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Biomedical subjects

G Curiel

Publications and source records attributed to G Curiel.

9 recordsLinked to original sources
PubMed1998

Cereal alpha-amylase inhibitors cause occupational sensitization in the wood industry.

BACKGROUND: Cereal flours are used in the wood industry to improve the quality of the glues necessary to produce veneer panels. However, up to now, no cases of sensitization to cereal flour in this kind of industry have been reported. Cereal alpha-amylase inhibitors have been previously described as important occupational allergens responsible for baker's asthma. OBJECTIVE: To determine whether cereal allergens were responsible for occupational sensitization in three wood industry workers. METHODS: The diagnosis was made by clinical questionnaire, physical examination, skin-prick tests to cereals, CAP and immunoblotting. RESULTS: The three patients had positive skin prick tests and CAP to cereal flours. An IgE-immunoblotting revealed that only low molecular weight proteins (under 20 kDa) were detected by the three sera. These main IgE-binding proteins were members of the alpha-amylase inhibitor family which have been described as one of the group of main allergenic proteins in rye, barley and wheat. The three patients changed their workplace and remain asymptomatic in spite of the fact that they are still in contact with different woods and exposed to high concentrations of wood dust and other chemicals such as formaldehyde. CONCLUSION: Proteins from cereal flours are important occupational allergens in some wood industries.

Adhesives↗
PubMed1997

Periodate treatment of Anisakis simplex allergens.

Anaphylactic reactions after parasitized fish consumption are mediated by an IgE response. However, positive skin tests and specific IgE can also be found in many asymptomatic subjects who recognize a single medium-mol.-wt. antigen by IgE immunoblot. The study aimed to find out whether this unspecificity was due to the carbohydrate moieties of parasite antigens. Sixty-two patients with suspected parasite allergy, 51 blood donors, 18 bakers, and 38 atopic patients were studied by blotting. Parasite proteins were treated with periodate. Several selected sera were inhibited with a crude wheat extract and fungal amylase. Twelve patients (19%), eight donors (16%), six bakers (33%), and one atopic patient (3%) recognized a single medium-mol.-wt. band in blotting and should be considered false-positive. This band was periodate-sensitive, but specific IgE to this allergen could not be inhibited by a wheat extract nor by fungal amylase and was clinically irrelevant. Diagnosis of Anisakis simplex hypersensitivity by skin tests and/ or specific IgE values should always be confirmed by specific IgE immunoblotting in order to detect the presence of clinically unrelated antibodies directed to periodate-sensitive allergens. These allergens are probably not a carbohydrate moiety of a parasite glycoprotein.

Amylases↗
PubMed1996

Hypersensitivity to carrot associated with specific IgE to grass and tree pollens.

This study deals with a 34-year-old female cook with no previous history of atopy, who was studied because of allergic rhinoconjunctivitis and contact urticaria in both hands associated with severe itching when she handled raw carrot. The patient had had anaphylactic episodes after accidental ingestion of raw carrots, but she tolerated cooked carrots. Skin prick tests with carrot, celery, and olive, and birch, grass, and mugwort pollens were positive. Total IgE was 411 UI/ml. Specific IgE to olive, grass, and weed pollens were 10.92, 6.17, and 2.4 AU/ml, respectively. The histamine release test was positive for carrot, celery, celeriac, and olive pollen up to a dilution of 1/10(6). Immunoblot of raw carrot showed a single IgE-binding 18-kDa band. IgE reactivity for raw carrot immunoblot was completely inhibited by carrot and by celery, but not by olive or grass pollens. Specific IgE to olive pollen was not inhibited by carrot. The existence of monosensitization to an 18-kDa protein in carrot and specific IgE to olive pollen has not been reported in the celery-carrot-mugwort-spice syndrome.

Adult↗
PubMed1995

Skin-prick tests for hypersensitivity to alpha-amylase preparations.

Twenty-five asthmatic subjects with suspected alpha-amylase hypersensitivity were studied by skin-prick tests, a capture ELISA, immunoblotting and bronchial provocation tests. At the same time, different amylases were analysed by SDS-PAGE and immunoblotting using a polyclonal rabbit antiserum. Eight patients showed a positive bronchial response to amylase. Seven of them had positive skin-prick tests, with this method being the most sensitive approach for diagnosis. However, in four cases, skin tests were also positive although the patients had a negative provocation test, thus demonstrating that skin tests are not specific. ELISA and blotting showed similar results in terms of sensitivity and specificity. The enzymes used by the workers included several antigens besides alpha-amylase. The rabbit antiserum to alpha-amylase detected a protein in a wheat flour extract. In one case, the IgE antibodies were specific only for a contaminant of lower molecular weight than amylase. These facts suggest that proteins from the culture medium could be responsible for some cases of amylase hypersensitivity, making the diagnosis difficult. The presence of amylase in another enzymatic extract, a protease produced by Aspergillus oryzae, was proved by means of skin tests and immunoblotting, thus demonstrating the allergenic properties of this enzymatic preparation.

Asthma↗
PubMed1995

Characterization of latex and chestnut antigens by immunoblotting.

BACKGROUND: Cross-reactions between latex, chestnut, and other fruits have been demonstrated by RAST, although the results show some discrepancies. OBJECTIVE: To detect and characterize cross-reacting antigens in both extracts by immunoblotting. METHODS: Polyclonal rabbit antisera were raised against ammoniated latex and an aqueous chestnut extract. The antigenic extracts were studied by immunoblotting using a diffusion transfer method. Cross-reactivities were measured by immunoblotting inhibition. RESULTS: Both antisera detected a high number of antigenic proteins in both latex and chestnut extracts. Latex was a good self-inhibitor and inhibitor of chestnut with respect to both antisera. Chestnut was only a good inhibitor for the two antisera on the chestnut-blot as well as on the latex-blot when the anti-chestnut antiserum was employed. No inhibition was obtained on latex immunoblotting by chestnut using anti-latex antiserum. CONCLUSIONS: The results suggested that latex and chestnut contained common epitopes detected by antibodies raised by immunization with both antigens. The anti-latex antiserum, however, possessed antibodies that could not be inhibited by other allergens. This could explain why latex has been described as a good inhibitor of chestnut-RAST while no inhibition by chestnut was found on the latex-RAST in latex and chestnut allergic patients. Other common pollen extracts were also inhibitors of immunoblotting with the exception of the latex/anti-latex pair. This suggests that antibodies induced by immunization with latex or chestnut showed unexpected cross-reactions.

Animals↗
PubMed1994

alpha-Amylase hypersensitivity in non-exposed millers.

Occupational hypersensitivity to alpha-amylase among bakers and workers in the pharmaceutical industry has been described. We present the results of skin tests and in vitro methods used to assess alpha-amylase sensitivity in 259 millers. There was no occupational contact with the enzyme in this population. Positive skin tests to this allergen were obtained in 16 subjects (6.18 per cent), specific IgE values were found in seven subjects (2.7 per cent), specific IgG was detected on 45 workers (17.37 per cent) and high values for IgG (> 2.5 absorbance units) were found in 12 subjects (4.63 per cent). Furthermore, specific IgE and IgG could be determined in several sera by immunoblotting. All these facts suggested that millers were sensitized to Aspergillus oryzae alpha-amylase, although the allergen was not used by these workers. A cross-reaction cannot be excluded; however, it is the authors' opinion that wheat or wheat flour is a natural substrate for fungi and that the moulds that grow on cereals or cereal-derived by-products need to secrete amylases to support their own development. Hence the workers may be indirectly sensitized to amylases.

Aspergillus oryzae↗
PubMedDate not supplied

Occupational asthma caused by Papaver somniferum.

Twenty eight workers of a pharmaceutical factory were studied. The company produced morphine and other alkaloids extracting the active principles from shells of Papaver somniferum. Six of the exposed subjects had clinical symptoms of sensitization to this allergen and positive skin tests. A bronchial provocation test was found to be positive on 4 workers and specific IgE could be found on the 6 sensitized patients by an ELISA and a RAST test using an aqueous extract of P. somniferum. A histamine release using the same antigen was also positive in the 4 samples from sensitized patients available. An SDS-PAGE of the extract revealed a major protein band with an estimated mol wt of 52,000 d. This band had the highest IgE-binding capacity as shown by immunoblotting. All these facts suggest that P. somniferum allergy is mediated by an IgE mediated mechanism and not by a pharmacological or toxic effect of the alkaloids or polyphenols.

Allergens↗