[Determination of the activity of Willebrand's factor by laser analyzer of platelet aggregation]. / Opredelenie aktivnosti faktora Villebranda pri pomoshchi lazernogo analizatora agregatsii trombotsitov.

A modification of von Willebrand' factor/ristocetin cofactor activity test is proposed. Agglutination of formalin-treated platelets is monitored in the aggregation analyzer from changes in the light transmission in the specimen. The test is sensitive and reproducible. It is intended for clinical laboratories to be used in patients with hematological diseases and the endotheliopathy syndrome of different etiology.

[The effect of ximedon on cholesterol metabolism and experimental atherosclerosis in rabbits]. / Vliianie ksimedona na metabolizm kholesterina i éksperimental'nyi ateroskleroz u krolikov.

The effects produced by the two pyrimidine derivatives pyridinol carbamate (parmidine) and xymedon on cholesterol metabolism and experimental atherosclerosis were comparatively studied in rabbits. The rabbits were fed either a chow containing cholesterol (200 mg/kg body weight) or the same diet also containing xymedon (30 mg/kg body weight) or pyridinol carbamate (30 mg/kg body weight). Total plasma cholesterol showed 5.5- and 4.7-fold increases in the rabbits receiving only cholesterol or cholesterol + pyridinol carbamate, respectively, as compared with that in the animals on a standard laboratory chow. In the rabbits given cholesterol+xymedon, cholesterol levels were 24% less than that in the animals taking cholesterol alone. In these animals, the aortic atherosclerotic damage index (ADI) was equal to 24.1%, which was 1.8-fold less than that in the cholesterol-fed rabbits. In the rabbits given cholesterol+pyridinol carbamate, ADI was decreased by 1.7 times, but it did not differ from that in the hypocholesterolemic rabbits. At the same time xymidone and pyridinol carbamate reduced the hepatic levels of total and esterified cholesterol. To elucidate the mechanism of action of xymedon, it was studied for effects on cholesterol metabolism in cultured rabbit hepatocytes and murine macrophage J774. Xymedon did not alter the esterification and other parameters of cholesterol metabolism in the cultured hepatocytes. It is suggested that the hypocholesterolemic effect was realized at the level of intestinal rather than hepatic cholesterol metabolic changes. The investigations made on the murine macrophage J744 showed that xymedone reduced cholesterol esterification in macrophages, evidently by inhibiting the activity of the enzyme acyl-CoA: cholesterol acyltransferase. The anti-atherosclerotic effect of xymedon seems to result from reductions in plasma cholesterol levels and cholesterol esterification in blood vascular cells.

[The comparative characteristics of the antiatherogenic effect of xymedon and parmidine]. / Sravnitel'naia kharakteristika antiaterogennogo éffekta ksimedona i parmidina.

We've studied xymedon (30 mg/kg, 12 m) and parmidin (pyridinolcarbamate 30 mg/kg, 12 m.) effects on the development of experimental cholesterol atherosclerosis on rabbits. It was demonstrated that after the use of xymedon aorta damage reduces twice. Xymedon also prevents accumulation of cholesterol and fatty degeneration of the liver. Antiatherogenic effect of xymedon resulted comparable with the effect of parmidin. As it was demonstrated in the present investigation and in the previous ones in contrast to parmidin, xymedon normalizes the lipoproteins balance owing to increase of HDL cholesterol. It also has regenerative activity on endotheliocytes and immunomodulator properties. That can be of great importance for the anti-atherosclerotic effects of the medicine.

[Effect of cimetidine on experimental atherogenesis in rabbits]. / Vliianie tsimetidina na éksperimental'nyi aterogenez u krolikov.

It was shown that cimetidine (10 mg/kg, 12 weeks) reduces the frequency and the degree of affection of rabbit's aortas during experimental cholesterol atherosclerosis. The protective effect of cimetidine on the liver where the contents of lipids, especially cholesterol esters reduced considerably, was noted. The nature of the fatty dystrophy changes from the large-drop to the small-drop one which should be considered as a favourable phenomenon. The anti-atherogenic and hepatoprotective effects of cimetidine can be explained by slowing-down of lipoperoxidation processes which is proved in respect of blood and aorta walls.