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Biomedical subjects

M Fernández-Rivas

Publications and source records attributed to M Fernández-Rivas.

At least 19 recordsLinked to original sources
PubMed2005

The effect of thermal processing on the IgE reactivity of the non-specific lipid transfer protein from apple, Mal d 3.

BACKGROUND: Non-specific lipid transfer proteins (LTPs) are involved in allergy to fresh and processed fruits. We have investigated the effect of thermal treatment and glycation on the physico-chemical and IgE-binding properties of the LTP from apple (Mal d 3). METHODS: Mal d 3 was purified from apple peel and the effect of heating in the absence and presence of glucose investigated by CD spectroscopy, electrospray and MALDI-TOF mass spectrometry. IgE reactivity was determined by RAST and immunoblot inhibition, SPT and basophil histamine release test. RESULTS: The identity and IgE reactivity of purified Mal d 3 was confirmed. Mild heat treatment (90 degrees C, 20 min) in the absence or presence of glucose did not alter its IgE reactivity. More severe heat treatment (100 degrees C, 2 h) induced minor changes in protein structure, but a significant decrease in IgE-binding (30-fold) and biological activity (100- to 1000-fold). Addition of glucose resulted in up to four glucose residues attached to Mal d 3 and only a 2- and 10-fold decrease of IgE-binding and biological activity, respectively. CONCLUSIONS: Only severe heat treatment caused a significant decrease in the allergenicity of Mal d 3 but glycation had a protective effect. The presence of sugars in fruits may contribute to the thermostability of the allergenic activity of LTP in heat-processed foods.

Allergens↗
PubMed2003

Peach profilin: cloning, heterologous expression and cross-reactivity with Bet v 2.

BACKGROUND: Peach is among the main foods causing allergic reactions in the Mediterranean adult population. Only a single peach allergen, named Pru p 3, has been characterized. However, a potential role of profilin has also been suggested in grass pollen-associated allergy to peach. METHODS: Complementary DNA clones for two different peach profilin isoforms were obtained by reverse transcriptase polymerase chain reaction using non-degenerated primers. Expression of recombinant peach profilin was performed in Escherichia coli, and confirmed using rabbit polyclonal antibodies to sunflower pollen profilin. Twenty-nine individual sera from patients with peach allergy proved by double-blind, placebo-controlled food challenges (DBPCFC), either with (n = 15) or without (n = 14) specific IgE to Bet v 2, were used in immunodetection assays to test recombinant peach profilin reactivity. RESULTS: Each peach profilin cDNA included an open reading frame coding for a 131 amino acid protein. The peach profilin isoforms, designated Pru p 4.01 and Pru p 4.02, showed 80% of amino acid sequence identity, and were very similar (>70% identity) to allergenic profilins from plant foods and pollens. Recombinant Pru p 4.01 was expressed in E. coli as a nonfusion protein, displaying the expected molecular size and reacting with anti-profilin antibodies. rPru p 4.01 was recognized by all sera (15 of 15) with specific IgE to Bet v 2, whereas no sera (zero of 14) without IgE to this birch allergen reacted with rPru p 4.01. CONCLUSIONS: Peach profilin Pru p 4 is very closed to other allergenic profilins from plant foods and pollens. A complete correlation between reactivity to rPru p 4 and rBet v 2 has been found in sera from peach allergic patients.

Adolescent↗
PubMed2003

Tolerance of a cluster schedule on the treatment of seasonal allergic respiratory disease with pollen extracts quantified in mass units.

In order to evaluate the tolerance of a cluster schedule on specific immunotherapy (SIT), 306 patients were included in a multicenter study. The patients were suffering from rhinoconjunctivitis with/without asthma, caused by sensitization to olive and/or grass pollen. SIT was administered subcutaneously according to a cluster schedule in which the maintenance dose is reached after four visits (3 weeks). The extracts were biologically standardized with major allergens quantified in mass units. Local reactions appeared in 7.2% of the patients and 1.3% of the doses. Systemic reactions (SR) were recorded in 1.2% of the doses administered to 9.5% of the patients. No anaphylactic shock was registered, and all the SR responded fully and rapidly to treatment. There was no difference in SR according to diagnosis or allergen extract used. The majority of SR occurred with the administration of vial of higher concentration (Vial 2: 7 SR (22%), Vial 3: 32 SR (78%), p < 0.05). Of the 32 SR recorded with Vial 3, 13 (41%) were immediate, with no existing association between dose administered and appearance of SR. However, of the 18 delayed SR (56%), 14 occurred after the administration of the first two doses of Vial 3 and four occurred after administration of the second two doses (78% vs 22%, p < 0.05). On the other hand, this regime realized an important saving in cost and time compared to the conventional schedule (1581 fewer doses and 2754 fewer visits were necessary to reach the optimal dose). Considering all these factors, the clinical profile of the proposed regime may be qualified as good. However, future studies are necessary in order to better adjust the schedule to avoid the delayed SR that occurred after the administration of the first two doses of Vial 3.

Adult↗
PubMed2000

Lipid-transfer proteins as potential plant panallergens: cross-reactivity among proteins of Artemisia pollen, Castanea nut and Rosaceae fruits, with different IgE-binding capacities.

BACKGROUND: Lipid-transfer proteins (LTPs), but not Bet v 1 homologues, have been identified as major allergens of apple and peach in the Rosaceae fruit-allergic population in the Mediterranean area. Many of these patients show cosensitization to mugwort pollen. LTPs have an ubiquitous distribution in tissues of many plant species, and have been proposed as a novel type of plant panallergens. OBJECTIVE: We sought to isolate LTPs from Artemisia pollen and from a plant food not belonging to the Rosaceae family, such as chestnut nut, and to compare their amino acid sequences and IgE-binding capacities with those of apple and peach LTPs. METHODS: Allergens (LTPs) were isolated by different chromatographic methods (gel-filtration, ion exchange and/or reverse-phase HPLC), and characterized by N-terminal amino acid sequencing and MALDI analysis. Specific IgE-quantification and immunodetection, as well as immunoblot and ELISA inhibition assays, were carried out using sera from patients allergic to both apple and peach. RESULTS: Purified LTPs from Artemisia pollen and from chestnut seed showed molecular masses about 9 700d, and 43-50% sequence identity with the equivalent allergens of apple and peach in the first 30 N-terminal residues, which comprise about one third of the total amino acid sequence. A similar degree of sequence identity (50%) was found between the Artemisia and chestnut proteins. Both isolated LTPs bound specific IgE of sera from Rosaceae fruits allergic patients. However, substantially lower values of specific IgE-binding and maximum ELISA inhibition percentages were obtained for Artemisia and chestnut LTPs when compared to those from apple and peach. CONCLUSION: LTPs from Artemisia pollen and chestnut crossreact with allergens (LTPs) of Rosaceae fruits, but significant differences in specific IgE-binding capacities were observed among members of the plant LTP family. Thus, further studies are needed to evaluate the clinical significance of the observed cross-reactivities of plant LTPs.

Allergens↗
PubMed1999

Peels of Rosaceae fruits have a higher allergenicity than pulps.

BACKGROUND: It is not uncommon that patients allergic to fruits such as apple, pear, and peach, refer adverse reactions after the ingestion of the whole fruit, but subsequently tolerate the pulp. OBJECTIVE: This study aimed to compare the allergenicity of peels and pulps of apple, peach, and pear in 33 patients allergic to these fruits. METHODS: Clinical reactivity to the ingestion of whole fruit (peel + pulp) and pulp was established by medical history. Peels and pulps were tested separately in skin prick tests (SPTs), histamine release tests (HRTs) and RASTs. Cross-allergenicity between peel and pulp of apple and peach was studied by RAST inhibition. RESULTS: Adverse reactions appeared more frequently and were more severe when the whole fruit was eaten. More than 40% of patients allergic to apple and pear tolerated the ingestion of the pulp of these fruits, and reactions were only elicited by the intake of the whole fruit. Peels induced higher SPTs, HRTs and RASTs than pulps. An important cross-allergenicity was found between the peel and pulp of apple and peach, although the amount of the shared allergenic epitopes seemed to be higher in peels. CONCLUSION: Our results suggest that peels of Rosaceae fruits such as apple, peach, and pear, have a higher allergenicity than pulps, which is clinically relevant. This aspect should be considered in the evaluation of patients allergic to Rosaceae fruits, and in the production of diagnostic materials.

Adolescent↗
PubMed1997

Allergy to Rosaceae fruits without related pollinosis.

BACKGROUND: Rosaceae fruit allergy is frequently associated with birch pollinosis in Central and Northern Europe and with grass pollen allergy in Central Spain. The main cross-reactive structures involved for birch pollinosis are Bet v 1 and profilin, and for grass pollinosis they are profilin and carbohydrate determinants. Rosaceae fruit allergy can occasionally be observed in patients without pollinosis. OBJECTIVE: We investigated the clinical presentation and the allergens involved in allergy to Rosaceae fruit without pollinosis. METHODS: Eleven patients from Central Spain allergic to apples, peaches, and/or pears but not to pollens were compared with 22 control subjects with combined grass pollen and fruit allergy. Skin prick tests and RASTs to apple, peach, and pear were performed. Cross-allergenicity was studied by RAST inhibition. Bet v 1 was tested with an indirect RAST, and profilin was tested in skin prick tests, histamine release, and RAST. RESULTS: Rosaceae fruit allergy without pollinosis is severe with 82% of patients reporting systemic symptoms, mainly anaphylaxis (73%), whereas oral symptoms are less frequent (64%). Anaphylactic shock was observed in 36% of patients. The fruit allergens involved showed cross-reactivity among Rosaceae species but were not related to profilin or Bet v 1. Ninety-one percent of patients with combined grass pollinosis and fruit allergy reported oral allergy, 45% reported systemic symptoms, 18% reported anaphylaxis, and 9% reported anaphylactic shock. CONCLUSION: Allergy to Rosaceae fruits in patients without a related pollen allergy is a severe clinical entity. Profilin- and Bet v 1-related structures are not involved in Rosaceae fruit allergy without pollinosis.

Adolescent↗
PubMed1997

Improvement of fruit allergenic extracts for immunoblotting experiments.

A method based on ion-exchange column chromatography to enhance the protein content of fruit allergenic extracts was found to help make the subsequent SDS-PAGE immunoblotting assays possible; otherwise, they were difficult to achieve due to the high carbohydrate content. Fractionated extracts of apple, pear, and peach (peel and pulp) were obtained by anion-exchange chromatography (Q-Sepharose column), providing clear electrophoretic patterns which allowed IgE detection by enzymatic assays of the transferred membranes. This chromatographic method produced in one single step an enriched extract directly from the standard crude aqueous one, with an increment in the protein content of more than sixfold, on average; thus, it proved to be more suitable than the usual chemical fractionation procedures.

Allergens↗
PubMed1997

Occupational asthma and rhinitis caused by ash (Fraxinus excelsior) wood dust.

An 18-year-old man who worked in a furniture factory reported rhinitis and asthma when he was exposed to ash wood dust. Monitoring of the patient's peak expiratory flow rate (PEFR) when off work and at work showed increased variations of PEFR at work. Basal PC20 methacholine was 1.41 mg/ml. A bronchial provocation test (BPT) with a 1:1000 w/v ash wood dust extract induced a dual asthmatic response with a 7.5-fold increase of nonspecific bronchial responsiveness. Intradermal testing with ash wood extract elicited a positive immediate response. IgE antibodies against ash wood were found in the patient's serum with a RAST value of 0.57 PRU/ ml. Similar skin tests, BPT, and RAST with ash wood dust performed in control patients were all negative. All the studies performed suggest that our patient had occupational rhinitis and asthma caused by exposure to ash wood dust in which a type I immunologic mechanism was implicated.

Adolescent↗
PubMed1995

Pollen-related allergy to peach and apple: an important role for profilin.

BACKGROUND: Birch pollinosis is often accompanied by allergy to fruits such as peach and apple. Bet v I is of major importance as cross-reactive allergen for this combined allergy. We studied a group of patients with combined grass pollinosis and fruit allergy from an area virtually without birch trees. OBJECTIVE: The aim of this study was to investigate the possible involvement of profilin and carbohydrate groups as cross-reactive structures in pollen and fruits. METHODS: RAST inhibition was performed to measure cross-reactive IgE to pollen and fruits. The presence of IgE against profilin was determined in a RAST with purified grass profilin, and IgE against carbohydrate structures was determined in a RAST with proteinase K-digested grass pollen extract. The biologic activity of IgE in response to profilin was tested by in vitro histamine release and skin prick tests. RESULTS: IgE against fruits was shown to be largely cross-reactive with grass pollen. The majority of the patients had IgE against profilin (12 of 16) and carbohydrate structures (9 of 10). Profilin was shown to have biologic activity, in both histamine release and skin prick tests. CONCLUSION: Profilin is an important allergen for patients with combined grass pollen/fruit allergy in areas without birch trees.

Adolescent↗
PubMed1995

Selective adverse reactions to diflunisal.

BACKGROUND AND OBJECTIVE: Diflunisal is a difluorophenyl derivative of salicylic acid. We report two patients who presented immediate adverse reactions to diflunisal (Dolobid) that consisted of generalized urticaria and chest tightness. METHODS: Diflunisal was conjugated to human serum albumin in order to perform in vivo and in vitro tests (skin prick and intradermal tests, leukocyte histamine release, and RAST). The patients were challenged following a single-blind, placebo-controlled oral procedure with diflunisal and other nonsteroidal antiinflammatory drugs. RESULTS: Skin tests with diflunisal were negative as were leukocyte histamine release tests and RAST in both patients. They tolerated therapeutic doses of aspirin, salsalate, salicylamide, lysine acetylsalicylate, acetaminophen, dipyrone, and propyfenazone. The oral provocation with diflunisal elicited an immediate response at the cumulative dose of 400 mg in both patients. CONCLUSION: These are two exceptional cases of selective adverse reactions to diflunisal with good tolerance to other salicylates and nonsteroidal antiinflammatory drugs. Thus, the inhibition of cyclooxygenase does not seem to be the mechanism involved. The pathogenic mechanism implicated in the reaction remains unclear, both idiosyncratic and immunologic mechanisms could explain our patients' adverse responses.

Aged↗
PubMed1994

Fixed drug eruption caused by sulfaguanidine.

We report a patient who developed a fixed drug eruption (FDE) due to sulfaguanidine. This drug has not been previously implicated as a cause of FDE. The diagnosis was confirmed by an oral provocation and a biopsy of the lesion. Oral provocations with other sulfonamides, sulfamethoxazole and sulfadiazine, were well tolerated.

Administration, Oral↗
PubMed1992

Respiratory allergy to Aspergillus-derived enzymes in bakers' asthma.

Baking and food industry workers are exposed to several powdered Aspergillus-derived enzymes with carbohydrate-cleaving activity that are commonly used to enhance baked products. We describe a retrospective study of sensitization to fungal alpha-amylase and cellulase on bakers. Five bakers in whom respiratory allergy symptoms developed when they were exposed to bread "improvers" that contained fungal alpha-amylase and cellulase were investigated by in vivo and in vitro tests. Type I hypersensitivity to these enzymes was demonstrated in the five patients by means of skin testing, histamine release test, positive reverse enzyme-immunoassay for specific IgE antibodies, and bronchial provocation test response to alpha-amylase or cellulase or both. Isolated immediate and dual responses to the bronchial challenge tests with these enzymes were observed. Immunoblot analysis with use of a pooled serum identified IgE-binding components in both enzymes. In the reverse-enzyme immunoassay-inhibition assays cross-reactivity between alpha-amylase and cellulase was not found, but some degree of cross-reactivity between alpha-amylase and A. oryzae, and between cellulase and A. niger was demonstrated. Four of the patients were also sensitized to cereal flour. Aspergillus-derived enzymes used as flour additives can elicit IgE-mediated respiratory allergy, and this fact has to be considered in the diagnosis and clinical management of bakers' asthma.

Adolescent↗