Pranlukast (PLK) is a cysteinyl leukotriene receptor 1 antagonist approved for the treatment of bronchial asthma and allergic rhinitis in Japan. We previously reported that PLK dry syrup (DS) improved the total nasal symptom score, as well as sneezing, nasal discharge, and nasal obstruction scores over placebo. We investigated the efficacy of PLK DS with a noninvasive method in 10- to 15-year-old children with Japanese cedar (JC) pollinosis challenged with pollen allergen using an artificial exposure chamber (OHIO Chamber). Levels of eosinophil cationic protein (ECP) in nasal secretions, nasal obstruction score, and the relationship with nasal obstruction scores were analyzed. The estimated difference of means in ECP levels (PLK DS--placebo) was -22.9 micrograms (95% CI, -45.2 to -0.5), suggesting PLK DS reduced ECP significantly when compared with placebo (p = 0.0454). The difference in the least square means for nasal obstruction between the PLK DS and placebo was -0.25 (95% CI, -0.36 to -0.14) with a value of p < 0.0001. In addition, a statistically significant, although weak, positive correlation between the nasal obstruction score and nasal ECP levels was observed with placebo treatment (correlation coefficient = 0.2394; p = 0.0428). Moreover, the inhibition rate of nasal ECP with PLK DS relative to placebo was statistically significant, although weak, positively correlated with the inhibition rate of nasal obstruction (correlation coefficient = 0.3373; p = 0.0219). PLK DS significantly decreases nasal ECP levels and nasal obstruction score compared with placebo in children with JC pollinosis challenged with pollen allergen. Suppression of mucosal eosinophilic inflammation is one of the pathways by which PLK DS improves pollinosis-induced nasal obstruction.

The development of the inner ear is an orchestrated process of morphogenesis with spatiotemporally controlled generations of individual cell types. Recent studies have revealed that the Sox gene family, a family of evolutionarily conserved HMG-type transcriptional factors, is differentially expressed in each cell type of the mammalian inner ear and plays critical roles in cell-fate determination during development. In this study, we examined the expression pattern of Sox21 in the developing and adult murine cochlea. Sox21 was expressed throughout the sensory epithelium in the early otocyst stage but became restricted to supporting cells during adulthood. Interestingly, the expression in adults was restricted to the inner phalangeal, inner border, and Deiters' cells: all of these cells are in direct contact with hair cells. Evaluations of the auditory brainstem-response revealed that Sox21(-/-) mice suffered mild hearing impairments, with an increase in hair cells that miss their appropriate planar cell polarity. Taken together with the previously reported critical roles of SoxB1 families in the morphogenesis of inner ear sensory and neuronal cells, our results suggest that Sox21, a counteracting partner of the SoxB1 family, controls fine-tuned cell fate decisions. Also, the characteristic expression pattern may be useful for labelling a particular subset of supporting cells.

Pranlukast (PLK) is a leukotriene receptor antagonist (LTRA) that has been approved for treatment of asthma in patients of all ages and allergic rhinitis (AR) in adults but not for AR in children in Japan. This randomized, double-blind, placebo-controlled, crossover study used an artificial exposure chamber (OHIO Chamber) to investigate the efficacy and safety of PLK in children from 10 to 15 years old with seasonal AR (SAR) due to Japanese cedar (JC) pollen. Eighty-four subjects were enrolled and randomized to the treatment arm and 74 were included in the per protocol set. Subjects received either PLK dry syrup (DS) or placebo for 1 week. They were challenged with JC pollen in the OHIO Chamber for 3 hours. Total nasal symptom scores (TNSSs) were recorded every 30 minutes during the exposure. PLK DS treatment suppressed the TNSS changes from baseline significantly when compared with placebo. The difference in the least square means in TNSS between the PLK DS-treated group and placebo group was -0.37 (95% CI, -0.54, -0.20) with a value of p< 0.0001, showing that PLK DS significantly suppressed the nasal symptoms. Regarding specific nasal symptoms, PLK DS significantly suppressed sneezing, nasal discharge, and nasal obstruction. The effect of PLK DS on nasal obstruction was most prominent, with significant improvement relative to placebo beginning 60 minutes after the start of exposure. No serious adverse events were reported during the study. In this study, PLK DS is effective and safe for treatment in children with SAR.

We demonstrated the efficacy, rapid onset, and long duration of action of BIL in subjects with Japanese cedar pollinosis exposed to cedar pollen using the OHIO Chamber.