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Biomedical subjects

Katsuhiro Hirakawa

Publications and source records attributed to Katsuhiro Hirakawa.

9 recordsLinked to original sources
PubMed2004

Bone-constructing cells from ethmoid bone may have multilineage differentiation potential: preliminary report.

OBJECTIVE: In order to investigate multilineage differentiation in human cultured cells from ethmoid bone, we conducted a morphological study to examine adipogenic and chondrogenic differentiation. MATERIAL AND METHODS: After reaching confluence, cells underwent terminal adipogenic differentiation by treatment with 100 microM indomethacin, 0.5 mM 1-methyl-3-isobutylxanthine, 1 microM dexamethasone (DEX), 10 microg/ml insulin and 0.3% dimethylsulfoxide in a medium supplemented with 10% fetal bovine serum. Chondrogenic differentiation was attempted by centrifuging a pelleted micromass using transforming growth factor-beta3 (TGF-beta3), DEX, ascorbic acid (AA), pyruvate acid, proline, glucose and (ITS)-plus. RESULTS: The cultured cells displayed adipocyte but not chondrogenic lineage under these conditions. Considering the possibility that some differentiation potential may be lost with in vitro culture but maintained using another chondrogenic differentiation medium containing TGF-beta1, it is possible that cultured cells may have multilineage potential, including chondrogenic differentiation ability. CONCLUSIONS: These morphological abilities of human cultured cells may indicate the possibility of the existence of mesenchymal stem cells in sinus bone. If mesenchymal stem cells exist in ethmoid bone, they may play an important role in future research on the regulation mechanisms of human bone tissue.

Adipocytes↗
PubMed2003

Establishment of osteoblast culture from human ethmoidal sinus.

OBJECTIVE: Chronic sinusitis is characterized by persistent chronic inflammation of the sinus system and local expression and release of various cytokines, such as IL-1 beta, IL-4, IL-6, IL-8, TGF-beta and TNF-alpha are deeply involved in the pathogenesis of the disease. We hypothesized that not only the sinus mucosa-containing cells, such as epithelial cells and fibroblasts, but also osteoblasts, of which sinus bone structure consists, may contribute to this inflammatory network. This study evaluates the development and establishment of an osteoblasts culture system derived from human ethmoidal sinus as an initial step toward verifying this hypothesis. METHODS: Ethmoidal sinus bone was obtained from patients at the time of sinus surgery for chronic sinusitis and outgrowth cell sheets were obtained according to the explant-outgrowth cell culture technique. In order to examine the specific characteristics of osteoblasts in the obtained cells, four major features of osteoblasts (collagen type I, osteocalcin synthesis, alkaline phosphatase activity and extracellular matrix mineralization ability) were investigated at the third passage of the culture and productions of TGF-beta 1, which modulate osteoblast proliferation and maturation in an autocrine fashion, in the cultured medium was also investigated in time of culture up to 20 days. RESULTS: The cells obtained in our study clearly show collagen type I synthesis, osteocalcin synthesis, alkaline phosphatase activity and production of visible extracellular matrix mineralization. Production of TGF-beta 1 in the medium did not significantly different in time of culture up to 20 days. CONCLUSION: Our results, the first of their kind, indicate that osteoblast-like cells can be cultured from adult human ethmoidal sinus bones. It suggested that proliferation and maturation of the osteoblast were continuously modulated in an autocrine fashion by producing TGF-beta 1.

Adolescent↗
PubMed2003

Reduced expression of p27 is correlated with progression in precancerous lesions of the larynx.

OBJECTIVES: Factors related to malignant transformation of laryngeal precancerous lesions remain largely unknown, so we investigated the relationship between the expression of p27 and precancerous laryngeal lesion. STUDY DESIGN: In this study we investigated the expressions of p27 and p53 protein in 56 cases with laryngeal precancerous or cancer lesions (20 cases of hyperplasia, 19 of dysplasia, and 17 of squamous cell carcinoma), and went on to evaluate the relationship between immunoreactivity of each of them and the histological findings. We also evaluated the correlation between immunoreactivity and proliferative activity with the aid of Ki-67 nuclear antigen staining. METHODS: A retrospective study was performed in 56 cases (20 with epithelial hyperplasia, 19 with epithelial dysplasia and 17 with laryngeal cancer). Immunohistochemistry was performed to investigate expression of p27, p53 protein and Ki-67 nuclear antigen staining, using the avidian-biotin-peroxidase complex technique. RESULTS: p27 immunostaining was observed in 12 out of 20 cases of hyperplasia (60%), six out of 19 cases of dysplasia (31%), and 2/17 (12%) of carcinoma. We found significant association between p27 immunostaining and the histological findings. On the other hand, p53 immunostaining was observed in 6/20 (30%) of hyperplasia, 3/19 (16%) of dysplasia, and 7/17 (41%) of carcinoma. No significant association was found between p53 and the histological findings. CONCLUSIONS: Our results revealed that immunohistochemical assessment of p27 in bioptic samples of laryngeal precancerous lesions might be useful in selective patients who should undergo a more specific follow-up evaluation.

Adult↗
PubMed2003

Leukotriene receptor antagonist pranlukast suppresses eosinophil infiltration and cytokine production in human nasal mucosa of perennial allergic rhinitis.

The purpose of this study was to investigate the influence of pranlukast on eosinophilic inflammation and cytokine production in human nasal mucosa. Twelve patients were treated with pranlukast, and samples were obtained from the nasal mucosa of the inferior turbinate. With respect to cell infiltration, a significant decrease was observed in the percentage of inflammatory cells (secreted eosinophil cationic protein [EG2] and neutrophil elastase) after treatment. The levels of cytokines and chemical mediators (interleukin [IL]-4, IL-5, RANTES [regulated on activation, normal T cell expressed and secreted], cysteinyl leukotrienes, IL-1beta, tumor necrosis factor-alpha, and IL-8) assessed by enzyme-linked immunosorbent assay and enzyme immunoassay were significantly decreased. These results indicate that pranlukast decreased the levels of a majority of the cytokines in nasal mucosa, leading to improvement in subjective nasal symptoms. Furthermore, these results support the hypothesis that pranlukast exerts its therapeutic action primarily by blocking the leukotriene receptors on eosinophils.

Adult↗
PubMed2003

Human osteoclast maturation from bone marrow cells co-cultured with osteoblast from ethmoid sinus.

In chronic sinusitis, although the pathogenesis in the sinus mucosa has been widely investigated, the pathogenesis in the underlying bone remains poorly understood. As a first step in investigating the pathogenesis in sinus bone, sinus-bone models should be constructed by co-culturing of osteoblasts and osteoclasts in a sinus. However, human osteoclast cell lines derived from a sinus have not been established. Based on previous methods of another osteoclast culture, we hypothesized that human osteoclasts in sinuses could be established in vitro by co-culture with human osteoblasts in the sinus. The aim of this study was to differentiate human bone marrow cells into osteoclasts in a sinus, which is identified by the formation of absorption lacuna and positive cytochemical staining for tartrate-resistant acid phosphatase (TRAP). Differentiation was induced in the co-culture system by treatment with medium containing 1.25.(OH)2D3, G-CSF and dexamethasone. Thirty days after culturing, human bone marrow cells were differentiated to a hypertrophic state, as evidenced by their sizes and the demonstration of osteoclast-specific abilities. Our results indicate that sinus-osteoclasts can be cultured from human bone marrow cells, and that osteoclasts in a sinus may be a useful model for investigating sinus-bone remodeling, especially in terms of bone resorption, in the sinus system.

Acid Phosphatase↗
PubMed2003

Expression and localization of nuclear factor-kappa B subunits in cultured human paranasal sinus mucosal cells.

The purpose of this study was to compare the expression of cytokines and nuclear factor-kappa B (NF-kappa B) subunits in cultured sinus mucosal cells by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) in chronic sinusitis patients with allergic rhinitis (abbreviated as AR patients) versus patients without AR (abbreviated as non-AR patients). The localization of p50 in cultured sinus mucosal cells was also observed by immunocytochemistry. The expression of messenger RNAs (mRNA) encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6, IL-8, p50 and p65 subunits, and inhibitory kappa B-alpha (I kappa B-alpha) were analyzed by RT-PCR. The proportion of active NF-kappa B-positive cells in the epithelial layer was analyzed using a laser-scanning confocal microscope image system. The levels of GM-CSF, IL-6, IL-8, and p50 mRNAs in AR patients were significantly higher than those in non-AR patients (p < 0.01, p < 0.01, p < 0.01, and p < 0.001, respectively). Immunocytochemical reaction for p50 in sinus mucosal cells in AR patients showed more intense nuclear staining compared to non-AR patients. These findings could support the hypothesis that the increase of cytokines from sinus mucosal cells in AR patients was associated with augmented NF-kappa B mRNA expression, resulting in the modification of the cytokine network.

Case-Control Studies↗
PubMed2002

Nuclear factor-kappa B activation in the nasal polyp epithelium: relationship to local cytokine gene expression.

OBJECTIVES: A panel of cytokines has been found to be important for eosinophil accumulation and activation in nasal polyps. The aims of this study were to ascertain whether the activation of nuclear factor-kappa B (NF-kappaB) occurred in the polyp epithelium, and to examine the relationship between the degree of activation and local cytokine gene expression. STUDY DESIGN/METHODS: Nasal polyp specimens were obtained from 26 untreated patients. The proportion of nuclear translocation of the NF-kappaB p50 subunit in the polyp epithelium was quantitatively analyzed by a combination of fluorescent immunohistochemistry and a laser scanning confocal microscope image system. The levels of GM-CSF, IL-5, IL-8, IL-16, and eotaxin mRNA expression in the same speci-mens were measured using reverse transcription-polymerase chain reaction. RESULTS: Both cytoplasmic and nuclear localization of the p50 subunit was observed mainly in the epithelial layer in all specimens. The percentages of epithelial cells with nuclear translocation ranged from 4.5% to 40.5% (median, 18%). Significant correlations were observed between the degree of epithelial NF-kappaB activation and the levels of IL-8, IL-16, and eotaxin mRNA expression (r = 0.468, 0.47, and 0.739, respectively). CONCLUSION: The activation of NF-kappaB in the nasal polyp epithelium is responsible for the recruitment of inflammatory cells, particularly eosinophils, through the initiation of the transcriptional pathway of the related cytokines. The increased NF-kappaB activity in the polyp epithelium may reflect hypersensitivity to unknown stimuli.

Chronic Disease↗
PubMedDate not supplied

Suppression of the Th2 pathway by suplatast tosilate in patients with perennial nasal allergies.

BACKGROUND: Suplatast tosilate (IPD-1151T), a selective Th2 cytokine inhibitor that suppresses the production of interleukin (IL)-4 and IL-5 in vitro or in animal models has been proved clinically effective for allergic rhinitis (AR). The aim of this study was to investigate changes in the Th2 pathway in human nasal mucosa after medication with IPD-1151T. Twelve patients were treated with IPD-1151T. METHODS: Twelve healthy volunteers served as normal controls. The following parameters were evaluated: (i) subjective nasal clinical symptoms, (ii) percentages of inflammatory cells (EG2, CD4, and CD8) by immunocytological staining, and (iii) levels of cytokines (IL-4, IL-5, IL-13, regulated on activation, normal T-cell expressed, and secreted [RANTES], and interferon [IFN] gamma) by enzyme-linked immunosorbent assay. RESULTS: Nasal symptom scores significantly decreased after treatment. With respect to cell infiltration, a significant decrease was observed in the percentage of inflammatory cells (EG2 and CD4) and CD4/CD8 ratio. The levels of cytokines (IL-4, IL-5, IL-13, and IFN-gamma) and the IL-5/IFN-gamma ratio were significantly decreased, and the IL-4/IFN-gamma ratio became not significantly different from that in normal subjects. In contrast, RANTES did not change significantly. The percentage of reduction in IL-5 correlated with that in eosinophil infiltration, whereas that in RANTES did not. CONCLUSION: These results suggest that IPD-1151T can reduce the Th2 pathway.

Adult↗