110 research outputs found
Effect of salt stress on expression of carotenoid pathway genes in tomato
Carotenoids, the naturally occurring isoprenoids form essential components of photosynthetic antenna and reaction centre complexes. Thus they play a significant role in absorption, dissipation and transfer of light energy for the process of photosynthesis. The effects of salt stress on carotenoid gene expression in tomato leaves were studied. For that tomato plants were subjected to different concentration of salt water. Morphological characters such as plant height, no. of fruits per plant, chlorophyll content and expression of four major carotenoid pathway genes such as phytoene synthase, phytoene desaturase, zeta carotene desaturase and lycopene beta cyclase were analysed. The quantitative expression analysis using real time PCR has shown a decrease in the expression of all the studied genes as the salt concentration increased. Among the different concentrations of NaCl used for the experiment, it was seen that 200 mM was most detrimental for the carotenoid gene expression. Lycopene beta cyclase, the enzyme that converts lycopene to beta carotene was seen to be highly affected compared to other genes studied showing a 1.87 fold inhibition in its expression at 200 mM NaCl
Cooperative Hyper-Scheduling based improving Energy Aware Life Time Maximization in Wireless Body Sensor Network Using Topology Driven Clustering Approach
The Wireless Body Sensor Network (WBSN) is an incredible developing data transmission network for modern day communication especially in Biosensor device networks. Due to energy consumption in biomedical data transfer have impacts of sink nodes get loss information on each duty cycle because of Traffic interruptions. The reason behind the popularity of WBSN characteristics contains number of sensor nodes to transmit data in various dense regions. Due to increasing more traffic, delay, bandwidth consumption, the energy losses be occurred to reduce the lifetime of the WBSN transmission. So, the sensor nodes are having limited energy or power, by listening to the incoming signals, it loses certain amount of energy to make data losses because of improper route selection. To improve the energy aware lifetime maximization through Traffic Aware Routing (TAR) based on scheduling. Because the performance of scheduling is greatly depending on the energy of nodes and lifetime of the network. To resolve this problem, we propose a Cooperative Hyper-scheduling (CHS) based improving energy aware life time maximization (EALTM) in Wireless Body sensor network using Topology Driven Clustering Approach (TDCA).Initially the method maintains the traces of transmission performed by different Bio-sensor nodes in different duty cycle. The method considers the energy of different nodes and history of earlier transmission from the Route Table (RT) whether the transmission behind the Sink node. Based on the RT information route discovery was performed using Traffic Aware Neighbors Discovery (TAND) to estimate Data Transmission Support Measure (DTSM) on each Bio-sensor node which its covers sink node. These nodes are grouped into topology driven clustering approach for route optimization. Then the priority is allocated based on The Max-Min DTSM, the Cooperative Hyper-scheduling was implemented to schedule the transmission with support of DTSM to reduce the energy losses in WBSN. This improves the energy level to maximization the life time of data transmission in WBSN than other methods to produce best performance in throughput energy level
Discovery of a new Steinernema sp. (Rhabditida: Steinernematidae) with higher shelf life and better efficacy against red palm weevil under laboratory conditions
Entomopathogenic nematodes (EPN) are excellent bio-control agents for the management of insect pests of soil and cryptic habitat. One of the greatest challenges in the successful utilization of EPN is the poor shelf life of infective juveniles (IJs) under ambient temperature. The present study aimed to evaluate the survival and virulence of different EPN species for determining a superior one in the bio-suppression of red palm weevil (RPW). Among the five species of Steinernematids and two Heterorhabditid isolates evaluated, Steinernema sp. (S0804) sustained up to 13 months, with a desirable survival of 100 per cent during the first five months to about 64 per cent ten months after storage at ambient temperature. Virulence of Steinernema sp. (S0804) sustained up to ten months of storage, was confirmed using Galleria mellonella inoculation test. However, the viable IJs were observed only up to one month in both the Heterorhabditids and up to a period of four to six months of storage in all other Steinernematids. The Steinernema sp. (S0804) was also found to be efficacious against the grubs of RPW in filter paper bio-assay inducing 100 per cent larval mortality in 72 h when applied @ 200 IJs per grub and confirmed further by leaf petiole bioassay. The study thus revealed higher survival and virulence of Steinernema sp. (S0804) and also found to be a potential bio-control agent against RPW. To the best of our knowledge, this is the first EPN isolate reported, which could survive for more than one year at ambient temperature without any additives
IMPLEMENTATION AND STUDY ON INNOVATIVE NEW TEACHING METHODS TO ENHANCE LEARNING OF MECHANICAL PRINCIPLES MODULE AT UNDERGRADUATE LEVEL
This paper is an outcome of the motivation and need to address wide spectrum of teaching and learning styles that are recognized by the students. It is the order of the day that the student’s are encouraged in self-learning, engaged learning, peer to peer learning etc., forproviding better exposure and ambience for easy understanding of the basic concepts. In this context, Mechanical Principles module that is taught at undergraduate level at the Department of Mechanical engineering at Caledonian College of Engineering, Oman is considered for implementing new teaching tools. This is a core module in mechanical engineering where the teaching involves a large group of students which require addressing pedagogical teaching and resource challenges. Various strategies are developed in order to enhance the teaching and learning experience of students such as change in layout of their seating arrangements inside the class room, use of soft tools for wider learning, open ended lab to improve the practical skills, use of CCE learn for online access of course documents, online quizzes for more interactive learning as well as access for students to video lectures &EBrary sources in addition to the traditional teaching. Survey conducted towards the level of satisfaction of students indicates that a majority of students appreciate different teaching and learning methods other than the traditional ones. The present work that is carried out for Mechanical principles module can be extended to other related modules. Definitely any useful teaching learning tools used in addition to the conventional methods of teaching creates attention to student community and enhances their theoretical and practical exposure
Pregnancy associated plasma protein-A (PAPP-A) as an early marker for the diagnosis of acute coronary syndrome.
Aims and objectives
Pregnancy associated plasma protein-A (PAPP-A), a metalloproteinase plays a pivotal role in the pathogenesis of atherosclerosis. Recent studies have reported that elevated levels of PAPP-A, signal the onset of acute coronary syndrome (ACS). We, therefore, proposed to study the analytical competence of PAPP-A in patients admitted to the emergency department with chest pain and finally diagnosed as ACS.
Methods and results
Pregnancy associated plasma protein-A was measured using enzyme-linked immunosorbent assay (ELISA) in 485 patients admitted to emergency care unit, of which 89 patients were diagnosed as Non-cardiac chest pain (NCCP). Elevated levels of PAPP-A were observed in patients diagnosed as ACS on comparison with the controls. Receiver operator characteristic (ROC) curve analysis showed PAPP-A to be a good discriminator between ischaemic and non-ischaemic patients. The area under the curve was found to be 0.904, 95% CI (0.874–0.929) with 90% sensitivity and 85% specificity (P< 0.0001). The cut-off value from the ROC curve was 0.55 μg/mL above which PAPP-A was considered to be positive.
Conclusion
Pregnancy associated plasma protein-A seems to be a promising biomarker for identification and risk stratification for patients with ACS
Apigenin inhibits PMA-induced expression of pro-inflammatory cytokines and AP-1 factors in A549 cells
Acute and chronic alveolar or bronchial inflammation is thought to be central to the pathogenesis of many respiratory disorders. Cytokines and granulocyte macrophage colony-stimulating factors (GM-CSF) play an important role in chronic inflammation. Activator protein-1 (AP-1) the superfamily of transcription factors is involved in proliferation, differentiation, apoptosis, and transformation including inflammation. Understanding the function and regulation of proinflammatory factors involved in inflammation may provide the novel therapeutic strategies in the treatment of inflammatory diseases. Our aim of the present study is to investigate the pro-inflammatory cytokines and pattern of AP-1 factors expressed during activation of lung adenocarcinoma A549 cells by Phorbol-12-myristate-13-acetate (PMA) and to understand the anti-inflammatory effect of apigenin. A549 cells were treated with and without PMA or apigenin, and the cell viability was assessed by MTT assay. Expressions of inflammatory mediators and different AP-1 factors were analyzed by semi-quantitative RT-PCR. IL-6 protein secreted was analyzed by ELISA, and expressions of IL-1β, c-Jun, and c-Fos proteins were analyzed by Western blotting. Activation of A549 cells by PMA, induced the expression of pro-inflammatory cytokine (IL-1β, IL-2, IL-6, IL-8, and TNF-α) mRNAs and secretion of IL-6 and the expression of specific AP-1 factors (c-Jun, c-Fos, and Fra-1). Treatment of cells with apigenin, significantly inhibited PMA-stimulated mRNA expression of above pro-inflammatory cytokines, AP-1 factors, cyclooxygenase-2, and secretion of IL-6 protein. Results suggested that the AP-1 factors may be involved in inflammation and apigenin has anti-inflammatory effect, which may be useful for therapeutic management of lung inflammatory diseases. © 2015, Springer Science+Business Media New York
Interplay of nuclear receptors (ER, PR, and GR) and their steroid hormones in MCF-7 cells
Steroid hormones and their nuclear receptors play a major role in the development and progression of breast cancer. MCF-7 cells are triple-positive breast cancer cells expressing estrogen receptor (ER), progesterone receptor (PR), and glucocorticoid receptor (GR). However, interaction and their role in expression pattern of activator protein (AP-1) transcription factors (TFs) are not completely understood. Hence, in our study, MCF-7 cells were used as an in vitro model system to study the interplay between the receptors and hormones. MCF-7 cells were treated with estradiol-17β (E2), progesterone (P4), and dexamethasone (Dex), alone or in combination, to study the proliferation of cells and expression of AP-1 genes. MTT assay results show that E2 or P4 induced the cell proliferation by more than 35 %, and Dex decreased the proliferation by 26 %. E2 and P4 are found to increase ERα by more than twofold and c-Jun, c-Fos, and Fra-1 AP-1 TFs by more than 1.7-fold, while Dex shows opposite effect of E2- or P4-induced effect as well as effect on the expression of nuclear receptors and AP-1 factors. E2 antagonist Fulvestrant (ICI 182,780) found to reduce proliferation and E2-induced expression of AP1-TFs, while P4 or Dex antagonist Mifepristone (RU486) is found to block GR-mediated expression of NRs and AP-1 mRNAs. Results suggest that E2 and P4 act synergistically, and Dex acts as an antagonist of E2 and P4
Aqueous areca nut extract induces oxidative stress in human lung epithelial A549 cells: Probable role of p21 in inducing cell death
Areca nut a well-known masticator used across globe. Habitual chewing of areca nut is associated with serious oral health effects. However, the role of areca nut in oxidative stress induction and cell death is less understood. Hence, in the present study we aimed to evaluate the toxic mechanism of areca nut extract on human lung epithelial A549 cells. Cells were treated with or without aqueous areca nut extract and cell viability was measured by MTT assay. Cells treated with areca nut extract show reduced viability in a dose dependent manner with the IC50 of 0.5 concentration. Areca nut extract induced the reactive oxygen species (ROS), lipid peroxidation followed by membrane damage with leakage of lactate dehydrogenase (LDH) enzyme. Cells with continuous exposure of areca nut extract depletes the free radical neutralizing anti-oxidant enzymes like superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px) and Glutathione-S-transferase (GST). Further, the analysis of mRNA expression of apoptotic genes and cell cycle regulators show decreased expression of anti-apoptotic gene (Bcl-2), Cyclin E1, Cyclin D1, CDK4, Rb and p53 whereas induced expression of p21 and marginal increase of pro-apoptotic gene (Bax) confirms the toxic nature of areca nut. Thus, cell death due to areca nut exposure may be through different mechanism rather than the conventional apoptotic pathway, where p21 induction might be independent of p53 action, which possibly suggests that there may be a role of p21 in oxidative stress induced cell death. Further FACS analysis confirms cell death in areca nut treated cells. © 2016 Elsevier Inc
Cadmium induces oxidative stress and apoptosis in lung epithelial cells
Cadmium (Cd) is one of the well-known highly toxic environmental and industrial pollutants. Cd first accumulates in the nucleus and later interacts with zinc finger proteins of antiapoptotic genes and inhibit the binding of transcriptional factors and transcription. However, the role of Cd in oxidative stress and apoptosis is less understood. Hence, the present study was undertaken to unveil the mechanism of action. A549 cells were treated with or without Cd and cell viability was measured by MTT assay. Treatment of cells with Cd shows reduced viability in a dose-dependent manner with IC50 of 45 μM concentration. Cd significantly induces the reactive oxygen species (ROS), lipid peroxidation followed by membrane damage with the leakage of lactate dehydrogenase (LDH). Cells with continuous exposure of Cd deplete the antioxidant super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzymes. Further, analysis of the expression of genes involved in apoptosis show that both the extrinsic and intrinsic apoptotic pathways were involved. Death receptor marker tumor necrosis factor-α (TNF-α), executor caspase-8 and pro-apoptotic gene (Bax) were induced, while antiapoptotic gene (Bcl-2) was decreased in Cd-treated cells. Fluorescence-activated cell sorting (FACS) analysis further confirms the induction of apoptosis in Cd-treated A549 cells
Differential expression of AP-1 transcription factors in human prostate LNCaP and PC-3 cells: role of Fra-1 in transition to CRPC status
Androgen receptor (AR) signaling axis plays a vital role in the development of prostate and critical in the progression of prostate cancer. Androgen withdrawal initially regresses tumors but eventually develops into aggressive castration-resistant prostate cancer (CRPC). Activator Protein-1 (AP-1) transcription factors are most likely to be associated with malignant transformation in prostate cancer. Hence, to determine the implication of AR and AP-1 in promoting the transition of prostate cancer to the androgen-independent state, we used AR-positive LNCaP and AR-negative PC-3 cells as an in vitro model system. The effect of dihydrotestosterone or anti-androgen bicalutamide on the cell proliferation and viability was assessed by MTT assay. Expression studies on AR, marker genes-PSA, TMPRSS2, and different AP-1 factors were analyzed by semi-quantitative RT-PCR and expressions of AR and Fra-1 proteins were analyzed by Western blotting. Dihydrotestosterone induced the cell proliferation in LNCaP with no effect on PC-3 cells. Bicalutamide decreased the viability of both LNCaP and PC-3 cells. Dihydrotestosterone induced the expression of AR, PSA, c-Jun, and Fra-1 in LNCaP cells, and it was c-Jun and c-Fos in case of PC-3 cells, while bicalutamide decreased their expression. In addition, constitutive activation and non-regulation of Fra-1 by bicalutamide in PC-3 cells suggested that Fra-1, probably a key component, involved in transition of aggressive androgen-independent PC-3 cells with poor prognosis. © 2017, Springer Science+Business Media New York
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