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1.
Eur J Appl Physiol ; 121(1): 297-306, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33057877

RESUMO

PURPOSE: High altitude results in lower barometric pressure and hence partial pressure of O2 decrease can lead to several molecular and cellular changes, such as generation of reactive oxygen species (ROS). Electron Paramagnetic Resonance technique was adopted in the field, to evaluate the effects of acute and sub-acute hypobaric hypoxia (HH) on ROS production by micro-invasive method. Biological biomarkers, indicators of oxidative stress, renal function and inflammation were investigated too. METHODS: Fourteen lowlander subjects (mean age 27.3 ± 5.9 years) were exposed to HH at 3269 m s.l. ROS production, related oxidative damage to cellular components, systemic inflammatory response and renal function were determined through blood and urine profile performed at 1st, 2nd, 4th, 7th, and 14th days during sojourn. RESULTS: Kinetics of changes during HH exposition showed out significant (range p < 0.05-0.0001) increases that at max corresponds to 38% for ROS production rate, 140% for protein carbonyl, 44% for lipid peroxidation, 42% for DNA damage, 200% for inflammatory cytokines and modifications in renal function (assessed by neopterin concentration: 48%). Conversely, antioxidant capacity significantly (p < 0.0001) decreased - 17% at max. CONCLUSION: This 14 days in-field study describes changes of oxidative-stress biomarkers during HH exposure in lowlanders. The results show an overproduction of ROS and consequent oxidative damage to protein, lipids and DNA with a decrease in antioxidant capacity and the involvement of inflammatory status and a transient renal dysfunction. Exposure at high altitude induces a hypoxic condition during acute and sub-acute phases accompanied by molecular adaptation mechanism indicating acclimatization.


Assuntos
Doença da Altitude/metabolismo , Estresse Oxidativo , Adulto , Doença da Altitude/sangue , Doença da Altitude/urina , Citocinas/sangue , Dano ao DNA , Feminino , Hemoglobinas/metabolismo , Humanos , Masculino , Neopterina/urina , Carbonilação Proteica
2.
Rev. bras. plantas med ; 15(2): 273-279, 2013. tab
Artigo em Português | LILACS | ID: lil-677037

RESUMO

Os objetivos deste trabalho foram: identificar as espécies vegetais utilizadas com fins medicinais pela comunidade de Ipameri (Estado de Goiás); investigar as preferências com relação à produção e comercialização dessas plantas; e diagnosticar o perfil de gênero e as faixas etárias e salariais de seus usuários. Para isso, foram realizadas entrevistas estruturadas com 200 famílias da cidade e coletadas as plantas visando-se a sua correta identificação. O material foi herborizado, identificado e depositado no Herbário da Universidade Estadual de Goiás (HUEG). Das 200 famílias entrevistadas, 75 disseram não fazer uso de plantas com fins medicinais (37,5%), enquanto 125 afirmaram fazê-lo (62,5%). O grupo que utiliza relacionou 35 espécies mais empregadas: hortelã-rasteira (Mentha x villosa L.), boldo-sete-dores (Plectranthus barbatus Andrews.), capim-cidreira (Cymbopogon citratus (DC.) Stapf.), quebra-pedra (Phyllanthus niruri L.), camomila (Chamomilla recutita (L.) Rauschert.), poejo (Mentha pulegium L.), guaco (Mikania glomerata Spreng.), mentrasto (Ageratum conyzoides L.), alfavacão (Ocimum gratissimum L.), losna (Artemisia canphorata Vill.), bálsamo (Eysenhardtia platycarpa Mich.), carqueja (Baccharis trimera (Less.) DC.), funcho (Foeniculum vulgare Mill.), babosa (Aloe vera L.) e malva (Althaea officinalis L.). Todas as famílias consumidoras (100%) afirmaram preferir as plantas cultivadas de forma orgânica, selecionando-as através da boa aparência (68% das famílias) e consumindo-as in natura (sem beneficiamento, 100%). A utilização de plantas medicinais em Ipameri é independente do sexo (54%, mulheres e 46%, homens) e se estende às várias faixas etárias e também sócio-econômicas, configurando-se assim, um bom mercado consumidor.


The aims of this study were: to identify the plant species used for medicinal purposes by the community at Ipameri (Goiás State); to investigate the preferences with respect to the production and marketing of these plants; and to diagnose the gender profile and the age and wage ranges of users. Thus, structured interviews were conducted with 200 families in the city and plants were collected for their correct identification. The material was herborized, identified and deposited in the Herbarium of "Universidade Estadual de Goiás" (HUEG). Of the 200 families interviewed, 75 said they did not make use of plants for medicinal purposes (37.5%), while 125 said they do use them (62.5%). The latter group reported the 35 most used species: "hortelã-rasteira" (Mentha x villosa L.), "boldo-sete-dores" (Plectranthus barbatus Andrews.), lemon grass (Cymbopogon citratus (DC.) Stapf.), "quebra-pedra" (Phyllanthus niruri L.), chamomile (Chamomilla recutita (L.) Rauschert.), pennyroyal (Mentha pulegium L.), guaco (Mikania glomerata Spreng.), mentrasto (Ageratum conyzoides L.), clove basil (Ocimum gratissimum L.), wormwood (Artemisia canphorata Vill.), balm (Eysenhardtia platycarpa Mich.), broom (Baccharis trimera (Less.) DC.), fennel (Foeniculum vulgare Mill.), aloe (Aloe vera L.) and mallow (Althaea officinalis L.). All consumer families (100%) stated to prefer plants grown organically, to select the plants based on their good appearance (68% families) and to eat them in natura (unprocessed, 100%). The use of medicinal plants in Ipameri is independent of gender (54% womem and 46% men) and extends to several age and socioeconomic ranges, configuring thus a good consumer market.


Assuntos
Humanos , Masculino , Feminino , Coleta de Dados/métodos , Etnobotânica/instrumentação , Plantas Medicinais/classificação , Pesquisa Participativa Baseada na Comunidade
3.
Magn Reson Imaging ; 22(6): 877-89, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15234458

RESUMO

Proton nuclear magnetic resonance (NMR) spin-spin relaxation and imaging have been applied to investigate white Portland cement pastes during hydration in the absence and in the presence of organic solvents. The main organic solvent investigated was methanol, alone or together with the organic waste 2-chloroaniline (2-CA), an aromatic amine representative of an important class of highly toxic compounds. For all the analysed samples, prepared with a solvent-to-cement ratio of 0.4, the decay of the echo magnetization has been fitted by adopting a model that combines an exponential component with a gaussian one. The calculated independent relaxation parameters have been discussed in terms of morphological and dynamical changes that occur during the cement hardening process and pore formation. Three kinds of water molecules: "solid-like" (chemically and physically bound), "liquid-like" (porous trapped) and "free" water, endowed with anisotropic, near isotropic and isotropic motion, respectively, were identified. Spin-echo images collected on the same samples during the hydration kinetics, allowed the changes of water and solvents spatial distribution in the porous network to be monitored, showing percolation phenomena and confirming the multimodal open channels structure of the hardened cement system. Both T(2) relaxation and imaging data indicated that a pronounced delay occurs in the cement hardening when organics are present.


Assuntos
Materiais de Construção/análise , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Metanol/análise , Porosidade , Prótons , Solventes/análise
4.
Rev Esp Cardiol ; 55(10): 1057-62, 2002 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-12383391

RESUMO

INTRODUCTION AND OBJECTIVES: Transcatheter closure of patent ductus arteriosus is a well-established procedure. The aim of this study was to assess the initial and mid-term results of the treatment of PDA with the Amplatzer duct occluder. PATIENTS AND METHODS: From October 1999 to December 2001, 30 children underwent transcatheter closure of persistent ductus arteriosus at a mean SD age of 5 4.02 years (range: 3 months to 14 years) and weight of 20.3 10.3 kg (range: 4.5-45 kg). Infants under 10 kg weight made up 46% of total patients. A lateral view aortogram was made to determine the morphology of the ductus and select the size of the device. Occlusion was achieved using the anterograde venous approach. Follow-up evaluations were made with chest X-ray and echocardiogram at 24 hours and 1, 4 and 12 months after implantation. RESULTS: Twenty-eight patients (93.3%) immediately achieved complete occlusion, and on color Doppler examination the closure rate was 100% within 24 hours of implantation. There was no device embolization. In the follow-up, a 19-month-old patient developed a 20 mmHg gradient across the aortic arch. CONCLUSIONS: Patent ductus arteriosus can be easily occluded with the Amplatz Duct Occluder, which is effective and particularly useful in infants and children with relatively large PDA. Further experience and long-term follow-up are still needed to assess the safety of this device in smaller children.


Assuntos
Permeabilidade do Canal Arterial/terapia , Próteses e Implantes , Adolescente , Fatores Etários , Aortografia , Criança , Pré-Escolar , Permeabilidade do Canal Arterial/diagnóstico por imagem , Seguimentos , Humanos , Lactente , Desenho de Prótese , Radiografia Torácica , Fatores de Tempo , Ultrassonografia Doppler
5.
Rev. esp. cardiol. (Ed. impr.) ; 55(10): 1057-1062, oct. 2002.
Artigo em Es | IBECS | ID: ibc-15128

RESUMO

Introducción y objetivos. El cierre percutáneo del ductus arterioso es una técnica establecida. Nuestro objetivo fue evaluar los resultados obtenidos a corto y medio plazo en el tratamiento del ductus con el dispositivo oclusor de Amplatz. Pacientes y métodos. Desde octubre de 1999 a diciembre de 2001, 30 niños con edad media de 5 ñ 4,02 años (rango: 3 meses-14 años) y peso medio de 20,3 ñ 10,3 kg (rango: 4,5-45 kg) fueron sometidos al cierre percutáneo del ductus. El 46 por ciento eran lactantes de peso < 10 kg. Mediante aortografía en proyección lateral se determinó la morfología del ductus, y se seleccionó el tamaño del dispositivo, que se implantó por vía venosa anterógrada. Se realizaron controles radiológios y ecocardiográficos a las 24 h, y a los meses 1,4 y 12 postimplante. Resultados. Se consiguió la oclusión de forma inmediata en 28 de los 30 pacientes (93,3 por ciento), y en la ecografía realizada a las 24 h la tasa de oclusión completa fue del 100 por ciento. No hubo ningún caso de migración del dispositivo.Un paciente de 19 meses desarrolló en el seguimiento un gradiente de 20 mmHg en el istmo aórtico. Conclusiones. El cierre percutáneo del ductus con el dispostivo oclusor de Amplatz es un método seguro y efectivo, especialmente útil en el tratamiento de ductus moderados o grandes. Estudios más amplios y a más largo plazo son necesarios para determinar su seguridad en los pacientes pediátricos de menor peso (AU)


Assuntos
Criança , Pré-Escolar , Adolescente , Lactente , Humanos , Próteses e Implantes , Fatores de Tempo , Radiografia Torácica , Ultrassonografia Doppler , Desenho de Prótese , Aortografia , Permeabilidade do Canal Arterial , Fatores Etários , Seguimentos
6.
Rev Esp Cardiol ; 54(10): 1190-6, 2001 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-11591300

RESUMO

OBJECTIVES: Percutaneous device occlusion of atrial septal defects (ASD) is, although with some limitations, an alternative to surgical closure. The aim of this study was to evaluate the efficacy and safety of percutaneous ASD closure using the Amplatz device. PATIENTS AND METHODS: From October 1999 to March 2000, 25 children underwent transcatheter closure of ASD at a mean +/- SD age of 8.7 +/- 3.1 years (range 3-15 years) and a mean weight of 31.8 +/- 16.7 kg (range 11-84 kg). Device selection was based on the stretched diameter of the ASD using the PTA OS balloon. The device was implanted under ultrasonographic and radiological guidance. All patients showed signs of volume-overload of the right ventricle. The ASD was single (n = 21), with two separate holes (n = 2), or cribiform (n = 2). RESULTS: The median +/- SD size of the device used was 21.7 +/- 5.4 mm (range 15-36 mm). In twenty-two patients (88%) the device was successfully implanted. A repeat echocardiogram was performed the next day before discharge. Two patients underwent surgery after deployment of the device due to mitral valve dysfunction (n = 1) or residual leak (n = 1). In a patient with a two-hole ASD, another device was percutaneously withdrawn, while still attached to the delivery cable due to incomplete occlusion. CONCLUSION: a) Transcatheter occlusion with the Amplatzer device is an effective treatment for ostium secundum atrial septal defects; b) the low complication rate and the short hospitalization period makes this procedure the treatment of choice in these patients, and c) ASD which are too large, cribiform or with deficient rims may require a different approach.


Assuntos
Comunicação Interatrial/cirurgia , Próteses e Implantes , Adolescente , Criança , Pré-Escolar , Ecocardiografia , Seguimentos , Comunicação Interatrial/diagnóstico por imagem , Humanos
7.
Magn Reson Imaging ; 19(10): 1311-22, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11804759

RESUMO

MRI was applied to investigate the transport pathways in Morning Glory plant stems. The study was carried out on living plants without affecting their integrity. The architecture of a dicotyledonous plant was deeply characterized: the root system structure and the vascular bundle location were identified, the presence of central voids caused by cell maturation and loss were observed in the stem. Molecular transport components were recognized, by observing the concentration profile of a tracer, which changed with time after its absorption by the plant roots. MRI analysis revealed the presence of an axial transport as the progress of the tracer front through the vascular bundles and a radial molecular transport from the vascular bundles toward the surface of the stem. As a result, the tracer molecular transport formed the parabolic tracer front (PTF). A model was built up through the analysis of the PTF that consisted of an axial front at the peak position and a radial front at the width of the parabolic tail. PTF analysis revealed differences between the tracer transport velocities in the axial and the radial directions in the plant stem. The model revealed that the width of the parabolic tail reflected the magnitudes of diffusion and permeation of the tracer in the plant stem.


Assuntos
Imageamento por Ressonância Magnética , Caules de Planta/fisiologia , Transporte Biológico
8.
Magn Reson Imaging ; 15(6): 693-700, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9285809

RESUMO

Zero (ZQ) and double (DQ) quantum 2D chemical shift selective and spin-echo 3D NMR imaging at microscopy resolution, has been applied to the morphological study of silkworm, Bombyx mori, during its metamorphosis. Attention had been focused on the evolution of the internal structure of the insect during its postembryonal life occurring through the larval, pupal and adult development. A major objective of this work was the characterization of the silk glands, responsible for the synthesis and secretion of fibroin and sericin, through the changes of distribution and mobility of water, by imaging the water protons during postembryonal life stages. Moreover, alanine deriving from silk gland proteins was imaged during the last life stage of Bombyx mori.


Assuntos
Bombyx/anatomia & histologia , Espectroscopia de Ressonância Magnética/métodos , Metamorfose Biológica , Microscopia/métodos , Animais , Bombyx/fisiologia , Larva/anatomia & histologia , Larva/fisiologia , Pupa/anatomia & histologia , Pupa/fisiologia
9.
Biochim Biophys Acta ; 1322(2-3): 195-207, 1997 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9452766

RESUMO

31P and 1H MRS high resolution measurements at 4.7 T were carried out in isolated frog (Rana esculenta) gastrocnemius muscle during anoxia to assess, using reference compounds, the concentration of high energy phosphates (approximately P = phosphocreatine (PC) plus adenosinetriphosphate (ATP)), inorganic phosphate (P(i)), phosphomonoesters (PME) and lactate (La): Two sets of measurements were performed, with (p) and without (up) muscle IAA poisoning and the time course of the metabolite concentration changes was described. The rate of phosphocreatine hydrolysis during the first phase of anaerobiosis, when no lactate is accumulated in either case, appears to be greater in p than in up preparations. This finding can be explained with the sizeable accumulation of phosphomonoesters (PME) in the former. The efficiency of anaerobic glycolysis, i.e. the approximately P/La ratio, recalculated taking into account also PME changes, was found to be 1.48 +/- 0.28, a value higher than that obtained by previous chemical measurements and close to the maximum stoichiometric approximately P/La value. Hence, the in vivo substrate of glycolysis, in the resting anoxic frog gastrocnemius, appears to be almost exclusively glycogen.


Assuntos
Glicólise/fisiologia , Músculo Esquelético/metabolismo , Fosfatos/metabolismo , Trifosfato de Adenosina/metabolismo , Anaerobiose , Animais , Hipóxia Celular , Glicólise/efeitos dos fármacos , Iodoacetatos/farmacologia , Ácido Iodoacético , Ácido Láctico/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Fosfocreatina/metabolismo , Rana esculenta
10.
Magn Reson Imaging ; 12(3): 477-86, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8007778

RESUMO

Multi-echo, chemical shift selective, and 3D NMR imaging at microscopy resolution, and CP/MAS 13C NMR spectroscopy have been applied to the chemistry study of oil in oil-rich seeds of Afzelia cuanzensis, a tropical plant belonging to the Leguminosae taxum Caesalpinoideae or Caesalpinaceae.


Assuntos
Espectroscopia de Ressonância Magnética , Sementes/química , Processamento de Imagem Assistida por Computador , Moçambique , Óleos de Plantas/análise
12.
G Ital Cardiol ; 22(3): 293-305, 1992 Mar.
Artigo em Italiano | MEDLINE | ID: mdl-1426772

RESUMO

The results of the present analysis indicate, from 1969 to 1987, a sharp and stable decline in cardiovascular (CVD) mortality in Italians aged 35-74 years (37.6% in males 53.6% in females). These trends were responsible for consistent reductions of total mortality (27.5% and 38% in the two gender groups, respectively), and for the increase of life expectancy. The decrease involved the two major components of CVD mortality, i.e. coronary heart disease (CHD) (23% in males and 44% in females) and cerebrovascular diseases (Stroke) (42.6% in the former and 51% in latter gender group). All these mortality decrements have been higher in the Lombardia Region. Comparing age-adjusted mortality rates in 1968 and 1987, it was possible to estimate that 23,040 deaths were saved in one year among the residents of this northern part of Italy, and the decrease of CHD mortality was responsible for about 30% of the total national decrement of CHD deaths, within comparable age strata. This is attributable both to the higher rates registered at the beginning of the studied period, and to the sharper decline observed. The social impact, in terms of reduction of deaths, was prominent for males. Among the northern male population, the amount of prevented deaths due to CHD and Stroke was equivalent (2072 vs 2172). Data from a MONICA Collaborating Center, located in the region--Area Brianza--, allow us to estimate, for coronary diagnoses reported on death certificates in the 1980s, acceptable levels of accuracy (Cohen's Kappa of .35, with 99% CI .27-.43) and sensitivity (87%). In comparison with earlier estimates carried out in the late 1970s, it is possible to hypothesize an increase of sensitivity over time for certified myocardial infarction diagnoses, which could have contributed to the underestimation of the observed decrements. In dealing with estimates of the reasons for these declines, only suggestions could be addressed because results of specific and comprehensive studies are not presently available. By comparing MONICA data with the results obtained in earlier surveys, it is possible to estimate that about 20 to 30% of the CHD decline, which occurred in the Region, might be attributed to the decrease of in-hospital coronary case-fatality. Moreover, major coronary risk factors (total cholesterol, blood pressure and cigarette smoking) show parallel positive changes, but their contribution in predicting the CHD downfall is difficult to evaluate on the basis of existing data.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Doenças Cardiovasculares/mortalidade , Doença das Coronárias/mortalidade , Adulto , Idoso , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sensibilidade e Especificidade , Fatores Socioeconômicos
13.
Phys Ther ; 70(5): 295-301, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-2333327

RESUMO

The energy cost of walking was measured in 12 patients (age 39-73 years) with hip joint impairment and 10 healthy controls during unassisted walking (2-6 km.h-1) on a level treadmill surface and on a 5% incline. The energy cost of locomotion in most patients increased up to 50% and 70% during level-surface and uphill walking, respectively. This difference between patients and controls was probably due to the increased external mechanical work. The energy cost of walking, although related to pain experienced during walking but not to hip joint range of motion or to joint status evaluated radiographically, provides an additional variable when defining the conditions of disability and functional impairment in individuals with this pathological condition. [Gussoni M, Margonato V, Ventura R, et al: Energy cost of walking with hip joint impairment.


Assuntos
Metabolismo Energético , Articulação do Quadril/fisiopatologia , Instabilidade Articular/fisiopatologia , Locomoção/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Eficiência , Fadiga/etiologia , Fadiga/metabolismo , Feminino , Marcha , Articulação do Quadril/metabolismo , Humanos , Instabilidade Articular/complicações , Instabilidade Articular/metabolismo , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Dor/etiologia , Dor/metabolismo
14.
Physiol Chem Phys Med NMR ; 22(4): 233-40, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2101936

RESUMO

The time dependence of Lactate (Lac), H+, Adenosine-triphosphate (ATP), Phosphocreatine (PCr), Hexose-monophosphate (PME), and Inorganic Phosphate (Pi) levels has been obtained for frog muscle at rest in anaerobic conditions by multinuclear NMR. All information has been collected on the same samples alternatively tuning the probehead on 1H- and 31P-NMR frequencies. ATP, PCr and H+ levels show the same time dependence for all the samples, while PME, Pi and Lac levels vary in time differently from one sample to another. No direct correlation between the Lac appearance and the H+ concentration has been found.


Assuntos
Músculos/metabolismo , Trifosfato de Adenosina/metabolismo , Anaerobiose , Animais , Concentração de Íons de Hidrogênio , Cinética , Lactatos/metabolismo , Ácido Láctico , Espectroscopia de Ressonância Magnética , Fosfatos/metabolismo , Fosfocreatina/metabolismo , Rana esculenta
16.
J Appl Physiol (1985) ; 62(6): 2288-94, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3610925

RESUMO

The maximal instantaneous anaerobic power (w), as determined during a high jump off both feet on a force platform, was measured on eight subjects starting from a resting base line; a base line of steady-state cycloergometric exercise requiring 30, 50, and 70% of individual maximum O2 consumption (VO2max); and a base line of maximal and supramaximal exercise (100 and 120% of VO2max). In addition, w was also measured during the VO2 transients from rest to each of the above work loads. Blood lactate concentration ([Lab]) was determined before and 8 min after the end of each priming load. After the onset of any priming load, w decreases with time reaching in 2 min a steady level that is lower the higher the VO2. For the three lowest work rates, the steady w level is unchanged by increasing the duration of the priming exercise up to 30 min. For low work levels, the decrease of w as a function of VO2 is essentially parallel to that of estimated muscle concentration of ATP ([ATP]). For work levels greater than 60% of VO2max involving a substantial accumulation of lactate, the decrease of w becomes smaller than the estimated drop of muscle [ATP]. This finding is tentatively attributed to an increase of either the mechanical equivalent or of the velocity constant of ATP splitting brought about by the lowering of intracellular muscle pH after lactate accumulation.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Músculos/fisiologia , Esforço Físico , Trifosfato de Adenosina/metabolismo , Adulto , Humanos , Lactatos/sangue , Ácido Láctico , Masculino , Matemática , Contração Muscular , Consumo de Oxigênio
17.
Artigo em Inglês | MEDLINE | ID: mdl-6469791

RESUMO

The PO2 at which hemoglobin is half-saturated with O2 (P50) at 37 degrees C, PCO2 = 42 Torr, measured pH and 2,3-diphosphoglycerate-to-hemoglobin concentration ratio ( [2,3-DPG]/[Hb]) values, Hill's coefficient (n) at rest, and maximal O2 consumption (VO2max) were determined in 11 world-class professional bicycle racers off-season (control, C), after 3 mo of 3 h daily training (preseason, PrS), and after additional 6 mo of competitions (competitive season, CoS). The results indicate that the P50 observed in trained athletes was the same as that of a comparable group of sedentary subjects (Sed) under the same conditions of pH, PCO2, and [2,3-DPG]/[Hb] and was similar to that obtained after "normalization" in respect to pH and the [2,3-DPG]/[Hb]; [2,3-DPG]/[Hb] increased as a function of training from 0.72 to 0.95 (P less than 0.001); the slope of the central portion of the O2 equilibrium curve (OEC) was nearly unaffected by endurance training as indicated by the n value (NCoS = 2.70 +/- 0.08; nSed = 2.65 +/- 0.08); and VO2max increased in the course of training 7 and 9% (P less than 0.001), respectively, when expressed in absolute units or per kilogram body weight. The VO2max predicted on the basis of a computer simulation does not increase significantly as a consequence of the measured rise in [2,3-DPG]. Therefore, the observed increase of VO2max cannot be explained with adaptive changes of the OEC. The present results differ from previous findings reported in other types of athletes.


Assuntos
Ciclismo , Consumo de Oxigênio , Oxigênio/sangue , Esportes , 2,3-Difosfoglicerato , Adulto , Ácidos Difosfoglicéricos/sangue , Frequência Cardíaca , Humanos , Concentração de Íons de Hidrogênio , Masculino , Músculos/metabolismo , Oxiemoglobinas/metabolismo , Pressão Parcial , Resistência Física , Esforço Físico
19.
Boll Soc Ital Biol Sper ; 58(19): 1275-81, 1982 Oct 15.
Artigo em Italiano | MEDLINE | ID: mdl-7159521

RESUMO

The measurement of oxygen uptake on a breath by breath basis has been obtained coupling the respiratory mass spectrometer (MS) for O2 and CO2 measurements, the pneumotachograph (PN) for flow rate and volume estimates to the computer. MS and PN output has been sampled at 50 Hz during the respiratory circle and each corresponding area has been integrated. From the volume of expired O2 subtracted from the amount of O2 inspired, O2 uptake of each breath has been obtained. Accordingly CO2 production and related respiratory variables have been assessed. O2 uptake referred to unit time calculated breath by breath has been compared to O2 consumed measured by open circuit method at steady state (from the 5th to the 6th min of exercise) in 5 male subjects pedalling on a bicycle ergometer in work rate range of 150-170 kpm/min. The difference of O2 consumption with the two methods was on the average less than +/- 5%. The proposed method is particularly suitable for O2 uptake kinetics at the onset and offset of exercise.


Assuntos
Computadores , Testes de Função Respiratória/instrumentação , Humanos , Masculino , Consumo de Oxigênio , Esforço Físico , Testes de Função Respiratória/métodos
20.
Boll Soc Ital Biol Sper ; 58(8): 457-61, 1982 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-7093052

RESUMO

Cardiac output, heart rate, arterial pressure and indirect left ventricular oxygen consumption have been measured in three subjects during isometric contractions (50-170 kg) of the plantar flexors until fatigue was reached and during walking on a treadmill. Cardiac output was linearly related to VO2 for both exercises. However, for the same VO2, Q was four times higher during isometric effort than during walking. In the last 15 s of static tasks, HR was linearly increasing to VO2 and AP reached values of 160 and 125 Torr (systolic and diastolic respectively) independently of VO2. For comparable VO2 in static and isotonic exercises myocardial O2 uptake was doubled during isometric rather than during the isotonic exercise.


Assuntos
Débito Cardíaco , Coração/fisiologia , Esforço Físico , Pressão Sanguínea , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio
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