76
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Aoyagi S, Toda S, Nishibori E, Kuroiwa Y, Adachi T, Ohishi Y, Takata M, Sakata M. High pressure effect on bonding nature in KMnF 3. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305080645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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77
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Misaki S, Ogura T, Aoyagi S, Nishibori E, Sakata M. Ab-initio structure determination of two kinds of forma for adrenal cortical hormone, predonisolone. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305079730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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78
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Kubota Y, Takata M, Matsuda R, Kitaura R, Kitagawa S, Kobayashi TC, Kato K, Sakata M. Direct observation of hydrogen molecules adsorbed in a coordination polymer. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305082917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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79
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Tada M, Ishikawa S, Sakata M, Ohkubo K, Kyomen T, Nishibori E, Sasaki S. Maximum-entropy and Fourier study on electron density of MnO, LaCoO 3and MgSiO 3". Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305082218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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80
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Nishibori E, Fujishiro Y, Sakata M, Kobayashi A, Takata M, Kobayashi H. The structure determination of single-component molecular-metal. Acta Crystallogr A 2005. [DOI: 10.1107/s0108767305093323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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81
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Aoyagi S, Kato K, Ota A, Yamochi H, Saito G, Suematsu H, Sakata M, Takata M. Direct observation of charge ordering in (EDO-TTF) 2PF 6. Acta Crystallogr A 2004. [DOI: 10.1107/s0108767304096461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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82
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Amenomori M, Ayabe S, Cui SW, Ding LK, Ding XH, Feng CF, Feng ZY, Gao XY, Geng QX, Guo HW, He HH, He M, Hibino K, Hotta N, Hu H, Hu HB, Huang J, Huang Q, Jia HY, Kajino F, Kasahara K, Katayose Y, Kato C, Kawata K, Le GM, Li JY, Lu H, Lu SL, Meng XR, Mizutani K, Mori S, Mu J, Munakata K, Nanjo H, Nishizawa M, Ohnishi M, Ohta I, Onuma H, Ouchi T, Ozawa S, Ren JR, Saito T, Sakata M, Sasaki T, Shibata M, Shiomi A, Shirai T, Sugimoto H, Takita M, Tan YH, Tateyama N, Torii S, Tsuchiya H, Udo S, Utsugi T, Wang BS, Wang H, Wang X, Wang YG, Wu HR, Xue L, Yamamoto Y, Yan CT, Yang XC, Yasue S, Ye ZH, Yu GC, Yuan AF, Yuda T, Zhang HM, Zhang JL, Zhang NJ, Zhang XY, Zhang Y, Zhou XX. Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun. PHYSICAL REVIEW LETTERS 2004; 93:061101. [PMID: 15323615 DOI: 10.1103/physrevlett.93.061101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Revised: 05/03/2004] [Indexed: 05/24/2023]
Abstract
We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.
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83
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Endo T, Haraguchi K, Cipriano F, Simmonds MP, Hotta Y, Sakata M. Contamination by mercury and cadmium in the cetacean products from Japanese market. CHEMOSPHERE 2004; 54:1653-1662. [PMID: 14675844 DOI: 10.1016/j.chemosphere.2003.09.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cetaceans hunted coastally in Japan include several species of odontocete (dolphins, porpoises and beaked whales), and fresh and frozen red meat and blubber, as well as boiled internal organs, such as liver, lung, kidney and small intestine, are still sold for human consumption. Furthermore, red meat and blubber products originating from mysticete minke whales caught in the Antarctic and Northern Pacific are also sold for human consumption. We surveyed mercury and cadmium contamination levels in boiled liver, lung, kidney and red meat products being marketed in Japanese retail outlets. We also analyzed the DNA of these products to obtain information concerning gender and species. Total mercury (T-Hg) and methyl mercury (M-Hg) contamination levels in all the cetacean products were markedly higher in odontocete species than in mysticete species, and slightly higher in females than in males. T-Hg contamination in the organs was seen in the following order: boiled liver>boiled kidney=boiled lung>red meat. In particular, T-Hg concentrations in the boiled liver were high enough to cause acute intoxication even from a single ingestion: the mean +/-SD (range) of T-Hg was 388+/-543 (0.12-1980) microg/wetg. In contrast, although M-Hg contamination in the liver was not markedly higher than that in other organs, M-Hg contamination was in the following order: boiled liver>odontocete red meat>boiled kidney>boiled lung. The contamination levels of T-Hg and M-Hg in odontocete red meat, the most popular whale product, were 8.94+/-13.3 and 5.44+/-5.72 microg/wetg, respectively. These averages exceeded the provisional permitted levels of T-Hg (0.4 microg/wetg) and M-Hg (0.3 microg/wetg) in marine foods set by the Japanese Ministry of Health, Labor and Welfare by 22 and 18 times, respectively, suggesting the possibility of chronic intoxication by T-Hg and M-Hg with frequent consumption of odontocete red meat. Cadmium contamination levels in boiled liver, kidney and lung were 8.59+/-12.0, 10.4+/-8.6 and 1.66+/-1.27 (microg/wetg), respectively.
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84
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Kato K, Moritomo Y, Takata M, Sakata M, Umekawa M, Hamada N, Ohkoshi S, Tokoro H, Hashimoto K. Direct observation of charge transfer in double-perovskite-like RbMn[Fe(CN)6]. PHYSICAL REVIEW LETTERS 2003; 91:255502. [PMID: 14754125 DOI: 10.1103/physrevlett.91.255502] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2003] [Indexed: 05/24/2023]
Abstract
The charge density distribution has been determined for a transition metal cyanide, RbMn[Fe(CN)(6)], by means of the maximum entropy-Rietveld method combined with the highly angularly resolved synchrotron radiation x-ray powder diffraction at SPring-8 BL02B2. We directly observed a charge transfer from the Mn site to the Fe site in the low-temperature phase. On the basis of a local density approximation calculation, we discuss the origin for the anisotropic bonding electron distribution around the Mn3+ ion in the low-temperature phase.
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85
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Sakata M, Masuko-Hongo K, Nakamura H, Onuma H, Tsuruha JI, Aoki H, Nishioka K, Kato T. Osteoarthritic articular chondrocytes stimulate autologous T cell responses in vitro. Clin Exp Rheumatol 2003; 21:704-10. [PMID: 14740448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
OBJECTIVE To clarify the presence of specific T cell immune response to autologous chondrocytes in patients with osteoarthritis (OA). METHODS Peripheral blood mononuclear cells obtained from OA or post-traumatic patients were co-cultured with irradiated autologous chondrocytes, and their proliferative response was assessed using 3H-thymidine incorporation. Expression of HLA-class II molecules was also assessed on chondrocytes by immunohistochemistry or flow cytometry. RESULTS T cell responses to autologous chondrocytes in OA yielded a significantly greater mean stimulation index (6.35 +/- 1.63) compared to controls (1.21 +/- 0.09, p < 0.01). This response was partially blocked by antibodies against HLA class I, class II, CD4 or CD8. Increased expression of HLA-DP, -DQ, and -DR was observed. CONCLUSION This study showed the autologous T cell-stimulating property of OA chondrocytes in vitro. The elucidation of the autoimmune responses may contribute to the understanding of immune-mediated mechanisms in OA.
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86
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Sakata M, Fujii M. Synthesis and properties of novel acyclic nucleotides. NUCLEIC ACIDS SYMPOSIUM SERIES 2003:47-8. [PMID: 12903261 DOI: 10.1093/nass/44.1.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Acyclic adenosine and thymidine analogs derived from L- and D-threonie were synthesised and incorporated into oligonucleotides by automated protocols using a standard phosphoramidite method. UV melting experiments with thus obtained oligonucleotides showed that incorporation of those acyclic nucleosides did not destabilize the hybrid duplexes and that the stabilities of them are influenced by the stereochemical structures of acyclic analogs. Modification of 3'-end of oligonucleotide with acyclic analogs protected the oligonucleotide against 3'-exonuclease.
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87
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Endo T, Hotta Y, Haraguchi K, Sakata M. Mercury contamination in the red meat of whales and dolphins marketed for human consumption in Japan. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:2681-2685. [PMID: 12854705 DOI: 10.1021/es034055n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cetacean products sold for human consumption in Japan originate from a wide range of whale, dolphin, and porpoise species caught off several areas of the Japan coast, Antarctic and North Pacific Oceans. We surveyed the total mercury (T-Hg) levels in red meat, the most popular cetacean products in Japan. We also analyzed the DNA of these to obtain information regarding species. According to the genetic analysis, the red meats originating from nine species of odontocete and six species of mystecete were sold in Japanese markets. T-Hg concentrations in all odontocete red meats (0.52-81.0 microg/wet g, n = 137) exceeded the provisional permitted level of T-Hg in marine foods set by the Japanese government (0.4 microg/wet g). The highest and second highest levels of T-Hg in the red meats were found in the false killer whale (81.0 microg/wet g) and striped dolphin (63.4 microg/wet g), respectively. These concentrations of T-Hg exceeded the permitted level of T-Hg by about 200 and 160 times, respectively, suggesting the possibility of chronic intoxication by methyl mercury due to frequent consumption of odontocete red meats. The T-Hg concentration levels were higher in odontocete species such as Baird's beaked whales and pilot whales caught off southern areas than those caught off northern areas, probably reflecting a higher Hg concentration in the seawater and/or their diet (squid and fish) in the southern area. On the other hand, T-Hg concentrations in all mystecete red meat samples except for one (0.01-0.54 microg/ wet g, n = 62) were below the permitted level of T-Hg, probably reflecting their lower trophic levels.
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88
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Takata M, Nishibori E, Sakata M, R-Wang C, Shinohara H. Sc2 dimer in IPR-violated C66 fullerene: a covalent bonded metallofullerene. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00423-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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89
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Matsuno K, Katsufuji T, Mori S, Nohara M, Machida A, Moritomo Y, Kato K, Nishibori E, Takata M, Sakata M, Kitazawa K, Takagi H. Charge ordering and spin frustration in AlV2-x CrxO4. PHYSICAL REVIEW LETTERS 2003; 90:096404. [PMID: 12689246 DOI: 10.1103/physrevlett.90.096404] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2002] [Indexed: 05/24/2023]
Abstract
The relationship between charge and spin degrees of freedom in a geometrically frustrated system, AlV2-xCrxO4 spinel, is investigated. Upon Cr doping, the charge-ordered phase of AlV2O4 is rapidly suppressed and a charge-disordered phase grows up instead. It is found that the magnetic ground state is a spin-glass state dominated by geometrical frustration for both phases, but larger spin entropy remains down to low temperatures in the charge-ordered phase, possibly owing to its two-dimensional character.
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90
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Nishibori E, Takata M, Sakata M, Taninaka A, Shinohara H. Pentagonal-dodecahedral la2 charge density in [80-ih ]fullerene: la2 @c80. Angew Chem Int Ed Engl 2002; 40:2998-9. [PMID: 12203628 DOI: 10.1002/1521-3773(20010817)40:16<2998::aid-anie2998>3.0.co;2-4] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2001] [Indexed: 11/09/2022]
Abstract
A double shell of Platonic solids: A trajectory that connects the six-membered rings of Ih -C80 is followed by the two La atoms of La2 @C80 according to maximum entropy/Rietveld analysis of the synchrotron powder-diffraction data. The result is a pentagonal-dodecahedral charge-density distribution for La2 (brown in the picture) inside the icosahedral C80 cage (green).
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91
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Sakata M, Takata M, Nishibori E. MEM charge density studies for materials with characteristic physical properties. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302095028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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92
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Kato K, Nishibori E, Takata M, Sakata M, Nakano T, Uchihira K, Tsubota M, Iga F, Takabatake T. The metal-insulator transition in Y1−xCaxTiO3caused by structural phase separation. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302090906] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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93
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Sakata M, Sa'do B, Nakata S, Morishita T, Nakasima A. Orthodontic appliances made of organic polymer used in the metal allergic patient can withstand orthognathic surgery. Orthod Craniofac Res 2002; 5:179-84. [PMID: 12194668 DOI: 10.1034/j.1600-0544.2002.01171.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We developed an orthodontic appliance completely made of organic polymer. The appliance was used for many years and proved very effective. It was used for the treatment of patients with metal allergy, and as a result, it is believed to be the best choice for treating metal allergies. In this report, we are presenting a surgical case with Class III malocclusion for a patient with metal allergy, and the concept of the appliance is briefly discussed.
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94
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Hieu Chi D, Iwasa Y, Chen X, Takenobu T, Ito T, Mitani T, Nishibori E, Takata M, Sakata M, Kubozono Y. Bridging fullerenes with metals. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)00297-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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95
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Sakata M, Masuko-Hongo K, Tsuruha J, Sekine T, Nakamura H, Takigawa M, Nishioka K, Kato T. YKL-39, a human cartilage-related protein, induces arthritis in mice. Clin Exp Rheumatol 2002; 20:343-50. [PMID: 12102470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
OBJECTIVE To determine whether YKL-39, a recently cloned secretory protein of articular chondrocytes, is arthritogenic in mice. METHODS Recombinant YKL-39 (rYKL-39) was expressed and purified from E. coli. To induce arthritis in mice, rYKL-39 (1, 10 or 50 g in Freund's incomplete adjuvant) was injected into the right footpad of mice from four different strains (BALB/c, DBA/1J, C57BL/6 and ICR). The mice received a second immunization with rYKL-39 by intradermal injection into the root of the tail 10 days after the first immunization. Severity of arthritis was assessed by scoring each paw on a scale from 0 to 4. Sixty days after thefirst immunization, the mice were sacrificed and the joints were examined by immunohistochemistry and radiography. The anti-YKL-39 and anti type II-collagen (CII) antibody titres were also assayed using ELISA. RESULTS Immunization with YKL-39 induced arthritis in all strains of mice tested, among which BALB/c was most susceptible. Histological examination showed synovial proliferation and irregularity of the cartilage surface in YKL-39-injected BALB/c mice. Moreover radiographic analysis revealed pathological changes in these mice. The YKL-39-immunised mice produced not only anti-YKL-39 antibody but also antibody against type II collagen, suggesting a spreading of autoimmunity after YKL-39. CONCLUSIONS YKL-39, a cartilage-related protein, is found to induce arthritis accompanied by pathologic changes in bone and cartilage. A better understanding of the immune response against cartilage-related components including YKL-39 may help to elucidate the pathological processes of arthritic disorders.
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MESH Headings
- Adipokines
- Animals
- Antibodies/blood
- Antibody Specificity
- Arthritis, Experimental/diagnostic imaging
- Arthritis, Experimental/immunology
- Arthritis, Experimental/pathology
- Cartilage
- Cell Division/drug effects
- Cell Division/immunology
- Chitinase-3-Like Protein 1
- Collagen Type II/immunology
- Disease Models, Animal
- Female
- Gene Expression
- Glycoproteins/genetics
- Glycoproteins/immunology
- Glycoproteins/pharmacology
- Humans
- Injections, Intradermal
- Lectins
- Leukocytes, Mononuclear/cytology
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Inbred ICR
- Radiography
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Recombinant Proteins/pharmacology
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96
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Takeda N, Yokoyama I, Hiroi Y, Sakata M, Harada T, Nakamura F, Murakawa Y, Nagai R. Positron emission tomography predicted recovery of complete A-V nodal dysfunction in a patient with cardiac sarcoidosis. Circulation 2002; 105:1144-5. [PMID: 11877369 DOI: 10.1161/hc0902.103432] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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97
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Morita K, Kuwada A, Sano A, Sakata M, Sei H, Morita Y. Semi-quantitative RT-PCR analysis of environmental influence on P450scc and PNMT mRNA expression in rat adrenal glands. Life Sci 2001; 70:73-80. [PMID: 11764008 DOI: 10.1016/s0024-3205(01)01368-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Environmental influence on brain function, particularly spatial learning and memory, has been extensively investigated, but little is known about the influence of environmental conditions on the functions of peripheral organs. In the present study, the effects of different housing conditions on the steady-state levels of mRNAs encoding cholesterol side-chain cleavage enzyme (cytochrome P450scc) and phenylethanolamine N-methyltransferase (PNMT) in adrenal glands was examined to investigate the environmental influence on both adrenocortical and adrenomedullary functions. Behavioral changes of the animals housed in different conditions were first examined to assess the relevance of environmental manipulation used. In consistent with previous findings, housing of the animals in enriched conditions resulted in the significant reduction of spontaneous motor activity (locomotor activity and rearing) in comparison with housing in isolated conditions, thus indicating the relevance of housing conditions used in this work for investigating the environmental influence on adrenal function. Then, the effects of these housing conditions on P450scc and PNMT mRNA levels in adrenal glands were examined using semi-quantitative RT-PCR method. In comparison with the isolated group, the enriched group showed significantly higher levels of P450scc mRNA. In contrast, PNMT mRNA levels in the enriched group were significantly lower than those in the isolated group. These results propose the possibility that the environmental conditions may cause differential alterations in adrenocortical and adrenomedullary functions, although their possible association with behavioral changes still remains to be elucidated.
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98
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Kuroiwa Y, Aoyagi S, Sawada A, Harada J, Nishibori E, Takata M, Sakata M. Evidence for Pb-O covalency in tetragonal PbTiO3. PHYSICAL REVIEW LETTERS 2001; 87:217601. [PMID: 11736378 DOI: 10.1103/physrevlett.87.217601] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2001] [Indexed: 05/23/2023]
Abstract
Accurate charge-density distributions of cubic and tetragonal PbTiO3 and BaTiO3 have been obtained by the MEM(maximum entropy method)/Rietveld analysis using synchrotron-radiation powder data. The Pb-O bonds in tetragonal PbTiO3 show rather strong covalency, while those in cubic PbTiO3 are ionic. This is the clear evidence of the Pb-O hybridization in tetragonal PbTiO3, which has been theoretically predicted as a key factor of much larger ferroelectricity of this substance than that of BaTiO3. Tetragonal PbTiO3 forms a layered structure of a two-dimensional covalent-bonding network consisting of the Ti-O5 pyramid.
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99
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Okamoto Y, Sakata M, Yamamoto T, Nishio Y, Adachi K, Ogura K, Yamaguchi M, Takeda T, Tasaka K, Murata Y. Involvement of nuclear transcription factor Sp1 in regulating glucose transporter-1 gene expression during rat trophoblast differentiation. Biochem Biophys Res Commun 2001; 288:940-8. [PMID: 11689000 DOI: 10.1006/bbrc.2001.5860] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glucose transporter-1 (GLUT1) is important in placental glucose transport. However, the mechanism of regulation of placental GLUT1 expression remains to be elucidated. We show here that the level of GLUT1 protein in rat choriocarcinoma cells (Rcho-1) decreased during differentiation. To analyze the regulatory mechanism of rat GLUT1 (rGLUT1) gene expression, we transfected rGLUT1 promoter-chloramphenicol acetyltransferase constructs into Rcho-1 cells. Deletion analysis of the rGLUT1 promoter suggested that the region -76/-53 bp was essential for basal transcriptional activity. Electrophoretic mobility shift assays showed that transcription factors Sp1 and Sp3 bound two GC boxes in the region -99/-33 bp of the rGLUT1 promoter. Mutation analysis of the Sp1 binding sites revealed that the promoter-proximal site located between -76 and -53 bp was essential for basal rGLUT1 promoter activity. Furthermore, the decreased level of GLUT1 may result from a decreased level of Sp1 during differentiation. These findings suggest that Sp1 is involved in the regulation of rGLUT1 gene expression during rat trophoblast differentiation.
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100
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Masuko-Hongo K, Sakata M, Yuan GH, Onuma H, Nakamura H, Aoki H, Kato T, Nishioka K. Expression of Fas-associated death domain-like interleukin-1beta-converting enzyme (FLICE) inhibitory protein (FLIP) in human articular chondrocytes: possible contribution to the resistance to Fas-mediated death of in vitro cultured human articular chondrocytes. Rheumatol Int 2001; 21:112-21. [PMID: 11765224 DOI: 10.1007/s00296-001-0144-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although chondrocyte apoptosis has been noted in arthritic joints, the mechanism is not clear. To investigate whether Fas-mediated apoptosis has a role in this process, the presence of Fas mRNA and expression of cell surface Fas protein in monolayer-cultured human articular chondrocytes was analyzed. Fas mRNA was found in all chondrocyte samples analyzed; moreover, the majority of cells in chondrocyte populations expressed cell-surface Fas (12-90%, average 49%). Nevertheless, treatment with an agonistic anti-Fas antibody did not induce significant apoptosis in these chondrocytes in vitro. However, it was also found that chondrocytes express Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (FLIP), a molecule which blocks Fas-mediated apoptosis. Correspondingly, activation of caspase-8 was minimal in these cultured chondrocytes. In conclusion, although human articular chondrocytes do express cell-surface Fas, this receptor did not fully mediate death-inducing signals in vitro. This resistance to Fas may be partly due to the constitutive expression of FLIP.
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