Aconcagua

Acute mountain sickness (AMS) is a group of non-specific symptoms, seen in subjects that ascend from low to high altitude too quickly, without allowing sufficient time to acclimatize. Usually it is self-limiting, but the severe forms (pulmonary and cerebral edema) can be fatal. Exaggerated hypoxemia at rest is related to later development of AMS but its predictive value is limited. Since exercise at altitude induces greater hypoxemia and symptoms, we postulated the predictive value of a simple exercise test to prognosticate severe AMS...

AIMS: To evaluate the impact of high altitude on cardiac morphology and function in patients with coronary artery disease (CAD) and healthy controls. METHODS AND RESULTS: Eight patients with a history of acute myocardial infarction [53 +/- 8 years, left ventricular (LV) ejection fraction 54 +/- 6%] and a low risk score were compared with seven healthy controls (41 +/- 16 years) during the Dutch Heart Expedition 2007 at the Aconcagua (6960 m) in Argentina. An exercise test and echocardiography were performed at sea level and at base camp (4200 m)...

The purpose of this work was to correlate the presence of brain abnormalities on magnetic resonance imaging (MRI) with changes in hematological variables and the presence of mountain sickness in 21 mountain climbers involved in two different expeditions to high mountains, Everest and Aconcagua, without supplementary oxygen and recommended acclimatization for this kind of activities. The climbers underwent medical examination, hematological studies, electrocardiogram and MRI of the cerebrum. Wilcoxon signed-rank test was used to evaluate the changes in hematocrit, hemoglobin, red blood cells, iron and ferritin...

Populations of the invasive Frankliniella occidentalis (Pergande) are serious pests of agricultural crops in the Aconcagua Valley of central Chile. An extensive survey was conducted of 55 plant species in 24 families to identify plant hosts of F. occidentalis and to determine its relative abundance on each host during each season. A more intensive study was conducted on selected plant species serving as reproductive hosts to determine the population dynamics of F. occidentalis and to evaluate the potential importance of Orius species and other natural enemies for controlling F...

Simazine is a s-triazine herbicide that has been applied worldwide for agriculture. This herbicide is the second most commonly detected pesticide in surface and groundwater in the United States, Europe and Australia. In this study, simazine adsorption behaviour was studied in two agricultural soils of the Aconcagua valley, central Chile. The two studied soils were soil A (loam, 8.5% organic matter content) and soil B (clay-loam, 3.5% organic matter content). Three times higher simazine adsorption capacity was observed in soil A (68...

BACKGROUND/OBJECTIVE: We examined the changes in ventilation during sleep at high altitude using the LifeShirt monitoring system on 2 climbers who were attempting to summit Mount Aconcagua (6956 m). METHODS: Prior to the summit attempt, we measured cardiovascular and pulmonary function at 401 m (Rochester, MN) and gathered respiratory and cardiovascular data during sleep using the LifeShirt monitoring system with exposure to normobaric normoxia and normobaric hypoxia (simulated 4300 m)...

PURPOSE: There are only anecdotal and small reports on brain systematic magnetic resonance imaging (MRI) studies in mountain climbers. The purpose of our work is to study the risk of brain lesions in mountain climbers by means of conventional MRI and magnetic resonance spectroscopy (MRS). METHODS: We recruited 35 climbers consecutively (12 were professional and 23 were amateur) in 4 expeditions without supplementary oxygen: 12 professionals and one amateur went up to Mt...

To investigate the determinants of acute mountain sickness (AMS) and of summiting in expedition-style mountaineering, 919 mountaineers (15.4% female) leaving Aconcagua Provincial Park at the end of an expedition to Mt. Aconcagua (6962 m) via the normal route were retrospectively evaluated by questionnaires. Symptoms of AMS were reported from the day when mountaineers felt worst. The prevalence of AMS, defined as a Lake Louise Score (self-assessment) > 4, was 39%. Low AMS scores were associated with faster ascent rates...

No abstract text is available yet for this article.

In the 5th Region, located in central Chile, infrastructure projects are being implemented in order to increase the capacity to treat and dispose of sewage. In order to analyse the sludge management alternatives the ORWARE model was used. The research project was divided in two stages: in the first stage, the sewage and sludge management strategies to be compared as well as the objectives were established. The management alternatives chosen were for chemical or biological treatment of sewage while for sludge the management alternatives were based on digestion, composting or lime stabilisation...

Evaluation of desinsectation programs carried out in the two Health Services from the V Region, was undertaken by comparing serologic prevalences of T. cruzi infection age groups exposed to the risk of infection in rural areas during the antivectorial campaign activities (1982 vs 1995). Thus, were studied 2,193 blood samples from children under 10 years of age, proceeding from six chagasic endemic provinces in which antitriatomic domiciliary insecticide sprayings had been performed. Indirect hemagglutination and ELISA tests were carried out to each of the blood samples...

PURPOSE: To study the effect of high-altitude exposure on visual acuity after myopic laser in situ keratomileusis (LASIK). SETTING: Aconcagua, Mendoza, Argentina. METHODS: In the early postoperative period after uneventful myopic LASIK, 2 physicians prospectively assessed their visual acuity during an ascent of Aconcagua (22841 feet). The distance uncorrected visual acuity (UCVA) and peripheral oxygenation were measured at approximately every 2000 feet of altitude...

UNLABELLED: Persons at extreme altitudes are known to experience disturbances in the regulation of ventilation and sleep structure. However, except for simulated studies using the decompression chamber, only single events of sleep or ventilation were measured so far in field studies up to an altitude of 5800 m. Modifying a portable sleep lab (Vitalog HMS 5000), we were able to conduct 7 channel polygraphy on our ascent to the Aconcagua up to an altitude of 6400 m. METHODS: In 6 climbers (age 38-62 y, 1 f, 6 m), ECG, EOG, SaO2, chest and abdominal movements, breathing and snoring sounds, body position, nasal and oral airflow were measured 4 weeks prior to the expedition at an altitude of 500 m, at base camp (4200 m) and in 3 climbers at 6400 m (2nd base camp) at the Aconcagua mountain...

No abstract text is available yet for this article.

Retinal hemorrhages appear to be a frequent, though often unappreciated, occurrence in unacclimated climbers experiencing prolonged exposure to altitudes above approximately 3,658 meters (12,000 ft), heights frequently attained by American moutaineers. This condition has not received attention in the ophthalmologic literature, though several reports of retinal and vitreous hemorrhages have appeared in nonophthalmologic journals. Of six surviving members of a climbing expedition of Mt. Aconcagua, four had retinal hemorrhages...