Alymphoplasia is caused by a point mutation in the mouse gene encoding Nf-kappa b-inducing kinase.

The alymphoplasia (aly) mutation of mouse is autosomal recessive and characterized by the systemic absence of lymph nodes (LN) and Peyer's patches (PP) and disorganized splenic and thymic structures with immunodeficiency. Although recent reports have shown that the interaction between lymphotoxin (LT) and the LT beta-receptor (Ltbeta r, encoded by Ltbr) provides a critical signal for LN genesis in mice, the aly locus on chromosome 11 is distinct from those for LT and its receptor. We found that the aly allele carries a point mutation causing an amino acid substitution in the carboxy-terminal interaction domain of Nf-kappa b-inducing kinase (Nik, encoded by the gene Nik). Transgenic complementation with wild-type Nik restored the normal structures of LN, PP, spleen and thymus, and the normal immune response in aly/aly mice. In addition, the aly mutation in a kinase domain-truncated Nik abolished its dominant-negative effect on Nf-kappa b activation induced by an excess of Ltbeta r. Our observations agree with previous reports that Ltbeta r-deficient mice showed defects in LN genesis and that Nik is a common mediator of Nf-kappa b activation by the tumour necrosis factor (TNF) receptor family. Nik is able to interact with members of the TRAF family (Traf1, 2, 3, 5 and 6), suggesting it acts downstream of TRAF-associating receptor signalling pathways, including Tnfr, Cd40, Cd30 and Ltbeta r. The phenotypes of aly/aly mice are more severe than those of Ltbr-/- mice, however, indicating involvement of Nik in signal transduction mediated by other receptors.     

氙原子沿着UO2核燃料位错线的运动行为

推导出了一个相干扩散方程用来研究核燃料边缘位置处氙原子沿着位错线的运动规律,并给出了促使其扩散的微观物理机制,研究了氙气泡在材料中的生长受限行为.利用这种含时的有限扩散技术,可以数值计算张力相干扩散过程,进而给出氙原子沿着位错线的扩散性质.结果表明:氙原子沿着位错线的运动是随着驱动能线性变化的,同时,给出了燃料中边缘位置氙气泡无法长大的物理原因.

Abstract：

We give a coherent diffuse equation to study the behaviors of Xenon atom along the dislocation and the Xenon bubble movement mechanism in the UO2 nuclear Fuel boundary, at the same time, we study the Xenon bubble growth behavior. By using a time-dependent finite-difference technique, we can numerically solve stress coherence diffuse equation and study the transfer properties of Xenon along the dislocation. Our numerical results show that the transport of the xenon atom along dislocation is linear change with the external driven energy, and we give the reason of the growth limit of xenon bubble.     

Asymmetric Synthesis Using Enzymes in Supercritical CO2

Great efforts have been extended to catalysis in supercritical CO2（scCO2） since the early 1990＇s due to the environmental friendliness, high diffusivity, high solubilizing power, easiness of the product separation, etc.. A combined process of scCO2 and enzymatic catalyst system would be a promising synthetic tool to produce optically active compounds because the enzyme has advantages of being natural and having high enantioselectivity in nature. Here we report asymmetric synthesis using lipase and alcohol dehydrogenase in scCO2.     

Clonal nature of mast-cell clusters formed in W/Wv mice after bone marrow transplantation.

We have recently found that the number of mast cells in the skin of adult W/Wv mice is less than 1% of that observed in congeneic +/+ mice, and that no mast cells are detected in other tissues of W/Wv mice. After the transplantation of bone marrow cells from congeneic +/+ mice, the number of mast cells in the skin, stomach, caecum and mesentery of the W/Wv mice increased to levels similar to those of the +/+ mice. Study of the mast-cell number in the W/Wv mice at various times after transplantation suggested to use that mast cells might develop in groups, particularly in the skin and mesentery. In this report, we have attempted to elucidate the possible clonal origin of such mast-cell clusters from a single precursor cell, using giant granules of beige (C57BL/6-bgJ/bgJ, Chediak-Higashi syndrome) mice as a marker to identify the origin of the mast cells (Fig. 1). We found that when WB-W/+xC57BL/6-Wv (WBB6F1)-W/Wv mice were injected with a mixture of bone marrow cells from beige C57BL/6 mice and normal C57BL/6 mice, more than 95% of mast-cell clusters consisted of either beige-type cells alone or normal-type cells alone. We conclude, therefore, that the cluster of mast cells originated from a single precursor cell.     

Possible regulation of membrane-associated cyclic AMP phosphodiesterase in rat cerebral cortex by lipids

Summary Cyclic AMP phosphodiesterase (PDE) in membrane fraction from rat cerebral cortex was activated by Triton X-100, and treatment at alkaline pH and with phospholipase C. These results suggest that membrane PDE exists in a latent form and is influenced by microenvironmental changes within the membrane. Furthermore, the PDE, unlike soluble enzyme, is not influenced by a protein activator and Ca⁺⁺.     

DMY is a Y-specific DM-domain gene required for male development in the medaka fish

Although the sex-determining gene Sry has been identified in mammals, no comparable genes have been found in non-mammalian vertebrates. Here, we used recombinant breakpoint analysis to restrict the sex-determining region in medaka fish (Oryzias latipes) to a 530-kilobase (kb) stretch of the Y chromosome. Deletion analysis of the Y chromosome of a congenic XY female further shortened the region to 250 kb. Shotgun sequencing of this region predicted 27 genes. Three of these genes were expressed during sexual differentiation. However, only the DM-related PG17 was Y specific; we thus named it DMY. Two naturally occurring mutations establish DMY's critical role in male development. The first heritable mutant--a single insertion in exon 3 and the subsequent truncation of DMY--resulted in all XY female offspring. Similarly, the second XY mutant female showed reduced DMY expression with a high proportion of XY female offspring. During normal development, DMY is expressed only in somatic cells of XY gonads. These findings strongly suggest that the sex-specific DMY is required for testicular development and is a prime candidate for the medaka sex-determining gene.     

Spleen colony-forming cell as common precursor for tissue mast cells and granulocytes

The haematopoietic stem cells which produce colonies in the spleen of irradiated mice (CFU-S) can differentiate into erythrocytes, granulocytes, megakaryocytes and B lymphocytes. Although mast cell precursors are known to be present in the bone marrow, spleen, fetal liver and peripheral blood of mice, the relationship between the mast cell precursor and CFU-S has remained unclear. We have now made use of mice of two mutant genotypes to determine whether or not the tissue mast cell is a progeny of CFU-S. Giant granules of beige (C57BL/6-bg/bg, Chediak-Higashi syndrome) mice can be used for identification of the origin of both tissue mast cells and granulocytes, and WBB6F1-W/Wv mice are useful recipients because they lack tissue mast cells owing to a defect in mast cell precursors. We injected the cells from a single spleen colony into each WBB6F1-W/Wv mouse and demonstrated directly that the tissue mast cell is a progeny of CFU-S.     

Hydroxylation of menthols and cineoles withm-chloroperbenzoic acid

Summary Reaction of menthols and cineoles withm-chloroperbenzoic acid afforded tertiary, secondary, and primary alcohols, some of which were natural products having potent plant growth regulatory activity or were mammlianm metabolies.We thank Nippon Terpene Co. Ltd for their generous gift of the compounds used in this work and Drs M. Kido and Y. Fukuyama, Otsuka Pharmaceutical Co. Ltd, for measurement of high resolution mass spectra. The present work was supported in part by a Grant-in-Aid for Cancer Research from the Ministry of Health and Welfare.     

Activation of the ERK/MAPK pathway by an isoform of rap1GAP associated with G alpha(i)

Many receptors for neuropeptides and hormones are coupled with the heterotrimeric G(i) protein, which activates the p42/44 mitogen-activated protein kinase (ERK/MAPK) cascade through both the alpha- and betagamma-subunits of G(i). The betagamma-subunit activates the ERK/MAPK cascade through tyrosine kinase. Constitutively active G(alpha)i2 (gip2) isolated from adrenal and ovarian tumours transforms Rat-1 fibroblasts and also activates the ERK/MAPK cascade by an unknown mechanism. The ERK/MAPK pathway is activated by Ras, and is inhibited when the low-molecular-mass GTP-binding protein Rap1 antagonizes Ras function. Here we show that a novel isoform of Rapl GTPase-activating protein, called rap1GAPII, binds specifically to the alpha-subunits of the G(i) family of heterotrimeric G-proteins. Stimulation of the G(i)-coupled m2-muscarinic receptor translocates rap1GAPII from the cytosol to the membrane and decreases the amount of GTP-bound Rap1. This decrease in GTP-bound Rap1 activates ERK/MAPK. Thus, the alpha-subunit of G(i) activates the Ras-ERK/MAPK mitogenic pathway by membrane recruitment of rap1GAPII and reduction of GTP-bound Rap1.