32 research outputs found

    Acquisition of Human-Type Receptor Binding Specificity by New H5N1 Influenza Virus Sublineages during Their Emergence in Birds in Egypt

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    Highly pathogenic avian influenza A virus subtype H5N1 is currently widespread in Asia, Europe, and Africa, with 60% mortality in humans. In particular, since 2009 Egypt has unexpectedly had the highest number of human cases of H5N1 virus infection, with more than 50% of the cases worldwide, but the basis for this high incidence has not been elucidated. A change in receptor binding affinity of the viral hemagglutinin (HA) from α2,3- to α2,6-linked sialic acid (SA) is thought to be necessary for H5N1 virus to become pandemic. In this study, we conducted a phylogenetic analysis of H5N1 viruses isolated between 2006 and 2009 in Egypt. The phylogenetic results showed that recent human isolates clustered disproportionally into several new H5 sublineages suggesting that their HAs have changed their receptor specificity. Using reverse genetics, we found that these H5 sublineages have acquired an enhanced binding affinity for α2,6 SA in combination with residual affinity for α2,3 SA, and identified the amino acid mutations that produced this new receptor specificity. Recombinant H5N1 viruses with a single mutation at HA residue 192 or a double mutation at HA residues 129 and 151 had increased attachment to and infectivity in the human lower respiratory tract but not in the larynx. These findings correlated with enhanced virulence of the mutant viruses in mice. Interestingly, these H5 viruses, with increased affinity to α2,6 SA, emerged during viral diversification in bird populations and subsequently spread to humans. Our findings suggested that emergence of new H5 sublineages with α2,6 SA specificity caused a subsequent increase in human H5N1 influenza virus infections in Egypt, and provided data for understanding the virus's pandemic potential

    Global patterns in monthly activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus: a systematic analysis

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    Background: Influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus are the most common viruses associated with acute lower respiratory infections in young children (<5 years) and older people (≥65 years). A global report of the monthly activity of these viruses is needed to inform public health strategies and programmes for their control. Methods: In this systematic analysis, we compiled data from a systematic literature review of studies published between Jan 1, 2000, and Dec 31, 2017; online datasets; and unpublished research data. Studies were eligible for inclusion if they reported laboratory-confirmed incidence data of human infection of influenza virus, respiratory syncytial virus, parainfluenza virus, or metapneumovirus, or a combination of these, for at least 12 consecutive months (or 52 weeks equivalent); stable testing practice throughout all years reported; virus results among residents in well-defined geographical locations; and aggregated virus results at least on a monthly basis. Data were extracted through a three-stage process, from which we calculated monthly annual average percentage (AAP) as the relative strength of virus activity. We defined duration of epidemics as the minimum number of months to account for 75% of annual positive samples, with each component month defined as an epidemic month. Furthermore, we modelled monthly AAP of influenza virus and respiratory syncytial virus using site-specific temperature and relative humidity for the prediction of local average epidemic months. We also predicted global epidemic months of influenza virus and respiratory syncytial virus on a 5° by 5° grid. The systematic review in this study is registered with PROSPERO, number CRD42018091628. Findings: We initally identified 37 335 eligible studies. Of 21 065 studies remaining after exclusion of duplicates, 1081 full-text articles were assessed for eligibility, of which 185 were identified as eligible. We included 246 sites for influenza virus, 183 sites for respiratory syncytial virus, 83 sites for parainfluenza virus, and 65 sites for metapneumovirus. Influenza virus had clear seasonal epidemics in winter months in most temperate sites but timing of epidemics was more variable and less seasonal with decreasing distance from the equator. Unlike influenza virus, respiratory syncytial virus had clear seasonal epidemics in both temperate and tropical regions, starting in late summer months in the tropics of each hemisphere, reaching most temperate sites in winter months. In most temperate sites, influenza virus epidemics occurred later than respiratory syncytial virus (by 0·3 months [95% CI −0·3 to 0·9]) while no clear temporal order was observed in the tropics. Parainfluenza virus epidemics were found mostly in spring and early summer months in each hemisphere. Metapneumovirus epidemics occurred in late winter and spring in most temperate sites but the timing of epidemics was more diverse in the tropics. Influenza virus epidemics had shorter duration (3·8 months [3·6 to 4·0]) in temperate sites and longer duration (5·2 months [4·9 to 5·5]) in the tropics. Duration of epidemics was similar across all sites for respiratory syncytial virus (4·6 months [4·3 to 4·8]), as it was for metapneumovirus (4·8 months [4·4 to 5·1]). By comparison, parainfluenza virus had longer duration of epidemics (6·3 months [6·0 to 6·7]). Our model had good predictability in the average epidemic months of influenza virus in temperate regions and respiratory syncytial virus in both temperate and tropical regions. Through leave-one-out cross validation, the overall prediction error in the onset of epidemics was within 1 month (influenza virus −0·2 months [−0·6 to 0·1]; respiratory syncytial virus 0·1 months [−0·2 to 0·4]). Interpretation: This study is the first to provide global representations of month-by-month activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus. Our model is helpful in predicting the local onset month of influenza virus and respiratory syncytial virus epidemics. The seasonality information has important implications for health services planning, the timing of respiratory syncytial virus passive prophylaxis, and the strategy of influenza virus and future respiratory syncytial virus vaccination. Funding: European Union Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU)

    Therapeutic Dialogues in Symphony

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    This article chronicles the implementation of a therapeutic workshop aimed at incorporating musical improvisation in therapy through collaborative work based on dialogical practices. The idea behind the workshop is to highlight the differences between traditional music and art therapies and improvisation and collaborative approaches. Its aim is to be innovative in the way musical resources are employed in psychology, taking them beyond a supportive role in managing well-being, and using them as a tool in dialogical and relational therapies for the expression of ideas, experiences, feelings, and stories that therapeutically assist in the construction of understanding of the stories and events in a diversity of participants. (PsycINFO Database Record (c) 2020 APA, all rights reserved

    Antioxidant Capacity and UPLC-PDA ESI-MS Phenolic Profile of Stevia rebaudiana Dry Powder Extracts Obtained by Ultrasound Assisted Extraction

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    Stevia leaves, which are commonly used as a natural sweetener in food products, have increased in importance for antioxidant delivery due to their high content of phenolic compounds. In this study, the influence of the drying process on stevia leaves, with regards to phenolic content and antioxidant activity during drying kinetics 40 &deg;C for 7 h, was studied. The effect of solvent concentration and extraction time using a 32 factorial design on total phenol content (TPC), and on antioxidant activity of extracts obtained from dried stevia leaves, by ultrasound assisted extraction (UAE) as alternative method was evaluated. Steviol glycosides contents were also evaluated by a conventional and UAE method. Phenols identification, quantification and purification were performed by Ultra Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (UPLC-ESI-MS), Ultra Performance Liquid Chromatography-Photodiode Array (UPLC-PDA) and advanced automated flash purification, respectively. Drying time affected the moisture content of stevia leaves. A constant weight was reached after six hours of drying, and higher antioxidant activity was observed, while the highest TPC was obtained after seven hours of drying. The highest TPC (91.57 &plusmn; 8.8 mg GAE/g dw) and antioxidant activity (603.24 &plusmn; 3.5 &mu;mol TE/g dw) in UAE method was obtained when ethanol 50% at 5 min was used. Steviol glycosides extracted by UAE were recorded with a content of 93.18 &plusmn; 1.36 mg/g dw and 98.97 &plusmn; 1.75 mg/g dw for stevioside and rebaudioside A respectively. Six phenolic compounds including four phenolic acids and two flavonoids were identified and quantified by UPLC-PDA, and confirmed by ESI-MS reporting its fragmentation pattern. Diosmin and chlorogenic acid were the most abundant compounds with values of 2032.36 &mu;g/mL and 434.95 &mu;g/mL respectively. As a novelty we found that the antioxidant activity evaluated in partially purified fractions suggested that biological activity might be attributed to the synergistic effect of the six phenols present in the stevia leaves extract. In addition to its sweeting properties, stevia leaves constitute a potential source of polyphenolic compounds, with antioxidant activity that could be used as a food additive

    Evaluation of Pectin Extraction Conditions and Polyphenol Profile from Citrus x lantifolia Waste: Potential Application as Functional Ingredients

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    The citrus by-products pectin and polyphenols were obtained from Citrus x lantifolia residues. The use of acid type, solute-solvent ratio, temperature, and extraction time on pectin yield recovery was evaluated using a factorial design 34; pectin physicochemical characterization, polyphenol profile, and antioxidant activity were also determined. Results indicated a total polyphenol content of 3.92 ± 0.06 mg Galic Acid Equivalents (GAE)/g of citrus waste flour in dry basis (DB), with antioxidant activity of 74%. The presence of neohesperidin (0.96 ± 0.09 mg/g of citrus flour DB), hesperidin (0.27 ± 0.0 mg/g of citrus flour DB), and ellagic acid (0.18 ± 0.03 mg/g of citrus flour DB) as major polyphenols was observed. All of the factors evaluated in pectin recovery presented significant effects (p &lt; 0.05), nevertheless the acid type and solute-solvent ratio showed the greatest effect. The highest yield of pectin recovery (36%) was obtained at 90 °C for 90 min, at a ratio of 1:80 (w/v) using citric acid. The evaluation of pectin used as a food ingredient in cookies elaboration, resulted in a reduction of 10% of fat material without significant texture differences (p &lt; 0.05). The pectin extraction conditions and characterization from these residues allowed us to determine the future applications of these materials for use in several commercial applications

    Phenolic compounds in mango fruit: a review

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    Mangifera indica fruit (mango) is one of the most commercialized fruits around the world occupying the 2nd position as a tropical crop, due to the great variety of existing cultivars from which different food products such as drinks, juices, concentrates, and jams are prepared. The wastes generated during the processing of this fruit (20 million tons), which represent up to 60% of the weight of the fruit and consist mainly of peels (12%) and kernels seeds (20%), cause a series of environmental and economic problems for entrepreneurs in the sector. This is because there are no clear policies for its disposal and reuse. Nevertheless, the development of biotechnological tools has led to these wastes becoming subject of interest for their use in multiple industries such as food and pharmaceuticals, since it has been shown that they can be used as raw material to obtain phenolic compounds with biological activities (antioxidant, antimicrobial, anticancer, etc.). This review compiles the most relevant works from 2016 to 2021 about extraction, quantification, identification, biological activities, and applications of phenolic compounds obtained from the mango tree, with special focus on the fruit, with the objective to promote the use of mango from a sustainable perspective, and with a biorefinery approach.CONACYT: 723724, FORDECYT: 2017-10. Ministerio de Ciencia e Innovación de España: CTQ2017-86170-R, RTI2018-095291-B-I00. Generalitat Valenciana: PROMETEOII/2018/076 (AEP045). Consejo De Ciencia, Innovación Y Tecnología Del Estado De Chiapas

    The risk of Aedes aegypti breeding and premises condition in South Mexico.

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    A recent innovation instrumented for the Dengue Prevention and Control program in Mexico is the use of the premises condition index (PCI) as an indicator of risk for the vector Aedes aegypti infestation in dengue-endemic localities of Mexico. This paper addresses whether further improvements for the dengue control program could be made if the prevalence and productivity of Ae. aegypti populations could be reliably predicted using PCI at the household level, as well as medium-sized neighborhoods. We evaluated the use of PCI to predict the infestation with Aedes aegypti (breeding sites and immature productivity) in Merida, Mexico. The study consisted of a cross-sectional survey based on a cluster-randomized sampling design. We analyzed the statistical association between Aedes infestation and PCI, the extent to which the 3 components of PCI (house maintenance, and tidiness and shading of the patio) contributed to the association between PCI and infestation and whether infestation in a given premises was also affected by the PCI of the surrounding ones. Premises with the lowest PCI had significantly lower Aedes infestation and productivity; and as PCI scores increased infestation levels also tended to increase. Household PCI was significantly associated with Ae. aegypti breeding, largely due to the effect of patio untidiness and patio shade. The mean PCI within the surroundings premises also had a significant and independent explanatory power to predict the risk for infestation, in addition to individual PCI. This is the 1st study in Mexico showing evidence that premises condition as measured by the PCI is related to Ae. aegypti breeding sites and immature productivity. Results suggest that PCI could be used to streamline surveys to inform control efforts at least where Ae. aegypti breeds outdoors, as in Merida. The effect of individual premises, neighborhood condition, and the risk of Aedes infestation imply that the risk for dengue vector infestation can only be minimized by the mass effect at the community level
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