Table 2 The scoring system used to evaluate the inflammatory and repair phases of myofibre regeneration
From: Dexamethasone-induced impairment of post-injury skeletal muscle regeneration
Category | Evaluation criterion | Points assigned per criterion |
|---|---|---|
Extravasation | Absent | 0 |
Focal | 1 | |
Extensive | 2 | |
Necrosis (myofibre hypercontraction, hyalinization and fragmentation of cytoplasm, loss of striations) | Absent | 0 |
Single fibres | 1 | |
Focal | 2 | |
Extensive | 3 | |
Inflammation (all inflammatory cells, i.e., neutrophils macrophages, lymphocytes, and eosinophils) | Absent | 0 |
Minimal: ≤ 5 inflammatory cells per HPF (40x) | 1 | |
Mild: 6–10 inflammatory cells per HPF (40x) | 2 | |
Moderate: 11–20 inflammatory cells per HPF (40x) | 3 | |
Marked: > 20 inflammatory cells per HPF (40x) | 4 | |
Myogenic precursor cells (MPCs) | Absent | 0 |
Not numerous: ≤ 3 MPCs per HPF (40x) | 1 | |
Moderately numerous: 4–6 MPCs per HPF (40x) | 2 | |
Numerous: 7–12 MPCs per HPF (40x) | 3 | |
Marked numerous: > 12 MPCs per HPF (40x) | 4 | |
Myotubes | Absent | 0 |
Not numerous: < 3 myotubes per HPF (40x) | 1 | |
Moderately numerous: 3–5 myotubes per HPF (40x) | 2 | |
Numerous: > 5 myotubes per HPF (40x) | 3 | |
Young myofibres | Absent | 0 |
Not numerous: < 3 young myofibres per HPF (40x) | 1 | |
Moderately numerous: 3–5 young myofibres per HPF (40x) | 2 | |
Numerous: > 5 young myofibres per HPF (40x) | 3 |