387 research outputs found

    Primary strumal carcinoid tumor of the ovary: A pregnant patient exhibiting severe constipation and CEA elevation

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    ► We present a rare case of a PYY-positive primary strumal carcinoid tumor of the ovary during pregnancy. ► MRI was useful for the preoperative diagnosis, and the prenatal course was uneventful after the operation. ► Colitis due to severe constipation caused by PYY, which is an inhibitor of intestinal mobility, might induce serum CEA elevation

    A Comparative SEM-EDS Elemental Composition of Mud in Coastal Aquaculture Ponds

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    The present study was aimed to understand the comparative abundance and source of elemental constituents in mud of four coastal shrimp farming areas, Vunh Tau (VT), Nha Trang (NT), Da Nang (DN) and Hue (HU) in Viet Nam using SEM-EDS analysis. Mud samples were collected from shrimp farming coastal zones and used for SEM-EDS analysis. Obtained results clearly revealed that all muds were predominately constituted with Si (23.39 \u2013 47.42%), Al (4.5 \u2013 15.9%), Fe (0.59 \u20138.29%) and C (6.56 to 12.55%). Despite that K (3.67%), Al (15.9%), Fe (8.29%) and Ti (0.65%) were distributed at highest percentage in the VT than that of the remaining three stations; Na (3.68%) was prevalent in NT; whereas Mg (1.46%) and Si (47.42) were abundant with elevated percentage in DN as well as C (12.55%), P (3.34%) and S (2.72%) pronounced with maximum percentage in HU. Therefore, it may also be concluded that mud of all shrimp ponds are principally composed with Si, Al, Fe and C as major elemental constituents, whereas remaining other elements are present in low percentage in the mud of shrimp ponds in geochemical profile of Viet Nam. Though it is not possible to ascertain the source of all elements from this study but abundance of Al and Fe in the mud of shrimp ponds are largely influenced by the anthropogenic sources. Moreover, from this study it can be suggested that monitoring of elemental composition and their source using SEM-EDS would be a potential tool for understanding the concentration level towards conserving the coastal environment

    The physiological importance of photosynthetic ferredoxin NADP+ oxidoreductase (FNR) isoforms in wheat

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    Ferredoxin NADP+ oxidoreductase (FNR) enzymes catalyse electron transfer between ferredoxin and NADPH. In plants, a photosynthetic FNR (pFNR) transfers electrons from reduced ferredoxin to NADPH for the final step of linear electron flow, providing reductant for carbon fixation. pFNR is also thought to play important roles in two different mechanisms of cyclic electron flow around photosystem I; and photosynthetic reductant is itself partitioned between competing linear, cyclic, and alternative electron flow pathways. Four pFNR protein isoforms in wheat that display distinct reaction kinetics with leaf-type ferredoxin have previously been identified. It has been suggested that these isoforms may be crucial to the regulation of reductant partition between carbon fixation and other metabolic pathways. Here the 12 cm primary wheat leaf has been used to show that the alternative N-terminal pFNRI and pFNRII protein isoforms have statistically significant differences in response to the physiological parameters of chloroplast maturity, nitrogen regime, and oxidative stress. More specifically, the results obtained suggest that the alternative N-terminal forms of pFNRI have distinct roles in the partitioning of photosynthetic reductant. The role of alternative N-terminal processing of pFNRI is also discussed in terms of its importance for thylakoid targeting. The results suggest that the four pFNR protein isoforms are each present in the chloroplast in phosphorylated and non-phosphorylated states. pFNR isoforms vary in putative phosphorylation responses to physiological parameters, but the physiological significance requires further investigation

    Arabidopsis thaliana PGR7 Encodes a Conserved Chloroplast Protein That Is Necessary for Efficient Photosynthetic Electron Transport

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    A significant fraction of a plant's nuclear genome encodes chloroplast-targeted proteins, many of which are devoted to the assembly and function of the photosynthetic apparatus. Using digital video imaging of chlorophyll fluorescence, we isolated proton gradient regulation 7 (pgr7) as an Arabidopsis thaliana mutant with low nonphotochemical quenching of chlorophyll fluorescence (NPQ). In pgr7, the xanthophyll cycle and the PSBS gene product, previously identified NPQ factors, were still functional, but the efficiency of photosynthetic electron transport was lower than in the wild type. The pgr7 mutant was also smaller in size and had lower chlorophyll content than the wild type in optimal growth conditions. Positional cloning located the pgr7 mutation in the At3g21200 (PGR7) gene, which was predicted to encode a chloroplast protein of unknown function. Chloroplast targeting of PGR7 was confirmed by transient expression of a GFP fusion protein and by stable expression and subcellular localization of an epitope-tagged version of PGR7. Bioinformatic analyses revealed that the PGR7 protein has two domains that are conserved in plants, algae, and bacteria, and the N-terminal domain is predicted to bind a cofactor such as FMN. Thus, we identified PGR7 as a novel, conserved nuclear gene that is necessary for efficient photosynthetic electron transport in chloroplasts of Arabidopsis

    Update on chloroplast research

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    Chloroplasts, the green differentiation form of plastids, are the sites of photosynthesis and other important plant functions. Genetic and genomic technologies have greatly boosted the rate of discovery and functional characterization of chloroplast proteins during the past decade. Indeed, data obtained using high-throughput methodologies, in particular proteomics and transcriptomics, are now routinely used to assign functions to chloroplast proteins. Our knowledge of many chloroplast processes, notably photosynthesis and photorespiration, has reached such an advanced state that biotechnological approaches to crop improvement now seem feasible. Meanwhile, efforts to identify the entire complement of chloroplast proteins and their interactions are progressing rapidly, making the organelle a prime target for systems biology research in plants

    A prolonged run-in period of standard subcutaneous microdialysis ameliorates quality of interstitial glucose signal in patients after major cardiac surgery

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    We evaluated a standard subcutaneous microdialysis technique for glucose monitoring in two critically ill patient populations and tested whether a prolonged run-in period improves the quality of the interstitial glucose signal. 20 surgical patients after major cardiac surgery (APACHE II score: 10.1 ± 3.2) and 10 medical patients with severe sepsis (APACHE II score: 31.1 ± 4.3) were included in this investigation. A microdialysis catheter was inserted in the subcutaneous adipose tissue of the abdominal region. Interstitial fluid and arterial blood were sampled in hourly intervals to analyse glucose concentrations. Subcutaneous adipose tissue glucose was prospectively calibrated to reference arterial blood either at hour 1 or at hour 6. Median absolute relative difference of glucose (MARD), calibrated at hour 6 (6.2 (2.6; 12.4) %) versus hour 1 (9.9 (4.2; 17.9) %) after catheter insertion indicated a significant improvement in signal quality in patients after major cardiac surgery (p < 0.001). Prolonged run-in period revealed no significant improvement in patients with severe sepsis, but the number of extreme deviations from the blood plasma values could be reduced. Improved concurrence of glucose readings via a 6-hour run-in period could only be achieved in patients after major cardiac surgery

    Agrobacterium rhizogenes rolB gene affects photosynthesis and chlorophyll content in transgenic tomato (Solanum lycopersicum L.) plants

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    Insertion of Agrobacterium rhizogenes rolB gene into plant genome affects plant development, hormone balance and defence. However, beside the current research, the overall transcriptional response and gene expression of rolB as a modulator in plant is unknown. Transformed rolB tomato plant (Solanum lycopersicum L.) cultivar Tondino has been used to investigate the differential expression profile. Tomato is a well-known model organism both at the genetic and molecular level, and one of the most important commercial food crops in the world. Through the construction and characterization of a cDNA subtracted library, we have investigated the differential gene expression between transgenic clones of rolB and control tomato and have evaluated genes specifically transcribed in transgenic rolB plants. Among the selected genes, five genes encoding for chlorophyll a/b binding protein, carbonic anhydrase, cytochrome b6/f complex Fe-S subunit, potassium efflux antiporter 3, and chloroplast small heat-shock protein, all involved in chloroplast function, were identified. Measurement of photosynthesis efficiency by the level of three different photosynthetic parameters (Fv/Fm, rETR, NPQ) showed rolB significant increase in non-photochemical quenching and a, b chlorophyll content. Our results point to highlight the role of rolB on plant fitness by improving photosynthesis

    Amino acid sequence variations in Nicotiana CRR4 orthologs determine the species-specific efficiency of RNA editing in plastids

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    In flowering plants, RNA editing is a posttranscriptional process that converts specific C to U in organelle mRNAs. Nicotiana tabacum is an allotetraploid species derived from the progenitors of Nicotiana sylvestris and Nicotiana tomentosiformis. These Nicotiana species have been used as a model for understanding the mechanism and evolution of RNA editing in plastids. In Nicotiana species, the ndhD-1 site is edited to create the translational initiation codon of ndhD that encodes a subunit of the NAD(P)H dehydrogenease (NDH) complex. An analysis of this RNA editing revealed that editing efficiency in N. tomentosiformis is lower (15%) than that in N. tabacum (42%) and N. sylvestris (37%). However, this level of editing is sufficient for accumulating the NDH complex and its activity. The heterogous complementation of Arabidopsis crr4-3 mutant, in which RNA editing of ndhD-1 is completely impaired, with CRR4 orthologous genes derived from Nicotiana species suggested that the reduction in editing efficiency in N. tomentosiformis is caused by amino acid variations accumulating in CRR4
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