Effect of Ultramarathon Trail Running at Sea Level and Altitude on Alveolar-Capillary Function and Lung Diffusion.

Introduction: Endurance exercise at altitude can increase cardiac output and pulmonary vascular pressure to levels that may exceed the stress tolerability of the alveolar-capillary unit. This study examined the effect of ultramarathon trail racing at different altitudes (ranging from <1000 m to between 1500 and 2700 m) on alveolar-capillary recruitment and lung diffusion.

Methods: Cardiac and lung function were examined before and after an ultramarathon in 67 runners (age: 41 ± 9 yr, body mass index: 23 ± 2 kg·m -2 , 10 females), and following 12-24 h of recovery in a subset ( n = 27).

Metabolic insights at the finish line: deciphering physiological changes in ultramarathon runners through breath VOC analysis.

Exhaustive exercise can induce unique physiological responses in the lungs and other parts of the human body. The volatile organic compounds (VOCs) in exhaled breath are ideal for studying the effects of exhaustive exercise on the lungs due to the proximity of the breath matrix to the respiratory tract. As breath VOCs can originate from the bloodstream, changes in abundance should also indicate broader physiological effects of exhaustive exercise on the body.

Alveolar to arterial gas exchange during constant-load exercise in healthy active men and women.

Inadequate hyperventilation and inefficient alveolar to arterial gas exchange are gas exchange challenges that can limit capacity and cause exercise-induced arterial hypoxaemia (EIAH). This work evaluated if the prevalence of gas exchange inefficiencies, defined as AaDO>25 mmHg, PaCO>38 mmHg, and/or ΔPaO>-10 mmHg at any point during constant-load exercise in healthy, active, but not highly trained, individuals suggested an innate sex difference that would make females more susceptible to EIAH. Sixty-four healthy, active males and females completed 18-min of cycling exercise (moderate and vigorous intensity, 9 min/stage).

Hypersensitivity reactions to high osmolality Total Parenteral Nutrition: a case report.

Background: The full range of allergic reactions to Total Parenteral Nutrition (TPN) remains unknown. Additionally, beyond individual allergens, there may be other factors contributing to TPN hypersensitivity reactions.

Case Presentation: We present a case of a patient with negative skin testing to common TPN allergens who had recurrent urticarial reactions to TPN.

A 'crying wolf' game of interspecific kleptoparasitic mutualism.

We model a potentially mutualistic interaction between a species making antipredator alarm calls and a species which eavesdrops on those calls. Callers may or may not make deceptive alarm calls in order to kleptoparasitize food from eavesdroppers, which in turn may either heed or ignore all alarm calls. The two most likely outcomes in our model are either maximally deceptive callers and maximally trusting eavesdroppers, or persistently cycling strategy frequencies.

Substernal epicardial echocardiography: review of a new technique.

Background: Patients after cardiac operation pose a challenge to the treating physician-these patients may become critically ill and are among the most difficult to image using transthoracic echocardiography. Several factors contribute to this, including difficulties in positioning the patient, inability of the patient to cooperate with instructions, surgical dressings, and hyperinflated lungs. Transesophageal echocardiography may be performed when transthoracic echocardiography is not diagnostic; however, transesophageal echocardiography is semi-invasive and does not lend itself to prolonged or repeated monitoring.