Zebra Card LU-003: extended breath-holding

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	Childhood ability to hold breath or swim underwater much longer than others
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	predisposes to blue bloater type of chronic obstructive pulmonary disease
	Discussion -- not available online	[Top] [Nav]

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	Crocodiles can stay underwater for over an hour. How? Their hemoglobin molecules are uniquely adapted: as carbon dioxide and, therefore, bicarbonate ions, accumulate in the blood, bicarbonate binds to hemoglobin and actually causes the hemoglobin to release oxygen. In humans, alas, bicarbonate does not bind to hemoglobin, so human hemoglobin does not unload its oxygen as readily when carbon dioxide is accumulating. [101] Patients with panic disorder demonstrate a hypersensitivity to carbon dioxide. [104] Speculates that panic disorder is due to a false "suffocation alarm." [105]

	101.	Transplanting a unique allosteric effect from crocodile into human haemoglobin [see comments]. Komiyama NH, Miyazaki G, et al. Nature 1995 Jan 19;373(6511):244-6. Pubmed+Abstract Similars
	102.	Chemosensitivity and perception of dyspnea in patients with a history of near-fatal asthma [see comments]. Kikuchi Y, Okabe S, et al. N Engl J Med 1994 May 12;330(19):1329-34. Pubmed+Abstract Similars
	103.	Breath-holding time in normal subjects, snorers, and sleep apnea patients. Taskar V, Clayton N, et al. Chest 1995 Apr;107(4):959-62. Pubmed+Abstract Similars
	104.	Carbon dioxide hypersensitivity, hyperventilation, and panic disorder. Papp LA, Klein DF, et al. Am J Psychiatry 1993 Aug;150(8):1149-57. Pubmed+Abstract Similars
	105.	False suffocation alarms, spontaneous panics, and related conditions. An integrative hypothesis [see comments]. Klein DF. Arch Gen Psychiatry 1993 Apr;50(4):306-17. Pubmed+Abstract Similars

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