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排序方式: 共有2242条查询结果,搜索用时 15 毫秒
101.
Orefice Ida Di Dato Valeria Sardo Angela Lauritano Chiara Romano Giovanna 《Aquatic Ecology》2022,56(2):377-397
Aquatic Ecology - Diatoms are eukaryotic microalgae representing one of the major groups in the marine phytoplankton, accounting for up to 40% of annual productivity at sea. They are widely... 相似文献
102.
Giacomo Pozzoli Hany E. Marei Asma Althani Alma Boninsegna Patrizia Casalbore Lionel N. J. L. Marlier Giulia Lanzilli Manuela Zonfrillo Giovanna Petrucci Bianca Rocca Pierluigi Navarra Alessandro Sgambato Carlo Cenciarelli 《Journal of cellular physiology》2019,234(9):15459-15471
Several clinical studies indicated that the daily use of aspirin or acetylsalicylic acid reduces the cancer risk via cyclooxygenases (Cox-1 and Cox-2) inhibition. In addition, aspirin-induced Cox-dependent and -independent antitumor effects have also been described. Here we report, for the first time, that aspirin treatment of human glioblastoma cancer (GBM) stem cells, a small population responsible for tumor progression and recurrence, is associated with reduced cell proliferation and motility. Aspirin did not interfere with cell viability but induced cell-cycle arrest. Exogenous prostaglandin E2 significantly increased cell proliferation but did not abrogate the aspirin-mediated growth inhibition, suggesting a Cox-independent mechanism. These effects appear to be mediated by the increase of p21 waf1 and p27 Kip1, associated with a reduction of Cyclin D1 and Rb1 protein phosphorylation, and involve the downregulation of key molecules responsible for tumor development, that is, Notch1, Sox2, Stat3, and Survivin. Our results support a possible role of aspirin as adjunctive therapy in the clinical management of GBM patients. 相似文献
103.
Daniela Accili Maura Menghi Giovanni Materazzi Giovanna Menghi 《The Histochemical journal》2001,33(6):363-371
Sialoglycoconjugates in rat sublingual gland acinar cells, at different stages of pre- and post-natal development, were investigated in situ with specific lectins and by the selective removal of terminal sialic acids. Cleavage of acetyl substituents sited in the pyranose ring and/or polyhydroxyl side chain was used as an additional means of characterising the glycoconjugates. The first expression of terminal sialic acid linked to -galactose was found at gestational day 17 and progressive different derivatives were observed. The terminal disaccharide sialic acid-N-acetylgalactosamine was constantly visualized in the sublingual gland from gestational day 18. In both terminal disaccharides, sialic acids were characterized by variable degrees of acetylation and were found to be highly packaged and responsible for the hydration coat. The complex data obtained indicated that the sublingual gland is characterized by a marked fluctuation of complex sialoglycoconjugates that differ from those in the submandibular gland of the same species. 相似文献
104.
Giovanna De Matteis Enzo Agostinelli Bruno Mondovì L. Morpurgo 《Journal of biological inorganic chemistry》1999,4(3):348-353
Bovine serum amine oxidase (BSAO) reacts with 2-hydrazinopyridine, which binds the organic cofactor 2,4,5-trihydroxyphenylalanine
quinone, forming a band at 435 nm. The band shifts to 526 nm around 60 °C, to 415 nm upon denaturation, but only shifts to
429 nm upon Cu2+ depletion. Its wavelength and intensity suggest that the adduct has the azo conformation, whilst the same adduct of crystallineEscherichia coli amine oxidase (ECAO) shows the hydrazone conformation in the X-ray structure. The steady state kinetics of aminomethyl- and
aminoethylpyridines confirm that the formation of the product Schiff base, analogous to the azo form of the 2-hydrazinopyridine
adduct, is not hindered in solution. The structural stability of the adduct in the absence of Cu2+ is taken to imply hydrogen bonding of the pyridyl nitrogen to a conserved aspartate, as in the ECAO adduct. Thus the ECAO
adduct provides a good model for a transient intermediate leading to formation of the BSAO azo adduct. On the basis of this
model and of the catalytic competence of Co2+-substituted BSAO, confirmed by the present data, a catalytic reaction scheme is proposed.
Received: 2 December 1998 / Accepted: 22 March 1999 相似文献
105.
B. Yassine-Diab P. Carmichael Fatima-Ezzahra L'Faqihi Giovanna Lombardi Sarah Deacock Claude de Préval Hélène Coppin R. I. Lechler 《Immunogenetics》1999,49(6):532-540
A comprehensive analysis was carried out of the tri-molecular complex of peptide, major histocompatibility class II molecule,
and T-cell receptor (TcR) involved in the recognition of the promiscuous HA (306–318) peptide, restricted by one of two closely
related HLA-DR alleles, HLA-DRB1*0101 and HLA-DRB1*0103. These two DR molecules differ by only three amino acids at positions 67, 70, and 71, in the third variable region of the
DRB1 chain. None of the HA (306–318)-specific T-cell clones restricted by these two DR molecules tolerated amino acid substitution
at the peptide-binding position 71, despite the fact that the substitution did not interfere with peptide binding. The majority
of the DRB1*0103-restricted clones tolerated substitution of the amino acid at the TcR-contacting position 70, while the DRB1*0101-restricted
T cells did not. Biased usage of TRVA and TRVB segments was observed for the DRB1*0103-restricted clones; in contrast, apparently
random usage was seen in the DRB1*0101-restricted T cells. Finally, limiting dilution analysis revealed a lower frequency
of T cells reactive with the HA peptide in a DRB1*0103 compared with a DRB1*0101 individual. Taken together these data suggest
that biased TcR gene usage may reflect a relatively low precursor frequency of T cells, and the need for clonal expansion of a limited set
of high avidity T cells.
Received: 7 August 1998 / Revised: 19 November 1998 相似文献
106.
Semprini S Capon F Bovolenta S Bruscia E Pizzuti A Fabrizi G Schietroma C Zambruno G Dallapiccola B Novelli G 《Human genetics》1999,104(2):130-134
107.
PTX3 plays a key role in the organization of the cumulus oophorus extracellular matrix and in in vivo fertilization 总被引:9,自引:0,他引:9
Salustri A Garlanda C Hirsch E De Acetis M Maccagno A Bottazzi B Doni A Bastone A Mantovani G Beck Peccoz P Salvatori G Mahoney DJ Day AJ Siracusa G Romani L Mantovani A 《Development (Cambridge, England)》2004,131(7):1577-1586
PTX3 is a prototypic long pentraxin that plays a non-redundant role in innate immunity against selected pathogens and in female fertility. Here, we report that the infertility of Ptx3(-/-) mice is associated with severe abnormalities of the cumulus oophorus and failure of in vivo, but not in vitro, oocyte fertilization. PTX3 is produced by mouse cumulus cells during cumulus expansion and localizes in the matrix. PTX3 is expressed in the human cumulus oophorus as well. Cumuli from Ptx3(-/-) mice synthesize normal amounts of hyaluronan (HA), but are unable to organize it in a stable matrix. Exogenous PTX3 restores a normal cumulus phenotype. Incorporation in the matrix of inter-alpha-trypsin inhibitor is normal in Ptx3(-/-) cumuli. PTX3 does not interact directly with HA, but it binds the cumulus matrix hyaladherin tumor necrosis factor alpha-induced protein 6 (TNFAIP6, also known as TSG6) and thereby may form multimolecular complexes that can cross-link HA chains. Thus, PTX3 is a structural constituent of the cumulus oophorus extracellular matrix essential for female fertility. 相似文献
108.
109.
Caretto S Bray Speth E Fachechi C Gala R Zacheo G Giovinazzo G 《Plant cell reports》2004,23(3):174-179
The most biologically active component of vitamin E, -tocopherol, is synthesized in its most effective stereoisomeric form only by photosynthetic organisms. Using sunflower cell cultures, a suitable in vitro production system of natural -tocopherol was established. The most efficient medium was found to be MS basal medium with naphthaleneacetic acid and 6-benzylaminopurine with the addition of casaminoacids and myo-inositol. Culture feeding experiments using biosynthetic precursors showed that -tocopherol production improved by 30% when homogentisic acid was used. Interestingly, time-course experiments with sunflower suspension cultures showed a possible increase of 78% in -tocopherol production when using cultures of longer subculture intervals. Compared to the starting plant tissue, an overall 100% increase of -tocopherol was reached by these sunflower cell cultures. 相似文献
110.
Romagnoli R Baraldi PG Pavani MG Tabrizi MA Moorman AR Di Virgilio F Cattabriga E Pancaldi C Gessi S Borea PA 《Bioorganic & medicinal chemistry letters》2004,14(22):5709-5712
The design, synthesis, and preliminary biological evaluation of the first potent radioligand antagonist for the P2X(7) receptor, named [(3)H]-1-[(S)-N,O-bis-(isoquinolinesulfonyl)-N-methyl-tyrosyl]-4-(o-tolyl)-piperazine (compound 13), are reported. This compound bound to human P2X(7) receptors expressed in HEK transfected cells with K(D) and B(max) value of 3.46+/-0.1 nM and 727+/-73 fmol/mg of protein, respectively. The high affinity and facile labeling makes it a promising radioligand for a further characterization of P2X(7) receptor subtype. 相似文献