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Sample records for intracellular magnetic labeling

  1. Intracellular labeling and quantification process by magnetic resonance imaging using iron oxide magnetic nanoparticles in rat C6 glioma cell line; Marcacao intracelular e processo de quantificacao por imagem por ressonancia magnetica utilizando nanoparticulas magneticas de oxido de ferro em celulas da linhagem C6 de glioma de rato

    Energy Technology Data Exchange (ETDEWEB)

    Mamani, Javier Bustamante; Pavon, Lorena Favaro; Sibov, Tatiana Tais; Rossan, Fabiana; Silveira, Paulo Henrique; Cardenas, Walter Humberto; Gamarra, Lionel Fernel, E-mail: javierbm@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Amaro Junior, Edson [Departamento de Diagnostico por Imagem e Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    Objective: To assess intracellular labeling and quantification by magnetic resonance imaging using iron oxide magnetic nanoparticles coated with biocompatible materials in rat C6 glioma cells in vitro. These methods will provide direction for future trials of tumor induction in vivo as well as possible magnetic hyperthermia applications. Methods: Aminosilane, dextran, polyvinyl alcohol, and starch-coated magnetic nanoparticles were used in the qualitative assessment of C6 cell labeling via light microscopy. The influence of the transfection agent poly-L-lysine on cellular uptake was examined. The quantification process was performed by relaxometry analysis in T{sub 1} and T{sub 2} weighted phantom images. Results: Light microscopy revealed that the aminosilane-coated magnetic nanoparticles alone or complexed with poly-L-lysine showed higher cellular uptake than did the uncoated magnetic particles. The relaxactivities of the aminosilane-coated magnetic nanoparticles with a hydrodynamic diameter of 50nm to a 3-T field were r{sub 1}=(6.1 +- 0.3) x10{sup -5} ms{sup -1}mL/{mu}g, r{sub 2}=(5.3 +- 0.1) x 10{sup -4} ms{sup -1}mL/{mu}g, with a ratio of r{sub 2} / r{sub 1}{approx_equal} 9. The iron uptake in the cells was calculated by analyzing the relaxation rates (R{sub 1}and R{sub 2}) using a mathematical relationship. Conclusions: C6 glioma cells have a high uptake efficiency for aminosilane-coated magnetic nanoparticles complexed with the transfection agent poly-L-lysine. The large ratio r{sub 2} / r{sub 1}{approx_equal} 9 indicates that these magnetic nanoparticles are ideal for quantification by magnetic resonance imaging with T{sub 2}-weighted imaging techniques. (author)

  2. Pulsed magneto-motive ultrasound imaging to detect intracellular accumulation of magnetic nanoparticles

    International Nuclear Information System (INIS)

    Mehrmohammadi, Mohammad; Qu Min; Sokolov, Konstantin V; Emelianov, Stanislav Y; Ma, Li L; Johnston, Keith P; Romanovicz, Dwight K

    2011-01-01

    As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular accumulation of nanoparticles-an important part of cell-nanoparticle interaction-has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique-pulsed magneto-motive ultrasound (pMMUS)-to identify intracellular accumulation of endocytosed magnetic nanoparticles. In pMMUS imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to the signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular accumulation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular accumulation non-invasively and in real-time.

  3. Intracellular manipulation of chromatin using magnetic nanoparticles

    NARCIS (Netherlands)

    Kanger, Johannes S.; Subramaniam, Vinod; van Driel, Roel

    2008-01-01

    Magnetic tweezers are widely used for manipulating small magnetic beads inside the cell cytoplasm in order to gain insight into the structural and mechanical properties of the cytoskeleton. Here we discuss the use of magnetic tweezers for the study of nuclear architecture and the mechanical

  4. Site-Specific Bioorthogonal Labeling for Fluorescence Imaging of Intracellular Proteins in Living Cells.

    Science.gov (United States)

    Peng, Tao; Hang, Howard C

    2016-11-02

    Over the past years, fluorescent proteins (e.g., green fluorescent proteins) have been widely utilized to visualize recombinant protein expression and localization in live cells. Although powerful, fluorescent protein tags are limited by their relatively large sizes and potential perturbation to protein function. Alternatively, site-specific labeling of proteins with small-molecule organic fluorophores using bioorthogonal chemistry may provide a more precise and less perturbing method. This approach involves site-specific incorporation of unnatural amino acids (UAAs) into proteins via genetic code expansion, followed by bioorthogonal chemical labeling with small organic fluorophores in living cells. While this approach has been used to label extracellular proteins for live cell imaging studies, site-specific bioorthogonal labeling and fluorescence imaging of intracellular proteins in live cells is still challenging. Herein, we systematically evaluate site-specific incorporation of diastereomerically pure bioorthogonal UAAs bearing stained alkynes or alkenes into intracellular proteins for inverse-electron-demand Diels-Alder cycloaddition reactions with tetrazine-functionalized fluorophores for live cell labeling and imaging in mammalian cells. Our studies show that site-specific incorporation of axial diastereomer of trans-cyclooct-2-ene-lysine robustly affords highly efficient and specific bioorthogonal labeling with monosubstituted tetrazine fluorophores in live mammalian cells, which enabled us to image the intracellular localization and real-time dynamic trafficking of IFITM3, a small membrane-associated protein with only 137 amino acids, for the first time. Our optimized UAA incorporation and bioorthogonal labeling conditions also enabled efficient site-specific fluorescence labeling of other intracellular proteins for live cell imaging studies in mammalian cells.

  5. Characterization of magnetic labels for bioassays

    International Nuclear Information System (INIS)

    Lalatonne, Yoann; Benyettou, Farah; Bonnin, Dominique; Lievre, Nicole; Monod, Philippe; Lecouvey, Marc; Weinmann, Pierre; Motte, Laurence

    2009-01-01

    Magnetic nanoparticles differing by their size have been synthesized to use them for multiparametric testing, based on their differing magnetic properties. The nanoparticle has two essential roles: to act as a probe owing to its specific magnetic properties and to carry on its surface precursor groups for the covalent coupling of biological recognition molecules, such as antibodies, nucleic acids. A totally unique, newly patented, method has been used to characterize magnetic signatures using the MIAplex technology. The MIAplex reader, developed by Magnisense, measures the non-linear response of the magnetic labels when they are exposed to a multi-frequency alternating magnetic field. This specific signature based on d 2 B(H)/dH 2 was correlated to other more conventional magnetic detection methods (superconducting quantum interference devices (SQUID) and Moessbauer).

  6. Magnetic separation of algae genetically modified for increased intracellular iron uptake

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Amy [Case Western Reserve University, Cleveland, OH (United States); Cleveland Clinic, Cleveland, OH (United States); Moore, Lee R. [Cleveland Clinic, Cleveland, OH (United States); Lane, Christopher D.; Kumar, Anil; Stroff, Clayton; White, Nicolas [Phycal Inc., Cleveland, OH (United States); Xue, Wei; Chalmers, Jeffrey J. [The Ohio State University, Columbus, OH (United States); Zborowski, Maciej, E-mail: zborowm@ccf.org [Cleveland Clinic, Cleveland, OH (United States)

    2015-04-15

    Algae were investigated in the past as a potential source of biofuel and other useful chemical derivatives. Magnetic separation of algae by iron oxide nanoparticle binding to cells has been proposed by others for dewatering of cellular mass prior to lipid extraction. We have investigated feasibility of magnetic separation based on the presence of natural iron stores in the cell, such as the ferritin in Auxenochlorella protothecoides (A. protothecoides) strains. The A. protothecoides cell constructs were tested for inserted genes and for increased intracellular iron concentration by inductively coupled plasma atomic absorption (ICP–AA). They were grown in Sueoka’s modified high salt media with added vitamin B1 and increasing concentration of soluble iron compound (FeCl{sub 3} EDTA, from 1× to 8× compared to baseline). The cell magnetic separation conditions were tested using a thin rectangular flow channel pressed against interpolar gaps of a permanent magnet forming a separation system of a well-defined fluid flow and magnetic fringing field geometry (up to 2.2 T and 1000 T/m) dubbed “magnetic deposition microscopy”, or MDM. The presence of magnetic cells in suspension was detected by formation of characteristic deposition bands at the edges of the magnet interpolar gaps, amenable to optical scanning and microscopic examination. The results demonstrated increasing cellular Fe uptake with increasing Fe concentration in the culture media in wild type strain and in selected genetically-modified constructs, leading to magnetic separation without magnetic particle binding. The throughput in this study is not sufficient for an economical scale harvest. - Highlights: • Auxenochlorella protothecoides algae were genetically modified for biofuel production. • Algal iron metabolism was sufficient for their label-less magnetic separation. • High magnetic field and low flow required make the separation scale-up uneconomical.

  7. Magnetic separation of algae genetically modified for increased intracellular iron uptake

    International Nuclear Information System (INIS)

    Buck, Amy; Moore, Lee R.; Lane, Christopher D.; Kumar, Anil; Stroff, Clayton; White, Nicolas; Xue, Wei; Chalmers, Jeffrey J.; Zborowski, Maciej

    2015-01-01

    Algae were investigated in the past as a potential source of biofuel and other useful chemical derivatives. Magnetic separation of algae by iron oxide nanoparticle binding to cells has been proposed by others for dewatering of cellular mass prior to lipid extraction. We have investigated feasibility of magnetic separation based on the presence of natural iron stores in the cell, such as the ferritin in Auxenochlorella protothecoides (A. protothecoides) strains. The A. protothecoides cell constructs were tested for inserted genes and for increased intracellular iron concentration by inductively coupled plasma atomic absorption (ICP–AA). They were grown in Sueoka’s modified high salt media with added vitamin B1 and increasing concentration of soluble iron compound (FeCl 3 EDTA, from 1× to 8× compared to baseline). The cell magnetic separation conditions were tested using a thin rectangular flow channel pressed against interpolar gaps of a permanent magnet forming a separation system of a well-defined fluid flow and magnetic fringing field geometry (up to 2.2 T and 1000 T/m) dubbed “magnetic deposition microscopy”, or MDM. The presence of magnetic cells in suspension was detected by formation of characteristic deposition bands at the edges of the magnet interpolar gaps, amenable to optical scanning and microscopic examination. The results demonstrated increasing cellular Fe uptake with increasing Fe concentration in the culture media in wild type strain and in selected genetically-modified constructs, leading to magnetic separation without magnetic particle binding. The throughput in this study is not sufficient for an economical scale harvest. - Highlights: • Auxenochlorella protothecoides algae were genetically modified for biofuel production. • Algal iron metabolism was sufficient for their label-less magnetic separation. • High magnetic field and low flow required make the separation scale-up uneconomical

  8. Homogeneous Biosensing Based on Magnetic Particle Labels

    KAUST Repository

    Schrittwieser, Stefan

    2016-06-06

    The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation.

  9. Homogeneous Biosensing Based on Magnetic Particle Labels

    Science.gov (United States)

    Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang J.; Lentijo-Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Guenther, Annegret; Tschöpe, Andreas; Schotter, Joerg

    2016-01-01

    The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation. PMID:27275824

  10. Homogeneous Biosensing Based on Magnetic Particle Labels

    KAUST Repository

    Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang; Lentijo Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Guenther, Annegret; Tschö pe, Andreas; Schotter, Joerg

    2016-01-01

    The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation.

  11. Intracellular performance of tailored nanoparticle tracers in magnetic particle imaging

    Energy Technology Data Exchange (ETDEWEB)

    Arami, Hamed; Krishnan, Kannan M., E-mail: kannanmk@uw.edu [Department of Materials Science and Engineering, University of Washington, P.O. Box 352120, Seattle, Washington 98195-2120 (United States)

    2014-05-07

    Magnetic Particle Imaging (MPI) is a quantitative mass-sensitive, tracer-based imaging technique, with potential applications in various cellular imaging applications. The spatial resolution of MPI, in the first approximation, improves by decreasing the full width at half maximum (FWHM) of the field-derivative of the magnetization, dm/dH of the nanoparticle (NP) tracers. The FWHM of dm/dH depends critically on NPs’ size, size distribution, and their environment. However, there is limited information on the MPI performance of the NPs after their internalization into cells. In this work, 30 to 150 μg of the iron oxide NPs were incubated in a lysosome-like acidic buffer (0.2 ml, 20 mM citric acid, pH 4.7) and investigated by vibrating sample magnetometry, magnetic particle spectroscopy, transmission electron microscopy, and dynamic light scattering (DLS). The FWHM of the dm/dH curves of the NPs increased with incubation time and buffer to NPs ratio, consistent with a decrease in the median core size of the NPs from ∼20.1 ± 0.98 to ∼18.5 ± 3.15 nm. Further, these smaller degraded NPs formed aggregates that responded to the applied field by hysteretic reversal at higher field values and increased the FWHM. The rate of core size decrease and aggregation were inversely proportional to the concentration of the incubated NPs, due to their slower biodegradation kinetics. The results of this model experiment show that the MPI performance of the NPs in the acidic environments of the intracellular organelles (i.e., lysosomes and endosomes) can be highly dependent on their rate of internalization, residence time, and degradation.

  12. Distribution of /sup 51/Cr labelled endotoxin on tissue and intracellular organella in mice

    Energy Technology Data Exchange (ETDEWEB)

    Saito, K; Suzuki, M; Okuaki, A; Saito, M [Fukushima Medical Coll. (Japan)

    1976-10-01

    The distribution of /sup 51/Cr labelled endotoxin was investigated in mice. The degree of toxicity between non-labelled endotoxin and /sup 51/Cr labelled endotoxin did not change. /sup 51/Cr-endotoxin was distributed in the highest levels in the liver, and to a lesser degree in the intestine, lungs, spleen and kidneys. The affinity of the tissue to /sup 51/Cr-endotoxin was strongest in the liver followed by the spleen, lungs, kidneys and intestine. /sup 51/Cr-endotoxin was distributed mainly in the mitochondrial fraction and the nuclear fraction in the intracellular species. /sup 51/Cr-endotoxin was distributed only in the liver and the intestine when a small dose was administered. It was also distributed in the lungs, spleen and kidneys when a large dose was given, but the uptake in the liver was somewhat limited. /sup 51/Cr-endotoxin was distributed mainly in the liver and the spleen in the mice that survived one week.

  13. Larmor labeling by time-gradient magnetic fields

    International Nuclear Information System (INIS)

    Ioffe, Alexander; Bodnarchuk, Victor; Bussmann, Klaus; Mueller, Robert

    2007-01-01

    The Larmor labeling of neutrons, due to the Larmor precession of neutron spin in a magnetic field, opens the unique possibility for the development of neutron spin-echo (NSE) based on neutron scattering techniques, featuring an extremely high energy (momentum) resolution. Here, we present the experimental proof of a new method of the Larmor labeling using time-gradient magnetic fields

  14. Nuclear magnetic resonance studies of intracellular ions in perfused from heart

    International Nuclear Information System (INIS)

    Burnstein, D.; Fossel, E.T.

    1987-01-01

    Intracellular sodium, potassium, and lithium were observed in a perfused frog heart by nuclear magnetic resonance (NMR) spectroscopy. A perfusate buffer containing the shift reagent, dysprosium tripolyphosphate, was used in combination with mathematical filtering or presaturation of the extracellular resonance to separate the intra- and extracellular sodium NMR signals. Addition of 10 μM ouabain to the perfusate, perfusion with a zero potassium, low-calcium buffer, and replacement of 66% of the perfusate sodium with lithium resulted in changes in the intracellular sodium levels. An increase of 45% in the intracellular sodium was observed when changing the pacing rate from 0 to 60 beats/min (with proportional changes for intermediate pacing rates). The ratio of intracellular potassium to sodium concentration was determined to be 2.3 by NMR, indicating that a substantial amount of the intracellular potassium is undetectable with these NMR method. In addition, intracellular lithium was observed during perfusion with a lithium-containing perfusate

  15. Diaminobenzidine photoconversion is a suitable tool for tracking the intracellular location of fluorescently labelled nanoparticles at transmission electron microscopy

    Directory of Open Access Journals (Sweden)

    M. Malatesta

    2012-04-01

    Full Text Available Chitosan-based nanoparticles (NPs deserve particular attention as suitable drug carriers in the field of pharmaceutics, since they are able to protect the encapsulated drugs and/or improve their efficacy by making them able to cross biological barriers (such as the blood-brain barrier and reach their intracellular target sites. Understanding the intracellular location of NPs is crucial for designing drug delivery strategies. In this study, fluorescently-labelled chitosan NPs were administered in vitro to a neuronal cell line, and diaminobenzidine (DAB photoconversion was applied to correlate fluorescence and transmission electron microscopy to precisely describe the NPs intracellular fate. This technique allowed to demonstrate that chitosan NPs easily enter neuronal cells, predominantly by endocytosis; they were found both inside membrane-bounded vesicles and free in the cytosol, and were observed to accumulate around the cell nucleus.

  16. Identification of an intracellular protein that specifically interacts with photoaffinity-labeled oncogenic p21 protein

    International Nuclear Information System (INIS)

    Lee, G.; Ronai, Z.A.; Pincus, M.R.; Brandt-Rauf, P.W.; Weinstein, I.B.; Murphy, R.B.; Delohery, T.M.; Nishimura, S.; Yamaizumi, Z.

    1989-01-01

    An oncogenic 21-kDa (p21) protein (Harvey RAS protein with Val-12) has been covalently modified with a functional reagent that contains a photoactivatable aromatic azide group. This modified p21 protein has been introduced quantitatively into NIH 3T3 cells using an erythrocyte-mediated fusion technique. The introduced p21 protein was capable of inducing enhanced pinocytosis and DNA synthesis in the recipient cells. To identify the putative intracellular protein(s) that specifically interact with modified p21 protein, the cells were pulsed with [ 35 S]methionine at selected times after fusion and then UV-irradiated to activate the azide group. The resulting nitrene covalently binds to amino acid residues in adjacent proteins, thus linking the p21 protein to these proteins. The cells were then lysed, and the lysate was immunoprecipitated with the anti-p21 monoclonal antibody Y13-259. The immunoprecipitate was analyzed by SDS/PAGE to identify p21 - protein complexes. By using this technique, the authors found that three protein complexes of 51, 64, and 82 kDa were labeled specifically and reproducibly. The most prominent band is the 64-kDa protein complex that shows a time-dependent rise and fall, peaking within a 5-hr period after introduction of the p21 protein the cells. These studies provide evidence that in vitro the p21 protein becomes associated with a protein whose mass is about 43 kDa. They suggest that the formation of this complex may play a role in mediating early events involved with cell transformation induced by RAS oncogenes

  17. Identification of an intracellular protein that specifically interacts with photoaffinity-labeled oncogenic p21 protein.

    Science.gov (United States)

    Lee, G; Ronai, Z A; Pincus, M R; Brandt-Rauf, P W; Murphy, R B; Delohery, T M; Nishimura, S; Yamaizumi, Z; Weinstein, I B

    1989-11-01

    An oncogenic 21-kDa (p21) protein (Harvey RAS protein with Val-12) has been covalently modified with a functional reagent that contains a photoactivatable aromatic azide group. This modified p21 protein has been introduced quantitatively into NIH 3T3 cells using an erythrocyte-mediated fusion technique. The introduced p21 protein was capable of inducing enhanced pinocytosis and DNA synthesis in the recipient cells. To identify the putative intracellular protein(s) that specifically interact with the modified p21 protein, the cells were pulsed with [35S]methionine at selected times after fusion and then UV-irradiated to activate the azide group. The resulting nitrene covalently binds to amino acid residues in adjacent proteins, thus linking the p21 protein to these proteins. The cells were then lysed, and the lysate was immunoprecipitated with the anti-p21 monoclonal antibody Y13-259. The immunoprecipitate was analyzed by SDS/PAGE to identify p21-protein complexes. By using this technique, we found that three protein complexes of 51, 64, and 82 kDa were labeled specifically and reproducibly. The most prominent band is the 64-kDa protein complex that shows a time-dependent rise and fall, peaking within a 5-hr period after introduction of the p21 protein into the cells. These studies provide evidence that in vitro the p21 protein becomes associated with a protein whose mass is about 43 kDa. We suggest that the formation of this complex may play a role in mediating early events involved with cell transformation induced by RAS oncogenes.

  18. Rapid labeling of intracellular His-tagged proteins in living cells.

    Science.gov (United States)

    Lai, Yau-Tsz; Chang, Yuen-Yan; Hu, Ligang; Yang, Ya; Chao, Ailun; Du, Zhi-Yan; Tanner, Julian A; Chye, Mee-Len; Qian, Chengmin; Ng, Kwan-Ming; Li, Hongyan; Sun, Hongzhe

    2015-03-10

    Small molecule-based fluorescent probes have been used for real-time visualization of live cells and tracking of various cellular events with minimal perturbation on the cells being investigated. Given the wide utility of the (histidine)6-Ni(2+)-nitrilotriacetate (Ni-NTA) system in protein purification, there is significant interest in fluorescent Ni(2+)-NTA-based probes. Unfortunately, previous Ni-NTA-based probes suffer from poor membrane permeability and cannot label intracellular proteins. Here, we report the design and synthesis of, to our knowledge, the first membrane-permeable fluorescent probe Ni-NTA-AC via conjugation of NTA with fluorophore and arylazide followed by coordination with Ni(2+) ions. The probe, driven by Ni(2+)-NTA, binds specifically to His-tags genetically fused to proteins and subsequently forms a covalent bond upon photoactivation of the arylazide, leading to a 13-fold fluorescence enhancement. The arylazide is indispensable not only for fluorescence enhancement, but also for strengthening the binding between the probe and proteins. Significantly, the Ni-NTA-AC probe can rapidly enter different types of cells, even plant tissues, to target His-tagged proteins. Using this probe, we visualized the subcellular localization of a DNA repair protein, Xeroderma pigmentosum group A (XPA122), which is known to be mainly enriched in the nucleus. We also demonstrated that the probe can image a genetically engineered His-tagged protein in plant tissues. This study thus offers a new opportunity for in situ visualization of large libraries of His-tagged proteins in various prokaryotic and eukaryotic cells.

  19. Development of computational technique for labeling magnetic flux-surfaces

    International Nuclear Information System (INIS)

    Nunami, Masanori; Kanno, Ryutaro; Satake, Shinsuke; Hayashi, Takaya; Takamaru, Hisanori

    2006-03-01

    In recent Large Helical Device (LHD) experiments, radial profiles of ion temperature, electric field, etc. are measured in the m/n=1/1 magnetic island produced by island control coils, where m is the poloidal mode number and n the toroidal mode number. When the transport of the plasma in the radial profiles is numerically analyzed, an average over a magnetic flux-surface in the island is a very useful concept to understand the transport. On averaging, a proper labeling of the flux-surfaces is necessary. In general, it is not easy to label the flux-surfaces in the magnetic field with the island, compared with the case of a magnetic field configuration having nested flux-surfaces. In the present paper, we have developed a new computational technique to label the magnetic flux-surfaces. This technique is constructed by using an optimization algorithm, which is known as an optimization method called the simulated annealing method. The flux-surfaces are discerned by using two labels: one is classification of the magnetic field structure, i.e., core, island, ergodic, and outside regions, and the other is a value of the toroidal magnetic flux. We have applied the technique to an LHD configuration with the m/n=1/1 island, and successfully obtained the discrimination of the magnetic field structure. (author)

  20. Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing.

    Science.gov (United States)

    Shangguan, Jingfang; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Liu, Jinquan; Tang, Jinlu; Yang, Xue; Huang, Jin

    2016-08-02

    Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I475 nm/I545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I475 nm/I545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels.

  1. Accurate and sensitive determination of molar fractions of "1"3C-Labeled intracellular metabolites in cell cultures grown in the presence of isotopically-labeled glucose

    International Nuclear Information System (INIS)

    Fernández-Fernández, Mario; Rodríguez-González, Pablo; Hevia Sánchez, David; González-Menéndez, Pedro; Sainz Menéndez, Rosa M.; García Alonso, J. Ignacio

    2017-01-01

    This work describes a methodology based on multiple linear regression and GC-MS for the determination of molar fractions of isotopically-labeled intracellular metabolites in cell cultures. Novel aspects of this work are: i) the calculation of theoretical isotopic distributions of the different isotopologues from an experimentally measured value of % 13C enrichment of the labeled precursor ii) the calculation of the contribution of lack of mass resolution of the mass spectrometer and different fragmentation mechanism such as the loss or gain of hydrogen atoms in the EI source to measure the purity of the selected cluster for each metabolite and iii) the validation of the methodology not only by the analysis of gravimetrically prepared mixtures of isotopologues but also by the comparison of the obtained molar fractions with experimental values obtained by GC-Combustion-IRMS based on "1"3C/"1"2C isotope ratio measurements. The method is able to measure molar fractions for twenty-eight intracellular metabolites derived from glucose metabolism in cell cultures grown in the presence of "1"3C-labeled Glucose. The validation strategies demonstrate a satisfactory accuracy and precision of the proposed procedure. Also, our results show that the minimum value of "1"3C incorporation that can be accurately quantified is significantly influenced by the calculation of the spectral purity of the measured cluster and the number of "1"3C atoms of the labeled precursor. The proposed procedure was able to accurately quantify gravimetrically prepared mixtures of natural and labeled glucose molar fractions of 0.07% and mixtures of natural and labeled glycine at molar fractions down to 0.7%. The method was applied to initial studies of glucose metabolism of different prostate cancer cell lines. - Highlights: • Determination of molar fractions of "1"3C-labeled metabolites in cell cultures. • The method is based on multiple linear regression and GC-MS. • Validation of the method by

  2. Accurate and sensitive determination of molar fractions of {sup 13}C-Labeled intracellular metabolites in cell cultures grown in the presence of isotopically-labeled glucose

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Fernández, Mario [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain); Rodríguez-González, Pablo, E-mail: rodriguezpablo@uniovi.es [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain); Hevia Sánchez, David; González-Menéndez, Pedro; Sainz Menéndez, Rosa M. [University Institute of Oncology (IUOPA), University of Oviedo, Julián Clavería 6, 33006 Oviedo (Spain); García Alonso, J. Ignacio [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería 8, 33006 Oviedo (Spain)

    2017-05-29

    This work describes a methodology based on multiple linear regression and GC-MS for the determination of molar fractions of isotopically-labeled intracellular metabolites in cell cultures. Novel aspects of this work are: i) the calculation of theoretical isotopic distributions of the different isotopologues from an experimentally measured value of % 13C enrichment of the labeled precursor ii) the calculation of the contribution of lack of mass resolution of the mass spectrometer and different fragmentation mechanism such as the loss or gain of hydrogen atoms in the EI source to measure the purity of the selected cluster for each metabolite and iii) the validation of the methodology not only by the analysis of gravimetrically prepared mixtures of isotopologues but also by the comparison of the obtained molar fractions with experimental values obtained by GC-Combustion-IRMS based on {sup 13}C/{sup 12}C isotope ratio measurements. The method is able to measure molar fractions for twenty-eight intracellular metabolites derived from glucose metabolism in cell cultures grown in the presence of {sup 13}C-labeled Glucose. The validation strategies demonstrate a satisfactory accuracy and precision of the proposed procedure. Also, our results show that the minimum value of {sup 13}C incorporation that can be accurately quantified is significantly influenced by the calculation of the spectral purity of the measured cluster and the number of {sup 13}C atoms of the labeled precursor. The proposed procedure was able to accurately quantify gravimetrically prepared mixtures of natural and labeled glucose molar fractions of 0.07% and mixtures of natural and labeled glycine at molar fractions down to 0.7%. The method was applied to initial studies of glucose metabolism of different prostate cancer cell lines. - Highlights: • Determination of molar fractions of {sup 13}C-labeled metabolites in cell cultures. • The method is based on multiple linear regression and GC-MS.

  3. Instant magnetic labeling of tumor cells by ultrasound in vitro

    International Nuclear Information System (INIS)

    Mo Runyang; Yang Jian; Wu, Ed X.; Lin Shuyu

    2011-01-01

    Magnetic labeling of living cells creates opportunities for numerous biomedical applications. Here we describe an instantly cell magnetic labeling method based on ultrasound. We present a detailed study on the ultrasound performance of a simple and efficient labeling protocol for H-22 cells in vitro. High frequency focus ultrasound was investigated as an alternative method to achieve instant cell labeling with the magnetic particles without the need for adjunct agents or initiating cell cultures. Mean diameter of 168 nm dextran-T40 coated superparamagnetic iron oxide (SPIO) nanoparticles were prepared by means of classical coprecipitation in solution in our laboratory. H-22 tumor cells suspended in phosphate-buffered saline (PBS, pH=7.2) were exposed to ultrasound at 1.37 MHz for up to 120 s in the presence of SPIOs. The cellular uptake of iron oxide nanoparticles was detected by prussion blue staining. The viability of cells was determined by a trypan blue exclusion test. At 2 W power and 60 s ultrasound exposure in presence of 410 μg/ml SPIOs, H-22 cell labeling efficiency reached 69.4±6.3% and the labeled cells exhibited an iron content of 10.38±2.43 pg per cell. Furthermore, 95.2±3.2% cells remained viable. The results indicated that the ultrasound protocol could be potentially applied to label cells with large-sized magnetic particles. We also calculated the shear stress at the 2 W power and 1.37 MHz used in experiments. The results showed that the shear stress threshold for ultrasonically induced H-22 cell reparable sonoporation was 697 Pa. These findings provide a quantitative guidance in designing ultrasound protocols for cell labeling. - Highlights: → High frequency focus ultrasound can be used as a safe method for instant magnetic labeling of cells. → 8-16 times increased efficiency can be gained by ultrasound versus that by transfection agents. → Calculation of shear stress around cells provide a quantitative design for ultrasound protocols.

  4. Surface-modified magnetic nanoparticles for cell labeling

    Czech Academy of Sciences Publication Activity Database

    Zasońska, Beata Anna; Patsula, Vitalii; Stoika, R.; Horák, Daniel

    2014-01-01

    Roč. 13, č. 4 (2014), s. 63-73 ISSN 2305-7815 R&D Projects: GA MŠk(CZ) LH14318 Institutional support: RVO:61389013 Keywords : magnetic nanoparticles * surface-modified * cell labeling Subject RIV: CD - Macromolecular Chemistry

  5. Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles

    Science.gov (United States)

    Lojk, Jasna; Bregar, Vladimir B; Rajh, Maruša; Miš, Katarina; Kreft, Mateja Erdani; Pirkmajer, Sergej; Veranič, Peter; Pavlin, Mojca

    2015-01-01

    Magnetic nanoparticles (NPs) are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs) are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA) in three cell types: Chinese Hamster Ovary (CHO), mouse melanoma (B16) cell line, and primary human myoblasts (MYO). We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM) as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours’ exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS) upon 24 and 48 hours’ exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP–cell interactions on several different cell types for better prediction of possible toxic effects on different cell and tissue types in vivo. PMID:25733835

  6. Histochemical evidence for the differential surface labeling, uptake, and intracellular transport of a colloidal gold-labeled insulin complex by normal human blood cells.

    Science.gov (United States)

    Ackerman, G A; Wolken, K W

    1981-10-01

    A colloidal gold-labeled insulin-bovine serum albumin (GIA) reagent has been developed for the ultrastructural visualization of insulin binding sites on the cell surface and for tracing the pathway of intracellular insulin translocation. When applied to normal human blood cells, it was demonstrated by both visual inspection and quantitative analysis that the extent of surface labeling, as well as the rate and degree of internalization of the insulin complex, was directly related to cell type. Further, the pathway of insulin (GIA) transport via round vesicles and by tubulo-vesicles and saccules and its subsequent fate in the hemic cells was also related to cell variety. Monocytes followed by neutrophils bound the greatest amount of labeled insulin. The majority of lymphocytes bound and internalized little GIA, however, between 5-10% of the lymphocytes were found to bind considerable quantities of GIA. Erythrocytes rarely bound the labeled insulin complex, while platelets were noted to sequester large quantities of the GIA within their extracellular canalicular system. GIA uptake by the various types of leukocytic cells appeared to occur primarily by micropinocytosis and by the direct opening of cytoplasmic tubulo-vesicles and saccules onto the cell surface in regions directly underlying surface-bound GIA. Control procedures, viz., competitive inhibition of GIA labeling using an excess of unlabeled insulin in the incubation medium, preincubation of the GIA reagent with an antibody directed toward porcine insulin, and the incorporation of 125I-insulin into the GIA reagent, indicated the specificity and selectivity of the GIA histochemical procedure for the localization of insulin binding sites.

  7. Histochemical evidence for the differential surface labeling, uptake, and intracellular transport of a colloidal gold-labeled insulin complex by normal human blood cells

    International Nuclear Information System (INIS)

    Ackerman, G.A.; Wolken, K.W.

    1981-01-01

    A colloidal gold-labeled insulin-bovine serum albumin (GIA) reagent has been developed for the ultrastructural visualization of insulin binding sites on the cell surface and for tracing the pathway of intracellular insulin translocation. When applied to normal human blood cells, it was demonstrated by both visual inspection and quantitative analysis that the extent of surface labeling, as well as the rate and degree of internalization of the insulin complex, was directly related to cell type. Further, the pathway of insulin (GIA) transport via round vesicles and by tubulo-vesicles and saccules and its subsequent fate in the hemic cells was also related to cell variety. Monocytes followed by neutrophils bound the greatest amount of labeled insulin. The majority of lymphocytes bound and internalized little GIA, however, between 5-10% of the lymphocytes were found to bind considerable quantities of GIA. Erythrocytes rarely bound the labeled insulin complex, while platelets were noted to sequester large quantities of the GIA within their extracellular canalicular system. GIA uptake by the various types of leukocytic cells appeared to occur primarily by micropinocytosis and by the direct opening of cytoplasmic tubulo-vesicles and saccules onto the cell surface in regions directly underlying surface-bound GIA. Control procedures, viz., competitive inhibition of GIA labeling using an excess of unlabeled insulin in the incubation medium, preincubation of the GIA reagent with an antibody directed toward porcine insulin, and the incorporation of 125I-insulin into the GIA reagent, indicated the specificity and selectivity of the GIA histochemical procedure for the localization of insulin binding sites

  8. Magnetic lipid nanoparticles loading doxorubicin for intracellular delivery: Preparation and characteristics

    International Nuclear Information System (INIS)

    Ying Xiaoying; Du Yongzhong; Hong Linghong; Yuan Hong; Hu Fuqiang

    2011-01-01

    Tumor intracellular delivery is an effective route for targeting chemotherapy to enhance the curative effect and minimize the side effect of a drug. In this study, the magnetic lipid nanoparticles with an uptake ability by tumor cells were prepared dispersing ferroso-ferric oxide nanoparticles in aqueous phase using oleic acid (OA) as a dispersant, and following the solvent dispersion of lipid organic solution. The obtained nanoparticles with 200 nm volume average diameter and -30 mV surface zeta potential could be completely removed by external magnetic field from aqueous solution. Using doxorubicin (DOX) as a model drug, the drug-loaded magnetic lipid nanoparticles were investigated in detail, such as the effects of OA, drug and lipid content on volume average diameter, zeta potential, drug encapsulation efficiency, drug loading, and in vitro drug release. The drug loading capacity and encapsulation efficiency were enhanced with increasing drug or lipid content, reduced with increasing OA content. The in vitro drug release could be controlled by changing drug or lipid content. Cellular uptake by MCF-7 cells experiment presented the excellent internalization ability of the prepared magnetic lipid nanoparticles. These results evidenced that the present magnetic lipid nanoparticles have potential for targeting therapy of antitumor drugs. - Research highlights: → A simple solvent diffusion method was developed to prepare magnetic lipid nanoparticles. → The doxorubicin-loaded magnetic lipid nanoparticles could be controlled by preparation recipe. → Magnetic lipid nanoparticles had internalization ability into tumor cells.

  9. Influence on bionomics of endothelial progenitor cells labeling with magnetic nanoparticles

    International Nuclear Information System (INIS)

    Mai Xiaoli; Teng Gaojun; Ma Zhanlong; Sun Junhui; Zhang Yu; Gu Ning

    2008-01-01

    Objective: To explore the influence of home synthesize magnetic iron oxide (called Fe 2 O 3 -PLL) labeling on peripheral blood endothelial progenitor cells (EPCs) bionomics to provide experimental foundation for MR imaging ex and in vivo. Methods: Fe 2 O 3 was incubated with PLL for 2 hours to obtain a complex of Fe 2 O 3 -PLL. Rabbit peripheral blood mononuclear cells were isolated and EPCs were selected by adherence method. Fe 2 O 3 -PLL was used to label EPCs. Prussian blue stain and electron microscope was used for showing intracellular iron. MTF assay was assessed to evaluate the difference of growth curve between unlabeled and labeled with 25 mg/L Fe 2 O 3 -PLL. Flow cytometry was performed to analyze cell cycle, cell apoptosis and the expression of surface markers of labeled and unlabeled cells. Expressions of eNOS, KDR and vWF at mRNA levels among unlabeled and labeled EPCs were detected by real-time polymerase chain reaction. Calcium ion channel and membrane fluidity were observed and analyzed by laser confocal microscopy. Statistical analyses were used with ANOVA and t test. Results: Almost 100% cells were labeled by Fe 2 O 3 -PLL, iron-containing vesicles were intracytoplasma. There was no statistical difference in cells growth curve, cell life cycle [(93.74±3.52)%, (94.57±3.66)%] and cell apoptosis rate (12.89±1.81)%, (11.67±1.18)%) between labeling with Fe 2 O 3 -PLL at a concentration of 25 mg/L and unlabeled cells (t=0.283, P>0.05; t=0.977, P>0.05). There was also no statistical difference in relative amount of eNOS, KDR and vWF at mRNA levels and the expression of surface phenotypic markers (CD34, CD106, CD146 and KDR) between two groups (P>0.05). In addition, Labeling had little influence on calcium ion channel and didn't significantly alter cell membrane fluidity. Conclusions: The rabbit peripheral blood EPCs can be effective labeled with Fe 2 O 3 -PLL and without significant influence on cells bionomics at a low concentration of 25 mg

  10. Improved Imaging of Magnetically Labeled Cells Using Rotational Magnetomotive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Peter Cimalla

    2017-04-01

    Full Text Available In this paper, we present a reliable and robust method for magnetomotive optical coherence tomography (MM-OCT imaging of single cells labeled with iron oxide particles. This method employs modulated longitudinal and transverse magnetic fields to evoke alignment and rotation of anisotropic magnetic structures in the sample volume. Experimental evidence suggests that magnetic particles assemble themselves in elongated chains when exposed to a permanent magnetic field. Magnetomotion in the intracellular space was detected and visualized by means of 3D OCT as well as laser speckle reflectometry as a 2D reference imaging method. Our experiments on mesenchymal stem cells embedded in agar scaffolds show that the magnetomotive signal in rotational MM-OCT is significantly increased by a factor of ~3 compared to previous pulsed MM-OCT, although the solenoid’s power consumption was 16 times lower. Finally, we use our novel method to image ARPE-19 cells, a human retinal pigment epithelium cell line. Our results permit magnetomotive imaging with higher sensitivity and the use of low power magnetic fields or larger working distances for future three-dimensional cell tracking in target tissues and organs.

  11. Labelling of cultured macrophages with novel magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, J.-K. [Department of Medical Imaging, National Taiwan University Hospital and College of Medicine, Taipei 100, Taiwan (China); Institute of Biomedical Engineering, National Taiwan University, Taipei 100, Taiwan (China); Tai, M.-F. [Department of Electronic Engineering and Graduate School of Opto-Mechatronics and Materials, WuFeng Institute of Technology, 117, Chian-Kuo Rd., Sec. 2, Ming-Hsiung, Chia-yi 621, Taiwan (China)]. E-mail: mftai@mail.wfc.edu.tw; Lee, Y.-C. [Department of Physics, National Chung Cheng University, Ming-Hsiung, Chia-yi 621, Taiwan (China); Yang, C.-Y. [Department of Medical Imaging, National Taiwan University Hospital and College of Medicine, Taipei 100, Taiwan (China); Wang, H.-Y. [Department of Physics, National Chung Cheng University, Ming-Hsiung, Chia-yi 621, Taiwan (China); Liu, H.-M. [Department of Medical Imaging, National Taiwan University Hospital and College of Medicine, Taipei 100, Taiwan (China); Fang, J.-S. [Department of Material Science and Engineering, National Formosa University, Huwei, Yunlin, Taiwan (China); Chen, S.-T. [Musculoskeletal Disease Center, J.L. Pettis VA Medical Center, Department of Biochemistry Loma Linda University, Loma Linda, CA 92357 (United States)

    2006-09-15

    Magnetic resonance (MR) imaging is capable of demonstrating human anatomy and pathological conditions. Iron oxide magnetic nanoparticles (MNPs) have been used in MR imaging as liver-specific contrast medium, cellular and molecular imaging probes. Because few studies focused on the MNPs other than iron oxides, we developed FeNi alloy MNPs coated with polyethylenimine (PEI). In this study, we demonstrated PEI-coated FeNi MNPs are able to label the cells, which could be detected in MR imaging. For labelling purpose, MNPs were incubated with mouse macrophage cell line (Raw 264.7) for 24 h and these PEI-labelled FeNi alloy MNPs can be uptaken by macrophages efficiently compared with Ferucarbotran, a commercialized superparamagnetic iron oxide (SPIO) under flow cytometry measurement. Besides, these cells labelled with MNPs could be imaged in MR with the identical potency as Ferucarbotran. Further investigation of the cells using Prussian blue staining revealed that FeNi alloy MNPs inside the cells is not oxidized. This phenomenon alleviated the consideration of potential risk of nickel toxicity. We conclude that PEI-coated FeNi MNPs could be candidate for MR contrast medium.

  12. Labelling of cultured macrophages with novel magnetic nanoparticles

    International Nuclear Information System (INIS)

    Hsiao, J.-K.; Tai, M.-F.; Lee, Y.-C.; Yang, C.-Y.; Wang, H.-Y.; Liu, H.-M.; Fang, J.-S.; Chen, S.-T.

    2006-01-01

    Magnetic resonance (MR) imaging is capable of demonstrating human anatomy and pathological conditions. Iron oxide magnetic nanoparticles (MNPs) have been used in MR imaging as liver-specific contrast medium, cellular and molecular imaging probes. Because few studies focused on the MNPs other than iron oxides, we developed FeNi alloy MNPs coated with polyethylenimine (PEI). In this study, we demonstrated PEI-coated FeNi MNPs are able to label the cells, which could be detected in MR imaging. For labelling purpose, MNPs were incubated with mouse macrophage cell line (Raw 264.7) for 24 h and these PEI-labelled FeNi alloy MNPs can be uptaken by macrophages efficiently compared with Ferucarbotran, a commercialized superparamagnetic iron oxide (SPIO) under flow cytometry measurement. Besides, these cells labelled with MNPs could be imaged in MR with the identical potency as Ferucarbotran. Further investigation of the cells using Prussian blue staining revealed that FeNi alloy MNPs inside the cells is not oxidized. This phenomenon alleviated the consideration of potential risk of nickel toxicity. We conclude that PEI-coated FeNi MNPs could be candidate for MR contrast medium

  13. Noninvasive imaging of intracellular lipid metabolism in macrophages by Raman microscopy in combination with stable isotopic labeling.

    Science.gov (United States)

    Matthäus, Christian; Krafft, Christoph; Dietzek, Benjamin; Brehm, Bernhard R; Lorkowski, Stefan; Popp, Jürgen

    2012-10-16

    Monocyte-derived macrophages play a key role in atherogenesis because their transformation into foam cells is responsible for deposition of lipids in plaques within arterial walls. The appearance of cytosolic lipid droplets is a hallmark of macrophage foam cell formation, and the molecular basics involved in this process are not well understood. Of particular interest is the intracellular fate of different individual lipid species, such as fatty acids or cholesterol. Here, we utilize Raman microscopy to image the metabolism of such lipids and to trace their subsequent storage patterns. The combination of microscopic information with Raman spectroscopy provides a powerful molecular imaging method, which allows visualization at the diffraction limit of the employed laser light and biochemical characterization through associated spectral information. In order to distinguish the molecules of interest from other naturally occurring lipids spectroscopically, deuterium labels were introduced. Intracellular distribution and metabolic changes were observed for serum albumin-complexed palmitic and oleic acid and cholesterol and quantitatively evaluated by monitoring the increase in CD scattering intensities at 0.5, 1, 3, 6, 24, 30, and 36 h. This approach may also allow for investigating the cellular trafficking of other molecules, such as nutrients, metabolites, and drugs.

  14. Magnetic resonance investigation of magnetic-labeled baker's yeast cells

    International Nuclear Information System (INIS)

    Godoy Morais, J.P.M.; Azevedo, R.B.; Silva, L.P.; Lacava, Z.G.M.; Bao, S.N.; Silva, O.; Pelegrini, F.; Gansau, C.; Buske, N.; Safarik, I.; Safarikova, M.; Morais, P.C.

    2004-01-01

    In this study, the interaction of DMSA-coated magnetite nanoparticles (5 and 10 nm core-size) with Saccharomyces cerevisae was investigated using magnetic resonance (MR) and transmission electron microscopy (TEM). The TEM micrographs revealed magnetite nanoparticles attached externally to the cell wall. The MR data support the strong interaction among the nanoparticles supported by the cells. A remarkable shift in the resonance field was used as signature of particle attachment to the cell wall

  15. On the importance of sensor height variation for detection of magnetic labels by magnetoresistive sensors

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl; Wang, Shan Xiang; Hansen, Mikkel Fougt

    2015-01-01

    Magnetoresistive sensors are widely used for biosensing by detecting the signal from magnetic labels bound to a functionalized area that usually covers the entire sensor structure. Magnetic labels magnetized by a homogeneous applied magnetic field weaken and strengthen the applied field when...

  16. In vivo tracking of magnetically labeled mesenchmal stem cells injected via renal arteries in kidney failure rat

    International Nuclear Information System (INIS)

    Sun Junhui; Teng Gaojun; Ju Shenghong; Ma Zhanlong; Mai Xiaoli; Zhang Yu; Ma Ming

    2006-01-01

    Objective: To evaluate in vivo depiction and tracking for magnetically labeled bone marrow mesenchymal stern cells (MSCs) in a renal failure rat model injected intravascularly using a 1.5 T magnetic resonance imaging (MRI) system. Methods: Rat MSCs were isolated, purified, expanded and then incubated with home synthesized Fe 2 O 3 -PLL. Prussian blue stain was employed for identifying intracellular irons. An acute renal failure in rat was induced by intramuscular injection of glycerol and MSCs were injected into renal arteries of 11 recipients (labeled cells in six, unlabeled cells in five). MR images of kidneys were obtained respectively before injection of MSCs, and immediately, 1, 3, 5, and 8 clays after transplantation. MR imaging findings were analyzed, which were correlated with histological findings. Results: Rat MSCs were successfully labeled, and labeling efficiency was almost 100%. Prussian blue staining of Fe 2 O 3 -PLL labeled cells revealed the presence of iron-containing vesicles or endosomes in the cytoplasm. In the renal failure model of rats, the labeled MSCs were demonstrated as signal intensity loss in renal cortex on T 2 * -weighted MR images. The signal intensity decrease was visualized up to days 8 after transplantation. Histological analyses showed that most Prussian blue staining-positive cells were well correlated with the area where a signal intensity loss was observed in MRI. Signal intensity decrease was not detected after transplantation of unlabeled cells. Conclusion: The rat MSCs can be effectively labeled with Fe 2 O 3 -PLL. 1.5-T MR imaging seems to be a good technique to monitor the magnetically labeled MSCs in vivo in renal failure rat model intravascularly administered, which may have much more potential values for studying the engraftment of stem cells in kidneys. (authors)

  17. Alternating Magnetic Field Controlled, Multifunctional Nano-Reservoirs: Intracellular Uptake and Improved Biocompatibility

    Directory of Open Access Journals (Sweden)

    GhoshMitra Somesree

    2009-01-01

    Full Text Available Abstract Biocompatible magnetic nanoparticles hold great therapeutic potential, but conventional particles can be toxic. Here, we report the synthesis and alternating magnetic field dependent actuation of a remotely controllable, multifunctional nano-scale system and its marked biocompatibility with mammalian cells. Monodisperse, magnetic nanospheres based on thermo-sensitive polymer network poly(ethylene glycol ethyl ether methacrylate-co-poly(ethylene glycol methyl ether methacrylate were synthesized using free radical polymerization. Synthesized nanospheres have oscillating magnetic field induced thermo-reversible behavior; exhibiting desirable characteristics comparable to the widely used poly-N-isopropylacrylamide-based systems in shrinkage plus a broader volumetric transition range. Remote heating and model drug release were characterized for different field strengths. Nanospheres containing nanoparticles up to an iron concentration of 6 mM were readily taken up by neuron-like PC12 pheochromocytoma cells and had reduced toxicity compared to other surface modified magnetic nanocarriers. Furthermore, nanosphere exposure did not inhibit the extension of cellular processes (neurite outgrowth even at high iron concentrations (6 mM, indicating minimal negative effects in cellular systems. Excellent intracellular uptake and enhanced biocompatibility coupled with the lack of deleterious effects on neurite outgrowth and prior Food and Drug Administration (FDA approval of PEG-based carriers suggest increased therapeutic potential of this system for manipulating axon regeneration following nervous system injury.

  18. Francisella tularensis detection using magnetic labels and a magnetic biosensor based on frequency mixing

    International Nuclear Information System (INIS)

    Meyer, Martin H.F.; Krause, Hans-Joachim; Hartmann, Markus; Miethe, Peter; Oster, Juergen; Keusgen, Michael

    2007-01-01

    A biosensor that uses resonant coils with a special frequency-mixing technique and magnetic beads as detectable labels has been established for the detection of Francisella tularensis, the causative agent for tularemia. The detection principle is based on a sandwich immunoassay using an anti-Ft antibody for immunofiltration immobilized to ABICAP[reg] polyethylene filters, and biotinylated with streptavidin-coated magnetic beads as labels. The linear detection range of this biosensor was found to be 10 4 -10 6 cfu F. tularensis lipopolysaccharide (LPS) per ml. Tested sample matrices were physiological PBS buffer and rabbit serum

  19. Francisella tularensis detection using magnetic labels and a magnetic biosensor based on frequency mixing

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Martin H.F. [Institute for Pharmaceutical Chemistry, Philipps-Universitaet Marburg (Germany); Krause, Hans-Joachim [Institute of Bio-and Nanosystems (IBN-2), Research Center Juelich (Germany); Hartmann, Markus [Institute for Pharmaceutical Chemistry, Philipps-Universitaet Marburg (Germany); Miethe, Peter [SENOVA GmbH, Jena (Germany); Oster, Juergen [chemagen GmbH, Baesweiler (Germany); Keusgen, Michael [Institute for Pharmaceutical Chemistry, Philipps-Universitaet Marburg (Germany)]. E-mail: Keusgen@staff.uni-marburg.de

    2007-04-15

    A biosensor that uses resonant coils with a special frequency-mixing technique and magnetic beads as detectable labels has been established for the detection of Francisella tularensis, the causative agent for tularemia. The detection principle is based on a sandwich immunoassay using an anti-Ft antibody for immunofiltration immobilized to ABICAP[reg] polyethylene filters, and biotinylated with streptavidin-coated magnetic beads as labels. The linear detection range of this biosensor was found to be 10{sup 4}-10{sup 6} cfu F. tularensis lipopolysaccharide (LPS) per ml. Tested sample matrices were physiological PBS buffer and rabbit serum.

  20. Imaging of transfection and intracellular release of intact, non-labeled DNA using fluorescent nanodiamonds

    Czech Academy of Sciences Publication Activity Database

    Petráková, Vladimíra; Benson, Veronika; Bunček, M.; Fišerová, Anna; Ledvina, Miroslav; Štursa, Jan; Cígler, Petr; Nesládek, M.

    2016-01-01

    Roč. 8, č. 23 (2016), s. 12002-12012 ISSN 2040-3364 R&D Projects: GA MZd(CZ) NV15-33094A; GA MŠk LM2015056 Grant - others:OP VK(XE) CZ.1.07/2.3.00/20.0306 Institutional support: RVO:68378271 ; RVO:61388971 ; RVO:61389005 ; RVO:61388963 Keywords : single-particle tracking * resonance energy-transfer * sirna delivery * gene delivery * correlation spectroscopy * endosomal escape * mass-production * drug-delivery * quantum dots * living cells Subject RIV: BM - Solid Matter Physics ; Magnetism; CC - Organic Chemistry (UOCHB-X); EE - Microbiology, Virology (MBU-M); BG - Nuclear, Atomic and Molecular Physics, Colliders (UJF-V) Impact factor: 7.367, year: 2016

  1. In vivo intracellular oxygen dynamics in murine brain glioma and immunotherapeutic response of cytotoxic T cells observed by fluorine-19 magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Jia Zhong

    Full Text Available Noninvasive biomarkers of anti-tumoral efficacy are of great importance to the development of therapeutic agents. Tumor oxygenation has been shown to be an important indicator of therapeutic response. We report the use of intracellular labeling of tumor cells with perfluorocarbon (PFC molecules, combined with quantitative ¹⁹F spin-lattice relaxation rate (R₁ measurements, to assay tumor cell oxygen dynamics in situ. In a murine central nervous system (CNS GL261 glioma model, we visualized the impact of Pmel-1 cytotoxic T cell immunotherapy, delivered intravenously, on intracellular tumor oxygen levels. GL261 glioma cells were labeled ex vivo with PFC and inoculated into the mouse striatum. The R₁ of ¹⁹F labeled cells was measured using localized single-voxel magnetic resonance spectroscopy, and the absolute intracellular partial pressure of oxygen (pO₂ was ascertained. Three days after tumor implantation, mice were treated with 2×10⁷ cytotoxic T cells intravenously. At day five, a transient spike in pO₂ was observed indicating an influx of T cells into the CNS and putative tumor cell apoptosis. Immunohistochemistry and quantitative flow cytometry analysis confirmed that the pO₂ was causally related to the T cells infiltration. Surprisingly, the pO₂ spike was detected even though few (∼4×10⁴ T cells actually ingress into the CNS and with minimal tumor shrinkage. These results indicate the high sensitivity of this approach and its utility as a non-invasive surrogate biomarker of anti-cancer immunotherapeutic response in preclinical models.

  2. Engineering the Intracellular Micro- and Nano-environment via Magnetic Nanoparticles

    Science.gov (United States)

    Tseng, Peter

    Single cells, despite being the base unit of living organisms, possess a high degree of hierarchical structure and functional compartmentalization. This complexity exists for good reason: cells must respond efficiently and effectively to its surrounding environment by differentiating, moving, interacting, and more in order to survive or inhabit its role in the larger biological system. At the core of these responses is cellular decision-making. Cells process cues internally and externally from the environment and effect intracellular asymmetry in biochemistry and structure in order to carry out the proper biological responses. Functionalized magnetic particles have shown to be a powerful tool in interacting with biological matter, through either cell or biomolecule sorting, and the activation of biological processes. This dissertation reports on techniques utilizing manipulated magnetic nanoparticles (internalized by cells) to spatially and temporally localize intracellular cues, and examines the resulting asymmetry in biological processes generated by our methods. We first examine patterned micromagnetic elements as a simple strategy of rapidly manipulating magnetic nanoparticles throughout the intracellular space. Silicon or silicon dioxide substrates form the base for electroplated NiFe rods, which are repeated at varying size and pitch. A planarizing resin, initially SU-8, is used as the substrate layer for cellular adhesion. We demonstrate that through the manipulations of a simple external magnet, these micro-fabricated substrates can mediate rapid (under 2 s) and precise (submicron), reversible translation of magnetic nanoparticles through cellular space. Seeding cells on substrates composed of these elements allows simultaneous control of ensembles of nanoparticles over thousands of cells at a time. We believe such substrates could form the basis of magnetically based tools for the activation of biological matter. We further utilize these strategies to

  3. Poly-l-lysine-coated magnetic nanoparticles as intracellular actuators for neural guidance

    Directory of Open Access Journals (Sweden)

    Riggio C

    2012-06-01

    . Particle uptake was monitored via Prussian blue staining, intracellular iron content quantification via a ferrozine-based assay, and direct visualization by dual-beam (focused ion beam/scanning electron microscopy [FIB/SEM] analysis. Experiments were performed on human neuroblastoma SH-SY5Y cell line and primary Schwann cell cultures of the peripheral nervous system.Results: This paper reports on the synthesis and characterization of polymer-coated magnetic Fe3O4 nanoparticles with an average diameter of 73 ± 6 nm that are designed as magnetic actuators for neural guidance. The cells were able to incorporate quantities of iron up to 2 pg/cell. The intracellular distribution of MNPs obtained by optical and electronic microscopy showed large structures of MNPs crossing the cell membrane into the cytoplasm, thus rendering them suitable for magnetic manipulation by external magnetic fields. Specifically, migration experiments under external magnetic fields confirmed that these MNPs can effectively actuate the cells, thus inducing measurable migration towards predefined directions more effectively than commercial nanoparticles (fluidMAG-ARA supplied by Chemicell. There were no observable toxic effects from MNPs on cell viability for working concentrations of 10 µg/mL (EC25 of 20.8 µg/mL, compared to 12 µg/mL in fluidMAG-ARA. Cell proliferation assays performed with primary cell cultures of the peripheral nervous system confirmed moderate cytotoxicity (EC25 of 10.35 µg/mL.Conclusion: These results indicate that loading neural cells with the proposed MNPs is likely to be an effective strategy for promoting non-invasive neural regeneration through cell magnetic actuation.Keywords: magnetic nanoparticle, actuator, migration, neural regeneration

  4. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation

    NARCIS (Netherlands)

    Dittmer, W.U.; Kievit, de P.; Prins, M.W.J.; Vissers, J.L.M.; Mersch, M.E.C.; Martens, M.F.W.C.

    2008-01-01

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions

  5. Measuring spectroscopy and magnetism of extracted and intracellular magnetosomes using soft X-ray ptychography.

    Science.gov (United States)

    Zhu, Xiaohui; Hitchcock, Adam P; Bazylinski, Dennis A; Denes, Peter; Joseph, John; Lins, Ulysses; Marchesini, Stefano; Shiu, Hung-Wei; Tyliszczak, Tolek; Shapiro, David A

    2016-12-20

    Characterizing the chemistry and magnetism of magnetotactic bacteria (MTB) is an important aspect of understanding the biomineralization mechanism and function of the chains of magnetosomes (Fe 3 O 4 nanoparticles) found in such species. Images and X-ray absorption spectra (XAS) of magnetosomes extracted from, and magnetosomes in, whole Magnetovibrio blakemorei strain MV-1 cells have been recorded using soft X-ray ptychography at the Fe 2p edge. A spatial resolution of 7 nm is demonstrated. Precursor-like and immature magnetosome phases in a whole MV-1 cell were visualized, and their Fe 2p spectra were measured. Based on these results, a model for the pathway of magnetosome biomineralization for MV-1 is proposed. Fe 2p X-ray magnetic circular dichroism (XMCD) spectra have been derived from ptychography image sequences recorded using left and right circular polarization. The shape of the XAS and XMCD signals in the ptychographic absorption spectra of both sample types is identical to the shape and signals measured with conventional bright-field scanning transmission X-ray microscope. A weaker and inverted XMCD signal was observed in the ptychographic phase spectra of the extracted magnetosomes. The XMCD ptychographic phase spectrum of the intracellular magnetosomes differed from the ptychographic phase spectrum of the extracted magnetosomes. These results demonstrate that spectro-ptychography offers a superior means of characterizing the chemical and magnetic properties of MTB at the individual magnetosome level.

  6. Magnetic resonance beacon to detect intracellular microRNA during neurogenesis.

    Science.gov (United States)

    Lee, Jonghwan; Jin, Yeon A; Ko, Hae Young; Lee, Yong Seung; Heo, Hyejung; Cho, Sujeong; Kim, Soonhag

    2015-02-01

    Magnetic resonance imaging (MRI) offers great spatial resolution for viewing deep tissues and anatomy. We developed a self-assembling signal-on magnetic fluorescence nanoparticle to visualize intracellular microRNAs (miRNAs or miRs) during neurogenesis using MRI. The self-assembling nanoparticle (miR124a MR beacon) was aggregated by the incubation of three different oligonucleotides: a 3' adaptor, a 5' adaptor, and a linker containing miR124a-binding sequences. The T2-weighted magnetic resonance (MR) signal of the self-assembled nanoparticle was quenched when miR124a was absent from test tubes or was minimally expressed in cells and tissues. When miR124a was present in test tubes or highly expressed in vitro and in vivo during P19 cell neurogenesis, it hybridized with the miR124a MR beacon, causing the linker to detach, resulting in increased signal-on MRI intensity. This MR beacon can be used as a new imaging probe to monitor the miRNA-mediated regulation of cellular processes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. In vivo quantification of magnetically labelled cells by MRI relaxometry.

    Science.gov (United States)

    Gimenez, Ulysse; Lajous, Hélène; El Atifi, Michèle; Bidart, Marie; Auboiroux, Vincent; Fries, Pascal Henry; Berger, François; Lahrech, Hana

    2016-11-01

    Cellular MRI, which visualizes magnetically labelled cells (cells*), is an active research field for in vivo cell therapy and tracking. The simultaneous relaxation rate measurements (R 2 *, R 2 , R 1 ) are the basis of a quantitative cellular MRI method proposed here. U937 cells were labelled with Molday ION Rhodamine B, a bi-functional superparamagnetic and fluorescent nanoparticle (U937*). U937* viability and proliferation were not affected in vitro. In vitro relaxometry was performed in a cell concentration range of [2.5 × 10 4 -10 8 ] cells/mL. These measurements show the existence of complementary cell concentration intervals where these rates vary linearly. The juxtaposition of these intervals delineates a wide cell concentration range over which one of the relaxation rates in a voxel of an in vivo image can be converted into an absolute cell concentration. The linear regime was found at high concentrations for R 1 in the range of [10 6 - 2 × 10 8 ] cells/mL, at intermediate concentrations for R 2 in [2.5 × 10 5 - 5 × 10 7 ] cells/mL and at low concentrations for R 2 * in [8 × 10 4 - 5 × 10 6 ] cells/mL. In vivo relaxometry was performed in a longitudinal study, with labelled U937 cells injected into a U87 glioma mouse model. Using in vitro data, maps of in vivo U937* concentrations were obtained by converting one of the in vivo relaxation rates to cell concentration maps. MRI results were compared with the corresponding optical images of the same brains, showing the usefulness of our method to accurately follow therapeutic cell biodistribution in a longitudinal study. Results also demonstrate that the method quantifies a large range of magnetically labelled cells*. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  8. Simple optical measurement of the magnetic moment of magnetically labeled objects

    Energy Technology Data Exchange (ETDEWEB)

    Heidsieck, Alexandra, E-mail: aheidsieck@tum.de [Zentralinstitut für Medizintechnik, Technische Universität München (Germany); Rudigkeit, Sarah [Physics Department, Technische Universität München (Germany); Rümenapp, Christine; Gleich, Bernhard [Zentralinstitut für Medizintechnik, Technische Universität München (Germany)

    2017-04-01

    The magnetic moment of magnetically labeled cells, microbubbles or microspheres is an important optimization parameter for many targeting, delivery or separation applications. The quantification of this property is often difficult, since it depends not only on the type of incorporated nanoparticle, but also on the intake capabilities, surface properties and internal distribution. We describe a method to determine the magnetic moment of those carriers using a microscopic set-up and an image processing algorithm. In contrast to other works, we measure the diversion of superparamagnetic nanoparticles in a static fluid. The set-up is optimized to achieve a homogeneous movement of the magnetic carriers inside the magnetic field. The evaluation is automated with a customized algorithm, utilizing a set of basic algorithms, including blob recognition, feature-based shape recognition and a graph algorithm. We present example measurements for the characteristic properties of different types of carriers in combination with different types of nanoparticles. Those properties include velocity in the magnetic field as well as the magnetic moment. The investigated carriers are adherent and suspension cells, while the used nanoparticles have different sizes and coatings to obtain varying behavior of the carriers. - Highlights: • Determination of the magnetic moment of magnetic carriers. • optimized set-up achieve a homogeneous movement. • Automated evaluation with a customized algorithm. • example measurements for the properties of nanoparticle-loaded cells.

  9. Scaffold-free, label-free and nozzle-free biofabrication technology using magnetic levitational assembly.

    Science.gov (United States)

    Parfenov, Vladislav A; Koudan, Elizaveta V; Bulanova, Elena A; Karalkin, Pavel A; Pereira, Frederico DAS; Norkin, Nikita E; Knyazeva, Alisa D; Gryadunova, Anna A; Petrov, Oleg F; Vasiliev, M M; Myasnikov, Maxim; Chernikov, Valery P; Kasyanov, Vladimir A; Marchenkov, Artem Yu; Brakke, Kenneth A; Khesuani, Yusef D; Demirci, Utkan; Mironov, Vladimir A

    2018-05-31

    Tissue spheroids have been proposed as building blocks in 3D biofabrication. Conventional magnetic force-driven 2D patterning of tissue spheroids requires prior cell labeling by magnetic nanoparticles, meanwhile a label-free approach for 3D magnetic levitational assembly has been introduced. Here we present first-time report on rapid assembly of 3D tissue construct using scaffold-free, nozzle-free and label-free magnetic levitation of tissue spheroids. Chondrospheres of standard size, shape and capable to fusion have been biofabricated from primary sheep chondrocytes using non-adhesive technology. Label-free magnetic levitation was performed using a prototype device equipped with permanent magnets in presence of gadolinium (Gd3+) in culture media, which enables magnetic levitation. Mathematical modeling and computer simulations were used for prediction of magnetic field and kinetics of tissue spheroids assembly into 3D tissue constructs. First, we used polystyrene beads to simulate the assembly of tissue spheroids and to determine the optimal settings for magnetic levitation in presence of Gd3+. Second, we proved the ability of chondrospheres to assemble rapidly into 3D tissue construct in the permanent magnetic field in the presence of Gd3+. Thus, scaffold- and label-free magnetic levitation of tissue spheroids is a promising approach for rapid 3D biofabrication and attractive alternative to label-based magnetic force-driven tissue engineering. . © 2018 IOP Publishing Ltd.

  10. 188Re labeling and biodistribution of magnetic nanoparticles for the tumor targeting

    International Nuclear Information System (INIS)

    Li Guiping; Zhang Hui; Wang Yongxian; Zhang Chunfu

    2006-01-01

    Objective: To prepare 188 Re labeled monoclonal antibody (Herceptin)-coated magnetic nanoparticles for tumor targeting and to study its biodistribution in mice. Methods: Herceptin and histidine were covalently linked to the amine group upon silica-coated magnetic nanoparticles modified by N-[3-(trimethyoxysilyl)prowl]-ethylenediamine using glutaraldehyde method. The Herceptin-coated magnetic nanoparticles and Herceptin were radiolabeled with 188 Re by a direct labelling method, whereas the histidine-coated magnetic nanoparticles was radiolabeled with 188 Re using fac-[ 188 Re(CO) 3 (H 2 0) 3 ] + as a precursor. The labelling efficiency and immunoreactivity as well as labelling stability were determined. Also, the biodistribution of 188 Re-magnetic and 188 Re-Herceptin-magnetic nanoparticles were observed in mice. Results: Herceptin-coated magnetic nanoparticles was characterized by transmission electron microscope (TEM) with diameter about 60 nm, while histidine-coated magnetic nanoparticles about 30 nm. The labeling efficiency for 188 Re-Herceptin, 188 Re-magnetic nanoparticles and 188 Re-Herceptin-magnetic nanoparticles were all > 90% and had a better stability in vitro. The immunoreactivity of Herceptin linked to magnetic nanoparticles was still high. The biodistribution in mice was shown that 188 Re-magnetic nanoparticles and 188 Re-Herceptin- magnetic nanoparticles had higher radioactivity levels in blood. Magnetic nanoparticles with diameter of 30 or 60 nm had a long half-life in blood stream and were accumulated in liver. Conclusion: The efficiency and stability of labelling Herceptin-coated magnetic nanoparticles and labelling magnetic nanoparticles with 188 Re are suitable for in vivo study in tumor-beating nude mice models. (authors)

  11. Quantitative Isotope-Dilution High-Resolution-Mass-Spectrometry Analysis of Multiple Intracellular Metabolites in Clostridium autoethanogenum with Uniformly 13C-Labeled Standards Derived from Spirulina.

    Science.gov (United States)

    Schatschneider, Sarah; Abdelrazig, Salah; Safo, Laudina; Henstra, Anne M; Millat, Thomas; Kim, Dong-Hyun; Winzer, Klaus; Minton, Nigel P; Barrett, David A

    2018-04-03

    We have investigated the applicability of commercially available lyophilized spirulina ( Arthrospira platensis), a microorganism uniformly labeled with 13 C, as a readily accessible source of multiple 13 C-labeled metabolites suitable as internal standards for the quantitative determination of intracellular bacterial metabolites. Metabolites of interest were analyzed by hydrophilic-interaction liquid chromatography coupled with high-resolution mass spectrometry. Multiple internal standards obtained from uniformly (U)- 13 C-labeled extracts from spirulina were used to enable isotope-dilution mass spectrometry (IDMS) in the identification and quantification of intracellular metabolites. Extraction of the intracellular metabolites of Clostridium autoethanogenum using 2:1:1 chloroform/methanol/water was found to be the optimal method in comparison with freeze-thaw, homogenization, and sonication methods. The limits of quantification were ≤1 μM with excellent linearity for all of the calibration curves ( R 2 ≥ 0.99) for 74 metabolites. The precision and accuracy were found to be within relative standard deviations (RSDs) of 15% for 49 of the metabolites and within RSDs of 20% for all of the metabolites. The method was applied to study the effects of feeding different levels of carbon monoxide (as a carbon source) on the central metabolism and Wood-Ljungdahl pathway of C. autoethanogenum grown in continuous culture over 35 days. Using LC-IDMS with U- 13 C spirulina allowed the successful quantification of 52 metabolites in the samples, including amino acids, carboxylic acids, sugar phosphates, purines, and pyrimidines. The method provided absolute quantitative data on intracellular metabolites that was suitable for computational modeling to understand and optimize the C. autoethanogenum metabolic pathways active in gas fermentation.

  12. Superparamagnetic iron oxide nanoparticle-labeled cells as an effective vehicle for tracking the GFP gene marker using magnetic resonance imaging

    Science.gov (United States)

    Zhang, Z; Mascheri, N; Dharmakumar, R; Fan, Z; Paunesku, T; Woloschak, G; Li, D

    2010-01-01

    Background Detection of a gene using magnetic resonance imaging (MRI) is hindered by the magnetic resonance (MR) targeting gene technique. Therefore it may be advantageous to image gene-expressing cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles by MRI. Methods The GFP-R3230Ac (GFP) cell line was incubated for 24 h using SPIO nanoparticles at a concentration of 20 μg Fe/mL. Cell samples were prepared for iron content analysis and cell function evaluation. The labeled cells were imaged using fluorescent microscopy and MRI. Results SPIO was used to label GFP cells effectively, with no effects on cell function and GFP expression. Iron-loaded GFP cells were successfully imaged with both fluorescent microscopy and T2*-weighted MRI. Prussian blue staining showed intracellular iron accumulation in the cells. All cells were labeled (100% labeling efficiency). The average iron content per cell was 4.75±0.11 pg Fe/cell (P<0.05 versus control). Discussion This study demonstrates that the GFP expression of cells is not altered by the SPIO labeling process. SPIO-labeled GFP cells can be visualized by MRI; therefore, GFP, a gene marker, was tracked indirectly with the SPIO-loaded cells using MRI. The technique holds promise for monitoring the temporal and spatial migration of cells with a gene marker and enhancing the understanding of cell- and gene-based therapeutic strategies. PMID:18956269

  13. Sensitive and rapid immunoassay for parathyroid hormone using magnetic particle labels and magnetic actuation.

    Science.gov (United States)

    Dittmer, W U; de Kievit, P; Prins, M W J; Vissers, J L M; Mersch, M E C; Martens, M F W C

    2008-09-30

    A rapid method for the sensitive detection of proteins using actuated magnetic particle labels, which are measured with a giant magneto-resistive (GMR) biosensor, is described. The technique involves a 1-step sandwich immunoassay with no fluid replacement steps. The various assay binding reactions as well as the bound/free separation are entirely controlled by magnetic forces induced by electromagnets above and below the sensor chip. During the assay, particles conjugated with tracer antibodies are actuated through the sample for target capture, and rapidly brought to the sensor surface where they bind to immobilized capture antibodies. Weakly or unbound labels are removed with a magnetic force oriented away from the GMR sensor surface. For the measurement of parathyroid hormone (PTH), a detection limit in the 10 pM range is obtained with a total assay time of 15 min when 300 nm particles are used. The same sensitivity can be achieved in 5 min when 500 nm particles are used. If 500 nm particles are employed in a 15-minute assay, then 0.8 pM of PTH is detectable. The low sample volume, high analytical performance and high speed of the test coupled with the compact GMR biosensor make the system especially suitable for sensitive testing outside of laboratory environments.

  14. Detection of magnetic-labeled antibody specific recognition events by combined atomic force and magnetic force microscopy

    International Nuclear Information System (INIS)

    Hong Xia; Liu Yanmei; Li Jun; Guo Wei; Bai Yubai

    2009-01-01

    Atomic force (AFM) and magnetic force microscopy (MFM) were developed to detect biomolecular specific interaction. Goat anti-mouse immunoglobulin (anti-IgG) was covalently attached onto gold substrate modified by a self-assembly monolayer of thioctic acid via 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) activation. Magnetic-labeled IgG then specifically adsorbed onto anti-IgG surface. The morphological variation was identified by AFM. MFM was proved to be a fine assistant tool to distinguish the immunorecognized nanocomposites from the impurities by detection of the magnetic signal from magnetic-labeled IgG. It would enhance the understanding of biomolecular recognition process.

  15. Detection of magnetic-labeled antibody specific recognition events by combined atomic force and magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hong Xia [Center for Advanced Optoelectronic Functional Materials Research, Key Laboratory of UV Light-Emitting Materials and Technology, Ministry of Education, Northeast Normal University, Changchun 130024 (China); College of Chemistry, Jilin University, Changchun 130023 (China)], E-mail: xiahong@nenu.edu.cn; Liu Yanmei; Li Jun; Guo Wei; Bai Yubai [College of Chemistry, Jilin University, Changchun 130023 (China)

    2009-09-15

    Atomic force (AFM) and magnetic force microscopy (MFM) were developed to detect biomolecular specific interaction. Goat anti-mouse immunoglobulin (anti-IgG) was covalently attached onto gold substrate modified by a self-assembly monolayer of thioctic acid via 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) activation. Magnetic-labeled IgG then specifically adsorbed onto anti-IgG surface. The morphological variation was identified by AFM. MFM was proved to be a fine assistant tool to distinguish the immunorecognized nanocomposites from the impurities by detection of the magnetic signal from magnetic-labeled IgG. It would enhance the understanding of biomolecular recognition process.

  16. Degradability of superparamagnetic nanoparticles in a model of intracellular environment: follow-up of magnetic, structural and chemical properties

    Energy Technology Data Exchange (ETDEWEB)

    Levy, Michael; Wilhelm, Claire; Gazeau, Florence [Laboratoire Matiere et Systemes Complexes, UMR 7057, CNRS and Universite Paris Diderot, 10 rue Alice Domon et Leonie Duquet, 75205 Paris cedex 13 (France); Lagarde, Florence [Universite de Lyon 1, Laboratoire des Sciences Analytiques, UMR 5180 CNRS-UCBL, bat CPE, 43, boulevard du 11 novembre 1918, 69622 Villeurbanne cedex (France); Maraloiu, Valentin-Adrian; Blanchin, Marie-Genevieve [Universite de Lyon 1, Laboratoire PMCN UMR 5586 CNRS-UCBL, 69622 Villeurbanne cedex (France); Gendron, Francois, E-mail: florence.gazeau@univ-paris-diderot.fr [Institut des Nanosciences de Paris (INSP) UMR 7588, CNRS and Universite Pierre et Marie Curie 110 rue de Lourmel, 75015 Paris (France)

    2010-10-01

    The unique magnetic properties of iron oxide nanoparticles have paved the way for various biomedical applications, such as magnetic resonance cellular imaging or magnetically induced therapeutic hyperthermia. Living cells interact with nanoparticles by internalizing them within intracellular acidic compartments. Although no acute toxicity of iron oxide nanoparticles has been reported up to now, the mechanisms of nanoparticle degradation by the cellular environment are still unknown. In the organism, the long term integrity and physical state of iron-based nanoparticles are challenged by iron homeostasis. In this study, we monitored the degradation of 7 nm sized maghemite nanoparticles in a medium mimicking the intracellular environment. Magnetic nanoparticles with three distinct surface coatings, currently evaluated as MRI contrast agents, were shown to exhibit different kinetics of dissolution at an acidic pH in the presence of a citrate chelating agent. Our assessment of the physical state of the nanoparticles during degradation revealed that the magnetic properties, size distribution and structure of the remaining nanocrystals were identical to those of the initial suspension. This result suggests a model for nanoparticle degradation with rapidly dissolved nanocrystals and a reservoir of intact nanoparticles.

  17. Cell type-specific response to high intracellular loading of polyacrylic acid-coated magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Lojk J

    2015-02-01

    Full Text Available Jasna Lojk,1 Vladimir B Bregar,1 Maruša Rajh,1 Katarina Miš,2 Mateja Erdani Kreft,3 Sergej Pirkmajer,2 Peter Veranič,3 Mojca Pavlin1 1Group for Nano and Biotechnological Applications, Faculty of Electrical Engineering, 2Institute of Pathophysiology, Faculty of Medicine, 3Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia Abstract: Magnetic nanoparticles (NPs are a special type of NP with a ferromagnetic, electron-dense core that enables several applications such as cell tracking, hyperthermia, and magnetic separation, as well as multimodality. So far, superparamagnetic iron oxide NPs (SPIONs are the only clinically approved type of metal oxide NPs, but cobalt ferrite NPs have properties suitable for biomedical applications as well. In this study, we analyzed the cellular responses to magnetic cobalt ferrite NPs coated with polyacrylic acid (PAA in three cell types: Chinese Hamster Ovary (CHO, mouse melanoma (B16 cell line, and primary human myoblasts (MYO. We compared the internalization pathway, intracellular trafficking, and intracellular fate of our NPs using fluorescence and transmission electron microscopy (TEM as well as quantified NP uptake and analyzed uptake dynamics. We determined cell viability after 24 or 96 hours’ exposure to increasing concentrations of NPs, and quantified the generation of reactive oxygen species (ROS upon 24 and 48 hours’ exposure. Our NPs have been shown to readily enter and accumulate in cells in high quantities using the same two endocytic pathways; mostly by macropinocytosis and partially by clathrin-mediated endocytosis. The cell types differed in their uptake rate, the dynamics of intracellular trafficking, and the uptake capacity, as well as in their response to higher concentrations of internalized NPs. The observed differences in cell responses stress the importance of evaluation of NP–cell interactions on several different cell types for better

  18. Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

    Energy Technology Data Exchange (ETDEWEB)

    Luciani, Alain [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Wilhelm, Claire; Gazeau, Florence [Universite Paris Diderot, Batiment Condorcet, Laboratoire Matiere et Systemes Complexes, CNRS-UMR 7057, Paris Cedex (France); Bruneval, Patrick [Anatomopathologie, Hopital Europeen Georges Pompidou, Paris (France); Cunin, Patrick [Unite de Recherche Clinique, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France); Autret, Gwennhael; Clement, Olivier [Universite Rene Descartes, Hopital Europeen Georges Pompidou, Laboratoire de Recherche en Imagerie, EA 4062, Paris (France); Rahmouni, Alain [Imagerie Medicale, Faculte de Medecine Paris XII, CHU Henri Mondor, Creteil cedex (France)

    2009-05-15

    The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10{sup 6} labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

  19. Magnetic targeting of iron-oxide-labeled fluorescent hepatoma cells to the liver

    International Nuclear Information System (INIS)

    Luciani, Alain; Wilhelm, Claire; Gazeau, Florence; Bruneval, Patrick; Cunin, Patrick; Autret, Gwennhael; Clement, Olivier; Rahmouni, Alain

    2009-01-01

    The purpose of this study was to determine whether an external magnet field can induce preferential trafficking of magnetically labeled Huh7 hepatoma cells to the liver following liver cell transplantation. Huh7 hepatoma cells were labeled with anionic magnetic nanoparticles (AMNP) and tagged with a fluorescent membrane marker (PKH67). Iron-uptake was measured by magnetophoresis. Twenty C57Bl6 mice received an intrasplenic injection of 2 x 10 6 labeled cells. An external magnet (0.29 T; 25 T/m) was placed over the liver of 13 randomly selected animals (magnet group), while the remaining 7 animals served as controls. MRI (1.5 T) and confocal fluorescence microscopy (CFM) were performed 10 days post-transplantation. The presence and location of labeled cells within the livers were compared in the magnet group and controls, and confronted with histological analysis representing the standard of reference. Mean iron content per cell was 6 pg. Based on histology, labeled cells were more frequently present within recipient livers in the magnet group (p < 0.01) where their distribution was preferentially peri-vascular (p<0.05). MRI and CFM gave similar results for the overall detection of transplanted cells (kappa=0.828) and for the identification of peri-vascular cells (kappa=0.78). Application of an external magnet can modify the trafficking of transplanted cells, especially by promoting the formation of perivascular aggregates. (orig.)

  20. Label-Free Alignment of Nonmagnetic Particles in a Small Uniform Magnetic Field.

    Science.gov (United States)

    Wang, Zhaomeng; Wang, Ying; Wu, Rui Ge; Wang, Z P; Ramanujan, R V

    2018-01-01

    Label-free manipulation of biological entities can minimize damage, increase viability and improve efficiency of subsequent analysis. Understanding the mechanism of interaction between magnetic and nonmagnetic particles in an inverse ferrofluid can provide a mechanism of label-free manipulation of such entities in a uniform magnetic field. The magnetic force, induced by relative magnetic susceptibility difference between nonmagnetic particles and surrounding magnetic particles as well as particle-particle interaction were studied. Label-free alignment of nonmagnetic particles can be achieved by higher magnetic field strength (Ba), smaller particle spacing (R), larger particle size (rp1), and higher relative magnetic permeability difference between particle and the surrounding fluid (Rμr). Rμr can be used to predict the direction of the magnetic force between both magnetic and nonmagnetic particles. A sandwich structure, containing alternate layers of magnetic and nonmagnetic particle chains, was studied. This work can be used for manipulation of nonmagnetic particles in lab-on-a-chip applications.

  1. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    International Nuclear Information System (INIS)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun

    2012-01-01

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/√Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 μm with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 μm, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  2. Detecting molecules and cells labeled with magnetic particles using an atomic magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Yu Dindi; Ruangchaithaweesuk, Songtham; Yao Li; Xu Shoujun, E-mail: sxu7@uh.edu [University of Houston, Department of Chemistry (United States)

    2012-09-15

    The detection of magnetically labeled molecules and cells involves three essential parameters: sensitivity, spatial resolution, and molecular specificity. We report on the use of atomic magnetometry and its derivative techniques to achieve high performance in terms of all these parameters. With a sensitivity of 80 fT/{radical}Hz for dc magnetic fields, we show that 7,000 streptavidin-conjugated magnetic microparticles magnetized by a permanent magnet produce a magnetic field of 650 pT; this result predicts that a single such particle can be detected during one second of signal averaging. Spatial information is obtained using a scanning magnetic imaging scheme. The spatial resolution is 20 {mu}m with a detection distance of more than 1 cm; this distance is much longer than that in previous reports. The molecular specificity is achieved using force-induced remnant magnetization spectroscopy, which currently uses an atomic magnetometer for detection. As an example, we perform measurement of magnetically labeled human CD4+ T cells, whose count in the blood is the diagnostic criterion for human immunodeficiency virus infection. Magnetic particles that are specifically bound to the cells are resolved from nonspecifically bound particles and quantitatively correlate with the number of cells. The magnetic particles have an overall size of 2.8 {mu}m, with a magnetic core in nanometer regime. The combination of our techniques is predicted to be useful in molecular and cellular imaging.

  3. On-target labeling of intracellular metabolites combined with chemical mapping of individual hyphae revealing cytoplasmic relocation of isotopologues.

    Science.gov (United States)

    Hu, Jie-Bi; Chen, Yu-Chie; Urban, Pawel L

    2012-06-05

    A microscale analytical platform integrating microbial cell culture, isotopic labeling, along with visual and mass spectrometric imaging with single-cell resolution has been developed and applied in the monitoring of cellular metabolism in fungal mycelium. The method implements open chips with a two-dimensional surface pattern composed of hydrophobic and hydrophilic zones. Two hydrophilic islands are used as medium reservoirs, while the hydrophobic area constitutes the support for the growing aerial hyphae, which do not have direct contact with the medium. The first island, containing (12)C(6)-glucose medium, was initially inoculated with the mycelium (Neurospora crassa), and following the initial incubation period, the hyphae progressed toward the second medium island, containing an isotopically labeled substrate ((13)C(6)-glucose). The (13)C atoms were gradually incorporated into cellular metabolites, which was revealed by MALDI-MS. The fate of the chitin-biosynthesis precursor, uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), was monitored by recording mass spectra with characteristic isotopic patterns, which indicated the presence of various (12)C/(13)C isotopologues. The method enabled mapping the (13)C-labeled UDP-GlcNAc in fungal mycelium and recording its redistribution in hyphae, directly on the chip.

  4. Nanohybrids with Magnetic and Persistent Luminescence Properties for Cell Labeling, Tracking, In Vivo Real-Time Imaging, and Magnetic Vectorization.

    Science.gov (United States)

    Teston, Eliott; Maldiney, Thomas; Marangon, Iris; Volatron, Jeanne; Lalatonne, Yoann; Motte, Laurence; Boisson-Vidal, Catherine; Autret, Gwennhael; Clément, Olivier; Scherman, Daniel; Gazeau, Florence; Richard, Cyrille

    2018-04-01

    Once injected into a living organism, cells diffuse or migrate around the initial injection point and become impossible to be visualized and tracked in vivo. The present work concerns the development of a new technique for therapeutic cell labeling and subsequent in vivo visualization and magnetic retention. It is hypothesized and subsequently demonstrated that nanohybrids made of persistent luminescence nanoparticles and ultrasmall superparamagnetic iron oxide nanoparticles incorporated into a silica matrix can be used as an effective nanoplatform to label therapeutic cells in a nontoxic way in order to dynamically track them in real-time in vitro and in living mice. As a proof-of-concept, it is shown that once injected, these labeled cells can be visualized and attracted in vivo using a magnet. This first step suggests that these nanohybrids represent efficient multifunctional nanoprobes for further imaging guided cell therapies development. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Mapping the intracellular distribution of carbon nanotubes after targeted delivery to carcinoma cells using confocal Raman imaging as a label-free technique

    International Nuclear Information System (INIS)

    Lamprecht, C; Unterauer, B; Plochberger, B; Brameshuber, M; Hinterdorfer, P; Ebner, A; Gierlinger, N; Hild, S; Heister, E

    2012-01-01

    The uptake of carbon nanotubes (CNTs) by mammalian cells and their distribution within cells is being widely studied in recent years due to their increasing use for biomedical purposes. The two main imaging techniques used are confocal fluorescence microscopy and transmission electron microscopy (TEM). The former, however, requires labeling of the CNTs with fluorescent dyes, while the latter is a work-intensive technique that is unsuitable for in situ bio-imaging. Raman spectroscopy, on the other hand, presents a direct, straightforward and label-free alternative. Confocal Raman microscopy can be used to image the CNTs inside cells, exploiting the strong Raman signal connected to different vibrational modes of the nanotubes. In addition, cellular components, such as the endoplasmic reticulum and the nucleus, can be mapped. We first validate our method by showing that only when using the CNTs’ G band for intracellular mapping accurate results can be obtained, as mapping of the radial breathing mode (RBM) only shows a small fraction of CNTs. We then take a closer look at the exact localization of the nanotubes inside cells after folate receptor-mediated endocytosis and show that, after 8-10 h incubation, the majority of CNTs are localized around the nucleus. In summary, Raman imaging has enormous potential for imaging CNTs inside cells, which is yet to be fully realized. (paper)

  6. Breast cancer cells synchronous labeling and separation based on aptamer and fluorescence-magnetic silica nanoparticles

    Science.gov (United States)

    Wang, Qiu-Yue; Huang, Wei; Jiang, Xing-Lin; Kang, Yan-Jun

    2018-01-01

    In this work, an efficient method based on biotin-labeled aptamer and streptavidin-conjugated fluorescence-magnetic silica nanoprobes (FITC@Fe3O4@SiNPs-SA) has been established for human breast carcinoma MCF-7 cells synchronous labeling and separation. Carboxyl-modified fluorescence-magnetic silica nanoparticles (FITC@Fe3O4@SiNPs-COOH) were first synthesized using the Stöber method. Streptavidin (SA) was then conjugated to the surface of FITC@Fe3O4@SiNPs-COOH. The MCF-7 cell suspension was incubated with biotin-labeled MUC-1 aptamer. After centrifugation and washing, the cells were then treated with FITC@Fe3O4@SiNPs-SA. Afterwards, the mixtures were separated by a magnet. The cell-probe conjugates were then imaged using fluorescent microscopy. The results show that the MUC-1 aptamer could recognize and bind to the targeted cells with high affinity and specificity, indicating the prepared FITC@Fe3O4@SiNPs-SA with great photostability and superparamagnetism could be applied effectively in labeling and separation for MCF-7 cell in suspension synchronously. In addition, the feasibility of MCF-7 cells detection in peripheral blood was assessed. The results indicate that the method above is also applicable for cancer cells synchronous labeling and separation in complex biological system.

  7. Increasing magnetite contents of polymeric magnetic particles dramatically improves labeling of neural stem cell transplant populations.

    Science.gov (United States)

    Adams, Christopher F; Rai, Ahmad; Sneddon, Gregor; Yiu, Humphrey H P; Polyak, Boris; Chari, Divya M

    2015-01-01

    Safe and efficient delivery of therapeutic cells to sites of injury/disease in the central nervous system is a key goal for the translation of clinical cell transplantation therapies. Recently, 'magnetic cell localization strategies' have emerged as a promising and safe approach for targeted delivery of magnetic particle (MP) labeled stem cells to pathology sites. For neuroregenerative applications, this approach is limited by the lack of available neurocompatible MPs, and low cell labeling achieved in neural stem/precursor populations. We demonstrate that high magnetite content, self-sedimenting polymeric MPs [unfunctionalized poly(lactic acid) coated, without a transfecting component] achieve efficient labeling (≥90%) of primary neural stem cells (NSCs)-a 'hard-to-label' transplant population of major clinical relevance. Our protocols showed high safety with respect to key stem cell regenerative parameters. Critically, labeled cells were effectively localized in an in vitro flow system by magnetic force highlighting the translational potential of the methods used. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Improved calculation of the equilibrium magnetization of arterial blood in arterial spin labeling

    DEFF Research Database (Denmark)

    Ahlgren, André; Wirestam, Ronnie; Knutsson, Linda

    2018-01-01

    PURPOSE: To propose and assess an improved method for calculating the equilibrium magnetization of arterial blood ( M0a), used for calibration of perfusion estimates in arterial spin labeling. METHODS: Whereas standard M0a calculation is based on dividing a proton density-weighted image by an ave...

  9. Magnetic and/or electric label assisted detection system and method

    NARCIS (Netherlands)

    2008-01-01

    A detection system is described for detecting analytes in a fluid sample. The detection system comprises a transporting means for transporting magnetic and/or elec. labels after interaction between the sample fluid and the reagents towards a detection receptacle. The detection receptacle is

  10. Labeling of macrophages using bacterial magnetosomes and their characterization by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hartung, Annegret [Medical Physics Group, Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany) and Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany)]. E-mail: annegret.hartung@med.uni-jena.de; Lisy, Marcus R. [Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany); Herrmann, Karl-Heinz [Medical Physics Group, Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany); Hilger, Ingrid [Experimental Radiology, Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany); Schueler, Dirk [Max-Planck Institute for Marine Microbiology, Bremen (Germany); Lang, Claus [Max-Planck Institute for Marine Microbiology, Bremen (Germany); Bellemann, Matthias E. [Department of Biomedical Engineering, University of Applied Sciences, Jena (Germany); Kaiser, Werner A. [Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany); Reichenbach, Juergen R. [Medical Physics Group, Institute for Diagnostic and Interventional Radiology, Friedrich-Schiller University, Jena (Germany)

    2007-04-15

    This work investigated macrophages labeled with magnetosomes for the possible detection of inflammations by MR molecular imaging. Pure magnetosomes and macrophages containing magnetosomes were analyzed using a clinical 1.5 T MR-scanner. Relaxivities of magnetosomes and relaxation rates of cells containing magnetosomes were determined. Peritonitis was induced in two mice. T {sub 1}, T {sub 2} and T {sub 2}* weighted images were acquired following injection of the probes. Pure magnetosomes and labeled cells showed slight effects on T {sub 1}, but strong effects on T {sub 2} and T {sub 2}* images. Labeled macrophages were located with magnetic resonance imaging (MRI) in the colon area, thus demonstrating the feasibility of the proposed approach.

  11. Potentials and Challenges for Arterial Spin Labeling in Pharmacological Magnetic Resonance Imaging

    OpenAIRE

    Wang, Danny J. J.; Chen, Yufen; Fernández-Seara, María A.; Detre, John A.

    2011-01-01

    Pharmacological magnetic resonance imaging (phMRI) is increasingly being used in drug discovery and development to speed the translation from the laboratory to the clinic. The two primary methods in phMRI include blood-oxygen-level-dependent (BOLD) contrast and arterial spin-labeled (ASL) perfusion MRI. BOLD contrast has been widely applied in existing phMRI studies. However, because of the lack of absolute quantification and poor reproducibility over time scales longer than hours or across s...

  12. Magnetic labeling and in vitro MR imaging of rat bone marrow mesenchymal stem cells

    International Nuclear Information System (INIS)

    Cai Jinhua; Feng Gansheng; Wu Hanping; Wang Xin; Li Chuan; Zhao Jiannong; Guo Daqin; Yu Guorong; Liu Guanxing; Wang Shiyi

    2006-01-01

    Objective: To label rat bone marrow mesenchymal stem cells with feridex combined with poly-l-lysine (PLL), and to determine the feasibility of detection of magnetically labeled stem cells with MR imaging. Methods: Feridex were incubated with PLL for 1 hour to obtain a complex of feridex-PLL. Mesenchymal stem cells isolated from the bone marrows of Wistar rats were cultured and expanded. By the 4th passage, cells were co-incubated overnight with the feridex-PLL complex. Prussian blue staining for demonstrating intracytoplastic nanoparticles and trypan-blue exclusion test for cell viability were performed respectively at 24 h, 1 w, 2 w, 3 w after labeling. MR imaging of cell suspensions was performed by using T 1 WI, T 2 WI and T 2 * WI sequences at a clinical 1.5 T MR system. Results: Numerous intracytoplastic iron particles were stained with Prussian blue. With division of stern cells, the stained particles were seen decreased gradually. Trypan blue exclusion test at 24 h, 1 w, 2 w and 3 w showed that the viability of the labeled cells was 91.00%, 93.00%, 91.75%, and 92.50%, not significantly different with that of nonlabeled cells (P>0.05). For 10 3 , 10 4 and l0 5 cells, T 2 signal intensity decreased by 63.75%, 82.31% and 91.92% respectively, T 2 * signal intensity decreased by 68.24%, 83.01%, and 93.94% respectively. For 10 5 labeled cells, T 2 * signal intensity decreased by 93.75%, 75.92%, 41.75% and 8.83 % respectively at 24 h, 1 w, 2 w and 3 w after labeling. Conclusion: Magnetic labeling of rat bone marrow stem cells with feridex-PLL complex is feasible, efficient and safe. T 2 * WI is the most sensitive sequence to detect the labeled cells. The degree of T 2 signal decreasing may be related to the cell count and division phase. (authors)

  13. Metabolic regulation in Streptomyces parvulus during actinomycin D synthesis, studied with 13C- and 15N-labeled precursors by 13C and 15N nuclear magnetic resonance spectroscopy and by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Inbar, L.; Lapidot, A.

    1988-01-01

    Recent studies have suggested that the onset of synthesis of actinomycin D in Streptomyces is due to a release from L-glutamate catabolic repression. In the present investigation we showed that S. parvulus has the capacity to maintain high levels of intracellular glutamate during the synthesis of actinomycin D. The results seem contradictory, since actinomycin D synthesis cannot start before a release from L-glutamate catabolic repression, but a relatively high intracellular pool of glutamate is needed for the synthesis of actinomycin D. Utilizing different labeled precursors, D-[U- 13 C]fructose and 13 C- and 15 N-labeled L-glutamate, and nuclear magnetic resonance techniques, we showed that carbon atoms of an intracellular glutamate pool of S. parvulus were not derived biosynthetically from the culture medium glutamte source but rather from D-fructose catabolism. A new intracellular pyrimidine derivative whose nitrogen and carbon skeletons were derived from exogenous L-glutamate was obtained as the main glutamate metabolite. Another new pyrimidine derivative that had a significantly reduced intracellular mobility and that was derived from D-fructose catabolism was identified in the cell extracts of S. parvulus during actinomycin D synthesis. These pyrimidine derivatives may serve as a nitrogen store for actinomycin D synthesis. In the present study, the N-trimethyl group of a choline derivative was observed by 13 C nuclear magnetic resonance spectroscopy in growing S. parvulus cells. The choline group, as well as the N-methyl groups of sarcosine, N-methyl-valine, and the methyl groups of an actinomycin D chromophore, arose from D-fructose catabolism. The 13 C enrichments found in the peptide moieties of actinomycin D were in accordance with a mechanism of actinomycin D synthesis from L-glutamate and D-fructose

  14. Magnetic resonance imaging of single co-labeled mesenchymal stromal cells after intracardial injection in mice

    International Nuclear Information System (INIS)

    Salamon, J.; Adam, G.; Peldschus, K.; Wicklein, D.; Schumacher, U.; Didie, M.; Lange, C.

    2014-01-01

    Purpose: The aim of this study was to establish co-labeling of mesenchymal stromal cells (MSC) for the detection of single MSC in-vivo by MRI and histological validation. Materials and Methods: Mouse MSC were co-labeled with fluorescent iron oxide micro-particles and carboxyfluorescein succinimidyl ester (CFSE). The cellular iron content was determined by atomic absorption spectrometry. Cell proliferation and expression of characteristic surface markers were determined by flow cytometry. The chondrogenic differentiation capacity was assessed. Different amounts of cells (n1 = 5000, n2 = 15 000, n3 = 50 000) were injected into the left heart ventricle of 12 mice. The animals underwent sequential MRI on a clinical 3.0T scanner (Intera, Philips Medical Systems, Best, The Netherlands). For histological validation cryosections were examined by fluorescent microscopy. Results: Magnetic and fluorescent labeling of MSC was established (mean cellular iron content 23.6 ± 3 pg). Flow cytometry showed similar cell proliferation and receptor expression of labeled and unlabeled MSC. Chondrogenic differentiation of labeled MSC was verified. After cell injection MRI revealed multiple signal voids in the brain and fewer signal voids in the kidneys. In the brain, an average of 4.6 ± 1.2 (n1), 9.0 ± 3.6 (n2) and 25.0 ± 1.0 (n3) signal voids were detected per MRI slice. An average of 8.7 ± 3.1 (n1), 22.0 ± 6.1 (n2) and 89.8 ± 6.5 (n3) labeled cells per corresponding stack of adjacent cryosections could be detected in the brain. Statistical correlation of the numbers of MRI signal voids in the brain and single MSC found by histology revealed a correlation coefficient of r = 0.91. Conclusion: The study demonstrates efficient magnetic and fluorescent co-labeling of MSC and their detection on a single cell level in mice by in-vivo MRI and histology. The described techniques may broaden the methods for in-vivo tracking of MSC. (orig.)

  15. Magnetic separation of encapsulated islet cells labeled with superparamagnetic iron oxide nano particles.

    Science.gov (United States)

    Mettler, Esther; Trenkler, Anja; Feilen, Peter J; Wiegand, Frederik; Fottner, Christian; Ehrhart, Friederike; Zimmermann, Heiko; Hwang, Yong Hwa; Lee, Dong Yun; Fischer, Stefan; Schreiber, Laura M; Weber, Matthias M

    2013-01-01

    Islet cell transplantation is a promising option for the restoration of normal glucose homeostasis in patients with type 1 diabetes. Because graft volume is a crucial issue in islet transplantations for patients with diabetes, we evaluated a new method for increasing functional tissue yield in xenogeneic grafts of encapsulated islets. Islets were labeled with three different superparamagnetic iron oxide nano particles (SPIONs; dextran-coated SPION, siloxane-coated SPION, and heparin-coated SPION). Magnetic separation was performed to separate encapsulated islets from the empty capsules, and cell viability and function were tested. Islets labeled with 1000 μg Fe/ml dextran-coated SPIONs experienced a 69.9% reduction in graft volume, with a 33.2% loss of islet-containing capsules. Islets labeled with 100 μg Fe/ml heparin-coated SPIONs showed a 46.4% reduction in graft volume, with a 4.5% loss of capsules containing islets. No purification could be achieved using siloxane-coated SPIONs due to its toxicity to the primary islets. SPION labeling of islets is useful for transplant purification during islet separation as well as in vivo imaging after transplantation. Furthermore, purification of encapsulated islets can also reduce the volume of the encapsulated islets without impairing their function by removing empty capsules. © 2013 John Wiley & Sons A/S.

  16. Synthesis of selectively 13C-labelled benzoic acid for nuclear magnetic resonance spectroscopic measurement of glycine conjugation activity

    International Nuclear Information System (INIS)

    Akira, Kazuki; Hasegawa, Hiroshi; Baba, Shigeo

    1995-01-01

    The synthesis of [4- 13 C]benzoic acid (BA) labelled in a single protonated carbon, for use as a probe to measure glycine conjugation activity by nuclear magnetic resonance (NMR) spectroscopy, has been reported. The labelled compound was prepared by a seven-step synthetic scheme on a relatively small scale using [2- 13 C] acetone as the source of label in overall yield of 16%. The usefulness of [4- 13 C]BA was demonstrated by the NMR spectroscopic monitoring of urinary excretion of [4- 13 C]hippuric acid in the rat administered with the labelled BA. (Author)

  17. The effect of cryoprotection on the use of PLGA encapsulated iron oxide nanoparticles for magnetic cell labeling

    International Nuclear Information System (INIS)

    Tang, Kevin S; Shapiro, Erik M; Hashmi, Sarah M

    2013-01-01

    Magnetic PLGA nanoparticles are a significant advancement in the quest to translate MRI-based cell tracking to the clinic. The benefits of these types of particles are that they encapsulate large amounts of iron oxide nanocrystals within an FDA-approved polymer matrix, combining the best aspects of inert micron-sized iron oxide particles, or MPIOs, and biodegradable small particles of iron oxide, or SPIOs. Practically, PLGA nanoparticle fabrication and storage requires some form of cryoprotectant to both protect the particle during freeze drying and to promote resuspension. While this is a commonly employed procedure in the fabrication of drug loaded PLGA nanoparticles, it has yet to be investigated for magnetic particles and what effect this might have on internalization of magnetic particles. As such, in this study, magnetic PLGA nanoparticles were fabricated with various concentrations of two common cryoprotectants, dextrose and sucrose, and analyzed for their ability to magnetically label cells. It was found that cryoprotection with either sugar significantly enhanced the ability to resuspend nanoparticles without aggregation. Magnetic cell labeling was impacted by sugar concentration, with higher sugar concentrations used during freeze drying more significantly reducing magnetic cell labeling than lower concentrations. These studies suggest that cryoprotection with 1% dextrose is an optimal compromise that preserves monodispersity following resuspension and high magnetic cell labeling. (paper)

  18. Vitality of pancreatic islets labeled for magnetic resonance imaging with iron particles.

    Science.gov (United States)

    Berkova, Z; Kriz, J; Girman, P; Zacharovova, K; Koblas, T; Dovolilova, E; Saudek, F

    2005-10-01

    We previously described an in vivo method for pancreatic islet visualization using magnetic resonance imaging with the aid of superparamagnetic nanoparticles of iron oxide (Resovist) or by magnetic beads precoated with antibodies (Dynabeads). The aim of this study was to investigate the in vitro effect of islet labeling on their quality. Isolated rat islets were cultivated for 48 hours with a contrast agent or, in the case of magnetic antibody-coated beads, for only 2 hours. The ability to secrete insulin was tested by a static insulin release assay and the results were expressed as a stimulation index. Staining with propidium iodide and acridine orange was performed to determine the ratio of live to dead cells. Stimulation indices in the Resovist islets (n = 23) vs controls (n = 14) were 15.3 and 15.0, respectively, and in the Dynabeads islets (n = 15) vs controls (n = 12) 21.3 and 19.9, respectively. The vitality of the Resovist islets vs controls determined by live/dead cells ratio was 90.8% and 91.1%, respectively (n = 20), and in the Dynabeads islets vs controls was 89.4% and 91.8%, respectively (n = 11). Islet labeling with the contrast agent as well as with specific antibodies with iron beads did not change the vitality and insulin-secreting capacity assessed in vitro (P > .05). Magnetic resonance using iron nanoparticles represents the only method for in-vivo visualization of transplanted islets so far. Our data represent an important contribution for its clinical use.

  19. In vivo MR imaging of nanometer magnetically labeled bone marrow stromal cells transplanted via portal vein in rat liver

    International Nuclear Information System (INIS)

    Wang Ping; Wang Jianhua; Yan Zhiping; Hu Meiyu; Xu Pengju; Zhou Meiling; Ya Fuhua; Fan Sheung-tat; Luk John-m

    2006-01-01

    Objective: To evaluate in vivo magnetic resonance imaging with a conventional 1.5-T system for tracking of intra-portal vein transplantation nanometer magnetically labeled BMSCs in rat liver. Methods: BMSCs were isolated from 5 SD rats bone marrow with the density gradient centrifugation method. Then BMSCs were labeled with nanometer superpara-magnetic iron oxide and transfection agent. Cell labeling efficiency was assessed with determination of the percentage of Peris Prussian blue stain. Then BMSCs transplanted into normal rats' livers via portal vein. The receipts were divided into 5 groups ,including sham control,2 h ,3 d,7 d and 2 w after transplantation. Follow-up serial T 1 WI,T 2 WI and T 2 * -weighted gradient- echo MR imaging were performed at 1.5 T MRI system. MR imaging findings were compared with histology. Results: Cell labeling efficiency was more than 95% by Perls Prussian blue stain. After transplantation of labeled BMSCs via portal vein, liver's had diffuse granular signal intensity appearance in T 2 * WI MRI. Cells were detected for up to 2 w in receipts' liver's. At histologic analysis, signal intensity loss correlated with iron-loaded cells. Conclusion: MR imaging could aid in monitoring of magnetically labeled BMSCs administered via portal vein in vivo. (authors)

  20. Study of internalization and viability of multimodal nanoparticles for labeling of human umbilical cord mesenchymal stem cells

    International Nuclear Information System (INIS)

    Miyaki, Liza Aya Mabuchi; Sibov, Tatiana Tais; Pavon, Lorena Favaro; Mamani, Javier Bustamante; Gamarra, Lionel Fernel

    2012-01-01

    Objective: To analyze multimodal magnetic nanoparticles-Rhodamine B in culture media for cell labeling, and to establish a study of multimodal magnetic nanoparticles-Rhodamine B detection at labeled cells evaluating they viability at concentrations of 10 μg Fe/mL and 100μg Fe/mL. Methods: We performed the analysis of stability of multimodal magnetic nanoparticles-Rhodamine B in different culture media; the mesenchymal stem cells labeling with multimodal magnetic nanoparticles-Rhodamine B; the intracellular detection of multimodal magnetic nanoparticles-Rhodamine B in mesenchymal stem cells, and assessment of the viability of labeled cells by kinetic proliferation. Results: The stability analysis showed that multimodal magnetic nanoparticles-Rhodamine B had good stability in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium. The mesenchymal stem cell with multimodal magnetic nanoparticles-Rhodamine B described location of intracellular nanoparticles, which were shown as blue granules co-localized in fluorescent clusters, thus characterizing magnetic and fluorescent properties of multimodal magnetic nanoparticles Rhodamine B. Conclusion: The stability of multimodal magnetic nanoparticles-Rhodamine B found in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium assured intracellular mesenchymal stem cells labeling. This cell labeling did not affect viability of labeled mesenchymal stem cells since they continued to proliferate for five days. (author)

  1. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    International Nuclear Information System (INIS)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso

    2005-01-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  2. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso [Hopital Erasme, Universite Libre de Bruxelles, Department of Radiology, Division of Magnetic Resonance, Brussels (Belgium)

    2005-10-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  3. Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells

    International Nuclear Information System (INIS)

    Akca, Ozlet; Unak, Perihan; Medine, E. Ylker; Sakarya, Serhan; Ozdemir, Caglar; Timur, Suna

    2011-01-01

    Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

  4. Evaluation of In-Situ Magnetic Signals from Iron Oxide Nanoparticle-Labeled PC12 Cells by Atomic Force Microscopy.

    Science.gov (United States)

    Wang, Lijun; Min, Yue; Wang, Zhigang; Riggio, Cristina; Calatayud, M Pilar; Pinkernelle, Josephine; Raffa, Vittoria; Goya, Gerardo F; Keilhoff, Gerburg; Cuschieri, Alfred

    2015-03-01

    The magnetic signals from magnetite nanoparticle-labeled PC12 cells were assessed by magnetic force microscopy by deploying a localized external magnetic field to magnetize the nanoparticles and the magnetic tip simultaneously so that the interaction between the tip and PC12 cell-associated Fe3O4 nanoparticles could be detected at lift heights (the distance between the tip and the sample) larger than 100 nm. The use of large lift heights during the raster scanning of the probe eliminates the non-magnetic interference from the complex and rugged cell surface and yet maintains the sufficient sensitivity for magnetic detection. The magnetic signals of the cell-bound nanoparticles were semi-quantified by analyzing cell surface roughness upon three-dimensional reconstruction generated by the phase shift of the cantilever oscillation. The obtained data can be used for the evaluation of the overall cellular magnetization as well as the maximum magnetic forces from magnetic nanoparticle-labeled cells which is crucial for the biomedical application of these nanomaterials.

  5. Noninvasive measurements of regional cerebral perfusion in preterm and term neonates by magnetic resonance arterial spin labeling

    DEFF Research Database (Denmark)

    Miranda Gimenez-Ricco, Maria Jo; Olofsson, K; Sidaros, Karam

    2006-01-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term-born neon......Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term...

  6. Asynchronous Magnetic Bead Rotation (AMBR Microviscometer for Label-Free DNA Analysis

    Directory of Open Access Journals (Sweden)

    Yunzi Li

    2014-03-01

    Full Text Available We have developed a label-free viscosity-based DNA detection system, using paramagnetic beads as an asynchronous magnetic bead rotation (AMBR microviscometer. We have demonstrated experimentally that the bead rotation period is linearly proportional to the viscosity of a DNA solution surrounding the paramagnetic bead, as expected theoretically. Simple optical measurement of asynchronous microbead motion determines solution viscosity precisely in microscale volumes, thus allowing an estimate of DNA concentration or average fragment length. The response of the AMBR microviscometer yields reproducible measurement of DNA solutions, enzymatic digestion reactions, and PCR systems at template concentrations across a 5000-fold range. The results demonstrate the feasibility of viscosity-based DNA detection using AMBR in microscale aqueous volumes.

  7. Magnetic bead purification of labeled DNA fragments forhigh-throughput capillary electrophoresis sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Elkin, Christopher; Kapur, Hitesh; Smith, Troy; Humphries, David; Pollard, Martin; Hammon, Nancy; Hawkins, Trevor

    2001-09-15

    We have developed an automated purification method for terminator sequencing products based on a magnetic bead technology. This 384-well protocol generates labeled DNA fragments that are essentially free of contaminates for less than $0.005 per reaction. In comparison to laborious ethanol precipitation protocols, this method increases the phred20 read length by forty bases with various DNA templates such as PCR fragments, Plasmids, Cosmids and RCA products. Our method eliminates centrifugation and is compatible with both the MegaBACE 1000 and ABIPrism 3700 capillary instruments. As of September 2001, this method has produced over 1.6 million samples with 93 percent averaging 620 phred20 bases as part of Joint Genome Institutes Production Process.

  8. Synthesis and Characterization of a Gd-DOTA-D-Permeation Peptide for Magnetic Resonance Relaxation Enhancement of Intracellular Targets

    Directory of Open Access Journals (Sweden)

    Andrew M. Prantner

    2003-10-01

    Full Text Available Many MR contrast agents have been developed and proven effective for extracellular nontargeted applications, but exploitation of intracellular MR contrast agents has been elusive due to the permeability barrier of the plasma membrane. Peptide transduction domains can circumvent this permeability barrier and deliver cargo molecules to the cell interior. Based upon enhanced cellular uptake of permeation peptides with D-amino acid residues, an all-D Tat basic domain peptide was conjugated to DOTA and chelated to gadolinium. Gd-DOTA-D-Tat peptide in serum at room temperature showed a relaxivity of 7.94 ± 0.11 mM−1 sec−1 at 4.7 T. The peptide complex displayed no significant binding to serum proteins, was efficiently internalized by human Jurkat leukemia cells resulting in intracellular T1 relaxation enhancement, and in preliminary T1-weighted MRI experiments, significantly enhanced liver, kidney, and mesenteric signals.

  9. Fluorescent magnetic nanoparticles for cell labeling: flux synthesis of manganite particles and novel functionalization of silica shell

    Czech Academy of Sciences Publication Activity Database

    Kačenka, Michal; Kaman, Ondřej; Kikerlová, S.; Pavlů, B.; Jirák, Zdeněk; Jirák, D.; Herynek, Vít; Černý, J.; Chaput, F.; Laurent, S.; Lukeš, I.

    2015-01-01

    Roč. 47, Jun (2015), s. 97-106 ISSN 0021-9797 R&D Projects: GA ČR(CZ) GAP108/11/0807; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378271 ; RVO:68378041 Keywords : manganites * magnetic nanoparticles * molten salt synthesis * silica coating * dual probes * MRI * cell labeling Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.782, year: 2015

  10. Human Aortic Endothelial Cell Labeling with Positive Contrast Gadolinium Oxide Nanoparticles for Cellular Magnetic Resonance Imaging at 7 Tesla

    Directory of Open Access Journals (Sweden)

    Yasir Loai

    2012-03-01

    Full Text Available Positive T1 contrast using gadolinium (Gd contrast agents can potentially improve detection of labeled cells on magnetic resonance imaging (MRI. Recently, gadolinium oxide (Gd2O3 nanoparticles have shown promise as a sensitive T1 agent for cell labeling at clinical field strengths compared to conventional Gd chelates. The objective of this study was to investigate Gado CELLTrack, a commercially available Gd2O3 nanoparticle, for cell labeling and MRI at 7 T. Relaxivity measurements yielded r1 = 4.7 s−1 mM−1 and r2/r1 = 6.2. Human aortic endothelial cells were labeled with Gd2O3 at various concentrations and underwent MRI from 1 to 7 days postlabeling. The magnetic resonance relaxation times T1 and T2 of labeled cell pellets were measured. Cellular contrast agent uptake was quantified by inductively coupled plasma–atomic emission spectroscopy, which showed very high uptake compared to conventional Gd compounds. MRI demonstrated significant positive T1 contrast and stable labeling on cells. Enhancement was optimal at low Gd concentrations, attained in the 0.02 to 0.1 mM incubation concentration range (corresponding cell uptake was 7.26 to 34.1 pg Gd/cell. Cell viability and proliferation were unaffected at the concentrations tested and up to at least 3 days postlabeling. Gd2O3 is a promising sensitive and stable positive contrast agent for cellular MRI at 7 T.

  11. The synthesis, magnetic purification and evaluation of 99mTc-labeled microbubbles

    International Nuclear Information System (INIS)

    Lazarova, Neva; Causey, Patrick W.; Lemon, Jennifer A.; Czorny, Shannon K.; Forbes, John R.; Zlitni, Aimen; Genady, Afaf; Foster, F. Stuart; Valliant, John F.

    2011-01-01

    Introduction: Ultrasound (US) contrast agents based on microbubbles (MBs) are being investigated as platforms for drug and gene delivery. A methodology for determining the distribution and fate of modified MBs quantitatively in vivo can be achieved by tagging MBs directly with 99m Tc. This creates the opportunity to employ dual-modality imaging using both US and small animal SPECT along with quantitative ex vivo tissue counting to evaluate novel MB constructs. Methods: A 99m Tc-labeled biotin derivative ( 99m TcL1) was prepared and incubated with streptavidin-coated MBs. The 99m Tc-labeled bubbles were isolated using a streptavidin-coated magnetic-bead purification strategy that did not disrupt the MBs. A small animal scintigraphic/CT imaging study as well as a quantitative biodistribution study was completed using 99m TcL1 and 99m Tc-labeled bubbles in healthy C57Bl-6 mice. Results: The imaging and biodistribution data showed rapid accumulation and retention of 99m Tc-MBs in the liver (68.2±6.6 %ID/g at 4 min; 93.3±3.2 %ID/g at 60 min) and spleen (214.2±19.7 %ID/g at 4 min; 213.4±19.7 %ID/g at 60 min). In contrast, 99m TcL1 accumulated in multiple organs including the small intestine (22.5±3.6 %ID/g at 4 min; 83.4±5.9 %ID/g at 60 min) and bladder (184.0±88.1 %ID/g at 4 min; 24.2±17.7 %ID/g at 60 min). Conclusion: A convenient means to radiolabel and purify MBs was developed and the distribution of the labeled products determined. The result is a platform which can be used to assess the pharmacokinetics and fate of novel MB constructs both regionally using US and throughout the entire subject in a quantitative manner by employing small animal SPECT and tissue counting.

  12. Arterial spin labeling blood flow magnetic resonance imaging for evaluation of renal injury.

    Science.gov (United States)

    Liu, Yupin P; Song, Rui; Liang, Chang hong; Chen, Xin; Liu, Bo

    2012-08-15

    A multitude of evidence suggests that iodinated contrast material causes nephrotoxicity; however, there have been no previous studies that use arterial spin labeling (ASL) blood flow functional magnetic resonance imaging (fMRI) to investigate the alterations in effective renal plasma flow between normointensive and hypertensive rats following injection of contrast media. We hypothesized that FAIR-SSFSE arterial spin labeling MRI may enable noninvasive and quantitative assessment of regional renal blood flow abnormalities and correlate with disease severity as assessed by histological methods. Renal blood flow (RBF) values of the cortex and medulla of rat kidneys were obtained from ASL images postprocessed at ADW4.3 workstation 0.3, 24, 48, and 72 h before and after injection of iodinated contrast media (6 ml/kg). The H&E method for morphometric measurements was used to confirm the MRI findings. The RBF values of the outer medulla were lower than those of the cortex and the inner medulla as reported previously. Iodinated contrast media treatment resulted in decreases in RBF in the outer medulla and cortex in spontaneously hypertensive rats (SHR), but only in the outer medulla in normotensive rats. The iodinated contrast agent significantly decreased the RBF value in the outer medulla and the cortex in SHR compared with normotensive rats after injection of the iodinated contrast media. Histological observations of kidney morphology were also consistent with ASL perfusion changes. These results demonstrate that the RBF value can reflect changes of renal perfusion in the cortex and medulla. ASL-MRI is a feasible and accurate method for evaluating nephrotoxic drugs-induced kidney damage.

  13. Human induced pluripotent stem cells labeled with fluorescent magnetic nanoparticles for targeted imaging and hyperthermia therapy for gastric cancer

    International Nuclear Information System (INIS)

    Li, Chao; Ruan, Jing; Yang, Meng; Pan, Fei; Gao, Guo; Qu, Su; Shen, You-Lan; Dang, Yong-Jun; Wang, Kan; Jin, Wei-Lin; Cui, Da-Xiang

    2015-01-01

    Human induced pluripotent stem (iPS) cells exhibit great potential for generating functional human cells for medical therapies. In this paper, we report for use of human iPS cells labeled with fluorescent magnetic nanoparticles (FMNPs) for targeted imaging and synergistic therapy of gastric cancer cells in vivo. Human iPS cells were prepared and cultured for 72 h. The culture medium was collected, and then was co-incubated with MGC803 cells. Cell viability was analyzed by the MTT method. FMNP-labeled human iPS cells were prepared and injected into gastric cancer-bearing nude mice. The mouse model was observed using a small-animal imaging system. The nude mice were irradiated under an external alternating magnetic field and evaluated using an infrared thermal mapping instrument. Tumor sizes were measured weekly. iPS cells and the collected culture medium inhibited the growth of MGC803 cells. FMNP-labeled human iPS cells targeted and imaged gastric cancer cells in vivo, as well as inhibited cancer growth in vivo through the external magnetic field. FMNP-labeled human iPS cells exhibit considerable potential in applications such as targeted dual-mode imaging and synergistic therapy for early gastric cancer

  14. Phosphorus nuclear magnetic resonance studies of the energetic state and of the intracellular pH of the isolated rat heart in the course of ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, A [Grenoble-1 Univ., 38 (France); Martin, J; de Leiris, J [CEA Centre d' Etudes Nucleaires de Grenoble, 38 (France). Lab. de Chimie Organique Physique

    1981-01-01

    Continuous measurements of high energy phosphate compounds and intracellular pH in perfused, beating rat hearts, were performed by /sup 31/P nuclear magnetic resonance (NMR). Hearts were placed in a 15 mm NMR tube and perfused at 28/sup 0/C by conventional methods with a phosphate-free solution. Phosphorus NMR spectra were recorded at 101,3 MHz in a Brucker WP 250 spectrometer. Global mild ischemia was achieved by reducing the coronary flow to 1/10 of its initial value. Changes in creatine phosphate (CP) and inorganic phosphate (Pi) levels and intracellular pH (pHi) were monitored in the course of a 50 min ischemia and during the post-ischemic phase. When the breakdown of CP was less than 30%, the decrease in pHi was about 0.1 to 0.2 pH unit; for a greater CP decrease, the fall in pHi was about 1 pH unit.

  15. Study of internalization and viability of multimodal nanoparticles for labeling of human umbilical cord mesenchymal stem cells; Estudo de internalizacao e viabilidade de nanoparticulas multimodal para marcacao de celulas-tronco mesenquimais de cordao umbilical humano

    Energy Technology Data Exchange (ETDEWEB)

    Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Sibov, Tatiana Tais; Pavon, Lorena Favaro; Mamani, Javier Bustamante; Gamarra, Lionel Fernel, E-mail: tatianats@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil)

    2012-04-15

    Objective: To analyze multimodal magnetic nanoparticles-Rhodamine B in culture media for cell labeling, and to establish a study of multimodal magnetic nanoparticles-Rhodamine B detection at labeled cells evaluating they viability at concentrations of 10 {mu}g Fe/mL and 100{mu}g Fe/mL. Methods: We performed the analysis of stability of multimodal magnetic nanoparticles-Rhodamine B in different culture media; the mesenchymal stem cells labeling with multimodal magnetic nanoparticles-Rhodamine B; the intracellular detection of multimodal magnetic nanoparticles-Rhodamine B in mesenchymal stem cells, and assessment of the viability of labeled cells by kinetic proliferation. Results: The stability analysis showed that multimodal magnetic nanoparticles-Rhodamine B had good stability in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium. The mesenchymal stem cell with multimodal magnetic nanoparticles-Rhodamine B described location of intracellular nanoparticles, which were shown as blue granules co-localized in fluorescent clusters, thus characterizing magnetic and fluorescent properties of multimodal magnetic nanoparticles Rhodamine B. Conclusion: The stability of multimodal magnetic nanoparticles-Rhodamine B found in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium assured intracellular mesenchymal stem cells labeling. This cell labeling did not affect viability of labeled mesenchymal stem cells since they continued to proliferate for five days. (author)

  16. Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

    Energy Technology Data Exchange (ETDEWEB)

    Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E. [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)

    2014-06-15

    An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.

  17. Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

    Science.gov (United States)

    Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.

    2014-06-01

    An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label.

  18. Integrable perturbed magnetic fields in toroidal geometry: An exact analytical flux surface label for large aspect ratio

    International Nuclear Information System (INIS)

    Kallinikos, N.; Isliker, H.; Vlahos, L.; Meletlidou, E.

    2014-01-01

    An analytical description of magnetic islands is presented for the typical case of a single perturbation mode introduced to tokamak plasma equilibrium in the large aspect ratio approximation. Following the Hamiltonian structure directly in terms of toroidal coordinates, the well known integrability of this system is exploited, laying out a precise and practical way for determining the island topology features, as required in various applications, through an analytical and exact flux surface label

  19. Behaviour of adipose-derived canine mesenchymal stem cells after superparamagnetic iron oxide nanoparticles labelling for magnetic resonance imaging

    OpenAIRE

    Kolecka, Malgorzata Anna; Arnhold, Stefan; Schmidt, Martin; Reich, Christine; Kramer, Martin; Failing, Klaus; von P?ckler, Kerstin

    2017-01-01

    Background: Therapy with mesenchymal stem cells (MSCs) has been reported to provide beneficial effects in the treatment of neurological and orthopaedic disorders in dogs. The exact mechanism of action is poorly understood. Magnetic resonance imaging (MRI) gives the opportunity to observe MSCs after clinical administration. To visualise MSCs with the help of MRI, labelling with an MRI contrast agent is necessary. However, it must be clarified whether there is any negative influence on cell fun...

  20. Optimized labeling of bone marrow mesenchymal cells with superparamagnetic iron oxide nanoparticles and in vivo visualization by magnetic resonance imaging

    Science.gov (United States)

    2011-01-01

    Background Stem cell therapy has emerged as a promising addition to traditional treatments for a number of diseases. However, harnessing the therapeutic potential of stem cells requires an understanding of their fate in vivo. Non-invasive cell tracking can provide knowledge about mechanisms responsible for functional improvement of host tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label and visualize various cell types with magnetic resonance imaging (MRI). In this study we performed experiments designed to investigate the biological properties, including proliferation, viability and differentiation capacity of mesenchymal cells (MSCs) labeled with clinically approved SPIONs. Results Rat and mouse MSCs were isolated, cultured, and incubated with dextran-covered SPIONs (ferumoxide) alone or with poly-L-lysine (PLL) or protamine chlorhydrate for 4 or 24 hrs. Labeling efficiency was evaluated by dextran immunocytochemistry and MRI. Cell proliferation and viability were evaluated in vitro with Ki67 immunocytochemistry and live/dead assays. Ferumoxide-labeled MSCs could be induced to differentiate to adipocytes, osteocytes and chondrocytes. We analyzed ferumoxide retention in MSCs with or without mitomycin C pretreatment. Approximately 95% MSCs were labeled when incubated with ferumoxide for 4 or 24 hrs in the presence of PLL or protamine, whereas labeling of MSCs incubated with ferumoxide alone was poor. Proliferative capacity was maintained in MSCs incubated with ferumoxide and PLL for 4 hrs, however, after 24 hrs it was reduced. MSCs incubated with ferumoxide and protamine were efficiently visualized by MRI; they maintained proliferation and viability for up to 7 days and remained competent to differentiate. After 21 days MSCs pretreated with mitomycin C still showed a large number of ferumoxide-labeled cells. Conclusions The efficient and long lasting uptake and retention of SPIONs by MSCs using a protocol employing ferumoxide and

  1. Labeling transplanted mice islet with polyvinylpyrrolidone coated superparamagnetic iron oxide nanoparticles for in vivo detection by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huang Hai; Xie Qiuping; Kang Muxing; Zhang Bo; Wu Yulian [Department of Surgery, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Zhang Hui; Chen Jin; Zhai Chuanxin; Yang Deren [State Key Lab of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Jiang Biao, E-mail: wuyulian@medmail.com.c, E-mail: yulianwu2003@yahoo.c [Department of Radiology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2009-09-09

    Superparamagnetic iron oxide nanoparticles (SPIO) are emerging as a novel probe for noninvasive cell tracking with magnetic resonance imaging (MRI) and have potential wide usage in medical research. In this study, we have developed a method using high-temperature hydrolysis of chelate metal alkoxide complexes to synthesize polyvinylpyrrolidone coated iron oxide nanoparticles (PVP-SPIO), as a biocompatible magnetic agent that can efficiently label mice islet {beta}-cells. The size, crystal structure and magnetic properties of the as-synthesized nanoparticles have been characterized. The newly synthesized PVP-SPIO with high stability, crystallinity and saturation magnetization can be efficiently internalized into {beta}-cells, without affecting viability and function. The imaging of 100 PVP-SPIO-labeled mice islets in the syngeneic renal subcapsular model of transplantation under a clinical 3.0 T MR imager showed high spatial resolution in vivo. These results indicated the great potential application of the PVP-SPIO as an MRI contrast agent for monitoring transplanted islet grafts in the clinical management of diabetes in the near future.

  2. Labeling transplanted mice islet with polyvinylpyrrolidone coated superparamagnetic iron oxide nanoparticles for in vivo detection by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Huang Hai; Xie Qiuping; Kang Muxing; Zhang Bo; Wu Yulian; Zhang Hui; Chen Jin; Zhai Chuanxin; Yang Deren; Jiang Biao

    2009-01-01

    Superparamagnetic iron oxide nanoparticles (SPIO) are emerging as a novel probe for noninvasive cell tracking with magnetic resonance imaging (MRI) and have potential wide usage in medical research. In this study, we have developed a method using high-temperature hydrolysis of chelate metal alkoxide complexes to synthesize polyvinylpyrrolidone coated iron oxide nanoparticles (PVP-SPIO), as a biocompatible magnetic agent that can efficiently label mice islet β-cells. The size, crystal structure and magnetic properties of the as-synthesized nanoparticles have been characterized. The newly synthesized PVP-SPIO with high stability, crystallinity and saturation magnetization can be efficiently internalized into β-cells, without affecting viability and function. The imaging of 100 PVP-SPIO-labeled mice islets in the syngeneic renal subcapsular model of transplantation under a clinical 3.0 T MR imager showed high spatial resolution in vivo. These results indicated the great potential application of the PVP-SPIO as an MRI contrast agent for monitoring transplanted islet grafts in the clinical management of diabetes in the near future.

  3. Multifunctional pH-sensitive magnetic nanoparticles for simultaneous imaging, sensing and targeted intracellular anticancer drug delivery

    International Nuclear Information System (INIS)

    Banerjee, Shashwat S; Chen, D-H

    2008-01-01

    A novel multifunctional magnetic nanocarrier was fabricated for synchronous cancer therapy and sensing. The nanocarrier, programed to display a response to environmental stimuli (pH value), was synthesized by coupling doxorubicin (DOX) to adipic dihydrazide-grafted gum arabic modified magnetic nanoparticles (ADH-GAMNP) via the hydrolytically degradable pH-sensitive hydrazone bond. The resultant nanocarrier, DOX-ADH-GAMNP, had a mean diameter of 13.8 nm and the amount of DOX coupled was about 6.52 mg g -1 . Also, it exhibited pH triggered release of DOX in an acidic environment (pH 5.0) but was relatively stable at physiological pH (pH 7.4). Furthermore, both GAMNP and DOX were found to possess fluorescence properties when excited in the near-infrared region due to the two-photon absorption mechanism. The coupling of DOX to GAMNP resulted in a reversible self-quenching of fluorescence through the fluorescence resonant energy transfer (FRET) between the donor GAMNP and acceptor DOX. The release of DOX from DOX-ADH-GAMNP when exposed to acidic media indicated the recovery of fluorescence from both GAMNP and DOX. The change in the fluorescence intensity of DOX-ADH-GAMNP on the release of DOX can act as a potential sensor to sense the delivery of the drug. The analysis of zeta potential and plasmon absorbance in different pH conditions also confirmed the pH sensitivity of the product. This multifunctional nanocarrier is a significant breakthrough in developing a drug delivery vehicle that combines drug targeting as well as sensing and therapy at the same time.

  4. Magnetic cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of hepatocyte transplantation.

    Directory of Open Access Journals (Sweden)

    Dwayne R Roach

    Full Text Available Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP and stem cell-derived hepatocytes (PICM-19FF. The magnetic particle is a micron-sized iron oxide particle (MPIO that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility.

  5. Architecture and dynamics of isotopically labelled macromolecules by nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Matwiyoff, N.A.

    1979-01-01

    The use of 13 C is considered using NMR spectra of cell suspensions. Biochemical reaction kinetics are still unclear in the study of environmental and structural perturbations of amino acids and peptides; thus needs still exist for this labelling technique

  6. Perfusion magnetic resonance imaging with continuous arterial spin labeling: methods and clinical applications in the central nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Detre, John A. E-mail: detre@mail.med.upenn.edu; Alsop, David C

    1999-05-01

    Several methods are now available for measuring cerebral perfusion and related hemodynamic parameters using magnetic resonance imaging (MRI). One class of techniques utilizes electromagnetically labeled arterial blood water as a noninvasive diffusible tracer for blood flow measurements. The electromagnetically labeled tracer has a decay rate of T1, which is sufficiently long to allow perfusion of the tissue and microvasculature to be detected. Alternatively, electromagnetic arterial spin labeling (ASL) may be used to obtain qualitative perfusion contrast for detecting changes in blood flow, similar to the use of susceptibility contrast in blood oxygenation level dependent functional MRI (BOLD fMRI) to detect functional activation in the brain. The ability to obtain blood flow maps using a non-invasive and widely available modality such as MRI should greatly enhance the utility of blood flow measurement as a means of gaining further insight into the broad range of hemodynamically related physiology and pathophysiology. This article describes the biophysical considerations pertaining to the generation of quantitative blood flow maps using a particular form of ASL in which arterial blood water is continuously labeled, termed continuous arterial spin labeling (CASL). Technical advances permit multislice perfusion imaging using CASL with reduced sensitivity to motion and transit time effects. Interpretable cerebral perfusion images can now be reliably obtained in a variety of clinical settings including acute stroke, chronic cerebrovascular disease, degenerative diseases and epilepsy. Over the past several years, the technical and theoretical foundations of CASL perfusion MRI techniques have evolved from feasibility studies into practical usage. Currently existing methodologies are sufficient to make reliable and clinically relevant observations which complement structural assessment using MRI. Future technical improvements should further reduce the acquisition times

  7. Magnetic resonance imaging of mouse islet grafts labeled with novel chitosan-coated superparamagnetic iron oxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Jyuhn-Huarng Juang

    Full Text Available To better understand the fate of islet isografts and allografts, we utilized a magnetic resonance (MR imaging technique to monitor mouse islets labeled with a novel MR contrast agent, chitosan-coated superparamagnetic iron oxide (CSPIO nanoparticles.After being incubated with and without CSPIO (10 µg/ml, C57BL/6 mouse islets were examined under transmission electron microscope (TEM and their insulin secretion was measured. Cytotoxicity was examined in α (αTC1 and β (NIT-1 and βTC cell lines as well as islets. C57BL/6 mice were used as donors and inbred C57BL/6 and Balb/c mice were used as recipients of islet transplantation. Three hundred islets were transplanted under the left kidney capsule of each mouse and then MR was performed in the recipients periodically. At the end of study, the islet graft was removed for histology and TEM studies.After incubation of mouse islets with CSPIO (10 µg/mL, TEM showed CSPIO in endocytotic vesicles of α- and β-cells at 8 h. Incubation with CSPIO did not affect insulin secretion from islets and death rates of αTC1, NIT-1 and βTC cell lines as well as islets. After syngeneic and allogeneic transplantation, grafts of CSPIO-labeled islets were visualized on MR scans as persistent hypointense areas. At 8 weeks after syngeneic transplantation and 31 days after allogeneic transplantation, histology of CSPIO-labeled islet grafts showed colocalized insulin and iron staining in the same areas but the size of allografts decreased with time. TEM with elementary iron mapping demonstrated CSPIO distributed in the cytoplasm of islet cells, which maintained intact ultrastructure.Our results indicate that after syngeneic and allogeneic transplantation, islets labeled with CSPIO nanoparticles can be effectively and safely imaged by MR.

  8. The experimental study on tropism of magnetic labeled bone marrow mesenchymal stem cells for hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Chen Shuangqing; Wang Peijun; Li Minghua; Zhang Wei; Dai gonghua

    2009-01-01

    Objective: To label rat bone marrow mesenchymal stem cells with superparamagnetic iron oxide (SPIO) and to explore the tropism of BMSCs for hepatocellular carcinoma cells after transplantation in vivo. Methods: BMSCs from bone marrow of Sprague-Dawly (SD) rats were cultured isolated and purified. Labeled BMSCs was achieved using Feridex. Twenty-four hepatocellular carcinoma models of SD rats were induced two weeks before transplantation. The models were divided into three groups in random: the labeled BMSCs and unlabeled BMSCs were transplanted respectively into the rat's livers of experimental group (n=12) and control group A (n=6) via spleens, and no transplant was done for control group B (n=6). MR imaging was performed to monitor the transplanted cells after 1,3,7,14 d using 1.5 T MR system. Signal intensity ratio (SI/SI * ) between tumor and hepatic tissue on T 2 * WI were measured and compared by one-factor analysis of variance. After MR imaging, Prussian blue staining was performed. MR imaging findings were compared with histological sections. Results: Prussian blue staining confirmed the labeling efficiency of BMSCs was above 90%. SI/SI * of experimental group before and 1, 3, 7, 14 d after transplantation were 3.18±0.21, 1.98±0.20, 2.38±0.28, 2.70±0.25 and 3.16±0.24 respectively. Following transplantation of BMSCs, signal intensity decrease was found in hepatocellular carcinoma of experimental group (F=56.65, P 2 * WI (P>0.05). A large number of Prussian blue staining positive cells were found in hepatocellular carcinoma in experimental group. Histological section with Prussian blue staining had a good correlation with the signal intensity changes on MR images at different time. Conclusion: BMSCs display significant tropism to hepatocellular carcinoma and may be an ideal gene therapy vehicle against hepatocellular carcinoma. (authors)

  9. Intermittent theta-burst transcranial magnetic stimulation for autism spectrum disorder: an open-label pilot study

    Directory of Open Access Journals (Sweden)

    Caio Abujadi

    2017-12-01

    Full Text Available Objective: Theta-burst stimulation (TBS modulates synaptic plasticity more efficiently than standard repetitive transcranial magnetic stimulation delivery and may be a promising modality for neuropsychiatric disorders such as autism spectrum disorder (ASD. At present there are few effective interventions for prefrontal cortex dysfunction in ASD. We report on an open-label, pilot study of intermittent TBS (iTBS to target executive function deficits and restricted, repetitive behaviors in male children and adolescents with ASD. Methods: Ten right-handed, male participants, aged 9-17 years with ASD were enrolled in an open-label trial of iTBS treatment. Fifteen sessions of neuronavigated iTBS at 100% motor threshold targeting the right dorsolateral prefrontal cortex were delivered over 3 weeks. Results: Parent report scores on the Repetitive Behavior Scale Revised and the Yale-Brown Obsessive Compulsive Scale demonstrated improvements with iTBS treatment. Participants demonstrated improvements in perseverative errors on the Wisconsin Card Sorting Test and total time for the Stroop test. The iTBS treatments were well tolerated with no serious adverse effects. Conclusion: These preliminary results suggest that further controlled interventional studies of iTBS for ASD are warranted.

  10. Intermittent theta-burst transcranial magnetic stimulation for autism spectrum disorder: an open-label pilot study.

    Science.gov (United States)

    Abujadi, Caio; Croarkin, Paul E; Bellini, Bianca B; Brentani, Helena; Marcolin, Marco A

    2017-12-11

    Theta-burst stimulation (TBS) modulates synaptic plasticity more efficiently than standard repetitive transcranial magnetic stimulation delivery and may be a promising modality for neuropsychiatric disorders such as autism spectrum disorder (ASD). At present there are few effective interventions for prefrontal cortex dysfunction in ASD. We report on an open-label, pilot study of intermittent TBS (iTBS) to target executive function deficits and restricted, repetitive behaviors in male children and adolescents with ASD. Ten right-handed, male participants, aged 9-17 years with ASD were enrolled in an open-label trial of iTBS treatment. Fifteen sessions of neuronavigated iTBS at 100% motor threshold targeting the right dorsolateral prefrontal cortex were delivered over 3 weeks. Parent report scores on the Repetitive Behavior Scale Revised and the Yale-Brown Obsessive Compulsive Scale demonstrated improvements with iTBS treatment. Participants demonstrated improvements in perseverative errors on the Wisconsin Card Sorting Test and total time for the Stroop test. The iTBS treatments were well tolerated with no serious adverse effects. These preliminary results suggest that further controlled interventional studies of iTBS for ASD are warranted.

  11. Magnetic Gold Nanoparticle-Labeled Heparanase Monoclonal Antibody and its Subsequent Application for Tumor Magnetic Resonance Imaging

    Science.gov (United States)

    Li, Ning; Jie, Meng-Meng; Yang, Min; Tang, Li; Chen, Si-Yuan; Sun, Xue-Mei; Tang, Bo; Yang, Shi-Ming

    2018-04-01

    Heparanase (HPA) is ubiquitously expressed in various metastatic malignant tumors; previous studies have demonstrated that HPA was a potential tumor-associated antigen (TAA) for tumor immunotherapy. We sought to evaluate the feasibility of HPA as a common TAA for magnetic resonance imaging (MRI) of tumor metastasis and its potential application in tumor molecular imaging. We prepared a targeted probe based on magnetic gold nanoparticles coupled with an anti-HPA antibody for the specific detection of HPA by MRI. The specificity of the targeted probe was validated in vitro by incubation of the probe with various tumor cells, and the probe was able to selectively detect HPA (+) cells. We found the probes displayed significantly reduced signal intensity in several tumor cells, and the signal intensity decreased significantly after the targeted probe was injected in tumor-bearing nude mice. In the study, we demonstrated that the HPA&GoldMag probe had excellent physical and chemical properties and immune activities and could specifically target many tumor cell tissues both in vitro and in vivo. This may provide an experimental base for molecular imaging of tumor highly expressing heparanase using HPA mAbs.

  12. The long-term fate of mesenchymal stem cells labeled with magnetic resonance imaging-visible polymersomes in cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Duan X

    2017-09-01

    Full Text Available Xiaohui Duan,1,* Liejing Lu,1,* Yong Wang,2 Fang Zhang,1 Jiaji Mao,1 Minghui Cao,1 Bingling Lin,1 Xiang Zhang,1 Xintao Shuai,2,3 Jun Shen1 1Department of Radiology, Sun Yat-Sen Memorial Hospital, 2PCFM Lab of Ministry of Education, School of Materials Science and Engineering, 3BME Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Understanding the long-term fate and potential mechanisms of mesenchymal stem cells (MSCs after transplantation is essential for improving functional benefits of stem cell-based stroke treatment. Magnetic resonance imaging (MRI is considered an attractive and clinically translatable tool for longitudinal tracking of stem cells, but certain controversies have arisen in this regard. In this study, we used SPION-loaded cationic polymersomes to label green fluorescent protein (GFP-expressing MSCs to determine whether MRI can accurately reflect survival, long-term fate, and potential mechanisms of MSCs in ischemic stroke therapy. Our results showed that MSCs could improve the functional outcome and reduce the infarct volume of stroke in the brain. In vivo MRI can verify the biodistribution and migration of grafted cells when pre-labeled with SPION-loaded polymersome. The dynamic change of low signal volume on MRI can reflect the tendency of cell survival and apoptosis, but may overestimate long-term survival owing to the presence of iron-laden macrophages around cell graft. Only a small fraction of grafted cells survived up to 8 weeks after transplantation. A minority of these surviving cells were differentiated into astrocytes, but not into neurons. MSCs might exert their therapeutic effect via secreting paracrine factors rather than directing cell replacement through differentiation into neuronal and/or glial phenotypes. Keywords: mesenchymal stem cells, magnetic resonance imaging, superparamagnetic iron oxide

  13. Label-free DNA quantification via a 'pipette, aggregate and blot' (PAB) approach with magnetic silica particles on filter paper.

    Science.gov (United States)

    Li, Jingyi; Liu, Qian; Alsamarri, Hussein; Lounsbury, Jenny A; Haversitick, Doris M; Landers, James P

    2013-03-07

    Reliable measurement of DNA concentration is essential for a broad range of applications in biology and molecular biology, and for many of these, quantifying the nucleic acid content is inextricably linked to obtaining optimal results. In its most simplistic form, quantitative analysis of nucleic acids can be accomplished by UV-Vis absorbance and, in more sophisticated format, by fluorimetry. A recently reported new concept, the 'pinwheel assay', involves a label-free approach for quantifying DNA through aggregation of paramagnetic beads in a rotating magnetic field. Here, we describe a simplified version of that assay adapted for execution using only a pipet and filter paper. The 'pipette, aggregate, and blot' (PAB) approach allows DNA to induce bead aggregation in a pipette tip through exposure to a magnetic field, followed by dispensing (blotting) onto filter paper. The filter paper immortalises the extent of aggregation, and digital images of the immortalized bead conformation, acquired with either a document scanner or a cell phone camera, allows for DNA quantification using a noncomplex algorithm. Human genomic DNA samples extracted from blood are quantified with the PAB approach and the results utilized to define the volume of sample used in a PCR reaction that is sensitive to input mass of template DNA. Integrating the PAB assay with paper-based DNA extraction and detection modalities has the potential to yield 'DNA quant-on-paper' devices that may be useful for point-of-care testing.

  14. Development and experimental basis of local subretinal technique of xenogenic’s injection stem cells labelled by magnetic perticles

    Directory of Open Access Journals (Sweden)

    Yu. A. Belyy

    2014-10-01

    Full Text Available Purpose: is to develop a technique for local subretinal injection of xenogeneic stem cells labeled with magnetic particles and to prove experimentally its effectiveness.Material and methods: We used a line of stem cells HEK-293 GFP,labeled with magnetic particles. The study was made on 84 eyes of 42 chinchilla rabbits 6 months of age, the weight were from 2.5 to 3.5 kg. All right eyes were experimental (42 eyes and all left eyes (42 eyes were the control group. In the experimental group we used original complex of polymer elastic magnetic implant (PEMI with laser probe and fixed it to the sclera, then we made a median vitrectomy and injected HEK-293 GFP under the retina using a specially designed dispenser. In the control group PEMI was not fixed. We examined animals using biomicroscopy, ophthalmoscopy, ultrasound scanning, optical coherence tomography  OCT, computer tomography (CT, morphological study (cryohistological sections in 1, 3, 5, 7, 14 day and 1 month after surgery.Results: According the results of biomicroscopy in observation periods up to 3 days the vascular injection was visualized in the area operation. According the results of ophthalmoscopy and ultrasound scanning in 1 day the local retinal detachment was visualized in the area of local injection of the stem cells, which was not visualized in terms of further observations. CT helped us to confirm the local place of PEMI fixation. The morphological study results showed that cells were located in the subretinal space up to 14 days in the experimental group, and only up 3 days in the control group.Conclusion: The suggested surgical technique enables to control the injection of cells into the subretinal space, reduces the risk of tissue damage and exit cells in the vitreous space. The suggested methodology allows the fixing of the cellular material in the local place of the injection and enables to predict cells`s movement.

  15. Carbon magnetic resonance spectroscopy on carbon-13-labeled uracil in 5S ribonucleic acid

    International Nuclear Information System (INIS)

    Hamill, W.D.; Grant, D.M.; Cooper, R.B.; Harmon, S.A.

    1978-01-01

    The carbon-13 nuclear magnetic resonance spectra of the 13 C-enriched C-4 uridine carbons in 5S ribosomal ribonucleic acid of Salmonella typhimurium, strain JL-1055, was obtained. The most striking feature of the 5S RNA spectrum was the large number of well-resolved lines in the uridine band covering a chemical shift range of approximately 3.6 ppM. This data was used to obtain information on the secondary structure. The number of uridines involved in secondary interactions is estimated to be at least 75% and may be as high as 95%

  16. The use of oligoperoxide-coated magnetic nanoparticles to label stem cells

    Czech Academy of Sciences Publication Activity Database

    Šponarová, Daniela; Horák, Daniel; Trchová, Miroslava; Jendelová, Pavla; Herynek, V.; Mitina, N.; Zaichenko, A.; Stoika, R.; Lesný, Petr; Syková, Eva

    2011-01-01

    Roč. 7, č. 3 (2011), s. 384-394 ISSN 1550-7033 R&D Projects: GA ČR GA203/09/1242; GA ČR GAP503/10/0664; GA MŠk 1M0538; GA AV ČR KAN201110651; GA AV ČR(CZ) KAN401220801 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z50390703 Keywords : magnetic * nanoparticles * stem cells Subject RIV: FH - Neurology Impact factor: 4.216, year: 2011

  17. Mechanism of the negative force-frequency relationship in physiologically intact rat ventricular myocardium. Studies by intracellular Ca2+ monitor with iodo-1 and by 31P-nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Morii, Isao; Kihara, Yasuki; Sasayama, Shigetake; Konishi, Takashi; Inubushi, Toshiro.

    1996-01-01

    We studied the subcellular mechanisms of the negative force-frequency relationship in rat myocardium by measuring intracellular Ca 2+ transients by indo-1 fluorometry and intracellular pH (pH i ) and phosphate compounds with 31 P-nuclear magnetic resonance (NMR). The data were compared with those from guinea pig hearts, which show a positive force-frequency relationship. By increasing the pacing rate from 3 Hz to 5 Hz, the peak positive first derivative of left ventricular pressure (LVdP/dt) in rat heart decreased by 10±1% (n=6). In contrast to this negative inotropic response, simultaneously measured peak Ca 2+ transients increased by 6±1%. Guinea pig heart (n=6) showed an increase in peak positive LVdP/dt (33±1%) which was associated with an increase in peak Ca 2+ transients (8±1%). Under equivalent experimental conditions in an NMR spectrometer, this increase in the pacing rate did not affect intracellular levels of phosphate compounds in either rat (n=6) or guinea pig heart (n=6). In contrast, pH i showed a decrease of 0.031±0.006 pH units in rat heart, while no changes were observed in guinea pig heart. These results suggest that in physiological rat myocardium, pH i is susceptible to changes in the stimulus frequency and may affect the Ca 2+ -responsiveness of contractile proteins, which results in the negative force-frequency relationship. (author)

  18. Consequences of the magnetic field, sonic and radiofrequency waves and intense pulsed light on the labeling of blood constituents with technetium-99m

    International Nuclear Information System (INIS)

    Meyer, Patricia Froes; Costa, Iris do Ceu Clara; Brandao-Neto, Jose; Medeiros, Aldo da Cunha; Bonelli, Ludmila

    2007-01-01

    Sources of magnetic field, radiofrequency and audible sonic waves and pulsed light have been used in physiotherapy to treat different disorders. In nuclear medicine, blood constituents(Bl-Co) are labeled with technetium-99m ( 99m Tc) are used. This study evaluated the consequences of magnetic field, radiofrequency and audible sonic waves and intense pulsed light sources on the labeling of Bl-Co with 99m Tc. Blood from Wistar rats was exposed to the cited sources. The labeling of Bl-Co with 99m Tc was performed. Blood not exposed to the physical agents was used(controls). Data showed that the exposure to the different studied sources did not alter significantly (p>0.05) the labeling of Bl-Co. Although the results were obtained with animals, the data suggest that no alteration on examinations performed with Bl-Co labeled with 99m Tc after exposition to the cited agents. The biological consequences associated with these agents would be not capable to interfere with some properties of the Bl-Co. (author)

  19. Consequences of the magnetic field, sonic and radiofrequency waves and intense pulsed light on the labeling of blood constituents with technetium-99m

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Patricia Froes; Costa, Iris do Ceu Clara; Brandao-Neto, Jose; Medeiros, Aldo da Cunha [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Pos-graduacao em Ciencias da Saude; Santos-Filho, Sebastiao David; Adenilson de Souza da Fonseca; Bernardo-Filho, Mario [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Lab. de Radiofarmacia Experimental; Ariel Ronzio, Oscar [Universidad de Buenos Aires (Argentina); Bonelli, Ludmila [Universidade Salgado de Oliveira, Belo Horizonte, MG (Brazil)

    2007-09-15

    Sources of magnetic field, radiofrequency and audible sonic waves and pulsed light have been used in physiotherapy to treat different disorders. In nuclear medicine, blood constituents(Bl-Co) are labeled with technetium-99m ({sup 99m}Tc) are used. This study evaluated the consequences of magnetic field, radiofrequency and audible sonic waves and intense pulsed light sources on the labeling of Bl-Co with {sup 99m}Tc. Blood from Wistar rats was exposed to the cited sources. The labeling of Bl-Co with {sup 99m}Tc was performed. Blood not exposed to the physical agents was used(controls). Data showed that the exposure to the different studied sources did not alter significantly (p>0.05) the labeling of Bl-Co. Although the results were obtained with animals, the data suggest that no alteration on examinations performed with Bl-Co labeled with {sup 99m}Tc after exposition to the cited agents. The biological consequences associated with these agents would be not capable to interfere with some properties of the Bl-Co. (author)

  20. Chemiluminescent labels released from long spacer arm-functionalized magnetic particles: a novel strategy for ultrasensitive and highly selective detection of pathogen infections.

    Science.gov (United States)

    Yang, Haowen; Liang, Wenbiao; He, Nongyue; Deng, Yan; Li, Zhiyang

    2015-01-14

    Previously, the unique advantages provided by chemiluminescence (CL) and magnetic particles (MPs) have resulted in the development of many useful nucleic acid detection methods. CL is highly sensitive, but when applied to MPs, its intensity is limited by the inner filter-like effect arising from excess dark MPs. Herein, we describe a modified strategy whereby CL labels are released from MPs to eliminate this negative effect. This approach relies on (1) the magnetic capture of target molecules on long spacer arm-functionalized magnetic particles (LSA-MPs), (2) the conjugation of streptavidin-alkaline phosphatase (SA-AP) to biotinylated amplicons of target pathogens, (3) the release of CL labels (specifically, AP tags), and (4) the detection of the released labels. CL labels were released from LSA-MPs through LSA ultrasonication or DNA enzymolysis, which proved to be the superior method. In contrast to conventional MPs, LSA-MPs exhibited significantly improved CL detection, because of the introduction of LSA, which was made of water-soluble carboxymethylated β-1,3-glucan. Detection of hepatitis B virus with this technique revealed a low detection limit of 50 fM, high selectivity, and excellent reproducibility. Thus, this approach may hold great potential for early stage clinical diagnosis of infectious diseases.

  1. Magnetic Resonance Tracking of Endothelial Progenitor Cells Labeled with Alkyl-Polyethylenimine 2 kDa/Superparamagnetic Iron Oxide in a Mouse Lung Carcinoma Xenograft Model

    Directory of Open Access Journals (Sweden)

    Cong Chen

    2014-11-01

    Full Text Available The potential of using endothelial progenitor cells (EPCs in novel anticancer therapy and the repair of vascular injury has been increasingly recognized. In the present study, EPCs were labeled with N-alkyl-polyethylenimine 2 kDa (PEI2k-stabilized superparamagnetic iron oxide (SPIO to facilitate magnetic resonance imaging (MRI of EPCs in a mouse lung carcinoma xenograft model. EPCs derived from human peripheral blood were labeled with alkyl-PEI2k/SPIO. The viability and activity of labeled cells were evaluated using proliferation, migration, and tubulogenesis assays. Alkyl-PEI2k/SPIO-labeled EPCs were injected intravenously (group 1 or mixed and injected together with A549 cells subcutaneously (group 2 into groups of six mice with severe combined immunodeficiency. The labeling efficiency with alkyl-PEI2k/SPIO at 7 mg Fe/mL concentration was approximately 100%. Quantitative analysis of cellular iron was 6.062 ± 0.050 pg/cell. No significant effects on EPC proliferation, migration, or tubulogenesis were seen after labeling. Seventesla micro-MRI showed the presence of schistic or linear hypointense regions at the tumor margins starting from days 7 to 8 after EPC administration. This gradually extended into the inner tumor layers in group 1. In group 2, tumor growth was accompanied by dispersion of low-signal intensity regions inside the tumor. Iron-positive cells identified by Prussian blue dye were seen at the sites identified using MRI. Human CD31-positive cells and mouse CD31-positive cells were present in both groups. Labeling EPCs with alkyl-PEI2k/SPIO allows noninvasive magnetic resonance investigation of EPC involvement in tumor neovasculature and is associated with excellent biocompatibility and MRI sensitivity.

  2. Magnetic resonance studies of isotopically labeled paramagnetic proteins: (2FE-2S) ferredoxins

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, H.; Xia, B.; Chae, Y.K.; Westler, W.M.; Markley, J.L. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    Recent developments in NMR spectroscopy, especially multidimensional, multinuclear NMR techniques, have made NMR the most versatile tool available for studying protein structure and function in solution. Unlike diamagnetic proteins, paramagnetic proteins contain centers with unpaired electrons. These unpaired electrons interact with magnetic nuclei either through chemical bonds by a contact mechanism or through space by a pseudocontact mechanism. Such interactions make the acquisition and analysis of NMR spectra of paramagnetic proteins more challenging than those of diamagnetic proteins. Some NMR signals from paramagnetic proteins are shifted outside the chemical shift region characteristic of diamagnetic proteins; these {open_quotes}hyperfine-shifted{close_quotes} resonances originate from nuclei that interact with unpaired electrons from the paramagnetic center. The large chemical shift dispersion in spectra of paramagnetic proteins makes it difficult to excite the entire spectral window and leads to distortions in the baseline. Interactions with paramagnetic centers shorten T{sub 1} and T{sub 2} relaxation times of nuclei; the consequences are line broadening and lower spectral sensitivity. Scalar (through bond) and dipolar (through space) interactions between pairs of nuclei are what give rise to crosspeak signals in multi-dimensional NMR spectra of small diamagnetic proteins. When such interactions involve a nucleus that is strongly relaxed by interaction with a paramagnetic center, specialized methods may be needed for its detection or it may be completely undetectable by present nD NMR methods.

  3. Noninvasive measurements of regional cerebral perfusion in preterm and term neonates by magnetic resonance arterial spin labeling.

    Science.gov (United States)

    Miranda, Maria J; Olofsson, Kern; Sidaros, Karam

    2006-09-01

    Magnetic resonance arterial spin labeling (ASL) at 3 Tesla has been investigated as a quantitative technique for measuring regional cerebral perfusion (RCP) in newborn infants. RCP values were measured in 49 healthy neonates: 32 preterm infants born before 34 wk of gestation and 17 term-born neonates. Examinations were performed on unsedated infants at postmenstrual age of 39-40 wk in both groups. Due to motion, reliable data were obtained from 23 preterm and 6 term infants. Perfusion in the basal ganglia (39 and 30 mL/100 g/min for preterm and term neonates, respectively) was significantly higher (p neonates at term-equivalent age and in term neonates. Perfusion was significantly higher (p = 0.01) in the preterm group than in the term infants, indicating that RCP may be influenced by developmental and postnatal ages. This study demonstrates, for the first time, that noninvasive ASL at 3T may be used to measure RCP in healthy unsedated preterm and term neonates. ASL is, therefore, a viable tool that will allow serial studies of RCP in high-risk neonates.

  4. Deep transcranial magnetic stimulation for the treatment of auditory hallucinations: a preliminary open-label study.

    Science.gov (United States)

    Rosenberg, Oded; Roth, Yiftach; Kotler, Moshe; Zangen, Abraham; Dannon, Pinhas

    2011-02-09

    Schizophrenia is a chronic and disabling disease that presents with delusions and hallucinations. Auditory hallucinations are usually expressed as voices speaking to or about the patient. Previous studies have examined the effect of repetitive transcranial magnetic stimulation (TMS) over the temporoparietal cortex on auditory hallucinations in schizophrenic patients. Our aim was to explore the potential effect of deep TMS, using the H coil over the same brain region on auditory hallucinations. Eight schizophrenic patients with refractory auditory hallucinations were recruited, mainly from Beer Ya'akov Mental Health Institution (Tel Aviv university, Israel) ambulatory clinics, as well as from other hospitals outpatient populations. Low-frequency deep TMS was applied for 10 min (600 pulses per session) to the left temporoparietal cortex for either 10 or 20 sessions. Deep TMS was applied using Brainsway's H1 coil apparatus. Patients were evaluated using the Auditory Hallucinations Rating Scale (AHRS) as well as the Scale for the Assessment of Positive Symptoms scores (SAPS), Clinical Global Impressions (CGI) scale, and the Scale for Assessment of Negative Symptoms (SANS). This preliminary study demonstrated a significant improvement in AHRS score (an average reduction of 31.7% ± 32.2%) and to a lesser extent improvement in SAPS results (an average reduction of 16.5% ± 20.3%). In this study, we have demonstrated the potential of deep TMS treatment over the temporoparietal cortex as an add-on treatment for chronic auditory hallucinations in schizophrenic patients. Larger samples in a double-blind sham-controlled design are now being preformed to evaluate the effectiveness of deep TMS treatment for auditory hallucinations. This trial is registered with clinicaltrials.gov (identifier: NCT00564096).

  5. Deep transcranial magnetic stimulation for the treatment of auditory hallucinations: a preliminary open-label study

    Directory of Open Access Journals (Sweden)

    Zangen Abraham

    2011-02-01

    Full Text Available Abstract Background Schizophrenia is a chronic and disabling disease that presents with delusions and hallucinations. Auditory hallucinations are usually expressed as voices speaking to or about the patient. Previous studies have examined the effect of repetitive transcranial magnetic stimulation (TMS over the temporoparietal cortex on auditory hallucinations in schizophrenic patients. Our aim was to explore the potential effect of deep TMS, using the H coil over the same brain region on auditory hallucinations. Patients and methods Eight schizophrenic patients with refractory auditory hallucinations were recruited, mainly from Beer Ya'akov Mental Health Institution (Tel Aviv university, Israel ambulatory clinics, as well as from other hospitals outpatient populations. Low-frequency deep TMS was applied for 10 min (600 pulses per session to the left temporoparietal cortex for either 10 or 20 sessions. Deep TMS was applied using Brainsway's H1 coil apparatus. Patients were evaluated using the Auditory Hallucinations Rating Scale (AHRS as well as the Scale for the Assessment of Positive Symptoms scores (SAPS, Clinical Global Impressions (CGI scale, and the Scale for Assessment of Negative Symptoms (SANS. Results This preliminary study demonstrated a significant improvement in AHRS score (an average reduction of 31.7% ± 32.2% and to a lesser extent improvement in SAPS results (an average reduction of 16.5% ± 20.3%. Conclusions In this study, we have demonstrated the potential of deep TMS treatment over the temporoparietal cortex as an add-on treatment for chronic auditory hallucinations in schizophrenic patients. Larger samples in a double-blind sham-controlled design are now being preformed to evaluate the effectiveness of deep TMS treatment for auditory hallucinations. Trial registration This trial is registered with clinicaltrials.gov (identifier: NCT00564096.

  6. Sandwich immunoassay for alpha-fetoprotein in human sera using gold nanoparticle and magnetic bead labels along with resonance Rayleigh scattering readout

    International Nuclear Information System (INIS)

    Lu, Yao; Huang, Xiangyi; Ren, Jicun

    2013-01-01

    We describe a sensitive sandwich immunoassay for alpha-fetoprotein (AFP). It is making use of gold nanoparticles (GNPs) and magnetic beads (MBs) as labels, and of resonance Rayleigh scattering for detection. Two antibodies were labeled with GNPs and MBs, respectively, and MB-antigen-GNP complexes were formed in the presence of antigens. The MB labels also serve as solid phase carriers that can be used to magnetically separate the immuno complex. The GNP labels are used as optical probes, and Rayleigh scattering was used to determine the concentration of free GNPs-antibody after separation of the MB-antigen-GNP complexes. The concentration of AFP is related to the intensity of light scattered by free GNPs in the 13.6 pM to 436 pM concentration range, and the limit of detection is 13.6 pM. The method was applied to the determination of AFP in sera of cancer patients, and the results agree well with those obtained by conventional ELISA. (author)

  7. Umbilical cord mesenchymal stem cells labeled with multimodal iron oxide nanoparticles with fluorescent and magnetic properties: application for in vivo cell tracking

    Science.gov (United States)

    Sibov, Tatiana T; Pavon, Lorena F; Miyaki, Liza A; Mamani, Javier B; Nucci, Leopoldo P; Alvarim, Larissa T; Silveira, Paulo H; Marti, Luciana C; Gamarra, LF

    2014-01-01

    Here we describe multimodal iron oxide nanoparticles conjugated to Rhodamine-B (MION-Rh), their stability in culture medium, and subsequent validation of an in vitro protocol to label mesenchymal stem cells from umbilical cord blood (UC-MSC) with MION-Rh. These cells showed robust labeling in vitro without impairment of their functional properties, the viability of which were evaluated by proliferation kinetic and ultrastructural analyzes. Thus, labeled cells were infused into striatum of adult male rats of animal model that mimic late onset of Parkinson’s disease and, after 15 days, it was observed that cells migrated along the medial forebrain bundle to the substantia nigra as hypointense spots in T2 magnetic resonance imaging. These data were supported by short-term magnetic resonance imaging. Studies were performed in vivo, which showed that about 5 × 105 cells could be efficiently detected in the short term following infusion. Our results indicate that these labeled cells can be efficiently tracked in a neurodegenerative disease model. PMID:24531365

  8. Umbilical cord mesenchymal stem cells labeled with multimodal iron oxide nanoparticles with fluorescent and magnetic properties: application for in vivo cell tracking.

    Science.gov (United States)

    Sibov, Tatiana T; Pavon, Lorena F; Miyaki, Liza A; Mamani, Javier B; Nucci, Leopoldo P; Alvarim, Larissa T; Silveira, Paulo H; Marti, Luciana C; Gamarra, Lf

    2014-01-01

    Here we describe multimodal iron oxide nanoparticles conjugated to Rhodamine-B (MION-Rh), their stability in culture medium, and subsequent validation of an in vitro protocol to label mesenchymal stem cells from umbilical cord blood (UC-MSC) with MION-Rh. These cells showed robust labeling in vitro without impairment of their functional properties, the viability of which were evaluated by proliferation kinetic and ultrastructural analyzes. Thus, labeled cells were infused into striatum of adult male rats of animal model that mimic late onset of Parkinson's disease and, after 15 days, it was observed that cells migrated along the medial forebrain bundle to the substantia nigra as hypointense spots in T2 magnetic resonance imaging. These data were supported by short-term magnetic resonance imaging. Studies were performed in vivo, which showed that about 5 × 10(5) cells could be efficiently detected in the short term following infusion. Our results indicate that these labeled cells can be efficiently tracked in a neurodegenerative disease model.

  9. Novel Application of Time-Spatial Labeling Inversion Pulse Magnetic Resonance Imaging for Diagnosis of External Hydrocephalus.

    Science.gov (United States)

    Nakae, Shunsuke; Murayama, Kazuhiro; Adachi, Kazuhide; Kumai, Tadashi; Abe, Masato; Hirose, Yuichi

    2018-01-01

    Although a subdural fluid collection frequently is observed, diagnostic methods that differentiate between the subdural collection caused by external hydrocephalus and that caused by subdural hygroma have not been established. Here, we report a case of external hydrocephalus caused by Gliadel-induced eosinophilic meningitis that has been previously reported in only 1 case and can be diagnosed by time-spatial labeling inversion pulse magnetic resonance imaging (time-SLIP MRI). A tumor located in the left temporal was detected incidentally in an 81-year-old man by examination of a head injury. The tumor was surgically resected and diagnosed as a high-grade glioma during the surgery; Gliadel wafers subsequently were implanted. Three weeks after the resection, the patient showed disturbed consciousness, and computed tomography revealed a subdural fluid collection. The out-flow of cerebrospinal through the resection cavity was detected by time-SLIP MRI. Cerebrospinal tests indicated high white blood cell counts and high protein levels, with more than 90% of the white blood cell count comprising eosinophils. Therefore, we suspected that the subdural fluid collection was caused by external hydrocephalus because of Gliadel-induced eosinophilic meningitis. We surgically removed the Gliadel wafers and subsequently performed a surgery to insert a ventriculoperitoneal shunt. Histologic examination indicated eosinophilic accumulation around the Gliadel wafers. The patient's symptoms improved after the insertion of a ventriculoperitoneal shunt. In the present case, time-SLIP MRI was a useful and noninvasive method for diagnosing external hydrocephalus which was caused by eosinophilic meningitis because of Gliadel-induced eosinophilic meningitis. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Umbilical cord mesenchymal stem cells labeled with multimodal iron oxide nanoparticles with fluorescent and magnetic properties: application for in vivo cell tracking

    Directory of Open Access Journals (Sweden)

    Sibov TT

    2014-01-01

    Full Text Available Tatiana T Sibov,1,2 Lorena F Pavon,1 Liza A Miyaki,1 Javier B Mamani,1 Leopoldo P Nucci,1,2 Larissa T Alvarim,1,3 Paulo H Silveira,1 Luciana C Marti,1 LF Gamarra1–31Hospital Israelita Albert Einstein, São Paulo, Brazil; 2Departamento de Neurologia e Neurociências, Universidade Federal de São Paulo, São Paulo, Brazil; 3Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, BrazilAbstract: Here we describe multimodal iron oxide nanoparticles conjugated to Rhodamine-B (MION-Rh, their stability in culture medium, and subsequent validation of an in vitro protocol to label mesenchymal stem cells from umbilical cord blood (UC-MSC with MION-Rh. These cells showed robust labeling in vitro without impairment of their functional properties, the viability of which were evaluated by proliferation kinetic and ultrastructural analyzes. Thus, labeled cells were infused into striatum of adult male rats of animal model that mimic late onset of Parkinson's disease and, after 15 days, it was observed that cells migrated along the medial forebrain bundle to the substantia nigra as hypointense spots in T2 magnetic resonance imaging. These data were supported by short-term magnetic resonance imaging. Studies were performed in vivo, which showed that about 5 × 105 cells could be efficiently detected in the short term following infusion. Our results indicate that these labeled cells can be efficiently tracked in a neurodegenerative disease model.Keywords: mesenchymal stem cells, multimodal iron oxide nanoparticles, Rhodamine, magnetic resonance imaging, Parkinson's disease

  11. Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Ambros J. [Technical University of Munich (TUM), Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J. [Technical University of Munich, Department of Radiology, Klinikum rechts der Isar, Munich (Germany); Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga [TUM, Munich, Department of Hematology/Oncology, Klinikum rechts der Isar, Munich (Germany); Piontek, Guido; Schlegel, Juergen [TUM, Munich, Division of Neuropathology, Institute of Pathology, Klinikum rechts der Isar, Munich (Germany)

    2008-06-15

    New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8{sup +} T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

  12. Visualization of antigen-specific human cytotoxic T lymphocytes labeled with superparamagnetic iron-oxide particles

    International Nuclear Information System (INIS)

    Beer, Ambros J.; Holzapfel, Konstantin; Settles, Marcus; Rummeny, Ernst J.; Neudorfer, Juliana; Kroenig, Holger; Peschel, Christian; Bernhard, Helga; Piontek, Guido; Schlegel, Juergen

    2008-01-01

    New technologies are needed to characterize the migration and survival of antigen-specific T cells in vivo. In this study, we developed a novel technique for the labeling of human cytotoxic T lymphocytes with superparamagnetic iron-oxide particles and the subsequent depiction with a conventional 1.5-T magnetic resonance scanner. Antigen-specific CD8 + T lymphocytes were labeled with ferucarbotran by lipofection. The uptake of ferucarbotran was confirmed by immunofluorescence microscopy using a dextran-specific antibody, and the intracellular enrichment of iron was measured by atomic absorption spectrometry. The imaging of T cells was performed by magnetic resonance on day 0, 2, 7 and 14 after the labeling procedure. On day 0 and 2 post labeling, a pronounced shortening of T2*-relaxation times was observed, which diminished after 7 days and was not detectable anymore after 14 days, probably due to the retained mitotic activity of the labeled T cells. Of importance, the antigen-specific cytolytic activity of the T cells was preserved following ferucarbotran labeling. Efficient ferucarbotran labeling of functionally active T lymphocytes and their detection by magnetic resonance imaging allows the in vivo monitoring of T cells and, subsequently, will impact the further development of T cell-based therapies. (orig.)

  13. Integrating Cell Phone Imaging with Magnetic Levitation (i-LEV) for Label-Free Blood Analysis at the Point-of-Living.

    Science.gov (United States)

    Baday, Murat; Calamak, Semih; Durmus, Naside Gozde; Davis, Ronald W; Steinmetz, Lars M; Demirci, Utkan

    2016-03-02

    There is an emerging need for portable, robust, inexpensive, and easy-to-use disease diagnosis and prognosis monitoring platforms to share health information at the point-of-living, including clinical and home settings. Recent advances in digital health technologies have improved early diagnosis, drug treatment, and personalized medicine. Smartphones with high-resolution cameras and high data processing power enable intriguing biomedical applications when integrated with diagnostic devices. Further, these devices have immense potential to contribute to public health in resource-limited settings where there is a particular need for portable, rapid, label-free, easy-to-use, and affordable biomedical devices to diagnose and continuously monitor patients for precision medicine, especially those suffering from rare diseases, such as sickle cell anemia, thalassemia, and chronic fatigue syndrome. Here, a magnetic levitation-based diagnosis system is presented in which different cell types (i.e., white and red blood cells) are levitated in a magnetic gradient and separated due to their unique densities. Moreover, an easy-to-use, smartphone incorporated levitation system for cell analysis is introduced. Using our portable imaging magnetic levitation (i-LEV) system, it is shown that white and red blood cells can be identified and cell numbers can be quantified without using any labels. In addition, cells levitated in i-LEV can be distinguished at single-cell resolution, potentially enabling diagnosis and monitoring, as well as clinical and research applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Migration of iron-labeled KHYG-1 natural killer cells to subcutaneous tumors in nude mice, as detected by magnetic resonance imaging.

    Science.gov (United States)

    Mallett, Christiane L; McFadden, Catherine; Chen, Yuhua; Foster, Paula J

    2012-07-01

    A novel cell line of cytotoxic natural killer (NK) cells, KHYG-1, was examined in vivo for immunotherapy against prostate cancer. The feasibility of using magnetic resonance imaging (MRI) tracking to monitor the fate of injected NK cells following intravenous (i.v.), intraperitoneal (i.p.) and subcutaneous (s.c.) administration was assessed. PC-3M human prostate cancer cells were injected s.c. into the flank of nude mice (day 0). KHYG-1 NK cells were labeled with an iron oxide contrast agent and injected s.c., i.v. or i.p. on day 8. Mice were imaged by MRI on days 7, 9 and 12. Tumor sections were examined with fluorescence microscopy and immunohistologic staining for NK cells. NK cells were detected in the tumors by histology after all three administration routes. NK cells and fluorescence from the iron label were co-localized. Signal loss was seen in the areas around the tumors and between the tumor lobes in the s.c. group. We are the first to label this cell line of NK cells with an iron oxide contrast agent. Accumulation of NK cells was visualized by MRI after s.c. injection but not after i.v. and i.p. injection.

  15. Measurement of cerebral white matter perfusion using pseudocontinuous arterial spin labeling 3T magnetic resonance imaging--an experimental and theoretical investigation of feasibility.

    Directory of Open Access Journals (Sweden)

    Wen-Chau Wu

    Full Text Available PURPOSE: This study was aimed to experimentally and numerically investigate the feasibility of measuring cerebral white matter perfusion using pseudocontinuous arterial spin labeling (PCASL 3T magnetic resonance imaging (MRI at a relatively fine resolution to mitigate partial volume effect from gray matter. MATERIALS AND METHODS: The Institutional Research Ethics Committee approved this study. On a clinical 3T MR system, ten healthy volunteers (5 females, 5 males, age = 28 ± 3 years were scanned after providing written informed consent. PCASL imaging was performed with varied combinations of labeling duration (τ = 1000, 1500, 2000, and 2500 ms and post-labeling delay (PLD = 1000, 1400, 1800, and 2200 ms, at a spatial resolution (1.56 x 1.56 x 5 mm(3 finer than commonly used (3.5 x 3.5 mm(2, 5-8 mm in thickness. Computer simulations were performed to calculate the achievable perfusion-weighted signal-to-noise ratio at varied τ, PLD, and transit delay. RESULTS: Based on experimental and numerical data, the optimal τ and PLD were found to be 2000 ms and 1500-1800 ms, respectively, yielding adequate SNR (~2 to support perfusion measurement in the majority (~60% of white matter. The measurement variability was about 9% in a one-week interval. The measured white matter perfusion and perfusion ratio of gray matter to white matter were 15.8-27.5 ml/100ml/min and 1.8-4.0, respectively, depending on spatial resolution as well as the amount of deep white matter included. CONCLUSION: PCASL 3T MRI is able to measure perfusion in the majority of cerebral white matter at an adequate signal-to-noise ratio by using appropriate tagging duration and post-labeling delay. Although pixel-wise comparison may not be possible, region-of-interest based flow quantification is feasible.

  16. Comparison of Superparamagnetic Iron Oxide Labeling Efficiency between Poly-L-Lysine and Protamine Sulfate for Human Mesenchymal Stem Cells: Quantitative Analysis Using Multi-Echo T2 Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Suh, Ji Yeon; Lee, Jeong Hyun; Lee, Chang Kyung; Shin, Ji Hoon; Choi, Choong Gon; Kim, Jeong Kon

    2013-01-01

    To quantify in vitro labeling efficiency of protamine sulfate (PS) and poly-L-lysine (PLL) for labeling of human mesenchymal stem cells (hMSCs) with superparamagnetic iron oxide (SPIO) using multi-echo T2 magnetic resonance (MR) imaging at 4.7 T. The hMSCs were incubated with SPIO-PS or SPIO-PLL complexes. Their effects on the cell metabolism and differentiation capability were evaluated, respectively. The decrease of iron concentrations in the labeled cells were assessed immediately, and at 4 d after labeling using multi-echo T2 MR imaging at 4.7 T. The results were compared with those of Prussian blue colorimetry. The hMSCs were labeled more efficiently by SPIO-PLL than SPIO-PS without any significant effect on cell metabolism and differentiation capabilities. It was feasible to quantify the iron concentrations in SPIO-agarose-phantoms and in agarose mixture with the labeled cells from T2 maps obtained from multi-echo T2 MRI. However, the iron concentration of the labeled cells was significantly higher by T2-maps than the results of Prussian blue colorimetry. The hMSCs can be effectively labeled with SPIO-PLL complexes more than with SPIO-PS without significant change in cell metabolism and differentiation. In vitro quantification of the iron concentrations of the labeled is feasible from multi-echo T2 MRI, but needs further investigation.

  17. Comparison of Superparamagnetic Iron Oxide Labeling Efficiency between Poly-L-Lysine and Protamine Sulfate for Human Mesenchymal Stem Cells: Quantitative Analysis Using Multi-Echo T2 Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Ji Yeon; Lee, Jeong Hyun; Lee, Chang Kyung; Shin, Ji Hoon; Choi, Choong Gon; Kim, Jeong Kon [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2013-02-15

    To quantify in vitro labeling efficiency of protamine sulfate (PS) and poly-L-lysine (PLL) for labeling of human mesenchymal stem cells (hMSCs) with superparamagnetic iron oxide (SPIO) using multi-echo T2 magnetic resonance (MR) imaging at 4.7 T. The hMSCs were incubated with SPIO-PS or SPIO-PLL complexes. Their effects on the cell metabolism and differentiation capability were evaluated, respectively. The decrease of iron concentrations in the labeled cells were assessed immediately, and at 4 d after labeling using multi-echo T2 MR imaging at 4.7 T. The results were compared with those of Prussian blue colorimetry. The hMSCs were labeled more efficiently by SPIO-PLL than SPIO-PS without any significant effect on cell metabolism and differentiation capabilities. It was feasible to quantify the iron concentrations in SPIO-agarose-phantoms and in agarose mixture with the labeled cells from T2 maps obtained from multi-echo T2 MRI. However, the iron concentration of the labeled cells was significantly higher by T2-maps than the results of Prussian blue colorimetry. The hMSCs can be effectively labeled with SPIO-PLL complexes more than with SPIO-PS without significant change in cell metabolism and differentiation. In vitro quantification of the iron concentrations of the labeled is feasible from multi-echo T2 MRI, but needs further investigation.

  18. Protein surface labeling reactivity of N-hydroxysuccinimide esters conjugated to Fe{sub 3}O{sub 4}@SiO{sub 2} magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pirani, Parisa; Patil, Ujwal S.; Apsunde, Tushar Dattu; Trudell, Mark L.; Cai, Yang, E-mail: ycai@chnola-research.org; Tarr, Matthew A., E-mail: mtarr@uno.edu [University of New Orleans, Department of Chemistry (United States)

    2015-09-15

    The N-hydroxysuccinimide (NHS) ester moiety is one of the most widely used amine reactive groups for covalent conjugation of proteins/peptides to other functional targets. In this study, a cleave-analyze approach was developed to quantify NHS ester groups conjugated to silica-coated iron oxide magnetic nanoparticles (Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs). The fluorophore dansylcadaverine was attached to Fe{sub 3}O{sub 4}@SiO{sub 2} magnetic nanoparticles (MNPs) via reaction with NHS ester groups, and then released from the MNPs by cleavage of the disulfide bond in the linker between the fluorophore and the MNPs moiety. The fluorophore released from Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs was fluorometrically measured, and the amount of fluorophore should be equivalent to the quantity of the NHS ester groups on the surface of Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs that participated in the fluorophore conjugation reaction. Another sensitive and semiquantitative fluorescence microscopic test was also developed to confirm the presence of NHS ester groups on the surface of Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs. Surface-conjugated NHS ester group measurements were primarily performed on Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs of 100–150 nm in diameter and also on 20-nm nanoparticles of the same type but prepared by a different method. The efficiency of labeling native proteins by NHS ester-coated Fe{sub 3}O{sub 4}@SiO{sub 2} MNPs was explored in terms of maximizing the number of MNPs conjugated per BSA molecule or maximizing the number of BSA molecules conjugated per each nanoparticle. Maintaining the amount of fresh NHS ester moieties in the labeling reaction system was essential especially when maximizing the number of MNPs conjugated per protein molecule. The methodology demonstrated in this study can serve as a guide in labeling the exposed portions of proteins by bulky multivalent labeling reagents.

  19. Magnetic resonance and photoacoustic imaging of brain tumor mediated by mesenchymal stem cell labeled with multifunctional nanoparticle introduced via carotid artery injection

    Science.gov (United States)

    Qiao, Yang; Gumin, Joy; MacLellan, Christopher J.; Gao, Feng; Bouchard, Richard; Lang, Frederick F.; Stafford, R. Jason; Melancon, Marites P.

    2018-04-01

    Objective. To evaluate the feasibility of visualizing bone marrow-derived human mesenchymal stem cells (MSCs) labeled with a gold-coated magnetic resonance (MR)-active multifunctional nanoparticle and injected via the carotid artery for assessing the extent of MSC homing in glioma-bearing mice. Materials and methods. Nanoparticles containing superparamagnetic iron oxide coated with gold (SPIO@Au) with a diameter of ˜82 nm and maximum absorbance in the near infrared region were synthesized. Bone marrow-derived MSCs conjugated with green fluorescent protein (GFP) were successfully labeled with SPIO@Au at 4 μg ml-1 and injected via the internal carotid artery in six mice bearing orthotopic U87 tumors. Unlabeled MSCs were used as a control. The ability of SPIO@Au-loaded MSCs to be imaged using MR and photoacoustic (PA) imaging at t = 0 h, 2 h, 24 h, and 72 h was assessed using a 7 T Bruker Biospec experimental MR scanner and a Vevo LAZR PA imaging system with a 5 ns laser as the excitation source. Histological analysis of the brain tissue was performed 72 h after MSC injection using GFP fluorescence, Prussian blue staining, and hematoxylin-and-eosin staining. Results. MSCs labeled with SPIO@Au at 4 μg ml-1 did not exhibit cell death or any adverse effects on differentiation or migration. The PA signal in tumors injected with SPIO@Au-loaded MSCs was clearly more enhanced post-injection, as compared with the tumors injected with unlabeled MSCs at t = 72 h. Using the same mice, T2-weighted MR imaging results taken before injection and at t = 2 h, 24 h, and 72 h were consistent with the PA imaging results, showing significant hypointensity of the tumor in the presence of SPIO@Au-loaded MSCs. Histological analysis also showed co-localization of GFP fluorescence and iron, thereby confirming that SPIO@Au-labeled MSCs continue to carry their nanoparticle payloads even at 72 h after injection. Conclusions. Our results demonstrated the feasibility of tracking carotid artery

  20. Food Labels

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Food Labels KidsHealth / For Teens / Food Labels What's in ... to have at least 95% organic ingredients. Making Food Labels Work for You The first step in ...

  1. In Vivo MR Imaging of Magnetically Labeled Mesenchymal Stem Cells in a Rat Model of Renal Ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Sung Il [Konkuk University Medical Center, Seoul (Korea, Republic of); Kim, Seung Hyup [Seoul National University Medical Research Center, Seoul (Korea, Republic of); Kim, Hyo Cheol; Chung, Se Young; Moon, Woo Kyung; Kim, Hoe Suk [Seoul National University Hospital, Seoul (Korea, Republic of); Choi, Jong Sun [Dongguk University International Hospital, Goyang (Korea, Republic of); Moon, Min Hoan [Cheil General Hospital and Women' s Healthcare Center, Seoul (Korea, Republic of); Son, Kyu Ri; Sung, Chang Kyu [Seoul National University Boramae Hospital, Seoul (Korea, Republic of)

    2009-06-15

    This study was designed to evaluate in vivo MR imaging for the depiction of intraarterially injected superparamagnetic iron oxide (SPIO)-labeled mesenchymal stem cells (MSCs) in an experimental rat model of renal ischemia. Left renal ischemia was induced in 12 male Sprague- Dawley rats by use of the catheter lodging method. In vivo MR signal intensity variations depicted on T2*-weighted sequences were evaluated in both the left and right kidneys prior to injection (n = 2), two hours (n = 4), 15 hours (n = 2), 30 hours (n = 2) and 72 hours (n = 2) after injection of SPIO-labeled MSCs in both kidneys. Signal intensity variations were correlated with the number of Prussian blue stain-positive cells as visualized in histological specimens. In an in vivo study, it was determined that there was a significant difference in signal intensity variation for both the left and right cortex (40.8 {+-} 4.12 and 26.4 {+-} 7.92, respectively) and for both the left and right medulla (23.2 {+-} 3.32 and 15.2 {+-} 3.31, respectively) until two hours after injection (p < 0.05). In addition, signal intensity variation in the left renal cortex was well correlated with the number of Prussian blue stain-positive cells per high power field (r = 0.98, p < 0.05). Intraarterial injected SPIO-labeled MSCs in an experimental rat model of renal ischemia can be detected with the use of in vivo MR imaging immediately after injection.

  2. Nuclear magnetic resonance study of interaction of ligands with Streptococcus faecium dihydrofolate reductase labeled with [#betta#-13C]tryptophan

    International Nuclear Information System (INIS)

    London, R.E.; Groff, J.P.; Cocco, L.; Blakley, R.L.

    1982-01-01

    Dihydrofolate reductase from Streptococcus faecium has been labeled with [#betta#- 13 C]tryptophan. We have determined changes occurring in the chemical shifts and line widths of the four resonances of the 13 C NMR spectrum of the labeled enzyme, due to its interaction with various ligands. These include the coenzyme, NPDPH and related nucleotides, folate and its polyglutamate derivatives, and many inhibitors including methotrexate and trimethoprim. In addition, paramagnetic relaxation effects produced by a bound spin-labeled analogue of 2'-phosphoadenosine-5'-diphosphoribose on the tryptophan C/sup #betta#/ carbons have been measured. Distances calculated from the relaxation data have been compared with corresponding distances in the crystallographic model of the NADPH-methotrexate ternary complex of Lactobacillus casei reductase. The paramagnetic relaxation data indicate that the two downfield resonances (1 and 2) correspond to tryptophans (W/sub A/ and W/sub B/) that are more remote from the catalytic site, and from the crystallographic model these are seen to be Trp-115 and Trp-160. The upfield resonances (3 and 4) that show broadening due to chemical exchange correspond to closer residues (W/sub C/ and W/sub D/), and these are identified with Trp-6 and Trp-22. However, the relaxation data do not permit specific assignments within the nearer and farther pairs. Although resonance 3, which is split due to chemical exchange, was formerly assigned to Trp-6, data obtained for the enzyme in the presence of various ligands are better interpreted if resonance 3 is assigned to Trp-22, which is located on a loop that joins elements of secondary structure and forms one side of the ligand-binding cavity

  3. Intracellular protein breakdown. 8

    International Nuclear Information System (INIS)

    Bohley, P.; Kirschke, H.; Langner, J.; Wiederanders, B.; Ansorge, S.

    1976-01-01

    Double-labelled proteins from rat liver cytosol ( 14 C in long-lived, 3 H in short-lived proteins after in-vivo-labelling) are used as substrates for unlabelled proteinases in vitro. Differences in the degradation rates of short-lived and long-lived proteins in vitro by different proteinases and after addition of different effectors allow conclusions concerning their importance for the in-vivo-turnover of substrate proteins. The main activity (>90%) of soluble lysosomal proteinases at pH 6.1 and pH 6.9 is caused by thiolproteinases, which degrade preferentially short-lived cytosol proteins. These proteinases are inhibited by leupeptin. Autolysis of double-labelled cell fractions shows a remarkably faster breakdown of short-lived substrate proteins only in the soluble part of lysosomes. Microsomal fractions degrade in vitro preferentially long-lived substrate proteins. (author)

  4. Longitudinal Assessment of Renal Perfusion and Oxygenation in Transplant Donor-Recipient Pairs Using Arterial Spin Labeling and Blood Oxygen Level-Dependent Magnetic Resonance Imaging.

    Science.gov (United States)

    Niles, David J; Artz, Nathan S; Djamali, Arjang; Sadowski, Elizabeth A; Grist, Thomas M; Fain, Sean B

    2016-02-01

    The aims of this study were to assess renal function in kidney transplant recipients and their respective donors over 2 years using arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) and to prospectively evaluate the effect of losartan on functional MRI measures in recipients. The study included 15 matched pairs of renal transplant donors and recipients. Arterial spin labeling and BOLD MRI of the kidneys were performed on donors before transplant surgery (baseline) and on both donors and recipients at 3 months, 1 year, and 2 years after transplant. After 3 months, 7 of the 15 recipients were prescribed 25 to 50 mg/d losartan for the remainder of the study. A linear mixed-effects model was used to evaluate perfusion, R2*, estimated glomerular filtration rate, and fractional excretion of sodium for changes across time or associated with losartan treatment. In donors, cortical perfusion in the remaining kidney decreased by 50 ± 19 mL/min per 100 g (11.8%) between baseline and 2 years (P donors and to 14.6 ± 4.3 mL/min per 1.73 m (33.3%; P donors, and they indicate a potentially beneficial effect of losartan in recipients.

  5. Core–shell Fe3O4–Au magnetic nanoparticles based nonenzymatic ultrasensitive electrochemiluminescence immunosensor using quantum dots functionalized graphene sheet as labels

    International Nuclear Information System (INIS)

    Liu, Weiyan; Zhang, Yan; Ge, Shenguang; Song, Xianrang; Huang, Jiadong; Yan, Mei; Yu, Jinghua

    2013-01-01

    Graphical abstract: Core–shell Fe 3 O 4 –Au magnetic nanoparticles and P-GS@QDs were prepared to immobilize Ab 1 and Ab 2 respectively and combined to fabricate a novel sandwich-type ECL immunosensor for detecting CA125 at low concentration. Highlights: ► ECL immunosensor for CA125 based on a microfluidic strategy with a homemade ECL cell was proposed. ► Core–shell Fe 3 O 4 –Au magnetic nanoparticles were employed as the carriers of the primary antibodies. ► CdTe quantum dots functionalized graphene sheet were used for signal amplification. -- Abstract: In this paper, a novel, low-cost electrochemiluminescence (ECL) immunosensor using core–shell Fe 3 O 4 –Au magnetic nanoparticles (AuMNPs) as the carriers of the primary antibody of carbohydrate antigen 125 (CA125) was designed. Graphene sheet (GS) with property of good conductivity and large surface area was a captivating candidate to amplify ECL signal. We successively synthesized functionalized GS by loading large amounts of quantum dots (QDs) onto the poly (diallyldimethyl-ammonium chloride) (PDDA) coated graphene sheet (P-GS@QDs) via self-assembly electrostatic reactions, which were used to label secondary antibodies. The ECL immunosensors coupled with a microfluidic strategy exhibited a wide detection range (0.005–50 U mL −1 ) and a low detection limit (1.2 mU mL −1 ) with the help of an external magnetic field to gather immunosensors. The method was evaluated with clinical serum sample, receiving good correlation with results from commercially available analytical procedure

  6. Alzheimer's disease biomarkers detection in human samples by efficient capturing through porous magnetic microspheres and labelling with electrocatalytic gold nanoparticles

    Czech Academy of Sciences Publication Activity Database

    de la Escosura-Muniz, A.; Plichta, Zdeněk; Horák, Daniel; Merkoci, A.

    2015-01-01

    Roč. 67, 15 May (2015), s. 162-169 ISSN 0956-5663 R&D Projects: GA MŠk 7E12053 EU Projects: European Commission(XE) 246513 - NADINE Institutional support: RVO:61389013 Keywords : porous magnetic microspheres * gold nanoparticles * electrochemical immunoassay Subject RIV: CD - Macromolecular Chemistry Impact factor: 7.476, year: 2015

  7. Nanoneedles for intracellular applications

    KAUST Repository

    Kosel, Jurgen

    2017-07-13

    Nanoneedles and nanoneedle arrays and methods of making nanoneedles are provided. The methods can include multilayer fabrication methods using a negative photoresist and/or a positive photoresist. The nanoneedle arrays include one or more nanoneedles attached to a surface of a substrate. The nanoneedle can have both a proximal opening and a distal opening, and an inner passageway connecting the proximal opening and the distal opening. The nanoneedle can have a functional coating. The nanoneedle can include iron, cobalt, nickel, gold, and oxides and alloys thereof. The nanoneedle arrays can be used for the administration and/or the extraction of agents from individual cells. In one or more aspects, the nanoneedles can be magnetic nanoneedles. An oscillating magnetic field applied to a magnetic nanoneedle can induce one or both of heating and vibration of the magnetic nanoneedle. The heating and/or vibration can cause a magnetic nanoneedle to penetrate the wall of a cell.

  8. The role of magnetic resonance diffusion-weighted imaging and three-dimensional arterial spin labelling perfusion imaging in the differentiation of parasellar meningioma and cavernous haemangioma.

    Science.gov (United States)

    Xiao, Hua-Feng; Lou, Xin; Liu, Meng-Yu; Wang, Yu-Lin; Wang, Yan; Chen, Zhi-Ye; Shi, Kai-Ning; Ma, Lin

    2014-08-01

    To evaluate the diagnostic value of magnetic resonance diffusion-weighted imaging (DWI) and three-dimensional arterial spin labelling perfusion imaging (3D-ASL) in distinguishing cavernous haemangioma from parasellar meningioma, using histological data as a reference standard. Patients with parasellar meningioma or parasellar cavernous haemangioma underwent conventional T1- and T2-weighted magnetic resonance imaging (MRI) followed by DWI and 3D-ASL using a 3.0 Tesla MRI. The minimum apparent diffusion coefficient (minADC) from DWI and the maximal normalized cerebral blood flow (nCBF) from 3D-ASL were measured in each tumour. Diagnosis was confirmed by histology. MinADC was significantly lower and nCBF significantly higher in meningioma (n = 19) than cavernous haemangioma (n = 15). There was a significant negative correlation between minADC and nCBF (r = -0.605). DWI and 3D-ASL are useful in differentiating cavernous haemangiomas from parasellar meningiomas, particularly in situations when the appearance on conventional MRI sequences is otherwise ambiguous. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  9. Magnets

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)

  10. Functionalized graphene oxide/Fe3O4 hybrids for cellular magnetic resonance imaging and fluorescence labeling.

    Science.gov (United States)

    Zhou, Chaohui; Wu, Hui; Wang, Mingliang; Huang, Chusen; Yang, Dapeng; Jia, Nengqin

    2017-09-01

    In this work, we developed a T 2 -weighted contrast agent based on graphene oxide (GO)/Fe 3 O 4 hybrids for efficient cellular magnetic resonance imaging (MRI). The GO/Fe 3 O 4 hybrids were obtained by combining with co-precipitation method and pyrolysis method. The structural, surface and magnetic characteristics of the hybrids were systematically characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), AFM, Raman, FT-IR and XRD. The GO/Fe 3 O 4 hybrids were functionalized by modifying with anionic and cationic polyelectrolyte through layer-by-layer assembling. The fluorescence probe fluorescein isothiocyanate (FITC) was further loaded on the surface of functionalized GO/Fe 3 O 4 hybrids to trace the location of GO/Fe 3 O 4 hybrids in cells. Functionalized GO/Fe 3 O 4 hybrids possess good hydrophilicity, less cytotoxicity, high MRI enhancement with the relaxivity (r 2 ) of 493mM -1 s -1 as well as cellular MRI contrast effect. These obtained results indicated that the functionalized GO/Fe 3 O 4 hybrids could have great potential to be utilized as cellular MRI contrast agents for tumor early diagnosis and monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Evaluation of Renal Blood Flow in Chronic Kidney Disease Using Arterial Spin Labeling Perfusion Magnetic Resonance Imaging.

    Science.gov (United States)

    Li, Lu-Ping; Tan, Huan; Thacker, Jon M; Li, Wei; Zhou, Ying; Kohn, Orly; Sprague, Stuart M; Prasad, Pottumarthi V

    2017-01-01

    Chronic kidney disease (CKD) is known to be associated with reduced renal blood flow. However, data to-date in humans is limited. In this study, non-invasive arterial spin labeling (ASL) MRI data was acquired in 33 patients with diabetes and stage-3 CKD, and 30 healthy controls. A significantly lower renal blood flow both in cortex (108.4±36.4 vs . 207.3±41.8; pblood flow were correlated with eGFR, and cortical blood flow was found to be confounded by age and BMI. However, in a subset of subjects that were matched for age and BMI (n=6), the differences between CKD and control subjects remained significant both in cortex (107.4±42.8 vs . 187.51±20.44; p=0.002) and medulla (15.43±8.43 vs . 39.18±11.13; p=0.002). A threshold value to separate healthy and CKD was estimated to be Cor_BF=142.9 and Med_BF=24.1. These results support the use of ASL in the evaluation of renal blood flow in patients with moderate level of CKD. Whether these measurements can identify subjects at risk of progressive CKD requires further longitudinal follow-up.

  12. Determination of avian influenza A (H9N2) virions by inductively coupled plasma mass spectrometry based magnetic immunoassay with gold nanoparticles labeling

    Science.gov (United States)

    Xiao, Guangyang; Chen, Beibei; He, Man; Shi, Kaiwen; Zhang, Xing; Li, Xiaoting; Wu, Qiumei; Pang, Daiwen; Hu, Bin

    2017-12-01

    Avian influenza viruses are the pathogens of global poultry epidemics, and may even cause the human infections. Here, we proposed a novel inductively coupled plasma mass spectrometry (ICP-MS) based immunoassay with gold nanoparticles (Au NPs) labeling for the determination of H9N2 virions. Magnetic-beads modified with anti-influenza A H9N2 hemagglutinin mono-antibody (mAb-HA) were utilized for the capture of H9N2 virions in complex matrix; and Au NPs conjugated with mAb-HA were employed for the specific labeling of H9N2 virions for subsequent ICP-MS detection. With a sandwich immunoassay strategy, this method exhibited a high specificity for H9N2 among other influenza A virions such as H1N1 and H3N2. Under the optimized conditions, this method could detect as low as 0.63 ng mL- 1 H9N2 virions with the linear range of 2-400 ng mL- 1, the relative standard deviation for seven replicate detections of H9N2 virions was 7.2% (c = 10 ng mL- 1). The developed method was applied for the detection of H9N2 virions in real-world chicken dung samples, and the recovery for the spiking samples was 91.4-116.9%. This method is simple, rapid, sensitive, selective, reliable and has a good application potential for virions detection in real-world samples.

  13. The radioactive labeling of monocytes

    International Nuclear Information System (INIS)

    Ensing, G.J.

    1985-01-01

    With the aim of studying a possible relationship between circulating monocytes and Sternberg-Reed cells investigations were started on the specific labeling of monocytes. In this thesis the literature on the pertinent data has been reviewed and a series of experiments on the monocyte labeling procedure has been described. The principles of cell labeling with radioactive compounds were discussed. 1. Total separation of the particular cell population to be labeled and subsequent labeling with a non-specific radiopharmaceutical. 2. Specific cell labeling in a mixture of cell types based on a well defined affinity of the cell under study for the radiopharmaceutical used. Next the radionuclides that can be used for cell labeling purposes were discussed with special attention for 111 In and its chelates. The principles of radiodosimetry were also discussed shortly. This section was focussed on the radiation dose the labeled cells receive because of the intracellular localized radioactivity. The radiation burden is high in comparison to amounts of radiation known to affect cell viability. A newly developed method for labeling monocytes specifically by phagocytosis of 111 In-Fe-colloid without apparent loss of cells was described in detail. (Auth.)

  14. Nanoneedles for intracellular applications

    KAUST Repository

    Kosel, Jü rgen; Kavaldzhiev, Mincho Nikolaev; Perez, Jose Efrain

    2017-01-01

    can include iron, cobalt, nickel, gold, and oxides and alloys thereof. The nanoneedle arrays can be used for the administration and/or the extraction of agents from individual cells. In one or more aspects, the nanoneedles can be magnetic nanoneedles

  15. Design principles and theory of paramagnetic fluorine-labelled lanthanide complexes as probes for (19)F magnetic resonance: a proof-of-concept study.

    Science.gov (United States)

    Chalmers, Kirsten H; De Luca, Elena; Hogg, Naomi H M; Kenwright, Alan M; Kuprov, Ilya; Parker, David; Botta, Mauro; Wilson, J Ian; Blamire, Andrew M

    2010-01-04

    The synthesis and spectroscopic properties of a series of CF(3)-labelled lanthanide(III) complexes (Ln=Gd, Tb, Dy, Ho, Er, Tm) with amide-substituted ligands based on 1,4,7,10-tetraazacyclododecane are described. The theoretical contributions of the (19)F magnetic relaxation processes in these systems are critically assessed and selected volumetric plots are presented. These plots allow an accurate estimation of the increase in the rates of longitudinal and transverse relaxation as a function of the distance between the Ln(III) ion and the fluorine nucleus, the applied magnetic field, and the re-rotational correlation time of the complex, for a given Ln(III) ion. Selected complexes exhibit pH-dependent chemical shift behaviour, and a pK(a) of 7.0 was determined in one example based on the holmium complex of an ortho-cyano DO3A-monoamide ligand, which allowed the pH to be assessed by measuring the difference in chemical shift (varying by over 14 ppm) between two (19)F resonances. Relaxation analyses of variable-temperature and variable-field (19)F, (17)O and (1)H NMR spectroscopy experiments are reported, aided by identification of salient low-energy conformers by using density functional theory. The study of fluorine relaxation rates, over a field range of 4.7 to 16.5 T allowed precise computation of the distance between the Ln(III) ion and the CF(3) reporter group by using global fitting methods. The sensitivity benefits of using such paramagnetic fluorinated probes in (19)F NMR spectroscopic studies are quantified in preliminary spectroscopic and imaging experiments with respect to a diamagnetic yttrium(III) analogue.

  16. Recombinant high-density lipoprotein nanoparticles containing gadolinium-labeled cholesterol for morphologic and functional magnetic resonance imaging of the liver

    Directory of Open Access Journals (Sweden)

    Rui M

    2012-07-01

    Full Text Available Mengjie Rui,1 Wei Guo,2 Qian Ding,2 Xiaohui Wei,2 Jianrong Xu,3 Yuhong Xu21School of Life Science and Biotechnology, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China; 3Department of Radiology, Renji Hospital Affiliation with Medical School of Shanghai Jiao Tong University, Shanghai, People's Republic of ChinaBackground: Natural high-density lipoproteins (HDL possess important physiological functions to the transport of cholesterol from the peripheral tissues to the liver for metabolic degradation and excretion in the bile.Methods and results: In this work, we took advantage of this pathway and prepared two different gadolinium (Gd-DTPA-labeled cholesterol-containing recombinant HDL nanoparticles (Gd-chol-HDL and Gd-(chol2-HDL as liver-specific magnetic resonance imaging (MRI contrast agents. The reconstituted HDL nanoparticles had structural similarity to native HDL, and could be taken up by HepG2 cells via interaction with HDL receptors in vitro. In vivo MRI studies in rats after intravenous injections of 10 µmol gadolinium per kg of recombinant HDL nanoparticles indicated that both nanoparticles could provide signal enhancement in the liver and related organs. However, different T1-weighted image details suggested that they participated in different cholesterol metabolism and excretion pathways in the liver.Conclusion: Such information could be highly useful to differentiate functional changes as well as anatomic differences in the liver. These cholesterol-derived contrast agents and their recombinant HDL preparations may warrant further development as a new class of contrast agents for MRI of the liver and related organs.Keywords: magnetic resonance imaging, apolipoprotein, high-density lipoprotein, contrast agent, gadolinium, liver

  17. Gd-labeled glycol chitosan as a pH-responsive magnetic resonance imaging agent for detecting acidic tumor microenvironments.

    Science.gov (United States)

    Nwe, Kido; Huang, Ching-Hui; Tsourkas, Andrew

    2013-10-24

    Neoplastic lesions can create a hostile tumor microenvironment with low extracellular pH. It is commonly believed that these conditions can contribute to tumor progression as well as resistance to therapy. We report the development and characterization of a pH-responsive magnetic resonance imaging contrast agent for imaging the acidic tumor microenvironment. The preparation included the conjugation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid 1-(2,5-dioxo-1-pyrrolidinyl) ester (DOTA-NHS) to the surface of a water-soluble glycol chitosan (GC) polymer, which contains pH-titrable primary amines, followed by gadolinium complexation (GC-NH2-GdDOTA). GC-NH2-GdDOTA had a chelate-to-polymer ratio of approximately1:24 and a molar relaxivity of 9.1 mM(-1) s(-1). GC-NH2-GdDOTA demonstrated pH-dependent cellular association in vitro compared to the control. It also generated a 2.4-fold enhancement in signal in tumor-bearing mice 2 h postinjection. These findings suggest that glycol chitosan coupled with contrast agents can provide important diagnostic information about the tumor microenvironment.

  18. Evaluation of the applicability of territorial arterial spin labeling in meningiomas for presurgical assessments compared with 3-dimensional time-of-flight magnetic resonance angiography

    International Nuclear Information System (INIS)

    Lu, Yiping; Wen, Jianbo; Geng, Daoying; Yin, Bo; Luan, Shihai; Liu, Li; Xiong, Ji; Qu, Jianxun

    2017-01-01

    To prospectively evaluate the application of territorial arterial spin labelling (t-ASL) in comparison with unenhanced three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) in the identification of the feeding vasculature of meningiomas. Thirty consecutive patients with suspected meningiomas underwent conventional MR imaging, unenhanced 3D-TOF-MRA and t-ASL scanning. Four experienced neuro-radiologists assessed the feeding vessels with different techniques separately. For the identification of the origin of the feeding arteries on t-ASL, the inter-observer agreement was excellent (κ = 0.913), while the inter-observer agreement of 3D-TOF-MRA was good (κ = 0.653). The inter-modality agreement between t-ASL and 3D-TOF-MRA for the feeding arteries was moderate (κ = 0.514). All 8 patients with motor or sensory disorders proved to have meningiomas supplied completely or partially by the internal carotid arteries, while all 14 patients with meningiomas supplied by the external carotid arteries or basilar arteries didn't show any symptoms concerning motor or sensory disorders (p = 0.003). T-ASL could complement unenhanced 3D-TOF-MRA and increase accuracy in the identification of the supplying arteries of meningiomas in a safe, intuitive, non-radioactive manner. The information about feeding arteries was potentially related to patients' symptoms and pathology, making it more crucial for neurosurgeons in planning surgery as well as evaluating prognosis. (orig.)

  19. Evaluation of the applicability of territorial arterial spin labeling in meningiomas for presurgical assessments compared with 3-dimensional time-of-flight magnetic resonance angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yiping; Wen, Jianbo; Geng, Daoying; Yin, Bo [Fudan University, Department of Radiology, Huashan Hospital, Shanghai (China); Luan, Shihai [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai (China); Liu, Li [Fudan University, Department of Radiology, Shanghai Cancer Center, Shanghai (China); Xiong, Ji [Fudan University, Department of Pathology, Huashan Hospital, Shanghai (China); Qu, Jianxun [GE Healthcare, Department of MR Research, Shanghai (China)

    2017-10-15

    To prospectively evaluate the application of territorial arterial spin labelling (t-ASL) in comparison with unenhanced three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) in the identification of the feeding vasculature of meningiomas. Thirty consecutive patients with suspected meningiomas underwent conventional MR imaging, unenhanced 3D-TOF-MRA and t-ASL scanning. Four experienced neuro-radiologists assessed the feeding vessels with different techniques separately. For the identification of the origin of the feeding arteries on t-ASL, the inter-observer agreement was excellent (κ = 0.913), while the inter-observer agreement of 3D-TOF-MRA was good (κ = 0.653). The inter-modality agreement between t-ASL and 3D-TOF-MRA for the feeding arteries was moderate (κ = 0.514). All 8 patients with motor or sensory disorders proved to have meningiomas supplied completely or partially by the internal carotid arteries, while all 14 patients with meningiomas supplied by the external carotid arteries or basilar arteries didn't show any symptoms concerning motor or sensory disorders (p = 0.003). T-ASL could complement unenhanced 3D-TOF-MRA and increase accuracy in the identification of the supplying arteries of meningiomas in a safe, intuitive, non-radioactive manner. The information about feeding arteries was potentially related to patients' symptoms and pathology, making it more crucial for neurosurgeons in planning surgery as well as evaluating prognosis. (orig.)

  20. Evaluation of the degree of arteriovenous shunting in intracranial arteriovenous malformations using pseudo-continuous arterial spin labeling magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sunwoo, Leonard; Park, Sun-Won [Seoul Metropolitan Government - Seoul National University Boramae Medical Center, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Sohn, Chul-Ho; Yun, Tae Jin; Choi, Seung Hong; Cho, Young Dae; Kim, Ji-hoon; Han, Moon Hee [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Lee, Jong Young [Kangdong Sacred Heart Hospital, Department of Neurosurgery, Seoul (Korea, Republic of); Yi, Kyung Sik [Chungbuk National University Hospital, Department of Radiology, Cheongju (Korea, Republic of); Paek, Sun Ha; Kim, Yong Hwy; Kim, Jin Wook; Chung, Hyun-Tai; Kim, Dong Gyu [Seoul National University Hospital, Department of Neurosurgery, Seoul (Korea, Republic of)

    2015-08-15

    Intracranial arteriovenous malformations (AVMs) display venous signals on arterial spin labeling (ASL) magnetic resonance (MR) imaging due to the presence of arteriovenous shunting. Our aim was to quantitatively correlate AVM signal intensity on ASL with the degree of arteriovenous shunting estimated on digital subtraction angiography (DSA) in AVMs. MR imaging including pseudo-continuous ASL at 3 T and DSA were obtained on the same day in 40 patients with intracranial AVMs. Two reviewers assessed the nidus and venous signal intensities on ASL images to determine the presence of arteriovenous shunting. Interobserver agreement on ASL between the reviewers was determined. ASL signal intensity of the AVM lesion was correlated with AVM size and the time difference between normal and AVM venous transit times measured from the DSA images. Interobserver agreement between two reviewers for nidus and venous signal intensities was excellent (κ = 0.80 and 1.0, respectively). Interobserver agreement regarding the presence of arteriovenous shunting was perfect (κ = 1.0). AVM signal intensity showed a positive relationship with the time difference between normal and AVM venous transit times (r = 0.638, P < 0.001). AVM signal intensity also demonstrated a positive relationship with AVM size (r = 0.561, P < 0.001). AVM signal intensity on ASL in patients with AVM correlates well with the degree of early vein opacification on DSA, which corresponds to the degree of arteriovenous shunting. (orig.)

  1. Thyroid perfusion imaging as a diagnostic tool in Graves' disease. Arterial spin labeling magnetic resonance imaging vs. colour-coded Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Muessig, K. [University Hospital of Duesseldorf (Germany). Dept. of Metabolic Diseases; Leibniz Center for Diabetes Research, Duesseldorf (Germany). Inst. for Clinical Diabetology; University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Schraml, C.; Schwenzer, N.F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology; Rietig, R.; Balletshofer, B. [University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Martirosian, P.; Haering, H.U.; Schick, F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; Claussen, C.D. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology

    2012-12-15

    Purpose: Though increased thyroid perfusion assessed by colour-coded Doppler ultrasound (CDUS) is characteristic of Graves' disease (GD), sometimes perfusion assessment by CDUS is not possible. In these cases, arterial spin labelling (ASL), a novel magnetic resonance imaging (MRI) technique allowing non-invasive thyroid perfusion quantification, may have additional diagnostic value. We aimed to evaluate the potential of ASL-MRI for assessment of increased blood perfusion in patients with GD compared to CDUS. Materials and Methods: Thyroid perfusion was measured by CDUS (volume flow rate calculated from pulsed wave Doppler signals and vessel diameter) and ASL-MRI at 1.5 T in 7 patients with GD and 10 healthy controls. Results: In patients with GD, average perfusion in both thyroid lobes was markedly increased compared to controls. Both techniques applied for volume related perfusion as well as absolute volume flow in thyroid feeding vessels provided similar results (all p = 0.0008). Using a cut-off value of 22 ml/min for the volume flow rate assessed by CDUS in the four feeding vessels allowed discrimination between patients with GD and controls in all cases. After adjusting thyroid perfusion for the differences in organ volume, both CDUS and ASL revealed also complete discrimination between health and disease. Conclusion: Thyroid perfusion measurement by ASL-MRI reliably discriminate GD from normal thyroid glands. In patients in whom thyroid arteries cannot be depicted by CDUS for technical or anatomical reasons, ASL-MRI may have additional diagnostic value. (orig.)

  2. Synthesis, characterization and biological evaluation of a well dispersed suspension of gallium-68-labeled magnetic nanosheets of graphene oxide for in vivo coincidence imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fazaeli, Yousef; Feizi, Shahzad [Nuclear Science and Technology Research Institute, Karaj (Iran, Islamic Republic of). Radiation Application Research School; Rahighi, Reza [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of). Dept. of Physics; Tayyebi, Ahmad [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of). Dept. of Engineering

    2017-03-01

    Graphene oxide (GO) nanosheets were hybridized with Fe{sub 3}O{sub 4} nanoparticles (NPs) to form magnetic GO (MGO) and were further labeled by [{sup 68}Ga]GaCl{sub 3} as a potential drug delivery system. Paper chromatography, Fourier transform infra red (FTIR) spectroscopy, low-angle X-ray diffraction (XRD), CHN and atomic force microscopy (AFM) were utilized to characterize the trinary composite ([{sup 68}Ga] rate at MGO). Biological evaluations of the prepared nanocomposite were performed in normal Sprague Dawley rats and it was found to be a possible host for theranostic radiopharmaceuticals. The results showed that the grafting of Fe{sub 3}O{sub 4} NPs on nanocomposite reduced the unwanted liver and spleen uptakes and increased the ratio of kidney/liver uptake from 0.037 to 1.07, leading to the fast removal of radioactive agent and less imposed radiation to patients. The high level of hydrogen bonding caused by the presence of functional groups is responsible for this effect. Considering the accumulation of the tracer in vital organs of rat (especially brain), efficient iron oxide grafting, fast wash-out, the short half-life gallium-68 and less imposed radiation doses to patients, this nanocomposite could be a suitable candidate for positron emission tomography (PET) studies and imaging applications.

  3. An Open-Label Exploratory Study with Memantine: Correlation between Proton Magnetic Resonance Spectroscopy and Cognition in Patients with Mild to Moderate Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Marc L. Gordon

    2012-08-01

    Full Text Available Aim: To characterize progression of Alzheimer’s disease (AD using proton magnetic resonance spectroscopy (1H MRS. Methods: Eleven subjects with mild to moderate AD underwent neurocognitive testing and single-voxel 1H MRS from the precuneus and posterior cingulate region at baseline, after 24 weeks of monotherapy with a cholinesterase inhibitor, and after another 24 weeks of combination therapy with open-label memantine and a cholinesterase inhibitor. Baseline metabolites [N-acetylaspartate (NAA, myo-inositol (mI, choline (Cho, and creatine (Cr] and their ratios in AD subjects were compared with those of an age-matched control group of 28 cognitively normal subjects. Results: AD subjects had significantly higher mI/Cr and lower NAA, NAA/Cr, NAA/Cho, and NAA/mI. Baseline Alzheimer’s Disease Cooperative Study Activities of Daily Living (ADCS-ADL scores significantly correlated with NAA/Cr, mI/Cr, and NAA/mI. There was an increase in mI and a decrease in NAA/mI, but no significant change in other metabolites or ratios, or neurocognitive measures, when memantine was added to a cholinesterase inhibitor. Conclusion: Metabolite ratios significantly differed between AD and control subjects. Baseline metabolite ratios correlated with function (ADCS-ADL. There was an increase in mI and a decrease in NAA/mI, but no changes in other metabolites, ratios, or cognitive measures, when memantine was added to a cholinesterase inhibitor.

  4. Synthesis, characterization and biological evaluation of a well dispersed suspension of gallium-68-labeled magnetic nanosheets of graphene oxide for in vivo coincidence imaging

    International Nuclear Information System (INIS)

    Fazaeli, Yousef; Feizi, Shahzad; Rahighi, Reza; Tayyebi, Ahmad

    2017-01-01

    Graphene oxide (GO) nanosheets were hybridized with Fe_3O_4 nanoparticles (NPs) to form magnetic GO (MGO) and were further labeled by ["6"8Ga]GaCl_3 as a potential drug delivery system. Paper chromatography, Fourier transform infra red (FTIR) spectroscopy, low-angle X-ray diffraction (XRD), CHN and atomic force microscopy (AFM) were utilized to characterize the trinary composite (["6"8Ga] rate at MGO). Biological evaluations of the prepared nanocomposite were performed in normal Sprague Dawley rats and it was found to be a possible host for theranostic radiopharmaceuticals. The results showed that the grafting of Fe_3O_4 NPs on nanocomposite reduced the unwanted liver and spleen uptakes and increased the ratio of kidney/liver uptake from 0.037 to 1.07, leading to the fast removal of radioactive agent and less imposed radiation to patients. The high level of hydrogen bonding caused by the presence of functional groups is responsible for this effect. Considering the accumulation of the tracer in vital organs of rat (especially brain), efficient iron oxide grafting, fast wash-out, the short half-life gallium-68 and less imposed radiation doses to patients, this nanocomposite could be a suitable candidate for positron emission tomography (PET) studies and imaging applications.

  5. Benefits of PEGylation in the early post-transplant period of intraportal islet transplantation as assessed by magnetic resonance imaging of labeled islets.

    Science.gov (United States)

    Jin, Sang-Man; Oh, Seung-Hoon; Oh, Bae Jun; Suh, Sunghwan; Bae, Ji Cheol; Lee, Jung Hee; Lee, Myung-Shik; Lee, Moon-Kyu; Kim, Kwang-Won; Kim, Jae Hyeon

    2014-01-01

    While a few studies have demonstrated the benefit of PEGylation in islet transplantation, most have employed renal subcapsular models and none have performed direct comparisons of islet mass in intraportal islet transplantation using islet magnetic resonance imaging (MRI). In this study, our aim was to demonstrate the benefit of PEGylation in the early post-transplant period of intraportal islet transplantation with a novel algorithm for islet MRI. Islets were PEGylated after ferucarbotran labeling in a rat syngeneic intraportal islet transplantation model followed by comparisons of post-transplant glycemic levels in recipient rats infused with PEGylated (n = 12) and non-PEGylated (n = 13) islets. The total area of hypointense spots and the number of hypointense spots larger than 1.758 mm(2) of PEGylated and non-PEGylated islets were quantitatively compared. The total area of hypointense spots (P islet group 7 and 14 days post translation (DPT). These results translated into better post-transplant outcomes in the PEGylated islet group 28 DPT. In validation experiments, MRI parameters obtained 1, 7, and 14 DPT predicted normoglycemia 4 wk post-transplantation. We directly demonstrated the benefit of islet PEGylation in protection against nonspecific islet destruction in the early post-transplant period of intraportal islet transplantation using a novel algorithm for islet MRI. This novel algorithm could serve as a useful tool to demonstrate such benefit in future clinical trials of islet transplantation using PEGylated islets.

  6. Magnetic resonance imaging in children presenting migraine with aura: Association of hypoperfusion detected by arterial spin labelling and vasospasm on MR angiography findings.

    Science.gov (United States)

    Cadiot, Domitille; Longuet, Romain; Bruneau, Bertrand; Treguier, Catherine; Carsin-Vu, Aline; Corouge, Isabelle; Gomes, Constantin; Proisy, Maïa

    2018-04-01

    Objective A child presenting with a first attack of migraine with aura usually undergoes magnetic resonance imaging (MRI) to rule out stroke. The purpose of this study was to report vascular and brain perfusion findings in children suffering from migraine with aura on time-of-flight MR angiography (TOF-MRA) and MR perfusion imaging using arterial spin labelling (ASL). Methods We retrospectively included all children who had undergone an emergency MRI examination with ASL and TOF-MRA sequences for acute neurological deficit and were given a final diagnosis of migraine with aura. The ASL perfusion maps and TOF-MRA images were independently assessed by reviewers blinded to clinical data. A mean cerebral blood flow (CBF) value was obtained for each cerebral lobe after automatic data post-processing. Results Seventeen children were finally included. Hypoperfusion was identified in one or more cerebral lobes on ASL perfusion maps by visual assessment in 16/17 (94%) children. Vasospasm was noted within the intracranial vasculature on the TOF-MRA images in 12/17 (71%) children. All (100%) of the abnormal TOF-MRA images were associated with homolateral hypoperfusion. Mean CBF values were significantly lower ( P < 0.05) in visually hypoperfused lobes than in normally perfused lobes. Conclusion ASL and TOF-MRA are two totally non-invasive, easy-to-use MRI sequences for children in emergency settings. Hypoperfusion associated with homolateral vasospasm may suggest a diagnosis of migraine with aura.

  7. Comparison of Tc-99m labeled liver and liver pate as markers for solid-phase gastric emptying

    International Nuclear Information System (INIS)

    Christian, P.E.; Moore, J.G.; Datz, F.L.

    1984-01-01

    A radionuclide marker for studies of solid-phase gastric emptying should have a high labeling efficiency and remain relatively stable during gastric emptying. The availability of materials and the ease of preparation are also considerations in selecting radionuclide markers. The stability of intracellularly labeled chicken liver, surface-labeled chicken liver, and labeled pureed meat (liver pate) incubated with hydrochloric acid solution or gastric juice have been compared. Intracellularly labeled chicken liver and labeled liver pate were also compared in gastric emptying studies in humans. In vitro results demonstrated labeling efficiencies greater than 92% for both intracellularly labeled liver and labeled liver pate. The pate labeled with Tc-99m sulfur colloid was more stable than Tc-99m surface-labeled liver in vitro and its prepartion was easier than with the intracellular labeling technique. Gastric emptying studies on normal subjects demonstrated equal performance of the intracellularly labeled liver and the labeled liver pate. Labeled liver pate is thus an alternative to intracellularly labeled chicken liver in measuring solid-phase gastric emptying

  8. Intracellular bimodal nanoparticles based on quantum dots for high-field MRI at 21.1 T.

    Science.gov (United States)

    Rosenberg, Jens T; Kogot, Joshua M; Lovingood, Derek D; Strouse, Geoffrey F; Grant, Samuel C

    2010-09-01

    Multimodal, biocompatible contrast agents for high magnetic field applications represent a new class of nanomaterials with significant potential for tracking of fluorescence and MR in vitro and vivo. Optimized for high-field MR applications-including biomedical imaging at 21.1 T, the highest magnetic field available for MRI-these nanoparticles capitalize on the improved performance of chelated Dy(3+) with increasing magnetic field coupled to a noncytotoxic Indium Phosphide/Zinc Sulfide (InP/ZnS) quantum dot that provides fluorescence detection, MR responsiveness, and payload delivery. By surface modifying the quantum dot with a cell-penetrating peptide sequence coupled to an MR contrast agent, the bimodal nanomaterial functions as a self-transfecting high-field MR/optical contrast agent for nonspecific intracellular labeling. Fluorescent images confirm sequestration in perinuclear vesicles of labeled cells, with no apparent cytotoxicity. These techniques can be extended to impart cell selectivity or act as a delivery vehicle for genetic or pharmaceutical interventions. 2010 Wiley-Liss, Inc.

  9. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  10. Nutrition Labeling

    DEFF Research Database (Denmark)

    Grunert, Klaus G

    2013-01-01

    because consumers will avoid products that the label shows to be nutritionally deficient, but also because food producers will try to avoid marketing products that appear, according to the label, as nutritionally problematic, for example, because of a high content of saturated fat or salt. Nutrition......Nutrition labeling refers to the provision of information on a food product’s nutritional content on the package label. It can serve both public health and commercial purposes. From a public health perspective, the aim of nutrition labeling is to provide information that can enable consumers...... to make healthier choices when choosing food products. Nutrition labeling is thus closely linked to the notion of the informed consumer, that chooses products according to their aims, on the basis of the information at their disposal. Because many consumers are assumed to be interested in making healthy...

  11. Private Labels

    OpenAIRE

    Kolmačková, Zuzana

    2013-01-01

    This Bachelor Thesis titled Private labels deals with distribution strategy based on the introduction of private labels especially in retail chains. At the beginning it is focused on the general concept of private label offered by retailers, where is mentioned basic characteristics, history and structuring of distribution brands. Subsequently this thesis informs readers about the introduction of new special distribution brands, which focus primarily on the new consumption habits of customers....

  12. Stochastic models of intracellular transport

    KAUST Repository

    Bressloff, Paul C.; Newby, Jay M.

    2013-01-01

    mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually

  13. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  14. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  15. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  16. Sustainability Labeling

    NARCIS (Netherlands)

    Dam, van Y.K.

    2017-01-01

    Sustainability labeling originated from a need to protect the identity of alternative systems of food production and to increase market transparency. From the 1980s onwards sustainability labeling has changed into a policy instrument replacing direct government regulation of the food market, and a

  17. LIPID SYNTHESIS, INTRACELLULAR TRANSPORT, AND SECRETION

    Science.gov (United States)

    Stein, Olga; Stein, Yechezkiel

    1967-01-01

    In the mammary glands of lactating albino mice injected intravenously with 9, 10-oleic acid-3H or 9, 10-palmitic acid-3H, it has been shown that the labeled fatty acids are incorporated into mammary gland glycerides. The labeled lipid in the mammary gland 1 min after injection was in esterified form (> 95%), and the radioautographic reaction was seen over the rough endoplasmic reticulum and over lipid droplets, both intracellular and intraluminal. At 10–60 min after injection, the silver grains were concentrated predominantly over lipid droplets. There was no concentration of radioactivity over the granules in the Golgi apparatus, at any time interval studied. These findings were interpreted to indicate that after esterification of the fatty acid into glycerides in the rough endoplasmic reticulum an in situ aggregation of lipid occurs, with acquisition of droplet form. The release of the lipid into the lumen proceeds directly and not through the Golgi apparatus, in contradistinction to the mode of secretion of casein in the mammary gland or of lipoprotein in the liver. The presence of strands of endoplasmic reticulum attached to intraluminal lipid droplets provides a structural counterpart to the milk microsomes described in ruminant milk. PMID:6033535

  18. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  19. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  20. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  1. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  2. Insecticide resistance and intracellular proteases.

    Science.gov (United States)

    Wilkins, Richard M

    2017-12-01

    Pesticide resistance is an example of evolution in action with mechanisms of resistance arising from mutations or increased expression of intrinsic genes. Intracellular proteases have a key role in maintaining healthy cells and in responding to stressors such as pesticides. Insecticide-resistant insects have constitutively elevated intracellular protease activity compared to corresponding susceptible strains. This increase was shown for some cases originally through biochemical enzyme studies and subsequently putatively by transcriptomics and proteomics methods. Upregulation and expression of proteases have been characterised in resistant strains of some insect species, including mosquitoes. This increase in proteolysis results in more degradation products (amino acids) of intracellular proteins. These may be utilised in the resistant strain to better protect the cell from stress. There are changes in insect intracellular proteases shortly after insecticide exposure, suggesting a role in stress response. The use of protease and proteasome inhibitors or peptide mimetics as synergists with improved application techniques and through protease gene knockdown using RNA interference (possibly expressed in crop plants) may be potential pest management strategies, in situations where elevated intracellular proteases are relevant. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Assessments of proliferation capacity and viability of New Zealand rabbit peripheral blood endothelial progenitor cells labeled with superparamagnetic particles.

    Science.gov (United States)

    Mai, Xiao-Li; Ma, Zhan-Long; Sun, Jun-Hui; Ju, Sheng-Hong; Ma, Ming; Teng, Gao-Jun

    2009-01-01

    Magnetic resonance imaging (MRI) has proven to be effective in tracking the distribution of transplanted stem cells to target organs by way of labeling cells with superparamagnetic iron oxide particles (SPIO). However, the effect of SPIO upon labeled cells is still unclear on a cellular level. With this study, the proliferation and viability of New Zealand rabbit peripheral blood endothelial progenitor cells (EPCs) labeled with SPIO were evaluated and in vitro images were obtained using a 1.5 T MR scanner. Mononuclear cells (MNCs) were isolated from peripheral blood of the adult New Zealand rabbit and cultured in fibronectin-coated culture flasks, in which EPCs were identified from cell morphology, outgrowth characteristics, and internalization of DiI-Ac-LDL and binding to FITC-UEA I. EPCs were incubated with the self-synthesized poly-L-lysine-conjugated SPIO (PLL-SPIO) particles in a range of concentrations. The prevalence of iron-containing vesicles or endosomes in the cytoplasm of labeled cells was confirmed with Prussian blue staining and transmission electron microscopy. Tetrazolium salt (MTT) assay, cell apoptosis, and cycle detection were assessed to evaluate proliferation and function of various concentrations, magnetically labeled EPCs. The quantity of iron per cell was determined by atomic absorption spectrometry. The cells underwent MRI with different sequences. The result showed that rabbit EPCs were efficiently labeled with the home synthesized PLL-SPIO. There was found to be no statistically significant difference in the MTT values of light absorption measured on the third and fifth days. Between labeled and unlabeled cells, there were also no aberrations found in the cell cycles, apoptosis, or growth curves. The atomic absorption spectrophotometer showed that the intracellular content of Fe decreased as more time elapsed after labeling. The labeled EPCs demonstrated a loss of MRI signal intensity (SI) when compared with the SI of unlabeled cells

  4. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  5. Pesticide Labels

    Science.gov (United States)

    Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human health and the environment.

  6. Labelling patients

    International Nuclear Information System (INIS)

    Strudwick, R.M.

    2016-01-01

    This article looks at how diagnostic radiographers label their patients. An ethnographic study of the workplace culture in one diagnostic imaging department was undertaken using participant observation for four months and semi-structured interviews with ten key informants. One of the key themes; the way in which radiographers label their patients, is explored in this article. It was found from the study that within the department studied the diagnostic radiographers labelled or categorised their patients based on the information that they had. This information is used to form judgements and these judgements were used to assist the radiographers in dealing with the many different people that they encountered in their work. This categorisation and labelling of the patient appears to assist the radiographer in their decision-making processes about the examination to be carried out and the patient they are to image. This is an important aspect of the role of the diagnostic radiographer. - Highlights: • I have studied the culture in one imaging department. • Radiographers label or categorise their patients. • These labels/categories are used to manage the patient. • This is an important aspect of the way in which radiographers work.

  7. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  8. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  9. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  10. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  11. Long-term MRI tracking of dual-labeled adipose-derived stem cells homing into mouse carotid artery injury

    Directory of Open Access Journals (Sweden)

    Qin JB

    2012-10-01

    Full Text Available Jin-Bao Qin,1,5,* Kang-An Li,2,* Xiang-Xiang Li,1,5 Qing-Song Xie,3 Jia-Ying Lin,4 Kai-Chuang Ye,1,5 Mi-Er Jiang,1,5 Gui-Xiang Zhang,2 Xin-Wu Lu1,51Department of Vascular Surgery, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University, School of Medicine, 2Department of Radiology, Shanghai First People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 3Department of Neurosurgery, Cixi Municipal People's Hospital, Zhejiang Province, China; 4Clinic for Gynecology, Charite-Universitatsmedizin Berlin, Berlin, Germany; 5Vascular Center, Shanghai Jiao Tong University, Shanghai, China*These two authors contributed equally to this workBackground: Stem cell therapy has shown great promise for regenerative repair of injured or diseased tissues. Adipose-derived stem cells (ADSCs have become increasingly attractive candidates for cellular therapy. Magnetic resonance imaging has been proven to be effective in tracking magnetic-labeled cells and evaluating their clinical relevance after cell transplantation. This study investigated the feasibility of imaging green fluorescent protein-expressing ADSCs (GFP-ADSCs labeled with superparamagnetic iron oxide particles, and tracked them in vivo with noninvasive magnetic resonance imaging after cell transplantation in a model of mouse carotid artery injury.Methods: GFP-ADSCs were isolated from the adipose tissues of GFP mice and labeled with superparamagnetic iron oxide particles. Intracellular stability, proliferation, and viability of the labeled cells were evaluated in vitro. Next, the cells were transplanted into a mouse carotid artery injury model. Clinical 3 T magnetic resonance imaging was performed immediately before and 1, 3, 7, 14, 21, and 30 days after cell transplantation. Prussian blue staining and histological analysis were performed 7 and 30 days after transplantation.Results: GFP-ADSCs were found to be efficiently labeled with superparamagnetic iron oxide

  12. The sandwich-type electrochemiluminescence immunosensor for {alpha}-fetoprotein based on enrichment by Fe{sub 3}O{sub 4}-Au magnetic nano probes and signal amplification by CdS-Au composite nanoparticles labeled anti-AFP

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Hankun [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo 315211 (China); Gan Ning, E-mail: ganning@nbu.edu.cn [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo 315211 (China); Li Tianhua; Cao Yuting; Zeng Saolin [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo 315211 (China); Zheng Lei, E-mail: nfyyzl@163.com [Department of Laboratory Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Guo Zhiyong [State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo 315211 (China)

    2012-10-09

    Highlights: Black-Right-Pointing-Pointer Sandwich immunoreaction, testing a large number of samples simultaneously. Black-Right-Pointing-Pointer The magnetic separation and enrichment by Fe{sub 3}O{sub 4}-Au magnetic nano probes. Black-Right-Pointing-Pointer The amplification of detection signal by CdS-Au composite nanoparticles labeled anti-AFP. Black-Right-Pointing-Pointer Almost no background signal, which greatly improve the sensitivity of detection. - Abstract: A novel and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor was fabricated on a glassy carbon electrode (GCE) for ultra trace levels of {alpha}-fetoprotein (AFP) based on sandwich immunoreaction strategy by enrichment using magnetic capture probes and quantum dots coated with Au shell (CdS-Au) as the signal tag. The capture probe was prepared by immobilizing the primary antibody of AFP (Ab1) on the core/shell Fe{sub 3}O{sub 4}-Au nanoparticles, which was first employed to capture AFP antigens to form Fe{sub 3}O{sub 4}-Au/Ab1/AFP complex from the serum after incubation. The product can be separated from the background solution through the magnetic separation. Then the CdS-Au labeled secondary antibody (Ab2) as signal tag (CdS-Au/Ab2) was conjugated successfully with Fe{sub 3}O{sub 4}-Au/Ab1/AFP complex to form a sandwich-type immunocomplex (Fe{sub 3}O{sub 4}-Au/Ab1/AFP/Ab2/CdS-Au), which can be further separated by an external magnetic field and produce ECL signals at a fixed voltage. The signal was proportional to a certain concentration range of AFP for quantification. Thus, an easy-to-use immunosensor with magnetic probes and a quantum dots signal tag was obtained. The immunosensor performed at a level of high sensitivity and a broad concentration range for AFP between 0.0005 and 5.0 ng mL{sup -1} with a detection limit of 0.2 pg mL{sup -1}. The use of magnetic probes was combined with pre-concentration and separation for trace levels of tumor markers in the serum. Due to the

  13. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  14. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  15. Fluorescein isothiocyanate labeled, magnetic nanoparticles conjugated D-penicillamine-anti-metadherin and in vitro evaluation on breast cancer cells; Avaliacao do isotiocianato de fluoresceina marcado, das nanoparticulas magneticas conjugadas da D-penicilamina antimetaderina e in vitro nas celulas do cancer de mama

    Energy Technology Data Exchange (ETDEWEB)

    Akca, Ozlet; Unak, Perihan; Medine, E. Ylker [Ege University (Turkey). Institute of Nuclear Sciences. Department of Nuclear Applications; Sakarya, Serhan [Adnan Menderes University (Turkey). ADUBILTEM Science and Technology Research and Development Center; Ozdemir, Caglar; Timur, Suna [Ege University (Turkey). Science Faculty. Department of Nuclear Applications

    2011-07-01

    Silane modified magnetic nanoparticles were prepared after capped with silica generated from the hydrolyzation of tetraethyl orthosilicate (TEOS). Amino silane (SG-Si900) was added to this solution for surface modification of silica coated magnetic particles. Finally, D-penicillamine (D-PA)-antimetadherin (anti-MTDH) was covalently linked to the amine group using glutaraldehyde as cross-linker. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and atomic force microscopy (AFM). AFM results showed that particles are nearly monodisperse, and the average size of particles was 40 to 50 nm. An amino acid derivative D-PA was conjugated anti-MTDH, which results the increase of uptaking potential of a conjugated agent, labelled fluorescein isothiocyanate (FITC) and then conjugated to the magnetic nanoparticles. In vitro evaluation of the conjugated D-PA-anti-MTDH-FITC to magnetic nanoparticle was studied on MCF-7 breast cancer cell lines. Fluorescence microscopy images of cells after incubation of the sample were obtained to monitor the interaction of the sample with the cancerous cells. Incorporation on cells of FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH was found higher than FITC labeled D-PA-anti-MTDH. The results show that magnetic properties and application of magnetic field increased incorporation rates. The obtained D-PA-anti-MTDH-magnetic nanoparticles-FITC complex has been used for in vitro imaging of breast cancer cells. FITC labeled and magnetic nanoparticles conjugated D-PA-anti-MTDH may be useful as a new class of scintigraphic agents. Results of this study are sufficiently encouraging to bring about further evaluation of this and related compounds for ultraviolet magnetic resonance (UV-MR) dual imaging. (author)

  16. Stochastic models of intracellular transport

    KAUST Repository

    Bressloff, Paul C.

    2013-01-09

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures. © 2013 American Physical Society.

  17. Characterization of Leptin Intracellular Trafficking

    Directory of Open Access Journals (Sweden)

    E Walum

    2009-12-01

    Full Text Available Leptin is produced by adipose tissue, and its concentration in plasma is related to the amount of fat in the body. The leptin receptor (OBR is a member of the class I cytokine receptor family and several different isoforms, produced by alternative mRNA splicing are found in many tissues, including the hypothalamus. The two predominant isoforms includes a long form (OBRl with an intracellular domain of 303 amino acids and a shorter form (OBRs with an intracellular domain of 34 amino acids. Since OBRl is mainly expressed in the hypotalamus, it has been suggested to be the main signalling form. The peripheral production of leptin by adipocyte tissue and its effects as a signal of satiety in the central nervous system imply that leptin gains access to regions of the brain regulating in energy balance by crossing the blood-brain barrier. In an attempt to characterize the intracellular transport of leptin, we have followed binding internalization and degradation of leptin in HEK293 cells. We have also monitored the intracellular transport pathway of fluorescent conjugated leptin in HEK293 cells. Phenylarsine oxide, a general inhibitor of endocytosis, as well as incubation at mild hypertonic conditions, prevented the uptake of leptin, confirming a receptor-mediated internalization process. When internalized, 125I-leptin was rapidly accumulated inside the cells and reached a maximum after 10 min. After 70 minutes about 40-50% of total counts in each time point were found in the medium as TCA-soluble material. Leptin sorting, at the level of early endosomes, did not seem to involve recycling endosomes, since FITC-leptin was sorted from Cy3- transferrin containing compartments at 37°C. At 45 minutes of continuos internalization, FITC-leptin appeared mainly accumulated in late endocytic structures colocalizing with internalized rhodamine coupled epidermial growth factor (EGF and the lysosomal marker protein lamp-1. The transport of leptin was also shown

  18. Light irradiation helps magnetotactic bacteria eliminate intracellular reactive oxygen species.

    Science.gov (United States)

    Li, Kefeng; Wang, Pingping; Chen, Chuanfang; Chen, Changyou; Li, Lulu; Song, Tao

    2017-09-01

    Magnetotactic bacteria (MTB) demonstrate photoresponse. However, little is known about the biological significance of this behaviour. Magnetosomes exhibit peroxidase-like activity and can scavenge reactive oxygen species (ROS). Magnetosomes extracted from the Magnetospirillum magneticum strain AMB-1 show enhanced peroxidase-like activity under illumination. The present study investigated the effects of light irradiation on nonmagnetic (without magnetosomes) and magnetic (with magnetosomes) AMB-1 cells. Results showed that light irradiation did not affect the growth of nonmagnetic and magnetic cells but significantly increased magnetosome synthesis and reduced intracellular ROS level in magnetic cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to analyse the expression level of magnetosome formation-associated genes (mamA, mms6, mms13 and mmsF) and stress-related genes (recA, oxyR, SOD, amb0664 and amb2684). Results showed that light irradiation upregulated the expression of mms6, mms13 and mmsF. Furthermore, light irradiation upregulated the expression of stress-related genes in nonmagnetic cells but downregulated them in magnetic cells. Additionally, magnetic cells exhibited stronger phototactic behaviour than nonmagnetic ones. These results suggested that light irradiation could heighten the ability of MTB to eliminate intracellular ROS and help them adapt to lighted environments. This phenomenon may be related to the enhanced peroxidase-like activity of magnetosomes under light irradiation. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  19. Intracellular PHB conversion in a type II methanotroph studied by 13 C NMR

    NARCIS (Netherlands)

    Vecherskaya, M.; Dijkema, C.; Stams, A.J.M.

    2001-01-01

    Poly-g-hydroxybutyrate (PHB) formation under aerobic conditions via incorporation of [13C-2]acetate as a cosubstrate and its intracellular degradation under anaerobic conditions in a Type II methanotroph was studied by 13C NMR. During PHB synthesis in the presence of labelled acetate, low levels of

  20. Influence of intracellular acidosis on contractile function in the working rat heart

    International Nuclear Information System (INIS)

    Jeffrey, F.M.H.; Malloy, C.R.; Radda, G.K.

    1987-01-01

    The decrease in myocardial contractility during ischemia, hypoxia, and extracellular acidosis has been attributed to intracellular acidosis. Previous studies of the relationship between pH and contractile state have utilized respiratory or metabolic acidosis to alter intracellular pH. The authors developed a model in the working perfused rat heart to study the effects of intracellular acidosis with normal external pH and optimal O 2 delivery. Intracellular pH and high-energy phosphates were monitored by 31 P nuclear magnetic resonance spectroscopy. Hearts were perfused to a steady state with a medium containing 10 mM NH 4 Cl. Acidosis induced a substantial decrease in aortic flow and stroke volume which was associated with little change in peak systolic pressure. It was concluded that (1) for the same intracellular acidosis the influence on tension development was more pronounced with a combined extra- and intracellular acidosis than with an isolated intracellular acidosis, and (2) stroke volume at constant preload was impaired by intracellular acidosis even though changes in developed pressure were minimal. These observations suggest that isolated intracellular acidosis has adverse effects on diastolic compliance and/or relaxation

  1. Magnetic

    Science.gov (United States)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  2. MAGNET

    CERN Multimedia

    Benoit Curé

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  3. MAGNET

    CERN Document Server

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  4. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  5. Subcellular site and nature of intracellular cadmium in plants

    International Nuclear Information System (INIS)

    Wagner, G.J.

    1979-01-01

    The mechanisms underlying heavy metal accumulation, toxicity and tolerance in higher plants are poorly understood. Since subcellular processes are undoubtedly involved in all these phenomena, it is of interest to study the extent of, subcellular site of and nature of intracellularly accumulated cadmium in higher plants. Whole plants supplied 109 CdCl 2 or 112 CdSO 4 accumulated Cd into roots and aerial tissues. Preparation of protoplasts from aerial tissue followed by subcellular fractionation of the protoplasts to obtain intact vacuoles, chloroplasts and cytosol revealed the presence of Cd in the cytosol but not in vacuoles or chloroplasts. Particulate materials containing other cell components were also labeled. Of the 109 Cd supplied to plants, 2 to 10% was recovered in both cytosol preparations and in particulate materials. Cytosol contained proteinaceous--Cd complexes, free metal and low molecular weight Cd complexes. Labeling of protoplasts gave similar results. No evidence was obtained for the production of volatile Cd complexes in tobacco

  6. Food labels

    DEFF Research Database (Denmark)

    Selsøe Sørensen, Henrik; Clement, Jesper; Gabrielsen, Gorm

    2012-01-01

    evidence for dividing consumers into two profiles: one relying on general food knowledge and another using knowledge related to signpost labels. In a combined eyetracking and questionnaire survey we analyse the influence of background knowledge and identify different patterns of visual attention......The food industry develops tasty and healthy food but fails to deliver the message to all consumers. The consumers’ background knowledge is essential for how they find and decode relevant elements in the cocktail of signs which fight for attention on food labels. In this exploratory study, we find...... for the two consumer profiles. This underlines the complexity in choosing and designing the ‘right’ elements for a food package that consumers actually look at and are able to make rational use of. In spite of any regulation of food information provided by authorities, consumers will still be confronted...

  7. The sandwich-type electrochemiluminescence immunosensor for α-fetoprotein based on enrichment by Fe3O4-Au magnetic nano probes and signal amplification by CdS-Au composite nanoparticles labeled anti-AFP.

    Science.gov (United States)

    Zhou, Hankun; Gan, Ning; Li, Tianhua; Cao, Yuting; Zeng, Saolin; Zheng, Lei; Guo, Zhiyong

    2012-10-09

    A novel and sensitive sandwich-type electrochemiluminescence (ECL) immunosensor was fabricated on a glassy carbon electrode (GCE) for ultra trace levels of α-fetoprotein (AFP) based on sandwich immunoreaction strategy by enrichment using magnetic capture probes and quantum dots coated with Au shell (CdS-Au) as the signal tag. The capture probe was prepared by immobilizing the primary antibody of AFP (Ab1) on the core/shell Fe(3)O(4)-Au nanoparticles, which was first employed to capture AFP antigens to form Fe(3)O(4)-Au/Ab1/AFP complex from the serum after incubation. The product can be separated from the background solution through the magnetic separation. Then the CdS-Au labeled secondary antibody (Ab2) as signal tag (CdS-Au/Ab2) was conjugated successfully with Fe(3)O(4)-Au/Ab1/AFP complex to form a sandwich-type immunocomplex (Fe(3)O(4)-Au/Ab1/AFP/Ab2/CdS-Au), which can be further separated by an external magnetic field and produce ECL signals at a fixed voltage. The signal was proportional to a certain concentration range of AFP for quantification. Thus, an easy-to-use immunosensor with magnetic probes and a quantum dots signal tag was obtained. The immunosensor performed at a level of high sensitivity and a broad concentration range for AFP between 0.0005 and 5.0 ng mL(-1) with a detection limit of 0.2 pg mL(-1). The use of magnetic probes was combined with pre-concentration and separation for trace levels of tumor markers in the serum. Due to the amplification of the signal tag, the immunosensor is highly sensitive, which can offer great promise for rapid, simple, selective and cost-effective detection of effective biomonitoring for clinical application. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Electron Microscopy of Intracellular Protozoa

    Science.gov (United States)

    1988-12-20

    Classification) " ELECTRON MICROSCOPY OF INTRACELLULAR PROTOZOA 12. PERSONAL AUTHOR(S) Aikawa, Masamichi 13a. TYPE OF REPORT I13b. TIME COVERED 114...authors suggest that anti-CS protein antibody is important in reducing the prevalence of malaria with increasing age among persons in such areas and... Hygine 33, 220-226. 0Giudice, G.D., Engers, H.D., Tougne, C., Biro, S.S., Weiss, N., Verdini, A.S., Pessi, A., Degremont, A.A., Freyvogel, T.A., Lambert

  9. Pathogenic mechanisms of intracellular bacteria.

    Science.gov (United States)

    Niller, Hans Helmut; Masa, Roland; Venkei, Annamária; Mészáros, Sándor; Minarovits, Janos

    2017-06-01

    We wished to overview recent data on a subset of epigenetic changes elicited by intracellular bacteria in human cells. Reprogramming the gene expression pattern of various host cells may facilitate bacterial growth, survival, and spread. DNA-(cytosine C5)-methyltransferases of Mycoplasma hyorhinis targeting cytosine-phosphate-guanine (CpG) dinucleotides and a Mycobacterium tuberculosis methyltransferase targeting non-CpG sites methylated the host cell DNA and altered the pattern of gene expression. Gene silencing by CpG methylation and histone deacetylation, mediated by cellular enzymes, also occurred in M. tuberculosis-infected macrophages. M. tuberculosis elicited cell type-specific epigenetic changes: it caused increased DNA methylation in macrophages, but induced demethylation, deposition of euchromatic histone marks and activation of immune-related genes in dendritic cells. A secreted transposase of Acinetobacter baumannii silenced a cellular gene, whereas Mycobacterium leprae altered the epigenotype, phenotype, and fate of infected Schwann cells. The 'keystone pathogen' oral bacterium Porphyromonas gingivalis induced local DNA methylation and increased the level of histone acetylation in host cells. These epigenetic changes at the biofilm-gingiva interface may contribute to the development of periodontitis. Epigenetic regulators produced by intracellular bacteria alter the epigenotype and gene expression pattern of host cells and play an important role in pathogenesis.

  10. Label triangulation

    International Nuclear Information System (INIS)

    May, R.P.

    1983-01-01

    Label Triangulation (LT) with neutrons allows the investigation of the quaternary structure of biological multicomponent complexes under native conditions. Provided that the complex can be fully separated into and reconstituted from its single - protonated and deuterated - components, small angle neutron scattering (SANS) can give selective information on shapes and pair distances of these components. Following basic geometrical rules, the spatial arrangement of the components can be reconstructed from these data. LT has so far been successfully applied to the small and large ribosomal subunits and the transcriptase of E. coli. (author)

  11. A Simple Picaxe Microcontroller Pulse Source for Juxtacellular Neuronal Labelling.

    Science.gov (United States)

    Verberne, Anthony J M

    2016-10-19

    Juxtacellular neuronal labelling is a method which allows neurophysiologists to fill physiologically-identified neurons with small positively-charged marker molecules. Labelled neurons are identified by histochemical processing of brain sections along with immunohistochemical identification of neuropeptides, neurotransmitters, neurotransmitter transporters or biosynthetic enzymes. A microcontroller-based pulser circuit and associated BASIC software script is described for incorporation into the design of a commercially-available intracellular electrometer for use in juxtacellular neuronal labelling. Printed circuit board construction has been used for reliability and reproducibility. The current design obviates the need for a separate digital pulse source and simplifies the juxtacellular neuronal labelling procedure.

  12. Design and preliminary assessment of 99mTc-labeled ultrasmall superparamagnetic iron oxide-conjugated bevacizumab for single photon emission computed tomography/magnetic resonance imaging of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Yanzhao Zhao; Hui Tan; Bing Wu; Pengcheng Hu; Pengyue Wu; Yushen Gu; Dengfeng Cheng; Hongcheng Shi; Qi Yao; Chunfu Zhang

    2014-01-01

    Hepatocellular carcinoma (HCC) has a very high incidence and mortality. Early diagnosis and timely treatments are therefore required to improve the quality of life and survival rate of HCC patients. Here, we developed a vascular endothelial growth factor (VEGF)-based multimodality imaging agent for single photon emission computed tomography (SPECT), computed tomography (CT) and magnetic resonance imaging (MRI) and used it to assess HCC mice and explore the combinative value of CT/MRI-based morphological imaging and SPECT functional imaging. HCC targeting with 125 I-labeled bevacizumab monoclonal antibody (mAb) was examined using SPECT/CT in HepG2 tumor-bearing mice after intravenous mAb injection. Based on this, an integrated, bimodal, VEGF-targeted, ultrasmall superparamagnetic iron oxide (USPIO)-conjugated 99m Tc-labeled bevacizumab mAb was synthesized to increase tumor penetration and accumulations. The in vivo pharmacokinetics and HepG2 tumor targeting were explored through in vivo planar imaging and SPECT/CT using a mouse model of HepG2 liver cancer. The specificity of the radiolabeled nanoparticles for HepG2 HCC was verified using in vitro immunohistochemistry and Prussian blue staining. With diethylenetriamine pentaacetic acid as a bifunctional chelating agent, USPIO-bevacizumab achieved a 99m Tc labeling efficiency of >90 %. The in vivo imaging results also exhibited the targeting of USPIO on HepG2 HCC. The specificity of these results was confirmed using in vitro immunohistochemistry and Prussian blue staining. Our preliminary findings showed the potential of USPIO as an imaging agent for the SPECT/MRI of HepG2 HCC. (author)

  13. Core–shell Fe{sub 3}O{sub 4}–Au magnetic nanoparticles based nonenzymatic ultrasensitive electrochemiluminescence immunosensor using quantum dots functionalized graphene sheet as labels

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Weiyan; Zhang, Yan [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Ge, Shenguang [Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials, University of Jinan, Jinan 250022 (China); Song, Xianrang [Cancer Research Center, Shandong Tumor Hospital, Jinan 250012 (China); Huang, Jiadong [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Yan, Mei, E-mail: chm_yanm@ujn.edu.cn [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Yu, Jinghua [Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

    2013-04-03

    Graphical abstract: Core–shell Fe{sub 3}O{sub 4}–Au magnetic nanoparticles and P-GS@QDs were prepared to immobilize Ab{sub 1} and Ab{sub 2} respectively and combined to fabricate a novel sandwich-type ECL immunosensor for detecting CA125 at low concentration. Highlights: ► ECL immunosensor for CA125 based on a microfluidic strategy with a homemade ECL cell was proposed. ► Core–shell Fe{sub 3}O{sub 4}–Au magnetic nanoparticles were employed as the carriers of the primary antibodies. ► CdTe quantum dots functionalized graphene sheet were used for signal amplification. -- Abstract: In this paper, a novel, low-cost electrochemiluminescence (ECL) immunosensor using core–shell Fe{sub 3}O{sub 4}–Au magnetic nanoparticles (AuMNPs) as the carriers of the primary antibody of carbohydrate antigen 125 (CA125) was designed. Graphene sheet (GS) with property of good conductivity and large surface area was a captivating candidate to amplify ECL signal. We successively synthesized functionalized GS by loading large amounts of quantum dots (QDs) onto the poly (diallyldimethyl-ammonium chloride) (PDDA) coated graphene sheet (P-GS@QDs) via self-assembly electrostatic reactions, which were used to label secondary antibodies. The ECL immunosensors coupled with a microfluidic strategy exhibited a wide detection range (0.005–50 U mL{sup −1}) and a low detection limit (1.2 mU mL{sup −1}) with the help of an external magnetic field to gather immunosensors. The method was evaluated with clinical serum sample, receiving good correlation with results from commercially available analytical procedure.

  14. Nuclear magnetic resonance and LC/MS characterization of native and new mass-labeled fluorinated telomer alcohols, acids and unsaturated acids

    Energy Technology Data Exchange (ETDEWEB)

    Arsenault, G.; Chittim, B.; McAlees, A.; Yeo, B. [Wellington Laboratories Inc., Guelph, ON (Canada); Ellis, D.; Mabury, S.; Stock, N. [Toronto Univ., ON (Canada); Halldorson, T.; Tomy, G. [Dept. of Fisheries and Oceans, Winnipeg, MB (Canada); McCrindle, R. [Guelph Univ., ON (Canada)

    2004-09-15

    A variety of fluorinated compounds are used in a multitude of consumer products because of their ability to repel water and oil, resistance to heat, and chemical inertness. Recently, scientists and regulators have begun raising concerns about the potential health and environmental impact of perfluorinated compounds. Exposure to perfluoroalkyl acids, such as Perfluorooctanoic acid (PFOA), has been identified as a potential human health concern. A study has shown that telomer alcohols such as 2-perfluorooctylethanol can be metabolized by living organisms or biodegrade under environmental conditions to sequentially give the saturated fluorinated telomer acid (2- perfluorooctylethanoic acid), then the unsaturated telomer acid (2H-Perfluorooct-2-enoic acid), and eventually PFOA. Additional experimental work is necessary to determine the extent, if any, to which telomer product degradation may be a source of PFOA. The analysis for fluorinated compounds in environmental samples is performed, primarily, using LC/MS techniques. These analyses have been hindered by the lack of any commercially available mass-labeled fluorinated compounds for use as surrogates and thus may be restricting the amount of research conducted in this area. We have now synthesized the mass-labeled perfluoroalkyl telomer alcohols and the corresponding acids and unsaturated acids. We report in this study their 1H-, 2H-, 19F- and 13C-NMR characterizations along with GC/MS and LC/MS data and evaluation of their use as surrogate standards.

  15. Chelation of intracellular calcium blocks insulin action in the adipocyte

    International Nuclear Information System (INIS)

    Pershadsingh, H.A.; Shade, D.L.; Delfert, D.M.; McDonald, J.M.

    1987-01-01

    The hypothesis that intracellular Ca 2+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca 2+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl 2 and the Ca 2+ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl 2 from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 μM quin-2 or quin-2 AM had no effect on intracellular ATP concentration or the specific binding of 125 I=labeled insulin to adipocytes. These findings suggest that intracellular Ca 2+ is an essential component in the coupling of the insulin-activated receptor complex to cellular physiological/metabolic machinery. Furthermore, differing quin-2 AM dose-response profiles suggest the presence of dual Ca 2+ -dependent pathways in the adipocyte. One involves insulin stimulation of glucose transport and oxidation, whereas the other involves the antilipolytic action of insulin

  16. MR imaging of intracellular and extracellular deoxyhemoglobin

    International Nuclear Information System (INIS)

    Janick, P.A.; Grossman, R.I.; Asakura, T.

    1989-01-01

    MR imaging was performed on varying concentrations of intracellular and extracellular deoxyhemoglobin as well as varying proportions of deoxyhemoglobin and oxyhemoglobin in vitro at 1.5T with use of standard spin-echo and gradient-refocused spin sequences. This study indicates that susceptibility-induced T2 shortening occurs over a broad range of intracellular deoxyhemoglobin concentrations (maximal at hematocrits between 20% and 45%), reflecting diffusional effects at the cellular level. T2* gradient-echo imaging enhances the observed hypointensity in images of intracellular deoxyhemoglobin. The characteristic MR appearance of acute hemotomas can be modeled by the behavior of intracellular and extracellular deoxyhemoglobin and oxyhemoglobin

  17. USPIO-labeling in M1 and M2-polarized macrophages: An in vitro study using a clinical magnetic resonance scanner.

    Science.gov (United States)

    Zini, Chiara; Venneri, Mary A; Miglietta, Selenia; Caruso, Damiano; Porta, Natale; Isidori, Andrea M; Fiore, Daniela; Gianfrilli, Daniele; Petrozza, Vincenzo; Laghi, Andrea

    2018-08-01

    Aim of the study was to evaluate USPIO labeling in different macrophage populations using a clinical 3.0T MR unit with optical and electron microscopy as the gold standard. Human monocytic cell line THP-1 cells were differentiated into macrophages. Afterwards, M0 macrophages were incubated with IL-4 and IL-13 in order to obtain M2 polarized macrophages or with IFN-gamma and LPS for classical macrophage activation (M1). These groups were incubated with USPIO-MR contrast agent (P904) for 36 hr; M0, M0 + P904, M1 +  P904, and M2 + P904 were analyzed in gel phantoms with a 3.0T MR scanner. m-RNA of M1 and M2 markers confirmed the polarization of THP-1-derived macrophages. M2 + P904 showed a much higher T1 signal (p <  0.0001), a significantly lower (p < 0.0001) T2* signal, and significantly higher R* (p < 0.0001) compared to the other populations. Hystological analysis confirmed higher iron content in the M2-polarized population compared to both M1-polarized (p = 0.04) and M0-P904 (p = 0.003). Ultrastructure analysis demonstrated ubiquitous localization of P904 within the cellular compartments. Our results demonstrate that a selective USPIO-labeling of different macrophage populations can be detected in vitro using the 3.0T clinical scanner. © 2017 Wiley Periodicals, Inc.

  18. A Magnetic Sensor System for Biological Detection

    KAUST Repository

    Li, Fuquan

    2015-01-01

    Magnetic biosensors detect biological targets through sensing the stray field of magnetic beads which label the targets. Commonly, magnetic biosensors employ the “sandwich” method to immobilize biological targets, i.e., the targets are sandwiched

  19. Intracellular magnetophoresis of amyloplasts and induction of root curvature

    Science.gov (United States)

    Kuznetsov, O. A.; Hasenstein, K. H.

    1996-01-01

    High-gradient magnetic fields (HGMFs) were used to induce intracellular magnetophoresis of amyloplasts. The HGMFs were generated by placing a small ferromagnetic wedge into a uniform magnetic field or at the gap edge between two permanent magnets. In the vicinity of the tip of the wedge the dynamic factor of the magnetic field, delta(H2/2), was about 10(9) Oe2.cm-1, which subjected the amyloplasts to a force comparable to that of gravity. When roots of 2-d-old seedlings of flax (Linum usitatissimum L.) were positioned vertically and exposed to an HGMF, curvature away from the wedge was transient and lasted approximately 1 h. Average curvature obtained after placing magnets, wedge and seedlings on a 1-rpm clinostat for 2 h was 33 +/- 5 degrees. Roots of horizontally placed control seedlings without rotation curved about 47 +/- 4 degrees. The time course of curvature and changes in growth rate were similar for gravicurvature and for root curvature induced by HGMFs. Microscopy showed displacement of amyloplasts in vitro and in vivo. Studies with Arabidopsis thaliana (L.) Heynh. showed that the wild type responded to HGMFs but the starchless mutant TC7 did not. The data indicate that a magnetic force can be used to study the gravisensing and response system of roots.

  20. Direct monitoring by carbon-13 nuclear magnetic resonance spectroscopy of the metabolism and metabolic rate of 13C-labeled compounds in vivo.

    Science.gov (United States)

    Iida, K; Hidoh, O; Fukami, J; Kajiwara, M

    1991-01-01

    Carbon-13 nuclear magnetic resonance spectroscopy has been used to observe the transformations of [1-13C]-D-glucose to [1,1'-13C2]-D-trehalose, and [3-13C]-L-alanine to [2-13C]-L-glutamic acid in the living body of Gryllodes sigillatus. [3-13C]-D-Alanine was not metabolized. The metabolic rate of [1-13C]-D-glucose was found to be altered by prior injection of boric acid.

  1. Dynamics of intracellular information decoding

    International Nuclear Information System (INIS)

    Kobayashi, Tetsuya J; Kamimura, Atsushi

    2011-01-01

    A variety of cellular functions are robust even to substantial intrinsic and extrinsic noise in intracellular reactions and the environment that could be strong enough to impair or limit them. In particular, of substantial importance is cellular decision-making in which a cell chooses a fate or behavior on the basis of information conveyed in noisy external signals. For robust decoding, the crucial step is filtering out the noise inevitably added during information transmission. As a minimal and optimal implementation of such an information decoding process, the autocatalytic phosphorylation and autocatalytic dephosphorylation (aPadP) cycle was recently proposed. Here, we analyze the dynamical properties of the aPadP cycle in detail. We describe the dynamical roles of the stationary and short-term responses in determining the efficiency of information decoding and clarify the optimality of the threshold value of the stationary response and its information-theoretical meaning. Furthermore, we investigate the robustness of the aPadP cycle against the receptor inactivation time and intrinsic noise. Finally, we discuss the relationship among information decoding with information-dependent actions, bet-hedging and network modularity

  2. Dynamics of intracellular information decoding.

    Science.gov (United States)

    Kobayashi, Tetsuya J; Kamimura, Atsushi

    2011-10-01

    A variety of cellular functions are robust even to substantial intrinsic and extrinsic noise in intracellular reactions and the environment that could be strong enough to impair or limit them. In particular, of substantial importance is cellular decision-making in which a cell chooses a fate or behavior on the basis of information conveyed in noisy external signals. For robust decoding, the crucial step is filtering out the noise inevitably added during information transmission. As a minimal and optimal implementation of such an information decoding process, the autocatalytic phosphorylation and autocatalytic dephosphorylation (aPadP) cycle was recently proposed. Here, we analyze the dynamical properties of the aPadP cycle in detail. We describe the dynamical roles of the stationary and short-term responses in determining the efficiency of information decoding and clarify the optimality of the threshold value of the stationary response and its information-theoretical meaning. Furthermore, we investigate the robustness of the aPadP cycle against the receptor inactivation time and intrinsic noise. Finally, we discuss the relationship among information decoding with information-dependent actions, bet-hedging and network modularity.

  3. Secretome of obligate intracellular Rickettsia

    Science.gov (United States)

    Gillespie, Joseph J.; Kaur, Simran J.; Rahman, M. Sayeedur; Rennoll-Bankert, Kristen; Sears, Khandra T.; Beier-Sexton, Magda; Azad, Abdu F.

    2014-01-01

    The genus Rickettsia (Alphaproteobacteria, Rickettsiales, Rickettsiaceae) is comprised of obligate intracellular parasites, with virulent species of interest both as causes of emerging infectious diseases and for their potential deployment as bioterrorism agents. Currently, there are no effective commercially available vaccines, with treatment limited primarily to tetracycline antibiotics, although others (e.g. josamycin, ciprofloxacin, chloramphenicol, and azithromycin) are also effective. Much of the recent research geared toward understanding mechanisms underlying rickettsial pathogenicity has centered on characterization of secreted proteins that directly engage eukaryotic cells. Herein, we review all aspects of the Rickettsia secretome, including six secretion systems, 19 characterized secretory proteins, and potential moonlighting proteins identified on surfaces of multiple Rickettsia species. Employing bioinformatics and phylogenomics, we present novel structural and functional insight on each secretion system. Unexpectedly, our investigation revealed that the majority of characterized secretory proteins have not been assigned to their cognate secretion pathways. Furthermore, for most secretion pathways, the requisite signal sequences mediating translocation are poorly understood. As a blueprint for all known routes of protein translocation into host cells, this resource will assist research aimed at uniting characterized secreted proteins with their apposite secretion pathways. Furthermore, our work will help in the identification of novel secreted proteins involved in rickettsial ‘life on the inside’. PMID:25168200

  4. HYPERTHERMIA, INTRACELLULAR FREE CALCIUM AND CALCIUM IONOPHORES

    NARCIS (Netherlands)

    STEGE, GJJ; WIERENGA, PK; KAMPINGA, HH; KONINGS, AWT

    1993-01-01

    It is shown that heat-induced increase of intracellular calcium does not correlate with hyperthermic cell killing. Six different cell lines were investigated; in four (EAT, HeLa S3, L5178Y-R and L5178Y-S) heat treatments killing 90% of the cells did not affect the levels of intracellular free

  5. [Ferumoxide labeled Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells and its in vivo tracing in the brains of Macaca Fascicularis].

    Science.gov (United States)

    Feng, Ming; Wang, Ren-Zhi; Zhu, Hua; Zhang, Nan; Wang, Chang-Jun; Wei, Jun-Ji; Lu, Shan; Li, Qin; Yin, Xiao-Ming; Han, Qin; Ma, Wen-Bin; Qin, Chuang; Zhao, Chun-Hua; An, Yi-Hua; Kong, Yan-Guo

    2008-10-01

    To explore the method for labeling Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells (hBMSCs) with ferumoxide-PLL and evaluate the feasibility of its tracing after transplantation into the brains of Macaca Fascicularis. The hBMSCs were incubated with ferumoxide-PLL. Trypan blue staining, Prussian blue staining, and transmission electron microscope were performed to show intracellular iron, marking efficiency, and the vigor of the labeled cells. After the hBMSCs were transplanted into the brains of cynomolgus monkeys by stereotaxis, magnetic resonance imaging (MRI) was performed to trace the cells in vivo. Cell survival and differentiation were studied with immunohistochemistry, Prussian blue staining, and HE staining. The marking efficiency of the ferumoxide-PLL was 96%. Iron particles were found intracytoplasmic of the hBMSCs by Prussian blue staining and transmission electron microscopy. The relaxation rates of labeled cells in MRI were 4.4 and 4.2 times higher than those of the unlabeled cells. Hypointensity area was found by MRI three weeks after transplantation. Many hBMSCs and new vessels were found in the transplantation zone by pathological and immunofluorescence methods. Ferumoxide-PLL can effectively label hBMSCs and thus increase its contrast in MRI results. The cells can survive in the brains of cynomolgus monkeys. The labeled hBMSCs can be traced in vivo by MRI.

  6. Understanding Food Labels

    Science.gov (United States)

    ... Healthy eating for girls Understanding food labels Understanding food labels There is lots of info on food ... need to avoid because of food allergies. Other food label terms top In addition to the Nutrition ...

  7. Increasing the sensitivity for stem cell monitoring in system-function based magnetic particle imaging

    International Nuclear Information System (INIS)

    Them, Kolja; Szwargulski, P; Knopp, Tobias; Salamon, J; Kaul, M G; Ittrich, H; Sequeira, S; Lange, C

    2016-01-01

    The use of superparamagnetic iron oxide nanoparticles (SPIONs) has provided new possibilities in biophysics and biomedical imaging technologies. The magnetization dynamics of SPIONs, which can be influenced by the environment, are of central interest. In this work, different biological SPION environments are used to investigate three different calibration methods for stem cell monitoring in magnetic particle imaging. It is shown that calibrating using SPIONs immobilized via agarose gel or intracellular uptake results in superior stem cell image quality compared to mobile SPIONs in saline. This superior image quality enables more sensitive localization and identification of a significantly smaller number of magnetically labeled stem cells. The results are important for cell tracking and monitoring of future SPION based therapies such as hyperthermia based cancer therapies, targeted drug delivery, or tissue regeneration approaches where it is crucial to image a sufficiently small number of SPIONs interacting with biological matter. (paper)

  8. Intracellular localization of Arabidopsis sulfurtransferases.

    Science.gov (United States)

    Bauer, Michael; Dietrich, Christof; Nowak, Katharina; Sierralta, Walter D; Papenbrock, Jutta

    2004-06-01

    Sulfurtransferases (Str) comprise a group of enzymes widely distributed in archaea, eubacteria, and eukaryota which catalyze the transfer of a sulfur atom from suitable sulfur donors to nucleophilic sulfur acceptors. In all organisms analyzed to date, small gene families encoding Str proteins have been identified. The gene products were localized to different compartments of the cells. Our interest concerns the localization of Str proteins encoded in the nuclear genome of Arabidopsis. Computer-based prediction methods revealed localization in different compartments of the cell for six putative AtStrs. Several methods were used to determine the localization of the AtStr proteins experimentally. For AtStr1, a mitochondrial localization was demonstrated by immunodetection in the proteome of isolated mitochondria resolved by one- and two-dimensional gel electrophoresis and subsequent blotting. The respective mature AtStr1 protein was identified by mass spectrometry sequencing. The same result was obtained by transient expression of fusion constructs with the green fluorescent protein in Arabidopsis protoplasts, whereas AtStr2 was exclusively localized to the cytoplasm by this method. Three members of the single-domain AtStr were localized in the chloroplasts as demonstrated by transient expression of green fluorescent protein fusions in protoplasts and stomata, whereas the single-domain AtStr18 was shown to be cytoplasmic. The remarkable subcellular distribution of AtStr15 was additionally analyzed by transmission electron immunomicroscopy using a monospecific antibody against green fluorescent protein, indicating an attachment to the thylakoid membrane. The knowledge of the intracellular localization of the members of this multiprotein family will help elucidate their specific functions in the organism.

  9. Intracellular calcium homeostasis and signaling.

    Science.gov (United States)

    Brini, Marisa; Calì, Tito; Ottolini, Denis; Carafoli, Ernesto

    2013-01-01

    Ca(2+) is a universal carrier of biological information: it controls cell life from its origin at fertilization to its end in the process of programmed cell death. Ca(2+) is a conventional diffusible second messenger released inside cells by the interaction of first messengers with plasma membrane receptors. However, it can also penetrate directly into cells to deliver information without the intermediation of first or second messengers. Even more distinctively, Ca(2+) can act as a first messenger, by interacting with a plasma membrane receptor to set in motion intracellular signaling pathways that involve Ca(2+) itself. Perhaps the most distinctive property of the Ca(2+) signal is its ambivalence: while essential to the correct functioning of cells, Ca(2+) becomes an agent that mediates cell distress, or even (toxic) cell death, if its concentration and movements inside cells are not carefully tuned. Ca(2+) is controlled by reversible complexation to specific proteins, which could be pure Ca(2+) buffers, or which, in addition to buffering Ca(2+), also decode its signal to pass it on to targets. The most important actors in the buffering of cell Ca(2+) are proteins that transport it across the plasma membrane and the membrane of the organelles: some have high Ca(2+) affinity and low transport capacity (e.g., Ca(2+) pumps), others have opposite properties (e.g., the Ca(2+) uptake system of mitochondria). Between the initial event of fertilization, and the terminal event of programmed cell death, the Ca(2+) signal regulates the most important activities of the cell, from the expression of genes, to heart and muscle contraction and other motility processes, to diverse metabolic pathways involved in the generation of cell fuels.

  10. Differentiation of residual/recurrent gliomas from postradiation necrosis with arterial spin labeling and diffusion tensor magnetic resonance imaging-derived metrics

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Razek, Ahmed Abdel Khalek; El-Serougy, Lamiaa; Gaballa, Gada; Talaat, Mona [Mansoura Faculty of Medicine, Department of Diagnostic Radiology, Mansoura (Egypt); Abdelsalam, Mohamed [Mansoura Faculty of Medicine, Department of Neurology, Mansoura (Egypt)

    2018-02-15

    The aim of this study is to differentiate recurrent/residual gliomas from postradiation changes using arterial spin labeling (ASL) perfusion and diffusion tensor imaging (DTI)-derived metrics. Prospective study was conducted upon 42 patients with high-grade gliomas after radiotherapy only or prior to other therapies that underwent routine MR imaging, ASL, and DTI. The tumor blood flow (TBF), fractional anisotropy (FA), and mean diffusivity (MD) of the enhanced lesion and related edema were calculated. The lesion was categorized as recurrence/residual or postradiation changes. There was significant differences between residual/recurrent gliomas and postradiation changes of TBF (P = 0.001), FA (P = 0.001 and 0.04), and MD (P = 0.001) of enhanced lesion and related edema respectively. The area under the curve (AUC) of TBF of enhanced lesion and related edema used to differentiate residual/recurrent gliomas from postradiation changes were 0.95 and 0.93 and of MD were 0.95 and 0.81 and of FA were 0.81 and 0.695, respectively. Combined ASL and DTI metrics of the enhanced lesion revealed AUC of 0.98, accuracy of 95%, sensitivity of 93.8%, specificity of 95.8%, positive predictive value (PPV) of 93.8%, and negative predictive value (NPV) of 95.8%. Combined metrics of ASL and DTI of related edema revealed AUC of 0.97, accuracy of 92.5%, sensitivity of 93.8%, specificity of 91.7%, PPV of 88.2%, and NPV of 95.7. Combined ASL and DTI metrics of enhanced lesion and related edema are valuable noninvasive tools in differentiating residual/recurrent gliomas from postradiation changes. (orig.)

  11. Assessing the efficacy of nano- and micro-sized magnetic particles as contrast agents for MRI cell tracking.

    Directory of Open Access Journals (Sweden)

    Arthur Taylor

    Full Text Available Iron-oxide based contrast agents play an important role in magnetic resonance imaging (MRI of labelled cells in vivo. Currently, a wide range of such contrast agents is available with sizes varying from several nanometers up to a few micrometers and consisting of single or multiple magnetic cores. Here, we evaluate the effectiveness of these different particles for labelling and imaging stem cells, using a mouse mesenchymal stem cell line to investigate intracellular uptake, retention and processing of nano- and microsized contrast agents. The effect of intracellular confinement on transverse relaxivity was measured by MRI at 7 T and in compliance with the principles of the '3Rs', the suitability of the contrast agents for MR-based cell tracking in vivo was tested using a chick embryo model. We show that for all particles tested, relaxivity was markedly reduced following cellular internalisation, indicating that contrast agent relaxivity in colloidal suspension does not accurately predict performance in MR-based cell tracking studies. Using a bimodal imaging approach comprising fluorescence and MRI, we demonstrate that labelled MSC remain viable following in vivo transplantation and can be tracked effectively using MRI. Importantly, our data suggest that larger particles might confer advantages for longer-term imaging.

  12. Intracellular disposition of chitosan nanoparticles in macrophages: intracellular uptake, exocytosis, and intercellular transport

    Directory of Open Access Journals (Sweden)

    Jiang LQ

    2017-08-01

    Full Text Available Li Qun Jiang,1 Ting Yu Wang,1 Thomas J Webster,2 Hua-Jian Duan,1 Jing Ying Qiu,1 Zi Ming Zhao,1 Xiao Xing Yin,1,* Chun Li Zheng3,* 1Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, People’s Republic of China; 2Department of Chemical Engineering, Northeastern University, Boston, MA, USA; 3School of Pharmacy, China Pharmaceutical University, Nanjing, People’s Republic of China *These authors contributed equally to this work Abstract: Biodegradable nanomaterials have been widely used in numerous medical fields. To further improve such efforts, this study focused on the intracellular disposition of chitosan nanoparticles (CsNPs in macrophages, a primary cell of the mononuclear phagocyte system (MPS. Such interactions with the MPS determine the nanoparticle retention time in the body and consequently play a significant role in their own clinical safety. In this study, various dye-labeled CsNPs (about 250 nm were prepared, and a murine macrophage cell line (RAW 264.7 was selected as a model macrophage. The results showed two mechanisms of macrophage incorporation of CsNPs, ie, a clathrin-mediated endocytosis pathway (the primary and phagocytosis. Following internalization, the particles partly dissociated in the cells, indicating cellular digestion of the nanoparticles. It was proved that, after intracellular uptake, a large proportion of CsNPs were exocytosed within 24 h; this excretion induced a decrease in fluorescence intensity in cells by 69%, with the remaining particles possessing difficulty being cleared. Exocytosis could be inhibited by both wortmannin and vacuolin-1, indicating that CsNP uptake was mediated by lysosomal and multivesicular body pathways, and after exocytosis, the reuptake of CsNPs by neighboring cells was verified by further experiments. This study, thus, elucidated the fate of CsNPs in macrophages as well as identified cellular disposition

  13. Getting Across the Plasma Membrane and Beyond: Intracellular Uses of Colloidal Semiconductor Nanocrystals

    Directory of Open Access Journals (Sweden)

    Camilla Luccardini

    2007-01-01

    Full Text Available Semiconductor nanocrystals (NCs are increasingly being used as photoluminescen markers in biological imaging. Their brightness, large Stokes shift, and high photostability compared to organic fluorophores permit the exploration of biological phenomena at the single-molecule scale with superior temporal resolution and spatial precision. NCs have predominantly been used as extracellular markers for tagging and tracking membrane proteins. Successful internalization and intracellular labelling with NCs have been demonstrated for both fixed immunolabelled and live cells. However, the precise localization and subcellular compartment labelled are less clear. Generally, live cell studies are limited by the requirement of fairly invasive protocols for loading NCs and the relatively large size of NCs compared to the cellular machinery, along with the subsequent sequestration of NCs in endosomal/lysosomal compartments. For long-period observation the potential cytotoxicity of cytoplasmically loaded NCs must be evaluated. This review focuses on the challenges of intracellular uses of NCs.

  14. Intracellular mediators of potassium-induced aldosterone secretion

    International Nuclear Information System (INIS)

    Ganguly, A.; Chiou, S.; Davis, J.S.

    1990-01-01

    We have investigated the intracellular messengers of potassium in eliciting aldosterone secretion in calf adrenal glomerulosa cells since there were unresolved issues relating to the role of phosphoinositides, cAMP and protein kinases. We observed no evidence of hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) in 3 H-inositol labeled alf adrenal cells or increase of cAMP in response to potassium. Addition of calcium channel blocker, nitrendipine after stimulating adrenal glomerulosa cells with potassium, markedly inhibited aldosterone secretion. A calmodulin inhibitor (W-7) produced greater reduction of aldosterone secretion than an inhibitor of protein kinase C (H-7). These results suggest that a rise in cytosolic free calcium concentration through voltage-dependent calcium channel and calmodulin are the critical determinants of aldosterone secretion stimulated by potassium

  15. Evaluating Nanoparticle Sensor Design for Intracellular pH Measurements

    DEFF Research Database (Denmark)

    Benjaminsen, Rikke Vicki; Sun, Honghao; Henriksen, Jonas Rosager

    2011-01-01

    Particle-based nanosensors have over the last decade been designed for optical fluorescent-based ratiometric measurements of pH in living cells. However, quantitative and time-resolved intracellular measurements of pH in endosomes and lysosomes using particle nanosensors is challenging...... and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle...... quantification of pH is an unfortunate result when measuring pH too close to the limit of the sensitive range of the sensors. Triple-labeled nanosensors with a pH measurement range of 3.2-7.0, which was synthesized by adding two pH-sensitive fluorophores with different pKa to each sensor, seem to be a solution...

  16. Repetitive transcranial magnetic stimulation of the supplementary motor area in treatment-resistant obsessive-compulsive disorder: An open-label pilot study.

    Science.gov (United States)

    Lee, Young-Ji; Koo, Bon-Hoon; Seo, Wan-Seok; Kim, Hye-Geum; Kim, Ji-Yean; Cheon, Eun-Jin

    2017-10-01

    Obsessive-compulsive disorder (OCD) is a severely distressing disorder represented by obsessions and compulsions. A significant proportion of OCD patients fail to improve with conventional treatment methods. Repetitive transcranial magnetic stimulation (rTMS) has been proposed as an alternative for OCD treatment. Functional neuroimaging studies indicate that OCD is associated with increased activity in the supplementary motor area (SMA), a region that plays an important role in the pathophysiology of this disorder. In this study, we assessed the efficacy of augmentation with 1Hz rTMS over the SMA in treatment-resistant OCD patients. The participants received 1Hz rTMS over the SMA in 20 daily sessions for 4weeks. We observed significant reduction in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score at the 4th week of the treatment. Reduction in compulsion contributed to the reduction of global Y-BOCS whereas there was no significant reduction in obsession. Clinical global impression-global improvement also showed significant change at the 2nd and 4th week of the treatment. No additional significant changes or significant adverse effects were seen. These findings suggest that 1Hz rTMS over the SMA can be an efficient and safe add-on therapeutic method in treatment-resistant patients with OCD. Further controlled studies in larger samples are required to confirm the effect of 1Hz rTMS over the SMA in OCD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Multidimensional oriented solid-state NMR experiments enable the sequential assignment of uniformly 15N labeled integral membrane proteins in magnetically aligned lipid bilayers

    International Nuclear Information System (INIS)

    Mote, Kaustubh R.; Gopinath, T.; Traaseth, Nathaniel J.; Kitchen, Jason; Gor’kov, Peter L.; Brey, William W.; Veglia, Gianluigi

    2011-01-01

    Oriented solid-state NMR is the most direct methodology to obtain the orientation of membrane proteins with respect to the lipid bilayer. The method consists of measuring 1 H- 15 N dipolar couplings (DC) and 15 N anisotropic chemical shifts (CSA) for membrane proteins that are uniformly aligned with respect to the membrane bilayer. A significant advantage of this approach is that tilt and azimuthal (rotational) angles of the protein domains can be directly derived from analytical expression of DC and CSA values, or, alternatively, obtained by refining protein structures using these values as harmonic restraints in simulated annealing calculations. The Achilles’ heel of this approach is the lack of suitable experiments for sequential assignment of the amide resonances. In this Article, we present a new pulse sequence that integrates proton driven spin diffusion (PDSD) with sensitivity-enhanced PISEMA in a 3D experiment ([ 1 H, 15 N]-SE-PISEMA-PDSD). The incorporation of 2D 15 N/ 15 N spin diffusion experiments into this new 3D experiment leads to the complete and unambiguous assignment of the 15 N resonances. The feasibility of this approach is demonstrated for the membrane protein sarcolipin reconstituted in magnetically aligned lipid bicelles. Taken with low electric field probe technology, this approach will propel the determination of sequential assignment as well as structure and topology of larger integral membrane proteins in aligned lipid bilayers.

  18. Multidimensional oriented solid-state NMR experiments enable the sequential assignment of uniformly 15N labeled integral membrane proteins in magnetically aligned lipid bilayers.

    Science.gov (United States)

    Mote, Kaustubh R; Gopinath, T; Traaseth, Nathaniel J; Kitchen, Jason; Gor'kov, Peter L; Brey, William W; Veglia, Gianluigi

    2011-11-01

    Oriented solid-state NMR is the most direct methodology to obtain the orientation of membrane proteins with respect to the lipid bilayer. The method consists of measuring (1)H-(15)N dipolar couplings (DC) and (15)N anisotropic chemical shifts (CSA) for membrane proteins that are uniformly aligned with respect to the membrane bilayer. A significant advantage of this approach is that tilt and azimuthal (rotational) angles of the protein domains can be directly derived from analytical expression of DC and CSA values, or, alternatively, obtained by refining protein structures using these values as harmonic restraints in simulated annealing calculations. The Achilles' heel of this approach is the lack of suitable experiments for sequential assignment of the amide resonances. In this Article, we present a new pulse sequence that integrates proton driven spin diffusion (PDSD) with sensitivity-enhanced PISEMA in a 3D experiment ([(1)H,(15)N]-SE-PISEMA-PDSD). The incorporation of 2D (15)N/(15)N spin diffusion experiments into this new 3D experiment leads to the complete and unambiguous assignment of the (15)N resonances. The feasibility of this approach is demonstrated for the membrane protein sarcolipin reconstituted in magnetically aligned lipid bicelles. Taken with low electric field probe technology, this approach will propel the determination of sequential assignment as well as structure and topology of larger integral membrane proteins in aligned lipid bilayers. © Springer Science+Business Media B.V. 2011

  19. T1 and T2 relaxivity of intracellular and extracellular USPIO at 1.5T and 3T clinical MR scanning

    International Nuclear Information System (INIS)

    Simon, Gerhard H.; Bauer, Jan; Saborovski, Olaf; Fu, Yanjun; Wendland, Michael F.; Daldrup-Link, Heike E.; Corot, Claire

    2006-01-01

    In this study we evaluated the effects of intracellular compartmentalization of the ultrasmall superparamagnetic iron oxide (USPIO) ferumoxtran-10 on its proton T1 and T2 relaxivities at 1.5 and 3T. Monocytes were labeled with ferumoxtran-10 by simple incubation. Decreasing quantities of ferumoxtran-10-labeled cells (2.5 x 10 7 -0.3 x 10 7 cells/ml) and decreasing concentrations of free ferumoxtran-10 (without cells) in Ficoll solution were evaluated with 1.5 and 3T clinical magnetic resonance (MR) scanners. Pulse sequences comprised axial spin echo (SE) sequences with multiple TRs and fixed TE and SE sequences with fixed TR and increasing TEs. Signal intensity measurements were used to calculate T1 and T2 relaxation times of all samples, assuming a monoexponential signal decay. The iron content in all samples was determined by inductively coupled plasma atomic emission spectrometry and used for calculating relaxivities. Measurements at 1.5T and 3T showed higher T1 and T2 relaxivity values of free extracellular ferumoxtran-10 as opposed to intracellularly compartmentalized ferumoxtran-10, under the evaluated conditions of homogeneously dispersed contrast agents/cells in Ficoll solution and a cell density of up to 2.5 x 10 7 cells/ml. At 3T, differences in T1-relaxivities between intra- and extracellular USPIO were smaller, while differences in USPIO T2-relaxivities were similar compared with 1.5T. In conclusion, cellular compartmentalization of ferumoxtran-10 changes proton relaxivity. (orig.)

  20. Issues in Data Labelling

    NARCIS (Netherlands)

    Cowie, Roddy; Cox, Cate; Martin, Jeam-Claude; Batliner, Anton; Heylen, Dirk K.J.; Karpouzis, Kostas; Cowie, Roddy; Pelachaud, Catherine; Petta, Paolo

    2011-01-01

    Labelling emotion databases is not a purely technical matter. It is bound up with theoretical issues. Different issues affect labelling of emotional content, labelling of the signs that convey emotion, and labelling of the relevant context. Linked to these are representational issues, involving time

  1. SAIL--stereo-array isotope labeling.

    Science.gov (United States)

    Kainosho, Masatsune; Güntert, Peter

    2009-11-01

    Optimal stereospecific and regiospecific labeling of proteins with stable isotopes enhances the nuclear magnetic resonance (NMR) method for the determination of the three-dimensional protein structures in solution. Stereo-array isotope labeling (SAIL) offers sharpened lines, spectral simplification without loss of information and the ability to rapidly collect and automatically evaluate the structural restraints required to solve a high-quality solution structure for proteins up to twice as large as before. This review gives an overview of stable isotope labeling methods for NMR spectroscopy with proteins and provides an in-depth treatment of the SAIL technology.

  2. Left Gastric Vein Visualization with Hepatopetal Flow Information in Healthy Subjects Using Non-Contrast-Enhanced Magnetic Resonance Angiography with Balanced Steady-State Free-Precession Sequence and Time-Spatial Labeling Inversion Pulse.

    Science.gov (United States)

    Furuta, Akihiro; Isoda, Hiroyoshi; Ohno, Tsuyoshi; Ono, Ayako; Yamashita, Rikiya; Arizono, Shigeki; Kido, Aki; Sakashita, Naotaka; Togashi, Kaori

    2018-01-01

    To selectively visualize the left gastric vein (LGV) with hepatopetal flow information by non-contrast-enhanced magnetic resonance angiography under a hypothesis that change in the LGV flow direction can predict the development of esophageal varices; and to optimize the acquisition protocol in healthy subjects. Respiratory-gated three-dimensional balanced steady-state free-precession scans were conducted on 31 healthy subjects using two methods (A and B) for visualizing the LGV with hepatopetal flow. In method A, two time-spatial labeling inversion pulses (Time-SLIP) were placed on the whole abdomen and the area from the gastric fornix to the upper body, excluding the LGV area. In method B, nonselective inversion recovery pulse was used and one Time-SLIP was placed on the esophagogastric junction. The detectability and consistency of LGV were evaluated using the two methods and ultrasonography (US). Left gastric veins by method A, B, and US were detected in 30 (97%), 24 (77%), and 23 (74%) subjects, respectively. LGV flow by US was hepatopetal in 22 subjects and stagnant in one subject. All hepatopetal LGVs by US coincided with the visualized vessels in both methods. One subject with non-visualized LGV in method A showed stagnant LGV by US. Hepatopetal LGV could be selectively visualized by method A in healthy subjects.

  3. Positron emission tomography/computed tomographic and magnetic resonance imaging in a murine model of progressive atherosclerosis using (64)Cu-labeled glycoprotein VI-Fc.

    Science.gov (United States)

    Bigalke, Boris; Phinikaridou, Alkystis; Andia, Marcelo E; Cooper, Margaret S; Schuster, Andreas; Schönberger, Tanja; Griessinger, Christoph M; Wurster, Thomas; Onthank, David; Ungerer, Martin; Gawaz, Meinrad; Nagel, Eike; Botnar, Rene M

    2013-11-01

    Plaque erosion leads to exposure of subendothelial collagen, which may be targeted by glycoprotein VI (GPVI). We aimed to detect plaque erosion using (64)Cu-labeled GPVI-Fc (fragment crystallized). Four-week-old male apolipoprotein E-deficient (ApoE(-/-)) mice (n=6) were fed a high-fat diet for 12 weeks. C57BL/6J wild-type (WT) mice served as controls (n=6). Another group of WT mice received a ligation injury of the left carotid artery (n=6) or sham procedure (n=4). All mice received a total activity of ≈12 MBq (64)Cu-GPVI-Fc by tail vein injection followed by delayed (24 hours) positron emission tomography using a NanoPET/computed tomographic scanner (Mediso, Hungary; Bioscan, USA) with an acquisition time of 1800 seconds. Seventy-two hours after positron emission tomography/computed tomography, all mice were scanned 2 hours after intravenous administration of 0.2 mmol/kg body weight of a gadolinium-based elastin-specific MR contrast agent. MRI was performed on a 3-T clinical scanner (Philips Healthcare, Best, The Netherlands). In ApoE(-/-) mice, the (64)Cu-GPVI-Fc uptake in the aortic arch was significantly higher compared with WT mice (ApoE(-/-): 13.2±1.5 Bq/cm(3) versus WT mice: 5.1±0.5 Bq/cm(3); P=0.028). (64)Cu-GPVI-Fc uptake was also higher in the injured left carotid artery wall compared with the intact right carotid artery of WT mice and as a trend compared with sham procedure (injured: 20.7±1.3 Bq/cm(3) versus intact: 2.3±0.5 Bq/cm(3); P=0.028 versus sham: 12.7±1.7 Bq/cm(3); P=0.068). Results were confirmed by ex vivo histology and in vivo MRI with elastin-specific MR contrast agent that measures plaque burden and vessel wall remodeling. Higher R1 relaxation rates were found in the injured carotid wall with a T1 mapping sequence (injured: 1.44±0.08 s(-1) versus intact: 0.91±0.02 s(-1); P=0.028 versus sham: 0.97±0.05 s(-1); P=0.068) and in the aortic arch of ApoE(-/-) mice compared with WT mice (ApoE(-/-): 1.49±0.05 s(-1) versus WT: 0.92±0.04 s

  4. Nanoparticles for intracellular-targeted drug delivery

    International Nuclear Information System (INIS)

    Paulo, Cristiana S O; Pires das Neves, Ricardo; Ferreira, Lino S

    2011-01-01

    Nanoparticles (NPs) are very promising for the intracellular delivery of anticancer and immunomodulatory drugs, stem cell differentiation biomolecules and cell activity modulators. Although initial studies in the area of intracellular drug delivery have been performed in the delivery of DNA, there is an increasing interest in the use of other molecules to modulate cell activity. Herein, we review the latest advances in the intracellular-targeted delivery of short interference RNA, proteins and small molecules using NPs. In most cases, the drugs act at different cellular organelles and therefore the drug-containing NPs should be directed to precise locations within the cell. This will lead to the desired magnitude and duration of the drug effects. The spatial control in the intracellular delivery might open new avenues to modulate cell activity while avoiding side-effects.

  5. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    thods of reduction of metal ions using plants or microorganisms are often ... have several advantages over bacteria, they are often pre- ferred. ... in static condition for a period of 7 days. ... work was focused on the production of intracellular gold.

  6. Mixed Map Labeling

    Directory of Open Access Journals (Sweden)

    Maarten Löffler

    2016-12-01

    Full Text Available Point feature map labeling is a geometric visualization problem, in which a set of input points must be labeled with a set of disjoint rectangles (the bounding boxes of the label texts. It is predominantly motivated by label placement in maps but it also has other visualization applications. Typically, labeling models either use internal labels, which must touch their feature point, or external (boundary labels, which are placed outside the input image and which are connected to their feature points by crossing-free leader lines. In this paper we study polynomial-time algorithms for maximizing the number of internal labels in a mixed labeling model that combines internal and external labels. The model requires that all leaders are parallel to a given orientation θ ∈ [0, 2π, the value of which influences the geometric properties and hence the running times of our algorithms.

  7. Intracellular Delivery of Nanobodies for Imaging of Target Proteins in Live Cells.

    Science.gov (United States)

    Röder, Ruth; Helma, Jonas; Preiß, Tobias; Rädler, Joachim O; Leonhardt, Heinrich; Wagner, Ernst

    2017-01-01

    Cytosolic delivery of nanobodies for molecular target binding and fluorescent labeling in living cells. Fluorescently labeled nanobodies were formulated with sixteen different sequence-defined oligoaminoamides. The delivery of formulated anti-GFP nanobodies into different target protein-containing HeLa cell lines was investigated by flow cytometry and fluorescence microscopy. Nanoparticle formation was analyzed by fluorescence correlation spectroscopy. The initial oligomer screen identified two cationizable four-arm structured oligomers (734, 735) which mediate intracellular nanobody delivery in a receptor-independent (734) or folate receptor facilitated (735) process. The presence of disulfide-forming cysteines in the oligomers was found critical for the formation of stable protein nanoparticles of around 20 nm diameter. Delivery of labeled GFP nanobodies or lamin nanobodies to their cellular targets was demonstrated by fluorescence microscopy including time lapse studies. Two sequence-defined oligoaminoamides with or without folate for receptor targeting were identified as effective carriers for intracellular nanobody delivery, as exemplified by GFP or lamin binding in living cells. Due to the conserved nanobody core structure, the methods should be applicable for a broad range of nanobodies directed to different intracellular targets.

  8. Mycobacterium intracellulare Infection Mimicking Progression of Scleroderma

    DEFF Research Database (Denmark)

    Krabbe, Simon; Engelhart, Merete; Thybo, Sören

    2017-01-01

    This case report describes a patient with scleroderma who developed Mycobacterium intracellulare infection, which for more than a year mimicked worsening of her connective tissue disorder. The patient was diagnosed with scleroderma based on puffy fingers that developed into sclerodactyly, abnormal......, unfortunately with significant scarring. Immunodeficiency testing was unremarkable. In summary, an infection with Mycobacterium intracellulare was mistaken for an unusually severe progression of scleroderma....

  9. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Yoon [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Severance Hospital, Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Seoul (Korea, Republic of); Kim, Chan Kyo; Park, Byung Kwan [Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Kim, EunJu [Philips Healthcare Korea, Seoul (Korea, Republic of)

    2014-09-13

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88 % of right and 92 % of left renal arteries, while it was 96 % in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82 % and 100 % for reader 1 and 82 % and 95 % for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. (orig.)

  10. 101 labeled brain images and a consistent human cortical labeling protocol

    Directory of Open Access Journals (Sweden)

    Arno eKlein

    2012-12-01

    Full Text Available We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The Desikan-Killiany-Tourville (DKT protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://www.mindboggle.info/data/ website.

  11. 101 Labeled Brain Images and a Consistent Human Cortical Labeling Protocol

    Science.gov (United States)

    Klein, Arno; Tourville, Jason

    2012-01-01

    We introduce the Mindboggle-101 dataset, the largest and most complete set of free, publicly accessible, manually labeled human brain images. To manually label the macroscopic anatomy in magnetic resonance images of 101 healthy participants, we created a new cortical labeling protocol that relies on robust anatomical landmarks and minimal manual edits after initialization with automated labels. The “Desikan–Killiany–Tourville” (DKT) protocol is intended to improve the ease, consistency, and accuracy of labeling human cortical areas. Given how difficult it is to label brains, the Mindboggle-101 dataset is intended to serve as brain atlases for use in labeling other brains, as a normative dataset to establish morphometric variation in a healthy population for comparison against clinical populations, and contribute to the development, training, testing, and evaluation of automated registration and labeling algorithms. To this end, we also introduce benchmarks for the evaluation of such algorithms by comparing our manual labels with labels automatically generated by probabilistic and multi-atlas registration-based approaches. All data and related software and updated information are available on the http://mindboggle.info/data website. PMID:23227001

  12. Tissue- and Cell-Specific Co-localization of Intracellular Gelatinolytic Activity and Matrix Metalloproteinase 2

    Science.gov (United States)

    Solli, Ann Iren; Fadnes, Bodil; Winberg, Jan-Olof; Uhlin-Hansen, Lars

    2013-01-01

    Matrix metalloproteinase 2 (MMP-2) is a proteolytic enzyme that degrades extracellular matrix proteins. Recent studies indicate that MMP-2 also has a role in intracellular proteolysis during various pathological conditions, such as ischemic injuries in heart and brain and in tumor growth. The present study was performed to map the distribution of intracellular MMP-2 activity in various mouse tissues and cells under physiological conditions. Samples from normal brain, heart, lung, liver, spleen, pancreas, kidney, adrenal gland, thyroid gland, gonads, oral mucosa, salivary glands, esophagus, intestines, and skin were subjected to high-resolution in situ gelatin zymography and immunohistochemical staining. In hepatocytes, cardiac myocytes, kidney tubuli cells, epithelial cells in the oral mucosa as well as in excretory ducts of salivary glands, and adrenal cortical cells, we found strong intracellular gelatinolytic activity that was significantly reduced by the metalloprotease inhibitor EDTA but not by the cysteine protease inhibitor E-64. Furthermore, the gelatinolytic activity was co-localized with MMP-2. Western blotting and electron microscopy combined with immunogold labeling revealed the presence of MMP-2 in different intracellular compartments of isolated hepatocytes. Our results indicate that MMP-2 takes part in intracellular proteolysis in specific tissues and cells during physiological conditions. PMID:23482328

  13. The effect of sodium bicarbonate on intracellular pH using 31P-MR spectroscopy

    International Nuclear Information System (INIS)

    Nakashima, Kazuya; Kashiwagi, Shiro; Ito, Haruhide; Yamashita, Tetsuo; Kitahara, Tetsuhiro; Nakayama, Naoto; Saito, Kennichi

    1997-01-01

    This report deals with the effects of sodium bicarbonate on the intracellular pH of the brain and cerebral blood flow (CBF); five normal volunteers were studied. Intracellular pH and CBF were measured by phosphorus 31 magnetic resonance spectroscopy ( 31 P-MRS) and stable xenon computed tomography (Xe-CT), respectively. Each individual received 7% sodium bicarbonate (3.5 ml/kg body weight), infused intravenously over a 15-min period. Intracellular pH, CBF, and physiological parameters were determined before and after the injection. Intracellular pH was significantly decreased and CBF was increased. Among the physiological parameters, the hematocrit was significantly decreased and arterial pressure of carbon dioxide (PaCO 2 ), increased. These results suggest that increasing CO 2 contributes to the decrease in intracellular pH. In conclusion, three factors increase CBF during the administration of sodium bicarbonate to humans: arterial dilatation in response to carbon dioxide; decrease of the hematocrit, and intracellular cerebral acidosis. (author)

  14. RFP tags for labeling secretory pathway proteins

    Energy Technology Data Exchange (ETDEWEB)

    Han, Liyang; Zhao, Yanhua [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhang, Xi; Peng, Jianxin [College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Xu, Pingyong, E-mail: pyxu@ibp.ac.cn [Key Laboratory of Interdisciplinary Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China); Huan, Shuangyan, E-mail: shuangyanhuan@163.com [State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhang, Mingshu, E-mail: mingshu1984@gmail.com [Key Laboratory of Interdisciplinary Research, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2014-05-09

    Highlights: • Membrane protein Orai1 can be used to report the fusion properties of RFPs. • Artificial puncta are affected by dissociation constant as well as pKa of RFPs. • Among tested RFPs mOrange2 is the best choice for secretory protein labeling. - Abstract: Red fluorescent proteins (RFPs) are useful tools for live cell and multi-color imaging in biological studies. However, when labeling proteins in secretory pathway, many RFPs are prone to form artificial puncta, which may severely impede their further uses. Here we report a fast and easy method to evaluate RFPs fusion properties by attaching RFPs to an environment sensitive membrane protein Orai1. In addition, we revealed that intracellular artificial puncta are actually colocalized with lysosome, thus besides monomeric properties, pKa value of RFPs is also a key factor for forming intracellular artificial puncta. In summary, our current study provides a useful guide for choosing appropriate RFP for labeling secretory membrane proteins. Among RFPs tested, mOrange2 is highly recommended based on excellent monomeric property, appropriate pKa and high brightness.

  15. Noncontrast-enhanced magnetic resonance renal angiography using a repetitive artery and venous labelling technique at 3 T: comparison with contrast-enhanced magnetic resonance angiography in subjects with normal renal function.

    Science.gov (United States)

    Park, Sung Yoon; Kim, Chan Kyo; Kim, EunJu; Park, Byung Kwan

    2015-02-01

    To investigate the feasibility of noncontrast-enhanced MR angiography (NC-MRA) using the repetitive artery and venous labelling (RAVEL) technique to evaluate renal arteries compared to contrast-enhanced MR angiography (CE-MRA). Twenty-five subjects with normal renal function underwent NC-MRA using a RAVEL technique and CE-MRA at 3 T. Two independent readers analysed the MRA images. Image quality, number of renal arteries, presence or absence of an early branching vessel, and diameter of the main renal arteries were evaluated. The overall image quality of NC-MRA was fair or greater in 88% of right and 92% of left renal arteries, while it was 96% in both sides with CE-MRA. On NC-MRA, the number of renal arteries in all subjects was perfectly predicted by both readers. Sensitivity and specificity for predicting early branching vessels were 82% and 100% for reader 1 and 82% and 95% for reader 2. Inter-modality agreement for comparing the diameters of main renal arteries was good or excellent at all segments for both readers. Inter-reader agreement was moderate or good at all segments except at the right distal segment on NC-MRA. NC-MRA with the RAVEL technique at 3 T may have comparable diagnostic feasibility for evaluating renal arteries compared to CE-MRA. • Accurate pre-treatment evaluation of renal artery anatomy helps clinical decision-making. • NC-MRA using RAVEL offers acceptable imaging quality for renal artery evaluation. • The 3 T RAVEL technique provides excellent diagnostic performance for renal artery evaluation. • The 3 T RAVEL technique may be an alternative to contrast-enhanced MRA.

  16. Succesful labelling schemes

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Stacey, Julia

    2001-01-01

    . In the spring of 2001 MAPP carried out an extensive consumer study with special emphasis on the Nordic environmentally friendly label 'the swan'. The purpose was to find out how much consumers actually know and use various labelling schemes. 869 households were contacted and asked to fill in a questionnaire...... it into consideration when I go shopping. The respondent was asked to pick the most suitable answer, which described her use of each label. 29% - also called 'the labelling blind' - responded that they basically only knew the recycling label and the Government controlled organic label 'Ø-mærket'. Another segment of 6...

  17. Synthesizing labeled compounds

    International Nuclear Information System (INIS)

    London, R.E.; Matwiyoff, N.A.; Unkefer, C.J.; Walker, T.E.

    1983-01-01

    A metabolic study is presented of the chemical reactions provided by isotopic labeling and NMR spectroscopy. Synthesis of 13 C-labeled D-glucose, a 6-carbon sugar, involves adding a labeled nitrile group to the 5-carbon sugar D-arabinose by reaction with labeled hydrogen cyanide. The product of this reaction is then reduced and hydrolyzed to a mixture of the labeled sugars. The two sugars are separated by absorption chromotography. The synthesis of 13 C-labeled L-tyrosine, an amino acid, is also presented

  18. Efficient intracellular delivery and improved biocompatibility of colloidal silver nanoparticles towards intracellular SERS immuno-sensing.

    Science.gov (United States)

    Bhardwaj, Vinay; Srinivasan, Supriya; McGoron, Anthony J

    2015-06-21

    High throughput intracellular delivery strategies, electroporation, passive and TATHA2 facilitated diffusion of colloidal silver nanoparticles (AgNPs) are investigated for cellular toxicity and uptake using state-of-art analytical techniques. The TATHA2 facilitated approach efficiently delivered high payload with no toxicity, pre-requisites for intracellular applications of plasmonic metal nanoparticles (PMNPs) in sensing and therapeutics.

  19. Magnetic sensor device

    NARCIS (Netherlands)

    2009-01-01

    The present invention provides a sensor device and a method for detg. the presence and/or amt. of target moieties in a sample fluid, the target moieties being labeled with magnetic or magnetizable objects. The sensor device comprises a magnetic field generating means adapted for applying a retention

  20. Intracellular pH and inorganic phosphate content of heart in vivo: A 31P-NMR study

    International Nuclear Information System (INIS)

    Katz, L.A.; Swain, J.A.; Portman, M.A.; Balaban, R.S.

    1988-01-01

    Studies were performed to determine the contribution of red blood cells to the 31 P-nuclear magnetic resonance (NMR) spectrum of the canine heart in vivo and the feasibility of measuring myocardial intracellular phosphate and pH. This was accomplished by replacing whole blood with a perfluorochemical perfusion emulsion blood substitute, Oxypherol, and noting the difference in the 31 P-NMR spectrum of the heart. NMR data were collected with a NMR transmitter-receiver coil on the surface of the distal portion of the left ventricle. These studies demonstrated that a small contribution from 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters in the blood could be detected. The magnitude and shift of these blood-borne signals permitted the relative quantification of intracellular inorganic phosphate (P i ) content as well as intracellular pH. Under resting conditions, the intracellular ATP/P i was 7.0 ± 0.08. This corresponds to a free intracellular P 1 content of ∼ 0.8 μmol./g wet wt. The intracellular pH was 7.10 ± 0.01. Acute respiratory alkalosis and acidosis, with the arterial pH ranging from ∼7.0 to 7.7, resulted in only small changes in the intracellular pH. These latter results demonstrate an effective myocardial intracellular proton-buffering mechanism in vivo

  1. Nanoparticulated magnetic drug delivery systems: Preparation and magnetic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Morais, P C, E-mail: pcmor@unb.b [Universidade de BrasIlia, Instituto de Fisica, Nucleo de Fisica Aplicada, Brasilia DF 70910-900 (Brazil)

    2010-03-01

    This paper describes how magnetic resonance can be successfully used as a tool to help customize and quantify nanosized magnetic particles while labeling cells and administered in animals for targeting different biological sites. Customization of magnetic nanoparticles is addressed here in terms of production of complex magnetic drug delivery systems whereas quantification of magnetic nanoparticle in different biological compartments emerges as a key experimental information to assess time-dependent magnetic nanoparticle biodistribution profiles. Examples of using magnetic resonance in unfolding information regarding the pharmacokinetics of intravenously-injected surface-functionalized magnetic nanoparticles in animals are included in the paper.

  2. Fully glutathione degradable waterborne polyurethane nanocarriers: Preparation, redox-sensitivity, and triggered intracellular drug release

    Energy Technology Data Exchange (ETDEWEB)

    Omrani, Ismail; Babanejad, Niloofar; Shendi, Hasan Kashef; Nabid, Mohammad Reza, E-mail: m-nabid@sbu.ac.ir

    2017-01-01

    Polyurethanes are important class of biomaterials that are extensively used in medical devices. In spite of their easy synthesis, polyurethanes that are fully degradable in response to the intracellular reducing environment are less explored for controlled drug delivery. Herein, a novel glutathione degradable waterborne polyurethane (WPU) nanocarrier for redox triggered intracellular delivery of a model lipophilic anticancer drug, doxorubicin (DOX) is reported. The WPU was prepared from polyaddition reaction of isophorone diisocyanate (IPDI) and a novel linear polyester polyol involving disulfide linkage, disulfide labeled chain extender, dimethylolpropionic acid (DMPA) using dibutyltin dilaurate (DBTDL) as a catalyst. The resulting polyurethane self-assembles into nanocarrier in water. The dynamic light scattering (DLS) measurements and scanning electron microscope (SEM) revealed fast swelling and disruption of nanocarriers under an intracellular reduction-mimicking environment. The in vitro release studies showed that DOX was released in a controlled and redox-dependent manner. MTT assays showed that DOX-loaded WPU had a high in vitro antitumor activity in both HDF noncancer cells and MCF- 7 cancer cells. In addition, it is found that the blank WPU nanocarriers are nontoxic to HDF and MCF-7 cells even at a high concentration of 2 mg/mL. Hence, nanocarriers based on disulfide labeled WPU have appeared as a new class of biocompatible and redox-degradable nanovehicle for efficient intracellular drug delivery. - Highlights: • A novel fully glutathione degradable waterborne polyurethane was developed. • The waterborne nanocarrier with disulfide bonds in both hard and soft segment were developed for redox-triggered intracellular delivery of DOX. • The polyester diol bearing disulfide bonds in the backbone was prepared by a polycondensation polymerization reaction.

  3. Electronic Submission of Labels

    Science.gov (United States)

    Pesticide registrants can provide draft and final labels to EPA electronically for our review as part of the pesticide registration process. The electronic submission of labels by registrants is voluntary but strongly encouraged.

  4. Robust Active Label Correction

    DEFF Research Database (Denmark)

    Kremer, Jan; Sha, Fei; Igel, Christian

    2018-01-01

    for the noisy data lead to different active label correction algorithms. If loss functions consider the label noise rates, these rates are estimated during learning, where importance weighting compensates for the sampling bias. We show empirically that viewing the true label as a latent variable and computing......Active label correction addresses the problem of learning from input data for which noisy labels are available (e.g., from imprecise measurements or crowd-sourcing) and each true label can be obtained at a significant cost (e.g., through additional measurements or human experts). To minimize......). To select labels for correction, we adopt the active learning strategy of maximizing the expected model change. We consider the change in regularized empirical risk functionals that use different pointwise loss functions for patterns with noisy and true labels, respectively. Different loss functions...

  5. Pesticide Product Label System

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Pesticide Product Label System (PPLS) provides a collection of pesticide product labels (Adobe PDF format) that have been approved by EPA under Section 3 of the...

  6. Semiotic labelled deductive systems

    Energy Technology Data Exchange (ETDEWEB)

    Nossum, R.T. [Imperial College of Science, Technology and Medicine, London (United Kingdom)

    1996-12-31

    We review the class of Semiotic Models put forward by Pospelov, as well as the Labelled Deductive Systems developed by Gabbay, and construct an embedding of Semiotic Models into Labelled Deductive Systems.

  7. Mental Labels and Tattoos

    Science.gov (United States)

    Hyatt, I. Ralph

    1977-01-01

    Discusses the ease with which mental labels become imprinted in our system, six basic axioms for maintaining negative mental tattoos, and psychological processes for eliminating mental tattoos and labels. (RK)

  8. Soil Fumigant Labels - Dazomet

    Science.gov (United States)

    Updated labels include new safety requirements for buffer zones and related measures. Find information from the Pesticide Product Labeling System (PPLS) for products such as Basamid G, manufactured by Amvac.

  9. Soil Fumigant Labels - Chloropicrin

    Science.gov (United States)

    Search by EPA registration number, product name, or company name, and follow the link to the Pesticide Product Label System (PPLS) for details on each fumigant. Updated labels include new safety requirements for buffer zones and related measures.

  10. Investigating Internalization and Intracellular Trafficking of GPCRs

    DEFF Research Database (Denmark)

    Foster, Simon R; Bräuner-Osborne, Hans

    2017-01-01

    for signal transduction. One of the major mechanisms for GPCR regulation involves their endocytic trafficking, which serves to internalize the receptors from the plasma membrane and thereby attenuate G protein-dependent signaling. However, there is accumulating evidence to suggest that GPCRs can signal...... independently of G proteins, as well as from intracellular compartments including endosomes. It is in this context that receptor internalization and intracellular trafficking have attracted renewed interest within the GPCR field. In this chapter, we will review the current understanding and methodologies...

  11. A Label to Regulate

    DEFF Research Database (Denmark)

    Tricoire, Aurélie; Boxenbaum, Eva; Laurent, Brice

    This paper examines the role labelling plays in the government of the contemporary economy.1Drawing on a detailed study of BBC-Effinergy, a French label for sustainable construction, we showhow the adoption and evolution of voluntary labels can be seen as emblematic of a governmentthrough experim...

  12. Labelling subway lines

    NARCIS (Netherlands)

    Garrido, M.A.; Iturriaga, C.; Márquez, A.; Portillo, J.R.; Reyes, P.; Wolff, A.; Eades, P.; Takaoka, T.

    2001-01-01

    Graphical features on map, charts, diagrams and graph drawings usually must be annotated with text labels in order to convey their meaning. In this paper we focus on a problem that arises when labeling schematized maps, e.g. for subway networks. We present algorithms for labeling points on a line

  13. Label Review Training: Module 1: Label Basics, Page 15

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about the consequences of improper labeling.

  14. Label Review Training: Module 1: Label Basics, Page 23

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Lists types of labels that do not require review.

  15. Label Review Training: Module 1: Label Basics, Page 16

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about the importance of labels and the role in enforcement.

  16. Label Review Training: Module 1: Label Basics, Page 14

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about positive effects from proper labeling.

  17. Label Review Training: Module 1: Label Basics, Page 21

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about types of labels.

  18. Label Review Training: Module 1: Label Basics, Page 22

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about what labels require review.

  19. Label Review Training: Module 1: Label Basics, Page 18

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This section discusses the types of labels.

  20. Label Review Training: Module 1: Label Basics, Page 26

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. Learn about mandatory and advisory label statements.

  1. Label Review Training: Module 1: Label Basics, Page 24

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This page is about which labels require review.

  2. Label Review Training: Module 1: Label Basics, Page 27

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. See examples of mandatory and advisory label statements.

  3. Label Review Training: Module 1: Label Basics, Page 19

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This section covers supplemental distributor labeling.

  4. Label Review Training: Module 1: Label Basics, Page 17

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. See an overview of the importance of labels.

  5. Quantitative imaging of cerebral blood flow velocity and intracellular motility using dynamic light scattering-optical coherence tomography.

    Science.gov (United States)

    Lee, Jonghwan; Radhakrishnan, Harsha; Wu, Weicheng; Daneshmand, Ali; Climov, Mihail; Ayata, Cenk; Boas, David A

    2013-06-01

    This paper describes a novel optical method for label-free quantitative imaging of cerebral blood flow (CBF) and intracellular motility (IM) in the rodent cerebral cortex. This method is based on a technique that integrates dynamic light scattering (DLS) and optical coherence tomography (OCT), named DLS-OCT. The technique measures both the axial and transverse velocities of CBF, whereas conventional Doppler OCT measures only the axial one. In addition, the technique produces a three-dimensional map of the diffusion coefficient quantifying nontranslational motions. In the DLS-OCT diffusion map, we observed high-diffusion spots, whose locations highly correspond to neuronal cell bodies and whose diffusion coefficient agreed with that of the motion of intracellular organelles reported in vitro in the literature. Therefore, the present method has enabled, for the first time to our knowledge, label-free imaging of the diffusion-like motion of intracellular organelles in vivo. As an example application, we used the method to monitor CBF and IM during a brief ischemic stroke, where we observed an induced persistent reduction in IM despite the recovery of CBF after stroke. This result supports that the IM measured in this study represent the cellular energy metabolism-related active motion of intracellular organelles rather than free diffusion of intracellular macromolecules.

  6. Labelling of leucocytes with colloidal technetium-99m-SnF2: an investigation of the labelling process by autoradiography

    International Nuclear Information System (INIS)

    Puncher, M.R.B.; Blower, P.J.

    1995-01-01

    Autoradiography of smears and frozen sections of labelled cell suspensions was used to study the distribution of radioactivity in and among blood cells labelled in either whole blood or leucocyte-rich plasma (LRP) with technetium-99m-SnF 2 colloid. The tracer proved selective for neutrophils: the labelling probability (relative to that for erythrocytes) for each cell type in LRP (mean of five samples) was: neutrophils, 9.4; lymphocytes, 3.7; monocytes, 3.0; eosinophils 1.4; erythrocytes, 1.0. When labelling was carried out in whole blood (five samples), 74.5%±8.3% of the cell-bound radioactivity was bound to erythrocytes, 13.6%±6.5% to neutrophils, and 11.9%±2.1% to lymphocytes, whereas in LRP (in which the leucocytes were only slightly outnumbered by erythrocytes), 76.5%±14.9% of radioactivity was neutrophil bound. Labelled cells in smear autoradiographs exhibited two distinct silver grain patterns, ''diffuse'', consistent with an intracellular radioactive particle (in neutrophils), and ''focal'', consistent with a cell surface-adhering particle in direct contact with the emulsion (in other leucocyte types and erythrocytes). The phagocytic inhibitor cytochalasin B neither reduced the proportion of labelled neutrophils nor altered the labelling pattern. Neutrophils were able to scavenge radioactivity from the surface of erythrocytes. It is concluded that neutrophils bind 99m Tc-SnF 2 intracellularly by phagocytosis, with high affinity; other cells become labelled at the cell surface reversibly and with lower affinity. This selectivity is high enough to permit predominantly leucocyte labelling in LRP but not in whole blood. (orig.)

  7. Practical cell labeling with magnetite cationic liposomes for cell manipulation.

    Science.gov (United States)

    Ito, Hiroshi; Nonogaki, Yurika; Kato, Ryuji; Honda, Hiroyuki

    2010-07-01

    Personalization of the cell culture process for cell therapy is an ideal strategy to obtain maximum treatment effects. In a previous report, we proposed a strategy using a magnetic manipulation device that combined a palm-top size device and a cell-labeling method using magnetite cationic liposomes (MCLs) to enable feasible personalized cell processing. In the present study, we focused on optimizing the MCL-labeling technique with respect to cell manipulation in small devices. From detailed analysis with different cell types, 4 pg/cell of MCL-label was found to be obtained immediately after mixing with MCLs, which was sufficient for magnetic cell manipulation. The amount of label increased within 24 h depending on cell type, although in all cases it decreased along with cell doubling, indicating that the labeling potential of MCLs was limited. The role of free MCLs not involved in labeling was also investigated; MCLs' role was found to be a supportive one that maximized the manipulation performance up to 100%. We also determined optimum conditions to manipulate adherent cells by MCL labeling using the MCL dispersed in trypsin solution. Considering labeling feasibility and practical performance with 10(3)-10(5) cells for personalized cell processing, we determined that 10 microg/ml of label without incubation time (0 h incubation) was the universal MCL-labeling condition. We propose the optimum specifications for a device to be combined with this method. 2010. Published by Elsevier B.V.

  8. Cationic polymers for intracellular delivery of proteins

    NARCIS (Netherlands)

    Coué, G.M.J.P.C.; Engbersen, Johannes F.J.; Samal, Sangram; Dubruel, Peter

    2015-01-01

    Many therapeutic proteins exert their pharmaceutical action inside the cytoplasm or onto individual organelles inside the cell. Intracellular protein delivery is considered to be the most direct, fastest and safest approach for curing gene-deficiency diseases, enhancing vaccination and triggering

  9. Molecular detection and characterization of sustainable intracellular ...

    African Journals Online (AJOL)

    3Centre for Biopolymer and Bio-Molecular Research, Athlone College of Technology, Republic of Ireland. ... cells was associated with the elongation of micro-villar extension that ... Keywords: Intracellular contaminants, cell cultures, bacteria culture, pre-clinical studies. ... production work involving culture technology.

  10. Spatial Cytoskeleton Organization Supports Targeted Intracellular Transport

    Science.gov (United States)

    Hafner, Anne E.; Rieger, Heiko

    2018-03-01

    The efficiency of intracellular cargo transport from specific source to target locations is strongly dependent upon molecular motor-assisted motion along the cytoskeleton. Radial transport along microtubules and lateral transport along the filaments of the actin cortex underneath the cell membrane are characteristic for cells with a centrosome. The interplay between the specific cytoskeleton organization and the motor performance realizes a spatially inhomogeneous intermittent search strategy. In order to analyze the efficiency of such intracellular search strategies we formulate a random velocity model with intermittent arrest states. We evaluate efficiency in terms of mean first passage times for three different, frequently encountered intracellular transport tasks: i) the narrow escape problem, which emerges during cargo transport to a synapse or other specific region of the cell membrane, ii) the reaction problem, which considers the binding time of two particles within the cell, and iii) the reaction-escape problem, which arises when cargo must be released at a synapse only after pairing with another particle. Our results indicate that cells are able to realize efficient search strategies for various intracellular transport tasks economically through a spatial cytoskeleton organization that involves only a narrow actin cortex rather than a cell body filled with randomly oriented actin filaments.

  11. Biological synthesis and characterization of intracellular gold ...

    Indian Academy of Sciences (India)

    In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent. Production of nanoparticles was confirmed by the colour ...

  12. Gold-carbon dots for the intracellular imaging of cancer-derived exosomes

    Science.gov (United States)

    Jiang, Xiaoyue; Zong, Shenfei; Chen, Chen; Zhang, Yizhi; Wang, Zhuyuan; Cui, Yiping

    2018-04-01

    As a novel fluorescent nanomaterial, gold-carbon quantum dots (GCDs) possess high biocompatibility and can be easily synthesized by a microwave-assisted method. Owing to their small sizes and unique optical properties, GCDs can be applied to imaging of biological targets, such as cells, exosomes and other organelles. In this study, GCDs were used for fluorescence imaging of exosomes. Tumor-specific antibodies are attached to the GCDs, forming exosome specific nanoprobes. The nanoprobes can label exosomes via immuno-reactions and thus facilitate fluorescent imaging of exosomes. When incubated with live cells, exosomes labeled with the nanoprobes can be taken up by the cells. The intracellular experiments confirmed that the majority of exosomes were endocytosed by cells and transported to lysosomes. The manner by which exosomes were taken up and the intracellular distribution of exosomes are unaffected by the GCDs. The experimental results successfully demonstrated that the presented nanoprobe can be used to study the intrinsic intracellular behavior of tumor derived exosomes. We believe that the GCDs based nanoprobe holds a great promise in the study of exosome related cellular events, such as cancer metastasis.

  13. Preparation and quality test of superparamagnetic iron oxide labeled antisense oligodeoxynucleotide probe: a preliminary study.

    Science.gov (United States)

    Wen, Ming; Li, Bibo; Ouyang, Yu; Luo, Yi; Li, Shaolin

    2009-06-01

    Molecular imaging of tumor antisense gene techniques have been applied to the study of magnetic resonance (MR) gene imaging associated with malignant tumors. In this study, we designed, synthesized, and tested a novel molecular probe, in which the antisense oligodeoxynucleotide (ASODN) was labeled with superparamagnetic iron oxide (SPIO), and its efficiency was examined by in vitro MR imaging after SK-Br-3 mammary carcinoma cell lines (oncocytes) transfection. The SPIO-labeled ASODN probe was prepared through SPIO conjugated to ASODN using a chemical cross linking method. Its morphology and size were detected by atomic force microscope, size distribution were detected by laser granulometer, the conjugating rate and biological activity were determined by high performance liquid chromatography, and the stability was determined by polyacrylamide gel electrophoresis. After that, the probes were transfected into the SK-Br-3 oncocytes, cellular iron uptake was analyzed qualitatively at light and electron microscopy and was quantified at atomic absorption spectrometry, and the signal change of the transfected cells was observed and measured using MR imaging. The morphology of the SPIO-labeled ASODN probe was mostly spherical with well-distributed scattering, and the diameters were between 25 and 40 nm (95%) by atomic force microscope and laser granulometer, the conjugating rate of the probe was 99%. Moreover, this probe kept its activity under physiological conditions and could conjugate with antisense oligodeoxynucleotide. In addition, light microscopy revealed an intracellular uptake of iron oxides in the cytosol and electron microscopic studies revealed a lysosomal deposition of iron oxides in the transfected SK-Br-3 oncocytes by antisense probes, some of them gathered stacks, and the iron content of the group of transfected SK-Br-3 oncocytes by antisense probe is significantly higher (18.37 +/- 0.42 pg) than other contrast groups, the MR imaging showed that

  14. Optimizing Nanoelectrode Arrays for Scalable Intracellular Electrophysiology.

    Science.gov (United States)

    Abbott, Jeffrey; Ye, Tianyang; Ham, Donhee; Park, Hongkun

    2018-03-20

    Electrode technology for electrophysiology has a long history of innovation, with some decisive steps including the development of the voltage-clamp measurement technique by Hodgkin and Huxley in the 1940s and the invention of the patch clamp electrode by Neher and Sakmann in the 1970s. The high-precision intracellular recording enabled by the patch clamp electrode has since been a gold standard in studying the fundamental cellular processes underlying the electrical activities of neurons and other excitable cells. One logical next step would then be to parallelize these intracellular electrodes, since simultaneous intracellular recording from a large number of cells will benefit the study of complex neuronal networks and will increase the throughput of electrophysiological screening from basic neurobiology laboratories to the pharmaceutical industry. Patch clamp electrodes, however, are not built for parallelization; as for now, only ∼10 patch measurements in parallel are possible. It has long been envisioned that nanoscale electrodes may help meet this challenge. First, nanoscale electrodes were shown to enable intracellular access. Second, because their size scale is within the normal reach of the standard top-down fabrication, the nanoelectrodes can be scaled into a large array for parallelization. Third, such a nanoelectrode array can be monolithically integrated with complementary metal-oxide semiconductor (CMOS) electronics to facilitate the large array operation and the recording of the signals from a massive number of cells. These are some of the central ideas that have motivated the research activity into nanoelectrode electrophysiology, and these past years have seen fruitful developments. This Account aims to synthesize these findings so as to provide a useful reference. Summing up from the recent studies, we will first elucidate the morphology and associated electrical properties of the interface between a nanoelectrode and a cellular membrane

  15. Promotion and Rescue of Intracellular Brucella neotomae Replication during Coinfection with Legionella pneumophila.

    Science.gov (United States)

    Kang, Yoon-Suk; Kirby, James E

    2017-05-01

    We established a new Brucella neotomae in vitro model system for study of type IV secretion system-dependent (T4SS) pathogenesis in the Brucella genus. Importantly, B. neotomae is a rodent pathogen, and unlike B. abortus , B. melitensis , and B. suis , B. neotomae has not been observed to infect humans. It therefore can be handled more facilely using biosafety level 2 practices. More particularly, using a series of novel fluorescent protein and lux operon reporter systems to differentially label pathogens and track intracellular replication, we confirmed T4SS-dependent intracellular growth of B. neotomae in macrophage cell lines. Furthermore, B. neotomae exhibited early endosomal (LAMP-1) and late endoplasmic reticulum (calreticulin)-associated phagosome maturation. These findings recapitulate prior observations for human-pathogenic Brucella spp. In addition, during coinfection experiments with Legionella pneumophila , we found that defective intracellular replication of a B. neotomae T4SS virB4 mutant was rescued and baseline levels of intracellular replication of wild-type B. neotomae were significantly stimulated by coinfection with wild-type but not T4SS mutant L. pneumophila Using confocal microscopy, it was determined that intracellular colocalization of B. neotomae and L. pneumophila was required for rescue and that colocalization came at a cost to L. pneumophila fitness. These findings were not completely expected based on known temporal and qualitative differences in the intracellular life cycles of these two pathogens. Taken together, we have developed a new system for studying in vitro Brucella pathogenesis and found a remarkable T4SS-dependent interplay between Brucella and Legionella during macrophage coinfection. Copyright © 2017 American Society for Microbiology.

  16. Estrogen receptor of primary breast cancers: evidence for intracellular proteolysis

    International Nuclear Information System (INIS)

    Maaroufi, Younes; Lacroix, Marc; Lespagnard, Laurence; Journé, Fabrice; Larsimont, Denis; Leclercq, Guy

    2000-01-01

    Iodinated oestradiol-labeled oestrogen receptor (ER) isoforms devoid of amino-terminal ABC domains represent about two-thirds of the whole receptor population detected in cytosol samples from human breast cancers. This high frequency could not be ascribed to the expression of truncated mRNAs, or to the proteolysis of the native ER peptide at the time of homogenization or assay, suggesting an intracellular proteolysis. Free amino-terminal and ligand-binding domains maintained together within oligomeric structure(s); increase of ionic strength separated them. The amino-terminal region was consistently detected in the cell nucleus by specific immunohistochemistry leading to the concept of a potential intranuclear association between ER cleavage products and/or other regulatory proteins. We previously reported that about two-thirds of [ 125 I]oestradiol-labelled cytosolic ERs from breast cancer samples eluted as low-molecular-weight isoforms (≤ 37 kDa, size-exclusion fast pressure liquid chromatography [FPLC]). These isoforms failed to adsorb strongly to hydroxylapatite at high ionic strength, a property that was ascribed to receptors devoid of amino-terminal ABC domains. In view of recent data concerning intracellular proteolysis of several transcriptional regulators, the possibility of such behaviour for ER was assessed. The clinical significance of ER measurement in breast cancer cytosols is well established; approximately 50% of ER-positive cases respond to endocrine therapy. Whether such a poor correlation is related to a high proportion of cleaved ER is a question of prime importance. Failure of routine ER assays to discriminate between full-length and cleaved receptors led us to develop an oestradiol-binding assay based on hydroxylapatite adsorption. The aims of the present study were to demonstrate that hydroxylapatite adsorption assay easily identifies cleaved cytosolic ER forms and to assess the origin of such ER forms. Breast cancer cytosols classified as

  17. LDL Receptors as Gateways for Intracellular Porphyrin Uptake

    International Nuclear Information System (INIS)

    Novick, S.; Laster, B.; Quastel, M.

    2004-01-01

    Boronated compounds are currently being studied for possible use in Boron Neutron Capture Therapy (BNCT). We found that one of these agents, BOPP (tetrakis-carborane-carboxylate, esters of 2,4-bis (a,b- dihydroxyethyl) deuteroporphyrin IX), could also be labeled with indium (In-BOPP) and, therefore, could also be used potentially to transport high Z atoms into tumor cell DNA for AET (Auger Electron Therapy). In order to assess the uptake of these agents into cells, the role of the LDL receptor in the intracellular accumulation of BOPP and In-BOPP was investigated. Pre-incubation of V-79 Chinese hamster cells in medium containing delipidized fetal bovine serum (FBS) markedly increased the subsequent uptake of intracellular boron transported by both BOPP and In-BOPP when compared with cells that had been pre-incubated with medium containing 10% normal FBS (lipidized). The increased uptake was characterized by elevated levels of receptor, and greater affinity was shown for both BOPP and In-BOPP, although less marked with the latter. Positive cooperativity was demonstrated by sigmoid saturation curves, Scatchard analysis and Hill plots. Increasing the amount of LDL in the incubation medium had a relatively small effect on the total accumulation of either indium or boron atoms inside the cell. Furthermore, chemical acetylation of LDL did not decrease the intracellular uptake of either boron or indium transported by BOPP or In-BOPP. It is thus concluded that BOPP and In-BOPP preferentially enter the cells directly by way of the LDL receptor and that only a small fraction of these molecules are transported into the cells indirectly using serum LDLs as their carriers. These data suggest a novel way of bringing greater amounts of boron and indium (and perhaps other agents) into tissues. Porphyrins can be used to transport different agents into tumor cells because they are tumor affinic molecules. Tumors express a higher number of LDL receptors than do most normal tissues

  18. A Simple Picaxe Microcontroller Pulse Source for Juxtacellular Neuronal Labelling

    Science.gov (United States)

    Verberne, Anthony J. M.

    2016-01-01

    Juxtacellular neuronal labelling is a method which allows neurophysiologists to fill physiologically-identified neurons with small positively-charged marker molecules. Labelled neurons are identified by histochemical processing of brain sections along with immunohistochemical identification of neuropeptides, neurotransmitters, neurotransmitter transporters or biosynthetic enzymes. A microcontroller-based pulser circuit and associated BASIC software script is described for incorporation into the design of a commercially-available intracellular electrometer for use in juxtacellular neuronal labelling. Printed circuit board construction has been used for reliability and reproducibility. The current design obviates the need for a separate digital pulse source and simplifies the juxtacellular neuronal labelling procedure. PMID:28952589

  19. Assessment of canine intestinal permeability, using 51Cr-labeled ethylenediaminetetraacetate

    International Nuclear Information System (INIS)

    Hall, E.J.; Batt, R.M.; Brown, A.

    1989-01-01

    The 51 Cr-labeled EDTA was validated as a suitable permeability probe in dogs for measurement of passive, unmediated diffusion across intestinal mucosa via intercellular pathways. The 51 Cr-labeled EDTA was stable in aqueous solution and did not bind to biologic tissue and fluids. After incubation of 51 Cr-labeled EDTA in isolated jejunal loops, analytic subcellular fractionation of jejunal mucosa on reorientating sucrose-density gradients was performed, and no association of 51 Cr-labeled EDTA with particulate intracellular organelles was detected. Intravenously administered 51 Cr-labeled EDTA was rapidly and completely excreted in urine. Intestinal permeability to 51 Cr-labeled EDTA after oral administration was assessed in healthy dogs. The percentage of the administered dose of 51 Cr-labeled EDTA excreted in the urine in 24 hours ranged from 2.3 to 17.6% (median, 13%)

  20. Aptamer-mediated indirect quantum dot labeling and fluorescent imaging of target proteins in living cells

    International Nuclear Information System (INIS)

    Liu, Jianbo; Zhang, Pengfei; Yang, Xiaohai; Wang, Kemin; Guo, Qiuping; Huang, Jin; Li, Wei

    2014-01-01

    Protein labeling for dynamic living cell imaging plays a significant role in basic biological research, as well as in clinical diagnostics and therapeutics. We have developed a novel strategy in which the dynamic visualization of proteins within living cells is achieved by using aptamers as mediators for indirect protein labeling of quantum dots (QDs). With this strategy, the target protein angiogenin was successfully labeled with fluorescent QDs in a minor intactness model, which was mediated by the aptamer AL6-B. Subsequent living cell imaging analyses indicated that the QDs nanoprobes were selectively bound to human umbilical vein endothelial cells, gradually internalized into the cytoplasm, and mostly localized in the lysosome organelle, indicating that the labeled protein retained high activity. Compared with traditional direct protein labeling methods, the proposed aptamer-mediated strategy is simple, inexpensive, and provides a highly selective, stable, and intact labeling platform that has shown great promise for future biomedical labeling and intracellular protein dynamic analyses. (paper)

  1. Magnetic microfluidic platform for biomedical applications using magnetic nanoparticles

    KAUST Repository

    Stipsitz, Martin

    2015-05-01

    Microfluidic platforms are well-suited for biomedical analysis and usually consist of a set of units which guarantee the manipulation, detection and recognition of bioanalyte in a reliable and flexible manner. Additionally, the use of magnetic fields for perfoming the aforementioned tasks has been steadily gainining interest. This is due to the fact that magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the diagnostic system. In combination with these applied magnetic fields, magnetic nanoparticles are used. In this paper, we present some of our most recent results in research towards a) microfluidic diagnostics using MR sensors and magnetic particles and b) single cell analysis using magnetic particles. We have successfully manipulated magnetically labeled bacteria and measured their response with integrated GMR sensors and we have also managed to separate magnetically labeled jurkat cells for single cell analysis. © 2015 Trans Tech Publications, Switzerland.

  2. Magnetic microfluidic platform for biomedical applications using magnetic nanoparticles

    KAUST Repository

    Stipsitz, Martin; Kokkinis, Georgios; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen; Cardoso, Susana; Cardoso, Filipe; Giouroudi, Ioanna

    2015-01-01

    Microfluidic platforms are well-suited for biomedical analysis and usually consist of a set of units which guarantee the manipulation, detection and recognition of bioanalyte in a reliable and flexible manner. Additionally, the use of magnetic fields for perfoming the aforementioned tasks has been steadily gainining interest. This is due to the fact that magnetic fields can be well tuned and applied either externally or from a directly integrated solution in the diagnostic system. In combination with these applied magnetic fields, magnetic nanoparticles are used. In this paper, we present some of our most recent results in research towards a) microfluidic diagnostics using MR sensors and magnetic particles and b) single cell analysis using magnetic particles. We have successfully manipulated magnetically labeled bacteria and measured their response with integrated GMR sensors and we have also managed to separate magnetically labeled jurkat cells for single cell analysis. © 2015 Trans Tech Publications, Switzerland.

  3. Biological Properties of Iron Oxide Nanoparticles for Cellular and Molecular Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Claus-Christian Glüer

    2010-12-01

    Full Text Available Superparamagnetic iron-oxide particles (SPIO are used in different ways as contrast agents for magnetic resonance imaging (MRI: Particles with high nonspecific uptake are required for unspecific labeling of phagocytic cells whereas those that target specific molecules need to have very low unspecific cellular uptake. We compared iron-oxide particles with different core materials (magnetite, maghemite, different coatings (none, dextran, carboxydextran, polystyrene and different hydrodynamic diameters (20–850 nm for internalization kinetics, release of internalized particles, toxicity, localization of particles and ability to generate contrast in MRI. Particle uptake was investigated with U118 glioma cells und human umbilical vein endothelial cells (HUVEC, which exhibit different phagocytic properties. In both cell types, the contrast agents Resovist, B102, non-coated Fe3O4 particles and microspheres were better internalized than dextran-coated Nanomag particles. SPIO uptake into the cells increased with particle/iron concentrations. Maximum intracellular accumulation of iron particles was observed between 24 h to 36 h of exposure. Most particles were retained in the cells for at least two weeks, were deeply internalized, and only few remained adsorbed at the cell surface. Internalized particles clustered in the cytosol of the cells. Furthermore, all particles showed a low toxicity. By MRI, monolayers consisting of 5000 Resovist-labeled cells could easily be visualized. Thus, for unspecific cell labeling, Resovist and microspheres show the highest potential, whereas Nanomag particles are promising contrast agents for target-specific labeling.

  4. The effect of theophylline on the labelling of nitracellular myocardial calcium with 45Ca

    International Nuclear Information System (INIS)

    Sausen, F.H.

    1973-01-01

    The effect of theophylline of varying concentration on the labelling of intracellular myocardial calcium was investigated by isotope tests with radioactively labelled Ca ( 45 Ca) in isolated, electrically stimulated left auricles of guinea pigs. The preparates were incubated in a 45 Ca solution for 60 minutes, and activity uptake and intracellular Ca concentration were determined. In contrast to earlier investigations, the extracellular Ca was removed after charge by rinsing the resting auricles with inactive, Ca ++ - and Na + -free choline chloride solution. Under controlled conditions, the intercellular Ca was found to be 45 Ca-labelled by about 36% theophylline in 'therapeutical' concentration (5 x 10 -4 g/ml) induced a significant increase of the labelled Ca fraction of 16.9% as compared to the controls. 'Toxic' theophylline concentrations, too, lead to a significantly higher absorption of 45 Ca. The interchangeable intracellular Ca fraction increased by 11.7% and 10.3% as compared to the untreated preparates. The findings are discussed with regard to earlier investigations on the influence of methylxanthines on the Ca metabolism of the heart. The author assumes that the positively inotropic effect of theophylline and the theophylline-induced contracture may be ascribed to a shift in the intracellular Ca distribution towards ionized Ca. This shift could be explained by a suppression of Ca rebinding in intracellular Ca storage places or by Ca release from these structures. (orig./AK) [de

  5. Probabilistic atlas based labeling of the cerebral vessel tree

    Science.gov (United States)

    Van de Giessen, Martijn; Janssen, Jasper P.; Brouwer, Patrick A.; Reiber, Johan H. C.; Lelieveldt, Boudewijn P. F.; Dijkstra, Jouke

    2015-03-01

    Preoperative imaging of the cerebral vessel tree is essential for planning therapy on intracranial stenoses and aneurysms. Usually, a magnetic resonance angiography (MRA) or computed tomography angiography (CTA) is acquired from which the cerebral vessel tree is segmented. Accurate analysis is helped by the labeling of the cerebral vessels, but labeling is non-trivial due to anatomical topological variability and missing branches due to acquisition issues. In recent literature, labeling the cerebral vasculature around the Circle of Willis has mainly been approached as a graph-based problem. The most successful method, however, requires the definition of all possible permutations of missing vessels, which limits application to subsets of the tree and ignores spatial information about the vessel locations. This research aims to perform labeling using probabilistic atlases that model spatial vessel and label likelihoods. A cerebral vessel tree is aligned to a probabilistic atlas and subsequently each vessel is labeled by computing the maximum label likelihood per segment from label-specific atlases. The proposed method was validated on 25 segmented cerebral vessel trees. Labeling accuracies were close to 100% for large vessels, but dropped to 50-60% for small vessels that were only present in less than 50% of the set. With this work we showed that using solely spatial information of the vessel labels, vessel segments from stable vessels (>50% presence) were reliably classified. This spatial information will form the basis for a future labeling strategy with a very loose topological model.

  6. Labelling of equipment dispensers.

    Science.gov (United States)

    Gray, D C

    1993-01-01

    A new labelling system for use on medical equipment dispensers is tested. This system uses one of the objects stored in each unit of the dispenser as the 'label', by attaching it to the front of the dispenser with tape. The new system was compared to conventional written labelling by timing subjects asked to select items from two dispensers. The new system was 27% quicker than the conventional system. Images Fig. 1 PMID:8110335

  7. Deuterium labeled cannabinoids

    International Nuclear Information System (INIS)

    Driessen, R.A.

    1979-01-01

    Complex reactions involving ring opening, ring closure and rearrangements hamper complete understanding of the fragmentation processes in the mass spectrometric fragmentation patterns of cannabinoids. Specifically labelled compounds are very powerful tools for obtaining more insight into fragmentation mechanisms and ion structures and therefore the synthesis of specifically deuterated cannabinoids was undertaken. For this, it was necessary to investigate the preparation of cannabinoids, appropriately functionalized for specific introduction of deuterium atom labels. The results of mass spectrometry with these labelled cannabinoids are described. (Auth.)

  8. Dynamics of gradient formation by intracellular shuttling

    Energy Technology Data Exchange (ETDEWEB)

    Berezhkovskii, Alexander M. [Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892 (United States); Shvartsman, Stanislav Y. [Department of Chemical and Biological Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544 (United States)

    2015-08-21

    A number of important cellular functions rely on the formation of intracellular protein concentration gradients. Experimental studies discovered a number of mechanisms for the formation of such gradients. One of the mechanisms relies on the intracellular shuttling of a protein that interconverts between the two states with different diffusivities, under the action of two enzymes, one of which is localized to the plasma membrane, whereas the second is uniformly distributed in the cytoplasm. Recent work reported an analytical solution for the steady state gradient in this mechanism, obtained in the framework of a one-dimensional reaction-diffusion model. Here, we study the dynamics in this model and derive analytical expressions for the Laplace transforms of the time-dependent concentration profiles in terms of elementary transcendental functions. Inverting these transforms numerically, one can obtain time-dependent concentration profiles of the two forms of the protein.

  9. Leishmania hijacking of the macrophage intracellular compartments.

    Science.gov (United States)

    Liévin-Le Moal, Vanessa; Loiseau, Philippe M

    2016-02-01

    Leishmania spp., transmitted to humans by the bite of the sandfly vector, are responsible for the three major forms of leishmaniasis, cutaneous, diffuse mucocutaneous and visceral. Leishmania spp. interact with membrane receptors of neutrophils and macrophages. In macrophages, the parasite is internalized within a parasitophorous vacuole and engages in a particular intracellular lifestyle in which the flagellated, motile Leishmania promastigote metacyclic form differentiates into non-motile, metacyclic amastigote form. This phenomenon is induced by Leishmania-triggered events leading to the fusion of the parasitophorous vacuole with vesicular members of the host cell endocytic pathway including recycling endosomes, late endosomes and the endoplasmic reticulum. Maturation of the parasitophorous vacuole leads to the intracellular proliferation of the Leishmania amastigote forms by acquisition of host cell nutrients while escaping host defense responses. © 2015 FEBS.

  10. Reduction of intracellular glutathione content and radiosensitivity

    International Nuclear Information System (INIS)

    Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

    1986-05-01

    The intracellular glutathione (GSH) content in HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulfoximine (BSO) or diethyl maleate (DEM). Clonogenicity, single strand DNA breaks (ssb) and double strand DNA breaks (dsb) were used as criteria for radiation induced damage after X- or γ irradiation. In survival experiments DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the OER was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (Auth.)

  11. Reduction of intracellular glutathione content and radiosensitivity

    International Nuclear Information System (INIS)

    Vos, O.; Schans, G.P. van der; Roos-Verheij, W.S.D.

    1986-01-01

    The intracellular glutathione (GSH) content of HeLa, CHO and V79 cells was reduced by incubating the cells in growth medium containing buthionine sulphoximine or diethyl maleate (DEM). Clonogenicity, single-strand DNA breaks (ssb) and double-strand DNA breaks (dsb) were used as criteria for radiation-induced damage after X- or γ-irradiation. In survival experiments, DEM gave a slightly larger sensitization although it gave a smaller reduction of the intracellular GSH. In general, sensitization was larger for dsb than for ssb, also the reduction of the o.e.r. was generally larger for dsb than for ssb. This may be due to the higher dose rate in case of dsb experiments resulting in a higher rate of radiochemical oxygen consumption. In general, no effect was found on post-irradiation repair of ssb and dsb. (author)

  12. Intracellular mechanisms of solar water disinfection

    Science.gov (United States)

    Castro-Alférez, María; Polo-López, María Inmaculada; Fernández-Ibáñez, Pilar

    2016-12-01

    Solar water disinfection (SODIS) is a zero-cost intervention measure to disinfect drinking water in areas of poor access to improved water sources, used by more than 6 million people in the world. The bactericidal action of solar radiation in water has been widely proven, nevertheless the causes for this remain still unclear. Scientific literature points out that generation of reactive oxygen species (ROS) inside microorganisms promoted by solar light absorption is the main reason. For the first time, this work reports on the experimental measurement of accumulated intracellular ROS in E. coli during solar irradiation. For this experimental achievement, a modified protocol based on the fluorescent probe dichlorodihydrofluorescein diacetate (DCFH-DA), widely used for oxidative stress in eukaryotic cells, has been tested and validated for E. coli. Our results demonstrate that ROS and their accumulated oxidative damages at intracellular level are key in solar water disinfection.

  13. Effective sample labeling

    International Nuclear Information System (INIS)

    Rieger, J.T.; Bryce, R.W.

    1990-01-01

    Ground-water samples collected for hazardous-waste and radiological monitoring have come under strict regulatory and quality assurance requirements as a result of laws such as the Resource Conservation and Recovery Act. To comply with these laws, the labeling system used to identify environmental samples had to be upgraded to ensure proper handling and to protect collection personnel from exposure to sample contaminants and sample preservatives. The sample label now used as the Pacific Northwest Laboratory is a complete sample document. In the event other paperwork on a labeled sample were lost, the necessary information could be found on the label

  14. Intracellular serpins, firewalls and tissue necrosis.

    Science.gov (United States)

    Marciniak, Stefan J; Lomas, David A

    2008-02-01

    Luke and colleagues have recently attributed a new role to a member of the serpin superfamily of serine proteinase inhibitors. They have used Caenorhabditis elegans to show that an intracellular serpin is crucial for maintaining lysosomal integrity. We examine the role of this firewall in preventing necrosis and attempt to integrate this with current theories of stress-induced protein degradation. We discuss how mutant serpins cause disease either through polymerization or now, perhaps, by unleashing necrosis.

  15. Fluorescent nanoparticles for intracellular sensing: A review

    International Nuclear Information System (INIS)

    Ruedas-Rama, Maria J.; Walters, Jamie D.; Orte, Angel; Hall, Elizabeth A.H.

    2012-01-01

    Highlights: ► Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. ► Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. ► Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

  16. Fluorescent nanoparticles for intracellular sensing: A review

    Energy Technology Data Exchange (ETDEWEB)

    Ruedas-Rama, Maria J., E-mail: mjruedas@ugr.esmailto [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Walters, Jamie D. [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, UK CB2 1QT (United Kingdom); Orte, Angel [Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Campus Cartuja, 18071, Granada (Spain); Hall, Elizabeth A.H., E-mail: lisa.hall@biotech.cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT (United Kingdom)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer Analytical applications of fluorescent nanoparticles (NPs) in intracellular sensing. Black-Right-Pointing-Pointer Critical review on performance of QDots, metal NPs, silica NPs, and polymer NPs. Black-Right-Pointing-Pointer Highlighted potential of fluorescence lifetime imaging microscopy (FLIM). - Abstract: Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy.

  17. Intracellular Cholesterol Trafficking and Impact in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Fabian Arenas

    2017-11-01

    Full Text Available Cholesterol is a critical component of membrane bilayers where it plays key structural and functional roles by regulating the activity of diverse signaling platforms and pathways. Particularly enriched in brain, cholesterol homeostasis in this organ is singular with respect to other tissues and exhibits a heterogeneous regulation in distinct brain cell populations. Due to the key role of cholesterol in brain physiology and function, alterations in cholesterol homeostasis and levels have been linked to brain diseases and neurodegeneration. In the case of Alzheimer disease (AD, however, this association remains unclear with evidence indicating that either increased or decreased total brain cholesterol levels contribute to this major neurodegenerative disease. Here, rather than analyzing the role of total cholesterol levels in neurodegeneration, we focus on the contribution of intracellular cholesterol pools, particularly in endolysosomes and mitochondria through its trafficking via specialized membrane domains delineated by the contacts between endoplasmic reticulum and mitochondria, in the onset of prevalent neurodegenerative diseases such as AD, Parkinson disease, and Huntington disease as well as in lysosomal disorders like Niemann-Pick type C disease. We dissect molecular events associated with intracellular cholesterol accumulation, especially in mitochondria, an event that results in impaired mitochondrial antioxidant defense and function. A better understanding of the mechanisms involved in the distribution of cholesterol in intracellular compartments may shed light on the role of cholesterol homeostasis disruption in neurodegeneration and may pave the way for specific intervention opportunities.

  18. A bacteriophage endolysin that eliminates intracellular streptococci

    Science.gov (United States)

    Shen, Yang; Barros, Marilia; Vennemann, Tarek; Gallagher, D Travis; Yin, Yizhou; Linden, Sara B; Heselpoth, Ryan D; Spencer, Dennis J; Donovan, David M; Moult, John; Fischetti, Vincent A; Heinrich, Frank; Lösche, Mathias; Nelson, Daniel C

    2016-01-01

    PlyC, a bacteriophage-encoded endolysin, lyses Streptococcus pyogenes (Spy) on contact. Here, we demonstrate that PlyC is a potent agent for controlling intracellular Spy that often underlies refractory infections. We show that the PlyC holoenzyme, mediated by its PlyCB subunit, crosses epithelial cell membranes and clears intracellular Spy in a dose-dependent manner. Quantitative studies using model membranes establish that PlyCB interacts strongly with phosphatidylserine (PS), whereas its interaction with other lipids is weak, suggesting specificity for PS as its cellular receptor. Neutron reflection further substantiates that PlyC penetrates bilayers above a PS threshold concentration. Crystallography and docking studies identify key residues that mediate PlyCB–PS interactions, which are validated by site-directed mutagenesis. This is the first report that a native endolysin can traverse epithelial membranes, thus substantiating the potential of PlyC as an antimicrobial for Spy in the extracellular and intracellular milieu and as a scaffold for engineering other functionalities. DOI: http://dx.doi.org/10.7554/eLife.13152.001 PMID:26978792

  19. Evaluating nanoparticle sensor design for intracellular pH measurements.

    Science.gov (United States)

    Benjaminsen, Rikke V; Sun, Honghao; Henriksen, Jonas R; Christensen, Nynne M; Almdal, Kristoffer; Andresen, Thomas L

    2011-07-26

    Particle-based nanosensors have over the past decade been designed for optical fluorescent-based ratiometric measurements of pH in living cells. However, quantitative and time-resolved intracellular measurements of pH in endosomes and lysosomes using particle nanosensors are challenging, and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time-resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle-based sensor systems that are internalized by endocytosis and elucidated important factors in nanosensor design that should be considered in future development of new sensors. From our experiments it is clear that it is highly important to use sensors that have a broad measurement range, as erroneous quantification of pH is an unfortunate result when measuring pH too close to the limit of the sensitive range of the sensors. Triple-labeled nanosensors with a pH measurement range of 3.2-7.0, which was synthesized by adding two pH-sensitive fluorophores with different pK(a) to each sensor, seem to be a solution to some of the earlier problems found when measuring pH in the endosome-lysosome pathway.

  20. Intracellular fate of Ureaplasma parvum entrapped by host cellular autophagy.

    Science.gov (United States)

    Nishiumi, Fumiko; Ogawa, Michinaga; Nakura, Yukiko; Hamada, Yusuke; Nakayama, Masahiro; Mitobe, Jiro; Hiraide, Atsushi; Sakai, Norio; Takeuchi, Makoto; Yoshimori, Tamotsu; Yanagihara, Itaru

    2017-06-01

    Genital mycoplasmas, including Ureaplasma spp., are among the smallest human pathogenic bacteria and are associated with preterm birth. Electron microscopic observation of U. parvum showed that these prokaryotes have a regular, spherical shape with a mean diameter of 146 nm. U. parvum was internalized into HeLa cells by clathrin-mediated endocytosis and survived for at least 14 days around the perinuclear region. Intracellular U. parvum reached endosomes in HeLa cells labeled with EEA1, Rab7, and LAMP-1 within 1 to 3 hr. After 3 hr of infection, U. parvum induced the cytosolic accumulation of galectin-3 and was subsequently entrapped by the autophagy marker LC3. However, when using atg7 -/- MEF cells, autophagy was inadequate for the complete elimination of U. parvum in HeLa cells. U. parvum also colocalized with the recycling endosome marker Rab11. Furthermore, the exosomes purified from infected HeLa cell culture medium included U. parvum. In these purified exosomes ureaplasma lipoprotein multiple banded antigen, host cellular annexin A2, CD9, and CD63 were detected. This research has successfully shown that Ureaplasma spp. utilize the host cellular membrane compartments possibly to evade the host immune system. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  1. Dynamic map labeling.

    Science.gov (United States)

    Been, Ken; Daiches, Eli; Yap, Chee

    2006-01-01

    We address the problem of filtering, selecting and placing labels on a dynamic map, which is characterized by continuous zooming and panning capabilities. This consists of two interrelated issues. The first is to avoid label popping and other artifacts that cause confusion and interrupt navigation, and the second is to label at interactive speed. In most formulations the static map labeling problem is NP-hard, and a fast approximation might have O(nlogn) complexity. Even this is too slow during interaction, when the number of labels shown can be several orders of magnitude less than the number in the map. In this paper we introduce a set of desiderata for "consistent" dynamic map labeling, which has qualities desirable for navigation. We develop a new framework for dynamic labeling that achieves the desiderata and allows for fast interactive display by moving all of the selection and placement decisions into the preprocessing phase. This framework is general enough to accommodate a variety of selection and placement algorithms. It does not appear possible to achieve our desiderata using previous frameworks. Prior to this paper, there were no formal models of dynamic maps or of dynamic labels; our paper introduces both. We formulate a general optimization problem for dynamic map labeling and give a solution to a simple version of the problem. The simple version is based on label priorities and a versatile and intuitive class of dynamic label placements we call "invariant point placements". Despite these restrictions, our approach gives a useful and practical solution. Our implementation is incorporated into the G-Vis system which is a full-detail dynamic map of the continental USA. This demo is available through any browser.

  2. Immunomicroscopic localization of aminopeptidase N in the pig enterocyte. Implications for the route of intracellular transport

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Sjöström, H; Norén, Ove

    1987-01-01

    The subcellular localization of aminopeptidase N (EC 3.4.11.2) in the pig enterocyte was investigated by immunofluorescence and immunoelectron microscopy (immunogold staining). By indirect immunofluorescence on either frozen or paraffin-embedded sections, a very intense staining in the microvillar....... Labelling was demonstrated in the Golgi apparatus and in a minor fraction of the intracellular smooth vesicles positioned between the Golgi apparatus and the microvillar membrane. These observations are compatible with the view that newly synthesized aminopeptidase N is delivered directly to the microvillar...

  3. Label-acquired magnetorotation for biosensing: An asynchronous rotation assay

    International Nuclear Information System (INIS)

    Hecht, Ariel; Kinnunen, Paivo; McNaughton, Brandon; Kopelman, Raoul

    2011-01-01

    This paper presents a novel application of magnetic particles for biosensing, called label-acquired magnetorotation (LAM). This method is based on a combination of the traditional sandwich assay format with the asynchronous magnetic bead rotation (AMBR) method. In label-acquired magnetorotation, an analyte facilitates the binding of a magnetic label bead to a nonmagnetic solid phase sphere, forming a sandwich complex. The sandwich complex is then placed in a rotating magnetic field, where the rotational frequency of the sandwich complex is a function of the amount of analyte attached to the surface of the sphere. Here, we use streptavidin-coated beads and biotin-coated particles as analyte mimics, to be replaced by proteins and other biological targets in future work. We show this sensing method to have a dynamic range of two orders of magnitude.

  4. Labeling of mesenchymal stem cells for MRI with single-cell sensitivity

    Directory of Open Access Journals (Sweden)

    Ariza de Schellenberger A

    2016-04-01

    Full Text Available Angela Ariza de Schellenberger,1 Harald Kratz,1 Tracy D Farr,2,3 Norbert Löwa,4 Ralf Hauptmann,1 Susanne Wagner,1 Matthias Taupitz,1 Jörg Schnorr,1 Eyk A Schellenberger1 1Department of Radiology, 2Department of Experimental Neurology, Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany; 3School of Life Sciences, University of Nottingham, Medical School, Nottingham, UK; 4Department of Biomagnetic Signals, Physikalisch-Technische Bundesanstalt Berlin, Berlin, Germany Abstract: Sensitive cell detection by magnetic resonance imaging (MRI is an important tool for the development of cell therapies. However, clinically approved contrast agents that allow single-cell detection are currently not available. Therefore, we compared very small iron oxide nanoparticles (VSOP and new multicore carboxymethyl dextran-coated iron oxide nanoparticles (multicore particles, MCP designed by our department for magnetic particle imaging (MPI with discontinued Resovist® regarding their suitability for detection of single mesenchymal stem cells (MSC by MRI. We achieved an average intracellular nanoparticle (NP load of >10 pg Fe per cell without the use of transfection agents. NP loading did not lead to significantly different results in proliferation, colony formation, and multilineage in vitro differentiation assays in comparison to controls. MRI allowed single-cell detection using VSOP, MCP, and Resovist® in conjunction with high-resolution T2*-weighted imaging at 7 T with postprocessing of phase images in agarose cell phantoms and in vivo after delivery of 2,000 NP-labeled MSC into mouse brains via the left carotid artery. With optimized labeling conditions, a detection rate of ~45% was achieved; however, the experiments were limited by nonhomogeneous NP loading of the MSC population. Attempts should be made to achieve better cell separation for homogeneous NP loading and to thus improve NP

  5. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  6. Polycaprolactone/maltodextrin nanocarrier for intracellular drug delivery: formulation, uptake mechanism, internalization kinetics, and subcellular localization.

    Science.gov (United States)

    Korang-Yeboah, Maxwell; Gorantla, Yamini; Paulos, Simon A; Sharma, Pankaj; Chaudhary, Jaideep; Palaniappan, Ravi

    2015-01-01

    Prostate cancer (PCa) disease progression is associated with significant changes in intracellular and extracellular proteins, intracellular signaling mechanism, and cancer cell phenotype. These changes may have direct impact on the cellular interactions with nanocarriers; hence, there is the need for a much-detailed understanding, as nanocarrier cellular internalization and intracellular sorting mechanism correlate directly with bioavailability and clinical efficacy. In this study, we report the differences in the rate and mechanism of cellular internalization of a biocompatible polycaprolactone (PCL)/maltodextrin (MD) nanocarrier system for intracellular drug delivery in LNCaP, PC3, and DU145 PCa cell lines. PCL/MD nanocarriers were designed and characterized. PCL/MD nanocarriers significantly increased the intracellular concentration of coumarin-6 and fluorescein isothiocyanate-labeled bovine serum albumin, a model hydrophobic and large molecule, respectively. Fluorescence microscopy and flow cytometry analysis revealed rapid internalization of the nanocarrier. The extent of nanocarrier cellular internalization correlated directly with cell line aggressiveness. PCL/MD internalization was highest in PC3 followed by DU145 and LNCaP, respectively. Uptake in all PCa cell lines was metabolically dependent. Extraction of endogenous cholesterol by methyl-β-cyclodextrin reduced uptake by 75%±4.53% in PC3, 64%±6.01% in LNCaP, and 50%±4.50% in DU145, indicating the involvement of endogenous cholesterol in cellular internalization. Internalization of the nanocarrier in LNCaP was mediated mainly by macropinocytosis and clathrin-independent pathways, while internalization in PC3 and DU145 involved clathrin-mediated endocytosis, clathrin-independent pathways, and macropinocytosis. Fluorescence microscopy showed a very diffused and non-compartmentalized subcellular localization of the PCL/MD nanocarriers with possible intranuclear localization and minor colocalization in

  7. Edge colouring by total labellings

    DEFF Research Database (Denmark)

    Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

    2010-01-01

    We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

  8. Radioiodine and its labelled compounds

    International Nuclear Information System (INIS)

    Robles, Ana Maria

    1994-01-01

    Chemical characteristics and their nuclear characteristics, types of labelled molecules,labelling procedures, direct labelling with various oxidizing agents, indirect labelling with various conjugates attached to protein molecules, purification and quality control. Iodination damage.Safe handling of labelling procedures with iodine radioisotopes.Bibliography

  9. 'Naturemade' -- a new label

    International Nuclear Information System (INIS)

    Niederhaeusern, A.

    2001-01-01

    This short article discusses the introduction of the 'Naturemade' two-level labelling scheme in the Swiss electricity market, which is to help provide transparency in the market for green power and promote the building of facilities for its production. In the form of an interview with the CEO of Swissolar and the president of Greenpeace Switzerland, the pros and contras of these labels are discussed. In particular, the interview partners' opinions on the possible misuse of the less stringent label and the influence of the labels on the construction of new installations for the generation of electricity from renewable sources are presented. The basic principles of the promotional model behind the labels are listed

  10. Label Review Training: Module 1: Label Basics, Page 25

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review: clarity, accuracy, consistency with EPA policy, and enforceability.

  11. Label Review Training: Module 1: Label Basics, Page 29

    Science.gov (United States)

    This module of the pesticide label review training provides basic information about pesticides, their labeling and regulation, and the core principles of pesticide label review. This page is a quiz on Module 1.

  12. Azithromycin effectiveness against intracellular infections of Francisella

    Directory of Open Access Journals (Sweden)

    Mann Barbara J

    2010-04-01

    Full Text Available Abstract Background Macrolide antibiotics are commonly administered for bacterial respiratory illnesses. Azithromycin (Az is especially noted for extremely high intracellular concentrations achieved within macrophages which is far greater than the serum concentration. Clinical strains of Type B Francisella (F. tularensis have been reported to be resistant to Az, however our laboratory Francisella strains were found to be sensitive. We hypothesized that different strains/species of Francisella (including Type A may have different susceptibilities to Az, a widely used and well-tolerated antibiotic. Results In vitro susceptibility testing of Az confirmed that F. tularensis subsp. holarctica Live Vaccine Strain (LVS (Type B was not sensitive while F. philomiragia, F. novicida, and Type A F. tularensis (NIH B38 and Schu S4 strain were susceptible. In J774A.1 mouse macrophage cells infected with F. philomiragia, F. novicida, and F. tularensis LVS, 5 μg/ml Az applied extracellularly eliminated intracellular Francisella infections. A concentration of 25 μg/ml Az was required for Francisella-infected A549 human lung epithelial cells, suggesting that macrophages are more effective at concentrating Az than epithelial cells. Mutants of RND efflux components (tolC and ftlC in F. novicida demonstrated less sensitivity to Az by MIC than the parental strain, but the tolC disc-inhibition assay demonstrated increased sensitivity, indicating a complex role for the outer-membrane transporter. Mutants of acrA and acrB mutants were less sensitive to Az than the parental strain, suggesting that AcrAB is not critical for the efflux of Az in F. novicida. In contrast, F. tularensis Schu S4 mutants ΔacrB and ΔacrA were more sensitive than the parental strain, indicating that the AcrAB may be important for Az efflux in F. tularensis Schu S4. F. novicida LPS O-antigen mutants (wbtN, wbtE, wbtQ and wbtA were found to be less sensitive in vitro to Az compared to the wild

  13. Soil Fumigant Labels - Methyl Bromide

    Science.gov (United States)

    Search soil fumigant pesticide labels by EPA registration number, product name, or company, and follow the link to The Pesticide Product Label System (PPLS) for details. Updated labels include new safety requirements for buffer zones and related measures.

  14. Further studies on the effect of chloroquine on the uptake, metabolism and intracellular translocation of [35S]cystine in cystinotic fibroblasts.

    Science.gov (United States)

    Danpure, C J; Jennings, P R; Fyfe, D A

    1986-03-14

    The present study uses the lysosomotropic drug chloroquine to investigate the mechanisms by which exogenous [35S]cystine is able to label the intracellular (intralysosomal) cystine pool(s) in cystinotic fibroblasts. When cystinotic fibroblasts were labelled for short periods of time (8 h or less), chloroquine (20 microM) inhibited the labelling of the intracellular cystine pool(s). However, when the cells were labelled for longer periods of time (24 h or more) chloroquine stimulated the labelling of the intracellular cystine pool(s). The short-term effect was selectively abolished when the cells were washed free of chloroquine, while the long-term effect was selectively abolished when the medium was depleted of cystine. Two routes of translocation of exogenous cystine to the lysosomes could be defined. One route was fast, had a low capacity, was inhibited by chloroquine and increased with increasing medium pH, while the other route was slow, had a high capacity, was stimulated by chloroquine and was more active at low pH. The former pathway probably consisted of plasma membrane transport of cystine into the cytosol followed by direct or indirect transport into the lysosomes. The latter route possibly consisted of pinocytosis with fusion of the cystine-containing pinosomes with lysosomes.

  15. Radioactive labelled orgotein

    International Nuclear Information System (INIS)

    1980-01-01

    The preparation and use of radioactively labelled orgotein, i.e. water-soluble protein congeners in pure, injectable form, is described. This radiopharmaceutical is useful in scintigraphy, especially for visualization of the kidneys where the orgotein is rapidly concentrated. Details of the processes for labelling bovine orgotein with sup(99m)Tc, 60 Co, 125 I or 131 I are specified. The pharmaceutical preparation of the labelled orgotein for intravenous and parenteral administration is also described. Examples using either sup(99m)TC or 125 I-orgotein in scintiscanning dogs' kidneys are given. (UK)

  16. On Online Labeling with Polynomially Many Labels

    DEFF Research Database (Denmark)

    Babka, Martin; Bulánek, Jan; Cunat, Vladimír

    2012-01-01

    be necessary to change the labels of some items; such changes may be done at any time at unit cost for each change. The goal is to minimize the total cost. An alternative formulation of this problem is the file maintenance problem, in which the items, instead of being labeled, are maintained in sorted order...... in an array of length m, and we pay unit cost for moving an item. For the case m = cn for constant c > 1, there are known algorithms that use at most O(n log(n)2) relabelings in total [9], and it was shown recently that this is asymptotically optimal [1]. For the case of m = θ(nC) for C > 1, algorithms...

  17. The effect of sodium bicarbonate on intracellular pH using {sup 31}P-MR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Kazuya; Kashiwagi, Shiro; Ito, Haruhide [Yamaguchi Univ., Ube (Japan). School of Medicine; Yamashita, Tetsuo; Kitahara, Tetsuhiro; Nakayama, Naoto; Saito, Kennichi

    1997-03-01

    This report deals with the effects of sodium bicarbonate on the intracellular pH of the brain and cerebral blood flow (CBF); five normal volunteers were studied. Intracellular pH and CBF were measured by phosphorus 31 magnetic resonance spectroscopy ({sup 31}P-MRS) and stable xenon computed tomography (Xe-CT), respectively. Each individual received 7% sodium bicarbonate (3.5 ml/kg body weight), infused intravenously over a 15-min period. Intracellular pH, CBF, and physiological parameters were determined before and after the injection. Intracellular pH was significantly decreased and CBF was increased. Among the physiological parameters, the hematocrit was significantly decreased and arterial pressure of carbon dioxide (PaCO{sub 2}), increased. These results suggest that increasing CO{sub 2} contributes to the decrease in intracellular pH. In conclusion, three factors increase CBF during the administration of sodium bicarbonate to humans: arterial dilatation in response to carbon dioxide; decrease of the hematocrit, and intracellular cerebral acidosis. (author)

  18. Clinical applications of cells labelling

    International Nuclear Information System (INIS)

    Gonzalez, B.M.

    1994-01-01

    Blood cells labelled with radionuclides are reviewed and main applications are described. Red blood cell labelling by both random and specific principle. A table with most important clinical uses, 99mTc labelling of RBC are described pre tinning and in vivo reduction of Tc, in vitro labelling and administration of labelled RBC and in vivo modified technique. Labelled leucocytes with several 99mTc-complex radiopharmaceuticals by in vitro technique and specific monoclonal s for white cells(neutrofiles). Labelled platelets for clinical use and research by in vitro technique and in vivo labelling

  19. Intracellular bacteria: the origin of dinoflagellate toxicity.

    Science.gov (United States)

    Silva, E S

    1990-01-01

    Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

  20. Fluorescent nanoparticles for intracellular sensing: a review.

    Science.gov (United States)

    Ruedas-Rama, Maria J; Walters, Jamie D; Orte, Angel; Hall, Elizabeth A H

    2012-11-02

    Fluorescent nanoparticles (NPs), including semiconductor NPs (Quantum Dots), metal NPs, silica NPs, polymer NPs, etc., have been a major focus of research and development during the past decade. The fluorescent nanoparticles show unique chemical and optical properties, such as brighter fluorescence, higher photostability and higher biocompatibility, compared to classical fluorescent organic dyes. Moreover, the nanoparticles can also act as multivalent scaffolds for the realization of supramolecular assemblies, since their high surface to volume ratio allow distinct spatial domains to be functionalized, which can provide a versatile synthetic platform for the implementation of different sensing schemes. Their excellent properties make them one of the most useful tools that chemistry has supplied to biomedical research, enabling the intracellular monitoring of many different species for medical and biological purposes. In this review, we focus on the developments and analytical applications of fluorescent nanoparticles in chemical and biological sensing within the intracellular environment. The review also points out the great potential of fluorescent NPs for fluorescence lifetime imaging microscopy (FLIM). Finally, we also give an overview of the current methods for delivering of fluorescent NPs into cells, where critically examine the benefits and liabilities of each strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Mechanisms of cellular invasion by intracellular parasites.

    Science.gov (United States)

    Walker, Dawn M; Oghumu, Steve; Gupta, Gaurav; McGwire, Bradford S; Drew, Mark E; Satoskar, Abhay R

    2014-04-01

    Numerous disease-causing parasites must invade host cells in order to prosper. Collectively, such pathogens are responsible for a staggering amount of human sickness and death throughout the world. Leishmaniasis, Chagas disease, toxoplasmosis, and malaria are neglected diseases and therefore are linked to socio-economical and geographical factors, affecting well-over half the world's population. Such obligate intracellular parasites have co-evolved with humans to establish a complexity of specific molecular parasite-host cell interactions, forming the basis of the parasite's cellular tropism. They make use of such interactions to invade host cells as a means to migrate through various tissues, to evade the host immune system, and to undergo intracellular replication. These cellular migration and invasion events are absolutely essential for the completion of the lifecycles of these parasites and lead to their for disease pathogenesis. This review is an overview of the molecular mechanisms of protozoan parasite invasion of host cells and discussion of therapeutic strategies, which could be developed by targeting these invasion pathways. Specifically, we focus on four species of protozoan parasites Leishmania, Trypanosoma cruzi, Plasmodium, and Toxoplasma, which are responsible for significant morbidity and mortality.

  2. [Intracellular signaling mechanisms in thyroid cancer].

    Science.gov (United States)

    Mondragón-Terán, Paul; López-Hernández, Luz Berenice; Gutiérrez-Salinas, José; Suárez-Cuenca, Juan Antonio; Luna-Ceballos, Rosa Isela; Erazo Valle-Solís, Aura

    2016-01-01

    Thyroid cancer is the most common malignancy of the endocrine system, the papillary variant accounts for 80-90% of all diagnosed cases. In the development of papillary thyroid cancer, BRAF and RAS genes are mainly affected, resulting in a modification of the system of intracellular signaling proteins known as «protein kinase mitogen-activated» (MAPK) which consist of «modules» of internal signaling proteins (Receptor/Ras/Raf/MEK/ERK) from the cell membrane to the nucleus. In thyroid cancer, these signanling proteins regulate diverse cellular processes such as differentiation, growth, development and apoptosis. MAPK play an important role in the pathogenesis of thyroid cancer as they are used as molecular biomarkers for diagnostic, prognostic and as possible therapeutic molecular targets. Mutations in BRAF gene have been correlated with poor response to treatment with traditional chemotherapy and as an indicator of poor prognosis. To review the molecular mechanisms involved in intracellular signaling of BRAF and RAS genes in thyroid cancer. Molecular therapy research is in progress for this type of cancer as new molecules have been developed in order to inhibit any of the components of the signaling pathway (RET/PTC)/Ras/Raf/MEK/ERK; with special emphasis on the (RET/PTC)/Ras/Raf section, which is a major effector of ERK pathway. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  3. Metabolic responses of primary and transformed cells to intracellular Listeria monocytogenes.

    Directory of Open Access Journals (Sweden)

    Nadine Gillmaier

    Full Text Available The metabolic response of host cells, in particular of primary mammalian cells, to bacterial infections is poorly understood. Here, we compare the carbon metabolism of primary mouse macrophages and of established J774A.1 cells upon Listeria monocytogenes infection using (13C-labelled glucose or glutamine as carbon tracers. The (13C-profiles of protein-derived amino acids from labelled host cells and intracellular L. monocytogenes identified active metabolic pathways in the different cell types. In the primary cells, infection with live L. monocytogenes increased glycolytic activity and enhanced flux of pyruvate into the TCA cycle via pyruvate dehydrogenase and pyruvate carboxylase, while in J774A.1 cells the already high glycolytic and glutaminolytic activities hardly changed upon infection. The carbon metabolism of intracellular L. monocytogenes was similar in both host cells. Taken together, the data suggest that efficient listerial replication in the cytosol of the host cells mainly depends on the glycolytic activity of the hosts.

  4. FDA Online Label Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The drug labels and other drug-specific information on this Web site represent the most recent drug listing information companies have submitted to the Food and Drug...

  5. Figuring Out Food Labels

    Science.gov (United States)

    ... It's also displayed in grocery stores near fresh foods, like fruits, vegetables, and fish. The nutrition facts label includes: a ... found in citrus fruits, other fruits, and some vegetables. Food companies might also list the amounts of other ...

  6. Energy efficiency labelling

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    This research assesses the likely effects on UK consumers of the proposed EEC energy-efficiency labeling scheme. Unless (or until) an energy-labeling scheme is introduced, it is impossible to do more than postulate its likely effects on consumer behavior. This report shows that there are indeed significant differences in energy consumption between different brands and models of the same appliance of which consumers are unaware. Further, the report suggests that, if a readily intelligible energy-labeling scheme were introduced, it would provide useful information that consumers currently lack; and that, if this information were successfully presented, it would be used and could have substantial effects in reducing domestic fuel consumption. Therefore, it is recommended that an energy labeling scheme be introduced.

  7. Like your labels?

    Science.gov (United States)

    Field, Michele

    2010-01-01

    The descriptive “conventions” used on food labels are always evolving. Today, however, the changes are so complicated (partly driven by legislation requiring disclosures about environmental impacts, health issues, and geographical provenance) that these labels more often baffle buyers than enlighten them. In a light-handed manner, the article points to how sometimes reading label language can be like deciphering runes—and how if we are familiar with the technical terms, we can find a literal meaning, but still not see the implications. The article could be ten times longer because food labels vary according to cultures—but all food-exporting cultures now take advantage of our short attention-span when faced with these texts. The question is whether less is more—and if so, in this contest for our attention, what “contestant” is voted off.

  8. The impact of the amount of intracellular SPIO on MR signal intensity during in vivo tracking of macrophage homing

    International Nuclear Information System (INIS)

    Kim, Dae Yoon; Lee, Jin Seong; Kang, Ju Hee; Sohn, Jin Young; Kim, Sang Tae; Woo, Chul Woong

    2008-01-01

    To determine whether the amount of intracellular superparamagnetic iron oxide (SPIO) in macrophages influences MR signal intensity during in vivo celluar tracking. Peritoneal macrophages harvested from thioglycolate-treated mice were labeled with SPIO using concentrations of 112, 56, and 28 μ gFe/ml, and different incubation times of 3h, 6h, 12h, 24h and 48h, respectively. The iron concentration was quantified with the use of absorption spectrophotometry. Each group of macrophages labeled with different concentrations of SPIO was intravenously injected into 18 mice, after inoculation with S. aureus to the thigh. The relative signal intensity (SI) of the abscess wall (SI of the abscess wall/SI of muscle) was measured on MR and was analyzed by the use of the Kruskal-Wallis test. A higher concentration of SPIO in the labeling solution and a longer incubation time resulted in a higher concentration of SPIO in the macrophages. The relative SI of the abscess wall (0.63 for 112 μ gFe/mL; 0.67 for 56 μ gFe/ml; 0.89 for 28 μ gFe/mL) significantly decreased with an increase of SPIO concentration (κ 2 = 10.53, ρ < 0.005). The amount of intracellular SPIO influences the MR signal intensity by the susceptibility effect and it is recommended to use sufficient iron-oxide label as long as it dose not affect cellular function and viability

  9. Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Bjørnar Sporsheim

    2015-12-01

    Full Text Available Volatile allyl isothiocyanate (AITC derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER, vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.

  10. Intracellular localisation of proteins to specific cellular areas by nanocapsule mediated delivery.

    Science.gov (United States)

    Wang, Huabin; Chen, Ligang; Sun, Xianchao; Fu, Ailing

    2017-09-01

    Nanocapsules are promising carriers with great potential for intracellular protein transport. Although many studies have intended to improve cell uptake efficacy, there is an increasing interest in understanding of subcellular distribution of cargoes inside cells, which is essential for purposeful delivery of biomolecules into specific sites within cells. Herein, we interrogate the intracellular localisation of exogenous proteins, including fluorescein isothiocyanate (FITC)-labelled bovine serum albumin (BSA) and green fluorescent protein (GFP), mediated by specially designed nanocapsules. The results show that the designed nanocapsules can deliver the two types of fluorescent proteins into different cellular destinations (cytosol, nucleus or the whole cell), depending on the composition of nanocapsules. Meanwhile, several impact factors that influence the distribution of proteins in cells have also been investigated, and the results suggest that the localisation of capsule-mediated proteins in cells is strongly affected by the surface properties of nanocapsules, the types of stabilisers and proteins, and environmental temperatures. The rational control of intracellular localised delivery of exogenous proteins as we demonstrated in this study might open new avenues to obtain desired magnitude of drug effects for modulating cell activity.

  11. Direct and sustained intracellular delivery of exogenous molecules using acoustic-transfection with high frequency ultrasound

    Science.gov (United States)

    Yoon, Sangpil; Kim, Min Gon; Chiu, Chi Tat; Hwang, Jae Youn; Kim, Hyung Ham; Wang, Yingxiao; Shung, K. Kirk

    2016-02-01

    Controlling cell functions for research and therapeutic purposes may open new strategies for the treatment of many diseases. An efficient and safe introduction of membrane impermeable molecules into target cells will provide versatile means to modulate cell fate. We introduce a new transfection technique that utilizes high frequency ultrasound without any contrast agents such as microbubbles, bringing a single-cell level targeting and size-dependent intracellular delivery of macromolecules. The transfection apparatus consists of an ultrasonic transducer with the center frequency of over 150 MHz and an epi-fluorescence microscope, entitled acoustic-transfection system. Acoustic pulses, emitted from an ultrasonic transducer, perturb the lipid bilayer of the cell membrane of a targeted single-cell to induce intracellular delivery of exogenous molecules. Simultaneous live cell imaging using HeLa cells to investigate the intracellular concentration of Ca2+ and propidium iodide (PI) and the delivery of 3 kDa dextran labeled with Alexa 488 were demonstrated. Cytosolic delivery of 3 kDa dextran induced via acoustic-transfection was manifested by diffused fluorescence throughout whole cells. Short-term (6 hr) cell viability test and long-term (40 hr) cell tracking confirmed that the proposed approach has low cell cytotoxicity.

  12. Labelling of electricity

    International Nuclear Information System (INIS)

    Dettli, R.; Markard, J.

    2001-01-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) presents a possible course of action to be taken to provide a means of declaring the sources of electrical power, as is foreseen in the draft of new Swiss electricity market legislation. The report presents the basic ideas behind the idea and defines the terms used such as labelling, certificates and declarations. Also, the legal situation in the European Union and in Switzerland is examined and a quantitative overview of electricity production and consumption is presented. Suggestions for a labelling scheme are made and some of the problems to be expected are looked at. The report also presents a series of examples of labelling schemes already implemented in other countries, such as Austria, Great Britain, Sweden and Germany. Tradable certificates and tracking systems are discussed as are initial quality labels like the Swiss 'Naturemade' label for green power. A concrete recommendation for the declaration and labelling of electricity in Switzerland is presented and various factors to be considered such as import/export, pumped storage, distribution losses, small-scale producers as well as the time-scales for introduction are discussed

  13. 78 FR 66826 - Prior Label Approval System: Generic Label Approval

    Science.gov (United States)

    2013-11-07

    ... raising of animals, such as ``no antibiotics administered'' or ``vegetarian fed''; (4) instructional or... Standards and Labeling Policy Book includes animal production claims; omega fatty acid guidance; allergen... inclusion of Country of Origin Labeling on all labels; the production and sale of labels by USDA; developing...

  14. Labeling of thymine with 99m technetium: a suggestion of a chemical model

    International Nuclear Information System (INIS)

    Gutfilen, Bianca; Silva, Claudia Ribeiro da; Bernardo Filho, Mario; Ribeiro, Barbara Luzia Almeida; Mattos, Maura Ferreira

    1996-01-01

    Successful targeting of diagnose but also to stage cancer. It has been shown that certain tumor cells are permeable to low level of exogenous adenosine-diphosphate and adenosine-triphosphate nucleotides, that are incorporated into intracellular pools. We present the labeling of a nucleotide precursor, a base, thymine technetium-99m ( 99m Tc). (author)

  15. Labeling of thymine with {sup 99m} technetium: a suggestion of a chemical model

    Energy Technology Data Exchange (ETDEWEB)

    Gutfilen, Bianca; Silva, Claudia Ribeiro da; Bernardo Filho, Mario [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Biologia. Dept. de Biofisica e Biometria; Ribeiro, Barbara Luzia Almeida [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Centro de Pesquisa Basica; Mattos, Maura Ferreira [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Quimica

    1996-03-01

    Successful targeting of diagnose but also to stage cancer. It has been shown that certain tumor cells are permeable to low level of exogenous adenosine-diphosphate and adenosine-triphosphate nucleotides, that are incorporated into intracellular pools. We present the labeling of a nucleotide precursor, a base, thymine technetium-99m ({sup 99m} Tc). (author)

  16. Two-dimensional polyacrylamide gel electrophoresis of intracellular proteins

    International Nuclear Information System (INIS)

    Ojima, N.; Sakamoto, T.; Yamashita, M.

    1996-01-01

    Since two-dimensional electrophoresis was established by O'Farrell for analysis of intracellular proteins of Escherichia coli, it has been applied to separation of proteins of animal cells and tissues, and especially to identification of stress proteins. Using this technique, proteins are separated by isoelectric focusing containing 8 m urea in the first dimension and by SDS-PAGE in the second dimension. The gels are stained with Coomassie Blue R-250 dye, followed by silver staining. In the case of radio-labeled proteins, the gels are dried and then autoradiographed. In order to identify a specific protein separated by two-dimensional electrophoresis, a technique determining the N-terminal amino acid sequence of the protein has been developed recently. After the proteins in the gel were electrotransferred to a polyvinylidene difluoride membrane, the membrane was stained for protein with Commassie Blue and a stained membrane fragment was applied to a protein sequencer. Our recent studies demonstrated that fish cells newly synthesized various proteins in response to heat shock, cold nd osmotic stresses. For example, when cellular proteins extracted from cold-treated rainbow trout cells were subjected to two-dimensional gel electrophoresis, the 70 kDa protein was found to be synthesized during the cold-treatment. N-Terminal sequence analysis showed that the cold-inducible protein was a homolog of mammalian valosin-containing protein and yeast cell division cycle gene product CDC48p. Furthermore, the sequence data were useful for preparing PCR primers and a rabbit antibody against a synthetic peptide to analyze a role for the protein in the function of trout cells and mechanisms for regulation

  17. Intracellular accumulation of potent amiloride analogues by human neutrophils

    International Nuclear Information System (INIS)

    Simchowitz, L.; Woltersdorf, O.W. Jr.; Cragoe, E.J. Jr.

    1987-01-01

    The mechanism of uptake of a series of amiloride derivatives by human neutrophils was investigated using [ 14 C]amiloride and the 14 C-labeled 5-(1-hexahydroazepinyl)-6-bromo analogue (BrMM) which is approximately 500-fold more potent than the parent compound at inhibiting Na+/H+ exchange. At an external concentration of 2 microM, the influx of BrMM at 37 degrees C was rapid, reaching a steady state by approximately 20 min. The rate of BrMM uptake (approximately 25 mumol/liter.min) was approximately 90-fold faster than for the same concentration of amiloride, a finding which correlates with differences in lipid partitioning of the two compounds. Uptake was unrelated to specific binding to Na+/H+ exchange transport sites: influx of either drug was nonsaturable whereas amiloride- and BrMM-mediated inhibition of Na+/H+ countertransport obeyed Michaelis-Menten kinetics with apparent Ki values of approximately 75 and approximately 0.2 microM. Entry occurred exclusively via the neutral (uncharged) forms (pK'a 8.40-8.55). Influx was markedly pH-dependent: it was enhanced by extracellular alkalinization and reduced by acidification. Influx was, however, insensitive to large changes in membrane voltage, thereby implying the protonated (charged) species to be impermeant. About 75% of the total intracellular pool of amiloride, but only approximately 25% of BrMM, is contained within the lysosomes, an expected consequence of the partitioning and subsequent trapping of a weak base within this strongly acidic subcellular compartment. With BrMM, there was a relative approximately 60-fold enrichment in the internal/external water concentration ratio of the drug; the value for amiloride was much less, approximately 4. This disparity is consistent with substantial binding of BrMM to internal constituents, presumably to proteins and/or nucleic acids

  18. Nanobodies: Chemical Functionalization Strategies and Intracellular Applications

    Science.gov (United States)

    Schumacher, Dominik; Helma, Jonas; Schneider, Anselm F. L.; Leonhardt, Heinrich

    2018-01-01

    Abstract Nanobodies can be seen as next‐generation tools for the recognition and modulation of antigens that are inaccessible to conventional antibodies. Due to their compact structure and high stability, nanobodies see frequent usage in basic research, and their chemical functionalization opens the way towards promising diagnostic and therapeutic applications. In this Review, central aspects of nanobody functionalization are presented, together with selected applications. While early conjugation strategies relied on the random modification of natural amino acids, more recent studies have focused on the site‐specific attachment of functional moieties. Such techniques include chemoenzymatic approaches, expressed protein ligation, and amber suppression in combination with bioorthogonal modification strategies. Recent applications range from sophisticated imaging and mass spectrometry to the delivery of nanobodies into living cells for the visualization and manipulation of intracellular antigens. PMID:28913971

  19. Drosophila VAMP7 regulates Wingless intracellular trafficking.

    Science.gov (United States)

    Gao, Han; He, Fang; Lin, Xinhua; Wu, Yihui

    2017-01-01

    Drosophila Wingless (Wg) is a morphogen that determines cell fate during development. Previous studies have shown that endocytic pathways regulate Wg trafficking and signaling. Here, we showed that loss of vamp7, a gene required for vesicle fusion, dramatically increased Wg levels and decreased Wg signaling. Interestingly, we found that levels of Dally-like (Dlp), a glypican that can interact with Wg to suppress Wg signaling at the dorsoventral boundary of the Drosophila wing, were also increased in vamp7 mutant cells. Moreover, Wg puncta in Rab4-dependent recycling endosomes were Dlp positive. We hypothesize that VAMP7 is required for Wg intracellular trafficking and the accumulation of Wg in Rab4-dependent recycling endosomes might affect Wg signaling.

  20. Intracellular pH in sperm physiology.

    Science.gov (United States)

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Nanobodies: Chemical Functionalization Strategies and Intracellular Applications.

    Science.gov (United States)

    Schumacher, Dominik; Helma, Jonas; Schneider, Anselm F L; Leonhardt, Heinrich; Hackenberger, Christian P R

    2018-02-23

    Nanobodies can be seen as next-generation tools for the recognition and modulation of antigens that are inaccessible to conventional antibodies. Due to their compact structure and high stability, nanobodies see frequent usage in basic research, and their chemical functionalization opens the way towards promising diagnostic and therapeutic applications. In this Review, central aspects of nanobody functionalization are presented, together with selected applications. While early conjugation strategies relied on the random modification of natural amino acids, more recent studies have focused on the site-specific attachment of functional moieties. Such techniques include chemoenzymatic approaches, expressed protein ligation, and amber suppression in combination with bioorthogonal modification strategies. Recent applications range from sophisticated imaging and mass spectrometry to the delivery of nanobodies into living cells for the visualization and manipulation of intracellular antigens. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  2. Intracellular Signalling by C-Peptide

    Directory of Open Access Journals (Sweden)

    Claire E. Hills

    2008-01-01

    Full Text Available C-peptide, a cleavage product of the proinsulin molecule, has long been regarded as biologically inert, serving merely as a surrogate marker for insulin release. Recent findings demonstrate both a physiological and protective role of C-peptide when administered to individuals with type I diabetes. Data indicate that C-peptide appears to bind in nanomolar concentrations to a cell surface receptor which is most likely to be G-protein coupled. Binding of C-peptide initiates multiple cellular effects, evoking a rise in intracellular calcium, increased PI-3-kinase activity, stimulation of the Na+/K+ ATPase, increased eNOS transcription, and activation of the MAPK signalling pathway. These cell signalling effects have been studied in multiple cell types from multiple tissues. Overall these observations raise the possibility that C-peptide may serve as a potential therapeutic agent for the treatment or prevention of long-term complications associated with diabetes.

  3. Intracellular sphingosine releases calcium from lysosomes.

    Science.gov (United States)

    Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

    2015-11-27

    To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC.

  4. Stereoselective synthesis of stable-isotope-labeled amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States); Lodwig, S.N. [Centralia College, WA (United States)

    1994-12-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the {alpha}-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids.

  5. Stereoselective synthesis of stable-isotope-labeled amino acids

    International Nuclear Information System (INIS)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III; Lodwig, S.N.

    1994-01-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the α-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids

  6. Magnetic cell sorting purification of differentiated embryonic stem cells stably expressing truncated human CD4 as surface marker.

    Science.gov (United States)

    David, Robert; Groebner, Michael; Franz, Wolfgang-Michael

    2005-04-01

    Embryonic stem (ES) cells offer great potential in regenerative medicine and tissue engineering. Clinical applications are still hampered by the lack of protocols for gentle, high-yield isolation of specific cell types for transplantation expressing no immunogenic markers. We describe labeling of stably transfected ES cells expressing a human CD4 molecule lacking its intracellular domain (DeltaCD4) under control of the phosphoglycerate kinase promoter for magnetic cell sorting (MACS). To track the labeled ES cells, we fused DeltaCD4 to an intracellular enhanced green fluorescent protein domain (DeltaCD4EGFP). We showed functionality of the membrane-bound fluorescent fusion protein and its suitability for MACS leading to purities greater than 97%. Likewise, expression of DeltaCD4 yielded up to 98.5% positive cells independently of their differentiation state. Purities were not limited by the initial percentage of DeltaCD4(+) cells, ranging from 0.6%-16%. The viability of MACS-selected cells was demonstrated by reaggregation and de novo formation of embryoid bodies developing all three germ layers. Thus, expression of DeltaCD4 in differentiated ES cells may enable rapid, high-yield purification of a desired cell type for tissue engineering and transplantation studies.

  7. [Limbic encephalitis with antibodies against intracellular antigens].

    Science.gov (United States)

    Morita, Akihiko; Kamei, Satoshi

    2010-04-01

    Limbic encephalitis is a paraneoplastic syndrome that is often associated with small cell lung cancer (SCLC), breast cancer, testicular tumors, teratoma, Hodgkin's lymphoma and thymoma. The common clinical manifestations of limbic encephalitis are subacute onset, cognitive dysfunction, seizures and psychiatric symptoms. Paraneoplastic neurological disorders are considered to occur because of cytotoxic T cell responses and antibodies against target neuronal proteins that are usually expressed by an underlying tumor. The main intracellular antigens related to limbic encephalitis are Hu, Ma2, and less frequently CV2/CRMP5 and amphiphysin. The anti-Hu antibody, which is involved in cerebellar degeneration and extensive or multifocal encephalomyelitis such as limbic encephalitis is closely associated with a history of smoking and SCLC. The anti-Ma2 antibody is associated with encephalitis of the limbic system, hypothalamus and brain-stem. For this reason, some patients with limbic encephalitis have sleep disorders (including REM sleep abnormalities), severe hypokinesis and gaze palsy in addition to limbic dysfunction. In men aged less than 50 years, anti-Ma2 antibody encephalitis is almost always associated with testicular germ-cell tumors that are occasionally difficult to detect. In older men and women, the most common tumors are non-SCLC and breast cancer. Limbic encephalitis associated with cell-surface antigens (e.g., voltage-gated potassium channels, NMDA receptors) is mediated by antibodies and often improves after a reduction in the antibody titer and after tumor resection. Patients with antibodies against intracellular antigens, except for those with anti-Ma2 antibodies and testicular tumors, are less responsive. Early diagnosis and treatment with immunotherapy, tumor resection or both are important for improving or stabilizing the condition of limbic encephalitis.

  8. European consumers and nutrition labelling

    DEFF Research Database (Denmark)

    Wills, Josephine M.; Grunert, Klaus G.; Celemín, Laura Fernández

    2009-01-01

    Nutrition labelling of food in Europe is not compulsory, unless a nutrition or health claim is made for the product. The European Commission is proposing mandatory nutrition labelling, even front of pack labelling with nutrition information. Yet, how widespread is nutrition labelling in the EU...

  9. Genetic algorithms for map labeling

    NARCIS (Netherlands)

    Dijk, Steven Ferdinand van

    2001-01-01

    Map labeling is the cartographic problem of placing the names of features (for example cities or rivers) on the map. A good labeling has no intersections between labels. Even basic versions of the problem are NP-hard. In addition, realistic map-labeling problems deal with many cartographic

  10. Single-cell intracellular nano-pH probes†

    OpenAIRE

    Özel, Rıfat Emrah; Lohith, Akshar; Mak, Wai Han; Pourmand, Nader

    2015-01-01

    Within a large clonal population, such as cancerous tumor entities, cells are not identical, and the differences between intracellular pH levels of individual cells may be important indicators of heterogeneity that could be relevant in clinical practice, especially in personalized medicine. Therefore, the detection of the intracellular pH at the single-cell level is of great importance to identify and study outlier cells. However, quantitative and real-time measurements of the intracellular p...

  11. Curcumin Mitigates the Intracellular Lipid Deposit Induced by Antipsychotics In Vitro.

    Directory of Open Access Journals (Sweden)

    Alberto Canfrán-Duque

    Full Text Available First- and second-generation antipsychotics (FGAs and SGAs, respectively, both inhibit cholesterol biosynthesis and impair the intracellular cholesterol trafficking, leading to lipid accumulation in the late endosome/lysosome compartment. In this study we examined if curcumin, a plant polyphenol that stimulates exosome release, can alleviate antipsychotic-induced intracellular lipid accumulation.HepG2 hepatocarcinoma cells were treated with antipsychotics or placebo and DiI-labelled LDL for 18 h and then exposed to curcumin for the last 2 h. Cells and media were collected separately and used for biochemical analyses, electron microscopy and immunocytochemistry. Exosomes were isolated from the incubation medium by ultracentrifugation.Curcumin treatment reduced the number of heterolysosomes and shifted their subcellular localization to the periphery, as revealed by electron microscopy, and stimulated the release of lysosomal β-hexosaminidase and exosome markers flotillin-2 and CD63 into the media. The presence of DiI in exosomes released by cells preloaded with DiI-LDL demonstrated the endolysosomal origin of the microvesicles. Furthermore, curcumin increased the secretion of cholesterol as well as LDL-derived DiI and [3H]-cholesterol, in association with a decrease of intracellular lipids. Thus, the disruption of lipid trafficking induced by FGAs or SGAs can be relieved by curcumin treatment. This polyphenol, however, did not mitigate the reduction of cholesterol esterification induced by antipsychotics.Curcumin stimulates exosome release to remove cholesterol (and presumably other lipids accumulated within the endolysosomal compartment, thereby normalizing intracellular lipid homeostasis. This action may help minimize the adverse metabolic effects of antipsychotic treatment, which should now be evaluated in clinical trials.

  12. Radioactive labelling of peptidic hormones

    International Nuclear Information System (INIS)

    Fromageot, P.; Pradelles, P.; Morgat, J.L.; Levine, H.

    1976-01-01

    The labelling of peptidic hormones requires stability, specificity and sensitivity of the label. Introduction of a radioactive atome is one way to satisfy these criteria. Several processes have been described to prepare radioactive TRF: synthesis of the peptide with labelled aminoacids or introduction of the label into the hormone. In that approach, tritium can be substituted in the imidazole ring, via precursors activating the proper carbon. Monoiodo TRF leads essentially to tritium labelling of the 5 positions whereas monoazo TRF allows the preparation of 3 H TRF labelled in the 2 positions. Di-substituted TRF leads to labelling into the 2 and 5 carbons. Labelled analogs of TRF can be prepared with labelled iodine; further developments of peptide labelling, will be presented. In particular, the homolytic scission of the C-iodine, bond by photochemical activation. The nascent carbon radical can be stabilized by a tritiated scavenger. This approach eliminates the use of heavy metal catalysts

  13. Radiopharmaceutical labeling research

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    The objective of this research is to develop methods of attaching radionuclides to monoclonal antibodies and antibody fragments for use in tumor imaging and internal radiation therapy. Monoclonal antibodies and their fragments are of interest because they enable the selective targeting of tumors. The labeled antibodies could be employed as carriers to transport radioisotopes to tumors, thus minimizing total-body radiation dose and radiation damage to normal tissue. Because the time required for labeled antibodies to find the tumor antigen and deliver the dose to the tumor is estimated to be about 1-3 days, radionuclides with a l- to 3-day half-life would be optimum for this purpose. Two of the radionuclides produced at LAMPF, 67 Cu and 77 Br, have the suitable half-life and nuclear-decay properties for use in tumor imaging or therapy with radiolabeled antibodies. These radionuclides and the efforts to prepare radiolabeled antibodies with them are described. We have used three different approaches to meet this objective of labeling antibodies: (1) labeling chelating agents with metal radionuclides, then conjugating the labeled chelating agents to antibodies; (2) conjugating activated chelating agents to antibodies, followed by metalation with metal radionuclides; and (3) radiobrominating small molecules that can be conjugated to antibodies

  14. Fluorine-18 labelled compounds

    International Nuclear Information System (INIS)

    Kleijn, J.P. de

    1978-01-01

    The work presented in this thesis deals with the problems involved in the adaption of reactor-produced fluorine-18 to the synthesis of 18 F-labelled organic fluorine compounds. Several 18 F-labelling reagents were prepared and successfully applied. The limitations to the synthetic possibilities of reactor-produced fluoride- 18 become manifest in the last part of the thesis. An application to the synthesis of labelled aliphatic fluoro amino acids has appeared to be unsuccessful as yet, although some other synthetic approaches can be indicated. Seven journal articles (for which see the availability note) are used to compose the four chapters and three appendices. The connecting text gives a survey of known 18 F-compounds and methods for preparing such compounds. (Auth.)

  15. Synthesis of labeled compounds

    International Nuclear Information System (INIS)

    Whaley, T.W.

    1977-01-01

    Intermediate compounds labeled with 13 C included methane, sodium cyanide, methanol, ethanol, and acetonitrile. A new method for synthesizing 15 N-labeled 4-ethylsulfonyl-1-naphthalene-sulfonamide was developed. Studies were conducted on pathways to oleic-1- 13 C acid and a second pathway investigated was based on carbonation of 8-heptadecynylmagnesium bromide with CO 2 to prepare sterolic acid. Biosynthetic preparations included glucose- 13 C from starch isolated from tobacco leaves following photosynthetic incubation with 13 CO 2 and galactose- 13 C from galactosylglycerol- 13 C from kelp. Research on growth of organisms emphasized photosynthetic growth of algae in which all cellular carbon is labeled. Preliminary experiments were performed to optimize the growth of Escherichia coli on sodium acetate- 13 C

  16. Labelling of leucocytes with colloidal technetium-99m-SnF{sub 2}: an investigation of the labelling process by autoradiography

    Energy Technology Data Exchange (ETDEWEB)

    Puncher, M.R.B. [Biological Lab., Canterbury Univ. (United Kingdom); Blower, P.J. [Nuclear Medicine Dept., Kent and Canterbury Hospital, Canterbury (United Kingdom)

    1995-02-01

    Autoradiography of smears and frozen sections of labelled cell suspensions was used to study the distribution of radioactivity in and among blood cells labelled in either whole blood or leucocyte-rich plasma (LRP) with technetium-99m-SnF{sub 2} colloid. The tracer proved selective for neutrophils: the labelling probability (relative to that for erythrocytes) for each cell type in LRP (mean of five samples) was: neutrophils, 9.4; lymphocytes, 3.7; monocytes, 3.0; eosinophils 1.4; erythrocytes, 1.0. When labelling was carried out in whole blood (five samples), 74.5%{+-}8.3% of the cell-bound radioactivity was bound to erythrocytes, 13.6%{+-}6.5% to neutrophils, and 11.9%{+-}2.1% to lymphocytes, whereas in LRP (in which the leucocytes were only slightly outnumbered by erythrocytes), 76.5%{+-}14.9% of radioactivity was neutrophil bound. Labelled cells in smear autoradiographs exhibited two distinct silver grain patterns, ``diffuse``, consistent with an intracellular radioactive particle (in neutrophils), and ``focal``, consistent with a cell surface-adhering particle in direct contact with the emulsion (in other leucocyte types and erythrocytes). The phagocytic inhibitor cytochalasin B neither reduced the proportion of labelled neutrophils nor altered the labelling pattern. Neutrophils were able to scavenge radioactivity from the surface of erythrocytes. It is concluded that neutrophils bind {sup 99m}Tc-SnF{sub 2} intracellularly by phagocytosis, with high affinity; other cells become labelled at the cell surface reversibly and with lower affinity. This selectivity is high enough to permit predominantly leucocyte labelling in LRP but not in whole blood. (orig.)

  17. Inter- and intracellular relationship of substance P-containing neurons with serotonin and GABA in the dorsal raphe nucleus: combination of autoradiographic and immunocytochemical techniques

    International Nuclear Information System (INIS)

    Magoul, R.; Onteniente, B.; Oblin, A.; Calas, A.

    1986-01-01

    Double-labeling experiments were performed at the electron microscopic level in the dorsal raphe nucleus of rat, in order to study the inter- and intracellular relationship of substance P with gamma-aminobutyric acid (GABA) and serotonin. Autoradiography for either [ 3 H]serotonin or [ 3 H]GABA was coupled, on the same tissue section, with peroxidase-antiperoxidase immunocytochemistry for substance P in colchicine-treated animals. Intercellular relationships were represented by synaptic contacts made by [ 3 H]serotonin-labeled terminals on substance P-containing somata and dendrites, and by substance P-containing terminals on [ 3 H]GABA-labeled cells. Intracellular relationships were suggested by the occurrence of the peptide within [ 3 H]serotonin-containing and [ 3 H]GABA-containing cell bodies and fibers. Doubly labeled varicosities of the two kinds were also observed in the supraependymal plexus adjacent to the dorsal raphe nucleus. The results demonstrated that, in addition to reciprocal synaptic interactions made by substance P with serotonin and GABA, the dorsal raphe nucleus is the site of intracellular relationships between the peptide and either the amine or the amino acid

  18. Environmental Labels and Declarations

    DEFF Research Database (Denmark)

    Frydendal, Jeppe; Hansen, Lisbeth; Bonou, Alexandra

    2018-01-01

    Based on the terminology and structure developed by the International Organization for Standardization, a description is given on the types of ecolabels that build on life cycle assessments. Focus is on type I labels that point out products and services with an overall environmental preferability...... of labelling, the use of ecolabels in marketing, and the way ecolabels help build a market for “greener products”. Type III labels—or Environmental Product Declarations—are also briefly described with indicative examples from the building sector, a declaration for office furniture, and an introduction is given...... to the European Commission’s programme for product—and organisational environmental footprints ....

  19. Semantic Role Labeling

    CERN Document Server

    Palmer, Martha; Xue, Nianwen

    2011-01-01

    This book is aimed at providing an overview of several aspects of semantic role labeling. Chapter 1 begins with linguistic background on the definition of semantic roles and the controversies surrounding them. Chapter 2 describes how the theories have led to structured lexicons such as FrameNet, VerbNet and the PropBank Frame Files that in turn provide the basis for large scale semantic annotation of corpora. This data has facilitated the development of automatic semantic role labeling systems based on supervised machine learning techniques. Chapter 3 presents the general principles of applyin

  20. Synthesis of specifically 15N- and 13C-labeled antitumor (2-Haloethyl)nitrosoureas. The study of their conformations in solution by nitrogen-15 and carbon-13 nuclear magnetic resonance and evidence for stereoelectronic control in their aqueous decomposition

    International Nuclear Information System (INIS)

    Lown, J.W.; Chauhan, S.M.S.

    1981-01-01

    The synthesis of certain specifically 15 N, 13 C, and 2 H isotope labeled 1-(2-chloroethyl)-3-alkyl-1-nitrosoureas (CENUs) is described. Spectroscopic examination of CENUs and their isotope-labeled counterparts by 1 H, 15 N, and 13 C NMR and infrared spectra indicates that they adopt preferred conformations in nonpolar aprotic solvents in which the NO group is aligned toward the 2-chloroethyl group. The result is in accord with the conformation of MeCCNU in the crystalline state derived from X-ray diffraction. The chemical shifts and coupling constants in the CENUs change with both solvent polarity and basicity. In aqueous phosphate buffer there is evidence for the formation of a tetrahedral intermediate, the conformation of which alters according to the reaction conditions and ultimately controls the formation of the aqueous decomposition products of CENUs. This is revealed most clearly by 13 C NMR of carbonyl- 13 C- and nitroso- 15 N-labeled BCNU and CCNU where two distinct 15 N-coupled 13 C doublets with different chemical shifts are observed. The rate of conformational change is comparable with the rate of decomposition of CENUs (via the second conformer) and may therefore represent the critical initial step of the latter process in vivo. The intermediacy of the postulated tetrahedral intermediates for CENUs is supported by observed 18 O exchange into the carbonyl group in 18 O-enriched water. Consideration of the conformations of the intermediates and of the alignment of the heteroatom lone pairs provides a satisfactory interpretation of the reactions of CENUs in aqueous solution as well as their pH dependence in terms of strict steroelectronic control and accounts for the formation of the observed products

  1. Advances in stable isotope assisted labeling strategies with information science.

    Science.gov (United States)

    Kigawa, Takanori

    2017-08-15

    Stable-isotope (SI) labeling of proteins is an essential technique to investigate their structures, interactions or dynamics by nuclear magnetic resonance (NMR) spectroscopy. The assignment of the main-chain signals, which is the fundamental first step in these analyses, is usually achieved by a sequential assignment method based on triple resonance experiments. Independently of the triple resonance experiment-based sequential assignment, amino acid-selective SI labeling is beneficial for discriminating the amino acid type of each signal; therefore, it is especially useful for the signal assignment of difficult targets. Various combinatorial selective labeling schemes have been developed as more sophisticated labeling strategies. In these strategies, amino acids are represented by combinations of SI labeled samples, rather than simply assigning one amino acid to one SI labeled sample as in the case of conventional amino acid-selective labeling. These strategies have proven to be useful for NMR analyses of difficult proteins, such as those in large complex systems, in living cells, attached or integrated into membranes, or with poor solubility. In this review, recent advances in stable isotope assisted labeling strategies will be discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Endothelial remodelling and intracellular calcium machinery.

    Science.gov (United States)

    Moccia, F; Tanzi, F; Munaron, L

    2014-05-01

    Rather being an inert barrier between vessel lumen and surrounding tissues, vascular endothelium plays a key role in the maintenance of cardiovascular homeostasis. The de-endothelialization of blood vessels is regarded as the early event that results in the onset of severe vascular disorders, including atherosclerosis, acute myocardial infarction, brain stroke, and aortic aneurysm. Restoration of the endothelial lining may be accomplished by the activation of neighbouring endothelial cells (ECs) freed by contact inhibition and by circulating endothelial progenitor cells (EPCs). Intracellular Ca(2+) signalling is essential to promote wound healing: however, the molecular underpinnings of the Ca(2+) response to injury are yet to be fully elucidated. Similarly, the components of the Ca(2+) toolkit that drive EPC incorporation into denuded vessels are far from being fully elucidated. The present review will survey the current knowledge on the role of Ca(2+) signalling in endothelial repair and in EPC activation. We propose that endothelial regeneration might be boosted by intraluminal release of specific Ca(2+) channel agonists or by gene transfer strategies aiming to enhance the expression of the most suitable Ca(2+) channels at the wound site. In this view, connexin (Cx) channels/hemichannels and store-operated Ca(2+) entry (SOCE) stand amid the most proper routes to therapeutically induce the regrowth of denuded vessels. Cx stimulation might trigger the proliferative and migratory behaviour of ECs facing the lesion site, whereas activation of SOCE is likely to favour EPC homing to the wounded vessel.

  3. Intracellular events regulating cross-presentation

    Directory of Open Access Journals (Sweden)

    Peter eCresswell

    2012-06-01

    Full Text Available Cross-presentation plays a fundamental role in the induction of CD8-T cell immunity. However, although more than three decades have passed since its discovery, surprisingly little is known about the exact mechanisms involved. Here we give an overview of the components involved at different stages of this process. First, antigens must be internalized into the cross-presenting cell. The involvement of different receptors, method of antigen uptake, and nature of the antigen can influence intracellular trafficking and access to the cross-presentation pathway. Once antigens access the endocytic system, different requirements for endosomal/phagosomal processing arise, such as proteolysis and reduction of disulfide bonds. The majority of cross-presented peptides are generated by proteasomal degradation. Therefore, antigens must cross a membrane barrier in a manner analogous to the fate of misfolded proteins in the endoplasmic reticulum (ER that are retrotranslocated into the cytosol for degradation. Indeed, some components of the ER-associated degradation (ERAD machinery have been implicated in cross-presentation. Further complicating the matter, endosomal and phagosomal compartments have been suggested as alternative sites to the ER for loading of peptides on MHC class I molecules. Finally, the antigen presenting cells involved, particularly dendritic cell subsets and their state of maturation, influence the efficiency of cross-presentation.

  4. Intracellular recording from a spider vibration receptor.

    Science.gov (United States)

    Gingl, Ewald; Burger, Anna-M; Barth, Friedrich G

    2006-05-01

    The present study introduces a new preparation of a spider vibration receptor that allows intracellular recording of responses to natural mechanical or electrical stimulation of the associated mechanoreceptor cells. The spider vibration receptor is a lyriform slit sense organ made up of 21 cuticular slits located on the distal end of the metatarsus of each walking leg. The organ is stimulated when the tarsus receives substrate vibrations, which it transmits to the organ's cuticular structures, reducing the displacement to about one tenth due to geometrical reasons. Current clamp recording was used to record action potentials generated by electrical or mechanical stimuli. Square pulse stimulation identified two groups of sensory cells, the first being single-spike cells which generated only one or two action potentials and the second being multi-spike cells which produced bursts of action potentials. When the more natural mechanical sinusoidal stimulation was applied, differences in adaptation rate between the two cell types remained. In agreement with prior extracellular recordings, both cell types showed a decrease in the threshold tarsus deflection with increasing stimulus frequency. Off-responses to mechanical stimuli have also been seen in the metatarsal organ for the first time.

  5. On the Computing Potential of Intracellular Vesicles.

    Science.gov (United States)

    Mayne, Richard; Adamatzky, Andrew

    2015-01-01

    Collision-based computing (CBC) is a form of unconventional computing in which travelling localisations represent data and conditional routing of signals determines the output state; collisions between localisations represent logical operations. We investigated patterns of Ca2+-containing vesicle distribution within a live organism, slime mould Physarum polycephalum, with confocal microscopy and observed them colliding regularly. Vesicles travel down cytoskeletal 'circuitry' and their collisions may result in reflection, fusion or annihilation. We demonstrate through experimental observations that naturally-occurring vesicle dynamics may be characterised as a computationally-universal set of Boolean logical operations and present a 'vesicle modification' of the archetypal CBC 'billiard ball model' of computation. We proceed to discuss the viability of intracellular vesicles as an unconventional computing substrate in which we delineate practical considerations for reliable vesicle 'programming' in both in vivo and in vitro vesicle computing architectures and present optimised designs for both single logical gates and combinatorial logic circuits based on cytoskeletal network conformations. The results presented here demonstrate the first characterisation of intracelluar phenomena as collision-based computing and hence the viability of biological substrates for computing.

  6. Modeling HIV-1 intracellular replication: two simulation approaches

    NARCIS (Netherlands)

    Zarrabi, N.; Mancini, E.; Tay, J.; Shahand, S.; Sloot, P.M.A.

    2010-01-01

    Many mathematical and computational models have been developed to investigate the complexity of HIV dynamics, immune response and drug therapy. However, there are not many models which consider the dynamics of virus intracellular replication at a single level. We propose a model of HIV intracellular

  7. Intracellular Drug Bioavailability: Effect of Neutral Lipids and Phospholipids.

    Science.gov (United States)

    Treyer, Andrea; Mateus, André; Wiśniewski, Jacek R; Boriss, Hinnerk; Matsson, Pär; Artursson, Per

    2018-06-04

    Intracellular unbound drug concentrations are the pharmacologically relevant concentrations for targets inside cells. Intracellular drug concentrations are determined by multiple processes, including the extent of drug binding to intracellular structures. The aim of this study was to evaluate the effect of neutral lipid (NL) and phospholipid (PL) levels on intracellular drug disposition. The NL and/or PL content of 3T3-L1 cells were enhanced, resulting in phenotypes (in terms of morphology and proteome) reminiscent of adipocytes (high NL and PL) or mild phospholipidosis (only high PL). Intracellular bioavailability ( F ic ) was then determined for 23 drugs in these cellular models and in untreated wild-type cells. A higher PL content led to higher intracellular drug binding and a lower F ic . The induction of NL did not further increase drug binding but led to altered F ic due to increased lysosomal pH. Further, there was a good correlation between binding to beads coated with pure PL and intracellular drug binding. In conclusion, our results suggest that PL content is a major determinant of drug binding in cells and that PL beads may constitute a simple alternative to estimating this parameter. Further, the presence of massive amounts of intracellular NLs did not influence drug binding significantly.

  8. Indium-111 oxine labelling of white blood cells

    International Nuclear Information System (INIS)

    Lavender, J.P.; Silvester, D.J.; Goldman, J.; Hammersmith Hospital, London

    1978-01-01

    Following work done by Professor John McAfee and Mathew Thakur at the MRS Cyclotron Unit a method is available for labelling cells with indium-111 which results in a stable intracellular marker. The method uses indium-111-8 hydroxyquinoline (111In oxine) which is a lipoid soluble complex which goes across the cell membrane and results in the deposition of indium into various subcellular structures. It has been applied to various preparations of white cells, platelets and also malignant cells. Autologous granulocytes have been used to identify inflammatory lesions in 35 patients. By similar means autologous lymphocytes can also be labelled and reinfused. Lymphocytes have been shown in animals to circulate from the blood via the lymphatic system and then returning to the blood once more. The same phenomenon can be seen in man using indium labelled lymphocytes. Lymph nodes become visible at between 12 and 18 hours and recirculation of labelled cells can be shown on the blood activity curves. Certain problems arise concerning cell behaviour after labelling which appear due to irradiation of cells rather than chemical toxicity. (author)

  9. Accelerated stem cell labeling with ferucarbotran and protamine

    Energy Technology Data Exchange (ETDEWEB)

    Golovko, Daniel M.; Henning, Tobias; Bauer, Jan S. [Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA (United States); Settles, Marcus; Rummeny, Ernst J. [Technical University Munich, Department of Radiology, Munich (Germany); Frenzel, Thomas [Bayer Schering Pharma AG, Berlin (Germany); Mayerhofer, Artur [Ludwig-Maximilians-Universitaet, Institute of Cell Biology, Munich (Germany); Daldrup-Link, Heike E. [Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA (United States); UCSF Medical Center, Contrast Agent Research Group, Department of Radiology, San Francisco, CA (United States)

    2010-03-15

    To develop and characterize a clinically applicable, fast and efficient method for stem cell labeling with ferucarbotran and protamine for depiction with clinical MRI. The hydrodynamic diameter, zeta potential and relaxivities of ferucarbotran and varying concentrations of protamine were measured. Once the optimized ratio was found, human mesenchymal stem cells (MSCs) were labeled at varying incubation times (1-24 h). Viability was assessed via Trypan blue exclusion testing. 150,000 labeled cells in Ficoll solution were imaged with T1-, T2- and T2*-weighted sequences at 3 T, and relaxation rates were calculated. Varying the concentrations of protamine allows for easy modification of the physicochemical properties. Simple incubation with ferucarbotran alone resulted in efficient labeling after 24 h of incubation while assisted labeling with protamine resulted in similar results after only 1 h. Cell viability remained unaffected. R2 and R2* relaxation rates were drastically increased. Electron microscopy confirmed intracellular iron oxide uptake in lysosomes. Relaxation times correlated with results from ICP-AES. Our results show internalization of ferucarbotran can be accelerated in MSCs with protamine, an approved heparin antagonist and potentially clinically applicable uptake-enhancing agent. (orig.)

  10. Competing Environmental Labels

    NARCIS (Netherlands)

    Fischer, Carolyn; Lyon, Thomas P.

    2014-01-01

    We study markets in which consumers prefer green products but cannot determine the environmental quality of any given firm's product on their own. A nongovernmental organization (NGO) can establish a voluntary standard and label products that comply with it. Alternatively, industry can create its

  11. The Language of Labels

    Science.gov (United States)

    Markham, Darcy

    2005-01-01

    The author describes how the language of labels and her own cultural biases affect how she approaches teaching her students with disabilities. The author examines how the mythopoetic narratives of our past force us to examine the underlying assumptions of our culture that are expressed within our language and how understanding our own linguistic…

  12. Labeling of Cosmetic Products

    Directory of Open Access Journals (Sweden)

    Nicola Lionetti

    2018-03-01

    Full Text Available The labeling of cosmetic products provides a set of obligations, as reported in the Regulation 1223/2009, which came into force in Europe in July 2013. The indications reported on the label are intended to enable the clear identification of the functionality and proper use of cosmetics, ensure the protection of the consumer from the commercial aspects and, above all, from the safety point of view. Moreover, it should allow quick tracing of the product details and all info of toxicological relevance. However, the misuse of this tool often leads, on one side, to confusion among cosmetics, pharmaceuticals, medical devices, and biocides. On the other side, it gives rise to fanciful interpretations by a huge number of web users, who pretend to be able to judge the quality of a cosmetic product just by reading the ingredients list. This article points out the concrete purpose of cosmetic labels, in order to shed light on the use of certain categories of ‘controversial’ ingredients and on the real quality concepts of cosmetic products. Indeed, when properly interpreted, cosmetic labels represent a good tool for the professional investigation of adverse reactions to cosmetics.

  13. Induction of a stringent metabolic response in intracellular stages of Leishmania mexicana leads to increased dependence on mitochondrial metabolism.

    Directory of Open Access Journals (Sweden)

    Eleanor C Saunders

    2014-01-01

    Full Text Available Leishmania parasites alternate between extracellular promastigote stages in the insect vector and an obligate intracellular amastigote stage that proliferates within the phagolysosomal compartment of macrophages in the mammalian host. Most enzymes involved in Leishmania central carbon metabolism are constitutively expressed and stage-specific changes in energy metabolism remain poorly defined. Using (13C-stable isotope resolved metabolomics and (2H2O labelling, we show that amastigote differentiation is associated with reduction in growth rate and induction of a distinct stringent metabolic state. This state is characterized by a global decrease in the uptake and utilization of glucose and amino acids, a reduced secretion of organic acids and increased fatty acid β-oxidation. Isotopomer analysis showed that catabolism of hexose and fatty acids provide C4 dicarboxylic acids (succinate/malate and acetyl-CoA for the synthesis of glutamate via a compartmentalized mitochondrial tricarboxylic acid (TCA cycle. In vitro cultivated and intracellular amastigotes are acutely sensitive to inhibitors of mitochondrial aconitase and glutamine synthetase, indicating that these anabolic pathways are essential for intracellular growth and virulence. Lesion-derived amastigotes exhibit a similar metabolism to in vitro differentiated amastigotes, indicating that this stringent response is coupled to differentiation signals rather than exogenous nutrient levels. Induction of a stringent metabolic response may facilitate amastigote survival in a nutrient-poor intracellular niche and underlie the increased dependence of this stage on hexose and mitochondrial metabolism.

  14. Analysis of Intracellular Metabolites from Microorganisms: Quenching and Extraction Protocols.

    Science.gov (United States)

    Pinu, Farhana R; Villas-Boas, Silas G; Aggio, Raphael

    2017-10-23

    Sample preparation is one of the most important steps in metabolome analysis. The challenges of determining microbial metabolome have been well discussed within the research community and many improvements have already been achieved in last decade. The analysis of intracellular metabolites is particularly challenging. Environmental perturbations may considerably affect microbial metabolism, which results in intracellular metabolites being rapidly degraded or metabolized by enzymatic reactions. Therefore, quenching or the complete stop of cell metabolism is a pre-requisite for accurate intracellular metabolite analysis. After quenching, metabolites need to be extracted from the intracellular compartment. The choice of the most suitable metabolite extraction method/s is another crucial step. The literature indicates that specific classes of metabolites are better extracted by different extraction protocols. In this review, we discuss the technical aspects and advancements of quenching and extraction of intracellular metabolite analysis from microbial cells.

  15. Analysis of Intracellular Metabolites from Microorganisms: Quenching and Extraction Protocols

    Directory of Open Access Journals (Sweden)

    Farhana R. Pinu

    2017-10-01

    Full Text Available Sample preparation is one of the most important steps in metabolome analysis. The challenges of determining microbial metabolome have been well discussed within the research community and many improvements have already been achieved in last decade. The analysis of intracellular metabolites is particularly challenging. Environmental perturbations may considerably affect microbial metabolism, which results in intracellular metabolites being rapidly degraded or metabolized by enzymatic reactions. Therefore, quenching or the complete stop of cell metabolism is a pre-requisite for accurate intracellular metabolite analysis. After quenching, metabolites need to be extracted from the intracellular compartment. The choice of the most suitable metabolite extraction method/s is another crucial step. The literature indicates that specific classes of metabolites are better extracted by different extraction protocols. In this review, we discuss the technical aspects and advancements of quenching and extraction of intracellular metabolite analysis from microbial cells.

  16. Label Review Training: Module 1: Label Basics, Page 7

    Science.gov (United States)

    Page 7, Label Training, Pesticide labels translate results of our extensive evaluations of pesticide products into conditions, directions and precautions that define parameters for use of a pesticide with the goal of ensuring protection of human he

  17. Imaging and controlling intracellular reactions: Lysosome transport as a function of diameter and the intracellular synthesis of conducting polymers

    Science.gov (United States)

    Payne, Christine

    2014-03-01

    Eukaryotic cells are the ultimate complex environment with intracellular chemical reactions regulated by the local cellular environment. For example, reactants are sequestered into specific organelles to control local concentration and pH, motor proteins transport reactants within the cell, and intracellular vesicles undergo fusion to bring reactants together. Current research in the Payne Lab in the School of Chemistry and Biochemistry at Georgia Tech is aimed at understanding and utilizing this complex environment to control intracellular chemical reactions. This will be illustrated using two examples, intracellular transport as a function of organelle diameter and the intracellular synthesis of conducting polymers. Using single particle tracking fluorescence microscopy, we measured the intracellular transport of lysosomes, membrane-bound organelles, as a function of diameter as they underwent transport in living cells. Both ATP-dependent active transport and diffusion were examined. As expected, diffusion scales with the diameter of the lysosome. However, active transport is unaffected suggesting that motor proteins are insensitive to cytosolic drag. In a second example, we utilize intracellular complexity, specifically the distinct micro-environments of different organelles, to carry out chemical reactions. We show that catalase, found in the peroxisomes of cells, can be used to catalyze the polymerization of the conducting polymer PEDOT:PSS. More importantly, we have found that a range of iron-containing biomolecules are suitable catalysts with different iron-containing biomolecules leading to different polymer properties. These experiments illustrate the advantage of intracellular complexity for the synthesis of novel materials.

  18. Intracellular Localization of Arabidopsis Sulfurtransferases1

    Science.gov (United States)

    Bauer, Michael; Dietrich, Christof; Nowak, Katharina; Sierralta, Walter D.; Papenbrock, Jutta

    2004-01-01

    Sulfurtransferases (Str) comprise a group of enzymes widely distributed in archaea, eubacteria, and eukaryota which catalyze the transfer of a sulfur atom from suitable sulfur donors to nucleophilic sulfur acceptors. In all organisms analyzed to date, small gene families encoding Str proteins have been identified. The gene products were localized to different compartments of the cells. Our interest concerns the localization of Str proteins encoded in the nuclear genome of Arabidopsis. Computer-based prediction methods revealed localization in different compartments of the cell for six putative AtStrs. Several methods were used to determine the localization of the AtStr proteins experimentally. For AtStr1, a mitochondrial localization was demonstrated by immunodetection in the proteome of isolated mitochondria resolved by one- and two-dimensional gel electrophoresis and subsequent blotting. The respective mature AtStr1 protein was identified by mass spectrometry sequencing. The same result was obtained by transient expression of fusion constructs with the green fluorescent protein in Arabidopsis protoplasts, whereas AtStr2 was exclusively localized to the cytoplasm by this method. Three members of the single-domain AtStr were localized in the chloroplasts as demonstrated by transient expression of green fluorescent protein fusions in protoplasts and stomata, whereas the single-domain AtStr18 was shown to be cytoplasmic. The remarkable subcellular distribution of AtStr15 was additionally analyzed by transmission electron immunomicroscopy using a monospecific antibody against green fluorescent protein, indicating an attachment to the thylakoid membrane. The knowledge of the intracellular localization of the members of this multiprotein family will help elucidate their specific functions in the organism. PMID:15181206

  19. Intracellular signaling by diffusion: can waves of hydrogen peroxide transmit intracellular information in plant cells?

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    of the physical and biochemical conditions in plant cells. As model system, we use a H(2)O(2) signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits......Amplitude- and frequency-modulated waves of Ca(2+) ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view...

  20. Spin labels. Applications in biology

    International Nuclear Information System (INIS)

    Frangopol, T.P.; Frangopol, M.; Ionescu, S.M.; Pop, I.V.; Benga, G.

    1980-11-01

    The main applications of spin labels in the study of biomembranes, enzymes, nucleic acids, in pharmacology, spin immunoassay are reviewed along with the fundamentals of the spin label method. 137 references. (author)

  1. Cell growth, intracellular calcium concentration and metabolic cooperation measured in cells exposed to 50 Hz electromagnetic fields

    International Nuclear Information System (INIS)

    Skauli, K.S.

    1996-08-01

    Colony-forming efficiency, DNA/protein and DNA/cell were measured in cells exposed to magnetic fields of 0.2 and 1 mT at a frequency of 50 Hz. Intracellular calcium concentrations were measured in cells exposed to 0.3 and 1 mT at 50 Hz. Metabolic cooperation was measured in cells exposed to 1 mT at 50 Hz. No significant effects of the fields were observed. 20 refs., 10 figs

  2. Fluorescently labeled bionanotransporters of nucleic acid based on carbon nanotubes

    International Nuclear Information System (INIS)

    Novopashina, D.S.; Apartsin, E.K.; Venyaminova, A.G.

    2012-01-01

    We propose an approach to the design of a new type of hybrids of oligonucleotides with fluorescein-functionalized single-walled carbon nanotubes. The approach is based on stacking interactions of functionalized nanotubes with pyrene residues in conjugates of oligonucleotides. The amino- and fluorescein-modified single walled carbon nanotubes are obtained, and their physico-chemical properties are investigated. The effect of the functionalization type of carbon nanotubes on the efficacy of the sorption of pyrene conjugates of oligonucleotides was examined. The proposed noncovalent hybrids of fluorescein-labeled carbon nanotubes with oligonucleotides may be used for the intracellular transport of functional nucleic acids.

  3. Modeling the effects of labeling

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Fjord, Thomas Ahle; Poulsen, Carsten Stig

    A new approach to evaluate the consequences of labeling is presented and applied to test the potential effect of a label on fresh fish. Labeling effects on quality perceptions and overall quality are studied. The empirical study is based on an experimental design and nearly 500 respondents...

  4. Isotopically labelled benzodiazepines

    International Nuclear Information System (INIS)

    Liebman, A.A.

    1987-01-01

    This paper reports on the benzodiazepines which are a class of therapeutic agents. Improvements in the analytical methodology in the areas of biochemistry and pharmacology were significant, particularly in the application of chromatographic and spectroscopic techniques. In addition, the discovery and subsequent development of tritium and carbon-14 as an analytical tool in the biological sciences were essentially post-world war II phenomena. Thus, as these new chemical entities were found to be biologically active, they could be prepared in labeled form for metabolic study, biological half-life determination (pharmacokinetics), tissue distribution study, etc. This use of tracer methodology has been liberally applied to the benzodiazepines and also more recently to the study of receptor-ligand interactions, in which tritium, carbon-11 or fluorine-18 isotopes have been used. The history of benzodiazepines as medicinal agents is indeed an interesting one; an integral part of that history is their use in just about every conceivable labeled form

  5. Stable isotope labeling strategy based on coding theory

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori, E-mail: kigawa@riken.jp [RIKEN Quantitative Biology Center (QBiC), Laboratory for Biomolecular Structure and Dynamics (Japan)

    2015-10-15

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells.

  6. Stable isotope labeling strategy based on coding theory

    International Nuclear Information System (INIS)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori

    2015-01-01

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells

  7. Zinc fixation preserves flow cytometry scatter and fluorescence parameters and allows simultaneous analysis of DNA content and synthesis, and intracellular and surface epitopes

    DEFF Research Database (Denmark)

    Jensen, Uffe Birk; Owens, David; Pedersen, Søren

    2010-01-01

    Zinc salt-based fixation (ZBF) has proved advantageous in histochemical analyses conducted on intact tissues but has not been exploited in flow cytometry procedures that focus on quantitative analysis of individual cells. Here, we show that ZBF performs equally well to paraformaldehyde in the pre......Zinc salt-based fixation (ZBF) has proved advantageous in histochemical analyses conducted on intact tissues but has not been exploited in flow cytometry procedures that focus on quantitative analysis of individual cells. Here, we show that ZBF performs equally well to paraformaldehyde...... allowing subsequent quantitative PCR analysis or labeling for incorporation of the thymidine analog EdU following surface and intracellular epitope staining. Finally, ZBF treatment allows for long-term storage of labeled cells with little change in these parameters. Thus, we present a protocol for zinc...... salt fixation of cells that allows for the simultaneous analysis of DNA and intracellular and cell surface proteins by flow cytometry....

  8. Extracellular and intracellular steroid binding proteins

    International Nuclear Information System (INIS)

    Wagner, R.K.

    1978-01-01

    Steroid hormone binding proteins can be measured, after the removal of endogenous steroids, as specific complexes with radio-labelled hormones. In this study all the requirements for a quantitative determination of steroid hormone binding proteins are defined. For different methods, agargel electrophoresis, density gradient centrifugation, equilibrium dialysis and polyacrylamide electrophoresis have been evaluated. Agar electrophoresis at low temperature was found to be the simplest and most useful procedure. With this method the dissociation rates of high affinity complexes can be assessed and absolute binding protein concentrations can be determined. The dissociation rates of the oestradiol-oestrogen receptor complex and the R-5020-progestin receptor complex are low (1-2% per h run time.) In contrast, that of complexes between androgen receptor and dihydrotestosterone (17β-hydroxy-5α-androstan-3-one (DHT), progestin receptor and progesterone, corticosteroid binding globulin (CBG) and cortisol or progesterone and sex hormone binding globulin (SHBG) and DHT were hign (16-27% per h run time). Target tissue extracts (cytosols) contain, besides soluble tissue proteins, large amounts of plasma proteins. The extent of this plasma contamination can be determined by measuring the albumin concentration in cytosols by immunodiffusion. In cytosols of 4 different human target tissues the albumin content varied from 20-30% corresponding to an even higher whole plasma concentration. Steroid binding plasma proteins, such as CBG and SHBG are constituents of this containment. (author)

  9. Intracellular uptake and distribution of radiolabeled iodovinly deoxy uridine (IVDU) for gene therapy monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Choi, T. H.; Lee, T. S.; Lee, S. J.; Woo, K. S.; Jeon, W. S.; Choi, C. W.; Yim, S. M. [KCCH, Seoul (Korea, Republic of)

    2001-05-01

    We have evaluated a useful synthetic radiolabeled nucleoside substrate, (E)-5-2(2-[125I] idodovinyl) uracil deoxyuridine (IVDU), for herpes simplex virus type-1 thymidine kinase (HSV1-TK). Cellular uptake of these labeled compounds was observed in vitro. low uptake was showed in MCA cell line and high uptake was observed in Herpes simplex virus type-1 thymidine kinase(HSV1-tk) gene tranduced MCA(MCA-tk) cell line. Intracellular distribution of {sup 125}I-IVDU was differently occured in the MCA and MCA-TK cell line, respectively. Main distribution of MCA cells is in cytosol, and that of MCA-TK cells was in mitochondria and nuclei. For HSV1-tk system. We confirmed that IVDU was incorporated into DNA synthesis.

  10. Integrating Protein Engineering and Bioorthogonal Click Conjugation for Extracellular Vesicle Modulation and Intracellular Delivery.

    Directory of Open Access Journals (Sweden)

    Ming Wang

    Full Text Available Exosomes are small, cell-secreted vesicles that transfer proteins and genetic information between cells. This intercellular transmission regulates many physiological and pathological processes. Therefore, exosomes have emerged as novel biomarkers for disease diagnosis and as nanocarriers for drug delivery. Here, we report an easy-to-adapt and highly versatile methodology to modulate exosome composition and conjugate exosomes for intracellular delivery. Our strategy combines the metabolic labeling of newly synthesized proteins or glycan/glycoproteins of exosome-secreting cells with active azides and bioorthogonal click conjugation to modify and functionalize the exosomes. The azide-integrated can be conjugated to a variety of small molecules and proteins and can efficiently deliver conjugates into cells. The metabolic engineering of exosomes diversifies the chemistry of exosomes and expands the functions that can be introduced into exosomes, providing novel, powerful tools to study the roles of exosomes in biology and expand the biomedical potential of exosomes.

  11. New perspective in the assessment of total intracellular magnesium

    Directory of Open Access Journals (Sweden)

    Azzurra Sargenti

    2014-01-01

    Full Text Available Magnesium (Mg is essential for biological processes, but its cellular homeostasis has not been thoroughly elucidated, mainly because of the inadequacy of the available techniques to map intracellular Mg distribution. Recently, particular interest has been raised by a new family of fluorescent probes, diaza-18-crown-hydroxyquinoline (DCHQ, that shows remarkably high affinity and specificity for Mg, thus permitting the detection of the total intracellular Mg. The data obtained by fluori- metric and cytofluorimetric assays performed with DCHQ5 are in good agreement with atomic absorption spectroscopy, confirming that DCHQ5 probe allows both qualitative and quantitative determination of total intracellular Mg.

  12. Mobility and height detection of particle labels in an optical evanescent wave biosensor with single-label resolution

    Energy Technology Data Exchange (ETDEWEB)

    Van Ommering, Kim; Koets, Marjo; Schleipen, Jean J H B; Prins, Menno W J [Philips Research Laboratories, 5656 AE Eindhoven (Netherlands); Somers, Philip A; Van IJzendoorn, Leo J, E-mail: menno.prins@philips.co [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands)

    2010-04-21

    Particle labels are used in biosensors to detect the presence and concentration of analyte molecules. In this paper we demonstrate an optical technique to measure the mobility and height of bound particle labels on a biosensor surface with single-label resolution. The technique is based on the detection of the particle-induced light scattering in an optical evanescent field. We show that the thermal particle motion in the optical evanescent field leads to intensity fluctuations that can accurately be detected. The technique is demonstrated using 290 bp (99 nm) DNA as an analyte and using polystyrene particles and magnetic particles with diameters between 500 and 1000 nm as labels. The particle intensity histograms show that quantitative height measurements are obtained for particles with uniform optical properties, and the intensity versus position plots reflect the analyte-antibody orientation and the analyte flexibility. The novel optical detection technique will lead to biosensors with very high sensitivity and specificity.

  13. A tunable ratiometric pH sensor based on carbon nanodots for the quantitative measurement of the intracellular pH of whole cells.

    Science.gov (United States)

    Shi, Wen; Li, Xiaohua; Ma, Huimin

    2012-06-25

    The whole picture: Carbon nanodots labeled with two fluorescent dyes have been developed as a tunable ratiometric pH sensor to measure intracellular pH. The nanosensor shows good biocompatibility and cellular dispersibility. Quantitative determinations on intact HeLa cells and pH fluctuations associated with oxidative stress were performed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Indirect Radiohalogenation of Targeting Proteins: Labelling Chemistry and Biological Characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Orlova, Anna

    2003-03-01

    preserves the binding properties of proteins, long intracellular retention of radioactivity in targeted cells and quick release of radiohalogenated catabolites from the blood circulation. Radiohalogenation of proteins using indirect methods was studied, including optimisation of labelling chemistry and biological characterisation of some labelled conjugates. Two groups for indirect radiohalogenation were used, representing two different labelling principles: activated ester of benzoic acid (1) and the derivative of closo-dodecaborate anion (2). The non-phenolic linker (1) as well as the borate-halogen moiety (2) probably prevent dehalogenation. The negative charge of the potential catabolic products of (2) might trap radiohalogens intracellularly.

  15. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    DEFF Research Database (Denmark)

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...

  16. Detection and Measurement of the Intracellular Calcium Variation in Follicular Cells

    Directory of Open Access Journals (Sweden)

    Ana M. Herrera-Navarro

    2014-01-01

    Full Text Available This work presents a new method for measuring the variation of intracellular calcium in follicular cells. The proposal consists in two stages: (i the detection of the cell’s nuclei and (ii the analysis of the fluorescence variations. The first stage is performed via watershed modified transformation, where the process of labeling is controlled. The detection process uses the contours of the cells as descriptors, where they are enhanced with a morphological filter that homogenizes the luminance variation of the image. In the second stage, the fluorescence variations are modeled as an exponential decreasing function, where the fluorescence variations are highly correlated with the changes of intracellular free Ca2+. Additionally, it is introduced a new morphological called medium reconstruction process, which helps to enhance the data for the modeling process. This filter exploits the undermodeling and overmodeling properties of reconstruction operators, such that it preserves the structure of the original signal. Finally, an experimental process shows evidence of the capabilities of the proposal.

  17. Multiple-Targeted Graphene-based Nanocarrier for Intracellular Imaging of mRNAs

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Li, Zhaohui; Liu, Misha; Hu, Dehong; Lin, Yuehe; Li, Jinghong

    2017-08-29

    Simultaneous detection and imaging of multiple intracellular messenger RNA (mRNAs) hold great significant for early cancer diagnostics and preventive medicine development. Herein, we propose a multiple-targeted graphene oxide (GO) nanocarrier that can simultaneously detect and image different type mRNAs in living cells. First of all, in vitro detection of multiple targets have been realized successfully based on the multiple-targeted GO nanocarrier with linear relationship ranging from 3 nM to 200 nM, as well as sensitive detection limit of 1.84 nM for manganese superoxide dismutase (Mn-SOD) mRNA and 2.45 nM for β-actin mRNA. Additionally, this nanosensing platform composed of fluorescent labeled single strand DNA probes and GO nanocarrier can identify Mn-SOD mRNA and endogenous mRNA of β-actin in living cancer cells, showing rapid response, high specificity, nuclease stability, and good biocompatibility during the cell imaging. Thirdly, changes of the expression levels of mRNA in living cells before or after the drug treatment can be monitored successfully. By using multiple ssDNA as probes and GO nanocarrier as the cellular delivery cargo, the proposed simultaneous multiple-targeted sensing platform will be of great potential as a powerful tool for intracellular trafficking process from basic research to clinical diagnosis.

  18. The Intracellular Destiny of the Protein Corona: A Study on its Cellular Internalization and Evolution.

    Science.gov (United States)

    Bertoli, Filippo; Garry, David; Monopoli, Marco P; Salvati, Anna; Dawson, Kenneth A

    2016-11-22

    It has been well established that the early stages of nanoparticle-cell interactions are governed, at least in part, by the layer of proteins and other biomolecules adsorbed and slowly exchanged with the surrounding biological media (biomolecular corona). Subsequent to membrane interactions, nanoparticles are typically internalized into the cell and trafficked along defined pathways such as, in many cases, the endolysosomal pathway. Indeed, if the original corona is partially retained on the nanoparticle surface, the biomolecules in this layer may play an important role in determining subsequent cellular processing. In this work, using a combination of organelle separation and fluorescence labeling of the initial extracellular corona, we clarify its intracellular evolution as nanoparticles travel within the cell. We show that specific proteins present in the original protein corona are retained on the nanoparticles until they accumulate in lysosomes, and, once there, they are degraded. We also report on how different bare surfaces (amino and carboxyl modified) affect the details of this evolution. One overarching discovery is that the same serum proteins can exhibit different intracellular processing when carried inside cells by nanoparticles, as components of their corona, compared to what is observed when they are transported freely from the extracellular medium.

  19. A Gold Nanoparticle Bio-Optical Transponder to Dynamically Monitor Intracellular pH.

    Science.gov (United States)

    Carnevale, Kate J F; Riskowski, Ryan A; Strouse, Geoffrey F

    2018-06-13

    A pH-sensitive bio-optical transponder (pH-BOT) capable of simultaneously reporting the timing of intracellular DNA cargo release from a gold nanoparticle (AuNP) and the evolving intracellular pH (pH i) during endosomal maturation is demonstrated. The pH-BOT is designed with a triple-dye-labeled duplex DNA appended to a 6.6 nm AuNP, utilizing pH-responsive fluorescein paired with DyLight405 as a surface energy transfer (SET) coupled dye pair to ratiometrically report the pH at and after cargo release. A non-SET-coupled dye, DyLight 700, is used to provide dynamic tracking throughout the experiment. The pH-BOT beacon of the cargo uptake, release, and processing was visualized using live-cell confocal fluorescent microscopy in Chinese hamster ovary cells, and it was observed that while maturation of endosomes carrying pH-BOT is slowed significantly, the pH-BOT is distributed throughout the endolysosomal system while remaining at pH ∼6. This observed decoupling of endosomal maturation from acidification lends support to those models that propose that pH alone is not sufficient to explain endosomal maturation and may enable greater insight into our understanding of the fundamental processes of biology.

  20. Review of nutrition labeling formats.

    Science.gov (United States)

    Geiger, C J; Wyse, B W; Parent, C R; Hansen, R G

    1991-07-01

    This article examines nutrition labeling history as well as the findings of nine research studies of nutrition labeling formats. Nutrition labeling regulations were announced in 1973 and have been periodically amended since then. In response to requests from consumers and health care professionals for revision of the labeling system, the Food and Drug Administration initiated a three-phase plan for reform of nutrition labeling in 1990. President Bush signed the Nutrition Labeling and Education Act in November 1990. Literature analysis revealed that only nine studies with an experimental design have focused on nutrition labeling since 1971. Four were conducted before 1975, which was the year that nutrition labeling was officially implemented, two were conducted in 1980, and three were conducted after 1986. Only two of the nine studies supported the traditional label format mandated by the Code of Federal Regulations, and one study partially supported it. Four of the nine studies that evaluated graphic presentations of nutrition information found that consumer comprehension of nutrition information was improved with a graphic format for nutrition labeling: three studies supported the use of bar graphs and one study supported the use of a pie chart. Full disclosure (ie, complete nutrient and ingredient labeling) was preferred by consumers in two of the three studies that examined this variable. The third study supported three types of information disclosure dependent upon socioeconomic class. In those studies that tested graphics, a bar graph format was significantly preferred and showed better consumer comprehension than the traditional format.

  1. Linerless label device and method

    KAUST Repository

    Binladen, Abdulkari

    2016-01-14

    This apparatus and method for applying a linerless label to an end user product includes a device with a printer for printing on a face surface of a linerless label, and a release coat applicator for applying a release coat to the face surface of the label; another device including an unwinder unit (103) to unwind a roll of printed linerless label; a belt (108); a glue applicator (102) for applying glue to the belt; a nip roller (106) for contacting and applying pressure to the face surface of the linerless label such that the glue on the belt transfers to the back surface of the linerless label; at least one slitting knife 105) positioned downstream the belt and a rewinder unit (104) positioned downstream the slitting knife; and a third device which die cuts and applies the linerless label to an end user object.

  2. Intracellular trafficking of new anticancer therapeutics: antibody–drug conjugates

    Science.gov (United States)

    Kalim, Muhammad; Chen, Jie; Wang, Shenghao; Lin, Caiyao; Ullah, Saif; Liang, Keying; Ding, Qian; Chen, Shuqing; Zhan, Jinbiao

    2017-01-01

    Antibody–drug conjugate (ADC) is a milestone in targeted cancer therapy that comprises of monoclonal antibodies chemically linked to cytotoxic drugs. Internalization of ADC takes place via clathrin-mediated endocytosis, caveolae-mediated endocytosis, and pinocytosis. Conjugation strategies, endocytosis and intracellular trafficking optimization, linkers, and drugs chemistry present a great challenge for researchers to eradicate tumor cells successfully. This inventiveness of endocytosis and intracellular trafficking has given considerable momentum recently to develop specific antibodies and ADCs to treat cancer cells. It is significantly advantageous to emphasize the endocytosis and intracellular trafficking pathways efficiently and to design potent engineered conjugates and biological entities to boost efficient therapies enormously for cancer treatment. Current studies illustrate endocytosis and intracellular trafficking of ADC, protein, and linker strategies in unloading and also concisely evaluate practically applicable ADCs. PMID:28814834

  3. Intracellular trafficking of new anticancer therapeutics: antibody-drug conjugates.

    Science.gov (United States)

    Kalim, Muhammad; Chen, Jie; Wang, Shenghao; Lin, Caiyao; Ullah, Saif; Liang, Keying; Ding, Qian; Chen, Shuqing; Zhan, Jinbiao

    2017-01-01

    Antibody-drug conjugate (ADC) is a milestone in targeted cancer therapy that comprises of monoclonal antibodies chemically linked to cytotoxic drugs. Internalization of ADC takes place via clathrin-mediated endocytosis, caveolae-mediated endocytosis, and pinocytosis. Conjugation strategies, endocytosis and intracellular trafficking optimization, linkers, and drugs chemistry present a great challenge for researchers to eradicate tumor cells successfully. This inventiveness of endocytosis and intracellular trafficking has given considerable momentum recently to develop specific antibodies and ADCs to treat cancer cells. It is significantly advantageous to emphasize the endocytosis and intracellular trafficking pathways efficiently and to design potent engineered conjugates and biological entities to boost efficient therapies enormously for cancer treatment. Current studies illustrate endocytosis and intracellular trafficking of ADC, protein, and linker strategies in unloading and also concisely evaluate practically applicable ADCs.

  4. EVIDENCE FOR THE MACROPHAGE INDUCING GENE IN MYCOBACTERIUM INTRACELLULARE

    Science.gov (United States)

    Background: The Mycobacterium avium Complex (MAC) includes the species M. avium (MA), M. intracellulare (MI), and possibly others. Organisms belonging to the MAC are phylogenetically closely related, opportunistic pathogens. The macrophage inducing gene (mig) is the only well-des...

  5. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina Lundgaard; Login, Frédéric H.; Jensen, Helene Halkjær

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacteria...

  6. Intracellular sodium hydrogen exchange inhibition and clinical myocardial protection.

    Science.gov (United States)

    Mentzer, Robert M; Lasley, Robert D; Jessel, Andreas; Karmazyn, Morris

    2003-02-01

    Although the mechanisms underlying ischemia/reperfusion injury remain elusive, evidence supports the etiologic role of intracellular calcium overload and oxidative stress induced by reactive oxygen species. Activation of the sodium hydrogen exchanger (NHE) is associated with intracellular calcium accumulation. Inhibition of the NHE-1 isoform may attenuate the consequences of this injury. Although there is strong preclinical and early clinical evidence that NHE inhibitors may be cardioprotective, definitive proof of this concept in humans awaits the results of ongoing clinical trials.

  7. Uptake and intracellular activity of AM-1155 in phagocytic cells.

    Science.gov (United States)

    Yamamoto, T; Kusajima, H; Hosaka, M; Fukuda, H; Oomori, Y; Shinoda, H

    1996-01-01

    The uptake and intracellular activity of AM-1155 in murine J774.1 macrophages and human polymorphonuclear leukocytes were investigated. AM-1155 penetrated phagocytic cells rapidly and reversibly, although the penetration process was not affected by metabolic inhibitors such as sodium fluoride, cyanide m-chlorophenylhydrazone, or ouabain or by nucleoside transport system inhibitors such as adenosine. The intracellular concentration-to-extracellular concentration ratio of AM-1155 in both cell types of phagocytes ranged from 5 to 7. These ratios were almost equal to those for sparfloxacin. The intracellular activity of AM-1155 in J774.1 macrophages, examined with Staphylococcus aureus 209P as a test bacterium, was dependent on the extracellular concentration. AM-1155 at a concentration of 1 microgram/ml reduced the number of viable cells of S. aureus ingested by more than 90%. The intracellular activity of AM-1155 was more potent than those of sparfloxacin, ofloxacin, ciprofloxacin, flomoxef, and erythromycin. These results suggest that the potent intracellular activity of AM-1155 might mainly be due to the high intracellular concentration and its potent in vitro activity. PMID:9124835

  8. Epithelial Cell Gene Expression Induced by Intracellular Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Xianglu Li

    2009-01-01

    Full Text Available HEp-2 cell monolayers were cocultured with intracellular Staphylococcus aureus, and changes in gene expression were profiled using DNA microarrays. Intracellular S. aureus affected genes involved in cellular stress responses, signal transduction, inflammation, apoptosis, fibrosis, and cholesterol biosynthesis. Transcription of stress response and signal transduction-related genes including atf3, sgk, map2k1, map2k3, arhb, and arhe was increased. In addition, elevated transcription of proinflammatory genes was observed for tnfa, il1b, il6, il8, cxcl1, ccl20, cox2, and pai1. Genes involved in proapoptosis and fibrosis were also affected at transcriptional level by intracellular S. aureus. Notably, intracellular S. aureus induced strong transcriptional down-regulation of several cholesterol biosynthesis genes. These results suggest that epithelial cells respond to intracellular S. aureus by inducing genes affecting immunity and in repairing damage caused by the organism, and are consistent with the possibility that the organism exploits an intracellular environment to subvert host immunity and promote colonization.

  9. Mesenchymal stromal cell labeling by new uncoated superparamagnetic maghemite nanoparticles in comparison with commercial Resovist – an initial in vitro study

    Directory of Open Access Journals (Sweden)

    Skopalik J

    2014-11-01

    Full Text Available Josef Skopalik,1 Katerina Polakova,2 Marketa Havrdova,2 Ivan Justan,1 Massimiliano Magro,3 David Milde,2 Lucia Knopfova,4 Jan Smarda,4 Helena Polakova,1 Eva Gabrielova,5 Fabio Vianello,2,3 Jaroslav Michalek,1 Radek Zboril21Department of Pharmacology, Masaryk University, Brno, Czech Republic; 2Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry and Analytical Chemistry, Faculty of Science, Palacky University, Olomouc, Czech Republic; 3Department of Comparative Biomedicine and Food Science, University of Padua, Padova, Italy; 4Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic; 5Department of Medical Chemistry and Biochemistry, Faculty of Medicine, Palacky University, Olomouc, Czech RepublicObjective: Cell therapies have emerged as a promising approach in medicine. The basis of each therapy is the injection of 1–100×106 cells with regenerative potential into some part of the body. Mesenchymal stromal cells (MSCs are the most used cell type in the cell therapy nowadays, but no gold standard for the labeling of the MSCs for magnetic resonance imaging (MRI is available yet. This work evaluates our newly synthesized uncoated superparamagnetic maghemite nanoparticles (surface-active maghemite nanoparticles – SAMNs as an MRI contrast intracellular probe usable in a clinical 1.5 T MRI system.Methods: MSCs from rat and human donors were isolated, and then incubated at different concentrations (10–200 µg/mL of SAMN maghemite nanoparticles for 48 hours. Viability, proliferation, and nanoparticle uptake efficiency were tested (using fluorescence microscopy, xCELLigence analysis, atomic absorption spectroscopy, and advanced microscopy techniques. Migration capacity, cluster of differentiation markers, effect of nanoparticles on long-term viability, contrast properties in MRI, and cocultivation of labeled cells with myocytes were also studied.Results: SAMNs do not

  10. Easy labeling of proliferative phase and sporogonic phase of microsporidia Nosema bombycis in host cells.

    Directory of Open Access Journals (Sweden)

    Jie Chen

    Full Text Available Microsporidia are eukaryotic, unicellular parasites that have been studied for more than 150 years. These organisms are extraordinary in their ability to invade a wide range of hosts including vertebrates and invertebrates, such as human and commercially important animals. A lack of appropriate labeling methods has limited the research of the cell cycle and protein locations in intracellular stages. In this report, an easy fluorescent labeling method has been developed to mark the proliferative and sporogonic phases of microsporidia Nosema bombycis in host cells. Based on the presence of chitin, Calcofluor White M2R was used to label the sporogonic phase, while β-tubulin antibody coupled with fluorescence secondary antibody were used to label the proliferative phase by immunofluorescence. This method is simple, efficient and can be used on both infected cells and tissue slices, providing a great potential application in microsporidia research.

  11. Labelled compounds. (Pt. B)

    International Nuclear Information System (INIS)

    Buncel, E.; Jones, J.R.

    1991-01-01

    Since the end of World War II there has been a tremendous increase in the number of compounds that have been synthesized with radioactive or stable isotopes. They have found application in many diverse fields, so much so, that hardly a single area in pure and applied science has not benefited. Not surprisingly it has been reflected in appearance of related publications. The early proceedings of the Symposia on Advances in Trace Methodology were soon followed by various Euratom sponsored meetings in which methods of preparing and storing labelled compounds featured prominently. In due course a resurgence of interest in stable isotopes, brought about by their greater availability (also lower cost) and partly by development of new techniques such as gas chromatography - mass spectrometry (gc-ms), led to the publication of proceedings of several successful conferences. More recently conferences dealing with the synthesis and applications of isotopes and isotopically labelled compounds have been established on a regular basis. In addition to the proceedings of conferences and journal publications individuals left their mark by producing definitive texts, usually on specific nuclides. Only the classic two volume publication of Murray and Williams (Organic syntheses with isotopes, New York 1985), now over 30 years old and out of print, attempted to do justice to several nuclides. With the large amount of work that has been undertaken since then it seems unlikely that an updated edition could be produced. The alternative strategy was to ask scientists currently active to review specific areas and this is the approach adopted in the present series of monographs. In this way it is intended to cover the broad advances that have been made in the synthesis and applications of isotopes and isotopically labelled compounds in the physical and biomedical sciences. (author). refs.; figs.; tabs

  12. From Label to Practice

    DEFF Research Database (Denmark)

    Byrkjeflot, Haldor; Strandgaard, Jesper; Svejenova, Silviya

    2013-01-01

    because NNC was conceived as an identity movement, triggered by active involvement of entrepreneurial leaders from the culinary profession, high-profile political supporters, legitimating scientists, disseminating media, and interpreting audiences. It was facilitated by three mechanisms: First, the use......This article examines the process of creation of new Nordic cuisine (NNC) as a culinary innovation, focusing on the main stages, actors, and mechanisms that shaped the new label and its practices and facilitated its diffusion in the region and internationally. Fast-paced diffusion was possible...

  13. Improving labeling efficiency in automatic quality control of MRSI data.

    Science.gov (United States)

    Pedrosa de Barros, Nuno; McKinley, Richard; Wiest, Roland; Slotboom, Johannes

    2017-12-01

    To improve the efficiency of the labeling task in automatic quality control of MR spectroscopy imaging data. 28'432 short and long echo time (TE) spectra (1.5 tesla; point resolved spectroscopy (PRESS); repetition time (TR)= 1,500 ms) from 18 different brain tumor patients were labeled by two experts as either accept or reject, depending on their quality. For each spectrum, 47 signal features were extracted. The data was then used to run several simulations and test an active learning approach using uncertainty sampling. The performance of the classifiers was evaluated as a function of the number of patients in the training set, number of spectra in the training set, and a parameter α used to control the level of classification uncertainty required for a new spectrum to be selected for labeling. The results showed that the proposed strategy allows reductions of up to 72.97% for short TE and 62.09% for long TE in the amount of data that needs to be labeled, without significant impact in classification accuracy. Further reductions are possible with significant but minimal impact in performance. Active learning using uncertainty sampling is an effective way to increase the labeling efficiency for training automatic quality control classifiers. Magn Reson Med 78:2399-2405, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  14. Label and Label-Free Detection Techniques for Protein Microarrays

    Directory of Open Access Journals (Sweden)

    Amir Syahir

    2015-04-01

    Full Text Available Protein microarray technology has gone through numerous innovative developments in recent decades. In this review, we focus on the development of protein detection methods embedded in the technology. Early microarrays utilized useful chromophores and versatile biochemical techniques dominated by high-throughput illumination. Recently, the realization of label-free techniques has been greatly advanced by the combination of knowledge in material sciences, computational design and nanofabrication. These rapidly advancing techniques aim to provide data without the intervention of label molecules. Here, we present a brief overview of this remarkable innovation from the perspectives of label and label-free techniques in transducing nano‑biological events.

  15. Change in CD3 positive T-cell expression in psoriatic arthritis synovium correlates with change in DAS28 and magnetic resonance imaging synovitis scores following initiation of biologic therapy--a single centre, open-label study.

    LENUS (Irish Health Repository)

    Pontifex, Eliza K

    2011-01-01

    With the development of increasing numbers of potential therapeutic agents in inflammatory disease comes the need for effective biomarkers to help screen for drug efficacy and optimal dosing regimens early in the clinical trial process. This need has been recognized by the Outcome Measures in Rheumatology Clinical Trials (OMERACT) group, which has established guidelines for biomarker validation. To seek a candidate synovial biomarker of treatment response in psoriatic arthritis (PsA), we determined whether changes in immunohistochemical markers of synovial inflammation correlate with changes in disease activity scores assessing 28 joints (ΔDAS28) or magnetic resonance imaging synovitis scores (ΔMRI) in patients with PsA treated with a biologic agent.

  16. Comparison of the biological effects of {sup 18}F at different intracellular levels

    Energy Technology Data Exchange (ETDEWEB)

    Kashino, Genro, E-mail: kashino@oita-u.ac.jp [Advanced Molecular Imaging Center, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan); Hayashi, Kazutaka; Douhara, Kazumasa [Advanced Molecular Imaging Center, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan); Kobashigawa, Shinko; Mori, Hiromu [Department of Radiology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan)

    2014-11-07

    Highlights: • We estimated the inductions of DNA DSB in cell treated with {sup 18}F-FDG. • We found that inductions of DNA DSB are dependent on accumulation of {sup 18}F in cell. • Accumulation of {sup 18}F in cell may be indispensable for risk estimation of PET. - Abstract: We herein examined the biological effects of cells treated with {sup 18}F labeled drugs for positron emission tomography (PET). The relationship between the intracellular distribution of {sup 18}F and levels of damaged DNA has yet to be clarified in detail. We used culture cells (Chinese Hamster Ovary cells) treated with two types of {sup 18}F labeled drugs, fluorodeoxyglucose (FDG) and fluorine ion (HF). FDG efficiently accumulated in cells, whereas HF did not. To examine the induction of DNA double strand breaks (DSB), we measured the number of foci for 53BP1 that formed at the site of DNA DSB. The results revealed that although radioactivity levels were the same, the induction of 53BP1 foci was stronger in cells treated with {sup 18}F-FDG than in those treated with {sup 18}F-HF. The clonogenic survival of cells was significantly lower with {sup 18}F-FDG than with {sup 18}F-HF. We concluded that the efficient accumulation of {sup 18}F in cells led to stronger biological effects due to more severe cellular lethality via the induction of DNA DSB.

  17. Distance labeling schemes for trees

    DEFF Research Database (Denmark)

    Alstrup, Stephen; Gørtz, Inge Li; Bistrup Halvorsen, Esben

    2016-01-01

    We consider distance labeling schemes for trees: given a tree with n nodes, label the nodes with binary strings such that, given the labels of any two nodes, one can determine, by looking only at the labels, the distance in the tree between the two nodes. A lower bound by Gavoille et al. [Gavoille...... variants such as, for example, small distances in trees [Alstrup et al., SODA, 2003]. We improve the known upper and lower bounds of exact distance labeling by showing that 1/4 log2(n) bits are needed and that 1/2 log2(n) bits are sufficient. We also give (1 + ε)-stretch labeling schemes using Theta...

  18. Magnets and magnetic materials

    International Nuclear Information System (INIS)

    Meuris, Ch.; Rifflet, J.M.

    2007-01-01

    The Large Hadron Collider (LHC), the world's largest highest-energy particle collider that the CERN plans to commission in 2008, gets a double boost from superconducting magnet technology. Superconducting magnets are first used to guide the particles scheduled for collision through the accelerator, and then to observe the events triggered by the collision inside giant detectors in a known magnetic field. Despite the installation's massive dimensions, all this is done with minimal expenditure of energy. (author)

  19. Co-Labeling for Multi-View Weakly Labeled Learning.

    Science.gov (United States)

    Xu, Xinxing; Li, Wen; Xu, Dong; Tsang, Ivor W

    2016-06-01

    It is often expensive and time consuming to collect labeled training samples in many real-world applications. To reduce human effort on annotating training samples, many machine learning techniques (e.g., semi-supervised learning (SSL), multi-instance learning (MIL), etc.) have been studied to exploit weakly labeled training samples. Meanwhile, when the training data is represented with multiple types of features, many multi-view learning methods have shown that classifiers trained on different views can help each other to better utilize the unlabeled training samples for the SSL task. In this paper, we study a new learning problem called multi-view weakly labeled learning, in which we aim to develop a unified approach to learn robust classifiers by effectively utilizing different types of weakly labeled multi-view data from a broad range of tasks including SSL, MIL and relative outlier detection (ROD). We propose an effective approach called co-labeling to solve the multi-view weakly labeled learning problem. Specifically, we model the learning problem on each view as a weakly labeled learning problem, which aims to learn an optimal classifier from a set of pseudo-label vectors generated by using the classifiers trained from other views. Unlike traditional co-training approaches using a single pseudo-label vector for training each classifier, our co-labeling approach explores different strategies to utilize the predictions from different views, biases and iterations for generating the pseudo-label vectors, making our approach more robust for real-world applications. Moreover, to further improve the weakly labeled learning on each view, we also exploit the inherent group structure in the pseudo-label vectors generated from different strategies, which leads to a new multi-layer multiple kernel learning problem. Promising results for text-based image retrieval on the NUS-WIDE dataset as well as news classification and text categorization on several real-world multi

  20. Labelled molecules, modern research implements

    International Nuclear Information System (INIS)

    Pichat, L.; Langourieux, Y.

    1974-01-01

    Details of the synthesis of carbon 14- and tritium-labelled molecules are examined. Although the methods used are those of classical organic chemistry the preparation of carbon 14-labelled molecules differs in some respects, most noticeably in the use of 14 CO 2 which requires very special handling techniques. For the tritium labelling of organic molecules the methods are somewhat different, very often involving exchange reactions. The following are described in turn: the so-called Wilzbach exchange method; exchange by catalysis in solution; catalytic hydrogenation with tritium; reductions with borotritides. Some applications of labelled molecules in organic chemistry, biochemistry and pharmacology are listed [fr

  1. pH-Switch Nanoprecipitation of Polymeric Nanoparticles for Multimodal Cancer Targeting and Intracellular Triggered Delivery of Doxorubicin.

    Science.gov (United States)

    Herranz-Blanco, Bárbara; Shahbazi, Mohammad-Ali; Correia, Alexandra R; Balasubramanian, Vimalkumar; Kohout, Tomáš; Hirvonen, Jouni; Santos, Hélder A

    2016-08-01

    Theranostic nanoparticles are emerging as potent tools for noninvasive diagnosis, treatment, and monitoring of solid tumors. Herein, an advanced targeted and multistimuli responsive theranostic platform is presented for the intracellular triggered delivery of doxorubicin. The system consists of a polymeric-drug conjugate solid nanoparticle containing encapsulated superparamagnetic iron oxide nanoparticles (IO@PNP) and decorated with a tumor homing peptide, iRGD. The production of this nanosystem is based on a pH-switch nanoprecipitation method in organic-free solvents, making it ideal for biomedical applications. The nanosystem shows sufficient magnetization saturation for magnetically guided therapy along with reduced cytotoxicity and hemolytic effects. IO@PNP are largely internalized by endothelial and metastatic cancer cells and iRGD decorated IO@PNP moderately enhance their internalization into endothelial cells, while no enhancement is found for the metastatic cancer cells. Poly(ethylene glycol)-block-poly(histidine) with pH-responsive and proton-sponge properties promotes prompt lysosomal escape once the nanoparticles are endocyted. In addition, the polymer-doxorubicin conjugate solid nanoparticles show both intracellular lysosomal escape and efficient translocation of doxorubicin to the nuclei of the cells via cleavage of the amide bond. Overall, IO@PNP-doxorubicin and the iRGD decorated counterpart demonstrate to enhance the toxicity of doxorubicin in cancer cells by improving the intracellular delivery of the drug carried in the IO@PNP. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Cell internalizable and intracellularly degradable cationic polyurethane micelles as a potential platform for efficient imaging and drug delivery.

    Science.gov (United States)

    Ding, Mingming; Zeng, Xin; He, Xueling; Li, Jiehua; Tan, Hong; Fu, Qiang

    2014-08-11

    A cell internalizable and intracellularly degradable micellar system, assembled from multiblock polyurethanes bearing cell-penetrating gemini quaternary ammonium pendent groups in the side chain and redox-responsive disulfide linkages throughout the backbone, was developed for potential magnetic resonance imaging (MRI) and drug delivery. The nanocarrier is featured as a typical "cleavable core-internalizable shell-protective corona" architecture, which exhibits small size, positive surface charge, high loading capacity, and reduction-triggered destabilization. Furthermore, it can rapidly enter tumor cells and release its cargo in response to an intracellular level of glutathione, resulting in enhanced drug efficacy in vitro. The magnetic micelles loaded with superparamagnetic iron oxide (SPIO) nanoparticles demonstrate excellent MRI contrast enhancement, with T2 relaxivity found to be affected by the morphology of SPIO-clustering inside the micelle core. The multifunctional carrier with good cytocompatibility and nontoxic degradation products can serve as a promising theranostic candidate for efficient intracellular delivery of anticancer drugs and real-time monitoring of therapeutic effect.

  3. A Fluorogenic TMP-tag for High Signal-to-Background Intracellular Live Cell Imaging

    Science.gov (United States)

    Jing, Chaoran

    2013-01-01

    Developed to compliment the use of fluorescent proteins in live cell imaging, chemical tags enjoy the benefit of modular incorporation of organic fluorophores, opening the possibility of high photon output and special photophysical properties. However, the theoretical challenge in using chemical tags as opposed to fluorescent proteins for high-resolution imaging is background noise from unbound and/or non-specifically bound ligand-fluorophore. We envisioned we could overcome this limit by engineering fluorogenic trimethoprim-based chemical tags (TMP-tags) in which the fluorophore is quenched until binding with E. coli dihydrofolate reductase (eDHFR) tagged protein displaces the quencher. Thus, we began by building a non-fluorogenic, covalent TMP-tag based on a proximity-induced reaction known to achieve rapid and specific labeling both in vitro and inside of living cells. Here we take the final step and render the covalent TMP-tag fluorogenic. In brief, we designed a trimeric TMP-fluorophore-quencher molecule (TMP-Q-Atto520) with the quencher attached to a leaving group that, upon TMP binding to eDHFR, would be cleaved by a cysteine residue (Cys) installed just outside the binding pocket of eDHFR. We present the in vitro experiments showing that the eDHFR:L28C nucleophile cleaves the TMP-Q-Atto520 rapidly and efficiently, resulting in covalent labeling and remarkable fluorescence enhancement. Most significantly, while only our initial design, TMP-Q-Atto520 achieved the demanding goal of not only labeling highly abundant, localized intracellular proteins, but also less abundant, more dynamic cytoplasmic proteins. These results suggest that fluorogenic TMP-tag can significantly impact highresolution live cell imaging and further establish the potential of proximity-induced reactivity and organic chemistry more broadly as part of the growing toolbox for synthetic biology and cell engineering. PMID:23745575

  4. New Developments in Spin Labels for Pulsed Dipolar EPR

    Directory of Open Access Journals (Sweden)

    Alistair J. Fielding

    2014-10-01

    Full Text Available Spin labelling is a chemical technique that enables the integration of a molecule containing an unpaired electron into another framework for study. Given the need to understand the structure, dynamics, and conformational changes of biomacromolecules, spin labelling provides a relatively non-intrusive technique and has certain advantages over X-ray crystallography; which requires high quality crystals. The technique relies on the design of binding probes that target a functional group, for example, the thiol group of a cysteine residue within a protein. The unpaired electron is typically supplied through a nitroxide radical and sterically shielded to preserve stability. Pulsed electron paramagnetic resonance (EPR techniques allow small magnetic couplings to be measured (e.g., <50 MHz providing information on single label probes or the dipolar coupling between multiple labels. In particular, distances between spin labels pairs can be derived which has led to many protein/enzymes and nucleotides being studied. Here, we summarise recent examples of spin labels used for pulse EPR that serve to illustrate the contribution of chemistry to advancing discoveries in this field.

  5. Relevance of intracellular polarity to accuracy of eukaryotic chemotaxis

    International Nuclear Information System (INIS)

    Hiraiwa, Tetsuya; Nishikawa, Masatoshi; Shibata, Tatsuo; Nagamatsu, Akihiro; Akuzawa, Naohiro

    2014-01-01

    Eukaryotic chemotaxis is usually mediated by intracellular signals that tend to localize at the front or back of the cell. Such intracellular polarities frequently require no extracellular guidance cues, indicating that spontaneous polarization occurs in the signal network. Spontaneous polarization activity is considered relevant to the persistent motions in random cell migrations and chemotaxis. In this study, we propose a theoretical model that connects spontaneous intracellular polarity and motile ability in a chemoattractant solution. We demonstrate that the intracellular polarity can enhance the accuracy of chemotaxis. Chemotactic accuracy should also depend on chemoattractant concentration through the concentration-dependent correlation time in the polarity direction. Both the polarity correlation time and the chemotactic accuracy depend on the degree of responsiveness to the chemical gradient. We show that optimally accurate chemotaxis occurs at an intermediate responsiveness of intracellular polarity. Experimentally, we find that the persistence time of randomly migrating Dictyostelium cells depends on the chemoattractant concentration, as predicted by our theory. At the optimum responsiveness, this ameboid cell can enhance its chemotactic accuracy tenfold. (paper)

  6. Intracellular calcium levels can regulate Importin-dependent nuclear import

    International Nuclear Information System (INIS)

    Kaur, Gurpreet; Ly-Huynh, Jennifer D.; Jans, David A.

    2014-01-01

    Highlights: • High intracellular calcium inhibits Impα/β1- or Impβ1-dependent nuclear protein import. • The effect of Ca 2+ on nuclear import does not relate to changes in the nuclear pore. • High intracellular calcium can result in mislocalisation of Impβ1, Ran and RCC1. - Abstract: We previously showed that increased intracellular calcium can modulate Importin (Imp)β1-dependent nuclear import of SRY-related chromatin remodeling proteins. Here we extend this work to show for the first time that high intracellular calcium inhibits Impα/β1- or Impβ1-dependent nuclear protein import generally. The basis of this relates to the mislocalisation of the transport factors Impβ1 and Ran, which show significantly higher nuclear localization in contrast to various other factors, and RCC1, which shows altered subnuclear localisation. The results here establish for the first time that intracellular calcium modulates conventional nuclear import through direct effects on the nuclear transport machinery

  7. Intracellular transport of fat-soluble vitamins A and E.

    Science.gov (United States)

    Kono, Nozomu; Arai, Hiroyuki

    2015-01-01

    Vitamins are compounds that are essential for the normal growth, reproduction and functioning of the human body. Of the 13 known vitamins, vitamins A, D, E and K are lipophilic compounds and are therefore called fat-soluble vitamins. Because of their lipophilicity, fat-soluble vitamins are solubilized and transported by intracellular carrier proteins to exert their actions and to be metabolized properly. Vitamin A and its derivatives, collectively called retinoids, are solubilized by intracellular retinoid-binding proteins such as cellular retinol-binding protein (CRBP), cellular retinoic acid-binding protein (CRABP) and cellular retinal-binding protein (CRALBP). These proteins act as chaperones that regulate the metabolism, signaling and transport of retinoids. CRALBP-mediated intracellular retinoid transport is essential for vision in human. α-Tocopherol, the main form of vitamin E found in the body, is transported by α-tocopherol transfer protein (α-TTP) in hepatic cells. Defects of α-TTP cause vitamin E deficiency and neurological disorders in humans. Recently, it has been shown that the interaction of α-TTP with phosphoinositides plays a critical role in the intracellular transport of α-tocopherol and is associated with familial vitamin E deficiency. In this review, we summarize the mechanisms and biological significance of the intracellular transport of vitamins A and E. © 2014 The Authors. Traffic published by John Wiley & Sons Ltd.

  8. Exploring anti-bacterial compounds against intracellular Legionella.

    Directory of Open Access Journals (Sweden)

    Christopher F Harrison

    Full Text Available Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an 'accidental' human pathogen and cause a severe pneumonia known as Legionnaires' disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoebacastellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target.

  9. Surveillance for Intracellular Antibody by Cytosolic Fc Receptor TRIM21

    Directory of Open Access Journals (Sweden)

    William A. McEwan

    2016-11-01

    Full Text Available TRIM21 has emerged as an atypical Fc receptor that is broadly conserved and widely expressed in the cytoplasm of mammalian cells. Viruses that traffic surface-bound antibodies into the cell during infection recruit TRIM21 via a high affinity interaction between Fc and TRIM21 PRYSPRY domain. Following binding of intracellular antibody, TRIM21 acts as both antiviral effector and sensor for innate immune signalling. These activities serve to reduce viral replication by orders of magnitude in vitro and contribute to host survival during in vivo infection. Neutralization occurs rapidly after detection and requires the activity of the ubiquitin-proteasome system. The microbial targets of this arm of intracellular immunity are still being identified: TRIM21 activity has been reported following infection by several non-enveloped viruses and intracellular bacteria. These findings extend the sphere of influence of antibodies to the intracellular domain and have broad implications for immunity. TRIM21 has been implicated in the chronic auto-immune condition systemic lupus erythematosus and is itself an auto-antigen in Sjögren’s syndrome. This review summarises our current understanding of TRIM21’s role as a cytosolic Fc receptor and briefly discusses pathological circumstances where intracellular antibodies have been described, or are hypothesized to occur, and may benefit from further investigations of the role of TRIM21.

  10. Advances in genetic manipulation of obligate intracellular bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Paul eBeare

    2011-05-01

    Full Text Available Infections by obligate intracellular bacterial pathogens result in significant morbidity and mortality worldwide. These bacteria include Chlamydia spp., which causes millions of cases of sexually transmitted disease and blinding trachoma annually, and members of the α-proteobacterial genera Anaplasma, Ehrlichia, Orientia and Rickettsia, agents of serious human illnesses including epidemic typhus. Coxiella burnetii, the agent of human Q fever, has also been considered a prototypical obligate intracellular bacterium, but recent host cell-free (axenic growth has rescued it from obligatism. The historic genetic intractability of obligate intracellular bacteria has severely limited molecular dissection of their unique lifestyles and virulence factors involved in pathogenesis. Host cell restricted growth is a significant barrier to genetic transformation that can make simple procedures for free-living bacteria, such as cloning, exceedingly difficult. Low transformation efficiency requiring long term culture in host cells to expand small transformant populations is another obstacle. Despite numerous technical limitations, the last decade has witnessed significant gains in genetic manipulation of obligate intracellular bacteria including allelic exchange. Continued development of genetic tools should soon enable routine mutation and complementation strategies for virulence factor discovery and stimulate renewed interest in these refractory pathogens. In this review, we discuss the technical challenges associated with genetic transformation of obligate intracellular bacteria and highlight advances made with individual genera.

  11. Exploring Anti-Bacterial Compounds against Intracellular Legionella

    Science.gov (United States)

    Harrison, Christopher F.; Kicka, Sébastien; Trofimov, Valentin; Berschl, Kathrin; Ouertatani-Sakouhi, Hajer; Ackermann, Nikolaus; Hedberg, Christian; Cosson, Pierre; Soldati, Thierry; Hilbi, Hubert

    2013-01-01

    Legionella pneumophila is a ubiquitous fresh-water bacterium which reproduces within its erstwhile predators, environmental amoeba, by subverting the normal pathway of phagocytosis and degradation. The molecular mechanisms which confer resistance to amoeba are apparently conserved and also allow replication within macrophages. Thus, L. pneumophila can act as an ‘accidental’ human pathogen and cause a severe pneumonia known as Legionnaires’ disease. The intracellular localisation of L. pneumophila protects it from some antibiotics, and this fact must be taken into account to develop new anti-bacterial compounds. In addition, the intracellular lifestyle of L. pneumophila may render the bacteria susceptible to compounds diminishing bacterial virulence and decreasing intracellular survival and replication of this pathogen. The development of a single infection cycle intracellular replication assay using GFP-producing L. pneumophila and Acanthamoeba castellanii amoeba is reported here. This fluorescence-based assay allows for continuous monitoring of intracellular replication rates, revealing the effect of bacterial gene deletions or drug treatment. To examine how perturbations of the host cell affect L. pneumophila replication, several known host-targeting compounds were tested, including modulators of cytoskeletal dynamics, vesicle scission and Ras GTPase localisation. Our results reveal a hitherto unrealized potential antibiotic property of the β-lactone-based Ras depalmitoylation inhibitor palmostatin M, but not the closely related inhibitor palmostatin B. Further characterisation indicated that this compound caused specific growth inhibition of Legionella and Mycobacterium species, suggesting that it may act on a common bacterial target. PMID:24058631

  12. Intracellular calcium levels can regulate Importin-dependent nuclear import

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Gurpreet; Ly-Huynh, Jennifer D.; Jans, David A., E-mail: David.Jans@monash.edu

    2014-07-18

    Highlights: • High intracellular calcium inhibits Impα/β1- or Impβ1-dependent nuclear protein import. • The effect of Ca{sup 2+} on nuclear import does not relate to changes in the nuclear pore. • High intracellular calcium can result in mislocalisation of Impβ1, Ran and RCC1. - Abstract: We previously showed that increased intracellular calcium can modulate Importin (Imp)β1-dependent nuclear import of SRY-related chromatin remodeling proteins. Here we extend this work to show for the first time that high intracellular calcium inhibits Impα/β1- or Impβ1-dependent nuclear protein import generally. The basis of this relates to the mislocalisation of the transport factors Impβ1 and Ran, which show significantly higher nuclear localization in contrast to various other factors, and RCC1, which shows altered subnuclear localisation. The results here establish for the first time that intracellular calcium modulates conventional nuclear import through direct effects on the nuclear transport machinery.

  13. Intracellular renin disrupts chemical communication between heart cells. Pathophysiological implications

    Directory of Open Access Journals (Sweden)

    Walmor eDe Mello

    2015-01-01

    Full Text Available The influence of intracellular renin on the process of chemical communication between cardiac cells was investigated in cell pairs isolated from the left ventricle of adult Wistar Kyoto rats. The enzyme together with Lucifer yellow CH was dialyzed into one cell of the pair using the whole cell clamp technique. The diffusion of the dye in the dialyzed and in non-dialyzed cell was followed by measuring the intensity of fluorescence in both cells as a function of time. The results indicated that; 1 under normal conditions, Lucifer Yellow flows from cell-to-cell through gap junctions; 2 the intracellular dialysis of renin (100nM disrupts chemical communication-an effect enhanced by simultaneous administration of angiotensinogen (100nM; 3 enalaprilat (10-9M administered to the cytosol together with renin reduced drastically the uncoupling action of the enzyme; 4 aliskiren (10-8M inhibited the effect of renin on chemical communication;5 the possible role of intracellular renin independently of angiotensin II (Ang II was evaluated including the increase of the inward calcium current elicited by the enzyme and the possible role of oxidative stress on the disruption of cell communication; 6 the possible harmful versus the beneficial effect of intracellular renin during myocardial infarction was discussed;7 the present results indicate that intracellular renin due to internalization or in situ synthesis, causes a severe impairment of chemical communication in the heart resulting in derangement of metabolic cooperation with serious consequences for heart function.

  14. Self-organization of intracellular gradients during mitosis

    Directory of Open Access Journals (Sweden)

    Fuller Brian G

    2010-01-01

    Full Text Available Abstract Gradients are used in a number of biological systems to transmit spatial information over a range of distances. The best studied are morphogen gradients where information is transmitted over many cell lengths. Smaller mitotic gradients reflect the need to organize several distinct events along the length of the mitotic spindle. The intracellular gradients that characterize mitosis are emerging as important regulatory paradigms. Intracellular gradients utilize intrinsic auto-regulatory feedback loops and diffusion to establish stable regions of activity within the mitotic cytosol. We review three recently described intracellular mitotic gradients. The Ran GTP gradient with its elaborate cascade of nuclear transport receptors and cargoes is the best characterized, yet the dynamics underlying the robust gradient of Ran-GTP have received little attention. Gradients of phosphorylation have been observed on Aurora B kinase substrates both before and after anaphase onset. In both instances the phosphorylation gradient appears to result from a soluble gradient of Aurora B kinase activity. Regulatory properties that support gradient formation are highlighted. Intracellular activity gradients that regulate localized mitotic events bare several hallmarks of self-organizing biologic systems that designate spatial information during pattern formation. Intracellular pattern formation represents a new paradigm in mitotic regulation.

  15. Magnetism and magnetic materials

    International Nuclear Information System (INIS)

    1990-01-01

    It describes the actual status of physics in Brazil concerning the study of magnetism and magnetic materials. It gives an overview of different research groups in Brazil, their needs, as well as the investments needed to improve the area. (A.C.A.S.)

  16. Maximum likelihood pixel labeling using a spatially variant finite mixture model

    International Nuclear Information System (INIS)

    Gopal, S.S.; Hebert, T.J.

    1996-01-01

    We propose a spatially-variant mixture model for pixel labeling. Based on this spatially-variant mixture model we derive an expectation maximization algorithm for maximum likelihood estimation of the pixel labels. While most algorithms using mixture models entail the subsequent use of a Bayes classifier for pixel labeling, the proposed algorithm yields maximum likelihood estimates of the labels themselves and results in unambiguous pixel labels. The proposed algorithm is fast, robust, easy to implement, flexible in that it can be applied to any arbitrary image data where the number of classes is known and, most importantly, obviates the need for an explicit labeling rule. The algorithm is evaluated both quantitatively and qualitatively on simulated data and on clinical magnetic resonance images of the human brain

  17. Quantifying intracellular hydrogen peroxide perturbations in terms of concentration

    Directory of Open Access Journals (Sweden)

    Beijing K. Huang

    2014-01-01

    Full Text Available Molecular level, mechanistic understanding of the roles of reactive oxygen species (ROS in a variety of pathological conditions is hindered by the difficulties associated with determining the concentration of various ROS species. Here, we present an approach that converts fold-change in the signal from an intracellular sensor of hydrogen peroxide into changes in absolute concentration. The method uses extracellular additions of peroxide and an improved biochemical measurement of the gradient between extracellular and intracellular peroxide concentrations to calibrate the intracellular sensor. By measuring peroxiredoxin activity, we found that this gradient is 650-fold rather than the 7–10-fold that is widely cited. The resulting calibration is important for understanding the mass-action kinetics of complex networks of redox reactions, and it enables meaningful characterization and comparison of outputs from endogenous peroxide generating tools and therapeutics across studies.

  18. Simple Recovery of Intracellular Gold Nanoparticles from Peanut Seedling Roots.

    Science.gov (United States)

    Raju, D; Mehta, Urmil J; Ahmad, Absar

    2015-02-01

    Fabrication of inorganic nanomaterials via a biological route witnesses the formation either extracellularly, intracellulary or both. Whereas extracellular formation of these nanomaterials is cherished owing to their easy and economical extraction and purification processes; the intracellular formation of nanomaterials, due to the lack of a proper recovery protocol has always been dreaded, as the extraction processes used so far were tedious, costly, time consuming and often resulting in very low recovery. The aim of the present study was to overcome the problems related with the extraction and recovery of intracellularly synthesized inorganic nanoparticles, and to devise a method to increasing the output, the shape, size, composition and dispersal of nanoparticles is not altered. Water proved to be much better system as it provided well dispersed, stable gold nanoparticles and higher recovery. This is the first report, where intracellular nanoparticles have been recovered using a very cost-effective and eco-friendly approach.

  19. Radioactive decay and labeled compounds

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter on radioactive decay and labeled compounds has numerous intext equations and worked, sample problems. Topics covered include the following: terms and mathematics of radioactive decay; examples of calculations; graphs of decay equations; radioactivity or activity; activity measurements; activity decay; half-life determinations; labeled compounds. A 20 problem set is also included. 1 ref., 4 figs., 1 tab

  20. Linerless label device and method

    KAUST Repository

    Binladen, Abdulkari

    2016-01-01

    This apparatus and method for applying a linerless label to an end user product includes a device with a printer for printing on a face surface of a linerless label, and a release coat applicator for applying a release coat to the face surface

  1. Nutrition Marketing on Food Labels

    Science.gov (United States)

    Colby, Sarah E.; Johnson, LuAnn; Scheett, Angela; Hoverson, Bonita

    2010-01-01

    Objective: This research sought to determine how often nutrition marketing is used on labels of foods that are high in saturated fat, sodium, and/or sugar. Design and Setting: All items packaged with food labels (N = 56,900) in all 6 grocery stores in Grand Forks, ND were surveyed. Main Outcome Measure(s): Marketing strategy, nutrient label…

  2. 188Re labeled MPEG-modified superparamagnetic nanogels: preparation and preliminary application in mice

    International Nuclear Information System (INIS)

    Sun Hanwen; Gong Peijun; Liu Xiuqing; Hong Jun; Xu Dongmei; Zhang Chunfu; Wang Yongxian; Yao Side

    2005-01-01

    Superparamagnetic poly(acrylamide) magnetic nanogels produced via photochemical method have been developed. After Hoffmann degradation of carbonyl, the nanogels with amino groups, or poly(acrylamide-vinyl amine) magnetic nanogels, were also obtained. And the magnetic nanogels were further modified by methoxy poly(ethylene glycol) (MPEG) for higher dispersibility and stability. The MPEG-modified magnetic nanogels were characterized by X-ray diffraction (XRD), photo correlation spectroscopy (PCS) and scanning electron microscopy (SEM), respectively. The MPEG-modified magnetic nanogels were labeled by 188 Re radiopharmaceuticals and intravenously injected into tails of mice in the presence and absence of a 0.5 T external magnetic field targeted on the bellies. The radioactivity distribution was monitored in vivo. In the absence of magnetic field, the radioactivity was mainly distributed in liver, spleen, kidney, stomach and lung. In the presence of the magnetic field, the radioactivity was mainly accumulated on the targeted point, verifying the magnetically targeted character. (authors)

  3. Detection of magnetic nanoparticles with magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Jia Wenyan [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Xu, Guizhi [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Department of Biomedical Engineering, Hebei University of Technology, Tianjin, 300130 (China); Sclabassi, Robert J. [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Zhu Jiangang [Department of Electrical and Computer Engineering, Carnegie Melon University, Pittsburgh, PA 15213 (United States); Bagic, Anto [Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Sun Mingui [Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15260 (United States)], E-mail: mrsun@neuronet.pitt.edu

    2008-04-15

    Superconducting quantum interference devices (SQUIDs) have been widely utilized in biomedical applications due to their extremely high sensitivity to magnetic signals. The present study explores the feasibility of a new type of nanotechnology-based imaging method using standard clinical magnetoencephalographic (MEG) systems equipped with SQUID sensors. Previous studies have shown that biological targets labeled with non-toxic, magnetized nanoparticles can be imaged by measuring the magnetic field generated by these particles. In this work, we demonstrate that (1) the magnetic signals from certain nanoparticles can be detected without magnetization using standard clinical MEG, (2) for some types of nanoparticles, only bound particles produce detectable signals, and (3) the magnetic field of particles several hours after magnetization is significantly stronger than that of un-magnetized particles. These findings hold promise in facilitating the potential application of magnetic nanoparticles to in vivo tumor imaging. The minimum amount of nanoparticles that produce detectable signals is predicted by theoretical modeling and computer simulation.

  4. 21 CFR 201.70 - Calcium labeling.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Calcium labeling. 201.70 Section 201.70 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.70 Calcium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the calcium content per...

  5. 49 CFR 172.450 - EMPTY label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false EMPTY label. 172.450 Section 172.450... SECURITY PLANS Labeling § 172.450 EMPTY label. (a) Each EMPTY label, except for size, must be as follows....) in height. (2) The label must be white with black printing. (b) [Reserved] ...

  6. 21 CFR 610.60 - Container label.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Container label. 610.60 Section 610.60 Food and... GENERAL BIOLOGICAL PRODUCTS STANDARDS Labeling Standards § 610.60 Container label. (a) Full label. The following items shall appear on the label affixed to each container of a product capable of bearing a full...

  7. 49 CFR 172.442 - CORROSIVE label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false CORROSIVE label. 172.442 Section 172.442... SECURITY PLANS Labeling § 172.442 CORROSIVE label. (a) Except for size and color, the CORROSIVE label must... CORROSIVE label must be white in the top half and black in the lower half. [Amdt. 172-123, 56 FR 66259, Dec...

  8. 16 CFR 460.12 - Labels.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Labels. 460.12 Section 460.12 Commercial....12 Labels. If you are a manufacturer, you must label all packages of your insulation. The labels must... chart. Labels for these products must state the minimum net weight of the insulation in the package. You...

  9. 49 CFR 172.441 - FISSILE label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false FISSILE label. 172.441 Section 172.441... SECURITY PLANS Labeling § 172.441 FISSILE label. (a) Except for size and color, the FISSILE label must be... FISSILE label must be white. [69 FR 3669, Jan. 26, 2004] ...

  10. 49 CFR 172.426 - OXIDIZER label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false OXIDIZER label. 172.426 Section 172.426... SECURITY PLANS Labeling § 172.426 OXIDIZER label. (a) Except for size and color, the OXIDIZER label must be... OXIDIZER label must be yellow. [Amdt. 172-123, 56 FR 66257, Dec. 20, 1991] ...

  11. A better carbon footprint label

    DEFF Research Database (Denmark)

    Thøgersen, John; Nielsen, Kristian S.

    2016-01-01

    , participants saw the original Carbon Trust label and in the other condition they saw the same label, but with traffic light colors added to communicate the product’s relative performance in terms of carbon footprint. All included attributes were found to have a significant impact on consumer choices....... As expected, price and carbon footprint were negatively related to choice. Further, participants preferred organic to non-organic coffee and certification by a public authority. The effect of the carbon label is significantly stronger the more environmentally concerned the consumer is. Using colors...... to indicate relative carbon footprint significantly increases carbon label effectiveness. Hence, a carbon footprint label is more effective if it uses traffic light colors to communicate the product’s relative performance....

  12. Tethering factors as organizers of intracellular vesicular traffic.

    Science.gov (United States)

    Yu, I-Mei; Hughson, Frederick M

    2010-01-01

    Intracellular trafficking entails the budding, transport, tethering, and fusion of transport vesicles and other membrane carriers. Here we review recent progress toward a mechanistic understanding of vesicle tethering. The known tethering factors are large complexes important for one or more intracellular trafficking pathways and are capable of interacting directly with many of the other principal components of the cellular trafficking machinery. Our review emphasizes recent developments in the in vitro reconstitution of vesicle tethering and the structural characterization of multisubunit tethering factors. The combination of these and other approaches has led to exciting progress toward understanding how these essential nanomachines work.

  13. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms.

    Science.gov (United States)

    Pareja, Maria Eugenia Mansilla; Colombo, Maria I

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance.

  14. Application of magnetic carriers to two examples of quantitative cell analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Chen; Qian, Zhixi; Choi, Young Suk; David, Allan E. [Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, AL 36849 (United States); Todd, Paul, E-mail: pwtodd@hotmail.com [Techshot, Inc., 7200 Highway 150, Greenville, IN 47124 (United States); Hanley, Thomas R. [Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, AL 36849 (United States)

    2017-04-01

    The use of magnetophoretic mobility as a surrogate for fluorescence intensity in quantitative cell analysis was investigated. The objectives of quantitative fluorescence flow cytometry include establishing a level of labeling for the setting of parameters in fluorescence activated cell sorters (FACS) and the determination of levels of uptake of fluorescently labeled substrates by living cells. Likewise, the objectives of quantitative magnetic cytometry include establishing a level of labeling for the setting of parameters in flowing magnetic cell sorters and the determination of levels of uptake of magnetically labeled substrates by living cells. The magnetic counterpart to fluorescence intensity is magnetophoretic mobility, defined as the velocity imparted to a suspended cell per unit of magnetic ponderomotive force. A commercial velocimeter available for making this measurement was used to demonstrate both applications. Cultured Gallus lymphoma cells were immunolabeled with commercial magnetic beads and shown to have adequate magnetophoretic mobility to be separated by a novel flowing magnetic separator. Phagocytosis of starch nanoparticles having magnetic cores by cultured Chinese hamster ovary cells, a CHO line, was quantified on the basis of magnetophoretic mobility. - Highlights: • Commercial particle tracking velocimetry measures magnetophoretic mobility of labeled cells. • Magnetically labeled tumor cells were shown to have adequate mobility for capture in a specific sorter. • The kinetics of nonspecific endocytosis of magnetic nanomaterials by CHO cells was characterized. • Magnetic labeling of cells can be used like fluorescence flow cytometry for quantitative cell analysis.

  15. Change in CD3 positive T-cell expression in psoriatic arthritis synovium correlates with change in DAS28 and magnetic resonance imaging synovitis scores following initiation of biologic therapy - a single centre, open-label study

    LENUS (Irish Health Repository)

    Pontifex, Eliza K

    2011-01-27

    Abstract Introduction With the development of increasing numbers of potential therapeutic agents in inflammatory disease comes the need for effective biomarkers to help screen for drug efficacy and optimal dosing regimens early in the clinical trial process. This need has been recognized by the Outcome Measures in Rheumatology Clinical Trials (OMERACT) group, which has established guidelines for biomarker validation. To seek a candidate synovial biomarker of treatment response in psoriatic arthritis (PsA), we determined whether changes in immunohistochemical markers of synovial inflammation correlate with changes in disease activity scores assessing 28 joints (ΔDAS28) or magnetic resonance imaging synovitis scores (ΔMRI) in patients with PsA treated with a biologic agent. Methods Twenty-five consecutive patients with PsA underwent arthroscopic synovial biopsies and MRI scans of an inflamed knee joint at baseline and 12 weeks after starting treatment with either anakinra (first 10 patients) or etanercept (subsequent 15 patients) in two sequential studies of identical design. DAS28 scores were measured at both time points. Immunohistochemical staining for CD3, CD68 and Factor VIII (FVIII) was performed on synovial samples and scored by digital image analysis (DIA). MRI scans performed at baseline and at 12 weeks were scored for synovitis semi-quantitatively. The ΔDAS28 of the European League Against Rheumatism good response definition (>1.2) was chosen to divide patients into responder and non-responder groups. Differences between groups (Mann Whitney U test) and correlations between ΔDAS28 with change in immunohistochemical and MRI synovitis scores (Spearman\\'s rho test) were calculated. Results Paired synovial samples and MRI scans were available for 21 patients (8 anakinra, 13 etanercept) and 23 patients (8 anakinra, 15 etanercept) respectively. Change in CD3 (ΔCD3) and CD68 expression in the synovial sublining layer (ΔCD68sl) was significantly greater in

  16. Applications of magnetic nanoparticles in biomedicine

    International Nuclear Information System (INIS)

    Pankhurst, Q A; Connolly, J; Jones, S K; Dobson, J

    2003-01-01

    The physical principles underlying some current biomedical applications of magnetic nanoparticles are reviewed. Starting from well-known basic concepts, and drawing on examples from biology and biomedicine, the relevant physics of magnetic materials and their responses to applied magnetic fields are surveyed. The way these properties are controlled and used is illustrated with reference to (i) magnetic separation of labelled cells and other biological entities; (ii) therapeutic drug, gene and radionuclide delivery; (iii) radio frequency methods for the catabolism of tumours via hyperthermia; and (iv) contrast enhancement agents for magnetic resonance imaging applications. Future prospects are also discussed. (topical review)

  17. Quantification of the Intracellular Life Time of Water Molecules to Measure Transport Rates of Human Aquaglyceroporins.

    Science.gov (United States)

    Palmgren, Madelene; Hernebring, Malin; Eriksson, Stefanie; Elbing, Karin; Geijer, Cecilia; Lasič, Samo; Dahl, Peter; Hansen, Jesper S; Topgaard, Daniel; Lindkvist-Petersson, Karin

    2017-12-01

    Orthodox aquaporins are transmembrane channel proteins that facilitate rapid diffusion of water, while aquaglyceroporins facilitate the diffusion of small uncharged molecules such as glycerol and arsenic trioxide. Aquaglyceroporins play important roles in human physiology, in particular for glycerol metabolism and arsenic detoxification. We have developed a unique system applying the strain of the yeast Pichia pastoris, where the endogenous aquaporins/aquaglyceroporins have been removed and human aquaglyceroporins AQP3, AQP7, and AQP9 are recombinantly expressed enabling comparative permeability measurements between the expressed proteins. Using a newly established Nuclear Magnetic Resonance approach based on measurement of the intracellular life time of water, we propose that human aquaglyceroporins are poor facilitators of water and that the water transport efficiency is similar to that of passive diffusion across native cell membranes. This is distinctly different from glycerol and arsenic trioxide, where high glycerol transport efficiency was recorded.

  18. Self-assessed performance improves statistical fusion of image labels

    International Nuclear Information System (INIS)

    Bryan, Frederick W.; Xu, Zhoubing; Asman, Andrew J.; Allen, Wade M.; Reich, Daniel S.; Landman, Bennett A.

    2014-01-01

    Purpose: Expert manual labeling is the gold standard for image segmentation, but this process is difficult, time-consuming, and prone to inter-individual differences. While fully automated methods have successfully targeted many anatomies, automated methods have not yet been developed for numerous essential structures (e.g., the internal structure of the spinal cord as seen on magnetic resonance imaging). Collaborative labeling is a new paradigm that offers a robust alternative that may realize both the throughput of automation and the guidance of experts. Yet, distributing manual labeling expertise across individuals and sites introduces potential human factors concerns (e.g., training, software usability) and statistical considerations (e.g., fusion of information, assessment of confidence, bias) that must be further explored. During the labeling process, it is simple to ask raters to self-assess the confidence of their labels, but this is rarely done and has not been previously quantitatively studied. Herein, the authors explore the utility of self-assessment in relation to automated assessment of rater performance in the context of statistical fusion. Methods: The authors conducted a study of 66 volumes manually labeled by 75 minimally trained human raters recruited from the university undergraduate population. Raters were given 15 min of training during which they were shown examples of correct segmentation, and the online segmentation tool was demonstrated. The volumes were labeled 2D slice-wise, and the slices were unordered. A self-assessed quality metric was produced by raters for each slice by marking a confidence bar superimposed on the slice. Volumes produced by both voting and statistical fusion algorithms were compared against a set of expert segmentations of the same volumes. Results: Labels for 8825 distinct slices were obtained. Simple majority voting resulted in statistically poorer performance than voting weighted by self-assessed performance

  19. Self-assessed performance improves statistical fusion of image labels

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Frederick W., E-mail: frederick.w.bryan@vanderbilt.edu; Xu, Zhoubing; Asman, Andrew J.; Allen, Wade M. [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States); Reich, Daniel S. [Translational Neuroradiology Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892 (United States); Landman, Bennett A. [Electrical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States); Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37235 (United States); and Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2014-03-15

    Purpose: Expert manual labeling is the gold standard for image segmentation, but this process is difficult, time-consuming, and prone to inter-individual differences. While fully automated methods have successfully targeted many anatomies, automated methods have not yet been developed for numerous essential structures (e.g., the internal structure of the spinal cord as seen on magnetic resonance imaging). Collaborative labeling is a new paradigm that offers a robust alternative that may realize both the throughput of automation and the guidance of experts. Yet, distributing manual labeling expertise across individuals and sites introduces potential human factors concerns (e.g., training, software usability) and statistical considerations (e.g., fusion of information, assessment of confidence, bias) that must be further explored. During the labeling process, it is simple to ask raters to self-assess the confidence of their labels, but this is rarely done and has not been previously quantitatively studied. Herein, the authors explore the utility of self-assessment in relation to automated assessment of rater performance in the context of statistical fusion. Methods: The authors conducted a study of 66 volumes manually labeled by 75 minimally trained human raters recruited from the university undergraduate population. Raters were given 15 min of training during which they were shown examples of correct segmentation, and the online segmentation tool was demonstrated. The volumes were labeled 2D slice-wise, and the slices were unordered. A self-assessed quality metric was produced by raters for each slice by marking a confidence bar superimposed on the slice. Volumes produced by both voting and statistical fusion algorithms were compared against a set of expert segmentations of the same volumes. Results: Labels for 8825 distinct slices were obtained. Simple majority voting resulted in statistically poorer performance than voting weighted by self-assessed performance

  20. The epithelial cell cytoskeleton and intracellular trafficking. I. Shiga toxin B-subunit system: retrograde transport, intracellular vectorization, and more.

    Science.gov (United States)

    Johannes, Ludger

    2002-07-01

    Many intracellular transport routes are still little explored. This is particularly true for retrograde transport between the plasma membrane and the endoplasmic reticulum. Shiga toxin B subunit has become a powerful tool to study this pathway, and recent advances on the molecular mechanisms of transport in the retrograde route and on its physiological function(s) are summarized. Furthermore, it is discussed how the study of retrograde transport of Shiga toxin B subunit allows one to design new methods for the intracellular delivery of therapeutic compounds.

  1. Photoaffinity labeling of bacteriorhodopsin

    International Nuclear Information System (INIS)

    Ding, Weidong; Tsipouras, Athanasios; Ok, Hyun; Yamamoto, Toshihiro; Gawinowicz, M.A.; Nakanishi, Koji

    1990-01-01

    14 C-Labeled optically pure 3S- and 3R-(diazoacetoxy)-all-trans-retinals were incorporated separately into bacterioopsin to reconstitute functional bacteriorhodopsin (bR) analogues, 3S- and 3R-diazo-bRs. UV irradiation at 254 nm generated highly reactive carbenes, which cross-linked the radiolabeled retinals to amino acid residues in the vicinity of the β-ionone ring. The 3S- and 3R-diazo analogues were found to cross-link, respectively, to cyanogen bromide fragments CN 7/CN 9 and CN 8/CN 9. More specifically, Thr121 and Gly122 in fragment CN 7 were found to be cross-linked to the 3S-diazo analogue. The identification of cross-linked residues and fragments favors assignments of the seven helices A-G-F-E-D-C-B or B-C-D-E-F-G-A to helices 1-2-3-4-5-6-7 in the two-dimensional electron density map. The present results show that the chromophore chain is oriented with the ionone ring inclined toward the outside of the membrane (the 9-methyl group also faces the extracellular side of the membrane)

  2. Soil Fumigant Labels - Dimethyl Disulfide (DMDS)

    Science.gov (United States)

    Search by EPA registration number, product name, or company and follow the link to the Pesticide Product Labeling System (PPLS) for label details. Updated labels include new safety requirements for buffer zones and related measures.

  3. Mobile Application for Pesticide Label Matching

    Science.gov (United States)

    The label matching application will give inspectors the ability to instantly compare pesticide product labels against state and federal label databases via their cell phone, tablet or other mobile device.

  4. How to Read a Nutrition Facts Label

    Medline Plus

    Full Text Available ... Under Control Figuring Out Food Labels Healthy Food Shopping If My Child Has Food Allergies, What Should ... for Parents Figuring Out Food Labels Smart Supermarket Shopping Figuring Out Fat and Calories Food Labels View ...

  5. 21 CFR 1302.04 - Location and size of symbol on label and labeling.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Location and size of symbol on label and labeling... AND PACKAGING REQUIREMENTS FOR CONTROLLED SUBSTANCES § 1302.04 Location and size of symbol on label and labeling. The symbol shall be prominently located on the label or the labeling of the commercial...

  6. Regularized Label Relaxation Linear Regression.

    Science.gov (United States)

    Fang, Xiaozhao; Xu, Yong; Li, Xuelong; Lai, Zhihui; Wong, Wai Keung; Fang, Bingwu

    2018-04-01

    Linear regression (LR) and some of its variants have been widely used for classification problems. Most of these methods assume that during the learning phase, the training samples can be exactly transformed into a strict binary label matrix, which has too little freedom to fit the labels adequately. To address this problem, in this paper, we propose a novel regularized label relaxation LR method, which has the following notable characteristics. First, the proposed method relaxes the strict binary label matrix into a slack variable matrix by introducing a nonnegative label relaxation matrix into LR, which provides more freedom to fit the labels and simultaneously enlarges the margins between different classes as much as possible. Second, the proposed method constructs the class compactness graph based on manifold learning and uses it as the regularization item to avoid the problem of overfitting. The class compactness graph is used to ensure that the samples sharing the same labels can be kept close after they are transformed. Two different algorithms, which are, respectively, based on -norm and -norm loss functions are devised. These two algorithms have compact closed-form solutions in each iteration so that they are easily implemented. Extensive experiments show that these two algorithms outperform the state-of-the-art algorithms in terms of the classification accuracy and running time.

  7. Activation of protein kinase C alters the intracellular distribution and mobility of cardiac Na+ channels.

    Science.gov (United States)

    Hallaq, Haifa; Wang, Dao W; Kunic, Jennifer D; George, Alfred L; Wells, K Sam; Murray, Katherine T

    2012-02-01

    Na(+) current derived from expression of the cardiac isoform SCN5A is reduced by receptor-mediated or direct activation of protein kinase C (PKC). Previous work has suggested a possible role for loss of Na(+) channels at the plasma membrane in this effect, but the results are controversial. In this study, we tested the hypothesis that PKC activation acutely modulates the intracellular distribution of SCN5A channels and that this effect can be visualized in living cells. In human embryonic kidney cells that stably expressed SCN5A with green fluorescent protein (GFP) fused to the channel COOH-terminus (SCN5A-GFP), Na(+) currents were suppressed by an exposure to PKC activation. Using confocal microscopy, colocalization of SCN5A-GFP channels with the plasma membrane under control and stimulated conditions was quantified. A separate population of SCN5A channels containing an extracellular epitope was immunolabeled to permit temporally stable labeling of the plasma membrane. Our results demonstrated that Na(+) channels were preferentially trafficked away from the plasma membrane by PKC activation, with a major contribution by Ca(2+)-sensitive or conventional PKC isoforms, whereas stimulation of protein kinase A (PKA) had the opposite effect. Removal of the conserved PKC site Ser(1503) or exposure to the NADPH oxidase inhibitor apocynin eliminated the PKC-mediated effect to alter channel trafficking, indicating that both channel phosphorylation and ROS were required. Experiments using fluorescence recovery after photobleaching demonstrated that both PKC and PKA also modified channel mobility in a manner consistent with the dynamics of channel distribution. These results demonstrate that the activation of protein kinases can acutely regulate the intracellular distribution and molecular mobility of cardiac Na(+) channels in living cells.

  8. Hijacking of host cellular functions by an intracellular parasite, the microsporidian Anncaliia algerae.

    Directory of Open Access Journals (Sweden)

    Johan Panek

    Full Text Available Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how parasites hijack host cellular functions, we developed a SILAC (Stable Isotope Labeling by Amino Acids in Cell culture quantitative proteomics workflow. Our study focused on deciphering the cross-talk in a host-parasite association, involving human foreskin fibroblasts (HFF and the microsporidia Anncaliia algerae, a fungus related parasite with an obligate intracellular lifestyle and a strong host dependency. The host-parasite cross-talk was analyzed at five post-infection times 1, 6, 12 and 24 hours post-infection (hpi and 8 days post-infection (dpi. A significant up-regulation of four interferon-induced proteins with tetratricopeptide repeats IFIT1, IFIT2, IFIT3 and MX1 was observed at 8 dpi suggesting a type 1 interferon (IFN host response. Quantitative alteration of host proteins involved in biological functions such as signaling (STAT1, Ras and reduction of the translation activity (EIF3 confirmed a host type 1 IFN response. Interestingly, the SILAC approach also allowed the detection of 148 A. algerae proteins during the kinetics of infection. Among these proteins many are involved in parasite proliferation, and an over-representation of putative secreted effectors proteins was observed. Finally our survey also suggests that A. algerae could use a transposable element as a lure strategy to escape the host innate immune system.

  9. Development of a custom biological scaffold for investigating ultrasound-mediated intracellular delivery

    Energy Technology Data Exchange (ETDEWEB)

    Bui, Loan [Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76010 (United States); Aleid, Adham [Department of Biomedical Technology, King Saud University, Riyadh 12372 (Saudi Arabia); Alassaf, Ahmad [Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146 (United States); Department of Medical Equipment Technology, Majmaah University, Majmaah City 11952 (Saudi Arabia); Wilson, Otto C.; Raub, Christopher B. [Department of Biomedical Engineering, Catholic University of America, Washington, DC 20064 (United States); Frenkel, Victor, E-mail: vfrenkel@som.umaryland.edu [Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201 (United States)

    2017-01-01

    In vitro investigations of ultrasound mediated, intracellular drug and gene delivery (i.e. sonoporation) are typically carried out in cells cultured in standard plastic well plates. This creates conditions that poorly resemble in vivo conditions, as well as generating unwanted ultrasound phenomena that may confound the interpretation of results. Here, we present our results in the development of a biological scaffold for sonoporation studies. The scaffolds were comprised of cellulose fibers coated with chitosan and gelatin. Scaffold formulation was optimized for adherence and proliferation of mouse fibroblasts in terms of the ratio and relative concentration of the two constituents. The scaffolds were also shown to significantly reduce ultrasound reflections compared to the plastic well plates. A custom treatment chamber was designed and built, and the occurrence of acoustic cavitation in the chamber during the ultrasound treatments was detected; a requirement for the process of sonoporation. Finally, experiments were carried out to optimize the ultrasound exposures to minimize cellular damage. Ultrasound exposure was then shown to enable the uptake of 100 nm fluorescently labeled polystyrene nanoparticles in suspension into the cells seeded on scaffolds, compared to incubation of cell-seeded scaffolds with nanoparticles alone. These preliminary results set the basis for further development of this platform. They also provide motivation for the development of similar platforms for the controlled investigation of other ultrasound mediated cell and tissue therapies. - Highlights: • A custom, biological scaffold was developed, comprised of chitosan and gelatin. • The scaffold formulation was optimized for adhesion and proliferation of fibroblasts. • Investigations showed the scaffolds to be less reflective to ultrasound than plastic well plates. • The scaffolds were found to be suitable for investigations of ultrasound mediated intracellular nanoparticle

  10. Monitoring intracellular oxidative events using dynamic spectral unmixing microscopy

    Science.gov (United States)

    There is increasing interest in using live-cell imaging to monitor not just individual intracellular endpoints, but to investigate the interplay between multiple molecular events as they unfold in real time within the cell. A major impediment to simultaneous acquisition of multip...

  11. FLIPR assays of intracellular calcium in GPCR drug discovery

    DEFF Research Database (Denmark)

    Hansen, Kasper Bø; Bräuner-Osborne, Hans

    2009-01-01

    Fluorescent dyes sensitive to changes in intracellular calcium have become increasingly popular in G protein-coupled receptor (GPCR) drug discovery for several reasons. First of all, the assays using the dyes are easy to perform and are of low cost compared to other assays. Second, most non...

  12. Intracellular localization of Na + /H + antiporter from Malus zumi ...

    African Journals Online (AJOL)

    In this study, we examined the intracellular localization of the product of Na+/H+ antiporter gene (MzNHX1) cloned from Malus zumi. Analysis using yeast cells expressing a fusion protein of MzNHX1 and green fluorescent protein confirmed the localization of MzNHX1 on the tonoplast.

  13. Intracellular pH gradients in migrating cells

    DEFF Research Database (Denmark)

    Martin, Christine; Pedersen, Stine Helene Falsig; Schwab, Albrecht

    2011-01-01

    might function as such unevenly distributed regulators as they modulate the interaction of focal adhesion proteins and components of the cytoskeleton in vitro. However, an intracellular pH (pH(i)) gradient reflecting a spatial asymmetry of protons has not been shown so far. One major regulator of p...

  14. Structural rearrangement of the intracellular domains during AMPA receptor activation

    DEFF Research Database (Denmark)

    Zachariassen, Linda Grønborg; Katchan, Ljudmila; Jensen, Anna Guldvang

    2016-01-01

    -clamp fluorometry of the double- and single-insert constructs showed that both the intracellular C-terminal domain (CTD) and the loop region between the M1 and M2 helices move during activation and the CTD is detached from the membrane. Our time-resolved measurements revealed unexpectedly complex fluorescence...

  15. The interferon response to intracellular DNA: why so many receptors?

    Science.gov (United States)

    Unterholzner, Leonie

    2013-11-01

    The detection of intracellular DNA has emerged to be a key event in the innate immune response to viruses and intracellular bacteria, and during conditions of sterile inflammation and autoimmunity. One of the consequences of the detection of DNA as a 'stranger' and a 'danger' signal is the production of type I interferons and pro-inflammatory cytokines. Much work has been dedicated to the elucidation of the signalling cascades that activate this DNA-induced gene expression programme. However, while many proteins have been proposed to act as sensors for intracellular DNA in recent years, none has been met with universal acceptance, and a theory linking all the recent observations is, as yet, lacking. This review presents the evidence for the various interferon-inducing DNA receptors proposed to date, and examines the hypotheses that might explain why so many different receptors appear to be involved in the innate immune recognition of intracellular DNA. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. Manipulation of Host Cholesterol by Obligate Intracellular Bacteria

    Directory of Open Access Journals (Sweden)

    Dhritiman Samanta

    2017-05-01

    Full Text Available Cholesterol is a multifunctional lipid that plays important metabolic and structural roles in the eukaryotic cell. Despite having diverse lifestyles, the obligate intracellular bacterial pathogens Chlamydia, Coxiella, Anaplasma, Ehrlichia, and Rickettsia all target cholesterol during host cell colonization as a potential source of membrane, as well as a means to manipulate host cell signaling and trafficking. To promote host cell entry, these pathogens utilize cholesterol-rich microdomains known as lipid rafts, which serve as organizational and functional platforms for host signaling pathways involved in phagocytosis. Once a pathogen gains entrance to the intracellular space, it can manipulate host cholesterol trafficking pathways to access nutrient-rich vesicles or acquire membrane components for the bacteria or bacteria-containing vacuole. To acquire cholesterol, these pathogens specifically target host cholesterol metabolism, uptake, efflux, and storage. In this review, we examine the strategies obligate intracellular bacterial pathogens employ to manipulate cholesterol during host cell colonization. Understanding how obligate intracellular pathogens target and use host cholesterol provides critical insight into the host-pathogen relationship.

  17. Engineering of obligate intracellular bacteria: progress, challenges and paradigms

    Science.gov (United States)

    Over twenty years have passed since the first report of genetic manipulation of an obligate intracellular bacterium. Through progress interspersed by bouts of stagnation, microbiologists and geneticists have developed approaches to genetically manipulate obligates. A brief overview of the current ge...

  18. Galectin-3 guides intracellular trafficking of some human serotransferrin glycoforms

    DEFF Research Database (Denmark)

    Carlsson, Carl Michael; Bengtson, Per; Cucak, Helena

    2013-01-01

    these transferrin glycoforms differently after preloading with exogenously added galectin-3. In all, this study provides the first evidence of a functional role for transferrin glycans, in intracellular trafficking after uptake. Moreover, the galectin-3 bound glycoform increased in cancer, suggesting...

  19. Dihydroceramide biology - Structure-specific metabolism and intracellular localization

    NARCIS (Netherlands)

    Kok, JW; NikolovaKarakashian, M; Klappe, K; Alexander, C; Merrill, AH

    1997-01-01

    This study utilized fluorescent analogs to characterize the intracellular transport and metabolism of dihydroceramide (DN-Cer), an intermediate in de novo sphingolipid biosynthesis, When 6-[N-(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]hexanoyl-DH-Cer (C-6-NBD-DH-Cer) was incubated with HT29, NRK, BHK,

  20. CONTRIBUTIONS OF INTRACELLULAR IONS TO Kv CHANNEL VOLTAGE SENSOR DYNAMICS.

    Directory of Open Access Journals (Sweden)

    Samuel eGoodchild

    2012-06-01

    Full Text Available Voltage sensing domains of Kv channels control ionic conductance through coupling of the movement of charged residues in the S4 segment to conformational changes at the cytoplasmic region of the pore domain, that allow K+ ions to flow. Conformational transitions within the voltage sensing domain caused by changes in the applied voltage across the membrane field are coupled to the conducting pore region and the gating of ionic conductance. However, several other factors not directly linked to the voltage dependent movement of charged residues within the voltage sensor impact the dynamics of the voltage sensor, such as inactivation, ionic conductance, intracellular ion identity and block of the channel by intracellular ligands. The effect of intracellular ions on voltage sensor dynamics is of importance in the interpretation of gating current measurements and the physiology of pore/voltage sensor coupling. There is a significant amount of variability in the reported kinetics of voltage sensor deactivation kinetics of Kv channels attributed to different mechanisms such as open state stabilization, immobilization and relaxation processes of the voltage sensor. Here we separate these factors and focus on the causal role that intracellular ions can play in allosterically modulating the dynamics of Kv voltage sensor deactivation kinetics. These considerations are of critical importance in understanding the molecular determinants of the complete channel gating cycle from activation to deactivation.