PATHOGENESIS OF INFLUENZAL ENCEPHALITIS/ENCEPHALOPATHY

经鼻接种高致病性流感病毒(IFV)可能通过迷走神经和/或交感神经侵入延髓和胸髓的小鼠的神经传播(Vet Microbiol，2003)。将IFV接种到单侧切除的小鼠身上，表明该病毒通过迷走神经入侵脑干(Vet Pathol，2004)。用分离培养的小鼠背根神经节神经元检测IFV的跨神经传递，并与伪狂犬病病毒的结果进行比较。结果表明，IFV可通过神经细胞传播，且传播不依赖于微管的轴突运输(J Gen Virus，2005)。经鼻接种IFV后，病毒抗原、病毒基因组和脑炎在小鼠脑内持续感染不超过48天。然而，病毒并没有从脑内恢复。雷耶斯S综合征的实验性复制--急性Enc…雷耶氏综合征的原因儿童脑病多疑似IFV感染及退热治疗。采用家禽和小鼠流感脑炎/脑病模型，观察了退热药(阿司匹林和伏他林)对动物模型的影响。解热处理不影响小鼠模型(IFV经神经传播模型)，但增强了禽脑炎/脑病(IFV血源性传播模型)。Voltaren比阿司匹林更显著地放大了病变(J Vet Med Sci，2004)。鞘内免疫灭活的IFV或Aujezky病毒被接种到兔和小鼠的鞘内(接种到脑脊液中)或皮下。脑脊液中的抗体只能通过鞘内免疫才能升高。用灭活的Aujezky病毒鞘内免疫小鼠，可完全保护小鼠不受肌肉接种Aujezky病毒的临床症状、病理改变和死亡的影响。结果表明，鞘内免疫对经周围神经侵袭中枢神经系统的病毒有较好的保护作用。较少

Demonstration of neural spread of influenza virus(IFV)Intranasally inoculated highly pathogenic IFV to mice invaded medulla oblongata and thoracic cord possibly via vagal and/or sympathetic nerves (Vet Microbiol,2003). Inoculation of IFV to unilaterally vagectomized mice demonstrated the virus invades brain stem through vagal nerve(Vet Pathol,2004). Transneural transmission of IFV was examined using compartmentalized cultures of neurons from mouse dorsal root ganglia, the results were compared with those obtained using the pseudorabies virus. The results indicated that IFV can be spread transneurally and the transmission is independent of axonal transport using microtubules (J Gen Viral,2005).Persistent infection of IFVViral antigen, viral genomes and encephalitis persisted for not longer than 48 days in mice brain after intranasal inoculation of IFV. However the virus was not recovered from the brain.Experimental reproduction of Reyes' s syndromeThe cause of Reye's syndrome, acute enc … More ephalopathy of childhood is suspected of IFV infection and antipyretic treatment. The effects of antipyretics (aspirin and voltaren) on avian and murine models of influenzal encephalitis/encephalopathy were examined. Antipyretic treatment did not affect murine model (transneural spread model of IFV), whereas the treatment enhanced avian encephalitis/encephalopathy (hematogeneous spread model of IFV). Voltaren exaggerated the lesion more prominently than aspirin(J Vet Med Sci,2004).Intrathecal immunizationInactivated IFV or Aujezky virus were inoculated intrathecally (inoculation into cerebrospinal fluid) or subcutaneously in rabbits and mice. Antibody in cerebrospinal fluid was raised only by intrathecal immunization. Intrathecal immunization using inactivated Aujezky virus protected mice completely from clinical signs, pathological changes and death due to intramuscular inoculation of Aujezky virus. The results indicated the efficacy of intrathecal immunization against the viruses which invade central nervous system from invasion sites through the peripheral nerves. Less