[The Effects of Optokinetic Stimulation on Visual-Manual Tracking under Support-Proprioceptive Deprivation.]

To determine the effects of additional visual stimuli (retinal optokinetic stimulation - ROKS) on characteristics of the visual-manual tracking (VMT) without support and with decreased proprioceptive afferentation there was used a horizontal "dry" immersion. Altogether 18 subjects aged from 19 to 31 years participated in the study and they were submerged into the immersion bath from 5 to 7 days. There was evaluated performance of the VMT in tasks to pursue the jerky (saccadically) and smooth (linear, pendular and circular) movement of a point visual stimulus before, during and after immersion. Eye movements were recorded using electrooculography, hand movements - by ajoystick with a biological visual feedback (one of the two visible stimuli on the screen matched the current angle of thejoystick handle). Computerized visual stimulation programs were presented to subject using a virtual reality glasses with and without additional ROKS. We analyzed time, amplitude and velocity characteristics of the visual and manual tracking (VT and MT), including efficiency ratio (e) and gain (g) as ratios of respectively amplitudes and velocities of eyes/hand movements to the stimulus movement. Without ROKS efficiency ratio and gain of both VT and MT were significantly decreased in comparison with baseline during the whole immersion and up to the R + 3 day after. The most pronounced deterioration was observed in parameters of the VT. When using a "threshold" ROKS parameters of the VT and MT weren't changed before immersion, during and after immersion - they improved (on 1-5-7 days during immersion and on R + 3 day after there was a significant improvement of the VT and MT in comparison to same tests without ROKS). The greatest impact of the ROKS was observed in parameters of the VT. Evaluations of the vestibular function (VF) were performed before and after immersion using videooculography approach. We analyzed statical torsional otolith-cervical-ocular reflex (OCOR), dynamical vestibular-cervical-ocular reactions (VCOR) and vestibular reactivity (VR), spontaneous eye movements (SpEM). On R + 1 day after immersion in 28% of subjects there was found a significant decrease of the gain of OCOR (0.12 value in comparison to 0.25 baseline) with simultaneous significant increase of parameters of VCOR/VR. There was found a correlation between parameters of VT and MT, between VF and VT and no correlation between VF and MT. It was found that removal of the support and minimization of the proprioceptive afferentation has a greater impact-upon accuracy of the VT then accuracy of the MT. When using ROKS correlations between the studied parameters were not only preserved, but also intensified. The results obtained indicate the development of sensory deprivation (and afferent deficit) under the immersion exposure and the possibility of its correction with additional ROCKS.

[EFFECT OF REPEATED SPACE FLIGHTS ON OCULAR TRACKING].

The paper reports the results of studying the vestibular and ocular intersensory interactions and eye tracking function in 32 cosmonauts on maiden and repeated missions to the International space station. Mission duration ranged from 125 to 215 days. The cosmonauts were tested twice pre launch (baseline data collection) and on days R + 1/2, 4/5 and 8/9. Video oculography was used to test eye movements. It was found that in the majority of cosmonauts who had no experience of long-duration space missions the eye tracking function remained impaired significantly till R + 8/9. In cosmonauts who had already encountered with microgravity, obvious changes in eye tracking were observed on R + 1/2 only and, residual, on R + 4/5. On recovery, a new eye tracking strategy was acquired only by cosmonauts who had the first touch with spaceflight microgravity.

[VESTIBULAR FUNCTION AFTER REPEATED SPACE FLIGHTS].

Results of the vestibular function testing of 32 cosmonauts on return from repeated 125- to 215-day space flights (SF) on the International space station are presented. The cosmonauts were tested twice before flight (baseline data collection) and on days 1-2, 4-5 and 8-9 after landing. Electro- and video-oculography were used to register simultaneously eye and head movements. It was found that deadaptation following a repeated stay in long-duration SF takes statistically much shorter time. Most often, atypical vestibular disorders and changed patterns of the otolith-semicircular canal interaction are observed in cosmonauts who have made their maiden flights to microgravity.

[The effects of support-proprioceptive deprivation on visual-manual tracking and vestibular function].

To determine the effects of support and proprioceptive afferentation on characteristics of the visual-manual tracking (VMT) we used a model of weightlessness - horizontal "dry" immersion. Altogether 30 subjects who stayed in immersion bath from 5 to 7 days were examined to evaluate the accuracy of VMT in tasks to pursue the jerky (saccadically) and smooth (linear, pendular and circular) movement of a point visual stimulus. Examinations were performed before, during and after immersion using electrooculography (to record eye movements) and a joystick (to record hand movements) with a biological visual feedback - one of the two visible stimuli on the screen matched the current angle of the joystick handle. Computerized visual stimulation programs were presented to subject using a virtual reality glasses. We analyzed time, amplitude and velocity characteristics of the visual and manual tracking (VT and MT), including efficiency ratio (eVT and eMT) and gain (gVT and gMT) as ratios of respectively amplitudes and velocities of eyes/hand movements to the stimulus movement. eVT was significantly decreased in comparison with baseline all the time while subject lied in the immersion bath and until R+4 day after immersion, eMT was significantly decreased only on I-1 and I-3 days in immersion. gVT significantly differed from baseline only on I-3 and I-6 days in immersion and R + 1 day after immersion. We found no significant changes in gMT. Evaluations of the vestibular function (VF) were performed before and after immersion using videooculography approach. We analyzed statical torsional otolith-cervical-ocular reflex (OCOR), dynamical vestibular-cervical-ocular reactions (VCOR), spontaneous eye movements (SpEM), the accuracy of perception of subjective visual vertical (SVV). After immersion 47% of subjects had significant decrease of OCOR with a simultaneous significant increase of VCOR on 37% of subjects as well as significant changes in accuracy of perception of SVV which correlated with changes in OCOR. We found correlation between characteristics of the VT and MT, between characteristics of the VF and VT and found no correlation between VF and MT. It was found that removal of the support and minimization of the proprioceptive afferentation has a greater impact upon accuracy of the VT then accuracy of the MT.

[The medical social stipulation of reproductive behavior of female patients with inflammatory diseases of genitals].

The article presents the characteristics of reproductive behavior of women aged 18-27 years with inflammatory diseases of genitals. It is established that according the sociological survey, female patients with mentioned diseases and having low level of medical sanitary knowledge are characterized by unsatisfactory material conditions of life and living, early age of sexual debuts, sexual promiscuity, frequent premarital conceptions, low indicator of nuptiality, low culture of family planning and reproductive activity.

[Effect of a real and simulated weightlessness on characteristics of the static torsional otolith-cervical-ocular reflex].

To determine the role of the support-proprioceptive factor in the functioning of the vestibular system, in particular the static torsional otolith-cervical-ocular reflex (OCOR), comparative OCOR studies with videooculography recording were performed after a 7-day "dry" horizontal immersion (16 immersion subjects) and after a prolonged (126 to 195 days) exposure to weightlessness (14 ISS cosmonauts). For the first time it was demonstrated that minimization of the support and propripceptive afferentation may results in an inversion or absence of the static torsional OCOR and the development of a positional nystagmus with an inverted reflex. A comparative OCOR data analysis of cosmonauts and immersion subjects has revealed similarity of responses. However, changes in OCOR after immersion were noted in only 60% of subjects, while after space fight, 90% of cosmonauts showed them. Post-flight changes were more frequent, marked and long-lasting.

[Visual-manual tracking during 5-day dry immersion].

Level dry immersion (DI), a model of the physiological effects of microgravity, support deprivation, minimization of muscle activity and proprioceptive afferentation specifically, was used to determine the effects of low proprioceptive, tactile and support afferentation on visual-manual tracking. Hand-eye motor coordination was tested in 13 subjects in 5-d DI who tracked jerky and smooth (linear and pendulum-like horizontal and vertical, circular clockwise and counterclockwise) motions of point visual stimulus. Binocular electrooculography was used to register ocular movements and a joystick with a biological visual feedback to register manual motor acts (1 of 2 stimuli on the screen showed the actual joystick inclination). Computerized stimulation was provided with the help of virtual goggles. Evaluated parameters were latent and total reaction time, amplitude and velocity of eye and hand movements, coefficients of effectiveness (amplitudes ratio) and gain (velocity ratio). Testing was performed before DI, after 3 hours in DI, on DI days 3 and 5, during the first hours and in 3 days after DI (all subjects) and on post-DI days 5-7 (4 subjects). It was demonstrated that support deprivation and minimization of proprioceptive afferentation affect ocular tracking to a larger degree than accuracy of the manual motor act of following the visual stimulus. Manual tracking by all subjects was found more accurate than visual and did not alter significantly during tests sessions; on the contrary, visual tracking accuracy altered noticeably as in the course, so after DI.

[Computerized methods for therapy and rehabilitation of patients suffering dizziness and balance disorder].

A new computerized method is proposed for correction and inhibition of unfavorable illusory (vertigo), vestibular-oculomotor (nystagmus), and vestibular-postural (balance) responses. This method allows to teach the subject to block generalization of an afferent signal to effector mechanisms of the central nervous system by developing a fixational reflex, utilizing a delayed biofeedback. Three variant ofthis method were employed, depending on the kind of stimulation programs aimed at inducing abnormal responses of a certain sensory modality (visual, vestibular or combined). The study involved 36 subjects divided into 3 equal groups one of which had been taught by a visual or vestibular technique, and the last one by a combined. Each group included approximately equal numbers of subjects with vestibulopathies of an organic (peripheral or central) or psychogenic origin. It was demonstrated that the method proposed allows, with the help of computerized stimulation programs, to provoce abnormal illusory and vestibular-optooculomotor responses in the subject, and inhibit them with the help of development of a fixational reflex. Patients were taught using three various variants of the method. A subsequent comparative analysis of results obtained has shown dependence of their effectiveness on the level of disturbance in the vestibular system: the visual variant of correction was the most effective for subjects with peripheral vestibulopathia; for subjects with central vestibulopathia, the vestibular variant was more effective; the combined variant of correction was the most effective for subjects with psychogenic vestibulopathia.

[Computer-aided techniques for the treatment and rehabilitation of patients suffering vertigo and balance disorders].

A new computerized method is proposed for the correction and elimination of undesirable illusory sensations (dizziness), vestibulo-oculomotor (nystagmus), and vestibulo-postural (imbalance) reactions. The method allows to teach the subject about how to avoid generalization of afferent signals over the effector mechanisms in the central nervous system by developing a fixational reflex employing delayed biological feedback for the assessment of efforts being exerted (self-control of training results). Three variants of application of this technique were evaluated depending on the type of stimulation software intended to induce illusory and oculomotor reactions of a defined sensory modality (visual, vestibular or combined). The study involved 30 subjects divided into three groups. They had been taught using the visual (group 1), vestibular (group 2) or combined (group 3) methods. Each group was comprised of an approximately equal number of subjects with vestibulopathies of either peripheral or central origin. The study demonstrated that the proposed approach allows to invoke, with the use of a computer stimulation software, abnormal illusory and vestibulo-oculomotor responses and inhibit them by developing the adequate fixational reflex. Comparative analysis of the results obtained by teaching the patients with the help of the three different methods revealed the dependence of their effectiveness on the level of disturbances in the vestibular system. The visual method of correction proved to be especially efficacious for the patients with peripheral vestibulopathy, and the vestibular methods for the patients with central vestibulopathy. Patients with combined peripheral and central vestibulopathy required the choice of training modalities (either visual or vestibular) on an individual basis.

[A computerized method for the combined evaluation of otoneurological and non-pharmacological correction of vestibulo-sensory and oculomotor disturbances].

Methodology and a new <> hard/software complex (HSC) have been developed jointly by the Institute of Biomedical Problems, <> and <> Companies to be used in vestibulometric, otoneurological, and psychophysiological tes-ting with synchronous registration and in the analysis of head movements, various types of nystagmus, and all forms of visual pursuit. The complex is intended for the expert/diagnostic evaluation, prognosis, and monitoring of the vestibular function, intersensory interactions, and eye pursuit movements as well as for teaching correction and elimination of unfavourable perceptive and vestibular-sensorimotor responses by developing a fixation reflex during exposure to visual and dynamic stimuli. The <> HSC was tested during pre- and post-flight observation of astronauts, under simulated and clinical conditions, as well as in monitoring the functional status of athletes engaged in various sports. The study has demonstrated that the use of special computerized stimulation programs allowing (by irritating visual and vestibular sensory inputs) to produce perceptive and sensorimotor responses provides a promising tool for the evaluation of the state of the vestibular and related sensory systems, stability of static and dynamic spatial orientation in the presence of separate and combined visual and vestibular stimuli or without them.

[Visual-manual tracking and vestibular function during 7-day dry immersion].

The seven-day DI experiment provided an opportunity to study the effects of decreased proprioceptive, tactile and support afferentation on the vestibular function and visual-manual tracking. Before and after immersion, six subjects participated in videooculographic evaluation of the static torsion otolith-cervicoocular reflex (OCOR) in response to head inclination at 30 degrees in the frontal plane and dynamic vestibular-cervicoocular reactions to head longitudinal rotations at 0.125 Hz. In addition, the hand-eye motor coordination of tracking a jerky (sinusoidal) or smooth (linear) movement of point targets along the horizontal or the vertical was evaluated based on the data of electrooculography and records of manipulations with the joystick during immersion. The computerized test was performed in virtual spectacles dsplaying images of visual stimuli and hand motor acts. Computed parameters included latent reaction time, amplitude, speed and time of eye and hand movements, and gains of optooculomotor reactions and manual tracking as a ratio of eye/hand to visual stimulus speed. Testing was fulfilled before the experiment, in 3 hrs. of immersion, on days 3 and 6 of staying in the bath, in the initial hours after immersion, and on day 3 of recovery. It was shown that removal of support and minimization of proprioceptive afferentation had a profound effect on the ocular tracking rather than hand pursuance of visual stimulus. Accuracy of manual tracking was better comparing with the eye tracking in all the subjects. This was the first time when we observed changes in the peripheral vestibular system in two out of 6 subjects, i.e. inversion of static torsion OCOR and positional nystagmus on the background of converted reflex which did not mar the parameters of oculo-manual tracking.

[Mechanical suture at the surgery of perforated ulcer].

Original spring clip for laparoscopic suturing of perforated ulcers was studied experimentally on rabbits. These clips were used at 26 patients. Mean time of surgery was 17 min, hospital stay -- 5,8 days, there was one complication. Suturing of perforated ulcer with spring clip and additional antiulcer therapy during 10-12 days led to ulcer healing at 96,2% cases.

[Effect of long-term microgravity on the vestibular function].

Comprehensive computerized oculomotor testing was used to investigate the vestibular function in 9 Russian members of ISS crews 3-9 on days 1 (2), 4 (5) and 8 (9) of return from long-term stay in microgravity (126 to 195 days). The vestibular function was assessed by the static otolith-cervical-ocular reflex, dynamic otolith-cervical-ocular reactions, vestibular reactivity, and spontaneous oculomotor activity. The postflight investigations revealed functional disorders in the peripheral (an increased vestibular reactivity, absent or damped otolith-cervical-ocular reflex), and central (spontaneous typical and atypical nystagmus, gaze nystagmus) vestibular analyzer. The pattern and extent of vestibular disorders after long-term exposure in microgravity were individual by character; however, some of the vestibular reactions, including disappearance or considerable damping of the static otolith-cervical-ocular reflex, exaggerated vestibular reactivity and spontaneous eye movements, displayed consistency.

[Laparoscopic resection of the stomach by Billroth-I technique]. / Laparoskopicheskaia rezektsiia zheludka po Bil'rot-I.

Laparoscopic resection of the stomach by Billroth-I technique is described. Previously different variants of laparoscopic Billroth-II resection and laparoscopy-assisted Billroth-I resection have been performed a complete variant of laparoscopic Billroth-I resection of the stomach the authors reported on Symposium of Endo-surgeons in 2004.

[Computerized method of objectification of dizziness and vertigo and differential diagnostic of vestibulopathies].

OBJECTIVE: To create a complex computerized method of objectification of dizziness and vertigo, and differentiation of vestibulopathies of various geneses using electrooculography approach that allows to record and analyze spontaneous, vestibular- and visually-induced eye movements, with the following classification (discriminant) analysis of the results obtained. MATERIAL AND METHODS: The study involved 69 patients of different sex and age complained of dizziness, vertigo and disequilibrium, and 64 healthy men. Based on the results of clinical examination, patients were divided into three groups: patients with peripheral vestibulopathy, patients with central vestibulopathy and patients with psychogenic vestibulopathy. Electrooculography was performed using the hardware-software complex (HSC) "OCULOSTIM-CM". RESULTS AND CONCLUSION: Significant diagnostic parameters based on the recognition and analysis of spontaneous, vestibular- and visually-induced eye movements were coefficients of efficacy and increased frequency of fixation saccades and smooth pursuit with- and without retinal optokinetic stimulation. We developed the algorithm and complex computerized method for differentiation of different types of vestibulopathy.

[Ultrasonic examination of gastric stump and gastroenteroanastomosis in complex diagnosis of postresection dumping syndrome]. / Ul'trazvukovoe issledovanie kul'ti zheludka i gastroénteroanastomoza v kompleksnoi diagnostike postrezektsionnogo demping-sindroma.

Long-term results of laparoscopic resections of the stomach were studied, a comparative analysis with similar open surgeries was carried out. The comparative analysis was based on the results of ultrasonic examination (USE) of the gastric stump (GS) and gastroenteroanastomosis (GEA). Basing on ultrasonic parameters of GS, digital parameters of GEA in mild, moderate and severe degree of dumping-syndrome were determined. Ultrasonic examinations of the gastric stump permitted to study its function in dumping-syndrome of different degree, to reveal sizes of GEA in relaxation and contraction stage, and based on these data to determine its gradients of contractility. Ultrasonic method in long-term period after resection of the stomach has advantages compared with gastroscopic and X-ray methods.

[The differential diagnosis of peripheral and central vestibulopathies by the characteristics of eye movements].

The article addresses the development and approbation of operative and low cost computer methods of the differential diagnosis of peripheral and central vestibulopathies using the integrated hard-and software system "Okulostim-KM". Two groups of patients with central (CV) and peripheral vestibulopathy (PV) were tested. A total number of characteristics of eye movements in response to vestibular (active head rotations in different planes) and visual (spasmodic and smooth movements of a point target on the screen in the absence and during the retinal optokinetic stimulation) stimuli were used. Eye movements were recorded using electrooculography. A set of diagnostic criteria for each group of vestibulopathies allowed to specify disease type at a subclinical stage in 88,9% of patients with CV and in 95,8% of patients with PV. The use of the computer tests may be helpful in a timely diagnosis and treatment of vestibular disorders.

[The therapy of patients with dizziness and balance disorders].

A new computerized method is proposed for correction and inhibition of unfavorable illusory (dizziness), vestibular-oculomotor (nystagmus) and vestibular-postural (balance) which allows to teach a subject to block generalization of an afferent signal to effector mechanisms of the central nervous system by developing a fixation reflex, employing a delayed feedback. Two ways of using this method were employed depending on the kind of stimulation programs aimed at inducing abnormal responses of a certain sensory modality (visual or vestibular). The study involved 24 patients with vestibulopathies of peripheral and central origin divided into 2 equal groups one of which had been taught by a visual technique, the other - by a vestibular one. The method allows to produce abnormal illusory and vestibular optic oculomotor responses in the patient and inhibit them with the help the fixation reflex development. The visual way of correction was the most effective for patients with peripheral vestibulopathia and the vestibular way - for patients with central vestibulopathia.