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Biomedical subjects

K Hatanaka

Publications and source records attributed to K Hatanaka.

At least 19 recordsLinked to original sources
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↗
PubMed1991

Retarded nuclear migration in Drosophila embryos with aberrant F-actin reorganization caused by maternal mutations and by cytochalasin treatment.

Three X-linked mutations of Drosophila melanogaster, gs(1)N26, gs(1)N441 and paralog, had a common maternal-effect phenotype. Mutant embryos show reduced egg contraction that normally occurs at an early cleavage stage in wild-type embryos. In addition, the mutants exhibited retarded nuclear migration while synchronous nuclear divisions were unaffected. The retarded migration causes nuclei to remain in the anterior part of the embryo retaining their spherical distribution even in a late cleavage stage. This consequently results in an extreme delay in nuclear arrival in the posterior periplasm. A mutant phenocopy was induced in wild-type embryos that were treated with cytochalasin B or D at a very early cleavage stage. Remarkable differences were noticed in the organization of cortical F-actin between the mutants and the wild type throughout the cleavage stage: obvious F-actin aggregates were dispersed in the cortex of mutant embryos, in contrast to the wild type where the cortical F-actin layer was smooth and underlying F-actin aggregates were smaller than those in the mutants; the transition of the distribution pattern of F-actin in the yolk mass, from the centralized to the fragmented type, occurred later in the mutants than in wild type. The results suggest that these mutations affect the mechanism underlying establishment and transition of F-actin organization required for normal egg contraction and nuclear migration in the cleavage embryos.

Actins↗
PubMed1991

[Surgical repair of ischemic mitral regurgitation].

We studied surgical results of 14 cases of ischemic mitral regurgitation. There was no surgical death in 10 cases with left ventricular aneurysm, and their clinical symptoms improved except 3 with the combined operation of left ventricular aneurysmectomy, mitral annuloplasty and bypass grafting. The range of the abnormal contracting segment significantly decreased after surgery except in 3 cases in whom clinical status was not improved. Three of 4 cases which underwent bypass grafting and mitral annulo-valvuloplasty survived, but one of them died of graft-versus-host disease. In the three survived cases, severe mitral regurgitation disappeared. We have concluded as follows: In cases of left ventricular aneurysm, a sufficient aneurysmal resection is very important to control the mitral regurgitation, and the additional procedures of mitral annuloplasty and bypass grafting are essential. The mitral valve replacement is recommended in case of the complete disruption of the papillary muscle. Mitral valvuloplasty combined with annuloplasty is suitable to control the regurgitation in the regional mitral prolapse due to the torn chordae.

Adult↗
PubMed1990

Purification to homogeneity and properties of glucosidase II from mung bean seedlings and suspension-cultured soybean cells.

Glucosidase II was purified approximately 1700-fold to homogeneity from Triton X-100 extracts of mung bean microsomes. A single band with a molecular mass of 110 kDa was seen on sodium dodecyl sulfate gels. This band was susceptible to digestion by endoglucosaminidase H or peptide glycosidase F, and the change in mobility of the treated protein indicated the loss of one or two oligosaccharide chains. By gel filtration, the native enzyme was estimated to have a molecular mass of about 220 kDa, suggesting it was composed of two identical subunits. Glucosidase II showed a broad pH optima between 6.8 and 7.5 with reasonable activity even at 8.5, but there was almost no activity below pH 6.0. The purified enzyme could use p-nitrophenyl-alpha-D-glucopyranoside as a substrate but was also active with a number of glucose-containing high-mannose oligosaccharides. Glc2Man9GlcNAc was the best substrate while activity was significantly reduced when several mannose residues were removed, i.e. Glc2Man7-GlcNAc. The rate of activity was lowest with Glc1Man9GlcNAc, demonstrating that the innermost glucose is released the slowest. Evidence that the enzyme is specific for alpha 1,3-glucosidic linkages is shown by the fact that its activity on Glc2Man9GlcNAc was inhibited by nigerose, an alpha 1,3-linked glucose disaccharide, but not by alpha 1,2 (kojibiose)-, alpha 1,4(maltose)-, or alpha 1,6 (isomaltose)-linked glucose disaccharides. Glucosidase II was strongly inhibited by the glucosidase processing inhibitors deoxynojirimycin and 2,6-dideoxy-2,6-imino-7-O-(beta-D- glucopyranosyl)-D-glycero-L-guloheptitol, but less strongly by castanospermine and not at all by australine. Polyclonal antibodies prepared against the mung bean glucosidase II reacted with a 95-kDa protein from suspension-cultured soybean cells that also showed glucosidase II activity. Soybean cells were labeled with either [2-3H]mannose or [6-3H]galactose, and the glucosidase II was isolated by immunoprecipitation. Essentially all of the radioactive mannose was released from the protein by treatment with endoglucosaminidase H. The labeled oligosaccharide(s) released by endoglucosaminidase H was isolated and characterized by gel filtration and by treatment with various enzymes. The major oligosaccharide chain on the soybean glucosidase II appeared to be a Man9(GlcNAc)2 with small amounts of Glc1Man9(GlcNAc)2.

Carbohydrate Sequence↗
PubMed1990

[A case of nephrotic syndrome with abnormally high level of protein C induced by prednisolone].

Adrenocortical hormones have been used for nephrotic syndrome from 1950. But effects of these drugs in coagulation and fibrinolysis are unknown in detail. We studied the effect of prednisolone in a patient with nephrotic syndrome. Protein C increased remarkably after administration of prednisolone 40 mg/day and then decreased in parallel with the dose of prednisolone. Factor X increased more slowly than Protein C. On the other hand, we couldn't find increase of Protein S. Our results indicate that prednisolone have anticoagulant effect by promotion of production of Protein C.

Blood Coagulation↗
PubMed1989

Plant glucosidase II catalyzes a transglucosylation reaction in addition to the hydrolytic reaction.

When the purified plant glucosidase II was incubated with [3H]Glc2Man9GlcNAc in the presence of glycerol and the products were analyzed by gel filtration, a large peak of radioactivity emerged just before the glucose standard. The formation of this peak was dependent on both the presence of Glc2Man9GlcNAc and the presence of glycerol, and the amount of this product increased with time of incubation and amount of glucosidase II in the incubation. When the incubation was performed with [3H]Glc2Man9GlcNAc plus [14C]glycerol, the product contained both 14C and 3H. Strong acid hydrolysis of the purified product gave rise to [14C]glycerol and [3H]glucose. Various other chemical treatments and chromatographic techniques showed that the product was glucosyl----glycerol. Since the glucose was released by alpha-glucosidase, the product must be glucosyl-alpha-glycerol. This study demonstrates that the processing glucosidase II catalyzes a trans-glycosylation reaction in the presence of acceptors like glycerol. Since this transglycosylation reaction may give rise to unexpected products, investigators should be aware of its possible occurrence.

Fabaceae↗
PubMed1989

Synthesis of an inhibitor of human immunodeficiency virus infection.

Anti-HIV effects of lentinan sulfate were investigated by using an HTLV-I-carrying cell line, MT-4, in vitro. Lentinan, a fungal branched (1----3)-beta-D-glucan, was sulfated to various degrees by means of two kinds of procedures using piperidine N-sulfonic acid in dimethyl sulfoxide or chlorosulfonic acid in pyridine. Lentinan sulfate with a sulfur content of more than 13.9% effectively prevented HIV-induced cytopathic effects (CPE) at concentrations of more than 3.3 micrograms/ml. However, low-substituted lentinan sulfate did not prevent HIV-induced CPE at any concentration tested. When the countercation was 50% Na+ and 50% pyridinium ion, the inhibitory capacity was low. Anticoagulant activity of the lentinan sulfate was also assessed.

Anticoagulants↗
PubMed1987

Synthesis of new heparinoids with high anticoagulant activity.

New heparinoids were synthesized by the chemical method starting from ring-opening polymerization of anhydro sugar derivatives. Sulfation of synthetic (1----6)-alpha-linked 3-amino-3-deoxy-D-glucopyranan and its copolymers gave dextran-type heparinoids having a sulfamide group on the C-3 carbon of the sugar unit. Heparinoids with different sulfamide contents indicated that the anticoagulant activity (35.3-41.3 units/mg) is independent of the sulfamide content, while an increase in sulfamide content lowered the toxicity. Sulfation of (1----5)-alpha-D-xylofuranan and -ribofuranan provided furanan-type heparinoids the anticoagulant activities of which were higher than those of the corresponding sulfated pyranan-type polysaccharides (1----4)-beta-D-xylopyranan and -ribopyranan. The highest activity (69.1 units/mg) was shown by sulfated (1----5)-alpha-D-xylofuranan. The dextran-type heparinoid having a sulfamide group showed a high anticoagulant activity also in vivo and high lipemia-clearing activity.

Animals↗
PubMed1985

High susceptibility to ADP-induced thrombus formation in mast cell-deficient W/Wv mice.

We used mast cell-deficient W/Wv mice to clarify whether mast cell-derived heparin may play a role in inhibiting thrombus formation in the living organism. Small veins in the mesentery of W/Wv or congenic +/+ mice were stretched over an inverted microscope; a micropipette filled with varying concentrations of ADP was set close to the outside of a vein by using a micromanipulator. Thrombus formation was directly examined under the microscope. The concentration of ADP necessary for thrombus formation was significantly lower in the W/Wv mice than in the congenic +/+ mice. Furthermore, the concentration of ADP necessary for aggregation of platelets in platelet-rich plasma (PRP) was significantly lower in W/Wv mice than in +/+ mice. The higher sensitivity of PRP of W/Wv mice is not attributed to the platelets, but to the plasma, since platelets of +/+ mice suspended in platelet-poor plasma (PPP) of W/Wv mice were more sensitive to ADP than platelets of W/Wv mice suspended in PPP of +/+ mice. The present results suggest that plasma of W/Wv mice may lack any inhibitory factor(s) or contain promoting factor(s) for platelet aggregation.

Adenosine Diphosphate↗
PubMed1979

Distribution of mast-cell precursors in hematopoeitic and lymphopoietic tissues of mice.

Two experimental systems were used to investigate the origin of precursor cells which differentiate into tissue mast cells in vivo. (a) Increase of mast cell number was examined in the skin, stomach, cecum, and mesentery of genetically mast cell-depleted WBB6F1 (WB X C57BL/6)-W/WV mice after the injection of various hematolymphoid cells of congenic +/+ mice. (b) Appearance of mast cells with giant granules was studied in irradiated C57BL/6-+/+ mice after the injection of lymphoid cells of C57BL/6-bgJ/bgJ (beige, Chediak-Higashi syndrome) mice. Concentrations of mast cell precursors in the thymus, lymph node and Peyer's patch were less than 0.1% of the concentration in the bone marrow. Neither treatment of donor bone marrow cells with anti-Thy-1.2 serum and complement nor thymectomy of the recipient mice affects the development of mast cells in the skin, stomach, cecum, and mesentery. Moreover, the number of mast cells increased to normal level when the skin of WBB6F1-W/WV mice was grafted on the back of nude athymic (BALB/c-nu/nu) mice. These results indicate that mast cell precursors are derived from hematopoietic tissues rather than lymphopoetic ones and that the differentiation of the precursor cells does not depend on T lymphocytes or the thymus.

Animals↗
PubMed1979

Clonal nature of mast-cell clusters formed in W/Wv mice after bone marrow transplantation.

We have recently found that the number of mast cells in the skin of adult W/Wv mice is less than 1% of that observed in congeneic +/+ mice, and that no mast cells are detected in other tissues of W/Wv mice. After the transplantation of bone marrow cells from congeneic +/+ mice, the number of mast cells in the skin, stomach, caecum and mesentery of the W/Wv mice increased to levels similar to those of the +/+ mice. Study of the mast-cell number in the W/Wv mice at various times after transplantation suggested to use that mast cells might develop in groups, particularly in the skin and mesentery. In this report, we have attempted to elucidate the possible clonal origin of such mast-cell clusters from a single precursor cell, using giant granules of beige (C57BL/6-bgJ/bgJ, Chediak-Higashi syndrome) mice as a marker to identify the origin of the mast cells (Fig. 1). We found that when WB-W/+xC57BL/6-Wv (WBB6F1)-W/Wv mice were injected with a mixture of bone marrow cells from beige C57BL/6 mice and normal C57BL/6 mice, more than 95% of mast-cell clusters consisted of either beige-type cells alone or normal-type cells alone. We conclude, therefore, that the cluster of mast cells originated from a single precursor cell.

Animals↗
PubMed1979

Presence of mast cell precursors in peripheral blood of mice demonstrated by parabiosis.

The presence of mast cell precursors in peripheral blood was examined. The beige C57BL/6 (bgj/bgj, Chediak-Higashi syndrome) mouse was parabiosed with the normal C57BL/6 mouse. Mast cells containing giant granules and originating in the beige partner appeared in the normal parabiont. A comparable proportion of normal-mouse-type mast cells developed in the beige parabiont as well. In spite of the low radiosensitivity of mature mast cells, irradiation of the normal parabiont reduced the proportion of normal-mouse-type mast cells appearing in the beige partner. It was concluded, therefore, that the precursors of mast cells can migrate through the bloodstream.

Animals↗
PubMed1979

Local development of mast cells from bone marrow-derived precursors in the skin of mice.

A mechanism to control development of mast cells was investigated in mice. Although mast cells in the skin of normal C57BL/6 mice were still of host type 290 days after irradiation and injection of bone marrow cells from beige (Chediak-Higashi syndrome, C57BL/6 bgJ/bgJ) mice, donor-type mast cells with giant granules appeared after painting of methylcholanthrene on the dorsal skin. Since donor-type mast cells appeared only at the painted portion of the skin, with an increase in the labeling index of such donor-type mast cells with 3H-thymidine, proliferation and differentiation of bone marrow-derived precursors of mast cells seem to be controlled locally. Although the morphologic feature of marrow-derived precursors was not identified, the finding that all fibroblasts cultured from the methylcholanthrene-treated skin were of host type may exclude the possibility that fibroblasts are the precursors of mast cells.

Bone Marrow Cells↗