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Biomedical subjects

G Mogi

Publications and source records attributed to G Mogi.

At least 19 recordsLinked to original sources
PubMed1995

Immunological aspects of otitis media: present views on possibilities of immunoprophylaxis of acute otitis media in infants and children.

The article reviews, based on current knowledge of immunological events affecting the middle ear, the possibilities and prospects for the prevention of otitis media (OM) by immunologic measures. While pneumococcal capsular polysaccharide vaccines proved not to be effective against infant acute otitis media (AOM), pneumococcal conjugate vaccines provide good immunogenicity even in infants, and call for trials with better prospects of clinical efficacy. The other future approaches currently under development are vaccines against nontypable Haemophilus influenzae and Branhamella catarrhalis, anti-viral immunoprophylaxis, combinations of the above alternatives, or passive immunization. Also, the use of new routes or ways of immunization are under study. Furthermore, the ways to modify the present treatment practices of AOM to favour good immunologic responses in infants and children must be studied.

Acute Disease↗
PubMed1995

High incidence of Haemophilus influenzae in nasopharyngeal secretions and middle ear effusions as detected by PCR.

PCR was used to detect Haemophilus influenzae in samples of nasopharyngeal secretion and middle ear effusion (MEE). Nasopharyngeal secretions were collected from 102 patients with otitis media with effusion and from 111 healthy subjects. Eighty samples of MEE were collected from patients with otitis media with effusion. A pair of primers was designed to amplify a DNA segment of the gene encoding P6 outer membrane protein of H. influenzae. The amplified PCR product was detected with an internal probe that hybridized specifically to the P6 DNA of H. influenzae. Samples of MEE and nasopharyngeal secretion were also examined by a conventional culture method. The incidence of P6 gene DNA in nasopharyngeal secretions detected by PCR was about two times higher than that of H. influenzae detected by the conventional culture. Culture-positive samples were all positive in the PCR test. In MEEs, the rate of detection of the P6 gene DNA target was about five times higher than that of H. influenzae detected by the culture method. All patients who had P6 gene DNA in MEEs were found to have the DNA in nasopharyngeal secretions. These findings suggest that the presence of H. influenzae in MEEs and in nasopharyngeal secretions is more common than previously reported.

Bacteriological Techniques↗
PubMed1995

Effect of oxatomide on otitis media with effusion--an experimental study.

The therapeutic effect of oxatomide on experimental otitis media with effusion (OME) induced by secondary immune response was investigated in chinchillas. Oxatomide was administered daily in three different doses (5, 10, 30 mg/kg b.w.t.) for a period of 2 weeks, starting 2 days after the instillation of keyhole limpet hemocyanin (KLH) into the tympanic cavity. The severity of OME was assessed by observing the eardrum under a surgical microscope, by tympanography, and by histological findings. The concentrations of leukotriene C4 and LTD4 in middle ear effusion (MEE) were also measured, 7 days after the KLH instillation. It was found that oral administration of oxatomide in dosages of 10 and 30 mg/kg alleviated the experimental OME. The mean LTD4 concentration measured in MEE from chinchillas given 30 mg oxatomide was significantly lower than that measured in the control group. The radioactivity of 14C-labelled oxatomide in MEE and the autoradiographic findings revealed that orally administered oxatomide was rapidly absorbed from the digestive tract and transported to the middle ear via blood circulation. The findings suggest that the effect of oxatomide can be anticipated in patients with OME.

Acoustic Impedance Tests↗
PubMed1995

Immunology of the tympanic membrane.

Under normal conditions, tympanic membranes lack immunocompetent cells, except mast cells and Langerhans cells in the pars flaccida, and the annular and manubrial regions of the pars tensa. Lymphocytes migrate to these regions after the induction of immune-mediated otitis media, although the other regions of the pars tensa do not show the presence of these cells. Langerhans cells appear throughout the entire tympanic membrane, in case of otitis media. The unique features of the immunological aspect of the tympanic membrane are discussed.

Animals↗
PubMed1995

Three-dimensional investigation of the postoperative condition after ossiculoplasty with hydroxylapatite corp. (Running title; 3-D investigation of Corp).

From January 1985 to December 1993, at Oita Medical University, we have employed hydroxylapatite ceramic ossicular replacement prosthesis (Corp) for 42 ossiculoplasties for chronic otitis media with and without cholesteatoma and investigated the relationship between 3-dimensional condition of the prosthesis and hearing improvement after surgery according to the method of 3-D reconstruction technique as previously reported. The images of the middle ear and inner ear structures were traced on 4 or 6 tomograms of 2 mm thick slices from frontal view and input into the Nexus 6800 image processor. The 3-D images were reconstructed by using a 3-D reconstruction microsoft, TRI. The postoperative hearing improvement in ossiculoplasty with Corp was achieved in 23 (55%) of 42 ears. In 28 (67%) of 42 ears, Corp was found to be in the proper position on tomograms and to tilt upwards in 10 years (24%) and downwards in 3 ears (7%). In one case, the prosthesis was rejected through the tympanic membrane 23 days after surgery because the head of Corp was not covered with cartilage plate. In 19 (67%) of 28 ears, satisfactory hearing improvement was achieved, and Corp was well fitted to the tympanic membrane out of touch with other surrounding structures and vertical to the tympanic membrane, 3-dimensionally. In contrast, in 9 ears (33%) without improved hearing, the prosthesis was fixed in the proper position on the frontal plain, but it sifted backwards or forwards in 3-D reconstructed images.(ABSTRACT TRUNCATED AT 250 WORDS)

Ceramics↗
PubMed1994

Effect of terfenadine on substance P and vasoactive intestinal polypeptide concentrations in nasal secretions from patients with nasal allergy.

Before terfenadine treatment, the mean substance P and vasoactive intestinal polypeptide (VIP) concentrations in nasal secretions from nasal allergy patients tended to be higher than the values of healthy subjects. During terfenadine treatment, the mean substance P concentrations in nasal secretions from patients allergic to house dust or pollen were significantly decreased to 62 and 39% of the initial values, respectively. The mean VIP concentrations in nasal secretions from the house dust allergy patients and the pollen allergy patients were significantly decreased to 52 and 18% of the initial values, respectively. Plasma substance P and VIP concentrations were not affected by nasal allergic symptom and terfenadine treatment.

Adolescent↗
PubMed1994

Lymphocyte migration to the middle ear mucosa.

We investigated the migration of antigen-specific IgA-forming cells to the middle ear mucosa. Antigen-specific lymphocytes of IgA and IgG classes were induced in guinea pigs according to an immunization strategy previously described. From those animals, chromium 51-labeled lymphocytes of Peyer's patches and spleen were transferred to radiated chimera recipients. The radioactivity levels of the middle ears with antigenic and nonantigenic stimuli were significantly higher than those of the control ears (p < .05). Those levels of radioactivity were influenced neither by origins and subsets of transferred cells nor by antigenic stimuli to the mucosa (p > .05). Many labeled cells were observed in the middle ear effusion, while few were found in the inflamed mucosa. These findings suggest that in the early stage of inflammation, lymphocytes, including antigen-specific T and B cells, may be recruited from the blood circulation to the inflamed middle ear mucosa by nonspecific inflammatory processes that may mask antigen-specific factors in lymphocyte migration.

Animals↗
PubMed1994

Effect of S-carboxymethylcysteine on the clearance of middle ear effusion. An experimental study.

The therapeutic effect of S-carboxymethylcysteine (S-CMC) on otitis media with effusion was investigated by use of immune-mediated otitis media with effusion (OME) induced in chinchillas. The S-CMC was administered daily to individuals in two different doses (100 mg/kg and 200 mg/kg) for 2 weeks after the induction of immune-mediated otitis media. The severity of OME was evaluated by observation of the tympanic membrane under a surgical microscope, by tympanogram, and by histologic findings of the middle ear mucosa. Results of the study showed that the oral administration of S-CMC at a dose of 200 mg/kg of body weight is more effective than at a dose of 100 mg/kg in the clearance of middle ear effusions in experimental OME. An autoradiographic study using 14C-S-CMC revealed that orally administered S-CMC is rapidly absorbed by the digestive tract and transported to the tubotympanum via the circulation. The uptake and excretion by secretory cells were apparently greater in activated secretory cells. However, S-CMC does not act on the infiltrating cells to prevent the release of chemical mediators such as histamine and prostaglandin E2. This finding suggests that prophylactic use of S-CMC may not be anticipated.

Animals↗
PubMed1994

Surfactant-producing epithelium in the dorsal part of the cartilaginous eustachian tube of mice. Light, transmission, and scanning electron microscopic observations.

The nonciliated area in cartilaginous roof tubothelium of 14 conventional mice was examined histologically and classified as a modified transitional respiratory epithelium. On the free cell surface numerous short microvilli were found. On the lower roof surface in the midcartilaginous portion and especially near the pharyngeal orifice, a convoluted pattern of ridges and pits was observed. These structural peculiarities are interpreted as adaptive features, ensuring survival of the cells in a dynamic tubal environment. On the basis of systematic observations of the multilamellar bodies in the cytoplasm resembling the phospholipid lamellar bodies of pulmonary surfactant, which are discharged in the tubal lumen and to be found in the pits, it is suggested that the nonciliated cells are "specialized" surfactant-producing tubocytes. The synthesis of surfactant-precursors starts in the basal layer. Different phases of the secretory process were observed in the neighboring cells. This finding is related to the cell-cooperation constantly releasing the secretory product, and natural cell-turnover. Unlike the previously reported surfactant-producing cells in the lower tubothelium of other species, roof tubothelial cells of mice are morphologically similar to type II pneumocytes.

Animals↗
PubMed1994

Localized aerosol hyperthermia in patients with nasal allergy.

A double-blind study was performed to evaluate the efficacy, the safety and the usefulness of localized aerosol hyperthermia (LAH) in 57 patients with nasal allergy. We used two localized aerosol hyperthermia devices, the equipment (AH) with an insufflated aerosol of 43 degrees C and a placebo device (PH) with aerosol of 32 degrees C. In the evaluation of clinical efficacy, efficacy rates were 46.4% in AH and 3.7% in PH during 2 weeks, respectively, and 53.3% in AH and 7.7% in PH during 4 weeks, respectively. There was a significant difference (p < 0.01) between the two treatment groups. The usefulness rates were 63.3% in AH and 7.4% in PH for patients with nasal allergy, showing a statistically significant difference (p < 0.01). No patients dropped out of the study due to adverse effects. These results suggest that the LAH is a very useful instrument for the treatment of nasal allergy.

Aerosols↗
PubMed1993

Substance P and vasoactive intestinal peptide in nasal secretions and plasma from patients with nasal allergy.

To clarify the role of substance P (SP) and vasoactive intestinal peptide (VIP) in nasal allergy, we measured their concentrations in the nasal secretions and plasma of normal subjects and patients with nasal allergy to house dust and Japanese cedar pollen by competitive enzyme-linked immunoassay. The mean levels of SP (224 pmol/L) and VIP (41.6 pmol/L) in the nasal secretions of normal subjects were significantly higher than those in plasma (SP 3.04 pmol/L and VIP 1.04 pmol/L; p < .01). The mean levels of SP and VIP in the nasal secretions of the pollinosis group were significantly higher than those of the control group (p < .05 and p < .01), while the levels of the house dust allergy group were not higher than those of the control group. Intranasal allergen challenge significantly reduced SP levels in the nasal secretions of the allergy groups, while it did not influence VIP levels in the nasal secretions. These findings suggest that SP and VIP are actively secreted into the nose and may play an important role in the allergic reaction on the surface of the human nasal mucosa.

Adolescent↗
PubMed1992

Inhibition of nasopharyngeal colonization of Hemophilus influenzae by oral immunization.

Nontypeable Hemophilus influenzae organisms were inoculated into the nasopharynx of BALB/c mice immunized by oral administration of formalin-killed bacteria. Salivary antibodies and the colonization of H influenzae in the nasopharynx were investigated in order to clarify the effect of oral immunization. Salivary immunoglobulin A antibody titers against H influenzae were significantly increased by oral immunization, but salivary immunoglobulin G antibody titers were not. The bacteria inoculated into the nasopharynx were more rapidly eliminated in immunized mice than in control mice. The results suggest that oral immunization might be useful in preventing otitis media with effusion by inhibiting the colonization of the nasopharynx by pathogenic bacteria.

Administration, Oral↗
PubMed1992

Distribution of immunocompetent cells in the endolymphatic sac.

To better understand the role of immunocompetent cells in the defense mechanism of the inner ear, the distribution patterns of those cells were investigated in the endolymphatic sac (ES) of mice maintained in three different conditions: germ-free (GF), specific pathogen-free (SPF), and conventional (CV). In another experiment, the recruitment of lymphocyte subsets was examined in the ES of SPF rats undergoing a perilymphatic antigen challenge after systemic presensitization. In the ES of GF mice, no immunocompetent cells were found. In the ES of SPF and CV mice, cells positive for IgG, IgA, IgM, and Lyt-1 were present in much smaller numbers than in the nasal mucosa. Cells positive for Lyt-2 were not seen in the ES of any mice. In the ES of rats that underwent a perilymphatic antigenic stimulation after a systemic presensitization, B lymphocyte subsets (positive for IgG, IgA, IgM) were mobilized in increased numbers, and T cell subsets (helper/inducer and suppressor) were also found 1 week after perilymphatic antigen challenge. These results taken together suggest that the ES is not originally equipped to possess immunocompetent cells and mount an immune response, but that once it has been activated with the inner ear antigenic stimuli, the ES can be the active site of a local immune response of the inner ear.

Animals↗
PubMed1992

Experimental otitis media with effusion induced by middle ear effusion.

Experimental otitis media with effusion was induced in chinchillas by middle ear effusion, which was induced by an injection of immune complex into the tympanic cavity. To elucidate the pathogenesis of otitis media with effusion, cytologic and biochemical findings of the effusion and histopathology of the middle ear mucosa of effusion-induced chinchillas were compared with those of experimental otitis media with effusion induced by different procedures; eustachian tube obstruction, intratympanic inoculation of endotoxin, and immune reaction. No significant differences were seen in cytology, biochemistry, and histopathology among OMEs induced by these procedures. However, middle ear effusions, when compared with the corresponding sera, were proven to contain higher amounts of histamine and prostaglandin E2. These findings seem to demonstrate that middle ear effusion containing a large number of inflammatory mediators is essential for induction and prolongation of inflammatory reaction in the middle ear.

Animals↗
PubMed1992

[Seasonal fluctuations of substance P and vasoactive intestinal peptide concentrations in nasal secretions of patients with nasal allergy to Japanese cedar pollen].

Substance P (SP) and vasoactive intestinal peptide (VIP) concentrations in nasal secretions and plasma from patients with nasal allergy to Japanese cedar pollen and healthy volunteers were measured from Jan to Dec, 1991 using EIA established by us. Simultaneously, the numbers of airborne pollens of Japanese cedar and cypress were counted, and the relation to the SP and VIP concentrations in nasal secretions from the patients with nasal allergy to Japanese cedar pollen was studied. The mean SP concentration in nasal secretions from the patients with nasal allergy to Japanese cedar pollen in the pollination season was 81.9 +/- 48.4 fmol/mg protein, which was significantly higher than that in the non-pollination season (30.4 +/- 14.7 fmol/mg protein) (p < 0.01). Likewise, the mean VIP concentration in nasal secretions from the patients with nasal allergy to Japanese cedar pollen in the pollination season was 14.2 +/- 10.4 fmol/ml protein, which was significantly higher than that in the non-pollination season (4.2 +/- 3.0 fmol/mg protein) (p < 0.01). The SP and VIP concentrations in nasal secretions from the healthy volunteers were not affected by the scattering of pollens. The SP and VIP concentrations in plasma from the patients and the healthy volunteers were not affected by the scattering of pollens.

Adult↗
PubMed1992

Lymphocyte-mucosal interaction of the middle ear mucosa.

The middle ear mucosa possesses immunologic features similar to those of the peripheral mucosa sites in the common mucosal immune system and after mucosal immunization, antigenspecific IgA-forming cells appear in the inflamed mucosa of the tympanic cavity. Recent investigations suggest that lymphocyte migration to lymphoid tissues is regulated by lymphocyte-high endothelial venules (HEV) interaction. However, the lymphocyte migration mechanism to the middle ear mucosa is still unclear. We investigated whether or not organ-specific determinants which lymphocytes bind with are present on the middle ear mucosa by in vivo and in vitro lymphocyte adherence assays by using fluorescein-labeled lymphocytes from various lymphoid tissues. Many lymphocytes from Peyer's patches and hilar lymphnodes adhered on the inflamed middle ear mucosa with or without mucosal immunization, while these cells were not found on the normal tympanic mucosa. The number of the cells was smaller than that in the gastrointestinal mucosa. Lymphocyte adherence to the middle ear mucosa was not suppressed by anti-T cell antibody. These findings suggest that the middle ear mucosa possesses organ-specific mucosal determinants which B-lymphocytes selectively bind with, and that those determinants which regulate lymphocyte migration to the middle ear mucosa differ from those of other mucosae in the gastrointestinal tract.

Animals↗