Human Omental Mesothelial Cells Impart an Immunomodulatory Landscape Impeding B- and T-Cell Activation

Mesothelial cells form the mesothelium, a simple epithelium lining the walls of serous cavities and the surface of visceral organs. Although mesothelial cells are phenotypically well characterized, their immunoregulatory properties remain largely unknown, with only two studies reporting their capacity to inhibit T cells through TGF-β and their consumption of L-arginine by arginase-1. Whether human mesothelial cells can suppress other immune cells and possess additional leukosuppressive mechanisms, remain to be addressed to better delineate their therapeutic potential for cell therapy. Herein, we generated secretomes from omental mesothelial cells (OMC) and assess their capacity to inhibit lymphocytes proliferation, suppress activated T and B cells, as well as to modify macrophage activation markers. The secretome from mesenchymal stromal cells (MSC) served as a control of immuno-suppression. Although OMC and MSC were phenotypically divergent, their cytokine secretion patterns as well as expression of inflammatory and immunomodulary genes were similar. As such, OMC- and MSC-derived secretomes (OMC-S and MSC-S) both polarized RAW 264.7 macrophages towards a M2-like anti-inflammatory phenotype and suppressed mouse and human lymphocytes proliferation. OMC-S displayed a strong ability to suppress mouse- and human-activated CD19⁺/CD25⁺ B cells as compared to MSC-S. The lymphosuppressive activity of the OMC-S could be significantly counteracted either by SB-431542, an inhibitor of TGFβ and activin signaling pathways, or with a monoclonal antibody against the TGFβ1, β2, and β3 isoforms. A strong blockade of the OMC-S-mediated lymphosuppressive activity was achieved using L-NMMA, a specific inhibitor of nitric oxide synthase (NOS). Taken together, our results suggest that OMC are potent immunomodulators.     

Platelet-Rich Fibrin Decreases the Inflammatory Response of Mesenchymal Cells

Chronic inflammation is a pathological process where cells of the mesenchymal lineage become a major source of inflammatory mediators. Platelet-rich fibrin (PRF) has been shown to possess potent anti-inflammatory activity in macrophages, but its impact on mesenchymal cells has not been investigated. The aim of this study was, therefore, to expose mesenchymal cells to inflammatory cytokines together with lysates generated from liquid platelet-poor plasma (PPP), the cell-rich buffy coat layer (BC; concentrated-PRF or C-PRF), and the remaining red clot layer (RC), following centrifugation of blood. Heating PPP generates an albumin gel (Alb-gel) that when mixed back with C-PRF produces Alb-PRF. Membranes prepared from solid PRF were also subjected to lysis. We report here that lysates of PPP, BC, and PRF decreased the cytokine-induced expression of interleukin 6 (IL6) and nitric oxide synthase (iNOS) in the bone marrow-derived ST2 cells. Consistently, PPP, BC, and PRF greatly decreased the phosphorylation and nuclear translocation of p65 in ST2 cells. The inflammatory response caused by Pam3CSK4 was reduced accordingly. Moreover, PPP, BC, and PRF reduced the enhanced expression of inflammatory mediators IL6 and iNOS in 3T3-L1 pre-adipocyte mesenchymal cells, and iNOS and CCL5 in murine calvarial cells. Surprisingly, PRF lysates were not effective in reducing the inflammatory response of human gingival fibroblasts and HSC2 epithelial cells. The data from the present study suggest that both liquid PRF and solid PRF exert potent anti-inflammatory activity in murine mesenchymal cells.     

Polycaprolactone/Chitosan Composite Nanofiber Membrane as a Preferred Scaffold for the Culture of Mesothelial Cells and the Repair of Damaged Mesothelium

Mesothelial cells are specific epithelial cells lining the serosal cavity and internal organs. Nonetheless, few studies have explored the possibility to culture mesothelial cells in a nanostructure scaffold for tissue engineering applications. Therefore, this study aims to fabricate nanofibers from a polycaprolactone (PCL) and PCL/chitosan (CS) blend by electrospinning, and to elucidate the effect of CS on the cellular response of mesothelial cells. The results demonstrate that a PCL and PCL/CS nanofiber membrane scaffold could be prepared with a comparable fiber diameter (~300 nm) and porosity for cell culture. Blending CS with PCL influenced the mechanical properties of the scaffold due to interference of PCL crystallinity in the nanofibers. However, CS substantially improves scaffold hydrophilicity and results in a ~6-times-higher cell attachment rate in PCL/CS. The mesothelial cells maintain high viability in both nanofiber membranes, but PCL/CS provides better maintenance of cobblestone-like mesothelial morphology. From gene expression analysis and immunofluorescence staining, the incorporation of CS also results in the upregulated expression of mesothelial marker genes and the enhanced production of key mesothelial maker proteins, endorsing PCL/CS to better maintain the mesothelial phenotype. The PCL/CS scaffold was therefore chosen for the in vivo studies, which involved transplanting a cell/scaffold construct containing allograft mesothelial cells for mesothelium reconstruction in rats. In the absence of mesothelial cells, the mesothelium wound covered with PCL/CS showed an inflammatory response. In contrast, a mesothelium layer similar to native mesothelium tissue could be obtained by implanting the cell/scaffold construct, based on hematoxylin and eosin (H&E) and immunohistochemical staining.     

A Fibrin Coating Method of Polypropylene Meshes Enables the Adhesion of Menstrual Blood-Derived Mesenchymal Stromal Cells: A New Delivery Strategy for Stem Cell-Based Therapies

Polypropylene (PP) mesh is well-known as a gold standard of all prosthetic materials of choice for the reinforcement of soft tissues in case of hernia, organ prolapse, and urinary incontinence. The adverse effects that follow surgical mesh implantation remain an unmet medical challenge. Herein, it is outlined a new approach to allow viability and adhesion of human menstrual blood-derived mesenchymal stromal cells (MenSCs) on PP surgical meshes. A multilayered fibrin coating, based on fibrinogen and thrombin from a commercial fibrin sealant, was optimized to guarantee a homogeneous and stratified film on PP mesh. MenSCs were seeded on the optimized fibrin-coated meshes and their adhesion, viability, phenotype, gene expression, and immunomodulatory capacity were fully evaluated. This coating guaranteed MenSC viability, adhesion and did not trigger any change in their stemness and inflammatory profile. Additionally, MenSCs seeded on fibrin-coated meshes significantly decreased CD4+ and CD8+ T cell proliferation, compared to in vitro stimulated lymphocytes (p < 0.0001). Hence, the proposed fibrin coating for PP surgical meshes may allow the local administration of stromal cells and the reduction of the exacerbated inflammatory response following mesh implantation surgery. Reproducible and easy to adapt to other cell types, this method undoubtedly requires a multidisciplinary and translational approach to be improved for future clinical uses.     

Experimental Study of Fibrin Embolization Under Shear Flow

Arterial thrombi consist mainly of platelets and fibrin, the biopolymer produced in the final step of the coagulation cascade. Thrombus fragmentation may result in occlusion of smaller distal vessels (embolization), a serious and often fatal event. The objective of this study is to investigate the role of the fibrin polymer network on the resistance of a clot to fragmentation under shear flow. For that purpose, a fibrin clot model representative of native clots is submitted to a shear flow that reproduces the pathophysiological range of shear stress.

The adhesion force due to specific fibrin/fibrin interactions is determined from the measurement of the shear stress producing 50% detachment of model particles of blood platelets embedded in the clot. This force was found to be several orders higher than the nonspecific colloidal forces between surfaces, which can, thus, be neglected. Influence of the number of fibrin monolayers in the clot model on adhesion force is investigated.     

Experimental Study of Fibrin Embolization Under Shear Flow

Arterial thrombi consist mainly of platelets and fibrin, the biopolymer produced in the final step of the coagulation cascade. Thrombus fragmentation may result in occlusion of smaller distal vessels (embolization), a serious and often fatal event. The objective of this study is to investigate the role of the fibrin polymer network on the resistance of a clot to fragmentation under shear flow. For that purpose, a fibrin clot model representative of native clots is submitted to a shear flow that reproduces the pathophysiological range of shear stress.

The adhesion force due to specific fibrin/fibrin interactions is determined from the measurement of the shear stress producing 50% detachment of model particles of blood platelets embedded in the clot. This force was found to be several orders higher than the nonspecific colloidal forces between surfaces, which can, thus, be neglected. Influence of the number of fibrin monolayers in the clot model on adhesion force is investigated.     

两种细胞培养流感病毒的滴度比较

目的探讨甲1(A1)型流感病毒在Vero细胞和MDCK细胞培养的可行性,确定最佳培养条件。方法将流感病毒接种于Vero细胞和MDCK细胞,在含有不同浓度胎牛血清或胰酶维持液中培养,于不同时间收获病毒液,检测血凝素滴度(HA)。结果胎牛血清对病毒的繁殖有明显抑制作用。加入适量胰酶(约5μg/ml)可提高病毒产量。最佳收获病毒时间为72～96h。在MDCK细胞上的病毒HA滴度高于Vero细胞。结论两种组织细胞培养流感病毒结果相近,Vero细胞和MDCK细胞均可用于培养流感病毒。     

Evaluation of Posterolateral Lumbar Fusion in Sheep Using Mineral Scaffolds Seeded with Cultured Bone Marrow Cells

The objective of this study is to investigate the efficacy of hybrid constructs in comparison to bone grafts (autograft and allograft) for posterolateral lumbar fusion (PLF) in sheep, instrumented with transpedicular screws and bars. Hybrid constructs using cultured bone marrow (BM) mesenchymal stem cells (MSCs) have shown promising results in several bone healing models. In particular, hybrid constructs made by calcium phosphate-enriched cells have had similar fusion rates to bone autografts in posterolateral lumbar fusion in sheep. In our study, four experimental spinal fusions in two animal groups were compared in sheep: autograft and allograft (reference group), hydroxyapatite scaffold, and hydroxyapatite scaffold seeded with cultured and osteoinduced bone marrow MSCs (hybrid construct). During the last three days of culture, dexamethasone (dex) and beta-glycerophosphate (β-GP) were added to potentiate osteoinduction. The two experimental situations of each group were tested in the same spinal segment (L4–L5). Spinal fusion and bone formation were studied by clinical observation, X-ray, computed tomography (CT), histology, and histomorphometry. Lumbar fusion rates assessed by CT scan and histology were higher for autograft and allograft (70%) than for mineral scaffold alone (22%) and hybrid constructs (35%). The quantity of new bone formation was also higher for the reference group, quite similar in both (autograft and allograft). Although the hybrid scaffold group had a better fusion rate than the non-hybrid scaffold group, the histological analysis revealed no significant differences between them in terms of quantity of bone formation. The histology results suggested that mineral scaffolds were partly resorbed in an early phase, and included in callus tissues. Far from the callus area the hydroxyapatite alone did not generate bone around it, but the hybrid scaffold did. In nude mice, labeled cells were induced to differentiate in vivo and monitored by bioluminescence imaging (BLI). Although the cultured MSCs had osteogenic potential, their contribution to spinal fusion when seeded in mineral scaffolds, in the conditions disclosed here, remains uncertain probably due to callus interference with the scaffolds. At present, bone autografts are better than hybrid constructs for posterolateral lumbar fusion, but we should continue to seek better conditions for efficient tissue engineering.     

microRNAs Are Abundant and Stable in Platelet-Rich Fibrin and Other Autologous Blood Products of Canines

Various microRNAs (miRNAs) present in autologous blood products of canines have not been studied recently. We aimed to elucidate the existence of miRNAs in platelet-rich fibrin (PRF) and the stability of canine autologous blood products under various storage conditions. Total RNAs were isolated from PRF and other autologous blood products following newly adapted protocols used in commercial kits for plasma and tissue samples. Quantitative real-time polymerase chain reaction analysis (qPCR) was used to detect miRNAs in autologous blood products. The miR-16, miR-21, miR-155, and miR-146a were abundant in PRF and other autologous blood products of canines. Furthermore, we found they could maintain stability under protracted freezing temperatures of −30 °C for at least one month. Our findings revealed that PRF might be a stable resource for various canine miRNAs.     

细胞中酪氨酸酶活性的生化酶学法测定

根据Hideya A.和Wrathal J.介绍的方法,建立了细胞中酪氨酸酶活性测定的改进型生化酶学方法,以适应美白化妆品研究开发的需要。结果显示：改进后的方法,精确度测试的变异系数均值为6.2%,准确度测试P值＞0．05,稳定性测试,方差分析无显著性差异。     

Conjugated Linoleic Acids Have Anti-Inflammatory Effects in Cultured Endothelial Cells

Conjugated linoleic acid (CLA) isomers may have a role in preventing atherosclerosis through the modulation of inflammation, particularly of the endothelium. However, whether low concentrations of CLAs are able to affect basal unstimulated endothelial cell (EC) responses is not clear. The aim of this study was to evaluate the effects of two CLAs (cis-9, trans-11 (CLA9,11) and trans-10, cis-12 (CLA10,12)) on the basal inflammatory responses by ECs. EA.hy926 cells (HUVEC lineage) were cultured under standard conditions and exposed to individual CLAs for 48 h. Both CLAs were incorporated into ECs in a dose-dependent manner. CLA9,11 (1 μM) significantly decreased concentrations of MCP-1 (p < 0.05), IL-6 (p < 0.05), IL-8 (p < 0.01) and RANTES (p < 0.05) in the culture medium. CLA10,12 (10 μM) decreased the concentrations of MCP-1 (p < 0.05) and RANTES (p < 0.05) but increased the concentration of IL-6 (p < 0.001). At 10 μM both CLAs increased the relative expression of the NFκβ subunit 1 gene (p < 0.01 and p < 0.05, respectively), while decreasing the relative expression of PPARα (p < 0.0001), COX-2 (p < 0.0001) and IL-6 (p < 0.0001) genes. CLA10,12 increased the relative expression of the gene encoding IκK-β at 10 μM compared with CLA9,11 (p < 0.05) and increased the relative expression of the gene encoding IκBα at 1 and 10 μM compared with linoleic acid (both p < 0.05). Neither CLA affected the adhesion of monocytes to ECs. These results suggest that low concentrations of both CLA9,11 and CLA10,12 have modest anti-inflammatory effects in ECs. Thus, CLAs may influence endothelial function and the risk of vascular disease. Nevertheless, at these low CLA concentrations some pro-inflammatory genes are upregulated while others are downregulated, suggesting complex effects of CLAs on inflammatory pathways.     

摩擦型高强螺栓在玻璃结构中的连接应用研究

通过试验的方法论证了摩擦型高强螺栓在玻璃结构连接应用的可行性,并根据试验数据归纳得出了玻璃与钢板的静摩擦系数,为以后的工程实践提供了设计依据。     

单螺杆挤出机固体输送段摩擦系数的研究

介绍了当今固体输送理论的研究热点之一———摩擦系数的研究,对其进行了理论分析,并分析了影响摩擦系数的各种因素。     

Mixed Pro- and Anti-Oxidative Effects of Pomegranate Polyphenols in Cultured Cells

In recent years, the number of scientific papers concerning pomegranate (Punica granatum L.) and its health properties has increased greatly, and there is great potential for the use of bioactive-rich pomegranate extracts as ingredients in functional foods and nutraceuticals. To translate this potential into effective strategies it is essential to further elucidate the mechanisms of the reported bioactivity. In this study HepG2 cells were supplemented with a pomegranate fruit extract or with the corresponding amount of pure punicalagin, and then subjected to an exogenous oxidative stress. Overall, upon the oxidative stress the gene expression and activity of the main antioxidant enzymes appeared reduced in supplemented cells, which were more prone to the detrimental effects than unsupplemented ones. No differences were detected between cells supplemented with the pomegranate juice or the pure punicalagin. Although further studies are needed due to the gaps existing between in vitro and in vivo studies, our results suggest caution in the administration of high concentrations of nutraceutical molecules, particularly when they are administered in concentrated form.     

The Immunomodulator Dimethyl Itaconate Inhibits Several Key Steps of Angiogenesis in Cultured Endothelial Cells

The dimethyl derivative of the immunomodulator itaconate has been previously shown to have anti-inflammatory, anti-oxidative, and immunomodulatory effects. In the present work, we evaluate the potential of dimethyl itaconate as an anti-angiogenic compound by using cultured endothelial cells and several in vitro assays that simulate key steps of the angiogenic process, including endothelial cell proliferation, migration, invasion, and tube formation. Our results show that dimethyl itaconate interferes with all the previously mentioned steps of the angiogenic process, suggesting that dimethyl itaconate behaves as an anti-angiogenic compound.     

橡胶的摩擦性能对其加工的影响

介绍了橡胶加工中研究生胶与金属表面摩擦性能的意义和进展。由微观和唯象分析建立了橡胶粘附摩擦的理论模型。通过对模型的分析和实验验证,提出了提高加工设备生产能力的新途径：(1)密炼机、挤出机、压延机温度控制采用温水冷却，使其处于最佳工作状态；(2)通过合理选择设备材料，改变材料表面能来增大胶料与它们之间的摩擦力；(3)在压力较大的条件下，在密炼室或机简内壁与轴线同方向加工浅的光滑槽可明显改善加工性能。     

改性黄土内摩擦角变化研究

通过改性黄土抗剪强度试验,研究出黄土在添加膨润土、石灰、水泥和水泥一粉煤灰混合材料后内摩擦角的变化趋势。黄土在添加膨润土过程中,随着膨润土的添量增大到一定程度时,土体的内摩擦角是减小的。这主要是因为黏粒舍量的增加,土体在抵抗剪切变形过程中,土体颗粒克服爬坡和咬合阻力所做的功减小,此时剪应力大部由黏聚力承担。石灰、水泥和水泥-粉煤灰混合材料加入土体中后,形成大的团聚体结构,加强了土体颗粒之间互相嵌合度和摩擦面积,土体的内摩擦角得到不同程度的增大。因此,根据工程需要,向黄土中添加不同的改性材料,使土体的性质满足工程需要是完全可行的。     

PVC密封型材低摩擦系数涂料合成工艺条件的优选

对PVC密封型材低摩擦系数涂料的生产从反应机理、合成工艺路线、反应条件、原料选择、产品的技术标准以及各项技术指标的研制进行全面介绍     

黄芪多糖对胃癌细胞上清液中培养的树突状细胞分化成熟及功能的影响

目的探讨黄芪多糖对胃癌细胞SCG-7901上清液中培养的树突状细胞(Dendritic cells,DC)分化成熟及功能的影响,分析黄芪多糖抗癌的作用机制。方法将人外周血分离的单核细胞加入含重组人粒细胞-巨噬细胞集落刺激因子(rhGMCSF)和重组人白细胞介素的培养液中,随机分为空白组(以RPMI1640培养液培养)、干预组(以黄芪多糖干预后的胃癌细胞上清液培养)、对照组(以胃癌细胞上清液培养)。混合培养48h后,显微镜下观察DC成熟过程中的形态学变化,流式细胞术检测DC的表型(CD40、CD80),混合同种淋巴细胞增殖反应(Mixed lymphocyte reaction,MLR)检测DC的增殖效应。结果与对照组比较,空白组和干预组DC的CD40和CD80的表达均明显增加(P<0.05),刺激同种淋巴细胞增殖效应明显增强(P<0.05);干预组DC CD40和CD80的表达阳性率及刺激同种淋巴细胞增殖效应均明显低于空白组(P<0.05)。结论在体外,黄芪多糖可有效对抗胃癌细胞上清液引起的对DC分化成熟和功能的抑制。     

水力管网综合摩阻损失的计算

通过构建综合摩阻系数建立管网摩阻损失数学模型,以此分析和简化复杂的浆体管网,并编制计算程序使复杂管网的水力计算快捷简便,从而为管网设计和动力设备选用提供设计依据,在管道网络工程应用上实际可行。