同种异体移植免疫耐受的进展

探索组织器官移植后的排斥反应,提高移植物的存活率是移植免疫研究者致力攻克的堡垒。20世纪90年代以来,随着器官移植术的广泛开展,人们对移植排斥反应的认识不断加深,对移植免疫耐受提出了新的研究思路和方法。目前普遍认为,解决异体移植排斥反应的关键在于诱导受体对供体的细胞、组织或器官产生免疫耐受,即受体免疫系统对移植物抗原产生特异性免疫无反应性。本文将对近年来阻断特异性免疫应答、诱导免疫偏离、主动免疫诱导同种移植耐受及建立受者体内嵌合体诱导移植耐受等主要方面的进展综述。     

腰椎椎间融合器及其在椎间融合术中的生物力学研究进展

针对腰椎椎间融合术的生物力学研究背景和意义,回顾近年来椎间融合器及其在椎间融合术中的研究进展,并对其发展前景进行展望。主要归纳腰椎生物力学实验方法、椎间融合器和椎间融合术的最新进展,得出椎间融合术生物力学研究的主要方向为:有限元法的建模精细化、传统融合器的几何更优化、新型融合器的临床化和辅助固定方式的多样化。最后对椎间融合术生物力学的发展前景进行展望。通过对腰椎椎间融合术的生物力学研究进行回顾和展望,以期为腰椎疾患的临床手术治疗提供参考依据。     

No association between positive intraoperative allograft cultures and infection rates after reconstructive knee ligament surgery

Background

Several reports of severe infections associated with allograft tissue in knee reconstructive surgery have led many surgeons to consider routine intraoperative culture of allograft tissue before implantation. Thus, the purpose of this study was to determine the prevalence of positive soft tissue allograft cultures in reconstructive knee surgery, and evaluate its association with surgical site infection.

Significance of immune cell function monitoring in renal transplantation after Thymoglobulin induction therapy

Monitoring of immune status in transplant recipients is essential for predicting the risk of rejection or infection. In this study, we assessed the significance of immune cell function in 76 renal allograft recipients after Thymoglobulin induction and initiation of maintenance immunosuppression. Using the Immuknow (Cylex Inc) assay, the amount of adenosine triphosphate (ATP) produced by CD4+ cells in response to phytohemagglutinin (PHA) was measured in patients whole blood. In parallel, the frequency and phenotype of CD4+ T cells were determined by flow cytometry. The Immuknow assay yielded paradoxically high ATP values during the first 3 months post-transplantation, despite very low CD4+ T cell counts. High ATP values were caused by peripheral blood myeloid cells, did not predict rejection, and occurred primarily in transplant recipients who received darbepoietin (p = 0.017). CD4+ T cells displayed predominantly an activated/memory phenotype and comprised a subpopulation of CD25+FOXP3+ cells. Over the first 5 months post-transplantation, mean ATP activity gradually decreased, whereas CD4+ T cell counts slowly increased. Low ATP values were predictive of infection (p = 0.002). Thus Immuknow results need to be interpreted with caution in patients receiving Thymoglobulin induction therapy. Although low ATP levels identify patients at increased risk for infection, high ATP values fail to correlate with rejection and do not justify increased immunosuppression.     

腰椎行椎间孔入路椎间融合术固定的有限元分析

目的 利用有限元方法分析经单侧椎间孔入路腰椎间融合术治疗腰椎退行性病变的临床可行性。方法 基于正常人L3~5节段的CT扫描数据,利用Mimics、Pro/E、ANSYS软件分别建立L3~5正常生理状态有限元模型、L4/5左单侧椎弓根螺钉内固定加椎间融合器模型(单侧TLIF)、L4/5双侧椎弓根螺钉内固定加椎间融合器模型(双侧TLIF)。在L3上表面施加500 N的人体重力和10 N?m力矩,模拟人体直立、前屈、后伸、左侧弯和右旋5种生理活动,观察不同工况时椎体、椎间盘、螺钉及融合器上变形及应力分布情况,比较两种固定方法力学性能上的差异。结果 各种工况下单侧TLIF、双侧TLIF的L3~5节段变形量均较生理状态模型减少,单侧TLIF、双侧TLIF模型均在后伸运动时融合器的应力达到最大值,且单侧TLIF模型椎弓根螺钉上的应力峰值在各种工况中均明显高于双侧TLIF,后伸工况时应力峰值达到463.39 MPa。结论 单侧TLIF可作为腰椎退变性疾病的一种固定方法,但应力峰值均明显高于双侧TLIF模型,故系统稳定性差于双侧TLIF模型,提示患者在康复过程中应减少后伸运动,以免发生手术失效或螺钉断裂。     

Variations in ventral root axon morphology and locomotor behavior components across different inbred strains of mice

Locomotion is a complex behavior affected by many different brain- and spinal cord systems, as well as by variations in the peripheral nervous system. Recently, we found increased gene expression for EphA4, a gene intricately involved in motor neuron development, between high-active parental strain C57BL/6J and the low-active chromosome substitution strain 1 (CSS1). CSS1 mice carry chromosome 1 from A/J mice in a C57BL/6J genetic background, allowing localization of quantitative trait loci (QTL) on chromosome 1. To find out whether differences in motor neuron anatomy, possibly related to the changes in EphA4 expression, are involved in the motor activity differences observed in these strains, motor performance in various behavioral paradigms and anatomical differences in the ventral roots were investigated. To correlate the behavioral profiles to the spinal motor neuron morphology, not only CSS1 and its parental strains C57BL/6J (host) and A/J (donor) were examined, but also a set of other mouse inbred strains (AKR/J, 129×1/SvJ and DBA/2J). Significant differences were found between inbred strains on home cage motor activity levels, the beam balance test, grip test performance, and on alternating versus synchronous hind limb movement (hind limb hopping). Also, considerable differences were found in spinal motor neuron morphology, with A/J and CSS1 showing smaller, possibly less developed, motor neuron axons compared to all other inbred strains. For CSS1 and C57BL/6J, only genetically different for chromosome 1, a correlation was found between motor activity levels, synchronous hind limb movement and neuro-anatomical differences in spinal motor neurons. Inclusion of the other inbred strains, however, did not show this direct correlation. These data verifies the complex nature of the mammalian motor system that may be further dissected using genetic mapping populations derived from these inbred strains.     

Current outcomes of chronic active antibody mediated rejection – A large single center retrospective review using the updated BANFF 2013 criteria

BackgroundThe updated BANFF 2013 criteria has enabled a more standardized and complete serologic and histopathologic diagnosis of chronic active antibody mediated rejection (cAMR). Little data exists on the outcomes of cAMR since the initiation of this updated criteria.Methods123 consecutive patients with biopsy proven cAMR (BANFF 2013) between 2006 and 2012 were identified.ResultsPatients identified with cAMR were followed for a median of 9.5 (2.7–20.3) years after transplant and 4.3 (0–8.8) years after cAMR. Ninety-four (76%) recipients lost their grafts with a median survival of 1.9 years after diagnosis with cAMR. Mean C4d and allograft glomerulopathy scores were 2.6 ± 0.7 and 2.2 ± 0.8, respectively. 53.2% had class II DSA, 32.2% had both class I and II, and 14.5% had class I DSA only. Chronicity score >8 (HR 2.9, 95% CI 1–8.4, p = 0.05), DSA >2500 MFI (HR 2.8, 95% CI 1.1–6.8, p = 0.03), Scr >3 mg/dL (HR 3.2, 95% CI 1.6–6.3, p = 0.001) and UPC >1 g/g (HR 2.5, 95% CI 1.4–4.5, p = 0.003) were associated with a higher risk of graft loss.ConclusionscAMR was associated with poor graft survival after diagnosis. Improved therapies and earlier detection strategies are likely needed to improve outcomes of cAMR in kidney transplant recipients.     

PLIF技术在退变性腰椎滑脱并椎管狭窄症治疗中的应用

目的分析研究使用单枚椎间融合器(Cage)的腰椎后路椎体间融合技术(PLIF)在退变性腰椎滑脱并椎管狭窄症中的应用效果。方法选择2010年10月~2014年1月期间的退变性腰椎滑脱并椎管狭窄症患者42例,其中男22例,女20例;年龄41~76岁,平均61.9岁。所有患者均采用全椎板减压、椎间盘摘除、椎弓根钉系统复位内固定、后路椎体间融合术,融合均采用单枚椎间融合器(Cage)加自体骨粒植入。术后随访1~3年,平均1.7年。临床症状采用JOA评分、VAS评分和ODI评分来评价,影像学表现评价指标包括滑脱率、椎间隙高度、腰椎前凸角和植骨融合率。结果临床症状,术后6个月JOA评分、VAS评分和ODI评分均较术前有明显改善,且均具有统计学意义(0.05)。影像学表现,滑脱率、椎间隙高度和腰椎前凸角在术后6个月均获得明显的恢复,术前与术后的差异具有统计学意义(0.05)。随访42例病例均达骨性愈合,融合率为100%。结论经全椎板减压、椎间盘摘除、椎弓根钉系统复位内固定、后路椎体间融合术,可以达到彻底椎管减压,有效改善患者脊髓神经功能及生活质量。采用单枚Cage的PLIF技术能有效恢复和维持脊柱生理稳定性,可获得满意的影像学表现,融合率高,并发症风险低。     

颈前路零切迹与钢板椎间融合系统治疗单节段脊髓型颈椎病疗效比较

目的 比较颈前路零切迹椎间融合系统(Zero-P)和颈前路钢板椎间融合系统(PCB)治疗单节段脊髓型颈椎病的疗效。方法 采用前瞻性随机对照试验方法对2012年8月—2014年10月63例前路手术治疗的单节段脊髓型颈椎病患者进行研究。63例患者按随机数字表法分为Zero-P组(32例)和PCB组(31例)分别行Zero-P和PCB治疗。观察两组手术时间、术中失血、椎间高度、颈椎Cobb角、JOA评分、颈椎功能障碍指数(NDI)和远期并发症,远期并发症包括螺钉位置丢失、吞咽困难和骨性融合不佳。结果 Zero-P组中1例因随访丢失予以剔除,最终每组均有31例研究对象。两组患者性别、年龄、手术节段、椎间高度、颈椎Cobb角、JOA评分、NDI评分差异均无统计学意义(P值均>0.05)。病例随访时间均大于12个月,Zero-P系统组随访时间(15.52±1.93)个月;PCB组随访(16.10±2.33)个月,差异无统计学意义(t=1.069,P>0.05)。Zero-P组、PCB组手术时间分别为(63.45±10.87)、(85.97±12.04)min,术中出血量分别为(44.35±11.53)、(66.26±19.62)mL,差异均有统计学意义(t=7.730、5.358,P值均<0.01)。两组患者手术后及末次随访时的恢复椎间高度、颈椎Cobb角较术前明显改善,差异均有统计学意义(P值均＜0.05);两组间在手术后和末次随访时,恢复椎间高度、颈椎Cobb角水平差异均无统计意义(P值均>0.05),但在末次随访时PCB组在术后维持Cobb角方面更有优势(P＜0.05)。末次随访时两组JOA评分、NDI评分均较术前明显改善(P值均＜0.05),Zero-P组的NDI评分改善程度优于PCB组(P＜0.01)。至末次随访,两组病例均获骨性融合,其中PCB组出现2例螺钉位置丢失、3例吞咽困难,远期并发症方面Zero-P组优于PCB组(P＜0.05)。结论 Zero-P和PCB在治疗单节段脊髓型颈椎病均可获得较满意的治疗效果。Zero-P组具有手术较简易、颈椎功能保留多、螺钉位置丢失和吞咽困难的相关的远期并发症发生率较低的优点。而较之Zero-P,PCB能够更好地维持颈椎术后生理曲度。     

颈椎前路椎体间微创融合器的生物力学实验研究

目的评价植入镍钛记忆合金微创融合器(NiTi-TFC/C)的颈椎节段的稳定性及压缩力学性能。方法采集24只羊颈椎标本随机分为4组,每组6份,四组处理分别为:单取髓核组、自体髂骨植骨组、微创融合器组和钛制融合器组(InterFix)。所有标本进行前路减压,并对后3组进行椎间融合术。分别对各组标本进行生物力学测试并进行比较。结果微创融合器组与钛制融合器组在强度、刚度及扭转力学等方面无显著性差异(P>0.05)。而微创融合器组与自体髂骨植骨组具有显著性差异(P<0.05)。最大承载力为12050N。结论该微创融合器强度大、刚度高、抗扭转能力强,具有良好的抗压能力,为颈椎融合提供新型的融合装置。