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Biomedical subjects

V I Kuznetsov

Publications and source records attributed to V I Kuznetsov.

88 records · Page 5Linked to original sources
PubMedDate not supplied

[Adaptive capabilities of the "hypokinetic" heart of the rat to a resistance load and the role of nervous regulation].

Adaptation of the heart of hypokinetic rats to sustained afterload and the role of nervous regulation in this process were investigated. The experimental rats were subdivided into four groups: 1) control, 2) hypokinesia for 64 days, 3) coarctation of aorta for 4 days, and 4) hypokinesia for 60 days plus coarctation of aorta for 4 days. It was found that the rates of contraction and relaxation of the heart increased by 22 = 51% in the Group 2 rats and decreased by 32 = 40% in the Group 3 rats as compared to the controls. Coarctation of aorta that followed 60-day hypokinesia (Group 4) reduced the increased parameters to the control level. After heart denervation (vagotomy and drug desympathization) all the rats showed depression of the contractile parameters to a varying degree: Group 2 rats exhibited the lowest degree of depression. It can be concluded that cardiac resistance of the hypokinetic rats to afterload is higher than in the intact rats with coarctation of aorta; on the other hand, afterload reduces the hypokinesia-induced increase in the contractility function, making it close to the control level. In addition to the nervous influences (sympathetic), intracardiac factors play an important role in the mechanisms of adaptation of the heart to hypokinesia and of the hypokinetic heart to afterload.

Adaptation, Physiological↗
PubMedDate not supplied

[Binding of gamma-aminobutyric acid in the synaptic membranes of rat brain].

The Na+-dependent and Na+-independent (receptor) binding of [3H] GABA is measured in rat brain synaptic membranes. The receptor binding is presented by at least 3 types of binding sites differing in kinetic parameters (dissociation constants and maximal concentration of binding sites). Phenyl-GABA and pyracetam do not affect receptor binding while 4-hydroxybutyric acid, apamine and bicuculline inhibit it with inhibition constants K1=100, 2 and 1 micron, respectively. Solubilization of synaptic membranes with 2% potassium cholate in the presence of total brain phospholipids does not inactivate [3H] GABA receptor binding.

Animals↗
PubMedDate not supplied

[Distribution of thromboplastic and 5'-nucleotidase activity in human liver].

Isopycnic centrifugation of human liver tissue was carried out in sucrose density gradient. Thromboplastic activity, accompanied by 5'-nucleotidase, was mainly localized in plasmatic membranes of liver cells. The biochemical analyses of human liver tissue may be performed within 24 hrs after death.

5'-Nucleotidase↗
PubMedDate not supplied

[Effect of ultra-high frequency electromagnetic waves on a postsynaptic membrane model].

It was shown that high-frequency electromagnetic field increases the conductivity of ionic channels formed by the synaptic membrane fragments, which bind glutamate, in a bilayer lipid membrane. Heating of the whole electrolyte in a cell, under the effect of the electromagnetic field applied, was minor to be responsible for the effects observed.

Glutamates↗
PubMedDate not supplied

[Evaluation of myocardial contractile function based on seismocardiographic data of rats in hypokinesia].

The possibility of seismocardiographic recording in rats has been explored and SCG time and amplitude parameters have been determined. The measurements have been performed in normal rats and hypokinetic rats with an altered cardiac contractility. The SCG data obtained in hypokinetic rats have been compared with the results derived from contractility studies by heart catheterization and subsequent calculation of contraction strength and velocity. It has been shown that the data compared are similar on hypokinetic days 1 and 5. This suggests that the seismocardiographic method of studying heart contractility function of rats is adequate for integral evaluations of the strength and velocity of cardiac contractions in chronic experiments. On hypokinetic days 15 and 30 the data obtained by catheterization and seismocardiographically are at variance. This may be attributed to muscle mass losses and variations in the rigidity of "internal" bonding.

Animals↗
PubMedDate not supplied

[Experience in organizing the manufacture of medical equipment at large-scale enterprises].

The Izhevsk Motoplant is one of the largest Russian industrial associations which has successfully mastered and at present serially produces medical articles, including those for examination of the cardiovascular system (EK1T-03M2 and EK1TTsSP-01 electrocardiographs, etc.), apparatuses for maternal and child care (a DLTB -01 set for the diagnosis and treatment of tubal infertility; a complex for resuscitation of the newborn); route emergency and resuscitation cars. The Izhevsk Motoplant actively cooperates with the country's leading designing Research Institute of Medical Instrument Making, Russian Academy of Medical Sciences.

Adult↗
PubMedDate not supplied

[Medical technology: the leading trend in the conversion of an enterprise].

The Izhevsky motozavod (Aksion Public stock company) is one of the Russia's largest production associations (PA), which manufactures a wide range of products for various purposes, including those for implementation of space programmes. Medical engineering is close to space instrument making as it required special technologies, high quality and reliability for its manufacture. The development and introduction of medical equipment into production of the Izhevsky motozavod PA are under way along several basic lines: electrocardiographic equipment and defibrillators, devices for maternity and child care, ambulances, reanimobiles, etc. The most interesting produce, such as one-channel EK1 TTSSP-01 (for emergency care) and EK1T-04 electrocardiographs, DKI-H-04 defibrillator, Oksipuls-01 pulsoximeter, a DLTB-01 unit for diagnosis and treatment of tubal sterility in females, a KPH-01 unit for neonatal resuscitation, an ambulance, a Nadezhda reanimobile, etc. are briefly described.

Adult↗
PubMedDate not supplied

[Reaction of the brain receptor system to the effect of low intensity microwaves].

We have found that two important brain synaptic receptor systems are very sensitive to the influence of low intensity microwaves. Both the excitatory glutamatergic and the inhibitory GABAergic are affected by microwave exposure. Power densities higher 50 microW/cm2 caused changes in the binding properties of these receptors to agonists. Low frequence modulation of microwaves was essential for these effects. Statistically significant effects on mean value of binding were observed at 16 Hz modulation. Exposure to microwave radiation changes the binding of agonists to glutamate and GABA receptors in different ways. An increase was observed for glutamate and a decrease for GABA. We suppose that the effect of microwaves is related to the stress reactions of the organism.

Animals↗