凋亡相关蛋白在激素性幼兔股骨头缺血坏死动物模型中的表达及意义

目的 观察各凋亡相关蛋白在激素性幼兔股骨头缺血坏死动物模型股骨头组织中的表达情况,探讨该模型中调控凋亡的主要通路.方法 选用2月龄的新西兰大白兔,制作糖皮质激素性幼兔股骨头缺血坏死模型及对照组模型,根据是否发病将激素注射组分为未发病组和发病组.取股骨头软骨及软骨下骨组织用免疫组织化学法检测凋亡通路中凋亡相关蛋白天冬氨酸特异酶切的半胱氨酸蛋白酶-3(Caspase-3)、Caspase-8、人结合凋亡蛋白酶活化因子-1(apaf-1)、钙蛋白酶-1(calpain-1)的表达情况.分别测定在单位视野中Caspase-3、Caspase-8、apaf-1、calpain-1的积分光密度(IOD)值.结果 1.Caspase-3的IOD值分别为发病组25 142.72 ±21 528.48,未发病组2 069.63±1 096.96,对照组301.80±99.66.Caspase-8的IOD值分别为发病组24 942.63±18 942.99,未发病组2016.31±1 518.70,对照组236.85±97.94.Apaf-1的IOD值分别为发病组8 514.23±6 384.20,未发病组1 118.49±1 360.59,对照组95.13±38.05.Calpain-1的IOD值分别为发病组9 636.71 ±9 123.81,未发病组1 881.10±3 277.86,对照组126.71±47.35.Caspase-3在发病组和未发病组、对照组间差异有统计学意义(H=11.470、23.996,p＜0.01);Caspase-8在发病组和对照组间差异有统计学意义(H=22.178,P＜0.01);apaf-1在发病组和对照组间差异有统计学意义(H=22.808,P＜0.01);calpain-1在发病组和对照组间差异有统计学意义(H=13.553,P ＜0.01).2.线性回归分析:Caspase-8能够显著的预测Caspase-3,且回归方程回归效应显著,回归方程能够解释40.3％的变异,而apaf-1和calpain-1对Caspase-3的回归效应不显著.结论 凋亡受体通路可能在股骨头缺血坏死的凋亡过程中发挥主要调控作用.     

Reduction of silver complexes: towards an ever more elaborated insight in the influence of the type of ligand on the reaction rate

The present work deals with the investigation of the electrochemical reduction of silver thiosulphate (1,2-Ag(S₂O₃)₂^3?), thiocyanate (1,3-Ag(SCN)₃^2?) and 1,8-dihydroxy-3,6-dithiaoctane (1,2-Ag(DTO)₂⁺) complexes. The influence of the ligand type on the charge transfer rate is explained by the changing positions of the density distributions of electronic energy levels of the three complexes. The basics for this approach are the theories of energy band models (EBMs). An experimental methodology is developed to determine the energy density distributions. A Ti/TiO₂ substrate, obtained by galvanostatically anodising Ti, is put forward as an appropriate substrate for this investigation, and its semiconducting properties are determined. On this substrate, charge transfer (CT) controlled currents can be measured in a sufficiently large potential domain for the three systems. A method of pre-plating is optimised such that the overall semiconducting character of the substrate is kept during the monitoring of the (quasi-)stationary current/voltage diagrams. The active surface areas, necessary for the calculation of the current density/potential curves, are calculated. The positions of the energy density distributions, obtained by the derivation of the current density/voltage diagrams, of the three complexes, show that thiosulphate exhibits the smallest density of accepting energy levels in the given potential domain. For potentials above 0.5 V vs. SCE, the DTO complex has the largest density of vacant energy levels, but for lower potentials the situation is reversed.     

Investigation on the shaping ability of nickel-titanium files when used with a reciprocating motion

Introduction

The introduction of nickel-titanium (NiTi) files into clinical practice has improved the quality of canal shaping, but increasing the curvature of the root canal (or the diameter of the master instrument that prepares the full working length) could result in more transportation, straightening, and aberration of the canal. Nickel-titanium instruments are significantly safer and have an extended cyclic fatigue life when used with a reciprocating movement. The purpose of this study was to compare the shaping ability of FlexMaster NiTi instruments when used in either continuous or reciprocating movements.

Methods

Thirty-two Endo Training Blocks ISO 15, 2% taper, 10-mm radius of curvature, and 70° angle of curvature were prepared, according to the group, with FlexMaster NiTi instruments either in continuous rotation or in reciprocating (60° clockwise, 40° counterclockwise) movement. Preoperative and postoperative images of the simulated canals were taken under standardized conditions. The preoperative and postoperative images were combined exactly. The amount of resin removed was determined both for the inner (convex) and the outer (concave) sides of the curvature at 10 different points.

Results

In the most apical third of the canal, the Continuous group produced the largest enlargement of the canal as compared with the Reciprocating group (P < .05). In the apical third, the Continuous group displayed significantly greater enlargement of the canal at the external side.

Conclusions

The shaping of simulated canals is more centered by using a reciprocating motion when compared with continuous rotation, but the reciprocating motion could be more time-consuming.     

附着体应用于单侧上颌骨缺损修复的模型设计与制作

目的:探讨附着体应用于单侧上颌骨缺损修复的支架设计及制作方法。方法:在健侧余留牙舌面设计制作连续的舌面导板,MiNiSG附着体位于中切牙的近中,与舌面导板相结合。然后在此基础上设计制作赝复体基托,与腭部及舌面板紧密贴合。对制作完成的支架与基托做固位力测试。结果:获得了所设计的附着体支架及赝复体金属基托的实物模型,平均固位力达47N。结论:附着体应用于单侧上颌骨缺损修复在操作技术上切实可行,可增加整个修复体的固位与稳定。     

上颌第二磨牙三维有限元模型的CT扫描建模

目的:建立人上颌第二磨牙三维有限元模型。方法:将离体上颌第二磨牙经螺旋CT扫描,使实体结构的断面图像数字化处理后输入计算机,建立实体三维有限元模型。结果:在计算机上建立了上颌第二磨牙三维有限元生物力学分析模型,总节点为2 180 9个,4面单元数为14 44 9个。结论:所建模型结构完整,空间结构测量准确度高,单元划分精细,CT扫描建模技术的优点明显,所建立的模型使用性好。     

Morphogenesis and bone integration of the mouse mandibular third molar

The mouse third molar (M3) develops postnatally and is thus a unique model for studying the integration of a non-mineralized tooth with mineralized bone. This study assessed the morphogenesis of the mouse M3, related to the alveolar bone, comparing M3 development with that of the first molar (M1), the most common model in odontogenesis. The mandibular M3 was evaluated from initiation to eruption by morphology and by assessing patterns of proliferation, apoptosis, osteoclast distribution, and gene expression. Three-dimensional reconstruction and explant cultures were also used. Initiation of M3 occurred perinatally, as an extension of the second molar (M2) which grew into a region of soft mesenchymal tissue above the M2, still far away from the alveolar bone. The bone-free M3 bud gradually became encapsulated by bone at the cap stage at postnatal day 3. Osteoclasts were first visible at postnatal day 4 when the M3 came into close contact with the bone. The number of osteoclasts increased from postnatal day 8 to postnatal day 12 to form a space for the growing tooth. The M3 had erupted by postnatal day 26. The M3, although smaller than the M1, passed through the same developmental stages over a similar time span but showed differences in initiation and in the timing of bone encapsulation.     

Contribution of individual drugs to gingival overgrowth in adult and juvenile renal transplant patients treated with multiple therapy

Abstract. Drug regimens for transplantation often consist of multiple therapeutic agents and may result in drug-induced gingival overgrowth (DIGO). The aim of this study was to investigate the contribution of individual drugs in renal transplant patients. 147 adults (19–84 years) and 60 juveniles (3–18 years) were scored for DIGO and other clinical variables. Duration of treatment, dosage of drugs per kg body weight and serum cyclosporin levels were recorded. 44% of adults and 27% of children had DIGO. All patients were receiving prednisolone. More adults than children were administered cyclosporin, the reverse was true of azathioprine ( P 0.01), Explanatory models were evaluated by stepwise ordinal polynomial logistic regression. Statistically significant explanation ( P 0.05) of DIGO was afforded by prednisolone, nifedipine and azathioprine concentrations in adults and by cyclosporin, nifedipine and azathioprine concentrations in juveniles. Prednisolone and azathioprine were inversely related to the degree of DIGO. Plaque and irregularity scores, lip coverage and mouthbreathing status showed significant additional explanation in adults, replacing nifedipine and azathioprine in the final model. Irregularity was additionally explanatory in children, but no other clinical variables. A larger proportion of the variance of DIGO was explained by the available variables in children than in adults (pseudo r ²=0.50 versus 0.25). The degree of DIGO in renal transplant patients is influenced by the dosage of a number of individual components of multiple drug therapy independently of the presence of local clinical factors.