122 research outputs found

    Micropropagation of White Palash tree (Butea monosperma (Lam.) Taub. Var. lutea (Witt.)).

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    An efficient and reproducible protocol is established for rapid in vitro multiplication of an endangered, valuable medicinal plant, Butea monosperma (Lam.) Taub. Var. lutea, through cotyledonary nodes of mature seeds. Among various cytokinins tested, high frequency of direct shoot regeneration was induced on Murashige and skoog (MS) medium supplemented with BAP, which found to be more effective and showed optimal response at 2 mg/L with a maximum number of 8.35±0.32 multiple shoots per explant. Proliferation of shoots was established by repeated subculturing on to same regeneration medium with 2-3 weeks of time interval. Rooting of regenerated shoots was achieved after 3 weeks of culture on MS medium containing 1 mg/L IBA. In vitro raised plantlets were transferred to pots containing sterilized soil and vermiculate mixture in 1:1 ratio and then shifted to greenhouse. Well established plantlets exhibited 75% survival rate

    Pathogenicity of Nomuraea rileyi (Farlow) Samson against castor semilooper, Paralellia algira Linnaeus

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    ABSTRACT The larvae of Paralellia algira L. (II, III and IV instars) were treated with subculture I, II and insect cultures of Nomuraea rileyi to evaluate the pathogenicity. Results showed larval mortalities at all the concentrations of the three cultures. First subculture and insect culture were almost equally efficacious in causing the disease. Slightly lowered mortalities were recorded with subculture II. Reduction in larval mortalities was noticed with advancement of the age in P. algira larvae. Almost 100 per cent mortality of II instar larvae was observed with 1x10 8 spores ml -1 concentration whereas it was reduced by 5 -10 per cent against III and IV instars

    Impact of calcium on salivary α-amylase activity, starch paste apparent viscosity and thickness perception

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    Thickness perception of starch-thickened products during eating has been linked to starch viscosity and salivary amylase activity. Calcium is an essential cofactor for α-amylase and there is anecdotal evidence that adding extra calcium affects amylase activity in processes like mashing of beer. The aims of this paper were to (1) investigate the role of salivary calcium on α-amylase activity and (2) to measure the effect of calcium concentration on apparent viscosity and thickness perception when interacting with salivary α-amylase in starch-based samples. α-Amylase activity in saliva samples from 28 people was assessed using a typical starch pasting cycle (up to 95 °C). The activity of the enzyme (as measured by the change in starch apparent viscosity) was maintained by the presence of calcium, probably by protecting the enzyme from heat denaturation. Enhancement of α-amylase activity by calcium at 37 °C was also observed although to a smaller extent. Sensory analysis showed a general trend of decreased thickness perception in the presence of calcium, but the result was only significant for one pair of samples, suggesting a limited impact of calcium enhanced enzyme activity on perceived thickness

    Studying vapor-liquid transition using a generalized ensemble

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    Homogeneous vapor-liquid nucleation is studied using the generalized Replica Exchange Method (gREM). The generalized ensemble allows the study of unstable states that cannot directly be studied in the canonical ensemble. Along with replica exchange, this allows for efficient sampling of the multiple states in a single simulation. Statistical Temperature Weighted Histogram Analysis Method is used for postprocessing to get a continuous free energy curve from bulk vapor to bulk liquid. gREM allows the study of planar, cylindrical, and spherical interfaces in a single simulation. The excess Gibbs free energy for the formation of a spherical liquid droplet in vapor for a Lennard-Jones system is calculated from the free energy curve and compared against the umbrella sampling results. The nucleation free energy barrier obtained from gREM is then used to calculate the nucleation rate without relying on any classification scheme for separating the vapor and liquid

    The Level of Isoprostanes as a Non-invasive Marker for in vivo Lipid Peroxidation in Secondary Progressive Multiple Sclerosis

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    Oxidative stress leads to lipid peroxidation and may contribute to the pathogenesis of lesions in multiple sclerosis (MS), an autoimmune disease characterized by inflammatory as well as degenerative phenomena. Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are a new class of sensitive specific markers for in vivo lipid peroxidation. In this study 26 patients (15 females and 11 males; mean age 48.2 ± 15.2 year; mean disease duration 10.0 ± 6.5 year) with secondary progressive MS (SPMS) and 12 healthy controls were enrolled. In patients with multiple sclerosis the lipid peroxidation as the level of urine isoprostanes and the level of thiobarbituric acid reactive species (TBARS) in plasma were estimated. Moreover, we estimated the total antioxidative status (TAS) in plasma. It was found that the urine isoprostanes level was over 6-fold elevated in patients with SPMS than in control (P < 0.001). In SPMS patients TBARS level was also statistically higher than in controls (P < 0.01). However, we did not observed any difference of TAS level in serum between SPMS patients and controls (P > 0.05). In patients with SPMS the lipid peroxidation and oxidative stress measured as the increased level of isoprostanes was observed. Thus, we suggest that the level of isoprostanes may be used as non-invasive marker for a determination of oxidative stress what in turn, together with clinical symptoms, may determine an specific antioxidative therapy in SPMS patients

    Detrimental effects of tropisetron on permanent ischemic stroke in the rat

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    <p>Abstract</p> <p>Background</p> <p>Recent <it>in vitro </it>evidence indicates that blockade of 5-hydroxytryptamine (5-HT) receptor 3 (5-HT<sub>3</sub>) is able to confer protection in different models of neuronal injury. The purpose of the present study was to investigate the effect of tropisetron, a 5-HT<sub>3 </sub>receptor antagonist, on infarct size and neurological score in a model of ischemic stroke induced by permanent middle cerebral artery occlusion (pMCAO) in the rat.</p> <p>Methods</p> <p>Two different doses of tropisetron (5 and 10 mg/kg) or vehicle were administered intraperitoneally 30 min before pMCAO. Neurological deficit scores, mortality rate and infarct volume were determined 24 h after permanent focal cerebral ischemia.</p> <p>Results</p> <p>Tropisetron failed to reduce cerebral infarction. Animals receiving tropisetron showed a significant increase (p < 0.05) in neurological deficits and mortality rate.</p> <p>Conclusion</p> <p>Data from this study indicate that blockade of 5-HT<sub>3 </sub>receptors with tropisetron worsens ischemic brain injury induced by pMCAO. These findings could have important clinical implications. Patients taking tropisetron, and possibly other 5-HT<sub>3 </sub>antagonists, could potentially have a worse outcome following a brain infarct.</p

    The Maltase Involved in Starch Metabolism in Barley Endosperm Is Encoded by a Single Gene

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    During germination and early seedling growth of barley (Hordeum vulgare), maltase is responsible for the conversion of maltose produced by starch degradation in the endosperm to glucose for seedling growth. Despite the potential relevance of this enzyme for malting and the production of alcoholic beverages, neither the nature nor the role of maltase is fully understood. Although only one gene encoding maltase has been identified with certainty, there is evidence for the existence of other genes and for multiple forms of the enzyme. It has been proposed that maltase may be involved directly in starch granule degradation as well as in maltose hydrolysis. The aim of our work was to discover the nature of maltase in barley endosperm. We used ion exchange chromatography to fractionate maltase activity from endosperm of young seedlings, and we partially purified activity for protein identification. We compared maltase activity in wild-type barley and transgenic lines with reduced expression of the previously-characterised maltase gene Agl97, and we used genomic and transcriptomic information to search for further maltase genes. We show that all of the maltase activity in the barley endosperm can be accounted for by a single gene, Agl97. Multiple forms of the enzyme most likely arise from proteolysis and other post-translational modifications

    Identification of uPAR-positive Chemoresistant Cells in Small Cell Lung Cancer

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    BACKGROUND: The urokinase plasminogen activator (uPA) and its receptor (uPAR/CD87) are major regulators of extracellular matrix degradation and are involved in cell migration and invasion under physiological and pathological conditions. The uPA/uPAR system has been of great interest in cancer research because it is involved in the development of most invasive cancer phenotypes and is a strong predictor of poor patient survival. However, little is known about the role of uPA/uPAR in small cell lung cancer (SCLC), the most aggressive type of lung cancer. We therefore determined whether uPA and uPAR are involved in generation of drug resistant SCLC cell phenotype. METHODS AND FINDINGS: We screened six human SCLC cell lines for surface markers for putative stem and cancer cells. We used fluorescence-activated cell sorting (FACS), fluorescence microscopy and clonogenic assays to demonstrate uPAR expression in a subpopulation of cells derived from primary and metastatic SCLC cell lines. Cytotoxic assays were used to determine the sensitivity of uPAR-positive and uPAR-negative cells to chemotherapeutic agents. The uPAR-positive cells in all SCLC lines demonstrated multi-drug resistance, high clonogenic activity and co-expression of CD44 and MDR1, putative cancer stem cell markers. CONCLUSIONS: These data suggest that uPAR-positive cells may define a functionally important population of cancer cells in SCLC, which are resistant to traditional chemotherapies, and could serve as critical targets for more effective therapeutic interventions in SCLC

    Intermittent Hypoxia-Induced Cognitive Deficits Are Mediated by NADPH Oxidase Activity in a Murine Model of Sleep Apnea

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    Background: In rodents, exposure to intermittent hypoxia (IH), a hallmark of obstructive sleep apnea (OSA), is associated with neurobehavioral impairments, increased apoptosis in the hippocampus and cortex, as well as increased oxidant stress and inflammation. Excessive NADPH oxidase activity may play a role in IH-induced CNS dysfunction. Methods and Findings: The effect of IH during light period on two forms of spatial learning in the water maze and well as markers of oxidative stress was assessed in mice lacking NADPH oxidase activity (gp91phox _/Y) and wild-type littermates. On a standard place training task, gp91phox _/Y displayed normal learning, and were protected from the spatial learning deficits observed in wild-type littermates exposed to IH. Moreover, anxiety levels were increased in wild-type mice exposed to IH as compared to room air (RA) controls, while no changes emerged in gp91phox _/Y mice. Additionally, wild-type mice, but not gp91phox _/Y mice had significantly elevated levels of NADPH oxidase expression and activity, as well as MDA and 8-OHDG in cortical and hippocampal lysates following IH exposures. Conclusions: The oxidative stress responses and neurobehavioral impairments induced by IH during sleep are mediated, at least in part, by excessive NADPH oxidase activity, and thus pharmacological agents targeting NADPH oxidase may provid
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