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Biomedical subjects

J A Ojeda

Publications and source records attributed to J A Ojeda.

At least 19 recordsLinked to original sources
PubMed1997

IgE crossreactivity between mugwort pollen (Artemisia vulgaris) and hazelnut (Abellana nux) in sera from patients with sensitivity to both extracts.

BACKGROUND: An association between sensitization to Compositae pollens and hypersensitivity to hazelnut has been previously described. There is no previous in vitro study about crossreactivity between mugwort pollen and hazelnut. OBJECTIVES: To study mugwort pollen and hazelnut allergens and to assess if there is IgE crossreactivity between mugwort pollen and hazelnut. METHODS: A serum pool formed by 28 individual sera with specific IgE to mugwort pollen and hazelnut was used to investigate IgE crossreactivity. RAST-inhibition, SDS-PAGE/IEF immunoblotting inhibition assays were performed by preincubation of the sera with mugwort pollen and hazelnut. RESULTS: RAST to hazelnut was inhibited up to 63% by mugwort pollen, but the mugwort pollen RAST was only inhibited up to 36% by hazelnut. In SDS-PAGE immunoblotting mugwort pollen showed nine allergens ranging from <16 to 65 kDa and hazelnut had four main allergens: 42 kDa, 17 kDa and <16 kDa (two bands). In the SDS-PAGE immunoblotting inhibition hazelnut partially inhibited all the mugwort pollen bands, except that with 19kDa, whereas mugwort pollen produced a nearly total inhibition of all the hazelnut allergens. In isoelectrofocusing immunoblotting mugwort pollen had two groups of allergens: pI 7.5-8.5 and pI 3.5-5.2 and hazelnut one group of allergens: pI 5.2-5.8. In the isoelectrofocusing immunoblotting inhibition hazelnut produced a partial inhibition of all the bands of mugwort pollen and mugwort pollen partially inhibited all the allergenic bands of hazelnut. CONCLUSIONS: The RAST and SDS-PAGE/IEF immunoblotting inhibition results provide evidence of IgE cross reactivity between mugwort pollen and hazelnut allergens. The inhibition of hazelnut by mugwort pollen is higher than the inhibition of mugwort pollen by hazelnut in both RAST inhibition and SDS-PAGE immunoblotting inhibition. These results suggest that mugwort pollen allergens would behave as primary immunogens in the association between sensitivity to mugwort pollen and hazelnut.

Allergens↗
PubMed1995

Cross-reactivity of IgE-binding components between boiled Atlantic shrimp and German cockroach.

IgE-antibody reactivity to boiled Atlantic shrimp (Pandalus borealis) and German cockroach (Blattella germanica) of sera from 89 patients, sensitive to one or the other, was investigated with an enzymatic immunoassay for specific IgE detection (CAP-FEIA System, Pharmacia, Sweden). IgE serum levels to both antishrimp and anticockroach allergens were found to be positive in 76 of the 89 (85.4%) tested sera. A positive anticockroach IgE was very rare in the absence of detectable antishrimp IgE (five of 89 sera). Linear regression analysis on antishrimp and anti-German cockroach IgE levels-log plot revealed a correlation coefficient (r) of 0.73. Inhibition experiments showed that boiled Atlantic shrimp extract inhibited CAP with German cockroach, and vice versa. Immunoblotting showed the strongest IgE binding for both allergenic extracts between 30 and 43 kDa. By blot inhibition, the binding capacity of German cockroach was totally abolished by Atlantic shrimp extract, while German cockroach extract only partially IgE binding to Atlantic shrimp. Cross-reactivity exists between shrimp, an important food allergen, and German cockroach, which has an increasing role in allergic asthma. It could be important to determine the clinical significance of cross-allergy to both allergens, in which exposures occur in different ways.

Adolescent↗
PubMed1995

Nonspecific bronchial hyperresponsiveness and development of asthma in children with hay fever.

It has been suggested that patients with allergic rhinitis who present nonspecific bronchial hyperresponsiveness (BHR) are those most likely to develop asthma. Therefore, a study was conducted in children with rhinoconjunctivitis to ascertain whether BHR to methacholine might predict the development of asthma in these patients. Fifteen patients with hay fever and no previous symptoms of asthma were selected. All underwent clinical symptom tests and methacholine tests, during the pollen season in the 4 consecutive years following the start of the study. At the end of this period, 5 patients had developed asthma. It may thus be affirmed that, in this group, neither the presence nor the degree of previous BHR was useful for predicting which patients would later develop asthma.

Asthma↗
PubMed1994

Exercise-induced anaphylactic reaction to hazelnut.

Reproducible, exercise-induced anaphylactic reactions occur in some patients only after certain foods have been eaten before exercise. We describe a patient in whom hazelnuts were a triggering factor for exercise-induced anaphylaxis. Skin tests and RAST were positive for nuts and grass and weed pollen. The exercise challenge test after hazelnut ingestion was positive. Food hypersensitivity should be investigated in all cases of exercise-induced anaphylaxis.

Anaphylaxis↗
PubMed1993

Lung function and bronchial response to methacholine in young adults who had asthma in childhood.

Lung function and bronchial response to methacholine were studied in 47 young adults who had had childhood asthma, and after a period of 14-21 years, showed a different clinical evolution. At present, these subjects have been classified in four clinical groups: asymptomatic, rhinitic, asthmatic only due to exercise, and asthmatic. The same study was performed in 23 healthy individuals without personal histories of respiratory or allergic pathology. We found low spirometric basal values in both the asthmatic group (FEV1 and FEF25-75) and in the group with asthmatic responses to exercise (FEF25-75). No significant differences were found among asymptomatic, rhinitic, and control groups. While airway hyperreactivity was observed in patients who still had asthma, the bronchial response to methacholine in asymptomatic and rhinitic groups was not different from the control group. We conclude that both lung function and bronchial response to methacholine in most of the adults who had asthma in infancy and had been without asthmatic symptoms for many years are similar to those observed in the general population.

Adolescent↗
PubMed1992

Asthma with sulfite intolerance in children: a blocking study with cyanocobalamin.

Sulfites have been implicated as the cause of bronchospasm in some subjects with asthma. However, there is still no universally accepted explanation of the pathogenesis of these reactions. We have studied five children with asthma with metabisulfite intolerance confirmed by oral challenge testing. The challenge test with metabisulfite was repeated after premedication of all the patients with 1.5 mg of oral cyanocobalamin. In four of the five patients treated with cyanocobalamin, bronchospasm did not develop in the second metabisulfite challenge. The possible mechanisms are discussed.

Administration, Oral↗
PubMed1988

A possible consequence of long-term elimination diet in IgE mediated subclinical food hypersensitivity.

IgE-mediated sub-clinical food hypersensitivity is recognized, but the hypersensitivity indicated is not always in accord with the observed symptoms. Study of 2 cases shows the inefficacy of a prescribed exclusion diet, without confirmation of the relationship between symptomatology and the food allergy. In addition, elimination of the foods aggravated the sensitivity of the patients and symptoms after provocation tests. Further studies must be made to decide whether there is a sound basis for long-term exclusion diets in sub-clinical food hypersensitivity.

Animals↗
PubMed1987

[Food allergy in children. I. Clinical aspects and diagnosis].

Two hundred and thirty children with suspected food allergy have been reviewed retrospectively. One hundred and nine fulfilled the following three selection criteria: suggestive anamnesis, presence of specific IgE antibodies (in serum or by skin prick test), and having been reassessed at least once. The major clinical data analyzed were: age of onset, sensitising foods, symptomatology and diagnostic procedures. The results show a mean age of onset for food allergy of 11.5 months, with variations related to the sensitizing food, cow's milk allergy being the earliest in onset time. The most frequent sensitizing foods in this group of patients were eggs, fish and cow's milk. The skin and the gastrointestinal tract have been the most affected shock organs, both together or isolated; respiratory symptoms were an uncommon finding and their isolated presentation as the sole manifestation of food allergy exceptional. The skin prick tests were positive in 99.2 percent of the sensitizations and in 84 percent high levels of specific IgE antibodies were found. Food allergy seems to be a common situation in children, clinical symptomatology is similar to that of the other atopic diseases and the diagnosis is based on the demonstration of specific IgE antibodies against the sensitizing foods.

Age Factors↗
PubMed1987

[Food allergy in children. II. Prognostic factors and long-term development].

The evolution of 109 allergic children with 129 IgE-mediated food sensitizations has been evaluated. The follow-up period was from nine months to 14 years. The period up to clinical tolerance was analyzed, together with the influence of two possible prognostic factors: specific IgE antibody levels at the beginning of symptomatology and the sensitizing food. Moreover, when clinical tolerance was achieved, the presence of specific IgE antibodies was again assessed. Probability estimations indicated that 30% of food-allergic children become clinically tolerant before 3 years of evolution, 40% before 6 years, 50% before 9 years and 53% before 12 years. Onset of clinical tolerance varies in dependence with the offending food: clinical tolerance to cow's milk seems to be far earlier and easier to reach than those to egg and fish (p less than 0.001, at 9 years' evolution); allergy to egg disappears also earlier and easier than fish allergy (p less than 0.01). Levels of specific IgE antibodies at the onset of the disease show significant difference (p less than 0.01) between the patients which will become tolerant and those with persistence of clinical sensitivity, being higher in the last group. However, a high number of patients who become clinically tolerant (67.5%) remained positive at skin prick testing or had elevated specific IgE serum antibodies against the offending food.

Animals↗
PubMed1986

Allergy to white potato.

Allergy to potato is uncommon, and even more uncommon is allergy to potato pollen. The occurrence of both phenomena in the same patient made it possible to study cross-reactivity patterns of potato antigens. An 11-year-old girl, exclusively breast-fed for her first 4 months, developed anaphylactic symptoms after ingestion of potato at 5 months of age when she was fed potato for the first time. Subsequently, she developed urticaria, angioedema, and respiratory and systemic symptoms on contact with potatoes, ingestion of potatoes, and exposure to cooking potatoes or potato pollen. Three allergenic extracts from potato pulp, peel, and pollen were prepared. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and isoelectrofocusing of the three extracts were performed. IgE-mediated allergy to these extracts was demonstrated by means of immediate skin test reactivity, positive passive transfer, RAST, RAST inhibition, and leukocyte histamine release. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the pulp extract followed by electroblotting and autoradiography demonstrated specific IgE antibodies directed against several proteins ranging from 14,000 to 40,000 daltons.

Child↗