Effect of using RNA interference to alter iNOS gene expression on the proliferation of tongue squamous cell carcinoma cell line Tca8113

This study used RNA interference (RNAi) to explore the effect of NO and inducible nitric oxide synthase (iNOS) on apoptosis and proliferation in the tongue squamous carcinoma cell line Tca8113. Tca8113 cells were transfected with the plasmid pGenesil-1, which expresses iNOS short hairpin RNA (shRNA), or the negative control plasmid pSilencer-HK, and the transfected cells were compared with untransfected cells. The expression of iNOS was detected by histochemistry, and apoptosis was detected by flow cytometry. The expression of iNOS was significantly lower in the pSilencer-iNOS group than in the pSilencer-HK and empty control groups. The apoptosis rate was significantly higher in the pSilencer-iNOS group than in the pSilencer-HK and empty control groups. Growth monitoring showed that proliferation was also inhibited in cells transfected with pSilencer-iNOS. RNAi gene silencing decreased iNOS gene expression, induced apoptosis, and suppressed proliferation in Tca8113 cells.     

槟榔碱对血管内皮细胞增殖和分泌NO的影响

目的：观察去除槟榔碱干预后血管内皮细胞（EC）增殖和分泌一氧化氮（NO）的变化。方法：采用MTT法检测去除槟榔碱干预后的EC存活率，硝酸还原酶法检测EC分泌NO量。结果：30μg／ml～90μg／ml槟榔碱干预EC 24h，去除刺激并继续孵育48h，EC的增殖能力可恢复，且分泌NO增多（p〈0．05）；但120μg／ml槟榔碱干预24h、30μg／ml～120μg／ml槟榔碱干预48h并继续孵育48h，EC的增殖能力难以恢复（P〈0．05）。结论：去除低浓度、短时间槟榔碱干预后EC增殖能力的恢复可能与具有自我保护效应的NO分泌量增加有关。     

唾液腺腺癌VEGF和NOS的表达与癌细胞增殖关系的研究

目的:研究唾液腺腺癌组织血管内皮生长因子(VEGF)、诱导型一氧化氮合酶(iNOS)、内皮型一氧化氮合酶(eNOS)的表达与癌细胞增殖的相关性。方法:应用免疫组化方法检测47例唾液腺腺癌手术切除标本VEGF、iNOS、eNOS和增殖细胞核抗原(PCNA)的分布及表达。结果:①30例(63.83%)唾液腺腺癌组织表达VEGF,31例(65.96%)表达iNOS;33例(70.21%)表达eNOS;②VEGF与iNOS的表达具有明显相关性,VEGF与eNOS的表达无明显相关性;③表达VEGF的唾液腺腺癌PCNA标记指数(PLI)明显高于不表达VEGF的唾液腺腺癌;表达iNOS的唾液腺腺癌PLI明显高于不表达iNOS的唾液腺腺癌。表达eNOS的唾液腺腺癌PLI与不表达eNOS的唾液腺腺癌无显著差异(P>O.05)。结论:①VEGF与iNOS的表达具有明显相关性,说明iNOS在VEGF的生成和发挥作用过程中起重要作用;②PLI随着VEGF和iNOS表达的增加而增加;说明两者对唾液腺腺癌细胞增殖具有促进作用。     

S-甲基异硫脲治疗颞下颌关节骨关节病的动物实验研究

目的探讨S- 甲基异硫脲（SMT）对黑山羊颞下颌关节骨关节病的治疗效果。方法选取9只纯种黑山羊，随机分为正常对照组、实验对照组和实验组，每组3只。对实验组和实验对照组黑山羊双侧颞下颌关节上腔一次性注射胶原酶，诱导骨关节病病变。正常对照组不作任何治疗；实验对照组为对实验动物关节上腔注射生理盐水0.5 mL；实验组为对实验动物关节上腔注射SMT 0.5 mL。处死动物后在光镜和扫描电镜下观察颞下颌关节的变化。结果在光镜和扫描电镜下观察，实验对照组髁突、关节盘、关节凹表现为骨关节病变化；实验组中则表现出不同程度的改善。结论通过3个月的观察和研究，发现SMT关节上腔重复注射能抑制颞下颌关节骨关节病的发展，其作用机制可能与SMT抑制一氧化氮合酶在关节局部产生过多的一氧化氮有关。     

Effectiveness of scaling and root planing versus modified Widman flap on nitric oxide synthase and arginase activity in patients with chronic periodontitis

BACKGROUND: Nitric oxide (NO) is synthesized from the conversion of L-arginine to L-citrulline by NO synthase (NOS). Arginase, which is an arginine-depleting enzyme, can compete with NOS for the common substrate L-arginine and thus inhibit NO production. OBJECTIVES: In the present study, we aimed to examine the correlation between the arginase and NOS activity in patients with chronic periodontitis and to compare the effects of scaling and root planing and modified Widman flap procedures on enzyme activity. MATERIAL AND METHODS: The study included 13 patients diagnosed with chronic periodontitis. Using a split-mouth design, the defects showing>or=7 mm of attachment loss were treated either with scaling and root planing or with modified Widman flap. Gingival biopsies from both sites were obtained at baseline and 2 months after periodontal treatment. Immunohistochemical staining was performed for evaluating NOS expression and specific arginase activity was determined spectrophotometrically. RESULTS: Although inflamed periodontal tissues demonstrated a strong inducible NOS (iNOS) expression at baseline, immunostaining decreased after periodontal treatment. iNOS expression intensity and the number of inflammatory cells showing iNOS expression were found to be higher in the scaling and root planing group compared to the modified Widman flap group. The specific activity of arginase was measured as 0.18+/-0.07 IU/mg protein in the modified Widman flap group and 0.25+/-0.11 IU/mg protein in the scaling and root planing group at baseline. After periodontal therapy, the enzyme level was increased to 0.68+/-0.14 IU/mg protein in the modified Widman flap and to 1.10+/-0.23 IU/mg protein in the scaling and root planing group. CONCLUSION: This study was the first report of evaluating the involvement of the arginine-NO pathway in chronic periodontitis and this might be considered to be of value in understanding the periodontal disease mechanisms.     

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。     

Effect of vitamin E on periodontitis: Evidence and proposed mechanisms of action

BackgroundPeriodontitis is a noncommunicable inflammatory disease of the soft tissue and bone surrounding the teeth in the jaw, which affects susceptible individuals with poor oral hygiene. A growing interest has been seen in the use of dietary supplements and natural products for the treatment and prevention of periodontitis. Vitamin E consists of two major groups, namely tocopherols and tocotrienols, which are botanical lipophilic compounds with excellent anti-inflammatory and antioxidant properties.HighlightThis review aimed to summarize the preclinical and clinical findings on the effects of vitamin E on periodontitis. The current literature suggests that vitamin E could improve the periodontal status by correcting redox status imbalance, reducing inflammatory responses, and promoting wound healing, thus highlighting the potential of vitamin E in the management of periodontitis.ConclusionDirect evidence for the use of vitamin E supplementation or treatment of periodontitis in humans is still limited. More well-designed and controlled studies are required to ascertain its effectiveness.     

PyV-mT-induced parotid gland hyperplasia as detected by altered lectin reactivity is not modulated by inducible nitric oxide deficiency

The parotid gland was one of the first organs recognised to be sensitive to the transforming effects of polyomavirus. This study examines parotid gland pathology in mice expressing the polyomavirus middle T (PyV-mT) under the control of the mouse mammary tumour virus long terminal repeat (MMTV-LTR) to (1) demonstrate the utility of this model for studying premalignant disease; (2) identify early lesions by lectin staining and (3) determine effects of the inducible nitric oxide synthase (iNOS) in modulating tumorigenesis. The middle T oncogene is expressed in the parotid glands in addition to the mammary glands and results in the formation of parotid hyperplasias in 100% of transgenic female mice. These hyperplasias have the features of intraepithelial neoplasia including hypertrophic cells with prominent nucleoli and abnormal mitoses. Focal areas of parotid hyperplasia can be identified using peanut agglutinin (PNA), a lectin that recognises the tumour associated T antigen. In contrast to normal parotid gland, areas of hyperplasia do not bind PNA. Mice deficient in iNOS, an enzyme implicated in the promotion of tumorigenesis, were bred into the PyV-mT model. The loss of iNOS did not impact on the number or size of parotid gland hyperplasias, suggesting that NO produced by this enzyme is not a key regulator of PyV-mT-induced parotid gland hyperplasia. The consistent development of parotid hyperplasias in PyV-mT mice and clear identification of these lesions by loss of PNA lectin reactivity provides a useful model for studying early molecular changes in parotid tumorigenesis.     

Study on the effects of mechanical pressure to the ultrastructure and secretion ability of mandibular condylar chondrocytes

During mandibular movement, condyle is subjected to repetitive compression and the mandibular condylar chondrocytes (MCCs) can detect and respond to this biomechanical environment by altering their metabolism. The present study was undertaken to investigate the effects of pressure to the ultrastructure, aggrecan synthesis, nitric oxide (NO) and prostaglandin F(1)alpha(PGF(1)alpha) secretion in MCCs. In vitro cultured rabbit MCCs were incubated and pressed under continuous pressure of 90kPa for 60min and 360min by hydraulic pressure controlled cellular strain unit. The ultrastructure, aggrecan mRNA expression, activity of nitric oxide synthase (NOS) and PGF(1)alpha secretion were investigated. Besides, nitric oxide inhibitor was used together with pressure to investigate the role of NO in mechanical effects. The appearance of MCC on TEM showed that after been pressed under 90kPa for 60min, the cellular processes became elongated and voluminous, together with aggrecan mRNA increasing. Under 90kPa for 360min, some of the cells showed distinct sign of apotosis and the aggrecan mRNA decreased. Pressure of 90kPa could cause increase of NOS activity and decrease of PGF(1)alpha composition. Inhibitor experiments indicated that pressure-induced upregulation of aggrecan mRNA and inhibition of PGF(1)alpha synthesis was partly mediated by NO. Continuous pressure could cause changes on the ultrastructure and function of MCC, as well as up-regulation of aggrecan synthesis, increase of NO secretion and decrease of PGF(1)alpha composition. NO was the upstream molecule, which mediated the response of aggrecan and PGF(1)alpha to mechanical pressure.     

修复性牙本质形成过程中一氧化氮的功能——I:一氧化氮合成酶的表达

目的:观察大白鼠磨牙窝洞制备后,修复性牙本质形成过程中一氧化氮合酶NOS的表达。方法:大白鼠磨牙窝洞制备后制作冰冻切片,免疫组化染色观察成牙本质细胞与牙髓细胞中一氧化氮合酶的表达。结果:正常大白鼠磨牙中,内皮型一氧化氮合酶(eNOS)呈阳性反应,而诱导型一氧化氮合酶(iNOS)呈阴性反应。牙体制备后即刻,损伤的成牙本质细胞中两种一氧化氮合酶均呈弱阳性反应;制备1d后,在牙髓牙本质界中浸润的中性粒细胞中表现为诱导型一氧化氮合酶(iNOS)的强阳性反应,并在制备3d后,扩展至全部牙髓细胞;同阶段,内皮型一氧化氮合酶(eNOS)在上述细胞中,均呈弱阳性反应。制备7d后,修复性牙本质深部成牙本质细胞中,诱导型一氧化氮合酶(iN-OS)呈阴性反应,而内皮型一氧化氮合酶(eNOS)呈阳性反应。结论:一氧化氮参与了修复性牙本质形成过程中成牙本质细胞的分化与功能调节。