656 research outputs found

    Heat-shock pretreatment inhibits sorbitol-induced apoptosis in K562, U937 and HeLa cells.

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    The aim of this study was to determine whether heat-shock pretreatment exerted a protective effect against sorbitol-induced apoptotic cell death in K562, U937 and HeLa cell lines and whether such protection was associated with a decreased cytochrome c release from mithocondria and a decreased activation of caspase-9 and -3. Following heat-shock pretreatment (42 6 0.3C for 1 hr), these cell lines were exposed to sorbitol for 1 hr. Apoptosis was evaluated by DNA fragmentation, whereas caspase-9,-3 activation, cytochrome c release and heat-shock protein70 (HSP70) were assayed by Western Blot. Sorbitol exposure-induced apoptosis in these different cell lines with a marked activation of caspase-9 and caspase- 3, whereas heat-shock pretreatment before sorbitol exposure, induced expression of HSP70 and inhibited sorbitol-mediated cytochrome c release and subsequent activation of caspase-9 and caspase- 3. Similarly, overexpression of HSP70 in the three cell lines studied prevented caspase-9 cleavage and activation as well as cell death. Furthermore, we showed that the mRNA expression of iNOS decreased during both the heat-shock treatment and heat-shock pretreatment before sorbitol exposure. By contrast, the expression of Cu-Zn superoxide dismutase (SOD) and Mn-SOD proteins increased during heat-shock pretreatment before sorbitol exposure. We conclude that, heat-shock pretreatment protects different cell lines against sorbitol-induced apoptosis through a mechanism that is likely to involve SOD family members

    A surge of late-occurring meiotic double-strand breaks rescues synapsis abnormalities in spermatocytes of mice with hypomorphic expression of SPO11

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    Meiosis is the biological process that, after a cycle of DNA replication, halves the cellular chromosome complement, leading to the formation of haploid gametes. Haploidization is achieved via two successive rounds of chromosome segregation, meiosis I and II. In mammals, during prophase of meiosis I, homologous chromosomes align and synapse through a recombination-mediated mechanism initiated by the introduction of DNA double-strand breaks (DSBs) by the SPO11 protein. In male mice, if SPO11 expression and DSB number are reduced below heterozygosity levels, chromosome synapsis is delayed, chromosome tangles form at pachynema, and defective cells are eliminated by apoptosis at epithelial stage IV at a spermatogenesis-specific endpoint. Whether DSB levels produced in Spo11 +/− spermatocytes represent, or approximate, the threshold level required to guarantee successful homologous chromosome pairing is unknown. Using a mouse model that expresses Spo11 from a bacterial artificial chromosome, within a Spo11 −/− background, we demonstrate that when SPO11 expression is reduced and DSBs at zygonema are decreased (approximately 40 % below wild-type level), meiotic chromosome pairing is normal. Conversely, DMC1 foci number is increased at pachynema, suggesting that under these experimental conditions, DSBs are likely made with delayed kinetics at zygonema. In addition, we provide evidences that when zygotene-like cells receive enough DSBs before chromosome tangles develop, chromosome synapsis can be completed in most cells, preventing their apoptotic elimination

    Cyanidium chilense (Cyanidiophyceae, Rhodophyta) from tuff rocks of the archeological site of Cuma, Italy

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    Phlegrean Fields is a large volcanic area situated southwest of Naples (Italy), including both cave and thermoacidic habitats. These extreme environments host the genus Cyanidium; the species C. chilense represents a common phototrophic micro- organism living in anthropogenic caves. With a view to provide a comprehensive characterization for a correct taxonomic classification, morpho-ultrastructural investigations ofC. chilense from Syb’s cave (Phlegren Fields) was herein car-ried out and compared with the thermoacidophilic C. caldarium. The biofilm was also analyzed to define the roleofC. chilensein the establishment of a bio film within caveenvironments. Despite the peculiar ecological and molecular divergences,C. chilenseandC. caldariumshared all the maindiacritic features, suggesting morphological convergence within the genus; cytological identity was found amongC. chilensestrains geographically distant and adapted to different substrates, such as the porous yellow tuff of Sybil cave and calcyte, magnesite and basaltic rocks from other caves. C. chilense is generally dominant in all biofilms, developing monospecific islets, developing both super ficially or betweenfungal hyphae and coccoid cyanobacteria. Extracellular polymeric substances (EPS) were recorded in C. chilense bio filmsfrom Sybil cave, confirming the role of EPS in facilitating cellsadhesion to the surface, creating a cohesive network of inter-connecting biofilm cell

    Learning to focus on number.

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    With age and education, children become increasingly accurate in processing numerosity. This developmental trend is often interpreted as a progressive refinement of the mental representation of number. Here we provide empirical and theoretical support for an alternative possibility, the filtering hypothesis, which proposes that development primarily affects the ability to focus on the relevant dimension of number and to avoid interference from irrelevant but often co-varying quantitative dimensions. Data from the same numerical comparison task in adults and children of various levels of numeracy, including Mundurucú Indians and western dyscalculics, show that, as predicted by the filtering hypothesis, age and education primarily increase the ability to focus on number and filter out potentially interfering information on the non-numerical dimensions. These findings can be captured by a minimal computational model where learning consists in the training of a multivariate classifier whose discrimination boundaries get progressively aligned to the task-relevant dimension of number. This view of development has important consequences for education

    EV20-mediated delivery of cytotoxic auristatin MMAF exhibits potent therapeutic efficacy in cutaneous melanoma.

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    Abstract Cutaneous melanoma is one of the cancers with the fastest rising incidence and in its advanced metastatic form is a highly lethal disease. Despite the recent approval of several new drugs, the 5-year overall survival rate for advanced cutaneous melanoma is still below 20% and therefore, the development of novel treatments remains a primary need. Antibody-Drug Conjugates are an emerging novel class of anticancer agents, whose preclinical and clinical development has recently seen a remarkable increase in different tumors, including melanoma. Here, we have coupled the anti-HER-3 internalizing antibody EV20 to the cytotoxic drug monomethyl auristatin F (MMAF) to form a novel antibody-drug conjugate (EV20/MMAF). In a panel of human melanoma cell lines, this novel ADC shows a powerful, specific and target-dependent cell killing activity, independently of BRAF status. Efficacy studies demonstrated that a single administration of EV20/MMAF leads to a long-lasting tumor growth inhibition. Remarkably, the effect of this novel ADC was superior to the BRAF inhibitor vemurafenib in preventing kidney, liver and lung melanoma metastases. Overall, these results highlight EV20/MMAF as a novel ADC with promising therapeutic efficacy, warranting extensive pre-clinical evaluation in melanoma with high levels of HER-3 expression

    Granulocyte- and monocyte-platelet adhesion index in coronary and peripheral blood after extracorporeal circulation and reperfusion

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    Background: Neutrophil-granulocyte and mononuclear-cell functional changes occur during cardiopulmonary bypass and cardiovascular surgery. Leukocyte-platelet interaction, leading to generation of heterotypic co-aggregates, represents an amplification mechanism of local inflammatory response and tissue damage. Methods: Samples of 20 patients were drawn from coronary sinus before cardioplegia and after reperfusion, as well as from peripheral blood at 5 and 24 hours postoperatively. Granulocyte and monocyte expression of CD162, CD15s, CD18 and CD11b were quantified by flow cytometry at the different times. Parallel variations of leukocyte-platelet conjugates (percentages) and a derived (cell number-normalized) leukocyte-platelet adhesion index were measured using antibodies against CD45, CD14 and CD41a. The evaluation of platelet functional state was carried out using antibodies against CD62P (P-selectin) and PAC-1. Results: Monocyte and granulocyte cell number increased in coronary blood at reperfusion and in peripheral blood post-operatively. A different course characterized the changes of the leukocyte-platelet adhesion index with respect to the variations of circulating leukocyte-platelet co-aggregates . Leukocyte molecules expression showed no significant variations for CD15s on both leukocyte subsets, while a significant up-modulation for CD162 was observed on monocytes at 24 hours after extracorporeal circulation (P=0.0002), and for CD11b on granulocytes at 5 hours post-operatively (P=0.033). A loss of CD162 expression was observed at reperfusion (P=0.0038) on granulocytes, associated to a down-modulation of CD18 (P=0.0033) and CD11b (P=0.0184) in peripheral blood at 24 hours. No significant up-regulation of platelet activatory molecules was found at reperfusion, as well as post-operatively, when compared with the before-cardioplegia derived data. Conclusions: The variations of a normalized leukocyte-platelet adhesion index seem to reflect the leukocyte-platelet functional interaction more accurately than the measurements of cellular conjugates. The absence of platelet activation suggests that the leukocyte membrane modifications play a main role in controlling the formation and stability of heterotypic leukocyte-platelet co-aggregates after cardiac surgery with extracorporeal circulation

    Crystal structure of the Pseudomonas aeruginosa BEL-1 extended-spectrum β-lactamase and its complexes with moxalactam and imipenem

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    BEL-1 is an acquired class A extended-spectrum β-lactamase (ESBL) found in Pseudomonas aeruginosa clinical isolates from Belgium which is divergent from other ESBLs (maximum identity of 54% with GES-type enzymes). This enzyme is efficiently inhibited by clavulanate, imipenem, and moxalactam. Crystals of BEL-1 were obtained at pH 5.6, and the structure of native BEL-1 was determined from orthorhombic and monoclinic crystal forms at 1.60-Å and 1.48-Å resolution, respectively. By soaking native BEL-1 crystals, complexes with imipenem (monoclinic form, 1.79-Å resolution) and moxalactam (orthorhombic form, 1.85-Å resolution) were also obtained. In the acyl-enzyme complexes, imipenem and moxalactam differ by the position of the α- substituent and of the carbonyl oxygen (in or out of the oxyanion hole). More surprisingly, the Ω-loop, which includes the catalytically relevant residue Glu166, was found in different conformations in the various subunits, resulting in the Glu166 side chain being rotated out of the active site or even in displacement of its Cα atom up to approximately 10 Å. A BEL-1 variant showing the single Leu162Phe substitution (BEL- 2) confers a higher level of resistance to CAZ, CTX, and FEP and shows significantly lower Km values than BEL-1, especially with oxyiminocephalosporins. BEL-1 Leu162 is located at the beginning of the Ω-loop and is surrounded by Phe72, Leu139, and Leu148 (contact distances, 3.5 to 3.9 Å). This small hydrophobic cavity could not reasonably accommodate the bulkier Phe162 found in BEL-2 without altering neighboring residues or the Ω-loop itself, thus likely causing an important alteration of the enzyme kinetic properties

    Analisis Penggunaan Google Dan Pengaruhnya Terhadap Kinerja (Studi Pada Mahasiswa S-1 Angkatan 2013-2014 Program Studi Administrasi Bisnis Fakultas Ilmu Administrasi Universitas Brawijaya)

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    The goal of this study to analyzes influence esay to use Google, usefulness Google, and use Google towards bachelor degree performence. The sample in this study is university student bachelor degree on 2013-2014 level at Administration Business Department, Administration Scients Faculty in Brawijaya University. They are 164 university students using questionnaire as the instrument of this research. The result showed that easy of use Google has positif significant towards usefulness Google, esay of use Google has positif significance towards use Google, usefulness Google has positif significant towards use Google, use Google has positif significant toward university students\u27 performance. Further showed that use Google that used by university student. The used of Goggle is considered easy and useful, in implementation. This research showed a high assessment is easy and usefull Google on its use towards university student\u27s performence

    Cyanidiophyceae (Rhodophyta) Tolerance to Precious Metals: Metabolic Response to Palladium and Gold

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    Polyextremophilic red algae, which belong to the class Cyanidiophyceae, are adapted to live in geothermal and volcanic sites. These sites often have very high concentrations of heavy and precious metals. In this study, we assessed the capacity of three strains of Galdieria (G. maxima, G. sulphuraria, and G. phlegrea) and one strain of Cyanidium caldarium to tolerate different concentrations of precious metals, such as palladium (Cl4K2Pd) and gold (AuCl4K) by monitoring algal growths in cultures exposed to metals, and we investigated the algae potential oxidative stress induced by the metals. This work provides further understanding of metals responses in the Cyanidiophyceae, as this taxonomic class is developed as a biological refinement tool
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