In this paper, we show that human neuroectodermal cells exposed to 1–5 mM hydrogen peroxide or 10 nM-1 mM ascorbate die by programmed cell death induced by oxidative stress. The cell death by ...peroxide occurs within 4 h and involves approximately 80% of B-mel melanoma cells, while ascorbate causes cell death of approximately 86% of B-mel cells within 24 h. SK-N-BE(2) neuroblastoma cells are more resistant, 32% and 43% cell death for peroxide and ascorbate, respectively. In all cases, cell death causes hypodiploic DNA staining, evaluated by flow cytometry. Both cell lines can efficiently metabolise ascorbate due to significant levels of NADH-dependent semidehydroascorbate reductase and glutathione-dependent dehydroascorbate reductase. The cell death observed suggests a pro-oxidant, rather than anti-oxidant, role for ascorbic acid at physiological concentrations under these experimental conditions.
Ice crystal clouds in the upper troposphere can generate polarization signals at the μK level. This signal can seriously affect very sensitive ground-based searches for E and B modes of cosmic ...microwave background polarization. In this paper, we estimate this effect within the CℓOVER experiment observing bands (97, 150 and 220 GHz) for the selected observing site (Llano de Chajnantor, Atacama desert, Chile). The results show that the polarization signal from the clouds can be of the order of or even bigger than the cosmic microwave background expected polarization. Climatological data suggest that this signal is fairly constant over the whole year in Antarctica. On the other hand, the stronger seasonal variability in Atacama allows for a 50 per cent of clean observations during the dry season.
A pi-conjugated polymer, polyphenylacetylene or PPA, has been tested for its possible applications as biosensor or biomaterial. Protein adsorption was investigated by incubating PPA films in ...solutions of bovine serum albumin (BSA) dissolved in phosphate buffer (PBS) having increasing protein concentration. Investigations on the PPA films were carried out by means of two surface analysis techniques, X-ray photoelectron spectroscopy (XPS) and reflection-absorption infrared spectroscopy (RAIRS). Desorption of BSA from the PPA surface was also investigated. Finally, the cytototoxicity of the PPA surface was checked by measuring viability and proliferation of lymphoma macrophages and SAOS osteoblasts grown in the presence of the polymer.
Based upon synthetic and biochemical results, a novel and potent tacrine analogue and heterobivalent analogues of tacrine, were designed. The role played by the amino groups of homo- and ...heterobivalent ligands in the interaction with the peripheral and catalytic sites of AChE and BuChE were investigated. The syntheses of these materials together with the results of AChE/BuChE inhibition assays are detailed.
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The glycoprotein CD30 is expressed and released by T lymphocytes that secrete type 2 helper cytokines of (T(H)2). These molecules play a role in the pathogenesis of allergic diseases. Venom ...immunotherapy has proven to be very effective in hymenoptera venom allergy through a shift in cytokine production from T(H)2-type cytokines to T(H)1-type cytokines.
To evaluate the relationship between the soluble form of CD30 (sCD30) and venom immunotherapy in patients with hymenoptera venom allergy.
sCD30 levels were assayed by enzyme-linked immunosorbent assay in the sera of 61 healthy controls and 14 patients with hymenoptera venom allergy who had undergone immunotherapy before treatment and 1,3, and 12 months after treatment started. Nine patients were allergic to Apis venom, 4 to Vespula venom, and 1 to Polistes venom.
CD30 serum levels (median, interquartile range) were significantly higher in venom-allergic patients before treatment (33.6 U/mL; 14.8-61.6) than in controls (9.7 U/mL, 1.9-21.3) (P < .000). These levels decreased progressively during treatment in all patients except 2 (P < .000). At the third month of therapy, the levels reached statistical significance in comparison with baseline.
This study shows that sCD30 levels are significantly higher in patients with hymenoptera venom allergy and indirectly confirms a preferential T(H)2-type cytokine production in these patients. sCD30 expression decreases during immunotherapy, thus confirming the immunomodulatory role of this treatment in promoting a shift to T(H)1-type cytokines.
Invasive aspergillosis (IA) is the leading direct or contributory cause of death in patients with haematological malignancies. Early diagnosis remains difficult and often elusive due the ...heterogeneity of clinical presentations and the low sensitivity of both histological examination and cultures of specimens obtained from patients at risk. We report two cases of IA, both of which lacked both histological and cultural evidence of IA from pulmonary specimens. In both patients, detection of galactomannan (GM) by enzyme immunoassay (EIA) on pulmonary tissue homogenates led to the diagnosis of IA, which was confirmed by
Aspergillus
DNA (real time PCR). In conclusion, we provide preliminary evidence that lung homogenates may be prepared for GM EIA assays, which may contribute to quick diagnosis of IA on otherwise negative samples. We feel that our results open up the opportunity of a prospective and comparative evaluation of this diagnostic technique.
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