RESUMO
BACKGROUND: No method for the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease (sCJD) has been established except for pathologic examination. OBJECTIVE: To identify a reliable marker for the clinical diagnosis of MM2-type sCJD. METHODS: CSF, EEG, and neuroimaging studies were performed in eight patients with MM2-type sCJD confirmed by neuropathologic, genetic, and western blot analyses. RESULTS: The eight cases were pathologically classified into the cortical (n = 2), thalamic (n = 5), and combined (corticothalamic) (n = 1) forms. The cortical form was characterized by late-onset, slowly progressive dementia, cortical hyperintensity signals on diffusion-weighted imaging (DWI) of brain, and elevated levels of CSF 14-3-3 protein. The thalamic form showed various neurologic manifestations including dementia, ataxia, and pyramidal and extrapyramidal signs with onset at various ages and relatively long disease duration. Characteristic EEG and MRI abnormalities were almost absent. However, all four patients examined with cerebral blood flow (CBF) study using SPECT showed reduction of the CBF in the thalamus as well as the cerebral cortex. The combined form had features of both the cortical and the thalamic forms, showing cortical hyperintensity signals on DWI and hypometabolism of the thalamus on [18F]2-fluoro-2-deoxy-d-glucose PET. CONCLUSION: For the clinical diagnosis of MM2-type sporadic Creutzfeldt-Jakob disease, cortical hyperintensity signals on diffusion-weighted MRI are useful for the cortical form and thalamic hypoperfusion or hypometabolism on cerebral blood flow SPECT or [18F]2-fluoro-2-deoxy-d-glucose PET for the thalamic form.
Assuntos
Síndrome de Creutzfeldt-Jakob/diagnóstico , Proteínas 14-3-3/líquido cefalorraquidiano , Idade de Início , Idoso , Doença de Alzheimer/diagnóstico , Biomarcadores , Western Blotting , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/patologia , Córtex Cerebral/fisiopatologia , Proteínas do Líquido Cefalorraquidiano/análise , Circulação Cerebrovascular , Síndrome de Creutzfeldt-Jakob/líquido cefalorraquidiano , Síndrome de Creutzfeldt-Jakob/classificação , Síndrome de Creutzfeldt-Jakob/epidemiologia , Síndrome de Creutzfeldt-Jakob/genética , Síndrome de Creutzfeldt-Jakob/fisiopatologia , Diagnóstico Diferencial , Imagem de Difusão por Ressonância Magnética , Eletroencefalografia , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Tomografia por Emissão de Pósitrons , Príons/genética , Paralisia Supranuclear Progressiva/diagnóstico , Tálamo/irrigação sanguínea , Tálamo/diagnóstico por imagem , Tálamo/patologia , Tomografia Computadorizada de Emissão de Fóton ÚnicoRESUMO
Maackia amurensis haemagglutinin (MAH) is a leguminous lectin which preferentially binds to a cluster of sialylated O-linked carbohydrate chains (Konami Y, Yamamoto K. Osawa T, Irimura T (1994) FEBS Lett 342:334-38). In the present study a 950 bp cDNA clone encoding MAH was isolated from a cDNA library constructed from germinated Maackia amurensis seeds. From the nucleotide sequence, MAH was predicted to consist of 285 amino acid residues containing a signal peptide of 29 amino acids. The results also confirmed our previous findings from the amino acid sequence analysis, which indicated that two highly conserved amino acid residues in all other well-known leguminous lectins were replaced in MAH. These residues were lysine-105 and aspartic acid-135. The corresponding amino acid residues in other leguminous lectins were glycine and asparagine, respectively. These differences were due to the presence of nucleotides AAA and GAT in place of AAT/C and GGA/T.