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Nanoparticles are increasingly being studied as antigen delivery systems for immunization with nasal vaccines. The addition of adjuvants is still generally required in many nanoparticle formulations, which can induce potential side effects owing to mucosal reactogenicity. In contrast, maltodextrin nanoparticles do not require additional immunomodulators, and have been shown to be efficient vaccine delivery systems. In this review, the development of maltodextrin nanoparticles is presented, specifically their physico-chemical properties, their ability to load antigens and deliver them into airway mucosal cells, and the extent to which they trigger protective immune responses against bacterial, viral, and parasitic infections. We demonstrate that the addition of lipids to maltodextrin nanoparticles increases their potency as a vaccine delivery system for nasal administration.
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ABSTRACT: Objective : The hemodynamic parameters used to accurately predict fluid responsiveness (FR) in spontaneously breathing patients (SB) require specific material and expertise. Measurements of the central venous pressure (CVP) are relatively simple and, importantly, are feasible in many critically ill patients. We analyzed the accuracy of respiration-related variations in CVP (vCVP) to predict FR in SB patients and examined the optimization of its measurement using a standardized, deep inspiratory maneuver. Patients and Methods : We performed a monocentric, prospective, diagnostic evaluation. Spontaneously breathing patients in intensive care units with a central venous catheter were prospectively included. The vCVP was measured while the patient was spontaneously breathing, both with (vCVP-st) and without (vCVP-ns) a standardized inspiratory maneuver, and calculated as: Minimum inspiratory v-wave peak pressure - Maximum expiratory v-wave peak pressure. A passive leg raising-induced increase in the left ventricular outflow tract velocity-time integral ≥10% defined FR. Results : Among 63 patients, 38 (60.3%) presented FR. The vCVP-ns was not significantly different between responders and nonresponders (-4.9 mm Hg [-7.5 to -3.1] vs. -4.1 mm Hg [-5.4 to 2.8], respectively; P = 0.15). The vCVP-st was lower in responders than nonresponders (-9.7 mm Hg [-13.9 to -6.2] vs. -3.6 mm Hg [-10.6 to -1.6], respectively; P = 0.004). A vCVP-st < -4.7 mm Hg predicted FR with 89.5% sensitivity, a specificity of 56.0%, and an area under the receiver operating characteristic curve of 0.72 (95% CI, 0.58 to 0.86) ( P = 0.004). Conclusion : When a central venous catheter is present, elevated values for vCVP-st may be useful to identify spontaneously breathing patients unresponsive to volume expansion. Nevertheless, the necessity of performing a standardized, deep-inspiration maneuver may limit its clinical application.
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Hidratação , Hemodinâmica , Humanos , Pressão Venosa Central , Estudos Prospectivos , Hidratação/métodos , Respiração , Volume SistólicoRESUMO
Sepsis-induced myopathy is characterized by muscle fiber atrophy, mitochondrial dysfunction, and worsened outcomes. Whether whole-body energy deficit participates in the early alteration of skeletal muscle metabolism has never been investigated. Three groups were studied: "Sepsis" mice, fed ad libitum with a spontaneous decrease in caloric intake (n = 17), and "Sham" mice fed ad libitum (Sham fed (SF), n = 13) or subjected to pair-feeding (Sham pair fed (SPF), n = 12). Sepsis was induced by the intraperitoneal injection of cecal slurry in resuscitated C57BL6/J mice. The feeding of the SPF mice was restricted according to the food intake of the Sepsis mice. Energy balance was evaluated by indirect calorimetry over 24 h. The tibialis anterior cross-sectional area (TA CSA), mitochondrial function (high-resolution respirometry), and mitochondrial quality control pathways (RTqPCR and Western blot) were assessed 24 h after sepsis induction. The energy balance was positive in the SF group and negative in both the SPF and Sepsis groups. The TA CSA did not differ between the SF and SPF groups, but was reduced by 17% in the Sepsis group compared with the SPF group (p < 0.05). The complex-I-linked respiration in permeabilized soleus fibers was higher in the SPF group than the SF group (p < 0.05) and lower in the Sepsis group than the SPF group (p < 0.01). Pgc1α protein expression increased 3.9-fold in the SPF mice compared with the SF mice (p < 0.05) and remained unchanged in the Sepsis mice compared with the SPF mice; the Pgc1α mRNA expression decreased in the Sepsis compared with the SPF mice (p < 0.05). Thus, the sepsis-like energy deficit did not explain the early sepsis-induced muscle fiber atrophy and mitochondrial dysfunction, but led to specific metabolic adaptations not observed in sepsis.
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N-carboxymethyl-lysine (CML) and other dietary advanced glycation end-products (AGEs) are chemically modified amino acids with potential toxicological effects putatively related to their affinity with the receptor for AGEs (RAGE). The goal of this study was to determine the postprandial kinetics of CML in both rodents and humans and, in the latter, to evaluate their relationship with the soluble RAGE isoforms (sRAGE). Four gavage solutions containing different forms of CML were given to rats, and blood was collected over 8 h. Three different breakfasts containing dietary CML (dCML) were administered to 20 healthy volunteers, and blood was collected over 2 h. Concentrations of CML, CEL, and lysine were quantified in plasma and human meals by LC-MS/MS, and sRAGE was determined in human plasma by ELISA. The results showed that dCML did not affect the concentrations of circulating protein-bound CML and that only free CML increased in plasma, with a postprandial peak at 90 to 120 min. In humans, the postprandial plasmatic sRAGE concentration decreased independently of the dAGE content of the breakfasts. This study confirms reports of the inverse postprandial relationship between plasmatic free CML and sRAGE, though this requires further investigation for causality to be established.
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Produtos Finais de Glicação Avançada , Lisina , Animais , Biomarcadores , Desjejum , Cromatografia Líquida , Produtos Finais de Glicação Avançada/metabolismo , Humanos , Lisina/análogos & derivados , Lisina/metabolismo , Ratos , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Espectrometria de Massas em TandemRESUMO
BACKGROUND & AIMS: High hydrostatic pressure (HHP) processing is a non-thermal method proposed as an alternative to Holder pasteurization (HoP) for the treatment of human milk. HHP preserves numerous milk bioactive components that are degraded by HoP, but no data are available for milk oligosaccharides (HMOs) or the formation of Maillard reaction products, which may be deleterious for preterm newborns. METHODS: We evaluated the impact of HHP processing of human milk on 22 HMOs measured by liquid chromatography with fluorescence detection and on furosine, lactuloselysine, carboxymethyllysine (CML) and carboxyethyllysine (CEL) measured by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS), four established indicators of the Maillard reaction. Human raw milk was sterilized by HoP (62.5 °C for 30 min) or processed by HHP (350 MPa at 38 °C). RESULTS: Neither HHP nor HoP processing affected the concentration of HMOs, but HoP significantly increased furosine, lactuloselysine, CML and CEL levels in milk. CONCLUSIONS: Our findings demonstrate that HPP treatment preserves HMOs and avoids formation of Maillard reaction products. Our study confirms and extends previous findings that HHP treatment of human milk provides safe milk, with fewer detrimental effects on the biochemically active milk components than HoP.
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Manipulação de Alimentos/métodos , Produtos Finais de Glicação Avançada/síntese química , Pressão Hidrostática , Leite Humano/química , Oligossacarídeos/química , Cromatografia Líquida , Humanos , Espectrometria de Massas em TandemRESUMO
Diagnostic, monitoring, response, predictive, risk, and prognostic biomarkers of disease are all widely studied, for the most part in biological fluids or tissues, but there is steadily growing interest in alternative matrices such as nails. Here we comprehensively review studies dealing with molecular or elemental biomarkers of disease, as opposed to semiological, pharmacological, toxicological, or biomonitoring studies. Nails have a long history of use in medicine as indicators of pathological processes and have also been used extensively as a matrix for monitoring exposure to environmental pollution. Nail clippings are simple to collect noninvasively as well as to transport and store, and the matrix itself is relatively stable. Nails incorporate, and are influenced by, circulating molecules and elements over their several months of growth, and it is widely held that markers of biological processes will remain in the nail, even when their levels in blood have declined. Nails thus offer the possibility to not only look back into a subject's metabolic history but also to study biomarkers of processes that operate over a longer time scale such as the post-translational modification of proteins. Reports on ungual biomarkers of metabolic and endocrine diseases, cancer, and psychological and neurological disorders will be presented, and an overview of the sampling and analytical techniques provided.
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Unhas , Biomarcadores/metabolismo , Humanos , Unhas/metabolismoRESUMO
OBJECTIVE: Our primary aim was to assess selected metabolic dysfunction parameters, both independently and as a complement to the SOFA score, as predictors of short-term mortality in patients with infection admitted to the intensive care unit (ICU). METHODS: We retrospectively enrolled all consecutive adult patients admitted to the eight ICUs of Lille University Hospital, between January 2015 and September 2016, with suspected or confirmed infection. We selected seven routinely measured biological and clinical parameters of metabolic dysfunction (maximal arterial lactatemia, minimal and maximal temperature, minimal and maximal glycaemia, cholesterolemia, and triglyceridemia), in addition to age and the Charlson's comorbidity score. All parameters and SOFA scores were recorded within 24 h of admission. RESULTS: We included 956 patients with infection, among which 295 (30.9%) died within 90 days. Among the seven metabolic parameters investigated, only maximal lactatemia was associated with higher risk of 90-day hospital mortality in SOFA-adjusted analyses (SOFA-adjusted OR, 1.17; 95%CI, 1.10 to 1.25; p < 0.001). Age and the Charlson's comorbidity score were also statistically associated with a poor prognosis in SOFA-adjusted analyses. We were thus able to develop a metabolic failure, age, and comorbidity assessment (MACA) score based on scales of lactatemia, age, and the Charlson's score, intended for use in combination with the SOFA score. CONCLUSIONS: The maximal lactatemia level within 24 h of ICU admission is the best predictor of short-term mortality among seven measures of metabolic dysfunction. Our combined "SOFA + MACA" score could facilitate early detection of patients likely to develop severe infections. Its accuracy requires further evaluation.
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Chronic Low-Grade Inflammation (CLGI) is a non-overt inflammatory state characterized by a continuous activation of inflammation mediators associated with metabolic diseases. It has been linked to the overconsumption of Advanced Glycation End-Products (AGEs), and/or macronutrients which lead to an increase in local and systemic pro-inflammatory biomarkers in humans and animal models. This review provides a summary of research into biomarkers of diet-induced CLGI in murine models, with a focus on AGEs and obesogenic diets, and presents the physiological effects described in the literature. Diet-induced CLGI is associated with metabolic endotoxemia, and/or gut microbiota remodeling in rodents. The mechanisms identified so far are centered on pro-inflammatory axes such as the interaction between AGEs and their main receptor AGEs (RAGE) or increased levels of lipopolysaccharide. The use of murine models has helped to elucidate the local and systemic expression of CLGI mediators. These models have enabled significant advances in identification of diet-induced CLGI biomarkers and resultant physiological effects. Some limitations on the translational (murine â humans) use of biomarkers may arise, but murine models have greatly facilitated the testing of specific dietary components. However, there remains a lack of information at the whole-organism level of organization, as well as a lack of consensus on the best biomarker for use in CLGI studies and recommendations as to future research conclude this review.
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Biomarcadores/análise , Dieta/efeitos adversos , Ingestão de Energia , Produtos Finais de Glicação Avançada/efeitos adversos , Inflamação/metabolismo , Adipocinas/análise , Animais , Doença Crônica , Citocinas/análise , Modelos Animais de Doenças , Microbioma Gastrointestinal/fisiologia , Humanos , Inflamação/fisiopatologia , CamundongosRESUMO
The Maillard reaction, also called glycation, is one of the major chemical reactions responsible for most yellow-to-brown colors and aromas in cooked foods. This reaction between reducing sugars and amino functions on proteins affects not only the flavor of food, but also leads to the formation of an heterogenous group of structurally-modified amino acids. Some of these, known as "advanced glycation end products" (AGEs), have been found in both foods and human biological fluids, tissues and organs. Except for those that are formed over long periods in vivo at 37 °C, AGEs in the body originate from the digestion and absorption of dietary sources. A high or chronic exposure to dietary AGEs (dAGEs) is suspected as potentially detrimental to human health and studies in the field of food safety have begun to focus their attention on the metabolic transit of dAGEs. This review presents some important findings in this field, with a focus on NÆ-carboxymethyllysine, and presents the evidence for and against an association between intake of dAGEs and their presence in the body. New and promising avenues of research are described, and some future directions outlined.
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Digestão/fisiologia , Produtos Finais de Glicação Avançada/metabolismo , Lisina/análogos & derivados , Aminoácidos/química , Aminoácidos/metabolismo , Dieta , Humanos , Lisina/metabolismoRESUMO
BACKGROUND: The collapsibility index of the inferior vena cava (cIVC) has potential for predicting fluid responsiveness in spontaneously breathing patients, but a standardized approach for measuring the inferior vena cava diameter has yet to be established. The aim was to test the accuracy of different measurement sites of inferior vena cava diameter to predict fluid responsiveness in spontaneously breathing patients with sepsis-related circulatory failure and examine the influence of a standardized breathing manoeuvre. RESULTS: Among the 81 patients included in the study, the median Simplified Acute Physiologic Score II was 34 (24; 42). Sepsis was of pulmonary origin in 49 patients (60%). Median volume expansion during the 24 h prior to study inclusion was 1000 mL (0; 2000). Patients were not severely ill: none were intubated, only 20% were on vasopressors, and all were apparently able to perform a standardized breathing exercise. Forty-one (51%) patients were responders to volume expansion (i.e. a ≥ 10% stroke volume index increase). The cIVC was calculated during non-standardized (cIVC-ns) and standardized breathing (cIVC-st) conditions. The accuracy with which both cIVC-ns and cIVC-st predicted fluid responsiveness differed significantly by measurement site (interaction p < 0.001 and < 0.0001, respectively). Measuring inferior vena cava diameters 4 cm caudal to the right atrium predicted fluid responsiveness with the best accuracy. At this site, a standardized breathing manoeuvre also significantly improved predictive power: areas under ROC curves [mean and (95% CI)] for cIVC-ns = 0.85 [0.78-0.94] versus cIVC-st = 0.98 [0.97-1.0], p < 0.001. When cIVC-ns is superior or equal to 33%, fluid responsiveness is predicted with a sensitivity of 66% and a specificity of 92%. When cIVC-st is superior or equal to 44%, fluid responsiveness is predicted with a sensitivity of 93% and a specificity of 98%. CONCLUSION: The accuracy with which cIVC measurements predict fluid responsiveness in spontaneously breathing patients depends on both the measurement site of inferior vena cava diameters and the breathing regime. Measuring inferior vena cava diameters during a standardized inhalation manoeuvre at 4 cm caudal to the right atrium seems to be the method by which to obtain cIVC measurements best-able to predict patients' response to volume expansion.
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Manipulation of circulating histidine-containing dipeptides (HCD) has been shown to affect the development of diabetes and early-stage diabetic nephropathy (DN). The aim of the present study was to investigate whether such interventions, which potentially alter levels of circulating HCD, also affect the development of advanced-stage DN. Two interventions, aerobic exercise training and overexpression of the human carnosinase-1 (hCN1) enzyme, were tested. BTBR ob/ob mice were either subjected to aerobic exercise training (20 wk) or genetically manipulated to overexpress hCN1, and different diabetes- and DN-related markers were compared with control ob/ob and healthy (wild-type) mice. An acute exercise study was performed to elucidate the effect of obesity, acute running, and hCN1 overexpression on plasma HCD levels. Chronic aerobic exercise training did not affect the development of diabetes or DN, but hCN1 overexpression accelerated hyperlipidemia and aggravated the development of albuminuria, mesangial matrix expansion, and glomerular hypertrophy of ob/ob mice. In line, plasma, kidney, and muscle HCD were markedly lower in ob/ob versus wild-type mice, and plasma and kidney HCD in particular were lower in ob/ob hCN1 versus ob/ob mice but were unaffected by aerobic exercise. In conclusion, advanced glomerular damage is accelerated in mice overexpressing the hCN1 enzyme but not protected by chronic exercise training. Interestingly, we showed, for the first time, that the development of DN is closely linked to renal HCD availability. Further research will have to elucidate whether the stimulation of renal HCD levels can be a therapeutic strategy to reduce the risk for developing DN.
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Nefropatias Diabéticas/enzimologia , Dipeptidases/biossíntese , Terapia por Exercício , Glomérulos Renais/enzimologia , Músculo Esquelético/enzimologia , Obesidade/enzimologia , Animais , Nefropatias Diabéticas/genética , Nefropatias Diabéticas/patologia , Dipeptidases/genética , Dipeptídeos/metabolismo , Modelos Animais de Doenças , Indução Enzimática , Histidina/análogos & derivados , Histidina/metabolismo , Humanos , Glomérulos Renais/patologia , Camundongos Transgênicos , Músculo Esquelético/patologia , Obesidade/complicações , Obesidade/genética , Obesidade/patologia , Fatores de TempoRESUMO
SCOPE: Type 2 diabetes (T2D) induces organ damage associated with glycation, among other metabolic pathways. While therapeutic strategies have been tested to reduce the formation and impact of glycation products, results remain equivocal. Anti-diabetic therapies using probiotics have been proposed, but their effect upon glycation has not been reported. Here, the effects of the bacterial strain Lactobacillus fermentum ME-3 on glycation and T2D-related complications in a mouse model of T2D are investigated. METHODS & RESULTS: Wild-type LepRdb/+ and diabetic LepRdb/db littermates receive a daily gavage of either water or the probiotic ME-3 strain (1010 CFU). Glycation markers, fructoselysine-derived furosine (FL-furosine) and carboxymethyllysine (CML), are quantified in four major organs and plasma using stable-isotope dilution LC-MS/MS. After 12 weeks of ME-3 treatment, diabetic mice gain less weight and exhibit an apparently improved glucose tolerance. The ME-3 treatment reduces median renal levels of FL-furosine in both genotypes by 12-15%, and renal and pulmonary free-CML in diabetic mice by 30% and 18%, respectively. Attenuated hepatic steatosis and an improved plasma lipid profile are also observed with treatment in both genotypes, while the gut microbiota profile is unchanged. CONCLUSION: L. fermentum ME-3 has therapeutic potential for reducing the formation/accumulation of some glycation products in kidneys and attenuating some common diabetes-related complications.
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Complicações do Diabetes/dietoterapia , Produtos Finais de Glicação Avançada/metabolismo , Limosilactobacillus fermentum , Probióticos/farmacologia , Animais , Complicações do Diabetes/metabolismo , Complicações do Diabetes/fisiopatologia , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/dietoterapia , Microbioma Gastrointestinal/fisiologia , Hemoglobinas Glicadas/análise , Rim/metabolismo , Lipídeos/sangue , Fígado/metabolismo , Fígado/fisiologia , Lisina/análogos & derivados , Lisina/metabolismo , Masculino , Receptores para Leptina/genética , Aumento de Peso/efeitos dos fármacosRESUMO
Global Lung Initiative spirometry references satisfactorily fit data of healthy 3- to 15-year-old French children http://bit.ly/2Z2922R.
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This study aimed to evaluate the nutritional value of pasta enriched with legume or wheat gluten proteins and dried at varying temperature. A total of four isonitrogenous experimental diets were produced using gluten powder/wheat semolina (6/94, g/g) pasta and faba bean flour/wheat semolina (35/65, g/g) pasta dried at either 55°C (GLT and FLT, respectively) or 90°C (FVHT and GVHT, respectively). Experimental diets were fed to ten 1-month-old Wistar rats (body weight=176 (sem 15) g) for 21 d. Growth and nutritional, metabolic and inflammatory markers were measured and compared with an isonitrogenous casein diet (CD). The enrichment with faba bean increased the lysine, threonine and branched amino acids by 97, 23 and 10 %, respectively. Protein utilisation also increased by 75 % (P<0·01) in FLT in comparison to GLT diet, without any effect on the corrected faecal digestibility (P>0·05). Faba bean pasta diets' corrected protein digestibility and utilisation was only 3·5 and 9 %, respectively, lower than the CD. Growth rate, blood composition and muscle weights were not generally different with faba bean pasta diets compared with CD. Corrected protein digestibility was 3 % lower in GVHT than GLT, which may be associated with greater carboxymethyllysine. This study in growing rats clearly indicates improvement in growth performance of rats fed legume-enriched pasta diet compared with rats fed gluten-wheat pasta diet, regardless of pasta drying temperature. This means faba bean flour can be used to improve the protein quality and quantity of pasta.
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BACKGROUND: Early (furosine) and advanced (carboxymethyllysine, CML) products of glycation (AGEs) have been reported as increased in plasma, tissues, and organs of diabetic people, indicating a direct link between glycation and type 2 diabetes (T2D). While murine models present some of the characteristics observed in diabetic humans, their pertinence as models of glycation, particularly for T2D, remains poorly described. The aim of this study was to characterize and compare glycation in several organs of two commonly studied murine models of T2D using stable isotope dilution liquid chromatography tandem mass spectrometry (LC-MS/MS). METHODS: Defining parameters of type 2 diabetes including body weight, fasting glycaemia, and glucose intolerance were measured in three different C57BL6 mouse models of T2D-the genetic LepRdb/db (db/db) model and two diet-induced obesity (DIO) models-and their respective controls. Furosine, free, and protein-bound CML were quantified in kidneys, lungs, heart, and liver by LC-MS/MS. RESULTS: The obesity, hyperglycaemia, and glucose intolerance in db/db mice was accompanied by an increase of furosine and protein-bound CML levels in all organs relative to controls. The DIO models took several months to become obese, exhibited less severe hyperglycaemia and glucose intolerance, while glycation products were not significantly different between these groups (with the exception of furosine in liver and CML in lungs). CONCLUSIONS: The db/db model better reflected the characteristics of human T2D compared with the DIO models and exhibited greater formation and accumulation of both furosine and protein-bound CML in all of the organs tested here.
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Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Intolerância à Glucose/metabolismo , Produtos Finais de Glicação Avançada/metabolismo , Receptores para Leptina/fisiologia , Animais , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Intolerância à Glucose/fisiopatologia , Glicosilação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos EndogâmicosRESUMO
Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains a leading cause of death worldwide, despite the development of various therapeutic strategies. Cardiac dysfunction, also referred to as septic cardiomyopathy, is a frequent and well-described complication of sepsis and associated with worse clinical outcomes. Recent research has increased our understanding of the role of mitochondrial dysfunction in the pathophysiology of septic cardiomyopathy. The purpose of this review is to present this evidence as a coherent whole and to highlight future research directions.
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Doenças Mitocondriais/patologia , Sepse/patologia , Animais , Cardiomiopatias/etiologia , Cardiomiopatias/patologia , DNA Mitocondrial/metabolismo , Humanos , Mitocôndrias/metabolismo , Mitocôndrias/ultraestrutura , Doenças Mitocondriais/complicações , Mitofagia , Óxido Nítrico/metabolismo , Fosforilação Oxidativa , Espécies Reativas de Oxigênio/metabolismo , Sepse/complicações , Transdução de SinaisRESUMO
Electronic cigarette use has raised concern worldwide regarding potential health risks and its position in tobacco cessation strategies. As part of any toxicity assessment, the chemical characterization of e-liquids and their related vapors are among fundamental data to be determined. Considering the lack of available reference methods, we developed and validated several analytical procedures in order to conduct a multicomponent analysis of six e-liquid refills and their resultant vapor emissions (generated by a smoking machine), and compared them with tobacco smoke. We combined several techniques including gas-chromatography, high and ultra-performance liquid chromatography and inductively coupled plasma with mass spectrometry or ultraviolet and flame ionization detection in order to identify the main e-liquid constituents (propylene glycol, glycerol and nicotine), as well as multiple potentially harmful components (trace elements, polycyclic aromatic hydrocarbons (PAHs), pesticides and carbonyl compounds). Regarding propylene glycol, glycerol and nicotine concentrations, the six tested e-liquids comply with the advertised composition and contain only traces of pollutants. Noticeable lower concentrations of trace elements (≤3.4 pg/mL puff), pesticides (Assuntos
Aerossóis/análise
, Sistemas Eletrônicos de Liberação de Nicotina
, Cromatografia Líquida
, Cromatografia Gasosa-Espectrometria de Massas
, Substâncias Perigosas/análise
, Hidrocarbonetos Policíclicos Aromáticos/análise
, Propilenoglicol/análise
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The relevance of Polar Organic Chemical Integrative Samplers (POCIS) was evaluated for the assessment of concentrations of 46 pesticides and 19 pharmaceuticals in a small, peri-urban river with multi-origin inputs. Throughout the period of POCIS deployment, 24h-average water samples were collected automatically, and showed the rapid temporal evolution of concentrations of several micropollutants, as well as permitting the calculation of average concentrations in the water phase for comparison with those estimated from POCIS passive samplers. In the daily water samples, cyproconazol, epoxyconazol and imidacloprid showed high temporal variations with concentrations ranging from under the limit of detection up to several hundreds of ngL-1. Erythromycin, cyprofloxacin and iopromide also increased rapidly up to tens of ngL-1 within a few days. Conversely, atrazine, caffeine, diclofenac, and to a lesser extent carbamazepine and sucralose, were systematically present in the water samples and showed limited variation in concentrations. For most of the substances studied here, the passive samplers gave reliable average concentrations between the minimal and maximal daily concentrations during the time of deployment. For pesticides, a relatively good correlation was clearly established (R2=0.89) between the concentrations obtained by POCIS and those gained from average water samples. A slight underestimation of the concentration by POCIS can be attributed to inappropriate sampling rates extracted from the literature and for our system, and new values are proposed. Considering the all data set, 75% of the results indicate a relatively good agreement between the POCIS and the average water samples concentration (values of the ratio ranging between 0,33 and 3). Note further that this agreement between these concentrations remains valid considering different sampling rates extracted from the literature.