Search PubMed⌕ Search

Biomedical subjects

Y Sakakura

Publications and source records attributed to Y Sakakura.

At least 55 records · Page 3Linked to original sources
PubMed1999

Reconstruction of pleomorphic adenoma of the salivary glands in three-dimensional collagen gel matrix culture.

The morphogenesis of salivary gland pleomorphic adenoma was examined in vitro using three-dimensional (3-D) collagen gel culture. Pleomorphic adenoma cells were isolated from three parotid gland tumours and cultured as monolayers, after which they were subcultured in floating-collagen gel sandwiches. Cells cultured in both conditions were immunohistochemically characterized and compared using antibodies against various proteins representative of each histological component of salivary glands. Monolayers had myoepithelial characteristics, being positive for vimentin and alpha-smooth muscle actin. In collagen gels, however, the cells assembled in epithelial nests, showing an architecture similar to that of pleomorphic adenoma. The nests were composed of duct-lining epithelial cells that were positive for epithelial markers, surrounded by myoepithelial cells. Collagen gel culture induces multidirectional differentiation of adenoma cells, suggesting that pleomorphic adenomas originate from stem or reserve cells.

Actins↗
PubMed1999

Involvement of tenascin-C in proliferation and migration of laryngeal carcinoma cells.

Tenascin-C (TN-C) is an extracellular matrix glycoprotein upregulated in various pathological processes. In this study, we investigated its distribution in dysplasia and carcinoma of the human larynx using immunohistochemistry and in situ hybridization (ISH) techniques. In all cancer tissues, TN-C immunostaining was markedly increased in the stroma, especially around the cancer cell nests. In addition, cytoplasmic staining of cancer cells was also observed in 62.5% of the invasive cases, the cells being distributed in the periphery of the nests adjacent to the stroma. TN-C mRNA signals in cancer cells were detected in all six cases examined by ISH. Furthermore, in vitro evaluation of the roles of TN-C demonstrated an increase in the proliferating cell fraction in a dose-dependent manner. In a wound closure assay, the addition of TN-C promoted migration. We conclude that TN-C secreted by cancer cells may be involved in their proliferation and migration in an autocrine fashion.

Carcinoma in Situ↗
PubMed1999

Expression and localization of histamine H2 receptor messenger RNA in human nasal mucosa.

BACKGROUND: Histamine is an important chemical mediator in allergic rhinitis. Histamine H2 receptor (H2R) stimulation controls histamine release and mediates mucus secretion, suggesting that H2R might play some role in allergic rhinitis. OBJECTIVE: The objective of this study was to examine whether H2R mRNA expression is increased in patients with allergic rhinitis compared with normal subjects and to determine the localization of H2R mRNA in the human nasal mucosa. METHODS: We extracted RNA from scrapings of the inferior turbinate mucosa of 11 patients with allergic rhinitis. H2R and beta-actin mRNA were amplified by RT-PCR. In situ hybridization with a digoxigenin-labeled H2R cRNA probe was performed on surgical specimens of nasal turbinate of patients with allergic rhinitis. RESULTS: The mean +/- SD of H2R/beta-actin ratios were 0.12 +/- 0.16 for the scrapings of normal subjects and 0.35 +/- 0.20 for the scrapings of patients with allergic rhinitis; the difference was statistically significant (P <.01). H2R mRNA was localized in the epithelium, serous cells, and mucous cells. CONCLUSION: These data suggest that H2R mRNA is localized in the epithelium and the submucosal glands and that increased H2R may be playing some role in patients with allergic rhinitis.

Actins↗
PubMed1999

Histamine H1 receptor and reactivity of the nasal mucosa in sensitized guinea pigs.

OBJECTIVE: Nasal Hypersensitivity to histamine is higher in allergic patients than that in normal control, suggesting that affinity and/or density of H1 receptors in nasal mucosa may be increased in patients with allergic rhinitis. The purpose in this study is to examine the correlation between the hyperresponsiveness and number of histamine H1 receptors in guinea pig nasal mucosa. METHODS: Guinea pigs were sensitized by DNP-Ascaris antigen. To block histamine H1 receptors, ketotifen was used and the number of receptors was counted by receptor binding assay technique. These data were compared with nasal airway volume (VOL) assessed by acoustic rhinometry of the same animals to know whether the number of H1 receptors is correlated to the nasal responsiveness to the antigen, or not. Eighty animals were divided into five groups which are composed of nonsensitized and sensitized group pretreated with saline, 0.1, 1.0 and 10 mg/kg of ketotifen, respectively. RESULTS: The number of H1 receptors (Bmax) was significantly increased in sensitized group compared with that in control. It decreased dose dependently by pretreatment of ketotifen. The percent change of VOL showed - 31.1 +/- 4.1% at 10 min and - 42.9 +/- 4.1% at 30 min after antigen challenge in sensitized animals. This was dose dependently inhibited by ketotifen. There was a highly inverse correlation between VOL and Bmax (r = -0.708, P< 0.0001). CONCLUSION: These results suggest that sensitization increases the number of histamine H1 receptor, and that increased number of H1 receptor in nasal mucosa in sensitized guinea pigs may be one of the causes of nasal hyperresponsiveness to antigen.

Administration, Oral↗
PubMed1999

Expression of histidine decarboxylase messenger RNA and histamine N-methyltransferase messenger RNA in nasal allergy.

BACKGROUND: Histamine is an important chemical mediator in allergic rhinitis. Histamine is synthesized by L-histidine, catalysed by L-histidine decarboxylase (HDC) and metabolized mainly by histamine N-methyltransferase (HMT). The patients with allergic rhinitis may have altered histamine metabolism in the nasal tissue. OBJECTIVE: The objective was to compare the expression of HDC mRNA and HMT mRNA in nasal mucosa with normal individuals and patients with allergic rhinitis. METHODS: We extracted RNA from scrapings of inferior turbinate mucosa of 11 patients with allergic rhinitis and from 11 normal subjects and from surgically dissected inferior turbinate mucosa of 11 patients. HDC, HMT and beta-actin mRNA were amplified by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The mean +/- SD of HDC/beta-actin ratios were 0.58 +/- 0.28 for the scrapings of normal subjects, 0.93 +/- 0.38 for the scrapings of the patients with allergic rhinitis and 1.41 +/- 0.26 for the inferior turbinates of the patients with allergic rhinitis. The mean +/- SD of HMT/beta-actin ratios were 1.66 +/- 0.27 for the scrapings of normal subjects, 0.93 +/- 0.20 for the scrapings of the patients with allergic rhinitis and 0.65 +/- 0.28 for the inferior turbinates of the patients with allergic rhinitis. The differences among the three groups were statistically significant. CONCLUSIONS: Increased HDC mRNA expression and decreased HMT mRNA expression may be playing some role in the hyperresponsiveness of patients with allergic rhinitis.

Actins↗
PubMed1999

Acceptance of skin allografts in pigs by portal venous injection of donor bone marrow cells.

OBJECTIVE: To confirm in pigs whether a new method for organ allografts, originally established in mice by the authors, might be applicable to humans. SUMMARY BACKGROUND DATA: The authors recently established a new method for organ allografts in mice that includes the injection of donor bone marrow cells (BMCs) using the portal vein (PV), followed by the administration of cyclosporin A (CsA) on days 2 and 5, and the intravenous injection of BMCs on day 5. In the present study, they modify this method (a single-day protocol) and apply it to pigs. METHODS: Allogeneic BMCs of donor pigs were injected using the PV (a superior mesenteric vein). The skin grafting was carried out on the day of the PV injection. The recipient pigs received donor grafts, autologous grafts, and third-party grafts at the same time. In addition, an open wound was made as the epithelized control. Full-thickness skin grafts were harvested from the dorsal wall of the donors. CsA (10 mg/kg) was injected intramuscularly into recipient pigs on days 2 and 5 after the PV injection. RESULTS: One hundred percent of skin grafts survived for >300 days when donor BMCs were injected using the PV (n = 6). However, the skin grafts of the three pigs that had received BMCs using the intravenous route were rejected within 3 to 4 weeks after transplantation. The third-party skin grafts showed necrotic changes on day 21 after transplantation. CONCLUSIONS: One hundred percent of skin allografts can be obtained, even in pigs, by injecting donor BMCs using the PV, carrying out skin allografts, and administering CsA on days 2 and 5. This single-day protocol would be of great advantage for human organ transplantation.

Animals↗
PubMed1999

Analysis of HLA antigens in Japanese patients with chronic sinusitis.

OBJECTIVES: Genetic factors likely play a role in the etiology of chronic sinusitis and this disease is often associated with diffuse panbronchiolitis, which is strongly associated with HLA B54 antigen. The purpose of this study is to examine whether genetic factors are involved in the pathogenesis of chronic sinusitis. STUDY DESIGN: Eighty-two Japanese patients with intractable chronic sinusitis were selected on the basis of the following criteria: 1) persistent mucous or mucopurulent nasal discharge and/or postnasal dripping for longer than 3 years and 2) opacification in bilateral maxillary sinuses and ethmoid cells in plain X-ray films. METHODS: Both class I and class II HLA antigens were analyzed by conventional microcytotoxicity assays in these patients and 176 healthy control subjects. RESULTS: In class I antigens, B54 antigen significantly increased in the patient group (antigen frequency = 29.3%, relative risk = 3.23, corrected P value = .037) compared with normal control group (antigen frequency = 11.4%). For class II antigens, no antigens were significantly increased. CONCLUSION: These data indicate that certain genetic factors play a role in the etiology of chronic sinusitis.

Adolescent↗
PubMed1999

Effect of biochemical components on rheologic properties of nasal mucus in chronic sinusitis.

The effect of biochemical components on the viscoelasticity of nasal mucus from 24 patients with chronic sinusitis (CS) was investigated by multiple stepwise regression analysis. The dynamic viscosity (eta') and the elastic modulus (G') of nasal mucus were determined with an oscillating sphere magnetic rheometer at oscillatory frequencies of 1 and 10 Hz. The eta' and G' values of mucus determined at 1 Hz were 1.6 +/- 1.5 Pa/s and 31.8 +/- 31.0 Pa, respectively, and these values were much higher than optimal viscoelasticity for mucociliary transport. The concentrations of fucose, N-acetyl neuraminic acid, albumin, IgG, secretory-IgA, and lysozyme were measured in the same mucus samples. The multiple regression analysis showed that the concentration of fucose, a marker of mucous glycoproteins, was the most important determinant of eta' and G'. The analysis also revealed that the level of IgG was the next important determinant. The coefficients of multiple determination for fucose and IgG were 0.732 and 0.733 when the response variables were eta' and G', respectively. The results indicate that locally produced mucous glycoproteins may largely contribute to the high viscoelasticity of nasal mucus in CS.

Adolescent↗
PubMed1999

Immunohistochemical distribution of extracellular matrix components and keratin in experimentally induced otitis media.

The distribution of collagen types I, III, and IV and of laminin, fibronectin, and keratin was studied in otitis media experimentally induced by Streptococcus pneumoniae in the chinchilla. The expression of interstitial collagen types I and III and of fibronectin was increased in the subepithelial space that was thickened by inflammation in the acute period of infection. The expression of collagen type IV in the subepithelial space could be seen in the early period. The epithelial cells in the middle ear changed from flat cuboidal to pseudostratified columnar in pneumococcus-inoculated ears, and the number of keratin-positive epithelial cells in the middle ear increased remarkably after infection. These results indicate that changes in epithelial cell differentiation effected by the extracellular matrix correlate with changes in expression of keratin. It is proposed that the extracellular matrix may contribute to tissue repair in the middle ear after bacterial infection by interfering with cell proliferation of epithelial cells and fibroblasts.

Animals↗
PubMed1999

Effects of Sho-seiryu-to on experimental allergic rhinitis in guinea pigs.

The effects of Sho-seiryu-to, an antiallergic Kampo medicine, on experimental allergic rhinitis were investigated in actively sensitized guinea pigs. The number of sneezes and scratches by the animals after a topical antigen challenge was significantly inhibited by pretreatment with Sho-seiryu-to (1000 mg/kg per os p.o.). The antigen-induced eosinophil infiltration in the nasal mucosa was significantly inhibited by Sho-seiryu-to (1000 mg/kg p.o.). Sho-seiryu-to (100 mg/kg p.o.) also reduced the increase in dye leakage to the nasal cavity induced by the antigen challenge and the antigen-induced decrease in volume of the nasal cavity was inhibited. Moreover, Sho-seiryu-to (1000 mg/kg p.o.) suppressed the volume change in the nasal cavity induced by leukotriene D4. These results demonstrate that Sho-seiryu-to inhibits experimental allergic rhinitis in guinea pigs, confirming that the agent may be beneficial for the treatment of allergic rhinitis.

Animals↗
PubMed1999

Collagen-phagocytosing ability of periodontal osteoblasts at the bone surface.

The collagen-phagocytosing activity of osteoblasts at the alveolar bone-ligament interface of rat mandibular first molars was investigated both histologically and histochemically. Alveolar bones of male Wistar rats (6 months old) were used in this study. Collagen-containing phagosomes appeared in cuboidal osteoblasts aligned on the bone surface. The 5.7% of the osteoblasts exhibiting alkaline phosphatase activity revealed collagen-containing phagosomes, and the collagen fibrils within the phagosomes were at various stages of degradation. In addition, acid phosphatase activity and the immunocytochemical distribution of cathepsin B were found in these collagen-containing phagosomes at similar locations. The presence of both enzymes in the phagosomes suggests that an intracellular degradation of collagen occurs. Therefore, in addition to the osteoblastic functions of synthesizing and secreting bone matrices, osteoblasts are also capable of phagocytosis and the intracellular disintegration of collagen. Our findings suggest that osteoblasts at the alveolar bone-periodontal ligament interface have a collagen-phagocytosing ability and play an important role in the physiological remodeling and metabolic breakdown of collagen fibrils of periodontal ligament without osteoclastic bone remodeling.

Animals↗
PubMed1998

Whole-body cortisol concentrations and ontogeny of aggressive behavior in yellowtail (Seriola quinqueradiata Temminck & Schlegel; Carangidae).

Ontogenetic changes in whole-body immunoreactive cortisol concentrations (IRC) and aggressive behavior were examined in yellowtail Seriola quinqueradiata (Temminck & Schlegel; Carangidae). Baseline IRC significantly increased during the transition from larval to juvenile stage and was correlated with the onset of aggressive behavior. Handled fish (13.1 +/- 2.6 ng/g tissue) showed an IRC level about three times higher than unhandled fish (4.7 +/- 1.4 ng/g tissue), indicating that whole-body immunoreactive cortisol level may be an indicator of stress in juvenile yellowtails. Behaviorally subordinate fish (8.6 +/- 1.6 ng/g tissue, n = 4) showed IRC levels significantly higher than dominant fish (0.6 +/- 0.3 ng/g tissue, n = 4). Whole-body immunoreactive cortisol levels may thus reflect stress and social status in juvenile yellowtails, and the inverse relationship between social rank and IRC may result from agonistic interactions.

Aggression↗
PubMed1998

A comparative study of the ciliary area of the maxillary sinus mucosa and computed tomographic images.

The ciliary area of the maxillary sinus mucosa and coronal sinus computed tomographic (CT) scans were studied in 36 maxillary sinuses of 28 patients with chronic sinusitis. Tissue specimens allowed ciliary surfaces to be observed under scanning electron microscopy, allowing surfaces to be expressed in terms of ciliary area (CA) as the percentage of mucosal surface occupied by cilia. The opacity produced by mucosal swelling and secretion in the maxillary sinus on CT was assessed by two methods: Min's and modified van der Veken's methods. Both techniques indicated an inverse correlation between opacity of the maxillary sinus and CA. Our findings suggest that the opacity of maxillary sinus on CT could be a significant parameter for predicting the surface conditions of ciliated maxillary mucosa prior to sinus surgery.

Adult↗
PubMed1998

Confocal laser scanning microscopic study [corrected] of tartrate-resistant acid phosphatase-positive cells in the dental follicle during early morphogenesis of mouse embryonic molar teeth.

Tartrate-resistant acid phosphatase (TRAPase)-positive cells were examined during the early morphogenesis of mouse mandibular first molar teeth, using a simultaneous azo dye-coupling technique and confocal laser scanning microscopy (CLSM). CLSM of paraffin-embedded sections revealed that cells exhibiting TRAPase fluorescence appeared along the marginal region of the condensed dental mesenchyme, not yet the dental follicle, at embryonic day 12 (E12). The follicle was recognized histologically as a population of fibroblastic cells in tooth organs at E14, and TRAPase-positive cells were localized among the follicular cells. Light-microscopic observations of microsliced thick sections showed the overall morphology of the TRAPase-positive cells. A few positive cells of E13 tooth organs were oval, and the intense reaction products of TRAPase revealed complex processes on positive cells in E14 tooth organs. Three-dimensional fluorescent images of TRAPase-positive cells using microsliced sections and CLSM showed their unique morphology of long processes with small spine-like projections at E14. Thus, TRAPase-positive cells appeared in the region of the prospective follicle at the bud stage (E12 and 13) before the formation of the follicle proper. In addition, the formation of the follicle and the appearance of TRAPase-positive cells with unique morphology were correlated in their developmental stage (E14). The findings suggest that the TRAPase-positive cells may be involved in the formation of the dental follicle in early tooth morphogenesis.

Acid Phosphatase↗
PubMed1998

Nasal passage patency in patients with allergic rhinitis measured by acoustic rhinometry: nasal responses after allergen and histamine provocation.

We investigated nasal passage patency after allergen and histamine provocation in patients with allergic rhinitis by acoustic rhinometry. In total, 75 outpatients with allergic rhinitis were studied. The threshold of nasal hypersensitivity to histamine was measured by the 10 microliters instillation of serial 10-fold dilution in the ipsilateral nasal cavity. Nasal provocation testing to specific antigen was applied to the anterior part of inferior turbinate in bilateral sides in sitting position. Measurement of nasal patency by acoustic rhinometry was repeated three times in each nasal cavity. The minimal cross-sectional area and total volume of nasal cavity were measured in an individual subject. The minimal cross-sectional area and total volume in the histamine challenged-side significantly decreased on the 10(-2), 10(-1), 10(-0) of end point, and up to 30 min after challenge with the threshold dose, but not in the unchallenged side. This means acoustic reflection technique is sensitive at least 100-fold in comparison with classical method like findings by anterior rhinoscopy and symptom scores. Nasal passage patency after bilateral allergen provocation showed predominant in the unilateral side, suggesting the cross over-reflex effects. It was concluded that acoustic rhinometry is one of the highly quantitative and sensitive method which can observe the change of nasal congestion.

Adolescent↗
PubMed1998

Expression of interferon-gamma, interleukin-4 and interleukin-5 mRNA in the nasal mucosal membrane of rats with allergic rhinitis.

The production of immunoglobulin E (IgE) antibody is largely dependent on the ratio between interleukin-4 (IL-4) (a T helper 2 (Th2)-type cytokine) and interferon-gamma (IFN-gamma) (a T helper 1 (Th1)-type cytokine). Interleukin-5 (IL-5) (also a Th2-type cytokine) is an important eosinophil differentiation factor and also co-stimulates B-cell growth and differentiation. The present study was designed to evaluate and compare the expression of IFN-gamma, IL-4 and IL-5 mRNA in the nasal mucosal membrane of sensitized Brown-Norway (BN) rats. Fourteen BN rats were divided into two groups: non-sensitized (control) and sensitized. The sensitized group was injected with ovalbumin (OA) intraperitoneally on three consecutive days. Twenty-one days later, rats were exposed to 1% OA aerosol. Twenty-four hours after exposure to aerosol, nasal mucosa was extracted from both groups and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed. The densities of the bands of IL-4, IL-5 and IFN-gamma mRNA were expressed as percentages against beta-actin mRNA. Our results showed that the mean values for IL-4 and IL-5 mRNA were increased significantly in sensitized rats compared with control rats. In contrast, the mean value for IFN-gamma mRNA was significantly lower in sensitized rats compared with those of the control group. Our data therefore suggest that sensitization of rat nasal mucous membranes results in the predominant expression of Th2-type cytokines.

Airway Resistance↗
PubMed1998

Effect of allergen-specific immunotherapy on interleukin-4, interleukin-5 and interferon-gamma mRNA expression in the nasal mucosa of rats with allergic rhinitis.

To elucidate the mechanism of immunotherapy, we tested the effect of ovalbumin and ovalbumin-pullulan conjugate immunotherapy on the expression of interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) mRNA in the nasal mucosa of sensitized rats. Forty-five rats were injected with ovalbumin intraperitoneally on three consecutive days and later were exposed to ovalbumin aerosol. The rats were injected intradermally, on six consecutive days, with saline, ovalbumin or ovalbumin-pullulan conjugate. Later, nasal mucosa was obtained and reverse transcription-polymerase chain reaction (RT-PCR) was performed. Nasal responses and specific immunoglobulin E (IgE) were measured. Although the immunotherapy significantly decreased nasal airway resistance, dye leakage and histamine content in nasal irrigation after allergen challenge, no significant difference was found in IL-4 and IL-5 mRNA expression or in specific IgE level among the three groups. We conclude that in this allergic model, the improvement of nasal responses after immunotherapy was the result of a mechanism other than decrease of T-helper 2 (Th2) cytokines.

Airway Resistance↗