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101.
Skeletal muscle repair by adult human mesenchymal stem cells from synovial membrane 总被引:20,自引:0,他引:20 下载免费PDF全文
De Bari C Dell'Accio F Vandenabeele F Vermeesch JR Raymackers JM Luyten FP 《The Journal of cell biology》2003,160(6):909-918
We have demonstrated previously that adult human synovial membrane-derived mesenchymal stem cells (hSM-MSCs) have myogenic potential in vitro (De Bari, C., F. Dell'Accio, P. Tylzanowski, and F.P. Luyten. 2001. Arthritis Rheum. 44:1928-1942). In the present study, we have characterized their myogenic differentiation in a nude mouse model of skeletal muscle regeneration and provide proof of principle of their potential use for muscle repair in the mdx mouse model of Duchenne muscular dystrophy. When implanted into regenerating nude mouse muscle, hSM-MSCs contributed to myofibers and to long term persisting functional satellite cells. No nuclear fusion hybrids were observed between donor human cells and host mouse muscle cells. Myogenic differentiation proceeded through a molecular cascade resembling embryonic muscle development. Differentiation was sensitive to environmental cues, since hSM-MSCs injected into the bloodstream engrafted in several tissues, but acquired the muscle phenotype only within skeletal muscle. When administered into dystrophic muscles of immunosuppressed mdx mice, hSM-MSCs restored sarcolemmal expression of dystrophin, reduced central nucleation, and rescued the expression of mouse mechano growth factor. 相似文献
102.
Study design
Retrospective study.Objective
To evaluate the radiological results of fusion with segmental pedicle screw fixation in juvenile idiopathic scoliosis with a minimum 5-year follow-up.Summary of background data
Progression of spinal deformity after posterior instrumentation and fusion in immature patients has been reported by several authors. Segmental pedicle screw fixation has been shown to be effective in controlling both coronal and sagittal plane deformities. However, there is no long term study of fusion with segmental pedicle screw fixation in these group of patients.Methods
Seven patients with juvenile idiopathic scoliosis treated by segmental pedicle screw fixation and fusion were analyzed. The average age of the patients was 7.4 years (range 5–9 years) at the time of the operation. All the patients were followed up 5 years or more (range 5–8 years) and were all Risser V at the most recent follow up. Three dimensional reconstruction of the radiographs was obtained and 3DStudio Max software was used for combining, evaluating and modifying the technical data derived from both 2d and 3d scan data.Results
The preoperative thoracic curve of 56 ± 15° was corrected to 24 ± 17° (57% correction) at the latest follow-up. The lumbar curve of 43 ± 14° was corrected to 23 ± 6° (46% correction) at the latest follow-up. The preoperative thoracic kyphosis of 37 ± 13° and the lumbar lordosis of 33 ± 13° were changed to 27 ± 13° and 42 ± 21°, respectively at the latest follow-up. None of the patients showed coronal decompensation at the latest follow-up. Four patients had no evidence of crankshaft phenomenon. In two patients slight increase in Cobb angle at the instrumented segments with a significant increase in AVR suggesting crankshaft phenomenon was seen. One patient had a curve increase in both instrumented and non instrumented segments due to incorrect strategy.Conclusion
In juvenile idiopathic curves of Risser 0 patients with open triradiate cartilages, routine combined anterior fusion to prevent crankshaft may not be warranted by posterior segmental pedicle screw instrumentation. 相似文献103.
Magali Lucia Jean-Marc Andre Patrice Gonzalez Magalie Baudrimont Karine Gontier Regine Maury-Brachet Stephane Davail 《Biometals》2009,22(5):843-853
The impact on palmiped Cairina moschata of two levels of dietary cadmium (Cd) contamination (C1: 1 mg kg−1 and C10: 10 mg kg−1) was investigated on liver gene expression by real-time PCR. Genes involved in mitochondrial metabolism, in antioxidant defences,
detoxification and in DNA damage repair were studied. Metallothionein (MT) protein levels and Cd bioaccumulation were also
investigated in liver, kidneys and muscle. Male ducks were subjected to three periods of exposure: 10, 20 and 40 days. Cd
was mainly bioaccumulated in kidneys first and in liver. The concentrations in liver and kidneys appeared to reach a stable
level at 20 days of contamination even if the concentrations in muscle still increased. Cd triggered the enhancement of mitochondrial
metabolism, the establishment of antioxidant defences (superoxide dismutase Mn and Cu/Zn; catalase) and of DNA repair from
20 days of contamination. Discrepancies were observed in liver between MT protein levels and MT gene up-regulation. MT gene
expression appeared to be a late hour biomarker. 相似文献
104.
Catusse J Strub JM Job C Van Dorsselaer A Job D 《Journal de la Société de Biologie》2008,202(3):223-229
We have used proteomics to better characterize germination and early seedling vigor in sugarbeet. Our strategy includes (1) construction of proteome reference maps for dry and germinating seeds of a high-vigor reference seed lot; (2) investigation of the specific tissue accumulation of proteins (root, cotyledon, perisperm); (3) investigation of changes in protein expression profiles detected in the reference seed lot subjected to different vigor-modifying treatments, e.g. aging and/or priming. More than 1 000 sugarbeet seed proteins have been identified by LC/MS-MS mass spectrometry (albumins, globulins and glutelins have been analyzed separately). Due to the conservation of protein sequences and the quality of MS sequencing (more than 10 000 peptide sequences have been obtained), the success rate of protein identification was on the average of 80%. This is to our knowledge the best detailed proteome analysis ever carried out in seeds. The data allowed us to build a detailed metabolic chart of the sugarbeet seed, generating new insights into the molecular mechanisms determining the development of a new seedling. Also, the proteome of a seed-storage tissue as the perisperm is described for the first time. 相似文献
105.
Spectro-temporal properties of auditory cortex neurons have been extensively studied with artificial sounds but it is still unclear whether they help in understanding neuronal responses to communication sounds. Here, we directly compared spectro-temporal receptive fields (STRFs) obtained from the same neurons using both artificial stimuli (dynamic moving ripples, DMRs) and natural stimuli (conspecific vocalizations) that were matched in terms of spectral content, average power and modulation spectrum. On a population of auditory cortex neurons exhibiting reliable tuning curves when tested with pure tones, significant STRFs were obtained for 62% of the cells with vocalizations and 68% with DMR. However, for many cells with significant vocalization-derived STRFs (STRFvoc) and DMR-derived STRFs (STRFdmr), the BF, latency, bandwidth and global STRFs shape differed more than what would be predicted by spiking responses simulated by a linear model based on a non-homogenous Poisson process. Moreover STRFvoc predicted neural responses to vocalizations more accurately than STRFdmr predicted neural response to DMRs, despite similar spike-timing reliability for both sets of stimuli. Cortical bursts, which potentially introduce nonlinearities in evoked responses, did not explain the differences between STRFvoc and STRFdmr. Altogether, these results suggest that the nonlinearity of auditory cortical responses makes it difficult to predict responses to communication sounds from STRFs computed from artificial stimuli. 相似文献
106.
G Protein β Subunit–null Mutants Are Impaired in Phagocytosis and Chemotaxis Due to Inappropriate Regulation of the Actin Cytoskeleton 下载免费PDF全文
Barbara Peracino Jane Borleis Tian Jin Monika Westphal Jean-Marc Schwartz Lijun Wu Enrico Bracco Günther Gerisch Peter Devreotes Salvatore Bozzaro 《The Journal of cell biology》1998,141(7):1529-1537
Chemotaxis and phagocytosis are basically similar in cells of the immune system and in Dictyostelium amebae. Deletion of the unique G protein β subunit in D. discoideum impaired phagocytosis but had little effect on fluid-phase endocytosis, cytokinesis, or random motility. Constitutive expression of wild-type β subunit restored phagocytosis and normal development. Chemoattractants released by cells or bacteria trigger typical transient actin polymerization responses in wild-type cells. In β subunit–null cells, and in a series of β subunit point mutants, these responses were impaired to a degree that correlated with the defect in phagocytosis. Image analysis of green fluorescent protein–actin transfected cells showed that β subunit– null cells were defective in reshaping the actin network into a phagocytic cup, and eventually a phagosome, in response to particle attachment. Our results indicate that signaling through heterotrimeric G proteins is required for regulating the actin cytoskeleton during phagocytic uptake, as previously shown for chemotaxis. Inhibitors of phospholipase C and intracellular Ca2+ mobilization inhibited phagocytosis, suggesting the possible involvement of these effectors in the process. 相似文献
107.
Nikolakopoulou TL Egan S van Overbeek LS Guillaume G Heuer H Wellington EM van Elsas JD Collard JM Smalla K Karagouni AD 《Current microbiology》2005,51(4):211-216
A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (TcR) streptomycete isolates from environmental samples. Samples were obtained from bulk and rhizosphere soil, manure, activated
sludge and seawater. The majority of TcR streptomycetes originated from bulk and rhizosphere soil. Fewer TcR streptomycetes were isolated from manure and seawater and none from sewage. By PCR, three out of 217 isolates were shown
to contain the otr(A) gene and 13 out of 217 the otr(B) gene. Surprisingly, these genes were detected in taxonomic groups not known as tetracycline-producing strains. The majority
of the otr gene–carrying strains was assigned to S. exfoliatus or S. rochei and originated from all habitats from which TcR streptomycetes were obtained. Our results indicated that the occurrence of otr(A) and otr(B) genes in natural environments was limited and that otr(B), in comparison to otr(A), seemed to be more common. 相似文献
108.
FRET multiphoton spectral imaging microscopy of 7-ketocholesterol and Nile Red in U937 monocytic cells loaded with 7-ketocholesterol 总被引:1,自引:0,他引:1
Kahn E Vejux A Dumas D Montange T Frouin F Robert V Riedinger JM Stoltz JF Gambert P Todd-Pokropek A Lizard G 《Analytical and quantitative cytology and histology / the International Academy of Cytology [and] American Society of Cytology》2004,26(6):304-313
OBJECTIVE: To show the effect of 7-ketocholesterol (7KC) on cellular lipid content by means of flow cytometry and the interaction of 7KC with Nile Red (NR) via ultraviolet fluorescence resonance energy transfer (FRET) excitation of NR on U937 monocytic cells by means of 2-photon excitation confocal laser scanning microscopy (CLSM). STUDY DESIGN: Untreated and 7KC-treated U937 cells were stained with NR and analyzed by flow cytometry and CLSM. 3D sequences of images were obtained by spectral analysis in a 2-photon excitation CLSM and analyzed by the factor analysis of medical image sequences (FAMIS) algorithm, which provides factor curves and images. Factor images are the result of the FAMIS image processing method, which handles emission spectra. In FRET analysis, preparations are screened at selected UV wavelengths to avoid emission of NR in the absence of 7KC. RESULTS: During 7KC-induced cell death,flow cytometry and CLSM revealed a modification of the cellular lipid content. Factor images show FRET occurrence and subsequent colocalization of 7KC and NR. CONCLUSION: This investigation established the utility of 2-photon excitation CLSM to assess colocalization of 7KC with NR by FRET and to identify and distinguish polar and neutral lipids stained by NR that accumulate from the effect of 7KC. 相似文献
109.
110.
NMR spectroscopy has evolved dramatically over the past 15 years, establishing a new, reliable methodology for studying biomacromolecules at atomic resolution. The three-dimensional structure and dynamics of a biomolecule or a biomolecular complex is only one of the main types of information available using NMR. The spectral assignment to the specific nuclei of a biostructure is a very precise reflection of their electronic environment. Any change in this environment due to a structural change, the binding of a ligand or the redox state of a redox cofactor, will be very sensitively reported by changes in the different NMR parameters. The capabilities of the NMR method are currently expanding dramatically and it is turning into a powerful means to study biosystems dynamically in exchange between different conformations, exchanging ligands, transient complexes, or the activation/inhibition of regulated enzymes. We review here several NMR studies that have appeared during the past 5 or 6 years in the field of redox proteins of plants, yeasts and photosynthetic bacteria. These new results illustrate the recent biomolecular NMR evolution and provide new physiological models for understanding the different types of electron transfer, including glutaredoxins, thioredoxins and their dependent enzymes, the ferredoxin-NADP oxidoreductase complex, flavodoxins, the plastocyanin-cytochrome f complex, and cytochromes c. 相似文献