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Biomedical subjects

P Tornero

Publications and source records attributed to P Tornero.

At least 19 recordsLinked to original sources
PubMed2001

Anisakis simplex-sensitized patients: should fish be excluded from their diet?

BACKGROUND: Anisakis simplex (A.s.) allergy is an emerging disease. The third-stage larvae of this nematode are a source of hidden allergens in fish. There are no clear guidelines concerning dietary restrictions for patients with serum-specific IgE to this parasite. OBJECTIVE: To follow up the clinical data and immunological parameters of patients sensitized to A.s. during 6 to 23 months. METHODS: The clinical symptoms and serologic status of 17 patients with specific IgE and positive skin prick test results to A.s. were studied prospectively. Six of these had anaphylaxis (ANA) attributed to A.s. and 11 patients experienced concomitant chronic urticaria (CU). All patients were advised not to eat fish for 6 months. RESULTS: Four patients from the ANA group excluded fish, and ANA did not recur. Two other patients with ANA refused to exclude fish; one remained free of symptoms and the other experienced several urticarial episodes. During this 6-month period total IgE levels decreased in all six ANA patients; specific IgE for A.s. decreased in four patients and increased in two. Two patients from the CU group did not exclude fish, and symptoms persisted in these two patients. Clinical improvement was observed in 78% of the patients with CU who excluded fish. Total and specific IgE levels decreased in all the patients with CU. CONCLUSIONS: Because ANA symptoms are very severe, patients should always be advised to exclude fish until specific food allergens are identified. However, in patients with CU and specific IgE to A.s., only the clinical response to fish ingestion will determine the need for strict fish avoidance.

Adult↗
PubMed2001

Occupational asthma caused by exposure to cyanoacrylate.

BACKGROUND: Exposure to acrylates may give rise to rhinitis and asthma in both industrial and domestic environments. The mechanisms underlying these respiratory conditions caused by acrylates remain largely unknown. METHODS: We studied two assembly operators exposed to cyanoacrylate glue who developed rhinitis and asthma symptoms. The causal relationship of these symptoms to cyanoacrylate glue exposure was investigated by serial peak expiratory flow (PEF) monitoring at work and off work. Moreover, inhalation testing was performed by asking the patients to mimic exposure at work with the cyanoacrylate glue in a 7-m3 challenge chamber. RESULTS: Serial PEF monitoring at work and away from work was consistent with occupational asthma in both patients. The methacholine inhalation test was negative in patient 1 (off work) and showed bronchial hyperresponsiveness in patient 2. After 20-min exposure to cyanoacrylate, the patients had late and progressive asthmatic reactions, respectively, and the methacholine test became positive in patient 1. Induced-sputum samples obtained 3 and 24 h after the cyanoacrylate challenge showed a marked increase in sputum eosinophils. CONCLUSION: Exposure to cyanoacrylate in these patients provoked not only variable airflow limitation and bronchial hyperresponsiveness, but also pronounced eosinophilia in sputum.

Adult↗
PubMed2001

Bezafibrate-induced anaphylactic shock: unusual clinical presentation.

We report a case of a patient who suffered generalized urticaria, chest tightness, wheezing, nausea, vomiting, hypotension, and loss of consciousness. Two hours earlier she had taken Eulitop Retard following lunch. She had tolerated all the implicated food after the reaction. Allergy evaluation revealed intense positive responses to intradermal tests with bezafibrate active component and Eulitop Retard (skin tests in control subjects were negative). Specific IgE tests (RAST) to Eulitop Retard were negative. An IgE mechanism is suggested to be responsible for this adverse reaction on the basis of the positive skin tets. The delayed onset (two hours) of this anaphylactic shock is unusual. Although infrequent, it may be caused by the specific pharmacokinetic characteristics of this drug, which is a slow releasing agent, mainly absorbed in the gut. The drug was taken just after lunch, and this concomitant food ingestion could also have produced a delay in gastric drainage and a retarded drug absorption. An IgE-mediated accelerated type reaction could also explain this delay. Apparently the patient reacted after the first contact to the drug, and the absence of a sensitization period is not usual in this type of immune reponse. Finally, we recommend the performance of prick and intradermal skin tests prior to any systemic challenge when allergic reactions to fibric acid derivatives are suspected.

Anaphylaxis↗
PubMed1999

Lupine-induced anaphylaxis.

BACKGROUND: Legumes are one of the most common foods causing allergic reactions in children and adults. Cross-reacting antibodies are frequently demonstrated in this family but the real clinical cross-reactivity is uncommon. OBJECTIVE: To report a case of lupine-induced anaphylaxis and to elucidate in vivo and in vitro cross-reactivity with some legumes. METHODS: Skin prick test (SPT) with some legumes were performed. Cap-IgE, ELISA-IgE, and immunoblotting were carried out. Open oral challenges with some legumes were performed. Cross-reactivity was studied by ELISA and immunoblotting inhibition. RESULTS: The results demonstrated type-I hypersensitivity reactions with lupine and some other legumes. Cap-IgE with peanut was positive but the SPT and ELISA-IgE were negative and the patient tolerated a peanut challenge. ELISA inhibition revealed a partial inhibition (62%) using lupine as the solid phase. Partial inhibition was demonstrated by immunoblotting inhibition. Open oral challenge with peanut and green bean were negative but positive with pea. CONCLUSION: We present a lupine sensitized patient with positive SPT and in vitro cross-reactivity with other legumes. Clinical cross-reactivity progressively developed over a 5-year period. Discrepancies were found between the clinical aspect and in vitro study of peanut allergy. Factors determining the wide variability in cross-reactivity among individuals are still obscure.

Adult↗
PubMed1999

A tomato homeobox gene (HD-zip) is involved in limiting the spread of programmed cell death.

Antisense suppression in transgenic tomato plants of H52, a gene encoding a new homeodomain protein of the HD-Zip class, produces a conditional lethal phenotype. The transgenic lines that survive exhibit spontaneous misregulation of cell death control in leaves, which, once initiated, propagates and engulfs the entire leaf. Activation of defence genes, over-accumulation of ethylene and conjugated salicylic acid, and growth reduction of virulent pathogens also occurs in these plants. In wild-type plants, H52 is up-regulated upon infection, mirroring the generation of the oxidative burst which normally precedes the hypersensitive response (HR). Thus, H52 appears to be a transcription factor involved in cellular protection by limiting spread of programmed cell death in plants.

Amino Acid Sequence↗
PubMed1998

Fluorescein-induced allergic reaction.

BACKGROUND: Adverse reactions following intravenous sodium fluorescein are very unusual and their mechanism is still uncertain. We report the case of a patient who suffered an adverse reaction during a fluorescein ocular angiography. Positive allergy tests to fluorescein suggest an IgE-mediated mechanism. OBJECTIVE: Report the allergy evaluation performed in a patient who suffered an adverse reaction during an intravenous fluorescein administration. METHODS: We selected the case of a patient who suffered dizziness, diaphoresis, generalized pallor, nausea, sphincter relaxation, hypotension, and intense malaise during a fluorescein ocular angiography and compared the results to other nonreactive subjects. Allergy evaluation: Prick and intradermal skin tests and serial determinations of serum tryptase were performed on the patient and four control subjects who underwent and tolerated the same procedure as well as on a patient who developed an intense vagal reaction during blood extraction. RESULTS: Positive skin tests and dramatic increase of serum tryptase (67U/I) were observed in our patient. The rest of the patients had negative skin tests and did not have any variation in their serum tryptase. CONCLUSIONS: An IgE-mediated mechanism is suggested as responsible for this adverse reaction. We recommend that a complete allergy evaluation should be performed in all patients who have adverse reactions to fluorescein in order to differentiate true allergic reactions from other types of reactions.

Aged↗
PubMed1997

Identification of a new pathogen-induced member of the subtilisin-like processing protease family from plants.

By using biochemical, immunological, and molecular strategies we have identified and cloned a cDNA encoding a protease from tomato (Lycopersicon esculentum) plants (P69B) that is part of a proteolytic system activated in the plant as a result of infection with citrus exocortis viroid. This new protease is closely related, in terms of amino acid sequence and structural organization, to the previously identified pathogenesis-related subtilisin-like protease (Tornero, P., Conejero, V., and Vera, P. (1996) Proc. Natl. Acad. Sci. U. S. A. 93, 6332-6337). The 745-residue amino acid sequence of P69B begins with a cleavable signal peptide, contains a prodomain and a 631-residue mature domain which is homologous to the catalytic modules of bacterial subtilisins and eukaryotic Kex2-like proteases. Within the catalytic domain, the essential Asp, His, and Ser residues that conform the catalytic triad of this family of proteases are conserved in P69B. Northern blot and reverse transcriptase-polymerase chain reaction analysis demonstrated widespread induced expression of the 2.5-kilobase hybridizing mRNA in plant tissues as a consequence of viroid infection. We propose that P69B is a member of a complex gene family of plant Kex2/subtilisin-like proteases presumably involved in a number of specific proteolytic events activated during pathogenesis in plants and that takes place in the extracellular matrix.

Amino Acid Sequence↗
PubMed1997

Two PR-1 genes from tomato are differentially regulated and reveal a novel mode of expression for a pathogenesis-related gene during the hypersensitive response and development.

Pathogenesis-related (PR) proteins form a heterogeneous family of plant proteins that are likely to be involved in defense and are inducible by pathogen attacks. One group of PRs, represented by the subfamily PR-1, are low-molecular-weight proteins of unknown biochemical function. Here we describe the cloning and characterization of two closely related genes encoding a basic and an acidic PR-1 protein (PR1b1 and PR1a2) from tomato (Lycopersicon esculentum). We present a comparative study of the mode of transcriptional regulation of these two genes in transgenic tobacco plants using a series of promoter-GUS fusions. Unexpectedly, the chimeric PR1a2/GUS gene is not induced by pathogenic signals but instead shows constitutive expression with a reproducible developmental expression pattern. It is expressed in shoot meristems, trichomes, and cortical cells as well as in vascular and nearby tissues of the mature stem. This constitutive expression pattern may represent preemption of plant defenses against potential pathogens. Conversely, the chimeric PR1b1/GUS gene does not show any constitutive expression in the plant, but it is transcriptionally activated following pathogen attack. Upon infection by tobacco mosaic virus, the PR1b1 gene is strongly activated locally in tissues undergoing the hypersensitive response but not systemically in uninoculated tissues. Furthermore, its expression is induced by both salicylic acid and ethylene precursors, two signals that coexist and apparently mediate the activation of local defenses during the hypersensitive response. We speculate that the different mode of expression of the two genes presented here, together with that reported previously for the induction of other PR-1 genes in systemic, uninoculated tissues, may all be complementary and necessary for the plant to acquire an efficient refractory state to resist pathogen attacks.

Amino Acid Sequence↗
PubMed1997

Serum tryptase levels in adverse drug reactions.

We evaluated the usefulness of individual tryptase levels and variations after adverse drug reactions in 64 patients. Our aim was to find a tool for the diagnosis of drug allergy. Thirty-seven subjects were confirmed to have drug allergy, 12 had nonsteroidal anti-inflammatory drug (NSAID) reactions, five had negative controlled drug challenges (NAAR), and 10 had symptoms after placebo intake (PLA). Serum tryptase levels greatly increased after anaphylactic shocks (2242%) and anaphylaxis (710.5%). Patients with allergic urticaria and those with idiosyncratic responses to acetylsalicylic acid (ASA) exhibited a small increase in serum tryptase (49.5% and 38.2%, respectively). In the other two groups (NAAR and PLA), no variation in this serum protease was observed. The time of appearance of the serum tryptase peak differed considerably among patients with similar clinical reactions (from 30 min to 6 h) and was independent of the latent period, severity of symptoms, or the amount of tryptase released. We conclude that serum tryptase determinations are helpful in the diagnosis of anaphylactic shock and anaphylaxis, but serial measurements may be needed to confirm mast-cell participation in milder reactions.

Anaphylaxis↗
PubMed1996

Primary structure and expression of a pathogen-induced protease (PR-P69) in tomato plants: Similarity of functional domains to subtilisin-like endoproteases.

A 69-kDa proteinase (P69), a member of the pathogenesis-related proteins, is induced and accumulates in tomato (Lycopersicon esculentum) plants as a consequence of pathogen attack. We have used the polymerase chain reaction to identify and clone a cDNA from tomato plants that represent the pathogenesis-related P69 proteinase. The nucleotide sequence analysis revealed that P69 is synthesized in a preproenzyme form, a 745-amino acid polypeptide with a 22-amino acid signal peptide, a 92-amino acid propolypeptide, and a 631-amino acid mature polypeptide. Within the mature region the most salient feature was the presence of domains homologous to the subtilisin serine protease family. The amino acid sequences surrounding Asp-146, His-203, and Ser-532 of P69 are closely related to the catalytic sites (catalytic triad) of the subtilisin-like proteases. Northern blot analysis revealed that the 2.4-kb P69 mRNA accumulates abundantly in leaves and stem tissues from viroid-infected plants, whereas the mRNA levels in tissues from healthy plants were undetectable. Our results indicate that P69, a secreted calcium-activated endopeptidase, is a plant pathogenesis-related subtilisin-like proteinase that may collaborate with other defensive proteins in a general mechanism of active defense against attacking pathogens.

Amino Acid Sequence↗
PubMed1996

Characterization of LRP, a leucine-rich repeat (LRR) protein from tomato plants that is processed during pathogenesis.

This paper describes the isolation and characterization of LRP, a new gene from tomato plants. The deduced amino acid sequence showed that the encoded protein is enriched in leucine, and contains interesting structural motifs. LRP contains four tandem repeats of a canonical 24 amino acid leucine-rich repeat (LRR) sequence present in different proteins that mediates molecular recognition and/or interaction processes. Genomic organization and intron-exon arrangement of LRP favor the hypothesis that the LRR domains present in LRP evolved by exon duplication and shuffling. LRP expression analysis and immunohistochemical localization studies of the encoded protein indicate that the gene is under developmental regulation exhibiting tissue-specificity, particularly in certain cell types of the stele, like phloem fibers, parenchyma cells of the protoxylem, and in the cell files that constitute the rays of the secondary xylem. It is shown that this gene is upregulated in diseased tomato plants infected with citrus exocortis viroid. However, in this pathogenic context, LRP is processed proteolytically to a lower molecular weight form by a host-induced extracellular protease. The structural characteristics of LRP, its spatio-temporal pattern of expression, and its post-translational processing during pathogenesis, suggest this protein as a candidate molecule that may mediate recognition and interaction events taking place in the plant extracellular matrix under normal and/or pathogenesis-related conditions.

Amino Acid Sequence↗
PubMed1996

Phloem-specific expression of a plant homeobox gene during secondary phases of vascular development.

This paper reports the isolation and characterization of a homeobox gene (VAHOX1) from Lycopersicon esculentum encoding a homeodomain protein that contains a leucine zipper motif. The bipartite homeodomain-leucine zipper (HD-Zip) motif has only been found in homeobox genes from dicotyledonous plants, indicating that this type of transcription factor regulates particular developmental processes in these plant species. Here, the genomic organization, sequence comparison and expression analysis of VAHOX1 are described. Transcriptional fusion of the 5' promoter region of VAHOX1 with the reporter GUS gene (VAHOX1-GUS) and expression analysis of this construct in transgenic plants indicates that VAHOX1 is specifically expressed in the phloem during phases of secondary growth. Unlike other plant homeobox genes, VAHOX1 does not appear to be expressed in meristems, and the function of VAHOX1 is considered a likely candidate molecule that may participate in the regulation of the identity and/or activity of phloem tissues during secondary phases of vascular development.

Amino Acid Sequence↗
PubMed1994

A gene encoding a novel isoform of the PR-1 protein family from tomato is induced upon viroid infection.

A Lycopersicon esculentum cDNA clone encoding an acidic-type pathogenesis-related protein (PR-1a1) was isolated, sequenced and characterized. It contains an open reading frame of 175 amino acids and the mature protein, after cleavage of the 21 amino acid signals peptide, has a pI of 5.24. The protein shows highest homology (75% identity) with the basic pathogenesis-related prb-1b protein from tobacco. The PR-1a1 gene shows constitutive expression in roots from tomato plants. It is expressed in leaves and stems upon viroid infection, and appears to be induced by ethylene. Comparative studies of this gene and a related basic isoform of PR-1 indicate that the expression of these two members of the PR-1 gene family in tomato may be differentially regulated upon viroid infection.

Amino Acid Sequence↗