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Query: UMLS:C0042373 (vascular disease)
 17,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present study, we report our extended data on the incidence of two types of cerebral amyloidosis (plaques and plaques associated with angiopathy) and visceral amyloidosis in late adult and aged captive rhesus monkeys (Macaca mulatta). In a total of 81 brains from animals ranging from 16 to 39 years old, beta-amyloid plaques were found in 38, 10 of which were associated with amyloid angiopathy. Brains from eight adults, 16 to 19 years, had no lesions. In aged groups, the rates were 20.8% in the 20- to 25-year group (24), 60.9% in the 26- to 31-year group (41), and 100% in the 33- to 39-year group (8). Twelve monkeys in these aged groups had an involvement of amyloidosis in either the liver, the adrenal, or the pancreatic islets, and 7 of 12 had amyloid plaques (5) and plaques associated with cerebral angiopathy (2). No neurofibrillary tangles were detected in these brain lesions. Amyloid in both plaques and cerebral angiopathy showed immunocytochemical crossreactivity with human amyloid beta (beta/A4) and precursor proteins (APP-A4), but visceral amyloid was negative. Ultrastructurally, amyloid initially appears as loose filaments in the perivascular or Disse space, and they further aggregate to produce dense interlacing bundles. Cerebral amyloid angiopathy associated with plaque appears to be a subclass of senile plaque lesions in aged monkeys as well as in aged humans, and it appears to have no pathogenetic correlation with visceral amyloidosis.
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PMID:Cerebral amyloid angiopathy and plaques, and visceral amyloidosis in aged macaques. 874 9

Inflammatory processes have been implicated in the formation of senile plaques in the cerebral cortex of patients with dementia of the Alzheimer type (DAT), since several inflammation-induced proteins are present within these plaques. The relation between inflammatory components and other amyloid beta protein (A beta)-containing lesions of the DAT brain [cerebrovascular amyloidosis (CA) and cerebellar senile plaques] is unclear. We studied the distribution of the inflammation-inducible protein intercellular adhesion molecule-1 (ICAM-1) in CA and in senile plaques of the cerebellum, using an immunohistochemical approach. We observed striking differences in ICAM-1 reactivity between the different types of A beta-containing lesions. ICAM-1 was only expressed in classic senile plaques in the granular and Purkinje cell layer of the cerebellum, and not in diffuse senile plaques of the molecular layer. Also, ICAM-1 was not associated with CA; only when the vascular amyloid extended into the neuropil (dyshoric angiopathy) was perivascular ICAM-1 reactivity observed. This is in contrast to the putative primary involvement of inflammation in the formation of cerebrocortical classic and diffuse senile plaques. Our findings indicate that ICAM-1 expression, which may be an indicator of an inflammatory reaction, is induced in the neuropil depending on the specific site of A beta production.
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PMID:Differential expression of intercellular adhesion molecule-1 (ICAM-1) in the A beta-containing lesions in brains of patients with dementia of the Alzheimer type. 878 60

A significant component of the aging process is genetically determined. Numerous theories of aging exist, many of which postulate the existence of "longevity genes." Recent advances in molecular biological and other techniques have allowed a significantly greater understanding of aging and age-related disease. This will be illustrated by four genetic and sporadic diseases: Alzheimer's disease (AD) and related disorders, transthyretin dementia, cerebral amyloid angiopathy-Icelandic type and scrapie related diseases. Alzheimer's disease (AD), the most common of this group, is the leading cause of dementia in Western countries. Recent genetic and biochemical studies have shown the involvement of at least four genes in the pathogenesis of AD. In early-onset familial AD mutations in the beta PP, S182 (presenilin 1) and STM2 (presenilin 2 or E5-1) genes have been found, while in the more common late-onset AD the presence of the apolipoprotein E4 isotype is a major risk factor. Genetic studies have also helped to elucidate the etiology of rarer cerebral amyloidoses such as the recently described Hungarian amyloidosis that is characterized by meningocerebrovascular amyloid deposition, with resultant dementia. This disease is linked to a mutation in the transthyretin gene. It is hoped that in the near future this increase in knowledge will allow the development of therapeutic approaches to slow the aging process.
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PMID:Molecular biology of brain aging and neurodegenerative disorders. 878 86

The relationship between cognitive deterioration and abnormalities detected by magnetic resonance imaging (MRI) was investigated to determine the radiological correlates of cognitive deterioration in hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D). Twenty HCHWA-D subjects (12 patients who had suffered one or more strokes and eight who had not suffered a stroke) were studied with MRI and underwent extensive neuropsychological examination. On MRI the number of focal lesions was counted, and white matter hyperintensities (WMHs) were scored semiquantitatively. A significant correlation between cognitive deterioration and WMH score and number of focal lesions was found. However, cognitive deterioration, WMH score, and the number of focal lesions all increase with age, and therefore their mutual correlation can be explained as an age effect. This study shows that cognitive deterioration in HCHWA-D is not correlated with abnormalities detected by MRI (number of focal lesions and subcortical WMHs) independently of age. Although a contribution of white matter changes and/or focal lesions, possibly in combination with age, to cognitive deterioration cannot be excluded. Cognitive deterioration in these HCHWA-D patients is probably primarily the result of chronic damage of amyloid angiopathy to the brain, to which may be superimposed cognitive impairment from focal cerebral hemorrhage or infarction.
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PMID:Hereditary cerebral hemorrhage with amyloidosis-Dutch type: better correlation of cognitive deterioration with advancing age than with number of focal lesions or white matter hyperintensities. 893 82

The systemic and cerebral accumulation of 123I-labelled serum amyloid P component (123I-SAP) was studied in patients with hereditary cerebral amyloid angiopathy-Dutch type (HCHWA-D) to determine the usefulness of 123I-SAP imaging in cerebral amyloidosis. Whole-body and SPET scintigraphic imaging was performed in two patients with HCHWA-D and four controls after the intraveous injection of 123I-SAP. Venous 123I-SAP clearance was also determined. Accumulation of the tracer was observed in the cerebral cortex of both patients, whereas no accumulation was seen in the controls. Blood clearance of radioactivity was similar in the patients and controls, suggesting that the amount of uptake of 123I-SAP in the cerebral amyloid deposits is relatively small. We believe this to be the first demonstration of cerebral amyloid deposits in vivo. Our findings indicate that 123I-SAP scintigraphy has possibilities for the diagnosis of patients with cerebral amyloid diseases, in addition to its use in patients with systemic amyloid deposition.
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PMID:Potential for imaging cerebral amyloid deposits using 123I-labelled serum amyloid P component and SPET. 897 63

The aim of the project has been to elucidate molecular events leading to amyloidosis in Hereditary Cystatin C Amyloid Angiopathy (HCCAA) patients, to enable simple diagnosis of the disease and with the ultimate goal to understand the amyloid formation process in detail, in order to develop inhibitors to the process. At the DNA level, a point mutation segregating with HCCAA was identified in the cystatin C gene on chromosome 20, after basic characterization of cDNA and gene for the wildtype protein. The mutation results in the amino acid substitution Leu-68-Gin (L68Q) and abolishes a recognition site for Alu I. This information was used to design a PCR based assay for simple and rapid mutation detection in DNA from blood samples to allow routine diagnosis of HCCAA. Studies at the protein level, allowed through E. coli expression of wildtype and L68Q mutated cystatin C genes, revealed that both protein variants effectively inhibit the cysteine proteinase cathepsin B (equilibrium constants for dissociation: 0.4 and 0.3 nM, respectively), but differ considerably in their tendency to dimerize and form aggregates. The initial dimerization of L68Q-cystatin C results in complete loss of biological activity and is highly temperature-dependent, with a rise in incubation temperature from 37 to 40 degrees C resulting in a 150% increase in dimerization rate. This result might be of clinical relevance, since medical intervention to abort febrile periods of carriers of the disease trait may reduce the in vivo formation of L68Q-cystatin C aggregates. The three-dimensional structure of normal cystatin C, crystallized in a complex with cathepsin B, was elucidated by X-ray analysis and subsequent refinement of the structure to 3.0 A resolution. Besides pinpointing the cystatin C structures resulting in efficient target enzyme inhibition, the results demonstrated that the Leu-68 residue is buried in the hydrophobic core of the protein. Studies of the three-dimensional solution structure of wildtype cystatin C by NMR spectroscopy revealed that cystatin C dimers can be formed as a result of slight, localized structural changes under conditions preceding complete defolding and denaturation of the protein. Dimers of L68Q-cystatin C are likely similar but are formed at temperatures nearly 30 degrees C lower than needed for the wildtype protein, indicating that the Leu-68-Gln substitution lowers the transition temperature for unfolding. Thus, the results presented suggest that cystatin C provides a system where decreased stability of a mutant protein correlates with its amyloidogenic nature. The NMR results furthermore imply that the hydrophobic proteinase-binding region of cystatin C is directly involved in dimer formation and that compounds designed to interact with this region could serve as inhibitors to the dimerization, and likely also the subsequent amyloid formation process, of cystatin C in HCCAA patients.
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PMID:Molecular basis for amyloidosis related to hereditary brain hemorrhage. 898 67

Smooth muscle cells cultured from leptomeningeal vessels from old dogs with amyloid-angiopathy accumulate intracellular deposits that are immunoreactive for amyloid-beta peptide (A beta). We used this cellular model in the present study to examine the influence of sera and cerebrospinal fluid on intracellular accumulation of A beta-immunoreactive deposits and on secretion of soluble A beta into culture media. We found that sera from old dogs significantly increased the percentage of A beta-positive smooth muscle cells in culture. The enhanced accumulation of A beta was associated with (a) lower secretion of A beta into media, (b) altered maturation of amyloid-beta-precursor protein (A betaPP) into A betaPP751-770 with faster electrophoretic mobility, (c) increased accumulation of C-terminal fragments of A betaPP (12-15 kD, 10kD and less), and (d) increased secretion of A betaPP into culture media. These findings suggest that age- or disease-related serum factors increase accumulation of A beta by affecting production and processing of A betaPP In contrast, cerebrospinal fluids reduced accumulation of A beta. Involvement of A beta-carrier proteins-apolipoprotein E and transthyretin-in accumulation of A beta is demonstrated. Accumulation of A beta in cultured smooth muscle cells-a model of beta-amyloidosis-may be regulated by factors that alter production and processing of A betaPP as well as the fate of soluble A beta in extracellular space.
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PMID:Accumulation of Alzheimer amyloid-beta peptide in cultured myocytes is enhanced by serum and reduced by cerebrospinal fluid. 905 40

Arterial and arteriolar amyloid-beta (A beta) deposition in hereditary cerebral hemorrhage with amyloidosis (Dutch) (HCHWA-D) and Alzheimer disease (AD) cerebral amyloid angiopathy (CAA) were studied as to morphology, extent, and association with mononuclear phagocyte system (MPS) cells using A beta, a-smooth muscle actin, and monocyte/macrophage marker (HLA-DR, CD68, CD11c, CD45) immunohistochemistry. The HCHWA-D/AD arterial/arteriolar media showed compact A beta deposits, first appearing at the media/adventitia junction, and concomitant smooth muscle loss. Only HCHWA-D CAA featured (a) severe involvement of larger arteries and (b) arterioles showing a single or double ring of radial A beta surrounding compact A beta. Radial A beta appeared to develop at the media/adventitia junction. Monocyte/macrophage marker-positive foci/cells co-localized with HCHWA-D arterial A beta. Focal HLA-DR/CD11c positivity was observed at the media/adventitia junction of AD/HCHWA-D arteries in the absence of local A beta, but not in controls. Monocyte/macrophage marker positivity co-localizing with radial A beta appeared continuous with perivascular cells and microglia clustering perivascularly. These results suggest that (a) MPS cells are topographically associated with HCHWA-D arterial A beta and radial arteriolar A beta, and (b) HLA-DR/CD11c immunoreactivity may appear at the media/adventitia junction prior to A beta. The latter finding and the assumed formation of radial A beta at the media/adventitia junction may relate to involvement of the abluminal basement membrane in CAA pathogenesis. The role of MPS cells in this process remains to be established.
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PMID:Association of vascular amyloid beta and cells of the mononuclear phagocyte system in hereditary cerebral hemorrhage with amyloidosis (Dutch) and Alzheimer disease. 905 41

Hereditary cystatin C amyloid angiopathy (HCCAA), an autosomal dominant form of cerebral amyloid angiopathy (CAA) occurring primarily in Iceland, is characterized by a variant cystatin C amyloid deposition in the walls of cerebral parenchymal and leptomeningeal vessels. Cystatin C is also found to colocalize with amyloid beta/A4 protein in cerebral vessel walls of patients with Alzheimer's disease (AD), sporadic CAA, and hereditary cerebral hemorrhage with amyloidosis, Dutch type (HCHWA-D). The abundance of cystatin C deposition in cerebral blood vessel walls suggests that cellular elements of the vessel wall itself may play a role in its deposition. Microvascular changes in the brains of HCCAA patients were investigated by single- and double-label immunohistochemistry. We found that cystatin C amyloid immunoreactivity was present not only in cerebral cortical and leptomeningeal vessels, but also in white matter parenchymal vessels. Cystatin C deposition was more prominent in the media of parenchymal vessels and in the adventitia of leptomeningeal vessels. Smooth muscle (sm) cells were few or could not be identified within vessel walls showing extensive cystatin C deposition, suggesting progressive loss of these cells as cystatin C accumulates. However, in less severely affected vessels, cystatin C was present in cells that also had the phenotype of sm, suggesting that sm cells synthesize or process cystatin C. Cystatin C immunoreactivity was in addition, detected in some neuronal cell bodies throughout the cortex in patients with HCCAA and AD-related CAA. Our results indicate that cellular components of the vessel walls may play an important role in cystatin C deposition, as they do in beta/A4 deposition in AD-related CAA. Cystatin C deposition within the vascular media and adventitia, with associated vessel wall injury as manifested by sm cell loss, represents microvascular degeneration that leads to cerebral hemorrhage.
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PMID:Microvascular degeneration in hereditary cystatin C amyloid angiopathy of the brain. 906

Hereditary cerebral hemorrhage with amyloidosis-Dutch type is caused by a mutation at codon 693 of the beta amyloid precursor protein gene. The disease is clinically characterized by strokes and dementia. In addition to cerebral plaques, cerebral amyloid angiopathy is the pathological hallmark. We investigated the correlation between radiological (white matter hyperintensities and focal lesions on magnetic resonance images) and pathological lesions (cerebrovascular amyloid angiopathy and plaques) and the apolipoprotein E genotype in patients with the disease. Twenty-five patients were studied using magnetic resonance imaging, and brain tissue from 8 patients was studied histopathologically. Neither the white matter hyperintensity scores nor the number of focal lesions on magnetic resonance images were associated with the presence of an epsilon4 allele. Nor was a correlation found between the number and type of plaques and the apolipoprotein E genotype. All patients had severe amyloid angiopathy in all cortical areas investigated. This study showed that the apolipoprotein E genotype does not modulate amyloid-related structural lesions in hereditary cerebral hemorrhage with amyloidosis of the Dutch type.
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PMID:Dutch hereditary cerebral amyloid angiopathy: structural lesions and apolipoprotein E genotype. 915 36


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