Oral contraceptive use and acute mountain sickness in South Pole workers.

Introduction: Progesterone has a number of properties that could influence the development of acute mountain sickness (AMS), including anti-inflammation, respiratory smooth muscle relaxation, ventilatory stimulation, and antidiuretic characteristics. Oral contraceptive (OC) use decreases levels of circulating progesterone by preventing ovulation. We hypothesized rates of AMS development would be significantly higher in OC users as compared to Non-OC users in a population traveling rapidly to the South Pole.

Physiological variables associated with the development of acute mountain sickness at the South Pole.

Unlabelled: Exposure to altitudes >2500 m can result in acute mountain sickness (AMS), a mild and usually self-limiting condition. Research has attempted to identify factors associated with developing AMS without controlling important factors related to the ascent or collecting a comprehensive set of variables.

Objectives: The Antarctic Study of Altitude Physiology (ASAP) investigated variables associated with the development of AMS in adults experiencing rapid passive transport to altitude by airplane.

Are we aware of microbial hotspots in our household?

Household microorganisms are found in unexpected places. Therefore, the authors conducted a study to investigate the microbial hotspots and reveal the misconceptions regarding the most contaminated objects in the household. In the authors' study, 26 daily use objects in 22 households were sampled to determine the levels of heterotrophic plate count (HPC), coliforms, E.

Incidence and Symptoms of High Altitude Illness in South Pole Workers: Antarctic Study of Altitude Physiology (ASAP).

Introduction: Each year, the US Antarctic Program rapidly transports scientists and support personnel from sea level (SL) to the South Pole (SP, 2835 m) providing a unique natural laboratory to quantify the incidence of acute mountain sickness (AMS), patterns of altitude related symptoms and the field effectiveness of acetazolamide in a highly controlled setting. We hypothesized that the combination of rapid ascent (3 hr), accentuated hypobarism (relative to altitude), cold, and immediate exertion would increase altitude illness risk.

Methods: Medically screened adults (N = 246, age = 37 ± 11 yr, 30% female, BMI = 26 ± 4 kg/m(2)) were recruited.

Effects of acute changes in pulmonary wedge pressure on periodic breathing at rest in heart failure patients.

Background: Patients with heart failure (HF) display a number of breathing abnormalities including periodic breathing (PB) at rest. Although the mechanism(s) contributing to PB remain unclear, we examined whether changes in pulmonary wedge pressure (PWP) and pulmonary vascular resistance (PVR) alter PB in patients with established HF.

Methods: We studied 12 male patients with HF (age, 50 +/- 11 years; ejection fraction, 18.

Pathophysiological characteristics of heart rate recovery in heart failure.

Purpose: Heart failure (HF) is associated with blunted HR recovery after exercise. The determinants of altered HR recovery in HF are unknown. The aim of this study was to investigate clinical correlates of HR recovery in HF patients.