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Biomedical subjects

S M Kuznetsova

Publications and source records attributed to S M Kuznetsova.

At least 19 recordsLinked to original sources
PubMed1992

Calorimetric study of interactions of toxin from Radianthus macrodactylus with erythrocyte membrane.

Differential scanning microcalorimetry, intrinsic protein fluorescence and SDS-electrophoresis have been applied for the study of the hemolytic toxin from sea anemone, Radianthus macrodactylus, when it is incorporated into pure sphingomyelin/water systems and upon its effect on the human and dog erythrocyte membranes. The results obtained by using these techniques showed that one molecule of toxin withdraws six sphingomyelin molecules from the cooperative transition. Effect of hemolytic toxin on human erythrocyte ghosts causes an appearance of a new heat sorption peak in their differential scanning calorimetric curve with a maximum of 36 degrees C and, moreover, it leads to a loss of one of cytoskeleton proteins (actin). These effects are essentially weaker in the case of dog erythrocyte ghosts. This suggests differences in the structural organization of human and dog erythrocyte membranes.

Animals↗
PubMed1990

[Ethnic characteristics of age-related changes in the development of electric activity of the brain during aging].

Clinico-electrophysiological examinations of the indigenous population of Azerbaijan and of Russians who had moved to the indicated region over 150 years before made it possible to define the ethnic traits of the ageing of the central nervous system. Overall 495 persons were examined. In Russians, the age-associated alterations in brain bioelectrical activity were found to set in 15 to 25 years earlier than in Azerbaijanians.

Action Potentials↗
PubMed1990

[Synergism in the action of gamma radiation and cardiac glycosides].

Synergism of gamma radiation with 137Cs and cardiac glycosides was investigated in experiments on mice and transplantable Raji tumor cells. A single ip administration of these drugs at nontoxic concentrations 30-60 min. after irradiation at the LD30/30 resulted in the survival of 13-20% of animals and the reduction of the mean survival time up to 8.4-12.5 days versus 22.3 days in the control group. Synergism was slightly decreased at administration of glycosides 24 h after irradiation. Glycosides introduced in the irradiated (at a dose of 1-2.5 Gy) human lymphoblastic line caused sharp suppression of lymphoma growth and cellular lysis in experiments in vitro. One hundred per cent death of cells was noted after the use of the drugs at mean toxic concentrations.

Animals↗
PubMed1990

[Age-related features of the functional state of the brain in patients with circulatory encephalopathy].

Complex clinico-physiological examinations was performed in 300 patients of middle and old ages with early and pronounced dyscirculatory encephalopathy of atherosclerotic and, in most cases, hypertensive etiologies. The cerebral hemodynamics was found to be relatively independent of the central one in patients with early atherosclerotic encephalopathy; the level of the systemic circulation and that of the median regional cerebral flow were found to correlate in early and advanced hypertensive encephalopathy cases. The cerebral function was shown to be more associated with the cerebral flow in the early encephalopathy in elderly patients than in middle-aged ones. The individual and personal traits of the patients were largely related to the disease stage rather than to the predominant etiological factor.

Adult↗
PubMed1990

[Amikacin in the treatment of infectious-inflammatory diseases in patients at a therapeutic hospital].

Amikacin sensitivity of 157 strains which caused infectious inflammatory diseases in patients of a therapeutic hospital was studied. It was shown that 52 and 42.9% of the isolates from patients with bronchopulmonary infections were highly and moderately sensitive to amikacin, respectively. 5 pneumococcal strains were resistant to amikacin. Among the isolates from urine of the patients with urinary infections there were no strains resistant to amikacin. Study of amikacin pharmacokinetics demonstrated expediency of antibiotic endobronchial administration to patients with bronchopulmonary diseases and aggravation of chronic purulent inflammatory processes. A favourable clinical effect of amikacin after its intramuscular or endobronchial administration was observed in 53.3% of the patients. In 30% of the patients the effect was satisfactory. In 16.7% of the patients the treatment failed. Satisfactory antibiotic tolerance in the majority of the patients was stated.

Amikacin↗
PubMed1989

A dynamic model for in-vitro evaluation of antimicrobial action by simulation of the pharmacokinetic profiles of antibiotics.

The general principles of in-vitro simulation of drug pharmacokinetic profiles for linear one-, two- and multi-compartment models are described. An in-vitro dynamic model constructed on the basis of these, incorporating a novel filtration unit to provide efficient filtration of drugs at constant inoculum size, was used to study the antimicrobial action of sisomicin on Escherichia coli A 20363, in conditions simulating the pharmacokinetic profile observed in humans after a single intramuscular dose of 1 mg/kg.

Anti-Bacterial Agents↗
PubMed1987

Polymorphism of heterochromatin areas on chromosomes 1, 9, 16 and Y in long-lived subjects and persons of different ages in two regions of the Soviet Union.

Variants of chromosome polymorphism were analyzed in long-lived individuals and in subjects aged 40-79 years (170 persons) in two regions of the Soviet Union. The results of this analysis allow the suggestion that there is an association between the individual variants of chromosome polymorphism as regards C heterochromatin and the longevity phenomenon. Large size C segments on the human Y chromosome and the long Y chromosome were found both in the Ukrainian and Abkhasian long-lived males. In the long-lived females the chromosome polymorphism variants were associated with a region of their residence. The long-lived females of Abkhasia had a decreased relative size of C segments on chromosome 1 and an increased absolute and relative size of C segments on chromosome 9, while in their Ukrainian counterparts there was an increased relative size of C segments on chromosome 1 and a decreased one on chromosome 16.

Adult↗
PubMed1987

[Detection of constitutional types of EEG using the orthogonal decomposition method].

The authors present an algorithm of investigation into the processes of brain bioelectrical activity with the help of an orthogonal decomposition device intended for the identification of constitutional types of EEGs. The method has helped to effectively solve the task of the diagnosis of constitutional types of EEGs, which are determined by a variable degree of hereditary predisposition for longevity or cerebral stroke.

Adult↗
PubMed1985

[A dynamic system for the in vitro study of the kinetics of the antimicrobial effect of antibiotics in pharmacokinetic changes in their concentration].

The present approaches to in vitro investigation of the kinetics of the antibiotic antimicrobial effect are based on its recording at one or another constant concentration of the drugs. The regularities revealed under such conditions do not usually reflect the peculiar effect of the drugs in vivo, since with the use of the routine schemes of dosing the drug levels in the body fluids always vary. For investigation of the kinetics of the antimicrobial effect of antibiotics at their varying levels, a universal dynamic system providing in vitro simulation of the pharmacokinetic profiles of the drugs in blood and tissues was developed. The system is based on the controlled dilution of the medium containing an antibiotic and microbial cells. the dynamic system allows simulation of any kinetic profile of the drugs with regard to the constants of the linear pharmacokinetic N-compartmental model. The trial of the dynamic system as applied to the antimicrobial effect of sisomicin on strain A 20 363 of E. coli revealed significant differences in the effect of the drug, when its bioexponential pharmacokinetic profile was simulated in a one-compartmental model with exponential absorption and a constant concentration of the antibiotic. The check determinations of the antibiotic concentration in the main flask of the system showed that the system provided high accuracy simulation of the required antibiotic levels.

Dose-Response Relationship, Drug↗
PubMed1985

[Methods of evaluating the efficacy of combinations of aminoglycosides with penicillins and their value for the possibility of predicting the therapeutic effect in patients].

The efficacy of the combinations of aminoglycosides and penicillin with respect to Pseudomonas, Klebsiella and Escherichia strains was estimated with the methods of two-fold serial dilutions of aminoglycosides and constant concentrations of penicillin and the "chess board" method. Correlation between the synergistic effect and sensitivity of the strains to separate components of the combinations was observed. For prediction of the combination efficacy these methods are not useful, since they are labour-intensive and their results are very variable. In this connection a simple informative test is recommended. With the use of this test it is possible to judge the chemotherapeutic efficacy of antibiotics and their combinations by the value of the serum antibacterial activity (titer) against the infection causative agent. The blood serum titer of at least 1:8 is accompanied by a pronounced effect. The test also indirectly provides information on the sensitivity of isolated pathogens and adequacy of the drug blood levels after administration of the chosen dose.

Animals↗
PubMed1985

[Characteristics of the composition of the causative agents of different forms of suppurative inflammatory diseases and their antibiotic sensitivity].

Antibiotic sensitivity of 466 clinical strains of gram-positive and gram-negative microorganisms isolated from patients with different forms of pyoinflammatory diseases was studied. Most of the staphylococcal isolates were resistant to benzylpenicillin (74.3 per cent). The number of the isolates resistant to erythromycin amounted to 59.6 per cent. The respective figures for methicillin and dicloxacillin were 17.9 and 10.8 per cent. Staphylococci resistant to new aminoglycosides, fusidin and rifampicin were rare. It was shown that. P. aeruginosa preserved its sensitivity to the majority of the antipseudomonas antibiotics. Among Enterobacteriaceae the highest levels of antibiotic resistance were observed in Enterobacter, Citrobacter, Serratia and Klebsiella. Significant variation in the isolation frequency of different microbial species and in the proportion of gram-negative and gram-positive bacteria in the hospital departments was observed. It was noted that gram-negative causative agents predominated in the departments of chest and abdominal surgery, anesthesiology, intensive care and urology.

Anti-Bacterial Agents↗
PubMed1985

[Experimental study of the antibacterial activity and chemotherapeutic effectiveness of amikacin sulfate].

In vitro antibacterial activity of amikacin against 250 strains of various microorganisms was studied. It was shown that the antibiotic had a broad antibacterial spectrum and was active against gentamicin and sisomicin resistant strains of Enterobacteriaceae and Pseudomonas. By the antibacterial spectrum amikacin was close to kanamycin. Still it differed from kanamycin by activity against P. aeruginosa. By the specific activity gentamicin and sisomicin were superior to amikacin. However, since amikacin was active against gentamicin resistant strains of various microorganisms it was considered advisable to use it as a reserve antibiotic in treatment of infections caused by such strains. High in vivo efficacy of amikacin was shown in experimental sepsis of albino mice due to staphylococci and gramnegative bacteria sensitive to the aminoglycosides and P. aeruginosa strains resistant to gentamicin and sisomicin.

Amikacin↗