Biomedical subjects

K Zayasu

Publications and source records attributed to K Zayasu.

7 recordsLinked to original sources

PubMed2000

Pulmonary tuberculosis and serum IgE.

Several recent studies indicate that mycobacterium or viral infection may reduce IgE levels or suppress atopy or both. The present study was undertaken to investigate whether Mycobacterium tuberculosis infection and its successful treatment down-regulate serum total IgE levels, a marker of a Th2 response, due to enhancement of a Th1 response in adult patients with tuberculosis (TB). We prospectively studied the changes in serum total IgE and DTH response to tuberculin, a marker of a Th1 response in 10 healthy controls, 20 patients with pulmonary TB, and 19 asthma patients without TB. Measurement of serum total IgE and tuberculin skin tests were performed before initiation of treatment and after successful completion of 6 months treatment in TB patients, and at the corresponding intervals in controls and asthmatics. The initial serum total IgE concentrations were significantly higher in TB patients than in healthy controls (282 +/- 26 U/ml (mean +/- s.e.m.) in TB patients versus 126 +/- 56 U/ml in controls; P = 0.03). However, serum total IgE concentrations significantly decreased (282 +/- 26 U/ml before versus 151 +/- 12 U/ml after treatment; P = 0.03) and tuberculin indurations significantly increased (23.6 +/- 1.8 mm before versus 29.6 +/- 2.1 mm after treatment; P = 0.04) in TB patients. In contrast, initial serum IgE concentrations and tuberculin indurations did not differ significantly from post-observation data in both healthy controls and asthmatics (P>0.30). The present study confirmed that immune responses to M. tuberculosis down-regulate a Th2 immune response, and might contribute to the decreased prevalence of allergic disorders.

Asthma↗

PubMed1997

Increased carbon monoxide in exhaled air of asthmatic patients.

Exhaled carbon monoxide (CO) concentrations were measured on a CO monitor by vital capacity maneuvers in asthmatic patients receiving or not receiving inhaled corticosteroids and in nonsmoking and smoking healthy control subjects. CO was detectable and measured reproducibly in the exhaled air of all subjects. The exhaled CO concentrations were higher in asthmatic patients not receiving inhaled corticosteroids (5.6+/-0.6 ppm, p < 0.001) and similar in asthmatic patients receiving inhaled corticosteroids (1.7+/-0.1 ppm) compared with those in nonsmoking healthy control subjects (1.5+/-0.1 ppm). Smoking healthy control subjects had the highest levels of exhaled CO concentration among the groups (21.6+/-2.8 ppm, p < 0.001). To examine whether inhaling corticosteroids reduce exhaled CO concentration in a given asthmatic patient, 12 patients with symptomatic asthma who were being treated by inhaled beta2-agonists alone underwent measurements of exhaled CO concentration before and 4 wk after the initiation of inhaled corticosteroid treatment. All patients had reductions in exhaled CO concentration (p < 0.001) and eosinophil cell counts in sputum (p < 0.01) that were accompanied by an improvement in airway obstruction. Changes in exhaled CO concentration were significantly related to those in the eosinophil cell counts in sputum (p < 0.001). The present study shows an elevation of exhaled CO in asthmatic patients that decreases with corticosteroid therapy. Increases in the exhaled CO levels therefore may reflect inflammation in the asthmatic lung.

Administration, Inhalation↗

PubMed1992

Opsonized zymosan decreases cytoplasmic motility of alveolar macrophages in dogs.

To examine the mechanisms of changes in alveolar macrophage (AM) activities caused by phagocytic stimulus, we studied the effect of opsonized zymosan (OZ) on cytoplasmic motility (CM) of AM from dog lungs in vitro. Four days after the instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the lower lobe bronchus, AM were harvested by broncho-alveolar lavage. AM were adhered to the bottom of plastic vials (10(6) cells of AM per each vial). Remanent field strength (RFS) from the AM containing Fe3O4 particles was measured immediately after magnetization. RFS decreased with time due to particle rotation (relaxation), which is related to cytoplasmic motility of AM. OZ (1-500 micrograms) decreased lambda 0 (the relaxation rate for the first min) in a concentration-dependent fashion. Neither BW755C (10(-5) M), indomethacin (10(-6) M), leupeptin (10(-5) M), bestatin (10(-5) M), nor superoxide dismutase (1000 U/ml) inhibited OZ (500 micrograms)-induced inhibitory effects on lambda 0, suggesting that cyclooxygenase and lipoxygenase products, serine, thiol enzymes, aminopeptidase and superoxide anion wer not responsible for OZ-induced effects. OZ (500 micrograms) significantly increased the intracellular concentration of Ca2+ (P less than 0.01). Likewise, OZ (500 micrograms)-induced effects on lambda 0 of AM were significantly inhibited by replacement of the medium with a Ca2+ free solution (P less than 0.01). These results imply that opsonized zymosan inhibits cytoplasmic motility of AM via external calcium influx.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗

PubMed1992

Capsaicin desensitization inhibits cigarette smoke-induced increase in cytoplasmic motility of alveolar macrophages in guinea pigs.

To study effects of cigarette smoke on the cytoplasmic motility (CM) of alveolar macrophages (AM), we measured remanent field strength (RFS) in guinea pigs with and without systemic capsaicin pretreatment in vivo. Four days after instillation of 3 mg/kg ferrimagnetic particles (Fe3O4) into the trachea, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time because of particle rotation (relaxation), which is thought to be correlated to CM of AM. The initial relaxation curve was fitted to an exponential function. The relaxation rate (lambda 0) increased during cigarette smoke inhalation and returned to baseline values within 5 min, and with the inhalation of the smoke of as many as three cigarettes, peak lambda 0 increased in animals without capsaicin pretreatment. However, cigarette smoke decreased lambda 0 with an increased number of cigarettes in animals with capsaicin pretreatment. Injection of nicotine or acetylcholine increased respiratory resistance to a degree similar to that observed with cigarette smoke, but it did not change lambda 0. However, substance P (SP) increased lambda 0, and repeated administration of SP produced a significant tachyphylaxis in animals with and without capsaicin pretreatment in a fashion similar to that noted with cigarette smoke inhalation. Acrolein decreased lambda 0 in animals with and without capsaicin. Colchicine inhibited the cigarette smoke-induced increase in lambda 0.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1990

Mechanisms of decrease in cytoplasmic motility of alveolar macrophages during immediate asthmatic response in dogs.

To study the cytoplasmic motility (CM) of alveolar macrophages (AM) during immediate asthmatic response, we measured remanent filed strength (RFS) in dogs in vivo after Ascaris suum-antigen (AA) inhalation. Four days after instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the right lower lobe bronchus, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time because of particle rotation (relaxation). Relaxation is thought to be correlated to CM of AM (J. Appl. Physiol. 55: 1196-1202, 1983). AA inhalation increased respiratory resistance (Rrs) in 10 dogs (responders; P less than 0.01), and did not change Rrs in five dogs (nonresponders; P greater than 0.50). The relaxation rate (lambda 0) significantly decreased because of AA inhalation in responders (P less than 0.01), whereas lambda 0 did not change in nonresponders (P greater than 0.50). Intravenous injection of indomethacin or diclofenac sodium (5 mg/kg) 30 min before AA inhalation completely inhibited the decrease in lambda 0 induced by AA inhalation, although both drugs did not inhibit the increase in Rrs (P greater than 0.10). In in vitro experiments, AM (5 x 10(6) cells) cells) harvested by bronchoalveolar lavage showed a significant dose-dependent decrease in lambda 0 with prostaglandins (PG) E1 and E2. However, histamine and platelet-activating factor increased lambda 0 significantly (P less than 0.01), whereas PGD2, PGF2 alpha, PGI2, thromboxane A2, leukotrienes B4, C4, and D4, and AA itself were without effect (P greater than 0.50). Furthermore, PGE2 aerosols mimicked AA-induced effects on AM.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗

PubMed1989

Acute effect of cigarette smoke on cytoplasmic motility of alveolar macrophages in dogs.

To study effects of cigarette smoke on the cytoplasmic motility (CM) of alveolar macrophages (AM), we measured remanent field strength (RFS) in dogs in vivo. Four days after instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the right lower lobe bronchus, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time due to particle rotation (relaxation), which is thought to be inversely related to CM of AM (J. Appl. Physiol. 55: 1196-1202, 1983). The initial relaxation curve was fitted to an exponential function. The relaxation rate (lambda 0) increased during cigarette smoke inhalation and returned to base-line values within 15 min. With the inhalation of the smoke of up to five cigarettes, peak lambda 0 was increased; with a further increase in the number of cigarettes, the effect of cigarette smoke decreased or disappeared. Nicotine injection and acetylcholine inhalation increased respiratory resistance to a degree similar to that observed with cigarette smoke but did not change lambda 0. However, either substance P (SP) or capsaicin injection increased lambda 0 in a fashion similar to that noted with cigarette smoke inhalation. Repeated administration of SP produced a significant tachyphylaxis of the effect, and capsaicin did not increase lambda 0 after the cigarette smoke-induced tachyphylaxis of the effect. Colchicine inhibited the cigarette smoke-induced increase in lambda 0. These results suggest that cigarette smoke increases CM of AM, probably through the release of tachykinins including SP from sensory nerves in the lung.

Acetylcholine↗

PubMedDate not supplied

Inhalation of road dust by residents in polluted areas.

From March 1985 to March 1989, pneumomagnetic field strength (PMFS) was measured in 579 healthy subjects who lived in areas where there was substantial road dust pollution. In response to the government's campaign to eliminate the use of studded tires, suspended road dust produced by studded tires during the snowy season in the downtown areas of Sendai, Japan, decreased from 191 micrograms/m3 in March 1985 to 116 micrograms/m3 in March 1989. Suspended road dust in nonpolluted areas varied from 11 to 15 micrograms/m3. Road dust retained in the lungs, which contained 3% iron, was magnetized from the surface of the chest wall, and the PMFS was measured. The proportion of subjects with an abnormally high initial PMFS at the first measurement was 7 to 15% from 1985 to 1989; however, the PMFS of subjects who had an initially high PMFS decreased during each succeeding year. These findings suggest that, despite a government campaign to eliminate studded tires, road dust pollution is still being inhaled by the residents.

Air Pollutants↗