RESUMEN
Treatment of CHO cells with AluI in the S-phase leads to chromatid-type aberrations whose frequencies are linearly correlated with dose. Treatment in the S-phase leads to fewer aberrations than treatment in the G1-phase, which is comparable to chromosomal aberration induction following X-irradiation in the G1- and S-phases. Treatment in the G1-phase leads to few chromatid-type interchanges, some of these may originate from DNA single-strand gaps induced by AluI in canonical structures of DNA and in DNA.RNA hybrids.
Asunto(s)
Cromátides , Aberraciones Cromosómicas , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Intercambio de Cromátides Hermanas , Animales , Células CHO , Cromátides/efectos de los fármacos , Cricetinae , ADN/genética , ADN/metabolismo , Daño del ADN , Desoxirribonucleasas de Localización Especificada Tipo II/toxicidad , Fase G1 , Metafase , Fase SRESUMEN
Histamine as an important mediator of the allergic reaction has been measured by a number of methods both in whole blood and cell supernatants after in vitro release. We compared the fluorometric histamine assay with two radioimmunoassays and studied detection limit, recovery, cross-reactivity and accuracy in buffer-based standards as well as the sensitivity after IgE-mediated in vitro release from washed cells and whole blood. Our data indicate that the double-antibody RIA (Pharmacia) can be used for studies of basophil histamine release in both whole blood and cell supernatants. Due to significant cross-reactivity to N-methyl-histamine it cannot be used for histamine determinations in plasma. The second radioimmunoassay using succinyl-glycine as an acylating reagent and monoclonal antibodies, which have been raised to acylated histamine, is the most sensitive assay without any cross-reactivity with methylhistamine.
Asunto(s)
Histamina/sangre , Radioinmunoensayo/métodos , Anticuerpos Monoclonales , Células Cultivadas , Reacciones Cruzadas , Fluorometría , Humanos , Hipersensibilidad Inmediata/inmunología , Sensibilidad y EspecificidadRESUMEN
Allergenic proteins of the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farinae and their major allergens Der p I and Der f I are one of the most significant environmental factors which may facilitate sensitization and allergic airway disease in childhood. In order to measure seasonal variations of mite allergen exposure, we collected mattress dust samples monthly in 13 homes over a period of 1 year. Der p I and Der f I were determined with a sandwich type ELISA. Mite allergen levels were significantly lower from January-June than from July-December (p less than 0.05) which was mostly due to Der p I variations. Only in 6 of the studied homes seasonal variations in mite allergen concentrations according to seasonal variations in outdoor humidity could be observed. In 7 homes mite allergen exposure stayed constant and seemed to depend only on indoor climate factors.
Asunto(s)
Alérgenos/análisis , Polvo/análisis , Ácaros , Hipersensibilidad Respiratoria/etiología , Rinitis Alérgica Perenne/etiología , Estaciones del Año , Alérgenos/efectos adversos , Animales , Antígenos Dermatofagoides , Niño , Estudios Transversales , Polvo/efectos adversos , Alemania Occidental/epidemiología , Humanos , Incidencia , Ácaros/análisis , Hipersensibilidad Respiratoria/epidemiología , Rinitis Alérgica Perenne/epidemiologíaRESUMEN
Concentrations of major allergens of Dermatophagoides pteronyssinus (Dpt) and D. farinae (Df), Der p I and Der f I, were determined in 183 dust samples of mattresses of 133 atopic and 50 nonatopic children by a sandwich-type ELISA. Atopic children and young adults living in houses with high levels of Der p I and Der f I (greater than or equal to 2000 ng/gm of dust) were found to have significantly higher serum IgE levels to Dpt and Df (p less than 0.0001) compared to patients with low mite-allergen exposure. Washed leukocytes of 55 atopic children and 14 control subjects were investigated for in vitro histamine release to serial dilutions of Der p I; 86% of highly exposed (greater than or equal to 10,000 ng/gm) children demonstrated positive histamine release in response to Der p I compared to 17% in the group with very low exposure (less than 400 ng/gm). There was a positive correlation between basophil sensitivity (rs = 0.6; p less than 0.0001) and reactivity (rs = 0.54; p less than 0.0001) to Der p I and mite-allergen exposure. The relative risk for sensitization in the highly exposed group versus the group with very low exposure was sevenfold to 32-fold increased. We conclude that high concentrations of mite allergen (greater than or equal to 2000 ng/gm) increase the risk of specific sensitization in atopic children and young adults and thus may facilitate allergic airway disease.