No abstract

Background: Anaphylaxis is classically mediated by allergen cross-linking of IgE bound to the a chain of FcεRI, the mast cell/basophil high affinity IgE receptor. Allergen cross-linking of the IgE/FcεRI complex activates these cells, inducing release of disease-causing mediators, cytokines, and enzymes. We previously demonstrated that IgE-mediated anaphylaxis could be safely prevented in wild-type BALB/c mice by rapid desensitization with anti-mouse FcεRIa mAb. Objective: This study sought to use humanized mice to extend these results to humans. Methods: We actively immunized huFcεRIa/F709 mice, which express human (hu) instead of mouse FcεRIa and a mutant IL-4 receptor that lacks inhibitory function. We passively immunized huFcεRIa mice, as well as human cord blood-reconstituted reNSGS mice, which are immune-deficient, produce mast cellstimulating human cytokines, and develop numerous human mast cells. For desensitization, we used anti-huFcεRIa mAbs that bind FcεRIa regardless of its association with IgE (noncompeting mAbs), and/or mAbs that compete with IgE for huFcεRIa binding (competing mAbs). Anaphylaxis was induced by intravenous injection of antigen or anti-huIgE mAb. Results: Anti-huFcεRIa mAb rapid desensitization was safer and more effective than allergen rapid desensitization and suppressed anaphylaxis more rapidly than omalizumab or ligelizumab. Rapid desensitization of na€ ıve, IgE-sensitized huFcεRIa mice and huFcεRIa/F709 mice that were egg-allergic with anti-FcεRIa mAbs safely removed >98% of IgE from peritoneal mast cells and completely suppressed IgE-mediated anaphylaxis. Rapid desensitization of reNSGS mice with anti-FcεRIa mAbs also safely removed 98% of mast cell IgE and prevented IgE-mediated anaphylaxis. Conclusions: Rapid desensitization with anti-FcεRIa mAbs may be a safe, effective, and practical way to prevent IgE-mediated anaphylaxis.

No abstract

Focused ion beam ͑FIB͒ methodologies for successfully milling copper ͑U.S. Patent No. 6,322,672 B1͒ have been demonstrated. Approaches to milling copper ͑Cu͒ are required because standard FIB mill procedures produce rough, uneven cuts that are unsuitable for circuit edits, a principal FIB function. Efforts to develop gas assisted etching ͑GAE͒ processes which would smoothly mill Cu failed because Cu halides are not volatile and remain on the substrate as corrosive electrically conductive debris. Single crystal studies show that Cu grains with different crystal orientations vary in mill rate by as much as 4ϫ. Moreover, the ͑110͒ crystal orientation, which mills most slowly, forms a Cu 3 Ga phase when milled with a focused Ga ion beam. This phase is particularly resistant to milling and, in polycrystalline Cu, propagates during the milling operation, contributing to the uneven trench profiles. CoppeRx, a novel scan strategy, cleanly and uniformly removes polycrystalline Cu with minimal damage to the underlying dielectric. CoppeRx minimizes the formation and propagation of the Cu 3 Ga phase and equalizes the etch rates of the Cu crystal orientations. The CoppeRx strategy includes the milling of an ''egg crate'' topography to minimize the propagation of the Cu 3 Ga phase and the creation of a heavy atom sacrificial layer of the Cu surface ͑U.S. Patent Application No. 20010053605͒ which scatters the incident Ga ion beam, thereby reducing the channeling influence on Cu milling rates. This heavy atom layer is created by flowing W͑CO͒ 6 vapor during the FIB milling process. The CoppeRx scan strategy is especially beneficial for milling thick ͑Ͼ0.8 m͒ Cu structures with large, prominent grains. Because Cu interconnect lines are relatively thin ͑Ͻ0.4 -0.5 m͒, grain-related milling roughness is less of a problem. The CoppeRx egg crate topography and W scattering layer are not required. Instead, the successful cutting of 40 ohm Cu interconnect lines to produce Ͼ20 M ohm open circuits is achieved by flowing O 2 or H 2 O during the milling process ͑U.S. Patent No. 6,322,672B1͒. The O 2 /H 2 O flow smoothes the Cu milling by producing an amorphous surface oxide, thereby reducing channeling, and by enhancing the etch selectivity for Cu relative to the surrounding and underlying SiO 2 based dielectric. These interconnect cuts have been routinely done at the bottom of high aspect ratio holes ͑e.g., 1ϫ1ϫ9 m͒.

A spectrum of in vivo-expressed Staphylococcus epidermidis antigens was identified by probing a bacteriophage lambda library of S. epidermidis genomic DNA with human serum from infected and uninfected individuals. This analysis resulted in identification of 53 antigen-encoding loci. Six antigenic polypeptides were expressed from these loci and purified. These polypeptides were the propeptide, mature amidase, and repeat sequence domains of the major autolysin AtlE, GehD (lipase), and two members of a conserved family of surface proteins (ScaA [AaE] and ScaB). AtlE, ScaA, and ScaB all exhibit human ligand binding capacity. Screening a bank of human serum samples revealed that there were significant increases in the amounts of reactive immunoglobulin G in infected individuals compared to the amounts in healthy individuals for the repeat sequence and mature amidase domains of AtlE, ScaB, and GehD. Vaccination of mice with recombinant antigens stimulated an immune response which in vitro opsonized S. epidermidis. In this study we identified prospective candidate antigens for prophylaxis or immunotherapy to control disease.