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101.
102.
Plasmonics - We demonstrate a novel, label-free and real-time tunable infrared biosensor by employing surface-plasmon polaritons in asymmetric Mach–Zehnder interferometer. The waveguides... 相似文献
103.
Bahareh Hakiminia Arash Goudarzi Azadeh Moghaddas 《Journal of biochemical and molecular toxicology》2019,33(8)
Cisplatin is one of the highly consumed and effective antitumor agents whose clinical application is accompanied by nephrotoxicity adverse reaction. Also, other complications such as ototoxicity and hepatotoxicity are a matter of concern. Today, it is suggested that cisplatin‐associated toxicities are mainly induced by free radicals production, which will result in oxidative organ injury. The evidence is growing over the protective effects of antioxidants on cisplatin‐induced adverse reactions especially nephrotoxicity. The possible protective effects of vitamin E and its derivative in cisplatin‐induced nephrotoxicity and ototoxicity are reviewed here at the light of pertinent results from basic and clinical research. Administration of vitamin E alone or in combination with other antioxidant agents could cause amelioration in oxidative stress biomarkers such as decreasing the level of malondialdehyde, reducing serum urea and creatinine, and also enhancing the activities of renal antioxidant enzymes including renal catalase, glutathione‐S‐transferase, and superoxide dismutase. Although the data from most of the studies are in favors of protective effects of vitamin E against cisplatin‐induced toxicity, more clinical trials are needed to clarify the clinical importance of vitamin E administration as an antioxidant during cisplatin therapy in cancer condition. 相似文献
104.
MexAB-OprM is known to pump out mostly lipophilic and amphiphilic drugs. But in low-ionic-strength medium, nutrient broth (NB), this pump has been shown to contribute to hydrophilic antibiotic (aminoglycosides) resistance, via active efflux. The association of the MexAB-OprM efflux system to aminoglycosides resistance inPseudomonas aeruginosa were assessed using a drug susceptibility test carried out in NB, in presence and absence of protonophore, carbonyl cyanide m-chlorophenyl hydrazone (CCCP) by 23 multidrug resistant strains were selected from 104 clinical isolates ofP. aeruginosa. Active efflux was assessed using EtBr accumulation assays. PCR was used to identify themexAB-oprM and MexAB-OprM-dependent efflux of aminoglycosides and the results were confirmed by continuous fluorescence assay. A multidrug resistant mutant ofmexAB-oprM, derivative of PAO1, was selected by ciprofloxacin and subjected to the same analysis as described above for the clinical isolates. In this study, CCCP reduced the level of MICs in at least 1 dilution. Ethidium bromide accumulation assays confirmed the presence of efflux mechanism in all clinical isolates and PCR demonstrated that 17% of our isolates had themexAB-oprM operon. Results of aminoglycosides accumulation showed, in addition to amphiphilic antibiotics in NB medium, MexAB-OprM extrudes aminoglycosides (hydrophilic) drugs. 相似文献
105.
Inhibition of amyloid fibrillation of lysozyme by indole derivatives--possible mechanism of action 总被引:1,自引:0,他引:1
Morshedi D Rezaei-Ghaleh N Ebrahim-Habibi A Ahmadian S Nemat-Gorgani M 《The FEBS journal》2007,274(24):6415-6425
Amyloid aggregation of polypeptides is related to a growing number of pathologic states known as amyloid disorders. There is a great deal of interest in developing small molecule inhibitors of the amyloidogenic processes. In the present article, the inhibitory effects of some indole derivatives on amyloid fibrillation of hen egg white lysozyme (HEWL) are reported. Acidic pH and high temperatures were used to drive HEWL towards amyloid formation. A variety of techniques, ranging from thioflavin T fluorescence and Congo red absorbance assays to far-UV CD and transmission electron microscopy, were employed to characterize the HEWL fibrillation process. Among the indole derivatives tested, indole 3-acetic acid, indole 3-carbinol and tryptophol had the most inhibitory effects on amyloid formation, indole and indole 3-propionic acid gave some inhibition, and indole aldehyde and tryptophan showed no significant inhibition. Although indoles did not protect the HEWL native state from conformational changes, they were effective in diminishing HEWL amyloid fibril formation, delaying both the nucleation and elongation phases. Disaggregation of previously formed HEWL amyloid fibrils was also enhanced by indole 3-acetic acid. Various medium conditions, such as the presence of different anions and alcoholic cosolvents, were explored to gain an insight into possible mechanisms. These observations, taken together, suggest that the indole ring is likely to play the main role in inhibition and that the side chain hydroxyl group may contribute positively, in contrast to the side chain carbonyl and intervening methylene groups. 相似文献
106.
Moosavi MA Yazdanparast R Lotfi A 《The international journal of biochemistry & cell biology》2007,39(9):1685-1697
Since differentiation therapy is one of the promising strategies for treatment of leukemia, universal efforts have been focused on finding new differentiating agents. In that respect, it was recently shown that guanosine 5'-triphosphate (GTP) induced the differentiation of K562 cells, suggesting its possible efficiency in treatment of chronic myelogenous leukemia (CML). However, further investigations are required to verify this possibility. Here, the effects of GTP on activation of mitogen-activated protein kinases (MAPKs) and caspases in K562 cells were examined. Exposure of K562 cells to 100muM GTP markedly inhibited growth (4-70%) and increased percent glycophorin A positive cells after 1-6 days. GTP-induced terminal erythroid differentiation of K562 cells was accompanied with activation of three key caspases, i.e., caspase-3, -6 and -9. More detailed studies revealed that mitochondrial pathway is activated along with down-regulation of Bcl-xL and releasing of cytochrome c into cytosol. Among MAPKs, ERK1/2and p38 were modulated after GTP treatment. Western blot analyses showed that sustained phosphorylation of p38 MAPK was accompanied by a decrease in ERK1/2 activation. These modulatory effects of GTP were observed at early exposure times before the onset of differentiation (3h), and followed for 24-96h. Interestingly, inhibition of p38 MAPK pathway by SB202190 impeded GTP-mediated caspases activation and differentiation in K562 cells, suggesting that p38 MAPK may act upstream of caspases in our system. These results point to a pivotal role for p38 MAPK pathway during GTP-mediated erythroid differentiation of K562 cells and will hopefully have important impact on pharmaceutical evaluation of GTP for CML treatment in differentiation therapy approaches. 相似文献
107.
108.
Jia H Bagherzadeh A Hartzoulakis B Jarvis A Löhr M Shaikh S Aqil R Cheng L Tickner M Esposito D Harris R Driscoll PC Selwood DL Zachary IC 《The Journal of biological chemistry》2006,281(19):13493-13502
Neuropilin-1 (NP-1) is a receptor for vascular endothelial growth factor-A165 (VEGF-A165) in endothelial cells. To define the role of NP-1 in the biological functions of VEGF, we developed a specific peptide antagonist of VEGF binding to NP-1 based on the NP-1 binding site located in the exon 7- and 8-encoded VEGF-A165 domain. The bicyclic peptide, EG3287, potently (K(i) 1.2 microM) and effectively (>95% inhibition at 100 microM) inhibited VEGF-A165 binding to porcine aortic endothelial cells expressing NP-1 (PAE/NP-1) and breast carcinoma cells expressing only NP-1 receptors for VEGF-A, but had no effect on binding to PAE/KDR or PAE/Flt-1. Molecular dynamics calculations, a nuclear magnetic resonance structure of EG3287, and determination of stability in media, indicated that it constitutes a stable subdomain very similar to the corresponding region of native VEGF-A165. The C terminus encoded by exon 8 and the three-dimensional structure were both critical for EG3287 inhibition of NP-1 binding, whereas modifications at the N terminus had little effect. Although EG3287 had no direct effect on VEGF-A165 binding to KDR receptors, it inhibited cross-linking of VEGF-A165 to KDR in human umbilical vein endothelial cells co-expressing NP-1, and inhibited stimulation of KDR and PLC-gamma tyrosine phosphorylation, activation of ERKs1/2 and prostanoid production. These findings characterize the first specific antagonist of VEGF-A165 binding to NP-1 and demonstrate that NP-1 is essential for optimum KDR activation and intracellular signaling. The results also identify a key role for the C-terminal exon 8 domain in VEGF-A165 binding to NP-1. 相似文献
109.
Azadeh Askarinejad 《Inorganica chimica acta》2006,359(10):3379-3383
A three-dimensional polymeric KITlI heterometallic compound [K2Tl(μ-C4H4O4)(μ-NO3)]n, with mixes succinate and nitrate ligands, has been synthesized and characterized. Its single-crystal X-ray structure shows two types of K+-ions with coordination numbers of seven and eight and one Tl+-ion with a coordination number of five. However, the arrangement of O-atoms for TlI suggests a gap or hole in the coordination geometry around this atom. This ‘hole’ is possibly occupied by a stereochemically ‘active’ electron lone pair of thallium atoms. Two hydrogen atoms of succinate situated 3.26 Å above the proposed site on the lone pair of TlI is oriented in such a way that it might be thought to be forming weak Tl-Lp?H-C hydrogen bond or agostic interactions, thus attaining of environment TlO5H2. 相似文献
110.
Adlane Ould-yahoui Evelyne Tremblay Oualid Sbai Lotfi Ferhat Anne Bernard Eliane Charrat Yatma Gueye Ngee Han Lim Keith Brew Jean-Jacques Risso Vincent Dive Michel Khrestchatisky Santiago Rivera 《PloS one》2009,4(12)