Physical inactivity and platelet function in humans and brown bears: A comparative study.

Physical inactivity increases the risk of thromboembolism. However, good standardized human models on inactivity are in short supply and experimental models are few. Our objective was to investigate how standardized bed rest affects platelet aggregation in humans and to investigate if aggregation is altered in a translational model system - the hibernating brown bear (Ursus arctos).

Biochemical Foundations of Health and Energy Conservation in Hibernating Free-ranging Subadult Brown Bear Ursus arctos.

Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy.

Downregulation of platelet activation markers during long-term immobilization.

Immobilization and sedentary lifestyle are risk factors for venous thromboembolism and cardiovascular disease, yet little is known about platelet function during long-term physical inactivity. Our aim was to investigate platelet activation markers and their coupling to standardized immobilization: platelet-derived growth factor (PDGF-BB) and P-selectin. We studied 15 healthy females participating in the Women International Space simulation for Exploration study.

Brown bears (Ursus arctos) seem resistant to atherosclerosis despite highly elevated plasma lipids during hibernation and active state.

Hibernation is an extreme physiological challenge for the brown bear (Ursus arctos) in which metabolism is based mainly on lipids. The study objective was to compare plasma lipids in hibernating and active free-ranging brown bears and relate them to arterial histopathology. Blood was drawn from seven immobilized free-ranging brown bears (three females, 2-3 years old) during hibernation in February and from the same bears while active in June and analyzed by enzymatic and automated hematology methods within 48 hours of sampling.

Effect of prolonged standardized bed rest on cystatin C and other markers of cardiovascular risk.

Background: Sedentary lifestyle is associated with coronary artery disease but even shorter periods of physical inactivity may increase cardiovascular risk. Cystatin C is independently associated with cardiovascular disease and our objective was to investigate the relation between this novel biomarker and standardized bed rest. Research of immobilization physiology in humans is challenging because good biological models are in short supply.

Angiographic morphology impacts outcomes in STEMI patients with LAD occlusion.

Objectives And Background: Acute proximal occlusion of the left anterior descendent coronary artery (LAD) is a critical medical condition often leading to heart failure and death. Our objective was to investigate how additional angiographic findings might influence prognosis.

Methods: In a single center setting by using consecutive data from the Swedish angiography and angioplasty registry (SCAAR), we identified all patients with acute myocardial infarction (AMI) related to the proximal LAD referred for primary coronary angioplasty.