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T Revesz

Publications and source records attributed to T Revesz.

At least 37 records · Page 2Linked to original sources
PubMed2003

Pathological inclusion bodies in tauopathies contain distinct complements of tau with three or four microtubule-binding repeat domains as demonstrated by new specific monoclonal antibodies.

Pathological inclusions containing fibrillar aggregates of hyperphosphorylated tau protein are a characteristic feature in the tauopathies, which include Alzheimer's disease, frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17), progressive supranuclear palsy, corticobasal degeneration and Pick's disease. Tau isoform composition and cellular and regional distribution as well as morphology of these inclusions vary in each disorder. Recently, several pathological missense and exon 10 splice-donor site mutations of the tau gene were identified in FTDP-17. Exon 10 codes for the second of four microtubule-binding repeat domains. The splice-site mutations result in increased inclusion of exon 10 which causes a relative increase in tau isoforms containing four microtubule-binding repeat domains over those containing three repeat domains. This could be a central aetiological mechanism in FTDP-17 and, perhaps, other related tauopathies. We have investigated changes in the ratio and distribution of three-repeat and four-repeat tau in the different tauopathies as a basis of the phenotypic range of these disorders and the selective vulnerability of different subsets of neurones. In this study, we have developed two monoclonal antibodies, RD3 and RD4 that effectively distinguish these closely related tau isoforms. These new isoform-specific antibodies are useful tools for analysing tau isoform expression and distribution as well as pathological changes in the human brain.

Animals↗
PubMed2002

The complex relationship between soluble and insoluble tau in tauopathies revealed by efficient dephosphorylation and specific antibodies.

Phosphorylated tau is deposited as insoluble inclusion bodies in the tauopathies. We have used a new efficient method to dephosphorylate tau extracted from control and tauopathy brain. In some tauopathies, including Alzheimer's disease and progressive supranuclear palsy, the pattern of insoluble tau isoforms reflected that of soluble tau. In contrast, in corticobasal degeneration, Pick's disease, and some forms of fronto-temporal dementia, specific tau isoforms were selectively sequestered into insoluble inclusion-forming tau. Therefore the overall expression of individual tau isoforms does not predict which tau isoforms are deposited in all tauopathies and different mechanisms must operate that result in the deposition of specific tau isoforms.

Amino Acid Sequence↗
PubMed2002

Analysis of tau haplotypes in Pick's disease.

Pick's disease (PiD) is characterized by the deposition of tau protein as three-repeat tau Pick bodies, whereas progressive supranuclear palsy (PSP) involves the deposition of four-repeat tau neurofibrillary tangles. PSP is associated with the tau H1 haplotype. The authors investigated a possible association between PiD and the tau H1 or H2 haplotype. There was no difference between the tau H2 haplotype or H2H2 genotype frequency in PiD cases and control subjects. No tau mutations were identified in pathologically typical cases of PiD, with antibody 12-E8-negative Pick bodies.

Aged↗
PubMed2002

Clinical features of frontotemporal dementia due to the intronic tau 10(+16) mutation.

OBJECTIVE: To describe the clinical features of nine British families with neuropathologically verified frontotemporal dementia (FTD) due to the intronic tau exon 10(+16) mutation. METHODS: Retrospective chart reviews of family members with FTD belonging to nine tau 10(+16) mutation pedigrees in whom neuropathologic examination had been carried out. APOE genotype was determined for those patients for whom DNA was available. RESULTS: The median age at onset was 50 years (range 37 to 59 years; n = 30). The median age at death was 61 years (range 42 to 72 years; n = 33). The median duration of the disease was 11 years (range 3 to 22 years; n = 25) for those who have died and is 17 years (range 15 to 23 years; n = 3) for those living. The most common presenting symptom was disinhibition (n = 23). A minority presented with frontal dysexecutive symptoms, apathy, impairment of episodic memory, or depression. All of these patients subsequently developed personality and behavioral change. Memory impairment, language deficits, ritualistic behavior, hyperphagia, and hyperorality were frequent symptoms. Parkinsonism, neuroleptic sensitivity, or primitive reflexes were present in half of the patients, where these data were available. The clinical features of ALS were absent. Neuropathologic examination of 12 patients demonstrated the hallmark tau-positive neuronal and glial inclusions. APOE genotype did not account for the considerable variation in age at onset, age at death, duration of disease, or severity of estimated brain atrophy. CONCLUSIONS: All cases fulfilled the clinical criteria for a diagnosis of FTD. Despite similar clinical phenotypes, there was considerable variation in age at onset and duration of disease both between and within families, suggesting the presence of an effect due to other genetic or environmental factors.

Adult↗
PubMed2002

Neuropathologic variation in frontotemporal dementia due to the intronic tau 10(+16) mutation.

BACKGROUND: An increasing number of recently described tau mutations show considerable clinical heterogeneity. The assessment of this phenotypic variation is of vital importance in the differential diagnosis of neurodegenerative diseases. OBJECTIVE: To assess the neuropathologic heterogeneity in a comprehensive study of 12 brains with a tau mutation at exon 10(+16) (C-to-T) splice site from 9 families. METHODS: A comprehensive neuropathologic examination has been carried out, using a wide range of tau antibodies. RESULTS: All brains showed frontotemporal atrophy of varying severity and pallor of the pigmented nuclei of the brainstem. The histologic changes were more extensive to include other cortical areas, the deep gray matter, and the white matter. The hallmark histologic lesions were the tau-positive neuronal and glial inclusions. In neurons, these ranged from typical neurofibrillary tangles through well-circumscribed inclusions to diffuse cytoplasmic staining. This tau pathology was complemented by the presence of large, abnormal achromatic neurons, neuronal loss, astrocytosis, and superficial status spongiosus. CONCLUSION: The distribution, type, and severity of these histologic abnormalities varied not only from case to case but also within the same brain. These brains with a common tau mutation raise important differential diagnostic problems: cases in the past might have been misdiagnosed as corticobasal degeneration or even atypical Pick disease, disorders with similar, if not identical, phenotypic manifestations.

Adult↗
PubMed2002

Pathological, clinical and genetic heterogeneity in progressive supranuclear palsy.

We have identified two groups of patients with clinically typical and atypical, pathologically diagnosed progressive supranuclear palsy (PSP), and investigated their genetic and molecular pathological characteristics. Those with clinically typical PSP are more likely to have the PSP susceptibility genotype and to have the deposition of PSP-type hyperphosphorylated tau protein. The clinically atypical PSP group contains a number of different clinical syndromes, including an L-dopa unresponsive bradykinetic syndrome and a clinical syndrome closely resembling idiopathic Parkinson's disease. The clinically atypical PSP group are less likely to have the PSP susceptibility genotype and often have the deposition of Alzheimer's disease paired helical filament type hyperphosphorylated tau. This study suggests that the tau PSP susceptibility genotype is most strongly associated with clinically typical PSP. Neurofibrillary tangle parkinsonian disorders, which pathologically resemble PSP but involve the deposition of Alzheimer's disease-type tau often without involvement of the tau susceptibility genotype, need to be distinguished for diagnostic and research purposes.

Aged↗
PubMed2002

Sequence analysis of tau in familial and sporadic progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a tau deposition neurodegenerative disorder which usually occurs in sporadic form and is associated with a common variant of the tau gene. Rare familial forms of PSP have been described. Recently familial frontotemporal dementia linked to chromosome 17 (FTDP-17) has been shown to be due to mutations in tau and there may be a clinical and pathological overlap between PSP and FTDP-17. In this study we have analysed the tau sequence in two small families with PSP, and a number of clinically typical and atypical sporadic cases with pathological confirmation of the diagnosis. The tau mutations described in FTDP-17 were not found in the most clinically diagnosed patients with PSP. This suggests that usually FTDP-17 and PSP, including the rare familial form of PSP, are likely to be separate conditions and that usually PSP and typical PSP-like syndromes are not due to mutations in tau.

Aged↗
PubMed2001

A novel presenilin mutation (M233V) causing very early onset Alzheimer's disease with Lewy bodies.

Presenilin 1 mutations are the major cause of autosomal dominant Alzheimer's disease: here we identify a new missense mutation causing a methionine to valine change at codon 233. This codon is homologous to a pathogenic presenilin 2 mutation with the same base change (ATG to GTG) and amino acid change (M239V). This mutation causes disease with an exceptionally early onset age (approximately 30 years) in which pathological examination shows extensive Lewy bodies as well as plaques and tangles.

Adult↗
PubMed2001

Systemic amyloid deposits in familial British dementia.

Familial British dementia (FBD) is an early onset inherited disorder that, like familial Alzheimer's disease (FAD), is characterized by progressive dementia, amyloid deposition in the brain, and neurofibrillary degeneration of limbic neurons. The primary structure of the amyloid subunit (ABri) extracted from FBD brain tissues (Vidal, R., Frangione, B., Rostagno, A., Mead, S., Revesz, T., Plant, G., and Ghiso, J. (1999) Nature 399, 776-781) is entirely different and unrelated to any previously known amyloid protein. Patients with FBD have a single nucleotide substitution at codon 267 in the BRI2 gene, resulting in an arginine replacing the stop codon and a longer open reading frame of 277 amino acids instead of 266. The ABri peptide comprises the 34 C-terminal residues of the mutated precursor ABriPP-277 and is generated via furin-like proteolytic processing. Here we report that carriers of the Stop-to-Arg mutation have a soluble form of the amyloid peptide (sABri) in the circulation with an estimated concentration in the range of 20 ng/ml, several fold higher than that of soluble Abeta. In addition, ABri species identical to those identified in the brain were also found as fibrillar components of amyloid deposits predominantly in the blood vessels of several peripheral tissues, including pancreas and myocardium. We hypothesize that the high concentration of the soluble de novo created amyloidogenic peptide and/or the insufficient tissue clearance are the main causative factors for the formation of amyloid deposits outside the brain. Thus, FBD constitutes the first documented cerebral amyloidosis associated with neurodegeneration and dementia in which the amyloid deposition is also systemic.

Adaptor Proteins, Signal Transducing↗
PubMed2001

The genetic and pathological classification of familial frontotemporal dementia.

BACKGROUND: Frontotemporal dementia (FTD) is an important cause of neurodegenerative dementia, particularly in younger patients. TAU has been identified as the gene responsible for FTD linked to chromosome 17, but it is likely that there is pathological and genetic heterogeneity among families with FTD. OBJECTIVE: To explore the genetic and pathological basis of familial FTD. DESIGN: Clinical case series with genetic analysis of each family, and pathological confirmation of diagnosis where possible. SETTING: Specialist dementia research group, particularly recruiting patients with young-onset dementia. PATIENTS: Twenty-two families with an index member with FTD, meeting Lund-Manchester criteria, and a family history of other affected members with dementia were ascertained. RESULTS: Half of the families had mutations in the TAU gene (TAU exon 10 +14, +16, and P301S), and pathological diagnoses were available in 17 of 22 families. Three main pathological diagnoses were made: FTD with neuronal and glial tau deposition, FTD with ubiquitin inclusions, and FTD with neuronal loss and spongiosis but without intracellular inclusions. No cases of familial Pick disease were identified. With the use of the pathological diagnoses, each family with FTD with neuronal and glial tau deposition had a TAU mutation, whereas TAU mutations were not identified in families in the other 2 diagnostic groups. CONCLUSIONS: This study illustrates the value of TAU sequencing in FTD and suggests that around one half of individuals with familial FTD have TAU mutations and dementia with tau pathological findings. Furthermore, these data suggest that there are at least 2 additional genes to be identified among families with autosomal dominant FTD.

Adult↗
PubMed2001

Regional distribution of amyloid-Bri deposition and its association with neurofibrillary degeneration in familial British dementia.

Familial British dementia (FBD), pathologically characterized by cerebral amyloid angiopathy (CAA), amyloid plaques, and neurofibrillary degeneration, is associated with a stop codon mutation in the BRI gene resulting in the production of an amyloidogenic fragment, amyloid-Bri (ABri). The aim of this study was to assess the distribution of ABri fibrillar and nonfibrillar lesions and their relationship to neurofibrillary pathology, astroglial and microglial response using immunohistochemistry, confocal microscopy, and immunoelectron microscopy in five cases of FBD. Abnormal tau was studied with immunoblotting. We present evidence that ABri is deposited throughout the central nervous system in blood vessels and parenchyma where both amyloid (fibrillar) and pre-amyloid (nonfibrillar) lesions are formed. Ultrastructurally amyloid lesions appear as bundles of fibrils recognized by an antibody raised against ABri, whereas Thioflavin S-negative diffuse deposits consist of amorphous electron-dense material with sparse, dispersed fibrils. In contrast to nonfibrillar lesions, fibrillar ABri is associated with a marked astrocytic and microglial response. Neurofibrillary tangles and neuropil threads occurring mainly in limbic structures, are found in areas affected by all types of ABri lesions whereas abnormal neurites are present around amyloid lesions. Immunoblotting for tau revealed a triplet electrophoretic migration pattern. Our observations confirm a close link between ABri deposition and neurodegeneration in FBD.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Primary malignant melanoma of the cerebellopontine angle.

BACKGROUND: Malignant tumors of the cerebellopontine angle are very rare, accounting for less than 1% of lesions at this site. These may be primary or secondary tumors of the temporal bone, central nervous system (CNS), or leptomeninges. Malignant melanoma is uncommon, accounting for 1.5% of all types of malignant tumors. Metastatic melanoma is a frequent cause of CNS metastasis, often with leptomeningeal spread. Primary leptomeningeal melanoma is, however, rare and even more so at the cerebellopontine angle. The prognosis for CNS malignant melanoma is generally very poor. PATIENT: The authors describe the case of a 29-year-old woman with unilateral hearing loss and facial paresis. Magnetic resonance imaging (MRI) demonstrated a mass that was thought to be an acoustic neuroma but was seen to involve the cochlea as well as the internal auditory meatus and cerebellopontine angle. The lesion was subsequently excised completely by a trans-labyrinthine approach, with facial nerve preservation, and was shown on histologic examination to be a malignant melanoma. Further comprehensive investigation did not reveal a primary extracranial site or any sign of CNS spread. The clinical features of this case, including the radiologic and histologic findings, are described, and literature concerning management is reviewed.

Adult↗
PubMed2001

Primary diffuse leptomeningeal gliomatosis simulating tuberculous meningitis.

Three patients are reported on who presented with communicating hydrocephalus due to presumed tuberculous meningitis. Subsequent clinical deterioration despite antituberculous chemotherapy prompted reassessment with FDG-PET scanning and meningeal biopsy in one case and repeat CSF cytology with special staining in the second. The third patient died and postmortem confirmed a diagnosis of primary diffuse leptomeningeal gliomatosis. In the first two patients, MRI of the entire neuraxis showed no evidence of a primary intraparenchymal tumour. These cases emphasise the need for repeated reassessment in patients with culture negative lymphocytic meningitis. In addition, this is the first report of FDG-PET scanning in leptomeningeal gliomatosis.

Adult↗
PubMed2001

A multidisciplinary team approach to skull base chordomas.

OBJECT: A multidisciplinary team devised a protocol for long-term care of patients with skull base chordomas. In this study they describe their approach. METHODS: Forty-two patients presented between 1986 and 1998 and were treated by maximum surgical cytoreduction and photon radiation therapy. Tumor volume-doubling time determined on the basis of magnetic resonance imaging, immunostaining, and cell proliferation (Ki67 labeling index [LI]) studies indicated growth rates of individual chordomas. The best outlook was associated with the greatest extent of tumor removal achieved during the first operation. There were no deaths associated with patients who underwent first-time surgery, but there was a 7.1% mortality rate associated with those who underwent subsequent operations. Cerebrospinal fluid leaks, additional cranial nerve palsies, and pharyngeal wound problems were the most difficult management problems encountered after second and subsequent surgeries. The time interval between operations was usually between 2 years and 3 years after the first surgery; very few patients required a second surgery, with a quiescent period in excess of 5 years. Life-table 5- and 10-year survival rates were 77% and 69%, respectively. CONCLUSIONS: The authors believe that this series of skull base chordomas provides new insights into the management of these lesions, particularly with regard to techniques that increase survival times and studies that aid in formulating prognoses.

Adolescent↗
PubMed2001

A multidisciplinary team approach to skull base chondrosarcomas.

OBJECT: The authors review their experience with treating skull base chondrosarcomas, which are much rarer than skull base chordomas and differ from them in prognosis and treatment. METHODS: Seventeen patients (12 male and five female patients) with histologically verified chondrosarcomas were followed up prospectively over a 12-year period. The mean age at presentation was 35.9 years. Most patients presented with cranial nerve palsies. Seven had undergone surgery prior to referral to the authors' unit. All underwent maximum surgical cytoreduction by the most direct surgical approach; only the two patients harboring the mesenchymal variant underwent radiotherapy. CONCLUSIONS: One patient died of a pulmonary embolus; the patients harboring mesenchymal chondrosarcomas died at 20 and 36 months, respectively, after treatment. Of the remaining patients, 93% were alive 5 years postsurgery and had a projected 10-year survival rate of 84% (mean survival time 9.3 years). These data emphasize the very slow progression of this tumor compared with skull base chordoma.

Adolescent↗
PubMed2000

A pathogenic presenilin-1 deletion causes abberrant Abeta 42 production in the absence of congophilic amyloid plaques.

Familial Alzheimer's disease (FAD) is frequently associated with mutations in the presenilin-1 (PS1) gene. Almost all PS1-associated FAD mutations reported so far are exchanges of single conserved amino acids and cause the increased production of the highly amyloidogenic 42-residue amyloid beta-peptide Abeta42. Here we report the identification and pathological function of an unusual FAD-associated PS1 deletion (PS1 DeltaI83/DeltaM84). This FAD mutation is associated with spastic paraparesis clinically and causes accumulation of noncongophilic Abeta-positive "cotton wool" plaques in brain parenchyma. Cerebral amyloid angiopathy due to Abeta deposition was widespread as were neurofibrillary tangles and neuropil threads, although tau-positive neurites were sparse. Although significant deposition of Abeta42 was observed, no neuritic pathology was associated with these unusual lesions. Overexpressing PS1 DeltaI83/DeltaM84 in cultured cells results in a significantly elevated level of the highly amyloidogenic 42-amino acid amyloid beta-peptide Abeta42. Moreover, functional analysis in Caenorhabditis elegans reveals reduced activity of PS1 DeltaI83/DeltaM84 in Notch signaling. Our data therefore demonstrate that a small deletion of PS proteins can pathologically affect PS function in endoproteolysis of beta-amyloid precursor protein and in Notch signaling. Therefore, the PS1 DeltaI83/DeltaM84 deletion shows a very similar biochemical/functional phenotype like all other FAD-associated PS1 or PS2 point mutations. Since increased Abeta42 production is not associated with classical senile plaque formation, these data demonstrate that amyloid plaque formation is not a prerequisite for dementia and neurodegeneration.

Alzheimer Disease↗