RESUMO
OBJECTIVE: The production of neurotoxic ß-amyloid and the formation of hyperphosphorylated tau are thought to be critical steps contributing to the neuropathological mechanisms in Alzheimer's disease (AD). However, there remains an argument as to their importance in the onset of AD. Recent studies have shown that axonopathy is considered as an early stage of AD. However, the exact relationship between axonopathy and the origin and development of classic neuropathological changes such as senile plaques (SPs) and neurofibrillary tangles (NFTs) is unclear. The present study aimed to investigate this relationship. METHODS: Postmortem tracing, combined with the immunohistochemical or immunofluorescence staining, was used to detect axonopathy and the formation of SPs and NFTs. RESULTS: Axonal leakage-a novel type of axonopathy, was usually accompanied with the extensive swollen axons and varicosities, and was associated with the origin and development of Aß plaques and hyperphosphorylated tau in the brains of AD patients. CONCLUSION: Axonopathy, particularly axonal leakage, might be a key event in the initiation of the neuropathological processes in AD.
Assuntos
Doença de Alzheimer/patologia , Axônios/patologia , Encéfalo/patologia , Placa Amiloide/patologia , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/metabolismo , Transporte Axonal , Axônios/metabolismo , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Estudos de Casos e Controles , Feminino , Lobo Frontal/metabolismo , Lobo Frontal/patologia , Lobo Frontal/ultraestrutura , Hipocampo/metabolismo , Hipocampo/patologia , Hipocampo/ultraestrutura , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Técnicas de Rastreamento Neuroanatômico/métodos , Emaranhados Neurofibrilares/metabolismo , Emaranhados Neurofibrilares/patologia , Mudanças Depois da Morte , Valores de Referência , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Lobo Temporal/ultraestrutura , Bancos de TecidosRESUMO
OBJECTIVE: To study the relationships of Cyclin D1 expression with the posttraumatic intervals (PTI) following the cerebra, brainstem or cerebella contusion in human. METHODS: 88 cases of brain contusions of the closed head injury were investigated with pathological and Cyclin D1 immunohistochemistry methods. The results were analyzed by image analysis technique (IAT). RESULTS: The immunoreactivity of Cyclin D1 was almost disappeared in the core cells of the brain contusion. Cyclin D1-positive cells started to increase in the boundary of the brain contusion in the 1h group. Cyclin D1-positive cells were increased significantly in the 3 h-30 d groups and maintained at a high level in the boundary of the brain contusion of those groups. It is suggested that the Cyclin D1-positive cells were primarily origin from microglia and other glia. A few neurons expressed Cyclin D1. CONCLUSION: Cyclin D1 can express in several kinds of brain cells following the contusion, especially in the glia cells. Cyclin D1-positive cells were increased obviously and rapidly after injury, so it could be used as a reference marker for early stage brain injury.
