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Biomedical subjects

X Baur

Publications and source records attributed to X Baur.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Diagnosis of humidifier lung--comparison of various serologic procedures].

Humidifier lung is a form of exogenous-allergic alveolitis caused by microbial growth in humidifiers and air conditioners. It was the aim of the present study to employ and test the ELISA method as an alternative to antibody determination. 134 employees in a large printhouse equipped with air conditioning plant were examined by us. Specific IgG antibodies against contaminated humidifier fluid were determined by means of a solid-phase radioimmunoassay (protein A RAST) that we had developed further. Alternatively we examined a commercially available ELISA method (Pharmacia IgG-RAST 40; enzyme: beta-galactosidase) and an assay based on protein A peroxidase. The influence of different test conditions was studied. All the methods examined proved suitable for determining the specific IgG antibodies. The commercial beta-galactosidase assay could be adapted to application on microtitre plates in a slightly modified form. In the peroxidase assay it is recommended to use very low serum and enzyme concentrations on account of its high sensitivity. Examination of all the 134 serum samples yielded a high correlation between the results of these two non-radioactive methods and those obtained with the protein-A RAST.

Air Microbiology↗
PubMed1991

[Pearl oyster dust as the cause of exogenous allergic alveolitis].

Many different inhalative substances may cause allergic alveolitis (hypersensitivity pneumonitis). We report on a worker who developed lung fibrosis due to the sensitization to pearl oyster shell dust. High concentrations of IgG antibodies to proteins (conchagens) of the shell which appear to represent the relevant antigens were found in the patient's serum.

Aged↗
PubMed1991

[Correlation of parameters of the flow-volume curve for the assessment of bronchial hyperreactivity].

The association of maximal expiratory flow-volume curve and the response of nonspecific bronchial responsiveness was studied in 265 normal and asthmatic subjects. Bronchial hyperresponsiveness to acetylcholine was found in 143 subjects. These hyperreactive persons had already significantly reduced maximal expiratory flow rate at 75%, 50% and 25% vital capacity before the test started. Besides, we found a significant correlation between the provocative dose and the flow-volume parameters, although resistance was in the normal range. We concluded that the flow rates at middle and low lung volumes may be an important determinant of bronchial sensitivity to acetylcholine.

Acetylcholine↗
PubMed1991

Evaluation of the Radio-Allergo-Sorbent-Test (RAST) with respect to misinterpretations of the results.

Two hundred and twenty two single allergens were assayed in 36 outpatients, using a commercial RAST kit. It was found that a significant proportion of the patients were evaluated incorrectly as having elevated levels of allergen-specific IgE. This was due to an as yet unconsidered parameter of the RAST, i.e. unspecific binding of the radioactive tracer to the wall of the test tubes, resulting in values that did not correlate with the total IgE concentrations of individual sera. The unspecific binding amounted in some cases to 89% of the total radioactivity (counts/min) when the instruction manual of the manufacturer was followed. This resulted in either false positive results and/or RAST classifications that were 1 to 2 classes too high. The results can be corrected by a slight modification of the assay.

Allergens↗
PubMed1990

[Various forms of humidifier lung].

Clinical and immunological investigations of 15 workers in a repro-printing house revealed a prevalence of 7% for the occurrence of humidifier-lung. Serological sensitization to humidifier water and fungi respectively was found in 73%, fragmentary symptoms in 53%. In comparison to smokers, elevated antibody levels occurred more frequently in nonsmokers (33% vs. 100%). The results are supposed to reflect subclinical stages of disease, but they are not yet of a definite predictive value. Reduction of microorganisms in humidifiers seems to be essential for the prevention of disease.

Adult↗
PubMed1990

[Bronchial asthma in a hairdresser caused by hair bleach].

Three years after starting to work as a hairdresser a 33-year-old woman developed urticaria on contact with hairbleach. After a further four years rhinoconjunctivitis set in and later also bronchial asthma on contact with such bleaches. Extensive tests revealed hypersensitivity to widely used persulphate-containing bleaching liquids which ultimately forced the patient to give up her profession. The causative role of this group of chemicals was proven by positive skin tests and specific workplace-related provocation tests. But specific IgE antibodies could not be demonstrated. The findings suggest a pseudoallergic reaction.

Adult↗
PubMed1990

[Occupational respiratory tract allergies].

Numerous occupation-related substances of plant, animal, microbial and chemical origin are potent immunogens and allergens. In the Federal Republic of Germany, the most common form of occupational obstructive airways disease is baker's asthma, caused by the inhalation of flour dust and other related substances. Compliance with the industrial threshold limit values (TIL) at the workplace reduce the risk of contracting disease, but cannot exclude it completely. Apart from obtaining a detailed history, and performing a physical examination, the diagnostic work-up also requires inclusion of special allergy tests (prick, intradermal, RAST)--in equivocal cases also, after a prior exposure--free preparatory period, re-exposure and inhalative work-place-related provocative testing. Therapeutically, elimination of exposure heads the list of measures; in concrete terms, this can also mean a change of occupation or even occupational re-training.

Allergens↗
PubMed1990

[Baking ingredients, especially alpha-amylase, as occupational inhalation allergens in the baking industry].

Baker's asthma is the most frequent occupational lung disease in Switzerland and West Germany. Cereal flours, and more rarely flour parasites, are implicated as the responsible allergens. Based on an observation of a case of baker's asthma due to monovalent sensitization to alpha-amylase used as additive to flour, 31 bakers with occupational asthma and/or rhinitis were routinely tested by skin tests and serological RAST examinations for allergic sensitivity to flour, alpha-amylase and other bakery additives. 17/31 subjects (55%) reacted positively in scratch tests to a commercial powdered alpha-amylase and 13/20 (65%) to a lecithin preparation. 23/31 (74%) and 19/31 (61%) were RAST positive to wheat and to rye flour respectively. 32% had RAST specific IgE to alpha-amylase (from Aspergillus oryzae), 19.3% to soya bean flour and 16% to malt. 7/12 and 5/12 respectively reacted to trypsin inhibitor and lipoxidase, the main allergens in soya bean. In two patients monosensitization to alpha-amylase was present. In accordance with other reports we recommend that baking additives, especially alpha-amylase, should be tested in allergological diagnosis of occupational diseases in flour processing workers. Full declaration of all additives used in the bakery industry is needed.

Adolescent↗
PubMed1990

Allergen-directed expression of Fc receptors for IgE (CD23) on human T lymphocytes is modulated by interleukin 4 and interferon-gamma.

T lymphocytes bearing Fc receptors (FcR) for immunoglobulins are known to have immunoglobulin class-specific regulatory functions. Here we report that expression on T cells of the low-affinity FcR for IgE (Fc epsilon RII/CD23) is preferentially induced by stimulation with antigens that cause an IgE response. T cells from eight patients allergic to the hemoglobin of Chironomus thummi thummi mosquito larvae (CHIT I) were analyzed for reactivity with the anti-FcERII/CD23 monoclonal antibody (mAb) M-L25 under various conditions. No Fc epsilon RII/CD23+ T cells were observed among freshly isolated, resting peripheral blood mononuclear cells (PBMC). Stimulation of PBMC with CHIT I, however, induced a marked although transient Fc epsilon RII/CD23 expression on a large portion of the allergen-activated T lymphocytes. It reached a maximum of 37.2 +/- 4.6% Fc epsilon RII/CD23+ T cell blasts on day 5 of culture. The selectivity of this expression became evident when compared to non-allergenic control antigens: after stimulation of PBMC with tetanus toxoid or purified protein derivative from tuberculin a maximum of 4.6% +/- 1.4% and 4.2% +/- 1.1% T cell blasts was found to express Fc epsilon RII/CD23, respectively. Activation by an anti-CD3 mAb was insufficient to induce Fc epsilon RII/CD23 on T cells. The allergen-stimulated Fc epsilon RII/CD23+ T cells exclusively belonged to the CD4+CD29+ helper inducer T cell subset. Using a cDNA probe coding for the B cell Fc epsilon RII/CD23, Northern blot analysis revealed a 1.7-kb Fc epsilon RII/CD23 mRNA in extracts of highly purified allergen-stimulated T cells. It was of the same size as Fc epsilon RII/CD23 mRNA of the lymphoblastoid B cell line WI-L2. Of several cytokines tested [interleukin (IL) 1 to IL 6, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha] only IL 4 and IFN-gamma significantly modified allergen-induced Fc epsilon RII/CD23 expression on T cells. The latter was enhanced nearly twofold in the presence of IL 4, and was almost completely abrogated by IFN-gamma. IL 4, however, could not increase the number of Fc epsilon RII/CD23+ T lymphocytes either alone or in combination with an anti-CD3 mAb. Taken together, the selective induction of Fc epsilon RII/CD23 on T cells by allergen and its inclusion in the regulatory network of cytokines point to an important role of Fc epsilon RII/CD23+ T lymphocytes in the human IgE response.

Allergens↗
PubMed1990

New aspects of isocyanate asthma.

Air concentration of isocyanates are associated with the frequency of induced diseases. Asthma, bronchitis and rhinitis, chronic obstructive lung disease, and allergic alveolitis, respectively, were observed in exposed workers. Inhalation challenge tests with isocyanates found some 14% of symptomatic persons immunologically sensitized. At and above current threshold limit values (10 ppb) there is a risk of lung function deterioration also in asymptomatic workers.

Air Pollutants, Occupational↗
PubMed1990

Histamine release from human basophils by the insect allergen Chi t I.

Hemoglobins of the Diptera species Chironomus thummi thummi (Chi t I) are potent inhalant allergens. Chi t I-specific histamine release was measured by a new radioimmunoassay in whole human blood taken from 20 sensitized patients, 11 exposed nonsensitized probands, and 11 nonexposed controls. The sensitized patients, who all had positive skin tests and radioallergosorbent test results with Chi t I, showed a significantly higher histamine release than the two other groups. However, within the patient group, the percentage of released histamine did not correlate with the intensity of the skin test response or the concentration of Chi t I-specific IgE antibodies. Our results demonstrate that this method is a sensitive and specific in vitro test for evaluation of IgE-mediated sensitization.

Adult↗