Preconditioning refers to exposure to brief episodes of potentially adverse stimuli and protects against injury during subsequent exposures. This was first described in the heart, where episodes of ischemia/reperfusion render the myocardium resistant to subsequent ischemic injury, which is likely caused by reactive oxygen species (ROS) and proinflammatory processes. Protection of the heart was ...

The aim of the study was to assess effects of acetazolamide in prevention of acute mountain sickness (AMS) and on overnight oxygenation, in patients with asthma treated at the altitude of 3,200 m. Sixteen patients with asthma, 6 males and 10 females, mean age 32 yrs, were first investigated at low altitude (760 m). They presented with mild airways obstruction, normal arterial blood gases, and n...

To investigate the influence of hypoxia during the early stage of incubation on embryonic developmentand hatching events, and consequently on incidence of ascites in broiler chickens, one thousand fertile eggswere incubated in two commercial incubators. Half the eggs were incubated in a low altitude incubator untilhatched. The second half were incubated in a high altitude incubator until day 10...

The present study evaluated the effects of acute high altitude stress induced physiological and neurobehavioral changes and the possible involvement of nitric oxide (NO) in the regulation of such effects in rats. High altitude was simulated in a high altitude/hypoxia chamber and the effects of such stress and its modulation by NO-ergic agents were assessed on plasma corticosterone, anxiety and ...

Platelet aggregation is the key process in primary hemostasis. Certain conditions such as hypoxia may induce platelet aggregation and lead to platelet sequestration primarily in the pulmonary microcirculation. We investigated the influence of high-altitude exposure on platelet function as part of a larger study on 30 subjects with a history of high-altitude pulmonary edema (HAPE) and 10 healthy...

Many elite athletes believe that training at altitude improves sea level performance. Yet the scientific evidence, such as it is, would seem to refute this, suggesting that the athlete’s trust may be misplaced. However, these scientific studies do not exclude the possibility that altitude training might produce an effect (<1%) that is too small to be detected by current research methods, but wh...

In the mountain climbing community, conventional prevention of altitude mountain sickness (AMS) relies primarily on a formal acclimatization period. AMS symptoms during mountaineering climbs are managed with medication, oxygen and minor recompression (1524-2438 m altitude) using a portable chamber, such as the Gamow Bag. This is not always an acceptable therapy alternative in a predominantly el...

High-altitude tourism is increasingly frequent, involving also subjects with manifest or subclinical coronary artery disease. Little is known, however, on the effects of altitude exposure on factors affecting coronary perfusion. The aim of our study was to assess myocardial oxygen supply/demand ratio in healthy subjects during acute exposure at high altitude and to evaluate the effect of acetaz...

Acetazolamide can be taken at sea level to prevent acute mountain sickness during subsequent altitude exposure. Acetazolamide causes metabolic acidosis at sea level and altitude, and increases SaO2 (arterial oxygen saturation) at altitude. The aim of the present study was to determine whether acetazolamide impairs muscle endurance at sea level but not simulated altitude (4300 m for <3 h). Six s...

This paper presents the results of a numerical study investigating the effects of low-altitude shortduration plasma heating episodes t .... h a• ho,-iztmta! frictional heating) ,,,, t .... i•nt heavy i,,,, outflows from the polar ionosphere using a time-dependent model. In a previous set of calculations, where the effects of high-altitude transient heat sources were investigated, the low-altitu...