其在油菜体内的吸收和富集特征,并解析了油菜条件下Cd、Pb的交互作用.结果表明,Cd/Pb单一和复合胁迫下油菜体内Cd、Pb的含量均随着其胁迫浓度的增大而增大,但复合胁迫下油菜对Cd、Pb的吸收互为拮抗作用(Cd最大胁迫浓度<7mg.kg-1,Pb最大胁迫浓度<1 500 mg.kg-1);Cd单一胁迫下油菜对其富集能力和其在油菜体内的迁移能力均随着其胁迫浓度的增加呈现先增大后减小的趋势,Pb单一胁迫下油菜对其富集能力和其在油菜体内的迁移能力则均随着其胁迫浓度的增加而持续减小;复合胁迫降低了油菜对Cd、Pb的富集能力和Pb在油菜体内的迁移能力,但提高了Cd在油菜体内的迁移能力;油菜对Cd的吸收能力和其在油菜体内的迁移能力均远远大于Pb;油菜对重金属Cd、Pb的吸收和迁移模式均符合二次方程.     

蒽在黑麦草体内的代谢作用

以黑麦草(Lolium multiflorum Lam.)为供试植物,采用水培试验方法,研究了植物对蒽的代谢作用,并分析了其代谢产物.结果表明,经蒽培养液处理96h并转入无蒽培养液培养后0~16d,黑麦草体内蒽的含量由0.760mg/kg降为0.147mg/kg,减少80.6%,主要为植物所代谢;根部是代谢蒽的主要部位;蒽的一级代谢产物为蒽醌和蒽酮,0~16d,蒽酮在黑麦草体内总体上呈积累态势,而蒽醌则会被进一步代谢,蒽醌和蒽酮可以由根系向培养液中释放,也可由根向茎叶传输;黑麦草对蒽酮和蒽醌的传输系数(TF)分别为0.796~1.285和0.239~0.653,蒽酮更易在黑麦草体内传输.     

Prenatal diagnosis of a double heterozygote for two reciprocal translocations of familial origin

Two balanced reciprocal translocations were found in an amniotic fluid cell culture undertaken because of maternal age. One translocation had been inherited from each parent. Both translocations were traced through three generations of each family. The importance of banding techniques in diagnostic cytogenetics is stressed.     

Uptake, translocation, and debromination of polybrominated diphenyl ethers in maize

Uptake, translocation and debromination of three polybrominated diphenyl ethers (PBDEs), BDE-28, -47 and -99, in maize were studied in a hydroponic experiment. Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability. PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants. Furthermore, PBDE concentrations decreased from roots to stems and then to leaves, and a very clear decreasing gradient was found in segments upwards along the stem. These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize. More highly brominated PBDEs were translocated with more difficulty. Radial translocation of PBDEs from nodes to sheath inside maize was also observed. Both acropetal and radial translocations were enhanced at higher transpiration rates, suggesting that PBDE transport was probably driven by the transpiration stream. Debromination of PBDEs occurred in all parts of the maize, and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences. This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants, elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.     

Peri- and paracentric inversions in chromosome 12: Prenatal diagnosis and family study

Three different types of chromosome 12 inversion were seen in 15 individuals out of 44 individuals examined in one 8 generation family. Type 1: a pericentric inversion inv(12) (p112; q131) was found in 7 individuals and twice at prenatal diagnosis. Type 2: a paracentric inversion inv(12) (p123; p131) was seen in two individuals. Two individuals carried both inversion chromosomes, namely type 1 and type 2. The two inversion chromosomes were transmitted from each of the parents. Type 3: a double pericentric and paracentric inversion (type 3) inv(12) (p123; p131) (p112; q131) was observed in the daughter of one of the carriers of type 1 and 2 inversions and again at prenatal diagnosis in her son. The double inversion most likely arose through crossing-over in between the two inversion loops. A balanced translocation t(7; 13) and the inversion type 1 was observed in one individual, who transmitted the translocation only to an offspring. The frequency of inversions in amniotic fluid cells observed in our laboratory was 1·9 per cent. The clinical implications of these findings are discussed.     

土壤中十溴二苯乙烷(DBDPE)的植物吸收传输特征及微观机制研究

采用温室土培实验,研究了土壤中新型溴代阻燃剂十溴二苯乙烷（DBDPE）在不同种属植物中的吸收和传输特征,以及植物脂的影响作用;进一步应用计算模拟的手段解析了植物载脂蛋白与DBDPE的分子间相互作用,以阐明DBDPE的植物吸收传输的微观机制.结果表明,在玉米、小麦和黄瓜3种植物的根和地上部均检测到了DBDPE,根中DBDPE的含量高出地上部1~2个数量级.植物中累积的DBDPE量随时间的变化存在明显的生长稀释效应（p<0.05）.DBDPE的根吸收和茎向传输表现出植物种属间的显著差异（p<0.05）,根富集因子（RCF）顺序为黄瓜（0.30~0.57） > 小麦（0.10~0.39） > 玉米（0.03~0.26）,而传输系数（TF）为小麦（0.17~0.20） > 玉米（0.16~0.19） > 黄瓜（0.04~0.07）.DBDPE的根吸收量及RCF值与植物根脂含量成显著正相关关系（r=0.94,p<0.01;r=0.98,p<0.01）;其地上部累积量及TF值与植物地上部脂含量显著正相关（r=0.77,p<0.05;r=0.94,p<0.05）,但与植物根脂含量呈显著负相关关系（r=-0.74,p<0.05;r=-0.76,p<0.05）,说明脂是控制植物吸收和传输DBDPE的重要组分.分子对接的结果显示,DBDPE能键合进入3种植物载脂蛋白的活性区域并与载脂蛋白特异性的活性位点作用,且DBDPE与载脂蛋白的结合方式及结合能力存在植物种属的显著差异,两者的结合强弱与根吸收DBDPE能力的顺序一致,印证了实验结果.本研究有助于理解植物中DBDPE的吸收传输特征及机制,可为深入认识DBDPE的陆生生态环境行为提供重要依据.     

Prenatal diagnosis of a de novo complex chromosomal rearrangement involving four chromosomes

A complex chromosome rearrangement, apparently a balanced translocation involving chromosomes 4,6, 15 and 16, was found in cultured cells of amniotic fluid from a 32–year-old primigravida who requested amniocentesis for prenatal diagnosis because of a family history of mental retardation. Chromosome analysis of peripheral blood from both parents were normal. The couple was counselled for the prenatal diagnosis of this de novo complex translocation and, subsequently, elected to terminate the pregnancy. Post-mortem examination revealed a 23–week fetus with intrauterine growth retardation. The identical chromosome rearrangement was subsequently confirmed in cultured fibroblasts from skin and cord obtained from the abortus. To our knowledge, this is the first report where routine prenatal diagnosis revealed a fetus with a balanced complex chromosomal rearrangement involving four chromosomes of de novo origin.     

组配改良剂对土壤-蔬菜系统铅镉转运调控的场地研究

以组配改良剂LS(石灰石∶海泡石=2∶1)为试验材料,通过对湘南某矿区附近铅镉复合污染旱地土壤进行现场改良钝化,研究施加不同量的LS(0、2、4、8 g·kg-1)对茄子和苋菜植株吸收累积Pb和Cd的影响以及对Pb和Cd在2种蔬菜植株各部位间转运的调控.结果表明:1施加LS能够显著提高土壤p H,降低土壤中交换态Pb和Cd的含量.2施加LS能显著降低2种蔬菜植株各部位中Pb和Cd的含量.LS施加量为2~8 g·kg-1时,茄子果实中Pb和Cd的含量分别降低44.7%~78.6%和36.0%~78.7%;苋菜植株茎叶中Pb和Cd的含量分别降低45.8%~59.1%和40.0%~87.2%.3LS的施加降低了2种蔬菜植株各部位间Pb和Cd的转运系数.2种蔬菜植株在根-茎-果实间或根-茎叶间转运Cd的能力大于Pb,且施加LS各处理下,同种蔬菜相同部位对Pb和Cd的转运能力大小关系保持不变.     

厌氧环境下美人蕉根表铁膜对重金属积累转运的影响

根表铁膜作为污染物进入植物体内的门户,对植物修复重金属污染底泥起着重要作用.有机物降解消耗DO导致的底泥厌氧环境会显著影响根表铁膜的形成,并改变重金属的生物地球化学特征,从而影响重金属污染底泥的植物修复效果.为了探讨底泥厌氧环境中植物根表铁膜对重金属积累和转运的影响,采用向底泥中投加蔗糖模拟底泥厌氧条件的方法,测定不同底泥厌氧水平下挺水植物美人蕉（Canna indica）的生物量、根表铁膜和植物组织内重金属的含量.结果表明:①底泥厌氧环境不利于美人蕉对Cd、Cr、Cu、Ni、Pb和Zn的吸收,随着厌氧程度的增加,美人蕉对重金属的吸收量逐渐减少.②底泥厌氧环境能促进根表铁膜的形成及其对Cr和Ni的富集,重度厌氧环境中根表铁膜的含量为（10.40±0.30）g/kg（以根干质量计）,但厌氧环境抑制了铁膜对Cd、Pb和Zn的富集.③底泥厌氧环境不利于Ni从根表铁膜转运至植物组织,但轻度厌氧环境能促进Cr和Zn从根表铁膜转运至根系,且底泥厌氧环境对Cd、Pb和Cu的迁移转运无显著影响.研究显示,底泥厌氧环境促进了植物根表铁膜的形成,根表铁膜对重金属积累和转运的影响因底泥厌氧水平和重金属元素种类不同而不同.      

Prenatal foetal diagnosis of partial trisomy 3q and monosomy 13p due to a maternal balanced rearrangement

The authors describe a case of a male foetus whose ultrasound at 20 weeks' gestation revealed cystic hygroma, cleft lip and ventricular septal defect. Amniotic fluid cytogenetics using GTG banding showed a 46,XY,der(13)t(3;13)(q12;p11.1) rearrangement, and fluorescence in situ hybridization (FISH) delineated the relevant breakpoints. Familial studies identified a maternal balanced translocation involving chromosomes 3 and 13. The post-mortem examination confirmed the prenatal ultrasound findings. Copyright © 2005 John Wiley & Sons, Ltd.