20 research outputs found
Reconsidering the Relationship between Oil Prices and Industrial Production: Testing for Cointegration in some of the OECD Countries
This paper investigates the effects of crude oil prices on the industrial production for some of the OECD countries. According to it, the empirical results sign that there is statistical meaningful short term causality from crude oil price to industrial production in all countries except France. In France however, causality is from industrial production to oil price in short run. The error correction mechanism is run for US. The causality is from oil price to industrial production in long run for US. These results show us that oil prices do affect industrial production index. Another interesting finding that, similar results were observed for oil exporting and importing countries such as Saudi Arabia and Iran as well. This situation is important that firm sensitivity towards oil price shows a similarity among the countries
Multifunctional nanoâbiointerfaces: cytocompatible antimicrobial nanocarriers from stabilizerâfree cubosomes
The rational design of alternative antimicrobial materials with reduced toxicity toward mammalian cells is highly desired due to the growing occurrence of bacteria resistant to conventional antibiotics. A promising approach is the design of lipidâbased antimicrobial nanocarriers. However, most of the commonly used polymerâstabilized nanocarriers are cytotoxic. Herein, the design of a novel, stabilizerâfree nanocarrier for the human cathelicidin derived antimicrobial peptide LLâ37 that is cytocompatible and promotes cell proliferation for improved wound healing is reported. The nanocarrier is formed through the spontaneous integration of LLâ37 into novel, stabilizerâfree glycerol monoâoleate (GMO)âbased cubosomes. Transformations in the internal structure of the cubosomes from Pn3m to Im3mâtype and eventually their transition into small vesicles and spherical micelles are demonstrated upon the encapsulation of LLâ37 into their internal bicontinuous cubic structure using small angle Xâray scattering, cryogenic transmission electron microscopy, and light scattering techniques. Additional in vitro biological assays show the antimicrobial activity of the stabilizerâfree nanoâobjects on a variety of bacteria strains, their cytocompatibility, and cellâ proliferation enhancing effect. The results outline a promising strategy for the comprehensive design of antimicrobial, cytocompatible lipid nanocarriers for the protection and delivery of bioactive molecules with potential for application as advanced wound healing materials
Postantibiotic Effects of Tigecycline, Colistin Sulfate, and Levofloxacin Alone or Tigecycline-Colistin Sulfate and Tigecycline-Levofloxacin Combinations against Acinetobacter baumannii
Background: Colistin sulfate and levofloxacin, alone and in combination with tigecycline, were investigated for their in vitro activities and postantibiotic effects (PAEs) on 6 meropenem-resistant Acinetobacter baumannii. Methods: The in vitro activities of colistin sulfate and levofloxacin in combination with tigecycline were determined using a microbroth checkerboard technique. The results were interpreted based on the fractional inhibitory concentration index. To determine the PAEs, A. baumannii strains in the logarithmic phase of growth were exposed for 1 h to antibiotics, alone and in combination. Recovery periods of test cultures were evaluated using viable counting after centrifugation. Results: One synergistic interaction was observed for each of the tigecycline-colistin sulfate and tigecycline-levofloxacin combinations. Colistin sulfate produced a strong PAE ranging from 2.50 to 7.0 h in a concentration-dependent manner. PAEs were induced by levofloxacin (ranging from 0.35 to 2.45 h) and tigecycline (ranging from 0.05 to 1.40 h). In combination, tigecycline slightly changed the PAE of colistin sulfate and levofloxacin against the studied strains. Conclusion: This study's findings could have important implications for the timing of doses during antimicrobial therapy with tigecycline, colistin sulfate, and levofloxacin alone and in combination. copyright (C) 2010 S. Karger AG, Base
Designing an intracellular fluorescent probe for glutathione: two modulation sites for selective signal transduction
A selective probe for glutathione was designed and synthesized. The design incorporates spatial and photophysical constraints for the maximal emission signal. Thus, pHs, as well as the intracellular thiol concentrations, determine the emission signal intensity through a tight control of charge-transfer and PeT processes. The probe works satisfactorily inside the human breast adenocarcinoma cells, highlighting GSH distribution in the cytosol
General characteristics and therapeutic options in lung cancer in Turkey
WOS: 00045197940620
Angiogenic Peptide Nanofibers Improve Wound Healing in STZ-Induced Diabetic Rats
Low
expressions of angiogenic growth factors delay the healing
of diabetic wounds by interfering with the process of blood vessel
formation. Heparin mimetic peptide nanofibers can bind to and enhance
production and activity of major angiogenic growth factors, including
VEGF. In this study, we showed that heparin mimetic peptide nanofibers
can serve as angiogenic scaffolds that allow slow release of growth
factors and protect them from degradation, providing a new therapeutic
way to accelerate healing of diabetic wounds. We treated wounds in
STZ-induced diabetic rats with heparin mimetic peptide nanofibers
and studied repair of full-thickness diabetic skin wounds. Wound recovery
was quantified by analyses of re-epithelialization, granulation tissue
formation and blood vessel density, as well as VEGF and inflammatory
response measurements. Wound closure and granulation tissue formation
were found to be significantly accelerated in heparin mimetic gel
treated groups. In addition, blood vessel counts and the expressions
of alpha smooth muscle actin and VEGF were significantly higher in
bioactive gel treated animals. These results strongly suggest that
angiogenic heparin mimetic nanofiber therapy can be used to support
the impaired healing process in diabetic wounds
Norrin mediates angiogenic properties via the induction of insulin-like growth factor-1
Norrin is an angiogenic signaling molecule that activates canonical Wnt/beta-catenin signaling, and is involved in capillary formation in retina and brain. Moreover, Norrin induces vascular repair following an oxygen-induced retinopathy (OIR), the model of retinopathy of prematurity in mice. Since insulin-like growth factor (IGF)-1 is a very potent angiogenic molecule, we investigated if IGF-1 is a downstream mediator of Norrin's angiogenic properties. In retinae of transgenic mice with an ocular overexpression of Norrin (beta B1-Norrin), we found at postnatal day (P)11 a significant increase of IGF-1 mRNA compared to wild-type littermates. In addition, after treatment of cultured Muller cells or dermal microvascular endothelial cells with Norrin we observed an increase of IGF-1 and its mRNA, an effect that could be blocked with DKK-1, an inhibitor of Wnt/beta-catenin signaling. When OIR was induced, the expression of IGF-1 was significantly suppressed in both transgenic beta B1-Norrin mice and wild-type littermates when compared to wild-type animals that were housed in room air. Furthermore, at P13, one day after the mice had returned to normoxic conditions, IGF-1 levels were significantly higher in transgenic mice compared to wild-type littermates. Finally, after intravitreal injections of inhibitory alpha-IGF-1 antibodies at P12 or at P12 and P14, the Norrin-mediated vascular repair was significantly attenuated. We conclude that Norrin induces the expression of IGF-1 via an activation of the Wnt/beta-catenin signaling pathway, an effect that significantly contributes to the protective effects of Norrin against an OIR. (C) 2015 Elsevier Ltd. All rights reserved
Inhibition of VEGF mediated corneal neovascularization by anti-angiogenic peptide nanofibers
Atypical angiogenesis is one of the major symptoms of severe eye
diseases, including corneal neo-vascularization, and the complex nature
of abnormal vascularization requires targeted methods with high
biocompatibility. The targeting of VEGF is the most common approach for
preventing angiogenesis, and the LPPR peptide sequence is known to
strongly inhibit VEGF activity by binding to the VEGF receptor
neuropilin-1. Here, the LPPR epitope is presented on a peptide
amphiphile nanofiber system to benefit from multivalency and increase
the anti-angiogenic function of the epitope. Peptide amphiphile
nanofibers are especially useful for ocular delivery applications due to
their ability to remain on the site of interest for extended periods of
time, facilitating the long-term presentation of bioactive sequences.
Consequently, the LPPR sequence was integrated into a self-assembled
peptide amphiphile network to increase its efficiency in the prevention
of neovascularization. Anti-angiogenic effects of the peptide nanofibers
were investigated by using both in vitro and in vivo models. LPPR-PA
nanofibers inhibited endothelial cell proliferation, tube formation, and
migration to a greater extent than the soluble LPPR peptide in vitro. In
addition, the LPPR-PA nanofiber system led to the prevention of vascular
maturation and the regression of angiogenesis in a suture-induced
corneal angiogenesis model. These results show that the anti-angiogenic
activity exhibited by LPPR peptide nanofibers may be utilized as a
promising approach for the treatment of corneal angiogenesis. (C) 2016
Elsevier Ltd. All rights reserved
Identification of novel inhibitors of the ABC transporter BmrA
International audienceThe resistance of microbes to commonly used antibiotics has become a worldwide health problem. A major underlying mechanism of microbial antibiotic resistance is the export of drugs from bacterial cells. Drug efflux is mediated through the action of multidrug resistance efflux pumps located in the bacterial cell membranes. The critical role of bacterial efflux pumps in antibiotic resistance has directed research efforts to the identification of novel efflux pump inhibitors that can be used alongside antibiotics in clinical settings. Here, we aimed to find potential inhibitors of the archetypical ATP-binding cassette (ABC) efflux pump BmrA of Bacillus subtilis via virtual screening of the Mu.Ta.Lig. Chemotheca small molecule library. Molecular docking calculations targeting the nucleotide-binding domain of BmrA were performed using AutoDock Vina. Following a further drug-likeness filtering step based on Lipinskiâs Rule of Five, top 25 scorers were identified. These ligands were then clustered into separate groups based on their contact patterns with the BmrA nucleotide-binding domain. Six ligands with distinct contact patterns were used for further in vitro inhibition assays based on intracellular ethidium bromide accumulation. Using this methodology, we identified two novel inhibitors of BmrA from the Chemotheca small molecule library