Publications by authors named "Castaings L"

Manganese (Mn) is essential for plants but is toxic when taken up in excess. To maintain Mn homeostasis, the root Mn transporter natural resistance associated macrophage protein 1 (NRAMP1) cycles from the plasma membrane to endosomes upon phosphorylation. To identify the kinase involved, a split-luciferase screening was carried out between NRAMP1 and kinases of the CIPK family and identified CIPK23 as a partner of NRAMP1.

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Manganese (Mn) is pivotal for plant growth and development but little is known about the processes that control its homeostasis in the cell. A spotlight on the pools of intracellular manganese and their cellular function has recently been gained through the characterization of new Mn transporters. In particular, transporters catalyzing the ins and outs of Mn at the various Golgi membranes have revealed the central role of the Golgi pool of Mn in the synthesis of the cell wall and as a reservoir for the numerous cellular Mn-dependent pathways whose calibration relies on a set of Golgi-resident transporters of the BICAT and NRAMP families.

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STM196, a plant growth-promoting rhizobacterium isolated from roots of oilseed rape, stimulates growth. We have previously shown that the and genes are required for this growth promotion response. Since these genes are members of the family of nitrate transporters, the nitrogen assimilatory pathway could be involved in growth promotion by STM196.

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The NATURAL RESISTANCE-ASSOCIATED MACROPHAGE PROTEIN 1 (NRAMP1) transporter guarantees plant survival of manganese (Mn) deficiency by mediating Mn entry into root cells. Unlike other high-affinity metal transporters, NRAMP1 is only slightly regulated at the transcriptional level. We show here that adequate Mn content in tissues is safeguarded through a tight control of the quantity of NRAMP1 present at the surface of root cells.

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Plants require trace levels of manganese (Mn) for survival, as it is an essential cofactor in oxygen metabolism, especially O production via photosynthesis and the disposal of superoxide radicals. These processes occur in specialized organelles, requiring membrane-bound intracellular transporters to partition Mn between cell compartments. We identified an member of the NRAMP family of divalent metal transporters, NRAMP2, which functions in the intracellular distribution of Mn.

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Article Synopsis
  • Living organisms, including plants, must carefully manage metal levels for proper function, and this process involves metal transporters moving between cell compartments.
  • In developing seedlings, the NRAMP3 and NRAMP4 transporters are crucial for mobilizing iron from storage to help the plant begin photosynthesis.
  • Research shows that the protein AtPH1 helps localize metal transporters like NRAMP1 to their correct places in the cell, and its absence causes iron transport issues, indicating it plays a key regulatory role in metal homeostasis.
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Article Synopsis
  • Iron (Fe) and manganese (Mn) are crucial for plant growth, and in Arabidopsis thaliana, their uptake is primarily managed by high affinity transporters IRT1 and NRAMP1.
  • Mutant plants lacking both transporters displayed severe Fe deficiency symptoms, even when Fe was present in adequate amounts, indicating the importance of these transporters for Fe uptake.
  • The study revealed that NRAMP1 is essential for Fe transport and works alongside IRT1, providing the first evidence of a low affinity Fe uptake system in plants, while also suggesting a role in Mn uptake.
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Purpose: The aim of this study is to compare the accuracy and reliability of spinal curvatures and vertebral rotation data based on patient-specific 3D models created by 3D imaging system or by bi-planar imaging coupled with Moiré-Fringe projections.

Methods And Materials: Sixty-two consecutive patients from a single institution were prospectively included. For each patient, frontal and sagittal calibrated low-dose bi-planar X-rays were performed and coupled simultaneously with an optical Moiré back surface-based technology.

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Despite evolutionary conserved mechanisms to silence transposable element activity, there are drastic differences in the abundance of transposable elements even among closely related plant species. We conducted a de novo assembly for the 375 Mb genome of the perennial model plant, Arabis alpina. Analysing this genome revealed long-lasting and recent transposable element activity predominately driven by Gypsy long terminal repeat retrotransposons, which extended the low-recombining pericentromeres and transformed large formerly euchromatic regions into repeat-rich pericentromeric regions.

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Antisense RNA (asRNA) COOLAIR is expressed at A. thaliana FLOWERING LOCUS C (FLC) in response to winter temperatures. Its contribution to cold-induced silencing of FLC was proposed but its functional and evolutionary significance remain unclear.

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Nitrate is both an important nutrient and a signalling molecule for plants. Although several components of the nitrate signalling pathway have been identified, their hierarchical organization remains unclear. Here we show that the localization of NLP7, a member of the RWP-RK transcription factor family, is regulated by nitrate via a nuclear retention mechanism.

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Nitrogen is an essential macronutrient for plant development and productivity. The adaptation toward changes in nitrogen availability in the soil is crucial for the immobile plant. Nitrate is the primary nitrogen source in temperate climate.

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Higher plants exhibit a variety of different life histories. Annual plants live for less than a year and after flowering produce seeds and senesce. By contrast perennials live for many years, dividing their life cycle into episodes of vegetative growth and flowering.

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Nitrogen (N) is an essential macronutrient for plants. N levels in soil vary widely, and plants have developed strategies to cope with N deficiency. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly understood.

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It is well known that nitrogen (N) and N status can be sensed by plants to regulate their development, physiology, and metabolism. Based on approaches efficiently used for fungi and algae, plant researchers have been trying, but with little success, to elucidate higher plants N signalling for several years. Recently, the use of new strategies such as transcriptomics, comparative reverse genetics, and new forward genetic screens have unravelled some players within the complex plant N signalling network.

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Nitrate is an essential nutrient, and is involved in many adaptive responses of plants, such as localized proliferation of roots, flowering or stomatal movements. How such nitrate-specific mechanisms are regulated at the molecular level is poorly understood. Although the Arabidopsis ANR1 transcription factor appears to control stimulation of lateral root elongation in response to nitrate, no regulators of nitrate assimilation have so far been identified in higher plants.

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Over recent years, an increasing number of patients with intracranial aneurysms are treated by endovascular techniques, which have the advantage of avoiding craniotomy and retraction of cerebral parenchyma, while reducing the postoperative hospital stay. The key concept is that aneurysm is a disease of the arterial wall and that treatment must ideally only concern the vessel. The short-term efficacy of endovascular treatment has been established, especially for the prevention of early rebleeding, but its long-term efficacy has not yet been formally demonstrated due insufficient follow-up.

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Basilar artery occlusions are rare but have a very poor prognosis. Intra-arterial thrombolysis may produce recanalization and better clinical outcome. A short delay between the onset of symptoms and thrombolysis is considered essential for successful recanalization and for the smallest possible risk of haemorrhagic complications.

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Purpose: To evaluate the stability of aneurysm occlusion at follow-up angiography after endovascular treatment (EVT) with detachable coils in intracranial berry aneurysms.

Materials And Methods: A total of 203 berry aneurysms (< 1.5 cm) were treated with EVT.

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Distal aneurysms of the cerebellar arteries are associated with a poor prognosis, as surgery or embolization with GDCs is very difficult. We report our experience with a new therapeutic method involving intraaneurysmal injection of glue. Three aneurysms were catheterized with a flow-guided microcatheter, and glue was slowly injected into the aneurysms.

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Purpose: To establish that intra-arterial fibrinolysis of the ophthalmic artery can still be efficient 8 hours or more after a central retinal artery occlusion.

Material And Methods: Nine to twenty hours (average 12.5 H) after a loss of vision due to a central retinal artery occlusion or the occlusion of its branches, 7 patients were treated by intra-arterial fibrinolysis.

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Basilar aneurysms that are not amenable to standard endovascular treatment via the femoral approach because catheterization is difficult pose a rare but serious problem. We present two cases of basilar tip aneurysms successfully treated by the endovascular route after direct puncture of the right vertebral artery. In both patients, the left vertebral artery was tortuous, small, and irregular, and the ostium of the right vertebral artery was not accessible by the femoral approach.

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We report a case of primary orbital varix treated by embolization with coils after surgical exposure and puncture of the venous ectasia. This method of treatment has the advantage of limiting traumatic dissection and avoiding difficult venous catheterization.

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Purpose: We describe our therapeutic strategy and correlate the anatomic results and clinical outcomes in patients who received immediate fibrinolytic therapy for thromboembolic complications occurring during endovascular treatment of an intracerebral aneurysm.

Methods: The medical records and angiographic examinations of 19 patients were reviewed. All endovascular procedures were performed with the patients under general anesthesia and fully heparinized.

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Purpose: To determine the types of aneurysm that may be treated endovascularly with platinum detachable coils.

Materials And Methods: Two hundred eight patients with 236 intracranial berry aneurysms underwent endovascular coil embolization; 150 patients had subarachnoid hemorrhage at the time of presentation.

Results: Treatment was performed in 182 patients with 203 (86%) aneurysms (86%).

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