[Effect of x-ray contrast agents on the thromboresistant properties of vascular walls].

It is established that the x-ray contrast agents urografin, omnipak, and ultravist produce a dose-dependent decrease in the thromboresistant properties of vascular walls in experimental rats. This effect is determined by the individual properties of substances rater than by their belonging to a certain class of ionic or nonionic compounds. Preliminary administration of n3-polyunsaturated fatty acids from fish oil offers a significant protection against the negative action of x-ray contrast agents and retains the antiaggregant activity of the vessel wall intima.

[Effects of ionic and non-ionic roentgen-contrast media upon ex vivo hemostasis in rabbits].

The influence of ionic and non-ionic contrast media on the ex vivo hemostasis in rabbits was studied for ionic urografin (76 %), non-ionic ultravist-300, and non-ionic omnipaque-300 intravenously injected in medium and high doses (1.5 ml/kg and 3.0 ml/kg, respectively). Ionic urografin (1.5 ml/kg) almost did not influence the level of hemostasis ex vivo. Non-ionic contrast media (ultravist and omnipaque) in the medium diagnostic dose (1.5 ml/kg) activated the hemostasis, the effect being much more pronounced in the case of omnipaque. Dose-dependent action was observed for both ionic and non-ionic contrast media.

[Radiocontrast properties of the emulsion of the perfluoroorganic compound lipobrom]. / Rentgenokontrastnye svoistva émul'sii perftotorganicheskogo soedineniia lipobroma.

X-ray contrast properties of the new perfluoroorganic emulsion lipobrom were studied in comparison to those of a traditional clinical Roentgen diagnostic agents omnnipaque and ultravist and the well-known blood substitute perftoran. The x-ray patterns were evaluated by a computer morphodensitometry technique.

[The complement-activating action of modern x-ray contrast agents]. / Komplementaktiviruiushchee deistvie sovremennykh rentgenokontrastnykh sredstv.

The study conducted proved that triombrast (dose dependently) > hexabrics > Ultravist > or = melitrast = omnipac in a concentration interval of 0.03-30.0 mg iodine/ml in vitro and in a dose interval of 0.5-2.0 g iodine/kg in vivo activate the complement system (CS) according to the alternative way in the blood of "sensitive" rats. The degree of CS activation by radiopaque agents (ROA) is significantly determined mathematically by their viscosity and relation of the number of iodine atoms to the number of ions or dissolved particles, and by their hydrophilic (for nonion CS) and osmotic (for ion monomeric CS) properties.

[The pharmacokinetics of lincomycin when used as a component of a drug combination with ultrahighly dispersed hydroxyapatite]. / Farmakokinetika linkomitsina pri ispol'zovanii v kachestve komponenta lekarstvennoi kompozitsii s gidroksiapatitom ul'travysokoi dispersnosti.

A drug composition LINCOGAP is assessed, consisting of lincomycin hydrochloride (33%), ultrahighly dispersed hydroxyapatite (HA) (33%), gelatin (7%), and water (27%). Distribution of tritium-labeled lincomycin in organs and tissues of experimental animals was studied by the radiometric method after implantation of the composition into a standard rat mandibular defect. Lincomycin concentration surpassing by orders of magnitude the minimal inhibitory concentration for the main lincomycin-sensitive microorganisms persisted at the site of implantation of the composition for at least 7 days, while the concentration in internal organs and tissues was the minimum. Microbiological findings indicate active diffusion of lincomycin from the site of injection into the adjacent bone. Thus, LINCOGAP exerts an antibacterial effect in the pathological focus while its general toxic effect is low and, therefore, side effects are minimized. Combination of the antibiotic with ultrahighly dispersed HA helps regulate the process of bone repair, stimulating the proliferative and functional activity of osteoblasts. Hence, combined drug LINCOGAP is a promising agent for the treatment of inflammatory destructive diseases of osseous tissue.

[A dynamic study of the intensity of mitogenesis in an osteoblast culture in the presence of ultrasonically dispersed hydroxyapatite]. / Dinamicheskoe issledovanie intensivnosti mitogeneza kul'tury osteoblastov v prisutstvii gidroksiapatita ul'trazvukovoi dispersnosti.

Ceramic hydroxyapatite is frequently used in clinical practice nowadays; it is applied in surgical interventions on facial skull bones. This biological material is used as bone substitute and bone connector, but many authors claim that it is devoid of osteoinductor properties. Research is in progress on the effects of a "cold", that is, biochemically active form of ceramic hydroxyapatite on proliferative activity of a number of cell populations. No mitogenesis stimulation was observed during incubation of hydroxyapatite with osteoblast culture; on the contrary, a reduction of proliferative processes intensity was observed. Remembering that hydroxyapatite is a surfactant we repeated this experiment under similar conditions but used a hydroxyapatite molbfication with specific activity increased by two orders in comparison with its close analogs. Mitogenesis intensity was assessed by radiometric method from 3H-thymidine incorporation. The data indicated stimulation of proliferative processes in osteoblast culture.

[The effect of x-ray and NMR contrast agents on lipid peroxidation in the normal and pathological kidneys of rats]. / Vliianie rentgeno- i IaMR-kontrastnykh sredstv na perekisnoe okislenie lipidov v pochkakh krys v norme i patologii.

It has been studied in vivo and vitro effects of and NMR contrast media on renal lipid peroxidation in intact rats and animals with experimental pathologies; glycerine nephritis and CCL4 intoxication. The effects of contrast media was dependent on the time of application, their concentration and conditions of elimination organs. The value of contrast media effect was decreased in order: GdCl3, bilignost, triombrast, iogexol, omnipaque. Gd-DTPA did not influence lipid peroxidation in any cases.

[The effect of x-ray contrast media on the amount of thromboxane and prostacyclin in the blood of man and rats in vivo and in vitro]. / Vliianie rentgenokontrastnykh sredstv na kolichestvo troboksana i prostatsiklina v krovi u cheloveka i krys in vivo i in vitro.

The in vivo and in vitro effects of radioopaque agents such as bilignost, iodamide, and triombrast on blood thromboxane B2 (TxB2) and prostacyclin levels were studied in man and rats. These radioopaque agents were demonstrated to increase prostacyclin levels and to decrease TxB2 in the plasma by 40%, as evidenced by urography when given in vivo (1-2 g/kg) and in vitro (2.5.10(-2) M and 2.5.10(-3) M).

[The effect of x-ray contrast media on the spontaneous hemolysis of human erythrocytes and the possible regulatory pathways]. / Vliianie rentgenokontrastnykh sredstv na spontannyi gemoliz éritrotsitov cheloveka i vozmozhnye puti ego reguliatsii.

It was shown that bilignost, in contrast to triombrast, iodamide and metrizamide precipitates spontaneous hemolysis of human erythrocytes. The hemolytic effect of bilignost may be decreased by means of pipolphen and prednisolone or by using the mixture of albumin + glycerin + sodium chloride + bilignost.

[Effect of roentgenocontrast agents on bilirubin absorption by liver sections of rats]. / Vliianie rentgenokontrastnykh sredstv na pogloshchenie bilirubina srezami pecheni krys.

Spectrophotometry was employed to study the effect of radiographic contrast agents (iopanoic acid, bilimin, bilignost, endobil, biligram, verografin, iodamide) on bilirubin absorption by rat liver sections. It was discovered that lopanoic acid, bilignost, endobil, biligram, iodamide and verografin inhibit bilirubin absorption by rat liver sections by the competitiveless while bilimin by the noncompetitive mechanism.