TABLE 3.
Detection of infectivity in the CMGC and adjacent parts of the abdominal aortaa
| Donor | Sample | Mortality in bioassay | Incubation (days)
|
Estimated titer (ID50i.c./sample)b | |
|---|---|---|---|---|---|
| Range | Mean ± SE | ||||
| S1 | CMGC | 5/5 | 100–107 | 104 ± 1 | 104.1 |
| Cran. A. | 1/5 | 318 | |||
| Caud. A. | 1/5 | 156 | |||
| S2 | CMGC | 5/5 | 107–128 | 118 ± 4 | 103.1 |
| Cran. A. | 1/5 | 230 | |||
| Caud. A. | 5/5 | 120–240 | 171 ± 24 | 101.2 | |
a
Aliquots (50 μl) of homogenized CMGC and cranially (Cran.) or caudally (Caud.) adjacent artery (A.) from terminally ill donors orally challenged with 263K were inoculated i.c. into groups of five recipients. Mortality is given as number of hamsters that succumbed to infection/number challenged. Recipients similarly inoculated with CMGC from donors previously orally mock infected with normal brain homogenate showed no clinical signs of scrapie. The experiment was terminated at 370 dpi.
b
Total amount of infectivity in one equivalent of excised tissue, i.e., in the entire donor sample, calculated by applying mean incubation time to a dose-response curve.