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Bioanalytical Applications of Real-Time ATP Imaging Via Bioluminescence  

Energy Technology Data Exchange (ETDEWEB)

The research discussed within involves the development of novel applications of real-time imaging of adenosine 5'-triphosphate (ATP). ATP was detected via bioluminescence and the firefly luciferase-catalyzed reaction of ATP and luciferin. The use of a microscope and an imaging detector allowed for spatially resolved quantitation of ATP release. Employing this method, applications in both biological and chemical systems were developed. First, the mechanism by which the compound 48/80 induces release of ATP from human umbilical vein endothelial cells (HUVECs) was investigated. Numerous enzyme activators and inhibitors were utilized to probe the second messenger systems involved in release. Compound 48/80 activated a G{sub q}-type protein to initiate ATP release from HUVECs. Ca{sup 2+} imaging along with ATP imaging revealed that activation of phospholipase C and induction of intracellular Ca{sup 2+} signaling were necessary for release of ATP. Furthermore, activation of protein kinase C inhibited the activity of phospholipase C and thus decreased the magnitude of ATP release. This novel release mechanism was compared to the existing theories of extracellular release of ATP. Bioluminescence imaging was also employed to examine the role of ATP in the field of neuroscience. The central nervous system (CNS) was dissected from the freshwater snail Lymnaea stagnalis. Electrophysiological experiments demonstrated that the neurons of the Lymnaea were not damaged by any of the components of the imaging solution. ATP was continuously released by the ganglia of the CNS for over eight hours and varied from ganglion to ganglion and within individual ganglia. Addition of the neurotransmitters K{sup +} and serotonin increased release of ATP in certain regions of the Lymnaea CNS. Finally, the ATP imaging technique was investigated for the study of drug release systems. MCM-41-type mesoporous nanospheres were loaded with ATP and end-capped with mercaptoethanol functionalized CdS monocrystals. Aggregates of nanospheres were bathed in imaging solution, and ATP bioluminescence was monitored to investigated the release kinetics of the nanosphere drug delivery systems. Addition of disulfide bond-cleaving molecules induced uncapping of the nanospheres and subsequently, the release of ATP. Increasing the concentration of the uncapping molecule decreased the temporal maximum and increased the magnitude of release of encapsulated ATP from the nanospheres. Furthermore, the release kinetics from the nanospheres varied with the size of the particle aggregates.

Jason Alan Gruenhagen

2003-12-12

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Timing of Imaging after D-Luciferin Injection Affects the Longitudinal Assessment of Tumor Growth Using In Vivo Bioluminescence Imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The peak signal or the signal at a predetermined, fixed time point after D-luciferin injection may be used for the quantitative analysis of in vivo bioluminescence imaging. We repeatedly performed sequential bioluminescence imaging after subcutaneous injection of D-luciferin in mice bearing subcutaneous tumors. The peak time in each measurement became shorter early after cell inoculation, presumably due to gradual establishment of intratumoral vasculature, and reached a plateau of about 10 mi...

Yusuke Inoue; Shigeru Kiryu; Makoto Watanabe; Arinobu Tojo; Kuni Ohtomo

2010-01-01

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Timing of Imaging after D-Luciferin Injection Affects the Longitudinal Assessment of Tumor Growth Using In Vivo Bioluminescence Imaging  

Directory of Open Access Journals (Sweden)

Full Text Available The peak signal or the signal at a predetermined, fixed time point after D-luciferin injection may be used for the quantitative analysis of in vivo bioluminescence imaging. We repeatedly performed sequential bioluminescence imaging after subcutaneous injection of D-luciferin in mice bearing subcutaneous tumors. The peak time in each measurement became shorter early after cell inoculation, presumably due to gradual establishment of intratumoral vasculature, and reached a plateau of about 10 min on day 10. Although the correlation between the signal at a fixed time point and the peak signal was high, the signal at 5 or 10 min normalized for the peak signal was lower for earlier days, which caused overestimation of tumor growth. The time course of the signals after D-luciferin injection may vary with time after cell inoculation, and this variation should be considered when determining the imaging protocol for quantitative bioluminescence tumor monitoring.

Yusuke Inoue

2010-01-01

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BIOLUMINESCENCE IMAGING: PROGRESS AND APPLICATIONS  

Science.gov (United States)

Application of bioluminescence imaging has grown tremendously in the past decade and has significantly contributed to the core conceptual advances in biomedical research. This technology provides valuable means for monitoring of different biological processes for immunology, oncology, virology and neuroscience. In this review, we will discuss current trends in bioluminescence and its application in different fields with emphasis on cancer research. PMID:21788092

Badr, Christian E.; Tannous, Bakhos A.

2015-01-01

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Bioluminescent imaging of bacteria during mouse infection.  

Science.gov (United States)

Diagnostic imaging is a powerful tool that has recently been applied towards the study of infectious diseases. Optical imaging of bioluminescently labeled bacteria in infected animals allows for real-time analysis of bacterial proliferation and dissemination during infection without sacrificing the animal. Imaging also allows for tracking of disease progression in an individual subject over time, has the potential to reveal previously overlooked sites of infection, and reduces the number of research animals used in pathogenesis studies. Here, we describe the use of a deep-cooled CCD camera imager to record light emitted from bacteria during infection. We also describe the process of correlating bioluminescence to bacterial numbers by ex vivo imaging of necropsied tissues. Together these techniques can be used to estimate bacterial burdens in host tissues both in vivo and ex vivo using bioluminescent imaging. PMID:24166377

Warawa, Jonathan M; Lawrenz, Matthew B

2014-01-01

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Bioluminescence imaging characteristics and application  

International Nuclear Information System (INIS)

Bioluminescence imaging (BLI) by luciferase gene marked cells or DNA, in the presence of ATP and oxygen, catalytic oxidation reaction of fluorescein luminescence. So that it can directly monitor in vivo cell activity and gene behavior. In this paper, by comparing the BLI and MRI, PET, radiography of the similarities and differences, as well as about their cancer, stem cells and immune cells transportation, apoptosis and other aspects of the application, in order to better provide the basis for promoting the application of BLI. (authors)

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Noninvasive Bioluminescence Imaging in Small Animals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There has been a rapid growth of bioluminescence imaging applications in small animal models in recent years, propelled by the availability of instruments, analysis software, reagents, and creative approaches to apply the technology in molecular imaging. Advantages include the sensitivity of the technique as well as its efficiency, relatively low cost, and versatility. Bioluminescence imaging is accomplished by sensitive detection of light emitted following chemical reaction of the luciferase...

Zinn, Kurt R.; Chaudhuri, Tandra R.; Szafran, April Adams; O’quinn, Darrell; Weaver, Casey; Dugger, Kari; Lamar, Dale; Kesterson, Robert A.; Wang, Xiangdong; Frank, Stuart J.

2008-01-01

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Bioluminescent imaging of Trypanosoma cruzi infection in Rhodnius prolixus  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Usually the analysis of the various developmental stages of Trypanosoma cruzi in the experimentally infected vertebrate and invertebrate hosts is based on the morphological observations of tissue fragments from animals and insects. The development of techniques that allow the imaging of animals infected with parasites expressing luciferase open up possibilities to follow the fate of bioluminescent parasites in infected vectors. Methods D-luciferin (60 ?g was injected into the hemocoel of the whole insect before bioluminescence acquisition. In dissected insects, the whole gut was incubated with D-luciferin in PBS (300 ?g/ml for ex vivo bioluminescence acquisition in the IVIS® Imaging System, Xenogen. Results Herein, we describe the results obtained with the luciferase gene integrated into the genome of the Dm28c clone of T. cruzi, and the use of these parasites to follow, in real time, the infection of the insect vector Rhodnius prolixus, by a non- invasive method. The insects were evaluated by in vivo bioluminescent imaging on the feeding day, and on the 7 th, 14 th, 21 st and 28 th days after feeding. To corroborate the bioluminescent imaging made in vivo, and investigate the digestive tract region, the insects were dissected. The bioluminescence emitted was proportional to the number of protozoans in regions of the gut. The same digestive tracts were also macerated to count the parasites in distinct morphological stages with an optical microscope, and for bioluminescence acquisition in a microplate using the IVIS® Imaging System. A positive correlation of parasite numbers and bioluminescence in the microplate was obtained. Conclusions This is the first report of bioluminescent imaging in Rhodnius prolixus infected with trypomastigotes of the Dm28c-luc stable strain, expressing firefly luciferase. In spite of the distribution limitations of the substrate (D-luciferin in the insect body, longitudinal evaluation of infected insects by bioluminescent imaging is a valuable tool. Bioluminescent imaging of the digestive tract infected with Dm28c-luc is highly sensitive and accurate method to track the fate of the parasite in the vector, in the crop, intestine and rectum. This methodology is useful to gain a better understanding of the parasite – insect vector interactions.

Henriques Cristina

2012-09-01

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Quantitative bioluminescence imaging of mouse tumor models.  

Science.gov (United States)

Bioluminescence imaging (BLI) has become an essential technique for preclinical evaluation of anticancer therapeutics and provides sensitive and quantitative measurements of tumor burden in experimental cancer models. For light generation, a vector encoding firefly luciferase is introduced into human cancer cells that are grown as tumor xenografts in immunocompromised hosts, and the enzyme substrate luciferin is injected into the host. Alternatively, the reporter gene can be expressed in genetically engineered mouse models to determine the onset and progression of disease. In addition to expression of an ectopic luciferase enzyme, bioluminescence requires oxygen and ATP, thus only viable luciferase-expressing cells or tissues are capable of producing bioluminescence signals. Here, we summarize a BLI protocol that takes advantage of advances in hardware, especially the cooled charge-coupled device camera, to enable detection of bioluminescence in living animals with high sensitivity and a large dynamic range. PMID:25561617

Tseng, Jen-Chieh; Kung, Andrew L

2015-01-01

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Comparison of image restoration methods for bioluminescence imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioluminescence imaging is a recent modality to visualize biological effects more especially for small animals. However the acquired images are degraded by diffusion and absorption phenomena from the tissue and by the acquisition system itself. In this paper, we use restoration methods to enhance the quality of bioluminescence images. We propose a model for image formation and an experimental determination of the PSF (Point Spread Function). Several methods of restoration are compared on test...

Akkoul, Smai?l; Le?de?e, Roger; Leconge, Remy; Le?ger, Christophe; Harba, Rachid; Pesnel, Sabrina; Lerondel, Ste?phanie; Lepape, Alain

2008-01-01

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Bioluminescence in vivo imaging of autoimmune encephalomyelitis predicts disease  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Experimental autoimmune encephalomyelitis is a widely used animal model to understand not only multiple sclerosis but also basic principles of immunity. The disease is scored typically by observing signs of paralysis, which do not always correspond with pathological changes. Methods Experimental autoimmune encephalomyelitis was induced in transgenic mice expressing an injury responsive luciferase reporter in astrocytes (GFAP-luc. Bioluminescence in the brain and spinal cord was measured non-invasively in living mice. Mice were sacrificed at different time points to evaluate clinical and pathological changes. The correlation between bioluminescence and clinical and pathological EAE was statistically analyzed by Pearson correlation analysis. Results Bioluminescence from the brain and spinal cord correlates strongly with severity of clinical disease and a number of pathological changes in the brain in EAE. Bioluminescence at early time points also predicts severity of disease. Conclusion These results highlight the potential use of bioluminescence imaging to monitor neuroinflammation for rapid drug screening and immunological studies in EAE and suggest that similar approaches could be applied to other animal models of autoimmune and inflammatory disorders.

Steinman Lawrence

2008-02-01

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Bioluminescent system for dynamic imaging of cell and animal behavior  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

Hara-Miyauchi, Chikako [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Tsuji, Osahiko [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Hanyu, Aki [Division of Biochemistry, The Cancer Institute of the Japanese Foundation for Cancer Research, Tokyo 135-8550 (Japan); Okada, Seiji [Department of Advanced Medical Initiatives, Faculty of Medical Sciences, Kyushu University, Fukuoka 812-8582 (Japan); Yasuda, Akimasa [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Fukano, Takashi [Laboratory for Cell Function Dynamics, Brain Science Institute, RIKEN, Saitama 351-0198 (Japan); Akazawa, Chihiro [Department of Biophysics and Biochemistry, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510 (Japan); Nakamura, Masaya [Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo 160-8582 (Japan); Imamura, Takeshi [Department of Molecular Medicine for Pathogenesis, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295 (Japan); Core Research for Evolutional Science and Technology, The Japan Science and Technology Corporation, Tokyo 135-8550 (Japan); Matsuzaki, Yumi [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Okano, Hirotaka James, E-mail: hjokano@jikei.ac.jp [Department of Physiology, Keio University School of Medicine, Tokyo 160-8582 (Japan); Division of Regenerative Medicine Jikei University School of Medicine, Tokyo 150-8461 (Japan); and others

2012-03-09

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Bioluminescent system for dynamic imaging of cell and animal behavior  

International Nuclear Information System (INIS)

Highlights: ? We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. ? ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. ? ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. ? ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

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Dynamic bioluminescence imaging for quantitative tumour burden assessment using IV or IP administration of d-luciferin: effect on intensity, time kinetics and repeatability of photon emission  

International Nuclear Information System (INIS)

In vivo bioluminescence imaging (BLI) is a promising technique for non-invasive tumour imaging. d-luciferin can be administrated intraperitonealy or intravenously. This will influence its availability and, therefore, the bioluminescent signal. The aim of this study is to compare the repeatability of BLI measurement after IV versus IP administration of d-luciferin and assess the correlation between photon emission and histological cell count both in vitro and in vivo. Fluc-positive R1M cells were subcutaneously inoculated in nu/nu mice. Dynamic BLI was performed after IV or IP administration of d-luciferin. Maximal photon emission (PEmax) was calculated. For repeatability assessment, every acquisition was repeated after 4 h and analysed using Bland-Altman method. A second group of animals was serially imaged, alternating IV and IP administration up to 21 days. When mice were killed, PEmax after IV administration was correlated with histological cell number. The coefficients of repeatability were 80.2% (IV) versus 95.0% (IP). Time-to-peak is shorter, and its variance lower for IV (p max was 5.6 times higher for IV. A trend was observed towards lower photon emission per cell in larger tumours. IV administration offers better repeatability and better sensitivity when compared to IP. In larger tumours, multiple factors may contribute to underestimation of tumour burden. It might, therefore, be beneficial to test novel therapeutore, be beneficial to test novel therapeutics on small tumours to enable an accurate evaluation of tumour burden. (orig.)

15

Bioluminescence imaging of myeloperoxidase activity in vivo.  

Science.gov (United States)

The myeloperoxidase (MPO) system of activated phagocytes is central to normal host defense mechanisms, and dysregulated MPO contributes to the pathogenesis of inflammatory disease states ranging from atherosclerosis to cancer. Here we show that upon systemic administration, the small molecule luminol enables noninvasive bioluminescence imaging (BLI) of MPO activity in vivo. Luminol-BLI allowed quantitative longitudinal monitoring of MPO activity in animal models of acute dermatitis, mixed allergic contact hypersensitivity, focal arthritis and spontaneous large granular lymphocytic tumors. Bioluminescence colocalized with histological sites of inflammation and was totally abolished in gene-deleted Mpo(-/-) mice, despite massive tissue infiltration of neutrophils and activated eosinophils, indicating that eosinophil peroxidase did not contribute to luminol-BLI in vivo. Thus, luminol-BLI provides a noninvasive, specific and highly sensitive optical readout of phagocyte-mediated MPO activity in vivo and may enable new diagnostic applications in a wide range of acute and chronic inflammatory conditions. PMID:19305414

Gross, Shimon; Gammon, Seth T; Moss, Britney L; Rauch, Daniel; Harding, John; Heinecke, Jay W; Ratner, Lee; Piwnica-Worms, David

2009-04-01

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In Vivo Bioluminescence Imaging of the Murine Pathogen Citrobacter rodentium  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Citrobacter rodentium is a natural mouse pathogen related to enteropathogenic and enterohemorrhagic Escherichia coli. We have previously utilized bioluminescence imaging (BLI) to determine the in vivo colonization dynamics of C. rodentium. However, due to the oxygen requirement of the bioluminescence system and the colonic localization of C. rodentium, in vivo localization studies were performed using harvested organs. Here, we report the detection of bioluminescent C. rodentium and commensal...

Wiles, Siouxsie; Pickard, Karen M.; Peng, Katian; Macdonald, Thomas T.; Frankel, Gad

2006-01-01

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Dynamic bioluminescence imaging for quantitative tumour burden assessment using IV or IP administration of d-luciferin: effect on intensity, time kinetics and repeatability of photon emission  

Energy Technology Data Exchange (ETDEWEB)

In vivo bioluminescence imaging (BLI) is a promising technique for non-invasive tumour imaging. d-luciferin can be administrated intraperitonealy or intravenously. This will influence its availability and, therefore, the bioluminescent signal. The aim of this study is to compare the repeatability of BLI measurement after IV versus IP administration of d-luciferin and assess the correlation between photon emission and histological cell count both in vitro and in vivo. Fluc-positive R1M cells were subcutaneously inoculated in nu/nu mice. Dynamic BLI was performed after IV or IP administration of d-luciferin. Maximal photon emission (PE{sub max}) was calculated. For repeatability assessment, every acquisition was repeated after 4 h and analysed using Bland-Altman method. A second group of animals was serially imaged, alternating IV and IP administration up to 21 days. When mice were killed, PE{sub max} after IV administration was correlated with histological cell number. The coefficients of repeatability were 80.2% (IV) versus 95.0% (IP). Time-to-peak is shorter, and its variance lower for IV (p < 0.0001). PE{sub max} was 5.6 times higher for IV. A trend was observed towards lower photon emission per cell in larger tumours. IV administration offers better repeatability and better sensitivity when compared to IP. In larger tumours, multiple factors may contribute to underestimation of tumour burden. It might, therefore, be beneficial to test novel therapeutics on small tumours to enable an accurate evaluation of tumour burden. (orig.)

Keyaerts, Marleen; Vanhove, Chris; Caveliers, Vicky; Bossuyt, Axel; Lahoutte, Tony [Vrije Universiteit Brussel (VUB), In Vivo Cellular and Molecular Imaging (ICMI) Laboratory, Brussels (Belgium); University Hospital Brussels (UZ-Brussel), Department of Nuclear Medicine, Brussels (Belgium); Verschueren, Jacob [University of Antwerp, Bio-Imaging lab, Department of Biomedical Sciences, Antwerp (Belgium); Bos, Tomas J. [Vrije Universiteit Brussel (VUB), Department of Haematology and Immunology, Brussels (Belgium); Tchouate-Gainkam, Lea O.; Peleman, Cindy [Vrije Universiteit Brussel (VUB), In Vivo Cellular and Molecular Imaging (ICMI) Laboratory, Brussels (Belgium); Breckpot, Karine [Vrije Universiteit Brussel (VUB), Laboratory of Molecular and Cellular Therapy, Department of Physiology and Immunology, Brussels (Belgium)

2008-05-15

18

Bioluminescence.  

Science.gov (United States)

Describes bioluminescence and the chemistry of how it occurs. Presents information for conducting the following classroom activities: (1) firefly mimic; (2) modeling deep-sea fish; (3) sea fireflies; and (4) the chemistry of light. (PR)

Jones, M. Gail

1993-01-01

19

Filtering and deconvolution for bioluminescence imaging of small animals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis is devoted to the analysis of bioluminescence images applied to the small animal. This kind of imaging modality is used in cancerology studies. Nevertheless, some problems are related to the diffusion and the absorption of the tissues of the light of internal bioluminescent sources. In addition, system noise and the cosmic rays noise are present. This influences the quality of the images and makes it difficult to analyze. The purpose of this thesis is to overcome these disturbing ...

Akkoul, Smai?l

2010-01-01

20

Biosensing and Imaging Based on Bioluminescence Resonance Energy Transfer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioluminescence resonance energy transfer (BRET) operates with biochemical energy generated by bioluminescent proteins to excite fluorophores and offers additional advantages over fluorescence energy transfer (FRET) for in vivo imaging and biosensing. While fluorescent proteins are frequently used as BRET acceptors, both small molecule dyes and nanoparticles can also serve as acceptor fluorophores. Semiconductor fluorescent nanocrystals or quantum dots (QDs) are particularly well-suited for u...

Xia, Zuyong; Rao, Jianghong

2009-01-01

 
 
 
 
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Bioluminescence tomography improves quantitative accuracy for pre-clinical imaging  

Science.gov (United States)

A study is presented that demonstrates that bioluminescence tomography can reconstruct accurate 3D images of internal light sources placed at a range of depths within a physical phantom and that it provides more reliable quantitative data than standard bioluminescence imaging. Specifically, it is shown that when imaging sources at depths ranging from 5 to 15mm, estimates of total source strength are stable to within +/-11% using tomography whilst values deduced by traditional methods vary 10-fold. Additionally, the tomographic approach correctly localises sources to within 1.5mm error in all cases considered.

Guggenheim, James A.; Basevi, Hector R. A.; Styles, Iain B.; Frampton, Jon; Dehghani, Hamid

2013-06-01

22

Filtering and deconvolution for bioluminescence imaging of small animals  

International Nuclear Information System (INIS)

This thesis is devoted to analysis of bioluminescence images applied to the small animal. This kind of imaging modality is used in cancerology studies. Nevertheless, some problems are related to the diffusion and the absorption of the tissues of the light of internal bioluminescent sources. In addition, system noise and the cosmic rays noise are present. This influences the quality of the images and makes it difficult to analyze. The purpose of this thesis is to overcome these disturbing effects. We first have proposed an image formation model for the bioluminescence images. The processing chain is constituted by a filtering stage followed by a deconvolution stage. We have proposed a new median filter to suppress the random value impulsive noise which corrupts the acquired images; this filter represents the first block of the proposed chain. For the deconvolution stage, we have performed a comparative study of various deconvolution algorithms. It allowed us to choose a blind deconvolution algorithm initialized with the estimated point spread function of the acquisition system. At first, we have validated our global approach by comparing our obtained results with the ground truth. Through various clinical tests, we have shown that the processing chain allows a significant improvement of the spatial resolution and a better distinction of very close tumor sources, what represents considerable contribution for the users of bioluminescence images. (author)

23

Near-infrared fluorescence imaging as an alternative to bioluminescent bacteria to monitor biomaterial-associated infections.  

Science.gov (United States)

Biomaterial-associated infection is one of the most common complications related to the implantation of any biomedical device. Several in vivo imaging platforms have emerged as powerful diagnostic tools to longitudinally monitor biomaterial-associated infections in small animal models. In this study, we directly compared two imaging approaches: bacteria engineered to produce luciferase to generate bioluminescence and reactive oxygen species (ROS) imaging of the inflammatory response associated with the infected implant. We performed longitudinal imaging of bioluminescence associated with bacteria strains expressing plasmid-integrated luciferase driven by different promoters or a strain with the luciferase gene integrated into the chromosome. These luminescent strains provided an adequate signal for acute (0-4 days) monitoring of the infection, but the bioluminescence signal decreased over time and leveled off at 7 days post-implantation. This loss in the bioluminescence signal was attributed to changes in the metabolic activity of the bacteria. In contrast, near-infrared fluorescence imaging of ROS associated with inflammation to the implant provided sensitive and dose-dependent signals of biomaterial-associated bacteria. ROS imaging exhibited higher sensitivity than the bioluminescence imaging and was independent of the bacteria strain. Near-infrared fluorescence imaging of inflammatory responses represents a powerful alternative to bioluminescence imaging for monitoring biomaterial-associated bacterial infections. PMID:24632360

Dinjaski, Nina; Suri, Shalu; Valle, Jaione; Lehman, Susan M; Lasa, Iñigo; Prieto, María Auxiliadora; García, Andrés J

2014-07-01

24

Space application research of EMCCDs for bioluminescence imaging  

Science.gov (United States)

The detection of bioluminescense is widely used on the ground, while the detection of bioluminescence in space is still at the stage of detecting bright bioluminescense. With the rapid development of research in Space Life Sciences, it will be necessary to develop a detection technology to detect weak bioluminescense. Compared to other low-light detection techniques for ground, there are more advantages of EMCCDs for space application. Build a space bioluminescence imaging detection system, analysis the feasibility and capability of its will be significant. Co-Author:Xie Zongbao,Zheng Weibo

Zhang, Tao

25

Combined magnetic resonance and bioluminescence imaging of live mice.  

Science.gov (United States)

We perform combined magnetic resonance and bioluminescence imaging of live mice for the purpose of improving the accuracy of bioluminescence tomography. The imaging is performed on three live nude mice in which tritium-powered light sources are surgically implanted. High-resolution magnetic resonance images and multispectral, multiview bioluminescence images are acquired in the same session. An anatomical model is constructed by segmenting the magnetic resonance images for all major tissues. The model is subsequently registered with nonlinear transformations to the 3-D light exittance (exiting intensity) surface map generated from the luminescence images. A Monte Carlo algorithm, along with a set of tissue optical properties obtained from in vivo measurements, is used to solve the forward problem. The measured and simulated light exittance images are found to differ by a factor of up to 2. The greatest cause of this moderate discrepancy is traced to the small errors in source positioning, and to a lesser extent to the optical properties used for the tissues. Discarding the anatomy and using a homogeneous model leads to a marginally worse agreement between the simulated and measured data. PMID:17614726

Allard, Mathieu; Côté, Daniel; Davidson, Lorinda; Dazai, Jun; Henkelman, R Mark

2007-01-01

26

A synthetic luciferin improves bioluminescence imaging in live mice  

Science.gov (United States)

Firefly luciferase is the most widely used optical reporter for noninvasive bioluminescence imaging (BLI) in rodents. BLI relies on the ability of the injected luciferase substrate D-luciferin to access luciferase-expressing cells and tissues within the animal. Here we show that injection of mice with a synthetic luciferin, CycLuc1, improves BLI from existing luciferase reporters and enables imaging in the brain that could not be achieved with D-luciferin. PMID:24509630

Evans, Melanie S.; Chaurette, Joanna P.; Adams, Spencer T.; Reddy, Gadarla R.; Paley, Miranda A.; Aronin, Neil; Prescher, Jennifer A.; Miller, Stephen C.

2014-01-01

27

Development of Quantification Method for Bioluminescence Imaging  

Energy Technology Data Exchange (ETDEWEB)

Optical molecular luminescence imaging is widely used for detection and imaging of bio-photons emitted by luminescent luciferase activation. The measured photons in this method provide the degree of molecular alteration or cell numbers with the advantage of high signal-to-noise ratio. To extract useful information from the measured results, the analysis based on a proper quantification method is necessary. In this research, we propose a quantification method presenting linear response of measured light signal to measurement time. We detected the luminescence signal by using lab-made optical imaging equipment of animal light imaging system (ALIS) and different two kinds of light sources. One is three bacterial light-emitting sources containing different number of bacteria. The other is three different non-bacterial light sources emitting very weak light. By using the concept of the candela and the flux, we could derive simplified linear quantification formula. After experimentally measuring light intensity, the data was processed with the proposed quantification function. We could obtain linear response of photon counts to measurement time by applying the pre-determined quantification function. The ratio of the re-calculated photon counts and measurement time present a constant value although different light source was applied. The quantification function for linear response could be applicable to the standard quantification process. The proposed method could be used for the exact quantitative analysis in various light imaging equipment with presenting linear response behavior of constant light emitting sources to measurement time

Kim, Hyeon Sik; Min, Jung Joon; Lee, Byeong Il [Chonnam National University Hospital, Hwasun (Korea, Republic of); Choi, Eun Seo [Chosun University, Gwangju (Korea, Republic of); Tak, Yoon O; Choi, Heung Kook; Lee, Ju Young [Inje University, Kimhae (Korea, Republic of)

2009-10-15

28

Development of Quantification Method for Bioluminescence Imaging  

International Nuclear Information System (INIS)

Optical molecular luminescence imaging is widely used for detection and imaging of bio-photons emitted by luminescent luciferase activation. The measured photons in this method provide the degree of molecular alteration or cell numbers with the advantage of high signal-to-noise ratio. To extract useful information from the measured results, the analysis based on a proper quantification method is necessary. In this research, we propose a quantification method presenting linear response of measured light signal to measurement time. We detected the luminescence signal by using lab-made optical imaging equipment of animal light imaging system (ALIS) and different two kinds of light sources. One is three bacterial light-emitting sources containing different number of bacteria. The other is three different non-bacterial light sources emitting very weak light. By using the concept of the candela and the flux, we could derive simplified linear quantification formula. After experimentally measuring light intensity, the data was processed with the proposed quantification function. We could obtain linear response of photon counts to measurement time by applying the pre-determined quantification function. The ratio of the re-calculated photon counts and measurement time present a constant value although different light source was applied. The quantification function for linear response could be applicable to the standard quantification process. The proposed method could be used focess. The proposed method could be used for the exact quantitative analysis in various light imaging equipment with presenting linear response behavior of constant light emitting sources to measurement time

29

Hyperspectral and multispectral bioluminescence optical tomography for small animal imaging  

International Nuclear Information System (INIS)

For bioluminescence imaging studies in small animals, it is important to be able to accurately localize the three-dimensional (3D) distribution of the underlying bioluminescent source. The spectrum of light produced by the source that escapes the subject varies with the depth of the emission source because of the wavelength-dependence of the optical properties of tissue. Consequently, multispectral or hyperspectral data acquisition should help in the 3D localization of deep sources. In this paper, we describe a framework for fully 3D bioluminescence tomographic image acquisition and reconstruction that exploits spectral information. We describe regularized tomographic reconstruction techniques that use semi-infinite slab or FEM-based diffusion approximations of photon transport through turbid media. Singular value decomposition analysis was used for data dimensionality reduction and to illustrate the advantage of using hyperspectral rather than achromatic data. Simulation studies in an atlas-mouse geometry indicated that sub-millimeter resolution may be attainable given accurate knowledge of the optical properties of the animal. A fixed arrangement of mirrors and a single CCD camera were used for simultaneous acquisition of multispectral imaging data over most of the surface of the animal. Phantom studies conducted using this system demonstrated our ability to accurately localize deep point-like sources and show that a resolution of 1.5 to 2.2 mm for depths up to 6 mmion of 1.5 to 2.2 mm for depths up to 6 mm can be achieved. We also include an in vivo study of a mouse with a brain tumour expressing firefly luciferase. Co-registration of the reconstructed 3D bioluminescent image with magnetic resonance images indicated good anatomical localization of the tumour

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Bioluminescence Imaging of Stem Cell-Based Therapeutics for Vascular Regeneration  

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Stem cell-based therapeutics show promise for treatment of vascular diseases. However, the survival of the cells after in vivo injection into diseased tissues remains a concern. In the advent of non-invasive optical imaging techniques such as bioluminescence imaging (BLI), cell localization and survival can be easily monitored over time. This approach has recently been applied towards monitoring stem cell treatments for vascular regeneration of the coronary or peripheral arteries. I...

Ngan F Huang, Janet Okogbaa

2012-01-01

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Engineering Bioluminescent Proteins: Expanding their Analytical Potential  

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Bioluminescence has been observed in nature since the dawn of time, but now, scientists are harnessing it for analytical applications. Laura Rowe, Emre Dikici, and Sylvia Daunert of the University of Kentucky describe the origins of bioluminescent proteins and explore their uses in the modern chemistry laboratory. The cover features spectra of bioluminescent light superimposed on an image of jellyfish, which are a common source of bioluminescent proteins. Images courtesy of Emre Dikici and Sh...

Rowe, Laura; Dikici, Emre; Daunert, Sylvia

2009-01-01

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Bioluminescence imaging: a shining future for cardiac regeneration  

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Advances in bioanalytical techniques have become crucial for both basic research and medical practice. One example, bioluminescence imaging (BLI), is based on the application of natural reactants with light-emitting capabilities (photoproteins and luciferases) isolated from a widespread group of organisms. The main challenges in cardiac regeneration remain unresolved, but a vast number of studies have harnessed BLI with the discovery of aequorin and green fluorescent proteins. First described...

Roura, Santiago; Ga?lvez-monto?n, Carolina; Bayes-genis, Antoni

2013-01-01

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Filtering and deconvolution for bioluminescence imaging of small animals; Filtrage et deconvolution en imagerie de bioluminescence chez le petit animal  

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This thesis is devoted to analysis of bioluminescence images applied to the small animal. This kind of imaging modality is used in cancerology studies. Nevertheless, some problems are related to the diffusion and the absorption of the tissues of the light of internal bioluminescent sources. In addition, system noise and the cosmic rays noise are present. This influences the quality of the images and makes it difficult to analyze. The purpose of this thesis is to overcome these disturbing effects. We first have proposed an image formation model for the bioluminescence images. The processing chain is constituted by a filtering stage followed by a deconvolution stage. We have proposed a new median filter to suppress the random value impulsive noise which corrupts the acquired images; this filter represents the first block of the proposed chain. For the deconvolution stage, we have performed a comparative study of various deconvolution algorithms. It allowed us to choose a blind deconvolution algorithm initialized with the estimated point spread function of the acquisition system. At first, we have validated our global approach by comparing our obtained results with the ground truth. Through various clinical tests, we have shown that the processing chain allows a significant improvement of the spatial resolution and a better distinction of very close tumor sources, what represents considerable contribution for the users of bioluminescence images. (author)

Akkoul, S.

2010-06-22

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SUBCELLULAR IMAGING OF DYNAMIC PROTEIN INTERACTIONS BY BIOLUMINESCENCE RESONANCE ENERGY TRANSFER.  

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Despite the fact that numerous studies suggest the existence of receptor multiprotein complexes, visualization and monitoring of the dynamics of such protein assemblies remains a challenge. In the present study we established appropriate conditions to study spatio-temporally-resolved images of such protein assemblies using bioluminescence resonance energy transfer (BRET) in mammalian living cells. Using covalently linked renilla-luciferase and yellow fluorescent proteins, we depicted the time...

Coulon, Vincent; Audet, Martin; Homburger, Vincent; Bockaert, Joel; Fagni, Laurent; Bouvier, Michel; Perroy, Julie

2007-01-01

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A novel luciferase fusion protein for highly sensitive optical imaging: from single-cell analysis to in vivo whole-body bioluminescence imaging.  

Science.gov (United States)

Fluorescence and bioluminescence imaging have different advantages and disadvantages depending on the application. Bioluminescence imaging is now the most sensitive optical technique for tracking cells, promoter activity studies, or for longitudinal in vivo preclinical studies. Far-red and near-infrared fluorescence imaging have the advantage of being suitable for both ex vivo and in vivo analysis and have translational potential, thanks to the availability of very sensitive imaging instrumentation. Here, we report the development and validation of a new luciferase fusion reporter generated by the fusion of the firefly luciferase Luc2 to the far-red fluorescent protein TurboFP635 by a 14-amino acid linker peptide. Expression of the fusion protein, named TurboLuc, was analyzed in human embryonic kidney cells, (HEK)-293 cells, via Western blot analysis, fluorescence microscopy, and in vivo optical imaging. The created fusion protein maintained the characteristics of the original bioluminescent and fluorescent protein and showed no toxicity when expressed in living cells. To assess the sensitivity of the reporter for in vivo imaging, transfected cells were subcutaneously injected in animals. Detection limits of cells were 5?×?10(3) and 5?×?10(4) cells for bioluminescent and fluorescent imaging, respectively. In addition, hydrodynamics-based in vivo gene delivery using a minicircle vector expressing TurboLuc allowed for the analysis of luminescent signals over time in deep tissue. Bioluminescence could be monitored for over 30 days in the liver of animals. In conclusion, TurboLuc combines the advantages of both bioluminescence and fluorescence and allows for highly sensitive optical imaging ranging from single-cell analysis to in vivo whole-body bioluminescence imaging. PMID:24958343

Mezzanotte, Laura; Blankevoort, Vicky; Löwik, Clemens W G M; Kaijzel, Eric L

2014-09-01

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DEVELOPMENT OF A DUAL MODALITY TOMOGRAPHIC IMAGING SYSTEM FOR BIOLUMINESCENCE AND PET  

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The goal of this proposal was to develop a new hybrid imaging modality capable to simultaneously image optical bioluminescence signals, as well as radionuclide emissions from the annihilation of positrons originating from molecular imaging probes in preclinical mouse models. This new technology enables the simultaneous in-vivo measurements of both emissions that could be produced from a single or a combination of two different biomarkers. It also facilitates establishing the physical limitations of bioluminescence imaging, its tomographic and spectral image reconstruction potential and the quantification of bioluminescence signals.

CHATZIIOANNOU, ARION

2011-12-21

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Assessing laser-tissue damage with bioluminescent imaging.  

Science.gov (United States)

Effective medical laser procedures are achieved by selecting laser parameters that minimize undesirable tissue damage. Traditionally, human subjects, animal models, and monolayer cell cultures have been used to study wound healing, tissue damage, and cellular effects of laser radiation. Each of these models has significant limitations, and consequently, a novel skin model is needed. To this end, a highly reproducible human skin model that enables noninvasive and longitudinal studies of gene expression was sought. In this study, we present an organotypic raft model (engineered skin) used in combination with bioluminescent imaging (BLI) techniques. The efficacy of the raft model was validated and characterized by investigating the role of heat shock protein 70 (hsp70) as a sensitive marker of thermal damage. The raft model consists of human cells incorporated into an extracellular matrix. The raft cultures were transfected with an adenovirus containing a murine hsp70 promoter driving transcription of luciferase. The model enables quantitative analysis of spatiotemporal expression of proteins using BLI. Thermal stress was induced on the raft cultures by means of a constant temperature water bath or with a carbon dioxide (CO2) laser (lambda=10.6 microm, 0.679 to 2.262 Wcm2, cw, unfocused Gaussian beam, omegaL=4.5 mm, 1 min exposure). The bioluminescence was monitored noninvasively with an IVIS 100 Bioluminescent Imaging System. BLI indicated that peak hsp70 expression occurs 4 to 12 h after exposure to thermal stress. A minimum irradiance of 0.679 Wcm2 activated the hsp70 response, and a higher irradiance of 2.262 Wcm2 was associated with a severe reduction in hsp70 response due to tissue ablation. Reverse transcription polymerase chain reaction demonstrated that hsp70 mRNA levels increased with prolonged heating exposures. Enzyme-linked immunosorbent protein assays confirmed that luciferase was an accurate surrogate for hsp70 intracellular protein levels. Hematoxylin and eosin stains verified the presence of the thermally denatured tissue regions. Immunohistochemical analyses confirmed that maximal hsp70 expression occurred at a depth of 150 microm. Bioluminescent microscopy was employed to corroborate these findings. These results indicate that quantitative BLI in engineered tissue equivalents provides a powerful model that enables sequential gene expression studies. Such a model can be used as a high throughput screening platform for laser-tissue interaction studies. PMID:16965142

Wilmink, Gerald J; Opalenik, Susan R; Beckham, Joshua T; Davidson, Jeffrey M; Jansen, E Duco

2006-01-01

38

Assessing laser-tissue damage with bioluminescent imaging  

Science.gov (United States)

Effective medical laser procedures are achieved by selecting laser parameters that minimize undesirable tissue damage. Traditionally, human subjects, animal models, and monolayer cell cultures have been used to study wound healing, tissue damage, and cellular effects of laser radiation. Each of these models has significant limitations, and consequently, a novel skin model is needed. To this end, a highly reproducible human skin model that enables noninvasive and longitudinal studies of gene expression was sought. In this study, we present an organotypic raft model (engineered skin) used in combination with bioluminescent imaging (BLI) techniques. The efficacy of the raft model was validated and characterized by investigating the role of heat shock protein 70 (hsp70) as a sensitive marker of thermal damage. The raft model consists of human cells incorporated into an extracellular matrix. The raft cultures were transfected with an adenovirus containing a murine hsp70 promoter driving transcription of luciferase. The model enables quantitative analysis of spatiotemporal expression of proteins using BLI. Thermal stress was induced on the raft cultures by means of a constant temperature water bath or with a carbon dioxide (CO2) laser (?=10.6 µm, 0.679 to 2.262 W/cm2, cw, unfocused Gaussian beam, ?L=4.5 mm, 1 min exposure). The bioluminescence was monitored noninvasively with an IVIS 100 Bioluminescent Imaging System. BLI indicated that peak hsp70 expression occurs 4 to 12 h after exposure to thermal stress. A minimum irradiance of 0.679 W/cm2 activated the hsp70 response, and a higher irradiance of 2.262 W/cm2 was associated with a severe reduction in hsp70 response due to tissue ablation. Reverse transcription polymerase chain reaction demonstrated that hsp70 mRNA levels increased with prolonged heating exposures. Enzyme-linked immunosorbent protein assays confirmed that luciferase was an accurate surrogate for hsp70 intracellular protein levels. Hematoxylin and eosin stains verified the presence of the thermally denatured tissue regions. Immunohistochemical analyses confirmed that maximal hsp70 expression occurred at a depth of 150 µm. Bioluminescent microscopy was employed to corroborate these findings. These results indicate that quantitative BLI in engineered tissue equivalents provides a powerful model that enables sequential gene expression studies. Such a model can be used as a high throughput screening platform for laser-tissue interaction studies.

Wilmink, Gerald J.; Opalenik, Susan R.; Beckham, Josh T.; Davidson, Jeffrey M.; Jansen, Eric D.

2006-07-01

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In vivo fluorescence imaging of the reticuloendothelial system using quantum dots in combination with bioluminescent tumour monitoring  

International Nuclear Information System (INIS)

We characterised in vivo fluorescence imaging (FLI) of the reticuloendothelial system using quantum dots (QD) and investigated its use in combination with in vivo bioluminescence imaging (BLI). In vivo FLI was performed in five mice repeatedly after the intravenous administration of QD without conjugation to targeting ligands. Ex vivo FLI of the excised organs was performed 24 h after QD injection in three mice. Seven days after intravenous inoculation of luciferase-expressing model cells of a haematological malignancy, mice were injected with the QD or saline (n = 5 each), and combined BLI/FLI was performed repeatedly. Additional five mice inoculated with the tumour cells were examined by in vivo BLI/FLI, and the structures harbouring bioluminescent foci were determined by ex vivo BLI. The utility of combining FLI with bioluminescent tumour monitoring was evaluated. In vivo FLI after QD injection allowed long-term, repeated observation of the reticuloendothelial system in individual mice, although fluorescence intensity and image contrast gradually decreased over time. Ex vivo FLI verified selective accumulation in reticuloendothelial structures. The administration of QD did not affect whole-body bioluminescent signal intensities during longitudinal tumour monitoring. In vivo BLI/FLI, accompanied by fusion of both images, improved the accuracy and confidence level of the localisation of the bioluminescent foci. In vivo FLI using QD provides an overview of the reticuling QD provides an overview of the reticuloendothelial system in living mice. In combination with bioluminescent tumour monitoring, fluorescent reticuloendothelial imaging is expected to provide valuable information for lesion localisation. (orig.)

40

In Vivo Bioluminescence Imaging of Tumor Cells Using Optimized Firefly Luciferase luc2  

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Full Text Available The present study was aimed to establish a tumor cell line stably expressing luciferase luc2, and to develop the technique to observe primary tumor nodes and metastases using in vivo bioluminescence imaging. Materials and Methods. In this research we used pLuc2-N plasmid, lentiviral vector pLVT-1, Colo 26 cell line and BALB/c mice to generate new bioluminescent tumor model. Bioluminescence imaging in vitro ? in vivo was carried out on IVIS-Spectrum system (Caliper Life Sciences, USA. Primary tumor model was created by subcutaneous injection of 500 000 Colo 26-luc2 cells. Model of metastases was generated by i.v. injection of 75 000 Colo 26-luc2 cells. Histological analysis was performed to verify the results of the imaging. Results. We created the lentiviral vector containing luc2 gene using molecular cloning. Then Colo 26-luc2 tumor cell line was generated. We assessed the sensitivity of luc2-based bioluminescence imaging. The intensity of bioluminescent signal in vitro averaged about 5000 photon/s per cell, in vivo — 250 photon/sec per cell. In vivo monitoring of Colo 26-luc2 primary tumor and metastases was demonstrated. The results of bioluminescence imaging correlated with histological analysis data. Conclusion. The present work shows the possibility of bioluminescent system based on optimized luciferase luc2 for in vivo noninvasive high-sensitive whole-body imaging of tumors.

N.V. Klementyeva

2013-08-01

 
 
 
 
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In vivo heterogeneous tomographic bioluminescence imaging via a higher-order approximation forward model  

Science.gov (United States)

In vivo bioluminescence imaging (BLI) has played a more and more important role in biomedical research of small animals. Tomographic bioluminescence imaging (TBI) further translates the BLI optical information into three-dimensional bioluminescent source distribution, which could greatly facilitate applications in related studies. Although the diffusion approximation (DA) is one of the most widely-used forward models, higher-order approximations are still needed for in vivo small animal imaging. In this work, as a relatively accurate and higher-order approximation theory, a simplified spherical harmonics approximation (SPN) is applied for heterogeneous tomographic bioluminescence imaging in vivo. Furthermore, coupled with the SPN, a generalized graph cuts optimization approach is utilized, making BLT reconstructions fast and suit for the whole body of small animals. Heterogeneous in vivo experimental reconstructions via the higher-order approximation model demonstrate higher tomographic imaging quality, which is shown the capability for practical biomedical tomographic imaging applications.

Liu, Kai; Tian, Jie, Sr.; Qin, Chenghu; Yang, Xin; Zhu, Shouping; Han, Dong; Wu, Ping; Dai, Xiaoqian

2011-03-01

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In vivo bioluminescence imaging and histopathopathologic analysis reveal distinct roles for resident and recruited immune effector cells in defense against invasive aspergillosis  

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Abstract Background Invasive aspergillosis (IA) is a major cause of infectious morbidity and mortality in immune compromised patients. Studies on the pathogenesis of IA have been limited by the difficulty to monitor disease progression in real-time. For real-time monitoring of the infection, we recently engineered a bioluminescent A. fumigatus strain. Results In this study, we demonstrate that bioluminescence imaging can track the progression of IA at d...

Schwendener Reto; Adib-Conquy Minou; Kim Oh; Philippart François; Droin-Bergère Sabrina; Hohl Tobias M; Jouvion Grégory; Ibrahim-Granet Oumaïma; Cavaillon Jean-Marc; Brock Matthias

2010-01-01

43

Monitoring and quantitative assessment of tumor burden using in vivo bioluminescence imaging  

Science.gov (United States)

In vivo bioluminescence imaging (BLI) is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating tumor growth. In this study, the kinetic of tumor growth has been assessed in C26 colon carcinoma bearing BALB/c mouse model. The ability of BLI to noninvasively quantitate the growth of subcutaneous tumors transplanted with C26 cells genetically engineered to stably express firefly luciferase and herpes simplex virus type-1 thymidine kinase (C26/ tk-luc). A good correlation ( R2=0.998) of photon emission to the cell number was found in vitro. Tumor burden and tumor volume were monitored in vivo over time by quantitation of photon emission using Xenogen IVIS 50 and standard external caliper measurement, respectively. At various time intervals, tumor-bearing mice were imaged to determine the correlation of in vivo BLI to tumor volume. However, a correlation of BLI to tumor volume was observed when tumor volume was smaller than 1000 mm 3 ( R2=0.907). ? Scintigraphy combined with [ 131I]FIAU was another imaging modality used for verifying the previous results. In conclusion, this study showed that bioluminescence imaging is a powerful and quantitative tool for the direct assay to monitor tumor growth in vivo. The dual reporter genes transfected tumor-bearing animal model can be applied in the evaluation of the efficacy of new developed anti-cancer drugs.

Chen, Chia-Chi; Hwang, Jeng-Jong; Ting, Gann; Tseng, Yun-Long; Wang, Shyh-Jen; Whang-Peng, Jaqueline

2007-02-01

44

Monitoring and quantitative assessment of tumor burden using in vivo bioluminescence imaging  

International Nuclear Information System (INIS)

In vivo bioluminescence imaging (BLI) is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating tumor growth. In this study, the kinetic of tumor growth has been assessed in C26 colon carcinoma bearing BALB/c mouse model. The ability of BLI to noninvasively quantitate the growth of subcutaneous tumors transplanted with C26 cells genetically engineered to stably express firefly luciferase and herpes simplex virus type-1 thymidine kinase (C26/tk-luc). A good correlation (R 2=0.998) of photon emission to the cell number was found in vitro. Tumor burden and tumor volume were monitored in vivo over time by quantitation of photon emission using Xenogen IVIS 50 and standard external caliper measurement, respectively. At various time intervals, tumor-bearing mice were imaged to determine the correlation of in vivo BLI to tumor volume. However, a correlation of BLI to tumor volume was observed when tumor volume was smaller than 1000 mm3 (R 2=0.907). ? Scintigraphy combined with [131I]FIAU was another imaging modality used for verifying the previous results. In conclusion, this study showed that bioluminescence imaging is a powerful and quantitative tool for the direct assay to monitor tumor growth in vivo. The dual reporter genes transfected tumor-bearing animal model can be applied in the evaluation of the efficacy of new developed anti-cancer drugsr drugs

45

Monitoring and quantitative assessment of tumor burden using in vivo bioluminescence imaging  

Energy Technology Data Exchange (ETDEWEB)

In vivo bioluminescence imaging (BLI) is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating tumor growth. In this study, the kinetic of tumor growth has been assessed in C26 colon carcinoma bearing BALB/c mouse model. The ability of BLI to noninvasively quantitate the growth of subcutaneous tumors transplanted with C26 cells genetically engineered to stably express firefly luciferase and herpes simplex virus type-1 thymidine kinase (C26/tk-luc). A good correlation (R {sup 2}=0.998) of photon emission to the cell number was found in vitro. Tumor burden and tumor volume were monitored in vivo over time by quantitation of photon emission using Xenogen IVIS 50 and standard external caliper measurement, respectively. At various time intervals, tumor-bearing mice were imaged to determine the correlation of in vivo BLI to tumor volume. However, a correlation of BLI to tumor volume was observed when tumor volume was smaller than 1000 mm{sup 3} (R {sup 2}=0.907). {gamma} Scintigraphy combined with [{sup 131}I]FIAU was another imaging modality used for verifying the previous results. In conclusion, this study showed that bioluminescence imaging is a powerful and quantitative tool for the direct assay to monitor tumor growth in vivo. The dual reporter genes transfected tumor-bearing animal model can be applied in the evaluation of the efficacy of new developed anti-cancer drugs.

Chen, C.-C. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China); Hwang, Jeng-Jong [Institute of Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China)]. E-mail: jjhwang@ym.edu.tw; Ting, G. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China); Tseng, Y.-L. [Taiwan Liposome Company, Taipei 115, Taiwan (China); Wang, S.-J. [Department of Nuclear Medicine, Veterans General Hospital, Taipei 112, Taiwan (China); Whang-Peng, J. [Cancer Research Division, National Health Research Institute, Miaoli 350, Taiwan (China)

2007-02-01

46

Multimodal imaging of orthotopic hepatocellular carcinoma using small animal PET, bioluminescence and contrast enhanced CT imaging  

International Nuclear Information System (INIS)

Molecular imaging with small-animal PET and bioluminescence imaging has been used as an important tool in cancer research. One of the disadvantages of these imaging modalities is the lack of anatomic information. To obtain fusion images with both molecular and anatomical information, small-animal PET and bioluminescence images fused with contrast enhance CT image in orthotopic hepatocellular carcinoma (HCC) model. We retrovially transfected dual gene (HSV1-tk and firefly luciferase) to morris hepatoma cells. The expression of HSV1-tk and luciferase was checked by optical imager and in vitro radiolabeled FIAU uptake, respectively and also checked by RT-PCR analysis. MCA-TL cells (5X105/ 0.05 ml) mixed with matrigel (1: 10) injected into left lobe of liver in nude mice. 124I-FIAU-PET, bioluminescence and contrast enhanced CT images were obtained in the orthotopic HCC model and digital whole body autoradiography (DWBA) was performed. Small animal PET image was obtained at 2 h post injection of 124I-FIAU and contrast enhanced CT image was obtained at 3 h post injection of Fenestra LC (0.3 ml). MCA-TL cells showed more specific 124I-FIAU uptake and higher luminescent activity than parental cells. The orthotopic HCC was detected by 124I-FIAU PET, contrast enhanced CT, and BLI and confirmed by DWBA. Registered image in orthotopic HCC t models showed a good correlation of images from both PET and CT. Contrast enhanced CT rom both PET and CT. Contrast enhanced CT image delineated margin of HCC. Multimodal imaging with 124I-FIAU PET, bioluminescence and contrast enhanced CT allows a precise and improved detection of tumor in orthotopic hepatocellular carcinoma model. Multimodal imaging is potentially useful for monitoring progression of hepatic metastasis and for the evaluation of cancer treatments

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Let There Be Light! Bioluminescent Imaging to Study Bacterial Pathogenesis in Live Animals and Plants.  

Science.gov (United States)

: Bioluminescence imaging (BLI) of bacteria was primarily designed to permit real-time, sensitive, and noninvasive monitoring of the progression of infection in live animals. Generally, BLI relies on the construction of bacterial strains that possess the lux operon. The lux operon is composed of a set of genes that encode the luciferase enzyme and its cognate substrate, which interact to produce light-a phenomenon that is referred to as bioluminescence. Bioluminescence emitted by the bacteria can then be detected and imaged within a living host using sensitive charge-coupled device (CCD) cameras. In comparison to traditional host-pathogen studies, BLI offers the opportunity for extended monitoring of infected animals without resorting to euthanasia and extensive tissue processing at each time point. Therefore, BLI can reduce the number of animals required to generate meaningful data, while significantly contributing to the understanding of pathogenesis in the host and, subsequently, the development and evaluation of adequate vaccines and therapeutics. BLI is also useful in characterizing the interactions of pathogens with plants and the para-host environment. In this chapter, we demonstrate the broad application of BLI for studying bacterial pathogens in different niches. Furthermore, we will specifically focus on the use of BLI to characterize the following: (1) the pathogenesis of Brucella melitensis in mice (animal host), and (2) the progression of infection of Clavibacter michiganensis subsp. michiganensis in tomatoes (plant host). These studies will provide an overview of the wide potential of BLI and its role in enhancing the study of unique-and sometimes difficult-to-characterize-bacterial pathogens. PMID:25395174

Kassem, Issmat I; Splitter, Gary A; Miller, Sally; Rajashekara, Gireesh

2014-11-14

48

Use of a highly sensitive two-dimensional luminescence imaging system to monitor endogenous bioluminescence in plant leaves  

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Full Text Available Abstract Background All living organisms emit spontaneous low-level bioluminescence, which can be increased in response to stress. Methods for imaging this ultra-weak luminescence have previously been limited by the sensitivity of the detection systems used. Results We developed a novel configuration of a cooled charge-coupled device (CCD for 2-dimensional imaging of light emission from biological material. In this study, we imaged photon emission from plant leaves. The equipment allowed short integration times for image acquisition, providing high resolution spatial and temporal information on bioluminescence. We were able to carry out time course imaging of both delayed chlorophyll fluorescence from whole leaves, and of low level wound-induced luminescence that we showed to be localised to sites of tissue damage. We found that wound-induced luminescence was chlorophyll-dependent and was enhanced at higher temperatures. Conclusions The data gathered on plant bioluminescence illustrate that the equipment described here represents an improvement in 2-dimensional luminescence imaging technology. Using this system, we identify chlorophyll as the origin of wound-induced luminescence from leaves.

Flor-Henry Michel

2004-11-01

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Compartmentalization of algal bioluminescence: autofluorescence of bioluminescent particles in the dinoflagellate Gonyaulax as studied with image-intensified video microscopy and flow cytometry  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Compartmentalization of specialized functions to discrete locales is a fundamental theme of eucaryotic organization in cells. We report here that bioluminescence of the dinoflagellate alga Gonyaulax originates in vivo from discrete subcellular loci that are intrinsically fluorescent. We demonstrate this localization by comparing the loci of fluorescence and bioluminescence as visualized by image-intensified video microscopy. These fluorescent particles appeared to be the same as the previousl...

1985-01-01

50

Bioluminescence imaging of human embryonic stem cells transplanted in vivo in murine and chick models.  

Science.gov (United States)

Research into the behavior, efficacy, and biosafety of stem cells with a view to clinical transplantation requires the development of noninvasive methods for in vivo imaging of cells transplanted into animal models. This is particularly relevant for human embryonic stem cells (hESCs), because transplantation of undifferentiated hESCs leads to tumor formation. The present study aimed to monitor hESCs in real time when injected in vivo. hESCs were stably transfected to express luciferase, and luciferase expression was clearly detected in the undifferentiated and differentiated state. When transfected hESCs were injected into chick embryos, bioluminescence could be detected both ex and in ovo. In the SCID mouse model, undifferentiated hESCs were detectable after injection either into the muscle layer of the peritoneum or the kidney capsule. Tumors became detectable between days 10-30, with approximately a 3 log increase in the luminescence signal by day 75. The growth phase occurred earlier in the kidney capsule and then reached a plateau, whilst tumors in the peritoneal wall grew steadily throughout the period analysed. These results show the widespread utility of bioluminescent for in vivo imaging of hESCs in a variety of model systems for preclinical research into regenerative medicine and cancer biology. PMID:19522673

Priddle, Helen; Grabowska, Anna; Morris, Teresa; Clarke, Philip A; McKenzie, Andrew J; Sottile, Virginie; Denning, Chris; Young, Lorraine; Watson, Sue

2009-06-01

51

In vivo bioluminescence imaging and histopathopathologic analysis reveal distinct roles for resident and recruited immune effector cells in defense against invasive aspergillosis  

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Full Text Available Abstract Background Invasive aspergillosis (IA is a major cause of infectious morbidity and mortality in immune compromised patients. Studies on the pathogenesis of IA have been limited by the difficulty to monitor disease progression in real-time. For real-time monitoring of the infection, we recently engineered a bioluminescent A. fumigatus strain. Results In this study, we demonstrate that bioluminescence imaging can track the progression of IA at different anatomic locations in a murine model of disease that recapitulates the natural route of infection. To define the temporal and functional requirements of distinct innate immune cellular subsets in host defense against respiratory A. fumigatus infection, we examined the development and progression of IA using bioluminescence imaging and histopathologic analysis in mice with four different types of pharmacologic or numeric defects in innate immune function that target resident and recruited phagocyte subsets. While bioluminescence imaging can track the progression and location of invasive disease in vivo, signals can be attenuated by severe inflammation and associated tissue hypoxia. However, especially under non-inflammatory conditions, such as cyclophosphamide treatment, an increasing bioluminescence signal reflects the increasing biomass of alive fungal cells. Conclusions Imaging studies allowed an in vivo correlation between the onset, peak, and kinetics of hyphal tissue invasion from the lung under conditions of functional or numeric inactivation of phagocytes and sheds light on the germination speed of conidia under the different immunosuppression regimens. Conditions of high inflammation -either mediated by neutrophil influx under corticosteroid treatment or by monocytes recruited during antibody-mediated depletion of neutrophils- were associated with rapid conidial germination and caused an early rise in bioluminescence post-infection. In contrast, 80% alveolar macrophage depletion failed to trigger a bioluminescent signal, consistent with the notion that neutrophil recruitment is essential for early host defense, while alveolar macrophage depletion can be functionally compensated.

Schwendener Reto

2010-04-01

52

Functional imaging of interleukin 1 beta expression in inflammatory process using bioluminescence imaging in transgenic mice  

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Full Text Available Abstract Background Interleukin 1 beta (IL-1? plays an important role in a number of chronic and acute inflammatory diseases. To understand the role of IL-1? in disease processes and develop an in vivo screening system for anti-inflammatory drugs, a transgenic mouse line was generated which incorporated the transgene firefly luciferase gene driven by a 4.5-kb fragment of the human IL-1? gene promoter. Luciferase gene expression was monitored in live mice under anesthesia using bioluminescence imaging in a number of inflammatory disease models. Results In a LPS-induced sepsis model, dramatic increase in luciferase activity was observed in the mice. This transgene induction was time dependent and correlated with an increase of endogenous IL-1? mRNA and pro-IL-1? protein levels in the mice. In a zymosan-induced arthritis model and an oxazolone-induced skin hypersensitivity reaction model, luciferase expression was locally induced in the zymosan injected knee joint and in the ear with oxazolone application, respectively. Dexamethasone suppressed the expression of luciferase gene both in the acute sepsis model and in the acute arthritis model. Conclusion Our data suggest that the transgenic mice model could be used to study transcriptional regulation of the IL-1? gene expression in the inflammatory process and evaluation the effect of anti-inflammatory drug in vivo.

Liu Zhihui

2008-08-01

53

Bioluminescence in vivo imaging of autoimmune encephalomyelitis predicts disease  

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Abstract Background Experimental autoimmune encephalomyelitis is a widely used animal model to understand not only multiple sclerosis but also basic principles of immunity. The disease is scored typically by observing signs of paralysis, which do not always correspond with pathological changes. Methods Experimental autoimmune encephalomyelitis was induced in transgenic mice expressing an injury responsive luciferase reporter in astrocytes (GFAP-luc). Bioluminesc...

Steinman Lawrence; Ho Peggy; Luo Jian; Wyss-Coray Tony

2008-01-01

54

Evaluation of biolistic gene transfer methods in vivo using non-invasive bioluminescent imaging techniques  

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Full Text Available Abstract Background Gene therapy continues to hold great potential for treating many different types of disease and dysfunction. Safe and efficient techniques for gene transfer and expression in vivo are needed to enable gene therapeutic strategies to be effective in patients. Currently, the most commonly used methods employ replication-defective viral vectors for gene transfer, while physical gene transfer methods such as biolistic-mediated ("gene-gun" delivery to target tissues have not been as extensively explored. In the present study, we evaluated the efficacy of biolistic gene transfer techniques in vivo using non-invasive bioluminescent imaging (BLI methods. Results Plasmid DNA carrying the firefly luciferase (LUC reporter gene under the control of the human Cytomegalovirus (CMV promoter/enhancer was transfected into mouse skin and liver using biolistic methods. The plasmids were coupled to gold microspheres (1 ?m diameter using different DNA Loading Ratios (DLRs, and "shot" into target tissues using a helium-driven gene gun. The optimal DLR was found to be in the range of 4-10. Bioluminescence was measured using an In Vivo Imaging System (IVIS-50 at various time-points following transfer. Biolistic gene transfer to mouse skin produced peak reporter gene expression one day after transfer. Expression remained detectable through four days, but declined to undetectable levels by six days following gene transfer. Maximum depth of tissue penetration following biolistic transfer to abdominal skin was 200-300 ?m. Similarly, biolistic gene transfer to mouse liver in vivo also produced peak early expression followed by a decline over time. In contrast to skin, however, liver expression of the reporter gene was relatively stable 4-8 days post-biolistic gene transfer, and remained detectable for nearly two weeks. Conclusions The use of bioluminescence imaging techniques enabled efficient evaluation of reporter gene expression in vivo. Our results demonstrate that different tissues show different expression kinetics following gene transfer of the same reporter plasmid to different mouse tissues in vivo. We evaluated superficial (skin and abdominal organ (liver targets, and found that reporter gene expression peaked within the first two days post-transfer in each case, but declined most rapidly in the skin (3-4 days compared to liver (10-14 days. This information is essential for designing effective gene therapy strategies in different target tissues.

Daniell Henry

2011-06-01

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Bioluminescence imaging to monitor the prolongation of stem cell survival by pharmaceutical intervention  

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The rapid donor cell death and rejection owing to humoral and cellular immune reactions are a basic limitation encountered in stem cell therapy for treatment of cardiovascular disease. We investigated the potential for longitudinal bioluminescence imaging to monitor the survival of transplanted stem cells prolonged by immunosuppressive agents. Embryonic rat H9c2 cardio myoblasts were transfected with adenovirus containing luciferase reporter gene (Ad-CMV-Fluc) in different MOI (1,10,100) and various cell doses (1x10{sup 5} - 5x10{sup 6})followed by injection in the thigh muscle of nude mice (n=6 per group), Other mice (n = 18) were undergone transient immunosuppression provided by either Cyclosporine (5mg/kg) or Tacrolimus (1mg/kg) or Dexamethasone (4mg/kg) beginning 3 days prior to and continuing to 2 weeks after transplantation. Optical bioluminescent imaging was then daily carried out using cooled CCD camera (Xenogen) Viral transfection at MOI 100 and the 5x10{sup 6} cell dose implantation resulted in optimal transgene efficiency. Mice received immunosuppressive agents displayed long-term in vivo reporter gene expression for a time course of 14 days. Tacrolimus (Prograf) and Cyclosporine successfully suppressed the transplanted cell loss in animals, that obviously observed until day 8 as compared to Dexamethasone-treated and non-treated mice (day 1: 1.00E+08 (Prograf), 9.47E+07 (Cys), 5.25E+07 (Dex), and 1.25E+07 p/s/cm{sup 2}/sr (control); day 8: 3.27E+05 (Prograf), 1.02E+05 (Cys), 6.17E+04 (Dex) and 2.73E+04 p/s/cm{sup 2}/sr (control)) and continued expressing bioluminescence until day 13 ( 6.42E+05 (Prograf), 4.99E+05 (Cys), and 4.10E+04 p/s/cm{sup 2}/sr. Induction of immune tolerance using pharmaceutical agents during cardio myoblast transplantation improved long-term donor cell survival in murine muscles. Optical imaging technique is capable of being used for tracking implanted stem cells in myocardium of living subjects over time.

Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Ahn, Young Keun; Kim, Yong Sook; Joo, Soo Yeon; Hong, Moon Hwa; Jeong, Myung Ho; Song, Ho Cheon; Bom, Hee Seung [Chonnam National University Medical School, Gwangju (Korea, Republic of)

2005-07-01

56

Bioluminescence imaging to monitor the prolongation of stem cell survival by pharmaceutical intervention  

International Nuclear Information System (INIS)

The rapid donor cell death and rejection owing to humoral and cellular immune reactions are a basic limitation encountered in stem cell therapy for treatment of cardiovascular disease. We investigated the potential for longitudinal bioluminescence imaging to monitor the survival of transplanted stem cells prolonged by immunosuppressive agents. Embryonic rat H9c2 cardio myoblasts were transfected with adenovirus containing luciferase reporter gene (Ad-CMV-Fluc) in different MOI (1,10,100) and various cell doses (1x105 - 5x106)followed by injection in the thigh muscle of nude mice (n=6 per group), Other mice (n = 18) were undergone transient immunosuppression provided by either Cyclosporine (5mg/kg) or Tacrolimus (1mg/kg) or Dexamethasone (4mg/kg) beginning 3 days prior to and continuing to 2 weeks after transplantation. Optical bioluminescent imaging was then daily carried out using cooled CCD camera (Xenogen) Viral transfection at MOI 100 and the 5x106 cell dose implantation resulted in optimal transgene efficiency. Mice received immunosuppressive agents displayed long-term in vivo reporter gene expression for a time course of 14 days. Tacrolimus (Prograf) and Cyclosporine successfully suppressed the transplanted cell loss in animals, that obviously observed until day 8 as compared to Dexamethasone-treated and non-treated mice (day 1: 1.00E+08 (Prograf), 9.47E+07 (Cys), 5.25E+07 (Dex), and 1.25E+07 p/s/cm2/sr (control); day E+07 p/s/cm2/sr (control); day 8: 3.27E+05 (Prograf), 1.02E+05 (Cys), 6.17E+04 (Dex) and 2.73E+04 p/s/cm2/sr (control)) and continued expressing bioluminescence until day 13 ( 6.42E+05 (Prograf), 4.99E+05 (Cys), and 4.10E+04 p/s/cm2/sr. Induction of immune tolerance using pharmaceutical agents during cardio myoblast transplantation improved long-term donor cell survival in murine muscles. Optical imaging technique is capable of being used for tracking implanted stem cells in myocardium of living subjects over time

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In vitro influence of hypoxia on bioluminescence imaging in brain tumor cells  

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Bioluminescence Imaging (BLI) has been employed as an imaging modality to identify and characterize fundamental processes related to cancer development and response at cellular and molecular levels. This technique is based on the reaction of luciferin with oxygen in the presence of luciferase and ATP. A major concern in this technique is that tumors are generally hypoxic, either constitutively and/or as a result of treatment, therefore the oxygen available for the bioluminescence reaction could possibly be reduced to limiting levels, and thus leading to underestimation of the actual number of luciferase-labeled cells during in vivo procedures. In this report, we present the initial in vitro results of the oxygen dependence of the bioluminescence signal in rat gliosarcoma 9L cells tagged with the luciferase gene (9L luc cells). Bioluminescence photon emission from cells exposed to different oxygen tensions was detected by a sensitive CCD camera upon exposure to luciferin. The results showed that bioluminescence signal decreased at administered pO II levels below about 5%, falling by approximately 50% at 0.2% pO II. Additional experiments showed that changes in BLI was due to the cell inability to maintain normal levels of ATP during the hypoxic period reducing the ATP concentration to limiting levels for BLI.

Moriyama, Eduardo H.; Jarvi, Mark; Niedre, Mark; Mocanu, Joseph D.; Moriyama, Yumi; Li, Buhong; Lilge, Lothar; Wilson, Brian C.

2007-02-01

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Development of Optical Molecular Imaging System for the Acquisition of Bioluminescence Signals from Small Animals  

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Optical imaging is providing great advance and improvement in genetic and molecular imaging of animals and humans. Optical imaging system consists of optical imaging devices, which carry out major function for monitoring, tracing, and imaging in most of molecular in-vivo researches. In bio-luminescent imaging, small animals containing luciferase gene locally irradiate light, and emitted photons transmitted through skin of the small animals are imaged by using a high sensitive charged coupled device (CCD) camera. In this paper, we introduced optical imaging system for the image acquisition of bio-luminescent signals emitted from small animals. In the system, Nikon lens and four LED light sources were mounted at the inside of a dark box. A cooled CCD camera equipped with a control module was used. We tested the performance of the optical imaging system using effendorf tube and light emitting bacteria which injected intravenously into CT26 tumor bearing nude mouse. The performance of implemented optical imaging system for bio-luminescence imaging was demonstrated and the feasibility of the system in small animal imaging application was proved. We anticipate this system could be a useful tool for the molecular imaging of small animals adaptable for various experimental conditions in future

Lee, Byeong Il; Kim, Hyeon Sik; Jeong, Hye Jin; Lee, Hyung Jae; Moon, Seung Min; Kwon, Seung Young; Jeong, Shin Young; Bom, Hee Seung; Min, Jung Joon [Chonnam National University Hospital, Gwangju (Korea, Republic of); Choi, Eun Seo [Chosun University, Gwangju (Korea, Republic of)

2009-08-15

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Bioluminescence imaging of chondrocytes in rabbits by intraarticular injection of D-luciferin  

International Nuclear Information System (INIS)

Luciferase is one of the most commonly used reporter enzymes in the field of in vivo optical imaging. D-luciferin, the substrate for firefly luciferase has very high cost that allows this kind of experiment limited to small animals such as mice and rats. In this current study, we validated local injection of D-luciferin in the articular capsule for bioluminescence imaging in rabbits. Chondrocytes were cultured and infected by replication-defective adenoviral vector encoding firefly luciferase (Fluc). Chondrocytes expressing Fluc were injected or implanted in the left knee joint. The rabbits underwent optical imaging studies after local injection of D-luciferin at 1, 5, 7, 9 days after cellular administration. We sought whether optimal imaging signals was could be by a cooled CCD camera after local injection of D-luciferin. Imaging signal was not observed from the left knee joint after intraperitoneal injection of D-luciferin (15 mg/kg), whereas it was observed after intraarticular injection. Photon intensity from the left knee joint of rabbits was compared between cell injected and implanted groups after intraarticular injection of D-luciferin. During the period of imaging studies, photon intensity of the cell implanted group was 5-10 times higher than that of the cell injected group. We successfully imaged chondrocytes expressing Fluc after intraarticular injection of D-luciferin. This technique may be further applied to develop new drugs for knee joint diseaselop new drugs for knee joint disease

60

Novel registration for microcomputed tomography and bioluminescence imaging based on iterated optimal projection  

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As a high-sensitivity imaging modality, bioluminescence tomography can reconstruct the three-dimensional (3-D) location of an internal luminescent source based on the 3-D surface light distribution. However, we can only get the multi-orientation two-dimensional (2-D) bioluminescence distribution in the experiments. Therefore, developing an accurate universal registration method is essential for following bioluminescent source reconstruction. We can then map the multi-orientation 2-D bioluminescence distribution to the 3-D surface derived from anatomical information with it. We propose a 2-D -to-3-D registration method based on iterated optimal projection and applied it in a registration and reconstruction study of three transgenic mice. Compared with traditional registration methods based on the fixed points, our method was independent of the markers and the registration accuracy of the three experiments was improved by 0.3, 0.5, and 0.4 pixels, respectively. In addition, based on the above two registration results using the two registration methods, we reconstructed the 3-D location of the inner bioluminescent source in the three transgenic mice. The reconstruction results showed that the average error distance between the center of the reconstructed element and the center of the real element were reduced by 0.32, 0.48, and 0.39 mm, respectively.

Ma, Xibo; Deng, Kexin; Xue, Zhenwen; Liu, Xueyan; Zhu, Shouping; Qin, Chenghu; Yang, Xin; Tian, Jie

2013-02-01

 
 
 
 
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Uptake kinetics and biodistribution of 14C-d-luciferin - a radiolabeled substrate for the firefly luciferase catalyzed bioluminescence reaction: impact on bioluminescence based reporter gene imaging  

International Nuclear Information System (INIS)

Firefly luciferase catalyzes the oxidative decarboxylation of d-luciferin to oxyluciferin in the presence of cofactors, producing bioluminescence. This reaction is used in optical bioluminescence-based molecular imaging approaches to detect the expression of the firefly luciferase reporter gene. Biokinetics and distribution of the substrate most likely have a significant impact on levels of light signal and therefore need to be investigated. Benzene ring 14C(U)-labeled d-luciferin was utilized. Cell uptake and efflux assays, murine biodistribution, autoradiography and CCD-camera based optical bioluminescence imaging were carried out to examine the in vitro and in vivo characteristics of the tracer in cell culture and in living mice respectively. Radiolabeled and unlabeled d-luciferin revealed comparable levels of light emission when incubated with equivalent amounts of the firefly luciferase enzyme. Cell uptake assays in pCMV-luciferase-transfected cells showed slow trapping of the tracer and relatively low uptake values (up to 22.9-fold higher in firefly luciferase gene-transfected vs. nontransfected cells, p=0.0002). Biodistribution studies in living mice after tail-vein injection of 14C-d-luciferin demonstrated inhomogeneous tracer distribution with early predominant high radioactivity levels in kidneys (10.6% injected dose [ID]/g) and liver (11.9% ID/g), followed at later time points by the bladder (up to 81.3% ID/g) and small intestine (6.5%p to 81.3% ID/g) and small intestine (6.5% ID/g), reflecting the elimination routes of the tracer. Kinetics and uptake levels profoundly differed when using alternate injection routes (intravenous versus intraperitoneal). No clear trapping of 14C-d-luciferin in firefly luciferase-expressing tissues could be observed in vivo. The data obtained with 14C-d-luciferin provide insights into the dynamics of d-luciferin cell uptake, intracellular accumulation, and efflux. Results of the biodistribution and autoradiographic studies should be useful for optimizing and adapting optical imaging protocols to specific experimental settings when utilizing the firefly luciferase and d-luciferin system. (orig.)

62

Rapid and Quantitative Assessment of Cancer Treatment Response Using In Vivo Bioluminescence Imaging  

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Full Text Available Current assessment of orthotopic tumor models in animals utilizes survival as the primary therapeutic end point. In vivo bioluminescence imaging (BLI is a sensitive imaging modality that is rapid and accessible, and may comprise an ideal tool for evaluating antineoplastic therapies [1 ]. Using human tumor cell lines constitutively expressing luciferase, the kinetics of tumor growth and response to therapy have been assessed in intraperitoneal [2], subcutaneous, and intravascular [3] cancer models. However, use of this approach for evaluating orthotopic tumor models has not been demonstrated. In this report, the ability of BLI to noninvasively quantitate the growth and therapeuticinduced cell kill of orthotopic rat brain tumors derived from 9L gliosarcoma cells genetically engineered to stably express firefly luciferase (9LLuc was investigated. Intracerebral tumor burden was monitored over time by quantitation of photon emission and tumor volume using a cryogenically cooled CCD camera and magnetic resonance imaging (MRI, respectively. There was excellent correlation (r=0.91 between detected photons and tumor volume. A quantitative comparison of tumor cell kill determined from serial MRI volume measurements and BLI photon counts following 1,3-bis(2-chloroethyl-1-nitrosourea (BCNU treatment revealed that both imaging modalities yielded statistically similar cell kill values (P=.951. These results provide direct validation of BLI imaging as a powerful and quantitative tool for the assessment of antineoplastic therapies in living animals.

Alnawaz Rehemtulla

2000-01-01

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Imaging of bubonic plague dynamics by in vivo tracking of bioluminescent Yersinia pestis.  

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Yersinia pestis dissemination in a host is usually studied by enumerating bacteria in the tissues of animals sacrificed at different times. This laborious methodology gives only snapshots of the infection, as the infectious process is not synchronized. In this work we used in vivo bioluminescence imaging (BLI) to follow Y. pestis dissemination during bubonic plague. We first demonstrated that Y. pestis CO92 transformed with pGEN-luxCDABE stably emitted bioluminescence in vitro and in vivo, while retaining full virulence. The light produced from live animals allowed to delineate the infected organs and correlated with bacterial loads, thus validating the BLI tool. We then showed that the first step of the infectious process is a bacterial multiplication at the injection site (linea alba), followed by a colonization of the draining inguinal lymph node(s), and subsequently of the ipsilateral axillary lymph node through a direct connection between the two nodes. A mild bacteremia and an effective filtering of the blood stream by the liver and spleen probably accounted for the early bacterial blood clearance and the simultaneous development of bacterial foci within these organs. The saturation of the filtering capacity of the spleen and liver subsequently led to terminal septicemia. Our results also indicate that secondary lymphoid tissues are the main targets of Y. pestis multiplication and that colonization of other organs occurs essentially at the terminal phase of the disease. Finally, our analysis reveals that the high variability in the kinetics of infection is attributable to the time the bacteria remain confined at the injection site. However, once Y. pestis has reached the draining lymph nodes, the disease progresses extremely rapidly, leading to the invasion of the entire body within two days and to death of the animals. This highlights the extraordinary capacity of Y. pestis to annihilate the host innate immune response. PMID:22496846

Nham, Toan; Filali, Sofia; Danne, Camille; Derbise, Anne; Carniel, Elisabeth

2012-01-01

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Non-invasive visualisation of the development of peritoneal carcinomatosis and tumour regression after 213Bi-radioimmunotherapy using bioluminescence imaging  

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Non-invasive imaging of tumour development remains a challenge, especially for tumours in the intraperitoneal cavity. Therefore, the aim of this study was the visualisation of both the development of peritoneal carcinomatosis and tumour regression after radioimmunotherapy with tumour-specific 213Bi-Immunoconjugates, via in vivo bioluminescence imaging of firefly luciferase-transfected cells. Human diffuse-type gastric cancer cells expressing mutant d9-E-cadherin were stably transfected with firefly luciferase (HSC45-M2-luc). For bioluminescence imaging, nude mice were inoculated intraperitoneally with 1 x 107 HSC45-M2-luc cells. On days 4 and 8 after tumour cell inoculation, imaging was performed following D-luciferin injection using a cooled CCD camera with an image intensifier unit. For therapy, mice were injected with 2.7 MBq 213Bi-d9MAb targeting d9-E-cadherin on day 8 after tumour cell inoculation. Bioluminescence images were taken every 4 days to monitor tumour development. After i.p. inoculation of HSC45-M2-luc cells into nude mice, development as well as localisation of peritoneal carcinomatosis could be visualised using bioluminescence imaging. Following 213Bi-d9MAb therapy on day 8 after intraperitoneal inoculation of HSC45-M2-luc cells, small tumour nodules were totally eliminated and larger nodules showed a clear reduction in size on day 12 after tumour cell inoculation. Subsequently a recurrence of tumour mass wSubsequently a recurrence of tumour mass was observed, starting from the remaining tumour spots. By measuring the mean grey level intensity, tumour development over time could be demonstrated. Non-invasive bioluminescence imaging permits visualisation of the development of peritoneal carcinomatosis, localisation of tumour in the intraperitoneal cavity and evaluation of therapeutic success after 213Bi-d9MAb treatment. (orig.)

65

Non-invasive visualisation of the development of peritoneal carcinomatosis and tumour regression after {sup 213}Bi-radioimmunotherapy using bioluminescence imaging  

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Non-invasive imaging of tumour development remains a challenge, especially for tumours in the intraperitoneal cavity. Therefore, the aim of this study was the visualisation of both the development of peritoneal carcinomatosis and tumour regression after radioimmunotherapy with tumour-specific {sup 213}Bi-Immunoconjugates, via in vivo bioluminescence imaging of firefly luciferase-transfected cells. Human diffuse-type gastric cancer cells expressing mutant d9-E-cadherin were stably transfected with firefly luciferase (HSC45-M2-luc). For bioluminescence imaging, nude mice were inoculated intraperitoneally with 1 x 10{sup 7} HSC45-M2-luc cells. On days 4 and 8 after tumour cell inoculation, imaging was performed following D-luciferin injection using a cooled CCD camera with an image intensifier unit. For therapy, mice were injected with 2.7 MBq {sup 213}Bi-d9MAb targeting d9-E-cadherin on day 8 after tumour cell inoculation. Bioluminescence images were taken every 4 days to monitor tumour development. After i.p. inoculation of HSC45-M2-luc cells into nude mice, development as well as localisation of peritoneal carcinomatosis could be visualised using bioluminescence imaging. Following {sup 213}Bi-d9MAb therapy on day 8 after intraperitoneal inoculation of HSC45-M2-luc cells, small tumour nodules were totally eliminated and larger nodules showed a clear reduction in size on day 12 after tumour cell inoculation. Subsequently a recurrence of tumour mass was observed, starting from the remaining tumour spots. By measuring the mean grey level intensity, tumour development over time could be demonstrated. Non-invasive bioluminescence imaging permits visualisation of the development of peritoneal carcinomatosis, localisation of tumour in the intraperitoneal cavity and evaluation of therapeutic success after {sup 213}Bi-d9MAb treatment. (orig.)

Buchhorn, H. Matthias; Seidl, Christof; Beck, Roswitha; Schwaiger, Markus [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Saur, Dieter [Technische Universitaet Muenchen, Department of Internal Medicine 2, Munich (Germany); Apostolidis, Christos; Morgenstern, Alfred [Institute for Transuranium Elements, European Commission, Joint Research Centre, Karlsruhe (Germany); Senekowitsch-Schmidtke, Reingard [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Technische Universitaet Muenchen, Nuklearmedizinische Klinik, Klinikum r. d. Isar, Muenchen (Germany)

2007-06-15

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Bioluminescent imaging: a critical tool in pre-clinical oncology research.  

LENUS (Irish Health Repository)

Bioluminescent imaging (BLI) is a non-invasive imaging modality widely used in the field of pre-clinical oncology research. Imaging of small animal tumour models using BLI involves the generation of light by luciferase-expressing cells in the animal following administration of substrate. This light may be imaged using an external detector. The technique allows a variety of tumour-associated properties to be visualized dynamically in living models. The increasing use of BLI as a small-animal imaging modality has led to advances in the development of xenogeneic, orthotopic, and genetically engineered animal models expressing luciferase genes. This review aims to provide insight into the principles of BLI and its applications in cancer research. Many studies to assess tumour growth and development, as well as efficacy of candidate therapeutics, have been performed using BLI. More recently, advances have also been made using bioluminescent imaging in studies of protein-protein interactions, genetic screening, cell-cycle regulators, and spontaneous cancer development. Such novel studies highlight the versatility and potential of bioluminescent imaging in future oncological research.

O'Neill, Karen

2010-02-01

67

Bioluminescence imaging in a medium-sized animal by local injection of d-luciferin  

International Nuclear Information System (INIS)

Luciferase is one of the most commonly used reporter enzymes in the field of molecular imaging. D-luciferin is known as the substrate for luciferase enzyme and its cost is very expensive. Therefore, the bioluminescence molecular imaging study has been allowed in small animals such as mice and rats. In this current study, we validated local injection of D-luciferin in articular capsule for bioluminescence imaging in rabbits. Chondrocytes were cultured and infected by replication-defective adenoviral vector encoding firefly luciferase. And then was performed different method of chondrocyte cell injection and transplantation into the knee of rabbits. The rabbits underwent imaging by cooled CCD camera after local injection of D-luciferin (3mg) into experimental knee joint as well as contralateral normal knee joint on days 1, 5, 7, 9. We sought whether optimal imaging signal was acquired by using cooled CCD camera after local injection of D-luciferin. We successfully visualized injected or transplanted cells in knee joint by local injection of D-luciferin. Total photon flux (7.86E+08 p/s/cm2/sr) from the knee joint transplanted with cells approximately increased 10-fold more than (9.43E+07p/s/cm2/sr) that from injected knee joints until 7 day. Imaging signal was observed in transplanted joints until day 9 after surgery while signal from injected knee was observed by day 7 after injection. We successfully carried out bioluminescence imaging study with ed out bioluminescence imaging study with medium sized animal by local injection of small amount of D-luciferin. Survival of chondrocytes were prolonged when surgically transplanted in joints than when directly injected in joint space

68

In vivo bioluminescence imaging study to monitor ectopic bone formation by luciferase gene marked mesenchymal stem cells  

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Mesenchymal stem cells (MSCs) represent a powerful tool for applications in regenerative medicine. In this study, we used in vivo bioluminescence imaging to noninvasively investigate the fate and the contribution to bone formation of adult MSCs in tissue engineered constructs. Goat MSCs expressing GFP-luciferase were seeded on ceramic scaffolds and implanted subcutaneously in immune-deficient mice. The constructs were monitored weekly with bioluminescence imaging and were retrieved after 7 we...

Olivo, C.; Alblas, J.; Verweij, V. G. M.; Zonneveld, A. J.; Dhert, W. J. A.; Martens, A. C. M.

2008-01-01

69

Bioluminescence imaging to track bacterial dissemination of Yersinia pestis using different routes of infection in mice  

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Full Text Available Abstract Background Plague is caused by Yersinia pestis, a bacterium that disseminates inside of the host at remarkably high rates. Plague bacilli disrupt normal immune responses in the host allowing for systematic spread that is fatal if left untreated. How Y. pestis disseminates from the site of infection to deeper tissues is unknown. Dissemination studies for plague are typically performed in mice by determining the bacterial burden in specific organs at various time points. To follow bacterial dissemination during plague infections in mice we tested the possibility of using bioluminescence imaging (BLI, an alternative non-invasive approach. Fully virulent Y. pestis was transformed with a plasmid containing the luxCDABE genes, making it able to produce light; this lux-expressing strain was used to infect mice by subcutaneous, intradermal or intranasal inoculation. Results We successfully obtained images from infected animals and were able to follow bacterial dissemination over time for each of the three different routes of inoculation. We also compared the radiance signal from animals infected with a wild type strain and a ?caf1?psaA mutant that we previously showed to be attenuated in colonization of the lymph node and systemic dissemination. Radiance signals from mice infected with the wild type strain were larger than values obtained from mice infected with the mutant strain (linear regression of normalized values, P? Conclusions We demonstrate that BLI is useful for monitoring dissemination from multiple inoculation sites, and for characterization of mutants with defects in colonization or dissemination.

Gonzalez Rodrigo J

2012-07-01

70

Construction of a bioluminescence reporter plasmid for Francisella tularensis  

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A Francisella tularensis shuttle vector that constitutively expresses the Photorhabdus luminescens lux operon in type A and type B strains of F. tularensis was constructed. The bioluminescence reporter plasmid was introduced into the live vaccine strain of F. tularensis and used to follow F. tularensis growth in a murine intranasal challenge model in real time by bioluminescence imaging. The results show that the new bioluminescence reporter plasmid represents a useful tool for tularemia rese...

Bina, Xiaowen R.; Miller, Mark A.; Bina, James E.

2010-01-01

71

Self-calibrated algorithms for diffuse optical tomography and bioluminescence tomography using relative transmission images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Reconstruction algorithms for diffuse optical tomography (DOT) and bioluminescence tomography (BLT) have been developed based on diffusion theory. The algorithms numerically solve the diffusion equation using the finite element method. The direct measurements of the uncalibrated light fluence rates by a camera are used for the reconstructions. The DOT is self-calibrated by using all possible pairs of transmission images obtained with external sources along with the relative val...

Naser, Mohamed A.; Patterson, Michael S.; Wong, John W.

2012-01-01

72

In vivo Bioluminescence Imaging of Burkholderia mallei Respiratory Infection and Treatment in the Mouse Model  

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Bioluminescent imaging (BLI) technology is a powerful tool for monitoring infectious disease progression and treatment approaches. BLI is particularly useful for tracking fastidious intracellular pathogens that might be difficult to recover from certain organs. Burkholderia mallei, the causative agent of glanders, is a facultative intracellular pathogen and has been classified by the CDC as a Category B select agent due to its highly infectious nature and potential use as a biological weapon....

Massey, Shane; Johnston, Katie; Mott, Tiffany M.; Judy, Barbara M.; Kvitko, Brian H.; Schweizer, Herbert P.; Estes, D. Mark; Torres, Alfredo G.

2011-01-01

73

Efficacy assessment of sustained intraperitoneal paclitaxel therapy in a murine model of ovarian cancer using bioluminescent imaging  

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We evaluated the pre-clinical efficacy of a novel intraperitoneal (i.p.) sustained-release paclitaxel formulation (PTXePC) using bioluminescent imaging (BLI) in the treatment of ovarian cancer. Human ovarian carcinoma cells stably expressing the firefly luciferase gene (SKOV3Luc) were injected i.p. into SCID mice. Tumour growth was evaluated during sustained or intermittent courses of i.p. treatment with paclitaxel (PTX). In vitro bioluminescence strongly correlated with cell survival and cyt...

Vassileva, V.; Moriyama, E. H.; Souza, R.; Grant, J.; Allen, C. J.; Wilson, B. C.; Piquette-miller, M.

2008-01-01

74

Bioluminescence imaging of leukemia cell lines in vitro and in mouse xenografts: effects of monoclonal and polyclonal cell populations on intensity and kinetics of photon emission  

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Full Text Available Abstract Background We investigated the utility of bioluminescence imaging (BLI using firefly luciferase in monoclonal and polyclonal populations of leukemia cells in vitro and in vivo. Methods Monoclonal and polyclonal human lymphoid and myeloid leukemia cell lines transduced with firefly luciferase were used for BLI. Results Kinetics and dynamics of bioluminescence signal were cell line dependent. Luciferase expression decreased significantly over time in polyclonal leukemia cells in vitro. Transplantation of polyclonal luciferase-tagged cells in mice resulted in inconsistent signal intensity. After selection of monoclonal cell populations, luciferase activity was stable, equal kinetic and dynamic of bioluminescence intensity and strong correlation between cell number and light emission in vitro were observed. We obtained an equal development of leukemia burden detected by luciferase activity in NOD-scid-gamma mice after transplantation of monoclonal populations. Conclusion The use of monoclonal leukemia cells selected for stable and equal luciferase activity is recommended for experiments in vitro and xenograft mouse models. The findings are highly significant for bioluminescence imaging focused on pre-clinical drug development.

Christoph Sandra

2013-01-01

75

A bioluminescence imaging based in vivo model for preclinical testing of novel cellular immunotherapy strategies to improve the graft-versus-myeloma effect.  

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Background: The development and preclinical testing of novel immunotherapy strategies for multiple myeloma can benefit substantially from a humanized animal model that enables quantitative real-time monitoring of tumor progression. Here we have explored the feasibility of establishing such a model in immunodeficient RAG2–/–c–/– mice, by utilizing non-invasive bioluminescent imaging for real-time monitoring of multiple myeloma cell growth. Design and Methods: Seven multiple myelom...

Rozemuller, H.; Spek, E.; Bogers-boer, L. H.; Zwart, M. C.; Verweij, V. G. M.; Emmelot, M. E.; Groen, R. W.; Spaapen, R. M.; Bloem, A. C.; Lokhorst, H. M.; Mutis, T.; Martens, A. C. M.

2008-01-01

76

Bioluminescence imaging study of spatial and temporal persistence of Lactobacillus plantarum and Lactococcus lactis in living mice.  

Science.gov (United States)

Lactic acid bacteria, especially lactobacilli, are common inhabitants of the gastrointestinal tract of mammals, for which they have received considerable attention due to their putative health-promoting properties. In this study, we describe the development and application of luciferase-expressing Lactobacillus plantarum and Lactococcus lactis strains for noninvasive in vivo monitoring in the digestive tract of mice. We report for the first time the functional in vitro expression in Lactobacillus plantarum NCIMB8826 and in Lactococcus lactis MG1363 of the click beetle luciferase (CBluc), as well as Gaussia and bacterial luciferases, using a combination of vectors, promoters, and codon-optimized genes. We demonstrate that a CBluc construction is the best-performing luciferase system for the noninvasive in vivo detection of lactic acid bacteria after oral administration. The persistence and viability of both strains was studied by bioluminescence imaging in anesthetized mice and in mouse feces. In vivo bioluminescence imaging confirmed that after a single or multiple oral administrations, L. lactis has shorter survival times in the mouse gastrointestinal tract than L. plantarum, and it also revealed the precise gut compartments where both strains persisted. The application of luciferase-labeled bacteria has significant potential to allow the in vivo and ex vivo study of the interactions of lactic acid bacteria with their mammalian host. PMID:23204409

Daniel, Catherine; Poiret, Sabine; Dennin, Véronique; Boutillier, Denise; Pot, Bruno

2013-02-01

77

Investigating real-time activation of adenosine receptors by bioluminescence resonance energy transfer technique  

Science.gov (United States)

Adenosine receptors play important roles in many physiological and pathological processes, for example regulating myocardial oxygen consumption and the release of neurotransmitters. The activations of adenosine receptors have been studied by some kinds of techniques, such as western blot, immunohistochemistry, etc. However, these techniques cannot reveal the dynamical response of adenosine receptors under stimulation. In this paper, bioluminescence resonance energy transfer technique was introduced to study the real-time activation of adenosine receptors by monitoring the dynamics of cyclic adenosine monophosphate (cAMP) level. The results showed that there were significant differences between adenosine receptors on real-time responses under stimulation. Moreover, the dynamics of cAMP level demonstrated that competition between adenosine receptors existed. Taken together, our study indicates that monitoring the dynamics of cAMP level using bioluminescence resonance energy transfer technique could be one potential approach to investigate the mechanism of competitions between adenosine receptors.

Huang, Yimei; Yang, Hongqin; Zheng, Liqin; Chen, Jiangxu; Wang, Yuhua; Li, Hui; Xie, Shusen

2013-02-01

78

Quantification of bioluminescence images of point source objects using diffusion theory models  

International Nuclear Information System (INIS)

A simple approach for estimating the location and power of a bioluminescent point source inside tissue is reported. The strategy consists of using a diffuse reflectance image at the emission wavelength to determine the optical properties of the tissue. Following this, bioluminescence images are modelled using a single point source and the optical properties from the reflectance image, and the depth and power are iteratively adjusted to find the best agreement with the experimental image. The forward models for light propagation are based on the diffusion approximation, with appropriate boundary conditions. The method was tested using Monte Carlo simulations, Intralipid tissue-simulating phantoms and ex vivo chicken muscle. Monte Carlo data showed that depth could be recovered within 6% for depth 4-12 mm, and the corresponding relative source power within 12%. In Intralipid, the depth could be estimated within 8% for depth 4-12 mm, and the relative source power, within 20%. For ex vivo tissue samples, source depths of 4.5 and 10 mm and their relative powers were correctly identified

79

In Vivo Bioluminescent Imaging (BLI: Noninvasive Visualization and Interrogation of Biological Processes in Living Animals  

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Full Text Available In vivo bioluminescent imaging (BLI is increasingly being utilized as a method for modern biological research. This process, which involves the noninvasive interrogation of living animals using light emitted from luciferase-expressing bioreporter cells, has been applied to study a wide range of biomolecular functions such as gene function, drug discovery and development, cellular trafficking, protein-protein interactions, and especially tumorigenesis, cancer treatment, and disease progression. This article will review the various bioreporter/biosensor integrations of BLI and discuss how BLI is being applied towards a new visual understanding of biological processes within the living organism.

Steven Ripp

2010-12-01

80

Frequency domain 3D simplified spherical harmonics approximation: development, validation, and implication in bioluminescence imaging  

Science.gov (United States)

A three dimensional (3D) photon transport model has been developed based on the frequency domain simplified spherical harmonics approximation (SPN) to the Radiative Transport Equation. Based on preliminary Monte Carlo studies, it is shown that for problems exhibiting strong absorption, the solutions using the 7th order SPN model (N = 7) are significantly more accurate than those from a standard Diffusion (SP1) based solver. This advance is of particular interest in the field of bioluminescent imaging where the peak emission of light emitting molecular markers are closer to the visible range (500 - 650 nm) corresponding to strong absorption due to hemoglobin.

Chu, M.; Klose, A. D.; Styles, I. B.; Vishwanath, K.; Dehghani, H.

2009-02-01

 
 
 
 
81

Bioluminescence imaging of cord blood derived mesenchymal stem cell transplanatation into myocardium  

International Nuclear Information System (INIS)

The conventional method of analyzing myocardial cell transplanation relies on postmortem histology. We sought to demonstrate the feasibility of longitudinal monitoring transplanted cell survival in living animals using optical imaging techniques. Umblical cord blood was collected upon delivery with informed consent. Umblical mononuclear cells were obtained by negative immuno-depletion of CD3, CD14, CD19, CD38, CD66b, and glycophorin- A positive cells, followed by Ficoll- Paque density gradient centrifugation, and plated in non-coated tissue culture flasks in expansion medium. Cells were allowed to adhere overnight, thereafter non-adherent cells were washed out with medium changes. After getting the MSCs, they were transfected [multiplicity of infection (MOl) = 40) with Ad-CMV-Fluc overnight. Rats (n=4) underwent intramyocardial injection of 5 x 105 MSCs expressing firefly luciferase (Fluc) reporter gene. Optical bioluminescence imaging was performed using the charged-coupled device camera (Xenogen) from the 1st day of transplantion. Cardiac bioluminescence signals were present from 2nd day of transplantation. Cardiac signals were clearly present at day 2 (9.2x103p/s/cm2/sr). The signal reduced from day 3. The locations, magnitude, and survival duration of cord blood derived MSCs were monitored noninvasively. With further development, molecular imaging studies should add critical insights into cardiac cell transplantationardiac cell transplantation

82

Bioluminescence imaging reveals dynamics of beta cell loss in the non-obese diabetic (NOD) mouse model.  

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We generated a mouse model (MIP-Luc-VU-NOD) that enables non-invasive bioluminescence imaging (BLI) of beta cell loss during the progression of autoimmune diabetes and determined the relationship between BLI and disease progression. MIP-Luc-VU-NOD mice displayed insulitis and a decline in bioluminescence with age which correlated with beta cell mass, plasma insulin, and pancreatic insulin content. Bioluminescence declined gradually in female MIP-Luc-VU-NOD mice, reaching less than 50% of the initial BLI at 10 weeks of age, whereas hyperglycemia did not ensue until mice were at least 16 weeks old. Mice that did not become diabetic maintained insulin secretion and had less of a decline in bioluminescence than mice that became diabetic. Bioluminescence measurements predicted a decline in beta cell mass prior to the onset of hyperglycemia and tracked beta cell loss. This model should be useful for investigating the fundamental processes underlying autoimmune diabetes and developing new therapies targeting beta cell protection and regeneration. PMID:23483929

Virostko, John; Radhika, Armandla; Poffenberger, Greg; Dula, Adrienne N; Moore, Daniel J; Powers, Alvin C

2013-01-01

83

A Multi-Enzyme Bioluminescent Time-Resolved Pyrophosphate Assay  

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We have developed a high-sensitivity assay for measurement of inorganic pyrophosphate (PPi) in adenosine 5?-triphosphate (ATP) contaminated samples. The assay is based on time-resolved measurements of the luminescence kinetics and implements multiple enzymes to convert PPi to ATP that is, in turn, utilized to produce light; and to hydrolyze PPi for measurement of the steady-state background luminescence. A theoretical model for describing luminescence kinetics and optimizing composition of ...

Sun, Ye; Jacobson, K. Bruce; Golovlev, Val

2007-01-01

84

Use of a highly sensitive two-dimensional luminescence imaging system to monitor endogenous bioluminescence in plant leaves  

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Abstract Background All living organisms emit spontaneous low-level bioluminescence, which can be increased in response to stress. Methods for imaging this ultra-weak luminescence have previously been limited by the sensitivity of the detection systems used. Results We developed a novel configuration of a cooled charge-coupled device (CCD) for 2-dimensional imaging of light emission from biological material. In this study, we imaged photon emission from plant le...

Flor-Henry Michel; McCabe Tulene C; de Bruxelles Guy L; Roberts Michael R

2004-01-01

85

The Bioluminescence Web Page  

Science.gov (United States)

Bioluminescence is "simply light produced by a chemical reaction which originates in an organism." This Web sitefrom the University of California at Santa Barbara intends to provide a reliable source of information on this somewhat obscure subject. The site contains a lot of basic information about the chemistry of bioluminescence and specific bioluminescent organisms, along with some fabulous images. More specific information can be obtained through research abstracts and citations posted in the Research Forum and recently added workshop section. This is an attractive site that will appeal to a wide variety of audiences.

2002-01-01

86

Assessing the effect of EPO on tumor oxygenation and radioresponsiveness via in vivo bioluminescence imaging  

International Nuclear Information System (INIS)

Evaluating tumor kill by volume measurement lacks sensitivity while in vivo-in vitro and histological assays are unsuitable for serial measurements. In vivo bioluminescence imaging (BI) nondestructively measures the number of metabolically active cells containing luciferase (LUC) over time. In this paper, the effect of erythropoietin (EPO) on tumor oxygenation and radioresponsivenessis is studied using BI and conventional methods. Murine adenocarcinoma cells, transfected with the LUC gene, were placed in the flank of BALB/C mice. EPO 1 u/g or saline was injected sc tiw for two weeks, starting the day of transplant. Mice then underwent irradiation (XRT) or pO2 measurement with an optical probe. In BI, mice were injected with luciferin and total photon flux (TPF) measured with a CCD camera. In vitro, cells were plated, irradiated and incubated at 37 deg C. Initial hematocrit was 47% (n=119) vs. 61% in EPO-treated mice (n=23, p2 (6.4 vs. 4.7 mm Hg, p=0.04) than controls. For 1-3x7 Gy, TPF was stable for 2 days after the start of XRT, then fell precipitously. Two weeks post XRT, TPF was 10-5 the initial value and a nidus of LUC activity persisted for months in most tumors. Tumor volume decreased only 1-2 orders of magnitude. For 3x7 Gy, tumor regrew in 1/11 EPO-TM and controls (p=NS.) For 1x7 Gy, tumors regrew in 4/6 EPO-TM and 2/4 controls (p=NS). TPF did not increase with tumor re(p=NS). TPF did not increase with tumor regrowth. Recurrent tumors exhibited lower median pO2 (2.1 mm Hg, p=.003) and higher hypoxic fraction than controls. A clonogenic assay yielded D10 = 3.7 Gy with all colonies expressing LUC. The TPF of 0-Gy treated wells rose significantly over incubation, while that of wells treated to 10 Gy was unchanged. Though EPO improved tumor oxygenation, no effect on XRT-mediated cell kill was seen. BI measured tumor killing in vivo over a broad dynamic range. The results suggest that cell killing in vivo is a multistep process, amplified by humoral factors

87

Self-illuminating in vivo lymphatic imaging using a bioluminescence resonance energy transfer quantum dot nano-particle  

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Autofluorescence arising from normal tissues can compromise the sensitivity and specificity of in vivo fluorescence imaging by lowering the target-to-background signal ratio. Since bioluminescence resonance energy transfer quantum dot (BRET-QDot) nano-particles can self-illuminate in near-infrared in the presence of the substrate, coelenterazine, without irradiating excitation lights, imaging using BRET-QDots does not produce any autofluorescence. In this study, we applied this BRET-QDot nano...

Kosaka, Nobuyuki; Mitsunaga, Makoto; Bhattacharyya, Sukanta; Miller, Steven C.; Choyke, Peter L.; Kobayashi, Hisataka

2011-01-01

88

Tomographic bioluminescence imaging by use of a combined optical-PET (OPET) system: a computer simulation feasibility study  

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The feasibility and limits in performing tomographic bioluminescence imaging with a combined optical-PET (OPET) system was explored by simulating its image formation process. A micro-MRI based virtual mouse phantom was assigned appropriate tissue optical properties to each of its segmented internal organs at wavelengths spanning the emission spectrum of the firefly luciferase at 37 °C. The TOAST finite-element code was employed to simulate the diffuse transport of photons emitted from biolum...

Alexandrakis, George; Rannou, Fernando R.; Chatziioannou, Arion F.

2005-01-01

89

Fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography  

International Nuclear Information System (INIS)

We investigate fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography for applications in small animal imaging. Our forward model uses a diffusion approximation for optically inhomogeneous tissue, which we solve using a finite element method (FEM). We examine two approaches to incorporating the forward model into the solution of the inverse problem. In a conventional direct calculation approach one computes the full forward model by repeated solution of the FEM problem, once for each potential source location. We describe an alternative on-the-fly approach where one does not explicitly solve for the full forward model. Instead, the solution to the forward problem is included implicitly in the formulation of the inverse problem, and the FEM problem is solved at each iteration for the current image estimate. We evaluate the convergence speeds of several representative iterative algorithms. We compare the computation cost of those two approaches, concluding that the on-the-fly approach can lead to substantial reductions in total cost when combined with a rapidly converging iterative algorithm

90

Metabolic imaging in microregions of tumors and normal tissues with bioluminescence and photon counting  

International Nuclear Information System (INIS)

A method has been developed for metabolic imaging on a microscopic level in tumors, tumor spheroids, and normal tissues. The technique makes it possible to determine the spatial distribution of glucose, lactate, and ATP in absolute terms at similar locations within tissues or cell aggregates. The substrate distributions are registered in serial cryostat sections from tissue cryobiopsies or from frozen spheroids with the use of bioluminescence reactions. The light emission is measured directly by a special imaging photon counting system enabling on-line image analysis. The technique has been applied to human breast cancer xenografts, to spheroids originating from a human colon adenocarcinoma, and to skeletal rat muscle. Preliminary data obtained indicate that heterogeneities in the substrate distributions measured are much more pronounced in tumors than in normal tissue. There was no obvious correlation among the three quantities measured at similar locations within the tissues. The distribution of ATP corresponded well with the histological structure of larger spheroids; values were low in the necrotic center and high in the viable rim of these cell aggregates

91

Physicochemical characterization and in vivo bioluminescence imaging of nanostructured lipid carriers for targeting the brain: apomorphine as a model drug  

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Nanostructured lipid carriers (NLCs) were prepared to investigate whether the duration of brain targeting and accumulation of drugs in the brain can be improved by intravenous delivery. NLCs were developed using cetyl palmitate as the lipid matrix, squalene as the cationic surfactant, and Pluronic F68, polysorbate 80 and polyethylene glycol as the interfacial additives. Solid lipid nanoparticles (SLNs) and lipid emulsions (LEs) were also prepared for comparison. An anti-Parkinson's drug, apomorphine, was used as the model drug. Nuclear magnetic resonance and differential scanning calorimetry showed possible interactions between the solid and liquid lipids in the inner core. The lipid nanoparticles with different compositions were characterized by mean size, zeta potential, apomorphine encapsulation and in vitro drug release. NLCs were 370-430 nm in size, which was between the sizes of the SLNs and LEs. A cationic surfactant was used to produce a positive surface charge of 42-50 mV. The base form of apomorphine was successfully entrapped by NLCs with an entrapment percentage of > 60%. The loading of apomorphine in nanoparticles resulted in a slower release behavior compared to the aqueous solution, with LEs showing the lowest release. In vivo real-time bioluminescence imaging of the rat brain revealed that NLCs could be targeted, through certain vessels, to selected brain regions. This effect was further confirmed by imaging the entire brain and brain slices. The results indicated that NLCs with moderate additives are a promising controlled-release and drug-targeting system.

Hsu, Shu-Hui; Wen, Chih-Jen; Al-Suwayeh, S. A.; Chang, Hui-Wen; Yen, Tzu-Chen; Fang, Jia-You

2010-10-01

92

Physicochemical characterization and in vivo bioluminescence imaging of nanostructured lipid carriers for targeting the brain: apomorphine as a model drug  

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Nanostructured lipid carriers (NLCs) were prepared to investigate whether the duration of brain targeting and accumulation of drugs in the brain can be improved by intravenous delivery. NLCs were developed using cetyl palmitate as the lipid matrix, squalene as the cationic surfactant, and Pluronic F68, polysorbate 80 and polyethylene glycol as the interfacial additives. Solid lipid nanoparticles (SLNs) and lipid emulsions (LEs) were also prepared for comparison. An anti-Parkinson's drug, apomorphine, was used as the model drug. Nuclear magnetic resonance and differential scanning calorimetry showed possible interactions between the solid and liquid lipids in the inner core. The lipid nanoparticles with different compositions were characterized by mean size, zeta potential, apomorphine encapsulation and in vitro drug release. NLCs were 370-430 nm in size, which was between the sizes of the SLNs and LEs. A cationic surfactant was used to produce a positive surface charge of 42-50 mV. The base form of apomorphine was successfully entrapped by NLCs with an entrapment percentage of > 60%. The loading of apomorphine in nanoparticles resulted in a slower release behavior compared to the aqueous solution, with LEs showing the lowest release. In vivo real-time bioluminescence imaging of the rat brain revealed that NLCs could be targeted, through certain vessels, to selected brain regions. This effect was further confirmed by imaging the entire brain and brain slices. The results indicated that NLCs with moderate additives are a promising controlled-release and drug-targeting system.

Hsu, Shu-Hui [Department of Pharmacy, Chia Nan University of Pharmacy and Science, Tainan 717, Taiwan (China); Wen, Chih-Jen; Yen, Tzu-Chen [Animal Molecular Imaging Center, Chang Gung Memorial Hospital, Kweishan, Taoyuan 333, Taiwan (China); Al-Suwayeh, S A; Fang, Jia-You [Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh (Saudi Arabia); Chang, Hui-Wen, E-mail: fajy@mail.cgu.edu.tw [Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China)

2010-10-08

93

Bioluminescence imaging to monitor the in vivo distribution of administered mesenchymal stem cells in acute kidney injury  

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Effective and targeted delivery of cells to injured organs is critical to the development of cell therapies. However, currently available in vivo cell tracking methods still lack sufficient sensitivity and specificity. We examined, therefore, whether a highly sensitive and specific bioluminescence method is suitable to noninvasively image the organ distribution of administered mesenchymal stem cells (MSCs) in vivo. MSCs were transfected with a luciferase/neomycin phosphotransferase construct ...

To?gel, Florian; Yang, Ying; Zhang, Ping; Hu, Zhuma; Westenfelder, Christof

2008-01-01

94

In vivo Bioluminescence Imaging of Tumor Hypoxia Dynamics of Breast Cancer Brain Metastasis in a Mouse Model  

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It is well recognized that tumor hypoxia plays an important role in promoting malignant progression and affecting therapeutic response negatively. There is little knowledge about in situ, in vivo, tumor hypoxia during intracranial development of malignant brain tumors because of lack of efficient means to monitor it in these deep-seated orthotopic tumors. Bioluminescence imaging (BLI), based on the detection of light emitted by living cells expressing a luciferase gene, has been rapidly adopt...

Saha, Debabrata; Dunn, Henry; Zhou, Heling; Harada, Hiroshi; Hiraoka, Masahiro; Mason, Ralph P.; Zhao, Dawen

2011-01-01

95

5-Fluorouracil Induced Intestinal Mucositis via Nuclear Factor-?B Activation by Transcriptomic Analysis and In Vivo Bioluminescence Imaging  

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5-Fluorouracil (5-FU) is a commonly used drug for the treatment of malignant cancers. However, approximately 80% of patients undergoing 5-FU treatment suffer from gastrointestinal mucositis. The aim of this report was to identify the drug target for the 5-FU-induced intestinal mucositis. 5-FU-induced intestinal mucositis was established by intraperitoneally administering mice with 100 mg/kg 5-FU. Network analysis of gene expression profile and bioluminescent imaging were applied to identify t...

Chang, Chung-ta; Ho, Tin-yun; Lin, Ho; Liang, Ji-an; Huang, Hui-chi; Li, Chia-cheng; Lo, Hsin-yi; Wu, Shih-lu; Huang, Yi-fang; Hsiang, Chien-yun

2012-01-01

96

Multicolor bioluminescence boosts malaria research: quantitative dual-color assay and single-cell imaging in Plasmodium falciparum parasites.  

Science.gov (United States)

New reliable and cost-effective antimalarial drug screening assays are urgently needed to identify drugs acting on different stages of the parasite Plasmodium falciparum, and particularly those responsible for human-to-mosquito transmission, that is, the P. falciparum gametocytes. Low Z' factors, narrow dynamic ranges, and/or extended assay times are commonly reported in current gametocyte assays measuring gametocyte-expressed fluorescent or luciferase reporters, endogenous ATP levels, activity of gametocyte enzymes, or redox-dependent dye fluorescence. We hereby report on a dual-luciferase gametocyte assay with immature and mature P. falciparum gametocyte stages expressing red and green-emitting luciferases from Pyrophorus plagiophthalamus under the control of the parasite sexual stage-specific pfs16 gene promoter. The assay was validated with reference antimalarial drugs and allowed to quantitatively and simultaneously measure stage-specific drug effects on parasites at different developmental stages. The optimized assay, requiring only 48 h incubation with drugs and using a cost-effective luminogenic substrate, significantly reduces assay cost and time in comparison to state-of-the-art analogous assays. The assay had a Z' factor of 0.71 ± 0.03, and it is suitable for implementation in 96- and 384-well microplate formats. Moreover, the use of a nonlysing D-luciferin substrate significantly improved the reliability of the assay and allowed one to perform, for the first time, P. falciparum bioluminescence imaging at single-cell level. PMID:25102353

Cevenini, Luca; Camarda, Grazia; Michelini, Elisa; Siciliano, Giulia; Calabretta, Maria Maddalena; Bona, Roberta; Kumar, T R Santha; Cara, Andrea; Branchini, Bruce R; Fidock, David A; Roda, Aldo; Alano, Pietro

2014-09-01

97

In Vivo Bioluminescence Imaging of Inducible Nitric Oxide Synthase Gene Expression in Vascular Inflammation  

Science.gov (United States)

Purpose Inflammation plays a critical role in atherosclerosis and is associated with upregulation of inducible nitric oxide synthase (iNOS). We studied bioluminescence imaging (BLI) to track iNOS gene expression in a murine model of vascular inflammation. Procedures Macrophage-rich vascular lesions were induced by carotid ligation plus high-fat diet and streptozotocin-induced diabetes in 18 iNOS-luc reporter mice. In vivo iNOS expression was imaged serially by BLI over 14 days, followed by in situ BLI and histology. Results BLI signal from ligated carotids increased over 14 days (9.7±4.4×103 vs. 4.4±1.7×103 photons/s/cm2/sr at baseline, piNOS and luciferase expression, only in ligated left carotid arteries and not controls. Conclusions BLI allows in vivo detection of iNOS expression in murine carotid lesions and may provide a valuable approach for monitoring vascular gene expression and inflammation in small animal models. PMID:21057879

Terashima, Masahiro; Ehara, Shoichi; Yang, Eugene; Kosuge, Hisanori; Tsao, Philip S.; Quertermous, Thomas; Contag, Christopher H.; McConnell, Michael V.

2011-01-01

98

Development of bioluminescent Salmonella strains for use in food safety  

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Full Text Available Abstract Background Salmonella can reside in healthy animals without the manifestation of any adverse effects on the carrier. If raw products of animal origin are not handled properly during processing or cooked to a proper temperature during preparation, salmonellosis can occur. In this research, we developed bioluminescent Salmonella strains that can be used for real-time monitoring of the pathogen's growth on food products. To accomplish this, twelve Salmonella strains from the broiler production continuum were transformed with the broad host range plasmid pAKlux1, and a chicken skin attachment model was developed. Results Salmonella strains carrying pAKlux1 constitutively expressed the luxCDABE operon and were therefore detectable using bioluminescence. Strains were characterized in terms of bioluminescence properties and plasmid stability. To assess the usefulness of bioluminescent Salmonella strains in food safety studies, we developed an attachment model using chicken skin. The effect of washing on attachment of Salmonella strains to chicken skin was tested using bioluminescent strains, which revealed the attachment properties of each strain. Conclusion This study demonstrated that bioluminescence is a sensitive and effective tool to detect Salmonella on food products in real-time. Bioluminescence imaging is a promising technology that can be utilized to evaluate new food safety measures for reducing Salmonella contamination on food products.

Bailey R Hartford

2008-01-01

99

Time-resolved fluorescence spectroscopic study of flavin fluorescence in purified enzymes of bioluminescent bacteria  

Science.gov (United States)

Time-resolved fluorescence intensity and anisotropy decay measurements have been used to study the environment and rotational mobility of endogenous flavin in two purified enzymes of bioluminescent bacteria, Luciferase from Photobacterium leiognathi and NAD(P)H:FMN-oxidoreductase from Vibrio fischeri. We compared the time-resolved fluorescence parameters, intensity decay lifetimes, rotational correlation times, and their fractional contribution, of the endogeneous flavin fluorescence in each of the two enzymes in the presence or absence of quinones of different structures and redox potentials. The endogeneous flavin exhibited multi-exponential decay characteristics as compared to a single decay lifetime of around 5 ns for free flavin, suggesting a complex and heterogeneous environment of flavin bound to the enzyme. In addition, a significant increase in the rotational correlation time and a certain degree of ordering of the molecule were observed for endogenous flavin when compared to a single and fast rotational correlation time of 150 ps of free flavin. Quinone significantly altered both the lifetime and rotational characteristics of endogenous flavin suggesting specific interactions of quinones to the endogeneous flavin in the bacterial enzyme.

Vetrova, Elena; Kudryasheva, N.; Cheng, K.

2006-10-01

100

Noninvasive bioluminescence imaging of ?-synuclein oligomerization in mouse brain using split firefly luciferase reporters.  

Science.gov (United States)

Alpha-synuclein (?SYN) aggregation plays a pivotal role in the pathogenesis of Parkinson's disease and other synucleinopathies. In this multistep process, oligomerization of ?SYN monomers is the first step in the formation of fibrils and intracytoplasmic inclusions. Although ?SYN oligomers are generally considered to be the culprit of these diseases, the methodology currently available to follow-up oligomerization in cells and in brain is inadequate. We developed a split firefly luciferase complementation system to visualize oligomerization of viral vector-encoded ?SYN fusion proteins. ?SYN oligomerization resulted in successful luciferase complementation in cell culture and in mouse brain. Oligomerization of ?SYN was monitored noninvasively with bioluminescence imaging in the mouse striatum and substantia nigra up to 8 months after injection. Moreover, the visualized ?SYN oligomers retained their toxic and aggregation properties in both model systems. Next, the effect of two small molecules, FK506 and (-)-epigallocatechin-3-gallate (EGCG), known to inhibit ?SYN fibril formation, was investigated. FK506 inhibited the observed ?SYN oligomerization both in cell culture and in mouse brain. In conclusion, the split firefly luciferase-?SYN complementation assay will increase our insight in the role of ?SYN oligomers in synucleinopathies and opens new opportunities to evaluate potential ?SYN-based neuroprotective therapies. PMID:25471588

Aelvoet, Sarah-Ann; Ibrahimi, Abdelilah; Macchi, Francesca; Gijsbers, Rik; Van den Haute, Chris; Debyser, Zeger; Baekelandt, Veerle

2014-12-01

 
 
 
 
101

Evaluation of monkeypox virus infection of prairie dogs (Cynomys ludovicianus) using in vivo bioluminescent imaging  

Science.gov (United States)

Monkeypox (MPX) is a re-emerging zoonotic disease that is endemic in Central and West Africa, where it can cause a smallpox-like disease in humans. Despite many epidemiologic and field investigations of MPX, no definitive reservoir species has been identified. Using recombinant viruses expressing the firefly luciferase (luc) gene, we previously demonstrated the suitability of in vivo bioluminescent imaging (BLI) to study the pathogenesis of MPX in animal models. Here, we evaluated BLI as a novel approach for tracking MPX virus infection in black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs were affected during a multistate outbreak of MPX in the US in 2003 and have since been used as an animal model of this disease. Our BLI results were compared with PCR and virus isolation from tissues collected postmortem. Virus was easily detected and quantified in skin and superficial tissues by BLI before and during clinical phases, as well as in subclinical secondary cases, but was not reliably detected in deep tissues such as the lung. Although there are limitations to viral detection in larger wild rodent species, BLI can enhance the use of prairie dogs as an animal model of MPX and can be used for the study of infection, disease progression, and transmission in potential wild rodent reservoirs.

Falendysz, Elizabeth A.; Londoño-Navas, Angela M.; Meteyer, Carol U.; Pussini, Nicola; Lopera, Juan G.; Osorio, Jorge E.; Rocke, Tonie E.

2014-01-01

102

Rat model of metastatic breast cancer monitored by MRI at 3 tesla and bioluminescence imaging with histological correlation  

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Full Text Available Abstract Background Establishing a large rodent model of brain metastasis that can be monitored using clinically relevant magnetic resonance imaging (MRI techniques is challenging. Non-invasive imaging of brain metastasis in mice usually requires high field strength MR units and long imaging acquisition times. Using the brain seeking MDA-MB-231BR transfected with luciferase gene, a metastatic breast cancer brain tumor model was investigated in the nude rat. Serial MRI and bioluminescence imaging (BLI was performed and findings were correlated with histology. Results demonstrated the utility of multimodality imaging in identifying unexpected sights of metastasis and monitoring the progression of disease in the nude rat. Methods Brain seeking breast cancer cells MDA-MB-231BR transfected with firefly luciferase (231BRL were labeled with ferumoxides-protamine sulfate (FEPro and 1-3 × 106 cells were intracardiac (IC injected. MRI and BLI were performed up to 4 weeks to monitor the early breast cancer cell infiltration into the brain and formation of metastases. Rats were euthanized at different time points and the imaging findings were correlated with histological analysis to validate the presence of metastases in tissues. Results Early metastasis of the FEPro labeled 231BRL were demonstrated onT2*-weighted MRI and BLI within 1 week post IC injection of cells. Micro-metastatic tumors were detected in the brain on T2-weighted MRI as early as 2 weeks post-injection in greater than 85% of rats. Unexpected skeletal metastases from the 231BRL cells were demonstrated and validated by multimodal imaging. Brain metastases were clearly visible on T2 weighted MRI by 3-4 weeks post infusion of 231BRL cells, however BLI did not demonstrate photon flux activity originating from the brain in all animals due to scattering of the photons from tumors. Conclusion A model of metastatic breast cancer in the nude rat was successfully developed and evaluated using multimodal imaging including MRI and BLI providing the ability to study the temporal and spatial distribution of metastases in the brain and skeleton.

Klaunberg Brenda

2009-10-01

103

Following in real time the impact of pneumococcal virulence factors in an acute mouse pneumonia model using bioluminescent bacteria.  

Science.gov (United States)

Pneumonia is one of the major health care problems in developing and industrialized countries and is associated with considerable morbidity and mortality. Despite advances in knowledge of this illness, the availability of intensive care units (ICU), and the use of potent antimicrobial agents and effective vaccines, the mortality rates remain high(1). Streptococcus pneumoniae is the leading pathogen of community-acquired pneumonia (CAP) and one of the most common causes of bacteremia in humans. This pathogen is equipped with an armamentarium of surface-exposed adhesins and virulence factors contributing to pneumonia and invasive pneumococcal disease (IPD). The assessment of the in vivo role of bacterial fitness or virulence factors is of utmost importance to unravel S. pneumoniae pathogenicity mechanisms. Murine models of pneumonia, bacteremia, and meningitis are being used to determine the impact of pneumococcal factors at different stages of the infection. Here we describe a protocol to monitor in real-time pneumococcal dissemination in mice after intranasal or intraperitoneal infections with bioluminescent bacteria. The results show the multiplication and dissemination of pneumococci in the lower respiratory tract and blood, which can be visualized and evaluated using an imaging system and the accompanying analysis software. PMID:24637643

Saleh, Malek; Abdullah, Mohammed R; Schulz, Christian; Kohler, Thomas; Pribyl, Thomas; Jensch, Inga; Hammerschmidt, Sven

2014-01-01

104

Dynamic bioluminescence and fluorescence imaging of the effects of the antivascular agent Combretastatin-A4P (CA4P) on brain tumor xenografts.  

Science.gov (United States)

Combretastatin A-4 (CA4) is a natural product isolated from Combretum caffrum that inhibits tubulin polymerization by binding to the colchicine-binding site. A corresponding water soluble pro-drug (referred to as CA4P), has undergone extensive clinical trials and has been evaluated in pre-clinical studies using multiple modalities. We previously reported a novel assay based on dynamic bioluminescent imaging to assess tumor vascular disruption and now present its application to assessing multiple tumors simultaneously. The current study evaluated the vascular-disrupting activity of CA4P on subcutaneous 9L rat brain tumor xenografts in mice using dynamic bioluminescence imaging. A single dose of CA4P (120?mg/kg, intraperitoneally) induced rapid, temporary tumor vascular shutdown revealed by a rapid and reproducible decrease of light emission from luciferase-expressing 9L tumors following administration of luciferin as a substrate. A time-dependent reduction of tumor perfusion after CA4P treatment was confirmed by immunohistological assessment of the perfusion marker Hoechst 33342 and the tumor vasculature marker CD31. The vasculature showed distinct recovery within 24?h post therapy. Multiple tumors behaved similarly, although a size dependent vascular inhibition was observed. In conclusion, CA4P caused rapid, temporary tumor vascular shutdown and led to reduction of tumor perfusion in rat brain tumor xenografts and the multiple tumor approach should lead to more efficient studies requiring fewer animals and greater consistency. PMID:25305449

Liu, Li; Mason, Ralph P; Gimi, Barjor

2015-01-28

105

Physicochemical characterization and in vivo bioluminescence imaging of nanostructured lipid carriers for targeting the brain: apomorphine as a model drug  

International Nuclear Information System (INIS)

Nanostructured lipid carriers (NLCs) were prepared to investigate whether the duration of brain targeting and accumulation of drugs in the brain can be improved by intravenous delivery. NLCs were developed using cetyl palmitate as the lipid matrix, squalene as the cationic surfactant, and Pluronic F68, polysorbate 80 and polyethylene glycol as the interfacial additives. Solid lipid nanoparticles (SLNs) and lipid emulsions (LEs) were also prepared for comparison. An anti-Parkinson's drug, apomorphine, was used as the model drug. Nuclear magnetic resonance and differential scanning calorimetry showed possible interactions between the solid and liquid lipids in the inner core. The lipid nanoparticles with different compositions were characterized by mean size, zeta potential, apomorphine encapsulation and in vitro drug release. NLCs were 370-430 nm in size, which was between the sizes of the SLNs and LEs. A cationic surfactant was used to produce a positive surface charge of 42-50 mV. The base form of apomorphine was successfully entrapped by NLCs with an entrapment percentage of > 60%. The loading of apomorphine in nanoparticles resulted in a slower release behavior compared to the aqueous solution, with LEs showing the lowest release. In vivo real-time bioluminescence imaging of the rat brain revealed that NLCs could be targeted, through certain vessels, to selected brain regions. This effect was further confirmed by imaging the entire brain and brain slices. The resule entire brain and brain slices. The results indicated that NLCs with moderate additives are a promising controlled-release and drug-targeting system.

106

Novel mouse mammary cell lines for in vivo bioluminescence imaging (BLI of bone metastasis  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Tumor cell lines that can be tracked in vivo during tumorigenesis and metastasis provide vital tools for studying the specific cellular mechanisms that mediate these processes as well as investigating therapeutic targets to inhibit them. The goal of this study was to engineer imageable mouse mammary tumor cell lines with discrete propensities to metastasize to bone in vivo. Two novel luciferase expressing cell lines were developed and characterized for use in the study of breast cancer metastasis to bone in a syngeneic mouse model. Results The 4 T1.2 luc3 and 66c14 luc2 cell lines were shown to have high levels of bioluminescence intensity in vitro and in vivo after orthotopic injection into mouse mammary fat pads. The 4 T1.2 luc3 cell line was found to closely model the sites of metastases seen in human patients including lung, liver, and bone. Specifically, 4 T1.2 luc3 cells demonstrated a high incidence of metastasis to spine, with an ex-vivo BLI intensity three orders of magnitude above the commercially available 4 T1 luc2 cells. 66c14 luc2 cells also demonstrated metastasis to spine, which was lower than that of 4 T1.2 luc3 cells but higher than 4 T1 luc2 cells, in addition to previously unreported metastases in the liver. High osteolytic activity of the 4 T1.2 luc3 cells in vivo in the bone microenvironment was also detected. Conclusions The engineered 4 T1.2 luc3 and 66c14 luc2 cell lines described in this study are valuable tools for studying the cellular events moderating the metastasis of breast tumor cells to bone.

Bolin Celeste

2012-04-01

107

Establishment of cell strains stably-transfected with luciferase gene mediated by retrovirus and their detection with bioluminescence imaging system  

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Objective ?To establish cell strains stably transfected with Luciferase gene (Luc2), which was mediated by retrovirus, and explore the relationship between the number of Luc2-positive cells and light flux from bioluminescence imaging system by experiments in vitro and in vivo. Methods ?We co-transfected pMX-Luc2 plasmid and pMD.G plasmid into 293T gag-pol cells to get retrovirus expressing Luc2 gene. Stable Luc2 positive cell lines were generated and screened by transduction of Retro-Luc2...

Wang, Hai-juan; Meng, Xi-ting; Luan, Qing-chun; Liang, Xiao; Zhang, Xue-yan; Fu, Ming; Lin, Chen; Qian, Hai-li

2012-01-01

108

Establishment of cell strains stably-transfected with luciferase gene mediated by retrovirus and their detection with bioluminescence imaging system  

Directory of Open Access Journals (Sweden)

Full Text Available Objective ?To establish cell strains stably transfected with Luciferase gene (Luc2, which was mediated by retrovirus, and explore the relationship between the number of Luc2-positive cells and light flux from bioluminescence imaging system by experiments in vitro and in vivo. Methods ?We co-transfected pMX-Luc2 plasmid and pMD.G plasmid into 293T gag-pol cells to get retrovirus expressing Luc2 gene. Stable Luc2 positive cell lines were generated and screened by transduction of Retro-Luc2 in mouse colon cancer cell line CT26, human non-small cell lung cancer cell line NCI-H446, human colon cancer cell line HT-29, human ovarian carcinoma cell line SKOV3 and human hepatocellular carcinoma cell line SMMC-7721, all of them were identified by bioluminescence imaging system. Different numbers of SKOV3-Luc2 cells ranging from 10 to 10000 were plated onto culture dishes. Two xenograft models of ovarian cancer were reproduced by subcutaneous injection of 200?l SKOV3-Luc2 cell suspension with different concentrations (1×107, 5×106, 2.5×106, 1×106, 5×105, 2.5×105, 1×105 and 5×104/ml into 16 sites on the back of 4 nude mice, or intravenous injection of 1×106 or 3 ×106 SKOV3-Luc2 cells into the tail vein. Light flux value of SKOV3-Luc2 cells in dishes and in mice was measured by bioluminescence imaging system. Results ?Retro-Luc2 was constructed successfully and expressed Luc2 stably in transduced CT26, NCI-H446, HT-29, SKOV3 and SMMC-7721 cell lines. Light flux was correlated in a linear manner with the number of Luc2-positive cells in dishes and in mice (R2=0.944, ?=0.972; R2=0.991, ?=0.996; R2=0.351, ?=0.628; P < 0.01. Conclusion ?Luc2-positive cell lines could be established rapidly and accurately by infecting tumor cells with retrovirus expressing Luc2. The number of Luc2 positive cells is significantly related in a linear manner to light flux from bioluminescence imaging system in vitro and in vivo.

Hai-juan WANG

2012-05-01

109

In vivo quantitative assessment of cell viability of gadolinium or iron-labeled cells using MRI and bioluminescence imaging.  

Science.gov (United States)

In cell therapy, noninvasive monitoring of in vivo cell fate is challenging. In this study we investigated possible differences in R?, R? or R?* relaxation rate as a measure of overall cell viability for mesenchymal stem cells labeled with Gd-liposomes (Gd-MSCs) or iron oxide nanoparticles (SPIO-MSCs). Cells were also transduced with a luciferase vector, facilitating a correlation between MRI findings and cell viability using bioluminescence imaging (BLI). Viable Gd-MSCs were clearly distinguishable from nonviable Gd-MSCs under both in vitro and in vivo conditions, clearly differing quantitatively (?R? and ?R?) as well as by visual appearance (hypo- or hyperintense contrast). Immediately post-injection,viable Gd-MSCs caused a substantially larger ?R? and lower ?R? effect compared with nonviable MSCs. With time, the ?R? and ?R? relaxation rate showed a good negative correlation with increasing cell number following proliferation. Upon injection, no substantial quantitative or visual differences between viable and nonviable SPIO-MSCs were detected. Moreover, nonviable SPIO-MSCs caused a persisting signal void in vivo, compromising the specificity of this contrast agent. In vivo persistence of SPIO particles was confirmed by histological staining. A large difference was found between SPIO- and Gd-labeled cells in the accuracy of MR relaxometry in assessing the cell viability status. Gd-liposomes provide a more accurate and specific assessment of cell viability than SPIO particles. Viable Gd cells can be differentiated from nonviable Gd cells even by visual interpretation. These findings clearly indicate Gd to be the favourable contrast agent in qualitative and quantitative evaluation of labeled cell fate in future cell therapy experiments. PMID:23281289

Guenoun, Jamal; Ruggiero, Alessandro; Doeswijk, Gabriela; Janssens, Roel C; Koning, Gerben A; Kotek, Gyula; Krestin, Gabriel P; Bernsen, Monique R

2013-01-01

110

Effect of optical property estimation accuracy on tomographic bioluminescence imaging: simulation of a combined optical-PET (OPET) system  

International Nuclear Information System (INIS)

Inevitable discrepancies between the mouse tissue optical properties assumed by an experimenter and the actual physiological values may affect the tomographic localization of bioluminescent sources. In a previous work, the simplifying assumption of optically homogeneous tissues led to inaccurate localization of deep sources. Improved results may be obtained if a mouse anatomical map is provided by a high-resolution imaging modality and optical properties are assigned to segmented tissues. In this work, the feasibility of this approach was explored by simulating the effect of different magnitude optical property errors on the image formation process of a combined optical-PET system. Some comparisons were made with corresponding simulations using higher spatial resolution data that are typically attainable by CCD cameras. In addition, simulation results provided insights on some of the experimental conditions that could lead to poor localization of bioluminescent sources. They also provided a rough guide on how accurately tissue optical properties need to be known in order to achieve correct localization of point sources with increasing tissue depth under low background noise conditions

111

Bioluminescence imaging of leukemia cell lines in vitro and in mouse xenografts: effects of monoclonal and polyclonal cell populations on intensity and kinetics of photon emission  

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Abstract Background We investigated the utility of bioluminescence imaging (BLI) using firefly luciferase in monoclonal and polyclonal populations of leukemia cells in vitro and in vivo. Methods Monoclonal and polyclonal human lymphoid and myeloid leukemia cell lines transduced with firefly luciferase were used for BLI. Results Kinetics and dynamics of bioluminescence signal were cell line dependent. Luciferase expression decrease...

Christoph Sandra; Schlegel Jennifer; Alvarez-Calderon Francesca; Kim Yong-Mi; Brandao Luis N; DeRyckere Deborah; Graham Douglas K

2013-01-01

112

A Bone Metastasis Nude Mouse Model Created by Ultrasound Guided Intracardiac Injection of Breast Cancer Cells: the Micro-CT, MRI and Bioluminescence Imaging Analysis  

International Nuclear Information System (INIS)

The purpose of this study was to develop a nude mouse model of bone metastasis by performing intracardiac injection of breast cancer cells under ultrasonography guidance and we wanted to evaluate the development and the distribution of metastasis in vivo using micro-CT, MRI and bioluminescence imaging. Animal experiments were performed in 6-week-old female nude mice. The animals underwent left ventricular injection of 2x105 MDA-MB-231Bo-Luc cells. After injection of the tumor cells, serial bioluminescence imaging was performed for 7 weeks. The findings of micro-CT, MRI and the histology were correlated with the 'hot' lesions seen on the bioluminescence imaging. Metastasis was found in 62.3% of the animals. Two weeks after intracardiac injection, metastasis to the brain, spine and femur was detected with bioluminescence imaging with an increasing intensity by week 7. Micro-CT scan confirmed multiple osteolytic lesions at the femur, spine and skull. MRI and the histology were able to show metastasis in the brain and extraskeletal metastasis around the femur. The intracardiac injection of cancer cells under ultrasonography guidance is a safe and highly reproducible method to produce bone metastasis in nude mice. This bone metastasis nude mouse model will be useful to study the mechanism of bone metastasis and to validate new therapeutics

113

A Bone Metastasis Nude Mouse Model Created by Ultrasound Guided Intracardiac Injection of Breast Cancer Cells: the Micro-CT, MRI and Bioluminescence Imaging Analysis  

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The purpose of this study was to develop a nude mouse model of bone metastasis by performing intracardiac injection of breast cancer cells under ultrasonography guidance and we wanted to evaluate the development and the distribution of metastasis in vivo using micro-CT, MRI and bioluminescence imaging. Animal experiments were performed in 6-week-old female nude mice. The animals underwent left ventricular injection of 2x105 MDA-MB-231Bo-Luc cells. After injection of the tumor cells, serial bioluminescence imaging was performed for 7 weeks. The findings of micro-CT, MRI and the histology were correlated with the 'hot' lesions seen on the bioluminescence imaging. Metastasis was found in 62.3% of the animals. Two weeks after intracardiac injection, metastasis to the brain, spine and femur was detected with bioluminescence imaging with an increasing intensity by week 7. Micro-CT scan confirmed multiple osteolytic lesions at the femur, spine and skull. MRI and the histology were able to show metastasis in the brain and extraskeletal metastasis around the femur. The intracardiac injection of cancer cells under ultrasonography guidance is a safe and highly reproducible method to produce bone metastasis in nude mice. This bone metastasis nude mouse model will be useful to study the mechanism of bone metastasis and to validate new therapeutics

Park, Young Jin; Song, Eun Hye; Kim, Seol Hwa; Song, Ho Taek; Suh, Jin Suck [Yonsei University College of Medicine, Seoul (Korea, Republic of); Choi, Sang Hyun [Korean Minjok Leadership Academy, Heongsung (Korea, Republic of)

2011-01-15

114

Destabilized bioluminescent proteins  

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Purified nucleic acids, vectors and cells containing a gene cassette encoding at least one modified bioluminescent protein, wherein the modification includes the addition of a peptide sequence. The duration of bioluminescence emitted by the modified bioluminescent protein is shorter than the duration of bioluminescence emitted by an unmodified form of the bioluminescent protein.

Allen, Michael S. (Knoxville, TN); Rakesh, Gupta (New Delhi, IN); Gary, Sayler S. (Blaine, TN)

2007-07-31

115

Chemiluminescence and bioluminescence microbe detection  

Science.gov (United States)

Automated biosensors for online use with NASA Water Monitoring System employs bioluminescence and chemiluminescence techniques to rapidly measure microbe contamination of water samples. System eliminates standard laboratory procedures requiring time duration of 24 hours or longer.

Taylor, R. E.; Chappelle, E.; Picciolo, G. L.; Jeffers, E. L.; Thomas, R. R.

1978-01-01

116

Inflammatory modulating effects of low level laser therapy on iNOS expression by means of bioluminescence imaging  

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This study investigates the efficacy of low level laser therapy (LLLT) in modulating inducible nitric oxide synthase (iNOS) expression as molecular marker of the inflammation signaling pathway. LLLT was mediated by different therapeutic wavelengths using transgenic animals with the luciferase gene under control of the iNOS gene expression. Inflammation in 30 transgenic mice (iNOS-luc mice, from FVB strain) was induced by intra-articular injection of Zymosan-A in both knee joints. Four experimental groups were treated with one of four different wavelengths (?=635, 785, 808 and 905nm) and one not laser-irradiated control group. Laser treatment (25 mW cm-2, 5 J cm-2) was applied to the knees 15 minutes after inflammation induction. Measurements of iNOS expression were performed at multiple times (0, 3, 5, 7, 9 and 24h) post-LLLT by measuring the bioluminescence signal using a highly sensitive charge-coupled device (CCD) camera. The responsivity of BLI was sufficient to demonstrate a significant increase in bioluminescence signals after laser irradiation of 635nm when compared to non-irradiated animals and the other LLLT treated groups, showing the wavelength-dependence of LLLT on iNOS expression during the acute inflammatory process.

Moriyama, Yumi; Moriyama, Eduardo H.; Blackmore, Kristina; Akens, Margarete K.; Lilge, Lothar

2005-09-01

117

A novel triple-modality reporter gene for whole-body fluorescent, bioluminescent, and nuclear noninvasive imaging  

Energy Technology Data Exchange (ETDEWEB)

Two genetic reporter systems were developed for multimodality reporter gene imaging of different molecular-genetic processes using fluorescence, bioluminescence (BLI), and nuclear imaging techniques. The eGFP cDNA was fused at the N-terminus with HSV1-tk cDNA bearing a nuclear export signal from MAPKK (NES-HSV1-tk) or with truncation at the N-terminus of the first 45 amino acids ({delta}45HSV1-tk) and with firefly luciferase at the C-terminus. A single fusion protein with three functional subunits is formed following transcription and translation from a single open reading frame. The NES-TGL (NES-TGL) or {delta}45HSV1-tk/GFP/luciferase ({delta}45-TGL) triple-fusion gene cDNAs were cloned into a MoMLV-based retrovirus, which was used for transduction of U87 human glioma cells. The integrity, fluorescence, bioluminescence, and enzymatic activity of the TGL reporter proteins were assessed in vitro. The predicted molecular weight of the fusion proteins (130 kDa) was confirmed by western blot. The U87-NES-TGL and U87-{delta}45-TGL cells had cytoplasmic green fluorescence. The in vitro BLI was 7- and 13-fold higher in U87-NES-TGL and U87-{delta}45-TGL cells compared to nontransduced control cells. The Ki of {sup 14}C-FIAU was 0.49{+-}0.02, 0.51{+-}0.03, and 0.003{+-}0.001 ml/min/g in U87-NES-TGL, U87-{delta}45-TGL, and wild-type U87 cells, respectively. Multimodality in vivo imaging studies were performed in nu/nu mice bearing multiple s.c. xenografts established from U87-NES-TGL, U87-{delta}45-TGL, and wild-type U87 cells. BLI was performed after administration of d-luciferin (150 mg/kg i.v.). Gamma camera or PET imaging was conducted at 2 h after i.v. administration of [{sup 131}I]FIAU (7.4 MBq/animal) or [{sup 124}I]FIAU (7.4 MBq/animal), respectively. Whole-body fluorescence imaging was performed in parallel with the BLI and radiotracer imaging studies. In vivo BLI and gamma camera imaging showed specific localization of luminescence and radioactivity to the TGL transduced xenografts with background levels of activity in the wild-type xenografts. Tissue sampling yielded values of 0.47%{+-}0.08%, 0.86%{+-}0.06%, and 0.03%{+-}0.01%dose/g [{sup 131}I]FIAU in U87-NES-TGL, U87-{delta}45-TGL, and U87 xenografts, respectively. The TGL triple-fusion reporter gene preserves the functional activity of its subunits and is very effective for multimodality imaging. It provides for the seamless transition from fluorescence microscopy and FACS to whole-body bioluminescence imaging, to nuclear (PET, SPET, gamma camera) imaging, and back to in situ fluorescence image analysis. (orig.)

Ponomarev, Vladimir; Vider, Jelena; Shavrin, Aleksander; Ageyeva, Ludmila; Tourkova, Vilia [Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, NY 10021, New York (United States); Doubrovin, Michael; Serganova, Inna; Beresten, Tatiana; Ivanova, Anna; Blasberg, Ronald [Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York (United States); Balatoni, Julius [Radiochemistry/Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, New York (United States); Bornmann, William [Organic Chemistry Synthesis Core Facility, Memorial Sloan-Kettering Cancer Center, New York (United States); Gelovani Tjuvajev, Juri [Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, NY 10021, New York (United States); MD Anderson Cancer Center, 1515 Holcombe Road, Box 0057, TX 77030, Houston (United States)

2004-05-01

118

A novel triple-modality reporter gene for whole-body fluorescent, bioluminescent, and nuclear noninvasive imaging  

International Nuclear Information System (INIS)

Two genetic reporter systems were developed for multimodality reporter gene imaging of different molecular-genetic processes using fluorescence, bioluminescence (BLI), and nuclear imaging techniques. The eGFP cDNA was fused at the N-terminus with HSV1-tk cDNA bearing a nuclear export signal from MAPKK (NES-HSV1-tk) or with truncation at the N-terminus of the first 45 amino acids (?45HSV1-tk) and with firefly luciferase at the C-terminus. A single fusion protein with three functional subunits is formed following transcription and translation from a single open reading frame. The NES-TGL (NES-TGL) or ?45HSV1-tk/GFP/luciferase (?45-TGL) triple-fusion gene cDNAs were cloned into a MoMLV-based retrovirus, which was used for transduction of U87 human glioma cells. The integrity, fluorescence, bioluminescence, and enzymatic activity of the TGL reporter proteins were assessed in vitro. The predicted molecular weight of the fusion proteins (130 kDa) was confirmed by western blot. The U87-NES-TGL and U87-?45-TGL cells had cytoplasmic green fluorescence. The in vitro BLI was 7- and 13-fold higher in U87-NES-TGL and U87-?45-TGL cells compared to nontransduced control cells. The Ki of 14C-FIAU was 0.49±0.02, 0.51±0.03, and 0.003±0.001 ml/min/g in U87-NES-TGL, U87-?45-TGL, and wild-type U87 cells, respectively. Multimodality in vivo imaging studies were performed in nu/nu mice bearing multiple s.c. xenografts established from U87-NES-TGL, U87-?45-TGL, and wild--NES-TGL, U87-?45-TGL, and wild-type U87 cells. BLI was performed after administration of d-luciferin (150 mg/kg i.v.). Gamma camera or PET imaging was conducted at 2 h after i.v. administration of [131I]FIAU (7.4 MBq/animal) or [124I]FIAU (7.4 MBq/animal), respectively. Whole-body fluorescence imaging was performed in parallel with the BLI and radiotracer imaging studies. In vivo BLI and gamma camera imaging showed specific localization of luminescence and radioactivity to the TGL transduced xenografts with background levels of activity in the wild-type xenografts. Tissue sampling yielded values of 0.47%±0.08%, 0.86%±0.06%, and 0.03%±0.01%dose/g [131I]FIAU in U87-NES-TGL, U87-?45-TGL, and U87 xenografts, respectively. The TGL triple-fusion reporter gene preserves the functional activity of its subunits and is very effective for multimodality imaging. It provides for the seamless transition from fluorescence microscopy and FACS to whole-body bioluminescence imaging, to nuclear (PET, SPET, gamma camera) imaging, and back to in situ fluorescence image analysis. (orig.)

119

Candida albicans Biofilm Development on Medically-relevant Foreign Bodies in a Mouse Subcutaneous Model Followed by Bioluminescence Imaging.  

Science.gov (United States)

Candida albicans biofilm development on biotic and/or abiotic surfaces represents a specific threat for hospitalized patients. So far, C. albicans biofilms have been studied predominantly in vitro but there is a crucial need for better understanding of this dynamic process under in vivo conditions. We developed an in vivo subcutaneous rat model to study C. albicans biofilm formation. In our model, multiple (up to 9) Candida-infected devices are implanted to the back part of the animal. This gives us a major advantage over the central venous catheter model system as it allows us to study several independent biofilms in one animal. Recently, we adapted this model to study C. albicans biofilm development in BALB/c mice. In this model, mature C. albicans biofilms develop within 48 hr and demonstrate the typical three-dimensional biofilm architecture. The quantification of fungal biofilm is traditionally analyzed post mortem and requires host sacrifice. Because this requires the use of many animals to perform kinetic studies, we applied non-invasive bioluminescence imaging (BLI) to longitudinally follow up in vivo mature C. albicans biofilms developing in our subcutaneous model. C. albicans cells were engineered to express the Gaussia princeps luciferase gene (gLuc) attached to the cell wall. The bioluminescence signal is produced by the luciferase that converts the added substrate coelenterazine into light that can be measured. The BLI signal resembled cell counts obtained from explanted catheters. Non-invasive imaging for quantifying in vivo biofilm formation provides immediate applications for the screening and validation of antifungal drugs under in vivo conditions, as well as for studies based on host-pathogen interactions, hereby contributing to a better understanding of the pathogenesis of catheter-associated infections. PMID:25651138

Kucharíková, So?a; Vande Velde, Greetje; Himmelreich, Uwe; Van Dijck, Patrick

2015-01-01

120

Bioluminescence imaging as a marker for cellular Hsp70 response to thermal laser injury  

Science.gov (United States)

Assessment of laser tissue damage is not complete without an investigation into the cellular effects that are induced. In the past, tissue damage was quantified by such macroscopically visual results as tissue mass removal, carbonization, and melting. In this research, we used heat shock protein (hsp70) transcription, to track cellular response to laser injury. A stable cell line was generated containing the luciferase reporter gene attached to the heat shock protein (Hsp70) promoter. After thermal injury with a Holmium:YAG pulsed laser (wavelength= 2.1 ?m, pulsetime = 250 ?s, 30 pulses, 3 Hz), luciferase is produced upon hsp70 activation and emits bioluminescence at 563 nm. The luminescence was quantified with a liquid nitrogen cooled CCD camera. A minimum pulse energy (65 mJ/pulse, 2.0 mJ/mm2) was needed to activate the hsp70 response and a higher energy (103 mJ/pulse, 3.2 mJ/mm2) was associated with a reduction in hsp70 response. Bioluminescence levels correlated well to actual hsp70 protein concentrations as determined by ELISA assay. Photon counts were normalized to the percentage of live cells by means of a flow cytometry cell viability assay. The hsp70 response followed an Arrhenius relationship in nature when constant temperature water bath and constant area laser experiments were carried out.

Beckham, Joshua T.; Baran, Jennifer A.; Mackanos, Mark A.; Crooke, Cornelia; Takahashi, Takamune; O'Connell-Rodwell, Caitlin E.; Contag, Christopher H.; Jansen, E. Duco

2003-07-01

 
 
 
 
121

Synthetic strategies for controlling inter- and intramolecular interactions: Applications in single-molecule fluorescence imaging, bioluminescence imaging, and palladium catalysis  

Science.gov (United States)

The field of synthetic organic chemistry has reached such maturity that, with sufficient effort and resources, the synthesis of virtually any small molecule which exhibits reasonable stability at room temperature can be realized. While representing a monumental achievement for the field, the ability to exert precise control over molecular structure is just a means to an end, and it is frequently the responsibility of the synthetic chemist to determine which molecules should actually be synthesized. For better or worse, there exists no competitive free market in academia for new molecules, and as a result, the decision of which compounds should be synthesized is seldom driven by the forces of supply and demand; rather, it is guided by the synthetic chemist's interest in an anticipated structure-function relationship or in the properties of a previously unstudied class of molecules. As a consequence, there exists a pervasive need for chemists with synthetic expertise in fields (e.g., molecular imaging) and subdisciplines of chemistry (e.g., physical chemistry) in which the identification of promising synthetic targets dramatically outpaces the synthetic output in that field or subdiscipline, and ample opportunities are available for synthetic chemists who choose to pursue such cross-disciplinary research. This thesis describes synthetic efforts that leverage these opportunities to realize applications in biological imaging and in palladium catalysis. In Part I, the synthesis and characterization of three novel luminophores and their imaging applications are discussed. The first is a molecular beacon that utilizes a fluorophorefluorophore pair which exhibits H-dimer quenching in the closed conformation. This probe offers several advantages over conventional fluorophore-quencher molecular beacons in the detection of oligonucleotides, both in bulk and at the single-molecule level. Secondly, a fluorescent, Cy3-Cy5 covalent heterodimer is reported, which on account of the proximity of the Cy3 and Cy5 fluorophores, behaves as an optical photoswitch in the presence of a thiol reagent. This unique property was employed to achieve sub-diffraction-limited imaging of the stalks of Caulobacter crescentus cells with 30-nm resolution using STORM (stochastic optical reconstruction microscopy). Lastly, the synthesis of the first selenium analogue of firefly luciferin is described, and this analogue is shown to be a competent substrate for firefly luciferase (fLuc). Remarkably, it exhibits red-shifted bioluminescence emission relative to the native sulfur analogue. The in vivo performance of the selenium and sulfur analogues in imaging are compared by tail-vein injection into nude mice bearing subcutaneous tumor xenografts of a human breast cancer cell line that was stably transduced to express fLuc. Part II of this thesis begins by addressing design considerations in the development of palladium catalysts that effect oxidative transformations under mild conditions (i.e., 1 atm air, room temperature) using molecular oxygen as the terminal oxidant. A newly synthesized cationic palladium complex, [(2,9-dimethylphenanthroline)Pd(OAc)]2[OTf]2, is shown to catalyze aerobic alcohol oxidation under such conditions with an unprecedented initial turnover frequency, but the presence of partially reduced oxygen species results in competitive ligand oxidation with concomitant decrease in catalyst activity. To remedy this, oxidatively resistant ligands, which are essential for the development of next-generation, high-turnover-frequency palladium catalysts that utilize oxygen as a terminal oxidant, have been prepared and effectively employed. In addition, the first general palladium-catalyzed route to the carbonylation of diols is reported. In this system, carbon monoxide (1 atm) serves the carbonyl source, (2,9-dimethylphenanthroline)Pd(OAc) 2 acts as the catalyst, and N-chlorosuccinimide and iodosobenzene are the oxidants for 1,2- and 1,3-diols, respectively. This thesis illustrates the power of synthetic organic chemistry to exert precise control ove

Conley, Nicholas R.

122

Live imaging of bioluminescent leptospira interrogans in mice reveals renal colonization as a stealth escape from the blood defenses and antibiotics.  

Science.gov (United States)

Leptospira (L.) interrogans are bacteria responsible for a worldwide reemerging zoonosis. Some animals asymptomatically carry L. interrogans in their kidneys and excrete bacteria in their urine, which contaminates the environment. Humans are infected through skin contact with leptospires and develop mild to severe leptospirosis. Previous attempts to construct fluorescent or bioluminescent leptospires, which would permit in vivo visualization and investigation of host defense mechanisms during infection, have been unsuccessful. Using a firefly luciferase cassette and random transposition tools, we constructed bioluminescent chromosomal transformants in saprophytic and pathogenic leptospires. The kinetics of leptospiral dissemination in mice, after intraperitoneal inoculation with a pathogenic transformant, was tracked by bioluminescence using live imaging. For infective doses of 106 to 107 bacteria, we observed dissemination and exponential growth of leptospires in the blood, followed by apparent clearance of bacteria. However, with 2×108 bacteria, the septicemia led to the death of mice within 3 days post-infection. In surviving mice, one week after infection, pathogenic leptospires reemerged only in the kidneys, where they multiplied and reached a steady state, leading to a sustained chronic renal infection. These experiments reveal that a fraction of the leptospiral population escapes the potent blood defense, and colonizes a defined number of niches in the kidneys, proportional to the infective dose. Antibiotic treatments failed to eradicate leptospires that colonized the kidneys, although they were effective against L. interrogans if administered before or early after infection. To conclude, mice infected with bioluminescent L. interrogans proved to be a novel model to study both acute and chronic leptospirosis, and revealed that, in the kidneys, leptospires are protected from antibiotics. These bioluminescent leptospires represent a powerful new tool to challenge mice treated with drugs or vaccines, and test the survival, dissemination, and transmission of leptospires between environment and hosts. PMID:25474719

Ratet, Gwenn; Veyrier, Frédéric J; Fanton d'Andon, Martine; Kammerscheit, Xavier; Nicola, Marie-Anne; Picardeau, Mathieu; Boneca, Ivo G; Werts, Catherine

2014-12-01

123

Spectral Unmixing of Multicolored Bioluminescence Emitted from Heterogeneous Biological Sources  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A wide variety of bioluminescent luciferase proteins are available for use in transcriptional or biochemical reporter assays. However, spectral overlap normally prevents them from being monitored simultaneously. To address this problem, a Java plug-in for ImageJ was written to deconvolute bioluminescent images composed of signals from multiple luciferases. The methodology was validated by testing the program with both simulated and real luciferase images. Bioluminescent images were acquired u...

Gammon, Seth T.; Leevy, W. Matthew; Gross, Shimon; Gokel, George W.; Piwnica-worms, David

2006-01-01

124

Comparison of red-shifted firefly luciferase Ppy RE9 and conventional Luc2 as bioluminescence imaging reporter genes for in vivo imaging of stem cells  

Science.gov (United States)

One critical issue for noninvasive imaging of transplanted bioluminescent cells is the large amount of light absorption in tissue when emission wavelengths below 600 nm are used. Luciferase with a red-shifted spectrum can potentially bypass this limitation. We assessed and compared a mutant of firefly luciferase (Ppy RE9, PRE9) against the yellow luciferase luc2 gene for use in cell transplantation studies. C17.2 neural stem cells expressing PRE9-Venus and luc2-Venus were sorted by flow cytometry and assessed for bioluminescence in vitro in culture and in vivo after transplantation into the brain of immunodeficient Rag2-/- mice. We found that the luminescence from PRE9 was stable, with a peak emission at 620 nm, shifted to the red compared to that of luc2. The emission peak for PRE9 was pH-independent, in contrast to luc2, and much less affected by tissue absorbance compared to that of luc2. However, the total emitted light radiance from PRE9 was substantially lower than that of luc2, both in vitro and in vivo. We conclude that PRE9 has favorable properties as compared to luc2 in terms of pH independence, red-shifted spectrum, tissue light penetration, and signal quantification, justifying further optimization of protein expression and enzymatic activity.

Liang, Yajie; Walczak, Piotr; Bulte, Jeff W. M.

2012-01-01

125

Real-time, continuous detection of maltose using bioluminescence resonance energy transfer (BRET) on a microfluidic system.  

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We have previously shown that a genetically encoded bioluminescent resonance energy transfer (BRET) biosensor, comprising maltose binding protein (MBP) flanked by a green fluorescent protein (GFP(2)) at the N-terminus and a variant of Renilla luciferase (RLuc2) at the C-terminus, has superior sensitivity and limits of detection for maltose, compared with an equivalent fluorescent resonance energy transfer (FRET) biosensor. Here, we demonstrate that the same MBP biosensor can be combined with a microfluidic system for detection of maltose in water or beer. Using the BRET-based biosensor, maltose in water was detected on a microfluidic chip, either following a pre-incubation step or in real-time with similar sensitivity and dynamic range to those obtained using a commercial 96-well plate luminometer. The half-maximal effective concentrations (EC50) were 2.4×10(-7)M and 1.3×10(-7) M for maltose detected in pre-incubated and real-time reactions, respectively. To demonstrate real-time detection of maltose in a complex medium, we used it to estimate maltose concentration in a commercial beer sample in a real-time, continuous flow format. Our system demonstrates a promising approach to in-line monitoring for applications such as food and beverage processing. PMID:24999995

Le, Nam Cao Hoai; Gel, Murat; Zhu, Yonggang; Dacres, Helen; Anderson, Alisha; Trowell, Stephen C

2014-12-15

126

Evaluation of bioluminescent imaging for noninvasive monitoring of colorectal cancer progression in the liver and its response to immunogene therapy  

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Full Text Available Abstract Background Bioluminescent imaging (BLI is based on the detection of light emitted by living cells expressing a luciferase gene. Stable transfection of luciferase in cancer cells and their inoculation into permissive animals allows the noninvasive monitorization of tumor progression inside internal organs. We have applied this technology for the development of a murine model of colorectal cancer involving the liver, with the aim of improving the pre-clinical evaluation of new anticancer therapies. Results A murine colon cancer cell line stably transfected with the luciferase gene (MC38Luc1 retains tumorigenicity in immunocompetent C57BL/6 animals. Intrahepatic inoculation of MC38Luc1 causes progressive liver infiltration that can be monitored by BLI. Compared with ultrasonography (US, BLI is more sensitive, but accurate estimation of tumor mass is impaired in advanced stages. We applied BLI to evaluate the efficacy of an immunogene therapy approach based on the liver-specific expression of the proinflammatory cytokine interleukin-12 (IL-12. Individualized quantification of light emission was able to determine the extent and duration of antitumor responses and to predict long-term disease-free survival. Conclusion We show that BLI is a rapid, convenient and safe technique for the individual monitorization of tumor progression in the liver. Evaluation of experimental treatments with complex mechanisms of action such as immunotherapy is possible using this technology.

Gonzalez-Aparicio Manuela

2009-01-01

127

Evaluation of monkeypox virus infection of black-tailed prairie dogs (Cynomys ludovicianus) using in vivo bioluminescent imaging.  

Science.gov (United States)

Monkeypox (MPX) is a re-emerging zoonotic disease that is endemic in Central and West Africa, where it can cause a smallpox-like disease in humans. Despite many epidemiologic and field investigations of MPX, no definitive reservoir species has been identified. Using recombinant viruses expressing the firefly luciferase (luc) gene, we previously demonstrated the suitability of in vivo bioluminescent imaging (BLI) to study the pathogenesis of MPX in animal models. Here, we evaluated BLI as a novel approach for tracking MPX virus infection in black-tailed prairie dogs (Cynomys ludovicianus). Prairie dogs were affected during a multistate outbreak of MPX in the US in 2003 and have since been used as an animal model of this disease. Our BLI results were compared with PCR and virus isolation from tissues collected postmortem. Virus was easily detected and quantified in skin and superficial tissues by BLI before and during clinical phases, as well as in subclinical secondary cases, but was not reliably detected in deep tissues such as the lung. Although there are limitations to viral detection in larger wild rodent species, BLI can enhance the use of prairie dogs as an animal model of MPX and can be used for the study of infection, disease progression, and transmission in potential wild rodent reservoirs. PMID:24779460

Falendysz, Elizabeth A; Londoño-Navas, Angela M; Meteyer, Carol U; Pussini, Nicola; Lopera, Juan G; Osorio, Jorge E; Rocke, Tonie E

2014-07-01

128

Comparative live bioluminescence imaging of monkeypox virus dissemination in a wild-derived inbred mouse (Mus musculus castaneus) and outbred African dormouse (Graphiurus kelleni).  

Science.gov (United States)

Monkeypox virus belongs to the orthopoxvirus genus, infects rodents and monkeys in Africa, produces a smallpox-like zoonotic disease in humans, and has the potential for global spread and exploitation for bioterrorism. Several small animal models for studying monkeypox virus pathogenesis have been investigated. The African dormouse is a candidate natural host but is outbred and no immunological reagents exist. Although not a natural host, the CAST/EiJ mouse is inbred and animals and reagents are commercially available. We compared the dissemination of monkeypox virus by bioluminescence imaging in CAST/EiJ mice and dormice. In CAST/EiJ mice, intense replication occurred at the intranasal site of inoculation and virus spread rapidly to lungs and abdominal organs, which had a lower virus burden. Compared to CAST/EiJ mice, dormice exhibited a greater variation of virus spread, a slower time course, less replication in the head and chest, and more replication in abdominal organs prior to death. PMID:25462355

Earl, Patricia L; Americo, Jeffrey L; Cotter, Catherine A; Moss, Bernard

2015-01-15

129

Application of photosensitive devices to bioluminescence studies  

Energy Technology Data Exchange (ETDEWEB)

A brief review is given of some results obtained by the application of image intensification to studies of bioluminescence. The system consists of an image intensifier placed at the output of a suitable microscope, so that the image from the microscope falls on the intensifier cathode. The photon gain of the intensifier can be varied from a few thousand to one million. The output of the intensifier is recorded either on film or, in most applications to date, by means of a TV vidicon. The TV system permits display on a monitor in real time and simultaneous recording on magnetic tape for subsequent playback and analysis. It also provides time resolution for dynamic studies. Results are summarized for in vivo observations on Noctiluca miliaris, Obelia, Renilla, and Mnemiopsis leidyi. Utilization of the luminescence of aequorin in the presence of Ca/sup 2 +/ has been directed to observations on amoebae and the egg of the Medaka fish. Studies at the molecular level have been made by means of the spectral distribution of the output light. In these, the output of a fast input lens grating spectrometer is focused on the image intensifier cathode. Thus the entire visible spectrum of an in vivo bioluminescent flash can be intensified and recorded on film by photographing the output. The film is then analyzed by means of a digitized densitometer, and a computer program corrects the observed spectrum for system non-linearities and non-uniformities. In this way, the in vivo spectra of 15 bioluminescent species have been recorded.

Reynolds, G.T.

1978-01-01

130

Bioluminescent and micro-computed tomography imaging of bone repair induced by fibrin-binding growth factors.  

Science.gov (United States)

In this work we have evaluated the capacity of bone morphogenetic protein-2 (BMP-2) and fibrin-binding platelet-derived growth factor-BB (PDGF-BB) to support cell growth and induce bone regeneration using two different imaging technologies to improve the understanding of structural and organizational processes participating in tissue repair. Human mesenchymal stem cells from adipose tissue (hAMSCs) expressing two luciferase genes, one under the control of the cytomegalovirus (CMV) promoter and the other under the control of a tissue-specific promoter (osteocalcin or platelet endothelial cell adhesion molecule), were seeded in fibrin matrices containing BMP-2 and fibrin-binding PDGF-BB, and further implanted intramuscularly or in a mouse calvarial defect. Then, cell growth and bone regeneration were monitored by bioluminescence imaging (BLI) to analyze the evolution of target gene expression, indicative of cell differentiation towards the osteoblastic and endothelial lineages. Non-invasive imaging was supplemented with micro-computed tomography (?CT) to evaluate bone regeneration and high-resolution ?CT of vascular casts. Results from BLI showed hAMSC growth during the first week in all cases, followed by a rapid decrease in cell number; as well as an increment of osteocalcin but not PECAM-1 expression 3weeks after implantation. Results from ?CT show that the delivery of BMP-2 and PDGF-BB by fibrin induced the formation of more bone and improves vascularization, resulting in more abundant and thicker vessels, in comparison with controls. Although the inclusion of hAMSCs in the fibrin matrices made no significant difference in any of these parameters, there was a significant increment in the connectivity of the vascular network in defects treated with hAMSCs. PMID:24905933

Vila, Olaia F; Martino, Mikaël M; Nebuloni, Laura; Kuhn, Gisela; Pérez-Amodio, Soledad; Müller, Ralph; Hubbell, Jeffrey A; Rubio, Nuria; Blanco, Jerónimo

2014-10-01

131

Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Live animal imaging is becoming an increasingly common technique for accurate and quantitative assessment of tumor burden over time. Bioluminescence imaging systems rely on a bioluminescent signal from tumor cells, typically generated from expression of the firefly luciferase gene. However, previous reports have suggested that either a high level of luciferase or the resultant light reaction produced upon addition of D-luciferin substrate can have a negative influence on tu...

Ej, Rasko John; Ng Cynthia; Bailey Charles G; Tiffen Jessamy C; Holst Jeff

2010-01-01

132

Development of bioluminescent bioreporters for in vitro and in vivo tracking of Yersinia pestis.  

Science.gov (United States)

Yersinia pestis causes an acute infection known as the plague. Conventional techniques to enumerate Y. pestis can be labor intensive and do not lend themselves to high throughput assays. In contrast, bioluminescent bioreporters produce light that can be detected using plate readers or optical imaging platforms to monitor bacterial populations as a function of luminescence. Here, we describe the development of two Y. pestis chromosomal-based luxCDABE bioreporters, Lux(PtolC) and Lux(PcysZK). These bioreporters use constitutive promoters to drive expression of luxCDABE that allow for sensitive detection of bacteria via bioluminescence in vitro. Importantly, both bioreporters demonstrate a direct correlation between bacterial numbers and bioluminescence, which allows for bioluminescence to be used to compare bacterial numbers. We demonstrate the use of these bioreporters to test antimicrobial inhibitors (Lux(PtolC)) and monitor intracellular survival (Lux(PtolC) and Lux(PcysZK)) in vitro. Furthermore, we show that Y. pestis infection of the mouse model can be monitored using whole animal optical imaging in real time. Using optical imaging, we observed Y. pestis dissemination and differentiated between virulence phenotypes in live animals via bioluminescence. Finally, we demonstrate that whole animal optical imaging can identify unexpected colonization patterns in mutant-infected animals. PMID:23071730

Sun, Yanwen; Connor, Michael G; Pennington, Jarrod M; Lawrenz, Matthew B

2012-01-01

133

Bioluminescent Web Page  

Science.gov (United States)

This highly acclaimed website includes information on bioluminescence research, myths, photos, organisms, chemistry, physiology, distribution and more. Features an absolute must-see bioluminescence photo gallery. Also includes submitted abstracts and journal citations concerning bioluminescence, as well as proceedings from several related symposia. The chemistry section has molecular diagrams and several animated illustrations that explain the reaction behind fluorescence.

134

GMO detection using a bioluminescent real time reporter (BART of loop mediated isothermal amplification (LAMP suitable for field use  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background There is an increasing need for quantitative technologies suitable for molecular detection in a variety of settings for applications including food traceability and monitoring of genetically modified (GM crops and their products through the food processing chain. Conventional molecular diagnostics utilising real-time polymerase chain reaction (RT-PCR and fluorescence-based determination of amplification require temperature cycling and relatively complex optics. In contrast, isothermal amplification coupled to a bioluminescent output produced in real-time (BART occurs at a constant temperature and only requires a simple light detection and integration device. Results Loop mediated isothermal amplification (LAMP shows robustness to sample-derived inhibitors. Here we show the applicability of coupled LAMP and BART reactions (LAMP-BART for determination of genetically modified (GM maize target DNA at low levels of contamination (0.1-5.0% GM using certified reference material, and compare this to RT-PCR. Results show that conventional DNA extraction methods developed for PCR may not be optimal for LAMP-BART quantification. Additionally, we demonstrate that LAMP is more tolerant to plant sample-derived inhibitors, and show this can be exploited to develop rapid extraction techniques suitable for simple field-based qualitative tests for GM status determination. We also assess the effect of total DNA assay load on LAMP-BART quantitation. Conclusions LAMP-BART is an effective and sensitive technique for GM detection with significant potential for quantification even at low levels of contamination and in samples derived from crops such as maize with a large genome size. The resilience of LAMP-BART to acidic polysaccharides makes it well suited to rapid sample preparation techniques and hence to both high throughput laboratory settings and to portable GM detection applications. The impact of the plant sample matrix and genome loading within a reaction must be controlled to ensure quantification at low target concentrations.

Kiddle Guy

2012-04-01

135

Development of a novel liposomal nanodelivery system for bioluminescence imaging and targeted drug delivery in ErbB2-overexpressing metastatic ovarian carcinoma.  

Science.gov (United States)

Liposomes as targeted drug delivery systems are an emerging strategy in the treatment of cancer to selectively target tumors or genes. In this study, we generated the recombinant protein, EC1-GLuc, by fusing the EC1 peptide, an artificial ligand of ErbB2, with Gaussia luciferase (GLuc). The purified EC1-GLuc was conjugated with a nickel-chelating liposome to construct the EC1-GLuc-liposome. In vitro experiments revealed that the EC1-GLuc-liposome selectively targeted and internalized into ErbB2-overexpressing SKOv3 cells for bioluminescence imaging. A cell-impermeable fluorescence dye (HPTS) encapsulated in the EC-GLuc-liposome was efficiently delivered into the SKOv3 cells. In addition, the EC1-GLuc-liposome also targeted metastatic SKOv3 tumors for bioluminescence imaging and effectively delivered HPTS into metastatic tumors in vivo. Therefore, the present study demonstrates the novel EC1-GLuc-liposome to be an effective theranostic system for monitoring and treating ErbB2-overexpressing metastatic ovarian carcinoma through a combination of targeted molecular imaging and DDS. PMID:25190023

Han, Xiao-Jian; Wei, Yong-Fang; Wan, Yu-Ying; Jiang, Li-Ping; Zhang, Jian-Feng; Xin, Hong-Bo

2014-11-01

136

zebraflash transgenic lines for in vivo bioluminescence imaging of stem cells and regeneration in adult zebrafish  

Science.gov (United States)

The zebrafish has become a standard model system for stem cell and tissue regeneration research, based on powerful genetics, high tissue regenerative capacity and low maintenance costs. Yet, these studies can be challenged by current limitations of tissue visualization techniques in adult animals. Here we describe new imaging methodology and present several ubiquitous and tissue-specific luciferase-based transgenic lines, which we have termed zebraflash, that facilitate the assessment of regeneration and engraftment in freely moving adult zebrafish. We show that luciferase-based live imaging reliably estimates muscle quantity in an internal organ, the heart, and can longitudinally follow cardiac regeneration in individual animals after major injury. Furthermore, luciferase-based detection enables visualization and quantification of engraftment in live recipients of transplanted hematopoietic stem cell progeny, with advantages in sensitivity and gross spatial resolution over fluorescence detection. Our findings present a versatile resource for monitoring and dissecting vertebrate stem cell and regeneration biology. PMID:24198277

Chen, Chen-Hui; Durand, Ellen; Wang, Jinhu; Zon, Leonard I.; Poss, Kenneth D.

2013-01-01

137

Spectrally resolved bioluminescence tomography using the reciprocity approach  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Spectrally resolved bioluminescence optical tomography is an approach to recover images of, for example, Luciferase activity within a volume using multiwavelength emission data from internal bioluminescence sources. The underlying problem of uniqueness associated with nonspectrally resolved intensity-based bioluminescence tomography is demonstrated and it is shown that using a non-negative constraint inverse algorithm, an accurate solution for the source distribution can be calculated from th...

Dehghani, Hamid; Davis, Scott C.; Pogue, Brian W.

2008-01-01

138

Time encoded radiation imaging  

Energy Technology Data Exchange (ETDEWEB)

The various technologies presented herein relate to detecting nuclear material at a large stand-off distance. An imaging system is presented which can detect nuclear material by utilizing time encoded imaging relating to maximum and minimum radiation particle counts rates. The imaging system is integrated with a data acquisition system that can utilize variations in photon pulse shape to discriminate between neutron and gamma-ray interactions. Modulation in the detected neutron count rates as a function of the angular orientation of the detector due to attenuation of neighboring detectors is utilized to reconstruct the neutron source distribution over 360 degrees around the imaging system. Neutrons (e.g., fast neutrons) and/or gamma-rays are incident upon scintillation material in the imager, the photons generated by the scintillation material are converted to electrical energy from which the respective neutrons/gamma rays can be determined and, accordingly, a direction to, and the location of, a radiation source identified.

Marleau, Peter; Brubaker, Erik; Kiff, Scott

2014-10-21

139

Creatures of Darkness: Bioluminescence  

Science.gov (United States)

In this activity students investigate bioluminescence, which is light given off by living organisms and is common among creatures of the sea. Students discover that in the deep sea, where little or no sunlight penetrates, a variety of fishes live out their lives dependent upon bioluminescence, and that among these fishes, light organs have evolved to serve a number of purposes. Students will learn about the function of bioluminescence among some marine animals and conduct an experiment to test the function of bioluminescence as camouflage. Included is background information, materials, procedures, and a follow-up evaluation.

140

Effect of electromagnetic fields on the bacteria bioluminescent activity  

International Nuclear Information System (INIS)

The effect of electromagnetic field with frequency from 36.2 to 55.9 GHz on bioluminescence activity of bacterium were investigated. Electromagnetic field results in decrease of bioluminescence, which depends from frequency. The electromagnetic field adaptation time is higher of intrinsic time parameters of bioluminescence system. The effect has nonthermal nature. It is suggested that electromagnetic field influence connects with structure rearrangements near cell emitter. 8 refs.; 3 figs

 
 
 
 
141

Rat model of metastatic breast cancer monitored by MRI at 3 tesla and bioluminescence imaging with histological correlation  

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Abstract Background Establishing a large rodent model of brain metastasis that can be monitored using clinically relevant magnetic resonance imaging (MRI) techniques is challenging. Non-invasive imaging of brain metastasis in mice usually requires high field strength MR units and long imaging acquisition times. Using the brain seeking MDA-MB-231BR transfected with luciferase gene, a metastatic breast cancer brain tumor model was investigated in the nude rat. Serial MRI and bi...

Klaunberg Brenda; Ganjei Justin; Liu Wei; Lewis Bobbi K; Jordan Elaine K; Song Ho-Taek; Despres Daryl; Palmieri Diane; Frank Joseph A

2009-01-01

142

Formulation of photon diffusion from spherical bioluminescent sources in an infinite homogeneous medium  

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Full Text Available Abstract Background The bioluminescent enzyme firefly luciferase (Luc or variants of green fluorescent protein (GFP in transformed cells can be effectively used to reveal molecular and cellular features of neoplasia in vivo. Tumor cell growth and regression in response to various therapies can be evaluated by using bioluminescent imaging. In bioluminescent imaging, light propagates in highly scattering tissue, and the diffusion approximation is sufficiently accurate to predict the imaging signal around the biological tissue. The numerical solutions to the diffusion equation take large amounts of computational time, and the studies for its analytic solutions have attracted more attention in biomedical engineering applications. Methods Biological tissue is a turbid medium that both scatters and absorbs photons. An accurate model for the propagation of photons through tissue can be adopted from transport theory, and its diffusion approximation is applied to predict the imaging signal around the biological tissue. The solution to the diffusion equation is formulated by the convolution between its Green's function and source term. The formulation of photon diffusion from spherical bioluminescent sources in an infinite homogeneous medium can be obtained to accelerate the forward simulation of bioluminescent phenomena. Results The closed form solutions have been derived for the time-dependent diffusion equation and the steady-state diffusion equation with solid and hollow spherical sources in a homogeneous medium, respectively. Meanwhile, the relationship between solutions with a solid sphere source and ones with a surface sphere source is obtained. Conclusion We have formulated solutions for the diffusion equation with solid and hollow spherical sources in an infinite homogeneous medium. These solutions have been verified by Monte Carlo simulation for use in biomedical optical imaging studies. The closed form solution is highly accurate and more computationally efficient in biomedical engineering applications. By using our analytic solutions for spherical sources, we can better predict bioluminescent signals and better understand both the potential for, and the limitations of, bioluminescent tomography in an idealized case. The formulas are particularly valuable for furthering the development of bioluminescent tomography.

Wang Lihong V

2004-05-01

143

Time-domain imaging  

Science.gov (United States)

The quest for the highest resolution microwave imaging and principle of time-domain imaging has been the primary motivation for recent developments in time-domain techniques. With the present technology, fast time varying signals can now be measured and recorded both in magnitude and in-phase. It has also enhanced our ability to extract relevant details concerning the scattering object. In the past, the interface of object geometry or shape for scattered signals has received substantial attention in radar technology. Various scattering theories were proposed to develop analytical solutions to this problem. Furthermore, the random inversion, frequency swept holography, and the synthetic radar imaging, have two things in common: (1) the physical optic far-field approximation, and (2) the utilization of channels as an extra physical dimension, were also advanced. Despite the inherent vectorial nature of electromagnetic waves, these scalar treatments have brought forth some promising results in practice with notable examples in subsurface and structure sounding. The development of time-domain techniques are studied through the theoretical aspects as well as experimental verification. The use of time-domain imaging for space robotic vision applications has been suggested.

Tolliver, C. L.

1989-01-01

144

Luciferase expression and bioluminescence does not affect tumor cell growth in vitro or in vivo  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Live animal imaging is becoming an increasingly common technique for accurate and quantitative assessment of tumor burden over time. Bioluminescence imaging systems rely on a bioluminescent signal from tumor cells, typically generated from expression of the firefly luciferase gene. However, previous reports have suggested that either a high level of luciferase or the resultant light reaction produced upon addition of D-luciferin substrate can have a negative influence on tumor cell growth. To address this issue, we designed an expression vector that allows simultaneous fluorescence and luminescence imaging. Using fluorescence activated cell sorting (FACS, we generated clonal cell populations from a human breast cancer (MCF-7 and a mouse melanoma (B16-F10 cell line that stably expressed different levels of luciferase. We then compared the growth capabilities of these clones in vitro by MTT proliferation assay and in vivo by bioluminescence imaging of tumor growth in live mice. Surprisingly, we found that neither the amount of luciferase nor biophotonic activity was sufficient to inhibit tumor cell growth, in vitro or in vivo. These results suggest that luciferase toxicity is not a necessary consideration when designing bioluminescence experiments, and therefore our approach can be used to rapidly generate high levels of luciferase expression for sensitive imaging experiments.

Rasko John EJ

2010-11-01

145

In vivo bioluminescence tomography with a blocking-off finite-difference SP3 method and MRI?CT coregistration  

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Purpose: Bioluminescence imaging is a research tool for studying gene expression levels in small animal models of human disease. Bioluminescence light, however, is strongly scattered in biological tissue and no direct image of the light-emitting reporter probe’s location can be obtained. Therefore, the authors have developed a linear image reconstruction method for bioluminescence tomography (BLT) that recovers the three-dimensional spatial bioluminescent source distribution in small animals.

Klose, Alexander D.; Beattie, Bradley J.; Dehghani, Hamid; Vider, Lena; Le, Carl; Ponomarev, Vladimir; Blasberg, Ronald

2010-01-01

146

Bioluminescence in the high Arctic during the polar night  

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This study examines the composition and activity of the planktonic community during the polar night in the high Arctic Kongsfjord, Svalbard. Our results are the first published evidence of bioluminescence among zooplankton during the Arctic polar night. The observations were collected by a bathyphotometer detecting bioluminescence, integrated into an autonomous underwater vehicle, to determine the concentration and intensity of bioluminescent flashes as a function of time of day and depth. To...

Berge, Jørgen; Ba?tnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.

2012-01-01

147

Bioluminescence imaging of point sources implanted in small animals post mortem: evaluation of a method for estimating source strength and depth  

International Nuclear Information System (INIS)

The performance of a simple approach for the in vivo reconstruction of bioluminescent point sources in small animals was evaluated. The method uses the diffusion approximation as a forward model of light propagation from a point source in a homogeneous tissue to find the source depth and power. The optical properties of the tissue are estimated from reflectance images obtained at the same location on the animal. It was possible to localize point sources implanted in mice, 2-8 mm deep, to within 1 mm. The same performance was achieved for sources implanted in rat abdomens when the effects of tissue surface curvature were eliminated. The source power was reconstructed within a factor of 2 of the true power for the given range of depths, even though the apparent brightness of the source varied by several orders of magnitude. The study also showed that reconstructions using optical properties measured in situ were superior to those based on data in the literature

148

Stimulated bioluminescence by fluid shear stress associated with pipe flow  

Energy Technology Data Exchange (ETDEWEB)

Dinoflagellate can be stimulated bioluminescence by hydrodynamic agitation. Two typical dinoflagellate (Lingulodinium polyedrum and Pyrocystis noctiluca) was choosed to research stimulated bioluminescence. The bioluminescence intensity and shear stress intensity were measured using fully developed pipe flow. There is shear stress threshold to agitate organism bioluminescence. From these experiment, the response thresholds of the stimulated bioluminscence always occurred in laminar flows at a shear stress level of 0.6-3 dyn/cm{sup 2}. At the same time, the spectral characteristc of dinoflagellate was recorded, the wavelength of them is about 470nm, and the full width at half maximum is approximate 30nm.

Cao Jing; Wang Jiangan; Wu Ronghua, E-mail: caojing981@126.com [Col. of Electronic Eng., Naval University of Engineering, Wuhan 430033 (China)

2011-01-01

149

Stimulated bioluminescence by fluid shear stress associated with pipe flow  

International Nuclear Information System (INIS)

Dinoflagellate can be stimulated bioluminescence by hydrodynamic agitation. Two typical dinoflagellate (Lingulodinium polyedrum and Pyrocystis noctiluca) was choosed to research stimulated bioluminescence. The bioluminescence intensity and shear stress intensity were measured using fully developed pipe flow. There is shear stress threshold to agitate organism bioluminescence. From these experiment, the response thresholds of the stimulated bioluminscence always occurred in laminar flows at a shear stress level of 0.6-3 dyn/cm2. At the same time, the spectral characteristc of dinoflagellate was recorded, the wavelength of them is about 470nm, and the full width at half maximum is approximate 30nm.

150

Stimulated bioluminescence by fluid shear stress associated with pipe flow  

Science.gov (United States)

Dinoflagellate can be stimulated bioluminescence by hydrodynamic agitation. Two typical dinoflagellate (Lingulodinium polyedrum and Pyrocystis noctiluca) was choosed to research stimulated bioluminescence. The bioluminescence intensity and shear stress intensity were measured using fully developed pipe flow. There is shear stress threshold to agitate organism bioluminescence. From these experiment, the response thresholds of the stimulated bioluminscence always occurred in laminar flows at a shear stress level of 0.6-3 dyn/cm2. At the same time, the spectral characteristc of dinoflagellate was recorded, the wavelength of them is about 470nm, and the full width at half maximum is approximate 30nm.

Jing, Cao; Jiang-an, Wang; Ronghua, Wu

2011-01-01

151

Bioluminescence in Plankton and Nekton  

Science.gov (United States)

This article, written by Peter J. Herring and Edith Widder of the International Society for Bioluminescence and Chemilumenescence, features an excerpt about bioluminescence from the Encyclopedia of Ocean Science. It includes an introduction to bioluminescence and the biochemistry behind it, information about bioluminescent organisms including a table of typical genera and their type of luminescence, a discussion of measurement and applications of bioluminescence, and resources for further reading.

Herring, Peter J.; Widder, Edith

2009-06-17

152

Bioluminescence tomography by an iterative reweighted (l)2 norm optimization.  

Science.gov (United States)

Bioluminescence tomography is a promising tool in preclinical research, enabling noninvasive real-time in vivo imaging as well as quantitative analysis in small animal studies. Due to the difficulty of reconstruction, continuous efforts are still made to find more practical and efficient approaches. In this paper, we present an iterative reweighted l2-norm optimization incorporating anatomical structures in order to enhance the performance of bioluminescence tomography. The structure priors have been utilized to generate a heterogeneous mouse model by extracting the internal organs and tissues, which can assist in establishing a more precise photon diffusion model, as well as reflecting a more specific position of the reconstruction results inside the mouse. To evaluate the performance of the iterative reweighted approach, several numerical simulation studies including comparative analyses and multisource cases have been conducted to reconstruct the same datasets. The results suggest that the proposed method is able to ensure the accuracy, robustness, and efficiency of bioluminescence tomography. Finally, an in vivo experiment was performed to further validate its feasibility in a practical application. PMID:23974521

Ping Wu; Yifang Hu; Kun Wang; Jie Tian

2014-01-01

153

Action of ?-radiation on bioluminescence of Noctiluca miliaris  

International Nuclear Information System (INIS)

Results of the study in the action of various doses of irradiation on the bioluminescence of Noctiluca miliaris are presented. The doses are found that stimulate the bioluminescence and the dose - effect curves are obtained. It has been shown that stimulation of Noctiluca luminescence by ?-radiation is not of a constant character and extinguishes after a period of time determined by a dose rate

154

Quantitative bioluminescent imaging adapted to a murine syngeneic lymphoma expressing human CD20: analyses of tumor burden influence on response to treatment by a monoclonal antibody, rituximab, and therapeutic effect of neutrons on gadolinium oxide nanoparticles.  

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Tumor burden influence on individual response to treatment, with a monoclonal antibody: the rituximab, by quantitative bioluminescence imaging in a syngenic murine model of lymphoma expressing human CD20.In the last years, owing to advances carried out in the humanization of recombinant monoclonal antibodies (rmAb), these have seen an increase in their therapeutic use, especially in the treatment of cancer. Among these rmAb, rituximab (Mabthera®) was the first to get an approval ...

Dayde, David

2007-01-01

155

Thoughts on the diversity of convergent evolution of bioluminescence on earth  

Science.gov (United States)

The widespread independent evolution of analogous bioluminescent systems is one of the most impressive and diverse examples of convergent evolution on earth. There are roughly 30 extant bioluminescent systems that have evolved independently on Earth, with each system likely having unique enzymes responsible for catalysing the bioluminescent reaction. Bioluminescence is a chemical reaction involving a luciferin molecule and a luciferase or photoprotein that results in the emission of light. Some independent systems utilize the same luciferin, such as the use of tetrapyrrolic compounds by krill and dinoflagellates, and the wide use of coelenterazine by marine organisms, while the enzymes involved are unique. One common thread among all the different bioluminescent systems is the requirement of molecular oxygen. Bioluminescence is found in most forms of life, especially marine organisms. Bioluminescence in known to benefit the organism by: attraction, repulsion, communication, camouflage, and illumination. The marine ecosystem is significantly affected by bioluminescence, the only light found in the pelagic zone and below is from bioluminescent organisms. Transgenic bioluminescent organisms have revolutionized molecular research, medicine and the biotechnology industry. The use of bioluminescence in studying molecular pathways and disease allows for non-invasive and real-time analysis. Bioluminescence-based assays have been developed for several analytes by coupling luminescence to many enzyme-catalysed reactions.

Waldenmaier, Hans E.; Oliveira, Anderson G.; Stevani, Cassius V.

2012-10-01

156

la bioluminescence de l'aequorine en réponse au calcium In vitro et dans le Cortex cerebral  

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During my PhD, I investigated in vitro the calcium-dependent bioluminescence of thephotoprotein aequorin and then used its bioluminescence to image neuronal activities in theneocortical network. This genetically encoded calcium sensor can be expressed in specific cell types and its bioluminescence is not toxic and exhibit a high signal/noise ratio.I first search for mutations modifying aequorin bioluminescence, using a randommutagenesis and in vitro evolution approach. I isolated mutant...

Tricoire, Ludovic

2006-01-01

157

Bioluminescence in oceanology.  

Science.gov (United States)

For analytical purposes bioluminescence can be used in three main ways: 1. luminescence measurement of bioluminescent system components isolated in vitro; 2. determination of luminous organisms' reaction to the in vivo test-action; 3. measurement of bioluminescence in marine ecological systems. The majority of the reports of this Symposium are dealing with the first two topics. The aim of our presentation is to draw attention to the third one. The possibilities of bioluminescent analysis are wider than its traditional scheme of applications in the laboratory, when the emitting system is withdrawn from a native source and is placed in a cuvette of the light measuring device. The reverse scheme is also possible, i.e. the device can be introduced into light emitting system such as a marine biocenosis--the community of the sea inhabitants--where we obtain a highly sensitive and rapid means of gaining the information on the vital activity of marine ecosystems, i.e. their spatial structure, rhythms, man's influence upon them, etc. The present communication will consider the possibilities of this form of bioluminescent analysis. PMID:2801240

Gitelson, I I; Levin, L A

1989-07-01

158

Real time ultrasound image denoising  

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Image denoising is the process of removing the noise that perturbs image analysis methods. In some applications like segmentation or registration, denoising is intended to smooth homogeneous areas while preserving the contours. In many applications like video analysis, visual servoing or image-guided surgical interventions, real-time denoising is required. This paper presents a method for real-time denoising of ultrasound images: a modified version of the NL-means method is presented that inc...

Palhano Xavier Fontes, Fernanda; Andrade Barroso, Guillermo; Coupe?, Pierrick; Hellier, Pierre

2010-01-01

159

Attenuated Bioluminescent Brucella melitensis Mutants GR019 (virB4), GR024 (galE), and GR026 (BMEI1090-BMEI1091) Confer Protection in Mice  

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In vivo bioluminescence imaging is a persuasive approach to investigate a number of issues in microbial pathogenesis. Previously, we have applied bioluminescence imaging to gain greater insight into Brucella melitensis pathogenesis. Endowing Brucella with bioluminescence allowed direct visualization of bacterial dissemination, pattern of tissue localization, and the contribution of Brucella genes to virulence. In this report, we describe the pathogenicity of three attenuated bioluminescent B....

Rajashekara, Gireesh; Glover, David A.; Banai, Menachem; O Callaghan, David; Splitter, Gary A.

2006-01-01

160

Bioluminescence lights the way to food safety  

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The food industry is increasingly adopting food safety and quality management systems that are more proactive and preventive than those used in the past which have tended to rely on end product testing and visual inspection. The regulatory agencies in many countries are promoting one such management tool, Hazard Analysis Critical Control Point (HACCP), as a way to achieve a safer food supply and as a basis for harmonization of trading standards. Verification that the process is safe must involve microbiological testing but the results need not be generated in real-time. Of all the rapid microbiological tests currently available, the only ones that come close to offering real-time results are bioluminescence-based methods. Recent developments in application of bioluminescence for food safety issues are presented in the paper. These include the use of genetically engineered microorganisms with bioluminescent and fluorescent phenotypes as a real time indicator of physiological state and survival of food-borne pathogens in food and food processing environments as well as novel bioluminescent-based methods for rapid detection of pathogens in food and environmental samples. Advantages and pitfalls of the methods are discussed.

Brovko, Lubov Y.; Griffiths, Mansel W.

2003-07-01

 
 
 
 
161

Circadian regulation of bioluminescence in Gonyaulax involves translational control.  

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A 10-fold circadian variation in the amount of luciferin binding protein (LBP) in the marine dinoflagellate Gonyaulax polyedra is reported. This protein binds and stabilizes luciferin, the bioluminescence substrate. In early night phase, when bioluminescence is increasing and LBP levels are rising in the cell, pulse labeling experiments show that LBP is being rapidly synthesized in vivo. At other times, the rate of LBP synthesis is at least 50 times lower, while the rate of synthesis of most ...

Morse, D.; Milos, P. M.; Roux, E.; Hastings, J. W.

1989-01-01

162

Information-theoretic method for wavelength selection in bioluminescence tomography  

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Practical imaging constraints restrict the number of wavelengths that can be measured in a single Biolumines- cence Tomography imaging session, but it is unclear which set of measurement wavelengths is optimal, in the sense of providing the most information about the bioluminescent source. Mutual Information was used to integrate knowledge of the type of bioluminescent source likely to be present, the optical properties of tissue and physics of light propagation, and the noise characteristics of the imaging system, in order to quantify the information contained in measurements at different sets of wavelengths. The approach was applied to a two-dimensional sim- ulation of Bioluminescence Tomography imaging of a mouse, and the results indicate that different wavelengths and sets of wavelengths contain different amounts of information. When imaging at a single wavelength, 580nm was found to be optimal, and when imaging at two wavelengths, 570nm and 580nm were found to be optimal. Examination of the dispersion of the posterior distributions for single wavelengths suggests that information regarding the location of the centre of the bioluminescence distribution is relatively independent of wavelength, whilst information regarding the width of the bioluminescence distribution is relatively wavelength specific.

Basevi, Hector R. A.; Guggenheim, James A.; Dehghani, Hamid; Styles, Iain B.

2013-06-01

163

Bioluminescent bioreporter sensing of foodborne toxins  

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Histamine is the primary etiological agent in the foodborne disease scombrotoxicosis, one of the most common food toxicities related to fish consumption. Procedures for detecting histamine in fish products are available, but are often too expensive or too complex for routine use. As an alternative, a bacterial bioluminescent bioreporter has been constructed to develop a biosensor system that autonomously responds to low levels of histamine. The bioreporter contains a promoterless Photorhabdus luminescens lux operon (luxCDABE) fused with the Vibrio anguillarum angR regulatory gene promoter of the anguibactin biosynthetic operon. The bioreporter emitted 1.46 times more bioluminescence than background, 30 minutes after the addition of 100mM histamine. However, specificity was not optimal, as this biosensor generated significant bioluminescence in the presence of L-proline and L-histidine. As a means towards improving histamine specificity, the promoter region of a histamine oxidase gene from Arthrobacter globiformis was cloned upstream of the promotorless lux operon from Photorhabdus luminescens. This recently constructed whole-cell, lux-based bioluminescent bioreporter is currently being tested for optimal performance in the presence of histamine in order to provide a rapid, simple, and inexpensive model sensor for the detection of foodborne toxins.

Fraley, Amanda C.; Ripp, Steven; Sayler, Gary S.

2004-06-01

164

Construction of a bioluminescent mycobacterium and its use for assay of antimycobacterial agents.  

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To show, as a model system, that mycobacteria can express heterologous luciferase genes and that bioluminescence can be a rapid method of measuring antimycobacterial activity, a bioluminescent form of Mycobacterium smegmatis was made by transformation with a Mycobacterium-Escherichia coli shuttle vector containing the luxAB genes from Vibrio harveyi. The antimycobacterial effects of antibiotics and biocides could be assayed in real time by using bioluminescent M. smegmatis.

Andrew, P. W.; Roberts, I. S.

1993-01-01

165

Bioluminescent bacteria: lux genes as environmental biosensors  

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Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in env...

Nunes-Halldorson Vânia da Silva; Duran Norma Letícia

2003-01-01

166

Bioluminescent response of individual dinoflagellate cells to hydrodynamic stress measured with millisecond resolution in a microfluidic device.  

Science.gov (United States)

Dinoflagellate bioluminescence serves as a model system for examining mechanosensing by suspended motile unicellular organisms. The response latency, i.e. the delay time between the mechanical stimulus and luminescent response, provides information about the mechanotransduction and signaling process, and must be accurately known for dinoflagellate bioluminescence to be used as a flow visualization tool. This study used a novel microfluidic device to measure the response latency of a large number of individual dinoflagellates with a resolution of a few milliseconds. Suspended cells of several dinoflagellate species approximately 35 microm in diameter were directed through a 200 microm deep channel to a barrier with a 15 microm clearance impassable to the cells. Bioluminescence was stimulated when cells encountered the barrier and experienced an abrupt increase in hydrodynamic drag, and was imaged using high numerical aperture optics and a high-speed low-light video system. The average response latency for Lingulodinium polyedrum strain HJ was 15 ms (N>300 cells) at the three highest flow rates tested, with a minimum latency of 12 ms. Cells produced multiple flashes with an interval as short as 5 ms between individual flashes, suggesting that repeat stimulation involved a subset of the entire intracellular signaling pathway. The mean response latency for the dinoflagellates Pyrodinium bahamense, Alexandrium monilatum and older and newer isolates of L. polyedrum ranged from 15 to 22 ms, similar to the latencies previously determined for larger dinoflagellates with different morphologies, possibly reflecting optimization of dinoflagellate bioluminescence as a rapid anti-predation behavior. PMID:18723546

Latz, Michael I; Bovard, Michelle; VanDelinder, Virginia; Segre, Enrico; Rohr, Jim; Groisman, Alex

2008-09-01

167

GMO detection using a bioluminescent real time reporter (BART) of loop mediated isothermal amplification (LAMP) suitable for field use  

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Abstract Background There is an increasing need for quantitative technologies suitable for molecular detection in a variety of settings for applications including food traceability and monitoring of genetically modified (GM) crops and their products through the food processing chain. Conventional molecular diagnostics utilising real-time polymerase chain reaction (RT-PCR) and fluorescence-based determination of amplification require temperature cycling and relatively complex ...

Kiddle Guy; Hardinge Patrick; Buttigieg Neil; Gandelman Olga; Pereira Clint; McElgunn Cathal J; Rizzoli Manuela; Jackson Rebecca; Appleton Nigel; Moore Cathy; Tisi Laurence C; Ah, Murray James

2012-01-01

168

Bioluminescence Tomography: Biomedical Background, Mathematical Theory, and Numerical Approximation 1)  

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Over the last couple of years molecular imaging has been rapidly developed to study physiological and pathological processes in vivo at the cellular and molecular levels. Among molecular imaging modalities, optical imaging stands out for its unique advantages, especially performance and cost-effectiveness. Bioluminescence tomography (BLT) is an emerging optical imaging mode with promising biomedical advantages. In this survey paper, we explain the biomedical significance of BLT, summarize the...

Han, Weimin; Wang, Ge

2008-01-01

169

In vitro validation of bioluminescent monitoring of disease progression and therapeutic response in leukaemia model animals  

International Nuclear Information System (INIS)

The application of in vivo bioluminescence imaging to non-invasive, quantitative monitoring of tumour models relies on a positive correlation between the intensity of bioluminescence and the tumour burden. We conducted cell culture studies to investigate the relationship between bioluminescent signal intensity and viable cell numbers in murine leukaemia model cells. Interleukin-3 (IL-3)-dependent murine pro-B cell line Ba/F3 was transduced with firefly luciferase to generate cells expressing luciferase stably under the control of a retroviral long terminal repeat. The luciferase-expressing cells were transduced with p190 BCR-ABL to give factor-independent proliferation. The cells were cultured under various conditions, and bioluminescent signal intensity was compared with viable cell numbers and the cell cycle stage. The Ba/F3 cells showed autonomous growth as well as stable luciferase expression following transduction with both luciferase and p190 BCR-ABL, and in vivo bioluminescence imaging permitted external detection of these cells implanted into mice. The bioluminescence intensities tended to reflect cell proliferation and responses to imatinib in cell culture studies. However, the luminescence per viable cell was influenced by the IL-3 concentration in factor-dependent cells and by the stage of proliferation and imatinib concentration in factor-independent cells, thereby impairing the proportionality between viable cell number and bioluminescent signal intensitynumber and bioluminescent signal intensity. Luminescence per cell tended to vary in association with the fraction of proliferating cells. Although in vivo bioluminescence imaging would allow non-invasive monitoring of leukaemia model animals, environmental factors and therapeutic interventions may cause some discrepancies between tumour burden and bioluminescence intensity. (orig.)

170

The rapid bioluminescence assay method for content of bacteria in dehydrated vegetable and condiment before radiation  

International Nuclear Information System (INIS)

The microbial colony-forming unit (cfu) in dehydrated vegetable and condiment was determined by using ATP bioluminescence method. The result showed that bioluminescence of ATP was correlative to the microbial cfu obviously. The detecting time was within 1-2 h. This method could be applied to determine micro load of products before irradiation sterilization. (authors)

171

Real-time in vivo imaging of p16Ink4a reveals cross talk with p53  

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Expression of the p16Ink4a tumor suppressor gene, a sensor of oncogenic stress, is up-regulated by a variety of potentially oncogenic stimuli in cultured primary cells. However, because p16Ink4a expression is also induced by tissue culture stress, physiological mechanisms regulating p16Ink4a expression remain unclear. To eliminate any potential problems arising from tissue culture–imposed stress, we used bioluminescence imaging for noninvasive and real-time analysis of p16Ink4a expression u...

Yamakoshi, Kimi; Takahashi, Akiko; Hirota, Fumiko; Nakayama, Rika; Ishimaru, Naozumi; Kubo, Yoshiaki; Mann, David J.; Ohmura, Masako; Hirao, Atsushi; Saya, Hideyuki; Arase, Seiji; Hayashi, Yoshio; Nakao, Kazuki; Matsumoto, Mitsuru; Ohtani, Naoko

2009-01-01

172

Quantifying the activity of adenoviral E1A CR2 deletion mutants using renilla luciferase bioluminescence and 3'-deoxy-3'-[18F]fluorothymidine positron emission tomography imaging.  

Science.gov (United States)

The adenoviral E1A CR2 mutant dl922-947 has potent activity in ovarian cancer. We have used Renilla luciferase bioluminescence imaging to monitor viral E1A expression and replication and [18F]fluorothymidine positron emission tomography ([18F]FLT-PET) to quantify the activity of dl922-947 in vivo. We created dlCR2 Ren, with the same E1A CR2 deletion as dl922-947 and the luciferase gene from Renilla reniformis downstream of E1. Light emitted from s.c. and i.p. IGROV1 ovarian carcinoma xenografts was measured following treatment with dlCR2 Ren. Mice bearing s.c. IGROV1 xenografts were injected with 2.96 to 3.7 MBq of [18F]FLT 48 and 168 hours following i.t. injection of dl922-947 or control virus Ad LM-X. The presence of Renilla luciferase in dlCR2 Ren did not reduce in vitro nor in vivo potency compared with dl922-947. Light emission correlated closely with E1A expression in vitro and peaked 48 hours after dlCR2 Ren injection in both s.c. and i.p. IGROV1 xenografts. It diminished by 168 hours in s.c. tumors but persisted for at least 2 weeks in i.p. models. Normalized tumor [18F]FLT uptake at 60 minutes (NUV60), fractional retention, and area under radioactivity curve all decreased marginally 48 hours after dl922-947 treatment and significantly at 168 hours compared with controls. There was a close linear correlation between NUV60 and both tumor proliferation (Ki67 labeling index) and thymidine kinase 1 expression. Renilla luciferase bioluminescence and [18F]FLT-PET imaging are capable of quantifying the activity and effectiveness of E1A CR2-deleted adenoviral mutants in ovarian cancer. PMID:16982761

Leyton, Julius; Lockley, Michelle; Aerts, Joeri L; Baird, Sarah K; Aboagye, Eric O; Lemoine, Nicholas R; McNeish, Iain A

2006-09-15

173

Random matrix-based dimensionality reduction for bioluminescence tomography reconstruction  

Science.gov (United States)

We show how a random matrix can be used to reduce the dimensionality of the bioluminescence tomography reconstruction problem. A randomised low-rank approximation for the sensitivity matrix is computed, and we show how this can be used to reconstruct the bioluminescence source distribution on a randomised basis for the mesh nodes. The distribution on the original mesh can be found easily via a simple matrix multiplication. The majority of the computation required can be performed in advance of the reconstruction, and the reconstruction time itself is of the order milliseconds. This could allow for high frame rate real-time reconstructions to be performed.

Styles, Iain B.; Basevi, Hector R. A.; Guggenheim, James A.; Dehghani, Hamid

2013-06-01

174

Homogeneous, bioluminescent proteasome assays.  

Science.gov (United States)

Protein degradation is mediated predominantly through the ubiquitin-proteasome pathway. The importance of the proteasome in regulating degradation of proteins involved in cell-cycle control, apoptosis, and angiogenesis led to the recognition of the proteasome as a therapeutic target for cancer. The proteasome is also essential for degrading misfolded and aberrant proteins, and impaired proteasome function has been implicated in neurodegerative and cardiovascular diseases. Robust, sensitive assays are essential for monitoring proteasome activity and for developing inhibitors of the proteasome. Peptide-conjugated fluorophores are widely used as substrates for monitoring proteasome activity, but fluorogenic substrates can exhibit significant background and can be problematic for screening because of cellular autofluorescence or interference from fluorescent library compounds. Furthermore, fluorescent proteasome assays require column-purified 20S or 26S proteasome (typically obtained from erythrocytes), or proteasome extracts from whole cells, as their samples. To provide assays more amenable to high-throughput screening, we developed a homogeneous, bioluminescent method that combines peptide-conjugated aminoluciferin substrates and a stabilized luciferase. Using substrates for the chymotrypsin-like, trypsin-like, and caspase-like proteasome activities in combination with a selective membrane permeabilization step, we developed single-step, cell-based assays to measure each of the proteasome catalytic activities. The homogeneous method eliminates the need to prepare individual cell extracts as samples and has adequate sensitivity for 96- and 384-well plates. The simple "add and read" format enables sensitive and rapid proteasome assays ideal for inhibitor screening. PMID:25308265

O'Brien, Martha A; Moravec, Richard A; Riss, Terry L; Bulleit, Robert F

2015-01-01

175

Electron-multiplying charge-coupled detector-based bioluminescence recording of single-cell Ca2+.  

Science.gov (United States)

The construction and application of genetically encoded intracellular calcium concentration ([Ca2+]i) indicators has a checkered history. Excitement raised over the creation of new probes is often followed by disappointment when it is found that the initial demonstrations of [Ca2+]i sensing capability cannot be leveraged into real scientific advances. Recombinant apo-aequorin cloned from Aequorea victoria was the first Ca2+ sensitive protein genetically targeted to subcellular compartments. In the jellyfish, bioluminescence resonance energy transfer (BRET) between Ca2+ bound aequorin and green fluorescent protein (GFP) emits green light. Similarly, Ca2+ sensitive bioluminescent reporters undergoing BRET have been constructed between aequorin and GFP, and more recently with other fluorescent protein variants. These hybrid proteins display red-shifted spectrums and have higher light intensities and stability compared to aequorin alone. We report BRET measurement of single-cell [Ca2+]i based on the use of electron-multiplying charge-coupled-detector (EMCCD) imaging camera technology, mounted on either a bioluminescence or conventional microscope. Our results show for the first time how these new technologies make facile long-term monitoring of [Ca2+]i at the single-cell level, obviating the need for expensive, fragile, and sophisticated equipment based on image-photon-detectors (IPD) that were until now the only technical recourse to dynamic BRET experiments of this type. PMID:18601535

Rogers, Kelly L; Martin, Jean-Rene; Renaud, Olivier; Karplus, Eric; Nicola, Marie-Anne; Nguyen, Marie; Picaud, Sandrine; Shorte, Spencer L; Brûlet, Philippe

2008-01-01

176

Effect of irradiation on bioluminescence spectrum of microbial ATP  

International Nuclear Information System (INIS)

The effect of irradiation on bioluminescence spectrum of dehydrated cabbage microbial ATP was studied. The results showed that the spectral bandwidth of ATP standard was from 490 to 640 nm and the peak wavelength was at 563 nm. The spectral bandwidths of irradiated dehydrated cabbage microbial ATP and CK did not change. Peak wavelengths of dehydrated cabbage irradiated at different dosages were not significantly different from that of CK. The peaks of bioluminescence spectrum of irradiated samples were higher than that of CK, which may be because of the increasing concentration of ATP, and this effect would be kept for quite a long time after irradiation. (authors)

177

Time-correspondence differential ghost imaging  

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Experimental data with digital masks and a theoretical analysis are presented for an imaging scheme that we call time-correspondence differential ghost imaging (TCDGI). It is shown that by conditional averaging of the information from the reference detector but with the negative signals inverted, the quality of the reconstructed images is in general superior to all other ghost imaging (GI) methods to date. The advantages of both differential GI and time-correspondence GI are...

Li, Ming-fei; Zhang, Yu-ran; Luo, Kai-hong; Wu, Ling-an; Fan, Heng

2013-01-01

178

Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies  

Science.gov (United States)

Bacterial infection significantly impedes wound healing. Clinical diagnosis of wound infections is subjective and suboptimal, in part because bacteria are invisible to the naked eye during clinical examination. Moreover, bacterial infection can be present in asymptomatic patients, leading to missed opportunities for diagnosis and treatment. We developed a prototype handheld autofluorescence (AF) imaging device (Portable Real-time Optical Detection, Identification and Guidance for Intervention-PRODIGI) to noninvasively visualize and measure bacterial load in wounds in real time. We conducted preclinical pilot studies in an established nude mouse skin wound model inoculated with bioluminescent Staphylococcus aureus bacteria. We tested the feasibility of longitudinal AF imaging for in vivo visualization of bacterial load in skin wounds, validated by bioluminescence imaging. We showed that bacteria (S. aureus), occult to standard examination, can be visualized in wounds using PRODIGI. We also detected quantitative changes in wound bacterial load over time based on the antibiotic treatment and the correlation of bacterial AF intensity with bacterial load. AF imaging of wounds offers a safe, noninvasive method for visualizing the presence, location, and extent of bacteria as well as measuring relative changes in bacterial load in wounds in real time.

Wu, Yichao Charlie; Kulbatski, Iris; Medeiros, Philip J.; Maeda, Azusa; Bu, Jiachuan; Xu, Lizhen; Chen, Yonghong; DaCosta, Ralph S.

2014-08-01

179

Real-time image enhancement  

Science.gov (United States)

Pipelined system with "vision" algorithm is implemented on LSI chip that processes input digital image data to produce image-edge map. System contains 3 input adder, difference and absolute value cells, and adder and comparator. Data store for 1 to 2 ms, and are easily transmitted or isolated; design has reduced package count and number of interconnections for increased reliability. Applications include locating objects on moving belt, deep-sea and coal mining, and control of robotic rovers.

Wong, V. S.

1981-01-01

180

Automatic Segmentation Framework of Building Anatomical Mouse Model for Bioluminescence Tomography  

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Full Text Available Bioluminescence tomography is known as a highly ill-posed inverse problem. To improve the reconstruction performance by introducing anatomical structures as a priori knowledge, an automatic segmentation framework has been proposed in this paper to extract the mouse whole-body organs and tissues, which enables to build up a heterogeneous mouse model for reconstruction of bioluminescence tomography. Finally, an in vivo mouse experiment has been conducted to evaluate this framework by using an X-ray computed tomography system and a multi-view bioluminescence imaging system. The findings suggest that the proposed method can realize fast automatic segmentation of mouse anatomical structures, ultimately enhancing the reconstruction performance of bioluminescence tomography.

Abdullah Alali

2013-09-01

 
 
 
 
181

A gantry-based tri-modality system for bioluminescence tomography  

Science.gov (United States)

A gantry-based tri-modality system that combines bioluminescence (BLT), diffuse optical (DOT), and x-ray computed tomography (XCT) into the same setting is presented here. The purpose of this system is to perform bioluminescence tomography using a multi-modality imaging approach. As parts of this hybrid system, XCT and DOT provide anatomical information and background optical property maps. This structural and functional a priori information is used to guide and restrain bioluminescence reconstruction algorithm and ultimately improve the BLT results. The performance of the combined system is evaluated using multi-modality phantoms. In particular, a cylindrical heterogeneous multi-modality phantom that contains regions with higher optical absorption and x-ray attenuation is constructed. We showed that a 1.5 mm diameter bioluminescence inclusion can be localized accurately with the functional a priori information while its source strength can be recovered more accurately using both structural and the functional a priori information.

Yan, Han; Lin, Yuting; Barber, William C.; Unlu, Mehmet Burcin; Gulsen, Gultekin

2012-04-01

182

Bioluminescent signal system: bioluminescence immunoassay of pathogenic organisms.  

Science.gov (United States)

The Ca(2+)-regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. The hepatitis B virus (HbsAg) and the bacteria Escherichia coli and Shigella sonnei lipopolysaccharide (LPS) were chosen as model antigens. Chemically synthesized obelin-corresponding antibody conjugates were used in a solid-phase microplate immunoassay. The sensitivities achieved by the assay were 0.25 ng/mL for S. sonnei LPS and 0.375 ng/mL for HbsAg. A novel, filter-based immunoassay to determine bacterial admixtures in the environment was proposed. The NanoCeram filters were effectively applied to 'trap' and pre-concentrate pathogens from samples under study for the purposes of further detection and measurement of the absorbed material by bioluminescence immunoassay. PMID:17286244

Frank, L; Markova, S; Remmel, N; Vysotski, E; Gitelson, I

2007-01-01

183

A bioluminescent assay for monoamine oxidase activity.  

Science.gov (United States)

This article describes a novel two-step homogeneous bioluminescent assay for monoamine oxidase (MAO) that is simple, sensitive, and amenable to high-throughput screening. In the first step, MAO reacts with an aminopropylether analog of methyl ester luciferin. In the second step, a luciferin detection reagent inactivates MAO and converts the product of the first step into a luminescent signal. The amount of light produced is proportional to the amount of MAO and the time of incubation in the first step, but the luminescent signal is stable in the second step with a half-life greater than 5h. The assay has high precision, is more sensitive than current fluorescent methods, and can accurately measure the binding constants of known substrates and inhibitors. An automated screen of the Sigma-RBI Library of Pharmacologically Active Compounds (LOPAC(1280)) revealed a surprisingly high percentage of MAO inhibitors (16%) with a low false hit rate (0.9%). This implies that a significant number of compounds interact with the MAO enzymes and suggests that it is important to include MAO assays in drug metabolism studies. Other advantages of this bioluminescent assay over comparable fluorescent assays are discussed. PMID:17084801

Valley, Michael P; Zhou, Wenhui; Hawkins, Erika M; Shultz, John; Cali, James J; Worzella, Tracy; Bernad, Laurent; Good, Troy; Good, Dave; Riss, Terry L; Klaubert, Dieter H; Wood, Keith V

2006-12-15

184

Bacterial Bioluminescence: Its Control and Ecological Significance  

Science.gov (United States)

This Microbiological Reviews scholarly article (23-page PDF) presents an overview of data relevant to the ecology of bioluminescent bacteria and the functional importance of light emission. The review article discusses the biochemistry of bioluminescence, taxonomic relationships of luminous bacteria, control of the synthesis and activity of the luminescent system, habitats and distribution of luminous bacteria, functions of bioluminescence, and new perspectives. These perspectives and other specific postulates presented in the article provide new approaches for data collection and experimental work.

Hastings, J. Woodland (John Woodland), 1927-; Nealson, Kenneth H.

2010-03-24

185

A Nisin Bioassay Based on Bioluminescence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A Lactococcus lactis subsp. lactis strain that can sense the bacteriocin nisin and transduce the signal into bioluminescence was constructed. By using this strain, a bioassay based on bioluminescence was developed for quantification of nisin, for detection of nisin in milk, and for identification of nisin-producing strains. As little as 0.0125 ng of nisin per ml was detected within 3 h by this bioluminescence assay. This detection limit was lower than in previously described methods.

Wahlstro?m, G.; Saris, P. E. J.

1999-01-01

186

Mathematical Study and Numerical Simulation of Multispectral Bioluminescence Tomography  

Directory of Open Access Journals (Sweden)

Full Text Available Multispectral bioluminescence tomography (BLT attracts increasingly more attention in the area of optical molecular imaging. In this paper, we analyze the properties of the solutions to the regularized and discretized multispectral BLT problems. First, we show the solution existence, uniqueness, and its continuous dependence on the data. Then, we introduce stable numerical schemes and derive error estimates for numerical solutions. We report some numerical results to illustrate the performance of the numerical methods on the quality of multispectral BLT reconstruction.

Ge Wang

2006-12-01

187

Experimental Study on Bioluminescence Tomography with Multimodality Fusion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

To verify the influence of a priori information on the nonuniqueness problem of bioluminescence tomography (BLT), the multimodality imaging fusion based BLT experiment is performed by multiview noncontact detection mode, which incorporates the anatomical information obtained by the microCT scanner and the background optical properties based on diffuse reflectance measurements. In the reconstruction procedure, the utilization of adaptive finite element methods (FEMs) and a priori permissible s...

Yujie Lv; Jie Tian; Wenxiang Cong; Ge Wang

2007-01-01

188

Mathematical Study and Numerical Simulation of Multispectral Bioluminescence Tomography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Multispectral bioluminescence tomography (BLT) attracts increasingly more attention in the area of optical molecular imaging. In this paper, we analyze the properties of the solutions to the regularized and discretized multispectral BLT problems. First, we show the solution existence, uniqueness, and its continuous dependence on the data. Then, we introduce stable numerical schemes and derive error estimates for numerical solutions. We report some numerical results to illust...

Ge Wang; Wenxiang Cong; Weimin Han

2006-01-01

189

Preclinical evaluation of destruxin B as a novel Wnt signaling target suppressing proliferation and metastasis of colorectal cancer using non-invasive bioluminescence imaging  

Energy Technology Data Exchange (ETDEWEB)

In continuation to our studies toward the identification of direct anti-cancer targets, here we showed that destruxin B (DB) from Metarhizium anisopliae suppressed the proliferation and induced cell cycle arrest in human colorectal cancer (CRC) HT29, SW480 and HCT116 cells. Additionally, DB induced apoptosis in HT29 cells by decreased expression level of anti-apoptotic proteins Bcl-2 and Bcl-xL while increased pro-apoptotic Bax. On the other hand, DB attenuated Wnt-signaling by downregulation of ?-catenin, Tcf4 and ?-catenin/Tcf4 transcriptional activity, concomitantly with decreased expression of ?-catenin target genes cyclin D1, c-myc and survivin. Furthermore, DB affected the migratory and invasive ability of HT29 cells through suppressed MMPs-2 and -9 enzymatic activities. We also found that DB targeted the MAPK and/or PI3K/Akt pathway by reduced expression of Akt, IKK-?, JNK, NF-?B, c-Jun and c-Fos while increased that of I?B?. Finally, we demonstrated that DB inhibited tumorigenesis in HT29 xenograft mice using non-invasive bioluminescence technique. Consistently, tumor samples from DB-treated mice demonstrated suppressed expression of ?-catenin, cyclin D1, survivin, and endothelial marker CD31 while increased caspase-3 expression. Collectively, our data supports DB as an inhibitor of Wnt/?-catenin/Tcf signaling pathway that may be beneficial in the CRC management. Highlights: ? Destruxin B (DB) inhibited colorectal cancer cells growth and induced apoptosis. ? MAPK and/or PI3K/Akt cascade cooperates in DB induced apoptosis. ? DB affected the migratory and invasive ability of HT29 cells through MMP-9. ? DB attenuated Wnt-signaling components ?-catenin, Tcf4. ? DB attenuated cyclin D1, c-myc, survivin and tumorigenesis in HT29 xenograft mice.

Yeh, Chi-Tai [Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan (China); Center of Excellence for Cancer Research, Taipei Medical University, Taipei, Taiwan (China); Department of Surgery, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan (China); Rao, Yerra Koteswara [Institute of Biochemical Sciences and Technology, Chaoyang University of Technology, Taichung, Taiwan (China); Ye, Min [Department of Natural Medicine, School of Pharmaceutical Sciences, Peking University, Beijing (China); Wu, Wen-Shi [Department of Horticulture and Biotechnology, Chinese Culture University, Taipei, Taiwan (China); Chang, Tung-Chen [Department of Surgery, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan (China); Wang, Liang-Shun [Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan (China); Division of Thoracic Surgery, Department of Surgery, Shuang Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Wu, Chih-Hsiung [Center of Excellence for Cancer Research, Taipei Medical University, Taipei, Taiwan (China); Department of Surgery, Taipei Medical University-Shuang Ho Hospital, Taipei, Taiwan (China); Wu, Alexander T.H., E-mail: chaw1211@tmu.edu.tw [Ph.D. Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan (China); Department of Radiation Oncology, Taipei Medical University Hospital, Taipei, Taiwan (China); Tzeng, Yew-Min, E-mail: ymtzeng@cyut.edu.tw [Institute of Biochemical Sciences and Technology, Chaoyang University of Technology, Taichung, Taiwan (China)

2012-05-15

190

Preclinical evaluation of destruxin B as a novel Wnt signaling target suppressing proliferation and metastasis of colorectal cancer using non-invasive bioluminescence imaging  

International Nuclear Information System (INIS)

In continuation to our studies toward the identification of direct anti-cancer targets, here we showed that destruxin B (DB) from Metarhizium anisopliae suppressed the proliferation and induced cell cycle arrest in human colorectal cancer (CRC) HT29, SW480 and HCT116 cells. Additionally, DB induced apoptosis in HT29 cells by decreased expression level of anti-apoptotic proteins Bcl-2 and Bcl-xL while increased pro-apoptotic Bax. On the other hand, DB attenuated Wnt-signaling by downregulation of ?-catenin, Tcf4 and ?-catenin/Tcf4 transcriptional activity, concomitantly with decreased expression of ?-catenin target genes cyclin D1, c-myc and survivin. Furthermore, DB affected the migratory and invasive ability of HT29 cells through suppressed MMPs-2 and -9 enzymatic activities. We also found that DB targeted the MAPK and/or PI3K/Akt pathway by reduced expression of Akt, IKK-?, JNK, NF-?B, c-Jun and c-Fos while increased that of I?B?. Finally, we demonstrated that DB inhibited tumorigenesis in HT29 xenograft mice using non-invasive bioluminescence technique. Consistently, tumor samples from DB-treated mice demonstrated suppressed expression of ?-catenin, cyclin D1, survivin, and endothelial marker CD31 while increased caspase-3 expression. Collectively, our data supports DB as an inhibitor of Wnt/?-catenin/Tcf signaling pathway that may be beneficial in the CRC management. Highlights: ? Destruxin B (DB) inhibited colorectal cancer cells growth and induced apoptosis. ? MAPK and/or PI3K/Akt cascade cooperates in DB induced apoptosis. ? DB affected the migratory and invasive ability of HT29 cells through MMP-9. ? DB attenuated Wnt-signaling components ?-catenin, Tcf4. ? DB attenuated cyclin D1, c-myc, survivin and tumorigenesis in HT29 xenograft mice.

191

Spectrally resolved bioluminescence tomography with the third-order simplified spherical harmonics approximation  

Energy Technology Data Exchange (ETDEWEB)

Bioluminescence imaging has been extensively applied to in vivo small animal imaging. Quantitative three-dimensional bioluminescent source information obtained by using bioluminescence tomography can directly and much more accurately reflect biological changes as opposed to planar bioluminescence imaging. Preliminary simulated and experimental reconstruction results demonstrate the feasibility and promise of bioluminescence tomography. However, the use of multiple approximations, particularly the diffusion approximation theory, affects the quality of in vivo small animal-based image reconstructions. In the development of new reconstruction algorithms, high-order approximation models of the radiative transfer equation and spectrally resolved data introduce new challenges to the reconstruction algorithm and speed. In this paper, an SP{sub 3}-based (the third-order simplified spherical harmonics approximation) spectrally resolved reconstruction algorithm is proposed. The simple linear relationship between the unknown source distribution and the spectrally resolved data is established in this algorithm. A parallel version of this algorithm is realized, making BLT reconstruction feasible for the whole body of small animals especially for fine spatial domain discretization. In simulation validations, the proposed algorithm shows improved reconstruction quality compared with diffusion approximation-based methods when high absorption, superficial sources and detection modes are considered. In addition, comparisons between fine and coarse mesh-based BLT reconstructions show the effects of numerical errors in reconstruction image quality. Finally, BLT reconstructions using in vivo mouse experiments further demonstrate the potential and effectiveness of the SP{sub 3}-based reconstruction algorithm.

Lu Yujie; Douraghy, Ali; Stout, David; Herschman, Harvey; Chatziioannou, Arion F [Crump Institute for Molecular Imaging, Department of Molecular and Medical Pharmacology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Machado, Hidevaldo B [Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, CA 90095 (United States); Tian Jie [Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, PO Box 2728, Beijing 100190 (China)], E-mail: archatziioann@mednet.ucla.edu, E-mail: hherschman@mednet.ucla.edu

2009-11-07

192

Spectrally resolved bioluminescence tomography with the third-order simplified spherical harmonics approximation  

International Nuclear Information System (INIS)

Bioluminescence imaging has been extensively applied to in vivo small animal imaging. Quantitative three-dimensional bioluminescent source information obtained by using bioluminescence tomography can directly and much more accurately reflect biological changes as opposed to planar bioluminescence imaging. Preliminary simulated and experimental reconstruction results demonstrate the feasibility and promise of bioluminescence tomography. However, the use of multiple approximations, particularly the diffusion approximation theory, affects the quality of in vivo small animal-based image reconstructions. In the development of new reconstruction algorithms, high-order approximation models of the radiative transfer equation and spectrally resolved data introduce new challenges to the reconstruction algorithm and speed. In this paper, an SP3-based (the third-order simplified spherical harmonics approximation) spectrally resolved reconstruction algorithm is proposed. The simple linear relationship between the unknown source distribution and the spectrally resolved data is established in this algorithm. A parallel version of this algorithm is realized, making BLT reconstruction feasible for the whole body of small animals especially for fine spatial domain discretization. In simulation validations, the proposed algorithm shows improved reconstruction quality compared with diffusion approximation-based methods when high absorption, superficial sources and detection motion, superficial sources and detection modes are considered. In addition, comparisons between fine and coarse mesh-based BLT reconstructions show the effects of numerical errors in reconstruction image quality. Finally, BLT reconstructions using in vivo mouse experiments further demonstrate the potential and effectiveness of the SP3-based reconstruction algorithm.

193

Discovery of a Bioluminescent Octopus  

Science.gov (United States)

Bioluminescence (light produced by a chemical reaction that originates from the organism) is common in deep sea creatures such as squids and cuttlefish, but it is very rare among octopods. Light organs have only been seen in breeding octopod females of two genera. The exciting discovery of bioluminescence in a deep-sea finned octopod, Stauroteuthis syrtensis, is the focus of this week's In the News. The blue-green light is emitted from the octopods' suckers, which have characteristics of both photophores and suckers. Lack of fossil records of bioluminescence has made it difficult to study the evolutionary history of light production. However, since these modified suckers have retained structural characteristics of their previous function (adhesive suckers), this offers a rare opportunity to view the evolutionary history of light production. Senior Scientist, Edith Widder, at the Harbor Branch Oceanographic Institution (HBOI) explains it as an example of an evolutionary transition, in the March 11th issue of Nature (1999, 398:113-114). Widder believes that the "change from sucker to light organ may have occurred during colonization of the deep open-ocean by a creature that was originally a shallow-water bottom-dweller." Furthermore, it is hypothesized that these modified suckers may now function to attract prey and to visually communicate. The six sites listed provide information about this discovery along with background information on bioluminescense and octopods.

Nannapaneni, Sujani.

1999-01-01

194

Combining motility and bioluminescent signalling aids mate finding in deep-sea fish: a simulation study  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a model to estimate the mean time required for mate finding among deep-sea fish as a function of motility and the extent of bioluminescent signalling. This model differs from those of previous works in 3 important ways by including (1) sex differences in motility, (2) a maximum detection range of bioluminescent signals derived from a recently published mechanistic model based on physical principles and the physiology of vision, and (3) a novel consideration of the likelihood of ind...

Ruxton, G. D.; Bailey, D. M.

2005-01-01

195

Bacterial bioluminescence and Gumbel statistics: From quorum sensing to correlation  

Science.gov (United States)

We show that, in particular experimental conditions, the time course of the radiant fluxes, measured from a bioluminescent emission of a Vibrio harveyi related strain, collapse after suitable rescaling onto the Gumbel distribution of extreme value theory. We argue that the activation times of the strain luminous emission follow the universal behavior described by this statistical law, in spite of the fact that no extremal process is known to occur.

Delle Side, Domenico; Velardi, Luciano; Nassisi, Vincenzo; Pennetta, Cecilia; Alifano, Pietro; Talà, Adelfia; Salvatore Tredici, Maurizio

2013-12-01

196

Bioluminescence and 19F magnetic resonance imaging visualize the efficacy of lysostaphin alone and in combination with oxacillin against Staphylococcus aureus in murine thigh and catheter-associated infection models.  

Science.gov (United States)

Staphylococci are the leading cause of hospital-acquired infections worldwide. Increasingly, they resist antibiotic treatment owing to the development of multiple antibiotic resistance mechanisms in most strains. Therefore, the activity and efficacy of recombinant lysostaphin as a drug against this pathogen have been evaluated. Lysostaphin exerts high levels of activity against antibiotic-resistant strains of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA). The therapeutic value of lysostaphin has been analyzed in two different clinically relevant in vivo models, a catheter-associated infection model and a thigh infection model. We infected mice with luciferase-expressing S. aureus Xen 29, and the efficacies of lysostaphin, vancomycin, oxacillin, and combined lysostaphin-oxacillin were investigated by determining numbers of CFU, detecting bioluminescent signals, and measuring the accumulation of perfluorocarbon emulsion at the site of infection by (19)F magnetic resonance imaging. Lysostaphin treatment significantly reduced the bacterial burden in infected thigh muscles and, after systemic spreading from the catheter, in inner organs. The efficiency of lysostaphin treatment was even more pronounced in combinatorial therapy with oxacillin. These results suggest that recombinant lysostaphin may have potential as an anti-S. aureus drug worthy of further clinical development. In addition, both imaging technologies demonstrated efficacy patterns similar to that of CFU determination, although they proved to be less sensitive. Nonetheless, they served as powerful tools to provide additional information about the course and gravity of infection in a noninvasive manner, possibly allowing a reduction in the number of animals needed for research evaluation of new antibiotics in future studies. PMID:24366730

Hertlein, Tobias; Sturm, Volker; Lorenz, Udo; Sumathy, K; Jakob, Peter; Ohlsen, Knut

2014-01-01

197

REVIEW OF ENVIRONMENTAL APPLICATIONS OF BIOLUMINESCENCE MEASUREMENTS  

Science.gov (United States)

This review of the recent literature on environmental applications of bioluminescence systems will focus on in vivo and in vitro bioluminescence methods that have been utilized to elucidate properties of chemicals, toxic and mutagenic effects, and to estimate biomass. he unifying...

198

Time Variant Change Analysis in Satellite Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes the time variant changes in satellite images using Self Organizing Feature Map (SOFM) technique associated with Artificial Neural Network. In this paper, we take a satellite image and find the time variant changes using above technique with the help of MATLAB. This paper reviews remotely sensed data analysis with neural networks. First, we present an overview of the main concepts underlying Artificial Neural Networks (ANNs), including the main architectures and learning a...

Rachita Sharma; Sanjay Kumar Dubey

2013-01-01

199

Increased bioassay sensitivity of bioactive molecule discovery using metal-enhanced bioluminescence  

International Nuclear Information System (INIS)

We report the use of bioluminescence signal enhancement via proximity to deposited silver nanoparticles for bioactive compound discovery. This approach employs a whole-cell bioreporter harboring a plasmid-borne fusion of a specific promoter incorporated with a bioluminescence reporter gene. The silver deposition process was first optimized to provide optimal nanoparticle size in the reaction time dependence with fluorescein. The use of silver deposition of 350 nm particles enabled the doubling of the bioluminescent signal amplitude by the bacterial bioreporter when compared to an untouched non-silver-deposited microtiter plate surface. This recording is carried out in the less optimal but necessary far-field distance. SEM micrographs provided a visualization of the proximity of the bioreporter to the silver nanoparticles. The electromagnetic field distributions around the nanoparticles were simulated using Finite Difference Time Domain, further suggesting a re-excitation of non-chemically excited bioluminescence in addition to metal-enhanced bioluminescence. The possibility of an antiseptic silver effect caused by such a close proximity was eliminated disregarded by the dynamic growth curves of the bioreporter strains as seen using viability staining. As a highly attractive biotechnology tool, this silver deposition technique, coupled with whole-cell sensing, enables increased bioluminescence sensitivity, making it especially useful for cases in which reporter luminescence signals are very weak

200

Increased bioassay sensitivity of bioactive molecule discovery using metal-enhanced bioluminescence  

Energy Technology Data Exchange (ETDEWEB)

We report the use of bioluminescence signal enhancement via proximity to deposited silver nanoparticles for bioactive compound discovery. This approach employs a whole-cell bioreporter harboring a plasmid-borne fusion of a specific promoter incorporated with a bioluminescence reporter gene. The silver deposition process was first optimized to provide optimal nanoparticle size in the reaction time dependence with fluorescein. The use of silver deposition of 350 nm particles enabled the doubling of the bioluminescent signal amplitude by the bacterial bioreporter when compared to an untouched non-silver-deposited microtiter plate surface. This recording is carried out in the less optimal but necessary far-field distance. SEM micrographs provided a visualization of the proximity of the bioreporter to the silver nanoparticles. The electromagnetic field distributions around the nanoparticles were simulated using Finite Difference Time Domain, further suggesting a re-excitation of non-chemically excited bioluminescence in addition to metal-enhanced bioluminescence. The possibility of an antiseptic silver effect caused by such a close proximity was eliminated disregarded by the dynamic growth curves of the bioreporter strains as seen using viability staining. As a highly attractive biotechnology tool, this silver deposition technique, coupled with whole-cell sensing, enables increased bioluminescence sensitivity, making it especially useful for cases in which reporter luminescence signals are very weak.

Golberg, Karina, E-mail: karingo@bgu.ac.il; Elbaz, Amit [Ben-Gurion University of the Negev, Avram and Stella Goldstein-Goren Department of Biotechnology Engineering (Israel); McNeil, Ronald [The Institute of Fluorescence, University of Maryland Baltimore County (United States); Kushmaro, Ariel [Ben-Gurion University of the Negev, Avram and Stella Goldstein-Goren Department of Biotechnology Engineering (Israel); Geddes, Chris D. [The Institute of Fluorescence, University of Maryland Baltimore County (United States); Marks, Robert S., E-mail: rsmarks@bgu.ac.il [Ben-Gurion University of the Negev, Avram and Stella Goldstein-Goren Department of Biotechnology Engineering (Israel)

2014-12-15

 
 
 
 
201

Bioluminescence tomography based on the phase approximation model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A reconstruction method of bioluminescence sources is proposed based on a phase approximation model. Compared with the diffuse approximation, this phase approximation model more correctly predicts bioluminescence photon propagation in biological tissues, so that bioluminescence tomography can accurately locate and quantify the distribution of bioluminescence sources. The compressive sensing (CS) technique is applied to regularize the inverse source reconstruction to enhance numerical stabilit...

Cong, W.; Wang, G.

2010-01-01

202

COMPUTATION OF IMAGE SIMILARITY WITH TIME SERIES  

Directory of Open Access Journals (Sweden)

Full Text Available Searching for similar sequence in large database is an important task in temporal data mining. Similarity search is concerned with efficiently locating subsequences or whole sequences in large archives of sequences. It is useful in typical data mining applications and it can be easily extended to image retrieval. In this work, time series similarity analysis that involves dimensionality reduction and clustering is adapted on digital images to find similarity between them. The dimensionality reduced time series is represented as clusters by the use of K-Means clustering and the similarity distance between two images is found by finding the distance between the signatures of their clusters. To quantify the extent of similarity between two sequences, Earth Mover’s Distance (EMD is used. From the experiments on different sets of images, it is found that this technique is well suited for measuring the subjective similarity between two images.

V. Balamurugan

2011-11-01

203

Coherent interferometric imaging, time gating and beamforming  

International Nuclear Information System (INIS)

Coherent interferometric imaging is based on the backpropagation of local spacetime cross-correlations of array data and was introduced in order to improve images when the medium between the array and the object to be imaged is inhomogeneous and unknown (Borcea et al 2005 Inverse Problems 21 1419). Although this method has been shown to be effective and is well founded theoretically, the coherent interferometric imaging function is computationally expensive and therefore difficult to use. In this paper, we show that this function is equivalent to a windowed beamformer energy function, that is, a quadratic function that involves only time gating and time delaying signals in emission and in reception. In this form the coherent interferometric imaging can be implemented efficiently both in hardware and software, that is, at a computational cost that is comparable to the usual beamforming and migration imaging methods. We also revisit the trade-off between enhanced image stability and loss of resolution in coherent interferometry from the point of view of its equivalence to a windowed beamformer energy imaging function

204

Experimental Study on Bioluminescence Tomography with Multimodality Fusion  

Directory of Open Access Journals (Sweden)

Full Text Available To verify the influence of a priori information on the nonuniqueness problem of bioluminescence tomography (BLT, the multimodality imaging fusion based BLT experiment is performed by multiview noncontact detection mode, which incorporates the anatomical information obtained by the microCT scanner and the background optical properties based on diffuse reflectance measurements. In the reconstruction procedure, the utilization of adaptive finite element methods (FEMs and a priori permissible source region refines the reconstructed results and improves numerical robustness and efficiency. The comparison between the absence and employment of a priori information shows that multimodality imaging fusion is essential to quantitative BLT reconstruction.

Yujie Lv

2007-09-01

205

Can compression reduce forensic image time?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Creating a forensic copy (image) of a hard disk drive is one of the fundamental tasks a computer forensic analyst must perform. Time is often critical, and there is a need to consider a trade-off between a number of factors to achieve best results. This paper reports the results from an exploratory study into the impact of using disk drive compression on the time needed to image (and verify) a hard disk drive. It was found that time reduction may be achieved once the trade-off of contributing...

Jon Pearse; Brian Cusack

2011-01-01

206

Can compression reduce forensic image time?  

Directory of Open Access Journals (Sweden)

Full Text Available Creating a forensic copy (image of a hard disk drive is one of the fundamental tasks a computer forensic analyst must perform. Time is often critical, and there is a need to consider a trade-off between a number of factors to achieve best results. This paper reports the results from an exploratory study into the impact of using disk drive compression on the time needed to image (and verify a hard disk drive. It was found that time reduction may be achieved once the trade-off of contributing variables was properly estimated. The findings led the investigators to suggest a step-by-step decision making process for analysts when considering disk compression as a means for reducing total image processing time.

Jon Pearse

2011-07-01

207

Hydrodynamic stimulation of dinoflagellate bioluminescence: a computational and experimental study.  

Science.gov (United States)

Dinoflagellate bioluminescence provides a near-instantaneous reporter of cell response to flow. Although both fluid shear stress and acceleration are thought to be stimulatory, previous studies have used flow fields dominated by shear. In the present study, computational and experimental approaches were used to assess the relative contributions to bioluminescence stimulation of shear stress and acceleration in a laminar converging nozzle. This flow field is characterized by separate regions of pronounced acceleration away from the walls, and shear along the wall. Bioluminescence of the dinoflagellates Lingulodinium polyedrum and Ceratocorys horrida, chosen because of their previously characterized different flow sensitivities, was imaged with a low-light video system. Numerical simulations were used to calculate the position of stimulated cells and the levels of acceleration and shear stress at these positions. Cells were stimulated at the nozzle throat within the wall boundary layer where, for that downstream position, shear stress was relatively high and acceleration relatively low. Cells of C. horrida were always stimulated significantly higher in the flow field than cells of L. polyedrum and at lower flow rates, consistent with their greater flow sensitivity. For both species, shear stress levels at the position of stimulated cells were similar to but slightly greater than previously determined response thresholds using independent flow fields. L. polyedrum did not respond in conditions where acceleration was as high as 20 g. These results indicate that shear stress, rather than acceleration, was the stimulatory component of flow. Thus, even in conditions of high acceleration, dinoflagellate bioluminescence is an effective marker of shear stress. PMID:15107447

Latz, Michael I; Juhl, Andrew R; Ahmed, Abdel M; Elghobashi, Said E; Rohr, Jim

2004-05-01

208

Real-time image visualization for sensors  

Science.gov (United States)

Real-time image visualization simulation for sensors operating against synthetic environments comprised of natural backgrounds, cultural features, mobile objects, and dynamic weather is now a reality. A commercial software product is available which is capable of providing sensor image visualization for any spectral filter from the visible through the far infrared. The produce is called SensorVisionTM and is a module of a product called VegaTM. It is built upon IRIS PerformerTM and OpenGLTM software and is targeted for use on Silicon Graphics OnyxTM computers with InfiniteRealityTM or RealityEngine2TM graphics hardware. Vega with SensorVision is ideally suited to provide the scene image input to a real-time hardware-in-the-loop sensor simulation ranging from image intensified night vision goggles, to midwave FLIRs, to longwave FLIRs. SensorVision images are quantitative (each image pixel is expressed in watts/cm2/steradian), are computed in real-time, and represent the diurnal effects of weather (including surface temperature variation) on scene images. This paper presents the radiometric processes and algorithms used by the software when computing its output images and discusses the use of the software in hardware-in-the-loop simulation. The paper also highlights software capabilities and features, e.g.: Images include reflection from sun/moon and ambient sky illumination, and thermal emission from extended polygons with radiometric shading between vertices, and atmospheric attenuation and path radiance with pixel line- of-sight variability; Polygon surface temperatures of natural backgrounds and cultural features are computed asynchronously and continuously updated throughout diurnal cycle; Polygons are radiometrically textured and spatially correlated with visible RGB textures.

Anding, David C.; Szabo, Alexander

1996-05-01

209

Real Time Speckle Image De-Noising  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents real time speckle de-noising based on activity computation algorithm and wavelet transform. Speckles arise in an image when laser light is reflected from an illuminated surface. The process involves detection of speckles in an image by obtaining a number of frames of the same object under different illumination or angle and comparing the frames for the granular computation and de-noising the same on presence of greater activity index. The project can be im...

Kumar, D. Sachin; Seshadri, P. R.; Vaishnav, N.; Janaki, Dr Saraswathi

2014-01-01

210

COMPUTATION OF IMAGE SIMILARITY WITH TIME SERIES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Searching for similar sequence in large database is an important task in temporal data mining. Similarity search is concerned with efficiently locating subsequences or whole sequences in large archives of sequences. It is useful in typical data mining applications and it can be easily extended to image retrieval. In this work, time series similarity analysis that involves dimensionality reduction and clustering is adapted on digital images to find similarity between them. The dimensionality r...

Balamurugan, V.; Senthamarai Kannan, K.; Selvakumar, S.

2011-01-01

211

Three-dimensional multi bioluminescent sources reconstruction based on adaptive finite element method  

Science.gov (United States)

Among many optical molecular imaging modalities, bioluminescence imaging (BLI) has more and more wide application in tumor detection and evaluation of pharmacodynamics, toxicity, pharmacokinetics because of its noninvasive molecular and cellular level detection ability, high sensitivity and low cost in comparison with other imaging technologies. However, BLI can not present the accurate location and intensity of the inner bioluminescence sources such as in the bone, liver or lung etc. Bioluminescent tomography (BLT) shows its advantage in determining the bioluminescence source distribution inside a small animal or phantom. Considering the deficiency of two-dimensional imaging modality, we developed three-dimensional tomography to reconstruct the information of the bioluminescence source distribution in transgenic mOC-Luc mice bone with the boundary measured data. In this paper, to study the osteocalcin (OC) accumulation in transgenic mOC-Luc mice bone, a BLT reconstruction method based on multilevel adaptive finite element (FEM) algorithm was used for localizing and quantifying multi bioluminescence sources. Optical and anatomical information of the tissues are incorporated as a priori knowledge in this method, which can reduce the ill-posedness of BLT. The data was acquired by the dual modality BLT and Micro CT prototype system that was developed by us. Through temperature control and absolute intensity calibration, a relative accurate intensity can be calculated. The location of the OC accumulation was reconstructed, which was coherent with the principle of bone differentiation. This result also was testified by ex vivo experiment in the black 96-plate well using the BLI system and the chemiluminescence apparatus.

Ma, Xibo; Tian, Jie; Zhang, Bo; Zhang, Xing; Xue, Zhenwen; Dong, Di; Han, Dong

2011-03-01

212

Real-time imaging detectors for portal imaging  

International Nuclear Information System (INIS)

This paper reviews the status of real-time imaging systems which are used in radiation-therapy for radiotherapy localization and verification. Imaging systems under review include (1) metal-fluorescent screens, optically coupled to video cameras, (2) metal-phosphor screen in direct contact with two-dimensional photo-diode array (flat panel detector), (3) two-dimensional liquid ionization chamber and (5) linear diode arrays. These systems permit frequent verification during the treatment and have been shown to be very useful. Unfortunately the image quality achieved, while impressive considering the short time the devices have been on the market, is significantly inferior to that which is available form the metal/film combination (port film). The spatial resolution is about 1 lp/mm at 10% MTF, the Detective Quantum Efficiency (DQE) is less than 1% at 0 lp/mm and less than 0.1% at 1 lp/mm. It is also noted that these systems have not reached their ultimate limits of performance yet. The levels of x-ray fluence in the radiotherapy beam should allow a significant increase in the image quality. Nevertheless, the digital imaging systems available now are superior to analog film based systems because they provide a separation between the important functions of detection and display. They can provide almost instant image processing to optimize the information to be presented to the human observer. 100 refs., 11 figs., 4 tabs

213

QM/MM study on the light emitters of aequorin chemiluminescence, bioluminescence, and fluorescence: a general understanding of the bioluminescence of several marine organisms.  

Science.gov (United States)

Aequorea victoria is a type of jellyfish that is known by its famous protein, green fluorescent protein (GFP), which has been widely used as a probe in many fields. Aequorea has another important protein, aequorin, which is one of the members of the EF-hand calcium-binding protein family. Aequorin has been used for intracellular calcium measurements for three decades, but its bioluminescence mechanism remains largely unknown. One of the important reasons is the lack of clear and reliable knowledge about the light emitters, which are complex. Several neutral and anionic forms exist in chemiexcited, bioluminescent, and fluorescent states and are connected with the H-bond network of the binding cavity in the protein. We first theoretically investigated aequorin chemiluminescence, bioluminescence, and fluorescence in real proteins by performing hybrid quantum mechanics and molecular mechanics methods combined with a molecular dynamics method. For the first time, this study reported the origin and clear differences in the chemiluminescence, bioluminescence and fluorescence of aequorin, which is important for understanding the bioluminescence not only of jellyfish, but also of many other marine organisms (that have the same coelenterazine caved in different coelenterazine-type luciferases). PMID:23670851

Chen, Shu-Feng; Ferré, Nicolas; Liu, Ya-Jun

2013-06-24

214

A fast dynamic linked library based mixed-language programming technology for the trust region method in bioluminescence tomography  

Science.gov (United States)

Bioluminescence tomography (BLT) is a novel optical molecular imaging (MI) modality. It can reconstruct the inner bioluminescent light source distribution, according to the surface light distribution. The trust region method (TRM) can overcome the ill-posedness of BLT for its regularization property. As there exists a "TRUST" function that can solve the trust region subproblem in Matlab and Matlab's powerful matrix operation ability suited for TRM, the TRM is implemented in Matlab. Then the Matlab code of TRM is transformed into a dynamic linked library (DDL) and mixed together with the C++ code of the adaptive finite element (AFE) framework, using the mixed-language programming technology (MLPT). There are two main advantages of the MLPT. The first is taking advantages of all the participated programming languages. The second is time efficient. The usual way of transferring data between programmes written in different programming languages is to write the data first into files that are stored in the hard discs in one programme, and then read the files from another programme. Besides wasting time on writing and reading, it is difficult to keep the precision of the data. The DLL based MLPT can eliminate the need of installing code compilers in the platform running the software. Furthermore, in DLL, the code is implemented in C/C++ with high time efficiency, while the code in Matlab remains relatively low time efficiency. Finally, a numerical experiment is carried out to show MLPT's usage in the source reconstruction procedure of BLT, using the MLPT based on DLL.

Zhang, Bo; Tian, Jie; Yang, Xin; Qin, Chenghu; Han, Dong; Ma, Xibo

2011-03-01

215

Real-time optical image processing techniques  

Science.gov (United States)

Nonlinear real-time optical processing on spatial pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-channel spatial light modulators (MSLMs). Micro-channel spatial light modulators are modified via the Fabry-Perot method to achieve the high gamma operation required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness of the thresholding and also showed the needs of higher SBP for image processing. The Hughes LCLV has been characterized and found to yield high gamma (about 1.7) when operated in low frequency and low bias mode. Cascading of two LCLVs should also provide enough gamma for nonlinear processing. In this case, the SBP of the LCLV is sufficient but the uniformity of the LCLV needs improvement. These include image correlation, computer generation of holograms, pseudo-color image encoding for image enhancement, and associative-retrieval in neural processing. The discovery of the only known optical method for dynamic range compression of an input image in real-time by using GaAs photorefractive crystals is reported. Finally, a new architecture for non-linear multiple sensory, neural processing has been suggested.

Liu, Hua-Kuang

1988-01-01

216

Analytical Applications of Bioluminescence and Chemiluminescence  

Science.gov (United States)

Bioluminescence and chemiluminescence studies were used to measure the amount of adenosine triphosphate and therefore the amount of energy available. Firefly luciferase - luciferin enzyme system was emphasized. Photometer designs are also considered.

Chappelle, E. W. (editor); Picciolo, G. L. (editor)

1975-01-01

217

Small animal fluorescence and bioluminescence tomography: a review of approaches, algorithms and technology update  

Science.gov (United States)

Emerging fluorescence and bioluminescence tomography approaches have several common, yet several distinct features from established emission tomographies of PET and SPECT. Although both nuclear and optical imaging modalities involve counting of photons, nuclear imaging techniques collect the emitted high energy (100-511 keV) photons after radioactive decay of radionuclides while optical techniques count low-energy (1.5-4.1 eV) photons that are scattered and absorbed by tissues requiring models of light transport for quantitative image reconstruction. Fluorescence imaging has been recently translated into clinic demonstrating high sensitivity, modest tissue penetration depth, and fast, millisecond image acquisition times. As a consequence, the promise of quantitative optical tomography as a complement of small animal PET and SPECT remains high. In this review, we summarize the different instrumentation, methodological approaches and schema for inverse image reconstructions for optical tomography, including luminescence and fluorescence modalities, and comment on limitations and key technological advances needed for further discovery research and translation.

Darne, Chinmay; Lu, Yujie; Sevick-Muraca, Eva M.

2014-01-01

218

Catabolic gene expression is monitored by bioluminescence in bioreactor studies  

Energy Technology Data Exchange (ETDEWEB)

In order to study the expression of specific catabolic genes under defined conditions, and to determine whether certain conditions tend to increase or decrease metal catabolic activities, a bioreporter gene can be introduced into the microorganism. Activity from such bioreporter gene would indicate successful bioremediation. Our laboratory has produced several bioreporter strains using the bioluminescent lux genes of Vibrio fischeri. A bioreporter producing visible light when genetic expression is induced. The bioluminescent system include sensitivity of detection, analysis of response in real- time, and on-line capability. We constructed a bioreporter strain aimed at following the degradation of toluene and related compounds in order to study expression of the catabolic genes with various substrates and under optimized bioreactor conditions. We have been able to detect the induction of a specific operon in response to the addition of oxylene, as a gratuitous inducer of the catabolic genes. A strong bioluminescent signal in these studies. We have varied the medium of an induced bioreactor culture of RB1401, and our data suggest that conditions for optimal expression of the catabolic operon might not be identical with optimal growth conditions.

Burlage, R.S.; Kuo, D.; Palumbo, A.V.

1993-03-01

219

Catabolic gene expression is monitored by bioluminescence in bioreactor studies  

Energy Technology Data Exchange (ETDEWEB)

In order to study the expression of specific catabolic genes under defined conditions, and to determine whether certain conditions tend to increase or decrease metal catabolic activities, a bioreporter gene can be introduced into the microorganism. Activity from such bioreporter gene would indicate successful bioremediation. Our laboratory has produced several bioreporter strains using the bioluminescent lux genes of Vibrio fischeri. A bioreporter producing visible light when genetic expression is induced. The bioluminescent system include sensitivity of detection, analysis of response in real- time, and on-line capability. We constructed a bioreporter strain aimed at following the degradation of toluene and related compounds in order to study expression of the catabolic genes with various substrates and under optimized bioreactor conditions. We have been able to detect the induction of a specific operon in response to the addition of oxylene, as a gratuitous inducer of the catabolic genes. A strong bioluminescent signal in these studies. We have varied the medium of an induced bioreactor culture of RB1401, and our data suggest that conditions for optimal expression of the catabolic operon might not be identical with optimal growth conditions.

Burlage, R.S.; Kuo, D.; Palumbo, A.V.

1993-01-01

220

An adaptive regularization parameter choice strategy for multispectral bioluminescence tomography  

Energy Technology Data Exchange (ETDEWEB)

Purpose: Bioluminescence tomography (BLT) provides an effective tool for monitoring physiological and pathological activities in vivo. However, the measured data in bioluminescence imaging are corrupted by noise. Therefore, regularization methods are commonly used to find a regularized solution. Nevertheless, for the quality of the reconstructed bioluminescent source obtained by regularization methods, the choice of the regularization parameters is crucial. To date, the selection of regularization parameters remains challenging. With regards to the above problems, the authors proposed a BLT reconstruction algorithm with an adaptive parameter choice rule. Methods: The proposed reconstruction algorithm uses a diffusion equation for modeling the bioluminescent photon transport. The diffusion equation is solved with a finite element method. Computed tomography (CT) images provide anatomical information regarding the geometry of the small animal and its internal organs. To reduce the ill-posedness of BLT, spectral information and the optimal permissible source region are employed. Then, the relationship between the unknown source distribution and multiview and multispectral boundary measurements is established based on the finite element method and the optimal permissible source region. Since the measured data are noisy, the BLT reconstruction is formulated as l{sub 2} data fidelity and a general regularization term. When choosing the regularization parameters for BLT, an efficient model function approach is proposed, which does not require knowledge of the noise level. This approach only requests the computation of the residual and regularized solution norm. With this knowledge, we construct the model function to approximate the objective function, and the regularization parameter is updated iteratively. Results: First, the micro-CT based mouse phantom was used for simulation verification. Simulation experiments were used to illustrate why multispectral data were used rather than monochromatic data. Furthermore, the study conducted using an adaptive regularization parameter demonstrated our ability to accurately localize the bioluminescent source. With the adaptively estimated regularization parameter, the reconstructed center position of the source was (20.37, 31.05, 12.95) mm, and the distance to the real source was 0.63 mm. The results of the dual-source experiments further showed that our algorithm could localize the bioluminescent sources accurately. The authors then presented experimental evidence that the proposed algorithm exhibited its calculated efficiency over the heuristic method. The effectiveness of the new algorithm was also confirmed by comparing it with the L-curve method. Furthermore, various initial speculations regarding the regularization parameter were used to illustrate the convergence of our algorithm. Finally, in vivo mouse experiment further illustrates the effectiveness of the proposed algorithm. Conclusions: Utilizing numerical, physical phantom and in vivo examples, we demonstrated that the bioluminescent sources could be reconstructed accurately with automatic regularization parameters. The proposed algorithm exhibited superior performance than both the heuristic regularization parameter choice method and L-curve method based on the computational speed and localization error.

Feng Jinchao; Qin Chenghu; Jia Kebin; Han Dong; Liu Kai; Zhu Shouping; Yang Xin; Tian Jie [Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China); College of Electronic Information and Control Engineering, Beijing University of Technology, Beijing 100124 (China); Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China); Medical Image Processing Group, Institute of Automation, Chinese Academy of Sciences, P. O. Box 2728, Beijing 100190 (China) and School of Life Sciences and Technology, Xidian University, Xi' an 710071 (China)

2011-11-15

 
 
 
 
221

An adaptive regularization parameter choice strategy for multispectral bioluminescence tomography  

International Nuclear Information System (INIS)

Purpose: Bioluminescence tomography (BLT) provides an effective tool for monitoring physiological and pathological activities in vivo. However, the measured data in bioluminescence imaging are corrupted by noise. Therefore, regularization methods are commonly used to find a regularized solution. Nevertheless, for the quality of the reconstructed bioluminescent source obtained by regularization methods, the choice of the regularization parameters is crucial. To date, the selection of regularization parameters remains challenging. With regards to the above problems, the authors proposed a BLT reconstruction algorithm with an adaptive parameter choice rule. Methods: The proposed reconstruction algorithm uses a diffusion equation for modeling the bioluminescent photon transport. The diffusion equation is solved with a finite element method. Computed tomography (CT) images provide anatomical information regarding the geometry of the small animal and its internal organs. To reduce the ill-posedness of BLT, spectral information and the optimal permissible source region are employed. Then, the relationship between the unknown source distribution and multiview and multispectral boundary measurements is established based on the finite element method and the optimal permissible source region. Since the measured data are noisy, the BLT reconstruction is formulated as l2 data fidelity and a general regularization term. When choosing the regularization parameters for BLTsing the regularization parameters for BLT, an efficient model function approach is proposed, which does not require knowledge of the noise level. This approach only requests the computation of the residual and regularized solution norm. With this knowledge, we construct the model function to approximate the objective function, and the regularization parameter is updated iteratively. Results: First, the micro-CT based mouse phantom was used for simulation verification. Simulation experiments were used to illustrate why multispectral data were used rather than monochromatic data. Furthermore, the study conducted using an adaptive regularization parameter demonstrated our ability to accurately localize the bioluminescent source. With the adaptively estimated regularization parameter, the reconstructed center position of the source was (20.37, 31.05, 12.95) mm, and the distance to the real source was 0.63 mm. The results of the dual-source experiments further showed that our algorithm could localize the bioluminescent sources accurately. The authors then presented experimental evidence that the proposed algorithm exhibited its calculated efficiency over the heuristic method. The effectiveness of the new algorithm was also confirmed by comparing it with the L-curve method. Furthermore, various initial speculations regarding the regularization parameter were used to illustrate the convergence of our algorithm. Finally, in vivo mouse experiment further illustrates the effectiveness of the proposed algorithm. Conclusions: Utilizing numerical, physical phantom and in vivo examples, we demonstrated that the bioluminescent sources could be reconstructed accurately with automatic regularization parameters. The proposed algorithm exhibited superior performance than both the heuristic regularization parameter choice method and L-curve method based on the computational speed and localization error.

222

Protein-protein complexation in bioluminescence.  

Science.gov (United States)

In this review we summarize the progress made towards understanding the role of protein-protein interactions in the function of various bioluminescence systems of marine organisms, including bacteria, jellyfish and soft corals, with particular focus on methodology used to detect and characterize these interactions. In some bioluminescence systems, protein-protein interactions involve an "accessory protein" whereby a stored substrate is efficiently delivered to the bioluminescent enzyme luciferase. Other types of complexation mediate energy transfer to an "antenna protein" altering the color and quantum yield of a bioluminescence reaction. Spatial structures of the complexes reveal an important role of electrostatic forces in governing the corresponding weak interactions and define the nature of the interaction surfaces. The most reliable structural model is available for the protein-protein complex of the Ca(2+)-regulated photoprotein clytin and green-fluorescent protein (GFP) from the jellyfish Clytia gregaria, solved by means of Xray crystallography, NMR mapping and molecular docking. This provides an example of the potential strategies in studying the transient complexes involved in bioluminescence. It is emphasized that structural studies such as these can provide valuable insight into the detailed mechanism of bioluminescence. PMID:22231355

Titushin, Maxim S; Feng, Yingang; Lee, John; Vysotski, Eugene S; Liu, Zhi-Jie

2011-12-01

223

Temporal imaging using a time pinhole.  

Science.gov (United States)

We experimentally demonstrate a temporal imaging system based on a time pinhole. In accordance with the spatial pinhole-imaging counterpart, it consists of two sections of dispersion fibers connected by a temporal shutter, which is experimentally realized by a logic AND-gate with a short pulse. Both theoretical analysis and experimental results show that the output waveform is the scaled and broadened profile of the input waveform. Specifically, the output waveform is reversed if the signs of the dispersion on both sides of the time-gate are identical, otherwise it is non-reversed if the signs of the dispersion are opposite. Furthermore, we adjust the duration of the temporal shutter by changing the spectral width of the pulse, and investigate the effect of the shutter time on the performance of the output waveform. PMID:24718183

Wu, Zhao; Dong, Jianji; Hou, Jie; Yan, Siqi; Yu, Yu; Zhang, Xinliang

2014-04-01

224

Real-Time Imaging of Quantum Entanglement  

CERN Document Server

Quantum Entanglement - correlations between at least two systems that are stronger than classically explainable - is widely regarded as one of the most prominent features of quantum mechanics and quantum information science. Although, the creation of entanglement between two systems has become possible in laboratories, it has been out of the grasp of one of the most natural ways to investigate nature: direct visual observation. Here we show that modern imaging technology, namely a triggered intensified charge coupled device (ICCD) camera, is fast and sensitive enough to image in real-time the influence of the measurement of one photon on its entangled partner. To demonstrate the non-classicality of the measurements quantitatively from the registered intensity we develop a novel method to statistically analyze the image and precisely quantify the number of photons within a certain region. In addition, we show the high flexibility of our experimental setup in creating any desired spatial-mode entanglement, even...

Fickler, Robert; Lapkiewicz, Radek; Ramelow, Sven; Zeilinger, Anton

2013-01-01

225

Generation of a new bioluminescent model for visualisation of mammary tumour development in transgenic mice  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Numerous transgenic models have been generated to study breast cancer. However, despite many advantages, traditional transgenic models for breast cancer are also burdened with difficulties in early detection and longitudinal observation of transgene-induced tumours, which in most cases are randomly located and occur at various time points. Methods such as palpation followed by mechanical measurement of the tumours are of limited value in transgenic models. There is a crucial need for making these previously generated models suitable for modern methods of tumour visualisation and monitoring, e.g. by bioluminescence-based techniques. This approach was successfully used in the current study. Results A new mouse strain (MMTV-Luc2 mice expressing Luc2 luciferase primarily in mammary tissue in females, with low-level background expression in internal organs, was generated and bred to homozygosity. After these mice were intercrossed with MMTV-PyVT mice, all double transgenic females developed mammary tumours by the age of 10?weeks, the localisation and progression of which could be effectively monitored using the luminescence-based in vivo imaging. Luminescence-based readout allowed for early visualisation of the locally overgrown mammary tissue and for longitudinal evaluation of local progression of the tumours. When sampled ex vivo at the age of 10?weeks, all tumours derived from MMTV-Luc2PyVT females displayed robust bioluminescent signal. Conclusions We have created a novel transgenic strain for visualisation and longitudinal monitoring of mammary tumour development in transgenic mice as an addition and/or a new and more advanced alternative to manual methods. Generation of this mouse strain is vital for making many of the existing mammary tumour transgenic models applicable for in vivo imaging techniques.

Zagozdzon Agnieszka M

2012-05-01

226

Generation of a new bioluminescent model for visualisation of mammary tumour development in transgenic mice  

LENUS (Irish Health Repository)

AbstractBackgroundNumerous transgenic models have been generated to study breast cancer. However, despite many advantages, traditional transgenic models for breast cancer are also burdened with difficulties in early detection and longitudinal observation of transgene-induced tumours, which in most cases are randomly located and occur at various time points. Methods such as palpation followed by mechanical measurement of the tumours are of limited value in transgenic models. There is a crucial need for making these previously generated models suitable for modern methods of tumour visualisation and monitoring, e.g. by bioluminescence-based techniques. This approach was successfully used in the current study.ResultsA new mouse strain (MMTV-Luc2 mice) expressing Luc2 luciferase primarily in mammary tissue in females, with low-level background expression in internal organs, was generated and bred to homozygosity. After these mice were intercrossed with MMTV-PyVT mice, all double transgenic females developed mammary tumours by the age of 10?weeks, the localisation and progression of which could be effectively monitored using the luminescence-based in vivo imaging. Luminescence-based readout allowed for early visualisation of the locally overgrown mammary tissue and for longitudinal evaluation of local progression of the tumours. When sampled ex vivo at the age of 10?weeks, all tumours derived from MMTV-Luc2PyVT females displayed robust bioluminescent signal.ConclusionsWe have created a novel transgenic strain for visualisation and longitudinal monitoring of mammary tumour development in transgenic mice as an addition and\\/or a new and more advanced alternative to manual methods. Generation of this mouse strain is vital for making many of the existing mammary tumour transgenic models applicable for in vivo imaging techniques.

Zagozdzon, Agnieszka M

2012-05-30

227

Scan time reduction in spectroscopic imaging  

International Nuclear Information System (INIS)

Reducing the rather long acquisition times of proton MR spectroscopic imaging (MRSI) is one of the steps towards making this non-invasive tool for mapping metabolite concentrations clinically useful. One approach is sensitivity encoding (SENSE), which makes use of a receiver coil array to reduce the number of data acquisition steps. This work shows that, using this method, scan time can be reduced by a factor of four in conventional MRSI (CSI) as well as in the already fast 'Turbo Spectroscopic Imaging' (TSI) technique. In this fashion a 32x32 MRSI measurement can be accomplished in only 3 minutes. Results of in vivo SENSE-CSI and SENSE-TSI measurements are presented and compared with conventional MRSI. (author)

228

Time-lapse imaging of nuclear bodies.  

Science.gov (United States)

Fluorescence microscopy is a powerful technique that has become central in the study of the structure and function of biological specimens. This is due in large part to its specificity and versatility. Although an understanding of structure-typically through high-resolution imaging of fixed material-has proved an important tool to understanding function, fluorescence microscopy also offers a mechanism to interrogate cells in the living state, providing a means to explore dynamic process within the specimen over long time periods at high temporal resolution. The cell nucleus is a highly compartmented environment whose components are often highly motile and in a constant state of flux. The ability to monitor the dynamic behavior of nuclear bodies by live-cell imaging provides the researcher with important information regarding underlying mechanistic processes relating to their formation and maintenance. Two techniques have proved particularly valuable to our study of cellular dynamics and molecular mobility, namely, time-lapse imaging and fluorescence recovery after photobleaching (FRAP). Time-lapse microscopy allows for qualitative and quantitative analysis of a wide range of events at the cellular and subcellular level. FRAP provides a mechanism to study the mobility of a population of proteins in a range of conditions within discrete areas of the biological specimen. Therefore, fluorescence microscopy is unique in its ability to provide data at high temporal resolution and in such exquisite detail. PMID:25555575

Hutten, Saskia; Swift, Samuel; Lamond, Angus I

2015-01-01

229

NDE Imaging of Time Differential Terahertz Waves  

Science.gov (United States)

Natural voids are present in the vicinity of a conathane interface that bonds two different foam materials. These voids are out of focus with the terahertz imaging system and multiple optical reflections also make it difficult to determine their depths. However, waves passing through the top foam article at normal incidence are partially reflected at the denser conathane layer prior to total reflection at the tank s wall. Reflections embedded in the oscillating noise segment prior to the main signals can be extracted with dual applications of filtering and time derivative. Void's depth is computed from direct path's time of flight.

Trinh, Long B.

2008-01-01

230

Interactive Real-time Magnetic Resonance Imaging  

DEFF Research Database (Denmark)

Real-time acquisition, reconstruction and interactively changing the slice position using magnetic resonance imaging (MRI) have been possible for years. However, the current clinical use of interactive real-time MRI is limited due to an inherent low spatial and temporal resolution. This PhD project seeks to implement and assess existing reconstruction algorithms using multi-processors of modern graphics cards and many-core computer processors and to cover some of the potential clinical applications which might benefit from using an interactive real-time MRI system. First an off-line, but interactive, slice alignment tool was used to support the notion that 3D blood flow quantification in the heart possesses the ability to obtain curves and volumes which are not statistical different from standard 2D flow. Secondly, the feasibility of an interactive real-time MRI system was exploited with regard to optimal sampling strategy for detecting motion in four different anatomies on two different MRI scanner brands. A fully implemented interactive real-time MRI system was exploited in a group of healthy fetuses and proved its eligibility as an alternative diagnostic tool for fetal imaging. Finally, the system was used for 3D motion tracking of the liver, and its use was proposed for future integrations of MRI scanners and linear accelerators in the field of radiotherapy treatment.

Brix, Lau

2013-01-01

231

A time-dependent bacterial bioluminescence emission spectrum in an in vitro single turnover system : energy transfer alone cannot account for the yellow emission of Vibrio fischeri Y-1  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Yellow fluorescent protein (YFP), which has a bound FMN, was isolated from the marine bacterium Vibrio fischeri strain Y-1b. Its presence in a luciferase [alkanal monooxygenase (FMN-linked); alkanal, reduced-FMN:oxygen oxidoreductase (1-hydroxylating, luminescing), EC 1.14.14.3] reaction mixture causes a striking color change, and an increase in bioluminescence intensity, as well as a faster rate of intensity decay, so that the quantum yield is not changed. The emission spectrum shows two dis...

Eckstein, Jens W.; Cho, Ki Woong; Colepicolo, Pio; Ghisla, Sandro; Hastings, John Woodland; Wilson, The?re?se

1990-01-01

232

A time-dependent bacterial bioluminescence emission spectrum in an in vitro single turnover system: energy transfer alone cannot account for the yellow emission of Vibrio fischeri Y-1.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Yellow fluorescent protein (YFP), which has a bound FMN, was isolated from the marine bacterium Vibrio fischeri strain Y-1b. Its presence in a luciferase [alkanal monooxygenase (FMN-linked); alkanal, reduced-FMN:oxygen oxidoreductase (1-hydroxylating, luminescing), EC 1.14.14.3] reaction mixture causes a striking color change, and an increase in bioluminescence intensity, as well as a faster rate of intensity decay, so that the quantum yield is not changed. The emission spectrum shows two dis...

Eckstein, J. W.; Cho, K. W.; Colepicolo, P.; Ghisla, S.; Hastings, J. W.; Wilson, T.

1990-01-01

233

Bacteria bioluminescent activity as an indicator of geomagnetic disturbances  

International Nuclear Information System (INIS)

The effect of geomagnetic disturbances and storms on bioluminescence activity of bacterium were investigated. The bioluminescence intensity change depended on amplitude and continuous of geomagnetic storms. It is assumed, that the synchronization of luminous radiation take place in cellos when frequency of geomagnetic disturbances approached to an intrinsic one of a bioluminescence system. High sensitivity of bioluminescence of geomagnetic storms was detected. 5 refs., 4 figs

234

Bioluminescent bioreporter assays for targeted detection of chemical and biological agents  

Science.gov (United States)

Bioluminescent bioreporters carrying the bacterial lux gene cassette have been well established for the sensing and monitoring of select chemical agents. Their ability to generate target specific visible light signals with no requirement for extraneous additions of substrate or other hands-on manipulations affords a real-time, repetitive assaying technique that is remarkable in its simplicity and accuracy. Although the predominant application of lux-based bioluminescent bioreporters has been towards chemical compound detection, novel genetic engineering schemes are yielding a variety of new bioreporter systems that extend the lux sensing mechanism beyond mere analyte discrimination. For example, the unique specificity of bacteriophage (bacterial viruses) has been exploited in lux bioluminescent assays for specific identification of foodborne bacterial pathogens such as Escherichia coli O157:H7. With the concurrent ability to interface bioluminescent bioreporter assays onto integrated circuit microluminometers (BBICs; bioluminescent bioreporter integrated circuits), the potential exists for the development of sentinel microchips that can function as environmental monitors for multiplexed recognition of chemical and biological agents in air, food, and water. The size and portability of BBIC biosensors may ultimately provide a deployable, interactive network sensing technology adaptable towards chem/bio defense.

Ripp, Steven; Jegier, Pat; Johnson, Courtney; Moser, Scott; Islam, Syed; Sayler, Gary

2008-04-01

235

Understanding Bioluminescence in Dinoflagellates—How Far Have We Come?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Some dinoflagellates possess the remarkable genetic, biochemical, and cellular machinery to produce bioluminescence. Bioluminescent species appear to be ubiquitous in surface waters globally and include numerous cosmopolitan and harmful taxa. Nevertheless, bioluminescence remains an enigmatic topic in biology, particularly with regard to the organisms’ lifestyle. In this paper, we review the literature on the cellular mechanisms, molecular evolution, diversity, and ecology of bioluminescenc...

Martha Valiadi; Debora Iglesias-Rodriguez

2013-01-01

236

Time Variant Change Analysis in Satellite Images  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the time variant changes in satellite images using Self Organizing Feature Map (SOFM technique associated with Artificial Neural Network. In this paper, we take a satellite image and find the time variant changes using above technique with the help of MATLAB. This paper reviews remotely sensed data analysis with neural networks. First, we present an overview of the main concepts underlying Artificial Neural Networks (ANNs, including the main architectures and learning algorithms. Then, the main tasks that involve ANNs in remote sensing are described. We first make a brief introduction to models of networks, for then describing in general terms Artificial Neural Networks (ANNs. As an application, we explain the back propagation algorithm, since it is widely used and many other algorithms are derived from it. There are two techniques that are used for classification in pattern recognition such as Supervised Classification and Unsupervised Classification. In supervised learning technique the network knows about the target and it has to change accordingly to get the desired output corresponding to the presented input sample data. Most of the previous work has already been done on supervised classification. In this study we are going to present the classification of satellite images using unsupervised classification method of ANN.

Rachita Sharma

2013-05-01

237

Immobilized Bioluminescent Reagents in Flow Injection Analysis.  

Science.gov (United States)

Available from UMI in association with The British Library. Bioluminescent reactions exhibits two important characteristics from an analytical viewpoint; they are selective and highly sensitive. Furthermore, bioluminescent emissions are easily measured with a simple flow-through detector based on a photomultiplier tube and the rapid and reproducible mixing of sample and expensive reagent is best achieved by a flow injection manifold. The two most important bioluminescent systems are the enzyme (luciferase)/substrate (luciferin) combinations extracted from fireflies (Photinus pyralis) and marine bacteria (Virio harveyi) which requires ATP and NAD(P)H respectively as cofactors. Reactions that generate or consume these cofactors can also be coupled to the bioluminescent reaction to provide assays for a wide range of clinically important species. A flow injection manifold for the study of bioluminescent reactions is described, as are procedures for the extraction, purification and immobilization of firefly and bacterial luciferase and oxidoreductase. Results are presented for the determination of ATP using firefly system and the determination of other enzymes and substrates participating in ATP-converting reactions e.g. creatine kinase, ATP-sulphurylase, pyruvate kinase, creatine phosphate, pyrophosphate and phophoenolypyruvate. Similarly results are presented for the determination of NAD(P)H, FMN, FMNH_2 and several dehydrogenases which produce NAD(P)H and their substrates, e.g. alcohol, L-lactate, L-malate, L-glutamate, Glucose-6-phosphate and primary bile acid.

Nabi, Abdul

238

Fluorescence and bioluminescence of bacterial luciferase intermediates  

International Nuclear Information System (INIS)

An intermediate in the luciferase-catalyzed bioluminescent oxidation of FMNH2, isolated and purified by chromatography at --200, was postulated to be an oxygenated reduced flavine-luciferase. Maintained and studied at --20 to --300, this material exhibits a relatively weak fluorescence emission peaking at about 505 nm when excited at 370 nm. It may comprise more than one species. Upon continued exposure to light at 370 nm, the intensity of this fluorescence increases, often by a factor of 5 or more, and its emission spectrum is blue shifted to a maximum at about 485 nm. Upon warming this fluorescence is lost and the fluorescence of flavine mononucleotide appears. If warming is carried out in the presence of a long chain aldehyde, bioluminescence occurs, with the appearance of a similar amount of flavine fluorescence. The bioluminescence yield is about the same with irradiated and nonirradiated samples. The bioluminescence emission spectrum corresponds exactly to the fluorescence emission spectrum of the intermediate formed by irradiation, implicating the latter as being structurally close to the emitting species in bioluminescence. (auth)

239

Shear-stress dependence of dinoflagellate bioluminescence.  

Science.gov (United States)

Fluid flow stimulates bioluminescence in dinoflagellates. However, many aspects of the cellular mechanotransduction are incompletely known. The objective of our study was to formally test the hypothesis that flow-stimulated dinoflagellate bioluminescence is dependent on shear stress, signifying that organisms are responding to the applied fluid force. The dinoflagellate Lingulodinium polyedrum was exposed to steady shear using simple Couette flow in which fluid viscosity was manipulated to alter shear stress. At a constant shear rate, a higher shear stress due to increased viscosity increased both bioluminescence intensity and decay rate, supporting our hypothesis that bioluminescence is shear-stress dependent. Although the flow response of non-marine attached cells is known to be mediated through shear stress, our results indicate that suspended cells such as dinoflagellates also sense and respond to shear stress. Shear-stress dependence of flow-stimulated bioluminescence in dinoflagellates is consistent with mechanical stimulation due to direct predator handling in the context of predator-prey interactions. PMID:17565113

Maldonado, Elisa M; Latz, Michael I

2007-06-01

240

Papyrus imaging with terahertz time domain spectroscopy  

Science.gov (United States)

Terahertz time domain spectroscopic imaging (THz-TDSI) is a non-ionizing, non-contact and non-destructive measurement technique that has been recently utilized to study cultural heritage artifacts. We will present this technique and the results of non-contact measurements of papyrus texts, including images of hidden papyri. Inks for modern papyrus specimens were prepared using the historical binder, Arabic gum, and two common pigments used to write ancient texts, carbon black and red ochre. The samples were scanned in reflection at normal incidence with a pulse with a spectral range between 0.1 and 1.5 THz. Temporal analysis of the signals provides the depths of the layers, and their frequency spectra give information about the inks.

Labaune, J.; Jackson, J. B.; Pagès-Camagna, S.; Duling, I. N.; Menu, M.; Mourou, G. A.

2010-09-01

 
 
 
 
241

Sparsity reconstruction for bioluminescence tomography based on an augmented Lagrangian method  

Science.gov (United States)

Bioluminescence imaging (BLI) is an optical molecular imaging modality for monitoring physiological and pathological activities at the molecular level. The information of bioluminescent probe distribution in small animals can be threedimensionally and quantitatively obtained by bioluminescence tomography (BLT). Due to ill-posed nature, BLT may bear multiple solutions and aberrant reconstruction in the presence of measurement noise and optical parameter mismatches. Among different regularization methods, L2-type regularization strategy is the most popular and commonly-applied method, which minimizes the output-least-square formulation incorporated with the l2-norm regularization term to stabilize the problem. However, it often imposes over-smoothing on the reconstruction results. In contrast, for many practical applications, such as early detection of tumors, the volumes of the bioluminescent sources are very small compared with the whole body. In this paper, L1 regularization is used to fully take advantage of the sparsity prior knowledge and improve both efficiency and stability. And then a reconstruction method based on the augmented Lagrangian approach is proposed, which considers the BLT problem as the constrained optimization problem and employs the Bregman iterative method to deal with it. By using "divide and conquer" approach, the optimization problem can be exactly and fast solved by iteratively solving a sequence of unconstrained subproblems. To evaluate the performance of the proposed method in turbid mouse geometry, stimulate experiments with a heterogeneous 3D mouse atlas are conducted. In addition, physical experiments further demonstrate the potential of the proposed algorithm in practical applications.

Guo, Wei; Jia, Kebin; Tian, Jie; Han, Dong; Liu, Xueyan; Liu, Kai; Zhang, Qian; Feng, Jinchao; Qin, Chenghu

2012-03-01

242

A Multi-Camera System for Bioluminescence Tomography in Preclinical Oncology Research  

Directory of Open Access Journals (Sweden)

Full Text Available Bioluminescent imaging (BLI of cells expressing luciferase is a valuable noninvasive technique for investigating molecular events and tumor dynamics in the living animal. Current usage is often limited to planar imaging, but tomographic imaging can enhance the usefulness of this technique in quantitative biomedical studies by allowing accurate determination of tumor size and attribution of the emitted light to a specific organ or tissue. Bioluminescence tomography based on a single camera with source rotation or mirrors to provide additional views has previously been reported. We report here in vivo studies using a novel approach with multiple rotating cameras that, when combined with image reconstruction software, provides the desired representation of point source metastases and other small lesions. Comparison with MRI validated the ability to detect lung tumor colonization in mouse lung.

Ralph P. Mason

2013-07-01

243

Bacteria tracking by in vivo magnetic resonance imaging  

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Background: Different non-invasive real-time imaging techniques have been developed over the last decades to study bacterial pathogenic mechanisms in mouse models by following infections over a time course. In vivo investigations of bacterial infections previously relied mostly on bioluminescence imaging (BLI), which is able to localize metabolically active bacteria, but provides no data on the status of the involved organs in the infected host organism. In this study we established an in viv...

Ho?rr, V.; Tuchscherr, L.; Hu?ve, J.; Nippe, N.; Loser, K.; Glyvuk, N.; Tsytsyura, Y.; Holtkamp, M.; Sunderko?tter, C.; Karst, U.; Klingauf, J.; Peters, G.; Lo?ffler, B.; Faber, C.

2014-01-01

244

Spectral components of bioluminescence of aequorin and obelin.  

Science.gov (United States)

Complex bioluminescence spectra of photoproteins from marine coelenterates - jellyfish Aequorea victoria and hydroid Obelia longissima, and photoluminescence spectra of the bioluminescent reaction products (Ca(2+)-discharged photoproteins) were deconvolved into components. The bioluminescence spectra of aequorin were found to include three, the bioluminescence spectra of obelin - four, and the photoluminescence spectra of the Ca(2+)-discharged photoproteins - only two components. The spectral components were assigned to one unionized and three ionized forms of coelenteramide. The changes in acidity of the excited coelenteramide molecule are discussed. The differences in bioluminescence and photoluminescence spectra are considered, with protonic environment of coelenteramide taken into account. PMID:18602272

Belogurova, Nadezhda V; Kudryasheva, Nadezhda S; Alieva, Rosa R; Sizykh, Arnold G

2008-08-21

245

A Finite Element Mesh Aggregating Approach to Multiple-Source Reconstruction in Bioluminescence Tomography  

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A finite element mesh aggregating approach is presented to reconstruct images of multiple internal bioluminescence sources. Rather than assuming independence between mesh nodes, the proposed reconstruction strategy exploits spatial structure of nodes and aggregation feature of density distribution on the finite element mesh to adaptively determine the number of sources and to improve the quality of reconstructed images. With the proposed strategy integrated in the regularization-based reconst...

Shuyuan Yang; Jiao, L. C.; Fang Liu; Jingjing Yu; Xiaowei He

2011-01-01

246

Chemistry and biology of insect bioluminescence  

International Nuclear Information System (INIS)

Basic aspects on the Chemistry and Biology of bioluminescence are reviewed, with emphasis on insects. Data from the investigation of Lampyridae (fireflies) are collected from literature. With regard to Elateridae (click beetles) and Phengodidae (rail road worms), the least explored families of luminescent insects, new data are presented on the following aspects: (i) 'in vivo' emission spectra, (ii) chemical nature of the luciferin, (iii) conection between bioluminescence and 'oxygen toxicity' as a result of molecular oxygen storage and (iv) the role of light emission by larvae and pupae. (Author)

247

Observed and modeled bio-optical, bioluminescent, and physical properties during a coastal upwelling event in Monterey Bay, California  

Science.gov (United States)

During spring and summer time, coastal upwelling influences circulation and ecosystem dynamics of the Monterey Bay, California, which is recognized as a National Marine Sanctuary. Observations of physical, bio-optical properties (including bioluminescence) together with results from dynamical biochemical and bioluminescence models are used to interpret the development of the upwelling event during August 2003 in Monterey Bay, California. Observations and the biochemical model show the development of a phytoplankton bloom in the southern portion of Monterey Bay. Model results show an increase of nutrients in the southern portion of the bay, where nutrient-rich water masses are brought in by the southward flow and cyclonic circulation inside the bay. This increase in nutrients together with the sluggish circulation in the southern portion of the bay provides favorable conditions for phytoplankton growth. Our observations and models suggest that with the development of upwelling the offshore water masses with the subsurface layer of bioluminescent zooplankton were replaced by water masses advected from the northern coast of the bay with a relatively high presence of mostly nonbioluminescent phytoplankton. Inshore observations from autonomous underwater vehicles (AUVs) show consistent coincidence of chlorophyll, backscatter, and bioluminescence maxima during upwelling development. Offshore AUV observations (taken at the entrance to the bay) show a deeper bioluminescence maximum below the surface layers of high chlorophyll and backscatter values during the earlier stages of upwelling development. Later, the observed deep offshore bioluminescence maximum disappeared and became a shallower and much weaker signal, coinciding with high chlorophyll and backscatter values offshore. Based on the biochemical and bioluminescence models, a methodology for estimating the nighttime water-leaving radiance due to stimulated bioluminescence is demonstrated and evaluated.

Shulman, Igor; Moline, Mark A.; Penta, Bradley; Anderson, Stephanie; Oliver, Matthew; Haddock, Steven H. D.

2011-01-01

248

Modeling and measurement of a whole-cell bioluminescent biosensor based on a single photon avalanche diode.  

Science.gov (United States)

Whole-cell biosensors are potential candidates for on-line and in situ environmental monitoring. In this work we present a new design of a whole-cell bioluminescence biosensor for water toxicity detection, based on genetically engineered Escherichia coli bacteria, carrying a recA::luxCDABE promoter-reporter fusion. Sensitive optical detection is achieved using a single photon avalanche photodiode (SPAD) working in the Geiger mode. The present work describes a simple mathematical model for the kinetic process of the bioluminescence based SOS toxin response of E. coli bacteria. We find that initially the bioluminescence signal depends on the time square and we show that the spectral intensity of the bioluminescence signal is inverse proportional to the frequency. We get excellent agreement between the theoretical model and the measured light signal. Furthermore, we present experimental results of the bioluminescent signal measurement using a SPAD and a photomultiplier, and demonstrate improvement of the measurement by applying a matched digital filter. Low intensity bioluminescence signals were measured after the whole-cell sensors were exposed to various toxicant concentrations (5, 15 and 20ppm). PMID:18774705

Daniel, Ramiz; Almog, Ronen; Ron, Amit; Belkin, Shimshon; Diamand, Yosi Shacahm

2008-12-01

249

A review of the measurement and modelling of dinoflagellate bioluminescence  

Science.gov (United States)

Bioluminescence is a striking phenomenon that is ubiquitous throughout the world's oceans. Here we bring together the findings of in situ observations of bioluminescence in the upper ocean (bioluminescence within the upper ocean, as well as its relationships with other environmental parameters. As dinoflagellates are often the dominant source of stimulated bioluminescence in the upper ocean we review current knowledge regarding the bioluminescence of these organisms including its potential ecological function. Modelling and prediction of the bioluminescent field has previously had only limited success, especially over timescales greater than a few days. We suggest that the potential exists to improve the forecasting of upper ocean bioluminescence potential on longer, seasonal, timescales by utilising and improving methods to model dinoflagellates.

Marcinko, Charlotte L. J.; Painter, Stuart C.; Martin, Adrian P.; Allen, John T.

2013-02-01

250

Enhanced Landweber algorithm via Bregman iterations for bioluminescence tomography  

Science.gov (United States)

Bioluminescence tomography (BLT) is an important optical molecular imaging modality aimed at visualizing physiological and pathological processes at cellular and molecular levels. While the forward process of light propagation is described by the diffusion approximation to radiative transfer equation, BLT is the inverse problem to reconstruct the 3D localization and quantification of internal bioluminescent sources distribution. Due to the inherent ill-posedness of the BLT problem, regularization is generally indispensable to obtain more favorable reconstruction. In particular, total variation (TV) regularization is known to be effective for piecewise-constant source distribution which can permit sharp discontinuities and preserve edges. However, total variation regularization generally suffers from the unsatisfactory staircasing effect. In this work, we introduce the Bregman iterative regularization to alleviate this degeneration and enhance the numerical reconstruction of BLT. Based on the existing Landweber method (LM), we put forward the Bregman-LM-TV algorithm for BLT. Numerical experiments are carried out and preliminary simulation results are reported to evaluate the proposed algorithms. It is found that Bregman-LM-TV can significantly outperform the individual Landweber method for BLT when the source distribution is piecewise-constant.

Xia, Yi; Zhang, Meng

2014-09-01

251

A Short Image Series Based Scheme for Time Series Digital Image Correlation  

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A new scheme for digital image correlation, i.e., short time series DIC (STS-DIC) is proposed. Instead of processing the original deformed speckle images individually, STS-DIC combines several adjacent deformed speckle images from a short time series and then processes the averaged image, for which deformation continuity over time is introduced. The deformation of several adjacent images is assumed to be linear in time and a new spatial-temporal displacement representation m...

Wang, Xian; Ma, Shaopeng

2014-01-01

252

Amplitude metrics for cellular circadian bioluminescence reporters.  

Science.gov (United States)

Bioluminescence rhythms from cellular reporters have become the most common method used to quantify oscillations in circadian gene expression. These experimental systems can reveal phase and amplitude change resulting from circadian disturbances, and can be used in conjunction with mathematical models to lend further insight into the mechanistic basis of clock amplitude regulation. However, bioluminescence experiments track the mean output from thousands of noisy, uncoupled oscillators, obscuring the direct effect of a given stimulus on the genetic regulatory network. In many cases, it is unclear whether changes in amplitude are due to individual changes in gene expression level or to a change in coherence of the population. Although such systems can be modeled using explicit stochastic simulations, these models are computationally cumbersome and limit analytical insight into the mechanisms of amplitude change. We therefore develop theoretical and computational tools to approximate the mean expression level in large populations of noninteracting oscillators, and further define computationally efficient amplitude response calculations to describe phase-dependent amplitude change. At the single-cell level, a mechanistic nonlinear ordinary differential equation model is used to calculate the transient response of each cell to a perturbation, whereas population-level dynamics are captured by coupling this detailed model to a phase density function. Our analysis reveals that amplitude changes mediated at either the individual-cell or the population level can be distinguished in tissue-level bioluminescence data without the need for single-cell measurements. We demonstrate the effectiveness of the method by modeling experimental bioluminescence profiles of light-sensitive fibroblasts, reconciling the conclusions of two seemingly contradictory studies. This modeling framework allows a direct comparison between in vitro bioluminescence experiments and in silico ordinary differential equation models, and will lead to a better quantitative understanding of the factors that affect clock amplitude. PMID:25468350

St John, Peter C; Taylor, Stephanie R; Abel, John H; Doyle, Francis J

2014-12-01

253

Isolation and development of bioluminescent reporter phages for bacterial dysentery.  

Science.gov (United States)

Shigellosis is a significant cause of morbidity and mortality worldwide, most notably amongst children. Moreover, there is a global increase in the occurrence of multidrug-resistant isolates, including the epidemic and pandemic Shigella dysenteriae type 1 strain. We developed a bioluminescent reporter phage assay to facilitate detection and simultaneously determine antibiotic susceptibility. A Shigella flexneri phage (Shfl25875) was isolated from environmental wastewater and characterized by DNA sequencing. Shfl25875 is T4-like, harbors a 169,062-bp genome, and grows on most (28/29) S. flexneri strains and all 12 S. dysenteriae type 1 strains tested. The genes encoding bacterial luciferase were integrated into the Shfl25875 genome to create a "light-tagged" phage capable of transducing a bioluminescent phenotype to infected cells. Shfl25875::luxAB rapidly detects cultured isolates with high sensitivity. Specificity experiments indicate that the reporter does not respond to Shigella boydii, non-type 1?S. dysenteriae strains, and most non-Shigella Enterobacteriaceae. Shfl25875::luxAB generates ampicillin and ciprofloxacin susceptibility profiles that are similar to the standard Clinical and Laboratory Standards Institute (CLSI) growth microdilution method, but in a significantly shorter time. In addition, the reporter phage detects Shigella in mock-infected stool. This new reporter phage shows promise as a tool for the detection of cultured isolates or complex clinical samples. PMID:25252629

Schofield, D A; Wray, D J; Molineux, I J

2014-09-25

254

Practical application of bioluminescence enzyme immunoassay using enhancer for firefly luciferin-luciferase bioluminescence.  

Science.gov (United States)

Firefly luciferin-luciferase bioluminescence is known for its high quantum yield (41.0 ± 7.4%). Given this high quantum yield, application of this bioluminescence is expected to be useful in the field of clinical diagnostics. The kinetic profile of this bioluminescence exhibits an instant rise (pyrophosphate to prolong light emission. When these enhancers were used, luminescence was only decreased to 89, 83, 87 and 82% after 5 s, respectively. These materials modified the kinetic profile of bioluminescence so that the luminescence is more suitable for clinical application. It becomes more suitable because they enable highly sensitive integration and simplification of a device by separating luminescence measurements from dispensing of reagents. Using these enhancers, we then developed a bioluminescent enzyme immunoassay (BLEIA) for hepatitis B virus surface antigen (HBsAg) that employed firefly luciferase as a labeling enzyme. We compared the results obtained from the HBsAg BLEIA method with the conventional chemiluminescent enzyme immunoassay method, and found a satisfactory correlation (r=0.984, n=118). PMID:21681909

Minekawa, Takayuki; Ohkuma, Hiroshi; Abe, Katsushi; Maekawa, Hiroaki; Arakawa, Hidetoshi

2011-01-01

255

Reliability of a bioluminescence ATP assay for detection of bacteria.  

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The reliability of bioluminescence assays which employ the luciferin-luciferase ATP-dependent reaction to evaluate bacterial counts was studied, both in vitro and on urine specimens. Bioluminescence and cultural results for the most common urinary tract pathogens were analyzed. Furthermore, the influence of the culture medium, of the assaying method, and of the phase of growth on bioluminescence readings was studied. Results show that Proteus, Providencia, and Morganella strains are not corre...

Selan, L.; Berlutti, F.; Passariello, C.; Thaller, M. C.; Renzini, G.

1992-01-01

256

Dual monitoring using 124I-FIAU and bioluminescence for HSV1-tk suicide gene therapy  

International Nuclear Information System (INIS)

Herpes simplex virus type I thymidine kinase (HSV-tk) is the most common reporter gene and is used in cancer gene therapy with a prodrug nucleoside analog, ganciclovir (GCV). The aim of this study is to evaluate therapeutic efficacy of suicide gene therapy with 2'-fluoro-2'-deoxy-1-D-arabinofuranosyl-5-[124I] iodouracil (124I - FIAU) and bioluminescence in retrovirally HSV -tk and firefly luciferase transduced hepatoma model. The HSV -tk and firefly luciferase (Luc) was retrovirally transduced and expressed in MCA rat Morris hepatoma cells. Nude mice with subcutaneous tumors, MCA and MCA-TK-Luc, were subjected to GCV treatment (50mg/Kg/d intraperitoneally) for 5 day. PET imaging and biodistribution with (124I-FIAU) were performed at before and after initiation of therapy with GCV. Bioluminescent signal was also measured during GCV treatment. Before GCV treatment, no significant difference in tumor volume was found in tumors between MCA and MCA-TK-Luc. After GCV treatment, tumor volume of MCA-TK-Luc markedly reduced compared to that of MCA. In biodistribution study, 124I-FIAU uptake after GCV therapy significantly decreased compared with pretreatment levels (34.8 13.67 %ID/g vs 7.6 2.59 %ID/g) and bioluminescent signal was also significantly decreased compared with pretreatment levels. In small animal PET imaging, 124I-FIAU selectively localized in HSV -tk expressing tumor and the therapeutic efficacy of GCV treatmand the therapeutic efficacy of GCV treatment was evaluated by 124I-FIAU PET imaging. 124I-FIAU PET and bioluminescence imaging in HSV-tk suicide gene therapy were effective to evaluate the therapeutic response. 124I-FIAU may serve as an efficient and selective agent for monitoring of transduced HSV1-tk gene expression in vivo in clinical trials

257

Development of Bioluminescent Bioreporters for In Vitro and In Vivo Tracking of Yersinia pestis  

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Yersinia pestis causes an acute infection known as the plague. Conventional techniques to enumerate Y. pestis can be labor intensive and do not lend themselves to high throughput assays. In contrast, bioluminescent bioreporters produce light that can be detected using plate readers or optical imaging platforms to monitor bacterial populations as a function of luminescence. Here, we describe the development of two Y. pestis chromosomal-based luxCDABE bioreporters, LuxPtolC and LuxPcysZK. These...

Sun, Yanwen; Connor, Michael G.; Pennington, Jarrod M.; Lawrenz, Matthew B.

2012-01-01

258

Bioluminescence ATP Monitoring for the Routine Assessment of Food Contact Surface Cleanliness in a University Canteen  

Directory of Open Access Journals (Sweden)

Full Text Available ATP bioluminescence monitoring and traditional microbiological analyses (viable counting of total mesophilic aerobes, coliforms and Escherichia coli were used to evaluate the effectiveness of Sanitation Standard Operating Procedures (SSOP at a university canteen which uses a HACCP-based approach. To that end, 10 cleaning control points (CPs, including food contact surfaces at risk of contamination from product residues or microbial growth, were analysed during an 8-month monitoring period. Arbitrary acceptability limits were set for both microbial loads and ATP bioluminescence readings. A highly significant correlation (r = 0.99 between the means of ATP bioluminescence readings and the viable counts of total mesophilic aerobes was seen, thus revealing a strong association of these parameters with the level of surface contamination. Among CPs, the raw meat and multi-purpose chopping boards showed the highest criticalities. Although ATP bioluminescence technology cannot substitute traditional microbiological analyses for the determination of microbial load on food contact surfaces, it has proved to be a powerful tool for the real time monitoring of surface cleanliness at mass catering plants, for verify the correct application of SSOP, and hence for their implementation/revision in the case of poor hygiene.

Andrea Osimani

2014-10-01

259

Enumeration of bacterial cell numbers by amplified firefly bioluminescence without cultivation.  

Science.gov (United States)

We recently developed a novel bioluminescent enzymatic cycling assay for ATP and AMP with the concomitant use of firefly luciferase and pyruvate orthophosphate dikinase (PPDK), where AMP and pyrophosphate produced from ATP by firefly luciferase were converted back into ATP by PPDK. Background luminescence derived from contaminating ATP and AMP in the reagent was reduced using adenosine phosphate deaminase which degrades ATP, ADP, and AMP, resulting in constant and highly amplified bioluminescence with low background luminescence. To detect bacterial cells without cultivation, we applied the above bioluminescent enzymatic cycling reagent to rapid microbe detection system. ATP spots (0.31-5.0 amol/spot) at the level of a single bacterial cell were detected with 5 min signal integration, signifying that integrated luminescence was amplified 43 times in comparison to traditional ATP bioluminescence. Consequently, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Lactobacillus brevis in beer were detected without cultivation. Significant correlation was observed between the number of signal spots obtained using this novel system and the colony-forming units observed with the conventional colony-counting method (R(2)=0.973). PMID:12479834

Sakakibara, Tatsuya; Murakami, Seiji; Imai, Kazuhiro

2003-01-01

260

Real-time beam profile imaging system for actinotherapy accelerator  

International Nuclear Information System (INIS)

This paper describes a real-time beam profile imaging system for actinotheraphy accelerator. With the flash X-ray imager and the technique of digital image processing, a real-time 3-dimension dosage image is created from the intensity profile of the accelerator beam in real time. This system helps to obtain all the physical characters of the beam in any section plane, such as FWHM, penumbra, peak value, symmetry and homogeneity. This system has been used to acquire a 3-dimension dosage distribution of dynamic wedge modulator and the transient process of beam dosage. The system configure and the tested beam profile images are also presented

 
 
 
 
261

Transformation Experiment Using Bioluminescence Genes of "Vibrio fischeri."  

Science.gov (United States)

Bioluminescence transformation experiments show students the excitement and power of recombinant DNA technology. This laboratory experiment utilizes two plasmids of "Vibrio fischeri" in a transformation experiment. (LZ)

Slock, James

1995-01-01

262

Understanding Bioluminescence in Dinoflagellates—How Far Have We Come?  

Directory of Open Access Journals (Sweden)

Full Text Available Some dinoflagellates possess the remarkable genetic, biochemical, and cellular machinery to produce bioluminescence. Bioluminescent species appear to be ubiquitous in surface waters globally and include numerous cosmopolitan and harmful taxa. Nevertheless, bioluminescence remains an enigmatic topic in biology, particularly with regard to the organisms’ lifestyle. In this paper, we review the literature on the cellular mechanisms, molecular evolution, diversity, and ecology of bioluminescence in dinoflagellates, highlighting significant discoveries of the last quarter of a century. We identify significant gaps in our knowledge and conflicting information and propose some important research questions that need to be addressed to advance this research field.

Martha Valiadi

2013-09-01

263

Real-time evaluation of two light delivery systems for photodynamic disinfection of Candida albicans biofilm in curved root canals.  

Science.gov (United States)

Antimicrobial photodynamic therapy (APDT) combined with endodontic treatment has been recognized as an alternative approach to complement conventional root canal disinfection methods on bacterial biofilms. We developed an in  vitro model of bioluminescent Candida albicans biofilm inside curved dental root canals and investigated the microbial reduction produced when different light delivery methods are employed. Each light delivery method was evaluated in respect to the light distribution provided inside curved root canals. After conventional endodontic preparation, teeth were sterilized before canals were contaminated by a bioluminescent strain of C. albicans (CEC789). Methylene blue (90 ?M) was introduced into the canals and then irradiated (??=?660 nm, P?=?100 mW, beam diameter?=?2 mm) with laser tip either in contact with pulp chamber or within the canal using an optical diffuser fiber. Light distribution was evaluated by CCD camera, and microbial reduction was monitored through bioluminescence imaging. Our findings demonstrated that the bioluminescent C. albicans biofilm model had good reproducibility and uniformity. Light distribution in dental tissue was markedly dependent on the light delivery system, and this strategy was directly related to microbial destruction. Both light delivery systems performed significant fungal inactivation. However, when irradiation was performed with optical diffuser fiber, microbial burden reduction was nearly 100 times more effective. Bioluminescence is an interesting real-time analysis to endodontic C. albicans biofilm inactivation. APDT showed to be an effective way to inactivate C. albicans biofilms. Diffuser fibers provided optimized light distribution inside curved root canals and significantly increased APDT efficiency. PMID:25060900

Sabino, C P; Garcez, A S; Núñez, S C; Ribeiro, M S; Hamblin, M R

2014-07-25

264

Image-based EPI real time ghost correction  

Science.gov (United States)

This paper presents a new, real-time, ghost correction method for echo planar imaging (EPI) that has been implemented using the Imaging Calculation Environment (ICE) on a 3T Siemens MRI System. Conventional methods for correcting EPI image ghost are based on image phase correction or on a reference scan. This new method is also based on image phase correction, but uses a new algorithm for automatic determination of the phase correction, which allows entirely automated operation. With implementation of the new correction method in ICE, ghost-corrected images are automatically generated and loaded into the system's image database immediately after completion of each EPI scan. Experiments showed that this real time ghost correction method consistently reduced the ghost intensity in EPI images and improved overall image quality. On average, the ghost to signal ratio (GSR) improved from 13.0% to 3.2% using the new method.

Li, Shunshan; Buonocore, Michael H.

2008-03-01

265

Real-time acoustic radiation force impulse imaging  

Science.gov (United States)

Acoustic Radiation Force Impulse (ARFI) imaging uses short duration acoustic pulses to generate and subsequently determine localized displacements in tissue. Time delay estimators, such as normalized cross correlation and phase shift estimation, form the computational basis for ARFI imaging. This paper considers these algorithms and the effects of noise, interpolation, and quadrature demodulation on the accuracy of the time delay estimates. These results are used to implement a real-time ARFI imaging system and in an ex vivo liver ablation study.

Pinton, Gianmarco F.; McAleavey, Stephen A.; Dahl, Jeremy J.; Nightingale, Kathryn R.; Trahey, Gregg E.

2005-04-01

266

High hydrostatic pressure effects on bacterial bioluminescence  

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Consumers' demands for fresh-like food products that are free of microbial contamination have provided opportunities for high pressure processing applications. This technology can inactivate microbial vegetative cells while preserving food sensory and nutritional qualities. However, the mechanisms that promote this means of microbial inactivation have not been fully understood. In this study, a high-pressure system was developed to monitor cellular metabolism using in situ bioluminescence. Pr...

Duarte Gomez, Eileen Enid

2011-01-01

267

Rapid bioluminescence method for bacteriuria screening.  

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A study was performed to evaluate the UTIscreen (Los Alamos Diagnostics, Los Alamos, N. Mex.), a rapid bioluminescence bacteriuria screen. The UTIscreen was compared with three other rapid bacteriuria screens: the Bac-T-Screen (Vitek Systems, Hazelwood, Mo.), an automated filtration device; the Chemstrip LN (Boehringer Mannheim Diagnostics, BioDynamics, Indianapolis, Ind.), an enzyme dipstick; and the Gram stain. A semiquantitative plate culture was used as the reference method. Of the 1,000 ...

Pezzlo, M. T.; Ige, V.; Woolard, A. P.; Peterson, E. M.; La Maza, L. M.

1989-01-01

268

Bacterial bioluminescence as a bioassay for mycotoxins.  

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The use of bacterial bioluminescence as a toxicological assay for mycotoxins was tested with rubratoxin B, zearalenone, penicillic acid, citrinin, ochratoxin A, PR-toxin, aflatoxin B1, and patulin. The concentrations of mycotoxins causing 50% light reduction (EC50) in Photobacterium phosphoreum were determined immediately and at 5 h after reconstitution of the bacteria from a freeze-dried state. Generally, less toxins were required to obtain an EC50 at 5 h. The effects of the above mycotoxins...

Yates, I. E.; Porter, J. K.

1982-01-01

269

Rapid detection of bacteria in green tea using a novel pretreatment method in a bioluminescence assay.  

Science.gov (United States)

Tea is one of the most popular beverages consumed in the world, and green tea has become a popular beverage in Western as well as Asian countries. A novel pretreatment method for a commercial bioluminescence assay to detect bacteria in green tea was developed and evaluated in this study. Pretreatment buffers with pH levels ranging from 6.0 to 9.0 were selected from MES (morpholineethanesulfonic acid), HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid), or Tricine buffers. To evaluate the effect of pretreatment and the performance of the assay, serially diluted cultures of Enterobacter cloacae, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus were tested. The improved methods, which consisted of a pretreatment of the sample in alkaline buffer, significantly decreased the background bioluminescence intensity of green tea samples when compared with the conventional method. Pretreatment with alkaline buffers with pH levels ranging from 8.0 to 9.0 increased the bioluminescence intensities of cultures of E. cloacae and S. aureus. Strong log-linear relationships between the bioluminescence intensities and plate counts emerged for the tested strains. Furthermore, the microbial detection limit was 15 CFU in 500 ml of bottled green tea after an 8-h incubation at 35°C and an assay time of 1 h. The results showed that contaminated samples could be detected within 1 h of operation using our improved bioluminescence assay. This method could be used to test for contamination during the manufacturing process as well as for statistical sampling for quality control. PMID:24853516

Shinozaki, Yohei; Harada, Yasuhiro

2014-06-01

270

Local statistical analysis of real-time NRG images  

International Nuclear Information System (INIS)

An analysis of real-time neutron images, taken with the cyclotron-based neutron radiography system of Sumitomo Heavy Industries, Ltd., which uses a set of neutron-photon converter, LiF + ZnS (Ag) scintillation screen, and a high sensitive SIT television camera, is described. The fluctuation of image intensity at a constant neutron flux domain is well represented by a Poisson distribution and ripple noise appearing in the real-time image can be attributed to the deficiency of neutron flux. The image integration technique, therefore, would be effective for improvement of the statistical quality of neutron image. Some digital image processing techniques based on statistical method would be effective for a ruffled image like real-time neutron radiography. (author)

271

Real-time kidney ultrasound image segmentation: a prospective study  

Science.gov (United States)

Segmentation of ultrasound kidney images represents a challenge due to low quality data. Speckle, shadows, signal dropout and low contrast make segmentation a harsh task. In addition, kidney ultrasound imaging presents a great variability concerning the organ's shape on the image. This characteristic makes learning methods hard to use. The aim of this study is to develop a real time kidney ultrasound image segmentation method usable during surgical operations such as punctures. To deal with real time constraints, we decided to focus on region based methods and particularly split and merge algorithm. In this prospective study, the selection of the interesting area in the initial image is made by the physician, drawing a coarse bounding box around the organ. A pre-processing phase is first performed to correct image's artefacts. This phase is composed of three major steps. First, an image specification is made between the image to segment and a reference one. Then, a Haar wavelet filtering method is applied on the resulting image and finally an anisotropic diffusion filter is applied to smooth the result. Then, a split and merge algorithm is applied on the resulting image. Both split and merge criteria are based on regions statistics. Our method has been successfully applied on a set of 22 clinical images coming from 10 different patients and presenting different points of view regarding kidney's shape. We obtained very good results, for an average computational time of 8.5 seconds per image.

Dahdouh, S.; Frenoux, E.; Osorio, A.

2009-02-01

272

Iterative reconstruction for bioluminescence tomography with total variation regularization  

Science.gov (United States)

Bioluminescence tomography(BLT) is an instrumental molecular imaging modality designed for the 3D location and quantification of bioluminescent sources distribution in vivo. In our context, the diffusion approximation(DA) to radiative transfer equation(RTE) is utilized to model the forward process of light propagation. Mathematically, the solution uniqueness does not hold for DA-based BLT which is an inverse source problem of partial differential equations and hence is highly ill-posed. In the current work, we concentrate on a general regularization framework for BLT with Bregman distance as data fidelity and total variation(TV) as regularization. Two specializations of the Bregman distance, the least squares(LS) distance and Kullback-Leibler(KL) divergence, which correspond to the Gaussian and Poisson environments respectively, are demonstrated and the resulting regularization problems are denoted as LS+TV and KL+TV. Based on the constrained Landweber(CL) scheme and expectation maximization(EM) algorithm for BLT, iterative algorithms for the LS+TV and KL+TV problems in the context of BLT are developed, which are denoted as CL-TV and EM-TV respectively. They are both essentially gradient-based algorithms alternatingly performing the standard CL or EM iteration step and the TV correction step which requires the solution of a weighted ROF model. Chambolle's duality-based approach is adapted and extended to solving the weighted ROF subproblem. Numerical experiments for a 3D heterogeneous mouse phantom are carried out and preliminary results are reported to verify and evaluate the proposed algorithms. It is found that for piecewise-constant sources both CL-TV and EM-TV outperform the conventional CL and EM algorithms for BLT.

Jin, Wenma; He, Yonghong

2012-12-01

273

Use of the liquid scintillation spectrometer in bioluminescence analysis  

International Nuclear Information System (INIS)

This review covers publications concerning analytical bioluminescence which in the main have appeared between mid-1973 and mid-1976. Outlines of some new assays and techniques are given together with modifications of existing procedures. Comments are presented on the use of the liquid scintillation spectrometer and other equipment for measuring bioluminescence. New applications are detailed and discussed

274

A REVIEW OF ENVIRONMENTAL APPLICATIONS OF BIOLUMINESCENCE MEASUREMENTS  

Science.gov (United States)

This review of the recent literature on environmental applications of bioluminescence systems will focus on in vivo and in vitro bioluminescence methods that have been utilized to elucidate properties of chemicals, toxic and mutagenic effects, and to estimate biomass. The unifyin...

275

Single-cell bioluminescence and GFP in biofilm research  

Energy Technology Data Exchange (ETDEWEB)

Using flow cells and a combination of microscopy techniques, we can unequivocally identify single bacterial cells that express bioluminescent and fluorescent bioreporters. We have shown that, for attached cells, bioluminescence output within a bacterial strain can vary greatly from cell to cell.

Palmer, R.J. Jr, Sayler, G., White, D.C. [Tennessee Univ., Knoxville, TN (United States), Ctr. Env. Biotech; Phiefer, C. [Oak Ridge National Lab., TN (United States), Environmental Sciences Div.

1996-12-31

276

Dinoflagellate bioluminescence in response to mechanical stimuli in water flows  

Directory of Open Access Journals (Sweden)

Full Text Available Bioluminescence of plankton organisms induced by water movements has long been observed and is still under investigations because of its great complexity. In particular, the exact mechanism occurring at the level of the cell has not been yet fully understood. This work is devoted to the study of the bioluminescence of the dinoflagellates plankton species Pyrocystis noctiluca in response to mechanical stimuli generated by water flows. Several experiments were performed with different types of flows in a Couette shearing apparatus. All of them converge to the conclusion that stationary homogeneous laminar shear does not trigger massive bioluminescence, but that acceleration and shear are both necessary to stimulate together an intense bioluminescence response. The distribution of the experimental bioluminescence thresholds is finally calculated from the light emission response for the Pyrocystis noctiluca species.

A. S. Cussatlegras

2005-01-01

277

Bioluminescent bacteria: lux genes as environmental biosensors Bactérias bioluminescentes: os genes lux como biosensores ambientais  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in env...

Vânia da Silva Nunes-Halldorson; Norma Letícia Duran

2003-01-01

278

An excitation potential imaging condition for elastic reverse time migration  

Science.gov (United States)

Elastic reverse time migration (ERTM) has been demonstrated to be more accurate than scalar RTM. However, low efficiency (large storage and heavy calculated amount) and strong artifacts caused by the crosstalk between different wave modes are the two primary barriers to the application of the ERTM during the processing of real data. The scalar (P) and vector (S) potentials of the elastic wavefield and the arrival times corresponding to the first energy extremum of the wavefield are saved at each grid point during the forward modeling of the source wavefield. The angle-dependent reflection coefficient images are subsequently obtained by dividing the scalar and vector potentials of the backward extrapolated receiver wavefield by the saved scalar and vector potentials at the grid points that satisfy the image time at each time step, respectively. The proposed imaging condition does not need to store the snapshots of the source wavefield, while it can considerably improve the computational efficiency and decrease the amount of storage and Input/Output manipulation (compared with the cross-correlation imaging condition) in addition to suppressing the crosstalk between compressive and shear wave modes. Compared with the excitation time imaging condition, the proposed imaging condition reduces the energy loss caused by the opposite polarity of the horizontal component at opposite sides of the source in stacked images. Numerical tests with synthetic data of the Sigsbee2a model have demonstrated that this imaging condition is a cost-effective and practical imaging condition for use in prestack ERTM.

Gu, Bingluo; Liu, Youshan; Li, Zhiyuan; Ma, Xiaona; Liang, Guanghe

2014-09-01

279

Algorithm for localized adaptive diffuse optical tomography and its application in bioluminescence tomography  

Science.gov (United States)

A reconstruction algorithm for diffuse optical tomography based on diffusion theory and finite element method is described. The algorithm reconstructs the optical properties in a permissible domain or region-of-interest to reduce the number of unknowns. The algorithm can be used to reconstruct optical properties for a segmented object (where a CT-scan or MRI is available) or a non-segmented object. For the latter, an adaptive segmentation algorithm merges contiguous regions with similar optical properties thereby reducing the number of unknowns. In calculating the Jacobian matrix the algorithm uses an efficient direct method so the required time is comparable to that needed for a single forward calculation. The reconstructed optical properties using segmented, non-segmented, and adaptively segmented 3D mouse anatomy (MOBY) are used to perform bioluminescence tomography (BLT) for two simulated internal sources. The BLT results suggest that the accuracy of reconstruction of total source power obtained without the segmentation provided by an auxiliary imaging method such as x-ray CT is comparable to that obtained when using perfect segmentation.

Naser, Mohamed A.; Patterson, Michael S.; Wong, John W.

2014-04-01

280

Algorithm for localized adaptive diffuse optical tomography and its application in bioluminescence tomography.  

Science.gov (United States)

A reconstruction algorithm for diffuse optical tomography based on diffusion theory and finite element method is described. The algorithm reconstructs the optical properties in a permissible domain or region-of-interest to reduce the number of unknowns. The algorithm can be used to reconstruct optical properties for a segmented object (where a CT-scan or MRI is available) or a non-segmented object. For the latter, an adaptive segmentation algorithm merges contiguous regions with similar optical properties thereby reducing the number of unknowns. In calculating the Jacobian matrix the algorithm uses an efficient direct method so the required time is comparable to that needed for a single forward calculation. The reconstructed optical properties using segmented, non-segmented, and adaptively segmented 3D mouse anatomy (MOBY) are used to perform bioluminescence tomography (BLT) for two simulated internal sources. The BLT results suggest that the accuracy of reconstruction of total source power obtained without the segmentation provided by an auxiliary imaging method such as x-ray CT is comparable to that obtained when using perfect segmentation. PMID:24694875

Naser, Mohamed A; Patterson, Michael S; Wong, John W

2014-04-21

 
 
 
 
281

Real-time digital x-ray subtraction imaging  

International Nuclear Information System (INIS)

A method of producing visible difference images derived from an x-ray image of an anatomical subject is described. X-rays are directed through the subject, and the image is converted into television fields comprising trains of analog video signals. The analog signals are converted into digital signals, which are then integrated over a predetermined time corresponding to several television fields. Difference video signals are produced by performing a subtraction between the ongoing video signals and the corresponding integrated signals, and are converted into visible television difference images representing changes in the x-ray image

282

Chemiluminescence and bioluminescence past, present and future  

CERN Document Server

This complete and well-organized overview of chemiluminescence and bioluminescence is divided into two parts. The first covers historical developments and the fundamental principles of these phenomena before going on to review recent advances and instrumentation. The second part deals with the applications in a variety of research fields including life sciences, drug discovery, diagnostics, environment, agrofood, and forensics. The book is suitable not only for researchers currently employing detection techniques in their research activity, but also for those approaching the subject for the fi

Roda, Aldo; Hastings, J Woodland

2010-01-01

283

Real-time digital x-ray subtraction imaging  

International Nuclear Information System (INIS)

The invention provides a method of producing visible difference images derived from an X-ray image of an anatomical subject, comprising the steps of directing X-rays through the anatomical subject for producing an image, converting the image into television fields comprising trains of on-going video signals, digitally storing and integrating the on-going video signals over a time interval corresponding to several successive television fields and thereby producing stored and integrated video signals, recovering the video signals from storage and producing integrated video signals, producing video difference signals by performing a subtraction between the integrated video signals and the on-going video signals outside the time interval, and converting the difference signals into visible television difference images representing on-going changes in the X-ray image

284

THz time-domain spectroscopy imaging for mail inspection  

Science.gov (United States)

Acquiring messages from the mail but not destroying the envelope is a big challenge in the war of intelligence. If one can read the message of the mail when the envelope is closed, he will benefit from the message asymmetry and be on a good wicket in the competition. In this paper, we presented a transmitted imaging system using THz time-domain spectroscopy technology. We applied the system to image the mail inside an envelope by step-scanning imaging technology. The experimental results show that the THz spectroscopy can image the mail in an envelope. The words in the paper can be identified easily from the background. We also present the THz image of a metal blade in the envelope, in which we can see the metal blade clearly. The results show that it is feasible of THz Time-Domain Spectroscopy Imaging for mail inspection applications.

Zhang, Liquan; Wang, Zhongdong; Ma, Yanmei; Hao, Erjuan

2011-08-01

285

A Bioluminescence Assay Using Nitrosomonas europaea for Rapid and Sensitive Detection of Nitrification Inhibitors  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An expression vector for the luxAB genes, derived from Vibrio harveyi, was introduced into Nitrosomonas europaea. Although the recombinant strain produced bioluminescence due to the expression of the luxAB genes under normal growing conditions, the intensity of the light emission decreased immediately, in a time-and dose-dependent manner, with the addition of ammonia monooxygenase inhibitors, such as allylthiourea, phenol, and nitrapyrin. When whole cells were challenged with several nitrific...

Iizumi, Taro; Mizumoto, Masahiro; Nakamura, Kanji

1998-01-01

286

Photographic documentation in real time radiographic imaging procedures and other inspection procedures using video imaging techniques  

International Nuclear Information System (INIS)

With an automatic daylight video imaging system, based on the use of wet processing type of film, it is possible to produce permanent documents of real time video images with almost the same convenience as video tape recording while maintaining all the advantages of display flexibility and image quality offered by photographic documents

287

An ebCMOS camera system for marine bioluminescence observation: The LuSEApher prototype  

Energy Technology Data Exchange (ETDEWEB)

The ebCMOS camera, called LuSEApher, is a marine bioluminescence recorder device adapted to extreme low light level. This prototype is based on the skeleton of the LUSIPHER camera system originally developed for fluorescence imaging. It has been installed at 2500 m depth off the Mediterranean shore on the site of the ANTARES neutrino telescope. The LuSEApher camera is mounted on the Instrumented Interface Module connected to the ANTARES network for environmental science purposes (European Seas Observatory Network). The LuSEApher is a self-triggered photo detection system with photon counting ability. The presentation of the device is given and its performances such as the single photon reconstruction, noise performances and trigger strategy are presented. The first recorded movies of bioluminescence are analyzed. To our knowledge, those types of events have never been obtained with such a sensitivity and such a frame rate. We believe that this camera concept could open a new window on bioluminescence studies in the deep sea.

Dominjon, A., E-mail: a.dominjon@ipnl.in2p3.fr [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Ageron, M. [CNRS/IN2P3, Centre de Physique des Particules de Marseille, Marseille, F-13288 (France); Barbier, R. [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Universite de Lyon, Universite Lyon 1, Lyon F-69003 (France); Billault, M.; Brunner, J. [CNRS/IN2P3, Centre de Physique des Particules de Marseille, Marseille, F-13288 (France); Cajgfinger, T. [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Universite de Lyon, Universite Lyon 1, Lyon F-69003 (France); Calabria, P. [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Chabanat, E. [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France); Universite de Lyon, Universite Lyon 1, Lyon F-69003 (France); Chaize, D.; Doan, Q.T.; Guerin, C.; Houles, J.; Vagneron, L. [CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne F-69622 (France)

2012-12-11

288

Photo-real rendering of bioluminescence and iridescence in creatures from the abyss  

Science.gov (United States)

The generation of photo-real renderings of bioluminescence is developed for creatures from the abyss. Bioluminescence results from a chemical reaction with examples found in deep-sea marine environments including: algae, copepods, jellyfish, squid, and fish. In bioluminescence, the excitation energy is supplied by a chemical reaction, not by a source of light. The greatest transparency window in seawater is in the blue region of the visible spectrum. From small creatures like single-cell algae, to large species of siphonophore Praya dubia (40m), luminescent phenomena can be produced by mechanical excitement from disturbances of objects passing by. Deep sea fish, like the Pacific Black Dragonfish are covered with photophores along the upper and lower surfaces which emits light when disturbed. Other animals like small squids have several different types of light organs oscillating at different rates. Custom shaders and material phenomena incorporate indirect lighting like: global illumination, final gathering, ambient occlusion and subsurface scattering to provide photo real images. Species like the Hydomedusae jellyfish, produce colors that are also generated by iridescence of thin tissues. The modeling and rendering of these tissues requires thin film multilayer stacks. These phenomena are simulated by semi-rigid body dynamics in a procedural animation environment. These techniques have been applied to develop spectral rendering of scenes outside the normal visible window in typical computer animation render engines.

Prusten, Mark

2008-08-01

289

Spectrally resolved bioluminescence tomography with adaptive finite element analysis: methodology and simulation  

International Nuclear Information System (INIS)

As a molecular imaging technique, bioluminescence tomography (BLT) with its highly sensitive detection and facile operation can significantly reveal molecular and cellular information in vivo at the whole-body small animal level. However, because of complex photon transportation in biological tissue and boundary detection data with high noise, bioluminescent sources in deeper positions generally cannot be localized. In our previous work, we used achromatic or monochromatic measurements and an a priori permissible source region strategy to develop a multilevel adaptive finite-element algorithm. In this paper, we propose a spectrally solved tomographic algorithm with a posteriori permissible source region selection. Multispectral measurements, and anatomical and optical information first deal with the nonuniqueness of BLT and constrain the possible solution of source reconstruction. The use of adaptive mesh refinement and permissible source region based on a posteriori measures not only avoids the dimension disaster arising from the multispectral measured data but also reduces the ill-posedness of BLT and therefore improves the reconstruction quality. Reconsideration of the optimization method and related modifications further enhance reconstruction robustness and efficiency. We also incorporate into the method some improvements for reducing computational burdens. Finally, using a whole-body virtual mouse phantom, we demonstrate the capability of the proposed BLT algori the capability of the proposed BLT algorithm to reconstruct accurately bioluminescent sources in deeper positions. In terms of optical property errors and two sources of discernment in deeper positions, this BLT algorithm represents the unique predominance for BLT reconstruction

290

An ebCMOS camera system for marine bioluminescence observation: The LuSEApher prototype  

Science.gov (United States)

The ebCMOS camera, called LuSEApher, is a marine bioluminescence recorder device adapted to extreme low light level. This prototype is based on the skeleton of the LUSIPHER camera system originally developed for fluorescence imaging. It has been installed at 2500 m depth off the Mediterranean shore on the site of the ANTARES neutrino telescope. The LuSEApher camera is mounted on the Instrumented Interface Module connected to the ANTARES network for environmental science purposes (European Seas Observatory Network). The LuSEApher is a self-triggered photo detection system with photon counting ability. The presentation of the device is given and its performances such as the single photon reconstruction, noise performances and trigger strategy are presented. The first recorded movies of bioluminescence are analyzed. To our knowledge, those types of events have never been obtained with such a sensitivity and such a frame rate. We believe that this camera concept could open a new window on bioluminescence studies in the deep sea.

Dominjon, A.; Ageron, M.; Barbier, R.; Billault, M.; Brunner, J.; Cajgfinger, T.; Calabria, P.; Chabanat, E.; Chaize, D.; Doan, Q. T.; Guérin, C.; Houlès, J.; Vagneron, L.

2012-12-01

291

An ebCMOS camera system for marine bioluminescence observation: The LuSEApher prototype  

International Nuclear Information System (INIS)

The ebCMOS camera, called LuSEApher, is a marine bioluminescence recorder device adapted to extreme low light level. This prototype is based on the skeleton of the LUSIPHER camera system originally developed for fluorescence imaging. It has been installed at 2500 m depth off the Mediterranean shore on the site of the ANTARES neutrino telescope. The LuSEApher camera is mounted on the Instrumented Interface Module connected to the ANTARES network for environmental science purposes (European Seas Observatory Network). The LuSEApher is a self-triggered photo detection system with photon counting ability. The presentation of the device is given and its performances such as the single photon reconstruction, noise performances and trigger strategy are presented. The first recorded movies of bioluminescence are analyzed. To our knowledge, those types of events have never been obtained with such a sensitivity and such a frame rate. We believe that this camera concept could open a new window on bioluminescence studies in the deep sea.

292

Real-time image segmentation on a GPU  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Efficient segmentation of color images is important for many applications in computer vision. Non-parametric solutions are required in situations where little or no prior knowledge about the data is available. In this paper, we present a novel parallel image segmentation algorithm which segments images in real-time in a non-parametric way. The algorithm ?nds the equilibrium states of a Potts model in the superparamagnetic phase of the system. Our method maps perfectly onto the Graphics Proc...

Abramov, Alexey; Kulvicius, Toma?s; Wo?rgo?tter, Florentin; Dellen, Babette

2010-01-01

293

Real-time image segmentation on a GPU  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Efficient segmentation of color images is important for many applications in computer vision. Non-parametric solutions are required in situations where little or no prior knowledge about the data is available. In this paper, we present a novel parallel image segmentation algorithm which segments images in real-time in a non-parametric way. The algorithm finds the equilibrium states of a Potts model in the superparamagnetic phase of the system. Our method maps perfectly onto the Graphics...

Alexey, Abramov; Kulvicius, Tomas; Wo?rgo?tter, Florentin; Dellen, Babette

2010-01-01

294

Molecular Imaging of GSK3? and CK1? kinases  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Glycogen synthase kinase-3 (GSK3 ?) and casein kinase-1 alpha (CK-1?) are multifunctional kinases that play critical role in the regulation of a number of cellular processes. In spite of their importance, molecular imaging tools for non-invasive and real-time monitoring of their kinase activities have not been devised. Here, we report development of bioluminescent GSK3? and CK-1? reporter (BGCR) based on firefly luciferase complementation. Treatment of SW620 cells stably expressing the re...

Nyati, Shyam; Ranga, Rajesh; Ross, Brian D.; Rehemtulla, Alnawaz; Bhojani, Mahaveer Swaroop

2010-01-01

295

Adaptive Real Time Imaging Synthesis Telescopes  

CERN Document Server

The digital revolution is transforming astronomy from a data-starved to a data-submerged science. Instruments such as the Atacama Large Millimeter Array (ALMA), the Large Synoptic Survey Telescope (LSST), and the Square Kilometer Array (SKA) will measure their accumulated data in petabytes. The capacity to produce enormous volumes of data must be matched with the computing power to process that data and produce meaningful results. In addition to handling huge data rates, we need adaptive calibration and beamforming to handle atmospheric fluctuations and radio frequency interference, and to provide a user environment which makes the full power of large telescope arrays accessible to both expert and non-expert users. Delayed calibration and analysis limit the science which can be done. To make the best use of both telescope and human resources we must reduce the burden of data reduction. Our instrumentation comprises of a flexible correlator, beam former and imager with digital signal processing closely coupled...

Wright, Melvyn

2012-01-01

296

TIME-DELAY REGULARIZATION OF ANISOTROPIC DIFFUSION AND IMAGE PROCESSING  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study a time-delay regularization of the anisotropic diffusion model for image denoising of Malik and Perona, which has been proposed by Nitzberg and Shiota. In the two-dimensional case, we show the convergence of a numerical approximation and the existence of a weak solution. Finally, we show some experiments on images.

Belahmidi, Abdelmounim; Chambolle, Antonin

2005-01-01

297

Application of Wavelet Transform for Image Denoising of Spatially and Time Variable Astronomical Imaging Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report on our efforts to formulate algorithms for image signal processing with the spatially and time variant Point-Spread Function (PSF) and inhomogeneous noise of real imaging systems. In this paper we focus on application of the wavelet transform for denoising of the astronomical images with complicated conditions. They influence above all accuracy of the measurements and the new source detection ability. Our aim is to test the usefulness ofWavelet transform (as the standard image proce...

Blaz?ek, M.; Anisimova, E.; Pa?ta, P.

2011-01-01

298

Biochemistry and genetics of bacterial bioluminescence.  

Science.gov (United States)

Bacterial light production involves enzymes-luciferase, fatty acid reductase, and flavin reductase-and substrates-reduced flavin mononucleotide and long-chain fatty aldehyde-that are specific to bioluminescence in bacteria. The bacterial genes coding for these enzymes, luxA and luxB for the subunits of luciferase; luxC, luxD, and luxE for the components of the fatty acid reductase; and luxG for flavin reductase, are found as an operon in light-emitting bacteria, with the gene order, luxCDABEG. Over 30 species of marine and terrestrial bacteria, which cluster phylogenetically in Aliivibrio, Photobacterium, and Vibrio (Vibrionaceae), Shewanella (Shewanellaceae), and Photorhabdus (Enterobacteriaceae), carry lux operon genes. The luminescence operons of some of these bacteria also contain genes involved in the synthesis of riboflavin, ribEBHA, and in some species, regulatory genes luxI and luxR are associated with the lux operon. In well-studied cases, lux genes are coordinately expressed in a population density-responsive, self-inducing manner called quorum sensing. The evolutionary origins and physiological function of bioluminescence in bacteria are not well understood but are thought to relate to utilization of oxygen as a substrate in the luminescence reaction. PMID:25084994

Dunlap, Paul

2014-01-01

299

Energy transfer protein in coelenterate bioluminescence  

Energy Technology Data Exchange (ETDEWEB)

Bioluminescence in the sea pansy, Renilla reniformis, a marine anthozoan coelenterate, is a complex process involving the participation of three proteins. These are: (1) the luciferin-binding protein, (2) the enzyme luciferase, and (3) the green-fluorescent protein (GFP). Luciferin-binding protein is a specific subtrate-binding protein which binds one molecule of coelenterate-type luciferin per molecule of protein and which then releases luciferin in the presence of Ca/sup 2 +/. Luciferase is the enzyme which catalyzes oxidation (by O/sub 2/) of coelenterate-type luciferin, leading to the production of CO/sub 2/ and enzyme-bound excited-state oxyluciferin. Oxyluciferin may then emit blue light by a direct de-excitation pathway or may transfer excitation energy to GFP. GFP is a noncatalytic accessory protein which accepts excitation energy from oxyluciferin, by radiationless energy transfer, and then emits green bioluminescence. In this paper the purification methods and physicochemical characteristics of GFP from R. reniformis are presented, and in the companion article luciferin-binding protein is described.

Ward, W.W.; Cormier, M.J.

1979-01-01

300

Construction and validation of improved triple fusion reporter gene vectors for molecular imaging of living subjects.  

Science.gov (United States)

Multimodality imaging using several reporter genes and imaging technologies has become an increasingly important tool in determining the location(s), magnitude, and time variation of reporter gene expression in small animals. We have reported construction and validation of several triple fusion genes composed of a bioluminescent, a fluorescent, and a positron emission tomography (PET) reporter gene in cell culture and in living subjects. However, the bioluminescent and fluorescent components of fusion reporter proteins encoded by these vectors possess lesser activities when compared with the bioluminescent and fluorescent components of the nonfusions. In this study, we first created a mutant (mtfl) of a thermostable firefly luciferase (tfl) bearing the peroxisome localization signal to have greater cytoplasmic localization and improved access for its substrate, d-luciferin. Comparison between the three luciferases [mtfl, tfl, and firefly luciferase (fl)] both in cell culture and in living mice revealed that mtfl possessed 6- to 10-fold (in vitro) and 2-fold (in vivo) higher activity than fl. The improved version of the triple fusion vector carrying mtfl as the bioluminescent reporter component showed significantly (P bioluminescence than the previous triple fusion vectors. Of the three different red fluorescent reporter genes (jred, hcred, and mrfp1, isolated from jellyfish chromophore, coral Heteractis crispa, and coral Discosoma, respectively) evaluated, mrfp1 was able to preserve highest expression as a component of the triple fusion reporter gene for in vivo fluorescence imaging. A truncated version of wild-type herpes simplex virus 1 (HSV1) thymidine kinase gene (wttk) retained a higher expression level than the truncated mutant HSV1-sr39 TK (ttk) as the third reporter component of this improved triple fusion vector. Multimodality imaging of tumor-bearing mice using bioluminescence and microPET showed higher luciferase activity [(2.7 +/- 0.1 versus 1.9 +/- 0.1) x (10(6) p/s/cm(2)/sr)] but similar level of fluorine-18-labeled 2'-fluoro-2'-deoxyarabinofuranosyl-5-ethyluracil (18F-FEAU) uptake (1.37 +/- 0.15 versus 1.37 +/- 0.2) percentage injected dose per gram] by mtfl-mrfp1-wttk-expressing tumors compared with the fl-mrfp1-wttk-expressing tumors. Both tumors showed 4- to 5-fold higher accumulation (P bioluminescence, fluorescence, and microPET imaging techniques. PMID:17409415

Ray, Pritha; Tsien, Roger; Gambhir, Sanjiv Sam

2007-04-01

 
 
 
 
301

Analysis of time-varying psoriasis lesion image patterns  

DEFF Research Database (Denmark)

The multivariate alteration detection transform is applied to pairs of within and between time varying registered psoriasis image patterns. Color band contribution to the variates explaining maximal change is analyzed.

Maletti, Gabriela Mariel; ErsbØll, Bjarne Kjær

2004-01-01

302

Real-time absorption reduced surface fluorescence imaging  

Science.gov (United States)

We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f=0.5 mm-1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19 frames/s. This technique has potential in cancer visualization and tumor margin detection.

Yang, Bin; Tunnell, James W.

2014-09-01

303

Real time neutron image processing system in NRF  

International Nuclear Information System (INIS)

The neutron radiography facility was installed at the neutron radiography beam tube of the HANARO research reactor. The NRF is used for the nondestructive test to inspect and evaluate the material defect and homogeneity by detecting the transmitted neutron image in the nuclear as well as non-nuclear industry. To analyze the dynamical neutron image effectively and efficiently, the real-time image processing system was developed in background subtraction, normalization, geometry correction and beam uniformity, contrast control, filtering. The image quality test and dimension measurements were performed for the neutron beam purity and sensitivity indication. The NRF beam condition represents the highest beam quality for neutron radiography.

304

Real-time movie image enhancement in NMR  

International Nuclear Information System (INIS)

Clinical NMR motion picture (movie) images can now be produced routinely in real-time by ultra-high-speed echo-planar imaging (EPI). The single-shot image quality depends on both pixel resolution and signal-to-noise ratio (S/N), both factors being intertradeable. If image S/N is sacrificed rather than resolution, it is shown that S/N may be greatly enhanced subsequently without vitiating spatial resolution or foregoing real motional effects when the object motion is periodic. This is achieved by a Fourier filtering process. Experimental results are presented which demonstrate the technique for a normal functioning heart. (author)

305

Laminographic reconstruction from real-time radiographic images  

International Nuclear Information System (INIS)

We report the application of digital laminography reconstruction methods to real-time radiographic (RTR) images. Multiple digital images were acquired with the part at several orientations. Several acquisition and reconstruction methods have been investigated and their effects on the depth resolution and signal-to-noise ratio of the reconstructed images are discussed. The standard method yields the best signal-to-noise but the worst depth separation; the extreme value method yields the best depth separation with a slight decrease in signal-to-noise; and the iterative method is a compromise between the two. Both the extreme value and iterative methods require care in properly normalizing the projection images

306

Real-Time Face Pose Estimation from Single Range Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a real-time algorithm to estimate the 3D pose of a previously unseen face from a single range image. Based on a novel shape signature to identify noses in range images, we generate candidates for their positions, and then generate and evaluate many pose hypotheses in parallel using modern graphics processing units (GPUs). We developed a novel error function that compares the input range image to precomputed pose images of an average face model. The algorithm is robust to large pose...

Breitenstein, Michael D.; Kuettel, Daniel; Weise, Thibaut; Gool, Luc; Pfister, Hanspeter

2008-01-01

307

Time-resolved fast-neutron imaging with a pulse-counting image intensifier  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A new imaging method that combines high-efficiency fast-neutron detection with sub-ns time resolution is presented. This is achieved by exploiting the high neutron detection efficiency of a thick scintillator and the fast timing capability and flexibility of light-pulse detection with a dedicated image intensifier. The neutron converter is a plastic scintillator slab or, alternatively, a scintillating fibre screen. The scintillator is optically coupled to a pulse counting image intensifier wh...

Dangendorf, Volker

2007-01-01

308

Ca2+-regulated photoproteins: structural insight into the bioluminescence mechanism.  

Science.gov (United States)

The bioluminescent jellyfish has contributed two famous proteins to modern science: green fluorescent protein or GFP, which finds wide use as a probe in cell biology studies, and aequorin, which has been used for intracellular calcium measurement for more than 30 years. More recently, obelin, a protein from the bioluminescent hydroid and also in the family of what are called "Ca2+-regulated photoproteins", has been shown to have very attractive properties both in general applications and for basic structural biology investigations. This review will survey the new information into their molecular mechanism of bioluminescence action. PMID:15196050

Vysotski, Eugene S; Lee, John

2004-06-01

309

A short- time beltrami kernel for smoothing images and manifolds.  

Science.gov (United States)

We introduce a short-time kernel for the Beltrami image enhancing flow. The flow is implemented by "convolving" the image with a space dependent kernel in a similar fashion to the solution of the heat equation by a convolution with a Gaussian kernel. The kernel is appropriate for smoothing regular (flat) 2-D images, for smoothing images painted on manifolds, and for simultaneously smoothing images and the manifolds they are painted on. The kernel combines the geometry of the image and that of the manifold into one metric tensor, thus enabling a natural unified approach for the manipulation of both. Additionally, the derivation of the kernel gives a better geometrical understanding of the Beltrami flow and shows that the bilateral filter is a Euclidean approximation of it. On a practical level, the use of the kernel allows arbitrarily large time steps as opposed to the existing explicit numerical schemes for the Beltrami flow. In addition, the kernel works with equal ease on regular 2-D images and on images painted on parametric or triangulated manifolds. We demonstrate the denoising properties of the kernel by applying it to various types of images and manifolds. PMID:17547140

Spira, Alon; Kimmel, Ron; Sochen, Nir

2007-06-01

310

Real-time imaging of ATP release induced by mechanical stretch in human airway smooth muscle cells.  

Science.gov (United States)

Airway smooth muscle (ASM) cells within the airway walls are continually exposed to mechanical stimuli, and exhibit various functions in response to these mechanical stresses. ATP acts as an extracellular mediator in the airway. Moreover, extracellular ATP is considered to play an important role in the pathophysiology of asthma and chronic obstructive pulmonary disease. However, it is not known whether ASM cells are cellular sources of ATP secretion in the airway. We therefore investigated whether mechanical stretch induces ATP release from ASM cells. Mechanical stretch was applied to primary human ASM cells cultured on a silicone chamber coated with type I collagen using a stretching apparatus. Concentrations of ATP in cell culture supernatants measured by luciferin-luciferase bioluminescence were significantly elevated by cyclic stretch (12 and 20% strain). We further visualized the stretch-induced ATP release from the cells in real time using a luminescence imaging system, while acquiring differential interference contrast cell images with infrared optics. Immediately after a single uniaxial stretch for 1 second, strong ATP signals were produced by a certain population of cells and spread to surrounding spaces. The cyclic stretch-induced ATP release was significantly reduced by inhibitors of Ca(2+)-dependent vesicular exocytosis, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetraacetoxymethyl ester, monensin, N-ethylmaleimide, and bafilomycin. In contrast, the stretch-induced ATP release was not inhibited by a hemichannel blocker, carbenoxolone, or blockade of transient receptor potential vanilloid 4 by short interfering RNA transfection or ruthenium red. These findings reveal a novel property of ASM cells: mechanically induced ATP release may be a cellular source of ATP in the airway. PMID:24885163

Takahara, Norihiro; Ito, Satoru; Furuya, Kishio; Naruse, Keiji; Aso, Hiromichi; Kondo, Masashi; Sokabe, Masahiro; Hasegawa, Yoshinori

2014-12-01

311

Fast sensors for time-of-flight imaging applications.  

Science.gov (United States)

The development of sensors capable of detecting particles and radiation with both high time and high positional resolution is key to improving our understanding in many areas of science. Example applications of such sensors range from fundamental scattering studies of chemical reaction mechanisms through to imaging mass spectrometry of surfaces, neutron scattering studies aimed at probing the structure of materials, and time-resolved fluorescence measurements to elucidate the structure and function of biomolecules. In addition to improved throughput resulting from parallelisation of data collection - imaging of multiple different fragments in velocity-map imaging studies, for example - fast image sensors also offer a number of fundamentally new capabilities in areas such as coincidence detection. In this Perspective, we review recent developments in fast image sensor technology, provide examples of their implementation in a range of different experimental contexts, and discuss potential future developments and applications. PMID:24002354

Vallance, Claire; Brouard, Mark; Lauer, Alexandra; Slater, Craig S; Halford, Edward; Winter, Benjamin; King, Simon J; Lee, Jason W L; Pooley, Daniel E; Sedgwick, Iain; Turchetta, Renato; Nomerotski, Andrei; John, Jaya John; Hill, Laura

2014-01-14

312

A real time S-parameter imaging system  

International Nuclear Information System (INIS)

Obtaining a lateral S-parameter image scan from positrons implanted into semiconductor devices can be a helpful research tool both for localizing device structures and in diagnosing defect patterns that could help interpret function. S-parameter images can be obtained by electromagnetically rastering a variable energy positron beam of small spot size across the sample. Here we describe a general hardware and software architecture of relatively low cost that has recently been developed in our laboratory which allows the whole sub-surface S-parameter image of a sample or device to be obtained in real time. This system has the advantage over more conventional sequential scanning techniques of allowing the operator to terminate data collection once the quality of the image is deemed sufficient. As an example of the usefulness of this type of imaging architecture, S-parameter images of a representative sample are presented at two different position implantation energies. (author)

313

Real-time transfer and display of radiography image  

International Nuclear Information System (INIS)

The information process network of cobalt-60 container inspection system is a local area network based on PC. The system requires reliable transfer of radiography image between collection station and process station and the real-time display of radiography image on process station. Due to the very high data acquisition rate, in order to realize the real-time transfer and display of radiography image, 100 M Ethernet technology and network process communication technology are adopted in the system. Windows Sockets is the most common process communication technology up to now. Several kinds of process communication way under Windows Sockets technology are compared and tested. Finally the author realized 1 Mbyte/s' inerrant image transfer and real-time display with blocked datagram transfer technology

314

A Short Image Series Based Scheme for Time Series Digital Image Correlation  

CERN Document Server

A new scheme for digital image correlation, i.e., short time series DIC (STS-DIC) is proposed. Instead of processing the original deformed speckle images individually, STS-DIC combines several adjacent deformed speckle images from a short time series and then processes the averaged image, for which deformation continuity over time is introduced. The deformation of several adjacent images is assumed to be linear in time and a new spatial-temporal displacement representation method with eight unknowns is presented based on the subset-based representation method. Then, the model of STS-DIC is created and a solving scheme is developed based on the Newton-Raphson iteration. The proposed method is verified for numerical and experimental cases. The results show that the proposed STS-DIC greatly improves the accuracy of traditional DIC, both under simple and complicated deformation conditions, while retaining acceptable actual computational cost.

Wang, Xian

2014-01-01

315

Shedding light on bioluminescence regulation in Vibrio fischeri.  

Science.gov (United States)

The bioluminescence emitted by the marine bacterium Vibrio fischeri is a particularly striking result of individual microbial cells co-ordinating a group behaviour. The genes responsible for light production are principally regulated by the LuxR-LuxI quorum-sensing system. In addition to LuxR-LuxI, numerous other genetic elements and environmental conditions control bioluminescence production. Efforts to mathematically model the LuxR-LuxI system are providing insight into the dynamics of this autoinduction behaviour. The Hawaiian squid Euprymna scolopes forms a natural symbiosis with V. fischeri, and utilizes the symbiont-derived bioluminescence for certain nocturnal behaviours, such as counterillumination. Recent work suggests that the tissue with which V. fischeri associates not only can detect bioluminescence but may also use this light to monitor the V. fischeri population. PMID:22500943

Miyashiro, Tim; Ruby, Edward G

2012-06-01

316

Time-Frequency and Time-Scale-Based Fragile Watermarking Methods for Image Authentication  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two fragile image watermarking methods are proposed for image authentication. The first method is based on time-frequency analysis and the second one is based on time-scale analysis. For the first method, the watermark is chosen as an arbitrary nonstationary signal with a particular signature in the time-frequency plane. Experimental results show that this technique is very sensitive to many attacks such as cropping, scaling, translation, JPEG compression, and rotation, making it very...

Braham Barkat; Farook Sattar

2010-01-01

317

[Emissions from building products and investigation of their toxicity with the bioluminescence inhibition test].  

Science.gov (United States)

The investigation of building products in test chambers contains so far only analytical and sensory measurements. In this paper, first experiments for the direct testing of the acute toxicity of building product emissions with the bioluminescence inhibition test are presented. The test specimen was a solvent-free dispersion paste for gluing carpets. Two tests with different air change rates were performed in a 1 m3 stainless steel test chamber. The emissions were concentrated at uniform timesteps in impinger-bottles and measured with the bioluminescence inhibition test. At the same time the concentrations of the emissions in the test chamber were measured both with charcoal adsorbent tubes (carbon disulphide desorption) and with tenax tubes (thermal desorption). The results of the bioluminescence inhibition test show, that the decrease of the toxicity over a period of 28 days is far lower at a low air change rate than at a higher air change rate. We also found, that from the multitude of the emitted substances the toxicity for the luminescence bacteria was only caused by Ethanol-[2-(2-butoxyethoxy)]-acetate. PMID:9916292

Mücke, W; Blum, M; Hunstein, R

1998-12-01

318

Using bacterial bioluminescence to evaluate the impact of biofilm on porous media hydraulic properties.  

Science.gov (United States)

Biofilm formation in natural and engineered porous systems can significantly impact hydrodynamics by reducing porosity and permeability. To better understand and characterize how biofilms influence hydrodynamic properties in porous systems, the genetically engineered bioluminescent bacterial strain Pseudomonas fluorescens HK44 was used to quantify microbial population characteristics and biofilm properties in a translucent porous medium. Power law relationships were found to exist between bacterial bioluminescence and cell density, fraction of void space occupied by biofilm (i.e. biofilm saturation), and hydraulic conductivity. The simultaneous evaluation of biofilm saturation and porous medium hydraulic conductivity in real time using a non-destructive approach enabled the construction of relative hydraulic conductivity curves. Such information can facilitate simulation studies related to biological activity in porous structures, and support the development of new models to describe the dynamic behavior of biofilm and fluid flow in porous media. The bioluminescence based approach described here will allow for improved understanding and control of industrially relevant processes such as biofiltration and bioremediation. PMID:25479429

Bozorg, Ali; Gates, Ian D; Sen, Arindom

2014-12-01

319

Bioluminescence regenerative cycle (BRC) system: theoretical considerations for nucleic acid quantification assays.  

Science.gov (United States)

A novel application of bioluminescence for nucleic acid quantification, the bioluminescence regenerative cycle (BRC), is described in theoretical terms and supported by preliminary experimental data. In the BRC system, pyrophosphate (PPi) molecules are released during biopolymerization and are counted and correlated to DNA copy number. The enzymes ATP-sulfurylase and firefly luciferase are employed to generate photons quantitatively from PPi. Enzymatic unity-gain positive feedback is implemented to amplify photon generation and to compensate for decay in light intensity by self-regulation. The cumulative total of photons can be orders of magnitude higher than in typical chemiluminescent processes. A system level theoretical model is developed, taking into account the kinetics of the regenerative cycle, contamination, and detector noise. Data and simulations show that the photon generation process achieves steady state for the time range of experimental measurements. Based on chain reaction theory, computations show that BRC is very sensitive to variations in the efficiencies of the chemical reactions involved and less sensitive to variations in the quantum yield of the process. We show that BRC can detect attomolar quantities of DNA (10(-18) mol), and that the useful dynamic range is five orders of magnitude. Sensitivity is not constrained by detector performance but rather by background bioluminescence caused by contamination by either PPi or ATP (adenosine triphosphate). PMID:15882922

Hassibi, Arjang; Contag, Christopher; Vlad, Marcel O; Hafezi, Maryam; Lee, Thomas H; Davis, Ronald W; Pourmand, Nader

2005-08-01

320

Mesoscopic relaxation time of dynamic image correlation spectroscopy  

Directory of Open Access Journals (Sweden)

Full Text Available Dynamical images contain useful information of how the objects behave in time and space. When the system is in biological fluids, the motion of the object is much over-damped; the relaxation time is the characteristics in a diffusive time scale. We have found dynamical states of melting and forming of small nematic domains (10—30 ?m that are exhibited in the suspensions of fd-viruses under applied AC electric field amplitude at low frequency. Dynamic image correlation function is used for extracting the mes- oscopic relaxation times of the dynamical states, which can be employed as an application to other dynamic imaging process of biologically relevant soft condensed matter and biomedical systems.

Kyongok Kang

2010-06-01

 
 
 
 
321

Image-Based Learning Approach Applied to Time Series Forecasting  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, a new learning approach based on time-series image information is presented. In order to implementthis new learning technique, a novel time-series input data representation is also defined. This input datarepresentation is based on information obtained by image axis division into boxes. The difference between this newinput data representation and the classical is that this technique is not time-dependent. This new information isimplemented in the new Image-Based Learning Approach (IBLA and by means of a probabilistic mechanism thislearning technique is applied to the interesting problem of time series forecasting. The experimental results indicatethat by using the methodology proposed in this article, it is possible to obtain better results than with the classicaltechniques such as artificial neuronal networks and support vector machines.

J. C. Chimal-Eguía

2012-06-01

322

Shedding light on bioluminescence regulation in Vibrio fischeri  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The bioluminescence emitted by the marine bacterium Vibrio fischeri is a particularly striking result of individual microbial cells coordinating a group behavior. The genes responsible for light production are principally regulated by the LuxR-LuxI quorum-sensing system. In addition to LuxR-LuxI, numerous other genetic elements and environmental conditions control bioluminescence production. Efforts to mathematically model the LuxR-LuxI system are providing insight into the dynamics of this a...

Miyashiro, Tim; Ruby, Edward G.

2012-01-01

323

Dinoflagellate bioluminescence in response to mechanical stimuli in water flows  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bioluminescence of plankton organisms induced by water movements has long been observed and is still under investigations because of its great complexity. In particular, the exact mechanism occurring at the level of the cell has not been yet fully understood. This work is devoted to the study of the bioluminescence of the dinoflagellates plankton species Pyrocystis noctiluca in response to mechanical stimuli generated by water flows. Several experiments were performed with different types of ...

Cussatlegras, A. S.; Le Gal, P.

2005-01-01

324

Pixel timing correction in time-lapsed calcium imaging using point scanning microscopy.  

Science.gov (United States)

In point scanning imaging, data are acquired by sequentially scanning each pixel of a predetermined area. This way of scanning leads to time delays between pixels, especially for lower scanning speed or large scanned areas. Therefore, experiments are often performed at lower framerates in order to ensure a sufficient signal-to-noise ratio, even though framerates above 30 frames per second are technically feasible. For these framerates, we suggest that it becomes crucial to correct the time delay between image pixels prior to analyses. In this paper, we apply temporal interpolation (or pixel timing correction) for calcium imaging in two-photon microscopy as an example of fluorescence imaging. We present and compare three interpolation methods (linear, Lanczos and cubic B-spline). We test these methods on a simulated network of coupled bursting neurons at different framerates. In this network, we introduce a time delay to simulate a scanning by point scanning microscopy. We also assess these methods on actual microscopic calcium imaging movies recorded at usual framerates. Our numerical results suggest that point scanning microscopy imaging introduces statistically significant time delays between image pixels at low frequency. However, we demonstrate that pixel timing correction compensates for these time delays, regardless of the used interpolation method. PMID:25128722

Boiroux, Dimitri; Oke, Yoshihiko; Miwakeichi, Fumikazu; Oku, Yoshitaka

2014-11-30

325

Real-time terahertz imaging for art conservation science  

Science.gov (United States)

A new real-time terahertz imaging system has been developed by using a quantum cascade laser source and a microbolometer focal plane detector array. The application to non-invasive analyses of cultural heritage is demonstrated with an oil paint specimen. The experimental results suggested that the terahertz imaging system can identify materials based on a spectral database with a spatial resolution of about 300 ?m. The transmission imaging indicated the difference between natural and artificial ultramarine pigments. Since the size of the system is similar to a common portable infrared camera, it can be used at the place where the object is located, such as museums, and can contribute to conservation activities, such as drying process monitoring. This real-time, small, non-invasive terahertz imaging system can be used in various fundamental research fields and practical industries.

Fukunaga, K.; Sekine, N.; Hosako, I.; Oda, N.; Yoneyama, H.; Sudou, T.

2008-08-01

326

Time-Reversal Acoustics and Maximum-Entropy Imaging  

Energy Technology Data Exchange (ETDEWEB)

Target location is a common problem in acoustical imaging using either passive or active data inversion. Time-reversal methods in acoustics have the important characteristic that they provide a means of determining the eigenfunctions and eigenvalues of the scattering operator for either of these problems. Each eigenfunction may often be approximately associated with an individual scatterer. The resulting decoupling of the scattered field from a collection of targets is a very useful aid to localizing the targets, and suggests a number of imaging and localization algorithms. Two of these are linear subspace methods and maximum-entropy imaging.

Berryman, J G

2001-08-22

327

Time-resolved PHERMEX image restorations constrained with an additional multiply-exposed image  

International Nuclear Information System (INIS)

There are a number of possible industrial and scientific applications of nanosecond cineradiographs. Although the technology exists to produce closely spaced pulses of x rays for this application, the quality of the time-resolved radiographs is severely limited. The limitations arise from the necessity of using a fluorescent screen to convert the transmitted x rays to light and then using electro-optical imaging systems to gate and to record the images with conventional high-speed cameras. It has been proposed that, in addition to the time-resolved images, a conventional multiply exposed radiograph be obtained. This report uses both PHERMEX and conventional photographic simulations to demonstrate that the additional information supplied by the multiply exposed radiograph can be used to improve the quality of digital image restorations of the time-resolved pictures over what could be achieved with the degraded images alone

328

Observations of wild hunting behaviour and bioluminescence of a large deep-sea, eight-armed squid, Taningia danae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Our newly developed underwater high definition video camera system took the first live images of adults of the mesopelagic large squid, Taningia danae, between 240 and 940?m deep off Ogasawara Islands, western North Pacific. The resulting footage includes attacking and bioluminescence behaviours, and reveals that T. danae is far from the sluggish neutrally buoyant deep-sea squid previously suspected. It can actively swim both forward and backward freely by flapping its large muscular triang...

Kubodera, Tsunemi; Koyama, Yasuhiro; Mori, Kyoichi

2007-01-01

329

Real-time evaluation of aggregation using confocal imaging and image analysis tools.  

Science.gov (United States)

Real-time confocal imaging was utilised to monitor the in situ loss of BSA monomers and aggregate formation using Spatial Intensity Distribution Analysis (SpIDA) and Raster Image Correlation Spectroscopy (RICS). At the proof of concept level this work has demonstrated the applicability of RICS and SpIDA for monitoring protein oligomerisation and larger aggregate formation. PMID:24324999

Hamrang, Zahra; Zindy, Egor; Clarke, David; Pluen, Alain

2014-02-01

330

Time-resolved imaging of solid phantoms for optical mammography.  

Science.gov (United States)

We have recorded time-resolved transillumination images of solid phantoms with objects embedded that differ in their scattering and absorption coefficients from those of the bulk material, simulating a compressed human breast with a tumor inside. Employing time-correlated single photon counting at rates of up to 1 MHz, we recorded distributions of times of flight of photons at 1369 scan positions within 2.5 min. Several quantities, such as fractional transmittance, first moments, Fourier amplitudes, phase shifts, and frequency-dependent effective transport scattering and absorption coefficients, have been derived from experimental data to form two-dimensional images. By recording such images at a selected total number of photons detected, we have determined the contrast and effective signal-to-noise ratio in each case. PMID:18250662

Grosenick, D; Wabnitz, H; Rinneberg, H

1997-01-01

331

Real-time particle image velocimetry based on FPGA technology  

International Nuclear Information System (INIS)

Particle image velocimetry (PIV), based on laser sheet, is a method for image processing and calculation of distributed velocity fields.It is well established as a fluid dynamics measurement tool, being applied to liquid, gases and multiphase flows.Images of particles are processed by means of computationally demanding algorithms, what makes its real-time implementation difficult.The most probable displacements are found applying two dimensional cross-correlation function. In this work, we detail how it is possible to achieve real-time visualization of PIV method by designing an adaptive embedded architecture based on FPGA technology.We show first results of a physical field of velocity calculated by this platform system in a real-time approach.

332

A real-time reconstruction system for magnetic resonance imaging.  

Science.gov (United States)

A digital-electronic reconstruction system for MRI has been designed and demonstrated. The system is capable of reconstructing a 128 x 128 pixel image from complex-valued data in approximately 8 ms (122 frames per second) or a 256 x 256 pixel image in 32 ms (30 frames per second) using the standard 2D FFT reconstruction algorithm. Real-time MR imaging can be obtained when this reconstruction system is coupled with fast continuous echo-planar type data acquisition. This provides the unique potential for real-time monitoring of interventional procedures or for rapid patient positioning. The real-time reconstruction system presented here consists of four main subsystems: an analog to digital converter, an interface memory, the Fourier processor, and the display processor. The basic design of this reconstruction system is presented along with results, demonstrating the capability of the system. PMID:8722825

Gmitro, A F; Ehsani, A R; Berchem, T A; Snell, R J

1996-05-01

333

Real-Time Ellipsometry-Based Transmission Ultrasound Imaging  

Energy Technology Data Exchange (ETDEWEB)

Ultrasonic imaging is a valuable tool for non-destructive evaluation and medical diagnosis. Reflection mode is exclusively used for medical imaging, and is most frequently used for nondestructive evaluation (NDE) because of the relative speed of acquisition. Reflection mode imaging is qualitative, yielding little information about material properties, and usually only about material interfaces. Transmission imaging can be used in 3D reconstructions to yield quantitative information: sound speed and attenuation. Unfortunately, traditional scanning methods of acquiring transmission data are very slow, requiring on the order of 20 minutes per image. The sensing of acoustic pressure fields as optical images can significantly speed data acquisition. An entire 2D acoustic pressure field can be acquired in under a second. The speed of data acquisition for a 2D view makes it feasible to obtain multiple views of an object. With multiple views, 3D reconstruction becomes possible. A fast, compact (no big magnets or accelerators), inexpensive, 3D imaging technology that uses no ionizing radiation could be a boon to the NDE and medical communities. 2D transmission images could be examined in real time to give the ultrasonic equivalent of a fluoroscope, or accumulated in such a way as to acquire phase and amplitude data over multiple views for 3D reconstruction (for breast cancer imaging, for example). Composite panels produced for the aircraft and automobile industries could be inspected in near real time, and inspection of attenuating materials such as ceramics and high explosives would be possible. There are currently three optical-readout imaging transmission ultrasound technologies available. One is based on frustrated total internal reflection (FTIR) [1,2], one on Fabry-Perot interferometry [3], and another on critical angle modulation [4]. Each of these techniques has its problems. The FTIR based system cannot currently be scaled to large aperture sizes, the Fabry-Perot system has never been fully implemented for area imaging, and the critical angle modulation system is not sensitive enough for medical imaging. We proposed an entirely new way of using acoustic pressure to modulate a light beam. This new technology should be sensitive enough to be useful for medical imaging and have a large enough aperture to speed acquisition by orders of magnitude over point sampling. Unfortunately, we were unable to bring this technology to fruition.

Kallman, J S; Poco, J F; Ashby, A E

2007-02-14

334

Experimental ultrasound system for real-time synthetic imaging  

DEFF Research Database (Denmark)

Digital signal processing is being employed more and more in modern ultrasound scanners. This has made it possible to do dynamic receive focusing for each sample and implement other advanced imaging methods. The processing, however, has to be very fast and cost-effective at the same time. Dedicated chips are used in order to do real time processing. This often makes it difficult to implement radically different imaging strategies on one platform and makes the scanners less accessible for research purposes. Here flexibility is the prime concern, and the storage of data from all transducer elements over 5 to 10 seconds is needed to perform clinical evaluation of synthetic and 3D imaging. This paper describes a real-time system specifically designed for research purposes. The purpose of the system is to make it possible to acquire multi-channel data in real-time from clinical multi-element ultrasound transducers, and to enable real-time or near realtime processing of the acquired data. The system will be capable of performing the processing for the currently available imaging methods, and will make it possible to perform initial trials in a clinical environment with new imaging modalities for synthetic aperture imaging, 2D and 3D B-mode and velocity imaging. The system can be used with 128 element transducers and can excite 128 channels and receive and sample data from 64 channels simultaneously at 40 MHz with 12 bits precision. Data can be processed in real time using the system's 80 signal processing units or it can be stored directly in RAM. The system has 24 GBytes RAM and can thus store 8 seconds of multi-channel data. It is fully software programmable and its signal processing units can also be reconfigured under software control. The control of the system is done over an Ethernet using C and Matlab. Programs for doing e.g. B-mode imaging can directly be written in Matlab and executed on the system over the net from any workstation running Matlab. The overall system concept is presented and an example ofa 20 lines script for doing phased array B-mode imaging is presented.

Jensen, JØrgen Arendt; Holm, Ole

1999-01-01

335

Investigation of real-time remote palpation imaging  

Science.gov (United States)

We are investigating a novel ultrasonic method for remote palpation, which provides images of local variations in tissue stiffness. Acoustic radiation force is applied to small volumes of tissue, and the resulting displacement patterns are imaged using ultrasonic correlation based techniques. Tissue displacements are inversely proportional to tissue stiffness, thus a stiffer region of tissue exhibits smaller displacements than a more compliant region. This method also provides information about tissue recovery after force cessation. We will present in vivo experimental results demonstrating the feasability of this method. Using intensities ranging from 120 to 300 W/cm2, peak displacements of up to 50 microns were observed after 1.4 milliseconds of force application. The tissue moved to its peak displacement within 3 milliseconds of force application, and the time constants for tissue recovery varied with tissue type. Tissue displacements appeared to be correlated with tissue structure in matched B-mode images. To our knowledge, these results represent the first in vivo soft tissue images generated using radiation force. These findings support the feasibility of Remote Palpation imaging. We will discuss the technical, safety, and clinical challenges of implementing a real-time Remote Palpation imaging system on a commercial diagnostic scanner.

Nightingale, Kathryn R.; Soo, Mary S.; Nightingale, Roger W.; Trahey, Gregg E.

2001-05-01

336

Robust real-time instrument tracking in ultrasound images  

Science.gov (United States)

Minimally invasive surgery in combination with ultrasound (US) imaging imposes high demands on the surgeon's hand-eye-coordination capabilities. A possible solution to reduce these requirements is minimally invasive robotic surgery in which the instrument is guided by visual servoing towards the goal defined by the surgeon in the US image. This approach requires robust tracking of the instrument in the US image sequences which is known to be difficult due to poor image quality. This paper presents algorithms and results of first tracking experiments. Adaptive thresholding based on Otsu's method allows to cope with large intensity variations of the instrument echo. Median filtering of the binary image and subsequently applied morphological operations suppress noise and echo artefacts. A fast run length code based labelling algorithm allows for real-time labelling of the regions. A heuristic exploiting region size and region velocity helps to overcome ambiguities. The overall computation time is less than 20 ms per frame on a standard PC. The tracking algorithm requires no information about texture and shape which are known to be very unreliable in US image sequences. Experimental results for two different instrument materials (polyvinyl chloride and polyurethane) are given, showing the performance of the proposed approach. Choosing the appropriate material, trajectories are smooth and only few outliers occur.

Ortmaier, Tobias; Vitrani, Marie-Aude; Morel, Guillaume; Pinault, Samuel

2005-04-01

337

A novel parallel architecture for real-time image processing  

Science.gov (United States)

A novel DSP/FPGA-based parallel architecture for real-time image processing is presented in this paper, DSPs are the main processing unit and FPGAs are used to be logic units for image interface protocol, image processing, image display, synchronization communication portocol of DSPs and DSP's reprogramming interface of 422/485. The presented architecture is composed of two modules: the preprocessing module and the processing module, and the latter is extendable for better performance. Modules are connected by LINK communication port, whose LVDS protocol has the ability of anti-jamming. And DSP's programs can be updated easily by 422/485 with PC's serial port. Analysis and experiments result shows that the prototype with the proposed parallel architecture has many promising charactersitics such as powerful computing capability, broad data transfer bandwidth, and is easy to be extended and updated.

Hu, Junhong; Zhang, Tianxu; Zhong, Sheng; Chen, Xujun

2009-10-01

338

Communication: Time- and space-sliced velocity map electron imaging.  

Science.gov (United States)

We develop a new method to achieve slice electron imaging using a conventional velocity map imaging apparatus with two additional components: a fast frame complementary metal-oxide semiconductor camera and a high-speed digitizer. The setup was previously shown to be capable of 3D detection and coincidence measurements of ions. Here, we show that when this method is applied to electron imaging, a time slice of 32 ps and a spatial slice of less than 1 mm thick can be achieved. Each slice directly extracts 3D velocity distributions of electrons and provides electron velocity distributions that are impossible or difficult to obtain with a standard 2D imaging electron detector. PMID:25494725

Lee, Suk Kyoung; Lin, Yun Fei; Lingenfelter, Steven; Fan, Lin; Winney, Alexander H; Li, Wen

2014-12-14

339

IMPLEMENTATION OF IMAGE PROCESSING IN REAL TIME CAR PARKING SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Car parking lots are an important object class in many traffic and civilian applications. With the problems of increasing urban trafficcongestion and the ever increasing shortage of space, these car parking lots are needed to be well equipped with automatic parkingInformation and Guidance systems. Goals of intelligent parking lot management include counting the number of parked cars, and identifyingthe available location. This work proposes a new system for providing parking information and guidance using image processing. The proposed system includes counting the number of parked vehicles, and dentifying the stalls available. The system detects cars through images instead of using electronic sensors embedded on the floor. A camera is installed at the entry point of the parking lot. It capturesimage sequences. The image sequences are then analyzed using digital image processing for vehicle detection and according to the status ofvehicle occupancy inside, real time guidance and information is provided to the incoming driver.

SAYANTI BANERJEE,

2011-02-01

340

Communication: Time- and space-sliced velocity map electron imaging  

Science.gov (United States)

We develop a new method to achieve slice electron imaging using a conventional velocity map imaging apparatus with two additional components: a fast frame complementary metal-oxide semiconductor camera and a high-speed digitizer. The setup was previously shown to be capable of 3D detection and coincidence measurements of ions. Here, we show that when this method is applied to electron imaging, a time slice of 32 ps and a spatial slice of less than 1 mm thick can be achieved. Each slice directly extracts 3D velocity distributions of electrons and provides electron velocity distributions that are impossible or difficult to obtain with a standard 2D imaging electron detector.

Lee, Suk Kyoung; Lin, Yun Fei; Lingenfelter, Steven; Fan, Lin; Winney, Alexander H.; Li, Wen

2014-12-01

 
 
 
 
341

Monitoring tumor response to radiation therapy with longitudinal and multimodal molecular imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: Metabolic changes induced by radiation therapy (RT) provide a biological measure of tumor response to treatment beyond anatomic changes. In this preclinical study we investigated these changes through longitudinal monitoring of tumor response to varying doses of RT with 18F-Fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and Computed Tomography (CT), as well as bioluminescence imaging (BLI). We sought to establish the metabolic alterations in irradiated tumors at early time...

Perez, Jessica

2010-01-01

342

Real-time quantitative phase imaging for cell studies  

Science.gov (United States)

Most biological cells are not clearly visible with a bright field microscope. Several methods have been developed to improve contrast in cell imaging, including use of exogenous contrast agents such as fluorescence microscopy, as well as utilizing properties of light-specimen interaction for optics design, to reveal the endogenous contrast, such as phase contrast microscopy (PCM) and differential interference contrast (DIC) microscopy. Although PCM and DIC methods significantly improve the image contrast without the need for staining agents, they only provide qualitative information about the phase change induced by the cells as light passes through them. Quantitative phase imaging (QPI) has recently emerged as an effective imaging tool which provides not only better image contrast but also cell-induced phase shifts in the optical pathlength, thus allowing nanometer-scale measurements of structures and dynamics of the cells. Other important aspects of an imaging system are its imaging speed and throughput. High-throughput, high-speed, real-time quantitative phase imaging with high spatial and temporal sensitivity is highly desirable in many applications including applied physics and biomedicine. In this dissertation, to address this need, I discuss the development of such an imaging system that includes the white light diffraction phase microscopy (wDPM), a new optical imaging method, and image reconstruction/analysis algorithms using graphics processing units (GPUs). wDPM can measure optical pathlength changes at nanometer scale both spatially and temporally with single-shot image acquisition, enabling very fast imaging. I also exploit the broadband spectrum of white light used as the light source in wDPM to develop a system called spectroscopic diffraction phase microscopy (sDPM). This sDPM system allows QPI measurements at several wavelengths, which solves the problem of thickness and refractive index coupling in the phase shifts induced by the cell, and which also may help visualize more-complex cell structures. Owing to its high spatial and temporal sensitivity and single-shot acquisition, wDPM enables measurement of nanometer-scale dynamic processes of cells at very high rate and measurement of cell growth because of the linear relationship between a cell-induced phase shift and its dry mass. The parallel algorithms and software tools I developed allow real-time QPI imaging and online image analysis at frame rates of up to 40 megapixel-size images per second. This capability allows very high throughput of several thousands of cells in imaging mode and eliminates the need of storing the images since we only need to store processed data, which is much smaller in storage size. Finally, I present the capability of the system by showing an application in red blood cell screening, which can be used as a diagnostic tool in blood testing and may pave the way for digital hematology and remote diagnostics.

Pham, Hoa Vinh

343

Time-resolved neutron imaging at ANTARES cold neutron beamline  

CERN Document Server

In non-destructive evaluation with X-rays light elements embedded in dense, heavy (or high-Z) matrices show little contrast and their structural details can hardly be revealed. Neutron radiography, on the other hand, provides a solution for those cases, in particular for hydrogenous materials, owing to the large neutron scattering cross section of hydrogen and uncorrelated dependency of neutron cross section on the atomic number. The majority of neutron imaging experiments at the present time is conducted with static objects mainly due to the limited flux intensity of neutron beamline facilities and sometimes due to the limitations of the detectors. However, some applications require the studies of dynamic phenomena and can now be conducted at several high intensity beamlines such as the recently rebuilt ANTARES beam line at the FRM-II reactor. In this paper we demonstrate the capabilities of time resolved imaging for repetitive processes, where different phases of the process can be imaged simultaneously and...

Tremsin, A S; Tittelmeier, K; Schillinger, B; Schulz, M; Lerche, M; Feller, W B

2015-01-01

344

In Vivo Real Time Volumetric Synthetic Aperture Ultrasound Imaging  

DEFF Research Database (Denmark)

Synthetic aperture (SA) imaging can be used to achieve real-time volumetric ultrasound imaging using 2-D array transducers. The sensitivity of SA imaging is improved by maximizing the acoustic output, but one must consider the limitations of an ultrasound system, both technical and biological. This paper investigates the in vivo applicability and sensitivity of volumetric SA imaging. Utilizing the transmit events to generate a set of virtual point sources, a frame rate of 25 Hz for a 90° x 90° field-of-view was achieved. Data were obtained using a 3.5 MHz 32 x 32 elements 2-D phased array transducer connected to the experimental scanner (SARUS). Proper scaling is applied to the excitation signal such that intensity levels are in compliance with the U.S. Food and Drug Administration regulations for in vivo ultrasound imaging. The measured Mechanical Index and spatial-peak- temporal-average intensity for parallel beamforming (PB) are 0.83 and 377.5mW/cm2, and for SA are 0.48 and 329.5mW/cm2. A human kidney was volumetrically imaged with SA and PB techniques simultaneously. Two radiologists for evaluation of the volumetric SA were consulted by means of a questionnaire on the level of details perceivable in the beamformed images. The comparison was against PB based on the in vivo data. The feedback from the domain experts indicates that volumetric SA images internal body structures with a better contrast resolution compared to PB at all positions in the entire imaged volume. Furthermore, the autocovariance of a homogeneous area in the in vivo SA data, had 23.5% smaller width at the half of its maximum value compared to PB.

Bouzari, Hamed; Rasmussen, Morten Fischer

2015-01-01

345

Fast sensors for time-of-flight imaging applications.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The development of sensors capable of detecting particles and radiation with both high time and high positional resolution is key to improving our understanding in many areas of science. Example applications of such sensors range from fundamental scattering studies of chemical reaction mechanisms through to imaging mass spectrometry of surfaces, neutron scattering studies aimed at probing the structure of materials, and time-resolved fluorescence measurements to elucidate the structure and fu...

Vallance, C.; Brouard, M.; Lauer, A.; Slater, Cs; Halford, E.; Winter, B.; King, Sj; Lee, Jw; Pooley, DE; Sedgwick, I.; Turchetta, R.; Nomerotski, A.; John, Jj; Hill, L.

2014-01-01

346

Update on time-of-flight PET imaging  

Science.gov (United States)

Time-of-flight (TOF) PET was initially introduced in the early days of PET. TOF PET scanners developed in the 1980s had limited sensitivity and spatial resolution, operated in 2D mode with septa, and used analytic image reconstruction methods. Current generation of TOF PET scanners have the highest sensitivity and spatial resolution ever achieved in commercial whole-body PET, operate in fully-3D mode, and use iterative reconstruction with full system modeling. Previously, it was shown that TOF provides a gain in image signal-to-noise-ratio (SNR) that is proportional to the square root of the object size divided by the system timing resolution. With oncologic studies being the primary application of PET, more recent work has shown that in modern TOF PET scanners there is an improved trade-off between lesion contrast, image noise, and total imaging time, leading to a combination of improved lesion detectability, reduced scan time or injected dose, and more accurate and precise lesion uptake measurement. The benefit of TOF PET is also higher for heavier patients, which leads to a more uniform clinical performance over all patient sizes. PMID:25525181

Surti, Suleman

2015-01-01

347

Time-resolved fast neutron imaging: simulation of detector performance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We have analyzed and compared the performance of two novel fast-neutron imaging methods with time-of-flight spectroscopy capability. Using MCNP and GEANT code simulations of neutron and charged-particle transport in the detectors, key parameters such as detection efficiency, the amount of energy deposited in the converter and the spatial resolution of both detector variants have been evaluated.

Vartsky, D.; Mor, I.; Goldberg, M. B.; Mardor, I.; Feldman, G.; Bar, D.; Shor, A.; Dangendorf, V.; Laczko, G.; Breskin, A.; Chechik, R.

2004-01-01

348

Vegetable seed radiosensitivity and kinetic analysis of super-weak bioluminescence  

International Nuclear Information System (INIS)

Bioluminescence of several vegetable seeds induced by ?-rays was studied. The results show that positive relation exists between seeds bioluminescence and irradiation dose, which fits with equation Y=Y0eKD. The higher the K value is, the more intense the bioluminescence induced by ?-rays is. Significant differences among K values were found with different varieties. The bioluminescence and exterior measurement value of seed radiosensitivity showed good consistency

349

Bubble masks for time-encoded imaging of fast neutrons.  

Energy Technology Data Exchange (ETDEWEB)

Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

2013-09-01

350

The global ultraviolet imager (GUVI) for the NASA TIMED mission  

International Nuclear Information System (INIS)

The Global Ultraviolet Imager (GUVI) investigation is designed to provide quantitative observations and interpretation of the Earth's airglow and auroral emissions in support of the NASA Thermosphere, Ionosphere, Mesosphere, Energy and Dynamics (TIMED) mission. It will address TIMED objectives dealing with energetics, dynamics, and the specification of state variables. The instrument will provide multiple-wavelength, simultaneous ''monochromatic'' images of the far-ultraviolet emission (115 to 180 nm) using a scan mirror to sweep the instantaneous field of view of a spectrographic imager through an arc of up to 140 degree aligned perpendicular to the orbit plane of the spacecraft. The instantaneous field of view is 11.8 degree by 0.37 degree (adjustable) along the slit and perpendicular to the slit, respectively. The field of view is mapped to a two-dimensional image plane with up to 64 spatial pixels by 160 spectral pixels of spectral width 0.4 nm per pixel. Binning of pixels can be performed along both the spatial and spectral axes of the array to reduce the demands on the downlink telemetry. The f/3 Rowland circle scanning spectrographic imager is outfitted with a toroidal grating ruled at 1,200 grooves per millimeter. The fore-optics consist of a plane scanning mirror and an off-axis parabolic telescope. The detector is a photon-counting microchannel plate with a wedge and strip anode mounted in a sealed tube

351

Real-time synthetic aperture imaging: opportunities and challenges  

DEFF Research Database (Denmark)

Synthetic aperture (SA) ultrasound imaging has not been introduced in commercial scanners mainly due to the computational cost associated with the hardware implementation of this imaging modality. SA imaging redefines the term beamformed line. Since the acquired information comes from all points in the region of interest it is possible to beamform the signals along a desired path, thus, improving the estimation of blood flow. The transmission of coded excitations makes it possible to achieve higher contrast and larger penetration depth compared to "conventional" scanners. This paper presents the development and implementation of the signal processing stages employed in SA imaging: compression of received data acquired using codes, and beamforming. The goal was to implement the system using commercially available field programmable gate arrays. The compression filter operates on frequency modulated pulses with duration of up to 50 mus sampled at 70 MHz. The beamformer can process data from 256 channels at a pulse repetition frequency of 5000 Hz and produces 192 lines of 1024 complex samples in real time. The lines are described by their origin, direction, length and distance between two samples in 3D. This parametric description makes it possible to quickly change the image geometry during scanning, thus enabling adaptive imaging and precise flow estimation. The paper addresses problems such as large bandwidth and computational load and gives the solutions that have been adopted for the implementation.

Nikolov, Svetoslav; Tomov, Borislav Gueorguiev

2006-01-01

352

Rapid detection (4 h) of methicillin-resistant Staphylococcus aureus by a bioluminescence method.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A 4-h bioluminescence method for methicillin susceptibility determination was compared with reference methods. Of the Staphylococcus aureus strains tested, 80 were methicillin resistant, 180 were methicillin susceptible, and 10 were borderline susceptible. There was 100% correlation between bioluminescence and reference methods for methicillin-susceptible and methicillin-resistant strains. All borderline-susceptible strains were identified as methicillin resistant by bioluminescence.

Park, C. H.; Hixon, D. L.; Mclaughlin, C. M.; Cook, J. F.

1988-01-01

353

Real-time image histogram equalization using FPGA  

Science.gov (United States)

A new hardware implementation of histogram equalization by means of Field Programmable Gate Array (FPGA) is presented. Histogram equalization is an effective means of image enhancement. Its real-time processing requires a great deal of memory and very high processing speed. The logic cell nature of XC4000 family's FPGA is most suitable for performing real-time pixel-level image processing operations such as histogram equalization. A core is constructed to complete this histogram statistics and histogram equalization. As a result, the chip makes circuits and system more effective than ever, and it takes very short time to complete the calculation and generate the look-up table. The equalizing technique is described and implementation results using a Xilinx XC4010 FPGA are presented.

Li, Xiying; Ni, GuoQiang; Cui, Yanmei; Pu, Tian; Zhong, Yanli

1998-08-01

354

Bioluminescence to reveal structure and interaction of coastal planktonic communities  

Science.gov (United States)

Ecosystem function will in large part be determined by functional groups present in biological communities. The simplest distinction with respect to functional groups of an ecosystem is the differentiation between primary and secondary producers. A challenge thus far has been to examine these groups simultaneously with sufficient temporal and spatial resolution for observations to be relevant to the scales of change in coastal oceans. This study takes advantage of general differences in the bioluminescence flash kinetics between planktonic dinoflagellates and zooplankton to measure relative abundances of the two groups within the same-time space volume. This novel approach for distinguishing these general classifications using a single sensor is validated using fluorescence data and exclusion experiments. The approach is then applied to data collected from an autonomous underwater vehicle surveying >500 km in Monterey Bay and San Luis Obispo Bay, CA during the summers of 2002-2004. The approach also reveals that identifying trophic interaction between the two planktonic communities may also be possible.

Moline, Mark A.; Blackwell, Shelley M.; Case, James F.; Haddock, Steven H. D.; Herren, Christen M.; Orrico, Cristina M.; Terrill, Eric

2009-02-01

355

Time series analysis of brain regional volume by MR image  

International Nuclear Information System (INIS)

The present study proposed a methodology of time series analysis of volumes of frontal, parietal, temporal and occipital lobes and cerebellum because such volumetric reports along the process of individual's aging have been scarcely presented. Subjects analyzed were brain images of 2 healthy males and 18 females of av. age of 69.0 y, of which T1-weighted 3D SPGR (spoiled gradient recalled in the steady state) acquisitions with a GE SIGNA EXCITE HD 1.5T machine were conducted for 4 times in the time series of 42-50 months. The image size was 256 x 256 x (86-124) voxels with digitization level 16 bits. As the template for the regions, the standard gray matter atlas (icbn452atlasprobabilitygray) and its labeled one (icbn.Labels), provided by UCLA Laboratory of Neuro Imaging, were used for individual's standardization. Segmentation, normalization and coregistration were performed with the MR imaging software SPM8 (Statistic Parametric Mapping 8). Volumes of regions were calculated as their voxel ratio to the whole brain voxel in percent. It was found that the regional volumes decreased with aging in all above lobes examined and cerebellum in average percent per year of -0.11, -0.07, -0.04, -0.02, and -0.03, respectively. The procedure for calculation of the regional volumes, which has been manually operated hitherto, can be automatically conducted for the individual brain using the standard atlases above. (T.T.) above. (T.T.)

356

Time required to stabilize thermographic images at rest  

Science.gov (United States)

Thermography for scientific research and practical purposes requires a series of procedures to obtain images that should be standardized; one of the most important is the time required for acclimatization in the controlled environment. Thus, the objective of this study was to identify the appropriate acclimatization time in rest to reach a thermal balance on young people skin. Forty-four subjects participated in the study, 18 men (22.3 ± 3.1 years) and 26 women (21.7 ± 2.5 years). Thermographic images were collected using a thermal imager (Fluke®), totaling 44 images over a period of 20 min. The skin temperature (TSK) was measured at the point of examination which included the 0 min, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20. The body regions of interest (ROI) analyzed included the hands, forearms, arms, thighs, legs, chest and abdomen. We used the Friedman test with post hoc Dunn's in order to establish the time at rest required to obtain a TSK balance and the Mann-Whitney test was used to compare age, BMI, body fat percentage and temperature variations between men and women, considering always a significance level of p women had significantly higher temperature variations than men (p women, the anterior abdomen and thighs, and the posterior part of the hands, forearms and abdomen showed significant differences (p women is variable, but for whole body analysis it is recommended at least 10 min for both sexes.

Marins, João Carlos Bouzas; Moreira, Danilo Gomes; Cano, Sergio Piñonosa; Quintana, Manuel Sillero; Soares, Danusa Dias; Fernandes, Alex de Andrade; Silva, Fabrício Sousa da; Costa, Carlos Magno Amaral; Amorim, Paulo Roberto dos Santos

2014-07-01

357

Time delay between images of the lensed quasar UM673  

CERN Document Server

We study brightness variations in the double lensed quasar UM673 (Q0142-100) with the aim of measuring the time delay between its two images. In the paper we combine our previously published observational data of UM673 obtained during the 2003 - 2005 seasons at the Maidanak Observatory with archival and recently observed Maidanak and CTIO UM673 data. We analyze the V, R and I-band light curves of the A and B images of UM673, which cover ten observational seasons from August 2001 to November 2010. We also analyze the time evolution of the difference in magnitudes between images A and B of UM673 over more than ten years. We find that the quasar exhibits both short-term (with amplitude of \\sim 0.1 mag in the R band) and high-amplitude (\\sim 0.3 mag) long-term variability on timescales of about several months and several years, respectively. These brightness variations are used to constrain the time delay between the images of UM673. From cross-correlation analysis of the A and B quasar light curves and error ana...

Koptelova, E; Chiueh, T; Artamonov, B P; Oknyanskij, V L; Nuritdinov, S N; Burkhonov, O; Akhunov, T; Bruevich, V V; Ezhkova, O V; Gusev, A S; Sergeyev, A A; Ehgamberdiev, Sh A; Ibragimov, M A

2012-01-01

358

Real-time full field laser Doppler imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a full field laser Doppler imaging instrument, which enables real-time in vivo assessment of blood flow in dermal tissue and skin. This instrument monitors the blood perfusion in an area of about 50 cm² with 480 × 480 pixels per frame at a rate of 12–14 frames per second. Smaller frames can be monitored at much higher frame rates. We recorded the microcirculation in healthy skin before, during and after arterial occlusion. In initial clinical case studies, we imaged the microci...

Leutenegger, Marcel; Martin-williams, Erica; Harbi, Pascal; Thacher, Tyler; Raffoul, Wassim; Andre?, Marc; Lopez, Antonio; Lasser, Philippe; Lasser, Theo

2011-01-01

359

Real-time full field laser Doppler imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present a full field laser Doppler imaging instrument, which enables real-time in vivo assessment of blood flow in dermal tissue and skin. This instrument monitors the blood perfusion in an area of about 50 cm2 with 480 × 480 pixels per frame at a rate of 12–14 frames per second. Smaller frames can be monitored at much higher frame rates. We recorded the microcirculation in healthy skin before, during and after arterial occlusion. In initial clinical case studies, we imaged the microcir...

Leutenegger, Marcel; Martin-williams, Erica; Harbi, Pascal; Thacher, Tyler; Raffoul, Wassim; Andre?, Marc; Lopez, Antonio; Lasser, Philippe; Lasser, Theo

2011-01-01

360

Terahertz time-domain spectroscopy and imaging of artificial RNA  

DEFF Research Database (Denmark)

We use terahertz time-domain spectroscopy (THz-TDS) to measure the far-infrared dielectric function of two artificial RNA single strands, composed of polyadenylic acid (poly-A) and polycytidylic acid (poly-C). We find a significant difference in the absorption between the two types of RNA strands, and we show that we can use this difference to record images of spot arrays of the RNA strands. Under controlled conditions it is possible to use the THz image to distinguish between the two RNA strands. We discuss the requirements to sample preparation imposed by the lack of sharp spectral features in the absorption spectra.

Fischer, Bernd M.; Hoffmann, Matthias

2005-01-01

 
 
 
 
361

Real-time full field laser Doppler imaging  

Science.gov (United States)

We present a full field laser Doppler imaging instrument that enables real-time in vivo assessment of blood flow in dermal tissue and skin. The instrument monitors the blood perfusion in an area of about 50cm2 with 480 × 480 pixels per frame at a rate of 12-14 frames per second. Smaller frames can be monitored at much higher frame rates. We recorded the microcirculation in healthy skin before, during and after arterial occlusion. In initial clinical case studies, we imaged the microcirculation in burned skin and monitored the recovery of blood flow in a skin flap during reconstructive surgery indicating the high potential of LDI for clinical applications.

Leutenegger, Marcel; Harbi, Pascal; Thacher, Tyler; Raffoul, Wassim; Lasser, Theo

2012-06-01

362

A fast reconstruction algorithm for bioluminescence tomography based on smoothed l0 norm regularization  

Science.gov (United States)

As an important optical molecular imaging technique, bioluminescence tomography (BLT) offers an inexpensive and sensitive means for non-invasively imaging a variety of physiological and pathological activities at cellular and molecular levels in living small animals. The key problem of BLT is to recover the distribution of the internal bioluminescence sources from limited measurements on the surface. Considering the sparsity of the light source distribution, we directly formulate the inverse problem of BLT into an l0-norm minimization model and present a smoothed l0-norm (SL0) based reconstruction algorithm. By approximating the discontinuous l0 norm with a suitable continuous function, the SL0 norm method solves the problem of intractable computational load of the minimal l0 search as well as high sensitivity of l0-norm to noise. Numerical experiments on a mouse atlas demonstrate that the proposed SL0 norm based reconstruction method can obtain whole domain reconstruction without any a priori knowledge of the source permissible region, yielding almost the same reconstruction results to those of l1 norm methods.

He, Xiaowei; Yu, Jingjing; Geng, Guohua; Guo, Hongbo

2013-10-01

363

Chemical nature of bioluminescence systems in coelenterates.  

Science.gov (United States)

Analysis of substances involved in light-emitting reactions among bioluminescent coelenterates has revealed a pronounced uniformity in the structural features of initial reactants, i.e., "luciferins" and photo-protein chromophores, as well as the light-emitter product. This product is structurally identical among the different classes of coelenterates: Hydrozoa (the jellyfish, Aequorea), Anthozoa (the sea cactus, Cavernularia; sea pansy, Renilla; and sea pen, Leioptilus), and very likely also the Scyphozoa (the jellyfish, Pelagia). In each of these instances the reaction product, namely, 2-(p-hydroxy-pnenylacetyl)amino-3-benzyl-5-(p-hydroxyphenyl) pyrazine, is the actual light-emitter, whether it occurs in a Ca2+-triggered photoprotein type of luminescence, or in a "luciferin-luciferase" type. The evidence indicates that in certain coelenterates, e.g., Cavernularia, these two types are equally significant, whereas in others (Renilla and Leioptilus) the "luciferin-luciferase" type predominates over the Ca-triggerable photoprotein type, and finally that only the photoprotein type functions in the luciferaseless jellyfish, Aequorea. In all instances investigated, the structure of the light-emitter prior to the luminescence reaction appears to be essentially the same as that of the chromophore of unreacted aequorin. The product of the luminescence reaction is absent in extracts of non luminous species. However, a product very similar to that of luminescent coelenterates occurs also in representatives of other phyla, including the cephalopod molluscs, e.g., the "firefly squid" Watasenia and probably various ctenophores as well. PMID:236561

Shimomura, O; Johnson, F H

1975-04-01

364

In vitro energy transfer in Renilla bioluminescence  

Energy Technology Data Exchange (ETDEWEB)

A quantitative study of in vitro energy transfer in a natural biological system is reported. The in vitro bioluminescent oxidation of Renilla (sea pansy) luciferin by luciferase produces a broad, structureless emission, peaking in the blue at 490 nm. In contrast, the live animal produces a structured emission peaking in the green at 509 nm. This difference in emission characteristics is due to the presence, in Renilla, of a green fluorescent protein (GFP). Addition of GFP in vitro sensitizes the oxyluciferin product excited state, resulting in the narrow, structured green emission characteristic of GFP fluorescence (lambda/sub max/ 509 nm). Under conditions of efficient in vitro energy transfer (2.7 x 10/sup -6/ M GFP) the radiative quantum yield (with respect to luciferin) increases 5.7-fold from 5.3% (blue pathway) to 30% (green pathway). The fluorescence quantum yield of the Renilla GFP has been measured as 30%; thus, within the precision of our measurements (15% coefficient of variation) the in vitro energy transfer efficiency is a surprising 100%.

Ward, W.W.; Cormier, M.J.

1976-09-23

365

Time-resolved tomographic images of a relativistic electron beam  

International Nuclear Information System (INIS)

We obtained a sequential series of time-resolved tomographic two-dimensional images of a 4.5-MeV, 6-kA, 30-ns electron beam. Three linear fiber-optic arrays of 30 or 60 fibers each were positioned around the beam axis at 00, 610, and 1170. The beam interacting with nitrogen at 20 Torr emitted light that was focused onto the fiber arrays and transmitted to a streak camera where the data were recorded on film. The film was digitized, and two-dimensional images were reconstructed using the maximum-entropy tomographic technique. These images were then combined to produce an ultra-high-speed movie of the electron-beam pulse

366

Real-time full field laser Doppler imaging  

Science.gov (United States)

We present a full field laser Doppler imaging instrument, which enables real-time in vivo assessment of blood flow in dermal tissue and skin. This instrument monitors the blood perfusion in an area of about 50 cm2 with 480 × 480 pixels per frame at a rate of 12–14 frames per second. Smaller frames can be monitored at much higher frame rates. We recorded the microcirculation in healthy skin before, during and after arterial occlusion. In initial clinical case studies, we imaged the microcirculation in burned skin and monitored the recovery of blood flow in a skin flap during reconstructive surgery indicating the high potential of LDI for clinical applications. Small animal imaging in mouse ears clearly revealed the network of blood vessels and the corresponding blood perfusion. PMID:21698011

Leutenegger, Marcel; Martin-Williams, Erica; Harbi, Pascal; Thacher, Tyler; Raffoul, Wassim; André, Marc; Lopez, Antonio; Lasser, Philippe; Lasser, Theo

2011-01-01

367

Real-time digital X-ray subtraction imaging  

International Nuclear Information System (INIS)

A diagnostic anatomical X-ray apparatus comprising a converter and a television camera for converting an X-ray image of a subject into a series of television fields of video signals is described in detail. A digital memory system stores and integrates the video signals over a time interval corresponding to a plurality of successive television fields. The integrated video signals are recovered from storage and fed to a digital or analogue subtractor, the resulting output being displayed on a television monitor. Thus the display represents on-going changes in the anatomical X-ray image. In a modification, successive groups of fields are stored and integrated in three memories, cyclically, and subtractions are performed between successive pieces of integrated signals to provide a display of successive alterations in the X-ray image. For investigations of the heart, the integrating interval should be of the order of one cardiac cycle. (author)

368

Near real-time disturbance detection using satellite image time series  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Near real-time monitoring of ecosystem disturbances is critical for rapidly assessing and addressing impacts on carbon dynamics, biodiversity, and socio-ecological processes. Satellite remote sensing enables cost-effective and accurate monitoring at frequent time steps over large areas. Yet, generic methods to detect disturbances within newly captured satellite images are lacking. We propose a multi-purpose time-series-based disturbance detection approach that identifies and models stable his...

Verbesselt, J. P.; Zeileis, A.; Herold, M.

2012-01-01

369

Time-of-flight imaging of invisibility cloaks  

CERN Document Server

As invisibility cloaking has recently become experimental reality, it is interesting to explore ways to reveal remaining imperfections. In essence, the idea of most invisibility cloaks is to recover the optical path lengths without an object (to be made invisible) by a suitable arrangement around that object. Optical path length is proportional to the time of flight of a light ray or to the optical phase accumulated by a light wave. Thus, time-of-flight images provide a direct and intuitive tool for probing imperfections. Indeed, recent phase-sensitive experiments on the carpet cloak have already made early steps in this direction. In the macroscopic world, time-of-flight images could be measured directly by light detection and ranging (LIDAR). Here, we show calculated time-of-flight images of the conformal Gaussian carpet cloak, the conformal grating cloak, the cylindrical free-space cloak, and of the invisible sphere. All results are obtained by using a ray-velocity equation of motion derived from Fermat's ...

Halimeh, Jad C

2011-01-01

370

Near-Real-Time 3D Ultrasonic Strain Imaging  

Science.gov (United States)

This paper describes a near-real-time system for acquiring and displaying 3D ultrasonic strain images using a mechanical sector transducer. For improved image quality and robustness, all signal processing is fully 3D, including 3D data windows, 3D least-squares fitting for the displacement-to-strain calculation, 3D strain normalization and full displacement tracking in the axial, lateral and elevational directions. Notwithstanding this thorough signal processing, 3D strain volumes are typically available for inspection within 20 seconds of performing the scan, with no need for special hardware. The speed is achieved by iterative phase-zero displacement tracking in the axial direction and novel methods for tracking in the lateral and elevational directions. Since the displacement tracking does not rely on the common (but brittle) zero-displacement assumption at the transducer face, high quality strain images are obtained reliably. The paper includes examples of in vitro strain images with full details of the acquisition and processing times.

Treece, G.; Lindop, J.; Gee, A.; Prager, R.

371

Timing and position response of a block detector for fast neutron time-of-flight imaging  

Science.gov (United States)

Our research effort seeks to improve the spatial and timing performance of a block detector made of a pixilated plastic scintillator (EJ-200), first demonstrated as part of Oak Ridge National Laboratory's Advanced Portable Neutron Imaging System. Improvement of the position and time response is necessary to achieve better resolution and contrast in the images of shielded special nuclear material. Time-of-flight is used to differentiate between gamma and different sources of neutrons (e.g., transmission and fission neutrons). Factors limiting the timing and position performance of the neutron detector have been revealed through simulations and measurements. Simulations have suggested that the degradation in the ability to resolve pixels in the neutron detector is due to those interactions occurring near the light guide. The energy deposition within the neutron detector is shown to affect position performance and imaging efficiency. This examination details how energy cuts improve the position performance and degrade the imaging efficiency. Measurements have shown the neutron detector to have a timing resolution of ?=238 ps. The majority of this timing uncertainty is from the depth-of-interaction (DOI) of the neutron which is confirmed by simulations and analytical calculations.

Laubach, M. A.; Hayward, J. P.; Zhang, X.; Cates, J. W.

2014-11-01

372

Imaging nuclear decays with Optical Time Projection Chamber  

Science.gov (United States)

A novel type of gaseous ionization detector—Optical Time Projection Chamber (OTPC)—developed to study rare nuclear decays is presented. The OTPC records tracks of charged particles ionizing a counting gas by optical imaging of the light generated by electrons multiplied in the amplification structures. By combining an electron drift-time profile measured by a photomultiplier and a CCD camera image we reconstruct three-dimensional trajectories of particles, energies and charges. The capabilities of the OTPC detector to study various decay modes are demonstrated by observation of beta-delayed proton emission from 13O, two-alpha break-up of 8Be, triple-alpha decay of 12C excited states and two-proton radioactivity of 45Fe.

Miernik, K.; Dominik, W.; Janas, Z.; Pfützner, M.; Bingham, C.; Czyrkowski, H.; ?wiok, M.; Darby, I.; D?browski, R.; Fomitchev, A.; Gintei, T.; Golovkov, M.; Grzywacz, R.; Karny, M.; Korgul, A.; Ku?mierz, W.; Liddick, S.; Rajabali, M.; Rodin, A.; Rykaczewski, K.; Stepantsov, S.; Slepniev, R.; Stolz, A.; Ter-Akopian, G. M.; Wolski, R.

2007-11-01

373

Bioluminescence and Deep Sea Life: All That Glitters... (title provided or enhanced by cataloger)  

Science.gov (United States)

In this lesson, students will investigate absorption, reflection, and scattering of light in the deep sea and discover the concept of bioluminescence. As they proceed, they will learn that white light (visible light) is comprised of all colors of the spectrum, that the quantity of light decreases with increasing depth in the ocean, the quality of light changes with increasing depth, and that red light penetrates water the least and that blue light penetrates water the most. They will also learn that many ocean organisms are bioluminescent, why organisms bioluminesce, and that bioluminescent light is usually blue. In addition, students will learn about several bioluminescent animals through independent research.

374

Imaging crystallographic phases using time-of-flight neutron diffraction  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Identification and imaging of crystallographic phases inside an object can be achieved by time-of-flight neutron diffraction, based on a correction formula that is usually used to account for a sample offset on a powder diffractometer. The procedure allows the distribution of crystallographic phases along the incident beam path through the thickness of the material to be reconstructed. Phase reconstruction is demonstrated on a benchmark object. © 2006 Elsevier B.V. All rights reserved.

Gutmann, M.; Kockelmann, W.; Chapon, L.; Radaelli, Pg

2006-01-01

375

Real-Time Analysis of Large Astronomical Images  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Forthcoming instruments designed for high-cadence large-area surveys, such as the Dark Energy Survey and Large Synoptic Survey Telescope, will generate several GB of data products every few minutes during survey operations. Since such surveys are designed to operate with minimal observer interaction, automated real-time analysis of these large images is necessary to ensure uninterrupted production of science-quality data. We describe a software infrastructure suite designed ...

Kuehn, K.; Hupe, R.

2012-01-01

376

Stain effects studied by time-resolved infrared imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pattern formation in evaporating colloidal droplets is an important phenomenon that is commonly observed in several solute?solvent systems; this is also an emerging technique for obtaining fine patterning through controlled conditions of drying. After evaporation of the solvent a ring-like pattern remains on the solid substrate under the condition of contact line pinning. We have used a new analytical technique, time-resolved infrared imaging, to investigate the formation of patterned struc...

Innocenzi, Plinio; Malfatti, Luca; Piccinini, Massimo; Grosso, David; Marcelli, Augusto Claudio

2009-01-01

377

Aequorea victoria bioluminescence moves into an exciting new era.  

Science.gov (United States)

Bioluminescence has revolutionized research into many cellular and molecular-biological processes, ranging from intracellular signalling to gene transcription. This article focuses on the chemistry and biotechnological exploitation of the two proteins involved in bioluminescence of the jellyfish Aequorea victoria--aequorin and green fluorescent protein. Engineered recombinant aequorin has led to a novel technological approach to monitoring calcium signals in organelles and subcellular domains. A new generation of intracellular calcium indicators has been produced in which engineered variants of green fluorescent protein are used to probe their ionic environment using intramolecular fluorescence-resonance-energy transfer. PMID:9621461

Kendall, J M; Badminton, M N

1998-05-01

378

Imaging gene expression in real-time using aptamers  

Energy Technology Data Exchange (ETDEWEB)

Signal transduction pathways are usually activated by external stimuli and are transient. The downstream changes such as transcription of the activated genes are also transient. Real-time detection of promoter activity is useful for understanding changes in gene expression, especially during cell differentiation and in development. A simple and reliable method for viewing gene expression in real time is not yet available. Reporter proteins such as fluorescent proteins and luciferase allow for non-invasive detection of the products of gene expression in living cells. However, current reporter systems do not provide for real-time imaging of promoter activity in living cells. This is because of the long time period after transcription required for fluorescent protein synthesis and maturation. We have developed an RNA reporter system for imaging in real-time to detect changes in promoter activity as they occur. The RNA reporter uses strings of RNA aptamers that constitute IMAGEtags (Intracellular MultiAptamer GEnetic tags), which can be expressed from a promoter of choice. The tobramycin, neomycin and PDC RNA aptamers have been utilized for this system and expressed in yeast from the GAL1 promoter. The IMAGEtag RNA kinetics were quantified by RT-qPCR. In yeast precultured in raffinose containing media the GAL1 promoter responded faster than in yeast precultured in glucose containing media. IMAGEtag RNA has relatively short half-life (5.5 min) in yeast. For imaging, the yeast cells are incubated with their ligands that are labeled with fluorescent dyes. To increase signal to noise, ligands have been separately conjugated with the FRET (Förster resonance energy transfer) pairs, Cy3 and Cy5. With these constructs, the transcribed aptamers can be imaged after activation of the promoter by galactose. FRET was confirmed with three different approaches, which were sensitized emission, acceptor photobleaching and donor lifetime by FLIM (fluorescence lifetime imaging microscopy). Real-time transcription was measured by FLIM-FRET, which was detected by the decrease in donor lifetime resulting from ligand binding to IMAGEtags that were newly synthesized from the activated GAL1 promoter. The FRET signal was specific for transcribed IMAGEtags.

Shin, Il Chung [Ames Laboratory

2012-11-02

379

Time-delayed fluorescence imaging of a porphycene derivative  

Science.gov (United States)

Porphycenes are currently under investigation for use in Photodynamic therapy, which is a promising treatment for cancer. These materials, which display preferential uptake in cancerous cells, also exhibit high fluorescence yields, and can be used for tumour detection. Problems with steady-state fluorescence techniques such as background autofluorescence can be eliminated by the use of time-resolved techniques. Improved contrast can be obtained with time-resolved techniques because of the differing fluorescence lifetimes between autofluorescence and longer-living exogenous photosensitisers. An imaging system was constructed using a fast (200 ps) gated CCD camera and a pulsed 635 nm laser diode. A tissue phantom composed of polymethyl methacrylate (PMMA) with thirty-six wells of varying diameter and depth (10 mm to 1 mm) was assembled to test the system. The system was used to record images of a porphycene derivative within the wells at differing concentrations in an organic solvent. A tissue imitator was placed on top of the PMMA block at varying thickness. 10-4 M zinc phthalocyanine tetrasulfonate was also placed on top of the block to mimic autofluorescence. The results indicate that the time-gated imaging system can prevent background excitation scatter and fluorescence from a shorter-lived fluorophore from distorting the fluorescence signal from a longer-lived photosensitiser.

Gundy, Sarah L.; van der Putten, Wilhelm J.; Shearer, Andrew; Buckton, Daniel J.; Ryder, Alan G.; Ball, Michael

2003-06-01

380

Partial scene reconstruction using Time-of-Flight imaging  

Science.gov (United States)

This paper is devoted to generating the coordinates of partial 3D points in scene reconstruction via time of flight (ToF) images. Assuming the camera does not move, only the coordinates of the points in images are accessible. The exposure time is two trillionths of a second and the synthetic visualization shows that the light moves at half a trillion frames per second. In global light transport, direct components signify that the light is emitted from a light point and reflected from a scene point only once. Considering that the camera and source light point are supposed to be two focuses of an ellipsoid and have a constant distance at a time, we take into account both the constraints: (1) the distance is the sum of distances which light travels between the two focuses and the scene point; and (2) the focus of the camera, the scene point and the corresponding image point are in a line. It is worth mentioning that calibration is necessary to obtain the coordinates of the light point. The calibration can be done in the next two steps: (1) choose a scene that contains some pairs of points in the same depth, of which positions are known; and (2) take the positions into the last two constraints and get the coordinates of the light point. After calculating the coordinates of scene points, MeshLab is used to build the partial scene model. The proposed approach is favorable to estimate the exact distance between two scene points.

Zhang, Yuchen; Xiong, Hongkai

2014-11-01

 
 
 
 
381

Optical Time Projection Chamber for imaging nuclear decays  

International Nuclear Information System (INIS)

We present a novel type of a Time Projection Chamber in which tracks of charged particles ionizing an active gas volume are recorded by means of optical signals. By combining a CCD camera image with the electron drift-time profile measured by a photomultiplier, it is possible to reconstruct trajectories of particles in three dimensions. The chamber was developed to study exotic nuclear decays in which charged particles are emitted. The results of first measurements will be demonstrated in which beta-delayed protons from 13O, the two-alpha decay of 8Be, and the triple-alpha decay of 12C excited states were recorded

382

Hardware implementation of image segmentation algorithm for real-time image compression  

Science.gov (United States)

Segmentation algorithms are fast and simple technique used to obtain an image representation at different resolution levels, so they are widely used for image compression. Neither floating-point calculations nor large amounts of memory is required, so these algorithms can be easily implemented in relatively cheap and simple real-time systems. The proposed algorithm divides an image into rectangular blocks, which may overlap. The width and height of these blocks are set independently and can have optimal values from a preset range. Blocks are filled with a mean value of pixels from original image and their sizes are increased until the mean square error value for the block is smaller than the preset value. Next, the hardware implementation in single FPGA device is proposed. Paper also presents results obtained during off-line image compression. These results show better quality (in PSNR ratio) of restored images in compare to standard QuadTree algorithm. Simulations show that proposed hardware architecture can process standard monochrome CIF image with speed over 30 frames per second preserving low cost and high quality.

Wasilewski, Piotr

1998-10-01

383

Real-time FPGA Based Implementation of Color Image Edge Detection  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Color Image edge detection is very basic and important step for many applications such as image segmentation, image analysis, facial analysis, objects identifications/tracking and many others. The main challenge for real-time implementation of color image edge detection is because of high volume of data to be processed (3 times as compared to gray images). This paper describes the real-time implementation of Sobel operator based color image edge detection using FPGA. Sobel operator is chosen ...

Sanjay Singh; Anil Kumar Saini; Ravi Saini

2012-01-01

384

Time delay between images of the lensed quasar UM673  

Science.gov (United States)

Aims: We study brightness variations in the double lensed quasar UM673 (Q0142-100) with the aim of measuring the time delay between its two images. Methods: We combined our previously published observational data of UM673 obtained during the 2003-2005 seasons at the Maidanak Observatory with archival and recently observed Maidanak and CTIO UM673 data. We analyzed the V, R and I-band light curves of the A and B images of UM673, which cover ten observational seasons from August 2001 to November 2010. We also analyzed the time evolution of the difference in magnitudes (flux ratio) between images A and B of UM673 over more than ten years. Results: We find that the quasar exhibits both short-term (with an amplitude of ~0.1 mag in the R band) and long-term (with an amplitude of ~0.3 mag) variability on timescales of about several months and several years, respectively. These brightness variations are used to constrain the time delay between the images of UM673. From a cross-correlation analysis of the A and B quasar light curves and an error analysis we measure a mean time delay of 89 days with an rms error of 11 days. Given the input time delay of 88 days, the most probable value of the delay that can be recovered from light curves with the same statistical properties as the observed R-band light curves of UM673, is 95-16+5-29+14 days (68% and 95% confidence intervals). Analysis of the V - I color variations and the V, R and I-band magnitude differences of the quasar images does not show clear evidence for microlensing variations between 1998 and 2010. Figures 2 and 3 are available in electronic form at http://www.aanda.orgPhotometry is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/544/A51

Koptelova, E.; Chen, W. P.; Chiueh, T.; Artamonov, B. P.; Oknyanskij, V. L.; Nuritdinov, S. N.; Burkhonov, O.; Akhunov, T.; Bruevich, V. V.; Ezhkova, O. V.; Gusev, A. S.; Sergeyev, A. V.; Ehgamberdiev, Sh. A.; Ibragimov, M. A.

2012-08-01

385

Stain effects studied by time-resolved infrared imaging.  

Science.gov (United States)

Pattern formation in evaporating colloidal droplets is an important phenomenon that is commonly observed in several solute-solvent systems; this is also an emerging technique for obtaining fine patterning through controlled conditions of drying. After evaporation of the solvent a ring-like pattern remains on the solid substrate under the condition of contact line pinning. We have used a new analytical technique, time-resolved infrared imaging, to investigate the formation of patterned structures with droplet drying, which is a typical time-dependent phenomenon. We have coupled the technique with optical imaging to follow the evolution of the droplet shape and dimension in correspondence with the chemical images. The main advantage of the technique is represented by the possibility to have simultaneous spatial and time-resolved information; we have applied the method to a water-methylene blue system that has been studied during drying. We have monitored the droplet profile change, in terms of water and methylene blue variation with time and space, at the droplet edge. The analysis has allowed a detailed reconstruction of the evaporating droplet profile with a micrometer scale resolution and of the change in concentration of the dye as a function of evaporating time. A uniform ring-like pattern, after evaporation in controlled relative humidity, is observed. The data are consistent with a constant evaporation model, whose conditions are realized when a constant evaporation is achieved along the entire droplet. The technique has allowed elucidating the evaporation phenomenon close to the contact line in a dye solute-solvent system, which is very difficult to study with other techniques. PMID:19072663

Innocenzi, Plinio; Malfatti, Luca; Piccinini, Massimo; Grosso, David; Marcelli, Augusto

2009-01-15

386

Real-time holographic video images with commodity PC hardware  

Science.gov (United States)

The MIT second-generation holographic video system is a real-time electro-holographic display. The system produces a single-color horizontal parallax only (HPO) holographic image. To reconstruct a three-dimensional image, the display uses a computed fringe pattern with an effective resolution of 256K samples wide by 144 lines high by 8 bits per sample. In this paper we first describe the implementation of a new computational subsystem for the display, replacing custom computing hardware with commodity PC graphics chips, and using OpenGL. We also report the implementation of stereogram computing techniques that employ the PC hardware acceleration to generate and update holographic images at rates of up to two frames per second. These innovations shrink the system"s physical footprint to fit on the table-top and mark the fastest rate at which full computation and update have been achieved on this system to date. Finally we present first results of implementing the Reconfigurable Image Projection (RIP) method of computing high-quality holograms on this new system.

Bove, V. Michael, Jr.; Plesniak, Wendy J.; Quentmeyer, Tyeler; Barabas, James

2005-03-01

387

Real-time exploitation of image sequences in dynamic surroundings  

Science.gov (United States)

Technological progress in the fields of computing hardware and efficient algorithms make it possible to set up real-time exploitation systems for a huge number of applications (e.g. assessment of camouflage effectiveness, or various surveil-lance applications, UAVs, as well as image sequence data reduction, indexing, archiving, and retrieval). The system in question has been developed to cope with highly dynamic situations. Such dynamic situations may be characterized by moving targets acquired by a static, trembling, or moving sensor system. The image sequences may stem from a visual-optical (VIS) or some forward looking infrared (FLIR) sensor. Except for wide-angle lenses (due to their optical distortions) neither sensor nor calibration parameters have to be known to the automatic exploitation system. Furthermore no human interaction is required. The algorithmic approach tries to digitally stabilize the movement of the sensor system. To accomplish this task the algorithm extracts 40-60 tie points from the static nonmoving background, then robustly matches the tie point constellations frame to frame for calculating the 8 parameters of a projective mapping. This is the basis for some sort of background stabilization. The difference image of two consecutive and matched image frames re-veals the moving targets. After the segmentation of the (moving) target signatures, additionally attached tracking and classification components have been tested.

Mueller, Markus; Saur, Guenter; Krueger, Wolfgang

2005-05-01

388

Real-time implementation of superresolution imaging algorithm  

Science.gov (United States)

The design and implementation of a real-time super-resolution imaging processor was conducted as a benchmark for the Rapid Prototyping of Application Specific Signal Processors (RASSP) program. RASSP is a DARPA/Tri-services sponsored program aimed at accelerating the design process for digital electronic systems. The super-resolution subsystem is part of a Semi-Automated Image-intelligence Processing (SAIP) system. The benchmark project required a reduction in the size and increase in performance of the prototype system, which had been implemented on an array of workstations. The RASSP methodology was applied to guide the design process and RASSP-related analysis tools were used to accelerate the software development. The numerical and run-time performance goals were achieved through a combination of software innovations in the imaging algorithm and porting to a high-density commercial off-the-shelf high-performance parallel processor. The selected processor consisted of four Alex Computer boards containing a total of 72 ADSP-21060 signal processors.

Hein, Carl E.

1998-10-01

389

Real-time Image Generation for Compressive Light Field Displays  

International Nuclear Information System (INIS)

With the invention of integral imaging and parallax barriers in the beginning of the 20th century, glasses-free 3D displays have become feasible. Only today—more than a century later—glasses-free 3D displays are finally emerging in the consumer market. The technologies being employed in current-generation devices, however, are fundamentally the same as what was invented 100 years ago. With rapid advances in optical fabrication, digital processing power, and computational perception, a new generation of display technology is emerging: compressive displays exploring the co-design of optical elements and computational processing while taking particular characteristics of the human visual system into account. In this paper, we discuss real-time implementation strategies for emerging compressive light field displays. We consider displays composed of multiple stacked layers of light-attenuating or polarization-rotating layers, such as LCDs. The involved image generation requires iterative tomographic image synthesis. We demonstrate that, for the case of light field display, computed tomographic light field synthesis maps well to operations included in the standard graphics pipeline, facilitating efficient GPU-based implementations with real-time framerates.

390

High-temperature real-time ultrasonic imaging  

International Nuclear Information System (INIS)

Ultrasonic instrumentation capable of real-time imaging of materials at temperatures up to 2880C (5900F) is described. The research and development of this unique instrumentation was sponsored by the Electric Power Research Institute of Palo Alto, California, for use in nuclear power plants. The instrumentation developed will permit continuous surveillance of piping while the power plant is in operation. The instrumentation utilizes a combination of high-temperature materials to fabricate a unique piezoelectric transmitter and a high-temperature electromagnetic acoustic transducer (EMAT). The high-temperature EMAT operates at 2.5 MHz, which is well above preceding models of about 800 kHz. Use of unique high-temperature materials to permit scanning of material volume is combined with an imaging system to allow time-lapse image information. This paper traces the theory and describes material properties of interest and reports on test results for a development system that has been in continuous operation on a field test site for two years. Future applications and development plans are outlined

391

Real time blood testing using quantitative phase imaging.  

Science.gov (United States)

We demonstrate a real-time blood testing system that can provide remote diagnosis with minimal human intervention in economically challenged areas. Our instrument combines novel advances in label-free optical imaging with parallel computing. Specifically, we use quantitative phase imaging for extracting red blood cell morphology with nanoscale sensitivity and NVIDIA's CUDA programming language to perform real time cellular-level analysis. While the blood smear is translated through focus, our system is able to segment and analyze all the cells in the one megapixel field of view, at a rate of 40 frames/s. The variety of diagnostic parameters measured from each cell (e.g., surface area, sphericity, and minimum cylindrical diameter) are currently not available with current state of the art clinical instruments. In addition, we show that our instrument correctly recovers the red blood cell volume distribution, as evidenced by the excellent agreement with the cell counter results obtained on normal patients and those with microcytic and macrocytic anemia. The final data outputted by our instrument represent arrays of numbers associated with these morphological parameters and not images. Thus, the memory necessary to store these data is of the order of kilobytes, which allows for their remote transmission via, for example, the cellular network. We envision that such a system will dramatically increase access for blood testing and furthermore, may pave the way to digital hematology. PMID:23405194

Pham, Hoa V; Bhaduri, Basanta; Tangella, Krishnarao; Best-Popescu, Catherine; Popescu, Gabriel

2013-01-01

392

Detection of heterogeneous substrate distributions in tumors and spheroids by bioluminescence  

International Nuclear Information System (INIS)

Heterogeneous cell populations within solid tumors often limit non-surgical tumor therapies