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Results 501 - 550 of 804
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Kramer M R - - 1996
Patients with advanced chronic obstructive lung disease often require oxygen supplementation, which has been shown to increase survival but requires a device such as an oxygen tank and tubing. The inspired partial pressure of oxygen depends on barometric pressure, which is related directly to altitude. At the Dead Sea, located ...
Young A J - - 1996
This study investigated whether autologous erythrocyte infusion would ameliorate the decrement in maximal O2 uptake (VO2max) experienced by lowlanders when they ascend to high altitude. VO2max was measured in 16 men (treadmill running) at sea level (SL) and on the 1st (HA1) and 9th (HA9) days of high-altitude (4,300 m) ...
Gippenreiter E - - 1996
The countries of the former Soviet Union have a long history of studies in high-altitude medicine and physiology, but much of the information is difficult to obtain in the West because of the inaccessibility of the journals and the lack of familiarity with the language. The purpose of present review ...
Le Gallais D - - 1996
The pathophysiological process of exercise-induced death in subjects with sickle cell trait (SCT) remains unclear. Concerning the cause of death, authors have suggested stressful environmental conditions such as altitude, heat and humidity, or abnormal patient conditions such as deconditioning, fatigue, and disease. These conditions are thought to lead to hypoxemia, ...
Jensen J B - - 1996
The fractional increase in cerebral blood flow (CBF) velocity (VCBF) from the control value with 5-min steps of isocapnic hypoxia and hyperoxic hypercapnia was measured by transcranial Doppler in six sea-level native men before and during a 5-day sojourn at 3,810 m altitude to determine whether cerebral vasoreactivity to low ...
Guo B Z - - 1996
Kernels of corn population GT-MAS:gk, resistant to aflatoxin B1 production by Aspergillus flavus, and susceptible Pioneer hybrid 3154 were tested for aflatoxin when incubated under different relative humidities (RH). High aflatoxin levels were not detected in either genotype at RH < 91%. Resistance in GT-MAS:gk was consistent across all RH ...
Conkin J - - 1996
One consequence of the NASA tissue ratio (TR) model is that calculated probability of decompression sickness [P(DCS)] is constant in tests at different ambient pressures so long as the ratio of P1N2 to P2 is the same in each test; P1N2 is N2 pressure in the 360 minute half-time compartment, ...
Roberts A C - - 1996
To test the hypothesis that altitude exposure increases glucose utilization and that this increment is mediated by a beta-adrenergic mechanism, the effects of hypobaric hypoxia and beta-blockade on glucose rates of appearance (Ra), disappearance (Rd), oxidation (Rox), and leg uptake [G = 2(arteriovenous glucose difference)(1 - leg blood flow)] were ...
Jeng W L - - 1996
One of the major industries in southern Taiwan is pigfarming along the Kaoping River; some two million animals are being raised along the river banks. Excretions from pigs, treated and untreated, are discharged directly into the river and eventually carried to the sea. Twenty-four surface sediments and one sediment core ...
Steinacker J M - - 1996
Hypoxic ventilatory response (HVR) was examined before and after acclimatization to high altitude. Transient hyperoxic switches according to Dejours's technique were used to examine the contribution of HVR to the hyperpnoea of increasing exercise intensities. Ten mountaineers were exposed to hypoxia (oxygen fraction in inspired gas. F1O2 = 0.11, 79 ...
Burtscher M - - 1996
After more than 25 years of research of altitude training (AT) there is no consensus regarding either the training programme at altitude or the effects of AT on performance at sea level. Based on a review of the research work on AT, we investigated combined base training and interval training ...
Kayser B - - 1996
In acclimatized humans at high altitude the reduction, compared to acute hypoxia, of the blood lactate concentration (la) at any absolute oxygen uptake (VO2), as well as the reduction of maximum la (lamax) after exhaustive exercise, compared to both acute hypoxia or normoxia, have been considered paradoxical, and these phenomena ...
Steinacker J M - - 1996
Studies were made of pulmonary diffusion capacity and oxygen transport before and after an expedition to altitudes at and above 4900 m. Maximum power (Pmax) and maximal oxygen uptake (VO2max) were measured in 11 mountaineers in an incremental cycle ergometer test (25W.min-1) before and after return from basecamp (30 days ...
Naughton M T - - 1995
Hypobaric hypoxemia is experienced by passengers during commercial aircraft flight. In order to assess the extent of hypoxemia and to test whether hypobaric hypoxia can be accurately estimated at sea level, the results of the normobaric hypoxia altitude simulation test (N-HAST) were compared with those of the hypobaric hypoxia altitude ...
Wood R J - - 1995
Anecdotal evidence suggests that the 610 m altitude of the Australian Institute of Sport in Canberra may affect athletic performances, despite the lack of theoretical evidence to support this. Also, the lower air resistance at altitude could alter the mechanics of air-braked exercise ergometers. Therefore, this study compared performance on ...
Porcelli M J - - 1995
Acute mountain sickness (AMS) affects, to varying degrees, all travelers to high altitudes (elevations greater than 5280 feet). In a small percentage of patients, AMS can lead to high-altitude pulmonary edema (HAPE) or high-altitude cerebral edema (HACE). Symptoms of AMS range from a combination of headache, insomnia, anorexia, nausea, and ...
Rao A R - - 1995
Three measures of reciprocity, denoted s2, s3, and s4, that are applicable to both simple and weighted networks are considered here. By reciprocity I mean symmetry or mutuality of ties between different vertices of the network. These measures have simple formulas except in some extreme situations and can be used ...
Hohenhaus E - - 1995
Reduced tolerance to high altitude may be associated with a low ventilatory and an increased pulmonary vascular response to hypoxia. We therefore, examined whether individuals susceptible to acute mountain sickness (AMS) or high altitude pulmonary oedema (HAPE) could be identified by noninvasive measurements of these parameters at low altitude. Ventilatory ...
Allegra L - - 1995
It is well-known that many patients with asthma undergo clinical improvement during a stay at high altitude. At high altitude, the atmospheric and climatic conditions (such as hypoxia, cold and dry air inhalation) could modify the bronchial responsiveness in asthmatics. Our study was designed to assess the difference in bronchial ...
Coote J H - - 1995
Acute mountain sickness (AMS) has long been recognised as a potentially life-threatening condition afflicting otherwise healthy normal individuals who ascend rapidly to high altitude where the partial pressure of oxygen (pO2) in the air is reduce. The symptoms of AMS (e.g. headache, poor appetite and nausea, fatigue and weakness, dizziness ...
Savard G K - - 1995
The purpose of this study was to assess the effects of acclimatization to extreme altitude on the cardiovascular system, using vagal and adrenergic blockade and acute restoration of normoxia during exercise to maximum with one and two legs. Fourteen climbers on an expedition to the Himalayas were studied at a ...
Jaworska J S - - 1995
The acute toxicity of aliphatic and aromatic mono and diesters in two eucaryotic organisms was compared. The test systems were the static 2-d Tetrahymena pyriformis 50% population growth impairment (IGC50(-1)) assay, and the flow-through 4-d Pimephales promelas 50% mortality (LC50(-1)) assay. In ciliates, esters act via the nonpolar narcosis mechanism ...
Mazzeo R S - - 1995
This investigation examined the relationship between alterations in plasma norepinephrine associated with 21 days of high-altitude exposure and muscle sympathetic activity both at rest and during exercise. Healthy sea level residents, divided into a control group (n = 5) receiving a placebo or a drug group (n = 6) receiving ...
Davis H Q - - 1995
This study determined if visual performance with Aviator Night Vision Imaging System (ANVIS) was degraded by the degree of hypoxia experienced at the maximum flight altitude currently authorized (U.S. Army regulations) without supplemental oxygen. Visual acuity and contrast sensitivity with ANVIS were tested under simulated starlight and full moonlight illumination ...
Favier R - - 1995
Maximal O2 uptake (VO2max) was determined on a bicycle ergometer in chronic hypoxia (CH) and during acute exposure to normoxia (AN) in 50 healthy young men who were born and had lived at 3,600 m altitude (La Paz, Bolivia). VO2max was significantly improved (approximately 8%) by AN. However, the difference ...
Artal R - - 1995
OBJECTIVE: The purpose of this study was to compare maternal cardiopulmonary and fetal responses of lowlander pregnant women in the third trimester to exercise at sea level and at an altitude of 6000 feet. STUDY DESIGN: Seven women at 33.86 +/- 1 weeks' gestation performed a symptom-limited maximal exercise test ...
Terasawa K - - 1995
To examine cardiopulmonary function during exercise in a mountainous region at moderate altitude, we measured cardiac frequency, oxygen consumption (VO2), and percentage arterial hemoglobin oxygen saturation (%SaO2) before and after a bicycle race with a starting point at 638 m and finishing point at 1980 m. The time required to ...
Nimmo M A - - 1995
A simple study monitoring altitude acclimatization, which is not intrusive to the athlete's training, is described. Particular attention is drawn to the change in production of lactate in response to steady state exercise, before and after altitude. The results suggest that a more thorough assessment of aerobic ability at altitude ...
Gunga H C - - 1995
For over 52 years, the work of Nathan Zuntz (1847-1920) covered an amazingly wide spectrum of research fields; metabolism, nutrition, respiration, blood gases, exercise, and high altitude physiology were the main themes. Zuntz achieved fame for his invention of the Zuntz-Geppert respiratory apparatus in 1886 and the first Laufband (treadmill) ...
West J B - - 1995
Recently there has been increasing commercial activity at altitudes of 3500-6000 m. Examples include new mines in northern Chile at altitudes of about 4500 m. Because the workers come from sea level, intolerance of the high altitude is a major problem. This degree of hypoxia reduces work capacity, mental efficiency ...
Kashimura O - - 1995
We examined the effects of exercise training on pulmonary arterial blood pressure (Ppa) and on adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (GMP) concentrations in lung tissue at rest and during exercise under hypoxic conditions in catheter-implanted rats. Male Wistar rats were divided into an exercise-trained group (ET, n ...
Takeoka M - - 1995
Physiological changes were investigated in the cardio-respiratory function of competitors in a bicycle race which involved not a flat course but ascending a mountain, from 1400 m to 2800 m. Heart rate throughout the race, arterial oxygen saturation and pulmonary function before and after the race of well trained competitors ...
Saito S - - 1995
The recent expansion in the geographical areas open to human activity has made it desirable to have an objective method to evaluate the degree of high-altitude acclimatization. In this study, we measured the arterial oxygen saturation value at rest and just after exercise in healthy high-altitude trekkers using a transportable ...
Capelli C - - 1995
The present world record for 1 h unaccompanied cycling (55.291 km) was set by T. Rominger in November 1994 at sea level (Bordeaux, France). However, maximal aerobic cycling performances can be expected to increase at altitude because, for a given air temperature, air density decreases more than VO2max. The combined ...
Shih Y F - - 1995
Visual-training methods in management of myopia are suggested as possibly leading to normal vision or an improvement in the refractive state. The purpose of this work was to investigate the hypothesis that a Qi-Qong ocular exercise improves visual function by training the accommodation bias. Variations of pupil size, accommodative amplitude, ...
Niu W - - 1995
The physiological response to submaximal and maximal exercise was assessed in lowlanders and Tibetans at low (500 m above sea level) and high altitude (HA, 3,680 m). The times spent at HA by the lowland migrators was 8 days (n = 60), 7 months (n = 60, same group), 15 ...
Takebayashi T - - 1995
We investigated the effect of local injections of danazol suspension (DZS) into the uterine cervix. In the cervix, danazol (DZ) reached high concentrations 1 and 4-6 h after injection; then it decreased. In the endometrium, the DZ level reached a peak 1 h after injection, and then declined. On the ...
Bijl D - - 1994
BACKGROUND: In order to evaluate a pulmonary rehabilitation program (PRP) at moderate altitude (1560 m) 62 patients with obstructive lung disease were asked to participate; 37 patients completed a 1-year follow-up at sea level, and 25 patients dropped out. The exercise training program lasted for 10 weeks and consisted of ...
Beran R F - - 1994
BACKGROUND: To ensure optimal performance, it is imperative to properly maintain the condition of ophthalmic diamond scalpels. Refractive surgeons are often confronted with conflicting cleaning recommendations from manufacturers. The problem encountered is to maximize cleaning while minimizing trauma to the diamond to maintain its longevity. METHODS: The author describes a ...
Noel-Jorand M C - - 1994
Respiratory sensation was studied in European low-landers at an altitude of 4382 m after a helicopter flight in order to investigate the acute and prolonged effects of high altitude hypoxia. At rest the ability to detect four inspiratory resistive loads can be used to create a sensitivity index P(A) without ...
Ge R L - - 1994
To examine the hypothesis that the pathway of adaptation to high altitude in natives differs considerably from that in newcomers, we measured maximal O2 uptake (VO2max), minute ventilation, anaerobic threshold (AT), blood lactate, and blood gases during maximal exercise in 17 lifelong Tibetan residents and 14 acclimatized Han Chinese newcomers ...
Pearl W - - 1994
The electrocardiograms of 28 volunteers with sickle cell trait were compared to those of 28 control subjects. Tracings were recorded at rest, at peak exercise, at simulated sea level, and at a simulated altitude of 4,000 m. No differences between the subjects with sickle cell trait and control subjects were ...
Al-Hajjaj M S - - 1994
In high altitude areas, inspired atmosphere oxygen decrease proportionally to the vertical distance from sea level. Population in these areas some adaptive mechanisms to cope with the relatively hypoxic environment. This study compares populations who live in highland areas (2500 meters above sea level) with those in lowland areas (close ...
Kumar K V - - 1994
A two-period, crossover trial was conducted in the hypobaric chamber on human subjects to compare the influence of inflight exercise (experimental) and restricted activity (control) on altitude decompression sickness (DCS) during simulated extravehicular activities. Out of 39 pairs (total of 78 exposures), 4 cases of DCS occurred under control and ...
Fulco C S - - 1994
The purpose of this study was to determine if caffeine (CAF) could enhance exercise performance at high altitude (HA). Eight males (17 to 24 years) performed two submaximal endurance tests to exhaustion (ETX) while cycling at approximately 80% of their altitude-specific maximal aerobic power during each of three phases: 1) ...
Sancier K M - - 1994
Electroacupuncture According to Voll (EAV) was used to monitor the effects of qigong practice on therapeutic balancing of subjects. In EAV the electrical conductance of the skin above individual acupuncture points is measured using low voltage and current. Diagnosis depends on measuring the relative electrical conductance and its time dependence. ...
Martínez-Ballarín E - - 1994
High altitude has always intrigued physiologists because of the remarkable ability of man to adapt to the hostile environment. Despite numerous studies examining the physiological alterations occurring during exercise after exposure to hypoxia and the adaptative effects of sustained residence at altitude, several issues remain unresolved. The aim of investigation ...
Rawal S B - - 1994
Using radioactive iodine, the effect of 1 month's yogic exercises has been investigated on the thyroid function of subjects resident at sea level (SL) specially after their exposure to high altitude (HA). The results have been compared with a group of SL subjects who underwent physical training (PT) exercises for ...
Hansen J M - - 1994
The mechanism of proteinuria at high altitude is unclear. Renal function and urinary excretion rate of albumin (Ualb) at rest and during submaximal exercise and transcapillary escape rate of 125I-labeled albumin (TERalb) were investigated in 12 normal volunteers at sea level and after rapid and passive ascent to 4,350 m. ...
Slooten J - - 1994
This study describes habitual physical activity (HPA) of Bolivian boys living at different altitudes and from different socioeconomic status. The boys were living at high altitude (HA) in La Paz (4000 m) and at low altitude (LA) in Santa Cruz (400 m). At both altitudes samples of 10- to 12-year-old ...
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