Biomedical subjects

Y Nasuhara

Publications and source records attributed to Y Nasuhara.

28 records · Page 2Linked to original sources

PubMed1996

Interleukin-1 beta decreases sensitivity of guinea-pig airway to potassium chloride and isoproterenol by an epithelium-dependent mechanism.

Airway inflammation may cause alteration of airway responses in chronic airway diseases, such as bronchial asthma. The objective of this study was to examine whether interleukin-1beta (IL-1beta) [corrected], one of the pro-inflammatory cytokines, has a direct effect on airway functions. The effects of IL-1beta on carbachol, KCl and isoproterenol (ISO) responses of isolated guinea-pig tracheal strips were examined by measuring isometric tension in tissue bath. Responses of tracheal strips with or without epithelium to each agonist were compared before and after incubation with IL-1beta (25 ng or 250 ng/mL). Both 1 h and 5 h incubation of the strips with 250 ng/mL IL-1beta significantly decreased the sensitivity not only to KCl (P < 0.05; P < 0.01, respectively), but also to ISO (both P < 0.05) without affecting maximum contraction or relaxation. Response to carbachol was not affected by IL-1beta. Epithelial denudation abolished the effects of IL-1beta on KCl and ISO responses. Indomethacin (2 micromol/L) [corrected] reversed the effects of IL-1beta both on KCl and on ISO. These results suggest that IL-1 beta decreases the sensitivity of airway strips to KCl and ISO, possibly by stimulating prostaglandin production from the airway epithelium [corrected].

Animals↗

PubMed1996

[Meanings of the clinical parameters of airway hyperresponsiveness].

Clinically, threshold concentrations of agonist causing 20% decrease in FEV1 (PC20 FEV1) or 35% decrease in airway conductance (PC35Gaw) are usually used as parameters of airway hyperresponsiveness. In this session, what do these parameters mean was discussed based on theoretical analysis, experimental data and clinical observations. Theoretically, using these parameters, it seems very difficult to distinguish whether hyperresponsiveness is due to the change in sensitivity or maximum responses. Experimental and clinical observations suggest that these parameters are affected by multiple factors, for example, genetic vs. acquired factors and functional vs. structural factors. There may be differences in the degree of contributions of each factors on clinical parameters of airway responsiveness between asthmatics and control, and mild and chronic severe asthma. Clinically, considering such differences may be important in interpreting the changes of these parameters.

Asthma↗

PubMed1995

Dairy farmers have increased methacholine bronchial responsiveness independent of sensitization to mold antigens.

Patients with farmer's lung disease (FLD) and dairy farmers have nonspecific bronchial hyperresponsiveness. To examine the factors determining bronchial hyperresponsiveness among dairy farmers, we studied airway functions, airway responses to inhaled methacholine, serum total IgE levels, and antigen-specific IgE levels in 37 dairy farmers and 11 local control subjects. The 37 dairy farmers consisted of three groups; 12 farmers with episodes of FLD (FLD group), 13 farmers with serum antibody to Micropolyspora faeni (MF) and/or Thermoactinomyces vulgaris (TV) but without episodes of FLD (Ab(+) group), and 12 farmers without serum antibodies to MF and TV and without episodes of FLD (Ab(-) group). Pulmonary function tests showed small airways disorders among farmers (each of the three groups versus control subjects; p < 0.05). Methacholine provocation test, utilizing PD35Grs (a cumulative dose of methacholine that induces 35% reduction in respiratory conductance [Grs]), showed bronchial hyperresponsiveness in each group of dairy farmers compared with that in control subjects (Log PD35Grs, mean +/- SEM: 1.22 +/- 0.18, 1.00 +/- 0.17, and 1.20 +/- 0.20, respectively, versus 2.10 +/- 0.09; p < 0.001). However, there was no statistically significant difference in bronchial responsiveness among the three groups of dairy farmers. In addition, there was no significant difference in serum total IgE levels and specific IgE antibodies among the four groups. These results suggest that the bronchial hyperresponsiveness to methacholine among dairy farmers is not due to past episodes of FLD or sensitization to MF and/or TV, but is possibly due to the occupational environment of dairy farming.

Antibodies, Bacterial↗

PubMed1995

[Acyclovir and guinea-pig airway smooth muscle].

Acyclovir, an anti-herpes virus drug, has been reported to affect aspirin-induced asthma (AIA). Acyclovir was reported to decrease the sensitivity to aspirin in some AIA patients. Although the hypothesis that AIA is related to viral infection has been stated, there is no proof that patients with AIA are infected with a specific virus. Therefore, whether the effect of acyclovir on AIA is due to an antiviral effect is not clear. We hypothesized that acyclovir directly affects airway smooth muscle. To test this hypothesis, we examined whether acyclovir can directly contract or relax guinea-pig airway strips, and whether it can modify contraction or relaxation induced with several agents in vitro. Acyclovir did not directly affect basal smooth muscle tone and did not affect the responses to leukotriene D4, prostaglandin E2, carbachol, or KCl. We conclude that acyclovir has no direct effect on the function of guinea-pig airway smooth muscle.

Acyclovir↗

PubMed1995

[Factors influencing patterns of airway response after allergen challenge in patients with bronchial asthma].

We examined patterns of airway response of thirty nine asthma patients who had positive responses on allergen inhalation tests. Six types of inhaled allergens were used: house dust mite, animal, pollen, plant, mold, and others. Three patterns of responses were found: isolated immediate asthmatic response (IAR), immediate and late response (Dual), and isolated late asthmatic response (LAR). No relationship was found between the pattern of response and pulmonary function, airway sensitivity, IgE RIST titers, numbers of eosinophils, or concentration of inhaled antigens. Animal antigens tended to cause a dual response, and molds did only rarely. Ten of 39 challenged patients had an isolated LAR, half of which were caused by mold antigen inhalation. RAST scores were lower in isolated LAR than in other responses. Changes in the number and proportion of peripheral leukocytes during the challenge tests were also studied. Total leukocyte count had increased significantly in the isolated LAR group by 24 hours after the inhalation. These results suggest that the pattern of airway response after inhalation depended in part on the type of inhaled antigen, and that non-IgE mediated immune reactions have some role in the isolated LAR.

Adult↗

PubMed1995

[A case of mycosis fungoides with pulmonary involvement: effect of etoposide and prednisolone].

Persistent coughing and bloody sputum developed in a 75-year-old man with mycosis fungoides. Chest X-ray films on admission showed combined patterns of alveolar and interstitial shadows in both lung fields. Histological examination of the transbronchial lung biopsy specimen revealed patchy infiltration of mycosis fungoides cells in alveolar septa. VEPA chemotherapy was ineffective against skin lesions and caused bacterial pneumonia, but combined treatment with etoposide (200 mg, once a week) and prednisolone (30 mg, 3 days per week) resulted in remission. The patient has been taking oral etoposide and prednisolone regularly, and has been free of skin and pulmonary lesions for two years. Combined therapy with low-dose etoposide and prednisolone may be worth trying in cases of advanced mycosis fungoides with pulmonary involvement.

Aged↗

PubMed1994

A case of pulmonary AV fistula. Possible involvement of adenosine in hyperventilation.

A 21-yr-old man with multiple pulmonary AV fistulae presented with moderate hypoxemia with chronic hyperventilation, which continued even after sufficient oxygenation by 100% O2 inhalation. The infusion of aminophylline, an adenosine receptor blocker, not only increased PaCO2 from 35 to 39 mm Hg but also depressed the magnitude of hypoxic ventilatory response (HVR). After a surgical removal of the major fistulae, PaCO2 increased to 42 mm Hg. At this time, aminophylline increased the resting ventilation and slightly augmented the HVR value, which was opposite to the findings of preoperation. Dipyridamole, which potentiates endogenous adenosine by inhibiting its cellular uptake, increased the magnitude of HVR both before and after the operation. We propose that the hyperventilation observed in this case can at least in part be attributed to the ventilatory stimulation by endogenous adenosine, which presumably passed through the fistulae without being metabolized in the pulmonary circulation.

Adenosine↗

PubMed1993

[Bronchial asthma--airway inflammation and asthma--role of airway epithelium].

The importance of airway inflammation in the pathophysiology of bronchial asthma has been recognized recently. This inflammation is organized by the interaction between inflammatory cells and the cells which compose airway structures. We studied the role of airway epithelium in airway hyperresponsiveness and airway inflammation, which are the major characteristics of bronchial asthma, and demonstrated a close relationship between them. On the bases of these data and the data reported by many other researchers, and from the point of view of airway inflammation, we discussed the possible roles of airway epithelium in bronchial asthma.

Animals↗

PubMed1992

[Three cases of chronic respiratory tract lesions associated with adult T-cell leukemia (ATL)].

Three cases of chronic respiratory tract lesions as a complication of adult T-cell leukemia (ATL) are reported. Case 1 was seropositive for HTLV-1 on recent examination following treatment of bronchiolitis. Chest radiograph revealed over inflation of the lungs and bilateral diffuse small nodular shadows. Pulmonary function test resulted hypoxemia and mixed ventilation disorder. Pathological examination confirmed lymphocytic infiltration of the bronchiolar wall. Both clinically and pathologically the patient was diagnosed as having diffuse panbronchiolitis (DPB). Therefore, this case was considered to be the bronchiolar type of HTLV-1 associated bronchiolo-alveolar disorder (HABA). The other two cases with smoldering or chronic ATL presented with long-standing symptoms of productive cough due to chronic respiratory lesions. We consider that all three cases had HTLV-1 virus associated pulmonary lesions, but with different clinical and pathological presentations. Among 12 cases of bronchiolitis experienced at our hospital, three were positive for HTLV-1.

Adult↗

PubMed1992

[A case of Swyer-James syndrome with bilateral lesions].

A 16-year-old female was admitted for the treatment of bronchial asthma. She had a history of measles pneumonia at four years of age. Her chest radiograph revealed right unilateral hyperlucency. She was diagnosed as having Swyer-James syndrome from the results of computed tomography, pulmonary angiography, bronchoscopy, and perfusion-ventilation scintigrams, which revealed unsuspected bilateral involvement, and irregularity of severity and distribution. In addition, she had a hypoplastic right upper bronchus, pulmonary hypertension, pneumothorax, and bronchial asthma. The findings of bilateral involvement, irregular distribution, and bronchial lesions strongly suggest that the etiology in this case was damage to the airways caused by measles infection in childhood.

Adolescent↗