全膝关节翻修术中采用金属垫片结合髓内延长杆重建骨缺损和关节稳定性的早期临床疗效

目的探讨全膝关节翻修术中采用金属垫片结合髓内延长杆重建非包容性骨缺损和关节稳定性的早期临床疗效。方法笔者自2013-12—2015-06对17例(17膝)AORIⅡ型非包容性骨缺损患者进行全膝关节翻修术,采用金属垫片重建骨缺损,恢复关节线水平,联合使用髓内延长杆加强翻修假体的稳定性。结果所有患者获得平均30.5(6~45)个月随访,无髌骨脱位、伸膝迟滞及膝关节前方疼痛等。术前膝关节KSS临床评分(24.5±7.9)分,功能评分(33.8±8.9)分,术后膝关节KSS临床评分(82.2±6.8)分,功能评分(85.5±8.1)分,术后KSS评分较术前明显提高,差异有统计学意义(t=41.328,P0.001;t=31.116,P0.001);膝关节活动度术前(63.9±9.9)°,术后(100.0±9.5)°,术后较术前明显提高,差异有统计学意义(t=8.512,P0.001);术后复查X线示假体位置及力线良好,假体周围未发现透亮带。结论全膝关节翻修术中采用金属垫块结合髓内延长柄能重建非包容性骨缺损及增加膝关节稳定性,恢复关节线水平,重建软组织平衡,简化手术操作,膝关节稳定性好,翻修成功率高,早期临床疗效满意。     

Concepts in regenerative medicine: Past,present, and future in articular cartilage treatment

Regenerative medicine is emerging with great interest and hope from patients, industry, academia, and medical professionals. Cartilage regeneration, restoration, or repair is one of the prime targets that remains largely unsolved, and many believe that regenerative medicine can possibly deliver solutions that can be widely used to address the current gap(s) in treatment. In the United States, Europe, Australia, and India the regulation of regenerative based treatments has become a big debate. Although the rules and regulations remain unclear, clinicians that are interested should carry-on with the best available guidelines to ensure safety and compliance during delivery in clinical practice to avoid regulatory infraction. Many have made significant investment of time, resources, and facilities in recent years to provide new regenerative treatment options and advance medical care for patients. Instead of reinventing the wheel, it would be more efficient to adopt currently accepted standards and nomenclature borrowed from transplantation science, and cord blood storage industries. The purposes of this article are to provide some historical background to the field of regenerative medicine as it applies to cartilage, and how this field has developed. This will be followed by a separate discussion on regulatory oversight and input and how it has influenced access to care. Furthermore, we discuss current clinical techniques and progress, and ways to deliver these treatments to patients safely, effectively, and in a cost sensitive manner, concluding with an overview of some of the promising regenerative techniques specific to cartilage.     

Humanized Mouse Models for Transplant Immunology

Our understanding of the molecular pathways that control immune responses, particularly immunomodulatory molecules that control the extent and duration of an immune response, have led to new approaches in the field of transplantation immunology to induce allograft survival. These molecular pathways are being defined precisely in murine models and translated into clinical practice; however, many of the newly available drugs are human‐specific reagents. Furthermore, many species‐specific differences exist between mouse and human immune systems. Recent advances in the development of humanized mice, namely, immunodeficient mice engrafted with functional human immune systems, have led to the availability of a small animal model for the study of human immune responses. Humanized mice represent an important preclinical model system for evaluation of new drugs and identification of the mechanisms underlying human allograft rejection without putting patients at risk. This review highlights recent advances in the development of humanized mice and their use as preclinical models for the study of human allograft responses.     

Chimeric Allografts Induced by Short‐Term Treatment With Stem Cell–Mobilizing Agents Result in Long‐Term Kidney Transplant Survival Without Immunosuppression: A Study in Rats

Transplant tolerance allowing the elimination of lifelong immunosuppression has been the goal of research for 60 years. The induction of mixed chimerism has shown promise and has been extended successfully to large animals and to the clinic; however, it remains cumbersome and requires heavy early immunosuppression. In this study, we reported that four injections of AMD3100, a CXCR4 antagonist, plus eight injections of low‐dose FK506 (0.05 mg/kg per day) in the first week after kidney transplantation extended survival, but death from renal failure occurred at 30–90 days. Repeating the same course of AMD3100 and FK506 at 1, 2 and 3 mo after transplant resulted in 92% allograft acceptance (n = 12) at 7 mo, normal kidney function and histology with no further treatment. Transplant acceptance was associated with the influx of host stem cells, resulting in a hybrid kidney and a modulated host immune response. Confirmation of these results could initiate a paradigm shift in posttransplant therapy.     

骨髓间充质干细胞治疗慢性肾脏病研究进展

慢性肾脏病(CKD)发病率逐年升高,有效治疗手段缺乏,患者在疾病终末期需接受肾替代治疗。目前,干细胞疗法作为研究热点已被运用于修复多种受损组织器官。研究表明骨髓间充质干细胞(BMSCs)对慢性肾脏病的治疗也起到了确切效果,具有一定治疗前景,且可与多种因素联合治疗显著提高疗效。本文就近年来骨髓间充质干细胞在治疗慢性肾脏病研究进展做一综述。     

建立不同类型干细胞并比较其分泌细胞因子的水平

目的比较不同类型干细胞分泌细胞因子的水平,探讨其潜在的临床意义。方法建立人类胚胎干细胞(hESCs)、脐带间充质干细胞(UMSCs)、羊膜间充质干细胞(AMSCs)株系;实时荧光定量聚合酶链反应(RT-qPCR)分析干细胞分泌细胞因子水平:(1)促炎因子,包括白细胞介素-6(IL-6)、白细胞介素-8(IL-8)和肿瘤坏死因子(TNF-α);(2)抑炎因子白细胞介素-10(IL-10);(3)生长因子,包括肝细胞生长因子(HGF)、脑源性神经营养因子(BDNF)、干细胞因子(SCF)和血管内皮生长因子(VEGF);(4)基质金属蛋白酶MMP-1及其抑制剂TIMP-1;(5)血管形成因子(Angiogenin),白血病抑制因子(LIF)以及骨形成蛋白(BMP4)。结果女性UMSCs分泌生长因子、血管生成因子、造血因子、抑炎因子等的能力显著强于hESCs、AMSCs(P0.05);女性hESCs、男性UMSCs分泌金属蛋白酶的水平显著高于其它干细胞(P0.05)。结论女性UMSCs可能具有更好的促进细胞生长、改善血供的能力;而女性hESCs、男性UMSCs则可能具有更强的降解结缔组织的能力。     

间充质干细胞在肿瘤靶向递药系统中的应用

间充质干细胞(mesenchymal stem cells,MSCs)是干细胞家族的重要成员,来源于发育早期的中胚层和外胚层,属于多能干细胞,由于其具有分化潜力大、增殖能力强、免疫原性低、肿瘤部位趋向性、取材方便、易于工业化制备等特征,有可能成为最具临床应用前景的多能干细胞。本文介绍间充质干细胞的基本特性以及其在肿瘤靶向递药系统中的研究进展、临床应用现状,为间充质干细胞在肿瘤靶向递药系统中的进一步研究提供依据。     

改良分次酶消化法分离培养兔肌腱干细胞及诱导分化鉴定

目的  采用改良分次酶消化法体外分离培养家兔肌腱干细胞,观察其生物学特性,并进行诱导分化及鉴定。方法  无菌条件下取出家兔髌腱组织,分别运用改良的分次酶消化法和酶消化后低密度稀释接种法进行分离、培养、传代,用倒置相差显微镜观察细胞形态特征并绘制两种方法的生长曲线,通过流式细胞鉴定仪检测肌腱干细胞表面抗原标志物的表达,取P3-P4代肌腱干细胞向成骨细胞、成软骨细胞诱导分化并鉴定。结果  改良的分次酶消化法较酶消化后低密度稀释接种法细胞增殖速度加快,形态均一,杂质细胞少。分离出的肌腱干细胞表面抗原标志CD90、CD44呈阳性,而CD34、CD14呈阴性,证实之前分离的细胞为肌腱干细胞。鉴定出肌腱干细胞具有向成骨细胞和成软骨细胞分化能力。结论  采用改良的分次酶消化法分离培养兔肌腱干细胞简单易行,肌腱干细胞生长及传代速度可观,活性良好,纯度较高。另外,肌腱干细胞的成功分离培养,也为肌腱相关疾病的研究开辟了一条新途径。

     

Human mesenchymal stem cells at the single-cell level: simultaneous seven-colour immunofluorescence

Extracellular, intracellular or surface proteins can be used as putative markers to characterize human mesenchymal stem cells (hMSC). However, these markers are also expressed by other cell types and primary cell pools reveal considerable heterogeneity. Therefore, the simultaneous detection of several markers on a single cell appears to be an attractive approach to identify hMSC. Here we demonstrate the specific distinction of human MSC from human osteoblasts via seven-colour fluorescence on the single cell level with simultaneous marker detection of CD44, CD105/endoglin, CD106/VCAM-1, collagen-IV, fibronectin, actin and DAPI nuclear staining. We performed spectral image acquisition using a Sagnac-type interferometer. Subsequent linear unmixing allowed for decomposition of each pixel in its spectral components. Our approach reveals a typical expression profile of the adherent singular cells, allowing the specific distinction between hMSC and osteoblasts on the single cell level.     

Differentiating embryonic stem-derived neural stem cells show a maturation-dependent pattern of voltage-gated sodium current expression and graded action potentials

A population of mouse embryonic stem (ES)-derived neural stem cells (named NS cells) that exhibits traits reminiscent of radial glia-like cell population and that can be homogeneously expanded in monolayer while remaining stable and highly neurogenic over multiple passages has been recently discovered. This novel population has provided a unique in vitro system in which to investigate physiological events occurring as stem cells lose multipotency and terminally differentiate. Here we analysed the timing, quality and quantity of the appearance of the excitability properties of differentiating NS cells which have been long-term expanded in vitro. To this end, we studied the biophysical properties of voltage-dependent Na(+) currents as an electrophysiological readout for neuronal maturation stages of differentiating NS cells toward the generation of fully functional neurons, since the expression of neuronal voltage-gated Na(+) channels is an essential hallmark of neuronal differentiation and crucial for signal transmission in the nervous system. Using the whole cell and single-channel cell-attached variations of the patch-clamp technique we found that the Na(+) currents in NS cells showed substantial electrophysiological changes during in vitro neuronal differentiation, consisting mainly in an increase of Na(+) current density and in a shift of the steady-state activation and inactivation curves toward more negative and more positive potentials respectively. The changes in the Na(+) channel system were closely related with the ability of differentiating NS cells to generate action potentials, and could therefore be exploited as an appropriate electrophysiological marker of ES-derived NS cells undergoing functional neuronal maturation.