91 research outputs found

    Therapy for pneumonitis and sialadenitis by accumulation of CCR2-expressing CD4(+)CD25(+ )regulatory T cells in MRL/lpr mice

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    Adoptive transfer of CD4(+)CD25(+ )regulatory T cells has been shown to have therapeutic effects in animal models of autoimmune diseases. Chemokines play an important role in the development of autoimmune diseases in animal models and humans. The present study was performed to investigate whether the progression of organ-specific autoimmune diseases could be reduced more markedly by accumulating chemokine receptor-expressing CD4(+)CD25(+ )regulatory T cells efficiently in target organs in MRL/MpJ-lpr/lpr (MRL/lpr) mice. CD4(+)CD25(+)Foxp3(+ )T cells (Treg cells) and CD4(+)CD25(+)Foxp3(+ )CCR2-transfected T cells (CCR2-Treg cells) were transferred via retro-orbital injection into 12-week-old MRL/lpr mice at the early stage of pneumonitis and sialadenitis, and the pathological changes were evaluated. Expression of monocyte chemoattractant protein-1 (MCP-1)/CCL2 was observed in the lung and submandibular gland of the mice and increased age-dependently. The level of CCR2 expression and MCP-1 chemotactic activity of CCR2-Treg cells were much higher than those of Treg cells. MRL/lpr mice to which CCR2-Treg cells had been transferred showed significantly reduced progression of pneumonitis and sialadenitis in comparison with MRL/lpr mice that had received Treg cells. This was due to more pronounced migration of CCR2-Treg cells and their localization for a longer time in MCP-1-expressing lung and submandibular gland, resulting in stronger suppressive activity. We prepared chemokine receptor-expressing Treg cells and demonstrated their ability to ameliorate disease progression by accumulating in target organs. This method may provide a new therapeutic approach for organ-specific autoimmune diseases in which the target antigens remain undefined

    Examination of HeLa cell contamination of human cell lines derived from primary hepatomas using glucose-6-phosphate dehydrogenase and lactate dehydrogenase isozymes.

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    Isozyme patterns of glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) in human cell lines derived from primary hepatomas were compared with those in HeLa cells. Some cell lines derived from primary hepatomas having type B G6PD showed one or two isozymes of LDH. On the other hand, HeLa cells having type A G6PD showed four LDH isozymes. These findings suggest that not only G6PD, but also LDH may be useful for the detection of HeLa cell contamination of a culture in some cases.</p

    Effect of various factors and substrates on the growth of a human hepatoblastoma cell line, HuH-6 in a serum-free medium.

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    The effect of various factors and substrates on the growth of a human hepatoblastoma cell line, HuH-6, which was inoculated at low density in a serum-free medium was examined. Several supplements were required to enhance cell growth of HuH-6. These included cholera toxin (CT), glucagon (Glu) and selenium (Se). Type IV collagen (C-IV) provided the most conductive environment tested for cell growth. These results suggest that CT, Glu, Se, and C-IV are important stimulators for the continuous growth of HuH-6 in a serum-free medium at low density.</p

    CO Multi-line Imaging of Nearby Galaxies (COMING). IX. 12^{12}CO(JJ=2-1)/12^{12}CO(JJ=1-0) line ratio on kiloparsec scales

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    While molecular gas mass is usually derived from 12^{12}CO(JJ=1-0) - the most fundamental line to explore molecular gas - it is often derived from 12^{12}CO(JJ=2-1) assuming a constant 12^{12}CO(JJ=2-1)/12^{12}CO(JJ=1-0) line ratio (R2/1R_{2/1}). We present variations of R2/1R_{2/1} and effects of the assumption that R2/1R_{2/1} is a constant in 24 nearby galaxies using 12^{12}CO data obtained with the Nobeyama 45-m radio telescope and IRAM 30-m telescope. The median of R2/1R_{2/1} for all galaxies is 0.61, and the weighted mean of R2/1R_{2/1} by 12^{12}CO(JJ=1-0) integrated-intensity is 0.66 with a standard deviation of 0.19. The radial variation of R2/1R_{2/1} shows that it is high (~0.8) in the inner ~1 kpc while its median in disks is nearly constant at 0.60 when all galaxies are compiled. In the case that the constant R2/1R_{2/1} of 0.7 is adopted, we found that the total molecular gas mass derived from 12^{12}CO(JJ=2-1) is underestimated/overestimated by ~20%, and at most by 35%. The scatter of a molecular gas surface density within each galaxy becomes larger by ~30%, and at most by 120%. Indices of the spatially resolved Kennicutt-Schmidt relation by 12^{12}CO(JJ=2-1) are underestimated by 10-20%, at most 39% in 17 out of 24 galaxies. R2/1R_{2/1} has good positive correlations with star-formation rate and infrared color, and a negative correlation with molecular gas depletion time. There is a clear tendency of increasing R2/1R_{2/1} with increasing kinetic temperature (TkinT_{\rm kin}). Further, we found that not only TkinT_{\rm kin} but also pressure of molecular gas is important to understand variations of R2/1R_{2/1}. Special considerations should be made when discussing molecular gas mass and molecular gas properties inferred from 12^{12}CO(JJ=2-1) instead of 12^{12}CO(JJ=1-0).Comment: 29 pages, 18 figures, 5 tables. Accepted for publication in PASJ. The original resolution version is available here (https://astro3.sci.hokudai.ac.jp/~radio/coming/publications/COMING_IX_org_res.pdf

    CO Multi-line Imaging of Nearby Galaxies (COMING). III. Dynamical effect on molecular gas density and star formation in the barred spiral galaxy NGC 4303

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    We present the results of 12^{12}CO(JJ=1-0) and 13^{13}CO(JJ=1-0) simultaneous mappings toward the nearby barred spiral galaxy NGC 4303 as a part of the CO Multi-line Imaging of Nearby Galaxies (COMING) project. Barred spiral galaxies often show lower star-formation efficiency (SFE) in their bar region compared to the spiral arms. In this paper, we examine the relation between the SFEs and the volume densities of molecular gas n(H2)n(\rm{H}_2) in the eight different regions within the galactic disk with CO data combined with archival far-ultraviolet and 24 μ\mum data. We confirmed that SFE in the bar region is lower by 39% than that in the spiral arms. Moreover, velocity-alignment stacking analysis was performed for the spectra in the individual regions. The integrated intensity ratios of 12^{12}CO to 13^{13}CO (R12/13R_{12/13}) range from 10 to 17 as the results of stacking. Fixing a kinetic temperature of molecular gas, n(H2)n(\rm{H}_2) was derived from R12/13R_{12/13} via non-local thermodynamic equilibrium (non-LTE) analysis. The density n(H2)n(\rm{H}_2) in the bar is lower by 31-37% than that in the arms and there is a rather tight positive correlation between SFEs and n(H2)n(\rm{H}_2), with a correlation coefficient of 0.8\sim 0.8. Furthermore, we found a dependence of n(H2)n(\rm{H}_2) on the velocity dispersion of inter-molecular clouds (ΔV/sini\Delta V/ \sin i). Specifically, n(H2)n(\rm{H}_2) increases as ΔV/sini\Delta V/ \sin i increases when ΔV/sini<100\Delta V/ \sin i < 100 km s1^{-1}. On the other hand, n(H2)n(\rm{H}_2) decreases as ΔV/sini\Delta V/ \sin i increases when ΔV/sini>100\Delta V/ \sin i > 100 km s1^{-1}. These relations indicate that the variations of SFE could be caused by the volume densities of molecular gas, and the volume densities could be governed by the dynamical influence such as cloud-cloud collisions, shear and enhanced inner-cloud turbulence.Comment: 15 pages, 8 figures, accepted for publication in PAS
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