Search PubMed⌕ Search

Biomedical subjects

H Okudaira

Publications and source records attributed to H Okudaira.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Inhibitory effect of ONO-1078, a novel leukotriene receptor antagonist, on human peripheral blood eosinophils].

To determine whether ONO-1078, leukotriene receptor antagonist, inhibits the activation of eosinophils, we investigated the effect of ONO-1078 on the release of leukotriene (LTC4) and eosinophil cationic protein (ECP) from human peripheral blood eosinophils of allergic patients and normal subjects. After preincubation with ONO-1078, eosinophils were incubated with calcium ionophore (A23187). ONO-1078 10(-5) and 10(-6) M inhibited LTC4 release of allergic patients eosinophils and 10(-5)-10(-9) M inhibited LTC4 release of normal subjects eosinophils. ONO-1078, 10(-5) M, also inhibited ECP release of eosinophils obtained from both asthma patients and normal subjects. We think that ONO-1078 may have another pharmacological effect to prevent the activation of human peripheral blood eosinophils by inhibiting LTC4 and ECP release. These results suggest that ONO-1078 might be useful in controlling bronchial asthma.

Asthma↗
PubMed1995

Analysis of the IgE-epitope of Der f 2, a major mite allergen, by in vitro mutagenesis.

Der f 2 is a major mite allergen composed of 129 amino acid residues. To determine the major epitopes on Der f 2 recognized by human IgE antibodies, artificial mutations were introduced to Der f 2 protein. The IgE-binding activity of Der f 2 was significantly decreased by deletion of 10 amino acids at the N-terminus or nine amino acids at the C-terminus. Site-directed mutagenesis with a single amino acid replacement by Ala or Leu in both N- and C-terminal regions as well as a central portion was performed to generate 42 single-site mutations. Amino acid replacement around a disulfide bond of Cys8-Cys119 caused a marked decrease in IgE-binding activity. Furthermore, a distinct decrease in IgE-binding was also caused by Ala-substitution close to a disulfide bond of Cys73-Cys78 and by mutations of a few charged residues. From these results, it was concluded that the two disulfide-forming regions of Der f 2 and several charged residues are important for forming major epitope structures recognized by human IgE antibodies.

Allergens↗
PubMed1995

Neurotropin inhibits accumulation of eosinophils induced by allergen through the suppression of sensitized T-cells.

A non-protein extract isolated from the inflamed dermis of rabbits inoculated with vaccinia virus (Neurotropin) has been clinically used in Japan as an analgesic and anti-allergic drug. To clarify its anti-allergic mechanism, the effect of Neurotropin on eosinophil accumulation induced by ragweed pollen extract or platelet-activating factor (PAF) was examined in BALB/c mice. Neurotropin inhibited the T-cell-dependent accumulation of eosinophils induced by allergen in a dose-dependent manner when administered during sensitization. However, Neurotropin was unable to inhibit the T-cell-independent accumulation of eosinophils induced by PAF. A T-cell transfer experiment was performed to address the inhibitory mechanism. A marked accumulation of eosinophils was observed when recipients were injected i.p. with allergen and Nylon wool column-passed splenic T-cells from the sensitized donor mice. However, significant accumulation of eosinophils was not observed when sensitized donor mice were administered with Neurotropin but not saline. Taken together, these results suggest that Neurotropin inhibits the accumulation of eosinophils induced by allergen via the suppression of sensitized T-cell induction, or alternatively by interfering with T-cell function.

Adjuvants, Immunologic↗
PubMed1995

IL-5 production by CD4+ T cells of asthmatic patients is suppressed by glucocorticoids and the immunosuppressants FK506 and cyclosporin A.

IL-5 was produced in vitro by peripheral blood mononuclear cells (PBMC) of mite-sensitive atopic patients upon challenge with specific allergen, while PBMC of healthy controls produced essentially no IL-5. Stimuli delivered by the combination of phorbol ester and Ca2+ ionophore induced marked IL-5 production by PBMC obtained from atopic and non-atopic asthmatics, suggesting that both protein kinase C and Ca2+ influx are required for IL-5 production. CD2- or CD4-bearing cell depletion almost completely removed IL-5-producing cells while CD8-bearing cell depletion rather enriched them. These findings indicate that CD4+ T cells are the principal source of IL-5 in PBMC. The capacity of PBMC of atopic asthmatics, non-atopic asthmatics and healthy controls to produce IL-2, IL-4, IL-5 and IFN-gamma was compared, to find that cytokine-producing capacities other than that of IL-5 (IL-2, IL-4 and IFN-gamma) were not significantly different among the three groups. Dexamethasone, FK506 and cyclosporin A suppressed IL-5 production in vitro in a dose-dependent manner. Clear dose-dependent suppression of IL-5 gene expression by FK506 was also observed. Treatment of asthmatic patients with inhaled glucocorticoid (beclomethasone dipropionate) ameliorated clinical symptoms, improved lung function and markedly suppressed IL-5 production by PBMC, suggesting the essential role of IL-5 in the pathogenesis of bronchial asthma and the clinical importance of its regulation.

Adult↗
PubMed1995

Effect of fibronectin on the production of leukotriene C4 by eosinophils.

The effect of fibronectin on leukotriene C4 (LTC4) production by eosinophils was examined. Eosinophils obtained from patients with bronchial asthma were cultured for 3 h with or without fibronectin and culture supernatants were assayed for LTC4 by specific enzyme immunoassay. LTC4 was produced in a time- and dose-dependent manner in the presence of fibronectin, and maximum production of LTC4 was observed 3 h after addition of 100 micrograms/ml of fibronectin. These results suggest that eosinophils may be activated by interaction with extracellular matrix proteins, including fibronectin, and play a role in the pathogenesis of bronchial asthma.

Asthma↗
PubMed1995

Age-related differential mRNA expression of T cell cytokines in NZB/NZW F1 mice.

The mRNA expression of interleukin (IL)-2, IL-2 receptor-alpha-chain (IL-2R alpha), IL-4 and interferon-gamma (IFN-gamma) in spleen cells from NZB/NZW F1) mice following the stimulation with concanavalin A (Con A) was examined by Northern blot analysis. Kinetic patterns of the mRNA expression after the stimulation were not different between 2-month-old and 6 to 8-month-old B/W F1 mice. However, relative mRNA expression of IL-2 to a cytoskeletal protein, alpha-Tubulin was lower in 6 to 8-month-old B/W F1 mice than in 2-month-old mice. Similar but not significant tendency was observed in IL-2R mRNA expression. In contrast, Relative IL-4 mRNA expression in 6 to 8-month-old B/W F1 mice was significantly higher than that in 2-month-old animals. On the other hand, no apparent change was observed in IFN-gamma mRNA expression. Flow cytometric analysis indicated that there was no apparent difference in proportion of L3T4 positive T cells in spleen cells from 2 and 6 to 8-month-old B/W F1 mice. These results suggest that mRNA expression of IL-2 and IL-4 differentially changes with aging in autoimmune B/W F1 mice.

Age Factors↗
PubMed1995

[Inhibitory effect of histamine-added mouse gamma-globulin on eosinophil accumulation induced by allergen in BALB/c mice].

Histamine-added human gamma-globulin (HG) has been clinically used as an anti-allergic drug for asthma, allergic rhinitis and atopic dermatitis. Retrospective analysis of clinical data have indicated that s.c. administration with HG not only improves clinical symptoms but also suppresses the number of eosinophils of nasal secretion or peripheral blood in allergic patients. Thus, the possibility was explored that HG may actively suppress eosinophil accumulation in allergic inflammation. The eosinophil accumulation in peritoneal cavity was induced by i.p. injection with ragweed pollen extract in BALB/c mice which had been repeatedly sensitized with the allergen for three weeks. Histamine-added mouse gamma-globulin (Mouse HG) at 150 mg/kg/day markedly inhibited the allergen-induced eosinophil accumulation when administered s.c. two times a week for three weeks. The inhibitory effect was almost the same as that of cyclosporin A at 100 mg/kg/day. Interestingly, equivalent dose of histamine or mouse gamma-globulin alone had no inhibitory effect in the same system. These results suggest that HG suppresses chronic allergic inflammation through the inhibition of eosinophil accumulation.

Allergens↗
PubMed1994

Accumulation of multiple T cell clonotypes in lungs of healthy individuals and patients with pulmonary sarcoidosis.

T cell accumulation and activation in lung may play a major role in the pathogenesis of immunologic lung diseases such as sarcoidosis. Using the combination of RT-PCR and subsequent single-strand conformation polymorphism analysis, we examined T cell clonality in lung and peripheral blood of healthy individuals (n = 5) and patients with active pulmonary sarcoidosis (n = 7). RNA was extracted from PBLs and bronchoalveolar lavage fluid cells, and converted to cDNA. PCR was performed using a set of V beta-C beta primers (V beta 1-20). Products were denatured and electrophoresed in nondenaturing 5% polyacrylamide gel. The existence of a distinct T cell clonotype was detected as a band on a smear. In both groups T cells in PBLs showed a number of clones that expanded. A significantly greater number of clones was detected in BAL compared with PBL in both groups (normal: 25.3 +/- 7.2 in PBL vs 62.8 +/- 5.2 in lung; sarcoid: 25.0 +/- 6.2 in PBL vs 90.0 +/- 6.6 in lung, mean value +/- SEM). In sarcoid lung greater numbers of clones were detected than in lungs of healthy controls (p < 0.012). These clonal expansions were observed over all the 20 V beta families examined, and were not restricted to certain V beta families. These results suggest that there are clonal expansions even in normal lung, and that in sarcoidosis, apparently, additional T cell clones using multiple V beta segments might be activated and accumulated at the site of the disease.

Adult↗
PubMed1994

Regulation of interleukin-5 production by peripheral blood mononuclear cells from atopic patients with FK506, cyclosporin A and glucocorticoid.

Upon stimulation with phorbol ester and ionomycin, peripheral blood mononuclear cells (PBMC) of atopic patients with moderate eosinophilia produced significantly higher amounts of IL-5 compared to that of normal subjects. This finding renders further support to the notion that T cell-eosinophilic inflammation plays a central role in allergic disorders. IL-5 induction in vitro was completely inhibited by immunosuppressant FK506, cyclosporin A and dexamethasone. FK506 applied in vivo effectively suppressed clinical symptoms of atopic dermatitis and IL-5 production of PBMC. FK506 and cyclosporin A may become a better therapeutic modality against allergic diseases.

Administration, Topical↗
PubMed1994

Effects of amino acid variations in recombinant Der fII on its human IgE and mouse IgG recognition.

Amino acid sequencing of the major mite allergen Der fII purified from mite body extract revealed that it is a mixture of at least two variants. Substitutions were found only at positions in which amino acid variations were predicted from the nucleotide sequences of three cloned cDNAs. When cDNAs corresponding to the three variants were expressed in Escherichia coli, Der fII proteins were produced as inclusion bodies. Denaturation and renaturation with urea converted recombinant Der fII into a protein with three intramolecular disulfide bonds (Cys8-Cys119, Cys21-Cys27, and Cys73-Cys78), which were identical to those previously identified in native Der fII. All the variants, including native Der fII, were equally recognized by human IgE antibodies from 14 different sera of mite-allergic patients. These results suggested that recombinant Der fII proteins assumed a conformation identical to that of the native Der fII and that all the Der fII variants acted as allergens. This result also suggested that IgE antibody binds to the region where there were no amino acid variations. The binding ability of the monoclonal antibody (mAb) 18G8 for the variant clones 1, 2, and 11 Der fII was almost the same. However, mAb 15E11 bound to clone 1 Der fII more efficiently than to clones 2 and 11, whereas mAb 13A4 recognized clone 2 Der fII as the most preferable antigen. This suggested that these antibodies recognized the region of amino acid variations. The stability of Der fII variants was analyzed by measuring their IgE antibody binding activity after heating, freezing, or acid treatment, and was analyzed by resistance to trypsin digestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1993

Determination of three disulfide bonds in a major house dust mite allergen, Der f II.

Der f II is a major mite allergen consisting of 129 amino acid residues. Der f II contains six cysteine residues, suggesting the existence of three disulfide bonds which would stabilize this small protein. As the first step in revealing the relationship between the structure and the allergenic property of Der f II, the formation of disulfide bonds was examined. Der f II purified from Dermatophagoides farinae was treated with lysyl-endopeptidase or proline-specific endopeptidase, and the peptide fragments thus generated were separated by reverse phase high performance liquid chromatography. Determination of the amino acid sequence of each peptide collected in this way proved the existence of three disulfide bonds between Cys8 and Cys119, Cys21 and Cys27, and Cys73 and Cys78.

Allergens↗
PubMed1992

Prolonged survival of MRL-lpr/lpr mice treated with Tripterygium Wilfordii Hook-F.

MRL-lpr/lpr mice were treated with Tripterygium Wilfordii Hook-F (TWHF), a Chinese herbal medicine successfully used for human rheumatoid arthritis. Dramatic prolongation of survival and the reduction of urinary protein were observed in mice treated with a high dose of TWHF (20 mg/kg, three times a week) compared to the control animals receiving solvent alone. A slight but significant reduction was also seen in the degree of lymphadenopathy and arthritis with the high dose treatment. Surprisingly, no significant difference was present in IgM rheumatoid factor and IgG anti-double-stranded DNA antibody levels or in the histopathology of lupus nephritis. These results indicate the dissociation of histopathological renal disease and the degree of proteinuria or the life span. Although further pharmacological analysis is required, TWHF might be potentially useful for diseases such as systemic lupus erythematosus or nephrotic syndrome.

Animals↗
PubMed1992

Hypersensitivity pneumonitis in athymic nude mice. Additional evidence of T cell dependency.

We previously demonstrated that C57 Black/6 mice develop lung lesions similar to human hypersensitivity pneumonitis (HP) by repeated transnasal administration of Thermoactinomyces vulgaris (Tv) antigen. To elucidate the role of T cells in the development of this disease, Tv antigen (90 micrograms/day) was transnasally administered to athymic nude C57 Black/nu/nu (nu) mice and their littermates (+/nu) three times a week for 3 wk. The nude mice developed minimal lung lesions, whereas their thymus-intact littermates (+/nu) showed changes equivalent to those in C57 Black/6. Changes in local inflammatory cell responses were evaluated by bronchoalveolar lavage, and increases in the numbers of lymphocytes and macrophages were significantly less severe in the nude mice than in the +/nu mice. Interestingly, the increase in polymorphonuclear leukocytes 6 h after the last antigen inoculation was equivalently seen in both groups. When spleen-derived T cells (more than 95% Thy-1.2+) from the sensitized +/nu mice were adoptively transferred to nude mice, the HP-like lesions in the recipients were found after Tv antigen challenge. These results suggest that Thy-1.2+ T cell-mediated immunity was necessary for the development of HP in this murine model.

Alveolitis, Extrinsic Allergic↗
PubMed1992

Specific measurement of a major mite allergen, Der f II, by an enzyme-linked immunosorbent assay system using monoclonal anti-Der f II antibodies.

An enzyme linked immunosorbent assay system using a monoclonal antibody, 15E11, specific for a major allergen Der f II in house dust mite, was developed. This system detected only Der f II in the presence of Der p II and other allergens. The Der f II contents in several house dust samples significantly correlated with the numbers of the mites in the same house dust samples (n = 14, r = 0.88, p < 0.001). These data showed that this system was useful for specific measurement of Der f II in house dusts.

Allergens↗
PubMed1992

[An autopsy case of sarcoidosis associated with renal failure].

A 62-year-old woman presented with uveitis and abnormal chest X-ray (bilateral hilar adenopathy). Skin biopsy in 1983 had revealed non-caseating epithelioid cell granuloma consistent with sarcoidosis. Her serum biochemical investigations and exploratory laparoscopy suggested nodular liver cirrhosis, but biopsy was not performed. Both blood urea nitrogen (BUN) and serum creatinine values were within normal limits. She received prednisolone therapy of 15 mg daily initially, and later a maintenance dose of 5 mg daily. In 1985, she complained of skin itching and her laboratory data revealed severe renal insufficiency (BUN 97 mg/dl, serum creatinine 12.2 mg/dl) and hypercalcemia (corrected serum calcium level: 11.5 mg/dl). Prednisolone treatment (40 mg daily) resulted in a dramatic improvement of renal function as well as other clinical abnormalities due to sarcoidosis, without any significant changes in liver function. She died of cerebral infarction in 1989. Autopsy showed interstitial nephritis with tubular calcinosis and hyalinized glomeruli. It is postulated that hypercalcemia due to sarcoidosis contributed to the renal failure in this patient. This case suggests that renal damage due to sarcoidosis may be reversible with appropriate corticosteroid therapy.

Female↗