Koji Yajin

Increased Expression of Inducible Nitric Oxide Synthase in Nasal Epithelial Cells in Patients With Allergic Rhinitis

Objectives: Although ciliated epithelial cells of human nose and paranasal sinuses have recently been reported to be the major source of locally detected nitric oxide (NO), changes to the NO production by these cells and their functional roles remain uncertain in relation to allergic rhinitis. The objective of this study is to investigate differences in the ability of induction of nitric oxide synthase (NOS) isoforms by nasal epithelial cells.

Increased nitric oxide production in nasal epithelial cells from allergic patients – RT‐PCR analysis and direct imaging by a fluorescence indicator: DAF‐2 DA

Background Nitric oxide (NO) is believed to participate in the regulation of airway clearance and non‐specific cellular immunity. Recent studies have suggested that airway epithelial cells of allergic and non‐allergic individuals may differ in their ability to produce this molecule.

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‐κB) occurred in the polyp epithelium, and to examine the relationship between the degree of activation and local cytokine gene expression.

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-1β, tumor necrosis factor–α, 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.

Effect of 9-cis-retinoic acid on oral squamous cell carcinoma cell lines

Retinoic acid (RA) has been shown to be effective in suppressing premalignant lesions and preventing second primary malignancies in patients cured of squamous cell carcinoma of the head and neck. However, the precise mechanisms of these effects are still uncertain. In the present study, we examined the effect of 9-cis-RA on the growth of six oral cancer cell lines (HSC-2, HSC-3, HSC-4, Ca9-22, Ho-1-N-1 and Ho-1-u-1). In addition, the relationship among growth and differentiation of tumor cells, RA responsiveness and the expression of nuclear retinoic acid receptors were also investigated. Among the six cell lines examined, five (HSC-2, HSC-3, HSC-4, Ca9-22 and Ho-1-u-1) displayed growth inhibition after treatment with 1x10(-6) M 9-cis-RA, while Ho-1-N-1 cells were resistant to 9-cis-RA. The expression level of RARbeta in 9-cis-RA resistant Ho-1-N-1 cells was very low in comparison with the sensitive cell lines. On the other hand, all of the six the cell lines expressed RARalpha, RARgamma, and RXRalpha at various levels. 9-cis-RA induced accumulation of cell population in G1 phase in HSC-3 cells on the 6th day of the treatment, followed by a marked reduction in the levels of hyperphosphorylated pRB, whereas p53 level was not altered. Interestingly, 9-cis-RA induced transiently the expression of p21(Waf1/Cip1), p27(Kip1), p300, CBP, BAX, Bak and bcl-2 proteins, respectively. This effect was associated with reduction of cyclin D1, cdk4 and CDK-activating kinase (cyclin H and cdk7) protein in HSC-3 cells. These results suggest that the growth inhibitory effect of 9-cis-RA on oral squamous cell carcinoma may depend on the expression levels of RARs, especially RARbeta proteins and RXRalpha proteins, and that 9-cis-RA may provide a powerful therapeutic agent for head and neck cancers.

Laser surgery of the inferior turbinate for allergic rhinitis with seasonal exacerbation: an acoustic rhinometry study.

Laser surgery has been used to successfully treat patients with perennial allergic rhinitis. We examined whether the numbers and types of sensitized allergens influence the effects of surgery. Two different groups (those allergic to house dust mites only, and those allergic to house dust mites and Japanese cedar pollen) prospectively underwent the same course of laser turbinectomy during the pollen dispersion season. The symptom scores for nasal obstruction significantly decreased in both groups, but the improvement of sneezing and rhinorrhea was less pronounced in the pollen group. We used acoustic rhinometry to measure postoperative changes in the nasal dimensions. Four months after treatment, the minimum cross-sectional area and nasal cavity volume had increased, respectively, by 61.7% and 30.7% in the house dust group, and by 30.7% and 16.2% in the pollen group. We conclude that laser surgery can be successfully applied to patients whose allergies show seasonal exacerbation by airborne pollen.

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] γ) 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-γ) and the IL-5/IFN-γ ratio were significantly decreased, and the IL-4/IFN-γ 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.

Formation and Fate of Giant Otoconia of the Guinea Pig following Streptomycin Intoxication

Formation and fate of abnormal (giant) otoconia of the guinea pig following streptomycin intoxication were investigated using scanning electron microscopy. The giant otoconia formed as multifaceted morphology in their early developmental period. They grew up the the transitional type and finally to the cylindrical type. It has been suggested that the giant otoconia found following streptomycin intoxication may be formed mainly by dissolution of normal otoconia due to the loss of environmental calcium, followed by recrystallization as giant crystals. These phenomena seemed to be closely related to the otoconial dynamics which may regulate calcium ion homeostasis of the endolymph.

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.

Enhancement of GABA-mediated Inhibition of Rat Medial Vestibular Nucleus Neurons by the Neurosteroid 20-Hydroxyecdysone

In vivo electrophysiological and patch-clamp studies were performed to determine whether 20-hydroxyecdysone (20-HE), a neurosteroid, influenced neuronal activities of the medial vestibular nucleus (MVN) using chloral hydrate-anesthetized rats and dissociated MVN neurons, respectively. Single neuronal activities of MVN were extracellularly recorded with a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette. Each micropipette was filled with 20-HE, glutamate, bicuculline or 2 M NaCl. These chemicals were applied microiontophoretically to the immediate vicinity of the target neurons. Microiontophoretically applied 20-HE (20-80 nA) dose-dependently decreased rotation-induced firings of both type I and II neurons, which were identified according to their responses to horizontal sinusoidal rotations. Microiontophoretically applied bicuculline, a GABAA receptor antagonist, inhibited 20-HE-induced decreases in neuronal firing of MVN. These findings suggest that 20-HE potentiates the action of GABA, probably by acting directly on the GABAA receptor of MVN neurons. In addition, microiontophoretically applied 20-HE decreased firings induced by glutamate in both type I and II neurons. This decrease by 20-HE was also antagonized with bicuculline. Furthermore, the effects of 20-HE on GABA-induced currents in acutely dissociated MVN neurons were investigated using the whole-cell patch-clamp technique. Under voltage-clamp conditions, GABA (10 microM)-induced currents were potentiated in the presence of 20-HE (100 microM). These findings suggest that 20-HE inhibits MVN neurons by acting on the modulatory site on GABA receptor-ion channel complexes to potentiate GABA inhibition.