Publications by authors named "Shapovalova L"

The presented case report concerns a 62-year-old male patient who was admitted to the rheumatology department with a fever, shoulder and hip joint pain, significant limitation of movement in these joints and general weakness. Laboratory test revealed increase of inflammatory parameters, as ESR and C-reactive protein, rheumatoid factor and ACPA antibodies were absent. In the course of diagnostics, infections and cancer were excluded.

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The experiments on isolated nerve fibers from the frog Rana ridibunda have demonstrated that aminoacridine tacrin and aminocholine amiridine given in a concentration of 1 microM induced a 3-4 mV increase in the resting potential of the intact Ranvier nodal membrane depolarized by several millivolts by external source current, accompanied by a rise in the amplitude and curvature of action potential. With the voltage clamp, the two agents shifted a steady state potassium conductivity vs. the voltage curve measured in the vicinity of the resting potential in isotonic KCl solution.

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The effect of prospidin on Lewis lung carcinoma spreading under hyper- and hypocalcemia was studied. At early stages, increased extracellular calcium level was associated with inhibition of tumor dissemination to the lungs; however, later, colony growth was stimulated. Extracellular calcium level was shown to modulate the antitumor and antimetastatic effect of prospidin.

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A routine procedure for dissection of single nerve fibres with sharpened sewing needles is rather tiresome and occasionally traumatic because of poor efficiency in cutting interfibrous connective tissue and sticking out patches of it to preparative needles. The described method using microscalpel oscillating with ultrasonic frequency is free from these shortcomings. Voltage clamp tests proved an innocuous character of this method for excitable nodal membrane.

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The indolalkylamine alkaloid yohimbine induced two phenomenologically-different types of sodium current (INa) inhibition in the voltage-clamped frog node of Ranvier, a tonic and a phasic ('use-dependent') block. The latter developed during a repetitive membrane stimulation with short (5 ms) depolarizing pulses at frequencies at 1 to 10 Hz. Unlike repetitive pulsing, a single-long lasting (1 s) depolarizing step did not produce a phasic block.

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The effects of quinidine on sodium (INa) and potassium (IK) currents in the Ranvier node of frog myelinated nerve fibre was studied by means of voltage clamp technique. When applied externally quinidine (5.10(-5) M) suppresses both INa and IK.

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The indole alkaloid yohimbine (40 microM in the outside solution) is shown to reduce the intramembrane charge transferred by the asymmetric displacement current in the frog Ranvier node by 40%, the sodium permeability being inhibited by more than 90%. However, when tetrodotoxin (0.3 microM) was present in the outside solution, yohimbine inhibited the displacement charge only by a few per cent.

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Measurements were carried out by the method of double succrose gap. Accommodation was practically absent in all the preparations studied: the minimal gradient was not observed, the mean value of accommodation was 0.02 rheobasa/s, saturation current/H practically coincided with the current of rheobase IO(IH/IO = 1.

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Oxidative phosphorylation and optical density of the rat liver and kidney mitochondria were studied under the effect of UHF and SHF electromagnetic fields of different power and duration of the action. It is established that a single action of these fields induces changes in the functional state of the mitochondria. The action by the UHF and SHF fields of 30W for 10 min increases the activity of respiration and phosphorylation in the liver and kidney mitochondria.

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