<ORIGINAL ARTICLE>Establishment and characteristics of a cell line derived from osteosarcoma induced by ^<32>P in the rat.

骨肉腫細胞株はヒト骨肉腫治療の実験モデルになるばかりでなく,骨形成を示すため骨代謝の研究に対しても有用な実験モデルとなりうる。しかし,可移植性骨肉腫株やその細胞株は今日においても非常に少ない。われわれはすでに^Pで誘発した可移植性骨肉腫を報告した。この腫瘍は継代移植においても骨形成能を維持している。今回の実験はこの骨腫瘍の細胞株を樹立すること,ならびにその生物学的特長を検索することである。その結果,1.ラット骨肉腫の細胞株(MSK,武藤-佐藤-金沢)が樹立された。2.この細胞株はin vitroにおいて強いアルカリフォスファターゼ活性とコラーゲン形成能を示した。3.MSK細胞を同系ラットの背部皮下に移植すると骨形成能を示した。4.ミリポアフィルターを用いたin VIVO骨形成実験では,フィルターの外側に骨形成が認められた。5.以上の結果より,MSK細胞は骨形成能を示すだけでなく骨誘導能の可能性が示唆された。それゆえ,この細胞株は骨芽細胞の特性の検索ばかりでなく骨誘導の研究にも有用なモデルであると考える。To study the medical treatment of human osteosarcoma there is a need for experimental tumor models Moreover, osteoblastic cell line is a useful model for research of the bone and mineral metabolism. Even today, a few transplantable bone-forming osteosarcomas and their cell lines are available Previously we have reported transplantation of osteosarcoma induced by administration of ^P This tumor retains the osteoid-forming ability even in serial transplantations In the present study, we established the cell line of our transplantable ratosteosarcoma and investigated the characteristics of the cell line The results were as follows 1. A cell line (MSK, Muto-Sato-Kanazawa) of rat osteosarcoma was established 2. The cell line showed intense staining of alkaline phosphatase and collagen synthesis in vitro. 3. MSK cell line also maintained the bone-forming ability when it was inoculated sub cutaneously into the back of syngenic rats 4. Osteogenesis outside a Millipore filter by MSK cells was demonstrated in vivo. 5. It was suggested that MSK cells had not only bone-forming ability but also bone-inductive ability. Therefore, MSK cell line would be a useful model for the study on the property of osteoblast and bone inductio

Polaron Excitations in Doped C60: Effects of Disorders

Effects on C$_{60}$ by thermal fluctuations of phonons, misalignment of C$_{60}$ molecules in a crystal, and other intercalated impurities (remaining C$_{70}$, oxygens, and so on) are simulated by disorder potentials. The Su-Schrieffer-Heeger--type electron-phonon model for doped C$_{60}$ is solved with gaussian bond disorders and also with site disorders. Sample average is performed over sufficient number of disorder configurations. The distributions of bond lengths and electron densities are shown as functions of the disorder strength and the additional electron number. Stability of polaron excitations as well as dimerization patterns is studied. Polarons and dimerizations in lightly doped cases (C$_{60}^{-1,-2}$) are relatively stable against disorders, indicated by peak structures in distribution functions. In more heavily doped cases, the several peaks merge into a single peak, showing the breakdown of polaron structures as well as the decrease of the dimerization strength. Possibility of the observation of polaronic lattice distortions and electron structures in doped C$_{60}$ is discussed.Comment: Note: This manusript was accepted for publication in Physical Review B. Figures will be sent to you via snail (conventional) mai

Lattice distortion and energy level structures in doped C_{60} and C_{70} studied with the extended Su-Schrieffer-Heeger model: Polaron excitations and optical absorption

We extend the Su-Schrieffer-Heeger model of polyacetylene to C_{60} and C_{70} molecules, and solve numerically. The calculations of the undoped systems agree well with the known results. When the system (C_{60} or C_{70}) is doped with one or two electrons (or holes), the additional charges accumulate almost along an equatorial line of the molecule. The dimerization becomes weaker almost along the same line. Two energy levels intrude largely in the gap. The intrusion is larger in C_{70} than in C_{60}. Therefore, ``polarons'' are predicted in doped buckminster- fullerenes. We calculate optical absorption coefficient for C_{60} in order to look at how ``polarons'' will be observed. It is predicted that there appears a new peak at the lower energy than the intergap transition peaks. It is also found that C_{60} and C_{70} are related mutually with respect to electronical structures as well as lattice geometries. (to be published in Phys. Rev. B 45, June 15 issue)Comment: 21 page

A theoretical investigation of ferromagnetic tunnel junctions with 4-valued conductances

In considering a novel function in ferromagnetic tunnel junctions consisting of ferromagnet(FM)/barrier/FM junctions, we theoretically investigate multiple valued (or multi-level) cell property, which is in principle realized by sensing conductances of four states recorded with magnetization configurations of two FMs; that is, (up,up), (up,down), (down,up), (down,down). To obtain such 4-valued conductances, we propose FM1/spin-polarized barrier/FM2 junctions, where the FM1 and FM2 are different ferromagnets, and the barrier has spin dependence. The proposed idea is applied to the case of the barrier having localized spins. Assuming that all the localized spins are pinned parallel to magnetization axes of the FM1 and FM2, 4-valued conductances are explicitly obtained for the case of many localized spins. Furthermore, objectives for an ideal spin-polarized barrier are discussed.Comment: 9 pages, 3 figures, accepted for publication in J. Phys.: Condens. Matte

ETS-VIIIを利用した災害医療支援のための立体画像伝送の研究

It is pointed out that a lot of people are dead or injured, and the functions of the infrastructure are lost such as the cellular phone, the gas , water service, electricity, and roads, when the communication network system on the ground is broken down by wide-scale disaster. In order to overcome such inconvenient conditions, the construction of Tel-Radiology system not depending on the situations of the ground should be established rapidly. In addition, if 3D image technology is applied for Tel-Radiology, it may lead to the contribution of the triage to the efficiently improved operations in several areas. In this paper, we studied the capability of 3D image technology applying to Tel-Radiology. As a result of sufficient investment of bit stream data transmission of stereo 3D moving pictures employed the ETS-VIII satellite , it is found that the proposed system function well in the experiment assuming a telemedicine.