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Allergenic Properties (allergenic + property)
Selected AbstractsStrong irritants masquerading as skin allergens: the case of benzalkonium chlorideCONTACT DERMATITIS, Issue 4 2004David A. Basketter Chemicals may possess a number of hazards to human health including the ability to cause skin irritation and contact allergy. Identification and characterization of these properties should fall within predictive toxicology, but information derived from human exposure, including clinical experience, is also of importance. In this context, it is of interest to review the case of benzalkonium chloride, a cationic surfactant. This chemical is a well-known skin irritant, but on occasions it has also been reported to have allergenic properties, typically on the basis of positive diagnostic patch test data. Because the accumulated knowledge concerning the properties of a chemical is employed as the basis for its regulatory classification (e.g. in Europe), as well as for informing the clinical community with respect to the diagnosis of irritant versus allergic contact dermatitis (ACD), it is important to distinguish properly which chemicals are simply irritants from those which are both irritant and allergenic on skin. A review of the information on benzalkonium chloride confirms that it is a significant skin irritant. However, both predictive test results and clinical data lead to the conclusion that benzalkonium chloride is, at most, an extremely rare allergen, except perhaps in the eye, but with many supposed cases of ACD being likely to arise from the misinterpretation of patch test data. As a consequence, this substance should not normally be regarded as, or classified as, a significant skin sensitizer. [source] Airborne contact dermatitis from methylchloroisothiazolinone in wall paint.CONTACT DERMATITIS, Issue 4 2000Abolition of symptoms by chemical allergen inactivation Preservatives such as isothiazolinones in paints have been reported to cause airborne contact dermatitis. The patients whom we report experienced acute dermatitis on air-exposed skin and respiratory symptoms after staying in recently painted rooms. Kathon® (methylchloroisothiazolinone/ methylisothiazolinone) added as preservative to the wall paint was identified as causative agent. In one individual symptoms rapidly disappeared after treatment of the painted walls with inorganic sulfur salt, which leads to inactivation of the allergenic properties of methylchloroisothiazolinone/ methylisothiazolinone. We describe the patients, the clinical course and review the literature pertinent to such cases. In addition we report on the chemical analyses of the decorating paints used, and on experiments on emission and air concentration of methylchloroisothiazolinone/methylisothiazolinone from a painted surface before and after inactivation by sodium bisulfite. [source] State of the art and new horizons in the diagnosis and management of egg allergyALLERGY, Issue 3 2010A. H. Benhamou To cite this article: Benhamou AH, Caubet J-C, Eigenmann PA, Nowak-We,grzyn A, Marcos CP, Reche M, Urisu A. State of the art and new horizons in the diagnosis and management of egg allergy. Allergy 2010; 65: 283,289. Abstract Egg allergy is one of the most frequent food allergies in children below the age of three. Common symptoms of egg allergy involve frequently the skin as well as the gut and in more severe cases result in anaphylaxis. Non-IgE-mediated symptoms such as in eosinophilic diseases of the gut or egg-induced enterocolitis might also be observed. Sensitization to egg white proteins can be found in young children in absence of clinical symptoms. The diagnosis of egg allergy is based on the history, IgE tests as well as standardized food challenges. Ovomucoid is the major allergen of egg, and recent advances in technology have improved the diagnosis and follow-up of patients with egg allergy by using single allergens or allergens with modified allergenic properties. Today, the management of egg allergy is strict avoidance. However, oral tolerance induction protocols, in particular with egg proteins with reduced allergenic properties, are promising tools for inducing an increased level of tolerance in specific patients. [source] Instability of the structure and allergenic protein content in Arizona cypress pollenALLERGY, Issue 12 2009Y. Shahali Background:, The allergenic characteristics of pollen and their levels of expression may vary depending on the plant species, the degree of maturation and the influence of environmental factors such as climate and atmospheric pollution. The objective of this survey was the comparison of the structure and allergenic protein content in Arizona cypress (Cupressus arizonica, CA) pollen collected just after microsporangia dehiscence and 2 weeks later in urban areas. Methods:, The morphology and structure of pollen were examined by scanning electron microscopy. Pollen protein content was quantitatively and qualitatively investigated by Bradford protein assay, SDS-PAGE and densitometric analysis respectively. Fifteen allergic subjects, according to their clinical history of seasonal rhino-conjunctivitis and bronchial asthma have been selected for skin prick testing and ImmunoCap using CA standard allergen and for immunoblotting using extracts of CA mature pollen collected from Tehran. Results:, After 2 weeks, numerous cracks and collapses appeared in pollen surfaces. Western blotting performed by using extracts of pollen collected from Tehran, revealed that sera-specific immunoglobulin E of all allergic subjects reacted to a 35 kDa protein. The presence of this new major allergen and the decrease of Cup a 1 provide reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the CA pollen allergy in Tehran. Conclusion:, The instability of the pollen structure and protein content affects CA pollen allergenic properties. This study also suggests that to optimize CA standard allergen preparations, the eventual variability of pollen allergenic components have to be considered for each region. [source] Allergy assessment of foods or ingredients derived from biotechnology, gene-modified organisms, or novel foodsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 6 2004Lars K. Poulsen Abstract The introduction of novel proteins into foods carries a risk of eliciting allergic reactions in individuals sensitive to the introduced protein and a risk of sensitizing susceptible individuals. No single predictive test exists to perform a hazard assessment in relation to allergenic properties of newly expressed proteins in gene-modified organisms (GMOs). Instead, performance of a weighted risk analysis based on the decision tree approach has been suggested. The individual steps of this analysis comprise sequence homology to known allergens, specific or targeted serum screens for immunoglobulin E (IgE) cross-reactions to known allergens, digestability studies of the proteins in simulated gastric and/or intestinal fluids, and animal studies. These steps are discussed and five examples of risk evaluation of GMOs or novel foods are presented. These include ice-structuring protein derived from fish, microbial transglutaminase, GMO-soybeans, amylase and the Nangai nut. [source] Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potentialCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2006T. Eiwegger Summary Background The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. Methods An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. Results In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments Mr L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-,/IL-13 ratio and IFN-,/IL-4 ratio of CFSElow CD4+ T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. Conclusion Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein. [source] Plant non-specific lipid transfer proteins as food and pollen allergensCLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2004G. Salcedo Summary Several members of the plant non-specific lipid transfer protein (LTP) family have been identified as relevant allergens in foods and pollens. These allergens are highly resistant to both heat treatment and proteolytic digestion. These characteristics have been related with the induction of severe systemic reactions in many patients, and with the possibility of being primary sensitizers by the oral route. A specific geographical distribution pattern of sensitization to LTP allergens has been uncovered. This allergen family is particularly important in the Mediterranean area, but shows a very limited incidence in Central and Northern Europe. The potential role in the plant, as well as the biochemical and allergenic properties of the LTP family, are reviewed here. [source] | ||||||||||