Ginichirou Ichikawa

EFFECT OF ERYTHROMYCIN ON OTITIS MEDIA WITH EFFUSION IN EXPERIMENTAL RAT MODEL

To understand the mechanism of erythromycin (EM) on otitis media with effusion, we examined its effects on leukocyte accumulation and expression of adhesion molecules L-selectin and Mac-1, using a rat experimental model Administration of EM inhibited leukocyte (neutrophil) accumulation in the middle ear cavity after LPS stimulation. Moreover, EM downregulated L-selectin expression and inhibited interleukin (IL)-8-induced upregulation of Mac-1 on peripheral blood neutrophils. These finding suggests that EM may improve otitis media with effusion by inhibiting neutrophil accumulation in the middle ear cavity through modulating the expression of adhesion molecules L-selectin and Mac-1 on peripheral blood neutrophils.

Effect of new macrolides on the expression of adhesion molecules on neutrophils in chronic sinusitis.

To elucidate the mechanisms involved in the action of new macrolides on chronic sinusitis, we examined the effects of clarithromycin (CAM) and roxiythromycin (RXM) on the expression of adhesion molecules (L-selectin and Mac-1) on peripheral blood neutrophils of individuals with chronic sinusitis. The administration of CAM and RXM slightly inhibited the down-regulation of L-selectin expression on neutrophils induced by interleukin (IL)-8 stimulation. Furthermore, the administration of CAM strongly inhibited the IL-8-induced up-regulation of Mac-1 expression on neutrophils. These observations suggest that the new macrolides such as CAM and RXM may affect the functions of neutrophils in chronic sinusitis by modulating the expression of L-selectin and Mac-1 molecules on neutrophils, thereby attenuating the adhesion of neutrophils.

Modulation of neutrophil adhesion to vascular endothelial cells in rat experimental otitis media treated with a macrolide

OBJECT We previously reported that erythromycin (EM) affected the adhesion molecules that interact with neutrophils and inhibited neutrophil infiltration in a rat experimental otitis media model. PURPOSE The purpose of the present study was to examine whether EM affects the adhesion of rat neutrophils to endothelial cells. METHODS The adhesion of neutrophils to WK-5 endothelial cells was evaluated. One group of rats was given EM for 2 weeks, while the other group received no treatment. The adhesion of peripheral-blood neutrophils and neutrophils accumulated in the middle ear from these two groups were compared. RESULTS Two-week EM pretreatment inhibited adhesion of neutrophils to WK-5 cells. The adhesion of neutrophils accumulated in the middle ear cavity to WK-5 cells was significantly higher than that of peripheral-blood neutrophils from control rats. CONCLUSION The results suggest that EM affects the adhesion of neutrophils to endothelial cells.

Study of Expression of L-Selectin and Mac-1 in Pre- and Post-Operative Patients with Obstructive Sleep Apnea Syndrome

In obstructive sleep apnea syndrome (OSAS), it has recently been reported that complications such as hypertension, ischemic heart disease, and cerebral disease occur at high rates. In this study we assessed the function of neutrophils in patients with OSAS. By taking blood samples before and after operative treatment, we measured the levels of neutrophil-adhesive molecules, L-selectin and Mac-1.

Neuro-otological Examination of Olivo-Ponto-Cerebellar Atrophy.

The main clinical findings of OPCA include cerebellar symptoms, extrapyramidal symptoms, autonomic nerve symptoms, in addition to various oculo-motor disturbances. We reported a case of OPCA where neuro-otological examination facilitated the diagnosis. Neuro-otological examination was carried out in 6 cases of OPCA, and duration of illness and experimental findings were compared.Subject: Neuro-otological examination was undertaken in 6 OPCA patients over a 5 year period 1993-1997. The mean patient age was 53.8 years, and the ratio of males to females was 2:4. Duration of illness was 3 years for 2 patients, 4 years for 2 patients, 6 years for 1 patient and 8 years for 1 patient.Method: For all patients, the following examinations were carried out. (1) audiogram, ABR (2) nystagmus (3) eye tracking (4) optokinetic nystagmus, saccade (5) visual suppression.Results: Smooth pursuit eye movement impairment was independent of the duration of illness. Nystagmus findings, saccadic eye movement and the visual suppression test revealed that impairment increased in patients whose duration of illness was more than around 4 to 6 years. The oculo-motor disturbances of OPCA start with impairment of cerebellar and smooth pursuit eye movement, and eventually result in brainstem disorders such as saccadic eye movement and visual suppression. As the duration of illness lengthens, the oculo-motor system itself will no longer function and response to all of the examinations will be lost. Neuro-otological examinations were found to be valuable for the diagnosis of OPCA.