A three-year-old male child presented after sustaining a fall from a second story window onto a fence below. The long axis of the child’s vertebral column was oriented perpendicular to the length of the fence, causing the majority of the forces to be directed to the spinous processes of T3-4. Initial neurological examination demonstrated complete loss of motor and sensory function below the T4 ...

Dear Editor, Mycoplasma pneumoniae belongs to the class Mollicutes and is a small bacterium without a cell wall that is a common cause of community-acquired pneumonia in adults and children. Due to its unique physical structure, M. pneumoniae is resistant to cell wall-targeting agents, such as beta-lactam antibiotics. Therefore, the antibiotics of choice for the treatment of suspected M. pneumo...

The factor VII–activating protease (FSAP), a newly discovered serine-protease present in human plasma, has 2 main functions in hemostasis: it is a potent activator of prourokinase1 and accelerates coagulation by activating factor VII, independently of tissue factor.2 The FSAP Marburg I polymorphism (1601G A) was recently evaluated as a candidate risk factor for venous thromboembolism (VTE), sin...

Prorenin, the precursor of renin, exists in circulating blood at concentrations that are 5 to 10 higher than those of renin. For many years, prorenin was considered to be an inactive form of renin with no physiological role. Then, in the mid-80s of the last century, Luetscher et al reported that the levels of circulating prorenin (but not renin) are increased in diabetic subjects.1 Subsequent s...

One of the most difficult concepts in heart development is to convert a looped tube with the presumptive right and left chambers in series to a 4-chambered heart with blood flowing from right atrium to right ventricle and left atrium to left ventricle. Try to explain how it happens to a room full of typical first-year medical students (“just tell me what I need to know”) if you are into self-la...

Blood vessels are highly active structures whose morphology rapidly adapts to maintain vascular function under altered systemic and local conditions. In some instances, this normally beneficial adaptation may be detrimental to overall function. Structural adaptations with important physiological and pathophysiological impact include angiogenesis, the remodeling of resistance arteries, and steno...

The vascular endothelium synthesizes and releases a range of vasodilators and vasoconstrictors that have key roles in the local regulation of vascular tone. Among those, endothelin (ET) was identified in 1988 by Yanagisawa et al,1 as one of the most potent vasoconstrictors known, and so far, the landmark discovery of ET has led to 22 000 publications. These have revealed that ET exerts its acti...

To the Editor: We read with interest both the recent paper by Dunzendorfer et al1 and the accompanying commentary.2 We wish to clarify some key points. Dunzendorfer et al report that under antiatherogenic conditions of laminar flow, human coronary artery endothelial cells (ECs) express low levels of Toll-like receptor 2 (TLR2) mRNA and protein. Dunzendorfer et al also reported that TLR2 mRNA an...

In a remarkable article published in this issue of Circulation Research, Ryoo et al1 propose endothelial arginase II as a novel target for the treatment of atherosclerosis. Actually, they already had done so 2 years ago, based on work mainly on cultured human aortic endothelial cells,2 which indeed appeared to provide an unexpected way to explain endothelial dysfunction in terms of NO productio...

Experimental and clinic studies show that chronic hypertension leads to myocardial pathology and systolic and diastolic dysfunctions that frequently progress to heart failure.1 Elevated afterload causes cardiomyocyte hypertrophy, which alters myocardial energy metabolism by increasing glucose metabolism and impairing mitochondrial oxidative capacity, increasing the production of reactive oxygen...