Displaying publications 21 - 39 of 39 in total

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  1. Sorribes-Dauden R, Peris D, Martínez-Pastor MT, Puig S
    Comput Struct Biotechnol J, 2020;18:3712-3722.
    PMID: 33304466 DOI: 10.1016/j.csbj.2020.10.044
    Iron is an essential micronutrient for most living beings since it participates as a redox active cofactor in many biological processes including cellular respiration, lipid biosynthesis, DNA replication and repair, and ribosome biogenesis and recycling. However, when present in excess, iron can participate in Fenton reactions and generate reactive oxygen species that damage cells at the level of proteins, lipids and nucleic acids. Organisms have developed different molecular strategies to protect themselves against the harmful effects of high concentrations of iron. In the case of fungi and plants, detoxification mainly occurs by importing cytosolic iron into the vacuole through the Ccc1/VIT1 iron transporter. New sequenced genomes and bioinformatic tools are facilitating the functional characterization, evolution and ecological relevance of metabolic pathways and homeostatic networks across the Tree of Life. Sequence analysis shows that Ccc1/VIT1 homologs are widely distributed among organisms with the exception of animals. The recent elucidation of the crystal structure of a Ccc1/VIT1 plant ortholog has enabled the identification of both conserved and species-specific motifs required for its metal transport mechanism. Moreover, recent studies in the yeast Saccharomyces cerevisiae have also revealed that multiple transcription factors including Yap5 and Msn2/Msn4 contribute to the expression of CCC1 in high-iron conditions. Interestingly, Malaysian S. cerevisiae strains express a partially functional Ccc1 protein that renders them sensitive to iron. Different regulatory mechanisms have been described for non-Saccharomycetaceae Ccc1 homologs. The characterization of Ccc1/VIT1 proteins is of high interest in the development of biofortified crops and the protection against microbial-derived diseases.
    Matched MeSH terms: Iron Metabolism Disorders
  2. AlMatar M, Albarri O, Makky EA, Var I, Köksal F
    Curr Drug Targets, 2020;21(13):1326-1343.
    PMID: 32564749 DOI: 10.2174/1389450121666200621193018
    Iron, which is described as the most basic component found in nature, is hard to be assimilated by microorganisms. It has become increasingly complicated to obtain iron from nature as iron (II) in the presence of oxygen oxidized to press (III) oxide and hydroxide, becoming unsolvable at neutral pH. Microorganisms appeared to produce organic molecules known as siderophores in order to overcome this condition. Siderophore's essential function is to connect with iron (II) and make it dissolvable and enable cell absorption. These siderophores, apart from iron particles, have the ability to chelate various other metal particles that have collocated away to focus the use of siderophores on wound care items. There is a severe clash between the host and the bacterial pathogens during infection. By producing siderophores, small ferric iron-binding molecules, microorganisms obtain iron. In response, host immune cells produce lipocalin 2 to prevent bacterial reuptake of siderophores loaded with iron. Some bacteria are thought to produce lipocalin 2-resistant siderophores to counter this risk. The aim of this article is to discuss the recently described roles and applications of bacterial siderophore.
    Matched MeSH terms: Iron/metabolism
  3. Thambiah, S., George, E., Nor Aini, U., Sathar, J., Zarida, H., Mokhtar, A.B.
    MyJurnal
    Management of Beta (β)-thalassaemia intermedia in contrast to β-thalassaemia major patients has no clear guidelines as to indicators of adequate transfusion. Regular blood transfusion suppresses bone marrow erythropoietic activity. Serum soluble transferrin receptor (sTfR) concentration is a marker for erythropoietic activity, with increased sTfR being associated with functional iron deficiency and increased erythropoietic activity. This study aimed to determine the use of sTfR as an indicator of adequate transfusion in adult β-thalassaemia intermedia patients. A cross-sectional study was conducted at Hospital Ampang, Malaysia, for six months. Patient group included six β-thalassaemia intermedia and 34 HbE-β-thalassaemia transfused patients. None of the patients were on regular monthly blood transfusions as in β-thalassaemia major. The control group comprised of 16 healthy subjects with normal haematological parameters. Haemoglobin (Hb) analysis, sTfR and ferritin assays were performed. Hb and HbA percentages (%) were found to be significantly lower in patients compared to the controls, while HbE%, HbF%, sTfR and ferritin were significantly higher in patients. An inverse relationship was found in the controls between HbF% with Hb (r = -0.515, p < 0.05) and HbA% (r = -0.534, p < 0.05). In patients, sTfR showed an inverse relationship with HbA% (r = -0.618, p = 0.000) and a positive correlation with HbE% (r = 0.418, p = 0.007) and HbF% (r = 0.469, p = 0.002). Multivariate analysis showed that HbA% (r = 2.875, p = 0.048), HbE% (r = 2.872, p = 0.020) and HbF% (r = 2.436, p = 0.013) best predicted sTfR independently in patients. Thus, sTfR is a useful marker for erythropoiesis. The elevated sTfR in these patients indicate that the transfusion regimen used was inadequate to suppress ineffective erythropoiesis. Hb levels may not be the best target for monitoring transfusion treatment in β-thalassaemia intermedia patients, but the use of sTfR is helpful in individualising transfusion regimens.
    Matched MeSH terms: Iron Metabolism Disorders
  4. ENG LL, DEWITT G
    Med J Malaysia, 1964 Jun;18:269-75.
    PMID: 14199445
    Matched MeSH terms: Iron/metabolism*
  5. Zhou C, Yu T, Zhu R, Lu J, Ouyang X, Zhang Z, et al.
    Int J Biol Sci, 2023;19(5):1471-1489.
    PMID: 37056925 DOI: 10.7150/ijbs.77979
    Timosaponin AIII (Tim-AIII), a steroid saponin, exhibits strong anticancer activity in a variety of cancers, especially breast cancer and liver cancer. However, the underlying mechanism of the effects of Tim-AIII-mediated anti-lung cancer effects remain obscure. In this study, we showed that Tim-AIII suppressed cell proliferation and migration, induced G2/M phase arrest and ultimately triggered cell death of non-small cell lung cancer (NSCLC) cell lines accompanied by the release of reactive oxygen species (ROS) and iron accumulation, malondialdehyde (MDA) production, and glutathione (GSH) depletion. Interestingly, we found that Tim-AIII-mediated cell death was reversed by ferroptosis inhibitor ferrostatin-1 (Fer-1). Meanwhile, the heat shock protein 90 (HSP90) was predicted and verified as the direct binding target of Tim-AIII by SwissTargetPrediction (STP) and surface plasmon resonance (SPR) assay. Further study showed that Tim-AIII promoted HSP90 expression and Tim-AIII induced cell death was blocked by the HSP90 inhibitor tanespimycin, indicating that HSP90 was the main target of Tim-AIII to further trigger intracellular events. Mechanical analysis revealed that the Tim-AIII-HSP90 complex further targeted and degraded glutathione peroxidase 4 (GPX4), and promoted the ubiquitination of GPX4, as shown by an immunoprecipitation, degradation and in vitro ubiquitination assay. In addition, Tim-AIII inhibited cell proliferation, induced cell death, led to ROS and iron accumulation, MDA production, GSH depletion, as well as GPX4 ubiquitination and degradation, were markedly abrogated when HSP90 was knockdown by HSP90-shRNA transfection. Importantly, Tim-AIII also showed a strong capacity of preventing tumor growth by promoting ferroptosis in a subcutaneous xenograft tumor model, whether C57BL/6J or BALB/c-nu/nu nude mice. Together, HSP90 was identified as a new target of Tim-AIII. Tim-AIII, by binding and forming a complex with HSP90, further targeted and degraded GPX4, ultimately induced ferroptosis in NSCLC. These findings provided solid evidence that Tim-AIII can serve as a potential candidate for NSCLC treatment.
    Matched MeSH terms: Iron/metabolism
  6. Bahari EA, Zaaba NE, Haron N, Dasiman R, Amom Z
    Med Sci Monit Basic Res, 2014;20:170-5.
    PMID: 25381551 DOI: 10.12659/MSMBR.892345
    Roots and leaves of the Cermela Hutan (Phyllanthus gomphocarpus Hook. F) plant were studied to determine antioxidant activity, phytochemical compounds, proportion of carbohydrate, crude protein, moisture, ash, fat, total phenolic content (TPC), and total flavonoid content (TFC).
    Matched MeSH terms: Iron/metabolism
  7. Halmi MI, Zuhainis SW, Yusof MT, Shaharuddin NA, Helmi W, Shukor Y, et al.
    Biomed Res Int, 2013;2013:384541.
    PMID: 24383052 DOI: 10.1155/2013/384541
    Bacteria with the ability to tolerate, remove, and/or degrade several xenobiotics simultaneously are urgently needed for remediation of polluted sites. A previously isolated bacterium with sodium dodecyl sulfate- (SDS-) degrading capacity was found to be able to reduce molybdenum to the nontoxic molybdenum blue. The optimal pH, carbon source, molybdate concentration, and temperature supporting molybdate reduction were pH 7.0, glucose at 1.5% (w/v), between 25 and 30 mM, and 25°C, respectively. The optimum phosphate concentration for molybdate reduction was 5 mM. The Mo-blue produced exhibits an absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. None of the respiratory inhibitors tested showed any inhibition to the molybdenum-reducing activity suggesting that the electron transport system of this bacterium is not the site of molybdenum reduction. Chromium, cadmium, silver, copper, mercury, and lead caused approximately 77, 65, 77, 89, 80, and 80% inhibition of the molybdenum-reducing activity, respectively. Ferrous and stannous ions markedly increased the activity of molybdenum-reducing activity in this bacterium. The maximum tolerable concentration of SDS as a cocontaminant was 3 g/L. The characteristics of this bacterium make it a suitable candidate for molybdenum bioremediation of sites cocontaminated with detergent pollutant.
    Matched MeSH terms: Iron/metabolism
  8. Meera M, Agamuthu P
    Int J Phytoremediation, 2012 Feb;14(2):186-99.
    PMID: 22567704
    Terrestrial plants as potential phytoremediators for remediation of surface soil contaminated with toxic metals have gained attention in clean-up technologies. The potential of kenaf (Hibiscus cannabinus L.) to offer a cost-effective mechanism to remediate Fe and As from landfill leachate-contaminated soil was investigated. Pot experiment employing soil polluted with treatments of Jeram landfill leachate was conducted for 120 days. Plants were harvested after 8th, 12th, and 16th weeks of growth. Accumulation of Fe and As was assessed based on Bioconcentration Factor and Translocation Factor. Results showed sequestration of 0.06-0.58 mg As and 66.82-461.71 mg Fe per g plant dry weight in kenaf root, which implies that kenaf root can be an bioavailable sink for toxic metals. Insignificant amount of Fe and As was observed in the aerial plant parts (< 12% of total bioavailable metals). The ability of kenaf to tolerate these metals and avoid phytotoxicity could be attributed to the stabilization of the metals in the roots and hence reduction of toxic metal mobility (TF < 1). With the application of leachate, kenaf was also found to have higher biomass and subsequently recorded 11% higher bioaccumulation capacity, indicating its suitability for phytoextraction of leachate contaminated sites.
    Matched MeSH terms: Iron/metabolism*
  9. Shukri A, Green S, Bradley DA
    Appl Radiat Isot, 1995 6 1;46(6-7):625.
    PMID: 7633384
    Matched MeSH terms: Iron/metabolism
  10. Ismail A
    Biochem Biophys Res Commun, 1988 Jan 15;150(1):18-24.
    PMID: 2962581
    This study was initiated to determine the mechanism of iron-uptake in Salmonella typhi. When stressed for iron, microorganisms produce siderophores to obtain the necessary nutrient. Generally two types of siderophores exist: the phenolate-type predominantly produced by bacteria and the hydroxamate-type commonly secreted by fungi. Results of this investigation showed that S. typhi produced siderophores of the phenolate-type since culture supernatant of the organism grown under iron-deprivation supported the growth of the phenolate-dependent auxotroph. The culture supernatant when extracted for phenolate siderophores, also supported the growth of the phenolate auxotroph but not the hydroxamate auxotroph. Production of phenolate-type siderophores were further confirmed using biochemical assays. These results showed that S. typhi utilized the high-affinity iron transport system to obtain the necessary iron.
    Matched MeSH terms: Iron/metabolism
  11. Kalidasan V, Joseph N, Kumar S, Awang Hamat R, Neela VK
    PMID: 30483485 DOI: 10.3389/fcimb.2018.00401
    Stenotrophomonas maltophilia is a multi-drug-resistant global opportunistic nosocomial pathogen, which possesses a huge number of virulence factors and antibiotics resistance characteristics. Iron has a crucial contribution toward growth and development, cell growth and proliferation, and pathogenicity. The bacterium found to acquire iron for its cellular process through the expression of two iron acquisition systems. Two distinct pathways for iron acquisition are encoded by the S. maltophilia genome-a siderophore-and heme-mediated iron uptake system. The entAFDBEC operon directs the production of the enterobactin siderophore of catecholate in nature, while heme uptake relies on hgbBC and potentially hmuRSTUV operon. Fur and sigma factors are regulators of S. maltophilia under iron-limited condition. Iron potentially act as a signal which plays an important role in biofilm formation, extracellular polymeric substances (EPS), extracellular enzymes production, oxidative stress response, diffusible signal factor (DSF) and siderophore production in S. maltophilia. This review summarizes the current knowledge of iron acquisition in S. maltophilia and the critical role of iron in relation to its pathogenicity.
    Matched MeSH terms: Iron/metabolism*
  12. Zarei M, Ghanbari R, Tajabadi N, Abdul-Hamid A, Bakar FA, Saari N
    J Food Sci, 2016 Feb;81(2):C341-7.
    PMID: 26720491 DOI: 10.1111/1750-3841.13200
    Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 μM, respectively.
    Matched MeSH terms: Iron/metabolism*
  13. Lee HN, Mostovoy Y, Hsu TY, Chang AH, Brem RB
    G3 (Bethesda), 2013 Dec 09;3(12):2187-94.
    PMID: 24142925 DOI: 10.1534/g3.113.008011
    Comparative genomic studies have reported widespread variation in levels of gene expression within and between species. Using these data to infer organism-level trait divergence has proven to be a key challenge in the field. We have used a wild Malaysian population of S. cerevisiae as a test bed in the search to predict and validate trait differences based on observations of regulatory variation. Malaysian yeast, when cultured in standard medium, activated regulatory programs that protect cells from the toxic effects of high iron. Malaysian yeast also showed a hyperactive regulatory response during culture in the presence of excess iron and had a unique growth defect in conditions of high iron. Molecular validation experiments pinpointed the iron metabolism factors AFT1, CCC1, and YAP5 as contributors to these molecular and cellular phenotypes; in genome-scale sequence analyses, a suite of iron toxicity response genes showed evidence for rapid protein evolution in Malaysian yeast. Our findings support a model in which iron metabolism has diverged in Malaysian yeast as a consequence of a change in selective pressure, with Malaysian alleles shifting the dynamic range of iron response to low-iron concentrations and weakening resistance to extreme iron toxicity. By dissecting the iron scarcity specialist behavior of Malaysian yeast, our work highlights the power of expression divergence as a signpost for biologically and evolutionarily relevant variation at the organismal level. Interpreting the phenotypic relevance of gene expression variation is one of the primary challenges of modern genomics.
    Matched MeSH terms: Iron/metabolism*
  14. Harvinder GS, Swee WC, Karupaiah T, Sahathevan S, Chinna K, Ahmad G, et al.
    Asia Pac J Clin Nutr, 2016;25(1):26-33.
    PMID: 26965758 DOI: 10.6133/apjcn.2016.25.1.01
    Malnutrition is highly prevalent in Malaysian dialysis patients and there is a need for a valid screening tool for early identification and management. This cross-sectional study aims to examine the sensitivity of the Dialysis Malnutrition Score (DMS) and Malnutrition Inflammation Score (MIS) tools in predicting protein-energy wasting (PEW) among Malaysian dialysis patients.
    Matched MeSH terms: Iron/metabolism
  15. Bin Karim MF, Imam H, Sarker MM, Uddin N, Hasan N, Paul N, et al.
    Pak J Pharm Sci, 2015 May;28(3):915-20.
    PMID: 26004725
    In this phyto-pharmacological screening of Pistia stratiotes L leaf and root extracts each separately in two different solvents demonstrated its potential medicinal value. Apparent antioxidant value is demonstrated by DPPH, Nitric oxide scavenging and Ferric ion reducing method. Additionally, total flavonoid and phenolic compounds were measured. The leaf methanolic extract scavenged both nitric oxide (NO) and DPPH radical with a dose dependent manner. But the pet ether fraction of root was found to have highest efficacy in Fe(3±) reducing power assay. Flavonoid was found to contain highest in the pet ether fraction of root (411.35mg/g) in terms of quercetin equivalent, similarly highest amount (34.96mg/g) of total phenolic compounds (assayed as gallic acid equivalents) were found to contain in the same fraction. The methanolic fractions appeared less cytotoxic compared to pet ether extracts. The plant extracts caused a dose dependent decrease in faecal droppings in both castor oil and magnesium sulphate induced diarrhea, where as leaf extracts in each solvent appeared most effective. Also, the plant extracts showed anthelmintic activity in earthworm by inducing paralysis and death in a dose dependent manner. At highest doses (50 mg/ml) all fractions were almost effective as the positive control piperazine citrate (10 mg/ml). Thus, besides this cytotoxic effect it's traditional claim for therapeutic use can never be overlooked.
    Matched MeSH terms: Iron/metabolism
  16. Balveer K, Pyar K, Wonke B
    Med J Malaysia, 2000 Dec;55(4):493-7.
    PMID: 11221163
    Thalassaemics in Malaysia are poorly chelated because desferrioxamine is too expensive and cumbersome for long term compliance. The efficacy and tolerability of the oral chelator deferiprone, and the effects of using a combination therapy in our patients were studied. Ten patients completed the study and the mean serum ferritin reduced from 7066.11 ug/L (2577-12,896 ug/L) to 3242.24 ug/L (955-6120 ug/L). The liver iron concentration did not show a significant drop (19.6 vs 18.2 mg/g dry weight) although 3 patients showed reductions ranging from 30-40%. Concomitant use of desferrioxamine increased the urinary excretion from a mean of 13.66 mg/day to 27.38 mg/day. Main side effects seen were nausea and rashes.
    Matched MeSH terms: Iron/metabolism
  17. Ali Hassan SH, Fry JR, Abu Bakar MF
    Biomed Res Int, 2013;2013:138950.
    PMID: 24288662 DOI: 10.1155/2013/138950
    Garcinia parvifolia belongs to the same family as mangosteen (Garcinia mangostana), which is known locally in Sabah as "asam kandis" or cherry mangosteen. The present study was conducted to determine the phytochemicals content (total phenolic, flavonoid, anthocyanin, and carotenoid content) and antioxidant and acetylcholinesterase inhibition activity of the flesh and peel of G. parvifolia. All samples were freeze-dried and extracted using 80% methanol and distilled water. For the 80% methanol extract, the flesh of G. parvifolia displayed higher phenolic and flavonoid contents than the peel, with values of 7.2 ± 0.3 mg gallic acid equivalent (GAE)/g and 5.9 ± 0.1 mg rutin equivalent (RU)/g, respectively. Anthocyanins were detected in the peel part of G. parvifolia but absent in the flesh. The peel of G. parvifolia displayed higher total carotenoid content as compared to the flesh part with the values of 17.0 ± 0.3 and 3.0 ± 0.0 mg β-carotene equivalents (BC)/100 g, respectively. The free-radical scavenging, ferric reducing, and acetylcholinesterase inhibition effect of the flesh were higher as compared to the peel in both extracts. These findings suggested that the edible part of G. parvifolia fruit has a potential as a natural source of antioxidant and anti-Alzheimer's agents.
    Matched MeSH terms: Iron/metabolism
  18. Zainudin NA, Condon B, De Bruyne L, Van Poucke C, Bi Q, Li W, et al.
    Mol Plant Microbe Interact, 2015 Oct;28(10):1130-41.
    PMID: 26168137 DOI: 10.1094/MPMI-03-15-0068-R
    The Sfp-type 4'-phosphopantetheinyl transferase Ppt1 is required for activation of nonribosomal peptide synthetases, including α-aminoadipate reductase (AAR) for lysine biosynthesis and polyketide synthases, enzymes that biosynthesize peptide and polyketide secondary metabolites, respectively. Deletion of the PPT1 gene, from the maize pathogen Cochliobolus heterostrophus and the rice pathogen Cochliobolus miyabeanus, yielded strains that were significantly reduced in virulence to their hosts. In addition, ppt1 mutants of C. heterostrophus race T and Cochliobolus victoriae were unable to biosynthesize the host-selective toxins (HST) T-toxin and victorin, respectively, as judged by bioassays. Interestingly, ppt1 mutants of C. miyabeanus were shown to produce tenfold higher levels of the sesterterpene-type non-HST ophiobolin A, as compared with the wild-type strain. The ppt1 strains of all species were also reduced in tolerance to oxidative stress and iron depletion; both phenotypes are associated with inability to produce extracellular siderophores biosynthesized by the nonribosomal peptide synthetase Nps6. Colony surfaces were hydrophilic, a trait previously associated with absence of C. heterostrophus Nps4. Mutants were decreased in asexual sporulation and C. heterostrophus strains were female-sterile in sexual crosses; the latter phenotype was observed previously with mutants lacking Nps2, which produces an intracellular siderophore. As expected, mutants were albino, since they cannot produce the polyketide melanin and were auxotrophic for lysine because they lack an AAR.
    Matched MeSH terms: Iron/metabolism
  19. Marvibaigi M, Amini N, Supriyanto E, Abdul Majid FA, Kumar Jaganathan S, Jamil S, et al.
    PLoS One, 2016;11(7):e0158942.
    PMID: 27410459 DOI: 10.1371/journal.pone.0158942
    Scurrula ferruginea (Jack) Danser is one of the mistletoe species belonging to Loranthaceae family, which grows on the branches of many deciduous trees in tropical countries. This study evaluated the antioxidant activities of S. ferruginea extracts. The cytotoxic activity of the selected extracts, which showed potent antioxidant activities, and high phenolic and flavonoid contents, were investigated in human breast cancer cell line (MDA-MB-231) and non-cancer human skin fibroblast cells (HSF-1184). The activities and characteristics varied depending on the different parts of S. ferruginea, solvent polarity, and concentrations of extracts. The stem methanol extract showed the highest amount of both phenolic (273.51 ± 4.84 mg gallic acid/g extract) and flavonoid contents (163.41 ± 4.62 mg catechin/g extract) and strong DPPH• radical scavenging (IC50 = 27.81 μg/mL) and metal chelation activity (IC50 = 80.20 μg/mL). The stem aqueous extract showed the highest ABTS•+ scavenging ability. The stem methanol and aqueous extracts exhibited dose-dependent cytotoxic activity against MDA-MB-231 cells with IC50 of 19.27 and 50.35 μg/mL, respectively. Furthermore, the extracts inhibited the migration and colony formation of MDA-MB-231 cells in a concentration-dependent manner. Morphological observations revealed hallmark properties of apoptosis in treated cells. The methanol extract induced an increase in ROS generation and mitochondrial depolarization in MDA-MB-231 cells, suggesting its potent apoptotic activity. The present study demonstrated that the S. ferruginea methanol extract mediated MDA-MB-231 cell growth inhibition via induction of apoptosis which was confirmed by Western blot analysis. It may be a potential anticancer agent; however, its in vivo anticancer activity needs to be investigated.
    Matched MeSH terms: Iron/metabolism
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