冠心病患者白细胞变形能力和粘附功能及细胞粘附分子表达的变化

为探讨白细胞变形能力、粘附功能和细胞粘附分子与冠心病的关系，检测了188例冠心病患者和68例健康人外周血白细胞滤过指数、粘附率、白细胞CD18表达和血清可溶性细胞间粘附分子-1浓度变化。结果发现，冠心病病人白细胞滤过指数、粘附率、白细胞CD18表达及可溶性细胞间粘附分子-1浓度均明显增高，与对照组比较差异有极显著性意义（P＜0．001）。急性心肌梗塞病人各指标增高较不稳定心绞痛和陈旧性心肌梗塞更明显（P＜0．001）、冠心病病人白细胞滤过指数、粘附率与白细胞CD18表达和可溶性细胞间粘附分子-1浓渡呈正相关（r=0．679～0．764，P＜0．001），白细胞滤过指数与粘附率呈正相关（r=0.663，P＜0．001）。提示白细胞变形能力降低，粘附功能和CD18表达及可溶性细胞间粘附分子-1浓度增高，参与了冠心病的发生，且与病情变化有关。     

Lack of correlation between tubular dentine cement penetration, adhesiveness and leakage in roots filled with gutta percha and an endodontic cement based on epoxy amine resin

Objective

To analyze possible correlations among tubular dentine cement penetration, adhesiveness and apical leakage in fillings performed with gutta percha and an endodontic cement based on epoxy amine resin.

Material and Methods

Sixty similar, extracted human mandibular central incisors were irrigated, instrumented and filled following the same protocol. First, apical leakage was quantified by fluid filtration tests. Then, these same specimens were sectioned for analysis of tubular dentine cement penetration and the middle thirds were submitted to push-out tests to analyze the adhesiveness of the fillings.

Results

In brief, the means and standard deviations with a confidence interval of 95% were as follows: tubular dentine cement penetration (8.875±4.540), adhesiveness (4.441±2.683) and apical leakage (0.318±0.215). The data were confronted using the Pearson''s test (P>0.05), and it was possible to prove that there was no correlation between (1) tubular dentine cement penetration and apical leakage (r²: 0.08276), (2) tubular dentine cement penetration and adhesiveness (r²: -0.2412) and (3) adhesiveness and apical leakage (r²: 0.1340).

Conclusion

After analysis of these data, it could be observed that there exists no correlation among the variables analyzed in this study.     

不同表面处理的纯钛对血小板黏附特性的影响

目的:观察钛-血小板相互作用时不同表面处理的纯钛对血小板黏附特性的影响。方法:将商业纯钛片制备成4种不同表面形貌的样本,即抛光表面、酸蚀表面、大颗粒喷砂加酸蚀表面、碱热处理表面,样本经扫描电镜观察及静态接触角分析后,在其表面滴加新鲜制备的富血小板血浆,30 min后进行扫描电镜观察。结果:大颗粒喷砂加酸蚀表面黏附的血小板最多,且形变明显;酸蚀表面血小板的黏附量也较多,但形变较少,以球形居多;抛光表面和碱热处理表面黏附的血小板很少,局部甚至缺无。结论:纯钛表面复杂的微形貌有利于血小板的黏附,钛表面的润湿性对血小板的黏附特性也有影响,亲水性表面不利于血小板的黏附。     

Temporal effects of cell adhesion on mechanical characteristics of the single chondrocyte.

Cell adhesion to material surfaces is a fundamental phenomenon in tissue response to implanted devices, and an important consideration in tissue engineering. For example, elucidation of phenomena associated with adhesion of chondrocytes to biomaterials is critical in addressing the difficult problem of articular cartilage regeneration. The first objective of this study was to measure the mechanical adhesiveness characteristics of individual rabbit articular chondrocytes as a function of seeding time to provide further understanding of the cell adhesion process. The second objective was to quantify the force required to separate the plasma membrane from the underlying cytoskeleton as a function of seeding time. After culturing chondrocytes on glass coverslips for 1, 2, 4, 6 h, two biomechanical tests were performed on single chondrocytes: (i) mechanical adhesiveness measurement by the cytodetacher; and (ii) plasma membrane tether formation force measurement by optical tweezers. Cell mechanical adhesiveness increased from 231+/-149 Pa at 1 h to 1085+/-211 Pa at 6 h. The cell contact area with the substrata increased from 161+/-52 microm(2) at 1 h to 369+/-105 microm(2) at 6 h. The tether formation force increased from 232+/-23 pN at 1 h to 591+/-17 pN at 6 h. Moreover, fluorescence staining by rhodamine-phalloidin demonstrated the process of actin spreading within the cytoskeleton from 0.5 to 6 h and allowed for measurement of cell height which was found to decrease from 12.3+/-2.9 microm at 0.5 h to 6.2+/-0.9 microm at 6 h.     

6 Gy γ射线对骨髓细胞生物力学特性的影响

目的了解放射损伤条件下骨髓细胞(包括基质细胞和造血细胞)生物力学特性的改变。方法以6Gy^60Coγ射线照射昆明系小鼠制备动物模型，以细胞电泳法检测骨髓细胞的细胞电泳率，荧光探针法测定细胞膜微黏度，旋转法检测细胞的黏附性，核孔滤膜法检测细胞的变形指数。结果放射损伤后骨髓细胞的变形能力降低，细胞膜微黏度增加，细胞的黏附率和电泳率显著降低。结论6Gy^60Coγ射线对骨髓细胞的生物力学特性有显著影响，可能是放射损伤后造血功能减退的原因之一。     

In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride

We investigated the influence of sodium fluoride on polymorphonuclear leukocyte (PMN) adhesiveness in a healthy subject with low serum levels of fluoride. The PMN were separated from venous blood, and the percentages of adhered and unadhered cells were determined in vitro in plastic culture plates. The cells were cultured with five different fluoride concentrations ranging from 6.25 10(-2) microM to 4.0 microM in the presence and absence of autologous serum. PMN adhesiveness in both the presence and in the absence of autologous serum was 98.5%; the addition of fluoride had no effect on the results in the absence of serum. However, in the presence of autologous serum, PMN adhesiveness decreased significantly with the addition of fluoride (P < 0.05) from 0.5 microM. The decrease was smaller (1.1%) at a concentration of 0.125 microM, and larger at 12 times this concentration of fluoride (52.7%). We conclude that sodium fluoride reduces PMN adhesiveness in a dose-dependent manner. The effect is not direct, but should be modulated by a seric factor.     

Influence of Different Surface Pretreatments of Zirconium Dioxide Reinforced Lithium Disilicate Ceramics on the Shear Bond Strength of Self-Adhesive Resin Cement

AimTo analyze the influence of different surface pretreatments of zirconium dioxide reinforced lithium disilicate ceramics on the shear bond strength of self-adhesive resin cement.Materials and methodsEighty-four zirconium reinforced lithium disilicate disc Vita suprinity (Vita Zahnfabrick, Bad Säckingen, Germany) 14x12x2 mm specimens were fabricated according to the manufacturer''s recommendations. The specimens were embedded in acrylic resin blocks and randomly divided in seven groups (n=12/each) accorrding to the treatment: Group 1- 10% hydrofluoric acid; Group 2- silane; Group 3- hydrofluoric and silane; Group 4- sandblasting with silane; Group 5- Er: YAG laser+ silane; Group 6- Nd: YAG laser + silane; and the control group, in which the specimens were not treated. Round shape composite discs (Filtek Bulk fill, 3M ESPE, St.Paul, Minnesota, USA) with 3.5 mm diameter, were made for shear bond strength testing, and then cemented to the ceramic sample surface using composite cement (RelyX U200 Automix, 3M ESPE, Neuss, Germany). After cementing the composite disc on the sample, the samples were subjected to shear bond strength test of 10 N with a “stress rate” of 1 MPa / s. To determine the nature of the fracture (adhesive, cohesive or adhesive-cohesive), the broken samples were examined under a stereomicroscope. The ANOVA test and the Tukey test were used to compare the values ​​of the bond strength characteristics between different types of materials. All tests were performed with a significance level of α = 0.05.ResultsThere was a significant difference in the shear bond strength of self-adhesive cement to dental lithium-disilicate ceramics reinforced with zirconium dioxide after different preparation protocols (p<0, 05). The treatment of lithium disilicate ceramics reinforced with zirconium dioxide by silanization, sandblasting + silanization, Nd: YAG + silanization resulted in significantly higher bond strength compared to the control group. There was statistically higher bond strength of self-adhesive cement after pretreatment of lithium disilicate ceramics Nd: YAG + silanization compared to Er: YAG + silanization (p <0.05). Adhesive fracture dominated in the control group, sandblasting + silanization group, and in the laser groups, while mixed fracture dominated in other groups.ConclusionUnder the limitations of this study, the Nd:YAG irradiation with silanization could be used as pretreatment for providing greater shear bond strength of self-adhesive resin cement to zirconium reinforced lithium disilicate.     

高血脂血瘀模型白细胞粘附活化和白细胞介素2、6和8的变化

建立高脂、免疫损伤、应激等综合因素所致高血脂血瘀动物模型，探讨动脉粥样硬化相关免疫损伤和炎症反应机制。将40只Wistar大鼠随机分成高脂组、免疫损伤高脂组（异体血清蛋白和高脂)、免疫损伤应激高脂组(高脂、异体血清蛋白和肾上腺素)和应激组(单纯肾上腺素)。观察不同模型脂质代谢、白细胞粘附活化及白细胞介质的变化。结果发现，和应激组比较，高脂组、免疫损伤高脂组和免疫损伤应激高脂组总胆固醇、低密度脂蛋白胆固醇水平明显升高，免疫损伤高脂组和免疫损伤应激高脂组脂蛋白(a)水平明显升高，尤其是免疫损伤应激高脂组甘油三酯水平升高更显著(P＜0．05和P＜0.01)，高脂组、免疫损伤高脂组和免疫损伤应激高脂组白细胞介素6水平明显升高，高脂组和免疫损伤高脂组白细胞介素8水平明显升高(P＜0.01)；应激组白细胞粘附分子CDll／CDl8表达率明显高于其他三组(P＜0．05)；各组间白细胞介素2水平无显著差异。结果提示，高脂、免疫损伤、应激等综合因素所致高血脂血瘀模型，为中医药多环节干预动脉粥样硬化和血瘀证的作用研究提供了一个较为可靠的模型，同时初步阐明了免疫损伤、炎症反应机制在动脉粥祥硬化发病机理中的重要作用，以及和高血脂协同致病的机理。     

在流动血液中蜂胶对血小板活性的抑制作用

目的： 探讨蜂胶提取液对流动状态下血小板活性的影响。方法: 采用体外灌注法，用纤维蛋白原和人Ⅲ型胶原蛋白包被盖玻片，复制血管内膜创伤模型，正常血液流经纤维蛋白原和胶原膜表面后，在切应力为 1 000/s 时，测量血小板粘附率。浓度为0.1 g/L的24%乙醇蜂胶提取液作实验组，加入24%的乙醇作阴性对照组，同浓度的阿魏酸乙醇溶液作阳性对照组。结果: 分别以纤维蛋白原和胶原蛋白膜模拟创伤表面，两实验组血小板粘附率均明显低于阴性对照组，P<0.01；而实验组与阳性对照组比较，均无明显差异，P>0.05。当血液标本流经两个不同的蛋白膜表面时，蜂胶提取液对血小板在纤维蛋白原膜表面粘附率的抑制作用更明显，P<0.01。结论： 蜂胶乙醇提取液能抑制血小板的活化，降低其在纤维蛋白原和胶原蛋白膜表面的粘附活性，对血小板与纤维蛋白原的作用更明显。     

通用血小板的研究

目的研究有效修饰血小板表面HLA的方法。方法采用浓度梯度法用mPEG修饰血小板表面HLA。通过微量淋巴细胞毒试验检测修饰效果,并对血小板功能进行检测。修饰后血小板输注到中国白兔体内检测血小板计数。结果mPEG可有效修饰血小板表面HLA,黏附与聚集能力分别由修饰前的(30.2±5.59)%和(1.43±0.74)%升至修饰后的(45.5±2.72)%,(3.86±1.21)%,Ca2 释放无显著差异。中国白兔输注修饰血小板24h时血小板升高指数及血小板回收率分别为69.93±11.20和(52.06±10.92)%。结论mPEG修饰可有效阻断血小板表面HLA与其相应抗体的结合,修饰后血小板黏附及聚集功能有所增强,Ca2 释放功能不受影响,中国白兔输注修饰后血小板计数增高。