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Biomedical subjects

D Zanoni

Publications and source records attributed to D Zanoni.

10 recordsLinked to original sources
PubMed2004

Bee moth (Galleria mellonella) allergic reactions are caused by several thermolabile antigens.

BACKGROUND: Exposure and contact with bee moth (Galleria mellonella) larvae (Gm) can cause an allergic reaction both in anglers and breeders. We described the case of an amateur fisherman who experienced an allergic reaction using Gm but not using heat-treated Gm (h-Gm) (mummies). The aim of this study was to demonstrate by immunoblotting and radioallergosorbent test (RAST)-inhibition experiments the loss of allergenic epitopes in h-Gm extracts. METHODS: Galleria mellonella larvae and h-Gm were homogenized and extracted at 10% (w/v) in 0.5 M phosphate-buffered saline, pH 7.4 containing 0.5% NaN(3) for 16 h at 4 degrees C. Gm and h-Gm extracts were electrophoresed in a 10% polyacrylamide precast Nupage Bis-Tris gel at 180 mA for 1 h and the resolved proteins stained with 0.1% Coomassie brilliant blue and the molecular weight calculated. For the immunoblotting detection of allergenic components the resolved extracts were transferred onto a nitrocellulose membrane and incubated with the patient's serum. Bound specific-IgE was detected by peroxidase-conjugated anti-human IgE. RAST inhibition experiments were performed according to the Ceska method. RESULTS: The protein profile of Gm and h-Gm extracts resulted markedly different in number, intensity and the position of bands, indicating that heat-treatment modifies the chemical-physical characteristics of the protein contents. The Gm extract showed a strong-coloured band at 73 kDa and more than 20 components ranging from 12 to 133 kDa; h-Gm showed two main band at 77 and 38 kDa and about 15 faint bands between 20 and 133 kDa apparently without any correspondence to the bands present in the Gm extract. Immunoblotting with the patient's serum demonstrated several bands of reactivity with the Gm extract ranging from 20 to 100 kDa and no recognizable bands, but only a diffuse smear with h-Gm. When used in a RAST inhibition experiment the h-Gm extract demonstrated an inability to compete with the Gm one for the binding to patient's IgE serum. CONCLUSIONS: The h-Gm seems to lose the allergenic epitopes and has two advantages for anglers: to avoid new possible sensitizations as well as allergic symptoms in sensitized people, without interfering with their skills and satisfaction in their fishing performance.

Adult↗
PubMed2002

Allergenic relevance of Cupressus arizonica pollen extract and biological characterization of the allergoid.

BACKGROUND: Cupressaceae (cypress) pollens can cause pollinosis in winter. However, the lack of specific commercial extracts combined with the early pollination period of cypress trees make a precise diagnosis difficult. The need for a reliable and effective cypress extract for diagnostic and therapeutic purposes is increasingly felt. METHODS: Mixed or single Cupressus arizonica, lusitanica and sempervirens pollen extracts precipitated with ammonium sulfate (PPT) were compared by direct RAST, RAST inhibition and SDS-PAGE techniques. The major allergen of C. arizonica (Cup a 1), purified by anion exchange chromatography, was checked by immunoblotting experiments before chemical modification, in parallel with a C. arizonica extract, with potassium cyanate (KCNO) to obtain a monomeric allergoid. The allergoid extract was characterized for its biological, chemico-physical and immunological features by RAST inhibition, SDS-PAGE and ELISA assays. RESULTS: Direct RAST, RAST inhibition, and SDS-PAGE data indicated that the PPT C. arizonica pollen extract showed the most allergenic potential, and it can be considered representative of the Cupressus spp. Immunoblotting data confirmed Cup a 1 as a major allergen. RAST inhibition and ELISA showed that modified PPT C. arizonica extract had less IgE reactivity than the native, non-modified extract, while preserving the immunogenic capacity typical for an allergoid. Finally, the SDS-PAGE profile of Cup a 1 allergoid was similar to native Cup a 1 allergen, suggesting the modified C. arizonica extract shows the characteristics of a monomeric allergoid. CONCLUSIONS: The PPT C. arizonica pollen extract shows good in vitro diagnostic potential and its chemically modified form offers the features of a monomeric allergoid. It might therefore lend itself to the development of a product to be administered by the sublingual or oromucosal route for immunotherapy of individuals with cypress pollinosis.

Allergens↗
PubMed1996

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.

Allergens↗
PubMed1994

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.

Allergens↗
PubMed1994

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.

Absorption↗
PubMed1993

Distance stereoacuity. Assessing control in intermittent exotropia.

BACKGROUND: A patient's ability to control an intermittent exotropic deviation is usually assessed by subjective means such as observation of control in the office, questioning the patient and/or family about control at home, and reports of monocular eye closure in bright light. An objective method of assessing control has not been developed. PURPOSE: The purposes of this study are to determine if distance stereoacuity was different in patients with intermittent exotropia than in normal subjects and to determine if distance stereoacuity could be used as a objective means of assessing control in intermittent exotropia. METHODS: The authors evaluated near and distance stereoacuity in 44 patients with intermittent exotropia and 50 normal subjects. Patients with intermittent exotropia also were assessed for office control, home control, and monocular eye closure in bright light. Additionally, six patients who underwent successful surgery were reevaluated postoperatively. CONCLUSION: Normal subjects and patients with intermittent exotropia had good near stereoacuity. Patients with intermittent exotropia demonstrated significantly worse distance stereoacuity than the population of normal subjects (P < 0.001). Five of six patients with poor distance stereoacuity preoperatively had dramatic improvement in distance stereoacuity postoperatively. Diminished distance stereoacuity seems to be an objective measure of poor control of the exotropic deviation. This test may provide important objective criteria for deciding when to perform surgery in patients with intermittent exotropia.

Adolescent↗
PubMed1992

A comparison of silver nitrate with erythromycin for prophylaxis against ophthalmia neonatorum.

Although prophylactic eyedrops to treat ophthalmia neonatorum is mandated nationwide, states and hospitals are free to choose specific drugs. To compare two of these agents, we studied the incidence and characteristics of ophthalmia neonatorum in two UCLA teaching hospitals over a five-year period. One, which used 1% silver nitrate solution exclusively, had 50 cases in 34,772 births, a frequency of 0.14%. The other used 0.5% erythromycin ointment exclusively and had 43 cases in 12,652 births, a frequency of 0.34%. Ophthalmia neonatorum was more frequent in the hospital using erythromycin (p less than 0.001), as was chlamydial conjunctivitis (p less than 0.02). Although not statistically significant, gonococcal conjunctivitis was found in four infants, all in the hospital using silver nitrate. Because silver nitrate was found more effective in decreasing the total frequency of all cases of ophthalmia neonatorum, and cases caused by Chlamydia and gram-negative bacteria specifically, this drug still should be considered as a primary prophylactic agent against ophthalmia neonatorum.

Bacteria↗
PubMed1985

High hyperopia in Leber's congenital amaurosis.

Few studies comment on the type of refractive errors found in patients with Leber's congenital amaurosis. The association of an uncomplicated infantile form of this condition with high hyperopia but without systemic complications has been suggested. In a retrospective study, we identified 11 patients who satisfied the criteria for the diagnosis of this subtype of Leber's congenital amaurosis. All of our cases were found to have at least +6.00 diopters of hyperopia on cycloplegic refraction. No systemic abnormalities were found in any of these children. We suggest that high hyperopia be included in the diagnostic criteria of this specific form of Leber's congenital amaurosis.

Blindness↗
PubMedDate not supplied

A new method for evaluating distance stereo acuity.

A new standardized method for evaluating distance stereo acuity has been developed, using the graphic capacity of a high-frequency microprocessor and liquid crystal binocular glasses. Images are alternately presented at a frequency of 60 cycles per second to each eye, using synchronized liquid crystal shutter glasses. The amount of disparity in the stereo patterns can be altered to allow a measurement as refined as 15 seconds of arc ("). This instrument is now commercially available as part of the Mentor B-Vat system. We evaluated distance Random Dot and Contour circle stereo acuity of 50 normal subjects using this new method and compared these results to conventional Titmus and Randot circles at near. The distance stereo acuity mean results were 139" for the Random Dot test and 41.1" for the Contour circles. The near stereo acuity results were 41.8" for the Titmus circles and 27" for the Randot circles. Statistically, the Titmus results at near can be compared to the Contour circles at distance. The distance Random Dot test results demonstrate much less stereoability than the other test. The application of these new distance stereotests will be discussed.

Adolescent↗