Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042373 (vascular disease)
 17,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To better understand the characteristics of amyloid deposition in the choroid plexus, we examined autopsied brain by routine histology, immunohistochemistry, and electron microscopy in three group of patients: primary systemic amyloidosis (n = 7), cerebral amyloid angiopathy (CAA, n = 6), and controls (n = 3). Three of the CAA patients had Alzheimer's disease. Congophilic, birefringent amyloid deposits of the choroid plexus were seen in six of the seven cases of systemic light chain amyloidosis. Immunohistochemistry revealed that the deposited amyloids had reactivity for immunoglobulin light chain and amyloid P component. Accumulation of macrophages labeled with monoclonal antibodies against CD 68 and major histocompatibility complex class II antigens were observed around the massive amyloid deposits. The presence of approximately 10 nm amyloid fibrils along the epithelial basement membrane as well as in the vascular walls was ascertained by electron microscopy. In CAA, Congo red-positive amyloid deposits were consistently present in meningeal blood vessels and were often found in senile plaques of the cerebral parenchyma; congophilic amyloid deposits were absent in the choroid plexus. Choroid plexus epithelial cells exhibited immunostaining for beta amyloid precursor protein (APP) with N-terminal- and C-terminal-specific antibodies; in particular, consistent staining was obtained for the latter antibody. Immunoreactivity for amyloid beta protein (A beta) with monoclonal antibodies (6E10, 4G8) was often found in choroid plexus epithelial cells. These findings suggest that amyloid deposition of the choroid plexus depends on the major component protein in amyloidosis, and that the choroid plexus may produce APP and A beta protein although A beta amyloidosis is not evident in the choroid plexus.
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PMID:Human choroid plexus is an uniquely involved area of the brain in amyloidosis: a histochemical, immunohistochemical and ultrastructural study. 917 87

Smooth muscle cells (SMCs) isolated from amyloid-angiopathy affected brain vessels accumulate intracellularly amyloid-beta peptide (A beta). Now we demonstrate that accumulation of A beta in SMCs can be reduced by factors secreted by macrophages - IL-1alpha, IL-6, TNF-alpha, TGF-beta1 or PGE2 - probably by stimulating the non-amyloidogenic processing of A beta precursor protein (PP). It is suggested that brain macrophages may regulate A betaPP/A beta metabolism under physiological conditions and prevent beta-amyloidosis. The disturbance of this regulatory function of brain macrophages may result in excessive production and accumulation of A beta.
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PMID:Factors produced by activated macrophages reduce accumulation of Alzheimer's beta-amyloid protein in vascular smooth muscle cells. 923 43

Current evidence from genetic and epidemiological studies supports the view that Alzheimer's disease (AD) is a heterogeneous disorder. While the disease is pathologically defined by the presence of specified lesions in form of amyloid plaques and neurofibrillary tangles within the parenchyma, other features of pathology are often either neglected or considered coincidental. Our studies suggest that cerebrovascular pathology is inherently part of the disorder, which could be an important factor in a cause or effect manner. We have recently identified subjects having died with severe amyloid beta (A beta) protein cerebral amyloid angiopathy (CAA) in the absence of a profound Alzheimer pathology. These subjects, diagnosed with dementia had a late onset disease and were found at autopsy to exhibit severe CAA but paucity of typical AD changes. Immunocytochemical studies showed numerous microvascular abnormalities as well as characteristic degeneration of the vascular smooth muscle in both surface and intracortical vessels. The pathology was also characterized by occasional intracerebral hemorrhages and multiple infarcts. Further assessment of the abnormalities and amyloid infiltrated cerebral vessels with antibodies to the carboxyl terminus of A beta indicated that the longer, more pathogenic form of A beta(1-42) was found to be highly associated with intracerebral hemorrhages. Our observations suggest that these mild AD cases with a predominantly vascular pathology are variants of AD and bear resemblance to the familial Dutch and Flemish versions of cerebral amyloidosis. We propose that AD is a group of diseases with a variable pathology analogous to the prion diseases, in which a vascular variant also exists.
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PMID:Amyloid-beta protein angiopathies masquerading as Alzheimer's disease? 932 10

Cerebral amyloid angiopathy (CAA) is a significant risk factor for hemorrhagic stroke in the elderly, and occurs as a sporadic disorder, as a frequent component of Alzheimer's disease, and in several rare, hereditary conditions. The most common type of amyloid found in the vasculature of the brain is beta-amyloid (A beta), the same peptide that occurs in senile plaques. A paucity of animal models has hindered the experimental analysis of CAA. Several transgenic mouse models of cerebral beta-amyloidosis have now been reported, but only one appears to develop significant cerebrovascular amyloid. However, well-characterized models of naturally occurring CAA, particularly aged dogs and non-human primates, have contributed unique insights into the biology of vascular amyloid in recent years. Some non-human primate species have a predilection for developing CAA; the squirrel monkey (Saimiri sciureus), for example, is particularly likely to manifest beta-amyloid deposition in the cerebral blood vessels with age, whereas the rhesus monkey (Macaca mulatta) develops more abundant parenchymal amyloid. These animals have been used to test in vivo beta-amyloid labeling strategies with monoclonal antibodies and radiolabeled A beta. Species-differences in the predominant site of A beta deposition also can be exploited to evaluate factors that direct amyloid selectively to a particular tissue compartment of the brain. For example, the cysteine protease inhibitor, cystatin C, in squirrel monkeys has an amino acid substitution that is similar to the mutant substitution found in some humans with a hereditary form of cystatin C amyloid angiopathy, possibly explaining the predisposition of squirrel monkeys to CAA. The existing animal models have shown considerable utility in deciphering the pathobiology of CAA, and in testing strategies that could be used to diagnose and treat this disorder in humans.
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PMID:Animal models of cerebral beta-amyloid angiopathy. 937 51

To investigate the relationship between cerebral amyloid angiopathy (CAA) and cystatin C, we studied five CAA patients on whose cerebral blood vessels colocalization of cystatin C and beta-protein was recognized immunohistochemically. One patient was suspected as familial CAA and the other patients were sporadic cases. Two patients had low concentration of cystatin C in their cerebrospinal fluid (CSF) as we have previously reported in CAA patients. Enzyme-linked immunosorbent assay (ELISA) revealed that cystatin C and beta-protein have been included at the ratio of about 1:100 in the crude amyloid fibrils of one patient. Using a monoclonal antibody (MAb) against cystatin C, we performed affinity chromatography and immunoblotting on her amyloid fibril fraction. Eluate showed a band with a mol wt of 14,000 and the N-terminal 14 amino acid residues of 14-kDa protein were identical with that of cystatin C. This molecular weight is not identical to that of the truncated form of cystatin C deposited in hereditary cerebral hemorrhage with amyloidosis in Iceland (HCHWA-I), but that of normal cystatin C. DNA sequence analysis of five patients showed no point mutations in the cystatin C gene. Cystatin C and beta-protein colocalization, which was recognized in amyloid lesions of CAA, suggests that cystatin C deposition may be related to beta-protein deposition. We hypothesize that cystatin C deposition in sporadic cerebral amyloid angiopathy with cystatin C deposition (SCCAA) involves a different mechanism from that in HCHWA-I, which may be related to low CSF concentration of cystatin C without amino acid substitutions.
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PMID:No mutations in cystatin C gene in cerebral amyloid angiopathy with cystatin C deposition. 949 77

Cerebral amyloid angiopathy affects the cerebral vasculature selectively, and there is no systemic amyloidosis. Amyloid is deposited in small and medium-sized vessels of the cortex and leptomeninges. Cerebral amyloid angiopathy is a common cause of spontaneous lobar haemorrhage in elderly patients. However, cerebral amyloid angiopathy may have atypical clinical and radiological presentations. We report on five patients (three males and two females, aged 43-77 years) with histologically verified cerebral amyloid angiopathy. One patient experienced an acute headache attack and classical lobar haemorrhage. The other patients had various neurological symptoms and signs, such as seizure, disturbed vision, pareses, aphasia, and dementia that were initially diagnosed as cerebral infarction or tumour. Two patients with cerebral amyloid angiopathy and granulomatous angiitis responded to immunosuppressive treatment.
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PMID:[Cerebral amyloid angiopathy]. 976 Aug 54

A variety of signs and symptoms constituting the uraemic syndrome may be related to the retention and accumulation of uraemic toxins. Several identified (and yet unidentified) uraemic toxins of low molecular weight are removed at least in part by dialysis therapy resulting in marked improvement of multiple organ dysfunctions and clinical symptoms. However, many abnormalities persist due to the high protein binding of several uraemic toxins or their high molecular weight associated with inadequate dialysis clearance. Moreover, carbamoylation of amino acids and proteins in uraemia as well as metabolic acidosis contribute to the functional and metabolic abnormalities of the uraemic state. Uraemia interferes with the function of polymor-phonuclear leukocytes by deranging their cellular biochemistry and biology. P-cresol and several newly identified granulocyte inhibitory proteins are responsible for reduced chemotaxis, oxidative activity, intracellular killing of bacteria, and glucose consumption by polymorphonuclear leukocytes. Hyperhomocysteinaemia is an independent risk factor for vascular disease in end-stage renal disease patients. Uraemic toxins interfere with calcitriol synthesis and concentration or activity of the calcitriol receptor. Advanced glycolysation end-products (AGEs) accumulate as a result of impaired renal excretion. AGE peptides may represent a modern-day version of "middle molecule" toxicity or uraemia. Of potential clinical importance are pentosidine-, imidazolone- and carboxymethyllysine-modifications of beta 2-microglobulin with respect to the development of uraemia associated amyloidosis. Several uraemic toxins also affect nitric oxide pathway. Particularly, dimethyl-L-arginine (ADMA) is a potent inhibitor of nitric oxide synthesis. Parathyroid hormone satisfies the strict criteria of an uraemic toxin. Many uraemic symptoms can be attributed to the excess of parathyroid hormone in patients with chronic renal failure. Finally, recent investigations indicate, that one or more dialyzable uraemic toxin(s) suppress(es) appetite and may contribute to malnutrition in uraemia.
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PMID:Genesis of the uraemic syndrome: role of uraemic toxins. 978 69

Advanced glycation endproducts (AGEs) accumulate in uraemia as a consequence of diminished clearance of low molecular weight forms which retain their reactivity and may subsequently combine with circulating and tissue macromolecules. Successful renal transplantation is the only form of renal replacement therapy which effectively clears these circulating AGEs; both haemodialysis and peritoneal dialysis are comparatively ineffective although high-flux haemodialysis confers some benefits. De novo AGE formation may be accelerated in uraemia due to carbonyl and oxidative stress leading to further accumulation. The consequences for the patient with chronic renal failure may be acceleration of vascular disease, renal failure progression and dialysis-related amyloidosis. Accelerated peritoneal AGE formation as a consequence of treatment with peritoneal dialysis fluids may be detrimental to peritoneal membrane function but does not appear to contribute to systemic elevation of AGEs.
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PMID:The pathogenesis and consequences of AGE formation in uraemia and its treatment. 984 90

In hereditary cystatin C amyloid angiopathy (HCCAA), presence of the Leu68 --> Gln substitution in cystatin C is coupled to a decreased concentration of this major cysteine proteinase inhibitor in cerebrospinal fluid and leads to its amyloid deposition in the brain. We established a high-yield expression system for L68Q cystatin C in Escherichia coli resulting in inclusion body accumulation at a level of 40% of the total cellular protein. Refolding of protein from purified inclusion bodies yielded a pure, almost completely monomeric and active inhibitor. CD and NMR spectroscopy demonstrated that so produced L68Q cystatin C is folded, conformationally homogeneous, and structurally very similar to wild-type cystatin C. Incubation at pH 7.0-5.5 caused the cystatin C variant to dimerize rapidly. The molecular form present at pH 6.0 displayed a slightly increased amount of hydrophobic parts on the surface as measured by 1-anilinonaphthalene-8-sulfonic acid (ANS) binding. NMR results showed that the dimer has a structure similar to that of the wild-type cystatin C dimer formed as a result of slight denaturation. Under more acidic conditions, at pH 4.5, another stable unfolding intermediate of L68Q cystatin C was identified. This molecular form exists in a monomeric state, is characterized by changes in secondary structure according to far UV CD spectroscopy, and shows an altered ANS binding resembling that of a molten globule state. The acidic pH also caused an almost complete monomerization of preformed dimers. The state of denaturation of L68Q cystatin C in vivo is thus a critical factor for the concentration of active cysteine proteinase inhibitor in cerebrospinal fluid and likely also for the development of amyloidosis, in HCCAA patients.
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PMID:Two stable unfolding intermediates of the disease-causing L68Q variant of human cystatin C. 986 Aug 45

Morphometry of the cerebellum of 11 subjects who died in the severe, final stage of Alzheimer's disease (AD) and of five age-matched subjects without dementia revealed significant atrophy in the AD group, with a decrease in the volume of the molecular layer by 24% and of the granular layer by 22% in comparison with controls. The 32% decrease in the total number of Purkinje cells that was observed correlates with the atrophy of the molecular layer, whereas the 30% reduction in the total number of granule cells correlates with the atrophy of the molecular and granular layers. A unique pattern of Alzheimer-type pathology was observed in the cerebellum: (1) there were no neurofibrillary changes in the cerebellum of either the control or the AD subjects, (2) there was almost the same extent of leptomeningeal and cortical amyloid angiopathy in the normal aged subjects and in the AD patients, and (3) the presence of plaques was noted in the AD group, but not in the control group. This pattern of pathology suggests that two factors might be considered in the etiopathogenesis of cerebellar atrophy: (1) transneuronal degeneration and neuronal loss resulting from primary pathologic changes in cerebral structures and (2) parenchymal cerebellar ss-amyloidosis. The correlation between the temporal duration of AD and both the decrease of the total number of granule cells (r=0.86, p<0.01) and the volumetric loss of the molecular (r=0.73, p<0.05) and granular (r=0.93, p<0.001) layers of the cerebellar cortex indicates that these cerebellar atrophic changes are likely to be related to the basic pathologic process of AD. Similarly, the correlation between the most complex parameter the atrophy of the cerebellar cortex and the Functional Assessment Staging (FAST) measure of the clinical severity of AD at the time of demise (r=0.63, p<0.05) as well as with the duration of AD (r=0.78, p<0.01) indicates that cerebellar pathology, when viewed holistically, evolves continuously in association with clinical changes throughout the clinically manifest course of AD.
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PMID:Cerebellar atrophy in Alzheimer's disease-clinicopathological correlations. 991 36


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