Lactate dehydrogenase isoenzymes in human radicular cysts

Lactate dehydrogenase (LDH) isoenzymes of 15 clinically dormant radicular cysts were examined. A fragment from each cyst was homogenized, centrifuged and the LDH isoenzymes in the supernatant were separated by cellulose acetate paper electrophoresis. The strongest bands of the cysts were LDH-5 and LDH-4.     

Lactate dehydrogenase isoenzymes in squamous cell carcinomas of the oral cavity

Lactate dehydrogenase (LDH; EC 1.1.1.27) isoenzymes in human epithelial cells from squamous cell carcinomas and healthy tissues of the oral cavity of five patients were analyzed using isoelectric focussing. A new basic isoenzyme and high LDH-7 and LDH-9 activity were found in tumor cells in contrast to epithelial cells of adjoining nontumor tissue. These findings indicate that gradual changes in the percentage distribution of LDH isoenzymes may represent a useful parameter of disease activity in patients with squamous cell carcinomas.     

牙周膜相关蛋白1在人牙周膜细胞成骨分化过程中的表达

目的 研究牙周膜相关蛋白1（PLAP-1）在人牙周膜细胞（PDLC）成骨分化过程中的表达变化,为明确PLAP-1 在牙周组织中的作用奠定基础.方法 酶消化法培养人PDLC,免疫细胞化学染色鉴定其来源和PLAP-1 的表达,茜素红染色和碱性磷酸酶（ALP）实验鉴定其成骨分化能力,定量反转录聚合酶链反应（RT-PCR）检测其成骨分化过程中,PLAP-1、Periostin、RGD-CAP、RUNX2、OCN 和OPN mRNA 表达变化,Western blot 检测PLAP-1、RUNX2 和OCN 蛋白表达变化并进行统计分析.结果 培养的人PDLC 来源于间充质;人PDLC 矿化诱导21 d 后茜素红染色阳性,矿化诱导后7、14、21 d 时ALP 活性较对照组明显增高（P ＜ 0.05）,具有成骨分化能力;PLAP-1 免疫细胞化学染色阳性;定量RT-PCR 和Western blot 结果显示,人PDLC 在mRNA 和蛋白水平均表达PLAP-1,且mRNA 表达量随人PDLC 成骨分化过程发生变化,诱导14 d上调,诱导21 d 下调,较对照组有明显差异（P ＜ 0.05）,Western blot 检测蛋白表达显示类似的表达趋势.结论 PLAP-1 在基因及蛋白水平均高表达于人PDLC,其表达量随人PDLC 成骨分化成一定模式,提示其参与调控牙周膜的功能与稳定,但其精细的调控功能还有待进一步深入研究.     

Lactate dehydrogenase isoenzymes in dental pulp of rats according to stage of root development

The objective of this study was to present a classification of the root development stage of female rat molar teeth and to evaluate the variation in the lactate dehydrogenase (LDH) activity and electrophoretic isoenzyme profile according to the stage of root development of the molar teeth. We also studied the LDH activity and isoenzymes of the pulp of incisor teeth. The stage of development of the rat first molar at the age of 15 days and that of the second molar at the age of 18 days was classified as the beginning of root formation. At the age of 15 days, the electrophoretic profile of the isoenzymes for the first molar showed a prevalence of LDH-1 followed by LDH-2. However, for the maxillary second molar there was a prevalence of LDH-4 followed by LDH-1, while for the mandibular second molar LDH-1 predominated followed by LDH-2 and LDH-4. From 18 days of age, the prevalence was always of LDH-1. The electrophoretic profile of LDH isoenzymes from the pulp of the incisor teeth at the ages studied (25 and 60 days) showed the following order of prevalence: LDH-1 > LDH-2 > LDH-3 > LDH-4 > LDH-5. These results suggest that there are variations in the prevalence of the various forms of LDH isoenzymes in the dental pulp of rats according to the developmental stage of the root.     

人牙周膜成纤维细胞原代培养的研究

目的：研究如何提高人中膜成纤维细胞原代培养的成功率。方法：以牙槽窝刮取组织块法替代传统的牙根刮取法，以组织块自然贴壁法替代传统的干燥贴壁法。结果：48h后细胞游出率为40％，而成功传代率为20％，结论：通过对取材和培养方法的改良，可以显著提高人牙周膜成纤维细胞原代培养的成功率。     

Proliferative activity in the juxtaradicular human periodontal ligament

Abstract— The aim of the present study was to evaluate cell proliferation, assessed by MIB 1, with respect to the type and the distribution of proliferating cells in the healthy juxtaradicular periodontal ligament (PDL) from completely formed human teeth. Immunohistochemical markers against vimentin, CD68 and S-100 were used to characterize cell type. The applicability of the immunohistochemical method on explants of human PDL was also evaluated. The results indicated that under physiological conditions, the majority of the proliferating cells in the PDL were mesenchymal cells predominantly located paravascularly in the middle third of the PDL. Furthermore, MIB 1 reacting with the Ki-67 antigen together with the avidin-biotin-complex technique was proved to be an efficient marker of cell proliferation in explants of human PDL.     

Proliferative activity in the juxtaradicular human periodontal ligament

The aim of the present study was to evaluate cell proliferation, assessed by MIB 1, with respect to the type and the distribution of proliferating cells in the healthy juxtaradicular periodontal ligament (PDL) from completely formed human teeth. Immunohistochemical markers against vimentin, CD68 and S-100 were used to characterize cell type. The applicability of the immunohistochemical method on explants of human PDL was also evaluated. The results indicated that under physiological conditions, the majority of the proliferating cells in the PDL were mesenchymal cells predominantly located paravascularly in the middle third of the PDL. Furthermore, MIB 1 reacting with the Ki-67 antigen together with the avidin-biotin-complex technique was proved to be an efficient marker of cell proliferation in explants of human PDL.     

In vitro strength of the human periodontal ligament.

The tensile properties of the human periodontal ligament were studied by direct loading and compression experiments. It was found that the ligament behaved in an elastic manner up to an elastic limit after which rupture occurred. The values obtained for the tensile strength of the ligament are in general agreement with those of other workers for similar tissues.     

人牙周韧带生物力学的体外研究

作者在研究人牙周韧带的形态结构特点的基础上，应用生物软组织微机图像视频测量系统测试了其拉压力学性质．探讨了牙周韧带形态结构与力学性质的关系，分析了牙周韧带力学性质的非线性和应力应变关系的区域特性及其临床意义。     

人牙周膜干细胞的分离培养及初步鉴定

目的 体处分离培养人类牙周膜干细胞并对其生物学性状进行初步鉴定.方法 采用有限稀释法进行牙周膜干细胞克隆筛选,获得单细胞克隆来源细胞,检测其克隆形成率,并采用免疫组织化学染色、碱性磷酸酶染色、免疫荧光染色等方法鉴定牙周膜干细胞的组织来源及生物学特性.结果 有限稀释法获得的牙周膜干细胞克隆株呈簇状生长,排列紧密,细胞呈圆形或椭圆形,细胞较小,排列形成紧密的团块状.免疫组化染色显示细胞波形蛋白阳性,角蛋白阴性;碱性磷酸酶染色阳性;早期间充质干细胞的标志物STRO-1荧光染色显示细胞发出明亮的红色荧光,表达阳性.结论 牙周膜中存在具有高增殖能力的干细胞,克隆化分离培养的人牙周膜干细胞具有强克隆形成能力,具有间充质干细胞表型和生物学特性.