牙龈卟啉单胞菌与动脉粥样硬化发病的关系

慢性牙周炎是心血管疾病特别是冠心病的危险因素之一,然而其相关的生物学基础目前尚不清楚.笔者下面就与慢性牙周炎关系最为密切的牙龈卟啉单胞菌与动脉粥样硬化的相关性和牙龈卟啉单胞菌致动脉粥样硬化的可能机制以及Toll样受体在牙龈卟啉单胞菌与动脉粥样硬化相关性中的作用作一综述.     

牙龈卟啉单胞菌与Toll样受体的研究进展

牙龈卟啉单胞菌是公认的牙周致病菌，能分泌大量的毒力因子。Toll样受体是一种识别病原相关分子模式的跨膜蛋白，在机体的先天性免疫中具有重要的作用。本文就近年来牙龈卟啉单胞菌与Toll样受体的研究进展作一综述。     

不同牙周状况龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布

目的 分析中国牙周健康者和慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌和福赛斯坦纳菌的分布情况,探讨两种细菌在中国慢性牙周炎患者中的分布及其致病机理.方法 收集65例牙周健康者、62例慢性牙周炎患者的龈下菌斑,采用16S rRNA PCR方法检测牙龈卟啉单胞菌和福赛斯坦纳菌的分布.结果 牙周健康者牙龈卟啉单胞菌和福赛斯坦纳菌的检出率分别是21.6%、12.3%,慢性牙周炎患者病变位点两菌检出率分别为74.2%、58.1%,牙周炎健康位点两菌的检出率分别是22.6%、4.8%.牙周炎病变位点两种细菌的检出率均明显高于牙周健康者和牙周炎健康位点(P＜0.001);福赛斯坦纳菌在牙周健康者中的检出率高于牙周炎健康位点(P＜0.05);牙周健康者和牙周炎健康位点牙龈卟啉单胞菌的检出率没有差异.慢性牙周炎患者两菌联合检出率为51.6%.结论 牙龈卟啉单胞菌、福赛斯坦纳菌以及两种细菌联合感染与牙周炎密切相关.     

牙龈卟啉菌蛋白酶的研究进展

革兰氏阴性厌氧菌牙龈卟啉菌和牙周炎病因密切相关,生物化学和分子生物学的进展表明牙龈卟啉菌可合成多种蛋白酶,蛋白酶是细菌重要的毒力因子,具有复杂的生理功能。本文简述了牙龈卟啉菌蛋白酶的生物学作用及其在牙周炎组织破坏中的影响。     

应用实时荧光定量PCR定量检测慢性牙周炎患者龈下菌斑中牙龈卟啉单胞菌

目的 检测慢性牙周交患者和牙周健康人龈下菌斑中牙龈卟啉单胞菌、总菌量和牙龈卟啉单胞菌所占比例,探讨牙龈卟啉单胞菌与牙周炎发生发展的关系.方法 采集经常规PCR方法检测牙龈卟啉单胞菌为阳性的76例慢性牙周炎患者和25例牙周健康者的龈下菌斑,应用TaqMan实时荧光定量PCR方法定量检测样本中牙龈卟啉单胞菌、总菌量;构建含有牙龈卟啉单胞菌和真细菌扩增片断的重组质粒,建立定量标准.结果 本研究设计的引物和探针具有良好的特异性及敏感性.病变位点龈下菌斑中牙龈卟啉单胞菌数量和总菌量均比健康位点高(P<0.001),两组位点牙龈卟啉单胞菌在菌斑中的比例没有差异(P>0.05);细菌数量与探诊深度间存在显著正相关关系(P<0.001),不同的探诊深度牙龈卟啉单胞菌所占比例无统计学差异(P>0.05).结论 龈下菌斑中牙龈卟啉单胞菌的数量水平及细菌总量与牙周状况、牙周炎发展有密切关系,实时荧光定量PCR对牙周病学研究具有广泛的应用前景.     

牙龈卟啉单胞菌在龈下菌斑和颊黏膜中的检测

目的　检测牙周健康者及牙周炎患者在颊黏膜和龈下菌斑中牙龈卟啉单胞菌的阳性率,探讨其与牙周炎发生和发展的关系。方法　选取40例牙周健康者和39例慢性牙周炎患者,分别收集颊黏膜和龈下菌斑样本,提取细菌DNA,设计细菌通用引物和牙龈卟啉单胞菌的特异引物用于PCR扩增,检测牙龈卟啉单胞菌的阳性率。结果　牙周健康组菌斑样本和颊黏膜样本牙龈卟啉单胞菌的阳性率分别为37·5%和32·5%,而牙周炎组菌斑样本和颊黏膜样本牙龈卟啉单胞菌的阳性率分别为69·23%和46·15%。牙周炎组菌斑的牙龈卟啉单胞菌阳性率高于牙周健康组,颊黏膜的牙龈卟啉单胞菌阳性率在组间无统计学差异;牙周炎组菌斑牙龈卟啉单胞菌阳性率高于颊黏膜, 牙周健康组两部位阳性率无统计学差异。结论　牙龈卟啉单胞菌除在菌斑中有高检出率外,在颊黏膜中也有较高的检出率,提示颊黏膜也是牙周细菌在口腔定植的重要部位,牙龈卟啉单胞菌也可在健康人群中检出,提示其有可能是口腔内固有菌群之一。     

牙龈卟啉菌、中间普氏菌的分离、培养和鉴定

目的：采用厌氧培养和鉴定技术，分离牙周炎患者龈下菌斑中的牙龈卟啉菌和中间普氏菌。方法：采集牙周炎患者的龈下菌斑，厌氧培养，分离产黑色素菌。经长波长紫外灯观察，各种生化分析和间接免疫荧光染色，分离和鉴定牙龈卟啉菌，中间普氏菌。结果：在受检的33例牙周炎患者中，24例患者检出了牙龈卟啉菌，总检出率为72．77％，共分离了79株。18例患者检出了中间普氏菌，总检出率为54．54％。共分离了32株。结论：厌氧培养，生化反应鉴定技术的发展，使牙龈卟啉菌和中间普氏菌的分离与培养准确可靠，为今后在分子水平上了解各菌株的致病机理打下了基础。     

慢性牙周炎患者牙周袋内硫化物水平与厌氧细菌分布的相关性研究

目的:探讨慢性牙周炎患者牙周袋内硫化物水平(sulfide levels in periodontal pockets,SUL)与牙龈卟啉单胞菌、中间普氏菌、伴放线放线杆菌分布的相关性.方法:用perio2000 system金刚探针牙周诊断仪测定慢性牙周炎患者SUL,采用PCR方法检测龈下菌斑中牙龈卟啉单胞菌、中间普氏菌和伴放线放线杆菌.结果:慢性牙周炎患者随着牙周袋内SUL浓度的增加牙龈卟啉单胞菌、中间普氏菌的检出率逐渐增加,相关系数分别为0.812和0.651(P<0.05);SUL阳性位点与阴性位点中牙龈卟啉单胞菌的检出率分别是为85.6%、26.7%,中间普氏菌的检出率分别为95.2%、53.3%.SUL阳性位点中牙龈卟啉单胞菌和中间普氏菌的检出率明显高于SUL阴性位点;在80.9%的SUL阳性位点中牙龈卟啉单胞菌与中间普氏菌共存.SUL阳性位点与阴性位点均未检出伴放线放线杆菌.结论:慢性牙周炎患者SUL与牙龈卟啉单胞菌和中间普氏菌分布关系较为密切.     

牙龈卟啉单胞菌牙龈素在牙周炎症过程中的作用及其机制

牙周炎是口腔临床实践中最为常见的疾病之一。牙龈卟啉单胞菌与牙周炎密切相关,牙龈卟啉单胞菌表面的牙龈素(gingipains)、菌毛和脂多糖被认为是其最重要的毒力因子,是近年来牙周炎机制研究的热点,引起研究者的广泛关注。本文结合近年来的研究进展,就牙龈卟啉单胞菌gingipains的结构、引起牙周炎症的机制和所涉及的信号通路作一综述。     

大鼠实验性牙周炎中牙龈卟啉单胞菌rgpB和kgp变化的研究

目的:通过建立大鼠实验性牙周炎模型,检测不同时段大鼠上颌第一磨牙龈下人工定植的牙龈卟啉单胞菌、牙龈素rgpB和kgp相对含量的改变,动态观察牙周炎发展不同阶段牙龈卟啉单胞菌致病基因的变化。方法:选择6周的成年雄性大鼠13只,应用钢丝结扎法和细菌种植法建立大鼠实验性牙周炎模型。分别在4周和8周取上颌第一磨牙龈下菌斑,提取细菌DNA,应用PCR方法进行牙龈卟啉单胞菌、牙龈素基因rgpB和kgp特异引物扩增,应用SPSS13.0统计软件,分析大鼠牙周炎不同时段rgpB和kgp的相对变化。结果:大鼠实验性牙周炎模型,龈下菌斑中牙龈卟啉单胞菌的相对含量实验组明显高于对照组,8周组高于4周组;实验组牙龈卟啉单胞菌牙龈素rgpB和kgp明显高于对照组,4周组和8周组rgpB和kgp相对含量无显著性差异。结论:rgpB基因和kgp基因与牙周炎的致病性有关而与牙周炎的严重程度可能无直接相关。     

Immunohistochemical expression of TLR-4 in temporomandibular joint dysfunction

Objective Toll-like receptor 4 (TLR-4) is a transmembrane protein involved in the innate immune system and has been implicated in the pathogenesis of temporomandibular joint dysfunction (TMD). The purpose of this study was to histologically examine the level of expression of TLR-4 relative to severity of TMD.

Methods Thirty-one human TMJ disc samples were immunostained for TLR-4 and evaluated for intensity of stain. Among the samples, 8 were control samples, 16 were from patients with anterior disc displacement with reduction (ADDwR), and 7 were from patients with anterior disc displacement without reduction (ADDwoR).

Results There was no statistically significant difference in intensity of stain between groupings (p = 0.673).

Conclusions The results indicate a negative correlation between TMD and the expression of TLR-4.     

LPS promotes pre-osteoclast activity by up-regulating CXCR4 via TLR-4

Lipopolysaccharide (LPS) has been shown to be a prominent pathogenic factor in inflammatory bone loss. However, knowledge of the mechanisms involved is limited. The role of the SDF-1/CXCR4 (Stromal-derived factor-1 and its unique chemokine receptor) axis in LPS-induced bone loss has not been studied. The aim of this study was to investigate the role of the SDF-1/CXCR4 axis in LPS-stimulated inflammatory bone loss. The results show that LPS does not influence the expression of SDF-1/CXCR4 in osteoblasts, but up-regulates the expression of CXCR4 in pre-osteoclasts via Toll-like receptor 4, which subsequently enhances pre-osteoclast migration. Moreover, LPS promoted RANKL-induced osteoclast differentiation partially through CXCR4 up-regulation. In conclusion, the present study demonstrated, for the first time, that the up-regulated expression of CXCR4 in pre-osteoclasts by LPS stimulation is involved in LPS-induced bone resorption.     

Trigeminal nociceptors express TLR-4 and CD14: a mechanism for pain due to infection

Although certain bacterial species appear to be risk factors for pain due to odontogenic infections, comparatively little is known about the potential mechanisms mediating this effect. In this study, we tested the hypothesis that trigeminal nociceptive neurons express the TLR4 or CD14 receptors, thus enabling sensory neurons to detect and respond to tissue levels of bacterial substances such as lipopolysaccharide (LPS). Immunohistochemical analyses of human and rat trigeminal neurons demonstrated that a capsaicin-sensitive subclass of nociceptors (defined by expression of TRPV1, a capsaicin receptor) expresses both TLR4 and CD14. Moreover, human dental pulp collected from patients with caries lesions demonstrated co-localization of TLR4 and CD14, with markers of peripheral sensory neurons. Collectively, these studies indicate that the capsaicin-sensitive subclass of trigeminal nociceptors expresses TLR4 and CD14. These results indicate that pain due to bacterial infections may result, in part, from direct activation of nociceptors by bacterial products such as LPS.     

Orthodontic cell stress modifies proinflammatory cytokine expression in human PDL cells and induces immunomodulatory effects via TLR-4 signaling in vitro

Clinical Oral Investigations - Biomechanical orthodontics loading of the periodontium initiates a cascade of inflammatory signaling events that induce periodontal remodeling and finally facilitate...     

Mood and malignancy: head and neck cancer and depression

Head and neck cancer patients have been reported to show high rates of depression. However, it is important to differentiate between depressive symptoms and a depressive disorder. This review critically examines the relationship between head and neck cancer and depression. There appears to be little evidence for depression leading to an increased risk of developing cancer and although depressive symptoms in head and neck cancer patients are common, very few studies have investigated depressive disorders. The studies that investigated the incidence of a comorbid depressive disorder report a prevalence very close to that of the general population, implying that major depression is not a normal response to cancer. Finally, the evidence suggests that comorbidity of depression with cancer has a negative impact on morbidity and mortality. Both psychosocial and biological factors could account for this. Dysregulation of the stress hormone axis and increased inflammation are common in depressive disorders and have been suggested as underlying pathological mechanisms and are both markers of poor prognosis in cancer. This evidence suggests that a relatively small number of patients develop a depressive disorder following a diagnosis of cancer, but for those that do it may have a substantial impact on their prognosis.     

低氧和自噬与肿瘤的发生发展

自噬作为真核生物的一种应激调控机制,既可以促进肿瘤的发生发展,又可以抑制肿瘤的增殖。在肿瘤局部低氧的微环境下,低氧诱导因子-1α、哺乳动物雷帕霉素靶蛋白信号转导通路抑制、内质网应激均可促进自噬的发生。在肿瘤快速地发生发展过程中,肿瘤的糖代谢功能增强、活性氧族增多、窖蛋白1下调以及上皮间质转化的激活均诱导了自噬的发生并促进肿瘤的局部浸润、侵袭转移和耐药,因此,抑制自噬可能为肿瘤治疗提供一种新的策略。     

Survey of Australian and New Zealand Oral and Maxillofacial Surgery trainees and recent specialists--education and experience

This study examined the demographic characteristics, educational background and attitudes toward training of all recent OMS specialists and all current trainees in Australia and New Zealand in 1996. The early nineties is a key period as it marks the transition from an essentially dentally based speciality (85% dental degree in 1990); to recent specialists with an increasing number with both medical and dental degrees (33% dual degree 1990-1996); to predominantly dual degree training (84.4% dual in 1996). Current trainees had more extensive experience in pathology, preprosthetic and reconstructive surgery. They were also strongly critical of the length and cost of training.