Masashi Ozawa

Suppression of IgE Antibody Production after Exposure to Ozone in Mice

The effect of ozone exposure on IgE antibody production with aerosolized ovalbumin (OA) administration was investigated in Balb/c mice. Mice were continuously exposed to 0.8 ppm ozone for 1, 2, or 4 weeks, respectively, and subsequently aerosolized OA was administered through the respiratory tract for 6 min with a nebulizer. The mice were then immunized intraperitoneally 1 week later with OA. IgE antibody production was suppressed in ozone-exposed mice. However, no significant difference in the primary IgE antibody production by intraperitoneal immunization alone with OA was observed between ozone-exposed mice and nonexposed mice. In order to elucidate the suppressive mechanism of IgE antibody production, hapten-carrier antigenic system was used. It is shown that the induction of helper T cell function was suppressed if the aerosolized carrier protein was administered before intraperitoneal immunization in the mice exposed to ozone. These results suggest that ozone exposure has the effect on the stage of administration of inhaled antigen and the quite insignificant effect on the IgE antibody production after intraperitoneal immunization with OA.

Adjuvant Effects of Aluminum Silicate on IgE and IgG1 Antibody Production in Mice

The adjuvant effects of aluminum silicate on IgE and IgG1 antibody production were investigated. BALB/c mice were immunized intraperitoneally with 10 micrograms ovalbumin (OA) adsorbed on 0.2, 2, or 20 mg aluminum silicate. The enhancement of anti-OA IgE antibody production was observed in the mice injected with aluminum silicate and antigen compared with the mice injected with antigen alone. Anti-OA IgE antibody production with 2 and 20 mg aluminum silicate was greater than that with aluminum hydroxide (alum) as an adjuvant. Similar adjuvant effects with 2 mg aluminum silicate or alum were observed in AKR and C57BL/6 mice using 10 micrograms OA, and in BALB/c mice using 2 micrograms DNP-KLH (dinitrophenyl keyhole limpet hemocyanin): IgE antibody production induced by aluminum silicate adjuvant persisted for weeks in these experiments. The enhancement of IgG1 antibody production to OA mixed with aluminum silicate was also demonstrated. However, no difference between aluminum silicate and alum was observed on the IgG1 antibody production.

Induction of IgE Antibody Production to Aerosolized Ovalbumin in Mice Treated Intratracheally with Aluminum Silicate

Induction of IgE antibody production was studied in mice with aerosolized antigen exposure and intratracheal instillation of adjuvants. BALB/c mice were immunized intratracheally with 10 micrograms ovalbumin (OA) adsorbed with or without aluminum silicate as an adjuvant. A primary IgE antibody production was observed in mice immunized with OA plus adjuvant, but not with OA alone. In mice immunized with OA plus adjuvant, a secondary IgE antibody production was observed after a booster of OA aerosol exposure on day 28. Mice were instilled intratracheally with aluminum silicate or aluminum hydroxide (alum) and subsequently exposed to aerosolized OA for 30 min. Primary and secondary anti-OA IgE antibody productions were obtained in the groups instilled with the adjuvants. After the intratracheal instillation of alum, aluminum remained in the mice for a long period. These results suggest that the intratracheal instillation of adjuvants is effective in the induction of IgE antibody production by aerosolized antigen exposure.

Technique for Endoscopic Endonasal Sinus Surgery

Endoscopy enables us to avoid complications and achieve complete surgery of the ethmoid sinus, nasofrontal duct, and fontanelle under clear observation. By connecting a CCD camera, a surgeon can carry out an operation while watching the image on a TV monitor. Rigid 0° and 70° endoscopes are used. The 0° endoscope is selected for the ethmoid portion of the operation, and the 70° endoscope is used for treatment of the nasofrontal duct and the fontanelle. Use of various forceps has made it possible to treat the nasofrontal duct and the fontanelle and to establish a wide communication. In practice, intranasal procedures are conducted close to the anatomical location of the ground lamella (gl) in the ethmoid sinus. We discussed our technique for endoscopic endonasal sinus surgery for pansinusitis.

Enhancement of antibody response in Japanese quails by acute NO2 exposure

The effect of acute exposure to nitrogen dioxide (NO2) on anti-SRBC antibody response in two lines of Japanese quails, high and low responder, was investigated. Mean survival time of 11- to 13-week-old quails after exposure to 20 ppm NO2 was 12.0 hr. The high responder line lived longer than the low responder line. Changes of spleen weights of both lines were not observed in 10- and 20-ppm NO2 exposure for 4 hr. Anti-SRBC antibody response in high responder quail was significantly enhanced by 20-ppm NO2 exposure for 4 hr and the response in low responder quail was slightly enhanced. A similar, although somewhat less pronounced, tendency was observed also after 10-ppm NO2 exposure. These results suggest that acute NO2 exposure enhances the antibody response of Japanese quails.