变形链球菌葡聚糖结合蛋白C基因特异片段在大肠杆菌中的表达

目的原核表达变形链球菌葡聚糖结合蛋白C基因(glucan-bindingproteinCgene,gbpC)特异片段。方法将克隆获得的约0.45kb的gbpC基因特异片段经EcoRⅠ/SalⅠ双酶切后,定向插入pGEX-4T-1中,构建pGEX-4T-1/gbpCE原核融合表达载体,转化感受态大肠杆菌DH5α,挑选阳性克隆,酶切及PCR鉴定后,异丙基硫代-β-D-半乳糖苷(isopropy1-β-D-thiogalactoside,IPTG)诱导表达融合蛋白GST-GbpCE,SDS-PAGE检测表达产物。结果在SDS-PAGE凝胶上出现一条新生蛋白质条带,其相对分子质量约为43000,与预计大小相符合。结论成功表达gbpC特异片段,获得了融合蛋白GST-GbpCE,可用于制备GbpC抗体。     

变形链球菌葡聚糖结合蛋白C基因特异片段的分子克隆

目的：克隆变形链球菌葡聚糖结合蛋白Ｃ基因（ｇｂｐＣ）编码序列的特异片段。方法：根据文献报道的ｇｂｐＣ序列设计并合成一对寡核苷酸引物,ＰＣＲ扩增位于ｇｂｐＣ编码序列１１０５～１５５４ｂｐ间的一段牧民片段,扩增产物经回收、酶切后,定向插入克隆载体ｐｕｃ１８中,连接产物转化感受态大肠杆菌ＤＨ５α,挑选阳性克隆,鉴定后进行序列测定。结果：测序结果与Ｓａｔｏ等报道的序列一致。结论：成功克隆了ｇｂｐＣ基因片段     

ADAM28基因原核表达载体的构建和在大肠杆菌中的融合表达

目的:利用消减杂交技术克隆出牙齿发育相关基因ADAM28。方法:本研究为构建ADAM28基因的原核表达载体,在大肠杆菌中诱导其表达并纯化出ADAM28蛋白;采用反转录-多聚酶链式反应(RT-PCR)扩增出ADAM28基因的蛋白编码序列,克隆到中间载体pMD18-TVector中产生pMD18-T-ADAM28,再经双酶切得到ADAM28片段定向克隆到pGEX-4T-1载体中,构建融合表达载体pGEX-4T-ADAM28;在大肠杆菌中利用IPTG进行诱导表达,得到GST-ADAM28融合蛋白,并经SDS-PAGE电泳初步纯化。结果:①成功构建融合表达载体pGEX-4T-ADAM28,并经酶切鉴定、PCR鉴定和测序验证显示插入的ADAM28序列正确,阅读框架完整,未发现突变。②得到初步纯化的GST-ADAM28融合蛋白。经IPTG诱导后出现一条约35.3×103的新蛋白带。结论:ADAM28基因编码蛋白质能够在原核细胞中表达并纯化,为进一步研究该蛋白质的功能打下基础。     

大鼠磨牙牙根发育相关基因mrp1的克隆及其原核表达载体的构建

目的:从大鼠磨牙胚组织中克隆大鼠磨牙牙根发育相关基因mrp1,构建原核融合表达载体,利用大肠杆菌表达其C端肽。方法:从生后 3dSD大鼠仔鼠磨牙胚中提取总mRNA,通过RT-PCR扩增出mrp1C端肽段基因并克隆进中间载体,然后将插入基因克隆入GST融合表达载体pGEX-4T-1,以大肠杆菌DH5α为宿主菌,在 28℃下进行IPTG诱导。结果:克隆载体序列酶切鉴定、序列测定完全正确;含重组质粒的工程菌经诱导后在SDS-PAGE上出现一条新生蛋白带,Mr为 36×103,与预期C端肽Mr大小一致,约占菌体总蛋白的 19%。结论:成功地鉴定了mrp1C端肽段基因,通过基因克隆构建了其原核表达载体pGEX-4T-mrp1,并在大肠杆菌中得到了高效表达。     

人成釉蛋白编码区cDNA的克隆和N端肽的融合表达

目的 :克隆人成釉蛋白 (Ameloblastin)编码区基因并原核表达其N端肽。方法 :抽提人牙胚总RNA ,用Oligo(dt)作引物逆转录合成人牙胚cDNAs,然后利用PCR方法 ,从cDNAs中扩增出人成釉蛋白编码区cDNA序列 ,将所得基因片段插入 pGEM -TEasy质粒载体 ,转化入大肠杆菌DH5α后挑选阳性克隆 ,提取重组质粒DNA ,通过限制性酶切和核苷酸序列测定鉴定阳性克隆。将所克隆序列的 5’端 5 5 8bp的片段连入原核表达载体 pGEX - 4T1并在大肠杆菌中诱导表达 ,SDS -PAGE分析。 结果 :克隆片段测序结果与GenBank数据库收录的序列一致 ,经诱导表达见Mr为 4 6× 10 3 的融合蛋白。结论 :克隆到人成釉蛋白编码区cDNA ,并在大肠杆菌中表达了人成釉蛋白N端肽     

小鼠重组釉蛋白32000多肽的原核表达和纯化

目的 在大肠杆菌中表达小鼠重组釉蛋白32 000多肽,为进一步制备抗鼠釉蛋白抗体和釉蛋白功能研究奠定基础.方法 利用聚合酶链反应(PCR)法扩增出编码小鼠釉蛋白32 000多肽的cDNA序列,将所得基因片段插入pGEM-T Easy质粒载体,转化大肠杆菌JM109后挑取阳性克隆,提取重组质粒DNA,并经酶切鉴定后将所克隆的序列312 bp片段连入原核表达载体pGEX-4T1,并于大肠杆菌BL21中诱导表达,行SDS聚丙烯酰胺凝胶电泳分析.结果 成功构建了重组表达载体pGEX-4T1-EN312,并经异丙基硫代半乳糖苷诱导后,可见相对分子质量(Mr)为47×103的融合蛋白.结论 利用pGEX-4T1-EN312-BL21体系成功获得了小鼠重组釉蛋白32 000多肽在大肠杆菌中的原核表达和初步纯化.     

人牙胚釉原蛋白成熟肽基因的克隆

目的:克隆人釉原蛋白成熟肽编码区基因片断,并构建含有该基因的重组表达质粒。方法:从引产胎儿牙胚组织中抽提总RNA,以Oligo(dt)为引物,逆转录合成牙胚cDNA利用PCR,从cDNA中扩增出人釉原蛋白成熟肽编码序列(约540bp),所得目的基因片断插入表达载体质粒PQE30,转化到大肠杆菌DH5α后挑选阳性克隆,抽提重组质粒DNA,通过PCR、酶切和核苷酸序列分析,鉴定阳性克隆。结果:样品质粒测序证实,质粒PQE30中插入的基因片段与人釉原蛋白成熟肽基因序列完全相同。结论:从人胚胎的牙胚组织中克隆到釉原蛋白成熟肽编码序列,成功构建含有人釉原蛋白成熟肽基因的重组表达质粒。     

变形链球菌乳酸脱氢酶基因及同源区的克隆和序列分析

目的：克隆变形链球菌乳酸脱氢酶基因(ldh)及其两侧同源区基因片段。方法：应用PCR技术扩增乳酸脱氢酶及其两端同源区序列片段，插入克隆载体pMD18-T中，转化大肠杆菌DH5α，Amp^ 抗性挑选阳性克隆，经酶切及PCR鉴定后进行序列测定。结果：PCR扩增产物特异；抗性筛选的4株菌落均为阳性克隆；用DNASIS将序列测定的结果与基因Bank中报道的序列对比分析，同源性为99．1％。结论：根据同源性分析的结果，可确定该克隆片段为变形链球菌乳酸脱氢酶及其两侧同源区序列。     

牙龈卟啉单胞菌精氨酸牙龈素催化结构域基因的克隆及其在大肠杆菌中的表达

目的 克隆牙龈卟啉单胞菌精氨酸牙龈素催化结构域（RgpAcd）基因,并将其置于大肠杆菌中作融合表
达。方法 利用PCR技术和基因重组技术,克隆牙龈卟啉单胞菌RgpAcd,然后插入中介载体pMD18-T中并测序鉴定。将目的基因片段插入原核表达载体pET-15b来构建表达质粒pET-15b/RgpAcd。重组原核表达质粒经酶切鉴定后转化大肠杆菌BL21感受态细胞,以异丙基硫代-β-D-半乳糖苷（IPTG）诱导表达融合蛋白。结果 核酸序列测定与分析的结果表明,克隆的1 476 bp基因序列与GenBank数据库中的序列呈现100%同源性;IPTG诱导后的菌体经SDS-聚丙烯酰胺凝胶电泳后有一个相对分子质量为5×104的融合表达蛋白产生。结论 本实验成功克隆了牙龈卟啉单胞菌RgpAcd基因,并在大肠杆菌中表达了RgpAcd蛋白,为进一步研制重组活载体疫苗奠定了基础。     

牙齿发育相关基因adam28多克隆抗体的制备及鉴定

目的制备及鉴定抗ADAM28的多克隆抗体。方法采用反转录-多聚酶链式反应(RT-PCR)扩增出adam28基因的蛋白编码区序列,克隆到中间载体pMD18-T Vector中,再经双酶切得到adam28片段定向克隆到pGEX-4T-1载体中,构建融合表达载体pGEX-4T-adam28,在大肠杆菌中用IPTG进行诱导表达,得到GST-ADAM28融合蛋白,经过初步纯化及SDS-PAGE电泳,在35300的新蛋白带处直接割胶,作为抗原免疫新西兰大白兔后获取抗体。结果成功构建融合表达载体pGEX-4T-adam28,得到初步纯化的GST-ADAM28融合蛋白,免疫兔子1个月后,获得免疫血清,盐析法纯化得到多克隆抗体。Western印迹结果显示所得到的抗体具有较高的特异性,ELISA分析证实其效价可达1∶16000。结论成功制备出高效价的抗ADAM28多克隆抗体,为进一步研究ADAM28在牙齿发育中的作用和表达分布奠定基础。     

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.     

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     

下颌角骨折治疗后并发症的临床分析

目的研究下颌角骨折治疗后并发症,分析原因并提出预防方法。方法回顾分析我院206例下颌角骨折患者的治疗及并发症情况,分颌间固定组62例,内固定组120例,颅颌绷带组24例。结果治疗后发生的并发症有骨感染4例,医源性损伤2例,牙合干扰3例,错牙合畸形2例,颞下颌关节功能紊乱病2例。结论下颌角骨折的治疗应首选坚强内固定,应选择正确的手术方案,加强术前、术后抗感染治疗及术后肌功能训练,对骨折线上的阻生齿应尽可能保留,以减少并发症。