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Biomedical subjects

K Morikawa

Publications and source records attributed to K Morikawa.

At least 361 records · Page 20Linked to original sources
PubMed1981

Restricted antibody formation to sheep erythrocytes of allogeneic bone marrow chimeras histoincompatible at the K end of the H-2 complex.

Employing a new method for allogeneic bone marrow transplantation, irradiation chimeras constructed from various combinations of marrow cells from B10 H-2 recombinant mice and AKR recipients were prepared. Though these chimeras had well-developed populations of T and B cells, they showed strikingly different patterns of responses in the primary antibody formation to sheep erythrocytes (SRBC), a T dependent antigen. These are (a) AKR mice treated with C57BL/10 cells, [B10 leads to AKR] fully H-2 incompatible, and AKR mice treated with B10.A (5R) cells, [5R leads to AKR] I-J,E compatible chimeras that were almost completely unresponsive to SRBC; (b) AKR mice treated with B10.BR cells [BR leads to AKR] fully H-2 compatible, and AKR mice treated with B10 AKM cells, [AKM leads to AKR] chimeras where donor and recipient differed only at H-2D, showed the same number of plaque-forming cells (PFC) as B10 control mice; (c) AKR mice treated with B10.A cells, [B10 leads to AKR] chimeras, where donor and recipient were matched at H-2K-I-E region, showed about one-half the number of PFC as the control mice. From these results we conclude that in allogeneic bone marrow chimeras primary antibody response to T-dependent antigen, such as SRBC, is generated when at least the K end of the H-2 complex is compatible between donor and recipient.

Animals↗
PubMed1981

Visualization of individual DNA molecules in solution by light microscopy: DAPI staining method.

A method was developed to visualize individual DNA molecules in solution under a fluorescent microscope connected to a highly sensitive video camera. DNA stained with a fluorescent dye, DAPI, revealed thin extended filaments, thicker filaments and rapidly transforming folded structures dependent upon the solution conditions. Structural transitions were observed and recorded as video images. Our observations indicated the possibility that DNA has the ability of supercoiling itself. This DAPI staining method will have wide possible application in the study of DNA and chromatin.

Amidines↗
PubMed1981

[Pharmacological studies on antispasmodics. IV. Ganglion blocking activity of 3-(di-2-thienylmethylene)-5-methyl-trans-quinolizidinium bromide (HSR-902) and the correlation between its blocking activity and its inhibitory activity towards urinary bladder contraction (author's transl)].

The ganglion blocking activity of HSR-902, a new antispasmodic agent, was compared with those of atropine sulfate, butylscopolamine bromide, timepidium bromide, prifinium bromide and hexamethonium chloride. These agents inhibited the postganglionic action potential induced by preganglionic cervical sympathetic nerve stimulation in cat and the order of potency was as follows: hexamethonium chloride much greater than timepidium bromide in equilibrium with butylscopolamine bromide greater than prifinium bromide greater than HSR-902 much greater than atropine sulfate. Moreover, the inhibitory activities were correlated with the inhibitory activities of these agents on urinary bladder contraction induced by pelvic nerve stimulation in cat which had been demonstrated in a previous report. On the nictitating membrane contraction induced by postganglionic cervical sympathetic nerve stimulation in cat, HSR-902 alone exhibited a slight inhibition. HSR-902, as well as tolazoline hydrochloride, an alpha-blocking agent, shifted the dose-response curve of noradrenaline-contraction in parallel to the right without decreasing maximal response in the isolated aorta of guinea pig, and the plots of Schild were found to be linear. These results suggested that the weak inhibitory activity of HSR-902 on urinary bladder contraction would be due to the weakness of its ganglion blocking activity and that it is a new antispasmodic agent with a slight alpha-blocking activity.

Action Potentials↗
PubMed1981

[Pharmacological studies on antispasmodics. V. Effect of 3-(di-2-thienylmethylene)-5-methyl-trans-quinolizidinium bromide (HSR-902) on the junctional transmission of pelvic nerve ending in isolated urinary bladder (author's transl)].

Effects of HSR-902, a new antispasmodic agent, on the junctional transmission of pelvic nerve ending in isolated urinary bladder was compared with those of atropine sulfate, butylscopolamine bromide, timepidium bromide and prifinium bromide. Tetrodotoxin (3 x 10(-8)g/ml) completely inhibited the contraction of isolated guinea pig urinary bladder induced by transmural stimulation (TM contraction), but hexamethonium chloride (1 x 10(-4)g/ml) and atropine sulfate (1 x 10(-5)g/ml) exhibited no inhibition and a slight inhibition, respectively. Neostigmine bromide (1 x 10(-7)g/ml) increased TM contraction, and the effect was completely inhibited by atropine sulfate (1 x 10(-5)g/ml). Antispasmodic agents (1 x 10(-7) - 1x 10(-5)g/ml), excluding HSR-902, showed slight inhibition on TM contraction. In contrast, HSR-902 (1 x 10(-6) - 1x10(-5)g/ml) increased TM contraction and/or resting tone (1 x 10(-5)g/ml). Phenoxybenzamine hydrochloride (1 x 10(-8)g/ml) and tolazoline hydrochloride (1 x 10(-5)g/ml), alpha-blocking agents, increased both TM contraction and resting tone. Increasing effects of HSR-902 on TM contraction and/or resting tone were completely inhibited by noradrenaline (1 x 10(-5)g/ml) with propranolol hydrochloride (1 x 10(-5)g/ml). These results suggested that these antispasmodic agents scarcely inhibited the junctional transmission in postganglionic cholinergic nerve ending induced by transmural stimulation of isolated guinea pig urinary bladder, and HSR-902 rather increased the transmission. Since it was also suggested that there was alpha-adrenoceptor inhibiting acetylcholine-release in the postganglionic cholinergic nerve terminal, the transmission increasing action of HSR-902 would be due to its alpha-blocking action.

Animals↗
PubMed1981

Failure of C3H mice to develop lung granuloma after intravenous injection of BCG cell wall vaccine. Demonstration of a defect in lymphoid cells.

C57Bl/6 (B6) mice produced highly developed granulomata in the lung 3 or 4 weeks after intravenous injection with oil-associated BCG cell walls (CW), but C3H/He (C3H) mice did not. The potential to develop granulomata is genetically controlled (Yamamoto & Kakinuma, 1978). It is probable that the genes control only T-cell mediated granuloma and not non-specific inflammation prior to onset of immunopathological response. The retention of an FITC-labelled BCG CW preparation in the lungs of B6 and C3H mice did not differ until 10 days after injection, although 24 hr uptake of 125 I-labelled BCG CW in B6 lung was twice as much as that in C3H lung. Furthermore, C3H mice did not show a secondary type granuloma response in the lungs after subsequent injections of BCG CW. In experiments using radiation chimaeras, B6 mice reconstituted with C3H bone marrow cells were unable to produce a granulomatous response to BCG CW. In contrast, C3H mice reconstituted with B6 bone marrow cells showed a good granulomatous response. These results suggest that the C3H mice possessed a deficiency within their lympho-haematopoietic cells.

Animals↗
PubMed1981

Specificity in the interaction of 4',6-diamidino-2-phenylindole with polynucleotides.

The binding of a fluorescent dye, 4',6-diamidino-2-phenylindole (DAPI) to polynucleotides was investigated by UV absorption and fluorescence spectroscopy. The results show that there are two types of bindings. In a higher concentration of DAPI, where UV spectroscopy is a suitable means for detecting the binding, the association of DAPI is independent of base compositions and the types of sugar moiety in spite of the spectral difference between DNA and RNA complexes with DAPI. On the other hand in a lower concentration of DAPI, where only fluorescence is measured to detect the binding, the degree of association is dependent upon the sugar types as well as base compositions.

Chemical Phenomena↗
PubMed1981

[Pharmacological studies of antispasmodics. III. Antispasmodic activity of 3-(di-2-thienylmethylene)-5-methyl-trans-quino-lizidinium bromide (HRS-902) on smooth muscle organs and its organ selectivity (author's transl)].

Pharmacological activities of HSR-902, a new antispasmodic agent, in gastrointestinal tract, biliary and urinary systems were compared with those of atropine, butylscopolamine bromide, timepidium bromide, prifinium bromide and diphemanil methylsulfate. In isolated smooth muscle organs (stomach, duodenum, ileum, colon, gall bladder and urinary bladder), anti-acetylcholine activities of HSR-902 were the most potent among these agents but its activity in urinary bladder, similar to findings in the cases of atropine and diphemanil methylsulfate, was relatively less potent than that of prifinium bromide, timepidium bromide and butylscopolamine bromide. Regarding the contractions of stomach, jejunum and ileum, which were induced by vagus nerve stimulation or acetylcholine, and on the ileum spontaneous motility, antispasmodic activities of HSR-902 were almost equal to or somewhat more potent than those of atropine, and its activities were more potent than those of prifinium bromide, timepidium bromide, diphemanil methylsulfate and butylscopolamine bromide. On the gall bladder pressure and the counts of perfusion through Oddi's Sphincter, these agents exhibited a similar inhibition and enhancement, respectively. In the case of urinary bladder contractions induced by pelvic nerve stimulation, these agents exhibited a weak inhibition. The inhibitory effect of HSR-902 was relatively less potent than that of other agents except atropine, which had little effect. HSR-902 was similar to atropine in this so-called "atropine-resistance".

Acetylcholine↗
PubMed1978

Crystallization of arginine-, formylmethionine-tyrosine-, and glycine-transfer RNAs from Escherichia coli.

Crystals as large as 0.5 X 0.3 X 0.2 mm of purified arginine-transfer RNA from Escherichia coli have been prepared by a vapour diffusion method. X-ray diffraction photographs showed that the crystals gave reflections up to 3.7 A spacing. They have a trigonal space group P31 2 1 (OR P32 2 1) and cell-dimensions a=97.2, b=97.2, c=94.8A. Crystals of a mercury derivative of this transfer RNA have also been obtained, and an X-ray diffusion photography of one of them is presented. Formylmethionine-transfer RNA from E. coli was crystallized in various forms, and the appearance of the polymorphs was found to depend upon the amount of spermine in the solution from which the crystallization took place. Crystals of tyrosine-transfer RNA and glycine-transfer RNA have also been obtained.

Arginine↗