排序方式: 共有59条查询结果,搜索用时 15 毫秒
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Faten Talmoudi Olfa Kilani Wiem Ayed Nizar Ben Halim Fethi Mellouli Lamia Torjmane Lamia Aissaoui Yosra Ben Youssef Lobna Kammoun Tarek Ben Othmane Mohamed Bejaoui Neila Ben Romdhane Moez Elloumi Sondes Hadiji Sofiene Hentati Imene Chemkhi Nabila Abidli Helmi Guermani Sonia Abdelhak Ahlem Amouri 《Comptes rendus biologies》2013,336(1):29-33
Fanconi anemia (FA) is a recessive chromosomal instability syndrome that is clinically characterized by multiple symptoms. Chromosome breakage hypersensitivity to alkylating agents is the gold standard test for FA diagnosis. In this study, we provide a detailed laboratory protocol for accurate assessment of FA diagnosis based on mitomycin C (MMC) test. Induced chromosomal breakage study was successful in 171 out of 205 aplastic anemia (AA) patients. According to the sensitivity of MMC at 50 ng/ml, 38 patients (22.22%) were diagnosed as affected and 132 patients (77.17%) as unaffected. Somatic mosaicism was suspected in an 11-year-old patient with a FA phenotype. Twenty-six siblings of FA patients were also evaluated and five of them (19.23%) were diagnosed as FA. From this study, a standard protocol for diagnosis of FA was developed. It is routinely used as a diagnostic test of FA in Tunisia. 相似文献
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John Nassour Patrick Hénaff Fethi Benouezdou Gordon Cheng 《Biological cybernetics》2014,108(3):291-303
In this paper, we present an extended mathematical model of the central pattern generator (CPG) in the spinal cord. The proposed CPG model is used as the underlying low-level controller of a humanoid robot to generate various walking patterns. Such biological mechanisms have been demonstrated to be robust in locomotion of animal. Our model is supported by two neurophysiological studies. The first study identified a neural circuitry consisting of a two-layered CPG, in which pattern formation and rhythm generation are produced at different levels. The second study focused on a specific neural model that can generate different patterns, including oscillation. This neural model was employed in the pattern generation layer of our CPG, which enables it to produce different motion patterns—rhythmic as well as non-rhythmic motions. Due to the pattern-formation layer, the CPG is able to produce behaviors related to the dominating rhythm (extension/flexion) and rhythm deletion without rhythm resetting. The proposed multi-layered multi-pattern CPG model (MLMP-CPG) has been deployed in a 3D humanoid robot (NAO) while it performs locomotion tasks. The effectiveness of our model is demonstrated in simulations and through experimental results. 相似文献
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Souheila Guerbouj Fattouma Djilani Jihene Bettaieb Bronwen Lambson Mohamed Fethi Diouani Afif Ben Salah Riadh Ben Ismail Ikram Guizani 《PloS one》2014,9(8)
A gp63PCR method was evaluated for the detection and characterization of Leishmania (Leishmania) (L.) parasites in canine lymph node aspirates. This tool was tested and compared to other PCRs based on the amplification of 18S ribosomal genes, a L. infantum specific repetitive sequence and kinetoplastic DNA minicircles, and to classical parasitological (smear examination and/or culture) or serological (IFAT) techniques on a sample of 40 dogs, originating from different L. infantum endemic regions in Tunisia. Sensitivity and specificity of all the PCR assays were evaluated on parasitologically confirmed dogs within this sample (N = 18) and control dogs (N = 45) originating from non–endemic countries in northern Europe and Australia. The gp63 PCR had 83.5% sensitivity and 100% specificity, a performance comparable to the kinetoplast PCR assay and better than the other assays. These assays had comparable results when the gels were southern transferred and hybridized with a radioactive probe. As different infection rates were found according to the technique, concordance of the results was estimated by (κ) test. Best concordance values were between the gp63PCR and parasitological methods (74.6%, 95% confidence intervals CI: 58.8–95.4%) or serology IFAT technique (47.4%, 95% CI: 23.5–71.3%). However, taken together Gp63 and Rib assays covered most of the samples found positive making of them a good alternative for determination of infection rates. Potential of the gp63PCR-RFLP assay for analysis of parasite genetic diversity within samples was also evaluated using 5 restriction enzymes. RFLP analysis confirmed assignment of the parasites infecting the dogs to L. infantum species and illustrated occurrence of multiple variants in the different endemic foci. Gp63 PCR assay thus constitutes a useful tool in molecular diagnosis of L. infantum infections in dogs in Tunisia. 相似文献
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Chang SC Pereira-Rodrigues N Henderson JR Cole A Bedioui F McNeil CJ 《Biosensors & bioelectronics》2005,21(6):917-922
A new approach for an amperometric array sensor platform employing arrays of sensors in a 24-well cell culture plate format has been developed for simultaneous in vitro determination of nitric oxide (NO) and superoxide free radicals (O(2)(-)) produced by stimulated cells. The work reported focuses on the direct, real-time monitoring of extracellular production of these two analytes, as well as the effects of their interaction. The sensor platform was manufactured by a combination of sputtering gold electrodes and screen-printing carbon electrodes. The O(2)(-) sensor uses covalent immobilization of cytochrome c via a binder, DTSSP (3,3'-dithio-bis(sulphosuccinimidylpropionate) onto the surface of the Au electrodes, whereas the NO sensor system involves an NiTSPc (nickel tetrasulfonated phthalocyanine) film electrodeposited onto the surface of the carbon electrodes and subsequently covered with an external layer of Nafion. For in vitro demonstration of the platforms as a potential drug-screening system, A172 glioblastoma cells were cultured and transferred into the 24-well arrays. Simultaneous and direct monitoring of NO and O(2)(-) production as a response to chemicals of biomedical relevance was carried out. The results obtained demonstrated that it would be possible to envisage a drug screening platform for compounds designed to be inhibitors of nitric oxide synthase or to have an inhibitory effect on superoxide free radical production. By suitable modification of the electrodes employed it would also be possible to extend the platform to measure alternative species. 相似文献
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Lotfi Mellouli Raoudha Ghorbel Alya Kammoun Monia Mezghani Samir Bejar 《Biotechnology letters》1996,18(7):809-814
Summary A new thermophilic Streptomyces sp. TO1, isolated from Tunisian soil, produced a thermostable alpha-amylase and pullulanase. The gene encoding for the alpha-amylase activity was cloned into the multicopy cloning plasmid pLM1 using S. lividans ZX1 as host strain. The ZX1 / pLM1 strain has the same activity than the initial TO1 strain and about 25 fold higher activity than the ZX1 strain. This alpha-amylase has an optimum of pH and temperature at 6 and 70 °C respectively. 相似文献
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Variation in the frequency of colour/pattern phenotypes of Philaenus spumarius (L.) is studied in the three local populations of Samsun (Mid-Black Sea Region), Turkey. The data, obtained from the 91 samples including 10,427 adult spittlebugs, 5,340 females and 5,087 males were analysed according to phenotype distributions in the study sites. The adult spittlebugs were collected during eleven months except with April. The mean sample size was 114.6±19.9 (Mean±S.E.) for 91 samplings. Eight different phenotypes of P spumarius were detected in the Samsun populations. Of these, four were non-melanic and four were melanic phenotypes with the lack of the “O” group. In females, non-melanic frequency was over 95%, which TYP (typicus) was the predominant phenotype, but POP (populi) in males. However the phenotype frequency distributions were not different between the sites studied. Although, frequency of females reached up to 85% in some samples, the overall sex ratio did not differ from the 1:1. 相似文献
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The marine bacteria Vibrio parahaemolyticus and V. alginolyticus were incubated in seawater for 8 months to evaluate their adaptative responses to starvation. The starved cells showed an
altered biochemical and enzymatic profiles, respectively, on Api 20E and Api ZYM systems and an evolution to the filterable
minicells state capable to pass membrane pore size 0.45 μm. Outer membrane proteins patterns of stressed bacteria were also
altered. Indeed, these modifications were manifested by the appearance and/or disappearance of bands as well as in the level
of expression of certain proteins. Plasmids profiles analysis showed that V. alginolyticus ATCC 33787 lost three plasmids, whereas other tested strains conserved their initial profiles. 相似文献
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In this study, the amounts of antioxidant vitamins (A, E and C), selenium (Se), reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio and malondialdehyde (MDA) that is the indicator of lipid peroxidation were determined in Lemna gibba L. plants placed in the secondary clarifier and grown in natural water. The amounts of antioxidant vitamins (A, E and C), GSH, GSSG and MDA were determined with HPLC (high performance liquid chromatography) and the amounts of Se were determined fluorimetrically. While significant decrease in amounts of antioxidant vitamins (A, E and C) and Se takes place between the first and the second or third day depending on species and insignificant decrease takes place after that day, the amount of GSH/GSSG ratio decreases until the second day (p < 0.05) and insignificantly increases after that day. Amounts of vitamins (A, E and C), Se and GSH/GSSG ratio for the plants placed in the secondary clarifier are much less than that for control group while an opposite trend was observed in MDA level. The MDA for the plants placed in secondary clarifier has maximum value at the second day, which can be considered as the maximum stress occurring at that day. Consequently, the first two days of treatment time can be taken as acclimation time and after the acclimation time the plant lives in the hostile environmental condition with the certain amount of oxidative stress. As a result, it is determined that wastewater decreases the lifetime of plant by causing metabolic stress on it and affects antioxidant capacity. The lifetime of the plants in the secondary clarifier was determined to be five days since fading toward yellow color (necrosis) in the plants was observed at the fifth day. 相似文献
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Bahareh Noshadi Tugba Ercetin Chiara Luise Mine Yarim Yuksel Wolfgang Sippl Mustafa Fethi Sahin Mustafa Gazi Hayrettin Ozan Gulcan 《化学与生物多样性》2020,17(8)
Urolithins (that is, hydroxy substituted benzo[c]chromen‐6‐one derivatives) are formed within the gastrointestinal tract following to the exposure to various ellagitannin rich diet, particularly involving pomegranate, nuts, and berries. Regarding the bioavailability deficiency of ellagitannins, the biological activities obtained through the extracts of these dietaries are attributed to the urolithin compounds, since they are bioavailable. Particularly, there are studies indicating the importance of ellagitannin‐rich food for protective and alternative treatment of Alzheimer's Disease (AD). From this perspective, within this study, the major urolithins (that is, urolithins A and B), their methyl ether metabolites, as well as some synthetic urolithin analogs have been synthesized and screened for their biological activities in various enzyme inhibition (acetylcholinesterase, butyrylcholinesterase, monoamine oxidase B, cyclooxygenase 1, and cyclooxygenase 2) and antioxidant (DPPH radical scavenging) assay systems. The results pointed out the potential of urolithins to act as inhibitors on these receptors. Docking studies were also performed to investigate the possible interactions. 相似文献