金铎逆癌散对甲基苄基亚硝胺诱发大鼠食管癌的影响

目的 观察金铎逆癌散(JDNAS)对甲基苄基亚硝胺(MBNA)诱发大鼠食管癌的影响。方法 120只大鼠MBNA 3 mg/(kg·d)灌胃连续3个月,诱发大鼠食管癌变,根据处理方式不同分为6组,每组20只。空白组仅给予溶剂灌胃;环磷酰胺组给予环磷酰胺5 mg/kg腹腔注射,每周2次;JDNAS高、中、低剂量组给予JDNAS灌胃。3个月后处死大鼠,比较观察各组食管癌变。结果 JDNAS各剂量组对MBNA诱发大鼠食管原位癌及浸润癌均有明显抑制作用。结论 JDNAS能降低食管癌变发生风险,具有潜在抗肿瘤作用,值得进一步研究。     

维生素E预防甲基苄基亚硝胺诱发小鼠前胃癌的研究

以甲基苄基亚硝胺灌喂昆明种小鼠５ｍｇ／ｋｇ体重每周二次共２０次诱发前胃癌，另隔日每周三产欠灌喂维生素Ｅ，Ｅ１组５ｍｇ／只，Ｅ２组２０ｍｇ／只２２周，研讨ＶｉｔＥ的防癌作用。结果表明ＶｉｔＥ 有一定的抗ＮＭＢｚＡ毒性作用并延缓了癌的发生。该研究可为人类食管癌的预防提供参考。     

维生素E预防甲基苄基亚硝胺诱发小鼠前胃癌的研究

以甲基苄基亚硝胺（NMBzA）灌喂昆明种小鼠5mg／kg体重每周二次共20次诱发前胃癌，另隔日每周三次灌喂维生素E（VitE），E1组5mg只、E2组10mg／只E320mg／只至22周，研讨VitE的防癌作用。结果表明VitE有一定的抗NMBzA毒性作用井延缓了癌的发生。发癌率在阳性对照组为73．3％（22／30），E1组为47．4％（18／38），E2组为44．4％（16／36），E3组为61．6％（22／36），E1、E2组与阳性对照组发癌率有显著性差异（P＜0．05），表明维生素E有肯定的防癌作用，但有一定的量效关系。该研究可为人类食管癌的预防提供参考。     

亚硝胺诱发大鼠食管癌survivin mRNA转录水平及与病理变化的关系

 目的探讨甲基苄基亚硝胺（MBNA）诱发食管癌变不同阶段食管组织survivin mRNA转录水平的变化及其与食管组织病理改变的关系。方法Wistar大鼠按3.5 mg/kg体重剂量皮下注射MBNA溶液,每周2次,分别于造模第10、20、30周各处死8只模型大鼠,以同批次正常大鼠为对照,观察食管黏膜大体情况,常规固定切片,并提取新鲜食管组织总RNA,RT-PCR检测survivin mRNA转录水平。结果MBNA诱导10、20及30周时,食管病变呈进行性加重;10、20及30周时survivin mRNA转录水平（0.48±0.16、0.42±0.15、0.46±0.17）差异无统计学意义（P>0.05),但均较正常大鼠（0.24±0.13）显著提高（P<0.01或P<0.05)。结论MBNA诱导大鼠食管癌变过程中,survivin mRNA转录水平在食管早期病变阶段即显著升高且在癌变过程中持续维持较高转录水平,因此抑制survivin mRNA转录是食管癌防治的一个潜在分子靶点。     

香加皮三萜类化合物对甲基苄基亚硝胺诱导的食管癌大鼠调节性T细胞功能的影响

目的：探讨香加皮三萜类化合物（triterpenes compound of cortex periplocae,TCCP）对甲基苄基亚硝胺（N_nitrosomethylbenzylamine,NMBA）诱导的食管癌大鼠CD4^＋CD25^＋调节性T细胞功能的影响。方法：健康雄性F344大鼠40只,随机分为模型组（0.5mg/kg NMBA皮下注射）、治疗组（0.5mg/kg NMBA皮下注射及10mg/kg TCCP肌肉注射）、大豆油对照组（肌肉注射大豆油1ml/kg）和正常对照组,每组10只。各组每周给受试物3次,连续5周。分别在给受试物后第9周和第15周抽取4组大鼠外周血各1ml。用流式细胞仪检测大鼠外周血中CD4^＋T细胞和CD4^＋CD25^＋调节性T细胞（Tr细胞）的水平。另留取血清用ELISA法检测大鼠外周血白细胞介素IL-2、IL-10和转化生长因子TGF_β1的含量。结果：与正常对照组相比,NMBA给药后第9周和第15周,模型组外周血中CD4^＋T细胞比例均显著降低（P均〈0.05）,而CD4^＋CD25^＋Tr细胞比例均显著升高（P均〈0.05）。与同时期模型组比较,TCCP治疗组在给药后第9周和第15周外周血中CD4^＋T细胞比例升高,CD4^＋CD25^＋Tr细胞比例降低,差异均具有统计学意义（P均〈0.05）。NMBA给药后第9周和第15周,模型组大鼠外周血中IL-10、TGF-β1水平显著高于正常对照组（P均〈0.05）,经TCCP治疗后显著下降（P均〈0.05）;大鼠外周血中IL-2水平则呈现与之相反的趋势。结论：NMBA诱导大鼠食管癌后外周血中CD4^＋CD25^＋Tr细胞水平增加,TCCP可以通过抑制CD4^＋CD25^＋Tr细胞活化来纠正食管癌发生、发展过程中所致免疫细胞抑制状态,改善NMBA诱导的食管癌大鼠细胞免疫功能紊乱。     

苦参碱对二乙基亚硝胺诱发大鼠肝癌的预防作用

目的：研究不同剂量苦参碱（MT）对二乙基亚硝胺（DEN）诱发大鼠肝癌的预防阻断作用。方法：采用0．01％的DEN诱发大鼠肝癌90天,同时分别用MT注射液30,15,3mg/kg腹腔注射和3mg/kg灌胃,停止诱癌及给药处理30天后,处死大鼠,观察大鼠肝脏的病理改变,肝表面癌结节数,肝／体重比和血清中丙氨酸氨基转移酶（ALT）,γ-谷氨酰转肽酶（γ－GT）,碱性磷酸酶（ALP）的变化。结果：3mg/kg MT腹腔注射组和灌胃组的体重明显高于模型组,肝表面癌结节数,肝／体重比和血清ALT,γ－GT明显低于模型组和它MT腹腔注射组（P＜0．05）,但腹腔注射的三组中ALP较模型组有不同程度升高,灌胃组则有所下降,结论：MT用于预防阻断DEN诱发大鼠肝癌时,不论剂量大小或给药途径如何,均不能完全阻断DEN诱发大鼠肝癌的发生,但小剂量（3mg/kg)的MT长期口服应用,能保护肝细胞免受损伤,延缓DEN诱发大鼠肝癌的发展。     

柑皮油对二乙基亚硝胺诱发大鼠肝癌前病变的抑制

用二乙基亚硝胺致大鼠肝癌前病变实验模型，研究从鲜柑皮提取的挥发性柑皮油对致癌作用的影响。于大鼠接受ＤＥＮ前１０天起，饲以含５％柑皮油饲料。经两次重复实验，结果显示：肝癌前病变Ｇａｍｍａ－谷氨酰转肽酶阳性肝细胞增生灶的发生类，用柑皮细胞明显少于于单给ＤＮＥ。     

缺硒和补充硒对小鼠肿瘤免疫反应的影响

DBA/2 mice were fed for 16 weeks with Torula yeast-based synthetic diet containing various concentrations of selenium (Se). At 13th week, the mice were immunized with syngenetic L5178 Y lymphoma cells and their specific and non-specific tumor immune responses were examined 3 weeks after immunization. The results indicated that in mice fed with a diet containing 0.007 ppm Se, the serum Se level was extremely low (0.02 micrograms/ml). These Se-deficient mice were unable to elicit normal tumor-specific immune responses. Both the specific proliferation of T cells in MLTC and tumoricidal activity of CTL were very much depressed. In addition, these mice also showed impaired NK and LAK cell activity. The effects of Se supplementation varied depending on the amount of Se given. When 0.170 ppm Se was added to the low Se diet, all the immune parameters examined were restored to the normal level. When 0.567 ppm Se was added, however, the tumor immune responses remained as low as those in Se-deficient mice. This study implies that the prevalence of primary hepatocellular carcinoma in areas where Se is deficient has a profound immunological basis. Se supplementation is obviously indicated for cancer prevention in these areas but the amount of Se supplied is crucial.     

肿瘤杂交细胞阻抑二乙基亚硝胺诱发大鼠肝癌的实验研究

用灭活的肿瘤杂交细胞(融合细胞)免疫二乙基亚硝胺(DEN)诱发肝癌过程中的大鼠做实验。实验分三组:瘤苗免疫组、诱发对照组、空白对照组。实验全程均为18周。实验结果:瘤苗免疫组18只大鼠无一只发生肝癌,而诱发对照组16只大鼠中有10只发生肝癌,其余6只也出现了癌前期病变。结果提示:肿瘤杂交细胞在一定程度上能阻抑或延迟二乙基亚硝胺诱发大鼠肝癌的发生。     

Overexpression of p53 protein in human spontaneous esophageal carcinoma and fetal esophageal carcinoma induced by N-methyl-N-benzylnitrosamine (NMBzA)]

In normal cells, p53 protein is virtually undetectable by immunohistochemical methods. Mutation of p53 gene results in overexpression of the protein and thus levels of p53 detectable by immunohistochemistry may indicate expression of the mutant form of p53. Esophageal cancer (EC) samples obtained from patients who had undergone surgery were assayed for expression in p53 protein. Among 18 primary EC and their adjacent tissues, 7 cases of EC and 5 adjacent tissues overexpression of p53 protein was detected immunohistochemically. In cases with overexpression of the p53 in the adjacent tissues was detected 4 were also positive in the carcinomas. These results suggest that overexpression of p53 protein is a common molecular event in EC and may occur in the early stage of esophageal tumorigenesis. In addition, we found over expression of the p53 protein in the human fetal esophageal carcinoma induced by NMBzA, indicating that p53 gene mutation (s) might have occurred. The results provide further evidence that N-nitrosamine is a causative agent of human esophageal cancer.     

Effect of dietary molybdenum on esophageal carcinogenesis in rats induced by N-methyl-N-benzylnitrosamine

The influence of dietary molybdenum on esophageal carcinogenesis induced by N-methyl-N-benzylnitrosamine (2.5 mg per kg of body weight once a week for 20 wk s.c.) was studied in male F344 rats. The tumor incidence and tumor development in the esophagus were significantly lower in the rats in the high-molybdenum (2 ppm) diet group than in the rats in the low-molybdenum (0.032 ppm) diet group; i.e., 44.4% (0.6 +/- 0.8) and 73.2% (2.2 +/- 2.0), respectively. The molybdenum levels in the esophagus-forestomach, liver, and serum were significantly higher in the high-molybdenum diet group than in the low-molybdenum diet group. Xanthine oxidase activity in the esophagus and forestomach in the high-molybdenum diet group was significantly higher than that in the low-molybdenum diet group, whereas liver and serum xanthine oxidase activities were not significantly different between these two groups. These results suggest that xanthine oxidase in the esophagus plays a significant role in the inhibitory effect of molybdenum on esophageal carcinogenesis.     

Mutational activation of the cellular Harvey ras oncogene in rat esophageal papillomas induced by methylbenzylnitrosamine

Epidemiological studies have demonstrated a strong association between human esophageal cancer and exposure to N-nitroso carcinogens. Esophageal tumors can be induced in experimental animals, especially in rats, by many N-nitroso carcinogens. In the present study, rat esophageal tumors induced by methylbenzylnitrosamine (MBNA) and MBNA-transformed esophageal cell lines were analyzed for activated protooncogenes. DNAs from four Fisher 344 rat esophageal papillomas were examined for their ability to induce morphological transformation of NIH 3T3 cells. One of four esophageal tumors was positive in this assay. Southern blot analysis of this NIH 3T3 transformant revealed that the transforming gene was an activated Ha-ras gene. The activating mutation in the Ha-ras gene was identified by amplifying and then sequencing the first exon of this gene. A GC----AT transition at the second base in codon 12 of the Ha-ras gene was detected. The tumor DNAs from the transfection-negative samples were also amplified, and sequencing analysis of the first exon revealed a GC----AT transition in codon 12. In addition, 14 formalin-fixed and paraffin-embedded rat esophageal papillomas were shown to contain the same mutation in one of the alleles of the Ha-ras gene. In contrast, no point mutation was found in codons 12, 13, and 61 of the Ha-, Ki-, or N-ras genes in MBNA-transformed rat esophageal cell lines. The GC----AT transition detected in the esophageal tumors by DNA sequencing was confirmed by slot blot oligonucleotide hybridization of the polymerase chain reaction-amplified DNAs. The fact that mutated Ha-ras genes were detected in the esophageal papillomas suggests that activation of this gene occurred early in the process of neoplastic progression. The point mutation detected in the Ha-ras gene appears to result from a direct genotoxic effect of MBNA involving formation of the O6-methylguanine adduct. Taken together, these studies suggest that the activation of the Ha-ras gene plays an important role in the induction of esophageal neoplasia in the Fisher 344 rat by MBNA.     

Effects of various dietary staples on esophageal carcinogenesis induced in rats by subcutaneously administered N-nitrosomethylbenzylamine

Previous epidemiologic studies associated large differences of esophageal cancer risk with the nature of the staple diet. In this study, various cereals and dietary staples were fed to inbred BD IX rats for 7 months or longer. N-Nitrosomethylbenzylamine [(MBN) CAS:937-40-6] was given five times subcutaneously between the 45th and 58th day. The percentage of rats with tumors and the mean number of tumors per esophagus were similar when corn, wheat, commercial bird-resistant sorghum, bananas, and polished rice were fed but were strikingly lower when the basis of the diets was millet, red sorghum, brown rice, or potatoes. The number of esophageal tumors was significantly related to the dietary concentration of some minerals and vitamins. Supplementing marginally deficient corn or wheat diets with various combinations of nicotinic acid, riboflavin, zinc, magnesium, molybdenum, and selenium significantly reduced the numbers of esophageal tumors. When the feeding of protective cereals or nutrients was commenced only 150 days after MBN was given, a marked inhibitory effect on the progression of tumors was still observed.     

Influence of dietary selenium on the hepatic and pulmonary enzymes in polychlorobiphenyls-treated rats

One-month-old male Sprague-Dawley rats maintained for 19 weeks on a low selenium diet with or without supplementation of 2.0 ppm selenium were injected intraperitoneally with either 500 mg PCB (Aroclor 1254)/kg body weight or placebo 5 days prior to sacrifice. In addition to aryl hydrocarbon hydroxylase (AHH) activity, PCB treatment also caused a significant increase in hepatic levels of thiobarbituric acid reactants (TBAR), reduced glutathione (GSH), GSH-peroxidase, GSH reductase, glucose-6-phosphate dehydrogenase (G-6-PD), and GSH-S-transferase in rats on the low selenium diet. The non-selenium-dependent form of GSH peroxidase was mainly responsible for the increase of hepatic GSH peroxidase upon PCB treatment. Only the activities of AHH, GSH-S-transferase, and G-6-PD were significantly higher in the liver of PCB-treated rats fed the selenium-supplemented diet. In contrast, except for AHH activity, the lung GSH and related enzymes were not significantly affected by PCB in either of the two dietary groups. The results suggest that dietary selenium deprivation renders the livers of rats more sensitive to PCB effects.     

放疗对食管癌患者免疫功能及预后的影响

目的：观察食管癌患者放疗前后免疫功能的动态变化,探讨与其相关的临床预后因素。方法选取2010年1月至2013年12月在南通大学第二附属医院放疗科就诊的食管癌放疗患者90例,分别于放疗前、放疗结束及放疗后3个月使用流式细胞仪检测患者外周血 T 淋巴细胞亚群及 NK 细胞比例,以30例本院健康体检者外周血人群为对照观察其变化。分析患者放疗前后免疫功能变化与临床特征及预后的关系。结果食管癌患者放疗前外周血 CD4＋、CD8＋、CD4＋／CD8＋比值、NK 细胞百分比分别为28．23％±8．22％、31．79％±7．61％、0．93±0．34、11．37％±4．57％,与对照组（36．03％±9．71％、27．26％±7．70％、1．34±0．27、15．31％±5．13％）相比,差异均有统计学意义（t ＝4．292,P ＝0．000;t ＝2．811,P ＝0．006;t ＝5．894,P ＝0．000;t ＝3．965,P ＝0．000）;放疗前外周血 CD3＋细胞百分比为58．13％±9．46％,与对照组（60．06％±8．67％）相比,差异无统计学意义（t ＝0．998,P ＝0．325）。放疗后3个月免疫指标 CD3＋（59．27％±9．92％）、CD4＋（30．51％±9．04％）、CD8＋（29．79％±6．98％）、NK 细胞（10．62％±4．43％）逐渐恢复到放疗前水平（t ＝0．789,P ＝0．431;t ＝1．769,P ＝0．079;t ＝1．837,P ＝0．068;t ＝1．113,P ＝0．267）。放疗后免疫功能改变（CD4＋、CD8＋、CD4＋／CD8＋、NK 细胞）与是否存在骨髓抑制（t ＝4．050,P ＝0．001;t ＝2．180,P ＝0．015;t ＝2．130,P ＝0．020;t ＝3．520,P ＝0．003）及照射体积大小（t ＝5．170,P ＝0．000;t ＝3．350,P ＝0．026;t ＝8．750,P ＝0．000;t ＝2．490,P ＝0．043）有关。生存分析显示：放疗后3个月免疫功能恢复良好的患者其中位生存时间优于恢复不良者（23个月∶17个月,χ2＝6．820,P ＝0．009）。结论食管癌患者放疗前处于免疫功能抑制状态,放疗实施会进一步加重免疫抑制,其加重程度与骨髓抑制及照射体积相关;放疗后3个月患者免疫功能有所恢复,恢复良好者预后较好。     

Modification of esophageal epithelium DNA in the human fetus by N-nitrosomethylbenzylamine (NMBzA)

Human fetal esophageal epithelium, after being exposed to NMBzA, was found to contain O6-methyldeoxyguanine (O6-MedG), a NMBzA-modified DNA adduct, in tissue DNA by radioimmunoassay and monoclonal antibody, which is highly specific to O6-MedG. The highest level of O6-MedG was 58.83 pMol/mg DNA after adding 5.0 mM NMBzA in vitro. The level of O6-MedG and the concentration of NMBzA followed the dose-effect relationship. O6-MedG could be eliminated from DNA by normal human fetal esophageal epithelium. About 50% of O6-MedG was cleared away in the first 1-2 hours during the post-treatment incubation, which was followed by a slower phase of elimination with 18% left in 24 hours. The results indicate that the human fetal esophageal epithelium can metabolically activate NMBzA in vitro and form O6-MedG, which, as well known, can cause mutagenesis and carcinogenesis and, hence, may most likely be related to the development of human esophageal cancer.     

Influence of preoperative treatment and surgical operation on immune function of patients with esophageal carcinoma.

Multiple immunological parameters, including total lymphocyte count, lymphocyte subpopulations (CD2+, CD19+, CD3+, CD4+ and CD8+), phytohemagglutinin (PHA) response, and natural killer (NK) activity, were measured in 66 patients with previously untreated esophageal carcinoma. The influence of preoperative treatment and/or surgical operation on the immune function were evaluated in 40 patients. The PHA response and NK activity of the patients with esophageal carcinoma were 229 +/- 103 S.I.% and 18.5 +/- 11.9% lysis, respectively, and were significantly depressed as compared with the control. The CD4+/CD8+ ratio, PHA response, and NK activity in stage IV were also significantly depressed compared to that in stages I-III. Preoperative treatment induced significant reductions in the total lymphocyte count (1,994 +/- 644 to 670 +/- 274/mm3), PHA response (219 +/- 77 to 159 +/- 59 S.I.%), and NK activity (19.7 +/- 13.2 to 11.1 +/- 10.3% lysis) as well as a significant gradual decrease in the CD4+/CD8+ ratio (2.09 +/- 1.42 to 0.69 +/- 0.48), while the surgical operation significantly influenced only the total lymphocyte count. This study demonstrates that preoperative treatment induces a more pronounced influence on the immune function than surgical operation alone, in patients with esophageal carcinoma in which the immune function is disturbed prior to these treatments.     

Induction of gastrointestinal tract tumors in rats with N-methyl-N-nitro-N-nitrosoguanidine (MNNG)]

Tumors of the gastrointestinal tract were induced in white non-inbred rats exposed to MNNG in various doses. Gastric tumors appeared in the dosage of 153 mg, with its 2 and 3.3 times increase no change in the frequency of gastric tumors was noted. The frequency of jejunal tumors was higher with increased MNNG dosage.