渐进性咬合紊乱对髁突软骨I型胶原表达的影响

目的:研究渐进性咬合紊乱对髁突软骨I型胶原表达变化的影响和意义。方法:用兔子口内造成渐进性咬合紊乱动物模型,用定量免疫组化染色法观察髁突软骨I型胶原的表达变化。结果:与对照组相比,实验组纤维层和增殖层表达增强,肥大层出现异常表达。在实验期内,实验组髁突大多数部位,纤维层和肥大层的表达有降低趋势,增殖层则持续增强。结论:渐进性咬合紊乱可以导致兔髁突软骨退行性变,髁突纤维层和增殖层软骨细胞I型胶原高表达,肥大层异常表达,软骨趋于纤维化或骨化。     

生长期兔颞下颌关节盘前移位后髁突软骨胶原表达的变化

目的:建立生长期兔颞下颌关节不可复性关节盘前移位动物模型,检测髁突软骨内Ⅱ型胶原和X型胶原的表达,探讨青少年颞下颌关节盘不可复性前移位与髁突软骨内成骨的关系,及其与下颌骨发育不对称畸形之间存在相关性的机制.方法:取生长期新西兰大白兔40只,右侧颞下颌关节手术建立不可复性关节盘前移位模型,左侧行假手术作为对照.实验动物于建模后24 h、1、4、8、12周分组处死取材.通过免疫组织化学方法检测髁突软骨组织内Ⅱ型胶原和X型胶原在蛋白水平的表达,采用PASW statistics 18.0软件包对每组样本实验侧和对照侧进行配对t检验.结果:Ⅱ型胶原在盘移位后24h、1、4、8周时与对照侧均无显著差异,12周时较对照侧表达升高(P＜0.05).X型胶原在盘移位后24 h(P＜0.01)、1周(P＜0.01)、4周(P＜0.05)时较对照侧显著降低,8周、12周时实验侧与对照侧间无显著差异.结论:不可复性关节盘前移位对兔髁突软骨内成骨过程造成干扰,这种影响可能是单侧颞下颌关节盘前移位后患侧下颌支高度不足和下颌骨不对称畸形的重要原因.     

下颌前伸后髁突软骨成熟层内Ⅹ型胶原的表达

目的 :检测下颌骨前伸条件下 ,大鼠髁突内Ⅹ型胶原的表达 ,从而论证髁突新骨的形成状况。方法 :10 0只同源雌性大鼠分成 5组实验组及 5组对照组 ,实验组动物戴用统一规格的咬合前导矫正器 ,各实验组及相应对照组动物分别在实验的第 3、7、14、2 1及 30d处死。应用分子原位杂交及免疫组织化学技术对髁突软骨成熟层内的Ⅹ型胶原mRNA及其蛋白的表达进行评价。结果 :实验组 ,特别是 2 1d组动物其髁突软骨成熟层细胞内有强烈的mRNA染点 :免疫荧光分析则在相应部位发现有剧烈的荧光闪点。对照组该产物表达不明显。结论 :髁突软骨成熟层细胞内Ⅹ型胶原表达提示功能性矫正器引发的下颌前伸能刺激髁突的新骨形成。     

渐进性咬合紊乱对髁突软骨Ⅰ型胶原表达的影响

[摘要]目的：研究渐进性咬合紊乱对髁突软骨Ⅰ型胶原表达变化的影响和意义。方法：用兔子口内造成渐进性咬合紊乱动物模型，用定量免疫组化染色法观察髁突软骨Ⅰ型胶原的表达变化。结果：与对照组相比，实验组纤维层和增殖层表达增强，肥大层出现异常表达。在实验期内，实验组髁突大多数部位，纤维层和肥大层的表达有降低趋势，增殖层则持续增强。结论：渐进性咬合紊乱可以导致兔髁突软骨退行性变，髁突纤维层和增殖层软骨细胞Ⅰ型胶原高表达，肥大层异常表达，软骨趋于纤维化或骨化。     

咬合紊乱对髁突软骨Ⅲ型胶原表达影响的定量研究

目的:研究渐进性咬合紊乱对髁突软骨Ⅲ型胶原表达变化的影响和意义。方法:在新西兰兔口内造成渐进性咬合紊乱,用定量免疫组化染色法观察髁突软骨Ⅲ型胶原的表达变化。结果:与对照组相比,实验组髁突软骨出现Ⅲ型胶原异常表达,并在实验期内持续增高。结论:渐进性咬合紊乱导致髁突软骨退行性变,退变软骨全层出现Ⅲ型胶原异常表达,表明软骨细胞表型发生变化。     

下颌垂直向功能性移位后髁突软骨的形态学及组织学改建

目的:通过诱发大鼠下颌骨垂直向功能性移位,阐明这一方向上的位移在髁突改建中的作用.方法:5周龄雌性SD大鼠40只,随机分为实验组和对照组,实验组大鼠佩戴上颌后牙(牙合)垫,使下颌骨发生垂直向功能性移位.实验组大鼠进一步分为4组,每组5只,分别在佩戴袷垫后第3、6、9、12天处死.采用组织形态学测量及AB-PAS染色,定量分析髁突的形态及软骨的组织学变化.采用SPSS11.0软件包对对照组和实验组的各项指标进行统计学分析.结果:下颌垂直向功能性移位后12d,髁突高度较对照组显著增加,前斜面更倾斜;髁突后上区前成软骨细胞及成软骨细胞层厚度在实验第3～6天无明显差异,第9天开始出现显著变化,实验组较对照组显著增厚,这种变化持续到实验第12天;肥大软骨细胞层厚度在实验第3、9、12天,实验组与对照组无显著差异,在实验第6天较对照组显著减少,间充质细胞层变化不大.结论:下颌垂直向功能性移位可致髁突高度增加、前斜面更倾斜,髁突软骨厚度的增加是髁突高度增加的组织学基础,垂直向移位也是构成功能性矫治器促进下颌骨发育的重要方面.     

下颌前伸后髁突软骨成熟层内X型胶原的表达

目的：检测下颌骨前伸条件下,大鼠髁突内Ｘ型胶原的表达,从而论证髁突新骨的形成状况。方法：１００只同源雌性大鼠５组实验组及５组对照组,实验组动物戴用统一规格的咬合前导矫正器,各实验组及相应对照组动物分别在实验的第３、７、１４、２１及３０ｄ处死。应用分子原位杂交及免疫组织化学技术对髁突软骨成熟慨内的Ｘ型胶原ｍＲＮＡ及其蛋白的表达进行评价。结果：实验组,特别是２１ｄ组动物其髁突软骨成熟层细胞内有强烈的Ｍ     

颞下颌关节盘前移位后髁突软骨细胞基质基因表达的变化

目的　探讨颞下颌关节盘前移位后髁突软骨细胞基质基因表达的变化。方法　建立40只大白兔颞下颌关节盘前移位动物模型,用地高辛标记cRNA探针原位杂交技术,检测术后不同病变时期髁突软骨细胞Ⅱ型胶原和蛋白多糖聚合体基因表达的改变。结果　正常髁突的增殖层深层、肥大层和钙化层细胞胞浆内可见大量Ⅱ型胶原和蛋白多糖聚合体mRNA表达。术后1周蛋白多糖聚合体开始下调,至2周达低谷,6周后恢复至正常水平。Ⅱ型胶原4周后开始持续下降,其表达下降程度较蛋白多糖聚合体显著,8周后逐渐恢复正常。结论　关节盘前移位后髁突软骨的基质基因表达发生有序、协调的变化,这种变化意味着适应性改建的启动。     

FAM20C在小鼠下颌髁突发育过程中的时空表达

目的 观察小鼠髁突发育过程的不同阶段,FAM20C在髁突软骨中的时空表达特点,试探究其在小鼠髁突发育过程中的可能作用机制。方法 苏木精-伊红(HE)染色和改良番红O-固绿染色观察胚胎17.5 d和出生后0、7、21 d 4组小鼠髁突软骨及软骨下骨的形态学变化。免疫组化染色观察相应时间点FAM20C在小鼠髁突软骨组织中的定位及表达。测量FAM20C阳性表达的平均光密度值,并进行单因素方差分析。结果 HE染色和改良番红O-固绿染色结果表明:随着软骨内骨化的进展,髁突软骨细胞层长度减少,软骨下骨体积增加,下颌髁突体积增大;免疫组化结果表明:4组小鼠髁突软骨组织中均有FAM20C阳性表达,FAM20C主要表达于髁突软骨增殖软骨细胞层和前肥大软骨细胞层,少量表达于肥大软骨细胞层及软骨下骨层,随着髁突发育,FAM20C表达逐渐减少。统计学结果显示,各时间点FAM20C阳性表达差异有统计学意义(P<0.01)。结论 FAM20C参与小鼠下颌髁突发育,可能通过调节髁突软骨细胞的增殖和分化在髁突形成中发挥重要作用。     

牙髓细胞和肋软骨细胞共培养形成组织工程软骨的胶原类型分析

目的 :研究牙髓细胞和肋软骨细胞共培养形成的组织工程软骨的胶原类型。方法 :人肋软骨细胞和牙髓细胞按1∶1的比例用微团法共培养来促进其向软骨细胞分化。应用苦味酸天狼猩红染色,偏正光检测法研究形成的组织工程软骨胶原类型,并与颅颌面区域软骨进行比较。结果:肋软骨细胞和牙髓细胞微团法共培养形成的组织工程软骨中以I型胶原为主,同时包括II和III型胶原纤维,其纤维结构组成与肋软骨、髁突软骨增殖层及颞下颌关节盘的纤维结构相似。结论:肋软骨细胞和牙髓细胞共培养可形成的组织工程软骨,其组织结构与纤维软骨相似。     

Trauma modifies strength and composition of retrodiscal tissues of the goat temporomandibular joint

OBJECTIVES: Temporomandibular pain is often accompanied by pathologic changes to joint retrodiscal tissues. The substantial representation of females in this condition has encouraged hypotheses which link genetic or hormonally induced abnormalities in tissue composition (type III collagen, type I collagen, type III/type I ratio) to the development of temporomandibular disorders. As this condition is often associated with a history of orofacial trauma, we investigated the functional impact of retrodiscal trauma on the composition and biomechanics of retrodiscal tissues. DESIGN AND METHODS: Retrodiscal tissue of female goats received trauma or sham trauma. Following a healing period of 30 days, the tissues were pulled to failure on an extensometer. OUTCOME MEASURES: Assessments were made of tissue biomechanical properties (failure force, elastic stiffness, strain distribution). Tissue fragments were assayed for collagens I and III. RESULTS: Thirty days after surgical section of retrodiscal tissues, the tissue had reformed, but the composition and biomechanics were substantially changed. Healed tissue manifested less than half the strength of normal tissue (P = 0.02). In addition, the development of tissue strain shifted from a relatively even distribution to a confined region near the retrodiscal-discal attachment zone. It appeared that a large increase in the expression of type III collagen (179.6%; P = 0.038) and the ratio of type III/type I collagen (180.9%; P = 0.011) accounted for these functional changes. CONCLUSIONS: We suggest that shifts in collagen expression following injury create shifts in strain development which focus tissue stresses near the interface of the disc and retrodiscal tissue, and that this shift dramatically weakens the tissue and increases the probability of re-injury, inflammation and pain.     

Gender-specific differences in temporomandibular retrodiscal tissues of the goat

Healthy, adult, male and female goat temporomandibular retrodiscal tissues were characterized to determine if biochemical differences existed between the genders. RNA concentrations were not different between male and female retrodiscal tissues; however, the DNA concentration in female retrodiscal tissues was 82% greater than in male retrodiscal tissues. Collagen concentrations were significantly greater in male retrodiscal tissues, and this was reflected in significant gender differences of type I and III collagen concentrations. More specifically, male temporomandibular retrodiscal tissues contained 70% more type I collagen and 119% more type III collagen when compared to female retrodiscal tissues. These differences in collagens and DNA reflect a gender difference in temporomandibular retrodiscal tissue composition that underlies divergent biomechanical and neurophysiological properties.     

Immunohistochemical identification of type I and type III collagen and chondroitin sulphate in human pre-dentine: a correlative FEI-SEM/TEM study

AIM: To identify type I- (I-CF) and type III-collagen fibrils (III-CF) and chondroitin 4/6 sulphate (CS) within human pre-dentine by means of a correlative analysis under field emission in-lens-scanning electron microscopy (FEI-SEM) and transmission electron microscopy (TEM). METHODOLOGY: Human-extracted teeth were obtained and submitted to either a pre-embedding or a post-embedding immunolabelling procedure using monoclonal primary antibodies anti-I-CF, anti-III-CF and anti-CS. Gold-conjugated secondary antibodies were coupled to primary antibodies to visualize labelling under the electron beam. Correlative labelling patterns were obtained for I-CF and CS under both FEI-SEM and TEM. RESULTS: Field emission in lens-SEM analysis revealed an intricate three-dimensional network of I-CF and CS clarifying the intimate relationship between the two main components of the pre-dentine organic matrix. TEM analysis revealed odontoblasts exhibiting intracellular labelling for CS, which became more intense and diffuse over the pre-dentine organic matrix. The same diffuse immunoreaction was revealed for I-CF, whereas a weak immunolocalization of III-CF was found scattered throughout the pre-dentine layer and over the collagen fibrils. CONCLUSIONS: Both the pre- and post-embedding immunohistochemical approaches have led to the visualization of CF- and CS-labelling distribution within the pre-dentine layer, adding further knowledge on the elucidation of collagen-proteoglycans interaction in the organic matrix of human dental roots.     

Use of polyphenols as a strategy to prevent bond degradation in the dentin–resin interface

This study evaluated the effect of dentin pretreatment with the polyphenols quercetin and resveratrol on the resin‐dentin microtensile bonding strength (μTBS) and collagen fibrils stability of the adhesive interface. Different concentrations (100, 250, 500, or 1,000 μg ml^?1) of quercetin or resveratrol, or a mixture of quercetin and resveratrol (3:1, 1:1, 1:3; vol:vol), as well as distilled water or 2% chlorhexidine digluconate, were applied to etched dentin. Then, a two‐step etch‐and‐rinse adhesive was applied followed by composite restoration. Measurements of resin–dentin μTBS were made after 1 and 120 d. The stability of collagen fibrils in the hybrid layer was evaluated using transmission electron microscopy. The Student's t‐test and two‐way factorial anova with Tukey's test were used to analyze the effects of dentin pretreatment and storage time on μTBS values. Comparisons between μTBS measurements made on 1 and 120 d showed that resveratrol had the best performance, with significantly higher μTBS values after 120 d for all concentrations of resveratrol tested. Quercetin pretreatment resulted in a significant rise of μTBS when used at concentrations of 100 and 500 μg ml^?1. Quercetin + resveratrol at the ratio of 1:1 performed better than when used at ratios of either 3:1 or 1:3. Resveratrol might represent a potential approach to achieve desirable bonding stability and reduce the frequent replacement of composite restorations.     

Intrafibrillar mineralization of polyacrylic acid‐bound collagen fibrils using a two‐dimensional collagen model and Portland cement‐based resins

The biomimetic remineralization of apatite‐depleted dentin is a potential method for enhancing the durability of resin–dentin bonding. To advance this strategy from its initial proof‐of‐concept design, we sought to investigate the characteristics of polyacrylic acid (PAA) adsorption to desorption from type I collagen and to test the mineralization ability of PAA‐bound collagen. Portland cement and β‐tricalcium phosphate (β‐TCP) were homogenized with a hydrophilic resin blend to produce experimental resins. The collagen fibrils reconstituted on nickel (Ni) grids were mineralized using different methods: (i) group I consisted of collagen treated with Portland cement‐based resin in simulated body fluid (SBF); (ii) group II consisted of PAA‐bound collagen treated with Portland cement‐based resin in SBF; and (iii) group III consisted of PAA‐bound collagen treated with β‐TCP‐doped Portland cement‐based resin in deionized water. Intrafibrillar mineralization was evaluated using transmission electron microscopy. We found that a carbonyl‐associated peak at pH 3.0 increased as adsorption time increased, whereas a hydrogen bond‐associated peak increased as desorption time increased. The experimental resins maintained an alkaline pH and the continuous release of calcium ions. Apatite was detected within PAA‐bound collagen in groups II and III. Our results suggest that PAA‐bound type I collagen fibrils can be mineralized using Portland cement‐based resins.     

Ⅳ型胶原及Ⅳ型胶原酶与涎腺腺样囊性癌生物学特性的关系研究

用免疫组织化学ＡＢＣ法，观察２５例涎腺腺样囊性癌（ＡＣＣ）患者的癌组织中Ⅳ型胶原以及Ⅳ型胶原酶的表达与分布，探讨其与ＡＣＣ侵袭和转移的关系。结果显示，Ⅳ型胶原主要分布在基底膜上以及部分筛状假囊、腺管和肿瘤细胞浆内，Ⅳ型胶原酶分布在肿瘤细胞浆内及周围。经统计学检验，发现筛状－管状型ＡＣＣ，ＴＮＭ早期和无转移者，Ⅳ型胶原多阳性表达，Ⅳ型胶原酶多阴性表达；而实体型ＡＣＣ，ＴＮＭ晚期和转移者，Ⅳ型胶原多阴性表达，Ⅳ型胶原酶多阳性表达。本研究结果表明，Ⅳ型胶原低表达和Ⅳ型胶原酶的高表达可作为判定ＡＣＣ临床恶性程度的指征，是ＡＣＣ侵袭和转移的关键因素之一。     

氟对鼠颅骨成骨细胞基质蛋白表达的影响

目的研究低浓度氟环境对体外培养的胚胎鼠颅骨成骨细胞中的各类非胶原蛋白和胶原蛋白的表达。方法应用免疫细胞化学方法对成骨细胞中的骨涎蛋白，骨钙蛋白，骨桥蛋白，碱性磷酸酶和Ｉ型胶原表达进行检测。结果本研究可见胶原和非胶原蛋白在骨基质发育中的表达部位和作用有所不同；且在氟组的表达均要早于对照组。结论结果表明低浓度氟对较早期的成骨细胞具有一定的促增殖作用；同时氟可能还加速了成骨细胞的表型发育以及胶原和非胶原蛋白的合成，从而对骨基质的发育产生促进作用