非免疫性唾液凝集素的研究进展

唾液中存在有许多物质可以凝集细菌,其中包括了非免疫性唾液凝集素,在口腔细菌的选择性清除与定植中起了重要的作用,近年来,对非免疫性凝集素的分子结构、在涎腺中的分布、生物学作用进行了较为深入的研究,本文就此进行综述。     

非免疫性唾液凝集素的研究进展

唾液中存在有许多物质可以凝集细菌，其中包括了非免疫性唾波凝集素，在口腔细菌的选择性清除与定植中起了重要的作用，近年来，对非免疫性凝集素的分子结构、在涎腺中的分布、生物学作用进行了较为深入的研究，本文就此进行综述。     

单克隆抗体对唾液凝集素介导的茸毛链球菌(S.sobrinus)聚集的影响

目的;用制备的抗茸毛链球菌主要表面蛋白的单克隆抗体作用于茸毛链球菌,体外观察单克隆抗体对唾液凝集素介导的细菌聚集的影响。方法;于紫外分光光度计上通过光密度值检测１ｈ内的细胞凝集情况。结果：单克隆抗体对唾液凝集素介导的茸毛链球菌之间的聚集有一定程度的影响,但作用不明显。     

牙周病原菌凝集机制的研究进展

牙菌斑是牙周病发生的始动因子,而细菌的黏附和凝集是牙菌斑形成的重要步骤.几乎所有牙周病原菌都具有相互凝集作用.以下就牙周病原菌凝集机制的研究进展做一综述.     

牙面生态膜与龋病(一)龋病学研究百年回顾与展望之三

牙面生态膜是细菌致龋活动场所。在上一世纪早期，人们开始对它进行了研究，60年代后形成高潮，近10余年更有新的突破。本篇主要介绍牙面生态膜的形成与发育，其核心是细菌的黏附现象，着重介绍了过去对细菌黏附现象中黏附的机理，唾液、糖和细菌本身在黏附活动中的作用。     

唾液对人口腔变形链球菌感染的影响

本文探讨外源性的变形链球菌(简称变链)菌株感染与唾液的特殊性质的关系,如:唾液诱导的细菌凝集,细菌对唾液包被表面的吸附等,这些都对细菌定居于口腔表面有重要意义。     

表面蛋白抗原P及其在变异链球菌生物膜形成中的作用

变异链球菌表面蛋白抗原(SPA)P是一类介导细菌黏附和生物膜形成的重要的黏附毒力因子,具有高度保守性.SPAP含有1 561个氨基酸残基,其线性结构氨基酸序列由前导肽区、N端、A区、V区、P区、C端和细胞壁锚着端组成.SPAP具有的淀粉样纤维特性,在细菌生物膜形成中十分重要.SPAP可与牙面获得性膜中的唾液成分结合,介导变异链球菌对牙面的初始黏附.SPAP通过分选酶转移肽共价结合到细菌胞壁表面,在内源性的表面蛋白释放酶作用下又可从细菌胞壁表面释放出来,从而使变异链球菌生物膜降解.本文就SPAP的结构、淀粉样纤维特性,变异链球菌黏附,SPAP各区在生物膜形成中的作用等研究进展作一综述,明确其生物学特性,对于龋病病因学和龋病防治的意义不言而喻.     

唾液富组蛋白在口腔疾病中的作用

唾液中有一组富含组氨酸的多肽,称为富组蛋白(histidine-rich protein,HRP或histatins)。它具有抑制羟基磷灰石晶体增长、抗菌、缓冲菌斑pH及凝集细菌等作用。与龋病、粘膜病、牙周病等口腔疾病的发生与治疗密切相关。     

口腔副溶血链球菌Fap1非依赖性菌毛的电镜观察及相关体外黏附实验

目的探讨副溶血链球菌表面Fap1非依赖性短菌毛结构的形态学表现及其在细菌黏附中的作用。方法通过插入置换法构建Fap1蛋白系列缺陷株以去除Fap1依赖性长菌毛结构，电镜下观察细菌表面结构的形态学变化：系列缺陷株的黏附功能通过唾液包被的羟基磷灰石体外黏附实验加以评价。结果所有Fap1蛋白形成缺陷株的菌体表面存在一种短菌毛结构，该种Fap1非依赖性菌毛垂直于细胞表面呈稀疏分布，长度不大于100nm；体外黏附实验表明仅存在短菌毛结构的系列缺陷株的黏附功能与野生株相比有明显下降．但仍保持19％～27％的黏附能力。结论副溶血链球菌表面Fap1非依赖性短菌毛在细菌的黏附活动中仅起一定辅助作用。     

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。     

Identification of the hydroxyapatite‐binding domain of salivary agglutinin

The salivary agglutinin glycoprotein (SAG) is present in saliva but is also part of the salivary pellicle, playing a seemingly paradoxical role with regard to bacterial homeostasis. On the one hand, SAG aggregates bacteria in solution, thereby preventing bacterial colonization. On the other hand, when bound to the tooth surface, SAG facilitates bacterial colonization and microbial growth. The protein part of SAG is predominantly composed of conserved scavenger receptor cysteine‐rich (SRCR) domains. Previously it was found that bacterial binding and aggregation is mediated via a single peptide loop, designated SRCRP2 (P2), within the SRCR domains of SAG. The current data suggest that the SRCR domains also harbour a hydroxyapatite (HA)‐binding moiety, SRCRP3 (P3). The observation that P2 and P3 individually play unique roles in the function of SAGs contributes to our understanding of the dual role of SAGs in bacterial binding. Inspired by the bacterial‐modulating capacity of SAGs, we created a P3–polyethylene glycol (PEG) conjugate. It was found that a P3 coating resulted in an increased antifouling activity of 20% compared with the uncoated surface in vitro. An additional PEG moiety resulted in an antifouling activity of up to 40% and 30% for Streptococcus mutans and Staphylococcus epidermidis, respectively.     

Salivary agglutinin/DMBT1SAG expression is up-regulated in the presence of salivary gland tumors

Salivary agglutinin (SAG) is encoded by the gene Deleted in Malignant Brain Tumors 1 (DMBT1) and represents the salivary variant of DMBT1 (DMBT1(SAG)). While SAG is a bona fide anti-caries factor, DMBT1 was proposed as a candidate tumor-suppressor for brain, digestive tract, and lung cancer. Though DMBT1(SAG) is expressed in the salivary glands, its expression in salivary gland tumors is unknown. Here we analyzed DMBT1(SAG) expression in 20 salivary gland tumors and 14 tumor-flanking tissues by immunohistochemistry. DMBT1(SAG) in salivary gland tumors resembles the changes of expression levels known from DMBT1 in tumors in other cancer types. Particularly, DMBT1(SAG) was up-regulated in 10/14 tumor-flanking tissues, and a strong staining of the luminal content in the tumor and/or the tumor-flanking tissue was observed in 14/20 cases. This suggests that, in addition to its role in caries defense, SAG may serve as a potential tumor indicator and/or tumor suppressor in salivary gland tissue.     

牙体充填材料表面粗糙度对常见口腔链球菌黏附力的影响

目的 采用原子力显微镜（AFM）检测常见口腔链球菌属与不同表面粗糙度的光固化复合树脂及玻璃离子水门汀（GIC）之间的黏附力。方法 将光固化复合树脂和GIC样本表面梯度抛光,根据最终表面粗糙度不同分为300、200、100和10 nm组,使用AFM观察其表面形貌。采用先锋菌（血链球菌、缓症链球菌）和致龋菌（变异链球菌、表兄链球菌）制作细菌改性探针,通过AFM获得力-距曲线测量细菌与树脂和GIC样本表面的黏附力。对材料表面粗糙度测量值进行方差分析,细菌黏附力进行Kruskal-Wallis非参数检验,同时采用Dunn’s进行组间两两比较,并对表面粗糙度与细菌黏附力进行相关性分析。结果 随材料表面粗糙度增加,细菌的黏附力增大,4种细菌的黏附力均在300 nm的材料表面达到最大值;在10和300 nm组的GIC表面,变异链球菌的黏附力由0.578 nN增加到2.876 nN。4种细菌在树脂表面的黏附力略大于GIC,先锋菌的黏附力略大于致龋菌,组间差异均在200和300 nm组时较明显。结论 材料表面粗糙度对细菌黏附力的影响较大,二者有明显的相关性;GIC对细菌的黏附性较复合树脂低;材料表面粗糙度对致龋菌的影响小于先锋菌。     

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。     

Quantitative analysis of the adhesion of cariogenic streptococci to orthodontic metal brackets

The aim of this study was to analyze the adhesion of cariogenic streptococci to orthodontic metal brackets in terms of the type of bacterial strains, the incubation time, and saliva coating. Two strains of Streptococcus mutans (S. mutans LM7 and S. mutans OMZ65) and two strains of S. sobrinus (S. sobrinus B13 and S. sobrinus 6715) were used. Twenty metal brackets were incubated with either unstimulated whole saliva or phosphate-buffered saline for two hours. The bacterial adhesion assays were then performed by incubating the tritium-labeled streptococci with saliva-coated or noncoated orthodontic brackets for three, six, or nine hours. The results showed a characteristic binding pattern according to the type of bacterial strains used. S. mutans OMZ65 showed the highest amount of adhesion, whereas S. sobrinus B13 showed the lowest amount of adhesion. Generally, an extended incubation time increased the adhesion of cariogenic streptococci, and the amount of adhesion was the highest after nine hours of incubation. The saliva coating did not significantly influence the adhesion of bacteria. However, this saliva-mediated adhesion differed according to incubation time. The saliva coating tended to gradually decrease the adhesion by the extended incubation time, compared with the noncoated controls. This study indicates that each strain of cariogenic streptococci has a characteristic adhesion pattern and the type of bacterial strain, the incubation time, and saliva influenced the adhesion.     

Quantitative determination of adhesion patterns of cariogenic streptococci to various orthodontic adhesives

OBJECTIVE: To investigate the adhesion of various cariogenic streptococci to orthodontic adhesives. MATERIALS AND METHODS: Five light-cure orthodontic adhesives (one fluoride-releasing composite, three non-fluoride-releasing composites, and one resin-modified glass ionomer cement) were used. The adhesive type, bacterial strain, incubation time, and saliva coating were studied. Thirty specimens of each adhesive were incubated with unstimulated whole saliva or phosphate-buffered saline for 2 hours. Binding assays were then performed by incubating tritium-labeled streptococci with the adhesives for 3 or 6 hours. RESULTS: The results showed a characteristic adhesion pattern according to the type of bacterial strains used. Streptococcus mutans LM7 showed the highest amount of adhesion, whereas S sobrinus B13 showed the lowest amount of adhesion. The cariogenic streptococci adhered to the glass ionomer significantly more than to the composites, whereas there was no significant difference in the adhesion amount among the four composites. The extended incubation time significantly increased bacterial adhesion. However, saliva coating did not significantly alter adhesion patterns of cariogenic streptococci. CONCLUSIONS: This study suggests that cariogenic streptococci can adhere diversely according to adhesive type and that the adhesion of the cariogenic streptococci is not influenced by its fluoride-releasing properties.     

银的抗菌性能及其在种植体表面的抗菌改性研究

种植体周围细菌黏附聚集导致的种植体周炎是种植体失败的重要原因。抑制种植体表面的细菌黏附和杀灭种植体周的细菌对防治种植体周炎具有重要意义。本文就银的抗菌性能及在种植体表面抗菌改性的研究进展作一综述。     

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。     

Effects of zinc and copper on adhesion and hemagglutination of Prevotella intermedia and Prevotella nigrescens

This study investigated the mechanism of protein attachment to the surface of the putative periodontal pathogens Prevotella intermedia and Prevotella nigrescens in artificial gingival crevicular fluid, and ways to increase protein attachment to the bacterial cells. The effects of cations on protein attachment, bacterial adhesion, and hemagglutination were examined, and cation-binding components on both bacterial species were identified. The presence of cations, especially zinc, copper and cerium, increased attachment of human serum proteins to both bacterial species. In contrast, the presence of hydrophobic inhibitors or sugars had little effect. Protein attachment was reduced by heat treatment of the bacterial cells. Pretreatment of bacteria with human serum proteins inhibited adhesion of both species to buccal epithelial cells and hemagglutination. These effects were enhanced by the presence of zinc and copper during pretreatment. Using a chelating column, specific zinc- and copper-binding proteins were identified on the surfaces of both bacterial species.