Information processing in the human brain: magnetoencephalographic approach

Rapid progress in effective methods to image brain functions has revolutionized neuroscience. It is now possible to study noninvasively in humans neural processes that were previously only accessible in experimental animals and in brain-injured patients. In this endeavor, positron emission tomography has been the leader, but the superconducting quantum interference device-based magnetoencephalography (MEG) is gaining a firm role, too. With the advent of instruments covering the whole scalp, MEG, typically with 5-mm spatial and 1-ms temporal resolution, allows neuroscientists to track cortical functions accurately in time and space. We present five representative examples of recent MEG studies in our laboratory that demonstrate the usefulness of whole-head magnetoencephalography in investigations of spatiotemporal dynamics of cortical signal processing.     

Evolution of surface activity related functions of vertebrate pulmonary surfactant

1. Pulmonary surfactant is a mixture of lipids and proteins that lines the air-liquid interface of the lungs of all vertebrates. In mammals, it functions to reduce and vary surface tension, which helps to decrease the work of breathing, provide alveolar stability and prevent alveolar oedema. The present review examines the evolution and relative importance of these surface activity related functions in the lungs of vertebrates. 2. The surface activity of surfactant from fish, amphibians, birds and most reptiles is generally very low, correlating with a low body temperature and a low disaturated phosholipid content of their surfactant. In contrast, the surfactant of those reptiles with a higher preferred body temperature, as well as that of birds and mammals, has a much higher surface activity. 3. The two main functions of surfactant in mammals are to provide alveolar stability and to increase compliance of the relatively stiff bronchoalveolar lung. As the respiratory units of most non-mammalian vertebrates are up to 1000-fold larger and up to 100-fold more compliant, surfactant is not required for these functions. 4. In non-mammals, surfactant appears to act as an anti-glue preventing the adhesion of respiratory surfaces that may occur when the lungs collapse (e.g. during diving, swallowing of prey or on expiration). Surfactant also controls lung fluid balance. These functions can be fulfilled by a surfactant with relatively low surface activity and may represent the primitive functions of surface active material in vertebrate lungs.     

Pulse therapy with prospidin and methotrexate: comparative efficacy in rheumatoid arthritis (12-month controlled study)

Efficiency of pulse-therapy with prospidin (500 mg for 5 days in hospital, 500-1000 mg for a month as maintenance) and methotrexate (30 mg a week i.v. in hospital, 7-10 mg a week as maintenance) was investigated in 93 patients with severe RA. The response to prospidin and methotrexate arose quickly (within 10-14 and 4-5 weeks, respectively) and occurred in 73 and 70% of patients, respectively. Withdrawal of the drug was caused by side effects of methotrexate (19.3%) and resistance to prospidin (23.2%).     

Effect of H+ extracellular and intracellular buffering capacity on the activity Ca2+/H+ exchange in the lymphocyte plasma membrane

Formation of delta pH is registered when studying Ca2+ passive transport through lymphocytes' plasma membrane (PM). The pHi values strongly depended on pH0. Changes of pH0 lead to unidirectional changes of pHi and affect Ca2+ concentration in cytoplasm of the intact cells. The presence of Ca(2+)-channels antagonists does not affect this phenomenon. Ca2+/H+ exchange is supposed to exist in PM. It is also of great interest that cytoplasmic Ca2+ and H+ activities are some equal in physiological range. Besides, H(+)-buffering as well as Ca(2+)-buffering systems are present in the cell and have their maximal capacity about 7.2 in the intact cells. The spectrofluorimetric study of internal lymphocytes' H(+)-buffering capacity with titration technique using weak base, acid or other buffer addition has demonstrated maximal value of 9.0-1.1 mM depending on the substance to be added.     

Treatment of patients with failed sutures in the small intestine

The suture insufficiency have occurred in 26 (15%) patients after operative treatment of 179 patients with different diseases of small intestine. The main methods of treatment of this patients are the surgical procedures, intestinal intubation, rational antibioticotherapy, the hemostasis correction for the postoperative peritonitis liquidation.     

Spatial association of prekinetochores and chromocentres in the interphase nuclei of mouse cultured fibroblasts

The literature has been reviewed to evaluate the technique and clinical value of radionuclide measurements of microvascular permeability and oedema formation in the lungs. Methodology, modelling and interpretation vary widely among studies. Nevertheless, most studies agree on the fact that the measurement of permeability via pulmonary radioactivity measurements of intravenously injected radiolabelled proteins versus that in the blood pool, the so-called pulmonary protein transport rate (PTR), can assist the clinician in discriminating between permeability oedema of the lungs associated with the adult respiratory distress syndrome (ARDS) and oedema caused by an increased filtration pressure, for instance in the course of cardiac disease, i.e. pressure-induced pulmonary oedema. Some of the techniques used to measure PTR are also able to detect subclinical forms of lung microvascular injury not yet complicated by permeability oedema. This may occur after cardiopulmonary bypass and major vascular surgery, for instance. By paralleling the clinical severity and course of the ARDS, the PTR method may also serve as a tool to evaluate new therapies for the syndrome. Taken together, the currently available radionuclide methods, which are applicable at the bedside in the intensive care unit, may provide a gold standard for detecting minor and major forms of acute microvascular lung injury, and for evaluating the severity, course and response to treatment.     

Structure of 5S rRNA within the Escherichia coli ribosome: iodine-induced cleavage patterns of phosphorothioate derivatives

The protection patterns of 5S rRNA in solution, within the ribosomal 50S subunit, 70S ribosomes, and functional complexes, were assessed with the phosphorothioate method. About 20% of the analyzed positions (G9-G107) showed strong assembly defects: A phosphorothioate at one of these positions significantly impaired the incorporation of 5S rRNA into 50S particles. The reverse has also been observed: A phosphorothioate is preferred over a phosphate residue in the assembly process at a few positions. The results further demonstrate that 5S rRNA undergoes conformational changes during the assembly in the central protuberance of the 50S subunit and upon association with the small ribosomal subunit forming a 70S ribosome. In striking contrast, when the 70S ribosomes are once formed, the contact pattern of the 5S rRNA is the same in various functional states such as initiation-like complexes and pre- and posttranslocational states.     

Domestication as a possible mode of biodiversity conservation (as exemplified by the river otter Lutra lutra L., 1758)

On an experimental basis in the Institute of Cytology and Genetics Siberian Division, Russian Academy of Sciences, a cage population of river otter (Lutra lutra) was formed. During the introduction period of captivity, as the selection for stress resistance in an anthropogenic environment is shown to be a crucial factor. Through the course of domesticating river otters, directional selection occurs due to the increase in the number of individual otters and to the absence of fear-induced response toward humans. In the initial generation caught in the wild, three types of animals were revealed: cowardly or showing a fear-induced response (80%), aggressive (10%), and quiet (10%). After three generations were reared in captivity, the relationship between these three phenotypes changed in favor of otters with a quiet response toward man; the percentage increased. After three generations, these quiet animals comprised 37%. The percentages of aggressive and cowardly animals accounted for 11 and 52%, respectively.     

A study of the effect of the adsorbed molecules of concanavalin A on characteristics of the bound water in the hydrate coat of the disperse silica by 1H NMR of the frozen water suspensions

The experimental technique is presented which allows the investigation of water at the adsorbent-biopolymer interface by record of temperature dependencies of 1H NMR signals during the heating of previously frozen water suspensions. It was found that the adsorption of protein conconovalin A resulted in twofold decrease of strong bound water amount and in 70% increase of loosely bound one. The mean-value of Gibbs energy decreased twice for strong bound water and increased twice for loosely bound one. The external layer of hydrate shell of silica particles with adsorbed conconovalin A was organized by protein molecules. This conclusion is based on the observed total increase of loosely bound water amount, as a result, of protein adsorption, although its amount with respect to a protein molecule decreased.