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971.
Françoise Lagardère Rachid Amara Lucette Joassard 《Environmental Biology of Fishes》1999,56(1-2):213-228
To evaluate the impact of metamorphosis on the vertical distribution and feeding activity of sole, Solea solea, larvae passing from offshore spawning grounds to the Bay of Vilaine, sampling series at fixed stations were carried out in April 1991 and April 1993 at depths from 50 to 30 m. Comparisons between plankton and bottom samplin series indicated differences in vertical distribution of larvae in pre-metamorphic and metamorphic steps. Metamorphosing larvae displayed a tendency to concentrate in the lower part of the water column, mainly during the day. Gut contents, analysed for prey identification, fullness index and carbon content, indicated that metamorphosing larvae fed mostly on plankton. Variations in fullness index were observed not only during the day, but also depended on tide and wind-induced mixing conditions. Larvae sampled in mixed spring-tide waters had highly variable carbon estimates, resulting in unclear diel activity. More larvae fed actively at neap-tide, which allowed the observation of a diurnal feeding activity through hourly changes in carbon estimates. It is concluded that immigrating sole were not yet able to settle but prepared themselves for demersal life (i) without undergoing starvation and (ii) by modifying the patterns of vertical distributions. The presence of a larval swimbladder suggests they can adjust their vertical movements, depending on tidal cycles, which could in turn favour coastal accumulation of metamorphosing larvae and pulses of new settlers entering the nursery grounds. 相似文献
972.
Expression of galectins in cancer: a critical review 总被引:13,自引:0,他引:13
973.
Ruiz N Merino S Viñas M Domènech O Montero MT Hernández-Borrell J 《Biophysical chemistry》2004,111(1):1-7
In this work the porin Omp1 of Serratia marcescens was expressed in a porin deficient mutant (Escherichia coli UH302) and its functionality studied following the accumulation of ciprofloxacin in bacteria. The protein was extracted, purified and reconstituted in proteoliposomes of different composition (lipopolysaccharide (LPS), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)). Maximum extraction of the detergent was achieved applying different steps of dialysis and centrifugation. Proteolipid sheets with different composition were spread onto mica and observed by atomic force microscopy. Two-dimensional crystal of Omp1 was not observed in any case due to low resolution achieved. Judging from the images features POPC is the most suitable phospholipid to enhance 2D lattice formation for Omp1. 相似文献
974.
Vermeersch JJ Christmann-Franck S Karabashyan LV Fermandjian S Mirambeau G Der Garabedian PA 《Nucleic acids research》2004,32(18):5649-5657
The present results demonstrate that pyridoxal, pyridoxal 5′-phosphate (PLP) and pyridoxal 5′-diphospho-5′-adenosine (PLP-AMP) inhibit Candida guilliermondii and human DNA topoisomerases I in forming an aldimine with the ε-amino group of an active site lysine. PLP acts as a competitive inhibitor of C.guilliermondii topoisomerase I (Ki = 40 μM) that blocks the cleavable complex formation. Chemical reduction of PLP-treated enzyme reveals incorporation of 1 mol of PLP per mol of protein. The limited trypsic proteolysis releases a 17 residue peptide bearing a lysine-bound PLP (KPPNTVIFDFLGK*DSIR). Targeted lysine (K*) in C.guilliermondii topoisomerase I corresponds to that found in topoisomerase I of Homo sapiens (K532), Candida albicans (K468), Saccharomyces cerevisiae (K458) and Schizosaccharomyces pombe (K505). In the human enzyme, K532, belonging to the active site acts as a general acid catalyst and is therefore essential for activity. The spatial orientation of K532–PLP within the active site was approached by molecular modeling using available crystallographic data. The PLP moiety was found at close proximity of several active residues. PLP could be involved in the cellular control of topoisomerases IB. It constitutes an efficient tool to explore topoisomerase IB dynamics during catalysis and is also a lead for new drugs that trap the lysine general acid. 相似文献
975.
976.
977.
Hallez S Simon P Maudoux F Doyen J Noël JC Beliard A Capelle X Buxant F Fayt I Lagrost AC Hubert P Gerday C Burny A Boniver J Foidart JM Delvenne P Jacobs N 《Cancer immunology, immunotherapy : CII》2004,53(7):642-650
Purpose: Infection with oncogenic human papillomavirus (HPV) and HPV-16 in particular is a leading cause of anogenital neoplasia. High-grade intraepithelial lesions require treatment because of their potential to progress to invasive cancer. Numerous preclinical studies have demonstrated the therapeutic potential of E7-directed vaccination strategies in mice tumour models. In the present study, we tested the immunogenicity of a fusion protein (PD-E7) comprising a mutated HPV-16 E7 linked to the first 108 amino acids of Haemophilus influenzae protein D, formulated in the GlaxoSmithKline Biologicals adjuvant AS02B, in patients bearing oncogenic HPV-positive cervical intraepithelial neoplasia (CIN). Methods: Seven patients, five with a CIN3 and two with a CIN1, received three intramuscular injections of adjuvanted PD-E7 at 2-week intervals. Three additional CIN1 patients received a placebo. CIN3 patients underwent conization 8 weeks postvaccination. Cytokine flow cytometry and ELISA were used to monitor antigen-specific cellular and antibody responses from blood taken before and after vaccine or placebo injection. Results: Some patients had preexisting systemic IFN- CD4+ (1/10) and CD8+ (5/10) responses to PD-E7. Vaccination, not placebo injection, elicited systemic specific immune responses in the majority of the patients. Five vaccinated patients (71%) showed significantly increased IFN- CD8+ cell responses upon PD-E7 stimulation. Two responding patients generated long-term T-cell immunity toward the vaccine antigen and E7 as well as a weak H. influenzae protein D (PD)–directed CD4+ response. All the vaccinated patients, but not the placebo, made significant E7- and PD-specific IgG. Conclusions: The encouraging results obtained from this study performed on a limited number of subjects justify further analysis of the efficacy of the PD-E7/AS02B vaccine in CIN patients. 相似文献
978.
Endosymbiont phylogenesis in the dryophthoridae weevils: evidence for bacterial replacement 总被引:7,自引:0,他引:7
Lefèvre C Charles H Vallier A Delobel B Farrell B Heddi A 《Molecular biology and evolution》2004,21(6):965-973
Intracellular symbiosis is widespread in the insect world where it plays an important role in evolution and adaptation. The weevil family Dryophthoridae (Curculionoidea) is of particular interest in intracellular symbiosis evolution with regard to the great economical and ecological features of these invasive insects, and the potential for comparative studies across a wide range of host plants and environments. Here, we have analyzed the intracellular symbiotic bacteria of 19 Dryophthoridae species collected worldwide, representing a wide range of plant species and tissues. All except one (Sitophilus linearis) harbor symbiotic bacteria within specialized cells (the bacteriocytes) assembled as an organ, the bacteriome. Phylogenetic analysis of the 16S rDNA gene sequence of the Dryophthoridae endosymbionts revealed three endosymbiotic clades belonging to gamma3-Proteobacteria and characterized by different GC contents and evolutionary rate. The genus name Candidatus Nardonella was proposed for the ancestral clade infesting Dryophthoridae 100 MYA and represented by five of nine bacterial genera studied. For this clade showing low GC content (40.5% GC) and high evolutionary rate (0.128 substitutions/site per 100 Myr), a single infection and subsequent cospeciation of the host and the endosymbionts was observed. In the two other insect lineage endosymbionts, with relatively high GC content (53.4% and 53.8% GC), competition with ancestral pathogenic bacteria might have occurred, leading to endosymbiont replacement in present-day last insects. 相似文献
979.
980.
A missing link in the understanding of the mechanisms of transport of the mannose 6-phosphate receptors has recently been discovered, following the identification of the protein TIP47. In association with Rab9-GTP, this protein is responsible for the return of the receptors from the late endosomes back to the trans-Golgi network. Curiously, the same protein called PP17b, was described as a placental protein twenty years ago, and more recently, as a blood marker for human uterine cervical cancer. The sequence of PP17b/TIP47 displays not only a strong homology with those of adipophilin and the perilipins, two proteins known to be involved in the intracellular traffic of lipid droplets but also PP17b/TIP47 is associated with the later. How this ubiquitous protein could participate in processes as different as the mannose 6-phosphate receptors traffic and the formation and/or traffic of lipid droplets? A tentative hypothesis is put forward. 相似文献