Interaction of eosinophils with endothelial cells is modulated by prostaglandin EP4 receptors

Eosinophil extravasation across the endothelium is a key feature of allergic inflammation. Here, we investigated the role of PGE(2) and its receptor, E-type prostanoid receptor (EP)-4, in the regulation of eosinophil interaction with human pulmonary microvascular endothelial cells. PGE(2) and the EP4 receptor agonist ONO AE1-329 significantly reduced eotaxin-induced eosinophil adhesion to fibronectin, and formation of filamentous actin and gelsolin-rich adhesive structures. These inhibitory effects were reversed by a selective EP4 receptor antagonist, ONO AE3-208. PGE(2) and the EP4 agonist prevented the activation and cell-surface clustering of β2 integrins, and L-selectin shedding of eosinophils. Under physiological flow conditions, eosinophils that were treated with the EP4 agonist showed reduced adhesion to endothelial monolayers upon stimulation with eotaxin, as well as after TNF-α-induced activation of the endothelial cells. Selective activation of EP1, EP2, and EP3 receptors did not alter eosinophil adhesion to endothelial cells, whereas the EP4 antagonist prevented PGE(2) from decreasing eosinophil adhesion. Finally, eosinophil transmigration across thrombin- and TNF-α-activated endothelial cells was effectively reduced by the EP4 agonist. These data suggest that PGE(2) -EP4 signaling might be protective against allergic responses by inhibiting the interaction of eosinophils with the endothelium and might hence be a useful therapeutic option for controlling inappropriate eosinophil infiltration.     

肿瘤细胞迁移模式及其转换调控的研究进展

肿瘤细胞在三维培养基质中主要以两种模式迁移,即间充质式迁移(mesenchymal migration)和阿米巴式迁移(amoeboid migration)。本文总结分析了肿瘤细胞在不同迁移模式中的运动特征和不同迁移模式形成的内在动因,以及一定条件下迁移模式间相互转换的诱发因素。了解这些变化及不同迁移模式转换间的内在联系,将会加深对肿瘤细胞在不同条件下迁移特性及其过程机制的认识,进而为控制肿瘤细胞恶性转移找到更为有效的措施。     

Voltammetry in the absence of excess supporting electrolyte – ECE-DISP1 reactions: The electrochemical reduction of 2-nitrobromobenzene in acetonitrile solvent

The reduction of 2-nitrobromobenzene in acetonitrile has been studied in the presence and near absence of supporting electrolyte at a mercury hemispherical microelectrode. In the presence of a high concentration of tetra-n-butylammonium perchlorate, voltammetric studies over a wide range of voltage scan rates spanning the transition from convergent to linear diffusion confirms the reduction mechanism as DISP1, rather than ECE, as previously thought by the majority of earlier studies. A rate constant of approximately 23 s⁻¹ at 298 K was inferred for the loss of bromide ion from the 2-nitrobromobenzene radical anion. In the presence of weak support, with concentration ratios of electrolyte to reactant of 5 and 0.5, the Nernst-Planck-Poisson system of equations were used to model the coupled diffusion–migration–reaction. It was found the both the mechanism of reaction and the derived homogeneous kinetics were unchanged in the near absence of supporting electrolyte.     

Professional image and intention to emigrate among Israeli nurses and nursing students

Under globalization, nurse migration has become an increasingly widespread phenomenon. One factor motivating it might be nurses' perception of the profession's image. The purpose of this study was to examine the connection between Israeli working nurses' and student nurses' perceptions of nursing's professional image and their intention to emigrate. One hundred thirty-two nurses and students participated in this cross-sectional study, the data collected by means of a structured questionnaire. Fifty-five percent of the sample were considering emigration or definitely intended to emigrate. Significantly more participants under the age of 35 were considering or had decided to emigrate than older participants. No statistically significant correlation was found between intention to migrate and perception of the profession's image. However, perceived professional image, as a component of professional reasons for emigrating (to get a better salary, working conditions, etc.), did contribute to the intention to emigrate.     

MIF在幽门螺杆菌L型相关胃癌中的表达及临床意义

目的研究巨噬细胞移动抑制因子(MIF)在胃癌组织中的表达及临床意义,并探讨其机制。方法应用免疫组化(SP法)和革兰染色检测80例胃癌组和50例对照组的Hp-L型感染,免疫组化(SP法)检测上述组织MIF蛋白表达。结果胃癌组MIF表达阳性率高于其对照组(P<0.05),且表达水平与浸润深度、淋巴结转移、临床分期、分化程度有关(P<0.05),与性别、年龄无关(P>0.05);革兰染色、免疫组化两种方法检测Hp-L型的结果具有一致性(P<0.05),胃癌组与对照组的Hp-L型阳性率相比具有统计学意义(71.25%vs 14.00%,P<0.05)。胃癌组Hp-L型感染阳性率仅与淋巴结转移有关(P<0.05),Hp-L型阳性组的MIF表达阳性率高于Hp-L型阴性组(P<0.05),且Hp-L型阳性和MIF阳性呈正相关(r=0.598,P<0.05)。结论 MIF蛋白表达与胃癌的浸润转移密切相关,其机制可能与幽门螺杆菌L型(Hp-L型)感染有关。     

TLR2在胶质瘤细胞GL261的高表达及其激活后增强迁移的作用

目的探讨小鼠胶质瘤细胞系GL261主要高表达的Toll样受体（TLRs）家族成员及其在GL261细胞迁移中的作用。方法运用实时荧光定量PCR检测TLRs在GL261细胞的表达情况;GL261细胞经TLR2配体Pam3CSK4刺激后,应用Transwell迁移实验检测其对迁移能力的影响;慢病毒稳定干扰TLR2表达后,观察Pam3CSK4刺激对GL261细胞迁移能力的改变。结果GL261细胞主要高表达TLRs家族中的TLR2;Pam3CSK4激活TLR2后显著增强GL261细胞迁移能力;沉默TLR2基因表达后,Pam3CSK4促进GL261细胞迁移能力的作用消失。结论小鼠GL261胶质瘤细胞TLRs家族中主要高表达TLR2,其激活具有促进GL261细胞迁移的作用,下调TLR2可抑制该细胞的迁移。