95 research outputs found

    Chapter 9 Moral Responsibility and the Justification of Policies to Preserve Antimicrobial Effectiveness

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    Restrictive policies that limit antimicrobial consumption, including therapeutically justified use, might be necessary to tackle the problem of antimicrobial resistance. We argue that such policies would be ethically justified when forgoing antimicrobials constitutes a form of easy rescue for an individual. These are cases of mild and self-limiting infections in otherwise healthy patients whose overall health is not significantly compromised by the infection. In such cases, restrictive policies would be ethically justified because they would coerce individuals into fulfilling a moral obligation they independently have. However, to ensure that such justification is the strongest possible, states also have the responsibility to ensure that forgoing antimicrobials is as easy as possible for patients by implementing adequate compensation measures

    A New Strategy for Glioblastoma Treatment: In Vitro and In Vivo Preclinical Characterization of Si306, a Pyrazolo[3,4-d]Pyrimidine Dual Src/P-Glycoprotein Inhibitor

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    20siopenOverexpression of P-glycoprotein (P-gp) and other ATP-binding cassette (ABC) transporters in multidrug resistant (MDR) cancer cells is responsible for the reduction of intracellular drug accumulation, thus decreasing the efficacy of chemotherapeutics. P-gp is also found at endothelial cells' membrane of the blood-brain barrier, where it limits drug delivery to central nervous system (CNS) tumors. We have previously developed a set of pyrazolo[3,4-d]pyrimidines and their prodrugs as novel Src tyrosine kinase inhibitors (TKIs), showing a significant activity against CNS tumors in in vivo. Here we investigated the interaction of the most promising pair of drug/prodrug with P-gp at the cellular level. The tested compounds were found to increase the intracellular accumulation of Rho 123, and to enhance the efficacy of paclitaxel in P-gp overexpressing cells. Encouraging pharmacokinetics properties and tolerability in vivo were also observed. Our findings revealed a novel role of pyrazolo[3,4-d]pyrimidines which may be useful for developing a new effective therapy in MDR cancer treatment, particularly against glioblastoma.openFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Peơić, Milica; Schenone, SilviaFallacara, Anna Lucia; Zamperini, Claudio; Podolski-Renić, Ana; Dinić, Jelena; Stanković, Tijana; Stepanović, Marija; Mancini, Arianna; Rango, Enrico; Iovenitti, Giulia; Molinari, Alessio; Bugli, Francesca; Sanguinetti, Maurizio; Torelli, Riccardo; Martini, Maurizio; Maccari, Laura; Valoti, Massimo; Dreassi, Elena; Botta, Maurizio; Peơić, Milica; Schenone, Silvi

    The Role of Actin Turnover in Retrograde Actin Network Flow in Neuronal Growth Cones

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    The balance of actin filament polymerization and depolymerization maintains a steady state network treadmill in neuronal growth cones essential for motility and guidance. Here we have investigated the connection between depolymerization and treadmilling dynamics. We show that polymerization-competent barbed ends are concentrated at the leading edge and depolymerization is distributed throughout the peripheral domain. We found a high-to-low G-actin gradient between peripheral and central domains. Inhibiting turnover with jasplakinolide collapsed this gradient and lowered leading edge barbed end density. Ultrastructural analysis showed dramatic reduction of leading edge actin filament density and filament accumulation in central regions. Live cell imaging revealed that the leading edge retracted even as retrograde actin flow rate decreased exponentially. Inhibition of myosin II activity before jasplakinolide treatment lowered baseline retrograde flow rates and prevented leading edge retraction. Myosin II activity preferentially affected filopodial bundle disassembly distinct from the global effects of jasplakinolide on network turnover. We propose that growth cone retraction following turnover inhibition resulted from the persistence of myosin II contractility even as leading edge assembly rates decreased. The buildup of actin filaments in central regions combined with monomer depletion and reduced polymerization from barbed ends suggests a mechanism for the observed exponential decay in actin retrograde flow. Our results show that growth cone motility is critically dependent on continuous disassembly of the peripheral actin network

    Analysis of causes of a fault in a reinforced concrete multi-chamber tank at a waste water treatment plant, and the reinforcement measures applied

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    Przedstawiono przypadek awarii wielokomorowego, ĆŒelbetowego zbiornika oczyszczalni ƛciekĂłw podczas prĂłby szczelnoƛci. Przeprowadzona analiza wykazaƂa bƂędy konstrukcyjne zbiornika, ktĂłre podczas eksploatacji stwarzaƂyby powaĆŒne zagroĆŒenie bezpieczeƄstwa. Zaproponowano sposĂłb wzmocnienia zbiornika, ktĂłry zostaƂ z powodzeniem zrealizowany.A description is given of a case in which a fault was found in a multi-chamber reinforced concrete tank at a waste water treatment plant during a leakage test. Analysis revealed structural design errors which would have led to a serious safety risk while the tank was in use. A method of reinforcing the tank was proposed and successfully implemented

    Dual inhibitors as a new challenge for cancer multidrug resistance treatment

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    Background: Dual-targeting in cancer treatment by a single drug is an unconventional approach in relation to drug combinations. The rationale for the development of dual-targeting agents is to overcome incomplete efficacy and drug resistance frequently present when applying individual targeting agents. Consequently,-a more favorable outcome of cancer treatment is expected with dual-targeting strategies. Methods: We reviewed the literature, concentrating on the association between clinically relevant and/or novel dual inhibitors with the potential to modulate multidrug resistant phenotype of cancer cells, particularly the activity of P-glycoprotein. A balanced analysis of content was performed to emphasize the most important findings and optimize the structure of this review. Results: Two-hundred and forty-five papers were included in the review. The introductory part was interpreted by 9 papers. Tyrosine kinase inhibitors\u2019 role in the inhibition of P-glycoprotein and chemosensitization was illustrated by 87 papers. The contribution of natural-based compounds in overcoming multidrug resistance was reviewed using 92 papers, while specific dual inhibitors acting against microtubule assembling and/or topoisomerases were described with 55 papers. Eleven papers gave an insight into a novel and less explored approach with hybrid drugs. Their influence on P-glycoprotein and multidrug resistance was also evaluated. Conclusion: These findings bring into focus rational anticancer strategies with dual-targeting agents. Most evaluated synthetic and natural drugs showed a great potential in chemosensitization. Further steps in this direction are needed for the optimization of anticancer treatment

    New therapeutic strategy for overcoming multidrug resistance in cancer cells with pyrazolo[3,4‐d]pyrimidine tyrosine kinase inhibitors

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    none9siTyrosine kinase inhibitors (TKIs) often interact with the multidrug resistant (MDR) phenotype of cancer cells. In some cases, TKIs increase the susceptibility of MDR cancer cells to chemotherapy. As the overexpression of membrane transporter P‐glycoprotein (P‐gp) is the most com-mon alteration in MDR cancer cells, we investigated the effects of TKI pyrazolo[3,4‐d]pyrimidines on P‐gp inhibition in two cellular models comprising sensitive and corresponding MDR cancer cells (human non‐small cell lung carcinoma and colorectal adenocarcinoma). Tested TKIs showed collateral sensitivity by inducing stronger inhibition of MDR cancer cell line viability. Moreover, TKIs directly interacted with P‐gp and inhibited its ATPase activity. Their potential P‐gp binding site was proposed by molecular docking simulations. TKIs reversed resistance to doxorubicin and paclitaxel in a concentration‐dependent manner. The expression studies excluded the indirect effect of TKIs on P‐gp through regulation of its expression. A kinetics study showed that TKIs decreased P‐gp activity and this effect was sustained for seven days in both MDR models. Therefore, pyrazolo[3,4‐d]pyrimidines with potential for reversing P‐gp‐mediated MDR even in prolonged treatments can be considered a new therapeutic strategy for overcoming cancer MDR.openPodolski-renic A.; Dinic J.; Stankovic T.; Tsakovska I.; Pajeva I.; Tuccinardi T.; Botta L.; Schenone S.; Pesic M.Podolski-renic, A.; Dinic, J.; Stankovic, T.; Tsakovska, I.; Pajeva, I.; Tuccinardi, T.; Botta, L.; Schenone, S.; Pesic, M
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