生物医学测量及控制技术新进展

介绍生物医学测量及控制技术领域中的一些研究进展。     

图像分析DNA含量对判断膀胱移行细胞癌分级和预后的意义

采用IBAS图像分析系统检测37例膀胱移行细胞癌病人的肿瘤细胞DNA含量，其中35例随访18个月至7年（平均5l个月），结果显示DNA含量和AN出现率增加与肿瘤的恶性程度有关（P＜0.01和P＜0.05）；肿瘤复发亦与非整倍体细胞（AN）出现率密切相关，AN出现率小于10％无复发，＜30％5例复发，＞30％9例复发。研究资料表明，图像分析技术测定细胞核的DNA含量对判断膀胱移行细胞癌病人的分级和预后有重要意义。     

不同病理类型胃息肉流式细胞DNA定量研究

应用流式细胞计对５７ 例正常胃粘膜、不同病理类型的胃息肉和胃癌组织作ＤＮＡ 定量分析。正常胃粘膜、炎性息肉、增生性息肉、腺瘤性息肉及胃癌中，ＤＮＡ 非整倍体检出率分别为０％ 、７．７％ 、９．１％ 、３６．４％ 、５８．３％ ；各型胃息肉和胃癌组织的增殖期细胞比率均显著地高于正常胃粘膜组（Ｐ＜ ０．０１）；增生性或炎症性息肉组增殖期细胞比率与胃癌组比较，差异有显著性（Ｐ＜ ０．０５）或非常显著性（Ｐ＜ ０．０１），而腺瘤性息肉组增殖期细胞比率与胃癌组近似（Ｐ＞ ０．０５）。结果表明胃息肉是一种细胞增殖活跃性病变，其中腺瘤性息肉的ＤＮＡ 生物学行为更接近于胃癌，可能容易癌变；应用流式细胞ＤＮＡ 定量分析技术，结合组织病理学诊断，能对胃息肉的预后作出更为确切的判断     

巢湖水有机提取物致鱼红细胞DNA损伤的初步观察

目的　研究巢湖水有机提取物致突变性。方法　单细胞凝胶电泳技术测定鱼红细胞DNA损伤效应。结果　巢湖源水引起慧星细胞的百分率最高 (5 7.2 5 % ) ,滤前水最低 (2 7.6 3% ) ,出厂水经过二次加氯后慧星细胞的百分率有所上升 (4 4 .0 0 % )。结论　巢湖源水具有潜在致突变性 ,经混凝、活性炭吸附及沉淀处理后其DNA损伤作用有所下降 ,但氯化消毒可增加水中有机提取物的DNA损伤作用。     

Investigation of epididymal sperm maturation in the golden hamster

During passage of hamster spermatozoa through the epididymis their maturation is shown to involve changes in the sperm head, midpiece (mitochondria) and tail. The sum of these changes results in a dramatic increase in the fertilizing potential of the spermatozoa. When comparable numbers of spermatozoa from the caput or corpus epididymis were injected into one uterine horn of mature females, following ovulation induction, and spermatozoa from the cauda epididymis were injected into the contralateral horn, no fertilization was observed with caput epididymal spermatozoa, 1.7% of oocytes were fertilized by corpus epiddymal spermatozoa, whereas 79.5% fertilization was obtained with cauda epididymal spermatozoa. Total sperm numbers increased from caput to corpus to cauda [28.3 ± 12.2, 40.6 ±20.8, 1434 ±62 mihon, respectively]. The percentage of progressively motile spermatozoa increased from 27.9 ±6.4 to 33.8 ± 4.8 to 70 ± 10.7 during this passage. Viability, measured by exclusion of the dye, propidium iodide, was significantly less in spermatozoa from the cauda than from the proximal or mid-caput epididymis. The percentage of the live cells that were stained intensely by rhodamine-123 (a measure of mitochondrial membrane potential) increased during epididymal passage from 22.8 ±7.8% in the proximal caput epididymis to 57.2 ± 16.5% in the cauda epididymis. Staining with acridine orange (a measure of DNA packaging in the sperm head) indicated an increase in chromatin condensation in cauda epididymal spermatozoa, when compared to those obtained from the caput or corpus.     

Brain and kidney of progressive multifocal leukoencephalopathy patients contain identical rearrangements of the JC virus promoter/enhancer

The kidneys of six progressive multifocal leukoencephalopathy (PML) patients were examined by PCR amplification for the presence of JC virus. Amplification of three different areas of the viral genome from multiple samples of each kidney revealed three that were positive for the virus. The use of a PCR-based typing assay on all tissue samples, and cloned sequences from the viral coding region from each positive kidney showed that the same viral genome was present in the kidney as in the brain of the patient. Regulatory region clones all had the archetypal promoter/enhancer structure. However, when PCR fragments from the regulatory region were digested with a restriction enzyme which cuts in region D, the region most often deleted in PML-type promoters, a low level of undigested DNA remained. This DNA refractory to digestion had a rearranged sequence identical to that of the unique rearranged promoter in the brain of each patient. © 1994 Wiley-Liss, Inc.     

27例肾腺癌的图象细胞仪定量分析

测定２７例肾腺癌的ＤＮＡ含量，并联系肿瘤的分级等部分形态学指标，对透明细胞型和颗粒细胞型肿瘤进行比较分析。发现：透明细胞型肾腺癌的分化一般较好，ＤＮＡ以二倍体为主，预后相对较好；而颗粒细胞型肾腺癌的分化较差，ＤＮＡ以非二倍体为主，其预后较差。     

16株假单胞菌DNA的G＋C百分含量测定

采用改良的热变性温度法，将DNA升温及恒温处理与紫外吸收值的测定分两步进行，检测3株标准菌株和16株假单胞菌DNA的G Cmol% 含量。结果表明，14株假单胞菌与其相应标准菌种的DNAG＋Cmol%含量基本一致，与其生物学性状亦相符；另2株DNA的G＋Cmol%含量与其生物学性状不符，其分类学位置尚待探讨。     

Cerivastatin inhibits fetal calf serunvinduced DNA synthesis in cultured rat mesangial cells

SUMMARY: Inhibition of mevalonate synthesis by several statins has been shown to suppress DNA synthesis in glomerular mesangial cells. In the present study, we investigated the effect of a new statin, cerivastatin, on fetal calf serum (FCS)-induced DNA synthesis of cultured rat mesangial cells. Cultured rat mesangial cells were stimulated by 10% FCS in the presence or absence of cerivastatin and mevalonate. 5-bromo-2-deoxyuridine (BrdU) incorporation was used to assess DNA synthesis. the present study showed that 10% FCS caused marked stimulation of DNA synthesis in the mesangial cells. Cerivastatin inhibited FCS-stimulated BrdU incorporation in a dose-dependent manner. IC₅₀ was approximately 1 umol/L. Exogenous mevalonate, farnesyl pyrophosphate and geranylgeranyl pyrophosphate significantly prevented the inhibitory effect of cerivastatin on DNA replication. It appears that cerivastatin, by inhibiting the synthesis of mevalonate, may suppress DNA synthesis in the mesangial cells.     

Andrology: Application of different in-situ hybridization detection methods for human sperm analysis

The detection of some types of aneuploidy in human spermatozoacan be based on the use of the fluorescence in-situ hybridizationtechnique (FISH). One of the crucial steps for FISH is to achievea proper decondensation and denaturation of the DNA in the specimen,so as to obtain efficient hybridization results. However, afterDNA decondensation the morphology of sperm heads is partly distortedand the majority of the tails is lost. This situation leadsto problems in the distinction between disomic and diploid spermatozoa,as well as between abnormal spermatozoa and somatic cells. Double-and triple-target FISH can partly solve this discriminationproblem. To improve these procedures we adapted the steps ofdecondensation and visualization of the single sperm cells.Firstly, DNA decondensation with 25 mM dithiothreitol in 1 MTris at pH 9.5 resulted in sperm cells with intact morphologyof both the head and the tail, and allowed efficient single-,double- and triple-target ISH to be performed. Secondly, weapplied a novel detection method, based on enzyme immunocyto-chemicalreactions, with coloured precipitation products. Thirdly, thisISH procedure was combined with Diff-Quik staining and bright-fieldmicroscopy. This absorption method has the advantage of a permanentsignal, and the adapted cytoplasmic staining of the sperm plasmamembrane allows the visualization of the outline of the singlespermatozoon. Using this approach, therefore, it is possibleto discriminate between disomic, diploid and abnormal spermatozoa,somatic cells and spermatozoa that overlap, because the morphologyof the cells is not distorted and the tails of the spermatozoaare intact and properly visualized.