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81.
Rafik Errakhi Francois Bouteau Ahmed Lebrihi Mustapha Barakate 《World journal of microbiology & biotechnology》2007,23(11):1503-1509
Ten antibiotic-producing Streptomyces spp. isolated from Moroccan soils were evaluated for their ability to inhibit in vitro Sclerotium rolfsii development. Four isolates having the greatest pathogen inhibitory capabilities were subsequently tested for their ability
to inhibit sclerotial germination in sterile soil. This test was carried out by using biomass inoculum, culture filtrate,
and spore suspension of the isolates as treatment. Treatment with biomass inoculum and culture filtrate gave the highest inhibition
of sclerotia. Biological control tests against Sclerotium rolfsii damping-off of sugar beet seeds showed that the selected Streptomyces isolates reduced significantly the disease severity, the J-2 isolate being the more potent. In addition, treatment with the
isolate J-2 resulted in a significant increase (P ≤ 0.05) in seedling development compared to the control. All antagonistic Streptomyces selected here were able to grow in the rhizosphere soil from infected sugar beet culture. 相似文献
82.
Pierre Bouillot Olivier Brina Rafik Ouared Karl-Olof Lovblad Mohamed Farhat Vitor Mendes Pereira 《PloS one》2014,9(12)
We investigated the flow modifications induced by a large panel of commercial-off-the-shelf (COTS) intracranial stents in an idealized sidewall intracranial aneurysm (IA). Flow velocities in IA silicone model were assessed with and without stent implantation using particle imaging velocimetry (PIV). The use of the recently developed multi-time-lag method has allowed for uniform and precise measurements of both high and low velocities at IA neck and dome, respectively. Flow modification analysis of both regular (RSs) and flow diverter stents (FDSs) was subsequently correlated with relevant geometrical stent parameters. Flow reduction was found to be highly sensitive to stent porosity variations for regular stents RSs and moderately sensitive for FDSs. Consequently, two distinct IA flow change trends, with velocity reductions up to 50% and 90%, were identified for high-porosity RS and low-porosity FDS, respectively. The intermediate porosity (88%) regular braided stent provided the limit at which the transition in flow change trend occurred with a flow reduction of 84%. This transition occurred with decreasing stent porosity, as the driving force in IA neck changed from shear stress to differential pressure. Therefore, these results suggest that stents with intermediate porosities could possibly provide similar flow change patterns to FDS, favourable to curative thrombogenesis in IAs. 相似文献
83.
Henrik O. Berdel Hongyu Yin Jun Yao Liu Karolina Grochowska Christopher Middleton Nathan Yanasak Rafik Abdelsayed Wolfgang E. Berdel Mahmood Mozaffari Jack C. Yu Babak Baban 《PloS one》2014,9(12)
Purpose
The inhibition of serum glucocorticoid-regulated kinase-1 (SGK-1) has been found to decrease growth of colon and prostate cancer cells. The purpose of this study is to evaluate the therapeutic effect of SGK-1 inhibition in head and neck squamous cell carcinoma (SCC).Experimental Design
Human head and neck tumors (HTB41/43) were established in athymic mice. Growth rates between mice treated with vehicle (PBS) injection (group 1, n = 5), SGK-1 Inhibitor GSK 650394 (group 2, n = 6), systemic cisplatin (group 3, n = 6), and a combination of SGK-1 Inhibitor and cisplatin (group 4, n = 6) were compared using repeated measures one-way ANOVA with Newman-Keuls Multiple Comparison Test. Tumor cells were subsequently submitted to further analyses.Results
At the end of the experiment mean tumor sizes were 122.33+/−105.86, 76.73+/−36.09, 94.52+/−75.92, and 25.76+/−14.89 mm2 (mean +/− SD) for groups 1 to 4. Groups 2 and 3 showed decreased tumor growth compared to controls (p<0.001). Group 4 displayed even greater growth suppression (p<0.0001). Importantly, group 4 fared better than group 3 (p<0.001). CD44 expression was reduced in group 2 (p<0.05), and to an even greater extent in groups 3 and 4 (p<0.0025). A trend towards reduction of HER 2 expression was noted in group 4.Conclusions
SGK-1 inhibition suppresses tumor growth, and in combination with systemic cisplatin exceeds the effect of cisplatin alone. Decreased expression of CD44 and HER 2 implies depletion of tumor stem cells, and less tumorigenicity. SGK-1 inhibition represents a potential modality of local control for palliation in advanced cases. 相似文献84.
85.
Rafik Dey Jacques Bodennec Mouh Oulhadj Mameri & Pierre Pernin 《FEMS microbiology letters》2009,290(1):10-17
Legionella pneumophila is known as a facultative intracellular parasite of free-living soil and freshwater amoebae, of which several species have been shown to support the growth of the pathogenic bacteria. We report for the first time the behaviour of two strains (c2c and Z503) of the amoeba Willaertia magna towards different strains of L. pneumophila serogroup 1 and compared it with Acanthamoeba castellanii and Hartmannella vermiformis , known to be L. pneumophila permissive. In contrast to the results seen with other amoebae, W. magna c2c inhibited the growth of one strain of Legionella ( L. pneumophila , Paris), but not of others belonging to the same serogroup ( L. pneumophila , Philadelphia and L. pneumophila , Lens). Also, the different L. pneumophila inhibited cell growth and induced cell death in A. castellanii, H. vermiformis and W. magna Z503 within 3–4 days while W. magna c2c strain remained unaffected even up to 7 days. Electron microscopy demonstrated that the formation of numerous replicative phagosomes observed within Acanthamoeba and Hartmannella is rarely seen in W. magna c2c cocultured with L. pneumophila . Moreover, the morphological differences were observed between L. pneumophila cultured either with Willaertia or other amoebae. These observations show that amoebae are not all equally permissive to L. pneumophila and highlight W. magna c2c as particularly resistant towards some strains of this bacterium. 相似文献
86.
Bastien Chopard Rafik Ouared Andreas Deutsch Haralambos Hatzikirou Dieter Wolf-Gladrow 《Acta biotheoretica》2010,58(4):329-340
Lattice-gas cellular automaton (LGCA) and lattice Boltzmann (LB) models are promising models for studying emergent behaviour
of transport and interaction processes in biological systems. In this chapter, we will emphasise the use of LGCA/LB models
and the derivation and analysis of LGCA models ranging from the classical example dynamics of fluid flow to clotting phenomena
in cerebral aneurysms and the invasion of tumour cells. 相似文献
87.
Rafik Karmali Serge N. Schiffmann Jean-Marie Vanderwinden Geoffrey N. Hendy Nicole Nys-DeWolf Jacques corvilain Pierre Bergmann Jean-Jacques Vanderhaeghen 《Cell and tissue research》1992,270(3):597-600
Summary Previous studies have indicated that 19-dayold fetal long bones of the rat contain an adenylyl cyclase-stimulating activity antigenically related to parathyroid hormone-related peptide. To ascertain its origin, Northern blotting and in situ hybridization histochemistry were performed. Results demonstrate that mRNA of parathyroid hormone-related peptide is present in RNA extracted from fetal long bones of the rat and that cells responsible for its production are localized in the periosteum. These cells are not mature osteoblasts because they do not synthesize mRNA of osteocalcin. Thus the present study shows that parathyroid hormone-related peptide could be produced locally, at least in part, in the skeleton of fetal rats. 相似文献
88.
Abdulrahim Abu-Jayyab Ezz-Eddin S. M. El-Denshary Abdulrahman M. Ageel Mohamed Rafik Dakkak 《Bioscience reports》1987,7(10):751-755
Short-term and long-term effects of bromocriptine mesylate (10 mg/kg i.p.) on cyclic AMP contents of the liver and some endocrine glands have been investigated in the presence and absence of sulpiride (10 mg/kg i.p.). Results revealed that bromocriptine caused significant elevations in the cyclic AMP contents of the liver and reduction in its adrenocortical content. Bromocriptine effect on the adrenal cortex was antagonized by sulpiride, whereas its effect on the liver was not changed. Bromocriptine did not change the, cyclic AMP content in the thyroid gland or the ovary. 相似文献
89.
90.
The DFT and HF calculation results for the proton transfer reactions of three different systems reveal that the reaction mechanism (transfer of a proton to a nucleophile) is largely determined by the distance between the two reactive centers (r).Systems with relatively large r values tend to abstract a proton from a molecule of water, whereas, these with a relatively small r values prefer to be engaged intramolecularly and their interaction with water is only via hydrogen bonding. Further, the results indicate that the effective molarity (log EM) for an intramolecular process is strongly correlated with the distance between the two reacting centers (r) in accordance with Menger’s “spatiotemporal hypothesis”. 相似文献