Dynamic changes in the reactivity of the hormonal system regulation with the impact by LBNP sessions in long-term space mission

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.     

Effect of solvent structure on amide reaction with native DNA molecules. II. Aqueous acetamide mixtures

The influence of acetamide (AA) on the native DNA molecule conformation has been studied by methods of flow birefringence and viscometry. On one hand, it was shown that hydrodynamical and optical behaviour of the macromolecule at extremely low additions of AA is qualitatively the same as in the presence of nonelectrolytes which stabilize the water structure. On the other hand, the influence of intermediate and large AA concentrations on the native DNA molecule conformation is qualitatively the same as of corresponding urea concentrations, which is known to be a structure-breaker. The influence of AA on the thermostability of the native DNA molecule as well as on the stacking-association constant of adenosine has been studied by a spectrophotometric method. The obtained data confirm the hypothesis of the importance of ion-dipole interactions between nonelectrolytes and the phosphate groups of the DNA molecule.     

Studies on the functional ability of swine liver perfused with human blood in machine recirculation attempt. Experiment design, elimination of indocyanine green, galactose, bilirubin and ammonia, synthesis of urea, bile secretion

In 11 machine experiments of recirculation the abilities of survival and functioning of livers of dwarf pigs perfused with human preserved blood were tested with the help of the eliminations of indocyanine green, galactose, bilirubin and ammonia from a closed circulation. Further urea-nitrogen were measured as indicator of the urea synthesis and bile secretion. The perfusion of the animal livers was carried out in 9 cases only through the portal vein. The values of the blood flow were between 0.4 and 1.0ml pro g liver tissue and minute in portal pressure values about 15 cm water column. Two recirculations were carried out with additional flow through the hepatic artery with about 1/5 of the whole blood flow. The results of the experiments described prove a pretty good functional performance of the perfused with human blood livers of dwarf pigs during several hours. The different animal livers, however, showed at the beginning as well as during the further course of the perfusion clear differences concerning their functional capacity. Decrease of the blood flow values below 0.5 ml pro g liver tissue lead to functional loss. The additional flow through the hepatic artery yielded no better results, compared with the only perfusion of the animal liver through the portal vein.     

Post-traumatic middle cerebral artery occlusion: case report and review

Occlusion of extracranial carotid and vertebral arteries following closed craniocervical trauma is well known. However occlusion of intracranial arteries following closed head injuries is infrequently reported. In fact only 25 cases of post-traumatic middle cerebral artery occlusion have been adequately documented. This entity bears re-emphasis not only because of its rarity but also because of its clinical similarity to other intracranial mass lesions.     

Increased dependence on visual information for movement control in patients with Parkinson's disease

Studies were made of visually and non-visually guided movements by patients with Parkinson's disease. The subjects moved a light, horizontal handle using rotation primarily about the elbow. During visually guided trials both handle and target positions were displayed to the subject; during non-visually guided trials only the handle position was displayed. During non-visually guided trials all patients showed a tendency for an overall flexion drift, although there was no change in average movement amplitude. The overall error in position by the end of the non-visually guided trials was greatly in excess of the reported values for passive displacement thresholds in normal subjects. It is suggested that the data indicate an increased dependence on visual information for control of motor activity in Parkinson's patients.