正常人高分辨率CT中耳三维有限元建模方法

目的探索根据正常人颞骨高分辨率CT二维图像建立中耳三维有限元实体模型的方法。方法获得无中耳传音结构病变志愿者高分辨颞骨CT资料,使用Photoshop、Amira、HyperMesh及Abaqus软件根据二维CT图像建立中耳三维有限元实体模型。结果建立了包含鼓膜、听骨链的中耳三维有限元实体模型,模型几何尺寸在正常解剖数据范围内。结论探索出一种基于正常人颞骨高分辨率CT二维图像的中耳三维有限元实体建模方法,具有快捷、方便、廉价、无创性的优点,为进一步进行中耳声音传导机制有限元分析奠定了基础。     

同步辐射在显微CT中的应用

计算机X射线断层成像技术(CT)是利用X射线的穿透能力对物体进行扫描,所得信号经过反投影的算法而得到物体二维分布的一种成像方法,已经在医学诊断、工业探伤等领域广泛应用.但是由于实验室光源的低通量,光源点大小及其单色性等限制了其向高分辨发展,通常其分辨率在0.5mm左右.利用微焦点X射线源作为光源的显微CT分辨率可以达到微米量级,但是由于其光通量低且为非单色光,对不同样品有不同程度的束线硬化,影响了其真实分辨率.同步辐射作为一种新兴的光源有高亮度、高光子通量、高准直性、高极化性、高相干性及宽的频谱范围的特点,配合高分辨的X射线探测器,可以发展同步辐射显微CT,其分辨率可达10μm以下.利用同步辐射的高空间相干性开展位相衬度显微CT的研究,对低吸收物质也可以清晰三维成像.新建的上海光源的X射线成像及生物医学应用线站开展了三维显微CT方面的研究,经过初步试验,得到了较好的结果.     

大鼠脑微血管内皮细胞的培养

目的:探索一种简便易行、可培养出高纯度大鼠脑微血管内皮细胞的方法。方法:1月龄SD大鼠,解剖得到大脑皮质,密度离心法获得较纯的脑微血管段后进行原代培养,传代采用差速消化和贴壁方法进行纯化。通过形态学观察及第Ⅷ因子相关抗原免疫荧光检测对培养细胞进行鉴定。结果:密度离心法分离出的大量微血管段呈"串珠样"结构,培养24h可见短梭形、多角形细胞,8～10天基本融合。第2代细胞经免疫荧光染色,第Ⅷ因子相关抗原呈阳性,阳性率达90%。结论:原代细胞采用低分子量葡聚糖加Percoll密度离心法、传代细胞采用差速消化和差速贴壁法纯化可成功培养高纯度的脑微血管内皮细胞。     

人体皮肤微血管构筑的三维可视化

背景：常用的血管解剖学研究方法如逐层解剖、血管染色、造影摄片可以确定血管的位置、大至供血范围等,但难以显示皮肤微血管立体构筑。 目的：建立三维的皮肤微血管构筑模型,以评估和设计穿支皮瓣。 方法：选取2具新鲜成人尸体标本,以羧甲基纤维素明胶氧化铅灌注标识血管,CT扫描获取标本灌注前后及剥离皮肤序列图像数据,利用Mimics13.1软件进行皮肤微血管三维重建和穿支皮瓣设计。 结果与结论：实验成功重建了骨骼、血管、皮肤三维数字模型,并选择性设计了旋股外侧动脉皮瓣和旋肱后动脉的主要穿支皮瓣。构建的皮肤微血管模型不仅可显示皮穿支的长度管径、立体位置、走行方向、分布范围、毗邻关系,还可追踪其来源血管,与来源血管、骨骼、皮肤等搭配显示。说明皮肤微血管构筑可揭示穿支皮瓣的范围和扩张方向,有利于穿支皮瓣的设计发掘、血供评估。     

应用单宁酸的负染色效果显示大鼠生殖器官微血管

近百年来,许多学者为研究器官内血管立体构筑倾注了大量心血,创造了多种显示微血管构筑的方法,诸如墨汁灌注法,橡胶、维尼龙血管、淋巴管立体铸型法,微血管铸型扫描电镜法,碱性磷酸酶法（钙铅法）以及单宁酸-氯化铁媒染法（TA-Fe法）,为科学研究及临床应用做出了贡献。继TA-Fe法媒染微血管后,我们又发现单宁酸过度媒染某些组织结构,有类似电镜标本负染色技术效果,清晰地显示了大鼠子宫、卵巢、输卵管等器官的血管构筑特点。     

先天性内耳发育畸形的高分辨率CT表现

目的探讨先天性内耳畸形的高分辨率CT表现。方法回顾性分析29例(46耳)婴幼儿先天性内耳发育畸形患者的CT表现,所有患者均做多层螺旋高分辨率CT横断面扫描及多平面重建,必要者利用容积再现技术对骨迷路进行三维重建。结果29例先天性内耳发育畸形患者双侧畸形者17例,单侧畸形者12例,内耳发育畸形共计46耳。具体分布如下:(1)Michel型(2耳),(2)耳蜗未发育(6耳),(3)共同腔畸形(5耳),(4)不完全分隔Ⅰ型(5耳),(5)不完全分隔Ⅱ型(传统Mondini型)(17耳),(6)耳蜗形态正常仅前庭及(或)半规管畸形(9耳),(7)单纯内耳道畸形(2耳)。结论高分辨率CT对先天性内耳骨迷路畸形具有重要的诊断价值,并可为人工耳蜗植入术适应证的选择提供重要依据。     

大鼠脑微血管内皮细胞的原代培养

目的分离、培养原代脑微血管内皮细胞,建立体外血脑屏障模型。同时探索高纯度、活性好的脑微血管内皮细胞的分离培养方法。方法取3周大鼠大脑,分离皮质,经过匀浆、葡聚糖离心以及消化后,取纯度较高的脑微血管段种植于胶原蛋白包被过的塑料培养瓶中进行培养。显微镜观察及检测Ⅷ因子相关抗原。结果镜下细胞呈长梭形。7d左右细胞可融合,Ⅷ因子相关抗原免疫组化检测为阳性．且阳性细胞占绝大部分。结论本实验成功分离大鼠脑微血管内皮细胞,并进行原代培养,为脑微血管内皮细胞的进一步研究提供了模型．也为构建更高级的大鼠体外血脑屏障奠定基础。     

基于三维血管重建的高分辨率CT图像孤立性肺结节提取

肺癌是人类的一大杀手,为了提高其治愈率,人们越来越重视对肺癌的早期形态——肺结节的影像检测,但一直被较高的假阳性率所困扰。在高分辨率CT图像基础上,打破常规思维,从肺部血管三维重建入手,间接去掉血管组织对结节提取的干扰。首先利用数学形态学及凸包算法获得二维完整肺实质,再利用区域增长法提取肺部软组织,间接得到疑似结节图像,然后利用三维Hessian矩阵特征值的几何意义,构造三维血管结构的增强因子,得到完整的肺部血管图像,将其与疑似结节图像进行对比,重合区域即可除去,最大限度地剔除血管的干扰,最后再利用疑似区域的几何特征剔除残余的肺部杂质,最终获得较低的假阳性率,提取准确率较高。     

大鼠视神经内微血管的三维构筑

目的:研究大鼠视神经内血管分布规律.方法:用10%明胶-墨汁混合液经心灌注SD大鼠后取出其视神经,OCT包埋,20μm连续切片,Olympus图像处理系统拍照,用Photoshop 9.0 cs对图像进行处理并用Image-J软件进行分析.用Amira 3.1.1软件将二维切片图像重建成三维可视化图像.结果:三维重建及图像分析显示大鼠视神经内血管围绕神经束排列,球后0～5 mm、5～8 mm、8 mm至视交叉的视神经内血管网形度大于0.5的百分比分别为(55.5±2.7)%、(67.4±4.6)%、(76.8±1.7)%.结论:大鼠视神经内的微血管数量多,走行变化大,从球后到视交叉沿视神经轴由横行逐渐变为纵行.     

高分辨率CT在眼外伤诊断中的应用价值

眼外伤是临床常见的眼科疾病，随着CT的普及府用，大大提高了眼外伤的诊断率，CT已成为眼外伤临床诊断不可缺少的一项检查手段。回顾我院150例眼外伤患者的高分辨率CT（HRCT）检查结果进行分析总结如下。     

Microvascularization of the human central and peripheral nervous system: A new microcomputed tomography method

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Rapid three-dimensional quantification of VEGF-induced scaffold neovascularisation by microcomputed tomography

Microcomputed tomography (micro-CT) is increasingly being used to analyze the three-dimensional structure and architecture of microvascular networks. Therefore we have evaluated a micro-CT analysis of VEGF-induced vessel ingrowth into a porous polyurethane scaffold through comparison with analyses by CD31 immunohistochemistry, vascular perfusion by intravital Lycopersicon esculentum lectin perfusion and vascular corrosion casting. Micro-CT scanning found a similar level of vascularisation within the VEGF treated scaffolds to that determined by the other analytical methods. However, although the relative increase in vascularisation (17 fold above PBS controls p < 0.05) induced by VEGF determined by micro-CT was similar to the perfusion based analyses (20.1 and 10.4 fold for lectin perfusion and vascular corrosion respectively p < 0.05), it differed substantially from that determined by CD31 immunohistochemistry (3.2 fold p < 0.05). This difference was due to a large proportion of unperfused vessels in the PBS control that were not present in the VEGF group. The increase in perfusion probably resulted in part from an increase in average vessel diameter. Though this increase was detected by micro-CT, the actual diameters were overestimated by 60–90% most likely as a consequence of a merging effect for juxtaposed vessels. Thus whilst micro-CT gives an accurate three-dimensional quantification of the VEGF-induced increase in perfused vessels, resolution needs to be maximized for accurate sizing of a microvascular network's components.     

胎儿神经加自体雪旺氏细胞桥接周围神经缺损的实验研究

目的 探讨自体雪旺氏细胞植入胎儿神经后修复周围神经缺损的效果,寻找替代自体神经移植的材料。方法 用Wistar大鼠80只切断左侧大腿坐骨神经,造成15mm缺损,分别用自体神经(A组),液氮冷冻胎儿神经(B组),液氮冷冻胎儿神经加自体雪旺氏细胞粗制品(C组)进行桥接。于术后4、12、24周取桥体、桥体远端坐骨神经,分别行电镜、光镜观察、图像分析和电生理检测,所得数据经单因素方差分析和q检验。结果 A组和C组间有髓纤维数目、无髓纤维数目、复合动作电位峰值恢复率、传导速度恢复率均无显著差异,两组神经再生效果相近,而B组的再生效果则不及A、C两组;B组与A组,B组与C组分别作两两比较,部分指标存在显著差异(P<0.01)。结论 作者认为植入自体雪旺氏细胞的胎儿神经桥接周围神经缺损优于单纯胎儿神经桥接,是一种良好的替代自体神经的桥接物,有进一步研究价值和临床应用前景。     

Development and evaluation of silk fibroin-based nerve grafts used for peripheral nerve regeneration

Silk fibroin (SF), derived from natural silk long used as a textile material, has recently become an important biomaterial for tissue engineering applications. We have previously reported on good in vitro biocompatibility of SF fibers with peripheral nerve tissues and cells. In the present study, we developed a novel biomimetic design of the SF-based nerve graft (SF graft) which was composed of a SF-nerve guidance conduit (NGC) inserted with oriented SF filaments. The SF-NGC prepared via well-established procedures exhibits an eggshell-like microstructure that is responsible for its superior mechanical and permeable properties beneficial to nerve regeneration. The SF graft was used for bridge implantation across a 10-mm long sciatic nerve defect in rats, and the outcome of peripheral nerve repair at 6 months post-implantation was evaluated by a combination of electrophysiological assessment, FluoroGold retrograde tracing and histological investigation. The examined functional and morphological parameters show that SF grafts could promote peripheral nerve regeneration with effects approaching those elicited by nerve autografts which are generally considered as the gold standard for treating large peripheral nerve defects, thus raising a potential possibility of using these newly developed nerve grafts as a promising alternative to nerve autografts.     

Three-dimensional visualization of bioactive glass-bone integration in a rabbit tibia model using synchrotron X-ray microcomputed tomography

Synchrotron X-ray microcomputed tomography (SR microCT), with a micron resolution, was used to evaluate the osteoconduction and osteointegration by borate bioactive glass after implantation 12 weeks in a rabbit tibia model. The study focused on the biomaterial-bone interface. Results from SR microCT two-dimensional and three-dimensional (3D) reconstructions provided precise imaging of the biomaterial-bone integration and detailed microarchitecture of both the bone-like glass graft and the newly formed trabecular bone. Osteoconduction, the formation of new trabecular bone within a tibia defect, occurred only in the tibiae implanted with teicoplanin-loaded borate glass but not in those with teicoplanin-loaded CaSO(4) beads, indicating the excellent biocompatibility of the glass implants. 3D reconstruction of the tibiae also showed the infiltration of vascular tissue in both the bioactive glass graft and the new trabecular bone. This study indicates that SR microCT can serve as a valuable complementary technique for imaging bone repair when using bioactive glass implants.     

周围神经损伤后局部一次给予重组CNTF对神经元变性和再生的作用

目的 :研究周围神经损伤后 ,局部一次给予重组CNTF对神经元变性和再生的作用。方法 :用硅管套接切断的成年大鼠坐骨神经 ,术时在损伤神经局部一次性给予重组CNTF ;用甲苯胺蓝染色和胆碱酯酶组织化学方法研究神经元的逆行变性 ,用HRP逆行追踪研究轴突的再生 ,并进行后足功能测试。结果 :重组CNTF减轻损伤运动神经元胞核偏位和胆碱酯酶活性的变化 ,增加轴突再生的运动神经元数量 ,改善功能指数。结论 :局部一次给予重组CNTF和再加皮下注射一样能保护损伤运动神经元并促其轴突再生。     

The promotion of peripheral nerve regeneration by chitooligosaccharides in the rat nerve crush injury model

Chitooligosaccharides (COSs), the biodegradation product of chitosan, have shown many biological functions. In this study, we examined the possible benefits of treatment with COSs (M.W. 800) on regeneration of rat crushed sciatic nerves. The rats with sciatic nerve crush injury were administered intraperitoneally daily with 3 or 6 mg/kg body weight of COSs over a 3-week period. During and at the end of COSs treatment, a series of functional and histological examinations, including the measurement of withdrawal reflex latency (WRL) values, walking track analysis, electrophysiological assessments, morphometric analysis of gastrocnemius muscle, as well as immunohistochemistry and electromicroscopy to regenerated sciatic nerves, were performed to evaluate the therapeutic outcomes of COSs. The experimental data demonstrated that COSs promoted peripheral nerve regeneration with the desired functional recovery in the rat sciatic nerve crush injury model. This study raises a possibility of developing COSs as a potential neuroprotective agent for peripheral nerve repair applications.     

低照度激光辐射周围神经组织损伤修复的研究进展

周围神经损伤修复是神经组织损伤康复研究领域中的一项重要课题.目前,周围神经损伤治疗的新技术很多,随着激光对生物作用机制研究的发展,低照度激光辐射周围神经组织损伤修复作为一种新的组织再生方法被应用到神经损伤修复领域.主要围绕弱激光照射神经组织修复机制以及周围神经损伤后功能恢复和神经组织部位瘢痕抑制进行论述,并对激光照射神经损伤治疗和修复的新进展作一综述.     

A bioengineered peripheral nerve construct using aligned peptide amphiphile nanofibers

Peripheral nerve injuries can result in lifelong disability. Primary coaptation is the treatment of choice when the gap between transected nerve ends is short. Long nerve gaps seen in more complex injuries often require autologous nerve grafts or nerve conduits implemented into the repair. Nerve grafts, however, cause morbidity and functional loss at donor sites, which are limited in number. Nerve conduits, in turn, lack an internal scaffold to support and guide axonal regeneration, resulting in decreased efficacy over longer nerve gap lengths. By comparison, peptide amphiphiles (PAs) are molecules that can self-assemble into nanofibers, which can be aligned to mimic the native architecture of peripheral nerve. As such, they represent a potential substrate for use in a bioengineered nerve graft substitute. To examine this, we cultured Schwann cells with bioactive PAs (RGDS-PA, IKVAV-PA) to determine their ability to attach to and proliferate within the biomaterial. Next, we devised a PA construct for use in a peripheral nerve critical sized defect model. Rat sciatic nerve defects were created and reconstructed with autologous nerve, PLGA conduits filled with various forms of aligned PAs, or left unrepaired. Motor and sensory recovery were determined and compared among groups. Our results demonstrate that Schwann cells are able to adhere to and proliferate in aligned PA gels, with greater efficacy in bioactive PAs compared to the backbone-PA alone. In vivo testing revealed recovery of motor and sensory function in animals treated with conduit/PA constructs comparable to animals treated with autologous nerve grafts. Functional recovery in conduit/PA and autologous graft groups was significantly faster than in animals treated with empty PLGA conduits. Histological examinations also demonstrated increased axonal and Schwann cell regeneration within the reconstructed nerve gap in animals treated with conduit/PA constructs. These results indicate that PA nanofibers may represent a promising biomaterial for use in bioengineered peripheral nerve repair.