五倍子提取物对牙龈卟啉菌内毒素介导白介素-1β活性的影响

目的：研究五倍子提取物对牙龈卟啉菌内毒素介导白介素—lβ活性的影响。方法：采用人外周血分离培养单核细胞，25μg／mL牙龈卟啉菌内毒素作为刺激因子，观察6．25、12．5、25、50、100μg/mL五种质量浓度的五倍子提取物对单核细胞分泌细胞因子白介素—lβ活性的影响，以放射免疫分析法(RIA)测定白介素—lβ的水平。结果：五倍子提取物可显著抑制牙龈卟啉菌内毒素介导单核细胞分泌白介素—lβ的活性，其作用在一定范围内呈浓度依赖性。结论：五倍子提取物抑制牙龈卟啉菌内毒素介导的白介素—lβ的活性，揭示五倍子提取物抗炎作用的机制。     

五倍子水提取物抑制内毒素诱导人牙龈成纤维细胞分泌IL-6

目的：研究不同浓度五倍子水提取物对内毒素(LPS)介导的人牙龈成纤维细胞(HGF)分泌IL-6水平的影响。方法：采用MTT比色法和放射免疫分析法(RIA)，测定五倍子水提取物对HGF增殖的影响；及对以25μg／mL内毒素作为刺激因子，HGF培养上清中IL-6水平的影响。结果：五倍子水提取物可显著抑制内毒素诱导HGF分泌IL-6水平，其作用在一定范围内呈浓度依赖性，同时当其浓度＞50μg／mL时，可抑制HGF增殖。结论：五倍子水提取物能够抑制内毒素诱导人牙龈成纤维细胞分泌IL-6的水平，浓度过高时对HGF增殖有影响，提示一定浓度(＜50μg／mL)的五倍子水提取物具有抗炎作用，有助于对牙周病的防治。     

五倍子水提取物对牙龈卟啉菌内毒素诱导人单核细胞CD14表达改变的影响

目的 :研究五倍子水提取物对牙龈卟啉菌内毒素 (PgLPS)诱导人单核细胞CD1 4表达改变的影响。方法 :采用人外周血分离培养的单核细胞 ,以 2 5 μg/mL内毒素作为刺激因子 ,观察五倍子水提取物对单核细胞CD1 4表达改变的影响 ,用流式细胞仪 (FCM )测定细胞膜表面CD1 4的表达。结果 :五倍子水提取物作用后 ,牙龈卟啉菌内毒素诱导人单核细胞膜表面CD1 4的表达的阳性细胞率从 6 9.9%± 2 .3 %下降至 4 5 .9%± 3 .7%。结论 :五倍子水提取物能够减少牙龈卟啉菌内毒素诱导人单核细胞膜表面CD1 4的表达 ,提示五倍子具有一定的抗炎作用 ,有助于对牙周病的防治。     

五倍子水提取物对内毒素诱导人牙髓细胞分泌IL-6的影响

目的:观察不同浓度五倍子水提取物对内毒素诱导人牙髓细胞分泌IL-6的影响.方法:采用组织块法体外培养人牙髓细胞,以含不同浓度五倍子水提取物(1.25、2.5、5.10、20 μg/mL)、25μg/mL内毒素和20mL/L新生牛血清的DMEM培养基作用于第5代人牙髓细胞,用放射免疫法测定IL-6含量,采用单因素方差分析(完全随机设计)和t检验对实验数据进行统计学分析.结果:低浓度(1.25、2.5、5、10、20μg/mL)五倍子水提取物能明显抑制25μg/mL内毒素诱导人牙髓细胞分泌IL-6,这种抑制作用在一定范围内呈浓度依赖性.结论:低浓度五倍子水提取物具有抑制内毒素诱导人牙髓细胞分泌IL一6的作用.     

五倍子水提取物对LPS抑制人牙龈成纤维细胞DNA合成和对细胞周期改变的影响

目的：研究五倍子水提取物对内毒素(LPS)引起人牙龈成纤维细胞(HGF)DNA合成和细胞周期改变的影响。方法：采用健康人正常牙龈组织原代培养的牙龈成纤维细胞，以25μg／mL LPS作为刺激因子，用流式细胞仪技术观察20μg／mL五倍子水提取物对LPS引起HGF细胞周期改变的影响。结果：LPS作用后，DNA合成前期细胞比例(G1期)明显上升，而DNA合成期细胞比例(S期)及细胞增殖指数下降，五倍子可改善此现象。结论：五倍子水提取物可显著改善LPS抑制HGF增殖，提示五倍子对牙龈组织具有保护作用，有助于牙周病的防治。     

五倍子水提取物对牙龈卟啉菌膜泡抑制牙周膜成纤维细胞生物活性的影响

目的:探讨五倍子水提取物对牙龈卟啉菌(Porphyromonas gingivalisPg)膜泡(extracellular vesicles ECV)抑制牙周膜成纤维细胞生物活性的影响。方法:采用体外培养的人牙周膜成纤维细胞,用3H-TdR掺入方法,检测ECV对人牙周膜成纤维细胞DNA合成的影响,以及中药五倍子提取物对ECV这一生物活性的阻断作用。结果:细胞培养物中加入50μg/mLECV时,人牙周膜成纤维细胞DNA的合成受到明显抑制,与空白对照组相比P<0.01。当同时加入各浓度五倍子水提取物时其DNA合成量明显增加,与ECV组相比均(P<0.05),且随五倍子水提取物浓度升高,DNA的合成量也随之增高,并呈一定浓度依赖性。结论:适宜浓度的五倍子提取物可有效地阻断ECV的这种生物活性作用,从而可推测其对牙周病的发生、发展能起到一定的阻断作用。     

五倍子对牙龈卟啉单胞菌胰酶样蛋白酶活性的抑制作用

目的：观察五倍子水提取物对牙龈卟啉单胞菌胰酶样蛋白酶活性的影响。方法：通过应用荧光分光光度计检测荧光底物的降解测定酶活力。结果：浓度0.5g/L-1g/L的五倍子可以抑制50%的底物降解，4g/L的五倍子可抑制超过90%的底物降解。结论：五倍子水提取物可有效抑制牙龈卟啉单胞菌胰酶样蛋白酶活性，其抑制作用可能会降低细菌生长及其毒力，减缓牙菌斑的形成。     

内毒素耐受对人牙龈上皮细胞分泌IL-1β、IL-6和IL-8的影响

目的:观察脂多糖(lipopolysaccharides,LPS)反复刺激细胞,诱导产生的内毒素耐受对人牙龈上皮细胞(human gingival epithelial cells,HGECs)分泌细胞因子IL-1β、IL-6和IL-8的影响。方法:采用1mg/L牙龈卟啉单胞菌(Porphyromonas gingivalis,P.gingivalis)LPS或1mg/L大肠杆菌(Escherichia coli,E.coli)LPS刺激HGECs 24h,洗涤细胞后,分别采用相同的LPS再次刺激24h,构建内毒素耐受模型。采用ELISA技术检测细胞条件培养液中IL-1β、IL-6和IL-8分泌水平的变化。结果:P.gingivalis LPS或E.coli LPS刺激HGECs 24h后,3种细胞因子的分泌水平均较刺激前明显增高(P<0.05)。2种LPS重复刺激,诱导细胞耐受后,IL-6和IL-8的分泌水平较第1次刺激后明显降低(P<0.05),但P.gingivalis LPS重复刺激后,IL-1β的分泌水平与第1次刺激后无明显差别。结论:内毒素耐受能抑制HGECs分泌细胞因子IL-6和IL-8,进而可能影响牙周组织的炎症和免疫反应。     

牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞炎性反应的体外研究

目的建立牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞炎性反应的体外模型，探讨牙龈卟啉单胞菌在牙周炎中的致病作用。方法用酶联免疫吸附法检测牙龈卟啉单胞菌膜泡对牙龈上皮细胞前列腺素E2（prostaglandin E2，PGE2）分泌的影响，以实时反转录聚合酶链反应法检测牙龈卟啉单胞菌膜泡对牙龈上皮细胞环氧化物酶（cyclooxygenase，COX）-2和白细胞介素（interleukin，IL）-6、IL-8基因表达的作用。结果牙龈卟啉单胞菌膜泡浓度依赖性地促进了牙龈上皮细胞PGE2的分泌，并使COX-2、IL-6、IL-8的mRNA表达水平显著上调。结论牙龈卟啉单胞菌膜泡诱导牙龈上皮细胞发生的细胞炎性反应，可能是牙周炎发生、发展的重要因素。     

五倍子对5种常见牙周细菌抑制作用的体外研究

目的：观察五倍子对5种常见牙周细菌的作用。方法：采用试管二倍稀释法，测定五倍子水提取物在体外厌氧环境对牙龈卟啉单胞菌，中间普氏菌，伴放线放线杆菌，具核俊杆菌和血链球菌的最小抑菌浓度（MIC），结果：五倍子对各实验细菌均有抑制作用。对牙周常见可疑致病菌牙龈卟啉单胞菌，伴放线放线杆菌，中间普错菌，具核梭杆菌的MIC值均为3．12％，对牙周有益菌血链球菌的MIC值则为12．5％，结论：浓度为3．12％的五倍子在不破坏牙周局部生态平衡的情况下可有效抑制牙周细菌的生长。     

不同剂型玻璃离子水门汀溶解性比较研究

目的:研究、比较不同剂型玻璃离子水门汀的溶解性和表面微观形态改变,为临床使用提供依据.方法:将3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)及GC玻璃离子水门汀(双糊剂型)分别在人工唾液中浸泡30 d,冷热循环15000次,烘干测重,比较前后质量变化,计算溶解率,并用扫描电镜观察表面微观改变.结果:不同剂型的玻璃离子水门汀溶解率由高到低分别为3M树脂加强型玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(水粉剂型)、GC玻璃离子水门汀(双糊剂型).3种玻璃离子水门汀经浸泡溶解后,SEM扫描表面微观形态可观察到GE玻璃离子水门汀(双糊剂型)表面形态改变较少,其他2组玻璃离子水门汀表面微观改变较多.结论:双糊剂型玻璃离子水门汀理化性能及溶解率均低于传统水粉剂型,是未来临床修复治疗的的良好选择.     

Evidence of the validity of a model of determinants of quality of restorative dental care

A model describing the relationship between self-reported quality of restorative dentistry and dentist characteristics for 119 Montana general dentists is presented. The best predictors formed a significant model explaining 22% of the variance of the quality measure. Results are contrasted with a previous estimation of the model for 102 Washington general practitioners. Evidence for the external validity of the model is presented.     

Design of clinical trials of traditional therapies of periodontitis

The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the "experimental unit". For a number of years, the "experimental unit" in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site-to-site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites. Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely: to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium; to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re-establishment of the subgingival infection; to gain attachment as a result of treatment; to assess the effect of a certain chemotherapeutic agent on periodontal disease.     

Experimental evidence of formation of imines in the course of reduction of hydrazones

The reduction of hydrazones is generally suggested to proceed through a reductive cleavage of the nitrogen–nitrogen bond followed by a reduction of the carbon–nitrogen bond. This sequence of reduction processes is here supported for fluorenone (V) and benzophenone (VI) hydrazones as well as by a comparison of the reduction of fluorenone and benzophenone hydrazonium ions (I,III) with corresponding imines (II,IV). Another proof of the presence of imines as intermediates is the splitting of four-electron waves of hydrazones V and VI and hydrazonium ions I and VIII into two waves at pH < 2. This has been interpreted as due to differences in slopes dE_1/2/dpH and pK_a-values of protonated hydrazine derivatives on one side and corresponding imines on the other. In this pH-range imines formed in reductions of VI and VIII are reduced in a single two-electron wave, those of I and V in two one-electron steps. Fluorenone imine (II) is sufficiently stable to allow recording of time-independent current–voltage curves between pH 6 and 11. In this pH-range the imine (II) is reduced in two one-electron steps. Benzophenone imine (IV) has been found stable between pH 4.6 and 12. At pH 4.6–8 the reduction of the imine IV takes place in a single two-electron step, at pH 8–12 in two one-electron steps. Final proof of the initial cleavage of the N–N bond is presented by comparison with the reduction of nitrones.     

Evaluation of efficacy of chemiluminescence for diagnosis of leukoplakia

ObjectiveLeukoplakia is the most common potentially malignant disorder preceding oral cancer. Chemiluminescence has been developed as an adjunct to conventional examination for the diagnosis of these potentially malignant disorders. This study was conducted to assess the efficacy of chemiluminescence in the diagnosis of leukoplakia and to compare the results with histopathological examination.Study designA total of 50 patients with leukoplakia were included from the outpatients attending the Department of Oral Medicine and Radiology, Dental Hospital, Bengaluru, Karnataka, India. These patients were subjected to conventional oral examination followed by chemiluminescent examination with Vizilite (Zila, Fort Collins, CO, USA) and biopsy for histopathological confirmation.ResultsThe sensitivity, specificity, positive predictive value, and negative predictive value of chemiluminescence were 93.75%, 55.56%, 78.95%, and 83.3%, respectively. The overall accuracy of chemiluminescence was 80%. A statistically significant association was observed between histopathology results and chemiluminescence results.ConclusionAlthough it is an easy, safe, minimal time consuming, and noninvasive technique, it has only adjunctive utility and it does not replace biopsy for the diagnosis of leukoplakia.     

正常青年Monson球面半径的测量研究

目的测量正常青年Monson球面半径。方法选择60名(男30名,女30名)正常青年制取全口印模,应用立体摄影成像的原理与方法对Monson球面半径进行测量和统计学处理。结果Monson球面的半径平均为10.173 cm,大于理论值10.160 cm,差异有显著性(P<0.01);男、女性球面半径差异无显著性。结论本实验所得到的数据可作为全口义齿修复中记录颌位关系的一个参量。     

正畸患者切牙影像失真发生情况分析

目的研究正畸患者曲面体层片上的切牙影像失真发生情况，并分析其原因。 方法从中山大学附属口腔医院放射科影像数据库中选取500例正畸患者的曲面体层片和头影测量侧位片，所有曲面体层片均采用咬合杆投照，分别从切牙牙体影像放大、缩小、牙根变短、根尖模糊等评价指标分析上下颌切牙影像失真的发生情况，在头影测量侧位片上测量中切牙根尖-对颌切牙切缘的距离，探讨切牙影像失真发生的原因。采用SPSS 19.0统计软件对所得数据进行统计学检验。 结果500例患者中，切牙牙体影像正常者共417例，切牙牙体影像失真者共83例，影像失真发生率16.6%，其中切牙牙体影像放大17例、牙体影像缩小0例、牙根变短30例，牙根影像变短伴模糊36例。影像失真患者的根尖-切缘距离大于影像正常的患者，差异有统计学意义（F = 5 187.18，P = 0）；影像失真患者的覆盖值大于影像正常的患者，差异有统计学意义（F>477，P = 0）。 结论严重牙颌面畸形如反 、深覆盖是导致曲面体层片的切牙影像失真的主要原因之一。     

颌骨动静脉畸形的栓塞治疗

目的：总结直接穿刺结合经血管内介入栓塞治疗颌骨动静脉静脉畸形的经验。方法：收治凳骨动静脉畸形患者6例,均进行了介入栓塞治疗。采用的栓塞材料为附凝血棉纤毛的螺圈,聚乙烯醇泡沫微粒和二氰基丙烯酸对丁酯。数字减影颈动脉造影在PHILIPSV300下完成。结果6例颌骨动静脉畸形患者中4,例急性出血得到了快速、有效控制,1例慢性渗血的右下 骨动静脉畸形患者,介入栓塞治疗,拔除松动的右下凳第一磨牙,有效地控制了出血,另1例伴局部软组织搏动性膨隆的上凳骨动静脉畸形患者,介入治疗后膨隆的搏动性得到明显改善,栓塞治疗后分别随访3－24个月,均未发现有口腔内渗血或出血。随访的X线片上,病灶区可见新骨形成。结论：局部穿刺结合经血管内介入栓塞治疗颌骨动静畸形是一种安全、有效的治疗方法。     

Electrodeposition of bilayers of dithiols

We report an electrochemical method to form a bilayer of dithiol. The cyclic voltammogram of the oxidative deposition of an aromatic dithiol on gold from an alkaline aqueous solution reveals two current peaks separated by more than 400 mV. The integrated charge of the oxidative current peak (B) at the most positive potential is twice that of the other oxidative current peak (A). These two oxidative current peaks were characterized by differential capacitance and electrochemical quartz crystal microbalance (EQCM) measurements. A decrease of the capacity by a factor of two, and an increase of the EQCM frequency change by a factor of two were observed when the potential was scanned from a value where only the first oxidative peak (A) is obtained, to a potential where both oxidative current peaks (A and B) are obtained. Infrared spectra show that the aromatic dithiols adsorb vertically at potentials corresponding to the current peak A and they become tilted for potentials corresponding to the current peak B. The simple relationships between the properties of the two oxidative current peaks are found to be compatible with a step-wise oxidative deposition of a bilayer of dithiol.