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Biomedical subjects

S Yasuoka

Publications and source records attributed to S Yasuoka.

At least 55 records · Page 3Linked to original sources
PubMed1990

Significance of thrombin in bleomycin-induced pulmonary fibrosis.

To clarify the role of thrombin in fibroblast growth and the development of pulmonary fibrosis in bleomycin-induced interstitial lung disease, we examined the relationship of thrombin activity to fibroblast growth-stimulating activity (FGA) in bronchoalveolar lavage fluid (BALF) from bleomycin-treated rats. Male Wistar rats were given a single intratracheal injection of bleomycin, bronchoalveolar lavage was performed 2, 6 and 15 days later, and the BALF was assayed for thrombin activity and FGA. Higher FGA than the control value was detected in the BALF from rats on Day 6 after bleomycin administration. In bleomycin-treated rats, thrombin activity in the BALF was significantly elevated on Day 2, and maximal on Day 6. The FGA of the BALF from bleomycin-treated rats on Day 6 was significantly decreased by its treatment with various thrombin inhibitors, such as alpha 1-antitrypsin, antithrombin III, hirudin and MD-805. On ammonium sulfate fractionation most of the thrombin activity was recovered in the fraction of 35-50% saturation in which most of the FGA was detected. These results suggest that the FGA of the BALF from bleomycin-treated rats was at least partly due to thrombin, and that thrombin is responsible, at least in part, for fibroblast growth and pulmonary fibrosis in bleomycin-induced interstitial lung disease.

Animals↗
PubMed1990

[Variety of neutrophil chemotactic factors in the respiratory tracts in patients with respiratory diseases].

We measured NCF activity and examined the characteristics of NCF in bronchoalveolar lavage (BAL) fluid, sputum and culture media of alveolar macrophages. Several kinds of NCF were detected in BAL fluid obtained from normal volunteers, and at least a part of these NCF was thought to be derived from alveolar macrophages. NCF activity, especially complement-derived NCF, was increased in BAL fluid and in sputum obtained from patients with chronic respiratory tract infection. In patients with idiopathic interstitial pneumonia, alveolar macrophage-derived NCF as well as complement derived NCF were increased in BAL fluid. These results indicate that different types of NCF may increase in response to the disease state or pathogenesis, and play important roles in neutrophil accumulation in the respiratory tract.

Aged↗
PubMed1990

[Lung surfactant apoprotein (LSP) content of sputum samples from patients with chronic airway diseases].

LSP contents of sputum samples from patients with chronic airway diseases were measured by an enzyme-linked immunosorbent assay (ELISA) kit which was designed by Kuroki et al to examine whether a substance identical to lung surfactant contained in alveolar lining layer, is also contained in respiratory tract fluid or not in the ELISA kit. One antibody to LSP was conjugated to peroxidase and another one to LSP was fixed onto a bead. A neo-anionic detergent, Triton X-100 and an anionic detergent, sodium dodecyl sulfate (SDS) were added to extraction medium to separate LSP from lung surfactant, and LSP reaction of sputum sample was maximal when the ratio of Triton X-100 to SDS was in range of 1 to 4. Airway mucous glycoprotein (AMG) purified from sputum sample did not show any LSP reaction. In CsCl density gradient ultracentrifugation of whole sputum, the LSP reaction was detectable only in the top fraction with density of about 1.40 and AMG was located in the fraction with a density of about 1.50. These results indicate that the LSP reaction of sputum sample is not due to false reaction caused by nonspecific binding of viscous AMG to the two antibodies to LSP, but to the existence of LSP. Therefore it was concluded that lung surfactant is contained in respiratory tract fluid. In general, the LSP concentrations in sputum samples were lower in purulent sputa than in mucoid or mucopurulent sputa, and lower in patients with diffuse panbronchiolitis and bronchiectasia than in those with pulmonary emphysema and chronic bronchitis. It was shown that LSP was hydrolyzed by neutrophil leucocyte homogenate. These results suggest that LSP content of sputum is influenced by various factors such as infection and disease in the respiratory tract, and thus is useful to estimate pathological states of chronic airway diseases.

Aged↗
PubMed1990

[Role of alveolar macrophages and neutrophils in the defense system against infection of Pseudomonas aeruginosa in the respiratory tract and the effect of derivative of muramyl dipeptide].

We investigated the role of alveolar macrophages and neutrophils on the defense system against infection of Pseudomonas aeruginosa (P. aeruginosa) in the lower respiratory tracts of rats. Intratracheal inoculation of formalin-inactivated P. aeruginosa to normal rats showed an increased number of neutrophils in bronchoalveolar lavage (BAL) fluid obtained at 24 hours after the inoculation. This response of neutrophils was induced by intravenous administration of MDP-Lys, which is muramyl dipeptide. Phagocytic activity of neutrophils for P. aeruginosa was higher than that of alveolar macrophages, indicating that neutrophils are essential phagocytes in the defense system against P. aeruginosa infection in the lower respiratory tract. Alveolar macrophages released neutrophil chemotactic factor after phagocytosis of P. aeruginosa. This function of alveolar macrophages was increased by MDP-Lys administration. These results indicated that alveolar macrophages play an important role in neutrophil accumulation by release of neutrophil chemotactic factor after the P. aeruginosa phagocytosis in the lower respiratory tract. Moreover MDP-Lys can amplify the neutrophil-dependent defense system against P. aeruginosa by activation of the alveolar macrophage function in vivo.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

Sodium Stimulates Growth of Amaranthus tricolor L. Plants through Enhanced Nitrate Assimilation.

Effects of Na application on the capacity of NO(3) (-) assimilation were studied in Na-deficient Amaranthus tricolor L. cv Tricolor plants. On day 30 after germination, Na-deficient A. tricolor plants received either 0.5 millimolar NaCl or KCl. The level of nitrate reductase activity doubled within 24 hours by the addition of Na and the enhanced level was maintained thereafter. When the plants were exposed to 2 millimolar (15)NO(3) (-), total (15)N taken up by the plants was greater in the Na-treated plants than in the K-treated plants within 24 hours of the Na treatment. Incorporation of (15)N into the 80% ethanol-insoluble nitrogen fraction of the Na-treated plants in the light period was about 260% of those of the K-treated plants indicating greater capacity of NO(3) (-) assimilation in the Na-treated plants. From these results, it was demonstrated that Na application to the Na-deficient A. tricolor plants promoted NO(3) (-) reduction and its subsequent assimilation into protein, resulting in growth enhancement.

Journal Article↗
PubMed1989

Role of alveolar macrophages in the neutrophil-dependent defense system against Pseudomonas aeruginosa infection in the lower respiratory tract. Amplifying effect of muramyl dipeptide analog.

Alveolar macrophages are thought to be important in immune or inflammatory reactions. We investigated the role of alveolar macrophages in defense against Pseudomonas aeruginosa infection in the lower respiratory tract. Intratracheal inoculation of formalin-inactivated P. aeruginosa (1 x 10(8)-1 x 10(10) organisms) into normal rats resulted in increase in the number of neutrophils in the bronchoalveolar lavage (BAL) fluid obtained 24 h later. The phagocytic activity of neutrophils for P. aeruginosa was higher than that of alveolar macrophages. These findings indicate that neutrophils are essential for phagocytosis of P. aeruginosa in the lower respiratory tract. On incubation with P. aeruginosa, alveolar macrophages released neutrophil chemotactic factor (NCF) dose-dependently. MDP-Lys(L18), a muramyl dipeptide analog, stimulated alveolar macrophages to phagocytize P. aeruginosa and stimulate the release of NCF from alveolar macrophages in vitro and enhanced the neutrophil response to inoculated P. aeruginosa in vivo. These results indicate that alveolar macrophages are important in initiating the neutrophil-dependent defense system against P. aeruginosa by releasing NCF and that MDP-Lys(L18) can amplify the defense system.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1989

[Production of fibronectin and PGE2 by cultured human alveolar macrophages].

Production of fibronectin (Fn) and prostaglandin E2 (PGE2) by human alveolar macrophages (AM) which were obtained by bronchoalveolar lavage was studied in vitro. AM obtained from patients with idiopathic interstitial pneumonia (IIP) produced much more Fn than those from normal volunteers but produced less amounts of PGE2. We also tested the effect of lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA), zymosan and albumin-anti albumin complex (alb-anti alb) on production of Fn and PGE2 from AM. LPS, PMA and zymosan suppressed Fn production but stimulated PGE2 production by AM from patients with IIP but indomethacin reversed the suppressive effect of LPS, PMA and zymosan on Fn production. On the contrary, alb-anti alb stimulated Fn production by AM. Furthermore, exogenous PGE2 suppressed Fn production by AM from patients with IIP in a dose-dependent manner. These data suggest that Fn production by AM may be changed by different stimuli or different states of disease, and there is close relationship between the production of Fn and PGE2 by AM.

Dinoprostone↗
PubMed1989

[Investigation of intracavernous injection of papaverine for erectile impotence].

Forty milligrams papaverine HCl was intracavernously injected to 28 patients with erectile dysfunction for diagnosis and treatment in 14 cases in which it was injected a few times. We designed a brief manual method for measurement of penile hardness by artificial erection. Twenty of the patients corresponding to 71.4%, reacted, but only 16 (57.1%) had efficient erection for possibility of coitus. It was useful for the diagnosis of vascular dysfunction with dorsal penile arterial pulse sound examination in impotence. It was useful for the cases of small vascular impediment with preservation of nerve supply after the operation of intrapelvic malignancies, and self injection might be possible, but on the other hand, it had no effect for the patients of advanced age with vascular impediment and diabetes mellitus neuropathy, and with arteriosclerosis.

Adult↗
PubMed1987

PGE2 and PGF2 alpha content in bronchoalveolar lavage fluid obtained from patients with eosinophilic pneumonia.

Cell differential, prostaglandins (PGs) E2 and F2 alpha in the bronchoalveolar lavage fluid (BALF) in two patients with eosinophilic pneumonia were measured at different times in the course of the disease. Results showed markedly increased numbers of eosinophils and increased content of prostaglandin (PG) E2 in BALF obtained from the patients with eosinophilic pneumonia compared to that of normal volunteers. Interestingly, the increased content of PGE2 in BALF obtained from the patients reverted to normal range with corticosteroid treatment. This change in PGE2 content in BALF was accompanied by normalization of number and percentage of eosinophils in BALF. These findings indicated that PGE2 level in lower respiratory tract of patients with eosinophilic pneumonia may be related to an increased number of eosinophils.

Adult↗