氟苯咪唑CHL培养细胞染色体畸变研究

氟苯咪唑(Fludendazole)由Gelder于1969年合成,直到最近几年才受到各国重视,我国于1983年也合成了该化合物。该药经临床应用疗效显著,抗虫效力高,抗虫谱     

Mitotic and meiotic detection of radiation-induced translocations in mouse stem cell spermatogonia using fluorescencein situ hybridization

The efficiency of two methods of detection of translocations induced in mouse stem cell spermatogonia by X-ray doses of 2, 5 and 7 Gy was compared: classical multivalent analysis at diakinesis-metaphase I of meiosis and observation via fluorescencein situ hybridization analysis of mitotic or meiotic stages. Specific DNA libraries for chromosomes 1, 11 and 13 were used. The results obtained indicate that (a) chromosomes 1, 11 and 13 are more involved in multivalent formation than expected on the basis of DNA content and (b) if the mitotic FISH analysis data are corrected for the observed over-representation, the frequencies of induced translocations are similar to those recorded in the classical multivalent studies, suggesting equal scoring efficiencies in both systems.     

东莨菪碱诱发染色体畸变的剂量效应

东茛菪碱五个剂量(1、2、5、10、20μg/ml作用于12名健康成人外周血淋巴细胞培养液诱发染色体畸变,并设空白对照组(生理盐水)。染色体畸变率分别为3.±0.5,9.6±1.1,11.7±1.1,13.6±2.3,18.0±3.0和17.5±2.0％;细胞畸变率为3.1±0.6,9.2±0.6,10.0±0.8,10.8±1.5,11.6±1.8和12.2±14.％。各剂量组与对照组比较差异高度显著(P<0.01)。方差分析,各剂量组间变异的差异高度显著(P<0.01)。相关系数和回归系数也非常显著(P<0.01)。结果表明,东莨菪碱剂量与染色体畸变率和细胞畸变率有线性关系。     

可吸收性医用珊瑚人工骨的致突变性研究

目的评价珊瑚人工骨的遗传毒性。方法采用Ames试验;细胞染色体畸变试验和小鼠骨髓细胞微核试验。结果不同浓度的浸提液加与不加S9mix条件下Ames试验;细胞染色体畸变试验以及微核试验与阴性对照组比较无显著差异,结果为阴性。结论在本试验系统条件下,可吸收性珊瑚人工骨无致突变作用。     

氯丙嗪和氯氮平对小鼠生殖细胞和人淋巴细胞的诱变效应

为探讨氯丙嗪和氯氮平在使用临床治疗剂量时的遗传毒理效应，研究了两药对小鼠生殖细胞和小鼠子代体细胞的影响，以及对人体淋巴细胞姊妹染色单体互换（ＳＣＥ）频率及微核率的影响。结果显示：（１）连续给药５天后第１周两药高、中、低三个剂量组均能引起小鼠精子头部畸形率明显增高，但停药４周后对精子的致畸作用基本消失；（２）两药对小鼠睾丸细胞及子代体细胞的染色体结构畸变率均无明显影响；（３）两药在治疗剂量时对人淋巴细胞的ＳＣＥ频率及微核率无明显影响，治疗前后的自身对照研究亦未见两频率有明显改变；（４）两药的血药浓度与ＳＣＥ频率及微核率之间无量效关系。研究结果提示，两药在临床治疗剂量时对小鼠生殖细胞染色体结构以及对人体遗传物质均无明显损伤作用。     

Shaping ability of the M4 handpiece and Safety Hedstrom Files in simulated root canals

The aim of this study was to assess the shaping ability of the M4 reciprocating handpiece and Safety Hedstrom files in simulated canals. A total of 40 simulated canals of various angles and positions of curvature were prepared with an M4 handpiece using Safety Hedstrom files oriented with the ground, flattened surface towards the inner aspect of the curve. A standard regimen was adopted throughout. Pre- and post-operative longitudinal images of the canals were taken with a video camera and stored and manipulated in a computer with image analysis software. The presence of canal aberrations and the amount and location of resin material removed as a result of preparation were determined from composite images of superimposed pre- and post-operative views. Preparation time varied significantly (P<0.001) between the canal types; overall, 20° canals were prepared more quickly than 40° canals. Zips and elbows were observed in 16 out of the 40 canals with most (11) being created in 40° specimens. Ledges were found in 19 canals and perforations in only 1. There were no significant differences between canal shapes for these aberrations. Excessive removal of material from the inner aspect of the canal at the curve to create a danger zone was found in 20 canals, but only in those with 40° curves. Significant differences in total canal width between the canal types were seen at the zips (P<0.05), elbows (P<0.05) and danger zones (P<0.001). Transportation at the danger zones varied significantly (P<0.001) between canal types. Under the conditions of this study, the M4 handpiece and Safety Hedstrom files created hour-glass preparations in a substantial proportion of canals. In reality, the Safety Hedstrom file with its one flattened surface was ineffective at reducing removal of material along the inner aspect of canal curves in severely curved specimens and clearly has the potential to create strip perforations in teeth.     

Posterior urethral valves in patients with Down syndrome

Renal and urological anomalies in Down syndrome (DS) have received little attention compared with the nephrourological findings described in other chromosomal abnormalities. Renal hypoplasia, hydroureteronephrosis, ureterovesical and ureteropelvic junction obstruction, and vesicoureteral reflux, but not posterior urethral valves, have been associated with DS. We report the occurrence of posterior urethral valves in three male infants with DS at a single institution. All had multiple urological procedures for correction or palliation of obstruction. Children with DS may have an increased risk for developing posterior urethral valves and obstructive uropathy. Furthermore, they may also develop chronic renal failure secondary to posterior urethral valves. Therefore, we suggests that infants with DS be screened with ultrasonography for renal and urological abnormalities early in life and, if abnormal, a contrast voiding cystourethrogram be performed to rule out posterior urethral valves or other bladder or urethral abnormalities. A review of the renal and urological anomalies in DS reported in the literature since 1960 is presented.     

Investigation of aneuploidy induction in mouse oocytes following exposure to vinblastine-sulfate,pyrimethamine, diethylstilbestrol diphosphate,or chloral hydrate

The various causative and mechanistic phenomena associated with aneuploidy induction require considerable investigation to better understand the etiology of chromosome missegregation. We investigated the potential of vinblastine sulfate, pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate to induce numerical and structural chromosome changes in female mouse germ cells. Superovulated ICR mice were administered the compounds either by intraperitoneal injection or oral gavage, and oocytes were collected and processed for cytogenetic analysis 17 hr later. Vinblastine sulfate, administered i.p., induced a significant increase in the frequency of ovulated Ml oocytes and of hyperploid Mll oocytes compared to controls, but did not increase the frequency of structural aberrations. Pyrimethamine, diethylstilbestrol diphosphate, and chloral hydrate did not increase the frequency of numerical or structural chromosome changes in female mouse germ cells. © 1993 Wiley-Liss, Inc.     

Analysis of chromosomes in ascitic fluid cells of ovarian carcinoma

Chromosomes in 1620 metaphases of ascitic fluid cells in 20 cases of ovariancarcinoma were analyzed.The results showed that there were marked structuralaberrations aside from significant increase in chromosomal numerical aberrations(85.2%).In the ascitic fluid cells from 12 patients,15 types of marker chromosomes were found,among which t(6;14)(q21;q24)and t(2;6)(q35;p12)were more frequently noted witha rate of 7.84% and 7.59% respectively,which was significantly higher than that of othermarker chromosomes(P<0.01).The findings suggested that,besides t(6;14)(q21;q24),t(2;6)(q35;p12)may also be a specific marker chromosome of ovarian carcinoma.     

信号核素134Cs诱发体细胞和生殖细胞畸变效应比较研究

对１３４Ｃｓ诱发体细胞和生殖细胞的畸变效应进行了比较研究。方法观察内污染不同放射性活度１３４Ｃｓ时诱发同体骨髓细胞和精原细胞染色体畸变的量效关系，以及同一放射性活度１３４Ｃｓ作用不同时间诱发上述两种细胞的染色体畸变产额。结果研究发现，１３４Ｃｓ内照射诱发的骨髓细胞染色体畸变产额显著高于精原细胞，而其诱发的染色体畸变类型均以染色单体型畸变为主。结论由不同放射性活度１３４Ｃｓ所诱发的染色体畸变产额而言，骨髓细胞要比精原细胞高出１．５～５倍。