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Biomedical subjects

S Furusawa

Publications and source records attributed to S Furusawa.

At least 55 records · Page 3Linked to original sources
PubMed1998

Development of maternal IgG-free chick obtained from surgically bursectomized hen.

IgG-free eggs and chicks were developed, so as to study the role of maternal IgG in the development of the immune system. Surgical bursectomy on the 18th day of incubation deprived chickens of B cells and eliminated IgG synthesis. Bursectomized chickens are usually dead before sexual maturity under conventional conditions. When surgically bursectomized chickens were housed in an isolated clean room and antibiotics were administered to them, they could survive to sexual maturity. Finally, we succeeded in obtaining IgG-free fertilized eggs and maternal IgG-free chicks from surgically bursectomized hens. The amount of yolk IgG in IgG-free eggs was one-ten thousandth less than that in normal eggs. The level of IgM in the serum of maternal IgG-free chicks reached six times higher than that of normal chicks 5 days after hatching.

Animals↗
PubMed1998

Mature and immature myeloid cells decrease the granulocyte colony-stimulating factor level by absorption of granulocyte colony-stimulating factor.

We studied the effects of polymorphonuclear neutrophils (PMN) and immature myeloid cells on the granulocyte colony-stimulating factor (G-CSF) level in vitro to better understand the regulatory mechanisms of neutropoiesis. Intact normal PMN decreased the G-CSF level after incubation with recombinant human (rh) G-CSF in a time- and dose-dependent manner. The percent reduction decreased as the concentration of rhG-CSF increased. However, the cell-free PMN-conditioned medium (PMN-CM) did not decrease the G-CSF level. The intact PMN also decreased the granulocyte-macrophage (GM)-CSF level after culture with rhGM-CSF, but did not affect the monocyte (M)-CSF level after culture with rhM-CSF. Normal bone marrow (BM) immature neutrophilic cells and G-CSF-dependent acute myeloid leukemic cells (OCI/AML la) also decreased the G-CSF level, whereas K-562 cells, which have no detectable G-CSF receptors, did not affect it. Phenylarsine oxide (PhAsO), an inhibitor of endocytosis of ligand receptor complex, abrogated this decreasing effect of intact PMN and OCI/AML la cells. These findings suggest that mature and immature myeloid cells negatively regulate neutropoiesis by, at least in part, decreasing the G-CSF level probably through receptor-mediated continual absorption and metabolism of G-CSF.

Absorption↗
PubMed1998

Detection of chimaeric transcripts of the immunoglobulin heavy chain and BCL6 genes by reverse-transcriptase polymerase chain reaction in B-cell non-Hodgkin's lymphomas.

T(3;14)(q27;q32) is frequently detected in B-cell non-Hodgkin's lymphomas, especially the diffuse large cell type and the follicular type. The BCL6 gene encoding a putative transcriptional factor which resides on 3q27 rearranges to the immunoglobulin heavy chain (IgH) gene on 14q32 in this chromosomal translocation. The upstream regulatory region of the BCL6 gene is replaced by the IgH gene. Deregulation of the BCL6 gene may contribute to tumourigenesis of these diseases. The rearrangement between the IgH and BCL6 genes generates chimaeric transcripts in which the joining (J) region of the IgH gene fuses to exon 3 of the BCL6 gene. We established a method to detect these chimaeric transcripts by reverse transcriptase polymerase chain reaction (RT-PCR) using the consensus sequence of the J region and the sequence of exon 3 of the BCL6 gene as primers. Using the semi-nested RT-PCR method and a cell line carrying t(3;14)(q27;q32), we detected one lymphoma cell among 10,000 background cells. We detected these chimaeric transcripts in two out of 13 clinical samples by this method. This method can detect t(3;14)(q27;q32) easily, whereas this alteration is frequently overlooked by routine karyotype analysis. Since this technique is sensitive enough to detect a small number of lymphoma cells with this genetic abnormality, it could be employed to detect contaminating lymphoma cells in bone marrow and peripheral blood and minimal residual diseases.

Base Sequence↗
PubMed1998

Chicken monoclonal antibodies against synthetic bovine prion protein peptide.

Chicken monoclonal antibodies (mAbs) were developed against bovine prion protein (PrP) peptide. Chickens immunized with bovine PrP peptide B204 (amino acid residues 204-220) coupled to keyhole limpet hemocyanin produced specific antibodies to the peptide as determined by an enzyme-linked immunosorbent assay (ELISA) using the B204 peptide coupled to ovalbumin as target antigen. From a fusion experiment using the chicken fusion partner cell line MuH1 and immune spleen cells, 19 mAbs reactive with B204 were generated. These mAbs were subdivided into five groups based on competitive ELISA using B204 and four 10-amino acid peptides. These five groups included all combinations expected based on comparison of amino acid sequences among the five species, bovine, mouse, human, sheep and hamster, examined. These results indicate that the chicken mAb system is a suitable technique for immunological analysis of PrP in mammals.

Amino Acid Sequence↗
PubMed1998

Cepharanthine inhibits proliferation of cancer cells by inducing apoptosis.

Cepharanthine, a biscoclaurine alkaloid extracted from Stephania cepharantha Hayata was examined for a possible apoptosis-inducing effect in murine P388 doxorubicin-sensitive (P388/S) and -resistant (P388/DOX) cells. A significant increase in LDH release from cells was observed after P388/S and P388/DOX cells had been exposed to cepharanthine for 24 h. Cepharanthine (10 micrograms/ml) markedly induced apoptosis in resistant cells after 6 h and 24 h. By the means of agarose electrophoresis the DNA ladder was detected in cell lines treated with cepharanthine for 24 h. Cepharanthine (1-10 micrograms/ml) also induced the production of reactive oxygen species in P388/DOX cells, while no such cepharanthine-induced increase in reactive oxygen species was observed in P388/S cells. Flow cytometry analysis showed a high level of Fas-antigen expression in P388/DOX cells treated with cepharanthine. Furthermore, we found that the inhibitition of DNA and protein synthesis caused by cepharanthine (10 micrograms/ml) was more significant in resistant cells than in sensitive cells. Cepharanthine had no effect on the GSH content of P388/S and P388/DOX cells. Our experimental results suggest that cepharanthin can induce apoptosis both in P388/S and P388/DOX cells, especially in the latter. Apoptosis induced by cepharanthine may be implicated in the production of reactive oxygen species and Fas-antigen expression in tumor cells.

Alkaloids↗
PubMed1998

[Hodgkin's disease].

Explore the source record for details and available documents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

IgE memory B cells identified by the polymerase chain reaction.

The existence of memory B cells for IgE was investigated using spleen cells harvested from mice primed and boosted with dinitrophenylated keyhole limpet hemocyanin. Using the polymerase chain reaction, it was found that mRNA for IgE was already demonstrable in spleen cells taken 1 day after boost. Spleen cells taken from mice 1 day after boost and cultured in vitro without the addition of antigen also produced anti-dinitrophenylated (DNP) IgE antibody. In contrast, mRNA for IgE in spleen cells from mice primed 4 weeks previously, but not boosted, was not demonstrable. Anti-DNP IgE was not produced in cultures of spleen cells from mice primed but not boosted. As mRNA for IgE was demonstrable already 1 day after boost we concluded that mice produce memory B cells not only for IgM, but also for IgE specific for the immunizing antigen.

Adjuvants, Immunologic↗
PubMed1997

Identification of surface molecules on eosinophils and lymphocytes in blood from patients with eosinophilia.

Surface molecules on eosinophils and lymphocytes in blood from patients with hypereosinophilic syndrome (HES), Kimura's disease and normal volunteers were examined. In all 3 patients with HES, CD54-positive eosinophils were increased and in some patients with HES and Kimura's disease HLA-DR-positive eosinophils were increased. Additionally, CD11b-positive, CD16-positive, CD25-positive, CD54-positive, CD69-positive and HLA-DR-positive lymphocytes were increased in some of these patients.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1997

Potentiation of pirarubicin activity in multidrug resistant cells by rifampicin.

The effect of the anti-tuberculosis drug rifampicin on pirarubicin activity was investigated in multidrug-resistant cells overexpressing P-glycoprotein. Rifampicin increased the sensitivity of pirarubicin to anthracycline-resistant mouse leukemic P388 cells and significantly enhanced the cytotoxicity and intracellular accumulation of pirarubicin in resistant cells, but had no effect in parent cells. By contrast, two other rifamycins, rifamycin B and SV, had no effect on pirarubicin accumulation in resistant cells. Rifampicin also enhanced pirarubicin-induced apoptosis and G2/M blockade on the cell cycle in resistant cells. These results show that rifampicin enhances the cytotoxic action of pirarubicin in resistant cells, at least partly via the inhibition of cellular pirarubicin efflux.

Animals↗
PubMed1996

Immunoglobulin gene hyperconversion ongoing in chicken splenic germinal centers.

It has been believed that the peripheral lymphocytes in chickens proliferate by self-renewing amplification of the preimmune repertoire generated in bursa. We amplified rearranged immunoglobulin variable (V) region genes from the single germinal centers induced by immunization. The sequence analysis of these genes revealed that most were derived from distinct B-cell clones which expanded locally, generating somatic antibody mutants at a high rate. Somatic hypermutations included unlinked base changes and the linked base modifications interpreted as unidirectional transfer of sequences from V region pseudogenes. This finding demonstrates the ongoing post-bursal diversification of B-cells in splenic germinal centers by templated gene conversion as well as untemplated point mutations.

Amino Acid Sequence↗
PubMed1996

Vesnarinone-induced granulocytopenia: incidence in Japan and recommendations for safety.

Vesnarinone (OPC-8212) is a new positive inotropic agent that augments myocardial contractility. A recent multi-center randomized trial in the United States demonstrated that 60 mg/day of vesnarinone significantly reduced morbidity and mortality and improved quality of life in patients with symptomatic chronic heart failure. Vesnarinone, however, is also known for its propensity to cause granulocytopenia. In search of effective safety measures against this side effect, data have been collected in Japan as part of the post-marketing surveillance of this drug. This article reviews the results of this post-marketing surveillance and other works available to date, including an illustrative case report, and presents measures that should be taken with regard to safety during treatment with vesnarinone. Vesnarinone-induced granulocytopenia has appeared in relatively early stages of vesnarinone therapy, and characteristically results in a rapid decrease in granulocyte count. Hematologic monitoring should be performed at least once a week during the initial 16 weeks of vesnarinone therapy. Granulocyte colony-stimulating factor may contribute to recovery from severe granulocytopenia, although it should be used carefully because of its potential to cause adult respiratory distress syndrome.

Adult↗
PubMed1996

Preferential inhibitory effect of soluble factor(s) in human bone marrow stromal cells on proliferation of K562 leukemia cells versus normal myeloid progenitor cells.

We examined the effect of diffusible factors generated during the culture of the KM102 stromal cell line as well as in long-term bone marrow culture (LTBMC) on K562 leukemia cells, with respect to proliferation of clonogenic cells as well as total cells, and compared it with the effect on normal myeloid progenitors (CFU-GM). Proliferation of K562 cells plated in diffusion chambers was inhibited by coculture for 3-5 days in the fluid phase of stromal cell cultures or stromal cell-conditioned medium (CM), while CFU-GM proliferation was not inhibited under the same culture conditions. The inhibitory action was not attributed to the exhaustion of nutrients or growth promoting factors such as stem cell factor. These findings suggest that bone marrow stromal cells secrete diffusible molecule(s) which exert a preferential inhibitory effect on K562 leukemic cells vs. normal CFU-GM. Neutralization with antibodies against hematopoiesis-inhibiting cytokines such as TGF-beta 1, IFN-gamma, MIP-1 alpha and IL-4 which were detected in stromal cell-CM, failed to abrogate the inhibitory effect of KM102-CM on K562 cells. IL-1, TNF-alpha, IFN-alpha and lipopolysaccharides, known as stimulators of various cytokines from stromal cells, could not enhance the inhibitory activity. Further characterization of the factors may have implications for the treatment of leukemias.

Bone Marrow↗
PubMed1996

The enhancing effect of tumour necrosis factor-alpha on oxidative stress in endotoxemia.

The enhancing effect of tumour necrosis factor-alpha (TNF-alpha) on oxidative stress with or without a sublethal dose of endotoxin was examined. The mortality of mice treated with recombinant human TNF-alpha (1 x 10(4) units/mouse, intravenously) and endotoxin (0.01-1 mg/kg, intraperitoneally) was dependent on the dose of endotoxin. The liver lipid peroxide level, superoxide anion generation and serum lactate dehydrogenase activity, especially serum lactate dehydrogenase-5 isozyme leakage, in mice 2-4 hr after administration of recombinant human TNF to endotoxin-pretreated mice (0.5 mg/kg, intraperitoneally) were markedly higher than in those without endotoxin, whereas the administration of recombinant human TNF significantly decreased the non-protein sulfhydryl level, superoxide dismutase and glutathione peroxide activities in the liver of endotoxin-injected mice compared with those in mice treated with recombinant human TNF or endotoxin alone. Furthermore, findings clearly demonstrated that J774A.1 cells stimulated with recombinant human TNF (1 x 10(4) units/ml) can effectively produce nitric oxide in the presence of endotoxin, and the production was dependent on the dose of endotoxin (0.01-10 micrograms/ml). The level of lipid peroxide in mice 4 hr after administration of recombinant human TNF and lead acetate (50 mg/kg, intravenously) was markedly higher than that in the mice treated with recombinant human TNF alone. By contrast, injection of polymyxin-B (20 mg/kg, intraperitoneally, an anti-endotoxin drug) markedly decreased the lipid peroxide level in the liver of the mice treated with recombinant human TNF and lead acetate. These findings suggest that the oxidative stress caused by TNF occurs as a enhancing effect of endotoxin or by bacterial translocation from the intestinal gut under reduction of reticuloendothelial system function in various disease states, and that the effect of TNF may cause a marked increase of toxicity of oxidative stress by endotoxin.

Animals↗
PubMed1996

Eosinophils negatively regulate eosinophilopoiesis by decreasing IL-5 levels.

The effect of mature eosinophils on eosinophilopoiesis was studied. Mature eosinophils decreased the interleukin-5 (IL-5) level after incubation with IL-5 and suppressed IL-5 release from non-adherent mononuclear cells. These findings suggest that eosinophils negatively regulate eosinophilopoiesis by decreasing the IL-5 level.

Eosinophilia↗