Purification processes, ecological functions, planning and design of riparian buffer zones in agricultural watersheds

Two international meetings on ecological engineering, with a focus on riparian buffer zones, served as the source for selected papers in this special issue: (1) an International Workshop on Efficiency of Purification Processes in Riparian Buffer Zones: Their Design and Planning in Agricultural Watersheds, jointly organised by Hokkaido University, Japan, the National Agricultural Research Center for Hokkaido Region, Japan, Civil Engineering Research Institute of Hokkaido, Japan, and the Institute of Geography, University of Tartu, Estonia, and held from 5 to 9 November 2001 in Kushiro City, Hokkaido, Japan; and (2) an International Conference on Ecological Engineering for Landscape Services and Products, jointly organised by the International Ecological Engineering Society (IEES) and Lincoln University, Christchurch, New Zealand, and held from 25 to 29 November 2001 in Christchurch, New Zealand. At these two meetings, altogether 94 oral presentations (17 from invited speakers) and 15 posters by representatives from 21 countries were presented. The editorial paper highlights trends in investigation of the purification processes in riparian buffer zones as well as planning, design and management aspects of riparian buffers regarding the wide spectrum of their ecological functions; it characterises the two international meetings which served as sources for the selected papers and briefly explains the main aspects of these papers.     

SRPX2 is a novel chondroitin sulfate proteoglycan that is overexpressed in gastrointestinal cancer

SRPX2 (Sushi repeat-containing protein, X-linked 2) has recently emerged as a multifunctional protein that is involved in seizure disorders, angiogenesis and cellular adhesion. Here, we analyzed this protein biochemically. SRPX2 protein was secreted with a highly posttranslational modification. Chondroitinase ABC treatment completely decreased the molecular mass of purified SRPX2 protein to its predicted size, whereas heparitinase, keratanase and hyaluroinidase did not. Secreted SRPX2 protein was also detected using an anti-chondroitin sulfate antibody. These results indicate that SRPX2 is a novel chondroitin sulfate proteoglycan (CSPG). Furthermore, a binding assay revealed that hepatocyte growth factor dose-dependently binds to SRPX2 protein, and a ligand-glycosaminoglycans interaction was speculated to be likely in proteoglycans. Regarding its molecular architecture, SRPX2 has sushi repeat modules similar to four other CSPGs/lecticans; however, the molecular architecture of SRPX2 seems to be quite different from that of the lecticans. Taken together, we found that SRPX2 is a novel CSPG that is overexpressed in gastrointestinal cancer cells. Our findings provide key glycobiological insight into SRPX2 in cancer cells and demonstrate that SRPX2 is a new member of the cancer-related proteoglycan family.     

Poecillastrin D: a new cytotoxin of the chondropsin class from marine sponge Jaspis serpentina

Poecillastrin D (2) was isolated together with poecillastrin C (1) from the deep sea sponge, Japsis serpentina. Its structure was elucidated to be that of a macrolide lactam by spectroscopic methods. These compounds showed potent cytotoxicity against various tumor cell lines.     

Electron microscope researches on the ultrastructure of nucleoli in animal tissues

Summary On the basis of electron microscopy of nucleoli in various physiological stages of similar and different cells, it is assumed that the nucleolonemata appear for the first time in the pre-mitotic stage and subsequently the nucleolus-associated body makes its appearance.The nucleolonema is composed of helically coiled filaments 50 Å in diameter.The nucleolus-associated body comprises tightly packed filaments about 15–30 Å thick which are helically coiled.     

Insulin activates CCAAT/enhancer binding proteins and proinflammatory gene expression through the phosphatidylinositol 3-kinase pathway in vascular smooth muscle cells

Phosphatidylinositol 3-kinase (PI3K) is a key molecule mediating signals of insulin in vascular smooth muscle cells (VSMCs). To examine the effect of chronic activation of PI3K on the gene expression of VSMCs, membrane-targeted p110CAAX, a catalytic subunit of PI3K, was overexpressed in rat VSMCs by adenovirus-mediated gene transfer. Similar to insulin's effects, cells overexpressing p110CAAX exhibited a 10- to 15-fold increase in monocyte chemoattractant protein-1 (MCP-1) mRNA expression as compared with the control cells. Electrophoretic mobility shift assay analysis showed that the overexpression of p110CAAX activated neither the NF-kappaB binding nor the activator protein (AP-1) binding activities. We found that two CCAAT/enhancer binding protein (C/EBP) binding sites located between 2.6 and 3.6 kb upstream of the MCP-1 gene were responsible for the induction by p110CAAX. The overexpression of C/EBP-beta and C/EBP-delta but not C/EBP-alpha caused 6- to 8-fold induction of MCP-1 promoter activity. Consistently, the overexpression of p110CAAX as well as insulin induced mRNA expression and nuclear expression of C/EBP-beta and C/EBP-delta in VSMCs. These results clearly indicate that the activation of PI3K induced proinflammatory gene expression through activating C/EBP-beta and C/EBP-delta but not NF-kappaB, which may explain the proinflammatory effect of insulin in the insulin-resistant state.     

Microbial Community in Black Rust Exposed to Hot Ridge Flank Crustal Fluids

During Integrated Ocean Drilling Program Expedition 301, we obtained a sample of black rust from a circulation obviation retrofit kit (CORK) observatory at a borehole on the eastern flank of Juan de Fuca Ridge. Due to overpressure, the CORK had failed to seal the borehole. Hot fluids from oceanic crust had discharged to the overlying bottom seawater and resulted in the formation of black rust analogous to a hydrothermal chimney deposit. Both culture-dependent and culture-independent analyses indicated that the black-rust-associated community differed from communities reported from other microbial habitats, including hydrothermal vents at seafloor spreading centers, while it shared phylotypes with communities previously detected in crustal fluids from the same borehole. The most frequently retrieved sequences of bacterial and archaeal 16S rRNA genes were related to the genera Ammonifex and Methanothermococcus, respectively. Most phylotypes, including phylotypes previously detected in crustal fluids, were isolated in pure culture, and their metabolic traits were determined. Quantification of the dissimilatory sulfite reductase (dsrAB) genes, together with stable sulfur isotopic and electron microscopic analyses, strongly suggested the prevalence of sulfate reduction, potentially by the Ammonifex group of bacteria. Stable carbon isotopic analyses suggested that the bulk of the microbial community was trophically reliant upon photosynthesis-derived organic matter. This report provides important insights into the phylogenetic, physiological, and trophic characteristics of subseafloor microbial ecosystems in warm ridge flank crusts.     

Cav2.1 Voltage-dependent Ca<Superscript>2+</Superscript> Channel Current is Inhibited by Serum from Select Patients with Guillain-Barré Syndrome

To investigate the pathophysiological mechanisms of immune-mediated peripheral neuropathies, we studied the effects of sera from patients with Guillain-Barré syndrome (GBS) on the Cav2.1 voltage-dependent calcium channel (VDCC) current in Purkinje cells. Using the whole-cell recording technique, Cav2.1 VDCC current was measured in cerebellar Purkinje cells in the presence of serum from GBS patients with acute motor axonal neuropathy (AMAN) or acute inflammatory demyelinating polyneuropathy (AIDP). The AMAN patient sera significantly inhibited the Cav2.1 VDCC current compared with healthy volunteer sera, and this inhibition was fully reversible by washing out the AMAN serum. Similarly, IgG purified from AMAN sera also inhibited the Cav2.1 VDCC current. However, the activation and inactivation kinetics of the Cav2.1 VDCC currents were not affected by serum from an AMAN patient. Moreover, the VDCC current of Purkinje cells was also inhibited by IgG anti-GM1 monoclonal antibody (anti-GM1 mAb). In an immunocytochemical study using double fluorescence staining, Purkinje cells were stained by monoclonal IgG anti-GM1 mAb. In contrast, AIDP patient and healthy volunteer sera did not affect the Cav2.1 VDCC current. These results suggest that in some case of GBS, particularly of AMAN patients with IgG anti-GM1 mAb, muscle weakness may be induced by dysfunction of Cav2.1 VDCC functioning at the motor nerve terminals. Special issue article in honor of Dr. George DeVries.     

高频度微卫星不稳定性大肠癌"修饰型"微卫星变化与MLH1及KRAS基因突变密切相关

本研究通过方法学的改良和观察方式的创新试图阐明这种现象的原因.微卫星非传统的检测方法仅能实现微卫星定性检测,我所在的研究组开发了自动片段分析双荧光标识技术,提高了微卫星检测的感度和重复性,并实现了微卫星片段变化长度的定量.小于6碱基的微卫星变化被定义为修饰型微卫星不稳定,大于8碱基的变化被定义为跳跃型微卫星不稳定,它们的电泳谱截然不同.前者表现为在非肿瘤来源微卫星位点基础上的增加或减少,后者表现为距离非肿瘤微卫星片段远隔部位的新波形的出现.通过研究我们发现,在DNA错配修复缺陷细胞系及基因敲除大鼠自发肿瘤样本,仅有修饰型微卫星不稳定性检出;在人类DNA错配修复缺陷细胞系连续80次传代也没有检出跳跃型变化.跳跃型变化不能通过简单重复序列不稳定基础上的增加或减少的累加而获得.在76例散发大肠癌,我们检测了微卫星不稳定性,KRAS基因突变,并对高频度微卫星不稳定性病例的两个主要DNA错配修复基因MSH2和MLHl进行了全长测序.我们发现,在大肠癌,按频度的传统分类与按波形变化的分类有高度的一致性,高频度微卫星不稳定性病例均检测到跳跃型表现,低频度微卫星不稳定性都表现为修饰型变化.在12例高频度微卫星不稳定病例,有三例检出了跳跃型和修饰型同时存在微卫星不稳定的特殊表型,这3例均检出KRAS的突变,更有趣的是该3例病例也同时检出了DNA错配修复基因MLH1的变异.而在其他9例高频度微卫星不稳定病例,KRAS突变及MLH1、MSH2交变未检出.通过对突变谱的分析我们还发现,修饰型微卫星不稳定与KTAS基因12号密码子的转换型突变高度相关,而微卫星稳定的病例检出的KRAS基因12号密码子突变多为颠换型突变.修饰型微卫星不稳定表型检出的高频度转换突变可由DNA错配修复缺陷的分子背景解释.通过本研究,我们认为以波形为基础的微卫星不稳定新分型可能是解决目前微卫星研究领域矛盾的一个选项.一直公认为高频度微卫星不稳定性是"真正"的DNA错配修复缺陷表型,我们的研究提示实际上高频度微卫星的可能是多元的.修饰型微卫星不稳定与DNA错配修复缺陷直接关联,而跳跃型微卫星不稳定的原因尚未阐明.在高频度为微型不稳定中,携带修饰型变化的病例可以通过DNA错配修复系统缺陷来解释其病因.