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排序方式: 共有811条查询结果,搜索用时 15 毫秒
1.
《Vaccine》2019,37(35):5003-5008
BackgroundIt has been reported that persons primed with acellular (DTaP) pertussis vaccines have reduced duration of pertussis protection compared with those primed with whole-cell (DTwP) vaccines. However, due to the rapid transition to acellular vaccines, studies attempting directly to compare protection among DTaP-primed vs DTwP-primed individuals are subject to confounding by age and other limitations of ecological studies. Using validated assay results and stored sera from multiple Tdap studies, we evaluated two licensed Tdap vaccines among DTaP-primed adolescents to allow comparison with results obtained in the same laboratory from earlier studies involving DTwP-primed adolescents.MethodsParticipants 11–12 years of age who had received exactly 5 doses of DTaP vaccine prior to 7 years of age were randomly assigned in 2012 to receive one of two licensed Tdap vaccines. Serum specimens obtained pre- and post-vaccination were assayed for responses to the vaccines. Current results were then compared to results obtained in the same laboratory from prior randomized Tdap studies conducted among adolescents primed with DTwP or DTaP.ResultsBoth Tdap vaccines produced strong antibody responses to diphtheria and tetanus; responses to contained pertussis antigens were consistent with the differing levels of those antigens in each Tdap vaccine. However, postvaccination pertussis antibody responses were as much as 71% lower in these DTaP-primed adolescents compared with responses among DTwP-primed adolescents in a prior study of the same two Tdap vaccines. In contrast, results from the present study were similar to those seen in another study of Tdap among DTaP-primed adolescents.DiscussionTaken together, these results from randomized clinical trials provide direct evidence of reduced antibody responses to both licensed Tdap vaccines among adolescents primed with DTaP vaccine, compared with adolescents primed with DTwP vaccine.Clinical trial registry number: ClinicalTrials.gov, NCT01629589.  相似文献   
2.
目的 制备具有天然神经组织结构的支架,构建组织工程化面神经用于修复面神经损伤。方法 取家兔面神经,改良化学萃取法制备脱细胞神经基质,HE染色形态学观察去细胞及脱髓鞘情况,荧光分光光度计测定支架内细胞经Quant-iT PicoGreen工作液染色后的DNA含量。MTT法检测细胞在支架上的相对生长率从而检测支架的细胞毒性。结果 支架移植体呈圆柱形,弹性与正常神经基本一致,组织观察显示细胞结构未见残余完整细胞及细胞碎片残留,未见神经髓鞘及轴突结构,细胞外基质形成纵向排列结构,结构之间可见空隙。兔脱细胞面神经基质支架内残留的DNA含量较正常兔面神经明显下降(P<0.01)。神经基质供体无细胞毒性。结论 改良化学萃取法可有效去除面神经细胞,天然结构保存完好,细胞毒性低,可作为组织工程化面神经的支架。  相似文献   
3.
改良消蚀法制备脱细胞真皮基质微粒及其生物相容性评价   总被引:1,自引:1,他引:0  
目的:利用改良消蚀法制备一种新型脱细胞真皮基质(Acellular dermal matrix,ADM)微粒,并对其相容性加以评价,为组织工程微粒皮肤的制备奠定研究基础。方法:应用机械法切除猪真皮乳头层,结合消蚀法和冻融法除去网状真皮中的所有细胞制备成ADM,将ADM搅碎成颗粒状,对其做细胞毒性实验和皮下埋藏实验检验其相容性。结果:该方法制备的ADM微粒韧性好,细胞去除完全,胶原三维稍松散但结构完整,无基底膜和乳头层。细胞毒性实验显示其基本无毒性,成纤维细胞在ADM微粒上增殖良好,皮下埋藏试验未见明显排异反应,ADM微粒能诱导血管和成纤维细胞长入。结论:用改良消蚀法制备的ADM微粒抗原性低、相容性好,可以作为组织工程微粒皮肤的支架和填充材料。  相似文献   
4.
目的 探索在脱细胞猪主动脉瓣膜材料上种植人成纤维细胞的方法与效果;材料和方法 采用在脱细胞猪主动脉瓣膜材料上静态与动态种植人成纤维细胞,并对其结果进行比较研究。结果 静态种植不能在猪主动脉瓣叶的两侧形成完整的单层人成纤维细胞融合层;而经过动态种植,在一定条件下可以在猪主动脉瓣叶两侧形成完整的单层人成纤维细胞融合层;结论 动态种植较之静态种植易达到形成完整均匀的细胞种植效果。  相似文献   
5.
目的探讨开放性乳突病变切除术后加速乳突术腔上皮化及缩小乳突术腔的有效办法。方法63例行开放性乳突病变切除术的患者按照复查治疗方法分为两组,异种脱细胞真皮组36例,应用异种脱细胞真皮基质覆盖术腔,碘仿纱条组27例,以碘仿纱条填塞术腔。术后随访两组患者,对比观察术腔愈合情况和上皮化时间。结果异种脱细胞真皮组术腔上皮化时间为2~4周,平均2.2周;碘仿纱条组术腔上皮化时间为9~35周,平均13.7周,异种脱细胞真皮组的上皮化时间短于碘仿纱条组(P〈0.01)。结论异种脱细胞真皮基质可促进上皮组织再生,减少术后感染及肉芽发生,加速乳突腔上皮化,提高开放性乳突病变切除术的疗效。  相似文献   
6.
The current standard for composite tissue preservation is static cold storage (SCS) and is limited to 6 h until irreversible muscle damage occurs. Extracorporeal perfusion (ECP) is a promising technique for prolonged preservation, however, functional results have been scarcely researched. This article assessed neuromuscular function and compared results to histological alterations to predict muscle damage after ECP. Forelimbs of twelve Dutch landrace pigs were amputated and preserved by 4 h SCS at 4–6 °C (n = 6) or 18 h mid-thermic ECP with University of Wisconsin solution (n = 6). Limbs were replanted and observed for 12 h. Sham surgery was performed on contralateral forelimbs (n = 12). Histology analysis scored four subgroups representing different alterations (higher score equals more damage). Muscle contraction after median nerve stimulation was comparable between ECP, SCS, and sham limbs (P = 0.193). Histology scores were higher in ECP limbs compared to SCS limbs (4.8 vs. 1.5, P = 0.013). This was mainly based on more oedema in these limbs. In-vivo muscle contraction was well preserved after 18 h ECP compared to short SCS, although histology seemed inferior in this group. Histology, therefore, did not correlate to muscle function at 12 h after replantation. This leads to the question whether histology or neuromuscular function is the best predictor for transplant success.  相似文献   
7.
8.
目的了解脱细胞真皮和自体微粒皮复合移植术后局部瘢痕的性状。方法2004-2007年我单位完成20例脱细胞真皮和自体微粒皮复合移植手术修复肘关节周围皮肤三度烧伤,设为A组,同时随机选择20例大面积烧伤只采用自体微粒皮移植作为对照组,即B组,两组微粒皮比例均为1:10,观察两组相对应部位手术创面愈合时间,愈合时以及愈合后6个月肘关节区域瘢痕增生情况,超声波检测瘢痕厚度,色谱仪检查瘢痕颜色参数,应用温哥华评分(VSS)标准进行评估。结果创面愈合时A、B两组瘢痕厚度无显著性差异,但颜色参数和温哥华评分有显著差异。B组瘢痕厚度于伤后六个月显著高于A组。结论脱细胞真皮移植结合自体微粒皮移植有利于抑制深度烧伤创面局部瘢痕厚度,改善瘢痕性状。  相似文献   
9.
目的 探讨在羟基磷灰石义眼台植入术中,脱细胞异体真皮覆盖义眼台及其两个不同组织面的朝向对手术效果的影响.设计病例对照研究.研究对象北京同仁医眼科中心接受羟基磷灰石义眼台植入术,且术中采用脱细胞异体真皮覆盖义眼台的患者20例(20眼).方法 患者随机分为2组,第一组(基底朝外组)10例患者,在覆盖义眼台时,植入脱细胞异体...  相似文献   
10.
Acellular pertussis-containing combination vaccines are widely used in the developed world for the control of pertussis and have been successful in controlling disease in preschool-aged children. Combination vaccines formulated for use in adolescents and adults have been developed more recently and are increasingly being implemented for the control of pertussis in these age groups. One such family of products is PENTACEL? (Haemophilus influenzae type b conjugate vaccine reconstituted with component pertussis vaccine and diphtheria and tetanus toxoids adsorbed combined with inactivated poliomyelitis vaccine, DTaP-IPV-Hib), for use in young children, and ADACEL? (tetanus and diphtheria toxoids adsorbed combined with component pertussis vaccine, dTap) for use in adolescents and adults. These products have been demonstrated to be safe, immunogenic and effective for the control of pertussis and the other included diseases.  相似文献   
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