Search PubMed⌕ Search

Biomedical subjects

H Usui

Publications and source records attributed to H Usui.

At least 181 records · Page 10Linked to original sources
PubMed1982

Influence of trimetazidine, an antianginal drug, on isolated dog arteries and veins.

In helical strips of dog coronary, mesenteric, renal, femoral and basilar arteries contracted with prostaglandin F2 alpha, trimetazidine produced a dose-related relaxation, which was not influenced by treatment with propranolol, atropine, cimetidine, aminophylline and aspirin. Relaxations induced by trimetazidine of strips of large and small coronary arteries did not differ, while those of large artery strips induced by nitroglycerin were significantly greater. Mesenteric vein strips responded with a greater relaxation to trimetazidine than mesenteric artery strips, while the vein and artery strips relaxed in response to nitroglycerin to a similar extent. Contractile responses to transmural stimulation and norepinephrine of mesenteric vein strips were attenuated by trimetazidine to a greater extent than those of artery strips. However, trimetazidine did not protect alpha-adrenoceptors from persistent blockade by phenoxybenzamine. Treatment with high concentrations of trimetazidine attenuated the relaxant response to isoproterenol of coronary arteries and the contractile response to Ca++ of the arteries exposed to Ca++-free media and depolarized by excess K+. It may be concluded that trimetazidine preferentially relaxes venous muscle and reduces contractile responses of veins to activation of sympathetic nerves, thereby reducing venous return or preload of the heart.

Animals↗
PubMed1982

Synthesis of carbon-bridged pyrimidine cyclonucleosides.

6,5'-Cyclo-5'-deoxyuridine 2',3'-cyclic phosphate and its derivatives were prepared as the conformationally fixed substrates of pancreatic ribonuclease. 6,6'-Cyclouridine, 6,3'-methylene-cyclo-2', 3'-dideoxyuridine, and 6,2'-ethylene-cyclo-2'-dexoyuridine were prepared as the new types of C-cyclopyrimidine nucleosides fixed in the anti conformation. The relationship between the sign and magnitude of CD Cotton bands and glycosylic torsion angles is discussed.

Animals↗
PubMed1981

Multiple angiitis of mesenterial arteries in guinea pigs induced by intraperitoneal administration high doses of Na2EDTA. I. Light microscopic study.

In this experiment multiple angiitis in various phases was demonstrated after intraperitoneal administration of high doses of Na2EDTA. These vascular manifestations induced by hyperexudation may probably be provoked by the loosening of the vascular wall which was caused by the releasing of calcium ions from its structure. In addition to its functional importance, such as muscular contraction, nerve transmission and the cell junction, the calcium ion is more important for the alteration of the molecular structure of acid mucopolysaccharides. Intraperitoneal administration of high doses of Na2 EDTA resulted in dissociation of hte intermuscular spaces with endothelial cell reaction. The metamorphosis of the vascular muscle cells into spindle shaped one could also be demonstrated. The hyperexudation caused by the above procedures induced angiitis-like lesions with round cell infiltration.

Animals↗
PubMed1981

Multiple angiitis of mesenterial arteries in guinea pigs induced by intraperitoneal administration of high doses of Na2 EDTA. II. Electron microscopic study.

By application of high doses of EDTA we could induce angiitis-like lesions in the mesenterial arteries. In this paper we report the findings of electronmicroscopic investigations of these lesions. They consist of dissociation of the smooth muscle cells by scanty intermuscular spaces, probably by loosening of the basal laminae and matrix. Both endothelial cells and smooth muscle cells show minimal changes. The elastic lamellae were partially interrupted.

Animals↗
PubMed1981

Pulmonary fibrosis of low calcium diet fed guinea pigs induced by the administration of a soluble immune complex.

Feeding animals a low calcium diet leads to lymphangiectasis of peribronchial lymphatic vessels, sometimes followed by overflow of lymphatic fluid into the surrounding tissue. Adding a soluble immune complex (SIC) to the diet, the peculiar diffuse interstitial pneumonia and finally pulmonary fibrosis were noted. Small honey-combed structures and sometimes histologic accommodation of epithelial lining cells were observed. Sometimes accumulation of leucocytes within honey-combed structures was seen.

Animals↗
PubMed1981

Reconstitution of urea-dissociated subunits of a pig heart phosphoprotein phosphatase.

Pig heart phosphoprotein phosphatase [phosphoprotein phosphophydrolase, EC 3.1.3.16] of Mr 224,000 was dissociated by gel-filtration on Sephacryl S-300, into an active subunit (alpha subunit) of Mr 31,000 and inactive subunits of higher molecular weight in the presence of 6 M urea. After the removal of urea, these subunits reassociated, forming two enzyme forms of Mr 237,000 (Form 1) and Mr 123,000 (Form 2). Form 2 was produced by association of the alpha subunit with an inactive subunit (beta subunit) of Mr 80,000, while Form 1 was formed by combination of the alpha subunit with a complex of inactive subunits which was eluted from a Sephadex G-150 column in fractions of molecular weight range greater than 80,000. The dissociation and reassociation of the subunits of Form 1 by the same urea method produced not only Form 1, but also significant amounts of Form 2, indicating that the inactive subunits of Form 1 were a complex of the beta subunit with another inactive subunit(s). The molecular parameters and other properties of Form 1 were very close to those of the original enzyme. By the conversion of Form 1 to Form 2, the activities of Form 1 towards phosphorylase a and glycogen synthetase b were enhanced 2-3 fold with no significant change in activity towards P-H1 histone or in response to the stimulatory effect of Mg(CH3COO)2 on the dephosphorylation of P-H2B histone. However, removal of the beta subunit from From 2 resulted in strong suppression of activity towards P-H1 histone and response to the salt effect with lesser effects on the activities of Form 2 towards phosphorylase a and glycogen synthase b.

Animals↗
PubMed1981

[Clinical application of cefsulodin to Pseudomonas aeruginosa infections in the surgical field (author's transl)].

Cefsulodin (CFS), a new antipseudomonas cephalosporin, was clinically evaluated for treatment of the Pseudomonas aeruginosa infections in the surgical field to obtain the following results. 1. CFS was administered to total 11 cases of the surgical infections caused by P. aeruginosa, comprising of 5 cases with wound infections, 3 cases with infected burn and 1 case each with muscular abscess, decubitus and postoperative pneumonia in 0.5 approximately 1 g twice a day by intravenous bolus or drip infusion. Good clinical responses were obtained in 9 out of 11 cases (81.8%). 2. Bacteriological responses were observed in all cases. P. aeruginosa was eradicated in 9 cases and suppressed in 2 cases by CFS treatment. However, replacement of pathogens with the other organisms was observed in 6 out of 8 cases caused by P. aeruginosa only. 3. Neither objective and subjective side effects nor abnormalities of laboratory tests associated with CFS treatment were observed. 4. It can be, therefore, concluded that CFS is one of the useful drugs for treatment of the surgical infections caused by P. aeruginosa.

Adult↗
PubMed1980

Isolation of an inactive component from pig heart phosphoprotein phosphatase and its reassociation with an active component.

Treatment of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16) of Mr 224 000 with 40% ethanol followed by gel-filtration on Sephadex G-150, dissociated the enzyme into an active component of Mr 31 000 and an inactive component of Mr 80 000. The inactive component reassociated with the active component, resulting in the formation of an enzyme form of Mr 123 000. A large excess of either component in the reassociation produced only this enzyme form. The ability of the inactive component to associate with the active component was lost by treatment of the inactive component with trypsin and heat (60 degrees C, 2 min) but not with DNAase and RNAase. Effects of the inactive component on the activities of the active component by the association were as followings. The inactive component: (1) stimulated slightly the 32P-H2B histone phosphatase activity in the presence of either NaCl or Mg(CH3COO)2 but inhibited strongly in the absence of the salts; (2) stimulated the 32P-H1 histone phosphatase activity in the presence of the salts; (3) inhibited the phosphorylase a phosphatase activity in the presence and absence of the salts; (4) enhanced the response to the stimulatory effects of the salts on the dephosphorylation of 32P-histone; and (5) protected the phosphorylase a phosphatase activity from inhibition by the salts.

Animals↗
PubMed1979

The control of phosphoprotein phosphatase by the second-site phosphorylation of a substrate. Studies with H2B histone as model substrate.

The phosphorylation of Ser-32, in addition to Ser-36 of H2B histone, stimulated the rate of Pi release from Ser-36 by the small form (Mr 31 000) of pig heart phosphoprotein phosphatase both in the absence and presence of 50 mM magnesium acetate. By phosphorylation at Ser-32, the Km value for Ser-36 phosphate in H2B histone was increased from 0.38 microM to 1.16 microM in the absence of magnesium acetate, but not significantly changed (from 37.4 microM to 26.2 microM) in the presence of magnesium acetate. With the large form (Mr 224000) of the phosphoprotein phosphatase, however, the phosphorylation at Ser-32 suppressed the rate of Pi release from Ser-36 both in the absence and presence of magnesium acetate. The Km value of the large form for Ser-36 phosphatase in H2B histone was nevertheless increased by phosphorylation at Ser-32, from 1.2 microM to 5.3 microM in the presence of magnesium acetate, but not changed (from 0.26 microM to 0.23 microM) in the absence of magnesium acetate.

Animals↗