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391.
SV40 T antigen and telomerase are required to obtain immortalized human adult bone cells without loss of the differentiated phenotype. 总被引:2,自引:0,他引:2
Christian Darimont Ornella Avanti Yvonne Tromvoukis Patricia Vautravers-Leone Nori Kurihara G David Roodman Lorel M Colgin Heide Tullberg-Reinert Andrea M A Pfeifer Elizabeth A Offord Katherine Mace 《Cell growth & differentiation》2002,13(2):59-67
In most human primary bone cells, SV40 T-antigen expression was able to expand life span for a few passages before cells undergo growth arrest, described as crisis. In this study, telomerase activity was reconstituted in human osteoblast precursors (hPOB cells) and marrow stromal cells (Saka cells) transformed with the SV40 T antigen. Bone cells with telomerase activity were able to bypass crisis and show unlimited life span. Despite chromosomal aberrations observed in hPOB-tert cells, these immortalized precursors were able to differentiate into osteoblasts like precrisis hPOB cells. Saka-tert cells enhanced the formation of human osteoclast-like cells in a similar manner as Saka cells. These results demonstrate that reconstitution of telomerase activity in transformed SV40 T-antigen human osteoblast precursors or marrow stromal cells leads to the generation of immortalized cells with a preserved phenotype. 相似文献
392.
P Lissoni O Marelli R Mauri M Resentini P Franco D Esposti G Esposti F Fraschini F Halberg R B Sothern 《Chronobiologia》1986,13(4):339-343
The effect of melatonin injection evaluated earlier with respect to placebo-treated controls is reevaluated, also with reference to spontaneous changes in natural killer cell activity. This effect consists, first, of stimulation of natural killer cell activity over and above any changes brought about by placebo (saline). After 6 h, the melatonin effect appears to be an inhibition as compared to values from placebo-treated subjects, or no effect as compared to values from untreated subjects. In this case, amplification and attenuation of the placebo effect by melatonin are found within the relatively short span of 1/4 of a day, rather than within a day or a week. An ultradian 'feed-sideward' by melatonin may be aligned with the corresponding previously reported circadian and infradian chronomodulation. 相似文献
393.
Current studies on the origin of language clearly show the necessity to go beyond the debate of nature vs. culture in order to pursue an interdisciplinary perspective. The convergence of researches carried out in different fields – neurobiology, palaeoanthropology and linguistics – outlines in a rather clear and convincing framework the strong link between language and motility. Various sources of evidence demonstrate how the mechanisms of culture acquisition and transmission – imitation, language and dexterity – refer back to the same cerebral structures. Moreover, both the motor and the linguistic systems show an identical multileveled basic structure that allows humans high levels of expressiveness. Actions such as the production of tools or the throwing of objects, connected to the very first human behaviours, emerge through space-time concatenations related to the linguistic logic. The hypothesis of a coevolution of language and motor patterns and of a very remote origin of verbal communication is thus debated. 相似文献
394.
We describe a method of two-color immunofluorescence staining which allows the simultaneous analysis of both cytoplasmic antigens and cell entry into the S/G2/M cell cycle phases. This analysis was performed on CD3(-)-activated thymocytes obtained from either highly purified CD1-CD3-CD4-CD8- cells or fresh thymus cell suspensions, stimulated with low doses of phorbol-12 myristate-13 acetate (0.5 ng/ml) and interleukin-2. On the 14th day under these culture conditions about 90% of thymocytes did not express CD3 antigen on the cell surface. CD3- cells were further purified by cell sorting, fixed in paraformaldehyde, and permeabilized with Nonidet-P40. Then these thymocytes were stained by indirect immunofluorescence with monoclonal antibodies identifying T cell-specific molecules (CD3, CD2, CD28, TCR alpha/beta, and TCR gamma/delta) and analyzed for DNA content. Interestingly, both CD3 and CD28 antigens were detectable in the cytoplasm of most cells (greater than 80%). Further, the majority of the thymocytes which had entered the S/G2/M phases of the cell cycle (20%) expressed intracellular CD3 and CD28 molecules and reacted with the anti-beta framework beta F1 monoclonal antibody. The relationship between the appearance of CD3 and other T cell markers in the cytoplasm, the cell cycle entry, and the thymocyte development is discussed. 相似文献
395.
An urgent current need in regenerative medicine is that of identifying a plentiful, safe and ethically acceptable stem cell
source for the development of therapeutic strategies to restore functionality in damaged or diseased organs and tissues. In
this context, human term placenta represents a prime candidate, as it is available in nearly unlimited supply, is ethically
problem-free and easily procured. Placental cells display differentiation capacity toward all three germ layers, while also
displaying immunomodulatory effects, therefore supporting the possibility that they could be applied in an allogeneic transplantation
setting. Although promising data have been reported to date, further study is required to fully characterize the differentiation
potential of placenta-derived cells and to identify their possible clinical applications. Here, we provide a snapshot of current
knowledge regarding the potential of cells from the amniotic membrane of human term placenta to address current shortcomings
in the field of regenerative medicine. 相似文献
396.
Michael S. Christodoulou Nikolas Fokialakis Daniele Passarella Aída Nelly García-Argáez Ornella Maria Gia Ingemar Pongratz Lisa Dalla Via Serkos A. Haroutounian 《Bioorganic & medicinal chemistry》2013,21(14):4120-4131
A collection of compounds, structurally related to the anticancer drug tamoxifen, used in breast cancer therapy, were designed and synthesized as potential anticancer agents. McMurry coupling reaction was used as the key synthetic step in the preparation of these analogues and the structural assignment of E, Z isomers was determined on the basis of 2D-NOESY experiments. The compounds were evaluated for their antiproliferative activity on breast cancer (MCF-7), cervix adenocarcinoma (HeLa) and biphasic mesothelioma (MSTO-211H) human tumor cell lines. The estrogen like properties of the novel compounds were compared with those of the untreated controls using an estrogen responsive element-based (ERE) luciferase reporter assay and compared to 17β-estradiol (E2). Finally, with the aim to correlate the antiproliferative activity with an intracellular target(s), the effect on relaxation activity of DNA topoisomerases I and II was assayed. 相似文献
397.
1,2-Dimethyl-3-pyrrolidone is an important intermediate in the synthesis of cycloalkylaminonaphthalenic analgesics. The optical resolution of this compound with L- and D-tartaric acids is described and the behaviour of the diastereomeric tartrates and of the enantiomers in solution was investigated by NMR spectroscopy and polarimetric analysis. Tautomeric equilibria involving C4 and C2 atoms, which are responsible for the instability of the compound, are demonstrated. Theoretical studies of conformational analysis were also made in order to define the relationships between the stability of the conformers of 1,2-dimethyl-3-pyrrolidone and its structural features. © 1995 Wiley-Liss, Inc. 相似文献
398.
S Cinti M Marelli S Amati F Osculati 《Bollettino della Società italiana di biologia sperimentale》1979,55(1):1-6
Our research is about the ultrastructural aspects of Paneth cells obtained from human jejunal mucosa. The cells appear columnar in shape and show a roundish nucleus; their cytoplasm is characterized by a great amount of R.E.R. and by typical large granules in sopranuclear position. Our results confirm those previously described by other authors about the morphology of Paneth cells. In our specimens we have found moreover a variable number of particular cytoplasmic structures; these may show a fibrillar or granular matrix and are always surrounded by a membrane. 相似文献
399.
Siro Passi Ornella De Pità Pietro Puddu Gian Paolo Littarru 《Free radical research》2013,47(4):471-477
Skin surface lipids (SSL), a very complex mixture of sebum mixed to small amounts of epidermal lipids, mantle the human epidermis, thus representing the outermost protection of the body against exogenous oxidative insults. The present work is a systematic and quantitative analysis of upper-chest SSL and their content in antioxidants in 100 healthy volunteers, divided into five age groups using TLC, HPLC, and GC-MS methods. Further, the effect of exposing SSL in vitro to increasing doses of UV irradiation was examined. Straight monounsaturated and diunsaturated as well as branched monounsaturated fatty acids of triglycerides and pooled fractions were found to be higher at maturity than in childhood and in advancing age. Diunsaturated fatty acids were below 3% of the total and constituted exclusively of C18:2 j 5,8 , C20:2 j 7,10 , C18:2 j 9,12 . Squalene, vitamin E (vit. E) and Coenzyme Q 10 (CoQ 10 ) were found to increase from childhood to maturity to decrease again significantly in old age. Vitamin E and CoQ 10 were the only known lipophilic antioxidants present in SSL. In spite of their low levels they were found to synergically inhibit the UV induced depletion of squalene, cholesterol and of unsaturated fatty acids of SSL. In fact, exposure of SSL to increasing amounts of UV irradiation led preferentially to lowering of the levels of vit. E and CoQ 10 . Four minimal erythema dose (MED) (5.6 J/cm 2 ) were able to deplete 84% vit. E and 70% ubiquinone, and only 13% squalene. Diunsaturated and monounsaturated fatty acids as well as cholesterol were unaffected even following 10 MED UV exposures, which produced a 26% loss of squalene. The same UV dose when applied in the absence of vit. E and CoQ 10 produced a 90% decrease of squalene. 相似文献
400.
G Benedettini G De Libero L Mori P Marelli M R Angioni M Campa 《Cellular immunology》1985,93(2):508-519
Staphylococcus aureus strain Cowan I, a strong polyclonal B-cell activator (PBA), inhibited contact sensitivity to oxazolone in mice when administered 24 hr before sensitization. This suppression was mediated by idiotype-positive (Id+) B lymphocytes, which arose very early during the sensitization process and induced anti-Id B cells. These cells were found at Day 3 of the sensitization process and exerted their effect by activating antigen-specific suppressor T lymphocytes, which affected the efferent phase of the immune response. S. aureus strain Wood 46, which lacks of the ability to act as a PBA, was unable to inhibit contact sensitivity. These results indicate that PBA may play an important role in the regulation of cell-mediated immune reactions. 相似文献