Search PubMed⌕ Search

Biomedical subjects

M Markov

Publications and source records attributed to M Markov.

At least 19 recordsLinked to original sources
PubMed2006

Incomplete myocardial rupture following inferior myocardial infarction: a case report.

In an era of early and invasive therapeutic approaches, myocardial rupture has become an uncommon complication of myocardial infarction. While septal wall rupture most often leads to devastating haemodynamic consequences, free wall rupture is usually fatal. We report a case of a 48-year-old man in whom an incomplete myocardial rupture located in the inferior part of the interventricular septum was promptly detected during the acute phase of an inferior myocardial infarction treated by early percutaneous coronary angioplasty. A conservative rather than a surgical approach was decided with a favourable short-term outcome.

Coronary Angiography↗
PubMed2004

Molecular signals for late Tertiary/early Quaternary range splits of an Eurasian steppe plant: Clausia aprica (Brassicaceae).

Several vegetation belts stretch continuously from Europe to Asia, taiga and steppe being most prominent. Numerous plant species within these belts share a conspicuous distribution area, which is longitudinally contracted or disrupted approximately along longitude 70 degrees E. To date no hypothesis for this intriguing distribution pattern has been put forward. We detected molecular footprints in the contemporary genetic composition in nuclear DNA (ITS1, ITS2) and chloroplast DNA (trnL-trnF spacer region) of the steppe element Clausia aprica (Brassicaceae) providing evidence for a severe longitudinal range split and genetic differentiation east of the Ural Mountains about 1 million years ago caused by Quaternary climatic oscillations. Clausia aprica provides the first phylogeographical analysis on the intraspecific evolution of an Eurasian steppe plant.

Asia↗
PubMed2001

Effects of permanent magnets on resting skin blood perfusion in healthy persons assessed by laser Doppler flowmetry and imaging.

Effects on skin blood perfusion of permanent ceramic magnets [0.1 T (1000 G) surface field], individually (disk shaped, 4 cm diameter x 1 cm thick) or in the form of a 11 x 7 in pad ( approximately 28 x 17.8 cm) with an array of 16 rectangular magnets (4.5 x 2.2 cm), were investigated in 16 female volunteers (27.4 +/- 1.7 years, range 21-48 years) using three separate protocols. In protocol A, a disk magnet was placed on the palmar surface of the hand in contact with the thenar eminence (n = 5). In protocol B, the magnet was placed on the hand dorsum overlying the thenar eminence (n = 5). In protocol C, the entire palm and fingers rested on the magnetic pad (n = 6). Magnets were in place for 36 min on one hand, and a sham was in place on the other hand. Blood perfusion was measured on the middle finger dorsum by laser Doppler flowmetry (LDF) and on the index finger by laser Doppler imaging (LDI). Perfusion measurements were simultaneously taken in sham and magnet exposed hands, before and during the entire magnet exposure interval. Magnetic field effects were tested by comparing skin blood perfusion sequences in magnet and sham exposed regions. Results showed no significant changes in either LDF or LDI perfusion at magnet or sham sites during exposure, nor were there any significant differences between sham and magnet sites for any protocol. Measurements of skin temperature at the LDF measurement sites also showed no significant change. It is concluded that in the healthy subjects studied with normal, unstressed circulation, magnets of the type and for the duration used, showed no detectible effect on skin blood perfusion in the anatomical area studied.

Adult↗
PubMed1995

Proper measurement of blood pressure and heart rate in SHRSP and WKY by an indirect volume-oscillometric method.

1. The effect of environmental temperature on the indirect measurement of rat blood pressure and heart rate was investigated with special reference to the tail arterial blood flow in both strains of SHRSP and WKY. 2. Very good correlations (r > 0.82, P < 0.05; t-test, 10 d.f.) were observed between the two values of systolic blood pressure or heart rate measured by a direct and an indirect method at environmental temperatures between 26 and 38 degrees C in SHRSP, and 34 and 38 degrees C in WKY, respectively. 3. When the temperature was elevated by 10 degrees C from 25 degrees C to 35 degrees C, the regional blood flow in the tail artery increased by 52-69%, sufficient to detect a blood flow increase by the indirect method. 4. These data showed that the best way to measure the accurate blood pressure and heart rate in both strains of SHRSP and WKY by the indirect volume-oscillometric method was to hold the rats at 34-36 degrees C for 5 min.

Animals↗
PubMed1995

Renin-angiotensin system in the antihypertensive effect of isoteoline in spontaneously hypertensive rats.

1. The aim of the present study was to examine the effects of isoteoline (IST), a new tetrahydroaporphine derivative, on the blood pressure and some of the components of renin-angiotensin-aldosterone system (RAAS) in spontaneously hypertensive rats (SHR). 2. After long-term treatment (14 days, 3 times daily) in a dose of 1 mg/kg orally and intraperitoneally, IST induced a significant decrease of the systolic blood pressure (SBP) in SHR (from 192 +/- 2 to 155 +/- 5 mgHg). 3. At the same time, IST induced a significant decrease of the levels of plasma renin activity (PRA) and aldosterone (ALD) and manifested a trend to increase the sodium plasma level. 4. These results indicate that IST after chronic long-term treatment induced a marked antihypertensive effect and inhibited the components of RAAS in SHR. Apparently, the long-lasting antihypertensive effect of IST in SHR was mediated and realized in part by inhibition of the components of RAAS.

Aldosterone↗
PubMed1993

[A pharmacological study of the hepatoprotective activity of fructose-1,6-diphosphate].

A fructose-1,6-diphosphate preparation was tested for hepatoprotective activity through biochemical and morphologic studies in experiments on Wistar rats sustaining D-galactosamine- and paracetamole-induced hepatotoxicity. Findings indicated the modeled hepatic lesions to be readily reproducible, to simulate some characteristics of human liver pathology, and to be suitable for testing substances expected to have hepatoprotective action; intraperitoneal administration of fructose-1,6-diphosphate at a dose of 1000 mg/kg body weight proved moderately protective against liver damage by D-galactosamine; the benefit observed concerned mostly dystrophic and inflammatory changes in the liver; in a number of cases, correlation was noted between biochemical serum parameters and pathomorphologic liver alterations.

Acetaminophen↗
PubMed1990

[The effects of compound IZ35 on the beta-adrenergic mediator system].

The biological activity of the compound Iz35, representing rigid conformer of triquinol in respect to the cardiovascular system and smooth musculature, was studied. The arterial blood pressure and heart frequency were recorded in cats and rabbits as well as the tonus of smooth musculature of bronchial tree, uterus and intestines in experiments in vivo and in vitro of rats, guinea pigs and rabbits. It was established that the compound Iz35, administered in a wide range of doses of 0.1-5 mg/kg intravenously lowered systolic arterial blood pressure, but did not change chronotropic function of the heart (statistically significantly) in contrast to isoprenaline and thymolol. The compound Iz35 and trinquinol, administered intravenously in doses off 0.01-0.1 mg/kg, manifested broncholytic effect in experiments in vivo on various models of experimental bronchospasm of guinea pigs. They had still marked spasmolytic activity (1 x 10(-9)-1 x 10(-6) g/cm2 in respect to stomach-intestinal and uterine smooth musculature. The effects of Iz35 on the cardiovascular system and smooth musculature were inhibited considerably on the background of beta-adrenergic blockade (propranolol) in comparison with triquinol. The obtained data as well as our previous studies suggest to accept that these effects of the compound Iz35 are connected mainly with affecting beta-adrenergic mediator system and it manifests double agonistic/antagonistic activity in accordance with its dose characteristic.

Animals↗
PubMed1990

[The effects of isotheoline (IST) on the nonvascular smooth musculature].

The influence of IZT on nonvascular smooth musculature in experiments in vitro was studied: on isolated intestine of the rabbit, ileum of the guinea pig, an uterine horn of the rat and guinea pig, vas deferens of the rat; as well as in vivo: on an experimental model of bronchospasm of guinea pigs, induced by acetylcholine, histamine and serotonin. Isometric contractions were recorded, and in the experiments in vivo--the tonus of the bronchial smooth musculature by a piston recorder. The obtained results showed that in experiments in vitro IZT increased the dose dependent tonus of intestinal smooth musculature; inhibited predominantly at low concentrations like clonidine the contractions of vas deferens of the rat by low frequent field stimulation--0.1 Hz and its influence was weak in respect to contractions of this organ, induced by high frequent field stimulation (10 Hz); inhibited the contractions of vas deferens in response to exogenously administered NA. IZT inhibited only bronchoconstrictor effect of serotonin in experiments in vivo. It was established that the effects of IZT both in respect to the vascular and to the nonvascular smooth musculature were Ca++ dependent and were connected with pre- and postsynaptic alpha-adrenergic receptors.

Animals↗
PubMed1990

[A neuropharmacological study of isoteolin (IST)].

Neuropharmacological study of IST was carried out on mice and rats, using the so-called practically "blind" neuropharmacological screening of M. Nikolova and L. Daleva (1968). The investigated product IST was administered under the form of 0.1-1% of solutions prepared ex tempore with saline in doses, equivalent to 1/440-1/250 to 1/2-4 1/2-4/5 of LD50. The studies on behaviour profile of mice and rats showed that IST induced symptoms of increasing inhibition of the central nervous system (CNS) in conformity with an increase in the dosage. It was established that IST inhibited dose-dependent spontaneous and stimulated with amphetamine motor activity and orientation reaction of mice, antagonized group amphetamine toxicity and excitatory effects of amphetamine as well as of morphine on mice; potentiated hexobarbital narcosis of mice and rats; lowered body temperature of rats; elevated the threshold of pentetrazolic seizures. In very high doses (50, 100 and 200 mg/kg i.p.), equivalent to 1/5 to 2/3 of LD50 IST induced excitatory effects on central and peripheral nervous system-provoked unaddressed aggressiveness, salivation, increased frequent breathing and chromodacryorrhea [correction of chromodacriurea]. The obtained experimental results show that IST manifest central depressive effect and has mainly neuroleptic character in respect to CNS.

Animals↗
PubMed1990

[The anti-arrhythmia activity of isoteolin (IST)].

The antiarrhythmic activity of IST was studied on some experimental models of cardiac arrhythmia--caused by adrenaline in rats, caused by barium in non-narcotized rabbits, caused by strophanthin in guinea pigs, caused by aconitine and calcium in rats. Rhythmic disturbances were recorded by a 12-channel polyphysiograph "Galileo" or a single-channel electrocardiograph "Cardiomat". The obtained results showed that IST manifested antiarrhythmic activity in respect to adrenaline, barium and strophanthin arrhythmias without affecting substantially aconitine and calcium arrhythmias. It is thought that antiarrhythmic activity of IST, found in the indicated experimental models of cardiac arrhythmias, is most probably connected with a lowering of the peripheral sympathetic activity, realized by a central way.

Aconitine↗
PubMed1989

[The possible effect of a ketotifen preparation on beta-receptor blockade].

Parallel clinico-pharmacological studies were carried out of ketotifen action in patients with atopic bronchial asthma and in an experimental model of beta-adrenergic blockade in guinea pigs. The results revealed that ketotifen acts on the beta-adrenergic blockade in the patients with atopic bronchial asthma and in the experimental model in guinea pigs. The ketotifen action on beta-adrenergic blockade resembles that of glucocorticosteroids in efficiency.

Adrenergic beta-Antagonists↗
PubMed1988

Effects of compound IS-35 on intraocular pressure.

The influence of compound IS-35 on intraocular pressure of unanesthetized rabbits was studied. In some cases intraocular pressure was measured with either the tonometer of Schiotz and was calculated in mmHg according to Leydhecker's scale (1973), or with the tonometer of Maclakov. Intraocular pressure was measured before and at 30, 60, 120, 180, 240 and 360 min after topical application of IS-35, timolol and trimetoquinol. It was established that IS-35 applied locally in the eye as 0.5% solution or collyrium decreases statistically significantly intraocular pressure. This effect was similar to that of timolol and exceeded significantly the effect of trimetoquinol. The experimental study on the beta-adrenergic adenylate cyclase showed that the mechanism of action of IS-35 on ophthalmotonus most probably is similar to the effect of timolol and is due to the suppression of aqueous humor formation.

Administration, Topical↗
PubMed1984

Neuro-endocrine effects of isotheoline.

Experiments are carried out to study the effect of isotheoline (IST) on the secretion of prolactin (PRL), somatotrophic hormone (STH) and testosterone, using cats and Wistar albino rats of both sexes. PRL, STH and testosterone using cats and wistar albino rats of both sexes. PRL, STH and testosterone were determined radioimmunologically at the 10th, 60th and 120th min after the administration of IST in doses of 0.5 to 5 mg/kg. Comparative experiments were carried out with bromocryptine and glaucine--1 mg/kg i.p., as well as experiments involving the administration of IST on the background of the dopaminergic antagonists haloperidol and pymoside--1 mg/kg i.p. The results obtained show that in doses not exceeding 1 mg/ks IST increases the plasma level of testosterone and, similar to bromocryptine, reduces the plasma level of PRL and increases that of STH. These effects are less pronounced for the 5 mg/kg dose and they are antagonized by the dopaminergic antagonists used. It is assumed that IST, similar to bromocryptine, achieves the described effects through selective stimulation of the D2 dopaminergic receptors involved in neuro-endocrine mechanisms responsible for the control and release of the hormones studied.

Animals↗