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Immunochemical Methods (immunochemical + methods)
Selected AbstractsClassical sheep transmissible spongiform encephalopathies: pathogenesis, pathological phenotypes and clinical diseaseNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 4 2007M. Jeffrey Scrapie is a prion disease or transmissible spongiform encephalopathy (TSE) of sheep, goats and moufflon. As with its human counterparts, pathology consists of vacuolation, gliosis and accumulations of abnormal forms of a host prion protein (PrPd) in the brain of affected individuals. Immunohistochemical methods can be used to identify both the intracellular truncation sites of PrPd in different cell types (PrPd epitope mapping) and the different morphological patterns of accumulation (PrPd profiling). Differences in the inferred truncation sites of PrPd are found for different strains of sheep TSEs and for different infected cell types within individual strains. Immunochemical methods of characterizing strains broadly correspond to PrPd mapping discriminatory results, but distinct PrPd profiles, which provide strain- and source-specific information on both the cell types which sustain infection (cellular tropisms) and the cellular processing of PrPd, have no immunoblotting counterparts. The cause of neurological dysfunction in human is commonly considered to be neuronal loss secondary to a direct or indirect effect of the accumulation of PrPd. However, in sheep scrapie there is no significant neuronal loss, and relationships between different magnitudes, topographical and cytological forms of PrPd accumulation and clinical signs are not evident. PrPd accumulation also occurs in lymphoid tissues, for which there is indirect evidence of a pathological effect, in the peripheral nervous system and in other tissues. It is generally assumed that neuroinvasion results from infection of the enteric nervous system neurones subsequent to amplification of infectivity in lymphoid tissues and later spread via sympathetic and parasympathetic pathways. The evidence for this is, however, circumstantial. Accumulation of PrPd and presence of infectivity in tissues other than the nervous and lymphoreticular systems gives insights on the ways of transmission of infection and on food safety. [source] Synapse loss in dementiasJOURNAL OF NEUROSCIENCE RESEARCH, Issue 10 2010Ryan Clare Abstract Synaptic transmission is essential for nervous system function, and its dysfunction is a known major contributing factor to Alzheimer's-type dementia. Antigen-specific immunochemical methods are able to characterize synapse loss in dementia through the quantification of various synaptic proteins involved in the synaptic cycle. These immunochemical methods applied to the study of Alzheimer's disease (AD) brain specimens have correlated synaptic loss with particularly toxic forms of amyloid-, protein and have also established synapse loss as the best correlate of dementia severity. A significant but comparatively circumscribed amount of literature describes synaptic decline in other forms of dementia. Ischemic vascular dementia (IVD) is quite heterogeneous, and synapse loss in IVD seems to be variable among IVD subtypes, probably reflecting its variable neuropathologic correlates. Loss of synaptic protein has been identified in vascular dementia of the Binswanger type and Spatz-Lindenberg's disease. Here we demonstrate a significant loss of synaptophysin density within the temporal lobe of frontotemporal dementia (FTD) patients. © 2010 Wiley-Liss, Inc. [source] A convenient and sensitive allergy test: IgE crosslinking-induced luciferase expression in cultured mast cellsALLERGY, Issue 10 2010R. Nakamura To cite this article: Nakamura R, Uchida Y, Higuchi M, Nakamura R, Tsuge I, Urisu A, Teshima R. A convenient and sensitive allergy test: IgE crosslinking,induced luciferase expression in cultured mast cells. Allergy 2010; 65: 1266,1273. Abstract Background:, For the detection of allergen-specific IgE in sera, solid-phase IgE-binding assays like the CAP test are commonly used. Although such immunochemical methods are very sensitive, they frequently produce false positives. Degranulation of the human IgE receptor (Fc,RI)-transfected rat mast cell (RBL) lines seems to be a possible indicator for human IgE, but spontaneous mediator release from these cells in the presence of human sera is not negligible. Methods:, The nuclear factor of activated T-cells (NFAT)-responsive luciferase reporter gene was stably transfected into human Fc,RI-expressing RBL-SX38 cells. One established clone (RS-ATL8) was sensitized with 1 : 100 dilution of sera from patients with egg white allergy and then stimulated with purified or a crude extract of egg white allergen. Results:, Sensitization with 15 pg/ml IgE was sufficient to detect IgE crosslinking,induced luciferase expression (EXiLE) by anti-IgE stimulation. Allergen-specific EXiLE was elicited by as little as 1 fg/ml of egg white protein without cytotoxicity. There was a good correlation between results with EXiLE and oral food challenge tests on patients with egg allergy (P = 0.001687, Fisher's exact test). The measured values of EXiLE and the CAP test also correlated well (R = 0.9127, Spearman's test). Conclusion:, The EXiLE test using RS-ATL8 cells is a promising in vitro IgE test to evaluate the biological activity of the binding between IgE and allergens. [source] Quantification of Alzheimer pathology in ageing and dementia: age-related accumulation of amyloid-,(42) peptide in vascular dementiaNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 2 2006H. Lewis Clinicopathological observations suggest there is considerable overlap between vascular dementia (VaD) and Alzheimer's disease (AD). We used immunochemical methods to compare quantities of amyloid-, (A,) peptides in post mortem brain samples from VaD, AD subjects and nondemented ageing controls. Total A, peptides extracted from temporal and frontal cortices were quantified using a previously characterized sensitive homogenous time-resolved fluorescence (HTRF) assay. The HTRF assays and immunocapture mass spectrometric analyses revealed that the A,(42) species were by far the predominant form of extractable peptide compared with A,(40) peptide in VaD brains. The strong signal intensity for the peak representing A,(4,42) peptide confirmed that these N-terminally truncated species are relatively abundant. Absolute quantification by HTRF assay showed that the mean amount of total A,(42) recovered from VaD samples was approximately 50% of that in AD, and twice that in the age-matched controls. Linear correlation analysis further revealed an increased accumulation with age of both A, peptides in brains of VaD subjects and controls. Interestingly, VaD patients surviving beyond 80 years of age exhibited comparable A,(42) concentrations with those in AD in the temporal cortex. Our findings suggest that brain A, accumulates increasingly with age in VaD subjects more so than in elderly without cerebrovascular disease and support the notion that they acquire Alzheimer-like pathology in older age. [source] | ||||||||||