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Biomedical subjects

Iu D Ignatov

Publications and source records attributed to Iu D Ignatov.

At least 19 recordsLinked to original sources
PubMed2004

[Response of the spinal trigeminal nucleus neurons to electric stimulation of the rat dura mater].

Aseptic inflammation of tissues surrounding large meningeal blood vessels, e.g. the superior sagittal sinus, underlies pathogenesis of migraine. This inflammation develops due to antidromic activation of sensory trigeminal nerve endings and is followed by changes in responses of the spinal nucleus of the trigeminal nerve neurons to electrical stimulation of the superior sagittal sinus. However, characteristics of these reactions are still unclear. In experiments ou urethane-anesthetized rats, responses of 387 neurons of the spinal nucleus of the trigeminal nerve to electrical stimulation of the superior sagittal sinus, were recorded. It was tial discharge with the latency 7 to 19 ms (11.4 +/- 0.17 ms) and a subsequent long-lasting discharge with the latency 20 to 50 ms (34.2 +/- 0.8 ms). It is presumed that the first phase reflects orthodromic activation of prevascular A delta and C-fibers of the trigeminal nerve while the second phase is connected with activation of meningeal C-fibers which have low conduction velocity, and/or with a secondary activation of perivascular sensory endings of trigeminal nerve by releasing algogenic and vasoactive substances. These changes could be used as an indicator of efficacy of some antimigraine substances in animal experiments.

Animals↗
PubMed2004

[On teaching surgery at the graduation course of a medical college according to a new curriculum].

Teaching surgery to students of the medical college represents a complex dynamic process based on the achievements and advantages of domestic medical education. The article presents an analysis of historical aspects of teaching surgery formed under the influence of N.I.Pirogov's ideas and shows the necessity of searching for new forms of organization of teaching surgery at the up-to-date stage of reorganization of higher professional school. Special attention is given to a compulsory preservation of traditional principles of the system of teaching surgery verified by almost two centuries of experience of using it.

Academic Medical Centers↗
PubMed2004

[Influence of He-Ne laser irradiation and local anesthetics on potassium channels in the snail neurons].

Using clamp method it had been shown that He-Ne laser irradiation of the snail neurons increases the amplitude of voltage-gated slow potassium currents in dose of 0.7 x 10(-4) (fluence 1.5 x 10(2) Wt/m2) and decreases it in dose 0.7 x 10(-3). Bupivacaine and lidocaine suppressed potassium currents. Laser irradiation in dose 0.7 x 10(-3) enhanced the inhibitory effect of bupivacaine (10 mcM) and in dose 0.7 x 10(-4) it decreased the inhibitory effect of bupivacaine. The results of the study suggest mechanisms of the He-Ne laser irradiation effect in combination with pharmacological substances on ion channels of electrically excitable cells.

Anesthetics, Local↗
PubMed2003

[Current views on migraine and anti-migraine preparations].

On the basis of comprehensive experimental and clinical research the authors defined a variety of migraine-related mechanisms and schemes of migraine-correction by drugs, which should be both of the vascular- and general-actions to ensure an effective medication.

Adrenergic Uptake Inhibitors↗
PubMed1998

[Left and right brain hemispheres in the regulation of pain sensitivity biorhythms in mice during stress].

The foot-shock effects on ultradian and circadian rhythms of pain sensitivity in the SHR mice were studied after unilateral brain cortex hemisphere inactivation by means of the Leao spreading depression. Under acute painful stress, the left hemisphere partially loses its synchronizing effect on circadian rhythm and supports the 12-hour and particularly 6-hour periodicities. The left hemisphere effect dominates in intact animals under stress. The right hemisphere under the same conditions mainly loses its activating effect on circadian rhythm and supports the 8- and 16-hour periodicities. The right hemisphere effect dominates in animals under stress operated 2-3 days prior to the experiment.

Activity Cycles↗
PubMed1998

[Adrenergic mechanisms of pain regulation].

The authors briefly account the opioidergic regulation of pain and postulate a concept of adrenergic pain-relieving systems. They also analyze the analgetic and vegetocorrecting effects of clofelin and its benefits as a centrally acting non-opiate analgetic. They discuss the status and prospects for optimization of non-opiate anesthesia in clinical practice.

Adrenergic Agents↗
PubMed1998

[A comparative evaluation of the chronobiological organization of the pain-relieving action of analgesics].

The spectral analysis of over 50-hour series of observations (tail flick) has revealed two ultradian periodicities of rat pain sensitivity with 8- and 12-hour duration and the circadian one. The minimum sensitivity was observed in the first half of the light phase. Morphine (5 mg/kg i.p.) did not change the spectrum of rhythms, but inverted the phase of a circadian constituent--it was most effective in the middle of the dark phase. Naloxone (1 mg/kg) significantly changed the spectrum of ultradian rhythms, but did not alter the length and phase of circadian periodicity. After moradol (1 mg/kg) administration it could decrease and alter the spectrum of periodicities with the most prominent infradian rhythm. On the contrary, metamizole (50 mg/kg) injections did not interfere the rhythmic pattern of pain sensitivity. Thus, narcotic analgesics have specific effects on the chronological organization of pain sensitivity rather than non-narcotic ones do.

Analgesics, Non-Narcotic↗
PubMed1992

[Changes in pain sensitivity under increased atmospheric pressure].

It has been established that augmentation of air pressure from 0.1 to 1.1 MPa (with 0.1 MPa intervals) was accompanied in rats with the development of progressive analgesia which was measured according to the threshold of vocalization in the test of electrical stimulation of the tail. The highest analgesic response arose at 0.7-1.1 MPa. All the animals might be divided into two groups: group 1-72% of the animals with a 200% increase of the threshold, group 2--animals with such an increase by 15%. The augmentation of the pressure of heliox (79.1% of helium, 20.9% of oxygen) also caused analgesia, but not so strong. In patients pain thresholds to the mechanical nociceptive stimulation also increased by about 43-67% and 95-100% under the influence of increased air pressure of 0.4 and 0.7 MPa, respectively. In group 1 patients (67%) pain threshold increased by 50-100%, in group 2 by 15-25%. Pretreatment with naloxone (1 mg/kg), atropine (1 mg/kg), yohimbine (1 mg/kg), parachloramphetamine (5 mg/kg) and prasosin (1 mg/kg) decreased hyperbaric analgesia in rats by 41-56, 41-56, 17-19, 17-19%, respectively. The role of increased partial pressure of nitrogen in hyperbaric analgesia and possible neurochemical mechanisms of its realization are discussed.

Adult↗
PubMed1991

[Neurophysiological mechanisms of the antihypertensive effect of clopheline in pain].

In experiments on conscious and unanesthetized cats it was shown that clopheline in analgesic doses do not change the pain baroreflex blood pressure regulation and mild brain antinociceptive sympathoactivating influences. The clopheline antihypertensive effect was due to nonopiate direct sympathoinhibitory effect realized by suprasegmental level of vasomotor regulation.

Animals↗
PubMed1989

[The use of clofelin in the acute period of myocardial infarct].

Data are reported on the action of intravenous clophelin in 30 patients administered within the first 24 hours of myocardial infarction. The agent exhibited a significant analgetic effect, sedative action and normalized the main hemodynamic values. The effect of clophelin on the hemodynamics depended on its initial state. The possibility is shown to predict the pain-killing and hemodynamic effects of the drug by the initial response.

Aged↗
PubMed1988

[Role of opioid and adrenergic mechanisms in the analgesic action of GABA-positive drugs].

The experiments on rats have shown that repeated administration of depakin and baclofen induced the development of tolerance to their antinociceptive effect. The animals tolerant to depakin and baclofen were supersensitive to the analgetic effect of morphine and clonidine in tail-flick test. In vocalization test the analgetic effect of clonidine in baclofen- and depakin-tolerant animals was not altered. The antinociceptive effect of morphine under these conditions was reduced significantly in depakin-tolerant rats and was unchanged in baclofen-tolerant animals. The role of opioid and adrenergic mechanisms in GABA-ergic analgesia and in the development of tolerance is discussed.

4-Aminobutyrate Transaminase↗