Effects of acute and sub-acute hypobaric hypoxia on oxidative stress: a field study in the Alps.

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.

Quantitative analysis of anaerobic metabolism in resting anoxic muscle by 31P and 1H MRS.

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.

Effects of exercise on maximal instantaneous muscular power of humans.

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)

Solid state and microscopy NMR study of the chemical constituents of Afzelia cuanzensis seeds.

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.

Application of NMR microscopy to the morphological study of the silkworm, Bombyx mori, during its metamorphosis.

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.

Magnetic resonance imaging of molecular transport in living morning glory stems.

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.

1H NMR spin-spin relaxation and imaging in porous systems: an application to the morphological study of white portland cement during hydration in the presence of organics.

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.

Energy cost of walking with hip joint impairment.

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.

[Transcatheter closure of patent ductus arteriosus using the Amplatzer duct occluder: initial results and mid-term follow-up]. / Cierre percutáneo del ductus arterioso persistente con dispositivo de Amplatz: resultado inmediato y seguimiento a medio plazo.

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.

[Percutaneous closure of atrial septal defect with the Amplatz device: initial result and mid-term follow-up]. / Cierre percutáneo de la comunicación interauricular mediante dispositivo de Amplatz: resultado inicial y seguimiento a medio plazo.

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.

NMR monitoring of the anaerobic metabolism of frog muscle at rest.

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.

Levantamento etnobotânico de plantas medicinais na cidade de Ipameri - GO / Ethnobotanical survey of medicinal plants in Ipameri City - Goiás State

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.

[Acquisition and elaboration of respiratory parameters by the use of analytical instruments with an electronic calculator]. / Acquisizione ed elaborazione di parametri respiratori mediante accoppiamento di strumenti d'analisi con calcolatore elettronico.

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.

A simple method for measuring oxygen uptake on a single breath basis.

A simple method for calculating breath by breath O2 uptake by the conventional open circuit method is described. Each expiratory volume is collected in a collapsible bag (4 1 capacity) surrounded by a rigid box connected to a spirometer. A system of tubes with two solenoid valves operated by a manual switch allows the collection of air into the bag, during expiration, and its emptying by a vacuum pump during inspiration, respectively. The sampling line of a fast responding O2 and CO2 analyzer, together with temperature and pressure probes are inserted into the tube connecting the bag to the vacuum. The expired volume is therefore recorded (by the spirometer output) during expiration and its composition analyzed during the immediately following inspiratory phase, thus allowing gas exchange measurements to be performed on each single breath. VO2 measured by this method at steady state over periods of about 1 min yields substantially the same values as obtained by standard open circuit method (average ratio = 1.01). Ventilations up to 150 l/min (ATPS) and respiratory rates up to 60/min can be easily followed. The simplicity of VO2 calculation, and the very limited dead space of the system (about 70 ml, downstream the expiratory valve), make this method particularly suitable for determining VO2 kinetics at the onset and offset of exercise.

Blood O2 affinity and maximal O2 consumption in elite bicycle racers.

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.

[Kinetics of adjustment of cardiac output to muscular exertion]. / Cinetica dell'adeguamento della gettata cardiaca al lavoro muscolare.

The kinetics of oxygen uptake (VO2), cardiac output (Q), and heart rate (HR) were studied in three healthy male subjects during onset of exercises up to 750 kpm/min. VO2 was measured on a single breath basis, Q by CO2-N2 rebreathing method at 30" intervals from time 0 to 6 min of exercise, and HR beat by beat. In the transition from rest to exercise, the increase of Q and VO2 follows a single exponential function, while h. r. a double exponential. Average half times of Q and VO2 during the onset of exercise are about 18" and 26" respectively. Q changes seem to anticipate VO2 changes at the first 15-45 s of exercise, while thereafter a proportional increase is observed. This non-linear increase of Q to VO2 at the beginning of exercise may presumably be due to a neurogenic control of h.r. and hence of Q from receptors at muscular level.