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Biomedical subjects

K Hatanaka

Publications and source records attributed to K Hatanaka.

At least 109 records · Page 6Linked to original sources
PubMed1994

Binding of serum amyloid P component to heparin in human serum.

It has been proposed that the function of serum amyloid P component (SAP) may closely relate with its binding to polysaccharides, especially glycosaminoglycans. We employed a quantitative immunoelectrophoresis (QIE) method and a native polyacrylamide gel electrophoresis (PAGE) method to characterize the SAP-heparin binding in soluble state. The SAP-heparin binding showed positive cooperativity. The apparent numbers of heparin molecules bound to SAP varied with the calcium concentration with a ratio of 1:1 (SAP/heparin), a Kd of 2.06 x 10(-7) M at 0.1 mM CaCl2 and a ratio of 1:1.6 (SAP/heparin), a Kd of 3.91 x 10(-7) M at 2 mM CaCl2, when estimated by the QIE method. No binding between SAP and heparin was observed in the absence of calcium. Magnesium and barium failed to induce the formation of SAP-heparin complex. Furthermore, they showed inhibitory effects on the calcium-mediated complex formation. We propose that heparin might be a regulator to modulate the anticoagulant activity of SAP and a useful drug to prevent SAP deposition on amyloid deposits.

Barium↗
PubMed1994

A case report of deficiency in an inhibitor of calcium-dependent association of protein S with C4B-binding protein suggested by a modified crossed immunoelectrophoresis.

We have experienced a coagulation factor VIII-deficient patient whose plasma has normal protein S (PS) activity and masses of free PS and its bound form in complex with C4b-binding protein (C4BP). Although the patient's plasma showed a normal ratio of free PS to PS-C4BP complex in the presence of 5 mM EDTA, the plasma gave an abnormally retarding major C4BP peak together with a major PS peak in the crossed immunoelectrophoresis (CIE) in the presence of 2 mM CaCl2. It was revealed that the major peak was formed by a mixture of PS-C4BP complex and free form. The addition of normal human plasma (NHP) to the patient's plasma inhibited the retardation of the major PS-C4BP complex. These suggest that the patient's plasma lacks some component(s) to inhibit Ca(2+)-dependent association of PS with C4BP.

Adult↗
PubMed1994

Effects of inhaled nitric oxide in rats with chemically induced pulmonary hypertension.

To determine the model animal with pulmonary hypertension in which nitric oxide (NO) inhalation reduces pulmonary arterial pressure (PAP), we examined the inhalation of 20-100 ppm NO gas on normal rats and rats with monocrotaline induced pulmonary hypertension. In the control group, mean PAP showed no change after spontaneous breathing of NO at the concentration of 20 to 100 ppm for 5 min. On the contrary, in both the severe (mean PAP > 40 mmHg) and moderate (mean PAP < 40 mmHg) pulmonary hypertensive groups, NO inhalation produced a prompt reduction of the mean PAP which had been elevated by monocrotaline. 20 ppm NO inhalation reduced mean PAP from 64.4 +/- 3.7 mmHg to 56.2 +/- 4.4 mmHg (mean +/- SEM, P < 0.01) in the severe pulmonary hypertensive group, from 31.0 +/- 2.0 mmHg to 24.2 +/- 0.9 mmHg in the moderate pulmonary hypertensive group (mean +/- SEM, P < 0.05). The onset of the reduction of mean PAP occurred within 30 sec after the start of NO inhalation and maximum reduction occurred within 4 min. 20 ppm NO inhalation significantly reduced mean PAP, and mean PAP was reduced dose-dependently at the concentration of 20 to 60 ppm and reaction to NO was almost constant at the concentrations of over 60 ppm.

Administration, Inhalation↗
PubMed1994

The effects of single lung transplantation in rats with monocrotaline-induced pulmonary hypertension.

Acute haemodynamic change after single lung transplantation for primary pulmonary hypertension was evaluated using a rat transplantation model. Inbred Fisher 344 rats were administered with 40 mg/kg monocrotaline in order to induce pulmonary hypertension. The rats whose mean pulmonary arterial pressure (PAP) was over 30.0 mm Hg received a left lung isograft from a normal donor after right heart catheterization. In the control group, PAP increased after single lung transplantation. On the other hand, in the pulmonary hypertensive group, PAP was significantly decreased 60 min after the transplantation, but 3 and 6 h after the transplantation, the PAP significantly increased again. On the day after the operation, it again decreased significantly. Left-to-right lung blood flow ratio was significantly increased in rats with pulmonary hypertension compared to rats with normal pulmonary pressure on both the 1st and 3rd postoperative days. The oedema of the grafted lung was more severe in the pulmonary hypertensive group than in the control group in the acute phase. In conclusion, single lung transplantation for pulmonary hypertension shifted pulmonary blood perfusion to the grafted lung and this shift made pulmonary oedema of the grafts more severe in the acute phase. These oedematous changes, which were more pronounced in the grafts in the pulmonary hypertensive rats, might have contributed to the transient rise in PAP in those rats after single lung transplantation.

Animals↗
PubMed1994

New surgical method of chordal replacement for mitral valve incompetence with echocardiographic guidance. An experimental study.

Chordal replacement with expanded polytetrafluorethylene suture has become a procedure of choice for repairing anterior leaflet prolapse among certain surgeons. However, most surgeons believe that the chordal replacement is too complicated and not reproducible. This report introduces a new method of chordal replacement using intraoperative epicardial and transesophageal echocardiography. Three dogs underwent the following procedures. One major marginal chorda of an anterior mitral leaflet was resected during cardiopulmonary bypass. A specially designed 3-0 polytetrafluoroethylene suture, having straight needles, was attached to the anterior leaflet by a mattress suture. Then the needles were brought from the root of the anterior papillary muscle to the outside of the left ventricle. After the bypass flow was reduced, both ends of the polytetrafluoroethylene suture were pulled under echocardiographic guidance until valve competence was achieved. At that point, the suture was temporarily tied. When cardiopulmonary bypass was discontinued, competence was again confirmed and the suture was tied permanently. When the procedures were completed, echocardiography showed trivial regurgitation and good pliability of the anterior leaflets in all animals. Left atrial pressures were sufficiently decreased. It appears that this new technique is reproducible for all surgeons because the optimal length of polytetrafluoroethylene chordae is determined with the valve functioning.

Animals↗
PubMed1993

A sensitive peroxidase staining immunoblotting method for measuring total protein S in human plasma.

In plasma, protein S is found in its free form and as a complex with C4b-binding protein. After 125I-protein S was added to normal human plasma and applied to SDS-8% polyacrylamide gel electrophoresis, the autoradiogram of the gel showed only one single band at free protein S position. Applying this evidence, we have developed a peroxidase staining Western Blotting method to quantitate total protein S in human plasma which consists of sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by blotting to nitrocellulose membrane and a sensitive avidin-biotinylated peroxidase staining method (ABC technique). The measurement of protein S by the immunoblotting was reproducible and the coefficient of variation was 7%. As little as 1 ng of protein S could be detected. C4b-binding protein did not affect the measurement of protein S. Compared to other immunoassays, this peroxidase staining immunoblotting method has the advantage of directly estimating the apparent molecular weight of protein of interest, eliminating nonspecific stain and having high sensitivity without using radioisotope.

Avidin↗
PubMed1993

Biosynthesis of curdlan from culture media containing 13C-labeled glucose as the carbon source.

13C-Labeled curdlans were biosynthesized by Agrobacterium sp. (ATCC 31749) from culture media containing D-(1-13C)glucose, D-(6-13C)glucose, or D-(2-13C)glucose as the carbon source, and their structures were analyzed by 13C NMR spectroscopy. The labeling was mainly found in the original position, that is, C-1, C-6, or C-2, indicating direct polymerization of introduced glucose. In addition, C-3 in curdlan obtained from D-(1-13C)glucose, C-1 in curdlan obtained from D-(6-13C)glucose, and C-1 and C-3 in curdlan obtained from D-(2-13)glucose were labeled. From analysis of this labeling, the biosynthesis of curdlan was interpreted as involving five routes: (1) direct synthesis from glucose; (2) rearrangement (1-13C-->3-13C); and (3) isomerization (6-13C-->1-13C) of cleaved trioses by the Embden-Meyerhof pathway, followed by neogenesis of glucose and formation of curdlan; (4) from fructose 6-phosphate formed in the pentose cycle (2-13C-->1-13C, 3-13C); and (5) neogenesis of glucose from fragments produced in various pathways of glycolysis. The 13C-labeling at C-6 and C-2 in the starting glucoses is well preserved in the C-6 carbon and the C-1 to C-3 carbons, respectively, in the curdlan produced.

Carbon Isotopes↗
PubMed1993

Action and binding of omega-conotoxin on the putative calcium channel of synaptosomal plasma membrane from electric organ of Japanese electric ray, Narke japonica.

Actions of omega-conotoxin GVIA on synaptosomes isolated from a Japanese electric ray, Narke japonica, were investigated. omega-Conotoxin inhibited, in a dose-dependent manner, both increases in free calcium concentration in, and acetylcholine release from synaptosomes depolarized with a high concentration of potassium ions. The concentrations of omega-conotoxin required for half-maximal inhibition (IC50) of increase in intrasynaptosomal Ca and acetylcholine release were 8 and 7 microM, respectively. Assay using radioiodinated toxin derivative revealed a specific binding site with a dissociation constant (KD) of 2.8 microM and a density (Bmax) of 45 pmol/mg protein of synaptosome. Binding assay with synaptosomal plasma membrane showed a KD = 7 microM and a Bmax = 200 pmol/mg protein. Autoradiography with sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis after covalent cross-linking of the toxin, using disuccinimidyl suberate, revealed the 170,000 mol. wt peptide to be an omega-conotoxin receptor. The present study has directly and clearly shown that omega-conotoxin inhibits acetylcholine release by blocking Ca influx into nerve terminals. The 170,000 mol. wt peptide identified as a receptor of the toxin exists in high density in the plasma membrane of the presynaptic nerve terminal and is likely to be a component of a voltage-dependent Ca channel responsible for the neurotransmitter release.

Acetylcholine↗
PubMed1993

Clinical experience using the Bio-pump for extracorporeal circulation during open-heart surgery.

The Bio-pump is still being used in a wide range of clinical applications such as open-heart surgery, left-heart bypass, extracorporeal membrane oxygenation, and supplementary circulation. Clinical application of the Bio-pump for extracorporeal circulation in 21 patients undergoing open-heart surgery was compared with application of the roller pump in terms of their effects on hemolysis, platelet function, and renal function. Although the amount of hemolysis was not significantly different between the Bio-pump group and the roller-pump group, platelet function was slightly better maintained in the Bio-pump group as judged by the levels of platelet factor 4, beta-thromboglobulin, and 6-keto-prostaglandin F1 alpha/thromboxane B2. There was no difference between the two pumps in terms of their effects on renal function. The above findings lead us to conclude that there is a slight advantage to use of the Bio-pump in clinical settings.

Blood Platelets↗
PubMed1993

Effect of sulfated polysaccharides on hepatocyte adhesion.

The effects of sulfated polysaccharides on hepatocyte adhesion on the polystyrene dish and fibronectin-coated dish were investigated. Dextran sulfate and synthetic mannopyranan sulfate slightly inhibited hepatocyte adhesion on fibronectin-coated dish, while heparin showed no effect. On the other hand, hepatocyte adhesion on polystyrene dishes was stimulated in the presence of sulfated polysaccharides in the medium.

Animals↗
PubMed1992

A new synthetic hypoglycaemic polysaccharide.

The synthetic (1-->6)-alpha-D-glucopyranan with branching and without branching were tested as a new hypoglycaemic drug. (1-->6)-alpha-D-glucopyranan having an alpha-D-glucopyranosyl branch at the C-3 position (1) showed a remarkable hypoglycaemic activity on i.p. injection to mice. The polysaccharide having both alpha- and beta-glucopyranosyl branches (2) also lowered the blood sugar (glucose) level in mice. On the other hand, the synthetic linear (1-->6)-alpha-D-glucopyranan (3) and alpha-D-glucopyranosyl branched polysaccharide (4) did not have a hypoglycaemic function, indicating that the branching glucose units are essential for the biological activity.

Animals↗
PubMed1992

[Clinical evaluation of treatment for prosthetic valve endocarditis and analysis of factors affecting outcome of surgical therapy].

We analyzed the outcome for 18 patients with prosthetic valve endocarditis (PVE) treated between 1965 and 1990, 17 of whom had undergone valve replacement with mechanical prosthetic valves and one of whom had a bioprosthesis. Two patients developed infection within 60 days after surgery, and 16 thereafter. Fifteen patients received combined medical and surgical therapy and three medical therapy. In 14 patients, surgery had been performed during active infection. Mortality rate of those who had received combined medical and surgical therapy was 27%, and that of those who had received medical therapy was 67%. At operation, para-annular abscess was around the mitral prosthesis was found in three patients and around the aortic prosthesis in eight. Seven patients required reoperation for postoperative paravalvular leakage, in six, para-annular abscess had been found at the operation for PVE, and in one para-annular abscess had been noted. One patient who had undergone reoperation had developed reinfection after the first surgery and died due to multiple organ failure after the second operation (Danielson's translocation technique). In one patient who had complete loss of supporting tissue because of severe para-annular abscess, we had performed aortic valve replacement by implanting the aortic valve prosthesis into the left ventricle with Dacron felt-supported sutures placed in the mitral annulus and the muscles of the left ventricular outflow tract. This patient showed no postoperative infection or no paravalvular leakage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

A strong inhibition of HIV-induced cytopathic effects by synthetic (1----6)-alpha-D-mannopyranan sulfate.

The anti-HIV effects of mannopyranan sulfate (1) were investigated by using MT-4 cells, namely, an HTLV-I-carrying CD-4 positive cell-line, in vitro. Stereoregular (1----6)-alpha-D-mannopyranan, which had been synthesized by ring-opening polymerization of a 1,6-anhydromannose derivative, was sulfated with piperidine-N-sulfonic acid to provide 1. N.m.r. analysis of 1 indicated that the reactivity of hydroxyl groups was in the order, 3-OH greater than 2-OH much greater than 4-OH. Mannopyranan sulfate having degree of substitution (d.s.) of 1.19-1.83 effectively inhibited HIV-induced cytopathic effects at a concentration of greater than 3.3 micrograms/mL. The anticoagulant activity and the adsorption on concanavalin A of 1 indicated the possibility of selective binding of 1 having d.s. of 1.19-1.83 to HIV-protein.

Anticoagulants↗
PubMed1991

Synthesis of a new inhibitor of the UDP-GalNAc:polypeptide galactosaminyl transferase.

Reaction of UDP-glucose with 1-hexadecanesulfonyl chloride (C16H33SO2Cl) in pyridine gave a new inhibitor of O-glycosylation. This reaction product was purified by TLC and shown by 1H-NMR and by chemical analysis of phosphorus to be uridine 5'-phosphoric (1-hexadecanesulfonic) anhydride. This compound was tested against the GalNAc transferase. The UMP-hexadecanesulfonic-anhydride did inhibit this enzyme with 50% inhibition requiring 160 microM. The inhibition with respect to UDP-GalNAc concentration was of the competitive type. We also synthesized the UMP-1-octanesulfonic anhydride (C8) and the UMP-butanesulfonic anhydride (C4) to see way effect fatty acid had on activity. The inhibition was in the order C16:C8:C4.

Anhydrides↗