Figure 3
From: Histoarchitecture of the fibrillary matrix of human fetal posterior tibial tendons
Collagen molecular architecture and cells distribution. (A,B) note reddish-orange birefringent collagen fibers analyzed by picrosirius under polarization in Group I (n = 5) human fetal tendons with a fragmented and disarranged pattern. In contrast, the collagen fibers stay in parallel or linear orientation in Group II (n = 4) tendons, (C,D) (arrows). (E,I,M) fluorescence microscopy by DAPI staining to identify the cell nucleus, with a large amount of cells with diffuse pattern in Group I tendons and in (G,K,O) demonstrate Group II tendon specimens with uniform and linear arrangement of the nuclei (arrows). (F,J,N) Immunostaining to collagen I, III and V visualized under fluorescence microscopy of Group I, demonstrating the reticulated pattern of collagen types. In contrast, (H,L,P) uniform green fluorescence and parallel orientation of collagen type I, III and V fibers in all areas of Group II tendons. (Q) A graphic representation of the total number of cells in Group I compared to Group II tendons (23.35 ± 1.74 vs. 16.07 ± 0.77; p < 0.04). A graphic representation of the amount (percentage of total tendon area, mean and standard deviation) of collagen I (51.40 ± 1.71 vs. 31.11 ± 1.74; p < 0.016) (R), collagen III (31.19 ± 2.10 vs. 17.02 ± 1.37; p < 0.015) (S) and collagen V (12.52 ± 0.76 vs. 4.392 ± 0.76; p < 0.016) (T) in the Group I in compared to Group II tendons. GraphPad Prism 6.0 software: Mann Whitney U test; P-values < 0.05 were considered significant.
