Semantic dementia with ubiquitin-positive tau-negative inclusion bodies.
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Three cases are reported with dementia and ubiquitin-positive but tau-negative inclusion bodies. All patients had a semantic dementia and the clinical details of two of these have been published as the first description of a selective semantic memory impairment. The original diagnosis had been of Pick's disease based on frontotemporal atrophy, but re-examination has revealed ubiquitin-positive but tau-negative inclusions as well as neurites in the frontotemporal cortices and ubiquitin-positive, intracytoplasmic inclusions in the granule cells of the dentate fascia. These inclusions are identical to those reported in association with amyotrophic lateral sclerosis (motor neuron disease), but none were seen in brainstem or spinal cord motor neurons. (+info)
Structural analysis of Pick's disease-derived and in vitro-assembled tau filaments.
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Pick's and Alzheimer's diseases are distinct neurodegenerative disorders both characterized in part by the presence of intracellular filamentous tau protein inclusions. The tight bundles of paired helical filaments (PHFs) of tau protein found in Alzheimer's disease (AD) differ from the tau filaments of Pick's disease in their morphology, distribution, and pathological structure as identified by silver impregnation. The filaments of Pick's disease are loosely arranged in pathognomonic spherical inclusions found in ballooned neurons, whereas the tau pathology of AD is classically described as a triad of neuropil threads, neurofibrillary tangles, and dystrophic neurites surrounding and invading plaques. In this study we used the high-resolution technique of scanning transmission electron microscopy to characterize and compare the filaments found in Pick's disease with those found in AD. In addition, we determined the mass/nm length and density of arachidonic acid-induced in vitro-assembled filaments. Three morphologically distinct populations of Pick's filaments were identified but each was indistinguishable from AD-PHFs in mass/nm length and density. Filaments assembled in vitro from single isoforms were similar in mass/nm length, but less dense than AD-PHFs and Pick's disease filaments. Finally, we provide clear structural evidence that a PHF, whether found in disease or assembled in vitro, is composed of two distinct intertwined filaments. (+info)
Classic Pick's disease type with ubiquitin-positive and tau-negative inclusions: case report.
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We report on a patient presenting Pick's disease similar to the one reported by Pick in 1892, with ubiquitin-positive and tau-negative inclusions. His diagnosis was made on the basis of clinical (language disturbance and behavioural disorders), neuropsychological (progressive aphasia of the expression type and late mutism), neuroimaging with magnetic resonance (bilateral frontal and temporal lobes atrophy) and brain single photon emission computed tomography (frontal and temporal lobes hypoperfusion) studies. Macroscopic examination showed atrophy on the frontal and temporal lobes. The left hippocampus displayed a major circumscribed atrophy. The diagnostic confirmation was made by the neuropathological findings of the autopsy that showed neuronal loss with gliosis of the adjacent white matter and apearance of status spongiosus in the middle frontal and especially in the upper temporal lobes. There were also neuronal swelling (ballooned cell) and argyrophilic inclusions (Pick's bodies) in the left and right hippocampi. Anti-ubiquitin reaction tested positive and anti-tau tested negative. (+info)
Proton chemical shift imaging in pick complex.
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BACKGROUND AND PURPOSE: Pick complex (PC) is the name given to a group of diseases comprising Pick disease and its variations, all of which have a large degree of pathologic and clinical overlap. Because of this overlap, the observation of neuropathologic changes in vivo is difficult, although these changes play important roles in the criteria used for classification. The purpose of this study was to evaluate changes in brain metabolism in PC with proton chemical shift imaging ((1)H-CSI). METHODS: Nine patients with PC (three each with frontotemporal dementia, corticobasal degeneration [CBD], and primary progressive aphasia [PPA]) and five healthy subjects underwent (1)H-CSI. Volumes of interest were selected at the level of the basal ganglia by using a spin-echo sequence (TR/TE, 2000/13). Peak areas and ratios of N-acetylaspartate (NAA), creatine (Cr), and choline (Cho) were calculated in voxels in the basal ganglia and perisylvian regions. RESULTS: Reduced NAA/Cho ratios were observed in the right basal ganglia of the patients with PC. In patients with CBD or PPA, low NAA/Cr values were detected in the right perisylvian region. CONCLUSION: In PC, (1)H-CSI decreased NAA values in a wide area. Significantly reduced NAA levels in the right hemisphere in patients with PC suggests a neurodegenerative change and may reflect cases in which the right hemisphere is dominantly affected, compared with the left hemisphere. (1)H-CSI provided information that could not be obtained with other imaging techniques. Thus, (1)H-CSI may provide useful information for understanding the pathologic process underlying PC. (+info)
Biochemical analysis of tau proteins in argyrophilic grain disease, Alzheimer's disease, and Pick's disease : a comparative study.
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Although argyrophilic grain disease is characterized histopathologically by tau-positive lesions known as argyrophilic grains located predominantly in limbic brain regions in the absence of other diagnostic neuropathologies, the biochemical correlates of argyrophilic grains in gray and white matter have not been reported. Thus, we analyzed insoluble (pathological) tau proteins in five argyrophilic grain disease brains in comparison with those seen in Alzheimer's disease and Pick's disease. Analyses of separately dissected gray and white matter samples from various cortical regions revealed that pathological tau in argyrophilic grain disease was confined primarily to mediotemporal neocortical gray and adjacent white matter, and also to the allocortex, amygdala, and hippocampus. The amounts of sarcosyl-insoluble tau in all five cases were substantially lower than in Alzheimer's disease and Pick's disease, but the amounts of sarcosyl-insoluble tau in white matter were higher or comparable to that detected in gray matter from the same region, which distinguishes argyrophilic grain disease from Alzheimer's disease. The banding patterns of tau isoforms in argyrophilic grain disease varied: in three cases they were similar to Alzheimer's disease, but in two other cases, 4 microtubule binding repeat (4R) tau predominated, which distinguishes argyrophilic grain disease from classical Pick's disease. The differences between these three diseases were re-enforced by the predominance of straight tau filaments from argyrophilic grain disease brains. Thus, we conclude that argyrophilic grain disease is a distinct tauopathy characterized by prominent accumulation of argyrophilic grains in limbic brain regions in association with the characteristic tau biochemical and ultrastructural profile reported here. (+info)
Severity of gliosis in Pick's disease and frontotemporal lobar degeneration: tau-positive glia differentiate these disorders.
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Frontotemporal dementia is a term used to characterize diverse neuropathological conditions that can present with the same clinical phenotype. Five different neuropathologies underlie this disorder. However, consistent frontal and/or temporal neuronal loss and gliosis characterize all cases, the majority having no obvious pathological inclusions. Because neuronal loss and gliosis are consistent features across all cases, the present study aimed to determine the relationship between neuronal loss, gliosis and, for cases with abnormal tau inclusions, intracellular tau deposition. Formalin-fixed brain specimens from sporadic cases with frontotemporal dementia (eight with tau-positive Pick bodies, five with frontotemporal lobar degeneration without inclusions) were compared with those from non-diseased controls (n = 5). Brain specimens were cut into 3 mm coronal slices for evaluation and tissue samples from the superior frontal gyrus were taken for microscopic analysis. Immuno histochemistry for glia-specific proteins (astrocytic glial fibrillary acidic protein and microglial major histocompatibility complex II) and different tau epitopes was performed on 50 microm free-floating sections. Gross patterns of brain atrophy were analysed and upper and lower layer pyramidal neurons and glial cell numbers were quantified. A disease severity scheme was devised using the degree of gross macroscopic frontal and temporal atrophy to establish the relationship between the gliosis and neurodegeneration. In this small sample, the patterns of gross atrophy could be grouped reliably into four stages of severity. These stages were the same across disease groups and correlated with volume- corrected pyramidal neuron densities. In cases with Pick bodies, disease stage also correlated with duration, providing further evidence that these stages represent the progression of degeneration in this limited sample. Whereas there were, on average, many more reactive astrocytes in the cases with Pick bodies than in those with frontotemporal lobar atrophy, there was significant overlap between cases in the degree of astrocytosis. However, a large proportion of the astrocytes in Pick's disease displayed phosphorylated tau immunoreactivity, whereas no tau-positive astrocytes were found in frontotemporal lobar degeneration. The pattern and degree of microglia activation were similar in all the dementia cases analysed, with considerably more activated microglia accumulating in white matter. In this small sample, the abundance of white matter microglia at early disease stages suggests a prominent role for this cell type in the neurodegenerative process. In frontotemporal lobar degeneration, a significant proportion of the activated white matter microglia were tau-2-immunoreactive, suggesting direct involvement in axonal degeneration, possibly via immune processes. (+info)
Alterations of muscarinic acetylcholine receptors in atypical Pick's disease without Pick bodies.
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BACKGROUND: Atypical Pick's disease without Pick bodies is a type of frontotemporal dementia characterised by semantic dementia and temporal dominant lobar atrophy with ubiquitinopathy. No neurochemical analyses have ever been reported in this condition. OBJECTIVE: To investigate muscarinic acetylcholine receptors (mAchR) and their subtypes (M1-M4) in atypical Pick's disease. SUBJECTS: Five cases of atypical Pick's disease were studied. They were compared with nine control cases, 11 cases of Alzheimer's disease, and seven cases of dementia with Lewy bodies. METHODS: A [(3)H]quinuclidinyl benzilate (QNB) binding assay and an immunoprecipitation assay using subtype specific antisera were used. RESULTS: The total amount of mAchR in the temporal cortex was lower in atypical Pick's disease than in controls or Alzheimer's disease cases, but there were no significant differences between the three groups in the frontal cortex. In the temporal cortex, there was a smaller proportion of M1 receptors in atypical Pick's disease than in the controls or in the patients with Alzheimer's disease and dementia with Lewy bodies. In contrast, the proportion of M2 receptor was higher in atypical Pick's disease than in the other three groups. CONCLUSIONS: Depletion of postsynaptic cholinoreceptive neurones in the temporal cortex is more severe in atypical Pick's disease than in other neurodegenerative dementing disorders. (+info)
Nitration of tau protein is linked to neurodegeneration in tauopathies.
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Oxidative and nitrative injury is implicated in the pathogenesis of Alzheimer's disease (AD) and Down syndrome (DS), but no direct evidence links this type of injury to the formation of neurofibrillary tau lesions. To address this, we generated a monoclonal antibody (mAb), n847, which recognizes nitrated tau and alpha-synuclein. n847 detected nitrated tau in the insoluble fraction of AD, corticobasal degeneration (CBD), and Pick's disease (PiD) brains by Western blots. Immunohistochemistry (IHC) showed that n847 labeled neurons in the hippocampus and neocortex of AD and DS brains. Double-label immunofluorescence with n847 and an anti-tau antibody revealed partial co-localization of tau and n847 positive tangles, while n847 immunofluorescence and Thioflavin-S double-staining showed that a subset of n847-labeled neurons were Thioflavin-S-positive. In addition, immuno-electron microscopy revealed that tau-positive filaments in tangle-bearing neurons were also labeled by n847 and IHC of other tauopathies showed that some of glial and neuronal tau pathologies in CBD, progressive supranuclear palsy, PiD, and frontotemporal dementia with parkinsonism linked to chromosome 17 also were n847-positive. Finally, nitrated and Thioflavin-S-positive tau aggregates were generated in a oligodendrocytic cell line after treatment with peroxynitrite. Taken together, these findings imply that nitrative injury is directly linked to the formation of filamentous tau inclusions. (+info)