生物衍生骨复合骨髓基质干细胞修复山羊胫骨缺损的血管化研究

目的研究生物衍生骨与骨髓基质干细胞(marrow stromal stem cells, MSCs)复合修复山羊胫骨缺损的血管化过程,了解其修复长段管状负重骨缺损的血管化情况. 方法制备生物衍生骨作为支架材料,培养、诱导MSCs作为种子细胞,二者在体外复合构建组织工程骨.20只山羊双侧胫骨中段制备成20 mm长的骨-骨膜缺损模型,采取自身左右侧对照,实验侧(右侧)缺损处植入组织工程骨,对照侧(左侧)植入单纯支架材料,采用钢板内固定.术后2、4、6及8周用墨汁灌注透明标本及血管面积图像分析方法观察血管化过程,组织学观察血管形成及成骨情况. 结果术后2、4周,实验侧血管形成较对照侧少(P<0.05);术后8周,两侧均完全血管化,差异无统计学意义(P>0.05).实验侧于术后6、8周新骨形成逐渐增加,材料降解吸收较对照组快;对照侧术后8周材料孔隙内仍无明显新骨形成. 结论生物衍生骨作为骨组织工程的支架材料,能够较快发生血管化;组织工程骨成骨能力较单纯支架材料强.     

Expression and distribution of vascular endothelial growth factor protein in human brain tumors

Marked neovascularization is a hallmark of many neoplasms in the nervous system. Recent reports indicate that the endothelial mitogen vascular endothelial growth factor (VEGF) may play a critical role in the regulation of vascular endothelial proliferation in malignant gliomas. Using novel monoclonal antibodies to the VEGF polypeptide we have determined the expression and cellular distribution of VEGF protein in a representative series of 171 human central nervous system (CNS) tumors by immunohistochemistry and immunoblotting. In agreement with previous in situ hybridization data, 19 out of 20 glioblastomas (95%) showed immunoreactivity for VEGF, whereas both the percentage of immunoreactive tumors and the extent of immunoreactivity for VEGF were significantly lower in astrocytomas. Of the pilocytic astrocytomas (WHO grade I) 44% were immunoreactive for VEGF, but we observed several cases with pronounced vascular proliferates in the absence of VEGF. In ependymomas, meningiomas, hemangioblastomas, and primitive neuroectodermal tumors, there was no correlation between VEGF expression, vascular endothelial proliferation and the grade of malignancy. Oligodendrogliomas and the oligodendroglial component of mixed gliomas lacked immunoreactive VEGF, indicating that endothelial growth factors other than VEGF may regulate tumor angiogenesis in these neoplasms. Western blot analysis showed a predominant VEGF protein species of 23 kDa and confirmed the immunohistochemical data in all cases. Our findings demonstrate that VEGF is expressed in a wide spectrum of brain tumors in which it may induce neovascularization. However, other angiogenic factors also appear to contribute to the vascularization of CNS neoplasms. Received: 18 April 1996 / Revised, accepted: 20 August 1996     

Upper tibial corticocancellous flap anatomy study (19.2.93)

Summary A cortico-cancellous flap from the anterolateral aspect of the upper third of the tibia was presented. Sixty lower limbs of fresh cadavers were dissected. The vascular bundle includes the anterior tibial artery and its recurrent collateral branches and recurrent and muscllo periostal arteries. The flap is harvested with the interosseous membrane and can be used either free or pedicled. We used this flap for two patients suffering from pseudarthrosis. Long range clinical and radiological results are good.

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Le transfert osseux vascularisé tibial superieur

Résumé Les auteurs décrivent un transfert ostéo-periosté vascularisé, prélevé sur la face antéro-latérale de l'extremité supérieure du tibia. L'étude anatomique porte sur soixante membres inférieurs, conservés au froid. La vascularisation métaphysaire du transfert provient de la branche récurrente tibiale antérieure et de ses rameaux, la vascularisation diaphysaire étant issue des branches musculo-périostiées proximales. Le transfert vascularisé est prélevé avec la membrane interosseuse et peut être pediculé ou libre. L'expérience clinique porte sur deux cas de pseudarthroses multiopérées. Les résultats cliniques et radiologiques sont bons à long terme.

     

Vascular networks of the nucleus lentiformis

Summary The nucleus lentiformis vascular networks were studied in 30 brains by injecting the vascular system with gelatinous Indian ink. The nucleus lentiformis is divided into a medial part, the globus pallidus, and a lateral part, the putamen. These two parts differ completely from one another in their embryology, structure and functions. For these reasons, each part presents a specific vascular network. The putaminal network is dense and shows many similarities with the cerebral cortex vascular network; the pallidal one is simpler and less dense. These two vascular networks are located close to each other without overlapping. Their specificity may be in relation with the histological structure, with the morphogenetic evolution or with the functional activity of both nuclei to which they provide the vascularization.

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Les réseaux vascularies du noyau lenticulaire

Résumé L'étude des réseaux vasculaires du noyau lenticulaire (NL) est réalisée sur 30 cerveaux dont le système vasculaire a été injecté à l'encre de Chine gélosée. Le NL est constitué par deux parties, le putamen (néostriatum) et le globus pallidus (paléo-striatum), totalement différentes sur les plans morphologique, embryologique et fonctionnel. Chacune de ces parties possède un réseau vasculaire spécifique et caractéristique. Les deux réseaux se côtoient sans se chevaucher. Le réseau vasculaire putaminal est dense et présente de nombreuses similitudes avec le réseau vasculaire du cortex cérébral. Le réseau vasculaire pallidal se caractérise par sa simplicité et sa moindre densité. Leur spécificité peut être en rapport avec la structure histologique, l'évolution morphogénétique et avec l'activité fonctionnelle des noyaux dont ils assurent l'irrigation.

     

羟基磷灰石眼眶植入物纤维血管化进程的MRI研究

目的 采用MRI检查研究眼眶内植入羟基磷灰石(hydroxyapatite,HA)义眼台术后不同时期MRI表现.资料与方法 回顾性分析28例眼眶内植入HA义眼台的MR表现,术后1～14个月至少行1次MR平扫及增强检查.义眼台纤维血管生长程度评价用Gd-DTPA增强SE T1WI,按义眼台强化的程度和范围划分为Ⅰ～Ⅴ个等级.结果 28例眼眶内植入HA义眼台, 4例术后1个月,MR增强仅表现为义眼台边缘强化(Ⅰ级);5例术后2个月,其中4例表现为义眼台周围带状强化而中心未强化(Ⅱ级),1例表现为从义眼台周边至中心都有强化,但呈不均匀分布(Ⅲ级);5例术后3个月,均呈Ⅲ级表现;8例术后4个月病例中,有3例呈Ⅲ级表现,5例表现为整个义眼台较均匀明显强化或稍低(Ⅳ或Ⅴ级);6例术后5～14个月, 4例呈Ⅲ级表现,2例为Ⅳ级表现.结论 MRI增强扫描可直观、准确地评价义眼台血管化的程度和范围,为临床术后义眼台钻孔、置钉等提供有价值的信息.     

Shell-core bi-layered scaffolds for engineering of vascularized osteon-like structures

Bottom-up assembly of osteon-like structures into large tissue constructs represents a promising and practical strategy toward the formation of hierarchical cortical bone. Here, a unique two-step approach, i.e., the combination of electrospinning and twin screw extrusion (TSE) techniques was used to fabricate a microfilament/nanofiber shell–core scaffold that could precisely control the spatial distribution of different types of cells to form vascularized osteon-like structures. The scaffold contained a helical outer shell consisting of porous microfilament coils of polycaprolactone (PCL) and biphasic calcium phosphates (BCP) that wound around a hollow electrospun PCL nanofibrous tube (the core). The porous helical shell supported the formation of bone-like tissues, while the luminal surface of nanofibrous core enabled endothelialization to mimic the function of Haversian canal. Culture of mouse pre-osteoblasts (POBs, MC 3T3-E1) onto the coil shells revealed that coils with pitch sizes greater than 135 μm, in the presence of BCP, favored the proliferation and osteogenic differentiation of POBs. The luminal surface of PCL nanofibrous core supported the adhesion and spreading of mouse endothelial cells (ECs, MS-1) to form a continuous endothelial lining with the function similar to blood vessels. Taken together, the shell–core bi-layered scaffolds with porous, coil-like shell and nanofibrous tubular cores represent a new scaffolding technology base for the creation of osteon analogs.     

Vasculogenesis and angiogenesis in nonseminomatous testicular germ cell tumors

Testicular germ cell tumors (TGCTs) comprise the vast majority of all testicular malignancies and are the most common type of cancer among young male adults. The nonseminomatous variant of TGCTs is characterized by the presence of embryonic and extraembryonic tissues together with a population of pluripotent cancer stem cells, the so-called embryonal carcinoma. One of the main causes of the resistance of these tumors to therapy is their ability to invade adjacent tissues and metastasize into distant sites of the body. Both of these tumor processes are highly favored by the neovascularization of the malignant tissue. New vessels can be generated by means of angiogenesis or vasculogenesis, and both have been observed to occur during tumor vascularization. Nevertheless, the precise contribution of each process to the neoplastic vascular bed of TGCTs remains unknown. In addition, another process known as tumor-derived vasculogenesis, in which malignant cells give rise to endothelial cells, has also been reported to occur in a number of tumor types, including experimental TGCTs. The participation and cross talk of these 3 processes in tumor vascularization is of particular interest, given the embryonic origin of teratocarcinomas. Thus, in the present review, we discuss the importance of all 3 vascularization processes in the growth, invasion, and metastasis of testicular teratocarcinomas and summarize the current state of knowledge of the TGCT microenvironment and its relationship with vascularization. Finally, we discuss the importance of vascularization as a therapeutic target for this type of malignancy.     

三维能量超声诊断子宫内膜癌的临床价值

目的比较三维能量多普勒超声测量子宫内膜良、恶性病变患者的血流参数值;研究子宫内膜癌患者病理分期与血流参数的相关性。方法选择绝经后阴道流血患者55例,测定收缩期峰值流速(PSV)、搏动指数(PI)、阻力指数(RI)及血管形成指数(VI)。结果 1子宫内膜癌组的超声血管参数PSV、PI、RI值均显著低于子宫内膜良性病变组,VI值显著高于子宫内膜良性病变组(P<0.05);2子宫内膜癌组的VI值在Ⅰ期与Ⅱ期、Ⅱ期与Ⅲ期分别比较有显著差异(P<0.05);子宫内膜癌有、无淋巴结转移组间RI和VI值差异显著(P<0.05)。结论三维能量多普勒超声技术对子宫内膜良、恶性病变的诊断与鉴别诊断有重要临床价值,为临床术前评估子宫内膜癌的分期提供了一种相对准确的新手段。     

Silicate bioceramics enhanced vascularization and osteogenesis through stimulating interactions between endothelia cells and bone marrow stromal cells

The facts that biomaterials affect the behavior of single type of cells have been widely accepted. However, the effects of biomaterials on cell–cell interactions have rarely been reported. Bone tissue engineering involves osteoblastic cells (OCs), endothelial cells (ECs) and the interactions between OCs and ECs. It has been reported that silicate biomaterials can stimulate osteogenic differentiation of OCs and vascularization of ECs. However, the effects of silicate biomaterials on the interactions between ECs and OCs during vascularization and osteogenesis have not been reported, which are critical for bone tissue regeneration in vivo. Therefore, this study aimed to investigate the effects of calcium silicate (CS) bioceramics on interactions between human umbilical vein endothelial cells (HUVECs) and human bone marrow stromal cells (HBMSCs) and on stimulation of vascularization and osteogenesis in vivo through combining co-cultures with CS containing scaffolds. Specifically, the effects of CS on the angiogenic growth factor VEGF, osteogenic growth factor BMP-2 and the cross-talks between VEGF and BMP-2 in the co-culture system were elucidated. Results showed that CS stimulated co-cultured HBMSCs (co-HBMSCs) to express VEGF and the VEGF activated its receptor KDR on co-cultured HUVECs (co-HUVECs), which was also up-regulated by CS. Then, BMP-2 and nitric oxide expression from the co-HUVECs were stimulated by CS and the former stimulated osteogenic differentiation of co-HBMSCs while the latter stimulated vascularization of co-HVUECs. Finally, the poly(lactic-co-glycolic acid)/CS composite scaffolds with the co-cultured HBMSCs and HUVECs significantly enhanced vascularization and osteogenic differentiation in vitro and in vivo, which indicates that it is a promising way to enhance bone regeneration by combining scaffolds containing silicate bioceramics and co-cultures of ECs and OCs.     

rhPDGF对糖尿病鼠全层皮肤缺损创面微血管形成的影响和意义

目的:观察外源性重组人血小板源性生长因子(rhPDGF)对全层皮肤缺损的糖尿病鼠创面愈合过程中微血管形成的影响及促创面愈合的作用。方法:利用大鼠全层皮肤缺损创面愈合模型,将26只非糖尿病鼠52个创面分为3组:①A组为糖尿病大鼠创伤自然愈合组;②B组为接受rhPDGF治疗的糖尿病大鼠创伤愈合组;③C组为赋性剂组。于伤后3 d、7 d和14 d采取创面皮肤标本,用组织病理HE和血管Ⅷ因子抗体免疫组织化学染色技术检测创面肉芽再生与再血管化情况进行观察,同时观察创面的愈合情况。结果:全层皮肤缺损糖尿病鼠创面肉芽组织中微血管的形成数量少,采用赋性剂对照组与糖尿病鼠自然愈合组无显著差别。但外源性使用rhPDGF后,肉芽组织的形成量明显增多,内含的微小血管数量显著增加,愈合能力明显增强。结论:糖尿病大鼠微血管形成障碍可能是其创面愈合延迟的重要因素。而应用外源性的PDGF有助于微血管的形成,可以改善糖尿病鼠的创面愈合能力。