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21.
22.
Guillaume Allorent Ryutaro Tokutsu Thomas Roach Graham Peers Pierre Cardol Jacqueline Girard-Bascou Daphné Seigneurin-Berny Dimitris Petroutsos Marcel Kuntz Cécile Breyton Fabrice Franck Francis-André Wollman Krishna K. Niyogi Anja Krieger-Liszkay Jun Minagawa Giovanni Finazzi 《The Plant cell》2013,25(2):545-557
Absorption of light in excess of the capacity for photosynthetic electron transport is damaging to photosynthetic organisms. Several mechanisms exist to avoid photodamage, which are collectively referred to as nonphotochemical quenching. This term comprises at least two major processes. State transitions (qT) represent changes in the relative antenna sizes of photosystems II and I. High energy quenching (qE) is the increased thermal dissipation of light energy triggered by lumen acidification. To investigate the respective roles of qE and qT in photoprotection, a mutant (npq4 stt7-9) was generated in Chlamydomonas reinhardtii by crossing the state transition–deficient mutant (stt7-9) with a strain having a largely reduced qE capacity (npq4). The comparative phenotypic analysis of the wild type, single mutants, and double mutants reveals that both state transitions and qE are induced by high light. Moreover, the double mutant exhibits an increased photosensitivity with respect to the single mutants and the wild type. Therefore, we suggest that besides qE, state transitions also play a photoprotective role during high light acclimation of the cells, most likely by decreasing hydrogen peroxide production. These results are discussed in terms of the relative photoprotective benefit related to thermal dissipation of excess light and/or to the physical displacement of antennas from photosystem II. 相似文献
23.
Background
Nulliparity is a major risk factor of preeclampsia investigated in numerous trials of its prevention.Objective
We aimed to assess whether these trials considered nulliparity in subject selection or analysis of results.Search Strategy
01 April 2013 search of MEDLINE via PubMed, EMBASE and the Cochrane Library. 01 April 2013 search of trials registered in Clinicaltrials.gov.Selection Criteria
Randomised controlled trials and metaanalyses of preeclampsia prevention with no restriction to period of publication or language. Metaanalyses were selected to fully identify relevant trials.Data Collection and Analysis
One reader appraised each selected article/registered protocol using a pretested, standardized data abstraction form developed in a pilot test. For each article, he recorded whether both nulliparous and multiparous were included and, in case of mixed populations, whether randomisation was stratified, and whether subgroup analyses had been reported. For registered protocols, he only assessed whether it was planned to include mixed populations.Main Results
88 randomised controlled trials were identified, representing 83,396 included women. In 58 of the 88 articles identified (65.9%), preeclampsia was the primary outcome. In 31 of these (53.4%), the investigation combined nulliparous and multiparous women; only two reports in 31 (6.5%) stated that randomisation was stratified on parity and only four (12.9%) described a subgroup analysis by parity. Of the 30 registered trials, 20 (66.6%) planned to include both nulliparous and multiparous women.Conclusion
Parity is largely ignored in randomised controlled trials of preeclampsia prevention, which raises difficulties in interpreting the results. 相似文献24.
Keith K. Fenrich Pascal Weber Genevieve Rougon Franck Debarbieux 《Journal of visualized experiments : JoVE》2013,(82)
Experimental autoimmune encephalomyelitis (EAE) in adult rodents is the standard experimental model for studying autonomic demyelinating diseases such as multiple sclerosis. Here we present a low-cost and reproducible glass window implantation protocol that is suitable for intravital microscopy and studying the dynamics of spinal cord cytoarchitecture with subcellular resolution in live adult mice with EAE. Briefly, we surgically expose the vertebrae T12-L2 and construct a chamber around the exposed vertebrae using a combination of cyanoacrylate and dental cement. A laminectomy is performed from T13 to L1, and a thin layer of transparent silicone elastomer is applied to the dorsal surface of the exposed spinal cord. A modified glass cover slip is implanted over the exposed spinal cord taking care that the glass does not directly contact the spinal cord. To reduce the infiltration of inflammatory cells between the window and spinal cord, anti-inflammatory treatment is administered every 2 days (as recommended by ethics committee) for the first 10 days after implantation. EAE is induced only 2-3 weeks after the cessation of anti-inflammatory treatment.Using this approach we successfully induced EAE in 87% of animals with implanted windows and, using Thy1-CFP-23 mice (blue axons in dorsal spinal cord), quantified axonal loss throughout EAE progression. Taken together, this protocol may be useful for studying the recruitment of various cell populations as well as their interaction dynamics, with subcellular resolution and for extended periods of time. This intravital imaging modality represents a valuable tool for developing therapeutic strategies to treat autoimmune demyelinating diseases such as EAE. 相似文献
25.
26.
Justine D. Ceusters Ange A. Mouithys-Mickalad Thierry J. Franck Sandrine Derochette Alain Vanderplasschen Ginette P. Deby-Dupont Didier A. Serteyn 《Mitochondrion》2013,13(5):410-416
Horses are particularly sensitive to excessive inflammatory reaction where myeloperoxidase, a marker of inflammation, may contribute to mitochondrial dysfunctions. This study investigated the interaction between myeloperoxidase and cultured primary equine skeletal myoblasts, particularly its effect on mitochondrial respiration combined or not with anoxia followed by reoxygenation (AR). We showed that active myeloperoxidase entered into the cells, interacted with mitochondria and decreased routine and maximal respirations. When combined with AR, myeloperoxidase caused a further decrease of these respiratory parameters while the leak increased. Our results indicate that myeloperoxidase amplifies the mitochondrial damages initiated by AR phenomenon and alters the mitochondrial function. 相似文献
27.
Kinsley Narainsamy Corinne Cassier-Chauvat Christophe Junot Franck Chauvat 《Metabolomics : Official journal of the Metabolomic Society》2013,9(1):21-32
Cyanobacteria are environmentally important photosynthetic microorganisms attracting a growing attention in various areas of basic and applied researches. To better understand their metabolism, we presently report on the development of a robust and simple protocol for facile extraction and high throughput analysis of the metabolites of the widely-used strain Synechocystis PCC6803 through liquid chromatography coupled to high resolution mass spectrometry (LC/MS). Our analytical method was developed and tested with 102 reference compounds representative of the chemical diversity of polar cell metabolites, and Synechocystis cell extracts spiked with 37 reference compounds. These samples were analyzed with two chromatographic systems, each coupled to a LTQ-Orbitrap mass spectrometer: a liquid chromatographic system equipped with a pentafluorophenylpropyl column (the PFPP-LC/MS system), and an ultra-high performance liquid chromatographic system with a C18-reversed phase column (the C18-UHPLC/MS system). We showed that the PFPP-LC/MS method performs better than the C18-UHPLC/MS method in terms of retention, separation and detection of metabolites. Consequently, we applied the PFPP-LC/MS method to analyze the metabolome of Synechocystis growing under various conditions of light and glucose, which strongly influence cell growth. We found that glucose increases glucose storage (synthesis of glycogen-like polysaccharide) and catabolism (oxidative pentose phosphate pathway and glycolysis), while it decreases the Calvin–Benson cycle that consumes photosynthetic electrons for CO2 assimilation. Depending on light and glucose availabilities, this global metabolic reprogramming can generate an oxidative stress, likely through the recombination of the glucose-spared electrons with the photosynthetic oxygen thereby producing toxic reactive oxygen species. 相似文献
28.
Franck Desmoulin Michel Galinier Charlotte Trouillet Matthieu Berry Clément Delmas Annie Turkieh Pierre Massabuau Heinrich Taegtmeyer Fatima Smih Philippe Rouet 《PloS one》2013,8(4)
Objective
Mortality in heart failure (AHF) remains high, especially during the first days of hospitalization. New prognostic biomarkers may help to optimize treatment. The aim of the study was to determine metabolites that have a high prognostic value.Methods
We conducted a prospective study on a training cohort of AHF patients (n = 126) admitted in the cardiac intensive care unit and assessed survival at 30 days. Venous plasmas collected at admission were used for 1H NMR – based metabonomics analysis. Differences between plasma metabolite profiles allow determination of discriminating metabolites. A cohort of AHF patients was subsequently constituted (n = 74) to validate the findings.Results
Lactate and cholesterol were the major discriminating metabolites predicting 30-day mortality. Mortality was increased in patients with high lactate and low total cholesterol concentrations at admission. Accuracies of lactate, cholesterol concentration and lactate to cholesterol (Lact/Chol) ratio to predict 30-day mortality were evaluated using ROC analysis. The Lact/Chol ratio provided the best accuracy with an AUC of 0.82 (P < 0.0001). The acute physiology and chronic health evaluation (APACHE) II scoring system provided an AUC of 0.76 for predicting 30-day mortality. APACHE II score, Cardiogenic shock (CS) state and Lact/Chol ratio ≥ 0.4 (cutoff value with 82% sensitivity and 64% specificity) were significant independent predictors of 30-day mortality with hazard ratios (HR) of 1.11, 4.77 and 3.59, respectively. In CS patients, the HR of 30-day mortality risk for plasma Lact/Chol ratio ≥ 0.4 was 3.26 compared to a Lact/Chol ratio of < 0.4 (P = 0.018). The predictive power of the Lact/Chol ratio for 30-day mortality outcome was confirmed with the independent validation cohort.Conclusion
This study identifies the plasma Lact/Chol ratio as a useful objective and simple parameter to evaluate short term prognostic and could be integrated into quantitative guidance for decision making in heart failure care. 相似文献29.
Oula Shahin Nicolas Martin-St Paul Serge Rambal Richard Joffre Franck Richard 《Symbiosis (Philadelphia, Pa.)》2013,61(1):1-12
Understanding the factors underlying the distribution of biodiversity is a challenging issue in ecology. Here, we examined the distribution patterns of ectomycorrhizal fungal diversity across the soil profile in three Quercus ilex forests. Contact exploration type strongly dominated at all sites, but was most prevalent in the upper, organic-rich soil layers. At each site, three quarters of the ectomycorrhizal tips and 59 % of taxa were restricted to the ten first centimeters of the soil profile. The relative abundance of the dominant family Russulaceae increased with increasing soil depth. Species composition varied significantly among sites, with most species being rare. Species that occurred in only one of the three sites accounted for 78.9 % of all species, and 57.3 % of species were represented by a single ECM root tip. Our results suggest that (i) rare species at both local and regional scales contribute to the highly diverse fungal assemblages in Mediterranean forests and (ii) multi-sites studies including the whole soil profile are needed to provide comprehensive overviews of the taxonomic and functional diversities of ectomycorrhizal communities. 相似文献
30.
Maud Martin Ilse Geudens Jonathan Bruyr Michael Potente Anouk Bleuart Marielle Lebrun Nicolas Simonis Christophe Deroanne Jean‐Claude Twizere Philippe Soubeyran Paul Peixoto Denis Mottet Veerle Janssens Wolf‐Karsten Hofmann Filip Claes Peter Carmeliet Richard Kettmann Holger Gerhardt Franck Dequiedt 《The EMBO journal》2013,32(18):2491-2503