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Biomedical subjects

M C Swanson

Publications and source records attributed to M C Swanson.

45 records · Page 3Linked to original sources
PubMed1986

Occupational allergy to honeybee-body dust in a honey-processing plant.

We studied a honey-plant employee who developed severe asthma coincident with the seasonal honey-packing process. Symptoms correlated with duration of exposure inside the plant during the honey pack and improved in other environments during that season. The patient was asymptomatic inside the plant at other times of the year. Skin tests to seasonal outdoor aeroallergens were negative, as were inhalation challenges with two insecticides used inside the building during the honey pack. Skin test, RAST, and bronchial provocation test with honeybee whole body extract were positive. We used high-volume air samplers to collect ambient airborne particles on filter sheets outside the patient's home and inside the honey plant, both during and after the honey pack. Skin tests, RASTs, and bronchial provocation tests with eluates from these filters were positive only to eluate from the filter exposed inside the plant during the honey pack. The patient's positive honeybee whole body RAST could be inhibited by preincubation of her serum with this filter eluate but not by preincubation with eluate from a filter exposed outside the patient's home. Collectively, these data support an IgE-mediated, seasonal, occupational sensitivity to honeybee-body dust.

Asthma↗
PubMed1985

An immunochemical approach to indoor aeroallergen quantitation with a new volumetric air sampler: studies with mite, roach, cat, mouse, and guinea pig antigens.

We describe a new high-volume air sampler for determining antigen concentrations in homes and illustrate its use for quantitating airborne house dust mite, cat, cockroach, mouse, and guinea pig antigens. The concentration of house dust-mite antigen was similar from houses in Rochester, Minn. and tenement apartments in Harlem, N. Y., but cockroach and mouse urinary proteins were present only in Harlem. The amount of cat or guinea pig antigen varied as expected with the number of pets in the home. In calm air the airborne concentration of mite and cat antigen was similar throughout the house but increased greatly in a bedroom when bedding was changed. In calm air most of the cat and mite antigens were associated with respirable particles less than 5 microns mean aerodynamic mass diameter, but in air sampled after the bedding was changed, more cat antigen was found in particles greater than 5 microns. The apparatus and technique described can provide objective data concerning the magnitude and the relative distribution and duration of suspended particles of defined sizes, which contain allergen activity.

Air Pollutants↗
PubMed1984

Airborne ragweed allergens: association with various particle sizes and short ragweed plant parts.

These investigations were undertaken to size airborne particles by use of a high-volume sampler and to measure the short ragweed allergen activity of airborne particles of different sizes. We found both in vitro and in vivo short ragweed allergen activity in particles of all size ranges including greater than 6, 3 to 6, 1.8 to 3, 1 to 1.8, and 0.3 to 1.0 micron in diameter. Furthermore, we investigated various parts of the short ragweed plant as possible sources of allergen. Plant parts collected before, during, and after the pollination season demonstrated significant in vitro and in vivo allergen activities. We demonstrated allergen activity in various plant parts, especially the inflorescence, as late as November 30. Appreciable ragweed allergenic activity was also associated with particles less than 1 micron in diameter. Collectively, these observations suggest persistent ragweed plant debris in different sized particles as a source of allergen in the air before and after the ragweed pollination season. This may contribute to out-of-season symptoms observed in highly ragweed-sensitive individuals.

Air Pollution↗
PubMed1984

Guinea-pig-derived allergens. Clinicoimmunologic studies, characterization, airborne quantitation, and size distribution.

Of 20 serum samples from laboratory workers who experienced allergic symptoms after exposure to laboratory animals, 9 contained elevated IgE antibodies to guinea pig urine, pelt, or albumin by the radioallergosorbent test (RAST). Skin testing documented allergenic activity with all 3 guinea pig allergens. The cross-reactivity of these 3 guinea pig allergens was studied in RAST inhibition assays. Guinea pig pelt extract and urine produced dose-related inhibition in all 3 assays, but guinea pig albumin was inhibitory in only the homologous assay. Characterization by gel filtration, polyacrylamide gel electrophoresis, and isoelectric focusing demonstrated heterogeneity of the allergens. Air filter samples were taken in a guinea pig housing room, a research laboratory, and a library, using a high volume air sampler. An outdoor air filter sample was also taken. Guinea pig urine allergen activity was detected in all indoor air filter samples by RAST inhibition. Guinea pig pelt allergen activity was detected in all air filter samples, except the library and outdoors. Guinea pig albumin was not detected in any air filter sample. Sizing of airborne particles demonstrated that most guinea pig allergen activity was associated with particles of a diameter greater than 5 mu and less than 0.8 mu. Urine appears to be the major source of guinea pig allergens, and it is present in airborne particles small enough to penetrate the lower respiratory tract when inhaled.

Air Pollutants, Occupational↗
PubMed1983

IgE and IgG-immune mechanisms do not mediate occupation-related respiratory or systemic symptoms in hog farmers.

To determine the frequency and possible immunologic etiology of respiratory and other symptoms after hog barn exposure, we studied 41 hog farmers and their family members. Participants completed questionnaires and provided serum samples for measurement of IgE and IgG antibodies to hog-derived antigens, hog feed, and hog barn dust. Symptoms after hog barn exposure were reported by 85% of participants. Elevated IgE antibody levels to hog pelt, hog urine, and hog serum were found in only one individual; however, skin tests with these materials were negative. By radioimmunoassay, elevated IgG antibody levels to hog barn dust and/or hog feed were found in seven individuals; two of these sera contained precipitating antibodies to hog barn dust and hog feed. In no case could the presence of IgE or IgG antibodies be correlated with symptoms. Thus it appears that neither IgE nor IgG humoral immune mechanisms mediate respiratory or other symptoms in hog barn workers.

Adolescent↗
PubMed1983

Immunochemical quantitation of airborne short ragweed, Alternaria, antigen E, and Alt-I allergens: a two-year prospective study.

We conducted a 2 yr prospective study to measure atmospheric short ragweed and Alternaria allergens by RAST inhibition analysis of eluates from filter sheets exposed in air samplers. In both years ragweed pollen and Alternaria spore counts, obtained with a rotoslide sampler, correlated significantly with immunochemically measured airborne ragweed and Alternaria allergenic activity. Airborne levels of the purified allergens AgE and Alt-I were successfully quantitated; these levels correlated closely with total airborne ragweed and Alternaria allergenic activities, respectively, and also with ragweed pollen and Alternaria spore counts. Eluates from filter sheets exposed during late summer and fall produced positive wheal-and-flare skin tests in patients with fall hay fever. In both years immunochemical measurements of allergenic activity due to airborne short ragweed correlated closely with mean symptom score indices in groups of short ragweed-sensitive individuals. Measurable levels of atmospheric ragweed allergenic activity were noted before and after the ragweed pollination season, and at these times we noted small increases in mean symptom score indices in the short ragweed-sensitive groups. Thus immunochemical analyses provide important information concerning levels of environmental allergens.

Air Microbiology↗
PubMed1983

Measurement of IgG antibody and airborne antigen to control an industrial outbreak of hypersensitivity pneumonitis.

An outbreak of hypersensitivity pneumonitis in a textile plant was attributed on epidemiological grounds to a chilled water air-conditioning system where a slime was growing in the chilled water sump and on demister vanes. All of the patients and about 80% of their asymptomatic co-workers had strongly positive precipitin tests to extracts of the slime. An adaptation of a radioiodinated staphylococcal protein A solid-phase radioimmunoassay was applied to monitor antigen and specific antibody. To control the outbreak, a variety of cleaning and water treatment measures were taken between 1977 and 1979 to reduce the amount of antigen in the water and in the air. The amount of slime in the water was greatly reduced though the antigen content per gram of slime did not change. Airborne antigen in the affected work areas decreased progressively.

Air Conditioning↗
PubMed1981

An immunochemical method to measure atmospheric allergens.

Because particulate aeroallergens may exist in amorphous form as well as in pollen grains and fungal spores and because symptoms of allergic diseases presumably correlate with the total amount of allergen exposure, an immunochemical method of assay of aeroallergens would be useful. We report such a method based on (1) capture of airborne pollen, fungal spores, and amorphous particles 0.3 micrometer in diameter on fiberglass sheets with a high-volume air sampler; (2) elution of the sheets with buffered saline; and (3) analysis of eluate allergen content by radioallergosorbent test (RAST) inhibition assays. In preliminary indoor experiments we applied various quantities of short ragweed (SRW) pollen or dry Alternaria powder to the sheets while airflow was maintained at 1.19 m3/min. We compared techniques for extraction of allergen from the sheets, including homogenization, cutting and soaking, and descending elution of sheets. Although all three methods successfully extracted allergen from the sheets, an 8-hr descending elution procedure was optimal from the standpoint of yield and convenience. Eluates from filters exposed to as little as 4 mg of SRW pollen or Alternaria powder produced satisfactory RAST inhibition curves. When the sampler was operated outdoors continuously we could measure the atmospheric allergenic activity for both Alternaria and SRW from July to September. This allergenic activity was highly correlated with the traditional morphologic counts of airborne ragweed pollen and Alternaria spores.

Allergens↗