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Biomedical subjects

K Matsuno

Publications and source records attributed to K Matsuno.

At least 325 records · Page 18Linked to original sources
PubMed1983

[Field tests of a new passive personal monitor for organic vapors].

The method making use of a New Du Pont PRO-TEKTM G-AA Organic Vapor Air Monitoring Badge, was applied to evaluate the concentration of organic vapor in a working atmosphere. Other methods such as the direct air sampling method and the method of adsorption on charcoal tube were compared with the above mentioned method. In the comparative study of these methods in working places, similar results were obtained by the new badge method and the charcoal tube method, though different results were obtained between the direct air sampling method and the mentioned two methods. The differences may have resulted from the period needed for the sampling, that is, an intermittent sampling was generally used for the direct sampling method. In a study of personal exposure monitoring by the badge method and the tube method, the results obtained by the badge method were lower than those obtained by the latter method suggesting the effects of the response of the badge on organic vapor in working places. The relationships between the instantaneous changes of the concentration of organic vapor in the atmosphere and the response time of the badge will be discussed elsewhere.

Air Pollutants↗
PubMed1983

Further studies on the effects of flavine adenine dinucleotide on the platelet functions.

Flavine adenine dinucleotide (FAD) may inhibit not only the aggregation but also ATP release of platelets in vitro. FAD did not inhibit the synthesis of thromboxane from 1-14C-arachidonic acid by platelets. FAD was found to be hydrolyzed to FMN and AMP by a plasma enzyme, the activity of which in normal adults being estimated as 32.6 +/- 9.1 m microM/ml plasma/min and AMP, thus produced, and/or FAD might compete for the receptor sites on the platelet surface. This could be the mechanism of the inhibitory effect of FAD upon the platelet functions. The intravenous drip infusion of FAD in a dose of 0.2 mg/kg within 30 min was followed by no marked decrease of platelet aggregation, probably because the plasma concentration of FAD and/or AMP did not reach the levels high enough to suppress the platelet functions.

Adenosine Triphosphate↗
PubMed1983

Uptake by enterocytes and subsequent translocation to internal organs, eg, the thymus, of Percoll microspheres administered per os to suckling mice.

The translocation of Percoll microspheres (mean diameter 20-30 nm) from the intestinal lumen through the epithelial layer to internal organs was examined in suckling mice using transmission electron microscopy. Repeated administration of this material by gavaging for 7 consecutive days resulted in a heavy particle load of vacuolated enterocytes. A limited amount of Percoll was transported to the subepithelial tissue of both the villous mucosa and Peyer's patches where microspheres were found endocytosed, predominantly by macrophages. Even smaller numbers of particles reached mesenteric lymph nodes and, occasionally, milky spots of the omentum. Minor Percoll aggregates were easily found in Kupffer cells of the liver, indicating hematogenous translocation. Small numbers of particles were regularly detected in perivascular macrophages of the thymic cortex, which are in close contact with surrounding lymphocytes. We conclude that the thymic cortex is not totally inaccessible to particulate matter of the intestinal content.

Animals↗
PubMed1983

[Pharmacological actions of eptazocine (l-1,4-dimethyl-10-hydroxy-2,3,4,5,6,7-hexahydro-1,6-methano-1,H-4-benzazonine). 4. Antagonistic action of naloxone on eptazocine analgesia].

It was investigated whether the analgesic effects of eptazocine were antagonized by treatment with naloxone, one of the opiate antagonists, and whether morphine-induced effects were affected by eptazocine. The analgesic effects of eptazocine, similar to those of morphine, were completely antagonized by treatment with 0.5 mg/kg naloxone, s.c., as determined by the hot plate and pressure methods in mice and by the tail-flick method in rats. In contrast, as tested by the acetic acid-induced writhing method in mice, the analgesic effect of eptazocine, similar to that of pentazocine, was not antagonized by treatment with 1.0 mg/kg naloxone, s.c., while that of morphine was antagonized by 0.5 mg/kg naloxone, s.c. Using the acetic acid-induced writhing method in mice, the pA2 values of naloxone were found to be the following order: eptazocine less than pentazocine less than morphine. In addition, the analgesic effect of morphine was dose-dependently antagonized by the treatment with eptazocine as determined by the pressure method. Furthermore, the stimulating effect of morphine on spontaneous locomotor activity was also antagonized by eptazocine. These results suggest that eptazocine may be classified as one of the opiate agonist-antagonists.

Analgesics↗
PubMed1982

Natural self-organization of polynucleotides and polypeptides in protobiogenesis: appearance of a protohypercycle.

Basic thermal polyamino acids or proteinoids have been reported to be catalytic for both self-instructing polymerization of amino acids and internucleotide synthesis. We show theoretically that a complex suspension of thermal proteinoids, free amino acids, nucleotides and ATP as an energy source can exhibit an evolutionary character. The suspension can produce a prototype of Eigen's hypercycle, or protohypercycle, for which translation proceeds from amino acid to nucleotide. The protohypercycle is suggested to be an evolutionary precursor of the hypercycle, in which translation is from nucleotide to amino acid. The possibility that the Fox-Nakashima microsphere containing both lysine-rich and acidic proteinoids may work as a model of a protohypercycle is considered.

Adenosine Triphosphate↗
PubMed1981

Material self-assembly as a physicochemical process.

Material self-assembly as exemplified in protobiogeneses is shown to be result of molecular exchange interaction in reacting chemicals. Temporally and spatially correlated aggregates of reacting chemicals work as vertices of molecular exchange interaction. If the material accumulation rate at a locally correlated aggregate spontaneously happens to become positive at a certain time, the material accumulation due to self-assembly will increase with time afterward. A spontaneous formation of looped reaction at locally correlated aggregates of reacting chemicals can initiate a material self-assembly at succeeding times.

Mathematics↗
PubMed1981

Self-sustaining multiplication and reproduction of microsystems in protobiogenesis.

The appearance of reproducing microsystems during stimulated protobiogenesis is investigated theoretically, based upon the observation that proteinoid microsystems, which are local aggregates of reacting chemicals, act as reaction nodes. Further splitting of such nodes follows if sufficient growth takes place. Parent-connected daughter nodes thus appear. A parent-connected daughter node rejuvenates itself while its parent node survives, although an extinction of the latter is inevitable in the presence of spontaneous disturbances. The degree of rejuvenation is measured in terms of the molecule intake and dissociation rates at the node. A daughter node grows and matures after the extinction of its parent, and gives rise to second-generation nodes when it grows sufficiently large. The parent node alternates with its parent-connected daughter nodes successively.

Mathematics↗