The science of vascular biology has emerged and expanded rapidly over the past 25
years. Research in this area has increased understanding of a wide range of clinical
conditions. This book provides a broad overview of the Weld for both specialist
and newcomer to the Weld, and concise resource for the non-specialist. The
multidisciplinary team of contributors covers topics ranging from normal and
pathological aspects of endothelial cell function to the role of the vasculature in
pregnancy, hypertension and atherosclerosis....
The last quarter of a century has seen dramatic
developments in the management of cardiovascular
diseases. Besides the pioneering developments in
the medical management of cardiovascular disorders
the field of interventional cardiology has also emerged
as a major discipline with a huge impact on the
clinical management of acute coronary syndrome,
chronic coronary artery disease, congestive heart
failure, and peripheral vascular and valvular diseases.
Presyncopal symptoms vary in duration and may increase in severity until loss of consciousness occurs, or they may resolve prior to loss of consciousness if the cerebral ischemia is corrected. The differentiation of syncope from seizure is an important, sometimes difficult, diagnostic problem.Syncope may be benign when it occurs as a result of normal cardiovascular reflex effects on heart rate and vascular tone, or serious when due to a life-threatening cardiac arrhythmia.
Disorders of Vascular Tone or Blood Volume
Disorders of vascular tone or blood volume that can cause syncope include the reflex syncopes and a number of conditions resulting in orthostatic intolerance. The reflex syncopes—including neurocardiogenic syncope, situational syncope, and carotid sinus hypersensitivity—share common autonomic nervous system pathophysiologic mechanisms: a cardioinhibitory component (e.g., bradycardia due to increased vagal activity), a vasodepressor component (e.g., inappropriate vasodilatation due to sympathetic withdrawal), or both.
Nitric oxide (NO) is a potent intra- and intercellular mes-senger involved in the control of vascular tone, neuronal
signallingandhost response to infection. Inmammals,NOis
synthesized by oxidation ofL-arginine catalysed by heme-proteins called NO-synthases with intermediate formation
-hydroxy-L-arginine (NOHA). NOHA and some
hydroxyguanidines have been shown to be able to deliver
nitrogen oxides including NO in the presence of various
Normalization of tumor blood vessels due to inhibition of VEGF signaling.
A. Blood vessels in normal tissues exhibit a regular hierarchical branching pattern that delivers blood to tissues in a spatially and temporally efficient manner to meet the metabolic needs of the tissue (top). At the microscopic level, tight junctions are maintained between endothelial cells (EC), which are adherent to a thick and evenly distributed basement membrane (BM). Pericytes form a surrounding layer that provides trophic signals to the EC and helps maintain proper vessel tone.