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Biomedical subjects

A V Bogdanov

Publications and source records attributed to A V Bogdanov.

At least 19 recordsLinked to original sources
PubMed2006

Correlated activity of sensorimotor cortex neurons in the left and right hemispheres of the rabbit brain in immobilization catatonia.

Spike sequences extracted from multineuron activity from neurons in the sensorimotor cortex, and recorded simultaneously in the left and right hemispheres of the brains of rabbits in the state of immobilization catatonia ("animal hypnosis") and on recovery of animals from this state were analyzed. Cross-correlation analysis of spike flows revealed a temporal relationship between the appearance of neuron spikes in the left and right hemispheres; these were regarded as the mutual influences of these neurons on each other. The intensity of the influences of left hemisphere neurons on cells in the right brain was shown to change significantly in relation to baseline measures at all stages of the experiment and at all of the time points studied. The intensity of the influences of neurons in the right hemisphere on cells in the left hemisphere changed significantly only after animals recovered from the state of immobilization and over much more restricted time periods.

Action Potentials↗
PubMed2004

Structure of dependent relationships between neurons in the sensorimotor cortex of the left and right hemispheres in rabbits in immobilization catatonia.

Dependence in the activity of sensorimotor cortex neurons recorded simultaneously in the left and right hemispheres was detected in rabbits in baseline conditions, during the state of immobilization ("animal hypnosis"), and recovery of animals from this state. In baseline conditions, the total percentage of dependent relationships between close-lying (within 50 microm) neurons in the left hemisphere was significantly smaller than in the right hemisphere and did not change either in the state of immobilization or on recovery from it. The total percentage of dependent relationships between close-lying neurons in the right hemisphere decreased significantly during immobilization and returned to baseline levels on recovery from this state. The percentage of dependent relationships between distant (500 microm) neurons in immobilization, conversely, showed no change in the cortex of the right hemisphere, though it changed significantly in the cortex of the left hemisphere, returning to baseline values when the rabbits recovered from this state. Further analysis showed that this cortical interhemisphere asymmetry was based on the asymmetrical activity of individual neurons and small neuronal populations. Thus, changes in the structure of dependent relationships between neurons in microareas of the cortex of the left and macroareas of the cortex of the right hemisphere could be in different directions, while changes in microareas of the right hemisphere and macroareas of the left hemisphere were synergistic. Thus, asymmetry was detected at different levels of neuronal combinations (neuron pairs, micro- and macrogroups of neurons), which suggests mosaicism in neuron structure, which ultimately leads to overall functional asymmetry in "animal hypnosis." Some changes in the structure of dependent relationships between sensorimotor cortex neurons arising in "animal hypnosis" persisted or even became more marked after recovery of animals from this state.

Action Potentials↗
PubMed2004

[Use of immunoglobulin E and pregnancy-specific beta-1-glycoprotein in differential diagnosis of bone malignancies].

Such factors as high levels of immunoglobulin E and pregnancy-specific 1-glycoprotein (PSG) appear as diagnostic criteria for both bone malignancies and acute hematogenous osteomyelitis. It was found that significant increase in blood-serum PSG in conjunction with lowered IgE is a marker of bone malignancy while decreased PSG and high IgE is that of acute hematogenous osteomyelitis.

Adolescent↗
PubMed2004

[Undeveloped high intestinal fistulas as an urgent problem of modern surgery].

Eighty-two cases of un formed high intestinal fistulas are analyzed. Degree of non-formation and volume of chymus loss are the main criteria determining treatment policy. Early surgery (one or two-sided switching of fistulas zone) is indicated in intestinal loss more then 600-700 ml per day or in complete fistula. Mezonnes surgery was un effective in the majority of cases. Special policy including trunk vagotomy, antrumectomy and plastic repair of the duodenal bulb permitted in the last years to avoid duodenal fistulas in the treatment of ulcer disease.

Adolescent↗
PubMed2003

Comparative analysis of the frequency of neuron spike activity in the sensorimotor cortex of the right and left hemispheres in conditions of immobilization catatonia in rabbits.

Multineuron activity was recorded from the sensorimotor cortex of the right and left hemispheres during immobilization catatonia in rabbits. The first session of immobilization of the animals was followed by changes in spike frequency in 47% of neurons in the sensorimotor cortex of the right hemisphere. Of these, 30% showed decreases in spike frequency and 17% showed increases. Spike frequency in the sensorimotor cortex of the left hemisphere changed in only 18% of cells, of which 13% showed decreases in spike frequency and 5% showed increases. The spike frequency of neighboring (recorded with the same electrode) neurons could change reciprocally. Differences in neuron activity in the two hemispheres were virtually absent after the second session of immobilization (several days after the first)--spike activity changed in 21% of neurons in the right hemisphere and 24% in the left hemisphere. The ratios of the numbers of neurons with increases and decreases in spike activity in "hypnosis" also became identical in the cortex of the right and left hemispheres. A hypothesis is proposed for the involvement of cortical neurons in the organization of "hypnosis-like" states.

Action Potentials↗
PubMed1991

[Dynamics of functional interconnections between cerebral motor cortex neurons of cats under stimulation].

In acute experiments on cats the activity of the motor cortex neurons was recorded. The dynamics of interneuronal connections at passive bending and electrostimulation of the limb contralateral to the place of recording was studied by methods of cross-correlation analysis of impulse trains. At passive bending a considerable decrease of the number of common inputs between neighbouring neurons (within 50-100 microns) and an increase in their number between remote (from 100 till 400 microns) cortical neurons. During electro-stimulation a certain increase in the number of direct inhibitory interactions between the neighbouring neurons was observed.

Animals↗
PubMed1991

[Methods of treatment of external fistula of gastrointestinal tract].

Experience in the treatment of external gastrointestinal fistulas in 1970-1988 consisted of 127 patients with 158 fistulas; 11 patients had a gastric fistula; 14, a duodenal fistula, 42, a fistula of the small intestine; 38, a fistula of the large intestine, and 22 patients had mixed fistulas. Operation for acute appendicitis was the main cause of fistula formation (20.3%). In undeveloped fistulas with considerable and uncontrolled loss of the intestinal contents, treatment consisted in early operation for vital indications for disconnection of the fistula, with preference given to complete bilateral disconnection. In developed fistulas most operations for their closure were carried out through an intraabdominal approach. Total mortality was 25.2%; in most of the fatal cases (90.6%) the fistulas were undeveloped.

Acute Disease↗
PubMed1990

[Surgical choices in the treatment of lung gangrene].

Patients with gangrene of the lung should be treated at a specialized thoracic department. Nonoperative treatment is justified only as preoperative management applied for no more than 2 weeks. Pneumonectomy is the operation of choice in gangrene of the lung. Pneumotomy may be conducted in patients who are in a very grave condition with respiratory and hemodynamic disorders.

Adult↗
PubMed1988

[Functional interneuronal connections in the motor cortex of waking and anesthetized cats].

Neuronal interconnections in the motor cortex of alert and anesthetized cats were studied using the techniques of multiunit activity recording and cross-correlative histograms. The number of neuronal interconnections did not decrease in cortical microareas during the deepening of anesthesia, but their reconstruction and levelling of inputs and outputs of all microareas' cells occurred. During the reconstruction of interrelationships among functional microareas an activation occurred in the neurons which had been rather inert in the cortex of alert cats. The data obtained suggest differential participation of the cat motor cortex' neurons in information processing at the level of microareas.

Action Potentials↗
PubMed1988

[Multineuronal activity of the cerebral cortex in cats during nembutal anesthesia].

In chronic experiments on cats, the multiunit activity was studied under action of small doses of nembutal (15 mg/kg) in the motor cortex. A different sensitivity to nembutal was revealed in the cells. Simultaneous recording of the multiunit activity in two microareas (within 270 mu) revealed that the change of mean firing rate recorded with different electrodes was reciprocal in a number of cases. Bursts of discharges were synchronous in a certain anesthesia stage in neighbouring microareas but the distribution was different. Thus, the use of light nembutal narcosis allowed to differentiate specific changes of the multiunit activity from the changes elicited by general synchronizing effects.

Action Potentials↗
PubMed1984

[Autodermal plasty in postoperative ventral hernias].

The method of autodermal plasty was used in 299 patients with postoperative ventral hernias. Among them great and giant hernias made up 62,8%. The autodermal method of plasty results in less amount of complications in the wound which can be explained by an increased concentrations of humoral non-specific defense factors in the operation field due to the effect of the skin flap. Remote results were followed in 84% of the patients during 2-6 years. Recurrences were detected in 3,2%.

Antisepsis↗
PubMed1981

[Convergence and divergence of interneuronal functional connections].

Multiunit activity was recorded in the auditory and motor cortex of cats with implanted electrodes, impulses with highest and lowest amplitudes being isolated by means of an amplitude discriminator. Crossinterval histograms were obtained for two simultaneous records. Functional relationships between neurons under different electrodes were evaluated by statistical interdependence of isolated trains. In the auditory cortex, neurons with high amplitude spikes mainly produced connections of excitatory type whereas neurons with low amplitude spikes produced connections of inhibitory type. In the motor cortex neurons producing heterogenous effect were predominant.

Animals↗