RESUMEN
Long-chain polyunsaturated fatty acids (LCPUFA) are important for brain development and functioning and with that, possibly school performance. Several cross-sectional studies have shown significant positive associations between fish consumption, an important source of LCPUFA and school grades in adolescents. The effect of LCPUFA supplementation on school grades in adolescents has not been investigated yet. The goal of the current study was to investigate (I) the associations between the Omega-3 Index (O3I) at baseline and after 12 months respectively and school grades and (II) the effect of one year krill oil supplementation (source of LCPUFA) on school grades in adolescents with a low O3I at baseline. A double-blind randomised placebo-controlled trial with repeated measurements was executed. Participants received either 400 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day for the first three months in Cohort 1 and the nine months thereafter 800 mg EPA + DHA per day, Cohort 2 started immediately with 800 mg EPA + DHA per day,or a placebo. The O3I was monitored with a finger prick at baseline, three, six and twelve months. Subject grades for English, Dutch and math were collected, a standardised mathematics test was executed at baseline and at 12 months. Data was analysed with (I) explorative linear regressions to investigate associations at baseline and follow-up and (II) mixed model analyses separately for each of the subject grades and the standardised mathematics test to investigate the effect of supplementation after 12 months. The krill oil group had a small significant increase in the mean O3I at all time points. However, very few participants achieved the intended target O3I range of 8-11%. At baseline a significant association between baseline O3I and English grade was show, additionally a trend for an association with Dutch grade was shown. After 12 months no significant associations were found. Additionally, there was no significant effect of krill oil supplementation on subject grades or standardised mathematics test score. In this study, no significant effect of krill oil supplementation on subject grades or standardised mathematics test performance was found. However, as many participants dropped out and/or were non-adherent, results should be interpreted with caution.
Asunto(s)
Euphausiacea , Ácidos Grasos Omega-3 , Animales , Suplementos Dietéticos , Estudios Transversales , Ácidos Grasos Omega-3/farmacología , Ácido Eicosapentaenoico , Ácidos Docosahexaenoicos/farmacología , Ácidos Grasos , Método Doble CiegoRESUMEN
The detection of 2-chloroethanol in foods generally follows an assumption that the pesticide ethylene oxide has been used at some stage in the supply chain. In this situation the Pesticide Residues in Food Regulation (EC) 396/2005 requires 2-chloroethanol to be assessed as if equivalent to ethylene oxide, which has been classified as a genotoxic carcinogen. This review investigated whether this is an appropriate risk assessment approach for 2-chloroethanol. This involved an assessment of existing genotoxicity and carcinogenicity data, application of Structure Activity Based Read Across for carcinogenicity assessment, biological reactivity in the ToxTracker assay and micronuclei formation in HepaRG cells. Although we identified there is an absence of a standard oral bioassay for 2-chloroethanol, carcinogenicity weight-of-evidence assessment along with data on relevant structural analogues do not show evidence for carcinogenicity for 2-chloroethanol. The absence of genotoxicity was demonstrated for 2-chloroethanol and suitable analogues. In contrast, ethylene oxide showed reactivity towards markers indicative of direct DNA damage which is consistent with what is known about its mode-of-action. These data facilitate the understanding of 2-chloroethanol and given that it is not a genotoxic carcinogen suggest it must be assessed relative to non-cancer endpoints and a health protective Reference Dose should be established on that basis.
Asunto(s)
Óxido de Etileno , Residuos de Plaguicidas , Pruebas de Carcinogenicidad , Carcinógenos/toxicidad , Daño del ADN , Etilenclorhidrina , Técnicas In Vitro , Pruebas de Mutagenicidad , Relación Estructura-ActividadRESUMEN
Long-chain polyunsaturated fatty acids (LCPUFA) are important for brain development and function, maybe especially during adolescence. Observational studies have demonstrated an association between fish consumption (a source of LCPUFA) and cognition in adolescents, but intervention trials are lacking. The goal of the current study was to investigate the effect of one year of krill oil (a source of LCPUFA) supplementation on the cognitive performance of adolescents with a low Omega-3 Index (O3I ≤ 5%). A double-blind, randomized, and placebo-controlled supplementation trial with repeated measurements (baseline (T0), three months (T1), six months (T2), and 12 months (T3)) in adolescents (267 randomized) was executed. Participants were randomized to 400 mg eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) per day in Cohort I or placebo and 800 mg EPA + DHA per day in Cohort II or placebo. O3I was monitored by a finger prick at all time points. At T0, T2, and T3, participants executed a neurocognitive test battery. Covariate corrected mixed models were run with either condition (krill or placebo) or O3I as predictors. Krill oil supplementation led to a small but significant increase in mean O3I, but few participants increased to the intended O3I range (8-11%). There was no significant effect of supplementation on the neurocognitive tests, nor a relationship between O3I and neurocognitive test scores. The increase in O3I was small in most participants, probably due to non-compliance. Possibly the increase in O3I was too small to demonstrate an effect. More research on the influence of LCPUFAs on cognition in adolescents is needed.
Asunto(s)
Cognición/efectos de los fármacos , Grasas Insaturadas en la Dieta/farmacología , Suplementos Dietéticos , Euphausiacea , Adolescente , Animales , Grasas Insaturadas en la Dieta/administración & dosificación , Método Doble Ciego , Femenino , Humanos , Masculino , Países Bajos , Pruebas Neuropsicológicas , Cooperación del PacienteRESUMEN
Szterk et al. (Food Chemistry 243 (2018) 403-409) have recently analyzed the content of menaquinone-7 (MK-7) in eight dietary supplements. The authors concluded that five out of eight were below the declared content. For all samples, the authors used tetrahydrofuran (THF) to extract MK-7 prior to analysis. Two of the tested products that were below the declared content were microencapsulated MK-7 which had a coating with limited solubility in THF. By dissolving the coating with water and ethanol prior to extraction with ethyl acetate, all MK-7 will be made accessible prior to analysis by HPLC. We have repeated the analysis of the two microencapsulated products that Szterk et al. claimed were below the declared content, and have shown they contain 102% and 105% of the label claim. Since Szterk et al. have used a solvent that does not dissolve the coating on microencapsulated MK-7, their conclusion is not justified and is thus misleading.
Asunto(s)
Suplementos Dietéticos/análisis , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Activation of EGF-R and PDGF-R triggers autophosphorylation and the recruitment of Eps15 and Hrs. These two endosomal proteins are important for specific receptor sorting. Hrs is recruiting ubiquitinated receptors to early endosomes to further facilitate degradation through the ESCRT complex. Upon receptor activation Hrs becomes phosphorylated and is relocated to the cytosol, important for receptor degradation. In this work we have studied the endosomal binding dynamics of Eps15 and Hrs upon EGF-R and PDGF-R stimulation. By analysing the fluorescence intensity on single endosomes after ligand stimulation we measured a time-specific decrease in the endosomal fluorescence level of Eps15-GFP and Hrs-YFP. Through FRAP experiments we could further register a specific change in the endosomal-membrane to cytosol binding properties of Eps15-GFP and Hrs-YFP. This specific change in membrane fractions proved to be a redistribution of the immobile fraction, which was not shown for the phosphorylation deficient mutants. We here describe a mechanism that can explain the previously observed relocation of Hrs from the endosomes to cytosol after EGF stimulation and show that Eps15 follows a similar mechanism. Moreover, this specific redistribution of the endosomal protein binding dynamics proved to be of major importance for receptor degradation.
Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Complejos de Clasificación Endosomal Requeridos para el Transporte/metabolismo , Endosomas/metabolismo , Fosfoproteínas/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Línea Celular , Fibroblastos/metabolismo , Humanos , Inmunoprecipitación , Cinética , Microscopía ConfocalRESUMEN
Vascular endothelial cells present luminal chemokines that arrest rolling leukocytes by activating integrins. It appears that several chemokines must form higher-order oligomers to elicit proper in vivo effects, as mutants restricted to forming dimers have lost the ability to recruit leukocytes to sites of inflammation. Here, we show for the first time that the chemokine RANTES/CCL5 binds to the surface of human endothelial cells in a regular filamentous pattern. Furthermore, the filaments bound to the surface in a heparan sulfate-dependent manner. By electron microscopy we observed labeling for RANTES on membrane projections as well as on the remaining plasma membrane. Mutant constructs of RANTES restricted either in binding to heparin, or in forming dimers or tetramers, appeared either in a granular, non-filamentous pattern or were not detectable on the cell surface. The RANTES filaments were also present after exposure to flow, suggesting that they can be present in vivo. Taken together with the lacking in vivo or in vitro effects of RANTES mutants, we suggest that the filamentous structures of RANTES may be of physiological importance in leukocyte recruitment.
Asunto(s)
Biopolímeros/metabolismo , Quimiocina CCL5/metabolismo , Endotelio Vascular/metabolismo , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Heparitina Sulfato/farmacología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Interferón gamma/farmacología , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Unlike cytarabine, cellular entry of Elacytarabine, the elaidic acid ester derivative of cytarabine, is independent of the human equilibrative nucleoside transporter 1 (hENT1). This phase II study tested whether the hENT1 blast expression level can be used as a predictive marker for cytarabine response and if the efficacy of elacytarabine is independent of hENT1 expression. A total of 51 patients with acute myeloid leukemia (AML) induction failure were given elacytarabine-idarubicin as a second induction course. The hENT1 expression level was analyzed prior to first induction and/or prior to treatment with elacytarabine. The overall response rate (ORR) was 41% and the safety profile was manageable. There is a trend suggesting that hENT1 expression influences response to cytarabine, but not sufficient to support it as a biomarker for guiding treatment. Further, we conclude that the activity of elacytarabine is not significantly predicted by the hENT1 expression level.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Tranportador Equilibrativo 1 de Nucleósido/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Médula Ósea/patología , Citarabina/administración & dosificación , Citarabina/análogos & derivados , Tranportador Equilibrativo 1 de Nucleósido/genética , Femenino , Expresión Génica , Trasplante de Células Madre Hematopoyéticas , Humanos , Idarrubicina/administración & dosificación , Quimioterapia de Inducción , Leucemia Mieloide Aguda/mortalidad , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto JovenRESUMEN
Elacytarabine is a novel cytotoxic nucleoside analogue, independent of nucleoside transporters (e.g. human Equilibrative Nucleoside Transporter 1 [hENT1]) for cell uptake, and mechanisms of action similar to those of cytarabine. This Phase II study assessed the efficacy and safety of elacytarabine in patients with advanced stage acute myeloid leukaemia (AML). Patients received 2000 mg/m(2) per d continuously i.v. during days 1-5 every 3 weeks. Patients were matched by six risk factors with historical controls; remission rate (assessed after 1 or 2 cycles) and 6-month survival were compared. Sixty-one patients, median age 58 years, were enrolled; 52% had five or six risk factors. The remission rate was 18% (95% confidence interval: 9-30%) vs. 4% in controls (P < 0·0001), 6-month survival rate was 43%, median overall survival was 5·3 months (vs. 1·5 months); 10 patients (16%) were referred for stem cell transplantation after treatment. Side effects were predictable and manageable. The most common grade 3/4 non-haematological adverse events were febrile neutropenia, hypokalemia, fatigue, hyponatraemia, dyspnoea and pyrexia. Thirty-day all-cause mortality, after start of treatment, was 13% vs. 25% in controls. Elacytarabine has monotherapy activity in patients with advanced AML. This study provides proof-of-concept that lipid esterification of nucleoside analogues is clinically relevant.
Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Citarabina/análogos & derivados , Leucemia Mieloide Aguda/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Antimetabolitos Antineoplásicos/efectos adversos , Citarabina/administración & dosificación , Citarabina/efectos adversos , Femenino , Humanos , Infusiones Intravenosas , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , Derivación y Consulta , Inducción de Remisión , Factores de Riesgo , Trasplante de Células Madre , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
Organelles in the endocytic pathway interact and communicate through the crucial mechanisms of fusion and fission. However, any specific link between fusion and fission has not yet been determined. To study the endosomal interactions with high spatial and temporal resolution, we enlarged the endosomes by two mechanistically different methods: by expression of the MHC-class-II-associated chaperone invariant chain (Ii; or CD74) or Rab5, both of which increased the fusion rate of early endosomes and resulted in enlarged endosomes. Fast homotypic fusions were studied, and immediately after the fusion a highly active and specific tubule formation and fission was observed. These explosive tubule formations following fusion seemed to be a direct effect of fusion. The tubule formations were dependent on microtubule interactions, and specifically controlled by Kif16b and dynein. Our results show that fusion of endosomes is a rapid process that destabilizes the membrane and instantly induces molecular-motor-driven tubule formation and fission.
Asunto(s)
Dineínas/metabolismo , Endosomas/metabolismo , Cinesinas/metabolismo , Fusión de Membrana , Microtúbulos/metabolismo , Proteínas Motoras Moleculares/metabolismo , Animales , Línea Celular , Perros , Endocitosis , Humanos , Proteínas de Unión al GTP rab5/metabolismoRESUMEN
Early endosomal antigen 1 (EEA1) is a cytosolic protein that specifically binds to early endosomal membranes where it has a crucial role in the tethering process leading to homotypic endosome fusion. Green fluorescent protein-tagged EEA1 (EEA1-GFP) was bound to the endosomal membrane throughout the cell cycle, and measurements using fluorescent recovery after photobleaching showed two fractions: one rapidly exchanging with the cytosolic pool, and the other with a long half-life. The exchange consists of a release and binding process, and we have separated these two by using GFP and photoactivable GFP. The release rate was identical to the exchange rate, showing that the dissociation characteristics determine the cycling of this molecule. During mitosis, we found that the dissociation rate was markedly accelerated and, in addition, the long-lived fraction was markedly reduced. This indicates that a fusion arrest in mitosis is not the result of EEA1 not binding to early endosomes, but rather due to the marked shift in membrane-binding characteristics. This might be a general mechanism to fine-tune and control tethering and fusion of early endosomes.
Asunto(s)
Ciclo Celular/fisiología , Endosomas/metabolismo , Proteínas de la Membrana/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animales , Antígenos de Diferenciación de Linfocitos B/metabolismo , Membrana Celular/metabolismo , Citosol/metabolismo , Perros , Recuperación de Fluorescencia tras Fotoblanqueo , Antígenos de Histocompatibilidad Clase II/metabolismo , Interfase , Cinética , Proteínas de la Membrana/química , Metafase , Fosfatos de Fosfatidilinositol/metabolismo , Estructura Terciaria de Proteína , Proteínas Recombinantes de Fusión/metabolismo , Proteínas de Transporte Vesicular/química , Proteínas de Unión al GTP rab5/metabolismoRESUMEN
OBJECTIVE: To develop and validate a simple patient questionnaire for the detection of overactive bladder (OAB). DESIGN: An open, non-randomized multicentre study. SETTING: A pilot study (n = 133) was conducted to bring forward five questions from initially 14 questions, for detection of OAB. These five questions were subject to further validation in the main study (n =520). SUBJECTS: 531 adults responding to a newspaper advertisement regarding symptoms of OAB and patients seeing a physician for other reasons were attending 28 general practitioners. MAIN OUTCOME MEASURES: Agreement rate, sensitivity, and specificity. RESULTS: The agreement rate between the patients' own diagnosis based on the patient questionnaire, and the physicians' diagnosis based on medical history, urine analysis, and micturition chart, was 0.78 (kappa =0.89). Sensitivity and specificity were 0.98 and 0.90, respectively. CONCLUSION: The validated questionnaire may become a useful tool to decide whether a patient has overactive bladder. The questionnaire corresponds well with the physicians' diagnosis.