Long non-coding RNAs in stem cells and cancer

An overwhelming majority of the transcribed genome encodes for non-coding RNA(ncR NA) sequences. Deep sequencing of the transcriptome has uncovered tens of thousands of long ncR NA(lncR NA) sequences. However, little is known regarding the possible functions for a vast majority of these sequences. Among those lncR NAs whose function has been experimentally validated, most serve as regulators of gene expression. LncR NAs have been found to be critical to development and homeostasis and they have been implicated in several pathologies including cancer. Here, we examine the functions and underlying mechanisms of lnc RNAs in stem cells and in cancer biology, areas linked by the actions of lncR NAs.

Cemented versus uncemented stems for revision total hip replacement:A systematic review and meta-analysis

BACKGROUND The popularity of uncemented stems in revision total hip arthroplasty(THA)has increased in the last decade.AIM To assess the outcomes of both cemented and uncemented stems after mid-term follow up.METHODS This study was performed following both the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement and the Cochrane Handbook for systematic reviews and meta-analysis guidelines.Articles were chosen irrespective of country of origin or language utilized for the article full texts.This paper included studies that reviewed revision THA for both cemented or uncemented long stems.RESULTS Three eligible studies were included in the meta-analysis.Analysis was conducted by using Review Manager version 5.3.We computed the risk ratio as a measure of the treatment effect,taking into account heterogeneity.We used random-effect models.There were no significant differences found for intraoperative periprosthetic fractures[risk ratio(RR)=1.25;95%confidence interval(CI):0.29-5.32;P=0.76],aseptic loosening(RR=2.15,95%CI:0.81-5.70;P=0.13),dislocation rate(RR=0.50;95%CI:0.10-2.47;P=0.39),or infection rate(RR=0.99,95%CI:0.82-1.19;P=0.89),between the uncemented and the cemented long stems for revision THA after mid-term follow-up.CONCLUSION This study has evaluated the mid-term outcomes of both cemented and uncemented stems at first-time revision THA.In summary,there were no significant differences in the dislocation rate,aseptic loosening,intraoperative periprosthetic fracture and infection rate between the two cohorts.

A Neural Based Modeling Approach for Drying Kinetics Analysis of Mint Branches and Their Fractions (Leaves and Stems)

This work is aimed at investigating regular mint (Mentha × villosa) drying behavior and assessing how the heterogeneous composition of plants affects their drying kinetics. Drying kinetics and sorption isotherms were evaluated for whole branches and their fractions (leaves and stems). Stems and leaves were characterized by measurement of dimensions, apparent density and initial moisture content. The moisture sorption isotherms were obtained under temperatures of 30°C, 40°C and 50°C for branches, stems and leaves and the data were fitted to the GAB model. Mint branches and their fractions were oven dried at temperatures from 40°C to 70°C?and were obtained kinetic curves for each part. Water sorption patterns were similar for leaves and stems and the GAB model described well the sorption behavior of both materials. At a constant temperature, the drying rates were higher for leaves in comparison to stems and the differences increased as the temperature was raised. Therefore, depending on drying conditions, the moisture distribution in dried branches might be significantly different. Since the leaves constitute the major fraction in branches, the drying rates of branches were closer to those of leaves. The kinetic curves were fitted to a diffusion model based on an analytical solution of Fick’s second diffusion law and to an empirical model based on artificial neural network (ANN). The results showed that the model based on the ANN predicted the drying kinetics of the different parts better than the diffusive model. A single network was built to describe the kinetic behavior of branches and fractions in the whole range of temperatures investigated. The diffusive model based on fitting effective diffusivity did not provide good predictions of moisture content, probably because neither the dependence of effective diffusivity on the moisture content nor the heterogeneity and shrinking of static beds were considered.

Long-term phenotypic characterization of human bone marrow and adipose tissue derived mesenchymal stromal cells

We present methods to characterize mesenchymal stromal cells (MSC) over long time periods in vitro. The methods entail passaging cells multiple times and performing differentiation studies with the cells at each passage. Using an array of surface markers and flow cytometric quantification, the data can be correlated to traditional measures of differentiation such as PCR and staining. Using these methods to quantify the amount of differentiation, we concluded that many common MSC markers do not specifically define MSCs with true stem cell properties. Additionally, adipose-derived as opposed to bone marrow-derived MSCs show long-term CD34+ labeling. The methods described can be used to help identify stem cell markers and to characterize the state of stem cells in vitro. Compiling these data from multiple laboratories would be helpful to determine source, extraction and culture methods needed to obtain high yields of useful stem cells.

The finite element analysis of cemented long and short stem prosthetic replacement in aged patients with comminuted intertrochanteric fracture

Objective To investigate the stress distribution of the femur after cemented prosthetic replacement in aged patients with comminuted intertrochanteric fracture and to analyze the difference of stress distribution between cemented long

Long non-coding RNA: The functional regulator of mesenchymal stem cells

Mesenchymal stem cells(MSCs) are a subset of multipotent stroma cells residing in various tissues of the body. Apart from supporting the hematopoietic stem cell niche, MSCs possess strong immunoregulatory ability and multiple differentiation potentials. These powerful capacities allow the extensive application of MSCs in clinical practice as an effective treatment for diseases.Therefore, illuminating the functional mechanism of MSCs will help to improve their curative effect and promote their clinical use. Long noncoding RNA(LncRNA) is a novel class of noncoding RNA longer than 200 nt. Recently,multiple studies have demonstrated that LncRNA is widely involved in growth and development through controlling the fate of cells, including MSCs. In this review, we highlight the role of LncRNA in regulating the functions of MSCs and discuss their participation in the pathogenesis of diseases and clinical use in diagnosis and treatment.

The Rheological Property and Foam Morphology of Linear Polypropylene and Long Chain Branching Polypropylene

The rheological behavior, thermal properties and foam morphology of linear polypropylene and long chain branching polypropylene prepared through UV irradiation reactive extrusion were studied by rheological test, melt index test, DSC and supercritical carbon dioxide foaming technology. Rheological test and melt index test confirmed that under UV irradiation and extrusion, adding photo-initiator and cross- linking agent could achieve the purpose of branching, thus improved the melt strength of polypropylene effectively. The DSC results revealed that with the introducing of long chain branching, the melting range of the polypropylene broadened and the crystallization temperature increased. Owing to the introduction of long chain branches, polypropylene exhibited higher melt strength and strain hardening behavior. Compared with linear polypropylene, the foam morphologies of long chain branching polypropylene were more uniform.

Architecture of stem and branch affects yield formation in short season cotton

The cotton direct seeding after wheat(rape) harvested is under trial and would be the future direction at the Yangtze River Valley region of China.The objective of this study was to quantify the effects of branch and stem architecture on cotton yield and identify the optimal cotton architecture to compensate the yield loss due to the reduction of individual production capacity under high planting density in the direst seeding after wheat harvested cropping system.The characteristics of the stem and branch architecture and the relationships between architecture of the stem and branch with yield formation were studied on eight short season cotton cultivars during 2015 and 2016 cotton growth seasons.Based on the two years results,three cultivars with different architectures of stem and branch were selected to investigate the effect of mepiquat chloride(MC) application on the architecture of the stem and branch,boll retention,and the yield in 2017.Significant differences were observed on plant height,all fruiting nodes to branches ratio(NBR) in the cotton plant,and the curvature of the fruiting branch(CFB) among the studied cultivars.There were three types of stem and fruiting branch structures: Zhong425 with stable and suitable plant height and NBR(about 90 cm and 2.5,respectively),high CFB(more than 10.0),and high boll retention speed and seed cotton yield;Siyang 822 with excessive plant height and NBR,low CFB,and low boll retention speed and seed cotton yield;and other studied cultivars with unstable structure of stem and branch,boll retention speed,and seed cotton yield across years.And MC application could promote the appropriate plant height and NBR and high CFB and thus resulted in high boll retention speed and the yield.The results suggested that the suitable plant height and NBR(about 90 cm and 2.5 respectively),and high CFB(more than 10.0),which was related to both genotype and cultural practice,could promote the higher boll retention speed and seed cotton yield.

A Comparison of Two Horsechestnut Street Tree Plantings in Kiev and Pripyat, Ukraine

Branch and main stem defects of horsechestnut trees (Aesculus hippocastanum L.) in Pripyat, Ukraine, abandoned in 1986, and un-maintained since then, were compared to managed trees of the same species and similar age in the city of Kiev, Ukraine. Trees in Kiev sustained more trunk injuries, and numerous pruning wounds, and developed significantly more branch defects (especially codominant stems) in their canopies compared to trees in Pripyat. Although Kiev trees had larger stem diameters, the overall quality of their form was reduced compared to street trees in Pripyat. Pripyat horsechestnuts grew with competition from other, invading trees thus, experienced shading of their lower canopies and significant competition for light and had smaller bole diameters. Effects of the Chernobyl nuclear disaster on trees in the Nuclear Exclusion Zone are also discussed.

Long non-coding RNA SNHG16 promotes human placenta-derived mesenchymal stem cell proliferation capacity through the PI3K/AKT pathway under hypoxia

BACKGROUND The effect of hypoxia on mesenchymal stem cells(MSCs)is an emerging topic in MSC biology.Although long non-coding RNAs(lncRNAs)and messenger RNAs(mRNAs)are reported to play a critical role in regulating the biological characteristics of MSCs,their specific expression and co-expression profiles in human placenta-derived MSCs(hP-MSCs)under hypoxia and the underlying mechanisms of lncRNAs in hP-MSC biology are unknown.AIM To reveal the specific expression profiles of lncRNAs in hP-MSCs under hypoxia and initially explored the possible mechanism of lncRNAs on hP-MSC biology.METHODS Here,we used a multigas incubator(92.5%N_(2),5%CO_(2),and 2.5%O_(2))to mimic the potential of hP-MSCs.RNA sequencing technology was applied to identify the exact expression profiles of lncRNAs and mRNAs under hypoxia.RESULTS We identified 289 differentially expressed lncRNAs and 240 differentially expressed mRNAs between the hypoxia and normoxia groups.Among them,the lncRNA SNHG16 was upregulated under hypoxia,which was also validated by reverse transcription-polymerase chain reaction.SNHG16 was confirmed to affect hP-MSC proliferation rates using a SNHG16 knockdown model.SNHG16 overexpression could significantly enhance the proliferation capacity of hP-MSCs,activate the PI3K/AKT pathway,and upregulate the expression of cell cycle-related proteins.CONCLUSION Our results revealed the specific expression characteristics of lncRNAs and mRNAs in hypoxiacultured hP-MSCs and that lncRNA SNHG16 can promote hP-MSC proliferation through the PI3K/AKT pathway.

Long noncoding RNAs in mesenchymal stromal/stem cells osteogenic differentiation:Implications in osteoarthritis pathogenesis

This letter focuses on a recently published article that provided an exceptional description of the effect of epigenetic modifications on gene expression patterns related to skeletal system remodeling.Specifically,it discusses a novel modality of epigenetic regulation,the long noncoding RNAs(lncRNAs),and provides evidence of their involvement in mesenchymal stromal/stem cells osteo-/adipogenic differentiation balance.Despite focus on lncRNAs,there is an emerging cross talk between lncRNAs and miRNAs interaction as a novel mechanism in the regulation of the function of the musculoskeletal system,by controlling bone homeostasis and bone regeneration,as well as the osteogenic differentiation of stem cells.Thus,we touched on some examples to demonstrate this interaction.In addition,we believe there is still much to discover from the effects of lncRNAs on progenitor and non-progenitor cell differentiation.We incorporated data from other published articles to review lncRNAs in normal progenitor cell osteogenic differentiation,determined lncRNAs involved in osteoarthritis pathogenesis in progenitor cells,and provided a review of lncRNAs in non-progenitor cells that are differentially regulated in osteoarthritis.In conclusion,we really enjoyed reading this article and with this information we hope to further our understanding of lncRNAs and mesenchymal stromal/stem cells regulation.

An addition of medium-dose ATG to conditioning regimens favours the long-term survival of patients with allogeneic hematopoietic stem cell transplantation

Long-term survival of 116 leukemia/MDS patients received allo-SCT conditioned by a regimen with ATG-F or without ATG-F was analysed, together with the impact of ATG-F on the long-term survival, GVHD and disease relapse. Seventy patients received an ATG-F containing conditioning regimen FBCA, and 46 patients received a non-ATG-F FBC regimen. The FBCA regimen was associated with a 5-year survival of 65.4% in the complete HLA-matched group and 39.3% in the HLA-mismatched group. The difference between the two groups was significant (P = 0.012). For the FBC conditioning regimen, the 5-year overall survival of HLA-matched patients and the HLA-mismatched patients was 34.2% and 24.2% respectively (P = 0.216). The incidence of cGVHD was 32.9% and 83.6% in the FBCA and FBC condition regimen group respectively. Only 2.9% of the cases showed extensive cGVHD in the FBCA group while it was 69.4% in the FBC group (P = 0.00). Multivariate analysis indicated that relapse was related to the disease status and HLA typing, but unrelated to the conditioning regimens whether or not ATG-F was used (HR 0.54, P = 0.109). We conclude that the addition of ATG-F to conditioning regimen favours the longterm survival of allo-SCT.

Clinical Significance of Pulmonary Function Tests in Long-Term Survivors after Myeloablative Allogeneic Hematopoietic Stem Cell Transplantation

We retrospectively assessed long-term pulmonary function in adults surviving for ≥5 years after myeloablative allogeneic hematopoietic stem cell transplantation and identified risk factors for late-onset noninfectious pulmonary complications. Among 174 patients undergoing transplantation for hematologic malignancies between May 1994 and December 2004, 81 long-term survivors were evaluated. Pulmonary function tests (PFTs) were performed before conditioning, 3 months and 1 year after transplantation, and then annually. Eight patients (10%) had abnormal pulmonary function before transplantation, but this was not associated with late changes in PFTs. Patients with chronic graft-versus-host disease (GVHD) showed a significant decline of lung function after 3 years when compared with patients without chronic GVHD. Abnormal pretransplantation lung function was associated with pulmonary chronic GVHD according to National Institutes of Health criteria (score 0, n = 58;score 1, n = 14;score 2, n = 6;score 3, n = 3). Five patients with late-onset noninfectious pulmonary complications showed a decline of lung function at 1 year after transplantation. Only chronic GVHD was significantly related to late-onset noninfectious pulmonary complications. In conclusion, abnormal lung function before transplantation may be associated with a decline in pulmonary function within 1 year after transplantation, but late-onset noninfectious pulmonary complications could not be predicted from pretransplantation lung function.

聚乙烯分子链结构差异对其介电性能的影响

为探究国内外聚乙烯电缆料性能差异产生的原因,本文通过凝胶渗透色谱(GPC)、旋转流变测试以及自成核退火热分级(SSA)等方法测试了材料的分子量分布、长支链含量以及短支链含量,探讨了一种国产和两种进口500kV交联聚乙烯电缆料的分子链结构与其介电性能的关系。结果表明:聚乙烯体内长支链含量从小到大的顺序为:国产样品、进口B样品、进口A样品;短支链含量从小到大的顺序为:进口B样品、进口A样品、国产样品。其中,进口A样品中较高的长支链含量,有利于分子有序排列和结晶的形成,进而提高其耐压等级;国产样品过高的短支链含量会阻碍分子结晶,导致其击穿场强较低。此外,3种聚乙烯分子链结构的差异对其介电常数、介质损耗因数和电阻率影响不大。

外侧入路和后外侧入路生物型长柄假体人工髋关节置换术治疗股骨转子间不稳定性骨折的效果对比

目的:探究不同入路生物型长柄假体人工髋关节置换术(THA)的疗效对比。方法:选择104例股骨转子间不稳定性骨折患者为研究对象,患者均行生物型长柄假体THA术治疗。根据患者手术入路的不同分为外侧组(n=48)与后外侧组(n=56)。比较两组患者围手术期指标、并发症发生情况、手术前、术后2 d及6个月Harris、Aubigné-Postel评分。结果:后外侧组围手术期指标均低于外侧组(P<0.05);两组手术并发症总发生率差异无统计学意义(P>0.05);术后2 d、6个月,两组髋关节评分均上升(P<0.05),且后外侧组术后各时间点Harris评分均高于外侧组(P<0.05);后外侧组优良率(85.71%)与外侧组(75.00%)比较,差异无统计学意义(P>0.05)。结论:外侧入路与后外侧入路生物型长柄假体THA术均能治疗股骨转子间不稳定性骨折,但后外侧组疗效更好,并发症更少,值得推广。

茂金属聚乙烯薄膜料的结构与性能研究

采用凝胶渗透色谱(GPC)、核磁共振(^(13)C-NMR)、连续自成核退火热分级(SSA)、动态旋转流变等分析方法对3种茂金属聚乙烯(PE)薄膜料的结构与性能进行了研究。结果表明:这3种茂金属薄膜料密度较为接近。但由于使用了不同类型的茂金属催化剂,它们的结构和性能存在着一定的差异。使用宽分布茂金属催化剂生产的PE薄膜料,具有相对较宽的相对分子质量分布,熔流比高,并且含有一定量的长支链结构,因此具有优异的加工性能。而使用窄分布茂金属催化剂生产的薄膜料,其相对分子质量较高且分布较窄,这使得其熔体强度较高,但制备的薄膜“鱼眼”数量较多。

脐带间充质干细胞外泌体LncRNA H19修复软骨损伤的机制

背景:脐带间充质干细胞已被证明对软骨损伤有治疗作用,外泌体是脐带间充质干细胞在体内发挥治疗作用的主要载体。课题组前期发现LncRNA H19是介导脐带间充质干细胞外泌体调控软骨细胞活性的重要活性分子,LncRNA H19可以吸附miR-29b-3p从而促进软骨细胞的增殖再生,但是其下游机制仍未清楚。目的:从外泌体和LncRNAs角度揭示脐带间充质干细胞治疗软骨损伤的具体机制,为软骨损伤的治疗提供新的靶点。方法:构建稳定过表达LncRNA H19的脐带间充质干细胞,采用超速离心提取外泌体(H19-Exos);采用透射电镜、纳米颗粒跟踪分析、Western blot和外泌体摄取实验鉴定外泌体;通过Western blot、qPCR和双荧光素酶报告基因系统检测miR-29b-3p过表达和沉默对TGF-β1/Smad3通路的影响;通过特异性TGF-β1/Smad3抑制剂在体内外反向验证H19-Exos对软骨再生的生物学作用。结果与结论:①H19-Exos在电镜下为典型的杯状,粒径在130 nm左右,均表达CD63、CD81和TSG1010特性蛋白;②过表达miR-29b-3p可以同时下调TGF-β1、Smad3的mRNA和蛋白水平,而沉默miR-29b-3p后,TGF-β1、Smad3的mRNA和蛋白水平上调;③双荧光素酶报告基因系统检测发现miR-29b-3p对下游靶基因TGF-β1和Smad3活性影响有显著差异;④膝关节腔内注射Ⅱ型胶原酶成功建立大鼠骨关节炎模型,H19-Exos可显著促进软骨再生,且特异性TGF-β1/Smad3抑制剂SB-431542在体内外均可阻断H19-Exos对软骨再生的生物学作用;⑤该研究系统论证了高表达LncRNA H19脐带间充质干细胞来源外泌体对软骨再生的促进作用,具体机制为LncRNA H19通过靶向miR-29b-3p/TGF-β1/Smad3通路促进软骨再生。

不同方法治疗老年股骨转子间不稳定骨折疗效对比

目的对比分析生物型加长柄关节置换与股骨近端防旋髓内钉内固定治疗老年股骨转子间不稳定骨折的临床效果。方法选取2019年6月至2021年6月安阳市第三人民医院收治的104例老年股骨转子间不稳定骨折患者作为研究对象,根据不同手术治疗方式将其分为置换组(52例)和固定组(52例),置换组患者采用生物型加长柄关节置换术治疗,固定组患者采用股骨近端防旋髓内钉内固定术治疗,对比观察两组患者围术期相关指标、髋关节恢复情况、生活质量及术后不良事件发生情况。结果置换组患者术中出血量明显多于固定组、手术时间明显长于固定组(t=5545、5150,P均<0001),而首次下床活动时间及住院时间与固定组无明显差异(t=1933、1619,P=0056、0109)。术后12个月,置换组患者髋关节恢复优良率为8077%,明显高于固定组患者的髋关节恢复优良率6154%(χ^(2)=4685,P=0030);置换组患者健康调查量表36(SF-36)中的躯体功能、躯体疼痛、总体健康、生理功能评分均明显高于固定组(t=3062、2868、3028、3440,P=0003、0005、0003、0001)。置换组患者术后不良事件发生率为577%,明显低于固定组患者的术后不良事件发生率2115%(χ^(2)=5283,P=0022)。结论与股骨近端防旋髓内钉内固定相比,生物型加长柄关节置换虽会增加老年股骨转子间不稳定骨折患者术中出血量,延长手术时间,但能够提高患者髋关节功能及生活质量,降低不良事件发生风险,临床效果更佳。

高熔体强度聚丙烯的制备及性能表征

采用等规聚丙烯(iPP)为粉料、过氧化苯甲酰(BPO)为引发剂、三羟甲基丙烷三丙烯酸酯(TMPTA)为接枝单体、苯乙烯(St)为共聚单体,使用双螺杆挤出机熔融接枝制备无凝胶的高熔体强度聚丙烯(HMSPP)。傅里叶红外光谱(FTIR)和凝胶渗透色谱(GPC)的结果表明单体已成功接枝在聚丙烯分子链上。差示扫描量热仪(DSC)的分析结果表明HMSPP结晶温度提高了11.8℃。流变测试结果显示,HMSPP可呈现明显的剪切稀化现象,并具有更长的松弛时间和更低的损耗因子,充分证明了长支链结构的存在。与iPP相比,HMSPP的熔体强度从0.03 N提高到0.37 N,同时其冲击强度、拉伸强度和弯曲模量分别提高了89.1%、17.5%、42.6%。