History of space medicine: the formative years at NASA.

Almost nothing was known about the effects of spaceflight on human physiology when, in May of 1961, President John F. Kennedy committed the United States to land a man on the Moon and return him safely to Earth within the decade. There were more questions than answers regarding the effects of acceleration, vibration, cabin pressure, CO2 concentration, and microgravity.

Evidence for increased beta-adrenoreceptor responsiveness induced by 14 days of simulated microgravity in humans.

We studied hemodynamic responses to alpha- and beta-receptor agonists in eight healthy men before and after 14 days of 6 degrees head-down tilt (HDT) to test the hypothesis that increased adrenoreceptor responsiveness is induced by prolonged exposure to simulated microgravity. Steady-state infusions of isoproterenol (Iso) at rates of 0.005, 0.

Application of USAF G-suit technology for clinical orthostatic hypotension: a case study.

Introduction: The purpose of this study was to determine the effectiveness of a USAF anti-gravity suit (G-suit) on the stability of a patient with chronic orthostatic hypotension.

Methods: A 37-yr-old female with a history of insulin-dependent diabetes mellitus (IDDM) and symptomatic orthostasis was evaluated and the results were compared with those of non-diabetic controls, matched for age, height, and weight. Cardiac vagal tone was assessed by determination of standard deviation of 100 R-R intervals (R-R SD).