Chondroinduction and chondrocytic maintenance in three-dimensional culture systems

Thesis (Ph.D. in Medical Sciences)--University of Tsukuba, (B), no. 1243, 1997.1.3

Human telomerase exists in two distinct active complexes in vivo

金沢大学がん研究所Telomerase, a stable complex of telomerase reverse transcriptase (TERT) and template RNA (TERC), is responsible for telomere maintenance. During purification trials of recombinant human telomerase of the two components reconstituted in insect cells, we identified two complexes of human telomerase of molecular masses 680 and 380 kDa, both of which retain telomerase activity in vitro. We show here that the former complex does not include Hsp90 (heat shock protein 90) and its telomerase activity is resistant to Hsp90 inhibitors, whereas the latter contains Hsp90 and its telomerase activity is sensitive to Hsp90 inhibitors. N-terminal of FLAG-hTERT in the former is exposed, as this complex was efficiently purified with anti-FLAG M2 affinity resin. We also identified two different telomerase complexes in HeLa cells, in addition to ectopically expressed hTERT. Most of endogenous hTERT and FLAG-hTERT was detected around 680 kDa. These two complexes in HeLa cells have the same properties as their respective reconstituted telomerases. The unstable property of the telomerase complex with Hsp90, especially in the presence of Hsp90 inhibitors, was due to proteasome-mediated degradation of hTERT, since proteasome inhibitors prevented hTERT degradation in vivo. To our knowledge, this is the first demonstration of two distinct active complexes of human telomerase ectopically expressed in insect and mammalian cells. © 2007 The Japanese Biochemical Society

PoGOLite - A High Sensitivity Balloon-Borne Soft Gamma-ray Polarimeter

We describe a new balloon-borne instrument (PoGOLite) capable of detecting 10% polarisation from 200mCrab point-like sources between 25 and 80keV in one 6 hour flight. Polarisation measurements in the soft gamma-ray band are expected to provide a powerful probe into high-energy emission mechanisms as well as the distribution of magnetic fields, radiation fields and interstellar matter. At present, only exploratory polarisation measurements have been carried out in the soft gamma-ray band. Reduction of the large background produced by cosmic-ray particles has been the biggest challenge. PoGOLite uses Compton scattering and photo-absorption in an array of 217 well-type phoswich detector cells made of plastic and BGO scintillators surrounded by a BGO anticoincidence shield and a thick polyethylene neutron shield. The narrow FOV (1.25msr) obtained with well-type phoswich detector technology and the use of thick background shields enhance the detected S/N ratio. Event selections based on recorded phototube waveforms and Compton kinematics reduce the background to that expected for a 40-100mCrab source between 25 and 50keV. A 6 hour observation on the Crab will differentiate between the Polar Cap/Slot Gap, Outer Gap, and Caustic models with greater than 5 sigma; and also cleanly identify the Compton reflection component in the Cygnus X-1 hard state. The first flight is planned for 2010 and long-duration flights from Sweden to Northern Canada are foreseen thereafter.Comment: 11 pages, 11 figures, 2 table

大学女子ﾊﾞﾚｰﾎﾞｰﾙ選手の栄養素等摂取状況および身体的特徴

本研究は大学女子ﾊﾞﾚｰﾎﾞｰﾙ部員33名を対象に栄養素等摂取状況および身体的特徴を調査することを目的とした｡ﾊﾞﾚｰ群の平均ｴﾈﾙｷﾞｰ摂取量は 1,708±425kcal､炭水化物平均摂取量は 3.9±1.3g/kg､たんぱく質平均摂取量は 0.9±0.2g/kg であった｡炭水化物およびたんぱく質摂取量は低く､ｴﾈﾙｷﾞｰの摂取不足が推定された｡ﾋﾞﾀﾐﾝおよびﾐﾈﾗﾙでは､ﾋﾞﾀﾐﾝ B1､B2 を除いて､食事摂取基準の推定平均必要量を下回っていた｡また､本研究のﾊﾞﾚｰ群の平均体脂肪率は21.1±5.2%であった｡今後は除脂肪量の減少と体脂肪量の増加が起こらないように､対象者の身体状況の変化を確認しながら､栄養教育を行っていく必要があると思われる｡The purpose of this study was to collect data on nutrient intakes and body characteristics of 33 female college volleyball players. The mean energy, carbohydrate(kg-1･day-1), and protein(kg-1･day-1)intakes were 1,708±425kcal, 3.9±1.3g･kg-1･day-1, and 0.9±0.2g･kg-1･day-1, respectively. It was suggested that the mean energy intake was inadequate, because the mean carbohydrate(kg-1･day-1)and protein(kg-1･day-1)intakes were low. The mean intakes of vitamins and minerals were lower than the estimated average requirement, except vitamin B1 and B2. The mean percentage of body fat was 21.1±5.2%. The results of this study suggest that it is necessary to implement nutrition education as well as monitor changes in the players\u27body composition to prevent a decrease in free fat mass and an increase in fat mass

大学ｽﾎﾟｰﾂ選手に対する実践的栄養教育

ｽﾎﾟｰﾂ選手の競技力向上に関して､食事管理が重要であることは認識されつつあるが､選手自身による食事管理は難しく栄養素等の過不足を起こしていることが多い｡選手自身による食事管理能力の修得と､実践的栄養教育に必要な内容の明確化を目的として､大学ﾊﾞﾚｰﾎﾞｰﾙ･空手道選手に栄養教育を伴う調理実習を行い､知識､技術､意識に関するｱﾝｹｰﾄ調査を行った｡結果は､5段階評価の｢そう思う､ややそう思う､どちらともいえない､あまりそう思わない､そう思わない｣を､順に｢5､4､3､2､1点｣として評価した｡その結果､評価平均値は空手群における知識面に関する1つの項目を除き､4を超えており高い評価が得られ､ｽﾎﾟｰﾂ選手自身による食事管理への寄与が示唆された｡Dietary management is important for athletes in order to improve their performance. However, such management is difficult for them, and they often take nutrients in inappropriate amounts. We herein provided athletes with nutrition education involving cooking practice, with the aim of developing their skills for dietary management, and clarifying the contents needed for practical nutrition education. University volleyball players and karate practitioners received nutrition education, and were administered a questionnaire inquiring about their knowledge, skills, and awareness in order to determine the effects of the education. The question items were scored on a 5-point grading scale: the answers “I agree”, “I slightly agree”, “no applicable answer”, “I slightly disagree”, and “I disagree” equaled 5, 4, 3, 2, and 1 point, respectively. For all question items, except for 1 knowledge-related item, karate practitioners showed an average of >4 points, suggesting the beneficial effects of nutrition education for athletes\u27 dietary management

The X-ray Polarization Probe mission concept

The X-ray Polarization Probe (XPP) is a second generation X-ray polarimeter following up on the Imaging X-ray Polarimetry Explorer (IXPE). The XPP will offer true broadband polarimetery over the wide 0.2-60 keV bandpass in addition to imaging polarimetry from 2-8 keV. The extended energy bandpass and improvements in sensitivity will enable the simultaneous measurement of the polarization of several emission components. These measurements will give qualitatively new information about how compact objects work, and will probe fundamental physics, i.e. strong-field quantum electrodynamics and strong gravity.Comment: submitted to Astrophysics Decadal Survey as a State of the Profession white pape

X-ray polarimetry reveals the magnetic field topology on sub-parsec scales in Tycho's supernova remnant

Supernova remnants are commonly considered to produce most of the Galactic cosmic rays via diffusive shock acceleration. However, many questions about the physical conditions at shock fronts, such as the magnetic-field morphology close to the particle acceleration sites, remain open. Here we report the detection of a localized polarization signal from some synchrotron X-ray emitting regions of Tycho's supernova remnant made by the Imaging X-ray Polarimetry Explorer. The derived polarization degree of the X-ray synchrotron emission is 9+/-2% averaged over the whole remnant, and 12+/-2% at the rim, higher than the 7-8% polarization value observed in the radio band. In the west region the polarization degree is 23+/-4%. The X-ray polarization degree in Tycho is higher than for Cassiopeia A, suggesting a more ordered magnetic-field or a larger maximum turbulence scale. The measured tangential polarization direction corresponds to a radial magnetic field, and is consistent with that observed in the radio band. These results are compatible with the expectation of turbulence produced by an anisotropic cascade of a radial magnetic-field near the shock, where we derive a magnetic-field amplification factor of 3.4+/-0.3. The fact that this value is significantly smaller than those expected from acceleration models is indicative of highly anisotropic magnetic-field turbulence, or that the emitting electrons either favor regions of lower turbulence, or accumulate close to where the magnetic-field orientation is preferentially radially oriented due to hydrodynamical instabilities.Comment: 31 pages, 7 figures, 3 tables. Accepted for publication in ApJ. Revised versio