PubMed Health⌕ Search

Biomedical subjects

M Shibano

Publications and source records attributed to M Shibano.

35 records · Page 2Linked to original sources
PubMed1998

Studies on the constituents of Broussonetia species. III. Two new pyrrolidine alkaloids, broussonetines G and H, as inhibitors of glycosidase, from Broussonetia kazinoki Sieb.

Two new pyrrolidine alkaloids, broussonetines G and H, were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae). Broussonetines G and H were formulated as 2 beta-hydroxymethyl-3 alpha, 4 beta-dihydroxy-5 alpha-(1-hydroxy- 6:10;10:13-diepoxytridecyl)-pyrrolidine (1) and 2 beta-hydroxymethyl-3 alpha, 4 beta-dihydroxy-5 alpha-(1-hydroxy- 5:9;9:13-diepoxytridecyl)-pyrrolidine (2), respectively, by spectroscopic methods. 1 and 2 inhibited beta-glucosidase, beta-galactosidase and beta-mannosidase.

Alkaloids↗
PubMed1997

Increased frequency of somatic mutations at glycophorin A loci in patients with aplastic anaemia, myelodysplastic syndrome and paroxysmal nocturnal haemoglobinuria.

Paroxysmal nocturnal haemoglobinuria (PNH), aplastic anaemia (AA) and myelodysplastic syndrome (MDS) are haemopoietic stem cell disorders. These disorders have some features in common, and a percentage of cases progress to acute leukaemia. We speculated that changes in gene stability are involved in the pathogenesis of these haemopoietic stem cell disorders. Therefore we investigated in vivo mutation frequencies in these disorders by erythrocyte glycophorin A (GPA) mutation assay. The assay enumerates NO or NN variant cells in 106 erythrocytes of the MN type using a flowcytometric technique. Patients undergoing chemotherapy known to be at risk of hypermutageneity were also studied. Events exceeding the 95th percentile of healthy donors (> or = 32 and 34 events, respectively for NO and NN variants) were defined as abnormal. Abnormal events in the NO variants were found in three out of seven patients undergoing chemotherapy, two out of nine patients with AA, two out of seven patients with MDS, and four out of nine patients with PNH. Abnormal events in the NN variants were found in three out of seven patients undergoing chemotherapy, two out of nine patients with AA, one out of seven patients with MDS, and two out of nine patients with PNH. These results suggest that not only PIG-A, but also other genes including the GPA gene, are hypermutable in haemopoietic stem cell disorders, and that mutagenic pressure and/or gene instability can contribute to the pathogenesis of these disorders.

Adult↗
PubMed1997

Studies on the constituents of Broussonetia species. II. Six new pyrrolidine alkaloids, broussonetine A, B, E, F and broussonetinine A and B, as inhibitors of glycosidases from Broussonetia kazinoki Sieb.

Six new pyrrolidine alkaloids called broussonetine A, B, E, F, and broussonetinine A and B were isolated from the branches of Broussonetia kazinoki Sieb. (Moraceae). Broussonetine A, B, E and F were formulated as 2 beta-hydroxymethyl-3 beta-hydroxy-5-alpha- (10-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-beta-D-glucopyranoside (1), 2 beta-hydroxymethyl-3 beta-hydroxy-5 alpha-(9-oxo-13-hydroxytridecyl)-pyrrolidine-4-O-beta-D-glucopy ran oside (2), 2 beta-hydroxymethyl-3 alpha,4 beta-dihydroxy-5 alpha-(1,13-dihydroxy-10-oxo-tridecyl)-pyrrolidine (3), and 2 beta-hydroxymethyl-3 alpha,4 beta-dihydroxy-5 alpha-(1,13-dihydroxy-9-oxo-tridecyl)-pyrrolidine (4), respectively. Broussonetinine A and B (5 and 6) were also isolated and identified as the aglycones of 1 and 2. 3 and 4 exhibited a strong inhibition of alpha-glucosidase, beta-glucosidase, beta-galactosidase and beta-mannosidase, while 5 and 6 showed a strong inhibition of beta-galactosidase and alpha-mannosidase.

Alkaloids↗
PubMed1996

Analysis of PIG-A gene in a patient who developed reciprocal translocation of chromosome 12 and paroxysmal nocturnal hemoglobinuria during follow-up of aplastic anemia.

The relationships between paroxysmal nocturnal hemoglobinuria (PNH), aplastic anemia (AA), and myelodysplastic syndrome (MDS) are not clear. Here we describe a patient, J20, who developed a reciprocal translocation of chromosome 12 and PNH during follow-up of AA. All metaphases in CD59-deficient bone marrow mononuclear cells had the translocation, whereas none of the CD59-deficient cells had it, indicating that the PNH clone coincided with a cell population bearing the chromosomal aberration. We found a somatic single-base deletion mutation in the PIG-A gene of this patient's peripheral blood cells. This is the first patient with PNH with a PNH clone containing a chromosomal translocation.

Adult↗
PubMed1996

Studies on the constituents of Cimicifuga species. XIX. Eight new glycosides from Cimicifuga simplex Wormsk.

Eight new glycosides were isolated from Cimicifuga simplex (Ranunculaceae), and their structures were determined to be 23-O-acetyl-7-8-didehydroshengmanol-3-O-alpha-L-arabinopyranosi de (1), 24-epi-24-O-acetyl-7,-8- didehydrohydroshengmanol-3-O-beta-D-galactopyranoside (2), 7,8-didehydrocimigenol-3-O-beta-D-galacytopyranoside (3), 24-epi-24-O-acetylhydroshengmanol-3-O-beta-D-galactopyranoside (4), cimigenol-3-O-beta-D-galactopyranoside (5), 25-O-methylcimigenol-3-O-beta-D-galactopyranoside (6), 25-O-acetylcimigenol-3-O-beta-D-galactopyranoside (7) and 25-O-acetylcimigenol-3-O-beta-D-glucopyranoside (8). Genuine aglycones were obtained by the hydrolysis of 1--7 with lactase F[Amano] and of 8 with cellulase T[amano]4. Acerinol was prepared from 7,8-didehydrocimigenol and showed antilipemic effects.

Animals↗
PubMed1996

[Large granular lymphocyte leukemia].

Large granular lymphocyte leukemia (LGLL) is defined as clonal proliferation of LGLs in peripheral blood. The following studies were conducted to address some issues in chronic LGLL. (1) Chronic LGLL is characterized by the indolent course, and the diagnosis of leukemia is difficult in such patients as those without distinct organomegaly and/or any evidence of monoclonality. We performed immunohistological studies in a patient with persistent NK lymphocytosis. No organomegaly had been seen in the patient during a three-year-observation, who died from cerebrovascular accident. The autopsy findings revealed multi-organ infiltration including spleen, liver, bone marrow, lymph nodes and lung. These findings suggest that the cells of chronic LGLL have infiltrative capacity characteristic of malignant cells. (2) Lymphocytosis in chronic LGLL is usually stable for a long period. We found that both T- and NK-LGLL cells strongly expressed CD95, an apoptosis related protein. Anit-CD95 did not induce apoptosis, but suppressed proliferation induced by IL-2 or anti-CD3. These results suggest that CD95-CD95 ligand system is involved in the slow cell growth characteristic of chronic LGLL. (3) CD4+CD8+ double positive (DP) cases are rarely seen in LGLL, and the physiologic counterpart of the leukemic cells has not been determined yet. We found that the DP-LGLL had alpha alpha type in the CD8 subunit and did not express RAG-1, these findings being characteristic of peripheral T cells. We also found that they expressed IL-4 mRNA and secreted IL-4 on activation. These results strongly suggest that DP-T-LGLL represents an expansion of a rare subset of peripheral DP-T cells, possibly derived from IL-4 activated CD4 single positive T cells.

Aged↗
PubMed1994

Relationship between hemolytic activity and adsorption capacity of aluminum hydroxide and calcium phosphate as immunological adjuvants for biologicals.

Aluminum hydroxide (Al) and calcium phosphate (Ca) gels have been used as vaccine adjuvants for many years. We investigated mechanism of the hemolytic activities of both adjuvant materials. The hemolytic activity of each gel depended on the gel dose. The adsorption capacities and the hemolytic activities of both adjuvants decreased as the concentration of phosphate increased in a gel-washing solution. A positive correlation between the hemolytic activity and the adsorption capacity was found in Al-gel. A disruptive effect of Ca-gel on membrane of erythrocytes was shown by electron microscopy. Ca-gel required more than 10 times as much pre-adsorbed ovalbumin as did Al-gel to inhibit the hemolysis. These results suggest that the hemolytic activity of both adjuvant materials depended mainly on the adsorption ability, and it may be useful to control the adsorption ability of adjuvants to reduce their hemolytic activity.

Adjuvants, Immunologic↗
PubMed1993

Hairy cells from hairy cell leukemia patients presenting with pronounced polyclonal hypergammaglobulinemia secrete a factor enhancing IgG synthesis.

We studied the immunological function of hairy cells from hairy cell leukemia (HCL) patients presenting with pronounced polyclonal hypergammaglobulinemia (PPH). Hairy cell conditioned medium (HCCM) obtained from HCL patients with PPH augmented IgG production by normal peripheral blood mononuclear cells in a dose-dependent fashion, while HCCM from patients without PPH had no effect on IgG production. HCCM from the patients with PPH failed to enhance IgG synthesis by T cell-depleted mononuclear cells. Separation of T and B cells by a 0.4-microns membrane as well as monoclonal antibodies to HLA-DR and CD3 molecules prevented HCCM-dependent IgG synthesis. No B cell growth factor activity, interleukin-1, or interleukin-6 was detected in the HCCM. On examination by fractionation of the HCCM, IgG-inducing activity was detected in the fractions of 5000 to 8000 Da. These results indicate that hairy cells from HCL patients with PPH secrete a factor inducing IgG synthesis, and that the induction of IgG synthesis by the factor requires T-B cell interactions involving T cell receptor/CD3 complex and MHC class II antigens. This factor may play an important role in the development of PPH.

B-Lymphocytes↗
PubMed1993

A HTLV-I carrier who showed various symptoms and antibodies of autoimmune diseases.

We report a 37-year-old female HTLV-I carrier with complicating primary biliary cirrhosis (PBC) and mixed connective tissue disease (MCTD). Serum anti-HTLV-I antibody titer was x256. Flower cells (4.5%) were found in the peripheral blood. Southern blot analysis showed no clonal integration in peripheral blood lymphocyte (PBL) DNA. Polymerase chain reaction showed the HTLV-I genome in PBL DNA. As cholestatic liver dysfunction and serum titer of anti-mitochondrial antibody were found, a clinical diagnosis of PBC was made. This patient later developed MCTD. These diseases responded well to prednisone. The pathogenetic relationship of HTLV-I infection with various autoimmune diseases is discussed.

Adult↗
PubMed1990

Association of protein tyrosine phosphorylation with B cell differentiation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA).

We have assessed whether tyrosine protein kinase (TPK) is involved in B cell differentiation. In vitro phosphorylation of an endogenous substrate in B cell leukemias showed that leukemic B cells at different stages of differentiation had specific endogenous substrates in tyrosine phosphorylation as well as distinct TPK activity. To clarify the relationship between TPK and the process of B cell differentiation, we studied protein tyrosine phosphorylation in two kinds of leukemic B cells, which showed distinct responses to TPA (12-O-tetradecanoylphorbol-13-acetate) in B cell differentiation. TPA-treated leukemic B cells from patients with B cell chronic lymphocytic leukemia (B-CLL) differentiated into cytoplasmic immunoglobulin (clg)+ plasmacytoid cells, while TPA-treated leukemic B cells from patients with hairy cell leukemia (HCL) did not differentiate into clg+ cells, but showed a peculiar morphological change, spreading. Untreated B-CLL cells and HCL cells showed similar TPK activities and tyrosine protein phosphorylation. When treated with TPA, enhanced phosphorylation was seen in B-CLL cells, while a clear reduction in phosphorylation was found in HCL cells. However, using 4-hydroxycinnamide derivatives which reduce TPK activity, we found that only the reduction of TPK activity did not lead HCL cells to spreading. These data suggest that protein tyrosine phosphorylation and/or dephosphorylation might be involved in B cell differentiation, but only the change of TPK activity in HCL cells is not sufficient to induce effects.

B-Lymphocytes↗
PubMed1988

The expression of the p75 subunit of interleukin 2 receptor in Tac negative leukemic cells of two patients with large granular lymphocytic leukemia.

The expression of interleukin 2 receptor (IL-2R) on leukemic cells of natural killer (NK) and T cell lineages in two patients with large granular lymphocytic (LGL) leukemia was examined. The p55 Tac IL-2R was not detected by the indirect immunofluorescence method and it did not participate in the IL-2 binding to the surface of these cells. However, these leukemic cells proliferated in a IL-2 dose-dependent manner and expressed p55. A p75 IL-2 receptor (IL-2-R) subunit was detected on the LGL leukemic cells of both NK and T lineages in a crosslink assay. Thus, it is suggested that the primary signal of IL-2 is mediated by the p75 alone. A study of the inhibitions of the proliferative response of LGL leukemia cells by anti-Tac revealed that both p75 and secondarily induced p55 are required for the cell proliferation.

Aged↗
PubMedDate not supplied

Local tissue irritating effects and adjuvant activities of calcium phosphate and aluminium hydroxide with different physical properties.

Effects of calcium phosphate and aluminium hydroxide adjuvants with different physical properties were examined in guinea pigs for local histopathological reactions, electron-microscopical changes of macrophages and adjuvanticity on total IgG antibody response to subcutaneously administered ovalbumin (OVA) and tetanus toxoid (TT). Calcium phosphate gel (Ca-gel) induced active inflammatory reactions consisting of neutrophils (pseudoeosinophils) and foamy macrophages associated with many multinuclear giant cells for at least 4 weeks. Aluminium hydroxide gel (Al-gel) also elicited granulomatous inflammatory reactions consisting mainly of macrophages with foamy cytoplasm, small lymphocytes and giant cells at the injection sites for up to 8 weeks or longer. Severity of local tissue irritation due to calcium phosphate gel (Ca-gel) was similar to that due to Al-gel except for the duration of the inflammatory reactions. Calcium phosphate suspension (Ca-sus)-induced local reactions completely ceased by the 4th week, while aluminium hydroxide suspension (Al-sus)-induced reactions were seen up to the 8th week. Electron-microscopical observations showed that both Al-gel and Al-sus caused damage of macrophages. The adjuvant activity of Al-gel for OVA or TT was significantly stronger than that of any other adjuvant material, whereas those of Ca-gel and Ca-sus were not seen at a dose of 3 mg calcium phosphate per millilitre. Al-sus-TT at a dose of 3 mg aluminium hydroxide per millilitre induced very low levels of antibody. These results suggest that calcium phosphate adjuvant may not be an useful alternative to Al adjuvant.

Adjuvants, Immunologic↗