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1.
回顾性总结患者核型资料,为产前诊断提供依据。对776例分娩畸形、死胎、习惯性流产患者进行染色体检查,共检出异常核型25例,占受检人数的3.2%,其中平衡易位携带者13例,臂间倒位5例,性染色体异常7例。这表明染色体异常是导致畸形、死胎、习惯性流产的重要原因。在遗传咨询门诊中,应对患者进行染色体检查,若再次妊娠,则应进行生育指导。  相似文献   

2.
通过对本地区9号染色体倒位患者发生率及临床表现的分析,探讨9号染色体倒位与临床效应的关系,为临床遗传咨询提供理论依据。采用微量全血培养及染色体标本制备技术,进行外周血染色体检查。结果显示1314例案例中发现9号染色体臂间倒位6例,发生率为0.46%;发生倒位的断裂点p11一例,p12两例,p13两例,p21一例;q12两例,q13三例,q21一例。说明9号染色体的倒位节段通常为p12→q13。9号倒位携带者会引起不良的遗传效应,如造成流产、不孕、不育、畸胎、其他遗传病患儿。  相似文献   

3.
目的:通过对2 450例有自然流产、死胎、畸胎、少精等不良孕育史的患者的染色体结果调查,探讨平衡易位与不良孕育史的关系。方法:取外周血进行淋巴细胞培养,染色体G显带分析。结果:2 450例患者中检出染色体平衡易位22例(罗伯逊易位3例),占0.90%。患者表现为自然流产、死胎、畸形儿、少精等不良孕育史。结论:染色体平衡易位是导致患者不良孕育史的重要原因之一。对这类人群进行遗传优生和产前诊断及辅助生殖指导等有针对性的检查和临床干预是非常必要的。  相似文献   

4.
对103例非梗阻性无精子症患者进行常规外周血染色体G显带核型分析、AZF微缺失筛查、精浆生化指标和血清生殖激素定量检测.103例非梗阻性无精子症患者中,染色体核型异常16例,异常率15.53%,其中Klinefelter综合征8例,占异常总数的50.00%,其它性染色体异常5例,占异常总数的31.25%;AZF微缺失18例,缺失率17.48%,其中AZFc区缺失11例,占缺失总数的61.11%;染色体微缺失患者精浆锌浓度与染色体正常组患者比较,差异有统计学意义(P<0.05);染色体核型异常患者果糖浓度与染色体正常组患者比较,差异有统计学意义(P<0.05),尤其是Klinefelter综合征患者果糖浓度显著升高,差异有统计学意义(P<0.01);染色体核型异常患者FSH、LH均显著高于染色体正常组患者,差异有统计学意义(P<0.05),Klinefelter综合征患者T浓度则低于染色体正常组患者,差异有统计学意义(P<0.05);其他核型异常及Y染色体微缺失患者E2浓度显著高于染色体正常组患者,差异有统计学意义(P<0.05).  相似文献   

5.
流产的原因     
<正> 流产是产科常见的异常情况,占妊娠总数的10—20%。流产由多种因素引起,一般分为母体因素,胚胎因素及外界因素。诸如母亲严重的急慢性疾病、生殖器官的异常及疾病,内分泌失调、血型不合、精、卵细胞的缺陷、胚胎附浸物的异常及病变,外伤、精神刺激、腹部手术、药物中毒等.近几十年来,随着遗传、生殖生理、内分泌及免疫学研究的进度,由这些方面所引起的流产,日益受到重视,现就这几方面造成的流产,予以综述。一、染色体异常:60年代初开始有关于染色体异常而致流产的报导,1966年国际卫生组织公布流产儿染色体异常率为19.4%,随着研究的深入,发现染色体异常是造成流产的最大  相似文献   

6.
利用空气干燥法对采自河南境内太行山脉十字岭、张沟、八里沟3产地淡水三角涡虫(Dugesiasp)的染色体和核型进行了研究.结果表明:十字岭淡水三角涡虫(Dugesia sp)体细胞中染色体数目以24条为主(2n=3x=24=24m),占84.56%,少数为16条(2n=2x=16=16m),占8.98%,染色体基数为8,为二倍体和三倍体的混合倍体;张沟淡水三角涡虫(Dugesiasp)体细胞中染色体数目以25条为主(2n=3x+1=24+1SB=21m+3sm+1SB),占80.84%,含有一条小B染色体,少数为24条(2n=3x=24=21m+3sm),占15.99%,极少数为32条,占3.17%,染色体基数为8,为三倍体、四倍体和三倍性非整倍体的混合倍体;八里沟淡水三角涡虫(Dugesiasp)的体细胞中染色体数目以24条(2n=3x=24=24m)和32条(2n=4x=32=32m)为主,分别占38.21%和39.77%,染色体基数为8,为三倍体和四倍体的混合倍体,该产地部分三倍体个体体细胞中染色体结构发生变异,个别染色体末端有随体,其核型呈现多型性.  相似文献   

7.
京杭大运河徐州段水质底栖动物多样性及BPI评价   总被引:6,自引:0,他引:6  
对京杭大运河徐州段8个断面底栖动物群落结构特征、种类组成、物种多样性进行了研究,并用群落Shannon-Wiener多样性指数(H’)、生物学污染性指数(BPI)、Goodnight-Whitley生物指数(G.I)和Trent生物指数(TBI)方法对大运河水质进行了综合评价.结果表明,底栖动物涉及24种,其中水生昆虫2种,占总种数的8.33%;软体类9种,占总数的37.50%;寡毛类11种,占总数的45.83%;甲壳类和蛭类各1种,各占总数的4.17%.寡毛类中中华颤蚓(Tubifex sinicus)和霍甫水丝蚓(Limnodrilus hoffmeisteri)在各断面都有出现,且它们也是各断面的第一和第二优势种,其它种类在各断面分布形式差异很大.除TBI外,其他3种指数水质评价结果基本一致,均表明大运河徐州段水质属于中污染,其中蔺家坝和解台闸两断面污染较轻.  相似文献   

8.
对贵州紫云县格凸河景区进行陆生贝类资源调查,共获标本1 538号,经鉴定,得44种(含6个未定种),隶属于9科24属。区系分析表明:贵州紫云县格凸河景区陆生贝类区系组成以东洋界种类为主,占种类总数的84.21%,其中以东洋界西南区种类为主,占种类总数的39.47%;同时也有少数古北界的种类渗透,占种类总数的10.53%;广分布种类较少,仅占种类总数的5.26%。  相似文献   

9.
对844例遗传咨询患者的外周血染色体进行了分析,检出染色体异常型26例,占受检人数的3.08%。常染色体异常中,平衡易位5例,其中2例丈夫染体为平衡易位,致妻反复流产,说明在流产夫妇中检查丈夫染色体的必要性。  相似文献   

10.
目的:探讨遗传性疾病的细胞遗传学基础.方法:对756例遗传咨询者进行外周血淋巴细胞染色体分析.结果:发现异常核型126例,异常检出率16.67%.结论:智力低下、流产、死胎、生育畸形儿、性发育不全及生殖力低下者的染色体检查,均有细胞遗传学改变.  相似文献   

11.
Rare cases of chronic lymphocytic leukaemia (CLL) in man stem from the malignant proliferation of T cells. The disease is usually more aggressive clinically than B-cell-derived CLL. Various haematological tumours are associated with specific chromosome aberrations (for example, refs 1, 2). Only limited numbers of T-cell CLL patients have so far been studied cytogenetically and, whereas chromosome 12 seems particularly to be involved in B-cell CLL, several markers have been found in T-cell tumours. Recently, by stimulating malignant clones with different mitogens, novel chromosome abnormalities have been detected in T-cell CLL. Using the same approach for additional cases of T-cell CLL, we now report that the most consistent chromosome change is an inversion of the long arm of chromosome 14, inv(14)(q11 q32), in four of five patients. Another remarkable chromosome aberration is trisomy for the long arm of chromosome 8, found in three of five patients.  相似文献   

12.
After the completion of a draft human genome sequence, the International Human Genome Sequencing Consortium has proceeded to finish and annotate each of the 24 chromosomes comprising the human genome. Here we describe the sequencing and analysis of human chromosome 3, one of the largest human chromosomes. Chromosome 3 comprises just four contigs, one of which currently represents the longest unbroken stretch of finished DNA sequence known so far. The chromosome is remarkable in having the lowest rate of segmental duplication in the genome. It also includes a chemokine receptor gene cluster as well as numerous loci involved in multiple human cancers such as the gene encoding FHIT, which contains the most common constitutive fragile site in the genome, FRA3B. Using genomic sequence from chimpanzee and rhesus macaque, we were able to characterize the breakpoints defining a large pericentric inversion that occurred some time after the split of Homininae from Ponginae, and propose an evolutionary history of the inversion.  相似文献   

13.
多重集上的Mahonian统计(英文)   总被引:1,自引:0,他引:1  
设M={x1^a1,…xm^am}是基数为n=a1 a2 …am的多重集,S(M)表示M的所有置换的集合,本文给出了q^inv(π)的组合解释,其中π∈S(M),inv(π)表示π的逆序数,这表明一个著名的组合恒等式有了一个组合的证明。  相似文献   

14.
C T Denny  Y Yoshikai  T W Mak  S D Smith  G F Hollis  I R Kirsch 《Nature》1986,320(6062):549-551
Specific chromosomal aberrations are associated with specific types of cancer (for review see ref. 1). The distinctiveness of each association has led to the belief that these chromosomal aberrations are clues to oncogenic events or to the state of differentiation in the malignant cell type. Malignancies of T lymphocytes demonstrate such an association characterized most frequently by structural translocations or inversions of chromosomes 7 and 14 (refs 7-9). Analyses of these chromosomally marked tumours at the molecular level may therefore provide insight into the aetiology of the cancers as well as the mechanisms by which chromosomes break and rejoin. Here we report such an analysis of the tumour cell line SUP-T1 derived from a patient with childhood T-cell lymphoma carrying an inversion of one chromosome 14 between bands q11.2 and q32.3, that is, inv(14) (q11.2; q32.2). These are the same chromosomal bands to which the T-cell receptor alpha-chain (14q11.2) and the immunoglobulin heavy-chain locus (14q32.3) have been assigned. Our analysis reveals that this morphological inversion of chromosome 14 was mediated by a site-specific recombination event between an immunoglobulin heavy-chain variable region (Ig VH) and a T-cell receptor (TCR) alpha-chain joining segment (TCR J alpha). S1 nuclease analysis shows that this hybrid gene is transcribed into poly(A)+ RNA.  相似文献   

15.
Chromosome 9 is highly structurally polymorphic. It contains the largest autosomal block of heterochromatin, which is heteromorphic in 6-8% of humans, whereas pericentric inversions occur in more than 1% of the population. The finished euchromatic sequence of chromosome 9 comprises 109,044,351 base pairs and represents >99.6% of the region. Analysis of the sequence reveals many intra- and interchromosomal duplications, including segmental duplications adjacent to both the centromere and the large heterochromatic block. We have annotated 1,149 genes, including genes implicated in male-to-female sex reversal, cancer and neurodegenerative disease, and 426 pseudogenes. The chromosome contains the largest interferon gene cluster in the human genome. There is also a region of exceptionally high gene and G + C content including genes paralogous to those in the major histocompatibility complex. We have also detected recently duplicated genes that exhibit different rates of sequence divergence, presumably reflecting natural selection.  相似文献   

16.
探讨了染色体技术对临床诊断某些疾病的应用价值 .应用常规外周血淋巴细胞染色体标本制备 ,G显带、C显带技术 ,脆性X染色体分析 .结果从 3 89例患者中检出异常核型 46例 ,检出率为 11.83 % .其中罗伯逊易位携带者 6例 ,平衡易位携带者10例 ,倒位携带者 4例 ,性染色体异常者 14例 ,先天愚型及发育异常者 12例 .结果表明 ,染色体技术是某些遗传性疾病临床诊断必不可少的手段 ,异常染色体的检出对患者的治疗、预后及优生、优育、优教都有重要指导意义 .  相似文献   

17.
M M Le Beau  M O Diaz  M Karin  J D Rowley 《Nature》1985,313(6004):709-711
The metallothioneins (MTs) are a family of proteins of low relative molecular mass which bind heavy-metal ions. MTs exist in several molecular forms (MT-I, MT-II) and are encoded by a multi-gene family containing at least 14 closely related genes and pseudogenes. These proteins function in the regulation of trace-metal metabolism, the storage of these ions in the liver, and as a protective mechanism against heavy-metal toxicity. Somatic cell hybridization has shown that most MT genes, including the functional MT genes (MT1A, MT1B, MT2A), lie on human chromosome 16. Using in situ hybridization, we have now localized the MT genes to band q22 of chromosome 16. This chromosomal band is also a breakpoint in two specific rearrangements, the inv(16)(p13q22) and t(16; 16)(p13;q22) rearrangements, found in a subgroup of patients with acute myelomonocytic leukaemia (AMML). Hybridization of a MT probe to malignant cells from two patients with an inv(16) showed labelled sites on both arms of the inverted chromosome, indicating that the breakpoint at 16q22 splits the MT gene cluster. Similar results were obtained when this probe was hybridized to metaphase cells from two patients with a t(16; 16). These results suggest that the MT genes or their regulatory regions may function as an 'activating' sequence for an as yet unidentified cellular gene located at 16p13.  相似文献   

18.
A primary physical map of rice chromosome 12 was constructed using marker-based chromosome landing and chromosome walking. A BAC library from IR64 was screened using 84 RFLP markers, 4 STS markers and 6 microsatellite markers on chromosome 12 by colony hybridization and polymerase chain reaction (PCR) amplification. A total of 59 contigs consisting of 419 BAC clones including 5 single-clones were physically aligned on rice chromosome 12 with the largest BAC contig covering 855 kb. The whole physical map had a size of ∼16 Mb and covered about 52% of rice chromosome 12. This physical map will be certainly helpful for map-based gene cloning of agronomically and biological important genes and understanding the genome structure of the chromosome. Foundation item: Supported by Rockefeller Foundation Biography: FU Bin-Ying (1965-), male, Ph. D. candidate, Reseach direction: plant molecular genetics.  相似文献   

19.
针对自适应搜索算法在海温垂直结构冲激响应特征提取中运算速度慢、精度低的不足,引入共轭梯度反卷积算法CG(conjugate gradient method),得到海温垂直结构的冲激响应,利用层剥算法对所求得的冲激响应进行反演,得到海温垂直结构特征。结果表明:该算法能够克服单纯使用层剥算法而带来的反演不稳定现象,而且相比自适应搜索算法,反演速度快,反演精度高,具有一定的抗噪能力,并且声源信号的入射波形对反演效果影响较小,不同的迭代终止条件对反演结果也有较大的影响,在适当的范围内,减小迭代终止条件可以提高反演的精度,但是,如果迭代终止条件过小,则会引起虚假振荡,造成反演结果发散。  相似文献   

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