Ultraviolet irradiation of blood prevents transfusion-induced sensitization and marrow graft rejection in dogs

In a canine model using DLA-identical littermate pairs, we have shown that a regimen of three transfusions of donor blood given 24, 17, and 10 days before transplant uniformly leads to marrow graft rejection, presumably due to sensitization to minor (non-DLA) histocompatibility antigens. Untransfused dogs uniformly achieve sustained engraftment. In the present study, we investigated whether the exposure of blood to ultraviolet (UV) light (220-300 nm) prior to transfusion prevented sensitization of the recipient and allowed for successful marrow engraftment. Ten dogs were each given three pretransplant transfusions from the marrow donor. Each transfusion consisted of 50 mL of whole blood exposed in vitro to UV light for a total of 1.35 J/cm2. All ten dogs achieved engraftment. In contrast, all four dogs that had received sham-exposed transfusions rejected their grafts. In vitro studies revealed that although cell viability was not affected, leukocytes contained in UV-exposed blood were unable to function as stimulator cells in mixed leukocyte cultures or as accessory cells in mitogen- stimulated cultures. These data are consistent with the hypothesis that accessory cells are involved in transfusion-induced sensitization. We conclude that in vitro exposure of blood to UV light before transfusion prevents sensitization and allows for subsequent marrow engraftment.     

7-(4,7-二取代香豆素-3-乙酰氨基)头孢菌素的合成

本文根据构效关系,设计并合成了17个7-(4,7-二取代香豆素-3-乙酰氨基)头孢菌素衍生物。其缩合方法采用酰氯法、Vilsmeier试剂法及混合酐法。初步体外抑菌试验表明,化合物对革兰氏阳性菌和少数革兰氏阴性菌有较强的抗菌作用。进一步药理试验尚在进行。     

Theoretical and methodological considerations in the measurement of spasticity

Purpose: To discuss the measurement of spasticity in the clinical and research environments, make recommendations based on the SPASM reviews of biomechanical, neurophysiological and clinical methods of measuring spasticity and indicate future developments of measurement tools. Method: Using the results of the systematic reviews of the biomechanical, neurophysiological and clinical approaches, methods were evaluated across three dimensions: (1) validity, reliability and sensitivity to change; (2) practical quality such as ease of use and (3) qualities specific to the measurement of spasticity, for example ability to be applied to different muscle groups. Methods were considered in terms of applicability to research and clinical applications. Results: A hierarchy of measurement approaches was identified from highly controlled and more objective (but unrelated to function) to ecologically valid, but less objective and subject to contamination from other variables. The lack of a precise definition of spasticity may account for the problem of developing a valid, reliable and sensitive method of measurement. The reviews have identified that some tests measure spasticity per se, some phenomena associated with spasticity or consequential to it and others the effect of spasticity on activity and participation and independence. Conclusions: Methods appropriate for use in research, particularly into the mechanism of spasticity did not satisfy the needs of the clinician and the need for an objective but clinically applicable tool was identified. A clinical assessment may need to generate more than one 'value' and should include evaluation of other components of the upper motor neurone syndrome. There is therefore a need for standardized protocols for 'best practice' in application of spasticity measurement tools and scales.     

Biomaterial-associated infection of gentamicin-loaded PMMA beads in orthopaedic revision surgery

In two-stage orthopaedic revision surgery, high local levels of antibiotics are achieved after removal of an infected prosthesis through temporary implantation of gentamicin-loaded beads. However, despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow and potentially develop antibiotic resistance. Gentamicin-loaded beads were retrieved from 20 patients with prosthesis-related infections. Excised tissue samples were taken for routine culture, while beads were analysed in an extensive laboratory procedure. Extensive culture procedures indicated the presence of bacteria on gentamicin-loaded beads in 18 of the 20 patients involved, while 12 of these 18 patients were considered free of infection by routine culture. Nineteen of 28 bacterial strains isolated were gentamicin resistant and cultures from three patients yielded highly gentamicin-resistant sub-populations. It is concluded that routine culture of excised tissues in orthopaedic revision surgery is inadequate to ascertain full eradication of infection, especially as infecting, antibiotic-resistant bacteria preferentially adhere to and grow on gentamicin-loaded beads. Extensive examination of the bead surfaces is proposed as a more reliable indication that infection has been eradicated.     

不同孔径纳米羟基磷灰石人工骨修复兔桡骨缺损效果比较

目的:纳米级的羟基磷灰石材料与人体内组织成分更为相似,具有更佳的生物性能。评价不同孔径的多孔纳米羟基磷灰石人工骨的骨缺损修复能力,从而筛选出适合的孔径以达到骨传导功能与生物力学性能的良好统一。方法:实验于2005-10/2006-10在深圳市第二人民医院中心实验室完成。①实验材料:纳米羟基磷灰石人工骨以硝酸钙和磷酸二氢铵为原料,采用溶胶-絮凝法制备粉体,运用压力成型、木模成型和浸渍成型分别制得孔隙分布均匀的孔径分别为50～150μm、100～250μm和300～500μm的多孔纳米羟基磷灰石人工骨。②实验动物:雄性新西兰大白兔60只随机分为植入50～150μm孔径材料组、植入100～250μm孔径材料组、植入300～500μm孔径材料组、空白对照组,每组15只。实验过程中对动物处置符合动物伦理学要求。③实验方法:制备双侧桡骨骨缺损动物模型,然后用3种不同孔径的纳米羟基磷灰石人工骨材料植入骨缺损处进行修复,空白对照组不植入任何材料。④实验评估:术后4,8和12周分别行大体标本观察、X射线片观察、扫描电镜观察及生物力学测试,比较各组材料修复骨缺损的能力。结果:实验动物均进入结果分析。①X射线片检查结果:术后4周、8周、12周,植入100～250μm孔径材料组X射线评分高于植入50～150μm,300～500μm孔径材料组,差异有显著性意义(P<0.05)。②生物力学检测结果:术后4周、8周、12周,植入100～250μm孔径材料组生物力学强度高于植入50～150μm,300～500μm孔径材料组,差异有显著性意义(P<0.05)。③扫描电镜观察结果:植入100～250μm孔径材料组成骨效果明显优于植入50～150μm,300～500μm孔径材料组和空白对照组。结论:纳米羟基磷灰石人工骨具有良好的成骨能力,但其骨修复能力受孔径因素的影响,孔径100～250μm的纳米羟基磷灰石人工骨材料成骨能力较好。     

海马区星形胶质细胞培养上清液体外诱导人脂肪基质细胞向神经元样细胞的分化

目的:观察海马区星形胶质细胞培养上清液能否在体外诱导人脂肪基质细胞向神经元样细胞分化。方法:实验于2004-10/2005-06在华北煤炭医学院中心实验室完成。在无菌条件下从Wistar乳鼠分离出海马组织,从分离的海马组织中获得星形胶质细胞,并收集其培养上清液。取外科手术获得的人腹部皮下脂肪组织进行人脂肪基质细胞的原代培养。30例患者均知情同意。取第3代人脂肪基质细胞接种到培养孔中,预先放置无菌盖玻片的24孔培养板,制备细胞爬片或者接种到培养瓶中,细胞生长达50%～60%融合时,去除培养液,换为海马区星形胶质细胞培养上清诱导液进行诱导,对照组培养液为无血清培养基。倒置相差显微镜下连续观察细胞生长情况和形态变化,应用免疫细胞化学、鉴定神经前体细胞的特异性标志神经巢蛋白、神经细胞的特异性标志神经元特异性烯醇化酶、微管联合蛋白2和神经胶质细胞的特异性标志胶质纤维酸性蛋白的表达。结果:①诱导培养第3天,部分人脂肪基质细胞开始变形,从原先的细长梭状细胞变成神经元样细胞,可见细胞伸出突起,多为双极或多极细胞。②刚分离接种的人脂肪基质细胞镜下呈圆形,悬浮状态,接种后24h内贴壁,并开始伸展,多呈梭形。1周后细胞融合成单层,排列出现方向性,但有少量圆形及卵圆形细胞混杂生长。③第4,5代人脂肪基质细胞在诱导48h后形态即开始发生变化,扁平的胞体较预诱导后逐渐回缩,向外伸出突起,72h后扁平的胞浆向胞核收缩,突起继续延长,以后随时间进展,具有典型神经细胞形态特点的细胞数量逐渐增多,形成双极或多极细胞。④免疫细胞化学检测人脂肪基质细胞诱导5d后发现有(10.5±3.7)%神经巢蛋白、(38.4±5.2)%胶质纤维酸性蛋白、(15.7±2.3)%神经元特异性烯醇化酶表达,未见微管联合蛋白2的表达。结论:海马区星形胶质细胞培养上清液可以在体外诱导人脂肪基质细胞向神经元样细胞方向分化。     

Neurophysiological methods for the assessment of spasticity: The Hoffmann reflex, the tendon reflex, and the stretch reflex

Purpose: To review the literature concerning neurophysiological methods to assess spasticity with respect to mechanisms and methodology, and to describe the three most commonly used methods: the Hoffmann reflex (H-reflex), the Tendon reflex (T-reflex), and the Stretch Reflex (SR). Method: A systematic internet database search was performed to identify neurophysiological measurement methods of spasticity. A systematic exclusion procedure resulted in 185 included references, completed by additional informal search. For this paper, information about the H-, T- and stretch reflexes was extracted from these references. Results: Although the reflexes are basically monosynaptic, there are many supraspinal pathways which modulate the responses in terms of their amplitude and latency. As a consequence the methods are sensitive to a considerable number of experimental conditions and are characterized by a moderate reliability and sensitivity. Correlations with other (i.e. biomechanical, neurophysiological or clinical) spasticity assessment parameters are moderate to poor. Standardised and broadly accepted protocols are still largely lacking preventing an effective exchange of knowledge. Conclusions: The clinical and experimental use of the three methods is restricted due to moderate reliability and sensitivity. It is recommended to perform combined neurophysiological - biomechanical assessment of spasticity during active, functional movement.     

胶原性关节炎大鼠滑膜组织细胞因子基质金属蛋白酶3和组织金属蛋白酶抑制剂1表达的变化

目的:观察Ⅱ型胶原诱导的实验性关节炎动物模型组织细胞因子基质金属蛋白酶3和组织金属蛋白酶抑制剂1表达的变化,探讨基质金属蛋白酶3和组织金属蛋白酶抑制剂1在类风湿关节炎发病机制中的作用。方法:实验于2005-09/2006-11在白求恩国际和平医院中心实验室完成。①实验分组:健康雄性Wistar大鼠60只,体质量(100±20)g,随机选出50只以备造模,另外10只作为对照组。在造模成功的大鼠中再随机选出10只作为模型组。②实验方法:采用10mg牛Ⅱ型胶原与100mg弗氏不完全佐剂和60mg卡介苗充分研磨后,以每支每点0.1～0.2mL(1g/L)从大鼠背部尾根部多点皮下注射,于10d后按上述方法和剂量再次重复免疫和制作大鼠胶原性关节炎模型。③实验评估:初次免疫后7周,剥离膝关节滑膜,进行苏木精-伊红染色光镜下观察;切除另侧膝关节滑膜,免疫组织化学染色后,用Metamorph图像分析系统进行检测,计算每个视野基质金属蛋白酶3和组织金属蛋白酶抑制剂1的阳性面积比,以其作为阳性反应细胞密度。结果:纳入大鼠60只,20只进入结果分析。模型组大鼠关节组织中的基质金属蛋白酶3阳性密度为0.75±0.19,明显高于对照组,差异有显著性意义(P<0.01);组织金属蛋白酶抑制剂1的表达阳性密度为0.48±0.17,与对照组0.78±0.21比较明显降低,差异有显著性意义(P<0.01)。结论:细胞因子基质金属蛋白酶3和组织金属蛋白酶抑制剂1表达的变化与胶原性关节炎大鼠的发病相关。