368 research outputs found

    Carbon partitioning and export in transgenic Arabidopsis thaliana with altered capacity for sucrose synthesis grown at low temperature: a role for metabolite transporters

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    We investigated the role of metabolite transporters in cold acclimation by comparing the responses of wild-type (WT) Arabidopsis thaliana (Heynh.) with that of transgenic plants over-expressing sucrose-phosphate synthase (SPSox) or with that of antisense repression of cytosolic fructose-1,6-bisphosphatase (FBPas). Plants were grown at 23 degrees C and then shifted to 5 degrees C. We compared the leaves shifted to 5 degrees C for 3 and 10 d with new leaves that developed at 5 degrees C with control leaves on plants at 23 degrees C. At 23 degrees C, ectopic expression of SPS resulted in 30% more carbon being fixed per day and an increase in sucrose export from source leaves. This increase in fixation and export was supported by increased expression of the plastidic triose-phosphate transporter AtTPT and, to a lesser extent, the high-affinity Suc transporter AtSUC1. The improved photosynthetic performance of the SPSox plants was maintained after they were shifted to 5 degrees C and this was associated with further increases in AtSUC1 expression but with a strong repression of AtTPT mRNA abundance. Similar responses were shown by WT plants during acclimation to low temperature and this response was attenuated in the low sucrose producing FBPas plants. These data suggest that a key element in recovering flux through carbohydrate metabolism in the cold is to control the partitioning of metabolites between the chloroplast and the cytosol, and Arabidopsis modulates the expression of AtTPT to maintain balanced carbon flow. Arabidopsis also up-regulates the expression of AtSUC1, and to lesser extent AtSUC2, as down-stream components facilitate sucrose transport in leaves that develop at low temperatures.info:eu-repo/semantics/publishedVersio

    API 616 Gas Turbine

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    Intravitreal ranibizumab versus isovolemic hemodilution in the treatment of macular edema secondary to central retinal vein occlusion: Twelve-month results of a prospective, randomized, multicenter trial

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    PURPOSE This is a prospective, randomized, multicenter, investigator-initiated trial to evaluate the 12-month effectiveness of isovolemic hemodilution (IH) with prompt versus deferred intravitreal injections (IVI) of ranibizumab 0.5 mg for the treatment of macular edema secondary to early central retinal vein occlusion (CRVO). METHODS Eyes with macular edema due to CRVO having occurred not more than 8 weeks previously received either monthly ranibizumab IVI in combination with IH (group I, n = 28) or IH alone (group II, n = 30). From month 2 to 12, the patients in both groups could be treated with monthly intravitreal ranibizumab. The main outcome variables were gain of visual acuity and the course of central retinal thickness as measured with optical coherence tomography. RESULTS At 12 months, eyes in group I on average gained +28.1 (Ā±19.3) letters compared to +25.2 (Ā±20.9) letters in group II (p = 0.326). This result was achieved with significantly fewer injections in group II. Additionally, 30% of the eyes in group II did not need ranibizumab IVI during the 12 months of the trial. CONCLUSION Ranibizumab IVI in addition to IH proved to be highly effective in increasing visual acuity and reducing macular edema secondary to CRVO. Initial IH in early CRVO may be a first treatment option in patients anxious about IVI

    Retrospective, observational study in patients receiving a dexamethasone intravitreal implant 0.7 mg for macular oedema secondary to retinal vein occlusion

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    PURPOSE To retrospectively evaluate the re-injection interval, efficacy and safety of dexamethasone (DEX) intravitreal implant 0.7 mg in the treatment of macular oedema (ME) due to retinal vein occlusion (RVO) in Germany in 2009-2012. METHODS Retrospective, multicentre, anonymised observational study of data collected from the first DEX implant 0.7 mg injection through 3-6 months following the last injection. Data were included if the patient was \textgreater18 years old, had a diagnosis of ME secondary to branch or central RVO, and received at least 2 DEX implant 0.7 mg injections during routine practice. RESULTS Data from 87 patients were analysed. Mean time to re-injection between first and second treatments was 5.03 months in the total RVO population, and 5.46 and 4.52 months for the branch and central RVO subpopulations, respectively. An intraocular pressure increase of \textgreater25 mm Hg was recorded in 20% of patients, and 34% of patients began treatment with anti-glaucoma medication, but surgery was not needed for this condition. CONCLUSIONS DEX implant 0.7 mg was found to be well tolerated and effective with repeat treatments in clinical practice

    Manifestations of intraocular inflammation over time in patients on brolucizumab for neovascular AMD

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    Purpose To describe the adverse events associated with brolucizumab, in particular the sequence of intraocular inflammation (IOI), retinal vasculitis (RV), and/or retinal vascular occlusion (RO).Methods This was an unmasked post hoc analysis of the randomized HAWK/HARRIER clinical trials. Patients with neovascular AMD in the brolucizumab arms of the trials were included. IOI-related adverse events reported by study investigators were analyzed to determine early signs and the time course of IOI-related adverse events, using a subgroup of patients with definite/probable IOI cases identified in an independent unmasked post hoc review by an external safety review committee. A limited literature review on MI following anti-VEGF therapy was also conducted.Results Among 50 patients with definite/probable IOI cases identified by the safety review committee, 12 had RV or RO adverse events reported by the investigators. For 6 of 12, IOI (other than RV) was reported before RV or RO. The duration from the first IOI adverse event to the first RV or RO adverse event ranged from 16 to 171 days for 5 patients and was 553 days for 1 patient. Four of the 6 patients received >= 1 brolucizumab injection on or after the date of the first IOI adverse event and before the first RV or RO adverse event.Conclusions IOI may precede RV or RO in some patients treated with brolucizumab.Ophthalmic researc

    The Therapeutic Effects of Bevacizumab in Patients with Polypoidal Choroidal Vasculopathy

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    A proper description of the biosynthesis of fungal Ī²-lactam antibiotics requires detailed knowledge of the cell biology of the producing organisms. This involves a delineation of the compartmentalization of the biosynthetic pathways, and of the consequential transport steps across the cell-boundary plasma membrane and across organellar membranes. Of the enzymes of the penicillin biosynthetic pathway in Penicillium chrysogenum and Aspergillus nidulans, Ī“-(L-Ī±-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) and isopenicillin N synthase (IPNS) probably have a cytosolic location. Acyl-coenzyme A:isopenicillin N acyltransferase (IAT) is located in microbodies. Of the two enzymes that may be involved in activation of the side chain, acetyl-coenzyme A synthetase (ACS) is located in the cytosol, and phenylacetyl-coenzyme A ligase (PCL) is probably located in the microbody. All enzymes of the cephalosporin biosynthesis pathway in Cephalosporium acremonium probably have a cytosolic location. The vacuole may play an ancillary role in the supply of precursor amino acids, and in the storage of intermediates. The distribution of precursors, intermediates, end- and side-products, the transport of nutrients, precursors, intermediates and products across the plasma membrane, and the transport of small solutes across organellar membranes, is discussed. The relevance of compartmentalization is considered against the background of recent biotechnological innovations of fungal Ī²-lactam biosynthesis pathways.
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