3D打印胶原/壳聚糖支架改善大鼠脊髓损伤后神经功能恢复

文题释义：壳聚糖：为一种天然多糖,是虾蟹等低等动物外壳的重要成分,具有一定的机械强度,并且具有良好的生物相容性和抗菌性,在生物工程领域具有较好的应用前景。 3D生物打印：是组织工程中最重要的技术之一。目前常用的三维生物打印方法包括喷墨打印、挤压生物打印和激光生物打印,选择好合适的材料后,在计算机指导下根据所选择的生物材料和细胞类型逐层准确地打印出所设计的结构。 背景：3D打印技术可以根据需求制备出满足脊髓植入形状、大小和表面形态要求的生物支架。 目的：观察3D打印胶原/壳聚糖支架对脊髓损伤大鼠神经功能恢复的影响。 方法：将胶原和壳聚糖按2∶1的质量比混合,采用冷冻干燥法制备普通胶原/壳聚糖支架,采用3D打印机制备3D打印胶原/壳聚糖支架,分别测量两种支架的孔隙率和弹性模量,电镜观察支架形态。将神经干细胞分别与3D打印胶原/壳聚糖支架、普通胶原/壳聚糖支架共培养,进行扫描电镜观察与CCK-8检测。将40只雌性SD大鼠(由中国人民解放军医学科学院军事科学院提供)随机分成4组：假手术组、脊髓损伤组、普通胶    原/壳聚糖支架组和3D打印胶原/壳聚糖支架组,后3组制作脊髓全横断损伤模型,普通胶原/壳聚糖支架组和3D打印胶原/壳聚糖支架组损伤处填充对应的支架材料,术后相应时间点进行后肢功能BBB评分、斜坡实验、神经电生理检测与磁共振平扫。实验方案经天津市神经创伤重点实验室伦理委员会批准。 结果与结论：①扫描电镜显示,3D打印胶原/壳聚糖支架具有互连的多孔结构,普通胶原/壳聚糖支架内部结构紊乱;②神经干细胞在3D打印胶原/壳聚糖支架表面生长良好,完全伸展,且3D打印胶原/壳聚糖支架表面神经干细胞的活性显著高于普通胶原/壳聚糖支架组(P < 0.05);③3D打印胶原/壳聚糖支架的孔隙率与弹性模量均高于普通胶原/壳聚糖支架组(P < 0.05);④3D打印胶原/壳聚糖支架组术后3-8周的BBB评分高于脊髓损伤组、普通胶原/壳聚糖支架组(P < 0.05),术后4,6,8周的斜坡实验角度大于脊髓损伤组、普通胶原/壳聚糖支架组(P < 0.05);⑤3D打印胶原/壳聚糖支架组术后8周的运动诱发电位振幅、体感诱发电位振幅大于脊髓损伤组与普通胶原/壳聚糖支架组(P < 0.05),运动诱发电位潜伏期、体感诱发电位潜伏期短于脊髓损伤组与普通胶原/壳聚糖支架组(P < 0.05);⑥磁共振平扫显示与脊髓损伤组及普通胶原/壳聚糖支架组比较,3D打印胶原/壳聚糖支架组损伤处具有较好的连续性与较多的神经纤维束通过;⑦结果表明,3D打印胶原/壳聚糖支架可促进脊髓损伤大鼠神经功能的修复。 ORCID: 0000-0001-5771-8222(史新宇) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

负载脑源性神经营养因子胶原/肝素硫酸支架促进颅脑创伤大鼠神经运动功能的恢复

文题释义：脑源性神经营养因子：是一种来源于脑组织的分子质量为12.3 kD的多肽或蛋白质,对神经系统损伤等具有一定的治疗潜能,能通过多种机制营养神经元,促进其再生和生长发育。胶原：广泛分布于细胞外基质中,能够为神经细胞的增殖、分化和代谢提供适宜的微环境,具有免疫原性低、生物降解性和生物相容性好等特点,缺点在于其力学性能较差。 硫酸肝素：是一种黏多糖,是神经细胞基底膜、细胞外基质的重要组成部分,能够调节生物活性,促进神经纤维的再生。 背景：研究表明胶原和硫酸肝素交联后可有效固定生长因子,显著改善脊髓损伤大鼠的神经运动功能恢复。 目的：观察负载脑源性生长因子胶原/硫酸肝素支架移植修复颅脑创伤的效果。方法：制作胶原支架、胶原/硫酸肝素支架与负载脑源性神经营养因子的胶原/硫酸肝素支架,检测胶原支架、胶原/硫酸肝素支架的孔隙率、吸水率、压缩模量和压缩应力;检测载脑源性生长因子胶原/硫酸肝素支架的体外缓释性能;检测胶原/硫酸肝素支架与负载脑源性神经营养因子的胶原/硫酸肝素支架的细胞毒性与细胞相容性。将48只SD大鼠随机分4组干预：对照组开骨窗后缝合,空腔组仅制作颅脑创伤空腔模型,支架组、生长因子支架组颅脑创伤后空腔处分别植入胶原/硫酸肝素支架、负载脑源性神经营养因子的胶原/硫酸肝素支架,术后分别进行改良神经功能缺损评分、水迷宫测试与脑损伤形态学观察。动物实验获得武警特色医学中心伦理委员会批准。结果与结论：①胶原/硫酸肝素支架的孔隙率、压缩模量和压缩应力高于胶原支架(P < 0.05),吸水率低于胶原支架(P < 0.05);②胶原/硫酸肝素支架无细胞毒性,负载脑源性神经营养因子后更加有利于脑微血管内皮细胞的增殖;脑微血管内皮细胞在负载脑源性神经营养因子支架微孔内生长良好,分布均匀;③形态学观察显示,两支架组损伤灶处可见大量新生神经细胞及神经纤维,其中以生长因子支架组的新生神经细胞数量及神经纤维密度更高;④生长因子支架组大鼠的逃逸潜伏期短于空腔组、支架组(P < 0.01,P < 0.05),象限停留时间和平台穿越次数高于支架组、空腔组(P < 0.01,P < 0.05);⑤生长因子支架组术后3-7周的改良神经功能缺损评分低于支架组、空腔组(P < 0.05,P < 0.01);⑥结果表明,负载脑源性神经营养因子胶原/硫酸肝素支架移植可以促进大鼠颅脑创伤后神经运动功能的恢复。ORCID: 0000-0003-2076-3606(张健) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

胶原/丝素蛋白支架联合神经干细胞治疗创伤性脊髓损伤北大核心

背景:随着交通事故、坠落伤、运动损伤等不断增多,创伤性脊髓损伤已成为危及脊髓健康的一个重要问题。目的:探讨胶原/丝素蛋白支架联合神经干细胞治疗创伤性脊髓损伤的疗效。方法:①分别提取胶原和丝素蛋白原料,将二者以质量比2∶4混合,采用真空冷冻干燥法制备胶原/丝素蛋白支架;将第3代GFP小鼠神经干细胞接种至胶原/丝素蛋白支架上,光学显微镜和扫描电镜下观察神经干细胞生长情况。②采用随机数字表达将40只成年SD大鼠分5组,正常组不进行任何处理,模型组建立T10段脊髓缺损模型,干细胞组脊髓缺损处注射神经干细胞,支架组脊髓缺损处植入胶原/丝素蛋白支架,联合组脊髓缺损处植入接种神经干细胞的胶原/丝素蛋白支架,每组8只。术后每周进行旷场实验BBB评分和斜坡实验,术后第8周行神经诱发电位检测、苏木精-伊红和免疫荧光染色,评价创伤性脊髓损伤大鼠恢复情况。结果与结论:①光学显微镜和扫描电镜下观察显示,胶原/丝素蛋白支架上有利于神经干细胞的黏附、伸展与分化。②旷场实验BBB评分和斜坡实验结果显示,脊髓损伤各组大鼠的运动功能随时间的延长均有不同程度的恢复,各治疗组大鼠的运动功能的恢复速度与程度均优于模型组,其中以联合组大鼠运动功能恢复最好。术后第8周,脊髓损伤后各治疗组大鼠的运动诱发电位和体感诱发电位的潜伏期、振幅检测结果均优于模型组(P<0.05),联合组检测结果优于干细胞组、支架组(P<0.05)。术后第8周苏木精-伊红染色显示,模型组大鼠脊髓损伤部位修复效果最差,联合组修复效果最好;免疫荧光染色显示,模型组大鼠脊髓损伤部位神经丝蛋白阳性细胞最少,各治疗组神经丝蛋白阳性细胞均多于模型组,其中以联合组最多。③胶原/丝素蛋白支架联合神经干细胞对创伤性脊髓损伤大鼠双下肢功能改善和脊髓组织修复具有一定效果。     

正常成人近段坐骨神经的弥散张量成像**

背景：弥散张量成像及神经纤维束示踪的出现为外周神经细微结构的显示及定量分析提供了新的方法。 目的：前瞻性分析健康成人大腿近段坐骨神经纤维束示踪、弥散张量成像的可行性及最佳成像参数。 方法：采用单次激发自旋回波-平面回波技术对28名健康志愿者双侧坐骨神经进行弥散张量成像及神经纤维束示踪,b值分别为1 200,1 400,1 600 s/mm2。 结果与结论：弥散张量成像及神经纤维束示踪成功者26名,成功率93%,神经纤维束示踪图上能清晰显示近段坐骨神经,与T1WI上解剖图像融合较好。两侧坐骨神经具有相同的弥散特征：随着b 值增加,信噪比逐渐减少,b值为1 200 s/mm2,信噪比值最大为142.72±32.25,神经纤维束长度最长,所占体素最大,但不同b值的弥散张量参数无差异(P > 0.05),且两侧坐骨神经弥散张量参数无差异。说明正常成人大腿近段坐骨神经的弥散张量成像及经纤维束示踪是可行的,可清晰显示坐骨神经走行及弥散特征;最佳b值为1 200 s/mm2。 关键词：弥散张量成像;坐骨神经;磁共振成像;神经纤维束示踪术;成年人 doi:10.3969/j.issn.1673-8225.2012.09.030     

胶原/丝素蛋白支架联合人脐带源间充质干细胞干预犬创伤性脑损伤

背景：迄今为止,创伤性脑损伤颠覆性的治疗手段非常有限,医学与工程的结合为中枢神经系统神经修复与再生带来了新的前景。目的：探讨可携带种子细胞、兼具安全性与多孔隙的胶原/丝素蛋白支架联合人脐带间充质干细胞对犬创伤性脑损伤的治疗作用。方法：(1)将第3代人脐带间充质干细胞接种至胶原/丝素蛋白支架上,倒置相差显微镜、扫描电镜、免疫荧光染色、苏木精-伊红染色观察人脐带间充质干细胞生长情况。(2)将24只比格犬利用随机数字法分为4组：创伤组只建立创伤性脑损伤模型不做其他处理,干细胞组造模后移植人脐带间充质干细胞,支架组造模后移植胶原/丝素蛋白支架,联合组造模后移植人脐带间充质干细胞与胶原/丝素蛋白支架,移植物均在损伤灶局部移植。术后1 d以及1,4,8,12,16,20,24周分别进行改良格拉斯哥昏迷评分评估,术后1,3,6个月进行运动诱发电位检测,术后6个月行核磁共振成像弥散张量成像和脑组织修复RNA原位杂交,评估创伤性脑损伤恢复情况。结果与结论：(1)人脐带间充质干细胞贴附胶原/丝素蛋白支架表面生长良好并伸出许多伪足;(2)术后1,4,8,12,16,20,24周,联合组改良格拉斯哥评分显著高...     

精确显微技术条件下构建脊髓损伤模型的脊髓离断状态

背景:弥散张量成像是一项常用于大脑临床研究中的技术,但很少用于脊髓损伤的诊断或预后。目的:采用显微技术建立大鼠脊髓损伤模型,用弥散张量成像技术评测脊髓离断情况,这为进一步的干预治疗提供良好的动物损伤模型。方法:健康SD大鼠12只在精确显微技术下制备脊髓损伤模型,6只假手术组作为对照。用核磁弥散张量成像技术观察实验组大鼠造模后脊髓离断情况,用运动诱发电位和感觉诱发电位检测大鼠神经电生理改变情况,利用斜坡实验和BBB评分评价大鼠造模后的神经功能的变化。结果与结论:实验组大鼠苏醒后双下肢全瘫、尾巴不能摆动、尿潴留;弥散张量成像图像显示其T10段脊髓完全离断;运动及感觉诱发电位波形较对照组均未引出;造模后1 d、造模后1,2,4周斜板试验角度均小于30°,BBB评分均少于10分,随时间延长,部分大鼠可见后肢刺激性反射,但无主动性功能活动,局部脊髓结构破坏严重。说明精确显微技术能成功构建大鼠脊髓损伤模型,并且在弥散张量成像图像上清晰可见T10段脊髓完全离断。     

弥散张量成像显示亚急性期脑梗死神经网络损伤及各运动参数分析

背景：脑卒中后神经网络与运动功能的相关性尚未明确。 目的：应用磁共振弥散张量成像研究亚急性期脑梗死后神经网络受损情况,并分析其与神经功能缺陷及运动功能障碍的相关性。 方法：将19例亚急性期脑梗死患者和20名正常成人分别进行弥散张量成像检查,分析比较以下参数：各向异性分数、表观扩散系数和各向异性分数指数、表观扩散系数指数。同时对患者进行神经功能缺损和运动功能的各项量表评估,检测10 m步行速度。将脑梗死患者弥散张量成像的各项参数与各项量表及10 m步行速度进行相关性分析。 结果与结论：脑梗死患者各向异性分数指数和双侧内囊后肢的各向异性分数值均小于正常对照,且患侧内囊后肢的各向异性分数值小于健侧内囊后肢的各向异性分数值(P < 0.05)。患侧内囊后肢的表观扩散系数值、表观扩散系数指数大于正常对照内囊后肢的表观扩散系数值和表观扩散系数指数(P < 0.05)。患侧内囊后肢的表观扩散系数值、表观扩散系数指数与下肢Fugl-Meyer评分呈负相关(P < 0.05)。提示弥散张量成像参数与下肢运动功能障碍密切相关。脑卒中后的局灶性病变造成神经网络缺损,是下肢运动功能障碍的主要原因。 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程全文链接：     

磁共振扩散张量成像在评价儿童脑内部分皮质脊髓束发育中的应用

目的 应用磁共振扩散成像技术探讨儿童皮质脊髓束年龄和性别差异及其变化规律。 方法 90例无中枢神经系统症状及体征且颅脑磁共振检查正常的儿童（年龄5d～18岁）。按年龄分为5组: 婴儿组（组1,≤1岁）,幼儿组（组2,＞1～3岁）,学龄前组（组3,＞3～6岁）,学龄组（组4,＞6～12岁）,青春发育期组（组5,＞12～18岁）。每个年龄组内再按性别分为男、女2组。各组儿童分别行头部扩散张量成像, 根据感兴趣法选取皮质脊髓束感兴趣区并重建,测量重建的皮质脊髓束的扩散张量参数并进行统计学分析。 结果 各年龄组的表观扩散系数(ADC)值、分数各向异性(FA)值、纤维示踪平均长度、体积以及示踪的纤维束数量不完全相同（P<0.01）;组间的两两比较间发现,1组与2组间ADC值、FA值及示踪纤维平均长度差异具有统计学意义;2组与3组间FA值差异具有统计学意义;3组与4组间ADC值、FA值、示踪纤维平均长度、纤维束数目及体积差异均具有统计学意义。ADC值与年龄间呈负相关,余参数与年龄间呈正相关。结论 儿童皮质脊髓束发育具有阶段性,且具有阶段性特征;磁共振扩散张量技术可用于观测儿童皮质脊髓束,评价其发育状况。     

MR弥散张量成像在脊柱脊髓疾病诊断中应用的研究进展

目的 探讨MR弥散张量成像(DTI)在脊髓疾病诊断中的应用进展。方法 在PubMed、Springer Link、中国知网数据库中,以“弥散张量成像、脊髓疾病、椎间盘”关键词,查阅2003年1月—2014年12月有关MR-DTI在脊髓疾病应用进展的相关文献,进行分析和总结。结果 MR-DTI体现脊髓病变早期组织空间组成和各组织成分之间水交换功能的改变,并能显示神经纤维束的走行方向,反映脊髓束功能的完整性。MR-DTI已逐渐应用于脊髓型颈椎病的早期诊断、脊髓损伤时期的判断和腰骶椎神经根病变的诊断以及腰椎间盘退变的早期诊断。DTI应用于脊髓疾病的诊断时,由于存在脊髓体积过小、扫描时间过长、运动伪影等不足,阻碍其在脊髓疾病诊断领域的发展。目前,随着并行成像技术、单次激发快速自旋回波序列等新技术的应用,这些问题正在逐步得到解决。结论DTI已在脊柱脊髓领域发挥出常规MR检查不可替代的作用。随着影像学的进步、新技术的应用及经验的丰富,DTI应用存在的阻碍必将得到解决,DTI在脊髓疾病领域的应用具有广阔的前景。     

磁共振扩散张量加权成像显示正常和病变肾脏的超微结构变化

背景:磁共振弥散张量可对每个体素水分子扩散的各向异性作出准确的检测。利用扩散张量成像评价肾脏及其病变内水分子运动特征,可反映出肾组织超微结构的变化,有利于病变的早期诊断。目的:验证磁共振扩散张量成像对正常肾脏和肾脏病变的临床诊断价值。方法:选择健康对照组12例和24例肾脏病变患者行肾脏扩散张量成像检查,肾脏病变患者中肾癌7例,肾囊肿7例,肾积水10例。观察肾脏皮质、髓质以及病灶表观扩散系数、分数各向异性的变化,并行髓质纤维束成像。结果与结论:正常肾脏中,肾皮质的表观扩散系数显著高于肾髓质(P=0.003),而肾髓质的分数各向异性显著高于肾皮质(P0.05)。肾癌表观扩散系数低于正常肾皮质、髓质(P0.05),瘤体内分数各向异性显著低于正常肾髓质(P0.05)。肾囊肿表观扩散系数显著高于正常肾皮质、髓质(P0.05),分数各向异性显著低于肾皮质和髓质(P0.05)。扩散张量纤维束示踪图可重建出肾髓质纤维束的形态,从而反映出肾小管和集合管的结构变化。提示扩散张量成像能显示正常肾脏和肾脏病变的超微结构变化,可用于肾脏病变的早期诊断和病情监控。     

Detection and characterization of new influenza B virus variants in 2002

One-hundred five influenza B-positive specimens obtained from southeast Asia in 2002 were categorized on the basis of DNA sequencing of HA1 gene as well as real-time PCR analysis of the NA gene. Phylogenetic analysis of the HA1 gene sequences showed that the majority of the viruses (96.2%) belonged to the B/Victoria/2/87 lineage, while a smaller percentage of the viruses (3.8%) belonged to the B/Yamagata/16/88 lineage. The B/Yamagata/16/88 viruses displayed significant antigenic drift in the deduced amino acid sequences of the HA1 protein, and the B/Victoria/2/87-like viruses consisted of B/Hong Kong/1351/02-like (72.3%) and B/Hong Kong/330/01-like (27.7%) viruses. The B/Hong Kong/1351/02-like viruses were reassortants with the HA gene belonging to the B/Victoria/2/87 lineage and the NA gene belonging to the B/Yamagata/16/88 lineage, whereas both the HA and NA genes of B/Hong Kong/330/01 virus belonged to the B/Victoria/2/87 lineage. In this study, however, all the B/Hong Kong/330/01-like isolates exhibited the B/Yamagata/16/88-like NA gene, which likely resulted from reassortment of B/Hong Kong/330/01 and B/Hong Kong/1351/02 viruses during coinfection. Additional molecular characterization of the six internal genes showed that the M, NS, PA, and PB2 genes of the new variants were B/Hong Kong/1351/02 in origin, whereas the NP and PA genes retained the B/Hong Kong/330/01 origin. Interestingly, these new variants all appeared late in the year 2002. These results support the notion that influenza B viruses continued to evolve through antigenic drift and shift.     

Radioimmunological study of the hemagglutinin of influenza viruses subtype H1N1

Radioimmunoassay were carried out with influenza A/Cambridge/46, A/FM/1/47, A/England/1/51, A/Denwer/1/57, and A/USSR/90/79 of the H1N1 subtype to determine the antigenic determinants of influenza A/USSR/90/77 virus hemagglutinin. The test system included 125I-labeled hemagglutinin of A/USSR/90/77 virus and homologous antiserum to this virus. The most marked antigenic similarity was found between A/USSR/90/77 and A/USSR/90/79 viruses. The A/Cambridge/46 and A/Denwer/1/57 viruses showed clear-cut differences in the antigenic determinants from the A/USSR/90/77 virus.     

Genetic and biological characterization of avian influenza H5N1 viruses isolated from wild birds and poultry in Western Siberia

Three viruses included in the study were isolated from dead birds (A/duck/Omsk/1822/2006, A/chicken/Reshoty/02/2006, and A/duck/Tuva/01/2006), whereas the virus A/common gull/Chany/P/2006 was isolated from an apparently healthy gull during outbreaks of highly pathogenic avian influenza in Russia in 2006. The intravenous pathogenicity index (IVPI) of viruses A/duck/Omsk/1822/2006, A/chicken/Reshoty/02/2006, and A/duck/Tuva/01/2006 ranged from 2.7 to 3.0, while the virus A/common gull/Chany/P/2006 had a markedly lower IVPI of 1.7. The virus A/common gull/Chany/P/2006 had a unique pattern of six amino acid substitutions in the regions of viral proteins crucial for virulence of H5N1 viruses. We hypothesize that these substitutions may affect the pathogenicity of A/common gull/Chany/P/2006.     

Molecular basis of functional voltage-gated K+ channel diversity in the mammalian myocardium

In the mammalian heart, Ca²⁺-independent, depolarization-activated potassium (K⁺) currents contribute importantly to shaping the waveforms of action potentials, and several distinct types of voltage-gated K⁺ currents that subserve this role have been characterized. In most cardiac cells, transient outward currents, I _to,f and/or I _to,s, and several components of delayed reactivation, including I _Kr, I _Ks, I _Kur and I _K,slow, are expressed. Nevertheless, there are species, as well as cell-type and regional, differences in the expression patterns of these currents, and these differences are manifested as variations in action potential waveforms. A large number of voltage-gated K⁺ channel pore-forming (α) and accessory (β, minK, MiRP) subunits have been cloned from or shown to be expressed in heart, and a variety of experimental approaches are being exploited in vitro and in vivo to define the relationship(s) between these subunits and functional voltage-gated cardiac K⁺ channels. Considerable progress has been made in defining these relationships recently, and it is now clear that distinct molecular entities underlie the various electrophysiologically distinct repolarizing K⁺ currents (i.e. I _to,f, I _to,s, I _Kr, I _Ks, I _Kur, I _K,slow, etc.) in myocyardial cells.     

三氧化二砷/锰锌铁氧体复合纳米粒体外治疗食管癌

背景：与传统的热疗方法相比,As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒可以同时发挥As₂O₃的细胞毒性作用和磁感应加热的联合定向治疗作用,效果优于单一治疗。 目的：制备As₂O₃/Mn_0.5Zn₀.₅Fe₂O₄复合纳米粒,观察其对食管癌Eca109细胞增殖的抑制作用。 方法：采用浸渍法制备As₂O₃/Mn₀.₅Zn_0.5Fe2O4复合纳米粒,含砷量0.012%,以透射电镜、能谱仪、原子分光光度仪对其进行表征。向两块培养板的食管癌Eca109细胞中分别加入DMEM培养液(阴性对照)、Mn_0.5Zn_0.5Fe₂O₄纳米材料、含As₂O₃终浓度5 μmol/L的As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒、游离As₂O₃(终浓度5 μmol/L),其中一块培养板进行磁流体热疗,另一块培养板正常培养。 结果与结论：As2O3/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒近似球形,As₂O₃成功浸渍在Mn_0.5Zn_0.5Fe₂O₄纳米材料表面,砷含量在0.012%-0.066%之间。当As₂O₃浓度为5 μmol/L时,As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒组细胞增殖率明显低于阴性对照组和Mn_0.5Zn_0.5Fe₂O₄纳米材料组(P < 0.05);而在磁流体热疗中,As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒组细胞增殖率明显低于游离As₂O₃组或Mn_0.5Zn_0.5Fe₂O₄组(P < 0.05);在凋亡率检测中,As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒联合磁流体热疗组细胞凋亡率明显高于Mn_0.5Zn_0.5Fe₂O₄纳米材料联合磁流体热疗组或游离As₂O₃组(P < 0.05)。表明As₂O₃/Mn_0.5Zn_0.5Fe₂O₄复合纳米粒联合磁流体热疗可显著抑制食管癌细胞增殖。     

Phylogenic analysis of Chinese Leishmania isolates based on small subunit ribosomal RNA (SSU rRNA) and 7 spliced leader RNA (7SL RNA)

The leishmaniases are zoonotic diseases caused by protozoan parasites of the genus Leishmania. Leishmaniases are still endemic in China, especially in the west and northwest froniter regions. To revalue the preliminary phylogenetic results of Chinese Leishmania isolates, we amplified partial fragment of small subunit ribosomal RNA (SSU rRNA) and 7 spliced leader RNA (7SL RNA), then tested the phylogenetic relationships among Chinese Leishmania isolates and their relatives by analyzing SSU rRNA gene sequences and 7SL RNA gene sequences. 19 SSU RNA sequences and 9 7SL RNA sequences were obtained in our study, then analyzed with 42 SSU RNA sequences and 32 7SL RNA sequences retrieved from Genbank, respectively. In the Bayesian analysis of the SSU RNA gene, the isolate MHOM/CN/93/GS7 and the isolate IPHL/CN/77/XJ771 are members of Leishmania donovani complex, while the isolate MHOM/CN/84/JS1 clustered with Leishmania tropica. The other 11 Chinese Leishmania isolates (MHOM/CN/90/WC, MCAN/CN/90/SC11, MHOM/CN/80/XJ801, MHOM/CN/85/GS4, MHOM/CN/84/SD1, MCAN/CN/86/SC7, MHOM/CN/54/#3, MHOM/CN/83/GS2, MHOM/CN/90/SC10H2, MHOM/CN/89/GS6 and MHOM/CN/ 89/GS5) form an unclassified group, defined as Leishmania sp., and the most relative species to this group is L. tarentolae. In the Bayesian analysis of the 7SL RNA gene, 9 Chinese Leishmania isolates also formed an unclassified group with L. tarentolae, including canine isolate 10, MHOM/CN/85/GS4, MHOM/CN/84/SD1, MCAN/CN/86/SC7, MHOM/CN/54/#3, MHOM/ CN/83/GS2, MHOM/CN/90/SC10H2, MHOM/CN/89/GS6 and MHOM/CN/89/GS5. We concluded that: (1) Chinese Leishmania isolates are non-monophyly group; (2) an unclassified group may exist in China, and the most relative species to this group is L. tarentolae; (3) MHOM/CN/84/JS1, which was previously assigned as L. donovani, was most genetically related to L. tropica strain MHOM/SU/74/K27.     

Book Reviews

Immunological Tolerance, (British Medical Bulletin, Volume 32, No. 2, May, 1976), D. W. Dresser, ed.

Immune Reactivity of Lymphocytes (Development, Expression and Control), M. Feldman, A. Globerson, ed.

Immunogenetics and Immunodeficiency, B. Benacerraf, ed.

Manual of Clinical Immunology, N.R. Rose, H. Friedman, eds.

Immunobiology of the Tumor-Host Relationship, R.T. Smith, M. Landy, eds.

The White Cell, M. L. Cline

Transfer Factor, Basic Properties and Clinical Applications, S. Asbher, A. Gotlieb, Ch. H. Kirkpatrick eds.

The Immune System of Secretions, T.B. Tomasi, Jr.

Surgical Immunology, A.M. Minister, ed.

Comparative Immunology, E.L. Cooper

The Immune System A Course on the Molecular and Cellular Basis of Immunity, M.J. Hobart, I. McConnell, eds.

Immunological Response of the Female Reproductive Tract, B. Cinader, A. de Week

Patch Testing, S. Fregert, H. J. Bandmann, eds.

The Role of Immunological Factors in Infectious, Allergic, and Autoimmune Processes, R. F. Beers, Jr., E. G. Bassett, Eds.     

Radioimmunological analysis of the neuraminidase of influenza virus subtype N2

Competitive radioimmunoassay in the homologous system using 125I-labeled neuraminidase (NA) of A/Japan/305/57 virus and antibodies to it showed that influenza viruses NA of subtypes H2N2 (A/Singapore/1/57 and A/Tokyo/3/67) and H3N2 (A/Aichi/2/68, A/England/42/72, A/Port Chalmers/1/73, and A/Texas/1/77) had undergone clear antigenic change despite the presence of Japan strain NA determinant. The use of a heterologous system (125I-NA of the Japan strain--antibodies to NA of England/42/72 strain) for the study of the intratype determinant showed the presence of a common determinant in all the strains under study, this determinant being represented dissimilarly, however. Neuraminidase of the Texas strain has a determinant differing from the intratype one, common for the Japan and England viruses.     

ASRI2005-88 Comparable levels of CD4+CD25+ CTLA4+ Treg cells in peripheral blood of pre-eclampsia and normal pregnant patients

The acceptance of the semiallogeneic fetus within the maternal environment requires tolerance mechanisms not fully characterized yet. Normal pregnancy is known to be associated with a Th2 profile. Furthermore, T-regulatory cells were proposed to regulate the Th2/Th1 balance at early stages of pregnancy. Treg may avoid the shift to a Th1 profile preventing miscarriage. Accordingly, spontaneous abortion is characterized by a Th1 dominance and diminished levels of Tregulatory cells (Treg). The major aim of the present work was to investigate if pre-eclampsia, a late immunological complication of pregnancy, is characterized by similar hallmarks. Therefore, we measured the surface antigens CD4, CD25, CD8, CTLA4 (as well as the secretion of IL-10) in peripheral blood from patients suffering from pre-eclampsia (n = 8) and age-matched patients undergoing normal pregnancies (n = 9) by 4-colour flow-cytometry. We were not able to find any significant differences in the levels of CD4⁺, CD25⁺, CD8⁺, CTLA4, CD4⁺/CD25⁺, CD4⁺/CD25^bright, CD4⁺/CTLA4, CD25⁺/CTLA4, CD4⁺/CD25⁺/CTLA4, CD8⁺/CD25⁺, CD8⁺/CTLA4 or CD8⁺/CD25⁺/CTLA4 cell subsets. Our data suggest that Treg may not participate in the onset of pre-eclampsia and suggest other regulatory mechanisms during late pregnancy.