Vascular Remodeling in Health and Disease

The term vascular remodeling is commonly used to define the structural changes in blood vessel geometry that occur in response to long-term physiologic alterations in blood flow or in response to vessel wall injury brought about by trauma or underlying cardiovascular diseases.1, 2, 3, 4 The process of remodeling, which begins as an adaptive response to long-term hemodynamic alterations such as elevated shear stress or increased intravascular pressure, may eventually become maladaptive, leading to impaired vascular function. The vascular endothelium, owing to its location lining the lumen of blood vessels, plays a pivotal role in regulation of all aspects of vascular function and homeostasis.5 Thus, not surprisingly, endothelial dysfunction has been recognized as the harbinger of all major cardiovascular diseases such as hypertension, atherosclerosis, and diabetes.6, 7, 8 The endothelium elaborates a variety of substances that influence vascular tone and protect the vessel wall against inflammatory cell adhesion, thrombus formation, and vascular cell proliferation.8, 9, 10 Among the primary biologic mediators emanating from the endothelium is nitric oxide (NO) and the arachidonic acid metabolite prostacyclin [prostaglandin I2 (PGI2)], which exert powerful vasodilatory, antiadhesive, and antiproliferative effects in the vessel wall

Amino acid clearance in cirrhosis : a predictor of postoperative morbidity and mortality

The central plasma clearance rate of amino acids (CPCR-AA), the ratio of peripheral amino acid entry rate into blood plasma to arterial amino acid concentration, was measured preoperatively in 149 noninfected cirrhotic patients. In 50 survivors of shunting or general surgical procedures, the mean (+/- SEM) CPCR-AA was 201 +/- 17 mL/m2/min; in 39 subsequent deaths, the mean ratio was 87 +/- 14 mL/m2/min. Comparing Child's classification with CPCR-AA reveals the following values: class A (mortality, two of ten patients) survivors, 152 +/- 23 mL/m2/min; class A deaths, 96 +/- 54 mL/m2/min; class C (mortality, 13 of 19 patients) survivors, 214 +/- 47 mL/m2/min; class C deaths, 101 +/- 13 mL/m2/min. The preoperative CPCR-AA of 46 patients receiving liver transplants was 91 +/- 9 mL/m2/min; 69% of these patients survived. Preoperative CPCR-AA values correlated significantly with rates of hepatic protein synthesis in incubated liver slices obtained by biopsy at operation in 22 patients. Thus, CPCR-AA determination is a true liver function test, valuable in predicting surgical mortality and selecting transplantation or other operations for cirrhotic patients