核转录因子Kappa B在犬乳恒牙替换过程中的表达

目的：观察犬乳恒牙替换过程中核转录因子Kappa B的表达，探讨其在牙齿替换中的作用。方法：用免疫组织化学方法检测NF—kB在犬乳恒牙替换过程中的表达。结果：NF—kB在幼犬替牙期的恒牙胚上方骨组织中的破骨细胞以及乳牙根面和牙髓腔内的破牙细胞中均有阳性信号表达。结论：NF—kB可能参与了犬乳恒牙替换过程中的牙齿的萌出过程。     

骨保护素配体在犬乳恒牙替换阶段的表达

目的：观察犬乳恒牙替换中骨保护素配体(osteoprotegerin ligand，OPGL)的表达，探讨其所起的作用。方法：免疫组织化学方法检测OPGL在犬乳恒牙替换期中的表达。结果：OPGL的阳性信号出现在乳牙根吸收面、牙囊周围和接近牙胚的牙槽骨陷窝中的破骨细胞，恒牙胚的成釉细胞、釉质、成牙本质细胞亦表达阳性。结论：OPGL可能参与了犬乳恒牙替换过程中恒牙胚的发育和牙齿的萌出过程。     

犬乳恒牙替换期间活化T细胞核因子NFATc1表达的研究

目的通过观察犬乳恒牙替换过程中活化T细胞核因子（nuclear factor of active T cells,NFAT）NFATc1的表达探讨其在此过程中的作用及意义。方法制备犬乳恒牙替换各阶段乳牙根、牙槽骨、恒牙胚的组织标本切片,用免疫组织化学方法检测NFATc1在犬乳恒牙替换期间的表达。结果NFATcl在破骨细胞、恒牙胚成釉细胞、成牙本质细胞层中表达阳性。结论NFATc1可能参与了犬乳恒牙替换生理过程中乳牙根、牙槽骨的吸收和恒牙胚的发育。     

犬乳恒牙替换期SHIP的表达

目的:研究犬乳恒牙替换过程中SHIP在组织中的表达情况,分析SHIP在犬乳恒牙替换过程中的作用.方法:应用免疫组织化学的方法检测SHIP在犬乳恒牙替换期组织中的表达.结果:SHIP在破骨细胞、破牙细胞和恒牙胚釉质层表达阳性.结论:SHIP在乳牙根吸收期表达阳性,在乳牙根稳定期和恒牙根期表达阴性,提示其在乳牙根吸收过程中发挥重要作用.     

TRAF6在犬乳恒牙替换阶段的表达

目的：观察犬乳恒牙替换过程中肿瘤坏死因子受体相关因子6（tumor necrosis factor-associated factor 6,TRAF6）的表达,探讨其在此过程中发挥的作用。方法：免疫组化方法检测TRAF6在犬乳恒牙替换期中的表达。结果：TRAF6在破骨细胞、破牙细胞及恒牙胚成釉细胞、成牙本质细胞层中表达阳性。结论：TRAF6可能参与了犬乳恒牙替换的生理过程中乳牙根吸收及恒牙胚的发育。     

RANKL在犬牙替换期牙龈上皮中的mRNA表达

目的：研究RANKL在犬乳恒牙替换期牙龈上皮中的mRNA表达及作用。方法：采用原位杂交法检测犬乳恒牙替换期牙龈上皮中RANKL的染色情况。实验组为处于前牙替换期的12周龄犬3只,对照组为恒前牙牙根发育完成的24周龄犬3只。比较两组间相应细胞的RANKL原位杂交染色光密度值,进行两样本t检验。结果：RANKL的mRNA阳性信号表达于犬牙替换期牙龈上皮中的棘层细胞和基底层细胞,实验组与对照组相比差别有统计学意义（p〈0.05）。结论：在牙齿替换过程中,RANKL可能参与牙龈上皮组织改建。     

IL-6在犬乳恒牙替换过程中的表达和意义

目的：研究犬乳恒牙替换过程中IL-6在组织中的表达情况，分析IL-6在乳恒牙替换过程中可能发挥的作用。方法：应用免疫组织化学及半定量分析的方法检测IL-6在成年犬和幼犬替牙期的表达。结果：成年犬IL-6的表达呈阴性；幼犬替牙期的乳牙成牙本质细胞层、牙周膜和恒牙胚上方骨组织中均有阳性信号表达。结论：提示IL-6可能在幼犬乳牙替换过程中发挥着一定的作用。     

C型利钠利尿肽在犬乳恒牙替换期的表达

目的:观察犬乳恒牙替换过程中C型利钠利尿肽(C-typenatriureticpeptide,CNP)是否有表达,并探讨其在此过程中所起的作用。方法:原位杂交方法检测CNP在犬乳恒牙替换期中的表达和染色。结果:CNP阳性信号出现在乳牙根吸收面的破牙细胞和接近牙胚的牙槽骨陷窝中的破骨细胞(以及恒牙胚的釉牙本质界)。结论:CNP被证实可能参与犬乳恒牙替换的生理过程,在乳牙根吸收和恒牙胚发育中起作用。     

骨保护素在犬乳恒牙替换期的表达

目的：观察犬乳恒牙替换中骨保护素（osteoprotegerin，OPG）在组织中的表达情况，探讨其在此过程中存在的作用。方法：分别对乳牙期、替牙期、恒牙期杂种犬取上、下颌骨，制备石蜡切片，进行HE染色和破骨细胞内OPG的免疫组化染色，用彩色病理图像分析系统分析各组染色强度灰度值（OD）。结果：OPG在乳牙根吸收面、恒牙胚牙囊周围和接近恒牙胚的牙槽骨陷窝中的破骨细胞、乳牙牙周膜细胞、成骨细胞、恒牙胚的成釉细胞、成牙本质细胞表达阳性。结论：OPG可能参与了犬乳恒牙替换过程中乳牙根吸收、恒牙胚的发育。     

核因子κB受体活化剂在犬乳恒牙替换阶段的表达

目的 观察犬乳恒牙替换中核因子κB受体活化剂(receptor activator of nuclear factor-κB，RANK)的表达，探讨其在此过程中所起的作用。直达免疫组织化学方法检测RANK在犬乳恒牙替换期中的表达和染色。结果 RANK的阳性信号出现在乳牙根吸收面的破牙细胞和接近牙胚的牙槽骨陷窝中的破骨细胞、恒牙胚的成牙本质细胞和前期牙本质中。结论 RANK可能参与了犬乳恒牙替换的生理过程，在乳牙根吸收和恒牙胚发育方面起作用。     

牙本质磷蛋白在犬乳恒牙替换期表达的原位杂交研究

目的：观察牙本质磷蛋白（DPP）mRNA在犬乳恒牙替换期的表达，寻找研究牙本质形成与损伤修复的良好模型。方法：采用原位杂交的方法，检测犬牙替换期恒牙胚、发育中的恒牙和乳牙DPP mRNA的表达。结果：犬恒牙胚、发育中的恒牙和乳牙均检测到DPP mRNA的表达，DPP mRNA存在强弱变化。结论：DPP在犬牙存在表达，并具有时空特异性。     

RANKL在人乳牙根生理性吸收过程中的表达

目的:探讨核因子κB受体活化剂配体RANKL在人乳牙根生理性吸收过程中的表达及作用。方法:运用免疫组织化学的方法检测人乳牙根生理性吸收过程中RANKL蛋白的表达。结果:乳牙的破牙细胞、牙髓成纤维细胞及成牙本质细胞胞浆中RANKL免疫组化染色阳性,且表达高于恒牙组,差异有统计学意义(P<0.05),乳牙牙周韧带成纤维细胞RANKL染色结果与恒牙组相比较差异无统计学意义(P>0.05)。结论:RANKL在人乳牙牙根生理性吸收过程中有表达,其可能对乳恒牙替换起到一定的促进作用。     

C型利钠利尿肽在人乳牙根生理性吸收过程中的表达

目的：探讨C型利钠利尿肽（C-type natriuretic peptide,CNP）在人乳牙根生理性吸收过程中的表达及作用。方法：运用免疫组织化学方法检测人乳牙根生理性吸收过程中CNP蛋白的表达。结果：乳牙的破牙细胞、牙髓成纤维细胞及成牙本质细胞胞浆中CNP免疫组化染色阳性,且表达高于恒牙组,差异有统计学意义（P〈0.05）,乳牙牙周韧带成纤维细胞CNP染色亦阳性。结论：CNP在人乳牙牙根生理性吸收过程中有表达,可能对乳恒牙替换起到一定的促进作用。     

犬乳恒牙替换期VEGF的表达及意义

目的：探讨犬乳恒牙替换过程中破骨细胞内血管内皮生长因子（Vascular endothelial grouth fautor,VEGF）的表达及意义。方法：分别对乳牙期、替牙期、恒牙期本地犬取上、下颌骨,制备石蜡切片,进行HE染色和破骨细胞内VEGF的免疫组化染色,用彩色病理图像分析系统分析各组染色强度灰度值。结果：替牙期犬牙根周围组织破骨细胞VEGF的免疫组化强度明显高于其它两组,且阳性信号出现在破牙细胞中。结论：VEGF在犬乳恒牙替换过程中可能起重要作用。     

Development of deciduous and permanent dentitions in the upper jaw of the house shrew (Suncus murinus)

The diphyodont tooth replacement in mammals is characterized by a single replacement of a deciduous dentition by a permanent dentition. Despite its significance in mammalian biology and paleontology, little is known about the developmental mechanisms regulating the diphyodont replacement. Because the mouse never replaces its teeth, this study used the house shrew, Suncus murinus, as a model to investigate the control of the diphyodont replacement of a deciduous dentition by successions and additions of permanent teeth. Using morphological and gene expression analyses of serial sections, we have demonstrated the development of the upper dentition of the house shrew. In this species, the deciduous tooth germs are formed but soon become vestigial, whereas the successional and accessional (molar) germs are subsequently formed and developed. There are distinct Shh expression domains in the deciduous, successional, and accessional tooth germs, and those of the latter two germs are identified from the appearance of their primary enamel knots. The developmental sequence of tooth germs in the house shrew indicates that two adjacent primary enamel knots of the successional and accessional germs do not develop simultaneously, but with a constant time lag. We suggest that this mode of tooth succession and accession can be explained by a sequential inhibitory cascade model in which the timing of initiation and the spacing of tooth development are determined by the inhibition from the primary enamel knots of developmentally preceding adjacent tooth germs.     

Observations on the aetiology of supernumerary upper incisors in the albino ferret (Mustela putorius)

An histological investigation was undertaken to study the development of deciduous and permanent supernumerary upper incisors in the albino ferret (Mustela putorius). Twenty-one specimens, aged between 35 and 47 days following fertilization, which exhibited supernumerary teeth were serially sectioned and the developing teeth graphically reconstructed.Twenty-seven deciduous supernumerary incisors, each occupying the second incisor tooth position, were studied; 17 of these were completely separate teeth, a further nine had separate pulp chambers but were contained within a single enamel organ common to that of the medially situated deciduous first incisor, while the remaining specimen showed evidence of a supernumerary tooth sharing a common pulp chamber with that of the first incisor.Thirteen permanent supernumerary upper incisors were observed and all were associated with the presence of the corresponding deciduous supernumerary. In six cases, the permanent supernumerary was present as a completely separate tooth while the remaining seven specimens showed varying degrees of fusion with the medially situated permanent first incisor tooth germ.The evidence suggests that the deciduous supernumerary incisor arose as a result of dichotomy of the medially situated deciduous first incisor tooth germ. It was further suggested that permanent supernumerary incisor teeth may be lost from the functional adult dentition as a result of fusion with the medially situated permanent first incisor during tooth development.