肿瘤坏死因子α调控ERK1/2信号通路促进长骨骨样细胞凋亡

文题释义：肿瘤坏死因子α：是一种主要由巨噬细胞和单核细胞产生的促炎细胞因子,并参与正常炎症反应和免疫反应。MAPK信号通路：生物体内重要的信号转导系统之一,参与介导细胞生长、发育、分裂和分化等多种生理及病理过程,ERK是MAPK通路中极其重要的组成部分之一。激活的ERK1/2通过核转位进入细胞核,激活其下游的相关转录因子或激活胞质和胞核激酶等调控细胞的生存、增殖和分化。背景：肿瘤坏死因子α作为促炎因子可诱导成骨细胞凋亡,增强破骨细胞功能,从而造成炎症性骨破坏,但是其作用机制尚不明确。 目的：探讨炎症因子肿瘤坏死因子α对长骨骨样细胞MLO-Y4增殖、凋亡的影响及可能机制。方法：将MLO-Y4细胞分为对照组、肿瘤坏死因子α组、ERK1/2抑制剂组。肿瘤坏死因子α组用含50 μg/L肿瘤坏死因子α的α-MEM完全培养基孵育24 h,ERK1/2抑制剂组用含50 μmol/L PD98059的α-MEM完全培养基孵育24 h,对照组单纯采用α-MEM完全培养基孵育24 h,采用MTT法检测细胞增殖能力,流式细胞术检测细胞凋亡情况,丙二醛、超氧化物歧化酶、谷胱甘肽过氧化物酶试剂盒检测细胞氧化应激水平,用Western blot法测定PCNA、cleaved caspase-3、p-ERK1/2、ERK1/2的蛋白水平。结果与结论：①与对照组相比,50 μg/L肿瘤坏死因子α处理24 h后,细胞增殖能力下降,凋亡率上升;细胞脂质过氧化物丙二醛水平显著增加,而抗氧化物酶超氧化物歧化酶和谷胱甘肽过氧化物酶活性显著降低;②与对照组相比,肿瘤坏死因子α组细胞增殖相关蛋白PCNA的表达显著降低,细胞凋亡相关蛋白cleaved caspase-3的表达显著升高,p-ERK1/2的表达降低,而总蛋白ERK1/2的表达基本保持不变。ERK1/2抑制剂组上述指标与肿瘤坏死因子α组无显著差异;③结果表明,50 μg/L肿瘤坏死因子α可使长骨骨样细胞MLO-Y4增殖能力下降,细胞凋亡增多,其作用机制可能与抑制MAPK-ERK1/2信号通路的活化有关。ORCID: 0000-0003-0863-8618(史方富)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     

全内镜下腰椎板开窗减压有限元模拟建模及生物力学变化

文题释义： 腰椎有限元手术模拟建模：模型首先通过获取人体腰椎CT资料,以DICOM格式导入Mimics软件中建立L_4-5模型,再运用3-matic建立椎间盘和手术模型。将建好的模型进行网格划分,在Ansysworkbench 18.0中进行材料赋值及韧带添加,同时进行相关力学分析。 腰椎管狭窄症：是指由于腰椎中央管、侧隐窝及椎间孔的直径减少而导致的临床综合征,主要发生于65岁以上的老年人,主要病因包括椎间盘退变、小关节退变、退变性滑脱、退变性腰椎畸形等,进而引起以下腰痛及神经源性间歇性跛行为主的临床症状。 背景：全内镜下减压有效治疗腰椎管狭窄症为突破性前沿技术,相对于开放手术具有创伤小、操作可控、并发症少的特点,但其有限元力学分析鲜有报道。 目的：建立全内镜下腰椎椎板开窗有限元模型并探讨减压范围及髓核摘除对腰椎活动度及椎间盘应力分布的影响。 方法：采集1例L_4-5节段腰椎管狭窄症患者的CT 平扫数据,导入 Mimics 20.0软件中,建立退变腰椎L_4-5节段腰椎管狭窄有限元模型M。将模型M导入3-matic中进行手术模拟,分别为单侧小关节1/2切除及椎间盘1/4切除模型M1、双侧关节突1/2及椎间盘1/2切除模型M2、单侧关节突切除及椎间盘1/4切除模型M3。在ANSYS软件中对4种模型进行同等纯力偶矩的前屈、后伸、左侧弯、右侧弯、左旋转、右旋转6种工况活动及椎间盘同等载荷的力学对比分析。结果与结论：①与脊柱M模型比较,M1模型在6种工况下活动度相近,但M2和M3的活动度较M模型明显增大,特别是在左、右侧屈和前屈、后伸工况下,为 M模型整体活动度的130%-200%;②在椎间盘应力方面,M1模型在椎间盘后区、中区、右区各工况下等效应力的上升趋势不明显,在椎间盘左区、前区的等效应力有所增加,最大增加 63%,但没有出现较大的应力集中情况;而M2和M3模型,各区域椎间盘等效应力均出现较大程度上升趋势;③提示全内镜视下微创手术对不同类型腰椎管狭窄症减压手术精准可控,关节突关节切除及髓核摘除1/2以内对相应节段的生物力学稳定性影响较小,证实腰椎板开窗有限元模拟建模成功可靠,可为后续腰椎手术生物力学研究提供重要方法和依据。 ORCID: 0000-0002-9345-0515(刘金玉) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程     

成人ICU患者外周动脉导管留置与维护的最佳证据总结

目的 检索、评价和总结成人ICU患者外周动脉导管留置与维护的最佳证据。方法 系统检索加拿大安大略护理学会网站、英国国家临床优化研究所、苏格兰大学校际指南网、国际指南网、医脉通等指南网及PubMed、CINAHL、Embase、UpToDate、乔安娜布里格斯研究所循证卫生保健中心数据库、中国知网、万方等数据库内关于成人ICU患者动脉导管留置与维护相关的所有证据,包括临床决策、指南、推荐实践、证据总结、专家共识等。检索时限为建库至2019年9月。由3名研究人员对文献质量进行独立评价,结合专业人员的判断,对符合标准的文献进行资料提取。结果 共纳入文献13篇,包括决策系统1篇,指南3篇,证据总结7篇,专家共识2篇,从教育及培训、导管选择、穿刺部位及辅助技术、导管标识、皮肤消毒及无菌技术、敷料选择及更换、传感器系统、压力监测系统、冲洗液、拔除时机10个方面汇总证据,共27条。结论 本研究总结了成人ICU患者外周动脉导管留置与维护的最佳证据,可为外周动脉导管的规范化管理提供循证依据,旨在降低外周动脉导管相关并发症的发生,保证患者安全。     

Using intestinal flora to distinguish non-alcoholic steatohepatitis from non-alcoholic fatty liver

ObjectiveTo explore specific flora in mouse models of non-alcoholic steatohepatitis (NASH) to improve NASH diagnostic protocols.MethodsSixty mice were divided into normal diet (ND, 20 mice) and high-fat/high-sugar diet (HFSD) groups (40 mice). After 8 weeks of feeding, 10 mice in the ND group and 20 mice in the HFSD group were sacrificed to create the short-term ND and non-alcoholic fatty liver (NAFL) groups, respectively. After 16 weeks of feeding, the remaining mice were sacrificed to create the long-term ND and NASH groups, respectively. We then examined fecal flora, serum biochemical indices, and lipopolysaccharide and tumor necrosis factor-α levels and analyzed liver tissue.ResultsThe relative abundance of Lactobacillus, Desulfovibrio, Ruminiclostridium 9, and Turicibacter differed between NASH and NAFL mice, and the areas under the receiver operating characteristic curve of the four genera for diagnosing NASH were 0.705, 0.734, 0.737, and 0.937. The non-alcoholic fatty liver disease activity score was positively correlated with the relative abundance of Desulfovibrio (r = 0.353), Ruminiclostridium 9 (r = 0.431), and Turicibacter (r = 0.688).ConclusionsThe relative abundance of Lactobacillus, Desulfovibrio, Ruminiclostridium, and Turicibacter may help distinguish NASH from NAFL.     

Rapid Detection of New Delhi Metallo-β-Lactamase Gene and Variants Coding for Carbapenemases with Different Activities by Use of a PCR-Based In Vitro Protein Expression Method

New Delhi metallo-β-lactamase (NDM)-producing bacteria are considered potential global health threats. It is necessary to monitor NDM-1 and its variants in clinical isolates in order to understand the NDM-1 epidemic and the impact of its variants on β-lactam resistance. To reduce the lengthy time needed for cloning and expression of NDM-1 variants, a novel PCR-based in vitro protein expression (PCR-P) method was used to detect bla_NDM-1 and its variants coding for carbapenemases with different activities (functional variants). The PCR-P method combined a long-fragment real-time quantitative PCR (LF-qPCR) with in vitro cell-free expression to convert the bla_NDM-1 amplicons into NDM for carbapenemase assay. The method could screen for bla_NDM-1 within 3 h with a detection limit of 5 copies and identify functional variants within 1 day. Using the PCR-P to analyze 5 recent bla_NDM-1 variants, 2 functional variants, bla_NDM-4 and bla_NDM-5, were revealed. In the initial testing of 23 clinical isolates, the PCR-P assay correctly found 8 isolates containing bla_NDM-1. This novel method provides the first integrated approach for rapidly detecting the full-length bla_NDM-1 and revealing its functional variants in clinical isolates.     

The effect of thick fibers and large pores of electrospun poly(ε-caprolactone) vascular grafts on macrophage polarization and arterial regeneration

The vascular grafts prepared by electrospinning often have relatively small pores, which limit cell infiltration into the grafts and hinder the regeneration and remodeling of the grafts into neoarteries. To overcome this problem, macroporous electrospun polycaprolactone (PCL) scaffolds with thicker fibers (5–6 μm) and larger pores (∼30 μm) were fabricated in the present study. In vitro cell culture indicated that macrophages cultured on thicker-fiber scaffolds tended to polarize into the immunomodulatory and tissue remodeling (M2) phenotype, while those cultured on thinner-fiber scaffolds expressed proinflammatory (M1) phenotype. In vivo implantation by replacing rat abdominal aorta was performed and followed up for 7, 14, 28 and 100 d. The results demonstrated that the macroporous grafts markedly enhanced cell infiltration and extracellular matrix (ECM) secretion. All grafts showed satisfactory patency for up to 100 days. At day 100, the endothelium coverage was complete, and the regenerated smooth muscle layer was correctly organized with abundant ECM similar to those in the native arteries. More importantly, the regenerated arteries demonstrated contractile response to adrenaline and acetylcholine-induced relaxation. Analysis of the cellularization process revealed that the thicker-fiber scaffolds induced a large number of M2 macrophages to infiltrate into the graft wall. These macrophages further promoted cellular infiltration and vascularization. In conclusion, the present study confirmed that the scaffold structure can regulate macrophage phenotype. Our thicker-fiber electrospun PCL vascular grafts could enhance the vascular regeneration and remodeling process by mediating macrophage polarization into M2 phenotype, suggesting that our constructs may be a promising cell-free vascular graft candidate and are worthy for further in vivo evaluation.     

Collagen scaffolds modified with CNTF and bFGF promote facial nerve regeneration in minipigs

Most experiments of peripheral nerve repair after injury have been conducted in the rodent model but the translation of findings from rodent studies to clinical practice is needed partly because the nerve regeneration must occur over much longer distances in humans than in rodents. The reconstruction of long distance nerve injuries still represents a great challenge to surgeons who is engaged in peripheral nerve surgery. Here we used the functional nerve conduit (collagen scaffolds incorporated with neurocytokines CNTF and bFGF) to bridge a 35 mm long facial nerve gap in minipig models. At 6 months after surgery, electrophysiology assessment and histological examination were conducted to evaluate the regeneration of peripheral facial nerves. Based on functional and histological observations, the results indicated that the functional collagen scaffolds promoted nerve reconstruction. The number and arrangement of regenerated nerve fibers, myelination, and nerve function reconstruction was better in the CNTF + bFGF conduit group than the single factor CNTF or bFGF conduit group. The functional composite conduit, which exhibited favorable mechanical properties, may promote facial nerve regeneration in minipigs effectively.     

Correction: Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems

Correction for ‘Interactions between marmatite and bornite during the oxidative dissolution process in abiotic and biotic systems’ by Yanjun Zhang et al., RSC Adv., 2019, 9, 26609–26618.

Hussnain Ahmed Janjua''s name was incorrectly spelled in the published article; the corrected author list is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.