Biomedical subjects
G Mistrello
Publications and source records attributed to G Mistrello.
Intraoral and respiratory allergy to Eruca sativa (Cruciferae family) in a subject with sensitization to pollen allergens.
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Dot immunobinding assay for detection of mite antigens in house-dust samples.
A new test was developed specifically to detect mite antigens in house-dust. It uses a nitrocellulose dipstick spotted with specific antimite antibodies that act as a capture matrix; the same antibodies act as a detecting reagent when conjugated with colloidal dye particles. Aclotest is a 1-step assay, where a spotted dipstick is placed in a tube containing the detecting reagent and the house-dust sample. No instrumentation or previous extraction procedure of the sample is required, and the test response is visible as a colored spot, after 1 h incubation. The sensitivity and specificity of the new test were compared with those of Acarex and Der p1/Der f1 ELISA tests.
Cross-reactivity between latex and sweet pepper due to prohevein.
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Absorption and distribution kinetics of the major Parietaria judaica allergen (Par j 1) administered by noninjectable routes in healthy human beings.
BACKGROUND AND OBJECTIVE: The clinical effectiveness of noninjectable routes for specific immunotherapy has been demonstrated in many studies, but no data are available on the kinetics of allergens administered by these routes. Therefore we studied the kinetics of the radiolabeled purified major Parietaria judaica allergen (Par j 1) after sublingual, oral, and intranasal administration to healthy human beings. METHODS: After tracer administration (10 to 12.5 microg of Par j 1 labeled with iodine 123) to nonallergic volunteers, scintigraphic images were recorded at various times. Blood samples were also obtained at serial intervals to evaluate the absorption and distribution of radioactivity in plasma and to identify circulating radioactive species by molecular exclusion gel chromatography. RESULTS: When the sublingual route was used, no circulating radioactivity was detected until the tracer was kept under the tongue. The labeled allergen was rapidly degraded and absorbed in the gastrointestinal tract after swallowing. Plasma radioactivity peaked at about 1.5 to 3 hours and was mostly represented by free radioiodine and small radiolabeled peptides. Some activity not caused by free 123I remained associated with the oral mucosa up to 18 to 20 hours after administration. When the oral route was used, the results were similar to those observed after swallowing the sublingually administered allergen but without any persistence of the tracer in the mouth. When the intranasal route was used, the pattern of plasma radioactivity mimicked that of the sublingual and oral routes, with absorption of activity from the radiolabeled allergen occurring in the gastrointestinal tract after transport to the pharynx by mucociliary clearance. A relevant fraction of the tracer was retained on the nasal mucosa up to 48 hours after administration. CONCLUSION: The data in this study provide the first experimental basis for exploring the in vivo kinetics of allergen administered through noninjectable routes for specific immunotherapy in human beings.
Oral allergy syndrome from pork.
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Exercise-induced egg anaphylaxis.
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Pharmacokinetics of allergens after local administration.
The authors review the status of knowledge on absorption and kinetic of allergens administered on nasal mucosa. Intranasal administration is well known in pharmacology, and has been used for a long time for peptide drugs, mainly hormones. The immunological response to intranasally administered antigens have been studied in some experimental models: bovine Rnase, dextran, KLH, tetanus toxoid. These studies showed in atopic people a greater absorption of antigens by nasal mucosa compared to normal individuals, a difference that might be of importance in the pathogenesis of atopic diseases. The absorption rate of peptides through nasal mucosa has been studied biologically by PK-test with Rnase and peanut allergen, and a consistent passage of intact molecules has been observed. Using as tracer 125I-labelled human albumin, transport across the nasal mucosa has been demonstrated in 3/9 normal subjects, 1/9 patients with extrinsic asthma and 9/10 patients with atopic rhinitis. In experimental animals (rabbits) the passage of allergens through the nasal mucosa has been confirmed using 125I-labelled Parietaria allergens that showed a peak in the bloodstream 60 min after administration. It is concluded that peptide molecules such as allergens can be absorbed through the nasal mucosa and reach the bloodstream, and that in atopic patients nasal permeability is enhanced.
Oral routes for immunotherapy: clinical efficacy and kinetics of the allergen.
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Comparison between outdoor and indoor airborne allergenic activity.
BACKGROUND: Allergenic pollens are usually detected in outdoor air by using volumetric spore traps, which allow measurement of atmospheric concentration as pollen grains per m3 of air. The results of the pollen count are useful primarily for outdoor environments while most people spend most of the day indoors. OBJECTIVE: The purpose of our study was to compare outdoor pollen levels with allergenic activity measured both outdoors and indoors. METHODS: We used a Lanzoni spore trap to measure airborne Urticaceae pollen and filters collecting particles simultaneously indoors and outdoors and assayed each filter for Parietaria judaica allergenic activity. Samples were collected at the Allergological Service of the "A. Cardarelli" Hospital in Naples with the balcony open on some days and closed on others. Allergenic activity (ng/m3) was measured using the immunocapture RAST. RESULTS: With the balcony open there was no great difference between outdoor and indoor allergenic activity, but with the balcony closed there was a reduction of indoor allergenic activity of about one-third in comparison with outdoor allergenic activity. Statistical analysis (Pearson correlation test) indicated a significant correlation between outdoor allergen levels and indoor allergen levels with the balcony open (r = .4415, P < .05), but not with the balcony closed (r = .3160, P > .05); a significant correlation between outdoor pollen count and indoor allergen levels with the balcony open (r = .4809, P < .05), but not with the balcony closed (r = .3858, P > .05); and a highly significant correlation (r = .5225, P < .001) between outdoor pollen count and outdoor allergen levels. CONCLUSIONS: These data provide scientific evidence for the recommendation to hay fever patients to remain indoors during seasons with high levels of outdoor pollens.
Oral allergy syndrome (OAS) in pollinosis patients after eating pistachio nuts: two cases with two different patterns of onset.
We describe two uncommon cases of oral allergy syndrome (OAS) after eating pistachio nuts (p.n.) in subjects (a 54-year-old man and a 3-year-old girl) with exclusive skin prick test (SPT) positivity to Parietaria (P.) and pistachio nut (p.n.) allergens. Serologic P.- and p.n.-specific IgE determinations were also carried out. A double-blind, placebo-controlled food challenge (DBPCFC) was performed, for ethical reasons, only in the adult patient, but we observed a positive intraoral reaction only after slight scratching of the oral mucosa. Since this patient had put three whole p.n. with their shells into his mouth, breaking them with his teeth, before the onset of symptoms, we suggest that slight injury of the oral mucosa may enhance the local response. Preliminary results with SDS-PAGE and immunoblotting demonstrate the occurrence of a slight degree of cross-reactivity between these allergens, but further studies are necessary to obtain a definite conclusion.
Monomeric chemically modified allergens: immunologic and physicochemical characterization.
Allergenic extracts (Der p, grass, and Parietaria) or single allergens such as Par j I (the major allergen of Parietaria) and ovalbumin (OA), a food allergen widely used in animal models, were chemically modified by reaction with potassium cyanate (KCNO), which transforms the epsilon-amino group of the lysine of proteinaceous allergens into ureido groups. KCNO-modified (carbamylated) allergens have low allergenic potency, as demonstrated in vitro (RAST inhibition) and in vivo (passive cutaneous anaphylaxis). When used to immunize rabbits, carbamylated allergens still induce IgG antibodies able to cross-react with native allergens (immunoblotting experiments). An interesting feature distinguishing carbamylated allergens from other chemically modified allergens is the preservation of the native monomeric dimension as demonstrated by SDS-PAGE analysis. Results are discussed from the perspective of clinical application of carbamylated allergens.
Evaluation of allergenic potency by REAST inhibition. A new tool for the standardization of allergenic extracts.
The potency of allergenic extracts can be determined in vitro by RAST inhibition, and this has become the preferred method for the standardization of allergens. A disadvantage of this technique is the impossibility of obtaining data about allergens bound to the solid phase, i.e., the counterpart of the inhibiting extract. The REAST (reverse enzyme allergosorbent test) is based on the capture of IgE by a specific antibody bound to microtiter wells, the reaction of captured IgE with biotinylated allergen and the development of a colour reaction by subsequent addition of streptavidin-peroxidase and chromogenic substrate. The addition of an allergen extract in a dose-response fashion competes with the biotinylated allergen and inhibits the test. In the present study REAST inhibition has been evaluated with Dermatophagoides pteronyssinus, Parietaria judaica and mixed grass pollen extracts. The correlation of REAST inhibition with RAST inhibition and both intra-assay and inter-assay reproducibility have been evaluated. REAST inhibition is a potentially valuable new tool for the standardization of allergenic extracts.
cDNA cloning, expression and primary structure of Par jI, a major allergen of Parietaria judaica pollen.
A 659 bp cDNA clone** coding for an allergen of Pj pollen has been isolated from a lambda gt11 library, and its DNA sequence determined. The cDNA insert showed an open reading frame of 429 bp coding for an allergenic protein of 14,866 Da and a deduced amino acid sequence containing 143 residues. The expressed recombinant protein represented the major allergen Par jI since it reacted with 95% of the sera from Pj-allergic patients (n = 22) and with two Par jI-specific monoclonal antibodies. No similarity with other known DNA and protein sequences has been detected.
Modified par j I allergen from P judaica pollen and its rate of absorption in rats.
Polymerized allergens (allergoids) have been introduced in the immunotherapy of allergic disease in order to reduce the risk of side effects. However, their high molecular weight can be a limit, particularly when they are administered by a route involving passage through the mucosal barrier. We describe a simple procedure aimed at developing an original modified allergen with significantly less allergenic potential (intended as human IgE-binding capacity) but preserving the monomeric nature of the molecule. Par j I, the major allergen of Parietaria judaica pollen, was purified by a combination of monoclonal antibodies and affinity chromatography. Par j I allergen was then modified by reaction with potassium cyanate (KCNO), and compared with the native allergen to evaluate its allergenic potency (RAST-inhibition) and molecular weight (SDS-PAGE). Modified allergen showed significantly lower allergenic potency but kept its original molecular weight, making it particularly suitable for buccal (sublingual) administration. To study the adsorption profile, modified Par j I was radiolabeled and administered intravenously and sublingually to normal rats. The prospects for clinical application of the modified allergen are discussed.
Detection of Parietaria judaica airborne allergenic activity: comparison between immunochemical and morphological methods including clinical evaluation.
Airborne pollen grains and small plant particles of respirable size are the main causes of rhinitis and asthma in pollinosis patients. Consequently, it could be useful to quantify atmospheric variations in these biological aerosols and their allergenic activity as a basis for establishing correlations with the clinical symptoms in these allergic subjects. Our study was conducted in Naples from May to August 1992 and from May to August 1993 and concentrated on Parietaria judaica (Par j) the most important hay fever-provoking plant in southern Italy. The aim of this study was to evaluate the day-to-day variation in counts of Par j. pollen, the day-to-day variation in allergenic activity specific for this plant, and to relate these two variables to symptom scores in patients with respiratory allergy to Par j. The airborne pollen grains were collected by a Hirst-like volumetric trap and examined through an optical microscope, while the allergenic activity of particles trapped on glass fibre filters in a high volume air-sampler was determined by immunochemical assay. The two devices were placed on the flat roof of the 'A. Cardarelli' Hospital. The results of this preliminary study suggest that both methods could have useful clinical relevance, since these two biological parameters were significantly correlated with the symptom scores of allergic patients. However, pollen count with morphological quantification of grains/m3 of air is a more simple technique.
Purification of Phleum pratense pollen extract by immunoaffinity chromatography and high-performance ion-exchange chromatography.
Basic allergens of Phleum pratense pollen extract have been purified by either sequence gel filtration-ion-exchange high-performance liquid chromatography (HPIEX) and size-exclusion HPLC or sequence gel filtration-immunoaffinity chromatography and HPIEX. The second procedure seems to be suitable for preparative purposes.