1,193 research outputs found

    Preliminary observations on the utilisation of pig-dung effluent for fish production

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    In developing Singapore where agricultural land is making way for urbanisation and industrialisation, carp culture is being looked upon from a new perspective. It is obvious that the wanton discharge of animal waste will eventually result in polluted streams, reservoirs and coastal waters. In view of the above, preliminary investigations were carried out to evaluate the use of cess-pit effluent of pig dung for carp production. Initial results indicate that the carp pond can serve as a buffer zone where organic wastes can be cheaply and profitably removed, thereby minimising the subsequent pollution of our inland and coastal waters. However, further investigations are necessary to substantiate the use of carp ponds not only for fish production but also to serve as a reservoir for the biological reduction of organic pollutants

    Glutathione Peroxidase-1 Primes Pro-Inflammatory Cytokine Production after LPS Challenge In Vivo

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    Reactive oxygen species produced during the innate immune response to LPS are important agents of anti-pathogen defence but may also cause oxidative lung damage. Glutathione peroxidase-1 (gpx-1) is an anti-oxidant enzyme that may protect lungs from such damage. We assessed the in vivo importance of gpx-1 in LPS-induced lung inflammation. Male wild-type (WT) or gpx-1 deficient (gpx-1−/−) mice were treated intranasally with PBS or 10 µg LPS and killed 3 and 24 h post LPS. Lungs were lavaged with PBS and then harvested for inflammatory marker expression. LPS caused an intense neutrophilia in WT BALF evident 3 and 24 h post challenge that was reduced in gpx-1−/− mice. In addition, LPS-treated gpx-1−/− mice had significantly fewer macrophages than LPS-treated WT mice. To understand the basis for this paradoxical reduction we assessed inflammatory cytokines and proteases at protein and transcript levels. MMP-9 expression and net gelatinase activity in BALF of gpx-1−/− mice treated with LPS for 3 and 24 h was no different to that found in LPS-treated WT mice. BALF from LPS-treated gpx-1−/− mice (3 h) had less TNF-α, MIP-2 and GM-CSF protein than LPS-treated WT mice. In contrast, LPS-induced increases in TNF-α, MIP-2 and GM-CSF mRNA expression in WT mice were similar to those observed in gpx-1−/− mice. These attenuated protein levels were unexpectedly not mirrored by reduced mRNA transcripts but were associated with increased 20S proteasome expression. Thus, these data suggest that gpx-1 primes pro-inflammatory cytokine production after LPS challenge in vivo

    Apocynin and ebselen reduce influenza A virus-induced lung inflammation in cigarette smoke-exposed mice

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    Influenza A virus (IAV) infections are a common cause of acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Oxidative stress is increased in COPD, IAV-induced lung inflammation and AECOPD. Therefore, we investigated whether targeting oxidative stress with the Nox2 oxidase inhibitors and ROS scavengers, apocynin and ebselen could ameliorate lung inflammation in a mouse model of AECOPD. Male BALB/c mice were exposed to cigarette smoke (CS) generated from 9 cigarettes per day for 4 days. On day 5, mice were infected with 1 × 104.5 PFUs of the IAV Mem71 (H3N1). BALF inflammation, viral titers, superoxide production and whole lung cytokine, chemokine and protease mRNA expression were assessed 3 and 7 days post infection. IAV infection resulted in a greater increase in BALF inflammation in mice that had been exposed to CS compared to non-smoking mice. This increase in BALF inflammation in CS-exposed mice caused by IAV infection was associated with elevated gene expression of pro-inflammatory cytokines, chemokines and proteases, compared to CS alone mice. Apocynin and ebselen significantly reduced the exacerbated BALF inflammation and pro-inflammatory cytokine, chemokine and protease expression caused by IAV infection in CS mice. Targeting oxidative stress using apocynin and ebselen reduces IAV-induced lung inflammation in CS-exposed mice and may be therapeutically exploited to alleviate AECOPD

    Inhibitory effects of bisbenzylisoquinolines on synthesis of the inflammatory cytokines interleukin-1 and tumour necrosis factor-alpha

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    Synthesis of IL-1β and TNFα by human monocytesmacrophages was significantly inhibited by eleven bisbenzylisoquinolines and one half-molecule (benzylisoquinoline), with IC50 values in the μM range. The results indicate that these compounds may have value in the therapy of human diseases where these inflammatory cytokines have a central role in pathogenesis

    Longitudinal Current Dissipation in Bose-glass Superconductors

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    A scaling theory of vortex motion in Bose glass superconductors with currents parallel to the common direction of the magnetic field and columnar defects is presented. Above the Bose-glass transition the longitudinal DC resistivity ρ(T)(TTBG)νz\rho_{||}(T)\sim (T-T_{BG})^{\nu' z'} vanishes much faster than the corresponding transverse resistivity ρ(T)(TTBG)ν(z2)\rho_{\perp}(T)\sim (T-T_{BG})^{\nu' (z'-2)}, thus {\it reversing} the usual anisotropy of electrical transport in the normal state of layered superconductors. In the presence of a current J\bf J at an angle θJ\theta_J with the common field and columnar defect axis, the electric field angle θE\theta_E approaches π/2\pi/2 as TTBG+T\rightarrow T_{BG}^+. Scaling also predicts the behavior of penetration depths for the AC currents as TTBGT\rightarrow T_{BG}^-, and implies a {\it jump discontinuity} at TBGT_{BG} in the superfluid density describing transport parallel to the columns.Comment: 5 pages, revte
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