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Biomedical subjects

Y Sakakura

Publications and source records attributed to Y Sakakura.

288 records · Page 16Linked to original sources
PubMedDate not supplied

Lysosomal thiol proteases in middle ear effusions.

Hydrolytic activity of lysosomal cathepsins B and H, and trypsin-like proteases in 115 middle ear effusions (MEEs, 40 serous and 75 mucoid) from chronic otitis media with effusion (OME) patients was measured and compared to that in plasma. The activity of both cathepsins in MEEs was significantly higher than that in plasma (p less than 0.01), and cathepsin B activity in mucoid MEEs was also significantly higher than that in serous MEEs (p less than 0.01). The activity of trypsin-like proteases was very weak in both MEEs and plasma. Profiles of various inhibitors indicated the qualitative difference of proteolytic enzymes between MEEs and plasma. Mucoid MEEs had significantly higher activity of thiol proteases than serous ones (p less than 0.01). Cathepsin B-like lysosomal thiol proteases, derived mainly from macrophages, could become a major proteolytic factor to perpetuate and amplify the inflammatory reaction of chronic OME.

Adult↗
PubMedDate not supplied

Immunologic responses against lipopolysaccharide of Hemophilus influenzae in patients with acute sinusitis.

The serum antibodies against lipopolysaccharide of Hemophilus influenzae were measured in acute and convalescent phase sera from 30 patients with acute maxillary sinusitis using enzyme-linked immunosorbent assay. Levels of antibodies in the maxillary antral secretions were also measured. In convalescent phase sera from 15 patients with acute sinusitis due to H influenzae, there was a threefold, 1.5-fold, and threefold increase in the geometric mean titers of IgG, IgM, and IgA, respectively. In antral secretions, titers were significantly higher (p less than .01) in culture-positive patients than in culture-negative patients for all antibodies. These data indicate that the immune system has the ability to respond systemically and locally with specific antibodies against lipopolysaccharide of H influenzae.

Acute Disease↗
PubMedDate not supplied

Hearing impairment in relation to viscoelasticity of middle ear effusions in children.

Both dynamic viscosity (eta') and elasticity (G') of middle ear effusion were measured with an oscillating sphere magnetic rheometer and compared with the degree of conductive hearing loss in 65 ears of 40 children. There was a significant correlation between eta' and the magnitude of the air-bone gap at 500 and 1,000 Hz, but there was no significant correlation between eta' and the magnitude of the air-bone gap at 2,000 or 4,000 Hz. No significant correlation was noted between G' and the magnitude of the air-bone gap at 500, 1,000, 2,000, or 4,000 Hz. These results indicate that the eta' of middle ear effusion has an effect on the amount of hearing impairment at frequencies below 1,000 Hz.

Child↗
PubMedDate not supplied

Ultrastructure of mucous blanket in otitis media with effusion.

We used transmission electron microscopy to study the mucous blanket of the promontory from children with otitis media with effusion. The vast majority of the epithelial cells were secretory, and the rest were ciliated. The mucous blanket consisted of the electron-lucent periciliary fluid and the mucous layer. In the mucous layer, two layers were identified: an inner layer with migrating cells, and an outer layer with specks. Moreover, there was a lucent zone over the nonciliated surface that was as high as the microvilli. The thickness of the periciliary layer was predominantly as great as that of the ciliary tips, which just make contact with the mucous layer; however, the mucous layer occasionally penetrated into the periciliary space. These findings indicated that there is a mucociliary dysfunction in the middle ear caused by a decrease in the number of ciliated cells, and an abnormal interaction between cilia and mucus that would interfere with ciliary movement. Thus, such a system would fail to transport the mucous blanket.

Biopsy↗
PubMedDate not supplied

Evaluation of nasal passage patency after antigen and histamine challenge in guinea pigs by acoustic rhinometry.

We investigated the effects of antigen and histamine on the nasal passage patency in guinea pigs with or without nasal allergy. The change of nasal patency was measured by acoustic rhinometry and nasal airway resistance. Acoustic reflections have been used in adult humans to determine nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. In order to measure nasal cavity dimensions in guinea pigs, we modified equipment for use in humans by decreasing sound tube dimensions, increasing sampling frequency, and applying a special nosepiece. The percent change of volume, minimum cross-sectional area, and nasal airway resistance showed the largest changes at 10 minutes after antigen challenge in sensitized guinea pigs. There was a significant correlation between the individual percent change of nasal airway resistance and volume or minimum cross-sectional area. Histamine, 10(2) to 10(5) micrograms/mL, caused a dose-dependent reduction in percent change of volume in the challenged side of nonsensitized guinea pigs, but not in the opposite side. These results indicate that the noninvasive acoustic reflections technique is useful in small experimental animals, especially to assess the effect of nasal cavity dimensions after the challenge of antigen or nonspecific stimuli.

Adult↗
PubMedDate not supplied

The effect of leukotriene D4 on the patency of nasal passage in the guinea pig.

We investigated the effect of leukotriene D4(LTD4) on the patency of the nasal passage in nonsensitized and sensitized guinea pigs (GPs). The change in nasal patency was measured by acoustic rhinomanometry (AR). The change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction at 30 minutes and 6 hours after instillation of LTD4 in nonsensitized GPs. These findings were also seen in nonsensitized and sensitized GPs with systemic administration of carboxyl cellulose. However, neither nonsensitized nor sensitized GP with systemic administration of benzopyren hemihydrate(ONO-1078) showed any changes in nasal patency. These results indicated that the LT was a potent medication to induce nasal obstruction of late reaction in GP.

Airway Resistance↗
PubMedDate not supplied

Monoclonal antibody-detectable carbohydrate epitopes of human nasal secretions are differentially expressed in tissue and diseases.

To study the differential carbohydrate expression of airway secretions, we have produced a series of monoclonal antibodies that recognize human nasal secretory cell products. Mice were immunized with purified nasal secretion from patients with chronic sinusitis (CS) and hybridomas were selected by ELISA and immunohistochemical staining of the maxillary sinus mucosa from patients with CS. Eighteen antibodies were obtained. Antibody HCS 18 reacted with epithelial goblet cells, antibody HCS 4, 5, 6, and 16 stained submucosal gland cells, and antibody HCS 13 and 15 reacted with epithelial goblet cells, submucosal gland cells, and endothelial cells of vessels. The other eleven antibodies recognized epithelial goblet cells and submucosal gland cells. Cross-reactivity of these antibodies with secretory cells in other organs and in other species was determined and the different staining pattern was observed between upper and lower airway tissue, suggesting that secretory products from upper and lower airways may be different. Reactivity of the antibodies with nasal secretory cells was also examined in patients with perennial allergic rhinitis (AR) and normal subjects. Antibody HCS 18 weakly reacted with nasal glands in the tissue from CS and AR patients, but minimally reacted with gland cells in normal tissue. Antibody HCS 1 and 7 partially lost their reactivity with nasal epithelium of inferior turbinate from normal subjects and AR patients. These antibodies may be useful to study nasal secretions.

Adolescent↗
PubMedDate not supplied

Acoustic rhinometry evaluation of nasal response to histamine and antigen in guinea pigs.

The effects of antigen and histamine on the changes of nasal passage patency in 112 guinea pigs with or without allergic rhinitis were evaluated by acoustic rhinometry. The percent change of volume from the nostril to 2 cm into the nasal cavity showed significant reduction of 31.10 +/- 4.11% at 10 minutes and 31.10 +/- 4.11% at 30 minutes after antigen challenge in sensitized guinea pigs. The pretreatment with ketotifen, an H1-histamine receptor antagonist as well as mast cell stabilizing drug, blocked dose-dependently the effects of antigen on those changes in volume. Furthermore, instillation of 10(4) micrograms/mL histamine reduced significantly nasal passage patency to 33.77 +/- 4.63% at 10 minutes and 42.76 +/- 3.32% at 30 minutes after challenge compared with that before challenge and ketotifen inhibited the effects of histamine, which indicated that histamine is an important mediator of allergic upper airway responses in guinea pigs. These results show that acoustic rhinometry is a useful technique to assess the nasal blockade in allergic guinea pigs.

Acoustics↗
PubMedDate not supplied

Accuracy of measurement of acoustic rhinometry applied to small experimental animals.

Nasal obstruction is one of the major symptoms of allergic rhinitis. In the study of the mechanism of nasal obstruction, experiments on animal are useful. In adult humans, acoustic rhinometry has been used to evaluate nasal obstruction by determining nasal cavity dimensions in terms of cross-sectional areas as a function of the distance from the nostril. We modified the equipment used on humans to assess dimensions of nasal airway geometry of small experimental animals. The purpose of this study was to investigate the accuracy of measurement of the modified acoustic rhinometry applied to small experimental animals using nasal cavity models and guinea pigs. Measurement of the nasal cavity models (made of cylindrical silicone tubes) showed that the acoustic rhinometry estimated 85.5% of actual area and 79.0% of actual volume. In guinea pigs, nasal cavity volume determined by the acoustic rhinometry was 73.7 +/- 20.0% of actual volume. The actual volume was estimated by impression material instilled into the nasal cavity of the animals (IM volume), and volume determined by acoustic rhinometry significantly correlated with IM volume. Furthermore, there was a significant negative correlation between the volume and nasal airway resistance in guinea pigs. Measurement of the nasal airway resistance is the method frequently used in the evaluation of the nasal obstruction in guinea pigs. These results suggest that acoustic rhinometry is useful in evaluating nasal obstruction in small experimental animals.

Acoustics↗
PubMedDate not supplied

Nasal mucociliary clearance under various conditions.

We applied the tagged-particle method or the saccharin method or both to the nasal mucociliary clearance. There was no effect of ageing on the transport time of saccharin in control subjects of ages under 60, and 70% of control subjects of ages more than 60 had the same transport time as that obtained in younger control subjects. The significant inverse correlation between the mucociliary transport rates with the particle method and the transport time with the saccharin method were established in control subjects, but not, however, in patients with chronic sinusitis. The mucociliary transport rates were measured under non-physiologic conditions of the nose: laryngectomy, chronic sinusitis, Sjögren's syndrome, and Kartagener's syndrome.

Adolescent↗
PubMedDate not supplied

Lysosomal thiol proteases (cathepsin B-like proteases) in serous middle ear effusions from adult patients.

Hydrolytic activity of cathepsins B, H and trypsin-like proteases was measured in 38 serous middle ear effusion (MEE) samples. The concentrations of (alpha 1-AT) and alpha 2-macroglobulin (alpha 2-M) were also quantitated. The mean value of cathepsin B activity was 25.0 +/- 20.7 RFU and that of cathepsin H was 14.3 +/- 3.0--both significantly higher than those in plasma (1.8 +/- 0.4 RFU, 1.2 +/- 0.3 RFU, p less than 0.005). Very low trypsin-like protease activity could be observed. The mean concentrations of alpha 1-AT and alpha 2-M were 368 +/- 94.8 mg/dl and 57.5 +/- 57.3 mg/dl. The bulk of alpha 1-AT in MEEs was occupied by free alpha 1-AT, which can saturate exogenous trypsin. Due to the very low molar concentration of alpha 2-M in MEEs, thiol proteases (mainly cathepsin B) could be a possible major factor inflicting proteolytic injury on the middle ear mucosa and reflecting the severity of the inflammatory process.

Adult↗
PubMedDate not supplied

Cathepsin B-like thiol proteases and collagenolytic proteases in middle ear effusion from acute and chronic otitis media with effusion.

Hydrolytic activity of cathepsin B-like thiol proteases and collagenolytic proteases was measured in middle ear effusions (MEE) from pediatric patients with acute and chronic otitis media with effusion (OME). Both activities were significantly higher in MEEs from acute OME than those from chronic OME (p less than 0.01). The ratio of hydrolytic activity in the extracellular portion to the total activity in MEEs from chronic OME was also analysed in both proteases. The ratio ranged from 20 to 100% in individual cases, indicating that the degree of the release of lysosomal thiol proteases including collagenolytic proteases from leukocytes is variable in MEEs with chronic OME. The kinetics of lysosomal thiol proteases including collagenolytic proteases in acute OME seems to be much more active than that in chronic OME, and the presence of these thiol proteases appears to be an important factor leading to chronic OME.

Acute Disease↗
PubMedDate not supplied

Lymphocyte subsets of maxillary mucosa in chronic inflammation.

Subsets of infiltrating lymphocytes within maxillary sinus mucosae of patients with chronic sinusitis were investigated by immunoperoxidase staining of frozen sections with the use of monoclonal antibodies. The most commonly observed infiltrating cell type was suppressor/cytotoxic T cells (CD8+) and smaller subpopulations of lymphocytes were helper/inducer T cells (CD4+) and B cells (CD20+). Variable numbers of HLA-DR+ cells were commonly observed in the lamina propria. The fibrous type of chronic sinusitis was found to have more suppressor/cytotoxic T cells (CD8+) and lower CD4/CD8 ratio than the other histopathological types.

Adult↗
PubMedDate not supplied

Nasal mucociliary clearance in Sjögren's syndrome. Dissociation in flow between sol and gel layers.

Nasal mucociliary clearance was measured with two methods in 8 patients with Sjögren's syndrome and in 6 normal subjects. The movement of two different tracers placed 1.5 cm posterior to the inferior turbinate tip was measured respectively. The transport rate of a 500 microns anion resin particle tagged with 99mTc was measured. The clearance of 10 microliters saline labelled with 99mTc was monitored and the clearance rate was calculated. Whereas the measurement with the particle method revealed the lowered transport rate in Sjögren's syndrome, measurement with the saline method did not reveal any difference in clearance rate between the two groups. Since the former method measures the transport of particle in the gel phase (the outer mucous layer) and the latter measures the clearance of both gel and sol (periciliary fluid) layers, it is postulated that there is a dissociation of flow between sol and gel layers in Sjögren's syndrome.

Anion Exchange Resins↗
PubMedDate not supplied

Effect of atropine on nasal mucociliary clearance.

To investigate the effect of atropine on mucociliary function, nasal mucociliary clearance was measured with two methods in eight healthy men before and after subcutaneous injection of atropine sulphate. The movement of two different tracers placed 1.5 cm posterior to the inferior turbinate tip was measured. The transport rate of a resin particle tagged with 99mTc was measured. The clearance of 10 microliters saline labelled with 99mTc was monitored and the clearance rate calculated. Whereas atropine lowered the resin particle transport rate, the saline method did not reveal any difference in clearance rate after injection of atropine. Since the former method measures the transport of particles in the gel phase (the outer mucous layer) and the latter measures the clearance of both gel and sol (periciliary fluid) layers, it is postulated that the slowing of mucociliary transport by atropine is due to alterations in the gel layer.

Adult↗
PubMedDate not supplied

Effect of lipopolysaccharide of Haemophilus influenzae on ciliary activity of the human nasal mucosa and bullfrog palate clearance.

The influence of lipopolysaccharide (LPS) of Haemophilus influenzae on the ciliary activity of human nasal mucosa was first studied using both a photo-oscillographic apparatus and by bullfrog palate clearance. Neither modification of ciliary activity nor change in bullfrog palate clearance was observed in the early phase after the administration of LPS.

Animals↗
PubMedDate not supplied

Activities of antiplasmin and antiplasminogen activator in serous middle ear effusions.

Antiplasmin and antiplasminogen activator activities in serous middle ear effusion (MEE) collected from adult patients were measured to analyze the kinetics of antifibrinolytic activity of protease inhibitors. No trypsin, plasmin, and plasminogen activator (PA) activity could be detected in the pooled serous MEE by either the fibrin plate method or the fluorometric assay. Antiplasmin activity in serous MEE was lower than that in plasma. The MEE had no antiurokinase activity. These findings indicate that 1) serous MEE has residual antifibrinolytic activity which may be attributed to mainly antiplasmin activity of unsaturated plasmin inhibitors and not to anti-PA activity, and 2) that serous MEE contains no secretory urokinase inhibitors.

Adult↗