29 research outputs found
Amyloid-\u3b225-35, an Amyloid-\u3b21-42 Surrogate, and Proinflammatory Cytokines Stimulate VEGF-A Secretion by Cultured, Early Passage, Normoxic Adult Human Cerebral Astrocytes
Cerebrovascular angiopathy affects late-onset Alzheimer's disease (LOAD) brains by possibly increasing vascular endothelial growth factor (VEGF). A expression, thereby stimulating endothelial cell proliferation and migration. Indeed, VEGF-A gene upregulation, with increased VEGF-A protein content of reactive astrocytes and microglia, occurs in LOAD brains, and neovascularization was observed one week after injecting amyloid-\u3b2 (A\u3b2)1-42 into rat hippocampus. We have now found, with cultured 'normoxic' normal adult human astrocytes (NAHAs), that fibrillar A\u3b225-35 (an active A\u3b21-42 fragment) or a cytokine mixture (the (CM)-trio (interleukin [IL]-1\u3b2+interferon [IFN]-\u3b3+tumor necrosis factor [TNF]-\u3b1), or pair (IFN-\u3b3+TNF-\u3b1) like those produced in LOAD brains) stimulates the nuclear translocation of stabilized hypoxia-inducible factor (HIF)-1\u3b1 protein and its binding to VEGF-A hypoxia-response elements; the mRNA synthesis for three VEGF-A splice variants (121, 165, 189); and the secretion of VEGF-A165. The CM-trio was the most powerful stimulus, IFN-\u3b3+TNF-\u3b1 was less potent, and other cytokine pairs or single cytokines or A\u3b235-25 were ineffective. While A\u3b225-35 did not change HIF-1\u3b2 protein levels, the CM-trio increased both HIF-1\u3b1 and HIF-1\u3b2 protein levels, thereby giving an earlier and stronger stimulus to VEGF-A secretion by NAHAs. Thus, increased VEGF-A secretion from astrocytes stimulated by A\u3b21-42 and by microglia-released cytokines might restore angiogenesis and A\u3b21-42 vascular clearance
Provenancing Archaeological Wool Textiles from Medieval Northern Europe by Light Stable Isotope Analysis (δ13C, δ15N, δ2H)
We investigate the origin of archaeological wool textiles preserved by anoxic waterlogging from seven medieval archaeological deposits in north-western Europe (c. 700-1600 AD), using geospatial patterning in carbon (δ13C), nitrogen (δ15N) and non-exchangeable hydrogen (δ2H) composition of modern and ancient sheep proteins. δ13C, δ15N and δ2H values from archaeological wool keratin (n = 83) and bone collagen (n = 59) from four sites were interpreted with reference to the composition of modern sheep wool from the same regions. The isotopic composition of wool and bone collagen samples clustered strongly by settlement; inter-regional relationships were largely parallel in modern and ancient samples, though landscape change was also significant. Degradation in archaeological wool samples, examined by elemental and amino acid composition, was greater in samples from Iceland (Reykholt) than in samples from north-east England (York, Newcastle) or northern Germany (Hessens). A nominal assignment approach was used to classify textiles into local/non-local at each site, based on maximal estimates of isotopic variability in modern sheep wool. Light element stable isotope analysis provided new insights into the origins of wool textiles, and demonstrates that isotopic provenancing of keratin preserved in anoxic waterlogged contexts is feasible. We also demonstrate the utility of δ2H analysis to understand the location of origin of archaeological protein samples
Amyloid-beta peptide induces HIF transcription factor and VEGF expression in cultured normal adult human astrocytes.
Amyloid-beta peptide induces HIF transcription factor and VEGF expression in cultured normal adult human astrocytes
Comparison of diagnostic accuracy of five serodiagnostic tests for strongyloidiasis
This abstract describes a diagnostic studies on five different serologic tests for S. stercoralis
Study of the gas optical sensing properties of Au-polyimide nanocomposite films prepared by ion implantation
Study of the gas optical sensing properties of Au-polyimide nanocomposite films prepared by ion implantation
Au-polyimide nanocomposites have been synthesized by implanting Au+ ions in pyromellitic dianhydride-4,4' oxydianiline polyimide films prepared by glow discharge vapor deposition polymerisation (GDVDP). A structural and optical characterization shows that Au clusters grow only implanting 5Ă—10exp16 Au+/cm2. This sample class shows interesting dynamic optical absorption sensing responses towards methanol and ethanol vapors in the spectral range corresponding to the surface plasmon resonance (SPR) peak of the gold nanoparticles. Traditional surface plasmon resonance measurements performed onto virgin polyimide thin films in controlled atmosphere show a sensing activity due to a variation of the film thickness and of the real part of refractive index. The comparison of the results obtained onto virgin films and implanted ones suggests that the sensing mechanisms can be attributed both to the modification of polymer optical properties and to the chemical activity of gold nanoparticles