scholarly journals Characterization of the eyespot and hematochrome-like granules of Euglena gracilis by scan-free absorbance spectral imaging A(x, y, λ) for quantification of carotenoids within the live cells

2018 ◽  
Author(s):  
Kyohei Yamashita ◽  
Takafumi Yagi ◽  
Takumi Isono ◽  
Yusuke Nishiyama ◽  
Masafumi Hashimoto ◽  
...  
Keyword(s):  
Euglena Gracilis ◽  
Absorption Maximum ◽  
Spectral Imaging ◽  
Basic Research ◽  
Live Cells ◽  
Carotenoid Content ◽  
Characteristic Absorption ◽  
Non Invasive ◽  
Characteristic Absorption Peak

Euglena gracilis is an edible photosynthetic single-cell alga that can synthesize carotenoids. It is highly demanded to establish the technology to select and grow individual cells capable of synthesizing more carotenoids because it contributes to safe and inexpensive production of carotenoids. In the cells of E. gracilis, carotenoids are mainly contained in chloroplasts and eyespots, and typical carotenoids have a characteristic absorption maximum in common. E. gracilis also has an organelle resembling hematochrome, which has an appearance similar to the eyespot and the absorption band spectrally overlapping that of the carotenoid although reportedly it does not contain carotenoids. To discriminate the eyespot and hematochrome-like granules and to investigate the intracellular distribution of carotenoids, scan-free, non-invasive, absorbance spectral imaging A(x, y, λ) microscopy of single live cells was applied. It was demonstrated that this technique is a powerful tool not only for basic research on intracellular structural analysis but also for identifying difference in carotenoid content in individual cells applicable to screening of carotenoid-rich cells. By this technique, it was confirmed that carotenoids exist in chloroplasts and eyespots, and a number of characteristic absorption spectra of pigments observed specific to the eyespot or hematochrome-like granules were identified. In addition, it was found that hematochrome-like granules have a characteristic absorption peak at 620 nm as well as at 676 nm, suggesting that its origin is a component of chloroplast including Chlorophyll a.

scholarly journals Characterization of the eyespot and hematochrome-like granules of Euglena gracilis by scan-free absorbance spectral imaging A(x, y, λ) for quantification of carotenoids within the live cells

2018 ◽  
Author(s):  
Kyohei Yamashita ◽  
Takafumi Yagi ◽  
Takumi Isono ◽  
Yusuke Nishiyama ◽  
Masafumi Hashimoto ◽  
...  
Keyword(s):  
Euglena Gracilis ◽  
Absorption Maximum ◽  
Spectral Imaging ◽  
Basic Research ◽  
Live Cells ◽  
Carotenoid Content ◽  
Characteristic Absorption ◽  
Non Invasive ◽  
Characteristic Absorption Peak

Euglena gracilis is an edible photosynthetic single-cell alga that can synthesize carotenoids. It is highly demanded to establish the technology to select and grow individual cells capable of synthesizing more carotenoids because it contributes to safe and inexpensive production of carotenoids. In the cells of E. gracilis, carotenoids are mainly contained in chloroplasts and eyespots, and typical carotenoids have a characteristic absorption maximum in common. E. gracilis also has an organelle resembling hematochrome, which has an appearance similar to the eyespot and the absorption band spectrally overlapping that of the carotenoid although reportedly it does not contain carotenoids. To discriminate the eyespot and hematochrome-like granules and to investigate the intracellular distribution of carotenoids, scan-free, non-invasive, absorbance spectral imaging A(x, y, λ) microscopy of single live cells was applied. It was demonstrated that this technique is a powerful tool not only for basic research on intracellular structural analysis but also for identifying difference in carotenoid content in individual cells applicable to screening of carotenoid-rich cells. By this technique, it was confirmed that carotenoids exist in chloroplasts and eyespots, and a number of characteristic absorption spectra of pigments observed specific to the eyespot or hematochrome-like granules were identified. In addition, it was found that hematochrome-like granules have a characteristic absorption peak at 620 nm as well as at 676 nm, suggesting that its origin is a component of chloroplast including Chlorophyll a.

scholarly journals Purification and characterization of sheep platelet cyclo-oxygenase Acetylation by aspirin prevents haemin binding to the enzyme

1986 ◽  
Vol 239 (2) ◽  
pp. 371-377 ◽  
Author(s):  
R Boopathy ◽  
A S Balasubramanian
Keyword(s):  
Column Chromatography ◽  
Absorption Maximum ◽  
Metal Chelate ◽  
Arachidic Acid ◽  
Polyacrylamide Gel Electrophoresis ◽  
Neutral Sugar ◽  
Serine Residue ◽  
Purification And Characterization ◽  
Characteristic Absorption

Arachidonate cyclo-oxygenase (prostaglandin synthetase; prostaglandin endoperoxide synthetase; EC 1.14.99.1) was purified from sheep platelets. The purification procedure involved hydrophobic column chromatography using either Ibuprofen-Sepharose, phenyl-Sepharose or arachidic acid-Sepharose as the first step followed by metal-chelate Sepharose and haemin-Sepharose affinity chromatography. The purified enzyme (Mr approximately 65,000) was homogeneous as observed by SDS/polyacrylamide-gel electrophoresis and silver staining. The enzyme was a glycoprotein with mannose as the neutral sugar. Haemin or haemoglobin was essential for activity. The purified enzyme could bind haemin exhibiting a characteristic absorption maximum at 410 nm. The enzyme after metal-chelate column chromatography could undergo acetylation by [acetyl-3H]aspirin. The labelled acetylated enzyme could not bind to haemin-Sepharose, presumably due to acetylation of a serine residue involved in the binding to haemin. The acetylated enzyme also failed to show its characteristic absorption maximum at 410 nm when allowed to bind haemin.

Absorbance spectra of the hematochrome-like granules and eyespot of Euglena gracilis by scan-free absorbance spectral imaging A(x, y, λ) within the live cells

2019 ◽  
Vol 132 (3) ◽  
pp. 431-438 ◽  
Author(s):  
Kyohei Yamashita ◽  
Takafumi Yagi ◽  
Takumi Isono ◽  
Yusuke Nishiyama ◽  
Masafumi Hashimoto ◽  
...  
Keyword(s):  
Euglena Gracilis ◽  
Spectral Imaging ◽  
Live Cells ◽  
Absorbance Spectra

scholarly journals Printed Electrochemical Biosensors: Opportunities and Metrological Challenges

Biosensors ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 166
Author(s):  
Emilio Sardini ◽  
Mauro Serpelloni ◽  
Sarah Tonello
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Basic Research ◽  
Critical Discussion ◽  
Detection Sensitivity ◽  
Live Cells ◽  
Electrochemical Biosensors ◽  
Non Invasive ◽  
Home Based

Printed electrochemical biosensors have recently gained increasing relevance in fields ranging from basic research to home-based point-of-care. Thus, they represent a unique opportunity to enable low-cost, fast, non-invasive and/or continuous monitoring of cells and biomolecules, exploiting their electrical properties. Printing technologies represent powerful tools to combine simpler and more customizable fabrication of biosensors with high resolution, miniaturization and integration with more complex microfluidic and electronics systems. The metrological aspects of those biosensors, such as sensitivity, repeatability and stability, represent very challenging aspects that are required for the assessment of the sensor itself. This review provides an overview of the opportunities of printed electrochemical biosensors in terms of transducing principles, metrological characteristics and the enlargement of the application field. A critical discussion on metrological challenges is then provided, deepening our understanding of the most promising trends in order to overcome them: printed nanostructures to improve the limit of detection, sensitivity and repeatability; printing strategies to improve organic biosensor integration in biological environments; emerging printing methods for non-conventional substrates; microfluidic dispensing to improve repeatability. Finally, an up-to-date analysis of the most recent examples of printed electrochemical biosensors for the main classes of target analytes (live cells, nucleic acids, proteins, metabolites and electrolytes) is reported.

Characterization of a Motile Cellular Domain Arising During the Amoebo-Flagellate Transformation of Physarum Polycephalum

1980 ◽  
Vol 38 ◽  
pp. 552-553
Author(s):  
K.I. Pagh ◽  
M.R. Adelman
Keyword(s):  
Cell Shape ◽  
Physarum Polycephalum ◽  
Slime Mold ◽  
Live Cells ◽  
Cellular Domain

Unicellular amoebae of the slime mold Physarum polycephalum undergo marked changes in cell shape and motility during their conversion into flagellate swimming cells (l). To understand the processes underlying motile activities expressed during the amoebo-flagellate transformation, we have undertaken detailed investigations of the organization, formation and functions of subcellular structures or domains of the cell which are hypothesized to play a role in movement. One focus of our studies is on a structure, termed the “ridge” which appears as a flattened extension of the periphery along the length of transforming cells (Fig. 1). Observations of live cells using Nomarski optics reveal two types of movement in this region:propagation of undulations along the length of the ridge and formation and retraction of filopodial projections from its edge. The differing activities appear to be associated with two characteristic morphologies, illustrated in Fig. 1.

scholarly journals A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
M. Musse ◽  
G. Hajjar ◽  
N. Ali ◽  
B. Billiot ◽  
G. Joly ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Deficit ◽  
Soil Conditions ◽  
Growth Stages ◽  
Dry Matter Content ◽  
Tuber Growth ◽  
Non Invasive ◽  
Potato Plants ◽  
Significant Difference

Abstract Background Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping. Results This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes. Conclusions This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

scholarly journals Current Trends in Non-Invasive Imaging of Interactions in the Liver Tumor Microenvironment Mediated by Tumor Metabolism

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3645
Author(s):  
Isabel Theresa Schobert ◽  
Lynn Jeanette Savic
Keyword(s):  
Tumor Microenvironment ◽  
Liver Cancer ◽  
Cancer Cells ◽  
Imaging Techniques ◽  
Treatment Strategies ◽  
Tumor Metabolism ◽  
Resistance Mechanisms ◽  
Metabolic Reprogramming ◽  
Non Invasive

With the increasing understanding of resistance mechanisms mediated by the metabolic reprogramming in cancer cells, there is a growing clinical interest in imaging technologies that allow for the non-invasive characterization of tumor metabolism and the interactions of cancer cells with the tumor microenvironment (TME) mediated through tumor metabolism. Specifically, tumor glycolysis and subsequent tissue acidosis in the realms of the Warburg effect may promote an immunosuppressive TME, causing a substantial barrier to the clinical efficacy of numerous immuno-oncologic treatments. Thus, imaging the varying individual compositions of the TME may provide a more accurate characterization of the individual tumor. This approach can help to identify the most suitable therapy for each individual patient and design new targeted treatment strategies that disable resistance mechanisms in liver cancer. This review article focuses on non-invasive positron-emission tomography (PET)- and MR-based imaging techniques that aim to visualize the crosstalk between tumor cells and their microenvironment in liver cancer mediated by tumor metabolism.

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