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Rice and quinoa starches are modified with short-chain fatty acids (SCFA) with different SCFA acyl chain lengths and levels of modification. This work is aimed to investigate the impact of modifying rice and quinoa starches with short-chain fatty acids (SCFAs) on various physicochemical properties, including particle size, protein and amylose content, thermal behavior, pasting characteristics, and in vitro digestibility. Both native and SCFA-starches showed comparable particle sizes, with rice starches ranging from 1.58 to 2.22 µm and quinoa starches from 5.18 to 5.72 µm. SCFA modification led to lower protein content in both rice (0.218-0.255 %) and quinoa starches (0.537-0.619 %) compared to their native counterparts. Esterification led to the reduction of gelatinization and pasting temperatures as well as the hardness of the paste of SCFA-starches were reduced while paste clarity increased. The highest level of modification in SCFA-starch was associated with the highest amount of resistant starch fraction. Principal component analysis revealed that modification levels exerted a greater influence on starch properties than the types of SCFA used (acetyl, propionyl, and butyryl). These findings is importance in considering the degree of substitution or level of modification when tailoring starch properties through SCFA modification, with implications for various applications in food applications.
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Amilosa , Ácidos Grasos Volátiles , Oryza , Almidón , Ácidos Grasos Volátiles/química , Almidón/química , Amilosa/química , Oryza/química , Fenómenos Químicos , Chenopodium quinoa/química , Tamaño de la Partícula , Temperatura , EsterificaciónRESUMEN
Although the subcellular dynamics of RNA and proteins are key determinants of cell homeostasis, their characterization is still challenging. Here we present an integrative framework to simultaneously interrogate the dynamics of the transcriptome and proteome at subcellular resolution by combining two methods: localization of RNA (LoRNA) and a streamlined density-based localization of proteins by isotope tagging (dLOPIT) to map RNA and protein to organelles (nucleus, endoplasmic reticulum and mitochondria) and membraneless compartments (cytosol, nucleolus and cytosolic granules). Interrogating all RNA subcellular locations at once enables system-wide quantification of the proportional distribution of RNA. We obtain a cell-wide overview of localization dynamics for 31,839 transcripts and 5,314 proteins during the unfolded protein response, revealing that endoplasmic reticulum-localized transcripts are more efficiently recruited to cytosolic granules than cytosolic RNAs, and that the translation initiation factor eIF3d is key to sustaining cytoskeletal function. Overall, we provide the most comprehensive overview so far of RNA and protein subcellular localization dynamics.
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Retículo Endoplásmico , ARN , ARN/genética , ARN/metabolismo , Fracciones Subcelulares/metabolismo , Retículo Endoplásmico/metabolismo , Proteoma/análisisRESUMEN
Background: Physical activity has been proposed as a context to foster the healthy development of individuals and reduce the risk of many chronic problems. This study evaluates the impact of badminton lessons on health and wellness in young adults with intellectual disabilities (ID). Methods: Eighteen participants with ID (14 males and 4 females, aged 19-26) and with little or no experience in badminton were assigned to an exercise group and a control group. The curriculum selected was Shuttle Time Starter Lessons. The exercise group practiced for 50 min each session, twice a week for 10 lessons with peers, while the control group maintained a regular life schedule. Physiological measures, motor performance, Special Olympics Individual Badminton Skills Assessment; and psychological measures were conducted before and after the program. A Wilcoxon signed-rank test was conducted to compare pre- and post-tests in each group. Results: The significantly reduced resting heart rate, longer walking distances in the 6-minute walk test, and better performance in badminton skills were evident in the exercise group. Further, a significantly increased left frontal alpha asymmetry was seen in the exercise group with participants expressing positive effects after the inclusive badminton program. Finally, resting EEG frontal asymmetry seemed to be reflective of emotion in persons with ID. Conclusions: Shuttle Time Badminton Lessons could be feasible for adults with ID. School teachers and coaches may adapt it to improve health and wellness and acquire badminton skills in adults with ID. In addition, the inclusive environment can motivate their participation.
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BACKGROUND: Cystic Fibrosis (CF) is a genetic disorder affecting around 1 in every 3000 newborns. In the most common mutation, F508del, the defective anion channel, CFTR, is prevented from reaching the plasma membrane (PM) by the quality check control of the cell. Little is known about how CFTR pharmacological rescue impacts the cell proteome. METHODS: We used high-resolution mass spectrometry, differential ultracentrifugation, machine learning and bioinformatics to investigate both changes in the expression and localization of the human bronchial epithelium CF model (F508del-CFTR CFBE41o-) proteome following treatment with VX-809 (Lumacaftor), a drug able to improve the trafficking of CFTR. RESULTS: The data suggested no stark changes in protein expression, yet subtle localization changes of proteins of the mitochondria and peroxisomes were detected. We then used high-content confocal microscopy to further investigate the morphological and compositional changes of peroxisomes and mitochondria under these conditions, as well as in patient-derived primary cells. We profiled several thousand proteins and we determined the subcellular localization data for around 5000 of them using the LOPIT-DC spatial proteomics protocol. CONCLUSIONS: We observed that treatment with VX-809 induces extensive structural and functional remodelling of mitochondria and peroxisomes that resemble the phenotype of healthy cells. Our data suggest additional rescue mechanisms of VX-809 beyond the correction of aberrant folding of F508del-CFTR and subsequent trafficking to the PM.
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Fibrosis Quística , Aminopiridinas , Benzodioxoles , Fibrosis Quística/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Epitelio/metabolismo , Humanos , Recién Nacido , Mitocondrias/metabolismo , Proteoma/metabolismoRESUMEN
Drosophila nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that represent a target for insecticides. Peptide neurotoxins are known to block nAChRs by binding to their target subunits, however, a better understanding of this mechanism is needed for effective insecticide design. To facilitate the analysis of nAChRs we used a CRISPR/Cas9 strategy to generate null alleles for all ten nAChR subunit genes in a common genetic background. We studied interactions of nAChR subunits with peptide neurotoxins by larval injections and styrene maleic acid lipid particles (SMALPs) pull-down assays. For the null alleles, we determined the effects of α-Bungarotoxin (α-Btx) and ω-Hexatoxin-Hv1a (Hv1a) administration, identifying potential receptor subunits implicated in the binding of these toxins. We employed pull-down assays to confirm α-Btx interactions with the Drosophila α5 (Dα5), Dα6, Dα7 subunits. Finally, we report the localisation of fluorescent tagged endogenous Dα6 during Drosophila CNS development. Taken together, this study elucidates native Drosophila nAChR subunit interactions with insecticidal peptide toxins and provides a resource for the in vivo analysis of insect nAChRs.
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Insecticidas , Receptores Nicotínicos , Animales , Bungarotoxinas/metabolismo , Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Insecticidas/toxicidad , Neurotoxinas , Péptidos/metabolismo , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismoRESUMEN
The ability of the cellular immune system to discriminate self from foreign antigens depends on the appropriate calibration of the T cell receptor (TCR) signalling threshold. The lymphocyte homeostatic cytokine interleukin 7 (IL-7) is known to affect TCR thresholding, but the molecular mechanism is not fully elucidated. A better understanding of this process is highly relevant in the context of autoimmune disease therapy and cancer immunotherapy. We sought to characterise the early signalling events attributable to IL-7 priming; in particular, the altered phosphorylation of signal transduction proteins and their molecular localisation to the TCR. By integrating high-resolution proximity- phospho-proteomic and imaging approaches using primary T cells, rather than engineered cell lines or an in vitro expanded T cell population, we uncovered transduction events previously not linked to IL-7. We show that IL-7 leads to dephosphorylation of cytohesin interacting protein (CYTIP) at a hitherto undescribed phosphorylation site (pThr280) and alters the co-localisation of cytohesin-1 with the TCR and LFA-1 integrin. These results show that IL-7, acting via CYTIP and cytohesin-1, may impact TCR activation thresholds by enhancing the co-clustering of TCR and LFA-1 integrin.
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Factores de Intercambio de Guanina Nucleótido/metabolismo , Interleucina-7/farmacología , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Proteoma/metabolismo , Proteómica/métodos , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal/efectos de los fármacos , Linfocitos T/inmunología , Factores de Transcripción/metabolismo , Citoesqueleto de Actina/metabolismo , Donantes de Sangre , Células Cultivadas , Humanos , Activación de Linfocitos/efectos de los fármacos , Fosforilación/efectos de los fármacos , Proteínas Recombinantes/farmacología , Treonina/metabolismoRESUMEN
Resveratrol is a photosensitive, bioactive molecule which has received increasing research interest during the past decade for its antioxidant properties. However, it has low solubility in water or common triglyceride oils. Resveratrol solubilization in oil can only be achieved in essential oils, such as flavour oils, but the stability of emulsions produced with this type of oils is low as they are prone to creaming phenomena and Oswald ripening. In this study, resveratrol was first dissolved in orange oil which was mixed into a medium-chain triglyceride (Miglyol) at different ratios and used as the internal phase of oil-in-water emulsions (O/W). The emulsions were stabilized by octenyl succinic anhydride (OSA) modified rice starch granules using two different ratios of starch particle:oil to study the influence of interfacial coverage on the final emulsion droplet size and emulsion stability. The results of this study indicated that stable Pickering emulsions could be prepared using OSA-modified rice starch granules even at partial coverage conditions. Emulsions prepared at an oil fraction of 0.5 using 30% v/v mixture of orange oil in Miglyol as the dispersed phase seemed to be an appropriate resveratrol carrier system, obtaining encapsulation efficiency values close to 90% which results in emulsions with a resveratrol concentration of 8.45 mg/L. Hence, the emulsions prepared are suitable for food fortification applications.
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Oryza , Emulsiones , Tamaño de la Partícula , Resveratrol , AlmidónRESUMEN
BACKGROUND: Suboptimal diet is the leading cause of global morbidity and mortality. Addressing this problem requires context-specific solutions informed by context-specific data collected by context-specific tools. This study aimed to assess the relative validity of a newly developed brief dietary survey to estimate food intake and adherence to the Food Based Dietary Guidelines for Sri Lankans. METHODS: Between December 2018 and February 2019, we interviewed 94 Sri Lankan adults living in Colombo (Western Province), Kalutara (Western Province), and Trincomalee (Eastern Province). We assessed the relative validity of the Sri Lankan Brief Dietary Survey (SLBDS) with Wilcoxon rank-sum tests, Spearman's Rho correlation coefficients, Bland-Altman plots, and Cohen's kappa tests using a 24-h Dietary Recall (24DR) as reference. RESULTS: Ninety-four adults (40.7 years ±12.6; 66% female) completed both surveys during the same interview. With the exception of 'Fish, pulses, meat and eggs' food group median intake, which was underestimated by the SLBDS compared to the 24DR, there was no strong evidence of difference between median intakes reported by the two methods. Correlation coefficients were highest for 'Milk and dairy products' (0.84) at the food group level and for 'dosa', 'hoppers', 'milk rice', and 'dried fish' (1.00) among individual food and beverages. Visual exploration of Bland-Altman plots showed acceptable agreement between the SLBDS and 24DR, with the SLBDS tending to overestimate consumption as the number of servings of 'Rice, bread, other cereals and yams' and 'Vegetables' consumed increased and slightly underestimate consumption as the number of servings of 'Fish, pulses, meat and eggs', 'Milk and dairy products', and 'Nuts' increased. Kappa values ranged from from 0.59 (95% CI: 0.32-0.86) for 'Vegetables' to 0.81 (95% CI: 0.66-0.96) for 'Fruit' indicating a moderate to strong level of agreement. CONCLUSIONS: Having been developed for and relatively validated with the study population in question, our study shows that the SLBDS can be used as a fit for purpose research tool. Additional research is needed to assess SLBDS test-retest reliability and to validate further the reporting of salt, oil, and coconut intake.
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BACKGROUND: Sri Lanka faces the double burden of over- and undernutrition. To tackle this dual challenge, double duty interventions that improve the quality of the Sri Lankan diet in line with national dietary guidelines have been suggested. The success of these interventions depends upon an understanding of the context-specific factors that impact their uptake within the population. The purpose of this study was threefold: explore household responsibility for food-related labour; understand food decision-making influences; and investigate consumption hierarchies that might impact the distribution of intervention benefits. METHODS: We conducted face-to-face semi-structured interviews with 93 Sri Lankan adults residing in urban Colombo (n = 56), and urban and rural sectors in Kalutara (n = 29) and Trincomalee (n = 8). Interview data were analysed thematically. RESULTS: Findings from this study suggest that women in Sri Lanka continue to shoulder the burden of food-related labour disproportionately to men but that this responsibility is not always a proxy for dietary decision-making power. While men are often absent from the kitchen, their role in food purchasing and payment is prominent in many households. Despite these observed gender differences in food labour and provisioning, "traditional" age- and gender-based consumption hierarchies with negative nutrition consequences for women and children are not common, indicating that Sri Lankan 'table culture' may be changing. CONCLUSION: Dietary interventions with the aim of influencing day-to-day practice should be developed with an awareness of who is responsible for, who is able to perform, and who influences targeted behaviours.
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Starch nanoparticles (SNPs) are a promising choice for the strategic development of new renewable and biodegradable nanomaterials for novel biomedical and pharmaceutical applications when loaded with antibiotics or with anticancer agents as target drug delivery systems. The final properties of the SNPs are strongly influenced by the synthesis method and conditions being a controlled and monodispersed size crucial for these applications. The aim of this work was to synthesize controlled size SNPs through nanoprecipitation and microemulsion methods by modifying main operating parameters regarding the effect of amylose and amylopectin ratio in maize starches. SNPs were characterized by size and shape. SNPs from 59 to 118 nm were obtained by the nanoprecipitation method, registering the higer values when surfactant was added to the aqueous phase. Microemulsion method led to 35-147 nm sizes observing a higher particle formation capacity. The composition of the maize used influenced the final particle size and shape.
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OBJECTIVE: Poor clinical outcomes following peripheral nerve injury (PNI) are partly attributable to the limited rate of neuronal regeneration. Despite numerous potential drug candidates demonstrating positive effects on nerve regeneration rate in preclinical models, no drugs are routinely used to improve restoration of function in clinical practice. A key challenge associated with clinical adoption of drug treatments in nerve injured patients is the requirement for sustained administration of doses associated with undesirable systemic sideeffects. Local controlled-release drug delivery systems could potentially address this challenge, particularly through the use of biomaterials that can be implanted at the repair site during the microsurgical repair procedure. APPROACH: In order to test this concept, this study used various biomaterials to deliver ibuprofen sodium or sulindac sulfide locally in a controlled manner in a rat sciatic nerve injury model. Following characterisation of release parameters in vitro, ethylene vinyl acetate tubes or polylactic-co-glycolic acid wraps, loaded with ibuprofen sodium or sulindac sulfide, were placed around directly-repaired nerve transection or nerve crush injuries in rats. MAIN RESULTS: Ibuprofen sodium, but not sulindac sulfide caused an increase in neurites in distal nerve segments and improvements in functional recovery in comparison to controls with no drug treatment. SIGNIFICANCE: This study showed for the first time that local delivery of ibuprofen sodium using biomaterials improves neurite growth and functional recovery following PNI and provides the basis for future development of drug-loaded biomaterials suitable for clinical translation.
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Materiales Biocompatibles , PPAR gamma/agonistas , Traumatismos de los Nervios Periféricos , Neuropatía Ciática , Animales , Liberación de Fármacos , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Ratas , Nervio Ciático , Neuropatía Ciática/tratamiento farmacológicoRESUMEN
RNA-protein interactions play a pivotal role in cell homeostasis and disease, but current approaches to study them require a considerable amount of starting material, favor the recovery of only a subset of RNA species or are complex and time-consuming. We recently developed orthogonal organic phase separation (OOPS): a quick, efficient and reproducible method to purify cross-linked RNA-protein adducts in an unbiased way. OOPS avoids molecular tagging or the capture of polyadenylated RNA. Instead, it is based on sampling the interface of a standard TRIzol extraction to enrich RNA-binding proteins (RBPs) and their cognate bound RNA. OOPS specificity is achieved by digesting the enriched interfaces with RNases or proteases to release the RBPs or protein-bound RNA, respectively. Here we present a step-by-step protocol to purify protein-RNA adducts, free protein and free RNA from the same sample. We further describe how OOPS can be applied in human cell lines, Arabidopsis thaliana, Schizosaccharomyces pombe and Escherichia coli and how it can be used to study RBP dynamics.
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Fraccionamiento Químico/métodos , Proteoma/aislamiento & purificación , Proteínas de Unión al ARN/aislamiento & purificación , ARN/aislamiento & purificación , Transcriptoma , Línea Celular , Humanos , Proteoma/metabolismo , ARN/metabolismo , Proteínas de Unión al ARN/metabolismo , Flujo de TrabajoRESUMEN
Acetylated, propionylated and butyrylated rice and quinoa starches at different levels of modification and starch concentrations, were used to stabilize oil-in-water starch Pickering emulsions at 10% oil fraction. Short-chain fatty acid modified starch Pickering emulsions (SPEs) were characterized after emulsification and after 50 days of storage. The particle size distribution, microstructure, emulsion index, and stability were evaluated. An increase in starch concentration led to a decrease of emulsion droplet sizes. Quinoa starch has shown the capability of stabilizing Pickering emulsions in both the native and modified forms. The emulsifying capacity of SPEs was improved by increasing the chain length of SCFA. Modified quinoa starch with higher chain lengths (i.e. propionylated and butyrylated), at higher levels of modification, showed higher emulsion index (>71%) and stability over the entire 50 days storage. At optimized formulation, SCFA-starch particles have the potential in stabilizing emulsions for functional foods, pharmaceutical formulations, or industrial food applications.
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Chenopodium quinoa/química , Emulsiones/química , Ácidos Grasos Volátiles/química , Oryza/química , Almidón/química , Tamaño de la Partícula , ReologíaRESUMEN
Following central nervous system (CNS) demyelination, adult oligodendrocyte progenitor cells (OPCs) can differentiate into new myelin-forming oligodendrocytes in a regenerative process called remyelination. Although remyelination is very efficient in young adults, its efficiency declines progressively with ageing. Here we performed proteomic analysis of OPCs freshly isolated from the brains of neonate, young and aged female rats. Approximately 50% of the proteins are expressed at different levels in OPCs from neonates compared with their adult counterparts. The amount of myelin-associated proteins, and proteins associated with oxidative phosphorylation, inflammatory responses and actin cytoskeletal organization increased with age, whereas cholesterol-biosynthesis, transcription factors and cell cycle proteins decreased. Our experiments provide the first ageing OPC proteome, revealing the distinct features of OPCs at different ages. These studies provide new insights into why remyelination efficiency declines with ageing and potential roles for aged OPCs in other neurodegenerative diseases.
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Envejecimiento/metabolismo , Células Precursoras de Oligodendrocitos/metabolismo , Proteoma/metabolismo , Animales , Animales Recién Nacidos , Biomarcadores/metabolismo , Separación Celular , Colesterol/metabolismo , Vaina de Mielina/metabolismo , Enfermedades Neurodegenerativas/patología , Células Precursoras de Oligodendrocitos/citología , Complejo de la Endopetidasa Proteasomal/metabolismo , Pliegue de Proteína , Proteómica , Proteostasis , Ratas Sprague-Dawley , Reproducibilidad de los ResultadosRESUMEN
Protein-RNA interactions regulate all aspects of RNA metabolism and are crucial to the function of catalytic ribonucleoproteins. Until recently, the available technologies to capture RNA-bound proteins have been biased toward poly(A) RNA-binding proteins (RBPs) or involve molecular labeling, limiting their application. With the advent of organic-aqueous phase separation-based methods, we now have technologies that efficiently enrich the complete suite of RBPs and enable quantification of RBP dynamics. These flexible approaches to study RBPs and their bound RNA open up new research avenues for systems-level interrogation of protein-RNA interactions.
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Proteoma/metabolismo , Proteínas de Unión al ARN/metabolismo , ARN/metabolismo , Proteoma/química , Proteómica/métodos , ARN/química , ARN Mensajero/química , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/aislamiento & purificaciónRESUMEN
Pesticide losses from agricultural land to water can result in the environmental deterioration of receiving systems. Mathematical models can make important contributions to risk assessments and catchment management. However, some mechanistic models have high parameter requirements which can make them difficult to apply in data poor areas. In addition, uncertainties in pesticide properties and applications are difficult to account for using models with long run-times. Alternative, simpler, conceptual models are easier to apply and can still be used as a framework for process interpretation. Here, we present a new conceptual model of pesticide behaviour in surface water catchments, based on continuous water balance calculations. Pesticide losses to surface waters are calculated based on the displacement of a limited fraction of the soil pore water during storm events occurring after application. The model was used to describe the behaviour of metaldehyde in a small (2.2 km2) under-drained catchment in Eastern England. Metaldehyde is a molluscicide which has been regularly detected at high concentrations in many drinking water supply catchments. Measured peak concentrations in stream water (to about 9 µg L-1) occurred in the first few storm events after application in mid-August. In each event, there was a quasi-exponential decrease in concentration during hydrograph recession. Peak concentrations decreased in successive events - responding to rainfall but reflecting an effective exhaustion in soil supply due to degradation and dissipation. Uncertain pesticide applications to the catchment were estimated using land cover analysis of satellite data, combined with a Poisson distribution to describe the timing of application. Model performance for both the hydrograph (after calibration of the water balance) and the chemograph was good and could be improved via some minor adjustments in assumptions which yield general insights into the drivers for pesticide transport. The use of remote sensing offers some promising opportunities for estimating catchment-scale pesticide applications and associated losses.
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Agricultura , Plaguicidas , Contaminantes Químicos del Agua , Acetaldehído/análogos & derivados , Inglaterra , Monitoreo del Ambiente , Modelos Teóricos , Movimientos del AguaRESUMEN
BACKGROUND: The consumption of free sugars in the UK is more than double the guideline intake for adults and close to triple for children, with soft drinks representing a significant proportion. The aim of this study was to assess how individual soft drink companies and consumers have responded to calls to reduce sugar consumption, including the soft drink industry levy (SDIL), between 2015 and 2018. METHODS: This was an annual cross-sectional study using nutrient composition data of 7377 products collected online, paired with volume sales data for 195 brands offered by 57 companies. The main outcome measures were sales volume, sugar content and volume of sugars sold by company and category, expressed in total and per capita per day terms. RESULTS: Between 2015 and 2018, the volume of sugars sold per capita per day from soft drinks declined by 30%, equivalent to a reduction of 4.6 g per capita per day. The sales-weighted mean sugar content of soft drinks fell from 4.4 g/100 ml in 2015 to 2.9 g/100 ml in 2018. The total volume sales of soft drinks that are subject to the SDIL (i.e. contain more than 5 g/100 ml of sugar) fell by 50%, while volume sales of low- and zero-sugar (< 5 g/100 ml) drinks rose by 40%. CONCLUSION: Action by the soft drinks industry to reduce sugar in products and change their product portfolios, coupled with changes in consumer purchasing, has led to a significant reduction in the total volume and per capita sales of sugars sold in soft drinks in the UK. The rate of change accelerated between 2017 and 2018, which also implies that the implementation of the SDIL acted as an extra incentive for companies to reformulate above and beyond what was already being done as part of voluntary commitments to reformulation, or changes in sales driven by consumer preferences.
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Bebidas Gaseosas/análisis , Azúcares/provisión & distribución , Estudios Transversales , Femenino , Historia del Siglo XXI , Humanos , Masculino , Reino UnidoRESUMEN
Healthy nerve function provides humans with the control of movement; sensation (such as pain, touch and temperature) and the quality of skin, hair and nails. Injury to this complex system creates a deficit in function, which is slow to recover, and rarely, if ever, returns to what patients consider to be normal. Despite promising results in pre-clinical animal experimentation effective translation is challenged by a current inability to quantify nerve regeneration in human subjects and relate this to measurable and responsible clinical outcomes. In animal models, muscle and nerve tissue samples can be harvested following experimental intervention. This allows direct quantification of muscle mass and quality and quantity of regeneration of axons; such an approach is not applicable in human medicine as it would ensure a significant functional deficit. Nevertheless a greater understanding of this process would allow the relationship that exists between neural and neuromuscular regeneration and functional outcome to be more clearly understood. This article presents a combined commentary of current practice from a specialist clinical unit and research team with regard to laboratory and clinical quantification of nerve regeneration. We highlight how electrophysiological diagnostic methods (which are used with significant recognised limitations in the assessment of clinical medicine) can potentially be used with more validity to interpret and assess the processes of neural regeneration in the clinical context, thus throwing light on the factors at play in translating lab advances into the clinic.
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Regeneración Nerviosa , Traumatismos de los Nervios Periféricos/fisiopatología , Nervios Periféricos/fisiología , Animales , Electrodiagnóstico , Fenómenos Electrofisiológicos , HumanosRESUMEN
Chagas disease is caused by the protozoan Trypanosoma cruzi, affecting around 8 million people worldwide. After host cell invasion, the infective trypomastigote form remains 2-4 hours inside acidic phagolysosomes to differentiate into replicative amastigote form. In vitro acidic-pH-induced axenic amastigogenesis was used here to study this step of the parasite life cycle. After three hours of trypomastigote incubation in amastigogenesis promoting acidic medium (pH 5.0) or control physiological pH (7.4) medium samples were subjected to three rounds of centrifugation followed by ultrafiltration of the supernatants. The resulting exoproteome samples were trypsin digested and analysed by nano flow liquid chromatography coupled to tandem mass spectrometry. Computational protein identification searches yielded 271 and 483 protein groups in the exoproteome at pH 7.4 and pH 5.0, respectively, with 180 common proteins between both conditions. The total amount and diversity of proteins released by parasites almost doubled upon acidic incubation compared to control. Overall, 76.5% of proteins were predicted to be secreted by classical or non-classical pathways and 35.1% of these proteins have predicted transmembrane domains. Classical secretory pathway analysis showed an increased number of mucins and mucin-associated surface proteins after acidic incubation. However, the number of released trans-sialidases and surface GP63 peptidases was higher at pH 7.4. Trans-sialidases and mucins are anchored to the membrane and exhibit an enzyme-substrate relationship. In general, mucins are glycoproteins with immunomodulatory functions in Chagas disease, present mainly in the epimastigote and trypomastigote surfaces and could be enzymatically cleaved and released in the phagolysosome during amastigogenesis. Moreover, evidence for flagella discard during amastigogenesis are addressed. This study provides the first comparative analysis of the exoproteome during amastigogenesis, and the presented data evidence the dynamism of its profile in response to acidic pH-induced differentiation.
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Enfermedad de Chagas/parasitología , Proteómica/métodos , Proteínas Protozoarias/metabolismo , Trypanosoma cruzi/patogenicidad , Enfermedad de Chagas/metabolismo , Cromatografía Liquida , Células HeLa , Interacciones Huésped-Parásitos , Humanos , Concentración de Iones de Hidrógeno , Estadios del Ciclo de Vida , Espectrometría de Masas en Tándem , Trypanosoma cruzi/metabolismoRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.