Utility of the Basophil Activation Test Using Gly m 4, Gly m 5 and Gly m 6 Molecular Allergens for Characterizing Anaphylactic Reactions to Soy

There are two major clinically described forms of IgE-dependent soy allergy: (i) a primary dietary form, linked to sensitization against soy storage proteins Gly m 5 and Glym 6, and (ii) a form included in birch-soy syndromes linked to Gly m 4, a PR-10-like allergen. This second form sometimes causes severe systemic reactions, even anaphylaxis, especially on consuming certain forms of soy such as soymilks or smoothies. Skin prick tests and specific IgE assays against soy whole extracts lack sensitivity. Assays of anti-Gly m 4, Gly m 5 and Gly m 6 specific IgEs have been developed to overcome this obstacle, but they unfortunately lack specificity, especially for anti-Gly m 4. We hypothesized that the basophil activation test (BAT) using molecular soy allergens Gly m 4, Gly m 5 and Gly m 6 would both remedy the lack of sensitivity of other tests and offer, through its mechanistic contribution, greater specificity than the assay of anti-Gly m 4 specific IgEs. This would enable the two types of soy allergy to be separately identified. In a characteristic clinical example of PR-10-induced anaphylactic reaction after consuming soymilk, we report preliminary results of Gly m 4-exclusive positivity of BAT supporting our hypothesis. It will be necessary to confirm these results on more patients in subsequent studies, and to specify the place of the BAT in an overall diagnostic strategy. Meanwhile, soy BAT using molecular allergens is a promising diagnostic tool for soy allergy and probably also for follow-up in specific immunotherapies.

Resonance scattering by fish schools: A comparison of two models

The effective medium method is used to investigate resonance scattering from schools of fish with gas-filled swim bladders, as a function of frequency and azimuth. Calculations are also performed with a coupled differential equation model, which incorporates both multiple scattering between fish and wave interference interactions of their scattered fields [Feuillade, Nero, and Love, J. Acoust. Soc. Am. 99, 196-208 (1996)]. A theoretical comparison of the models for idealized spherical schools shows good agreement over the entire resonance region in the forward direction, where interference interactions have a minimal effect. Good agreement is also seen in back scattering at low frequencies, where the wavelength λ≥4s, and s is the average nearest neighbor fish separation. If λ<4s, the models diverge in back scattering, and the effective medium method fails. This can be critically important when migrations of schools to deeper water cause the collective resonance frequency to increase. Multiple scattering interactions are negligible when |4πnf(b)(2)/k|⪅0.01, where n is the fish number density, f(b) is the individual fish scattering amplitude, and k=2π/λ. A comparison with forward scattering data shows very good agreement for both models, and indicates a method for estimating fish abundance. For back scattering data, the effective medium method diverges strongly when λ<4s.

Sound extinction by fish schools: forward scattering theory and data analysis

A model used previously to study collective back scattering from fish schools [Feuillade et al., J. Acoust. Soc. Am. 99(1), 196-208 (1996)], is used to analyze the forward scattering properties of these objects. There is an essential physical difference between back and forward scattering from fish schools. Strong frequency dependent interference effects, which affect the back scattered field amplitude, are absent in the forward scattering case. This is critically important for data analysis. There is interest in using back scattering and transmission data from fish schools to study their size, the species and abundance of fish, and fish behavior. Transmission data can be processed to determine the extinction of the field by a school. The extinction of sound depends on the forward scattering characteristics of the school, and data inversion to provide information about the fish should be based upon a forward scattering paradigm. Results are presented of an analysis of transmission data obtained in September 1995 during an experiment performed in the Gulf of Lion in the Mediterranean Sea [Diachok, J. Acoust. Soc. Am. 105(4), 2107-2128 (1999)]. The analysis shows that using forward scattering leads to significantly larger estimates of fish abundance than previous analysis based upon back scattering approaches.

Modulation of iron regulatory protein functions. Further insights into the role of nitrogen- and oxygen-derived reactive species

Iron regulatory protein (IRP) is a cytosolic bifunctional [Fe-S] protein which exhibits aconitase activity or binds iron responsive elements (IREs) in untranslated regions of specific mRNA. The modulators of these activities are the intracellular concentration of iron and, as recently described, NO synthase activity. In this study, we attempted to establish in in vitro experiments whether peroxynitrite (ONOO-, the product of the reaction between NO and O2-.), as well as oxygen-derived radicals (O2-. and H2O2) and various NO donors, allow IRP to bind IREs using cytosol extract of macrophagelike RAW 264.7 cells. Neither the addition of a bolus of ONOO- or H2O2 nor O2-. generation significantly affected IRE binding even though they inhibited its aconitase activity. Moreover, we show that 3-morpholinosydnonimine (SIN-1), a chemical which releases both NO and O2-. enhanced IRE binding activity of IRP only in the presence of superoxide dismutase (SOD). S-Nitrosothiols and the NONOate sper/NO plus gluthathione (GSH) activated IRE binding by IRP whereas oxyhemoglobin prevented enhancement of this binding by SIN-1/SOD and sper/NO plus GSH. cis-Aconitate, substrate, also abolished the effect of SIN-1/SOD on IRE binding by IRP. These results imply that neither O2-. nor ONOO- can convert [4Fe-4S] IRP into IRE-binding protein but rather suggest that an active redox form of NO converts IRP into its IRE binding form by targeting the [Fe-S] cluster.