Intersystem relationship between respiration and blood circulation

Current data on the functional interaction between the respiratory and circulatory systems under different living conditions are reviewed. Special attention is focused on adaptive changes in the respiratory and hemodynamic parameters under extreme conditions. Based on the data in the literature and our own findings, physiological parallels between intersystem correlations of respiratory biomechanics and hemodynamics under normal- and weightlessness conditions are drawn.     

Influence of examination stress and psychoemotional characteristics on the blood pressure and heart rate regulation in female students

During the semester and immediately before an examination, changes in the heart rate variability, blood pressure, and state anxiety induced by examination stress, as well as the dependence of these changes on the probabilistic prediction and actual examination mark, were investigated. Before an examination, most students exhibited an increase in state anxiety, diastolic blood pressure, and heart rate; the last of these is connected with an increase in the LF/HF ratio. The behavior of the cardiovascular system of the students (who were females) under psychoemotional stress varied considerably depending on how well they were prepared for the examination and on the subjective prediction of success. The importance of the type of heart rate regulation during the semester for the progress of examination stress was established.     

Chronic stress and forming of psychoemotional state during prepubertal period in rats

Immediate and long-lasting effects of chronic stress during prepubertal period (21-32 postnatal days) on anxiety- and depression-related behavior were studied in Wistar and ISIAH (inherited stress-induced arterial hypertension) rats. Significant interstrain differences were found. Both juvenile and adult ISIAH rats were less anxious in the elevated plus-maze and less depressed in the forced swimming test. Immediate effects of the prepubertal stress were similar in both rat strains and depended on the type of stimulation. Long-lasting effects were genotype-dependent. Chronic prepubertal handling exerted an anxiolytic effect in young ISIAH and Wistar rats and adult Wistar rats. Immediate anxiogenic effect of prepubertal unpredictable stress was preserved only in adult ISIAH rats. Depression-related behavior was intensified by the unpredictable stress in young animals, whereas the long-lasting effect was observed only in adult hypertensive rats.     

Interrelationship between NAD metabolism and DNA synthesis in chicken liver nuclei during ontogenesis]

The content of NAD and DNA, the activity of DNA-polymerase the velocity of NAD pyrophosphorolysis have been studied in liver nuclei of 8, 14, 18 day-old chicken embryos and 1--2 month- and 6 month-old chickens. It has been found that during ontogenesis the NAD content in chicken liver nuclei is increased, whereas the DNA content is decreased, the correlation coefficient being--0,93. The DNA-polymerase activity is the highest in the liver nuclei of 8--14 day-old embryos. During ontogenesis the DNA-polymerase activity is decreased. The excess of inorganic pyrophosphate shifts the NAD synthesis reaction to the left and activates the NAD pyrophosphorolytic degradation. During chicken ontogenesis the maximal NAD pyrophosphorolytic degradation is observed during the embrionic period.     

Regulation of respiration and pulmonary blood circulation in experimental pneumonia

The experiments on anesthetized cats were carried out to determine the functional state of respiration centre (impulse activity of genuine respiration neurons and electrical activity of major and additional respiration muscles). Functional peculiarities of macro- and microcirculation of the lung tissue were also studied in the open and closed chest in normal subjects and in conditions of experimental pneumonia.     

Interrelationship between glucoside-bound and free alcohols during ether oil formation in rose petals]

Some data on the dynamics of free and glucoside-bound monoterpenic and aromatic (beta-phenylethyl) ethers content and the changes in the beta-glucosidase activity in rose petals at different stages of the flower development and on the kinetics of enzymatic hydrolysis of these glucosides are presented. The phase specificity of beta-glucosidase coinciding with the maximal accumulation of glucoside-bound and free alcohols is revealed. The data obtained suggest that the formation of glucosides may precede the accumulation of corresponding free alcohols of terpenic and aromatic origin.     

Prophylactic effect of antioxidant Aekol on behavioral (psychoemotional) disturbances caused by chronic stress in rats

Antioxidant preparation "Aekol" containing vitamins A, E, and K3, was shown to possess antidepressant properties and to exert a prophylactic effect on behavioural (psychoemotional) disturbances induced by a chronic stress in rats: a depressive condition associated with an enhanced anxiety, elimination of individual differences in behaviour, weakening of the relationships among behavioural parameters recorded in the same animal in three different tests.     

Interrelationship between immunologic and neurologic memory: learning ability of rats during immunostimulation]

Studies have been made on the effect of an immunostimulator - the complete Freund's adjuvant - upon the learning ability in Wistar rats for visual discrimination using food-obtaining and avoidance of the electric shock techniques. Injection of the adjuvant significantly increases learning ability provided negative reinforcement technique is used, but inhibits the former under the conditions of positive reinforcement. Analysis of the extinction of the conditioned reflexes yielded similar results. Possible relation of immunogenesis to the formation of memory is discussed.     

Pathological and compensatory processes in the cerebral circulation during blood transfusion shock]

In experiments on dogs the intravenous injection of heterogenous blood resulted in a decrease of total arterial pressure, weakening of the brain blood flow, fall of Po2 and pH in the brain cortex. A simultaneous constriction if inner carotid arteries is depending on direct action on the vascular wall of heterogenous proteins and on a release in it of physiologically active substances, such as serotonin. Fine pial arteries were dilated by the compensatory mechanism that was not associated with a decrease of intravascular and with direct action of hypoxia or acid metabolites on vascular walls. It was proposed that the trigger mechanism of this vasodilatation is hypoxic changes of metabolism in the nervous tissue.     

Relationship between hypercapnic and hypoxic stimuli of respiration during muscular activity]

Pulmonary ventilation (V) and alveolar gas composition (PACO2, PAO2) were studied in 12 healthy men who performed gradual muscular work under conditions of controlled hypercapnia, hypoxia, hyperoxia or their combinations. The respiratory response was estimated by absolute values of ventilation at the given PACO2 value and by its rise by 1 mm Hg of increased PACO2 (delta V/delta PACO2) under rest and under transitional and steady-state exercise. The exercise on-switch was accompanied by displacement to the top and an increased slope of the response curve (delta V/delta PACO2) not related to the work load. These changes suggest multiplicative interaction of the neurogenic and hypercapnic drives in the load switch-on. During steady-state exercise an important role of the hypoxic drive was revealed: hypoxemia induced a shift of the delta V/delta PACO2 response curve to a higher level, especially with the great work load. Thus the positive interaction between the hypercapnic and hypoxic respiratory drive augments with muscular exercise.     

Recurrent posterior circulation infarction caused by anomalous occipital bony process in a young patient

Background

Structural anomaly of the cervical spine or craniocervical junction has been reported as one of the rare causes of ischemic stroke. We report a case of a young patient with recurrent posterior circulation infarction that may have been associated with an anomalous occipital bony process compressing the vertebral artery.

Case presentation

A 23-year-old man experienced recurrent posterior circulation infarction 5 times over a period of 5 years. He had no conventional vascular risk factors. Young age stroke work-up including thorough cardiac, intra- and extracranial vascular evaluation and laboratory tests for the hypercoagulable state or connective tissue disease yielded unremarkable results. An anomalous bony process from the occipital base compressing the left vertebral artery was observed on brain CT. All the recurrent strokes were explainable by the arterial thromboembolism originating from the compressed left vertebral artery. Therefore, the left vertebral artery compressed by the anomalous occipital bony process may have been the culprit behind the recurrent thromboembolic strokes in our patient. Intractable recurrent strokes even under optimal medical treatment led us to make a decision for the intervention. Instead of surgical removal of the anomalous occipital bony process, the left vertebral artery was occluded permanently by endovascular coiling after confirming that this would cause no neurological deficits or flow disturbance in the posterior circulation. There was no recurrence of stroke for 2 years after permanent occlusion of the left vertebral artery.

Conclusion

Arterial thromboembolism originating from the left vertebral artery compressed by the anomalous occipital bony process is a rare but not to be overlooked cause of posterior circulation infarction. When intractable to medical treatment, endovascular occlusion of the vertebral artery without flow disturbance to the posterior circulation may be a useful treatment option when surgical removal is not feasible.

     

The coordination and interaction between respiration and deglutition in young pigs

The anatomical pathways for inspired air and ingested food cross in the pharynx of mammals, implying that breathing and swallowing must be separated either in space or in time. In this study we investigated the time relationship between swallowing and respiration in young pigs, as a model for suckling mammals. Despite the high morphological position of the larynx in young mammals, allowing liquid to pass in food channels lateral to the larynx, respiration and swallowing are not wholly independent events. Although, when suckling on a veterinary teat, the swallows occurred at various points in the respiratory cycle, there was always a period of apnea associated with the swallow. Finally, an increase in the viscosity of the milk altered this coordination, changing respiratory cycle length and also restricting the relative rate at which swallows occurred in some parts of the respiratory cycle. These results suggest that the subsequent changes in respiratory activity at weaning, associated with passage of a solid bolus over the larynx, is preceded by the ability of the animal to alter coordination between respiration and swallowing for a liquid bolus. Accepted: 29 September 1997     

Interrelationship between the neocortex and limbic system in emotional stress and epileptiform syndromes

The paper describes bioelectrical correlates of negative emotional states on three models: 1) states caused by local, chronic electric stimulation of negative emotiogenic zones (in cats, rabbits); 2) by a neurogenic stress in rats resulting from a conflict of afferent excitations; 3) by an experimental syndrome--"expectation stress". The data attest that hypersynchronization of bioelectrical activity in limbic and cortical structures is a sufficiently significant correlate of an emotional stress. It is assumed that hypersynchronization reflects one of the general mechanisms of involvement of brain structures in a state of neurogenic stress and its manifestation.     

Relation between the psychoemotional state and the heart rate regulation and immune status in human]

Change of heart rate variability in orthostatic test and immunologic parameters in healthy persons depend from their anxiety. Anxious persons were characterized by increase of sympathetic nervous activity at baseline and in orthostatic test, stimulation of immunologic parameters. In persons with high trait anxiety and not high state anxiety immunosuppression and failing of sympathetic nervous activity were found. In unanxious persons prevalence of parasympathetic nervous activity in heart rate regulation and intermediate immunologic parameters were revealed.     

Interrelationship between toxigenic and non-toxigenic diphtheria microbes in the epidemic process]

A study of the circulation of toxigenic and nontoxigenic diphtheria bacilli was carried out in several carrier state foci under conditions of a natural course of the epidemic process. There were 2623 persons under observation. A total of 32158 analyses were carried out, and 2271 strains were isolated and studied. No formation of the toxigenic variants of diphtheria bacillus as a result of phage conversion was revealed in the foci of carrier state despite the wide spread in them of nontoxigenic lysosensitive cultures capable of acquiring the toxigenic properties under experimental conditions, and of the cultures which had converting corinephages. Thus, autonomy of the circulation of the toxigenic and nontoxigenic diphtheria bacilli occurred in the carrier state foci; the leading role in the change of the diphtheria bacillus type belonged to reinfection.