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991.
Comparison of mRNA gene expression by RT-PCR and DNA microarray 总被引:10,自引:0,他引:10
992.
Monceaux V Viollet L Petit F Ho Tsong Fang R Cumont MC Zaunders J Hurtrel B Estaquier J 《Journal of immunology (Baltimore, Md. : 1950)》2005,174(11):6898-6908
Immunological and virological events that occur during the earliest stages of HIV-1 infection are now considered to have a major impact on subsequent disease progression. We observed changes in the frequencies of CD8(bright) T cells expressing different chemokine receptors in the peripheral blood and lymph nodes of rhesus macaques during the acute phase of the pathogenic SIVmac251 infection; the frequency of CD8(bright) T cells expressing CXCR4 decreased, while the frequency of those expressing CCR5 increased. These reciprocal changes in chemokine receptor expression were associated with changes in the proportion of cycling (Ki67(+)) CD8(bright) T cells, and with the pattern of CD8(bright) T cell differentiation as defined by expression of CCR7 and CD45RA. In contrast, during the primary phase of the attenuated SIVmac251Deltanef infection, no major change was observed. Whereas during the acute phase of the infection with pathogenic SIV (2 wk postinfection) no correlate of disease protection was identified, once the viral load set points were established (2 mo postinfection), we found that the levels of cycling and of CCR5- and CXCR4-positive CD8(bright) T cells were correlated with the extent of viral replication and therefore with SIV-infection outcome. Our data reveal that, during primary SIV infection, despite intense CD8 T cell activation and an increase in CCR5 expression, which are considered as essential for optimal effector function of CD8(+) T cells, these changes are associated with a poor prognosis for disease progression to AIDS. 相似文献
993.
Mercier R Jolivet S Vezon D Huppe E Chelysheva L Giovanni M Nogué F Doutriaux MP Horlow C Grelon M Mézard C 《Current biology : CB》2005,15(8):692-701
BACKGROUND: Crossovers are essential for the completion of meiosis. Recently, two pathways of crossover formation have been identified on the basis of distinct genetic controls. In one pathway, crossover inhibits the occurrence of another such event in a distance-dependent manner. This phenomenon is known as interference. The second kind of crossover is insensitive to interference. The two pathways function independently in budding yeast. Only interference-insensitive crossovers occur in Schizosaccharomyces pombe. In contrast, only interference-sensitive crossovers occur in Caenorabditis elegans. The situation in mammals and plants remains unclear. Mer3 is one of the genes shown to be required for the formation of interference-sensitive crossovers in Saccharomyces cerevisiae. RESULTS: To unravel the crossover status in the plant Arabidopsis thaliana, we investigated the role of the A. thaliana MER3 gene through the characterization of a series of allelic mutants. All mer3 mutants showed low levels of fertility and a significant decrease (about 75%) but not a total disappearance of meiotic crossovers, with the number of recombination events initiated in the mutants being similar to that in the wild-type. Genetic analyses showed that the residual crossovers in mer3 mutants did not display interference in one set of adjacent intervals. CONCLUSIONS: Mutation in MER3 in Arabidopsis appeared to be specific to recombination events resulting in interference-sensitive crossovers. Thus, MER3 function is conserved from yeast to plants and may exist in other metazoans. Arabidopsis therefore has at least two pathways for crossover formation, one giving rise to interference-sensitive crossover and the other to independently distributed crossovers. 相似文献
994.
Schneider R Schmitt F Frochot C Fort Y Lourette N Guillemin F Müller JF Barberi-Heyob M 《Bioorganic & medicinal chemistry》2005,13(8):2799-2808
Photodynamic therapy (PDT) is a cancer treatment involving systemic administration of a tumor-localizing photosensitizer; this, when activated by the appropriate light wavelength, interacts with molecular oxygen to form a toxic, short-lived species known as singlet oxygen, which is thought to mediate cellular death. Targeted PDT offers the opportunity of enhancing photodynamic efficiency by directly targeting diseased cells and tissues. Two new conjugates of three components, folic acid/hexane-1,6-diamine/4-carboxyphenylporphyrine 1 and folic acid/2,2'-(ethylenedioxy)-bis-ethylamine/4-carboxyphenylporphyrine 2 were synthesized. The conjugates were characterized by 1H NMR, MALDI, UV-visible spectroscopy, and fluorescence quantum yield. The targeted delivery of these photoactive compounds to KB nasopharyngeal cell line, which is one of the numerous tumor cell types that overexpress folate receptors was studied. It was found that after 24 h incubation, conjugates 1 and 2 cellular uptake was on average 7-fold higher than tetraphenylporphyrin (TPP) used as reference and that 1 and 2 cellular uptake kinetics increased steadily over the 24 h period, suggesting an active transport via receptor-mediated endocytosis. In corresponding results, conjugates 1 and 2 accumulation displayed a reduction of 70% in the presence of a competitive concentration of folic acid. Survival measurements demonstrated that KB cells were significantly more sensitive to conjugated porphyrins-mediated PDT. Under the same experimental conditions and the same photosensitizer concentration, TPP displayed no photocytotoxicity while conjugates 1 and 2 showed photodynamic activity with light dose values yielding 50% growth inhibition of 22.6 and 6.7 J/cm2, respectively. 相似文献
995.
The ectopic expression of antibody fragments inside mammalian cells (intrabodies) is a challenging approach for probing and modulating target activities. We previously described the shuttling activity of intracellularly expressed Escherichia coli beta-galactosidase conferred by the single-chain Fv (scFv) fragment 13R4 equipped with nuclear import/export signals. Here, by appending to scFvs the proteolytic PEST signal sequence (a protein region rich in proline, glutamic acid, serine and threonine) of mouse ornithine decarboxylase, we tested whether short-lived or destabilized intrabodies could affect the steady-state level of target by redirecting it to the proteasomes. In the absence of antigen, the half-life of the modified scFv 13R4, relative to untagged molecules, was considerably reduced in vivo. However, after coexpression with either cytoplasmic or nuclear antigen, the destabilized 13R4 fragments were readily maintained in the cell and strictly colocalized with beta-galactosidase. Analysis of destabilized site-directed mutants, that were as soluble as 13R4 in the intracellular context, demonstrated that binding to antigen was essential for survival under these conditions. This unique property allowed specific detection of beta-galactosidase, even when expressed at low level in stably transformed cells, and permitted isolation by flow cytometry from a transfected cell mixture of those living cells specifically labeled with bound intrabody. Altogether, we show that PEST-tagged intrabodies of sufficient affinity and solubility are powerful tools for imaging the presence and likely the dynamics of protein antigens that are resistant to proteasomal degradation in animal cells. 相似文献
996.
Thomas?Fett Laurent?LM?Zecchinon Etienne?A?Baise Daniel?JM?DesmechtEmail author 《BMC veterinary research》2005,1(1):4
Background
Lymphocyte function-associated antigen-1 (LFA-1, CD11a/CD18, alpha L beta 2) is required for many cellular adhesive interactions during the immune response.Results
The Capra hircus CD11a-encoding cDNA was sequenced and compared with its human, murine, rat, bovine and ovine counterparts. Despite some focal differences, it shares all the main characteristics of its known mammalian homologues.Conclusion
Therefore, along with the caprine CD18-encoding cDNA, which has been available for a few months, the sequence data revealed here will allow the Capra hircus LFA-1 expression in vitro as a tool to explore the specificities of inflammation in the caprine species.997.
Raphaël Jumeau Phuc Félix Nguyen-Tan Houda Bahig Xavier Liem Louise Lambert Matthieu Schmittbuhl Dany Simard Edith Filion 《Reports of Practical Oncology and Radiotherapy》2018,23(4):270-275
Aim
To develop a tool in order to guide pre-irradiation dental care (PIDC) for patients with oropharyngeal cancers.Background
Osteoradionecrosis of the jaws is a potential complication of radiotherapy (RT) for head and neck cancers. To prevent this complication, PIDC can involve multiple dental extractions as a preventative measure to avoid post-RT complications. However, there is no standardized tool to guide PIDC.Materials and methods
From January 2005 to October 2015, 120 head and neck cancer patients were prospectively included in a study investigating dysgeusia after RT. From this cohort, patients were enrolled according to the following inclusion criteria: histopathological confirmation of oropharyngeal squamous cell carcinoma; stage T1-4 N1-3 M0; ≤10 missing teeth. Individual teeth were retrospectively delineated on planning computed tomography and doses to dentition were assessed to generate templates.Results
Thirty-three patients were included. Molars received highest doses with a mean dose of 50?Gy (range; 19–75?Gy). Ipsi-lateral and contralateral wisdom teeth received RT dose superior to 50?Gy in 92% and 56% of cases, respectively. Patients with advanced disease (T4 or N2c-3) received higher mean doses on inferior and ipsi-lateral dental arches compared to other patients (T1-3 N0-2b): 42?Gy vs. 39?Gy and 44?Gy vs. 39?Gy (p?<?0.05), respectively.Conclusion
Pre-RT dose distribution templates are an objective way to prepare PIDC. Further studies with a larger cohort are needed to validate these templates. 相似文献998.
999.
Assigning function to natural allelic variation via dynamic modeling of gene network induction
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1000.
Douglas Moreira de Oliveira Nathália Bandeira Diniz Carolina Etienne de Rosália e Silva Santos Sérgio Luiz Ferreira da Silva Adriano do Nascimento Simões 《Journal of Plant Interactions》2018,13(1):91-99
This study evaluated the influence of Azospirillum lipoferum on the growth of Myracroduon urundeuva (Anacardiaceae) plants under drought stress, by means of biometric, physical–chemical and biochemical parameters. The association of A. lipoferum with the roots of the plants provided increases of 30% root length, 50% root dry weight, 34% shoot dry weight and 10% soluble protein content. The inoculated plants still maintained 5% higher leaf water potential than those not inoculated and lower membrane damage. Furthermore, the inoculated plants shown less leaf fall and dark green leaves, confirmed by maintenance of the highest levels of chlorophyl a, b and total. On the other hand, superoxide dismutase activity was significantly lower in the inoculated plants, possibly due to the induction of a non-enzymatic protective feature. In this way, the inoculation of PGPR in M. urundeuva can be an alternative for the production of plants that are more tolerant to drought stress. 相似文献