Begara-McGorum I, González L, Simmons M, Hunter N, Houston F, Jeffrey M
Scottish Agricultural College Veterinary Science Division, Boon Loan, Midlothian, UK.
J Comp Pathol. 2002 Jul;127(1):59-68. doi: 10.1053/jcpa.2002.0558.
Detailed neuropathological examination for vacuolar lesions was performed on the brains of 42 sheep with clinical signs compatible with scrapie. The sheep were grouped according to their breed (Poll-Dorset, Cheviot, Welsh Mountain, Shetland and Suffolk), their PrP genotype at codons 136, 154 and 171 (VRQ/VRQ, VRQ/ARQ, VRQ/ARR and ARQ/ARQ) and the type of infection (experimental infection with SSBP/1, or natural disease). Twenty-two neuroanatomical sites from seven brain regions were examined for vacuolation in the neuropil and five sites at the level of the obex were examined for intraneuronal vacuolation. In 36 sheep, immunohistochemical examination for disease-specific PrP (PrP(d)) accumulation had also been performed in the same brain regions in an earlier study. The magnitude of total neuropil vacuolation was highest in the naturally affected ARQ/ARQ Suffolk sheep and lowest in the experimentally infected VRQ/VRQ Cheviot sheep and VRQ/ARR Poll-Dorset sheep. The severity of neuropil vacuolation at nine of the 22 neuroanatomical sites examined was used to generate a vacuolar lesion profile, which showed variations between the different sheep groups. These variations could be attributed to both PrP genotype and sheep breed and also possibly to scrapie agent; there was, however, considerable individual variation in lesion profile within sheep groups. All groups showed a similar ratio of neuropil vacuolation to neuronal vacuolation at the level of the obex. Although a positive correlation between neuropil vacuolation and PrP(d) deposition was generally observed, it was low except for the astrocyte-associated pattern of PrP(d) accumulation. The study suggests that vacuolar lesion profiles in sheep are affected by several factors and, by comparison with lesion profiles in mice, are of no more than limited value for discriminating between scrapie strains.
对42只出现与羊瘙痒病相符临床症状的绵羊大脑进行了空泡病变的详细神经病理学检查。这些绵羊根据其品种（无角陶赛特羊、切维厄特羊、威尔士山地羊、设得兰羊和萨福克羊）、密码子136、154和171处的朊蛋白（PrP）基因型（VRQ/VRQ、VRQ/ARQ、VRQ/ARR和ARQ/ARQ）以及感染类型（用SSBP/1进行实验性感染或自然发病）进行分组。对来自七个脑区的22个神经解剖部位进行了神经毡空泡化检查，并对闩水平的五个部位进行了神经元内空泡化检查。在36只绵羊中，早期研究还在相同脑区进行了疾病特异性PrP（PrP(d)）积累的免疫组织化学检查。总的神经毡空泡化程度在自然感染的ARQ/ARQ萨福克羊中最高，在实验感染的VRQ/VRQ切维厄特羊和VRQ/ARR无角陶赛特羊中最低。在所检查的22个神经解剖部位中的9个部位的神经毡空泡化严重程度被用于生成一个空泡病变图谱，该图谱显示了不同绵羊组之间的差异。这些差异可能归因于PrP基因型、绵羊品种，也可能归因于羊瘙痒病病原体；然而，绵羊组内病变图谱存在相当大的个体差异。所有组在闩水平的神经毡空泡化与神经元空泡化比例相似。虽然一般观察到神经毡空泡化与PrP(d)沉积之间存在正相关，但除了与星形胶质细胞相关的PrP(d)积累模式外，相关性较低。该研究表明，绵羊中的空泡病变图谱受多种因素影响，与小鼠的病变图谱相比，对于区分羊瘙痒病毒株的价值有限。
