染色体型畸变率指标在射线工作者健康监护中应用的探讨

目的探讨染色体型畸变率增加在射线工作者健康监护中应用的意义。方法采用微量全血培养法,按WHO建议的标准对射线工作者(医用诊断X射线组、工业探伤组和海关货检组共772名及9名超剂量组)和40名正常人组进行染色体型畸变分析;职业外照射剂量用热释光剂量计测得。结果①各射线组的体型畸变率均比正常人增加了1～2倍,但两类人员的畸变类型均以无着丝粒畸变为主,占体型畸变率约95%,“双+环”等畸变极少;②体型畸变率的分布:95%的正常人畸变率<1%、其余为1%,各射线组的畸变率均分布在0%至≥3%的4个区段,其中2%和≥3%的2个区段合计为8.2%;③年剂量与体型畸变率分布:体型畸变率为2%和≥3%的2个区段中,年剂量当量<1mSv组仅占11.6%、3～19mSv组占66.6%、而>50mSv组(超剂量组)为100%;④各工龄组间体型畸变率的分布变化不大。结论在健康监护工作中,选择体型畸变率≥2%作为“预警值”较为合适;“双+环”或“稳定性畸变”的增加有较大的诊断价值;“预警值”应结合分析细胞量和其他指标综合判断才能得出客观的结论。

可注射性骨组织工程载体海藻酸钠-明胶共混体系的致畸突变试验

背景:利用组织工程学技术将各种凝胶系统作为支架材料对骨缺损进行修复日益受到重视。所选择的支架材料必须具有无毒、无致畸的特点。目的:观察海藻酸钠-明胶共混体系/成骨细胞凝胶修复兔颅骨缺损的愈合过程中对染色体畸变的影响。设计、时间及地点:材料学体内动物实验,于2007-10/2008-03在北京世纪坛医院和北京大学医学部组织胚胎学教研室完成。材料:清洁级2月龄新西兰纯种大白兔12只,随机分为2组:实验组8只,雌性4只,雄性4只,对照组4只均为雌性。海藻酸钠干粉为美国Sigma公司产品,明胶干粉为河北绿岛公司产品。方法:将12只兔编号后抽取骨髓,密度梯度离心法分离骨髓基质干细胞,加入成骨细胞诱导液进行体外培养,诱导分化的成骨细胞经传代增殖为107数量级。制备海藻酸钠与明胶质量比为2∶3的透明粉红色胶状液体,引入兔成骨细胞,细胞终浓度为5×109L-1,与CaCl2溶液混合,形成果冻样海藻酸钠-明胶共混体系/成骨细胞凝胶。12只兔颅骨均制备直径1.5cm的极限缺损,1周后实验组植入凝胶复合体0.5mL进行修复,对照组不植入任何材料。主要观察指标:缺损修复后3个月取心脏血观察细胞遗传学的变化。结果:①每只实验动物观察100个中期分裂细胞,均未见染色体型畸变。对照兔在400个中期分裂相中见4个,单体畸变率为1%。实验兔在800个中期分裂相中见12个,单体畸变率为1.5%。两组均在正常范围内。②每只实验动物做2个染色体核型分析,染色体数目2n=44,对照兔核型为44,XX,正常雌性;雄性实验兔为44,XY,未见异常;雌性实验兔为44,XX,未见到异常。结论:海藻酸钠-明胶共混体系/成骨细胞凝胶在细胞遗传学角度上是安全的。

Identification of a high frequency of chromosomal rearrangements in the centromeric regions of prostate cancer patients

The aim of the present investigation was to study the major chromosomal aberrations （CA） like deletion, translocation, inversion and mosaic in prostate cancer patients of Tamilnadu, Southern India. Totally 45 blood samples were collected from various hospitals in Tamilnadu, Southern India. Equal numbers of normal healthy subjects were chosen after signing a consent form. Volunteers provided blood samples （5 ml） to establish leukocyte cultures. Cytogenetic studies were performed by using Giemsaanding technique and finally the results were ensured by spectral karyotyping （SKY） technique. In the present investigation, major CA like deletion, translocation, inversion and mosaic were identifed in experimental subjects. Results showed frequent CA in chromosomes 1, 3, 5, 6, 7, 9, 13, 16, 18 and X. In comparison with experimental subjects, the control subjects exhibited very low levels of major CA （P〈0.05）. In the present study, the high frequency of centromeric rearrangements indicates a potential role for mitotic irregularities associated with the centromere in prostate cancer tumorigenesis. Identification of chromosome alterations may be helpful in understanding the molecular basis of the disease in better manner.