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Biomedical subjects

X Baur

Publications and source records attributed to X Baur.

At least 199 records · Page 11Linked to original sources
PubMed1993

DNA typing with digoxigenin-11-dideoxyuridinetriphosphate-labelled oligonucleotide probes enables non-radioactive analysis using a dual detection system: application for screening HLA-DQA1 polymorphisms.

We describe a standardized, highly sensitive, nonradioactive detection procedure for HLA class-II typing of DQA1 alleles and suballeles which has important and cost-effective application in studying HLA disease associations. The procedure involves polymerase chain reaction-based target DNA sequence amplification and dot blotting followed by stringent hybridization with digoxigenin-11-dideoxyuridine triphosphate 3'-end-labelled allele-specific oligonucleotide probes. The dual detection system described here makes this procedure very versatile.

Alleles↗
PubMed1993

Pulmonary hemorrhage due to inhalation of vapor containing pyromellitic dianhydride.

Pulmonary hemorrhage due to inhalation of fumes or powders containing trimellitic anhydride (TMA) is well known. We report pulmonary hemorrhage in a young man exposed to epoxy resin vapor containing pyromellitic dianhydride (PMDA). Serum IgG antibodies to PMDA could be detected. We conclude that the pulmonary hemorrhage was mediated by a reaction to PMDA in analogy to the TMA-induced disease. We suggest that exposure to any acid anhydride should be considered a possible cause of pulmonary hemorrhage since these compounds share structural and functional similarities.

Adolescent↗
PubMed1993

[Stepwise diagnosis of respiratory latex allergy].

Latex proteins bound to the powder of latex gloves are potent aeroallergens which can cause severe immediate-type allergic reactions of the upper and lower respiratory tract. To evaluate the clinical relevance of positive skin prick tests or IgE antibodies to latex we developed a sequence of provocation tests for the diagnosis of latex induced rhinitis or asthma. 14 patients are presented, 11 working in the medical field. All had positive skin prick test to latex milk and specific IgE-antibodies to a latex glove extract, six were atopic. 14 reported symptoms of the upper respiratory tract, 11 dyspnea related to latex contact. Nasal provocation with a suspension of powder from latex gloves or a glove extract could prove latex rhinitis in all cases by rhinomanometry. Bronchial obstruction was seen in four cases with one severe asthma attack in this test. The workplace-related provocation test with latex gloves was less sensitive for latex-asthma (3/9 positive) than the direct bronchial provocation test with a latex glove extract (6/7 positive), the three latex allergic patients without a history of dyspnea remaining negative in both. Provocation tests are highly sensitive for latex allergy of the respiratory tract and therefore of special importance in the diagnostic procedure.

Adult↗
PubMed1993

[Toluene diisocyanate-induced bronchial hyperreactivity in an animal model of occupationally-induced lung diseases].

UNLABELLED: Diisocyanates, widely used in industry for the production of polyurethanes, paints and adhesives represent a growing problem in occupational medicine. Beside toxic responses, isocyanates induce sensitization of exposed workers and may cause asthmatic reactions. To study the pathomechanisms of acute isocyanate induced lung injury, we developed an animal model using anaesthetised rabbits. Inhalation of toluene diisocyanate (TDI) in the range of threshold limit value (TLV) of 10 ppb (as well as 5 and 30 ppb) four times for a period of one hour, performed in 3 groups of 8 rabbits, did not significantly alter airway resistance (R), dynamic elastance (Edyn), slope of inspiratory pressure generation (dPoes/TI), arterial pressure (Pa) or arterial blood-gas tensions (PaO2, Pa-CO2) within time of exposure. In these experiments, before and after each TDI inhalation, unspecific airway responsiveness to 2% Acetylcholine (ACH) aerosol, inhaled for 1 minute, was measured. After 4 hours of TDI-inhalation, the amplitude of the bronchoconstrictory responses to ACH rose significantly (p < 0.005) to 3.6 times of the control value. Similar changes in the amplitude of airway resistance were measured. After inhalation of 5 ppb TDI no significant changes in airway reactivity were noticed, whereas the responses were further enhanced with 30 ppb TDI. In a control group of 8 animals, not undergoing TDI inhalation, the responses of Edyn, R and delta Pöes/TI to ACH aerosol inhalation did not significantly alter from one challenge to another. CONCLUSION: Diisocyanate atmospheres of threshold limit value of 10 ppb cause bronchial hyperreactivity within 4 hours of exposure in our rabbit model of occupational lung disease.

Animals↗
PubMed1992

[Latex proteins as the trigger of respiratory and systemic allergies].

56 patients (52 members of the hospital's staff, four with other employment) who had hypersensitivity reactions to latex articles and developed an immediate-type response to latex extract with the skin-prick test were studied. Specific IgE antibodies were present in the enzyme-allergo-sorbent test of 50 of the subjects. Latex-containing surgical and household gloves were the main cause of allergies. Patients with isolated contact urticaria (n = 8) had a tendency towards lower antibody concentrations than those with additional respiratory and/or systemic symptoms (n = 48). Occupation-related provocation tests triggered rhinitis in 19, conjunctivitis in ten, and bronchial obstruction in six. The main allergen was found to be a protein with a relative molecular mass of 58,000, originating from the latex milk and passing from the latex glove into the glove powder. In the course of usual activities considerable allergen inhalation can occur. Even small amounts (e.g. 400 ng/ml) can precipitate significant allergic reactions. The results show that the main latex allergen, a glycine-rich protein molecule, can cause cutaneous, inhalant and systemic hypersensitivity reactions.

Adult↗
PubMed1992

Insect hemoglobins (Chi tI) of the diptera family Chironomidae are relevant environmental, occupational, and hobby-related allergens.

Six hundred and forty-two persons with hobby-related (n = 205), occupational (n = 85), or environmental contact (n = 352) to the midge and larval allergen Chi tI were studied. Frequencies of IgE-mediated sensitization in these selected populations were 36.1%, 24.7%, and 9.6% respectively. Occupationally sensitized subjects who had been heavily exposed showed higher levels of antibodies, were more frequently diagnosed as having bronchial asthma and less frequently as having conjunctivitis, and had a significantly shorter latency period when compared to environmentally exposed people or aquarists. Our results are evidence for a higher risk of sensitization and of bronchial asthma in highly exposed subjects.

Allergens↗
PubMed1992

Latex-specific proteins causing immediate-type cutaneous, nasal, bronchial, and systemic reactions.

We examined 70 patients reporting hypersensitivity reactions caused by latex articles. All patients suffered from urticaria, 36 from rhinitis, 31 from conjunctivitis, 22 from dyspnea, and 17 from systemic reactions, and four patients developed severe systemic complications during surgery. By means of inhalative challenge tests with powdered latex gloves, it could be demonstrated that the glove powder (cornstarch) obviously functions as a carrier for latex allergens, which then become airborne. Five of 18 patients undergoing such challenge tests demonstrated a significant increase of specific airway resistance; 17, acute rhinitis and/or conjunctivitis; and two, a systemic reaction. Sixty-two percent of the patients demonstrated specific IgE antibodies to natural latex, 58% to an irradiatively cross-linked, so-called, "hypoallergenic" latex preparation, and 46% to commercial-latex RAST disks (Pharmacia). No specific antibodies to cornstarch or a mixture of rubber chemicals were found. A good correlation (82%) exists between latex IgE RAST and latex skin prick test, as revealed in a subgroup of 45 subjects. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the latex allergen appears to be a mixture of proteins in a molecular weight range from 10 to 67 kd.

Adult↗
PubMed1992

DNA damage in human white blood cells after inhalative exposure to methylenediphenyl diisocyanate (MDI)--case report.

A workplace-related inhalative exposure test in a challenge chamber was performed on an industrial worker in a methylenediphenyl diisocyanate (MDI) atmosphere from 5 to 20 ppb and the isolated white blood cell DNA was analysed by electrophoresis, anion-exchange chromatography and melting behaviour. The results of electrophoresis indicate that inhaled MDI induces double-strand breaks of DNA. Some of the DNA fragments were estimated to be in the region of 100-500 bp. Anion-exchange chromatography confirmed this finding. Following denaturation and rapid renaturation the results demonstrated that some DNA fragments are cross-linked by MDI. Comparing the melting curves before and after inhalative exposure in the challenge test chamber, genomic DNA revealed differences in the shape of the melting curve (hyperchromic effect). The results suggest that occupational MDI exposure could be associated with white blood cell DNA damage.

Administration, Inhalation↗
PubMed1992

A novel HLA-haplotype containing a DRB5 gene not associated with DRB1*15 or DRB1*16 alleles.

In Caucasians, HLA-DR2 haplotypes usually express two DRB genes encoding the DR specificity. The DRB5 genes are in strong linkage disequilibrium with the respective DRB1*15 or DRB1*16 alleles. So far, no other DRB1 alleles have been found in association with DRB5 genes. Here, we report evidence for a probably recombinant DRB5 haplotype with a DRB1 allele not specific for DR2. From our results the haplotype DQB1*0501, DRB1*0101 and DRB5*0101 seems most likely.

Adult↗
PubMed1992

Increased prevalence of IgG-induced sensitization and hypersensitivity pneumonitis (humidifier lung) in nonsmokers exposed to aerosols of a contaminated air conditioner.

Specific IgG antibodies against antigens of a contaminated air conditioner were estimated in serum of 134 workers of a printing company. Altogether 64% of the workers investigated revealed significantly elevated levels (> 3 U/ml) of IgG antibodies specific to these antigens as compared to a nonexposed control group. The occurrence of IgG antibodies for microbial extracts were 25% for Fusarium, 23% for Penicillium notatum, 13% for Alternaria tenuis, 12% for Aureobasidium pullulans, 9% for Sphaeropsidales species, 3% for Micropolyspora faeni, 2% for Aspergillus fumigatus and 2% for Thermoactionomyces vulgaris. Out of the 86 workers with elevated IgG antibodies for air conditioner antigens, 59 were nonsmokers. Considering a cut-off level of 10 U/ml IgG for high values, the proportion of smokers to nonsmokers becomes even more pronounced (6 to 36 respectively, binominal test p < 0.001). This is despite the fact that the distribution of smokers and nonsmokers among the 134 workers is approximately equal (60 to 74). All 3 workers with clinical diagnosis of humidifier lung or humidifier fever belonged to the nonsmoker group. Our findings indicate that crude water extracts of contaminated air conditioners are the best choice as antigen source for the diagnosis of humidifier lung in exposed workers. Nonsmokers are shown to have a high risk for immunological sensitization.

Aerosols↗
PubMed1992

[Exogenous allergic alveolitis caused by mouldy hazel nut leaves].

A 62-year old farmer woman from the northeastern, very rainy part of Turkey has been collecting large amounts of green and brown involucral hazel-nut leaves for subsequent use as fuel. For the last 20 years she had been complaining of cough, respiratory distress and intermittent fever. In the course of years of continual antigen exposure she developed the clinical and x-ray signs of fibrosis of the lung. Bronchoalveolar lavage produced the typical cell pattern of chronic exogenous allergic alveolitis with predominant CD8 cells. Serum analysis yielded high titres of IgG antibodies against mould fungi partly obtained from hazel-nut husk cultures, as well as thermophilic actinomycetes.

Actinomycetales↗
PubMed1992

Chironomid midge allergy.

Chironomidae larvae and midges cause allergic reactions in approximately 20 percent of exposed people; predominantly aquarists using insect larvae as fish food and environmentally exposed subjects living in areas abounding in water are affected. Our studies include 642 subjects of whom 205 are aquarists; 85 are occupationally and 352 environmentally exposed people. 123 of them were shown to be sensitized to these insects. Using highly purified allergens, we could demonstrate that Chironomidae hemoglobins (Chi t I) represent the major allergenic components causing rhinitis, conjunctivitis and bronchial asthma. Considerable immunological cross-reactivity exists between hemoglobins of the same and closely related Chironomidae species. Genetic factors seem to be important for the susceptibility of this type of allergy. In studies with peptides of Chi t I component III, we identified several epitopes recognized by human IgE antibodies and/or T-cells.

Allergens↗
PubMed1992

[Is hyposensitization still an adequate procedure in treatment of bronchial asthma?].

Hyposensitization of asthmatic patients is still an open and controversially discussed question. An own randomized, single-blind study including 39 patients who were controlled twice at one year intervals by bronchial allergen challenges is demonstrated. Hyposensitization resulted in a decrease of the number of late asthmatic reactions whereas placebo was associated with an increase of this type of reaction. On the other hand only placebo induced an elevation of the specific bronchial threshold dosage for allergens, e.g. the asthma-inducing or tolerated allergen load increased by 13 to 36% (p greater than 0.005). These results which are in agreement with experiences especially of anglo-saxon authors, severe side effects in some cases as well as the improvement obtained by topic corticosteroids and mast cell stabilizers reveal hyposensitization not to be the treatment of choice for asthmatic patients.

Adolescent↗
PubMed1991

[Aquarium--when hobby becomes a danger. A case report].

In this case report, allergic rhinitis and episodes of asthma triggered by the hemoglobin of the red mosquito larva used as fish food are described. After three years of contact and an allergic condition persisting for three months, skin testing and IgE determination revealed moderate sensitization of the immediate reaction type. When contact with the allergen was stopped, the symptoms abated immediately.

Adult↗