[Plasma and red blood cell superoxide dismutase activity in patients with different stages of essential hypertension]. / Aktivnost superoksid dizmutaze u plazmi i eritrocitima bolesnika sa razlicitim stadijumima esencijalne hipertenzije.

It has been suggested that superoxide dismutase (SOD) plays an important role in endothelial dysfunction in essential hypertension (EH), by competing with nitric oxide for superoxide, thus influencing nitric oxide bioavailability. To answer the question of whether endothelial dysfunction is consequence of altered SOD expression we determined SOD activity in patients with different stages of EH. In this study 45 EH patients and 25 normotensive subjects were included. EH patients were divided into the three groups according to the guidelines of European Society of Hypertension. SOD activity was determined spectrophotometrically in RBC and plasma of EH patients and controls. The results obtained have shown that all groups of EH patients exhibit lower SOD activity than control normotensive subjects. Significant correlation between SOD activity and both diastolic (p<0.05, r=-0.394) and systolic blood pressure (p<0.05, r=-0.356) was found. Lowering of SOD activity in patients with different stages of EH leads to inefficient detoxification of superoxide in EH. An excess of superoxide of both cellular and extracellular origin takes part in enhanced degradation of nitric oxide and altered vasodilation, and consequent endothelial dysfunction.

[Intramural hematoma in acute aortic syndrome]. / Intramuralni hematom u akutnom aortnom sindromu.

Intramural haematoma is the precursor or the variant of a classical aortic dissection where hemorrhage occurs within the aortic wall (aortic media) and in absence of initial intimal tear. This entity looks like a classical aortic dissection, but it differs from it by its pathological characteristics. Although the intimal tear is absent, the prognosis of patients with intramural haematoma is similar to that of patients with classical aortic dissection; it is therefore very important for these patients to be early diagnosed. With a development of modern non-invasive diagnostical techniques the intramural haematoma is more often diagnosed and actually amounts at 10 to 30% of all acute aortic syndrome cases. Clinical characteristics and death rate of patients with intramural hematoma are similar to those of patients with classical aortic dissection, especially when it is obvious that there is a considerable risk for intramural haematoma to complicate into aortic ulcer, aortic aneurysm or rupture. Since intramural haematoma comprehensive diagnostic technique does not exist, safe therapy has not been yet established. Future randomized studies and serial observation of patients with intramural hemorrhage are indispensable not only to clarify these patients' survival predictors but also to define a model of optimal therapy.