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Biomedical subjects

J Hirose

Publications and source records attributed to J Hirose.

At least 73 records · Page 4Linked to original sources
PubMed1991

Photoreversible antigen-antibody reactions.

A monoclonal antibody (Z1H01) for an oligopeptide carrying an azobenzene group, was prepared under conditions where the azobenzene group is in the trans form. The antibody bound the hapten peptide effectively when the hapten peptide is in the trans form (K = 5 x 10(7) M-1), but the antibody released the hapten under irradiation with UV light where the hapten is in the cis form. The antibody bound the hapten again, when the hapten reverted to the trans form after irradiation with visible light.

Animals↗
PubMed1991

Purification of megakaryocyte differentiation activity from a human fibrous histiocytoma cell line: N-terminal sequence homology with activin A.

We purified a protein possessing a potent ability to induce the differentiation of a murine megakaryoblastic cell line, L8057, from the supernatant of a human fibrous histiocytoma cell line, KHM-5M. The protein, a homodimer of a molecular weight of 25-kDa, has an N-terminal sequence identical with that of the beta A-chain of inhibin, indicating that it is identical to or highly homologous with activin A. Thus, it is speculated that activin A or its homologue is involved in megakaryocytic differentiation.

Activins↗
PubMed1991

A case of splenic inflammatory pseudotumor.

Inflammatory pseudotumor of the spleen in a 50-year-old man was encountered in our surgical clinic. This splenic tumor is very rare and in the ninth of the cases in the literature. The removed spleen, weighting 255g, revealed the presence of a firm, circumscribed mass, measuring 4.5 x 4.0 x 4.5 cm, and histologically presenting marked lamination of collagen fibers around the small vessels associated with granulomatous lesions. The implications of its pathogenesis was analyzed with a review of the literature.

Granuloma, Plasma Cell↗
PubMed1991

Percutaneous fiberoptic angioscopy of the cardiac valves.

The feasibility of percutaneous translumial angioscopy of the cardiac valves was examined in eight patients with and in 11 patients without valvular disease. In eight of these patients, a guiding balloon catheter (9F) was introduced into the aortic root, a guide wire (0.014 or 0.025 inch) was introduced through the catheter into the left ventricle to prevent dislocation of the catheter, and a fiberscope (1.6 or 4.6F) was advanced to the distal tip of the catheter. The balloon was then inflated with carbon dioxide and was manipulated against the aortic valve; a body temperature heparinized saline was infused through the catheter for observation. Similarly, the balloon catheter was advanced transseptally into the left atrium for observation of the mitral valve in four patients. Also, the balloon catheter was advanced through the right femoral vein into the right atrium for observation of the tricupid valve in three patients. In patients with a normal aortic valve, the aortic cusp surface was smooth and white and the edges were sharp. They opened briskly during systole and coapted each other completely during diastole. In rheumatic aortic regurgitation, the cuspus were thick and blunt and their coaptation insufficiency was observed during diastole. In a patient with rheumatic AS, globular and yellow cusps were observed. Mitral valve leaflets were smooth and white in a patients without mitral valvular disease, while the leaflets were yellow, thick and irregular, and blood regurgitation from the left ventricle into the left atrium could be observed in two patients with rheumatic MSR. The process of opening and closure of a tricuspid valve was also observed in three patients without tricuspid valvular disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Percutaneous fiberoptic cardioscopy of the left ventricle.

The feasibility of percutaneous transluminal cardioscopy of the left ventricle was examined in 35 patients with or without various heart diseases. A guiding balloon catheter (7 or 9 French) was introduced through the right femoral artery into the left ventricle. The balloon was inflated, and a fiberscope (1.6 or 4.3 French) was advanced to the distal tip of the catheter. The balloon was then manipulated against the portion of the ventricle targeted for examination, and heparinized saline (10 U/ml) at body temperature was infused through the catheter at 5 ml/sec for 3 to 6 sec. The images were recorded on videotape and 16 mm cinefilm. In 4 patients without demonstrable heart disease, the endocardial surface of the left ventricle was brown and the trabeculae became prominent during systole. The chordae connected to the mitral leaflets were white. In 3 of 5 patients with dilated cardiomyopathy, the endocardium was light yellow with thin trabeculae which barely contracted during systole. The endocardium was red or reddish-brown in 3 patients with acute myocarditis. In patients with rheumatic mitral stenosis white patches were scattered on the endocardial surface. In 7 of 8 patients the akinetic or dyskinetic segments representing prior infarctions were white. No complications other than transient ventricular arrhythmias were noted. We conclude that percutaneous fiberscopic imaging with a guiding balloon catheter is feasible and safe, and yields highly detailed images of the endocardium.

Acute Disease↗
PubMed1990

Antibodies against (1R,2R)-cyclohexanediamineplatinum(II)-DNA adduct recognize the conformational differences of isomeric analogues of cyclohexanediamine.

Antibodies reactive to (1R,2R)-cyclohexanediamineplatinum(II)-DNA ((1R,2R)-cyclohexanediamine: 1R,2R-dach) adducts were elicited by immunization of rabbit with calf thymus DNA modified by Pt(1R,2R-dach)Cl2 at a ratio of bound platinum per nucleotide ((D/N)b) of 0.0335. In an enzyme-linked immunosorbent assay (ELISA), the binding of specific antibodies to Pt(1R,2R-dach)-DNA adduct (60 microliters of 1.235 x 10(-7) M Pt in each wells) on the assay plate was competitively inhibited by Pt(1R,2R-dach)-DNA adduct ((D/N)b = 0.0653) in the solution. Almost equal inhibition was observed with Pt(1S,2S-dach)-DNA ((D/N)b = 0.0412), an optical isomer of 1R,2R-dach. Pt(1R,2S-dach)-DNA ((D/N)b = 0.0371) and Pt(1R,3S-dach)-DNA ((D/N)b = 0.0281) in which the cyclohexane ring is stereochemically perpendicular to the platinum chelate plane, also inhibited antibody binding, but these adducts gave only incomplete inhibition at higher Pt-DNA adduct concentrations. Although Pt(1R,2R-dach)-d(GpG) and Pt(1R,2R-dach)(NH3)2 inhibited antibody binding, the affinity of the antibody for Pt(1R,2R-dach)(NH3)2 was lower than with Pt(1R,2R-dach)-DNA, and the inhibition behavior of Pt(1R,2R-dach)-d(GpG) was biphasic, i.e., at the lower concentration the inhibition curve was consistent with that of Pt(1R,2R-dach)-DNA, but at the higher concentration it shifted to that of Pt(1R,2R-dach)(NH3)2. The affinity of the antibody for cis-DDP was markedly lower than with Pt(1R,2R-dach)(NH3)2. These facts suggest that the antibodies may bind to the substituents (the platinum and its surroundings) of the various Pt complexes rather than the DNA structure altered by platinum binding.

Animals↗
PubMed1990

Percutaneous fiberoptic angioscopy of the left ventricle in patients with dilated cardiomyopathy and acute myocarditis.

Left ventricular luminal changes were examined by percutaneous fiberoptic angioscopy in 13 patients with dilated cardiomyopathy and in four patients with acute myocarditis. Angioscope-guided endomyocardial biopsy was also performed in six patients with dilated cardiomyopathy and in two with acute myocarditis. A balloon-tipped guiding catheter (9F) was introduced through the right femoral artery into the left ventricle, the balloon was inflated, and a 1.6 or 4.3F fiberscope was introduced through the catheter into the ventricle so as to locate the fiberscope tip at the tip of the catheter shaft. The balloon was then pushed against the desired portion of the ventricle and warmed saline was infused to observe the luminal changes. In contrast to the patients without organic heart disease whose left ventricular luminal surface was brown in color, the luminal surface was white or light yellow in four, light brown in one, bluish-white in one, with white and brown portions distributed in a mosaic pattern in four, and it was reddish brown in the remaining one patient with dilated cardiomyopathy. Mural thrombi were observed in two of the patients. The luminal surface was light brown in one, reddish brown in one, rose in one, and red in one patient with acute myocarditis. Thrombi and scattered bleeding were observed in two and one of these patients, respectively. The changes in luminal coloration in patients with dilated cardiomyopathy and acute myocarditis had no obvious relation to left ventricular volume and ejection fraction. Angioscope-guided biopsy revealed that the white and light yellow portions were due to endocardial fibrosis, that the endocardia of brown portions were not fibrotic, and that the myocardium in the red portions contained mononuclear cells, indicating inflammation. The results indicate that the angioscopic features of the left ventricular luminal surface were not uniform in patients with dilated cardiomyopathy or in those with acute myocarditis, and that angioscopy can be used as a guiding tool for endomyocardial biopsy.

Acute Disease↗
PubMed1990

[Angiographic anatomy of arterial branches to the caudate lobe of the liver with special reference to its effect on transarterial embolization of hepatocellular carcinoma].

The arterial branches to the caudate lobe of the liver have been little studied angiographically, so it has been thought that the branches can be rarely recognized on the hepatic angiogram. We evaluated it with the stereo or stereo-magnification angiograms in 106 cases. They were identified in 90 cases (84.9%), one branch in 75 cases, two branches in 15 cases. The branches had a variable origin. In 50%, it originated from the right hepatic artery. In some cases, it came from both the right and left hepatic arteries. Recently we treated 10 cases of hepatocellular carcinoma in the caudate lobe with transcatheter arterial embolization (TAE), the results were poor in them except for one. We think that the proximal and variable origins of the caudate lobe arteries are the main cause of the poor effect of TAE.

Angiography↗
PubMed1989

A 1H NMR study of cobalt(II) arsanilazocarboxypeptidase A.

Cobalt(II) arsanilazotyrosine-248 carboxypeptidase A has been characterized through 1H NMR spectroscopy. The ability of the azoenzyme to form binary and ternary complexes with L- and D-phenylalanine and azide has been investigated. Comparison with the 1H NMR results obtained on unmodified cobalt(II) carboxypeptidase provides direct information on the specific effect of the presence of the azo group on the reactivity of the system. Marked differences in the interaction with D-phenylalanine have been observed, and structural inferences are drawn.

Carboxypeptidases↗
PubMed1989

[Long-term effects of partial splenic embolization (PSE) for hypersplenism].

24 cases of hypersplenism were treated by PSE using Gelfoam particles. In cases with 90% embolized, the mean WBC and platelet counts were improved for 5.0 and 3.4 months. In cases with over 60% embolized, those were improved for 19.6 and 19.3 months. 9 cases with over 60% embolized remain in good condition more than 2 years, especially 2 cases of them remain more than 3 years. One patient with total embolized developed a splenic abscess and died after one month from PSE. But another severe complications were not shown.

Adult↗
PubMed1988

Calcium-requirement and its pH dependency of lysophosphoinositide-specific phospholipase C in porcine platelet membranes.

The lysophosphoinositide-specific phospholipase C (lysoPI-PLase C) in porcine platelet membranes had an optimal pH of 9.2 and the activity at a physiological pH of 7.3 was 20% of the maximum in the absence of added divalent metals (Murase, S. et al. (1985) J. Biol. Chem. 260, 262). The activity was completely inhibited by 1 mM EGTA in the assay mixture but was restored by addition of excess Ca2+ or Mn2+, indicating that this is a metalloenzyme. However, membranes pretreated with 1 mM EGTA and washed with buffer retained full activity at a free Ca2+ concentration of 5 nM and no stimulation was observed by added Ca2+ at pH 9.2. In contrast to the results obtained at pH 9.2, addition of Ca2+ stimulated lysoPI-PLase C activity severalfold at pH 7.3, apparently by shifting down the optimal pH and broadening the pH profile. The effect of Ca2+ at pH 7.3 was to enhance Vmax with no significant change in Km value. The stimulatory effect of Ca2+ at pH 7.3 alone did not appear to be of physiological significance since millimolar concentrations of Ca2+ were necessary to reach the maximum activity. However, a shift in pH had a profound effect on the Ca2+-dependency of the activity. A rise in 2 pH units increased the apparent affinity for Ca2+ 10,000-fold. These results indicate that the alkalinization and the rise in free Ca2+ concentration known to occur in stimulated platelets could synergistically provide conditions under which the lysoPI-PLase C exerts its activity when the substrate lysoPI is generated by phospholipase A.

Animals↗