RESUMO
The environmental fate of microplastics (MPs) added to agricultural soils remains poorly understood, particularly regarding their mobility in soils. Here we investigate the potential for MP export from soil to surface waters and groundwater in two agricultural settings with a 20-year history of biosolid treatment. A third site where biosolids had never been applied served as a reference (Field R). The potential for MP export along overland and interflow pathways to surface waters was determined from MP abundances in shallow surface cores (10 cm) along ten down-slope transects (five each for Field A and B), and through MP abundances in effluent from a sub-surface land drain. The risk of vertical MP migration was assessed from 2 m cores, and from MP abundances in groundwater sampled from the core boreholes. XRF Itrax core scanning was conducted on two of the deep cores to capture high-resolution optical and 2-D radiographic imaging. Results suggest limited MP mobility at depths >35 cm, with MPs largely recovered in surface soils characterised by lower compaction. Furthermore, abundances of MPs across the surface cores were comparable, with no evidence of MP accumulations observed. Average MP abundance in the top 10 cm of soil across Field A and B was 365 ± 302 MP kg-1, with 0.3 MP l-1 and 1.6 MP l-1 recovered from the groundwater and field drainpipe water samples, respectively. MP abundances were significantly higher in fields treated with biosolids than in Field R (90 ± 32 MP kg-1 soil). Findings suggest ploughing is the most significant driver of MP mobility in upper soil layers, however the potential for overland or interflow movement cannot be excluded, particularly for fields that may be artificially drained.
Assuntos
Microplásticos , Solo , Plásticos , Biossólidos , Agricultura/métodosRESUMO
Freshwater systems provide key pathways for microplastic (MP) pollution, and although existing studies have demonstrated the susceptibility of freshwater biota to ingestion, translocation, and trophic transfer, specific challenges pertaining to methodological standardization remain largely unresolved, particularly with respect to isolating, characterizing, and assessing MPs. Here, a critical review is performed outlining the challenges and limitations currently faced by freshwater MP researchers, which may well apply across the MP research spectrum. Recommendations are provided for methodological standardization, particularly in MP characterization, quality assurance, and quality control (QA/QC) procedures as well as reporting. Considerations for the assessment of MPs in freshwater biota as a means of improving comparisons between studies are discussed. Technological advancements, including the improvement of laboratory infrastructure for identifying MPs within the smaller size range as well as methodological standardization are essential in providing policy makers with tools and measures necessary to determine the distribution of MPs within freshwater ecosystems, while also allowing for comparability and providing compliance for future monitoring requirements.
RESUMO
Rivers play an important role in the overall transport of microplastic pollution (1 µm to 5 mm), with fluvial dynamics expected to influence biotic interactions, particularly for fish. So far, there have been few assessments of microplastics in freshwater salmonids. The prevalence (i.e. percentage occurrence) and burden (i.e. abundance per fish) of microplastics were assessed in the gastrointestinal tracts (GITs) and stomach contents (SCs) of 58 brown trout Salmo trutta Linnaeus, 1758 sampled at six sites along the River Slaney catchment in south-east Ireland. Sites were divided into two classifications (high and low exposure) based on proximity to microplastic pollution sources, comprising three sites each. Analysis of biological traits (e.g. fish length) and diet was performed on the same fish to determine possible factors explaining microplastic burden. Microplastics were found in 72% of fish having been recovered from 66% of GITs (1.88 ± 1.53 MPs fishâ»1) and 28% of SCs (1.31 ± 0.48 MPs fishâ»1). Fibres were the dominant particle type recovered from GITs (67%) and SCs (57%) followed by fragments. No difference in median microplastic burden was observed between fish collected in high and low exposure sites. Microplastic burden was unrelated to fish fork length, while microplastic size distribution (100 ≤ 350 µm, 350 µm to ≤ 5 mm) was unrelated to S. trutta age class estimates. Furthermore, microplastic burden was not explained by dietary intake. Though further research is necessary, this study showed the presence of microplastics in wild S. trutta collected from an Irish riverine system, which could have further implications for top-level consumers that feed on the species, including humans. Further analysis is required to determine possible trophic linkages for the species, with respect to microplastics, and to assess the suitability of S. trutta for monitoring microplastics in river systems.
Assuntos
Salmonidae , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Conteúdo Gastrointestinal , Humanos , Irlanda , Plásticos , Rios , TrutaRESUMO
BACKGROUND: Hematology analyzers are designed to count whole blood samples, but are also used by blood centers to perform quality control on blood components. In platelet (PLT) concentrates, the number of PLTs is approximately fivefold higher and red blood cells are absent, causing variable PLT counting results. It was our aim to compare currently used hematology analyzers for counting PLTs in PLT concentrates using fixed human PLTs. STUDY DESIGN AND METHODS: PLT samples were fixed, diluted into seven concentration levels (plus one blank), aliquoted, and shipped to 68 centers. Evaluable data were obtained for 89 hematology analyzers. All samples were counted six times, and results were reported to the coordinating center. The overall group mean was calculated, and the percentage deviation from this mean was calculated for each analyzer. RESULTS: At PLT levels relevant for blood centers, 750 x 10(9) to 2000 x 10(9) per L, analyzers gave results that were between 35 percent lower and 16 percent higher than the overall group mean. Within a group of analyzers, results were comparable with coefficient of variations usually below 10 percent, indicating that the observed differences were caused by instrument characteristics. A smaller study with fresh, unfixed PLT samples showed that analyzers behaved similarly for fixed and fresh PLTs. CONCLUSION: With a wide array of currently used hematology analyzers, a marked difference was determined for the PLT counts of fixed human-based identical samples provided to 68 laboratories by a centralized facility. A gold standard method is needed to allow for more valid interlaboratory comparisons between hematology analyzers.
Assuntos
Contagem de Plaquetas/instrumentação , Contagem de Plaquetas/normas , Humanos , Variações Dependentes do Observador , Contagem de Plaquetas/métodos , Controle de QualidadeRESUMO
This pilot study evaluated the effects of supplementation with PUFA on blood FA composition and behavior in children with Attention-Deficit/Hyperactivity Disorder (AD/HD)-like symptoms also reporting thirst and skin problems. Fifty children were randomized to treatment groups receiving either a PUFA supplement providing a daily dose of 480 mg DHA, 80 mg EPA, 40 mg arachidonic acid (AA), 96 mg GLA, and 24 mg alpha-tocopheryl acetate, or an olive oil placebo for 4 mon of double-blind parallel treatment. Supplementation with the PUFA led to a substantial increase in the proportions of EPA, DHA, and alpha-tocopherol in the plasma phospholipids and red blood cell (RBC) total lipids, but an increase was noted in the plasma phospholipid proportions of 18:3n-3 with olive oil as well. Significant improvements in multiple outcomes (as rated by parents) were noted in both groups, but a clear benefit from PUFA supplementation for all behaviors characteristic of AD/HD was not observed. For most outcomes, improvement of the PUFA group was consistently nominally better than that of the olive oil group; but the treatment difference was significant, by secondary intent-to-treat analysis, on only 2 out of 16 outcome measures: conduct problems rated by parents (-42.7 vs. -9.9%, n = 47, P = 0.05), and attention symptoms rated by teachers (-14.8 vs. +3.4%, n = 47, P = 0.03). PUFA supplementation led to a greater number of participants showing improvement in oppositional defiant behavior from a clinical to a nonclinical range compared with olive oil supplementation (8 out of 12 vs. 3 out of 11, n = 33, P = 0.02). Also, significant correlations were observed when comparing the magnitude of change between increasing proportions of EPA in the RBC and decreasing disruptive behavior as assessed by the Abbreviated Symptom Questionnaire (ASQ) for parents (r = -0.38, n = 31, P < 0.05), and for EPA and DHA in the RBC and the teachers' Disruptive Behavior Disorders (DBD) Rating Scale for Attention (r = -0.49, n = 24, P < 0.05). Interestingly, significant correlations were observed between the magnitude of increase in alpha-tocopherol concentrations in the RBC and a decrease in scores for all four subscales of the teachers' DBD (Hyperactivity, r = -0.45; Attention, r= -0.60; Conduct, r = -0.41; Oppositional/Defiant Disorder, r = -0.54; n = 24, P < 0.05) as well as the ASQ for teachers (r = -0.51, n = 24, P < 0.05). Thus, the results of this pilot study suggest the need for further research with both n-3 FA and vitamin E in children with behavioral disorders.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Suplementos Nutricionais , Ácidos Graxos Insaturados/uso terapêutico , Adolescente , Transtorno do Deficit de Atenção com Hiperatividade/sangue , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/sangue , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/tratamento farmacológico , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/psicologia , Criança , Método Duplo-Cego , Ácidos Graxos Insaturados/farmacologia , Feminino , Humanos , Masculino , Azeite de Oliva , Projetos Piloto , Óleos de Plantas/farmacologia , Óleos de Plantas/uso terapêutico , Dermatopatias/sangue , Dermatopatias/tratamento farmacológico , Sede/efeitos dos fármacos , Sede/fisiologiaRESUMO
One of the possibilities for distinct actions of c9,t11- and the t10,c12-conjugated linoleic acid (CLA) isomers may be at the level of metabolism since the conjugated diene structure gives to CLA isomers and their metabolites a distinct pattern of incorporation into the lipid fraction and metabolism. In fact, CLA appears to undergo similar transformations as linoleic acid but with subtle isomer differences, which may account for their activity in lowering linoleic acid metabolites in those tissues rich in neutral lipids where CLA is preferentially incorporated. Furthermore, c9,t11 and t10,c12 isomers are metabolized at a different rate in the peroxisomes, where the shortened metabolite from t10,c12 is formed at a much higher proportion than the metabolite from c9,t11. This may account for the lower accumulation of t10,c12 isomer into cell lipids. CLA isomers may therefore be viewed as a "new" family of polyunsaturated fatty acids (PUFA) producing a distinct range of metabolites using the same enzymatic system as the other (i.e., n-3, n-6 and n-9) PUFA families. It is likely that perturbation of PUFA metabolism by CLA will have an impact on eicosanoid formation and metabolism, closely linked to the biological activities attributed to CLA.
Assuntos
Ácidos Linoleicos Conjugados/classificação , Ácidos Linoleicos Conjugados/metabolismo , Animais , Humanos , Isomerismo , Ácido Linoleico/química , Ácido Linoleico/metabolismo , Ácidos Linoleicos Conjugados/química , Peroxidação de Lipídeos , Peroxissomos/metabolismoRESUMO
BACKGROUND: Extracorporeal membrane oxygenation (ECMO) and cardiac transplantation are recognized to be expensive. METHODS: We performed a cost utility evaluation with a decision model approach, including 75 children with dilated cardiomyopathy. A cohort of patients with end stage heart failure who were offered ECMO bridging was compared with a similar cohort offered only conventional intensive care. Outcome was measured in cost per quality adjusted life year (QALY). RESULTS: Median follow-up was 4.39 years (interquartile range, 1.83-5.74 years), during which 50 children underwent transplantation, 16 had a period of recovery, and 25 died. ECMO bridging was highly effective (hazard ratio, 0.181; 95% confidence interval, 0.067-0.489; p = 0.001) but exceeded conventional criteria for cost-effectiveness. The reference incremental cost-effectiveness ratio (ICER) was pound65,645 per QALY and pound54,284 per life-year gained. Average life expectancy rose from 6.78 to 9.79 years and costs from pound146,398 to pound309,599 per patient with ECMO bridging. The ICER was sensitive to ECMO cost, the long-term transplant survival rate, and quality of life in transplant recipients. CONCLUSIONS: ECMO bridging is effective but expensive. The eligible target population is small, nationally, positively influencing affordability. We strongly support our national policy of mechanical bridge to transplant for suitable children in end stage heart failure. Cost effectiveness could be optimized by: 1) increased availability of organ donors, 2) reduction in mechanical support costs possibly by alternate devices and 3) inclusion of patients most likely to benefit.
Assuntos
Cardiomiopatia Dilatada/cirurgia , Análise Custo-Benefício , Oxigenação por Membrana Extracorpórea/economia , Insuficiência Cardíaca/terapia , Transplante de Coração/fisiologia , Adolescente , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/terapia , Cardiomiopatia Dilatada/complicações , Criança , Pré-Escolar , Custos e Análise de Custo , Cuidados Críticos/economia , Nível de Saúde , Parada Cardíaca/epidemiologia , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/mortalidade , Humanos , Expectativa de Vida/tendências , Cadeias de Markov , Seleção de Pacientes , Qualidade de Vida , Estudos Retrospectivos , Análise de Sobrevida , Reino UnidoRESUMO
OBJECTIVE: The primary aim of this study was to assess the effects of dietary protein intake on energy restriction (ER)-induced changes in body mass and body composition. Clinical markers of metabolic and cardiovascular diseases were also measured. DESIGN: 54 postmenopausal women, age 58 +/- 2 y, body mass index 29.6 +/- 0.8 kg/m(2), were assigned to one of four groups. For 9 weeks, three ER groups ate a 1000 kcal/d lacto-ovo vegetarian basal diet plus 250 kcal/d of either beef (BEEF, n = 14), chicken (CHICKEN, n = 15), or carbohydrate/fat foods (CARB (lacto-ovo), n = 14), while a control group (CON, n = 11) consumed their habitual diets. RESULTS: Energy intake was lower in the ER groups compared to CON (BEEF, 1114 +/- 155 kcal/d, CHO: PRO: FAT, 46:24:30 % of energy intake; CHICKEN, 1098 +/- 203 kcal/d, 51:25:24; CARB 1158 +/- 341 kcal/d, 59:17:24; CON, 1570 +/- 633 kcal/d, 47:20:33), but did not differ among ER groups. For all ER subjects combined, body mass (-6.7 +/- 2.4 kg, 9 %), fat mass (-4.6 +/- 1.9 kg, 13 %), and fat-free mass (-2.1 +/- 1.1 kg, 5 %) decreased. These responses did not differ among the ER groups, except for body mass (CHICKEN -7.9 +/- 2.6 kg(a); BEEF -6.6 +/- 2.7 kg(a,b); CARB -5.6 +/- 1.8 kg(b); CON -1.2 +/- 1.2 kg(c); values with a difference superscript differ, p < 0.05). From PRE (week 0) to POST (week 9), total and LDL cholesterol decreased approximately 12%, with no differences among groups. Triacylglycerol, HDL cholesterol, C-reactive protein (CRP), glucose, insulin, leptin, and adiponectin were not changed over time or differentially affected by diet. CONCLUSIONS: Overweight postmenopausal women can achieve significant weight loss and comparable short-term improvements in body composition and lipid-lipoprotein profile by consuming either a moderate-protein (25% of energy intake) poultry- or beef-containing diet or a lacto-ovo vegetarian protein (17% of energy intake) diet.
Assuntos
Composição Corporal/efeitos dos fármacos , Dieta Redutora , Proteínas Alimentares/administração & dosagem , Metabolismo dos Lipídeos/efeitos dos fármacos , Redução de Peso/fisiologia , Idoso , Animais , Biomarcadores/sangue , Composição Corporal/fisiologia , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Bovinos , Galinhas , Dieta Vegetariana , Ingestão de Energia/fisiologia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Feminino , Nível de Saúde , Humanos , Carne , Pessoa de Meia-Idade , Pós-Menopausa/sangue , Fatores de RiscoRESUMO
OBJECTIVE: Physical age, energy restriction (ER), and weight loss have been reported to suppress indices of innate immunity, which may increase the risk of illness. To evaluate these interactions, we recruited older, postmenopausal women (50 to 80 years) to fill one of the following 9-week ER (1250 kcal/d) groups: beef [n = 14; reported intakes 46% carbohydrate (CHO):24% protein (PRO):30% fat], chicken (n = 15; 51% CHO:25% PRO:24% fat), or CHO (n = 14; 59% CHO:17% PRO:24% fat), or a non-intervention control (n = 11). RESEARCH METHODS AND PROCEDURES: Fasting blood was collected before and after ER to determine leukocyte phenotype, neutrophil oxidative burst capacity, natural killer cell activity, stimulated interleukin-2 and interferon-gamma production, and blood zinc and iron concentrations. RESULTS: No significant effects of ER (8.6% weight loss) or PRO quantity and source were found for the majority of indices of innate immunity. Small but significant (p < 0.05) declines in interleukin-2 production were found in the chicken and CHO groups only; however, the clinical significance of this finding is not known. DISCUSSION: In the present study, 9 weeks of moderate ER did not suppress immunity in postmenopausal women. Also, contrary to our hypothesis, differential zinc and iron intakes did not significantly alter immunity.