排序方式: 共有41条查询结果,搜索用时 15 毫秒
11.
Anna E. Grzegorzewicz Jana Korduláková Victoria Jones Sarah E. M. Born Juan M. Belardinelli Adrien Vaquié Vijay A. K. B. Gundi Jan Madacki Nawel Slama Fran?oise Laval Julien Vaubourgeix Rebecca M. Crew Brigitte Gicquel Mamadou Daffé Hector R. Morbidoni Patrick J. Brennan Annaik Quémard Michael R. McNeil Mary Jackson 《The Journal of biological chemistry》2012,287(46):38434-38441
Isoxyl (ISO) and thiacetazone (TAC), two prodrugs once used in the clinical treatment of tuberculosis, have long been thought to abolish Mycobacterium tuberculosis (M. tuberculosis) growth through the inhibition of mycolic acid biosynthesis, but their respective targets in this pathway have remained elusive. Here we show that treating M. tuberculosis with ISO or TAC results in both cases in the accumulation of 3-hydroxy C18, C20, and C22 fatty acids, suggestive of an inhibition of the dehydratase step of the fatty-acid synthase type II elongation cycle. Consistently, overexpression of the essential hadABC genes encoding the (3R)-hydroxyacyl-acyl carrier protein dehydratases resulted in more than a 16- and 80-fold increase in the resistance of M. tuberculosis to ISO and TAC, respectively. A missense mutation in the hadA gene of spontaneous ISO- and TAC-resistant mutants was sufficient to confer upon M. tuberculosis high level resistance to both drugs. Other mutations found in hypersusceptible or resistant M. tuberculosis and Mycobacterium kansasii isolates mapped to hadC. Mutations affecting the non-essential mycolic acid methyltransferases MmaA4 and MmaA2 were also found in M. tuberculosis spontaneous ISO- and TAC-resistant mutants. That MmaA4, at least, participates in the activation of the two prodrugs as proposed earlier is not supported by our biochemical evidence. Instead and in light of the known interactions of both MmaA4 and MmaA2 with HadAB and HadBC, we propose that mutations affecting these enzymes may impact the binding of ISO and TAC to the dehydratases. 相似文献
12.
Bert Vaes Damien Gruson Gijs Van Pottelbergh Agnes Pasquet Catharina Matheï Wim Adriaensen Nawel Rezzoug Jean-Louis Vanoverschelde Jan Degryse 《Peptides》2012
The hypothesis that natriuretic peptides could be used to identify ‘pancardiac’ damage has been proposed. However, multiple factors are known to influence circulating levels of natriuretic peptides, especially in the very old. Therefore, the impact of confounders on the association between natriuretic peptide levels and cardiac dysfunction was further explored in subjects aged 80 and older. A diagnostic cross-sectional study embedded within the BELFRAIL study (n = 567) was performed. Baseline BNP and NT-proBNP levels were measured and echocardiograms were performed at the subject's home. Cardiac dysfunction was defined as systolic dysfunction, valvular heart disease or isolated severe diastolic dysfunction. Several functional and structural echocardiographic parameters were independently related to circulating levels of natriuretic peptides. Cystatin C, BMI, β blockers, diabetes, heart frequency, usCRP, age and sex were identified as confounders. The prevalence of cardiac dysfunction was 17.1% in the subjects without and 30.8% in the subjects with chronic atrial fibrillation (CAF) or pacemaker (PM). Only in subjects with CAF or PM the C statistic for cardiac dysfunction improved after correcting for confounders. The post-test probability for a negative test (PTP−) ranged from 3.7% to 12.2% and the PTP+ ranged from 21.9% to 62.2% in different strata of confounders. According to these data adjusting for identified confounders does not improve the diagnostic accuracy of the natriuretic peptides for cardiac dysfunction, except in subjects with CAF or PM. Stratifying for individual confounders showed that different cut-off values could be used to optimize the diagnostic characteristics of natriuretic peptides. 相似文献
13.
14.
Khalil El Kadiri Francisco Serrano Rachid Hlila Hoda Liemlahi Ahmed Chalouan Angel Carlos López-Garrido Antonio Guerra-Merchán Carlos Sanz-de-Galdeano Karima Kerzazi Abdelaziz El Mrihi 《Facies》2005,50(3-4):477-503
The Tamezzakht succession (Maastrichtian–middle Burdigalian), situated at the fringe between the Internal and the External zones, displays contrasting lithologies with abrupt facies changes, discontinuities, and/or coarse-grained calciturbidite in between. These criteria allow the definition of seven main lithostratigraphic formations.Depositional environments (oxygenation levels, trophic conditions, omission histories, among others) and/or transgressive/regressive trends are inferred from integrated sedimentologic data including facies change, cyclicity pattern and the textural composition of the turbidite facies tracts. Special emphasis is given to the ichnological features.Taking into account the extended time-range, the position between the internal zones and the external ones, as well as the clear differentiation into several contrasting sedimentary formations, the Tamezzakht succession is expected to provide useful stratigraphic data for the regional correlations. 相似文献
15.
Aniket Magarkar Nawel Mele Noha Abdel-Rahman Sarah Butcher Mika Torkkeli Ritva Serimaa Arja Paananen Markus Linder Alex Bunker 《PLoS computational biology》2014,10(7)
Hydrophobins represent an important group of proteins from both a biological and nanotechnological standpoint. They are the means through which filamentous fungi affect their environment to promote growth, and their properties at interfaces have resulted in numerous applications. In our study we have combined protein docking, molecular dynamics simulation, and electron cryo-microscopy to gain atomistic level insight into the surface structure of films composed of two class II hydrophobins: HFBI and HFBII produced by Trichoderma reesei. Together our results suggest a unit cell composed of six proteins; however, our computational results suggest P6 symmetry, while our experimental results show P3 symmetry with a unit cell size of 56 Å. Our computational results indicate the possibility of an alternate ordering with a three protein unit cell with P3 symmetry and a smaller unit cell size, and we have used a Monte Carlo simulation of a spin model representing the hydrophobin film to show how this alternate metastable structure may play a role in increasing the rate of surface coverage by hydrophobin films, possibly indicating a mechanism of more general significance to both biology and nanotechnology. 相似文献
16.
Hela Mahmoudi Rym Kaddour Jun Huang Nawel Nasri Baâtour Olfa Sabah M’Rah Abdelali Hannoufa Mokhtar Lachaâl Zeineb Ouerghi 《Acta Physiologiae Plantarum》2011,33(5):1613-1622
Salt stress perturbs a multitude of physiological processes such as photosynthesis and growth. To understand the biochemical
changes associated with physiological and cellular adaptations to salinity, two lettuce varieties (Verte and Romaine) were
grown in a hydroponics culture system supplemented with 0, 100 or 200 mM NaCl. Verte displayed better growth under 100 mM
NaCl compared to Romaine, but both genotypes registered relatively similar reductions in growth under 200 mM NaCl treatment.
Both varieties showed differences in net photosynthetic activity in the absence of salt and 8 days after salt treatment. These
differences diminished subsequently under prolonged salt stress (14 days). Verte showed enhanced leaf proline and restricted
total cations especially Na+, lesser malondialdehyde (MDA) formation and lignification in the roots under 100 mM NaCl salinity. Membrane damage estimated
by electrolyte leakage increased with elevated salt concentrations in roots of both varieties, but Verte had significantly
lower electrolyte leakage relative to Romaine under 100 mM NaCl. Moreover, Verte also accumulated greater levels of carotenoids
under increasing NaCl concentrations compared to Romaine. Taken together, these findings suggest that the greater tolerance
of Verte to 100 mM NaCl is related to the more restricted accumulation of total cations and toxic Na+ in the roots and enhanced levels of antioxidative metabolites in root and leaf tissue. 相似文献
17.
Fabrice Compain Nawel Aït-Ammar Françoise Botterel Laure Gibault Francoise Le Pimpec Barthes Eric Dannaoui 《Mycopathologia》2017,182(9-10):907-913
We report here a case of cavitary pneumonia due to Rhizopus homothallicus in a diabetic patient. This is the first proven case of R. homothallicus infection in Western countries and the third case described worldwide. The organism was isolated from lung biopsy and identified after amplification and sequencing of the internal transcribed spacer region. 相似文献
18.
Tomentosin Induces Telomere Shortening and Caspase‐Dependant Apoptosis in Cervical Cancer Cells
下载免费PDF全文
![点击此处可从《Journal of cellular biochemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
19.
Mehrez Hammami Nawel Gaamouri Herbert Wagner Jeffrey C Pagaduan Lee Hill Pantelis T Nikolaidis Beat Knechtle Mohamed Souhaiel Chelly 《Biology of sport / Institute of Sport》2022,39(3):537
This study examined the effect of a 10-week programme of strength training with elastic band (STEB) on fitness components in young female handball players. Twenty-six young female handball players (aged 15.8 ± 0.2 years) from the same club participated in this study. They were randomly assigned between experimental (EG; n = 13) and control (CG; n = 13) groups. The EG performed the STEB, replacing some handball-specific drills in the regular handball training. The CG followed the regular handball training (i.e., mainly technical-tactical drills, small sided and simulated games, and injury prevention drills). Two-way analyses of variance were used to assess: handgrip; back extensor strength; medicine ball throw; 30 m sprint times; Modified Illinois change-of-direction (Illinois-MT); four jump tests: squat jump (SJ), countermovement jump (CMJ), countermovement jump with arm swing (CMJA) and five-jump test (5JT); static (Stork test) and dynamic balance (Y Balance Test); and repeated sprint T-test (RSTT). Results revealed significant gains in handgrip - right (p < 0.001, d = 1.75: large), handgrip - left (p < 0.001, d = 2.52: large), back extensor (p < 0.001, d = 2.01: large), and medicine ball throw (p = 0.002, d = 0.95: large) with EG compared to the CG. The EG also demonstrated greater improvement in sprint performance over 20 m (Δ = 10.6%, p = 0.001, d = 1.07: large) and 30 m (Δ = 7.2%, p < 0.0001, d = 1.56: large) compared to the CG. The EG showed better Illinois-MT (Δ = 5.6%, p = 0.034, d = 0.62: medium) compared to the CG. Further, EG posted significant improvements in the SJ (Δ = 17.3%, p = 0.048, d = 0.58: medium), CMJ (Δ = 17.7%, p = 0.017 d = 0.71: medium), and CMJA (Δ = 16.3%, p = 0.019, d = 0.69: medium) compared to the CG. Similarly, the EG exhibited significant improvement in RSTT best time [p = 0.025, d = 0.66 (medium)], RSTT mean time [p = 0.019, d = 0.69 (medium)] and RSTT total time [p = 0.019, d = 0.69 (medium)] compared to the CG. In conclusion, the 10-week STEB improved the physical abilities in young female handball players. 相似文献
20.
Previously unreported CD8(+) CD28(-) and CD8(+) CD28(+) T-cell subsets occur in healthy individuals and expand in patients suffering from autoimmune disease. Here we studied, for the first time, the expression of CD8(+) CD28(+) , CD8(+) CD28(-) , and CD8(+) CD56(+) subpopulations in induced sputum from asthmatics. Using sputum samples, purified CD8(+) T cells were stained for surface antigen CD28, CD56, FITC-conjugated anti-perforin, and anti-IFN-gamma. Cytotoxic activity was evaluated in a chromium releasing test. Induced sputum CD8(+) CD28(-) T cells were found to be more expanded and expressed low levels of IFN-gamma in severe asthmatics than mild asthma and age-matched healthy controls. The predominance of CD8(+) CD28(-) T cells can be in part explained by the expansion of CD8(+) CD56(+). CD8(+) CD28(-) T cells from severe asthmatics produced high intracytoplasmic perforin and exerted a potent cytotoxic activity. Considering their phenotyping and functional properties, the CD8(+) CD28(-) T-cell subset may constitute an intermediate phenotype in the process of CD8(+) T-cell differentiation of effector-type cells in severe asthmatics. Functional studies showed that CD8(+) CD28(-) T cells had cytotoxic function. 相似文献