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1.
Food Res Int ; 148: 110575, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34507725

RESUMEN

Consumption of fresh and minimally processed foods such as seeds as a part of a healthy diet is a trend. Unfortunately, fat-rich seeds are often contaminated with pathogenic microorganisms and face frequent product recalls. Electron beams have been applied as a microbial decontamination measure for decades. Conventionally high energy electron beams (HEEB) are being used, whereas low energy electron beams (LEEB, <300 keV) have only recently been introduced to the food industry and more studies are needed. Electron beam treatment has several advantages over other decontamination technologies. The treatment is non-thermal, chemical-free, water-free, and does not use radioactive substances. The effect of electron beams on the sensory and chemical properties of seeds has not been widely studied. This study assessed LEEB and HEEB treated pumpkin and flax seeds immediately after treatments, and after three months of storage. The seeds' sensory profiles were altered after both treatments when compared with non-treated samples, with a higher dose leading to a greater level of alteration. However, the sensory profile of LEEB treated seeds was similar to the non-treated seeds whereas HEEB treated seeds differed from both. The storage period of three months further increased the observed differences between the samples. LEEB and HEEB treatments seemed to cause lipid degradation as the content of volatile aldehydes was increased. This effect was more profound in HEEB treated samples. The data presented in this study shows that LEEB as a microbial reduction solution has great potential to preserve the chemical and sensory properties of nutritious seeds.


Asunto(s)
Cucurbita , Electrones , Comida Rápida , Semillas
2.
Hum Mov Sci ; 54: 347-353, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28688301

RESUMEN

This study examined effects of player roles on interpersonal patterns of coordination that sustain decision-making in 1-vs-1 sub-phases of football in different field locations near the goal (left-, middle- and right zone). Participants were fifteen U-16yrs players from a local competitive amateur team. To measure interpersonal patterns of coordination in the 1-vs-1 dyads we recorded: (i) the relative distance value between each attacker and defender to the centre of the goal, and (ii), the relative angle between the centre of the goal, each defender and attacker. Results revealed how variations in field locations near the goal (left-, middle- and right-zones) constrained the relative distance and relative angle values that emerged between them and the goal. It reveals that relative position of the goal is a key informational variable that sustained participants' behaviours for dribbling and shooting. Higher values of relative distance and angle were observed in the middle zone, compared to other zones. Players' roles also constitute a constraint on the interpersonal coordination for dribbling and shooting. Additionally, it seems that players' foot preference constrains the dynamics of interpersonal patterns of coordination between participants, especially in left and right zones. The findings suggest that to increase participants' opportunities for action, coaches should account with field positions, players' roles and preference foot.


Asunto(s)
Rendimiento Atlético/fisiología , Fútbol/fisiología , Adolescente , Atletas , Conducta Competitiva/fisiología , Toma de Decisiones/fisiología , Lateralidad Funcional/fisiología , Humanos , Relaciones Interpersonales , Masculino , Destreza Motora/fisiología
3.
Geobiology ; 15(3): 366-384, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28378894

RESUMEN

Geological records of atmospheric oxygen suggest that pO2 was less than 0.001% of present atmospheric levels (PAL) during the Archean, increasing abruptly to a Proterozoic value between 0.1% and 10% PAL, and rising quickly to modern levels in the Phanerozoic. Using a simple model of the biogeochemical cycles of carbon, oxygen, sulfur, hydrogen, iron, and phosphorous, we demonstrate that there are three stable states for atmospheric oxygen, roughly corresponding to levels observed in the geological record. These stable states arise from a series of specific positive and negative feedbacks, requiring a large geochemical perturbation to the redox state to transition from one to another. In particular, we show that a very low oxygen level in the Archean (i.e., 10-7 PAL) is consistent with the presence of oxygenic photosynthesis and a robust organic carbon cycle. We show that the Snowball Earth glaciations, which immediately precede both transitions, provide an appropriate transient increase in atmospheric oxygen to drive the atmosphere either from its Archean state to its Proterozoic state, or from its Proterozoic state to its Phanerozoic state. This hypothesis provides a mechanistic explanation for the apparent synchronicity of the Proterozoic Snowball Earth events with both the Great Oxidation Event, and the Neoproterozoic oxidation.


Asunto(s)
Atmósfera/química , Fenómenos Geológicos , Oxígeno/análisis
4.
Geobiology ; 13(5): 454-61, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25923883

RESUMEN

Lake Matano, Indonesia, is a stratified anoxic lake with iron-rich waters that has been used as an analogue for the Archean and early Proterozoic oceans. Past studies of Lake Matano report large amounts of methane production, with as much as 80% of primary production degraded via methanogenesis. Low δ(13)C values of DIC in the lake are difficult to reconcile with this notion, as fractionation during methanogenesis produces isotopically heavy CO2. To help reconcile these observations, we develop a box model of the carbon cycle in ferruginous Lake Matano, Indonesia, that satisfies the constraints of CH4 and DIC isotopic profiles, sediment composition, and alkalinity. We estimate methane fluxes smaller than originally proposed, with about 9% of organic carbon export to the deep waters degraded via methanogenesis. In addition, despite the abundance of Fe within the waters, anoxic ferric iron respiration of organic matter degrades <3% of organic carbon export, leaving methanogenesis as the largest contributor to anaerobic organic matter remineralization, while indicating a relatively minor role for iron as an electron acceptor. As the majority of carbon exported is buried in the sediments, we suggest that the role of methane in the Archean and early Proterozoic oceans is less significant than presumed in other studies.


Asunto(s)
Ciclo del Carbono , Lagos , Anaerobiosis , Carbono/metabolismo , Dióxido de Carbono/metabolismo , Indonesia , Marcaje Isotópico , Metano/metabolismo
5.
Behav Brain Res ; 238: 69-78, 2013 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-23089646

RESUMEN

The LRRTM family proteins have been shown to act as synaptogenic cell adhesion molecules via interaction with presynaptic neurexins and are associated with neuropsychiatric disorders. LRRTM1-knockout mice have subtle morphological deficits in excitatory hippocampal synapses and were suggested to have impaired cognitive function. Here we report that LRRTM1-knockout mice exhibit an extraordinary phenotype of avoiding small enclosures. In the light-dark box, the knockout mice escape to dark through a standard opening as quickly as wild-type littermates but avoid escaping through a small doorway. While all wild-type mice spontaneously enter a small tube, most knockout mice do not. This apparent aversion to enter narrow space may explain other abnormalities such as increased time in open arms in the elevated plus maze and less visits through a tunnel in the IntelliCage. Moreover, LRRTM1-knockout mice show increased social interaction, reduced nest building and MK801-induced locomotion, and slower swim speed but normal water maze learning. Since LRRTM1 is predominantly expressed in thalamus, hippocampus and limbic cortex, specific synaptic defects in those areas presumably cause these behavioural abnormalities.


Asunto(s)
Conducta Animal/fisiología , Actividad Motora/fisiología , Moléculas de Adhesión de Célula Nerviosa/genética , Trastornos Fóbicos/genética , Animales , Modelos Animales de Enfermedad , Aprendizaje por Laberinto/fisiología , Proteínas de la Membrana , Ratones , Ratones Noqueados , Proteínas del Tejido Nervioso , Moléculas de Adhesión de Célula Nerviosa/metabolismo , Fenotipo , Trastornos Fóbicos/metabolismo , Conducta Social , Natación/fisiología
6.
Diabetologia ; 55(12): 3273-83, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22983635

RESUMEN

AIMS/HYPOTHESIS: Virally induced inflammatory responses, beta cell destruction and release of beta cell autoantigens may lead to autoimmune reactions culminating in type 1 diabetes. Therefore, viral capability to induce beta cell death and the nature of virus-induced immune responses are among key determinants of diabetogenic viruses. We hypothesised that enterovirus infection induces a specific gene expression pattern that results in islet destruction and that such a host response pattern is not shared among all enterovirus infections but varies between virus strains. METHODS: The changes in global gene expression and secreted cytokine profiles induced by lytic or benign enterovirus infections were studied in primary human pancreatic islet using DNA microarrays and viral strains either isolated at the clinical onset of type 1 diabetes or capable of causing a diabetes-like condition in mice. RESULTS: The expression of pro-inflammatory cytokine genes (IL-1-α, IL-1-ß and TNF-α) that also mediate cytokine-induced beta cell dysfunction correlated with the lytic potential of a virus. Temporally increasing gene expression levels of double-stranded RNA recognition receptors, antiviral molecules, cytokines and chemokines were detected for all studied virus strains. Lytic coxsackievirus B5 (CBV-5)-DS infection also downregulated genes involved in glycolysis and insulin secretion. CONCLUSIONS/INTERPRETATION: The results suggest a distinct, virus-strain-specific, gene expression pattern leading to pancreatic islet destruction and pro-inflammatory effects after enterovirus infection. However, neither viral replication nor cytotoxic cytokine production alone are sufficient to induce necrotic cell death. More likely the combined effect of these and possibly cellular energy depletion lie behind the enterovirus-induced necrosis of islets.


Asunto(s)
Efecto Citopatogénico Viral/inmunología , Diabetes Mellitus Tipo 1/patología , Enterovirus Humano B/inmunología , Infecciones por Enterovirus/patología , Animales , Células Cultivadas , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/virología , Enterovirus Humano B/patogenicidad , Infecciones por Enterovirus/inmunología , Infecciones por Enterovirus/virología , Femenino , Regulación de la Expresión Génica , Humanos , Inmunidad Innata , Inmunohistoquímica , Inflamación , Interleucina-1alfa/inmunología , Interleucina-1beta/inmunología , Masculino , Ratones , Persona de Mediana Edad , Necrosis , Factor de Necrosis Tumoral alfa/inmunología
7.
Transl Psychiatry ; 1: e57, 2011 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-22832349

RESUMEN

Mild cognitive impairment (MCI) is considered as a transition phase between normal aging and Alzheimer's disease (AD). MCI confers an increased risk of developing AD, although the state is heterogeneous with several possible outcomes, including even improvement back to normal cognition. We sought to determine the serum metabolomic profiles associated with progression to and diagnosis of AD in a prospective study. At the baseline assessment, the subjects enrolled in the study were classified into three diagnostic groups: healthy controls (n=46), MCI (n=143) and AD (n=47). Among the MCI subjects, 52 progressed to AD in the follow-up. Comprehensive metabolomics approach was applied to analyze baseline serum samples and to associate the metabolite profiles with the diagnosis at baseline and in the follow-up. At baseline, AD patients were characterized by diminished ether phospholipids, phosphatidylcholines, sphingomyelins and sterols. A molecular signature comprising three metabolites was identified, which was predictive of progression to AD in the follow-up. The major contributor to the predictive model was 2,4-dihydroxybutanoic acid, which was upregulated in AD progressors (P=0.0048), indicating potential involvement of hypoxia in the early AD pathogenesis. This was supported by the pathway analysis of metabolomics data, which identified upregulation of pentose phosphate pathway in patients who later progressed to AD. Together, our findings primarily implicate hypoxia, oxidative stress, as well as membrane lipid remodeling in progression to AD. Establishment of pathogenic relevance of predictive biomarkers such as ours may not only facilitate early diagnosis, but may also help identify new therapeutic avenues.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/metabolismo , Progresión de la Enfermedad , Vía de Pentosa Fosfato/fisiología , Anciano , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/patología , Biomarcadores/sangre , Biomarcadores/metabolismo , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/patología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Metaboloma/fisiología , Valor Predictivo de las Pruebas
8.
Artículo en Inglés | MEDLINE | ID: mdl-20206485

RESUMEN

The effects of canola-type rapeseed oil (RSO) on serum lipids, plasma fibrinogen, lipid oxidation and fatty acids were studied in three groups of subjects, two of which had not been consuming fish in their habitual diets. Forty-two volunteers (35 women, 7 men, 16-62 years) replaced fat with RSO for 6 weeks in a parallel design. The average cholesterol and fibrinogen concentrations were 5.0 mmol/l and 2.6 g/l, respectively. The intake of alpha-linolenic acid (alpha-LLA) was doubled. Efficient competitive inhibition by alpha-LLA was seen as a decrease in long-chain (LC) n-6 PUFA at 3 weeks. Elevated fibrinogen (2.6-3.9 g/l) decreased by 0.95 g/l at 6 weeks. Docosahexaenoic acid (22:6n-3) in plasma phospholipids increased at low fibrinogen levels only. The associations and changes in plasma C18 and LC PUFA followed the competitive and metabolic principles of the body, and especially in the case of n-3 PUFA according to the recycling pathway.


Asunto(s)
Ácidos Grasos Monoinsaturados/administración & dosificación , Ácidos Grasos Omega-6/sangre , Fibrinógeno/análisis , Ácido alfa-Linolénico/efectos adversos , Adolescente , Adulto , Femenino , Fibrinógeno/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Fosfolípidos/sangre , Aceite de Brassica napus , Factores de Tiempo , Ácido alfa-Linolénico/administración & dosificación
9.
Nutr Metab Cardiovasc Dis ; 20(4): 249-57, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-19553094

RESUMEN

BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue. METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways. CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.


Asunto(s)
Carbohidratos de la Dieta/farmacología , Síndrome Metabólico/sangre , Síndrome Metabólico/dietoterapia , Tejido Adiposo/metabolismo , Tejido Adiposo/fisiología , Aminoácidos de Cadena Ramificada/sangre , Vías Biosintéticas , Cromatografía Líquida de Alta Presión , Dieta , Ingestión de Alimentos , Ácidos Grasos/sangre , Expresión Génica/efectos de los fármacos , Expresión Génica/genética , Índice Glucémico , Humanos , Lípidos/sangre , Síndrome Metabólico/genética , Metabolómica , Grosor de los Pliegues Cutáneos , Espectrometría de Masa por Ionización de Electrospray , Resultado del Tratamiento
10.
Diabetologia ; 52(12): 2612-5, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19669729

RESUMEN

AIMS/HYPOTHESIS: Ceramides and IL-6 have a role in immune-inflammatory responses and cardiovascular diseases, and are suggested to be involved in insulin and glucose metabolism. We sought to assess the associations of circulating levels of IL-6, TNF-alpha and high-sensitivity C reactive protein (hsCRP), which are inflammatory markers related to insulin resistance (IR), with the plasma lipid metabolites ceramides and diacylglycerols (DAG) in patients with CHD. METHODS: Cross-sectional analyses were carried out on data from 33 patients with CHD. Serum levels of the inflammatory markers and plasma lipid metabolites (lipidomics approach performed by ultra-performance liquid chromatography coupled to electrospray ionisation MS) were measured at the same time point as insulin resistance (IR) (HOMA-IR index). RESULTS: Serum circulating levels of IL-6 were strongly correlated with plasma ceramide concentrations (r = 0.59, p < 0.001). Adjustments for serum TNF-alpha or hsCRP levels, smoking, BMI, age, sex or HOMA-IR did not change the results (p < 0.001). After adjustments for the effect of serum inflammatory markers (TNF-alpha or hsCRP), HOMA-IR and BMI the correlation between plasma DAG and serum IL-6 (r = 0.33) was also significant (p < 0.03). In a linear regression model, circulating levels of both ceramides and TNF-alpha had a significant independent influence on circulating levels of IL-6, altogether accounting for 41% of its variation (p < 0.001). CONCLUSIONS/INTERPRETATION: Our results strongly suggest that the link between ceramides, IR and inflammation is related to the inflammatory marker IL-6. Ceramides may contribute to the induction of inflammation involved in IR states that frequently coexist with CHD.


Asunto(s)
Ceramidas/sangre , Enfermedad Coronaria/sangre , Inflamación/sangre , Interleucina-6/sangre , Proteína C-Reactiva/metabolismo , Enfermedad Coronaria/fisiopatología , Estudios Transversales , Humanos , Isquemia/sangre , Isquemia/fisiopatología , Lípidos/sangre , Infarto del Miocardio/sangre , Infarto del Miocardio/fisiopatología , Factor de Necrosis Tumoral alfa/sangre
11.
Int J Pharm ; 254(2): 155-66, 2003 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-12623191

RESUMEN

The aim of the present work was to study the solubility and phase behaviour of the beta-sitosterol-cholesterol mixed crystals in the presence and absence of water. Cholesterol, beta-sitosterol and 3:1, 1:1 and 1:3 mixtures of these were co-precipitated from acetone and acetone-water solutions. Precipitated crystals were analysed using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), optical microscopy and Karl-Fischer titrimetry. The quantification of the sterols in solutions was preformed using GC-MS. The solubility of the sterols was mutually limiting. In the aqueous system, the solubility of both the sterols were significantly lower than in the absence of water, but the decrease in the solubility was considerably greater with the more hydrophobic beta-sitosterol. In the aqueous system, the total sterol solubility decreased with the increasing proportion of beta-sitosterol. The formation of new crystal structures, solid solutions of cholesterol and beta-sitosterol, was observed in non-aqueous as well as in aqueous environments except with the lowest cholesterol proportion in the system, in which case mixed crystals with eutectic behaviour were formed.


Asunto(s)
Colesterol/química , Sitoesteroles/química , Acetona/química , Rastreo Diferencial de Calorimetría , Precipitación Química , Cristalización , Cromatografía de Gases y Espectrometría de Masas , Solubilidad , Soluciones , Volumetría , Agua/química , Difracción de Rayos X
12.
Nutr Metab Cardiovasc Dis ; 11(3): 158-67, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11590991

RESUMEN

BACKGROUND AND AIM: Recent clinical studies have demonstrated that plant sterols moderately lower serum cholesterol levels in patients with mild hypercholesterolemia. Furthermore, there is evidence suggesting that mineral nutrients, such as calcium and magnesium, may also decrease serum cholesterol concentrations. In this study, we tested the hypothesis that supplementation with mineral nutrients may enhance the cholesterol-lowering effect of plant sterols in obese Zucker rats. Furthermore, we compared the lipid-lowering effects of monovalent sodium and potassium cations with those of divalent calcium and magnesium cations. METHODS AND RESULTS: A Western-type high-fat/high-cholesterol diet increased serum cholesterol by 175% and liver cholesterol by 65% in comparison with a low-fat/low-cholesterol control diet. On the contrary, the high-fat/high-cholesterol diet decreased intestinal cholesterol absorption, as assessed by means of serum campesterol-, sitosterol-, and sitostanol-to-cholesterol ratios, thus indicating that it was under negative feedback regulation. Supplementation of the high-fat/high-cholesterol diet with plant sterols or mineral nutrients partially prevented the diet-induced increased in serum cholesterol and, when given concurrently, their cholesterol-lowering effect was enhanced. Their combination also effectively prevented the diet-induced increase in liver cholesterol concentration, and had beneficial effects on liver and myocardial hypertrophy, and the development of obesity. These beneficial effects were at least partially mediated by an enhanced blockade of intestinal cholesterol absorption. Interestingly, only divalent cations enhanced the cholesterol-lowering effect of plant sterols, thus supporting the idea that the lipid-lowering effect of divalent cations is related to the formation of insoluble and inabsorbable calcium and magnesium chelates with fatty acids. CONCLUSIONS: Our findings indicate that the cholesterol-lowering effect of plant sterols is enhanced by the co-administration of divalent calcium and magnesium cations but not by monovalent sodium and potassium cations.


Asunto(s)
Calcio de la Dieta/uso terapéutico , Colesterol/sangre , Magnesio/uso terapéutico , Obesidad/dietoterapia , Fitosteroles/uso terapéutico , Análisis de Varianza , Animales , Calcio de la Dieta/sangre , Calcio de la Dieta/orina , Electrólitos/orina , Femenino , Metabolismo de los Lípidos , Magnesio/sangre , Obesidad/sangre , Potasio en la Dieta/uso terapéutico , Potasio en la Dieta/orina , Ratas , Ratas Zucker , Sodio en la Dieta/uso terapéutico , Sodio en la Dieta/orina
13.
Eur J Nutr ; 40(2): 66-73, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11518201

RESUMEN

BACKGROUND: Plant sterols have been shown to reduce serum lipid concentrations. The effectiveness is highly dependent on the physical state of the plant sterols. By means of a new crystallizing method, plant sterols can be added into dietary fats and oils homogeneously. In this fat ingredient, plant sterols are in a microcrystalline form. AIMS OF THE STUDY: We investigated the cholesterol-lowering effect and possible side effects of vegetable oil-based spreads fortified with two different doses of microcrystalline plant sterols. METHODS: This double-blind randomized, placebo-controlled study consisted of a 6-wk run-in and a 6-month experimental period. During the run-in period, all 155 hypercholesterolemic subjects received rapeseed oil-based control spread. In the beginning of the experimental period subjects were randomly assigned into one of three experimental groups. The control group continued to use control spread, and the two test groups used spreads with added plant sterols of either 1.5 g/d or 3.0 g/d. The subjects consumed test spreads as a part of their normal diet without any restrictions in lifestyle and diet. RESULTS: Plasma total- and LDL-cholesterol concentrations were significantly reduced by 7.5-11.6% (0.46-0.62 mmol/1) in groups consuming margarine enriched with free plant sterols, compared with the control group. The effects were similar between the two groups consuming either 1.5g or 3.0 g plant sterols per day. No effect on HDL-cholesterol or triacylglycerol concentrations occurred. The test spreads did not induce any adverse effects in blood clinical chemistry, hematology or decreases in serum concentrations of lipid soluble vitamins. CONCLUSIONS: Microcrystalline plant sterols are effective in lowering serum total- and LDL-cholesterol concentrations without obvious side effects. The daily dose of 1.5 g plant sterols is enough to reach the maximum effect.


Asunto(s)
Colesterol/sangre , Hipercolesterolemia/dietoterapia , Fitosteroles/administración & dosificación , Adulto , Carotenoides/sangre , Celulosa/administración & dosificación , LDL-Colesterol/sangre , LDL-Colesterol/efectos de los fármacos , LDL-Colesterol/metabolismo , Método Doble Ciego , Excipientes , Femenino , Alimentos Fortificados , Humanos , Hipercolesterolemia/metabolismo , Absorción Intestinal , Cinética , Estudios Longitudinales , Masculino , Margarina , Persona de Mediana Edad , Oxidación-Reducción , Fitosteroles/efectos adversos , Fitosteroles/farmacología , Vitaminas/sangre
14.
J Chromatogr B Biomed Sci Appl ; 754(2): 437-45, 2001 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-11339287

RESUMEN

An HPLC method with evaporative light-scattering detection (ELSD) was optimized and validated for the simultaneous quantitation of cholesteryl esters (CEs), triacylglycerols (TGs), free cholesterol (FC) and phosphatidylcholine (PC) in human plasma. The separation of CEs from TGs, the most variable plasma lipid class, was improved by speeding up the gradient steps and by increasing the re-equilibration time between runs. The calibrations were made at levels of 0.14-14 microg lipid/injection. The intra- and inter-day precision values of the method ranged between 1.9 and 4.5 and 2.3-7.2% (RSD, n=6), respectively, including determinations at two concentration levels. In comparison to other lipid classes, quantitation of PC proved to be equally repeatable despite its lowest detector response. The relative recoveries varied from 97.0 to 110.3%, showing good accuracy of the method. The methodological variation of the lipid classes covered 0.6-3.1% of their total variation in the study population (n=48). The CE/FC ratio showed an even closer relationship with phospholipid linoleic acid (18:2n-6; r=0.65, P<0.001) than with serum cholesterol levels, while eicosapentaenoic acid (20:5n-3) was significantly associated with PC (r=0.41, P<0.01). The CE/FC ratio increased (P<0.01) during soyabean oil substitution and the level of PC increased (P<0.01) during cold-pressed rapeseed oil substitution.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Lípidos/sangre , Ácidos Grasos/análisis , Ácidos Grasos/química , Humanos , Lípidos/análisis , Lípidos/clasificación , Fosfolípidos/análisis , Fosfolípidos/química , Aceites de Plantas/química , Reproducibilidad de los Resultados
15.
Protein Sci ; 10(1): 74-82, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11266596

RESUMEN

Calerythrin, a four-EF-hand calcium-binding protein from Saccharopolyspora erythraea, exists in an equilibrium between ordered and less ordered states with slow exchange kinetics when deprived of Ca(2+) and at low temperatures, as observed by NMR. As the temperature is raised, signal dispersion in NMR spectra reduces, and intensity of near-UV CD bands decreases. Yet far-UV CD spectra indicate only a small decrease in the amount of secondary structure, and SAXS data show that no significant change occurs in the overall size and shape of the protein. Thus, at elevated temperatures, the equilibrium is shifted toward a state with characteristics of a molten globule. The fully structured state is reached by Ca(2+)-titration. Calcium first binds cooperatively to the C-terminal sites 3 and 4 and then to the N-terminal site 1, which is paired with an atypical, nonbinding site 2. EF-hand 2 still folds together with the C-terminal half of the protein, as deduced from the order of appearance of backbone amide cross peaks in the NMR spectra of partially Ca(2+)-saturated states.


Asunto(s)
Proteínas de Unión al Calcio/química , Calcio/metabolismo , Motivos EF Hand , Saccharopolyspora/química , Proteínas Bacterianas , Proteínas de Unión al Calcio/metabolismo , Dicroismo Circular , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Saccharopolyspora/metabolismo , Volumetría
16.
J Biol Chem ; 276(12): 9337-43, 2001 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-11113122

RESUMEN

Levosimendan is an inodilatory drug that mediates its cardiac effect by the calcium sensitization of contractile proteins. The target protein of levosimendan is cardiac troponin C (cTnC). In the current work, we have studied the interaction of levosimendan with Ca(2+)-saturated cTnC by heteronuclear NMR and small angle x-ray scattering. A specific interaction between levosimendan and the Ca(2+)-loaded regulatory domain of recombinant cTnC(C35S) was observed. The changes in the NMR spectra of the N-domain of full-length cTnC(C35S), due to the binding of levosimendan to the primary site, were indicative of a slow conformational exchange. In contrast, no binding of levosimendan to the regulatory domain of cTnC(A-Cys), where all the cysteine residues are mutated to serine, was detected. Moreover, it was shown that levosimendan was in fast exchange on the NMR time scale with a secondary binding site in the C-domain of both cTnC(C35S) and cTnC(A-Cys). The small angle x-ray scattering experiments confirm the binding of levosimendan to Ca(2+)-saturated cTnC but show no domain-domain closure. The experiments were run in the absence of the reducing agent dithiothreitol and the preservative sodium azide (NaN(3)), since we found that levosimendan reacts with these chemicals, commonly used for preparation of NMR protein samples.


Asunto(s)
Calcio/metabolismo , Hidrazonas/metabolismo , Miocardio/metabolismo , Piridazinas/metabolismo , Troponina C/metabolismo , Espectroscopía de Resonancia Magnética , Unión Proteica , Simendán , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
17.
Opt Express ; 8(6): 296-301, 2001 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-19417818

RESUMEN

The macroscopic shapes, rotational states, and scattering parameters of atmosphereless bodies can be deduced from photometric measurements of total brightnesses in different viewing/illumination geometries. The problem is solved with nonlinear optimization techniques; the use of positive definite quantities effectively removes the apparent ill-posedness of the problem. Since the parameters of scattering laws such as the Hapke model cannot be unambiguously determined from photometric data only, we propose a simple empirical scattering model for the purpose. Our methods can obtain convex hull-like shapes even for strongly nonconvex objects; a conception of the major concavities can also be formed.

18.
J Pediatr ; 136(1): 46-52, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10636973

RESUMEN

OBJECTIVE: We evaluated whether replacing a proportion of saturated fat with vegetable oils in the diet of young children increases trans fatty acid intake. STUDY DESIGN: Dietary counseling aimed to reach a dietary fat ratio of unsaturated to saturated fat of 2:1 within a total fat intake of 30% to 35% of energy (E%). Four-day food records of 813 3-year-old children were analyzed, and serum phospholipid fatty acid compositions of 25 randomly selected intervention children and 17 control children were analyzed. RESULTS: trans fatty acid intake of the intervention and control children was small (0.8 E% and 0.6 E%, respectively; P <.001). The relative content of serum phospholipid trans 18:1 was closely similar in intervention and control children (1.0% and 0.9% of all fatty acids, respectively). Trans fatty acid intake and serum trans 18:1 correlated poorly with children's serum cholesterol and HDL cholesterol concentrations and inversely with serum phospholipid arachidonic to linoleic acid ratio (r = -0.373). CONCLUSIONS: Trans fatty acid intake of children in Finland is minimal. Dietary intervention replacing saturated with unsaturated fatty acids is safe because it does not increase trans fatty acid intake or the relative content of trans fatty acids in the serum phospholipid fraction.


Asunto(s)
Colesterol en la Dieta/administración & dosificación , Dieta con Restricción de Grasas , Grasas Insaturadas en la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Ácidos Grasos Insaturados/administración & dosificación , Ácidos Grasos/administración & dosificación , Fosfolípidos/sangre , Ácido Araquidónico/sangre , Arteriosclerosis/prevención & control , Preescolar , Colesterol/sangre , HDL-Colesterol/sangre , Consejo , Grasas Insaturadas en la Dieta/análisis , Ingestión de Energía , Ácidos Grasos/análisis , Ácidos Grasos Insaturados/análisis , Finlandia , Humanos , Isomerismo , Ácido Linoleico/sangre , Registros Médicos , Fosfolípidos/análisis , Aceites de Plantas/administración & dosificación , Estudios Prospectivos , Factores de Riesgo
19.
Neuron ; 22(2): 243-52, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10069331

RESUMEN

Glial cell line-derived neurotrophic factor (GDNF) and a related protein, neurturin (NTN), require a GPI-linked coreceptor, either GFR alpha1 or GFR alpha2, for signaling via the transmembrane Ret tyrosine kinase. We show that mice lacking functional GFR alpha2 coreceptor (Gfra2-/-) are viable and fertile but have dry eyes and grow poorly after weaning, presumably due to malnutrition. While the sympathetic innervation appeared normal, the parasympathetic cholinergic innervation was almost absent in the lacrimal and salivary glands and severely reduced in the small bowel. Neurite outgrowth and trophic effects of NTN at low concentrations were lacking in Gfra2-/- trigeminal neurons in vitro, whereas responses to GDNF were similar between the genotypes. Thus, GFR alpha2 is a physiological NTN receptor, essential for the development of specific postganglionic parasympathetic neurons.


Asunto(s)
Proteínas de Drosophila , Trastornos del Crecimiento/genética , Intestinos/inervación , Mutación/genética , Enfermedades del Sistema Nervioso/genética , Sistema Nervioso Parasimpático , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras/genética , Animales , Animales Recién Nacidos/fisiología , Blefaroptosis/genética , Síndromes de Ojo Seco/genética , Motilidad Gastrointestinal/fisiología , Factor Neurotrófico Derivado de la Línea Celular Glial , Receptores del Factor Neurotrófico Derivado de la Línea Celular Glial , Aparato Lagrimal/inervación , Ratones , Plexo Mientérico/fisiopatología , Factores de Crecimiento Nervioso/metabolismo , Factores de Crecimiento Nervioso/farmacología , Proteínas del Tejido Nervioso/farmacología , Neuritas/efectos de los fármacos , Neuritas/fisiología , Neurturina , Sistema Nervioso Parasimpático/fisiopatología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-ret , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptores de Superficie Celular/metabolismo , Glándulas Salivales/inervación , Ganglio del Trigémino/efectos de los fármacos , Ganglio del Trigémino/fisiología
20.
J Int Med Res ; 26(4): 171-80, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9818783

RESUMEN

An extract from red-wine grape fermentation, ANOX has been developed as a source of red-wine polyphenols, which are thought to inhibit several of the pathogenic pathways that lead to cardiovascular disease. New data indicate that this extract has a significantly greater effect than either red wine or red-wine powder on the inhibition of platelet aggregation in vitro. Based on this data, about 300 - 500 mg of the extract is equivalent to the daily dose of red-wine polyphenols that appears to protect against cardiovascular disease. The possible synergistic effect of red-wine polyphenols with vitamin C, their vasorelaxing activity and their possible role in preventing over-crosslinking of connective tissues (premature ageing) are considered. The extract contains standardized amounts of the whole spectrum of polyphenolic compounds found in red wine and may provide a valuable reference substance in clinical investigations of the physiological actions of plant polyphenols; its potential use in functional nutrition and preventive medicine is also discussed.


Asunto(s)
Enfermedades Cardiovasculares/prevención & control , Flavonoides , Fenoles/uso terapéutico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Agregación Plaquetaria/efectos de los fármacos , Polímeros/uso terapéutico , Vino , Animales , Humanos , Polifenoles
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