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Biomedical subjects

K Matsuno

Publications and source records attributed to K Matsuno.

At least 343 records · Page 19Linked to original sources
PubMed1980

Compartmentalization of self-reproducing machineries: multiplication of microsystems with self-instructing polymerization of amino acids.

A theoretical model is presented for the self-instructing polymerization of free amino acids which proceeds inside microsystems which are phase-separated from the solution of thermal polyamino acids. It is shown theoretically that a compartmentalized microsystem fixes inside itself only the process with a faster macromolecular multiplication as time passes, even if the catalytic polymerization alone could spontaneously decrease the corresponding reaction rate. The compartmentalized machinery of macromolecular multiplication cannot reach its stationary state. The machinery is inevitably multiplied and alternates with those with either faster rates of macromolecular multiplication or slower rates of macromolecular degradation during their time development. These results are based upon the dynamic process that any material system acts by itself so as to remove any flow disequilibrium, that is, to maintain the continuity of material flow.

Amino Acids↗
PubMed1980

Operational description of microsystems formation in prebiological molecular evolution.

A theoretical analogue of microsystems formation in prebiological molecular evolution, known, for instance, as microspheres of Fox and marigranules of Yanagawa and Egami, is presented for a model solution system of polyamino acids in which the polymerization due to peptide bond synthesis is initially not in a complete balance with the hydrolysis. The homogeneous solution of polyamino acids, which is in a nonequilibrium state in the sense that a complete balance among all the participating reactions has not yet been established, is unstable against forming microscopic compartments of locally condensed peptide bond linkages. It also follows that both the accumulation of polyamino acids and the number of peptide bond linkages inside the localized microsystems increase with time so long as the solution remains in a nonequilibrium state lacking the balance between the polymerization and the hydrolysis. The phase separation of microsystems from the homogeneous solution of polyamino acids is just a representation of the unidirectional dynamic process that any reaction system, which initially lacks a complete balance among all the participating reactions, evolves toward a goal, if any, at which an equilibrium balancing of reactions be finally established.

Biological Evolution↗
PubMed1980

Suppression of immune response by isolation of the bursa of Fabricius from environmental stimuli.

When the bursa of Fabricius was isolated from environmental stimuli across the bursal epithelium by clipping the bursal duct on the 19th day of incubation, marked retardation was observed both in the bursal development and in the maturation of the immune reactivity. Neither necrotic changes nor involution in the bursa was, however, observed at any stage examined after clipping the bursal duct. Lymphopoiesis in the bursa and the immune reactivity of these chickens gradually increased with age, although they were constantly lower than those of controls. These results suggest that environmental stimuli across the bursal epithelium play an important role in teh amplification mechanisms of B-cell differentiation in the bursa.

Animals↗
PubMed1980

The increase in permeability of postcapillary venules in lymph nodes subjected to the regional graft-versus-host reaction.

The changes in permeability of blood vessels in the draining lymph nodes of the footpads undergoing a regional graft-versus-host, host-versus-graft, or antisheep erythrocytes reaction were examined 30 minutes after intravenous injection of Pelikan Ink. Massive leakage of carbon particles was seen only in the postcapillary venules where endothelial cells became flattened. This was observed in lymph nodes 3 to 7 days after induction of the regional graft-versus-host reaction and occurred mainly through intercellular gaps in the endothelium. This transient increase in permeability of postcapillary venules was apparently independent of cellular emigration. No obvious increase in carbon permeability was observed in lymph nodes subjected to the regional host-versus-graft reaction, whereas the uptake of cellular and noncellular elements of the blood by endothelial cells of postcapillary venules was greatly increased. There was no increase in carbon permeability in antisheep erythrocyte-stimulated lymph nodes.

Animals↗
PubMed1979

Peritoneal macrophages introduced into mouse foot pads enter the germinal center of regional lymph nodes nonspecifically.

Male mice were injected into their foot pads with sheep erythrocytes (SRBC) to form lymph follicles in the germinal centers in the popliteal lymph nodes. 4 weeks later, peritoneal macrophages labeled with carbon from syngeneic donors sensitized with SRBC or typhoid-paratyphoid bacilli (TAB) were separately injected into the foot pads as well. The popliteal lymph nodes were histologically examined at 6 h to 5 days after injection. Labeled macrophages appeared in the marginal sinus, migrated straight across the cortex from the marginal sinus to the lymph follicles and then entered the germinal centers. There was no difference in the mode of appearance, migration and localization of labeled macrophages in the regional lymph nodes between the mice given labeled macrophages from SRBC-sensitized donors and those given macrophages from TAB-sensitized donors. The entrance of lymph macrophages into the germinal centers of the regional lymph nodes would be immunologically nonspecific. After the injection of Pelikan ink into the foot pads, the macrophages which have taken up carbon in the peripheral tissue reached the regional lymph nodes via the afferent lymphatics and then entered the germinal centers, mainly through the medullary pole of the lymph follicles, after migrating along their immediate exterior from their marginal sinus to their medullary pole.

Animals↗
PubMed1979

Effects of estrogen on the lymphoid regeneration and immune response in irradiated and marrow-reconstituted mice.

Various doses of estriol (E3) were given to mice intraperitoneally, immediately after lethal irradiation and marrow reconstitution. The assessment of the plaque-forming cell (PFC) response to sheep erythrocytes in the spleen and the histological assessment of lymphoid tissues were carried out 30 days later. The effects appeared to be dose-dependent and resulted in a marked suppression of the PFC response. The depletion of lymphocytes was dramatic and dose-dependent in the thymus, and in the thymus-dependent and in the thymus independent areas of the peripheral lymphoid tissues. These results suggest that E3 acts on the differentiation of stem or precursor cells toweard both the populations of T and B lymphocytes. Although E3, given on day 7 after irradiation and marrow reconstitution, suppressed the lymphoid regeneration and PFC response markedly, E3 given on day 14 had no effect. On day 7 the majority of regenerating lymphoid tissues were large pyroninophilic cells and on day 14, small lymphocytes. These results suggest that the precursor or immature lymphocytes are sensitive to E3, while mature lymphocytes are resistant. Lymphoid regeneration and PFC response were retarded in mice irradiated and reconstituted with bone marrow cells from donors pretreated with E3. These results suggest that E3 acts on the stem or precursor cells capable to differentiate in the direction of lymphoid populations and reduce their number in the bone marrow.

Animals↗