[Electrophysiological changes of atria leading to inefficacy of preventive antiarrhythmic therapy].
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Anti-Arrhythmia Agents↗
Biomedical subjects
S V Popov
Publications and source records attributed to S V Popov.
[Prostanorm in the treatment of chronic non-infectious prostatitis].
AIM: To try efficacy of prostanorm against chronic non-infectious prostatitis (CNIP). MATERIAL AND METHODS: Forty two 25 to 48 year old patients with CNIP received prostanorm treatment: 2 tablets, 3 times a day 30 min before meal or 40 min after meal for 6 weeks. RESULTS: Prostanorm relieved symptoms significantly and improved quality of life, reduced prostatic size, increased maximal volumic speed of urine flow according to uroflowmetry. CONCLUSION: Prostanorm is an effective and safe drug for treatment of patients with CNIP.
Adult↗
[Special characteristics of pathogenesis of hypertension in personnel of radiation dangerous industry].
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Adult↗
All-fiber format compression of frequency chirped pulses in air-guiding photonic crystal fibers.
Air-cored, photonic band-gap crystal fibers exhibiting low nonlinearity and anomalous chromatic dispersion in spectral ranges inaccessible to conventional fibers can be used in the realization of all-fiber-format pulse compressors with unprecedented peak powers and wavelength diversity. Linear compression of inherently chirped and prestretched pulses by factors ranging from 20 to 80 around 1.0 and 1.5 microm have allowed generation of pulses as short as 163 fs. The results show that totally integrated femtosecond fiber laser sources can be realized throughout the visible and near-infrared and point to the possibility of megawatt peak and tens of watt average in-fiber power levels.
Journal Article↗
In vitro formation of mesenchymal bone marrow islets.
We studied the formation of mesenchymal islets in the culture of bone marrow cells in vitro. Islet-like structures detected on day 6 of culturing contained a central epithelioid cell (differing from macrophages and fibroblasts) surrounded with round mesenchymal cells. The number of mesenchymal islets increased on days 12-14 of culturing, but decreased to zero by the 24th day. They appeared not only as individual structures, but also entered the composition of colonies and formed assemblies with surrounding cells of different maturity. Our results show that mesenchymal islets serve as structural and functional units of mesenchymopoiesis.
Animals↗
[Effects of carvedilol, atenolol and their combination with fosinopril on cardiac rhythm variability, clinicofunctional status and quality of life in patients with postinfarction left ventricular dysfunction].
AIM: To study effects of carvedilol and atenolol and their combination with fosinopril on heart rhythm variability (HRV, clinicofunctional status and quality of life in postmyocardial infarction patients with moderate chronic cardiac failure (CCF). MATERIAL AND METHODS: An 8-week randomized open study enrolled 50 male patients (mean age 55.7 +/- 1.58 years) with postinfarction CCF. They were divided into two equal groups. Group one received carvedilol (24.4 +/- 2.0 mg/day) followed by addition of fosinopril (2.5-40 mg/day). Group 2 received atenolol (44.1 +/- 5.1 mg/day) followed by fosinopril in the same dose as in group 1. RESULTS: A 4-week therapy with carvedilol and atenolol effectively corrected depression of HRV in both the group. Combined therapy with these beta-adrenoblockers and fosinopril improved impaired global left ventricular contractility, exercise tolerance, quality of life, relieved symptoms of CCF. CONCLUSION: Carvedilol, atenolol and their combination with fosinopril in patients with postinfarction CCF improve clinico-hemodynamic and functional status, raise HRV and quality of life.
Antihypertensive Agents↗
Short-pulse, all-fiber, Raman laser with dispersion compensation in a holey fiber.
The use of Raman gain in conventional fiber followed by dispersion compensation in a holey fiber in a synchronously pumped laser configuration allowed compression by a factor of 8.5 of output pulses at a selected wavelength with respect to the pump pulses. We obtained 2-ps output pulses at 1.14 microm from a totally fiber-integrated laser pumped with 17-ps pulses at 1 microm. Higher pulse compression should be possible with nonlinear chirp compensation. Ultrashort-pulse, all-fiber Raman lasers at wavelengths shorter than 1.3 microm are feasible.
Journal Article↗
Continuous-wave, high-power, Raman continuum generation in holey fibers.
The possibility of using low pump power for cw Raman continuum generation is demonstrated by optimization of the pump peak power and by accounting for the loss-related reduction of the effective length of Raman interaction in holey fibers. A 3.8-W, 324-nm-wide cw Raman continuum with a spectral power density higher than 10 mW/nm is generated in a completely fiber-integrated, single-mode format.
Journal Article↗
[Effect of calcium antagonists verapamil and amlodipine on the risk of development of atrial fibrillation after coronary artery bypass grafting].
AIM: To assess effect of calcium antagonists amlodipine and verapamil on the risk of development of atrial fibrillation after coronary artery bypass surgery. MATERIAL: Of 74 patients subjected to mammary artery and venous coronary bypass grafting with the use of cardiopulmonary bypass 19 received amlodipine and 21 - verapamil. RESULTS AND CONCLUSION: Attacks of atrial fibrillation during 24 hour ECG monitoring were registered in 22.9% of patients mostly on days 2 and 3 after surgery. In verapamil treated patients atrial fibrillation occurred 1.5-2 times more often than in amlodipine treated patients or in patients receiving no calcium antagonists. This could possibly be explained by pronounced slowing of atrio-ventricular conduction by verapamil at the background of postoperative general "irritation" of the atrial myocardium.
Adult↗
[Development and implementation of new technologies into the cardiological and cardiosurgical practice].
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Animals↗
Effect of class III antiarrhythmic preparation nibentan on extrasystolic and post-extrasystolic contraction of rat papillary muscle.
The effect of nibentan (2.5 and 25 muM) on extrasystolic and post-extrasystolic contraction of isolated and perfused papillary muscle was studied. The muscle contracted in an isometric regimen at a rate of external electrical stimulation of 0.5 Hz in a temperature-stabilized chamber (36.0+0.5 degrees C). The extrasystolic contraction was induced with an extra electrical pulse applied 0.25 sec after the regular stimulus. Nibentan decreased the amplitude of extrasystolic contraction in a dose-dependent manner. At the same time, the effect of nibentan on extrasystolic contraction practically did not depend on its concentration. It is concluded that nibentan produces a dose-dependent effect on excitability of rat ventricular myocardium, and in parallel improves calcium-accumulating capacity of the sarcoplasmic reticulum in cardiomyocytes.
Animals↗
[Discussing SanPiNa project on luminance of occupational illumination].
The author analyzed San[symbol: see text]iNa project on luminance, considering its use for state epidemiology supervision practice and for work conditions assessment.
Humans↗
[The isolation, preliminary study of structure and physiological activity of water-soluble polysaccharides from squeezed berries of Snowball tree Viburnum opulus].
Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.
Adjuvants, Immunologic↗
[Structure and physiological activity of lemnan, Lemna minor L. pectin].
A pectic polysaccharide, lemnan, was isolated from freshly collected duckweed Lemna minor L. Its sugar chain was shown to be mainly composed of the residues of D-galacturonic acid (64%), galactose, arabinose, xylose, and D-apiose, a branched chain sugar. The high content of D-apiose (25%) indicated that lemnan is an apiogalacturonan type pectin similar to zosteran, a pectic polysaccharide from a sea phanerogam of the Zosteraceae family. The results of partial acidic hydrolysis, pectinase digestion, and NMR studies of lemnan demonstrated that its macromolecule contains regions of the linear alpha-1,4-D-galacturonan and branched apiogalacturonan. The side chains of apiogalacturonan were found to be formed of single and 1,5-linked residues of D-apiofuranose attached to 2- and 3-positions of the D-galacturonic acid residues of the apiogalacturonan backbone. Lemnan was shown to exhibit an immunomodulatory effect by activating the system of phagocytosis.
Adjuvants, Immunologic↗
Long-range signaling within growing neurites mediated by neurotrophin-3.
In addition to well established trophic functions, neurotrophins acutely affect neurotransmitter secretion from the presynaptic nerve terminal, influence synaptic development, and may serve as selective retrograde messengers that regulate synaptic efficacy. The crucial question related to the mechanisms of neurotrophin-mediated signaling is whether acute effects of neurotrophins are spatially restricted to the activated synapses. Here we have used a local perfusion technique for local delivery of neurotrophin-3 (NT-3) to various regions of developing Xenopus embryo neurons in culture. Within minutes after a focal exposure of a soma or a small ( approximately 30 micrometer in length) axonal segment to NT-3, we observed an increase in the spontaneous neurotransmitter secretion from the presynaptic nerve terminals located approximately 300-400 micrometer away from the site of NT-3 application. Secretory activity along the axonal shaft was not affected. Our findings suggest that the NT-3-mediated signal may rapidly travel through neuronal cytoplasm over unexpectedly long distances and modulate neurotransmitter release specifically at the presynaptic nerve terminals.
Acetylcholine↗
Neurotransmitter secretion along growing nerve processes: comparison with synaptic vesicle exocytosis.
In mature neurons, synaptic vesicles continuously recycle within the presynaptic nerve terminal. In developing axons which are free of contact with a postsynaptic target, constitutive membrane recycling is not localized to the nerve terminal; instead, plasma membrane components undergo cycles of exoendocytosis throughout the whole axonal surface (Matteoli et al., 1992; Kraszewski et al., 1995). Moreover, in growing Xenopus spinal cord neurons in culture, acetylcholine (ACh) is spontaneously secreted in the quantal fashion along the axonal shaft (Evers et al., 1989; Antonov et al., 1998). Here we demonstrate that in Xenopus neurons ACh secretion is mediated by vesicles which recycle locally within the axon. Similar to neurotransmitter release at the presynaptic nerve terminal, ACh secretion along the axon could be elicited by the action potential or by hypertonic solutions. We found that the parameters of neurotransmitter secretion at the nerve terminal and at the middle axon were strikingly similar. These results lead us to conclude that, as in the case of the presynaptic nerve terminal, synaptic vesicles involved in neurotransmitter release along the axon contain a complement of proteins for vesicle docking and Ca2+-dependent fusion. Taken together, our results support the idea that, in developing axons, the rudimentary machinery for quantal neurotransmitter secretion is distributed throughout the whole axonal surface. Maturation of this machinery in the process of synaptic development would improve the fidelity of synaptic transmission during high-frequency stimulation of the presynaptic cell.
ADP-Ribosylation Factors↗
Effects of polysaccharides from Silene vulgaris on phagocytes.
The effects of the polysaccharides isolated from the intact plant (pectic polysaccharides P1, P2 and P3) and from the callus (acidic arabinogalactan C1 and pectin C2) of Silene vulgaris on phagocytic activity were studied in relation to an uptaking capacity and a myeloperoxidase activity of the peripheral human neutrophils and monocytes and rat peritoneal macrophages in vitro. Both intact plant and callus polysaccharides were shown to increase uptaking capacity of peripheral phagocytes. The callus acidic arabinogalactan C1 was only found to stimulate lysosomal activity of the peripheral phagocytes. Some polysaccharides studied were established to effect on peritoneal resident macrophages. Pectins P1, P3 and C2 failed to enhance myeloperoxidase activity of the macrophages in calcium-free solution, whereas the effect of callus arabinogalactan C1 was established to be independent of extracellular calcium. Polysaccharides studied failed to influence neither complement receptor CR3- nor scavenger receptor SR-mediated adhesion of the macrophages. The data obtained demonstrate that the intact S. vulgaris and its callus may be used as sources of immunoactive polysaccharides and that pectins and weakly acidic arabinogalactan seemed to stimulate macrophages through different mechanisms. Complement receptor type 3 and scavenger receptor failed to mediate the cell activation induced by plant polysaccharides.
Adjuvants, Immunologic↗
Distribution of neurotransmitter secretion in growing axons.
Neurotransmitter secretion from the nerve terminal is mediated by the fusion of synaptic vesicles with the plasma membrane. It is generally believed that neurotransmitter release in mature synapses is localized to the presynaptic nerve terminals. To probe the topology of neurotransmitter secretion along developing axons in culture, we recorded membrane currents from myocytes manipulated into contact with axons. At the early stages of growth, exocytotic events were detected along the axon as well as at the growth cone. At the later stages of growth, neurotransmitter secretion adopted the form of a smooth proximodistal gradient, with the highest level of activity at the growth cone region. Our results reveal the existence of a previously undetected early stage of axonal growth and suggest developmental regulation in the pattern of neurotransmitter secretion along the growing nerve processes.
Acetylcholine↗