反复性流产患者染色体脆性位点的分析

目的探讨习惯性流产患者细胞遗传学病因。方法采用低叶酸TC199培养诱导法,观察了86例染色体核型无异常的反复自然流产患者染色体脆性位点,并观察了脆性位点的分布。结果实验组染色体脆性位点的频率为12%;对照组为4.94%,两组相比差异非常显著。染色体脆性位点的分布两组基本一致。结论反复性流产与染色体脆性位点频率增高有关与脆性位点分布关系不大。     

习惯性流产夫妇染色体脆性位点的观察

目的 探讨习惯性流产夫妇细胞细胞遗传学病因。方法 采用低叶酸TCl99培养诱导法，观察了3l对染色体核型无异常的习惯性流产夫妇染色体脆性位点，并观察了脆性位点的分布。结果实验组染色体脆性位点的频率为11．98％；对照组为4．95％，两组相比差异非常显著。染色体脆性位点的的分布两组基本一致。结论 习惯性流产与染色体脆性位点频率增高有关与脆性位点分布关系不大。     

染色体核型分析在男性不育症患者中的应用

目的研究染色体核型分析在男性不育症患者中的诊断价值。方法收集精液分析合并染色体核型分析593例,胚胎停滞发育染色体分析94例,并将其分为：无精子症组,少精子症组,弱精子症组,及胚胎发育停滞组,综合分析各组染色体核型,分析异常的比例及分布特点。结果无精子症组染色体畸形率为29.4%,少精子症组患者中的染色体畸形率为18%,胚胎停止发育组中染色体畸形率41.2%,弱精子症及精子基本正常组染色体畸形率分别为10.8%及6.1%,无精子症及胚胎停滞发育组畸形率明显高于精液正常组。结论生精功能障碍越严重,染色体异常核型检出率越高,对生精功能障碍及胚胎发育停滞的患者,应必须进行染色体核型分析。     

染色体异常与男性生精功能关系的探讨

目的探讨染色体异常对男性不育症患者精液及睾丸发育的影响。方法对330例男性不育患者进行染色体核型分析,据其结果分为染色体核型正常组260例和染色体核型异常组70例,并就两组患者的精液及睾丸发育情况进行统计学分析。结果 1.染色体正常组无精症发生率为43.1%,少弱精发生率为35.9%;染色体异常组中性染色体异常、常染色体异常、染色体多态性改变无精症发生率分别为93.6%、71.4%和56.3%,均明显高于染色体正常组。三组少弱精的发生率分别为6.4%、28.6%和37.5%。2.染色体正常组小睾异常率为21.5%;染色体异常组中性染色体异常、常染色体异常、染色体多态性改变无精症发生率分别为95.7%、0%和37.5%。结论染色体异常会导致不同程度的生精功能异常和小睾症的发生,对男性不育患者进行染色体检查有利于指导治疗。     

厦门地区染色体检查在男性不育患者中应用的探讨

目的 探讨染色体核型分析对男性不育诊断的意义.方法 收集染色体核型分析合并精液分析1321例,将其分为无精子症组、重度少弱精予症组、少弱精子症组和精液正常组,综合分析染色体核型异常的比例及分布特点.结果 无精子症组和重度少精子症组染色体畸变率分别为26.92%和11.2l%,明显高于精液正常组.少弱精子症组染色体畸变率为8.12%,与精液正常组4.89%比较也有明显差异.结论 生精功能障碍越严重,染色体异常核型检出率越高.对生精功能障碍及精液正常但原因不明的男性不育患者,染色体核型分析应为其必要检查.     

染色体畸变与男性不育关系的探讨——附1397例检测结果分析

目的探讨染色体核型分析对男性不育诊断的重要意义。方法收集染色体核型分析合并精液分析1397例,将其分为无精子症组、重度少弱精子症组、少弱精子症组、精液正常组,综合分析各组染色体核型异常的比例及分布特点。结果无精子症组和重度少精子症组染色体畸形率分别为29.50%和8.64%,明显高于精液正常组。少弱精子症组染色体畸形率为5.28%,与精液正常组2.31%比较也有显著差异。且4组病例与育龄人群的染色体畸形率0.59%[1]比较都有显著性差异。结论生精功能障碍越严重,染色体异常核型检出率越高。对生精功能障碍及精液正常但原因不明的男性不育患者,染色体核型分析应为其必要检查。     

睾丸生精功能障碍患者染色体异常核型及多态性分析

目的研究男性睾丸生精功能障碍与染色体异常核型及多态性关系。方法对299例睾丸生精功能障碍患者进行染色体核型分析和精液常规检测,并对其结果进行对比分析。结果染色体异常57例(19.1%),染色体多态性62例(20.7%)。染色体异常在无精子症组中为34.5%,在少精子症组中为13.0%;染色体多态性在无精子症组中为32.1%,在少精子症组中为16.3%,两组之间差异均有统计学意义。核型异常主要表现为克氏征和平衡易位,其中克氏征占35.1%,平衡易位占19.3%;无精子症主要以克氏征为主占69.0%;少精子症以平衡易位为主占39.3%。睾丸生精功能障碍患者染色体多态性的类型主要包括小Y、大Y、长臂次缢痕增加、随体多态性、9号染色体倒位。其中Y染色体多态性占所有多态性的64.5%,在无精子症组占63.0%,在少精子症组占65.7%。次缢痕增加和随体多态性分别占所有多态性的11.3%,9号染色体倒位占12.9%。结论染色体核型异常及多态性与男性睾丸生精功能障碍有密切关系。     

非特异型精神发育迟滞患者的染色体脆性位点研究

为了解精神发育迟滞患者染色体的稳定性及与临床的关系,采用低叶酸TC199培养诱导法,对300名非特异型精神发育迟滞患者作染色体脆性位点表达检测和断裂点细胞频率统计。结果普通型脆性位点表达23例(7.7%),遗传型脆性位点表达31例(10.3%),染色体断裂或裂隙的细胞频率10.8%,与正常对照组相比较,差异均有显著性,本文认为这类患者较高的脆性位点阳性表率和断裂点细胞频率,是其染色体不稳定性的表现之一。     

先天性智能低下儿的染色体脆性位点探讨

对１０４例先天性智能低下儿和３７例正常儿分别进行叶酸敏感型染色体脆性位点表达、外周血淋巴细胞培养、染色体制备和核型分析，结果为：智能低下儿染色体脆性位点表达率明显高于正常儿（Ｐ＜０．０１）。脆性位点在各组（Ａ－Ｇ）和Ｘ染色体表现众数为Ａ、Ｃ组，表达率较高为Ａ、Ｃ组和Ｘ染色体。本文研究不仅得出了染色体脆性位点的表达和分布，而且进一步说明了染色体脆性位点的检测对智能低下儿的诊断提供了有价值的实验资料。     

低智儿童常染色体脆性位点的研究

本文通过对７５例正常儿童智力低下儿童的外周血淋巴细胞染色体脆性位点,结果表明;智力低下儿童常染色体脆性位点频率明显高于正常对照组（Ｐ〈０．０５）;轻度,中度和重度智力低下儿童的脆性位点频率之间无显著差异（Ｐ〉０．０５）。说明智低儿童存在染色体不稳定的遗传基础,而这种染色体不稳定性与智力低下的程度无关。     

No difference in expression of chromosomal fragile sites in patients with solid malignant tumours and normal controls

The frequency and distribution of rare and common chromosomal fragile sites in metaphases derived from peripheral lymphocytes were compared in 26 patients with malignant solid tumours and 24 normal controls. In order to avoid bias in evaluation, the identity of each individual as patient or control was disclosed only after the study was completed. Rare heritable folic acid inducible fragile sites were found in five patients (2q13; 6p23; 8q22; 16p12) and two controls (8q22). Common fragile sites were present in 21 of 26 patients and in 19 of 24 controls. These differences are statistically not significant in the Fisher test. We conclude that the expression of fragile sites does not indicate a predisposition for solid tumours.     

Reduced expression of aphidicolin-induced common fragile sites in peripheral lymphocyte chromosomes of patients with B-cell chronic lymphocytic leukemia

The occurrence and frequency of aphidicolin-induced common chromosomal fragile sites were examined in 12 B-cell chronic lymphocytic leukemia (B-CLL) patients (ten males and two females) and three normal individuals. The mononuclear cells separated by Ficoll-Hypaque gradient were cultured in vitro for 96 hours stimulated by pokeweed mitogen (PWM) in combination with T-leukemia cell conditioned medium or 10% B-cell growth factor. For the final 24 hours the cells were treated with aphidicolin (0.07 microgram/ml). Results indicate that there was a significant reduction in the overall mean frequency of common fragile sites in CLL patients with a wide individual variation. Fragile sites were found to be localized either on a single chromatid or both chromatids, but rarely involved homologous chromosomes. No definite relationship between the frequency of fragile sites and the staging of CLL disease was observed. A significant reduction and variability in the frequency of fragile sites suggest the heterogenous nature of B-CLL and probably a different mechanism of induction of fragile sites in CLL cells compared to controls.     

Chromosomal breakage in normal and fragile X subjects using low folate culture conditions.

To investigate whether the fragile X syndrome is associated with a generalised chromosomal instability, we compared the frequency and distribution of chromosomal breakage in lymphocytes grown in low folate medium from normal subjects and from patients with the syndrome. Although low folate conditions increased the rate of chromosome breakage, no difference in frequency or distribution of chromosomal breakage was found between the two groups. This suggests that the fragile X syndrome is not associated with a generalised chromosome instability expressed in folate deficient medium and assessed in terms of chromosomal breakage.     

The expression frequency of common fragile sites and genetic susceptibility to lung cancers

The chromosomal aberration rate (including gap and break) and expression frequency of common fragile sites were examined in peripheral blood lymphocytes cultured with TC199 medium from 96 patients with lung cancers, 40 of their first-degree relatives, and 45 normal control subjects. Both the chromosomal aberration rates and expression frequencies of common fragile sites observed in patients and their relatives were significantly higher than those in normal control subjects. About 60% of chromosomal aberrations were derived from the expression of common fragile sites either in the patients and their relatives or in the controls. The expression of fra(3)(p14) was most frequently observed, and the mean frequencies of its expression in patients and their relatives were significantly higher than in control subjects. It is suggested that common fragile sites might be unstable factors of the human genome, and their expression might be affected by some genetic factors, and they might play an important role in the genetic susceptibility to lung cancers. The significantly high expression of fra(3)(p14) in patients and their relatives may be related to the generation of the breakpoint at band 3p14 found in lung cancers.     

Type I bipolar disorder associated with a fragile site on chromosome 1

The objective of this paper is to study the association between chromosomal fragile sites and type I bipolar disorder. This case-control study compares bipolar patients with normal controls. Ten cases of type I bipolar disorder diagnosed according to DSM-III-R criteria and the Composite International Diagnostic Interview (CIDI) were selected from the Escola Paulista affective disorders outpatient clinic and 10 healthy controls (CIDI negative for psychiatric diagnoses) matched for sex and age were drawn from the otorhinolaryngologic outpatient clinic of the same hospital. The cytogenetic analysis was carried out with blood lymphocytes, which were cultured in a folic acid--free medium. A total of 100 mitoses per subject were blindly analyzed to the psychiatric diagnostic assignment, and fragile sites were identified according to a minimum expected frequency of events per band in conformity with a Poisson distribution. A higher frequency of chromosomal lesions for cases than controls was found for the following bands: 1q32, 5q31, and 11q23, the 1q32 being considered a fragile site. Although no evident neuropsychiatric etiological component has been mapped to the 1q32 region so far, this finding may lead to further investigation of a possible linkage between genetic markers of this region and bipolar disorder. © 1995 Wiley-Liss, Inc.     

Common fragile sites: their prevalence in subjects with constitutional and acquired chromosomal instability

Chromosomal fragile sites that are inducible by methotrexate and aphidicolin are frequent in the human population. To assess the frequency and distribution of these common fragile sites, we performed a cytogenetic survey on lymphocytes from subjects known to be particularly prone to breakage because of constitutional chromosomal instability, the possession of a rare fragile site, or Fanconi anemia. Furthermore, a group of cancer patients was included in this study in view of possible acquired chromosomal instability. Lymphocyte chromosomes from several healthy donors were analyzed under identical conditions. We found that methotrexate- and aphidicolin-induced fragile sites are widespread in the general population, showing a similar breakpoint distribution. Ten fragile sites (3p14, 16q23, 2q32, 6q25, 4p16, 4q31, 14q24, 1p31, 20p12, 7q21) were observed in at least 40% of the individuals among the different groups. Our data point out a significantly increased breakage induced by aphidicolin in lymphocytes from cancer patients and, to a lesser extent, from rare fragile sites carriers. These results suggest that common fragile sites are enhanced in some constitutional and acquired conditions.     

The expression frequency of common fragile sites and genetic predisposition to colon cancer

The expression frequency of common fragile sites induced by aphidicolin (Apc), bromodeoxyuridine (BrdU), and caffeine was evaluated on prometaphase chromosomes obtained from the peripheral blood lymphocytes of 32 patients with colon cancer, 30 of their clinically healthy family members and 30 age-matched normal controls. The proportion of damaged cells (P < 0.001), the mean number of chromosomal aberrations and the expression frequencies of fragile sites were significantly higher in the patient and relative groups compared to the control group. Our findings show an increased genetic instability in patients with colon cancer and their first-degree relatives. In addition, common fragile sites can be used as a suitable marker for determining genetic predisposition to cancer.     

Common fragile sites in chromosomes of bone marrow cells and peripheral blood lymphocytes from healthy persons and leukemia patients

Frequency and distribution of aphidicolin-induced fragile sites (c-fra) on chromosomes of both peripheral blood lymphocytes (PBL) and bone marrow (BM) from 15 leukemia patients were studied in comparison with 22 PBL and six BM samples from healthy volunteers. In normal controls, the most frequent c-fra was 3p14 in PBL, but it was 4q21-25 in BM. The second most frequent site was 16q23 in PBL, but it was 7q11.2 in BM. These differences in fragile sites between PBL and BM may be related to distinct functions of cells in different tissues. The total number of breaks in PBL and BM showed a significant difference among individuals, but the sites were generally common. The frequency of breaks in PBL from leukemia patients was higher than in controls when the leukemic cells had any karyotypic abnormalities. In leukemia without karyotypic abnormalities and acute myeloid leukemia (AML) with (15:17), the frequency of breaks fell within normal or slightly above normal ranges. Breaks at 3p14 (22.0% of total breaks), 16q23 (7.3%), 7q32 (4.3%), Xp22 (3.7%), and 6q26 (2.9%) were frequent in PBL from seven AML patients. Breaks at 4q21-25 (2.1%), 7q22 (2.2%), 7q32, and Xp22 were more frequently induced than in controls, and 1p32 (0.1%), 3p14, 6q26, and 16q23 were less often expressed than in controls. On the other hand, PBL from acute lymphoblastic leukemia patients showed a higher frequency of breaks only at 1p22 (3.4%) and the frequency of breaks at 3p14 (30.2%) decreased (p less than 0.05). The PBL from AML patients with t(8;21) (q22;q22) showed breaks at 8q22 and 8q24, and the frequencies were significantly higher than those of other types of leukemia or in controls (p less than 0.001). The results of this study suggest that fragility of chromosomes may be related to the chromosomal rearrangement in or predisposition to leukemia.     

Chromosome instability in lymphocytes from two patients affected by three sequential primary cancers: the role of fragile sites

The chromosomal aberration rate and the expression of fragile sites induced by aphidicolin were evaluated in metaphase chromosomes obtained from peripheral blood lymphocytes of two untreated patients with multiple primary cancers. Spontaneous aberrations of chromosome number and structure and chromosome fragility were compared with controls with the use of the same methods. Chromosomal aberration rates and expression frequencies of fragile sites were significantly higher in the patients than in normal control subjects. In the patients, all but one structural chromosome aberration involved at least one fragile site. Our results suggest that fragile sites may be unstable regions of the human genome, which might play an important role in the genetic instability associated with cancer predisposition.     

肺癌患者淋巴细胞染色体脆性位点表达的研究

作者检测了３０例肺癌患者和２０例正常对照个体自发和阿糖胞苷诱发的外周血淋巴细胞染色体脆性位点表达率。结果显示：患者组自发和阿糖胞苷诱发的脆性位点表达率显著高于对照组。提示肺癌患者的染色体不稳定性高是其患癌易感性的重要遗传基础。本文还讨论了常见型脆性位点３ｐ１４的高表达率与肺癌的关系，以及肺癌患者的脆性位点与癌断点、癌基因、抗癌基因的相关性等问题。