SD大鼠骨髓间充质干细胞的体外分离培养鉴定及骨向诱导分化研究

目的：建立骨髓间充质干细胞（MSCs）体外分离培养体系,并进行骨向分化诱导以探讨大鼠MSCs的体外培养方法及向成骨细胞分化的条件。方法：采用全骨髓贴壁筛选培养法分离成年SD大鼠MSCs,经条件培养液诱导培养后,进行细胞形态学观察、绘制细胞生长曲线、免疫细胞化学检测及碱性磷酸酶活性、钙结节的形成测定。结果：SD大鼠MSCs在体外分离培养扩增形态呈长梭形,细胞生长曲线呈S形。诱导条件下,细胞碱性磷酸酶活性明显增高,并出现了矿化结节。结论：SD大鼠MSCs体外分离培养体系能够成功建立,培养出的细胞能向成骨细胞分化,可以作为骨组织工程的种子细胞。     

大鼠骨髓间充质干细胞与脂肪间充质干细胞生物学特性的比较

目的:本研究旨在比较同一个体来源的脂肪间充质干细胞(Adipose tissue-derived mesenchymal stem cells,ADSCs)和骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)的生长特点和诱导分化能力。方法:取7～10 d SD大鼠的脂肪和骨髓,体外分离、纯化脂肪和骨髓来源间充质干细胞,分别从细胞形态、生长动力学、表面标志、分化潜能等方面进行鉴定和比较。结果:脂肪间充质干细胞的增殖速度明显大于骨髓间充质干细胞(P<0.05),两种细胞所表达的表面蛋白标志物基本相似,但脂肪间充质干细胞表面蛋白标志CD106呈阴性,而骨髓间充质干细胞CD106呈阳性。在成软骨分化中脂肪间充质干细胞弱表达Ⅱ型胶原,而骨髓间充质干细胞不表达。第5、10、15、20代ADSCs及BMSCs经成骨诱导后茜素红染色均呈阳性且有"矿化"结节形成,碱性磷酸酶活性以第5代最强,随着细胞代次的递增,碱性磷酸酶活性呈递减趋势。结论:ADSCs较BMSCs更易于分离培养及体外扩增,诱导条件下成骨、成脂、成软骨能力较强,适合作为再生医学的种子细胞。     

骨髓间充质干细胞与骨相关研究

骨髓间充质干细胞具有向成骨细胞分化的潜能。骨髓间充质干细胞可体外分离、培养和扩增,可作为骨组织工程的种子细胞治疗骨相关疾病及作为载体用于基因治疗。本文综述了骨髓间充质干细胞在骨相关研究中的应用。     

骨髓间充质干细胞与骨相关研究

骨髓间充质干细胞具有向成骨细胞分化的潜能。骨髓间充质干细胞可体外分离、培养和扩增，可作为骨组织工程的种子细胞治疗骨相关疾病及作为载体用于基因治疗。本文综述了骨髓间充质干细胞在骨相关研究中的应用。     

兔骨髓基质干细胞骨向诱导实验研究

目的:研究兔骨髓基质干细胞(bone marrow stromal cells,BMSC)的体外培养以及骨向诱导分化情况,进一步探讨其作为骨组织工程种子细胞的可行性。方法:无菌条件下抽取兔的股骨骨髓,然后进行骨髓基质干细胞的分离和体外培养,并向成骨细胞定向诱导分化。结果:体外分离的骨髓基质细胞呈贴壁生长,改良MTT法测定显示骨髓基质细胞于第7.8天左右可达到增殖高峰;诱导后BMSC可向成骨细胞分化,细胞呈成骨细胞形态为梭形和多角形并可形成钙化结节。改良钙钴染色法检测诱导细胞碱性磷酸活性呈强阳性。扫描电镜观察细胞呈较典型的成骨细胞状态,并可见钙盐沉积。结论:骨髓基质细胞具有来源充足,取材方便,创伤小无明显并发症。骨髓基质干细胞分化增殖能力较强,成骨能力确定。所以采用骨髓基质细胞作为种子细胞构建组织工程骨有比较可靠的依据。     

兔骨髓间充质干细胞的分离培养与鉴定

［摘要］ 目的 寻求一种安全高效的兔骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs )的体外分离培养和鉴定方法。方法 采集兔胫骨骨髓组织,采用全骨髓贴壁培养法体外分离培养和扩增BMSCs;倒置相差显微镜观察细胞,取生长良好的第5代细胞成骨,免疫细胞化学染色和流式细胞术检测细胞表面标志物。结果 原代和传代的 BMSCs 贴壁生长,呈漩涡状排列生长;诱导后碱性磷酸酶活性持续高,有钙结节形成并茜素红染色阳性;CD29、CD44、CD105分子呈阳性, CD45、C-kit、CD34分子呈阴性。结论 成功建立了兔BMSCs 体外分离纯化、培养的有效方法,扩增的 BMSCs 具有多向分化潜能,是理想的组织工程种子细胞。     

组蛋白去甲基化酶KDM6A促进骨髓间充质干细胞成骨分化研究

目的研究组蛋白去甲基化酶KDM6A对骨髓间充质干细胞成骨定向分化能力的影响。方法构建Flag-KDM6A慢病毒表达质粒。利用慢病毒转染构建稳定过表达KDM6A的骨髓间充质干细胞。碱性磷酸酶活性实验检测成骨分化早期指标-碱性磷酸酶活性。茜素红染色及钙离子定量分析检测干细胞体外矿化能力。实时：毫量RT-PCR检测成骨分化相关基因．骨桥蛋白和骨钙素的表达。结果过表达KDM6A促进骨髓间充质干细胞碱性磷酸酶活性、骨髓间充质干细胞体外矿化能力以及骨桥蛋白和骨钙素的表达。结论组蛋白去甲基化酶KDM6A具有促进骨髓间充质干细胞成骨分化的潜能,可以作为一个候选的靶基因用于骨组织工程技术,促进骨组织再生。．     

体外培养骨髓间充质干细胞向成骨细胞分化的影响因素研究

探讨影响骨髓间充质干细胞向成骨细胞分化的因素。在骨组织工程中，骨髓间充质干细胞的成骨细胞分化率影响着骨量的形成。本文从诱导条件、细胞密度、支架材料、培养环境等方而综述了影响旗向成骨细胞分化的诸多因素，以期为获得更大量的组织工程化骨提供参考依据。     

兔骨髓间充质干细胞的体外分离培养、鉴定及向成骨细胞分化诱导

目的:探讨体外分离培养、鉴定兔骨髓间充质干细胞(BMSCs)的方法,并观察其向成骨细胞分化的潜能。方法:采用贴壁分离法分离培养兔BMSCs,通过细胞形态学观察和细胞表面抗原检测对细胞进行鉴定,并向成骨细胞分化诱导培养,通过钙钻法检测碱性磷酸酶表达,茜素红染色观察钙结节形成能力。结果:分离培养3d,可见贴壁细胞呈三角形、成纤维形或多角形外观,培养10～12d细胞长满瓶底,传代后细胞增殖明显加快;使用条件培养基传代培养2周,细胞呈集落生长后开始形成钙结节,茜素红染色阳性。结论:全骨髓贴壁法是一种简单实用的分离培养方法,可获得纯度较高的兔BMSCs,经过诱导后可向成骨细胞分化。     

人骨髓间充质干细胞的分离培养及向成骨细胞定向分化的实验研究

目的:建立人骨髓间充质干细胞(hMSCS)体外分离、培养体系,并将其向成骨细胞定向诱导分化。方法: 采用梯度离心法从人骨髓血中提取骨髓MSC,经体外培养扩增,观察其生物学特性。结果:在体外培养条件下,骨 髓MSC具有较强的增殖能力,并能被诱导向成骨细胞分化。结论:建立了骨髓MSC体外分离、培养的体系,探讨 了骨髓MSC的生物学特性,为进一步研究MSC作为骨组织工程的种子细胞打下了基础。     

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.     

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.     

《口腔医学》杂志2007年度有关信息的分析

目的通过对《口腔医学》2007年全年文献的回顾和分析,了解我国口腔临床医学的研究现状。方法阅读2007年《口腔医学》全年的文献,对各种信息进行了分类汇总,根据设计类型对临床一次性文献进行了分类,并对其中的试验性研究文章进行质量分析。结果《口腔医学》2007年全年的一次性文献274篇,基础和临床文献分别为108和166篇,以临床文献为主(60.58%)。在临床研究文献中,属于观察性、分析性和试验性的文献分别为97、9和60篇,观察性文献所占比例为36.14%,高于以往的报道。60篇观察性文献中,全都设有对照;统计方法应用得当者44篇;真正做到随机、盲法的分别只有4和2篇。结论我国口腔临床方面的研究水平近年来提高明显,但设计的科学性方面有待提高。     

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.     

口腔医学专业本科毕业生就业现状的调查分析和教育思考

目的研究口腔医学专业的教学如何面向市场,推出令用人单位满意的人才。方法采用问卷调查的方法对浙江省内有代表性的19家包含口腔医疗服务单位进行了调查,同时进行大学生就业心态调查问卷调查。结果医学生的就业心态出现多元化;毕业生不再一味追求高学历,更多的人选择了先就业后进修的道路。大多数用人单位着眼于提高医务人员的服务水平和质量,对毕业生的综合素质有了更高的要求。结论学校要尽力拓宽毕学生的就业渠道,提供更多的就业信息,树立面向基层的观念。     

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。     

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.     

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。     

两种牙科切削陶瓷材料可切削性的比较

目的　对作者研制的一种新型含钙云母玻璃陶瓷PMC Ⅰ型陶瓷的可切削性能与VitaMKⅡ陶瓷进行定量比较 ,探讨PMC Ⅰ型陶瓷强度与其可切削性的关系。方法　采用钻孔实验方法 ,测定A、B、C、D4组不同晶化处理的PMC Ⅰ型陶瓷及VitaMKⅡ陶瓷材料 60 0s的钻孔深度 ,同时测定4组PMC Ⅰ型陶瓷的 3点抗弯强度。结果　VitaMKⅡ的钻孔深度为 0 71mm ;4组PMC Ⅰ型陶瓷的钻孔深度分别为 0 88mm、1 40mm、0 40mm和 0 90mm。其中 ,B组样品与其余组别及VitaMKⅡ陶瓷的差异有显著性 (P <0 0 5)。 4组PMC Ⅰ型陶瓷的 3点抗弯强度分别为 1 37 7、2 1 0 2、1 1 8 0和 1 0 6 0MPa。结论　新型PMC Ⅰ型切削陶瓷的可切削性已能够满足临床要求