Magnetic Resonance Imaging Characteristics of Necrotizing Meningoencephalitis in Pug Dogs

Background: The magnetic resonance imaging (MRI) characteristics of necrotizing meningoencephalitis (NME) are not well documented.
Objectives: To describe common MRI features of NME, to compare the MRI features to histopathologic findings, and to determine whether or not MRI lesions are predictive of survival time.
Animals: Eighteen Pugs with NME.
Methods: Retrospective MRI case study of Pugs identified by a search of medical records at 6 veterinary institutions. Eighteen dogs met inclusion criteria of histopathologically confirmed NME and antemortem MRI exam. MRI lesions were characterized and compared with histopathology with the kappa statistic. Survival times were compared with MRI findings by use of Mann-Whitney U -tests and Spearman's ρ.
Results: Twelve of 18 lesions were indistinctly marginated with mild parenchymal contrast enhancement. Prosencephalic (17/18) lesion distribution included the parietal (16/18), temporal (16/18), and occipital (16/18) lobes. There were cerebellar (4/18) and brainstem (3/18) lesions. Asymmetric lesions were present in both gray and white matter in all dogs. Falx cerebri shift was common (11/18), and 6 dogs had brain herniation. Leptomeningeal enhancement was present in 9/18 dogs. A moderate positive association was found between parenchymal contrast enhancement and both necrosis (κ= 0.45; P = .045) and monocytic inflammation (κ= 0.48; P = .025). Higher MRI lesion burden was correlated with longer time from disease onset to MRI ( P = .045). MRI lesion burden did not correlate to survival time.
Conclusions and Clinical Importance: Asymmetric prosencephalic grey and white matter lesions with variable contrast enhancement were consistent MRI changes in Pugs with confirmed NME. While not pathognomonic for NME, these MRI characteristics should increase confidence in a presumptive diagnosis of NME in young Pugs with acute signs of neurologic disease.     

山茱萸多糖对脑微血管内皮细胞氧化损伤的保护作用研究

采用氧化性低密度脂蛋白（ox LDL）刺激小鼠脑微血管内皮细胞bEnd.3，建立内皮细胞氧化损伤模型，通过瑞氏染色观察细胞形态变化，利用试剂盒检测细胞上清液中内皮细胞损伤相关的一氧化氮（NO）、丙二醛（MDA）、超氧化物歧化酶（SOD）和内皮素-1（ET-1）变化，采用Western blot法检测与内皮细胞凋亡相关的Bax、Bcl-2、caspase3表达变化，系统分析山茱萸多糖对小鼠脑微血管内皮细胞bEnd.3氧化损伤的保护作用。结果表明经过山茱萸多糖处理后的ox LDL刺激bEnd.3细胞形态逐渐恢复，细胞上清液中ET 1和MDA显著含量下降（P<0.01），NO和SOD含量上升（P<0.01）；凋亡抑制蛋白Bcl 2表达升高，促凋亡蛋白Bax和caspase3表达下降。说明山茱萸多糖能够在一定程度上保护ox LDL引发的内皮细胞氧化损伤。