148 research outputs found

    Electrophysiological and molecular mechanisms of protection by iron sucrose against phosphine-induced cardiotoxicity: A time course study

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    The present study was designed for determining the exact mechanism of cytotoxic action of aluminum phosphide (AlP) in the presence of iron sucrose as the proposed antidote. Rats received AlP (12 mg/kg) and iron sucrose (5-30 mg/kg) in various sets and were connected to cardiovascular monitoring device. After identification of optimum doses of AlP and iron sucrose, rats taken in 18 groups received AlP (6 mg/kg) and iron sucrose (10 mg/kg), treated at six different time points, and then their hearts were surgically removed and used for evaluating a series of mitochondrial parameters, including cell lipid peroxidation, antioxidant power, mitochondrial complex activity, ADP/ATP ratio and process of apoptosis. ECG changes of AlP poisoning, including QRS, QT, P-R, ST, BP and HR were ameliorated by iron sucrose (10 mg/kg) treatment. AlP initiated its toxicity in the heart mitochondria through reducing mitochondrial complexes (II, IV and V), which was followed by increasing lipid peroxidation and the ADP/ATP ratio and declining mitochondrial membrane integrity that ultimately resulted in cell death. AlP in acute exposure (6 mg/kg) resulted in an increase in hydroxyl radicals and lipid peroxidation in a time-dependent fashion, suggesting an interaction of delivering electrons of phosphine with mitochondrial respiratory chain and oxidative stress. Iron sucrose, as an electron receiver, can compete with mitochondrial respiratory chain complexes and divert electrons to another pathway. The present findings supported the idea that iron sucrose could normalize the activity of mitochondrial electron transfer chain and cellular ATP level as vital factors for cell escaping from AlP poisoning. © 2015 Informa Healthcare USA, Inc. All rights reserved

    Evaluating the Effects of Blade Tip Clearance in Various Stages on the Performance of an Axial Compressor

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    In the current study, the influence of blade tip clearance in different stages of a three-stage compressor is investigated. Performance diagrams of compressor were verified against experiment when there is no change in the tip clearance, after which the effect of tip clearance for the cases, 1, 1.5 and 2 mm, in the first, second and third stages of rotor was studied. The results indicated that the impact of tip clearance increase did not have any effect on choked flow rate value in the first and second stages, and only the change in the third stage tip clearance reduced the choked flow rate. For the same tip clearance value, the highest compressor performance loss occurs in the case of applying the tip clearance in the third stage, which is also the final stage and is highly sensitive to tip clearance changes. Moreover, modifying the tip clearance is effective on the flow angle in the trailing edge and as the tip clearance increases, the same thing happens about the flow angle. The maximum value of flow angle changes by modifying the tip clearance belongs to the third stage of the compressor

    Molecular and biochemical evidence on the protection of cardiomyocytes from phosphine-induced oxidative stress, mitochondrial dysfunction and apoptosis by acetyl-l-carnitine

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    The aim of the present study was to investigate the efficacy of acetyl-l-carnitine (ALCAR) on pathologic changes of mitochondrial respiratory chain activity, ATP production, oxidative stress, and cellular apoptosis/necrosis induced by aluminum phosphide (AlP) poisoning. The study groups included: the Sham that received almond oil only; the AlP that received oral LD50 dose of aluminum; the AC-100, AC-200, and AC-300 which received concurrent oral LD50 dose of AlP and single 100, 200, and 300mg/kg of ALCAR by intraperitoneal injection. After 24h, the rats were sacrificed; the heart and blood sample were taken for measurement of biochemical and mitochondrial factors. The results specified that ALCAR significantly attenuated the oxidative stress (elevated ROS and plasma iron levels) caused by AlP poisoning. ALCAR also increased the activity of cytochrome oxidase, which in turn amplified ATP production. Furthermore, flow cytometric assays and caspase activity indicated that ALCAR prohibited AlP-induced apoptosis in cardiomyocytes. © 2015 Elsevier B.V.

    Air Entrainment in Skimming Flow on Stepped Spillways: the Effect of an Abrupt Slope Change

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    Numerous stepped spillways were built during the last decades. In particular, a stepped spillway may be integrated economically into the downstream face of a RCC gravity dam, or on valley flanks besides embankment or rockfill dams, where slope changes may naturally be implemented due to topography and economic reasons. This paper presents and discusses preliminary results on the air entrainment in the vicinity of an abrupt change chute slope, namely the air concentration distribution and the mean air concentration. A significant influence was observed on the air entrainment pattern, with a decrease of the mean air concentration immediately upstream of the slope change, followed by a marked increase immediately downstream, and a subsequent decrease further down the flatter chute, approaching a practically constant value. Considerable larger air entrainment was observed shortly downstream of the slope change cross-section, in comparison with that found upstream, in the quasi-uniform flow

    Plant species in Oak (Quercus brantii Lindl.) understory and their relationship with physical and chemical properties of soil in different altitude classes in the Arghvan valley protected area, Iran

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    The present survey was carried out in Oak (Quercus brantii Lindl.) woodlands of Arghvan valley protected area, in Ilam province, western Iran. The main aim of this study was to survey the understory vegetation of oak in different classes of altitude (1400-1600, 1600-1800 and >1800 m) in the southern aspects, and their relationship with physical and chemical properties of soil. Four transects, with an interval of 200 m were selected from the lowest to the highest points of hillside. 25 individual oak trees were selected on and out of the transects as a plot center. The plot area was obtained using Whittaker’s nested plots and species / area curve. In order to find the relationship between soil properties and vegetation, and also to determine the most effective factors on the distribution of vegetation, multivariate procedures, i.e., Principal Component Analysis (PCA) and Canonical Correspondence Analysis (CCA) were used. Based on these analyses three groups were obtained. These groups exactly coordinated with our sample plots in altitudinal classes and had different soil and vegetation characteristics. The most important factors in the lowland group were pH, SP, OC, N,P and K, and those in the highland group were altitude, BD and stone percentage. The midland group was intermediate to these two groups, although its conditions were more similar to the highland group. The results also indicated a decrease in Shannon-Weiner and Margalef’s indices from lowland toward the highland

    Expression profiling of plac1 in murine cancer cell lines

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    Aim: Placenta-specific 1 (PLAC1) is among recently-discovered placental antigens which exerts fundamental role in placental function and development. Increasing body of literature shows that PLAC1 is frequently activated and expressed in a wide variety of human cancers and promote cancer progression. However, no data is available regarding the expression of mouse orthologue, plac1, in murine cancer cell lines. Materials and Methods: We investigated the expression of plac1 in a series of murine cell lines from different histological origins, mammary carcinoma (4T1), melanoma (B16F10), colorectal carcinoma (CT26), renal carcinoma (Renca), glioma (GL26), B-cell lymphoma (A20 and BCL1) and also two fibroblast cell lines (NIH3T3 and L929), using RT-PCR, Western blotting and flow cytometry. Results: Our data demonstrated that plac1 transcript and plac1 protein were expressed in all examined cell lines, as judged by RT-PCR and Western blot, respectively. The molecular weight of mouse plac1 was experimentally observed to be approximately 24 kD. Flow cytometric analysis showed surface expression of plac1 in aforesaid cell lines ranging from 2 to 42.5. Conclusion: Based on the ubiquitous expression of plac1, the investigated cancer cell lines or immortalized cell lines can be used to examine the role of plac1 in the process of immortalization. Copyright © Experimental Oncology 2019

    A preliminary study of NER and MMR pathways involved in chemotherapy response in bladder transitional cell carcinoma: Impact on progression-free survival

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    One of the main genotoxic drugs used in bladder cancer chemotherapy is cisplatin. While it is applied in most types of cancers, resistance to cisplatin is wildly common. In order to overcome drug resistance, it is necessary to determine a predictive marker. This study was conducted to provide basic data for selecting and designing a gene profile for further cohort and RCT studies in the future to improve response to treatment in bladder cancer. The expression levels of ERCC1, MLH1, MSH2, and CTR1 mRNA were determined in the tumor tissue using real-time q-PCR. Progression-free survival (PFS) was analyzed in term of the level of genes expression. The results revealed that the level of ERCC1 mRNA expression was higher in the recurrence (R) group compared to the no recurrence (NR) group. Moreover, the PFS time was increased in the patients with an ERCC1 expression level of below 1.57. The level of MLH1 and MSH2 mRNA expression was lower in the R group compared to the NR group; therefore, PFS time was increased in the patients with MLH1 and MSH2 gene expression levels above the cutoff point. While the level of CTR1 mRNA expression was higher in the R group versus the NR group, the PFS time was longer in the patients with CTR1 expression levels of below 1.265 compared to the patients with high levels of CTR1 expression. It can be concluded that the level of ERCC1, MLH1, MSH2, and CTR1 mRNA expression may be associated with PFS time as possible therapeutic targets for decreasing cisplatin resistance. © 2020, Iranian Journal of Pharmaceutical Research. All rights reserved
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