下肢动脉阻塞性病变多层螺旋CT低剂量扫描成像初探

目的：探讨低剂量CT扫描在下肢动脉脉阻塞性病变诊断中的应用价值。方法：选择127段经DSA确诊的不同部位下肢动脉阻塞性病变行低剂量CT扫描,并采用MPR,VR,MIP等重建方法获得各下肢动脉CTA图像,将CTA图像与DSA图像的诊断结果利用统计学软件SAS8.1行加权Kappa一致性检验,检验水准为：Kaapa.系数大于0.75。结果：所得CTA图像与DSA图像诊断结果的一致性检验的kappa系数为0.8058,两种诊断结果的一致性为优。结论：采用低剂量扫描条件获得高质量的CTA图像在下肢动脉阻塞性病变的诊断上有肯定的价值。     

前交通动脉复合体的显微外科解剖研究

目的:通过手术显微镜对前交通动脉复合体及穿支进行解剖和测量,进一步熟悉和掌握该复合体的结构及毗邻血管的走行,为前交通动脉瘤手术提供解剖学依据.方法:用红色乳胶经颈内动脉对15例(30侧)福尔马林固定的湿性尸头进行灌注,然后在手术显微镜下对前交通动脉复合体进行解剖观测,所得结果用SPSS17.0软件进行统计分析.测量大脑前动脉A1和A2段、前交通动脉、Heubner回返动脉、A1段和前交通动脉穿支的长度、直径和各种形态变异.结果:未经选择的标本双侧A1发育无明显差异;术中对Heubner回返动脉、A1段穿支、前交通动脉穿支应仔细分辨加以保护;A1中1/3段穿支少,可作为前交通动脉瘤手术时临时阻断A1的部位;血管造影时前交通动脉不易看清与多种因素有关.结论:前交通动脉复合体复杂多变,熟悉前交通动脉复合体及穿支的解剖特点,对外科医生处理该区疾病至关重要.

Abstract：

Objective:To investigate the anatomy structure and adjacent vessels by investigating the anterior communicating artery complex and its perforating branches under an surgery microscope, in order to, to provide anatomical datas for anterior communicating aneurysms. Method: A total of 15 adult cadaveric heads (30 cerebral hemispheres) fixed with formalin were used, red latex was injected into internal carotid artery. Anterior communicating artery complexes were dissected, detected by surgery microscope.The results were analyzed with SPSS 17.0 statistical software. The lengthes, diameters and variations of the anterior cerebral artery(ACA)A 1 segment, A2 segment, anterior communicating artery (AComA), Heubner recurrent artery(HRA), perforating branches of A1 segment and AcomA were measured. Result:There were no statistically significant differences between two sides of A1 segment in length and diameter. HRA, perforating branches of Al segment and AComA should be carefully recognized and protected during the operation on anterior communicating aneurysms. The middle 1/3 of A1 segment which had less perforating branches was the best position for temporary occlusion during the operation on anterior communicating aneurysms. It is difficult to distinguish AComA in cerebral angiography. Conclusion: The anterior communicating artery complex was regarded as the most complex. Being familiar with the anatomy of the anterior communicating artery complex and the perforating branches enabled neurosurgeons to handle the diseases in this area efficiently.     

Artery regional properties and atherosclerosis susceptibility

White carneau (WC) pigeons develop spontaneous atherosclerosis in contrast to atherosclerosis-resistant show racer (SR) pigeons. In this study, cellular and extracellular components and smooth muscle cell (SMC) proliferation rates of specific aortic sites were assessed in both breeds of pigeons prior to lesion development. The atherosclerosis-susceptible site of the WC aorta was characterized by larger lumen diameter without accompanying increase in wall thickness, as well as by SMC hypocellularity, increased proteoglycan content and higher elastin content. For both breeds, cells derived from the lesion site had lower proliferation rates compared to proximal aortic control sites. WC cells had greater proliferation rates than SR cells (109% greater at the atherosclerosis-prone site and 133% greater at the control site). Fibroblast growth factor (FGF) increased the proliferation of WC lesion site cells compared to SR cells (79% vs. 35%); whereas, transforming growth factor beta (TGFbeta) reduced growth in SR but not in WC cells. Differences in hemodynamic properties, in cell-matrix, elastin, proteoglycan and proliferation rates of cells and responses to FGF and TGFbeta in cells of the atherosclerosis-prone area have been identified as potential contributors to the enhanced atherosclerosis potential of this site in WC pigeons.     

Buckling of adaptive elastic bone-plate: theoretical and numerical investigation

During day-to-day activities, many bones in the axial and appendicular skeleton are subjected to repetitive, cyclic loading that often results directly in an increased risk of bone fracture. In clinical orthopedics, trabecular fatigue fractures are observed as compressive stress fractures in the proximal femur, vertebrae, calcaneus and tibia, that are often preceded by buckling and bending of microstructural elements (Müller et al. in J Biomechanics 31:150 1998; Gibson in J Biomechanics 18:317-328 1985; Gibson and Ashby in Cellular solids 1997; Lotz et al. in Osteoporos Int 5:252-261 1995; Carter and Hayes in Science 194:1174-1176 1976). However, the relative importance of bone density and architecture in the etiology of these fractures are poorly understood and consequently not investigated from a biomechanical point of view. In the present contribution, an attempt is made to formulate a bone-plate buckling theory using Cowin's concepts of adaptive elasticity (Cowin and Hegedus in J Elast 6:313-325 1976; Hegedus and Cowin J Elast 6:337-352 1976). In particular, the buckling problem of a Kirchhoff-Love bone plate is investigated numerically by using the finite difference method and an iterative solving approach (Chen in Comput Methods Appl Mech Eng 167:91-99 1998; Hildebland in Introduction to numerical analysis 1974; Richtmyer and Morton in Difference methods for initial-value problems 1967).     

Proteomic dataset of mouse aortic smooth muscle cells

In an accompanying study (in this issue, DOI 10.1002/pmic.200402044), we have characterised the proteome of Sca-1(+) progenitor cells, which may function as precursors of vascular smooth muscle cells (SMCs). In the present study, we have analysed and mapped protein expression in aortic SMCs of mice, using 2-DE, MALDI-TOF MS and MS/MS. The 2-D system comprised a non-linear immobilised pH 3-10 gradient in the first dimension (separating proteins with pI values of pH 3-10), and 12%T SDS-PAGE in the second dimension (separating proteins in the range 15,000-150,000 Da). Of the 2400 spots visualised, a subset of 267 protein spots was analysed, with 235 protein spots being identified corresponding to 154 unique proteins. The data presented here are the first map of aortic SMCs and the most extensive analysis of SMC proteins published so far. This valuable tool should provide a basis for comparative studies of protein expression in vascular smooth muscle of transgenic mice and is available on our website hhtp://www.vascular-proteomics.com.     

国产真丝涤纶血管移植物自然内皮化的研究

采用真丝涤纶人造血管行腹主动脉移植,结果显示,术后１０天吻合口管壁有较完整的纤维组织性吻合,并有内皮细胞覆盖,血管内壁有血细胞形成的一薄层血栓覆盖,１０天后开始机化学变成纤维组织,逐渐被内皮细胞覆盖,术后１个月移植血管内形成完整的内皮,但并不完善,３个月血管内皮才被一单层内皮细胞完整覆盖。     

A deficiency of the GluN2C subunit of the N-methyl-D-aspartate receptor is neuroprotective in a mouse model of ischemic stroke

The N-methyl-D-aspartate receptor (NMDAR) ion channel plays a pivotal role in the pathology of ischemic stroke. The functional receptor consists of two GluN1 subunits (a-h) and two GluN2 subunits (A/B/C/D), the expression of which are spatially and temporally regulated in pathological and physiological conditions. While the roles of the GluN2A and GluN2B subunit in ischemic stroke have been well developed, the role of the GluN2C subunit in ischemia is not well understood. Following middle carotid artery occlusion (MCAO), GluN2C^-/- male mice displayed similar volumes of infarct as wild-type (WT) mice. However, GluN2C^-/- mice showed decreased cerebral edema and an enhanced rate of neurological recovery compared to WT mice. The ischemic penumbra of GluN2C^-/- mice showed fewer cytoarchitectural deficits and decreased tauopathy relative to WT mice. These neuroprotective changes in GluN2C^-/- mice also corresponded with decreased expression of Fyn kinase and decreased phosphorylation of GluN2B subunit at Tyr1336. Lastly, a GluN2C deficiency modified the NMDAR/pro-survival signaling axis, as shown by increased levels of nuclear CREB(P-Ser133). Thus, the GluN2C subunit enhances ischemic stroke pathology by promoting neuronal dysfunction in the penumbra region.     

A biomechanical model for fibril recruitment: Evaluation in tendons and arteries

Simulations of soft tissue mechanobiological behaviour are increasingly important for clinical prediction of aneurysm, tendinopathy and other disorders. Mechanical behaviour at low stretches is governed by fibril straightening, transitioning into load-bearing at recruitment stretch, resulting in a tissue stiffening effect. Previous investigations have suggested theoretical relationships between stress-stretch measurements and recruitment probability density function (PDF) but not derived these rigorously nor evaluated these experimentally. Other work has proposed image-based methods for measurement of recruitment but made use of arbitrary fibril critical straightness parameters. The aim of this work was to provide a sound theoretical basis for estimating recruitment PDF from stress-stretch measurements and to evaluate this relationship using image-based methods, clearly motivating the choice of fibril critical straightness parameter in rat tail tendon and porcine artery. Rigorous derivation showed that the recruitment PDF may be estimated from the second stretch derivative of the first Piola-Kirchoff tissue stress. Image-based fibril recruitment identified the fibril straightness parameter that maximised Pearson correlation coefficients (PCC) with estimated PDFs. Using these critical straightness parameters the new method for estimating recruitment PDF showed a PCC with image-based measures of 0.915 and 0.933 for tendons and arteries respectively. This method may be used for accurate estimation of fibril recruitment PDF in mechanobiological simulation where fibril-level mechanical parameters are important for predicting cell behaviour.     

Effects of the cross-linkers on the buckling of microtubules in cells

In cells, the protein cross-linkers lead to a distinct buckling behavior of microtubules (MTs) different from the buckling of individual MTs. This paper thus aims to examine this issue via the molecular structural mechanics (MSM) simulations. The transition of buckling responses was captured as the two-dimensional-linkers were replaced by the three-dimensional (3D) ones. Then, the effects of the radial orientation and the axial density of the 3D-linkers were examined, showing that more uniform distribution of the radial orientation leads to the higher critical load with 3D buckling modes, while the inhomogeneity of the axial density results in the localized buckling patterns. The results demonstrated the important role of the cross-linker in regulating MT stiffness, revealed the physics of the experimentally observed localized buckling and these results will pave the way to a new multi-component mechanics model for whole cells.     

Immunofluorescent localization of type-V collagen as a fibrillar component of the interstitial connective tissue of human oral mucosa,artery and liver

Summary Polyclonal antibodies against native human typeV collagen were produced in rabbits and goats. Following purification, crossreaction of the antibodies with highly immunogenic peptides of basement membranes or the interstitial matrix was excluded on the basis of sensitive radioimmunoassays. These antibodies, when applied to cryostat sections of human oral mucosa, liver and arterial walls, never stained basement membranes as did antibodies against type-IV collagen or laminin. On the contrary, we observed delicate arborizing fibers in the interstitial compartment with extensions contacting structures such as subepidermal basement membranes. Arterioles contained a unilamellar sheath of longitudinally oriented fibers limited to the intimal layer. Larger arteries exhibited a multilamellar fibrous fluorescence over the whole intima, whereas the media showed a much weaker staining. The data identified type-V collagen as an interstitial fibrillar collagen rather than a basement membrane collagen, with a tissue pattern completely different from that of collagens types I, III, VI or fibronectin. A reinterpretation of the role of type-V collagen in connective tissue function is warranted.