51 research outputs found
Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression
Abstract Background Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent. We hypothesized that quercetin reduces lung inflammation and improves lung function in elastase/lipopolysaccharide (LPS)-exposed mice which show typical features of COPD, including airways inflammation, goblet cell metaplasia, and emphysema. Methods Mice treated with elastase and LPS once a week for 4 weeks were subsequently administered 0.5 mg of quercetin dihydrate or 50% propylene glycol (vehicle) by gavage for 10 days. Lungs were examined for elastance, oxidative stress, inflammation, and matrix metalloproteinase (MMP) activity. Effects of quercetin on MMP transcription and activity were examined in LPS-exposed murine macrophages. Results Quercetin-treated, elastase/LPS-exposed mice showed improved elastic recoil and decreased alveolar chord length compared to vehicle-treated controls. Quercetin-treated mice showed decreased levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation caused by oxidative stress. Quercetin also reduced lung inflammation, goblet cell metaplasia, and mRNA expression of pro-inflammatory cytokines and muc5AC. Quercetin treatment decreased the expression and activity of MMP9 and MMP12 in vivo and in vitro, while increasing expression of the histone deacetylase Sirt-1 and suppressing MMP promoter H4 acetylation. Finally, co-treatment with the Sirt-1 inhibitor sirtinol blocked the effects of quercetin on the lung phenotype. Conclusions Quercetin prevents progression of emphysema in elastase/LPS-treated mice by reducing oxidative stress, lung inflammation and expression of MMP9 and MMP12.http://deepblue.lib.umich.edu/bitstream/2027.42/78260/1/1465-9921-11-131.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78260/2/1465-9921-11-131.pdfPeer Reviewe
The holographic principle
There is strong evidence that the area of any surface limits the information
content of adjacent spacetime regions, at 10^(69) bits per square meter. We
review the developments that have led to the recognition of this entropy bound,
placing special emphasis on the quantum properties of black holes. The
construction of light-sheets, which associate relevant spacetime regions to any
given surface, is discussed in detail. We explain how the bound is tested and
demonstrate its validity in a wide range of examples.
A universal relation between geometry and information is thus uncovered. It
has yet to be explained. The holographic principle asserts that its origin must
lie in the number of fundamental degrees of freedom involved in a unified
description of spacetime and matter. It must be manifest in an underlying
quantum theory of gravity. We survey some successes and challenges in
implementing the holographic principle.Comment: 52 pages, 10 figures, invited review for Rev. Mod. Phys; v2:
reference adde
Modeling and development of a decision support system for supplier selection in the process industry
Towards a Holographic Model of Color-Flavor Locking Phase
We demonstrate a holographic realization of color-flavor locking phase, using
N=4 SU(Nc) SYM coupled to N=2 Nf fundamental hypermultiplets as an example. The
gravity dual consists of Nc D3-branes and Nf D7-branes with world volume gauge
field representing the baryon density. Treating a small number \tilde{N}c << Nc
of D3-branes as Yang-Mills instantons on the D7-branes, we consider possible
potential(s) on their moduli space or equivalently the Higgs branch. We show
that a non-trivial potential can be generated by including the backreaction of
the baryonic density on the D7-branes, this dynamically drives the instantons
(= D3-branes) into dissolution. We interpret this as a color-flavor locking
since the size of the instanton is the squark vev, and study the symmetry
breaking patterns. Extending to finite temperature setup, we demonstrate that
color-flavor locking persists, and the thermal effect provides additional
structures in the phase diagram.Comment: 1+38 pages, 6 eps figures; typos corrected, acknowledgment and
references added, discussions in sections 3.1 and 4.3 improve
Evaluation of a wetland classification system devised for management in a region with a high cover of peatlands: an example from the Cook Inlet Basin, Alaska
Influence of particle size on the heat release rate and smoke opacity during the burning of dead Cistus leaves and twigs
Glossopharyngeal Neuralgia, An Usually Overlooked Diagnosis: A Prospective Single Center Observation Study
Perceptions of crop raiding: effects of land tenure and agro-industry on human-wildlife conflict
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