American journal of respiratory and critical care medicine
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Medical problems occur at high altitude because of the low inspired Po(2), which is caused by the reduced barometric pressure. The classical physiological responses to high altitude include hyperventilation, polycythemia, hypoxic pulmonary vasoconstriction-increased intracellular oxidative enzymes, and increased capillary density in muscle. However, with the discovery of hypoxia-inducible factors (HIFs), it is apparent that there is a multitude of responses to cellular hypoxia. ⋯ An alternative strategy is to increase the barometric pressure as in aircraft cabins. A hybrid approach combining both strategies shows promise but has never been used. Mines that are being developed at increasingly high altitudes pose great medical problems.
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Am. J. Respir. Crit. Care Med. · Dec 2012
ReviewImproving post-intensive care unit neuropsychiatric outcomes: understanding cognitive effects of physical activity.
Critical illness and its treatment often result in long-term neuropsychiatric morbidities. Consequently, there is a need to focus on means to prevent or ameliorate these morbidities. Animal models provide important data regarding the neurobiological effects of physical activity, including angiogenesis, neurogenesis, and release of neurotrophic factors that enhance plasticity. ⋯ Barriers exist regarding implementing ICU rehabilitation in routine care, including use of sedatives and lack of awareness of post-ICU cognitive impairments. Further research is necessary to determine whether prior animal and human research, in conjunction with preliminary results from existing ICU studies, can translate into improvements for neuropsychiatric outcomes in critically ill patients. Studies are needed to evaluate biological mechanisms, risk factors, the role of pre-ICU functional level, and the timing, duration, and type of physical activity for optimal patient outcomes.
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Am. J. Respir. Crit. Care Med. · Dec 2012
ReviewThe next generation of complex lung genetic studies.
Common genetic risk variants identified by genome-wide association studies have explained a small portion of disease heritability in complex diseases. It is becoming apparent that each gene/locus is heterogeneous and that multiple rare independent risk alleles across the population contribute to disease risk. ⋯ Although data analysis approaches are still evolving, a number of published studies have successfully identified rare variants associated with complex disease. Despite many challenges that lie ahead in applying these technologies to lung disease, rare variants are likely to be a critical piece of the puzzle that needs to be solved to understand the genetic basis of complex lung disease and to use this information to develop better therapies.
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Am. J. Respir. Crit. Care Med. · Dec 2012
Letter Review Case ReportsA case of cranial air embolism after transthoracic lung biopsy.