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T Numao

Publications and source records attributed to T Numao.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Detection of IL-5 mRNA in bronchial biopsies from asthmatics by non-radioactive in situ hybridization].

To determine whether IL-5 is locally produced in the bronchial mucosa of asthmatics, and to ascertain the precise cell type producing this cytokine, we examined bronchial biopsies by non-radioactive in situ hybridization and immunohistochemistry. IL-5 cDNA probes were labeled with digoxigenin-dUTP and hybridized to frozen or paraffin tissue sections. Hybridization signals were visualized by an immunohistochemistry technique. An IL-5-producing T cell clone derived from a patient with adult T cell leukemia was used as a positive control. Specific hybridization signals for IL-5 mRNA were observed in the bronchial mucosa of symptomatic asthmatics. No hybridization signal was detected in the control subject in whom no underlying disease was found. Immunohistochemical staining of serial sections using a panel of monoclonal antibodies directed against lymphocyte subsets strongly suggested that cells expressing mRAN for IL-5 were T cells. These results suggest that a cell-cell interaction between T cells and eosinophils through IL-5 may play an important role in the airway inflammation in asthma.

Asthma↗
PubMed1993

Tumor necrosis factor alpha induces migration of human eosinophils.

In order to evaluate the role of tumor necrosis factor alpha (TNF alpha) in the recruitment of eosinophils and neutrophils into the tissues, we studied the effect of TNF alpha on the migration of those cells in vitro, employing a modified Boyden's chamber technique. TNF alpha induced a significant migration of human eosinophils in a dose-dependent manner, and the preincubation of eosinophils with TNF alpha enhanced platelet activating factor (PAF)-induced eosinophil migration. Checkerboard analysis revealed that the eosinophil migration induced by TNF alpha was mainly due to chemokinesis. On the other hand, TNF alpha induced neither neutrophil migration nor enhancement of PAF-induced neutrophil migration. These results indicate that TNF alpha possesses a chemokinetic effect on human eosinophils and that TNF alpha augments the migration of eosinophils by PAF.

Chemotaxis, Leukocyte↗
PubMed1993

[Advance in eosinophil chemotaxis assay method--automatic count of migrated cells by the image analyzing system in the Boyden method].

Eosinophils, which are prominent inflammatory cells in the asthmatic airway, are attracted to the airway by several chemoattractants. At present, eosinophil chemotaxis is studied employing the Boyden Millipore chamber system in vitro. In the Boyden method, the number of migrated cells are evaluated by direct microscopic observation of individual cells. This microscopic procedure usually requires much time and it is difficult to obtain objective results. Therefore, we have developed a new fractional measurement technique, using the image analyzing system connected with a color video camera and a computer for counting the eosinophils which have migrated into a filter. Using this system with the Boyden method, migrated cells were observed more objectively and quickly. Therefore, this image analyzing system with the Boyden method, may be a useful technique for the fractional measurement of migrated eosinophils in a sample mixture of eosinophils and neutrophils.

Cell Movement↗
PubMed1992

Neuropeptides modulate human eosinophil chemotaxis.

To investigate the role of neuropeptides in allergic inflammation, we examined the effect of peptides on eosinophil chemotaxis. Eosinophils were purified from the blood of allergic and normal subjects using a discontinuous Percoll density gradients. Chemotaxis was induced by platelet-activating factor (PAF) and leukotriene B4, and was assayed by a modified Boyden's chamber technique. Four neuropeptides were examined in this study: substance P (SP), neurokinin A, calcitonin gene-related peptide (CGRP), and cholecystokinin octapeptide. Peptides alone (10 nM to 10 microM) were not chemotactic for eosinophils. However, when eosinophils were pre-treated with peptides (100 nM) at 37 degrees C for 30 min, chemotactic response to PAF (10 nM) was significantly enhanced (p < 0.01) in allergic subjects; % control by SP, neurokinin A, CGRP and cholecystokinin octapeptide was 269 +/- 42, 243 +/- 32, 227 +/- 21, and 251 +/- 42, respectively (n = 8). Similar results were obtained in leukotriene B4-induced eosinophil chemotaxis. In contrast, no enhancement was observed in normal subjects. Potentiating effect of SP and CGRP on PAF-induced eosinophil chemotaxis in allergic subjects was significantly attenuated by SP antagonist [D-Pro2,D-Trp7,9]-SP and human CGRP (8-37) receptor antagonist, respectively. Neutral endopeptidase inhibitors (phosphoramidon, leupeptin, and bestatin) failed to significantly augment the PAF-induced eosinophil chemotaxis when the cells were pretreated with various peptides and neutral endopeptidase inhibitors. The C-terminal fragment of SP (SP6-11) had an effect similar to that of the intact SP molecule, whereas no potentiating effect by the N-terminal of SP (SP1-9) was observed. These results suggest that neuropeptides may play a significant role in eosinophil infiltration by priming cells in allergic inflammation.

Chemotaxis, Leukocyte↗
PubMed1992

[The role of bronchial responsiveness to leukotrienes in antigen-induced immediate and late asthmatic response].

In order to clarify the role of leukotriene in the antigen-induced asthmatic response, we carried out mite-antigen, leukotriene D4 (LTD4) and histamine inhalation tests in 21 mite-sensitive atopic asthma patients, and investigated the relationship between the bronchial responsiveness to mite (PD20-Mite) and that to LTD4 and histamine (PD20-LTD4, PD20-Hist). We then compared PD20-LTD4 and PD20-Hist between the groups with and without late asthmatic response (LAR), and investigated the relationship between the peak percentage fall of FEV1.0 in LAR (magnitude of LAR) and PD20-LTD4 and PD20-Hist. There were significant correlations between PD20-LTD4 and PD20-Mite (r = 0.590, p < 0.01), and between PD20-Hist and PD20-Mite (r = 0.669, p < 0.001). The bronchial responsiveness to LTD4 and histamine was significantly higher in the group with LAR. In addition, PD20-LTD4 showed a significant negative correlation with the magnitude of LAR (r = 0.724, p < 0.001). Furthermore we analyzed the relationship between PD20-LTD and the ratio of the magnitude of LAR to that of IAR (immediate asthmatic response), because there was a significant correlation between the magnitude of IAR and that of LAR (r = 0.842, p < 0.001) in 16 asthmatic patients with dual asthmatic response, and found that the correlation coefficient was also very high (r = -0.836, p < 0.001). These results suggest an important role of leukotriene in the antigen-induced asthmatic response.

Adolescent↗
PubMed1991

[Effects of anti-asthmatic drugs on human eosinophil chemotaxis].

To evaluate the acute effects of anti-asthmatic drugs in vitro, we examined the modulation of various anti-asthmatic drugs in therapeutic concentrations on PAF-induced human eosinophil chemotaxis. Aminophylline (20 micrograms/ml) and Isoproterenol (10 nM) inhibited PAF (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas no inhibitory effects were observed by Dexamethasone (0.1 microM), Tranilast, Ketotifen or Azelastine. Aminophylline (20 micrograms/ml) also inhibited LTB4 (3 X 10(-8) M)-induced eosinophil chemotaxis nearly 30%, whereas it did not inhibit chemotaxis induced by zymosan (5 mg/ml)-activated serum. These results indicate that anti-asthmatic drugs except for aminophylline and isoproterenol, when used acutely in therapeutic concentrations, have no striking inhibitory effects on PAF-induced eosinophil chemotaxis. These results further suggest the possibility that there are different mechanisms in eosinophil chemotaxis induced by PAF, LTB4 or by C5a.

Aminophylline↗
PubMed1991

[Eosinophil cationic protein in patients with bronchial asthma].

To evaluate the role of eosinophils in the pathogenesis of bronchial asthma, we measured eosinophil cationic protein (ECP), one of the eosinophil granule proteins. Serum ECP levels were measured by radioimmunoassay in asthmatic (n = 59) and non-asthmatic (n = 47) patients. Preliminary study showed that ECP levels were time-dependently increased in the blood samples until 3 hr. Based on the findings, we determined to measure serum ECP levels at 30 min after blood sampling. Serum ECP levels and blood eosinophil counts in asthmatic patients were significantly higher than those in non-asthmatic patients (p less than 0.01). There was also a positive correlation between serum ECP levels and blood eosinophil counts in patients with asthma (r = 0.46, p less than 0.001). No significant difference was observed in either serum ECP levels or blood eosinophil counts in asthmatic patients classified by clinical type and severity. Blood eosinophil counts in patients with asthma attacks were significantly greater than in those in remission (p less than 0.05), but no significant difference was observed in serum ECP levels between these groups, suggesting an enhanced elimination of ECP during attack. Serum alpha-2 macroglobulins, which bind to ECP and may function as scavengers for ECP, were not significantly different in these group. These results suggest that serum ECP levels may not be a direct indicator of eosinophil activation or degranulation in the pathogenesis of asthma.

Adult↗
PubMed1990

[Inhibitory effect of FK-506 on the development of late asthmatic response and on the increased bronchial responsiveness].

We examined the effects of FK-506, a potent immunosuppressive agent, on the development of late asthmatic response (LAR) and on the increased bronchial responsiveness to acetylcholine following LAR in guinea pig model of asthma. Guinea pigs sensitized by repeated inhalation of ovalbumin (OA) were intravenously given metopiron 24 hours before and 30 minutes before antigen challenge and to prevent death from immediate severe bronchoconstriction, chlorpheniramine maleate was also injected. When we defined LAR as the responses with a two-fold increase in respiratory resistance during the late phase of antigen challenge, twelve out of fifteen control animals demonstrated apparent LAR. However, when guinea pigs were treated with FK-506 from the beginning of immunization period, the development of LAR was completely inhibited, although similar magnitude of immediate bronchoconstriction was observed, and a subsequent increase in bronchial responsiveness was significantly blocked. We also measured bronchial responsiveness to acetylcholine before, 24 and 72 hours after antigen challenge. FK-506-treated animals inhibited an increase in bronchial responsiveness to acetylcholine. These results suggest that the involvement of cell-mediated immunity may be important in the development of LAR and an increase in bronchial responsiveness.

Animals↗
PubMed1990

[Antigen-induced biphasic eosinophil infiltration in the airways of actively sensitized guinea pigs and its inhibition by PAF antagonist and cyclosporin A].

Bronchial eosinophilia is a characteristic of asthma. To elucidate the mechanisms of eosinophil accumulation in the airways, the time course of eosinophil infiltration in the airway mucosa after antigen inhalation was examined in actively sensitized and passively sensitized guinea pig models of asthma. The lungs and tracheae were removed at intervals after antigen challenge, fixed and stained. The eosinophil infiltration was quantitated in the tracheal walls by counting the number of cells per square millimeter. Guinea pigs sensitized by intraperitoneal injection of ovalbumin (OA) responded to a single exposure to aerosolized OA with biphasic infiltration of eosinophils in the tracheal walls; a striking early-phase which peaked at 6 hr and a delayed-phase which peaked at 24 hr and persisted for as long as 5 days. These kinetics were different from those observed with passively sensitized animals which showed only early-phase infiltration. Administration of CV-6209, a specific PAF antagonist, before and 12 hrs after antigen challenge significantly (p less than 0.01) inhibited the early-phase but not the delayed-phase eosinophil infiltration in actively sensitized animals. In contrast, when guinea pigs were treated with Cyclosporin A, a T lymphocyte-selective immunosuppressive agent, throughout the immunization period, the delayed-phase but not the early-phase infiltration was significantly (p less than 0.01) inhibited. These results suggest that PAF may contribute to early-phase and T cell factor(s) may contribute to delayed-phase eosinophil infiltration of the airways.

Animals↗