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Biomedical subjects

X Baur

Publications and source records attributed to X Baur.

At least 181 records · Page 10Linked to original sources
PubMed1994

Allergens causing bird fancier's asthma.

The study investigates to what extent bird feathers contain relevant allergens/antigens involved in bird fancier's asthma. The study group consisted of two budgerigar fanciers, two parrot fanciers and one canary fancier. All subjects complained of asthmatic symptoms, caused by contact with their birds, and they showed a significant bronchial hyperreactivity to acetylcholine. Positive IgE antibody reactions to bird sera as well as to extracts of feathers were observed in RAST. Well-defined major allergenic bands could be detected and identified in the IgE immunoblots with feather extracts as well as with serum proteins of budgerigar, parrot, pigeon, canary, and hen (mol. mass 20-30 kDa and 67 kDa). The most pronounced bands appeared with the extracts of species to which an exposure had taken place. Weaker IgG-binding patterns were also observed. Our results show that inhalable feather dust contains several allergenic components which cross-react with serum allergens/antigens of the same as well as of other bird species. This emphasizes the significance of bird feathers for immediate-type allergic reactions.

Adult↗
PubMed1994

Acute autoimmune response in a case of pyromellitic acid dianhydride-induced hemorrhagic alveolitis.

A 17-year-old man was occupationally exposed to pyromellitic acid dianhydride dust during the production of epoxy resin in a chemical factory. He was clinically diagnosed as having acute hemorrhagic alveolitis associated with anemia. The serologic analysis revealed a high concentration of IgG antibodies against pyromellitic acid dianhydride-treated human serum albumin (PMDA-HSA). Immunoblotting with PMDA-treated human serum as antigen and the patient's serum as the first antibody showed that additional PMDA-modified serum proteins other than HSA were recognized by the patient's IgG antibodies in the higher mol. mass range (> 67 kDa). No specific IgG could be detected against other anhydride conjugates (maleic acid, MA; phthalic acid, PA) with the exception of a reaction with the trimellitic acid anhydride-conjugated HSA (TMA-HSA). No specific IgE antibodies could be detected against any of the above mentioned antigens, but immunoblotting of the patient's serum indicated IgG4-type autoantibodies against in vitro PMDA-treated Ig molecules of normal serum proteins.

Acute Disease↗
PubMed1994

Polymerase chain reaction based cDNA cloning of wheat profilin: a potential plant allergen.

Highly degenerate profilin-specific primers were used to amplify by polymerase chain reaction the profilin-coding sequence of wheat cDNA. Analyzing the sequencing data after subcloning revealed the existence of three isoforms. The high amino acid sequence identity with the birch pollen allergen Betv II suggests that wheat profilin may be a potential plant allergen, relevant in food allergy.

Allergens↗
PubMed1994

Increased incidence of DNA double-strand breaks and anti-ds DNA antibodies in blood of workers occupationally exposed to asbestos.

Asbestos, proven to be carcinogenic in humans and animals, is reported to have no genotoxic effect. Asbestos workers have an increased risk of lung cancer, mesothelioma, and other tumours. Earlier findings showed that crocidolite can induce DNA strand breaks in cultured rat embryo cells as assessed by nick translation. We investigated DNA double-strand breaks in white blood cells (WBC) of ten workers occupationally exposed to asbestos. According to our results, obtained with neutral filter elution, individuals who had been exposed to asbestos fibres showed two to four times more DNA double-strand breaks (dsb) in white blood cells than ten non-exposed persons. The induced DNA fragments are of about 250 kb (compared to chromosomal DNA of Saccharomyces cerevisiae standard marker). Using additionally the chromosomal DNA protective method of agarose-plugs, DNA fragments in the range of 200 to 1000 kb have been found in the white blood cells of the same ten workers occupationally exposed to asbestos. In the white blood cells of non-exposed subjects no DNA fragments could be detected with this method. Compared to 51 non-exposed persons, elevated anti-ds DNA antibody concentrations were found in ten workers occupationally exposed to asbestos. The fact that workers occupationally exposed to asbestos have distinctly more double-strand breaks and anti-ds DNA antibodies could mean that an increased incidence of DNA-fragments may be an important indicator in the chronic effect of asbestos-associated carcinogenesis. Apparently, the chronic effects of asbestos observed here do not seem to be identical with that of previously reported acute in vitro effects.

Adult↗
PubMed1994

Increased gamma/delta-positive T-cells in blood and bronchoalveolar lavage of patients with sarcoidosis and hypersensitivity pneumonitis.

A small population of T-cells does not express the conventional T-cell receptor (TCR), characterized by the alpha and beta polypeptide chains (alpha/beta TCR) but two polypeptides termed gamma and delta (gamma/delta TCR). Changes in gamma/delta TCR expression may be relevant as the cause or consequence of several diseases. Our study was undertaken to determine and compare the distribution of T-cells expressing gamma/delta TCR in blood and bronchoalveolar lavage (BAL) of patients with sarcoidosis, hypersensitivity pneumonitis (HP), idiopathic pulmonary fibrosis (IPF), and of healthy controls. In addition, the association between gamma/delta TCR of blood T-lymphocytes and accessory molecules was analysed. Using direct immunofluorescence with the anti-gamma/delta TCR and anti-CD3 monoclonal antibodies (MoAbs) followed by flow cytometric analysis, the blood of patients with pulmonary sarcoidosis, HP, IPF and of healthy controls was analysed. To reveal the association between gamma/delta TCR of blood T-lymphocytes and the accessory molecules, expression of CD4, CD8 and CD25 were determined. Calculating the percentage and the total number of CD3+ gamma/delta TCR cells in blood, the data indicated a significant increase of gamma/delta T-cells in individuals with pulmonary sarcoidosis and HP, compared to healthy controls and IPF patients. In sarcoidosis patients with elevated CD3+ gamma/delta TCR levels, significantly lower CD4/CD8 ratios were observed. In addition, our data demonstrate a correlation between the decrease of CD4+ cells in blood and the amplified appearance of gamma/delta TCR expression in sarcoidosis patients, but not in HP patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Bronchopulmonary precancerous conditions and tumors--risk groups from the occupational medicine viewpoint].

Risk groups with regard to bronchopulmonary precancerous and tumor diseases of occupational origin can be deduced from current occupational disease statistics. Most prominent are those working with asbestos. Each year about 250 asbestos-associated bronchial carcinomas and 400 mesotheliomas are recognized and compensated; the tendency is increasing. Because of the long latency time, the frequency peak will probably be reached in about 15 years in spite of the prohibition of asbestos usage. The second place is probably taken by malignomas among the underground uranium mine workers in Thuringia and Saxony (SDAG Wismut). Next come bronchial carcinomas with silicosis (carcinoma in scar tissue) after exposure to chromium(VI) and arsenic compounds as well as various other chemicals and metals. Dose-activity relationships are significant for all occupational carcinogenic agents, as there are also often syncancerogenic influences (especially smoking). From the data on previous loading, high risk groups, for example, among the insulation workers exposed to asbestos or uranium miners in the so-called "wild years", can be defined. A suitable screening method for the detection of bronchopulmonary tumors in the early stages has not yet been established. Medical checkups for the respective risk groups concentrate on the early X-ray detection of circular foci. As shown by recent studies, cytological sputum diagnosis, (fluorescence) bronchoscopy, and BAL cytology must be employed much more frequently in the high risk groups so that the prognostically more favorable stages of preneoplasm and carcinoma in situ can be detected and possibly treated curatively. These procedures are currently reaching a considerably higher sensitivity with the help of modern molecular biology techniques (e.g. detection of tumor-associated genetic changes and gene products). This contributes to an improvement in surveillance examinations with increasing detection of the curable early forms of tumors. However, only the further development of primary prevention, i.e. the greatest possible minimization or, if possible, total elimination of contact with carcinogenic agents and the consequent control of occupational protection will lead to a drastic reduction in the occupational risk of cancer.

Carcinoma, Bronchogenic↗
PubMed1994

[Nonspecific inhalative provocation in the sheep as an asthma model--correlation of respiratory and cardiovascular effects].

Respiratory responses after inhalative challenge tests using methacholine (MCH) are intensively investigated and described in the literature. There is however a considerable lack of knowledge about the correlation of bronchoconstrictory responses to cardiovascular changes like pulmonary arterial pressure or blood gas tensions after unspecific challenges with methacholine or with specific allergens. Ten yearling sheep inhaled MCH-aerosols in increasing concentrations of 0.5, 1.0, 2.0, 5.0 and 10% for one minute respectively in 15 minutes intervals. Airway resistance (RI), dynamic elastance (Edyn) were measured along with systemic and pulmonary artery pressure. Transcutaneously measured oxygen partial pressure (PtcO2) was recorded and correlated to arterial blood gas samples. Mean threshold concentrations of MCH for changes in RI and Edyn were found at 0.9% and for PC100 of 2.2% MCH. Bronchoconstriction was detected with a latency of 30-40 s. Maximum responses occurred after 2-5 min (p < 0.0005) after onset of the challenge. Within 15 minutes, baseline values were almost reached. While mean inspiratory air-flow remained almost unaltered, increased airway resistance and work of breathing was compensated by an increased transpulmonary pressure. A decrease in tidal volume and a rise in respiratory frequency left ventilation almost unaltered. MCH-challenge results in insignificant changes in systemic arterial pressure, while pulmonary arterial pressure increased by more than 50% of the basic value. Arterial PO2 decreased by more than 20 mmHg and was closely correlated to transcutaneously measured O2-pressure (e = 0.93). However, PaCO2 did not increase significantly. (ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1993

Health risk in hospitals through airborne allergens for patients presensitised to latex.

Two nurses had to stop practicing because of severe work-related allergic respiratory or systemic symptoms. Both developed similar symptoms within a short time when they attended hospitals as outpatients or visitors or consulted a doctor or dentist, even when they had no direct contact with latex articles. The airborne latex allergen concentration in one room that induced symptoms was 128 ng per m3. In skinprick tests both women showed positive reactions to the phosphated cornstarch powder used to prevent latex gloves sticking together, but only when the powder had been in contact with latex. This powder seems a likely vehicle for the airborne latex allergen.

Adult↗
PubMed1993

Occupational-type exposure tests and bronchoalveolar lavage analyses in two patients with byssinosis and two asymptomatic cotton workers.

Two workers suffering from stage III byssinosis and claiming for compensation were examined. Bronchial obstruction was present in one case. MEF25-75 values were significantly reduced and bronchial hyperreactivity was present in both subjects. Occupational-type exposure tests with cotton dust resulted in significant decreases in arterial oxygen pressure for more than 2 h and were associated with an obstructive ventilation pattern in one of the patients. Prolonged hypoxemia which is not paralleled by lung function changes is probably typical for byssinosis patients since we have never seen this in inhalative challenge tests with various environmental antigens and other occupational substances including flour dust. No specific IgE or IgG antibodies could be detected. In the two patients a hitherto unknown significant increase in CD23+ lymphocytes and granulocytosis were detected by bronchoalveolar lavage (BAL). Corresponding investigations in two cotton workers without any evidence of byssinosis revealed neither lung function changes after the exposure test nor striking BAL findings. Our results demonstrate the diagnostic value of specific challenge tests and BAL investigations in patients suffering from byssinosis, which is often difficult to diagnose.

Adult↗
PubMed1993

The rubber elongation factor of rubber trees (Hevea brasiliensis) is the major allergen in latex.

BACKGROUND: Allergy to latex-containing articles is becoming more and more important because it can result in unexpected life-threatening anaphylactic reactions in sensitized individuals. METHODS: A protein of 58 kd with an isoelectric point of 8.45 was purified from raw latex and from latex gloves and identified as the major allergen, completely blocking specific IgE antibodies in the serum of latex-sensitized subjects. The allergen is a noncovalent homotetramer molecule, in which the 14.6 kd monomer was identified, by amino acid composition and sequence homologies of tryptic peptides, to be the rubber elongation factor found in natural latex of the Malaysian rubber tree. RESULTS: Competitive immunoinhibition tests showed that the starch powder covering the finished gloves is the airborne carrier of the allergen, resulting in bronchial asthma on inhalation. The purified allergen can induce allergic reactions in the nanogram range. CONCLUSION: The identification of the allergen (Hev b I) may help to eliminate it during the production of latex-based articles in the future.

Allergens↗
PubMed1993

Epitope mapping with peptides of Chi t I component III and immunomodulation of the Chi t immune response.

BACKGROUND: Hemoglobins of the Diptera family are known as aggressive inhalant allergens. METHODS: The whole sequence of the insect allergen Chi t I component III was studied for T-cell epitope activity in cell cultures of 15 sensitized patients with a panel of 17 overlapping synthetic peptides and 12 peptides obtained by tryptic cleavage. RESULTS: All but one of the peptides tested were found to be immunogenic. The nonstimulatory sequence 102-109 and two other tryptic peptides (69-90 and 110-135) were used in inhibition experiments. The Chi t I-induced proliferation was downregulated by all tested peptides when compared with stimulation with Chi t I alone. CONCLUSIONS: Because stimulation with phytohemagglutinin or tetanus toxoid was not influenced by the above-mentioned peptides, this mechanism seems to be specific for the antigen. Specific immunomodulation with nonstimulating peptides may offer new therapy approaches.

Adjuvants, Immunologic↗
PubMed1993

Increased incidence of anti-dsDNA autoantibody concentration in sera of workers occupationally exposed to diisocyanates.

Sera of 87 industrial workers with a history of occupational exposition to various diisocyanates, toluene diisocyanate, hexamethylene diisocyanate and methylene-diphenyl diisocyanate were analyzed for antibodies to isocyanate-conjugated human serum albumin and for anti-dsDNA autoantibodies. Ten workers (approx. 11%) were shown to have elevated anti-dsDNA autoantibody concentrations and 13 revealed antibodies to isocyanate-modified human serum albumin. The overlap of both tests being positive was calculated at about 40%. It would seem, therefore, that routine estimation of anti-dsDNA autoantibodies could provide additional useful information for the clinical diagnosis of occupational health impairment due to isocyanate exposure.

Adult↗
PubMed1993

Humoral immune response to the insect allergen Chi t I in aquarists and fish-food factory workers.

Our examination of 225 subjects who had been exposed to the insect allergen Chi t I involved the degree of allergen exposure, the exposure-associated symptoms, and their relationship to the presence of specific IgE and IgG antibodies as well as sensitization to ubiquitous allergens. It could be shown that specific IgE antibodies found in 34% of these subjects were closely associated with symptoms (P < 0.01), whereas no relationship between IgG antibodies and complaints could be observed. Conjunctivitis (63%) and rhinitis (62%) were predominant, followed by asthma (45%) and urticaria (37%). Antibody levels of patients suffering from asthma were highest. In addition, symptoms were associated with the degree of exposure. While nearly all IgE-sensitized subjects of the medium-, high-, and very high-exposure group were symptomatic, only 57% of the sensitized individuals of the low-exposure group reported complaints. Furthermore, specific IgE antibodies were most frequently present in the groups with medium (46%) and high (54.5%) exposure, whereas IgG antibodies predominated in individuals with very high exposure (69.1%). In the low-exposure group, most subjects (73.6%) had neither IgE nor IgG antibodies. In addition, within Chi t I sensitized subjects, sensitization to common allergens and elevated total IgE levels were more frequently present than within non-Chi t I sensitized individuals, indicating a predisposition to allergy.

Allergens↗
PubMed1993

Immediate allergic and nonallergic reactivity of the airways in Ascaris skin-sensitive sheep.

Immediate airway reactivity to Ascaris suum allergen was compared with the responses to nonallergic airway challenge using histamine and acetylcholine in sheep with positive skin reactions to the allergen. In a control group of 6 sheep with negative skin test responses, allergen aerosol inhalation and allergen extract infusion only caused minor changes in mechanics of breathing as well as in arterial plasma histamine concentration. Nearly 40% of the animals with a positive skin test responded to allergen inhalation with an acute airway obstruction, whereas all animals bronchoconstricted after allergen infusion. Bronchoconstriction was associated with an increase in arterial plasma histamine concentrations. The difference between the two groups of skin test-positive sheep seems to be due to the amount of histamine liberation after allergen exposure. Allergen infusion caused a more severe increase of airway resistance and plasma histamine levels in animals responding to allergen inhalation than in animals responding to allergen infusion only. Similar responses were obtained in both groups after inhalation and infusion of histamine and acetylcholine. Since the slope of the responses (dEdyn/dHi.Pl.) was similar in both groups of animals we conclude that the sensitivity of receptors is similar in responders to allergen inhalation and in animals responding to allergen infusion only.

Acetylcholine↗