Cardiac defects and renal failure in mice with targeted mutations in Pkd2

PKD2, mutations in which cause autosomal dominant polycystic kidney disease (ADPKD), encodes an integral membrane glycoprotein with similarity to calcium channel subunits. We induced two mutations in the mouse homologue Pkd2 (ref.4): an unstable allele (WS25; hereafter denoted Pkd2WS25) that can undergo homologous-recombination-based somatic rearrangement to form a null allele; and a true null mutation (WS183; hereafter denoted Pkd2-). We examined these mutations to understand the function of polycystin-2, the protein product of Pkd2, and to provide evidence that kidney and liver cyst formation associated with Pkd2 deficiency occurs by a two-hit mechanism. Pkd2-/- mice die in utero between embryonic day (E) 13.5 and parturition. They have structural defects in cardiac septation and cyst formation in maturing nephrons and pancreatic ducts. Pancreatic ductal cysts also occur in adult Pkd2WS25/- mice, suggesting that this clinical manifestation of ADPKD also occurs by a two-hit mechanism. As in human ADPKD, formation of kidney cysts in adult Pkd2WS25/- mice is associated with renal failure and early death (median survival, 65 weeks versus 94 weeks for controls). Adult Pkd2+/- mice have intermediate survival in the absence of cystic disease or renal failure, providing the first indication of a deleterious effect of haploinsufficiency at Pkd2on long-term survival. Our studies advance our understanding of the function of polycystin-2 in development and our mouse models recapitulate the complex human ADPKD phenotype.     

A new gene involved in X-linked mental retardation identified by analysis of an X;2 balanced translocation

X-linked forms of mental retardation (MR) affect approximately 1 in 600 males and are likely to be highly heterogeneous. They can be categorized into syndromic (MRXS) and nonspecific (MRX) forms. In MRX forms, affected patients have no distinctive clinical or biochemical features. At least five MRX genes have been identified by positional cloning, but each accounts for only 0.5%-1.0% of MRX cases. Here we show that the gene TM4SF2 at Xp11.4 is inactivated by the X breakpoint of an X;2 balanced translocation in a patient with MR. Further investigation led to identification of TM4SF2 mutations in 2 of 33 other MRX families. RNA in situ hybridization showed that TM4SF2 is highly expressed in the central nervous system, including the cerebral cortex and hippocampus. TM4SF2 encodes a member of the tetraspanin family of proteins, which are known to contribute in molecular complexes including beta-1 integrins. We speculate that through this interaction, TM4SF2 might have a role in the control of neurite outgrowth.     

棉织物的等离子体聚合涂覆及其拒水性研究

使用某种氟碳化合物的AC等离子体沉积方法 ,在棉织物表面涂覆一层很薄的憎水膜。影像接触角测试表明 ,仅仅经过 3 0s的涂覆处理 ,棉织物表面水接触角就可达 164°左右 ,获得超级憎水特性。棉织物的柔软性、保水率、回潮率、颜色变化、手感、透气性等都采用标准方法进行了详细研究 ,并与商用ScotchgardTM防水防污喷雾型保护剂涂覆的织物进行了比较。研究结果表明 ,除了回潮率基本相同外 ,等离子体涂覆织物的这些性能都优于保护剂涂覆织物的性能。同时 ,对加热后处理对涂层织物憎水性的影响进行了研究 ,结果表明 ,高温后处理有助于织物憎水性的提高。原子力显微镜和二次离子质谱研究结果显示 ,加热后处理后沉积膜的表面形态和化学性能都发生了变化 ,这种变化可能导致了织物憎水性能的改变     

The animal musks and a comment of their biogenesis

Summary The macrocyclic compounds occurring in animal glandular secretions are reviewed. Early hypotheses for their biogenesis from fatty acids via and -oxidations are found to be inadequate. Radio-active acetate was incorporated into macrocyclic ketones of muskrat (Ondatra sp.) preputial glandular secretion, but radiolabelled stearate, oleate, anda, -octadecandioic acid were not incorporated.Acknowledgment. We wish to thank Dr.W.J. Doude van Troostwijk, Research Institute for Nature Management, Arnhem, for his assistance in obtaining muskrats, and Mr J. Vellekoop, Leiden, for the Shakespeare quotations.     

The human PAX6 gene is mutated in two patients with aniridia.

Aniridia is an inherited ocular disorder of variable expressivity characterized by iris hypoplasia. A candidate aniridia gene, AN, which is the human homologue of the mouse Pax-6 gene, has recently been isolated by positional cloning from the WAGR region of 11p13. Here we describe mutations in this gene in two cases of sporadic aniridia, one detected at the DNA level and one at the RNA level, both of which are predicted to affect protein function. Mutations in Pax-6 have been described previously in Small eye, the proposed mouse model for aniridia. We present new phenotypic evidence for the validity of this mouse model.     

Association between pregnancy-associatedα 2-glycoprotein (α 2-PAG) and mixed leucocyte reaction determinants on the leucocyte surface

Summary ₂-PAG is present on the surface of mononuclear blood leucocytes and can be demonstrated predominantly on B-lymphocytes and monocytes. Pretreatment of cells with antibody to ₂-PAG leads to a marked reduction in Fc-rosette formation. Competitive blocking experiments with specific antisera reveal a particularly close asociation between ₂-PAG and MLR (mixed leucocyte reaction) determinants on the cell surface. These findings suggest one mechanism whereby ₂-PAG may modify cell-mediated immune responses.     

研究型大学图书馆的人力资源管理

引入研究型大学及其图书馆的定义，阐述了研究型大学图书馆进行人力资源管理的重要意义。进而提出了研究型大学图书馆人力资源管理的策略，包括改变人力资源管理理念，建立以人为本的人才管理机制，注重人才的使用和培养，充分调动馆员的积极性等。