交通污染暴露对DNA甲基化的影响

探讨交通污染现场暴露对DNA甲基化的影响.30只8周龄Wistar大鼠按随机数字表法随机分5组,每组6只.其中3组分别在隧道(高暴露组)、路口(中暴露组)、校园(对照组)暴露7 d,另外2组分别在隧道暴露14 d/28 d.在暴露过程中检测3个暴露地点PM_(10)、NO_2的浓度.暴露实验分别在春季、秋季各进行一次.暴露结束后,焦磷酸测序法检测肺组织和血液中DNA(p53、MGMT、MAGE-A4)甲基化水平,并分析比较不同暴露组间DNA甲基化水平的差异.结果表明,PM_(10)、NO_2浓度均为隧道(高暴露组)路口(中暴露组)校园(对照组),差异具有统计学意义.秋季暴露7 d后,与对照组相比,肺组织中p53(P_(路口)=0.016;P_(隧道)=0.019)、MGMT(P_(路口)=0.002;P_(隧道)=0.003)启动子甲基化水平显著降低,随着暴露时间的增加,甲基化水平进一步降低;MAGE-A4启动子区处于高度甲基化状态,在肺组织和血液中,均未发现MAGE-A4启动子甲基化水平在三暴露组间存在显著的统计学差异.7d暴露对肺组织中DNA甲基化水平的影响更大,但随着暴露时间的增加,肺组织和血液中DNA甲基化水平改变模式趋于一致.Spearman相关分析结果显示,在肺组织中,PM_(10)和p53甲基化水平呈负相关关系(r=-0.347;P=0.038);NO_2和p53、MGMT、MAGE-A4甲基化水平均存在负相关(r值分别为-0.482、-0.444、-0.346,P值均0.05).在血液中,MAGE-A4甲基化水平与PM_(10)、NO_2均呈正相关(r值分别为0.395、0.431,P值均0.05).交通污染暴露会引起p53、MGMT启动子低甲基化.     

Tetrasomy 12p—unusual presentation in CVS

CVS direct preparations usually achieve limited resolution and are better at detecting numerical rather than structural abnormalities. A CVS direct preparation analyzed using G-banding revealed a 47,XY,+G karyotype in 5 of 11 cells and was reported as mosaic for trisomy 21. Subsequent analysis of the CVS culture found only normal male cells. Amniocentesis revealed both normal male cells and cells with an extra F-group chromosome. Fluorescence in situ hybridization (FISH) identified this chromosome to be an isochromosome from the short arm of chromosome 12 [i(12)(p10)]. The amniocyte karyotype was reported as 47,XY,+i(12)(p10)[12]/46,XY[8].ish i(12)(p10)(wcp12+), which is associated with Pallister–Killian syndrome. Reexamination of the CVS direct preparation by FISH with a chromosome 12 centromere probe confirmed the karyotype of this tissue to be 47,XY,+mar[5]/46,XY[6].nuc ish 12cen(D12Z3 × 3)/12cen(D12Z3 × 2). Thus, multiple studies, including amniocentesis and fluorescence in situ hybridization, may be required to fully and accurately evaluate abnormalities detected by CVS. This case also indicates that mosaicism for supernumerary isochromosomes may have a complex origin. Copyright © 2003 John Wiley & Sons, Ltd.     

测定地表水中微量亚硝酸盐的灵敏光度法

研制了一种测定微量亚硝酸盐的灵敏光度法。在pH1 0～ 2 0盐酸介质中 ,亚硝酸盐与对氨基苯乙酮 萘乙二胺形成可溶于水的红紫色染料 ,其最大吸收波长为 5 5 0nm ,摩尔吸光系数为 5 78× 10 4L mol·cm。 0～ 3 6 μg 2 5mL的亚硝酸盐遵守比尔定律 ,方法应用于测定地表水中微量亚硝酸盐 ,获得了满意的结果     

Chemical behavior of organic compounds in the interface of water/dual-cation organobentonite

The sorption behavior of polar of ionizable organic compounds,such as p-nitrophenol,phenol and aniline,in the water/organobentonite systems is investigated.Both adsorption and partition occur to the sorption of organic compounds to dual-cation organobentonites.The separate contributions of adsorption and partition to the total sorption of organic compounds to dual-cation organobentonites are analyzed mathematically in the first time.The factors to the contributions are also discussed.The results indicated that the contribution of adsorption and partition is related to the composition and ratio of dual-cation surfactants exchanging onto the bentonite.The sorption of organic compounds to dual-cation organobentonite is dominated by adsorption at low concentrations and by partition at high concentrations,making the organobentonites powerful sorbents for organic contaminants over wide range of concentrations.     

Prenatal diagnosis of charcot-marie-tooth disease type 1a (CMT1A) using molecular genetic techniques

Charcot-Marie-Tooth disease type 1A (CMT1A) is a frequent hereditary motor and sensory neuropathy of the peripheral nerves. In most cases, the disease is associated with a 1.5 Mb tandem duplication at 17p11.2. A 42-year-old pregnant woman requested prenatal diagnosis because of her age and since both her husband and two children were severely affected with CMT1. The CMT1A duplication was demonstrated in the father's, the two children's, and the fetus's DNA using different molecular genetic methods. Although cytogenetical analysis showed a normal female karyotype in the fetus, the parents decided to terminate the pregnancy because of the genetic risk associated with the CMT1A duplication.     

灌溉污水中苯并(a)芘最高容许浓度的探讨

苯并(a)芘是一种强致癌物,在环境和食品中普遍存在,并能在土壤和生物体内蓄积,最高容许浓度的确定应考虑到环境中的“本底”水平和灌溉水中的实际含量以及对机体的毒理危害程度,建议灌溉污水中苯并(a)芘的最高容许浓度为0.05μg/L.     

Prenatal diagnosis of trisomy 4p: a new locus for holoprosencephaly?

Trisomy of the short arm of chromosome 4 is a well-known syndrome, and several observations have been made in the last 30 years. Herein, we report a new observation of trisomy 4p in a fetus with a semi-lobar holoprosencephaly (HPE), dysmorphic features and multiple malformations. The diagnosis of HPE was made, at 33 weeks' gestation, on the fetus of a healthy G1P0 woman. Amniocentesis was performed for chromosome analysis and additional material was found on a chromosome 22. The couple elected to terminate the pregnancy and fetal examination was realized. Conventional and molecular cytogenetic studies were performed on the fetus and the parents, which showed that the additional material found on one chromosome 22 corresponded to the short arm of chromosome 4 and therefore led us to establish a diagnosis of trisomy 4p inherited from the malsegregation of a paternal translocation t(4;22)(q12;q11.1). The etiology of HPE is very heterogeneous; it includes non-genetic factors such as maternal diabetes and genetic causes. HPE cases have been described in association with many chromosomal anomalies, trisomy 13 being the most frequent. However, to our knowledge, HPE has never been previously reported in association with a trisomy involving solely the short arm of chromosome 4. Copyright © 2005 John Wiley & Sons, Ltd.