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Biomedical subjects

S A Kozlov

Publications and source records attributed to S A Kozlov.

At least 19 recordsLinked to original sources
PubMed2002

[Pathogenetic validation of xidiphone use in combined therapy for periodontal diseases].

It is well grounded for the application of a preparation from group bisphosphonates xydiphone is justified (reasonable). For treatment and preventive maintenance of a tooth stone for want of periodontal inflammation. Is shown on 30 patients with acute parodontitis and at 10--with gingivitis (in a stage of a peaking), that the application of xydiphone will neutralize an alkaline response having a place up to treatment, due to what it(he) exhibits antiseptic of a property. Xydiphone, linking ionized Ca and free Fe, simultaneously hinders with activation of free--radical oxidation, reduces blood-flux and blocks process of crystallization.

Acute Disease↗
PubMed2001

An ERG channel inhibitor from the scorpion Buthus eupeus.

The isolation of the peptide inhibitor of M-type K(+) current, BeKm-1, from the venom of the Central Asian scorpion Buthus eupeus has been described previously (Fillipov A. K., Kozlov, S. A., Pluzhnikov, K. A., Grishin, E. V., and Brown, D. A. (1996) FEBS Lett. 384, 277-280). Here we report the cloning, expression, and selectivity of BeKm-1. A full-length cDNA of 365 nucleotides encoding the precursor of BeKm-1 was isolated using the rapid amplification of cDNA ends polymerase chain reaction technique from mRNA obtained from scorpion telsons. Sequence analysis of the cDNA revealed that the precursor contains a signal peptide of 21 amino acid residues. The mature toxin consists of 36 amino acid residues. BeKm-1 belongs to the family of scorpion venom potassium channel blockers and represents a new subgroup of these toxins. The recombinant BeKm-1 was produced as a Protein A fusion product in the periplasm of Escherichia coli. After cleavage and high performance liquid chromatography purification, recombinant BeKm-1 displayed the same properties as the native toxin. Three BeKm-1 mutants (R27K, F32K, and R27K/F32K) were generated, purified, and characterized. Recombinant wild-type BeKm-1 and the three mutants partly inhibited the native M-like current in NG108-15 at 100 nm. The effect of the recombinant BeKm-1 on different K(+) channels was also studied. BeKm-1 inhibited hERG1 channels with an IC(50) of 3.3 nm, but had no effect at 100 nm on hEAG, hSK1, rSK2, hIK, hBK, KCNQ1/KCNE1, KCNQ2/KCNQ3, KCNQ4 channels, and minimal effect on rELK1. Thus, BeKm-1 was shown to be a novel specific blocker of hERG1 potassium channels.

Amino Acid Sequence↗
PubMed1997

Three-dimensional structure of toxin OSK1 from Orthochirus scrobiculosus scorpion venom.

A 600 MHz 1H NMR study of toxin OSK1, blocker of small-conductance Ca2+-activated K+ channels, is presented. The unambiguous sequential assignment of all the protons of the toxin was obtained using TOCSY, DQF-COSY, and NOESY experiments at pH 3.0 (10, 30, and 45 degrees C) in aqueous solution. 3J(N alpha), 3J(alphabeta) vicinal spin coupling constants were determined in high-resolution spectra. The cross-peak volumes in NOESY spectra and the coupling constants were used to define the local structure of the protein by the program HABAS and to generate torsion angle and interproton distance constraints for the program DIANA. Hydrogen-deuterium exchange rates of amide protons showed possible locations of hydrogen bonds. The hydrogen bond acceptors and disulfide bridges between residues 8-28, 14-33, and 18-35 were determined when analyzing distance distribution in preliminary DIANA structures. All constraints were used to obtain a set of 30 structures by DIANA. The resulting rms deviations over 30 structures are 1.30 A for the heavy atoms and 0.42 A for the backbone heavy atoms. The structures were refined by constrained energy minimization using the SYBYL program. Their analysis indicated the existence of the alpha-helix (residues 10-21) slightly distorted at the Cys14 residue, two main strands of the antiparallel beta-sheet (24-29, 32-38), and the extended fragment (2-6). The motif is stabilized by the disulfide bridges in the way, common to all known scorpion toxins. Using the fine spatial toxin structure, alignment of the homologues, mutagenesis analysis, and comparison of scorpion toxin family functions, we delineate some differences significant for the toxin specificity.

Amino Acid Sequence↗
PubMed1997

[Adaptation to hypoxia as a factor enhancing work capacity].

The results of applying N. N. Sirotinin's concept of the use of hypoxic adaptation to enhance working capacity are given. There is evidence for the efficiency of adaptation of trotters to two hypoxias: to hypoxic hypoxia (in the midmountains) and to exercise hypoxia (during interval training under the conditions of Moscow) for increasing their performance. These studies demonstrated that in the midmountains, the trotters had more infrequent respiration, increased respiratory and minute respiratory volumes which were more obvious by the end of a monthly mountain stay. The monthly training of trotters significantly altered hemoglobin levels and erythrocyte counts. Correction of the respiratory system via adaptation to decreased p1O2 improved good time in trotters: the speed increased by 0.41 versus by 0.18 m/sec in the controls. The average record of experimental horses significantly increased and was equal to 2 min 09.7 sec for a 1600-m distance while the control horses had 2 min 11.1 sec. The use of interval exercises during training produced positive changes in the systems of expiratory respiration, blood flow, blood, tissue metabolism. Blood oxygen transport function improved in trotters after interval training. This training markedly improves the fast qualities in trotters.

Adaptation, Physiological↗
PubMed1996

M-type K+ current inhibition by a toxin fron the scorpion Buthus eupeus.

A number of invertebrate venoms have been tested for effects on M-type K+ currents (IK(M)) in differentiated mouse neuroblastoma X rat glioma NG108-15 cells. Among the venoms tested, Buthus eupeus scorpion venom reversibly inhibited IK(M) by approximately 44% at 50 microgram/ml. Inhibition was not due to activation of bradykinin or nucleotide (pyrimidine) receptors. On venom fractionation, a polypeptide of 4 kDa was purified that inhibited IK(M) by approximately 45% with an IC50 of approximately 33 nM. Neither the crude venom nor the purified polypeptide affected the Ca2+ current or the delayed rectifier K+ current. While the crude venom prolonged the Na+ current, the polypeptide did not. Thus, the 4 kDa Buthus eupeus polypeptide appears to be a selective inhibitor of IK(M) in NG108-15 cells.

Animals↗
PubMed1991

[Angioneurotic edema of the face and upper extremities].

A classification scheme in which the etiology, localization, course and intensity of edemas are reflected has been elaborated on the basis of examining 255 patients with neurovascular edemas of the face and upper limbs. The authors provide a list of the main diagnostic methods, which enables the mechanisms of the development of neurovascular edemas to be specified.

Angioedema↗
PubMed1991

[The use of xidifon in the vertebral artery syndrome during exacerbation].

To remove painful attacks in patients with the vertebral artery syndrome, use was made of xidiphon. The two methods of its administration were developed: application and electrophoretic. 27 patients in the stage of the disease exacerbation were examined and then treated. Vertebrobasilar vessels were examined over time by REG. A study was made of the content of macroelements and trace elements in the area of the impaired vessel, of the status of the bulbar conjunctival vessels using a "ShchL-2" lamp, and of the changes in the psychovolitional sphere and lipid peroxidation. A positive analgesic effect was attained in 25 patients, making it possible to eliminate or diminish to a considerable measure the doses of analgesics.

Acute Disease↗
PubMed1991

[An epidemiological assessment of the chronic carriage of the hepatitis B virus surface antigen and other markers of this infection].

On the basis of prolonged (up to 10 years) observations of chronic HBsAg carriers (87 persons) slowly progressing chronic hepatitis B virus infection was detected in most of them (57.5%). In these persons up to 6 negative results of the analysis for the presence of HBsAg were periodically obtained, with the subsequent renewal of HBs-antigenemia. More profound examination of 192 persons with chronic lesions of the liver and other digestive organs helped diagnose chronic persistent hepatitis and chronic active hepatitis, accompanied by HBs-antigenemia and the circulation of other markers of this infection, in 63.5% of the examinees.

Adult↗
PubMed1990

[Effect of fasting and elemental carbohydrate feeding on the liver resistance to the action of cytostatics].

To study the influence of cyclophosphamide and methotrexate on the function of isolated perfused liver, and the hepatoprotective effect of starvation and parenteral glucose feeding, the authors conducted 57 tests on the rabbit liver. It was established that addition of cyclophosphamide, and, especially, of methotrexate into the perfusate negatively affected the function of the isolated perfused liver. Parenteral glucose feeding produced a protective effect on the isolated liver against the detrimental action of both methotrexate and cyclophosphamide.

Animals↗
PubMed1990

[Treatment of patients with trigeminal neuralgia by xidifon electrophoresis].

Fifty-two patients with trigeminal neuralgia were treated by electrophoresis with a 2% solution of ksidifon. 23 patients demonstrated a remarkable analgetic effect in the form of disappearance of painful paroxysms and activity of the trigger zones, which enabled a considerable reduction of the daily dose of carbamazepine (finlepsin). In 14 patients, the rate and severity of algic attacks noticeably decreased without the lowering of the finlepsin dosage. Therefore, the suggested method of the treatment of trigeminal neuralgia, being simple in use, effectively removes the painful syndrome, contributing to a noticeable reduction of the doses of the toxic drugs of the carbamazepine type.

Analgesics↗
PubMed1990

[Perfusion protection of ischemic liver using perfluorocarbon emulsion].

Several concentrations of Fluorocarbon emulsion as means for anti-ischemic protection of the liver were studied in experiments on 47 rabbits with hypothermic perfusion of isolated liver exposed to 90 minute ischaemia. the best concentration of Fluorocarbon emulsion for perfusion of isolated liver was 12%.

Animals↗
PubMed1989

[Anti-ischemic protection of the liver using perfluorocarbon emulsion].

Anti-ischemic effectiveness of a Soviet perfluorocarbon emulsion (PFE) was studied in 43 experiments on rabbits with 90-min constriction of the hepatoduodenal ligament and under hypothermic perfusion of the liver during ischemia in the open contour. It has been established that PFE perfusion to a great extent promotes the retention of the ischemized liver function.

Animals↗
PubMed1988

[Monthly dynamics of the epidemic process in viral hepatitis B].

Monthly fluctuations in the number of registered cases of acute viral hepatitis B and HBsAg carriership have been studied. The study has revealed that, similarly to other infectious diseases, viral hepatitis is characterized by monthly fluctuations in the intensity of the epidemic process. Such fluctuations are characteristic of all known clinical forms of this infection; they are determined by the specific pathogenetic features of the process and by the ways of the transfer of the virus. The vernal rise of the infection is explained by activation of the manifest and asymptomatic chronic variants of the infectious process and, as the consequence of a rise in the number of asymptomatic cases, by a higher incidence rate of post-transfusion hepatitis infection. The autumnal rise of the infection results from the action of natural factors contributing to the transfer of the virus. Both rises are interrelated and interdependent. The seasonal fluctuations of the epidemic process should be taken into consideration when planning and implementing prophylactic and epidemic-control measures.

Carrier State↗
PubMed1987

[Effect of elemental nutrition and fasting on the resistance of the liver to ischemia].

The efficiency of the element nutrition with glucose and alvezin and fasting as means of the antiischemic defense was studied in 50 experiments in perfusion of the isolated liver on rabbits previously subjected to 18-20 minute heat ischemia. The parenteral administration of glucose and graded fasting were shown to be most effective for the antiischemic defense of the liver.

Amino Acids↗