Differences in the sensitisation to ragweed pollen and occurrence of late summer allergic symptoms between native and immigrant workers of the nuclear power plant of Hungary.

Regular medical screening including allergic symptoms of workers of the Nuclear Power Plant in Paks, Hungary, offered a unique opportunity to study the influence of the environmental factors on the development of allergy. The city Paks has been one the areas of the country most heavily exposed to ragweed pollen allergens. The occurrence and extent of sensitisation assessed by skin prick test to common allergens and prevalence of seasonal and perennial allergic symptoms were compared among 880 workers (695 immigrants, 185 natives) with self-reported allergic symptoms. The percentage of sensitised people against common allergens (ragweed, grass, D. pteronyssinus) was almost the same in the natives and immigrants. When, however, the strength of sensitivity to ragweed was determined by quantitative skin prick test and specific IgE determination, significantly (P<0.0001) more immigrants (69%) than native workers (20%) exhibited high sensitivity to ragweed and the titres of specific IgE antibodies was also significantly (p < 0.0001) higher in the former group. Similar differences were found in the occurrence and type of allergic symptoms. Seasonal symptoms alone occurred in 69% and 38% of the immigrant and native workers (p < 0.0001). This difference was mostly due to those with late summer symptoms characteristic to ragweed allergy. These symptoms occurred in 57% of the immigrant workers, much more frequently (p < 0.0001) than in the natives (18%). Our findings indicate that the length of exposure to an inhalant allergen does affect the extent of sensitisation to ragweed allergen and markedly influences the clinical symptoms that develop in the ragweed allergic patients upon allergen exposure. It can be assumed that the natives who have been living with ragweed pollen for a long time (that is were exposed to natural immunotherapy), developed a natural tolerance to it.

Ophthalmologic screening of deaf students in Oregon.

PURPOSE: To determine the frequency of Usher's syndrome and other ocular disease in students receiving special education services for the deaf in Oregon and to assess the amount of existing ophthalmologic surveillance of this population. A special emphasis was placed on screening for Usher's syndrome. METHODS: From 1980-1990, a prospective two-center visual screening program of 231 deaf students in schools throughout Oregon was conducted using an ophthalmic questionnaire, complete eye examinations, and electroretinography. Students were between the ages of 10 and 21 years and participated on a volunteer basis. Findings for etiology and severity of visual loss and the scope of ophthalmologic surveillance within this population were analyzed. RESULTS: Two hundred seventeen of the 231 students examined received electroretinograms. Significant ocular pathology was found in 111 (48%) of the students. The most common diagnoses were congenital rubella (21%), significant uncorrected ametropia (16%), and ocular hypertension (9%). Five students were diagnosed with Usher's syndrome. Of the students with significant ocular pathology, only 37% were actively followed by an ophthalmologist. CONCLUSION: Deaf students in Oregon's schools had a high frequency of eye disease. Early diagnosis and treatment of eye disease in this population could benefit the quality of life of these students. This study alerted the providers of special education services for the deaf and the ophthalmologic community in Oregon of the need for better eye care for these students.

Congenital abnormalities and indicators of germinal mutations in the vicinity of the Paks nuclear plant, Hungary.

The objective of the study was to check the occurrence of phenotypic manifestations of germinal mutations in children born within a 30 km radius of the Paks nuclear power plant, Hungary. The study took the form of a comparative analysis between observed and expected rates based on the Hungarian baseline rates, as well as between children born before and after the operation of the nuclear plant. Data were taken from the database of the Hungarian Congenital Abnormality Registry completed by active search in the study region, and comprised 26 893 children born between 1980 and 1992 in the 55 settlements of the study region. The results were presented as overall figures as well as being grouped by different congenital abnormalities, in addition to the so-called indicators of germinal mutations: sentinel anomalies, Down syndrome and unidentified multiple congenital abnormalities. The observed occurrence of all but one group of congenital abnormalities corresponded to the expected rate, as did the three groups of indicator conditions. Of the 55 settlements, eight had spatial clusters; however, these could be explained by overdiagnosis or chance. There was no significant increase in the variables studied after the operation of the nuclear plant. We conclude that the slightly elevated radiation background (0.2-0.4 microSv/year) due to the operation of the nuclear plant studied does not affect germinal and somatic mutations in children.

In vitro complement activation by ragweed allergen extract in the sera of ragweed allergic and non-allergic persons.

Ragweed allergen (RWA)-induced complement activation in sera of 40 RW allergic patients and of 40 non-allergic controls was investigated. After treatment of the sera with RWA, levels of C3a, C5a, C3bBbP, C1rC1sClinh, SC5b-9 and granulocyte-aggregating activity were determined. Concentration of RW-specific IgG was also measured. After RWA treatment dose-dependent complement activation was detected in sera of RW allergic and non-allergic persons. C3a generation was observed mostly in the sera of RW allergic individuals, while levels of C3bBbP and of RW-specific IgG were significantly higher in sera of allergics, and a strong correlation was found between these two parameters. In a prospective clinical study, a significant positive correlation was observed between the extent of RWA-induced alternative pathway (AP) activation and the severity of symptoms of allergic rhinoconjunctivitis that were developed in a 4-week period subsequent to blood sampling. These observations suggest that complement activation has a role in the development of the symptoms of RW allergy.

Micronucleus frequency in cultured lymphocytes of an urban population.

The frequencies of micronuclei in cultured cytokinesis-blocked lymphocytes of an urban industrial population of 188 persons were determined. For the mean and SD, 16.0 +/- 7.3 per 1000 CB cells were obtained. A slight but definite age dependence--appr. 0.2/1000 increase per year on average--was indicated by thorough statistical analysis.

Using the micronucleus assay to detect genotoxic effects of metal ions.

The lymphocyte micronucleus assay was used to measure the average frequency of micronuclei in a population and thus assess genotoxic effects. Data from 174 persons give an average value of 16.4 +/- 7.3, and a slight age-dependence was observed. To detect combined environmental mutagen injuries the micronucleus assay was used to study the effects of metal compounds. Cadmium ions increased the micronucleus frequency linearly after incubation with whole blood in vitro with 10(6)-10(-3) M concentrations for 30 min. Similarly, a linear increase in micronucleus frequency was detected with 10(-3)-10(-1) M mercury ions. Concerning the biological effect of selenium, it was found that neither sodium selenite nor selenium dioxide induced increases at concentrations of 10(-7)-10(-6) M; 10(-5) M caused a slight increase; 10(-4) M, however, destroyed the cells. These results suggest that the human lymphocyte micronucleus test can be used to assess genotoxic injuries due to environmental effects in human lymphocytes.