Nuclear DNA analysis of genetics of cancer and dysplasia complicating ulcerative colitis

1)最佳切片厚度评估：本研究对23例溃疡性结肠炎患者和10例非结肠炎结直肠癌患者的35份结肠样本，采用细胞计数技术评估石蜡包埋切片的最佳厚度，以测定真实DNA含量。分别从每个样品上切下4、7、10个切片。将这些切片的细胞DNA值与从同一石蜡包埋组织中分离的细胞涂片进行比较。四种方法的模态DNA值相似。相反，DNA含量高于6C值的细胞（多倍体细胞）出现的频率不一致。4、7、10年涂片有多倍体细胞而切片无多倍体细胞的假阴性病例分别为8.6、0、5.7。假阳性检出率分别为14.3、20、25.7、6.3、6.7、18.8。因此，7切片具有较高的敏感性和特异性。我们建议显微分光光度法更能分析溃疡性结肠炎的DNA含量。2)在癌症和发育不良诊断中的应用：采用显微分光光度法测定60例溃疡性结肠炎患者100例标本的DNA含量，其中6例合并癌。在发育不良的30个样本中有23个（77%）表现为非整倍体或多倍体，而在非发育不良的53个样本中有50个（94%）表现为二倍体，差异有统计学意义。多倍体常见于癌症或发育不良患者的非发育不良粘膜。在非发育不良患者中，所有有炎症的样本显示二倍体，而10%没有炎症的样本显示多倍体。多倍体细胞的发生率与发育不良的程度有很好的相关性。从这项研究中，假设微量分光光度法测量DNA含量在溃疡性结肠炎异常增生的评估和诊断中是有用的，并且可以用于筛查高危患者。少

1)Assessment of optimum thickness of the sections : This study assessed the optimum thickness of the paraffin embedded sections to determine the true DNA content with a cytophofometric technique in 35 colonic samples from 23 patients with ulcerative colitis and 10 non-colitic patients with colorectal cancer. The 4 ,7 ,10 sections were cut from each samples. The cellular DNA values of these sections were compared with smears from cells detached from the same paraffin embedded tissue. The modal DNA values of the four methods were similar. On the contrary, the frequency of the cells with DNA content higher than 6C value (polyploid cells) did not coincide. The frequency of false negative cases which had polyploid cells in smears but hadn't in sections was 8.6, 0, 5.7 in 4, 7, 10 respective. The frequency of false positive cases was 14.3, 20, 25.7, but 6.3, 6.7, 18.8 in the inactive specimens. Therefore 7 section showed higher sensitivity and specificity. We suqqest that micro spectrophotom … More etric DNA content in ulcerative colitis is better analized with 7 section.2)Application for cancer and dysplasia diagnpsis : The DNA content was measured by microspectrophotometry from 100 specimens in 60 patients with ulcerative colitis including six complicating carcinoma. In dysplastic 23 (77%) of 30 samples showed aneuploidy or polyploidy, whereas in non-dysplastic tissues 50 (94%) of 53 samples were diploid, the difference being statistically significant. Polyploidy was often observed in the non-dysplastic mucosa of the patients complicating cancer or dysplasia. In non-dysplastic patients all sample with inflammation showed diploidy, however 10% of samples without inflammation showed polyploidy. A good correlation was found between the incidence of polyploid cells and the grade of dyspasia. From this study it was assumed that microspectrophotometric measurement of DNA content is useful in the assessment and siagnosis of dysplasia in ulcerative colitis and can be available in the screening of high-risk patients. Less