Epicutaneous Administration of Papain Induces IgE and IgG Responses in a Cysteine Protease Activity-Dependent Manner

ABSTRACTBackground: Epicutaneous sensitization to allergens is important in the pathogenesis of not only skin inflammation such as atopic dermatitis but also "atopic march" in allergic diseases such as asthma and food allergies. We here examined antibody production and skin barrier dysfunction in mice epicutaneously administered papain, a plant-derived occupational allergen belonging to the same family of cysteine proteases as mite major group 1 allergens.Methods: Papain and Staphylococcus aureus V8 protease were patched on the backs of hairless mice. Tran- sepidermal water loss was measured to evaluate the skin barrier dysfunction caused by the proteases. Papain or that treated with an irreversible inhibitor specific to cysteine proteases, E64, was painted onto the ear lobes of mice of an inbred strain C57BL/6. Serum total IgE levels and papain-specific IgE and IgG antibodies were measured by ELISA.Results: Papain and V8 protease patched on the backs of hairless mice caused skin barrier dysfunction and increased serum total IgE levels, and papain induced the production of papain-specific IgG1, IgG2a, and IgG2b. Papain painted onto the ear lobes of C57BL/6 mice induced papain-specific IgE, IgG1, IgG2c, and IgG2b, whereas papain treated with E64 did not. IgG1 was the most significantly induced papain-specific IgG subclass among those measured.Conclusions: We demonstrated that the epicutaneous administration of protease not only disrupted skin barrier function, but also induced IgE and IgG responses in a manner dependent on its protease activity. These results suggest that protease activity contained in environmental sources contributes to sensitization through an epicutaneous route

Effects of Nanoholes Grown by Molecular Beam Droplet Epitaxy on Electrical Properties of Two Dimensional Electron Gas

The effects of nanoholes, grown by molecular beam droplet epitaxy, on the electrical properties of quantum well (QW) heterostructures are reported. To investigate how the depth of nanoholes affect the electrical properties of the QW heterostructures, the growth conditions for nanoholes were optimized with respect to their depth and density. Using the results of the optimization of the nanohole growth, three InGaAs pseudomorphic quantum wells with nanoholes were investigated with varied depth and a constant density. A QW heterostructure without nanoholes was grown as a reference structure. For all the samples, temperature dependent Hall effect measurements, noise studies as a function of both bias and temperature, and temperature dependent current-voltage (I-V) measurements have been carried out to examine the effects of nanoholes on the QW heterostructures. The Hall effect measurements revealed clear correlation between the depth of the nanoholes and the electrical characteristics of the QW systems such as Hall mobility and sheet electron density. Besides an increase in the mobility and carrier density, the nanoholes lead to a significant reduction of 1/f noise due to a decrease in the Hooge parameter, which can be advantageous for the fabrication of high performance electronic devices. In addition, it was shown that the nanoholes change the energy spectrum of the QW heterostructures which affects carrier transport in the QWs and metal-semiconductor interface. The changes of the energy spectrum were clued in by the variation of carrier activation energy, appearance of a new deep state in the band gap of an AlGaAs barrier layer that affect carrier kinetics and fluctuation phenomena in the present material system. The results of this thesis show a potential of nanoholes grown by droplet epitaxy as a promising candidate for modulation of material properties and fabrication of advanced material systems for electronic and optoelectronic application

北太平洋遠洋域のセディメントトラップ試料における元素状炭素分析

http://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr97-02/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr98-05/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr99-k02/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr00-k01/ehttp://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr00-k03/

Molecular beam epitaxial growth of Bi2Te3 and Sb2Te3 topological insulators on GaAs (111) substrates: a potential route to fabricate topological insulator p-n junction

High quality Bi2Te3 and Sb2Te3 topological insulators films were epitaxially grown on GaAs (111) substrate using solid source molecular beam epitaxy. Their growth and behavior on both vicinal and non-vicinal GaAs (111) substrates were investigated by reflection high-energy electron diffraction, atomic force microscopy, X-ray diffraction, and high resolution transmission electron microscopy. It is found that non-vicinal GaAs (111) substrate is better than a vicinal substrate to provide high quality Bi2Te3 and Sb2Te3 films. Hall and magnetoresistance measurements indicate that p type Sb2Te3 and n type Bi2Te3 topological insulator films can be directly grown on a GaAs (111) substrate, which may pave a way to fabricate topological insulator p-n junction on the same substrate, compatible with the fabrication process of present semiconductor optoelectronic devices