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Biomedical subjects

R A Serov

Publications and source records attributed to R A Serov.

At least 19 recordsLinked to original sources
PubMed1998

Comparative assessment of hepatic Glisson's capsule and bovine pericardium in heart valve bioprostheses.

BACKGROUND AND AIM OF THE STUDY: The optimal material for heart valve bioprostheses remains disputable. This investigation was initiated to compare the properties of hepatic Glisson's capsule, clinical experience of which in cardiovascular surgery is minimal, with those of bovine pericardium. METHODS: Hepatic Glisson's capsule was harvested from bull calves and used to create composite pulmonary arterial monocusp grafts and bioprostheses. Comparison of the strength and elastic properties of Glisson's capsule and bovine pericardium, as well as the hydrodynamic characteristics of valves made from these materials, was performed. Late results of operations using these materials were estimated echocardiographically. RESULTS: Although Glisson's capsule tissue is thinner than the bovine pericardium, its elasticity modulus is greater. However, the hydrodynamic characteristics of heart valves made from either tissue are similar. Moreover, valves made from Glisson's capsule have a lower systolic pressure gradient on the prosthesis and a higher effective orifice area. Composite pulmonary arterial xenopericardial grafts with a monocusp of Glisson's capsule were used in 30 patients during tetralogy of Fallot repair. Glisson's capsule was also used for tricuspid valve reconstruction and as a bioprosthesis in six patients with Ebstein's anomaly. At 1-2 years after surgery, the Glisson's capsule tissue remained thin and flexible, with no calcification. CONCLUSIONS: Although the hydrodynamic properties of hepatic Glisson's capsule and the bovine pericardium are similar, the capsule tissue is thinner and has a greater elasticity modulos. Thus, Glisson's capsule may be used for bioprosthesis construction both independently and in combination with bovine pericardium.

Animals↗
PubMed1992

[The causes of cerebral complications in patients with ischemic heart disease following myocardial revascularization operations].

In the period from Jan. 1988 to Jan. 1991 operations for the formation of an aortocoronary shunt were carried out in 437 patients at the Department of Combined Affections of the Coronary and Peripheral Arteries, Bakulev Research Institute. In some cases the operation was combined with resection of a postinfarction aneurysm of the left ventricle. Cerebral complications developed in the postoperative period in 28 (6.4%) patients. Their analysis showed the prevalence of severe forms of consciousness disturbances: coma and comatose states were encountered in 85.7% of cases. The main causes of the complications were acute heart failure (64.3%) and arterial embolism (14.3%). In only one case concomitant affection of the branches of the aortic arch was found to be the main cause of the development of a transitory ischemic attack. It is concluded that the development of acute heart failure in the patients may sharply increase the incidence of neurologic complications.

Aorta, Abdominal↗
PubMed1991

[Alterations of the myocardium and adrenergic nerves of the isolated rat heart under conditions of total ischemia and normothermic cardioplegic reperfusion].

The increase of the ischemic period from 30 to 60 min did not enhance the degree of the contractural myocardial damage in connection with progression of "no reflow" phenomenon. Endogenous catecholamines do not play a decisive role in genesis of ischemic (reperfusion) heart damage. Cardioplegic reperfusion with a high K+ content results in a considerable loss of mediator from the adrenergic nerve fibres thus leading to the partial isolated heart desympathization.

Animals↗
PubMed1991

[Reaction of the sympathetic-adrenal medulla system in young rats of different age to subcutaneous administration of a cardiotoxic dose of noradrenaline].

A quantitative histo-fluorescent investigation of the adrenal medulla and cardiac sympathetic nerves in young rats of various age has demonstrated a high degree in development of the adrenal medulla and a low density in arrangement of fluorescent nervous terminals in the ventricular myocardium in 3-week-old rats. During this period the animals show a low sensitivity to the catecholamine stress. At the age of 1.5 months the development of the sympatho-adrenomedullary system reaches the level specific for a mature animal; sensitivity to the norepinephrine stress increases noticeably, manifesting as a sharp activation of catecholamines secretion by the adrenal medulla and a high lethality.

Adrenal Medulla↗
PubMed1991

[Changes in the sympathetic-adrenal system during stress in rats with high and low resistance to acute hypoxia].

Quantitative luminescent microscopy was used to examine the sympathetic system of cardiac ventricles (SSCV) and the adrenal medulla (AM) of adult Wistar male rats high-resistant (HRH) and low-resistant (LRH) to acute hypoxia and exposed norepinephrine (NE) stress. The relative area of fluorescence adrenergic terminals (RAFAT) of the ventricles and AM catecholamine levels (CL) were shown to be equal in control HRH and LRH rats. The LRH rats displayed a two-phase SSCV response in the first 6 hours of NE stress. Their RAFAT rose an hour later and their RAFAT in the basal zone of the left ventricle insignificantly exceeded that of HRH rats, RAFAT in the latter being unchanged by that time. At hour 6, the heart RAFAT decreased as compared to 1-hour and control levels in LRH and HRH rats and became equal in the two groups. The AM CL in LRH and HRH rats remained unaltered within the whole period of the examination. Despite the profound differences in the resistance of HRH and LRH rats to hypoxia, the responsiveness of their sympathoadrenal system (SAS) to stress is rather homogeneous. With stress, the sympathetic link of SAS is more labile than the adrenal one.

Acute Disease↗
PubMed1988

[Role of non-coronarogenic injuries of the myocardium in sudden death at various stages of postnatal ontogenesis].

The study was performed on white inbred young (1 and 3 weeks old), sexually immature (1.5 months old), sexually mature (6 months old) and old (over 24 months old) male rats, who were subcutaneously administered noradrenaline at a dose of 2 mg/kg body weight. The degree of myocardial injury was assessed on frontal histotopographic heart sections stained by the method of Leigh and Regaud, obtained from dead and killed rats 6 hours after noradrenaline injection. The reaction of the adrenal cortical substance was investigated, using quantitative histofluorescent method. It has been shown that young rats have low sensitivity to catecholamine stress, with the sensitivity increasing by the period of sexual maturation and again decreasing in old animals. The animals' death is associated with higher degree of myocardial injury that accompanies a drastic increase in catecholamine secretion by the adrenals.

Age Factors↗
PubMed1987

[The adrenal medulla and adrenergic innervation of the ventricles of the heart during the postnatal period of ontogenesis of the white rat (histofluorescent study)].

The sympathetic innervation of the cardiac ventricles and dynamics of catecholamine contents in the adrenal medulla have been investigated in inbred white rats (1-3-week-old, immature, mature and old animals). During 1-3 weeks of age, development of adrenergic innervation of the heart is observed, in 1.5-month-old rats in approaches that in mature animals. In the old rats the arrangement density and fluorescent intensity of the adrenergic terminals of the cardiac ventricles in comparison to those in the mature animals decreases considerably. Catecholamine contents in the adrenal medulla in 3-week-old rats practically reaches those specific for mature animals. In the old animals the amount of catecholamines in the adrenal medulla decreases by 20%, comparing to those in the mature animals. Thus, maturation of the mediator link of the sympatho-adrenomedullary system is performed in it later than the hormonal one, while processes of old age involution are more intensive.

Adrenal Medulla↗
PubMed1985

[Prostaglandin and cyclic nucleotide content of the ventricular myocardium in noradrenaline damage to the heart].

The effect of intraperitoneal noradrenaline injection (2.5 mg/kg body weight) on myocardial levels of cAMP, cHMP, PGE and PGF2 alpha of the left and right ventricles was examined in male Wistar rats. The findings were compared with morphologic changes in the myocardium and sympathetic nerves of both ventricles. Cyclic nucleotides and PGs were measured by RIA, sympathetic nerves, by a fluorescent histochemical technique; myocardial lesions were demonstrated by Lie-staining. A sharp drop was noted in cAMP and PG levels at early stages of the experiment followed by a gradual return to control values. The decrease in cAMP was less marked, and more transient, in the right ventricle. These changes were accompanied with a more pronounced damage to the left ventricle, perhaps due to differences in adrenergic innervation as well as cyclic nucleotides and PG metabolism in the examined compartments of the heart.

Animals↗
PubMed1984

[Is the damaging action of catecholamines on the myocardium realized via hyperstimulation of the beta receptors?].

Experiments on an isolated rat heart were made to compare the damaging action on the myocardium of catecholamines (noradrenaline, adrenaline and isoproterenol) differing in the affinity for beta-receptors. The damage to myocardial cells was evaluated from the release into the perfusate of intracellular enzymes (creatine phosphokinase and lactate dehydrogenase) and the number of contracture damaged myocytes. Noradrenaline exerted the most powerful damaging action on the myocardium at a concentration of 10(-6) M. Perfusion of the heart with isoproterenol at concentrations of 10(-6) M and 10(-5) M did not lead to the affection of cardiomyocytes. It was isoproterenol concentration exceeding noradrenaline concentration 100 times that produced an increase in the rate of the release of the enzymes to the perfusate and a rise of the number of contractures in the myocardium, with the above increase being less than that provoked by adrenaline and noradrenaline (10(-6) M). It is concluded that the mechanism of the cardiotoxic effect of catecholamines cannot be reduced only to their effect on myocardial beta-receptors.

Animals↗
PubMed1981

[Dynamics of a necrotic focus development based on data from determining the activity of the MB CPK fraction and from precardiac mapping].

In the 26 patients dead during the acute (necrotic) period of the disease comparisons in the changes of activity of MB CPK and the data of the precardial charting with the results of the histological analysis of the hearts is made. The histological analysis served to assess the date of the necrosis in different areas of the heart. It is established that the repeated rises of activity of MB CPK and the increase in the number of the complexes QS are determined by the development of new foci of necrosis.

Adult↗
PubMed1980

[Catecholamine concentration in blood, heart, and adrenals of rats following intraperitoneal injections of a cardiotoxic dose of adrenaline against a background of arfonad and rausedyl administration].

A study was made of the adrenaline and noradrenaline content in the blood, myocardium and adrenals of 74 male Wistar rats. Four series of experiments were conducted with administration of noradrenaline alone and noradrenaline after premedication with arfonad (ganglion-blocking agent) or rausedil (reserpine drug). Distilled water was used in control experiments. The content of adrenaline and noradrenaline in blood and tissues was shown to change 45 seconds after noradrenaline administration and to return to normal by the 7th minute. Correlation of the catecholamine content in rat blood and tissues with morphological changes in the myocardium recorded in the analogous series of experiments has shown that the increased content of catecholamines in bloods is one of the most important factors in the pathogenesis of myocardial injury since the diminution of their content during ganglionic blockade is associated with a reduced heart injury. The noradrenaline content in the myocardium does not correlate with the severity of myocardial injury.

Adrenal Glands↗
PubMed1977

[Staining with hematoxylin--basic fuchsin-picric acid (HBFP) for detection of myocardial lesions of different etiology].

The article discusses advantages of the so-called fuchsinorrhagic method offered by Lie et al. in 1971. Areas of the necrotized muscle obtained at autopsy of 11 individuals who had died of myocardial infarction of various periods of duration, 12 biopsy specimens of the myocardium obtained during the operation for correction of congenital heart defects of the type of Fallot's tetrad and isolated defects of the septum with various periods of extracorporeal circulation and hearts of 35 male Wistar rats with a damaged myocardium (lesions being induced by intro-abdominal injection of noradrenalin in a dose of 2.5 mg/kg), which were sacrified 6 hours following the exposure to noradrenalin, were studied. The method of staining with HBFP makes it possible to detect both ischemic and noncoronarogenic lesions of the myocardium; moreover, in this method erythrocytes, fibrin, and connective structures get also stained, which makes a complex study of morphology of the myocardium feasible.

Animals↗