Contemporary bone loss options: Rebuild,reinforce, and augment

Bone loss is commonly encountered during revision total knee arthroplasty (TKA). Small defects can be adequately managed with cement filling (with or without screws), modular prosthetic augments, and morselized allograft. For larger defects, cancellous impaction grafting and structural allografts have traditionally been utilized. More recently, highly porous tantalum cones and titanium sleeves have been designed to achieve axial and rotational stability in the metaphysis and subsequent biologic fixation. Sleeves are linked to one type of prosthesis, whereas cones are unlinked and can be used with any implant design. Multiple studies have demonstrated excellent survivorship and radiographic osseointegration at mid-term follow-up. This article provides a review of contemporary methods of bone loss management with a focus on highly porous metals and an emphasis on the authors’ preferred method for managing the severe bone loss in revision TKA.     

Polyethylene in knee arthroplasty: A review

Polyethylene (PE) has been used extensively in knee arthroplasty since the mid 20th century. Progress in material manufacturing and processing has led to newer polyethylenes over last few decades with different material properties. It has been established that PE wear in knee arthroplasty causes particle induced osteolysis which is the main reason for late failure and requires revision surgery. Although there are various causes of wear, the properties of PE have long been a matter of investigation as a contributory factor. The advent of newer highly cross linked PE has been shown to improve wear rates in hip arthroplasty but the benefits have not been shown to be of the same degree in knee arthroplasty. The laboratory and clinical studies so far are limited and slightly conflicting in their conclusions. The risks of using highly cross linked PE in knee arthroplasty include tibial post fracture, disruption of locking mechanism, liner fracture which can lead to increased wear and osteolysis. The current evidence suggests that highly cross linked polyethylenes should be used with caution and only considered in younger active patients. The results of a recently completed randomized trial to compare the conventional with high molecular weight PE in knee arthroplasty are awaited.     

Adsorption of Human Recombinant Erythropoietin on Dialysis Membranes In Vitro

Abstract: The adsorptive characteristics of 5 dialysis membranes for recombinant human erythropoietin (EPO) were studied in vitro in a closed circuit system. For 120 min, EPO added with bovine serum was significantly adsorbed by polymethylmetacrylate (PMMA) and polyacry–lonitrile (PAN) membranes but not by Cuprophan, ethylene vinyl alcohol (EVAL), or polysulfone (PS) membranes. In addition the EPO adsorptive rate, as well as that of β₂–microglobulin (β₂–MG), was greater with a PMMA membrane than with a PAN membrane. EPO was not detected in the ultrafiltrate at 15 min with 5 membranes. These results indicate that EPO was eliminated by membrane adsorption only with some dialysis membranes.     

起搏器高度依赖性患者起搏器置换方法与疗效探讨

目的 :探讨起搏器高度依赖性患者起搏器置换方法与疗效。　方法 :对 8例起搏器高度依赖性患者 ,在起搏器与电极的接口松解前 ,应用在体起搏器间断接触法 ,使自身逸搏心律得已恢复 ,然后再行松解接口以及必要的起搏参数测试。　结果 :起搏器离体次数为 3～ 7(5± 2 )次 ,最长逸搏间期为 3.38～ 6 .2 0 (4.5 1± 1.11)s,自身逸搏心率为 30～ 4 3(38± 5 )次 /min ,均顺利完成起搏器置换。　结论 :在体起搏器间断接触法切实可行 ,能够明显提高起搏器高度依赖性患者起搏器置换的安全性     

腹腔镜高选择性迷走神经切断术联合Nissen胃底折叠术:效果如何?——腹腔镜Nissen迷走神经切断术治疗胃食管返流

背景：Nissen胃底折叠术（Nissen fundoplication，NF）已不是治疗胃食管返流性疾病（gastroesophageal reflux disease，GERD）的唯一、有效的方法。对于能降低胃酸的手术方式来讲，如高选择性迷走神经切断术（highly selective vagotomy，HSV），也不仅仅是一种辅助治疗方法。对高选择性迷走神经切断术联合Nissen胃底折叠术（Nissen fundoplication with highly selective vagotomy，NFHSV）治疗GERD的作用目前尚无完整的评价。方法：2003年6月～2005年6月8例女性病人接受NFHSV，8例均有6个月GERD病史，经药物治疗症状无缓解，有餐前痛、消化性溃疡或严重的胃炎。平均随访时间12个月，术前、术后进行烧心严重程度评分测定（heart burn severity score，HSS）。结果：平均手术时间110min，无手术并发症。1例术后须用质子泵抑制剂，术后经戒烟5个月后停药。8例术后症状和烧心严重程度评分测定有明显改善。结论：NFHSV是有效的联合手术方式，尚需要进一步的研究证实这一联合术式的完全有效性和安全性。     

高敏受者肾移植术前行血浆置换的临床探讨

目的 :探讨高敏受者肾移植术前行血浆置换 (PE)的效果。方法 :12例高敏受者在肾移植术前进行PE治疗 ,37例高敏受者未行PE治疗 ,观察两组肾移植病人排斥反应发生率的差异。结果 :PE组置换前PRA值71.0 %± 19.1% ,置换后 34.3%± 17.9% ,两者有显著性差异 (P <0 .0 1)。术后发生超排 2例 ,急性排斥 2例 ;未行PE组发生超排 2例 ,急性排斥 8例 ,两组间超排和急性排斥的发生率均无显著性差异。结论 :PE对预防超排和降低急性排斥的发生率均无明显作用。PE治疗的主要适应症为PRA大于 80 %的受者 ,能快速降低PRA值 ,有助于HLA抗体特异性分析和HLA配型。     

中国ESI高被引科学家和ESI学术期刊的学科分布探析与比较

【目的】 结合国家对学术期刊发展的指导政策,为中国英文学术期刊发展路径提供思路、数据支撑和理论指导。【方法】 以中国ESI高被引科学家和ESI期刊在ESI 22个学科的分布为研究对象,对两者分别在世界ESI高被引科学家和世界ESI高被引期刊中的发展脉络进行分析。【结果】 两类研究对象的发展现状不均衡,中国ESI期刊行业布局尚未对中国ESI高被引学者的跨学科发展趋势做出响应。【结论】 在中国基础学科的高被引科学家不断涌现的背景下,除了大力发展基础学科的高质量期刊以外,扶持交叉领域期刊、综合性学术期刊以及文科和应用型学科期刊的发展对促进中国ESI期刊学科分布均衡发展有重要意义;中国ESI期刊应将扶植国内科研工作者作为首要使命。     

Concentrating stroke care provision in the Czech Republic: The establishment of Stroke Centres in 2011 has led to improved outcomes

This article describes policy processes that have led to the re-organisation of stroke care in the Czech Republic since 2011, which has been part of a broader process of care concentration in several medical fields. Currently, stroke care is provided by 13 Comprehensive and 32 Primary Stroke Centres. The paper explains factors that supported the reform implementation, reviews implications, and discusses future challenges.Mandatory reporting of quality indicators, the introduction of a benchmarking system, integration with pre-hospital emergency care, and the introduction of countrywide patient triage have supported more timely treatment for stroke patients and better quality of care. Data from the Stroke Care Quality Indicators of the Czech Stroke Society show positive trends in many areas: the number of patients treated with intravenous thrombolysis quadrupled in eight years, with 26.4 % of all acute stroke patients receiving thrombolysis in 2018. Czech Republic now ranks third in Europe in the number of thrombolysis per population and second in the number of mechanical thrombectomies per population. The Czech experience provides an example of positive outcomes of concentrated stroke care, while highlighting the importance of proper implementation processes. In particular, it is essential to involve stakeholders and to provide reputational incentives through continuous benchmarking.     

Antigenic evolution of contemporary clade 2.3.4.4 HPAI H5 influenza A viruses and impact on vaccine use for mitigation and control

Since 2003, highly pathogenic avian influenza (HPAI) viruses of the H5 subtype have been maintained in poultry, periodically spilling back into wild migratory birds and spread to other geographic regions, with re-introduction to domestic birds causing severe impacts for poultry health, production and food sustainability. Successive waves of infection have also resulted in substantial genetic evolution and reassortment, enabling the emergence of multiple clades and subtypes within the H5 2.3.4.4 HPAI viruses. Control of AI is principally through either culling or through vaccination using conventional vaccines. Here, we antigenically and genetically characterise the emerging 2020/21 H5NX clade 2.3.4.4 strains and assess cross-reactivity to putative vaccine strains using chicken antisera. We demonstrate significant antigenic differences between commercially available poultry vaccines and currently circulating viruses suggesting that vaccination options might be suboptimal in the current outbreaks.     

多发性骨髓瘤负性相关基因DAZAP2蛋白高效表达和纯化

目的在前期的研究中，DAZAP2基因在多发性骨髓瘤（Multiple myeloma，MM）患者中表达明显下调，可能为MM的负性基因．须进一步获得DAZAP2蛋白，制备抗体，从而在蛋白水平上研究DAZAP2的表达、结构和功能．方法将原核重组质粒pQE30－DAZAP2转化大肠杆菌，阳性菌株经1 mmol／LIPTG诱导表达目的蛋白，再经过纯化和透析结果IPTG诱导4hr时，得到大量重组目的蛋白，占可溶蛋白的20％左右，经过Ni—NTA层析柱纯化。获得分子量为17kD的DAZAP2蛋白浓度为0．97mg／m1．结论DAZAP2蛋白获得高效表达，并且建立快速简便的纯化方法，目的蛋白可以用于下一步的实验．