928 research outputs found
Expression levels of vascular endothelial growth factors A and C in patients with peptic ulcers and gastric cancer
Purpose: Vascular endothelial growth factor (VEGF) is one of the most important growth factors for metastatic tumors. To clarify the role of VEGF-A and C in patients with peptic ulcer disease (PUD) or gastric cancer (GC), we evaluated the expression levels of these two molecules. We also analyzed the effect of Helicobacter pylori infection on VEGF-A and C expression levels
Increased expression of two alternative spliced variants of CD1d molecule in human gastric cancer
Background: CD1d presents glycolipid antigens to invariant natural killer T (iNKT) cells. The role of CD1d in the development of peptic ulcer and gastric cancer has not been revealed, yet. Objective: To clarify the expression of alternatively spliced variants of CD1d in peptic ulcer and gastric cancer. Methods: Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC), according to their endoscopic and histopathological examinations. H. pylori infection was diagnosed by rapid urease test and histopathology. The expression levels of V2, V4, and V5 spliced variants of CD1d molecule were determined by quantitative Reverse Transcriptase PCR. Results: Relative gene expression levels of V4 were higher in GC patients (n=37) than those in NUD (n=49) and PUD (n=51) groups (p<0.05 and p<0.01, respectively). Moreover, GC patients showed higher expression levels of V5 compared to NUD and PUD groups (p<0.001 and p<0.001, respectively). Positive correlation coefficients were attained between V4 and V5 expression in patients with PUD (r=0.734, p<0.0001) and GC (r=0.423, p<0.01), but not in patients with NUD. Among NUD patients, the expression levels of V4, but not V5, were higher in H. pylori-positive patients than in H. pylori-negative ones (p<0.01). Conclusion: Collectively, both membrane-bound (V4) and soluble (V5) isoforms of CD1d were over-expressed in gastric tumor tissues, suggesting that they are involved in anti-tumor immune responses. © 2015, Shiraz University of Medical Sciences. All rights reserved
Effect of chlorhexidine on the shear bond strength of self-etch adhesives to dentin
The aim of this study was to investigate the effect of chlorhexidine on shear bond strength of self-etch adhesives to dentin. The crowns of 60 sound human premolars were horizontally sectioned to expose the coronal dentin. Dentin surfaces were polished with 320 grit silicon carbide papers, and were randomly divided into 4 groups (n = 15). In group 1, two-step self-etch adhesive resin (Clearfil SE Bond) was used. In group 2, the surface was rinsed with chlorhexidine 2% solution prior to Clearfil SE bond application. In groups 3 and 4, the procedure was repeated similar to groups 1 and 2. In this case, onestep self-etch adhesive resin (Clearfil S3 Bond) was used. Then Z100 composite resin was applied. Subsequent to thermocycling, the shear bond strengths were measured. Data were analyzed using oneway ANOVA. In this study, p < 0.05 was considered significant. There were no significant differences between groups (p = 0.321). The use of 2% chlorhexidine had no effect on the shear bond strength of two-step and one-step self-etching adhesive resins. Moreover, there was no significant difference in the shear bond strength values between two-step and one-step self-etching adhesive resins.Key words: Chlorhexidine, shear bond strength, one-step self-etch adhesive resin, two-step self-etch adhesive resin
Comparative analysis of the Mexican and Turkish currency crises
Author's OriginalThe study aims to explore characteristics of currency crises in emerging markets. Two recent experiences in Mexico and Turkey respectively analyzed carefully to identify common elements in the development and eruption of the crises. Results of the study suggest that there are several background factors and triggers that were consistent in both cases. Finally a discussion of the policy implications of the findings concludes the study.Aybar, C., Ajami, R., & Bear, M. (2000). Currency crises in emerging markets: A comparative analysis of the Mexican and Turkish cases. International Journal of Public Administration, 23(5-8), 963-1006
Impact of hepcidin antimicrobial peptide on iron overload in tuberculosis patients
Background: Iron acquisition is essential for the growth of Mycobacterium tuberculosis. Hepcidin is known as an antimicrobial peptide and a component of the innate immune response. Hepcidin inhibits M. tuberculosis growth in vitro. In this study, we decided to identify-582A> G variants of the HAMP promoter in patients with tuberculosis (TB) and investigate its effect on serum iron, ferritin, and hepcidin levels. Methods: The sample population consisted of 105 patients with TB and 104 healthy individuals. The-582A> G polymorphism was genotyped using a tetra-primers PCR set. Serum levels of hepcidin were determined using an ELISA kit. Statistical analysis was performed using SPSS software. Results: The G allele is meaningfully associated with TB disease (95% confidence interval = 2-4.8, p G polymorphism genotypes. There was significant reverse correlation between hepcidin and iron (r =-0.849, p = 0.006). Conclusion: A high association was found between serum hepcidin levels and the HAMP-582A> G variants in patients with TB. These observations indicate a hypothetical role of this polymorphism in iron metabolism. Hepcidin could perhaps be an option for the treatment of TB. © 2014 Informa Healthcare
Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers
Electronic structures and optical excitations in Moebius conjugated polymers
are studied theoretically. Periodic and Moebius boundary conditions are applied
to the tight binding model of poly(para-phenylene), taking exciton effects into
account. We discuss that oligomers with a few structural units are more
effective than polymers for observations of effects of discrete wave numbers
that are shifted by the change in boundary condition. Next, calculations of
optical absorption spectra are reported. Certain components of optical
absorption for an electric field perpendicular to the polymer axis mix with
absorption spectra for an electric field parallel to the polymer axis.
Therefore, the polarization dependences of an electric field of light enable us
to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74
No. 2 (February, 2005), Letter sectio
Selective cell response on natural polymer bio-interfaces textured by femtosecond laser
This study reports on the evaluation of laser processed natural polymer-chitosan, which is under consideration as a biointerface used for temporary applications as skin and cartilage substitutes. It is employed for tissue engineering purposes, since it possesses a significant degree of biocompatibility and biodegradability. Chitosan-based thin films were processed by femtosecond laser radiation to enhance the surface properties of the material. Various geometry patterns were produced on polymer surfaces and employed to examine cellular adhesion and orientation. The topography of the modified zones was observed using scanning electron microscopy and confocal microscopy. Test of the material cytotoxicity was performed by evaluating the life/dead cell correlation. The obtained results showed that texturing with femtosecond laser pulses is appropriate method to initiate a predefined cellular response. Formation of surface modifications in the form of foams with an expansion of the material was created under laser irradiation with a number of applied laser pulses from N = 1-5. It is shown that irradiation with N > 5 results in disturbance of microfoam. Material characterization reveals a decrease in water contact angle values after laser irradiation of chitosan films. Consequently, changes in surface roughness of chitosan thin-film surface result in its functionalization. Cultivation of MC3T3 and ATMSC cells show cell orientational migration concerning different surface patterning. The influence of various pulse durations (varying from tau = 30-500 fs) over biofilms surface was examined regarding the evolution of surface morphology. The goal of this study was to define the optimal laser conditions (laser energy, number of applied pulses, and pulse duration) to alter surface wettability properties and porosity to improve material performance. The acquired set of results indicate the way to tune the surface properties to optimize cell-interface interaction
Plasma oxysterol level in patients with coronary artery stenosis and its changes in response to the treatment with atorvastatin
Background: Considering the increasing incidence of coronary artery stenosis and its related complications, the importance of its etiology and inconsistent reports we aimed to determine the relationship between oxysterol, serum levels and severity of coronary atherosclerosis and effect of statins on oxysterol. Methods: A total of 85 patients referred to Taleghani Hospital, Tehran, Iran during 2011-2012 with coronary artery stenosis more than 75, as determined by angiography, participated in the current study. Their demographic information and history of smoking and taking atorvastatin was carefully recorded. Two milliliters of venous blood was obtained from each patient. The serum oxysterol level of samples was measured using the enzyme-linked immunosorbent assay (ELISA) method. Statistical analysis was performed using SPSS v.19. Results: Eighty five patients completed the study. Mean age of patients was 64.4 years; 51 (60) were male; 55 (68) had acute coronary syndrome and 30 (32) had chronic stable angina. Mean±SD of plasma level of oxysterol was 24.8±0.2 pmol/ml. The normal range of oxysterol level was 13pmol/ml. Mean±SD of plasma oxysterol level in patients under statin therapy was 24.4±2.1 pmol/ml. In patients without receiving statins, plasma oxysterol level was 26.38±1.6pmol/ml. Conclusion: Findings of the present study indicated significant correlation between serum oxysterol and severity of coronary artery stenosis. It also demonstrated that receiving atorvastatin is associated with significant reduction of plasma oxysterol level
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