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Yuichi Kurono

Publications and source records attributed to Yuichi Kurono.

18 recordsLinked to original sources
PubMed2005

TNF-alpha and endotoxin increase hypoxia-induced VEGF production by cultured human nasal fibroblasts in synergistic fashion.

OBJECTIVE: Vascular endothelial growth factor (VEGF) promotes angiogenesis and is associated with the invasion and metastasis of malignant tumors. It enhances vascular permeability and is expressed in inflammatory nasal as well as middle-ear mucosa. As the mechanism of VEGF induction during chronic inflammation, such as chronic paranasal sinusitis (CPS) remains to be clarified, we studied the factors regulating the production of VEGF in cultured human nasal fibroblasts and discussed the role of VEGF in the pathogenesis of CPS. METHODS: We used ELISA to quantify VEGF levels in paranasal sinus effusions, nasal secretions, and serum from patients with CPS. In addition, we cultured human nasal fibroblasts isolated from nasal polyps of CPS patients and studied the effects of hypoxia, TNF-alpha, and endotoxin on their production of VEGF using ELISA and PCR. RESULTS: The VEGF concentration was significantly higher in paranasal sinus effusions than in nasal secretions and serum. Nasal fibroblasts produced high levels of VEGF, when cultured under hypoxic condition and this production was remarkably enhanced in the presence of TNF-alpha or endotoxin. CONCLUSION: VEGF is locally produced in paranasal sinuses as well as nasal mucosa and its production is increased in patients with CPS. Hypoxia is associated with the production of VEGF by nasal fibroblasts and TNF-alpha and endotoxin may act synergistically to enhance VEGF production in paranasal sinuses under hypoxic condition.

Analysis of Variance↗
PubMed2005

Taste disorders: a survey of the examination methods and treatments used in Japan.

CONCLUSIONS: In Japan, the number of patients seeking treatment for taste disorders from otolaryngologists is approximately 240 000/year, and this number has almost doubled in the last 13 years. Taste examinations are routinely conducted in almost all university hospitals; testing is not as common in private clinics. Administration of zinc is the main treatment for taste disorders in Japan. OBJECTIVES: To investigate the number of patients who visited otolaryngologists for treatment of taste disorders between 2000 and 2002. In addition to determining changes in the number of patients that had occurred in the 13 years since the last study in 1990, the survey also sought to find out what types of taste examination were used to diagnose taste disorders in Japan and what therapies were used to treat them. MATERIAL AND METHODS: A questionnaire was mailed to 1559 members of the Japan Society of Stomato-pharyngology. RESULTS: The average number of patients with taste disorders who visited otolaryngological clinics between 2000 and 2002 was 244 858/year. This number is 1.77-fold greater than the number of patients reported by the last study in 1990 (138 575). Electrogustometry was used in 99% of university hospitals and in 20% of private clinics. The filter-paper disk method was also used in 57% of university hospitals and in 27% of private clinics. The main treatment was zinc administration. Most doctors (70%) prescribed polaprezinc, a zinc-containing drug that is used to treat peptic ulcers. Of these doctors, 78% stated that it effectively treated taste disorders and 11% that it did not.

Carnosine↗
PubMed2005

Inhibition of vascular endothelial growth factor by macrolides in cultured fibroblasts from nasal polyps.

OBJECTIVE: In order to study a new mechanism of efficacy of 14-membered ring macrolides in treating chronic rhinosinusitis, inhibitory effects of macrolides on vascular endothelial growth factor production were examined in vitro. METHODS: Vascular endothelisal growth factor production in cultured fibloblasts from human nasal polyps obtained from surgery for chronic paranasal sinusitis stimulated by hypoxia or tumor necrosis factor-alpha was assessed under the administration of Clarithromycin or Roxisthromycin by enzyme linked immunosorbent assay and reverse transcriptase polymerase chain-reaction. RESULTS: Dose-dependent inhibitory effects on vascular endothelisal growth factor production stimulated by hypoxia or tumor necrosis factor-alpha were noted in the groups treated with Clarithromycin and Roxisthromycin, including inhibition of vascular endothelisal growth factor mRNA levels. CONCLUSION: While, to date, several evidences have indicated that the mechanisms by which 14-membered ring macrolides reduce inflammation are not simply bactericidal, these results suggest another new mechanism of efficacy of macrolides in treating chronic rhinosinusitis.

Adult↗
PubMed2004

Extravascular papillary endothelial hyperplasia arising from parapharyngeal space.

A 66-year-old man visited our clinic suffering from swelling of right pharyngeal space. He was not aware of other symptoms. The contrast CT showed patchy enhancement with calcification. The enhanced MRI revealed a non-homogeneous signal pattern and patchy central enhancement. During surgery, egg-shaped hard elastic tumor was observed in parapharyngeal space without any sign indicating an invasion into surrounding nerves or feeding vessels. Then the tumor was removed without significant hemorrhage or damage to the cranial nerve. Histological examination of the tumor revealed a nodular lesion with blood clot and hematoma encapsulated with fibrous tissue having vascular spaces of irregular shape and size. From those findings, the tumor was diagnosed as papillary endothelial hyperplasia (PEH). However, since the location of the tumor differed from that of PEH commonly observed in the intravascular space, the tumor was classified as extravascular PEH.

Aged↗
PubMed2004

Cytokine expression in experimental chronic otitis media with effusion in mice.

OBJECTIVES: Although otitis media with effusion (OME) is still a common disease in children and adults, the pathogenesis is not yet fully understood. We studied the effects of intratympanic injection with endotoxin purified from nontypeable Haemophilus influenzae on the characteristics of middle ear effusion (MEE). METHODS: Murine model of OME was developed by eustachian tube (ET) blockage followed by intratympanic inoculation with endotoxin (endotoxin group) or saline (control group). The mice were decapitated and histological changes and the production of inflammatory cytokines in MEEs were examined 3 days, 2 weeks, and 2 months after injection. RESULTS: All mice showed OME until 2 months after ET blockage. Most MEEs in the control group were serous, and mucoid or pultaceous MEEs were found only in the endotoxin group. Subepithelial space of middle ear mucosa was severely thickened with the infiltration of a large number of mononuclear cells in the endotoxin group. The levels of tumor necrosis factor-alpha (TNF-alpha) in MEEs were significantly higher in the endotoxin group than in the control group at all time points. Further, in situ hybridization showed that TNF-alpha messenger RNA was expressed not only by leukocytes and macrophages in MEEs but mononuclear cells present in the subepithelial space of middle ear mucosa. CONCLUSIONS: These results indicate that ET blockage is essential for the induction of serous MEE and additional administration of endotoxin is associated with the production of mucoid MEE accompanied by histological changes with inflammatory cell infiltration and cytokine production in the tympanic cavity.

Animals↗
PubMed2003

Hypoxia in paranasal sinuses of patients with chronic sinusitis with or without the complication of nasal allergy.

OBJECTIVE: In order to elucidate the pathogenesis of the radiologic opacity of the sinuses frequently observed in patients with allergic rhinitis, the mechanisms underlying their sinus mucosal swelling were studied clinically. MATERIAL AND METHODS: We confirmed the presence of hypoxia in inflamed sinuses and obstruction of the sinus ostium in operated patients with chronic sinusitis by digitally monitoring the oxygen tension. The possibility of radiologic sinus shadow was also investigated after transient obstruction of the natural ostium. RESULTS: The oxygen tension was significantly lower in inflamed than non-inflamed sinuses (p < 0.01), irrespective of the presence or absence of allergic rhinitis. In 54.5% of patients without sinusitis, transient obstruction of the middle meatus by gauze packing resulted in the appearance of a pathologic sinus shadow on radiograms obtained after septoplasty and turbinotomy. In both allergic and non-allergic rhinitis, thick opacity was the most frequently encountered pattern (p < 0.01). CONCLUSION: Our study revealed that in the absence of a primary allergic reaction in the sinus mucosa, blocking of the middle meatus and ostium by allergic swelling of the nasal mucosa may induce hypoxia and secondary mucosal swelling in the sinuses.

Adult↗
PubMed2003

The role of nuclear factor-kappa B in interleukin-8 expression by human adenoidal fibroblasts.

OBJECTIVES/HYPOTHESIS: The production of cytokines by adenoids is known to be associated with inflammation of nasopharynx and the pathogenesis of otitis media with effusion. However, the role of adenoids in producing inflammatory cytokines such as interleukin-8 (IL-8) is not yet clear. In the present study, expression of IL-8 in adenoidal fibroblasts was investigated at the level of transcription factors. Further, the effects of clarithromycin, a 14-member ring macrolide, on IL-8 gene expression and nuclear factor-kappa B (NF-kappa B) activation in adenoidal fibroblasts were evaluated. STUDY DESIGN: In vitro study for the production of inflammatory cytokine from human adenoidal fibroblasts. METHODS: Adenoidal fibroblasts were incubated with nontypeable Haemophilus influenzae endotoxin or interleukin-1 beta. Then the expression of IL-8 and the influence of NF-kappa B inhibitor and clarithromycin were evaluated. Interleukin-8 protein production was assessed by ELISA, and IL-8 messenger RNA production was measured by Northern blot analysis and reverse transcriptase-polymerase chain reaction. Activation of NF-kappa B and inhibition of its activation were determined by electrophoretic mobility shift assay. RESULTS: The expression of both IL-8 protein and messenger RNA in adenoidal fibroblasts was enhanced by Haemophilus influenzae endotoxin and interleukin-1 beta and was positively correlated with increases in NF-kappa B activity. Treatment of cells with the NF-kappa B inhibitor N-tosyl-(L)-phenylalanine chloromethyl ketone, as well as with clarithromycin, reduced expression of IL-8 and NF-kappa B activity in a dose-dependent manner. CONCLUSIONS: Results suggest that adenoidal fibroblasts produce IL-8 in response to endotoxin through NF-kappa B activation. The inhibitory effects of clarithromycin on NF-kappa B activation and IL-8 production in adenoidal fibroblasts might explain, in part, the mechanism of this drug in improving otitis media with effusion.

Adenoids↗
PubMed2003

[A questionnaire survey on the theory of postoperative infection prophylaxis in otorhinolaryngology].

A questionnaire survey on postoperative infection prophylaxis was conducted to achieve the consensus on the perioperative antimicrobial use among otolaryngologists in Japan during the period of time from April to July 2000. Fifty-two out of 84 otolaryngologists replied, and the following consensus was obtained. An antimicrobial prophylaxis (AMP) agent should be chosen based on their efficacy against the pathogens expected to be contaminants, such as Staphylococcus spp., Pseudomonas aeruginosa and Bacteroides fragilis group; Use an AMP agent that achieves a bactericidal concentrations in both the serum and operating site. Use an AMP agent that has little unfavourable side effects. Newer agents should be considered as therapeutics for postoperative infections. Therapeutic antimicrobial agents having no cross-resistance to the AMP agents should be used, if postoperative infection is suspected or developed. The most commonly used agent for clean operations is cefazolin (CEZ), followed by cefotiam (CTM) and piperacillin (PIPC), in this order. For clean-contaminated operations, the most commonly used agent is CEZ, followed by flomoxef (FMOX) and CTM.

Antibiotic Prophylaxis↗
PubMed2002

Application of cyberknife for the treatment of juvenile nasopharyngeal angiofibroma: a case report.

Juvenile nasopharyngeal angiofibroma (JNA) tumors can be locally destructive when they spread submucosally. The purpose of this study was to present an image-guided, robotic radiotherapy (Cyberknife) to successfully treat a 12-year-old boy with Juvenile nasopharyngeal angiofibroma (JNA). He complained of progressive right nasal obstruction, intermittent epistaxis. Computed tomography (CT), and magnetic resonance imaging (MRI) revealed the presence of a tumor in the right nasal cavity and nasopharynx with significant hypervascularization from the right maxillary artery. Pathological findings confirmed the diagnosis of JNA. Surgical treatment was recommended but refused by religious reasons. We initially treated the patient with external-beam radiation therapy (total treatments, 12; total dose, 2400 cGy), which, after 7 months, failed to reduce the size of the tumor or relieve the patient's symptoms. We subsequently treated the patient with Cyberknife therapy (total treatments, 3; total dose, 4512 cGy) and observed almost complete disappearance of the tumor after 7 months. After 2 years of observation, there has been no tumor recurrence. Cyberknife therapy is compared with other therapeutic options for JNA, and its benefits are discussed in the context of the findings in the literature.

Angiofibroma↗
PubMed2002

Initiation of NALT organogenesis is independent of the IL-7R, LTbetaR, and NIK signaling pathways but requires the Id2 gene and CD3(-)CD4(+)CD45(+) cells.

Initiation of nasopharyngeal-associated lymphoid tissue (NALT) development is independent of the programmed cytokine cascade necessary for the formation of Peyer's patches (PP) and peripheral lymph nodes (PLN), a cytokine cascade which consists of IL-7R, LTalpha1beta2/LTbetaR, and NIK. However, the subsequent organization of NALT seems to be controlled by these cytokine signaling cascades since the maturation of NALT structure is generally incomplete in those cytokine cascade-deficient mice. NALT as well as PP and PLN are completely absent in Id2(-/-) mice. NALT organogenesis is initiated following the adoptive transfer of CD3(-)CD4(+)CD45(+) cells into Id2(-/-) mice, constituting direct evidence that CD3(-)CD4(+)CD45(+) inducer cells can provide an IL-7R-, LTalpha1beta2/LTbetaR-, and NIK-independent tissue organogenesis pathway for secondary lymphoid tissue development.

Adoptive Transfer↗
PubMed2002

[Application of prosthetic replacement for bilateral maxillectomy defect].

A 59-year-old woman with large hard palate cancer underwent surgical resection. We constructed a maxillary prosthesis to be connected to the patient's mandibular denture. Bilateral maxillectomy resulted in total loss of the hard palate and bilateral alveolar and partial loss of the soft palate. A obturator prosthesis was prepared beforehand to fit the surgical cavity. The patient recovered functional speech and swallowing at a relatively early stage, achieving satisfactory cosmetic results.

Carcinoma, Squamous Cell↗