胎儿房室结微血管构筑的扫描电镜观察

用血管铸型结合扫描电镜方法观察了7例胎儿房室结微血管构筑.微动脉反复分支呈树状,行走方式呈波浪形或螺旋形.毛细血管网可分为内外两层:外层纵行为主,以"H"或"Y"形吻合;内层弯曲行走为主,并互相交错吻合.以房室结动脉主干为界,其下方毛细血管密度较大,其上方及前方较小.房室结的上方、前下方和后下方均有微动脉连接毛细血管网.整个结的毛细血管大致可分为结后部上方、下方及前部三个区域.靠毛细血管网外层处可见管径较粗、呈袋状的微静脉.     

Motion artifact reduction with three-point ghost phase cancellation.

A novel method for "ghost" artifact suppression is introduced. It suppresses ghosts induced by motion in any direction, as well as other types of quasi-periodic signal modulation. Because it requires neither special hardware nor intensive data processing, it can be easily implemented on conventional magnetic resonance (MR) imagers. The method is based on the concept of decomposition of a ghosted complex image into a ghost mask and ideal image. A set of deliberately designed acquisitions are used to generate a set of ghosted complex images in which the ghost components are related in a simple manner. With use of equations describing image decomposition and ghost correlation, the ideal image can be calculated pixel by pixel. The ideal image obtained (representing the time-averaged spin-density distribution) is shown to be a truer representation of physical reality than the ghost-free image obtained with ordered phase encoding. In this technique, both interview and intraview effects are taken into account. The technique is also useful in simultaneously suppressing ghosts from multifrequency signal modulations such as respiratory and cardiac motions. The method was successfully tested with three time-interleaved, phase-encoding-order-shifted acquisitions. Experimental results have shown that it is a simple but effective technique.     

经迷路进路听神经瘤术后脑脊液漏的预防及处理

目的　探讨经迷路进路听神经瘤切除术后脑脊液漏发生的影响因素及处理方法。方法1999年以来采用迷路进路或扩大迷路进路听神经瘤切除术 85例 ,前 4 1例采用传统关闭术腔技术 ,后4 4例对关闭技术进行改良 ,分析其脑脊液漏的发生率。发生脑脊液漏者行保守或手术治疗。结果传统关闭技术组中脑脊液漏的发生率为 19 5 % ( 8 4 1) ,改良关闭技术组中脑脊液漏的发生率为 2 3%( 1 4 4 ) ,两组差异有显著性意义 (P =0 0 13)。传统关闭技术组中脑脊液漏多数发生在大型听神经瘤中 ,其发生率随肿瘤增大有上升的趋势。 9例脑脊液漏的患者中 ,3例经保守治疗 ;6例经手术修补成功 ,其中 5例 1次修补成功。结论　改良关闭术腔技术可显著降低经迷路进路听神经瘤切除术后脑脊液漏的发生率 ,手术修补为终止脑脊液漏的有效措施     

抗膀胱癌免疫毒素BDI-1-PEA特异杀伤肿瘤细胞的研究

新近利用抗原处理细胞(APC细胞)处理制备瘤疫效疗较为肯定,认为天然免疫细胞DC细胞瘤疫更有其应用价值.红细胞也是天然免疫细胞.能否用红细胞处理补体调理过的肿瘤细胞制备瘤苗是值得探讨的.有的学者认为红细胞是T细胞活性的调节器,我们的实验有可能为此提供的依据[Arosa FA, Currpharm Des, 2004, 10(27): 191].     

PET在肺癌诊断和分期中的应用

本文介绍正电子发射断层显像(PET)在肺癌诊断和分期中的应用概况，肯定了其临床应用价值。并简要叙述我国PET目前现状及今后展望。PET系大型医疗设备，我国未纳入医疗保险，其发展要根据社会经济发展和病人承受能力，合理布局，有限量地增加。作者指出，加强核医学科人员培训与临床各科医师(包括放射科，肿瘤科，胸外科，放射治疗等)的合作是提高PET临床应用和研究水平的关键因素。     

错畸形牙弓形态的模拟及比较

目的 :比较不同类型错牙合畸形的牙弓形态。方法 :采用三维测量仪精密测量正常牙合及 4组不同类型错牙合(ClassⅠ双颌前突、ClassⅡ1、ClassⅡ2 、ClassⅢ )的原始模型 ,圆锥曲线模拟其牙弓形态。结果 :不同类型错牙合牙弓形态的差异有显著性 ,甚至某些分组的上下颌之间牙弓形态的差异也有显著性。结论 :临床上弯制弓丝时采用单一的标准牙弓形态是不完全科学的 ,应考虑错牙合的不同类型及其矫治前不同的牙弓形态以防止畸形复发。     

N-甲基-D-天门冬氨酸受体及其调控的钙内流在大鼠感染性脑损伤中的变化

为探讨Ｎ－甲基－Ｄ－天门冬氨酸（ＮＭＤＡ）受体及其调控的钙内流在感染性脑损伤发病机制中的作用，采用Ｆｕｒａ－２／Ａｍ荧光法检测大鼠大脑皮质突触体内游离钙浓度（［Ｃａ＋＋］ｉ）。结果表明，注射百日咳杆菌组的［Ｃａ＋＋］ｉ较对照组显著增加（Ｐ均＜０．０１），并与注菌时间呈正相关关系（４小时ｖｓ０．５小时和２４小时ｖｓ４小时，Ｐ＜０．０５和＜０．０１）。ＮＭＤＡ受体的非竞争性拮抗剂ＭＫ－８０１预处理组（ＭＢＰ）的［Ｃａ＋＋］ｉ、脑含水量和伊文思蓝含量均较注菌组显著减少（Ｆ值分别为７２．２５、１６．８９、１４．３６，Ｐ＜０．０１和＜０．０５），并以２４小时［Ｃａ＋＋］ｉ减少最为明显（Ｐ＜０．０１）。提示ＮＭＤＡ受体调控的神经元内钙超载在感染性脑损伤、尤其在迟发性脑损伤的发病机制中起着重要作用。     

针灸疗法对脑卒中的免疫调节作用

无论是非特异性的炎症反应或是抗原特异性T细胞介导的细胞免疫反应,以及体液免疫的变化,均在脑卒中的发生发展中起着不可忽视的作用。针灸通过干预免疫反应过程的某些环节,降低免疫反应给机体造成的损害,成为治疗中风病的有效方法之一。本文探讨了针灸治疗脑卒中的免疫调节作用及机理,为临床采用针灸疗法调节中风患者的免疫紊乱提供了理论依据。     

Intimal hyperplasia after long-term venous catheterization

OBJECTIVE: Intimal hyperplasia is a well-known consequence of arterial injury and arterialization in vein grafts. However, the subacute and chronic vein wall changes which occur after catheterization have not been well studied. In this animal study, intimal hyperplasia in the vein wall after catheterization was examined. METHODS: A silicon catheter was placed in the anterior caval vein of 54 rats. After in situ fixation at scheduled intervals (1 day to 6 months), the pathologic changes in the vein wall were studied on semi-serial histology sections by means of light microscopy. RESULTS: Three forms of intimal hyperplasia could be observed: plaque-like, papillary-like and incorporation of the mural part of the sleeve into the underlying vein wall. Although the appearance of each was different, their composition was identical. All were mainly composed of alpha-actin-positive cells and collagen localized above the internal elastin layer, and covered by endothelium if facing the lumen. The plaque-like and papillary-like forms were mainly localized in the anterior vena cava, while sleeve incorporation mainly occurred in the jugular vein. Plaque-like and papillary-like intimal hyperplasia could be seen together on the same slide, but these two forms were never seen together with sleeve incorporation. CONCLUSION: Intimal hyperplasia occurs after venous catheterization and is probably caused by chronic injury to the vein wall due to knocking and rubbing movements of the catheter against the wall.