Search PubMed⌕ Search

Biomedical subjects

H Kaku

Publications and source records attributed to H Kaku.

At least 73 records · Page 4Linked to original sources
PubMed1992

Preparation of a stable subunit of Japanese elderberry (Sambucus sieboldiana) bark lectin and its application for the study of cell surface carbohydrates by flow cytometry.

A stable subunit of Sambucus sieboldiana bark lectin (MSSA) was prepared by selective reduction of disulfide bridges between the subunits and alkylation with 4-vinylpyridine. Amino acid analysis of MSSA revealed that 1.4 cysteine residues per subunit were selectively modified. MSSA failed to agglutinate rabbit erythrocytes and precipitate fetuin. However, MSSA retained the ability to bind to fetuin, as detected by ELISA. Neu5Ac alpha 2-6lactose inhibited the binding to fetuin of both SSA and MSSA. Flow cytometric analysis showed that human histocytic lymphoma U937 cells were clearly stained with FITC-labeled MSSA (FITC-MSSA) without any detectable agglutination and that this staining was almost completely inhibited by the addition of Neu5Ac alpha 2-6lactose (2 mM). Treatment of U937 cells with native FITC-SSA at the sub-agglutinating concentration (0.3 microgram/ml) showed much poorer fluorescence intensity than that of MSSA, suggesting that MSSA is an invaluable tool for the detection of cell surface glycoconjugates containing NeuAc alpha 2-6Gal/GalNAc sequences by flow cytometry.

Carbohydrate Sequence↗
PubMed1992

Interaction of linear manno-oligosaccharides with three mannose-specific bulb lectins. Comparison with mannose/glucose-binding lectins.

Three new mannose-binding lectins, isolated from daffodil (NPA), amaryllis (HHA), and snowdrop (GNA) bulbs, are capable of precipitating with a linear mannopentaose (Man alpha 1-3Man alpha 1-3Man alpha 1-3Man alpha 1-2Man). NPA and HHA reacted strongly with the mannopentaose whereas GNA gave a precipitate only at concentrations greater than 500 microM. A phosphate group at C-6 of the nonreducing terminal mannosyl group prevented precipitation in all three cases. The reduced (NaBH4) mannopentaose, Man4Man-ol, did not precipitate with GNA or NPA, but was active with HHA. This activity was lost when Man4Man-ol was converted (NaIO4 then NaBH4; mild acid hydrolysis of the reduced product) into trisaccharide derivatives. With alpha-D-Manp-OMe the three lectins gave UV difference spectra having large positive peaks at 292-293 and 283-284 nm, and a small positive peak at 275 nm, characteristic of tryptophanyl and tyrosyl residues. The association constants for the interaction with alpha-D-Manp-OMe were very low (NPA, 86; HHA, 66; and GNA, 41 M-1), but the lectins bound methyl (1----3)-alpha-mannobioside with increased affinity (K for NPA 540, for HHA 2400, and for GNA 200 M-1). The bulb lectins lack binding sites for hydrophobic ligands, as judged by their failure to interact with the fluorescent probes 8-anilino-1-napthalenesulfonic acid (ANS) and 6-p-toluidino-2-naphthalenesulfonic acid (TNS).

Carbohydrate Sequence↗
PubMed1992

New mannose-specific lectins from garlic (Allium sativum) and ramsons (Allium ursinum) bulbs.

Two new mannose-binding lectins were isolated from garlic (Allium sativum, ASA) and ramsons (Allium ursinum, AUA) bulbs, of the family Alliaceae, by affinity chromatography on immobilized mannose. The carbohydrate-binding specificity of these two lectins was studied by quantitative precipitation and hapten-inhibition assay. ASA reacted strongly with a synthetic linear (1----3)-alpha-D-mannan and S. cerevisiae mannan, weakly with a synthetic (1----6)-alpha-D-mannan, and failed to precipitate with galactomannans from T. gropengiesseri and T. lactis-condensi, a linear mannopentaose, and murine IgM. On the other hand, AUA gave a strong reaction of precipitation with murine IgM, and good reactions with S. cerevisiae mannan and both synthetic linear mannans, suggesting that the two lectins have somewhat different binding specificities for alpha-D-mannosyl units. Of the saccharides tested as inhibitors of precipitation, those with alpha-(1----3)-linked mannosyl units were the best inhibitors of ASA, the alpha-(1----2)-, alpha-(1----4)-, and alpha-(1----6)-linked mannobioses and biosides having less than one eighth the affinity of the alpha-(1----3)-linked compounds. The N-terminal amino acid sequence of ASA exhibits 79% homology with that of AUA, and moderately high homology (53%) with that of snowdrop bulb lectin, also an alpha-D-mannosyl-binding lectin.

Allium↗
PubMed1991

Biosynthesis, primary structure and molecular cloning of snowdrop (Galanthus nivalis L.) lectin.

Poly(A)-rich RNA isolated from ripening ovaries of snowdrop (Galanthus nivalis L.) yielded a single 17-kDa lectin polypeptide upon translation in a wheat-germ cell-free system. This lectin was purified by affinity chromatography. Translation of the same RNA in Xenopus leavis oocytes revealed a lectin polypeptide which was about 2 kDa smaller than the in vitro synthesized precursor, suggesting that the oocyte system had removed a 2-kDa signal peptide. A second post-translational processing step was likely to be involved since both the in vivo precursor and the Xenopus translation products were about 2 kDa larger than the mature lectin polypeptide. This hypothesis was confirmed by the structural analysis of the amino acid sequence of the mature protein and the cloned mRNA. Edman degradation and carboxypeptidase Y digestion of the mature protein, and structural analysis of the peptides obtained after chemical cleavage and modification, allowed determination of the complete 105 amino acid sequence of the snowdrop lectin polypeptide. Comparison of this sequence with the deduced amino acid sequence of a lectin cDNA clone revealed that besides the mature lectin polypeptide, the lectin mRNA also encoded a 23 amino acid signal-sequence and a C-terminal extension of 29 amino acids, which confirms the results from in vitro translation experiments.

Amino Acid Sequence↗
PubMed1991

Interactions of five D-mannose-specific lectins with a series of synthetic branched trisaccharides.

The interaction of a series of synthetic, branched trisaccharides with five D-mannose-specific lectins was studied by precipitation-inhibition assay. The branched methyl alpha-D-mannotrioside, alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-alpha-D-Man pOMe, the best inhibitor of the Con A-Dextran interaction, was 42 times more potent than alpha-D-ManpOMe, and 3-6 times more potent than the two trisaccharides substituted with D-glucosyl groups, and 8-15 times those with D-galactosyl groups. Surprisingly, methyl O-alpha-D-mannopyranosyl-(1----3)-alpha-D-mannopyranoside was bound to Con A 8-fold more avidly than methyl alpha-D-mannopyranoside. However, the related pea lectin (PSA) was singularly different from Con A in its carbohydrate-binding activity, showing no significantly enhanced binding to any of the sugars examined. The trisacchrides containing terminal, nonreducing, (1----3)-linked alpha-D-mannopyranosyl groups, i.e., alpha-D-Manp-(1----3)-[alpha-D-Glep-(1----6)]alpha-D-Manp OMe, alpha-D-Manp-(1----3)]-alpha-D-Galp-(1----6)]-alpha-D-ManpOMe++ +, and alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-alpha-D-Man pOMe, were the best inhibitors of the snowdrop lectin (GNA)-D-mannan precipitation system. On the other hand, all branched trisaccharides exhibited very similar inhibitory potencies toward the daffodil lectin (NPA)-D-mannan interaction, whereas alpha-D-Manp-(1----3)-[alpha-D-Galp-(1----6)]-alpha-D-ManpOMe++ + and alpha-D-Manp-(1----3)-[alpha-D-Manp-(1----6)]-alpha-D-Man pOMe were somewhat better inhibitors than the other branched trisaccharides of the amaryllis lectin (HHA)-D-mannan precipitation reaction. (ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate Conformation↗
PubMed1991

[Clinical significance of serum dipeptidyl aminopeptidase IV in rats with adjuvant arthritis].

Serum dipeptidyl aminopeptidase IV (DAP IV) activity in rats with adjuvant arthritis (AA) were studied. DAP IV activity was significantly low in AA rats (37.7 +/- 14.1 mU/ml, n = 15) compared with control (63.7 +/- 9.0 mU/ml, n = 8) and indomethacin-treated (IDM) AA rats (55.6 +/- 14.2 mU/ml, n = 15). In addition, serum DAP IV activity was inversely correlated with hindpaw arthritis score both in AA rats and IDM-AA rats. Among serum inflammatory index examined, acid soluble glycoprotein, sialic acid were inversely correlated and albumin was positively correlated with DAP IV activity in AA and IDM-AA rats. The role of serum DAP IV remains unknown, but, it seems possible that DAP IV might modify the clinical course of AA rats in connection with its effects on the immune regulatory system.

Animals↗
PubMed1990

Crystallization and preliminary X-ray diffraction results of snowdrop (Galanthus nivalis) lectin.

Well-ordered single crystals have been grown for a mannose-specific lectin from snowdrop (Galanthus nivalis) bulbs in the presence of methyl-alpha-D-mannoside. The space group symmetry is consistent with the orthorhombic space group P2(1)2(1)2(1). The unit cell parameters are a = 140.0 A, b = 64.7 A, c = 62.0 A. The asymmetric unit can accommodate a tetramer. The functional molecule (50,000 daltons) consists of four identical subunits and is highly specific for alpha 1,3-linked mannose oligosaccharides.

Crystallography↗
PubMed1990

Carbohydrate-binding specificity of the daffodil (Narcissus pseudonarcissus) and amaryllis (Hippeastrum hybr.) bulb lectins.

The carbohydrate binding specificity of the daffodil (Narcissus pseudonarcissus; NPA) and amaryllis (Hippeastrum hybr.; HHA) lectins, isolated from extracts of their bulbs by affinity chromatography on immobilized mannose, was studied by quantitative precipitation, sugar hapten inhibition, and affinity chromatography on the immobilized lectins. These lectins gave strong precipitation reactions with several yeast mannans, but did not precipitate with alpha-D-glucans (e.g., dextrans and glycogen). Interestingly, both lectins reacted strongly with yeast galactomannans having multiple nonreducing terminal alpha-D-galactosyl groups, a synthetic linear alpha-1,6-mannan, and an alpha-1,3-mannan (DP = 30). Treatment of the linear alpha-1,3-mannan with periodate, resulting in oxidation of the terminal, nonreducing mannosyl group, did not reduce its reactivity with NPA or HHA. Taken together, these observations suggest that NPA and HHA react not only with terminal but also with internal alpha-D-mannosyl residues. Sugar hapten inhibition studies showed these lectins to possess the greatest specific activity for alpha-D-mannosyl units whereas D-Glc and D-GlcNAc did not inhibit either lectin precipitation system. Of the oligosaccharides tested, the best inhibitor of NPA interaction was alpha-1,6-linked mannotriose, which was twice as good an inhibitor as Man alpha 1,6Man alpha-O-Me and 10 times better than methyl alpha-D-mannoside. On the other hand, oligosaccharides containing either 1,3- or 1,6-linked mannosyl units were good inhibitors of the HHA-mannan precipitation system (6- to 20-fold more active than D-Man). These results indicate that both lectins appear to possess an extended binding site(s) complementary to at least three 1,6-linked alpha-mannosyl units. Various glycosylasparagine glycopeptides which contain alpha-1,6-Man units were retarded on the immobilized NPA column. On the other hand, those containing either alpha-1,3- or alpha-1,6-mannosyl residues were retarded on the immobilized HHA column; Man5-GlcNAc2-Asn [containing two Man alpha 1,3(Man alpha 1,6) units] bound to the HHA column. On the contrary, glycopeptides with hybrid type glycan chains were not retarded on either column. These two new lectins which differ in their fine sugar binding specificity from each other, and also from the snowdrop lectin, should prove to be useful probes for the detection and preliminary characterization of glycoconjugates on cell surfaces and in solution.

Binding, Competitive↗
PubMed1990

Isolation and characterization of a second lectin (SNA-II) present in elderberry (Sambucus nigra L.) bark.

A second lectin (SNA-II) has been isolated from elderberry (Sambucus nigra L.) bark by affinity chromatography on immobilized asialo-glycophorin. This lectin is a blood group nonspecific glycoprotein containing 7.8% carbohydrate and which is rich in asparagine/aspartic acid, glutamine/glutamic acid, glycine, valine, and leucine. Gel filtration on Superose 12 gave a single symmetrical peak corresponding to Mr, 51,000; SDS-acrylamide electrophoresis gave a single polypeptide, Mr, 30,000. Hence SNA-II appears to be a homodimer. The lectin is a Gal/GalNAc-specific lectin which is precipitated by glycoproteins containing GalNAc-terminated oligosaccharide chains (e.g., asialo-ovine submaxillary and hog gastric mucins), and by glycoproteins and polysaccharides having multiple terminal nonreducing D-galactosyl groups as occur in asialoglycophorin, asialo-laminin and Type 14 pneumococcal polysaccharide. The carbohydrate binding specificity of SNA-II was studied by sugar hapten inhibition of the asialo-glycophorin precipitation reaction. The lectin's binding site appears to be most complementary to Gal-NAc linked alpha to the C-2, C-3, or C-6 hydroxyl group of galactose. These disaccharide units are approximately 100 times more potent than melibiose, 60 times more potent than N-acetyllactosamine, and 30 times more potent than lactose. Interestingly, the blood group A-active trisaccharide containing an L-fucosyl group linked alpha 1-2 to galactose was 10-fold poorer as an inhibitor than the parent oligosaccharide (GalNAc alpha 1-3Gal), suggesting steric hindrance to binding by the alpha-L-fucosyl group; this explains the failure of the lectin to exhibit blood group A specificity.

Amino Acid Sequence↗
PubMed1990

Study on pruritus in hemodialysis patients and the antipruritic effect of neurotropin: plasma levels of substance P, somatostatin, IgE, PTH and histamine.

It has been reported that Neurotropin can markedly improve pruritus in patients undergoing hemodialysis (HD). In order to elucidate the probable causes of pruritus and the antipruritic effect of Neurotropin, various biochemical parameters in the plasma of patients before and during HD were investigated. Forty-three patients undergoing HD were divided into three groups. Eighteen patients had suffered no episode of pruritus (group A), 17 patients had on-going pruritus (group B) and the remaining 8 patients had experienced improvement of pruritus following Neurotropin treatment (group C). The mean concentration of substance P was in only B group significantly increased with HD only in B group, indicating that substance P could be one of the causes of pruritus in patients undergoing HD. Neurotropin appears to exert its antipruritic effect by lowering the level of substance P. The change in parathyroid hormone (PTH) level during HD was not significant in any of the groups, but the mean concentration of PTH in group B was higher than that of group A, indicating that PTH may also be one of the causes of pruritus.

Adjuvants, Immunologic↗
PubMed1990

[Acute nonlymphocytic leukemias with 21 trisomy as a sole anomaly].

Two cases of childhood acute nonlymphocytic leukemia (ANLL) with 21 trisomy as a sole cytogenetic change are reported. The first case was a 4-year-old boy with FAB-M5a. 47, XY, +21 was found in 7 of 12 metaphases at diagnosis and in all 15 metaphases examined at relapse 4 years and 3 months later. The second case was a 14-year-old boy with FAB-M1, all 20 cells examined showed 21 trisomy at diagnosis. His peripheral blood in remission revealed normal male karyotype. Although 21 trisomy is relatively common in ANLL of children, 21 trisomy as a sole anomaly is extremely rare, and to our knowledge, only 2 cases (19 included adult cases) have previously been reported.

Adolescent↗
PubMed1989

Snowdrop lectin.

Explore the source record for details and available documents.

Amino Acids↗
PubMed1989

Protection against pertussis by acellular pertussis vaccines (Takeda, Japan): household contact studies in Kawasaki City, Japan.

To evaluate the vaccine efficacy of an acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was performed by a questionnaire survey of secondary pertussis attacks through family contact in 146 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, acellular vaccine made by Takeda Pharmaceutical Company, which contains a high level of FHA (filamentous hemagglutinin), a low level of PT (pertussis toxin) and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand, 27 siblings immunized with Takeda's acellular vaccine were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.7%). The present study revealed an efficacy rate of 93.7% for Takeda's acellular pertussis vaccine.

Child↗
PubMed1989

[Protection against pertussis by Japanese T type acellular pertussis vaccine: household contact study in Kawasaki City].

To evaluate the vaccine efficacy of acellular pertussis vaccine which has been in clinical use in Japan since 1981, a retrospective study was made by a questionnaire from secondary pertussis attack through family contact in 149 children with pertussis diagnosed in the period from January 1981 through May 1988. In this study, Takeda's acellular vaccine which contains a high level of FHA, low level of PT and a small amount of agglutinogen, was evaluated. Secondary pertussis attacks through family contact were found in 17 of 29 siblings (58.6%) not immunized with pertussis vaccine. On the other hand of the siblings immunized with Takeda's acellular vaccine 27 were exposed to pertussis through family contact and a secondary attack was seen in only one of them (3.4%). The present study revealed an efficacy rate of 94.2% for the Takeda's acellular pertussis vaccine.

Child↗
PubMed1989

[Benign infantile mitochondrial myopathy due to reversible cytochrome c oxidase deficiency: histological and biochemical analysis].

We reported a 3-week-old girl with profound generalized weakness, requiring assisted ventilation. There was no consanguinity or family history of any neuromuscular disorders. Serum levels of GOT, GPT and CK were slightly elevated. Although the clinical manifestations mimicked those of Werdning-Hoffmann disease, a lack of the respiratory muscle involvement and the presence of high serum lactate levels suggested an underlying metabolic disorder. During the observation over the months, she gradually improved clinically and assisted ventilation was discontinued at 19 months. Muscle biopsies were performed at 4 and 19 months of age. The first biopsy showed an excessive mitochondrial aggregation and numerous ragged-red fibers. The second biopsy revealed rare ragged-red fibers. However there were definite neurogenic changes including type grouping and angulated fibers. Cytochrome c oxidase (CCO) stain was positive in less than 5% of fibers in the first biopsy but in all fibers in the second biopsy. Biochemical analysis using muscle specimens showed a decreased CCO activity; 18.5% of the control level in the first biopsy and 53.3% in the second biopsy. Immunocytochemistry showed the presence of immunologically reactive enzyme protein in both biopsies. Clinical manifestations of our patient were almost identical to those of two cases reported by DiMauro, et al (1983). The enzyme defect in this case was reversible in contrast to that in the fatal infantile form of CCO deficiency. Histochemical and biochemical bases for these differences were discussed.

Cytochrome-c Oxidase Deficiency↗
PubMed1989

Study on pruritus in hemodialysis patients and the antipruritic effect of neurotropin: plasma levels of C3a, C5a, bradykinin and lipid peroxides.

The causes of pruritus in patients undergoing hemodialysis and the mechanism of the antipruritic effect of Neurotropin, an extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus and clinically used in Japan as an analgesic and antiallergic drug, were investigated by measuring the levels of C3a, C5a, bradykinin and lipid peroxides in venous blood collected before dialysis, and at 15 min and 4 hr after starting hemodialysis. C3a increased considerably in pruritic patients compared to non-pruritic patients at 15 min after starting hemodialysis. Neurotropin significantly suppressed the C3a level and improved the condition of pruritic patients. There was no significant difference in the level of bradykinin between pruritic patients and non-pruritic patients. Therefore, bradykinin was not thought to be related to the incidence of pruritus in such patients. A tendency towards lowering of the levels of lipid peroxides in the patients' plasma by Neurotropin was also observed. It seems possible that elevation of C3a may be one of the underlying causes for the appearance of pruritus, and that Neurotropin may exert its antipruritic effect through suppression of the activation of C3 in patients undergoing hemodialysis.

Bradykinin↗
PubMed1989

Cyclosporine G and D in experimental autoimmune uveoretinitis in the rat.

Two analogs of cyclosporine A (CsA), cyclosporine G (CsG) and cyclosporine D (CsD), were compared to CsA with regards to their effects on experimental autoimmune uveoretinitis (EAU) as well as their adverse effects on renal functions. When administered daily on days 0-14 after immunization with S-antigen, CsA was the most effective of all in inhibiting EAU followed by CsG: 20-30 mg/kg/day of CsG appeared to have the same effect as 5 mg/kg/day of CsA. The effect of CsD was the least. When administered from day 7 after immunization, CsA and CsG were also effective in inhibiting the development of EAU. As for the adverse side effects, CsA was the most nephrotoxic: the toxic changes were morphologically found with doses of CsA at 10 mg/kg/day or higher. CsG and CsD were not nephrotoxic even at 30 mg/kg/day. The effects of CsG on immune responses were very similar to those of CsA. Both agents exhibited selective inhibition on the cell-mediated immune responses to S-antigen, while having no effect on antibody production.

Animals↗