711 research outputs found

    Competition of Bacillus thuringiensis Cry1 Toxins for Midgut Binding Sites: A Basis for the Development and Management of Transgenic Tropical Maize Resistant to Several Stemborers

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    Binding and competition of five Bacillus thuringiensis toxins—Cry1Ab, Cry1Ac, Cry1Ba, Cry1Ca, and Cry1Ea—for midgut binding sites from three pests, Spodoptera frugiperda, Diatraea saccharalis, and Diatraea grandiosella, were investigated as part of a strategy to develop tropical transgenic maize resistant to several stemborers. On S. frugiperda, Cry1Ab and Cry1Ac compete for the same binding site; Cry1Ba and Cry1Ca compete for a second binding site. Cry1Ea recognizes a third specific binding site in S. frugiperda and does not compete with any of the other toxins. On D. grandiosella and D. saccharalis, Cry1Ac competes with Cry1Ab and not with Cry1Ba and Cry1Ca. Cry1Ba and Cry1Ca recognize each a specific binding site and do not compete with any of the other four toxins. Cry1Ea does not recognize any binding site on Diatraea species. Combinations of toxins are proposed to develop transgenic maize resistant to the three stemborers while allowing resistance management

    Sinteza i anthelmintičko djelovanje novih 2-supstituiranih-4,5-difenil imidazola

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    A series of 2-substituted-4,5-diphenyl imidazoles 1a-j were synthesized by refluxing benzil with different substituted aldehydes in the presence of ammonium acetate and glacial acetic acid. Structures of the synthesized compounds were confirmed on the basis of IR, 1H NMR and mass spectral data. Compounds 1a-j were screened for anthelmintic activity. Test results revealed that compounds showed paralysis time of 0.24 to 1.54 s and death time of 0.39 to 4.40 s while the standard drugs albendazole and piperazine citrate showed paralysis time of 0.54 and 0.58 s and death time of 2.16 and 2.47 s, respectively, at the same concentration of 1 % (m/V). Five compounds, 2-[2-hydroxyphenyl]-4,5-diphenyl imidazole (1b), 2-[3-methoxyphenyl]-4,5-diphenyl imidazole (1c), 2-[2-phenylethenyl]-4,5-diphenyl imidazole (1e), 2-[4-fluorophenyl]-4,5-diphenyl imidazole (1g) and 2-[3-nitrophenyl]-4,5-diphenyl imidazole (1h) showed significant anthelmintic activity compared to the standard drugs.Refluksiranjem benzila s različitim supstituiranim aldehidima u prisutnosti amonijeva acetata i ledene octene kiseline sintetizirana je serija 2-supstituiranih-4,5-difenil imidazola (1a-j). Strukture sintetiziranih spojeva potvrđene su IR, 1H NMR i masenom spektroskopijom. U testovima na anthelmintičko djelovanje određeno je vrijeme paralize 0,24 do 1,54 min i vrijeme smrti 0,39 do 4,40 min, dok standarni lijekovi albendazol i piperazin citrat imaju vrijeme paralize 0,54 i 0,58 min, a vrijeme smrti 2,16, odnosno 2,47 min pri istim koncentracijama (1 % m/V). Pet spojeva, 2-[2-hidroksifenil]-4,5-difenil imidazol (1b), 2-[3-metoksifenil]-4,5-difenil imidazol (1c), 2-[2-feniletenil]-4,5-difenil imidazol (1e), 2-[4-fluorofenil]-4,5-difenil imidazol (1g) i 2-[3-nitrofenil]-4,5-difenil imidazol (1h) pokazuju značajno anthelmintičko djelovanje u odnosnu na standardne lijekove

    Set Theory and its Place in the Foundations of Mathematics:a new look at an old question

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    This paper reviews the claims of several main-stream candidates to be the foundations of mathematics, including set theory. The review concludes that at this level of mathematical knowledge it would be very unreasonable to settle with any one of these foundations and that the only reasonable choice is a pluralist one

    Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in <i>C. elegans</i>

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    Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling

    Vascular responses of the extremities to transdermal application of vasoactive agents in Caucasian and African descent individuals

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    This is an accepted manuscript of an article published by Springer in European Journal of Applied Physiology on 04/04/2015, available online: https://doi.org/10.1007/s00421-015-3164-2 The accepted version of the publication may differ from the final published version.© 2015, Springer-Verlag Berlin Heidelberg. Purpose: Individuals of African descent (AFD) are more susceptible to non-freezing cold injury than Caucasians (CAU) which may be due, in part, to differences in the control of skin blood flow. We investigated the skin blood flow responses to transdermal application of vasoactive agents. Methods: Twenty-four young males (12 CAU and 12 AFD) undertook three tests in which iontophoresis was used to apply acetylcholine (ACh 1 w/v %), sodium nitroprusside (SNP 0.01 w/v %) and noradrenaline (NA 0.5 mM) to the skin. The skin sites tested were: volar forearm, non-glabrous finger and toe, and glabrous finger (pad) and toe (pad). Results: In response to SNP on the forearm, AFD had less vasodilatation for a given current application than CAU (P = 0.027–0.004). ACh evoked less vasodilatation in AFD for a given application current in the non-glabrous finger and toe compared with CAU (P = 0.043–0.014) with a lower maximum vasodilatation in the non-glabrous finger (median [interquartile], AFD n = 11, 41[234] %, CAU n = 12, 351[451] %, P = 0.011) and non-glabrous toe (median [interquartile], AFD n = 9, 116[318] %, CAU n = 12, 484[720] %, P = 0.018). ACh and SNP did not elicit vasodilatation in the glabrous skin sites of either group. There were no ethnic differences in response to NA. Conclusion: AFD have an attenuated endothelium-dependent vasodilatation in non-glabrous sites of the fingers and toes compared with CAU. This may contribute to lower skin temperature following cold exposure and the increased risk of cold injuries experienced by AFD.Published versio

    What is the crisis of Western sciences?

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    © 2016, Springer Science+Business Media Dordrecht. This article is an attempt to formulate a clear definition of the concept of crisis of Western sciences introduced by Husserl in his last work. The attempt will be based on a reading of the Krisis, which will stress its underlying continuity with Husserl’s life-long concerns about the theoretical insufficiency of positive sciences, and downplay the novelty of the idea of crisis itself within Husserl’s work. After insisting on the fact that, according to Husserl, only an account of the shortcomings of the scientificity of Western sciences can justify the claim that they are undergoing a crisis, it will be argued that the common definition of the crisis of the sciences as the loss of their significance for life rests on a misunderstanding. The crisis of Western sciences will be characterized, instead, as the repercussion of the crisis of the scientificity of philosophy (and, specifically, of metaphysics) on the scientificity of positive sciences. The loss of significance of scientific knowledge for our existence will in turn appear as a further, inevitable consequence of the uprooting of the sciences from the soil of a universal philosophy culminating in metaphysics, and thus, as a phenomenon deeply intertwined with the crisis of Western sciences, but not identical to it

    Hydroxychloroquine in rheumatic autoimmune disorders and beyond

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    Initially used as antimalarial drugs, hydroxychloroquine (HCQ) and, to a lesser extent, chloroquine (CQ) are currently being used to treat several diseases. Due to its cost-effectiveness, safety and efficacy, HCQ is especially used in rheumatic autoimmune disorders (RADs), such as systemic lupus erythematosus, primary Sjögren's syndrome and rheumatoid arthritis. Despite this widespread use in the clinic, HCQ molecular modes of action are still not completely understood. By influencing several cellular pathways through different mechanisms, CQ and HCQ inhibit multiple endolysosomal functions, including autophagy, as well as endosomal Toll-like receptor activation and calcium signalling. These effects alter several aspects of the immune system with the synergistic consequence of reducing pro-inflammatory cytokine production and release, one of the most marked symptoms of RADs. Here, we review the current knowledge on the molecular modes of action of these drugs and the circumstances under which they trigger side effects. This is of particular importance as the therapeutic use of HCQ is expanding beyond the treatment of malaria and RADs

    Characterization of MgtC, a Virulence Factor of Salmonella enterica Serovar Typhi

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    The MgtC is a virulence factor in Salmonella Typhimurium that is required for growth at low-Mg2+ concentrations and intramacrophage survival. This gene is codified in a conserved region of the Salmonella pathogenicity island 3 (SPI-3), and is also present in the chromosome of other Salmonella serovars. In this study we characterized the MgtC factor in S. Typhi, a human specific pathogen, by using mgtC and SPI-3 mutant strains. We found that MgtC is the most important factor codified in the SPI-3 of S. Typhi for growth in low-Mg2+ media and survival within human cells. In addition, by using reporter genes we determined that the low-Mg2+ concentration, acidic media and PhoP regulator induce mgtC expression in S. Typhi. We suggest that MgtC is the most important virulence factor codified in the SPI-3 of S. Typhi

    Differential CARM1 expression in prostate and colorectal cancers

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    <p>Abstract</p> <p>Background</p> <p>Coactivator-associated arginine methyltransferase 1 (CARM1) functions as a transcriptional coactivator of androgen receptor (AR)-mediated signaling. Correspondingly, overexpression of CARM1 has been associated with the development of prostate cancer (PCa) and its progression to androgen-independent PCa. In our preliminary study, however, the promoting effects of CARM1, with regard to androgen-stimulated AR target gene expression were minimal. These results suggested that the AR target gene expression associated with CARM1 may result primarily from non-hormone dependent activity. The goal of this study was to confirm the pattern of expression of CARM1 in human tumors and determine the mechanism of action in CARM1 overexpressed tumors.</p> <p>Methods</p> <p>Tissue microarray was used to determine the pattern of expression of CARM1 in human cancers by immunohistochemistry. CARM1 expression was also evaluated in prostate and colorectal surgical specimens and the clinical records of all cases were reviewed. In addition, a reporter transcription assay using the prostate-specific antigen (PSA) promoter was used to identify the signaling pathways involved in non-hormone-mediated signal activation associated with CARM1.</p> <p>Results</p> <p>The tissue microarray showed that CARM1 was particularly overexpressed in the colorectal cancers while CARM1 expression was not prevalent in the prostate and breast cancers. Further studies using surgical specimens demonstrated that CARM1 was highly overexpressed in 75% of colorectal cancers (49 out of 65) but not in the androgen-independent PCa. In addition, CARM1's coactivating effect on the entire PSA promoter was very limited in both androgen-dependent and androgen-independent PCa cells. These results suggest that there are other factors associated with CARM1 expression in PSA regulation. Indeed, CARM1 significantly regulated both p53 and NF-κB target gene transcription.</p> <p>Conclusions</p> <p>The results of this study suggest that, in addition to its role in activation of steroid receptors, CARM1 functions as a transcriptional modulator by altering the activity of many transcriptional factors, especially with regard to androgen independent PCa and colorectal cancers.</p
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