[Graphical monitoring of the artificial lung ventilation. Part 1. Graphs of gas pressure and flow rate during respiration cycle. Capnogram].

Graphical monitoring of the state of the system patient-apparatus for artificial lung ventilation (MLV) provides instant and illustrative information about the state of the system, which is particularly important under conditions of resuscitation and intensive care. Graphs of time dependence of gas pressure in respiratory pathways, gas flow rate, and changes of lung volume during respiration cycle provide on-line information about ventilation mode and patient state including lungs, respiratory pathways, positive pressure at the end of exhalation, etc. These curves allow MLV efficacy to be monitored and improved.

[Effects of cardiovascular therapy on risk of the development of ischemia and myocardial infarction in the postoperative period in cancer patients with ischemic heart diseases].

Analysis of 636 surgical interventions for malignant tumors in 576 chronic coronary patients showed that beta-blockers decreased the relative risk of ischemia and myocardial infarction during the postoperative period. Calcium antagonists verapamil and dihydropyridines also essentially decreased the probability of myocardial infarction and less so of myocardial ischemia. Antiischemic effect of nitrates was insignificant, and they increased the risk of myocardial infarction.

[High-frequency assisted air ventilation of the lungs during fiber bronchoscopy in cancer patients].

Bronchofibroscopy (BFS) in patients with respiratory failure caused by lung diseases and concomitant cardiovascular diseases involves deterioration of ventilation of the lungs. One of the most effective methods for preventing the complications is respiratory support by high-frequency assisted ventilation of the lungs (HFAVL). Oxygen is commonly used for this purpose, but its use can be limited by physiological and technological reasons.

[Critical phases of the brain development].

Various effects were shown to act alter the proceeding of histogenetic processes in the embryonic neural tissue. Studies in mice revealed that, depending on the embryogenesis stage when a lack of serotonin occurred, the lack of this monoamine entails either death of the embryo or a teratogenic effect, or underdevelopment of brain structures. In the rat model of a shorten hypoxia, a disorder of neural tissue histogenesis in early stages of development, was found, as well as a reduction of its sensitivity to lack of oxygen by the end of embryogenesis.

Antinociceptive effects of brain rewarding system in the developing rabbit: behavioral and electrophysiological analysis.

The modulating effects of electrical stimulation (ES) in the reward sites (RSs) of the hypothalamus and adjacent brain areas on the defensive reaction (DR) in response to peripheral noxious stimulation (PNS) and on evoked potentials (EPs) recorded in the thalamic centromedian-parafascicular complex (CM-Pf) to the same PNS have been investigated in 20-40-, 41-60-day old and 3-5-month old rabbits. Previously, RSs were identified by the method of intracranial self-stimulation (ICSS). Behavioral and electrophysiological testings successively performed on each rabbit first awake and then anaesthetized have revealed the ES in all investigated RSs to inhibit DR and EPs.

Role of the vagus nerves in neophobia and conditioned-reflex taste aversion.

Combination of ingestion of water with discomfort in rats with intact vagus nerves on selection between water and saccharine solution (an unknown taste) produced aversion not to water but to saccharine, with sharp increases in water consumption. In vagotomized rats, this combination led to a significant increase in saccharine consumption with no change in water intake. After extinction of neophobia to saccharine, combination of ingestion of water with rotation induced aversion to water in both groups (this being delayed in vagotomized rats).

Conditioned reflex responses of the sympathetico-adrenal system to an aversive taste stimulus.

Studies were carried out on male and female rats in which the effects of isolated presentation of a conditioned stimulus (a saccharine solution) to which the animals had previously developed conditioned reflex taste aversion (RTA) on the level of urinary catecholamine secretion were determined. The studies showed that presentation of an aversive taste stimulus without reinforcement by a negative stimulus increased the levels of urinary adrenaline, noradrenaline, and dopamine secretion; this repeated, albeit more weakly, the effects of the negative reinforcement (angular acceleration) used for development of RTA. After presentation of the isolated aversive taste stimulus, the greatest increase in catecholamine excretion affected adrenaline, which indicates an anxiety state (fear).

[The role of the vagus nerves in the manifestations of neophobia and conditioned-reflex taste aversion].

Vagotomized rats given a choice between water and an unfamiliar 0.2% saccharin solution ingest comparable amounts of both fluids over 2.5 weeks of testing.

[Physical features of high-frequency artificial ventilation of lungs].

The authors analyze main features of high-frequency forced ventilation of the lungs (HF FVL). Estimations indicate that the end-respiration pulmonary positive pressure inevitably develops during HF FVL; its value is 30 cm H2O and it starts no later than 10 sec after the beginning of HF FVL. Experiments showed that the maximal and minimal pressure of the respiratory cycle measured at the site accessible for measurements outside the device (at the exit) differ appreciably from pulmonary pressure which is clinically impossible to measure but is much more valuable.

[The conditioned-reflex reaction of the sympathoadrenal system to an aversive taste stimulus].

A non-reinforced taste stimulus with aversive properties was found to increase the level of excretion of adrenaline, noradrenaline and dopamine, thus reflecting occurring anxiety. The dopamine increase seems to be due to unspecific reasons of the experimental procedure. Catecholamines increase more in males rather than in females.

[Sex dimorphism in the patterns of conditioned-reflex taste aversion and orienting-exploratory and passive-defensive behaviors].

The patterns of conditioned taste aversion (CTA) and of some other types of behaviour were compared in adult male and female Wistar rats. Correlations between the CTA variables, on the one hand, and those of the exploratory and defensive behaviours, on the other, were shown. Females displayed initially less expressed CTA and more rapid its extinction than males.

[The characteristics of the effect of different shapes of the gas flow rate curves during artificial pulmonary ventilation].

Five curves reflecting the rate of gas flow into the lungs during artificial ventilation of the lungs (AVL) are compared. The estimations demonstrate that the optimal distribution of gas in the lungs is attained at the peak of the rate at the beginning and during the first third of inhalation phase. At a constant flow rate the increase of the volume is constant, at maximal flow rate at the beginning and during the first third of inhalation the highest increase of the volume is observed during the first third of inhalation, at sinusoidal and increasing flow it is observed during the second third of inhalation.

[The influence of naloxone on the antinociceptive effects of the brain system of negative reinforcement in the developing rabbit].

Participation of opioidergic mechanisms in implementation of inhibitory effects of the brain "punishment areas" upon nociceptive afferentation, was studied. The antinociceptive effect of electrical stimulation of the "areas" was either enhanced or reduced by naloxone depending on the current strength. The role of the opioids was shown to diminish with age.