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Romecin, P. A., J. E. Millán, A. B. Meseguer, M. C. Ortiz, F. Gragnolini, E. M. García, N. Atucha, and J. García-Estañn. "533 INCREASED PLATELET REACTIVE OXIGEN SPECIES (ROS) PRODUCTION IN EXPERIMENTAL CIRRHOSIS." Journal of Hepatology 52 (April 2010): S213—S214. http://dx.doi.org/10.1016/s0168-8278(10)60535-1.
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Sawayama, Yasushi, Yasushi Miyazaki, Chizuko Tsutsumi, Koji Ando, Kazutaka Kuriyama, and Masao Tomonaga. "Myeloperoxidase Increases Chemosensitivity of Leukemia Cells through the Generation of Reactive Oxigen and Nitrogen Species." Blood 108, no. 11 (November 16, 2006): 4506. http://dx.doi.org/10.1182/blood.v108.11.4506.4506.
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Abstract Myeloperoxidase (MPO) is a specific enzyme whose expression is restricted to the late stage of myeloid differentiation such as promyelocytes and more matured cells. In a pathological situation, however, morphologically immature blasts of acute myeloid leukemia (AML) express MPO at variety of percentages that has been utilized for the diagnosis of AML. On the other hand, the expression of MPO has been shown to have prognostic value for AML cases. Several groups including ours reported that the high percentage of MPO positive blasts at diagnosis was related to the favorable prognosis. Recently, we also found that the expression of the MPO gene in CD133 positive cells also related to the better prognosis of AML cases, suggesting the MPO in the very immature fraction, that is thought to contain leukemia stem cells, is related to the chemosensitivity of AML cells. These results made us hypothesize that MPO directly changes chemosensitivity of leukemia cells through its enzymatic activity. To test this hypothesis, we transfected wild type and enzymaticaly defective MPO (dMPO) cDNA into MPO-negative leukemia cells line, K562, generating K562-MPO and K562-dMPO. Control cells were K562-vector that were transfected with empty vector. The expression of MPO protein was shown in K562-MPO cells, but only precursor of MPO protein, apo-pro-MPO was expressed in K562-dMPO cells as expected. The enzymatic activity was shown only in K562-MPO cells. When these cells were treated with cytosine arabinoside (AraC), K562-MPO cells showed decreased proliferation by WST1 assay compared with wild type K562, K562-vector and K562-dMPO. The expression of Annexin V was increased in AraC-treated K562-MPO suggesting these cells died through apoptosis. Using flowcytometer or confocal microscopy with aminophenyl fluorescein (APF), reactive oxygen species (ROS) were detected in wild type K562 and K562-MPO cells after treatment with AraC. The amount of ROS shown by the intensity of APF-fluorescence increased more in K562-MPO compared with wild type K562 or K562-vector. The difference in the APF-fluorescence observed AraC-treated K562-vector and K562-MPO cells was strongly enhanced by the addition of hydrogen peroxide as a donor of ROS. However, this difference completely disappeared with the addition of N-acetyl cystein (NAC), an inhibitor of ROS, suggesting the involvement of MPO to generate ROS in K562-MPO cells. Although flowcytometer with DAF-2DA failed to detect the significant differences in the amount of reactive nitrogen species (RNS) among AraC-treated wild type K562, K562-vector and K562-MPO cells, immunoblotting against the nitrated tyrosine residue demonstrated the increased nitration of protein in K562-MPO cells compared with wild type or K562-vector. It was suggested that RNS was generated in K562-MPO treated with AraC. These results supported our working hypothesis that MPO in leukemia cells enhanced the sensitivity against chemotherapeutic agents through the generation of ROS and RNS.
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Butsanets, P., A. Baik, N. Shugaeva, and A. Shugaev. "EFFECT OF SALICYLIC ACID ON RESPIRATORY ACTIVITY AND REACTIVE OXIGEN SPECIES GENERATION IN PLANT MITOCHONDRIA." EurasianUnionScientists 2, no. 10(79) (November 20, 2020): 9–15. http://dx.doi.org/10.31618/esu.2413-9335.2020.2.79.1043.
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The aim of this work was to study the effect of a stress phytohormone, salicylic acid (SA), on respiration and generation of reactive oxygen species (ROS) in mitochondria isolated from the cotyledons of lupine seedlings (Lupinus angustifolius L.) and stored taproots of sugar beet (Beta vulgaris L.). Mitochondria were isolated by differential centrifugation, respiration of organelles was measured polarographically using a Clark-type oxygen electrode, and the formation of ROS (hydrogen peroxide) in mitochondria was determined using a fluorogenic dye 2,7-dichlorodihydrofluorescein diacetate (DCFDA). The results obtained showed that SA is capable of exerting a direct regulatory effect on the main parameters of the oxidative phosphorylation process (the rate of substrate oxidation, the value of respiratory control and the ADP/O coefficient), as well as on the formation of ROS. It was shown for the first time that the character of the SA action on mitochondrial metabolism depends not only on the phytohormone concentration, but also on the functional state of the organelles, which is determined by the specificity of the metabolism of tissues and organs from which they were isolated.
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Granato, Marisa, Maria Gilardini Montani, Camilla Angiolillo, Gabriella D’Orazi, Alberto Faggioni, and Mara Cirone. "Cytotoxic Drugs Activate KSHV Lytic Cycle in Latently Infected PEL Cells by Inducing a Moderate ROS Increase Controlled by HSF1, NRF2 and p62/SQSTM1." Viruses 11, no. 1 (December 24, 2018): 8. http://dx.doi.org/10.3390/v11010008.
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Previous studies have indicated that cytotoxic treatments may induce or not activate viral lytic cycle activation in cancer cells latently infected by Kaposi’s sarcoma-associated herpesvirus (KSHV). To investigate the molecular mechanisms responsible for such an effect, we compared two cytotoxic treatments able to induce the viral lytic cycle, named 12-O-tetradecanoylphorbol 13-acetate (TPA) (T) in combination with sodium butyrate (B) and bortezomib (BZ), with two cytotoxic treatments that did not activate this process, named metformin (MET) and quercetin (Q). Our results indicated that TB and bortezomib increased levels of oxygen reactive species (ROS) while metformin and quercetin reduced them. The finding that N-acetylcysteine (NAC), a reactive oxigen species (ROS) scavenger, counteracted K-bZIP expression induced by TB or bortezomib, confirmed that an ROS increase played a role in KSHV lytic cycle activation. Moreover, we found that TB and bortezomib up-regulated p62/Sequestosome1(p62/SQSTM1) protein, while metformin and quercetin down-regulated it. p62/SQSTM1 silencing or the inhibition of NF-E2-related factor 2 (NRF2) or Heat Shock Factor 1 (HSF1), that mediate p62/SQSTM1 transcription, also reduced KSHV lytic antigen expression induced by TB or bortezomib. Interestingly, such combination treatments further increased intracellular ROS and cytotoxicity induced by the single TB or bortezomib treatment, suggesting that NRF2, HSF1 and p62/SQSTM1 keep the ROS level under control, allowing primary effusion lymphoma (PEL) cells to continue to survive and KSHV to replicate.
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LEVY-PEREIRA, Nycolas, Ricardo Luiz Moro de SOUSA, Roberson SAKABE, Fernanda de Alexandre SEBASTIÃO, Elisabeth Criscuolo URBINATI, and Fabiana PILARSKI. "DIETARY MANNAN-OLIGOSACCHARIDE INCREASES REACTIVE OXIGEN SPECIES PRODUCTION BUT DECREASES SERUM LYSOZYME IN HIGH LEVELS OF INCLUSION FOR NILE TILAPIA." Boletim do Instituto de Pesca 46, no. 3 (December 16, 2020): 1–7. http://dx.doi.org/10.20950/1678-2305.2020.46.3.551.
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In the present experiment, the effects of mannan-oligosaccharide (MOS) on health and growth of Nile tilapia juveniles were investigated. In addition to the control treatment (without MOS),three levels of MOS were included in Nile tilapia diets (1, 8, and 15 g kg−1), and hematology, reactive oxygen species (ROS) production, lysozyme and productive parameters were analyzed. Fish blood was sampled at day zero (basal sample) and after 60 days of trial, and the productive parameters were evaluated at the end of the experiment. MOS feeding decreased the feed consumption (p = 0.0299) in fish fed with 1 and 8 g kg-1, but without any alteration in weight gain (WG) and feed conversion ratio (FCR). No changes were observed in the hematology due to MOS feeding after 60 days. However, the prebiotic caused changes in the innate immunity of fish, giving rise to ROS production in fish fed with 1 g kg-1 (p<0.0001) and decreasing the serum lysozyme activity of fish fed with 15 g kg-1 (p<0.0001). In conclusion, the authors recommend the inclusion of 1 g kg-1 for Nile tilapia juveniles feeding due to the positive effect in innate immune system.
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Dreyer, Maik, Anna Rabe, Eko Budiyanto, Klaus Friedel Ortega, Sharif Najafishirtari, Harun Tüysüz, and Malte Behrens. "Dynamics of Reactive Oxygen Species on Cobalt-Containing Spinel Oxides in Cyclic CO Oxidation." Catalysts 11, no. 11 (October 29, 2021): 1312. http://dx.doi.org/10.3390/catal11111312.
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Reactive oxygen species (ROS) are considered to be responsible for the high catalytic activity of transition metal oxides like Co3-xFexO4 in oxidation reactions, but the detailed influences of catalyst composition and morphology on the formation of these reactive oxygen species are not fully understood. In the presented study, Co3O4 spinels of different mesostructures, i.e., particle size, crystallinity, and specific surface area, are characterized by powder X-ray diffraction, scanning electron microscopy, and physisorption. The materials were tested in CO oxidation performed in consecutive runs and compared to a Co3-xFexO4 composition series with a similar mesostructure to study the effects of catalyst morphology and composition on ROS formation. In the first run, the CO conversion was observed to be dominated by the exposed surface area for the pure Co-spinels, while a negative effect of Fe content in the spinels was seen. In the following oxidation run, a U-shaped conversion curve was observed for materials with high surface area, which indicated the in situ formation of ROS on those materials that were responsible for the new activity at low temperature. This activation was not stable at the higher reaction temperature but was confirmed after temperature-programmed oxidation (TPO). However, no activation after the first run was observed for low-surface-area and highly crystalline materials, and the lowest surface-area material was not even activated after TPO. Among the catalyst series studied here, a correlation of small particle size and large surface area with the ability for ROS formation is presented, and the benefit of a nanoscaled catalyst is discussed. Despite the generally negative effect of Fe, the highest relative activation was observed at intermediate Fe contents suggesting that Fe may be involved in ROS formation.
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Iannuzzi, Anna Maria, Chiara Giacomelli, Marinella De Leo, Lara Russo, Fabiano Camangi, Nunziatina De Tommasi, Alessandra Braca, Claudia Martini, and Maria Letizia Trincavelli. "Cornus sanguinea Fruits: a Source of Antioxidant and Antisenescence Compounds Acting on Aged Human Dermal and Gingival Fibroblasts." Planta Medica 87, no. 10/11 (April 15, 2021): 879–91. http://dx.doi.org/10.1055/a-1471-6666.
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AbstractFive new compounds, a flavonol glycoside ( 1), a megastigmane ( 2), 2 cyclohexylethanoids ( 3, 4), and a phenylethanoid derivative ( 5), together with 15 known compounds ( 6– 20) including flavonoid glycosides, cyclohexylethanoids, and phenolic compounds, have been isolated from Cornus sanguinea drupes. All the structures have been determined by 1D and 2D NMR spectroscopic analysis and mass spectrometry data. The antioxidant capability of the most representative isolated compounds was evaluated in the hydrogen peroxide (H2O2)-induced premature cellular senescence model of human dermal and gingival fibroblasts. Several derivatives counteracted the increase of reactive oxigen species (ROS) production in both cellular models. Among the most promising, compounds 8, 14, and 20 were able to counteract cell senescence, decreasing the expression of p21 and p53. Furthermore, compound 14 decreased the expression of inflammatory cytokines (IL-6) in both cell models and counteracted the decrease of collagen expression induced by the H2O2 in dermal human fibroblasts. These data highlight the anti-aging properties of several isolated compounds from C. sanguinea drupes, supporting its possible use in the cure of skin or periodontitis lesions.
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Imelda, Eva, Rinaldi Idroes, Khairan Khairan, Rodiah Rahmawaty Lubis, Abdul Hawil Abas, Ade John Nursalim, Mohamad Rafi, and Trina Ekawati Tallei. "Natural Antioxidant Activities of Plants in Preventing Cataractogenesis." Antioxidants 11, no. 7 (June 28, 2022): 1285. http://dx.doi.org/10.3390/antiox11071285.
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A cataract is a condition that causes 17 million people to experience blindness and is the most significant cause of vision loss, around 47.9%. The formation of cataracts is linked to both the production of reactive oxygen species (ROS) and the reduction of endogenous antioxidants. ROS are highly reactive molecules produced by oxygen. Examples of ROS include peroxides, super-oxides, and hydroxyl radicals. ROS are produced in cellular responses to xenobiotics and bacterial invasion and during mitochondrial oxidative metabolism. Excessive ROS can trigger oxidative stress that initiates the progression of eye lens opacities. ROS and other free radicals are highly reactive molecules because their outer orbitals have one or more unpaired electrons and can be neutralized by electron-donating compounds, such as antioxidants. Examples of natural antioxidant compounds are vitamin C, vitamin E, and beta-carotene. Numerous studies have demonstrated that plants contain numerous antioxidant compounds that can be used as cataract preventatives or inhibitors. Natural antioxidant extracts for cataract therapy may be investigated further in light of these findings, which show that consuming a sufficient amount of antioxidant-rich plants is an excellent approach to cataract prevention. Several other natural compounds also prevent cataracts by inhibiting aldose reductase and preventing apoptosis of the eye lens.
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Altaf, Muhammad, Naike Casagrande, Elena Mariotto, Nadeem Baig, Abdel-Nasser Kawde, Giuseppe Corona, Roberto Larcher, et al. "Potent In Vitro and In Vivo Anticancer Activity of New Bipyridine and Bipyrimidine Gold (III) Dithiocarbamate Derivatives." Cancers 11, no. 4 (April 4, 2019): 474. http://dx.doi.org/10.3390/cancers11040474.
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We synthesized eight new bipyridine and bipyrimidine gold (III) dithiocarbamate-containing complexes (C1–C8) and tested them in a panel of human cancer cell lines. We used osteosarcoma (MG-63), lung (A549), prostate (PC3 and DU145), breast (MCF-7), ovarian (A2780 and A2780cis, cisplatin- and doxorubicin-resistant), and cervical (ME-180 and R-ME-180, cisplatin resistant) cancer cell lines. We found that C2, C3, C6, and C7 were more cytotoxic than cisplatin in all cell lines tested and overcame cisplatin and doxorubicin resistance in A2780cis and R-ME-180 cells. In the PC3 prostate cancer cell line, the gold (III) complex C6 ([Au2(BPM)(DMDTC)2]Cl4) induced apoptosis and double-stranded DNA breaks, modified cell cycle phases, increased Reactive Oxigen Species (ROS) generation, and reduced thioredoxin reductase and proteasome activities. It inhibited PC3 cell migration and was more cytotoxic against PC3 cells than normal human adipose-derived stromal cells. In mice bearing PC3 tumor xenografts, C6 reduced tumor growth by more than 70% without causing weight loss. Altogether, our results demonstrate the anticancer activity of these new gold (III) complexes and support the potential of C6 as a new agent for prostate cancer treatment.
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Misra, A. N., M. Misra, and R. Singh. "Nitric oxide ameliorates stress responses in plants." Plant, Soil and Environment 57, No. 3 (March 4, 2011): 95–100. http://dx.doi.org/10.17221/202/2010-pse.
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Nitric oxide (NO) is a gaseous diatomic molecule with a wide variety of physiological and pathological implications in plants. Presence of unpaired electron in its molecular orbital makes it highly reactive; it can react directly with metal complexes, radicals, DNA, proteins, lipids and other biomolecules. Nitric oxide (NO) and reactive oxygen species (ROS) are known to play essential role in a number of important plant physiological processes. This manuscript reviews the role of NO on these processes during various biotic and abiotic stresses.
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Luthfi, Muhammad, Retno Indrawati, Ira Arundina, and Yoes Prijatna Dachlan. "Korelasi Jumlah Streptococcus mutans (S. mutans) dan Level Ekspresi Interlukin 8 (IL-8) pada Severe Early Childhood Caries." Majalah Kedokteran Gigi Indonesia 20, no. 2 (December 1, 2015): 142. http://dx.doi.org/10.22146/majkedgiind.9227.
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Karies gigi pada anak usia dini merupakan masalah kesehatan yang sangat serius karena merupakan penyakit infeksi kronis yang menular. Dalam beberapa tahun terakhir pandangan tentang neutrofil telah berubah secara dramatis. Neutrofil tidak hanya berperan sebagai pembunuh mikroba melalui proses fagositosis, pelepasan reactive oxigen species (ROS) dan peptida antimikrobialnya tetapi neutrofil turut mengatur aktifasi respon imun. Interleukin-8 (IL-8) berfungsi sebagai aktivator kuat dan kemoatraktan neutrofil oleh karena itu IL-8 merupakan mediator kunci dalam migrasi neutrofil ke lokasi peradangan dan infeksi. Untuk menganalisis hubungan dari jumlah S. mutans dan ekspresi IL-8 neutrofil saliva pada anak usia dini bebas karies dan severe early childhood caries (S-ECC). Perlakuan dilakukan pada dua kelompok yaitu isolasi dan menghitung jumlah S. mutans pada sampel saliva dan sampel hasil kumur dengan NaCl 1,5% yang diisolasi neutrofilnya kemudian dianalisis ekspresi IL-8 menggunakan flow cytometry dari 20 anak bebas karies dan 20 anak severe early childhood caries. Hasil nilai rata-rata diketahui bahwa jumlah S. mutans anak usia dini bebas karies lebih rendah (513.500,00±185.565,28 CFU/ml) dibandingkan dengan S-ECC (977.000,00±222.500,15 CFU/ml), sedangkan ekspresi IL-8 neutrofil saliva anak usia dini bebas karies lebih tinggi (3,31±0,50) dibandingkan dengan S-ECC (2,95+0,56). Penurunan ekspresi IL-8 neutrofil saliva kemungkinan sebagai penyebab meningkatnya jumlah S. mutans pada S-ECC.Correlation of Streptococcus mutans (S. mutans) Level and Interleukin 8 (IL-8) Expressions of Salivary Neutrophils in Severe Early Childhood Caries. Early childhood caries is a very serious health problem because it is a chronic infectious disease that is contagious. Dental caries begins after the primary teeth grow and develop on the tooth surface very quickly and progressively. In recent years the views of neutrophils have changed dramatically. Neutrophils not only act as a microbe killer through phagocytosis, the release of reactive oxigen species (ROS) and its antimicrobial peptide, but neutrophil activation also helps regulate the immune response. To analyze the relationship between the amount S. mutans and IL-8 expression of salivary neutrophils in severe early Childhood caries. Two groups, namely Isolation of S. mutans were performed on saliva samples taken from 20 caries-free and 20 severe early childhood caries and samples Nacl 1,5% mouthwash results of 20 caries-free and 20 severe early childhood caries salivary neutrophils that were analysis of IL-8 expression by flow cytometry. Based on the average value, it is known that S. mutans level in early Childhood caries-free is lower (513.500,00 +185.565,28 CFU/ml) in comparison to the severe early Childhood caries (977.000,00 +222.500,15 CFU/ml), but the expression of IL-8 neutrophil salivary neutrophils in early Childhood caries-free is higher (3,31+0,50) in comparison to the severe early Childhood caries (2,95+0,56). The increased S. mutans level is probably caused by the decrease in the expression of IL-8 salivary neutrophils in severe early childhood caries.
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Poljšak, Borut, and Rok Fink. "The Protective Role of Antioxidants in the Defence against ROS/RNS-Mediated Environmental Pollution." Oxidative Medicine and Cellular Longevity 2014 (2014): 1–22. http://dx.doi.org/10.1155/2014/671539.
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Overproduction of reactive oxygen and nitrogen species can result from exposure to environmental pollutants, such as ionising and nonionising radiation, ultraviolet radiation, elevated concentrations of ozone, nitrogen oxides, sulphur dioxide, cigarette smoke, asbestos, particulate matter, pesticides, dioxins and furans, polycyclic aromatic hydrocarbons, and many other compounds present in the environment. It appears that increased oxidative/nitrosative stress is often neglected mechanism by which environmental pollutants affect human health. Oxidation of and oxidative damage to cellular components and biomolecules have been suggested to be involved in the aetiology of several chronic diseases, including cancer, cardiovascular disease, cataracts, age-related macular degeneration, and aging. Several studies have demonstrated that the human body can alleviate oxidative stress using exogenous antioxidants. However, not all dietary antioxidant supplements display protective effects, for example,β-carotene for lung cancer prevention in smokers or tocopherols for photooxidative stress. In this review, we explore the increases in oxidative stress caused by exposure to environmental pollutants and the protective effects of antioxidants.
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Kessler, Amanda, Jonas Hedberg, Eva Blomberg, and Inger Odnevall. "Reactive Oxygen Species Formed by Metal and Metal Oxide Nanoparticles in Physiological Media—A Review of Reactions of Importance to Nanotoxicity and Proposal for Categorization." Nanomaterials 12, no. 11 (June 4, 2022): 1922. http://dx.doi.org/10.3390/nano12111922.
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Diffusely dispersed metal and metal oxide nanoparticles (NPs) can adversely affect living organisms through various mechanisms and exposure routes. One mechanism behind their toxic potency is their ability to generate reactive oxygen species (ROS) directly or indirectly to an extent that depends on the dose, metal speciation, and exposure route. This review provides an overview of the mechanisms of ROS formation associated with metal and metal oxide NPs and proposes a possible way forward for their future categorization. Metal and metal oxide NPs can form ROS via processes related to corrosion, photochemistry, and surface defects, as well as via Fenton, Fenton-like, and Haber–Weiss reactions. Regular ligands such as biomolecules can interact with metallic NP surfaces and influence their properties and thus their capabilities of generating ROS by changing characteristics such as surface charge, surface composition, dissolution behavior, and colloidal stability. Interactions between metallic NPs and cells and their organelles can indirectly induce ROS formation via different biological responses. H2O2 can also be generated by a cell due to inflammation, induced by interactions with metallic NPs or released metal species that can initiate Fenton(-like) and Haber–Weiss reactions forming various radicals. This review discusses these different pathways and, in addition, nano-specific aspects such as shifts in the band gaps of metal oxides and how these shifts at biologically relevant energies (similar to activation energies of biological reactions) can be linked to ROS production and indicate which radical species forms. The influences of kinetic aspects, interactions with biomolecules, solution chemistry (e.g., Cl− and pH), and NP characteristics (e.g., size and surface defects) on ROS mechanisms and formation are discussed. Categorization via four tiers is suggested as a way forward to group metal and metal oxide NPs based on the ROS reaction pathways that they may undergo, an approach that does not include kinetics or environmental variations. The criteria for the four tiers are based on the ability of the metallic NPs to induce Fenton(-like) and Haber–Weiss reactions, corrode, and interact with biomolecules and their surface catalytic properties. The importance of considering kinetic data to improve the proposed categorization is highlighted.
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Ivanova, Anna O., Sergey V. Andreev, Michail Y. Soloveyev, and Konstantin A. Sacharov. "Disinfecting effect of nanoscale photocatalysts: a brief review." Disinfection affairs, no. 2 (June 2022): 19–29. http://dx.doi.org/10.35411/2076-457x-2022-2-19-29.
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This review describes nanosized particles of metals, oxides and organic substances that can act as effective disinfectants when irradiated with ultraviolet and visible light. Such an effect is due to photocatalytic action, namely the release of reactive oxygen species, leading to oxidative stress in pathogenic microflora. The review gives a description of the physical and chemical principles of such particles, the variety of their types, methods of their synthesis, and examples of their application. The data from the articles of the last few years from the leading international scientific journals are cited and promising directions for further work are outlined. Keywords: titanium dioxide, zinc oxide, copper oxide, nanopowders, nanoparticles, photocatalysts, reactive oxygen species (ROS), antimicrobial properties, resistance, oxidative stres.
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Cacaci, Margherita, Damiano Squitieri, Valentina Palmieri, Riccardo Torelli, Giordano Perini, Michela Campolo, Maura Di Vito, et al. "Curcumin-Functionalized Graphene Oxide Strongly Prevents Candida parapsilosis Adhesion and Biofilm Formation." Pharmaceuticals 16, no. 2 (February 11, 2023): 275. http://dx.doi.org/10.3390/ph16020275.
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Candida parapsilosis is the major non-C. albicans species involved in the colonization of central venous catheters, causing bloodstream infections. Biofilm formation on medical devices is considered one of the main causes of healthcare-associated infections and represents a global public health problem. In this context, the development of new nanomaterials that exhibit anti-adhesive and anti-biofilm properties for the coating of medical devices is crucial. In this work, we aimed to characterize the antimicrobial activity of two different coated-surfaces, graphene oxide (GO) and curcumin-graphene oxide (GO/CU) for the first time, against C. parapsilosis. We report the capacity of GO to bind and stabilize CU molecules, realizing a homogenous coated surface. We tested the anti-planktonic activity of GO and GO/CU by growth curve analysis and quantification of Reactive Oxigen Species( ROS) production. Then, we tested the antibiofilm activity by adhesion assay, crystal violet assay, and live and dead assay; moreover, the inhibition of the formation of a mature biofilm was investigated by a viability test and the use of specific dyes for the visualization of the cells and the extra-polymeric substances. Our data report that GO/CU has anti-planktonic, anti-adhesive, and anti-biofilm properties, showing a 72% cell viability reduction and a decrease of 85% in the secretion of extra-cellular substances (EPS) after 72 h of incubation. In conclusion, we show that the GO/CU conjugate is a promising material for the development of medical devices that are refractory to microbial colonization, thus leading to a decrease in the impact of biofilm-related infections.
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Zhang, Fan, Nan Ye, Se Wang, Yue Meng, Hao Fang, Zhuang Wang, and De-Gao Wang. "Dissolved Organic Matter Modulates Algal Oxidative Stress and Membrane System Responses to Binary Mixtures of Nano-Metal-Oxides (nCeO2, nMgO and nFe3O4) and Sulfadiazine." Nanomaterials 9, no. 5 (May 7, 2019): 712. http://dx.doi.org/10.3390/nano9050712.
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Joint biomarker responses, oxidative stress and membrane systems, were determined for nano-metal-oxides (nMeO, i.e., nCeO2, nMgO, and nFe3O4) and sulfadiazine (SDZ) exposed at relevant low concentrations to two freshwater microalgae Scenedesmus obliquus and Chlorella pyrenoidosa. The impacts of dissolved organic matter (DOM) on the joint biomarker responses were also investigated. Results indicated that the presence of SDZ significantly decreased the level of intercellular reactive oxygen species (ROS) in the algal cells exposed to each nMeO. Reduction of cell membrane permeability (CMP) and mitochondrial membrane potential (MMP) in the algal cells was observed when the algae were exposed to the mixture of SDZ and the nMeO. The degree of reduction of the ROS level, CMP, and MMP significantly went down with the addition of DOM to a certain extent. Changes in cellular oxidative stress and membrane function depended on the types of both nMeO and algal species. This contribution provides an insight into the hazard assessment of a mixture consisting of emerging contaminants and DOM, as they can coexist in the aquatic environment.
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Maruthapandi, Moorthy, Arumugam Saravanan, Akanksha Gupta, John H. T. Luong, and Aharon Gedanken. "Antimicrobial Activities of Conducting Polymers and Their Composites." Macromol 2, no. 1 (February 9, 2022): 78–99. http://dx.doi.org/10.3390/macromol2010005.
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Conducting polymers, mainly polyaniline (PANI) and polypyrrole (PPY) with positive charges bind to the negatively charged bacterial membrane to interfere with bacterial activities. After this initial electrostatic adherence, the conducting polymers might partially penetrate the bacterial membrane and interact with other intracellular biomolecules. Conducting polymers can form polymer composites with metal, metal oxides, and nanoscale carbon materials as a new class of antimicrobial agents with enhanced antimicrobial properties. The accumulation of elevated oxygen reactive species (ROS) from composites of polymers-metal nanoparticles has harmful effects and induces cell death. Among such ROS, the hydroxyl radical with one unpaired electron in the structure is most effective as it can oxidize any bacterial biomolecules, leading to cell death. Future endeavors should focus on the combination of conducting polymers and their composites with antibiotics, small peptides, and natural molecules with antimicrobial properties. Such arsenals with low cytotoxicity are expected to eradicate the ESKAPE pathogens: Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.
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Ramirez, Rafael Andres, Alejandro Jimenez, Claudia Patricia Pérez Rodriguez, and Laura Restrepo. "Evaluation of the use of reactive oxygen species (ROS) generated through oxyion® technology in strawberry (Fragaria × ananassa (Duchesne ex Weston) Duchesne ex Rozier cv. Monterrey) storage." Acta Agronómica 67, no. 2 (April 1, 2018): 223–30. http://dx.doi.org/10.15446/acag.v67n2.66580.
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Las especies reactivas de oxigeno (ROS) tienen un papel primordial en los procesos de estrés oxidativos a nivel biológico. En la mayoría de los casos la presencia de dichas especies químicas es indeseable debido al impacto que tienen sobre tejidos y estructuras celulares, sin embargo, sus efectos pueden ser empleados para controlar la incidencia de microorganismos responsables de procesos de deterioro en frutas y hortalizas. En el presente estudio se estudió la viabilidad de compaginar el almacenamiento a baja temperatura con la presencia de especies reactivas de oxigeno generadas empleando la tecnología Oxyion® para el control del proceso de deterioro en fresa (Fragaria X ananassa). Los tratamientos empleados fueron almacenamiento control (4°C± 2°C sin Oxyion®) y almacenamiento ROS (4°C± 2°C con Oxyion®), para dos categorías del producto de acuerdo con el peso y estado de maduración según la NTC 4103 (ICONTEC, 1997). Las variables fueron monitoreadas con puntos de medición en 1, 3, 5, 7, 10 y 15 días después de cosecha en porcentaje de pérdida de masa, sólidos solubles, intensidad respiratoria, acidez, resistencia, color y etileno. Adicionalmente se analizaron los efectos y las interacciones significativas entre variables. Al concluir el estudio, se determinó que la tecnología Oxyion® presentó diferencias estadísticamente significativas en comparación con el control, e indujo a una menor pérdida de peso, mayor resistencia y menor producción exógena de etileno, prolongando la vida útil de la fresa cv. Monterrey en un 40% durante almacenamiento, adicionalmente las pérdidas por acción de microorganismos presentes en la superficie de las fresas se redujeron de forma considerable, generando un precedente positivo en los procesos de almacenamiento y conservación de frutas para Colombia.
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Dallio, Marcello, Mario Masarone, Giuseppe Gerardo Caprio, Rosa Di Sarno, Concetta Tuccillo, Ferdinando Carlo Sasso, Marcello Persico, Carmela Loguercio, and Alessandro Federico. "Endocan Serum Levels in Patients with Non-Alcoholic Fatty Liver Disease with or without Type 2 Diabetes Mellitus: A Pilot Study." Journal of Gastrointestinal and Liver Diseases 26, no. 3 (September 1, 2017): 261–68. http://dx.doi.org/10.15403/jgld.2014.1121.263.dal.
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Background & Aims: Non-alcoholic fatty liver disease (NAFLD) is emerging as an independent cardiovascular risk factor. Recently, Endocan has been studied as an early marker of endothelial dysfunction. Our aim was to evaluate Endocan serum levels in patients with NAFLD with or without type 2 diabetes mellitus.Method: We enrolled 56 patients: 19 with NAFLD and 37 with type 2 diabetes mellitus with or without NAFLD, and compared them to 25 healthy controls. Endocan serum level was measured by using the ELISA EndoMark assay.Results: Endocan level was significantly higher in NAFLD subjects, compared to controls (1.23±1.51 vs 0.68±0.4 ng/mL; p=0.016). It was higher in patients with non-alcoholic fatty liver and non-alcoholic steatohepatitis (NASH) (1.12±1.11, 1.49±2.16 and 0.68±0.4 ng/ml vs controls, respectively), independently from presence of type 2 diabetes mellitus. The increase was more marked in patients with NASH and in those with NAFL versus controls (p=0.001 and p=0.004, respectively), but not statistically different between the two groups (p=0.448). Finally, we found a statistically relevant increase of this marker in diabetic NAFLD patients compared to those non diabetic (1.56±0.81 vs 0.72±0.58 ng/ml; p=0.01).Conclusion: We demonstrated an increased Endocan serum level in NAFLD patients, higher in those with type 2 diabetes mellitus and/or NASH because of an endothelial dysfunction in these pathologies.Abbreviations: BMI: Body Mass Index; CCBS: calcium channel blockers; ED: endothelial dysfunction; ELISA: enzyme-linked immunosorbent assay; ESM-1: Endothelial cell-specific molecule-1; HOMA-IR: Homeostasis Model Assessment Insulin Resistance; ICAM: Intercellular Adhesion Molecule; LFA-1: Lymphocyte Function-Associated Antigen 1; NAFL: non-alcoholic fatty liver; NAFLD: Non-alcoholic fatty liver disease; NAS: non-alcoholic fatty liver disease activity score; NASH: non-alcoholic steatohepatitis; ROS: reactive oxigen species; T2DM: type 2 diabetes mellitus; TNF-alpha: tumor necrosis factor-alpha.
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Xiong, Biao, Shi Chen, Peng Zhu, Meiling Huang, Weijie Gao, Rui Zhu, Jianqiang Qian, et al. "Design, Synthesis, and Biological Evaluation of Novel Thiazolyl Substituted Bis-pyrazole Oxime Derivatives with Potent Antitumor Activities by Selectively Inducing Apoptosis and ROS in Cancer Cells." Medicinal Chemistry 15, no. 7 (October 14, 2019): 743–54. http://dx.doi.org/10.2174/1573406414666180827112724.
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Background: A large number of pyrazole derivatives have different biological activities such as anticancer, antimicrobial, anti-inflammatory, analgesic and antiepileptic activity. Among them, pyrazole oximes have attracted much attention due to their potential pharmacological activities, particularly anticancer activities. Objective: Our goal is to synthesize novel thiazolyl substituted bis-pyrazole oxime derivatives with potent antitumor activities by selectively inducing apoptosis and Reactive Oxygen Species (ROS) accumulation in cancer cells. Methods: Eighteen bis-pyrazole oximes were synthesized by conjugating thiazolyl substituted pyrazoles with pyrazoxime. The target compounds were characterized by 1HNMR, 13C NMR, and HRMS, and screened for their antiproliferative activity against four cancer cells in MTT assay. The most potent compound was examined for its inhibitory effect and ROS accumulation in both cancer cells HCT116 and normal intestinal epithelial cells CCD841. Finally, the most potent compound was further evaluated for its apoptotic induction by flow cytometry analysis and immunoblot analysis of apoptosis-related proteins and DNA damage proteins. Results: Most compounds displayed potent antiproliferative activity against four cancer cell lines in vitro, displaying potencies superior to 5-FU. In particular, the most potent compound 13l selectively inhibited proliferation of colorectal cancer HCT116 cells but not normal colon CCD841 cells. Furthermore, compound 13l also selectively promoted intracellular ROS accumulation in HCT116 which was involved in 13l inhibition of cancer cell proliferation and induction of cell apoptosis. Finally, compound 13l also dose-dependently induced cancer cell apoptosis by regulating apoptotic and DNA damage related proteins expressions. Conclusion: Our synthetic bis-pyrazole oxime derivatives possess potent antitumor activities by selectively inducing apoptosis and ROS accumulation in cancer cells, which may hold great promise as therapeutic agents for the treatment of human cancers.
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Maurea, Nicola, Carmela Coppola, Domenica Rea, Giovanna Piscopo, Gennaro Riccio, Antonio Barbieri, Giuseppe Palma, et al. "Inhibition of cardiomyocytes late INa with ranolazine blunts anthracyclines-cardiotoxicity in experimental models in vitro and in vivo." Journal of Clinical Oncology 30, no. 15_suppl (May 20, 2012): e13539-e13539. http://dx.doi.org/10.1200/jco.2012.30.15_suppl.e13539.
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e13539 Background: Anthracyclines produce a well-known cardiomyopathy through multiple mechanisms, which also include, among many, Ca2+ overload due to reduced SERCA2a activity and inappropriate opening of the RyR2, and impaired myocardial energetics. Anthracyclines generate Reactive Oxigen and Nitrogen Species (ROS and RNS), posing the heart at increased demand for oxygen, thus setting the stage for a metabolic ischemia that also activates late INa, the target of ranolazine (RAN). Here, we aim at assessing whether RAN, diminishing intracellular Ca2+ through its inhibition of late INa, and enhancing myocardial glucose utilization (and/or reverting impairment of glucose utilization caused by chemotherapy) blunts anthracyclines cardiotoxicity. Methods: To assess for toxicity in vitro, rat H9C2 cardiomyoblasts were pretreated with RAN (0.1-1mM) for 72 hours and then treated with doxorubicin (DOX, 0.1 mM) for additional 24 hours. Cells counts were assessed by Trypan exclusion test. To evaluate cardiac function in vivo, fractional shortening (FS) and ejection fraction (EF) were measured by echocardiography in C57BL6 mice, 2-4 mo old, pretreated with RAN (370mg/kg/day, a dose comparable to the one used in humans) per os for 3 days. RAN was then administered for additional 7 days, together with DOX (2.17mg/kg/day ip), according to our well established protocol. Results: After DOX, only 68% of the cells were viable. RAN alone did not affect cell survival, but blunted DOX toxicity, rescuing % cell survival to 87% (p=.01 vs DOX alone). In our in vivo studies, after 7 days with DOX, FS decreased to 50±2%, p=.002 vs 60±1% (sham), and EF to 81±2%, p=0.0001 vs 91±1% (sham). RAN alone did not change FS (59±2%) nor EF (89±1%). Interestingly, in mice treated with RAN and DOX, the reduction in cardiac function was milder: FS was 57±1%, EF was 89±1%, p=0.01 and 0.0009 respectively, vs DOX alone. Conclusions: RAN blunts DOX cardiotoxic effects in 2 different models, in vitro and in vivo. We plan to test RAN as a cardioprotective agent with other antineoplastic cardiotoxic drugs in our experimental models, and to better characterize the cardioprotective mechanisms of RAN in all these settings.
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Dissanayake, Deepamali, Laura A. Achola, Peter Kerns, Dinithi Rathnayake, Junkai He, John Macharia, and Steven L. Suib. "Aerobic oxidative coupling of amines to imines by mesoporous copper aluminum mixed metal oxides via generation of Reactive Oxygen Species (ROS)." Applied Catalysis B: Environmental 249 (July 2019): 32–41. http://dx.doi.org/10.1016/j.apcatb.2019.02.037.
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Nandanwar, Sondavid, Myung Won Lee, Shweta Borkar, Jeong Hyung Cho, Naresh H. Tarte, and Hak Jun Kim. "Synthesis, Characterization, and Anti-Algal Activity of Molybdenum-Doped Metal Oxides." Catalysts 10, no. 7 (July 20, 2020): 805. http://dx.doi.org/10.3390/catal10070805.
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In this study, we attempted to synthesize visible light active nano-sized photocatalysts using metal oxides such as zinc oxide, zirconium oxide, tungsten oxide, and strontium titanium oxide with (MoCl5)2 as a dopant by the simple ball-milling method. Fourier-transform infrared spectroscopy data confirmed the presence of M-O-Mo linkage (M = Zn, Zr, W, and SrTi) in all the molybdenum-doped metal oxides (MoMOs), but only MoZnO inhibited the growth of the bloom-forming Microcystis aeruginosa under visible light in a concentration-dependent manner up to 10 mg/L. Further, structural characterization of MoZnO using FESEM and XRD exhibited the formation of typical hexagonal wurtzite nanocrystals of approximately 4 nm. Hydroxyl radical (·OH), reactive oxygen species (ROS), and lipid peroxidation assays revealed ·OH generated by MoZnO under the visible light seemed to cause peroxidation of the lipid membrane of M. aeruginosa, which led to an upsurge of intracellular ROS and consequently introduced the agglomeration of cyanobacteria. These results demonstrated that nano-sized MoZnO photocatalyst can be easily synthesized in a cost-effective ball-mill method and utilized for biological applications such as the reduction of harmful algal blooms. Further, our study implies that a simple ball-milling method can provide an easy, green, and scalable route for the synthesis of visible light active doped metal oxides.
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Ueno, Yuki, Yoshiyuki Kawamoto, Yamato Nakane, Risa Natsume, Kyoko Miura, Yui Okumura, Takashi Murate, Emi Hattori, and Toshihiko Osawa. "Oxidized Perilla and Linseed Oils Induce Neuronal Apoptosis by Caspase-Dependent and -Independent Pathways." Foods 9, no. 5 (April 26, 2020): 538. http://dx.doi.org/10.3390/foods9050538.
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Alpha-linolenic acid (ALA), a polyunsaturated fatty acid, is involved in bioregulatory functions. In recent years, the health-promoting effects of vegetable-derived edible oils rich in ALA have attracted attention. ALA has a variety of physiological effects such as anti-arteriosclerotic and antiallergic properties, but is prone to oxidation. Therefore, safety concerns exist with regard to adverse effects on humans induced by its oxides. However, the effects on neuronal cells induced by oxidized ALA-rich oils, such as perilla and linseed oils, have not been fully investigated. This information is very important from the viewpoint of food safety. In this study, we investigated the effects of oxidized perilla and linseed oils, which are rich in ALA, on the toxicity of neuronal SH-SY5Y cells. Perilla and linseed oils were significantly oxidized compared with other edible vegetable oils. These oxidized oils induce neuronal cell death and apoptosis via caspase-dependent and -independent pathways through reactive oxygen species (ROS) generation. Furthermore, they suppressed neurite outgrowth. These results suggest that oxidized perilla and linseed oils have the potential to cause neuronal loss and ROS-mediated apoptosis, and thus may affect the onset and progression of neurodegenerative disorders and other diseases.
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Ehsanifar, Mojtaba, Zeinab Montazeri, and Mehravar Rafati. "Exposure to Urban Air Pollution Nanoparticles: Oxidative Stress and Cardiovascular Disease." Journal of Biomedical Research & Environmental Sciences 3, no. 4 (April 2022): 429–35. http://dx.doi.org/10.37871/jbres1461.
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It is estimated that more than two-thirds of air pollution-related deaths are due to cardiovascular causes. Significant studies have now indicated that exposure to urban air pollutants is known to be a source of oxidative stress and inflammation that causes cardiovascular disease. Nitrogen oxides, Particulate Matter (PM) such as coarse particle (PM10, PM <10μm), fine particles (PM2.5, PM <2.5μm) and Ultra-Fine Particles (UFPs or PM0.1, PM <0.1μm,), ozone and transition metals are oxidant potent capable of producing Reactive Oxygen Species (ROS). Although several biological mechanisms are involved in cardiovascular disease, oxidative stress is an important observation in many levels of cardiovascular failure due to exposure to air pollutants. This mini-review cites evidence that oxidative stress is a key pathway for various cardiovascular measures of exposure to air pollution.
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Sugawara, Takeaki, Hideyuki Oguro, and Atsushi Iwama. "TET Family Oncogene Fus Is Essential for the Maintenance of Self-Renewing Hematopoietic Stem Cells." Blood 114, no. 22 (November 20, 2009): 2529. http://dx.doi.org/10.1182/blood.v114.22.2529.2529.
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Abstract Abstract 2529 Poster Board II-506 A Proto-oncogene FUS (fusion derived from malignant liposarcoma), also known as TLS (translocated in liposarcoma), was originally identified in chromosomal translocation of human soft tissue sarcoma. FUS is also known to be fused with an ETS family transcription factor ERG in human myeloid leukemia with t(16;21) which is associated with poor prognosis. Based on its protein structure, DNA- and RNA-binding activity and involvement in many human cancers as the fusion with various transcription factors, FUS is now grouped with EWS and TAFII68 into TET (FET) oncogene family. Multiple functions have been postulated for FUS, including non-coding-RNA-mediated transcriptional repression, posttranscriptional RNA processing and the maintenance of genomic integrity. Fus-deficient (Fus−/−) mice showed a non-cell-autonomous defect in B lymphocyte development, defective B cell activation and increased sensitivity to radiation in previous studies. However, its physiological function in hematopoiesis remains unknown. In this study we performed detailed analyses of Fus−/− hematopoietic stem cells (HSCs). Fus−/− fetal livers at embryonic day 14.5 exhibited a mild reduction in numbers of hematopoietic stem and progenitor cells compared with the wild type. Disruption of Fus, however, did not grossly affect proliferation or differentiation of hematopoietic progenitors. Of note, Fus−/− HSCs had significantly reduced repopulating activity of hematopoiesis in competitive repopulation assays, and did not repopulate hematopoiesis at all in tertiary recipients. Moreover, Fus−/− HSCs were highly sensitive to radiation both in vitro and in vivo and showed a drastic reduction in numbers in recipient mice after sublethal irradiation. All these findings implicate Fus in the maintenance and radioprotection of HSCs. Studies of chromosome stability, telomere length, apoptosis and levels of reactive oxigen species (ROS) appeared not accountable for the apparent defect of Fus−/− HSCs. However, gene expression profiling identified changes in expression of several genes in Fus−/− HSCs, and dysregulated expression of some of these genes might be responsible for the defective function of Fus−/− HSCs. Disclosures: No relevant conflicts of interest to declare.
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Wu, Yun, Mei Wang, Shaojuan Luo, Yunfeng Gu, Dongyang Nie, Zhiyang Xu, Yue Wu, Mindong Chen, and Xinlei Ge. "Comparative Toxic Effects of Manufactured Nanoparticles and Atmospheric Particulate Matter in Human Lung Epithelial Cells." International Journal of Environmental Research and Public Health 18, no. 1 (December 22, 2020): 22. http://dx.doi.org/10.3390/ijerph18010022.
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Although nanoparticles (NPs) have been used as simplified atmospheric particulate matter (PM) models, little experimental evidence is available to support such simulations. In this study, we comparatively assessed the toxic effects of PM and typical NPs (four carbonaceous NPs with different morphologies, metal NPs of Fe, Al, and Ti, as well as SiO2 NPs) on human lung epithelial A549 cells. The EC50 value of PM evaluated by cell viability assay was 148.7 μg/mL, closest to that of SiO2 NPs, between the values of carbonaceous NPs and metal NPs. All particles caused varying degrees of reactive oxygen species (ROS) generation and adenosine triphosphate (ATP) suppression. TiO2 NPs showed similar performance with PM in inducing ROS production (p < 0.05). Small variations between two carbonaceous NPs (graphene oxides and graphenes) and PM were also observed at 50 μg/mL. Similarly, there was no significant difference in ATP inhibition between carbonaceous NPs and PM, while markedly different effects were caused by SiO2 NP and TiO2 NP exposure. Our results indicated that carbonaceous NPs could be served as potential surrogates for urban PM. The identification of PM model may help us further explore the specific roles and mechanisms of various components in PM.
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Johnson, Haden Andrew, Randall Scott Williamson, Mary Marquart, Joel David Bumgardner, Amol V. Janorkar, and Michael David Roach. "Photocatalytic activity and antibacterial efficacy of UVA-treated titanium oxides." Journal of Biomaterials Applications 35, no. 4-5 (July 19, 2020): 500–514. http://dx.doi.org/10.1177/0885328220942669.
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Studies have shown ultraviolet-A (UVA) irradiation of crystalline titanium oxides leads to the production of reactive oxygen species (ROS) via a photocatalytic process. The ROS exhibit antimicrobial properties that may be of benefit in preventing bacterial attachment to implant devices. Recent studies have suggested a potential benefit of mixed anatase and rutile oxides and dopants on the photocatalytic properties of titanium oxides. The goal of this work was to compare the photocatalytic activity of different anodized commercially pure titanium grade 4 (CPTi4) surfaces. CPTi4 specimens were anodized in three mixed-acid electrolytes to create crystalline oxide surfaces that were either primarily anatase, primarily rutile, or a combination of anatase and rutile. Additionally, the primarily anatase and combination oxides incorporated some phosphorous from the phosphoric acid component in the electrolyte. The photocatalytic activity of the anodized specimens was measured using both methylene blue (MB) degradation assay and comparing the attachment of S. aureus under irradiation with UVA light of differing intensities (1 mW/cm2, 8 mW/cm2, and 23 mW/cm2). Primarily rutile oxides exhibited significantly higher levels of MB degradation after exposure to 1 mW/cm2 UVA lights. Primarily rutile specimens also had the largest reduction in bacterial attachment followed by the mixed phase specimens and the primarily anatase specimens at 1 mW/cm2 UVA lights. Phosphorous-doped, mixed phase oxides exhibited an accelerated MB degradation response during exposure to 8 mW/cm2 and 23 mW/cm2 UVA lights. All anodized and unanodized CPTi4 groups revealed similar S. aureus attachment at the two higher UVA intensities. Although MB degradation assay and the bacteria attachment assay both confirmed photocatalytic activity of the oxides formed in this study, the results of the MB degradation assay did not accurately predict the oxides performance against S. aureus.
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Gharpure, Saee, and Balaprasad Ankamwar. "Synthesis and Antimicrobial Properties of Zinc Oxide Nanoparticles." Journal of Nanoscience and Nanotechnology 20, no. 10 (October 1, 2020): 5977–96. http://dx.doi.org/10.1166/jnn.2020.18707.
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With increase in incidence of multidrug resistant pathogens, there is a demand to adapt newer approaches in order to combat these diseases as traditional therapy is insufficient for their treatment. Use of nanotechnology provides a promising alternative as antimicrobial agents as against traditional antibiotics. Metal oxides have been exploited for a long times for their antimicrobial properties. Zinc oxide nanoparticles (ZnO NPs) are preferred over other metal oxide nanoparticles because of their bio-compatible nature and excellent antibacterial potentials. The basic mechanism of bactericidal nature of ZnO nanoparticles includes physical contact between ZnO nanoparticles and the bacterial cell wall, generation of reactive oxygen species (ROS) as well as free radicals and release of Zn2+ ions. This review focuses on different synthesis methods of ZnO nanoparticles, various analytical techniques frequently used for testing antibacterial properties, mechanism explaining antibacterial nature of ZnO nanoparticles as well as different factors affecting the antibacterial properties.
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Lodovici, Maura, and Elisabetta Bigagli. "Oxidative Stress and Air Pollution Exposure." Journal of Toxicology 2011 (2011): 1–9. http://dx.doi.org/10.1155/2011/487074.
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Air pollution is associated with increased cardiovascular and pulmonary morbidity and mortality. The mechanisms of air pollution-induced health effects involve oxidative stress and inflammation. As a matter of fact, particulate matter (PM), especially fine (PM2.5, PM < 2.5 μm) and ultrafine (PM0.1, PM < 0.1 μm) particles, ozone, nitrogen oxides, and transition metals, are potent oxidants or able to generate reactive oxygen species (ROS). Oxidative stress can trigger redox-sensitive pathways that lead to different biological processes such as inflammation and cell death. However, it does appear that the susceptibility of target organ to oxidative injury also depends upon its ability to upregulate protective scavenging systems. As vehicular traffic is known to importantly contribute to PM exposure, its intensity and quality must be strongly relevant determinants of the qualitative characteristics of PM spread in the atmosphere. Change in the composition of this PM is likely to modify its health impact.
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Cahue, Kiana A., Abigail L. Dudek, Mantas M. Miliauskas, Tatiana R. Cahue, Amy Mlynarski, and Jason J. Keleher. "Design of “Low Stress” Post-CMP Cleaning Processes for Advanced Technology Nodes." ECS Meeting Abstracts MA2022-01, no. 28 (July 7, 2022): 1242. http://dx.doi.org/10.1149/ma2022-01281242mtgabs.
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As integrated circuit and logic device feature sizes approach the 3-nm node, limiting induced defectivity during Chemical Mechanical Planarization (CMP) process (polishing and substrate cleaning) is of utmost importance. The CMP process can cause various defects, and they can be classified as mechanical (i.e., scratching), chemical (i.e., corrosion), or physiochemical (i.e., adsorbed contaminants) according to the mechanism of formation. Traditionally, a contact cleaning method involving a poly-vinyl alcohol (PVA) brush is used to transfer cleaning chemistry to the substrate of interest as well as provide the necessary mechanical energy for defect removal. While this process is effective in contaminant removal its reliance on shear forces can induce secondary defect modes, such as scratching. To minimize the aforementioned induced defectivity during contact p-CMP processes, the implementation of non-contact modalities has become of the utmost importance. This work will focus on the rationale design of p-CMP cleaning systems for emerging materials such as SiC, GaN, carbon-doped oxides, and metals. More specifically, “OVER”-cutting and “soft” cleaning processes that balance the modulation of surface reaction kinetics (chemical and adsorption) with advanced low shear force environment will be evaluated. For example, employing supramolecular cleaning chemistries coupled with reactive oxygen species (ROS) generating complexes under megasonic action were evaluated for effective SiC cleaning. Results from a second order kinetic model indicate that processing conditions (i.e., time and power), “soft” cleaning chemistry structure (i.e., shape and charge), and the generation of ROS all play a critical role in cleaning efficacy under low stress conditions in the megasonic field. Utilizing a suite of dynamic analytical techniques (i.e., atomic force microscopy, quartz crystal microbalance, contact angle, zeta potential, and electrochemical analysis, shear force analysis) a correlation between interfacial reaction mechanisms and effective p-CMP cleaning will be presented.
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Cruzi, Trypanosoma, Infection Grazielle Alves Ribeiro, Brenda Silva Rosa-da-Luz, and Leda Quercia Vieira. "The Role of Reactive Oxigen Species During." Free Radical Biology and Medicine 53 (November 2012): S79. http://dx.doi.org/10.1016/j.freeradbiomed.2012.10.236.
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Ehsanifar, Mojtaba, Banihashemian SS, and Masoud Ehsanifar. "Exposure to Air Pollution Nanoparticles: Oxidative Stress and Neuroinflammation." Journal of Biomedical Research & Environmental Sciences 2, no. 10 (October 2021): 964–76. http://dx.doi.org/10.37871/jbres1339.
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Urban air pollutants exposure is known as a source of neuroinflammation and oxidative stress that causes the Central Nervous System (CNS) and neuropathology disease. Transition metals, Particulate Matter (PM), including PM 2.5 (PM <2.5 μm) and PM 0.1 (PM <0.1μm), nitrogen oxides and ozone are of potent or oxidant capable of producing Reactive Oxygen Species (ROS). Redox-sensitive pathways can be caused by oxidative stress, leading to various biological processes, including inflammation and cell death. The incidence of Alzheimer's Disease (AD) and Parkinson's Disease (PD) and stroke are associated with exposure to air pollution. Some recent findings suggest that urban air pollutants reach the brain in addition to pulmonary and cardiovascular diseases and affect the CNS health too. While the underlying CNS pathology mechanisms induced air pollutants exposure are not well understood, recent studies show that changes in Blood Brain Barrier (BBB) and microglial activation are key components. In this work, we reviewed the new evidence of the mechanisms by which ambient air pollution reach the brain and activate innate immune response as a source of oxidative stress and neuroinflammatory factors.
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Oakes, M., R. J. Weber, B. Lai, A. Russell, and E. D. Ingall. "Characterization of iron speciation in single particles using XANES spectroscopy and micro X-ray fluorescence measurements: insight into factors controlling iron solubility." Atmospheric Chemistry and Physics Discussions 11, no. 8 (August 11, 2011): 22771–99. http://dx.doi.org/10.5194/acpd-11-22771-2011.
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Abstract. Soluble iron in fine atmospheric particles has been identified as a public health concern by participating in reactions that generate reactive oxygen species (ROS). The mineralogy and oxidation state (speciation) of iron have been shown to influence solubility. In this study, iron speciation was determined in single particles at urban and rural sites in Georgia USA using X-ray Absorption Near-Edge Structure (XANES) spectroscopy and microscopic X-ray fluorescence. Iron solubility of these samples was measured using spectrophotometry. These measurements (XANES and spectrophotometry) were combined to investigate the relationship between iron speciation and solubility in ambient aerosols. XANES measurements indicate that iron in the single particles was present as a mixture of Fe(II) and Fe(III), with Fe(II) content generally between 5 and 35 % (mean: ~25 %). XANES and elemental analyses indicate that a majority (74 %) of Fe particles are best characterized as Al-substituted Fe-oxides, with a Fe/Al molar ratio of 4.9. The next most abundant group of particles (12 %) was Fe-aluminosilicates, with Si/Al molar ratio of 1.4. No correlation was found between fractional iron solubility (soluble iron/total iron) and the abundance of Al-substituted Fe-oxides and Fe-aluminosilicates present in single particles at any of the sites during different seasons, suggesting solubility largely depended on factors other than differences in major iron phases.
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Naskar, Atanu, and Kwang-sun Kim. "Photo-Stimuli-Responsive CuS Nanomaterials as Cutting-Edge Platform Materials for Antibacterial Applications." Pharmaceutics 14, no. 11 (October 30, 2022): 2343. http://dx.doi.org/10.3390/pharmaceutics14112343.
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Photo-stimuli-responsive therapeutic nanomaterials have gained widespread attention as frontline materials for biomedical applications. The photoactivation strategies are classified as single-modality (based on either reactive oxygen species (ROS)-based photodynamic therapy (PDT), hyperthermia-based photothermal therapy (PTT)), or dual-modality (which combines PDT and PTT). Due to its minimal invasiveness, phototherapy has been extensively applied as an efficient therapeutic platform for many diseases, including skin cancers. However, extensive implementation of phototherapy to address the emergence of multidrug-resistant (MDR) bacterial infections remains challenging. This review focuses on copper sulfide (CuS) nanomaterials as efficient and cost-effective PDT and PTT therapeutic nanomaterials with antibacterial activity. The features and merits of CuS nanomaterials as therapeutics are compared to those of other nanomaterials. Control of the dimensions and morphological complexity of CuS nanomaterials through judicious synthesis is then introduced. Both the in vitro antibacterial activity and the in vivo therapeutic effect of CuS nanomaterials and derivative nanocomposites composed of 2D nanomaterials, polymers, metals, metal oxides, and proteins are described in detail. Finally, the perspective of photo-stimuli-responsive CuS nanomaterials for future clinical antibacterial applications is highlighted. This review illustrates that CuS nanomaterials are highly effective, low-toxic, and environmentally friendly antibacterial agents or platform nanomaterials for combatting MDR bacterial infections.
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Lambert, Brett, Annalese Semmler, Cristina Beer, and Joanne Voisey. "Pyrroles as a Potential Biomarker for Oxidative Stress Disorders." International Journal of Molecular Sciences 24, no. 3 (February 1, 2023): 2712. http://dx.doi.org/10.3390/ijms24032712.
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Redox imbalance or oxidative stress that results from both environmental and genetic factors is observed in patients with schizophrenia. Therefore, identifying markers of oxidative stress in the early stages of psychosis and using antioxidant treatments as an adjuvant to antipsychotics has important implications. The reaction of p-N,N-dimethylaminobenzaldehyde (DMAB) with pyrrole moieties has been well studied for well over a century for use as a marker of oxidative stress dysregulation. Throughout this time, pyrroles have been investigated with varying veracity in urine extracts to identify elevated levels in patients diagnosed with schizophrenia. Since the 1960’s, various claims have been made with respect to what causes the colour change when DMAB is added to urine extracts. Whilst the substances from this reaction have not been fully elucidated, an objective look at most studies indicates that urobilinogen is likely to be one them. Urobilinogen has also been identified as a major interferent in our results. Both pyrroles and urobilinogen condense the DMAB reaction system (form condensation products) and are quite different. The urobilinogen detected in urine forms when gut microflora chemically reduces the bilirubin content of bile acids. In comparison, evidence suggests that the pyrrole fraction originates from the fragmentation of regulatory haem by reactive oxygen species (ROS) such as hydrogen peroxide and super and nitrous oxides. Clinical studies in our laboratories have established that pyrroles as a urine biomarker have specificity in detecting schizophrenia; however, caution must be applied as the readings are subject to interference by other DMAB active compounds that are present, such as urobilinogen. This review highlights the initial chemistry in isolating pyrroles and provides recommendations for standardised laboratory testing to ensure pyrroles are correctly measured and distinguished from other by-products.
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Zhu, Yingjie, Dong Li, Tarun Belwal, Li Li, Hangjun Chen, Tingqiao Xu, and Zisheng Luo. "Effect of Nano-SiOx/Chitosan Complex Coating on the Physicochemical Characteristics and Preservation Performance of Green Tomato." Molecules 24, no. 24 (December 12, 2019): 4552. http://dx.doi.org/10.3390/molecules24244552.
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A novel nano-silicon oxides (SiOx)/chitosan complex film was prepared using ultrasonic assistant in the process of dissolving chitosan and silicon oxides (SiOx), and characterized by transmission electron microscopy. Its effect on quality preservation of tomatoes (Solanum lycopersicum L. cv. Zheza 205) was investigated under ambient temperature. The results revealed that the nano-SiOx/chitosan complex (NSCC) film retarded weight loss and softness, delayed the titratable acids and total soluble solids loss, and thus markedly extended shelf life of green tomatoes. The antimicrobial activity of tomatoes coated with NSCC film was also recorded higher compared to chitosan (Ch) films and control. In addition, the NSCC film-coated tomatoes prevent the increase of malondialdehyde content and total polyphenol content. Moreover, the peroxidase activity, phenylalanine ammonia-lyase activity, and polyphenoloxidase activity of tomatoes coated with NSCC film were found lower than that in other treatments. These data indicated that the beneficial effects of nano-SiOx/chitosan complex coating on postharvest quality were possibly associated with the lower rate of O2/CO2 transmission coefficient, limiting food-borne pathogenic bacterial growth, higher antioxidant activities, and also higher reactive oxygen species (ROS) scavenging and anti-browning activities of related enzymes in the tomatoes. Further, the results of the study could be used to successfully develop a novel nano-SiOx/chitosan complex film for improving the postharvested quality of tomatoes and thus effectively utilized by the food packaging industry.
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Mu, Zi-Qi, Da-Mao Xu, and Rong-Bing Fu. "Insight into the Adsorption Behaviors of Antimony onto Soils Using Multidisciplinary Characterization." International Journal of Environmental Research and Public Health 19, no. 7 (April 2, 2022): 4254. http://dx.doi.org/10.3390/ijerph19074254.
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Antimony (Sb) pollution in soils is an important environmental problem, and it is imperative to investigate the migration and transformation behavior of Sb in soils. The adsorption behaviors and interaction mechanisms of Sb in soils were studied using integrated characterization techniques and the batch equilibrium method. The results indicated that the adsorption kinetics and isotherms of Sb onto soils were well fitted by the first-order kinetic, Langmuir, and Freundlich models, respectively, while the maximum adsorbed amounts of Sb (III) in soil 1 and soil 2 were 1314.46 mg/kg and 1359.25 mg/kg, respectively, and those of Sb (V) in soil 1 and soil 2 were 415.65 mg/kg and 535.97 mg/kg, respectively. In addition, pH ranging from 4 to 10 had little effect on the adsorption behavior of Sb. Moreover, it was found that Sb was mainly present in the residue fractions, indicating that Sb had high geochemical stability in soils. SEM analysis indicated that the distribution positions of Sb were highly coincident with Ca, which was mainly due to the existence of calcium oxides, such as calcium carbonate and calcium hydroxide, that affected Sb adsorption, and further resulted in Sb and Ca bearing co-precipitation. XPS analysis revealed the valence state transformation of Sb (III) and Sb (V), suggesting that Fe/Mn oxides and reactive oxygen species (ROS) served as oxidant or reductant to promote the occurrence of the Sb redox reaction. Sb was mobile and leachable in soils and posed a significant threat to surface soils, organisms, and groundwater. This work provides a fundamental understanding of Sb adsorption onto soils, as well as a theoretical guide for studies on the adsorption and migration behavior of Sb in soils.
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Zorov, Dmitry B., Charles R. Filburn, Lars-Oliver Klotz, Jay L. Zweier, and Steven J. Sollott. "Reactive Oxygen Species (Ros-Induced) Ros Release." Journal of Experimental Medicine 192, no. 7 (October 2, 2000): 1001–14. http://dx.doi.org/10.1084/jem.192.7.1001.
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We sought to understand the relationship between reactive oxygen species (ROS) and the mitochondrial permeability transition (MPT) in cardiac myocytes based on the observation of increased ROS production at sites of spontaneously deenergized mitochondria. We devised a new model enabling incremental ROS accumulation in individual mitochondria in isolated cardiac myocytes via photoactivation of tetramethylrhodamine derivatives, which also served to report the mitochondrial transmembrane potential, ΔΨ. This ROS accumulation reproducibly triggered abrupt (and sometimes reversible) mitochondrial depolarization. This phenomenon was ascribed to MPT induction because (a) bongkrekic acid prevented it and (b) mitochondria became permeable for calcein (∼620 daltons) concurrently with depolarization. These photodynamically produced “triggering” ROS caused the MPT induction, as the ROS scavenger Trolox prevented it. The time required for triggering ROS to induce the MPT was dependent on intrinsic cellular ROS-scavenging redox mechanisms, particularly glutathione. MPT induction caused by triggering ROS coincided with a burst of mitochondrial ROS generation, as measured by dichlorofluorescein fluorescence, which we have termed mitochondrial “ROS-induced ROS release” (RIRR). This MPT induction/RIRR phenomenon in cardiac myocytes often occurred synchronously and reversibly among long chains of adjacent mitochondria demonstrating apparent cooperativity. The observed link between MPT and RIRR could be a fundamental phenomenon in mitochondrial and cell biology.
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Tauffenberger, Arnaud, and Pierre J. Magistretti. "Reactive Oxygen Species: Beyond Their Reactive Behavior." Neurochemical Research 46, no. 1 (January 2021): 77–87. http://dx.doi.org/10.1007/s11064-020-03208-7.
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AbstractCellular homeostasis plays a critical role in how an organism will develop and age. Disruption of this fragile equilibrium is often associated with health degradation and ultimately, death. Reactive oxygen species (ROS) have been closely associated with health decline and neurological disorders, such as Alzheimer’s disease or Parkinson’s disease. ROS were first identified as by-products of the cellular activity, mainly mitochondrial respiration, and their high reactivity is linked to a disruption of macromolecules such as proteins, lipids and DNA. More recent research suggests more complex function of ROS, reaching far beyond the cellular dysfunction. ROS are active actors in most of the signaling cascades involved in cell development, proliferation and survival, constituting important second messengers. In the brain, their impact on neurons and astrocytes has been associated with synaptic plasticity and neuron survival. This review provides an overview of ROS function in cell signaling in the context of aging and degeneration in the brain and guarding the fragile balance between health and disease.
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Cui, X. M., Y. K. Zhang, X. B. Wu, and C. S. Liu. "The investigation of the alleviated effect of copper toxicity by exogenous nitric oxide in tomato plants." Plant, Soil and Environment 56, No. 6 (June 3, 2010): 274–81. http://dx.doi.org/10.17221/98/2009-pse.
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As a bioactive signal, nitric oxide (NO) is involved in multiple plant physiological responses, especially under some abiotic stress. Here, we investigated the effects of exogenous nitric oxide on both the reactive oxygen species (ROS) scavenging metabolism and regulating functions of plasma membrane and tonoplast in tomato plants treated with 50µM CuCl<sub>2</sub>. Copper stress induced significant accumulation of H<sub>2</sub>O<sub>2</sub>, led to serious lipid peroxidation, and finally markedly decreased shoot height and fresh weight of tomato plants. The application of 100µM sodium nitroprusside (SNP – NO donor) promoted some antioxidant enzymes, reduced accumulation of H<sub>2</sub>O<sub>2</sub>, and adjusted the activity of H<sup>+</sup>-ATPase and H<sup>+</sup>-PPase in plasma membrane or tonoplast, and significantly alleviated the growth inhibition induced by copper toxicity. On the other hand, the application of sodium ferrocyanide (an analog of SNP) and sodium nitrate or nitrite (the decomposition product of NO or its donor SNP) which did not release NO, did not show the effects of SNP. Furthermore, the effects of SNP were reverted by addition of hemoglobin (an NO scavenger). Therefore, these results indicated that exogenous NO could effectively assuage copper toxicity by physiological and biochemical response so as to maintain normal growth.
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Jhanani, Gopalraaj, Manikantan Pappuswamy, Arun Meyyazhagan, Balamuralikrishnan Balasubramanian, and Vijaya Anand Arumugam. "Toxic Effects of Nanoparticles on Fish Embryos." Research Journal of Biotechnology 16, no. 12 (November 25, 2021): 140–49. http://dx.doi.org/10.25303/1612rjbt140149.
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Nanoparticles are used widely in the in-drug delivery, diagnostics, cosmetics, paints, electronics, fabrics, solar cells, medicines etc. Their wide application is due to their special properties which include minute size, high reaction rate, increased surface area and quantum effect. Despite their multiple applications, nanoparticles have harmful effects too due to their improper disposal causing their entry into the aquatic environment greatly threatening the ecological security as well as our health. Zebra fishes (Danio rerio) are used more commonly for the evaluation of toxicity and are considered a promising animal model. Studies on Salmon and Labeo rohita have also been used for toxicity evaluation. Nanoparticles affect the embryo more easily than the adult since the embryo are more sensitive. Hence it becomes important for us to study the effect of the nanoparticles on the embryo of the fishes. These nanoparticles have the ability to cross the chorion layer and affect the developing embryo. Since the fishes are a part of the food chain, when these organisms get affected they will eventually harm the humans too. This review focuses on the effect of metal nanoparticles (NPs) like gold(Au), silver(Ag), copper(Cu), platinum and metal oxides nanoparticles like titanium dioxide, aluminium oxide, copper oxide, nickel oxide zinc oxide on the embryonic development of fish embryos. When compared to the other nanoparticles (NPs) like silver, copper and platinum, it has been observed that the gold nanoparticles (Au NPs) showed no toxicity to embryos of zebrafish though few studies contradict this. Aluminium nanoparticles showed no toxicity and role of reactive oxygen species (ROS) in enhancing the toxicity of nanoparticles have also been discussed.
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Pietrofesa, Ralph A., Kyewon Park, Om P. Mishra, Darrah Johnson-McDaniel, Jacob W. Myerson, Vladimir V. Shuvaev, Evguenia Arguiri, et al. "Copper Oxide Nanoparticle-Induced Acute Inflammatory Response and Injury in Murine Lung Is Ameliorated by Synthetic Secoisolariciresinol Diglucoside (LGM2605)." International Journal of Molecular Sciences 22, no. 17 (August 31, 2021): 9477. http://dx.doi.org/10.3390/ijms22179477.
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Metal-oxide nanoparticles (MO-NPs), such as the highly bioreactive copper-based nanoparticles (CuO-NPs), are widely used in manufacturing of hundreds of commercial products. Epidemiological studies correlated levels of nanoparticles in ambient air with a significant increase in lung disease. CuO-NPs, specifically, were among the most potent in a set of metal-oxides and carbons studied in parallel regarding DNA damage and cytotoxicity. Despite advances in nanotoxicology research and the characterization of their toxicity, the exact mechanism(s) of toxicity are yet to be defined. We identified chlorination toxicity as a damaging consequence of inflammation and myeloperoxidase (MPO) activation, resulting in macromolecular damage and cell damage/death. We hypothesized that the inhalation of CuO-NPs elicits an inflammatory response resulting in chlorination damage in cells and lung tissues. We further tested the protective action of LGM2605, a synthetic small molecule with known scavenging properties for reactive oxygen species (ROS), but most importantly, for active chlorine species (ACS) and an inhibitor of MPO. CuO-NPs (15 µg/bolus) were instilled intranasally in mice and the kinetics of the inflammatory response in lungs was evaluated 1, 3, and 7 days later. Evaluation of the protective action of LGM2605 was performed at 24 h post-challenge, which was selected as the peak acute inflammatory response to CuO-NP. LGM2605 was given daily via gavage to mice starting 2 days prior to the time of the insult (100 mg/kg). CuO-NPs induced a significant inflammatory influx, inflammasome-relevant cytokine release, and chlorination damage in mouse lungs, which was mitigated by the action of LGM2605. Preventive action of LGM2605 ameliorated the adverse effects of CuO-NP in lung.
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Bondy, S. C., S. X. Guo-Ross, and A. T. Truong. "Potentiation of metal induced reactive oxigen species formation by β-amyloid." Toxicology Letters 95 (July 1998): 59. http://dx.doi.org/10.1016/s0378-4274(98)80234-8.
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Wang, Zhenyu, Xiaoxiao He, Shiyue Chen, Chengdian He, Teng Wang, and Xiang Mao. "Recent Advances in Metal-Based Magnetic Composites as High-Efficiency Candidates for Ultrasound-Assisted Effects in Cancer Therapy." International Journal of Molecular Sciences 22, no. 19 (September 28, 2021): 10461. http://dx.doi.org/10.3390/ijms221910461.
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Metal-based magnetic materials have been used in different fields due to their particular physical or chemical properties. The original magnetic properties can be influenced by the composition of constituent metals. As utilized in different application fields, such as imaging monitoring, thermal treatment, and combined integration in cancer therapies, fabricated metal-based magnetic materials can be doped with target metal elements in research. Furthermore, there is one possible new trend in human activities and basic cancer treatment. As has appeared in characterizations such as magnetic resonance, catalytic performance, thermal efficiency, etc., structural information about the real morphology, size distribution, and composition play important roles in its further applications. In cancer studies, metal-based magnetic materials are considered one appropriate material because of their ability to penetrate biological tissues, interact with cellular components, and induce noxious effects. The disruptions of cytoskeletons, membranes, and the generation of reactive oxygen species (ROS) further influence the efficiency of metal-based magnetic materials in related applications. While combining with cancer cells, these magnetic materials are not only applied in imaging monitoring focus areas but also could give the exact area information in the cure process while integrating ultrasound treatment. Here, we provide an overview of metal-based magnetic materials of various types and then their real applications in the magnetic resonance imaging (MRI) field and cancer cell treatments. We will demonstrate advancements in using ultrasound fields co-worked with MRI or ROS approaches. Besides iron oxides, there is a super-family of heterogeneous magnetic materials used as magnetic agents, imaging materials, catalytic candidates in cell signaling and tissue imaging, and the expression of cancer cells and their high sensitivity to chemical, thermal, and mechanical stimuli. On the other hand, the interactions between magnetic candidates and cancer tissues may be used in drug delivery systems. The materials’ surface structure characteristics are introduced as drug loading substrates as much as possible. We emphasize that further research is required to fully characterize the mechanisms of underlying ultrasounds induced together, and their appropriate relevance for materials toxicology and biomedical applications.
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DeLeon, Eric R., Yan Gao, Evelyn Huang, Maaz Arif, Nitin Arora, Alexander Divietro, Shivali Patel, and Kenneth R. Olson. "A case of mistaken identity: are reactive oxygen species actually reactive sulfide species?" American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 310, no. 7 (April 1, 2016): R549—R560. http://dx.doi.org/10.1152/ajpregu.00455.2015.
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Stepwise one-electron reduction of oxygen to water produces reactive oxygen species (ROS) that are chemically and biochemically similar to reactive sulfide species (RSS) derived from one-electron oxidations of hydrogen sulfide to elemental sulfur. Both ROS and RSS are endogenously generated and signal via protein thiols. Given the similarities between ROS and RSS, we wondered whether extant methods for measuring the former would also detect the latter. Here, we compared ROS to RSS sensitivity of five common ROS methods: redox-sensitive green fluorescent protein (roGFP), 2′, 7′-dihydrodichlorofluorescein, MitoSox Red, Amplex Red, and amperometric electrodes. All methods detected RSS and were as, or more, sensitive to RSS than to ROS. roGFP, arguably the “gold standard” for ROS measurement, was more than 200-fold more sensitive to the mixed polysulfide H2Sn ( n = 1–8) than to H2O2. These findings suggest that RSS may be far more prevalent in intracellular signaling than previously appreciated and that the contribution of ROS may be overestimated. This conclusion is further supported by the observation that estimated daily sulfur metabolism and ROS production are approximately equal and the fact that both RSS and antioxidant mechanisms have been present since the origin of life, nearly 4 billion years ago, long before the rise in environmental oxygen 600 million years ago. Although ROS are assumed to be the most biologically relevant oxidants, our results question this paradigm. We also anticipate our findings will direct attention toward development of novel and clinically relevant anti-(RSS)-oxidants.
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Brown, G. C., and V. Borutaite. "Interactions between nitric oxide, oxygen, reactive oxygen species and reactive nitrogen species." Biochemical Society Transactions 34, no. 5 (October 1, 2006): 953–56. http://dx.doi.org/10.1042/bst0340953.
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ROS (reactive oxygen species) and RNS (reactive nitrogen species) are central to the innate immunity that protects us from infection, but also contribute to degenerative diseases and possibly aging. However, ROS and RNS are increasingly recognized to contribute to physiological signalling. This review briefly describes the main interactions between ROS and RNS and shows how their origins, chemistry, metabolism and biological actions are intimately linked.
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Lettieri, Stefano, Michele Pavone, Ambra Fioravanti, Luigi Santamaria Amato, and Pasqualino Maddalena. "Charge Carrier Processes and Optical Properties in TiO2 and TiO2-Based Heterojunction Photocatalysts: A Review." Materials 14, no. 7 (March 27, 2021): 1645. http://dx.doi.org/10.3390/ma14071645.
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Photocatalysis based technologies have a key role in addressing important challenges of the ecological transition, such as environment remediation and conversion of renewable energies. Photocatalysts can in fact be used in hydrogen (H2) production (e.g., via water splitting or photo-reforming of organic substrates), CO2 reduction, pollution mitigation and water or air remediation via oxidation (photodegradation) of pollutants. Titanium dioxide (TiO2) is a “benchmark” photocatalyst, thanks to many favorable characteristics. We here review the basic knowledge on the charge carrier processes that define the optical and photophysical properties of intrinsic TiO2. We describe the main characteristics and advantages of TiO2 as photocatalyst, followed by a summary of historical facts about its application. Next, the dynamics of photogenerated electrons and holes is reviewed, including energy levels and trapping states, charge separation and charge recombination. A section on optical absorption and optical properties follows, including a discussion on TiO2 photoluminescence and on the effect of molecular oxygen (O2) on radiative recombination. We next summarize the elementary photocatalytic processes in aqueous solution, including the photogeneration of reactive oxygen species (ROS) and the hydrogen evolution reaction. We pinpoint the TiO2 limitations and possible ways to overcome them by discussing some of the “hottest” research trends toward solar hydrogen production, which are classified in two categories: (1) approaches based on the use of engineered TiO2 without any cocatalysts. Discussed topics are highly-reduced “black TiO2”, grey and colored TiO2, surface-engineered anatase nanocrystals; (2) strategies based on heterojunction photocatalysts, where TiO2 is electronically coupled with a different material acting as cocatalyst or as sensitizer. Examples discussed include TiO2 composites or heterostructures with metals (e.g., Pt-TiO2, Au-TiO2), with other metal oxides (e.g., Cu2O, NiO, etc.), direct Z-scheme heterojunctions with g-C3N4 (graphitic carbon nitride) and dye-sensitized TiO2.
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Oakes, M., R. J. Weber, B. Lai, A. Russell, and E. D. Ingall. "Characterization of iron speciation in urban and rural single particles using XANES spectroscopy and micro X-ray fluorescence measurements: investigating the relationship between speciation and fractional iron solubility." Atmospheric Chemistry and Physics 12, no. 2 (January 16, 2012): 745–56. http://dx.doi.org/10.5194/acp-12-745-2012.
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Abstract. Soluble iron in fine atmospheric particles has been identified as a public health concern by participating in reactions that generate reactive oxygen species (ROS). The mineralogy and oxidation state (speciation) of iron have been shown to influence fractional iron solubility (soluble iron/total iron). In this study, iron speciation was determined in single particles at urban and rural sites in Georgia USA using synchrotron-based techniques, such as X-ray Absorption Near-Edge Structure (XANES) spectroscopy and microscopic X-ray fluorescence measurements. Soluble and total iron content (soluble + insoluble iron) of these samples was measured using spectrophotometry and synchrotron-based techniques, respectively. These bulk measurements were combined with synchrotron-based measurements to investigate the relationship between iron speciation and fractional iron solubility in ambient aerosols. XANES measurements indicate that iron in the single particles was present as a mixture of Fe(II) and Fe(III), with Fe(II) content generally between 5 and 35% (mean: ~25%). XANES and elemental analyses (e.g. elemental molar ratios of single particles based on microscopic X-ray fluorescence measurements) indicate that a majority (74%) of iron-containing particles are best characterized as Al-substituted Fe-oxides, with a Fe/Al molar ratio of 4.9. The next most abundant group of particles (12%) was Fe-aluminosilicates, with Si/Al molar ratio of 1.4. No correlation was found between fractional iron solubility (soluble iron/total iron) and the abundance of Al-substituted Fe-oxides and Fe-aluminosilicates present in single particles at any of the sites during different seasons, suggesting solubility largely depended on factors other than differences in major iron phases.
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Zorov, Dmitry B., Magdalena Juhaszova, and Steven J. Sollott. "Mitochondrial Reactive Oxygen Species (ROS) and ROS-Induced ROS Release." Physiological Reviews 94, no. 3 (July 2014): 909–50. http://dx.doi.org/10.1152/physrev.00026.2013.
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Byproducts of normal mitochondrial metabolism and homeostasis include the buildup of potentially damaging levels of reactive oxygen species (ROS), Ca2+, etc., which must be normalized. Evidence suggests that brief mitochondrial permeability transition pore (mPTP) openings play an important physiological role maintaining healthy mitochondria homeostasis. Adaptive and maladaptive responses to redox stress may involve mitochondrial channels such as mPTP and inner membrane anion channel (IMAC). Their activation causes intra- and intermitochondrial redox-environment changes leading to ROS release. This regenerative cycle of mitochondrial ROS formation and release was named ROS-induced ROS release (RIRR). Brief, reversible mPTP opening-associated ROS release apparently constitutes an adaptive housekeeping function by the timely release from mitochondria of accumulated potentially toxic levels of ROS (and Ca2+). At higher ROS levels, longer mPTP openings may release a ROS burst leading to destruction of mitochondria, and if propagated from mitochondrion to mitochondrion, of the cell itself. The destructive function of RIRR may serve a physiological role by removal of unwanted cells or damaged mitochondria, or cause the pathological elimination of vital and essential mitochondria and cells. The adaptive release of sufficient ROS into the vicinity of mitochondria may also activate local pools of redox-sensitive enzymes involved in protective signaling pathways that limit ischemic damage to mitochondria and cells in that area. Maladaptive mPTP- or IMAC-related RIRR may also be playing a role in aging. Because the mechanism of mitochondrial RIRR highlights the central role of mitochondria-formed ROS, we discuss all of the known ROS-producing sites (shown in vitro) and their relevance to the mitochondrial ROS production in vivo.