饥饿期粪肠球菌生物膜毒力因子明胶酶E表达研究

目的:研究粪肠球菌生物膜形成相关毒力因子明胶酶E(gelE)在饥饿期及药物作用后的表达情况。方法:体外建立对数期、稳定期、饥饿期粪肠球菌生物膜模型,分别以1%、2.5%、5.25%次氯酸钠溶液作用于各时期粪肠球菌生物膜后,用Real-time PCR对gelE的基因表达相对量进行检测。结果:gelE基因表达相对量,饥饿期高于稳定期及对数期(P<0.05);用药后,3个期gelE基因表达相对量,5.25%次氯酸钠溶液组低于2.5%次氯酸钠溶液组和1%次氯酸钠溶液组(P<0.05)。结论:饥饿期粪肠球菌生物膜形成相关毒力因子gelE较对数期及稳定期表达增强。次氯酸钠浓度依赖性可抑制粪肠球菌毒力因子gelE的表达。     

粪肠球菌生物膜的药物敏感性研究

目的 建立体外粪肠球菌生物膜模型,评价10%氢氧化钙溶液和2%洗必泰溶液去除粪肠球菌生物膜的效果.方法 在玻片上形成4、8、12、24、48 h粪肠球菌生物膜,荧光染色后,采用激光共聚焦扫描显微镜(CLSM)观察;用10%氢氧化钙溶液和2%洗必泰溶液分别处理24 h生物膜3、10、30 min,采用CLSM观察;ANO...     

大蒜素标准品DATS体外抗粪肠球菌生物膜作用的研究

目的:探讨不同浓度大蒜素对照品二烯丙基化三硫(dially trisulfide,DATS)体外对粪肠球菌生物膜的作用。方法:体外培养形成粪肠球菌生物膜,分别经1280、2560、5120 mg/L浓度的DATS作用后,采用MTT法观察DATS对生物膜粪肠球菌的抑菌率。结果:1280 mg/L DATS对对数期和饥饿期的生物膜粪肠球菌抑菌率约71%,显著高于对稳定期生物膜粪肠球菌的抑菌率58%,差异具有统计学意义(P<0.05),随着药物浓度的增高,抑菌率增高。结论:DATS对生物膜中的粪肠球菌具有明显杀灭或抑制作用。     

饥饿状态粪肠球菌生物膜胞外多糖的合成能力

目的探讨饥饿环境对粪肠球菌生物膜胞外多糖合成能力的影响。方法体外培养饥饿状态粪肠球菌形成48h生物膜,凝集素标记结合倒置荧光显微镜观察胞外多糖分布情况,提取饥饿状态浮游粪肠球菌和对数期、稳定期、饥饿状态粪肠球菌48h生物膜胞外多糖,蒽酮法定量分析比较胞外多糖合成能力。结果饥饿状态粪肠球菌形成的48h生物膜内胞外多糖呈云絮状,与细菌分布区域不完全一致;生物膜细菌合成水溶性和水不溶性胞外多糖的能力均高于浮游细菌(P<0.05);其合成水溶性胞外多糖的能力与对数期和稳定期细菌无显著差别(P>0.05),合成水不溶性胞外多糖的能力高于后两者(P<0.05)。结论饥饿状态粪肠球菌合成生物膜胞外多糖的能力增强。     

PIPS联合纳米银对根管粪肠球菌抗菌效果研究

目的 探究激光引发光声流系统(PIPS)和纳米银(AgNPs)联合使用对根管内粪肠球菌生物膜的抗菌效果。方法 收集36颗单根管离体牙,建立粪肠球菌感染根管实验模型,将样本随机分成6组,采用0.9%NaCl、2%NaClO、0.1%AgNPs溶液分别联合传统手动冲洗(CNI)或PIPS对根管进行冲洗,使用菌落计数法测定治疗前后根管内粪肠球菌生物膜菌落数,并计算菌落计数减少的百分比。结果 所有实验组粪肠球菌生物膜的抑制效果均强于对照组(P<0.05),使用PIPS辅助0.9%NaCl、2%NaClO、0.1%AgNPs冲洗组的降幅均分别大于CNI辅助0.9%NaCl、2%NaClO、0.1%AgNPs冲洗组(P<0.05)。PIPS辅助0.1%AgNPs冲洗组的降幅明显大于PIPS辅助2%NaClO冲洗组(P<0.05)。结论 PIPS辅助AgNPs溶液冲洗可以显著提高根管内粪肠球菌生物膜的清除效果。     

激光扫描共聚焦显微镜观察碱性环境对粪肠球菌生物膜的影响

目的:比较不同碱性条件对生物膜状态粪肠球菌的影响。方法:制备粪肠球菌生物膜,分别用pH值为7、9和11的TSB培养液作用2 h后,用激光扫描共聚焦显微镜观察粪肠球菌生物膜的变化。结果:pH值由7升到9时,生物膜内、中、外各层活菌比例虽有所减少,但差异无统计学意义(P>0.05);当pH值11时,各层活菌比例虽然均较pH值为7和9时明显减少(P<0.05),但仍有大量活菌存在。结论:粪肠球菌对碱性环境具有强的耐受性,pH值为7～9时,对生物膜状态粪肠球菌无明显影响。     

茶多酚、MTAD和次氯酸钠液抑制粪肠球菌及其生物膜的作用比较

目的:检测中药茶多酚、MTAD、52.5 g/L次氯酸钠抑制根管壁粪肠球菌生物膜的能力,并分析中药茶多酚作为根管冲洗液的可行性。方法:采用微孔板滴定法检测茶多酚,MTAD和52.5 g/L次氯酸钠液对粪肠球菌的最小抑菌浓度(MIC)和最小杀菌浓度(MBC),采用琼脂扩散实验检测3种抗菌剂对粪肠球菌的抑菌圈。通过建立粪肠球菌感染根管3周和6周的模型,分别用茶多酚、MTAD和52.5 g/L次氯酸钠液对粪肠球菌感染后的根管进行处理,然后对根管壁生物膜中的细菌生存情况进行定性定量分析,比较这3种根管冲洗液抗粪肠球菌生物膜的能力。结果:MIC、MBC和琼脂扩散实验显示:3组冲洗剂对粪肠球菌均有抑制作用。在粪肠球菌感染根管3周的生物膜中,MTAD和次氯酸钠液可以完全抑制粪肠球菌生物膜,茶多酚处理后虽仍有粪肠球菌生长,但明显低于生理盐水处理组的细菌生存数,差异有统计学意义(P<0.05)。在粪肠球菌感染根管6周的生物膜中,次氯酸钠液可以完全抑制细菌生长,茶多酚和MTAD作用后仍有活菌生长,但与对照组相比,细菌生存数均显示了8个log值的下降,差异有统计学意义(P<0.05)。结论:52.5 g/L次氯酸钠液具有很强的抑制根管内粪肠球菌生物膜作用,而茶多酚和MTAD也具有一定的抑制粪肠球菌生物膜的能力。     

碱性pH对浮游状态和生物膜状态粪肠球菌活性的影响

目的:比较生物膜状态与浮游状态下粪肠球菌对碱的耐受性。方法:制备浮游状态和生物膜状态的粪肠球菌细胞,用pH值分别为7、8、9、10、11和12的培养液作用2h,利用MTT比色法比较2种状态下细菌细胞活性变化。采用SAS6.12软件包对数据进行统计学分析。结果:低碱性环境(pH值7～9)对粪肠球菌的生长无明显影响,高碱性环境(pH值>10)下存活细菌的比例明显减少;高pH环境下,生物膜状态的粪肠球菌存活细菌比例显著高于浮游状态下细菌的存活比例。结论:粪肠球菌对碱性环境具有强耐受性,形成生物膜是粪肠球菌抵抗高碱性环境的一个重要原因。     

饥饿状态的粪肠球菌的研究进展

作为顽固性或继发性根管内感染的主要致病菌,粪肠球菌可以饥饿状态在恶劣的环境中长期生存。在饥饿状态下,粪肠球菌可保持较低的代谢水平并形成生物膜,从而提高其对外界刺激的耐受水平。本文就饥饿状态与活的不可培养状态,饥饿状态下的粪肠球菌的生长状况,饥饿状态下的粪肠球菌的生物膜形成能力,饥饿状态下的粪肠球菌对外界刺激的耐受水平等研究进展作一综述。     

氯化镧对根管内粪肠球菌抗菌效果的体外实验

目的:研究氯化镧、FC、CP、氢氧化钙丙二醇糊剂4种根管消毒剂对离体牙根管内粪肠球菌的抗菌性能。方法:选取72个新鲜拔除的单根管前磨牙,随机分为4个实验组(氯化镧组、FC组、CP组、氢氧化钙丙二醇糊剂组)、1个阴性对照组和1个阳性对照组,每组12个牙。所有牙清理根管后灭菌,除阴性对照组不感染细菌外,其余各组均建立粪肠球菌感染根管模型。建模后,4个实验组分别在根管内放置氯化镧药液、FC、CP、氢氧化钙丙二醇糊剂;阴性和阳性对照组放置生理盐水,37℃、50 mL/L CO2培养箱内培养。分别于培养后3 d和7 d时,取各组根管内壁牙本质粉末用BHI培养基继续培养72 h,比浊仪检测各样本的浊度。结果:①药物处理第3天时,氯化镧组牙本质小管中残留菌量较阳性对照组少,但高于阴性对照组和FC组、氢氧化钙丙二醇糊剂组(P<0.05),与CP组无显著性差异(P>0.05);②药物处理第7天时,FC组、CP组、氢氧化钙丙二醇糊剂组和氯化镧组4种消毒剂牙本质小管内残留细菌量较阳性对照组有明显减少(P<0.05),与阴性对照组相比,差异均无统计学意义(P>0.05)。结论:根管内放置氯化镧药液7 d可有效抑制粪肠球菌生长。     

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。     

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。     

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。