高+Gx环境对猴翼内肌C-jun基因表达的影响

目的:探索高 Gx环境是否造成翼内肌病理性损伤和对c-jun表达的影响。方法:以9只雄性恒河猴为对象,按受试Gx环境、持续时间,随机分4组:对照组为 1Gx、300s;实验组为3组,分别为 15Gx、200s; 18Gx、165s; 21Gx、140s。采用组织病理学、免疫组织化学方法,观察模拟高正加速度环境下猴翼内肌肌细胞组织和c-jun基因表达的变化。结果:组织病理学观察,实验组、对照组猴翼内肌组织结构无明显变化;免疫组织化学观察,对照组翼内肌细胞核c-jun呈阴性或弱阳性表达,而细胞质着色不明显。实验组翼内肌细胞核c-jun着色明显,呈强阳性表达,不同高 Gx组之间无明显差别。结论:高于 15Gx的环境可引起猴翼内肌细胞c-jun基因表达增强。     

高+Gx环境对猴颞肌c-jun蛋白表达影响的研究

目的:观察高过载( Gx)环境对颞肌组织病理学及c-jun蛋白表达的影响。方法:以9只雄性猕猴为对象,按受试Gx环境及持续时间随机分4组,对照组为 1Gx、300s(2只);实验组为3组,分别为 15Gx、200s(2只); 18Gx、165s(2只); 21Gx、140s(3只)。采用病理学和免疫组织化学方法,观察模拟高过载( Gx)环境下猴颞肌肌细胞组织及c-jun蛋白表达的变化。结果:组织病理学观察:实验组和对照组猴颞肌肌细胞无明显变化;免疫组织化学观察:对照组颞肌c-jun呈阴性或弱阳性表达,主要位于肌细胞核,胞质着色不明显。实验组颞肌细胞核c-jun着色明显,呈强阳性表达,不同高过载( Gx)组之间无明显差别。结论:高过载( Gx)环境中,猴颞肌细胞c-jun蛋白表达明显增强。     

高正加速度环境对猴舌横纹肌c-fos基因表达的影响

目的 探索高正加速度( Gx)环境是否造成舌肌病理性损伤.方法 以9只雄性猕猴为对象,按受试Gx环境及持续时间随机分4组,对照组为 1Gx、300 s;实验组为3组,分别为 15Gx、200 s; 18Gx、165 s; 21Gx、140 s.采用病理学和免疫组织化学方法,观察模拟高正加速度环境下猴舌横纹肌肌细胞组织及c-fos基因表达的变化.结果 组织病理学观察:实验组和对照组猴舌横纹肌细胞无明显变化;免疫组织化学观察:对照组舌横纹肌细胞膜c-fos呈弱阳性表达,而细胞浆着色不明显.实验组舌横纹肌细胞膜、细胞浆c-fos着色明显,呈强阳性表达,不同高 Gx组之间无明显差别.结论 高于 15Gx的模拟正加速度环境可引起猴舌横纹肌细胞c-fos基因表达增强.     

高正加速度环境对猴舌横纹肌细胞癌基因c-jun表达的影响

目的：观察模拟高( Gx)环境对猴舌横纹肌细胞癌基因c-jun表达的影响。方法：以雄性猕猴9只为实验对象，随机分为4组．对照组为 1Gx、300s；实验为3个亚组，分别为 15Gx、200s； 18Gx、165S； 21Gx、140s。采用模拟高( Gx)作用的动物离心装置．观察猴舌横纹肌细胞组织病理学改变及c-jun表达的影响。结果：组织病理学观察，实验组和对照组猴舌横纹肌细胞无明显变化；免疫组化学观察，对照组舌横纹肌细胞膜c-jun可见着色．呈弱阳性。实验组舌横纹肌细胞膜、细胞浆c-jun着色明显．呈强阳性，不同高 Gx组之间无明显差别。结论：模拟高( Gx)环境可引起猴舌横纹肌细胞c-jun表达增强。     

高+Gx环境对猴口腔黏膜上皮c-fos表达的影响

目的:观察模拟空间环境航天应急返回过程中高 Gx对猴口腔黏膜上皮细胞c-fos表达的影响.方法:以9只雄性猕猴为对象,随机分为4组,对照组承受 1 Gx、300 s的超重作用;实验组根据承受过载峰值的大小分为3个亚组,分别承受过载峰值为 15 Gx、200 s; 18 Gx、165 s; 21 Gx、140 s的超重作用.采用常规组织病理学方法,观察猴口腔黏膜上皮细胞的改变;采用免疫组织化学PicTureTM两步法,观察高 Gx对猴口腔黏膜上皮c-fos表达的影响.结果:组织病理学观察显示,对照组和实验组动物口腔黏膜上皮均未见明显病理学改变.免疫组化学观察显示,实验组口腔黏膜上皮基底细胞和棘细胞呈深棕色,为c-fos强阳性表达,对照组口腔黏膜上皮部分基底细胞和少量棘细胞呈浅棕色,为c-fos弱阳性表达.高 Gx实验组之间口腔黏膜上皮c-fos表达无明显差异.结论:高 Gx可引起猴口腔黏膜上皮细胞c-fos表达增强.     

模拟失重后再超重对猴咬肌细胞SERCA mRNA表达的影响

目的：探讨模拟失重后再超重环境对猴咬肌细胞SERCA1a、SERCA2a mRNA表达的影响。方法：健康雄性猕猴23只,随机分为正常对照组（A组）和实验组：模拟失重（B组）,模拟超重（C组）,失重后再超重分别为＋11Gx/270s（D1组）、＋13Gx/230s（D2组）、＋15Gx/200s（D3组）和＋13Gx/230s恢复第10d（D4组）。实验期间,各组喂养条件相同,在实验结束后动物恢复第2d（A、B、C、D1、D2、D3组）和恢复第10d（D4组）处死取材,组织置于液氮中保存。采用常规方法制作冰冻切片,通过HE染色观察猴咬肌细胞组织形态学变化;使用RT-PCR方法检测猴咬肌细胞SERCA1a、SERCA2a mRNA的表达。结果：组织病理学观察可见,对照组猴咬肌细胞结构正常;实验组咬肌细胞胞膜边界模糊不清,间质增宽;模拟失重后再超重组肌细胞肿胀,偶见细胞核呈扁平状,移位胞浆中央。采用RT-PCR检测发现,各实验组与对照组相比,猴咬肌细胞SERCA1a mRNA表达均增强,SERCA2a mRNA除D4组外,其他实验组表达增强,其差异有统计学意义（P〈0.05）;D2、D3组与B组相比,SERCA1a mRNA表达升高,差异显著（P〈0.01）;D2、D3组与C组比较,SERCA1a mRNA表达增强,有显著差异（P〈0.01）;D4组与D2组比较,SERCA1a、SERCA2a mRNA表达均下降,有统计学意义（P〈0.05）。结论：模拟失重、模拟超重和模拟失重后再超重环境均可造成猴咬肌细胞组织形态学不同程度地改变,并可引起SERCA1a、SERCA2a mRNA表达增强,其中模拟失重后再超重恢复第10d咬肌细胞组织形态学趋于正常结构,SERCA1a、SERCA2a mRNA表达呈恢复下降趋势。     

模拟失重及高+Gx对猴舌横纹肌细胞c-fos表达的影响

目的探讨模拟失重30d后高+Gx暴露对猴舌横纹肌细胞c-fos表达的影响。方法 16只雄性猕猴随机分为4组,即正常对照组(A)、30d模拟失重组(B),+13Gx/230s组(C)、30d模拟失重后超重组(D),其中D组根据过载峰值又分为+11Gx/270s(D1)、+13Gx/230s(D2)和+15Gx/200s(D3)。动物放血处死,解剖取材后,经10%中性福尔马林固定,石蜡包埋切片,采用组织病理学和免疫组化的方法,观察猴舌横纹肌组织结构及c-fos的表达情况。结果 A组可见正常的舌横纹肌结构,其他组舌横纹肌细胞结构基本正常,偶见细胞间质稀疏,横纹不清或消失。A组舌横纹肌细胞c-fos呈阴性表达,胞核、胞浆着色不明显。实验组舌横纹肌细胞"横纹"着深棕色,即胞浆呈强阳性表达。免疫组化光密度值显示,对照组与实验组,B组与D3组差异有统计学意义(P<0.05)。结论 30d模拟失重和高+Gx均可引起舌横纹肌细胞c-fos强阳性表达,舌横纹肌受到了一定程度的损伤。模拟失重降低了舌横纹肌细胞对+Gx的耐受性,两者具有一定的协同性。     

模拟失重及高+Gx对猴舌横纹肌细胞结构及HSP70表达的影响

目的探讨模拟失重及高+Gx对猴舌横纹肌组织结构和热休克蛋白70(heat shock protein 70,HSP70)表达的影响。方法 12只雄性猕猴随机分为4组,正常对照组(A)、30d模拟失重组(B),+13Gx/230s组(C)、30d模拟失重后超重组(D),其中D组根据过载峰值又分为+11Gx/270s(D1)、+13Gx/230s(D2)和+15Gx/200s(D3)。动物放血处死后取材,采用组织病理学和免疫组化的方法,观察猴舌横纹肌组织结构及HSP70的表达情况。结果 A组可见正常的舌横纹肌结构,其他组舌横纹肌细胞结构基本正常,偶见细胞间质稀疏,细胞排列紊乱以及横纹不清或消失。A组舌横纹肌细胞HSP70呈阴性表达,细胞核与细胞浆均无明显着色;B组、C组和D组舌横纹肌细胞胞核与胞浆均着色明显,呈阳性表达,较A组变化显著。HSP70免疫组化积分显示,D组比B组和C组变化显著(P<0.05),但D1、D2、D3无明显差别(P>0.05)。结论 30d模拟失重和高+13Gx/230s均可使猴舌横纹肌细胞产生应激反应,引起HSP70的表达增强,并可能伴有损伤。模拟失重与过载超重具有协同作用,两者可能加重了对舌横纹肌的影响。     

高正加速度环境对猴口腔黏膜上皮细胞热休克蛋白70表达的影响

航天飞船在升空和返回阶段 ,机体可受到超重高正加速度 ( Gx)的作用。研究表明 ,超过 3Gx负荷可影响人体正常的生理功能。我们以猴为对象 ,采用模拟高 Gx作用的动物离心装置 ,观察猴口腔黏膜的组织病理学改变及热休克蛋白 70 (heat shockprotein 70 ,HSP 70 )表达的影响。1.材料与方法 :实验用雄性恒河猴 9只 ,年龄 5～ 12岁 ,体重 5～ 8kg ,健康。随机分为对照组和实验组。对照组 1Gx、30 0s( 2只 ) ;实验组分 3个亚组 :1组 15Gx、2 0 0s( 2只 ) ;2组 18Gx、16 5s( 2只 ) ;3组 2 1Gx、14 0s( 3只 )。采用改造后的五八型动物…     

成年大鼠下颌功能性前伸后翼外肌的超微结构改变

目的 观察成年大鼠下颌功能性前伸后翼外肌的超微结构变化.方法 成年雄性Sprague-Dawley大鼠40只,随机分为4个实验组和4个对照组,每组5只.实验组大鼠配戴固定的前伸下颌矫治器,对照组不配戴矫治器.分别于下颌前伸3、7、14、28 d处死实验组和对照组大鼠.取大鼠左右侧的翼外肌,制作电镜标本,透射电镜下观察成年大鼠翼外肌的超微结构变化.结果 在实验组大鼠翼外肌细胞内,下颌前伸3 d时,部分肌丝溶解断裂;下颌前伸7 d和14 d时,肌丝方向紊乱,肌小节宽度不规则;下颌前伸28 d时,局部仍可见肌丝方向紊乱和肌小节宽度不规则.下颌前伸3、7、14 d时实验组大鼠翼外肌细胞肌膜下及肌丝间线粒体增多,形态改变.下颌前伸28 d时,线粒体数量和形态基本正常.下颌前伸14 d时,在实验组大鼠翼外肌细胞内,终板内的神经递质较多.结论 成年大鼠下颌功能性前伸后翼外肌细胞的结构发生了改变.     

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。     

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.     

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。