Fig. 2
Representative photomicrographs for liver (A-D), kidney (E–H), thymus (I-L), bursa of Fabricius (M-P) and spleen (Q-T) of broiler chickens treated with different levels of SiO2@AgNPs for 35 days; H&E stain; bar = 100 μm for liver, thymus, bursa, spleen; and bar = 100 μm for kidney. Chickens from control group (A, E, I, M, Q); chicken treated with 8 mg of SiO2@AgNPs (B, F, J, N, R); chicken treated with 16 mg of SiO2@AgNPs (C, G, K, O, S); chicken treated with 20 mg of SiO2@AgNPs (D, H, L, P, T) showed: healthy normal liver tissue with no specific lesion (A); infrequent multifocal accumulations of mononuclear cells (arrows) (B); infrequent multifocal accumulations of mononuclear cells (arrow) and thickening of the periportal fibrous tissues (C); periportal fibrosis and newly formed bile ductules (D); normal histologic structure of renal tubules, renal epithelium, and glomerulus (E–F); mild to moderate degeneration and vacuolization of renal epithelium (arrow) (G); interstitial infiltration of mononuclear inflammatory cells (arrow) (H); normal histologic structure with normal intensity of medullary and cortical thymocytes and distinct corticomedullary junction (I); marked loss of cortical basophilic thymocytes (arrow) (J); marked reduction of cortical basophilic thymocytes and depletion in medullary thymocytes (arrow) (K); marked reduction of cortical basophilic thymocytes with depletion and necrosis of medullary thymocytes (arrow) (L); normal histologic structure of bursa with normal size and number of follicles and normal intensity of lymphocytic populations within medulla and cortex (M); reduced size and number of follicles, reduced medullary cell populations, and frequent cystic structure formation in some bursal follicle (arrow) (N); atrophy of the most of bursal follicles with abundance of interfollicular edema and inflammatory filtrates (astrisk) (O); interfollicular edema and inflammatory filtrates, and the most of follicles are atrophied and contain large cystic structure that contains remnants of tissue debris (astrisk) (P); normal histologic limits of white and red pulps and lymphoid follicles (Q); reduced size of lymphoid follicles (R); complete absence of lymphoid follicles with focal area of necrosis (arrow) (S); complete absence of lymphoid follicles and focal lymphoid depletion (arrow) (T)