Erythrocyte deformability improving action of β-pyridylcarbinol tartrate

Summary -Pyridylcarbinol tartrate was found to prevent the hyperosmotically induced worsening of filterability of rat erythrocytes after in vivo treatments. The effect is attributed to the prevention of the morphological change of the erythrocytes from normal discocytes to echinocytes. The study was made using a scanning electron microscope.Acknowledgment. The authors are grateful to Prof. T. Yanagisawa and Mr I. Uemura for providing them the opportunity to learn about scanning electron microscopy.     

Structural basis for specific cleavage of Lys 63-linked polyubiquitin chains

Deubiquitinating enzymes (DUBs) remove ubiquitin from conjugated substrates to regulate various cellular processes. The Zn(2+)-dependent DUBs AMSH and AMSH-LP regulate receptor trafficking by specifically cleaving Lys 63-linked polyubiquitin chains from internalized receptors. Here we report the crystal structures of the human AMSH-LP DUB domain alone and in complex with a Lys 63-linked di-ubiquitin at 1.2 A and 1.6 A resolutions, respectively. The AMSH-LP DUB domain consists of a Zn(2+)-coordinating catalytic core and two characteristic insertions, Ins-1 and Ins-2. The distal ubiquitin interacts with Ins-1 and the core, whereas the proximal ubiquitin interacts with Ins-2 and the core. The core and Ins-1 form a catalytic groove that accommodates the Lys 63 side chain of the proximal ubiquitin and the isopeptide-linked carboxy-terminal tail of the distal ubiquitin. This is the first reported structure of a DUB in complex with an isopeptide-linked ubiquitin chain, which reveals the mechanism for Lys 63-linkage-specific deubiquitination by AMSH family members.     

Imaging of Rab5 activity identifies essential regulators for phagosome maturation

Efficient phagocytosis of apoptotic cells is crucial for tissue homeostasis and the immune response. Rab5 is known as a key regulator of the early endocytic pathway and we have recently shown that Rab5 is also implicated in apoptotic cell engulfment; however, the precise spatio-temporal dynamics of Rab5 activity remain unknown. Here, using a newly developed fluorescence resonance energy transfer biosensor, we describe a change in Rab5 activity during the engulfment of apoptotic thymocytes. Rab5 activity on phagosome membranes began to increase on disassembly of the actin coat encapsulating phagosomes. Rab5 activation was either continuous or repetitive for up to 10 min, but it ended before the collapse of engulfed apoptotic cells. Expression of a dominant-negative mutant of Rab5 delayed this collapse of apoptotic thymocytes, showing a role for Rab5 in phagosome maturation. Disruption of microtubules with nocodazole inhibited Rab5 activation on the phagosome membrane without perturbing the engulfment of apoptotic cells. Furthermore, we found that Gapex-5 is the guanine nucleotide exchange factor essential for Rab5 activation during the engulfment of apoptotic cells. Gapex-5 was bound to a microtubule-tip-associating protein, EB1, whose depletion inhibited Rab5 activation during phagocytosis. We therefore propose a mechanistic model in which the recruitment of Gapex-5 to phagosomes through the microtubule network induces the transient Rab5 activation.     

A negative association of HLA-BW52 with Graves' disease and insulin-dependent diabetes mellitus with juvenile onset among Japanese population

The present study demonstrated that a decreased frequency of HLA-BW52 was a common characteristic shared by the patients with Graves' disease and insulin-dependent diabetes mellitus with juvenile onset among Japanese.     

Ultrastructural aspects of the pancreatic islets in carps of spontaneous diabetes mellitus

Zusammenfassung Elektronenmikroskopisch konnten in den Langerhansschen Inseln im Pankreas von normalen und diabetischen Fischen bestimmte Typen von Drüsenzellen differenziert werden, nämlich A-, B- und D-Zellen sowie klare Zellen. Bei diabetischen Fischen ist vor allem die sehr starke Vermehrung sogenannter klarer Zellen typisch.     

Electroencephalogram potentials evoked by hemi-retinal stimulation

Zusammenfassung Als Reaktion auf Reizung der lateralen Gesichtsfeldhälfte wurden evozierte Potentiale der Hirnrinde des Menschen registriert. Reizung der einen Gesichtshälfte erzeugte frühzeitig ein Maximum der Potentiale der gegenseitigen Hemisphäre sowie Phasenumkehr der Potentiale der gleichseitigen Hemisphäre.     

α-Adrenoceptor blocking action of hymenin,a novel marine alkaloid

Summary In the rabbit isolated aorta, hymenin (10^–6 M) a novel marine alkaloid, caused a parallel rightward shift of the dose-response curve for norepinephrine without affecting that for histamine or KCl, suggesting that hymenin is a competitive antagonist of -adrenoceptors in vascular smooth muscles.Acknowledgments. We thank Ms A. Kajiwara and Ms M. Hamashima of this institute for their technical assistance, and Prof. Y. Hirata of Meijo University for his encouragement.     

利用近红外彩色成像技术监测松萎蔫病 Katsunori Nakamura, Mamoru Takehana, Tsuneo Itagaki, Hayato Tashiro,Kazumasa Ohta,Osamu Nakakita

有效监测患病株方法的缺失是导致对松萎蔫病难以成功控制的主要原因之一。利用航空手段调查该病导致的针叶颜色变化已被证明是一种可靠的方法。为了克服该方法固有的缺点，笔者引用了近红外彩色胶片航拍方法。该项技术在获得正摄航拍图像时，通过图像处理可以增强松针颜色变化，获得较直接拍摄图像更明显的色差。因为图像可以在室内仔细处理，因此能解决飞行时间缺乏等问题。但是，该方法也存在对被压木无法获得其影像而漏检的缺陷。笔者研发的计算机软件可以将目标树标记在计算机图像文件上，并且标记树的地理位置数据和背景航拍图像并传输到装有内置GPS接收器的掌上电脑中，借助软件产生的图像导航定位系统，有利于地面接近标记树，从而可以现场检查和校正标记树的数据，并将修正数据传回至主机。此方法利用最新航拍图像技术建立对每株树处理和管理的连续资料，大大改善了防控松萎蔫病的措施。     

Development of a Mobile Sensing Unit and Its Prototype Implementation

This paper represents a design and development of a mobile sensing unit as well as its prototype implementation for railway track monitoring. The unit consists of an ultra-small personal computer (PC), a global positioning system (GPS) receiver, an accelerometer and an ADC (Analog/Digital Converter) so that the unit can trace the route while capturing an acceleration response of a passenger vehicle. The unit enables more frequent and qualitative data acquisition compared with traditional and the state of the practice railway track inspection equipments. Locating disorder is the key of our unit, which has a reasonable accuracy of positioning with GPS data, existing facilities landmarks, and car acceleration responses. The proposed unit is a promising device for efficient properties management of railway agencies. The prototype implementation shows a result that car acceleration responses are related with the track displacements in low frequencies. The results also imply that sensor settlement on a vehicle floor, not axes or bogies, is effective for capturing track vertical displacements.     

航天器的稳定自旋对双程多普勒追踪测量的影响

多普革追踪是航天器测量的主要手段之一，在通过对绕月轨道变化的观测来精确测定月球引力场球协函数高阶项的研究中，要求在数十秒采样间隔内得的多普勒频率漂移精度要达到１ＭＨｚ，然而，由于采用了自转稳定姿态控制模式，航天器的旋转会对多普勒测量产生影响，介绍了这种影响以及消除这种影响的方法。