三维连通多孔钛表面成骨能力的实验研究

目的：通过体外成骨细胞培养实验,评估单纯连通多孔钛材料和复合类骨磷灰石的连通多孔钛材料表面的成骨能力。方法：先将纯钛粉应用热等静压法制备出单纯连通多孔钛并分成2组（每组50件）,将其中一组按1.5倍模拟体液浸泡法制备出复合连通多孔钛。将两组多孔钛制成标准试件（5mm×5mm×4mm）并均置于24孔板内。取新生SD鼠颅骨的成骨细胞进行原代培养及传代,然后将传代后的成骨细胞接种于24孔板内的两组多孔钛试件中并继续培养。在培养期间进行细胞增殖性测定（MTT法,在培养第1、3、5、7、9天测定）以及碱性磷酸酶活性检测（在培养第7、14、21天测定）。培养7d后对2组多孔钛内的成骨细胞进行扫描电镜观察。结果：2组的MTT吸光值和ALP值均随着时间的延长而增加,但复合多孔钛组在MTT吸光值的增加幅度和速度以及ALP活性均优于单纯多孔钛组（P〈0.05）。培养7d后扫描电镜显示复合连通多孔钛试件内成骨细胞生长活跃,黏附牢靠。结论：三维连通多孔钛表面具备成骨活性,在多孔钛内壁复合类骨磷灰石后,这种成骨活性明显增强,更有利于成骨细胞在材料表面的黏附和增殖。     

锶磷灰石修复颌骨缺损的实验研究

目的以不同含锶量的锶磷灰石(Sr-HAP)植入动物体内,进行各项生物学测试,为该材料的临床实际应用作前期研究.方法将24只新西兰大白兔分为3组,双侧下颌角均造成约6mm×12mm×4mm的缺损,用10%、5%、0%的Sr-HAP分别予以修复,于1、3、6个月时随机处死一组分别进行尸解、光镜、扫描电镜、四环素荧光标记、定量组织学观察.结果锶磷灰石人工骨植入后无感染和排斥反应,术后材料的部分降解早,有部分诱导成骨现象,5%和10%的锶磷灰石成骨量与纯羟基磷灰石(0%)比较在统计学上有差异,而5%与10%的锶磷灰石成骨量统计学上差异无显著性.结论①锶磷灰石有良好的组织相容性、骨引导性及生物降解性,并可能具有一定程度的骨诱导性,锶的存在提高了新骨的总生成量,延长了新骨生成的总体时间和高峰期.②锶磷灰石具有良好的生物降解率和合适的生物降解速率,能获得较满意的骨缺损修复效果.     

Radiogenic free radicals in apatite: The influence of fluoride and hydroxide

Fluor-hydroxyapatites of varying fluoride and hydroxide contents were irradiated by soft x-rays at −188°C and examined by means of electron spin resonance spectroscopy. Variation in fluoride-hydroxide contents affected radical yield and resulted in the observation of two kinds of oxygen anion resonances: a doublet due to hydrogen hyperfine splitting and a singlet. At higher temperatures a spin transfer process became operative which enhanced the oxygen anion radical population. Increasing fluoride content was paralleled by decreasingg-values for the oxygen anion resonances, possibly attributable to increased delocalization of the unpaired spin.     

纤维多孔钛微球复合纳米锶磷灰石修复骨缺损的实验研究

目的 探讨纤维多孔钛微球复合纳米锶磷灰石修复骨缺损的能力及其作用机制.方法 6月龄雄性SD大鼠24只,体重(545±22)g.在双侧股骨髁部使用慢速钻钻取直径2 mm贯通双侧皮质的冠状轴洞性骨缺损.以纤维多孔钛微球复合纳米锶磷灰石填充左侧骨缺损,以单纯纤维多孔钛微球填充右侧.术后1、2、4、8周分别处死6只大鼠行X线、组织学及骨组织形态计量学观察,并进行比较分析.结果 影像学结果表明,两侧骨缺损修复效果均良好.组织学显示,纤维多孔钛微球允许骨长入,且左侧微球内新生骨多于右侧.骨组织形态计量学观察显示,随时间延长,左侧新生骨量逐渐增多,2、4、8周新生骨量存在差异,而4、8周时左侧与右侧的新生骨量比较,差异有统计学意义.结论 纤维多孔钛微球具有良好的生物相容性及骨传导性,可作为骨缺损修复的支架材料;纳米锶磷灰石可增强纤维多孔钛微球修复骨缺损的能力.     

X-ray diffraction patterns in human dentin, enamel and synthetic apatities related to Zn concentration

Abstract – The Crystalliazation of human dentin and enamel containing different concentrations of Zn was Studied using X-ray diffraction analysis. The concentrations of Ca, Mg, Mn, Fe, Zn, Cu, Go, Ni, Sr and Pb in the samples were determined by atomic absorption apectrophotomelry. The concetration foF was Assayed with a combination fluoride electrode. The increase of the Zn ceoncentration (ug/g) from 150 to 572 in dentin was found to intensify apatite refectins indicating changes paralled to c-axis.A slight increase parallel to a-axis (or better crystallization) of latices was demonstrated in both dentin and enarnel. The increase of Zn concentratin from 164 ug/g inenamel weakened 002 and 112 reflections. The effect of Zn on the crystallinitv of svnthetic apatite drepareda at 37°C was of the same kind as its effect onthe dentin.     

紫外线光照射促进微弧氧化纯钛诱导磷灰石形成及细胞矿化

目的评估紫外线照射效应对微弧氧化纯钛诱导磷灰石形成及细胞矿化的影响。 方法Ⅱ级商用纯钛片进行微弧氧化（MAO）处理,作为空白对照组,记为MAO;微弧氧化结合紫外线（UV）照射处理2 h的钛片作为实验组,记为MAO+UV 2 h。采用扫描电镜（SEM）观察钛片浸泡在DMEM/F12培养液中材料表面磷灰石形成情况;将钛片与大鼠脂肪间质干细胞矿化诱导条件下共培养,观察细胞矿化情况。 结果浸泡在培养液中21 d后,MAO组仅在SEM高倍镜下见少量散在微小磷灰石结晶颗粒;MAO+UV 2 h组颗粒明显增大增多且叠层沉积,除微弧氧化形成的孔径外周高点外,氧化膜层几乎全部被磷灰石晶体层覆盖,且孔径内沉积大量晶体使孔径明显缩小。SEM观察细胞矿化物的形成情况,发现MAO组未见明显矿化物形成,但MAO+UV 2 h组细胞材料表面可见较多针状结晶,能谱分析（EDS）提示为磷灰石结晶。 结论紫外线照射可增强微弧氧化纯钛表面在体外诱导磷灰石沉积的能力且促进脂肪间质干细胞的体外矿化。     

结石红外光谱自动分析系统在尿路结石成分分析中的应用

目的 评价红外光谱自动分析系统检测尿路结石成分的临床应用价值.方法 尿路结石标本1450例.男1032例,女418例.年龄6个月～88岁.男性平均年龄(41.7±15.3)岁,女性(42.0±15.6)岁.肾结石875例(60.34%),输尿管结石504例(34.76%),膀胱结石71例(4.90%).均采用LIIR型结石红外光谱自动分析系统分析.解析结果均行红外光谱人工解析验证,必要时辅以偏光显微镜、X线衍射或化学方法进行验证. 结果在结石总体构成比上,一水草酸钙结石714例(49.24%),碳酸磷灰石结石444例(30.62%),无水尿酸结石93例(6.41%),二水草酸钙结石92例(6.34%),六水磷酸铵镁结石28例(1.93%),胱氨酸结石23例(1.59%),尿酸铵结石20例(1.38%),二水尿酸结石16例(1.10%),二水磷酸氢钙结石12例(0.83%),一水尿酸钠结石2例(0.14%),碳酸钙结石1例(0.07%),其他5例(0.34%).结石的组合成分上,混合性结石1053例(72.62%),单一成分结石仅397例(27.38%).混合性结石主要为含钙类结石.其中15例婴幼儿结石为食用三聚氰胺污染奶粉所致,成分为二水尿酸与尿酸铵的混合结石.验证结果表明,结石主要成分误检6例(0.41%),将无水尿酸误检为尿酸铵或碳酸磷灰石;漏检9例(0.62%),其中漏检六水磷酸铵镁或碳酸磷灰石7例,性质不明2例.在2种和3种成分的混合性结石中,含量相对低的成分各漏检6例和10例,均为六水磷酸铵镁或碳酸磷灰石. 结论结石红外光谱自动分析系统分析尿路结石成分具有准确、自动、快捷等优点,适合临床常规使用.

Abstract：

Objective To determine the value of applying LIIR Automatic Analysis System of Infrared Spectroscopy in analyzing urinary stone composition. Methods 1450 samples of urinary stones were collected from 1032 male and 418 female patients. The age of patients ranged from 6 months to 88 years. The mean ages were 41.7±15.3 and 42.0±15.6 years for male and female patients, respectively. Of 1450 stones, 875 cases were located in kidney (60.34%), 504 cases in ureter (34.76%) and 71 cases in bladder (4.90%). All stones were analyzed by LIIR Automatic Analysis System of Infrared Spectroscopy (Tianjin). Analysis results were reevaluated by the artificial analysis of spectrogram, if necessary, with polarization microscope, chemical analysis, and X-ray diffraction.Results Calcium oxalate monohydrate stones were found in 714 cases (49. 24%), carbonate apatite stones in 444 cases (30.62%), anhydrous uric acid stones in 93 cases (6.41%), calcium oxalate dihydrate stones in 92 cases (6. 34 % ), ammonium magnesium phosphate hexahydrate stones in 28 cases (1.93%), cystine stones in 23 cases (1.59%), ammonium urate stones in 20 cases (1.38%), uric acid dihydrate stones in 16 cases (1.10%), brushite stones in 12 cases (0.83%), sodium urate monohydrate stones in 2 cases (0. 14%), calcium carbonate stones in 1 cases (0. 07%), and other stone types in 5 cases (0. 34%). Most urinary stones were composed of 2 or more compositions, and pure stones were only observed in 397 cases (27.38%). Most of the mixed stones contained calcium and non-calcium mixed stone was rarely observed. In addition, 15 stones were found in infants who had consumed melamine-contaminated milk powder. These stones were composed of uric acid dihydrate and ammonium urate. The results of reevaluation by artificial analysis showed the following: among pure and mixed stones, false detection occurred in 6 cases (0.41%), of which the composition was ammonium urate or carbonate apatite determined by automatic system but the true composition was anhydrous uric acid. False negative detection occurred in 9 cases (0.62%), of which the composition was ammonium magnesium phosphate hexahydrate or carbonate apatite in 7 cases, but in other 2 cases the composition could not be determined by artificial analysis. The false negative detection of components with relatively low content occurred in 6 cases and 10 cases in stones with 2 components and 3 components, respectively. The undetected composition in these cases was ammonium magnesium phosphate hexahydrate or carbonate apatite. Conclusion Automatic Analysis System of Infrared Spectroscopy has many advantages in accuracy, automation and is quick in analyzing the composition of urinary stones, and is worthy of promotion in clinical use.     

牙釉质纳米微晶龋溶解的高分辨电镜观察

目的 在晶格水平上探讨牙釉质磷灰石纳米微晶的龋溶解机制及其与釉质微晶中心暗线的关系。方法 应用高分辨透射电镜结合氩离子减薄制样技术，对初期釉质龋病变体部的晶体结构进行观察。结果 在初期釉质龋的病变体部，釉质纳米微晶主要以中心优先溶解的方式溶解，偶见晶体周边溶解现象。单个釉质微晶的初期溶解首先表现为沿微晶中心暗线的多个亮斑，其晶格条纹模糊、弯曲或断裂，邻近亮斑可相互融合形成大的亮区，进而形成微晶的中心穿孔。龋溶解微晶的中心穿孔与中心暗线的出现部位相符，并可见中心穿孔沿中心暗线延伸。结论 牙釉质纳米微晶的初期龋溶解与品格缺陷密切相关；微晶中心优先溶解现象可部分归因于晶体的中心暗线，中心暗线可能显示微晶对龋溶解较为敏感的区域。     

Radiation induced free radicals as molecular probes in synthetic apatites

Summary Free radicals generated in synthetic apatitic calcium phosphates by X-ray radiation were investigated by electron spin resonance (ESR) spectroscopy. Among the species stable enough at –188° C to be identified were hydrogen atoms, phosphate radicals, and oxygen anion radicals. The ESR spectra were markedly dependent on the specific surface of the mineral. Oxygen radicals dominated the spectra of low specific surface samples while phosphate radicals were the predominant species at higher specific surfaces. Our studies suggest that the oxygen radicals are more stable in the bulk of the crystal while the hydrogen atoms and the phosphate radicals are stabilized at or near the crystal surface. It was concluded that the surface species are potentially capable of serving as probes of biologically relevant mineral-organic interfaces.