Assuntos
Jornalismo Médico , Publicações Periódicas como Assunto/tendências , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Fator de Impacto de Revistas , Jornalismo Médico/história , Jornalismo Médico/normas , Publicações Periódicas como Assunto/históriaRESUMO
The effect of creatine supplementation and sleep deprivation, with intermittent moderate-intensity exercise, on cognitive and psychomotor performance, mood state, effort and salivary concentrations of cortisol and melatonin were examined. Subjects were divided into a creatine supplementation group and a placebo group. They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a day for 7 days immediately prior to the experiment. They undertook tests examining central executive functioning, short-term memory, choice reaction time, balance, mood state and effort at baseline and following 18-, 24- and 36-h sleep deprivation, with moderate intermittent exercise. Saliva samples were taken prior to each set of tests. A group x time analysis of covariance, with baseline performance the covariate, showed that the creatine group performed significantly (p < 0.05) better than the placebo group on the central executive task but only at 36 h. The creatine group demonstrated a significant (p < 0.01) linear improvement in performance of the central executive task throughout the experiment, while the placebo group showed no significant effects. There were no significant differences between the groups for any of the other variables. A significant (p < 0.001) main effect of time was found for the balance test with a linear improvement being registered. Cortisol concentrations on Day 1 were significantly (p < 0.01) higher than on Day 2. Mood significantly (p < 0.001) deteriorated up to 24 h with no change from 24 to 36 h. Effort at baseline was significantly (p < 0.01) lower than in the other conditions. It was concluded that, during sleep deprivation with moderate-intensity exercise, creatine supplementation only affects performance of complex central executive tasks.
Assuntos
Cognição/fisiologia , Creatina/metabolismo , Hidrocortisona/metabolismo , Melatonina/metabolismo , Privação do Sono/metabolismo , Adulto , Afeto/fisiologia , Análise de Variância , Atenção/fisiologia , Creatina/administração & dosagem , Suplementos Nutricionais , Método Duplo-Cego , Exercício Físico/fisiologia , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Resolução de Problemas/fisiologia , Desempenho Psicomotor/fisiologia , Valores de Referência , Saliva/metabolismo , Estatísticas não Paramétricas , Fatores de TempoRESUMO
In 1995 we reported that mean plasma lutein concentrations in salaried men and women from Toulouse in Southern France were double those in subjects recruited from general practitioner lists in Belfast, Northern Ireland. At the time incidence of coronary heart disease (CHD) in Southern France was among the lowest in Europe and was much higher in Northern Ireland. Plasma lutein is a biomarker of vegetable and fruit intake and evidence suggests that high concentrations are generally associated with better cardiometabolic health. At the time we speculated like others that role of the carotenoids may well have been to prevent oxidation of lipid in the lipoproteins and so reduce the uptake of oxidised lipid by macrophages and its deposition within the intimal layers of the major arteries as plaque. It is now widely accepted that CHD is an inflammatory disease and that macrophages within plaque together with tissue damage contribute to this inflammation. Stimulated macrophages release cytokines to activate the immune system both locally and systemically. Precursor complement proteins in the blood are activated to assist immune cells in phagocytosis and cell repair. Individuals with a history of arteriosclerosis display significantly higher concentrations of complement factors C3 and C3a than subjects without such a history. Metabolism of C3 via the alternate complement pathway can give rise to the membrane attack complex (MAC) which creates a hole or pore in pathogens or host cells, killing the cell. Recent studies in patients with early age related macular disease (AMD) who also exhibit similar elevated concentrations of complement proteins in their blood, showed supplementation with lutein progressively decreased the amount of the MAC and other complement factors in the blood. Lutein was used in the supplementation experiments because it is an important constituent of macular pigment. Thus the healthier cardiometabolic features displayed by the people in Toulouse may have been due to the effects of concurrent high concentrations of plasma lutein on the immune system and complement in particular. Other carotenoids may exert similar antioxidant effects but we and others found no differences in antioxidant nutrients between subjects in Toulouse and Belfast or between subjects with asymptomatic markers of atherosclerosis and controls.
Assuntos
Aterosclerose/metabolismo , Doença das Coronárias/metabolismo , Luteína/sangue , Idoso , Antioxidantes/uso terapêutico , Artérias/metabolismo , Biomarcadores/metabolismo , Carotenoides/metabolismo , Complemento C3/metabolismo , Complemento C3a/metabolismo , Proteínas do Sistema Complemento , Dieta , Suplementos Nutricionais , Feminino , França , Frutas , Marcadores Genéticos/genética , Humanos , Inflamação , Lipídeos/química , Lipoproteínas/química , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Irlanda do Norte , Oxigênio/química , Fatores de Risco , Estações do Ano , Verduras , Xantofilas/metabolismoRESUMO
Alzheimer's disease (AD) is a progressive, neurodegenerative disease, characterised by decline of memory, cognitive function and changes in behaviour. Generic markers of lipid peroxidation are increased in AD and reactive oxygen species have been suggested to be involved in the aetiology of cognitive decline. Carotenoids are depleted in AD serum, therefore we have compared serum lipid oxidation between AD and age-matched control subjects before and after carotenoid supplementation. The novel oxidised phospholipid biomarker 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) was analysed using electrospray ionisation tandem mass spectrometry (MS) with multiple reaction monitoring (MRM), 8-isoprostane (IsoP) was measured by ELISA and ferric reducing antioxidant potential (FRAP) was measured by a colorimetric assay. AD patients (n=21) and healthy age-matched control subjects (n=16) were supplemented with either Macushield™ (10mg meso-zeaxanthin, 10mg lutein, 2mg zeaxanthin) or placebo (sunflower oil) for six months. The MRM-MS method determined serum POVPC sensitively (from 10µl serum) and reproducibly (CV=7.9%). At baseline, AD subjects had higher serum POVPC compared to age-matched controls, (p=0.017) and cognitive function was correlated inversely with POVPC (r=-0.37; p=0.04). After six months of carotenoid intervention, serum POVPC was not different in AD patients compared to healthy controls. However, POVPC was significantly higher in control subjects after six months of carotenoid intervention compared to their baseline (p=0.03). Serum IsoP concentration was unrelated to disease or supplementation. Serum FRAP was significantly lower in AD than healthy controls but was unchanged by carotenoid intervention (p=0.003). In conclusion, serum POVPC is higher in AD patients compared to control subjects, is not reduced by carotenoid supplementation and correlates with cognitive function.
Assuntos
Doença de Alzheimer/metabolismo , Transtornos Cognitivos/metabolismo , Suplementos Nutricionais , Éteres Fosfolipídicos/sangue , Fosfolipídeos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/terapia , Antioxidantes/uso terapêutico , Biomarcadores/metabolismo , Carotenoides/química , Carotenoides/uso terapêutico , Transtornos Cognitivos/terapia , Terapia Combinada , Feminino , Humanos , Peroxidação de Lipídeos , Luteína/uso terapêutico , Masculino , Oxirredução , Fosfolipídeos/química , Espécies Reativas de Oxigênio/metabolismo , Zeaxantinas/uso terapêuticoRESUMO
PURPOSE: To compare the impact of sustained supplementation using different macular carotenoid formulations on macular pigment (MP) and visual function in early age-related macular degeneration (AMD). PATIENTS AND METHODS: Sixty-seven subjects with early AMD were randomly assigned to: Group 1 (20 mg per day lutein (L), 0.86 mg per day zeaxanthin (Z); Ultra Lutein), Group 2 (10 mg per day meso-zeaxanthin (MZ), 10 mg per day L, 2 mg per day Z; Macushield; Macuhealth), Group 3 (17 mg per day MZ, 3 mg per day L, 2 mg per day Z). MP was measured using customised heterochromatic flicker photometry and visual function was assessed by measuring contrast sensitivity (CS) and best-corrected visual acuity (BCVA). AMD was graded using the Wisconsin Age-Related Maculopathy Grading System (AREDS 11-step severity scale). RESULTS: At 3 years, a significant increase in MP from baseline was observed in all groups at each eccentricity (P<0.05), except at 1.75° in Group 1 (P=0.160). Between 24 and 36 months, significant increases in MP at each eccentricity were seen in Group 3 (P<0.05 for all), and at 0.50° in Group 2 (P<0.05), whereas no significant increases were seen in Group 1 (P>0.05 for all). At 36 months, compared with baseline, the following significant improvements (P<0.05) in CS were observed: Group 2-1.2, 6, and 9.6 cycles per degree (c.p.d.); Group 1-15.15 c.p.d.; and Group 3-6, 9.6, and 15.15 c.p.d. No significant changes in BCVA, or progression to advanced AMD, were observed. CONCLUSION: In early AMD, MP can be augmented with a variety of supplements, although the inclusion of MZ may confer benefits in terms of panprofile augmentation and in terms of CS enhancement.
Assuntos
Carotenoides/administração & dosagem , Luteína/sangue , Degeneração Macular/tratamento farmacológico , Pigmento Macular/sangue , Zeaxantinas/sangue , Administração Oral , Carotenoides/química , Cromatografia Líquida de Alta Pressão , Sensibilidades de Contraste/efeitos dos fármacos , Sensibilidades de Contraste/fisiologia , Suplementos Nutricionais , Composição de Medicamentos , Humanos , Degeneração Macular/fisiopatologia , Fotometria/métodos , Método Simples-Cego , Acuidade Visual/efeitos dos fármacos , Acuidade Visual/fisiologiaRESUMO
BACKGROUND: Weight reduction is the recommended treatment of obese type 2 diabetes, but the effects of weight reduction on cholesterol metabolism are poorly understood. OBJECTIVE: We investigated glucose, cholesterol, and lipoprotein metabolism at baseline and 2 y after weight reduction in obese patients with type 2 diabetes consuming an isoenergetic diet. DESIGN: Sixteen subjects were randomly chosen to consume a very-low-energy or low-energy diet for 3 mo, after which they consumed a weight-maintenance diet for up to 2 y. Cholesterol absorption and metabolism, LDL and HDL kinetics, and variables of glucose metabolism were studied at baseline and 2 y. RESULTS: Baseline serum sex hormone binding globulin (SHBG) was significantly related to cholesterol absorption efficiency, and serum glucose and insulin concentrations were associated with cholesterol synthesis. After 2 y, body weight was reduced by 6 +/- 1 kg (P < 0.01), body mass index by 6% (P < 0.05), and blood glucose by 14% (P < 0.01); the ratio of serum SHBG to insulin increased by 66% (P < 0.05). Serum and VLDL, LDL, and HDL triacylglycerol were significantly reduced by 13-24%. Despite unchanged serum concentrations of cholesterol, cholesterol absorption efficiency and the ratio of serum plant sterols to cholesterol-indicators of cholesterol absorption-increased by 28% (P < 0.01) and 20-31% (P < 0. 05 for both), respectively; the fractional removal of LDL apolipoprotein B decreased. Fecal excretion of cholesterol as neutral sterols decreased significantly by 11%. Changes in body weight were significantly negatively correlated with changes in ratios of cholesterol to serum plant sterols and cholestanol. CONCLUSIONS: Baseline cholesterol absorption and synthesis were related to respective serum SHBG, glucose, and insulin values. Weight reduction increased cholesterol absorption and improved variables of glucose metabolism. These results suggest that low cholesterol absorption and high synthesis may be part of the insulin resistance syndrome.
Assuntos
Colesterol/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus/dietoterapia , Dieta Redutora , Síndromes de Malabsorção , Obesidade , Glicemia/metabolismo , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Complicações do Diabetes , Diabetes Mellitus/metabolismo , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Insulina/sangue , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Globulina de Ligação a Hormônio Sexual/metabolismoRESUMO
A controlled study was made of the effects of natural orange juice, synthetic orange juice, and placebo in the prevention of the common cold; both natural and synthetic orange juices contained 80 mg of ascorbic acid daily. Three-hundred sixty-two healthy normal young adult volunteers, ages 17 to 25 years, were studied for 72 days with 97% of participants completing the trial. There was a 14 to 21% reduction in total symptoms due to the common cold in the supplemented groups that was statistically significant (P less than 0.05). Ascorbic acid supplementation also increased the number of "episode-free" subjects. However, the clinical usefulness of the results does not support prophylactic ascorbic acid supplements in the well-nourished adult. The results in this study with both natural and synthetic orange juice of physiological content of ascorbic acid, are similar to those obtained using a "megadose" of ascorbic acid.
Assuntos
Ácido Ascórbico/uso terapêutico , Resfriado Comum/prevenção & controle , Flavonoides/uso terapêutico , Adolescente , Adulto , Resfriado Comum/tratamento farmacológico , Feminino , Humanos , Masculino , Fatores Sexuais , Fatores de TempoRESUMO
Red wine polyphenols (RWPPs) were obtained from red wine by absorption and elution from a resin column. Red wine (375 mL/d), white wine (375 mL/d), RWPPs (1 g/d, equivalent to 375 mL red wine/d) in capsules, RWPPs (1 g/d) dissolved in white wine, or a control alcoholic drink (40 g ethanol/d) was given to groups of 6-9 healthy men for 2 wk. Plasma LDL was separated by ultracentrifugation and desalted by dialyzing against a phosphate buffer without EDTA. In the copper-catalyzed peroxidation of LDL (copper-diene assay), the mean lag time increased by 17.8 min after red wine, 14.2 min after RWPP capsules, and 11.7 min after RWPPs in white wine. These groups also showed decreases in thiobarbituric acid-reactive substances, lipid peroxides, and conjugated dienes and increases in plasma and LDL polyphenols. The only change with white wine was an increase in thiobarbituric acid-reactive substances; there were no changes after the control drink. In a second study, RWPPs (1 and 2 g/d) and vitamin E [1000 IU (671 mg)/d] were given for 2 wk. In the copper-diene assay the addition of 10 micromol EDTA/L abolished the increased lag time of 17.7 min seen with 1 g RWPP/d and changed the increased lag time from 13.2 to 4.5 min seen with 2 g RWPP/d. Vitamin E increased lag time by 67.6 min with dialysis without EDTA and by 50.5 min with EDTA. When the column method was used for desalting LDL, all 3 treatments produced an increase in lag time. The failure of some authors to obtain antioxidant effects with the consumption of red wine may be due to the differing techniques.
Assuntos
Antioxidantes/administração & dosagem , Flavonoides , Lipoproteínas LDL/metabolismo , Fenóis/administração & dosagem , Polímeros/administração & dosagem , Vinho , Adulto , Idoso , Doença das Coronárias/prevenção & controle , Ácido Edético/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Polifenóis , Vitamina E/sangueRESUMO
We compared the metabolic effects of 8-wk caloric restrictions with 330 or 780 kcal/d in two groups of eight obese hospitalized subjects; six control subjects were also studied. Loss of weight but not of adipose tissue was significantly greater on the 330-kcal/d diet. It is likely that dehydration rather than protein catabolism was responsible for additional loss of fat-free mass in the 330-kcal/d group because the nitrogen deficit was not excessive. The thermic response to food was blunted only in the 330-kcal/d group whereas resting oxygen uptake decreased by equal amounts in both groups. There was a decrease in 24-h urinary noradrenaline in the 330-kcal/d group but plasma fT4 was sustained when compared with the 780-kcal/d group; fT3 decreased significantly more quickly in the 330-kcal/d group. There was no correlation between plasma hormone levels and changes in oxygen uptake. Hunger scores were greater on the 780-kcal/d diet.
Assuntos
Dieta Redutora , Ingestão de Energia , Obesidade/metabolismo , Adulto , Composição Corporal , Peso Corporal , Catecolaminas/metabolismo , Metabolismo Energético , Feminino , Humanos , Fome , Pessoa de Meia-Idade , Obesidade/dietoterapia , Consumo de Oxigênio , Hormônios Tireóideos/sangueRESUMO
Clofibrate is known to increase cholesterol saturation of bile and the prevalence of gallstones. We studied 10 healthy volunteer subjects to determine the effect of gemfibrozil (a new lipid-lowering agent) on biliary cholesterol saturation and to compare it with that of clofibrate. Biliary cholesterol saturation indices were calculated on fasting duodenal bile samples collected before and after administration of each drug for 4 weeks using a 4-week "washout" period between each preparation. There was a statistically significant rise in the cholesterol saturation index from a control value, taken as the mean of 2 samples, of 1.226 (0.785--1.526), median (range), to 1.547 (0.807--1.781) after clofibrate, P less than 0.05, but the rise to 1.352 (0.840--2.686) after gemfibrozil was not significant. However, direct comparison of the cholesterol saturation indices on clofibrate and gemfibrozil revealed no statistically significant difference. Only prospective clinical trials will establish definitively the risk of cholelithiasis on gemfibrozil but these results suggest that this drug is unlikely to have an advantage over clofibrate in this respect.
Assuntos
Bile/metabolismo , Colesterol/metabolismo , Clofibrato/farmacologia , Hipolipemiantes/farmacologia , Ácidos Pentanoicos/farmacologia , Valeratos/farmacologia , Genfibrozila , Humanos , Lipídeos/sangue , Masculino , Xilenos/farmacologiaRESUMO
A rapid, inexpensive, and quantitative method is described for obtaining the levels of plasma very low, low, and high density lipoproteins using cellulose acetate electrophoresis and lipid assays without prior separation by ultracentrifuge or other techniques. It involves separation of the lipoproteins by cellulose acetate electrophoresis, followed by their identification with the ozone-Schiff reaction. The total lipoprotein concentration is estimated from the total plasma phospholipid, and the percentage of each component obtained by densitometric analysis of the stained electrophoretograms, using reflected light. For samples with a raised level of very low density lipoprotein, plasma triglyceride analysis is also required. The results obtained by the cellulose acetate electrophoresis method are in good agreement with those by the analytical ultracentrifuge and the preparative ultracentrifuge with refractometry. The theoretical assumptions on which the method is based have been shown to be valid.
Assuntos
Eletroforese , Lipoproteínas/sangue , Celulose , Humanos , Métodos , Ozônio , Bases de Schiff , Coloração e Rotulagem , Triglicerídeos/sangue , UltracentrifugaçãoRESUMO
Long-term moderate alcohol use is associated with a better cardiovascular risk profile than total abstinence, although the short-term effect of a bolus of alcohol is unclear. The hypothesis tested in this study was that an acute bolus of alcohol would adversely affect the endothelium and platelets. Blood was taken before and 4 h after the ingestion of red or white wine by nine volunteers per group, and by 11 control water-only drinkers at the same time points. Plasma was obtained and markers of platelet activity (beta-thromboglobulin and soluble P selectin) and endothelial cell function (von Willebrand factor and soluble thrombomodulin) measured by enzyme-linked immunosorbent assay. The only marker to change significantly was beta-thromboglobulin, which increased from a median of 10 ng/ml (interquartile range, 8.5-15) before drinking red wine to 16 ng/ml (interquartile range, 14-20) 4 h later (P = 0.0067). We conclude that an acute bolus of red wine, but not white wine, activates platelets but has no substantial effect on the endothelium.
Assuntos
Endotélio Vascular/efeitos dos fármacos , Etanol/efeitos adversos , Ativação Plaquetária/efeitos dos fármacos , Vinho/efeitos adversos , Adulto , Idoso , Biomarcadores/sangue , Ensaio de Imunoadsorção Enzimática , Etanol/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , beta-Tromboglobulina/análiseRESUMO
To elucidate the relationship between leucocyte copper as a reliable, sensitive index of copper body status and extent of atherosclerosis in patients with Coronary Artery Disease (CAD) the present case-control study was carried out. 80 subjects were studied (23 females and 57 males), aged between 30-70, due to have a angiography. Individual angiograms were scored by combining the individual scores in all the major coronary arteries into one score of a scale 1.00 for patency to 0.00 for severe CAD. Serum and leucocyte copper and zinc were determined by GFAAS. No significant difference between patients with advanced CAD and relatively normal arteries were observed in the lipid profile and levels of plasma copper. Leucocyte copper had a significant link with the severity of atherosclerosis which was independent of sex. There was a linear relationship between the degree of decreasing leucocyte copper concentration and angiogram score. These findings give support to the hypothesis that marginal copper status, assessed by decreased leucocyte copper level, is associated with developing CAD.
Assuntos
Cobre/sangue , Doença da Artéria Coronariana/sangue , Leucócitos/química , Zinco/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Despite the deomnstration of spontaneous atherosclerosis in the wild state, the baboon is not the best species for the production of atherosclerosis experimentally since it develops only a mild hypercholesterolaemia when fed cholesterol. Nevertheless, it is useful for the study of mild lipid deposition in the aorta and the effect of drugs thereon, particularly if protein antigens are also employed in addition. For studies of the hypocholesterolaemic effect of potential therapeutic compounds in man, the baboon fed a high protein commercial diet, with and without cholesterol, is a useful second species to smaller laboratory animals.
Assuntos
Arteriosclerose/metabolismo , Modelos Animais de Doenças , Metabolismo dos Lipídeos , Papio/metabolismo , Farmacologia , Animais , Antígenos/administração & dosagem , Artérias/enzimologia , Artérias/patologia , Colesterol/sangue , Colesterol na Dieta/metabolismo , Dieta Aterogênica , Hipercolesterolemia/etiologia , Fosfatidilcolinas/farmacologia , Coelhos/metabolismoRESUMO
The vitamin and mineral nutritional status of 34 elderly (mean age 77.6 +/- 4.7 years) and 39 younger subjects (mean age 41.7 +/- 7.5 years) from Crevalcore and Montegiorgio (the two rural areas of The Seven Countries Study) was studied. Comparisons have been made between centres, between age groups, and with data obtained from similar surveys performed in 1960 and 1970. Levels of thiamin and riboflavin nutritional status were higher in 1991 than in 1970. Plasma retinol values were above levels of deficiency, but vitamin E and beta-carotene tended to be low. The zinc status of the populations, as assessed by leucocyte zinc concentrations, was generally low. A decline in copper intake during the past ten years may be responsible for the low leucocyte copper concentration which was more apparent in the younger subjects. Serum cholesterol was above, and HDL cholesterol below, the European Atherosclerosis Society recommendations.
Assuntos
Minerais/sangue , Estado Nutricional , Vitaminas/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Carotenoides/sangue , Colesterol/sangue , Cobre/administração & dosagem , Cobre/sangue , Dieta , Humanos , Itália , Leucócitos/química , Masculino , Pessoa de Meia-Idade , Riboflavina/sangue , Tiamina/sangue , Vitamina A/sangue , Vitamina E/sangue , Zinco/sangue , beta CarotenoRESUMO
High intakes of antioxidants in fruit, vegetables and wine are thought to protect against coronary heart disease (CHD). Because people in Toulouse have a much lower incidence of CHD compared with Belfast, the plasma concentrations of antioxidant vitamins and carotenoids in the two populations have been compared. The major difference was in some of the plasma carotenoids. Hydroxy-carotenoids were twice as high in Toulouse in both sexes, notably lutein which occurs principally in dark green vegetables and beta-cryptoxanthin which occurs chiefly in citrus fruits. In addition, alpha-carotene was 50% higher in Toulouse, gamma-tocopherol was 50% higher in Belfast. Other plasma vitamins and carotenoids were not significantly different. If antioxidants play a role in preventing CHD, then the hydroxy-carotenoids are major candidates for further investigation.