Biomedical subjects
Publications and source records attributed to V V Poliakov.
The authors review the experimental and theoretical studies of eminent Russian scholar A.L. Chizhevsky, and his fruitful collaboration with K.E. Tsiolkovsky, a pioneer of the science of rocket navigation. Highlighted are postulates of the modern space biorhythmology furthering the notions of A.L. Chizhevsky about the harmony in nature, and significance of rhythmic phenomena for living organisms.
Results of experimental evaluation of the performance of pilots bound to stay up to 24 hrs in the working pose as a function of inclination of supporting surfaces (backrest and seat) are presented. Small inclination angles (up to 23 degrees) were found to be more provocative of discomfort, painful sensations and work deterioration characterized by higher intensity. It was shown that periodic change of the seatback inclination is an effective way to prevent fatigue in pilots on long-duration flights and to prolong time of comfortable stay in forced posture up to 12-16 hrs. The data on the time of comfortable stay and dynamics of pilot's performance as a function of angles of supporting surfaces of the seat laid the grounds to determination of the best combination to provide comfort to pilot on flight.
Explore the source record for details and available documents.
Results of the joint Russian/US studies of the effect of microgravity on bone tissues in 18 cosmonauts on return from 4.5- to 14.5-month long missions are presented. Dual-energy x-ray gamma-absorbtiometry (QDR-1000 W, Hologic, USA) was used to measure bone mineral density (BMD, g/cm2) and mineral content (BMC, g) in the whole body, the scalp including cervical vertebra, arms, ribs, sternal and lumbar regions of the spinal column, pelvis and legs. A clearly defined dependence of topography of changes upon the position of a skeletal segment in the gravity vector was established. The greatest BMD losses have been observed in the skeleton of the lower body, i.e. in pelvic bones (-11.99 +/- 1.22%), lumbar vertebra (-5.63 +/- 0.817%), and in proximal femur, particularly in the femoral neck (-8.17 +/- 1.24%). Bones of the upper skeleton were either unchanged (insignificant) or showed a positive trend. Overall changes in bone mass of the whole skeleton of male cosmonauts during the period of about 6 months on mission made up -1.41 +/- 0.406% and suggest the mean balance of calcium over flight equal to -227 +/- 62.8 mg/day. Reasoning is given to qualify these states of cosmonauts' bone tissues as local osteopenia. On the literature and results of authors' clinical evidence, discussed is availability of the densitometric data for predicting risk of trauma. A biological nature of the changes under observation is hypothesized.
In the nearly 15-month mission aboard MIR the cosmonaut-physician and members of three crews (MIR-15, -16, and -17) carried out a program of hematological investigations. Most of the changes related to the red blood system and included reduction in hemoglobin and hematocrit. Erythrocytes had decreased concentration and took on abnormal forms. There were also signs of altered metabolism of erythrocytes. Of interest are phase-by-phase variations in the levels of erythrocytes in the course of long-term stay in microgravity, and absence of a convincing correlation between hemoglobin, erythrocyte and hematocrit levels. But for lymphocytosis that returned to the norm already on the first day of recovery, no material changes occurred to the leukocyte profile. Investigations at the landing site displayed erythropenia, decreased reticulocytes and ensuing reticulocyte reaction, and gradual regain of the erythrocyte number that can be viewed as a normal physiological reaction of the blood system to the set of factors of spaceflight and early readaptation. Besides, the investigations showed a large individually of blood reactions to prolonged stay in space flight.
Experiment INTERSTITIUM was performed on days 3, 170, 287, and 430 of the long-term MIR mission of the Russian cosmonaut-physician in order to evaluate reactivity of the system of hormonal regulation of homeostasis during LBNP sessions. Data of the experiment displayed different types of reaction of the volume controls to LBNP at the onset (F-3), in the course of and soon after recovery (R-4) from the extended mission which are signs of specific phases of adaptive shifts in the organism of cosmonaut. Exaggerated reactivity of the hormonal systems during LBNP in flight suggests more significant consequences of the test for the cardiovascular system of human in microgravity. The most expressed hormonal reaction to LBNP was documented at the very beginning of the postflight period. Plasma cGMP was materially reduced in the process of the mission and remained quite low on R-4; return of nucleotides to the norm was observed no earlier than on R-90. Complete recovery from the space mission took three months when the hormonal reaction to LBNP was same as prior to launch.
Specificity of the use of ballistocardiography (BCG) in space flight is considered. In particular, the contactless method makes it possible to continue recording during the night hours and study the ultradian rhythms reflective of the state of higher autonomous centers. As was stated, on months 7 to 8 of the mission by cosmonaut-physician Polyakov the BCG amplitude rose in concert with activation of the higher autonomous centers that were apparently involved in maintaining the established cardiovascular homeostasis. By months 11 to 13 on mission, the BCG amplitude decline resulted in an increase in the SCG/BCG index representing the amount of myocardium energy spent on blood transport.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The authors' opinion that adaptation inhibition of erythron functioning under weightlessness produces an unfavourable effect on the optimal physical state of a cosmonaut and his working capacity in the post-flight period has been confirmed by the analysis of certain hematological parameters studied in cosmonauts. The data obtained have necessitated investigation of threshold values of erythron functioning under weightlessness, and creation of artificial gravitation on board the piloted space ship to normalize erythropoiesis. Investigation of these problems of space hematology would be helpful in validation of the limits of human's long-term stay under weightlessness, and in the pre- and post-flight period management.
A strategy of insulin treatment of mothers with diabetes mellitus at abdominal delivery has been developed. For the first 3 days after cesarean section, maternal glycemia was measured every 5 hrs and followed by simple short-acting insulin correction where necessary. On day 4-5 after resuming a normal diet (table No. 9), the puerperants were switched to long-acting insulin preparations. It was only by day 8-9 that the majority of the patients (87%) needed the same insulin dose as they used prior to the conception. This insulin regimen was used in 62 cases of abdominal delivery and prevented a decompensation of diabetes mellitus in all of those.
Results of hypnosuggestive treatment employed for women suffering from vomiting of pregnancy are discussed. In case of patient's consent the method works, but if any doubts of prejudices arise it fails. The main advantage of the method is a possibility to exclude or significantly reduce the damage of the fetus due to chemotherapeutic management of the condition.
The paper presents data of clinical and laboratory investigations performed in patients with vulvar leukoplakia or kraurosis before and after the helium-neon laser therapy. The impairment of adrenal performance (related to glucocorticoid, androgenic or mineralocorticoid functions) has been identified in the examinees. Employment of the laser therapy has normalized the impaired functions and beneficially affected local dystrophic processes in vulvar tissues. Local application of aerosol corticoid agents prolongs the response to the therapy.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.