1,117 research outputs found
Efficacy of topical cobalt chelate CTC-96 against adenovirus in a cell culture model and against adenovirus keratoconjunctivitis in a rabbit model
BACKGROUND: Adenovirus (Ad), associated with significant morbidity, has no topical treatment. A leading CTC compound (CTC-96), a Co(III )chelate, was found to have potent in vitro and in vivo antiviral efficacy against herpes viruses. In this study CTC-96 is being tested for possible anti-Adenovirus activity. METHODS: The biological anti-adenovirus activity of CTC-96 in concentrations from 5 to 250 ug/ml, was evaluated initially by viral inactivation (viral exposure to CTC-96 followed by dilution and inoculation of cells), virucidal (viral exposure to CTC-96 and inoculation of cells without dilution) and antiviral (effect of CTC-96 on previously adsorbed virus) plaque assays on HeLa (human cervical carcinoma), A549 (human lung carcinoma) and SIRC (rabbit corneal) cells. After verifying the antiviral activity, New Zealand White rabbits were infected with Ad-5 into: 1) the anterior cul-de-sac scarifying the conjunctiva (Group "C+"); 2) the anterior cul-de-sac scarifying the conjunctiva and cornea (Group "CC+"); 3) the stroma (Group "CI+"). Controls were sham-infected ("C-", "CC-", "CI-"). Other rabbits, after "CC", were treated for 21 days with: 1) placebo, 9x/day ("-"); 2) CTC-96, 50 ug/ml, 9x/day ("50/9"); CTC-96, 50 ug/ml, 6x/day ("50/6"); CTC-96, 25 ug/ml, 6x/day ("25/6"). All animals were monitored via examination and plaque assays. RESULTS: In vitro viral inactivation, virucidal and antiviral assays all demonstrated CTC-96 to be effective against Adenvirus type 5 (ad-5). The in vivo model of Ad keratoconjunctivitis most similar to human disease and producing highest viral yield was "CC". All eyes (6/6) developed acute conjunctivitis. "CI" yielded more stromal involvement (1/6) and iritis (5/6), but lower clinical scores (area × severity). Infection via "C" was inconsistent (4/6). Fifty (50) ug/ml was effective against Ad-5 at 6x, 9x dosings while 25 ug/ml (6x) was only marginally effective. CONCLUSION: CTC-96 demonstrated virucidal activity against Ad5 in tissue culture with HeLa, A549 and SIRC cell lines. Animal Model Development: 1) "CC" produced conjunctival infection with occasional keratitis similar to human disease; "CI" yielded primarily stromal involvement; 2) "C" consistently produced neither conjunctivitis nor keratitis. CTC Testing: 1) Conjunctivitis in all eyes; 2) Resolution fastest in "50/9" ("50/9". "50/6" > "25/6" > "-"); 3) Efficacy in "50/6" was not statistically different than "50/9"; 4) Conjunctival severity was lower in treatment groups then controls; 5) Little corneal or intra-ocular changes were noted
Eosinophils are key regulators of perivascular adipose tissue and vascular functionality
Obesity impairs the relaxant capacity of adipose tissue surrounding the vasculature (PVAT) and has
been implicated in resultant obesity-related hypertension and impaired glucose intolerance. Resident
immune cells are thought to regulate adipocyte activity. We investigated the role of eosinophils in
mediating normal PVAT function. Healthy PVAT elicits an anti-contractile effect, which was lost in
mice deficient in eosinophils, mimicking the obese phenotype, and was restored upon eosinophil
reconstitution. Ex vivo studies demonstrated that the loss of PVAT function was due to reduced
bioavailability of adiponectin and adipocyte-derived nitric oxide, which was restored after eosinophil
reconstitution. Mechanistic studies demonstrated that adiponectin and nitric oxide are released after
activation of adipocyte-expressed β3 adrenoceptors by catecholamines, and identified eosinophils as
a novel source of these mediators. We conclude that adipose tissue eosinophils play a key role in the
regulation of normal PVAT anti-contractile function
Antioxidant Activity of the Phenolic Leaf Extracts from Monechma ciliatum in Stabilization of Corn Oil
The total phenolic content and the antioxidan potential of methanolic extract (ME), ethyl acetate extract (EAE), and hexane extract (HE) from Monechma ciliatum leaves (MCL) were evaluated. The Folin-Ciocalteu, b-carotene bleaching, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and the accelerated oxidation methods were used for evaluation. Both the extraction yield and the antioxidant activity (AOA) were strongly dependent on the solvent. Among the extracts, ME exhibited highest total phenolic compounds (TPC) and IC50 values for DPPH, followed by EAE and HE, respectively. Peroxide value (PV), anisidine value (AV) conjugated dienes (CD), and thiobarbituric acid reactive substances (TBARS) were taken as the parameters for evaluation of stabilization efficacy of MCL extracts and results revealed MCL to be a potent antioxidant for the stabilization of corn oil. As a general trend, increased AOA was observed for increased extract concentration. The predominant phenolic compounds identified by HPLC-DAD in MCL extracts were p-coumaric acid, vanillin and ferulic acid
Antioxidant Activity of the Phenolic Leaf Extracts from Monechma ciliatum in Stabilization of Corn Oil
The total phenolic content and the antioxidan potential of methanolic extract (ME), ethyl acetate extract (EAE), and hexane extract (HE) from Monechma ciliatum leaves (MCL) were evaluated. The Folin-Ciocalteu, b-carotene bleaching, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and the accelerated oxidation methods were used for evaluation. Both the extraction yield and the antioxidant activity (AOA) were strongly dependent on the solvent. Among the extracts, ME exhibited highest total phenolic compounds (TPC) and IC50 values for DPPH, followed by EAE and HE, respectively. Peroxide value (PV), anisidine value (AV) conjugated dienes (CD), and thiobarbituric acid reactive substances (TBARS) were taken as the parameters for evaluation of stabilization efficacy of MCL extracts and results revealed MCL to be a potent antioxidant for the stabilization of corn oil. As a general trend, increased AOA was observed for increased extract concentration. The predominant phenolic compounds identified by HPLC-DAD in MCL extracts were p-coumaric acid, vanillin and ferulic acid
IL-4Rα-Independent Expression of Mannose Receptor and Ym1 by Macrophages Depends on their IL-10 Responsiveness
IL-4Rα-dependent responses are essential for granuloma formation and host survival during acute schistosomiasis. Previously, we demonstrated that mice deficient for macrophage-specific IL-4Rα (LysMcreIl4ra−/lox) developed increased hepatotoxicity and gut inflammation; whereas inflammation was restricted to the liver of mice lacking T cell-specific IL-4Rα expression (iLckcreIl4ra−/lox). In the study presented here we further investigated their role in liver granulomatous inflammation. Frequencies and numbers of macrophage, lymphocyte or granulocyte populations, as well as Th1/Th2 cytokine responses were similar in Schistosoma mansoni-infected LysMcreIl4ra−/lox liver granulomas, when compared to Il4ra−/lox control mice. In contrast, a shift to Th1 responses with high IFN-γ and low IL-4, IL-10 and IL-13 was observed in the severely disrupted granulomas of iLckcreIl4ra−/lox and Il4ra−/− mice. As expected, alternative macrophage activation was reduced in both LysMcreIl4ra−/lox and iLckcreIl4ra−/lox granulomas with low arginase 1 and heightened nitric oxide synthase RNA expression in granuloma macrophages of both mouse strains. Interestingly, a discrete subpopulation of SSChighCD11b+I-A/I-EhighCD204+ macrophages retained expression of mannose receptor (MMR) and Ym1 in LysMcreIl4ra−/lox but not in iLckcreIl4ra−/lox granulomas. While aaMφ were in close proximity to the parasite eggs in Il4ra−/lox control mice, MMR+Ym1+ macrophages in LysMcreIl4ra−/lox mice were restricted to the periphery of the granuloma, indicating that they might have different functions. In vivo IL-10 neutralisation resulted in the disappearance of MMR+Ym1+ macrophages in LysMcreIl4ra−/lox mice. Together, these results show that IL-4Rα-responsive T cells are essential to drive alternative macrophage activation and to control granulomatous inflammation in the liver. The data further suggest that in the absence of macrophage-specific IL-4Rα signalling, IL-10 is able to drive mannose receptor- and Ym1-positive macrophages, associated with control of hepatic granulomatous inflammation
Studies of the Decay B+- -> D_CP K+-
We report studies of the decay B+- -> D_CP K+-, where D_CP denotes neutral D
mesons that decay to CP eigenstates. The analysis is based on a 29.1/fb data
sample of collected at the \Upsilon(4S) resonance with the Belle detector at
the KEKB asymmetric e+ e- storage ring. Ratios of branching fractions of
Cabibbo-suppressed to Cabibbo-favored processes involving D_CP are determined
to be B(B- -> D_1 K-)/B(B- -> D_1 pi-)=0.125 +- 0.036 +- 0.010 and B(B- -> D_2
K-)/B(B- -> D_2 pi-)=0.119 +- 0.028 +- 0.006, where indices 1 and 2 represent
the CP=+1 and CP=-1 eigenstates of the D0 - anti D0 system, respectively. We
also extract the partial rate asymmetries for B+- -> D_CP K+-, finding A_1 =
0.29 +- 0.26 +- 0.05 and A_2 = -0.22 +- 0.24 +- 0.04.Comment: 10 pages, 2 figures, submitted to Physical Review Letter
Modulation of epithelial immunity by mucosal fluid
Mucosal epithelial cells, including those at the ocular surface, resist infection by most microbes in vivo but can be susceptible to microbial virulence in vitro. While fluids bathing mucosal surfaces (e.g. tears) contain antimicrobials, potentially pathogenic microbes often thrive in these fluids, suggesting that additional mechanisms mediate epithelial resistance in vivo. Here, tear fluid acted directly upon epithelial cells to enhance their resistance to bacterial invasion and cytotoxicity. Resistance correlated with tear fluid-magnified activation of NFκB and AP-1 transcription factors in epithelial cells in response to bacterial antigens, suggesting priming of innate defense pathways. Further analysis revealed differential regulation of potential epithelial cell defense genes by tears. siRNA knockdown confirmed involvement of at least two factors, RNase7 and ST-2, for which tears increased mRNA levels, in protection against bacterial invasion. Thus, the role of mucosal fluids in defense can include modulation of epithelial immunity, in addition to direct effects on microbes
Aerosol optical thickness (AOT) retrieval over land using satellite image-based algorithm
Supercurrent reversal in quantum dots
When two superconductors become electrically connected by a weak link a
zero-resistance supercurrent can flow. This supercurrent is carried by Cooper
pairs of electrons with a combined charge of twice the elementary charge, e.
The 2e charge quantum is clearly visible in the height of Shapiro steps in
Josephson junctions under microwave irradiation and in the magnetic flux
periodicity of h/2e in superconducting quantum interference devices. Several
different materials have been used to weakly couple superconductors, such as
tunnel barriers, normal metals, or semiconductors. Here, we study supercurrents
through a quantum dot created in a semiconductor nanowire by local
electrostatic gating. Due to strong Coulomb interaction, electrons only tunnel
one-by-one through the discrete energy levels of the quantum dot. This
nevertheless can yield a supercurrent when subsequent tunnel events are
coherent. These quantum coherent tunnelling processes can result in either a
positive or a negative supercurrent, i.e. in a normal or a pi-junction,
respectively. We demonstrate that the supercurrent reverses sign by adding a
single electron spin to the quantum dot. When excited states of the quantum dot
are involved in transport, the supercurrent sign also depends on the character
of the orbital wavefunctions
Side Chain Hydrophobicity Modulates Therapeutic Activity and Membrane Selectivity of Antimicrobial Peptide Mastoparan-X
The discovery of new anti-infective compounds is stagnating and multi-resistant bacteria continue to emerge, threatening to end the "antibiotic era". Antimicrobial peptides (AMPs) and lipo-peptides such as daptomycin offer themselves as a new potential class of antibiotics; however, further optimization is needed if AMPs are to find broad use as antibiotics. In the present work, eight analogues of mastoparan-X (MPX) were investigated, having side chain modifications in position 1, 8 and 14 to modulate peptide hydrophobicity. The self-association properties of the peptides were characterized, and the peptide-membrane interactions in model membranes were compared with the bactericidal and haemolytic properties. Alanine substitution at position 1 and 14 resulted in higher target selectivity (red blood cells versus bacteria), but also decreased bactericidal potency. For these analogues, the gain in target selectivity correlated to biophysical parameters showing an increased effective charge and reduction in the partitioning coefficient for membrane insertion. Introduction of an unnatural amino acid, with an octyl side chain by amino acid substitution, at positions 1, 8 and 14 resulted in increased bactericidal potency at the expense of radically reduced membrane target selectivity. Overall, optimized membrane selectivity or bactericidal potency was achieved by changes in side chain hydrophobicity of MPX. However, enhanced potency was achieved at the expense of selectivity and vice versa in all cases
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