Seitoku Mizuno

Platelet-activating factor acetylhydrolase in plasma lipoproteins from patients with ischemic stroke.

Background and Purpose Platelet-activating factor is a potent bioactive phospholipid and may play an important role in occlusive vascular diseases. To assess the inactivation of this autacoid in plasma, we measured platelet-activating factor acetylhydrolase activity in plasma low density and high density lipoproteins from patients with ischemic stroke. Methods Low density and high density lipoproteins were separated by ultracentrifugation from plasma of 33 patients with cerebral thrombosis and 31 age-matched healthy control subjects, and plateletactivating factor acetylhydrolase activity in each fraction was assayed. Results The average values of platelet-activating factor acetylhydrolase activity in low density lipoprotein from patients and control subjects were 41±18 and 29±17 nmol/ml per minute, respectively, and the difference was statistically significant (p<0.01, U test). There was no difference in activity in high density lipoprotein between the two groups (16±11 versus 14±9 nmol/ml per minute, respectively). Conclusions The increased plasma platelet-activating factor acetylhydrolase activity in stroke patients is primarily attributable to the increased binding to low density lipoprotein, and this increase may be an adaptation to the augmented generation of platelet-activating factor in ischemic stroke.

Fibrinogen/Albumin Ratio: A Useful Indicator of Hemorheological Abnormalities in Observation of Cerebrovascular Disorders

Although the importance of local microcirculatory disturbances in thrombotic disorders has been generally recognized [1, 3, 5], clinical observations from the viewpoint of hemorheology have not been made intensively because of difficulties in the detection of changes occurring in the microcirculation. A high ratio of fibrinogen to albumin accelerates the erythrocyte aggregation in capillaries which is responsible for the occurrence of thrombotic diseases [1]. This study aims to establish the usefulness of the ratio of fibrinogen to albumin for observations of cerebrovascular disorders.