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C Y Pascual

Publications and source records attributed to C Y Pascual.

At least 19 recordsLinked to original sources
PubMed2006

A comparative analysis of the cross-reactivity in the polcalcin family including Syr v 3, a new member from lilac pollen.

BACKGROUND: Polcalcins are pollen-specific allergens with two EF-hand calcium-binding sites that exhibit strong cross-reactivity. Our objective was to isolate and express the cDNA coding of the EF-hand calcium-binding allergen from lilac pollen and to study cross-reactivity with other polcalcins from related and nonrelated pollen sources with different specific antibodies and sera from two different populations. METHODS: Specific cDNA was amplified by PCR, cloned and expressed in Escherichia coli. Purification was achieved by gel permeation and ion exchange chromatographies. ELISA titration and inhibition assays were performed using the recombinant forms of Syr v 3, Ole e 3, Che a 3 and Phl p 7 with sera from two Spanish regions with different sensitization profiles, as well as Phl p 7- and Ole e 3-specific polyclonal rabbit antisera, and an Ole e 3-specific monoclonal antibody. RESULTS: Syr v 3 displays two EF-hand consensus sites and 8863 Da of theoretical molecular mass. The allergen consists of 80 residues with identities ranging from 66 to 87% with polcalcins included in this study. Syr v 3, Ole e 3, Che a 3 and Phl p 7 showed a similar IgG- and IgE-binding capacity although differences at quantitative level were observed depending on the population of patients' sera. CONCLUSION: Syr v 3 is a polcalcin with structural and antigenic similarities to the members of this family. Diagnosis of polcalcin-sensitized patients could be performed whatever polcalcin used, whereas for immunotherapy, primary sensitization to a particular allergenic source should be considered.

Allergens↗
PubMed2006

Palatability of hydrolysates and Other substitution formulas for cow's milk-allergic children: a comparative study of taste, smell, and texture evaluated by healthy volunteers.

BACKGROUND: Hydrolyzed formulas used to feed infants with cow's milk-allergy can be classified as soy based, extensively hydrolyzed (casein, whey and mixed), and amino-acid based. Their unsatisfactory taste is reported by parents and physicians. OBJECTIVE: The aim of this study was to ascertain the palatability of these formulas in a double-blind taste test. MATERIALS AND METHODS: Fifty healthy volunteers performed a randomized-order double-blind test with 12 different milks. The taste, smell, smell, and texture of each formula were evaluated o n scales ranging from 1 (worst) t o 5 (best). The Pearson correlation coefficient between the peptide weight of each formula and the score obtained for each evaluated attribute was calculated. RESULTS: The soy formulas and rice formula had the best taste scores, followed by the whey hydrolysates; the mixed hydrolysates and the casein hydrolysates had the lowest taste scores. Individually the most palatable formula was mixed hydrolysate 1, by total score. We found a statistically significant correlation between peptide weight, reflecting the degree of hydrolysis of each formula, and the scores obtained for taste, texture, and overall palatability. CONCLUSION: The palatability of formulas is determined by the amount of bitter peptides obtained through hydrolysis. Flavorings and sweeteners may also contribute to palatability. Further studies are needed in order to determine how to modify the organoleptic properties of these products with the purpose of improving their palatability.

Adult↗
PubMed2004

Vicilin and convicilin are potential major allergens from pea.

BACKGROUND: Allergic reactions to pea (Pisum sativum) ingestion are frequently associated with lentil allergy in the Spanish population. Vicilin have been described as a major lentil allergen. OBJECTIVE: To identify the main IgE binding components from pea seeds and to study their potential cross-reactivity with lentil vicilin. METHODS: A serum pool or individual sera from 18 patients with pea allergy were used to detect IgE binding proteins from pea seeds by immunodetection and immunoblot inhibition assays. Protein preparations enriched in pea vicilin were obtained by gel filtration chromatography followed by reverse-phase high-performance liquid chromatography (HPLC). IgE binding components were identified by means of N-terminal amino acid sequencing. Complete cDNAs encoding pea vicilin were isolated by PCR, using primers based on the amino acid sequence of the reactive proteins. RESULTS: IgE immunodetection of crude pea extracts revealed that convicilin (63 kDa), as well as vicilin (44 kDa) and one of its proteolytic fragments (32 kDa), reacted with more than 50% of the individual sera tested. Additional proteolytic subunits of vicilin (36, 16 and 13 kDa) bound IgE from approximately 20% of the sera. The lentil vicilin allergen Len c 1 strongly inhibited the IgE binding to all components mentioned above. The characterization of cDNA clones encoding pea vicilin has allowed the deduction of its complete amino acid sequence (90% of sequence identity to Len c 1), as well as those of its reactive proteolytic processed subunits. CONCLUSIONS: Vicilin and convicilin are potential major allergens from pea seeds. Furthermore, proteolytic fragments from vicilin are also relevant IgE binding pea components. All these proteins cross-react with the major lentil allergen Len c 1.

Adolescent↗
PubMed2002

IgE-mediated anaphylaxis to Thiomucase, a mucopolyssacharidase: allergens and cross-reactivity.

BACKGROUND: Thiomucase is a mucopolysaccharidase obtained from ovine tissues mainly used to facilitate the diffusion of local anaesthetics and in the treatment of cellulitis. A patient with an anaphylaxis in relation to the intramuscular administration of Thiomucase is reported. OBJECTIVE: To investigate Thiomucase allergens and their possible relationship with dander allergens and animal albumins. MATERIAL AND METHODS: Skin prick tests (SPT) and serum-specific IgE were performed with Thiomucase and danders. Thiomucase SDS-PAGE immunoblotting was performed in order to study allergens. RAST/CAP inhibition and SDS-PAGE immunoblotting inhibition were carried out to study the cross-reactivity. RESULTS: Skin prick tests (SPT) were positive to Thiomucase, animal dander (cat, dog, sheep, other), bovine serum albumin (BSA), and echinococcus. Specific IgE was also positive to Thiomucase, animal dander (cat, dog, sheep, other), BSA and echinococcus. In the RAST-CAP inhibition assays BSA was nearly completely inhibited by Thiomucase, Thiomucase was partially inhibited by BSA and cat and Echinococcus granulosus was partially inhibited by sheep and Thiomucase. In the Thiomucase SDS-PAGE immunoblotting several proteins fixed IgE, ranging from 20 kDa to > 94 kDa, the strongest with 43 kDa. The IgE fixation to BSA, cat and sheep in the SDS-PAGE immunoblotting was completely inhibited by the preincubation of the serum with Thiomucase. CONCLUSIONS: An IgE-mediated anaphylaxis to Thiomucase is documented. Multiple allergens are recognized in Thiomucase by the patient serum, the main with 43 kDa. Partial cross-reactivity with BSA, cat dander and sheep dander is documented.

Anaphylaxis↗
PubMed2002

Are Ca2+-binding motifs involved in the immunoglobin E-binding of allergens? Olive pollen allergens as model of study.

BACKGROUND: Several Ca2+-binding proteins, which possess EF-hand sites with a high sequence similarity, have been found to be able to induce Type-I allergy. OBJECTIVE: To study whether the common EF-hand sequential motifs can be involved in the IgE-reactivity of these proteins, thus being responsible of a degree of cross-reactivity among different Ca2+-binding proteins. METHODS: Two olive pollen allergens, Ole e 3 and Ole e 8, have been used in the study. Parvalbumin and calmodulin were included in immunological analyses. Sera from patients allergic to olive pollen, as well as Ole e 3- and Ole e 8-specific rabbit antisera were used in indirect enzyme-linked immunosorbent assay (ELISA), ELISA inhibition assays and immunoblotting. Conformational analyses (circular dichroism spectra and thermal stability) and specific immunodetection assays were performed in the presence and the absence of Ca2+. Chemical breakdown and high-performance liquid chromatography (HPLC) was used to obtain fragments from Ole e 3 containing a single EF-hand motif. RESULTS: Thirty-four (17%) and 16 (8.2%) out of 195 sera from patients allergic to olive pollen contained specific IgE against Ole e 3 and Ole e 8, respectively. The IgE-binding of 12 allergic sera diminished up to 22% for Ole e 3 and to 82% for Ole e 8, when depleted Ca2+. A pool of these sera recognized the two olive allergens and parvalbumin, but at very different extent. Inhibition of the IgE-binding was only achieved between two olive allergens. No structural relationships between Ole e 3 and Ole e 8 were established when specific polyclonal antisera against both proteins were used. CONCLUSION: EF-hand Ca2+-binding sites can not be considered as general allergenic motifs responsible for the cross-reactivity between Ca2+-binding allergens. Different families of Ca2+-binding allergens have specific epitopes that could be involved in the cross-reactivity among members of the same family.

Adolescent↗
PubMed2001

Serum CD23 is not altered in gastroallergic anisakiasis, but correlates with the production of specific IgE and the amount of polyclonal stimulation.

BACKGROUND: Previous studies have shown elevated serum levels of the cytokines IL-4 and sCD23 in atopic patients and parasitic disease. Gastroallergic anisakiasis is an acute parasitic disease, accompanied by IgE-mediated clinical symptoms and an important increase of specific and total IgE. METHODS: Sixteen patients with acute urticaria/angioedema due to parasitism by Anisakis simplex after intake of raw or undercooked fish were selected, and serum samples were taken in the emergency room within 24 h (day 0; n=16), after 1 month (n=16), and after 6 months (n=10). Serum samples were studied for specific IgE against A. simplex, total IgE, sCD23, and IL-4. RESULTS: Mean values for sCD23 did not change in the observation period. Only 4/16 serum samples showed measurable IL-4 levels. Specific IgE and total IgE levels were found to be elevated after 1 month; after 6 months, they fell to nearly basal values. There was a positive correlation between sCD23 and specific IgE at day 0 and follow-up (r=0.55-0.69, P<0.026); a positive correlation between sCD23 and total IgE (r=0.54-0.62, P<0.056). Basal sCD23 could moderately predict the percentual increment of total IgE in the first month (r=0.56, P<0.038). CONCLUSION: Thus, it seems that interindividual variability of sCD23 is an important factor, with higher values predisposing to more production of unrelated IgE, independently of the parasite's action.

Animals↗
PubMed2001

Tomato allergy in children and young adults: cross-reactivity with latex and potato.

BACKGROUND: Several studies have shown that allergy to natural rubber latex is associated with cross-reactivity to certain foods such as tomato and potato. The objective was to investigate the clinical and immunologic differences between a group of patients with clinical allergy to tomato and latex and another which had only clinical allergy to tomato. We also aimed to assess, in vitro, the relationship of tomato and latex allergens, which could explain the cross-reactivity. METHODS: Forty patients with histories of adverse reactions to tomato and IgE-mediated hypersensitivity were enrolled in the study. Tomato, latex, and potato components were analyzed by SDS-PAGE immunoblotting. CAP and immunoblot inhibition were used to study allergen cross-reactivity. RESULTS: Patients from group A had a mean age of 13.2 years, and in group B the mean age was 21.7 years. In group B, 9/10 patients belonged to the latex-fruits syndrome. All patients of both groups tolerated potato. Immunoblotting patterns obtained with patients' sera from pool A showed IgE-binding bands to tomato ranging from 44 to 46 kDa and a triple band at 67 kDa. For latex, there was a strong binding at 44 kDa, and potato showed a strong band of 44 kDa and a 67-kDa triple band. In pool B, the binding to the band of 44 kDa in latex and tomato was more intense than in pool A. In pool A, immunoblot inhibition with potato allergen showed an intense inhibition of the three allergens (potato, latex, and tomato); with latex, inhibition was partial and with tomato, a complete inhibition of tomato and latex was observed, and a partial inhibition of potato. In pool B, the inhibition pattern followed a similar tendency to pool A. The CAP inhibition confirmed the high rate of cross-reactivity between tomato, potato, and latex. CONCLUSIONS: In our study, tomato, potato, and latex showed a common band of 44-46 kDa probably corresponding to patatin. This protein could be implicated in the high cross-reactivity between tomato, latex, and potato observed in the immunoblot and CAP inhibition.

Adolescent↗
PubMed2000

Food allergy and intolerance in children and adolescents, an update.

Epidemiological surveys demonstrate that rapid increase in allergic diseases is a real phenomenon. In developed countries they are about the commonest chronic diseases, reaching between 15% and 30% of the population. Adverse reaction to food can be divided into toxic reaction and non-toxic reactions. The non-toxic reactions are divided into non-immune mediated and immune mediated, these are considered food allergic reactions. We showed our experience in a 4 y survey, individualized by food allergens during the first two years of life. In Spain egg white protein is the most common allergen followed by cow's milk and peanuts. These three food items represent half of the sensitizations in children under 2 y of age. After 4 y sensitivities to vegetable allergens such as nuts, fruits and legumes are most frequent. The diagnosis of food allergy is still problematic, even in the case of atopy or IgE mediated hypersensitivity. There is a lack of standardized diagnostic procedures; the only test accepted as 'gold standard' for confirmation of food allergy and in general for food intolerance, is a properly performed double blind placebo-controlled oral food challenge. Negative results should be always followed by an open food challenge. This test should only be conducted in patients with a good medical condition and in a clinic or hospital setting, and only if trained personal and equipment for treating systemic anaphylaxis are present. Contraindications to a challenge test are limited to those situations that can be hazardous for the patient in relationship to the studied food. The treatment of food allergy and intolerance is avoiding the implicated food as long as necessary, until tolerance appears. Prevention of food allergy is the first goal of every pediatric allergologist. Controlled trials of food allergy prevention have been performed only in high allergic risk children.

Adolescent↗
PubMed2000

Isolation and characterization of relevant allergens from boiled lentils.

BACKGROUND: Lentils seem to be the most common legume implicated in pediatric allergic patients in the Mediterranean area. However, no lentil allergen has been isolated and characterized. OBJECTIVE: We sought to purify and characterize relevant IgE-binding proteins from boiled lentil extracts. METHODS: IgE-binding proteins from crude and boiled lentil extracts were detected with a pool of sera from patients with lentil allergy. Allergens were isolated by gel-filtration chromatography followed by cation- and anion-exchange chromatography or by reverse-phase HPLC. Their characterization included N-terminal amino acid sequencing, complex asparagine-linked glycan detection, specific IgE immunodetection with 22 individual sera from allergic patients, and immunoblot and CAP inhibition assays. RESULTS: Heat treatment of lentils produced substantial changes in the SDS-PAGE patterns of whole extracts, mainly a strong increase of 12- to 16-kd bands and a decrease of 25- to 45-kd components. Major IgE-binding proteins from the boiled lentil extract were located in the 12- to 16-kd and 45- to 70-kd ranges. Two allergens of 16 kd, proteins L1 and L2, and another one of 12 kd, protein L3, were purified. N-terminal sequencing indicated that all 3 were related and allowed their identification as gamma-vicilin subunits. Protein L1 was recognized by 68% of the individual sera tested and inhibited 64% of the IgE binding by commercial lentil CAPs. A second type of allergen of 66 kd, named protein H, was also isolated and identified as a seed-specific biotinylated protein. Protein H reacted with 41% of the individual sera and produced 45% inhibition in CAP inhibition assays. CONCLUSIONS: Two different types of allergens have been identified in boiled lentils. Those of 12 to 16 kd, called Len c 1, correspond to gamma-vicilin subunits, and those of 66 kd, designated Len c 2, correspond to seed-specific biotinylated protein. Homology with proteins from other legume species can explain potential cross-reactions among these foods.

Allergens↗
PubMed1999

Allergy to lentils in Mediterranean pediatric patients.

BACKGROUND: Peanuts and soybeans are the major legumes involved in human food allergy; however, scarce data exist on adverse reactions to other temperate legumes, such as lentils. OBJECTIVE: The purpose of this study was to identify patients who are allergic to lentils, to assess clinical features and other associated food allergies, and to characterize allergens in lentil extract. METHODS: Twenty-two children each with a history of adverse reactions to lentils were enrolled in the study. The diagnosis of lentil allergy was based on food challenges or a convincing history of anaphylaxis, with positive skin tests and/or specific serum IgE to lentils. Lentil components were characterized by SDS-PAGE immunoblotting. RESULTS: Twenty of 22 subjects had symptomatic allergy to lentils at the diagnostic time. The most frequent symptoms were oropharyngeal symptoms (40%) and acute urticaria (30%); 3 patients also reported symptoms when they were exposed to steam from cooked lentils. In 18 patients, symptoms after lentil ingestion started under 4 years of age (median, 2.7 years). Nine patients had allergic reactions to other legumes: chick peas (6 patients), peas (2 patients), and green beans (1 patient). Immunoblotting patterns obtained with patients' sera showed IgE-binding bands ranging from 14 to 84 kd. Five sera recognized 9 or more IgE-binding bands, and more than 50% of patients who were tested have specific IgE antibodies to 7 components in lentil extract. CONCLUSION: Allergic reactions to lentils started early in life, usually below 4 years of age; oropharyngeal symptoms and acute urticaria were the most common symptoms through ingestion, and symptomatic reactivity to chick peas is frequently associated.

Child↗
PubMed1999

Food allergies in Spain: causal allergens and diagnostic strategies.

A correct diagnosis of food allergy in the child is based on a careful medical history, together with the demonstration of specific IgE for the involved foods. However, before establishing an elimination diet, the "food-symptoms" relationship must be proven through a controlled challenge test.

Child↗
PubMed1998

Specific IgE to recombinant vegetal panallergen (rBet v 2) and fruit allergy in pollinic patients.

The presence of IgE antibodies to the allergens rBet v 1 and rBet v 2 was investigated in patients with known sensitization to ryegrass (Lolium perenne) and/or olive (Olea europaea) pollen, by comparing a group of 10 patients who had allergic symptoms after ingestion of fruits (A) with a group of 17 patients who had only seasonal respiratory symptoms (B). There was no significant difference between the two groups for total IgE. All patients showed specific IgE to both L. perenne and O. europaea. No specific IgE binding to rBet v 1 was detected in any patient. The incidence of the presence of IgE antibodies to rBet v 2 was 90% in the group with fruit allergy (A) and 35% in group B. We found a significant association between presence of IgE antibodies to rBet v 2 and fruit allergy (P = 0.007). Specific IgE values to O. europaea pollen were higher in the fruit-allergy group than the group without fruit allergy (P = 0.032). In conclusion, pollen-allergic patients with specific IgE to birch pollen profilin show a significantly elevated frequency of fruit allergy.

Adolescent↗
PubMed1997

Cross-reactivity between IgE-binding proteins from Anisakis, German cockroach, and chironomids.

Anisakis simplex larvae parasitize animals used as seafood and can produce a specific immune response in man. The ingestion of seafood contaminated with stage three of A. simplex larvae can induce a specific IgE response with clinical symptoms, usually urticaria, even if the fish is cooked before ingestion and the invasive infestation power destroyed by heating. Our preliminary studies showed a strong association of A. simplex sensitization with Ascaris lumbricoides, Daphnia, chironomid spp., Atlantic shrimp (Pandalus borealis), and German cockroach (Blattella germanica). We conducted the cross-reactivity study with cockroach, a ubiquitous insect, and Chironomidae (red mosquito larvae), a work-related allergen, without any possibility of Anisakis contamination. Serum samples were collected from 60 pediatric patients, with serum specific IgE to A. simplex. Both specific-IgE and immunoblot-inhibition studies, with a serum pool from 18 patients, were performed to determine whether the association of sensitizations to nematodes and arthropods was due to immunologic cross-reactivity. In addition, serum samples from 21 of 60 patients who showed also sensitization to German cockroach were used for individual immunoblot studies. In the serum pool, dose-dependent inhibition of B. germanica and Chironomus spp, was observed after preincubation with the A. simplex extract. Immunoblot of Anisakis, inhibited with Chironomus and German cockroach, yielded a partial blot inhibition but mainly on bands below 41 kDa. Blot inhibition of German cockroach and Chironomus with Anisakis was dose related. The band patterns in individual blots were heterogeneous, but most of them had bands of 30-43 kDa. None of these sera recognized allergens in the 14-kDa area. In our study, CAP-inhibition and immunoblot-inhibition analysis of Anisakis showed that several IgE-binding components could be shared by the three allergens.

Allergens↗
PubMed1992

Evaluation of two commercial enzyme immunoassays for the diagnosis of Helicobacter pylori infection.

Sera from 65 patients with upper gastrointestinal tract symptoms and proven Helicobacter pylori infection, and from 42 negative controls were tested with two commercial EIAs (GAP test, BioRad; and ECP test, Biometra) and two non-commercial EIAs, one performed with whole sonicated cells and the other with acid extract of Helicobacter pylori as antigen. The GAP assay showed a sensitivity of 83.1% and a specificity of 47.6%. The ECP assay showed a sensitivity of 87.7% and a specificity of 61.9%. For both non-commercial EIAs these figures were 87.7% and 88.1%, respectively. Independent of the interpretive criteria established by the manufacturers, receiver operating characteristic curves were plotted for better evaluation of the four methods. Both commercial tests showed a lower probability of yielding a correct diagnosis than the non-commercial tests (p less than 0.05). Although commercial EIAs are convenient for the diagnosis of Helicobacter pylori infection, the accuracy of the two commercial tests evaluated in this study was lower compared to that of the two non-commercial EIAs.

Adult↗