ENNG诱发犬胃癌癌变过程细胞DNA含量变化的研究

本文利用犬胃癌模型,采用Leitz MPV Ⅱ型显微分光光度计,从细胞水平和分子水平,动态地测定细胞核面积和核DNA含量。结果表明,随犬胃粘膜由正常向癌前、肠型癌发展,核DNA含量呈递增性增加(P<0.01),而弥散型癌细胞DNA含量无明显增加。在肠型癌,DNA倍体类型表现为二倍体逐渐减少,多倍体不断增多,而弥散型癌则表现二倍体型。从中度异型增生到高分化腺癌,细胞核面积逐渐增大,癌细胞核面积与核DNA含量呈显著正相关(r=0.73,P<0.01)。提示测定细胞核DNA含量和核面积,可作为诊断肠型胃癌一种新的定量指标,但不适用于弥散型胃癌。

ENNG致犬胃癌过程中维生素变化与胃粘膜病变的关系

本实验借助ENNG致犬胃癌模型,动态观察血清和胃粘膜细胞水平的维生素A、E、C含量和胃粘膜病理改变。结果表明血清和胃粘膜细胞内维生素 A、E 含量与胃粘膜炎症、萎缩、不典型增生呈明显负相关(P<0.01),血清内维生素C含量与胃粘膜不典型增生呈明显正相关。

ENNG诱发犬实验性胃癌过程中癌前病变的动态观察(摘要)

关于胃癌与其癌前病变的关系,迄今尚未完全阐明.本文采用ENNG对3条狼犬和3条小种猎犬进行诱发胃癌.每天每条犬喂药75mg,连续8～9个月,投给每条狼犬的ENNG总量为17.6g,每条小种猎犬为15.7g.在喂药后,对犬进行定期胃镜检查并在胃窦和胃体进行多点胃粘膜活检.活检粘膜进行常规病理检查和粘液组化染色.部分粘膜电镜观察.另外,对死亡的犬进行尸解,取出胃进行选择性取材,然后进行病理学检查.根据时间和胃粘膜病变的发展顺序,将整个癌变过程分为五个阶段,每个阶段为四个月,其主要病理特征为:1.轻度腺体萎缩和轻度腺颈部增生;2.中至重度腺体萎缩。

致癌物N-乙基-N′-硝基-N-亚硝基胍的合成

为满足实验性胃癌研究的需要,作者采用氰胍为原料,经加成、脱水、乙基化、亚硝化等步骤合成了致癌物ENNG。产品经元素分析、紫外光谱、红外光谱、核磁共振光谱的检测而讧实。此致癌物具有诱癌时问短、所诱发的癌会转移到淋巴结,并且不发生肉瘤等特点。我院肿瘤研究室利用作者所提供的致癌物ENNG复制杂种狗胃癌已获成功。该致癌物的自行合成不仅节约了外汇,更重要的是及时为胃癌基础理论的研究创造了必需的条件。

DNA Cytophotometric Measurements on Canine Stomach Carcinogenesis Induced by N-Ethyl-N'-Nitro-N-Nitrosoguanidine

Measurement of DNA content and nuclear area by microspectrophotometry was performed in gastric carcinogenesis of three adult wolfdogs induced by N-Ethyl-N’-Nitro-N-Nitrosoguanidine (ENNG) . The mean values and standard deviations of nuclear DNA and the lesions in the area of different groups were as follows: normal gastric mucosa 10.03±2.30 (arbitrary unit, AU) and 28.76±5.85 (urn2) , atrophic gastritis 12.04 ±3.34 AU and 28.69±8.02μm^2; mild dysplasia 13.52±3.73 AU and 28.23±8.12μm^2; moderate dysplasia 20.88±4.57 AU and 47.58± 10.74μm^2; severe dysplasia 24.01±4.48 AU and 56.64±12.53μm^2; well-differentiated adenocarcinoma 33.07±9.38 AU and 72.99±15.57μm^2, respectively. The nuclear DNA content and nuclear area showed a significant statistical difference between normal gastric mucosa and gastric carcinoma (P【0.01) . The nuclear area of gastric carcinoma increased with DNA content (r =0.73, P【0.01) , and the distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy was increased in cancer. These findings indicated that DNA ploidy patterns and nuclear area could be a useful index in differentiated carcinoma and precancerous lesions.

DNA CYTOPHOTOMETRIC MEASUREMENTS OF CANINE STOMACH CARCINOGENESIS INDUCED BY N-ETHYL-N'-NITRO-N-NITROSO GUANIDINE

Measurement of DNA content and nuclear area by microspectrophotometry was performed in gastric carcinogenesis of three adult wolfdogs induced by N-ethyl-N’-nitro-N-nitrosoguanidine (ENNG). The mean values and standard deviations of nuclear DNA and area in different groups of lesions were as follows: normal gastric mucosal 0.03±2.30 AU and 28.76±5.85 μm^2; atrophic gastritis 12.04±3.34 AU and 28.69±8.02/μm^2; mild dysplasia 13.52±3.73 AU and 28.23±8.12μm^2; moderate dysplasia 20.88±4.57 AU and 47.58±10.74 μm^2; severe dysplasia 24.01±4.48 AU and 56.64±21.53μm^2; well-differentiated adenocarcinoma 33.07±9.38 AU and 72.99±15.57μm^2, respectively. The nuclear DNA content and nuclear area showed a significant difference statistically between normal gastric mucosa and gastric carcinoma (P【0.01). The nuclear area of gastric carcinoma increased with DNA content (r=0.73, P【0.01), and the distribution patterns of DNA content in the histogram showed that diploidy was decreased and polyploidy was increased in carcinoma. These findings indicate that DNA ploidy patterns and nuclear area could be a useful index in differentiated carcinoma and precancerous lesions.