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Biomedical subjects

M Kurimoto

Publications and source records attributed to M Kurimoto.

At least 253 records · Page 14Linked to original sources
PubMed1993

Suppression of murine IgE responses with ovalbumin-pullulan conjugates: comparison of the suppressive effect of different conjugation methods and different molecular weights of pullulan.

Ovalbumin (OVA)-pullulan conjugates were made using four different conjugation methods and eight different molecular weights of pullulan ranging from 4,200 to 600,000. Pretreatment of mice by the administration of conjugates made by using cyanulic chloride or cyanogen bromide and pullulan of molecular weight 40,000 or more, anti-OVA IgE antibody response was suppressed completely and anti-OVA IgM and IgG antibody response was enhanced. In contrast, by the administration of conjugates made by using an oxidation or thiol activation method, only partial suppression of anti-OVA IgE antibody response was achieved and no enhancement of anti-OVA IgM and IgG antibody production was observed.

Animals↗
PubMed1993

Enzymatic synthesis of a novel trisaccharide, glucosyl lactoside.

Cyclomaltodextrin glucanotransferase from Bacillus stearothermophilus produced a series of oligosaccharides by the transglycosylation reaction with cyclomaltohexaose as a glycosyl donor and D-lactose as its acceptor. The content of oligosaccharide A as the main transfer product was 22.1% of the total sugar. The content was increased to 34.1% by hydrolysis with glucoamylase. Oligosaccharide A was isolated by column chromatography and crystallized. By chemical and enzymatic analyses, oligosaccharide A was found to be a novel non-reducing trisaccharide; O-beta-D-galactopyranosyl-(1-->4)-O- beta-D-glucopyranosyl alpha-D-glucopyranoside.

Carbohydrate Sequence↗
PubMed1993

Characterization of 17 human immunodeficiency virus-1 carrier cell lines with T cell, myelomonocyte, or megakaryocyte lineages.

Of 29 hematopoietic cell lines tested for susceptibility to human immunodeficiency virus (HIV)-1HTLV-IIIB infection, all CD4+ cell lines became infected. Continuous culturing of infected cell lines resulted in nine HIV-1 carrier cell lines, including, for the first time, an HIV-1 carrier megakaryoblastic cell line, MEG-01/HIV. The immunophenotypic profiles of a total of 17 HIV-1 carrier cell lines (nine newly and eight previously established cell lines) were compared with their respective parental noninfected cell lines. Except for total absence of CD4 expression, the expression of other antigens was variable among the 17 HIV-1 carrier cell lines. Persistent and consistent replication of infectious HIV-1 was detected in all of them in varying quantities. The great variability observed in both the altered marker expression, with respect to that of the noninfected parental cell lines, and in the quantities of persistently produced infectious HIV-1 was, nevertheless, specific to the individual cell lines. Furthermore, the present study demonstrates that there is no apparent correlation in the quantity of HIV-1 produced to either T cell, myelomonocytic cell, or megakaryocytic cell types. Instead, the results suggest that a particular interaction between HIV-1 and individual clonal cell lines may provide insight into the extremely complex immune dysregulation associated with the pathogenesis of acquired immune deficiency syndrome. Thus, the 17 HIV-1 carrier cell lines of diverse origin presented here provide valuable and unique models for further understanding acquired immune deficiency syndrome pathogenesis at the cellular and molecular levels.

Adolescent↗
PubMed1993

Analysis of the site on a TNF-alpha molecule which affects type II TNF receptor binding in human cells.

The epitope region on the TNF-alpha molecule recognized by monoclonal antibody (mAb) 3-D-6, which neutralizes the cytotoxic activity on murine LM cells, has been determined as Gly24-Gln-Leu-Gln-Trp-Leu-Asn-Arg31. To examine whether this region participates in TNF receptor binding in human cell lines, four kinds of TNF-alpha mutants (Gln25 --> Glu, Gln27 --> Glu, Leu29 --> Val, and Arg31 --> Ser) were prepared using site-directed mutagenesis. One mutant, mRS31, which has a nonconserative mutation at position 31 (Arg --> Ser), showed markedly reduced binding in U-937 cells and in HL-60 cells compared with the wild-type recombinant TNF-alpha (rTNF-alpha). These two cell lines have been reported to have both type I and type II TNF receptors. mRS31 also showed reduced cytotoxicity on U-937 cells. Another mutant, mLV29, which has a conservative mutation at position 29 (Leu --> Val), showed, to a lesser extent, reduced binding in U-937 cells and HL-60 cells and reduced cytotoxic activity in U-937 cells. However, all four TNF-alpha mutants showed a similar binding in HEp-2 cells and in HeLa cells, which have been reported to have only the type I TNF receptor. These results suggest that Leu29 may be involved in direct contact with the type II receptor and that the nonconservative mutation at position 31 may induce a local conformational change in the site involved in type II TNF receptor binding.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

[Immunological and physicochemical properties of Cry j II, the second major allergen of Japanese cedar pollen (Cryptomeria japonica)].

Cry j II, the second major allergen of Japanese cedar (sugi, Cryptomeria japonica) pollen was examined for the allergenicity by intradermal test and RAST. Nineteen of the 25 allergic patients examined, showed positive reaction to the Cry j II. Contents of Cry j II in the extracts of the pollen collected in various regions from 1977 to 1991 showed yearly variation ranging from 2.9 to 14 mg/100 g pollen, whereas the amount of Cry j I in the extract was comparatively stable at about 35 mg/100 g pollen. Physicochemical treatments of Cry j I and Cry j II suggested that specific human IgE antibodies and some mAbs bind to conformational epitopes which are denatured and destroyed by certain treatments.

Allergens↗
PubMed1992

Activation of mouse macrophages by in vivo and in vitro treatment with a cyanine dye, lumin.

The cyanine photosensitizer, lumin, is a potent macrophage activating agent: 4 days after administration of small amounts of lumin to mice (20-40 ng mouse-1), peritoneal macrophages exhibited a greatly enhanced Fc-mediated ingestion activity; higher doses (more than 3000 ng mouse-1) did not have this effect. The in vitro photodynamic activation of macrophages in mouse peritoneal cells exposed to white fluorescent light (3 J m-2 s-1) was also studied in media containing various concentrations of lumin. A short light exposure (45 J m-2) with 10 ng lumin ml-1 produced a maximum ingestion activity of macrophages. Lumin has absorption peaks at 670 and 760 nm. Therefore we designed experiments in which peritoneal cells were exposed to a red fluorescent light (emission, 660 nm; 0.5 J m-2 s-1). In a medium containing 3 ng lumin ml-1 with 7.5 J m-2 of red light, a markedly enhanced ingestion activity of macrophages was observed. The photodynamic treatment of peritoneal macrophages alone did not stimulate phagocytic activity, but the photodynamic treatment of a mixture of non-adherent (B and T) cells and macrophages resulted in a greatly enhanced ingestion activity of macrophages. Thus non-adherent cells are required for the photodynamic activation of macrophages, implying that an activating factor is generated within the non-adherent cells and transmitted to the macrophages. This hypothesis was confirmed by the observation that co-cultivation of photodynamically treated non-adherent cells with untreated macrophages resulted in a greatly enhanced ingestion capacity.

Animals↗
PubMed1992

A new highly sensitive immunoassay for cytokines by dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA).

Non-isotopic immunoassays for human tumor necrosis factor alpha (TNF alpha) and human interleukin-6 (IL-6) were established by employing the dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) system based on the time-resolved fluoroimmunoassay technique with europium-labeled antibody. Compared to enzyme-linked immunosorbent assays and bioassays, the sensitivity and range of measurement were significantly increased by applying the DELFIA systems to TNF alpha and IL-6. TNF alpha was measurable from 100 fg/ml to 10 ng/ml with the TNF alpha-DELFIA and IL-6 was measurable from 100 fg/ml to 1 ng/ml with the IL-6-DELFIA.

Antibodies, Monoclonal↗
PubMed1992

Antigenic analyses of Sugi basic protein by monoclonal antibodies: I. Distribution and characterization of B-cell-tropic epitopes of Cry j I molecules.

Using 23 monoclonal antibodies raised against Sugi basic protein (SBP, major allergen of Japanese cedar pollen), composed of Cry j I and Cry j II, analyses of B-cell-tropic epitopes of Cry j I were performed. The following results were obtained. (1) As far as the mAbs were used, no major cross-reactive determinants were detected between Cry j I and Cry j II molecules. (2) 21 of the 23 mAbs were specific for Cry j I, and the anti-Cry j II mAbs were classified into four groups by their fine specificities, suggesting that Cry j I bears at least four antigenic determinant regions. (3) Cry j I molecules were found to take a monomeric form in solution and to display no repeating antigenic epitopes on their surfaces. (4) Some of the determinants seemed to be located in the interior of a Cry j I molecule, and when the Ag is coated on a plastic plate, the determinants become exposed on its surface. (5) Binding of human IgE antibodies to Cry j I and Cry j II was blocked by some of the obtained mAbs, suggesting that these epitopes recognized by the mAbs might have an important role in human allergic response against the cedar pollen.

Allergens↗
PubMed1992

Antigenic analyses of Sugi basic protein by monoclonal antibodies: II. Detection of immunoreactive fragments in enzyme-cleaved Cry j I.

The 4 anti-Cry j I mAbs showing an epitope specificity different from each other, 046, 029, 026 and 027, were selected to analyze the structure of the antigenic determinant for each mAb on a Cry j I molecule. Immunoreactive fragments in enzyme-cleaved Cry j I were detected by means of the adsorption on the mAb column and of the binding to the mAbs on Elisa. The mAb 026 was found to be reactive to the fragments containing a Cry j I N-terminal region obtained by V8 protease or pepsin digestion, but not to those by lysylendopeptidase digestion. The mAb 027 was found to be capable of binding to the fragments containing a linear structure of Asn-Ala-Gly-Val-Leu-Thr-Cys-Ser-Leu-Ser-Lys, which were generated by V8 protease, lysylendopeptidase or pepsin digestion. Furthermore, the synthetic peptide Asn-Ala-Gly-Val-Leu-Thr-Cys-Ser- Leu-Ser-Lys-Arg could bind to 027, but not to 026, and could inhibit the binding of 027 to Cry j I or to its immunoreactive fragments. No fragments capable of reacting to the mAbs 046 and 029 could be found in this study, suggesting that 046 and 029 recognize a conformationally constituted epitope of Cry j I molecule which is destroyed by enzymatic cleavage. The epitope recognized by the mAbs 027 or 026 was found to be located in conformationally hidden parts of the molecule which was exposed to react to the mAbs only after the physicochemical or enzymatic treatment.

Allergens↗
PubMed1992

Early phase II study of interferon-alpha and tumor necrosis factor-alpha combination in patients with advanced cancer.

Synergistic enhancement of anti-tumor effects through the combined use of natural human interferon-alpha (nHuIFN-alpha) and natural human tumor necrosis factor-alpha (nHuTNF-alpha) enabled us to decrease the effective dose of each cytokine and consequently to reduce side effects. One hundred and twenty patients with advanced or recurrent solid cancer were entered in the trial from April 1985 to January 1988, of whom 112 patients were evaluable. A mixture of nHuINF-alpha and nHuTNF-alpha was injected intravenously as the maintenance dose 1 x 10(6)U or more/day for over 8 weeks. There was no response in 40 patients injected with the maintenance dose of 1 x 10(6)U/day, but of 72 patients receiving more than 2 x 10(6)U/day (10 micrograms of nHuIFN-alpha and 3 micrograms of nHuTNF-alpha), 4 had complete responses, 10 had partial responses, and 4 had minor responses. The overall response rate was 12.5% (14/112) and the rate was 19.5% in 72 patients with more than 2 x 10(6)U/day. Positive responses were as follows: hepatoma 3/8), renal cell cancer (4/11), breast cancer (4/17), ovarian cancer (1/2), malignant thymoma (1/1) and liposarcoma (1/1). Serious adverse effects like hypotension, oliguria and severe hepatobiliary toxicity were never experienced. The effective and adequate dose of the mixed preparation was considered 2 to 4 x 10(6)U/day/body.

Adult↗
PubMed1992

The immunomodulatory role of IFN-alpha or maltose-stabilized IFN-alpha on T-cell activation.

The effects of human interferon-alpha (IFN-alpha) or maltose-stabilized IFN-alpha (MS-IFN-alpha) on IL-2 production by PHA- or anti-CD3 mAb-stimulated MOLT 16 cells, a human leukemic T cell line, were studied. MS-IFN-alpha is an IFN-alpha-containing powder in which maltose was used as an excipient, and has been shown to have a positive effect on human immunodeficiency virus (HIV)-infected patients. In this study, MS-IFN-alpha powder was dissolved in a culture medium and used for the experiments. IL-2 production by PHA- or anti-CD3 mAb-stimulated MOLT 16 cells was augmented by coculturing with IFN-alpha or MS-IFN-alpha. The augmentation of IL-2 production by IFN-alpha or MS-IFN-alpha was completely abrogated by rabbit anti-IFN-alpha antibody. We have previously shown that IL-2 production by PHA-stimulated MOLT 16 cells is augmented by coculturing with IL-1. Furthermore, IL-2 production by PHA-stimulated MOLT 16 cells was also augmented by human TNF-alpha in a dose-dependent manner. The TNF-alpha-induced augmentation was completely abrogated by rabbit anti-TNF-alpha antibody. Interestingly, both IFN-alpha and MS-IFN-alpha synergized with rIL-1 alpha or TNF-alpha resulting in IL-2 production being augmented far more effectively than either cytokine alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1991

USF-related transcription factor, HIV-TF1, stimulates transcription of human immunodeficiency virus-1.

The transcription factor HIV-TF1, which binds to a region about 60 bp upstream from the enhancer of the human immunodeficiency virus-1 (HIV-1), was purified from human B cells. HIV-TF1 had a molecular weight of 39,000. Binding of HIV-TF1 to the HIV long terminal repeat (LTR) activated transcription from the HIV promoter in vitro. The HIV-TF1-binding site in HIV LTR was similar to the site recognized by upstream stimulatory factor (USF) in the adenovirus major late promoter. DNA-binding properties of HIV-TF1 suggested that HIV-TF1 might be identical or related to USF. Interestingly, treatment of purified HIV-TF1 by phosphatase greatly reduced its DNA-binding activity, suggesting that phosphorylation of HIV-TF1 was essential for DNA binding. The disruption of HIV-TF1-binding site induced a 60% decrease in the level of transcription from the HIV promoter in vivo. These results suggest that HIV-TF1 is involved in transcriptional regulation of HIV-1.

B-Lymphocytes↗
PubMed1991

A cell line of human malignant astrocytoma producing autocrine growth factor.

A cell line was established from an anaplastic astrocytoma from a 69-yr-old female. The cells have been serially subcultured over 300 times for 6 yr without showing any sign of cell senescence. Their doubling time is about 36 h. The cells are fusiform and often hexagonal in sparse culture, but become spindle-shaped and formed mosaic structure in confluent culture. Under electron microscopy, intermediate filaments were randomly distributed in the cytoplasma, especially in the perinuclear space. The chromosome number was near tetraploid and varied from 86 to 94 chromosomes with a modal number of 91. The alpha and beta subunits of S-100 protein, vimentin, and glial fibrillary acidic protein (GFAP), which are reliable markers of astrocytic cells, were demonstrated in a large number of cells by immunoperoxidase staining. The results of immunoblotting showed that the expression of vimentin was much higher than that of GFAP. The tumorigenicity of the cells was revealed by xenografting into nude mice, which were X-irradiated before inoculation. Culture medium conditioned by the cells promoted growth of these cells in serum-free conditions and of normal rat glial cells in serum-depleted culture. The growth-promoting effect of conditioned medium was lost by trypsinization and reduced by boiling. These findings suggest that these cells are derived from neoplastic astrocytic cells and secrete a self-acting polypeptide growth-promoting factor into the culture medium.

Aged↗
PubMed1991

[A disproportionately large communicating fourth ventricle occurring after suboccipital craniectomy: report of two cases].

Two cases of a disproportionately large communicating fourth ventricle (DLCFV) which developed after suboccipital craniectomy are reported. The first case was that of a 43-year-old female who sustained subarachnoid hemorrhage, and the second case was that of a 12-year-old male with medulloblastoma. Patency of the aqeductal canal and occlusion of the fourth ventricle outlets were demonstrated in both cases by metrizamide ventriculography, with intraventricular injection of contrast material. Clinical history was analyzed with repeated CT scan, and pathogenesis of DLCFV was discussed with review of the literature.

Adult↗
PubMed1990

Growth of rat-mouse hybridoma cells in immunosuppressed hamsters. An easy and effective method to prepare monoclonal antibodies from heterohybridoma cell lines.

Rat-mouse hybridoma cells producing anti-mouse IgE antibodies were intraperitoneally or subcutaneously inoculated into newborn or suckling hamsters receiving rabbit anti-hamster thymocyte globulin from the day of birth twice a week for at least 3 weeks. The hybridoma cells were found to grow in the abdominal cavity of the hamsters as ascites tumor or in subcutaneous tissue as solid tumor without loss of antibody-secreting activities. For the production of ascites, 2-week-old hamsters were preferable to newborn hamsters. In 3-week-old hamsters, the hybridoma cells could scarcely survive. The antibody titers of the ascites were determined to be 10(5)-10(6) in the ELISA and in the ability to neutralize the skin-sensitizing capacity of mouse IgE antibodies. The rat monoclonal antibodies were easily separated from ascites, serum or cell culture supernatant with affinity chromatography using Affigel protein A-Sepharose and anti-hamster IgG-Sepharose columns. The described method could be efficiently applicable for the proliferation of other hybridomas, such as human-human, human-mouse or hamster-mouse, etc.

Animals↗
PubMed1990

Biological and immunological properties of Sugi basic protein-pullulan conjugate. II. Is the reduced ability to elicit the Arthus reaction based on the poor activation of complement by immune complex consisting of anti-Sugi basic protein and Sugi basic protein-pullulan?

Ability of Sugi basic protein (SBP)-pullulan conjugate to elicit the Arthus reaction was found to be markedly reduced, about 100 times lower than that of native SBP. To analyze this reduced ability, activation of complement by immune complex consisting of SBP-pullulan and anti-SBP antibodies was studied. Tests for complement consumption, C3 conversion and cleavage of factor B revealed that immune complex formed with SBP-pullulan is incapable of supporting efficient activation of the complement system. Previously, we have shown data suggesting that SBP-pullulan conjugate would be a good candidate for desensitization therapy against cedar pollinosis. The results presented in this paper provide additional support for the suggestion.

Allergens↗