20 research outputs found

    Platelet-activating factor overturns the transcriptional repressor disposition of

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    PURPOSE. Matrix metalloproteinase (MMP)-9 is induced in corneal epithelial cells stimulated with platelet-activating factor (PAF), and interferes with the normal reepithelialization of wounded cornea. Here the transcriptional regulation of MMP-9 gene expression by PAF was investigated in human corneal epithelial cells (HCECs). METHODS. DNA-binding activity of NFB, Sp1, and AP-1 was determined in quiescent and PAF-stimulated HCECs by electrophoretic mobility shift assay (EMSA). A series of 5Ј deleted human MMP-9 promoter-luciferase reporter constructs was transiently transfected into HCECs, and luciferase activity was examined after stimulation with PAF. Mutagenesis and specific deletions of some elements in the MMP-9 promoter were also introduced and analyzed. Phosphorylation of Sp1 and MEK/ ERK pathway proteins was examined by Western blot analysis. Activation of Sp1 and MMP-9 was also determined by ELISA and zymography, respectively, in the absence or presence of the MEK inhibitor PD98059. RESULTS. DNA-binding activity of NFB, Sp1, and AP-1 was upregulated by PAF with a peak at 1 hour after stimulation. A region spanning -670 to -460 relative to the transcription start point was required for the induction of the MMP-9 promoter by PAF. Mutation of the -79AP-1 or -600NFB motif reduced the activity of MMP-9 promoter and the induction of gene expression by PAF. In untreated HCECs, mutation of the -558Sp1 motif upregulated gene expression, but it caused a significant decrease in the promoter activity induced by PAF. Inhibition of MEK activity eliminated the PAF-induced phosphorylation and activation of Sp1 and abolished the upregulation of MMP-9 expression and activity. CONCLUSIONS. These findings demonstrate that collaboration between several regulatory elements is required for the induction of MMP-9 promoter activity by PAF and that PAF overturns the repressor effect of Sp1 through activation of the MEK/ERK signaling cascade. (Invest Ophthalmol Vis Sci

    Numerical modeling of gas flow in coal pores for methane drainage

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    The sudden explosion of methane during underground coal mining is a major dilemma. To mitigate its occurrence and reduce the extent of methane diffusion, gas drainage operations are carried out before mining. This paper investigates methane gas flow in a coal block in order to calculate the pressure of gas and its molecule velocity for methane gas drainage operation. A coal piece surrounded by cleats was used for geometrical modeling and numerical simulation. Movements of fluid and gas molecules in a porous medium were successfully simulated. The numerical solution is based on COMSOL Multiphysics software. The validity of the numerical simulation was assessed using an analytical model with satisfactory results

    Frequency of IL-10+CD19+ B cells in patients with prostate cancer compared to patients with benign prostatic hyperplasia

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    Background: The function of the immune system in prostate cancer (PC) might promote carcinogenesis. PC is a common cancer in men. Regulatory B cells (Bregs) are a new subtype of B cells that have suppressive roles in the immune system. Interleukin-10 (IL-10) is a dominant mediator of immune suppression released by Bregs. Objective: The purpose of this research was to examine the frequency of CD19+IL10+ B cells and IL-10 mRNA expression in patients with PC compared to patients with benign prostatic hyperplasia (BPH). Methods: Forty paraffin tissue samples from patients with PC and 32 paraffin tissue samples from patients with BPH were entered in this study. The immunohistochemistry staining was used to evaluate the pattern expression of CD19 and IL-10 markers. IL-10 mRNA expression in fresh tissue was determined by real time-polymerase chain reaction (RT-PCR). Results: The frequency of CD19+IL-10+ B cells and IL-10 mRNA expression in PC patients were significantly higher than patients with BPH. Also, there was no meaningful relationship between the frequency of IL-10+CD19+ B cells and gleason scores in patients with PC. Conclusions: Our findings suggested that frequency of IL-10+CD19+ B cells correlates with progressive stage of PC

    Frequency of IL-10+CD19+ B cells in patients with prostate cancer compared to patients with benign prostatic hyperplasia

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    Background: The function of the immune system in prostate cancer (PC) might promote carcinogenesis. PC is a common cancer in men. Regulatory B cells (Bregs) are a new subtype of B cells that have suppressive roles in the immune system. Interleukin-10 (IL-10) is a dominant mediator of immune suppression released by Bregs. Objective: The purpose of this research was to examine the frequency of CD19+IL10+ B cells and IL-10 mRNA expression in patients with PC compared to patients with benign prostatic hyperplasia (BPH). Methods: Forty paraffin tissue samples from patients with PC and 32 paraffin tissue samples from patients with BPH were entered in this study. The immunohistochemistry staining was used to evaluate the pattern expression of CD19 and IL-10 markers. IL-10 mRNA expression in fresh tissue was determined by real time-polymerase chain reaction (RT-PCR). Results: The frequency of CD19+IL-10+ B cells and IL-10 mRNA expression in PC patients were significantly higher than patients with BPH. Also, there was no meaningful relationship between the frequency of IL-10+CD19+ B cells and gleason scores in patients with PC. Conclusions: Our findings suggested that frequency of IL-10+CD19+ B cells correlates with progressive stage of PC

    Simulation of macerals effects on methane emission during gas drainage in coal mines

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    The methane found in coal is regarded as one of the clean energy resources. Methane forms inside coal beds according to geological conditions through coalification. The lifecycle of coalification and source of coal formation directly affect macerals. Coal is classified based on its maceral content. In this study, firstly macerals were identified in coal samples from two different mines. Then, the permeability of each sample was measured. Subsequently, parameters obtained from experiments were introduced as input numerical data into COMSOL Multiphysics commercial software. This study was intended to measure the impact of macerals on the level of methane emission in an attempt to remove gas from coal beds. It was found that vitrinite levels in Tabas and Shahrood mines coal were 81.34% and 69.31% respectively. The methane emission rate was 0.00269 m/s in Tabas coal and 0.00258 m/s in Shahrood coal, a variation of 12% increase in vitrinite. The increase in vitrinite content in Tabas Mine has contributed to the rate of emission increase by about 0.00011 m/s or 0.66 m3/min. This variation in methane emission was due to the maceral content

    Characterization of Rigid Polyurethane Foam Prepared from Recycling of PET Waste

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    Poly (ethylene terephthalate) (PET) waste bottles were recycled to prepare RPUFs (rigid polyurethane foams) by using propylene glycol (PG) in different glycol/polymer molar ratios. The glycolysis products were characterized, after that, they reacted with poly methylene diphenyl diisocyanate (PMDI) in the presence of blowing, co-blowing and second blowing agents to produce the RPUFs. The prepared foams were characterized and compared to foam that is produced by original polyol. It was found that the glycolysis products have possibility for the fabrication of RPUFs with proper properties depending on the blowing agent type and density, also they have similar thermal stability compared to that one produced by original polyol. This may provide an advantage in the future planning for recycling of PET bottles to enhance the mechanical and thermal properties of PU

    Characterization of Rigid Polyurethane Foam Prepared from Recycling of PET Waste

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    Correlation between aryl hydrocarbon receptor and IL-17(+) and Foxp3(+) T-cell infiltration in bladder cancer

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    Bladder cancer (BC) is one of the most prevalent cancers around the world and, if not treated well, has high morbidity and mortality. Many studies have indicated that there may be various roles for the aryl hydrocarbon receptor (AHR) in the immune system. The aim of this study was to determine the frequency of Foxp3(+) regulatory T (Treg) and T helper 17 cells (Th17) in BC tissue in comparison with controls and determine the relationship between AHR, Foxp3(+) Treg and Th17 cells in BC. A total of 40 patients with BC were enrolled in this study. The control group was selected from non-tumoural parts of bladder tissues from the patients who have undergone cystoscopy. The percentage of regulatory T cells (Foxp3(+)/CD4(+)) and Th17 (IL-17(+)/CD4(+)), as well as AHR(+) cells in BC tissues and controls, were determined by immunohistochemistry. The results of this study showed that the number of Foxp3(+) Treg and Th17 is significantly higher in bladder tumour tissues in comparison with non-tumoural tissues. Also, the percentage of AHR(+) lymphocytes and AHR(+) cells was increased significantly in bladder tumour tissues rather than non-tumoural tissues. This study also found a relation between AHR and Foxp3(+)/CD4(+) T lymphocytes ratio cells in BC. The percentage of Foxp3(+) Tregs and AHR(+) cells were significantly correlated with the grade and stage of BC. An increase in the percentage of Foxp3(+) Treg and Th17 cells may play an important role in tumour immunity; and determining the relationship between AHR and differentiation of Th17/Foxp3(+)Treg in BC can lead to a potential cancer therapeutic possibility
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