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Biomedical subjects

X Baur

Publications and source records attributed to X Baur.

318 records · Page 18Linked to original sources
PubMed1979

[Occupational asthma and dermatitis after exposure to dusts of persulfate salts in two industrial workers (author's transl)].

Two workers developed dermatitis, rhinitis, bronchitis, and asthma after occupational exposure to dusts of persulfate salts. The causative role of the persulfate salts could be confirmed by case history, skin tests, occupational exposure tests and by removal of the 2 workers from their jobs. Patch tests produced late cutaneous reactions. Occupational exposure at the working place for 8 h resulted in each case in a pathological increase of airway resistance. Withdrawal from occupational exposure to persulfate salts resulted in recovery within a few days. Our results suggest that chemically irritative or toxic effects of persulfate salts play the predominant role in the pathogenesis of the reported cases.

Adult↗
PubMed1979

[On the pathogenesis of isocyanate-induced asthma].

3 asthmatic patients, occupationally exposed to vapors of toluylene diisocyanate (TDI), responded with a moderate to strong elevation of airway resistance up to the 26th h after inhalation challenge by 0.006--0.02 ppm TDI. No changes in chest radiographs and in DLCO were found. In none of the patients' sera, isocyanate-specific antibodies could be detected by RAST and Ouchterlony test. Change of job resulted in one case in an immediate interruption of the asthmatic symptoms, whereas in 2 patients recovery was slow over a period of 3 to 8 months and not complete. Our investigations suggest a toxic effect of isocyanates, which depends on their concentrations, and an important pharmacological reaction; but, up to now, there were no signs of allergic mechanisms.

Adult↗
PubMed1979

[Immunological examination of lymphocytes in patients with sarcoidosis and bronchial asthma (author's transl)].

Blood lymphocytes of 31 patients with bronchial asthma and of 20 patients with sarcoidosis were isolated and investigated for the following surface markers: E-receptors (E-rosettes, a T cell characteristic), Fc-receptors (EA-rosette assay), C3-receptors (EAC-rosette assay), surface immunoglobulins (immuno-fluorescence technique). In addition, the reactivity against allogeneic lymphocytes was tested in mixed lymphocyte culture (MLC). MLC properties were defined by homozygous reference cells (so-called LD-typing). HLA-typing was performed simultaneously. The results, so far, indicate in both disease groups a series of remarkable alterations of the lymphatic subpopulations. A marked diminution of circulating T lymphocytes was encountered in some cases. The immunological results are discussed in relation to pathogenetic aspects of the diseases.

Asthma↗
PubMed1979

[Bronchial asthma of allergic or irritative origin as an occupational disease (author's transl)].

The development or exacerbation of an asthmatic condition is more often than is commonly realized attributable to the inhalation during work of substances which have either antigenic properties or induce physico-chemical damage to the mucous membranes. The following substances were found to play a causal role in the development of asthma in exposed persons: penicillin dust, dust inhaled during the threshing of grain, persulfate, formalin, inorganic cooling agents. Procedures to ascertain the aetiology of these occupation-induced obstructive bronchial disease are reviewed. The inhalation challenge test, exposure tests at the place of work and removal of the affected person from contact with the suspected antigen are discussed in respect of their diagnostic value.

Asthma↗
PubMed1978

[Allergy diagnosis in patients with bronchial asthma (bronchial provocation test, skin test and RAST) (author's transl)].

87 patients with bronchial asthma underwent skin test, RAST and measurment of airway resistance before and after inhalation of control solution as well as at least 10 times after each of one to four bronchial provocations (making up a total of 171 tests) with extracts of house dust, house dust mite, animal dander, mould spores and pollen in increasing concentrations. An actual clinical significance of the skin test reactions was found in 60% of all cases and of the RAST results in 66% of all cases. The overall agreement between skin test results and RAST results was 61%. The correlations between the different tests depended on the degree of hypersensitivity, on the tested allergen and on whether the results of skin test and RAST, respectively, were positive or negative. There existed a good correlation between the results of all three test methods and case history only for pollen allergens and animal dander. Noticeably often negative RAST results with house dust and mould spores, as well as positive skin tests with house dust mite and mould spores could not be confirmed by the provocation test. Important indications for a bronchial provocation test in asthmatics are doubtful case history, doubtful skin test or RAST results with the problem-allergens house dust, house dust mite and mould spores; the bronchial provocation test is especially commendable when drastic or cumbersome therapeutic measures (immunotherapy, change of home, change of job) are to follow or if late asthmatic reactions are expected.

Allergens↗
PubMed1978

[Prophylaxis of immediate and delayed reactions in exogenic allergic bronchial asthma (author's transl)].

In 14 antigen provocation tests in 12 patients with allergic bronchial asthma, an immediate bronchoconstriction could be demonstrated by whole body plethysmography and a delayed reaction in 6 other cases. The examinations were repeated after a single prophylactic application of 40 mg disodium cromoglicate. By this means, 10 of the 14 immediate reactions and 4 of the 6 delayed reactions could be completely or largely prevented; in 4 and 2 patients respectively the protective effect was unsatisfactory. In longterm experiments over 4--6 months an improvement in the findings was recorded in 9 of the 12 patients. A rare side-effect of disodium cromologlicate therapy is irritation of the respiratory tract, in some cases with not inconsiderable respiratory obstruction.

Adolescent↗
PubMedDate not supplied

Indication of DNA strand breaks in human white blood cells after in vitro exposure to toluene diisocyanate (TDI).

Toluene diisocyanate (TDI), used especially for the production of polyurethanes, is known to induce chromosome aberrations, base-pair substitution, and frameshift mutation after metabolic activation. Following treatment of human blood by TDI, the isolated DNA was analyzed by anion-exchange chromatography (FPLC) before and after denaturation. In addition, DNA from white blood cells was analyzed by alkaline and neutral filter-elution and pulsed-field gel electrophoresis (PFGE). The results show that TDI induced single-and double-strand breaks in the DNA of white blood cells in vitro. The elution rate, calculated after alkaline filter elution, was significantly increased after TDI treatment. An average size of the TDI-induced DNA fragments was estimated by PFGE to be smaller than 250 kb. Denaturation and renaturation of TDI-treated DNA indicated that DNA could be cross-linked by TDI. Purified DNA treated with TDI in buffer alone does not induce DNA fragments as shown by FPLC. These findings indicate that DNA damages are induced by TDI after the biotransformation of TDI. The results show that TDI exposure induces DNA damage of white blood cells in vitro.

Adult↗
PubMedDate not supplied

Detection of protein changes in serum of workers following inhalation exposure to toluene diisocyanate vapors.

Serum samples of 10 workers undergoing occupational type inhalative challenge tests by toluene diisocyanate (TDI) were investigated by anion-exchange fast-protein-liquid-chromatography (FPLC) and polyacrylamide-gel electrophoresis (PAGE-SDS). Their serum chromatography profiles were compared to those of 20 unexposed individuals. The peak height of the first prealbumin peak in sera of workers after inhalative challenge tests was significantly different (p > 0, 01 Chi-square test) compared to that obtained before exposure and to that of unexposed subjects. In addition, qualitative changes of these peaks were also noted in sera of workers exposed to TDI. In the cases of exposed individuals, that peak was more diffuse with some shoulders and less symmetric in appearance. Similarly, PAGE-SDS of the serum proteins, followed by silver nitrate staining, revealed a different banding pattern after in vivo TDI exposure. One of the serum components at approximately 15 kDa showed an increase of staining intensity after exposure (n = 10), compared to unexposed subjects or to patients before exposure. This serum fraction has not yet been identified. The results here demonstrate that it is possible to detect changes of serum proteins in TDI-exposed individuals within a relatively short analysis time. This could be useful for biological monitoring of exposure, since no method for such is yet available.

Administration, Inhalation↗
PubMedDate not supplied

Asthma and genetics. Lecture held at Interasma 93 (Jerusalem) during the Epidemiology and Genetic Session on October 28, 1993.

Hypersensitivity to environmental allergens has increased in the last years. Several authors have described the physicochemical properties, nucleotide and amino acid sequences, and also the three-dimensional structure of unknown allergens. The aim is to identify T- and B-cell epitopes and to understand the regulatory mechanism of the excessive immune response. The induction of specific IgE antibody production in genetically predisposed subjects is the characteristic allergens have in common. New molecular biological studies indicate that, especially in monosensitized subjects, a correlation exists between the HLA-D system and the allergen-specific IgE immune response.

Allergens↗