Reactions of the cardio-respiratory system of cosmonauts to dosed physical loads following 30- and 63-day flights in orbital station "Salyut-4"

Cardiorespiratory responses of Salyut-4 crewmembers to exercises of 600 kgm/min performed for 7 min on a bicycle ergometer in the supine position were studied. It was found that the 30- and 63-day flights induced a certain decrease in the body response which included a less economic functioning of the cardiorespiratory system during exercise. The degree of postflight changes of the 30- and 63-day crewmembers was similar. At the same time the cardiorespiratory system of the 63-day crewmembers returned to the preflight level more rapidly than that of the 30-day cosmonauts.     

Application of the one-dimensional Ising model to the secondary structures in globular proteins. Prediction of beta-regions

An attempt has been made to predict the beta-regions in 16 globular proteins by applying the one-dimensional Ising model theory of Lifson & Roig (8). The parameters for the theory have been derived from the statistical data on globular proteins given by Chou & Fasman (5). Comparison of our results with the data available from the X-ray crystallographic studies indicates a prediction accuracy which is comparable to those of several other methods, especially in view of the limitations in our method for considering the other secondary structures. It is pointed out that not considering the long-range interactions in our and other methods based on short-range interactions would make these methods incomplete and incapable of being uniformly applicable to all proteins.     

Antibodies of oncornaviruses and virus-associated antigens in cancer patients

Specific antibodies to oncornaviruses type D and to induced by them new virus-associated antigens were found by the CFT and the adsorption method in 72.4% of 29 tested sera from patients with gynecological cancer and sarcoma and in 62.5% of 72 sera from patients with benign tumours of the genitalia. At the same time, similar antibodies were found in 73% of 63 sera from healthy donors with the blood group O.     

Pathways regulating cardiovascular changes during volume loading in awake dogs

The role played by the cardiac sympathetic nerves and arterial baroreceptors in the cardiovascular responses to acute volume loading was studied in conscious dogs. In 15 normally innervated animals, mean arterial pressure rose 10 mmHg, heart rate increased 38 beats/min and cardiac output 1,696 ml/min, while peripheral resistance decreased 0.99 PRU. Neither bilateral baroreceptor denervation, dorsal root sections (T1-T5) or surgical interruption of the left ansa subclavia altered the above responses to acute volume loading. Bilateral section of the ansa subclavia (total cardiac sympathectomy) significantly reduced the heart rate response from 35 +/- 5 to 20 +/- 5 beats/min but did not alter other changes. A similar reduction in heart rate response was observed following selective section of the right ansa subclavia. Intravenous infusions of epinephrine augmented the heart rate response in both normally innervated and cardiac sympathectomized dogs. It is suggested that although the primary efferent pathway for the reflex trachycardia is via the vagus, responses are modulated by sympathetic neural activity. Additionally, the nervous system was not shown to play a measureable role in the observed peripheral resistance changes.     

Quantitative description of the process of radiation inactivation of cells. VIII. Microdosimetry in the analysis of the reproductive death of eukaryotic cells

The microdosimetric approach permits to model the first physical stage of radiation damage developing of multistage model of radiation effect. It describes stochastics of absorbed energy distribution among and inside sensitive cell volumes. The analysis of radiobiological effect becoming more complete and adequate. The limits of application of valuable microdosimetric values to characterizing both the quality and quantity of radiation affecting the cells is considered. The aspects of the theory of dual action of radiation well compare with those of the cytogenetic model linking the reproductive cell death with asymmetrical chromosome exchanges.