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Biomedical subjects

S E Ragimov

Publications and source records attributed to S E Ragimov.

At least 19 recordsLinked to original sources
PubMed1992

Beta-blockers: propranolol, metoprolol, atenolol, pindolol, alprenolol and timolol, manifest atherogenicity on in vitro, ex vivo and in vivo models. Elimination of propranolol atherogenic effects by papaverine.

The addition of the beta-blockers propranolol, metoprolol, atenolol, pindolol, alprenolol and timolol to a culture of peritoneal macrophages or smooth muscle cells induced an increase in the intracellular cholesterol content. Blood serum obtained from a rabbit after a peroral administration of beta-blockers also induced cholesterol accumulation. This property of drug or blood serum obtained after peroral administration is conventionally referred to as atherogenic potential or atherogenicity. Regular administration of propranolol during a 21-day period evoked stable atherogenicity of rabbit blood serum. This was accompanied by stimulation of manifestations of atherosclerosis in the aorta deendothelialized with a balloon catheter. Propranolol increased neointimal thickening, lipid accumulation, an increase in cell number and in the collagen content. In vitro, the combination of propranolol with papaverine eliminated the atherogenic effect of propranolol which manifested itself as stimulation of cholesterol accumulation in cultured cells. Simultaneous peroral administration of propranolol and papaverine prevented the appearance of serum atherogenicity. Papaverine eliminated neointimal thickening, an increase in cell number and in the lipid and collagen contents evoked by propranolol. Papaverine itself had no effect on these parameters. Thus, the atherogenicity of propranolol as well as capacity of papaverine to eliminate beta-blocker atherogenicity revealed in cell culture was confirmed in vivo. We hope that these results may be useful in the development of new drugs and optimization of antiatherosclerotic drug therapy.

Adrenergic beta-Antagonists↗
PubMed1992

[The structure of the endothelialized and nonendothelialized areas of myointimal thickening of the rabbit aorta].

De-endothelialization of the abdominal aorta of the rabbit was performed with a balloon catheter. As a result, a partially endothelialized myointimal thickening was formed consisting of smooth myocytes and macrophages. As compared with the zone devoid of the endothelium the endothelialized zone was characterized by less thickness and by the presence of an additional elastic membrane. Great amount of leukocytes and solitary thrombocytes were adhesed just in the place of contact. In the center of nonendothelialized zone no adhesion was observed. In the zone covered by the endothelium smooth myocytes of the synthetic and contractile phenotype were seen with similar frequency. The nonendothelialized zone was presented mainly by smooth myocytes of the synthetic phenotype and macrophages. The myointimal thickening of the rabbit aorta might be considered as an informative model for analysis of myoendothelial interactions.

Animals↗
PubMed1991

[The cellular polymorphism of the myointimal thickening in the rabbit aorta].

Partly endothelialized myointimal thickening formed in rabbit aorta after balloon catheter injury. It was populated by cells of different shape. There were spindle-shaped cells. Y-shaped cells, cells of irregular shape with processes and stellate-shaped cells. As a rule stellate cells situated just near the endothelium. It is supposed, that the endothelium can influence the shape of myointimal cells.

Animals↗
PubMed1991

[Atherogenic effect of beta-blocker propranolol revealed in the rabbit denudated aorta].

The influence of beta-blocker propranolol onto atherogenic properties of blood serum and to formation of myointimal thickening in rabbit aorta, which was caused by denudation, were investigated. The preparation was introduced per os in the dose 6 mg/kg. Culture of mouse peritoneal macrophages was used to estimate the atherogenic properties of the serum. Serum of propranolol-treated rabbits induced accumulation of cholesterol in cultivated cells. Propranolol also induced an increase of the thickness of aortic intima, lipid accumulation and increasing of cell's number in myointimal thickening. Thus, atherogenic effect of beta-blocker propranolol was found both in vitro and in vivo.

Administration, Oral↗
PubMed1991

[Structure of the neointima after balloon catheter injury of the rabbit aorta in the context of hypercholesterolemia: analysis of endothelial influence on lipid accumulation].

Balloon catheter de-endothelialization of abdominal aorta of cholesterol-fed rabbits was performed. As a result, partly endothelialized neointima was formed, consisting of smooth muscle cells and macrophages. Neutral lipids stored more intensely in non-endothelialized part of neointima. Preferential intracellular lipid accumulation in this area was observed while predominantly extracellular lipid accumulation was found in endothelium-covered part of neointima. It is supposed that endothelium inhibits intracellular lipid accumulation and at the same time stimulates an extracellular one, but as a whole it reduces the density of lipid inclusions in neointima.

Animals↗
PubMed1990

Local prevention of thrombosis in animal arteries by means of magnetic targeting of aspirin-loaded red cells.

Thrombosis was induced in 18 dog and 16 rabbit arteries by surgically inverting a vascular wall flap into its lumen. A completely occluding red thrombus was formed inside the vessel 4 to 5 hours later in 80% of cases. SmCo5 magnet was secured externally to one of the arteries. The constant magnetic field produced by the magnet had no influence on the clot formation. Autologous red cells loaded with ferromagnetic colloid compound and aspirin were administered intravenously and completely aborted arteriothrombosis on magnet-supplied side with no deterioratory effect on clot formation in the control artery.

Animals↗
PubMed1989

[Laser angioplasty of peripheral arteries].

The first experience in laser angioplasty of the superficial femoral artery in 5 patients is discussed. Local occlusion or critical stenosis (90% and more) of the vessel with signs of disturbed blood supply to the limb were the indications for the intervention. For conducting laser angioplasty the authors used an AIG-neodymium laser (1.06 microns) and a light guide of their own design which allowed a canal of no less than 3.1-3.9 mm in diameter to be formed in the plaque. Patency of the artery was restored in all 5 cases and a satisfactory clinical effect was produced. Thrombosis of the recanalized segment occurred on the 12th day after angioplasty in one case. The prospects of the method and the means of further studies are discussed.

Angioplasty, Balloon↗
PubMed1988

Comparison of different lasers in terms of thrombogenicity of the laser-treated vascular wall.

The thrombogenic properties of the laser-treated vascular wall are reported as quantitatively assessed on the basis of 33 experiments with peripheral canine vessel segments. Three types of surfaces, namely, 1) intact, 2) mechanically de-endothelized, and 3) postlaser, have been simultaneously exposed to platelet-enriched plasma in a sequentially organized artificial circulation system. Then the adherent platelets have been counted on the treated surfaces, and the relative thrombogenicity index has been calculated according to the equation T = (A1 - Aint)/(Ad - Aint), where Aint, Ad, A1 = the adherent platelet counts on intact, mechanically de-endothelized, and laser-treated surfaces, respectively. The following lasers have been evaluated: 1) Nd-YAG, 1,060 nm, continuous wave, 4W; 2) argon-ion, 480 and 514 nm and argon-ion, 350 nm, continuous-wave, 1 W and 400 mW [corrected], respectively; 3) excimer XeCl, 308 nm, pulsed, 30 mJ per pulse, repetition rate 10 Hz [corrected]; and also 4) the laser-heated metal probe (2 mm diameter, Trimedyne, Nd-YAG) 1,060 nm, 8 W. The thrombogenicity index values obtained were 83 +/- 7, 72 +/- 8, 57 +/- 9, 63 +/- 7, and 82 +/- 9%, respectively. The differences between these values were statistically insignificant. The data are suggestive of the essential requirement of, at least, anticoagulant therapy after laser angioplasty irrespective of the laser type.

Animals↗
PubMed1988

Magnetically driven thrombolytic preparation containing immobilized streptokinase-targeted transport and action.

Streptokinase was immobilized on the magnetic carrier at a concentration of 2,000-2,700 IU/ml of preparation. Thrombosis was induced in both canine carotid arteries by means of the vascular wall flap inverting into its lumen. The red, completely occluding thrombus was formed inside the vessel 4-5 h later. A samarium-cobalt magnet was secured externally to one of the arteries. After the clot formation the magnetically immobilized streptokinase was injected intravenously. The preparation concentrated in the region of the magnetic field action caused complete thrombus degradation and normal blood flow restoration; no effect on the clot in the control artery was observed.

Animals↗
PubMed1988

[Thrombolytic action of urokinase preparation covalently bound to modified thrombin].

Urokinase was covalently bounded with modified thrombin. Thrombin was modified by carbodiimide and 1, 12-dodecamethylenediamine. In this conjugate thrombin is not catalytically active and does not induce platelets aggregation. The catalytic properties of modified urokinase do not essentially differ from native enzyme but its thermostability increases. The modified urokinase thrombolytic effect is at least 10-fold higher than the native one. In femoral arteries of experimental thrombosis the conjugate urokinase-thrombin brings about total thrombolytic effect as early as 1.5 hours after injection (2500 IU per 1 kg of the animals weight). The causes of the observed effect were discussed.

Animals↗
PubMed1988

[Clinical and hemodynamic evaluation of the effectiveness of plasmapheresis in high arterial hypertension refractory to drug treatment agents].

Indices of central hemodynamics based on tetrapolar rheography results with subsequent calculation of left ventricular post-load characteristics were studied in parallel with the assessment of clinical efficacy of plasmapheresis in 36 patients with therapy-resistant severe arterial hypertension. Plasmapheresis in severe arterial hypertension resulted not only in BP reduction and overcoming of refractoriness to medical therapy but also produced a beneficial effect on the cardiovascular system improving left ventricular post-load characteristics.

Adult↗
PubMed1988

[Thrombogenic properties of the inner vascular surface following laser exposure].

Laser angioplasty, using YAG-neodymium laser and a balloon catheter with monofiber quartz light guide (400 micron), introduced into its central canal, was performed in 8 dogs with thromboses of 11 femoral or carotid arteries. Average energy expenditure for recanalization was 26 +/- 4 J, with 4.9 +/- 0.3 W and exposure time of 5.1 +/- 0.7 s. Re-thrombosis developed after 5 to 10 days in all arteries, left in the circulation network after laser angioplasty. The latter part of the study is dealing with the assessment of the surface of femoral or carotid arteries of the dogs after laser exposure. This was done by quantitation of the adhered platelets after platelet-enriched plasma was circulated through vessels, whose inner surface was 1) intact, 2) de-endothelized, or 3) laser-damaged, using a scanning electron microscope. The thrombogenic index was 65-96, 85 and 66%, respectively, for the YAG-neodymium, argon and eximeric (XeCl) lasers.

Animals↗
PubMed1987

[Local prevention of thrombosis in the dog carotid artery using magnetically concentrated erythrocytes loaded with aspirin].

Thrombosis was induced in both canine carotid arteries by means of vascular wall flap inversion into their lumens. A red, completely occluding thrombus was formed inside the vessel 4 to 5 hours later. SmCo5 magnet was secured externally to one of the arteries. The constant magnetic field produced by the magnet had no influence on the clot formation. Autologous red cells loaded with ferromagnetic colloid compound and aspirin were administered intravenously through the hind paw route; total aspirin pool was 20 micrograms. Circulating magnetically-charged red cells have been earlier shown to concentrate in a canine artery in the constant magnet area. The administration of magnetically-charged red cells loaded with aspirin completely prevented arterial thrombosis in the magnet-supplied artery, having no detrimental effect on clot formation in the control artery.

Animals↗