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J C Orta

Publications and source records attributed to J C Orta.

7 recordsLinked to original sources
PubMed2000

Prevalence of sensitization to Tetranychus urticae in greenhouse workers.

BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which infests a large number of plants of economic interest worldwide. It has recently been described as a cause of occupational allergic disease in greenhouse workers. However, there are no epidemiological data concerning the prevalence of TU allergy in an unselected exposed population. OBJECTIVE: The aims were to study the prevalence of TU sensitization among greenhouse workers and its relationship to the working environment and to personal factors. METHODS: We studied 246 consecutive greenhouse workers, recruited directly from the field. A clinical and epidemiological questionnaire, a skin-prick test (SPT) to TU and common allergens and TU-specific IgE (RAST) determinations were performed. Seventy-five healthy volunteers and 152 atopic patients were used as a control group. RESULTS: The prevalence of a positive SPT to TU was of 25%. Forty-five workers (19%) were TU-allergic, occurring more often in atopic greenhouse workers (P < 0.0001). Seven per cent showed asymptomatic sensitization. The time of exposure to TU was significantly greater in the TU-allergic patients (P < 0.05). The probability of sensitization to TU was 3.7 times greater in exposed than in non-exposed subjects (P < 0.0001). CONCLUSIONS: In this study, the prevalence of TU sensitization was 25%. There were significant associations with TU allergy and atopy and the time of exposure to TU.

Adult↗
PubMed1997

Occupational allergy in greenhouse workers: sensitization to Tetranychus urticae.

BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which is found infesting a large number of plants of economic interest. It has rarely been described as a cause of occupational allergic disease in agricultural workers. OBJECTIVE: To describe TU sensitization in greenhouse workers attending the outpatient allergy unit and its clinical associations, and to characterize the allergens involved. MATERIALS AND METHODS: Twenty-four consecutive carnation greenhouse workers with allergy-related symptoms, referred to our outpatient clinic during a 6-month period, were included. We made the diagnostic extract from carnation leaves heavily infested with TU. Skin-prick test, specific IgE measurement and bronchial provocation test with TU extract were carried out in all subjects. Allergen characterization was achieved by SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis) and immunoblotting. RESULTS: Sixteen patients (66%) presented positive skin-prick test and specific IgE and were diagnosed allergic to TU. Fifteen patients suffered from bronchial asthma, 14 rhinitis and five urticaria. Twelve exhibited positive bronchial provocation test to the TU extract. On RAST-inhibition studies, there was no evidence of crossreactivity between TU extract and D. pteronyssinus. An allergen at 19 kDa was determined in the TU extract by SDS-PAGE immunoblotting studies. CONCLUSION: TU could be an important occupational allergen in greenhouse workers showing allergic symptomatology. There is no crossreactivity between this mite and the house dust mite D. pteronyssinus.

Adolescent↗
PubMed1991

[Endogenous digitalis].

During the past 10 years, several groups of researchers from different laboratories have carried out research on an endogenous substance or substances which had cross immunoreacted to digoxin antibodies in patients without previous cardiotonic treatment. The increase has been demonstrated in various clinical cases which involve an augmentation of plasmatic volume. A considerable amount is known about its molecular structure and anatomic origin; the competitive inhibition of the sodium pump being quite clear.

Animals↗
PubMedDate not supplied

Comparative allergenic study of Tetranychus urticae from different sources.

Tetranychus urticae is a macroscopic mite known as "red spider mite". It is a cosmopolitan and polyphagous mite which parasitizes both fruit trees and herbaceous plants, particularly in greenhouses. Contribution of T. urticae to occupational asthma among greenhouse workers has been studied to identify and describe the main T. urticae allergens. In this study we described and compared the physiochemical characteristics of the main. T. urticae allergens from three different sources, carnation, cucumber and vegetable marrow. Forty-two green-house workers with occupational T. urticae allergy were included. Extracts were prepared from mite bodies collected from the three different sources; skin prick tests, specific IgE, SDS-PAGE and SDS-PAGE immunoblotting were carried out with the three T. urticae extracts. Cross-reactivity was measured by RAST inhibition. These assays were done with each of the three extracts in solid and fluid phases. All patients showed a positive prick test to T. urticae extracts from carnation, 39 (93%) to those from cucumber, and 34 (81%) to those from vegetable marrow. Specific IgE was positive in 80% of patient sera from T. urticae extract from carnation, 58% and 63% in that from cucumber and vegetable marrow, respectively. SDS-PAGE immunoblotting of the extracts showed coincident and relevant allergens. The similar curve obtained by RAST inhibition assays revealed the high epitope similarity from the three extracts. In conclusion, T. urticae extracts from parasitic carnation, cucumber and vegetable marrow cultures showed a high epitope similarity with three relevant allergens with molecular mass of 25, 19 and 15 to 17 kDa.

Adolescent↗