28 research outputs found
Antioxidative potential of a combined therapy of anti TNFα and Zn acetate in experimental colitis.
AIM: To evaluate whether combination therapy with anti-tumour necrosis factor α
(TNFα) antibody and Zn acetate is beneficial in dextran sodium sulphate (DSS)
colitis.
METHODS: Colitis was induced in CD1-Swiss mice with 5% DSS for 7 d. The
experimental mice were then randomised into the following subgroups: standard
diet + DSS treated (induced colitis group); standard diet + DSS + subcutaneous 25
μg anti-TNFα treated group; Zn acetate treated group + DSS + subcutaneous 25 μg
anti-TNFα; standard diet + DSS + subcutaneous 6.25 μg anti-TNFα treated group and
Zn acetate treated group + DSS + subcutaneous 6.25 μg anti-TNFα. Each group of
mice was matched with a similar group of sham control animals. Macroscopic and
histological features were scored blindly. Homogenates of the colonic mucosa were
assessed for myeloperoxidase activity as a biochemical marker of inflammation and
DNA adducts (8OH-dG) as a measure of oxidative damage.
RESULTS: DSS produced submucosal erosions, ulcers, inflammatory cell infiltration
and cryptic abscesses which were reduced in both groups of mice receiving either
anti-TNFα alone or combined with zinc. The effect was more pronounced in the
latter group (vs Zn diet, P < 0.02). Myeloperoxidase activity (vs controls, P <
0.02) and DNA adducts, greatly elevated in the DSS fed colitis group (vs
controls, P < 0.05), were significantly reduced in the treated groups, with a
more remarkable effect in the group receiving combined therapy (vs standard diet,
P < 0.04).
CONCLUSION: DSS induces colonic inflammation which is modulated by the
administration of anti-TNFα. Combining anti-TNFα with Zn acetate offers marginal
benefit in colitis severity
Expression and function of human hemokinin-1 in human and guinea pig airways
<p>Abstract</p> <p>Background</p> <p>Human hemokinin-1 (hHK-1) and endokinins are peptides of the tachykinin family encoded by the <it>TAC4 </it>gene. <it>TAC4 </it>and hHK-1 expression as well as effects of hHK-1 in the lung and airways remain however unknown and were explored in this study.</p> <p>Methods</p> <p>RT-PCR analysis was performed on human bronchi to assess expression of tachykinin and tachykinin receptors genes. Enzyme immunoassay was used to quantify hHK-1, and effects of hHK-1 and endokinins on contraction of human and guinea pig airways were then evaluated, as well as the role of hHK-1 on cytokines production by human lung parenchyma or bronchi explants and by lung macrophages.</p> <p>Results</p> <p>In human bronchi, expression of the genes that encode for hHK-1, tachykinin NK<sub>1</sub>-and NK<sub>2</sub>-receptors was demonstrated. hHK-1 protein was found in supernatants from explants of human bronchi, lung parenchyma and lung macrophages. Exogenous hHK-1 caused a contractile response in human bronchi mainly through the activation of NK<sub>2</sub>-receptors, which blockade unmasked a NK<sub>1</sub>-receptor involvement, subject to a rapid desensitization. In the guinea pig trachea, hHK-1 caused a concentration-dependant contraction mainly mediated through the activation of NK<sub>1</sub>-receptors. Endokinin A/B exerted similar effects to hHK-1 on both human bronchi and guinea pig trachea, whereas endokinins C and D were inactive. hHK-1 had no impact on the production of cytokines by explants of human bronchi or lung parenchyma, or by human lung macrophages.</p> <p>Conclusions</p> <p>We demonstrate endogenous expression of <it>TAC4 </it>in human bronchi, the encoded peptide hHK-1 being expressed and involved in contraction of human and guinea pig airways.</p
Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites
The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe