Search

Background Bone marrow transplantation (BMT) is commonly used in experimental studies to investigate the contribution of BM-derived circulating cells to different disease processes. During studies investigating the cardiac response to acute myocardial infarction (MI) induced by permanent coronary ligation in mice that had previously undergone BMT, we found that BMT itself affects the remodelling response. Methods and results Compared to matched naive mice, animals that had previously undergone BMT developed significantly less post-MI adverse remodelling, infarct thinning and contractile dysfunction as assessed by serial magnetic resonance imaging. Cardiac rupture in male mice was prevented. Histological analysis showed that the infarcts of mice that had undergone BMT had a significantly higher number of inflammatory cells, surviving cardiomyocytes and neovessels than control mice, as well as evidence of significant haemosiderin deposition. Flow cytometric and histological analyses demonstrated a higher number of alternatively activated (M2) macrophages in myocardium of the BMT group compared to control animals even before MI, and this increased further in the infarcts of the BMT mice after MI. Conclusions The process of BMT itself substantially alters tissue macrophage phenotype and the subsequent response to acute MI. An increase in alternatively activated macrophages in this setting appears to enhance cardiac recovery after MI. [ABSTRACT FROM AUTHOR]

Abstract: Hexagonal boron nitride (hBN) powder was fabricated prepared by the spray drying and calcining–nitriding technology. The effects of nitrided temperature on the phases, morphology and particle size distribution of hBN powder, were investigated. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Fourier transformed infrared spectrum, ultraviolet–visible (UV–vis) spectrum and photoluminescence (PL) spectrum. UV–vis spectrum revealed that the product had one obvious band gap (4.7eV) and PL spectrum showed that it had a visible emission at 457nm (λ ex=230nm). FESEM image indicated that the particle size of the synthesized hBN was mainly in the range of 0.5–1.5μm in diameter, and 50–150nm in thickness. The high-energy ball-milling process following 900°C calcining process was very helpful to obtain fully crystallized hBN at lower temperature. [Copyright &y& Elsevier]