A possible anatomical and biomechanical explanation of the 10% rule used in the clinical assessment of prehensile hand movements and handed dominance.

Unlabelled: A current doctrine in the dynamometric approach to determine lateralization of hand function states that in 10% of cases, the non-dominant hand will be stronger than the dominant hand. In this study, a novel MRI based modelling approach was applied to the first dorsal introsseus muscle (FDI), to determine whether the 10% rule may be applied to the FDI and may be partially explained by the arrangement of the anatomical components of the FDI.

Methods: Initially the force generated by the thumb segment during an isometric pushing task in the horizontal plane was measured from 25 strongly right-handed young males.

[Asymmetry of the viscoelastic properties of the skin and muscle compartments of the left and right hands].

The aim of this research was to discriminate and categorize isolateral stress-strain characteristics contained within the musculocutaneous compartment (MCC) using the model of the first dorsal interosseous muscle (FDI) in vivo. In our approach, the musculocutaneous compartment of the dorsal interosseous muscle was progressively isokinetically compressed by a solid vertical bar with a 0.25 mm incremental step.

[Effect of estrogens on the coronary circulation, cardiac contractile function, and development of reperfusion arrhythmia].

17-beta-estradiolsulfate (17-ES) was shown to exert a distinct vasoconstrictory effect on coronary vessels resulting in a decrease of the force contraction as well indexes of contractility. The distinct antiarrhythmic effect suggests that 17-ES possesses some properties of calcium antagonist.

[Regulation of vertical posture in patients with children's cerebral paralysis treated with the method of proprioceptive correction].

Maintenance of vertical posture is a complex coordination act dependent on a multi-level system of regulation. Functional state of the visual system may contribute significantly to the implementation of the mechanisms of vertical posture maintenance. Stabilographic examination of healthy teenagers and patients afflicted with the main CCP forms with the method of dynamic proprioceptive correction revealed dependence of posture stability and involvement of the visual analyzer on sex.

[Use of computer-assisted stabilography and the method of computer-assisted biomechanical study of gait in the diagnosis of posture and motor disorders in patients with different forms of infantile cerebral paralysis].

The paper presents and analyzes the results of assessment of vertical stability and walk in patients with infantile cerebral paralysis before and after dynamic proprioceptive correction, which is of great importance for differential diagnosis of different forms of this disease, for controlling the course of therapeutical measures, for working out criteria for the efficiency of treatment.

[The individual profile characteristics of cerebral interhemispheric asymmetry during visual stimulation in healthy subjects and in patients with the spastic form of infantile cerebral palsy].

Individual profiles of brain interhemispheric asymmetry (IPA) and stability in maintenance of the vertical posture have been studied in healthy children and adults and patients with the spastic form of the infantile cerebral palsy before and after visual stimulation. The IPA were built on the basis of motor asymmetry of hands, asymmetry of visual half-fields, and asymmetry of muscle extension tone in vertical position in Romberg test at computer stabilograph. The visual stimulation was realized by unilateral tachistoscopic administration of a verbal stimulus in the visual half-field on the side of worst detection of the master stimulus during the procedure of initial IPA construction.

[Effect of ionospheric parameters on the respiratory and cardiac system, function of the brain and higher nervous system activity in healthy people].

Effects of complex ionospheric parameters on the parameters of 4 systems of healthy people: respiration and cardiological systems, functions of brain and central neural activity, were studied. Results indicating the presence of highly significant multiple correlations of these biosystems with the complex of ionospheric parameters were received.

[The influence of space loading suits on interhemispheric asymmetry of the brain in infantile spastic cerebral palsy].

The paper presents the study concerning influence of somatosensory stimulation (single wearing of either space loading costume "PENGUIN" or its modification--"ADELY" costume) on the individual profile of interhemispheral cerebral assymmetry (IPIHCA) in patients with spastic form of infantile cerebral paralysis (ICP). The computer stabilograph analyzed motor arms' asymmetry, sensory asymmetry of visual hemiareas, asymmetry of the position of centre of gravity. It is shown that peculiarities of the realization of the standing position either with visual control or without it both in healthy individuals and in patients depended on initial IPIHCA.

[Changes in individual profiles of cerebral hemispheric asymmetry during somatosensory stimulation due to wearing of G-suits by healthy adults and children].

Presented are results of the investigations of individual profiles of the brain interhemispheric asymmetry (IPIHA) in healthy grown-ups and children prior to, during, and immediately after somatosensory stimulation. The somatosensory stimulation was performed by one-time wearing of space g-loading suit PENGUIN and its modification ADELIE. IPIHA was studied by the main functional asymmetries including motor hand asymmetry, sensory asymmetry of the visual hemispheres, body mass center asymmetry (BMA) using a computerized stabilimeter indirectly measuring the muscle tone of contralateral extensor.

[The significance of visual analyzer in controlling the standing posture in individuals with the spastic form of child cerebral paralysis while wearing "Adel" suit].

The paper discussed the results of stabilographic examination of the children suffered from the spastic form of child cerebral paralysis (CCP) treated by means of graded wearing of "Adel" suit which is a modification of the "Penguin" spacesuit. There has been studied the state of 30 children before treatment with the use of "Adel" suit and after the treatment as well as following the several courses of wearing the suit. Besides the patients, eleven healthy volunteer subjects (control group) were examined.

[Role of vestibular and visual analyzers in changes of postural activity of patients with childhood cerebral palsy in the process of treatment with space technology].

The paper presents the findings of stabiligraphic investigations of children afflicted with the hyperkinetic child's cerebral paralysis treated with the method of graduated wearing suit ADELI. This suit is a modification of space-designated PINGUIN used to counteract the adverse effect of long-term microgravity on the skeletal muscles and the skeleton. 30 children were investigated prior to, immediately after, and in a delayed period after this treatment.

[Myocardial heterogeneity and cardiac arrhythmias].

Analysis of publications according to which myocardium consists of heterogeneous elements functioning as the whole. Evolution of ideas about structural-functional organization of heart tissue is shown. The conception and model of cluster structural-functional organization of myocardium are formulated.

[Sympathetic control of spontaneous cardiac defibrillation].

The parameters of transmembrane potentials of cardiomyocytes and dynamics of fibrillation process have been investigated when altering the level of sympathetic action on the heart by injection of rausedile, katecholamines and by stimulation of the nucleus of hypothalamus. It was shown that the injection of rausedile decreases rest potential and potential activity, meanwhile electrical irritation significantly increases the period of spontaneously reversible fibrillation.

[Effects of bonnecor on transmembrane potentials of cardiomyocytes of the ventricular contractile myocardium of the intact heart and ventricular fibrillation].

The microelectrode technique has shown that bonnecor given in a dose of as many as 2 mg/kg increases the action potential amplitude, but when its dose is increased up to 3 mg/kg, the agent decreases the action potential amplitude of ventricular cardiomyocytes in the guinea-pig, the resting potential remaining steady. Administration of bonnecor prevents ventricular fibrillation after aconitine application and provokes ventricular fibrillation and flutter when the focus of ectopic automatism is formed.

[Role of heart mass in the spontaneous defibrillation process].

The duration of periods of the spontaneous reversible fibrillation of heart ventricles of different masses of guinea pigs, rabbits, pigeons and chickens was investigated. It was demonstrated, that a heart mass doesn't play an important role in the process of spontaneous heart ventricles defibrillation. Only the number of strong contacts and the level of the parasympathetic control are determined.

[Prevention of myocardial reperfusion injury by increasing artificial trans-membrane sodium gradient in "calcium paradox" and post-ischemic reperfusion].

An effect of the high sodium gradient during "calcium paradox" and postischemic reperfusion has been studied. A decrease of Na/Ca exchange by high sodium gradient (200 mM NaCl in the perfusion solution) resulted in the reduction of myoglobin release from the heart during "calcium paradox". High sodium concentration solution (200 mM) increased protective effect of ATP during "calcium paradox".

Parasympathetic control of the spontaneous defibrillation of the heart ventricles in animals of various ages.

The role of the parasympatetic division of the nervous system in the process of the spontaneous defibrillation of the heart ventricles in guinea pigs of various ages has been investigated. It was shown that the intensification of parasympathetic control in newborn and sexually mature animals by means of the stimulation of the vagus nerves through the administration of acetylcholine leads to an increase in the duration of ventricular fibrillation, while in old animals this leads to the possibility of its prevention. The important role of the maintenance of sympathetic control in the mechanisms of the recovery of normal cardiac rhythm has been demonstrated.

[Spontaneous ventricular defibrillation in hypothermia].

'Floating' microelectrodes were used to examine the transmembrane potentials of left and right ventricular cardiomyocytes in the guinea pig exposed to deep cooling. In the wide range of temperatures (37 to 20 degrees C), the transmembrane potentials did not substantially change, no fibrillation occurred. There may be a spontaneous reversible ventricular fibrillation in hypothermia where asynchronous excitation of myocardial cells occurs during cell membrane depolarization, which is essentially less than at normal body temperature.

[Cardiac fibrillation in early ontogeny in animals born mature and immature].

The processes of spontaneous reversible fibrillation were compared in mature-born (guinea pigs, hens and cocks) and in immature-born animals (cats, dogs and rats). An increase in duration of the fibrillation in immature-born animals was most significant in the period of recovery of sight which is associated with an increasing parasympathetic influences.

[The parasympathetic control of spontaneous ventricular defibrillation in animals of different ages].

The enhancement of parasympathetic control in newborn and mature guinea pigs, achieved through vagal stimulation and acetylcholine administration, was shown to increase the duration of spontaneously reversible fibrillation of the heart ventricles. Acetylcholine administration could prevent spontaneously irreversible fibrillation of the heart ventricles in old animals. The preservation of sympathetic control was shown to be important for the mechanisms of spontaneous restoration of normal cardiac rhythm.