糖基化终末产物对人牙周膜干细胞骨向分化过程中的Wnt经典信号通路研究

目的 探讨Wnt经典通路相关因子Dickkopf蛋白1（DKK-1）、β-链蛋白（β-catenin）在糖基化终末产物（AGEs）介导的人牙周膜干细胞（hPDLSCs）骨分化过程中的变化。方法 通过体外组织块法和有限稀释法克隆化培养获取hPDLSCs,实验分两组：正常hPDLSCs组（N-hPDLSCs组）和AGEs刺激的正常hPDLSCs组（A-hPDLSCs组）。对2组细胞成骨矿化诱导后行碱性磷酸酶（ALP）和茜素红染色;实时聚合酶链反应（real time PCR）检测成骨基因,以及Wnt经典通路中相关因子DKK-1、β-catenin;Western blot检测相关成骨蛋白、细胞核蛋白β-catenin。结果 成骨诱导后,A-hPDLSCs组ALP染色明显浅于N-hPDLSCs组;茜素红染色A-hPDLSCs组钙化结节少于N-hPDLSCs组;real time PCR与Western blot的结果显示A-hPDLSCs组BSP、ALP、Runx-2的表达都较低,差异有统计学意义（P<0.05）。Wnt经典信号通路中相关因子：A-hPDLSCs组β-catenin表达高于N-hPDLSCs组,A-hPDLSCs组DKK-1表达明显低于N-hPDLSCs组,并且Weston blot显示A-hPDLSCs组核蛋白β-catenin的表达高于N-hPDLSCs组。结论AGEs可以使hPDLSCs骨向分化过程中Wnt经典通路的抑制因子DKK-1下调,细胞核中的β-catenin表达升高,激活了Wnt经典通路,并且抑制了骨分化。     

糖基化终末产物对牙周膜干细胞增殖及其Wnt经典信号通路相关基因表达的影响

目的:观察糖基化终末产物(AGEs)对人牙周膜干细胞(HPDLSC)增殖及其Wnt经典信号通路相关基因DKK-1、β-catenin表达的影响。方法:体外组织块法和有限稀释法克隆化培养HPDLSC,并与100μg/mL AGEs共同培养,通过细胞克隆形成率、细胞生长曲线观察AGEs对HPDLSC增殖能力的影响;RT-PCR和Western Blot检测实验组和对照组DKK-1、β-catenin mRNA以及核蛋白β-catenin的表达量。结果:经100μg/mL AGEs刺激的HPDLSC,其克隆形成率、增殖速度以及β-catenin mRNA和核蛋白β-catenin的表达量均明显低于对照组(P<0.05);而DKK-1 mRNA则明显高于对照组(P<0.05)。结论:AGEs能抑制HPDLSC的增殖及其Wnt经典信号通路。     

DKK-1在大鼠牙囊细胞体外的表达作用研究

目的观察Wnt/β-catenin通路的抑制因子DKK-1(Dickkopf-1)在牙囊细胞中的表达,探究在牙囊细胞成骨向分化形成过程中DKK-1的特异性表达机制,探讨其与牙齿萌出和颌骨生长发育的相关性。方法采用酶消化法分离培养牙囊细胞并纯化。将牙囊细胞分为两组,对照组:普通α-MEM培养基培养,实验组:α-MEM+成骨诱导液培养。分别培养5 d后,采用免疫细胞化学法观察DKK-1的表达分布;分别培养10、20 d后采用Western Blot检测DKK-1、β-catenin、Runx2的蛋白表达水平。结果免疫组化显示DKK-1在实验组表达较对照组减弱。Western Blot检测结果示实验组Wnt通路的关键因子DKK-1条带蛋白表达明显下调,β-catenin蛋白及成骨相关蛋白Runx2的表达明显上调,培养时间越长实验结果与对照组区别越明显。结论 Wnt通路DKK-1在牙囊细胞中有表达且受成骨分化影响,体现Wnt/β-catenin通路中DKK-1的抑制作用,研究结果将为牙齿萌出和颌骨生长发育形成机制提供实验依据。     

糖原合成酶激酶3β对炎症状态下牙周膜干细胞成骨分化能力的影响

目的：探讨炎症微环境作用下牙周膜干细胞成骨分化能力的变化及糖原合成酶激酶3β（glycogen synthesis kinase,GSK3β）对其成骨分化能力的影响。方法：培养正常及慢性牙周炎组织来源的牙周膜干细胞（H-PDLSCs,P-PDLSCs）,将两种PDLSCs体外成骨诱导7d,实时定量PCR检测细胞Runx2、 ALP、 OCN的基因表达水平, Western Blot检测p-GSK3β, GSK3β的蛋白表达情况。在成骨诱导时使用GSK3β特异性抑制剂LiCl刺激PDLSCs, ALP染色、 RealTime PCR检测PDLSCs成骨分化的情况。结果： P-PDLSCs的成骨化能力显著低于H-PDLSCs。 P-PDLSCs组p-GSK3β表达较H-PDLSCs组增高,成骨诱导后,两种PDLSCs中p-GSK3β表达降低,但GSK3β总蛋白表达水平增高。 LiCl抑制GSK3β后PDLSCs的ALP活性、 Runx2和OCN表达水平显著降低。结论：在慢性炎症微环境中, GSK3β的磷酸化可影响Wnt信号通路,抑制牙周膜干细胞的成骨分化。     

姜黄素通过调控Wnt通路改善牙周膜干细胞成骨分化能力

目的:探讨姜黄素对人牙周膜干细胞(PDLSCs)成骨分化的影响。方法:取第4~6代的PDLCs进行实验,用CCK-8实验检测姜黄素对PDLCs增殖活性影响,通过检测碱性磷酸酶(ALP)活性、矿化结节染色以及ALP、OCN和Runx2等成骨相关基因的表达水平来探讨姜黄素对牙周膜干细胞成骨分化能力的影响,同时检测姜黄素对经典Wnt通路及其配体的影响。结果:姜黄素对PDLSCs的增殖能力无影响。与对照组相比较,姜黄素能增加PDLSCs的ALP活性、上调ALP、OCN和Runx2等成骨相关基因的表达、增加矿化结节数量(P<0.05)。姜黄素能阻断Wnt信号通路,但加入Wnt信号通路激动剂(氯化锂)后,PDLSCs的成骨分化能力显著下降。结论:姜黄素能通过抑制Wnt信号通路,增强牙周膜干细胞成骨分化能力。     

细胞外信号调节激酶1/2信号转导通路调控牙周膜细胞成骨分化的研究

目的：探索细胞外信号调节激酶（ERK）1/2信号转导通路是否参与调控牙周膜细胞的成骨分化。方法???取体外培养的第3代牙周膜细胞进行研究。实验分为空白对照组、成骨诱导组和实验组（在成骨诱导培养基中加入10?nmol·L－1?ERK1/2磷酸化的抑制剂PD98059）。培养1周和3周后通过定量聚合酶链反应（qPCR）、碱性磷酸酶（ALP）染色和茜素红染色检测其成骨能力。结果?成骨诱导可促进牙周膜细胞中ERK1/2的磷酸化。培养1周后,抑制ERK1/2的磷酸化可上调成骨标志物Runx2、ALP和骨钙蛋白（OCN）的表达,与成骨诱导组相比较,OCN的表达差异具有统计学意义（P<0.05）,Runx2、ALP的表达差异也具有统计学意义（P<0.01）。培养3周后,实验组牙周膜细胞成骨标志物Runx2、ALP和OCN的表达仍较成骨诱导组高,ALP染色和钙结节形成较成骨诱导组强,其中Runx2、ALP的表达差异具有统计学意义（P<0.05）,OCN的表达差异也具有统计学意义（P<0.01）。结论 ERK?1/2信号转导通路参与了调控体外培养的牙周膜细胞的成骨分化。     

经典Wnt信号通路在牙周膜细胞成骨分化过程中的调控

目的: 探讨经典Wnt/β-catenin信号通路对牙周膜混合细胞群成骨分化过程中的调控作用。方法: 体外组织块结合酶消化法培养牙周膜混合细胞群,通过RT-PCR、real-time PCR证实经典Wnt信号通路在牙周膜细胞中的表达,并运用细胞免疫荧光分析检测了β-catenin的表达位置及表达量;通过不同浓度的Licl激活牙周膜细胞中经典Wnt信号通路,并进行相应的诱导培养。培养14 d后,茜素红染色观察矿化结节形成情况,碱性磷酸酶活性检测ALP活性;通过CCK-8检测Licl刺激24 h、48 h、72 h后经典Wnt信号通路对牙周膜细胞增殖的影响。以单因素重复测量方差分析比较差异。结果: 经典Wnt/β-catenin信号通路在牙周膜混合细胞群中明显表达,可以通过Licl激活该信号通路,使β-catenin在细胞中累积引起下游变化;与对照组相比较,经典Wnt/β-catenin信号通路的激活引起牙周膜细胞矿化过程中矿化结节的减少,显著降低了ALP活性(P<0.01);经典Wnt通路对牙周膜混合细胞群增殖表现为显著的抑制作用(P<0.01)。结论: 经典Wnt/β-catenin信号通路抑制了牙周膜混合细胞群的矿化成骨过程,并抑制该细胞群的增殖。     

SMURF2/β-catenin轴促进张力条件下人牙周膜细胞成骨分化

目的:探究Smad泛素化调节因子2(SMURF2)在循环牵张力诱导人牙周膜细胞(hPDLCs)成骨分化中的作用和机制。方法:对hPDLCs施加循环牵张力刺激后使用qRT-PCR检测SMURF2的表达和成骨相关基因的表达,使用western blotting检测SMURF2和经典WNT信号相关分子的表达,通过ALP染色检测hPDLCs的ALP活性,并结合成骨相关基因的表达评估hPDLCs的成骨分化。通过使用小干扰RNA沉默hPDLCs中的SMURF2基因探究SMURF2对牵张力诱导的hPDLCs成骨分化和经典WNT信号的影响。结果:循环牵张力刺激hPDLCs后SMURF2、ALP、OPN、OSX、COL-1和β-catenin表达升高,ALP活性也增强。沉默SMURF2基因后,hPDLCs的ALP活性减弱,ALP、OPN和OSX基因表达水平下降,β-catenin蛋白下降,但GSK-3β蛋白无变化。结论:SMURF2可能通过经典WNT信号通路促进循环牵张力诱导的hPDLCs成骨分化。     

富血小板纤维蛋白通过Wnt/β-catenin信号通路促进BMSCs成骨分化的研究

目的 :研究富血小板纤维蛋白(PRF)通过Wnt/β-catenin信号通路对骨髓基质干细胞(BMSCs)分化的影响。方法:分离、培养原代兔BMSCs,取第三代细胞进行干细胞鉴定,收集同一只兔耳缘静脉血离心制备PRF,将PRF与BMSCs置于Transwell小室中共培养并进行成骨分化。实验分组:A组为单纯BMSCs对照组;B组为PRF与BMSCs共培养组;C组为加入DKK1的PRF与BMSCs共培养组;D组为加入Wnt3a的PRF与BMSCs共培养组。茜素红染色观察各组钙结节形成情况,碱性磷酸酶(ALP)试剂盒检测各组ALP活性,定量聚合酶链反应(q RT-PCR)检测成骨成脂相关基因Runx2、OCN、PPARγ2及LPL的m RNA表达,同时检测Wnt/β-catenin信号通路关键因子Cyclin D1及β-catenin的m RNA表达。结果:流式细术检测结果显示,原代培养的BMSCs符合间充质干细胞鉴定标准。茜素红染色结果显示,B组和D组的钙结节数量明显多于A组和C组,A组和C组之间无明显差异。碱性磷酸酶(ALP)活性检测结果显示,B组与D组的ALP活性较A组和C组明显增加(P<0.05),且两组之间差异无明显统计学意义。q RTPCR结果显示B组与D组中的成骨分化标志基因Runx2、OCN的m RNA表达,较A组和C组显著增加(P<0.05),而成脂分化标志基因PPARγ2、LPL的m RNA表达显著降低(P<0.05)。此外,B组和D组中Wnt/β-catenin信号通路关键因子Cyclin D1及β-catenin的m RNA表达较A组和C组显著增加(P<0.05)。结论:PRF通过激活Wnt/β-catenin信号通路促进BMSCs成骨分化而抑制其成脂分化。     

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.     

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.     

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.     

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.     

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。     

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.     

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。     

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。     

鼻测量法的进展

唇裂术后继发畸形是指唇裂修复术后,仍遗留或继发于手术操作和生长发育变化而表现出来的一类畸形[1]。包括唇畸形、鼻畸形和颌骨畸形。其修复较原发性唇裂修复更复杂,更灵活多变。而导致其修复复杂性的一个重要原因即是局部组织结构复杂变异和缺乏可靠的三维测量手段[2],鼻畸形     

口底癌34例临床分析

目的探讨口底癌的临床特性、治疗方法及预后。方法对我院自1992—2002年住院治疗的34例口底癌患者进行回顾性分析。结果34例口底癌患者中,男28例(82.4%),女6例(17.6%),男女比为4.7∶1,平均发病年龄58岁。发病部位:前口底22例(64.7%),后口底12例(35.3%)。淋巴结转移率41.2%。单纯手术组、化疗加手术组、放疗加手术组、化疗加手术加放疗组的5年生存率分别为45.5%、60.0%、50.0%、62.5%。结论口底癌以中老年患者好发,男性居多。易发生淋巴结转移,综合疗法疗效较好。