Hematoxylin and Eosin (H&E) staining and Masson staining of myocardial and valvular tissue. A. Normal myocardial and valve tissue in control group. Magnifications, ×200; B. Diffuse inflammatory cells infiltration in myocardium (arrows). Magnification, ×100; C. Diffuse inflammatory cells infiltration in valve (arrows). Magnification, ×100; D. Anitschkow cells (arrows). Magnification, ×400; E, F. Valve fibrosis (arrow) from 24 weeks of rats. Magnification, ×100 and ×400; G. Masson staining of valve in control group at 24 weeks. Magnification, ×40; H. Masson staining of valve in RHD group at 24 weeks. Magnification, ×40.