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1

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

2010-01-01

2

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

3

Bioluminescent imaging of bacteria during mouse infection.  

UK PubMed Central (United Kingdom)

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.

Warawa JM; Lawrenz MB

2014-01-01

4

Real-time bioluminescence imaging of macroencapsulated fibroblasts reveals allograft protection in rhesus monkeys (Macaca mulatta).  

UK PubMed Central (United Kingdom)

BACKGROUND: Encapsulation of cells has the potential to eliminate the need for immunosuppression for cellular transplantation. Recently, the TheraCyte device was shown to provide long-term immunoprotection of murine islets in a mouse model of diabetes. In this report, translational studies were undertaken using skin fibroblasts from an unrelated rhesus monkey donor that were transduced with an HIV-1-derived lentiviral vector expressing firefly luciferase permitting the use of bioluminescence imaging (BLI) to monitor cell survival over time and in a noninvasive manner. METHODS: Encapsulated cells were transplanted subcutaneously (n=2), or cells were injected without encapsulation (n=1) and outcomes compared. BLI was performed to monitor cell survival. RESULTS: The BLI signal from the encapsulated cells remained robust postinsertion and in one animal persisted for up to 1 year. In contrast, the control animal that received unencapsulated cells exhibited a complete loss of cell signal within 14 days. CONCLUSIONS: These data demonstrate that TheraCyte encapsulation of allogeneic cells provides robust immune protection in transplanted rhesus monkeys.

Tarantal AF; Lee CC; Itkin-Ansari P

2009-07-01

5

Digital spectral separation methods and systems for bioluminescence imaging.  

UK PubMed Central (United Kingdom)

We propose a digital spectral separation (DSS) system and methods to extract spectral information optimally from a weak multi-spectral signal such as in the bioluminescent imaging (BLI) studies. This system utilizes our newly invented spatially-translated spectral-image mixer (SSM), which consists of dichroic beam splitters, a mirror, and a DSS algorithm. The DSS approach overcomes the shortcomings of the data acquisition scheme used for the current BLI systems. Primarily, using our DSS scheme, spectral information will not be filtered out. Accordingly, truly parallel multi-spectral multi-view acquisition is enabled for the first time to minimize experimental time and optimize data quality. This approach also permits recovery of the bioluminescent signal time course, which is useful to study the kinetics of multiple bioluminescent probes using multi-spectral bioluminescence tomography (MSBT).

Wang G; Shen H; Liu Y; Cong A; Cong W; Wang Y; Dubey P

2008-02-01

6

Digital spectral separation methods and systems for bioluminescence imaging.  

Science.gov (United States)

We propose a digital spectral separation (DSS) system and methods to extract spectral information optimally from a weak multi-spectral signal such as in the bioluminescent imaging (BLI) studies. This system utilizes our newly invented spatially-translated spectral-image mixer (SSM), which consists of dichroic beam splitters, a mirror, and a DSS algorithm. The DSS approach overcomes the shortcomings of the data acquisition scheme used for the current BLI systems. Primarily, using our DSS scheme, spectral information will not be filtered out. Accordingly, truly parallel multi-spectral multi-view acquisition is enabled for the first time to minimize experimental time and optimize data quality. This approach also permits recovery of the bioluminescent signal time course, which is useful to study the kinetics of multiple bioluminescent probes using multi-spectral bioluminescence tomography (MSBT). PMID:18542251

Wang, Ge; Shen, Haiou; Liu, Ying; Cong, Alex; Cong, Wenxiang; Wang, Yue; Dubey, Purnima

2008-02-01

7

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; Castro Daniele P; Gomes Leonardo HF; Garcia Eloi S; de Souza Wanderley

2012-01-01

8

Bioluminescent imaging of pneumococcal otitis media in chinchillas.  

UK PubMed Central (United Kingdom)

OBJECTIVES: Bioluminescent imaging has emerged as a powerful tool for monitoring the pathological process of infections in animals. The purpose of this study was to harness this new tool for objective assessment of acute otitis media (AOM) in animals with and without antibiotic interventions. METHODS: Thirty-six healthy chinchillas, free of middle ear infections, were randomly divided into a control group and a group that received amoxicillin treatment. Bioluminescent Streptococcus pneumoniae (Xen 10) was injected into the epitympanic bullae of chinchillas (50 colony-forming units each) for induction of AOM. The infectious process of Xen 10 in the bullae of living animals with and without antibiotic interventions was monitored in real time with bioluminescence equipment. RESULTS: A dynamic change of bioluminescent signals in the bullae of chinchillas from days 1 to 14 was observed after Xen 10 injection. Amoxicillin treatment reduced the bioluminescent signals in the bullae of chinchillas compared with controls. The AOM persisted for 14 days, and middle ear effusion for 6 weeks, in the control animals, whereas AOM lasted for 2 days, and effusion for 6 to 12 days, in the antibiotic-treated animals. CONCLUSIONS: Bioluminescent imaging provides an innovative method for assessment of the bacterial loads in the middle ear of chinchillas in a real-time manner and is very useful for objective evaluation of the efficacy of therapeutic interventions.

Johnson AW; Sidman JD; Lin J

2013-05-01

9

Continuous delivery of D-luciferin by implanted micro-osmotic pumps enables true real-time bioluminescence imaging of luciferase activity in vivo.  

UK PubMed Central (United Kingdom)

Bioluminescence imaging (BLI) of luciferase reporters in small animal models offers an attractive approach to monitor regulation of gene expression, signal transduction, and protein-protein interactions, as well as following tumor progression, cell engraftment, infectious pathogens, and target-specific drug action. Conventional BLI can be repeated within the same animal after bolus reinjections of a bioluminescent substrate. However, intervals between image acquisitions are governed by substrate pharmacokinetics and excretion, therefore restricting temporal resolution of reinjection protocols to the order of hours, limiting analyses of processes in vivo with short time constants. To eliminate these constraints, we examined use of implanted micro-osmotic pumps for continuous, long-term delivery of bioluminescent substrates. Pump-assisted d-luciferin delivery enabled BLI for > or = 7 days from a variety of luciferase reporters. Pumps allowed direct repetitive imaging at < 5-minute intervals of the pharmacodynamics of proteasome- and IKK-inhibiting drugs in mice bearing tumors stably expressing ubiquitin-firefly luciferase or IkappaBalpha-firefly luciferase fusion reporters. Circadian oscillations in the olfactory bulbs of transgenic rats expressing firefly luciferase under the control of the period1 promoter also were temporally resolved over the course of several days. We conclude that implanted pumps provide reliable, prolonged substrate delivery for high temporal resolution BLI, traversing complications of repetitive substrate injections.

Gross S; Abraham U; Prior JL; Herzog ED; Piwnica-Worms D

2007-03-01

10

Quantitative analysis of Plasmodium berghei liver stages by bioluminescence imaging.  

UK PubMed Central (United Kingdom)

We describe simple and sensitive in vitro and in vivo assays to analyze Plasmodium liver stage development using transgenic P. berghei parasites (PbGFP-Luccon), which express the bioluminescent reporter protein, luciferase. In these assays, parasite development in hepatocytes is visualized and quantified by real-time bioluminescence imaging both in culture and in live mice. We also describe quantification of in vitro liver-stage development by measuring luminescence using a microplate reader. Reporter-parasite based quantification of liver-stage development is faster and correlates very well with established quantitative RT-PCR methods currently used to assess parasite development inside hepatocytes, both in live mice and in culture.

Annoura T; Chevalley S; Janse CJ; Franke-Fayard B; Khan SM

2013-01-01

11

Bioluminescence imaging of P. berghei Schizont sequestration in rodents.  

Science.gov (United States)

We describe a technology for imaging the sequestration of infected red blood cells (iRBC) of the rodent malaria parasite Plasmodium berghei both in the bodies of live mice and in dissected organs, using a transgenic parasite that expresses luciferase. Real-time imaging of sequestered iRBC is performed by measuring bioluminescence produced by the enzymatic reaction in parasites between the luciferase enzyme and its substrate luciferin injected into the mice several minutes prior to imaging. The bioluminescence signal is detected by a sensitive I-CCD photon-counting video camera. Using a reporter parasite that expresses luciferase under the control of a schizont-specific promoter (i.e., the ama-1 promoter), the schizont stage is made visible when detecting bioluminescence signals. Schizont sequestration is imaged during short-term infections with parasites that are synchronized in development or during ongoing infections. Real-time in vivo imaging of iRBC will provide increased insights into the dynamics of sequestration and its role in pathology, and can be used to evaluate strategies that prevent sequestration. PMID:22990791

Braks, Joanna; Aime, Elena; Spaccapelo, Roberta; Klop, Onny; Janse, Chris J; Franke-Fayard, Blandine

2013-01-01

12

Bioluminescence imaging: basics and practical limitations.  

UK PubMed Central (United Kingdom)

Over the last three decades, imaging has been a thriving field with continuous egression of more reliable and highly sophisticated tools and techniques allowing better understanding of biological processes in living organisms. This field continues to expand and its applications broaden to encompass limitless applications in various biomedical research areas. It is however, of utmost importance to understand the capabilities and limitations of this technique as new challenges and hurdles continue to arise. This chapter describes the general properties of bioluminescence imaging and commonly used reporters while underlining the challenges and limitations with these modalities.

Badr CE

2014-01-01

13

ApoG2 induces ER stress-dependent apoptosis in gastric cancer cells in vitro and its real-time evaluation by bioluminescence imaging in vivo.  

UK PubMed Central (United Kingdom)

Apogossypolone (ApoG2), a potent small molecular inhibitor of Bcl-2 family proteins, is reported to have a significant anti-cancer effect in several types of cancers, but it has not been investigated in gastric cancer. In this study, we demonstrate in vitro and in vivo that ApoG2 inhibits human gastric cancer. Gastric carcinoma cell growth and proliferation was significantly hampered in vitro, as measured by MTT and colony formation assays. Real-time bioluminescence imaging indicated that ApoG2 causes tumor growth delay in a murine xenograft model. Further studies revealed that the ApoG2 induced apoptosis in gastric cancer cells was associated with the endoplasmic reticulum stress-induced apoptosis pathway. Conclusively, our results indicate that ApoG2 may be a promising agent for gastric cancer therapy.

Xin J; Zhan Y; Liu M; Hu H; Xia L; Nie Y; Wu K; Liang J; Tian J

2013-08-01

14

Longitudinal Bioluminescence Imaging of the Dynamics of Doxorubicin Induced Apoptosis  

Science.gov (United States)

Objectives: Most chemotherapy agents cause tumor cell death primarily by the induction of apoptosis. The ability to noninvasively image apoptosis in vivo could dramatically benefit pre-clinical and clinical evaluation of chemotherapeutics targeting the apoptotic pathway. This study aims to visualize the dynamics of apoptotic process with temporal bioluminescence imaging (BLI) using an apoptosis specific bioluminescence reporter gene. Methods: Both UM-SCC-22B human head and neck squamous carcinoma cells and 4T1 murine breast cancer cells were genetically modified with a caspase-3 specific cyclic firefly luciferase reporter gene (pcFluc-DEVD). Apoptosis induced by different concentrations of doxorubicin in the transfected cells was evaluated by both annexin V staining and BLI. Longitudinal BLI was performed in xenografted tumor models at different time points after doxorubicin or Doxil treatment, to evaluate apoptosis. After imaging, DNA fragmentation in apoptotic cells was assessed in frozen tumor sections using TUNEL staining. Results: Dose- and time-dependent apoptosis induced by doxorubicin in pcFluc-DEVD transfected UM-SCC-22B and 4T1 cells was visualized and quantified by BLI. Caspase-3 activation was confirmed by both caspase activity assay and GloTM luciferase assay. One dose of doxorubicin treatment induced a dramatic increase in BLI intensity as early as 24 h after treatment in 22B-pcFluc-DEVD xenografted tumors. Sustained signal increase was observed for the first 3 days and the fluorescent signal from ex vivo TUNEL staining was consistent with BLI imaging results. Long-term imaging revealed that BLI signal consistently increased and reached a maximum at around day 12 after the treatment with one dose of Doxil. Conclusions: BLI of apoptosis with pcFluc-DEVD as a reporter gene facilitates the determination of kinetics of the apoptotic process in a real-time manner, which provides a unique tool for drug development and therapy response monitoring.

Niu, Gang; Zhu, Lei; Ho, Don N.; Zhang, Fan; Gao, Haokao; Quan, Qimeng; Hida, Naoki; Ozawa, Takeaki; Liu, Gang; Chen, Xiaoyuan

2013-01-01

15

Longitudinal bioluminescence imaging of the dynamics of Doxorubicin induced apoptosis.  

UK PubMed Central (United Kingdom)

Objectives: Most chemotherapy agents cause tumor cell death primarily by the induction of apoptosis. The ability to noninvasively image apoptosis in vivo could dramatically benefit pre-clinical and clinical evaluation of chemotherapeutics targeting the apoptotic pathway. This study aims to visualize the dynamics of apoptotic process with temporal bioluminescence imaging (BLI) using an apoptosis specific bioluminescence reporter gene. Methods: Both UM-SCC-22B human head and neck squamous carcinoma cells and 4T1 murine breast cancer cells were genetically modified with a caspase-3 specific cyclic firefly luciferase reporter gene (pcFluc-DEVD). Apoptosis induced by different concentrations of doxorubicin in the transfected cells was evaluated by both annexin V staining and BLI. Longitudinal BLI was performed in xenografted tumor models at different time points after doxorubicin or Doxil treatment, to evaluate apoptosis. After imaging, DNA fragmentation in apoptotic cells was assessed in frozen tumor sections using TUNEL staining. Results: Dose- and time-dependent apoptosis induced by doxorubicin in pcFluc-DEVD transfected UM-SCC-22B and 4T1 cells was visualized and quantified by BLI. Caspase-3 activation was confirmed by both caspase activity assay and Glo(TM) luciferase assay. One dose of doxorubicin treatment induced a dramatic increase in BLI intensity as early as 24 h after treatment in 22B-pcFluc-DEVD xenografted tumors. Sustained signal increase was observed for the first 3 days and the fluorescent signal from ex vivo TUNEL staining was consistent with BLI imaging results. Long-term imaging revealed that BLI signal consistently increased and reached a maximum at around day 12 after the treatment with one dose of Doxil. Conclusions: BLI of apoptosis with pcFluc-DEVD as a reporter gene facilitates the determination of kinetics of the apoptotic process in a real-time manner, which provides a unique tool for drug development and therapy response monitoring.

Niu G; Zhu L; Ho DN; Zhang F; Gao H; Quan Q; Hida N; Ozawa T; Liu G; Chen X

2013-01-01

16

Continuous, real-time bioimaging of chemical bioavailability and toxicology using autonomously bioluminescent human cell lines  

Science.gov (United States)

Bioluminescent imaging is an emerging biomedical surveillance strategy that uses external cameras to detect in vivo light generated in small animal models of human physiology or in vitro light generated in tissue culture or tissue scaffold mimics of human anatomy. The most widely utilized of reporters is the firefly luciferase (luc) gene; however, it generates light only upon addition of a chemical substrate, thus only generating intermittent single time point data snapshots. To overcome this disadvantage, we have demonstrated substrate-independent bioluminescent imaging using an optimized bacterial bioluminescence (lux) system. The lux reporter produces bioluminescence autonomously using components found naturally within the cell, thereby allowing imaging to occur continuously and in real-time over the lifetime of the host. We have validated this technology in human cells with demonstrated chemical toxicological profiling against exotoxin exposures at signal strengths comparable to existing luc systems (~1.33 × 107 photons/second). As a proof-in-principle demonstration, we have engineered breast carcinoma cells to express bioluminescence for real-time screening of endocrine disrupting chemicals and validated detection of 17?-estradiol (EC50 = ~ 10 pM). These and other applications of this new reporter technology will be discussed as potential new pathways towards improved models of target chemical bioavailability, toxicology, efficacy, and human safety.

Xu, Tingting; Close, Dan M.; Webb, James D.; Price, Sarah L.; Ripp, Steven A.; Sayler, Gary S.

2013-05-01

17

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)

2010-01-01

18

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 for the exact quantitative analysis in various light imaging equipment with presenting linear response behavior of constant light emitting sources to measurement time

2009-01-01

19

Flexible peritoneal windows for quantitative fluorescence and bioluminescence preclinical imaging.  

UK PubMed Central (United Kingdom)

At present, there is considerable interest in the use of in vivo fluorescence and bioluminescence imaging to track the onset and progression of pathologic processes in preclinical models of human disease. Optical quantitation of such phenomena, however, is often problematic, frequently complicated by the overlying tissue's scattering and absorption of light, as well as the presence of endogenous cutaneous and subcutaneous fluorophores. To partially circumvent this information loss, we report here the development of flexible, surgically implanted, transparent windows that enhance quantitative in vivo fluorescence and bioluminescence imaging of optical reporters. These windows are metal and glass free and thus compatible with computed tomography, magnetic resonance imaging, positron emission tomography, and single-photon emission computed tomography; they also permit visualization of much larger areas with fewer impediments to animal locomotion and grooming than those previously described. To evaluate their utility in preclinical imaging, we surgically implanted these windows in the abdominal walls of female athymic nude mice and subsequently inoculated each animal with 1 × 10(4) to 1 × 10(6) bioluminescent human ovarian cancer cells (SKOV3ip.1-luc). Longitudinal imaging studies of fenestrated animals revealed up to 48-fold gains in imaging sensitivity relative to nonfenestrated animals, with relatively few complications, allowing wide-field in vivo visualization of nascent metastatic ovarian cancer colonization.

Souris JS; Hickson JA; Msezane L; Rinker-Schaeffer CW; Chen CT

2013-01-01

20

Bioluminescent imaging (BLI) to improve and refine traditional murine models of tumor growth and metastasis.  

Science.gov (United States)

Bioluminescent imaging (BLI) permits sensitive in vivo detection and quantification of cells specifically engineered to emit visible light. Three stable human tumor cell lines engineered to express luciferase were assessed for their tumorigenicity in subcutaneous, intravenous and spontaneous metastasis models. Bioluminescent PC-3M-luc-C6 human prostate cancer cells were implanted subcutaneously into SCID-beige mice and were monitored for tumor growth and response to 5-FU and mitomycin C treatments. Progressive tumor development and inhibition/regression following drug treatment were observed and quantified in vivo using BLI. Imaging data correlated to standard external caliper measurements of tumor volume, but bioluminescent data permitted earlier detection of tumor growth. In a lung colonization model, bioluminescent A549-luc-C8 human lung cancer cells were injected intravenously and lung metastases were monitored in vivo by whole animal imaging. Anesthetized mice were imaged weekly allowing a temporal assessment of in vivo lung tumor growth. This longitudinal study design permitted an accurate, real-time evaluation of tumor burden in the same animals over time. End-point bioluminescence measured in vivo correlated to total lung weight at necropsy. For a spontaneous metastatic tumor model, bioluminescent HT-29-luc-D6 human colon cancer cells implanted subcutaneously produced metastases to lung and lymph nodes in SCID-beige mice. Both primary tumors and micrometastases were detected by BLI in vivo. Ex vivo imaging of excised lung lobes and lymph nodes confirmed the in vivo signals and indicated a slightly higher frequency of metastasis in some mice. Levels of bioluminescence from in vivo and ex vivo images corresponded to the frequency and size of metastatic lesions in lungs and lymph nodes as subsequently confirmed by histology. In summary, BLI provided rapid, non-invasive monitoring of tumor growth and regression in animals. Its application to traditional oncology animal models offers quantitative and sensitive analysis of tumor growth and metastasis. The ability to temporally assess tumor development and responses to drug therapies in vivo also improves upon current standard animal models that are based on single end point data. PMID:14713107

Jenkins, Darlene E; Oei, Yoko; Hornig, Yvette S; Yu, Shang-Fan; Dusich, Joan; Purchio, Tony; Contag, Pamela R

2003-01-01

 
 
 
 
21

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

Energy Technology Data Exchange (ETDEWEB)

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

22

Neuronal network imaging in acute slices using ca(2+) sensitive bioluminescent reporter.  

UK PubMed Central (United Kingdom)

Genetically encoded indicators are valuable tools to study intracellular signaling cascades in real time using fluorescent or bioluminescent imaging techniques. Imaging of Ca(2+) indicators is widely used to record transient intracellular Ca(2+) increases associated with bioelectrical activity. The natural bioluminescent Ca(2+) sensor aequorin has been historically the first Ca(2+) indicator used to address biological questions. Aequorin imaging offers several advantages over fluorescent reporters: it is virtually devoid of background signal; it does not require light excitation and interferes little with intracellular processes. Genetically encoded sensors such as aequorin are commonly used in dissociated cultured cells; however it becomes more challenging to express them in differentiated intact specimen such as brain tissue. Here we describe a method to express a GFP-aequorin (GA) fusion protein in pyramidal cells of neocortical acute slices using recombinant Sindbis virus. This technique allows expressing GA in several hundreds of neurons on the same slice and to perform the bioluminescence recording of Ca(2+) transients in single neurons or multiple neurons simultaneously.

Tricoire L; Lambolez B

2014-01-01

23

Bioluminescence-based imaging technique for pressure measurement in water  

Science.gov (United States)

The dinoflagellate Pyrocystis lunula emits light in response to water motion. We developed a new imaging technique for measuring pressure using plankton that emits light in response to mechanical stimulation. The bioluminescence emitted by P. lunula was used to measure impact water pressure produced using weight-drop tests. The maximum mean luminescence intensity correlated with the maximum impact pressure that the cells receive when the circadian and diurnal biological rhythms are appropriately controlled. Thus, with appropriate calibration of experimentally determined parameters, the dynamic impact pressure can be estimated by measuring the cell-flash distribution. Statistical features of the evolution of flash intensity and the probability distribution during the impacting event, which are described by both biological and mechanical response parameters, are also discussed in this paper. The practical applicability of this bioluminescence imaging technique is examined through a water drop test. The maximum dynamic pressure, occurring at the impact of a water jet against a wall, was estimated from the flash intensity of the dinoflagellate.

Watanabe, Yasunori; Tanaka, Yasufumi

2011-07-01

24

In vivo bioluminescent imaging of virus-mediated gene transfer and transduced cell transplantation in the intervertebral disc.  

UK PubMed Central (United Kingdom)

STUDY DESIGN: Work presented here used a small animal model to demonstrate the feasibility and usefulness of in vivo bioluminescent imaging to studying degenerative disc disease. OBJECTIVES: To determine the utility of in vivo bioluminescent imaging to monitor the temporal and spatial expression of genetically modified cells within the intervertebral disc of a rodent model. SUMMARY OF THE BACKGROUND DATA: Noninvasive imaging of genetically engineered cells in the spine has the advantage of allowing events to be tracked without killing the animal and can be used to follow the time course of a particular therapy. Results are presented on the use of Sprague-Dawley rats in experimental studies in which the luciferase reporter gene was delivered to the lumbar intervertebral disc through adenovirus-mediated or cell-based transfer techniques to demonstrate the feasibility to monitor gene expression noninvasively over time. METHODS: Tissue culture, disc surgery, and in vivo bioluminescent imaging were used. The intervertebral disc of the rat was either injected in situ with an adenovirus containing the luciferase reporter gene or implanted with fat, bone marrow or intervertebral disc cells transduced ex vivo and contained in a bioresorbable carrier. Results were assessed with in vivo bioluminescent imaging at several time points. CONCLUSION: Data from 11 animals were obtained with imaging up to 14 days. To our knowledge, this is the first description of in vivo bioluminescence imaging to study spinal conditions. We have characterized the relative expression of three cell types transduced with the Ad-luc virus by ex vivo transfection followed by cell implantation in the rat spine and compared them to one another and to direct infection of Ad-luc adenovirus in situ. Our results demonstrate the feasibility of tracing genetically altered cells in the spine. This technique has the potential to be used to noninvasively track the fate and expression of therapeutic genes within the spine of small animals used in disc research.

Leo BM; Li X; Balian G; Anderson DG

2004-04-01

25

Luminol-based bioluminescence imaging of mouse mammary tumors.  

UK PubMed Central (United Kingdom)

Polymorphonuclear neutrophils (PMNs) are the most abundant circulating blood leukocytes. They are part of the innate immune system and provide a first line of defense by migrating toward areas of inflammation in response to chemical signals released from the site. Some solid tumors, such as breast cancer, also cause recruitment and activation of PMNs and release of myeloperoxidase. In this study, we demonstrate that administration of luminol to mice that have been transplanted with 4T1 mammary tumor cells permits the detection of myeloperoxidase activity, and consequently, the location of the tumor. Luminol allowed detection of activated PMNs only two days after cancer cell transplantation, even though tumors were not yet palpable. In conclusion, luminol-bioluminescence imaging (BLI) can provide a pathway towards detection of solid tumors at an early stage in preclinical tumor models.

Alshetaiwi HS; Balivada S; Shrestha TB; Pyle M; Basel MT; Bossmann SH; Troyer DL

2013-09-01

26

Image analyzing method to evaluate in situ bioluminescence from an obligate anaerobe cultivated under various dissolved oxygen concentrations.  

UK PubMed Central (United Kingdom)

An image analyzing method was developed to evaluate in situ bioluminescence expression, without exposing the culture sample to the ambient oxygen atmosphere. Using this method, we investigated the effect of dissolved oxygen concentration on bioluminescence from an obligate anaerobe Bifidobacterium longum expressing bacterial luciferase which catalyzes an oxygen-requiring bioluminescent reaction.

Ninomiya K; Yamada R; Matsumoto M; Fukiya S; Katayama T; Ogino C; Shimizu N

2013-02-01

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Real-time bioluminescent tracking of cellular population dynamics.  

Science.gov (United States)

Cellular population dynamics are routinely monitored across many diverse fields for a variety of purposes. In general, these dynamics are assayed either through the direct counting of cellular aliquots followed by extrapolation to the total population size, or through the monitoring of signal intensity from any number of externally stimulated reporter proteins. While both viable methods, here we describe a novel technique that allows for the automated, non-destructive tracking of cellular population dynamics in real-time. This method, which relies on the detection of a continuous bioluminescent signal produced through expression of the bacterial luciferase gene cassette, provides a low cost, low time-intensive means for generating additional data compared to alternative methods. PMID:24166372

Close, Dan; Xu, Tingting; Ripp, Steven; Sayler, Gary

2014-01-01

28

Bioluminescence imaging of caspase-3 activity in mouse liver.  

UK PubMed Central (United Kingdom)

Apoptosis is an essential process for the maintenance of liver physiology. The ability to noninvasively image apoptosis in livers would provide unique insights into its role in liver disease processes. In the present work, we established a stable mouse model by hydrodynamics methods to study the activity of caspase-3 and evaluate the effect of the apoptosis inhibitors in mouse livers under true physiological conditions by bioluminescence imaging. The reporter plasmid attB-ANLuc(DEVD)BCLuc that contains fragment of attB and ANLuc(DEVD)BCLuc was codelivered with the mouse-codon optimized ?C31 (?C31o) integrase plasmids specifically to mouse liver by hydrodynamic injection procedure. Then, ?C31o integrase mediated intramolecular recombination between wild-type attB and attP site in mice, and thus the reporter expression cassette attB-ANLuc(DEVD)BCLuc was integrated permanently into mouse liver chromosome. We used these mice to characterize in vivo activation of caspase-3 upon treatment with LPS/D-GalN. Our data show that liver apoptosis could be reflected by the activity of luciferase. The shRNA targeting caspase-3 protein or apoptosis inhibitors could effectively downregulate luciferase activity in vivo. Also, this model could be used to measure caspase-3 activation during inflammatory and infectious events in vivo as verified by infected with MHV-3. This model could be used for screening anti-apoptosis compounds target mouse livers.

Fu Q; Duan X; Yan S; Wang L; Zhou Y; Jia S; Du J; Wang X; Zhang Y; Zhan L

2013-08-01

29

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

Directory of Open Access Journals (Sweden)

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; McCabe Tulene C; de Bruxelles Guy L; Roberts Michael R

2004-01-01

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

UK PubMed Central (United Kingdom)

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. Very little is known regarding pathogenesis or treatment of glanders. We investigated the use of bioluminescent reporter constructs to monitor the dynamics of infection as well as the efficacy of therapeutics for B. mallei in real-time. A stable luminescent reporter B. mallei strain was created using the pUTmini-Tn5::luxKm2 plasmid and used to monitor glanders in the BALB/c murine model. Mice were infected via the intranasal route with 5?×?10(3) bacteria and monitored by BLI at 24, 48, and 72?h. We verified that our reporter construct maintained similar virulence and growth kinetics compared to wild-type B. mallei and confirmed that it maintains luminescent stability in the presence or absence of antibiotic selection. The luminescent signal was initially seen in the lungs, and progressed to the liver and spleen over the course of infection. We demonstrated that antibiotic treatment 24?h post-infection resulted in reduction of bioluminescence that can be attributed to decreased bacterial burden in target organs. These findings suggest that BLI can be used to monitor disease progression and efficacy of therapeutics during glanders infections. Finally, we report an alternative method to mini-Tn5::luxKm2 transposon using mini-Tn7-lux elements that insert site-specifically at known genomic attachment sites and that can also be used to tag bacteria.

Massey S; Johnston K; Mott TM; Judy BM; Kvitko BH; Schweizer HP; Estes DM; Torres AG

2011-01-01

31

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

Directory of Open Access Journals (Sweden)

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.

Li Limei; Fei Zhaoliang; Ren Jianke; Sun Ruilin; Liu Zhihui; Sheng Zhejin; Wang Long; Sun Xia; Yu Jun; Wang Zhugang; Fei Jian

2008-01-01

32

Bioluminescence imaging of fungal biofilm development in live animals.  

Science.gov (United States)

Fungal biofilms formed on various types of medical implants represent a major problem for hospitalized patients. These biofilms and related infections are usually difficult to treat because of their resistance to the classical antifungal drugs. Animal models are indispensable for investigating host-pathogen interactions and for identifying new antifungal targets related to biofilm development. A limited number of animal models is available that can be used for testing novel antifungal drugs in vivo against C. albicans, one of the most common pathogens causing fungal biofilms. Fungal load in biofilms in these models is traditionally analyzed postmortem, requiring host sacrifice and enumeration of microorganisms from individual biofilms in order to evaluate the amount of colony forming units and the efficacy of antifungal treatment. Bioluminescence imaging (BLI) made compatible with small animal models for in vivo biofilm formation is a valuable noninvasive tool to follow-up biofilm development and its treatment longitudinally, reducing the number of animals needed for such studies. Due to the nondestructive and noninvasive nature of BLI, the imaging procedure can be repeated in the same animal, allowing follow-up of the biofilm growth in vivo without removing the implanted device or detaching the biofilm from its substrate. The method described here introduces BLI of C. albicans biofilm formation in vivo on subcutaneously implanted catheters in mice. One of the main challenges to overcome for BLI of fungi is the hampered intracellular substrate delivery through the fungal cell wall, which is managed by using extracellularly located Gaussia luciferase. Although detecting a quantifiable in vivo BLI signal from biofilms formed on the inside of implanted catheters is challenging, BLI proved to be a practical tool in the study of fungal biofilms. This method describing the use of BLI for in vivo follow-up of device-related fungal biofilm formation has the potential for efficient in vivo screening for interesting genes of the pathogen and the host involved in C. albicans biofilm formation as well as for testing novel antifungal therapies. PMID:24166376

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

2014-01-01

33

Bioluminescence imaging of fungal biofilm development in live animals.  

UK PubMed Central (United Kingdom)

Fungal biofilms formed on various types of medical implants represent a major problem for hospitalized patients. These biofilms and related infections are usually difficult to treat because of their resistance to the classical antifungal drugs. Animal models are indispensable for investigating host-pathogen interactions and for identifying new antifungal targets related to biofilm development. A limited number of animal models is available that can be used for testing novel antifungal drugs in vivo against C. albicans, one of the most common pathogens causing fungal biofilms. Fungal load in biofilms in these models is traditionally analyzed postmortem, requiring host sacrifice and enumeration of microorganisms from individual biofilms in order to evaluate the amount of colony forming units and the efficacy of antifungal treatment. Bioluminescence imaging (BLI) made compatible with small animal models for in vivo biofilm formation is a valuable noninvasive tool to follow-up biofilm development and its treatment longitudinally, reducing the number of animals needed for such studies. Due to the nondestructive and noninvasive nature of BLI, the imaging procedure can be repeated in the same animal, allowing follow-up of the biofilm growth in vivo without removing the implanted device or detaching the biofilm from its substrate. The method described here introduces BLI of C. albicans biofilm formation in vivo on subcutaneously implanted catheters in mice. One of the main challenges to overcome for BLI of fungi is the hampered intracellular substrate delivery through the fungal cell wall, which is managed by using extracellularly located Gaussia luciferase. Although detecting a quantifiable in vivo BLI signal from biofilms formed on the inside of implanted catheters is challenging, BLI proved to be a practical tool in the study of fungal biofilms. This method describing the use of BLI for in vivo follow-up of device-related fungal biofilm formation has the potential for efficient in vivo screening for interesting genes of the pathogen and the host involved in C. albicans biofilm formation as well as for testing novel antifungal therapies.

Vande Velde G; Kucharíková S; Van Dijck P; Himmelreich U

2014-01-01

34

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 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.

2005-01-01

35

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

Energy Technology Data Exchange (ETDEWEB)

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

36

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

Directory of Open Access Journals (Sweden)

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.

Xia Jixiang; Martinez Angela; Daniell Henry; Ebert Steven N

2011-01-01

37

Bioluminescence imaging correlates with tumor progression in an orthotopic mouse model of lung cancer.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVES: To determine whether bioluminescence imaging of human lung cancer cells growing in an orthotopic murine model provides a sensitive tool for monitoring tumor progression in athymic nude mice. METHODS: Human lung cancer (A549) cells were stably transfected with the firefly luciferase gene and inoculated into the right lung of athymic nude mice. Seven days after inoculation tumor growth was evaluated using the Kodak in-vivo Imaging System FX and continued to be monitored on a weekly basis. RESULTS: In duplicate experiments, human lung cancer tumors formed in 90% of animal's injected orthotopically. The mean intensity of the bioluminescence signal emitted from the lung cancer cells increased logarithmically during the course of study. Mice with positive bioluminescence signaling had confirmed tumors by microscopic histological analysis. Bioluminescence activity had a strong correlation with the tumor volume as determined histologically. CONCLUSIONS: Bioluminescence intensity directly correlates with tumor volume and therefore offers a reliable approach for detecting and monitoring the growth of human lung cancer cells in orthotopic murine models.

Madero-Visbal RA; Colon JF; Hernandez IC; Limaye A; Smith J; Lee CM; Arlen PA; Herrera L; Baker CH

2012-03-01

38

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

Energy Technology Data Exchange (ETDEWEB)

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

39

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

International Nuclear Information System (INIS)

[en] 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

2009-01-01

40

A bioluminescent transgenic mouse model: Real-time in vivo imaging of antioxidant EC-SOD gene expression and regulation by interferon gamma.  

Science.gov (United States)

Extracellular superoxide dismutase (EC-SOD) is the main antioxidant enzyme in the extracellular matrix. We developed transgenic mice to analyze the EC-SOD promoter activity in vivo in real time and to identify the important cis-elements flanking the 5' region of the murine EC-SOD gene. Using this model, we demonstrated that luciferase reporter activity correlates closely with endogenous EC-SOD expression, although several interesting differences were also observed. Specifically, luciferase activity was detected at the highest levels in testes, aorta and perirenal fat. Reporter expression was regulated by interferon gamma, a finding that is in agreement with published endogenous EC-SOD gene expression studies. Thus, the 5'-flanking region of mouse EC-SOD gene is responsible, at least in part, for cell specific and inducible expression. PMID:23886589

Zelko, Igor N; Stepp, Marcus W; Folz, Rodney J

2013-07-22

 
 
 
 
41

Bioluminescence Imaging of Heme Oxygenase-1 Upregulation in the Gua Sha Procedure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol for bioluminescent optical imaging of HO-1-luciferase transgenic mice reported in this manuscript provides a rapid in vivo assay of the upregulat...

Kwong, Kenneth K.; Kloetzer, Lenuta; Wong, Kelvin K.; Ren, Jia-Qian; Kuo, Braden; Jiang, Yan; Chen, Y. Iris; Chan, Suk-Tak

42

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.  

UK PubMed Central (United Kingdom)

PURPOSE: 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. METHODS: Benzene ring (14)C(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. RESULTS: 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 (14)C-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% 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 (14)C-D-luciferin in firefly luciferase-expressing tissues could be observed in vivo. CONCLUSIONS: The data obtained with (14)C-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.

Berger F; Paulmurugan R; Bhaumik S; Gambhir SS

2008-12-01

43

A single-cell bioluminescence imaging system for monitoring cellular gene expression in a plant body.  

UK PubMed Central (United Kingdom)

Gene expression is a fundamental cellular process and expression dynamics are of great interest in life science. We succeeded in monitoring cellular gene expression in a duckweed plant, Lemna gibba, using bioluminescence reporters. Using particle bombardment, epidermal and mesophyll cells were transfected with the luciferase gene (luc+) under the control of a constitutive (CaMV35S) and a rhythmic (AtCCA1) promoter. Bioluminescence images were captured using an EM-CCD camera. Luminescent spots of the transfected cells in the plant body were quantitatively measured at the single-cell level. Luminescence intensities varied over a 1000-fold range among CaMV35S::luc+-transfected cells in the same plant body and showed a log-normal like frequency distribution. We monitored cellular gene expression under light-dark conditions by capturing bioluminescence images every hour. Luminescence traces of 50 or more individual cells in a frond were successfully obtained in each monitoring procedure. Rhythmic and constitutive luminescence behaviors were observed in cells transfected with AtCCA1::luc+ and CaMV35S::luc+, respectively. Diurnal rhythms were observed in every AtCCA1::luc+-introduced cell with traceable luminescence, and slight differences were detected in their rhythmic waveforms. Thus the single-cell bioluminescence monitoring system was useful for the characterization of cellular gene expression in a plant body.

Muranaka T; Kubota S; Oyama T

2013-09-01

44

Comparison of in vivo optical systems for bioluminescence and fluorescence imaging.  

UK PubMed Central (United Kingdom)

In vivo optical imaging has become a popular tool in animal laboratories. Currently, many in vivo optical imaging systems are available on the market, which often makes it difficult for research groups to decide which system fits their needs best. In this work we compared different commercially available systems, which can measure both bioluminescent and fluorescent light. The systems were tested for their bioluminescent and fluorescent sensitivity both in vitro and in vivo. The IVIS Lumina II was found to be most sensitive for bioluminescence imaging, with the Photon Imager a close second. Contrary, the Kodak system was, in vitro, the most sensitive system for fluorescence imaging. In vivo, the fluorescence sensitivity of the systems was similar. Finally, we examined the added value of spectral unmixing algorithms for in vivo optical imaging and demonstrated that spectral unmixing resulted in at least a doubling of the in vivo sensitivity. Additionally, spectral unmixing also enabled separate imaging of dyes with overlapping spectra which were, without spectral unmixing, not distinguishable.

Cool SK; Breyne K; Meyer E; De Smedt SC; Sanders NN

2013-09-01

45

Comparison of in vivo optical systems for bioluminescence and fluorescence imaging.  

Science.gov (United States)

In vivo optical imaging has become a popular tool in animal laboratories. Currently, many in vivo optical imaging systems are available on the market, which often makes it difficult for research groups to decide which system fits their needs best. In this work we compared different commercially available systems, which can measure both bioluminescent and fluorescent light. The systems were tested for their bioluminescent and fluorescent sensitivity both in vitro and in vivo. The IVIS Lumina II was found to be most sensitive for bioluminescence imaging, with the Photon Imager a close second. Contrary, the Kodak system was, in vitro, the most sensitive system for fluorescence imaging. In vivo, the fluorescence sensitivity of the systems was similar. Finally, we examined the added value of spectral unmixing algorithms for in vivo optical imaging and demonstrated that spectral unmixing resulted in at least a doubling of the in vivo sensitivity. Additionally, spectral unmixing also enabled separate imaging of dyes with overlapping spectra which were, without spectral unmixing, not distinguishable. PMID:23579930

Cool, Steven K; Breyne, Koen; Meyer, Evelyne; De Smedt, Stefaan C; Sanders, Niek N

2013-04-12

46

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

Directory of Open Access Journals (Sweden)

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; Weening Eric H; Frothingham Richard; Sempowski Gregory D; Miller Virginia L

2012-01-01

47

Subcellular dynamic imaging of protein-protein interactions in live cells by bioluminescence resonance energy transfer.  

UK PubMed Central (United Kingdom)

Protein functions rely on their ability to engage in specific protein-protein interactions and form complexes that are dynamically regulated by stimuli. Bioluminescence resonance energy transfer (BRET) is a highly sensitive technique, which allows monitoring of interaction between two proteins: one tagged with the luminescent donor Renilla luciferase, the other with a fluorescent acceptor such as YFP. We adapted this method to single-cell imaging. To this aim, we tag proteins of interest, transfect cells with these fusions, and use the high-sensitivity microscopy, combined with electron multiplying cooled charge-coupled device (EMCCD) cameras and improved bioluminescence probes. We thus achieve rapid acquisition of high-resolution BRET images and study the localization and dynamics of protein-protein interactions in individual live cells.

Perroy J

2010-01-01

48

Subcellular dynamic imaging of protein-protein interactions in live cells by bioluminescence resonance energy transfer.  

Science.gov (United States)

Protein functions rely on their ability to engage in specific protein-protein interactions and form complexes that are dynamically regulated by stimuli. Bioluminescence resonance energy transfer (BRET) is a highly sensitive technique, which allows monitoring of interaction between two proteins: one tagged with the luminescent donor Renilla luciferase, the other with a fluorescent acceptor such as YFP. We adapted this method to single-cell imaging. To this aim, we tag proteins of interest, transfect cells with these fusions, and use the high-sensitivity microscopy, combined with electron multiplying cooled charge-coupled device (EMCCD) cameras and improved bioluminescence probes. We thus achieve rapid acquisition of high-resolution BRET images and study the localization and dynamics of protein-protein interactions in individual live cells. PMID:19957139

Perroy, Julie

2010-01-01

49

Bioluminescence imaging of ? cells and intrahepatic insulin gene activity under normal and pathological conditions.  

Science.gov (United States)

In diabetes research, bioluminescence imaging (BLI) has been applied in studies of ?-cell impairment, development, and islet transplantation. To develop a mouse model that enables noninvasive imaging of ? cells, we generated a bacterial artificial chromosome (BAC) transgenic mouse in which a mouse 200-kbp genomic fragment comprising the insulin I gene drives luciferase expression (Ins1-luc BAC transgenic mouse). BLI of mice was performed using the IVIS Spectrum system after intraperitoneal injection of luciferin, and the bioluminescence signal from the pancreatic region analyzed. When compared with MIP-Luc-VU mice [FVB/N-Tg(Ins1-luc)VUPwrs/J] expressing luciferase under the control of the 9.2-kbp mouse insulin I promoter (MIP), the bioluminescence emission from Ins1-luc BAC transgenic mice was enhanced approximately 4-fold. Streptozotocin-treated Ins1-luc BAC transgenic mice developed severe diabetes concomitant with a sharp decline in the BLI signal intensity in the pancreas. Conversely, mice fed a high-fat diet for 8 weeks showed an increase in the signal, reflecting a decrease or increase in the ?-cell mass. Although the bioluminescence intensity of the islets correlated well with the number of isolated islets in vitro, the intensity obtained from a living mouse in vivo did not necessarily reflect an absolute quantification of the ?-cell mass under pathological conditions. On the other hand, adenovirus-mediated gene transduction of ?-cell-related transcription factors in Ins1-luc BAC transgenic mice generated luminescence from the hepatic region for more than 1 week. These results demonstrate that BLI in Ins1-luc BAC transgenic mice provides a noninvasive method of imaging islet ? cells and extrapancreatic activity of the insulin gene in the liver under normal and pathological conditions. PMID:23593212

Katsumata, Tokio; Oishi, Hisashi; Sekiguchi, Yukari; Nagasaki, Haruka; Daassi, Dhouha; Tai, Pei-Han; Ema, Masatsugu; Kudo, Takashi; Takahashi, Satoru

2013-04-04

50

Bioluminescence imaging of ? cells and intrahepatic insulin gene activity under normal and pathological conditions.  

UK PubMed Central (United Kingdom)

In diabetes research, bioluminescence imaging (BLI) has been applied in studies of ?-cell impairment, development, and islet transplantation. To develop a mouse model that enables noninvasive imaging of ? cells, we generated a bacterial artificial chromosome (BAC) transgenic mouse in which a mouse 200-kbp genomic fragment comprising the insulin I gene drives luciferase expression (Ins1-luc BAC transgenic mouse). BLI of mice was performed using the IVIS Spectrum system after intraperitoneal injection of luciferin, and the bioluminescence signal from the pancreatic region analyzed. When compared with MIP-Luc-VU mice [FVB/N-Tg(Ins1-luc)VUPwrs/J] expressing luciferase under the control of the 9.2-kbp mouse insulin I promoter (MIP), the bioluminescence emission from Ins1-luc BAC transgenic mice was enhanced approximately 4-fold. Streptozotocin-treated Ins1-luc BAC transgenic mice developed severe diabetes concomitant with a sharp decline in the BLI signal intensity in the pancreas. Conversely, mice fed a high-fat diet for 8 weeks showed an increase in the signal, reflecting a decrease or increase in the ?-cell mass. Although the bioluminescence intensity of the islets correlated well with the number of isolated islets in vitro, the intensity obtained from a living mouse in vivo did not necessarily reflect an absolute quantification of the ?-cell mass under pathological conditions. On the other hand, adenovirus-mediated gene transduction of ?-cell-related transcription factors in Ins1-luc BAC transgenic mice generated luminescence from the hepatic region for more than 1 week. These results demonstrate that BLI in Ins1-luc BAC transgenic mice provides a noninvasive method of imaging islet ? cells and extrapancreatic activity of the insulin gene in the liver under normal and pathological conditions.

Katsumata T; Oishi H; Sekiguchi Y; Nagasaki H; Daassi D; Tai PH; Ema M; Kudo T; Takahashi S

2013-01-01

51

Comparison of in vivo bioluminescence imaging and lavage biomarkers to assess pulmonary inflammation.  

Science.gov (United States)

Gram-negative bacterial endotoxin triggers innate immunity via TLR-4 and NF-kB signal activation. The aim of this study was to evaluate the use of transgenic mice expressing luciferase as a marker of NF-kB activation for exploring innate immune responses to pulmonary endotoxin exposure over time thus obviating the need for serial necropsies. Transgenic rNF-kB-Luc BALB/c mice were exposed to two different types of endotoxin (Neisseria meningitidis lipooligosaccharide, and Escherichia coli lipopolysaccharide) at multiple doses by nasal instillation. Bioluminescence was quantified in vivo at five time points in three separate experiments. In the fourth experiment lungs were imaged ex vivo 8h post exposure and tissue was analyzed for luciferase activity. Non-transgenic BALB/c mice were similarly exposed to lipooligosaccharide and bronchoalveolar lavage was assessed for neutrophil recruitment and IL-6. Non-transgenic BALB/c mice exhibited highly significant increases of IL-6 and neutrophils in bronchoalveolar lavage 4h after the exposure to instilled doses as low as 30EU/mouse. In contrast, luciferase imaging of NF-kB signal activation in vivo in transgenic rNF-kB-Luc mice did not show significant changes over time or over doses from 30EU to 300,000EU/mouse of nasally-instilled endotoxin. Ex vivo lung imaging 8h after endotoxin exposure to 3000EU demonstrated a strong signal. An intravenous LPS dose of 300,000EU/mouse produced a measurable luminescence signal in vivo. This non-terminal assessment method is useful only with extremely high doses of endotoxin that induce systemic injury and cannot be applied to research of occupational and environmental exposures at relevant levels of endotoxin. PMID:22133556

Hadina, Suzana; Wohlford-Lenane, Christine L; Thorne, Peter S

2011-11-23

52

Comparison of in vivo bioluminescence imaging and lavage biomarkers to assess pulmonary inflammation.  

UK PubMed Central (United Kingdom)

Gram-negative bacterial endotoxin triggers innate immunity via TLR-4 and NF-kB signal activation. The aim of this study was to evaluate the use of transgenic mice expressing luciferase as a marker of NF-kB activation for exploring innate immune responses to pulmonary endotoxin exposure over time thus obviating the need for serial necropsies. Transgenic rNF-kB-Luc BALB/c mice were exposed to two different types of endotoxin (Neisseria meningitidis lipooligosaccharide, and Escherichia coli lipopolysaccharide) at multiple doses by nasal instillation. Bioluminescence was quantified in vivo at five time points in three separate experiments. In the fourth experiment lungs were imaged ex vivo 8h post exposure and tissue was analyzed for luciferase activity. Non-transgenic BALB/c mice were similarly exposed to lipooligosaccharide and bronchoalveolar lavage was assessed for neutrophil recruitment and IL-6. Non-transgenic BALB/c mice exhibited highly significant increases of IL-6 and neutrophils in bronchoalveolar lavage 4h after the exposure to instilled doses as low as 30EU/mouse. In contrast, luciferase imaging of NF-kB signal activation in vivo in transgenic rNF-kB-Luc mice did not show significant changes over time or over doses from 30EU to 300,000EU/mouse of nasally-instilled endotoxin. Ex vivo lung imaging 8h after endotoxin exposure to 3000EU demonstrated a strong signal. An intravenous LPS dose of 300,000EU/mouse produced a measurable luminescence signal in vivo. This non-terminal assessment method is useful only with extremely high doses of endotoxin that induce systemic injury and cannot be applied to research of occupational and environmental exposures at relevant levels of endotoxin.

Hadina S; Wohlford-Lenane CL; Thorne PS

2012-01-01

53

Bioluminescence imaging of heme oxygenase-1 upregulation in the Gua Sha procedure.  

UK PubMed Central (United Kingdom)

Gua Sha is a traditional Chinese folk therapy that employs skin scraping to cause subcutaneous microvascular blood extravasation and bruises. The protocol for bioluminescent optical imaging of HO-1-luciferase transgenic mice reported in this manuscript provides a rapid in vivo assay of the upregulation of the heme oxygenase-1 (HO-1) gene expression in response to the Gua Sha procedure. HO-1 has long been known to provide cytoprotection against oxidative stress. The upregulation of HO-1, assessed by the bioluminescence output, is thought to represent an antioxidative response to circulating hemoglobin products released by Gua Sha. Gua Sha was administered by repeated strokes of a smooth spoon edge over lubricated skin on the back or other targeted body part of the transgenic mouse until petechiae (splinter hemorrhages) or ecchymosis (bruises) indicative of extravasation of blood from subcutaneous capillaries was observed. After Gua Sha, bioluminescence imaging sessions were carried out daily for several days to follow the dynamics of HO-1 expression in multiple internal organs.

Kwong KK; Kloetzer L; Wong KK; Ren JQ; Kuo B; Jiang Y; Chen YI; Chan ST; Young GS; Wong ST

2009-01-01

54

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

UK PubMed Central (United Kingdom)

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.

Daniel C; Poiret S; Dennin V; Boutillier D; Pot B

2013-02-01

55

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

Energy Technology Data Exchange (ETDEWEB)

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/cm{sup 2}/sr) from the knee joint transplanted with cells approximately increased 10-fold more than (9.43E+07p/s/cm{sup 2}/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 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.

Moon, Sung Min; Min, Jung Joon; Kim, Sung Mi; Bom, Hee Seung [Chonnam National University Medical School, Gwangju (Korea, Republic of); Oh, Suk Jung; Kang, Han Saem; Kim, Kwang Yoon [ECOBIO INC., Gwangju (Korea, Republic of); Kim, Young Ho [Chosun University, Gwangju (Korea, Republic of)

2005-07-01

56

Bioluminescence imaging of human embryonic stem cell-derived endothelial cells for treatment of myocardial infarction.  

UK PubMed Central (United Kingdom)

Myocardial infarction is a leading cause of mortality and morbidity worldwide, and current treatments fail to address the underlying scarring and cell loss, which is a major cause of heart failure after infarction. The novel strategy, therapeutic angiogenesis and/or vasculogenesis with endothelial progenitor cells transplantation holds great promise to increase blood flow in ischemic areas, thus rebuild the injured heart and reverse the heart failure. Given the potential of self-renewal and differentiation into virtually all cell types, human embryonic stem cells (hESCs) may provide an alternate source of therapeutic cells by allowing the derivation of large numbers of endothelial cells for therapeutic angiogenesis and/or vasculogenesis of ischemic heart diseases. Moreover, to fully understand the fate of implanted hESCs or hESC derivatives, investigators need to monitor the motility of cells in living animals over time. In this chapter, we describe the application of bioluminescence reporter gene imaging to track the transplanted hESC-derived endothelial cells for treatment of myocardial infarction. The technology of inducing endothelial cells from hESCs will also be discussed.

Su W; Leng L; Han Z; He Z; Li Z

2013-01-01

57

The Bioluminescent Imaging of Spontaneously Occurring Tumors in Immunocompetent ODD-Luciferase Bearing Transgenic Mice.  

UK PubMed Central (United Kingdom)

The imaging of spontaneously occurring tumors in mice poses many technical and logistical problems. Recently a mouse model was generated in which a chimeric protein consisting of HIF-1? oxygen-dependent degradation domain (ODD) fused to luciferase was ubiquitously expressed in all tissues. Hypoxic stress leads to the accumulation of ODD-luciferase in the tissues of this mouse model which can be identified by noninvasive bioluminescence measurement. Crossing this transgenic mouse with tumorigenic mice yields solid tumors with hypoxic cores that may be successfully imaged and characterized using the technique described herein.

Goldman SJ; Jin S

2014-01-01

58

The Bioluminescent Imaging of Spontaneously Occurring Tumors in Immunocompetent ODD-Luciferase Bearing Transgenic Mice.  

Science.gov (United States)

The imaging of spontaneously occurring tumors in mice poses many technical and logistical problems. Recently a mouse model was generated in which a chimeric protein consisting of HIF-1? oxygen-dependent degradation domain (ODD) fused to luciferase was ubiquitously expressed in all tissues. Hypoxic stress leads to the accumulation of ODD-luciferase in the tissues of this mouse model which can be identified by noninvasive bioluminescence measurement. Crossing this transgenic mouse with tumorigenic mice yields solid tumors with hypoxic cores that may be successfully imaged and characterized using the technique described herein. PMID:24166374

Goldman, Scott J; Jin, Shengkan

2014-01-01

59

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

International Nuclear Information System (INIS)

[en] The feasibility and limits in performing tomographic bioluminescence imaging with a combined optical-PET (OPET) system were 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 deg. C. The TOAST finite-element code was employed to simulate the diffuse transport of photons emitted from bioluminescence sources in the mouse. OPET measurements were simulated for single-point, two-point and distributed bioluminescence sources located in different organs such as the liver, the kidneys and the gut. An expectation maximization code was employed to recover the intensity and location of these simulated sources. It was found that spectrally resolved measurements were necessary in order to perform tomographic bioluminescence imaging. The true location of emission sources could be recovered if the mouse background optical properties were known a priori. The assumption of a homogeneous optical property background proved inadequate for describing photon transport in optically heterogeneous tissues and led to inaccurate source localization in the reconstructed images. The simulation results pointed out specific methodological challenges that need to be addressed before a practical implementation of OPET-based bioluminescence tomography is achieved

2005-09-07

60

Bioluminescence Imaging of Clavibacter michiganensis subsp. michiganensis Infection of Tomato Seeds and Plants ?  

Science.gov (United States)

Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes wilting and cankers, leading to severe economic losses in commercial tomato production worldwide. The disease is transmitted from infected seeds to seedlings and mechanically from plant to plant during seedling production, grafting, pruning, and harvesting. Because of the lack of tools for genetic manipulation, very little is known regarding the mechanisms of seed and seedling infection and movement of C. michiganensis subsp. michiganensis in grafted plants, two focal points for application of bacterial canker control measures in tomato. To facilitate studies on the C. michiganensis subsp. michiganensis movement in tomato seed and grafted plants, we isolated a bioluminescent C. michiganensis subsp. michiganensis strain using the modified Tn1409 containing a promoterless lux reporter. A total of 19 bioluminescent C. michiganensis subsp. michiganensis mutants were obtained. All mutants tested induced a hypersensitive response in Mirabilis jalapa and caused wilting of tomato plants. Real-time colonization studies of germinating seeds using a virulent, stable, constitutively bioluminescent strain, BL-Cmm17, showed that C. michiganensis subsp. michiganensis aggregated on hypocotyls and cotyledons at an early stage of germination. In grafted seedlings in which either the rootstock or scion was exposed to BL-Cmm17 via a contaminated grafting knife, bacteria were translocated in both directions from the graft union at higher inoculum doses. These results emphasize the use of bioluminescent C. michiganensis subsp. michiganensis to help better elucidate the C. michiganensis subsp. michiganensis-tomato plant interactions. Further, we demonstrated the broader applicability of this tool by successful transformation of C. michiganensis subsp. nebraskensis with Tn1409::lux. Thus, our approach would be highly useful to understand the pathogenesis of diseases caused by other subspecies of the agriculturally important C. michiganensis.

Xu, Xiulan; Miller, Sally A.; Baysal-Gurel, Fulya; Gartemann, Karl-Heinz; Eichenlaub, Rudolf; Rajashekara, Gireesh

2010-01-01

 
 
 
 
61

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

Energy Technology Data Exchange (ETDEWEB)

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.

Comsa, D C; Farrell, T J; Patterson, M S [Juravinski Cancer Centre and McMaster University, 699 Concession Street, Hamilton, Ontario L8V 5C2 (Canada)

2006-08-07

62

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

2006-08-07

63

Functional imaging of Rel expression in inflammatory processes using bioluminescence imaging system in transgenic mice.  

UK PubMed Central (United Kingdom)

c-Rel plays important roles in many inflammatory diseases. Revealing the dynamic expression of c-Rel in disease processes in vivo is critical for understanding c-Rel functions and for developing anti-inflammatory drugs. In this paper, a transgenic mouse line, B6-Tg(c-Rel-luc)(Mlit), which incorporated the transgene firefly luciferase driven by a 14.5-kb fragment containing mouse c-Rel gene Rel promoter, was generated to monitor Rel expression in vivo. Luciferase expression could be tracked in living mice by the method of bioluminescence imaging in a variety of inflammatory processes, including LPS induced sepsis and EAE disease model. The luciferase expression in transgenic mice was comparable to the endogenous Rel expression and could be suppressed by administration of anti-inflammatory drug dexamethasone or aspirin. These results indicate that the B6-Tg(c-Rel-luc)(Mlit) mouse is a valuable animal model to study Rel expression in physiological and pathological processes, and the effects of various drug treatments in vivo.

Yang X; Jing H; Zhao K; Sun R; Liu Z; Ying Y; Ci L; Kuang Y; Huang F; Wang Z; Fei J

2013-01-01

64

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

Energy Technology Data Exchange (ETDEWEB)

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 10{sup 5} 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 (9.2x10{sup 3}p/s/cm{sup 2}/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 transplantation.

Min, Jung Joon; Ahn, Young Keun; Moon, Sung Min; Lim, Sang Yup; Yun, Kyung Ho; Heo, Young Jun; Song, Ho Chun; Jeong, Myung Ho; Bom, Hee Seung [School of Medicine, Chonnam National University, Gwangju (Korea, Republic of)

2004-07-01

65

In vivo mouse ^{99m}Tc SPECT scans with bioluminescence imaging validation.  

UK PubMed Central (United Kingdom)

The aim of this in vivo study was to evaluate the feasibility of ^{99m}Tc-labeled cartilage link protein (CLP) probe for the single-photon emission computed tomography (SPECT) of lung cancer. Xenograft mouse model were established from a luciferase expressing cell line derived from a human lung cancer. Bioluminescence imaging (BLI) was carried out prior to ^{99m}Tc-CLP and ^{99m}Tc-methoxyisobutyl isonitrile (MIBI) SPECT scans. The image quality of ^{99m}Tc-CLP scan was validated with BLI and compared with well established ^{99m}Tc-MIBI scan. Results of multimodal imaging analyses suggested that ^{99m}Tc-CLP was a sensitive and reliable SPECT agent for lung cancer imaging.

Liang ZX; Qiang YG; Liao YH; Zhu XS; Huang Z; Zhang XP; Wang L

2013-01-01

66

Monitoring of tumour progression using bioluminescence imaging and computed tomography scanning in a nude mouse orthotopic model of human small cell lung cancer.  

UK PubMed Central (United Kingdom)

Human small cell lung carcinoma (SCLC) is the most aggressive type of lung cancer but no clinically relevant animal model has been developed to date. Such a model would be valuable to study the molecular aspects of tumour progression and to test the effectiveness of new treatment agents. We generated a reproducible and reliable nude mouse orthotopic model of human SCLC with NCI-H209 tumour cells genetically modified to express firefly luciferase. Cells were analysed for long-term stability of bioluminescence and a clone was passaged twice subcutaneously to enhance tumorigenicity. Cells resuspended in Matrigel and/or EDTA RPMI medium containing a (99m)Tc-labelled tin colloid used as tracer were implanted intrabronchially with a catheter inserted into the trachea and positioned in the main bronchus using X-ray-guided imaging. Deposition of cells into the lung was then assessed by scintigraphy. The growth of the primary tumour was sensitively and non-invasively followed by bioluminescence imaging that allowed real-time monitoring of tumour progression in the same animals over a 2-12-week period. Additional 3D bioluminescence imaging and computed tomography scanning were used to document tumour location and measurements that were confirmed by histological analyses. In conclusion, this original nude mouse orthotopic model resembles various stages of human small cell lung cancer, and therefore could be used to evaluate new treatment strategies.

Iochmann S; Lerondel S; Bléchet C; Lavergne M; Pesnel S; Sobilo J; Heuzé-Vourc'h N; Le Pape A; Reverdiau P

2012-07-01

67

Monitoring of disease progression by bioluminescence imaging and magnetic resonance imaging in an animal model of hematologic malignancy.  

UK PubMed Central (United Kingdom)

OBJECTIVE: We evaluated disease progression in a mouse model of a hematologic malignancy using a multimodality approach that included bioluminescence imaging (BLI) and magnetic resonance imaging (MRI). We aimed to examine the feasibility and capability of BLI and MRI and to establish techniques for quantitative assessment of disease severity. METHODS: Mice were inoculated intravenously with Ba/F3 cells transduced with firefly luciferase and p190 BCR-ABL genes. Disease progression in a given mouse was observed longitudinally by in vivo BLI and MRI (n = 5). Imaging studies, including in vivo BLI and MRI of living mice and ex vivo BLI of excised organs, were also performed at various time points (n = 4, 3, 4, and 4 at 1, 2, 3, and 4 weeks after cell inoculation). RESULTS: Longitudinal studies allowed the assessment of disease progression for each mouse, and an approximately 4-log increase in whole-body BLI signal was shown after initial detection. MRI demonstrated progressive hepatosplenomegaly and growth of hepatic nodules. Ex vivo BLI demonstrated proliferation of the implanted cells in various organs including bone marrow, and the signal for each organ increased with time (Spearman's rank correlation coefficient, R = 0.831-0.914) and as the whole-body signal, observed by in vivo BLI, increased (R = 0.921-0.982). MRI measurements of liver and spleen volumes were shown to have excellent accuracy and volume increases significantly correlated with the BLI organ signal (liver, R = 0.875; spleen, R = 0.971). CONCLUSION: BLI and MRI allow repeated assessment of disease progression in a mouse model of a hematologic malignancy and provide quantitative markers of disease severity. BLI and MRI measurements reveal different details of disease progression and may play complementary roles in comprehensive assessment.

Inoue Y; Izawa K; Tojo A; Nomura Y; Sekine R; Oyaizu N; Ohtomo K

2007-03-01

68

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

UK PubMed Central (United Kingdom)

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.

Virostko J; Radhika A; Poffenberger G; Dula AN; Moore DJ; Powers AC

2013-01-01

69

Firefly luciferase-based dynamic bioluminescence imaging: a noninvasive technique to assess tumor angiogenesis.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Bioluminescence imaging (BLI) is emerging as a cost-effective, high-throughput, noninvasive, and sensitive imaging modality to monitor cell growth and trafficking. We describe the use of dynamic BLI as a noninvasive method of assessing vessel permeability during brain tumor growth. METHODS: With the use of stereotactic technique, 10 firefly luciferase-transfected GL26 mouse glioblastoma multiforme cells were injected into the brains of C57BL/6 mice (n = 80). After intraperitoneal injection of D-luciferin (150 mg/kg), serial dynamic BLI was performed at 1-minute intervals (30 seconds exposure) every 2 to 3 days until death of the animals. The maximum intensity was used as an indirect measurement of tumor growth. The adjusted slope of initial intensity (I90/Im) was used as a proxy to monitor the flow rate of blood into the vascular tree. Using a modified Evans blue perfusion protocol, we calculated the relative permeability of the vascular tree at various time points. RESULTS: Daily maximum intensity correlated strongly with tumor volume. At postinjection day 23, histology and BLI demonstrated an exponential growth of the tumor mass. Slopes were calculated to reflect the flow in the vessels feeding the tumor (adjusted slope = I90/Im). The increase in BLI intensity was correlated with a decrease in adjusted slope, reflecting a decrease in the rate of blood flow as tumor volume increased (y = 93.8e-0.49, R2 = 0.63). Examination of calculated slopes revealed a peak in permeability around postinjection day 20 (n = 42, P < .02 by 1-way analysis of variance) and showed a downward trend in relation to both postinjection day and maximum intensity observed; as angiogenesis progressed, tumor vessel caliber increased dramatically, resulting in sluggish but increased flow. This trend was correlated with Evans blue histology, revealing an increase in Evans blue dye uptake into the tumor, as slope calculated by BLI increases. CONCLUSION: Dynamic BLI is a practical, noninvasive technique that can semiquantitatively monitor changes in vascular permeability and therefore facilitate the study of tumor angiogenesis in animal models of disease.

Sun A; Hou L; Prugpichailers T; Dunkel J; Kalani MA; Chen X; Kalani MY; Tse V

2010-04-01

70

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 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

2003-01-01

71

Bioluminescence and magnetic resonance imaging of macrophage homing to experimental abdominal aortic aneurysms.  

UK PubMed Central (United Kingdom)

Macrophage infiltration is a prominent feature of abdominal aortic aneurysm (AAA) progression. We used a combined imaging approach with bioluminescence (BLI) and magnetic resonance imaging (MRI) to study macrophage homing and accumulation in experimental AAA disease. Murine AAAs were created via intra-aortic infusion of porcine pancreatic elastase. Mice were imaged over 14 days after injection of prepared peritoneal macrophages. For BLI, macrophages were from transgenic mice expressing luciferase. For MRI, macrophages were labeled with iron oxide particles. Macrophage accumulation during aneurysm progression was observed by in situ BLI and by in vivo 7T MRI. Mice were sacrificed after imaging for histologic analysis. In situ BLI (n ?=? 32) demonstrated high signal in the AAA by days 7 and 14, which correlated significantly with macrophage number and aortic diameter. In vivo 7T MRI (n ?=? 13) at day 14 demonstrated T?* signal loss in the AAA and not in sham mice. Immunohistochemistry and Prussian blue staining confirmed the presence of injected macrophages in the AAA. BLI and MRI provide complementary approaches to track macrophage homing and accumulation in experimental AAAs. Similar dual imaging strategies may aid the study of AAA biology and the evaluation of novel therapies.

Miyama N; Dua MM; Schultz GM; Kosuge H; Terashima M; Pisani LJ; Dalman RL; McConnell MV

2012-04-01

72

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

Energy Technology Data Exchange (ETDEWEB)

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

73

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)

[en] 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.

2010-10-08

74

Rapid methods of detecting the target molecule in immunohistology using a bioluminescence probe.  

UK PubMed Central (United Kingdom)

We demonstrate a novel rapid direct detection method for immunohistochemistry, using a bioluminescent probe. An anti-CEA antibody-fused far-red bioluminescent protein can monitor the accumulation of this type of probe in tumour tissues. The bimodal spectrum (?(max) = 460 and 675 nm) of this bioluminescent probe is extremely stable under different conditions of pH and ion concentration. The sensitivity of our bioluminescent labelling was at the same level of enzymatic labelling, e.g. peroxidase, as an indirect system. Our novel technique is simple and can shorten the pretreatment time of paraffin sections to around 30 min. The utility of our bioluminescent labelling covers all imaging in vitro, in vivo and ex vivo, suggesting that our antibody-fused bioluminescent probe has the potential to detect tumour antigens with a high sensitivity in routine immune histological examinations.

Wu C; Wang KY; Guo X; Sato M; Ozaki M; Shimajiri S; Ohmiya Y; Sasaguri Y

2013-01-01

75

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, p<0.001 vs. baseline, p<0.05 vs. sham controls). Histology confirmed substantial macrophage infiltration, with iNOS 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.

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

2011-01-01

76

Making the brain glow: in vivo bioluminescence imaging to study neurodegeneration.  

UK PubMed Central (United Kingdom)

Bioluminescence imaging (BLI) takes advantage of the light-emitting properties of luciferase enzymes, which produce light upon oxidizing a substrate (i.e., D-luciferin) in the presence of molecular oxygen and energy. Photons emitted from living tissues can be detected and quantified by a highly sensitive charge-coupled device camera, enabling the investigator to noninvasively analyze the dynamics of biomolecular reactions in a variety of living model organisms such as transgenic mice. BLI has been used extensively in cancer research, cell transplantation, and for monitoring of infectious diseases, but only recently experimental models have been designed to study processes and pathways in neurological disorders such as Alzheimer disease, Parkinson disease, or amyotrophic lateral sclerosis. In this review, we highlight recent applications of BLI in neuroscience, including transgene expression in the brain, longitudinal studies of neuroinflammatory responses to neurodegeneration and injury, and in vivo imaging studies of neurogenesis and mitochondrial toxicity. Finally, we highlight some new developments of BLI compounds and luciferase substrates with promising potential for in vivo studies of neurological dysfunctions.

Hochgräfe K; Mandelkow EM

2013-06-01

77

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 firef...

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

78

Visualization of mitotic arrest of cell cycle with bioluminescence imaging in living animals.  

UK PubMed Central (United Kingdom)

PURPOSE: Visualization of the cell cycle in living subjects has long been a big challenge. The present study aimed to noninvasively visualize mitotic arrest of the cell cycle with an optical reporter in living subjects. PROCEDURES: An N-terminal cyclin B1-luciferase fusion construct (cyclin B-Luc) controlled by the cyclin B promoter, as a mitosis reporter, was generated. HeLa or HCT116 cells stably expressing cyclin B-Luc reporter were used to evaluate its cell cycle-dependent regulation and ubiquitination-mediated degradation. We also evaluated its feasibility to monitor the mitotic arrest caused by Taxotere both in vitro and in vivo. RESULTS: We showed that the cyclin B-Luc fusion protein was regulated in a cell cycle-dependent manner and accumulated in the mitotic phase (M phase) in cellular assays. The regulation of cyclin B-Luc reporter was mediated by proteasome ubiquitination. In the present study, in vitro imaging showed that antimitotic reagents like Taxotere upregulated the reporter through cell cycle arrest in the M phase. Noninvasive longitudinal bioluminescence imaging further demonstrated an upregulation of the reporter consistent with mitotic arrest induced in tumor xenograft models. Induction of this reporter was also observed with a kinesin spindle protein inhibitor, which causes cell cycle blockage in the M phase. CONCLUSIONS: Our results demonstrate that the cyclin B-Luc reporter can be used to image whether compounds are capable, in vivo, of causing an M phase arrest and/or altering cyclin B turnover. This reporter can also be potentially used in high-throughput screening efforts aimed at discovering novel molecules that will cause cell cycle arrest at the M phase in cultivated cell lines and animal models.

Zhang GJ; Chen TB; Davide J; Tao W; Vanko A; Connolly B; Williams DL Jr; Sur C

2013-08-01

79

Antrodia camphorata suppresses lipopolysaccharide-induced nuclear factor-kappaB activation in transgenic mice evaluated by bioluminescence imaging.  

UK PubMed Central (United Kingdom)

In an earlier study, we found that Antrodia camphorata inhibited the production of lipopolysaccharide (LPS)-induced cytokines, inducible nitric oxide synthase, and cyclooxygenase-2 by blocking nuclear factor-kappaB (NF-kappaB) activation in cultured RAW 264.7 macrophages. This study was aimed at evaluating the inhibitory effects of the fermented culture broth of A. camphorata in terms of LPS-induced NF-kappaB activation in transgenic mice by using a non-invasive, real-time NF-kappaB bioluminescence imaging technique. Transgenic mice carrying the luciferase gene under the control of NF-kappaB were given A. camphorata (570 mg/kg, p.o.) for three consecutive days and then injected with LPS (4 mg/kg, i.p.). In vivo imaging showed that treatment with LPS increased the luminescent signal, whereas A. camphorata suppressed the LPS-induced inflammatory response significantly. Ex vivo imaging showed that A. camphorata suppressed LPS-induced NF-kappaB activity in the small intestine, mesenteric lymph nodes, liver, spleen, and kidney. Immunohistochemical staining revealed that A. camphorata suppressed production of the LPS-induced tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and NF-kappaB p65 subunit in these organs. Furthermore, A. camphorata attenuated the productions of LPS-induced TNF-alpha and IL-1beta in serum from transgenic mice. We report the first confirmation of the anti-inflammatory action in vivo of this potentially beneficial mushroom.

Hseu YC; Huang HC; Hsiang CY

2010-08-01

80

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; Sutherland Caleb; Tawara Ken; Moselhy Jim; Jorcyk Cheryl L

2012-01-01

 
 
 
 
81

Transfection efficiency of normal and cancer cell lines and monitoring of promoter activity by single-cell bioluminescence imaging.  

UK PubMed Central (United Kingdom)

The bioluminescence system (luciferase reporter assay system) is widely used to study gene expression, signal transduction and other cellular activities. Although transfection of reporter plasmid DNA to mammalian cell lines is an indispensable experimental step, the transfection efficiency of DNA varies among cell lines, and several cell lines are not suitable for this type of assay because of the low transfection efficiency. In this study, we confirm the transfection efficiency of reporter DNA to several cancer and normal cell lines after transient transfection by single-cell imaging. Luminescence images could be obtained from living single cells after transient transfection, and the calculated transfection efficiency of this method was similar to that of the conventional reporter assay using a luminometer. We attempted to measure the activity of the Bip promoter under endoplasmic reticulum stress conditions using both high and low transfection efficiency cells for plasmid DNA at the single-cell level, and observed activation of this promoter even in cells with the lowest transfection efficiency. These results show that bioluminescence imaging of single cells is a powerful tool for the analysis of gene expression based on a reporter assay using limited samples such as clinical specimens or cells from primary culture, and could provide additional information compared with the conventional assay. Copyright © 2013 John Wiley & Sons, Ltd.

Horibe T; Torisawa A; Akiyoshi R; Hatta-Ohashi Y; Suzuki H; Kawakami K

2013-03-01

82

In vivo bioluminescence imaging of magnetically targeted bone marrow-derived mesenchymal stem cells in skeletal muscle injury model.  

Science.gov (United States)

The purpose of this study is to clarify the kinetics of transplanted mesenchymal stem cells (MSCs) in rat skeletal muscle injury model and the contribution of the magnetic cell delivery system to muscle injury repair. A magnetic field generator was used to apply an external magnetic force to the injury site of the tibia anterior muscle, and 1?×?10(6) MSCs labeled with ferucarbotran-protamine complexes, which were isolated from luciferase transgenic rats, were injected into the injury site. MSCs were injected with and without an external magnetic force (MSC M+ and MSC M- groups, respectively), and phosphate-buffered saline was injected into injury sites as a control. In vivo bioluminescence imaging was performed immediately after the transplantation and, at 12, 24, and 72?h, and 1 and 4 weeks post-transplantation. Also, muscle regeneration and function were histologically and electromechanically evaluated. In vivo bioluminescence imaging showed that the photon of the MSC M+ group was significantly higher than that of the MSC M- group throughout the observation period. In addition, muscle regeneration and function in the MSC M+ group was histologically and functionally better than that of the MSC M- group. The results of our study indicated that magnetic cell delivery system may be of use in directing the transplanted MSCs to the injury site to promote skeletal muscle regeneration. PMID:23192745

Nakabayashi, Akihiro; Kamei, Naosuke; Sunagawa, Toru; Suzuki, Osami; Ohkawa, Shingo; Kodama, Akira; Kamei, Goki; Ochi, Mitsuo

2012-11-28

83

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

Energy Technology Data Exchange (ETDEWEB)

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

84

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

2011-01-01

85

A non-invasive in vivo imaging system to study dissemination of bioluminescent Yersinia pestis CO92 in a mouse model of pneumonic plague.  

UK PubMed Central (United Kingdom)

The gold standard in microbiology for monitoring bacterial dissemination in infected animals has always been viable plate counts. This method, despite being quantitative, requires sacrificing the infected animals. Recently, however, an alternative method of in vivo imaging of bioluminescent bacteria (IVIBB) for monitoring microbial dissemination within the host has been employed. Yersinia pestis is a Gram-negative bacterium capable of causing bubonic, septicemic, and pneumonic plague. In this study, we compared the conventional counting of bacterial colony forming units (cfu) in the various infected tissues to IVIBB in monitoring Y. pestis dissemination in a mouse model of pneumonic plague. By using a transposon mutagenesis system harboring the luciferase (luc) gene, we screened approximately 4000 clones and obtained a fully virulent, luc-positive Y. pestis CO92 (Y. pestis-luc2) reporter strain in which transposition occurred within the largest pMT1 plasmid which possesses murine toxin and capsular antigen encoding genes. The aforementioned reporter strain and the wild-type CO92 exhibited similar growth curves, formed capsule based on immunofluorescence microscopy and flow cytometry, and had a similar LD(50). Intranasal infection of mice with 15 LD(50) of CO92-luc2 resulted in animal mortality by 72 h, and an increasing number of bioluminescent bacteria were observed in various mouse organs over a 24-72 h period when whole animals were imaged. However, following levofloxacin treatment (10 mg/kg/day) for 6 days 24 h post infection, no luminescence was observed after 72 h of infection, indicating that the tested antimicrobial killed bacteria preventing their detection in host peripheral tissues. Overall, we demonstrated that IVIBB is an effective and non-invasive way of monitoring bacterial dissemination in animals following pneumonic plague having strong correlation with cfu, and our reporter CO92-luc2 strain can be employed as a useful tool to monitor the efficacy of antimicrobial countermeasures in real time.

Sha J; Rosenzweig JA; Kirtley ML; van Lier CJ; Fitts EC; Kozlova EV; Erova TE; Tiner BL; Chopra AK

2013-02-01

86

Improved reconstruction quality of bioluminescent images by combining SP(3) equations and Bregman iteration method.  

UK PubMed Central (United Kingdom)

Bioluminescence tomography (BLT) has a great potential to provide a powerful tool for tumor detection, monitoring tumor therapy progress, and drug development; developing new reconstruction algorithms will advance the technique to practical applications. In the paper, we propose a BLT reconstruction algorithm by combining SP(3) equations and Bregman iteration method to improve the quality of reconstructed sources. The numerical results for homogeneous and heterogeneous phantoms are very encouraging and give significant improvement over the algorithms without the use of SP(3) equations and Bregman iteration method.

Wu Q; Feng J; Jia K; Wang X

2013-01-01

87

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

Science.gov (United States)

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

88

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

89

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

International Nuclear Information System (INIS)

[en] 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-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.)

2004-01-01

90

Dual luciferase labelling for non-invasive bioluminescence imaging of mesenchymal stromal cell chondrogenic differentiation in demineralized bone matrix scaffolds.  

UK PubMed Central (United Kingdom)

Non-invasive bioluminescence imaging (BLI) to monitor changes in gene expression of cells implanted in live animals should facilitate the development of biomaterial scaffolds for tissue regeneration. We show that, in vitro, induction of chondrogenic differentiation in mouse bone marrow stromal cell line (CL1) and human adipose tissue derived mesenchymal stromal cells (hAMSCs), permanently transduced with a procollagen II (COL2A1) promoter driving a firefly luciferase gene reporter (PLuc) (COL2A1p.PLuc), induces PLuc expression in correlation with increases in COL2A1 and Sox9 mRNA expression and acquisition of chondrocytic phenotype. To be able to simultaneously monitor in vivo cell differentiation and proliferation, COL2A1p.PLuc labelled cells were also genetically labelled with a renilla luciferase (RLuc) gene driven by a constitutively active cytomegalovirus promoter, and then seeded in demineralized bone matrix (DBM) subcutaneously implanted in SCID mice. Non-invasive BLI monitoring of the implanted mice showed that the PLuc/RLuc ratio reports on gene expression changes indicative of cell differentiation. Large (CL1) and moderated (hAMSCs) changes in the PLuc/RLuc ratio over a 6 week period, revealed different patterns of in vivo chondrogenic differentiation for the CL1 cell line and primary MSCs, in agreement with in vitro published data and our results from histological analysis of DBM sections. This double bioluminescence labelling strategy together with BLI imaging to analyze behaviour of cells implanted in live animals should facilitate the development of progenitor cell/scaffold combinations for tissue repair.

Vilalta M; Jorgensen C; Dégano IR; Chernajovsky Y; Gould D; Noël D; Andrades JA; Becerra J; Rubio N; Blanco J

2009-10-01

91

[Bioluminescence imaging evaluation of the inhibitory effect of lidamycin on lung metastasis of human fibrosarcoma in athymic mice].  

Science.gov (United States)

This study is to investigate the inhibitory effect of lidamycin (LDM) and its combination with methotrexate (MTX) on lung metastasis of fibrosarcoma by bioluminescence imaging in athymic mice. A stable luciferase transfected HT-1080 cell line was constructed and the capability to establish experimental lung metastasis in athymic mice was confirmed. The optical imaging system was applied to evaluate the formation of lung metastasis in vivo. In addition, metastatic nodules were counted for the evaluation of inhibition rates. As shown, the fluorescent intensity of luciferase-transfected HT-1080 cells was colinear with the cell population and the minimal detected cell population was 100 cells/well. Optical imaging showed that the fluorescent intensity of treated group was apparently lower than that of the control. The inhibition rates of lung metastasis by LDM alone at 0.025 mg x kg(-1) and 0.05 mg x kg(-1) were 53.9% and 75.9%, respectively, while that of MTX alone at 0.5 mg x kg(-1) was 70.2%. The combination of LDM at 0.025 mg x kg(-1) and MTX at 0.5 mg x kg(-1) showed an inhibition rate of 88.7%. The coefficient of drug interaction (CDI) was 0.82. The results herein demonstrated that LDM alone had strong anti-metastasis effect on human fibrosarcoma HT-1080 and the inhibition efficacy is strengthened when combined with MTX. PMID:21465808

Zhang, Sheng-Hua; Zhong, Gen-Shen; He, Hong-Wei; Cheng, Xin; Zhen, Yong-Su

2011-01-01

92

[Bioluminescence imaging evaluation of the inhibitory effect of lidamycin on lung metastasis of human fibrosarcoma in athymic mice].  

UK PubMed Central (United Kingdom)

This study is to investigate the inhibitory effect of lidamycin (LDM) and its combination with methotrexate (MTX) on lung metastasis of fibrosarcoma by bioluminescence imaging in athymic mice. A stable luciferase transfected HT-1080 cell line was constructed and the capability to establish experimental lung metastasis in athymic mice was confirmed. The optical imaging system was applied to evaluate the formation of lung metastasis in vivo. In addition, metastatic nodules were counted for the evaluation of inhibition rates. As shown, the fluorescent intensity of luciferase-transfected HT-1080 cells was colinear with the cell population and the minimal detected cell population was 100 cells/well. Optical imaging showed that the fluorescent intensity of treated group was apparently lower than that of the control. The inhibition rates of lung metastasis by LDM alone at 0.025 mg x kg(-1) and 0.05 mg x kg(-1) were 53.9% and 75.9%, respectively, while that of MTX alone at 0.5 mg x kg(-1) was 70.2%. The combination of LDM at 0.025 mg x kg(-1) and MTX at 0.5 mg x kg(-1) showed an inhibition rate of 88.7%. The coefficient of drug interaction (CDI) was 0.82. The results herein demonstrated that LDM alone had strong anti-metastasis effect on human fibrosarcoma HT-1080 and the inhibition efficacy is strengthened when combined with MTX.

Zhang SH; Zhong GS; He HW; Cheng X; Zhen YS

2011-01-01

93

In vivo bioluminescence imaging validation of a human biopsy-derived orthotopic mouse model of glioblastoma multiforme.  

UK PubMed Central (United Kingdom)

Glioblastoma multiforme (GBM), the most aggressive brain malignancy, is characterized by extensive cellular proliferation, angiogenesis, and single-cell infiltration into the brain. We have previously shown that a xenograft model based on serial xenotransplantation of human biopsy spheroids in immunodeficient rodents maintains the genotype and phenotype of the original patient tumor. The present work further extends this model for optical assessment of tumor engraftment and growth using bioluminescence imaging (BLI). A method for successful lentiviral transduction of the firefly luciferase gene into multicellular spheroids was developed and implemented to generate optically active patient tumor cells. Luciferase-expressing spheroids were injected into the brains of immunodeficient mice. BLI photon counts and tumor volumes from magnetic resonance imaging (MRI) were correlated. Luciferase-expressing tumors recapitulated the histopathologic hallmarks of human GBMs and showed proliferation rates and microvessel density counts similar to those of wild-type xenografts. Moreover, we detected widespread invasion of luciferase-positive tumor cells in the mouse brains. Herein we describe a novel optically active model of GBM that closely mimics human pathology with respect to invasion, angiogenesis, and proliferation indices. The model may thus be routinely used for the assessment of novel anti-GBM therapeutic approaches implementing well-established and cost-effective optical imaging strategies.

Jarzabek MA; Huszthy PC; Skaftnesmo KO; McCormack E; Dicker P; Prehn JH; Bjerkvig R; Byrne AT

2013-05-01

94

Imaging tumor angiogenesis in breast cancer experimental lung metastasis with positron emission tomography, near-infrared fluorescence, and bioluminescence.  

UK PubMed Central (United Kingdom)

The goal of this study was to develop a molecular imaging agent that can allow for both positron emission tomography (PET) and near-infrared fluorescence (NIRF) imaging of CD105 expression in metastatic breast cancer. TRC105, a chimeric anti-CD105 monoclonal antibody, was labeled with both a NIRF dye (i.e., IRDye 800CW) and (64)Cu to yield (64)Cu-NOTA-TRC105-800CW. Flow cytometry analysis revealed no difference in CD105 binding affinity/specificity between TRC105 and NOTA-TRC105-800CW. Serial bioluminescence imaging (BLI) was carried out to non-invasively monitor the lung tumor burden in BALB/c mice, after intravenous injection of firefly luciferase-transfected 4T1 (i.e., fLuc-4T1) murine breast cancer cells to establish the experimental lung metastasis model. Serial PET imaging revealed that fLuc-4T1 lung tumor uptake of (64)Cu-NOTA-TRC105-800CW was 11.9 ± 1.2, 13.9 ± 3.9, and 13.4 ± 2.1 %ID/g at 4, 24, and 48 h post-injection respectively (n = 3). Biodistribution studies, blocking fLuc-4T1 lung tumor uptake with excess TRC105, control experiments with (64)Cu-NOTA-cetuximab-800CW (which served as an isotype-matched control), ex vivo BLI/PET/NIRF imaging, autoradiography, and histology all confirmed CD105 specificity of (64)Cu-NOTA-TRC105-800CW. Successful PET/NIRF imaging of tumor angiogenesis (i.e., CD105 expression) in the breast cancer experimental lung metastasis model warrants further investigation and clinical translation of dual-labeled TRC105-based agents, which can potentially enable early detection of small metastases and image-guided surgery for tumor removal.

Zhang Y; Hong H; Nayak TR; Valdovinos HF; Myklejord DV; Theuer CP; Barnhart TE; Cai W

2013-07-01

95

In vivo visualization and monitoring of viable neural stem cells using noninvasive bioluminescence imaging in the 6-hydroxydopamine-induced mouse model of Parkinson disease.  

UK PubMed Central (United Kingdom)

Transplantation of neural stem cells (NSCs) has been proposed as a treatment for Parkinson disease (PD). The aim of this study was to monitor the viability of transplanted NSCs expressing the enhanced luciferase gene in a mouse model of PD in vivo. The PD animal model was induced by unilateral injection of 6-hydroxydopamine (6-OHDA). The behavioral test using apomorphine-induced rotation and positron emission tomography with [18F]N-(3-fluoropropyl)-2'-carbomethoxy-3'-(4-iodophenyl)nortropane ([18F]FP-CIT) were conducted. HB1.F3 cells transduced with an enhanced firefly luciferase retroviral vector (F3-effLuc cells) were transplanted into the right striatum. In vivo bioluminescence imaging was repeated for 2 weeks. Four weeks after transplantation, [18F]FP-CIT PET and the rotation test were repeated. All 6-OHDA-injected mice showed markedly decreased [18F]FP-CIT uptake in the right striatum. Transplanted F3-effLuc cells were visualized on the right side of the brain in all mice by bioluminescence imaging. The bioluminescence intensity of the transplanted F3-effLuc cells gradually decreased until it was undetectable by 10 days. The behavioral test showed that stem cell transplantation attenuated the motor symptoms of PD. No significant change was found in [18F]FP-CIT imaging after cell transplantation. We successfully established an in vivo bioluminescence imaging system for the detection of transplanted NSCs in a mouse model of PD. NSC transplantation induced behavioral improvement in PD model mice.

Im HJ; Hwang do W; Lee HK; Jang J; Lee S; Youn H; Jin Y; Kim SU; Kim EE; Kim YS; Lee DS

2013-06-01

96

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

97

Effects of Photodynamic Therapy on Gram-Positive and Gram-Negative Bacterial Biofilms by Bioluminescence Imaging and Scanning Electron Microscopic Analysis.  

UK PubMed Central (United Kingdom)

Abstract Objective: The aim of this study was to test photodynamic therapy (PDT) as an alternative approach to biofilm disruption on dental hard tissue, We evaluated the effect of methylene blue and a 660?nm diode laser on the viability and architecture of Gram-positive and Gram-negative bacterial biofilms. Materials and methods: Ten human teeth were inoculated with bioluminescent Pseudomonas aeruginosa or Enterococcus faecalis to form 3 day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify and evaluate the bacterial viability, and scanning electron microscopic (SEM) imaging was used to assess architecture and morphology of bacterial biofilm before and after PDT employing methylene blue and 40?mW, 660?nm diode laser light delivered into the root canal via a 300??m fiber for 240?sec, resulting in a total energy of 9.6?J. The data were statistically analyzed with analysis of variance (ANOVA) followed by Tukey test. Results: The bacterial reduction showed a dose dependence; as the light energy increased, the bioluminescence decreased in both planktonic suspension and in biofilms. The SEM analysis showed a significant reduction of biofilm on the surface. PDT promoted disruption of the biofilm and the number of adherent bacteria was reduced. Conclusions: The photodynamic effect seems to disrupt the biofilm by acting both on bacterial cells and on the extracellular matrix.

Garcez AS; Núñez SC; Azambuja N Jr; Fregnani ER; Rodriguez HM; Hamblin MR; Suzuki H; Ribeiro MS

2013-07-01

98

Real-time luminescence imaging of cellular ATP release.  

UK PubMed Central (United Kingdom)

Extracellular ATP and other purines are ubiquitous mediators of local intercellular signaling within the body. While the last two decades have witnessed enormous progress in uncovering and characterizing purinergic receptors and extracellular enzymes controlling purinergic signals, our understanding of the initiating step in this cascade, i.e., ATP release, is still obscure. Imaging of extracellular ATP by luciferin-luciferase bioluminescence offers the advantage of studying ATP release and distribution dynamics in real time. However, low-light signal generated by bioluminescence reactions remains the major obstacle to imaging such rapid processes, imposing substantial constraints on its spatial and temporal resolution. We have developed an improved microscopy system for real-time ATP imaging, which detects ATP-dependent luciferin-luciferase luminescence at ?10 frames/s, sufficient to follow rapid ATP release with sensitivity of ?10 nM and dynamic range up to 100?M. In addition, simultaneous differential interference contrast cell images are acquired with infra-red optics. Our imaging method: (1) identifies ATP-releasing cells or sites, (2) determines absolute ATP concentration and its spreading manner at release sites, and (3) permits analysis of ATP release kinetics from single cells. We provide instrumental details of our approach and give several examples of ATP-release imaging at cellular and tissue levels, to illustrate its potential utility.

Furuya K; Sokabe M; Grygorczyk R

2013-08-01

99

Real-time bioluminescent assay for inhibitors of RNA and DNA polymerases and other ATP-dependent enzymes.  

UK PubMed Central (United Kingdom)

Viral polymerases are important targets for drug development. However, current methods used to identify and characterize inhibitors of polymerases are time-consuming, use radiolabeled reagents, and are cost-inefficient. Here we present a bioluminescent assay for the identification and characterization of inhibitors of polymerases, as well as other ATP-dependent enzymes, that monitors the decrease of ATP or dATP in real time, allowing detection of enzyme inhibition based on differences in ATP/dATP consumption. The assay works with a variety of RNA and DNA polymerases, using both RNA and DNA templates. The assay measures changes in substrate concentration in real time and provides a faster alternative for kinetic studies of inhibition. Michaelis-Menten plots were obtained from a single reaction, yielding K(m) values that compared well with literature values. The assay could identify the mechanism of inhibition and determine inhibition constants (K(i)) for a weak competitive inhibitor of Klenow fragment and two strong noncompetitive inhibitors of HIV-1 reverse transcriptase with one series of inhibitor concentrations, reducing the total number of experiments that would normally be needed. The assay is also sensitive enough to detect a weak inhibitor with K(i)>100 ?M, making it a viable technique for fragment-based drug discovery.

Gregory KJ; Sun Y; Chen NG; Golovlev V

2011-01-01

100

Real-time bioluminescent assay for inhibitors of RNA and DNA polymerases and other ATP-dependent enzymes.  

Science.gov (United States)

Viral polymerases are important targets for drug development. However, current methods used to identify and characterize inhibitors of polymerases are time-consuming, use radiolabeled reagents, and are cost-inefficient. Here we present a bioluminescent assay for the identification and characterization of inhibitors of polymerases, as well as other ATP-dependent enzymes, that monitors the decrease of ATP or dATP in real time, allowing detection of enzyme inhibition based on differences in ATP/dATP consumption. The assay works with a variety of RNA and DNA polymerases, using both RNA and DNA templates. The assay measures changes in substrate concentration in real time and provides a faster alternative for kinetic studies of inhibition. Michaelis-Menten plots were obtained from a single reaction, yielding K(m) values that compared well with literature values. The assay could identify the mechanism of inhibition and determine inhibition constants (K(i)) for a weak competitive inhibitor of Klenow fragment and two strong noncompetitive inhibitors of HIV-1 reverse transcriptase with one series of inhibitor concentrations, reducing the total number of experiments that would normally be needed. The assay is also sensitive enough to detect a weak inhibitor with K(i)>100 ?M, making it a viable technique for fragment-based drug discovery. PMID:20727342

Gregory, Kalvin J; Sun, Ye; Chen, Nelson G; Golovlev, Valeri

2010-08-18

 
 
 
 
101

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

Directory of Open Access Journals (Sweden)

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.

Zabala Maider; Alzuguren Pilar; Benavides Carolina; Crettaz Julien; Gonzalez-Aseguinolaza Gloria; Ortiz de Solorzano Carlos; Gonzalez-Aparicio Manuela; Kramer Maria; Prieto Jesus; Hernandez-Alcoceba Ruben

2009-01-01

102

Cyclophosphamide increases transgene expression mediated by an oncolytic adenovirus in glioma-bearing mice monitored by bioluminescence imaging.  

Science.gov (United States)

Approaches to improve the oncolytic potency of replication-competent adenoviruses include the insertion of therapeutic transgenes into the viral genome. Little is known about the levels and duration of in vivo transgene expression by cells infected with such "armed" viruses. Using a tumor-selective adenovirus encoding firefly luciferase (AdDelta24CMV-Luc) we investigated these questions in an intracranial mouse model for malignant glioma. Luciferase expression was detected by bioluminescence imaging, and the effect of the immunosuppressive agent cyclophosphamide (CPA) on transgene expression was assessed. Intratumoral AdDelta24CMV-Luc injection led to a localized dose-dependent expression of luciferase. Surprisingly, this expression decreased rapidly during the course of 14 days. In contrast, mice injected with nonreplicating Ad.CMV-Luc demonstrated stable transgene expression. Treatment of mice with CPA in combination with AdDelta24CMV-Luc retarded the loss of transgene expression. Staining of mouse brains for inflammatory cells demonstrated decreased tumor infiltration by immune cells in CPA-treated mice. Moreover, in immunodeficient NOD/SCID mice loss of transgene expression was less rapid and not prevented by CPA treatment. Together, our data demonstrate that transgene expression and viral replication decrease rapidly after intratumoral injection of oncolytic adenovirus in mouse brains and that treatment with the immunomodulator CPA prolongs viral-mediated gene expression. PMID:16996314

Lamfers, Martine L M; Fulci, Giulia; Gianni, Davide; Tang, Yi; Kurozumi, Kazuhiko; Kaur, Balveen; Moeniralm, Sharif; Saeki, Yoshinaga; Carette, Jan E; Weissleder, Ralph; Vandertop, W Peter; van Beusechem, Victor W; Dirven, Clemens M F; Chiocca, E Antonio

2006-09-22

103

Biodistribution, long-term survival, and safety of human adipose tissue-derived mesenchymal stem cells transplanted in nude mice by high sensitivity non-invasive bioluminescence imaging.  

UK PubMed Central (United Kingdom)

Cultivated murine bone marrow mesenchymal stem cells (MSCs) frequently accumulate chromosome abnormalities, become oncogenically transformed, and generate sarcomas when transplanted in mice. Although human MSCs appear to be more resistant, oncogenic transformation has also been observed in MSCs cultivated past the senescence phase. Cell therapy for tissue regeneration using human autologous MSCs requires transplantation of cells previously expanded in vitro. Thus, an important concern is to determine if oncogenic transformation is a necessary outcome of the expansion procedures. We have analyzed the proliferation capacity, organ colonization, and oncogenicity of enhanced green fluorescent protein and luciferase-labeled human adipose tissue-derived mesenchymal stem cells (hAMSCs), implanted in immunocompromised mice during a prolonged time period (8 months) using a non-invasive bioluminescence imaging procedure. Our data indicates that the liver was the preferred target organ for colonization by intramuscular or intravenous implantation of hAMSCs. The implanted cells tended to maintain a steady state, population did not proliferate rapidly after implantation, and no detectable chromosomal abnormalities nor tumors formed during the 8 months of residence in the host's tissues. It would appear that hAMSCs, contrary to their murine correlatives, could be safe candidates for autologous cell therapy procedures since in our experiments they show undetectable predisposition to oncogenic transformation after cultivation in vitro and implantation in mice.

Vilalta M; Dégano IR; Bagó J; Gould D; Santos M; García-Arranz M; Ayats R; Fuster C; Chernajovsky Y; García-Olmo D; Rubio N; Blanco J

2008-10-01

104

Bioluminescence imaging to study the promoter activity of hla of Staphylococcus aureus in vitro and in vivo.  

Science.gov (United States)

Alpha-toxin (Hla, encoded by hla) is a major virulence factor of Staphylococcus aureus. The activity of the hla promoter was analyzed using luxABCDE on an integration vector. The phla-lux construct was introduced in S. aureus Newman and its isogenic sae and sigB regulator mutants. Promoter activity was monitored by bioluminescence in vitro and in the murine tissue-cage model. Hla promoter activity could be followed in real time at repeated time points of infection. The activation of hla in the sigB-deficient strain and the repression to background levels in a sae-deficient strain relative to hla expression in the wild type could be demonstrated in vivo. Subinhibitory concentrations of teicoplanin, imipenem and ciprofloxacin enhanced hla promoter activity in vitro whereas clindamycin and rifampicin did not. Our approach proved to be rapid and adequate to study promoter activity in vitro and in vivo under conditions where high bacterial numbers are reached. PMID:18329335

Steinhuber, Andrea; Landmann, Regine; Goerke, Christiane; Wolz, Christiane; Flückiger, Ursula

2008-03-07

105

[Influence of MSA on cell growth and spontaneousn metastasis of L9981-Luc lung cancer transplanted model in nude mice by bioluminescence imaging].  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Methylseleninic acid (MSA) is an artificially developed selenium compound. It has been proven that MSA could inhibit growth and metastasis on many tumor cells. This study investigated whether MSA has an impact on the growth and metastasis of L9981-Luc lung cancer transplanted model in nude mice or not. METHODS: A transplantated tumor model was established in nude mice. Fifteen nude mice were randomly divided into three groups: the control group treated with normal saline (0.2 mL/d), the MSA group treated with MSA solution (0.2 mL), and the cisplatin (DDP) group injected intraperitoneally with DDP (4 mg/kg/w). Inhibition of MSA on tumor growth and tumor metastasis was observed using the IVIS Imaging System 200 Series. RESULTS: A significant difference was obserced in the primary tumor bioluminescence among the three groups (P=0.002) on 21 days post-inoculation. Primary tumor bioluminescence in the DDP group (P=0.001) and in the MSA group (P=0.031) was significantly lower than that in the control group (P=0.001). No significant difference in the metastasis bioluminescence of the thoracic area was indicated among the three groups (P>0.05). CONCLUSIONS: MSA can inhibit the growth of planted tumor of transgenic lung cancer cell lines L9981-Luc in nude mice. MSA may also suppress the distant metastasis of the transplanted tumor of transgenic lung cancer cell lines L9981-Luc in nude mice.

Ren Y; Wang Y; Liu H; Yan H; Chen J; Hou M; Li W; Fan Y; Zhou Q

2013-02-01

106

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

UK PubMed Central (United Kingdom)

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 G; Hardinge P; Buttigieg N; Gandelman O; Pereira C; McElgunn CJ; Rizzoli M; Jackson R; Appleton N; Moore C; Tisi LC; Murray JA

2012-01-01

107

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

2012-01-01

108

Stress-resistant bioluminescent dinoflagellates  

UK PubMed Central (United Kingdom)

A tough mutant strain of the bioluminescent marine dinoflagellate pyrocystis lunula which produces almost three times more light than its predecessor Pyrocystis lunula strain, which can withstand much more centrifugal force than its predecessor, and which grows faster than its predecessor in a defined medium under laboratory conditions, doubling about every four days, and requiring only monthly transfers.

STIFFEY ARTHUR V

109

Influence of MSA on Cell Growth and Spontaneousn Metastasis of L9981-Luc Lung Cancer Transplanted Model in Nude Mice by Bioluminescence Imaging  

Directory of Open Access Journals (Sweden)

Full Text Available Background and objective Methylseleninic acid (MSA) is an artificially developed selenium compound. It has been proven that MSA could inhibit growth and metastasis on many tumor cells. This study investigated whether MSA has an impact on the growth and metastasis of L9981-Luc lung cancer transplanted model in nude mice or not. Methods A transplantated tumor model was established in nude mice. Fifteen nude mice were randomly divided into three groups: the control group treated with normal saline (0.2 mL/d), the MSA group treated with MSA solution (0.2 mL), and the cisplatin (DDP) group injected intraperitoneally with DDP (4 mg/kg/w). Inhibition of MSA on tumor growth and tumor metastasis was observed using the IVIS Imaging System 200 Series. Results A significant difference was obserced in the primary tumor bioluminescence among the three groups (P=0.002) on 21 days post-inoculation. Primary tumor bioluminescence in the DDP group (P=0.001) and in the MSA group (P=0.031) was significantly lower than that in the control group (P=0.001). No significant difference in the metastasis bioluminescence of the thoracic area was indicated among the three groups (P>0.05). Conclusion MSA can inhibit the growth of planted tumor of transgenic lung cancer cell lines L9981-Luc in nude mice. MSA may also suppress the distant metastasis of the transplanted tumor of transgenic lung cancer cell lines L9981-Luc in nude mice.

Yuanrong REN; Yuli WANG; Hongyu LIU; Huiqin YAN; Jun CHEN; Mei HOU; Weimin LI; Yaguang FAN; Qinghua ZHOU

2013-01-01

110

Molecular bioluminescence imaging as a noninvasive tool for monitoring tumor growth and therapeutic response to MRI-guided laser ablation in a rat model of hepatocellular carcinoma.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The objective of this study was to quantitatively compare tumor imaging by magnetic resonance imaging (MRI) and molecular bioluminescence imaging (BLI) and test the feasibility of monitoring the effect of MRI-guided laser ablation on tumor viability by 2-dimensional BLI and 3-dimensional diffuse luminescence tomography (3D DLIT) in an orthotopic rat model of hepatocellular carcinoma. MATERIALS AND METHODS: This study was approved by the animal care committee. Rats underwent injection of N1S1 cells stably transfected with an empty vector (n = 3) or a heat shock element luciferase reporter (HSE-luc; n = 4) into the liver. All rats underwent MRI to assess tumor establishment and volume and 2-dimensional BLI to assess tumor luminescence at day 7 with subsequent MRI and 2D BLI and 3D DLIT in select animals at days 14 and 21. Magnetic resonance imaging-guided laser ablation of the tumor was performed with preablation and postablation 2D BLI and/or 3D DLIT (n = 2). The tumors underwent histopathologic analysis to assess tumor viability. RESULTS: The MRI scans demonstrated hyperintense T2-weighted lesions at 3 of 3 and 4 of 4 sites in the empty vector and HSE-luc rats, respectively. Two-dimensional BLI quantitation demonstrated 23.0-fold higher radiance in the HSE-luc group compared with the empty vector group at day 7 (P < 0.01) and a significant correlation with tumor volume by MRI (r = 0.86; P < 0.03). Tumor dimensions by 3D DLIT and MRI demonstrated good agreement. Three-dimensional DLIT quantitation demonstrated better agreement with thepercentage of nonviable tumor by histopathology than did 2D BLI quantitation after the MRI-guided laser ablation. CONCLUSIONS: Bioluminescence imaging is feasible as a noninvasive, quantitative tool for monitoring tumor growth and therapeutic response to thermal ablation in a rat model of hepatocellular carcinoma.

Thompson SM; Callstrom MR; Knudsen BE; Anderson JL; Sutor SL; Butters KA; Kuo C; Grande JP; Roberts LR; Woodrum DA

2013-06-01

111

Fungi bioluminescence revisited.  

Science.gov (United States)

A review of the research conducted during the past 30 years on the distribution, taxonomy, phylogeny, ecology, physiology and bioluminescence mechanisms of luminescent fungi is presented. We recognize 64 species of bioluminescent fungi belonging to at least three distinct evolutionary lineages, termed Omphalotus, Armillaria and mycenoid. An accounting of their currently accepted names, distributions, citations reporting luminescence and whether their mycelium and/or basidiomes emit light are provided. We address the physiological and ecological aspects of fungal bioluminescence and provide data on the mechanisms responsible for bioluminescence in the fungi. PMID:18264584

Desjardin, Dennis E; Oliveira, Anderson G; Stevani, Cassius V

2008-01-24

112

High-throughput detection of spore contamination in food packages and food powders using tiered approach of ATP bioluminescence and real-time PCR  

UK PubMed Central (United Kingdom)

A rapid and quantitative method for detection of Bacillus spores in food/non-alcoholic beverage packages and food powders has been developed using filtration-based ATP bioluminescence and real-time PCR, targeting the sporulation gene (spo0A). In combination with heat activation, the presence and amount of viable bacterial spores (i.e., Bacillus amyloliquefaciens, Bacillus licheniformis, and Bacillus thuringiensis) was determined within 20 min through ATP signal amplifications. The detection limits of heat activation-ATP bioluminescence assay for B. amyloliquefaciens and B. licheniformis spores on food packages were 1.4 × 102 and 1.0 × 103 CFU/cm2, respectively. In contaminated food powders, B. thuringiensis spores could be detected by the ATP assay within the range of 7.9 × 100 to 3.2 × 104 CFU/mg powder while the PCR detection limit was 614 CFU/mg. Linear relationships between luminescent signal (RLU/mg) and plate count (CFU/mg) were found. The same sample after heat activation-ATP assay could be directly used for real-time PCR as a streamlined detection to confirm the identity of Bacillus spores in food packages and food powders even though some bacterial DNA loss was observed. This tiered approach, filtration-based one-tube ATP luminescence method as a rapid, viable screening and using real-time PCR as confirmation, could serve as a high-throughput tool for the detection of Bacillus spores in the food and beverage industry.

Ratphitagsanti W; Park E; Lee CS; Amos Wu RY; Lee J

2012-04-01

113

Genipin inhibits lipopolysaccharide-induced acute systemic inflammation in mice as evidenced by nuclear factor-?B bioluminescent imaging-guided transcriptomic analysis.  

UK PubMed Central (United Kingdom)

Genipin is a natural blue colorant in food industry. Inflammation is correlated with human disorders, and nuclear factor-?B (NF-?B) is the critical molecule involved in inflammation. In this study, the anti-inflammatory effect of genipin on the lipopolysaccharide (LPS)-induced acute systemic inflammation in mice was evaluated by NF-?B bioluminescence-guided transcriptomic analysis. Transgenic mice carrying the NF-?B-driven luciferase genes were administered intraperitoneally with LPS and various amounts of genipin. Bioluminescent imaging showed that genipin significantly suppressed LPS-induced NF-?B-dependent luminescence in vivo. The suppression of LPS-induced acute inflammation by genipin was further evidenced by the reductions of cytokine levels in sera and organs. Microarray analysis of these organs showed that the transcripts of 79 genes were differentially expressed in both LPS and LPS/genipin groups, and one third of these genes belonged to chemokine ligand, chemokine receptor, and interferon (IFN)-induced protein genes. Moreover, network analysis showed that NF-?B played a critical role in the regulation of genipin-affected gene expression. In conclusion, we newly identified that genipin exhibited anti-inflammatory effects in a model of LPS-induced acute systemic inflammation via downregulation of chemokine ligand, chemokine receptor, and IFN-induced protein productions.

Li CC; Hsiang CY; Lo HY; Pai FT; Wu SL; Ho TY

2012-09-01

114

Strategy for dual-analyte luciferin imaging: in vivo bioluminescence detection of hydrogen peroxide and caspase activity in a murine model of acute inflammation.  

Science.gov (United States)

In vivo molecular imaging holds promise for understanding the underlying mechanisms of health, injury, aging, and disease, as it can detect distinct biochemical processes such as enzymatic activity, reactive small-molecule fluxes, or post-translational modifications. Current imaging techniques often detect only a single biochemical process, but, within whole organisms, multiple types of biochemical events contribute to physiological and pathological phenotypes. In this report, we present a general strategy for dual-analyte detection in living animals that employs in situ formation of firefly luciferin from two complementary caged precursors that can be unmasked by different biochemical processes. To establish this approach, we have developed Peroxy Caged Luciferin-2 (PCL-2), a H(2)O(2)-responsive boronic acid probe that releases 6-hydroxy-2-cyanobenzothiazole (HCBT) upon reacting with this reactive oxygen species, as well as a peptide-based probe, z-Ile-Glu-ThrAsp-D-Cys (IETDC), which releases D-cysteine in the presence of active caspase 8. Once released, HCBT and D-cysteine form firefly luciferin in situ, giving rise to a bioluminescent signal if and only if both chemical triggers proceed. This system thus constitutes an AND-type molecular logic gate that reports on the simultaneous presence of H(2)O(2) and caspase 8 activity. Using these probes, chemoselective imaging of either H(2)O(2) or caspase 8 activity was performed in vitro and in vivo. Moreover, concomitant use of PCL-2 and IETDC in vivo establishes a concurrent increase in both H(2)O(2) and caspase 8 activity during acute inflammation in living mice. Taken together, this method offers a potentially powerful new chemical tool for studying simultaneous oxidative stress and inflammation processes in living animals during injury, aging, and disease, as well as a versatile approach for concurrent monitoring of multiple analytes using luciferin-based bioluminescence imaging technologies. PMID:23347279

Van de Bittner, Genevieve C; Bertozzi, Carolyn R; Chang, Christopher J

2013-01-25

115

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

Directory of Open Access Journals (Sweden)

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.

Cong Wenxiang; Wang Lihong V; Wang Ge

2004-01-01

116

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

UK PubMed Central (United Kingdom)

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.

Tiffen JC; Bailey CG; Ng C; Rasko JE; Holst J

2010-01-01

117

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

Science.gov (United States)

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. PMID:21092230

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

2010-11-22

118

In vivo functional calcium imaging of induced or spontaneous activity in the fly brain using a GFP-apoaequorin-based bioluminescent approach.  

UK PubMed Central (United Kingdom)

Different optical imaging techniques have been developed to study neuronal activity with the goal of deciphering the neural code underlying neurophysiological functions. Because of several constraints inherent in these techniques as well as difficulties interpreting the results, the majority of these studies have been dedicated more to sensory modalities than to the spontaneous activity of the central brain. Recently, a novel bioluminescence approach based on GFP-aequorin (GA) (GFP: Green fluorescent Protein), has been developed, allowing us to functionally record in-vivo neuronal activity. Taking advantage of the particular characteristics of GA, which does not require light excitation, we report that we can record induced and/or the spontaneous Ca(2+)-activity continuously over long periods. Targeting GA to the mushrooms-bodies (MBs), a structure implicated in learning/memory and sleep, we have shown that GA is sensitive enough to detect odor-induced Ca(2+)-activity in Kenyon cells (KCs). It has been possible to reveal two particular peaks of spontaneous activity during overnight recording in the MBs. Other peaks of spontaneous activity have been recorded in flies expressing GA pan-neurally. Similarly, expression in the glial cells has revealed that these cells exhibit a cell-autonomous Ca(2+)-activity. These results demonstrate that bioluminescence imaging is a useful tool for studying Ca(2+)-activity in neuronal and/or glial cells and for functional mapping of the neurophysiological processes in the fly brain. These findings provide a framework for investigating the biological meaning of spontaneous neuronal activity. This article is part of a Special Issue entitled: 12th European Symposium on Calcium.

Minocci D; Carbognin E; Murmu MS; Martin JR

2013-07-01

119

A new liposomal formulation of Gemcitabine is active in an orthotopic mouse model of pancreatic cancer accessible to bioluminescence imaging.  

Science.gov (United States)

Despite its rapid enzymatic inactivation and therefore limited activity in vivo, Gemcitabine is the standard drug for pancreatic cancer treatment. To protect the drug, and achieve passive tumor targeting, we developed a liposomal formulation of Gemcitabine, GemLip (Ø: 36 nm: 47% entrapment). Its anti-tumoral activity was tested on MIA PaCa-2 cells growing orthotopically in nude mice. Bioluminescence measurement mediated by the stable integration of the luciferase gene was employed to randomize the mice, and monitor tumor growth. GemLip (4 and 8 mg/kg), Gemcitabine (240 mg/kg), and empty liposomes (equivalent to 8 mg/kg GemLip) were injected intravenously once weekly for 5 weeks. GemLip (8 mg/kg) stopped tumor growth, as measured via in vivo bioluminescence, reducing the primary tumor size by 68% (SD +/- 8%; p < 0.02), whereas Gemcitabine hardly affected tumor size (-7%; +/- 1.5%). In 80% of animals, luciferase activity in the liver indicated the presence of metastases. All treatments, including the empty liposomes, reduced the metastatic burden. Thus, GemLip shows promising antitumoral activity in this model. Surprisingly, empty liposomes attenuate the spread of metastases similar to Gemcitabine and GemLip. Further, luciferase marked tumor cells are a powerful tool to observe tumor growth in vivo, and to detect and quantify metastases. PMID:17554540

Bornmann, C; Graeser, R; Esser, N; Ziroli, V; Jantscheff, P; Keck, T; Unger, C; Hopt, U T; Adam, U; Schaechtele, C; Massing, U; von Dobschuetz, E

2007-06-07

120

Hydromechanical stimulation of bioluminescent plankton.  

Science.gov (United States)

The response of the bioluminescent dinoflagellate Pyrocystis fusiformis was investigated for different hydraulic conditions ('hydromechanical stimulation'). Pipe flow and oscillating shear produced luminescence, whereas changes in hydrostatic pressure were not stimulating. More intense fluid motion led to higher intensity, mainly due to a higher probability of cell response. The organism was also able to emit light in a glucose-salt mixture. The experiments suggest that the cells are effectively stimulated if the flow conditions change in time. PMID:12444590

Blaser, Stefan; Kurisu, Futoshi; Satoh, Hiroyasu; Mino, Takashi

 
 
 
 
121

Hydromechanical stimulation of bioluminescent plankton.  

UK PubMed Central (United Kingdom)

The response of the bioluminescent dinoflagellate Pyrocystis fusiformis was investigated for different hydraulic conditions ('hydromechanical stimulation'). Pipe flow and oscillating shear produced luminescence, whereas changes in hydrostatic pressure were not stimulating. More intense fluid motion led to higher intensity, mainly due to a higher probability of cell response. The organism was also able to emit light in a glucose-salt mixture. The experiments suggest that the cells are effectively stimulated if the flow conditions change in time.

Blaser S; Kurisu F; Satoh H; Mino T

2002-11-01

122

Stimulated bioluminescence by fluid shear stress associated with pipe flow  

International Nuclear Information System (INIS)

[en] 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.

2011-01-01

123

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

124

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

125

Space-time compressive imaging.  

UK PubMed Central (United Kingdom)

Compressive imaging systems typically exploit the spatial correlation of the scene to facilitate a lower dimensional measurement relative to a conventional imaging system. In natural time-varying scenes there is a high degree of temporal correlation that may also be exploited to further reduce the number of measurements. In this work we analyze space-time compressive imaging using Karhunen-Loève (KL) projections for the read-noise-limited measurement case. Based on a comprehensive simulation study, we show that a KL-based space-time compressive imager offers higher compression relative to space-only compressive imaging. For a relative noise strength of 10% and reconstruction error of 10%, we find that space-time compressive imaging with 8×8×16 spatiotemporal blocks yields about 292× compression compared to a conventional imager, while space-only compressive imaging provides only 32× compression. Additionally, under high read-noise conditions, a space-time compressive imaging system yields lower reconstruction error than a conventional imaging system due to the multiplexing advantage. We also discuss three electro-optic space-time compressive imaging architecture classes, including charge-domain processing by a smart focal plane array (FPA). Space-time compressive imaging using a smart FPA provides an alternative method to capture the nonredundant portions of time-varying scenes.

Treeaporn V; Ashok A; Neifeld MA

2012-02-01

126

Microbiological assay using bioluminescent organism  

Energy Technology Data Exchange (ETDEWEB)

This invention relates to testing processes for toxicity involving microorganisms and, more particularly, to testing processes for toxicity involving bioluminescent organisms. The present known method of testing oil-well drilling fluids for toxicity employs the mysid shrimp (Mysidopsis bahia) as the assay organism. The shrimp are difficult to raise and handle as laboratory assay organisms. This method is labor-intensive, because it requires a assay time of about 96 hours. Summary of the Invention: A microbiological assay in which the assay organism is the dinoflagellate, Pyrocystis lunula. A sample of a substance to be assayed is added to known numbers of the bioluminescent dinoflagellate and the mixture is agitated to subject the organisms to a shear stress causing them to emit light. The amount of light emitted is measured and compared with the amount of light emitted by a known non-toxic control mixture to determine if there is diminution or non-diminution of light emitted by the sample under test which is an indication of the presence or absence of toxicity, respectively. Accordingly, an object of the present invention is the provision of an improved method of testing substances for toxicity. A further object of the invention is the provision of an improved method of testing oil-well drilling fluids for toxicity using bioluminescent dinoflagellate (Pyrocystis lunula).

Stiffey, A.V.

1987-12-21

127

Bioluminescence tomography with Gaussian prior  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Parameterizing the bioluminescent source globally in Gaussians provides several advantages over voxel representation in bioluminescence tomography. It is mathematically unique to recover Gaussians [Med. Phys. 31(8), 2289 (2004)] and practically sufficient to approximate various shapes by Gaussians i...

Gao, Hao; Zhao, Hongkai; Cong, Wenxiang; Wang, Ge

128

Toona sinensis and its major bioactive compound gallic acid inhibit LPS-induced inflammation in nuclear factor-?B transgenic mice as evaluated by in vivo bioluminescence imaging.  

UK PubMed Central (United Kingdom)

In the present study, we investigated the anti-inflammatory effects of a nutritious vegetable Toona sinensis (leaf extracts, TS) and its major bioactive compound gallic acid (GA) by analysing LPS-induced NF-?B activation in transgenic mice, using bioluminescence imaging. Mice were challenged intraperitoneally with LPS (1mg/kg) and treated orally with TS or GA (100 or 5mg/kg, respectively). In vivo and ex vivo imaging showed that LPS increased NF-?B luminescence in the abdominal region, which was significantly inhibited by TS or GA. Immunohistochemical and ELISA analyses confirmed that TS and GA inhibited LPS-induced NF-?B, interleukin-1?, and tumour necrosis factor-? expression. Microarray analysis revealed that biological pathways associated with metabolism and the immune responses were affected by TS or GA. Particularly, LPS-induced thioredoxin-like 4B (TXNL4B) 2 expression in the small intestine, and TXNL4B, iNOS, and COX-2 expression in RAW 264.7 cells were significantly inhibited by TS or GA. Thus, the anti-inflammatory potential of TS was mediated by the downregulation of NF-?B pathway.

Hsiang CY; Hseu YC; Chang YC; Kumar KJ; Ho TY; Yang HL

2013-01-01

129

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

130

Gombrich on image and time  

Directory of Open Access Journals (Sweden)

Full Text Available There is a very close, indeed intrinsic, connection between the notions of image and time. Images are incomplete unless they are moving ones – unless, that is, they happen in time. On the other hand, time cannot be conceptualized except by metaphors, and so ultimately by images, of movement in space. That only the moving image is a full-fledged one is a fact that was fully recognized and articulated by Ernst Gombrich. Also, Gombrich entertained, and argued for, a rich and well-balanced view of the relationships between pictorial and verbal representation. An antidote to the unholy influence of Goodman, Gombrich deserves to be rediscovered as the figure whose work is ideally suited to providing a founding paradigm for a truly successful philosophy of images.

Kristóf Nyíri

2009-01-01

131

Bioluminescent bioreporter integrated circuit  

Energy Technology Data Exchange (ETDEWEB)

Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

Simpson, Michael L. (Knoxville, TN); Sayler, Gary S. (Blaine, TN); Paulus, Michael J. (Knoxville, TN)

2000-01-01

132

In vivo bioluminescence reporter gene imaging for the activation of neuronal differentiation induced by the neuronal activator neurogenin 1 (Ngn1) in neuronal precursor cells.  

UK PubMed Central (United Kingdom)

PURPOSE: Facilitation of the ability of neuronal lineages derived from transplanted stem cells to differentiate is essential to improve the low efficacy of neuronal differentiation in stem cell therapy in vivo. Neurogenin 1 (Ngn1), a basic helix-loop-helix factor, has been used as an activator of neuronal differentiation. In this study, we monitored the in vivo activation of neuronal differentiation by Ngn1 in neuronal precursor cells using neuron-specific promoter-based optical reporters. METHODS: The NeuroD promoter coupled with the firefly luciferase reporter system (pNeuroD-Fluc) was used to monitor differentiation in F11 neuronal precursor cells. In vitro luciferase activity was measured and normalized by protein content. The in vivo-jetPEI(TM) system was used for in vivo transgene delivery. The IVIS 100 imaging system was used to monitor in vivo luciferase activity. RESULTS: The Ngn1-induced neuronal differentiation of F11 cells generated neurite outgrowth within 2 days of Ngn1 induction. Immunofluorescence staining demonstrated that early and late neuronal marker expression (?III-tubulin, NeuroD, MAP2, NF-M, and NeuN) was significantly increased at 3 days after treatment with Ngn1. When Ngn1 and the pNeuroD-Fluc vector were cotransfected into F11 cells, we observed an approximately 11-fold increase in the luciferase signal. An in vivo study showed that bioluminescence signals were gradually increased in Ngn1-treated F11 cells for up to 3 days. CONCLUSION: In this study, we examined the in vivo tracking of neuronal differentiation induced by Ngn1 using an optical reporter system. This reporter system could be used effectively to monitor the activation efficiency of neuronal differentiation in grafted stem cells treated with Ngn1 for stem cell therapy.

Oh HJ; Hwang do W; Youn H; Lee DS

2013-10-01

133

In vivo bioluminescent imaging of influenza a virus infection and characterization of novel cross-protective monoclonal antibodies.  

UK PubMed Central (United Kingdom)

Influenza A virus is a major human pathogen responsible for seasonal epidemics as well as pandemic outbreaks. Due to the continuing burden on human health, the need for new tools to study influenza virus pathogenesis as well as to evaluate new therapeutics is paramount. We report the development of a stable, replication-competent luciferase reporter influenza A virus that can be used for in vivo imaging of viral replication. This imaging is noninvasive and allows for the longitudinal monitoring of infection in living animals. We used this tool to characterize novel monoclonal antibodies that bind the conserved stalk domain of the viral hemagglutinin of H1 and H5 subtypes and protect mice from lethal disease. The use of luciferase reporter influenza viruses allows for new mechanistic studies to expand our knowledge of virus-induced disease and provides a new quantitative method to evaluate future antiviral therapies.

Heaton NS; Leyva-Grado VH; Tan GS; Eggink D; Hai R; Palese P

2013-08-01

134

Bioluminescent imaging reveals divergent viral pathogenesis in two strains of Stat1-deficient mice, and in ?ß? interferon receptor-deficient mice.  

Science.gov (United States)

Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1(-/-) and IFN?ß?R(-/-) mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1(-/-) mice and in IFN?ß?R(-/-) mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1(-/-) (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFN?ß?R(-/-) mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1(-/-) and IFN?ß?R(-/-) mice, we infected an additional Stat1(-/-) strain deleted in the DNA-binding domain (129Stat1(-/-) (DBD)). These 129Stat1(-/-) (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFN?ß?R(-/-) mice. This lethal pattern was also observed when 129Stat1(-/-) (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1(-/-) (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1(-/-) mouse strains. The data are consistent with the hypothesis that Stat1(-/-) (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection. PMID:21915277

Pasieka, Tracy Jo; Collins, Lynne; O'Connor, Megan A; Chen, Yufei; Parker, Zachary M; Berwin, Brent L; Piwnica-Worms, David R; Leib, David A

2011-09-07

135

Bioluminescent imaging reveals divergent viral pathogenesis in two strains of Stat1-deficient mice, and in ?ß? interferon receptor-deficient mice.  

UK PubMed Central (United Kingdom)

Pivotal components of the IFN response to virus infection include the IFN receptors (IFNR), and the downstream factor signal transducer and activator of transcription 1 (Stat1). Mice deficient for Stat1 and IFNR (Stat1(-/-) and IFN?ß?R(-/-) mice) lack responsiveness to IFN and exhibit high sensitivity to various pathogens. Here we examined herpes simplex virus type 1 (HSV-1) pathogenesis in Stat1(-/-) mice and in IFN?ß?R(-/-) mice following corneal infection and bioluminescent imaging. Two divergent and paradoxical patterns of infection were observed. Mice with an N-terminal deletion in Stat1 (129Stat1(-/-) (N-term)) had transient infection of the liver and spleen, but succumbed to encephalitis by day 10 post-infection. In stark contrast, infection of IFN?ß?R(-/-) mice was rapidly fatal, with associated viremia and fulminant infection of the liver and spleen, with infected infiltrating cells being primarily of the monocyte/macrophage lineage. To resolve the surprising difference between Stat1(-/-) and IFN?ß?R(-/-) mice, we infected an additional Stat1(-/-) strain deleted in the DNA-binding domain (129Stat1(-/-) (DBD)). These 129Stat1(-/-) (DBD) mice recapitulated the lethal pattern of liver and spleen infection seen following infection of IFN?ß?R(-/-) mice. This lethal pattern was also observed when 129Stat1(-/-) (N-term) mice were infected and treated with a Type I IFN-blocking antibody, and immune cells derived from 129Stat1(-/-) (N-term) mice were shown to be responsive to Type I IFN. These data therefore show significant differences in viral pathogenesis between two commonly-used Stat1(-/-) mouse strains. The data are consistent with the hypothesis that Stat1(-/-) (N-term) mice have residual Type I IFN receptor-dependent IFN responses. Complete loss of IFN signaling pathways allows viremia and rapid viral spread with a fatal infection of the liver. This study underscores the importance of careful comparisons between knockout mouse strains in viral pathogenesis, and may also be relevant to the causation of HSV hepatitis in humans, a rare but frequently fatal infection.

Pasieka TJ; Collins L; O'Connor MA; Chen Y; Parker ZM; Berwin BL; Piwnica-Worms DR; Leib DA

2011-01-01

136

Colors of firefly bioluminescence. Part II. Experimental evidence for the optimization model  

Energy Technology Data Exchange (ETDEWEB)

The shapes, the peak wavelengths and the close matching of bioluminescence colors to visual spectral sensitivities in North American firefly species are consistent with the predictions of a spectral optimization model for selection in evolution. A screening pigment found by microspectrophotometry in the rhabomeres of Photinum pyralis has the absorbance characteristics predicted by the model. The biologically effective adaptation, a dimensionless ratio proportional to the relative advantage of a species to detect bioluminescence during twilight, has been calculated from experimentally determined distributions of ambient spectral radiances, visual spectral sensitivities and bioluminescence emissions and is shown to correlate both with color of bioluminescence and with the timing of initiation of flashing activity. The colors of firefly bioluminescence are therefore species-specific adaptations to optimize the detection of bioluminescence in the different photic environments in which the species have evolved.

Seliger, H.H.; Lall, A.B.; Lloyd, J.E.; Biggley, W.H.

1982-01-01

137

Bathyphotometer bioluminescence potential measurements: A framework for characterizing flow agitators and predicting flow-stimulated bioluminescence intensity  

Science.gov (United States)

Bathyphotometer measurements of bioluminescence are used as a proxy for the abundance of luminescent organisms for studying population dynamics; the interaction of luminescent organisms with physical, chemical, and biological oceanographic processes; and spatial complexity especially in coastal areas. However, the usefulness of bioluminescence measurements has been limited by the inability to compare results from different bathyphotometer designs, or even the same bathyphotometer operating at different volume flow rates. The primary objective of this study was to compare measurements of stimulated bioluminescence of four species of cultured dinoflagellates, the most common source of bioluminescence in coastal waters, using two different bathyphotometer flow agitators as a function of bathyphotometer volume flow rate and dinoflagellate concentration. For both the NOSC and BIOLITE flow agitators and each species of dinoflagellate tested, there was a critical volume flow rate, above which average bioluminescence intensity, designated as bathyphotometer bioluminescence potential (BBP), remained relatively constant and scaled directly with dinoflagellate cell concentration. At supra-critical volume flow rates, the ratio of BIOLITE to NOSC BBP was nearly constant for the same species studied, but varied between species. The spatial pattern and residence time of flash trajectories within the NOSC flow agitator indicated the presence of dominant secondary recirculating flows, where most of the bioluminescence was detected. A secondary objective (appearing in the Appendix) was to study the feasibility of using NOSC BBP to scale flow-stimulated bioluminescence intensity across similar flow fields, where the contributing composition of luminescent species remained the same. Fully developed turbulent pipe flow was chosen because it is hydrodynamically well characterized. Average bioluminescence intensity in a 2.54-cm i.d. pipe was highly correlated with wall shear stress and BBP. This correlation, when further scaled by pipe diameter, effectively predicted bioluminescence intensity in fully developed turbulent flow in a 0.83-cm i.d. pipe. Determining similar correlations between other bathyphotometer flow agitators and flow fields will allow bioluminescence potential measurements to become a more powerful tool for the oceanographic community.

Latz, Michael I.; Rohr, Jim

2013-07-01

138

Induction of luciferase activity under the control of an hsp70 promoter using high-intensity focused ultrasound: combination of bioluminescence and MRI imaging in three different tumour models.  

Science.gov (United States)

The in vivo temporal changes of luciferase activity were investigated under the control of an hsp70 promoter in three tumour models after the application of different intensities of high-intensity focused ultrasound (HIFU). Three cell lines, SCCVII, NIH3T3 and M21 were stably transfected with a plasmid containing the hsp70 promoter and luciferase reporter gene, and tumours were subcutaneously initiated into mice. At a size of 1300 ± 234 mm(3), the tumours were exposed to five intensities of continuous HIFU (802-1401-2157-3067-4133 W/cm(2)) for 20 sec. Bioluminescence and MR imaging were performed to assess luciferase activity and signal intensity changes in the tissue. The MRI scan protocol was pre- and post-contrast T1-wt-SE, T2-wt-FSE, DCE-MRI, diffusion-wt STEAM sequence, T2 relaxation time determination obtained on a 1.5-T GE MRI scanner. The NIH3T3 tumours showed the highest luciferase activity of 328.1 ± 7.1 fold at 24 h at a HIFU intensity of 3067 W/cm(2), the M21 tumours of 3.2 ± 0.6 fold 8 hours and the SCCVII tumours 2.9 ± 0.9 fold 4 hours post-HIFU at 2157 W/cm(2). The greatest increase in T2 signal intensity and T2 relaxation time of 20.7 ± 3.4% was seen in the SCCVII tumours. The highest contrast medium uptake of 10.1 ± 1.1% was noted in the M21 tumours, and 14.8 ± 1.9% in the SCCVII tumours. In all tumours, a significant increase in the diffusion coefficient was seen with increased HIFU intensity, the highest of which was 40.3 ± 4.1% in the SCCVII tumours. The three tumour cell lines stably transfected with the hsp70/luciferase gene showed differential luciferase activity, which peaked at different times after the application of HIFU and was dependant on tumour type and HIFU energy deposition. PMID:21381798

Hundt, W; Steinbach, S; Burbelko, M; Kiessling, A; Rominger, M; O'Connell-Rodwell, C E; Mayer, D; Bednarski, M D; Guccione, S

2011-04-01

139

Induction of luciferase activity under the control of an hsp70 promoter using high-intensity focused ultrasound: combination of bioluminescence and MRI imaging in three different tumour models.  

UK PubMed Central (United Kingdom)

The in vivo temporal changes of luciferase activity were investigated under the control of an hsp70 promoter in three tumour models after the application of different intensities of high-intensity focused ultrasound (HIFU). Three cell lines, SCCVII, NIH3T3 and M21 were stably transfected with a plasmid containing the hsp70 promoter and luciferase reporter gene, and tumours were subcutaneously initiated into mice. At a size of 1300 ± 234 mm(3), the tumours were exposed to five intensities of continuous HIFU (802-1401-2157-3067-4133 W/cm(2)) for 20 sec. Bioluminescence and MR imaging were performed to assess luciferase activity and signal intensity changes in the tissue. The MRI scan protocol was pre- and post-contrast T1-wt-SE, T2-wt-FSE, DCE-MRI, diffusion-wt STEAM sequence, T2 relaxation time determination obtained on a 1.5-T GE MRI scanner. The NIH3T3 tumours showed the highest luciferase activity of 328.1 ± 7.1 fold at 24 h at a HIFU intensity of 3067 W/cm(2), the M21 tumours of 3.2 ± 0.6 fold 8 hours and the SCCVII tumours 2.9 ± 0.9 fold 4 hours post-HIFU at 2157 W/cm(2). The greatest increase in T2 signal intensity and T2 relaxation time of 20.7 ± 3.4% was seen in the SCCVII tumours. The highest contrast medium uptake of 10.1 ± 1.1% was noted in the M21 tumours, and 14.8 ± 1.9% in the SCCVII tumours. In all tumours, a significant increase in the diffusion coefficient was seen with increased HIFU intensity, the highest of which was 40.3 ± 4.1% in the SCCVII tumours. The three tumour cell lines stably transfected with the hsp70/luciferase gene showed differential luciferase activity, which peaked at different times after the application of HIFU and was dependant on tumour type and HIFU energy deposition.

Hundt W; Steinbach S; Burbelko M; Kiessling A; Rominger M; O'Connell-Rodwell CE; Mayer D; Bednarski MD; Guccione S

2011-04-01

140

Real time cardiac radionuclide imaging  

International Nuclear Information System (INIS)

[en] A data acquisition system is described for use in radionuclide cardiac imaging of a patient having been administered a myocardium specific radionuclide, comprising: (a) means for monitoring the electrical activity of the heart; (b) first temporary storage means for accumulating respective pages of data corresponding to nuclear events during each cardiac cycle; (c) means, responsive to the means for monitoring, for determining the time duration of each successive cardiac cycle; (d) means for comparing each determined duration of a cardiac cycle with a preselected time duration range; (e) second temporary storage means; and (f) means for conditionally transferring pages of data from the first temporary storage means to the second temporary storage means if the measured duration associated with each page has predetermined correspondence with the preselected duration range, whereby pages of data having the predetermined correspondence may be collated into a quasi-real time study, while pages of data having different correspondence with the preselected time duration range are discarded from the study

1986-01-01

 
 
 
 
141

The reaction mechanism of calcium-activated photoprotein bioluminescence.  

UK PubMed Central (United Kingdom)

Calcium-activated photoproteins are important and useful bioluminescent reagents for detecting the calcium ion (Ca2+) in biological systems. In conjunction with photon imaging technology, they can be used to observe Ca2+-related life processes in a living cell. To develop useful applications of calcium-activated photoproteins, we need to understand the molecular basis of the bioluminescence reaction. For this purpose, this review describes the oxygenation, chemiexcitation, and light emission processes of calcium-activated photoproteins in the bioluminescence reaction together with the fundamental chemistry of the luminous substrate, coelenterazine, based on recent results from mechanistic chemical studies of these primary processes. Finally, the whole reaction mechanism, including the active site structures of apoproteins, along with available information about the molecular mechanism and the crystallographic structures of calcium-activated photoproteins are summarized.

Hirano T

2012-11-01

142

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

UK PubMed Central (United Kingdom)

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.

Rogers KL; Martin JR; Renaud O; Karplus E; Nicola MA; Nguyen M; Picaud S; Shorte SL; Brûlet P

2008-05-01

143

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

144

Bioluminescent bacteria: lux genes as environmental biosensors  

Directory of Open Access Journals (Sweden)

Full Text Available 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 environmental studies, with special emphasis on the Microtox toxicity bioassay. Also, the general ecological significance of bioluminescence will be addressed.

Nunes-Halldorson Vânia da Silva; Duran Norma Letícia

2003-01-01

145

Bioluminescence tomography with Gaussian prior  

Science.gov (United States)

Parameterizing the bioluminescent source globally in Gaussians provides several advantages over voxel representation in bioluminescence tomography. It is mathematically unique to recover Gaussians [Med. Phys. 31(8), 2289 (2004)] and practically sufficient to approximate various shapes by Gaussians in diffusive medium. The computational burden is significantly reduced since much fewer unknowns are required. Besides, there are physiological evidences that the source can be modeled by Gaussians. The simulations show that the proposed model and algorithm significantly improves accuracy and stability in the presence of Gaussian or non- Gaussian sources, noisy data or the optical background mismatch. It is also validated through in vivo experimental data.

Gao, Hao; Zhao, Hongkai; Cong, Wenxiang; Wang, Ge

2010-01-01

146

A generalized hybrid algorithm for bioluminescence tomography.  

UK PubMed Central (United Kingdom)

Bioluminescence tomography (BLT) is a promising optical molecular imaging technique on the frontier of biomedical optics. In this paper, a generalized hybrid algorithm has been proposed based on the graph cuts algorithm and gradient-based algorithms. The graph cuts algorithm is adopted to estimate a reliable source support without prior knowledge, and different gradient-based algorithms are sequentially used to acquire an accurate and fine source distribution according to the reconstruction status. Furthermore, multilevel meshes for the internal sources are used to speed up the computation and improve the accuracy of reconstruction. Numerical simulations have been performed to validate this proposed algorithm and demonstrate its high performance in the multi-source situation even if the detection noises, optical property errors and phantom structure errors are involved in the forward imaging.

Shi S; Mao H

2013-05-01

147

In vivo monitoring of tumor relapse and metastasis using bioluminescent PC-3M-luc-C6 cells in murine models of human prostate cancer.  

Science.gov (United States)

We used the bioluminescent human prostate carcinoma cell line PC-3M-luc-C6 to non-invasively monitor in vivo growth and response of tumors and metastasis before, during and after treatments. Our goal was to determine the utility of a luciferase-based prostate cancer animal model to specifically assess tumor and metastatic recurrence in vivo following chemotherapy. Bioluminescent PC-3M-luc-C6 cells, constitutively expressing luciferase, were implanted into the prostate or under the skin of mice for primary tumor assessment. Cells were also injected into the left ventricle of the heart as an experimental metastasis model. Weekly serial in vivo images were taken of anesthetized mice that were untreated or treated with 5-fluorouracil or mitomycin C. Ex vivo imaging and/or histology was used to confirm and localize metastatic lesions in various tissues initially detected by images in vivo. Our in vivo data detected and quantified early inhibition of subcutaneous and orthotopic prostate tumors in mice as well as significant tumor regrowth post-treatment. Local and distal metastasis was observed within seven days following intracardiac injection of PC-3M-luc-C6 cells. Differential drug responses and metastatic tumor relapse patterns were distinguished over time by in vivo imaging depending on the metastatic site. The longitudinal evaluation of bioluminescent tumor and metastatic development within the same cohorts of animals permitted sensitive and quantitative assessment of both primary and metastatic prostate tumor response and recurrence in vivo. PMID:14713108

Jenkins, Darlene E; Yu, Shang-Fan; Hornig, Yvette S; Purchio, Tony; Contag, Pamela R

2003-01-01

148

Automatic Segmentation Framework of Building Anatomical Mouse Model for Bioluminescence Tomography  

Directory of Open Access Journals (Sweden)

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

2013-01-01

149

Real-time depth imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis depicts approaches toward real-time depth sensing. While humans are very good at estimating distances and hence are able to smoothly control vehicles and their own movements, machines often lack the ability to sense their environment in a manner comparable to humans. This discrepancy pre...

Hahne, Uwe

150

Real-time Registration for Image Mosaicing  

UK PubMed Central (United Kingdom)

This paper presents a real-time tracking technique for constructing sphericalimage mosaics from sequences of images. The main contribution is a trackingalgorithm able to estimate in real-time camera rotations during the sequence,assuming that the optical center of the camera remain fixed. This assumptionallows us to consider a sphere centered at this particular point and having itsradius equal to the focal length of the camera. The problem is to estimate foreach image of the sequence the position of the image plane relatively to thissphere and to back project the image to create the global spherical mosaicimage. The proposed algorithm allows, during a first stage, to track in realtime (less than 12ms for each image) the camera rotations around the opticalcenter. This is done by using a real-time template matching algorithm, usingthe formalism described in [2], adapted in order to estimate only 3D camerarotations. After this stage, each one of the images of the sequence are locatedrelatively to the spherical image. In a second step, the spherical image isbuild by back projecting on the sphere the images of the sequence. Thispaper is mainly devoted to the description of the first stage. Experimentalresults proving the efficiency of the proposed approach are given.

E. Noirfalise; J. T. Laprest; F. Jurie; M Dhome

151

Space-time feature-specific imaging  

Science.gov (United States)

Feature-specific imaging (FSI) or compressive imaging involves measuring relatively few linear projections of a scene compared to the dimensionality of the scene. Researchers have exploited the spatial correlation inherent in natural scenes to design compressive imaging systems using various measurement bases such as Karhunen-Lo`eve (KL) transform, random projections, Discrete Cosine transform (DCT) and Discrete Wavelet transform (DWT) to yield significant improvements in system performance and size, weight, and power (SWaP) compared to conventional non-compressive imaging systems. Here we extend the FSI approach to time-varying natural scenes by exploiting the inherent spatio-temporal correlations to make compressive measurements. The performance of space-time feature-specific/compressive imaging systems is analyzed using the KL measurement basis. We find that the addition of temporal redundancy in natural time-varying scenes yields further compression relative to space-only feature specific imaging. For a relative noise strength of 10% and reconstruction error of 10% using 8×8×16 spatio-temporal blocks we find about a 114x compression compared to a conventional imager while space-only FSI realizes about a 32x compression. We also describe a candidate space-time compressive optical imaging system architecture.

Treeaporn, Vicha; Ashok, Amit; Neifeld, Mark A.

2011-05-01

152

Microbiological assay using bioluminescent organism  

UK PubMed Central (United Kingdom)

A microbiological assay based on bioluminesce employing the bioluminescent dinoflagellate Pyrocystis lunula. An oil well drilling fluid sample is prepared according to E. P. A. procedures to obtain a suspended particulate phase sample. An aliquot of the sample is added to a growth medium containing Pyrocystis lunula in suspension. The mixture is agitated to subject the Pyrocystis lunula to a shear stress. Light emitted as a result of the shear stress on the Pyrocystis lunula is measure and compared with a control to determine if there is diminution of light produced by the Pyrocystis lunula in the mixture. Diminution of light production is an indication of the presence of a toxic substance in the sample.

STIFFEY ARTHUR V

153

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

154

Colonization of tomato seedlings by bioluminescent Clavibacter michiganensis subsp. michiganensis under different humidity regimes.  

UK PubMed Central (United Kingdom)

Tomato bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis, is transmitted by infected or infested seed and mechanically from plant to plant. Wounds occurring during seedling production and crop maintenance facilitate the dissemination of the pathogen. However, the effects of environmental factors on C. michiganensis subsp. michiganensis translocation and growth as an endophyte have not been fully elucidated. A virulent, stable, constitutively bioluminescent C. michiganensis subsp. michiganensis strain BL-Cmm 17 coupled with an in vivo imaging system allowed visualization of the C. michiganensis subsp. michiganensis colonization process in tomato seedlings in real time. The dynamics of bacterial infection in seedlings through wounds were compared under low (45%) and high (83%) relative humidity. Bacteria multiplied rapidly in cotyledon petioles remaining after clip inoculation and moved in the stem toward both root and shoot. Luminescent signals were also observed in tomato seedling roots over time, and root development was reduced in inoculated plants maintained under both humidity regimes. Wilting was more severe in seedlings under high-humidity regimes. A strong positive correlation between light intensity and bacterial population in planta suggests that bioluminescent C. michiganensis subsp. michiganensis strains will be useful in evaluating the efficacy of bactericides and host resistance.

Xu X; Rajashekara G; Paul PA; Miller SA

2012-02-01

155

Real-Time In Vivo Bioluminescent Imaging for Evaluating the Efficacy of Antibiotics in a Rat Staphylococcus aureus Endocarditis Model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Therapeutic options for invasive Staphylococcus aureus infections have become limited due to rising antimicrobial resistance, making relevant animal model testing of new candidate agents more crucial than ever. In the present studies, a rat model of aortic infective endocarditis (IE) caused by a bio...

Xiong, Yan Q.; Willard, Julie; Kadurugamuwa, Jagath L.; Yu, Jun; Francis, Kevin P.; Bayer, Arnold S.

156

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.

Brian Cusack; Jon Pearse

2011-01-01

157

A multilevel adaptive finite element algorithm for bioluminescence tomography  

Science.gov (United States)

As a new mode of molecular imaging, bioluminescence tomography (BLT) has become a hot topic over the past two years. In this paper, a multilevel adaptive finite element algorithm is developed for BLT reconstruction. In this algorithm, the mesh is adaptively refined according to a posteriori error estimation, which helps not only to improve localization and quantification of sources but also to enhance the robustness and efficiency of reconstruction. In the numerical simulation, bioluminescent signals on the body surface of a heterogeneous phantom are synthesized in a molecular optical simulation environment (MOSE) that we developed to model the photon transportation via Monte Carlo simulation. The performance of the algorithm is evaluated in numerical tests involving single and multiple sources in various arrangements. The results demonstrate the merits and potential of the multilevel adaptive approach for BLT.

Lv, Yujie; Tian, Jie; Cong, Wenxiang; Wang, Ge; Luo, Jie; Yang, Wei; Li, Hui

2006-09-01

158

Monsters of the Deep: Deep Sea Bioluminescence  

Science.gov (United States)

This award-winning Sea and Sky website uses creative graphics to explore deep sea bioluminescence. It defines the phenomenon of bioluminescence, explains the chemical reactions involved, describes organisms with this adaptation, and investigates possible reasons for this dazzling light show. Links direct users to similar pages about hydrothermal vents, ocean layers, and more.

Knight, J. D.; Sky, Sea A.

159

Stimulable and spontaneous bioluminescence in the marine dinoflagellates, Pyrodinium bahamense, Gonyaulax polyedra, and Pyrocystis lunula.  

Science.gov (United States)

P. bahamense, G. polyedra, and P. lunula exhibit interspecies differences in stimulable and spontaneous bioluminescence. For each species the total number of photons that can be emitted upon mechanical stimulation is a constant, regardless of the time during scotophase at which stimulation occurs. Ratios of stimulable bioluminescence per organism during scotophase and photophase are as high as 950:1 for laboratory cultures and have been observed as high as 4000: 1 for natural populations of P. bahamense. Spontaneous emission in darkness shows flashing as well as low-level continuous emission. Natural populations of P. bahamense, placed in darkness during natural photophase, exhibit a dual character to their stimulable bioluminescence. Mechanical stimulation techniques are described for rapid and reproducible stimulation of bioluminescence. PMID:5792367

Biggley, W H; Swift, E; Buchanan, R J; Seliger, H H

1969-07-01

160

Stimulable and spontaneous bioluminescence in the marine dinoflagellates, Pyrodinium bahamense, Gonyaulax polyedra, and Pyrocystis lunula.  

UK PubMed Central (United Kingdom)

P. bahamense, G. polyedra, and P. lunula exhibit interspecies differences in stimulable and spontaneous bioluminescence. For each species the total number of photons that can be emitted upon mechanical stimulation is a constant, regardless of the time during scotophase at which stimulation occurs. Ratios of stimulable bioluminescence per organism during scotophase and photophase are as high as 950:1 for laboratory cultures and have been observed as high as 4000: 1 for natural populations of P. bahamense. Spontaneous emission in darkness shows flashing as well as low-level continuous emission. Natural populations of P. bahamense, placed in darkness during natural photophase, exhibit a dual character to their stimulable bioluminescence. Mechanical stimulation techniques are described for rapid and reproducible stimulation of bioluminescence.

Biggley WH; Swift E; Buchanan RJ; Seliger HH

1969-07-01

 
 
 
 
161

Time-resolved fluorescence anisotropy imaging.  

UK PubMed Central (United Kingdom)

Fluorescence can be characterized by its intensity, position, wavelength, lifetime, and polarization. The more of these features are acquired in a single measurement, the more can be learned about the sample, i.e., the microenvironment of the fluorescence probe. Polarization-resolved fluorescence lifetime imaging-time-resolved fluorescence anisotropy imaging, TR-FAIM-allows mapping of viscosity or binding or of homo-FRET which can indicate dimerization or generally oligomerization.

Suhling K; Levitt J; Chung PH

2014-01-01

162

Thermal imaging with real time picture presentation.  

UK PubMed Central (United Kingdom)

The accomplishment of thermal imaging with real-time picture presentation represents a significant advance in nondestructive testing. Described here is the AGA Thermovision, capable of producing such imaging. Operating principles, basic features, and recording techniques are reviewed, and a survey is made of the range of applications. Examples include electrical power distribution elements, a turbine blade, and a missile model in a wind tunnel.

Borg SB

1968-09-01

163

Thermal imaging with real time picture presentation.  

Science.gov (United States)

The accomplishment of thermal imaging with real-time picture presentation represents a significant advance in nondestructive testing. Described here is the AGA Thermovision, capable of producing such imaging. Operating principles, basic features, and recording techniques are reviewed, and a survey is made of the range of applications. Examples include electrical power distribution elements, a turbine blade, and a missile model in a wind tunnel. PMID:20068870

Borg, S B

1968-09-01

164

Synthesized images with intensified relaxation time effect  

International Nuclear Information System (INIS)

Saturation recovery sequence with the spin echo signals for imaging is the most basic method for MRI. Many investigations on the T1 and T2 values in lesions show that the strong correlations can be stated between T1 and T2 value prolongations. However, the prolongation in T1 and T2 give a reversed effect on the pixel intensity change in MRI. Therefore, in the conventional MRI, the pixel intensities show the inconveniently suppressed relaxation time prolongation effect. A new functional imaging method, which can show a monotonic image intensity change in accordance with the T1 and T2 prolongations in the brain tumors, is presented. This synthesized imaging is obtained by calculating images with pixel intensities in accordance with the following formula: I ? [1 - exp (-TR/T1)] exp (qTE/T2) where q is a constant with positive value. Our images are calculated without using such unstable calculations as exponentially decaying curve analysis. These images were useful to distinguish brain tumor from surrounding edema. This new imaging method will be applied routinely to clinical cases in future. (author).

1988-01-01

165

A novel bioluminescence mouse model for monitoring oropharyngeal candidiasis in mice.  

Science.gov (United States)

Oropharyngeal Candida albicans (C. albicans) infection usually occurs in patients with altered cell-mediated immune response. Many animal models have been developed for studying the pathogenesis of disease. Here we describe a new model for real-time monitoring of oral candidiasis. Mice were rendered susceptible to oral candidiasis by injection with cortisone acetate. Oral infection was performed by placing a swab saturated with genetically engineered bioluminescent strain of C. albicans sublingually. An in vivo imaging technique, exploiting stably trasformed C. albicans that costitutively express luciferase, was adopted. This novel longitudinal study represents a powerful tool to: (1) test real-time progression of infection, (2) identify the target site of C. albicans in specific organs, (3) evaluate the efficacy of antifungal therapies and (4) explore the spread of C. albicans from the local to systemic compartment in a new way. PMID:23334179

Mosci, Paolo; Pericolini, Eva; Gabrielli, Elena; Kenno, Samyr; Perito, Stefano; Bistoni, Francesco; d'Enfert, Christophe; Vecchiarelli, Anna

2013-01-18

166

A novel bioluminescence mouse model for monitoring oropharyngeal candidiasis in mice.  

UK PubMed Central (United Kingdom)

Oropharyngeal Candida albicans (C. albicans) infection usually occurs in patients with altered cell-mediated immune response. Many animal models have been developed for studying the pathogenesis of disease. Here we describe a new model for real-time monitoring of oral candidiasis. Mice were rendered susceptible to oral candidiasis by injection with cortisone acetate. Oral infection was performed by placing a swab saturated with genetically engineered bioluminescent strain of C. albicans sublingually. An in vivo imaging technique, exploiting stably trasformed C. albicans that costitutively express luciferase, was adopted. This novel longitudinal study represents a powerful tool to: (1) test real-time progression of infection, (2) identify the target site of C. albicans in specific organs, (3) evaluate the efficacy of antifungal therapies and (4) explore the spread of C. albicans from the local to systemic compartment in a new way.

Mosci P; Pericolini E; Gabrielli E; Kenno S; Perito S; Bistoni F; d'Enfert C; Vecchiarelli A

2013-04-01

167

Multiplexing bioluminescent and fluorescent reporters to monitor live cells.  

UK PubMed Central (United Kingdom)

Reporter proteins are valuable tools to monitor promoter activities and characterize signal transduction pathways. Many of the currently available promoter reporters have drawbacks that compromise their performance. Enzyme-based reporter systems using cytosolic luciferases are highly sensitive, but require a cell lysis step that prevents their use in long-term monitoring. By contrast, secreted bioluminescent reporters like Metridia luciferase and Secreted Alkaline Phosphatase can be assayed repeatedly, using supernatant from the same live cell population to produce many sets of data over time. This is crucial for studies with limited amounts of cells, as in the case of stem cells. The use of secreted bioluminescent reporters also enables broader applications to provide more detailed information using live cells; for example, multiplexing with fluorescent proteins. Here, data is presented describing the characteristics of secreted Metridia luciferase and its use in multiplexing applications with either Secreted Alkaline Phosphatase or a fluorescent protein.

Haugwitz M; Nourzaie O; Garachtchenko T; Hu L; Gandlur S; Olsen C; Farmer A; Chaga G; Sagawa H

2008-01-01

168

Multiplexing bioluminescent and fluorescent reporters to monitor live cells.  

Science.gov (United States)

Reporter proteins are valuable tools to monitor promoter activities and characterize signal transduction pathways. Many of the currently available promoter reporters have drawbacks that compromise their performance. Enzyme-based reporter systems using cytosolic luciferases are highly sensitive, but require a cell lysis step that prevents their use in long-term monitoring. By contrast, secreted bioluminescent reporters like Metridia luciferase and Secreted Alkaline Phosphatase can be assayed repeatedly, using supernatant from the same live cell population to produce many sets of data over time. This is crucial for studies with limited amounts of cells, as in the case of stem cells. The use of secreted bioluminescent reporters also enables broader applications to provide more detailed information using live cells; for example, multiplexing with fluorescent proteins. Here, data is presented describing the characteristics of secreted Metridia luciferase and its use in multiplexing applications with either Secreted Alkaline Phosphatase or a fluorescent protein. PMID:20161823

Haugwitz, Michael; Nourzaie, Omar; Garachtchenko, Tatiana; Hu, Lanrong; Gandlur, Suvarna; Olsen, Cathy; Farmer, Andrew; Chaga, Grigoriy; Sagawa, Hiroaki

2008-02-25

169

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

170

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

UK PubMed Central (United Kingdom)

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).

Chen SF; Ferré N; Liu YJ

2013-06-01

171

Bioluminescence-based monitoring of virus vector-mediated gene transfer in mice.  

UK PubMed Central (United Kingdom)

In vivo bioluminescence imaging (BLI) is a powerful technology that gives information on biological processes in living animals over multiple time points. Importantly BLI can also yield anatomical localization of signal which can provide important information when performing biodistribution studies of different macromolecules. This is of particular interest for gene therapy vectors such as adeno-associated virus (AAV) vectors in which knowledge of in vivo gene expression profiles help characterize what target tissues or organs the vector may be useful for. It can also be utilized to assess novel vector systems for their ability to overcome specific in vivo barriers of effective gene therapy. Here we describe BLI of AAV-encoded firefly luciferase (Fluc) expression in mice after intravascular delivery. This protocol can be amended for use with different virus vectors (e.g., lentivirus, adenovirus) as well as nonviral gene delivery (e.g., plasmid DNA, liposomes).

Maguire CA

2014-01-01

172

Polynomial-time solutions to image segmentation  

Energy Technology Data Exchange (ETDEWEB)

Separating an object in an image from its background is a central problem (called segmentation) in pattern recognition and computer vision. In this paper, we study the complexity of the segmentation problem, assuming that the object forms a connected region in an intensity image. We show that the optimization problem of separating a connected region in an n-pixel grid is NP-hard under the interclass variance, a criterion that is used in discriminant analysis. More importantly, we consider the basic case in which the object is separated by two x-monotone curves (i.e., the object itself is x-monotone), and present polynomial-time algorithms for computing exact and approximate optimal segmentation. Our main algorithm for exact optimal segmentation by two x-monotone curves runs in O(n{sup 2}) time; this algorithm is based on several techniques such as a parametric optimization formulation, a hand-probing algorithm for the convex hull of an unknown point set, and dynamic programming using fast matrix searching. Our efficient approximation scheme obtains an {epsilon}-approximate solution in O({epsilon}{sup -1} n log L) time, where {epsilon} is any fixed constant with 1 > {epsilon} > 0, and L is the total sum of the absolute values of brightness levels of the image.

Asano, Tetsuo [Osaka Electro-Communication Univ., Neyagawa (Japan); Chen, D.Z. [Notre Dame, South Bend, IN (United States); Katoh, Naoki [Kobe Univ. of Commerce (Japan)

1996-12-31

173

Coupled bioluminescent assays methods, evaluations, and applications  

CERN Document Server

This book highlights the applications of coupled bioluminescence assay techniques to real-world problems in drug discovery, environmental and chemical analysis, and biodefense. It separates theoretical aspects from the applied sections in a clear and readable way. Coupled Bioluminescent Assays, explains the uses of CB technologies across drug discovery to analyze toxicity, drug receptors, and enzymes. It covers applications in environmental analysis and biodefense, including cytotoxicity, fertilizer and explosives analysis, and nerve agent and pesticide detection. This is the premier reference

Corey, Michael J

2008-01-01

174

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 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.

2011-01-01

175

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 (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

176

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; Sanjay Kumar Dubey

2013-01-01

177

Metabolic Imaging in Multiple Time Scales.  

UK PubMed Central (United Kingdom)

We report here a novel combination of time-resolved imaging methods for probing mitochondrial metabolism multiple time scales at the level of single cells. By exploiting a mitochondrial membrane potential reporter fluorescence we demonstrate the single cell metabolic dynamics in time scales ranging from milliseconds to seconds to minutes in response to glucose metabolism and mitochondrial perturbations in real time. Our results show that in comparison with normal human mammary epithelial cells, the breast cancer cells display significant alterations in metabolic responses at all measured time scales by single cell kinetics, fluorescence recovery after photobleaching and by scaling analysis of time-series data obtained from mitochondrial fluorescence fluctuations. Furthermore scaling analysis of time-series data in living cells with distinct mitochondrial dysfunction also revealed significant metabolic differences thereby suggesting the broader applicability (e.g. in mitochondrial myopathies and other metabolic disorders) of the proposed strategies beyond the scope of cancer metabolism. We discuss the scope of these findings in the context of developing portable, real-time metabolic measurement systems that can find applications in preclinical and clinical diagnostics.

Krishnan Ramanujan V

2013-08-01

178

Bioluminescence enhancement through an added washing protocol enabling a greater sensitivity to carbofuran toxicity.  

UK PubMed Central (United Kingdom)

The effects of carbofuran toxicity on a genetically modified bacterial strain E. coli DPD2794 were enhanced using a new bioluminescent protocol which consisted of three consecutive steps: incubation, washing and luminescence reading. Specifically, in the first step, several concentrations of carbofuran aqueous solutions were incubated with different bacterial suspensions at recorded optical densities for different lengths of time. Thereafter, the resulting bacterial/toxicant mixtures were centrifuged and the aged cellular supernatant replaced with fresh medium. In the final step, the carbofuran- induced bioluminescence to the exposed E. coli DPD2794 bacteria was shown to provide a faster and higher intensity when recorded at a higher temperature at30°C which is not usually used in the literature. It was found that the incubation time and the replacement of aged cellular medium were essential factors to distinguish different concentrations of carbofuran in the bioluminescent assays. From our results, the optimum incubation time for a "light ON" bioluminescence detection of the effect of carbofuran was 6h. Thanks to the replacement of the aged cellular medium, a group of additional peaks starting around 30min were observed and we used the corresponding areas under the curve (AUC) at different contents of carbofuran to produce the calibration curve. Based on the new protocol, a carbofuran concentration of 0.5pg/mL can be easily determined in a microtiter plate bioluminescent assay, while a non-wash protocol provides an unexplainable order of curve evolutionswhich does not allow the user to determine the concentration.

Jia K; Eltzov E; Marks RS; Ionescu RE

2013-10-01

179

A Monte-Carlo-Based Network Method for Source Positioning in Bioluminescence Tomography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present an approach based on the improved Levenberg Marquardt (LM) algorithm of backpropagation (BP) neural network to estimate the light source position in bioluminescent imaging. For solving the forward problem, the table-based random sampling algorithm (TBRS), a fast Monte Carlo simulation me...

Xu, Zhun; Song, Xiaolei; Zhang, Xiaomeng; Bai, Jing

180

Bacteria bioluminescent activity as an indicator of geomagnetic disturbances  

International Nuclear Information System (INIS)

[en] 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

1995-01-01

 
 
 
 
181

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

182

4D Multimodality Imaging of Citrobacter rodentium Infections in Mice.  

UK PubMed Central (United Kingdom)

This protocol outlines the steps required to longitudinally monitor a bioluminescent bacterial infection using composite 3D diffuse light imaging tomography with integrated ?CT (DLIT-?CT) and the subsequent use of this data to generate a four dimensional (4D) movie of the infection cycle. To develop the 4D infection movies and to validate the DLIT-?CT imaging for bacterial infection studies using an IVIS Spectrum CT, we used infection with bioluminescent C. rodentium, which causes self-limiting colitis in mice. In this protocol, we outline the infection of mice with bioluminescent C. rodentium and non-invasive monitoring of colonization by daily DLIT-?CT imaging and bacterial enumeration from feces for 8 days. The use of the IVIS Spectrum CT facilitates seamless co-registration of optical and ?CT scans using a single imaging platform. The low dose ?CT modality enables the imaging of mice at multiple time points during infection, providing detailed anatomical localization of bioluminescent bacterial foci in 3D without causing artifacts from the cumulative radiation. Importantly, the 4D movies of infected mice provide a powerful analytical tool to monitor bacterial colonization dynamics in vivo.

Collins JW; Meganck JA; Kuo C; Francis KP; Frankel G

2013-01-01

183

The First Bioluminescence Tomography System for Simultaneous Acquisition of Multiview and Multispectral Data  

Directory of Open Access Journals (Sweden)

Full Text Available We describe the system design of the first bioluminescence tomography (BLT) system for parallel acquisition of multiple bioluminescent views around a mouse in a number of spectral channels simultaneously. The primary component of this BLT system is a novel mirror module and a unique mouse holder. The mirror module consists of a mounting plate and four mirrors with stages. These mirror stages are right triangular blocks symmetrically arranged and attached to the mounting plate such that the hypotenuse surfaces of the triangular blocks all make 45∘ to the plate surface. The cylindrical/polygonal mouse holder has semitransparent rainbow bands on its side surface for the acquisition of spectrally resolved data. Numerical studies and experiments are performed to demonstrate the feasibility of this system. It is shown that bioluminescent signals collected using our system can produce a similar BLT reconstruction quality while reducing the data acquisition time, as compared to the sequential data acquisition mode.

Ge Wang; Haiou Shen; Kumar Durairaj; Xin Qian; Wenxiang Cong

2006-01-01

184

Modeling bioluminescent photon transport in tissue based on Radiosity-diffusion model  

Science.gov (United States)

Bioluminescence tomography (BLT) is one of the most important non-invasive optical molecular imaging modalities. The model for the bioluminescent photon propagation plays a significant role in the bioluminescence tomography study. Due to the high computational efficiency, diffusion approximation (DA) is generally applied in the bioluminescence tomography. But the diffusion equation is valid only in highly scattering and weakly absorbing regions and fails in non-scattering or low-scattering tissues, such as a cyst in the breast, the cerebrospinal fluid (CSF) layer of the brain and synovial fluid layer in the joints. A hybrid Radiosity-diffusion model is proposed for dealing with the non-scattering regions within diffusing domains in this paper. This hybrid method incorporates a priori information of the geometry of non-scattering regions, which can be acquired by magnetic resonance imaging (MRI) or x-ray computed tomography (CT). Then the model is implemented using a finite element method (FEM) to ensure the high computational efficiency. Finally, we demonstrate that the method is comparable with Mont Carlo (MC) method which is regarded as a 'gold standard' for photon transportation simulation.

Sun, Li; Wang, Pu; Tian, Jie; Zhang, Bo; Han, Dong; Yang, Xin

2010-03-01

185

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.

Matthew A. Lewis; Edmond Richer; Nikolai V. Slavine; Vikram D. Kodibagkar; Todd C. Soesbe; Peter P. Antich; Ralph P. Mason

2013-01-01

186

Optical biosensor for environmental on-line monitoring of naphthalene and salicylate bioavailability with an immobilized bioluminescent catabolic reporter bacterium  

Energy Technology Data Exchange (ETDEWEB)

An optical whole-cell biosensor based on a genetically engineered bioluminescent catabolic reporter bacterium was developed for continuous on-line monitoring of naphthalene and salicylate bioavailability and microbial catabolic activity potential in waste streams. The bioluminescent reporter bacterium, Pseudomonas fluorescens HK44, carries a transcriptional nahG-luxCDABE fusion for naphthalene and salicylate catabolism. Exposure to either compound resulted in inducible bioluminescence. The reporter culture was immobilized onto the surface of an optical guide by using strontium alginate. The biosensor probe was then inserted into a measurement cell which simultaneously received the waste stream solution and a maintenance medium. Exposure under defined conditions to both naphthalene and salicylate resulted in a rapid increase in bioluminescence. The magnitude of the response and the response time were concentration dependent. Good reproducibility of the response was observed during repetitive perturbations with either napthalene or salicylate. Exposure to other compounds, such as glucose and complex nutrient medium or toluene, resulted in either minor bioluminescence increases after significantly longer response times compared with naphthalene or no response, respectively. The environmental utility of the biosensor was tested by using real pollutant mixtures. A specific bioluminescence response was obtained after exposure to either an aqueous solution saturated with JP-4 fuel or an aqueous leachate from a manufactured-gas plant soil, since napthalene was present in both pollutant mixtures. 43 refs., 4 figs., 1 tab.

Heitzer, A.; Malachowsky, K.; Thonnard, J.E. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

1994-05-01

187

Adaptive row-action inverse solver for fast noise-robust three-dimensional reconstructions in bioluminescence tomography: theory and dual-modality optical/computed tomography in vivo studies.  

UK PubMed Central (United Kingdom)

A novel approach is presented for obtaining fast robust three-dimensional (3-D) reconstructions of bioluminescent reporters buried deep inside animal subjects from multispectral images of surface bioluminescent photon densities. The proposed method iteratively acts upon the equations relating the multispectral data to the luminescent distribution with high computational efficiency to provide robust 3-D reconstructions. Unlike existing algebraic reconstruction techniques, the proposed method is designed to use adaptive projections that iteratively guide the updates to the solution with improved speed and robustness. Contrary to least-squares reconstruction methods, the proposed technique does not require parameter selection or optimization for optimal performance. Additionally, optimized schemes for thresholding, sampling, and ordering of the bioluminescence tomographic data used by the proposed method are presented. The performance of the proposed approach in reconstructing the shape, volume, flux, and depth of luminescent inclusions is evaluated in a multitude of phantom-based and dual-modality in vivo studies in which calibrated sources are implanted in animal subjects and imaged in a dual-modality optical/computed tomography platform. Statistical analysis of the errors in the depth and flux of the reconstructed inclusions and the convergence time of the proposed method is used to demonstrate its unbiased performance, low error variance, and computational efficiency.

Behrooz A; Kuo C; Xu H; Rice B

2013-07-01

188

Chemistry and biology of insect bioluminescence  

Energy Technology Data Exchange (ETDEWEB)

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.

Colepicolo Neto, P.; Bechara, E.J.H. (Sao Paulo Univ. (Brazil). Inst. de Quimica)

1984-12-01

189

Bacterial bioluminescence as a bioassay for mycotoxins.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Yates, I E; Porter, J K

190

Bioluminescence as a light source for photosynthesis.  

Science.gov (United States)

The luminol bioluminescence system containing luminol, hydrogen peroxide and HRP was used as a potential substitute light source of sunlight for the photosynthesis of plants, in which the electron flow of the photosynthesis process was proven using chloroplasts isolated from spinach leaves. PMID:24108441

Yuan, Huanxiang; Liu, Libing; Lv, Fengting; Wang, Shu

2013-10-22

191

Bacterial bioluminescence: applications in food microbiology.  

UK PubMed Central (United Kingdom)

Many marine microorganisms (Vibrio, Photobacterium) are capable of emitting light, that is, they are bioluminescent. The light-yielding reaction is catalyzed by a luciferase, and it involves the oxidation of reduced riboflavin phosphate and a long-chain aldehyde in the presence of oxygen to produce a blue green light. The genes responsible for the luciferase production, (lux A and lux B), aldehyde synthesis (lux C, D, and E), and regulation of luminescence (lux I and lux R) have all been identified, and recent research has resulted in the discovery of three new genes (lux F, G, and H). The ability to genetically engineer dark microorganisms to become light emitting by introducing the lux genes into them has opened up a wide range of applications of bioluminescence. Assays using bacterial bioluminescence for the detection and enumeration of microorganisms are rapid, sensitive. accurate. and can be made specific. It is these attributes that are making in vivo bioluminescent assays so attractive to the food industry.

Baker JM; Griffiths MW; Collins-Thompson DL

1992-01-01

192

Bioluminescence as a light source for photosynthesis.  

UK PubMed Central (United Kingdom)

The luminol bioluminescence system containing luminol, hydrogen peroxide and HRP was used as a potential substitute light source of sunlight for the photosynthesis of plants, in which the electron flow of the photosynthesis process was proven using chloroplasts isolated from spinach leaves.

Yuan H; Liu L; Lv F; Wang S

2013-10-01

193

Is it time for cardiac innervation imaging?  

International Nuclear Information System (INIS)

[en] The autonomic nervous system plays an important role in the regulation of cardiac function and the regional distribution of cardiac nerve terminals can be visualized using scintigraphic techniques. The most commonly used tracer is iodine-123-metaiodobenzylguanidine (MIBG) but C-11-hydroxyephedrine has also been used with PET. When imaging with MIBG, the ratio of heart-to-mediastinal counts is used as an index of tracer uptake, and regional distribution is also assessed from tomographic images. The rate of clearance of the tracer can also be measured and indicates the function of the adrenergic system. Innervation imaging has been applied in patients with susceptibility to arrythmias, coronary artery disease, hypertrophic and dilated cardiomyopathy and anthracycline induced cardiotoxicity. Abnormal adrenergic innervation or function appear to exist in many pathophysiological conditions indicating that sympathetic neurons are very susceptible to damage. Abnormal findings in innervation imaging also appear to have significant prognostic value especially in patients with cardiomyopathy. Recently, it has also been shown that innervation imaging can monitor drug-induced changes in cardiac adrenergic activity. Although innervation imaging holds great promise for clinical use, the method has not received wider clinical acceptance. Larger randomized studies are required to confirm the value of innervation imaging in various specific indications

2005-01-01

194

Optical time-domain analog pattern correlator for high-speed real-time image recognition.  

UK PubMed Central (United Kingdom)

The speed of image processing is limited by image acquisition circuitry. While optical pattern recognition techniques can reduce the computational burden on digital image processing, their image correlation rates are typically low due to the use of spatial optical elements. Here we report a method that overcomes this limitation and enables fast real-time analog image recognition at a record correlation rate of 36.7 MHz--1000 times higher rates than conventional methods. This technique seamlessly performs image acquisition, correlation, and signal integration all optically in the time domain before analog-to-digital conversion by virtue of optical space-to-time mapping.

Kim SH; Goda K; Fard A; Jalali B

2011-01-01

195

Optical time-domain analog pattern correlator for high-speed real-time image recognition.  

Science.gov (United States)

The speed of image processing is limited by image acquisition circuitry. While optical pattern recognition techniques can reduce the computational burden on digital image processing, their image correlation rates are typically low due to the use of spatial optical elements. Here we report a method that overcomes this limitation and enables fast real-time analog image recognition at a record correlation rate of 36.7 MHz--1000 times higher rates than conventional methods. This technique seamlessly performs image acquisition, correlation, and signal integration all optically in the time domain before analog-to-digital conversion by virtue of optical space-to-time mapping. PMID:21263506

Kim, Sang Hyup; Goda, Keisuke; Fard, Ali; Jalali, Bahram

2011-01-15

196

Time Exposure Acoustics for Imaging Underground Structures.  

Science.gov (United States)

The coal mine study demonstrates that passive imaging is feasible under realistic conditions, but improvements are certainly possible. For example, some noticeable phase rotation of the seismic traces across the array is evident when the traces are plotte...

I. J. Won

2005-01-01

197

Real time neutron radiography using a Lixi neutron imaging device  

International Nuclear Information System (INIS)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Ill. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain quantitative information on the object being imaged. (orig.)

1986-01-15

198

Real time neutron radiography using a Lixi neutron imaging device  

Energy Technology Data Exchange (ETDEWEB)

A real time neutron radiography system has been developed at the University of Michigan Phoenix Memorial Laboratory (PML) and has recently been used to test the imaging capabilities of a neutron imaging device developed by Lixi, Inc. of Downers Grove, Illinois. This device uses an input phosphor that is high in gadolinium to generate a light image which is then sent through an intensifier stage to provide images that can be viewed by eye, video camera, or standard 35 mm camera. It was determined that this device provides images of much higher resolution and sensitivity than those obtained with the imaging system currently being used at PML. Using computerized image enhancement techniques, the images obtained with the Lixi neutron imaging device can then be further enhanced or processed to obtain quantitative information on the object being imaged.

Lindsay, J.T.; Jones, J.D.; Kauffman, C.W.; Van Pelt, B.

1986-01-15

199

Constant-time chemical-shift selective imaging.  

UK PubMed Central (United Kingdom)

We demonstrate that chemical-shift-selective constant-time imaging (CTI) can be performed by simply inserting selective saturation into the original imaging pulse sequence. The performance of the proposed method is illustrated by (7)Li CTI imaging in a battery model that contains both Li metal electrodes and an electrolyte containing a dissolved Li salt.

Giesecke M; Dvinskikh SV; Furó I

2013-01-01

200

Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes.  

UK PubMed Central (United Kingdom)

Bioluminescence induced by multifarious stimuli has long been observed and is remains under investigation because of its great complexity. In particular, the exact mechanism underlying bioluminescence is not yet fully understood. This work presents a new experimental method for studying Noctiluca sp. bioluminescence under temperature change stimulation. It is a study of Noctiluca sp. bioluminescence using controlled temperature changes in a tank. A characteristic of this experiment is the large volume of water used (1?m(3) in a tank of 2?×?1?×?1?m). Temperature changes were controlled by two methods. In the first, a flask filled with hot water was introduced into the tank and in the second, a water heater was used in the tank. Temperature changes were recorded using sensors. Noctiluca sp. bioluminescence was recorded using a Canon 5D Mark II and this allowed the characteristics of Noctiluca sp. bioluminescence under temperature change stimulation to be monitored. Copyright © 2012 John Wiley & Sons, Ltd.

Han J; Li G; Liu H; Hu H; Zhang X

2012-09-01

 
 
 
 
201

Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes.  

Science.gov (United States)

Bioluminescence induced by multifarious stimuli has long been observed and is remains under investigation because of its great complexity. In particular, the exact mechanism underlying bioluminescence is not yet fully understood. This work presents a new experimental method for studying Noctiluca sp. bioluminescence under temperature change stimulation. It is a study of Noctiluca sp. bioluminescence using controlled temperature changes in a tank. A characteristic of this experiment is the large volume of water used (1?m(3) in a tank of 2?×?1?×?1?m). Temperature changes were controlled by two methods. In the first, a flask filled with hot water was introduced into the tank and in the second, a water heater was used in the tank. Temperature changes were recorded using sensors. Noctiluca sp. bioluminescence was recorded using a Canon 5D Mark II and this allowed the characteristics of Noctiluca sp. bioluminescence under temperature change stimulation to be monitored. Copyright © 2012 John Wiley & Sons, Ltd. PMID:23001957

Han, Jing; Li, Guijuan; Liu, Huanying; Hu, Haohao; Zhang, Xuegang

2012-09-24

202

Time-Scale Dependencies for Image Compression  

Directory of Open Access Journals (Sweden)

Full Text Available The definition of an atomic representation of the wavelet transform of a signal allows us to write the evolution law through scales for modulus maxima of the transform. Although this result is very general and useful for various fields of image processing, we focus on its application to signal and image compression. We propose a simple trick for taking advantage from the law without directly solving its corresponding partial differential equation. Preliminary experimental results show that the proposed approach outperforms available compression techniques.

Vittoria Bruni; Benedetto Piccoli; Domenico Vitulano

2006-01-01

203

Generation and comparison of bioluminescent and fluorescent Bacillus licheniformis.  

Science.gov (United States)

The environmental bacterium Bacillus licheniformis was transformed with two different shuttle-vectors (pCSS810 and pGFPratiometric) containing insect luciferase and green fluorescent protein genes, respectively. The cells were treated with various antimicrobial agents and the emitted bioluminescence and fluorescence were measured. Plasmid harboring the green fluorescent protein gene was totally segregated without selective pressure, and fluorescent B. licheniformis showed a slower growth rate than the wild-type strain; those cells were bright green as visualized by epifluorescent microscopy. However, fluorescence was not correlated to the growth state of cells or affected by the antibiotic treatments. To the contrary, luminescent transformant was found to be stable without antibiotic selection and showed analogous growth behavior compared to non-plasmid-bearing cells. The luminescent strain functioned as a biosensor for the antibiotics employed. Bioluminescence measurements allowed one to determine the viability of the recombinant cells and the kinetics of the antibacterial action could be followed. Thus, the light emission was found to be a reliable, sensitive, and real-time indicator of the "well-being" of cells, whereas fluorescence allowed one to visualize both metabolically active and inactive cells. PMID:18574629

Tamagnini, Isabella; Guglielmetti, Simone; Mora, Diego; Parini, Carlo; Canzi, Enrica; Karp, Matti

2008-06-24

204

Generation and comparison of bioluminescent and fluorescent Bacillus licheniformis.  

UK PubMed Central (United Kingdom)

The environmental bacterium Bacillus licheniformis was transformed with two different shuttle-vectors (pCSS810 and pGFPratiometric) containing insect luciferase and green fluorescent protein genes, respectively. The cells were treated with various antimicrobial agents and the emitted bioluminescence and fluorescence were measured. Plasmid harboring the green fluorescent protein gene was totally segregated without selective pressure, and fluorescent B. licheniformis showed a slower growth rate than the wild-type strain; those cells were bright green as visualized by epifluorescent microscopy. However, fluorescence was not correlated to the growth state of cells or affected by the antibiotic treatments. To the contrary, luminescent transformant was found to be stable without antibiotic selection and showed analogous growth behavior compared to non-plasmid-bearing cells. The luminescent strain functioned as a biosensor for the antibiotics employed. Bioluminescence measurements allowed one to determine the viability of the recombinant cells and the kinetics of the antibacterial action could be followed. Thus, the light emission was found to be a reliable, sensitive, and real-time indicator of the "well-being" of cells, whereas fluorescence allowed one to visualize both metabolically active and inactive cells.

Tamagnini I; Guglielmetti S; Mora D; Parini C; Canzi E; Karp M

2008-09-01

205

Rapid bacteriological screening of cosmetic raw materials by using bioluminescence.  

UK PubMed Central (United Kingdom)

Incoming cosmetic raw materials are routinely tested for microbial content. Standard plate count methods require up to 72 h. A rapid, sensitive, and inexpensive raw material screening method was developed that detects the presence of bacteria by means of ATP (bioluminescence). With a 24-h broth enrichment, the minimum bacterial ATP detection threshold of 1 cfu/g sample can be achieved using purified firefly luciferin-luciferase and an ATP releasing reagent. By using this rapid screen, microbiologically free material may be released for production within 24 h, while contaminated material undergoes further quantitative and identification testing. In order for a raw material to be validated for this method it must be evaluated for (1) a potential nonmicrobial light-contributing reaction resulting in a false positive or, (2) degradation of the ATP giving a false negative, and (3) confirmation that the raw material has not overwhelmed the buffering capacity of the enrichment broth. The key criteria for a rapid screen was the sensitivity to detect less than one colony forming unit per g product, the speed to do this within 24 h, and cost efficiency. Bioluminescence meets these criteria. With an enrichment step, it can detect less than one cfu/g sample. After the enrichment step, analysis time per sample is approximately 2 min and the cost for material and reagents is less than one dollar per sample.

Nielsen P; Van Dellen E

1989-09-01

206

Dinoflagellate bioluminescence: a comparative study of invitro components.  

UK PubMed Central (United Kingdom)

In vitro bioluminescence components of the dinoflagellates Gonyaulax polyedra, G. tamarensis, Dissodinium lunual, and Pyrocystis noctiluca were studied. The luciferases and luciferins of the four species cross-react in all combinations. All of these species possess high-molecular weight luciferases (200,000-400,000 daltons) with similar pH activity profiles. The active single chains of luciferases from the Gonyaulax species have a MW of 130,000 while those from P. noctiluca and D. lunula have a MW of 60,000. Extractable luciferase activity varies with time of day in the two Gonyaulax species, but not in the other two. A luciferin binding protein (LBP) can easily be extracted from the two Gonyaulax species (MW approximately 120,000 daltons), but none could be detected in extracts of either D. lunula or P. noctiluca. Scintillons are extractable from all four species, but they vary in density and the degree to which activity can be increased by added luciferin. Although the biochemistry of bioluminescence in these dinoflagellates is generally similar, the observations that D. lunula and P. noctiluca apparently lack LBP and have luciferases with low MW single chains require further clarification.

Schmitter RE; Njus D; Sulzman FM; Gooch VD; Hastings JW

1976-01-01

207

Dinoflagellate bioluminescence: a comparative study of invitro components.  

Science.gov (United States)

In vitro bioluminescence components of the dinoflagellates Gonyaulax polyedra, G. tamarensis, Dissodinium lunual, and Pyrocystis noctiluca were studied. The luciferases and luciferins of the four species cross-react in all combinations. All of these species possess high-molecular weight luciferases (200,000-400,000 daltons) with similar pH activity profiles. The active single chains of luciferases from the Gonyaulax species have a MW of 130,000 while those from P. noctiluca and D. lunula have a MW of 60,000. Extractable luciferase activity varies with time of day in the two Gonyaulax species, but not in the other two. A luciferin binding protein (LBP) can easily be extracted from the two Gonyaulax species (MW approximately 120,000 daltons), but none could be detected in extracts of either D. lunula or P. noctiluca. Scintillons are extractable from all four species, but they vary in density and the degree to which activity can be increased by added luciferin. Although the biochemistry of bioluminescence in these dinoflagellates is generally similar, the observations that D. lunula and P. noctiluca apparently lack LBP and have luciferases with low MW single chains require further clarification. PMID:1400

Schmitter, R E; Njus, D; Sulzman, F M; Gooch, V D; Hastings, J W

1976-01-01

208

Real-time processing and compression of DNA microarray images.  

UK PubMed Central (United Kingdom)

In this paper, we present a pipeline architecture specifically designed to process and compress DNA microarray images. Many of the pixilated image generation methods produce one row of the image at a time. This property is fully exploited by the proposed pipeline that takes in one row of the produced image at each clock pulse and performs the necessary image processing steps on it. This will remove the present need for sluggish software routines that are considered a major bottleneck in the microarray technology. Moreover, two different structures are proposed for compressing DNA microarray images. The proposed architecture is proved to be highly modular, scalable, and suited for a standard cell VLSI implementation.

Samavi S; Shirani S; Karimi N

2006-03-01

209

Cloaking and imaging at the same time  

CERN Multimedia

In this letter, we propose a conceptual device to perform subwavelength imaging with positive refraction. The key to this proposal is that a drain is no longer a must for some cases. What's more, this device is an isotropic omnidirectional cloak with a perfect electric conductor hiding region and shows versatile illusion optical effects. Numerical simulations are performed to verify the functionalities.

Wu, Qiannan; Chen, Huanyang

2012-01-01

210

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 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

2007-01-01

211

A Monte-Carlo-Based Network Method for Source Positioning in Bioluminescence Tomography  

Directory of Open Access Journals (Sweden)

Full Text Available We present an approach based on the improved Levenberg Marquardt (LM) algorithm of backpropagation (BP) neural network to estimate the light source position in bioluminescent imaging. For solving the forward problem, the table-based random sampling algorithm (TBRS), a fast Monte Carlo simulation method we developed before, is employed here. Result shows that BP is an effective method to position the light source.

Zhun Xu; Xiaolei Song; Xiaomeng Zhang; Jing Bai

2007-01-01

212

Method of optical image coding by time integration  

Science.gov (United States)

Method of optical image coding by time integration is proposed. Coding in proposed method is accomplished by shifting object image over photosensor area of digital camera during registration. It results in optically calculated convolution of original image with shifts trajectory. As opposed to optical coding methods based on the use of diffractive optical elements the described coding method is feasible for implementation in totally incoherent light. The method was preliminary tested by using LC monitor for image displaying and shifting. Shifting of object image is realized by displaying video consisting of frames with image to be encoded at different locations on screen of LC monitor while registering it by camera. Optical encoding and numerical decoding of test images were performed successfully. Also more practical experimental implementation of the method with use of LCOS SLM Holoeye PLUTO VIS was realized. Objects images to be encoded were formed in monochromatic spatially incoherent light. Shifting of object image over camera photosensor area was accomplished by displaying video consisting of frames with blazed gratings on LCOS SLM. Each blazed grating deflects reflecting from SLM light at different angle. Results of image optical coding and encoded images numerical restoration are presented. Obtained experimental results are compared with results of numerical modeling. Optical image coding with time integration could be used for accessible quality estimation of optical image coding using diffractive optical elements or as independent optical coding method which can be implemented in incoherent light.

Evtikhiev, Nikolay N.; Starikov, Sergey N.; Cheryomkhin, Pavel A.; Krasnov, Vitaly V.; Rodin, Vladislav G.

2012-05-01

213

Real-time handheld multispectral optoacoustic imaging.  

UK PubMed Central (United Kingdom)

Multispectral optoacoustic tomography (MSOT) of functional and molecular contrast has the potential to find broad deployment in clinical practice. We have developed the first handheld MSOT imaging device with fast wavelength tuning achieving a frame rate of 50 Hz. In this Letter, we demonstrate its clinical potential by dynamically resolving multiple disease-relevant tissue chromophores, including oxy-/deoxyhemoglobin, and melanin, in human volunteers.

Buehler A; Kacprowicz M; Taruttis A; Ntziachristos V

2013-05-01

214

Real-time handheld multispectral optoacoustic imaging.  

Science.gov (United States)

Multispectral optoacoustic tomography (MSOT) of functional and molecular contrast has the potential to find broad deployment in clinical practice. We have developed the first handheld MSOT imaging device with fast wavelength tuning achieving a frame rate of 50 Hz. In this Letter, we demonstrate its clinical potential by dynamically resolving multiple disease-relevant tissue chromophores, including oxy-/deoxyhemoglobin, and melanin, in human volunteers. PMID:23632499

Buehler, Andreas; Kacprowicz, Marcin; Taruttis, Adrian; Ntziachristos, Vasilis

2013-05-01

215

Cell-based bioluminescence screening assays.  

UK PubMed Central (United Kingdom)

Drug screening is an essential and widely used technique for drug discovery in various biomedical fields notably in oncology. Here we describe a functional screening assay based on the bioluminescence detection of a secreted luciferase for monitoring cell viability of cancer cells in a high-throughput format. This assay allows the screening of large libraries comprising thousands of compounds and the identification of potential anticancer molecules in a rapid, facile, and cost-effective manner.

Amante RJ; Badr CE

2014-01-01

216

BIOGLYPHS: A Living Collaboration with Bioluminescent Organisms  

Science.gov (United States)

BIOGLYPHS is an art and science collaboration initiated by members of the Center for Biofilm Engineering and the Montana State University School of Art. This website features two BIOGLYPHS exhibitions of living bioluminescent paintings that were created by teams of student and staff artists, scientists and engineers in 2002. The site includes a gallery of BIOGLYPH paintings, information about collaborators, comments from the guest book, and links to media coverage and related web pages.

Art, Msu-Bozeman S.; Engineering, Center F.

217

Bioluminescent assays for cytochrome P450 enzymes.  

UK PubMed Central (United Kingdom)

The cytochrome P450 (CYP) family contains 57 enzymes in humans. The activity of CYPs against xenobiotics is a primary consideration in drug optimization efforts. Here we describe a series of bioluminescent assays that enable the rapid profiling of CYP activity against compound collections. The assays employ a coupled-enzyme format where firefly luciferase is used to measure CYP enzyme activity through metabolism of pro-luciferase substrates.

Auld DS; Veith H; Cali JJ

2013-01-01

218

Real-Time Image Mosaicing From A Video Sequence  

UK PubMed Central (United Kingdom)

This paper describes a fast and robust image registrationmethod that can be used to create a panoramicimage/video from video sequences. To estimate alignmentparameters for image registration, the methodcomputes pseudo motion vectors that are rough estimatesof optical flows at each selected pixels. Usingthe proposed method, we implemented a software systemthat can, with a low-cost PC, create and displaypanoramic images/videos in real-time.1. INTRODUCTIONCreating panoramic images from video sequences isuseful for many applications such as image browsing[8], video surveillance [1] and virtual reality [3][7]. Itsreal-time processing is of great significance because itenables video mosaicing to be performed without accumulatingvideo sequences and it enables online user tospecify the way that panoramic images are created. Italso enables us to create a panoramic image on whichlive video frames are overlaid. Such panoramic videosare very suitable for presentation of a wide...

Masakatsu Kourogi; Takeshi Kurata

219

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

1982-01-01

220

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

 
 
 
 
221

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

1978-05-16

222

Digital Image Processing: An Overview of Computational Time Requirement.  

Directory of Open Access Journals (Sweden)

Full Text Available Image processing is a growing field covering a wide range of techniques for the manipulation of digital images [1].Many image processing tasks can be characterized as being computationally intensive. One reason for this is the vast amount of data that requires processing, more than seven million pixels per second for typical image sources. To keep up with these data rates and demanding computations in real-time, the processing engine must provide specialized data paths, application-specific operators, creative data management, and careful sequencing and pipelining. The paper is confined to the major drawback of digital image processing which is the computational time required and is also said to be the computational power of a digital image processing system.

Ahaiwe J

2013-01-01

223

In vivo quantitative bioluminescence tomography using heterogeneous and homogeneous mouse models  

Science.gov (United States)

Bioluminescence tomography (BLT) is a new optical molecular imaging modality, which can monitor both physiological and pathological processes by using bioluminescent light-emitting probes in small living animal. Especially, this technology possesses great potential in drug development, early detection, and therapy monitoring in preclinical settings. In the present study, we developed a dual modality BLT prototype system with Micro-computed tomography (MicroCT) registration approach, and improved the quantitative reconstruction algorithm based on adaptive hp finite element method (hp-FEM). Detailed comparisons of source reconstruction between the heterogeneous and homogeneous mouse models were performed. The models include mice with implanted luminescence source and tumor-bearing mice with firefly luciferase report gene. Our data suggest that the reconstruction based on heterogeneous mouse model is more accurate in localization and quantification than the homogeneous mouse model with appropriate optical parameters and that BLT allows super-early tumor detection in vivo based on tomographic reconstruction of heterogeneous mouse model signal.

Liu, Junting; Wang, Yabin; Qu, Xiaochao; Li, Xiangsi; Ma, Xiaopeng; Han, Runqiang; Hu, Zhenhua; Chen, Xueli; Sun, Dongdong; Zhang, Rongqing; Chen, Duofang; Chen, Dan; Chen, Xiaoyuan; Liang, Jimin; Cao, Feng; Tian, Jie

2010-01-01

224

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

225

Real-time neutron coded aperture imaging: A technique for nondestructive three-dimensional imaging  

Energy Technology Data Exchange (ETDEWEB)

Neutron Coded Aperture Imaging is a nondestructive imaging technique that utilizes neutrons scattered from an object through specially designed apertures. Coded Aperture Imaging is an alternative technique to Computed Tomography for three-dimensional imaging. Coded Aperture Imaging has the advantage that all of the three-dimensional information is contained in a single image, whereas Computed Tomography requires several images or projections. This technique has been implemented by other using photographic film as an image recording medium and optical reconstruction or decoding of the images. In this work, the possibility of using a real-time neutron video camera to record the images, followed by digital decoding methodology has been investigated. Because only a small fraction of the neutrons incident on the object are scattered to the neutron camera, a new neutron beamport facility, with a larger neutron flux (7.3 x 10[sup 7] n/cm[sup 2]/s) than the previous facility was constructed. A real-time imaging system has been assembled that also allows for image integration directly on the video tube for low flux applications. A technique for aperture fabrication has been developed. This technique utilizes vapor deposition of neutron absorbing material (Gadolinium) onto a substrate followed by photolithographic etching of the coded aperture pattern. Various method for digital decoding have been examined including a novel use of the Wiener filter for direct image decoding. These methods have been successfully implemented on simulated images to insure that they function properly. Algorithms for decoding multiple planes to exploit the three-dimensional information have been developed and tested. In addition, a method to remove the contributions due to out-of-focus planes from a given reconstructed or decoded image was developed. Coded images were successfully recorded using the real-time imaging system with integration times of approximately 5 minutes.

Gibbs, K.M.

1992-01-01

226

Real-time adaptive radiometric correction for imaging radars systems  

Science.gov (United States)

A new solution is given of a real time radiometric image correction that also minimizes the quantization and saturation noise introduced by the process of analog-to-digital conversion of raw data of coherent and noncoherent imaging radar systems. The implementation of this procedure was successfully performed with the experimental SAR System (E-SAR) of the DLR.

Moreira, Joao R.; Poetzsch, Winfried

1989-10-01

227

Real Time Blood Testing Using Quantitative Phase Imaging  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 extrac...

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

228

Dinoflagellate bioluminescence in response to mechanical stimuli in water flows  

Science.gov (United States)

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.

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

2005-02-01

229

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; P. Le Gal

2005-01-01

230

Image reconstruction in PET using time of flight information  

International Nuclear Information System (INIS)

[en] Recent progresses in fast time coincidence technique have permitted the use of time of flight (TOF) information in positron Emission Tomography. We describe the basic concept of positron time of flight imaging and introduce new concepts in order to incorporate the TOF data in the reconstruction process. An algorithm to recover positron activity is then proposed. We describe the image reconstruction in the TTVO1 time of flight camera, the system architecture and the special purpose operators. The time of flight tomography offers large development possibilities and we look forward the new high resolution, high signal-to-noise TOF camera

1984-01-01

231

Real time K-edge subtraction x-ray imaging  

International Nuclear Information System (INIS)

This paper describes an x-ray K-edge subtraction television system for noninvasive angiography utilizing synchrotron radiation. The phantom, including contrast material (iodine), is irradiated by monochromatized dual-energy x-ray flux, alternately, using a high speed monochromator. The monochromator consists of a silicon crystal plate vibrating at 15 Hz so that the phantom is irradiated by the x-ray flux of 150 eV above and below the K-edge photon energy of iodine, 15 times per second. As an x-ray detector, TV cameras optically coupled to an x-ray image intensifier are used and the video signal is processed to display the subtraction image of pairs of successive images in real time. This system was fully implemented and moving phantoms were examined. Both the time interval between the energy change and the exposure time of each image has been shortened to 2 ms.

1989-01-01

232

Rapid time-gated polarimetric Stokes imaging using photoelastic modulators.  

UK PubMed Central (United Kingdom)

We report a rapid time-gated full Stokes imaging approach without mechanically moving parts, which is well-suited for biomedical applications, using two photoelastic modulators (PEMs). A charge-coupled device (CCD) with microsecond time-gating capability was used to acquire the images. To synchronize the CCD with the PEMs, thus gaining signal-to-noise ratio advantage, a field programmable gate array was employed. After calibration, an evolutionary algorithm was used to select four time points from which the full Stokes vector can be recovered. Using the images taken by the camera at these four times (in ?80??ms), the images of the full Stokes vectors of different incident polarization states were accurately derived.

Alali S; Yang T; Vitkin IA

2013-08-01

233

Real-time movie image enhancement in NMR  

Energy Technology Data Exchange (ETDEWEB)

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.

Doyle, M.; Mansfield, P.

1986-06-01

234

Velocity map imaging in time of flight mass spectrometry  

International Nuclear Information System (INIS)

A new variation on time of flight mass spectrometry is presented, which uses a fast framing charge coupled device camera to velocity map image multiple product masses in a single acquisition. The technique is demonstrated on two photofragmentation processes, those of CS2 and CH3S2CH3 (dimethyldisulfide) at a photolysis wavelength of 193 nm. In both cases, several mass fragments are imaged simultaneously, and speed distributions and anisotropy parameters are extracted that are comparable to those obtained by imaging each fragment separately in conventional velocity map imaging studies.

2008-01-01

235

Velocity map imaging in time of flight mass spectrometry  

Science.gov (United States)

A new variation on time of flight mass spectrometry is presented, which uses a fast framing charge coupled device camera to velocity map image multiple product masses in a single acquisition. The technique is demonstrated on two photofragmentation processes, those of CS2 and CH3S2CH3 (dimethyldisulfide) at a photolysis wavelength of 193 nm. In both cases, several mass fragments are imaged simultaneously, and speed distributions and anisotropy parameters are extracted that are comparable to those obtained by imaging each fragment separately in conventional velocity map imaging studies.

Brouard, M.; Campbell, E. K.; Johnsen, A. J.; Vallance, C.; Yuen, W. H.; Nomerotski, A.

2008-12-01

236

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).

1986-01-01

237

Detection of dichloromethane with a bioluminescent (lux) bacterial bioreporter.  

UK PubMed Central (United Kingdom)

The focus of this research effort was to develop an autonomous, inducible, lux-based bioluminescent bioreporter for the real-time detection of dichloromethane. Dichloromethane (DCM), also known as methylene chloride, is a volatile organic compound and one of the most commonly used halogenated solvents in the U.S., with applications ranging from grease and paint stripping to aerosol propellants and pharmaceutical tablet coatings. Predictably, it is released into the environment where it contaminates air and water resources. Due to its classification as a probable human carcinogen, hepatic toxin, and central nervous system effector, DCM must be carefully monitored and controlled. Methods for DCM detection usually rely on analytical techniques such as solid-phase microextraction (SPME) and capillary gas chromatography or photoacoustic environmental monitors, all of which require trained personnel and/or expensive equipment. To complement conventional monitoring practices, we have created a bioreporter for the self-directed detection of DCM by taking advantage of the evolutionary adaptation of bacteria to recognize and metabolize chemical agents. This bioreporter, Methylobacterium extorquens DCM( lux ), was engineered to contain a bioluminescent luxCDABE gene cassette derived from Photorhabdus luminescens fused downstream to the dcm dehalogenase operon, which causes the organism to generate visible light when exposed to DCM. We have demonstrated detection limits down to 1.0 ppm under vapor phase exposures and 0.1 ppm under liquid phase exposures with response times of 2.3 and 1.3 h, respectively, and with specificity towards DCM under relevant industrial environmental monitoring conditions.

Lopes N; Hawkins SA; Jegier P; Menn FM; Sayler GS; Ripp S

2012-01-01

238

Influence of the temperature at the Black Sea ctenophores-aliens bioluminescence characteristics  

Directory of Open Access Journals (Sweden)

Full Text Available Successful invasion of Mnemiopsis leidyi A. Agassiz, 1865 and Beroe ovata Mayer, 1912 into the Black Sea and their important role in this region pelagic ecosystem is stipulated mainly by the considerable eurythermy of these species. Many ecological-physiological characteristics of ctenophores—aliens are studied quite well. However, bioluminescence, one of the most important elements of the ctenophores ecology and the bioluminescence reaction temperature optimum for these individuals under different environment temperatures were not studied sufficiently. Therefore our researches in this scientific field are significant and conceptually novel for ctenophores ecology study. Experimental investigations were carried out in the period of 2008-2009 in the IBSS. Uni-sized (40 mm) ctenophores were collected in the Sevastopol coastal zone and divided in several groups, contained under different temperatures: from 10°C ± 1°C to 30°C ± 1°C. Ctenophore bioluminescence was investigated under chemical and mechanical stimulation. M. leidyi light emission maximal amplitude (1432.94 ± 71.64 × 108 quantum·s–1·cm–2) with duration of 3.54 ± 0.15 s is fixed under the temperature of 26°C ± 1°C. Temperature increase up to 30°C ± 1°C led to the 4 times decrease of the bioluminescence intensity. Under temperature decrease up to 10°C ± 1°C this parameter decreased 20 times (p B. ovata achieved maximal values under the temperature of 22°C ± 1°C (1150.12 ± 57.51 × 108 quantum·s–1·cm–2) with duration of 3.03 ± 0.15 s. The luminescence intensity decreased under the temperature increase to 30°C ± 1°C more than 20 times. Temperature decrease to the values of 10°C ± 1°C impacted decreasing the amplitude of bioluminescence up to the minimal –4.92 ± 0.22 × 108 quantum·s–1·cm–2. The data obtained testify that characteristics of the ctenophores bioluminescence can be conditioned not only by the modification the environment temperature but by the variability of their physiological condition.

Mashukova Olga; Tokarev Yuriy

2012-01-01

239

Chemiluminescence and bioluminescence past, present and future  

CERN Multimedia

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

240

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

2000-01-01

 
 
 
 
241

Method and system for real-time facial image enhancement  

UK PubMed Central (United Kingdom)

The present invention is a system and method for detecting facial features of humans in a continuous video and superimposing virtual objects onto the features automatically and dynamically in real-time. The suggested system is named Facial Enhancement Technology (FET). The FET system consists of three major modules, initialization module, facial feature detection module, and superimposition module. Each module requires demanding processing time and resources by nature, but the FET system integrates these modules in such a way that real time processing is possible. The users can interact with the system and select the objects on the screen. The superimposed image moves along with the user's random motion dynamically. The FET system enables the user to experience something that was not possible before by augmenting the person's facial images.The hardware of the FET system comprises the continuous image-capturing device, image processing and controlling system, and output display system.

JUNG NAMSOON; SHARMA RAJEEV

242

Method and system for real-time facial image enhancement  

UK PubMed Central (United Kingdom)

The present invention is a system and method for detecting facial features of humans in a continuous video and super-imposing virtual objects onto the features automatically and dynamically in real-time. The suggested system is named Facial Enhancement Technology (FET). The FET system consists of three major modules, initialization module, facial feature detection module, and superimposition module. Each module requires demanding processing time and resources by nature, but the FET system integrates these modules in such a way that real time processing is possible. The users can interact with the system and select the objects on the screen. The superimposed image moves along with the user's random motion dynamically. The FET system enables the user to experience something that was not possible before by augmenting the person's facial images. The hardware of the FET system comprises the continuous image-capturing device, image processing and controlling system, and output display system.

JUNG NAMSOON; SHARMA RAJEEV

243

Improving the Image Quality of Synthetic Transmit Aperture Ultrasound Images - Achieving Real-Time In-Vivo Imaging  

DEFF Research Database (Denmark)

Synthetic transmit aperture (STA) imaging has the potential to increase the image quality of medical ultrasound images beyond the levels obtained by conventional imaging techniques (linear, phased, and convex array imaging). Currently, however, in-vivo applications of STA imaging is limited by a low signal-to-noise ratio (SNR), due to the application of a single transducer element at each emission, and higher susceptibility to tissue motion, produced by the summation of sequentially acquired low resolution images. In order to make real-time STA imaging feasible for in-vivo applications, these issues need to solved. The goal of this PhD study has been to find methods that can be used to overcome the above mentioned limitations, and hereby improve the image quality of STA imaging to a clinically desirable level, enabling real-time in-vivo STA imaging. The thesis investigates a new method to increase the SNR, which employs multi-element subapertures and linearly frequency modulated (FM) signals at each emission.The subaperture is applied to emulate a high power spherical wave transmitted by a virtual point source positioned behind the subaperture, and the linear FM signal replaces the conventional short excitation signal to increase the transmitted temporal energy. This approach, named Temporally encoded Multi-element Synthetic transmit aperture (TMS) imaging, is evaluated in detail for linear array and convex array imaging applications using simulations, and phantom and in-vivo experiments. The thesis contains summaries of four journal articles and four corresponding conference publications, which comprise the primary contributions of the PhD. The first two papers give elaborated evaluations of TMS imaging for linear array and convex array imaging, respectively. The results, including initial in-vivo experiments, showed, that TMS imaging can increase the SNR by as much as 17 dB compared to the traditional imaging techniques, which improves the in-vivo image quality to a highly competitive level. An in-vivo evaluation of convex array TMS imaging for abdominal imaging applications is presented in the third paper, based on a clinical trial with 7 healthy male volunteers. Real-time movie sequences of 3 seconds duration were acquired and analyzed by experienced medical doctors using blinded clinical evaluation. The results showed a statistically significant improvement in image quality of convex array TMS imaging compared to conventional convex array imaging. Only minor motion artifacts causing subtle image brightness fluctuations were reported in TMS imaging, which did not depreciate the diagnostic value of the images. The influence of tissue motion and a method for two-dimensional motion compensation is investigated in the fourth and final paper. The method estimates the tissue velocity and motion vii Abstract direction at each image point by correlating image lines beamformed along a set of motion directions and selects the direction and velocity corresponding to the highest correlation. Using these estimates, motion compensation is obtained by tracking the location of each pixel, when reconstructing the low resolution images. The presented phantom and in-vivo results showed, that severe tissue motion has a negative influence on the image quality of STA imaging as expected, but, most importantly, that the proposed method successfully compensates for the motion, thus, retaining the image quality of TMS imaging, when scanning moving tissue. In conclusion, the results of the research presented in this thesis have demonstrated, that TMS imaging is feasible for real-time in-vivo imaging, and that the obtained image quality is highly competitive with the techniques applied in current medical ultrasound scanners. Hereby, the goals of the PhD have been successfully achieved.

Gammelmark, Kim

2004-01-01

244

Transmission mode time-reversal super-resolution imaging.  

Science.gov (United States)

The theory of time-reversal super-resolution imaging of point targets embedded in a reciprocal background medium [A. J. Devaney, "Super-resolution imaging using time-reversal and MUSIC," J. Acoust. Soc. Am. (to be published)] is generalized to the case where the transmitter and receiver sensor arrays need not be coincident and for cases where the background medium can be nonreciprocal. The new theory developed herein is based on the singular value decomposition of the generalized multistatic data matrix of the sensor system rather than the standard eigenvector/eigenvalue decomposition of the time-reversal matrix as was employed in the above-mentioned work and other treatments of time-reversal imaging [Prada, Thomas, and Fink, "The iterative time reversal process: Analysis of the convergence," J. Acoust. Soc. Am. 97, 62 (1995); Prada et al., "Decomposition of the time reversal operator: Detection and selective focusing on two scatterers," J. Acoust. Soc. Am. 99, 2067 (1996)]. A generalized multiple signal classification (MUSIC) algorithm is derived that allows super-resolution imaging of both well-resolved and non-well-resolved point targets from arbitrary sensor array geometries. MUSIC exploits the orthogonal nature of the scatterer and noise subspaces defined by the singular vectors of the multistatic data matrix to form scatterer images. The time-reversal/MUSIC algorithm is tested and validated in two computer simulations of offset vertical seismic profiling where the sensor sources are aligned along the earth's surface and the receiver array is aligned along a subsurface borehole. All results demonstrate the high contrast, high resolution imaging capabilities of this new algorithm combination when compared with "classical" backpropagation or field focusing. Above and beyond the application of seismo-acoustic imaging, the time-reversal super-resolution theory has applications in ocean acoustics for target location, and ultrasonic nondestructive evaluation of parts. PMID:12765392

Lehman, Sean K; Devaney, Anthony J

2003-05-01

245

Transmission mode time-reversal super-resolution imaging.  

UK PubMed Central (United Kingdom)

The theory of time-reversal super-resolution imaging of point targets embedded in a reciprocal background medium [A. J. Devaney, "Super-resolution imaging using time-reversal and MUSIC," J. Acoust. Soc. Am. (to be published)] is generalized to the case where the transmitter and receiver sensor arrays need not be coincident and for cases where the background medium can be nonreciprocal. The new theory developed herein is based on the singular value decomposition of the generalized multistatic data matrix of the sensor system rather than the standard eigenvector/eigenvalue decomposition of the time-reversal matrix as was employed in the above-mentioned work and other treatments of time-reversal imaging [Prada, Thomas, and Fink, "The iterative time reversal process: Analysis of the convergence," J. Acoust. Soc. Am. 97, 62 (1995); Prada et al., "Decomposition of the time reversal operator: Detection and selective focusing on two scatterers," J. Acoust. Soc. Am. 99, 2067 (1996)]. A generalized multiple signal classification (MUSIC) algorithm is derived that allows super-resolution imaging of both well-resolved and non-well-resolved point targets from arbitrary sensor array geometries. MUSIC exploits the orthogonal nature of the scatterer and noise subspaces defined by the singular vectors of the multistatic data matrix to form scatterer images. The time-reversal/MUSIC algorithm is tested and validated in two computer simulations of offset vertical seismic profiling where the sensor sources are aligned along the earth's surface and the receiver array is aligned along a subsurface borehole. All results demonstrate the high contrast, high resolution imaging capabilities of this new algorithm combination when compared with "classical" backpropagation or field focusing. Above and beyond the application of seismo-acoustic imaging, the time-reversal super-resolution theory has applications in ocean acoustics for target location, and ultrasonic nondestructive evaluation of parts.

Lehman SK; Devaney AJ

2003-05-01

246

[A technology of real-time image compression for convex grating imaging spectrometer].  

Science.gov (United States)

The huge amount of convex grating imaging spectrometer image data brings much pressure to data transmission and storage, so the image must be compressed in real time. Firstly, the image characteristics were analyzed according to the imaging principle, and the compression approach to removing spatial correlation and spectral correlation was achieved; Secondly, the compression algorithms were analyzed and the 3-D compression scheme of one-order linear compression in spectral dimension and JPEG2000 compression in spatial dimension was proposed. Finally, a real-time compression system based on FPGA and ADV212 was designed, in which FPGA was used for logic control and implementation of prediction algorithm, and ADV212 was used for JPEG2000 compression. The analysis result shows that the system has the ability of lossless and lossy compression, enabling real-time image compression. PMID:22715801

Liu, Yang-chuan; Bayanheshig; Cui, Ji-cheng; Tang, Yu-guo

2012-04-01

247

[A technology of real-time image compression for convex grating imaging spectrometer].  

UK PubMed Central (United Kingdom)

The huge amount of convex grating imaging spectrometer image data brings much pressure to data transmission and storage, so the image must be compressed in real time. Firstly, the image characteristics were analyzed according to the imaging principle, and the compression approach to removing spatial correlation and spectral correlation was achieved; Secondly, the compression algorithms were analyzed and the 3-D compression scheme of one-order linear compression in spectral dimension and JPEG2000 compression in spatial dimension was proposed. Finally, a real-time compression system based on FPGA and ADV212 was designed, in which FPGA was used for logic control and implementation of prediction algorithm, and ADV212 was used for JPEG2000 compression. The analysis result shows that the system has the ability of lossless and lossy compression, enabling real-time image compression.

Liu YC; Bayanheshig; Cui JC; Tang YG

2012-04-01

248

Exploration time of static images implying different body movements causes time distortions.  

UK PubMed Central (United Kingdom)

Studies of subjective time have adopted different methods to understand different processes of time perception. Four sculptures, with implied movement ranked as 1.5-, 3.0-, 4.5-, and 6.0-point stimuli on the Body Movement Ranking Scale, were randomly presented to 42 university students untrained in visual arts and ballet. Participants were allowed to observe the images for any length of time (exploration time) and, immediately after each image was observed, recorded the duration as they perceived it. The results of temporal ratio (exploration time/time estimation) showed that exploration time of images also affected perception of time, i.e., the subjective time for sculptures representing implied movement were overestimated.

Nather FC; Bueno JL

2012-08-01

249

TD-DFT/molecular mechanics study of the Photinus pyralis bioluminescence system.  

UK PubMed Central (United Kingdom)

This is the first report of a computational study of the bioluminescence of ligand-bound Photinus pyralis luciferase. A time-dependent PBE0/molecular mechanics approach was used to study the interaction between excited-state oxyluciferin (Keto-(-1)) and neighboring active site molecules. The results of these calculations demonstrated that the most important intermolecular interactions are: blue-shifting ionic interactions, red-shifting ?-? stacking, and red/blue shifting hydrogen bonding. Subsequent molecular dynamics simulations further supported these conclusions.

Pinto da Silva L; Esteves da Silva JC

2012-02-01

250

Real-time time-domain fluorescence lifetime imaging including single-shot acquisition with a segmented optical image intensifier  

International Nuclear Information System (INIS)

High-speed (video-rate) fluorescence lifetime imaging (FLIM) is reported using two different time-domain approaches based on gated optical image intensifier technology. The first approach utilizes a rapidly switchable variable delay generator with sequential image acquisition, while the second employs a novel segmented gated optical imager to acquire lifetime maps in a single shot. Lifetimes are fitted using both a non-linear least-squares fit analysis and the rapid lifetime determination method. Monte Carlo simulations were used to optimize the acquisition parameters and a comparison between theory and experiment is presented. The importance of single-shot imaging to minimize the deleterious impact of sample movements is highlighted. Real-time FLIM movies of multi-well plate samples and tissue autofluorescence are presented.

2004-11-01

251

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.

K.Ramírez-Amáro; J. C. Chimal-Eguía

2012-01-01

252

Construction of a bioluminescent reporter strain to detect polychlorinated biphenyls  

Energy Technology Data Exchange (ETDEWEB)

A bioluminescent reporter strain, Ralstonia eutropha ENV307 (pUTK60), was constructed for the detection of polychlorinated biphenyls by inserting the biphenyl promoter upstream of the bioluminescence genes. In the presence of a nonionic surfactant, which enhances the solubility of chlorinated biphenyls, bioluminescence was induced three- to fourfold over background by biphenyl, monochlorinated biphenyls, and Aroclor 1242. The minimum detection limits for these compounds ranged from 0.15 mg/liter for 4-chlorobiphenyl to 1.5 mg/liter for Aroclor 1242.

Layton, A.C.; Muccini, M.; Ghosh, M.M.; Sayler, G.S. [Univ. of Tennessee, Knoxville, TN (United States)

1998-12-01

253

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

UK PubMed Central (United Kingdom)

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 < 0.05) higher 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 < 0.05) of 18F-FEAU than fluorine-18-labeled 9-(4-fluoro-3-hydroxymethylbutyl)guanine. This improved triple fusion reporter vector will enable high sensitivity detection of lower numbers of cells from living animals using the combined bioluminescence, fluorescence, and microPET imaging techniques.

Ray P; Tsien R; Gambhir SS

2007-04-01

254

A robust technique for real-time image match  

Science.gov (United States)

In the field of computer vision, image match is one of the most important research topics. It is used to match two or more images, for example, at different time, from different sensors or from different viewpoints. In this paper, we present a robust method for realtime image registration. First, the feature points of two images were obtained by using Adaptive Harris detector, and the matching points of the two images are determined by using global search. And then the maximum correlation principle is involved to adaptively determine the optimal affine transformation parameters. In the stage of real-time video image registration, we can determine the searching area for the related feature points in the current frame using the affine transformation matrix between the reference image and the previous frame, which enables the matching method effective. The experimental results showed that the presented method achieved 25fps, which is fast enough, and the registration errors are small enough demonstrating the high precision of the proposed registration method.

Su, Bin; Mi, Fengwen

2013-03-01

255

Real-Time Analysis of Large Astronomical Images  

CERN Document Server

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 to support such surveys, focusing particularly on ImageHealth, a tool for near-real-time processing of large images. These image manipulation and analysis algorithms were applied to simulated data from the Dark Energy Survey, as well as observed data collected by the Y4KCam on the CTIO 1m telescope and the Mosaic camera on the Blanco telescope. The accuracy and speed of the ImageHealth code in particular were benchmarked against results from SourceExtractor, a standard image analysis tool ubiquitous in the astronomical community. ImageHeal...

Kuehn, K

2012-01-01

256

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

257

Prospects for Electron Imaging with Ultrafast Time Resolution  

Energy Technology Data Exchange (ETDEWEB)

Many pivotal aspects of material science, biomechanics, and chemistry would benefit from nanometer imaging with ultrafast time resolution. Here we demonstrate the feasibility of short-pulse electron imaging with t10 nanometer/10 picosecond spatio-temporal resolution, sufficient to characterize phenomena that propagate at the speed of sound in materials (1-10 kilometer/second) without smearing. We outline resolution-degrading effects that occur at high current density followed by strategies to mitigate these effects. Finally, we present a model electron imaging system that achieves 10 nanometer/10 picosecond spatio-temporal resolution.

Armstrong, M R; Reed, B W; Torralva, B R; Browning, N D

2007-01-26

258

[Effect of surface-active substances on bioluminescence intensity of bacteria  

UK PubMed Central (United Kingdom)

The study of sensitivity of luminous bacteria isolated from the Black and Azov seas to surfactants from various classes was carried out. It was shown that cationic surfactants had a strong inhibition effect on bacterial luminescence in contrast to anionic and in particular nonionic surfactants. To increase the luminous bacteria sensitivity to the action of OP-10 (nonionic surfactant) and ABS (anionic surfactant), which are widely used in industry, several approaches have been developed. They include modulation of bacterial sensitivity by the additives of cationic substances, use of luminous bacteria at a logarithmic stage of growth, realization of biotesting at low pH = 5.5. The use of these approaches allows to lower effective concentrations of OP-10 and ABS, which caused a decrease of bioluminescence by 50%, 3-200 times and opens perspectives for the use of the bioluminescent method to study these surfactants toxicity on the principle of biosensorics.

Katsev AM; Starodub NF

2003-03-01

259

Cumulative bioluminescence; A potential rapid test of drilling fluid toxicity: development study  

Energy Technology Data Exchange (ETDEWEB)

A new rapid test of drilling fluid toxicity is based on the spontaneous bioluminescence of Pyrocystis lunula, an easy-to-culture alga that vigorously responds to shear stress (mixing) by emitting a sharp burst of light. In contrast to other bioluminescence methods, a cumulative flux of light is measured with a photomultiplier that eliminates the effect of exposure time on test results. Light quenching, caused by the presence of a toxicant, results in the dose/response relationship (DSR) typical for the enzymatic reaction kinetics. The Michaelis-Menten (dissociation) constant is used as a direct measure of toxicity. The evaluation study involved multiple experiments with 60 samples of drilling fluids from the U.S. gulf coast, as well as such typical toxicants as diesel oil, mineral oil, and chrome lignosulfonate (CLS). In this paper, the results of the test error analysis and comparisons with the Microtox and Mysid shrimp assays are reported.

Stiffey, A.V. (Naval Oceanographic and Atmospheric Research Lab. (US))

1992-03-01

260

Time-resolved imaging of solid phantoms for optical mammography.  

UK PubMed Central (United Kingdom)

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.

Grosenick D; Wabnitz H; Rinneberg H

1997-01-01

 
 
 
 
261

Real-time optical motion correction for diffusion tensor imaging.  

Science.gov (United States)

Head motion is a fundamental problem in brain MRI. The problem is further compounded in diffusion tensor imaging because of long acquisition times, and the sensitivity of the tensor computation to even small misregistration. To combat motion artifacts in diffusion tensor imaging, a novel real-time prospective motion correction method was introduced using an in-bore monovision system. The system consists of a camera mounted on the head coil and a self-encoded checkerboard marker that is attached to the patient's forehead. Our experiments showed that optical prospective motion correction is more effective at removing motion artifacts compared to image-based retrospective motion correction. Statistical analysis revealed a significant improvement in similarity between diffusion data acquired at different time points when prospective correction was used compared to retrospective correction (P<0.001). PMID:21432898

Aksoy, Murat; Forman, Christoph; Straka, Matus; Skare, Stefan; Holdsworth, Samantha; Hornegger, Joachim; Bammer, Roland

2011-03-22

262

Real-time optical motion correction for diffusion tensor imaging.  

UK PubMed Central (United Kingdom)

Head motion is a fundamental problem in brain MRI. The problem is further compounded in diffusion tensor imaging because of long acquisition times, and the sensitivity of the tensor computation to even small misregistration. To combat motion artifacts in diffusion tensor imaging, a novel real-time prospective motion correction method was introduced using an in-bore monovision system. The system consists of a camera mounted on the head coil and a self-encoded checkerboard marker that is attached to the patient's forehead. Our experiments showed that optical prospective motion correction is more effective at removing motion artifacts compared to image-based retrospective motion correction. Statistical analysis revealed a significant improvement in similarity between diffusion data acquired at different time points when prospective correction was used compared to retrospective correction (P<0.001).

Aksoy M; Forman C; Straka M; Skare S; Holdsworth S; Hornegger J; Bammer R

2011-08-01

263

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

264

Segmentation of Time-Lapse Images with Focus on Microscopic Images of Cells.  

Czech Academy of Sciences Publication Activity Database

phase constrastKód oboru RIV: JD - Využití po?íta??, robotika a její aplikace http://library.utia.cas.cz/separaty/2013/ZOI/soukup-segmentation of time-lapse images with focus on microscopic images of cells.pdf

Soukup, Jind?ichG; Císa?, P.; Šroubek, Filip

265

Single photon imaging and timing array sensor apparatus and method  

Science.gov (United States)

An apparatus and method are disclosed for generating a three-dimension image of an object or target. The apparatus is comprised of a photon source for emitting a photon at a target. The emitted photons are received by a photon receiver for receiving the photon when reflected from the target. The photon receiver determines a reflection time of the photon and further determines an arrival position of the photon on the photon receiver. An analyzer is communicatively coupled to the photon receiver, wherein the analyzer generates a three-dimensional image of the object based upon the reflection time and the arrival position.

Smith, R. Clayton (Boulder, CO)

2003-06-24

266

Effect of exposure time and image resolution on fractal dimension  

International Nuclear Information System (INIS)

To evaluate the effect of exposure time and image resolution on fractal dimension calculations for determining the optimal range of these two variances. Thirty-one radiographs of the mandibular angle area of sixteen human dry mandibles were taken at different exposure times (0.01, 0.08, 0.16, 0.25, 0.40, 0.64, and 0.80 s). Each radiograph was digitized at 1200 dpi, 8 bit, 256 gray level using a film scanner. We selected an Region of Interest (ROI) that corresponded to the same region as in each radiograph, but the resolution of ROI was degraded to 1000, 800, 600, 500, 400, 300, 200, and 100 dpi. The fractal dimension was calculated by using the tile-counting method for each image, and the calculated values were then compared statistically. As the exposure time and the image resolution increased, the mean value of the fractal dimension decreased, except the case where exposure time was set at 0.01 seconds (alpha = 0.05). The exposure time and image resolution affected the fractal dimension by interaction (p

2002-01-01

267

Time reversal imaging, Inverse problems and Adjoint Tomography}  

Science.gov (United States)

With the increasing power of computers and numerical techniques (such as spectral element methods), it is possible to address a new class of seismological problems. The propagation of seismic waves in heterogeneous media is simulated more and more accurately and new applications developed, in particular time reversal methods and adjoint tomography in the three-dimensional Earth. Since the pioneering work of J. Claerbout, theorized by A. Tarantola, many similarities were found between time-reversal methods, cross-correlations techniques, inverse problems and adjoint tomography. By using normal mode theory, we generalize the scalar approach of Draeger and Fink (1999) and Lobkis and Weaver (2001) to the 3D- elastic Earth, for theoretically understanding time-reversal method on global scale. It is shown how to relate time-reversal methods on one hand, with auto-correlations of seismograms for source imaging and on the other hand, with cross-correlations between receivers for structural imaging and retrieving Green function. Time-reversal methods were successfully applied in the past to acoustic waves in many fields such as medical imaging, underwater acoustics, non destructive testing and to seismic waves in seismology for earthquake imaging. In the case of source imaging, time reversal techniques make it possible an automatic location in time and space as well as the retrieval of focal mechanism of earthquakes or unknown environmental sources . We present here some applications at the global scale of these techniques on synthetic tests and on real data, such as Sumatra-Andaman (Dec. 2004), Haiti (Jan. 2010), as well as glacial earthquakes and seismic hum.

Montagner, J.; Larmat, C. S.; Capdeville, Y.; Kawakatsu, H.; Fink, M.

2010-12-01

268

Real-time image mosaicing for medical applications.  

UK PubMed Central (United Kingdom)

In this paper we describe the development of a robotically-assisted image mosaicing system for medical applications. The processing occurs in real-time due to a fast initial image alignment provided by robotic position sensing. Near-field imaging, defined by relatively large camera motion, requires translations as well as pan and tilt orientations to be measured. To capture these measurements we use 5-d.o.f. sensing along with a hand-eye calibration to account for sensor offset. This sensor-based approach speeds up the mosaicing, eliminates cumulative errors, and readily handles arbitrary camera motions. Our results have produced visually satisfactory mosaics on a dental model but can be extended to other medical images.

Loewke KE; Camarillo DB; Jobst CA; Salisbury JK

2007-01-01

269

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,; PALLAVI CHOUDEKAR,; M.K.MUJU

2011-01-01

270

The terrestrial bioluminescent animals of Japan.  

UK PubMed Central (United Kingdom)

Light production by organisms, or bioluminescence, has fascinated not only scientists but also ordinary people all over the world, and it has been especially so in Japan. Here we review the biological information available to date for all luminous terrestrial animals known from Japan, particularly focusing on their diversity and systematics, their biology and ecology in Japan, and putative function and biochemistry of their luminescence. In total 58 luminous terrestrial animals have been described from Japan, which consist of 50 fireflies (Coleoptera: Lampyridae), one glowworm beetle (Coleoptera: Phengodidae), two fungus gnats (Diptera: Keroplatidae), one springtail (Collembola), one millipede (Diplopoda), one centipede (Chilopoda) and two earthworms (Oligochaeta). For all except some firefly species, the DNA "barcode" sequences of a cytochrome oxidase subunit I region are provided. We also introduce how intricately the seasonal appearance and glimmering of luminous insects, in particular those of fireflies, have been interwoven into the culture, art, literature and mentality of Japanese people.

Oba Y; Branham MA; Fukatsu T

2011-11-01

271

Deep-Sea Bioluminescence Blooms after Dense Water Formation at the Ocean Surface  

Science.gov (United States)

The deep ocean is the largest and least known ecosystem on Earth. It hosts numerous pelagic organisms, most of which are able to emit light. Here we present a unique data set consisting of a 2.5-year long record of light emission by deep-sea pelagic organisms, measured from December 2007 to June 2010 at the ANTARES underwater neutrino telescope in the deep NW Mediterranean Sea, jointly with synchronous hydrological records. This is the longest continuous time-series of deep-sea bioluminescence ever recorded. Our record reveals several weeks long, seasonal bioluminescence blooms with light intensity up to two orders of magnitude higher than background values, which correlate to changes in the properties of deep waters. Such changes are triggered by the winter cooling and evaporation experienced by the upper ocean layer in the Gulf of Lion that leads to the formation and subsequent sinking of dense water through a process known as “open-sea convection”. It episodically renews the deep water of the study area and conveys fresh organic matter that fuels the deep ecosystems. Luminous bacteria most likely are the main contributors to the observed deep-sea bioluminescence blooms. Our observations demonstrate a consistent and rapid connection between deep open-sea convection and bathypelagic biological activity, as expressed by bioluminescence. In a setting where dense water formation events are likely to decline under global warming scenarios enhancing ocean stratification, in situ observatories become essential as environmental sentinels for the monitoring and understanding of deep-sea ecosystem shifts.

Tamburini, Christian; Canals, Miquel; Durrieu de Madron, Xavier; Houpert, Loic; Lefevre, Dominique; Martini, Severine; D'Ortenzio, Fabrizio; Robert, Anne; Testor, Pierre; Aguilar, Juan Antonio; Samarai, Imen Al; Albert, Arnaud; Andre, Michel; Anghinolfi, Marco; Anton, Gisela; Anvar, Shebli; Ardid, Miguel; Jesus, Ana Carolina Assis; Astraatmadja, Tri L.; Aubert, Jean-Jacques; Baret, Bruny; Basa, Stephane; Bertin, Vincent; Biagi, Simone; Bigi, Armando; Bigongiari, Ciro; Bogazzi, Claudio; Bou-Cabo, Manuel; Bouhou, Boutayeb; Bouwhuis, Mieke C.; Brunner, Jurgen; Busto, Jose; Camarena, Francisco; Capone, Antonio; Carloganu, Christina; Carminati, Giada; Carr, John; Cecchini, Stefano; Charif, Ziad; Charvis, Philippe; Chiarusi, Tommaso; Circella, Marco; Coniglione, Rosa; Costantini, Heide; Coyle, Paschal; Curtil, Christian; Decowski, Patrick; Dekeyser, Ivan; Deschamps, Anne; Donzaud, Corinne; Dornic, Damien; Dorosti, Hasankiadeh Q.; Drouhin, Doriane; Eberl, Thomas; Emanuele, Umberto; Ernenwein, Jean-Pierre; Escoffier, Stephanie; Fermani, Paolo; Ferri, Marcelino; Flaminio, Vincenzo; Folger, Florian; Fritsch, Ulf; Fuda, Jean-Luc; Galata, Salvatore; Gay, Pascal; Giacomelli, Giorgio; Giordano, Valentina; Gomez-Gonzalez, Juan-Pablo; Graf, Kay; Guillard, Goulven; Halladjian, Garadeb; Hallewell, Gregory; van Haren, Hans; Hartman, Joris; Heijboer, Aart J.; Hello, Yann; Hernandez-Rey, Juan Jose; Herold, Bjoern; Hossl, Jurgen; Hsu, Ching-Cheng; de Jong, Marteen; Kadler, Matthias; Kalekin, Oleg; Kappes, Alexander; Katz, Uli; Kavatsyuk, Oksana; Kooijman, Paul; Kopper, Claudio; Kouchner, Antoine; Kreykenbohm, Ingo; Kulikovskiy, Vladimir; Lahmann, Robert; Lamare, Patrick; Larosa, Giuseppina; Lattuada, Dario; Lim, Gordon; Presti, Domenico Lo; Loehner, Herbert; Loucatos, Sotiris; Mangano, Salvatore; Marcelin, Michel; Margiotta, Annarita; Martinez-Mora, Juan Antonio; Meli, Athina; Montaruli, Teresa; Motz, Holger; Neff, Max; Nezri, Emma nuel; Palioselitis, Dimitris; Pavalas, Gabriela E.; Payet, Kevin; Payre, Patrice; Petrovic, Jelena; Piattelli, Paolo; Picot-Clemente, Nicolas; Popa, Vlad; Pradier, Thierry; Presani, Eleonora; Racca, Chantal; Reed, Corey; Riccobene, Giorgio; Richardt, Carsten; Richter, Roland; Riviere, Colas; Roensch, Kathrin; Rostovtsev, Andrei; Ruiz-Rivas, Joaquin; Rujoiu, Marius; Russo, Valerio G.; Salesa, Francisco; Sanchez-Losa, Augustin; Sapienza, Piera; Schock, Friederike; Schuller, Jean-Pierre; Schussler, Fabian; Shanidze, Rezo; Simeone, Francesco; Spies, Andreas; Spurio, Maurizio; Steijger, Jos J. M.; Stolarczyk, Thierry; Taiuti, Mauro G. F.; Toscano, Simona; Vallage, Bertrand; Van Elewyck, Veronique; Vannoni, Giulia; Vecchi, Manuela; Vernin, Pascal; Wijnker, Guus; Wilms, Jorn; de Wolf, Els; Yepes, Harold; Zaborov, Dmitry; De Dios Zornoza, Juan; Zuniga, Juan

2013-01-01

272

Real-Time Video Imaging of Protease Expression In Vivo  

Directory of Open Access Journals (Sweden)

Full Text Available We demonstrate the first true real-time in vivo video imaging of extracellular protease expression using an ultrafast-acting and extended-use activatable probe. This simple, one-step technique is capable of boosting fluorescent signals upon target protease cleavage as early as 30 minutes from injection in a small animal model and is able to sustain the strong fluorescent signal up to 24 hours. Using this method, we video imaged the expression and inhibition of matrix metalloproteinases (MMPs) in a tumor-bearing mouse model. The current platform can be universally applied to any target protease of interest with a known peptide substrate and is adaptable to a wide range of real-time imaging applications with high throughputs such as for in vivo drug screening, examinations of the therapeutic efficacy of drugs, and monitoring of disease onset and development in animal models.

Lei Zhu, Jin Xie, Magdalena Swierczewska, Fan Zhang, Qimeng Quan, Ying Ma, Xuexun Fang, Kwangmeyung Kim, Seulki Lee, Xiaoyuan Chen

2011-01-01

273

Adaptive digital image processing in real time: First clinical experiences  

International Nuclear Information System (INIS)

The promise of computer image processing has generally not been realized in radiology, partly because the methods advanced to date have been expensive, time-consuming, or inconvenient for clinical use. The authors describe a low-cost system which performs complex image processing operations on-line at video rates. The method uses a combination of unsharp mask subtraction (for low-frequency suppression) and statistical differencing (which adjusts the gain at each point of the image on the basis of its variation from a local mean). The operator interactively adjusts aperture size, contrast gain, background subtraction, and spatial noise reduction. The system is being evaluated for on-line fluoroscopic enhancement, for which phantom measurements and clinical results, including lithotripsy, are presented. When used with a video camera, postprocessing of radiographs was advantageous in a variety of studies, including neonatal chest studies. Real-time speed allows use of the system in the reading room as a ''variable view box.''

1986-12-05

274

Dynamics of bioluminescence by Armillaria gallica, A. mellea and A. tabescens.  

Science.gov (United States)

Although fungal bioluminescence is well documented, the ecological significance is poorly understood. We examined bioluminescence by three sympatric species of Armillaria wood decay fungi, differing in parasitic ability. Luminescence by mycelia of four genets of A. gallica, A. mellea and A. tabescens was examined in response to environmental illumination or mechanical disturbance. Luminescence dynamics were assessed in a time series of measurements every 2 min for 72 h for mycelia growing on malt agar or on Cornus florida root wood. Luminescence by the necrotrophic species A. gallica was enhanced by environmental illumination and mechanical disturbance of mycelia. In contrast luminescence by the more parasitic A. mellea and A. tabescens was quenched by prolonged exposure to environmental illumination and less responsive to mechanical disturbance. With environmental illumination absent, all mycelia representing six genets of each Armillaria species were constitutively luminescent. The temporal dynamics of luminescence by all mycelia were complex with no evidence of the previously reported diurnal periodicity. Differences among Armillaria spp. in bioluminescence expression might reflect differences in ecological context as well. PMID:17883025

Mihail, Jeanne D; Bruhn, Johann N

275

The application of bioluminescence assay with culturing for evaluating quantitative disinfection performance.  

UK PubMed Central (United Kingdom)

Various methods, including bioluminescence assay, were investigated regarding their suitability for quantitatively evaluating the disinfection performance. Although bioluminescence assay itself has been widely reported as a rapid, easy and suitable method for analyzing live microorganisms, the limited sensitivity of its measurement (approximately 10(3)-10(4)cells/assay vial), which is insufficient for disinfection study, requires further study. Among three methods (amplifying by enzymatic method, membrane filtration, and amplification by culturing) examined for increasing the detection sensitivity, amplification by culturing showed the best performance as Escherichia coli was employed as an indicating microorganism. Even with a short culturing time of 4h, the detection limit of E. coli measurement was successfully improved 200-fold, and the analytical results were not dependent upon the state of E. coli growth (stationary state with E. coli stock suspension vs. growth state with E. coli). In addition, the analytical integrity of bioluminescence assay with culturing was further demonstrated in comparison with spread plate method as free chlorine and UV irradiation were employed in the disinfection study.

Cho M; Yoon J

2007-02-01

276

The application of bioluminescence assay with culturing for evaluating quantitative disinfection performance.  

Science.gov (United States)

Various methods, including bioluminescence assay, were investigated regarding their suitability for quantitatively evaluating the disinfection performance. Although bioluminescence assay itself has been widely reported as a rapid, easy and suitable method for analyzing live microorganisms, the limited sensitivity of its measurement (approximately 10(3)-10(4)cells/assay vial), which is insufficient for disinfection study, requires further study. Among three methods (amplifying by enzymatic method, membrane filtration, and amplification by culturing) examined for increasing the detection sensitivity, amplification by culturing showed the best performance as Escherichia coli was employed as an indicating microorganism. Even with a short culturing time of 4h, the detection limit of E. coli measurement was successfully improved 200-fold, and the analytical results were not dependent upon the state of E. coli growth (stationary state with E. coli stock suspension vs. growth state with E. coli). In addition, the analytical integrity of bioluminescence assay with culturing was further demonstrated in comparison with spread plate method as free chlorine and UV irradiation were employed in the disinfection study. PMID:17229450

Cho, Min; Yoon, Jeyong

2007-01-16

277

Colors of firefly bioluminescence. Part I. Optimization model  

Energy Technology Data Exchange (ETDEWEB)

A model is developed for the optimization of signal-to-noise ratio for the detection of bioluminescence by fireflies during twilight. The relative degree of optimization is derived in terms of a dimensionless ratio, a biologically effective adaptation. The numerical values of this adaptation can be used to predict the sequence of adaptations of both visual spectral sensitivities and bioluminescence spectral emissions that result in the range of colors of bioluminescence of fireflies from green through yellow. It is shown that a narrowing of visual spectral sensitivity via a screening pigment pathway in order to discriminate against green ambient light is more efficient than a shift in visual spectral sensitivity via change in the opsin photoprotein. The model predicts that the range of wavelengths for the peak intensities of bioluminescence for North American fireflies should be between 550 and 580 nm and provides the physical basis for the observations that in general dark-active firefly species emit green bioluminescence and twilight-active firefly species emit yellow bioluminescence. 25 references, 4 figures.

Seliger, H.H.; Lall, A.B.; Lloyd, J.E.; Biggley, W.H.

1982-01-01

278

Seasonal variation of deep-sea bioluminescence in the Ionian Sea  

International Nuclear Information System (INIS)

The ICDeep (Image Intensified Charge Coupled Device for Deep sea research) profiler was used to measure the density of deep bioluminescent animals (BL) through the water column in the east, west and mid-Ionian Sea and in the Algerian Basin. A west to east decrease in BL density was found. Generalized additive modelling was used to investigate seasonal variation in the east and west Ionian Sea (NESTOR and NEMO neutrino telescope sites, respectively) from BL measurements in autumn 2008 and spring 2009. A significant seasonal effect was found in the west Ionian Sea (p

2011-01-01

279

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

280

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

Energy Technology Data Exchange (ETDEWEB)

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.

Christensen, A.B.; Walterscheid, R.L.; Ross, M.N. [Aerospace Corp., Los Angeles, CA (United States). Space and Environment Technology Center] [and others

1994-12-31

 
 
 
 
281

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

282

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

Energy Technology Data Exchange (ETDEWEB)

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-[{sup 124}I] iodouracil ({sup 124}I - 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 ({sup 124}I-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, {sup 124}I-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, {sup 124}I-FIAU selectively localized in HSV -tk expressing tumor and the therapeutic efficacy of GCV treatment was evaluated by {sup 124}I-FIAU PET imaging. {sup 124}I-FIAU PET and bioluminescence imaging in HSV-tk suicide gene therapy were effective to evaluate the therapeutic response. {sup 124}I-FIAU may serve as an efficient and selective agent for monitoring of transduced HSV1-tk gene expression in vivo in clinical trials.

Lee, T. S.; Kim, J. H.; Kwon, H. C. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)] (and others)

2007-07-01

283

Development of a biosensor for on-line detection of tributyltin with a recombinant bioluminescent Escherichia coli strain.  

UK PubMed Central (United Kingdom)

A biosensor was developed for the detection of tributyltin (TBT), using a bioluminescent recombinant Escherichia coli:: luxAB strain. Dedicated devices allowed the on-line measurement of bioluminescence, pH and dissolved oxygen values and the feed-back regulation of temperature. Bacterial physiology was monitored by the measurement of the cellular density, respiratory activity and the intracellular level of ATP, glucose and acetate levels. Our results showed that a synthetic glucose medium gave a better TBT detection limit than LB medium (respectively 0.02 micro M and 1.5 micro M TBT). High growth and dilution rates ( D=0.9 h(-1)) allowed maximum light emission from the bacterium. Moreover, simple atmospheric air bubbling was sufficient to provide oxygen for growth and the bioluminescence reaction. Real-time monitoring of bioluminescence after TBT induction occurred with continuous addition of decanal up to 300 micro M, which was not toxic throughout a 7-day experiment. The design of our biosensor and the optimization of the main parameters that influence microbial activity led to the capacity for the detection of TBT.

Thouand G; Horry H; Durand MJ; Picart P; Bendriaa L; Daniel P; DuBow MS

2003-08-01

284

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.)

2010-01-01

285

Color-based features for registering image time series  

Science.gov (United States)

Change detection is a important problem which plays a crucial role in many applications like environmental monitoring and city planning. The goal of change detection is to detects changes in specific features within certain time intervals. In this paper, we develop an automated method for detecting changes in urban areas over a period of time using lines and colors as features. Our proposed algorithm consists of two steps. In the first step, we detect corresponding lines between two images taken over different periods of time and we match them using our search algorithm. To be specific, first we use the Hough transform to detect lines. In the second step, we use colors to detect the changes over static and dyanmic objects. In a test of the method using aerial images over the our university campus area, we obtained reasonably good pose recovery and detection of scene changes.

Duraisamy, Prakash; Belkhouche, Yassine; Jackson, Stephen; Namuduri, Kamesh; Buckles, Bill

2012-05-01

286

The bioluminescent Listeria monocytogenes strain Xen32 is defective in flagella expression and highly attenuated in orally infected BALB/cJ mice.  

UK PubMed Central (United Kingdom)

BACKGROUND: In vivo bioluminescence imaging (BLI) is a powerful method for the analysis of host-pathogen interactions in small animal models. The commercially available bioluminescent Listeria monocytogenes strain Xen32 is commonly used to analyse immune functions in knockout mice and pathomechanisms of listeriosis. FINDINGS: To analyse and image listerial dissemination after oral infection we have generated a murinised Xen32 strain (Xen32-mur) which expresses a previously described mouse-adapted internalin A. This strain was used alongside the Xen32 wild type strain and the bioluminescent L. monocytogenes strains EGDe-lux and murinised EGDe-mur-lux to characterise bacterial dissemination in orally inoculated BALB/cJ mice. After four days of infection, Xen32 and Xen32-mur infected mice displayed consistently higher rates of bioluminescence compared to EGDe-lux and EGDe-mur-lux infected animals. However, surprisingly both Xen32 strains showed attenuated virulence in orally infected BALB/c mice that correlated with lower bacterial burden in internal organs at day 5 post infection, smaller losses in body weights and increased survival compared to EGDe-lux or EGDe-mur-lux inoculated animals. The Xen32 strain was made bioluminescent by integration of a lux-kan transposon cassette into the listerial flaA locus. We show here that this integration results in Xen32 in a flaA frameshift mutation which makes this strain flagella deficient. CONCLUSIONS: The bioluminescent L. monocytogenes strain Xen32 is deficient in flagella expression and highly attenuated in orally infected BALB/c mice. As this listerial strain has been used in many BLI studies of murine listeriosis, it is important that the scientific community is aware of its reduced virulence in vivo.

Bergmann S; Rohde M; Schughart K; Lengeling A

2013-01-01

287

Digital image processing of real-time radiographic images for waste characterization  

Energy Technology Data Exchange (ETDEWEB)

A digital image processing system has been developed for use in real-time radiographic analysis. This system provides tools for quantitative analysis of waste container contents such as volumes of liquids and dimensions of objects. The system processes incoming video signals in real-time and is controlled via a Windows user interface.

Allemeier, R.T.; Tow, D.M.; Miller, G.V. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1995-12-31

288

Digital image processing of real-time radiographic images for waste characterization  

International Nuclear Information System (INIS)

A digital image processing system has been developed for use in real-time radiographic analysis. This system provides tools for quantitative analysis of waste container contents such as volumes of liquids and dimensions of objects. The system processes incoming video signals in real-time and is controlled via a Windows user interface

1995-01-01

289

Time-resolved tomographic images of a relativistic electron beam  

Energy Technology Data Exchange (ETDEWEB)

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 0/sup 0/, 61/sup 0/, and 117/sup 0/. 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.

Koehler, H.A.; Jacoby, B.A.; Nelson, M.

1984-07-01

290

Cellular Neural Network for Real Time Image Processing  

International Nuclear Information System (INIS)

Since their introduction in 1988, Cellular Nonlinear Networks (CNNs) have found a key role as image processing instruments. Thanks to their structure they are able of processing individual pixels in a parallel way providing fast image processing capabilities that has been applied to a wide range of field among which nuclear fusion. In the last years, indeed, visible and infrared video cameras have become more and more important in tokamak fusion experiments for the twofold aim of understanding the physics and monitoring the safety of the operation. Examining the output of these cameras in real-time can provide significant information for plasma control and safety of the machines. The potentiality of CNNs can be exploited to this aim. To demonstrate the feasibility of the approach, CNN image processing has been applied to several tasks both at the Frascati Tokamak Upgrade (FTU) and the Joint European Torus (JET).

2008-03-12

291

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

1984-01-01

292

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)

1979-01-01

293

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

294

Seasonal Changes of Bioluminescence in Photosynthetic and Heterotrophic Dinoflagellates at San Clemente Island.  

Science.gov (United States)

Despite strong interest in short term process effects on dinoflagellates there have been few investigations on the seasonality of marine bioluminescence. Long term aspects of the development of bioluminescence are unknown for most oceans. The present stud...

D. Lapota

2012-01-01

295

Construction of a tumor-specific bioluminescent eukaryotic expression vector and analysis of its expression in vitro and in vivo.  

UK PubMed Central (United Kingdom)

The aims of this study were to construct a tumor-specific bioluminescent eukaryotic vector driven by the hTERT gene promoter and to establish a stable HeLa cell line expressing a modified firefly luciferase gene. PhTERTp-luc and pGL4.17 (luc2/Neo) were digested with SacI and HindIII, respectively, and the recombinant vector phTERTp-luc-neo was generated by ligating the desired fragments. The expression of phTERTp-luc-neo was tested in a non-transformed cell line (MRC-5), and in telomerase-positive (HeLa, MCF-7 and 293T) and -negative (U2OS and SaOS) transformed cell lines using a luciferase assay. Results showed that the recombinant vector had higher luciferase activity in telomerase-positive transformed cell lines. PhTERTp-luc-neo was transfected into a HeLa cell line, selected by G418 and bioluminescence imaging, and a cell clone HeLa-luc that constitutively expressed both neomycin and luciferase was obtained. We also conducted experiments in animals to observe luciferase activity in vivo using stable cell lines that were subcutaneously implanted into BALB/c nude mice and tumor growth was monitored by bioluminescence imaging. The HeLa-luc cell line retained its oncogenicity and tumors were detected on the fifth day following implantation by bioluminescence imaging. This study has formed a basis for the study of the expression and regulation of hTERT and early tumor detection. It also provides a convenient, sensitive and reliable platform for cervical cancer research.

Chen Q; Li F; Zhou F; Wang W; Xu Y; Sun W; Zhou Y

2013-07-01

296

Improvements in sensitivity and response times of photon imaging tubes  

Energy Technology Data Exchange (ETDEWEB)

In order to increase the transmission and speed of response of fibreoptic faceplates in imaging tubes a method is reported which used metallization only of the interfibre glass regions. This offers maximum transmission of the fibres whilst supporting high conductivity, as required for fast response times. An initial metal layer was laser ablated with light directed through the fibre array to provide a self-aligning process. Transmission has been increased threefold compared with earlier metal layer methods, which is of particular value for long wavelength sensitivity where the cathode efficiency is low. By allowing the use of more conductive pathways the more critical values of the response times have been reduced from the nanosecond to the picosecond range for these imaging tubes.

Townsend, P D [Science and Technology, University of Sussex, Brighton, BN1 9QH (United Kingdom); Hallensleben, S [Science and Technology, University of Sussex, Brighton, BN1 9QH (United Kingdom); Phillips, M [Science and Technology, University of Sussex, Brighton, BN1 9QH (United Kingdom); Downey, R J [Science and Technology, University of Sussex, Brighton, BN1 9QH (United Kingdom); Brooks, R J [Photek Ltd, 26 Castleham Rd, St Leonards on Sea, Sussex, TN38 9NS (United Kingdom); Howorth, J [Photek Ltd, 26 Castleham Rd, St Leonards on Sea, Sussex, TN38 9NS (United Kingdom); Milnes, J [Photek Ltd, 26 Castleham Rd, St Leonards on Sea, Sussex, TN38 9NS (United Kingdom)

2006-10-21

297

Imaging cell biology in live animals: ready for prime time.  

UK PubMed Central (United Kingdom)

Time-lapse fluorescence microscopy is one of the main tools used to image subcellular structures in living cells. Yet for decades it has been applied primarily to in vitro model systems. Thanks to the most recent advancements in intravital microscopy, this approach has finally been extended to live rodents. This represents a major breakthrough that will provide unprecedented new opportunities to study mammalian cell biology in vivo and has already provided new insight in the fields of neurobiology, immunology, and cancer biology.

Weigert R; Porat-Shliom N; Amornphimoltham P

2013-06-01

298

Imaging crystallographic phases using time-of-flight neutron diffraction  

International Nuclear Information System (INIS)

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.

2006-11-15

299

Effect of human serum on bioluminescence of natural and recombinant luminescent bacteria.  

Science.gov (United States)

Biphasic modification of bacterial bioluminescence by human serum was revealed: bioluminescence was inhibited at high concentrations of the serum and stimulated at low concentrations. Effects of temperature and duration of exposure on bioluminescence manifested in stimulation of the inhibitory effect at higher temperature and longer exposure. The degree of inhibition of bioluminescence under in the presence of serum depends on species characteristics of the microorganism and nature of the luminescent system. PMID:15665923

Deryabin, D G; Polyakov, E G

2004-09-01

300

Effect of human serum on bioluminescence of natural and recombinant luminescent bacteria.  

UK PubMed Central (United Kingdom)

Biphasic modification of bacterial bioluminescence by human serum was revealed: bioluminescence was inhibited at high concentrations of the serum and stimulated at low concentrations. Effects of temperature and duration of exposure on bioluminescence manifested in stimulation of the inhibitory effect at higher temperature and longer exposure. The degree of inhibition of bioluminescence under in the presence of serum depends on species characteristics of the microorganism and nature of the luminescent system.

Deryabin DG; Polyakov EG

2004-09-01

 
 
 
 
301

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

302

Real-time in vivo imaging of p16Ink4a gene expression: a new approach to study senescence stress signaling in living animals  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Oncogenic proliferative signals are coupled to a variety of growth inhibitory processes. In cultured primary human fibroblasts, for example, ectopic expression of oncogenic Ras or its downstream mediator initiates cellular senescence, the state of irreversible cell cycle arrest, through up-regulation of cyclin-dependent kinase (CDK) inhibitors, such as p16INK4a. To date, much of our current knowledge of how human p16INK4a gene expression is induced by oncogenic stimuli derives from studies undertaken in cultured primary cells. However, since human p16INK4a gene expression is also induced by tissue culture-imposed stress, it remains unclear whether the induction of human p16INK4a gene expression in tissue-cultured cells truly reflects an anti-cancer process or is an artifact of tissue culture-imposed stress. To eliminate any potential problems arising from tissue culture imposed stress, we have recently developed a bioluminescence imaging (BLI) system for non-invasive and real-time analysis of human p16INK4a gene expression in the context of a living animal. Here, we discuss the molecular mechanisms that direct p16INK4a gene expression in vivo and its potential for tumor suppression.

Ohtani Naoko; Yamakoshi Kimi; Takahashi Akiko; Hara Eiji

2010-01-01

303

Real-time Image Generation for Compressive Light Field Displays  

Science.gov (United States)

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.

Wetzstein, G.; Lanman, D.; Hirsch, M.; Raskar, R.

2013-02-01

304

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.

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

2013-01-01

305

Real time blood testing using quantitative phase imaging.  

UK PubMed Central (United Kingdom)

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.

Pham HV; Bhaduri B; Tangella K; Best-Popescu C; Popescu G

2013-01-01

306

Real-time neutron monitoring method using an imaging plate  

International Nuclear Information System (INIS)

A novel system for real-time radiation monitoring in reactor or accelerator facilities has been studied using an imaging plate. The authors made a feasibility study on a new neutron detection system using both photostimulated luminescence (PSL) and prompt luminescence (PL) generated in a neutron imaging plate (NIP) when the NIP is irradiated by neutrons. A readout system consisting of a semiconductor laser and a photomultiplier tube was fabricated for the purpose. It was confirmed that the system can measure both PSL and PL, where Am-Li was used as a neutron source. It may be possible to establish a new wide-range neutron monitoring system using the developed system as a PL mode normally, and as a PSL mode in case of intense neutron dose that cannot be measured in a PL mode because of saturation of the detection system. (author)

1999-01-01

307

A portable, real-time, holographic system for imaging flaws  

International Nuclear Information System (INIS)

In this paper the authors describe a portable system that can be used in a field situation. Image reconstruction is accomplished mathematically in near real-time, and the image displayed in a variety of formats. The system utilizes a special purpose microcomputer designed around the 16-bit Intel 8086 and 8087 microprocessor chips. The system fits into three suitcase containers that can be shipped as excess baggage on most air-lines. The system has been tested on pressure vessel and piping samples containing machined and natural flaws, and has also been used in the field to inspect a weld in the steam generator shell of a nuclear power plant. The theory, implementation, and experimental results are presented.

1983-12-02

308

Simultaneous evaluation of chemiluminescence and bioluminescence in a phagocytic system.  

UK PubMed Central (United Kingdom)

The spectra of luminol-dependent chemiluminescence of leukocytes, forming as a result of their oxygen-dependent bactericidal systems activation, and bacterial bioluminescence of Escherichia coli recombinant strain with cloned lux operon, used as the object of phagocytosis, are not identical. Mutual overlapping of these spectra reaches 87%, including overlapping of the photoemission maximums. However these spectra can be evaluated separately in the short-wave "arm" of the chemiluminescence spectrum (<420 nm) and the long-wave "arm" of the bioluminescence spectrum (>560). The kinetics of luminol-dependent chemiluminescence of phagocytes and of bacterial bioluminescence in their mixtures is characterized by mutually dependent phase-wise changes in the intensity of the analyzed parameters.

Deryabin DG; Karimov IF

2009-03-01

309

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 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 < 0.05) of 18F-FEAU than fluorine-18-labeled 9-(4-fluoro-3-hydroxymethylbutyl)guanine. This improved triple fusion reporter vector will enable high sensitivity detection of lower numbers of cells from living animals using the combined bioluminescence, fluorescence, and microPET imaging techniques. PMID:17409415

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

2007-04-01

310

Simultaneous evaluation of chemiluminescence and bioluminescence in a phagocytic system.  

Science.gov (United States)

The spectra of luminol-dependent chemiluminescence of leukocytes, forming as a result of their oxygen-dependent bactericidal systems activation, and bacterial bioluminescence of Escherichia coli recombinant strain with cloned lux operon, used as the object of phagocytosis, are not identical. Mutual overlapping of these spectra reaches 87%, including overlapping of the photoemission maximums. However these spectra can be evaluated separately in the short-wave "arm" of the chemiluminescence spectrum (560). The kinetics of luminol-dependent chemiluminescence of phagocytes and of bacterial bioluminescence in their mixtures is characterized by mutually dependent phase-wise changes in the intensity of the analyzed parameters. PMID:19529859

Deryabin, D G; Karimov, I F

2009-03-01

311

Real-time imaging for dose evaluation during antiproton irradiation  

DEFF Research Database (Denmark)

Online monitoring of the stopping distribution of particle beams used for radiotherapy provides the possibility of detecting possible errors in dose deposition early during a given treatment session, and may therefore help to improve the quality of the therapy. Antiproton annihilation events produce several long-range secondary particles which can be detected in real time by standard high energy particle physics detector systems. In this note, Monte Carlo calculations are performed in order to study the feasibility of real-time imaging by detecting charged pions produced during antiproton irradiation of typical biological targets. A simple treatment plan in a water phantom is simulated and the results show that by detecting pi+/- the position and the size of the planned target volume can be located with precision in the order of 1 mm.

Kantemiris, I; Angelopoulos, A

2010-01-01

312

Advanced Imaging by Space-Time Deconvolution in Array GPR  

Science.gov (United States)

Digital beamforming in array-based UWB radar delivers a high-resolution 3-D image of subsurface in GPR landmine detection while simultaneous data acquisition by elements of the array significantly increases the scanning speed. Such a GPR system with a single transmit antenna and a linear receive array has been developed in the Delft University of Technology. For online processing we propose an advanced imaging algorithm based on migration by regularized, parametric space-time deconvolution. The algorithm deconvolves a 3-D space-time array point spread function out of the data volume by means of FFT and inverse Wiener filter that is being controlled automatically with numerical criteria for stability and accuracy. The prior knowledge of GPR impulse response and ground impulse response is used to form a separate point spread function for each receiving antenna. The developed technique has been verified on experimental data for typical anti-personnel mines and compared with a classical migration by diffraction stacking.

Savelyev, T. G.; van Tol, N. T.; Yarovoy, A. G.; Ligthart, L. P.

313

Reducing imaging waiting times: enhanced roles and service-redesign.  

UK PubMed Central (United Kingdom)

PURPOSE: The aim of this paper is to explain how University Hospitals of Leicester's Nuclear Medicine service managers needed to reduce waiting times to comply with internal clinical requirements and with external local primary care trust (PCT) and national Department of Health targets. DESIGN/METHODOLOGY/APPROACH: The team undertook a comprehensive service review to identify problem areas and potential improvements, including: process mapping; data gathering (activity and demand, equipment and staff availability/utilisation); external practice reviews, searching evidence bases; and financial implications. This case study describes how an inter-disciplinary team redesigned the service and used new working methods to reduce waiting times. Their aim was to discuss a service's practical elements and show how innovation leading to sustainable change can be implemented effectively. FINDINGS: The review highlighted service delivery bottlenecks for myocardial perfusion imaging, which were linked to medical staff shortages, staff use and equipment between hospital sites, and a silo approach to referrals rather than a coordinated organisation-wide approach. PRACTICAL IMPLICATIONS: Introducing enhanced roles allowed nurses, radiographers and technologists to undertake work previously performed by medical staff thus removing a key service bottleneck. Modifications to service delivery and a cultural change in nuclear medicine resulted in a service that was more efficient, flexible and able to cope with increased demand. ORIGINALITY/VALUE: These changes meant that minimum waiting-time targets were achieved, in particular waiting for myocardial perfusion imaging (reduced from 42 weeks in 2005 to two weeks by 2009). Changes allowed service managers to maintain short waiting times in the current, challenging healthcare climate.

Greaves C; Gilmore J; Bernhardt L; Ross L

2013-01-01

314

Quorum Sensing Signal Synthesis May Represent a Selective Advantage Independent of Its Role in Regulation of Bioluminescence in Vibrio fischeri.  

UK PubMed Central (United Kingdom)

The evolution of biological signalling systems and apparently altruistic or cooperative traits in diverse organisms has required selection against the subversive tendencies of self-interested biological entities. The bacterial signalling and response system known as quorum sensing or Acylated Homoserine Lactone (AHL) mediated gene expression is thought to have evolved through kin selection. In this in vitro study on the model quorum sensing bioluminescent marine symbiont Vibrio fischeri, competition and long-term sub culturing experiments suggest that selection for AHL synthesis (encoded by the AHL synthase gene luxI) is independent of the quorum sensing regulated phenotype (bioluminescence encoded by luxCDABE). Whilst results support the hypothesis that signal response (AHL binding and transcriptional activation encoded by the luxR gene) is maintained through indirect fitness benefits (kin selection), signal synthesis is maintained in the V. fischeri genome over evolutionary time through direct fitness benefits at the individual level from an unknown function.

Chong G; Kimyon O; Manefield M

2013-01-01

315

Real-time intravital imaging of cancer models.  

Science.gov (United States)

High-resolution intravital imaging (IVM) has proven to be a powerful technique to visualise dynamic processes that are important for tumour progression, such as the interplay between tumour cells and cellular components of the tumour microenvironment. The development of IVM tools, including imaging windows and photo-marking of individual cells, has led to the visualisation of dynamic processes and tracking of individual cells over a time span of days. In order to visualise these dynamic processes, several strategies have been described to develop fluorescent IVM tumour models. Genetic tools to engineer fluorescent tumour cell lines have advanced the applications of cell line-based tumour models to study, for example, changes in behaviour or transcriptional and differentiation state of individual cells in a tumour. In order to study tumour progression, fluorescent genetic mouse models have been engineered that better recapitulate human tumours. These technically challenging tumour models are key in visualising dynamic processes during cancer progression and in the translational aspects of IVM experiments. PMID:22126727

Zomer, A; Beerling, E; Vlug, E J; van Rheenen, J

2011-12-01

316

Digital image processing for real-time neutron radiography and its applications  

International Nuclear Information System (INIS)

[en] The present paper describes several digital image processing approaches for the real-time neutron radiography (neutron television-NTV), such as image integration, adaptive smoothing and image enhancement, which have beneficial effects on image improvements, and also describes how to use these techniques for applications. Details invisible in direct images of NTV are able to be revealed by digital image processing, such as reversed image, gray level correction, gray scale transformation, contoured image, subtraction technique, pseudo color display and so on. For real-time application a contouring operation and an averaging approach can also be utilized effectively. (author)

1988-06-18

317

Multimodality imaging of TGFbeta signaling in breast cancer metastases.  

Science.gov (United States)

The skeleton is a preferred site for breast cancer metastasis. We have developed a multimodality imaging approach to monitor the transforming growth factor beta (TGFbeta) signaling pathway in bone metastases, sequentially over time in the same animal. As model systems, two MDA-MB-231 breast cancer cells lines with different metastatic tropisms, SCP2 and SCP3, were transduced with constitutive and TGFbeta-inducible reporter genes and were tested in vitro and in living animals. The sites and expansion of metastases were visualized by bioluminescence imaging using a constitutive firefly luciferase reporter, while TGFbeta signaling in metastases was monitored by microPET imaging of HSV1-TK/GFP expression with [(18)F]FEAU and by a more sensitive and cost-effective bioluminescence reporter, based on nonsecreted Gaussia luciferase. Concurrent and sequential imaging of metastases in the same animals provided insight into the location and progression of metastases, and the timing and course of TGFbeta signaling. The anticipated and newly observed differences in the imaging of tumors from two related cell lines have demonstrated that TGFbeta signal transduction pathway activity can be noninvasively imaged with high sensitivity and reproducibility, thereby providing the opportunity for an assessment of novel treatments that target TGFbeta signaling. PMID:19325038

Serganova, Inna; Moroz, Ekaterina; Vider, Jelena; Gogiberidze, George; Moroz, Maxim; Pillarsetty, Nagavarakishore; Doubrovin, Michael; Minn, Andy; Thaler, Howard T; Massague, Joan; Gelovani, Juri; Blasberg, Ronald

2009-03-26

318

Multimodality imaging of TGFbeta signaling in breast cancer metastases.  

UK PubMed Central (United Kingdom)

The skeleton is a preferred site for breast cancer metastasis. We have developed a multimodality imaging approach to monitor the transforming growth factor beta (TGFbeta) signaling pathway in bone metastases, sequentially over time in the same animal. As model systems, two MDA-MB-231 breast cancer cells lines with different metastatic tropisms, SCP2 and SCP3, were transduced with constitutive and TGFbeta-inducible reporter genes and were tested in vitro and in living animals. The sites and expansion of metastases were visualized by bioluminescence imaging using a constitutive firefly luciferase reporter, while TGFbeta signaling in metastases was monitored by microPET imaging of HSV1-TK/GFP expression with [(18)F]FEAU and by a more sensitive and cost-effective bioluminescence reporter, based on nonsecreted Gaussia luciferase. Concurrent and sequential imaging of metastases in the same animals provided insight into the location and progression of metastases, and the timing and course of TGFbeta signaling. The anticipated and newly observed differences in the imaging of tumors from two related cell lines have demonstrated that TGFbeta signal transduction pathway activity can be noninvasively imaged with high sensitivity and reproducibility, thereby providing the opportunity for an assessment of novel treatments that target TGFbeta signaling.

Serganova I; Moroz E; Vider J; Gogiberidze G; Moroz M; Pillarsetty N; Doubrovin M; Minn A; Thaler HT; Massague J; Gelovani J; Blasberg R

2009-08-01

319

Evaluation of scintillator afterglow for use in a combined optical and PET imaging tomograph  

International Nuclear Information System (INIS)

[en] The design of a dual modality imaging system for small animal optical and positron emission tomography imaging (OPET) is underway. Its detector must be capable of imaging high energy ?-rays from PET while also resolving optical wavelength photons from bioluminescence. GSO, high purity GSO, BGO, LSO, LYSO, and LaBr scintillators were investigated for their use in the OPET detector. Of specific interest were scintillators with low afterglow, since afterglow photons in the decay of the larger ?-ray events are indistinguishable from the photons generated by bioluminescence. Samples from these crystals were coupled to a photomultiplier tube (PMT) and produced scintillation light from ?-ray events originating from a positron source. The PMT output was directed to a special signal processing circuit that allowed measurement of single photons at different times in the decay of the scintillation. GSO and BGO exhibited optimal performance for use in the OPET system due to their low afterglow. LSO, LYSO, and LaBr were determined unsuitable for use with the current OPET design due to their significant afterglow components. The effect of the afterglow of GSO on the detection of the bioluminescence signal-to-noise ratio (SNR) was evaluated for the OPET system

2006-12-20

320

Evaluation of scintillator afterglow for use in a combined optical and PET imaging tomograph  

Energy Technology Data Exchange (ETDEWEB)

The design of a dual modality imaging system for small animal optical and positron emission tomography imaging (OPET) is underway. Its detector must be capable of imaging high energy {gamma}-rays from PET while also resolving optical wavelength photons from bioluminescence. GSO, high purity GSO, BGO, LSO, LYSO, and LaBr scintillators were investigated for their use in the OPET detector. Of specific interest were scintillators with low afterglow, since afterglow photons in the decay of the larger {gamma}-ray events are indistinguishable from the photons generated by bioluminescence. Samples from these crystals were coupled to a photomultiplier tube (PMT) and produced scintillation light from {gamma}-ray events originating from a positron source. The PMT output was directed to a special signal processing circuit that allowed measurement of single photons at different times in the decay of the scintillation. GSO and BGO exhibited optimal performance for use in the OPET system due to their low afterglow. LSO, LYSO, and LaBr were determined unsuitable for use with the current OPET design due to their significant afterglow components. The effect of the afterglow of GSO on the detection of the bioluminescence signal-to-noise ratio (SNR) was evaluated for the OPET system.

Douraghy, Ali [Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA School of Medicine, A136, 700 Westwood Plaza, Los Angeles, CA 90095-1770 (United States)]. E-mail: adouraghy@mednet.ucla.edu; Prout, David L. [Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA School of Medicine, A136, 700 Westwood Plaza, Los Angeles, CA 90095-1770 (United States); Silverman, Robert W. [Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA School of Medicine, A136, 700 Westwood Plaza, Los Angeles, CA 90095-1770 (United States); Chatziioannou, Arion F. [Department of Molecular and Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA School of Medicine, A136, 700 Westwood Plaza, Los Angeles, CA 90095-1770 (United States)

2006-12-20

 
 
 
 
321

Adaptive time gain compensation system for ultrasound imaging  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an ultrasound imaging system adapted to receive temporally related image frames, each frame comprised of signals representative of reflected ultrasonic waves derived from scanning of an image plane in a patient. The system includes a gain controlled amplifier and image formation means adapted to produce at least one image based upon the image frames and responsive to signals from the gain controlled amplifier. A gain control system discriminates between signals from non-attenuating fluid filled regions and signals from attenuating reflective tissue regions comprising.

Riley, J.K.

1987-05-05

322

High-resolution imaging with a real-time synthetic aperture ultrasound system: a phantom study  

Science.gov (United States)

It is difficult for ultrasound to image small targets such as breast microcalcifications. Synthetic aperture ultrasound imaging has recently developed as a promising tool to improve the capabilities of medical ultrasound. We use two different tissueequivalent phantoms to study the imaging capabilities of a real-time synthetic aperture ultrasound system for imaging small targets. The InnerVision ultrasound system DAS009 is an investigational system for real-time synthetic aperture ultrasound imaging. We use the system to image the two phantoms, and compare the images with those obtained from clinical scanners Acuson Sequoia 512 and Siemens S2000. Our results show that synthetic aperture ultrasound imaging produces images with higher resolution and less image artifacts than Acuson Sequoia 512 and Siemens S2000. In addition, we study the effects of sound speed on synthetic aperture ultrasound imaging and demonstrate that an accurate sound speed is very important for imaging small targets.

Huang, Lianjie; Labyed, Yassin; Simonetti, Francesco; Williamson, Michael; Rosenberg, Robert; Heintz, Philip; Sandoval, Daniel

2011-03-01

323

Evaluation of full time and half time acquired cardiac perfusion images and its correlation with coronary angiography  

International Nuclear Information System (INIS)

[en] Full text: The myocardial perfusion study takes a longer time to complete. A reduction in acquisition time would mean reduced patient motion related artifacts, improvement in camera efficiency and reduction in cost. Iterative reconstruction algorithms produce more accurate images with fewer artifacts. Materials and Methods: Seventy three patients undergoing myocardial perfusion imaging were selected for additional half time acquisition. Patients with suspected or known coronary artery disease who have undergone coronary angiography recently were preferably included. Images were analysed in 4 groups - full time FBP, half time FBP, half time OSEM and half time OSEM. Three independent observers blinded to the clinical data and the acquisition protocol analysed images for change in image quality between these groups. Semiquantitative parameters of summed stress score, summed rest score, summed difference score and left ventricular ejection fraction were also compared using appropriate statistical methods. Results: No difference was noted in SSS, SRS, SDS and LVEF calculated for full time and half time. However, significant difference was found between SSS, SRS and SDS calculated for FBP and OSEM processed half time studies and no significant difference for LVEF calculated for these two groups. Significant change in image quality was noted by 2 observers only in 1.4% and 2.7% of cases. A true positivity rate of 88% was seen in comparison with coronary angiography. Conclusion: Gated myocardial perfusion SPECT images acquired in half the routine scan time provides equal diagnostic information compared to a conventional full time study, regardless of the processing protocol

2010-01-01

324

The development and application of a short range, real-time active imaging system  

Energy Technology Data Exchange (ETDEWEB)

A laser active-imaging system capable of producing real-time, standard (RS-170) TV images was developed. The system consists of a modified flying-spot infrared imager that scans the instantaneous-field-of-view of a single detector in synchrony with the output beam of a continuous-wave laser. The imager has been modified for application to the problems of gas-plume imaging and underwater imaging. 14 refs., 5 figs.

Kulp, T.J.; Kennedy, R.; Garvis, D.; McRae, T.G.

1988-11-01

325

Comparison of 3D imaging and 2D imaging for performance time of laparoscopic cholecystectomy.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The aim of this study is to evaluate the effect of the Viking 3-dimensional (3D) system on performance time of laparoscopic cholecystectomy. METHODS: Twenty-two patients were included in the study. The groups were standardized using a multiparameters filter (MPF) depending on preoperative ultrasonography and perioperative exploration findings. The 11 patients operated with the Viking 3D system (group A) were compared with 11 patients operated with the Olympus 2D/HD system (group B). RESULTS: The mean performance time was 20.63 ± 5.66 and 30.0 ± 6.03 minutes in the group A (3D) and group B (2D), respectively (P<0.01). CONCLUSIONS: The 3D imaging systems may cause a significant reduction in the performance time of laparoscopic cholecystectomy.

Bilgen K; Ustün M; Karakahya M; I?ik S; Sengül S; Cetinkünar S; Küçükpinar TH

2013-04-01

326

Bioluminescent organisms and bioluminescence measurements in the North Atlantic Ocean near latitude 59.5°N, longitude 21°W  

Science.gov (United States)

We investigated mixed-layer bioluminescence from early April to late September (in April 1989, May 1991, July 1983 and 1990, August 1991, September 1988 and 1989) at stations near the Marine-Light - Mixed Layers (MLML) bio-optical moorings site. Volume-specific bioluminescence potential (BPOT, photons per unit volume) from epipelagic organisms was estimated directly with a pump-through bioluminescence photometer (BP) in 1983, 1988, and 1991. For all cruises, BPOT was also estimated by summing for a volume of seawater, the measurements of each species' total stimulable bioluminescence multiplied by each species' numerical abundance in the volume. The abundance data were taken from bottle casts, net tows, and BP effluent nets. After the onset of the spring bloom, from May through September, mixed layer BPOT was fairly constant, ˜1-4×1014 photons m-3. On one early April cruise (1989) before the spring bloom, BPOT was two orders of magnitude lower. Heterotrophic dinoflagellates in the genus Protoperidinium generally produced most (90% or more) of the mixed layer BPOT in the spring, summer, and fall. On one cruise in September (1988), the autotrophic dinoflagellate Ceratium fusus produced the bulk of the mixed layer BPOT (more than about 4×1014 photons m-3). Other autotrophic dinoflagellates in the genus Gonyaulax and mesozooplankton produced a minor part of BPOT at most stations. The relative contribution of all autotrophic dinoflagellates to BPOT increased from a few percent during the May-June-July period to ˜10% during the August-September period. In situ mechanically stimulable bioluminescence was reduced when underwater scalar irradiance (wavelengths 400-700 nm) was greater than 0.1 ?mol photons m-2 s-1.

Swift, Elijah; Sullivan, James M.; Batchelder, Harold P.; van Keuren, Jeffrey; Vaillancourt, Robert D.; Bidigare, Robert R.

1995-04-01

327

High time-resolution sprite imaging: observations and implications  

Science.gov (United States)

Sprites are large scale manifestations of electrical streamers triggered in the upper atmosphere by lightning in an underlying thunderstorm. Imaging of sprites at 10 000 frames per second has provided new insights into their spatial and temporal development. In this paper we discuss the experimental protocols that have been developed for performing high-speed observations of sprites and some new observations that have been obtained of relevance to laboratory experiments. Downward tendrils and upward branches, so characteristic in video recordings, are shown to be formed by very fast streamer heads with velocities up to half the speed of light. The streamer heads are spatially small, ~100 m or less, but very bright with emission rates up to ~1024 photons s-1. The sprite onset begins with a downward streamer. Then, in some sprites, at a little later time and from a lower altitude upward moving streamer heads may also appear. If there are no upward streamers the sprite would be classified as a 'C-sprite'; with both downward and upward streamers it would be a 'carrot sprite'. The optical emissions are primarily from the neutral molecular nitrogen first positive bands emitting in the near-infrared, but there are also blue emissions assumed to be from second positive bands of molecular nitrogen and from first negative bands of nitrogen ions. The streamer heads are observed at times to split into several streamer heads. This process appears to be more frequent in the core of larger sprites.

Stenbaek-Nielsen, H. C.; McHarg, M. G.

2008-12-01

328

High Dynamic Range Image Based on Multiple Exposure Time Synthetization  

Directory of Open Access Journals (Sweden)

Full Text Available High dynamic range of illumination may cause serious distortions and otherproblems in viewing and further processing of digital images. In this paper a new tonereproduction preprocessing algorithm is introduced which may help in developing hardly ornon-viewable features and content of the images. The method is based on the synthetizationof multiple exposure images from which the dense part, i.e. regions having the maximumlevel of detail are included in the output image. The resulted high quality HDR image makeseasier the information extraction and effectively supports the further processing of theimage.

Annamária R. Várkonyi-Kóczy; András Rövid; Szilveszter Balogh; Takeshi Hashimoto; Yoshifumi Shimodaira

2007-01-01

329

Time-resolved computed tomography of the liver: retrospective, multi-phase image reconstruction derived from volumetric perfusion imaging.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To assess feasibility and image quality (IQ) of a new post-processing algorithm for retrospective extraction of an optimised multi-phase CT (time-resolved CT) of the liver from volumetric perfusion imaging. METHODS: Sixteen patients underwent clinically indicated perfusion CT using 4D spiral mode of dual-source 128-slice CT. Three image sets were reconstructed: motion-corrected and noise-reduced (MCNR) images derived from 4D raw data; maximum and average intensity projections (time MIP/AVG) of the arterial/portal/portal-venous phases and all phases (total MIP/ AVG) derived from retrospective fusion of dedicated MCNR split series. Two readers assessed the IQ, detection rate and evaluation time; one reader assessed image noise and lesion-to-liver contrast. RESULTS: Time-resolved CT was feasible in all patients. Each post-processing step yielded a significant reduction of image noise and evaluation time, maintaining lesion-to-liver contrast. Time MIPs/AVGs showed the highest overall IQ without relevant motion artefacts and best depiction of arterial and portal/portal-venous phases respectively. Time MIPs demonstrated a significantly higher detection rate for arterialised liver lesions than total MIPs/AVGs and the raw data series. CONCLUSION: Time-resolved CT allows data from volumetric perfusion imaging to be condensed into an optimised multi-phase liver CT, yielding a superior IQ and higher detection rate for arterialised liver lesions than the raw data series. KEY POINTS: • Four-dimensional computed tomography is limited by motion artefacts and poor image quality. • Time-resolved-CT facilitates 4D-CT data visualisation, segmentation and analysis by condensing raw data. • Time-resolved CT demonstrates better image quality than raw data images. • Time-resolved CT improves detection of arterialised liver lesions in cirrhotic patients.

Fischer MA; Leidner B; Kartalis N; Svensson A; Aspelin P; Albiin N; Brismar TB

2013-08-01

330

Visible light induced ocular delayed bioluminescence as a possible origin of negative afterimage  

CERN Multimedia

The delayed luminescence of biological tissues is an ultraweak reemission of absorbed photons after exposure to external monochromatic or white light illumination. Recently, Wang, B\\'okkon, Dai and Antal (Brain Res. 2011) presented the first experimental proof of the existence of spontaneous ultraweak biophoton emission and visible light induced delayed ultraweak photon emission from in vitro freshly isolated rat's whole eye, lens, vitreous humor and retina. Here, we suggest that the photobiophysical source of negative afterimage can also occur within the eye by delayed bioluminescent photons. In other words, when we stare at a colored (or white) image for few seconds, external photons can induce excited electronic states within different parts of the eye that is followed by a delayed reemission of absorbed photons for several seconds. Finally, these reemitted photons can be absorbed by nonbleached photoreceptors that produce a negative afterimage. Although this suggests the photobiophysical source of negativ...

Bokkon, I; Wang, C; Dai, J; Salari, V; Grass, F; Antal, I

2011-01-01

331

Effect of alternative photostimulable phosphor plates erasing times on subjective digital image quality  

Science.gov (United States)

Objective To evaluate the influence of alternative erasing times of DenOptix® (Dentsply/Gendex, Chicargo, IL) digital plates on subjective image quality and the probability of double exposure image not occurring. Methods Human teeth were X-rayed with phosphor plates using ten different erasing times. Two observers evaluated the images for subjective image quality (sharpness, brightness, contrast, enamel definition, dentin definition and dentin-enamel junction definition) and for the presence or absence of double exposure image. Spearman's correlation analysis and ANOVA was performed to verify the existence of a linear association between the subjective image quality parameters and the alternative erasing times. A contingency table was constructed to evaluate the agreement among the observers, and a binominal logistic regression was performed to verify the correlation between the erasing time and the probability of double exposure image not occurring. Results All 6 parameters of image quality were rated high by the examiners for the erasing times between 25 s and 130 s. The same erasing time range, from 25 to 130 s, was considered a safe erasing time interval, with no probability of a double exposure image occurring. Conclusions The alternative erasing times from 25 s to 130 s showed high image quality and no probability of double image occurrence. Thus, it is possible to reduce the operating time of the DenOptix® digital system without jeopardizing the diagnostic task.

Melo, DP; dos Anjos Pontual, A; de Almeida, SM; Campos, P S F; Alves, MC; Tosoni, GM

2010-01-01

332

Monitoring Therapeutic Treatments against Burkholderia Infections Using Imaging Techniques  

Directory of Open Access Journals (Sweden)

Full Text Available Burkholderia mallei, the etiologic agent of glanders, are Category B select agents with biothreat potential, and yet effective therapeutic treatments are lacking. In this study, we showed that CpG administration increased survival, demonstrating protection in the murine glanders model. Bacterial recovery from infected lungs, liver and spleen was significantly reduced in CpG-treated animals as compared with non-treated mice. Reciprocally, lungs of CpG-treated infected animals were infiltrated with higher levels of neutrophils and inflammatory monocytes, as compared to control animals. Employing the B. mallei bioluminescent strain CSM001 and the Neutrophil-Specific Fluorescent Imaging Agent, bacterial dissemination and neutrophil trafficking were monitored in real-time using multimodal in vivo whole body imaging techniques. CpG-treatment increased recruitment of neutrophils to the lungs and reduced bioluminescent bacteria, correlating with decreased bacterial burden and increased protection against acute murine glanders. Our results indicate that protection of CpG-treated animals was associated with recruitment of neutrophils prior to infection and demonstrated, for the first time, simultaneous real time in vivo imaging of neutrophils and bacteria. This study provides experimental evidence supporting the importance of incorporating optimized in vivo imaging methods to monitor disease progression and to evaluate the efficacy of therapeutic treatment during bacterial infections.

Tiffany M. Mott; R. Katie Johnston; Sudhamathi Vijayakumar; D. Mark Estes; Massoud Motamedi; Elena Sbrana; Janice J. Endsley; Alfredo G. Torres

2013-01-01

333

Real Time Deconvolution of In-Vivo Ultrasound Images  

DEFF Research Database (Denmark)

The axial resolution in medical ultrasound is directly linked to the emitted ultrasound frequency, which, due to tissue attenuation, is selected based on the depth of scanning. The resolution is etermined by the transducers impulse response, which limits the attainable resolution to be between one and two wavelengths. This can be improved by deconvolution, which increase the bandwidth and equalizes the phase to increase resolution under the constraint of the electronic noise in the received signal. A fixed interval Kalman filter based deconvolution routine written in C is employed. It uses a state based model for the ultrasound pulse and can include a depth varying pulse and spatially varying signal-to-noise ration. An autoregressive moving average (ARMA) model of orders 8 and 9 is used for the pulse, and the ARMA parameters are determined as a function of depth using a minimum variance algorithm using averaging over several RF lines. In vivo data from a 3 MHz mechanically rotating probe is used and the received signal is sampled at 20 MHz and 12 bits. In-vivo data acquired from a 16th week old fetus is used along with a scan from the liver and right kidney of a 27 years old male. The axial resolution has been determined from the in-vivo liver image using the auto-covariance function. From the envelope of the estimated pulse the axial resolution at Full-Width-Half-Max is 0.581 mm corresponding to 1.13 l at 3 MHz. The algorithm increases the resolution to 0.116 mm or 0.227 l corresponding to a factor of 5.1. The basic pulse can be estimated in roughly 0.176 seconds on a single CPU core on an Intel i5 CPU running at 1.8 GHz. An in-vivo image consisting of 100 lines of 1600 samples can be processed in roughly 0.1 seconds making it possible to perform real-time deconvolution on ultrasound data by using dual or quad core CPUs for frame-rates of 20-40 Hz.

Jensen, JØrgen Arendt

2013-01-01

334

A real-time S-parameter imaging system  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 diagnozing defect patterns that could help interpret function. S-parameter images can be obtained by electromagnetically rasterin...

Naik, PS; Cheung, CK; Beling, CD; Fung, S

335

REAL TIME TRAFFIC LIGHT CONTROL USING IMAGE PROCESSING  

Directory of Open Access Journals (Sweden)

Full Text Available As the problem of urban traffic congestion spreads, there is a pressing need for the introduction of advanced technology and equipment to improve the state-of-the-art of traffic control. Traffic problems nowadays are increasing because of the growing number of vehicles and the limited resources provided by current nfrastructures. The simplest way for controlling a traffic light uses timer for each phase. Another way is to use electronic sensors in order to detect vehicles, and produce signal that cycles. We propose a system for controlling the traffic light by image processing. The system will detect vehicles through images instead of using lectronic sensors embedded in the pavement. A camera will be installed alongside the traffic light. It will capture image sequences. The image sequence will then be analyzed using digital image processing for vehicle detection, and according to traffic conditions on the road traffic light can be controlled..

PALLAVI CHOUDEKAR; SAYANTI BANERJEE,; M.K.MUJU

2011-01-01

336

Relationship between stability and bioluminescence color of firefly luciferase.  

UK PubMed Central (United Kingdom)

Firefly luciferase catalyzes the oxidation of luciferin in the presence of ATP, Mg(2+) and molecular oxygen. The bioluminescence color of firefly luciferases is identified by the luciferase structure and assay conditions. Amongst different types of beetles, luciferase from Phrixotrix railroad worm (PhRE) with a unique additional residue (Arg353) naturally emits red bioluminescence color. By insertion of Arg356 in luciferase of Lampyris turkestanicus, corresponding to Arg353 in Phrixotrix hirtus, the color of the emitted light was changed to red. To understand the effect of this position on the bioluminescence color shift, four residues with similar sizes but different charges (Arg, Lys, Glu, and Gln) were inserted into Photinus pyralis luciferase. Comparison of mutants with native luciferase shows that mutation brought an increase in the content of secondary structure and globular compactness of (P. pylalis) luciferase. Comparative study of chemical denaturation of native and mutant luciferases by activity measurement, intrinsic and extrinsic fluorescence, circular dichroism, and DSC techniques revealed that insertion of positively charged residues (Arg, Lys) in the flexible loop (352-358) plays a significant role on the stability of (P. pyralis) luciferase and changes the light color to red.

Maghami P; Ranjbar B; Hosseinkhani S; Ghasemi A; Moradi A; Gill P

2010-03-01

337

Serotonin and nitric oxide interaction in the control of bioluminescence in northern krill, Meganyctiphanes norvegica (M. Sars)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The role of nitric oxide ( NO) in the control of bioluminescence ( light production) in the crustacean Meganyctiphanes norvegica ( krill) was investigated using pharmacological and immunohistochemical methods. All nitrergic drugs tested failed to induce bioluminescence per se but modulated light pro...

Kronstrom, Jenny; Dupont, Samuel; Mallefet, Jérôme; Thorndyke, Michael; Holmgren, Susanne

338

Resistivity structures imaging using time-domain electromagnetic data; TDEM ho ni yoru chika hiteiko kozo no imaging  

Energy Technology Data Exchange (ETDEWEB)

The kernel function for transient vertical magnetic dipole was defined for semi-infinite uniform medium, and the 1-D imaging algorithm by TDEM (time-domain electromagnetic) method was developed for underground resistivity structure. Electromagnetic migration method directly images sectional resistivity profiles from the data observed by frequency-domain MT method, and determines underground resistivity profiles by integral equation of MT field using the concept of return travel time in reflection seismic exploration. The method reported in this paper is also one of the EM migration methods. The imaging algorithm of 2-D resistivity structure was developed by correcting 1-D imaging in consideration of the effect of 2-D anomaly on 1-D imaging (the resistivity of anomaly can be obtained from the resistivity contrast between anomaly and medium). The conventional methods require enormous forward computation, while this method can obtain underground resistivity structure in extremely short computation time, resulting in superior practicability. 12 refs., 7 figs.

Noguchi, K. [Waseda University, Tokyo (Japan). School of Science and Engineering; Endo, M. [Waseda University, Tokyo (Japan)

1996-10-01

339

Synchronization of circadian bioluminescence as a group-foraging strategy in cave glowworms.  

UK PubMed Central (United Kingdom)

Flies of the genus Arachnocampa are sit-and-lure predators that use bioluminescence to attract flying prey to their silk webs. Some species are most common in rainforest habitat and others inhabit both caves and rainforest. We have studied the circadian regulation of bioluminescence in two species: one found in subtropical rainforest with no known cave populations and the other found in temperate rainforest with large populations in limestone caves. The rainforest species is typical of most nocturnal animals in that individuals are entrained by the light:dark (LD) cycle to be active at night; in this case, their propensity to bioluminesce is greatest at night. The dual-habitat species shows an opposite phase response to the same entrainment; its bioluminescence propensity rhythm is entrained by LD exposure to peak during the day. Nevertheless, in LD environments, individuals do not bioluminesce during the day because ambient light inhibits their bioluminescence (negative masking), pushing bioluminescence into the dark period. This unusual and unexpected phenomenon could be related to their association with caves and has been suggested to be an adaptation of the circadian system that promotes synchronization of a colony's output of bioluminescence. Here, we use controlled laboratory experiments to show that individuals do synchronize their bioluminescence rhythms when in visual contact with each other. Entrainment of the bioluminescence rhythm to the biological photophase causes colony-wide synchronization, creating a daily sinusoidal rhythm of the intensity of bioluminescence in the many thousands of individuals making up a colony. This synchronization could provide a group-foraging advantage, allowing the colony to glow most brightly when the prey are most likely to be active.

Maynard AJ; Merritt DJ

2013-07-01

340

BLProt: prediction of bioluminescent proteins based on support vector machine and relieff feature selection  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Bioluminescence is a process in which light is emitted by a living organism. Most creatures that emit light are sea creatures, but some insects, plants, fungi etc, also emit light. The biotechnological application of bioluminescence has become routine and is considered essential for many medical and general technological advances. Identification of bioluminescent proteins is more challenging due to their poor similarity in sequence. So far, no specific method has been reported to identify bioluminescent proteins from primary sequence. Results In this paper, we propose a novel predictive method that uses a Support Vector Machine (SVM) and physicochemical properties to predict bioluminescent proteins. BLProt was trained using a dataset consisting of 300 bioluminescent proteins and 300 non-bioluminescent proteins, and evaluated by an independent set of 141 bioluminescent proteins and 18202 non-bioluminescent proteins. To identify the most prominent features, we carried out feature selection with three different filter approaches, ReliefF, infogain, and mRMR. We selected five different feature subsets by decreasing the number of features, and the performance of each feature subset was evaluated. Conclusion BLProt achieves 80% accuracy from training (5 fold cross-validations) and 80.06% accuracy from testing. The performance of BLProt was compared with BLAST and HMM. High prediction accuracy and successful prediction of hypothetical proteins suggests that BLProt can be a useful approach to identify bioluminescent proteins from sequence information, irrespective of their sequence similarity. The BLProt software is available at http://www.inb.uni-luebeck.de/tools-demos/bioluminescent%20protein/BLProt

Kandaswamy Krishna; Pugalenthi Ganesan; Hazrati Mehrnaz; Kalies Kai-Uwe; Martinetz Thomas

2011-01-01

 
 
 
 
341

Magnetic particle imaging: advancements and perspectives for real-time in vivo monitoring and image-guided therapy.  

UK PubMed Central (United Kingdom)

Magnetic particle imaging (MPI) is an emerging biomedical imaging technology that allows the direct quantitative mapping of the spatial distribution of superparamagnetic iron oxide nanoparticles. MPI's increased sensitivity and short image acquisition times foster the creation of tomographic images with high temporal and spatial resolution. The contrast and sensitivity of MPI is envisioned to transcend those of other medical imaging modalities presently used, such as magnetic resonance imaging (MRI), X-ray scans, ultrasound, computed tomography (CT), positron emission tomography (PET) and single photon emission computed tomography (SPECT). In this review, we present an overview of the recent advances in the rapidly developing field of MPI. We begin with a basic introduction of the fundamentals of MPI, followed by some highlights over the past decade of the evolution of strategies and approaches used to improve this new imaging technique. We also examine the optimization of iron oxide nanoparticle tracers used for imaging, underscoring the importance of size homogeneity and surface engineering. Finally, we present some future research directions for MPI, emphasizing the novel and exciting opportunities that it offers as an important tool for real-time in vivo monitoring. All these opportunities and capabilities that MPI presents are now seen as potential breakthrough innovations in timely disease diagnosis, implant monitoring, and image-guided therapeutics.

Pablico-Lansigan MH; Situ SF; Samia AC

2013-05-01

342

REAL-TIME DOSE RECONSTRUCTION USING DYNAMIC SIMULATION AND IMAGE GUIDED ADAPTIVE RADIOTHERAPY  

UK PubMed Central (United Kingdom)

A radiation therapy treatment method comprises imaging a subject and simulatingfour-dimensional aspects of radiotherapy. A treatment plan based on the simulationis generated to permit real-time, three-dimensional dose reconstruction atthe time of treatment. The simulation and treatment plan are used during treatmentfractions to achieve real-time image guidance.

FALLONE B. Gino; CARLONE Marco; MURRAY Brad

343

REAL-TIME DOSE RECONSTRUCTION USING DYNAMIC SIMULATION AND IMAGE GUIDED ADAPTIVE RADIOTHERAPY  

UK PubMed Central (United Kingdom)

A radiation therapy treatment method comprises imaging a subject and simulating four-dimensional aspects of radiotherapy. A treatment plan based on the simulation is generated to permit real-time, three-dimensional dose reconstruction at the time of treatment. The simulation and treatment plan are used during treatment fractions to achieve real-time image guidance.

FALLONE B GINO; CARLONE MARCO; MURRAY BRAD

344

Multimodality Imaging of Tumor Response to Doxil  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Early assessment of tumor responses to chemotherapy could enhance treatment outcomes by ensuring that, from the beginning, treatments meet the individualized needs of patients. In this study, we applied multiple modality molecular imaging techniques to pre-clinical monitoring of early tumor responses to Doxil, focusing on imaging of apoptosis.Methods: Mice bearing UM-SCC-22B human head and neck squamous cancer tumors received either PBS or 1 to 2 doses of Doxil® (doxorubicin HCl liposome injection) (10 mg/kg/dose). Bioluminescence signals from an apoptosis-responsive reporter gene were captured for apoptosis evaluation. Tumor metabolism and proliferation were assessed by 18F-FDG and 3'-18F-fluoro-3'-deoxythymidine (18F-FLT) positron emission tomography. Diffusion-weighted magnetic resonance imaging (DW-MRI) was performed to calculate averaged apparent diffusion coefficients (ADCs) for the whole tumor volume. After imaging, tumor samples were collected for histological evaluation, including terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), anti-CD31, and Ki-67 immunostaining.Results: Two doses of Doxil significantly inhibited tumor growth. Bioluminescence imaging (BLI) indicated apoptosis of tumor cells after just 1 dose of Doxil treatment, before apparent tumor shrinkage. 18F-FDG and 18F-FLT PET imaging identified decreased tumor metabolism and proliferation at later time points than those at which BLI indicated apoptosis. MRI measurements of ADC altered in response to Doxil, but only after tumors were treated with 2 doses. Decreased tumor proliferation and increased apoptotic cells were confirmed by changes of Ki-67 index and apoptotic ratio.Conclusion: Our study of tumor responses to different doses of Doxil demonstrated that it is essential to combine apoptosis imaging strategies with imaging of other critical biological or pathological pathways, such as metabolism and proliferation, to improve clinical decision making in apoptosis-related diseases and interventions.

Fan Zhang, Lei Zhu, Gang Liu, Naoki Hida, Guangming Lu, Henry S. Eden, Gang Niu, Xiaoyuan Chen

2011-01-01

345

An Internet and Intranet Based Real Time Medical Imaging System  

Directory of Open Access Journals (Sweden)

Full Text Available Today computer is an essential part of our life. The computer database is used for medical decision making. Doctors basically used to take decision on particular diesis on the help of old and current history of the patients or same diesis procured by other patients. This paper describe a tool developed in java/j2EE which enables the doctors to retrieved old record of same dieses treatment using internet and even allow them view medical image of blood slides, ECG, CT-scan, X-Ray etc. even allow them to mark and/or zoom important area of the image. It is secure and multi party medical image database consultant system.

Prashant Kumar; Ashish Vashishtha; Md. Khalid Imam Rahmani

2013-01-01

346

Using bioluminescent biosensors for hazard analysis and critical control point (HACCP) in wastewater control.  

UK PubMed Central (United Kingdom)

Starting from a new approach for water pollution control and wastewater treatment plant management, the hazard analysis and critical control point (HACCP) quality concept, the interest for the development of new rapid and sensitive methods such as bioluminescence-based methods is evident. After an introduction of the HACCP procedure, a bibliographic study of the bioluminescence potentiality is presented and discussed.

Valat C; Champiat D; Degorce-Dumas JR; Thomas O

2004-01-01

347

Optimum allocation of imaging time and minimum detectable activity in dual isotope blood pool subtraction indium-111 platelet imaging  

Energy Technology Data Exchange (ETDEWEB)

Indium-111 labeled platelet imaging is a tool for detection of thrombus formation in vascular spaces. Dual isotope blood pool subtraction may help differentiate focal platelet accumulation from blood pool activity. This study used a computer model to calculate the minimum excess-to-blood pool platelet ratio (EX/BP) and the optimum dual isotope imaging times under varied conditions of lesion size. The model simulated usual human imaging doses of 500 ..mu..Ci of In-111 platelets and 5mCi of Tc-99m labeled RBCs giving a reference cardiac blood pool region (100cc) of 10000 cpm for Tc-99m and 500 cpm for In-111. The total imaging time was fixed at 20 minutes, while the two isotope imaging times (TIn/TTc) were varied, as were the simulated lesion size (cc) and EX/BP. The relative error of the excess counts was calculated using propagation of error theory. At the critical level of detection, where the excess lesion counts equal 3 times the standard deviation, the optimum TIn/TTc and minimum Ex/BP were determined for each lesion size. For the smallest lesion size (0.1cc), the minimum detectable EX/BP ratio was 1.6, with the best TIn/TTC ratio of 18/2 minutes, and for large lesions, an EX/BP of 0.1, with a TIn/TTc of 16/4. This model provides an estimate of the sensitivity and optimizes imaging times in dual isotope subtraction platelet imaging. The model is adaptable to varying isotope doses, total imaging times and lesion size. This information will be helpful in future in- vivo imaging studies of intravascular thrombi in humans.

Machac, J.; Horowitz, S.F.; Goldsmith, S.J.; Fuster, V.

1984-01-01

348

Generation of synthetic but visually realistic time series of cardiac images combining a biophysical model and clinical images.  

UK PubMed Central (United Kingdom)

We propose a new approach for the generation of synthetic but visually realistic time series of cardiac images based on an electromechanical model of the heart and real clinical 4-D image sequences. This is achieved by combining three steps. The first step is the simulation of a cardiac motion using an electromechanical model of the heart and the segmentation of the end diastolic image of a cardiac sequence. We use biophysical parameters related to the desired condition of the simulated subject. The second step extracts the cardiac motion from the real sequence using nonrigid image registration. Finally, a synthetic time series of cardiac images corresponding to the simulated motion is generated in the third step by combining the motion estimated by image registration and the simulated one. With this approach, image processing algorithms can be evaluated as we know the ground-truth motion underlying the image sequence. Moreover, databases of visually realistic images of controls and patients can be generated for which the underlying cardiac motion and some biophysical parameters are known. Such databases can open new avenues for machine learning approaches.

Prakosa A; Sermesant M; Delingette H; Marchesseau S; Saloux E; Allain P; Villain N; Ayache N

2013-01-01

349

Off-axis quantitative phase imaging processing using CUDA: toward real-time applications.  

UK PubMed Central (United Kingdom)

We demonstrate real time off-axis Quantitative Phase Imaging (QPI) using a phase reconstruction algorithm based on NVIDIA's CUDA programming model. The phase unwrapping component is based on Goldstein's algorithm. By mapping the process of extracting phase information and unwrapping to GPU, we are able to speed up the whole procedure by more than 18.8× with respect to CPU processing and ultimately achieve video rate for mega-pixel images. Our CUDA implementation also supports processing of multiple images simultaneously. This enables our imaging system to support high speed, high throughput, and real-time image acquisition and visualization.

Pham H; Ding H; Sobh N; Do M; Patel S; Popescu G

2011-07-01

350

Off-axis quantitative phase imaging processing using CUDA: toward real-time applications.  

Science.gov (United States)

We demonstrate real time off-axis Quantitative Phase Imaging (QPI) using a phase reconstruction algorithm based on NVIDIA's CUDA programming model. The phase unwrapping component is based on Goldstein's algorithm. By mapping the process of extracting phase information and unwrapping to GPU, we are able to speed up the whole procedure by more than 18.8× with respect to CPU processing and ultimately achieve video rate for mega-pixel images. Our CUDA implementation also supports processing of multiple images simultaneously. This enables our imaging system to support high speed, high throughput, and real-time image acquisition and visualization. PMID:21750757

Pham, Hoa; Ding, Huafeng; Sobh, Nahil; Do, Minh; Patel, Sanjay; Popescu, Gabriel

2011-06-01

351

Real-time in situ Raman imaging of carbon nanotube growth  

Energy Technology Data Exchange (ETDEWEB)

In the quest for control over carbon nanotube synthesis in situ imaging has the potential to become a primary tool. Here, we show that global Raman imaging enables the observation of individual nanotubes and ensembles in real time, during growth. Individual nanotubes are detected even at 875 deg. C. Imaging and spectroscopy measurements of nanotube growth show distinct nucleation and growth phases. The first optical images of individual nanotubes captured during growth are presented.

Kaminska, K; Lefebvre, J; Austing, D G; Finnie, P [Institute for Microstructural Sciences, National Research Council, Building M-50, Montreal Road, Ottawa, ON, K1A 0R6 (Canada)

2007-04-25

352

Use of in vivo bioluminescence and MRI to determine hyperthermia-induced changes in luciferase activity under the control of an hsp70 promoter.  

UK PubMed Central (United Kingdom)

We investigated the in vivo effect of hyperthermia on the expression of heat shock proteins and MRI changes in three tumor cell lines. Three tumor cell lines (SCCVII, NIH3T3, M21) were transfected with a plasmid containing the heat shock protein 70 gene (hsp70) promoter fragment and the luciferase reporter gene, and injected into mice. Tumors of 1100 mm³ in size were exposed to five different temperatures (38, 40, 42, 44 and 46 °C) in a water bath. Bioluminescence and MRI were performed at set time intervals. The MRI scan protocol was as follows: T?-weighted spin echo?±?contrast medium, T?-weighted fast spin echo, dynamic contrast-enhanced MRI, diffusion-weighted stimulated echo acquisition mode sequence, T? time obtained on a 1.5T General Electric MRI scanner. Immunoblotting was also performed. hsp70 transcription was strongly induced at 42 and 44 °C, reaching values as high as 8531.5?±?432.1-fold above baseline in NIH3T3 tumors. At these temperatures, significant increases in the uptake of contrast medium, slope of initial enhancement, Ak(ep) values and apparent diffusion coefficient (ADC) were observed in the 8-h scan of the NIH3T3 cell line. In SCCVII tumors, ADC increased by about 23% (p?=?0.010) in the scans performed at 8, 24, 48 and 96 h. At 46 °C, luciferase activity was reduced significantly in the three cell lines. In all tumor types, a significant increase in ADC was observed, which was highest in SCCVII tumors (33.8%; p?bioluminescence results, significant Hsp70 protein production was shown by immunoblot analysis. The best correlation coefficient between luciferase activity and immunoblotting results was found for M21 tumors (r?=?0.93, p?imaging, to provide information on hsp70 transcription and protein production. The major finding of the present study was that heat-related biochemical changes in tumor tissue can be determined by MRI.

Hundt W; Schink C; Steinbach S; O'Connell-Rodwell CE; Mayer D; Burbelko M; Kießling A; Guccione S

2012-12-01

353

Use of in vivo bioluminescence and MRI to determine hyperthermia-induced changes in luciferase activity under the control of an hsp70 promoter.  

Science.gov (United States)

We investigated the in vivo effect of hyperthermia on the expression of heat shock proteins and MRI changes in three tumor cell lines. Three tumor cell lines (SCCVII, NIH3T3, M21) were transfected with a plasmid containing the heat shock protein 70 gene (hsp70) promoter fragment and the luciferase reporter gene, and injected into mice. Tumors of 1100 mm³ in size were exposed to five different temperatures (38, 40, 42, 44 and 46 °C) in a water bath. Bioluminescence and MRI were performed at set time intervals. The MRI scan protocol was as follows: T?-weighted spin echo?±?contrast medium, T?-weighted fast spin echo, dynamic contrast-enhanced MRI, diffusion-weighted stimulated echo acquisition mode sequence, T? time obtained on a 1.5T General Electric MRI scanner. Immunoblotting was also performed. hsp70 transcription was strongly induced at 42 and 44 °C, reaching values as high as 8531.5?±?432.1-fold above baseline in NIH3T3 tumors. At these temperatures, significant increases in the uptake of contrast medium, slope of initial enhancement, Ak(ep) values and apparent diffusion coefficient (ADC) were observed in the 8-h scan of the NIH3T3 cell line. In SCCVII tumors, ADC increased by about 23% (p?=?0.010) in the scans performed at 8, 24, 48 and 96 h. At 46 °C, luciferase activity was reduced significantly in the three cell lines. In all tumor types, a significant increase in ADC was observed, which was highest in SCCVII tumors (33.8%; p?bioluminescence results, significant Hsp70 protein production was shown by immunoblot analysis. The best correlation coefficient between luciferase activity and immunoblotting results was found for M21 tumors (r?=?0.93, p?imaging, to provide information on hsp70 transcription and protein production. The major finding of the present study was that heat-related biochemical changes in tumor tissue can be determined by MRI. PMID:22566294

Hundt, Walter; Schink, Christian; Steinbach, Silke; O'Connell-Rodwell, Caitlin E; Mayer, Dirk; Burbelko, Mykhaylo; Kießling, Andreas; Guccione, Samira

2012-05-06

354

Clinical validity of washout time constant images obtained by digital subtraction angiography.  

UK PubMed Central (United Kingdom)

Functional images of left ventricular myocardial perfusion were obtained using the washout time constant obtained from the analysis of digital subtraction angiograms (DSA). The results were compared with those of left ventriculography to evaluate its clinical validity. DSA examinations were performed in eight patients with old anterior myocardial infarction and in 10 control subjects. Washout time constant images of the left ventricular wall were nearly homogeneous in normal cases. On the contrary, regional heterogeneity on the washout time constant images was observed in cases of anterior infarction. The abnormal region in the washout time constant image corresponded well to the area of abnormal percent wall thickening, whereas the extent of the abnormal wall motion area tended to be broader than that of the abnormal washout time constant area or area of abnormal percent wall thickening. Thus, the washout time constant images obtained by DSA may comprise a reliable means of estimating the extent of ischemia in the myocardium.

Takeda T; Matsuda M; Akatsuka T; Ogawa T; Kakihana M; Ajisaka R; Tomizawa T; Sugishita Y; Ito I; Akisada M

1986-12-01

355

Clinical validity of washout time constant images obtained by digital subtraction angiography.  

Science.gov (United States)

Functional images of left ventricular myocardial perfusion were obtained using the washout time constant obtained from the analysis of digital subtraction angiograms (DSA). The results were compared with those of left ventriculography to evaluate its clinical validity. DSA examinations were performed in eight patients with old anterior myocardial infarction and in 10 control subjects. Washout time constant images of the left ventricular wall were nearly homogeneous in normal cases. On the contrary, regional heterogeneity on the washout time constant images was observed in cases of anterior infarction. The abnormal region in the washout time constant image corresponded well to the area of abnormal percent wall thickening, whereas the extent of the abnormal wall motion area tended to be broader than that of the abnormal washout time constant area or area of abnormal percent wall thickening. Thus, the washout time constant images obtained by DSA may comprise a reliable means of estimating the extent of ischemia in the myocardium. PMID:3323323

Takeda, T; Matsuda, M; Akatsuka, T; Ogawa, T; Kakihana, M; Ajisaka, R; Tomizawa, T; Sugishita, Y; Ito, I; Akisada, M

1986-12-01

356

Comparative bioluminescence dynamics among multiple Armillaria gallica, A. mellea, and A. tabescens genets.  

Science.gov (United States)

Bioluminescence is well known among white-spored species of Basidiomycota including several species of the white-rot wood decay genus Armillaria. Previous work demonstrated consistent differences among A. gallica, A. mellea, and A. tabescens in luminescence magnitude and in luminescence expression relative to environmental stimuli. In the present studies, temporal fluctuations in mycelial luminescence were quantitatively characterized using genets matched for geographical location. All genets derived from rhizomorphs or basdiomata were constitutively luminescent while six of 13 genets originating from mycelial fans were inconsistently luminescent. Using time series of 1000 consecutive measurements over 800 ms intervals, fluctuation patterns had significantly quantifiable structure and were not simply 'white noise'. Fluctuation patterns were qualitatively similar with alternating periods of rapid fluctuation and relative stability, regardless of luminescence magnitude. Anomalous spikes or shifts in luminescence were recorded for several genets suggesting further work to identify the transient stimuli which elicited these altered luminescence patterns. PMID:23537877

Mihail, Jeanne D

2013-02-08

357

Comparative bioluminescence dynamics among multiple Armillaria gallica, A. mellea, and A. tabescens genets.  

UK PubMed Central (United Kingdom)

Bioluminescence is well known among white-spored species of Basidiomycota including several species of the white-rot wood decay genus Armillaria. Previous work demonstrated consistent differences among A. gallica, A. mellea, and A. tabescens in luminescence magnitude and in luminescence expression relative to environmental stimuli. In the present studies, temporal fluctuations in mycelial luminescence were quantitatively characterized using genets matched for geographical location. All genets derived from rhizomorphs or basdiomata were constitutively luminescent while six of 13 genets originating from mycelial fans were inconsistently luminescent. Using time series of 1000 consecutive measurements over 800 ms intervals, fluctuation patterns had significantly quantifiable structure and were not simply 'white noise'. Fluctuation patterns were qualitatively similar with alternating periods of rapid fluctuation and relative stability, regardless of luminescence magnitude. Anomalous spikes or shifts in luminescence were recorded for several genets suggesting further work to identify the transient stimuli which elicited these altered luminescence patterns.

Mihail JD

2013-03-01

358

Classification of time series of multispectral images with limited training data.  

UK PubMed Central (United Kingdom)

Image classification usually requires the availability of reliable reference data collected for the considered image to train supervised classifiers. Unfortunately when time series of images are considered, this is seldom possible because of the costs associated with reference data collection. In most of the applications it is realistic to have reference data available for one or few images of a time series acquired on the area of interest. In this paper, we present a novel system for automatically classifying image time series that takes advantage of image(s) with an associated reference information (i.e., the source domain) to classify image(s) for which reference information is not available (i.e., the target domain). The proposed system exploits the already available knowledge on the source domain and, when possible, integrates it with a minimum amount of new labeled data for the target domain. In addition, it is able to handle possible significant differences between statistical distributions of the source and target domains. Here, the method is presented in the context of classification of remote sensing image time series, where ground reference data collection is a highly critical and demanding task. Experimental results show the effectiveness of the proposed technique. The method can work on multimodal (e.g., multispectral) images.

Demir B; Bovolo F; Bruzzone L

2013-08-01

359

A high-resolution, four-band SAR testbed with real-time image formation  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the Twin-Otter SAR Testbed developed at Sandia National Laboratories. This SAR is a flexible, adaptable testbed capable of operation on four frequency bands: Ka, Ku, X, and VHF/UHF bands. The SAR features real-time image formation at fine resolution in spotlight and stripmap modes. High-quality images are formed in real time using the overlapped subaperture (OSA) image-formation and phase gradient autofocus (PGA) algorithms.

Walker, B.; Sander, G.; Thompson, M.; Burns, B.; Fellerhoff, R.; Dubbert, D.

1996-03-01

360

A dual function fusion protein of Herpes simplex virus type 1 thymidine kinase and firefly luciferase for noninvasive in vivo imaging of gene therapy in malignant glioma  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Suicide gene therapy employing the prodrug activating system Herpes simplex virus type 1 thymidine kinase (HSV-TK)/ ganciclovir (GCV) has proven to be effective in killing experimental brain tumors. In contrast, glioma patients treated with HSV-TK/ GCV did not show significant treatment benefit, most likely due to insufficient transgene delivery to tumor cells. Therefore, this study aimed at developing a strategy for real-time noninvasive in vivo monitoring of the activity of a therapeutic gene in brain tumor cells. Methods The HSV-TK gene was fused to the firefly luciferase (Luc) gene and the fusion construct HSV-TK-Luc was expressed in U87MG human malignant glioma cells. Nude mice with subcutaneous gliomas stably expressing HSV-TK-Luc were subjected to GCV treatment and tumor response to therapy was monitored in vivo by serial bioluminescence imaging. Bioluminescent signals over time were compared with tumor volumes determined by caliper. Results Transient and stable expression of the HSV-TK-Luc fusion protein in U87MG glioma cells demonstrated close correlation of both enzyme activities. Serial optical imaging of tumor bearing mice detected in all cases GCV induced death of tumor cells expressing the fusion protein and proved that bioluminescence can be reliably used for repetitive and noninvasive quantification of HSV-TK/ GCV mediated cell kill in vivo. Conclusion This approach may represent a valuable tool for the in vivo evaluation of gene therapy strategies for treatment of malignant disease.

Söling Ariane; Theiß Christian; Jungmichel Stephanie; Rainov Nikolai G

2004-01-01

 
 
 
 
361

Real-time high-speed volumetric imaging using compressive sampling optical coherence tomography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Volumetric imaging of the Optic Nerve Head (ONH) morphometry with Optical Coherence Tomography (OCT) requires dense sampling and relatively long acquisition times. Compressive Sampling (CS) is an emerging technique to reduce volume acquisition time with minimal image degradation by sparsely sampling...

Young, Mei; Lebed, Evgeniy; Jian, Yifan; Mackenzie, Paul J.; Beg, Mirza Faisal; Sarunic, Marinko V.

362

Bioluminescência de fungos: distribuição, função e mecanismo de emissão de luz/ Fungi bioluminescence: distribution, function and mechanism of light emission  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english The emission of light by living organisms, bioluminescence, has been studied since the nineteenth century. However, some bioluminescent systems, such as fungi, remain poorly understood. The emitter, the two enzymes involved, and the reaction mechanism have not yet been unraveled. Moreover, the ecological role and evolutionary significance for fungal luminescence is also unknown. It is hoped that comprehensive research on fungal bioluminescent systems will generate knowled (more) ge and tools for academic and applied sciences. This review discusses the distribution of bioluminescent fungi on Earth, attempts to elucidate the mechanism involved in light emission, and presents preliminary results on the evolution and ecological role of fungal bioluminescence.

Oliveira, Anderson Garbuglio; Carvalho, Rodrigo Pimenta; Waldenmaier, Hans Eugene; Stevani, Cassius Vinicius

2013-01-01

363

Bioluminescência de fungos: distribuição, função e mecanismo de emissão de luz Fungi bioluminescence: distribution, function and mechanism of light emission  

Directory of Open Access Journals (Sweden)

Full Text Available The emission of light by living organisms, bioluminescence, has been studied since the nineteenth century. However, some bioluminescent systems, such as fungi, remain poorly understood. The emitter, the two enzymes involved, and the reaction mechanism have not yet been unraveled. Moreover, the ecological role and evolutionary significance for fungal luminescence is also unknown. It is hoped that comprehensive research on fungal bioluminescent systems will generate knowledge and tools for academic and applied sciences. This review discusses the distribution of bioluminescent fungi on Earth, attempts to elucidate the mechanism involved in light emission, and presents preliminary results on the evolution and ecological role of fungal bioluminescence.

Anderson Garbuglio Oliveira; Rodrigo Pimenta Carvalho; Hans Eugene Waldenmaier; Cassius Vinicius Stevani

2013-01-01

364

Fast time-resolved imaging of diffusely scattering solid phantoms for optical mammography  

Science.gov (United States)

We have performed time-resolved imaging of diffusely scattering solid phantoms containing an optical inhomogeneity with increased absorption or scattering to simulate a human breast with a tumor inside. Images based on time-domain quantities derived from measured distributions of times of flight of photons are compared to those based on Fourier components. Investigations of contrast and signal- to-noise ratio of transillumination images recorded at different exposure times, i.e. at different numbers of photons detected, show that full images of the phantoms can be obtained within a few minutes only. In addition, we demonstrate that low power picosecond semiconductor lasers are suited for fast time-resolved imaging.

Grosenick, Dirk; Danlewski, Harald; Rinneberg, Herbert H.

1996-12-01

365

Reduced isotope dose and imaging time with a high-efficiency CZT SPECT camera.  

UK PubMed Central (United Kingdom)

BACKGROUND: In light of recent focus on diagnostic imaging, cardiac SPECT imaging needs to become a shorter test with lower radiation exposure to patients. Recently introduced Cadmium Zinc Telluride (CZT) cameras have the potential to achieve both goals. METHODS: During a 2-month period patients presenting for a Tc-99m sestamibi SPECT MPI study were imaged using a CZT camera using a low-dose rest-stress protocol (5 mCi rest and 15 mCi stress doses). Patients ?250 lbs or a BMI ?35 kg/m(2) were excluded. Rest images were processed at 5- and 8-minute acquisition times and stress images at 3- and 5-minute acquisition times. A subset of patients had stress imaging performed using both conventional and CZT SPECT cameras. Image acquisition times and SPECT camera images were compared based on total counts, count rate, image quality, and summed rest and stress scores. Twelve month clinical follow-up was also obtained. RESULTS: 131 patients underwent the study protocol (age 64.9 ± 9.8 years, 54.2% male). There was no significant difference in image quality and mean summed scores between 5- and 8-minute rest images and between 3- and 5-minute stress images. When compared to a conventional SPECT camera in 27 patients, total rest and stress perfusion deficits and calculated LVEF were similar (r = 0.94 and 0.96, respectively). At 12 months there was a benign prognosis in patients with normal perfusion. The effective dose was 5.8 mSv for this protocol which is 49.2% less than conventional Tc-99m studies and 75.7% less than conventional Tl-201/Tc-99m dual isotope studies. CONCLUSIONS: New SPECT camera technology with low isotope dose significantly reduces ionizing radiation exposure and imaging times compared to traditional protocols while maintaining image quality and diagnostic accuracy.

Duvall WL; Croft LB; Ginsberg ES; Einstein AJ; Guma KA; George T; Henzlova MJ

2011-10-01

366

Study on different imaging time of late 201Tl thyroid imaging to differentiate malignant from benign thyroid nodules  

International Nuclear Information System (INIS)

[en] This study was undertaken to clarify better time to initiate the late 201Tl thyroid imaging to differentiate malignant thyroid nodules from benign ones. Thyroid images were obtained at 5 min, 1 and 3 hr after i.v. injection of 74 MBq of 201Tl chloride. The early (5 min) and late (1 or 3 hr) 201Tl images were compared in pathologically proven 38 malignant and 48 benign nodules of 83 patients. The lesion activity (LA) on the early image was visually graded as no uptake (-), slight uptake less than the surrounding thyroid tissue uptake (SITU) (±), uptake equal to the STTU (+), and uptake more than the STTU (++). The change of LA relative to the STTU from the early image to the late image was visually graded as decreasing (D), unchanged (U) or increasing (I) pattern when the LA was (±) to (++). The benign or malignant possibility at 1 hr and 3 hr in each lesion pattern was as follows: When the LA was (-) or D, the benign possibility was 95% (35/37) and 85% (39/46). When the LA was I, the malignant possibility was 96% (27/28) and 91% (21/23). When the LA is U, the diagnosis was equivocal: malignancy; 43% (9/21) at 1 hr and 59% (10/17) at 3 hr. The positive LA had a tendency to decrease with time irrespective of tumor character. The 1 hr image was statistically better than the 3 hr image as a late image. Comparative diagnosis of 5 min and 1 hr images with the criteria of I and U lesions being malignant and others being benign seems to be the best not to overlook malignant nodules: negative predictive value of 95% and sensitivity 95%. (author)

1995-01-01

367

Local time in diffusive media and applications to imaging.  

UK PubMed Central (United Kingdom)

Local time is the measure of how much time a random walk has visited a given position. In multiple scattering media, where waves are diffuse, local time measures the sensitivity of the waves to the local medium's properties. Local variations of absorption, velocity, and scattering between two measurements yield variations in the wave field. These variations are proportional to the local time of the volume where the change happened and the amplitude of variation. The wave field variations are measured using correlations and can be used as input in a inversion algorithm to produce variation maps. The present article gives the expression of the local time in dimensions one, two, and three and an expression of its fluctuations, in order to perform such inversions and estimate their accuracy.

Rossetto V

2013-08-01

368

Co-registered pulse-echo/photoacoustic transvaginal probe for real time imaging of ovarian tissue.  

UK PubMed Central (United Kingdom)

We present the design and construction of a prototype imaging probe capable of co-registered pulse-echo ultrasound and photoacoustic (optoacoustic) imaging in real time. The probe consists of 36 fibers of 200 micron core diameter each that are distributed around a commercial transvaginal ultrasound transducer, and housed in a protective shield. Its performance was demonstrated by two sets of experiments. The first set involved imaging of blood flowing through a tube mimicking a blood vessel, the second set involved imaging of human ovaries ex vivo. The results suggest that the system along with the probe has great potential for imaging and characterizing of ovarian tissue in vivo.

Kumavor PD; Alqasemi U; Tavakoli B; Li H; Yang Y; Sun X; Warych E; Zhu Q

2013-06-01

369

Resources of Digital FIR Filters Hardware Implementation in FPGAs for Digital Image Processing in Real Time  

Directory of Open Access Journals (Sweden)

Full Text Available The main image information content, from the human visual system viewing point, is focused into whole colorimetric and spatial informations. Because every image is result of some previous processes, the goal for all standard image processing methods is improvement colorimetric and spatial image parameters in relation maximum information content by the complicated and expensive systems for digital image processing in (quasi)real time [1] based on the flash signal (multi)processors. Some single-purpose applications do not need the robust and flash systems for DIP and be enough for their use single digital filters with suitable hardware implementation. In the contribution discussed problem is therefore focused on the short description of FIR digital tilters and their hardware implementation in FPGAs-Xilinx for usage in the image processing in real time include obtained experimental results.

Peter Kulla; Josef Huska; Peter Cvicela

2004-01-01

370

Image correlation spectroscopy: mapping correlations in space, time, and reciprocal space.  

UK PubMed Central (United Kingdom)

This chapter presents an overview of two recent implementations of image correlation spectroscopy (ICS). The background theory is presented for spatiotemporal image correlation spectroscopy and image cross-correlation spectroscopy (STICS and STICCS, respectively) as well as k-(reciprocal) space image correlation spectroscopy (kICS). An introduction to the background theory is followed by sections outlining procedural aspects for properly implementing STICS, STICCS, and kICS. These include microscopy image collection, sampling in space and time, sample and fluorescent probe requirements, signal to noise, and background considerations that are all required to properly implement the ICS methods. Finally, procedural steps for immobile population removal and actual implementation of the ICS analysis programs to fluorescence microscopy image time stacks are described.

Wiseman PW

2013-01-01

371

IMAGING TIME-OF-FLIGHT ION MASS SPECTROGRAPH  

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The primary objective of this project was to develop and demonstrate a new type of time-of-flight mass spectrometer having a duty cycle of unity, which is a factor of 10{sup 3}-10{sup 4} better than conventional time-of-flight spectrometers. The spectrometer concept was demonstrated, and an additional pre-filtration technique was developed and demonstrated. The two techniques are patents pending.

H. FUNSTEN

2000-11-01

372

Improvement of performances in time-domain breast DOT by the aid of image segmentation  

Science.gov (United States)

The investigations on the optical mammography have attracted many clinical attentions, since the conventional X-ray mammography has shown some deficiencies in sensitivity, specificity, security and comfortableness. In this study, we propose an image reconstruction technique of time-domain diffuse optical tomography (DOT) for the optical mammography in the first place. This technique uses the finite-element method (FEM) solution to the Laplace-transformed coupled diffusion equations as the forward model, and develops an inverse model based on a Newton-Raphson scheme. On the basis of the preliminary reconstructed image of this technique, we also present an efficient Jacobian reduction method by the aid of image segmentation to obtain a more accurate image reconstruction. The simulative experiments reveal that the performance of reconstructed image by the aid of the image segmentation makes a notable improvement on the conventional algorithm in breast phantom image.

Ma, Yiwen; Gong, Shaorun; Gao, Feng; Yang, Fang; Zhao, Huijuan; Jiang, Jingying

2008-03-01

373

Two-dimensional real-time imaging system for subtraction angiography using an iodine filter  

Energy Technology Data Exchange (ETDEWEB)

A new type of subtraction imaging system was developed using an iodine filter and a single-energy broad bandwidth monochromatized x ray. The x-ray images of coronary arteries made after intravenous injection of a contrast agent are enhanced by an energy-subtraction technique. Filter chopping of the x-ray beam switches energies rapidly, so that a nearly simultaneous pair of filtered and nonfiltered images can be made. By using a high-speed video camera, a pair of two 512 {times} 512 pixel images can be obtained within 9 ms. Three hundred eighty-four images (raw data) are stored in a 144-Mbyte frame memory. After phantom studies, {ital in} {ital vivo} subtracted images of coronary arteries in dogs were obtained at a rate of 15 images/s.

Umetani, K.; Ueda, K. (Central Research Laboratory, Hitachi, Ltd., Kokubunji, Tokyo 185 (Japan)); Takeda, T.; Anno, I.; Itai, Y. (Institute of Clinical Medicine, University of Tsukuba, Ibaraki 305 (Japan)); Akisada, M.; Nakajima, T. (Tama Health Management Center, Tachikawa, Tokyo 190 (Japan))

1992-01-01

374

In vivo dynamic process imaging using real-time optical-resolution photoacoustic microscopy.  

UK PubMed Central (United Kingdom)

The authors demonstrate in vivo dynamic process imaging using a label-free real-time optical-resolution photoacoustic microscope (OR-PAM). This reflection-mode system takes advantage of a 532-nm fiber laser source with a high pulse repetition rate of up to 600 kHz combined with a fast-scanning mirror system. Microvasculature in SCID mouse ears is imaged at near real-time (0.5 fps) for a 1×1 mm2 field of view (FOV) with micron-scale lateral resolution. We also demonstrate imaging of cardiac-induced microhemodynamics in murine microvasculature at real-time frame-rates (30 fps) over a 250×250 ?m2 FOV using real-time C-scan OR-PAM with ability to provide sustained imaging with near real-time feedback for focusing and positioning.

Shi W; Shao P; Hajireza P; Forbrich A; Zemp RJ

2013-02-01

375

Automatic segmentation of time-lapse microscopy images depicting a live Dharma embryo.  

UK PubMed Central (United Kingdom)

Biological inferences about the toxicity of chemicals reached during experiments on the zebrafish Dharma embryo can be greatly affected by the analysis of the time-lapse microscopy images depicting the embryo. Among the stages of image analysis, automatic and accurate segmentation of the Dharma embryo is the most crucial and challenging. In this paper, an accurate and automatic segmentation approach for the segmentation of the Dharma embryo data obtained by fluorescent time-lapse microscopy is proposed. Experiments performed in four stacks of 3D images over time have shown promising results.

Zacharia E; B