Table 2.
Cell densities in the 15 chronic MS lesions that mostly lacked myelin and oligodendrocytes in their center
| Lesion (MS subject) | Tissue block | Size demyelinated area in section (mm2) | Number of cells/mm2 | |||
|---|---|---|---|---|---|---|
| Oligodendrocyte precursor cells (% total) | Oligodendrocytes (% total) | Phase-bright macrophages (% total) | Total | |||
| A (94-042) | I | 9 | 19.0 ± 0.3 | 0.1 ± 0.1 | 1.1 ± 0.4 | 466.4 ± 23.2 |
| (4.1 ± 0.2) | (<0.1) | (0.2 ± 0.1) | ||||
| II | 20 | 19.0 ± 2.4 | 1.3 ± 1.1 | 3.7 ± 1.1 | 528.7 ± 56.2 | |
| (3.6 ± 0.3) | (0.2 ± 0.2) | (0.7 ± 0.2) | ||||
| B (95-095) | I | 3 | 12.2 ± 2.3 | <0.1 | 0.6 ± 0.3 | 373.5 ± 56.4 |
| (3.4 ± 0.9) | (<0.1) | (0.2 ± 0.1) | ||||
| II | 5 | 5.7 ± 0.5 | <0.1 | 0.2 ± 0.2 | 307.2 ± 20.6 | |
| (1.9 ± 0.2) | (<0.1) | (<0.1) | ||||
| III | 7 | 12.1 ± 3.9 | <0.1 | 0.7 ± 0.3 | 437.0 ± 28.2 | |
| (2.8 ± 1.1) | (<0.1) | (0.2 ± 0.1) | ||||
| IV | 18 | 9.8 ± 1.1 | 0.2 ± 0.2 | 0.2 ± 0.1 | 385.8 ± 21.2 | |
| (2.5 ± 0.2) | (<0.1) | (<0.1) | ||||
| V | 8 | 12.5 ± 3.8 | <0.1 | 0.4 ± 0.2 | 388.7 ± 16.7 | |
| (3.2 ± 0.9) | (<0.1) | (≤0.1) | ||||
| C (96-025) | I | 16 | 17.4 ± 0.8 | 0.6 ± 0.7 | 31.7 ± 9.1 | 588.4 ± 26.1 |
| (3.0 ± 0.1) | (0.1 ± 0.1) | (5.4 ± 1.8) | ||||
| II | 24 | 17.1 ± 7.0 | 1.5 ± 1.2 | 118.2 ± 13.6 | 634.9 ± 26.8 | |
| (2.8 ± 1.2) | (0.2 ± 0.2) | (18.7 ± 2.8) | ||||
| E (96-026) | 5 | 4.6 ± 0.8 | 0.1 ± 0.1 | 1.2 ± 0.3 | 704.8 ± 51.2 | |
| (0.7 ± 0.1) | (<0.1) | (0.2 ± 0.1) | ||||
| F (96-039) | I | 21 | 15.3 ± 1.1 | 0.7 ± 0.5 | 34.7 ± 18.0 | 455.7 ± 32.3 |
| (3.4 ± 0.3) | (0.2 ± 0.1) | (7.5 ± 3.4) | ||||
| II | 16 | 21.0 ± 1.2 | 0.6 ± 0.7 | 62.2 ± 21.6 | 529.4 ± 34.0 | |
| (4.0 ± 0.4) | (0.2 ± 0.1) | (11.6 ± 3.4) | ||||
| III | 17 | 34.0 ± 3.8 | <0.1 | 323.6 ± 52.1 | 795.4 ± 34.0 | |
| (4.3 ± 0.3) | (<0.1) | (40.6 ± 4.8) | ||||
| J (96-040) | 6 | 18.2 ± 2.3 | 0.2 ± 0.3 | 7.0 ± 6.3 | 524.8 ± 30.2 | |
| (3.5 ± 0.5) | (<0.1) | (1.3 ± 1.2) | ||||
| K (96-040) | 2 | 20.5 ± 2.3 | 0.6 ± 0.3 | 54.4 ± 11.7 | 587.5 ± 57.7 | |
| (3.5 ± 0.6) | (≤0.1) | (9.4 ± 2.9) | ||||
| L (96-040) | 6 | 10.5 ± 2.0 | 0.3 ± 0.2 | 21.4 ± 6.9 | 484.4 ± 23.5 | |
| (2.2 ± 0.3) | (≤0.1) | (4.4 ± 1.6) | ||||
| M (96-040) | 8 | 20.4 ± 9.2 | 0.3 ± 0.2 | 10.3 ± 3.0 | 605.9 ± 91.8 | |
| (3.3 ± 1.0) | (<0.1) | (1.6 ± 0.3) | ||||
| N (96-074) | I | 29 | 12.1 ± 2.1 | 1.7 ± 0.9 | 42.6 ± 14.2 | 467.2 ± 34.1 |
| (2.6 ± 0.3) | (0.4 ± 0.2) | (9.1 ± 2.7) | ||||
| II | 21 | 14.2 ± 0.1 | 0.5 ± 0.1 | 100.4 ± 21.4 | 495.4 ± 1.4 | |
| (2.9 ± 0.1) | (≤0.1) | (20.3 ± 4.4) | ||||
| III | 25 | 13.5 ± 0.7 | 0.3 ± 0.3 | 108.9 ± 18.2 | 565.3 ± 28.7 | |
| (2.4 ± 0.2) | (0.1 ± 0.1) | (19.2 ± 2.5) | ||||
| O (96-076) | I | 3 | 6.8 ± 1.5 | 0.1 ± 0.2 | 1.4 ± 0.1 | 380.8 ± 66.3 |
| (1.8 ± 0.6) | (<0.1) | (0.4 ± 0.1) | ||||
| II | 15 | 4.5 ± 1.1 | <0.1 | 0.4 ± 0.3 | 275.1 ± 5.0 | |
| (1.6 ± 0.5) | (<0.1) | (0.1 ± 0.1) | ||||
| III | 9 | 7.8 ± 1.1 | 0.3 ± 0.1 | 0.1 ± 0.2 | 322.4 ± 30.6 | |
| (2.4 ± 0.6) | (≤0.1) | (<0.1) | ||||
| IV | 9 | 7.8 ± 0.8 | 0.3 ± 0.2 | 0.2 ± 0.3 | 435.6 ± 53.2 | |
| (1.8 ± 0.2) | (<0.1) | (<0.1) | ||||
| Q (96-121) | Ia | 14 | 21.7 ± 4.8 | 0.8 ± 0.9 | 2.4 ± 1.6 | 656.4 ± 45.8 |
| (3.3 ± 0.6) | (0.1 ± 0.1) | (0.4 ± 0.3) | ||||
| Ib | 5 | 14.3 ± 1.5 | 1.8 ± 1.3 | 155.8 ± 40.6 | 643.5 ± 64.9 | |
| (2.2 ± 0.2) | (0.3 ± 0.2) | (24.0 ± 4.7) | ||||
| IIa | 19 | 13.3 ± 1.8 | 0.4 ± 0.7 | 1.3 ± 0.8 | 657.6 ± 37.9 | |
| (2.0 ± 0.3) | (0.1 ± 0.1) | (0.2 ± 0.1) | ||||
| IIb | 22 | 10.1 ± 2.5 | <0.1 | 130.1 ± 21.4 | 614.9 ± 50.9 | |
| (1.7 ± 0.5) | (<0.1) | (21.2 ± 4.1) | ||||
| IIIa | 23 | 15.8 ± 5.0 | <0.1 | 3.2 ± 2.3 | 722.4 ± 80.2 | |
| (2.2 ± 0.6) | (<0.1) | (0.5 ± 0.4) | ||||
| IIIb | 17 | 11.4 ± 0.9 | 0.2 ± 0.3 | 180.5 ± 16.5 | 667.6 ± 39.2 | |
| (1.7 ± 0.2) | (<0.1) | (27.2 ± 3.8) | ||||
| T (97-070) | 6 | 2.3 ± 0.7 | 0.1 ± 0.1 | 0.5 ± 0.1 | 409.7 ± 75.6 | |
| (0.6 ± 0.1) | (<0.1) | (0.1 ± 0.1) | ||||
| U (97-077) | 8 | 18.8 ± 5.2 | 0.2 ± 0.3 | 14.5 ± 1.0 | 385.1 ± 70.2 | |
| (5.1 ± 1.9) | (<0.1) | (3.9 ± 0.5) | ||||
| V (97-123) | I | 19 | 18.0 ± 1.8 | 0.1 ± 0.2 | 10.1 ± 5.9 | 408.1 ± 51.1 |
| (4.4 ± 0.2) | (<0.1) | (2.5 ± 1.5) | ||||
| II | 16 | 25.0 ± 3.3 | 0.7 ± 0.3 | 43.2 ± 5.9 | 496.0 ± 40.1 | |
| (4.8 ± 0.3) | (0.1 ± 0.1) | (9.8 ± 1.7) | ||||
Cell densities were determined in the 15 MS lesions that contained very few oligodendrocytes in their centers; border regions were excluded from the cell counts. The numbers of oligodendrocyte precursor cells, oligodendrocytes, and debris-laden macrophages (identified using phase-contrast optics; see Fig. 1) per square millimeter section were determined by analyzing the complete lesion center or by counting 6–10 semi-randomly selected microscope fields of 0.20 or 0.30 mm2; nuclei were visualized using Hoechst dye 33258, which aided the counting. Similarly, the total number of cells per square millimeter section was determined by counting the total number of Hoechst dye 33258-positive nuclei present in two to eight fields; fields containing blood vessels with perivascular cuffs (which consisted of mainly macrophages and lymphocytes) were excluded from the cell counts. Of the larger MS lesions, several tissue blocks were analyzed to determine cell densities. When lesions contained debris-laden macrophages, they were found throughout the lesions, with the exception of lesion Q (subject 96-121), in which they were only present in a sharp band (regions Ib, IIb, and IIIb) surrounding the center of the lesion (regions Ia, IIa, and IIIa). Results are expressed as mean ± SD of three to five sections.