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Mary Ann Foglio - One of the best experts on this subject based on the ideXlab platform.
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in silico in vitro and in vivo antitumor and anti inflammatory evaluation of a standardized alkaloid enriched fraction obtained from boehmeria caudata sw aerial parts
Molecules, 2020Co-Authors: Paula Pereira De Paiva, Julia Helena Bormio Nunes, Fabiana Regina Nonato, Ana Lucia Tasca Gois Ruiz, Rafael Rosolen Teixeira Zafred, Ilza Maria De Oliveira Sousa, Marcia Y Okubo, Daniel Fabio Kawano, Paula A Monteiro, Mary Ann FoglioAbstract:In the context of the cancer-inflammation relationship and the use of natural products as potential antitumor and anti-inflammatory agents, the alkaloid-enriched fraction of Boehmeriacaudata (BcAEF) aerial parts was evaluated. In vitro antiproliferative studies with human tumor cell lines showed high activity at low concentrations. Further investigation on NCI-H460 cells showed an Irreversible Effect on cell proliferation, with cell cycle arrest at G2/M phase and programmed cell death induction. Molecular docking studies of four alkaloids identified in BcAEF with colchicine’s binding site on β-tubulin were performed, suggesting (−)-C (15R)-hydroxycryptopleurine as the main inductor of the observed mitotic death. In vivo studies showed that BcAEF was able to reduce Ehrlich tumor volume progression by 30 to 40%. Checking myeloperoxidase activity, BcAEF reduced neutrophils migration towards the tumor. The in vivo anti-inflammatory activity was evaluated by chemically induced edema models. In croton oil-induced ear edema and carrageenan (CG)-induced paw edema models, BcAEF reduced edema around 70 to 80% together with inhibition of activation and/or migration of neutrophils to the inflammatory area. All together the results presented herein show BcAEF as a potent antitumor agent combining antiproliferative and anti-inflammatory properties, which could be further explored in (pre)clinical studies.
Paula Pereira De Paiva - One of the best experts on this subject based on the ideXlab platform.
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In silico, in vitro, and in vivo antitumor and anti-inflammatory evaluation of a standardized alkaloid-enriched fraction obtained from boehmeria caudata sw. aerial parts
'MDPI AG', 2021Co-Authors: Paula Pereira De Paiva, Nunes, Julia H. B., Nonato, Fabiana R., Ruiz, Ana L. T. G., Zafred, Rafael R. T., Sousa, Ilza M. O., Okubo, Márcia Y., Kawano, Daniel F., Monteiro, Paula A., Foglio, Mary A.Abstract:In the context of the cancer-inflammation relationship and the use of natural products as potential antitumor and anti-inflammatory agents, the alkaloid-enriched fraction of Boehmeriacaudata (BcAEF) aerial parts was evaluated. In vitro antiproliferative studies with human tumor cell lines showed high activity at low concentrations. Further investigation on NCI-H460 cells showed an Irreversible Effect on cell proliferation, with cell cycle arrest at G2/M phase and programmed cell death induction. Molecular docking studies of four alkaloids identified in BcAEF with colchicine’s binding site on β-tubulin were performed, suggesting (−)-C (15R)-hydroxycryptopleurine as the main inductor of the observed mitotic death. In vivo studies showed that BcAEF was able to reduce Ehrlich tumor volume progression by 30 to 40%. Checking myeloperoxidase activity, BcAEF reduced neutrophils migration towards the tumor. The in vivo anti-inflammatory activity was evaluated by chemically induced edema models. In croton oil-induced ear edema and carrageenan (CG)-induced paw edema models, BcAEF reduced edema around 70 to 80% together with inhibition of activation and/or migration of neutrophils to the inflammatory area. All together the results presented herein show BcAEF as a potent antitumor agent combining antiproliferative and anti-inflammatory properties, which could be further explored in (pre)clinical studies2517CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP#158904/2012-5#1143100#2017/21801-2; #2012/19661-4; #2004/15410-0; #2011/22458–3; #2011/22457-7; #2014/06636-
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in silico in vitro and in vivo antitumor and anti inflammatory evaluation of a standardized alkaloid enriched fraction obtained from boehmeria caudata sw aerial parts
Molecules, 2020Co-Authors: Paula Pereira De Paiva, Julia Helena Bormio Nunes, Fabiana Regina Nonato, Ana Lucia Tasca Gois Ruiz, Rafael Rosolen Teixeira Zafred, Ilza Maria De Oliveira Sousa, Marcia Y Okubo, Daniel Fabio Kawano, Paula A Monteiro, Mary Ann FoglioAbstract:In the context of the cancer-inflammation relationship and the use of natural products as potential antitumor and anti-inflammatory agents, the alkaloid-enriched fraction of Boehmeriacaudata (BcAEF) aerial parts was evaluated. In vitro antiproliferative studies with human tumor cell lines showed high activity at low concentrations. Further investigation on NCI-H460 cells showed an Irreversible Effect on cell proliferation, with cell cycle arrest at G2/M phase and programmed cell death induction. Molecular docking studies of four alkaloids identified in BcAEF with colchicine’s binding site on β-tubulin were performed, suggesting (−)-C (15R)-hydroxycryptopleurine as the main inductor of the observed mitotic death. In vivo studies showed that BcAEF was able to reduce Ehrlich tumor volume progression by 30 to 40%. Checking myeloperoxidase activity, BcAEF reduced neutrophils migration towards the tumor. The in vivo anti-inflammatory activity was evaluated by chemically induced edema models. In croton oil-induced ear edema and carrageenan (CG)-induced paw edema models, BcAEF reduced edema around 70 to 80% together with inhibition of activation and/or migration of neutrophils to the inflammatory area. All together the results presented herein show BcAEF as a potent antitumor agent combining antiproliferative and anti-inflammatory properties, which could be further explored in (pre)clinical studies.
D.d.l. Chung - One of the best experts on this subject based on the ideXlab platform.
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Electric polarization and depolarization of solder, and their Effects on electrical conduction
Journal of Materials Science: Materials in Electronics, 2021Co-Authors: Wenyi Yang, D.d.l. ChungAbstract:This work provides the first report of the Effect of the dielectric behavior on the conduction behavior of solder. The lead-free solder studied contains 96 wt% tin and 4 wt% silver. The electric polarization stems from the interaction of the valence electrons with the atoms. The fraction of valence electrons that participate in the initial polarization is of the order of 10^–9. The injected electrons play a minor role compared to the valence electrons of the solder in the polarization. The efficiency of the injected electrons in promoting the polarization decreases with the increasing number of injected electrons. Due to the polarization under a constant applied DC current (30–100 mA), the apparent electrical resistivity increases beyond the true resistivity. The rate of apparent resistivity increase diminishes as the time of current application increases. The fractional increase is 0.10% at 130 s of 100-mA current application. The higher is the current, the greater are the degree and rate of polarization at a given time. The current Effect saturates above ~ 90 mA. Upon reversal of the polarity of the applied current, depolarization (followed by reverse polarization) occurs. The rates of depolarization and reverse polarization, as indicated by the rate of apparent resistivity increase, increase with increasing current. These rates decrease with increasing time. At the same current and respective time, the rates of polarization and depolarization are essentially equal, but the rate of reverse polarization is much below that of the initial polarization. Furthermore, the nearly saturated degree of reverse polarization is much below that of the initial polarization. This indicates a partially Irreversible Effect of the initial polarization that hinders the reverse polarization.
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A critical review of piezoresistivity and its application in electrical-resistance-based strain sensing
Journal of Materials Science, 2020Co-Authors: D.d.l. ChungAbstract:Piezoresistivity is an electromechanical Effect characterized by the reversible change in the electrical resistivity with strain. It is useful for electrical-resistance-based strain/stress sensing. The resistivity can be the volumetric, interfacial or surface resistivity, though the volumetric resistivity is most meaningful scientifically. Because the Irreversible resistivity change (due to damage or an Irreversible microstructural change) adds to the reversible change that occurs at lower strains, the inclusion of the Irreversible Effect makes the piezoresistivity appear stronger than the inherent Effect. This paper focuses on the inherent piezoresistivity that occurs without Irreversible resistivity changes. The Effect is described by the gage factor (GF), which is defined as the fractional change in resistance per unit strain. The GF can be positive or negative. Strong piezoresistivity involves the magnitude of the fractional change in resistivity much exceeding the strain magnitude. The reversible Effect of strain on the electrical connectivity is the primary piezoresistivity mechanism. Giant piezoresistivity is characterized by GF ≥ 500. This critical review with 209 references covers the theory, mechanisms, methodology and status of piezoresistivity, and provides the first review of the emerging field of giant piezoresistivity. Piezoresistivity is exhibited by electrically conductive materials, particularly metals, carbons and composite materials with conductive fillers and nonconductive matrices. They include functional and structural materials. Piezoresistivity enables structural materials to be self-sensing. Unfortunately, GF was incorrectly or unreliably reported in a substantial fraction of the publications, due to the pitfalls systematically presented here. The most common pitfall involves using the two-probe method for the resistance measurement.
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through thickness piezoresistivity in a carbon fiber polymer matrix structural composite for electrical resistance based through thickness strain sensing
Carbon, 2013Co-Authors: Daojun Wang, D.d.l. ChungAbstract:Piezoresistivity (change of the volume electrical resistivity with strain) in continuous carbon fiber polymer-matrix structural composites allows electrical-resistance-based strain/stress sensing. Uniaxial through-thickness compression is encountered in fastening. As shown for a 24-lamina quasi-isotropic epoxy-matrix composite, compression results in (i) strain-induced reversible decreases in through-thickness and longitudinal volume resistivities, due to increase in the degree of through-thickness fiber–fiber contact, and (ii) minor-damage-induced Irreversible changes in these resistivities, due to a microstructural change involving an Irreversible through-thickness resistivity increase and an Irreversible longitudinal resistivity decrease. The Poisson Effect plays a minor role. The Effects in the longitudinal resistivity are small compared to those in the through-thickness direction, but longitudinal resistance measurement is more practical. The through-thickness gage factor (reversible fractional change in resistance per unit strain) ranges from 2.6 to 5.1 and the reversible fractional change in through-thickness resistivity per unit through-thickness strain ranges from 1.5 to 4.0, both quantities decreasing with increasing strain magnitude from 0.19% to 0.73% due to the increasing Irreversible Effect. The Irreversible fractional change in through-thickness resistivity per unit through-thickness strain ranges from −1.0 to −1.3 and is strain independent. The Effects are consistent with the surface resistance changes previously reported for the same material under flexure.
Joshua Zimmerberg - One of the best experts on this subject based on the ideXlab platform.
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Irreversible Effect of cysteine protease inhibitors on the release of malaria parasites from infected erythrocytes
Cellular Microbiology, 2009Co-Authors: Svetlana Glushakova, Julia Mazar, Martin F. Hohmann-marriott, Erinn Hama, Joshua ZimmerbergAbstract:Summary By studying the inactivation of malaria parasite culture by cysteine protease inhibition using confocal microscopy of living cells and electron microscopy of high-pressure frozen and freeze- substituted cells, we report the precise step in the release of malaria parasites from erythrocytes that is likely regulated by cysteine proteases: the opening of the erythrocyte membrane, liberating parasites for the next round of infection. Inhibition of cysteine proteases within the last few minutes of cycle does not affect rupture of the parasitophorus vacuole but irreversibly blocks the subsequent rupture of the host cell membrane, locking in resi- dent parasites, which die within a few hours of captivity. This Irreversible inactivation of mature parasites inside host cells makes plasmodial cys- teine proteases attractive targets for antimalarials, as parasite-specific cysteine protease inhibitors may significantly augment multi-target drug cocktails.
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evidence for the hiv 1 phenotype switch as a causal factor in acquired immunodeficiency
Nature Medicine, 1998Co-Authors: Svetlana Glushakova, Jeancharles Grivel, Wendy Fitzgerald, Andrew W Sylwester, Joshua Zimmerberg, Leonid MargolisAbstract:Both cellular and humoral immunodeficiency develop in vivo after prolonged infection with HIV-1, but the mechanisms are unclear1. Initial infection with HIV-1 is transmitted by macrophage (M)-tropic/non-syncytia-inducing (NSI) viruses2,3, which hyperactivate the immune system4,5, and, in one view, cause immunodeficiency by “exhaustion”4,6 of lymphoid tissue. An alternative hypothesis is that immunodeficiency is caused by the replacement of M-tropic viruses by T cell (T)-tropic/syncytia-inducing (SI) viruses, which are known to be highly cytopathic in vitro and emerge late in infected individuals around the time of transition to AIDS (refs. 1, 7–9). To test these two possibilities, we have developed an ex vivo model of humoral immunity to recall antigens using human lymphoid tissue. This tissue suppo rts productive infection with both M- and T-tropic HIV-1 isolates when cultured ex vivo10,11. We found that specific immune responses were enhanced by productive infection of the tissue with M-tropic/NSI HIV-1 isolates, but were blocked by T-tropic/SI HIV-1 isolates. The mechanism involves specific Irreversible Effect on B-cell activity. Our results support the hypothesis that the phenotype switch to T-tropic viruses is a key determinant of acquired humoral immunodeficiency in patients infected with HIV.
Rafael Rosolen Teixeira Zafred - One of the best experts on this subject based on the ideXlab platform.
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in silico in vitro and in vivo antitumor and anti inflammatory evaluation of a standardized alkaloid enriched fraction obtained from boehmeria caudata sw aerial parts
Molecules, 2020Co-Authors: Paula Pereira De Paiva, Julia Helena Bormio Nunes, Fabiana Regina Nonato, Ana Lucia Tasca Gois Ruiz, Rafael Rosolen Teixeira Zafred, Ilza Maria De Oliveira Sousa, Marcia Y Okubo, Daniel Fabio Kawano, Paula A Monteiro, Mary Ann FoglioAbstract:In the context of the cancer-inflammation relationship and the use of natural products as potential antitumor and anti-inflammatory agents, the alkaloid-enriched fraction of Boehmeriacaudata (BcAEF) aerial parts was evaluated. In vitro antiproliferative studies with human tumor cell lines showed high activity at low concentrations. Further investigation on NCI-H460 cells showed an Irreversible Effect on cell proliferation, with cell cycle arrest at G2/M phase and programmed cell death induction. Molecular docking studies of four alkaloids identified in BcAEF with colchicine’s binding site on β-tubulin were performed, suggesting (−)-C (15R)-hydroxycryptopleurine as the main inductor of the observed mitotic death. In vivo studies showed that BcAEF was able to reduce Ehrlich tumor volume progression by 30 to 40%. Checking myeloperoxidase activity, BcAEF reduced neutrophils migration towards the tumor. The in vivo anti-inflammatory activity was evaluated by chemically induced edema models. In croton oil-induced ear edema and carrageenan (CG)-induced paw edema models, BcAEF reduced edema around 70 to 80% together with inhibition of activation and/or migration of neutrophils to the inflammatory area. All together the results presented herein show BcAEF as a potent antitumor agent combining antiproliferative and anti-inflammatory properties, which could be further explored in (pre)clinical studies.
