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1.
Mock retroviral infection alters the developmental potential of murine bone marrow stem cells. 总被引:2,自引:0,他引:2
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D Dumenil H Jacquemin-Sablon H Neel E Frindel F Dautry 《Molecular and cellular biology》1989,9(10):4541-4544
Retroviral vectors were used to introduce an activated ras gene into murine pluripotent hemopoietic stem cells. We attempted to reconstitute the hemopoietic system of lethally irradiated mice with isolated spleen colonies obtained in vivo after injection of infected bone marrow cells. Spleen colonies derived from infected bone marrow were inefficient in promoting long-term survival of irradiated hosts. This loss of reconstitutive capacity of spleen colonies was not due to the retroviral infection per se but to the in vitro culture of spleen colony precursors. Incubation for 24 h in the presence of fetal calf serum and interleukin-3 without virus-producing cells was sufficient to abolish completely the reconstitutive capacity of spleen colonies while maintaining both self-renewal and pluripotential capacities of spleen colony precursors. These results show that the in vitro manipulation of stem cells that is included in current protocols for retroviral infection can modify the developmental potential of these cells. This finding clearly indicates that the use of retroviral vectors can introduce a bias in the analysis of hemopoiesis. 相似文献
2.
Carole DG Michel DM Julien C Florence D Anna N Séverine J Gérard D Pierre TD Jean-Pierre G 《Bioorganic & medicinal chemistry》2005,13(19):5560-5568
Newly synthesized 4,5-di-substituted acridines were assessed for in vitro antileishmanial activities as compared to those of their 4-mono-substituted homologues. Mono-substituted acridines exhibited a weak specificity for Leishmania parasites. Di-substituted acridines, on the contrary, displayed interesting amastigote-specific activities through a mechanism of action that might not involve intercalation to DNA. This antileishmanial property, associated with a low antiproliferative activity towards human cells, led to the identification of a new class of promising acridine derivatives such as 4,5-bis(hydroxymethyl)acridine with a nonclassical mechanism of action based on the inhibition of Leishmania internalization within macrophages. In the meantime, the effects of experimental lighting on the biological properties of acridines were assessed: experimental lighting did not significantly improve the antileishmanial activity of the compounds since it produced a greater toxicity against human cells. 相似文献
3.
Richard J. Mills Sean J. Humphrey Patrick R.J. Fortuna Mary Lor Simon R. Foster Gregory A. Quaife-Ryan Rebecca L. Johnston Troy Dumenil Cameron Bishop Rajeev Rudraraju Daniel J. Rawle Thuy Le Wei Zhao Leo Lee Charley Mackenzie-Kludas Neda R. Mehdiabadi Christopher Halliday Dean Gilham James E. Hudson 《Cell》2021,184(8):2167-2182.e22
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4.
VLJ Whitehall TD Dumenil DM McKeone CE Bond ML Bettington RL Buttenshaw L Bowdler GW Montgomery LF Wockner BA Leggett 《Epigenetics》2014,9(11):1454-1460
The CpG Island Methylator Phenotype (CIMP) is fundamental to an important subset of colorectal cancer; however, its cause is unknown. CIMP is associated with microsatellite instability but is also found in BRAF mutant microsatellite stable cancers that are associated with poor prognosis. The isocitrate dehydrogenase 1 (IDH1) gene causes CIMP in glioma due to an activating mutation that produces the 2-hydroxyglutarate oncometabolite. We therefore examined IDH1 alteration as a potential cause of CIMP in colorectal cancer. The IDH1 mutational hotspot was screened in 86 CIMP-positive and 80 CIMP-negative cancers. The entire coding sequence was examined in 81 CIMP-positive colorectal cancers. Forty-seven cancers varying by CIMP-status and IDH1 mutation status were examined using Illumina 450K DNA methylation microarrays. The R132C IDH1 mutation was detected in 4/166 cancers. All IDH1 mutations were in CIMP cancers that were BRAF mutant and microsatellite stable (4/45, 8.9%). Unsupervised hierarchical cluster analysis identified an IDH1 mutation-like methylation signature in approximately half of the CIMP-positive cancers. IDH1 mutation appears to cause CIMP in a small proportion of BRAF mutant, microsatellite stable colorectal cancers. This study provides a precedent that a single gene mutation may cause CIMP in colorectal cancer, and that this will be associated with a specific epigenetic signature and clinicopathological features. 相似文献
5.
Odors are notoriously difficult to describe, but they seem prone to a variety of crossmodal associations. In the present study, we generalize the previously-shown association between odors (from perfumery) and pitch (Belkin et al. 1997) to odors related to food and drink (in this case those associated with wine). We also demonstrate that, to a lesser extent (25% of the odor tested), participants preferentially match specific odors to certain types of instruments. The ratings of the odors along a number of dimensions are used in principal components analysis (PCA) to explore the psychological dimensions underlying the odor-pitch associations. The results demonstrate that both pleasantness and complexity, but not intensity, appear to play a role when choosing a pitch to match an odor. Our results suggest that these features of odor stimuli constitute psychological dimensions that can be consistently matched to auditory features. 相似文献
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7.
Several compounds such as a methylhopanoid and carotenoids have been isolated and characterized from a facultative methylotrophicCorynebacterium sp., a vitamin B12 producer. A novel pentacyclic triterpene, 2-methyl-22-hydroxyhopane has been identified by IR,1H-and13C-NMK and mass spectrometry. During the purification procedure a red pigment has been characterized as a mixture of several
carotenoids by TLC and UV-VIS spectroscopy. 相似文献
8.
Summary A fed-batch culture of methanol-utilizing microorganism (Corynebacterium sp. XG), a vitamin B 12 producer, was carried out with constant feed of substrate. Experimental results agreed with the theorical model proposed in the literature. Using this feeding system, the final biomass and vitamin B 12 concentration reached 16.3 g/l and 880 g/l respectively after a 53 h incubation period at 30 °C. 相似文献
9.
Murine pluripotent hematopoietic progenitors constitutively expressing a normal erythropoietin receptor proliferate in response to erythropoietin without preferential erythroid cell differentiation. 总被引:6,自引:0,他引:6
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A Dubart F Feger C Lacout F Goncalves W Vainchenker D Dumenil 《Molecular and cellular biology》1994,14(7):4834-4842
Erythropoietin (EPO) is a prime regulator of the growth and differentiation of erythroid blood cells. The EPO receptor (EPO-R) is expressed in late erythroid progenitors (mature BFU-E and CFU-E), and EPO induces proliferation and differentiation of these cells. By introducing, with a retroviral vector, a normal EPO-R cDNA into murine adult bone marrow cells, we showed that EPO is also able to induce proliferation in pluripotent progenitor cells. After 7 days of coculture with virus-producing cells, bone marrow cells were plated in methylcellulose culture in the presence of EPO, interleukin-3, or Steel factor alone or in combination. In the presence of EPO alone, EPO-R virus-infected bone marrow cells gave rise to mixed colonies comprising erythrocytes, granulocytes, macrophages and megakaryocytes. The addition of interleukin-3 or Steel factor to methylcellulose cultures containing EPO did not significantly modify the number of mixed colonies. The cells which generate these mixed colonies have a high proliferative potential as shown by the size and the ability of the mixed colonies to give rise to secondary colonies. Thus, it appears that EPO has the same effect on EPO-R-expressing multipotent cell proliferation as would a combination of several growth factors. Finally, our results demonstrate that inducing pluripotent progenitor cells to proliferate via the EPO signaling pathway has no major influence on their commitment. 相似文献
10.
Fran?ois Philippart Ga?lle Bouroche Jean-Fran?ois Timsit Maité Garrouste-Orgeas Elie Azoulay Michael Darmon Christophe Adrie Bernard Allaouchiche Claire Ara-Somohano Stéphane Ruckly Anne-Sylvie Dumenil Bertrand Souweine Dany Goldgran-Toledano Lila Bouadma Beno?t Misset Outcomerea study group 《PloS one》2015,10(9)