Biomedical subjects

Kenichi Kanai

Publications and source records attributed to Kenichi Kanai.

3 recordsLinked to original sources

PubMed2005

The effect of exogenous spatial attention on auditory information processing.

This study investigated the effect of exogenous spatial attention on auditory information processing. In Experiments 1, 2 and 3, temporal order judgment tasks were performed to examine the effect. In Experiment 1 and 2, a cue tone was presented to either the left or right ear, followed by sequential presentation of two target tones. The subjects judged the order of presentation of the target tones. The results showed that subjects heard both tones simultaneously when the target tone, which was presented on the same side as the cue tone, was presented after the target tone on the opposite side. This indicates that spatial exogenous attention was aroused by the cue tone, and facilitated subsequent auditory information processing. Experiment 3 examined whether both cue position and frequency influence the resulting information processing. The same effect of spatial attention was observed, but the effect of attention to a certain frequency was only partially observed. In Experiment 4, a tone fusion judgment task was performed to examine whether the effect of spatial attention occurred in the initial stages of hearing. The result suggests that the effect occurred in the later stages of hearing.

Attention↗

PubMed2005

Suppression of matrix metalloproteinase production in nasal fibroblasts by tranilast, an antiallergic agent, in vitro.

Allergic rhinitis is an inflammatory disease characterized by nasal wall remodeling with intense infiltration of eosinophils and mast cells/basophils. Matrix metalloproteinases (MMPs), MMP-2 and MMP-9, are the major proteolytic enzymes that induce airway remodeling. These enzymes are also important in the migration of inflammatory cells through basement membrane components. We evaluated whether tranilast (TR) could inhibit MMP production from nasal fibroblasts in response to tumor necrosis factor-alpha (TNF-alpha) stimulation in vitro. Nasal fibroblasts (NF) were established from nasal polyp tissues taken from patients with allergic rhinitis. NF (2 x 10(5) cells/mL) were stimulated with TNF-alpha in the presence of various concentrations of TR. After 24 hours, the culture supernatants were obtained and assayed for MMP-2, MMP-9, TIMP-1, and TIMP-2 levels by ELISA. The influence of TR on mRNA expression of MMPs and TIMPs in cells cultured for 12 hours was also evaluated by RT-PCR. TR at more than 5 x 10(-5) M inhibited the production of MMP-2 and MMP-9 from NF in response to TNF-alpha stimulation, whereas TIMP-1 and TIMP-2 production was scarcely affected. TR also inhibited MMP mRNA expression in NF after TNF-alpha stimulation. The present data suggest that the attenuating effect of TR on MMP-2 and MMP-9 production from NF induced by inflammatory stimulation may underlie the therapeutic mode of action of the agent in patients with allergic diseases, including allergic rhinitis.

Adult↗

PubMedDate not supplied

Influence of fluticasone propionate on the production of vascular endothelial growth factor and basic fibroblast growth factor from nasal fibroblasts in vitro.

The influence of fluticasone propionate (FP) on vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) production from nasal polyp fibroblasts (NPFs) was examined in vitro. NPFs, at a density of 2.5 x 10(5) cells/ml, were stimulated with 25 ng/ml TNF-alpha in the presence or absence of FP for 24 h. FP at more than 10(-6) M could suppress VEGF production from NPFs. bFGF production induced by TNF-alpha stimulation was also suppressed by FP, when the agent was added to cell cultures at more than 10(-7) M. The present results also showed the suppressive activity of FP on mRNA expression for VEGF and bFGF, which were increased by TNF-alpha stimulation.

Androstadienes↗