58 research outputs found
Structural determinants of salmon calcitonin bioactivity -the role of the leu-based amphipatic alfa-helix
No full textSalmon calcitonin (sCT) forms an amphipathic helix in the region 9-19, with the C-terminal decapeptide interacting with the helix (Amodeo, P., Motta, A., Strazzullo, G., Castiglione Morelli, M. A. (1999) J. Biomol. NMR 13, 161-174). To uncover the structural requirements for the hormone bioactivity, we investigated several sCT analogs. They were designed so as to alter the length of the central helix by removal and/or replacement of flanking residues and by selectively mutating or deleting residues inside the helix. The helix content was assessed by circular dichroism and NMR spectroscopies; the receptor binding affinity in human breast cancer cell line T 47D and the in vivo hypocalcemic activity were also evaluated. In particular, by NMR spectroscopy and molecular dynamics calculations we studied Leu(23),Ala(24)-sCT in which Pro(23) and Arg(24) were replaced by helix inducing residues. Compared with sCT, it assumes a longer amphipathic alpha-helix, with decreased binding affinity and one-fifth of the hypocalcemic activity, therefore supporting the idea of a relationship between a definite helix length and bioactivity. From the analysis of other sCT mutants, we inferred that the correct helix length is located in the 9-19 region and requires long range interactions and the presence of specific regions of residues within the sequence for high binding affinity and hypocalcemic activity. Taken together, the structural and biological data identify well defined structural parameters of the helix for sCT bioactivity
Comparative anatomical study of retinal ganglion cell topography in predatory birds
No full text原著論文
Nishimira, H., Nakamuta, N., Yamamoto, Y.
Adaptive features of the eye to the ecological habit of the Short-eared Owl Asio flammeus and Japanese-scops Owl Otus semitorques
Ornithological Science 22(1), 35-44, 202
Human periapical granulation tissue contains osteogenic cells
No full textThe original publication can be found at www.springerlink.comBone defects caused by periapical inflammation can be treated and improved by endodontic therapy. However, the mechanism for osseous healing of periapical lesions after root canal treatment is unclear. In this study we examined whether fibroblastic cells from human periapical granulation tissue could produce calcified matrix in vitro. Periapical lesions from three patients were dissected in endodontic surgery, and fibroblastic cells (HFC) migrating from these lesions in vitro were used in this study. The HFC were cultured with or without beta-glycerophosphate (β-GP) and ascorbic acid (AA), and the expression of human runt-related transcription factor-2 (Runx2), osterix (Osx), osteopontin (Opn), and osteocalcin (Ocn) mRNA, and alkaline phosphatase (ALPase) was examined by reverse transcriptase-polymerase chain reaction (RT-PCR) or by an enzyme-cytochemical technique. Furthermore, calcification in the cells was investigated by von Kossa staining. At the beginning of the culture, HFC expressed Runx2 mRNA faintly, but neither Opn mRNA nor ALPase activity. Immunocytochemical study also showed HFC expressed Runx2 more weakly, compared to SaOS2. However, the expression levels of ALPase, and Runx2, Osx, and Opn mRNA, were stimulated by 2 mM β-GP and 50 μg/ml AA. After 4 weeks of culture with 2 mM β-GP and 50 μg/ml AA, HFC formed von Kossa staining-positive calcified deposits on culture dishes, and also expressed Ocn mRNA. These results suggest that inflamed periapical granulation tissue contains osteogenic cells that have the potential to differentiate into mature osteoblastic or cementoblastic cells, and that such cells might contribute to osseous healing after root canal treatment.Hidefumi Maeda, Naohisa Wada, Hiroyoshi Nakamuta and Akifumi Akamin
猛禽類における視神経節細胞の分布に関する比較解剖学的研究
No full text岩手大学博士（獣医学）原著論文
Nishimira, H., Nakamuta, N., Yamamoto, Y.
Adaptive features of the eye to the ecological habit of the Short-eared Owl Asio flammeus and Japanese-scops Owl Otus semitorques
Ornithological Science 22(1), 35-44, 2023doctoral thesi
Cell therapy for ischemic cardiac disease: effect of different routes for cell administration, time post-mi and the use of a fibrin polymer for cardiac cell retention and myocardial function
No full textA terapia celular representa uma abordagem promissora para o tratamento de cardiopatia isquêmica, porém aspectos-chave dessa estratégia permanecem incertos. Neste trabalho avaliamos a eficiência da retenção cardíaca de células da medula óssea marcadas com tecnécio (99m Tc-CMO) transplantadas, de acordo com o tempo após o infarto (1, 2, 3 e 7 dias) e a via de administração dessas células (intravenosa [IV], intraventricular [IC], intracoronariana [ICO] e intramiocárdica [IM]), em ratos submetidos à isquemia-reperfusão cardíaca [I&R]. Após 24 horas, a retenção cardíaca de 99m Tc-CMO foi maior na via IM comparada com a média alcançada pelas demais (6,79% do total injetado vs. 0,53%). O uso de fibrina como veículo para a injeção de células incrementou a retenção em 2.5 vezes (17,12 vs. 6,84%) na via IM. Curiosamente, quando administradas após 7 dias, a retenção de células na via IM alcançou valores próximos dos observados com da matriz de fibrina injetadas 24 h após a I&R (16,55 vs. 17,12%), enquanto que para as demais vias as mudanças foram insignificantes. Nos animais em que as CMO foram administradas por via intramiocárdica 24 horas após a I&R, com ou sem fibrina, observou-se melhora significante do desempenho cardíaco frente ao estresse farmacológico com fenilefrina quando comparados aos controles. Em conjunto, os dados mostram a biodistribuição das células injetadas após a I&R por 4 diferentes vias e 4 intervalos de tempo pós-lesão e indicam que a via IM é a que produz maior retenção cardíaca. O uso do biopolímero de fibrina aumenta a retenção das células e a eficácia deste efeito sobre a função cardíaca e mortalidade dos animais em longo prazo, além de 30 dias pós I&R, merecerá ser investigada no futuro.Cell therapy represents a promising approach for ischemic cardiac disease, but key aspects of this strategy remain unclear. We examined the effects of timing and route of administration of bone marrow cells (BMCs) after myocardial ischemia/reperfusion injury (I&R). 99mTc-labeled BMCs were injected by 4 different routes: intravenous (IV), left ventricular cavity (LV), left ventricular cavity with temporal aorta occlusion (LV+) and intramyocardial (IM). The injections were performed 1, 2, 3, or 7 days after infarction. Cardiac retention was higher following the IM route compared to the average values obtained by all other routes (6.79% of the total radioactivity injected vs. 0.53%). Use of a fibrin biopolymer as vehicle during IM injection led to a 2.5-fold increase in cardiac cell accumulation (17.12 vs. 6.84%). Interestingly, the retention of cells administered with culture medium at day 7 post-MI by the IM route was similar to that observed when cells were injected 24 h post-IM using fibrin (16.55 vs 17.12%), whereas no significant changes were observed for the other routes. Cell therapy 24 hs post MI by IM injection, with or without fibrin, resulted in comparable improvement in cardiac function under pharmacological stress compared to control animals. Together, we provide evidence for the biodistribution of 99mTc-labeled BMCs injected post MI by 4 different routes and times post-injury, which shows that the IM rout is the most effective for cardiac cell retention. The use of a fibrin biopolymer further increased cardiac cell retention and its potential long term benefits, beyond 30, on reducing mortality and improving cardiac function deserve to be explored in the future
Peak metamorphic temperatures in type 6 ordinary chondrites: An evaluation of pyroxene and plagioclase geothermometry
No full textQuantifying the peak temperatures achieved during metamorphism is critical for understanding the thermal histories of ordinary chondrite parent bodies. Various geothermometers have been used to estimate equilibration temperatures for chondrites of the highest metamorphic grade (type 6), but results are inconsistent and span hundreds of degrees. Because different geothermometers and calibration models were used with different meteorites, it is unclear whether variations in peak temperatures represent actual ranges of metamorphic conditions within type 6 chondrites or differences in model calibrations. We addressed this problem by performing twopyroxene geothermometry, using QUILF95, on the same type 6 chondrites for which peak temperatures were estimated using the plagioclase geothermometer (Nakamuta and Motomura 1999). We also calculated temperatures for published pyroxene analyses from other type 6 H, L, and LL chondrites to determine the most representative peak metamorphic temperatures for ordinary chondrites. Pyroxenes record a narrow, overlapping range of temperatures in H6 (865-926 C), L6 (812-934 C), and LL6 (874-945 C) chondrites. Plagioclase temperature estimates are 96-179 C lower than pyroxenes in the same type 6 meteorites. Plagioclase estimates may not reflect peak metamorphic temperatures because chondrule glass probably recrystallized to plagioclase prior to reaching the metamorphic peak. The average temperature for H, L, and LL chondrites (~900 C), which agrees with previously published oxygen isotope geothermometry, is at least 50 C lower than the peak temperatures used in current asteroid thermal evolution models. This difference may require minor adjustments to thermal model calculations
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Peak metamorphic temperatures in type 6 ordinary chondrites: An evaluation of pyroxene and plagioclase geothermometry
No full textQuantifying the peak temperatures achieved during metamorphism is critical for understanding the thermal histories of ordinary chondrite parent bodies. Various geothermometers have been used to estimate equilibration temperatures for chondrites of the highest metamorphic grade (type 6), but results are inconsistent and span hundreds of degrees. Because different geothermometers and calibration models were used with different meteorites, it is unclear whether variations in peak temperatures represent actual ranges of metamorphic conditions within type 6 chondrites or differences in model calibrations. We addressed this problem by performing twopyroxene geothermometry, using QUILF95, on the same type 6 chondrites for which peak temperatures were estimated using the plagioclase geothermometer (Nakamuta and Motomura 1999). We also calculated temperatures for published pyroxene analyses from other type 6 H, L, and LL chondrites to determine the most representative peak metamorphic temperatures for ordinary chondrites. Pyroxenes record a narrow, overlapping range of temperatures in H6 (865-926 degrees C), L6 (812-934 degrees C), and LL6 (874-945 degrees C) chondrites. Plagioclase temperature estimates are 96-179 degrees C lower than pyroxenes in the same type 6 meteorites. Plagioclase estimates may not reflect peak metamorphic temperatures because chondrule glass probably recrystallized to plagioclase prior to reaching the metamorphic peak. The average temperature for H, L, and LL chondrites (~900 degrees C), which agrees with previously published oxygen isotope geothermometry, is at least 50 degrees C lower than the peak temperatures used in current asteroid thermal evolution models. This difference may require minor adjustments to thermal model calculations.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
Inverted metamorphism in the Pre-Siwalik foreland basin sediments beneath the crystalline nappe, western Nepal Himalaya
No full textLipophilic statins can be osteogenic by promoting osteoblastic calcification in a Cbfa1- and BMP-2-independent manner
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