金地鼠颊囊癌变过程中p65蛋白的表达研究

目的探讨核转录因子-κB家族成员中的一个重要亚基p6 5在DMBA诱导的金地鼠颊囊鳞状细胞癌发生过程中的表达及意义。方法建立金地鼠颊囊癌变的动物模型。采用Westernblot法检测12组配对金地鼠正常颊粘膜、上皮单纯增生、上皮异常增生和鳞状细胞癌组织所提取的核蛋白中p6 5的表达差异。结果在正常颊粘膜和上皮单纯增生组织中未见明显的p6 5表达,且两者相比无显著性差异(P >0 .0 5 )。随着上皮异常增生的出现,p6 5表达增强,较正常组和单纯增生组均有显著性差异(P <0 .0 1)。在鳞状细胞癌组织中,p6 5的表达进一步增强,与正常组和异常增生组相比均有显著性差异(P <0 .0 1)。结论p6 5在金地鼠颊囊鳞状细胞癌发生、发展过程中被激活。P6 5在金地鼠颊囊癌变过程中的表达异常,尤其是在上皮异常增生阶段的表达水平上调,可能是口腔粘膜上皮癌变过程中的一个早期事件。     

P21和P185在颊粘膜上皮良性和恶性病变中的表达及意义

采用免疫组化ABC法检测P21和P185在正常颊粘膜上皮，慢性非特异性炎症病变、镤状细胞癌及其癌旁组织中的表达，并进行图像分析，结果显示，P21和P185在鳞癌和部分癌旁组织中的表达明显高于正常颊粘膜上皮和炎症病变，二者具有明显的相关性，提示P21和P18与颊粘膜上皮恶变有相关性。     

实验性口腔癌发生过程中增殖细胞核抗原表达的研究

目的：利用金黄地鼠颊癌模型，探讨口腔癌发生过程中增殖细胞核抗原（ＰＣＮＡ）表达变化及其规律。方法：０．５％二甲基苯并蒽（ＤＭＢＡ）丙酮液处理地鼠颊粘膜，每周３次，３、６、９和１２周分批处死动物；对照组不处理。利用抗ＰＣＮＡ单克隆抗体，免疫组化方法（ＬＳＡＢ）检测ＰＣＮＡ的表达情况。结果：正常地鼠颊粘膜ＰＣＮＡ表达主要位于基底层和少数棘层细胞，３周单纯增生类似正常，６￣９周上皮呈不同程度异常增生，Ｐ     

激素和吸烟对颊粘膜细胞角蛋白的表达无影响

吸烟是口腔鳞癌的病因之一,有人把细胞角蛋白(cytokeratin)作为口腔癌前病变和口腔癌的上皮分化标志。已发现雌激素可影响颊粘膜上皮,培养的人子宫颈阴道部的上皮细胞中发现激素可调节细胞角蛋白的表达。这种上皮在体外与颊粘膜上皮非常相似。本研究的目的是评价吸烟和激素变化是否对颊粘膜的细胞角蛋白表达有影响。     

实验性口腔癌发生过程中增殖细胞核抗原表达的研究

目的：利用金黄地鼠颊癌模型,探讨口腔癌发生过程中增殖细胞核抗原（ＰＣＮＡ）表达变化及其规律。方法：０．５％二甲基苯并蒽（ＤＭＢＡ）丙酮液处理地鼠颊粘膜,每周３次,３、６、９和１２周分批处死动物;对照组不处理。利用抗ＰＣＮＡ单克隆抗体,免疫组化方法（ＬＳＡＢ）检测ＰＣＮＡ的表达情况。结果：正常地鼠颊粘膜ＰＣＮＡ表达主要位于基底层和少数棘层细胞,３周单纯增生类似正常,６～９周上皮呈不同程度异常增生,ＰＣＮＡ表达扩展至棘层,甚至全层,与异常增生程度呈正相关;１２周鳞癌形成时,ＰＣＮＡ表达明显增加,且见明显异质性。结论：ＤＭＢＡ诱导地鼠颊癌发生过程中存在ＰＣＮＡ异常表达,且与癌变进展有关,提示ＰＣＮＡ表达可作为口腔癌变监测的生物学标志之一。     

核转录因子-κB在金地鼠颊囊癌变过程中的表达研究

目的　探讨核转录因子-κB家族成员的重要亚基p65及其抑制蛋白IκBα在金地鼠颊囊鳞癌发生过程中的 表达及意义。方法　建立金地鼠颊囊癌变的动物模型,采用Western blot法检测金地鼠正常颊黏膜、上皮单纯增生 黏膜、上皮异常增生黏膜和鳞癌组织所提取的核蛋白中p65的表达差异;采用SABC免疫组织化学法检测在金地鼠 颊黏膜正常上皮、上皮单纯增生、上皮异常增生、鳞状细胞癌中IκBα的表达变化。结果　正常黏膜和上皮单纯增生 黏膜中,p65表达很弱,但普遍存在IκBα的表达,该表达多局限于黏膜基底层和棘层底部细胞的胞浆中。随着上皮 异常增生的出现,p65表达增强,与正常黏膜和单纯增生黏膜相比有统计学意义(P<0.01),而IκBα表达则显著下 降(P<0.05)。鳞癌组织中p65的表达显著高于正常黏膜和异常增生黏膜(P<0.01),IκBα的表达显著升高,明显 高于上皮异常增生黏膜(P<0.01),甚至超过正常水平(P<0.01)。结论　p65在金地鼠颊囊鳞癌发生、发展过程中 被激活。p65和IκBα在金地鼠颊囊癌变过程中的表达异常,上皮异常增生阶段p65的表达上调而IκBα的表达下调, 可能是口腔黏膜上皮癌变过程中的早期事件,可作为口腔早期癌变监测的生物学指标。     

扁平苔藓与癌前病变──形态计量学研究

用Ｚｅｉｓｓ ＶＩＤＡＳ图象分析系统,对口腔颊部粘膜扁平苔藓、白斑、慢性非特异性炎症、鳞癌以及正常颊粘膜上皮的基底层及棘层细胞、细胞核的体积、直径及细胞核和细胞比值进行了系统的观察。证实形态计量学方法是一种可以针扁平苔藓与其它病变有效区分开的组织病理学方法。     

丙烯腈对鼠类颊粘膜早期损害的实验研究

目的观察化工产品丙烯腈及酒精对大小鼠颊粘膜的影响。方法将大小鼠分别分组，给予不同剂量的丙烯腈或丙烯腈加酒精，染毒１３周后，取颊粘膜用光镜和透射电镜观察其结构。结果丙烯腈对鼠类颊粘膜有直接毒性，并可致癌前样病变——粘膜上皮的不典型增生，如上皮不全角化、细胞核肿大变形、桥粒半桥粒减少、基膜断裂和线粒体肿胀变性等，其程度与所给剂量成正比，而酒精可加重其病变。结论颊粘膜可作为一个窗口来观察丙烯腈等有毒物对肌体的慢性毒害及癌前损害，电镜有助于疾病的早期诊断     

鼠口腔正角化与不全角化上皮的光镜和扫描电镜的对照研究

鼠口腔颊粘膜、龈沟、舌背乳头间区上皮为不全角化上皮,而附着(?)和硬腭粘膜为致密的正角化上皮。本文作者对成年鼠的正角化和不全角化上皮进行了光镜和扫描电镜观察,并将其结果作了比较。扫描电镜标本取自15只年龄在3～5个月的成年雄鼠,光镜标本取自10只成年雄鼠。部位如下:1)左右侧颊粘膜(带有下面肌层)。2)第一磨牙至第三磨牙的左右侧下颌骨粘膜,包括颊侧舌侧沟。3)包括第二磨牙区的硬腭和颊沟的左右侧上颌骨。采用常规扫描电镜狃光镜标本制作方法,染色观察。     

微核计数的方法在口腔医学中的应用

微核计数是一种简单、快速、在细胞学水平筛查染色体损伤的方法,近年来被用于口腔颊粘膜脱落细胞的现察。本文介绍了微核形成的机理、口腔颊粘膜脱落细胞微核计数的方法及其在口腔医学中的应用。烟草及其混合物与口腔癌前病变及口腔癌的发生密切相关,烟草使用者的微核计数明显高于对照组。化学预防制剂用于癌前病变患者,其微核计数有明显下降。微核计数还可预测口腔癌患者对放疗的敏感性。它在有关癌前病变及癌症的研究中有广泛的应用前景。     

Effects of nicotine and tobacco-specific nitrosamines on hamster cheek pouch and gastric mucosa

Fifty-two hamsters were divided into 6 groups and their cheek pouches treated with either 0.01% NNN, 0.01% NNN and 6% nicotine, 0.01%. NNK, 0.01% NNK and 6% nicotine, 6%i nicotine, or sesame oil. After painting each pouch 3 times per week for 13 months, the animals were killed and specimens from the cheek pouch and forestomach examined. Cheek pouch epithelium showed more frequent histologic changes, including hyperplasia, hyperkeratosis and, in one animal, moderate dysplasia, when nicotine was combined with NNN than after treatment with NNN (or nicotine) alone. There was a higher frequency of hyperplasia with hyperkeratosis in the forestomach when nicotine was combined with NNK than following NNK, or nicotine treatment alone, and squamous cell papillomas were evident in animals treated with both NNK and nicotine. These results suggest that in mucosal tissues nicotine may enhance the effect of weak carcinogens such as the nitrosamines.     

Changes in microcirculation after local application of sex hormones

The invariable occurrence of gingivitis in pregnancy initiated the present study of the local effects of sex hormones, deposited in the tissues. Vital microscopic studies of hamster's cheek pouch disclosed varying degrees of tissue injury manifested by mierocirculatory disturbances and related to the type and concentration of the hormones Gonadex®, Ovex-B®, Stilbol® and Progesteron®. There were changes in blood flow, the behaviour of cells in the vessels and in the vessel walls and in the perivascular mast cells. Some of these abnormalities were reversible whereas others were permanent and severe.     

Use of the Syrian golden hamster for the induction of intraoral abscesses by sutures contaminated with human subgingival plaque

Analysis of normal oral flora in 150 cheek pouches of hamsters ( Mesocricetus auratus ) defined the microbial working environment and demonstrated the absence of human oral black-pigmented bacteria. Silk sutures saturated with Porphyromonas gingivalis, Prevotella intermedia or subgingival plaque were used to close wounds made in hamster's cheek pouches. Abscesses were formed when sutures had solitary P. gingivalis or other bacteria mixed with P. gingivalis or when P. intermedia was mixed with other bacteria besides P. gingivalis. A concentration of black-pigmented bacteria emanating from 3×10⁵ colony-forming units/inoculum was required for abscess formation. Six abscesses (14.3%) were developed in association with the presence of other odontopathic bacteria, primarily Fusobacterium nucleatum and Actinomyces viscosus. The hamster cheek pouch with iatrogenic wounds closed with plaque-impregnated sutures is a novel and effective model to study the pathology of wound infections and virulence of human subgingival organisms.     

实验性口腔癌的端粒行为异常研究

目的：探讨ＤＭＢＡ诱导金黄地鼠颊囊癌变过程中端粒长度动态变化。方法：Ｙｏｕｔｈｅｒｎ杂交技术分析金黄地鼠颊囊癌变组织端粒ＤＮＡ序列长度。结果：金黄地鼠颊囊癌变过程中,癌变侧颊囊粘膜组织端粒长度较自身正常对照侧明显缩短,尤以诱癌后期缩短速率最快。结论：端粒长度缩短在癌变早期显著。     

Morphological alterations in the epithelium of the oral mucosa of rats (Rattus norvegicus) submitted to long-term systemic nicotine treatment

Smoking is considered to be the most albeit preventable cause of diseases and premature deaths in the history of mankind. The local action of tobacco on the oral mucosa can cause precancerous and cancerous lesions. However, there is not enough evidence to establish all the systemic effects caused by nicotine on the organism. Thus, the aim of the present study was to characterize the cellular changes of the cheek mucosa of rats submitted to long-term systemic nicotine treatment. Twenty male rats were divided into two experimental groups: a nicotine group and a control group, each consisting of 10 animals. The nicotine group was injected daily with 0.250 mg of nicotine per 100 g of body weight. All animals received a solid diet and water ad libitum. After 90 days of treatment, all animals were weighed and sacrificed. Samples of cheek mucosa were collected for light and transmission electron microscopy. The results revealed oral epithelium containing atypical cells that were characterized by atrophy, cell membrane disorganization and tissue damage. It was concluded that systemic administration of nicotine damaged the cellular integrity of the oral mucosa, impairing tissue function and predisposing the tissue to the action of different pathogenic agents and also to that of other carcinogenic substances present in tobacco.     

The mechanisms of antioxidant against inflammatory lesion in animal oral mucosa. II. A study of glutathione peroxidase]

In order to understand the mechanisms of superoxide dismutase (SOD) against inflammatory lesion in hamster cheek pouch, glutathione peroxidase (GPx) activity in the cheek pouch mucosa was assayed in different time. The efficacy of GPx scavenging lipid peroxide was also measured. In the SOD group GPx activity decreased significantly in the early stage (8 h). But the level of lipid peroxide in the SOD group not increase at the same time. The results of the model group were contrary. It was implied that exigenous SOD scavenged lipid peroxide in the oral mucosa sufficiently in stead of GPx.     

实验性口腔粘膜炎性损害的抗氧化防治机理研究Ⅱ.口腔粘膜谷胱甘肽过氧化物酶的变化规律

研究不同时段鼠颊囊组织中谷胱甘肽过氧化物酶（GP*）的活性变化规律。并分析了GPx清除脂质过氧化产物丙二醛（MDA）的作用效能。结果显示：SOD组早期（8h)GPx活性明显下降，但MDA含量却未增高；模型组8h-3d时GPx活性正常，但8h时GPx清除MDA的效能却明显降低，上述结果提示；外源性SOD可能具有代替CPx清除，减轻脂质过氧化损伤口腔粘膜的作用。     

Identification of telomerase activity in the experimental carcinogenesis of oral cavity]

OBJECTIVE: Telomerase is a ribonucleoprotein enzyme which synthesizes telomere DNA repeat sequences and maintain stably telomere length. The activity of telomerase may be necessary for the growth of immortalized cells overcoming cellular senescence. The researches have shown that telomerase activities are associated with most cancers. The purpose of the study is to detect the development of telomerase activity during golden hamster cheek pouch carcinogenesis induced by DMBA. METHODS: First, 52 golden hamsters were divided into 2 groups. Four of them were not done any special treatment and were killed after 3 days. The others were covered with DMBA on the surface of cheek pouch on one side in order to induce carcinogenesis, the other side of cheek pouch was treated as the control. Then, the 48 golden hamsters were divided into 4 groups and were killed in 7, 10, 14 and 20 weeks. The telomeric repeat amplification protocol (TRAP) based on PCR and ELISA was used to analysis the activity of telomerase. RESULTS: 1. The expression of telomerase activity existed in normal cheek pouch mucosa of golden hamsters, which meant that telomerase played an important role on controlling cell proliferation. 2. The level of telomerase activity gradually increased while hyperplasia and dysplasia was observed in the cheek pouch mucosa covered with DMBA. It reached its top at a later premalignant period and gradually decreased after that. 3. There was negative correlation between the degree the telomere length was shortened and the activity of telomerase (r = -0.9654), and there was positive correlation between the reduced rate of telomere length and the activity of telomerase (r = 0.9471). CONCLUSION: The activity of telomerase is one of important factors that can effect the stability of telomere length and plays a crucial role in the progression of oral cancer. So the activity of telomerase is an early molecular marker of carcinogenesis.     

AgNOR mark epithelial foci in malignant transformation in hamster cheek pouch carcinogenesis

Hamster cheek pouch mucosa is an accepted model of oral carcinogenesis. We herein examined the value of morphometric evaluation of silver-stained nucleolar organizer regions (AgNOR) in the detection of epithelial foci in malignant transformation following dimethyl-1, 2-benzanthracene-induced carcinogenesis of hamster cheek pouch. AgNOR-related parameters were analyzed at different stages of the process of carcinogenesis (control epithelium, epithelium with no unusual microscopic features, "dysplastic" epithelium, exophytic and endophytic carcinomas). Morphometric evaluation of AgNOR revealed incipient cellular alterations which were not evident in routine preparations and contributed to the characterization of different stages of carcinogenesis in this model.     

诱导型一氧化氮合酶抑制剂对地鼠颊囊癌变的干预作用

目的研究一氧化氮(NO)在肿瘤发生发展过程中所起的作用,探讨一氧化氮合酶(NOS)抑制剂对地鼠颊囊粘膜癌变所起的干预作用。方法90只金黄地鼠分为实验1组(TI组)、实验2组(T2组)和空白对照组(C组),利用二甲基苯并葱(DMBA)诱导T1,T2组地鼠颊囊癌变,并在T2组给予一氧化氮合酶抑制剂I,.硝基精氨酸甲醋( L, NAME),观察T1和T2组颊囊豁膜癌变中病理改变,SABC免疫组化法检测iNOS,VEGF,珊因子动态表达,硝酸还原酶法测定NO量的变化。结果】)MBA诱导T1组和72组颊囊薪膜癌变率的差异有统计学意义,P < O.OS,iNOS, VEGF阳性表达增加,NO量和微血管密度不断增加。结论NO在地鼠颊囊癌的发生发展中起促进作用,而G NAME起干预作用。