Publications by authors named "Gerard F A Jansen"

Humans have populated the Tibetan plateau much longer than the Andean Altiplano. It is thought that the difference in length of occupation of these altitudes has led to different responses to the stress of hypoxia. As such, Andean populations have higher hematocrit levels than Himalayans.

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Cerebral autoregulation is impaired in Himalayan high-altitude residents who live above 4,200 m. This study was undertaken to determine the altitude at which this impairment of autoregulation occurs. A second aim of the study was to test the hypothesis that administration of oxygen can reverse this impairment in autoregulation at high altitudes.

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Brain edema and swelling often complicate surgery for brain tumors. Its pathophysiology is unclear, as is the relationship with brain tissue oxygenation. Our hypothesis was that brain edema around tumor is cytotoxic type caused by impaired local tissue oxygenation due to increased local tissue pressure.

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Hypoxic ventilatory response is higher in successful extreme-altitude climbers than in controls. We hypothesized that these climbers have lower brainstem blood flow secondary to hypoxia which may possibly cause retention of medullary CO(2) and greater ventilatory drive. Using transcranial Doppler, basilar artery blood flow velocity (Vba) was measured at sea level in 7 extreme-altitude climbers and 10 controls in response to 10 min sequential exposures to inspired oxygen fractions (FI(O(2))) of 0.

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