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。     

下颌骨功能性偏斜对发育期大鼠髁突软骨胶原改建的影响

目的:观察下颌骨功能性偏斜对发育期大鼠髁突软骨内I型、II型以及III型胶原纤维分布及表达的影响。方法:取4周龄雄性SD大鼠40只,随机分为实验组(20只)和正常对照组(20只)。实验组佩戴自制的上切牙金属牙套引导下颌骨功能性右偏,对照组不佩戴任何装置,分别于实验1周、4周取得标本。HE染色及番红-O染色观察髁突软骨组织形态,苦味酸-天狼猩红偏振光染色以及免疫组化染色分别观察髁突软骨内I型、II型、III型胶原纤维含量以及分布表达情况,并进行相关半定量图像分析。结果:HE以及番红-O染色显示,实验1周后实验组牵张侧较正常组髁突软骨厚度显著增加,到4周后两组差异不显著;而实验组受压侧髁突软骨厚度4周后显著下降。天狼猩红染色及免疫组化染色结果显示,I型胶原主要表达在增殖层至成骨细胞层,II型胶原主要表达在软骨细胞层和肥大层。与正常组相比,1周及4周时实验组牵张侧软骨中区I型及II型胶原表达增强;受压侧软骨后区I型及II型胶原表达均显著减少。III型胶原主要表达在软骨纤维层至软骨细胞层,两组间无显著表达差异。结论:下颌骨功能性偏斜导致两侧髁突软骨发生了差异性生长改建,I型及II型胶原参与了改建中软骨内骨化过程。     

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。     

软骨细胞移植修复髁突软骨损伤的实验研究

目的 研究软骨细胞移植修复髁突软骨损伤后的效果及修复组织的性质。方法 选用成年雄性白免５３只,分成５组。第１组：细胞移植组;第２组：单纯胶原膜植入组;第３组：在实验动物有髁突前斜面形成直径２ｍｍ的全层损伤后,未植入任何物品;第４组：空白手术对照组;第５组：正常对照组。结果 细胞移植组动物的髁突软骨损伤区形成软骨组织修复。结论 异体兔髁突软骨细胞移植能够形成类似正常的关节软骨修复髁突软骨缺损。     

下颌前伸对成年大鼠髁突软骨Ⅹ型胶原表达的影响

目的:建立年轻成年大鼠下颌前伸动物模型,以X型胶原为检测指标,观察髁突软骨内成骨及其与下颌前伸持续时间的关系.方法: 9 周龄雌性大鼠75 只,分为3 组,其中2 组为实验组,另一组为对照组,实验组动物戴用统一规格自制的咬合前导矫治器,分别戴用12 h和24 h.3 组动物分别在实验后3、7、14、21、30 d处死后取双侧髁突组织,使用免疫组化和原位杂交方法从蛋白水平和基因水平检测髁突软骨组织切片中X型胶原的表达情况.结果:免疫组化结果显示, 24 h实验组X型胶原表达量在21 d时最高,且高于其他实验组;而12 h实验组峰值出现在30 d.原位杂交结果与免疫组化结果基本吻合.结论:功能矫治下颌前伸均能诱导年轻成年大鼠髁突软骨发生改建,但与12 h间歇性加力方式相比,24 h持续加力方式作用效果明显,且见效快.     

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。     

骨髓基质细胞诱导分化修复髁突软骨面缺失的实验研究

目的:采用骨髓基质细胞(BMSCs)体内修复髁突软骨全层缺失。方法:15只山羊,9只作为实验组,将BMSCs和少量软骨细胞(7:3比例混合)按5×107/mL与生物可降解材料复合后,植入山羊髁突软骨全层缺失处;对照组6只山羊,髁突软骨全层缺失区植入支架材料,分别于术后4、8、12周每个时间段取材3只实验动物,2只对照组动物;2组分别用HE染色、Ⅱ型胶原分泌的免疫组化法进行评价。结果:实验组术后4周,山羊髁突软骨缺失区能形成成熟的软骨组织,12周时软骨未退变。对照组不能形成成熟的软骨组织。结论:骨髓基质细胞在自体软骨细胞基质的诱导下,可以修复山羊颞下颌关节髁突软骨面全层缺失。     

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。     

雌激素受体与Ⅱ型胶原在人胚髁突软骨中的表达

目的探讨雌激素受体（ER）和Ⅱ型胶原在人胚髁突软骨中的表达情况。方法 采用苏木精-伊红（HE）及免疫组织化学染色法检测ERα、ERβ和Ⅱ型胶原在人胚颞下颌关节髁突软骨各层的表达。结果 Ⅱ型胶原主要表达于髁突软骨的过渡层及肥大层。ERα主要表达于髁突软骨的过渡层及肥大层,均匀分布于细胞内;ERβ集中表达于肥大层,且以细胞核内分布为主。纤维层及增殖层未见Ⅱ型胶原和ER表达,钙化软骨层有少量表达。结论 ER与Ⅱ型胶原在髁突软骨中分布一致,雌激素可选择性地结合不同亚型的ER,从而调节髁突软骨细胞分泌Ⅱ型胶原的能力。     

升高咬合对青春期大鼠髁突软骨BMP-2表达变化的影响

目的 观察升高咬合后髁状突软骨骨形成蛋白-2(BMP-2)的表达。方法 40只5周龄雄性SD大鼠,随机分为4组对照组和4组实验组(双侧后牙板升高咬合)。实验组与对照组动物分别在第7、14、21及28天时处死。取其右侧髁突,采用SABC免疫组化方法观察髁突软骨细胞BMP-2阳性细胞的分布及含量改变。结果 与对照组相比,实验组髁突软骨细胞BMP-2阳性细胞表达在实验第7、14天明显减少,第28天明显增多(P<0.05)。结论 咬合升高后引起髁突软骨BMP-2高表达,髁突软骨发生适应性改建。     

Expression of type X collagen and capillary endothelium in condylar cartilage during osteogenic transition--a comparison between adaptive remodelling and natural growth

Adaptive remodelling of the condylar cartilage in response to mandibular protrusion constitutes the rationale for bite-jumping appliances to solicit growth modification. By investigating the expression of type X collagen and capillary endothelium, this study was designed to evaluate the osteogenic transition of chondrogenesis during adaptive remodelling of condylar cartilage and compare it with that under natural condylar growth. One hundred female Sprague-Dawley rats, 35 days of age, were divided into five experimental groups (n = 15, fitted with bite-jumping appliances) where condylar adaptation was created by forward repositioning of the mandible, and five control groups (n = 5) where the condyles underwent natural growth. The animals were sacrificed at 3, 7, 14, 21 and 30 days and 7 mum serial sections of the condyles were processed for in situ hybridization and immunohistochemical analyses. The expression of type X collagen in the hypertrophic zone and capillary endothelium in the erosive zone of condylar cartilage were examined to evaluate osteogenic transition, a critical programme leading to endochondral ossification. The results showed that (1) The temporal pattern of the expression of type X collagen and capillary endothelium during condylar adaptation coincided with that during natural condylar growth. (2) The amount of the expression of these two factors during condylar adaptation was significantly higher than that during natural growth (P < 0.001). It is suggested that condylar adaptation in growing rats triggered by mandibular forward positioning enhances osteogenic transition which eventually results in increased bone formation.     

Forward deviation of the mandibular condyle enhances endochondral ossification of condylar cartilage indicated by increased expression of type X collagen

OBJECTIVE: Using type X collagen as a marker, this research was designed to examine the alteration of condylar growth in response to mandibular condylar forward positioning. METHODS: One hundred female Sprague-Dawley rats with 5 weeks of age were randomly divided into five experimental and five control groups. In the experimental groups, bite jumping appliances created forward positioning of the condyle. The experimental rats, together with the age-matched controls, were sacrificed on days 3, 7, 14, 21 and 30, respectively. Tissue sections were cut in the sagittal plane through the mandibular condyle and were processed for in situ hybridization and immunostaining of type X collagen and then for quantitative imaging analyses. RESULTS: (1) Both type X collagen mRNA in situ hybridization signals and type X collagen immunostaining were localized within the hypertrophic zone of the condylar cartilage. (2) With condylar forward positioning, the level of type X collagen mRNA signals (8,541 +/- 74 microm(2) at peak) was 300% higher than that in the controls (2,117 +/- 78 microm(2) at peak); type X collagen immunostaining in condylar advancing groups (54,864 +/- 134 microm(2) at peak) was 254% more than that in the controls (15,470 +/- 121 microm(2) at peak). (3) The amount of type X collagen mRNA signals and immunostaining in experimental and control groups reached the highest levels at day 14 and day 21, respectively, indicating that an increase in endochondral ossification occurred 21 days after condylar forward deviation. CONCLUSION: Condylar forward repositioning provokes an enhanced maturation of condylar chondrocytes resulting in increased synthesis of type X collagen, a extracellular protein that attributes to endochondral ossification.     

大鼠下颌功能前伸后激活髁突胰岛素样生长因子1基因表达

目的研究用功能矫治器前伸生长期大鼠下颌后，髁突软骨中胰岛素样生长因子（ＩＧＦ１）基因表达的变化规律，探讨功能矫形治疗的分子机理。方法将６０只雄性５周龄ＳＤ大鼠分为对照组和实验组，按１天、３天、１周、２周、３周和４周６个阶段，应用原位杂交技术研究髁突软骨中ＩＧＦ１ｍＲＮＡ的表达变化。结果正常生长期大鼠下颌髁突软骨有ＩＧＦ１ｍＲＮＡ表达；前伸大鼠下颌使髁突软骨细胞中ＩＧＦ１ｍＲＮＡ阳性强度和阳性细胞数目均增加。这一变化具有时间性，即实验３天后开始升高，实验后１周～２周达最高值，３周～４周时逐渐降低。结论功能前伸下颌后ＩＧＦ１ｍＲＮＡ转录升高，表明功能矫形后髁突软骨的生长改建可能是由于咀嚼肌牵张激活了ＩＧＦ１的基因表达。     

下颌前伸后大鼠髁突软骨增殖细胞核抗原表达昼夜节律

目的 比较昼夜不同时段戴用功能矫治器后,髁突软骨增殖细胞核抗原（ＰＣＮＡ）表达的昼夜变化,为探讨功能矫治昼夜最佳介入时段,提供直接实验依据。方法 采用免疫组织化学法,检测不同时段前伸大鼠下颌后,髁突软内ＰＣＮＡ表在的昼液变化。结果 戴用功能矫治器后,ＰＣＮＡ表达强度增加;白天戴用组明显高于夜晚组。结论 功能矫治器可以刺激髁突软骨增生;在髁突软骨昼夜自发性生长最旺盛时段戴用矫治器,效果最佳。     

导下颌向前对生长期大鼠髁突软骨结缔组织生长因子表达的影响

目的:通过建立导下颌向前的Sprague-Dawley (SD)大鼠的动物模型进行免疫组化实验,观察结缔组织生长因子(CTGF)在髁突软骨中分布的变化,探讨CTGF对前伸下颌后的髁突软骨的影响。方法:建立SD大鼠动物模型,选取45只5周龄SD 雌性大鼠,体重约100 g,随机分为对照组(20只)和实验组(25)只,组内再随机平均分为5组(3、7、14、21 和30 d)。实验组动物24 h佩戴改良可摘式上颌斜面导板矫治器,对照组动物不做处理。免疫组化染色标记CTGF,观察髁突软骨各层CTGF的表达变化。对CTGF的阳性表达量进行半定量分析。结果:对照组和实验组中髁突软骨组织中均有CTGF的表达,主要分布于肥大层和增殖层。实验组不同时间点髁突肥大层和增殖层中CTGF的平均光密度值分别高于对照组的平均光密度值(P<0.05 ) 。与对照组相比,实验组7 d后髁突肥大层和增殖层中CTGF的表达开始上升,到第14天达到最高,之后CTGF表达回落,但仍高于对照组(P<0.05 )。实验3 d、30 d,肥大层和增殖层中CTGF实验组与对照组相比无统计学差异。结论:CTGF可能参与了功能负荷改变所导致的髁突软骨适应性改建活动。     

Ⅰ、Ⅱ、Ⅹ型胶原及碱性磷酸酶在鼠胚髁突软骨发生中的意义

目的　探讨髁突软骨发生中Ⅰ、Ⅱ、Ⅹ型胶原及碱性磷酸酶(ALP)的组织学分布特征及髁突软骨内成骨的 分子机制。方法　取14~18 d鼠胚,分别行Ⅰ、Ⅱ、Ⅹ型胶原及ALP抗体免疫组织化学染色。结果　胚胎第14天, 髁突形成的位置可见间充质细胞聚集并与骨膜相连,间充质细胞及骨膜中Ⅰ型胶原及ALP阳性;第15天,肥大软 骨细胞中Ⅹ型胶原表达阳性,其周围的间充质细胞中Ⅰ、Ⅱ型胶原阳性,ALP在两种细胞中均呈阳性;第16天,软骨 膜、纤维层间充质细胞至肥大软骨细胞上层中Ⅰ型胶原表达阳性,多形细胞层下方至肥大软骨细胞下层中Ⅱ型胶 原表达阳性,Ⅹ型胶原仅表达于肥大软骨细胞,ALP在软骨膜及肥大软骨细胞中呈阳性,但在多形细胞层呈阴性或 弱阳性。结论　髁突软骨的发生机制与长骨不同,其软骨内成骨的早期Ⅰ、Ⅱ、Ⅹ型胶原均有表达,可能始发于ALP 阳性的下颌骨膜间充质细胞。     

前伸下颌后大鼠髁突内源性胰岛素含量昼夜节律变化的研究

目的：研究前伸大鼠下颌后,大鼠髁突内源性胰岛素（Ｉｎｓ）含量昼夜节律变化,探讨功能矫治器在一天中的最佳戴用时段,方法：采用放射免疫学技术,测定生长期大鼠在自然状态及不同时间段（白天或夜晚）戴用同一功能矫治器前伸下颌时,大鼠髁突内源性Ｉｎｓ含量在１昼夜内每４ｈ的变化。结果：自然状态下,生长期大鼠髁突内源性Ｉｎｓ含量存在昼夜节律,峰值相位约在１２：１３,功能矫治器前伸下颌后,此节律性并未消失;白天戴用     

Bone morphogenetic protein 3 expression pattern in rat condylar cartilage, femoral cartilage and mandibular fracture callus

Mandibular condylar cartilage differs from primary cartilage in morphological organization of the chondrocytes and in responses to biomechanical stress and humoral factors. For the first time, we describe the expression of Bmp3 mRNA in relation to types I, II and X collagen mRNA (as determined by in situ hybridization) in chondrocytes of the rat mandibular condylar cartilage, femoral articular cartilage, femoral growth plate cartilage, and temporal cartilage, which transiently appeared in the reparative response stage of mandibular ramus fracture healing. In all cartilages evaluated, Bmp3 was expressed in proliferating chondrocytes that expressed type I collagen in condylar cartilage, articular cartilage, and temporal cartilage appearing during fracture healing. Bmp3 was also found in hypertrophic chondrocytes that expressed type X collagen mRNA in all cartilages evaluated. Furthermore, in remodeling bone, Bmp3 mRNA was strongly expressed in active osteoblast cells in periosteal reaction layers formed after fracture. These findings suggest that Bmp3 expression in a special layer of typical articular cartilage may be regulated by mechanical stress stimulation. We also found that Bmp3 was expressed in the periosteal layers of the bone segments near the fracture site during fracture healing.