Beclin-1 increases with obstructive sleep apnea severity

Obstructive sleep apnea is a common chronic disorder that leads to chronic intermittent hypoxia described as an important factor contributing to the pathogenesis of OSA-related comorbidities. Besides, recent data suggest that intermittent hypoxia can induce adaptative cardiovascular pathways inducing a relative resistance to ischemic insults. Adaptative pathways induced by hypoxia could implicate autophagic processes and Beclin-1, one of the first mammalian autophagy effectors. Thus, activation of autophagy could protect against cardiovascular events in patients with OSA and could be considered as biomarker of a better prognosis.     

Heme oxygenase-1 and chronic hypoxia

A myriad of changes are necessary to adapt to chronic hypoxemia. Key among these changes increases in arterial oxygen carrying capacity, ventilation and sympathetic activity. This requires the induction of several gene products many of which are regulated by the activity of HIF-1α, including HO-1. Induction of HO-1 during chronic hypoxia is necessary for the continued breakdown of heme for the enhanced production of hemoglobin and the increased respiratory and sympathetic responses. Several human HO-1 polymorphisms have been identified that can affect the expression or activity of HO-1. Associations between these polymorphisms and the prevalence of hypertension have recently been assessed in specific populations. There are major gaps in our understanding of the mechanisms of how HO-1 mediates changes in the activity of the hypoxia-sensitive chemosensors and whether HO-1 polymorphisms are an important factor in the integrated response to chronic hypoxia. Understanding how HO-1 mediates cardiorespiratory responses could provide important insights into clinical syndromes such as obstructive sleep apnea.     

Role of antiplatelet therapy in cardiovascular disease I: acute coronary syndromes

The acute coronary syndromes (ACS), consisting of ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and unstable angina, remain a leading cause of death in the United States. Through the process of atherothrombosis, underlying atherosclerosis can progress to an acute ischemic coronary event. This disease mechanism is also common to ischemic

stroke and peripheral arterial disease. As ACS is a heterogeneous disease, accurate patient diagnosis and risk categorization is essential. Treatment approaches for both STEMI and NSTEMI ACS consist of a combination of surgical intervention and pharmacotherapy, with antiplatelet agents such as clopidogrel, aspirin and glycoprotein IIb/IIIa receptor antagonists playing an essential role.