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1.
Oecologia ; 202(1): 175-191, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37204497

RESUMO

Phylogenetically closely related plant species often share similar trait states (phylogenetic signal), but local assembly may favor dissimilar relatives and thereby decouple the diversity of a trait from the diversity of phylogenetic lineages. Associated fauna might either benefit from plant trait diversity, because it provides them complementary resources, or suffer from it due to dilution of preferred resources. We hence hypothesize that decoupling of trait and phylogenetic diversity weakens the relationship between the plant-trait diversity and the abundance and diversity of associated fauna. Studying permanent meadows, we tested for combined effects of plant phylogenetic diversity and diversity of two functional traits (specific leaf area, leaf dry matter content) on major groups of soil fauna (earthworms, mites, springtails, nematodes). We found that only in phylogenetically uniform plant communities, was uniformity in the functional traits associated with (i) high abundance in springtails, and (ii) high abundance of the sub-group that feeds more directly on plant material (in springtails and mites) or those that are more prone to disturbance (in nematodes), and (iii) high diversity in all three groups tested (springtails, earthworms, nematodes). Our results suggest that soil fauna profits from the resource concentration in local plant communities that are uniform in both functional traits and phylogenetic lineages. Soil fauna would hence benefit from co-occurrence of closely related plants that have conserved the same trait values, rather than of distantly related plants that have converged in traits. This might result in faster decomposition and a positive feedback between trait conservatism and ecosystem functioning.


Assuntos
Ecossistema , Solo , Filogenia , Plantas , Folhas de Planta
3.
BJOG ; 123(4): 588-97, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26542419

RESUMO

OBJECTIVE: To assess whether antenatal exercise in overweight/obese women would improve maternal and perinatal outcomes. DESIGN: Two-arm parallel randomised controlled trial. SETTING: Home-based intervention in Auckland, New Zealand. POPULATION AND SAMPLE: Pregnant women with body mass index ≥25 kg/m(2) . METHODS: Participants were randomised to a 16-week moderate-intensity stationary cycling programme from 20 weeks of gestation, or to a control group with no exercise intervention. MAIN OUTCOME MEASURES: Primary outcome was offspring birthweight. Perinatal and maternal outcomes were assessed, with the latter including weight gain, aerobic fitness, quality of life, pregnancy outcomes, and postnatal body composition. Exercise compliance was recorded with heart rate monitors. RESULTS: Seventy-five participants were randomised in the study (intervention 38, control 37). Offspring birthweight (adjusted mean difference 104 g; P = 0.35) and perinatal outcomes were similar between groups. Aerobic fitness improved in the intervention group compared with controls (48.0-second improvement in test time to target heart rate; P = 0.019). There was no difference in weight gain, quality of life, pregnancy outcomes or postnatal maternal body composition between groups. However, compliance with exercise protocol was poor, with an average of 33% of exercise sessions completed. Sensitivity analyses showed that greater compliance was associated with improved fitness (increased test time (P = 0.002), greater VO2 peak (P = 0.015), and lower resting heart rate (P = 0.014)), reduced postnatal adiposity (reduced fat mass (P = 0.007) and body mass index (P = 0.035)) and better physical quality of life (P = 0.034). CONCLUSIONS: Maternal non-weight-bearing moderate-intensity exercise in pregnancy improved fitness but did not affect birthweight or clinical outcomes. TWEETABLE ABSTRACT: Moderate-intensity exercise in overweight/obese pregnant women improved fitness but had no clinical effects.


Assuntos
Terapia por Exercício , Obesidade/terapia , Sobrepeso/terapia , Gestantes , Cuidado Pré-Natal , Adulto , Índice de Massa Corporal , Feminino , Humanos , Nova Zelândia/epidemiologia , Obesidade/epidemiologia , Obesidade/prevenção & controle , Sobrepeso/epidemiologia , Sobrepeso/prevenção & controle , Cooperação do Paciente , Gravidez , Resultado da Gravidez , Gestantes/psicologia , Qualidade de Vida , Comportamento de Redução do Risco , Resultado do Tratamento , Aumento de Peso
4.
Curr Microbiol ; 72(2): 133-138, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26507335

RESUMO

The use of sugarcane bagasse hemicellulosic hydrolysates presents an interesting alternative to second generation (2G) ethanol production. Techniques to enhance the fermentation process, e.g., the use of immobilized cells, is one of the key factors for efficient production. Here, the effect of two important parameters (cell concentration in immobilized system and stirring rate) on the 2G ethanol production using the wild Brazilian yeast S. shehatae UFMG-HM 52.2 immobilized in calcium alginate matrix are presented. A 2(2) full factorial design of experiments was carried out to evaluate the effect of cell concentrations in sodium alginate solution for immobilized bead production (3.0, 6.0, and 9.0 g/L) and stirring rate (150, 200, and 250 rpm) for 2G ethanol production. Statistical analysis showed that the use of both variables at low levels enhanced ethanol yield (YP/S). Under these process conditions, YP/S of 0.31 g/g and ethanol productivity (Qp) of 0.12 g/L h were achieved. Results showed the potential of this immobilized yeast in 2G ethanol production from C5 sugars and demonstrate the importance of adequate cell concentration in immobilized systems, a finding that stands to increase bioprocesses yields and productivity.


Assuntos
Reatores Biológicos/microbiologia , Células Imobilizadas/metabolismo , Etanol/metabolismo , Glicosídeo Hidrolases/metabolismo , Saccharomycetales/metabolismo , Biotecnologia/métodos , Brasil
5.
Eur Ann Allergy Clin Immunol ; 44(6): 243-50, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23441442

RESUMO

BACKGROUND: Implication of IgG antibodies to wheat has been alleged in gastrointestinal symptoms. Precise data on the specific IgG levels in healthy subjects are lacking. Our objectives are to compare levels of IgG antibodies to wheat protein fractions in healthy non atopic or atopic subjects, and in healthy professional cyclist subjects, taking into account the quantitative consumption of wheat. METHODS: 24 control subjects and 26 professional cyclist subjects were selected. ELISA was performed to 2 wheat commercial solutions and to 3 wheat protein fractions. RESULTS: No significant difference was observed between non atopic and atopic subjects. For wheat flour extract, physiological norm determined was 3.27 mg/L sIgG concentration +/- 1.25 CI (95% confidence intervals) for the professional cyclists (vs 1.56 mg/L +/- 0.91 CI in control subjects, p-value: 0.040). For gluten solution, physiological norm was 1.42 mg/L +/- 0.60 CI (vs 0.50 +/- 0.24 CI in control subjects, p-value: 0.010). CONCLUSION: Atopic and non atopic healthy adults have a similar level of sIgG to wheat. Increased levels of sIgG are observed correlatively with an excessive consumption, and could contribute to homeostasis of tolerance. Studies searching for a pathogenic role of sIgG in certain pathologies should take into account the quantitative consumption.


Assuntos
Alérgenos/imunologia , Ciclismo , Dieta , Hipersensibilidade Imediata/imunologia , Tolerância Imunológica , Imunoglobulina G/sangue , Triticum/imunologia , Hipersensibilidade a Trigo/imunologia , Adolescente , Adulto , Anticorpos/sangue , Estudos de Casos e Controles , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Homeostase , Humanos , Hipersensibilidade Imediata/diagnóstico , Testes Intradérmicos , Masculino , Pessoa de Meia-Idade , Hipersensibilidade a Trigo/diagnóstico , Adulto Jovem
6.
J Am Nutr Assoc ; 41(3): 325-332, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33734035

RESUMO

OBJECTIVE: This study evaluated whether the consumption of a cereal bar combining different phytoestrogens could contribute to the reduction of climacteric symptoms in women. METHODS: This is a clinical, prospective, randomized, simple-blind trial. Forty-eight women, aged 40-65 years, with climacteric symptoms, from a city in southwestern Paraná, Brazil. Participants were randomly assigned into two groups; Phytoestrogens group (PHY = 24), which received for 90-day period a cereal bar containing 80.73 milligrams of soybean and flaxseed phytoestrogens, and the placebo group (PLA = 24), which consumed rice flakes biscuit. Clinical, sociodemographic and anthropometric data were collected and climacteric symptoms were assessed using the Kupperman Index (KI). RESULTS: Forty-three women were analyzed (PHY = 21 and PLA = 22). There were significant reductions in the overall KI score in both groups at the end of the intervention period (p < 0.05). However, the comparison between the groups using linear regression models presented expressively better symptom improvement in the PHY group -6.43 over time (95% CI: -11.6; -1.26; p < 0.05) KI points, with perimenopausal -15.15 (95% CI: -28.95; -1.35) and postmenopausal women -19.34 (95% CI: -33.68; -4.99) showed considerably greater reductions in symptoms at the end of the intervention period compared to premenopausal women. There was also significant reduction in symptoms of hot flushes, paresthesia, sexual complaints, insomnia and melancholy. CONCLUSION: The consumption of a cereal bar containing phytoestrogens was able to improve the symptoms of climacteric syndrome.


Assuntos
Climatério , Isoflavonas , Grão Comestível , Feminino , Humanos , Isoflavonas/farmacologia , Fitoestrógenos/uso terapêutico , Poliésteres/farmacologia , Estudos Prospectivos
7.
Gait Posture ; 28(1): 164-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18191568

RESUMO

The biomechanical changes in postural control and in motor activities linked to obesity are still not fully understood. The aim of this study was to assess the adaptation in static and dynamic control of equilibrium when the body mass to be stabilized and moved is increased through obesity. Postural stability limits and gait initiation at slow and fast velocities were compared in a case control study that included a group of obese adolescents and a control group of adolescents with normal weight. The consequences of overweight are more clearly evident from the results on dynamic stability of the obese group than those on static equilibrium. Both the lower values of the biomechanical parameters characterizing the progression velocity of gait and the longer duration of the swing phase for the fast velocity condition suggest that obesity acts as a slowing factor. However, the reduction of the postural stability limits of the obese group, their inability to increase the anticipatory phase duration unlike the control group, the increase in the double support phase duration as well as some difficulty in controlling the fall of the centre of gravity suggest that, in these subjects, an adaptive strategy is adopted to preserve equilibrium by limiting progression velocity.


Assuntos
Marcha/fisiologia , Obesidade/fisiopatologia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Adolescente , Fenômenos Biomecânicos , Feminino , Humanos , Masculino
8.
Gait Posture ; 23(2): 149-58, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16399510

RESUMO

There may be concerns about the validity of kinetic models when studying locomotion in obese subjects (OS). The aim of the present study was to improve and validate a relevant representation of obese subject from four kinetic models. Fourteen teenagers with severe primary obesity (BMI = 40 +/- 5.2 kg/m(2)), were studied during jumping. The jumps were filmed by six cameras (synchronized, 50 Hz), associated with a force-plate (1,000 Hz). All the tested models were valid; the linear mechanical analysis of the jumps gave similar results (p > 0.05); but there were significantly different segment inertias when considering the subjects' abdomen (p < 0.01), which was associated with a significantly higher mechanical internal energy expenditure (p < 0.01) than that estimated from Dempster's and Hanavan's model, by about 40 and 30%. The validation of a modelling specifically for obese subjects will enable a better understanding of their locomotion.


Assuntos
Antropometria , Metabolismo Energético/fisiologia , Modelos Biológicos , Movimento/fisiologia , Obesidade/fisiopatologia , Absorciometria de Fóton , Adolescente , Fenômenos Biomecânicos , Humanos
9.
Cancer Res ; 46(11): 5903-12, 1986 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2428487

RESUMO

The process of chemical hepatocarcinogenesis is characterized by the appearance of preneoplastic lesions showing changes in the expression of various marker enzymes. We have analyzed the phenotype of small preneoplastic foci and expansively growing nodules in liver sections obtained from rats treated with various carcinogens. Changes within the lesions in canalicular adenosine triphosphatase, gamma-glutamyl transpeptidase, NADPH-(cytochrome P-450) reductase, cytochrome P-450 PB2, epoxide hydrolase, and glycogen content were detected by means of enzyme histochemical and immunohistochemical staining procedures. In parallel sections the expression of albumin messenger RNA was investigated by in situ hybridization using a 35S-labeled albumin specific complementary DNA probe. In general, small preneoplastic lesions showed unchanged levels of albumin messenger RNA. In contrast, the expression of albumin messenger RNA was found to be reduced to varying degrees in large hepatic nodules. An expression of alpha-fetoprotein messenger RNA could not be detected in any of the nodules. No direct correlation between the enzyme phenotype of the lesions and the degree in reduction of albumin messenger RNA could be established except that the reduction was most pronounced in nodules which had lost their ability to store glycogen. Since the synthesis and excretion of albumin is a typical function of the differentiated hepatocyte in the adult animal, the observed decrease in albumin messenger RNA expression in large hepatic nodules is in accordance with the hypothesis of a gradual dedifferentiation or retrodifferentiation of the cell population during carcinogenesis. Hyperplastic nodules produced by continuous treatment of rats with 4-dimethylaminoazobenzene showed increased rather than decreased albumin levels. The analysis of albumin messenger RNA expression might therefore be used as a tool to discriminate between nodules of differing biological nature and fate.


Assuntos
Albuminas/genética , Neoplasias Hepáticas/genética , Lesões Pré-Cancerosas/genética , RNA Mensageiro/genética , Adenosina Trifosfatases/metabolismo , Animais , Feminino , Regulação da Expressão Gênica , Glicogênio Hepático/metabolismo , Neoplasias Hepáticas/patologia , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Hibridização de Ácido Nucleico , Lesões Pré-Cancerosas/patologia , Ratos , alfa-Fetoproteínas/genética , gama-Glutamiltransferase/metabolismo
10.
Biochim Biophys Acta ; 729(2): 209-18, 1983 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-6830788

RESUMO

Intestinal brush border vesicles of a Mediterranean sea fish (Dicentrarchus labrax) were prepared using the Ca2+-sedimentation method. The transport of glucose, glycine and 2-aminoisobutyric acid is energized by an Na+ gradient (out greater than in). In addition, amino acid uptake requires Cl- in the extravesicular medium (2-aminoisobutyric acid more than glycine). This Na+- and Cl--dependent uptake is electrogenic, since it can be stimulated by negative charges inside the vesicles. The specific Cl- requirement of glycine and 2-aminoisobutyric acid transport is markedly influenced by pH, a change from 6.5 to 8.4 reducing the role played by Cl-. In the presence of Cl-, the Km of 2-aminoisobutyric acid uptake is reduced and its Vmax is enhanced. Cl- affects also a non-saturable Na+-dependent component of this amino acid uptake. Amino acid transport is also increased by intravesicular Cl- (2-aminoisobutyric acid less than glycine). This effect is more concerned with glucose uptake, which can be then multiplied by 2.3. A concentration gradient (in greater than out) as well as the presence of Na+ in the incubation medium seems to enter into this requirement. This intravesicular Cl- effect is not influenced by pH between 6.5 and 8.4.


Assuntos
Aminoácidos/metabolismo , Cloretos/metabolismo , Glucose/metabolismo , Intestinos/ultraestrutura , Sódio/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Peixes , Concentração de Íons de Hidrogênio , Potenciais da Membrana , Microvilosidades/metabolismo , Valinomicina/farmacologia
11.
Bone ; 17(6): 513-6, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8835303

RESUMO

Twenty-eight young male adolescents (age from 13 years 6 months to 15 years 9 months) from a horseback-riding school were studied. They were studied at the end of summer (September of 1993) and, six months later, at the end of winter (March of 1994). At each timepoint their height and weight were measured and their pubertal status determined. Blood was collected and 25-hydroxyvitamin D [25(OH)D], intact parathyroid hormone (PTH1-84), and 1,25-dihydroxy-vitamin D [1,25(OH)2D] were measured. After winter, weight and height had increased by a mean of 2.9 +/- 1.3 kg and of 3.3 +/- 1.2 cm, respectively. 25(OH)D concentrations which were 29.96 +/- 7.46 micrograms/L in September had significantly (p = 0.0001) fallen by a mean of 23.31 +/- 6.6 micrograms/L in March (6.61 +/- 2.04 micrograms/L). March and September concentrations of 25(OH)D were significantly correlated (r = 0.536, p = 0.0039). March values were negatively correlated with the pubertal status (r = 0.41; p = 0.03). In the meantime, PTH had significantly (p = 0.0001) increased by a mean of 8.59 +/- 8.53 ng/L (22.8 +/- 7.44 ng/L in September vs. 30.33 +/- 8.05 ng/L in March). A statistically significant correlation between PTH and 25(OH)D concentrations (r = 0.493; p = 0.0001) was obtained. Serum 1,25(OH)2D concentrations measured in September (37.7 +/- 12.94 ng/L) and in March (38.2 +/- 7.8 ng/L) were not different. March values were positively correlated with pubertal status (r = 0.49; p = 0.008). Modulation of PTH secretion by vitamin D appears to be a physiological mechanism occurring during adolescence. In spite of a marked depletion of vitamin D stores after winter, PTH values remained within normal range. Nevertheless, we cannot exclude that a more prolonged vitamin D deficiency could adversely affect bone metabolism during this critical period of life characterized by an increased need of vitamin D.


Assuntos
25-Hidroxivitamina D 2/sangue , Hormônio Paratireóideo/sangue , Vitamina D/sangue , Adolescente , Adulto , Cálcio da Dieta , Proteínas Alimentares , Humanos , Masculino , Valores de Referência , Estações do Ano , Luz Solar , População Branca
12.
Eur J Endocrinol ; 130(1): 53-9, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8124479

RESUMO

In this cross-sectional study on 140 subjects, several testosterone and epitestosterone metabolites have been analyzed by gas chromatography-mass spectrometry associated with stable isotope dilution, a technique requested for doping analysis in general, and detection of exogenous testosterone supply in particular. Urinary excretions of luteinizing hormone, testosterone and epitestosterone glucuronides and sulfates, as well as glucuronides of 5-androstene-3 beta, 17 alpha-diol, 5 alpha- and 5 beta-androstane-3 alpha, 17 alpha-diol and the corresponding 17 beta-isomers, present similar patterns of increase throughout pubertal development, from stage 1 up to stage 5. Excretion levels are significantly different in general between stages 1, 2, 3 and 4, the highest percentage increase being observed between stages 3 and 4. None of the ratios of testosterone to epitestosterone glucuronides are beyond the threshold value of 6, where testosterone abuse by athletes is suspected. No particular pubertal stage exceeded this critical value with a probability higher than p = 0.006, a value that was determined on the whole population. This is consistent with the non-significant differences between correlation slopes of regression curves, relating either testosterone or epitestosterone glucuronide to chronological age. The ratio of testosterone glucuronide to luteinizing hormone increases significantly throughout puberty and this might be a limitation to the widespread use of this ratio for the detection of testosterone misuse.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Epitestosterona/metabolismo , Exercício Físico/fisiologia , Puberdade/metabolismo , Esportes , Testosterona/metabolismo , Adolescente , Adulto , Androstano-3,17-diol/urina , Androstenodiol/urina , Estudos Transversais , Dopagem Esportivo , Epitestosterona/urina , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Hormônio Luteinizante/urina , Masculino , Valores de Referência , Análise de Regressão , Testosterona/análogos & derivados , Testosterona/urina
13.
Sports Med ; 4(4): 268-89, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3306867

RESUMO

Anaerobic tests are divided into tests measuring anaerobic power and anaerobic capacity. Anaerobic power tests include force-velocity tests, vertical jump tests, staircase tests, and cycle ergometer tests. The values of maximal anaerobic power obtained with these different protocols are different but generally well correlated. Differences between tests include factors such as whether average power or instantaneous power is measured, active muscle mass is the same in all the protocols, the legs act simultaneously or successively, maximal power is measured at the very beginning of exercise or after several seconds, inertia of the devices and body segments are taken into account. Force-velocity tests have the advantage of enabling the estimation of the force and velocity components of power, which is not possible with tests such as a staircase test, a vertical jump, the Wingate test and other long-duration cycle ergometer protocols. Maximal anaerobic capacity tests are subdivided into maximal oxygen debt test, ergometric tests (all-out tests and constant load tests), measurement of oxygen deficit during a constant load test and measurement of peak blood lactate. The measurement of the maximal oxygen debt is not valid and reliable enough to be used as an anaerobic capacity test. The aerobic metabolism involvement during anaerobic capacity tests, and the ignorance of the mechanical efficiency, limit the validity of the ergometric tests which are only based on the measurement of work. The amount of work performed during the Wingate test depends probably on glycolytic and aerobic power as well as anaerobic capacity. The fatigue index (power decrease) of the all-out tests is not reliable and depends probably on aerobic power as well as the fast-twich fibre percentage. Reliability of the constant load tests has seldom been studied and has been found to be rather low. In theory, the measure of the oxygen deficit during a constant load test is more valid than the other tests but its reliability is unknown. The validity and reliability of postexercise blood lactate as a test of maximal anaerobic capacity are probably not better than that of the current erogmetric tests. The choice of an anaerobic test depends on the aims and subjects of a study and its practicability within a testing session.


Assuntos
Teste de Esforço/métodos , Anaerobiose , Teste de Esforço/normas , Humanos , Lactatos/sangue , Contração Muscular
14.
Steroids ; 63(2): 80-7, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9516717

RESUMO

Dehydroepiandrosterone (DHEA) replacement therapy as compensation for high age-related decline of DHEA and DHEA sulfate production is a matter of intense investigation, since many beneficial effects have been proven, or are suggested and expected. Therefore, DHEA abuse by athletes has been considered by the International Olympic Committee, which banned the substance recently. As DHEA for oral supplementation is easily available, we decided to investigate the effect on the urinary androgen profile of administration along this route of a single substitution dose of 50 mg. Quantitative analysis by gas chromatography-mass spectrometry with selected ion monitoring demonstrated that the drug was readily absorbed with 50 to 75% recovery of dosing after 24 h, and with glucuro- and sulfoconjugates of DHEA, androsterone, and etiocholanolone as the most abundant metabolites. In agreement with reported data found in blood, conversion of exogenous DHEA to the principal biologically active androgen, testosterone, was low but proven to be real by the administration of deuterium-labeled DHEA and the subsequent identification and quantification of deuterium-labeled testosterone. A concentration threshold of 300 micrograms/L of DHEA glucuronide is proposed for the screening of DHEA abuse in sport, but a single replacement dose can only be detected during 8 h. Such a short detection period is the consequence of considerable first-pass hepatic metabolism and also of the high interindividual variability of circulating and urinary DHEA and DHEA sulfate concentrations.


Assuntos
Androgênios/urina , Desidroepiandrosterona/administração & dosagem , Dopagem Esportivo , Cromatografia Gasosa-Espectrometria de Massas , Adulto , Androsterona/urina , Ritmo Circadiano , Desidroepiandrosterona/farmacocinética , Sulfato de Desidroepiandrosterona/urina , Deutério , Etiocolanolona/urina , Glucuronatos/urina , Humanos , Cinética , Masculino , Testosterona/urina
15.
Eur J Clin Nutr ; 47(6): 445-53, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8365386

RESUMO

Reported dietary intake records of 30 subjects (26 men and 4 women) were analysed by three different centres using their own computerized nutrient database systems. The agreement between systems was evaluated by different statistical criteria (the correlation coefficient, the mean difference and the proportion of individuals placed in the same thirds of distribution). Significant differences between the three systems were found in the calculation of alcohol, polyunsaturated fatty acids, saturated fatty acids, linoleic acid, linolenic acid, cholesterol, magnesium, sodium and water. To ascertain the extent of mean differences that could be attributed to the coding process or to the database used, coding forms of each centre were forwarded to the other two centres. Analysis of variance showed that differences in the data obtained by the three systems were mainly due to the food composition database used.


Assuntos
Registros de Dieta , Dieta , Processamento Eletrônico de Dados , Análise de Variância , Redes de Comunicação de Computadores , Bases de Dados Factuais , Feminino , Análise de Alimentos , Humanos , Masculino
16.
J Biomech ; 21(7): 577-84, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3410860

RESUMO

An experimental method has been developed to analyse muscular forces and torques in vivo during isometric flexion of the elbow in small monkeys (Macaca fascicularis). A mini-transducer was built with a view to measure forces in situ, without cutting tendons. The positions of tendon insertions were measured on anatomical parts, then integrated in a series of calculations aiming of deducing the lever arms of forces to be included in a torque equilibrium relationship. Muscle activity of the three main flexors was measured for five angles of isometric flexion between 70 degrees and 110 degrees, 0 degrees corresponding to the full extended forearm. The analysed signals were selected using physiological and biomechanical criteria. Then, results corresponding to force participation, and torque participations, were worked out; they are presented and discussed in the present paper.


Assuntos
Articulação do Cotovelo/fisiologia , Contração Isométrica , Contração Muscular , Músculos/fisiologia , Animais , Fenômenos Biomecânicos , Eletromiografia , Macaca fascicularis , Próteses e Implantes , Transdutores
17.
Arch Physiol Biochem ; 103(2): 160-4, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-9338087

RESUMO

Hormonal changes during exercise is of growing interest because of their role in adaptation, and performance. The production of amino acids (AA) due to the degradation of muscle protein increases during exercise and some AA may be utilized for energy expenditure or as hormonal secretagogues. Thus, one can propose a strategy to reduce muscle protein breakdown and regulate hormones involved in energy metabolism by dietary AA supplementation. We assessed the effects of glutamate-arginine salt (AGs) ingestion on exercise-induced hormonal alterations in highly trained cyclists (age 18-22 yrs). Using an indwelling catheter, we collected multiple blood samples at rest, during warm up, during and after an intense exercise session. Plasma growth hormone (hGH), insulin and cortisol were measured by radioimmunoassay. As reported in previous studies, we observed a marked increase in plasma hGH and cortisol levels during and after exercise in the placebo (Pl) condition as well as a slight decrease in insulin concentration. In addition, we found that the ingestion of AGs had significant effects on some dynamic hormonal changes. AGs had no effect on resting plasma levels of hGH, insulin or cortisol. However, the marked elevation in cortisol and hGH during and after exercise in the placebo condition, was greatly diminished when subjects ingested AGs. Our results show that AGs can modify exercise-induced hormonal changes and raise the possibility that it may be used to alter energy metabolism during endurance exercise.


Assuntos
Arginina/farmacologia , Exercício Físico/fisiologia , Ácido Glutâmico/farmacologia , Hormônio do Crescimento Humano/sangue , Hidrocortisona/sangue , Insulina/sangue , Adolescente , Adulto , Ciclismo , Metabolismo Energético , Humanos , Cinética , Proteínas Musculares/metabolismo
18.
Arch Mal Coeur Vaiss ; 83(2): 229-34, 1990 Feb.
Artigo em Francês | MEDLINE | ID: mdl-2106859

RESUMO

The use of an original ultrasonic transducer holder has made possible the recording of M mode and 2D echocardiography during exercise. Left ventricular function was studied during upright bicycle exercise in two groups: 10 trained athletes (Group A) and 10 normal subjects (Group B). All were 20 years of age. Satisfactory echocardiograms were obtained up to a mean heart rate of 180/mn which corresponded to an average work load of 180 W in Group B and 300 W in Group A. The cardiac output was comparable in the two groups up to a 180 W load, but in Group A a lower HR was compensated by a larger stroke volume (SV). The increase in SV in Group A was related to a greater LV end-diastolic dimension (LVEDD) during exercise, whereas the ejection fraction increased less than in the control group. During very strenuous exercise (Group A only) further increases in cardiac output were related mainly to an increased heart rate and to a lesser degree to increased LVEDD and ejection fraction.


Assuntos
Ecocardiografia , Esportes , Função Ventricular , Adulto , Teste de Esforço , Hemodinâmica , Humanos , Masculino , Esforço Físico/fisiologia
19.
Arch Pediatr ; 5(11): 1211-5, 1998 Nov.
Artigo em Francês | MEDLINE | ID: mdl-9853057

RESUMO

BACKGROUND: Recently, 25 hydroxyvitamin D (25 OHD) blood concentrations measured in adolescents during or at the end of winter were found very low. A concomitant stimulation of parathyroid function was observed. The aim of the present study was to test the biological effects of a treatment with vitamin D3 during winter. POPULATIONS AND METHODS: The effects of vitamin D3 supplementation (100,000 IU, twice, at the end of November and of January) were assessed in 24 male Caucasian adolescents (mean age +/- SD: 14 y 6 m +/- 9 m). They were pupils in a lad-jockeys training center located in the countryside near Chantilly (49 degrees northern latitude). Blood concentrations of 25 OHD, calcium and intact parathormone (PTH) were measured three times: before each oral intake of vitamin D3 and 2 months after the last intake (March). A group of 32 male adolescents (mean age +/- SD: 14 y 9 m +/- 6 m), pupils in the same center, receiving no vitamin D and sampled in November and in March, served as controls. RESULTS: In March, mean concentrations of 25 OHD (8.36 +/- 2.73 micrograms/L) were very low in vitamin D-not supplemented adolescents since 34% had levels less than 6 micrograms/L. In March, PTH concentrations (40.5 +/- 12.2 ng/L) were significantly (P = 0.0001) higher than in November (28.8 +/- 9.9 ng/L). In boys receiving vitamin D3 25 OHD serum concentrations measured in January (17.5 +/- 3.2 micrograms/L) and in March (18.7 +/- 4.0 micrograms/L) remained at a level not very different from that measured in November (16.6 +/- 3.8 micrograms/L). During the same period, calcium and PTH concentrations (32.2 +/- 11.7 ng/L in November; 32.4 +/- 14.3 in January and 32.9 +/- 13.5 ng/L in March) remained at their basal level as well. CONCLUSIONS: The observation that, after winter, a relatively large number of adolescents presented low concentrations of 25 OHD suggests that, during winter, usual dietary intakes and/or vitamin D stores are not sufficient to provide for their needs. Administration of two oral doses of 100,000 IU of vitamin D3 could maintain the vitamin D status at its initial level. The efficiency of such a prophylactic treatment is also assessed by its effect on parathyroid function.


Assuntos
Colecalciferol/administração & dosagem , Estações do Ano , Deficiência de Vitamina D/prevenção & controle , Adolescente , Estudos Transversais , França/epidemiologia , Humanos , Incidência , Masculino , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/epidemiologia
20.
Artigo em Francês | MEDLINE | ID: mdl-3734341

RESUMO

The cycle ergometer (an exercise cycle) Monark was used to study the repercussions on the fetus of physical exercises carried out by the mother at the end of pregnancy (after 37-39 weeks of amenorrhoea). The maternal and fetal heart rates were measured at the same time while the mother was pedalling against increasing resistance. This was a form of sub-maximal aerobics. Fourteen women took part in the study but only six traces could be analysed. The mean duration of the exercises was 15 (+/- 2.5) minutes. The mothers' heart rate rose from 84 (+/- 7) beats a minute (bpm) before exercise to 153 (+/- 14) bpm at the last level reached. It took 15.6 (+/- 4) minutes for the maternal heart rate to return to what it was before exercise. The basal fetal heart rate was around 144 (+/- 5) bpm before exercise and rose to 170 (+/- 12) during exercise with no change in the oscillations in the fetal heart rate. After exercise the fetal rate slowed down very slowly and there was a marked diminution in the amplitude of the oscillations (Hammacher's Type 1). They never disappeared. Those few women who were in "false labour" during the test went out of false labour. We have hypothesised that the fetal heart rate rises significantly during the mother's exercise and this action is a mechanical one rather than a humoral or hormonal one. When exercise stops the diminution in oscillations, which is rapid, could be a sign of the fetus becoming drowsy, or it could be due to the intervention of maternal factors.


Assuntos
Coração Fetal/fisiologia , Frequência Cardíaca , Esforço Físico , Adulto , Teste de Esforço , Feminino , Humanos , Gravidez , Terceiro Trimestre da Gravidez , Fatores de Tempo
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