Fig. 2
From: The breaking and making of healthy adult human skeletal muscle in vivo
Longitudinal profiles of regenerating fibres. Wide-field microscope images of single muscle fibres used for the measurement of regenerating and necrotic zones, quantified in Fig. 3. Tissue was obtained from Bergström needle biopsies of regenerating (a) and control (b) human vastus lateralis muscles. Single fibres were stained for collagen IV, desmin, macrophages (CD68) and nuclei. The regenerating muscles contained both injured and uninjured fibres (a). The injured fibres were characterised by a repeating pattern of changing diameter along the length of the fibre, which contained macrophages and desmin+ cells within the basement membrane. Note the capillaries also stained with collagen IV. Scale bar, 1000 μm. In the control samples, rare fibres demonstrated regions of uneven fibre diameter (b, area in dashed line box magnified further in b.1–4) but did not contain macrophages or desmin+ cells. Scale bar, 1000 μm for b; 200 μm for b.1–4