Augmented B Lymphocyte Response to Antigen in the Absence of Antigen-Induced B Lymphocyte Signaling in an IgG-Transgenic Mouse Line

IgG-containing B cell antigen receptor (IgG-BCR), the BCR mostly expressed on memory B cells, contains a distinct signaling function from IgM-BCR or IgD-BCR expressed on naïve B cells. Because naïve B cells transgenic for IgG exhibit augmented response to antigens similar to memory B cells, the distinct signaling function of IgG-BCR appears to play a role in augmented antibody responses of memory B cells. However, how IgG-BCR signaling augments B cell responses is not yet well understood. Here we demonstrate that B cells from IgG-transgenic mice are anergic with defect in generation of BCR signaling upon BCR ligation. However, these IgG-transgenic B cells generate markedly augmented antibody response to a T cell-dependent antigen, probably due to hyper-responsiveness to a T cell-derived signal through CD40. Both BCR signaling defect and augmented response to CD40 ligation are partially restored in xid IgG-transgenic mice in which BCR signaling is down-modulated due to a loss-of-function mutation in the tyrosine kinase Btk crucial for BCR signaling. Thus, IgG-BCR induces augmented B cell responses in the absence of antigen-induced BCR signaling probably through high ligand-independent BCR signaling that may “idle” B cells to make them ready to respond to T cell help. This finding strongly suggests a crucial role of ligand-independent signaling in receptor function

Preparation of goat milk anti-Saccharomyces cerevisiae immunoglobulin G (IgG)-rich fraction and immunological functions of mice orally administered a mixture of the antigen and its specific IgG-rich fraction

ArticleMilk Science. 58(3):119-128 (2009)journal articl

Neutron Irradiation Effects on Magnetic Properties of Some Heusler Alloys(Metallurgy)

The neutron irradiation effects were studied with measurements of temperature dependence of magnetization in ordered and disordered Heusler alloys. The irradiation was carried out in JMTR with a total flux of fast neutrons of 10^ nvt. Fully ordered Cu_2MnIn, partially ordered Cu_2MnAl and completely disordered Cu_2MnSn were prepared with various temperature treatments. The magnetization-temperature curves of each specimen were measured before and after irradiation. In the irradiated Cu_2MnIn, the disordering by the irradiation gave rise to a decrease of magnetization, and the temperature dependence of magnetization showed that the disordered region contained various regions with different degrees of disorder. For the distribution of the disordered region, the calculation based on the theory of temperature spike by Seitz and Koekler gave a feasible result that a disordered region comprised a central core with a radius of 5.4 A which was completely disordered and a periphery of 3.3 A thickness which was partially disordered. From the magnetization-temperature curves of Cu_2MnAl, it was considered that the disordered regions induced by the irradiation had different properties from those induced by the heat treatment. The former were the localized and comprised regions corresponding to various degrees of disorder, while the latter spread spatially in a wide range with a certain degree of disorder. The ordering by enhanced diffusion occurred simultaneously to an extent comparable to the disordering, and so it played an important role in the magnetization in the partially disordered Cu_2MnAl. In the disordered Cu_2MnSn, however, the ordering effect was very small. It is supposed to be difficult for the A2 structure to transform into the L2_1 structure by the enhanced diffusion

Controlling oxygen coordination and valence of network forming cations

Understanding the structure-property relationship of glass material is still challenging due to a lack of periodicity in disordered materials. Here, we report the properties and atomic structure of vanadium phosphate glasses characterized by reverse Monte Carlo modelling based on neutron/synchrotron X-ray diffraction and EXAFS data, supplemented by Raman and NMR spectroscopy. In vanadium-rich glass, the water durability, thermal stability and hardness improve as the amount of P2O5 increases, and the network former of the glass changes from VOx polyhedra to the interplay between VOx polyhedra and PO4 tetrahedra. We find for the first time that the coordination number of oxygen atoms around a V4+ is four, which is an unusually small coordination number, and plays an important role for water durability, thermal stability and hardness. Furthermore, we show that the similarity between glass and crystal beyond the nearest neighbour distance is important for glass properties. These results demonstrate that controlling the oxygen coordination and valence of the network-forming cation is necessary for designing the properties of glass

Effect of forestation of hinoki and larch on soil chemistry in mountainous water source area for water supply to Tokyo

Effects of forestry on soil properties, stream water chemistry and mass balance in watersheds had been confieremed by many previous studies. However, they have not clarified in detail variation processes of soil chemistry and soil physics after the hinoki and larch forestation. To clarify the variation processes, it is important to confirm the difference of soil chemistry and soil physics on the artifitial and natural forest. In this research, we conducted the soil physical and chemical investigations on seven slopes covered by hinoki (chamecyparis obtusa) and larch (Larix leptolepis) artificial and beech (Fagus crenata) natural forest in a highland area, the western side of Tokyo. The water repellency of A_0 horizon was stronger on the artificial forest slope than on the natural forest. In addition, the permeability was low on the artificial forest due to the strong water repellency. On the artificial forest, both of the exchangeable base cation content and soil pH were low and Al concentration was high, as compared with those on the natural forest. These results suggest that the soil acidification is progressed on the artificial forest. The decline of soil pH by the forestation was controlled by the increase of H^+ supply at the A_0 horizon due to the property of litter decomposition and the decrease of base cation supply at the A-horizon. In general, the cation supply rate such as weathering rate is controlled by the infiltration rate and temperature. These soil physical and chemical properties suggest that infitration rate at the A-horizon. declines after the forestation, weathering rate declines and consequently soil is acidified

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In this article, we offer a simple example of analysis of variance (ANOVA) and multiple classification analysis (MCA ) using SPSS/PC + . Furthermore, we examine the relationship between MCA and Hayasi\u27s first method of quantification. It is indicated that, although both analyses use different algorithms for solution, that is, iterative technique for MCA and dummy variables for the Hayasi\u27s first method of quantification, each analysis finally yields same results. Mathematical implications of both analysis models are discussed

Generation of Embryonic Stem Cell Lines from Immature Rabbit Ovarian Follicles

In mammalian ovaries, many immature follicles remain after the dominant follicles undergo ovulation. Here we report the successful production of rabbit embryonic stem cells (ESCs) from oocytes produced by in vitro culture of immature follicles and subsequent in vitro maturation treatment. In total, we obtained 53 blastocysts from oocytes that received intracytoplasmic sperm injection followed by in vitro culture. Although only weak expression of POU5f1 was observed in the inner cell masses of in-vitro-cultured follicle-derived embryos, repeated careful cloning enabled establishment of 3 stable ESC lines. These ESC lines displayed the morphological characteristics of primed pluripotent stem cells. The ESC lines also expressed the pluripotent markers Nanog, POU5f1, and Sox2. Further, these ESCs could be differentiated into each of the 3 different germ layers both in vitro and in vivo. These results demonstrate that immature follicles from rabbits can be used to generate ESCs. Moreover, the use of rabbit oocytes as a cell source provides an experimental system that closely matches human reproductive and stem cell physiology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140197/1/scd.2012.0300.pd