Runx 2在第三期牙本质形成过程中的分布及其意义

目的:研究Runx 2在牙髓炎症修复中的作用,探讨活髓保存的新途径.方法:建立大鼠第三期牙本质形成动物模型,用免疫组织化学染色方法研究Runx 2的表达变化及其意义.结果:Runx 2于牙髓损伤早期阶段表达于穿髓点下方细胞群;修复性牙本质形成初期于牙髓根尖部强表达,修复性牙本质形成中期表达减弱,而修复性牙本质形成末期表达为阴性.结论:Runx 2在牙髓损伤修复过程中的表达具有明显的时空特异性.     

牙本质非胶原蛋白与第三期牙本质的形成

牙本质是牙齿中主要的胞外矿化基质，其无机成分以含１２％水的羟基磷灰石为主（占重量的７０％）；有机成分主要由Ⅰ型胶原（约占基质８６％）、少量的Ⅲ型、Ⅴ型及Ⅰ型三聚体构成，另外还有１０％的非胶原蛋白。近年来，随着对牙本质非胶原蛋白研究的深入，其与第三期牙...     

第三期牙本质的生成和活髓保存治疗

1　概述牙本质的生成贯穿于牙齿的整个生物学生命过程。它是通过成牙本质细胞分泌基质、矿化完成的。牙本质一般可分为三类 :①第一期牙本质 (原发性牙本质 ) ,是由有丝分裂后的成牙本质细胞所分泌 ,构成牙本质的主体。②第二期牙本质 (生理性继发性牙本质 ) ,是在牙根发育完成后髓腔内侧壁四周缓慢形成的牙本质。③第三期牙本质 ,是外界对牙齿组织损伤性刺激时髓腔内侧相应部位形成的牙本质。第一、二期牙本质的生成涉及到绝大部分功能性的成牙本质细胞 ,只是由于成牙本质细胞的合成和分泌活性明显降低而使第二期牙本质形成速度减缓。第三…     

第三期牙本质基质形成的研究进展

第三期牙本质形成是牙髓-牙本质复合体因外界病理性刺激而产生的一种保护性反应。依据第三期牙本质基质的来源可进一步将其分为反应性牙本质和修复性牙本质。下面就第三期牙本质基质的形成过程作一综述。     

牙本质非胶原蛋白诱导兔修复性牙本质形成的实验研究——Ⅱ.修复牙本质形成的动物实验观察

将牙本质非胶原蛋白充填于兔切牙人工窝洞中,2周后修复性牙本质的形成明显快于对照组,提示牙本质非胶原蛋白有促进修复性牙本质形成的作用。     

E-Cadherin在修复性牙本质形成中的免疫组化研究

目的：观察细胞粘附分子Ｅ－ｃａｄｈｅｒｉｎ在修复性牙本质表成中的免疫反应和定位。方法：在大鼠上、下颌第一磨牙近中面制备单面洞,分别观察３、１５和３０ｄ。标本行常规组织学处理。利用鼠抗Ｅ－ｃａｄｈｅｒｉｎ为免疫组化ＳＡＢＣ法,对标本进行标记,ＨＥ复染。结果：Ｅ－ｃａｄｈｅｒｉｎ在术后３ｄ成牙本质细胞梁色较弱,牙髓细胞为阳性;１５ｄ后,成牙本质细胞样细胞和牙髓细胞染色阳性;３０ｄ后,成牙本质细胞样细胞     

颌骨骨折后血清无机盐及碱性磷酸酶的变化及意义

目的 研究颌骨骨折后血清无机盐和碱性磷酸酶（ALP）的变化和意义。方法 对40例例颌骨骨折患者和14例健康人进行血清钠、钾、氯、钙、磷、镁以及ALP含量的测定并作配对比较。结果 颌骨骨折组钠、钾、氯、钙含量与对照组无明显差异,磷、镁、ALP含量明显高于对照组（P＜0．05）。颌骨多线粉碎性骨折组的钙、磷、镁、ALP高于颌骨单、双线型骨折组,其中钙无明显差异,磷、镁、ALP有明显差异（P＜0．05）。单纯骨折组钙、磷、镁、ALP均低于骨折合并全身损伤组（P＞0．05）。骨折后即刻钙、磷、镁、ALP均高于骨折后4周,其中钙、磷无明显差异,镁、ALP有显著差异（P＜0．05）。结论 颌骨骨折后血清无机盐和ALP含量增高,它可能颌骨骨折的愈合与成骨过程中起着重要的调节作用。     

层粘连蛋白在修复性牙本质形成中的免疫定位

目的 研究层粘连蛋白（laminin,LN）在牙髓修复中的免疫定位和分布特征。方法 在大鼠第一磨牙制备单面洞,分别观察3d、15d和30d后修复性牙本质的形成情况。以免疫组化技术检测LN的免疫反应。结果 术后3d,修复性牙本质尚未形成。牙髓内成牙本质细胞呈阳性染色,前期牙本质为弱阳性。术后15d,可见修复性牙本质形成和成牙本质细胞样细胞的出现,成牙本质细胞样细胞和牙髓细胞免疫染色呈阳性。术后30d,已形成的修复性牙本质内LN染色阳性,免疫活性特别集中于修复性牙本质与牙髓交界处,成牙本质细胞样细胞染色呈强阳性。结论 LN的分布特征提示,在修复性牙本质形成过程中,LN可能是牙髓细胞附着的一个有利因素。     

纤维粘蛋白在牙本质形成中的作用

纤维粘连蛋白是一种多功能高分子量糖蛋白,广泛存在于胞牙基质中,在发育和损伤修复中调节细胞附着,移行和分化。近年来在牙齿发育和牙髓修复过程中,Ｆｎ在诱导成牙本质细胞及成本成本质细胞样细胞分化,促进本质形成过程中发挥重要的调控作用。本文就Ｆｎ在牙本质形成中的作用研究进展作了一综述。     

乳牙、年轻恒牙牙髓组织碱性磷酸酶的分布特征

采用组织化学和图象分析手段探讨了人乳牙，年轻恒牙牙髓组织中碱性磷酸酶的分布特征以及ＡＬＰ与牙髓修复再生能力的关系，基于ＡＬＰ的作用在乳牙，年轻恒牙中的含量差异，乳牙牙髓的自身修复潜力远不如年轻恒牙。     

内毒素脂多糖刺激大鼠牙髓的组织病理学反应

目的：研究牙髓在厌氧菌内毒素侵袭过程中的防御机制，建立内毒素性牙髓炎症模型。方法：采用大肠杆菌内毒素脂多糖（ＬＰＳ）涂布大鼠磨牙牙髓的方法，观察牙髓在ＬＰＳ刺激后的组织病理学反应。结果：浓度为５ｍｇ／ｍｌ的ＬＰＳ处理穿髓点处牙髓３０ｍｉｎ，牙髓早期表现为急性化脓性炎症组织像，１周后炎症扩散至大部分冠髓。至第５周，冠髓及大部分根髓坏死，而对照组牙髓内已无炎细胞浸润。结论：本组结果提示尽管牙髓组织有较强的自身防御、修复能力，但如不及时去除抗原物质，最终仍会导致牙髓坏死。     

修复性牙本质形成的大鼠模型

目的：建立修复性牙本质形成的动物实验模型,观察修复性牙本质形成的组织开矿学特征。方法：在Ｗｉｓｔａｒ大鼠第一磨牙近中面制备窝洞,分别观察３、１５、３０ｄ,标本切片,ＨＥ染色,显微镜下观察。结果：术后３ｄ未见修复性牙本质形成。１５ｄ后可见修复性牙本工可见骨样牙本质。窝洞下原代成牙本质细胞由新分化的成牙本质细胞样细胞取代。３０ｄ后,修复性牙本质明显增加。新分化的成牙本质细胞样细胞发生极化。结论：大鼠模     

大鼠牙本质基质蛋白1对人牙髓细胞增殖和ALP活性的影响

目的 :探讨大鼠牙本质基质蛋白 1(DMP1)对体外培养的人牙髓细胞增殖和ALP活性的影响。方法 :利用MTT法研究牙髓细胞的细胞增殖情况 ,碱性磷酸酶检测试剂盒检测牙髓细胞内ALP活性。结果 :DMP1在细胞培养 3d和 5d时 ,5 μg/mL组可促进人牙髓细胞增殖 (P <0 .0 5 )。细胞培养 3d时 ,仅5 μg/mL组可促进人牙髓细胞ALP活性 (P <0 .0 5 ) ;培养 5d时 1μg/mL和 5 μg/mL均可促进人牙髓细胞ALP活性 (P <0 .0 5 ) ;培养 7d时促进作用进一步加强 (P <0 .0 5 )。结论 :DMP1在一定浓度下可促进牙髓细胞的增殖 ;DMP1对牙髓细胞ALP活性的促进作用呈浓度依赖性 ,高浓度DMP1可以促进人牙髓细胞ALP活性 ,随着时间的延长 ,促进ALP活性的作用也增强。     

Ultrastructural localization of alkaline and acid phosphatase activities in dental plaque

Ultrastructural cytohistochemical techniques showed presence of acid and alkaline phosphatases in dental plaque. Both phosphatases had intra- and extramicrobial localization. In the extracellular matrix, phosphatases were associated with small vesicles of bacterial origin, or were freely scattered in the matrix without apparent connection with microbial structures. Intracellularly, alkaline (AlkP) and acid (AcP) phosphatases were observed in Gram-negative and Gram-positive bacteria, showing a different localization. The AlkP was mainly located in the periplasmic space, while AcP had a double preferential localization: along the outer surface of the cell wall and in the periplasmic space. Less frequently an intracellular phosphatase reaction was seen in the cytoplasm.     

DNA content and alkaline phosphatase expression in cells of different gingival overgrowths

The present study compared the alkaline phosphatase (ALPase) expression and DNA content at specific periods in cultured cells derived from non-inflamed enlarged gingivae of idiopathic gingivofibromatosis (IGF) and phenytoin-induced hyperplasia (PHG). Cultured cells from healthy gingiva or periodontal ligament (PDL) were used as controls. The DNA assay, ALPase assay and cytochemical staining for ALPase in cultured cells were performed at four, seven, and nine days. The presence of intense ALPase activity was a prominent feature in cultured IGF cells, whereas very low ALPase activity was detected in PHG cells. The cell lines tested showed no significant differences in DNA content. The expression of ALPase in these cells was population density-dependent. The observation that cells isolated from both types of gingival overgrowth exhibited a different ALPase profile at variance with normal gingival fibroblasts suggested that a distinct pathogenic mechanism may be involved in each type of gingival overgrowth.     

Temporal and local appearance of alkaline phosphatase activity in early stages of guided bone regeneration. A descriptive histochemical study in humans

Alkaline phosphatase (ALP) catalyzes the hydrolysis of phosphate esters and it seems to be a prerequisite for normal skeletal mineralization. Also, ALP is the most widely recognized marker of osteoblast phenotypes. By a tissue regenerative technique called Guided Bone Regeneration (GBR), it is possible nowadays to regenerate small bony defects. The aim of the present study was to investigate early events in bone healing and neogenesis by studying histochemically the temporal and local appearance of the marker Alkaline Phosphatase (ALP) in a GBR model system. Nine healthy volunteers (5 males, 4 females, mean age 31.7 years) participated in the experiment. After raising a mucoperiosteal flap from the mandibular second molar to the retromolar area in each volunteer, a hollow titanium test cylinder was placed into a congruent bony bed and the coronal end of the cylinder was closed with an ePTFE-membrane. Then the flap was adapted and sutured to obtain primary wound closure. After 2, 7 and 12 weeks, the regenerated tissue within the cylinders was harvested. Histologically, ALP activity was observed associated with the osteoid seams in the very basal part of the regenerate where new bone trabeculae were in the process of being formed. More coronally, large round cells seemed to secrete an ALP-positive substance since in the center of such cell clusters strong ALP activity located extracellularly was detected. In the present experiment, ALP seemed to have been an early sign of osteoblast secretion of a matrix which subsequently was determined to become osteoid. ALP activity was never seen isolated within connective tissue and away from bone. This is an indication that its source is linked to existing bone. The present study has documented for the first time the appearance of ALP activity in guided bone regenerations in humans. It has revealed that: 1) Osteogenesis in guided bone regeneration is preceded by localized, marked expression of ALP in an organized connective tissue environment. 2) Bone neogenesis is an early event in this experimental setup and may be detected already 2 weeks after wounding. 3) Expression of ALP and subsequent bone neogenesis is originating from and topographically linked to pre-existing bone structures.