58 research outputs found

    Antioxidant airway responses following experimental exposure to wood smoke in man

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    Background: Biomass combustion contributes to the production of ambient particulate matter (PM) in rural environments as well as urban settings, but relatively little is known about the health effects of these emissions. The aim of this study was therefore to characterize airway responses in humans exposed to wood smoke PM under controlled conditions. Nineteen healthy volunteers were exposed to both wood smoke, at a particulate matter (PM2.5) concentration of 224 +/- 22 mu g/m(3), and filtered air for three hours with intermittent exercise. The wood smoke was generated employing an experimental set-up with an adjustable wood pellet boiler system under incomplete combustion. Symptoms, lung function, and exhaled NO were measured over exposures, with bronchoscopy performed 24 h post-exposure for characterisation of airway inflammatory and antioxidant responses in airway lavages. Results: Glutathione (GSH) concentrations were enhanced in bronchoalveolar lavage (BAL) after wood smoke exposure vs. air (p = 0.025), together with an increase in upper airway symptoms. Neither lung function, exhaled NO nor systemic nor airway inflammatory parameters in BAL and bronchial mucosal biopsies were significantly affected. Conclusions: Exposure of healthy subjects to wood smoke, derived from an experimental wood pellet boiler operating under incomplete combustion conditions with PM emissions dominated by organic matter, caused an increase in mucosal symptoms and GSH in the alveolar respiratory tract lining fluids but no acute airway inflammatory responses. We contend that this response reflects a mobilisation of GSH to the air-lung interface, consistent with a protective adaptation to the investigated wood smoke exposure

    Sinteza, in vitro antitumorsko ispitivanje i radiosenzitirajuće vrednovanje novih derivata 4-[3-(supstituiranih)tioureido]-N-(kinoksalin-2-il)benzensulfonamida

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    Sulfonamides and quinoxaline derivatives possess many types of biological activities and have been recently reported to show substantial antitumor activity. This paper reports the synthesis of novel thioureidosulfaquinoxaline derivatives. All the newly synthesized compounds were evaluated for their in vitro anticancer activity against a human liver cell line (HEPG2) and showed higher activity than the reference drug doxorubicin. 4-(3-(4-Ethylbenzoate)thioureido)-N-(quinoxalin-2-yl)benzenesulfonamide (9) (IC50 = 15.6 µmol L1), N-(pyridin-2-yl)-4-(3-(4-(N-quinoxalin-2-yl-sulfamoyl)phenyl)thioureido)benzene-sulfonamide (10) (IC50 = 26.8 µmol L1) and N-(quinoxalin-2-yl)-4-(3-(4-(N-thiazol-2-ylsulfamoyl)phenyl)thioureido)benzenesulfonamide (11) (IC50 = 24.4 µmol L1) were the most potent compared to doxorubicin (IC50 = 71.8 µmol L1). The most potent compounds 9, 10 and 11 were evaluated as radiosensitizing agents by subjecting the compounds to γ-irradiation (8 kGy).Derivati sulfonamida i kinoksalina imaju raznoliko biološko djelovanje, između ostalog i antitumorsko djelovanje. U radu je opisana sinteza novih derivata tioureido sulfakinoksalina. Svim novim spojevima ispitano je antitumorsko djelovanje in vitro na humanoj staničnoj liniji jetre (HEPG 2). Svi ispitani spojevi pokazuju jači učinak nego referentni lijek doksorubicin. Najjači učinak imali su 4-(3-(4-etilbenzoat)tioureido)-N-(kinoksalin-2-il)benzen-sulfonamid (9) (IC50 = 15,6 µmol L1), N-(piridin-2-il)-4-(3-(4-(N-kinoksalin-2-il-sulfamoil)fenil)tioureido)-benzen-sulfonamid (10) (IC50 = 26,8 µmol L1) i N-(kinoksalin-2-il)-4-(3-(4-(N-tiazol-2-ilsulfamoil)fenil)tioureido)benzen-sulfonamid (11) (IC50 = 24,4 µmol L1), dok je IC50 vrijednost bila 71,8 µmol L1. Najaktivniji spojevi 9, 10 i 11 evaluirani su kao radziosenzitirajuća sredstva nakon izlaganja spojeva γ-zračenju (8 kGy)

    Nav1.7 is required for normal C-low threshold mechanoreceptor function in humans and mice

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    Patients with bi-allelic loss of function mutations in the voltage-gated sodium channel Nav1.7 present with congenital insensitivity to pain (CIP), whilst low threshold mechanosensation is reportedly normal. Using psychophysics (n = 6 CIP participants and n = 86 healthy controls) and facial EMG (n = 3 CIP participants and n = 8 healthy controls) we have found that these patients also have abnormalities in the encoding of affective touch which is mediated by the specialised afferents; C-low threshold mechanoreceptors (C-LTMRs). In the mouse we found that C-LTMRs express high levels of Nav1.7. Genetic loss or selective pharmacological inhibition of Nav1.7 in C-LTMRs resulted in a significant reduction in the total sodium current density, an increased mechanical threshold and reduced sensitivity to non-noxious cooling. The behavioural consequence of loss of Nav1.7 in C-LTMRs in mice was an elevation in the von Frey mechanical threshold and less sensitivity to cooling on a thermal gradient. Nav1.7 is therefore not only essential for normal pain perception but also for normal C-LTMR function, cool sensitivity and affective touch

    Photocatalytic Decomposition of Formic Acid on Mo2C-Containing Catalyst

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    Soluble components in the peripheral blood from experimental exposure of 14 healthy subjects to filtered air and wood smoke. Samples were collected before (pre), at 24 h and 44 h after exposure, to air and wood smoke. Data are given as medians with interquartile range. (DOCX 62 kb

    DNA structural features responsible for sequence-dependent binding geometries of Hoechst 33258

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    The complexes of Hoechst 33258 with poly[d(A-T)(2)], poly[d(I-C)(2)], poly[d(G-C)(2)], and poly[d(G-m(5)C)(2)] were studied using linear dichroism, CD, and fluorescence spectroscopies. The Hoechst-poly[d(I-C)(2)] complex, in which there is no quanine amino group protruding in the minor groove, exhibit spectroscopic properties that are very similar to those of the Hoechst-poly[d(A-T)(2)] complex. When bound to both of these polynucleotides, Hoechst exhibits an average orientation angle of near 45 degrees relative to the DNA helix axis for the long-axis polarized low-energy transition, a relatively strong positive induced CD, and a strong increase in fluorescence intensity-leading us to conclude that this molecule also binds in the minor groove of poly[d(I-C)(2)]. By contrast, when bound to poly[d(G-C)(2)], Hoechst shows a distinctively different behavior. The strongly negative reduced linear dichroism in the ligand absorption region is consistent with a model in which part of the Hoechst chromophore is intercalculated between DNA bases. From the low drug:base ratio onset of excitonic effects in the CD and fluorescence emission spectra, it is inferred that another part of the Hoechst molecule may sit in the major groove of poly[d(G-C)(2)] and poly[d(G-m(5)C)(2)] and preferentially stacks into dimers, though this tendency is strongly reduced for the latter polynucleotide. Based on these results, the importance of the interactions of Hoechst with the exocyclic amino group of guanine and the methyl group of cytosine in determining the binding modes are discussed
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