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Skin Tests and Specific IgE Determinations in the Diagnosis of Contact Urticaria and Respiratory Disease Caused by Low-Molecular-Weight Chemicals
Published in Ana M. Giménez-Arnau, Howard I. Maibach, Contact Urticaria Syndrome, 2014
Kristiina Aalto-Korte, Outi Kuuliala, Eva Helaskoski
Contrary to recommendations, at FIOH, prick tests have always been used with rather wide indications as a “screening” method for immediate-type allergy/hypersensitivity. Determination of specific IgE is a practical alternative in primary health care and for patients with severe symptoms. Because FIOH’s patients come from all parts of the country, we do not usually have time to wait for the results of specific IgE determination before prick tests. Moreover, the determination of specific IgE is not very useful in terms of LMW chemicals, because commercial assays are available for only a few chemicals. As far as we know, the recommendation of starting with an open application test in the diagnosis of contact urticaria has never been widely followed in Finland: if we are concerned about systemic reactions, we begin prick tests at very low concentrations. Of course, it is important to reduce the number of tested substances in patients with severe symptoms, concentrate on the most probable candidates for causative agents, and proceed stepwise. The amount of the allergen used in an open test is much larger than the minute amount used in a prick test. Because many patients have concomitant respiratory hypersensitivity to the same allergen, there is a real risk of inducing respiratory or even systemic symptoms from inhalation of the allergen that is applied to the forearm skin, not far from the patient’s respiratory zone. Moreover, a prick test usually produces only one wheal, whereas in a strongly positive open application test, a large wheal area appears. We are more afraid of provoking systemic symptoms in an open application test than in a prick test. The amount of the allergen can be further lowered using the prick-prick method as suggested by Hoekstra et al. in the Netherlands.[1] Of course, the rarity of anaphylactic symptoms among our occupational patients has formed our diagnostic policies. The prick test is used as the first diagnostic method in many other countries also.[2–5]
Characterization of Epidermal Langerhans Cells
Published in Francis N. Marzulli, Howard I. Maibach, Dermatotoxicology Methods: The Laboratory Worker’s Vade Mecum, 2019
Marie Cumberbatch, Rebecca J. Dearman, Ian Kimber
As described above, the migration of LC from the skin, or culture of LC with appropriate cytokines, results in a number of phenotypic modifications associated with changes in location and/or function. It has been demonstrated that topical exposure of mice to chemical allergens provokes the altered expression of some membrane determinants in situ. Particular attention has been paid to MHC class II expression on LC. Aiba and Katz (1990) found that several contact allergens when applied topically to mice caused a marked increase in the expression of MHC class II by LC local to the site of exposure. In similar experiments, treatment of mice with vehicle alone or with skin irritants failed to induce such changes (Aiba and Katz, 1990). On the basis of these data, it was proposed that altered expression by LC of MHC class II might provide a means of identifying contact allergens and of distinguishing between allergens and irritants. In a separate series of experiments, it was found that another skin sensitizing chemical, 2,4-dinitrochlorobenzene, also caused an increase of MHC class II expression by murine LC within 18 hrof exposure. However, in parallel investigations, trimellitic anhydride, a chemical associated primarily with occupational respiratory hypersensitivity in humans, failed to induce increased MHC class II at application concentrations that resulted in contact sensitization (Cumberbatch et al., 1992a). The significance of induced alterations in MHC class II antigen density on LC and the potential utility of such measurements for distinguishing between chemical allergens and skin irritants and between different classes of chemical allergens remains uncertain. Nevertheless, evaluation in situ, or using cells isolated from epidermal sheets, of changes in LC phenotype provoked by topical exposure to chemicals may provide information of value in characterizing forms of cutaneous toxicity. In this context, it is of interest that in a recent series of experiments it was observed in mice that a contact allergen, picryl chloride, induced in a proportion of local LC an increase in MHC class II antigen expression and a simultaneous decrease in E-cadherin. Identical treatment of mice with several contact irritants failed to result in similar changes (Schwarzenberger and Udey, 1996).
Seating and Mobility for The Severely Disabled
Published in Raymond V. Smith, John H. Leslie, Rehabilitation Engineering, 2018
Foaming — Polyurethane foams are usually manufactured from two chemically reacting components (A & B), one an isocyanate and the other a resin, both liquid at room temperature. Once mixed in the correct proportions, a chemical reaction generates an innocuous blowing agent (C02) that causes the foam to rise, form cells, and therby increase its volume 15 to 20 times. This polymerization and expansion process can be used to obtain custom-contoured shapes of body supports. If the foaming process uses the person directly as the mold, it is termed a foam-in-place or direct foaming process. If the foaming is done against a plaster positive or mold of the body, it is termed a foam-in-box or indirect process. Polyurethane foams may be formulated to be either flexible or rigid upon polymerization. Flexible foams are used in furniture cushions as well as in many traditional wheelchair cushions. Rigid foams have been most commonly used for spray-on industrial insulations. The unpolymerized isocyanate component can be harmful if exposed to skin, eyes, or mucous membranes, especially for those with respiratory hypersensitivity. Therefore, it is very important that the isocyanate component be of the MDI and not the TDI variety, since the MDI type is much less hazardous. Rather extensive toxicity studies have been done to evaluate the level of risk to clients during the foam-in-place process.7 This study, plus no reported problems after over 500 clinical applications, suggests that the risk to health of both clients and staff is minimal. However, the handling precautions of the industry must be observed. The one commercial foam-in-place or direct system (Pin Dot, Quick Foam) uses flexible foam to rapidly produce a two-piece seating system. The seating system is produced directly against the person’s body while being supported in his/her wheelchair.8 Applications with the cerebral palsy group have been mainly those with severe discomfort problems due to deformity. The main applications have been for those with spinal cord injury and Duchenne muscular dystrophy who are seeking comfort through resilient support. Although the two-piece foam-in-place system can be used to quickly produce (3 to 4 h) custom-contoured resilient seat and back modules, successful polymerization of flexible foams does require precise mixing and handling techniques. Also, the desired body posture must be correct or the process will have to be repeated. The indirect foaming process will be discussed further under the discussion on central fabrication.
Physiological responses to cisplatin using a mouse hypersensitivity model
Published in Inhalation Toxicology, 2020
David M. Lehmann, Wanda C. Williams
Recently, we developed the first mouse model of platinum respiratory hypersensitivity. Using this model, we showed that mice dermally sensitized with ammonium hexachloroplatinate (AHCP) or ammonium tetrachloroplatinate (ATCP) (1) exhibit an immediate pulmonary response (2) are responsive to methacholine, (3) experience inflammatory cell infiltration of the lung following respiratory tract challenge with platinum compound, and (4) have significantly elevated total serum IgE; Williams et al. 2015; Lehmann and Williams 2018). This model was also used to perform proof-of-concept studies demonstrating cross-reactivity between AHCP and ATCP (Lehmann and Williams 2018). Here, we use this model to investigate the development and manifestation of hypersensitivity reactions to CDDP.
Framework for sensitization assessment of extractables and leachables in pharmaceuticals
Published in Critical Reviews in Toxicology, 2022
Patricia Parris, Geraldine Whelan, Anders Burild, Jessica Whritenour, Uma Bruen, Joel Bercu, Courtney Callis, Jessica Graham, Esther Johann, Troy Griffin, Martin Kohan, Elizabeth A. Martin, Melisa Masuda-Herrera, Brad Stanard, Eric Tien, Maureen Cruz, Lee Nagao
In contrast to classification of skin sensitizers, classification of respiratory sensitizers according to GHS/CLP is not clear. For example, any chemical that induces a specific respiratory hypersensitivity reaction at a low to moderate (category 1B) or high (category 1 A) frequency of occurrence in humans should be considered a respiratory sensitizer. However, low to moderate and high frequencies are not defined. Also, consideration should be given to the size of the exposed population, as well as the extent and conditions of exposure, but this is not explained or further clarified (Arts 2020). Therefore, the classification is subjective and will likely be based on the experience of the toxicologist.
Time-course transcriptomic alterations reflect the pathophysiology of polyhexamethylene guanidine phosphate-induced lung injury in rats
Published in Inhalation Toxicology, 2019
Mi-Kyung Song, Dong Im Kim, Kyuhong Lee
CTD analysis revealed that several short-term exposure-specific genes (ARG2, CCL2, and CXCL1) were involved in respiratory hypersensitivity (i.e., exaggerated sensory and reflexogenic responses to inhaled irritants), which is a common pathophysiological feature in patients with respiratory inflammatory diseases. These genes might play an important role in chemokine-mediated defense and inflammation signaling and could potentially alter PHMG-P-induced respiratory hypersensitivity and inflammatory lung injury.