[Histamine-releasing activity of acrylic plastic materials]. / Gistaminvysvobozhdaiushchaia aktivnost' akrilovykh plastmass.

The histamine-releasing activity of acrylic plastics (ftorax, stomacryl, ethacryl) used for denture making and maxillofacial prostheses was studied by automated and computer-aided fiber glass method for evaluating histamine release from whole blood basophils. The results indicate that some plastics made by the thermo-polymerization method (for example, ethacryl) are characterized by higher histamine-releasing activity than the plastics made by polymerization using superhigh frequency electromagnetic energy. The method is recommended for preliminary screening of new polymers intended for dentistry and for individual selection of materials with consideration for their safety and strength characteristics.

Introduction: risk management in asthma and allergic diseases.

The recent advances in therapy for allergic diseases, including allergic rhinitis, asthma, and urticaria, have posed new challenges to physicians who must carefully assess the risks and benefits to the patient of new treatment. Appreciation of the drug interaction between certain second-generation antihistamines, including terfenadine and astemizole, with selective macrolide antibiotics and imidazole antifungal agents leading to QTc interval prolongation, and the potential for fatal cardiac arrhythmias is an example of the need to assess risks of therapy. Risk management in allergic disease includes minimizing disease morbidity by emphasizing allergen avoidance in asthma and by minimizing the therapeutic morbidity and mortality that can occur when allergen immunotherapy is administered either improperly, such as in an unsupervised setting, or inappropriately, such as to unstable asthmatics. Physicians must carefully weigh the benefits of therapies designed to decrease costs, including regimens combining second- and first-generation antihistamines, considering both the potential risk ensued related to sedation and impaired cognitive performance when using first-generation antihistamines and the unproven efficacy of such regimens. Clearly, risk management in asthma and allergic disease will become more complex with greater understanding of mechanisms of allergic disease, of provocative factors exacerbating allergic disease, of the potential adverse consequences of therapy, and of the potential interaction among therapeutic modalities. It is essential that physicians treating the nearly 20% of Americans who have allergic disease thoroughly appreciate the risks and benefits of their therapeutic decisions.

Clinical comparison of histamine H1-receptor antagonist drugs.

Nearly 40 million Americans have symptoms of upper respiratory allergies, making antihistamines among the most frequently used pharmacologic agents. Although there are mediators of allergic symptoms in addition to histamine, therapy for allergic rhinitis and urticaria has focused upon the use of antihistamines. The classic histamine H1-receptor antagonists, however, are not selective for the H1 site and produce a variety of dopaminergic, serotonergic, and cholinergic responses leading to considerable adverse effects in the central nervous system consequent to both their pharmacologic nonselectivity and their ability to penetrate the blood-brain barrier readily. The second-generation antihistamines were a major advance in the therapy of allergic rhinitis, because they do not penetrate the blood-brain barrier as rapidly and are also designed for greater specificity at H1-receptor. Given their greater selectivity for the H1-receptor, they cause fewer undesirable central nervous system actions, whereas their efficacy is similar to that of the classic antihistamines used in the treatment of allergic rhinitis. Selecting among these antihistamines for the treatment of allergic rhinitis has focused on their pharmacokinetics and adverse effect profiles. The potential cardiotoxic effects of some antihistamines when their metabolism is inhibited requires caution in prescribing these agents. The antiallergic and antiasthmatic effects of several newer antihistamines are being explored. For the clinician, making the therapeutic decision among H1-receptor antagonists requires a comprehensive knowledge of their diverse effects.

Introduction: basophil histamine release and the diagnosis of food allergy.

The glass fiber-based automated chlorometric microtiter plate whole blood leukocyte histamine release test (LHRT) may provide an in vitro correlate to in vivo allergic responses. Depending upon the high affinity of histamine for glass fibers, the fluorometric assay for histamine has a high correlation with radioimmunoassay for native histamine. For the diagnosis of respiratory allergy, up to 90% concordance between basophil histamine release results and skin test results to common inhalant allergens has been noted, although up to 96% concordance of basophil histamine release results in bronchoprovocation tests may occur. In general, the concordance between LHRT results and either skin test results or allergen inhalation challenge results is greater than the concordance between the LHRT results and radioallergosorbent (RAST) results. The LHRT may be a valuable tool for the investigation of drug allergy and food sensitivity. The ability of the LHRT to detect both IgE-mediated and non-IgE-mediated basophil responses is a potential advantage over RAST testing in situations in which the presence of specific IgE directed toward a potential allergen has not as of yet been demonstrated. False-negative LHRT results may occur in 10 to 20% of subjects who have basophils that fail to respond to anti-IgE as a positive control. Advances in both sample and blood and constitution of sample media may minimize this percentage of nonresponding basophils. Differences between mast cell and basophil responses may occur due to functional heterogeneity between basophils and mast cell subtypes.