Relation between serum uric acid and carotid intima-media thickness in healthy postmenopausal women

OBJECTIVE: Serum uric acid (SUA) is associated with cardiovascular disease (CVD). However it is still disputed whether the relationship is mediated by other risk factors such as obesity, dyslipidaemia, hypertension and insulin resistance. We explored the association of the uric acid level with carotid intima-media thickness (IMT), a well known marker of CVD, in postmenopausal healthy women. METHODS: We consecutively enrolled postmenopausal women undergoing a screening for health evaluation. After an accurate clinical examination, and a biochemical evaluation, the enrolled subjects underwent B mode ultrasonography to assess common carotid intima media thickness. RESULTS: Among 234 women aged 45-70 years, the uric acid level is associated with carotid IMT independently of other prognostic factors (p=0.03). In particular, women in the highest tertiles of uric acid level have a greater IMT than women in the lowest tertile (p=0.007). CONCLUSIONS: Independently of other cardiovascular risk factors, SUA levels are associated with carotid IMT even in subjects without the metabolic syndrome. This confirms and expands the role of uric acid in the determinism of CVD. Prospective trials would be useful to evaluate interventions aimed at lowering the uric acid level

Detection of xanthine oxidase in human atherosclerotic specimens and arterialized vein grafts

Xanthine oxidase is an essential enzyme in the formation of uric acid and has been previously identified by immunohistochemistry in liver, intestine and capillary endothelial cells. The purpose of this study was to investigate the presence of xanthine oxidase in human atherosclerotic plaques. Atherosclerotic plaques from carotid endarterectomy pathology specimens were snap frozen in liquid nitrogen, placed in an OCT block, and cut to a thickness of 6 microns with a cryotome. Slides were stored at -120° C until ready for staining Immunohistochemical staining, using a polyclonal rabbit anti-xanthine oxidase antibody (Fitzgerald, Concord MA), was performed on 17 specimens which included 14 carotid endarterectomy plaques, 2 transplant donors and 1 arterialized saphenous vein graft. The staining for xanthine oxidase was found to be positive in carotid artery from transplant donors, carotid artery plaques and the arterialized vein graft. The carotid artery of donors was found to have positive staining in the intima that was less than the staining of smooth muscle cells in the media. Occasional cells the adventitia also stained positive. The carotid plaques were found to be irregularly stained, with endothelial cells and smooth muscle cells staining positive in the intima. The thickened intimal and medial areas of the plaques had cholesterol clefts whose periphery stained more intensively than the rest of the plaque. Additional staining using an antibody against uric acid crystals was, likewise, positive in these areas. In the arterialized vein graft, endothelial cells and smooth muscle cells, likewise, stained positive for xanthine oxidase in the thickened intima. The layers beyond the elastic lamina were negative. These results suggest that xanthine oxidase is expressed in smooth muscle cells and endothelial cells. The identification of xanthine oxidase in the plaque of disease arteries and arterialized vein graft suggest a possible relationship between the presence of xanthine oxidase and the development of atherosclerosis and/or intimai hyperplasia

The effect of "Hes-pz" solution in a model of spinal cord ischemia

Paraplegia following thoracoabdominal aneurysm repair has been attributed to ischemia and reperfusion injury. The low molecular weight plasma expander "Hes-pz" has been shown to decrease reperfusion injury in cardiac and skeletal muscle The purpose of this study is to determine if "Hes-pz" has a protective effect on the spinal cord following aortic cross clamping in the rabbit model Eighteen New Zealand white rabbits underwent operative replacement of a infrarenal aortic occlusive device tunneled into a subcutaneous position Animals were allowed to recover for 48hrs Two groups of 9 animals each underwent infrarenal aortic occlusion for 21 min by tightening the snare in the awake animal. Group 1 (control) received 6% Hespan and group 2 (treated) received 6% "Hes-pz" Both groups received an estimated 4% blood volume The solutions were administered immediately following unclamping Animals were observed for 5 days and graded (Tarlov Scale) by an independent observer. Animals were then euthanized and spinal coids harvested for histological examination with hematosylin-eosin and triphenyl tetrazolium chloride staining Complete paraplegia was seen in (78% (7/9) of group 1 rabbits vs 11% (1/9) group 2 rabbits (p< 0.05). Histological findings were consistent with less cell injury in group 2 Our results show that treatment with "Hes-pz" may reduce paraplegia following aortic clamping and reperfusion