应用原子力显微镜对口腔变异链球菌黏附机制的研究

原子力显微镜(AFM)是一种理想的探测细菌与生物材料之间基本相互作用力及研究微生态系统形态和力学的工具,被应用于包括口腔变异链球菌在内的多种微生物的形态及力学研究中.本文就AFM在口腔变异链球菌黏附研究中的应用及在相关黏附机制、黏附影响因素等方面的研究成果进行综述,总结阐述口腔变异链球菌黏附的分子生物学机制,为细菌黏附的研究提供力学基础及新思路.     

口腔微生物在充填材料上的黏附及其影响因素

继发龋、龈炎等牙体充填修复后的常见并发症与口腔微生物对充填材料表面的黏附进而形成菌斑有关。不同充填材料表面黏附的微生物数量、种类可能有所不同,这与微生物的生物学特性和材料的理化性质有关。本文综述了口腔微生物对充填材料表面的黏附机制及各种理化影响因素。     

含银无机抗菌剂加入树脂中对口腔常见细菌黏附影响的研究

目的检测含银硅铝酸盐无机抗菌剂对口腔常见细菌的作用效果,以及加入该抗菌剂的基托树脂表面的口腔常见细菌的黏附情况。方法将一定量细菌、真菌接种到含有适当比例含银硅铝酸盐无机抗菌剂的培养基中,检测该抗菌剂的抑菌情况;应用体外菌斑模型观察含有抗菌剂的聚甲基丙烯酸基托树脂表面的微生物黏附状况。结果含银无机抗菌剂在8%的质量分数内可以完全抑制口腔常见细菌的生长,在质量分数为1.25%和2.50%的情况下能够有效地抑制牙龈卟啉单胞菌和白假丝酵母菌的生长;但是在16 d的实验期内未能抑制细菌在材料表面的黏附。结论含银硅铝酸盐无机抗菌剂对口腔常见细菌有良好的抑菌效果,但是在聚甲基丙烯酸树脂材料中加入含银硅铝酸盐无机抗菌剂,没有表现出抑制细菌黏附的能力。     

口腔常见致病菌的表面疏水性分析

目的：分析测试几种口腔常见致病菌的细胞表面疏水性，为研究细菌非特异性黏附机制提供科学理论参数。方法：采用碳氢化合物黏着法测试细菌表面疏水性。结果：不同种类的细菌、同种细菌的不同菌株间疏水性均存在差异。每株细菌表面具有其相对稳定的参考值范围。结论：口腔细菌具有强弱不同的疏水作用。     

唾液凝集素研究进展

唾液凝集素是一种能与细菌作用的糖蛋白,在口腔中能介导多种细菌的凝集和黏附.近年来对唾液凝集素与细菌表面蛋白的研究已越来越深入,下面就唾液凝集素的生化特性及其在细菌凝集和黏附中的作用作一综述.     

不同复合树脂修复体表面粗糙度与菌斑黏附关系的研究

目的：研究复合树脂修复体表面粗糙度的不同对其表面细菌黏附程度的影响。方法：对3种不同复合树脂材料进行表面处理,使每一种材料相同地形成3种粗糙度。将不同粗糙度级的试件与口腔变形链球菌于体外培养,测定细菌黏附量。结果：随着粗糙度的降低,各树脂试件的菌斑黏附量均有明显下降;同一粗糙度实验组z350纳米树脂的菌斑黏附量较少。结论：表面粗糙度对细菌黏附有重要影响,即表面越粗糙,菌斑形成越多。相同处理条件下,Z350纳米树脂的菌斑黏附量少。     

信号传导在口腔细菌特异性黏附中的引导作用

黏附是细菌定居和致病的基础。在黏附过程中,存在着复杂的细菌与获得性膜以及细菌与细菌之间的信号传导。下面就细菌黏附机制、口腔细菌信号传导的类型以及信号传导在口腔细菌黏附中的作用等初步探讨信号传导与口腔细菌特异性黏附之间的关系,为控制口腔细菌生物膜的形成提供一种新的思路。     

格氏链球菌表面黏附蛋白的研究进展

格氏链球菌细胞表面含有多种黏附蛋白,使细菌较容易的黏附在宿主牙齿和黏膜等组织表面,从而使格氏链球菌成为牙菌斑生物膜初始形成时起重要作用的一类细菌,与龋病和牙周病等口腔常见疾病的发生密切相关。本文就目前研究较多的格氏链球菌表面黏附蛋白的结构及其与宿主和其他微生物之间的关系作一综述。     

烤瓷表面抛光和上釉对其表面粗糙度及细菌黏附的影响

目的比较不同抛光方法对烤瓷表面粗糙度的影响,以及不同粗糙度烤瓷表面对口腔变异链球菌黏附的影响。方法采用原子力显微镜测量不同抛光方法对瓷表面粗糙度的影响,并通过细菌实验观察不同粗糙度的瓷表面对细菌黏附的影响。结果用抛光膏抛光或者上釉后,瓷面平整且有光泽。无论是表面粗糙度还是表面黏附的细菌数,橡皮轮组都大于抛光膏组和上釉组（P<0.05）。结论建议调改过的瓷表面进行抛光膏抛光或上釉以恢复瓷表面的光滑度和减少口腔致龋菌的黏附。     

3种口腔修复金属材料表面白色念珠菌早期黏附的的实验研究

目的:比较镍铬合金、钴铬合金和纯钛3种口腔修复常用的金属表面对白色念珠菌早期黏附的影响.方法:在对镍铬合金、钻铬合金和纯钛3种金属试样表面能测试的基础上,进行体外白色念珠菌黏附实验.采用菌落形成计数法测定试样表面在1、3、24 h的细菌黏附量,采用荧光染色法观察材料表面死菌与活菌比例.结果:镍铬合金、钴铬合金、纯钛的表...     

变形链球菌牙面粘附唾液受体的筛选和纯化

目的：筛选和纯化变形链球菌血清型ｃ（简称变链）的牙面粘附唾液受体。方法：用全唾液包被羟基磷灰石形成实验性获得性膜（ＳＡＰ）,后用１ｍｏｌ／Ｌ ＮａＣｌ和０．５ｍｏｌ／Ｌ磷酸盐缓冲液分步洗脱,再用Ｓｅｐｈａｄｅｘ Ｇ７５分子筛层析和ＤＥＡＥ－Ｓｅｐｈａｄｅｘ Ａ２５离子交换层析对ＳＡＰ组分进行分离纯化,用细菌粘附实验和细菌粘附竞争抑制实验筛选受体,经聚丙烯酰胺凝胶电泳,等电聚焦电泳,淀粉酶活性测定等     

不同粘接剂重复粘接正畸托槽的剪切强度研究

托槽脱落问题始终困扰着临床正畸医生,而托槽脱落率与粘接剂的理化性能及重复粘接后的抗剪切强度直接相关。本实验选用两种不同粘接剂：京津釉质粘合剂和单组分粘接剂,在模拟临床应用的实验条件下,比较重复粘接的抗剪切强度,并评估托槽脱落后牙面上残留的粘接剂指数(adhesive remnant indexes,ARI),为临床合理选择粘接剂重复粘接托槽提供参考。     

IgSF类细胞粘附分子与腺样囊性癌侵袭和转移的关系

目的 研究免疫球蛋白超家族(immunoglobulin superfamily，IgSF)类细胞粘附分子在涎腺腺样囊性癌中的表达及与淋巴结转移的关系。方法采用免疫组化方法对36例涎腺腺样囊性癌细胞间粘附分子-1(Intercellular Adhesion Molecule-1，ICAM-1)、血管间细胞粘附分子-1(Vascular Cell Adhesion Molecule-1．VCAM-1)和神经细胞粘附分子(Neural Cell Adhesion Molecule，NCAM)的表达进行研究。结果 ICAM-1，VCAM-1和NCAM的表达率分别是72．2％，63．9％和22．2％，表达程度与肿瘤的分型相关。ICAM-1，VCAM-1与淋巴结的转移及复发呈正相关：NCAM与淋巴结的转移及复发负相关。结论 ICAM-1和VCAM-1可能通过与相应的配体作用而使肿瘤发生侵袭转移；NCAM则通过调控细胞的增殖是一种具有抗侵袭力的粘附分子。     

Treponema denticola improves adhesive capacities of Porphyromonas gingivalis

Porphyromonas gingivalis, an important etiological agent of periodontal disease, is frequently found associated with Treponema denticola, an anaerobic spirochete, in pathogenic biofilms. However, interactions between these two bacteria are not well understood at the molecular level. In this study, we seek to link the influence of T. denticola on the expression of P. gingivalis proteases with its capacities to adhere and to form biofilms. The P. gingivalis genes encoding Arg‐gingipain A (RgpA), Lys‐gingipain (Kgp), and hemagglutinin A (HagA) were more strongly expressed after incubation with T. denticola compared with P. gingivalis alone. The amounts of the three resulting proteins, all of which contain hemagglutinin adhesion domains, were increased in culture supernatants. Moreover, incubation of P. gingivalis with T. denticola promoted static and dynamic biofilm formation, primarily via a time‐dependent enhancement of P. gingivalis adhesion capacities on bacterial partners such as Streptococcus gordonii. Adhesion of P. gingivalis to human cells was also increased. These results showed that interactions of P. gingivalis with other bacterial species, such as T. denticola, induce increased adhesive capacities on various substrata by hemagglutinin adhesion domain‐containing proteins.     

牙本质黏结界面的微渗漏与纳米渗漏

目的：观察牙本质黏结界面微渗漏与纳米渗漏,探讨两者的关系。方法：在离体人磨牙的颊、舌侧颈部制备盒形单面洞（直径3mm,洞深2mm）,将牙分为2组,每组5个牙。对2组牙的窝洞分别应用黏结剂Single Bond、Clearfil SE Bond,然后充填复合树脂并光照固化。所有牙齿进行冷热循环5000次,之后在牙齿表面涂指甲油。将牙齿浸泡于500g/L氨化硝酸银液（pH8.0）中,24h后再浸泡于显影液中8h。随后将牙纵向剖开,暴露充填物剖面,在体视显微、扫描电镜下观察剖面充填物龈缘渗漏情况。结果：所有牙剖面修复体龈缘均存在程度不同的微渗漏,有微渗漏的黏结界面处并未发现因黏结原因所造成的裂缝或微裂隙,但在混合层内观察到纳米渗漏。结论：牙本质黏结界面的微渗漏染色不一定因界面裂缝所致,界面无裂缝的纳米渗漏同样可造成微渗漏染色。     

Expression of IgSF in salivary adenoid cystic carcinoma and its relationship with invasion and metastasis

BACKGROUND: The aim of the present work was to study the potential effect of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and neural cell adhesion molecule (NCAM) of immunoglobulin superfamily on the invasion and metastasis of salivary adenoid cystic carcinoma (SACC). METHOD: The expressions of ICAM-1, VCAM-1 and NCAM of forty cases with SACC were examined by immunohistochemical methods using respective kits. RESULTS: A significant relation showed between the expression level and histological differentiation, expression of ICAM-1 and VCAM-1 in solid SACC was greatly increased compared with NCAM; SACC with metastatic lymph node or local recurrence displayed significant relationship to the up-regulation of ICAM-1 and VCAM-1, and to the down-regulation of NCAM. CONCLUSIONS: It is proposed that ICAM-1 and VCAM-1 may play a role in the invasion and metastasis of SACC. NCAM may be an invasion-resistant adhesion molecule.     

Adhesion of Streptococcus rattus and Streptococcus mutans to metal surfaces

Abstract – The adhesion of Streptococcus rattus BHT and Streptococcus mutans IB to metal specimens of amalgam, silver, tin and copper was studied using (6-³H)thymidine labeled cells. In the standard assay the metal specimens were suspended by a nylon thread in an adhesion solution containing a chemically defined bacterial growth medium (FMC), sucrose, and radiolabeled bacteria, Maximum amounts of adhering bacteria were obtained after about 100 min of incubation. Saturation of the metal specimens with bacteria was not observed. Both strains also adhered in the absence of sucrose, indicating that glucan formation was not necessary for adhesion. However, in the presence of glucose, adhesion was only 26–45% of that observed in the presence of equimolar sucrose. Sucrose-dependent stimulation of adhesion seemed to be due to increased cell-to-cell adhesion capacity. Isolated radiolabeled water-insoluble and watersoluble polysaccharides produced from sucrose by S. rattus BHT were not adsorbed to the metal surfaces.     

口腔螺旋体的胶原结合蛋白

目的 研究口腔螺旋体胶原结合蛋白的致病作用。方法 用免疫印迹、免疫金标电 体外粘附实验等方法分析了口腔螺旋体胶原结合蛋白的性质及其在菌细胞表面的定位。结果 Ｔｒｅｐｏｎｅｍａ ｄｅｎｔｉｃｏｌａ菌细胞外膜上有２７０００Ⅴ型,Ｔｒｅｐｏｎｅｍａ ｓｏｃｒａｎｓｋｉｉ菌有９５０００Ⅳ型和１１０００Ⅰ型,Ｔｒｅｐｏｎｅｍａ ｍｅｄｉｕｍ有９５０００Ⅳ型胶原结合蛋白;Ｔｄ和Ｔｓ可粘附于Ⅳ型胶原表面,而Ｔｍ     

An estimation of the strength of attachment of subgingival calculus to extracted teeth

Abstract The approximate shear bond strength of subgingival calculus was measured on freshly extracted teeth. The experimental method was validated on polycarboxylate controls. The object was to specify a suitable upper limit for periodontal dressing adhesion, and a level of 4.0MN/m² is suggested by these results     

影响成骨细胞在种植体表面黏附的因素

种植体与骨组织形成骨结合是种植体成功的前提。而成骨细胞在种植体表面的黏附作为成骨细胞与种植体作用的第一期,对于形成良好的骨结合界面至关重要。本文综述了影响成骨细胞在种植体表面黏附的因素。