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Biomedical subjects

G Mistrello

Publications and source records attributed to G Mistrello.

51 records · Page 3Linked to original sources
PubMed1991

Allergenic fragments in Parietaria judaica pollen extract.

High-performance ion-exchange chromatography and immunoaffinity chromatography suggest that Par jI, the principal allergenic component of Parietaria judaica pollen, is a very unstable molecule, which tends to fragment in solution. Several fragments were obtained from Par jI and some of them show positivity toward the anti-Par jI monoclonal antibody, suggesting that they retain the entire structure of the allergenic determinant. These fragments could be the target for sequence and conformation studies.

Allergens↗
PubMed1991

Detection of IgE-binding activity in serum after intranasal treatment of normal rabbits with P. judaica extract.

Local intranasal immunotherapy relieves the allergic symptoms of rhinitic patients but little is known about the absorption and distribution of inhaled allergens in the body. The aim of this study was to establish whether allergenic proteins are able to reach the bloodstream by penetrating through the nasal mucosa when aqueous P. judaica extract was administered into the nostrils of normal rabbits. Optimal conditions for a sensitive modified RAST (immunocapture RAST) were set up and the method was used to detect clinically relevant allergenic activity in the systemic circulation. The kinetic profile after intranasal treatment was compared with the profile after intravenous injection of the allergenic extract. The findings are discussed in relation to the mechanism by which local immunotherapy acts.

Administration, Intranasal↗
PubMed1991

Inhaled furosemide prevents both the bronchoconstriction and the increase in neutrophil chemotactic activity induced by ultrasonic "fog" of distilled water in asthmatics.

Inhaled furosemide has been shown to prevent bronchoconstriction induced by inhalation of ultrasonic nebulization of distilled water (UNDW) in bronchial asthma. To evaluate whether inhaled furosemide also prevents the increase in serum neutrophil chemotactic activity (NCA) observed during UNDW bronchoconstriction, we measured NCA during UNDW challenge without (control) and immediately after inhalation of furosemide (40 mg) or placebo (saline) in 10 asthmatics responsive to UNDW, in a randomized, double-blind study. NCA was assessed by measuring the maximal distance reached by neutrophils in a filter when challenged with the subject serum in a Boyden chamber ("leading front"). UNDW inhalation produced a significant increase in NCA in each subject. Gel filtration chromatography on S400 column indicated that the NCA released were 600 to 700 kD. Saline had no effect on bronchoconstriction nor on NCA increase induced by UNDW in nine patients. Furosemide did not change baseline FEV1, but it prevented bronchoconstriction and NCA increase in nine patients. In the whole group the maximal decrease in FEV1 after UNDW was -31.1%, SEM 4.7 after saline and -7.5%, SEM 5.2 after furosemide, p less than 0.001, the maximal increase in NCA after UNDW was +52.9%, SEM 9.2 after saline and +3.8%, SEM 3.1 after furosemide, p = 0.001. These results indicate that inhaled furosemide prevents both the bronchoconstriction and the NCA increase induced by UNDW inhalation in most asthmatic patients. This finding adds support to the suggestion that furosemide acts on mast cells.

Administration, Inhalation↗
PubMed1985

Contragestational profile of the tumor-inhibiting agent, L-alanosine, in the rat and the hamster.

L-Alanosine [L-2-amino-3(N-hydroxy-N-nitrosamino)propionic acid], a tumor-inhibiting agent, induces pregnancy arrest after single or multiple SC or PO administration to rats and hamsters. Its contragestational effects are dose- and route-dependent, with no important differences in species-sensitivity or administration schedules. L-Alanosine is maximally effective shortly (3-4 days) after implantation. Both placenta and fetus appear to be target tissues. Consistent with previous in vitro findings, adenine but not aspartic acid counteracts the contragestational action of L-alanosine. The 'contragestational test', i.e., the effect on conceptus growth, appears to be an interesting approach for learning more about the antiproliferative activity of an antineoplastic agent.

Adenine↗
PubMed1985

Immunological profile of DL111-IT, a new immunosuppressant agent.

The immunosuppressive properties of the non-hormonal contragestional agent 3-(2-ethylphenyl)-5-(3-methoxyphenyl)-1H-1,2,4-triazole (DL111-IT) were evaluated on different immunological functions. The compound displayed significant immunosuppressive activity on both humoral and cellular immunity when administered during the inductive phase of the immune response. In experimental models autoimmunity and skin transplantation, DL111-IT was able to reduce the production of auto-antibodies and prolong skin graft survival. The compound, even at doses much higher than those effective inhibiting immune responses, did not influence the survival time of some haematological tumors in mice. This suggest that DL111-IT does not act by a general cytotoxic mechanism.

Animals↗
PubMed1984

Effect of L-alanosine on immune response.

L-alanosine is an antitumor compound which has recently entered clinical trials. Single i.p. doses of this drug inhibit antibody production to thymus-dependent and thymus-independent antigens as well as delayed hypersensitivity to SRBC in mice. Moreover, the in vitro lymphoproliferative responses of splenocytes to Concanavalin A and bacterial Lipopolysaccharides are also affected when the drug is added upon setting up the cultures. On the other hand, in vivo treatment with L-alanosine does not impair spleen natural killer (NK) activity. The results are discussed in an effort to characterize the immuno-suppressive activity of L-alanosine.

Alanine↗
PubMed1978

Suppression of mitogen responses and graft-versus-host reaction by splenocytes from mice bearing Lewis lung carcinoma.

The presence of suppressor cells in the spleens of C57BL/6 mice bearing Lewis lung carcinoma was investigated with the use of the in vitro lymphoproliferative response to mitogens and the graft-versus-host reaction (GVHR) as test systems. Splenocytes from tumor-bearing mice showed a lower response to mitogens when obtained 15-27 days after tumor transplant. In parallel, these cells were capable of suppressing the response of normal spleen cells to mitogens and their capacity to mount a GVHR in allogeneic hosts. Treatments with procedures known to remove adherent phagocytes, but not treatments with anti-Thy 1.2 serum plus complement, removed the suppressive activity observed.

Animals↗
PubMedDate not supplied

Dot immunobinding assay as a new diagnostic test for human hydatid disease.

Bovine and human hydatid antigens collected from hepatic cysts and characterized by SDS-PAGE immunoblotting show similar patterns. The bovine hydatid antigen has been used to develop a simple and fast in vitro diagnostic assay for human hydatidosis. This method, named HA-DIA (hydatid antigen dot immunobinding assay), consists of incubation of a serum sample with a textile colloidal dye (pink) and a nitrocellulose stick to which the hydatid antigen has been bound. The presence of parasite-specific antibodies leads to dyeing of the stick reactive area, and a coloured spot appears. HA-DIA sensitivity and specificity have been studied in comparison with RAST-IgE and ELISA-IgG by testing 17 sera of patients with hydatid disease and 36 control sera from patients affected with other parasitic and non-parasitic diseases. HA-DIA showed positive results in all the patients' sera and in none of the control sera. Correlation with ELISA--IgG and RAST-IgE was significant. HA-DIA has been demonstrated to be of good predictive value, allowing a speedy diagnosis of hydatid disease. In view of its simplicity, not requiring any laboratory instruments, it is particularly suitable for large-scale field screening.

Animals↗
PubMedDate not supplied

Lipid transfer protein: a pan-allergen in plant-derived foods that is highly resistant to pepsin digestion.

BACKGROUND: Lipid transfer proteins (LTPs) are stable and highly conserved proteins of around 10 kD. They have recently been identified as allergens in fruits of the Rosaceae family. OBJECTIVE: The aim of this study was to investigate whether the highly conserved structure of LTPs justifies a designation as a true pan-allergen, and to study the role of protein stability in allergenicity. METHODS: Thirty-eight patients with a positive skin prick test to Rosaceae fruit extracts were characterized by interviews and skin prick tests. To investigate IgE cross-reactivity between Rosaceae and non-Rosaceae LTPs, RAST and RAST inhibition as well as ELISA and ELISA inhibition were performed, using whole food extracts and purified natural and recombinant LTPs. To address the role of protein stability in the allergenicity of LTP, fruit extracts and LTPs were digested with pepsin. RESULTS: IgE antibodies to Rosaceae LTPs cross-reacted with a broad range of non-Rosaceae vegetable foods. Inhibition studies with purified natural and recombinant LTPs confirmed the role of LTP in this cross-reactivity. Many of the patients with this type of cross-reactive IgE antibodies had a clinical food allergy. In contrast to the typical birch Rosaceae cross-reactive patients, the oral allergy syndrome was frequently accompanied by more severe and systemic reactions. IgE reactivity to LTP was shown to be resistant to pepsin treatment of the allergen. CONCLUSION: LTP is a true pan-allergen with a degree of cross-reactivity comparable to profilin. Due to its extreme resistance to pepsin digestion, LTP is a potentially severe food allergen.

Allergens↗
PubMedDate not supplied

Severe systemic reactions caused by poppy seed.

We describe a case of severe systemic reactions caused from poppy seed ingestion. Poppy seeds were suspected to be responsible for the symptoms on the basis of the clinical history. This suspicion was confirmed by skin testing and the prick-prick test. Moreover, a RAST assay was conducted with an extract of fresh food, confirming the presence of specific IgE to poppy seed. Although poppy seeds are not commonly used, we highlight the possible importance of such rare and often hidden sources of allergens.

Adult↗
PubMedDate not supplied

Beer-induced anaphylaxis due to barley sensitization: two case reports.

Despite the large worldwide beer consumption, allergic reactions have very rarely been reported. We describe two cases of severe systemic reactions due to beer ingestion: one case of anaphylaxis requiring emergency care and one of generalized urticaria and angioedema. The two patients underwent a detailed diagnostic procedure involving skin testing, oral challenge with additives, detection of specific IgE to the components of beer, and oral challenge with beer in one patient. The results of the tests, in the particular skin tests and IgE assay, allowed us to detect barley as the specific ingredient responsible for the observed allergic reactions to beer. Therefore, such a sensitization should always be taken into account in the case of suspected reactions following beer ingestion.

Adult↗
PubMedDate not supplied

Anaphylaxis to pine nuts and immunological cross-reactivity with pine pollen proteins.

Despite the wide use of pine nuts, the fruit of Pinus pinea, only a few reports of allergic reactions to them have been published. We present herein a case of food allergy to pine nuts in a patient who showed no clinical symptoms to pine pollen despite the presence in her serum of specific IgE antibodies. In order to verify whether the reaction against pine nuts was IgE mediated, specific IgE against pine nuts and pollen were evaluated by skin-prick test, prick by prick and RAST. Immunoblotting and immunoblotting-inhibition were used to evaluate the allergenic components of both extracts and their cross-reactivity. Prick by prick with fresh pine nuts and RAST with pine nut and pine pollen extracts showed that the patient had high levels of specific IgE against both extracts. Immunoblotting experiments showed the presence in serum of IgE antibodies against several components in pine nuts and pollen. Immunoblotting-inhibition experiments demonstrated the presence of some cross-reacting components. These data confirm the existence of food allergy induced by pine nuts. This sensitization to pine nuts developed with no symptoms of pine pollinosis. Development of pollinosis may require a longer time of exposure to allergens. Based on the cross-reactivity between pine nut and pine pollen extracts, cosensitization to these two allergens could be possible.

Adult↗
PubMedDate not supplied

[Protein content of latex gloves used in hospitals].

In this study the total protein content and the latex allergenic protein content in different types of medical gloves commonly used in our hospital were evaluated. The correlation between these two parameters and the correctness of the data provided by the glove manufacturers have been also verified. The main purpose of this study was to acquire information useful for preventing latex allergy in our hospital personnel. 29 different types of medical gloves were examined. The total protein contents were evaluated with Lowry modified method and the allergenic latex protein contents were evaluated with RAST-inhibition assay, both on glove samples and glove extracts. The correlation between inhibition percentages found in glove samples and in glove extracts and the correlation between total protein content and inhibition percentages determined in samples of the same gloves was verified. The highest concentrations of total proteins and allergenic latex proteins were found in examination powdered latex gloves and in surgical powdered latex gloves. A good correlation was observed between the total protein content and the inhibition percentages determined in samples of the same gloves, and between inhibition percentages found in glove samples and glove extracts. A significant amount of latex proteins was found in some brands of nitryl gloves. The clear association between the total protein levels and the allergenic latex protein levels suggests that the gloves with highest total protein content have the greatest allergenic potential. We believe that the total protein content is relevant from a preventive point of view for a proper gloves selection in the workplaces. Therefore, manufacturing companies should provide package inserts including at least the total protein contents and possibly allergenic latex protein levels, with specific measurement methods. Since the highest total protein and allergenic latex protein contents were found in latex powdered gloves, powder-free gloves must be of first choice. RAST-inhibition assays directly on glove samples instead of glove extract seems to be a good reliable and faster alternative for the evaluation of the allergenic potential of latex gloves. For latex allergic subjects it is necessary to pay attention in choosing nitryl gloves, especially as an alternative to natural rubber gloves since some brands may contain significant amounts of allergenic latex proteins.

Allergens↗