Shared Science - Wilderness & Environmental Medicine
WEM and The Journal of Special Operations Medicine (JSOM) participate in a shared science program. This opportunity is made possible through a reciprocal partnership between the journals. Click here to see the JSOM articles selected for WEM readers, please visit:
Abstracts from the 6th Chronic Hypoxia Symposium, October 8–15, 2016, La Paz, BoliviaEvery two years the Chronic Hypoxia Symposium is carried out in order to gather scientists from around the globe to present their work and discuss aspects of chronic exposure to hypoxia. The first three symposia, The Effect of Chronic Hypoxia on Diseases at High Altitude, were held in La Paz, Bolivia at 3510 m, the “shrine of hypoxia” and location of the High Altitude Pulmonary and Pathology Institute (IPPA), the first high-altitude clinic in the world, created on July 9th, 1970 by the late Prof.
The Road to “Defeating Hypoxia” is a Timely Exposure to Chronic HypoxiaAcute exposure to hypobaric hypoxia can give rise to acute mountain sickness, and in some severe cases, high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE), that can sometimes lead to the loss of life. However, once the acute phase evolves into gradual adaptation to a fixed “chronic hypoxia” altitude, following the Adaptation to High Altitude Formula (adaptation to high altitude = time / altitude), the organism does remarkably well. Life under chronic hypoxia, where an optimal hematocrit is reached for every fixed altitude, following a logarithmic curve in relation to time, is practically as normal as that at sea level.
Interindividual Differences in the Adaptive Response of the Lung to HypoxiaThe adaptive response of the lung to hypoxia is dominated by the risk of potential development of lung edema on one side, and, on the other, by the need to develop an adaptive response allowing to preserve the oxygen diffusion-transport function. The edemagenic condition relates to the increased cardiac output and microvascular permeability. The rigidity of the extravascular interstitial matrix represents the main mechanism to resist edema formation: due to this peculiar feature, the increase in microvascular filtration leads to a corresponding remarkable increase in interstitial pressure that strongly buffers filtration.
Interindividual Differences Concerning the Oxygen Diffusion-Transport Function in the LungThe oxygen diffusion/transport function is accomplished at the level of the air blood-barrier. Diffusion occurs through the surface of the air-blood barrier (ABB) and of the red blood cells (RBC). Diffusion is therefore directly proportional to the overall extension of the alveolar surface and to the external surface of the RBC; conversely, lung diffusion is inversely proportional to the thickness of the ABB and of the RBC cellular membrane. The transport function occurs through the RBC flow through lung capillaries carrying oxygen bound to hemoglobin.
Potential Application of Cerium Dioxide Nanoparticles for Acute Pneumonia TreatmentCerium dioxide nanoparticles (CeO2 NP) have antioxidant properties and also can alter membrane potential in mitochondria influencing cell respiration. In this study we check the idea that CeO2 NP adsorbed on the silicon base has counter inflammatory, antioxidant and metabolic effects and can be possibly applied in pneumonia treatment.
Life in High-Altitude ConditionsI have always accepted and endorsed both Prof. Dr. Gustavo Zubieta-Castillo (Sr) and Prof. Dr. Gustavo Zubieta-Calleja (Jr) whenever they mentioned that life is possible on top of Mt Everest. I never doubted. I have a lot of supporting evidence which I wish to share with the rest of the world, during this meeting at very high altitude in Chacaltaya (5230 m) where I deliver my talk for the second time. Life does exist at extreme conditions of heat, pressure, temperature, radiation etc. We have functional life at the deepest part of the sea and at very high altitude.
Rearrangement of Neuroendocrine Systems in the MountainsThe aim of this research was to study the functional state of the anterior pituitary, thyroid, adrenal, and reproductive glands and their relationship with chronic exposure to high altitude. Studies were conducted in high altitudes inhabitants of the Tien-Shan (1200 m, 2800 m, 3600 m). Adrenocorticotropic hormone (ACTH), cortisol, catecholamines, thyroid, and sex hormones were determined by immunosorbent and spectrofluorometric methods. Normal hormone levels for sea level inhabitants were used for comparison.
Why is it Not Possible to Predict, Through Tests at Sea Level, Who Will Have AMS?Some people do not present AMS on several altitude exposures, however, unexplainably, they may have it occasionally. Several tests have been tried in order to determine who will have AMS, however, none to date are able to achieve with absolute certainty who will get AMS. Some tests include having subjects breathe a hypoxic mixture. Others have created exercise protocols with exposure to hypoxia and some other techniques. However, none have been successful. We have successfully diagnosed and treated patients with AMS of different intensity, over many years of work at high altitude, some having undiscovered pathologies that became evident on exposure to high altitude.
Low Altitude Peripheral Edema (LAPE): The Opposite of HAPE or HACEMillions of permanent high-altitude residents, born at high altitude, living normal lives, practicing sports, sleeping well, reproducing, and enjoying entertainment, occasionally descend to sea level, for work or leisure. This is a change where the organism perfectly adapted to chronic hypoxia is suddenly exposed to a hyperoxic environment and needs to adapt to the new circumstance. Although no alarming symptoms and signs such as those that can be seen in acute mountain sickness exist like headaches, nausea, or vomiting, there are signs that show evident changes in the body.
Rebuilding of Carbohydrate and Lipid Metabolism Under Hypoxia: Regularities and Therapeutic PossibilitiesPreviously, we have found that the effects of chronic (staying in midlands) or moderate periodic hypoxia as well as hypoxic preconditioning is accompanied by beneficial refbuilding in lipid and carbohydrate metabolism in human and animals: a reduction of total cholesterol and its fractions in blood plasma, a hypoglycemic reaction or normalization of elevated blood glucose, and a decrease of impaired glucose tolerance. This metabolic rebuilding has a phase character during the adaptation to hypoxia and following deadaptation.
Modification and Further Applications of the Adaptation to High Altitude FormulaAdaptation to high altitude is fundamental for life to go on. It is a time and altitude dependent phenomena, because the organism needs the adequate time to build the defense mechanisms to face environmental changes. Quoting the late Gustavo Zubieta-Castillo: “The organic systems of human beings and all other species tend to adapt to any environmental change and circumstance within an optimal period of time, and never tend towards regression which would inevitably lead to death.”
Neural Mechanisms Involved in Autonomic and Respiratory Changes in Rats, Submitted to Short-Term Sustained HypoxiaHumans ascending to high altitudes are submitted to sustained hypoxia (SH), activating peripheral chemoreflex with several autonomic and respiratory responses. We analyzed the effect of short-term SH (24 hours, FIO210%) on the cardiovascular parameters in non-anesthetized rats and on the processing of cardiovascular and respiratory reflexes using in situ and in vitro preparations. SH produced hypertension in awake rats and increased the basal sympathetic activity in an in situ preparation and these effects may be related to changes in respiratory-sympathetic coupling.
Prospective Validation of Framingham Criteria for Congestive Heart Failure Diagnosis in a High-Altitude PopulationTo determine the validity of Framingham criteria for heart failure diagnosis in a high-altitude population.
Development and Validation of New Sepsis Criteria at High-AltitudeCurrent sepsis diagnostic criteria lose precision at high altitude due to physiological variation in vital functions. Because of that, it is necessary to elaborate new sepsis diagnostic criteria, especially designed for its use at populations living at 2000 meters above sea level or higher altitudes.
Cerebrovascular CO2 Reactivity: A Potential Tool for Prevention of High Altitude Brain EdemaIn Rotterdam in 1996 with invasive neurological monitoring systems, such as brain tissue oxygen monitoring (PbtiO2), jugular bulb oxygen catheters (SavO2j), intracranial pressure (ICP), exhaled CO2, and arterial blood gases in patients with severe cranial lesions, we designed a test to measure the CO2 reactivity. This test produced moderate hyperventilation, CO2 decreased from 35 ± 2 mm Hg to 31 ± 3 mm Hg. Since hyperventilation is a common therapeutic routine in severe head trauma, which decreases ICP, it is actually a controversial maneuver since that hyperventilation decreases CBF and oxygen delivery.
Vihangam Yoga Helps in High Altitude Chronic HypoxiaThe basic biochemical reaction for energy production in the body depends on oxygen. A minimum level of oxygen is essential at tissue level to sustain that basic metabolic reaction at the required rate. If oxygen falls below the critical level, the body system switches to an anaerobic process which cannot sustain life for long. This deficiency at tissue level is known as hypoxia. How can Vihangam yoga help in high altitude hypoxia? There are two options: either we maintain the supply or we decrease the oxygen demand: 1) Oxygen transport to supply at the required consumption; 2) Acclimatizing by increasing the hemoglobin concentration of the blood; 3) The way in which yoga can help is by reducing the demand by practicing yoga at level of life force (Prana), we can regulate our basic metabolic rate, hence we are reducing the demand.
Media and Mountain Medicine: A Commitment: Role and Impact of Media on Society and with Special Reference to Newspapers’ Role in Public AwarenessMedia is dynamic and plays an important and significant role in our society today. Media is all round us 24/7 and 365 days, in newspapers daily, weekly, or monthly; magazines, books, journals and periodicals; the television channels show news and programs on varied subjects be it education, agriculture, sports, science and technology, health and fitness, or entertainment. The radio broadcasts music, news, and public awareness programs on FM/MW/SW Radio stations. The new age of media includes the Internet and other social media: Twitter, Instagram, Facebook, and others.
Mountains—Law—Ethics“Don’t look up at the mountain, climb it.” Thus said Swami Vivekananda. Climb the mountain we can see the world, not so world can see us. When a goal matters enough to a person, that person will find a way to accomplish what first seemed impossible. Mountains therefore instigate us to make an adventurous attempt which has enormous environmental, socioeconomic and cultural value comprising vitally important resources and functions that benefit society both directly and indirectly: as regulators of climate and water resources; containing important water reserves and providing us with fuel as sanctuaries of a large diversities ecosystems, with unique and exclusive species and an extraordinary variety of landscapes, communities, languages, and cultures, as studying grounds for disciplines such as geology and biology and as ideal settings to develop environmental education activities.