[Prevalence rate of allergy to Japanese cedar pollen in Tokyo--from field investigation in 1996 by Tokyo Japanese Cedar Pollen Allergy Measurements and Review Committee].

Prevalence rate of allergy to Japanese cedar pollen was investigated by means of questionnaires and immunological examinations in residents of 3 regions in Tokyo (Akiruno city, Chofu city, and Ota ward). The results were as follows: 1) the prevalence rate of allergy to Japanese cedar pollen in Tokyo was 25.7% in Akiruno city, 21.1% in Chofu city, and 17.7% in Ota ward in 1996; 2) stratification by the age reveal that the prevalence rate was the highest in the age group of 30 to 44, and the group showed prevalence rate of above 40% in Akiruno city; 3) overall prevalence rate of Tokyo was 19.4% in 1996, which was approximately twice as much as that in 1985; 4) increase in prevalence rate in the recent decade was most significant in Akiruno city where the largest number of Japanese cedar pollen was detected in the air, and prevalence rate tended to rise in the young group of 14 or less.

[Assumption of the area supplying Okayama Prefecture with Cryptomeria japonica and Cupressaceae airborne pollen, and of their scattering routes].

It is very important to predict and disseminate information about the total pollen counts of both Cryptomeria japonica and Cupressaceae for patients with pollinosis. In Okayama Prefecture, we have reported that the pollen counts of both Cryptomeria japonica and Cupressaceae are influenced by the meteorological conditions in the previous July. We predicted the area supplying Okayama Prefecture with Cryptomeria japonica and Cupressaceae pollen, and also the route of airborne pollen from the meteorological conditions and a topographical map of Okayama and four neighboring prefectures. It was found that Cryptomeria japonica and Cupressaceae pollen counts at the four observation sites correlated very well with the meteorological conditions at Tsuyama weather station in Okayama prefecture. Therefore, we considered that the areas supplying Okayama prefecture with Cryptomeria japonica and Cupressaceae pollen were the central northern areas including Tsuyama, 85.7% of whose plantation areas contained Cryptomeria japonica and Chamaecyparis obtusa, and that their pollen was carried along the routes of three major rivers, R. Takahashi, R. Asahi and R. Yoshii.

[Epidemiological survey on orchard pollinosis].

OBJECTIVE: To investigate the prevalence of Orchard Pollinosis in China. METHOD: From 1995 to 1998, an epidemiological survey on orchard pollinosis was carried on among 1,660 primary and middle school students and 2,167 university students, including questionnaire investigation, nasal inspection and scratch test. From April to June of 1998, a clinical investigation of orchard pollinosis was adopted among 30 patients of allergic rhinitis including scratch test and nasal mucosa test. RESULT: 1. The total positive rate of orchard pollen scratch test was 6.7%, and the prevalence of orchard pollinosis was 0.37%. 2. 5 cases (16.7%) were hypersensitive to orchard pollen clinically in allergen test. CONCLUSION: Orchard pollinosis is one kind of important pollinosis and should be paid high attention to.

[Forecast of the beginning day of Japanese cedar pollen release using variation pattern in air temperature].

It is important to forecast the beginning day of Japanese cedar pollen release for taking the preventive medical measure. We analyzed the relation between the beginning day of pollen release and the changing pattern of daily air temperature. A simple and practical method for forecasting the beginning day of pollen release is suggested. Polynomial of degree three was applied to represent the general variation pattern of air temperature. Multiple correlation coefficients between parameters of the polynomial and the beginning days of pollen release were 0.88 for the difference by year, and 0.81 for the difference by place. It was shown that the minimum value and the date of the fitted polynomial curve were related closely to the difference in the beginning day of pollen release by year. The minimum value and the date of the original series of air temperature showed high correlation with the difference in the beginning day of pollen release by place. We propose to use the minimum value and the date of original series and fitted curve of air temperature for forecasting the beginning day of cedar pollen release.

Yearly and seasonal changes of specific IgE to japanese cedar pollen in a young population.

BACKGROUND: There have been no detailed long-term observations of the relationship between specific IgE production and stimulation by various naturally occurring allergens. OBJECTIVE: This study was conducted to elucidate the yearly and seasonal changes of specific IgE antibody production to Japanese cedar pollen, an allergen of Japanese cedar pollinosis, in young adults. METHODS: The number of Japanese cedar pollen were counted over a period of 9 years. Changes in the percentages of antibody carriers to Japanese cedar pollen and mite were examined during these years. Changes in Japanese cedar pollen-specific IgE levels between a low exposure year and a high exposure year in individual subjects were also investigated. RESULTS: From 1987 to 1995, the percentages of Japanese cedar pollen-IgE carriers varied from about 30% to 50% with the intensity of pollen stimulation, and carriers tended to increase yearly. The rates of anti-mite IgE carriers changed little. In the spring which is the pollen season, Japanese cedar pollen-IgE levels in low exposure years were weaker than those in high exposure years in individual subjects. Levels in autumn, which is not the pollen season, showed equivalent levels in both high and low exposure years. Anti-mite IgE levels in individual subjects varied little during these years. CONCLUSIONS: A long-term follow-up study supported that Japanese cedar pollen-IgE production is mainly associated with the degree of allergen exposure.

Allergic conjunctivitis caused by sugi (Cryptomeria japonica D. Don) pollen out of season.

Allergic conjunctivitis caused by sugi pollen is considered to be strictly a "spring disease". However, a recent report indicated that sugi pollen is scattered not only in spring but in all seasons, especially in the autumn. We retrospectively determined the number of patients with allergic conjunctivitis caused by sugi pollen during each month for 3 consecutive years, and also investigated the growth of sugi male cones in November for four years. Diagnosis of allergic conjunctivitis was based on symptomatic complaints, clinical findings, and serum sugi pollen specific IgE measured by the Multiple Antigen Simultaneous Test 16. The annual incidence of allergic conjunctivitis peaked twice, once in spring and again in autumn. Scattering of sugi pollen occurred mostly in March and October, whilst the growth of sugi male cones was highest in November. Thus, allergy to sugi pollen can cause allergic conjunctivitis both in the spring and late autumn.

Change in the northward movement of the pollen front of Cryptomeria japonica in Japan, during 1986-1991.

A map of pollen fronts of Cryptomeria japonica was compiled from pollen counts taken at 28 airborne sampling sites in Japan in 1986. Thereafter, the number of sites was increased, reaching 80 in 1991. In this way an accurate and complete map of the C. japonica pollen fronts was compiled annually. We used the results obtained from mapping the pollen fronts to draw up a map of the average locations of the front, from which the beginning of the pollen season can be predicted. A close correlation was found between the latitude of the airborne sampling sites and the mean interval between January 1 and the day pollen release began during these 6 years.