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Sample records for die in-vivo messung

  1. Physik gestern und heute Die Messung elektrostatischer Kräfte

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-11-01

    Im Jahre 1785 veröffentlichte der französische Militäringenieur Charles Augustin Coulomb das Kraft-Abstand-Gesetz für elektrische Ladungen. Bereits zuvor hatte Henry Cavendish auf andere Art und Weise diese Beziehung nachgewiesen, aber nicht publiziert. Entsprechende Experimente wurden auch noch in jüngerer Zeit ausgeführt, da sie eine obere Abschätzung für die Ruhemasse des Photons erlauben.

  2. Messung und Analyse

    NASA Astrophysics Data System (ADS)

    Bathelt, Hartmut; Scheinhardt, Michael; Sell, Hendrik; Sottek, Roland; Guidati, Sandro; Helfer, Martin

    Für die Beurteilung von Akustik und Fahrkomfort eines Fahrzeugs gilt in der Fahrzeugentwicklung immer noch der alte Grundsatz: "Der Kunde fährt nicht am Prüfstand, sondern auf der Straße“. Daher werden Gesamtbeurteilungen des Entwicklungsstandes und Konkurrenzvergleiche (Benchmarking) nach wie vor auf der Straße durchgeführt, meist auf ausgewählten Fahrbahnen am Prüfgelände oder im Rahmen der regelmäßigen Winter- und Sommererprobungen unter extremen Witterungsverhältnissen.

  3. GEO 600 spitzt die Ohren. Der deutsche Gravitationswellendetektor erreicht seine geplante Empfindlichkeit

    NASA Astrophysics Data System (ADS)

    Borgeest, Ulf

    2005-04-01

    Die Physiker und Astronomen betreiben weltweit fünf große Laserinterferometer zur Messung von Gravitationswellen, darunter GEO 600 bei Hannover. Die hochempfindlichen Detektoren sollen helfen, die energiereichsten Vorgänge im Weltall aufzuklären und fundamentale physikalische Probleme zu lösen. Zur Zeit beginnen die ersten Messungen mit einer Empfindlichkeit, die astronomische Beobachtungen erlaubt.

  4. Dying cells program their expedient disposal: serum amyloid P component upregulation in vivo and in vitro induced by photodynamic therapy of cancer.

    PubMed

    Merchant, Soroush; Sun, Jinghai; Korbelik, Mladen

    2007-12-01

    Serum amyloid P component (SAP) is known as a prototypic acute phase reactant in the mouse and the protein that binds to dying cells securing their swift disposal by phagocytes. Treatment of solid tumors by photodynamic therapy (PDT) triggers SAP production in the liver of host mice, its release in the circulation and accumulation in PDT-targeted lesions. In the present study, mouse Lewis lung carcinoma (LLC) cells treated in vitro by PDT are shown to upregulate their gene encoding SAP. This effect was manifested following PDT treatment mediated by various types of photosensitizers (Photofrin, BPD, mTHPC, ALA). Generated SAP protein was not detected in tissue supernatants but remained localized to producing PDT-treated cells. The upregulation of SAP gene was observed also in untreated IC-21 macrophages after they were co-incubated for 4 h with PDT-treated LLC cells. Based on these findings, SAP that accumulates in PDT-treated tumors may originate from both systemic sources (released from the liver as acute phase reactant) and local sources; the latter could include tumor cells directly sustaining PDT injury and macrophages invading the tumor that become stimulated by signals from these affected tumor cells. Since SAP gene upregulation in LLC cells increased with the lethality of PDT dose used for their treatment, we propose that cells sensing they are inflicted with mortal injury can turn on molecular programs insuring not only that they die an innocuous form of death (apoptosis) but also that once they are dead their elimination is (facilitated by SAP) swift and efficient. PMID:18046483

  5. SPHERICAL DIE

    DOEpatents

    Livingston, J.P.

    1959-01-27

    A die is presented for pressing powdered materials into a hemispherical shape of uniforin density and wall thickness comprising a fcmale and male die element held in a stationary spaced relation with the space being equivalent to the wall thickness and defining the hemispherical shape, a pressing ring linearly moveable along the male die element, an inlet to fill the space with powdered materials, a guiding system for moving the pressing ring along the male die element so as to press the powdered material and a heating system for heating the male element so that the powdered material is heated while being pressed.

  6. Desmosomes In Vivo

    PubMed Central

    Garrod, David

    2010-01-01

    The structure, function, and regulation of desmosomal adhesion in vivo are discussed. Most desmosomes in tissues exhibit calcium-independent adhesion, which is strongly adhesive or “hyperadhesive”. This is fundamental to tissue strength. Almost all studies in culture are done on weakly adhesive, calcium-dependent desmosomes, although hyperadhesion can be readily obtained in confluent cell culture. Calcium dependence is a default condition in vivo, found in wounds and embryonic development. Hyperadhesion appears to be associated with an ordered arrangement of the extracellular domains of the desmosomal cadherins, which gives rise to the intercellular midline identified in ultrastructural studies. This in turn probably depends on molecular order in the desmosomal plaque. Protein kinase C downregulates hyperadhesion and there is preliminary evidence that it may also be regulated by tyrosine kinases. Downregulation of desmosomes in vivo may occur by internalisation of whole desmosomes rather than disassembly. Hyperadhesion has implications for diseases such as pemphigus. PMID:20671997

  7. Aptamer photoregulation in vivo

    PubMed Central

    Li, Lele; Tong, Rong; Chu, Hunghao; Wang, Weiping; Langer, Robert; Kohane, Daniel S.

    2014-01-01

    The in vivo application of aptamers as therapeutics could be improved by enhancing target-specific accumulation while minimizing off-target uptake. We designed a light-triggered system that permits spatiotemporal regulation of aptamer activity in vitro and in vivo. Cell binding by the aptamer was prevented by hybridizing the aptamer to a photo-labile complementary oligonucleotide. Upon irradiation at the tumor site, the aptamer was liberated, leading to prolonged intratumoral retention. The relative distribution of the aptamer to the liver and kidney was also significantly decreased, compared to that of the free aptamer. PMID:25404344

  8. EDITORIAL: Nanotechnology in vivo Nanotechnology in vivo

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-04-01

    -imaging labels [4]. A surface hydroxyl group renders silicon quantum dots soluble in water and the photoluminescence can be made stable with oxygen-passivation. In addition, researchers in Japan have demonstrated how the initially modest yield in the preparation of silicon quantum dots can be improved to tens of milligrams per batch, thus further promoting their application in bio-imaging [5]. In the search for non-toxic quantum dots, researchers at the Amrita Centre for Nanoscience in India have prepared heavy metal-free quantum dot bio-probes based on single phase ZnS [6]. The quantum dots are selectively doped with metals, transition metals and halides to provide tuneable luminescence properties, and they are surface conjugated with folic acid for cancer targeting. The quantum dots were demonstrated to be water-soluble, non-toxic in normal and cancer cell lines, and have bright, tuneable luminescence. So far most of the quantum dots developed for bio-imaging have had excitation and emission wavelengths in the visible spectrum, which is highly absorbed by tissue. This limits imaging with these quantum dots to superficial tissues. This week, researchers in China and the US reported work developing functionalized dots for in vivo tumour vasculature in the infrared part of the spectrum [7]. In addition the quantum dots were functionalised with glycine-aspartic acid (RGD) peptides, which target the vasculature of almost all types of growing tumours, unlike antibody- or aptamer-mediated targeting strategies that are specific to a particular cancer type. In this issue, researchers in China and the US demonstrate a novel type of contrast agent for ultrasonic tumour imaging [8]. Contrast-enhanced ultrasonic tumour imaging extends the diagnostic and imaging capabilities of traditional techniques. The use of nanoparticles as ultrasound contrast agents exploits the presence of open pores in the range of 380 to 780 nm in tumour blood vessels, which enhance the permeability and retention

  9. Sputtered protective coatings for die casting dies

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Nieh, C. Y.; Wallace, J. F.

    1981-01-01

    This investigation determined whether selected ion beam sputtered coatings on H-13 die steel would have the potential of improving the thermal fatigue behavior of the steel used as a die in aluminum die casting. The coatings were selected to test candidate insulators and metals capable of providing protection of the die surface. The studies indicate that 1 micrometer thick W and Pt coatings reduced the thermal fatigue more than any other coating tested and are candidates to be used on a die surface to increase die life.

  10. EDITORIAL: Nanotechnology in vivo Nanotechnology in vivo

    NASA Astrophysics Data System (ADS)

    Demming, Anna

    2010-04-01

    -imaging labels [4]. A surface hydroxyl group renders silicon quantum dots soluble in water and the photoluminescence can be made stable with oxygen-passivation. In addition, researchers in Japan have demonstrated how the initially modest yield in the preparation of silicon quantum dots can be improved to tens of milligrams per batch, thus further promoting their application in bio-imaging [5]. In the search for non-toxic quantum dots, researchers at the Amrita Centre for Nanoscience in India have prepared heavy metal-free quantum dot bio-probes based on single phase ZnS [6]. The quantum dots are selectively doped with metals, transition metals and halides to provide tuneable luminescence properties, and they are surface conjugated with folic acid for cancer targeting. The quantum dots were demonstrated to be water-soluble, non-toxic in normal and cancer cell lines, and have bright, tuneable luminescence. So far most of the quantum dots developed for bio-imaging have had excitation and emission wavelengths in the visible spectrum, which is highly absorbed by tissue. This limits imaging with these quantum dots to superficial tissues. This week, researchers in China and the US reported work developing functionalized dots for in vivo tumour vasculature in the infrared part of the spectrum [7]. In addition the quantum dots were functionalised with glycine-aspartic acid (RGD) peptides, which target the vasculature of almost all types of growing tumours, unlike antibody- or aptamer-mediated targeting strategies that are specific to a particular cancer type. In this issue, researchers in China and the US demonstrate a novel type of contrast agent for ultrasonic tumour imaging [8]. Contrast-enhanced ultrasonic tumour imaging extends the diagnostic and imaging capabilities of traditional techniques. The use of nanoparticles as ultrasound contrast agents exploits the presence of open pores in the range of 380 to 780 nm in tumour blood vessels, which enhance the permeability and retention

  11. Theory in vivo.

    PubMed

    Duncan, D

    1993-02-01

    Due to a formerly held assumption that psychoanalytic theories operate exclusively in the positivistic manner associated with the natural sciences, current thinking on how they operate specifically or in their own terms is addressing a long-neglected task. In this paper it is suggested that inherent and acquired modes of theorizing interplay when an analyst is working; and that a dialogue involving these two modes which began in Freud's inner life has evolved into our communal conceptual discourse. A series of situationally connected interchanges with a female analysand, over a two-week period, is presented. An attempt is made to demonstrate some theorizing, not 'in vitro'--'in the test-tube' of abstraction, but where most use and discovery of theory happens, 'in vivo'--within the living experience of therapeutic analysis. PMID:8454402

  12. In vivo dosimetry for IMRT

    SciTech Connect

    Vial, Philip

    2011-05-05

    In vivo dosimetry has a well established role in the quality assurance of 2D radiotherapy and 3D conformal radiotherapy. The role of in vivo dosimetry for IMRT is not as well established. IMRT introduces a range of technical issues that complicate in vivo dosimetry. The first decade or so of IMRT implementation has largely relied upon pre-treatment phantom based dose verification. During that time, several new devices and techniques for in vivo dosimetry have emerged with the promise of providing the ultimate form of IMRT dose verification. Solid state dosimeters continue to dominate the field of in vivo dosimetry in the IMRT era. In this report we review the literature on in vivo dosimetry for IMRT, with an emphasis on clinical evidence for different detector types. We describe the pros and cons of different detectors and techniques in the IMRT setting and the roles that they are likely to play in the future.

  13. In vivo dosimetry for IMRT

    NASA Astrophysics Data System (ADS)

    Vial, Philip

    2011-05-01

    In vivo dosimetry has a well established role in the quality assurance of 2D radiotherapy and 3D conformal radiotherapy. The role of in vivo dosimetry for IMRT is not as well established. IMRT introduces a range of technical issues that complicate in vivo dosimetry. The first decade or so of IMRT implementation has largely relied upon pre-treatment phantom based dose verification. During that time, several new devices and techniques for in vivo dosimetry have emerged with the promise of providing the ultimate form of IMRT dose verification. Solid state dosimeters continue to dominate the field of in vivo dosimetry in the IMRT era. In this report we review the literature on in vivo dosimetry for IMRT, with an emphasis on clinical evidence for different detector types. We describe the pros and cons of different detectors and techniques in the IMRT setting and the roles that they are likely to play in the future.

  14. Imaging schistosomes in vivo

    PubMed Central

    Krautz-Peterson, Greice; Ndegwa, David; Vasquez, Kristine; Korideck, Houari; Zhang, Jun; Peterson, Jeffrey D.; Skelly, Patrick J.

    2009-01-01

    Schistosomes are intravascular, parasitic helminths that cause a chronic, often debilitating disease afflicting over 200 million people in over 70 countries. Here we describe novel imaging methods that, for the first time, permit visualization of live schistosomes within their living hosts. The technology centers on fluorescent agent uptake and activation in the parasite’s gut, and subsequent detection and signal quantitation using fluorescence molecular tomography (FMT). There is a strong positive correlation between the signal detected and parasite number. Schistosoma mansoni parasites of both sexes recovered from infected experimental animals exhibit vivid fluorescence throughout their intestines. Likewise, the remaining important human schistosome parasites, S. japonicum and S. hematobium, also exhibit gut fluorescence when recovered from infected animals. Imaging has been used to efficiently document the decline in parasite numbers in infected mice treated with the antischistosome drug praziquantel. This technology will provide a unique opportunity both to help rapidly identify much-needed, novel antischistosome therapies and to gain direct visual insight into the intravascular lives of the major schistosome parasites of humans.—Krautz-Peterson, G., Ndegwa, D., Vasquez, K., Korideck, H., Zhang, J., Peterson, J. D., Skelly, P. J. Imaging schistosomes in vivo. PMID:19346298

  15. Displaced capillary dies

    DOEpatents

    Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas

    1984-01-01

    An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

  16. Displaced capillary dies

    DOEpatents

    Kalejs, Juris P.; Chalmers, Bruce; Surek, Thomas

    1982-01-01

    An asymmetrical shaped capillary die made exclusively of graphite is used to grow silicon ribbon which is capable of being made into solar cells that are more efficient than cells produced from ribbon made using a symmetrically shaped die.

  17. Packaged die heater

    SciTech Connect

    Spielberger, Richard; Ohme, Bruce Walker; Jensen, Ronald J.

    2011-06-21

    A heater for heating packaged die for burn-in and heat testing is described. The heater may be a ceramic-type heater with a metal filament. The heater may be incorporated into the integrated circuit package as an additional ceramic layer of the package, or may be an external heater placed in contact with the package to heat the die. Many different types of integrated circuit packages may be accommodated. The method provides increased energy efficiency for heating the die while reducing temperature stresses on testing equipment. The method allows the use of multiple heaters to heat die to different temperatures. Faulty die may be heated to weaken die attach material to facilitate removal of the die. The heater filament or a separate temperature thermistor located in the package may be used to accurately measure die temperature.

  18. HIGH PRESSURE DIES

    DOEpatents

    Wilson, W.B.

    1960-05-31

    A press was invented for subjecting specimens of bismuth, urania, yttria, or thoria to high pressures and temperatures. The press comprises die parts enclosing a space in which is placed an electric heater thermally insulated from the die parts so as not to damage them by heat. The die parts comprise two opposed inner frustoconical parts and an outer part having a double frustoconical recess receiving the inner parts. The die space decreases in size as the inner die parts move toward one another against the outer part and the inner parts, though very hard, do not fracture because of the mode of support provided by the outer part.

  19. [Harmony in dying].

    PubMed

    Meyer, H

    1990-02-13

    Dying and death have scarcely before our time preoccupied so many. Some even seem to thrive from thanatology. Do we physicians however consecrate patience and time to the dying of our next or our patients? Did we learn in medical school or with our patients to assist a dying person? Did we search for answers to death and dying by asking philosophers, physicians or musicians? Can we follow their reasoning in profit for our patients or for ourselves? Harmony in death can possibly be found in a harmonious life in our splendid and humane profession. Modest personal experience enriched by reflections tries imperfectly to bring harmony as hope to our dying.

  20. Die singulation method

    DOEpatents

    Swiler, Thomas P [Albuquerque, NM; Garcia, Ernest J [Albuquerque, NM; Francis, Kathryn M [Rio Rancho, NM

    2014-01-07

    A method is disclosed for singulating die from a semiconductor substrate (e.g. a semiconductor-on-insulator substrate or a bulk silicon substrate) containing an oxide layer (e.g. silicon dioxide or a silicate glass) and one or more semiconductor layers (e.g. monocrystalline or polycrystalline silicon) located above the oxide layer. The method etches trenches through the substrate and through each semiconductor layer about the die being singulated, with the trenches being offset from each other around at least a part of the die so that the oxide layer between the trenches holds the substrate and die together. The trenches can be anisotropically etched using a Deep Reactive Ion Etching (DRIE) process. After the trenches are etched, the oxide layer between the trenches can be etched away with a HF etchant to singulate the die. A release fixture can be located near one side of the substrate to receive the singulated die.

  1. Die singulation method

    DOEpatents

    Swiler, Thomas P.; Garcia, Ernest J.; Francis, Kathryn M.

    2013-06-11

    A method is disclosed for singulating die from a semiconductor substrate (e.g. a semiconductor-on-insulator substrate or a bulk silicon substrate) containing an oxide layer (e.g. silicon dioxide or a silicate glass) and one or more semiconductor layers (e.g. monocrystalline or polycrystalline silicon) located above the oxide layer. The method etches trenches through the substrate and through each semiconductor layer about the die being singulated, with the trenches being offset from each other around at least a part of the die so that the oxide layer between the trenches holds the substrate and die together. The trenches can be anisotropically etched using a Deep Reactive Ion Etching (DRIE) process. After the trenches are etched, the oxide layer between the trenches can be etched away with an HF etchant to singulate the die. A release fixture can be located near one side of the substrate to receive the singulated die.

  2. Extrusion die and method

    DOEpatents

    Lipp, G. Daniel

    1994-04-26

    A method and die apparatus for manufacturing a honeycomb body of rhombic cell cross-section by extrusion through an extrusion die of triangular cell discharge slot configuration, the die incorporating feedholes at selected slot intersections only, such that slot segments communicating directly with the feedholes discharge web material and slot segments not so connected do not discharge web material, whereby a rhombic cell cross-section in the extruded body is provided.

  3. The Ambiguous Dying Syndrome

    ERIC Educational Resources Information Center

    Bern-Klug, Mercedes

    2004-01-01

    More than one-half of the 2.4 million deaths that will occur in the United States in 2004 will be immediately preceded by a time in which the likelihood of dying can best be described as "ambiguous." Many people die without ever being considered "dying" or "at the end of life." These people may miss out on the opportunity to close important…

  4. Sputtered protective coatings for die casting dies

    NASA Technical Reports Server (NTRS)

    Mirtich, M. J.; Nieh, C.-Y.; Wallace, J. F.

    1981-01-01

    Three experimental research designs investigating candidate materials and processes involved in protective die surface coating procedures by sputter deposition, using ion beam technologies, are discussed. Various pre-test results show that none of the coatings remained completely intact for 15,000 test cycles. The longest lifetime was observed for coatings such as tungsten, platinum, and molybdenum which reduced thermal fatigue, but exhibited oxidation and suppressed crack initiation only as long as the coating did not fracture. Final test results confirmed earlier findings and coatings with Pt and W proved to be the candidate materials to be used on a die surface to increase die life. In the W-coated specimens, which remained intact on the surface after thermal fatigue testing, no oxidation was found under the coating, although a few cracks formed on the surface where the coating broke down. Further research is planned.

  5. Is Dying Young Worse than Dying Old?

    ERIC Educational Resources Information Center

    Jecker, Nancy S.; Schneiderman, Lawrence J.

    1994-01-01

    Notes that, in contemporary Western society, people feel death of small child is greater injustice than death of older adult and experience correspondingly greater sorrow, anger, regret, or bitterness when very young person dies. Contrasts these attitudes with those of ancient Greece and shows relevance that different attitudes toward death have…

  6. Micromechanical die attachment surcharge

    DOEpatents

    Filter, William F.; Hohimer, John P.

    2002-01-01

    An attachment structure is disclosed for attaching a die to a supporting substrate without the use of adhesives or solder. The attachment structure, which can be formed by micromachining, functions purely mechanically in utilizing a plurality of shaped pillars (e.g. round, square or polygonal and solid, hollow or slotted) that are formed on one of the die or supporting substrate and which can be urged into contact with various types of mating structures including other pillars, a deformable layer or a plurality of receptacles that are formed on the other of the die or supporting substrate, thereby forming a friction bond that holds the die to the supporting substrate. The attachment structure can further include an alignment structure for precise positioning of the die and supporting substrate to facilitate mounting the die to the supporting substrate. The attachment structure has applications for mounting semiconductor die containing a microelectromechanical (MEM) device, a microsensor or an integrated circuit (IC), and can be used to form a multichip module. The attachment structure is particularly useful for mounting die containing released MEM devices since these devices are fragile and can otherwise be damaged or degraded by adhesive or solder mounting.

  7. Extrusion die and method

    DOEpatents

    Lipp, G. Daniel

    1994-05-03

    A method and die apparatus for manufacturing a honeycomb body of triangular cell cross-section and high cell density, the die having a combination of (i) feedholes feeding slot intersections and (ii) feedholes feeding slot segments not supplied from slot intersections, whereby a reduction in feedhole count is achieved while still retaining good extrusion efficiency and extrudate uniformity.

  8. Terahertz pulsed imaging in vivo

    NASA Astrophysics Data System (ADS)

    Pickwell-MacPherson, E.

    2011-03-01

    Terahertz (1012 Hz) pulsed imaging is a totally non-destructive and non-ionising imaging modality and thus potential applications in medicine are being investigated. In this paper we present results using our hand-held terahertz probe that has been designed for in vivo use. In particular, we use the terahertz probe to perform reflection geometry in vivo measurements of human skin. The hand-held terahertz probe gives more flexibility than a typical flat-bed imaging system, but it also results in noisier data and requires existing processing methods to be improved. We describe the requirements and limitations of system geometry, data acquisition rate, image resolution and penetration depth and explain how various factors are dependent on each other. We show how some of the physical limitations can be overcome using novel data processing methods.

  9. In vivo imaging of sulfotransferases

    DOEpatents

    Barrio, Jorge R; Kepe, Vladimir; Small, Gary W; Satyamurthy, Nagichettiar

    2013-02-12

    Radiolabeled tracers for sulfotransferases (SULTs), their synthesis, and their use are provided. Included are substituted phenols, naphthols, coumarins, and flavones radiolabeled with .sup.18F, .sup.123I, .sup.124I, .sup.125I, or .sup.11C. Also provided are in vivo techniques for using these and other tracers as analytical and diagnostic tools to study sulfotransferase distribution and activity, in health and disease, and to evaluate therapeutic interventions.

  10. Bond failure patterns in vivo.

    PubMed

    Linklater, Rognvald A; Gordon, Peter H

    2003-05-01

    The aim of this study was to identify the presence and pattern of differences in bond failure between tooth types in vivo when bonding orthodontic brackets with the no-mix orthodontic composite adhesive Right-On. In vivo bond failure for a single operator was recorded for 108 consecutive patients undergoing fixed-appliance orthodontic treatment. The bond failure data were analyzed by survival analysis. Time to first failure or censorship was recorded for each bonded attachment. Overall failure in the sample matched previous clinical studies but conflicted with previous ex vivo bond strength data. Mandibular and posterior teeth had significantly higher rates of failure than did maxillary and anterior teeth. The type of attachment used had a significant effect on bond survival. The results of this study confirm that in vivo bond survival is not uniform for all teeth. Comparisons between the findings of this study and those of a previous ex vivo study by the same authors failed to validate ex vivo bond strength testing as clinically relevant.

  11. Effect of Varying Layers of Two Die Spacers on Precementation Space of Full Coverage Restorations.

    PubMed

    Mule, Shivkumar A; Dange, Shankar P; Khalikar, Arun N; Vaidya, Smita P

    2014-12-01

    The purpose of this study was to evaluate and compare the effect of varying layers of two commercially available die spacers on pre-cementation space of full coverage restorations in vitro and in vivo. Seven dies were prepared for each of 15 subjects. On three dies 1, 2, 3 layers of Pico-fit and on other three dies 1, 2, 3 layers of Yeti die spacers applied, wax pattern fabricated, invested and cast. Metal copings seated in vitro on die without die spacer and on prepared tooth of respective subject with fit-checker. Thickness of fit checker was measured using micrometer at mid-axial, mid-occlusal and near finish line locations that provided pre-cementation space. Result of ANOVA tests suggested significant difference among groups with varying layers. There was no significant difference between pre-cementation space achieved with Pico-fit and Yeti die spacers. The r values suggested positive correlation between the respective pair of in vivo and in vitro groups. (1) There was significant difference between pre-cementation space at mid-axial and mid-occlusal sites achieved with 1, 2 and 3 layers of die spacers except between 1 and 2 layers and 1 and 3 layers at mid-occlusal site. (2) Pre-cementation space achieved with Pico-fit and Yeti die spacers did not differ significantly for same location, layers and in vitro and in vivo. (3) Pre-cementation space achieved in vitro was analogous to pre-cementation space achieved in vivo for respective location, layers and die spacer.

  12. When Somebody Dies

    MedlinePlus

    ... alguien muere All living things — including bugs and fish and people — die. It's difficult, even for grownups, ... kind of death for families and friends to deal with because it happens so fast. There is ...

  13. Is dying young worse than dying old?

    PubMed

    Jecker, N S; Schneiderman, L J

    1994-02-01

    In contemporary Western society, people experience the deaths of older and younger persons differently. We are disposed to feel that the death of a small child is a greater injustice than the death of an older adult, and we experience correspondingly greater sorrow, anger, regret or bitterness when a very young person dies. This article examines these responses critically to determine whether they are backed by ethical considerations that reason can discern and defend. We contrast contemporary attitudes with those of ancient Greece and show the relevance that different attitudes toward death have for health care decision making.

  14. In vivo correlation mapping microscopy

    NASA Astrophysics Data System (ADS)

    McGrath, James; Alexandrov, Sergey; Owens, Peter; Subhash, Hrebesh; Leahy, Martin

    2016-04-01

    To facilitate regular assessment of the microcirculation in vivo, noninvasive imaging techniques such as nailfold capillaroscopy are required in clinics. Recently, a correlation mapping technique has been applied to optical coherence tomography (OCT), which extends the capabilities of OCT to microcirculation morphology imaging. This technique, known as correlation mapping optical coherence tomography, has been shown to extract parameters, such as capillary density and vessel diameter, and key clinical markers associated with early changes in microvascular diseases. However, OCT has limited spatial resolution in both the transverse and depth directions. Here, we extend this correlation mapping technique to other microscopy modalities, including confocal microscopy, and take advantage of the higher spatial resolution offered by these modalities. The technique is achieved as a processing step on microscopy images and does not require any modification to the microscope hardware. Results are presented which show that this correlation mapping microscopy technique can extend the capabilities of conventional microscopy to enable mapping of vascular networks in vivo with high spatial resolution in both the transverse and depth directions.

  15. Live and let die

    PubMed Central

    Milsom, Michael D.; Williams, David A.

    2007-01-01

    Gene transfer into hematopoietic stem cells (HSC) provides a potential means of correcting monogenic defects and altering drug sensitivity of normal bone marrow to cytotoxic agents. These applications have significant therapeutic potential but the translation of successful murine studies into human therapies has been hindered by low gene transfer in large animals (including humans), and recent serious side effects in a human immunodeficiency trial related to insertional mutagenesis. The latter trial, along with other subsequent trials, while bringing into focus the potential risks of integrating vector systems, also clearly demonstrate the potential usefulness of in vivo selection as it relates to inefficient stem cell transduction. Developing from initial studies by our group and other investigators in which drug resistance was utilized to demonstrate the feasibility of using gene transfer to effect protection from myelotoxicity of chemotherapeutic agents, expression of mutant forms of O6-methyguanine-DNA-methytransferase (MGMT) coupled with the simultaneous use of pharmacologic inhibitors and chemotherapeutic agents has been shown to provide a powerful method to select HSC in vivo. While stem and progenitor cell protection and resulting selection in vivo has potential applications for the treatment of selected cancers (allowing dose escalation) andor correction of monogenic disease (allowing an iatrogenic survival advantage of transduced cells in vivo), such an in vivo selection may have untoward effects on stem cell behavior. These deleterious effects may include stem cell exhaustion; lineage skewing; accumulation of genotoxic lesions; and clonal dominance driven towards a pro-leukemic phenotype. Knowledge of the likelihood of such deleterious events occurring as well as their potential implications will be critical to future clinical applications and may also enhance our understanding of both normal stem cell behavior and the evolution of hematopoietic

  16. In vivo dosimetry in brachytherapy

    SciTech Connect

    Tanderup, Kari; Beddar, Sam; Andersen, Claus E.; Kertzscher, Gustavo; Cygler, Joanna E.

    2013-07-15

    In vivo dosimetry (IVD) has been used in brachytherapy (BT) for decades with a number of different detectors and measurement technologies. However, IVD in BT has been subject to certain difficulties and complexities, in particular due to challenges of the high-gradient BT dose distribution and the large range of dose and dose rate. Due to these challenges, the sensitivity and specificity toward error detection has been limited, and IVD has mainly been restricted to detection of gross errors. Given these factors, routine use of IVD is currently limited in many departments. Although the impact of potential errors may be detrimental since treatments are typically administered in large fractions and with high-gradient-dose-distributions, BT is usually delivered without independent verification of the treatment delivery. This Vision 20/20 paper encourages improvements within BT safety by developments of IVD into an effective method of independent treatment verification.

  17. Measuring Vascular Permeability In Vivo.

    PubMed

    Meijer, Eelco F J; Baish, James W; Padera, Timothy P; Fukumura, Dai

    2016-01-01

    Over the past decades, in vivo vascular permeability measurements have provided significant insight into vascular functions in physiological and pathophysiological conditions such as the response to pro- and anti-angiogenic signaling, abnormality of tumor vasculature and its normalization, and delivery and efficacy of therapeutic agents. Different approaches for vascular permeability measurements have been established. Here, we describe and discuss a conventional 2D imaging method to measure vascular permeability, which was originally documented by Gerlowski and Jain in 1986 (Microvasc Res 31:288-305, 1986) and further developed by Yuan et al. in the early 1990s (Microvasc Res 45:269-289, 1993; Cancer Res 54:352-3356, 1994), and our recently developed 3D imaging method, which advances the approach originally described by Brown et al. in 2001 (Nat Med 7:864-868, 2001). PMID:27581015

  18. [Towards optical in vivo electrophysiology].

    PubMed

    Lambot, Laurie; Gall, David

    Optical imaging of voltage indicators is a promising approach for detecting the activity of neuronal circuits with high spatial and temporal resolution. In this context, genetically encoded voltage indicators, combining genetic targeting and optical readout of transmembrane voltage, represent a technological breaktrough that will without doubt have a major impact in neuroscience. However, so far the existing genetically encoded voltage indicators lacked the capabilities to detect individual action potentials and fast spike trains in live animals. Here, we present a novel indicator allowing high-fidelity imaging of individual spikes and dentritic voltage dynamics in vivo. Used in combination with optogenetics, which allows to manipulate neuronal activity, this opens the possibility of an all-optical electrophysiology. PMID:27615186

  19. In Vivo EPR For Dosimetry

    PubMed Central

    Swartz, Harold M.; Burke, Greg; Coey, M.; Demidenko, Eugene; Dong, Ruhong; Grinberg, Oleg; Hilton, James; Iwasaki, Akinori; Lesniewski, Piotr; Kmiec, Maciej; Lo, Kai-Ming; Nicolalde, R. Javier; Ruuge, Andres; Sakata, Yasuko; Sucheta, Artur; Walczak, Tadeusz; Williams, Benjamin B.; Mitchell, Chad; Romanyukha, Alex; Schauer, David A.

    2007-01-01

    As a result of terrorism, accident, or war, populations potentially can be exposed to doses of ionizing radiation that could cause direct clinical effects within days or weeks. There is a critical need to determine the magnitude of the exposure to individuals so that those with significant risk have appropriate procedures initiated immediately, while those without a significant probability of acute effects can be reassured and removed from the need for further consideration in the medical/emergency system. In many of the plausible scenarios there is an urgent need to make the determination very soon after the event and while the subject is still present. In vivo EPR measurements of radiation-induced changes in the enamel of teeth is a method, perhaps the only such method, which can differentiate among doses sufficiently for classifying individuals into categories for treatment with sufficient accuracy to facilitate decisions on medical treatment. In its current state, the in vivo EPR dosimeter can provide estimates of absorbed dose with an error approximately ± 50 cGy over the range of interest for acute biological effects of radiation, assuming repeated measurements of the tooth in the mouth of the subject. The time required for acquisition, the lower limit, and the precision are expected to improve, with improvements in the resonator and the algorithm for acquiring and calculating the dose. The magnet system that is currently used, while potentially deployable, is somewhat large and heavy, requiring that it be mounted on a small truck or trailer. Several smaller magnets, including an intraoral magnet are under development, which would extend the ease of use of this technique. PMID:18591988

  20. Experiences of the dying.

    PubMed

    Schoenbeck, Susan L

    2011-01-01

    It is often a mystery to us how we have come to know and believe in certain things. Beliefs are like guests who come up to a door. They come in only if the host opens it and invites them in. Otherwise they are turned away, unable to enter. LPNs/LVNs are invited to reflect on their experiences and expand their knowledge and beliefs. There is growing recognition that bedside talks of the dying, spirit travel and near-death events are real events for the people who experience them. LPNs/ LVNs are encouraged to expand their knowledge and beliefs about dying.

  1. [Human dying has changed].

    PubMed

    Llano Escobar, A

    1990-01-01

    In the modern era, the act of dying, at least in the West, presents a series of new characteristics resulting from scientific and technological progress and social changes. More and more frequently, humans die in the strange surroundings of medical establishments without the support of their loved ones and without the opportunity of taking part in decisions related to their own deaths. In the light of the serious personal and social problems caused by this transformation of human death, bioethics emerges as an attempt to uncover options that are more humane.

  2. Die andere Revolution

    NASA Astrophysics Data System (ADS)

    Kippenhahn, Rudolf

    2005-05-01

    War Kopernikus der größte Revolutionär des naturwissenschaftlichen Weltbildes? Seine Erkenntnisse waren der Beginn eines jahrhundertelangen Denkprozesses, welcher zur Einsicht führte, dass im Weltall die gleichen physikalischen Gesetze gelten wie auf der Erde.

  3. Die Kosmologie der Griechen.

    NASA Astrophysics Data System (ADS)

    Mittelstraß, J.

    Contents: 1. Mythische Eier. 2. Thales-Welten. 3. "Alles ist voller Götter". 4. Griechische Astronomie. 5. "Rettung der Phänomene". 6. Aristotelische Kosmololgie. 7. Aristoteles-Welt und Platon-Welt. 8. Noch einmal: die Göttlichkeit der Welt. 9. Griechischer Idealismus.

  4. Navigating "Assisted Dying".

    PubMed

    Schipper, Harvey

    2016-02-01

    Carter is a bellwether decision, an adjudication on a narrow point of law whose implications are vast across society, and whose impact may not be realized for years. Coupled with Quebec's Act Respecting End-of-life Care it has sharply changed the legal landscape with respect to actively ending a person's life. "Medically assisted dying" will be permitted under circumstances, and through processes, which have yet to be operationally defined. This decision carries with it moral assumptions, which mean that it will be difficult to reach a unifying consensus. For some, the decision and Act reflect a modern acknowledgement of individual autonomy. For others, allowing such acts is morally unspeakable. Having opened the Pandora's Box, the question becomes one of navigating a tolerable societal path. I believe it is possible to achieve a workable solution based on the core principle that "medically assisted dying" should be a very rarely employed last option, subject to transparent ongoing review, specifically as to why it was deemed necessary. My analysis is based on 1. The societal conditions in which have fostered demand for "assisted dying", 2. Actions in other jurisdictions, 3. Carter and Quebec Bill 52, 4. Political considerations, 5. Current medical practice. Leading to a series of recommendations regarding. 1. Legislation and regulation, 2. The role of professional regulatory agencies, 3. Medical professions education and practice, 4. Public education, 5. Health care delivery and palliative care. Given the burden of public opinion, and the legal steps already taken, a process for assisted-dying is required. However, those legal and regulatory steps should only be considered a necessary and defensive first step in a two stage process. The larger goal, the second step, is to drive the improvement of care, and thus minimize assisted-dying. PMID:27169205

  5. Herausforderungen durch die deutsche Wiedervereinigung

    NASA Astrophysics Data System (ADS)

    Stäglin, Reiner

    Die Wiedervereinigung stellte auch die Statistik vor große Aufgaben. Die als Organ der staatlichen Planung staatsnah orientierte Statistik der DDR musste auf das zur Neutralität und wissenschaftlichen Unabhängigkeit verpflichtete System der Bundesrepublik umgestellt werden. Ebenso verlangten die Universitäten eine Neuorientierung. Die Deutsche Statistische Gesellschaft hat sich vor allem dreier Aufgaben mit großem Engagement, aber auch mit Bedachtsamkeit angenommen: Aufnahme und Integration der Statistiker aus den neuen Bundesländern in die Gesellschaft, Begleitung der Neuausrichtung des Faches Statistik an deren Hochschulen und Sicherung sowie Nutzung von Datenbeständen der ehemaligen DDR.

  6. Coffee induces autophagy in vivo.

    PubMed

    Pietrocola, Federico; Malik, Shoaib Ahmad; Mariño, Guillermo; Vacchelli, Erika; Senovilla, Laura; Chaba, Kariman; Niso-Santano, Mireia; Maiuri, Maria Chiara; Madeo, Frank; Kroemer, Guido

    2014-01-01

    Epidemiological studies and clinical trials revealed that chronic consumption coffee is associated with the inhibition of several metabolic diseases as well as reduction in overall and cause-specific mortality. We show that both natural and decaffeinated brands of coffee similarly rapidly trigger autophagy in mice. One to 4 h after coffee consumption, we observed an increase in autophagic flux in all investigated organs (liver, muscle, heart) in vivo, as indicated by the increased lipidation of LC3B and the reduction of the abundance of the autophagic substrate sequestosome 1 (p62/SQSTM1). These changes were accompanied by the inhibition of the enzymatic activity of mammalian target of rapamycin complex 1 (mTORC1), leading to the reduced phosphorylation of p70(S6K), as well as by the global deacetylation of cellular proteins detectable by immunoblot. Immunohistochemical analyses of transgenic mice expressing a GFP-LC3B fusion protein confirmed the coffee-induced relocation of LC3B to autophagosomes, as well as general protein deacetylation. Altogether, these results indicate that coffee triggers 2 phenomena that are also induced by nutrient depletion, namely a reduction of protein acetylation coupled to an increase in autophagy. We speculate that polyphenols contained in coffee promote health by stimulating autophagy.

  7. Coffee induces autophagy in vivo

    PubMed Central

    Pietrocola, Federico; Malik, Shoaib Ahmad; Mariño, Guillermo; Vacchelli, Erika; Senovilla, Laura; Chaba, Kariman; Niso-Santano, Mireia; Maiuri, Maria Chiara; Madeo, Frank; Kroemer, Guido

    2014-01-01

    Epidemiological studies and clinical trials revealed that chronic consumption coffee is associated with the inhibition of several metabolic diseases as well as reduction in overall and cause-specific mortality. We show that both natural and decaffeinated brands of coffee similarly rapidly trigger autophagy in mice. One to 4 h after coffee consumption, we observed an increase in autophagic flux in all investigated organs (liver, muscle, heart) in vivo, as indicated by the increased lipidation of LC3B and the reduction of the abundance of the autophagic substrate sequestosome 1 (p62/SQSTM1). These changes were accompanied by the inhibition of the enzymatic activity of mammalian target of rapamycin complex 1 (mTORC1), leading to the reduced phosphorylation of p70S6K, as well as by the global deacetylation of cellular proteins detectable by immunoblot. Immunohistochemical analyses of transgenic mice expressing a GFP–LC3B fusion protein confirmed the coffee-induced relocation of LC3B to autophagosomes, as well as general protein deacetylation. Altogether, these results indicate that coffee triggers 2 phenomena that are also induced by nutrient depletion, namely a reduction of protein acetylation coupled to an increase in autophagy. We speculate that polyphenols contained in coffee promote health by stimulating autophagy. PMID:24769862

  8. Coffee induces autophagy in vivo.

    PubMed

    Pietrocola, Federico; Malik, Shoaib Ahmad; Mariño, Guillermo; Vacchelli, Erika; Senovilla, Laura; Chaba, Kariman; Niso-Santano, Mireia; Maiuri, Maria Chiara; Madeo, Frank; Kroemer, Guido

    2014-01-01

    Epidemiological studies and clinical trials revealed that chronic consumption coffee is associated with the inhibition of several metabolic diseases as well as reduction in overall and cause-specific mortality. We show that both natural and decaffeinated brands of coffee similarly rapidly trigger autophagy in mice. One to 4 h after coffee consumption, we observed an increase in autophagic flux in all investigated organs (liver, muscle, heart) in vivo, as indicated by the increased lipidation of LC3B and the reduction of the abundance of the autophagic substrate sequestosome 1 (p62/SQSTM1). These changes were accompanied by the inhibition of the enzymatic activity of mammalian target of rapamycin complex 1 (mTORC1), leading to the reduced phosphorylation of p70(S6K), as well as by the global deacetylation of cellular proteins detectable by immunoblot. Immunohistochemical analyses of transgenic mice expressing a GFP-LC3B fusion protein confirmed the coffee-induced relocation of LC3B to autophagosomes, as well as general protein deacetylation. Altogether, these results indicate that coffee triggers 2 phenomena that are also induced by nutrient depletion, namely a reduction of protein acetylation coupled to an increase in autophagy. We speculate that polyphenols contained in coffee promote health by stimulating autophagy. PMID:24769862

  9. Red cell aging in vivo

    PubMed Central

    Ganzoni, A. M.; Oakes, R.; Hillman, R. S.

    1971-01-01

    Previous studies of red cell structure and metabolism during the aging process have relied upon in vitro techniques of cell separation into various age populations. Probably the most common approach is to isolate the older red cells with the assumption that they are more dense. This may lead to a number of inconsistencies in observations, and may certainly raise questions about possible cell changes secondary to manipulative procedures. For this reason, an experimental system was devised where a normal red cell population could be studied, while aging, in an in vivo environment. The initial red cell mass of a large number of inbred rats was transferred repeatedly into an ever smaller number of animals, making it possible to follow an aging population of red cells up to 48 days while preventing contamination with newly produced cells by suppression of erythropoiesis with transfusion-induced polycythemia. During this period, samples of progressively older red cells could be obtained for measurements of red cell constant. It was noted that the normal rat red cell undergoes both volume reduction and significant hemoglobin content loss with aging. In addition, the hemoglobin concentration within the cell demonstrated an early rise after a return to nearly normal values. These findings are noteworthy in that they help to explain the characteristics of life-spans of cohort labeled red cell populations in small animals, and provide a possible example of a cell's remodeling process within the spleen. PMID:5090053

  10. In vivo generator for radioimmunotherapy

    DOEpatents

    Mausner, Leonard F.; Srivastava, Suresh G.; Straub, Rita F.

    1988-01-01

    The present invention involves labeling monoclonal antibodies with intermediate half-life radionuclides which decay to much shorter half-life daughters with desirable high energy beta emissions. Since the daughter will be in equilibrium with the parent, it can exert an in-situ tumoricidal effect over a prolonged period in a localized fashion, essentially as an "in-vivo generator". This approach circumvents the inverse relationship between half-life and beta decay energy. Compartmental modeling was used to determine the relative distribution of dose from both parent and daughter nuclei in target and non-target tissues. Actual antibody biodistribution data have been used to fit realistic rate constants for a model containing tumor, blood, and non-tumor compartments. These rate constants were then used in a variety of simulations for two generator systems, Ba-128/Cs-128 (t.sub.1/2 =2.4d/3.6m) and Pd-112/Ag-112 (t.sub.1/2 =0.9d/192m). The results show that higher tumor/background dose ratios may be achievable by virtue of the rapid excretion of a chemically different daughter during the uptake and clearance phases. This modeling also quantitatively demonstrates the favorable impact on activity distribution of a faster monoclonal antibody tumor uptake, especially when the antibody is labeled with a radionuclide with a comparable half-life.

  11. In vivo generator for radioimmunotherapy

    DOEpatents

    Mausner, Leonard F.; Srivastava, Suresh G.; Straub, Rita F.

    1988-11-01

    The present invention involves labeling monoclonal antibodies with intermediate half-life radionuclides which decay to much shorter half-life daughters with desirable high energy beta emissions. Since the daughter will be in equilibrium with the parent, it can exert an in-situ tumoricidal effect over a prolonged period in a localized fashion, essentially as an "in-vivo generator". This approach circumvents the inverse relationship between half-life and beta decay energy. Compartmental modeling was used to determine the relative distribution of dose from both parent and daughter nuclei in target and non-target tissues. Actual antibody biodistribution data have been used to fit realistic rate constants for a model containing tumor, blood, and non-tumor compartments. These rate constants were then used in a variety of simulations for two generator systems, Ba-128/Cs-128 (t.sub.1/2 =2.4d/3.6m) and Pd-112/Ag-112 (t.sub.1/2 =0.9d/192m). The results show that higher tumor/background dose ratios may be achievable by virtue of the rapid excretion of a chemically different daughter during the uptake and clearance phases. This modeling also quantitatively demonstrates the favorable impact on activity distribution of a faster monoclonal antibody tumor uptake, especially when the antibody is labeled with a radionuclide with a comparable half-life.

  12. Modeling the Mechanical Performance of Die Casting Dies

    SciTech Connect

    R. Allen Miller

    2004-02-27

    The following report covers work performed at Ohio State on modeling the mechanical performance of dies. The focus of the project was development and particularly verification of finite element techniques used to model and predict displacements and stresses in die casting dies. The work entails a major case study performed with and industrial partner on a production die and laboratory experiments performed at Ohio State.

  13. Heated die facilitates tungsten forming

    NASA Technical Reports Server (NTRS)

    Chattin, J. H.; Haystrick, J. E.; Laughlin, J. C.; Leidy, R. A.

    1966-01-01

    Tungsten forming in a press brake employs a bottom die assembly with a heating manifold between two water-cooled die sections. The manifold has hydrogen-oxygen burners spaced along its length for even heat during forming.

  14. Absolute calibration in vivo measurement systems

    SciTech Connect

    Kruchten, D.A.; Hickman, D.P.

    1991-02-01

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs.

  15. Die kalte Zunge

    NASA Astrophysics Data System (ADS)

    Bartels, Sören; Müller, Rüdiger

    Gefühlte Temperaturen. Ist ein Null Grad Celsius kalter Metallstab eigentlich kälter als ein Holzstab mit der selben Temperatur? Rein physikalisch gesehen natürlich nicht, aber wenn wir beide Stäbe anfassen, kommt uns der Metallstab deutlich kälter vor. Und wer kennt nicht die Szene aus dem Film Dumm und Dümmer in der Harry mit seiner Zunge am Metallrahmen des Skilifts hängen bleibt.Würde das auch passieren, wenn man an einem eiskalten Stück Holz lecken würde? Wohl kaum, doch woran liegt das eigentlich? Unterschiedliche Materialien haben verschiedene Fähigkeiten, Wärme zu übertragen und zu leiten. So transportiert Metall die von der Zunge ausgehende Wärme sehr schnell weiter und verändert seine Temperatur kaum, während die Zunge abkühlt. Holz hingegen leitet Wärme fast gar nicht und daher wird der Teil, der von der Zunge berührt wird, aufgewärmt.

  16. Psychotherapy with Older Dying Persons.

    ERIC Educational Resources Information Center

    Dye, Carol J.

    Psychotherapy with older dying patients can lead to problems of countertransference for the clinician. Working with dying patients requires flexibility to adapt basic therapeutics to the institutional setting. Goals of psychotherapy must be reconceptualized for dying clients. The problems of countertransference arise because clinicians themselves…

  17. Psychotherapy with the dying patient.

    PubMed

    Schwartz, A M; Karasu, T B

    1977-01-01

    This paper develops and describes encounters with dying patients and their families and looks for consesus of patterns and responses of possible help in confronting this situation. It offers positive suggestions for those providing care for dying patients but also acknowledges that only an intellectual grasp of the situation is not sufficient qualification for caring for the dying.

  18. Tailoring vessel morphology in vivo

    NASA Astrophysics Data System (ADS)

    Gould, Daniel Joseph

    Tissue engineering is a rapidly growing field which seeks to provide alternatives to organ transplantation in order to address the increasing need for transplantable tissues. One huge hurdle in this effort is the provision of thick tissues; this hurdle exists because currently there is no way to provide prevascularized or rapidly vascularizable scaffolds. To design thick, vascularized tissues, scaffolds are needed that can induce vessels which are similar to the microvasculature found in normal tissues. Angiogenic biomaterials are being developed to provide useful scaffolds to address this problem. In this thesis angiogenic and cell signaling and adhesion factors were incorporated into a biomimetic poly(ethylene glycol) (PEG) hydrogel system. The composition of these hydrogels was precisely tuned to induce the formation of differing vessel morphology. To sensitively measure induced microvascular morphology and to compare it to native microvessels in several tissues, this thesis developed an image-based tool for quantification of scale invariant and classical measures of vessel morphology. The tool displayed great utility in the comparison of native vessels and remodeling vessels in normal tissues. To utilize this tool to tune the vessel response in vivo, Flk1::myr-mCherry fluorescently labeled mice were implanted with Platelet Derived Growth Factor-BB (PDGF-BB) and basic Fibroblast Growth Factor (FGF-2) containing PEG-based hydrogels in a modified mouse corneal angiogenesis assay. Resulting vessels were imaged with confocal microscopy, analyzed with the image based tool created in this thesis to compare morphological differences between treatment groups, and used to create a linear relationship between space filling parameters and dose of growth factor release. Morphological parameters of native mouse tissue vessels were then compared to the linear fit to calculate the dose of growth factors needed to induce vessels similar in morphology to native vessels

  19. Nitriding of Aluminum Extrusion Die: Effect of Die Geometry

    NASA Astrophysics Data System (ADS)

    Akhtar, S. S.; Arif, A. F. M.; Yilbas, B. S.

    2010-04-01

    Nitriding of complex-shaped extrusion dies may result in non-uniform nitride layers and hence a required hardness may not be achieved in some regions of the bearing area. The present study is carried out to assess the effect of extrusion die profile on the characteristics and growth behavior of nitride layers so that the critical die design feature can be identified to enhance the uniformity of the nitride layer. For this purpose, AISI H13 steel samples have been manufactured with profiles similar to those of hot extrusion dies. The samples were then gas nitrided under controlled nitriding potential. The uniformity and depth of nitride layers have been investigated in terms of compound layer and total nitride case depth for selected die features. The results of this study indicated the need to include the effect of profile on the nitride layer for the optimal die design with improved service life.

  20. Genetic targeting of chemical indicators in vivo.

    PubMed

    Yang, Guoying; de Castro Reis, Fernanda; Sundukova, Mayya; Pimpinella, Sofia; Asaro, Antonino; Castaldi, Laura; Batti, Laura; Bilbao, Daniel; Reymond, Luc; Johnsson, Kai; Heppenstall, Paul A

    2015-02-01

    Fluorescent protein reporters have become the mainstay for tracing cellular circuitry in vivo but are limited in their versatility. Here we generated Cre-dependent reporter mice expressing the Snap-tag to target synthetic indicators to cells. Snap-tag labeling worked efficiently and selectively in vivo, allowing for both the manipulation of behavior and monitoring of cellular fluorescence from the same reporter. PMID:25486061

  1. Why Optogenetics Needs in Vivo Neurochemistry.

    PubMed

    Parrot, Sandrine; Denoroy, Luc; Renaud, Bernard; Benetollo, Claire

    2015-07-15

    In neuroscience, the consequences of optogenetic manipulation are often studied using in vivo electrophysiology and by observing behavioral changes induced by light stimulation in genetically targeted rodents. In contrast, reports on the in vivo neurochemical effects of optogenetic stimulation are scarce despite the improving quality of analytical techniques available to monitor biochemical compounds involved in neurotransmission. This intriguing lack of neurochemical information suggests the existence of unknown or misunderstood factors hampering the expected rise of a novel specialty putatively be termed "neurochemical optogenetics".

  2. Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

    NASA Astrophysics Data System (ADS)

    Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

    2015-10-01

    Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

  3. Recent progress in in vivo ESR spectroscopy.

    PubMed

    Takeshita, Keizo; Ozawa, Toshihiko

    2004-09-01

    The generation of free radicals and redox status is related to various diseases and injuries that are related to radiation, aging, ischemia-reperfusion, and other oxidative factors. In vivo electron spin resonance (ESR) spectroscopy is noninvasive and detects durable free radicals in live animals. ESR spectrometers for in vivo measurements operate at a lower frequency (approximately 3.5 GHz, approximately 1 GHz, 700 MHz, and approximately 300 MHz) than usual (9-10 GHz). Several types of resonators have been designed to minimize the dielectric loss of electromagnetic waves caused by water in animal bodies. In vivo ESR spectroscopy and its imaging have been used to analyze radical generation, redox status, partial pressure of oxygen and other conditions in various disease and injury models related to oxidative stress with probes, such as nitroxyl radicals. Through these applications, the clarification of the mechanisms related to oxidative diseases (injuries) and the accumulation of basic data for radiological cancer therapy are now ongoing. In vivo ESR measurement is performed in about 10 laboratories worldwide, including ours. To introduce in vivo ESR spectroscopy to life scientists, this article reviews the recent progress of in vivo ESR spectroscopy in instrumentation and its application to the life sciences.

  4. Graphite/Thermoplastic-Pultrusion Die

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L.; Frye, Mark W.; Johnson, Gary S.; Stanfield, Clarence E.

    1990-01-01

    Attachment to extruder produces thermoplastic-impregnated graphite tape. Consists of profile die, fiber/resin collimator, and crosshead die body. Die designed to be attached to commercially available extrusion machine capable of extruding high-performance thermoplastics. Simple attachment to commercial extruder enables developers of composites to begin experimenting with large numbers of proprietary resins, fibers, and hybrid composite structures. With device, almost any possible fiber/resin combination fabricated.

  5. Die Milchstraße.

    NASA Astrophysics Data System (ADS)

    Henbest, N.; Couper, H.

    This book is a German translation, by M. Röser, from the English original "The guide to the Galaxy", published in 1994 (see Abstr. 61.003.065). Contents: 1. Die Entdeckung unserer Galaxis. 2. Die Lokale Gruppe. 3. Die Geographie der Galaxis. 4. Der Perseus-Arm. 5. Der Orion-Arm. 6. Unsere lokale Nachbarschaft: ein typischer Winkel der Galaxis. 7. Der Sagittarius-Arm: innerhalb der Sonnenumlaufbahn. 8. Das Zentrum der Galaxis.

  6. Where people die.

    PubMed

    Katz, B P; Zdeb, M S; Therriault, G D

    1979-01-01

    Death certificates for 1977 filed with the New York State Department of Health were studied to determine where people died. Data were examined by the location and cause of death and by the age, sex, race, and marital status of the decedent. Comparisons were made with a similar study in which U.S. data were used for 1958 events. Approximately 60 percent of all the 1977 deaths in upstate New York occurred in hospitals; only 27 percent occurred outside an institution. The location of death varied by all the factors studied. Within all age categories, males had a higher percentage of hospital deaths. In those age categories in which nursing home deaths comprised a significant proportion of total deaths, females had a higher percentage of such deaths than males. Differences in the location of death according to its cause reflect the nature of the cause of death, for example, whether it was of sudden onset or the result of chronic disease. Most people do not consider in advance where they might die. The idea that age, sex, and marital status, as well as the more obvious cause, all play a part in the location may seem surprising. Yet all these factors were found to be associated withe location of deaths in upstate New York, and there is no reason to believe that this association does not hold true for the entire nation. More research, however, needs to be done based on more years and other geographic artal stutus may be instructive as to the present state of health resources.

  7. In vivo studies of opiate receptors

    SciTech Connect

    Frost, J.J.; Dannals, R.F.; Duelfer, T.; Burns, H.D.; Ravert, H.T.; Langstroem, B.; Balasubramanian, V.; Wagner, H.N. Jr.

    1984-01-01

    To study opiate receptors noninvasively in vivo using positron emission tomography, techniques for preferentially labeling opiate receptors in vivo can be used. The rate at which receptor-bound ligand clears from the brain in vivo can be predicted by measuring the equilibrium dissociation constant (KD) at 37 degrees C in the presence of 100 mM sodium chloride and 100 microM guanyl-5'-imidodiphosphate, the drug distribution coefficient, and the molecular weight. A suitable ligand for labeling opiate receptors in vivo is diprenorphine, which binds to mu, delta, and kappa receptors with approximately equal affinity in vitro. However, in vivo diprenorphine may bind predominantly to one opiate receptor subtype, possibly the mu receptor. To predict the affinity for binding to the opiate receptor, a Hansch correlation was determined between the 50% inhibitory concentration for a series of halogen-substituted fentanyl analogs and electronic, lipophilic, and steric parameters. Radiochemical methods for the synthesis of carbon-11-labeled diprenorphine and lofentanil are presented.

  8. In Vivo Production of Entomopathogenic Nematodes.

    PubMed

    Shapiro-Ilan, David I; Morales-Ramos, Juan A; Rojas, M Guadalupe

    2016-01-01

    In nature, entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects. The nematodes are used widely as biopesticides for suppression of insect pests. More than a dozen entomopathogenic nematode species have been commercialized for use in biological control. Most nematodes intended for commercial application are produced in artificial media via solid or liquid fermentation. However, for laboratory research and small greenhouse or field trials, in vivo production of entomopathogenic nematodes is the common method of propagation. Additionally, small companies continue to produce nematodes using in vivo methods for application in niche markets. Advances in mechanization and alternative production routes (e.g., production geared toward application of nematodes in infected host cadavers) can improve efficiency and economy of scale. The objective of this chapter is to describe basic and advanced procedures for in vivo production of entomopathogenic nematodes. PMID:27565497

  9. In vivo cell tracking with bioluminescence imaging.

    PubMed

    Kim, Jung Eun; Kalimuthu, Senthilkumar; Ahn, Byeong-Cheol

    2015-03-01

    Molecular imaging is a fast growing biomedical research that allows the visual representation, characterization and quantification of biological processes at the cellular and subcellular levels within intact living organisms. In vivo tracking of cells is an indispensable technology for development and optimization of cell therapy for replacement or renewal of damaged or diseased tissue using transplanted cells, often autologous cells. With outstanding advantages of bioluminescence imaging, the imaging approach is most commonly applied for in vivo monitoring of transplanted stem cells or immune cells in order to assess viability of administered cells with therapeutic efficacy in preclinical small animal models. In this review, a general overview of bioluminescence is provided and recent updates of in vivo cell tracking using the bioluminescence signal are discussed.

  10. In Vivo Depletion of T Lymphocytes.

    PubMed

    Laky, Karen; Kruisbeek, Ada M

    2016-01-01

    In vivo depletion of T lymphocytes is a means of studying the role of specific T cell populations during defined phases of in vivo immune responses. In this unit, a protocol is provided for injecting monoclonal antibodies (mAbs) into wild-type adult mice. Depletion of the appropriate subset of cells is verified by flow cytometry analysis of lymph node and spleen cell suspensions in pilot experiments. Once conditions have been established, depleted mice can be used to study the impact of T cell subsets on a variety of in vivo immune responses. The depleted condition may be maintained by repeated injections of the monoclonal antibody, or reversed by normal thymopoiesis following discontinuation of antibody administration. PMID:27038463

  11. Grueneisen relaxation photoacoustic microscopy in vivo

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Shi, Junhui; Hai, Pengfei; Zhou, Yong; Wang, Lihong V.

    2016-06-01

    Grueneisen relaxation photoacoustic microscopy (GR-PAM) can achieve optically defined axial resolution, but it has been limited to ex vivo demonstrations so far. Here, we present the first in vivo image of a mouse brain acquired with GR-PAM. To induce the GR effect, an intensity-modulated continuous-wave laser was employed to heat absorbing objects. In phantom experiments, an axial resolution of 12.5 μm was achieved, which is sixfold better than the value achieved by conventional optical-resolution PAM. This axial-resolution improvement was further demonstrated by imaging a mouse brain in vivo, where significantly narrower axial profiles of blood vessels were observed. The in vivo demonstration of GR-PAM shows the potential of this modality for label-free and high-resolution anatomical and functional imaging of biological tissues.

  12. Outer Hair Cell Electromotility in vivo

    NASA Astrophysics Data System (ADS)

    Ramamoorthy, Sripriya; Nuttall, Alfred L.

    2011-11-01

    The effectiveness of outer hair cell (OHC) electro-motility in vivo has been challenged by the expected low-pass filtering of the transmembrane potential due to the cell's own capacitance. The OHC electromotility is characterized here by an electromechanical ratio defined as the ratio of the OHC contraction to the transmembrane potential. This ratio has been measured in isolated cells to be approximately 26 nm/mV. We estimate the OHC electromechanical ratio in vivo from the recently measured displacements of the reticular lamina and the basilar membrane near the 19 kHz characteristic frequency in the basal region of guinea pig cochlea. Our analysis strongly suggests OHC electromotility process is effective for cochlear amplification in vivo at least around the characteristic frequency of the basal location in spite of the low-pass filtering.

  13. Two Piece Compaction Die Design

    SciTech Connect

    Coffey, Ethan N

    2010-03-01

    Compaction dies used to create europium oxide and tantalum control plates were modeled using ANSYS 11.0. Two-piece designs were considered in order to make the dies easier to assemble than the five-piece dies that were previously used. The two areas of concern were the stresses at the interior corner of the die cavity and the distortion of the cavity wall due to the interference fit between the two pieces and the pressure exerted on the die during the compaction process. A successful die design would have stresses less than the yield stress of the material and a maximum wall distortion on the order of 0.0001 in. Design factors that were investigated include the inner corner radius, the value of the interference fit, the compaction force, the size of the cavity, and the outer radius and geometry of the outer ring. The results show that for the europium oxide die, a 0.01 in. diameter wire can be used to create the cavity, leading to a 0.0055 in. radius corner, if the radial interference fit is 0.003 in. For the tantalum die, the same wire can be used with a radial interference fit of 0.001 in. Also, for the europium oxide die with a 0.003 in. interference fit, it is possible to use a wire with a diameter of 0.006 in. for the wire burning process. Adding a 10% safety factor to the compaction force tends to lead to conservative estimates of the stresses but not for the wall distortion. However, when the 10% safety factor is removed, the wall distortion is not affected enough to discard the design. Finally, regarding the europium oxide die, when the cavity walls are increased by 0.002 in. per side or the outer ring is made to the same geometry as the tantalum die, all the stresses and wall distortions are within the desired range. Thus, the recommendation is to use a 0.006 in. diameter wire and a 0.003 in. interference fit for the europium oxide die and a 0.01 in. diameter wire and a 0.001 in. interference fit for the tantalum die. The dies can also be made to have the

  14. In vivo reprogramming for tissue repair.

    PubMed

    Heinrich, Christophe; Spagnoli, Francesca M; Berninger, Benedikt

    2015-03-01

    Vital organs such as the pancreas and the brain lack the capacity for effective regeneration. To overcome this limitation, an emerging strategy consists of converting resident tissue-specific cells into the cell types that are lost due to disease by a process called in vivo lineage reprogramming. Here we discuss recent breakthroughs in regenerating pancreatic β-cells and neurons from various cell types, and highlight fundamental challenges that need to be overcome for the translation of in vivo lineage reprogramming into therapy.

  15. Dying and multiplying life.

    PubMed

    Rodríguez-Arias, David

    2014-09-01

    It was only after James P. Lovette's death, in 2006, that I discovered that the twenty-four-year-old colleague and friend with whom I had spent so many afternoons debating issues in organ transplantation had been the first successful child heart transplantee in the world and one of the longest-living survivors of a second transplant. During the years we met, he never even hinted at the fact that three different hearts had beaten in his chest. The revelation that his life had been an almost uninterrupted chain of medical challenges suddenly made me appreciate his quirkiness in a whole new light. Organ transplantation crudely exemplifies a traditional moral dilemma between means and ends: in order to save a life, someone else has to die. Bioethicists involved in this field have the role of identifying the ethical issues surrounding organ donation and helping others to argue in an intelligible and convincing way. In my view, bioethicists have the obligation to foster a discussion as open and transparent as possible on these matters. Still, I sometimes fear that I may be helping to cause unnecessary harms to potential recipients who are desperately waiting for a vital organ. Scholars would be chillingly cold if their quest for truth systematically came at the cost of lives lost. Every life can be meaningful and provide meaning to many others. This is true even with organ recipients, who often have short lives full of considerable suffering. PMID:25231665

  16. The Dying Day

    NASA Astrophysics Data System (ADS)

    Heiles, Carl

    1993-05-01

    The 85-foot telescope's dying day was part of a week of memorably unusual weather---which, in turn, was part of a memorable winter in California (and elsewhere!). On this day, it spent several hours finishing a months-long, apparently successful observation of Zeeman splitting of the 18-cm OH lines in absorption against the Galactic center continuum source Sgr A. Later, it continued a survey of weak diffuse radio recombination lines near the Galactic plane---observations that were interrupted by strong winds, which made the telescope move to the stow position. We know the rest. Had the telescope not been destroyed, it would have been reconfigured the following day to observe the 21-cm line. It would have continued an ongoing survey of interstellar magnetic fields using Zeeman splitting of the 21-cm line. It would have begun a search for broad, weak line wings, which had been previously discovered in association with supernova remnants. It would have been involved in a number of H I mapping projects. And it would have continued its measurements of diffuse radio recombination lines. Had it not been for the inclement weather, the weekend would have seen it being used in laboratory exercises for undergraduates at UC Berkeley.

  17. How dying cells alert the immune system to danger

    PubMed Central

    Kono, Hajime; Rock, Kenneth L.

    2009-01-01

    When a cell dies in vivo the event does not go unnoticed. The host has evolved mechanisms to detect the death of cells and rapidly investigate the nature of their demise. If cell death is a result of natural causes, that is, it is part of normal physiological processes, then there is little threat to the organism. In this situation, little else is done other than removing the corpse. However, if cells have died as the consequence of some violence or disease, then both defence and repair mechanisms are mobilized. The importance of this process to host defence and disease pathogenesis has only been appreciated relatively recently. This article will review our current knowledge of these processes. PMID:18340345

  18. In vitro and in vivo corrosion of the novel magnesium alloy Mg-La-Nd-Zr: influence of the measurement technique and in vivo implant location.

    PubMed

    Reifenrath, J; Marten, A-K; Angrisani, N; Eifler, R; Weizbauer, A

    2015-08-12

    For the evaluation of new magnesium-based alloys, many different in vitro and in vivo methods are used. It was the aim of the current study to perform in vitro and in vivo corrosion studies of the new alloy Mg-La-Nd-Zr for its evaluation as a promising new degradable material and to compare commonly used evaluation methods. Die casted and subsequent extruded cylindrical pins (Ø1.5 mm; length 7 mm, [Formula: see text]) were implanted subcutaneously ([Formula: see text]), intramuscular ([Formula: see text]) and intramedullary ([Formula: see text]) in female Lewis rats with a postoperative follow up of 8 weeks; subsequent μ-computed tomographical analyses (XTremeCT and μCT80) were performed as well as weight analysis prior to and after implantation. Cubes (5 mm  ×  4 mm  ×  4 mm; surface area, 1.12 cm(2); [Formula: see text]) were used for in vitro corrosion (HBSS and RPMI 1640 + 10% FBS medium) and cytocompatibility studies (L929 cells). First of all it could be stated that implant location strongly influences the in vivo corrosion rate. In particular, intramedullary implanted pins corroded faster than pins in a subcutaneous or intramuscular environment. Considering the different evaluation methods, the calculated ex vivo μCT-based corrosion rates resulted in comparable values to the corrosion rates calculated by the weight loss method, especially after chromatic acid treatment of the explanted pins. The in vitro methods used tend to show similar corrosion rates compared to in vivo corrosion, especially when a RPMI medium was used, and therefore are suitable to predict corrosion trends prior to in vivo studies. Regarding cytocompatibility, the novel magnesium alloy Mg-La-Nd-Zr showed sufficient cell viability and therefore can be considered as a promising alloy for further applications.

  19. In vivo dosimetry in external beam radiotherapy

    SciTech Connect

    Mijnheer, Ben; Beddar, Sam; Izewska, Joanna; Reft, Chester

    2013-07-15

    In vivo dosimetry (IVD) is in use in external beam radiotherapy (EBRT) to detect major errors, to assess clinically relevant differences between planned and delivered dose, to record dose received by individual patients, and to fulfill legal requirements. After discussing briefly the main characteristics of the most commonly applied IVD systems, the clinical experience of IVD during EBRT will be summarized. Advancement of the traditional aspects of in vivo dosimetry as well as the development of currently available and newly emerging noninterventional technologies are required for large-scale implementation of IVD in EBRT. These new technologies include the development of electronic portal imaging devices for 2D and 3D patient dosimetry during advanced treatment techniques, such as IMRT and VMAT, and the use of IVD in proton and ion radiotherapy by measuring the decay of radiation-induced radionuclides. In the final analysis, we will show in this Vision 20/20 paper that in addition to regulatory compliance and reimbursement issues, the rationale for in vivo measurements is to provide an accurate and independent verification of the overall treatment procedure. It will enable the identification of potential errors in dose calculation, data transfer, dose delivery, patient setup, and changes in patient anatomy. It is the authors' opinion that all treatments with curative intent should be verified through in vivo dose measurements in combination with pretreatment checks.

  20. Toward Localized In Vivo Biomarker Concentration Measurements

    PubMed Central

    Zhang, Xiaojuan; Reeves, Daniel; Shi, Yipeng; Gimi, Barjor; Nemani, Krishnamurthy V.; Perreard, Irina M.; Toraya-Brown, Seiko; Fiering, Steven; Weaver, John B.

    2015-01-01

    We know a great deal about the biochemistry of cells because they can be isolated and studied. The biochemistry of the much more complex in vivo environment is more difficult to study because the only ways to quantitate concentrations is to sacrifice the animal or biopsy the tissue. Either method disrupts the environment profoundly and neither method allows longitudinal studies on the same individual. Methods of measuring chemical concentrations in vivo are very valuable alternatives to sacrificing groups of animals. We are developing microscopic magnetic nanoparticle (mNP) probes to measure the concentration of a selected molecule in vivo. The mNPs are targeted to bind the selected molecule and the resulting reduction in rotational freedom can be quantified remotely using magnetic spectroscopy. The mNPs must be contained in micrometer sized porous shells to keep them from migrating and to protect them from clearance by the immune system. There are two key issues in the development of the probes. First, we demonstrate the ability to measure concentrations in the porous walled alginate probes both in phosphate buffered saline and in blood, which is an excellent surrogate for the complex and challenging in vivo environment. Second, sensitivity is critical because it allows microscopic probes to measure very small concentrations very far away. We report sensitivity measurements on recently introduced technology that has allowed us to improve the sensitivity by two orders of magnitude, a factor of 200 so far. PMID:26203196

  1. HIV control in vivo: Dynamical analysis

    NASA Astrophysics Data System (ADS)

    Gumel, A. B.; Moghadas, S. M.

    2004-10-01

    A deterministic model for the immunological and therapeutic control of human immunodeficiency virus (HIV) in vivo is studied qualitatively. In addition to analyzing the local stability of the equilibria, the global stability of the infection-free equilibrium is established. The optimal efficacy level of anti-retroviral therapy needed to eradicate HIV from the body of an HIV-infected individual is obtained.

  2. Quantifying in vivo MR spectra with circles

    NASA Astrophysics Data System (ADS)

    Gabr, Refaat E.; Ouwerkerk, Ronald; Bottomley, Paul A.

    2006-03-01

    Accurate and robust quantification of in vivo magnetic resonance spectroscopy (MRS) data is essential to its application in research and medicine. The performance of existing analysis methods is problematic for in vivo studies where low signal-to-noise ratio, overlapping peaks and intense artefacts are endemic. Here, a new frequency-domain technique for MRS data analysis is introduced wherein the circular trajectories which result when spectral peaks are projected onto the complex plane, are fitted with active circle models. The use of active contour strategies naturally allows incorporation of prior knowledge as constraint energy terms. The problem of phasing spectra is eliminated, and baseline artefacts are dealt with using active contours-snakes. The stability and accuracy of the new technique, CFIT, is compared with a standard time-domain fitting tool, using simulated 31P data with varying amounts of noise and 98 real human chest and heart 31P MRS data sets. The real data were also analyzed by our standard frequency-domain absorption-mode technique. On the real data, CFIT demonstrated the least fitting failures of all methods and an accuracy similar to the latter method, with both these techniques outperforming the time-domain approach. Contrasting results from simulations argue that performance relative to Cramer-Rao Bounds may not be a suitable indicator of fitting performance with typical in vivo data such as these. We conclude that CFIT is a stable, accurate alternative to the best existing methods of fitting in vivo data.

  3. Towards in vivo TLD dosimetry in mammography.

    PubMed

    Warren-Forward, H M; Duggan, L

    2004-05-01

    While phantoms are used for quality control assessment of the mammography unit, in vivo dose measurements are necessary to account for the variation in size and composition of the female breast. The use of thermoluminescent dosimeters (TLDs) in mammography has been limited due to TLD visibility. The aim of this current investigation was to access the suitability of a paper-thin LiF:Mg,Cu,P TLD (GR-200F) for in vivo dosimetric mammography measurements. The visibility of GR-200F has been directly compared with LiF:Mg,Cu,P TLDs (GR-200A) using a number of commercially available phantoms. The phantoms of thickness 2-5 cm were imaged over the range of tube potentials (24-28 kVp) used clinically. Both types of TLD were placed on the surface of the phantoms allowing assessment of visibility, entrance surface dose (ESD) and field homogeneity. In vivo assessment of ESD and visibility was also carried out on a volunteer undergoing a routine mammography examination. The positions of the GR-200F TLDs were not identified either on the image of the Leeds TOR(MAM) phantom or the patient mammograms. The average ESD for the Leeds phantom was 8.8 mGy, while the patient ESD was 13 mGy. It is now possible to perform in vivo measurements with the potential of increasing the accuracy of the doses measured for women that do not conform to a standard breast thickness or density.

  4. In-vivo optical investigation of psoriasis

    NASA Astrophysics Data System (ADS)

    Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.

    2011-03-01

    Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. The average size of dot vessels in Psoriasis was measured to be 974 μm2 which is much higher compared to healthy skin. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.

  5. Streptococcus suis Serotype 2 Capsule In Vivo.

    PubMed

    Auger, Jean-Philippe; Meekhanon, Nattakan; Okura, Masatoshi; Osaki, Makoto; Gottschalk, Marcelo; Sekizaki, Tsutomu; Takamatsu, Daisuke

    2016-10-01

    Many Streptococcus suis isolates from porcine endocarditis in slaughterhouses have lost their capsule and are considered avirulent. However, we retrieved capsule- and virulence-recovered S. suis after in vivo passages of a nonencapsulated strain in mice, suggesting that nonencapsulated S. suis are still potentially hazardous for persons in the swine industry. PMID:27648583

  6. Aspergillus Biofilm In Vitro and In Vivo.

    PubMed

    Beauvais, Anne; Latgé, Jean-Paul

    2015-08-01

    In vivo, Aspergillus fumigatus grows as a typical biofilm with hyphae covered by an extracellular matrix (ECM) composed of polysaccharides, galactomannan, and galactosaminogalactan. α1,3 glucans and melanin are also constitutive of the ECM in aspergilloma but not in invasive aspergillosis. In vitro, two biofilm models were established to mimic the in vivo situation. The first model (model 1) uses submerged liquid conditions and is characterized by slow growth, while the second model (model 2) uses agar medium and aerial conditions and is characterized by rapid growth. The composition of the ECM was studied only in the second model and has been shown to be composed of galactomannan, galactosaminogalactan (GAG), and α1,3 glucans, melanin, antigens, and hydrophobins. The presence of extracellular DNA was detected in model 1 biofilm but not in model 2. Transcriptomic analysis employing both biofilm models showed upregulation of genes coding for proteins involved in the biosynthesis of secondary metabolites, adhesion, and drug resistance. However, most data on A. fumigatus biofilms have been obtained in vitro and should be confirmed using in vivo animal models. There is a need for new therapeutic antibiofilm strategies that focus on the use of combination therapy, since biofilm formation poses an important clinical problem due to their resistance to antifungal agents. Furthermore, in vivo investigations of A. fumigatus biofilms that incorporate the associated microbiota are needed. Such studies will add another layer of complexity to our understanding of the role of A. fumigatus biofilm during lung invasion. PMID:26350307

  7. Streptococcus suis Serotype 2 Capsule In Vivo

    PubMed Central

    Auger, Jean-Philippe; Meekhanon, Nattakan; Okura, Masatoshi; Osaki, Makoto; Gottschalk, Marcelo; Sekizaki, Tsutomu

    2016-01-01

    Many Streptococcus suis isolates from porcine endocarditis in slaughterhouses have lost their capsule and are considered avirulent. However, we retrieved capsule- and virulence-recovered S. suis after in vivo passages of a nonencapsulated strain in mice, suggesting that nonencapsulated S. suis are still potentially hazardous for persons in the swine industry. PMID:27648583

  8. BMPER regulates cardiomyocyte size and vessel density in vivo

    PubMed Central

    Willis, Monte S.; Dyer, Laura A.; Ren, Rongqin; Lockyer, Pamela; Moreno-Miralles, Isabel; Schisler, Jonathan C.; Patterson, Cam

    2016-01-01

    Background BMPER, an orthologue of Drosophila melanogaster Crossveinless-2, is a secreted factor that regulates bone morphogenetic protein activity in endothelial cell precursors and during early cardiomyocyte differentiation. Although previously described in the heart, the role of BMPER in cardiac development and function remain unknown. Methods BMPER-deficient hearts were phenotyped histologically and functionally using echocardiography and Doppler analysis. Since BMPER −/− mice die perinatally, adult BMPER +/− mice were challenged to pressure-overload-induced cardiac hypertrophy and hindlimb ischemia to determine changes in angiogenesis and regulation of cardiomyocyte size. Results We identify for the first time the cardiac phenotype associated with BMPER haploinsufficiency. BMPER messenger RNA and protein are present in the heart during cardiac development through at least E14.5 but is lost by E18.5. BMPER +/− ventricles are thinner and less compact than sibling wild-type hearts. In the adult, BMPER +/− hearts present with decreased anterior and posterior wall thickness, decreased cardiomyocyte size and an increase in cardiac vessel density. Despite these changes, BMPER +/− mice respond to pressure-overload-induced cardiac hypertrophy challenge largely to the same extent as wild-type mice. Conclusion BMPER appears to play a role in regulating both vessel density and cardiac development in vivo; however, BMPER haploinsufficiency does not result in marked effects on cardiac function or adaptation to pressure overload hypertrophy. PMID:23200275

  9. Improving care of dying children.

    PubMed Central

    Martinson, I M

    1995-01-01

    Every year about 5,000 children aged 0 to 14 years need hospice care in the United States. Children seem to know that they are dying, although this is difficult for parents to accept. Clear, empathic understanding is needed. Communication with clarity and understanding is imperative with the changes in goals from cure to palliation to comfort. The ideal place for most dying children is at home, where symptoms can be managed as effectively as in a hospital. PMID:7571589

  10. REFRACTORY DIE FOR EXTRUDING URANIUM

    DOEpatents

    Creutz, E.C.

    1959-08-11

    A die is presented for the extrusion of metals, said die being formed of a refractory complex oxide having the composition M/sub n/O/sub m/R/sub x/O/sub y/ where M is magnesium, zinc, manganese, or iron, R is aluminum, chromic chromium, ferric iron, or manganic manganese, and m, n, x, and y are whole numbers. Specific examples are spinel, magnesium aluminate, magnetite, magnesioferrite, chromite, and franklinite.

  11. Quantification of carbon nanomaterials in vivo.

    PubMed

    Wang, Haifang; Yang, Sheng-Tao; Cao, Aoneng; Liu, Yuanfang

    2013-03-19

    A diverse array of carbon nanomaterials (NMs), including fullerene, carbon nanotubes (CNTs), graphene, nanodiamonds, and carbon nanoparticles, have been discovered and widely applied in a variety of industries. Carbon NMs have been detected in the environment and have a strong possibility of entering the human body. The safety of carbon NMs has thus become a serious concern in academia and society. To achieve strict biosafety assessments, researchers need to fully understand the effects and fates of NMs in the human body, including information about absorption, distribution, metabolism, excretion, and toxicity (ADME/T). To acquire the ADME data, researchers must quantify NMs, but carbon NMs are very difficult to quantify in vivo. The carbon background in a typical biological system is high, particularly compared with the much lower concentration of carbon NMs. Moreover, carbon NMs lack a specific detection signal. Therefore, isotopic labeling, with its high sensitivity and specificity, is the first choice to quantify carbon NMs in vivo. Previously, researchers have used many isotopes, including ¹³C, ¹⁴C, ¹²⁵I, ¹³¹I, ³H, ⁶⁴Cu, ¹¹¹In, ⁸⁶Y, 99mTc, and ⁶⁷Ga, to label carbon NMs. We used these isotopic labeling methods to study the ADME of carbon NMs via different exposure pathways in animal models. Except for the metabolism of carbon NMs, which has seldom been investigated, significant amounts of data have been reported on the in vivo absorption, distribution, excretion, and toxicity of carbon NMs, which have revealed characteristic behaviors of carbon NMs, such as reticuloendothelial system (RES) capture. However, the complexity of the biological systems and diverse preparation and functionalization of the same carbon NMs have led to inconsistent results across different studies. Therefore, the data obtained so far have not provided a compatible and systematic profile of biosafety. Further efforts are needed to address these problems. In

  12. Dying at the best time.

    PubMed

    Seale, C; Addington-Hall, J

    1995-03-01

    These are the results of two surveys of relatives, and others who knew people who had died, describing events in the year before death and their views on the time of the person's death. Those surveyed were identified from death certificates in England. The main focus is on a sample of 3696 people dying in 1990 in 20 health authorities, with supporting analysis from an earlier national sample of 639 people dying in 1987. Variation in peoples' views about whether an earlier death would have been better is reported, in the context of debate about euthanasia. Spouses were less likely than others to feel that it would have been better if the person had died earlier, and this held true even when controlling for the deceaseds' levels of pain, distress, dependency and age. Spouses were more likely than others to say that a later death would have been better, though not in cases where the deceased was reported as having said they wanted to die sooner. Spouses were influenced by the loss which the death of the person represented for them, being more likely than others to say they missed the person who died a great deal, and feel loneliness was a big problem. Non spouses (children and other relatives of the deceased, friends, neighbours and a few officials) on the other hand were more likely than spouses to say an earlier death would have been better, even when levels of pain, distress, dependency and age were controlled for.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. In Vivo Imaging of Quantum Dots

    NASA Astrophysics Data System (ADS)

    Texier, Isabelle; Josser, Véronique

    Noninvasive whole-body near-infrared fluorescence imaging is now acknowledged as a powerful method for the molecular mapping of biological events in live small animals such as mouse models. With outstanding optical properties such as high fluorescence quantum yields and low photobleaching rates, quantum dots (QDs) are labels of choice in the near-infrared domain. The main applications described in the literature for in vivo imaging of mice after injection of QDs encompass imaging of lymph nodes and tumors and cell tracking. Standard methods for the preparation, the purification, and the in vivo fluorescence whole-body imaging of QDs in the live mouse are described. Nanoparticles coated by PEG chains of different sizes and terminal groups are prepared using 705-nm-emitting commercial QDs. Their biodistribution after intravenous or intradermal injections in tumor-bearing mice is reported here.

  14. In vivo imaging of pancreatic endocrine islets

    NASA Astrophysics Data System (ADS)

    Villiger, Martin; Goulley, Joan; Pache, Christophe; Friedrich, Michael; Grapin-Botton, Anne; Meda, Paolo; Leitgeb, Rainer; Lasser, Theo

    2009-07-01

    Extended focus optical coherence microscope (xfOCM) circumvents the compromise between lateral resolution and depth of field by us of a Bessel-like illumination beam. The high sensitivity and parallel depth profiling of Fourier domain optical coherence tomography are preserved, and combined with high isotropic resolution of 1.5 - 2 μm. To comply with the requirements for in vivo measurements, beam scanning had to be implemented. We then performed measurements, first of excised pancreas, validated by standard immunohistochemistry, to investigate the structures that can be observed. For a quantitative analysis, a semi-automatic islet detection algorithm evaluated the islet size, position, contrast and homogeneity. The influence of streptozotocin on the signature of the islets was investigated in a next step. Finally, xfOCM was applied to make measurements of the murine pancreas in situ and in vivo, visualizing pancreatic lobules, ducts, blood vessels and individual islets of Langerhans.

  15. In vivo Cytotoxicity Studies of Amaryllidaceae Alkaloids.

    PubMed

    Nair, Jerald J; Bastida, Jaume; van Staden, Johannes

    2016-01-01

    The plant family Amaryllidaceae is recognizable for its esthetic floral characteristics, its widespread usage in traditional medicine as well as its unique alkaloid principles. Few alkaloid-producing families rival the Amaryllidaceae in terms of the diversity of its structures as well as their wide applicability on the biological landscape. In particular, cytotoxic effects have come to be a dominant theme in the biological properties of Amaryllidacea alkaloids. To this extent, a significant number of structures have been subjected to in vitro studies in numerous cell lines from which several targets have been identified as promising chemotherapeutics. By contrast, in vivo models of study involving these alkaloids have been carried out to a lesser extent and should prove crucial in the continued development of a clinical target such as pancratistatin. This survey examines the cytotoxic effects of Amaryllidaceae alkaloids in vivo and contrasts these against the corresponding in vitro effects.

  16. High-resolution MRI: in vivo histology?

    PubMed Central

    Bridge, Holly; Clare, Stuart

    2005-01-01

    For centuries scientists have been fascinated with the question of how the brain works. Investigators have looked at both where different functions are localized and how the anatomical microstructure varies across the brain surface. Here we discuss how advances in magnetic resonance imaging (MRI) have allowed in vivo visualization of the fine structure of the brain that was previously only visible in post-mortem brains. We present data showing the correspondence between definitions of the primary visual cortex defined anatomically using very high-resolution MRI and functionally using functional MRI. We consider how this technology can be applied to allow the investigation of brains that differ from normal, and what this ever-evolving technology may be able to reveal about in vivo brain structure in the next few years. PMID:16553313

  17. In vivo apoptosis in Shigella flexneri infections.

    PubMed Central

    Zychlinsky, A; Thirumalai, K; Arondel, J; Cantey, J R; Aliprantis, A O; Sansonetti, P J

    1996-01-01

    Shigella flexneri, an etiological agent of bacillary dysentery, causes apoptosis in vitro. Here we show that it also induces apoptosis in vivo. We were able to quantify the number of apoptotic cells in rabbit Peyer's patches infected with S. flexneri by detecting cells with fragmented DNA. Infection with virulent S. flexneri results in massive numbers of apoptotic cells within the lymphoid follicles. In contrast, neither an avirulent strain nor an avirulent strain capable of colonizing Peyer's patches increases the background level of apoptotic cells. Macrophages, T cells, and B cells are shown to undergo apoptosis in vivo. These results indicate that apoptosis may play a crucial role in the pathogenesis of shigellosis. PMID:8945588

  18. In vivo testing of a biostable polyurethane.

    PubMed

    Szycher, M; Reed, A M; Siciliano, A A

    1991-10-01

    At present all the commercially available "medical grade" urethane elastomers exhibit a phenomenon known as environmental stress cracking (ESC). This phenomenon is characterized by surface microcracking when the elastomer is elongated while in vivo. The degree of strain that is required to initiate microcracking varies from composition to composition. It has been found that harder compounds generally tend to have a higher strain threshold than corresponding softer ones. We theorized that this degradation occurs when certain enzymes (present only in vivo) attack and break down the ether linkages that link the polymer molecules together. Those elastomers that contain more ether linkages (such as the softer compositions) appear to microcrack more easily than elastomers with fewer ether linkages (such as the harder ones). The molecular composition of ChronoFlex urethane has been chosen so that the finished elastomer will be free of ether linkages; thus, it is expected to be immune from environmental stress cracking. PMID:1779410

  19. In vivo RNAi: Today and Tomorrow

    PubMed Central

    Perrimon, Norbert; Ni, Jian-Quan; Perkins, Lizabeth

    2010-01-01

    SUMMARY RNA interference (RNAi) provides a powerful reverse genetics approach to analyze gene functions both in tissue culture and in vivo. Because of its widespread applicability and effectiveness it has become an essential part of the tool box kits of model organisms such as Caenorhabditis elegans, Drosophila, and the mouse. In addition, the use of RNAi in animals in which genetic tools are either poorly developed or nonexistent enables a myriad of fundamental questions to be asked. Here, we review the methods and applications of in vivo RNAi to characterize gene functions in model organisms and discuss their impact to the study of developmental as well as evolutionary questions. Further, we discuss the applications of RNAi technologies to crop improvement, pest control and RNAi therapeutics, thus providing an appreciation of the potential for phenomenal applications of RNAi to agriculture and medicine. PMID:20534712

  20. In vivo bioreactors for mandibular reconstruction.

    PubMed

    Tatara, A M; Wong, M E; Mikos, A G

    2014-12-01

    Large mandibular defects are difficult to reconstruct with good functional and aesthetic outcomes because of the complex geometry of craniofacial bone. While the current gold standard is free tissue flap transfer, this treatment is limited in fidelity by the shape of the harvested tissue and can result in significant donor site morbidity. To address these problems, in vivo bioreactors have been explored as an approach to generate autologous prefabricated tissue flaps. These bioreactors are implanted in an ectopic site in the body, where ossified tissue grows into the bioreactor in predefined geometries and local vessels are recruited to vascularize the developing construct. The prefabricated flap can then be harvested with vessels and transferred to a mandibular defect for optimal reconstruction. The objective of this review article is to introduce the concept of the in vivo bioreactor, describe important preclinical models in the field, summarize the human cases that have been reported through this strategy, and offer future directions for this exciting approach.

  1. A system to study aneuploidy in vivo

    PubMed Central

    Pfau, Sarah J.; Amon, Angelika

    2016-01-01

    Aneuploidy, an imbalanced chromosome number, is associated with both cancer and developmental disorders such as Down syndrome (DS). To determine how aneuploidy affects cellular and organismal physiology, we have developed a system to evaluate aneuploid cell fitness in vivo. By transplanting hematopoietic stem cells (HSCs) into recipient mice after ablation of recipient hematopoiesis by lethal irradiation, we can directly compare the fitness of HSCs derived from a range of aneuploid mouse models with that of euploid HSCs. This experimental system can also be adapted to assess the interplay between aneuploidy and tumorigenesis. We hope that further characterization of aneuploid cells in vivo will provide insight both into the origins of hematopoietic phenotypes observed in DS individuals as well as the role of different types of aneuploid cells in the genesis of cancers of the blood. PMID:26936868

  2. Photosensitizer quantitation in vivo by flourescence microsampling

    NASA Astrophysics Data System (ADS)

    Pogue, Brian W.; Burke, Gregory C.; Lee, Claudia C.; Hoopes, P. Jack

    2000-06-01

    Photodynamic therapy can provide a reliable method of tumor destruction when the appropriate dosimetry is applied. Current dosimetry practice involves quantification of the drug and light doses applied to the tumor, but it would be desirable to monitor in vivo light and drug levels to provide the most accurate determination of dosimetry. In vivo measurements can be used to minimize variations in treatment response due to inter-animal variability, by providing animal-specific or patient-specific treatment planning. This study reports on the development of a micro-sampling method to measure fluorescence from tissue, which is not significantly affected by the tissue optical properties. The system measures fluorescence from the surface of a tissue, using a fiber bundle composed of individual 100 micron fibers which ar all spaced apart by 700 microns from one another at the tissue contact end. This design provides sampling of the fluorescence at multiple sites to increase the signal intensity, while maintaining a micro- sampling of the tissue volume just below the surface. The calibration studies here indicate that the 1/e sampling depth is near 60 microns when measured in optical phantoms, which are similar to typical tissue properties. The probe fluorescence signal is independent of blood concentration up to a maximum of 10% blood by volume, which is similar to most tumor tissue. Animal tests indicate that the sensitivity to drug concentration is essentially the same in when measured in murine liver and muscle tissues, both in vivo and ex vivo. These preliminary calibration results suggest that the probe can be used to measure photosensitizer uptake in vivo non- invasively and rapidly via conversion of fluorescence intensity to photosensitizer concentration.

  3. In Vivo Radiobioassay and Research Facility

    SciTech Connect

    Lynch, Timothy P.

    2011-02-01

    Bioassay monitoring for intakes of radioactive material is an essential part of the internal dosimetry program for radiation workers at the Department of Energy’s (DOE) Hanford Site. This monitoring program includes direct measurements of radionuclides in the body by detecting photons that exit the body and analyses of radionuclides in excreta samples. The specialized equipment and instrumentation required to make the direct measurements of these materials in the body are located at the In Vivo Radiobioassay and Research Facility (IVRRF). The IVRRF was originally built in 1960 and was designed expressly for the in vivo measurement of radioactive material in Hanford workers. Most routine in vivo measurements are performed annually and special measurements are performed as needed. The primary source terms at the Hanford Site include fission and activation products (primarily 137Cs and 90Sr), uranium, uranium progeny, and transuranic radionuclides. The facility currently houses five shielded counting systems, men’s and women’s change rooms and an instrument maintenance and repair shop. Four systems include high purity germanium detectors and one system utilizes large sodium iodide detectors. These systems are used to perform an average of 7,000 measurements annually. This includes approximately 5000 whole body measurements analyzed for fission and activation products and 2000 lung measurements analyzed for americium, uranium, and plutonium. Various other types of measurements are performed periodically to estimate activity in wounds, the thyroid, the liver, and the skeleton. The staff maintains the capability to detect and quantify activity in essentially any tissue or organ. The in vivo monitoring program that utilizes the facility is accredited by the Department of Energy Laboratory Accreditation Program for direct radiobioassay.

  4. Zwitterionic hydrogels: an in vivo implantation study.

    PubMed

    Zhang, Zheng; Chao, Timothy; Liu, Lingyun; Cheng, Gang; Ratner, Buddy D; Jiang, Shaoyi

    2009-01-01

    Zwitterionic hydrogels, including poly(sulfobetaine methacrylate) (polySBMA) and poly(carboxybetaine methacrylate) (polyCBMA), and co-polymeric hydrogels of CBMA and 2-hydroxyethyl methacrylate (HEMA) (poly(CBMA-co-HEMA)) were prepared. Their in vitro and in vivo properties were evaluated and compared with those of polyHEMA hydrogels. Bovine aortic endothelial cells (BAECs) were incubated with zwitterionic and polyHEMA hydrogels to evaluate their bioadhesion properties. Both polySBMA and polyCBMA hydrogels were found to be non-cytotoxic and their endotoxin levels were found to be acceptable for in vivo implantation. Results from in vivo subcutaneous implantation showed reduced cell attachment to the surfaces of polySBMA and poly(CBMA-co-HEMA) hydrogels after one-week implantation as compared with polyHEMA hydrogels. After a 4-week implantation, capsules with higher vascularities surrounding the two zwitterionic hydrogels were found. However, polyHEMA, polySBMA and poly(CBMA-co-HEMA) hydrogels showed similar capsule thicknesses and similar numbers of attached foreign body giant cells (FBGCs). In this work, zwitterionic hydrogels demonstrate healing and integration comparable to polyHEMA hydrogels, but with improved vascularity. These zwitterionic hydrogels are promising alternatives to polyHEMA hydrogels as implantable materials. PMID:19793443

  5. Systematic Discovery of In Vivo Phosphorylation Networks

    PubMed Central

    Linding, Rune; Jensen, Lars Juhl; Ostheimer, Gerard J.; van Vugt, Marcel A.T.M.; Jørgensen, Claus; Miron, Ioana M.; Diella, Francesca; Colwill, Karen; Taylor, Lorne; Elder, Kelly; Metalnikov, Pavel; Nguyen, Vivian; Pasculescu, Adrian; Jin, Jing; Park, Jin Gyoon; Samson, Leona D.; Woodgett, James R.; Russell, Robert B.; Bork, Peer; Yaffe, Michael B.; Pawson, Tony

    2009-01-01

    Summary Protein kinases control cellular decision processes by phosphorylating specific substrates. Proteome-wide mapping has identified thousands of in vivo phosphorylation sites. However, systematically resolving which kinase targets each site is presently infeasible, due to the limited specificity of consensus motifs and the potential influence of contextual factors, such as protein scaffolds, localisation and expression, on cellular substrate specificity. We have therefore developed a computational method, NetworKIN, that augments motifs with context for kinases and phosphoproteins. This can pinpoint individual kinases responsible for specific in vivo phosphorylation events and yields a 2.5-fold improvement in the accuracy with which phosphorylation networks can be constructed. We show that context provides 60–80% of the computational capability to assign in vivo substrate specificity. Applying this approach to a DNA damage signalling network, we extend its cell-cycle regulation by showing that 53BP1 is a CDK1 substrate, show that Rad50 is phosphorylated by ATM kinase under genotoxic stress, and suggest novel roles of ATM in apoptosis. Finally, we present a scalable strategy to validate our predictions and use it to support the prediction that BCLAF1 is a GSK3 substrate. PMID:17570479

  6. Luminescent probes for optical in vivo imaging

    NASA Astrophysics Data System (ADS)

    Texier, Isabelle; Josserand, Veronique; Garanger, Elisabeth; Razkin, Jesus; Jin, Zhaohui; Dumy, Pascal; Favrot, Marie; Boturyn, Didier; Coll, Jean-Luc

    2005-04-01

    Going along with instrumental development for small animal fluorescence in vivo imaging, we are developing molecular fluorescent probes, especially for tumor targeting. Several criteria have to be taken into account for the optimization of the luminescent label. It should be adapted to the in vivo imaging optical conditions : red-shifted absorption and emission, limited overlap between absorption and emission for a good signal filtering, optimized luminescence quantum yield, limited photo-bleaching. Moreover, the whole probe should fulfill the biological requirements for in vivo labeling : adapted blood-time circulation, biological conditions compatibility, low toxicity. We here demonstrate the ability of the imaging fluorescence set-up developed in LETI to image the bio-distribution of molecular probes on short times after injection. Targeting with Cy5 labeled holo-transferrin of subcutaneous TS/Apc (angiogenic murine breast carcinoma model) or IGROV1 (human ovarian cancer) tumors was achieved. Differences in the kinetics of the protein uptake by the tumors were evidenced. IGROV1 internal metastatic nodes implanted in the peritoneal cavity could be detected in nude mice. However, targeted metastatic nodes in lung cancer could only be imaged after dissection of the mouse. These results validate our fluorescence imaging set-up and the use of Cy5 as a luminescent label. New fluorescent probes based on this dye and a molecular delivery template (the RAFT molecule) can thus be envisioned.

  7. In vivo human crystalline lens topography

    PubMed Central

    Ortiz, Sergio; Pérez-Merino, Pablo; Gambra, Enrique; de Castro, Alberto; Marcos, Susana

    2012-01-01

    Custom high-resolution high-speed anterior segment spectral domain optical coherence tomography (OCT) was used to characterize three-dimensionally (3-D) the human crystalline lens in vivo. The system was provided with custom algorithms for denoising and segmentation of the images, as well as for fan (scanning) and optical (refraction) distortion correction, to provide fully quantitative images of the anterior and posterior crystalline lens surfaces. The method was tested on an artificial eye with known surfaces geometry and on a human lens in vitro, and demonstrated on three human lenses in vivo. Not correcting for distortion overestimated the anterior lens radius by 25% and the posterior lens radius by more than 65%. In vivo lens surfaces were fitted by biconicoids and Zernike polynomials after distortion correction. The anterior lens radii of curvature ranged from 10.27 to 14.14 mm, and the posterior lens radii of curvature ranged from 6.12 to 7.54 mm. Surface asphericities ranged from −0.04 to −1.96. The lens surfaces were well fitted by quadrics (with variation smaller than 2%, for 5-mm pupils), with low amounts of high order terms. Surface lens astigmatism was significant, with the anterior lens typically showing horizontal astigmatism (Z22 ranging from −11 to −1 µm) and the posterior lens showing vertical astigmatism (Z22 ranging from 6 to 10 µm). PMID:23082289

  8. Recruitment of RNA polymerase III in vivo.

    PubMed

    Kenneth, Niall S; Marshall, Lynne; White, Robert J

    2008-06-01

    RNA polymerase (pol) III contains a dissociable subcomplex that is required for initiation, but not for elongation or termination of transcription. This subcomplex is composed of subunits RPC3, RPC6 and RPC7, and interacts with TFIIIB, a factor that is necessary and sufficient to support accurate pol III transcription in vitro. Direct binding of TFIIIB to RPC6 is believed to recruit pol III to its genetic templates. However, this has never been tested in vivo. Here we combine chromatin immunoprecipitation with RNA interference to demonstrate that the RPC3/6/7 subcomplex is required for pol III recruitment in mammalian cells. Specific knockdown of RPC6 by RNAi results in post-transcriptional depletion of the other components of the subcomplex, RPC3 and RPC7, without destabilizing core pol III subunits or TFIIIB. The resultant core enzyme is defective in associating with TFIIIB and target genes in vivo. Promoter occupancy by pol II is unaffected, despite sharing five subunits with the pol III core. These observations provide evidence for the validity in vivo of the model for pol III recruitment that was built on biochemical data.

  9. Shigella impairs T lymphocyte dynamics in vivo

    PubMed Central

    Salgado-Pabón, Wilmara; Celli, Susanna; Arena, Ellen T.; Nothelfer, Katharina; Roux, Pascal; Sellge, Gernot; Frigimelica, Elisabetta; Bousso, Philippe; Sansonetti, Philippe J.; Phalipon, Armelle

    2013-01-01

    The Gram-negative enteroinvasive bacterium Shigella flexneri is responsible for the endemic form of bacillary dysentery, an acute rectocolitis in humans. S. flexneri uses a type III secretion system to inject effector proteins into host cells, thus diverting cellular functions to its own benefit. Protective immunity to reinfection requires several rounds of infection to be elicited and is short-lasting, suggesting that S. flexneri interferes with the priming of specific immunity. Considering the key role played by T-lymphocyte trafficking in priming of adaptive immunity, we investigated the impact of S. flexneri on T-cell dynamics in vivo. By using two-photon microscopy to visualize bacterium–T-cell cross-talks in the lymph nodes, where the adaptive immunity is initiated, we provide evidence that S. flexneri, via its type III secretion system, impairs the migration pattern of CD4+ T cells independently of cognate recognition of bacterial antigens. We show that bacterial invasion of CD4+ T lymphocytes occurs in vivo, and results in cell migration arrest. In the absence of invasion, CD4+ T-cell migration parameters are also dramatically altered. Signals resulting from S. flexneri interactions with subcapsular sinus macrophages and dendritic cells, and recruitment of polymorphonuclear cells are likely to contribute to this phenomenon. These findings indicate that S. flexneri targets T lymphocytes in vivo and highlight the role of type III effector secretion in modulating host adaptive immune responses. PMID:23417297

  10. Use of RSP Tooling to Manufacture Die Casting Dies

    SciTech Connect

    Kevin McHugh

    2004-07-01

    The technology and art used to construct die casting dies has seen many improvements over the years. However, the time lag from when a design is finalized to the time a tool is in production has remained essentially the same. The two main causes for the bottleneck are the need to qualify a part design by making prototypes (usually from an alternative process), and the production tooling lead time after the prototypes are approved. Production tooling costs are high due to the labor and equipment costs associated with transforming a forged block of tool steel into a finished tool. CNC machining, sink EDM, benching, engraving and heat treatment unit operations are typically involved. As a result, there is increasing interest in rapid tooling (RT) technologies that shorten the design-to-part cycle and reduce the cost of dies. There are currently more than 20 RT methods being developed and refined around the world (1). The "rapid" in rapid tooling suggests time compression for tool delivery, but does not address robustness as nearly all RT approaches are intended for low-volume prototype work, primarily for molding plastics. Few options exist for die casting. An RT technology suitable for production-quality tooling in the time it normally takes for prototype tooling is highly desirable. In fact, there would be no need for a distinction between prototype and production tooling. True prototype parts could be made using the same processing conditions and materials intended for production. Qualification of the prototype part would allow the manufacturer to go directly into production with the same tool. A relatively new RT technology, Rapid Solidification Process (RSP) Tooling, is capable of making production-quality tooling in an RT timeframe for die casting applications. RSP Tooling, was developed at the Idaho National Engineering and Environmental Laboratory (INEEL), and commercialized with the formation of RSP Tooling, LLC (2). This paper describes the process, and

  11. Recent advances on in vivo imaging with fluorescent proteins.

    PubMed

    Hoffman, Robert M

    2008-01-01

    In vivo imaging with green fluorescent protein (GFP) and other fluorescent proteins is revolutionizing cancer biology and other fields of in vivo biology (Hoffman, 2005; Hoffman and Yang, 2006a,b,c). Our laboratory pioneered the use of GFP for in vivo imaging in 1997 (Chishima et al., 1997). This chapter highlights recent developments from our laboratory on both macro and micro in vivo imaging by using fluorescent proteins.

  12. Clinical management of dying patients.

    PubMed Central

    Gavrin, J; Chapman, C R

    1995-01-01

    Dying is universal, and death should be a peaceful time. Myriad comfort measures are available in the last weeks before life ends. Discussions about end-of-life issues often suffer from lack of informed opinion. Palliative care experts have identified specific somatic and psychological sources of distress for dying patients and their loved ones. Pain, shortness of breath, nausea and vomiting, and fear of abandonment contribute substantially to both physical and psychological discomfort toward the end of life. Simple, effective methods exist for relieving those symptoms. Knowledge about the natural events associated with dying and an informed approach to medical and psychological interventions contribute to systematic and successful comfort care. We describe the origin of physical and psychological distress at the end of life and provide strategies for alleviating many of the discomforts. PMID:7571591

  13. Acting to let someone die.

    PubMed

    McGee, Andrew

    2015-02-01

    This paper examines the recent prominent view in medical ethics that withdrawing life-sustaining treatment (LST) is an act of killing. I trace this view to the rejection of the traditional claim that withdrawing LST is an omission rather than an act. Although that traditional claim is not as problematic as this recent prominent view suggests, my main claim is that even if we accepted that withdrawing LST should be classified as an act rather than as an omission, it could still be classified as letting die rather than killing. Even though omissions are contrasted with acts, letting die need not be, for one can let die by means of acts. The remainder of the paper is devoted to establishing this claim and addresses certain objections to it.

  14. On dying and human suffering.

    PubMed

    Kellehear, A

    2009-07-01

    This review compares and contrasts the major reoccurring themes in two sources of research literature - social studies of dying and human suffering. The purpose of such a comparison is to employ the major insights of each field as a useful method of critically evaluating the insights of the other. Critical exchanges and comparisons between the research area of dying studies and on human suffering have been modest to date. This article will explain that the experience of dying benefits from being situated and analysed in a broader context of cultural experience, as suggested by the theory and study of human suffering. Conversely, the theory and methods involved in studies of human suffering can gain from a mortal view of vulnerability, grief, social ambiguity and identity changes characteristic of experiences at the end of life.

  15. Clinical management of dying patients.

    PubMed

    Gavrin, J; Chapman, C R

    1995-09-01

    Dying is universal, and death should be a peaceful time. Myriad comfort measures are available in the last weeks before life ends. Discussions about end-of-life issues often suffer from lack of informed opinion. Palliative care experts have identified specific somatic and psychological sources of distress for dying patients and their loved ones. Pain, shortness of breath, nausea and vomiting, and fear of abandonment contribute substantially to both physical and psychological discomfort toward the end of life. Simple, effective methods exist for relieving those symptoms. Knowledge about the natural events associated with dying and an informed approach to medical and psychological interventions contribute to systematic and successful comfort care. We describe the origin of physical and psychological distress at the end of life and provide strategies for alleviating many of the discomforts.

  16. A new in vivo model using a dorsal skinfold chamber to investigate microcirculation and angiogenesis in diabetic wounds.

    PubMed

    Langer, Stefan; Beescho, Christian; Ring, Andrej; Dorfmann, Olivia; Steinau, Hans Ulrich; Spindler, Nick

    2016-01-01

    Einleitung: Diabetes Mellitus beschreibt die Dysregulation des Glukosemetabolismus auf Grund von pathologischer Insulin-Sekretion, reduzierter Insulin-Effizienz oder beidem. Es ist hinreichend bekannt, dass Patienten mit einem Diabetes mellitus an verlängerter Wundheilung leiden, da die Weichteilangiogenese hierdurch massiv beeinflusst wird. Bis zum jetzigen Zeitpunkt ist kein befriedigendes in vivo murine Modell etabliert, um die Dynamik der Angiogenese während einer diabetischen Wundheilung zu untersuchen. Um die pathophysiologischen Abläufe des Diabetes und seinen Einfluss auf die Angiogenese besser verstehen zu können, wurde ein neues in vivo murine Modell entwickelt bei welchem mittels einer Hautkammer die Veränderungen bei Mäusen sichtbar gemacht werden.Material und Methoden: Diabetische Mäuse (db; BKS.Cg-m+/+Lepr(db)/J), Wildtyp Mäuse (dock7Lepr(db)+/+m) sowie BALB/c Labormäuse wurden hierzu untersucht. Diese wurden in Einzelkäfigen gehalten mit selbstständigem Futterzugang in einem 12-stündigen Tag- und Nachtrhythmus. Muskelläsionen von 2 mm Durchmesser wurden im Zentrum des Hautkammerfensters gesetzt. Hierauf hin wurde die Wundheilung über einen Zeitraum von 22 Tagen verfolgt. Wichtige analytische Daten wie Gefäßdurchmesser, Fließgeschwindgkeit, Gefäßpermeabilität sowie das Kapillar-Leck von Muskelkapillaren sowie post-kapilläre Venolen konnten hierbei erhoben werden. Schlüsselparameter waren die functional capillary density (FCD) und die angiogenesis positive areas (APA).Ergebnisse: Wir haben ein Wundmodell etabliert, welches hoch aufgelöste in vivo Aufnahmen der funktionellen Angiogenese der diabetischen Wunde ermöglicht. Wie angenommen zeigten die db Mäuse eine gestörte Wundheilung (22. Tag) verglichen mit den Wunden einer BALB/c oder WT Maus (15. Tag). FCD war über den gesamten Verlauf bei den diabetischen Mäusen niedriger als bei WT oder BALB/c. Die Dynamik der Angiogenese nahm bei diabetischen Mäusen ab, was der niedrige

  17. Care of the Dying Adolescent

    PubMed Central

    MacDonald, Faye

    1979-01-01

    This is a description of the obstacles encountered in the management of one 17 year old patient dying with malignant melanoma. Various areas are seen to contribute to the difficulties including the “health care system” (specifically the hospital environment), the patient himself, his family, his disease and its treatment, and his physician(s). An increased awareness of the difficulties would be helpful to those of us not frequently encountering the responsibility of caring for a dying adolescent. The details have been left vague or slightly changed in this real case to respect the privacy of those involved. PMID:21297759

  18. [Dying with cancer: Hollywood lessons].

    PubMed

    Niemeyer, Fernanda; Kruse, Maria Henriqueta Luce

    2013-12-01

    The study attempts to understand how dying from cancer is portrayed by five movies produced in Hollywood between 1993 and 2006. Based on the cultural studies and their post-structuralism version and supported by the notions of discourse and subjectivity, as proposed by philosopher Michel Foucault, we suggest one of the possible readings of the movie picture corpus. We assess how the movie picture discourse acts as a cultural pedagogy that produces ways of seeing dying with cancer: immortalizing the healthy body image, silencing death, taking care of the dead body and, finally, accepting death. Our proposal is intended to stimulate reflections that may contribute to care and education in nursing.

  19. Portable punch and die jig

    DOEpatents

    Lewandowski, Edward F.; Anderson, Petrus A.

    1978-01-01

    A portable punch and die jig includes a U-shaped jig of predetermined width having a slot of predetermined width in the base thereof extending completely across the width of the jig adapted to fit over the walls of rectangular tubes and a punch and die assembly disposed in a hole extending through the base of the jig communicating with the slot in the base of the jig for punching a hole in the walls of the rectangular tubes at precisely determined locations.

  20. Die Herz-Lungen-Maschine

    NASA Astrophysics Data System (ADS)

    Krane, Markus; Bauernschmitt, Robert; Lange, Rüdiger

    Das Kapitel der modernen Herzchirurgie mit Einsatz der Herz-Lungen-Maschine am Menschen beginnt am 6. Mai 1953, als J. Gibbon bei einer 18-jährigen Patientin einen angeborenen Defekt in der Vorhofscheidewand verschließt [1]. Mit ersten experimentellen Versuchen zur extrakorporalen Zirkulation begann Gibbon bereits in den 30er Jahren des 20. Jahrhunderts. Die Grundlage für die heute gebräuchliche Rollerpumpe schufen Porter und Bradley mit ihrer "rotary pump“, welche sie 1855 zum Patent anmeldeten. Diese Pumpe wurde von DeBakey und Schmidt modifiziert und entspricht im Wesentlichen noch der heute sich im Routinebetrieb befindlichen Rollerpumpe [2].

  1. Could magnetic resonance provide in vivo histology?

    PubMed Central

    Dominietto, Marco; Rudin, Markus

    2014-01-01

    The diagnosis of a suspected tumor lesion faces two basic problems: detection and identification of the specific type of tumor. Radiological techniques are commonly used for the detection and localization of solid tumors. Prerequisite is a high intrinsic or enhanced contrast between normal and neoplastic tissue. Identification of the tumor type is still based on histological analysis. The result depends critically on the sampling sites, which given the inherent heterogeneity of tumors, constitutes a major limitation. Non-invasive in vivo imaging might overcome this limitation providing comprehensive three-dimensional morphological, physiological, and metabolic information as well as the possibility for longitudinal studies. In this context, magnetic resonance based techniques are quite attractive since offer at the same time high spatial resolution, unique soft tissue contrast, good temporal resolution to study dynamic processes and high chemical specificity. The goal of this paper is to review the role of magnetic resonance techniques in characterizing tumor tissue in vivo both at morphological and physiological levels. The first part of this review covers methods, which provide information on specific aspects of tumor phenotypes, considered as indicators of malignancy. These comprise measurements of the inflammatory status, neo-vascular physiology, acidosis, tumor oxygenation, and metabolism together with tissue morphology. Even if the spatial resolution is not sufficient to characterize the tumor phenotype at a cellular level, this multiparametric information might potentially be used for classification of tumors. The second part discusses mathematical tools, which allow characterizing tissue based on the acquired three-dimensional data set. In particular, methods addressing tumor heterogeneity will be highlighted. Finally, we address the potential and limitation of using MRI as a tool to provide in vivo tissue characterization. PMID:24454320

  2. In vivo virtual intraoperative surgical photoacoustic microscopy

    SciTech Connect

    Han, Seunghoon Kim, Sehui Kim, Jeehyun E-mail: chulhong@postech.edu; Lee, Changho Jeon, Mansik; Kim, Chulhong E-mail: chulhong@postech.edu

    2013-11-11

    We developed a virtual intraoperative surgical photoacoustic microscopy system by combining with a commercial surgical microscope and photoacoustic microscope (PAM). By sharing the common optical path in the microscope and PAM system, we could acquire the PAM and microscope images simultaneously. Moreover, by employing a beam projector to back-project 2D PAM images onto the microscope view plane as augmented reality, the conventional microscopic and 2D cross-sectional PAM images are concurrently mapped on the plane via an ocular lens of the microscope in real-time. Further, we guided needle insertion into phantom ex vivo and mice skins in vivo.

  3. In vivo toxicity study of Lantana camara

    PubMed Central

    Pour, Badakhshan Mahdi; Sasidharan, Sreenivasan

    2011-01-01

    Objective To investigate the toxicity of methanol extract of various parts (Root, Stem, Leaf, Flower and Fruit) of Lantana camara (L. Camara) in Artemia salina. Methods The methanol extracts of L. camara were tested for in vivo brine shrimp lethality assay. Results All the tested extract exhibited very low toxicity on brine shrimp larva. The results showed that the root extract was the most toxic part of L. camara and may have potential as anticancer agent. Conclusions Methanolic extract of L. camara is relatively safe on short-term exposure. PMID:23569765

  4. In vivo virtual intraoperative surgical photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Han, Seunghoon; Lee, Changho; Kim, Sehui; Jeon, Mansik; Kim, Jeehyun; Kim, Chulhong

    2013-11-01

    We developed a virtual intraoperative surgical photoacoustic microscopy system by combining with a commercial surgical microscope and photoacoustic microscope (PAM). By sharing the common optical path in the microscope and PAM system, we could acquire the PAM and microscope images simultaneously. Moreover, by employing a beam projector to back-project 2D PAM images onto the microscope view plane as augmented reality, the conventional microscopic and 2D cross-sectional PAM images are concurrently mapped on the plane via an ocular lens of the microscope in real-time. Further, we guided needle insertion into phantom ex vivo and mice skins in vivo.

  5. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-06-15

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  6. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-01-01

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium. PMID:26083036

  7. Audio frequency in vivo optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Adie, Steven G.; Kennedy, Brendan F.; Armstrong, Julian J.; Alexandrov, Sergey A.; Sampson, David D.

    2009-05-01

    We present a new approach to optical coherence elastography (OCE), which probes the local elastic properties of tissue by using optical coherence tomography to measure the effect of an applied stimulus in the audio frequency range. We describe the approach, based on analysis of the Bessel frequency spectrum of the interferometric signal detected from scatterers undergoing periodic motion in response to an applied stimulus. We present quantitative results of sub-micron excitation at 820 Hz in a layered phantom and the first such measurements in human skin in vivo.

  8. Simultaneous in vivo phenotyping of CYP enzymes.

    PubMed

    Ghassabian, Sussan; Murray, Michael

    2013-01-01

    As major determinants of the duration of drug action the CYP enzymes strongly influence drug efficacy and toxicity. In vivo phenotyping for CYP activities using cocktails of well-tolerated CYP-specific substrates may be valuable in the development of personalized medicine protocols, particularly for drugs that have significant toxicity profiles. However, the use of the cocktail approach in the clinic is dependent on the rapid provision of patient-specific information to the clinician. Here we describe the application of liquid chromatography-tandem mass spectrometry (LC-MS-MS) for the simultaneous phenotyping of five major drug-metabolizing CYPs in patients within a 5-min assay.

  9. A good way to die.

    PubMed

    Trueland, Jennifer

    2016-03-23

    An end of life care service is providing joined-up care for patients. Care co-ordinators arrange packages of care so patients can die in the place of their choice – often at home. The result is high satisfaction rates among patients, families and staff.

  10. Attitudes on Death and Dying.

    ERIC Educational Resources Information Center

    Andrus, Charles E.

    This paper explored attitudes toward death and dying revealed through interviews with members of the clergy, the medical profession, funeral directors, nursing home residents, and selected others. The sampling was small and results are not intended to be representative of the groups to which these people belong. Rather, the study may be used as a…

  11. Robert Merton Dies at 92

    ERIC Educational Resources Information Center

    Snell, Joel C.

    2006-01-01

    This article features Robert Merton, who died recently at age 92. Merton came into this world as a Jewish baby named Meyer Schkolnick. He lived in South Philly where his parents wrenched a living as blue-collar workers. Merton chose an Anglicized name to move into the Yankee dominated America of the 20's and 30's. At Harvard, he studied under…

  12. Intracranial nonthermal irreversible electroporation: in vivo analysis.

    PubMed

    Garcia, Paulo A; Rossmeisl, John H; Neal, Robert E; Ellis, Thomas L; Olson, John D; Henao-Guerrero, Natalia; Robertson, John; Davalos, Rafael V

    2010-07-01

    Nonthermal irreversible electroporation (NTIRE) is a new minimally invasive technique to treat cancer. It is unique because of its nonthermal mechanism of tumor ablation. Intracranial NTIRE procedures involve placing electrodes into the targeted area of the brain and delivering a series of short but intense electric pulses. The electric pulses induce irreversible structural changes in cell membranes, leading to cell death. We correlated NTIRE lesion volumes in normal brain tissue with electric field distributions from comprehensive numerical models. The electrical conductivity of brain tissue was extrapolated from the measured in vivo data and the numerical models. Using this, we present results on the electric field threshold necessary to induce NTIRE lesions (495-510 V/cm) in canine brain tissue using 90 50-mus pulses at 4 Hz. Furthermore, this preliminary study provides some of the necessary numerical tools for using NTIRE as a brain cancer treatment. We also computed the electrical conductivity of brain tissue from the in vivo data (0.12-0.30 S/m) and provide guidelines for treatment planning and execution. Knowledge of the dynamic electrical conductivity of the tissue and electric field that correlates to lesion volume is crucial to ensure predictable complete NTIRE treatment while minimizing damage to surrounding healthy tissue. PMID:20668843

  13. In vivo orthodontic retainer survival - a review

    PubMed Central

    LABUNET, ANCA VICTORIA; BADEA, MÎNDRA

    2015-01-01

    Background Relapse following orthodontic treatment is a constant concern of orthodontists. Fixed retention is preferred especially for the lower arch by most orthodontists. Objectives This review focuses on in vivo studies. The main objective is to determine the survival rates of different types of retainer: glass-fiber reinforced composite resin, polyethylene or multistrand stainless steel wire bonded to each tooth from canine to canine in the mandibular arch. A second objective is to assess which of these types is less likely to cause additional problems and the third objective is to evaluate the factors that may influence retainer survival. Results and conclusions There were 8 studies identified that matched the objectives stated. Current in vivo studies on survival rate take little notice of the role of the material used for bonding of the fixed retainer. It is not possible to draw a conclusion on reliability of new types of retainers glass fiber reinforced composite resin or polyethylene compared to multistrand stainless steel wire. The multistrand wire remains the gold standard for fixed retention. Although it is a logical outcome that retainer survival is dependent on the application technique, there seems to be no research outcome proving that operator experience, moisture control are essential, nor does patient age or sex have statistically proven effects on survival rates. Adequate studies that involve such aspects should be performed. PMID:26609260

  14. Methods of assessment of thrombosis in vivo

    SciTech Connect

    Dewanjee, M.K.

    1987-01-01

    The contributions of platelets and clotting factors in thrombosis on injured vessel and cardiovascular prostheses have been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and humans with /sup 111/In-labeled platelets, /sup 123/I- and /sup 131/I-labeled fibrinogen, /sup 111/In-labeled antibody to the fibrinogen receptor on the platelet membrane and to fibrin. Thrombus localization by imaging was possible for large thrombus in vessel with deep injury of thrombogenic surface in the acute phase. A single layer of adherent platelets could not be imaged, due to the high background radioactivity present in blood. Thrombogenicity of grafts was compared with that of contralateral vessel. The dynamic process of platelet deposition could be followed accurately using the in vivo imaging technique. In addition, in vitro quantification permits determination of platelet and fibrin density and of the number of fibrin monomers per platelet in thrombus. The roles of prostacyclin, thromboxane inhibitors, and nonsteroidal antiinflammatory drugs have also been evaluated in animals models and humans. The tracer techniques thus provide invaluable information about platelet-fibrin deposition, its organization and dissolution, and for development of less thrombogenic surfaces for use in cardiovascular prostheses. 53 references.

  15. Nutritional abrogation of photoimmunosuppression: in vivo investigations.

    PubMed

    Pilkington, Suzanne M; Gibbs, Neil K; Friedmann, Peter S; Rhodes, Lesley E

    2014-01-01

    Skin cancer is a major public health concern, and the primary aetiological factor in the majority of skin cancers is ultraviolet radiation (UVR) exposure. UVR not only induces potentially mutagenic DNA damage but also suppresses cell-mediated immunity (CMI), allowing cancerous cells to escape destruction and progress to tumours. A considerable proportion of an individual's annual sun exposure is obtained outside the vacation period when topical and physical measures for photoprotection are irregularly used. Certain nutrients could provide an adjunctive protective role, and evidence is accruing from experimental studies to support their use in abrogation of photoimmunosuppression. Moreover, developments in clinical research methods to evaluate impact of solar-simulated radiation on cutaneous CMI allow the immune protective potential of nutritional agents to be examined in humans in vivo. This article summarises the mediation of CMI and its suppression by UVR, evaluates the methodology for quantitative assessment in vivo, reviews the human studies reported on nutritional abrogation of photoimmunosuppression including recent randomized controlled trials and discusses the mechanisms of photoprotection by the nutrients. This includes, in addition to antioxidants, novel studies of omega-3 polyunsaturated fatty acids and nicotinamide. PMID:24283330

  16. Towards Quantitative Phosphotyrosine Profiling In Vivo

    PubMed Central

    Johnson, Hannah; White, Forest M.

    2012-01-01

    Tyrosine phosphorylation is a dynamic reversible post-translational modification that regulates many aspects of cell biology. To understand how this modification controls biological function, it is necessary to not only identify the specific sites of phosphorylation, but also to quantify how phosphorylation levels on these sites may be altered under specific physiological conditions. Due to its sensitivity and accuracy, mass spectrometry (MS) has widely been applied to the identification and characterization of phosphotyrosine signaling across biological systems. In this review we highlight the advances in both MS and phosphotyrosine enrichment methods that have been developed to enable the identification of low level tyrosine phosphorylation events. Computational and manual approaches to ensure confident identification of phosphopeptide sequence and determination of phosphorylation site localization are discussed along with methods that have been applied to the relative quantification of large numbers of phosphorylation sites. Finally, we provide an overview of the challenges ahead as we extend these technologies to the characterization of tyrosine phosphorylation signaling in vivo. With these latest developments in analytical and computational techniques, it is now possible to derive biological insight from quantitative MS-based analysis of signaling networks in vitro and in vivo. Application of these approaches to a wide variety of biological systems will define how signal transduction regulates cellular physiology in health and disease. PMID:22677333

  17. Quantitative profiling of initiating ribosomes in vivo.

    PubMed

    Gao, Xiangwei; Wan, Ji; Liu, Botao; Ma, Ming; Shen, Ben; Qian, Shu-Bing

    2015-02-01

    Cells have evolved exquisite mechanisms to fine-tune the rate of protein synthesis in response to stress. Systemic mapping of start-codon positions and precise measurement of the corresponding initiation rate would transform our understanding of translational control. Here we present quantitative translation initiation sequencing (QTI-seq), with which the initiating ribosomes can be profiled in real time at single-nucleotide resolution. Resultant initiation maps not only delineated variations of start-codon selection but also highlighted a dynamic range of initiation rates in response to nutrient starvation. The integrated data set provided unique insights into principles of alternative translation and mechanisms controlling different aspects of translation initiation. With RiboTag mice, QTI-seq permitted tissue-specific profiling of initiating ribosomes in vivo. Liver cell-specific ribosome profiling uncovered a robust translational reprogramming of the proteasome system in fasted mice. Our findings illuminated the prevalence and dynamic nature of translational regulation pivotal to physiological adaptation in vivo.

  18. Nutritional abrogation of photoimmunosuppression: in vivo investigations.

    PubMed

    Pilkington, Suzanne M; Gibbs, Neil K; Friedmann, Peter S; Rhodes, Lesley E

    2014-01-01

    Skin cancer is a major public health concern, and the primary aetiological factor in the majority of skin cancers is ultraviolet radiation (UVR) exposure. UVR not only induces potentially mutagenic DNA damage but also suppresses cell-mediated immunity (CMI), allowing cancerous cells to escape destruction and progress to tumours. A considerable proportion of an individual's annual sun exposure is obtained outside the vacation period when topical and physical measures for photoprotection are irregularly used. Certain nutrients could provide an adjunctive protective role, and evidence is accruing from experimental studies to support their use in abrogation of photoimmunosuppression. Moreover, developments in clinical research methods to evaluate impact of solar-simulated radiation on cutaneous CMI allow the immune protective potential of nutritional agents to be examined in humans in vivo. This article summarises the mediation of CMI and its suppression by UVR, evaluates the methodology for quantitative assessment in vivo, reviews the human studies reported on nutritional abrogation of photoimmunosuppression including recent randomized controlled trials and discusses the mechanisms of photoprotection by the nutrients. This includes, in addition to antioxidants, novel studies of omega-3 polyunsaturated fatty acids and nicotinamide.

  19. In vivo proton range verification: a review

    NASA Astrophysics Data System (ADS)

    Knopf, Antje-Christin; Lomax, Antony

    2013-08-01

    Protons are an interesting modality for radiotherapy because of their well defined range and favourable depth dose characteristics. On the other hand, these same characteristics lead to added uncertainties in their delivery. This is particularly the case at the distal end of proton dose distributions, where the dose gradient can be extremely steep. In practice however, this gradient is rarely used to spare critical normal tissues due to such worries about its exact position in the patient. Reasons for this uncertainty are inaccuracies and non-uniqueness of the calibration from CT Hounsfield units to proton stopping powers, imaging artefacts (e.g. due to metal implants) and anatomical changes of the patient during treatment. In order to improve the precision of proton therapy therefore, it would be extremely desirable to verify proton range in vivo, either prior to, during, or after therapy. In this review, we describe and compare state-of-the art in vivo proton range verification methods currently being proposed, developed or clinically implemented.

  20. In vivo tractography of fetal association fibers.

    PubMed

    Mitter, Christian; Prayer, Daniela; Brugger, Peter C; Weber, Michael; Kasprian, Gregor

    2015-01-01

    Association fibers connect different cortical areas within the same hemisphere and constitute an essential anatomical substrate for a diverse range of higher cognitive functions. So far a comprehensive description of the prenatal in vivo morphology of these functionally important pathways is lacking. In the present study, diffusion tensor imaging (DTI) and tractography were used to visualize major association fiber tracts and the fornix in utero in preselected non-motion degraded DTI datasets of 24 living unsedated fetuses between 20 and 34 gestational weeks (GW). The uncinate fasciculus and inferior fronto-occipital fasciculus were depicted as early as 20 GW, while in vivo 3D visualization of the inferior longitudinal fasciculus, cingulum and fornix was successful in older fetuses during the third trimester. Provided optimal scanning conditions, in utero DTI and tractography have the potential to provide a more accurate anatomical definition of developing neuronal networks in the human fetal brain. Knowledge about the normal prenatal 3D association tract morphology may serve as reference for their assessment in common developmental diseases. PMID:25742520

  1. In Vivo Bioreactors for Mandibular Reconstruction

    PubMed Central

    Tatara, A.M.; Wong, M.E.; Mikos, A.G.

    2014-01-01

    Large mandibular defects are difficult to reconstruct with good functional and aesthetic outcomes because of the complex geometry of craniofacial bone. While the current gold standard is free tissue flap transfer, this treatment is limited in fidelity by the shape of the harvested tissue and can result in significant donor site morbidity. To address these problems, in vivo bioreactors have been explored as an approach to generate autologous prefabricated tissue flaps. These bioreactors are implanted in an ectopic site in the body, where ossified tissue grows into the bioreactor in predefined geometries and local vessels are recruited to vascularize the developing construct. The prefabricated flap can then be harvested with vessels and transferred to a mandibular defect for optimal reconstruction. The objective of this review article is to introduce the concept of the in vivo bioreactor, describe important preclinical models in the field, summarize the human cases that have been reported through this strategy, and offer future directions for this exciting approach. PMID:25139360

  2. In vivo imaging of zebrafish embryogenesis

    PubMed Central

    Keller, Philipp J.

    2013-01-01

    The zebrafish Danio rerio has emerged as a powerful vertebrate model system that lends itself particularly well to quantitative investigations with live imaging approaches, owing to its exceptionally high optical clarity in embryonic and larval stages. Recent advances in light microscopy technology enable comprehensive analyses of cellular dynamics during zebrafish embryonic development, systematic mapping of gene expression dynamics, quantitative reconstruction of mutant phenotypes and the system-level biophysical study of morphogenesis. Despite these technical breakthroughs, it remains challenging to design and implement experiments for in vivo long-term imaging at high spatio-temporal resolution. This article discusses the fundamental challenges in zebrafish long-term live imaging, provides experimental protocols and highlights key prop1erties and capabilities of advanced fluorescence microscopes. The article focuses in particular on experimental assays based on light sheet-based fluorescence microscopy, an emerging imaging technology that achieves exceptionally high imaging speeds and excellent signal-to-noise ratios, while minimizing light-induced damage to the specimen. This unique combination of capabilities makes light sheet microscopy an indispensable tool for the in vivo long-term imaging of large developing organisms. PMID:23523701

  3. Aggregation states of phosphoribulokinase (PRK) in vivo

    SciTech Connect

    Porter, M.A.; Hartman, F.C. )

    1989-04-01

    Spinach PRK, extracted from either light- or dark-harvested tissue (LHT or DHT) in the presence of DTT, has a M{sub r} of 90 kDa and is fully active. Consistent with an earlier study extraction of LHT in the absence of DTT results in two forms of inactive PRK, M{sub r} 90 kDa (LMW) and M{sub r}> 550 kDa (HMW). If 400 mM (NH{sub 4}){sub 2}SO{sub 4} without DTT is included during extraction, the active LMW predominates implicating it as the major, functional form in vivo during periods of illumination. Either high- or low-sale extraction of DHT reveals mostly HMW; prolonged incubation of the high-salt extract causes disaggregation of LMW without activation. These data suggest that the dark form of PRK in vivo is an aggregate, formed by either self-association or by interactions with other proteins. Salt-induced disaggregation of HMW is inconsistent with intermolecular disulfides crosslinking the aggregated PRK; therefore, oxidation-induced conformational changes must promote aggregation.

  4. Multidimensional In Vivo Hazard Assessment Using Zebrafish

    PubMed Central

    Tanguay, Robert L.

    2014-01-01

    There are tens of thousands of man-made chemicals in the environment; the inherent safety of most of these chemicals is not known. Relevant biological platforms and new computational tools are needed to prioritize testing of chemicals with limited human health hazard information. We describe an experimental design for high-throughput characterization of multidimensional in vivo effects with the power to evaluate trends relating to commonly cited chemical predictors. We evaluated all 1060 unique U.S. EPA ToxCast phase 1 and 2 compounds using the embryonic zebrafish and found that 487 induced significant adverse biological responses. The utilization of 18 simultaneously measured endpoints means that the entire system serves as a robust biological sensor for chemical hazard. The experimental design enabled us to describe global patterns of variation across tested compounds, evaluate the concordance of the available in vitro and in vivo phase 1 data with this study, highlight specific mechanisms/value-added/novel biology related to notochord development, and demonstrate that the developmental zebrafish detects adverse responses that would be missed by less comprehensive testing strategies. PMID:24136191

  5. NANOSTRUCTURED PROBES FOR IN VIVO GENE DETECTION

    PubMed Central

    Bao, Gang; Santangelo, Phillip; Nitin, Nitin; Rhee, Won Jong

    2010-01-01

    The ability to visualize in real-time the expression dynamics and localization of specific RNAs in vivo offers tremendous opportunities for biological and disease studies including cancer detection. However, quantitative methods such as real-time PCR and DNA microarrays rely on the use of cell lysates thus not able to obtain important spatial and temporal information. Fluorescence proteins and other reporter systems cannot image endogenous RNA in living cells. Fluorescence in situ hybridization (FISH) assays require washing to achieve specificity, therefore can only be used with fixed cells. Here we review the recent development of nanostructured probes for living cell RNA detection, and discuss the biological and engineering issues and challenges of quantifying gene expression in vivo. In particular, we describe methods that use oligonucleotide probes, combined with novel delivery strategies, to image the relative level, localization and dynamics of RNA in live cells. Examples of detecting endogenous mRNAs, as well as imaging their subcellular localization are given to illustrate the biological applications, and issues in probe design, delivery and target accessibility are discussed. The nanostructured probes promise to open new and exciting opportunities in sensitive gene detection for a wide range of biological and medical applications. PMID:22138717

  6. The thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The effects of welding, five selected surface coatings, and stress relieving on the thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies were studied using eleven thermal fatigue specimens. Stress relieving was conducted after each 5,000 cycle interval at 1050 F for three hours. Four thermal fatigue specimens were welded with H-13 or maraging steel welding rods at ambient and elevated temperatures and subsequently, subjected to different post-weld heat treatments. Crack patterns were examined at 5,000, 10,000, and 15,000 cycles. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. The results indicate that a significant improvement in thermal fatigue resistance over the control was obtained from the stress-relieving treatment. Small improvements were obtained from the H-13 welded specimens and from a salt bath nitrogen and carbon-surface treatment. The other surface treatments and welded specimens either did not affect or had a detrimental influence on the thermal fatigue properties of the H-13 die steel.

  7. A new in vivo replica technique for scanning electron microscope study of dental plaque morphology.

    PubMed

    Lambrechts, P; van Steenberghe, D; Vanherle, G

    1982-05-01

    For the micro-morphological investigation of soft oral tissues and deposits on the teeth in vivo, the use of an accurate replica technique is essential if the object under study cannot be examined directly. The conventional replica techniques based on resin or elastomer positive dies, have some limitations due to the instability of the sample die in the scanning electron microscope (S.E.M) conditions and artifacts induced at higher magnifications. Therefore, a new replica technique has been developed using a low viscosity impression material that is subsequently copperplated and poured with synthetic plaster. This offers a stable metal positive die suitable for direct examination in the S.E.M. without prior gold evaporation. Higher magnifications (greater than 7500) are easily obtained without the danger of artifacts. Reproduction of details is of a high order, and the reproduction ability depends only on the accuracy of the first impression. This technique offers new possibilities of discerning fine changes in surface detail in longitudinal clinical investigations.

  8. Modeling Melanoma In Vitro and In Vivo

    PubMed Central

    Beaumont, Kimberley A.; Mohana-Kumaran, Nethia; Haass, Nikolas K.

    2013-01-01

    The behavior of melanoma cells has traditionally been studied in vitro in two-dimensional cell culture with cells adhering to plastic dishes. However, in order to mimic the three-dimensional architecture of a melanoma, as well as its interactions with the tumor microenvironment, there has been the need for more physiologically relevant models. This has been achieved by designing 3D in vitro models of melanoma, such as melanoma spheroids embedded in extracellular matrix or organotypic skin reconstructs. In vivo melanoma models have typically relied on the growth of tumor xenografts in immunocompromised mice. Several genetically engineered mouse models have now been developed which allow the generation of spontaneous melanoma. Melanoma models have also been established in other species such as zebrafish, which are more conducive to imaging and high throughput studies. We will discuss these models as well as novel techniques that are relevant to the study of the molecular mechanisms underlying melanoma progression. PMID:27429258

  9. New tools for in vivo fluorescence tagging.

    PubMed

    Chapman, Sean; Oparka, Karl J; Roberts, Alison G

    2005-12-01

    Engineering of fluorescent proteins continues to produce new tools for in vivo studies. The current selection contains brighter, monomeric, spectral variants that will facilitate multiplex imaging and FRET, and a collection of optical highlighter proteins that might replace photoactivatable-GFP. These new highlighter proteins, which include proteins that have photoswitchable fluorescence characteristics and a protein whose fluorescence can be repeatedly turned on and off, should simplify refined analyses of protein dynamics and kinetics. Fluorescent protein-based systems have also been developed to allow facile detection of protein-protein interactions in planta. In addition, new tags in the form of peptides that bind fluorescent ligands and quantum dots offer the prospect of overcoming some of the limitations of fluorescent proteins such as excessive size and insufficient brightness.

  10. THz Medical Imaging: in vivo Hydration Sensing

    PubMed Central

    Taylor, Zachary D.; Singh, Rahul S.; Bennett, David B.; Tewari, Priyamvada; Kealey, Colin P.; Bajwa, Neha; Culjat, Martin O.; Stojadinovic, Alexander; Lee, Hua; Hubschman, Jean-Pierre; Brown, Elliott R.; Grundfest, Warren S.

    2015-01-01

    The application of THz to medical imaging is experiencing a surge in both interest and federal funding. A brief overview of the field is provided along with promising and emerging applications and ongoing research. THz imaging phenomenology is discussed and tradeoffs are identified. A THz medical imaging system, operating at ~525 GHz center frequency with ~125 GHz of response normalized bandwidth is introduced and details regarding principles of operation are provided. Two promising medical applications of THz imaging are presented: skin burns and cornea. For burns, images of second degree, partial thickness burns were obtained in rat models in vivo over an 8 hour period. These images clearly show the formation and progression of edema in and around the burn wound area. For cornea, experimental data measuring the hydration of ex vivo porcine cornea under drying is presented demonstrating utility in ophthalmologic applications. PMID:26085958

  11. Nucleosome dynamics during chromatin remodeling in vivo

    PubMed Central

    Ramachandran, Srinivas; Henikoff, Steven

    2016-01-01

    ABSTRACT Precise positioning of nucleosomes around regulatory sites is achieved by the action of chromatin remodelers, which use the energy of ATP to slide, evict or change the composition of nucleosomes. Chromatin remodelers act to bind nucleosomes, disrupt histone-DNA interactions and translocate the DNA around the histone core to reposition nucleosomes. Hence, remodeling is expected to involve nucleosomal intermediates with a structural organization that is distinct from intact nucleosomes. We describe the identification of a partially unwrapped nucleosome structure using methods that map histone-DNA contacts genome-wide. This alternative nucleosome structure is likely formed as an intermediate or by-product during nucleosome remodeling by the RSC complex. Identification of the loss of histone-DNA contacts during chromatin remodeling by RSC in vivo has implications for the regulation of transcriptional initiation. PMID:26933790

  12. Seeing Stem Cells at Work In Vivo

    PubMed Central

    Srivastava, Amit K.; Bulte, Jeff W. M.

    2013-01-01

    Stem cell based-therapies are novel therapeutic strategies that hold key for developing new treatments for diseases conditions with very few or no cures. Although there has been an increase in the number of clinical trials involving stem cell-based therapies in the last few years, the long-term risks and benefits of these therapies are still unknown. Detailed in vivo studies are needed to monitor the fate of transplanted cells, including their distribution, differentiation, and longevity over time. Advancements in non-invasive cellular imaging techniques to track engrafted cells in real-time present a powerful tool for determining the efficacy of stem cell-based therapies. In this review, we describe the latest approaches to stem cell labeling and tracking using different imaging modalities. PMID:23975604

  13. Quantifying drug-protein binding in vivo.

    SciTech Connect

    Buchholz, B; Bench, G; Keating III, G; Palmblad, M; Vogel, J; Grant, P G; Hillegonds, D

    2004-02-17

    Accelerator mass spectrometry (AMS) provides precise quantitation of isotope labeled compounds that are bound to biological macromolecules such as DNA or proteins. The sensitivity is high enough to allow for sub-pharmacological (''micro-'') dosing to determine macromolecular targets without inducing toxicities or altering the system under study, whether it is healthy or diseased. We demonstrated an application of AMS in quantifying the physiologic effects of one dosed chemical compound upon the binding level of another compound in vivo at sub-toxic doses [4].We are using tissues left from this study to develop protocols for quantifying specific binding to isolated and identified proteins. We also developed a new technique to quantify nanogram to milligram amounts of isolated protein at precisions that are comparable to those for quantifying the bound compound by AMS.

  14. In Vivo Imaging of Cancer in Zebrafish.

    PubMed

    Ignatius, Myron S; Hayes, Madeline; Langenau, David M

    2016-01-01

    Zebrafish cancer models have greatly advanced our understanding of malignancy in humans. This is made possible due to the unique advantages of the zebrafish model including ex vivo development and large clutch sizes, which enable large-scale genetic and chemical screens. Transparency of the embryo and the creation of adult zebrafish devoid of pigmentation (casper) have permitted unprecedented ability to dynamically visualize cancer progression in live animals. When coupled with fluorescent reporters and transgenic approaches that drive oncogenesis, it is now possible to label entire or subpopulations of cancer cells and follow cancer growth in near real-time. Here, we will highlight aspects of in vivo imaging using the zebrafish and how it has enhanced our understanding of the fundamental aspects of tumor initiation, self-renewal, neovascularization, tumor cell heterogeneity, invasion and metastasis. Importantly, we will highlight the contribution of cancer imaging in zebrafish for drug discovery. PMID:27165356

  15. Codon-specific missense errors in vivo.

    PubMed

    Bouadloun, F; Donner, D; Kurland, C G

    1983-01-01

    We have developed a simple method for measuring the missense substitution of amino acids at specified positions in proteins synthesized in vivo. We find that the frequency of cysteine substitution for the single arginine in Escherichia coli ribosomal protein L7/L12 is close to 10(-3) for wild-type bacteria, decreases to 4 x 10(-4) in streptomycin-resistant bacteria containing mutant S12 (rpsL), and is virtually unchanged in Ram bacteria containing mutant S4 (rpsD). We have also found that the frequency of the cysteine substitution for the single tryptophan in E. coli ribosomal protein S6 is 3-4 x 10(-3) for wild-type bacteria, decreases to 6 x 10(-4) in streptomycin-resistant bacteria and is elevated to nearly 10(-2) in Ram bacteria.

  16. In vivo cytogenetic studies on aspartame.

    PubMed

    Alsuhaibani, Entissar S

    2010-01-01

    Aspartame (a-Laspartyl-L-phenylalanine 1-methylester) is a dipeptide low-calorie artificial sweetener that is widely used as a nonnutritive sweetener in foods and drinks. The safety of aspartame and its metabolic breakdown products (phenylalanine, aspartic acid and methanol) was investigated in vivo using chromosomal aberration (CA) test and sister chromatid exchange (SCE) test in the bone marrow cells of mice. Swiss Albino male mice were exposed to aspartame (3.5, 35, 350 mg/kg body weight). Bone marrow cells isolated from femora were analyzed for chromosome aberrations and sister chromatid exchanges. Treatment with aspartame induced dose dependently chromosome aberrations at all concentrations while it did not induce sister chromatid exchanges. On the other hand, aspartame did not decrease the mitotic index (MI). However, statistical analysis of the results show that aspartame is not significantly genotoxic at low concentration.

  17. In vivo Raman spectroscopy of cervix cancers

    NASA Astrophysics Data System (ADS)

    Rubina, S.; Sathe, Priyanka; Dora, Tapas Kumar; Chopra, Supriya; Maheshwari, Amita; Krishna, C. Murali

    2014-03-01

    Cervix-cancer is the third most common female cancer worldwide. It is the leading cancer among Indian females with more than million new diagnosed cases and 50% mortality, annually. The high mortality rates can be attributed to late diagnosis. Efficacy of Raman spectroscopy in classification of normal and pathological conditions in cervix cancers on diverse populations has already been demonstrated. Our earlier ex vivo studies have shown the feasibility of classifying normal and cancer cervix tissues as well as responders/non-responders to Concurrent chemoradiotherapy (CCRT). The present study was carried out to explore feasibility of in vivo Raman spectroscopic methods in classifying normal and cancerous conditions in Indian population. A total of 182 normal and 132 tumor in vivo Raman spectra, from 63 subjects, were recorded using a fiberoptic probe coupled HE-785 spectrometer, under clinical supervision. Spectra were acquired for 5 s and averaged over 3 times at 80 mW laser power. Spectra of normal conditions suggest strong collagenous features and abundance of non-collagenous proteins and DNA in case of tumors. Preprocessed spectra were subjected to Principal Component-Linear Discrimination Analysis (PCLDA) followed by leave-one-out-cross-validation. Classification efficiency of ~96.7% and 100% for normal and cancerous conditions respectively, were observed. Findings of the study corroborates earlier studies and suggest applicability of Raman spectroscopic methods in combination with appropriate multivariate tool for objective, noninvasive and rapid diagnosis of cervical cancers in Indian population. In view of encouraging results, extensive validation studies will be undertaken to confirm the findings.

  18. In vivo determination of bone blood flow

    SciTech Connect

    Rosenthal, M.S.; De Luca, P.M. Jr.; Pearson, D.W.; Nickles, R.J.

    1984-01-01

    Quantitative measurement of bone blood flow is vital to understand the hemodynamics of bone systems especially in the study of asceptic bone necroses. These ''silent bends'' result from micro-emboli in femoral arterioles from small nitrogen bubbles released from lipids during a diver's ascent. A technique to determine bone blood flow in vivo has been developed by measuring the rate of inert gas washout of Ar-41 (t /sub 1/2/ = 1.83 h, E = 1293 keV) from the bone mineral matrix. Argon gas is formed in vivo by neutron activation of Ca-44 using 14.3 MeV neutrons, following the reaction Ca-44(n, ..cap alpha..)Ar-41. The blood flow in the irradiated bone is determined by measuring the clearance rate of Ar-41 using gamma-ray spectroscopy. To date, measurements have been made on dead and living rats (weight 300g). The results indicated that in the no-flow situation the clearance rate is consistent with the physical half-life of Ar-41, while for the live rats the clearance rate for argon is dependent on the flow of blood in the bone. The observed clearance times correspond to flows greater than 3 ml of blood per 100 ml of argon distribution volume/min (F/pV), with the bone-blood partition coefficient for argon approximately one. In addition, measurements of the partitioning of argon and other gases with bone have been measured in order to understand blood-bone systems more fully.

  19. 3D ultrafast ultrasound imaging in vivo.

    PubMed

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability.

  20. 3D ultrafast ultrasound imaging in vivo

    NASA Astrophysics Data System (ADS)

    Provost, Jean; Papadacci, Clement; Esteban Arango, Juan; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra—and inter-observer variability.

  1. 3D ultrafast ultrasound imaging in vivo.

    PubMed

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability. PMID:25207828

  2. In Vivo Dedifferentiation of Adult Adipose Cells

    PubMed Central

    Lu, Feng; Dong, Ziqing; Chang, Qiang; Gao, Jianhua

    2015-01-01

    Introduction Adipocytes can dedifferentiate into fibroblast-like cells in vitro and thereby acquire proliferation and multipotent capacities to participate in the repair of various organs and tissues. Whether dedifferentiation occurs under physiological or pathological conditions in vivo is unknown. Methods A tissue expander was placed under the inguinal fat pads of rats and gradually expanded by injection of water. Samples were collected at various time points, and morphological, histological, cytological, ultrastructural, and gene expression analyses were conducted. In a separate experiment, purified green fluorescent protein+ adipocytes were transplanted into C57 mice and collected at various time points. The transplanted adipocytes were assessed by bioluminescence imaging and whole-mount staining. Results The expanded fat pad was obviously thinner than the untreated fat pad on the opposite side. It was also tougher in texture and with more blood vessels attached. Hematoxylin and eosin staining and transmission electron microscopy indicated there were fewer monolocular adipocytes in the expanded fat pad and the morphology of these cells was altered, most notably their lipid content was discarded. Immunohistochemistry showed that the expanded fat pad contained an increased number of proliferative cells, which may have been derived from adipocytes. Following removal of the tissue expander, many small adipocytes were observed. Bioluminescence imaging suggested that some adipocytes survived when transplanted into an ischemic-hypoxic environment. Whole-mount staining revealed that surviving adipocytes underwent a process similar to adipocyte dedifferentiation in vitro. Monolocular adipocytes became multilocular adipocytes and then fibroblast-like cells. Conclusions Mature adipocytes may be able to dedifferentiate in vivo, and this may be an adipose tissue self-repair mechanism. The capacity of adipocytes to dedifferentiate into stem cell-like cells may also have a

  3. 3D Ultrafast Ultrasound Imaging In Vivo

    PubMed Central

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-01-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative real-time imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in three dimensions based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32×32 matrix-array probe. Its capability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3-D Shear-Wave Imaging, 3-D Ultrafast Doppler Imaging and finally 3D Ultrafast combined Tissue and Flow Doppler. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3-D Ultrafast Doppler was used to obtain 3-D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, for the first time, the complex 3-D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, and the 3-D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3-D Ultrafast Ultrasound Imaging for the 3-D real-time mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra- and inter-observer variability. PMID:25207828

  4. Mesenchymal stem cells show radioresistance in vivo

    PubMed Central

    Singh, Sarvpreet; Kloss, Frank R; Brunauer, Regina; Schimke, Magdalena; Jamnig, Angelika; Greiderer-Kleinlercher, Brigitte; Klima, Günter; Rentenberger, Julia; Auberger, Thomas; Hächl, Oliver; Rasse, Michael; Gassner, Robert; Lepperdinger, Günter

    2012-01-01

    Abstract Irradiation impacts on the viability and differentiation capacity of tissue-borne mesenchymal stem cells (MSC), which play a pivotal role in bone regeneration. As a consequence of radiotherapy, bones may develop osteoradionecrosis. When irradiating human bone-derived MSC in vitro with increasing doses, the cells’ self-renewal capabilities were greatly reduced. Mitotically stalled cells were still capable of differentiating into osteoblasts and pre-adipocytes. As a large animal model comparable to the clinical situation, pig mandibles were subjected to fractionized radiation of 2 χ 9 Gy within 1 week. This treatment mimics that of a standardized clinical treatment regimen of head and neck cancer patients irradiated 30 χ 2 Gy. In the pig model, fractures which had been irradiated, showed delayed osseous healing. When isolating MSC at different time points post-irradiation, no significant changes regarding proliferation capacity and osteogenic differentiation potential became apparent. Therefore, pig mandibles were irradiated with a single dose of either 9 or 18 Gy in vivo, and MSC were isolated immediately afterwards. No significant differences between the untreated and 9 Gy irradiated bone with respect to proliferation and osteogenic differentiation were unveiled. Yet, cells isolated from 18 Gy irradiated specimens exhibited a reduced osteogenic differentiation capacity, and during the first 2 weeks proliferation rates were greatly diminished. Thereafter, cells recovered and showed normal proliferation behaviour. These findings imply that MSC can effectively cope with irradiation up to high doses in vivo. This finding should thus be implemented in future therapeutic concepts to protect regenerating tissue from radiation consequences. PMID:21762375

  5. Dimerization of visual pigments in vivo.

    PubMed

    Zhang, Tao; Cao, Li-Hui; Kumar, Sandeep; Enemchukwu, Nduka O; Zhang, Ning; Lambert, Alyssia; Zhao, Xuchen; Jones, Alex; Wang, Shixian; Dennis, Emily M; Fnu, Amrita; Ham, Sam; Rainier, Jon; Yau, King-Wai; Fu, Yingbin

    2016-08-01

    It is a deeply engrained notion that the visual pigment rhodopsin signals light as a monomer, even though many G protein-coupled receptors are now known to exist and function as dimers. Nonetheless, recent studies (albeit all in vitro) have suggested that rhodopsin and its chromophore-free apoprotein, R-opsin, may indeed exist as a homodimer in rod disk membranes. Given the overwhelmingly strong historical context, the crucial remaining question, therefore, is whether pigment dimerization truly exists naturally and what function this dimerization may serve. We addressed this question in vivo with a unique mouse line (S-opsin(+)Lrat(-/-)) expressing, transgenically, short-wavelength-sensitive cone opsin (S-opsin) in rods and also lacking chromophore to exploit the fact that cone opsins, but not R-opsin, require chromophore for proper folding and trafficking to the photoreceptor's outer segment. In R-opsin's absence, S-opsin in these transgenic rods without chromophore was mislocalized; in R-opsin's presence, however, S-opsin trafficked normally to the rod outer segment and produced functional S-pigment upon subsequent chromophore restoration. Introducing a competing R-opsin transmembrane helix H1 or helix H8 peptide, but not helix H4 or helix H5 peptide, into these transgenic rods caused mislocalization of R-opsin and S-opsin to the perinuclear endoplasmic reticulum. Importantly, a similar peptide-competition effect was observed even in WT rods. Our work provides convincing evidence for visual pigment dimerization in vivo under physiological conditions and for its role in pigment maturation and targeting. Our work raises new questions regarding a potential mechanistic role of dimerization in rhodopsin signaling. PMID:27462111

  6. [Dying with cancer: Hollywood lessons].

    PubMed

    Niemeyer, Fernanda; Kruse, Maria Henriqueta Luce

    2013-12-01

    The study attempts to understand how dying from cancer is portrayed by five movies produced in Hollywood between 1993 and 2006. Based on the cultural studies and their post-structuralism version and supported by the notions of discourse and subjectivity, as proposed by philosopher Michel Foucault, we suggest one of the possible readings of the movie picture corpus. We assess how the movie picture discourse acts as a cultural pedagogy that produces ways of seeing dying with cancer: immortalizing the healthy body image, silencing death, taking care of the dead body and, finally, accepting death. Our proposal is intended to stimulate reflections that may contribute to care and education in nursing. PMID:25080714

  7. Guide for extrusion dies eliminates straightening operation

    NASA Technical Reports Server (NTRS)

    Gyorgak, C. A.; Hoover, R. J.

    1964-01-01

    To prevent distortion of extruded metal, a guidance assembly is aligned with the die. As the metal emerges from the extrusion dies, it passes directly into the receiver and straightening tube system, and the completed extrusion is withdrawn.

  8. Killing, letting die and euthanasia.

    PubMed

    Husak, D N

    1979-12-01

    Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible.

  9. Jewish tradition in death and dying.

    PubMed

    Ross, H M

    1998-10-01

    Death is often a spiritually difficult time for the dying and their families. Judaism approaches dying with some unique views that can differ from other religious traditions. Through an understanding of Jewish tradition, nurses can ease the dying process for Jewish patients and their families.

  10. Contoured Orifice for Silicon-Ribbon Die

    NASA Technical Reports Server (NTRS)

    Mackintosh, B. H.

    1985-01-01

    Die configuration encourages purity and stable growth. Contour of die orifice changes near ribbon edges. As result, silicon ribbon has nearly constant width and little carbon contamination. Die part of furnace being developed to produce high-quality, low-cost material for solar cells.

  11. In Vivo Monitoring Program Manual, PNL-MA-574

    SciTech Connect

    Lynch, Timothy P.

    2010-07-01

    An overview of the administration for the In Vivo Monitoring Program (IVMP) for Hanford. This includes organizational structure and program responsibilities; coordination of in vivo measurements; scheduling measurements; performing measurements; reporting results; and quality assurance. Overall responsibility for the management of the IVMP rests with the Program Manager (PM). The PM is responsible for providing the required in vivo counting services for Hanford Site contractor employees in accordance with Department of Energy (DOE) requirements and the specific statements of work.

  12. Passive in vivo elastography from skeletal muscle noise

    SciTech Connect

    Sabra, Karim G.; Conti, Stephane; Roux, Philippe; Kuperman, W. A.

    2007-05-07

    Measuring the in vivo elastic properties of muscles (e.g., stiffness) provides a means for diagnosing and monitoring muscular activity. The authors demonstrated a passive in vivo elastography technique without an active external radiation source. This technique instead uses cross correlations of contracting skeletal muscle noise recorded with skin-mounted sensors. Each passive sensor becomes a virtual in vivo shear wave source. The results point to a low-cost, noninvasive technique for monitoring biomechanical in vivo muscle properties. The efficacy of the passive elastography technique originates from the high density of cross paths between all sensor pairs, potentially achieving the same sensitivity obtained from active elastography methods.

  13. In vivo predictive dissolution: transport analysis of the CO2 , bicarbonate in vivo buffer system.

    PubMed

    Krieg, Brian J; Taghavi, Seyed Mohammad; Amidon, Gordon L; Amidon, Gregory E

    2014-11-01

    Development of an oral in vivo predictive dissolution medium for acid drugs with a pKa in the physiological range (e.g., Biopharmaceutics Classification System Class IIa) requires transport analysis of the complex in vivo CO2 /bicarbonate buffering system. In this report, we analyze this buffer system using hydrodynamically defined rotating disk dissolution. Transport analysis of drug flux was predicted using the film model approach of Mooney et al based on equilibrium assumptions as well as accounting for the slow hydration reaction, CO2 + H2 O → H2 CO3 . The accuracy of the models was compared with experimentally determined results using the rotating disk dissolution of ibuprofen, indomethacin, and ketoprofen. The equilibrium and slow hydration reaction rate models predict significantly different dissolution rates. The experimental results are more accurately predicted by accounting for the slow hydration reaction under a variety of pH and hydrodynamic conditions. Although the complex bicarbonate buffering system requires further consideration given its dynamic nature in vivo, a simplifying irreversible reaction (IRR) transport analysis accurately predicts in vitro rotating disk dissolution rates of several carboxylic acid drugs. This IRR transport model provides further insight into bicarbonate buffer and can be useful in developing more physiologically relevant buffer systems for dissolution testing.

  14. Viral Vectors for in Vivo Gene Transfer

    NASA Astrophysics Data System (ADS)

    Thévenot, E.; Dufour, N.; Déglon, N.

    The transfer of DNA into the nucleus of a eukaryotic cell (gene transfer) is a central theme of modern biology. The transfer is said to be somatic when it refers to non-germline organs of a developed individual, and germline when it concerns gametes or the fertilised egg of an animal, with the aim of transmitting the relevant genetic modification to its descendents [1]. The efficient introduction of genetic material into a somatic or germline cell and the control of its expression over time have led to major advances in understanding how genes work in vivo, i.e., in living organisms (functional genomics), but also to the development of innovative therapeutic methods (gene therapy). The efficiency of gene transfer is conditioned by the vehicle used, called the vector. Desirable features for a vector are as follows: Easy to produce high titer stocks of the vector in a reproducible way. Absence of toxicity related to transduction (transfer of genetic material into the target cell, and its expression there) and no immune reaction of the organism against the vector and/or therapeutic protein. Stability in the expression of the relevant gene over time, and the possibility of regulation, e.g., to control expression of the therapeutic protein on the physiological level, or to end expression at the end of treatment. Transduction of quiescent cells should be as efficient as transduction of dividing cells. Vectors currently used fall into two categories: non-viral and viral vectors. In non-viral vectors, the DNA is complexed with polymers, lipids, or cationic detergents (described in Chap. 3). These vectors have a low risk of toxicity and immune reaction. However, they are less efficient in vivo than viral vectors when it comes to the number of cells transduced and long-term transgene expression. (Naked DNA transfer or electroporation is rather inefficient in the organism. This type of gene transfer will not be discussed here, and the interested reader is referred to the

  15. Synovial tissue hypoxia and inflammation in vivo

    PubMed Central

    Ng, C T; Biniecka, M; Kennedy, A; McCormick, J; FitzGerald, O; Bresnihan, B; Buggy, D; Taylor, C T; O'Sullivan, J; Fearon, U; Veale, D J

    2010-01-01

    Introduction Hypoxia is a microenvironmental feature in the inflamed joint, which promotes survival advantage for cells. The aim of this study was to examine the relationship of partial oxygen pressure in the synovial tissue (tPO2) in patients with inflammatory arthritis with macroscopic/microscopic inflammation and local levels of proinflammatory mediators. Methods Patients with inflammatory arthritis underwent full clinical assessment and video arthroscopy to quantify macroscopic synovitis and measure synovial tPO2 under direct visualisation. Cell specific markers (CD3 (T cells), CD68 (macrophages), Ki67 (cell proliferation) and terminal deoxynucleotidyl transferase dUTP nick end labelling (cell apoptosis)) were quantified by immunohistology. In vitro migration was assessed in primary and normal synoviocytes (synovial fibroblast cells (SFCs)) using a wound repair scratch assay. Levels of tumour necrosis factor α (TNFα), interleukin 1β (IL1β), interferon γ (IFNγ), IL6, macrophage inflammatory protein 3α (MIP3α) and IL8 were quantified, in matched serum and synovial fluid, by multiplex cytokine assay and ELISA. Results The tPO2 was 22.5 (range 3.2–54.1) mm Hg and correlated inversely with macroscopic synovitis (r=−0.421, p=0.02), sublining CD3 cells (−0.611, p<0.01) and sublining CD68 cells (r=−0.615, p<0.001). No relationship with cell proliferation or apoptosis was found. Primary and normal SFCs exposed to 1% and 3% oxygen (reflecting the median tPO2 in vivo) induced cell migration. This was coupled with significantly higher levels of synovial fluid tumour necrosis factor α (TNFα), IL1β, IFNγ and MIP3α in patients with tPO2 <20 mm Hg (all p values <0.05). Conclusions This is the first study to show a direct in vivo correlation between synovial tPO2, inflammation and cell migration, thus it is proposed that hypoxia is a possible primary driver of inflammatory processes in the arthritic joint. PMID:20439288

  16. Noncanonical autophagy inhibits the autoinflammatory, lupus-like response to dying cells.

    PubMed

    Martinez, Jennifer; Cunha, Larissa D; Park, Sunmin; Yang, Mao; Lu, Qun; Orchard, Robert; Li, Quan-Zhen; Yan, Mei; Janke, Laura; Guy, Cliff; Linkermann, Andreas; Virgin, Herbert W; Green, Douglas R

    2016-05-01

    Defects in clearance of dying cells have been proposed to underlie the pathogenesis of systemic lupus erythematosus (SLE). Mice lacking molecules associated with dying cell clearance develop SLE-like disease, and phagocytes from patients with SLE often display defective clearance and increased inflammatory cytokine production when exposed to dying cells in vitro. Previously, we and others described a form of noncanonical autophagy known as LC3-associated phagocytosis (LAP), in which phagosomes containing engulfed particles, including dying cells, recruit elements of the autophagy pathway to facilitate maturation of phagosomes and digestion of their contents. Genome-wide association studies have identified polymorphisms in the Atg5 (ref. 8) and possibly Atg7 (ref. 9) genes, involved in both canonical autophagy and LAP, as markers of a predisposition for SLE. Here we describe the consequences of defective LAP in vivo. Mice lacking any of several components of the LAP pathway show increased serum levels of inflammatory cytokines and autoantibodies, glomerular immune complex deposition, and evidence of kidney damage. When dying cells are injected into LAP-deficient mice, they are engulfed but not efficiently degraded and trigger acute elevation of pro-inflammatory cytokines but not anti-inflammatory interleukin (IL)-10. Repeated injection of dying cells into LAP-deficient, but not LAP-sufficient, mice accelerated the development of SLE-like disease, including increased serum levels of autoantibodies. By contrast, mice deficient in genes required for canonical autophagy but not LAP do not display defective dying cell clearance, inflammatory cytokine production, or SLE-like disease, and, like wild-type mice, produce IL-10 in response to dying cells. Therefore, defects in LAP, rather than canonical autophagy, can cause SLE-like phenomena, and may contribute to the pathogenesis of SLE. PMID:27096368

  17. Noncanonical autophagy inhibits the autoinflammatory, lupus-like response to dying cells.

    PubMed

    Martinez, Jennifer; Cunha, Larissa D; Park, Sunmin; Yang, Mao; Lu, Qun; Orchard, Robert; Li, Quan-Zhen; Yan, Mei; Janke, Laura; Guy, Cliff; Linkermann, Andreas; Virgin, Herbert W; Green, Douglas R

    2016-05-01

    Defects in clearance of dying cells have been proposed to underlie the pathogenesis of systemic lupus erythematosus (SLE). Mice lacking molecules associated with dying cell clearance develop SLE-like disease, and phagocytes from patients with SLE often display defective clearance and increased inflammatory cytokine production when exposed to dying cells in vitro. Previously, we and others described a form of noncanonical autophagy known as LC3-associated phagocytosis (LAP), in which phagosomes containing engulfed particles, including dying cells, recruit elements of the autophagy pathway to facilitate maturation of phagosomes and digestion of their contents. Genome-wide association studies have identified polymorphisms in the Atg5 (ref. 8) and possibly Atg7 (ref. 9) genes, involved in both canonical autophagy and LAP, as markers of a predisposition for SLE. Here we describe the consequences of defective LAP in vivo. Mice lacking any of several components of the LAP pathway show increased serum levels of inflammatory cytokines and autoantibodies, glomerular immune complex deposition, and evidence of kidney damage. When dying cells are injected into LAP-deficient mice, they are engulfed but not efficiently degraded and trigger acute elevation of pro-inflammatory cytokines but not anti-inflammatory interleukin (IL)-10. Repeated injection of dying cells into LAP-deficient, but not LAP-sufficient, mice accelerated the development of SLE-like disease, including increased serum levels of autoantibodies. By contrast, mice deficient in genes required for canonical autophagy but not LAP do not display defective dying cell clearance, inflammatory cytokine production, or SLE-like disease, and, like wild-type mice, produce IL-10 in response to dying cells. Therefore, defects in LAP, rather than canonical autophagy, can cause SLE-like phenomena, and may contribute to the pathogenesis of SLE.

  18. In vivo electrical conductivity of hepatic tumours.

    PubMed

    Haemmerich, Dieter; Staelin, S T; Tsai, J Z; Tungjitkusolmun, S; Mahvi, D M; Webster, J G

    2003-05-01

    Knowledge of electrical tissue conductivity is necessary to determine deposition of electromagnetic energy and can further be used to diagnostically differentiate between normal and neoplastic tissue. We measured 17 rats with a total of 24 tumours of the K12/TRb rat colon cancer cell line. In each animal we measured in vivo hepatic tumour and normal tissue conductivity at seven frequencies from 10 Hz to 1 MHz, at different tumour stages between 6 and 12 weeks after induction. Conductivity of normal liver tissue was 1.26 +/- 0.15 mS cm(-1) at 10 Hz, and 4.61 +/- 0.42 mS cm(-1) at 1 MHz. Conductivity of tumour was 2.69 +/- 0.91 mS cm(-1) at 10 Hz, and 5.23 +/- 0.82 mS cm(-1) at 1 MHz. Conductivity was significantly different between normal and tumour tissue (p < 0.05). We determined the percentage of necrosis and fibrosis at the measurement site. We fitted the conductivity data to the Cole-Cole model. For the tumour data we determined Spearman's correlation coefficients between the Cole-Cole parameters and age, necrosis, fibrosis and tumour volume and found significant correlation between necrosis and the Cole-Cole parameters (p < 0.05). We conclude that necrosis within the tumour and the associated membrane breakdown is likely responsible for the observed change in conductivity.

  19. Wireless Monitoring of Liver Hemodynamics In Vivo

    SciTech Connect

    Akl, Tony; Wilson, Mark A.; Ericson, Milton Nance; Farquhar, Ethan; Cote, Gerard L.

    2014-01-01

    Liver transplants have their highest technical failure rate in the first two weeks following surgery. Currently, there are limited devices for continuous, real-time monitoring of the graft. In this work, a three wavelengths system is presented that combines near-infrared spectroscopy and photoplethysmography with a processing method that can uniquely measure and separate the venous and arterial oxygen contributions. This strategy allows for the quantification of tissue oxygen consumption used to study hepatic metabolic activity and to relate it to tissue stress. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.135 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. The signal is also used to extract the venous oxygen saturation from the direct current (DC) levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19% and 1.39% respectively when no vascular occlusions were induced. This error increased to 2.82% and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of a commercial oximetry catheter used as a reference. This work is the first realization of a wireless optical sensor for continuous monitoring of hepatic hemodynamics.

  20. Erythrocyte membrane elasticity during in vivo ageing.

    PubMed

    Nash, G B; Wyard, S J

    1981-05-01

    Changes in the ability of senescent erythrocytes to pass through the microcirculation may cause them to be trapped in the spleen and removed from the blood. To help understand this process we have measured erythrocyte membrane elasticity, to see whether it changes during in vivo ageing. Human and rabbit red cells were fractionated by isopycnic sedimentation to obtain samples of aged and young cells. These were subjected to micropipette analysis in order to determine their membrane shear elastic modulus. We found that the membrane rigidity did not significantly alter as red cells aged. Previously we have also demonstrated that the changed size and shape of aged cells is unlikely to explain their removal from the circulation (Nash, G.B. and Wyard, S.J. (1981) Biorheology, in the press). Thus we conclude that the lifespan of erythrocytes is not determined by factors related to membrane flexibility or cell shape but may depend on changes in their viscous properties (as suggested by Williams, A.R. and Morris, D.R. (1980), Scand. J. Haematol. 24, 57--62).

  1. Tracking mouse bone marrow monocytes in vivo.

    PubMed

    Hamon, Pauline; Rodero, Mathieu Paul; Combadière, Christophe; Boissonnas, Alexandre

    2015-01-01

    Real time multiphoton imaging provides a great opportunity to study cell trafficking and cell-to-cell interactions in their physiological 3-dimensionnal environment. Biological activities of immune cells mainly rely on their motility capacities. Blood monocytes have short half-life in the bloodstream; they originate in the bone marrow and are constitutively released from it. In inflammatory condition, this process is enhanced, leading to blood monocytosis and subsequent infiltration of the peripheral inflammatory tissues. Identifying the biomechanical events controlling monocyte trafficking from the bone marrow towards the vascular network is an important step to understand monocyte physiopathological relevance. We performed in vivo time-lapse imaging by two-photon microscopy of the skull bone marrow of the Csf1r-Gal4VP16/UAS-ECFP (MacBlue) mouse. The MacBlue mouse expresses the fluorescent reporters enhanced cyan fluorescent protein (ECFP) under the control of a myeloid specific promoter, in combination with vascular network labelling. We describe how this approach enables the tracking of individual medullar monocytes in real time to further quantify the migratory behaviour within the bone marrow parenchyma and the vasculature, as well as cell-to-cell interactions. This approach provides novel insights into the biology of the bone marrow monocyte subsets and allows to further address how these cells can be influenced in specific pathological conditions. PMID:25867540

  2. Difficulty in dislodging in vivo fixed radiostrontium.

    PubMed

    Sonawane, V R; Jagtap, V S; Pahuja, D N; Rajan, M G R; Samuel, A M

    2004-07-01

    Many trials based on the basic phenomena of isotopic dilution, adsorption, ion exchange, chelation, etc., have been attempted for the decorporation of radiostrontium, particularly Sr, after its entry in the in vivo system. We have recently demonstrated a non-isotopic carrier effect of some common calcium salts (calcium = 9 mg mL) to reduce the whole body retention of radiostrontium, if administered within 2 h after radiostrontium exposure and furthermore once daily, in rats, supplemented with calcium fortified diet. However, 25-30% of radiostrontium (compared to 50-60% in untreated animals) was still found to be retained in the animal even after 2 wk of treatment. Trial of some simple interventional measures, which would not adversely affect the animal metabolism, like pyrophosphate and magnesium sulfate, sodium citrate, chitin (a bio-absorbent), crown ether (a metal-chelator), and ammonium chloride, was therefore attempted to dislodge this remaining radiostrontium by switching over these animals to normal diet and subjecting them to different lines of treatment with these simple interventions through diet and drinking water separately for a further 4 wk. However, this remaining portion of radiostrontium is fixed in the bone and is difficult to dislodge. PMID:15194921

  3. Macrophage plasticity and polarization: in vivo veritas

    PubMed Central

    Sica, Antonio; Mantovani, Alberto

    2012-01-01

    Diversity and plasticity are hallmarks of cells of the monocyte-macrophage lineage. In response to IFNs, Toll-like receptor engagement, or IL-4/IL-13 signaling, macrophages undergo M1 (classical) or M2 (alternative) activation, which represent extremes of a continuum in a universe of activation states. Progress has now been made in defining the signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1-M2 or M2-like polarized activation. Functional skewing of mononuclear phagocytes occurs in vivo under physiological conditions (e.g., ontogenesis and pregnancy) and in pathology (allergic and chronic inflammation, tissue repair, infection, and cancer). However, in selected preclinical and clinical conditions, coexistence of cells in different activation states and unique or mixed phenotypes have been observed, a reflection of dynamic changes and complex tissue-derived signals. The identification of mechanisms and molecules associated with macrophage plasticity and polarized activation provides a basis for macrophage-centered diagnostic and therapeutic strategies. PMID:22378047

  4. Feasibility of in vivo cardiac HIFU ablation

    NASA Astrophysics Data System (ADS)

    Fujikura, Kana; Otsuka, Ryo; Homma, Shunichi; Muratore, Robert; Ketterling, Jeffrey A.; Lizzi, Frederic L.

    2001-05-01

    The potential for cardiac applications of HIFU remains unexamined. In order to create reproducible lesions in a beating heart, it is necessary to maintain focusing at a certain position within moving myocardial tissue. One technique is to use multiple short HIFU exposures (0.2 s) and synchronize them with an EKG signal and respiration. The left ventricular free wall (LVFW) of calf hearts were cut into 4-cm cubes, degassed in phosphate buffer saline (PBS), and heated to 37°C. An 80-mm-diam spherical-cap transducer with a focus of 90 mm was operated at a frequency of 4.67 MHz and a nominal focal point intensity of 26.9 kW/cm2. The transducer was coupled to the LVFW using degassed PBS. First, the effect of pericardial fat, focal depth, and temperature on lesion size was individually evaluated. Then the 0.2-s HIFU exposure was applied 10 to 30 times at 4-s intervals. The same HIFU transducer was applied to an open-chest canine LVFW with the same triggering protocol. Dimensions of all lesions were measured by visual examination of the fresh, unstained tissue. A histopathological examination of the lesion was also performed. The in vivo lesions were created in similar size to those in vitro.

  5. Astrocytes regulate cortical state switching in vivo.

    PubMed

    Poskanzer, Kira E; Yuste, Rafael

    2016-05-10

    The role of astrocytes in neuronal function has received increasing recognition, but disagreement remains about their function at the circuit level. Here we use in vivo two-photon calcium imaging of neocortical astrocytes while monitoring the activity state of the local neuronal circuit electrophysiologically and optically. We find that astrocytic calcium activity precedes spontaneous circuit shifts to the slow-oscillation-dominated state, a neocortical rhythm characterized by synchronized neuronal firing and important for sleep and memory. Further, we show that optogenetic activation of astrocytes switches the local neuronal circuit to this slow-oscillation state. Finally, using two-photon imaging of extracellular glutamate, we find that astrocytic transients in glutamate co-occur with shifts to the synchronized state and that optogenetically activated astrocytes can generate these glutamate transients. We conclude that astrocytes can indeed trigger the low-frequency state of a cortical circuit by altering extracellular glutamate, and therefore play a causal role in the control of cortical synchronizations. PMID:27122314

  6. Prostate elastography: preliminary in vivo results

    NASA Astrophysics Data System (ADS)

    Alam, S. K.; Feleppa, E. J.; Kalisz, A.; Ramchandran, S.; Ennis, R. D.; Lizzi, Frederick L.; Wuu, C.-S.; Ketterling, Jeffrey A.

    2005-04-01

    We report preliminary results from our investigation of in vivo prostate elastography. Fewer than 50% of all prostate cancers are typically visible in current clinical imaging modalities. Elastography displays a map of strain that results when tissue is externally compressed. Thus, elastography is ideal for imaging prostate cancers because they are generally stiffer than the surrounding tissue and stiffer regions usually exhibit lower strain in elastograms. In our study, digital radio-frequency (RF) ultrasound echo data were acquired from prostate-cancer patients undergoing brachytherapy. Seed placement is guided by a transrectal ultrasound (TRUS) probe, which is held in a mechanical fixture. The probe can be moved in XYZ directions and tilted. The probe face, in contact with the rectal wall, is used to apply a compression force to the immediately adjacent prostate. We also used a water-filled (acoustic) coupling balloon to compress the prostate by increasing the water volume inside the balloon. In each scan plane (transverse), we acquired RF data from successive scans at the scanner frame rate as the deformation force on the rectal wall was continuously increased. We computed strain using 1D RF cross-correlation analysis. The compression method based on fixture displacement produced low-noise elastograms that beautifully displayed the prostate architecture and emphasized stiff areas. Balloon-based compression also produced low-noise elastograms. Initial results demonstrate that elastography may be useful in the detection and evaluation of prostate cancers, occult in conventional imaging modalities.

  7. Responsive corneosurfametry following in vivo skin preconditioning.

    PubMed

    Uhoda, E; Goffin, V; Pierard, G E

    2003-12-01

    Skin is subjected to many environmental threats, some of which altering the structure and function of the stratum corneum. Among them, surfactants are recognized factors that may influence irritant contact dermatitis. The present study was conducted to compare the variations in skin capacitance and corneosurfametry (CSM) reactivity before and after skin exposure to repeated subclinical injuries by 2 hand dishwashing liquids. A forearm immersion test was performed on 30 healthy volunteers. 2 daily soak sessions were performed for 5 days. At inclusion and the day following the last soak session, skin capacitance was measured and cyanoacrylate skin-surface strippings were harvested. The latter specimens were used for the ex vivo microwave CSM. Both types of assessments clearly differentiated the 2 hand dishwashing liquids. The forearm immersion test allowed the discriminant sensitivity of CSM to increase. Intact skin capacitance did not predict CSM data. By contrast, a significant correlation was found between the post-test conductance and the corresponding CSM data. In conclusion, a forearm immersion test under realistic conditions can discriminate the irritation potential between surfactant-based products by measuring skin conductance and performing CSM. In vivo skin preconditioning by surfactants increases CSM sensitivity to the same surfactants. PMID:15025702

  8. Platelet generation in vivo and in vitro.

    PubMed

    Wang, Biao; Zheng, Jiansheng

    2016-01-01

    Platelet (PLT) transfusion, which is the primary cell therapy for thrombocytopenia, has been a source of concern in recent years due to its limitations of donor-dependent supply and soaring costs. In vitro platelet generation on an industrial scale is a possible solution requiring exploration. The technology of platelet generation ex vivo has been widely studied across the world, though the mechanisms of physiological thrombopoiesis and platelet biology function in vivo still remain elusive today. Various culture systems have been studied, most of which proved quite inefficient in generating functional platelets ex vivo, so there is still a long way to reach our ultimate goal of generating a fully functional platelet in vitro on an industrial scale. This review integrates the latest research into physiological platelet biogenesis and ex vivo-platelet/megakaryocyte (MK) generation protocols with a focus on the ability to generate PLT/MK in large quantities, summarizes current culture systems based on induced human pluripotent stem cells and adipose-derived stem cells, and discusses significant challenges that must be overcome for these approaches to be perfected. PMID:27390629

  9. Human antibody Fc deamidation in vivo.

    PubMed

    Liu, Y Diana; van Enk, Jian Zhang; Flynn, Gregory C

    2009-10-01

    Protein and peptide deamidation occurs spontaneously in vitro under relatively mild conditions. For antibodies and other therapeutic proteins, great effort is placed in manufacturing and storage to minimize this form of degradation. Concern has been especially great in cases where deamidation has been shown to impact protein activity. Here we monitored asparagine deamidation from a recombinant human antibody in humans and found that among the conserved sites, only Asn 384 deamidated at an appreciable rate. Under physiological temperature and pH conditions, in vitro antibody deamidation followed similar kinetics, indicating that simple incubation reactions may be used to model in vivo behavior. Endogenous IgG isolated from human serum possessed 23% deamidation at this site, further demonstrating that this modification is naturally occurring. Thus, deamidation generated in manufacturing and storage does not fully determine the patient exposure to the attribute. Instead, pharmacokinetic data along with the deamidation kinetics are combined to predict patient exposure. The deamidation rate can also be used to estimate the serum lifetime of antibodies. This approach could potentially be used to estimate turnover for other cellular or extracellular proteins.

  10. Neuronal avalanches in spontaneous activity in vivo.

    PubMed

    Hahn, Gerald; Petermann, Thomas; Havenith, Martha N; Yu, Shan; Singer, Wolf; Plenz, Dietmar; Nikolic, Danko

    2010-12-01

    Many complex systems give rise to events that are clustered in space and time, thereby establishing a correlation structure that is governed by power law statistics. In the cortex, such clusters of activity, called "neuronal avalanches," were recently found in local field potentials (LFPs) of spontaneous activity in acute cortex slices, slice cultures, the developing cortex of the anesthetized rat, and premotor and motor cortex of awake monkeys. At present, it is unclear whether neuronal avalanches also exist in the spontaneous LFPs and spike activity in vivo in sensory areas of the mature brain. To address this question, we recorded spontaneous LFPs and extracellular spiking activity with multiple 4 × 4 microelectrode arrays (Michigan Probes) in area 17 of adult cats under anesthesia. A cluster of events was defined as a consecutive sequence of time bins Δt (1-32 ms), each containing at least one LFP event or spike anywhere on the array. LFP cluster sizes consistently distributed according to a power law with a slope largely above -1.5. In two thirds of the corresponding experiments, spike clusters also displayed a power law that displayed a slightly steeper slope of -1.8 and was destroyed by subsampling operations. The power law in spike clusters was accompanied with stronger temporal correlations between spiking activities of neurons that spanned longer time periods compared with spike clusters lacking power law statistics. The results suggest that spontaneous activity of the visual cortex under anesthesia has the properties of neuronal avalanches.

  11. Astrocytes regulate cortical state switching in vivo

    PubMed Central

    Poskanzer, Kira E.; Yuste, Rafael

    2016-01-01

    The role of astrocytes in neuronal function has received increasing recognition, but disagreement remains about their function at the circuit level. Here we use in vivo two-photon calcium imaging of neocortical astrocytes while monitoring the activity state of the local neuronal circuit electrophysiologically and optically. We find that astrocytic calcium activity precedes spontaneous circuit shifts to the slow-oscillation–dominated state, a neocortical rhythm characterized by synchronized neuronal firing and important for sleep and memory. Further, we show that optogenetic activation of astrocytes switches the local neuronal circuit to this slow-oscillation state. Finally, using two-photon imaging of extracellular glutamate, we find that astrocytic transients in glutamate co-occur with shifts to the synchronized state and that optogenetically activated astrocytes can generate these glutamate transients. We conclude that astrocytes can indeed trigger the low-frequency state of a cortical circuit by altering extracellular glutamate, and therefore play a causal role in the control of cortical synchronizations. PMID:27122314

  12. Imaging inflammatory plasma leakage in vivo.

    PubMed

    Kenne, E; Lindbom, L

    2011-05-01

    Increased vascular permeability and consequent plasma leakage from postcapillary venules is a cardinal sign of inflammation. Although the movement of plasma constituents from the vasculature to the affected tissue aids in clearing the inflammatory stimulus, excessive plasma extravasation can lead to hospitalisation or death in cases such as influenza-induced pneumonia, burns or brain injury. The use of intravital imaging has significantly contributed to the understanding of the mechanisms controlling the vascular permeability alterations that occur during inflammation. Today, intravital imaging can be performed using optical and non-optical techniques. Optical techniques, which are generally used in experimental settings, include traditional intravital fluorescence microscopy and near-infrared fluorescence imaging. Magnetic resonance (MRI) and radioisotopic imaging are used mainly in the clinical setting, but are increasingly used in experimental work, and can detect plasma leakage without optics. Although these methods are all able to visualise inflammatory plasma leakage in vivo, the spatial and temporal resolution differs between the techniques. In addition, they vary with regards to invasiveness and availability. This overview discusses the use of imaging techniques in the visualisation of inflammatory plasma leakage. PMID:21437352

  13. Responsive corneosurfametry following in vivo skin preconditioning.

    PubMed

    Uhoda, E; Goffin, V; Pierard, G E

    2003-12-01

    Skin is subjected to many environmental threats, some of which altering the structure and function of the stratum corneum. Among them, surfactants are recognized factors that may influence irritant contact dermatitis. The present study was conducted to compare the variations in skin capacitance and corneosurfametry (CSM) reactivity before and after skin exposure to repeated subclinical injuries by 2 hand dishwashing liquids. A forearm immersion test was performed on 30 healthy volunteers. 2 daily soak sessions were performed for 5 days. At inclusion and the day following the last soak session, skin capacitance was measured and cyanoacrylate skin-surface strippings were harvested. The latter specimens were used for the ex vivo microwave CSM. Both types of assessments clearly differentiated the 2 hand dishwashing liquids. The forearm immersion test allowed the discriminant sensitivity of CSM to increase. Intact skin capacitance did not predict CSM data. By contrast, a significant correlation was found between the post-test conductance and the corresponding CSM data. In conclusion, a forearm immersion test under realistic conditions can discriminate the irritation potential between surfactant-based products by measuring skin conductance and performing CSM. In vivo skin preconditioning by surfactants increases CSM sensitivity to the same surfactants.

  14. Mycoplasma biofilms ex vivo and in vivo.

    PubMed

    Simmons, Warren L; Dybvig, Kevin

    2009-06-01

    Biofilms are communities of microorganisms that are encased in polymeric matrixes and grow attached to biotic or abiotic surfaces. Despite their enhanced ability to resist antimicrobials and components of the immune system in vitro, few studies have addressed the interactions of biofilms with the host at the organ level. Although mycoplasmas have been shown to form biofilms on glass and plastic surfaces, it has not been determined whether they form biofilms on the tracheal epithelium. We developed a tracheal organ-mounting system that allowed the entire surface of the tracheal lumen to be scanned using fluorescence microscopy. We observed the biofilms formed by the murine respiratory pathogen Mycoplasma pulmonis on the epithelium of trachea in tracheal organ culture and in experimentally infected mice and found similar structure and biological characteristics as biofilms formed in vitro. This tracheal organ-mounting system can be used to study interactions between biofilms formed by respiratory pathogens and the host epithelium and to identify the factors that contribute to biofilm formation in vivo.

  15. In Vivo Gait Analysis During Bone Transport.

    PubMed

    Mora-Macías, J; Reina-Romo, E; Morgaz, J; Domínguez, J

    2015-09-01

    The load bearing characteristics of the intervened limb over time in vivo are important to know in distraction osteogenesis and bone healing for the characterization of the bone maturation process. Gait analyses were performed for a group of sheep in which bone transport was carried out. The ground reaction force was measured by means of a force platform, and the gait parameters (i.e., the peak, the mean vertical ground reaction force and the impulse) were calculated during the stance phase for each limb. The results showed that these gait parameters decreased in the intervened limb and interestingly increased in the other limbs due to the implantation of the fixator. Additionally, during the process, the gait parameters exponentially approached the values for healthy animals. Corresponding radiographies showed an increasing level of ossification in the callus. This study shows, as a preliminary approach to be confirmed with more experiments, that gait analysis could be used as an alternative method to control distraction osteogenesis or bone healing. For example, these analyses could determine the appropriate time to remove the fixator. Furthermore, gait analysis has advantages over other methods because it provides quantitative data and does not require instrumented fixators.

  16. Controlled cobalt doping of magnetosomes in vivo.

    PubMed

    Staniland, Sarah; Williams, Wyn; Telling, Neil; Van Der Laan, Gerrit; Harrison, Andrew; Ward, Bruce

    2008-03-01

    Magnetotactic bacteria biomineralize iron into magnetite (Fe3O4) nanoparticles that are surrounded by lipid vesicles. These 'magnetosomes' have considerable potential for use in bio- and nanotechnological applications because of their narrow size and shape distribution and inherent biocompatibility. The ability to tailor the magnetic properties of magnetosomes by chemical doping would greatly expand these applications; however, the controlled doping of magnetosomes has so far not been achieved. Here, we report controlled in vivo cobalt doping of magnetosomes in three strains of the bacterium Magnetospirillum. The presence of cobalt increases the coercive field of the magnetosomes--that is, the field necessary to reverse their magnetization--by 36-45%, depending on the strain and the cobalt content. With elemental analysis, X-ray absorption and magnetic circular dichroism, we estimate the cobalt content to be between 0.2 and 1.4%. These findings provide an important advance in designing biologically synthesized nanoparticles with useful highly tuned magnetic properties. PMID:18654488

  17. Imaging axon pathfinding in zebrafish in vivo.

    PubMed

    Leung, Louis; Holt, Christine E

    2012-09-01

    Axon pathfinding in the developing animal involves a highly dynamic process in which the axonal growth cone makes continuous decisions as it navigates toward its target. Changes occurring in the growth cone with respect to retracting from or extending into complex new territories can occur in minutes. Thus, the advent of strategies to visualize axon path-finding in vivo in a live intact animal is crucial for a better understanding of how the growth cone makes such rapid decisions in response to multiple cues. Combining these strategies with loss-of-function and/or gain-of-function techniques, one can gain some insight as to which molecules are crucial to particular growth cone behaviors at specific choice points during navigation. The major advantage of using zebrafish lies in the accessibility of major axon tracts for live microscopy, as their embryonic development occurs ex utero. Furthermore, the robust embryos remain healthy during immobilization and allow for good imaging for long periods. This protocol describes the method for stabilizing and preparing live zebrafish embryos for imaging labeled axonal tracts at high spatial and temporal resolution for up to 72 h. It has been used for retinotectal axon pathfinding, but can be adapted to visualize other axon tracts of interest. PMID:22949713

  18. Imaging axon pathfinding in Xenopus in vivo.

    PubMed

    Leung, Louis; Holt, Christine E

    2012-09-01

    Axon pathfinding in the developing animal involves a highly dynamic process in which the axonal growth cone makes continuous decisions as it navigates toward its target. Changes occurring in the growth cone with respect to retracting from or extending into complex new territories can occur in minutes. Thus, the advent of strategies to visualize axon path-finding in vivo in a live intact animal is crucial for a better understanding of how the growth cone makes such rapid decisions in response to multiple cues. Combining these strategies with loss-of-function and/or gain-of-function techniques allows one to gain some insight as to which molecules are crucial to particular growth cone behaviors at specific choice points during navigation. The main advantage of using Xenopus lies in the accessibility of major axon tracts for live microscopy, as their embryonic development occurs ex utero. Furthermore, the robust embryos remain healthy during immobilization and allow for good imaging for long periods. This protocol describes the methods for stabilizing and preparing live Xenopus embryos for imaging labeled axonal tracts at high spatial and temporal resolution for up to 72 h. This approach can been used to investigate how the knockdown of certain gene functions can affect the speed of navigation through the well-studied Xenopus retinotectal pathway. It can be adapted to visualize other axon tracts of interest. PMID:22949712

  19. Thermal Assisted In Vivo Gene Electrotransfer.

    PubMed

    Donate, Amy; Bulysheva, Anna; Edelblute, Chelsea; Jung, Derrick; Malik, Mohammad A; Guo, Siqi; Burcus, Niculina; Schoenbach, Karl; Heller, Richard

    2016-01-01

    Gene electrotransfer is an effective approach for delivering plasmid DNA to a variety of tissues. Delivery of molecules with electric pulses requires control of the electrical parameters to achieve effective delivery. Since discomfort or tissue damage may occur with high applied voltage, the reduction of the applied voltage while achieving the desired expression may be an important improvement. One possible approach is to combine electrotransfer with exogenously applied heat. Previous work performed in vitro demonstrated that increasing temperature before pulsing can enhance gene expression and made it possible to reduce electric fields while maintaining expression levels. In the study reported here, this combination was evaluated in vivo using a novel electrode device designed with an inserted laser for application of heat. The results obtained in this study demonstrated that increased temperature during electrotransfer increased expression or maintained expression with a reduction in applied voltage. With further optimization this approach may provide the basis for both a novel method and a novel instrument that may greatly enhance translation of gene electrotransfer.

  20. In vivo photoacoustic imaging of mouse embryos

    NASA Astrophysics Data System (ADS)

    Laufer, Jan; Norris, Francesca; Cleary, Jon; Zhang, Edward; Treeby, Bradley; Cox, Ben; Johnson, Peter; Scambler, Pete; Lythgoe, Mark; Beard, Paul

    2012-06-01

    The ability to noninvasively image embryonic vascular anatomy in mouse models is an important requirement for characterizing the development of the normal cardiovascular system and malformations in the heart and vascular supply. Photoacoustic imaging, which can provide high resolution non invasive images of the vasculature based upon optical absorption by endogenous hemoglobin, is well suited to this application. In this study, photoacoustic images of mouse embryos were obtained ex vivo and in vivo. The images show intricate details of the embryonic vascular system to depths of up to 10 mm, which allowed whole embryos to be imaged in situ. To achieve this, an all-optical photoacoustic scanner and a novel time reversal image reconstruction algorithm, which provide deep tissue imaging capability while maintaining high spatial resolution and contrast were employed. This technology may find application as an imaging tool for preclinical embryo studies in developmental biology as well as more generally in preclinical and clinical medicine for studying pathologies characterized by changes in the vasculature.

  1. Thermoacoustic in vivo determination of blood oxygenation

    NASA Astrophysics Data System (ADS)

    Kiser, William L., Jr.; Kruger, Robert A.; Reinecke, Daniel R.; Kruger, Gabe A.; Miller, Kathy D.

    2004-07-01

    We have utilized a prototype Thermoacoustic Computed Tomography Small Animal Imaging System to acquire images of athymic mice with bilateral tumors implanted in the cranial mammary fat pads. The breast tumor cell lines used in the study, which are MCF7, and MCF7 transfected with Vascular Endothelial Growth Factor (VEGF), exhibit distinctly contrasting levels of vascularization. Three dimensional images of the mice, acquired using pulses of NIR stimulating light, demonstrate the ability of the system to generate high resolution images of the vascular system up to one inch deep in tissue, and at the same time, differentiate tissue types based on the infrared absorption properties of the tissue; a property related in part to blood content and oxygenation levels. We have processed images acquired at different stimulating wavelengths to generate images representative of the distribution of oxygenated and deoxygenated hemoglobin throughout the tumors. The images demonstrate the in vivo capabilities of the imaging system and map system structure as well as the total, oxygenated and deoxygenated hemoglobin components of the blood.

  2. In vivo and in vitro mixture modeling of endocrine disruptors

    EPA Science Inventory

    Humans, fish and wildlife are exposed to more than one chemical at a time. There is concern over the potential effects of exposure to mixtures of EDs. We have conducted invitro and in vivo studies to determine how EDs in mixtures interact. Our in vivo studies have examined the ef...

  3. Wireless monitoring of liver hemodynamics in vivo.

    PubMed

    Akl, Tony J; Wilson, Mark A; Ericson, M Nance; Farquhar, Ethan; Coté, Gerard L

    2014-01-01

    Liver transplants have their highest technical failure rate in the first two weeks following surgery. Currently, there are limited devices for continuous, real-time monitoring of the graft. In this work, a three wavelengths system is presented that combines near-infrared spectroscopy and photoplethysmography with a processing method that can uniquely measure and separate the venous and arterial oxygen contributions. This strategy allows for the quantification of tissue oxygen consumption used to study hepatic metabolic activity and to relate it to tissue stress. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.135 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. The signal is also used to extract the venous oxygen saturation from the direct current (DC) levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19% and 1.39% respectively when no vascular occlusions were induced. This error increased to 2.82% and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of a commercial oximetry catheter used as a reference. This work is the first realization of a wireless optical sensor for continuous monitoring of hepatic hemodynamics. PMID:25019160

  4. Wireless Monitoring of Liver Hemodynamics In Vivo

    PubMed Central

    Akl, Tony J.; Wilson, Mark A.; Ericson, M. Nance; Farquhar, Ethan; Coté, Gerard L.

    2014-01-01

    Liver transplants have their highest technical failure rate in the first two weeks following surgery. Currently, there are limited devices for continuous, real-time monitoring of the graft. In this work, a three wavelengths system is presented that combines near-infrared spectroscopy and photoplethysmography with a processing method that can uniquely measure and separate the venous and arterial oxygen contributions. This strategy allows for the quantification of tissue oxygen consumption used to study hepatic metabolic activity and to relate it to tissue stress. The sensor is battery operated and communicates wirelessly with a data acquisition computer which provides the possibility of implantation provided sufficient miniaturization. In two in vivo porcine studies, the sensor tracked perfusion changes in hepatic tissue during vascular occlusions with a root mean square error (RMSE) of 0.135 mL/min/g of tissue. We show the possibility of using the pulsatile wave to measure the arterial oxygen saturation similar to pulse oximetry. The signal is also used to extract the venous oxygen saturation from the direct current (DC) levels. Arterial and venous oxygen saturation changes were measured with an RMSE of 2.19% and 1.39% respectively when no vascular occlusions were induced. This error increased to 2.82% and 3.83% when vascular occlusions were induced during hypoxia. These errors are similar to the resolution of a commercial oximetry catheter used as a reference. This work is the first realization of a wireless optical sensor for continuous monitoring of hepatic hemodynamics. PMID:25019160

  5. Osteoblast Menin Regulates Bone Mass in Vivo*

    PubMed Central

    Kanazawa, Ippei; Canaff, Lucie; Abi Rafeh, Jad; Angrula, Aarti; Li, Jingjing; Riddle, Ryan C.; Boraschi-Diaz, Iris; Komarova, Svetlana V.; Clemens, Thomas L.; Murshed, Monzur; Hendy, Geoffrey N.

    2015-01-01

    Menin, the product of the multiple endocrine neoplasia type 1 (Men1) tumor suppressor gene, mediates the cell proliferation and differentiation actions of transforming growth factor-β (TGF-β) ligand family members. In vitro, menin modulates osteoblastogenesis and osteoblast differentiation promoted and sustained by bone morphogenetic protein-2 (BMP-2) and TGF-β, respectively. To examine the in vivo function of menin in bone, we conditionally inactivated Men1 in mature osteoblasts by crossing osteocalcin (OC)-Cre mice with floxed Men1 (Men1f/f) mice to generate mice lacking menin in differentiating osteoblasts (OC-Cre;Men1f/f mice). These mice displayed significant reduction in bone mineral density, trabecular bone volume, and cortical bone thickness compared with control littermates. Osteoblast and osteoclast number as well as mineral apposition rate were significantly reduced, whereas osteocyte number was increased. Primary calvarial osteoblasts proliferated more quickly but had deficient mineral apposition and alkaline phosphatase activity. Although the mRNA expression of osteoblast marker and cyclin-dependent kinase inhibitor genes were all reduced, that of cyclin-dependent kinase, osteocyte marker, and pro-apoptotic genes were increased in isolated Men1 knock-out osteoblasts compared with controls. In contrast to the knock-out mice, transgenic mice overexpressing a human menin cDNA in osteoblasts driven by the 2.3-kb Col1a1 promoter, showed a gain of bone mass relative to control littermates. Osteoblast number and mineral apposition rate were significantly increased in the Col1a1-Menin-Tg mice. Therefore, osteoblast menin plays a key role in bone development, remodeling, and maintenance. PMID:25538250

  6. Neuronal Avalanches in Spontaneous Activity In Vivo

    PubMed Central

    Hahn, Gerald; Petermann, Thomas; Havenith, Martha N.; Yu, Shan; Singer, Wolf; Plenz, Dietmar

    2010-01-01

    Many complex systems give rise to events that are clustered in space and time, thereby establishing a correlation structure that is governed by power law statistics. In the cortex, such clusters of activity, called “neuronal avalanches,” were recently found in local field potentials (LFPs) of spontaneous activity in acute cortex slices, slice cultures, the developing cortex of the anesthetized rat, and premotor and motor cortex of awake monkeys. At present, it is unclear whether neuronal avalanches also exist in the spontaneous LFPs and spike activity in vivo in sensory areas of the mature brain. To address this question, we recorded spontaneous LFPs and extracellular spiking activity with multiple 4 × 4 microelectrode arrays (Michigan Probes) in area 17 of adult cats under anesthesia. A cluster of events was defined as a consecutive sequence of time bins Δt (1–32 ms), each containing at least one LFP event or spike anywhere on the array. LFP cluster sizes consistently distributed according to a power law with a slope largely above –1.5. In two thirds of the corresponding experiments, spike clusters also displayed a power law that displayed a slightly steeper slope of −1.8 and was destroyed by subsampling operations. The power law in spike clusters was accompanied with stronger temporal correlations between spiking activities of neurons that spanned longer time periods compared with spike clusters lacking power law statistics. The results suggest that spontaneous activity of the visual cortex under anesthesia has the properties of neuronal avalanches. PMID:20631221

  7. In Vivo Imaging of Human Neuroinflammation.

    PubMed

    Albrecht, Daniel S; Granziera, Cristina; Hooker, Jacob M; Loggia, Marco L

    2016-04-20

    Neuroinflammation is implicated in the pathophysiology of a growing number of human disorders, including multiple sclerosis, chronic pain, traumatic brain injury, and amyotrophic lateral sclerosis. As a result, interest in the development of novel methods to investigate neuroinflammatory processes, for the purpose of diagnosis, development of new therapies, and treatment monitoring, has surged over the past 15 years. Neuroimaging offers a wide array of non- or minimally invasive techniques to characterize neuroinflammatory processes. The intent of this Review is to provide brief descriptions of currently available neuroimaging methods to image neuroinflammation in the human central nervous system (CNS) in vivo. Specifically, because of the relatively widespread accessibility of equipment for nuclear imaging (positron emission tomography [PET]; single photon emission computed tomography [SPECT]) and magnetic resonance imaging (MRI), we will focus on strategies utilizing these technologies. We first provide a working definition of "neuroinflammation" and then discuss available neuroimaging methods to study human neuroinflammatory processes. Specifically, we will focus on neuroimaging methods that target (1) the activation of CNS immunocompetent cells (e.g. imaging of glial activation with TSPO tracer [(11)C]PBR28), (2) compromised BBB (e.g. identification of MS lesions with gadolinium-enhanced MRI), (3) CNS-infiltration of circulating immune cells (e.g. tracking monocyte infiltration into brain parenchyma with iron oxide nanoparticles and MRI), and (4) pathological consequences of neuroinflammation (e.g. imaging apoptosis with [(99m)Tc]Annexin V or iron accumulation with T2* relaxometry). This Review provides an overview of state-of-the-art techniques for imaging human neuroinflammation which have potential to impact patient care in the foreseeable future. PMID:26985861

  8. Lung Injury after In Vivo Reperfusion

    PubMed Central

    Matot, Idit; Einav, Sharon; Weiniger, Carolyn F.; Pearl, Ron; Abramovitch, Rinat; Joshi, Balachandra V.; Jacobson, Kenneth A.

    2009-01-01

    Background Although short-term findings after lung reperfusion have been extensively reported, in vivo animal studies have not described outcome beyond the immediate time period. Therefore, the authors evaluated lung injury 27 h after reperfusion. They also investigated whether attenuation of lung injury with the A3 adenosine receptor agonist MRS3558 was sustained beyond the immediate time period. Methods In intact-chest, spontaneously breathing cats in which the left lower lung lobe was isolated and subjected to 2 h of ischemia and 3 h of reperfusion, MRS3558 was administered before reperfusion. Animals were killed 3 or 27 h after reperfusion. Results When compared with 3 h of reperfusion, at 27 h the left lower lobe showed reduced apoptosis and no change in inflammation, but increased edema. Increased edema of the nonischemic right lung and hypoxemia were observed at 27 h after left lower lobe reperfusion. Increases in phosphorylated p38 levels were found at 3 h of reperfusion compared with control lung, with further increases at 27 h. The attenuation of injury observed with MRS3558 treatment at 3 h of reperfusion was sustained at 27 h. Conclusions Lung edema may worsen hours after the immediate postreperfusion period, even though lung apoptosis and inflammation are reduced or show no change, respectively. This was associated with further increases in phosphorylated p38 levels. The nonischemic lung may also be affected, suggesting a systemic response to reperfusion. In addition, early attenuation of injury is beneficial beyond the immediate period after reperfusion. Treatment aimed at inhibiting p38 activation, such as A3 receptor activation, should be further studied to explore its potential long-term beneficial effect. PMID:18648236

  9. Towards an in vivo wireless mobile robot for surgical assistance.

    PubMed

    Hawks, Jeff A; Rentschler, Mark E; Redden, Lee; Infanger, Roger; Dumpert, Jason; Farritor, Shane; Oleynikov, Dmitry; Platt, Stephen R

    2008-01-01

    The use of miniature in vivo robots that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Previous work has demonstrated that mobile and fixed-base in vivo robots can be used to improve visualization of the surgical field and perform surgical tasks such as collecting biopsy tissue samples. All of these robots used tethers to provide for power and data transmission. This paper describes recent work focused on developing a modular wireless mobile platform that could be used for in vivo robotic sensing and manipulation applications. One vision for these types of self-contained in vivo robotic devices is that they could be easily carried and deployed by non-medical personnel at the site of an injury. Such wireless in vivo robots are much more transportable and lower cost than current robotic surgical assistants, and could ultimately allow a surgeon to become a remote first responder irrespective of the location of the patient. PMID:18391277

  10. Rotary press utilizing a flexible die wall.

    PubMed

    Amidon, G E; Smith, D P; Hiestand, E N

    1981-06-01

    A die with a flexible wall was constructed and evaluated on a specially modified instrumented rotary tablet press. The design permits an inward deflection of the die wall by a side punch, which rolls past a side compression roll during compression-decompression. The side compression roll is instrumented to monitor the applied side compression roll forces. On decompression, return of the die wall to its original position permits release of residual die wall pressure. The decreased residual die wall pressure can decrease fracture and capping of tablets for problem formulations. The performance was tested on three experimental formulations. For these formulations, tablets made in a conventional die exhibited severe capping problems. However, most tablets compressed in the special die were superior. With proper adjustment of punch and die wall compression forces, excellent tablets could be manufactured. The merits of the special die and modified tablet machine are substantiated, although this initial design did not provide adequate die wall pressure for all formulations. Further engineering efforts could result in practical production equipment.

  11. Evaluation of permanent die coatings to improve the wear resistance of die casting dies. Final project report, January 1, 1995--April 30, 1997

    SciTech Connect

    Shivpuri, R.

    1997-09-18

    Die Casting dies are subject to severe service conditions during the die casting operation. While these severe conditions are necessary to achieve high production rates, they cause the dies which are commonly made of H13 die steel, to suffer frequent failures. The major die failure mechanisms are erosion or washout, Heat checking, soldering and corrosion. Due to their geometrical complexity, die casting dies are very expensive (some dies cost over a million dollars), and thus a large number of parts have to be produced by a die, to justify this cost and leverage the advantages of the die casting process (high production rates, low manpower costs). A potential increase in the die service life, thus has a significant impact on the economics of the die; casting operation. There are many ways to extend die life: developing new wear resistant die materials, developing new surface treatments including coatings, improving heat treatment of existing H13 dies, using better lubricants that can protect the die material, or modifying the die geometry and process parameters to reduce the intensity of wear. Of these the use of coatings to improve the wear resistance of the die surface has shown a lot of promise. Consequently, use of coatings in the die casting industry and their wide use to decrease die wear can improve significantly the productivity of shop operations resulting in large savings in material and energy usage.

  12. Optimized in vivo transfer of small interfering RNA targeting dermal tissue using in vivo surface electroporation.

    PubMed

    Broderick, Kate E; Chan, Amy; Lin, Feng; Shen, Xuefei; Kichaev, Gleb; Khan, Amir S; Aubin, Justin; Zimmermann, Tracy S; Sardesai, Niranjan Y

    2012-01-01

    Electroporation (EP) of mammalian tissue is a technique that has been used successfully in the clinic for the delivery of genetic-based vaccines in the form of DNA plasmids. There is great interest in platforms which efficiently deliver RNA molecules such as messenger RNA and small interfering RNA (siRNA) to mammalian tissue. However, the in vivo delivery of RNA enhanced by EP has not been extensively characterized. This paper details the optimization of electrical parameters for a novel low-voltage EP method to deliver oligonucleotides (both DNA and RNA) to dermal tissue in vivo. Initially, the electrical parameters were optimized for dermal delivery of plasmid DNA encoding green fluorescent protein (GFP) using this novel surface dermal EP device. While all investigated parameters resulted in visible transfection, voltage parameters in the 10 V range elicited the most robust signal. The parameters optimized for DNA, were then assessed for translation of successful electrotransfer of siRNA into dermal tissue. Robust tagged-siRNA transfection in skin was detected. We then assessed whether these parameters translated to successful transfer of siRNA resulting in gene knockdown in vivo. Using a reporter gene construct encoding GFP and tagged siRNA targeting the GFP message, we show simultaneous transfection of the siRNA to the skin via EP and the concomitant knockdown of the reporter gene signal. The siRNA delivery was accomplished with no evidence of injection site inflammation or local tissue damage. The minimally invasive low-voltage EP method is thus capable of efficiently delivering both DNA and RNA molecules to dermal tissue in a tolerable manner. PMID:23344722

  13. Infection-induced NETosis is a dynamic process involving neutrophil multitasking in vivo.

    PubMed

    Yipp, Bryan G; Petri, Björn; Salina, Davide; Jenne, Craig N; Scott, Brittney N V; Zbytnuik, Lori D; Pittman, Keir; Asaduzzaman, Muhammad; Wu, Kaiyu; Meijndert, H Christopher; Malawista, Stephen E; de Boisfleury Chevance, Anne; Zhang, Kunyan; Conly, John; Kubes, Paul

    2012-09-01

    Neutrophil extracellular traps (NETs) are released as neutrophils die in vitro in a process requiring hours, leaving a temporal gap that invasive microbes may exploit. Neutrophils capable of migration and phagocytosis while undergoing NETosis have not been documented. During Gram-positive skin infections, we directly visualized live polymorphonuclear cells (PMNs) in vivo rapidly releasing NETs, which prevented systemic bacterial dissemination. NETosis occurred during crawling, thereby casting large areas of NETs. NET-releasing PMNs developed diffuse decondensed nuclei, ultimately becoming devoid of DNA. Cells with abnormal nuclei showed unusual crawling behavior highlighted by erratic pseudopods and hyperpolarization consistent with the nucleus being a fulcrum for crawling. A requirement for both Toll-like receptor 2 and complement-mediated opsonization tightly regulated NET release. Additionally, live human PMNs injected into mouse skin developed decondensed nuclei and formed NETS in vivo, and intact anuclear neutrophils were abundant in Gram-positive human abscesses. Therefore early in infection NETosis involves neutrophils that do not undergo lysis and retain the ability to multitask.

  14. Spontaneous hair cell regeneration in the neonatal mouse cochlea in vivo.

    PubMed

    Cox, Brandon C; Chai, Renjie; Lenoir, Anne; Liu, Zhiyong; Zhang, LingLi; Nguyen, Duc-Huy; Chalasani, Kavita; Steigelman, Katherine A; Fang, Jie; Rubel, Edwin W; Cheng, Alan G; Zuo, Jian

    2014-02-01

    Loss of cochlear hair cells in mammals is currently believed to be permanent, resulting in hearing impairment that affects more than 10% of the population. Here, we developed two genetic strategies to ablate neonatal mouse cochlear hair cells in vivo. Both Pou4f3(DTR/+) and Atoh1-CreER™; ROSA26(DTA/+) alleles allowed selective and inducible hair cell ablation. After hair cell loss was induced at birth, we observed spontaneous regeneration of hair cells. Fate-mapping experiments demonstrated that neighboring supporting cells acquired a hair cell fate, which increased in a basal to apical gradient, averaging over 120 regenerated hair cells per cochlea. The normally mitotically quiescent supporting cells proliferated after hair cell ablation. Concurrent fate mapping and labeling with mitotic tracers showed that regenerated hair cells were derived by both mitotic regeneration and direct transdifferentiation. Over time, regenerated hair cells followed a similar pattern of maturation to normal hair cell development, including the expression of prestin, a terminal differentiation marker of outer hair cells, although many new hair cells eventually died. Hair cell regeneration did not occur when ablation was induced at one week of age. Our findings demonstrate that the neonatal mouse cochlea is capable of spontaneous hair cell regeneration after damage in vivo. Thus, future studies on the neonatal cochlea might shed light on the competence of supporting cells to regenerate hair cells and on the factors that promote the survival of newly regenerated hair cells.

  15. Neurovirulence Mutant of Vesicular Stomatitis Virus with an Altered Target Cell Tropism In Vivo

    PubMed Central

    Preble, Olivia T.; Costello, Lauren E.; Huang, Diana D.; Barmada, Mamdouha A.

    1980-01-01

    Intracerebral infection of weanling Swiss mice with a temperature-sensitive (ts) mutant of vesicular stomatitis virus (VSV), ts pi364, resulted in a unique neuropathological syndrome not previously described with other VSV mutants. Mice infected with wild-type VSV died from an acute encephalitis characterized by neuronal necrosis and efficient virus replication in both brain and spinal cord. In contrast, with VSV ts pi364, the most prominent histopathological feature was destruction of the ependyma of the lateral ventricles. Virus antigen was also limited to the leptomeninges and the lateral ventricles. Infected mice survived and developed hydrocephalus. Replication of ts pi364 in the brain was 10- to 100- fold less than that of wild-type VSV, and appearance of virus in the spinal cord was delayed. VSV ts pi364 was isolated from mouse cells persistently infected with VSV. Another VSV ts pi mutant, isolated from the same persistent infection, behaved in vivo like wild-type VSV, even though both mutants were very similar in plaque size, reversion frequency, cut-off temperature, and synthesis of virus-specific proteins at semipermissive temperature. These results strongly suggest that VSV ts pi364 has a second, non-ts mutation which results in a restricted target cell range in vivo; wild-type VSV can infect both neurons and ependymal cells, whereas ts pi364 does not replicate in neurons. ImagesFig. 1Fig. 3Fig. 5Fig. 6 PMID:6163714

  16. Percutaneous Valve Replacement: Significance of Different Delivery Systems In Vitro and In Vivo

    SciTech Connect

    Attmann, Tim; Lutter, Georg Quaden, Rene; Jahnke, Thomas; Rumberg, Kristin; Cremer, Jochen; Muller-Hulsbeck, Stefan

    2006-06-15

    Background and purpose. Percutaneous heart valve replacement is an exciting growing field in cardiovascular medicine yet still with some major problems. Only sophisticated improvement of the instruments could make it a real alternative to conventional surgery. Therefore, the aim of this study was to evaluate different delivery devices for percutaneous heart valve replacement in vitro and in vivo. Methods. A catheter prototype designed by our group, and two commercially available devices for the delivery of esophageal stents and aortic endoprostheses, were tested. After in vitro experiments, an ovine animal model of transfemoral pulmonary valve implantation was established using biological valved self-expanding stents. Only the delivery device for aortic endografts (Medtronic, Talent, Santa Rosa, CA, USA) allowed fast in vitro procedures without material fatigue. This device was chosen for the in vivo tests. Results. Technical success was achieved in 9 of 10 animals (90%). One animal died after perforation of the ventricular wall. Orthotopic pulmonary placement was performed in 6 animals and intentional supravalvular valved stent placement in 3 animals. Conclusions. An adequate in vitro model for this evolving field of interventional heart valve replacement is presented. Furthermore, the present study pinpoints the key characteristics that are mandatory for a delivery system in percutaneous pulmonary valve implantation. With regard to the delivery device's ductility observed during this 'venous' study, an approach to transfemoral aortic valve implantation seems feasible.

  17. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, E.H.; Tuckerman, D.B.

    1991-09-10

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required. 1 figure.

  18. Die singulation method and package formed thereby

    SciTech Connect

    Anderson, Robert C.; Shul, Randy J.; Clews, Peggy J.; Baker, Michael S.; De Boer, Maarten P.

    2012-08-07

    A method is disclosed for singulating die from a substrate having a sacrificial layer and one or more device layers, with a retainer being formed in the device layer(s) and anchored to the substrate. Deep Reactive Ion Etching (DRIE) etching of a trench through the substrate from the bottom side defines a shape for each die. A handle wafer is then attached to the bottom side of the substrate, and the sacrificial layer is etched to singulate the die and to form a frame from the retainer and the substrate. The frame and handle wafer, which retain the singulated die in place, can be attached together with a clamp or a clip and to form a package for the singulated die. One or more stops can be formed from the device layer(s) to limit a sliding motion of the singulated die.

  19. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, Edward H.; Tuckerman, David B.

    1991-01-01

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required.

  20. Reinraumtechnik für die Medizintechnik

    NASA Astrophysics Data System (ADS)

    Petek, Max; Jungbluth, Martin; Krampe, Erhard

    Die Reinraumtechnik ist heute ein unverzichtbarer Bestandteil bei der Fertigung von Produkten der Life Sciences, den Bereichen Pharma, Lebensmittel, Kosmetik und Medizintechnik. In Anbetracht der langen Historie der Medizintechnik ist sie jedoch eine sehr junge Disziplin. Die Bedeutung von Keimen und die richtige Einschätzung ihrer Größe wurden zwar sehr früh bereits durch Paracelsus erkannt, jedoch wurden daraus noch keine speziellen oder kontinuierlich umgesetzten Hygienevorschriften abgeleitet. Die erste bekannte technische Umsetzung von Hygieneempfehlungen geht auf den Franzosen François Nicolas Appert zurück, der eine aseptische Abfüllmethode für Lebensmittel entwickelte und diese 1810 veröffentlichte [1]. Die erste dokumentierte medizinische Umsetzung stellten Hygienevorschriften für Ärzte dar, die Ignaz Philipp Semmelweis nach 1847 in der Wiener Klinik für Geburtshilfe einführte [2].

  1. Should assisted dying be legalised?

    PubMed Central

    2014-01-01

    When an individual facing intractable pain is given an estimate of a few months to live, does hastening death become a viable and legitimate alternative for willing patients? Has the time come for physicians to do away with the traditional notion of healthcare as maintaining or improving physical and mental health, and instead accept their own limitations by facilitating death when requested? The Universities of Oxford and Cambridge held the 2013 Varsity Medical Debate on the motion “This House Would Legalise Assisted Dying”. This article summarises the key arguments developed over the course of the debate. We will explore how assisted dying can affect both the patient and doctor; the nature of consent and limits of autonomy; the effects on society; the viability of a proposed model; and, perhaps most importantly, the potential need for the practice within our current medico-legal framework. PMID:24423249

  2. Comparison of sequential drug release in vitro and in vivo.

    PubMed

    Sundararaj, Sharath C; Al-Sabbagh, Mohanad; Rabek, Cheryl L; Dziubla, Thomas D; Thomas, Mark V; Puleo, David A

    2016-10-01

    Development of drug-delivery devices typically involves characterizing in vitro release performance with the inherent assumption that this will closely approximate in vivo performance. Yet, as delivery devices become more complex, for instance with a sequential drug release pattern, it is important to confirm that in vivo properties correlate with the expected "programming" achieved in vitro. In this work, a systematic comparison between in vitro and in vivo biomaterial erosion and sequential release was performed for a multilayered association polymer system comprising cellulose acetate phthalate and Pluronic F-127. After assessing the materials during incubation in phosphate-buffered saline, devices were implanted supracalvarially in rats. Devices with two different doses and with different erosion rates were harvested at increasing times post-implantation, and the in vivo thickness loss, mass loss, and the drug release profiles were compared with their in vitro counterparts. The sequential release of four different drugs observed in vitro was successfully translated to in vivo conditions. Results suggest, however, that the total erosion time of the devices was longer and that release rates of the four drugs were different, with drugs initially released more quickly and then more slowly in vivo. Many comparative studies of in vitro and in vivo drug release from biodegradable polymers involved a single drug, whereas this research demonstrated that sequential release of four drugs can be maintained following implantation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1302-1310, 2016.

  3. In Vivo Metal Ion Imaging Using Fluorescent Sensors.

    PubMed

    Van de Bittner, Genevieve C; Hirayama, Tasuku

    2016-01-01

    In vivo imaging in living animals provides the ability to monitor alterations of signaling molecules, ions, and other biological components during various life stages and in disease. The data gained from in vivo imaging can be used for biological discovery or to determine elements of disease progression and can inform the development and translation of therapeutics. Herein, we present theories behind small-molecule, fluorescent, metal ion sensors as well as the methods for their successful application to in vivo metal ion imaging, including ex vivo validation. PMID:27283424

  4. Label-free optical activation of astrocyte in vivo

    NASA Astrophysics Data System (ADS)

    Choi, Myunghwan; Yoon, Jonghee; Ku, Taeyun; Choi, Kyungsun; Choi, Chulhee

    2011-07-01

    As the most abundant cell type in the central nervous system, astrocyte has been one of main research topics in neuroscience. Although various tools have been developed, at present, there is no tool that allows noninvasive activation of astrocyte in vivo without genetic or pharmacological perturbation. Here we report a noninvasive label-free optical method for physiological astrocyte activation in vivo using a femtosecond pulsed laser. We showed the laser stimulation robustly induced astrocytic calcium activation in vivo and further verified physiological relevance of the calcium increase by demonstrating astrocyte mediated vasodilation in the brain. This novel optical method will facilitate noninvasive physiological study on astrocyte function.

  5. Plasma and Cavitation Dynamics during Pulsed Laser Microsurgery in vivo

    SciTech Connect

    Hutson, M. Shane; Ma Xiaoyan

    2007-10-12

    We compare the plasma and cavitation dynamics underlying pulsed laser microsurgery in water and in fruit fly embryos (in vivo)--specifically for nanosecond pulses at 355 and 532 nm. We find two key differences. First, the plasma-formation thresholds are lower in vivo --especially at 355 nm--due to the presence of endogenous chromophores that serve as additional sources for plasma seed electrons. Second, the biological matrix constrains the growth of laser-induced cavitation bubbles. Both effects reduce the disrupted region in vivo when compared to extrapolations from measurements in water.

  6. Sequestrated Thrombolysis: Comparative Evaluation In Vivo

    SciTech Connect

    Roy, Sumit; Laerum, Frode; Brosstad, Frank; Kvernebo, Knut; Sakariassen, Kjell S.

    2000-03-15

    Purpose: Lysis of a thrombus is a function of the local concentration of thrombolytic enzymes. This study was designed to determine in a porcine model of acute deep vein thrombosis (DVT) whether perithrombic sequestration of small volumes of a concentrated enzyme solution can accelerate the process of thrombolysis.Methods: DVT was induced in both hind limbs using a previously described technique (n = 32). Thirty minutes later the animal was heparinized and unilateral thrombolysis was attempted using 8 mg recombinant tissue plasminogen activator (rt-PA); saline was administered in the opposite leg. For conventional high-volume infusion (CI) (n = 5) rt-PA (0.067 mg/ml) was infused at 1 ml/min. For sequestrated thrombolysis the external iliac vein was endoluminally occluded, and rt-PA (0.25 mg/ml) administered either for proximal injection (ST-P) (n = 5), as a bolus every 3 min through a microcatheter placed via the balloon catheter, or for transthrombic injection (ST-T) (n = 5), as a bolus every 3 min through a Katzen wire in the balloon catheter. At autopsy, the thrombus mass in the iliofemoral veins was measured, and the extent of residual thrombosis in the venous tributaries graded at four sites. From these data a thrombolysis score was calculated.Results: One pig died before thrombolysis could be performed. Only with ST-T was residual thrombus mass in the test limb normalized to control, residual thrombus index (RTI), consistently less than unity. The median RTI of this group was 0.50 (range 0.39-0.97) compared with 1.22 (0.64-1.38) for ST-P and 0.88 (0.37-1.13) for CI. Compared with contralateral controls, a lower grade of residual thrombosis in tributaries was observed in test limbs at more venous sites with ST-T (8/20; 95% confidence interval 5-13) and ST-P (9/20; confidence interval 5-13) than with CI (2/20; confidence interval 0-5) (p= 0.04). A trend toward lower thrombolysis scores was observed with ST-T (p = 0.08). Systemic fibrinogenolysis was not

  7. Elevated in vivo strontium-90 from nuclear weapons test fallout among cancer decedents: a case-control study of deciduous teeth.

    PubMed

    Mangano, Joseph J; Sherman, Janette D

    2011-01-01

    Risks to health from large-scale atmospheric nuclear weapons testing are still relatively unknown. A sample of 85,000 deciduous teeth collected from Americans born during the bomb-testing years assessed risk by in vivo measurement of residual strontium-90 (Sr-90) concentrations, using liquid scintillation spectrometry. The authors' analysis included 97 deciduous teeth from persons born between 1959 and 1961 who were diagrosed with cancer, and 194 teeth of matched controls. Average Sr-90 in teeth of persons who died of cancer was significantly greater than for controls (OR = 2.22; p < 0.04). This discovery suggests that many thousands have died or will die of cancer due to exposure to fallout, far more than previously believed.

  8. Insights on TRP Channels from In Vivo Studies in Drosophila

    PubMed Central

    Minke, Baruch; Parnas, Moshe

    2007-01-01

    Transient receptor potential (TRP) channels mediate responses in a large variety of signaling mechanisms. Most studies on mammalian TRP channels rely on heterologous expression, but their relevance to in vivo tissues is not entirely clear. In contrast, Drosophila TRP and TRP-like (TRPL) channels allow direct analyses of in vivo function. In Drosophila photoreceptors, activation of TRP and TRPL is mediated via the phosphoinositide cascade, with both Ca2+ and diacylglycerol (DAG) essential for generating the light response. In tissue culture cells, TRPL channels are constitutively active, and lipid second messengers greatly facilitate this activity. Inhibition of phospholipase C (PLC) completely blocks lipid activation of TRPL, suggesting that lipid activation is mediated via PLC. In vivo studies in mutant Drosophila also reveal an acute requirement for lipid-producing enzyme, which may regulate PLC activity. Thus, PLC and its downstream second messengers, Ca2+ and DAG, constitute critical mediators of TRP/TRPL gating in vivo. PMID:16460287

  9. Selected recent in vivo studies on chemical measurements in invertebrates.

    PubMed

    Majdi, S; Ren, L; Fathali, H; Li, X; Ewing, A G

    2015-06-01

    In vivo measurements of neurotransmitters and related compounds have provided a better understanding of the chemical interactions that are a major part in functioning of brains. In addition, a great deal of technology has been developed to measure chemical species in other areas of living organisms. A key part of this work has been sampling technologies as well as direct measurements in vivo. This is extremely important when sampling from the smallest animal systems. Yet, very small invertebrate systems are excellent models and often have better defined and more easily manipulated genetics. This review focuses on in vivo measurements, electrochemical methods, fluorescence techniques, and sampling and is further narrowed to work over approximately the last three years. Rapid developments of in vivo studies in these model systems should aid in finding solutions to biological and bioanalytical challenges related to human physiological functions and neurodegenerative diseases.

  10. In vivo spectral micro-imaging of tissue

    SciTech Connect

    Demos, Stavros G; Urayama, Shiro; Lin, Bevin; Saroufeem, Ramez; Ghobrial, Moussa

    2012-11-27

    In vivo endoscopic methods an apparatuses for implementation of fluorescence and autofluorescence microscopy, with and without the use of exogenous agents, effectively (with resolution sufficient to image nuclei) visualize and categorize various abnormal tissue forms.

  11. Advances in measuring single-cell pharmacology in vivo.

    PubMed

    Vinegoni, Claudio; Dubach, J Matthew; Thurber, Greg M; Miller, Miles A; Mazitschek, Ralph; Weissleder, Ralph

    2015-09-01

    Measuring key pharmacokinetic and pharmacodynamic parameters in vivo at the single cell level is likely to enhance drug discovery and development. In this review, we summarize recent advances in this field and highlight current and future capabilities. PMID:26024776

  12. Reactive polymer enables efficient in vivo bioorthogonal chemistry

    PubMed Central

    Devaraj, Neal K.; Thurber, Greg M.; Keliher, Edmund J.; Marinelli, Brett; Weissleder, Ralph

    2012-01-01

    There has been intense interest in the development of selective bioorthogonal reactions or “click” chemistry that can proceed in live animals. Until now however, most reactions still require vast surpluses of reactants because of steep temporal and spatial concentration gradients. Using computational modeling and design of pharmacokinetically optimized reactants, we have developed a predictable method for efficient in vivo click reactions. Specifically, we show that polymer modified tetrazines (PMT) are a key enabler for in vivo bioorthogonal chemistry based on the very fast and catalyst-free [4 + 2] tetrazine/trans-cyclooctene cycloaddition. Using fluorescent PMT for cellular resolution and 18F labeled PMT for whole animal imaging, we show that cancer cell epitopes can be easily reacted in vivo. This generic strategy should help guide the design of future chemistries and find widespread use for different in vivo bioorthogonal applications, particularly in the biomedical sciences. PMID:22411831

  13. Reactive polymer enables efficient in vivo bioorthogonal chemistry.

    PubMed

    Devaraj, Neal K; Thurber, Greg M; Keliher, Edmund J; Marinelli, Brett; Weissleder, Ralph

    2012-03-27

    There has been intense interest in the development of selective bioorthogonal reactions or "click" chemistry that can proceed in live animals. Until now however, most reactions still require vast surpluses of reactants because of steep temporal and spatial concentration gradients. Using computational modeling and design of pharmacokinetically optimized reactants, we have developed a predictable method for efficient in vivo click reactions. Specifically, we show that polymer modified tetrazines (PMT) are a key enabler for in vivo bioorthogonal chemistry based on the very fast and catalyst-free [4 + 2] tetrazine/trans-cyclooctene cycloaddition. Using fluorescent PMT for cellular resolution and (18)F labeled PMT for whole animal imaging, we show that cancer cell epitopes can be easily reacted in vivo. This generic strategy should help guide the design of future chemistries and find widespread use for different in vivo bioorthogonal applications, particularly in the biomedical sciences. PMID:22411831

  14. The Expanding Toolbox of In Vivo Bioluminescent Imaging.

    PubMed

    Xu, Tingting; Close, Dan; Handagama, Winode; Marr, Enolia; Sayler, Gary; Ripp, Steven

    2016-01-01

    In vivo bioluminescent imaging (BLI) permits the visualization of engineered bioluminescence from living cells and tissues to provide a unique perspective toward the understanding of biological processes as they occur within the framework of an authentic in vivo environment. The toolbox of in vivo BLI includes an inventory of luciferase compounds capable of generating bioluminescent light signals along with sophisticated and powerful instrumentation designed to detect and quantify these light signals non-invasively as they emit from the living subject. The information acquired reveals the dynamics of a wide range of biological functions that play key roles in the physiological and pathological control of disease and its therapeutic management. This mini review provides an overview of the tools and applications central to the evolution of in vivo BLI as a core technology in the preclinical imaging disciplines. PMID:27446798

  15. A method to study in vivo stability of DNA nanostructures☆

    PubMed Central

    Surana, Sunaina; Bhatia, Dhiraj; Krishnan, Yamuna

    2013-01-01

    DNA nanostructures are rationally designed, synthetic, nanoscale assemblies obtained from one or more DNA sequences by their self-assembly. Due to the molecularly programmable as well as modular nature of DNA, such designer DNA architectures have great potential for in cellulo and in vivo applications. However, demonstrations of functionality in living systems necessitates a method to assess the in vivo stability of the relevant nanostructures. Here, we outline a method to quantitatively assay the stability and lifetime of various DNA nanostructures in vivo. This exploits the property of intact DNA nanostructures being uptaken by the coelomocytes of the multicellular model organism Caenorhabditis elegans. These studies reveal that the present fluorescence based assay in coelomocytes of C. elegans is an useful in vivo test bed for measuring DNA nanostructure stability. PMID:23623822

  16. The Expanding Toolbox of In Vivo Bioluminescent Imaging

    PubMed Central

    Xu, Tingting; Close, Dan; Handagama, Winode; Marr, Enolia; Sayler, Gary; Ripp, Steven

    2016-01-01

    In vivo bioluminescent imaging (BLI) permits the visualization of engineered bioluminescence from living cells and tissues to provide a unique perspective toward the understanding of biological processes as they occur within the framework of an authentic in vivo environment. The toolbox of in vivo BLI includes an inventory of luciferase compounds capable of generating bioluminescent light signals along with sophisticated and powerful instrumentation designed to detect and quantify these light signals non-invasively as they emit from the living subject. The information acquired reveals the dynamics of a wide range of biological functions that play key roles in the physiological and pathological control of disease and its therapeutic management. This mini review provides an overview of the tools and applications central to the evolution of in vivo BLI as a core technology in the preclinical imaging disciplines. PMID:27446798

  17. Metallomics insights for in vivo studies of metal based nanomaterials.

    PubMed

    Wang, Bing; Feng, Weiyue; Zhao, Yuliang; Chai, Zhifang

    2013-06-01

    With the rapid development of engineered nanomaterials (NMs) and wide biomedical applications for new types of multifunctional NMs, an understanding of the behavior patterns of NMs in vivo and clarification of their potential health impact as a result of their novel physicochemical properties is essential for ensuring safety in biomedical applications of nanotechnology. NMs have heterogeneous characteristics in that they combine the bulk properties of solids with the mobility of molecules, and present phase transformation, dissolution, oxidation/reduction as well as nano-bio interface reactions in biological milieu, which affect their in vivo behaviors and biological effects. The accurate study of identification, quantification, transformation state of NMs and their biological effects in vivo remains a challenge. This review aims to provide a "metallomics" (an integrated metal-assisted function bioscience) insight into the in vivo behavior and biological effects of NMs, particularly for metal-based nanomaterials (MNMs) and is based mainly on our own research and other previous works.

  18. Imaging agents for in vivo magnetic resonance and scintigraphic imaging

    DOEpatents

    Engelstad, Barry L.; Raymond, Kenneth N.; Huberty, John P.; White, David L.

    1991-01-01

    Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided.

  19. Imaging agents for in vivo magnetic resonance and scintigraphic imaging

    DOEpatents

    Engelstad, B.L.; Raymond, K.N.; Huberty, J.P.; White, D.L.

    1991-04-23

    Methods are provided for in vivo magnetic resonance imaging and/or scintigraphic imaging of a subject using chelated transition metal and lanthanide metal complexes. Novel ligands for these complexes are provided. No Drawings

  20. Student Nurses' Perception of Death and Dying

    ERIC Educational Resources Information Center

    Niederriter, Joan E.

    2009-01-01

    Student nurses are involved in caring for patients who are actively dying or who have been told they have a terminal illness and are faced with the process of dying. Students encounter these patients in hospitals, nursing homes, at home or in hospice care settings. According to Robinson (2004), "nurses are the healthcare providers that are most…

  1. Energy Consumption of Die Casting Operations

    SciTech Connect

    Jerald Brevick; clark Mount-Campbell; Carroll Mobley

    2004-03-15

    Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.

  2. Apparatus for restraining and transporting dies

    DOEpatents

    Allison, James W.; LaBarre, Timothy L.

    1994-01-01

    Apparatus for restraining and transporting dies in punch press operations is provided. A floatation platen for supporting a die on the platen's upper surface has a plurality of recessed gas exhaust ports on the platen's lower surface. A source of pressurized gas delivers gas to a platen manifold, for delivery to orifices located in the gas exhaust ports. The flow of gas is controlled by a first valve adjacent the gas source and a second valve adjacent the manifold, with the second valve being used to control the gas flow during movement of the die. In this fashion, a die may be moved on a cushion of air from one workstation to a selected second workstation. A moveable hydraulically operated restraining fixture is also provided, for clamping the die in position during the compacting phase, and for releasing the die after completion of the compacting phase by releasing the hydraulic pressure on the restraining fixture. When pressure in the hydraulic cylinders on the restraining fixture is reversed, the restraining fixture will retract so that there is no contact between the die and the restraining fixture, thereby allowing the die to be removed from a first workstation and moved to a second selected workstation.

  3. Prediction of Part Distortion in Die Casting

    SciTech Connect

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  4. Assisted dying: a review of international legislation.

    PubMed

    Field, Charlotte; Curtice, Martin

    2009-05-01

    The issue of assisted dying in the UK is increasingly receiving media and academic journal attention. Such reporting often cites, but in little depth, existing legislation in other countries. Such international legislation may also shape future UK assisted dying legislation. PMID:19451872

  5. The Right To Die. Public Talk Series.

    ERIC Educational Resources Information Center

    Pasquerella, Lynn

    This program guide on the right to die provides policy issue information where ethical concerns have a prominent place. Three positions about the right to die are presented: (1) mercy killing and assisted suicide should be legally permitted in certain cases; (2) legal status should be given to living wills and other advance directives that would…

  6. Portable optical fiber probe for in vivo brain temperature measurements.

    PubMed

    Musolino, Stefan; Schartner, Erik P; Tsiminis, Georgios; Salem, Abdallah; Monro, Tanya M; Hutchinson, Mark R

    2016-08-01

    This work reports on the development of an optical fiber based probe for in vivo measurements of brain temperature. By utilizing a thin layer of rare-earth doped tellurite glass on the tip of a conventional silica optical fiber a robust probe, suitable for long-term in vivo measurements of temperature can be fabricated. This probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories.

  7. In vivo decomposition study of coated magnesium alloys

    NASA Astrophysics Data System (ADS)

    White, Desiree; Piersma, Tyler; Lecronier, David; Cheng, Xingguo; Rabago-Smith, Montserrat

    2010-04-01

    In the last decade, magnesium has resurged as an important biomaterial. Its mechanical properties are very similar to natural bone, and it degrades in vivo to non toxic substances. Unfortunately, corrosion of pure magnesium in vivo is rapid, thus coated alloys that decrease its corrosion could be used as implants in orthopedics. This presentation will describe the degradation results in cell cultures and in rats.

  8. Portable optical fiber probe for in vivo brain temperature measurements

    PubMed Central

    Musolino, Stefan; Schartner, Erik P.; Tsiminis, Georgios; Salem, Abdallah; Monro, Tanya M.; Hutchinson, Mark R.

    2016-01-01

    This work reports on the development of an optical fiber based probe for in vivo measurements of brain temperature. By utilizing a thin layer of rare-earth doped tellurite glass on the tip of a conventional silica optical fiber a robust probe, suitable for long-term in vivo measurements of temperature can be fabricated. This probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories. PMID:27570698

  9. Monitoring Retroviral RNA Dimerization In Vivo via Hammerhead Ribozyme Cleavage

    PubMed Central

    Pal, Bijay K.; Scherer, Lisa; Zelby, Laurie; Bertrand, Edouard; Rossi, John J.

    1998-01-01

    We have used a strategy for colocalization of Psi (Ψ)-tethered ribozymes and targets to demonstrate that Ψ sequences are capable of specific interaction in the cytoplasm of both packaging and nonpackaging cells. These results indicate that current in vitro dimerization models may have in vivo counterparts. The methodology used may be applied to further genetic analyses on Ψ domain interactions in vivo. PMID:9733882

  10. Portable optical fiber probe for in vivo brain temperature measurements.

    PubMed

    Musolino, Stefan; Schartner, Erik P; Tsiminis, Georgios; Salem, Abdallah; Monro, Tanya M; Hutchinson, Mark R

    2016-08-01

    This work reports on the development of an optical fiber based probe for in vivo measurements of brain temperature. By utilizing a thin layer of rare-earth doped tellurite glass on the tip of a conventional silica optical fiber a robust probe, suitable for long-term in vivo measurements of temperature can be fabricated. This probe can be interrogated using a portable optical measurement setup, allowing for measurements to be performed outside of standard optical laboratories. PMID:27570698

  11. Automatic in vivo portal dosimetry of all treatments

    NASA Astrophysics Data System (ADS)

    Olaciregui-Ruiz, I.; Rozendaal, R.; Mijnheer, B.; van Herk, M.; Mans, A.

    2013-11-01

    At our institution EPID (electronic portal imaging device) dosimetry is routinely applied to perform in vivo dose verification of all patient treatments with curative intent since January 2008. The major impediment of the method has been the amount of work required to produce and inspect the in vivo dosimetry reports (a time-consuming and labor-intensive process). In this paper we present an overview of the actions performed to implement an automated in vivo dosimetry solution clinically. We reimplemented the EPID dosimetry software and modified the acquisition software. Furthermore, we introduced new tools to periodically inspect the record-and-verify database and automatically run the EPID dosimetry software when needed. In 2012, 95% of our 3839 treatments scheduled for in vivo dosimetry were analyzed automatically (27 633 portal images of intensity-modulated radiotherapy (IMRT) fields, 5551 portal image data of VMAT arcs, and 2003 portal images of non-IMRT fields). The in vivo dosimetry verification results are available a few minutes after delivery and alerts are immediately raised when deviations outside tolerance levels are detected. After the clinical introduction of this automated solution, inspection of the detected deviations is the only remaining work. These newly developed tools are a major step forward towards full integration of in vivo EPID dosimetry in radiation oncology practice.

  12. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    SciTech Connect

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  13. Goethe almost died of urosepsis.

    PubMed

    Gross, A J; Hummel, G

    1999-12-01

    In the year of 1805, Goethe almost died of urosepsis. His urological problems were not diseases arising from full health but a new variation in a life accompanied by illnesses. Some sources date the first colics he experienced to the year 1795 and others say 1805. The most dramatic period in the course of his illness was in February, when he suffered from fever of such an extent that one could speak of urosepsis. Recovery took place slowly and was accompanied by minor relapses. Nothing about this is written down in his work. On the advice of his doctors, Goethe undertook a cure in Lauchstädt in July and August. The report of his consultant, Professor Johann Christian Reil, on his problems in the field of urology remained undiscovered until 1937. Professor Reil recommended treatment with thermae carolinae, aqua calcis, soap soda crystallisata, herbae subastringentes, and uva ursi, among other measures. With increasing age, Goethe's colics disappeared. The passing of a stone has never been described. Whereas Goethe hinted about medical problem other than those reported herein, the urological problems discussed in this article were left unmentioned. Nonetheless, literature that deals with Goethe's diseases is interesting from the aspect of both the history of medicine and the history of culture.

  14. Dying to go to school.

    PubMed

    Shearar, A

    1997-01-01

    In southern Sudan, the recent war sparked a mass migration of boys aged 5-18 who traveled through perilous terrain to the borders of Ethiopia in search of promised security and schooling. Thousands of these children died from hardships suffered in the wild, from the inadvertent or deliberate attacks of warriors, from hunger, from thirst, or from disease. Those who endured the hardships and arrived at their destination were shocked to find only military training centers or rudimentary schooling for those who were too weak or too young to be trained for battle. Eventually, the refugees were forced back into Sudan, and today about 20,000 of these unaccompanied children are displaced. Several nongovernmental organizations are running family reunification projects, and follow-up activities carried out among the reunified children reveal that they carry the scars of their trauma. The drawings the children produce as art therapy usually include the image of a young child holding a school book. While these children have a constant struggle with their memories, those who have not returned home or who have lost their families to war or disease are even more forlorn. As food rations have been halved in the refugee camps, many children are pursuing any possible alternative living arrangement. Some attempt to travel to South Africa or Egypt and some join an army in an effort to overcome the desperation of their present situation. PMID:12294200

  15. In vivo imaging of microscopic structures in the rat retina

    PubMed Central

    Geng, Ying; Greenberg, Kenneth P.; Wolfe, Robert; Gray, Daniel C.; Hunter, Jennifer J.; Dubra, Alfredo; Flannery, John G.; Williams, David R.; Porter, Jason

    2010-01-01

    Purpose The ability to resolve single retinal cells in rodents in vivo has applications in rodent models of the visual system and retinal disease. We have characterized the performance of a fluorescence adaptive optics scanning laser ophthalmoscope (fAOSLO) that provides cellular and subcellular imaging of rat retina in vivo. Methods Green fluorescent protein (eGFP) was expressed in retinal ganglion cells of normal Sprague Dawley rats via intravitreal injections of adeno-associated viral vectors. Simultaneous reflectance and fluorescence retinal images were acquired using the fAOSLO. fAOSLO resolution was characterized by comparing in vivo images with subsequent imaging of retinal sections from the same eyes using confocal microscopy. Results Retinal capillaries and eGFP-labeled ganglion cell bodies, dendrites, and axons were clearly resolved in vivo with adaptive optics (AO). AO correction reduced the total root mean square wavefront error, on average, from 0.30 μm to 0.05 μm (1.7-mm pupil). The full width at half maximum (FWHM) of the average in vivo line-spread function (LSF) was ∼1.84 μm, approximately 82% greater than the FWHM of the diffraction-limited LSF. Conclusions With perfect aberration compensation, the in vivo resolution in the rat eye could be ∼2× greater than that in the human eye due to its large numerical aperture (∼0.43). While the fAOSLO corrects a substantial fraction of the rat eye's aberrations, direct measurements of retinal image quality reveal some blur beyond that expected from diffraction. Nonetheless, subcellular features can be resolved, offering promise for using AO to investigate the rodent eye in vivo with high resolution. PMID:19578019

  16. In Vivo Delivery of Nucleic Acids via Glycopolymer Vehicles Affords Therapeutic Infarct Size Reduction In Vivo

    PubMed Central

    Tranter, Michael; Liu, Yemin; He, Suiwen; Gulick, James; Ren, Xiaoping; Robbins, Jeffrey; Jones, W. Keith; Reineke, Theresa M.

    2012-01-01

    Using a new class of nontoxic and degradable glycopolymer-based vehicles termed poly(glycoamidoamine)s, we demonstrate virus-like delivery efficacy of oligodeoxynucleotide (ODN) decoys to cardiomyoblasts (H9c2), primary cardiomyocytes, and the mouse heart. These glycopolymers bind and compact ODN decoys into nanoparticle complexes that are internalized by the cell membrane and mediate nuclear uptake of DNA in 90+% of cultured primary cardiomyocytes and 87% of the mouse myocardium. Experimental results reveal that decoys delivered via these glycopolymers block the activation of the transcription factor NF-κB, a major contributor to ischemia/reperfusion injury. Decoy complexes formed with glycopolymer T4 significantly blocked downstream gene expression of Cox-2 and limited myocardial infarction in vivo, phenocopying a transgenic mouse model. These promising delivery vehicles may facilitate high-throughput genetic approaches in animal models. Additionally, the low toxicity, biodegradation, and outstanding delivery efficacy suggest that these nanomedicines may be clinically applicable for gene regulatory therapy. PMID:22186793

  17. Reproduction of in vivo motion using a parallel robot.

    PubMed

    Howard, Ryan A; Rosvold, Joshua M; Darcy, Shon P; Corr, David T; Shrive, Nigel G; Tapper, Janet E; Ronsky, Janet L; Beveridge, Jillian E; Marchuk, Linda L; Frank, Cyril B

    2007-10-01

    Although alterations in knee joint loading resulting from injury have been shown to influence the development of osteoarthritis, actual in vivo loading conditions of the joint remain unknown. A method for determining in vivo ligament loads by reproducing joint specific in vivo kinematics using a robotic testing apparatus is described. The in vivo kinematics of the ovine stifle joint during walking were measured with 3D optical motion analysis using markers rigidly affixed to the tibia and femur. An additional independent single degree of freedom measuring device was also used to record a measure of motion. Following sacrifice, the joint was mounted in a robotic/universal force sensor test apparatus and referenced using a coordinate measuring machine. A parallel robot configuration was chosen over the conventional serial manipulator because of its greater accuracy and stiffness. Median normal gait kinematics were applied to the joint and the resulting accuracy compared. The mean error in reproduction as determined by the motion analysis system varied between 0.06 mm and 0.67 mm and 0.07 deg and 0.74 deg for the two individual tests. The mean error measured by the independent device was found to be 0.07 mm and 0.83 mm for the two experiments, respectively. This study demonstrates the ability of this system to reproduce in vivo kinematics of the ovine stifle joint in vitro. The importance of system stiffness is discussed to ensure accurate reproduction of joint motion. PMID:17887900

  18. Systemic inflammation regulates microglial responses to tissue damage in vivo

    PubMed Central

    Gyoneva, Stefka; Davalos, Dimitrios; Biswas, Dipankar; Swanger, Sharon A.; Garnier-Amblard, Ethel; Loth, Francis; Akassoglou, Katerina; Traynelis, Stephen F.

    2015-01-01

    Microglia, the resident immune cells of the central nervous system, exist in either a “resting” state associated with physiological tissue surveillance or an “activated” state in neuroinflammation. We recently showed that ATP is the primary chemoattractor to tissue damage in vivo and elicits opposite effects on the motility of activated microglia in vitro through activation of adenosine A2A receptors. However, whether systemic inflammation affects microglial responses to tissue damage in vivo remains largely unknown. Using in vivo two-photon imaging of mice, we show that injection of lipopolysaccharide (LPS) at levels that can produce both clear neuroinflammation and some features of sepsis significantly reduced the rate of microglial response to laser-induced ablation injury in vivo. Under pro-inflammatory conditions, microglial processes initially retracted from the ablation site, but subsequently moved toward and engulfed the damaged area. Analyzing the process dynamics in 3D cultures of primary microglia indicated that only A2A, but not A1 or A3 receptors, mediate process retraction in LPS-activated microglia. The A2A receptor antagonists caffeine and preladenant reduced adenosine-mediated process retraction in activated microglia in vitro. Finally, administration of preladenant before induction of laser ablation in vivo accelerated the microglial response to injury following systemic inflammation. The regulation of rapid microglial responses to sites of injury by A2A receptors could have implications for their ability to respond to the neuronal death occurring under conditions of neuroinflammation in neurodegenerative disorders. PMID:24807189

  19. In Vivo Programmed Gene Expression Based on Artificial Quorum Networks

    PubMed Central

    Chu, Teng; Huang, Yajun; Hou, Mingyu; Wang, Qiyao; Xiao, Jingfan; Zhang, Yuanxing

    2015-01-01

    The quorum sensing (QS) system, as a well-functioning population-dependent gene switch, has been widely applied in many gene circuits in synthetic biology. In our work, an efficient cell density-controlled expression system (QS) was established via engineering of the Vibrio fischeri luxI-luxR quorum sensing system. In order to achieve in vivo programmed gene expression, a synthetic binary regulation circuit (araQS) was constructed by assembling multiple genetic components, including the quorum quenching protein AiiA and the arabinose promoter ParaBAD, into the QS system. In vitro expression assays verified that the araQS system was initiated only in the absence of arabinose in the medium at a high cell density. In vivo expression assays confirmed that the araQS system presented an in vivo-triggered and cell density-dependent expression pattern. Furthermore, the araQS system was demonstrated to function well in different bacteria, indicating a wide range of bacterial hosts for use. To explore its potential applications in vivo, the araQS system was used to control the production of a heterologous protective antigen in an attenuated Edwardsiella tarda strain, which successfully evoked efficient immune protection in a fish model. This work suggested that the araQS system could program bacterial expression in vivo and might have potential uses, including, but not limited to, bacterial vector vaccines. PMID:25979894

  20. Die Evolution des Universums. Eine Geschichte der Kosmologie.

    NASA Astrophysics Data System (ADS)

    Hiller, H.

    This volume covers in an elementary course a historical overview on cosmology ranging from the ancient aspects up to big bang theory and the concepts of inflationary universe and grand unified theories. Contents: 1. Auf dem Wege zur Wissenschaft. 2. Die neue Kosmologie. 3. Die Struktur des Weltalls. 4. Dramatik im Weltall. 5. Die endliche Welt. 6. Die Evolution des frühen Universums. 7. Die Zukunft. 8. Die neue Teleologie. 9. Das Leben.

  1. CEU your jewish patient is dying....

    PubMed

    Schwartz, E A

    1989-01-01

    This article offers the nurse information needed for planning the care of Jewish patients and their families during the dying and mourning process - whether that patient is Orthodox, Conservative, or Reform.

  2. Casting Characteristics of Aluminum Die Casting Alloys

    SciTech Connect

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

  3. Supporting dignified dying in the Philippines

    PubMed Central

    Doorenbos, Ardith Z; Abaquin, Carmencita; Perrin, Margot E; Eaton, Linda; Balabagno, Araceli O; Rue, Tessa; Ramos, Rita

    2011-01-01

    Purpose This study aimed to assess the appropriateness of the International Classification for Nursing Practice (ICNP) Palliative Care for Dignified Dying catalogue for palliative nursing in the Philippines. Methods The study recruited 230 nurses to complete the ICNP Dignified Dying survey. Participants rated ICNP nursing intervention items and identified additional interventions for promoting dignified dying. Results All of the intervention items were scored on average as being at least ‘slightly important’. The three top-ranked nursing intervention categories were providing social support, maintaining privacy boundaries, and relieving psychological distress. Conclusions The ICNP Palliative Care for Dignified Dying catalogue lists nursing interventions that are appropriate to promoting dignity at the end of life in the Philippines. PMID:21471908

  4. Is there a moral duty to die?

    PubMed

    Corlett, J A

    2001-01-01

    In recent years, there has been a great deal of philosophical discussion about the alleged moral right to die. If there is such a moral right, then it would seem to imply a moral duty of others to not interfere with the exercise of the right. And this might have important implications for public policy insofar as public policy ought to track what is morally right. But is there a moral duty to die? If so, under what conditions, if any, ought one to have such a duty, and why? In this paper, I distinguish between different moral grounds for the putative moral duty to die: deontological, intuitionist, and contractarian. Subsequently, I argue in support of Paul Menzel's theory of health care distribution. More precisely, I concur with his claim that there is a moral duty to die inexpensively in health care contexts. Then I provide and defend a philosophical analysis of the conditions in which such a duty could exist.

  5. Understanding Dying Patients and Their Families

    PubMed Central

    Librach, S.L.; Talbot, Yves

    1991-01-01

    Caring for dying patients and their families presents unique opportunities and challenges for the family physician. The family FIRO model provides a simple way of assessing families and providing appropriate, individualized care. This article outlines the model, discusses the care of dying patients and their families from the FIRO perspective, and provides a guideline for the family physician. A framework is suggested for teaching residents to support families. PMID:21228989

  6. Machining of Silicon-Ribbon-Forming Dies

    NASA Technical Reports Server (NTRS)

    Menna, A. A.

    1985-01-01

    Carbon extension for dies used in forming silicon ribbon crystals machined precisely with help of special tool. Die extension has edges beveled toward narrow flats at top, with slot precisely oriented and centered between flats and bevels. Cutting tool assembled from standard angle cutter and circular saw or saws. Angle cutters cuts bevels while slot saw cuts slot between them. In alternative version, custom-ground edges or additional circular saws also cut flats simultaneously.

  7. Thick film silicon growth techniques. [die materials

    NASA Technical Reports Server (NTRS)

    Bates, H. E.; Mlavsky, A. I.; Jewett, D. N.; White, V. E.

    1973-01-01

    The research which was directed toward finding an improved die material is reported. Wetting experiments were conducted with various materials to determine their compatibility with silicon. Work has also continued toward the development of quartz as a die material as new techniques have provided more optimistic results than observed in the past. As a result of the thermal modification previously described, improvements in growth stability have contributed to an increase in ribbon quality.

  8. Favipiravir elicits antiviral mutagenesis during virus replication in vivo.

    PubMed

    Arias, Armando; Thorne, Lucy; Goodfellow, Ian

    2014-01-01

    Lethal mutagenesis has emerged as a novel potential therapeutic approach to treat viral infections. Several studies have demonstrated that increases in the high mutation rates inherent to RNA viruses lead to viral extinction in cell culture, but evidence during infections in vivo is limited. In this study, we show that the broad-range antiviral nucleoside favipiravir reduces viral load in vivo by exerting antiviral mutagenesis in a mouse model for norovirus infection. Increased mutation frequencies were observed in samples from treated mice and were accompanied with lower or in some cases undetectable levels of infectious virus in faeces and tissues. Viral RNA isolated from treated animals showed reduced infectivity, a feature of populations approaching extinction during antiviral mutagenesis. These results suggest that favipiravir can induce norovirus mutagenesis in vivo, which in some cases leads to virus extinction, providing a proof-of-principle for the use of favipiravir derivatives or mutagenic nucleosides in the clinical treatment of noroviruses.

  9. In vivo acoustic and photoacoustic focusing of circulating cells

    NASA Astrophysics Data System (ADS)

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-03-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models.

  10. Photoacoustic molecular imaging for in vivo liver iron quantitation

    NASA Astrophysics Data System (ADS)

    Maccarinelli, Federica; Carmona, Fernando; Regoni, Maria; Arosio, Paolo

    2016-05-01

    A recent study showed that ferritin is a suitable endogenous contrast agent for photoacoustic molecular imaging in cultured mammalian cells. We have therefore tested whether this imaging technique can be used for in vivo quantification of iron in mouse livers. To verify this hypothesis, we used multispectral optoacoustic tomography (MSOT) to image albino CD1 mice before and after experimental iron loading. Postmortem assays showed that the iron treatment caused a 15-fold increase in liver iron and a 40-fold increase in liver ferritin levels, while in vivo longitudinal analysis using MSOT revealed just a 1.6-fold increase in the ferritin/iron photoacoustic signal in the same animals. We conclude that MSOT can monitor changes in ferritin/iron levels in vivo, but its sensitivity is much lower than that of ex vivo iron assays.

  11. Delivery of Therapeutic RNAs Into Target Cells IN VIVO

    NASA Astrophysics Data System (ADS)

    Ng, Mei Ying; Hagen, Thilo

    2014-02-01

    RNA-based therapy is one of the most promising approaches to treat human diseases. Specifically, the use of short interfering RNA (siRNA) siRNA and microRNA (miRNA) mimics for in vivo RNA interference has immense potential as it directly lowers the expression of the therapeutic target protein. However, there are a number of major roadblocks to the successful implementation of siRNA and other RNA based therapies in the clinic. These include the instability of RNAs in vivo and the difficulty to efficiently deliver the RNA into the target cells. Hence, various innovative approaches have been taken over the years to develop effective RNA delivery methods. These methods include liposome-, polymeric nanoparticle- and peptide-mediated cellular delivery. In a recent innovative study, bioengineered bacterial outer membrane vesicles were used as vehicles for effective delivery of siRNA into cells in vivo.

  12. Quantitating intracellular oxygen tension in vivo by phosphorescence lifetime measurement.

    PubMed

    Hirakawa, Yosuke; Yoshihara, Toshitada; Kamiya, Mako; Mimura, Imari; Fujikura, Daichi; Masuda, Tsuyoshi; Kikuchi, Ryohei; Takahashi, Ippei; Urano, Yasuteru; Tobita, Seiji; Nangaku, Masaomi

    2015-01-01

    Hypoxia appears to have an important role in pathological conditions in many organs such as kidney; however, a method to quantify intracellular oxygen tension in vivo has not been well established. In this study, we established an optical method to quantify oxygen tension in mice kidneys using a cationic lipophilic phosphorescence probe, BTPDM1, which has an intracellular oxygen concentration-sensitive phosphorescence lifetime. Since this probe is distributed inside the tubular cells of the mice kidney, we succeeded in detecting acute renal hypoxic conditions and chronic kidney disease. This technique enabled us to estimate intracellular partial pressures of oxygen in vivo by extrapolating the calibration curve generated from cultured tubular cells. Since intracellular oxygen tension is directly related to cellular hypoxic reactions, such as the activation of hypoxia-inducible factors, our method will shed new light on hypoxia research in vivo. PMID:26644023

  13. Visually Relating Gene Expression and in vivo DNA Binding Data

    SciTech Connect

    Huang, Min-Yu; Mackey, Lester; Ker?,; nen, Soile V. E.; Weber, Gunther H.; Jordan, Michael I.; Knowles, David W.; Biggin, Mark D.; Hamann, Bernd

    2011-09-20

    Gene expression and in vivo DNA binding data provide important information for understanding gene regulatory networks: in vivo DNA binding data indicate genomic regions where transcription factors are bound, and expression data show the output resulting from this binding. Thus, there must be functional relationships between these two types of data. While visualization and data analysis tools exist for each data type alone, there is a lack of tools that can easily explore the relationship between them. We propose an approach that uses the average expression driven by multiple of ciscontrol regions to visually relate gene expression and in vivo DNA binding data. We demonstrate the utility of this tool with examples from the network controlling early Drosophila development. The results obtained support the idea that the level of occupancy of a transcription factor on DNA strongly determines the degree to which the factor regulates a target gene, and in some cases also controls whether the regulation is positive or negative.

  14. Surface Corrosion of Nanoscaled Hydroxyapatite During an In Vivo Experiment.

    PubMed

    Seo, Dong Seok; Lee, Jong Kook; Hwang, Kyu Hong

    2015-10-01

    Hydroxyapatite (HA) is widely used as a bioactive ceramics as it forms a chemical bond with bone. However, the drawback to using this material is its inferior mechanical properties. In this research, surface corrosion and disintegration of nanoscaled HA in a dog were studied, and the mechanism by which phase-pure HA dissolved in vivo was investigated. Biological properties of HA in vivo are affected by the grain-boundary dissolution followed by a surface corrosion and microstructural disintegration. This kind of dissolution process, apparently evidenced at the grain boundary, causes particle generation, which indicates that both long-term bone in-growth and mechanical properties can dramatically deteriorate. Implant dissolution by osteoclasts in vivo is also observed on the surface of hydroxyapatite. Implant surface showed an aggressive corrosion by an osteoclast resorption. Severe and deeper dissolution underwent close to osteoclast resulting in formation of smaller and more round particle shape.

  15. Cerenkov Luminescence Tomography for In Vivo Radiopharmaceutical Imaging

    PubMed Central

    Zhong, Jianghong; Qin, Chenghu; Yang, Xin; Zhu, Shuping; Zhang, Xing; Tian, Jie

    2011-01-01

    Cerenkov luminescence imaging (CLI) is a cost-effective molecular imaging tool for biomedical applications of radiotracers. The introduction of Cerenkov luminescence tomography (CLT) relative to planar CLI can be compared to the development of X-ray CT based on radiography. With CLT, quantitative and localized analysis of a radiopharmaceutical distribution becomes feasible. In this contribution, a feasibility study of in vivo radiopharmaceutical imaging in heterogeneous medium is presented. Coupled with a multimodal in vivo imaging system, this CLT reconstruction method allows precise anatomical registration of the positron probe in heterogeneous tissues and facilitates the more widespread application of radiotracers. Source distribution inside the small animal is obtained from CLT reconstruction. The experimental results demonstrated that CLT can be employed as an available in vivo tomographic imaging of charged particle emitters in a heterogeneous medium. PMID:21747821

  16. Bioorthogonal Oxime Ligation Mediated In Vivo Cancer Targeting

    PubMed Central

    Tang, Li; Yin, Qian; Xu, Yunxiang; Zhou, Qin; Cai, Kaimin; Yen, Jonathan; Dobrucki, Lawrence W.

    2015-01-01

    Current cancer targeting relying on specific biological interaction between cell surface antigen and respective antibody or its analogue has proven to be effective in the treatment of different cancers; however, this strategy has its own limitations, such as heterogeneity of cancer cells and immunogenicity of the biomacromolecule binding ligands. Bioorthogonal chemical conjugation has emerged as an attractive alternative to biological interaction for in vivo cancer targeting. Here, we report an in vivo cancer targeting strategy mediated by bioorthogonal oxime ligation. Oxyamine group, the artificial target, is introduced onto 4T1 murine breast cancer cells through liposome delivery and fusion. Poly(ethylene glycol) -polylactide (PEG-PLA) nanoparticle (NP) is surface-functionalized with aldehyde groups as targeting ligands. The improved in vivo cancer targeting of PEG-PLA NPs is achieved through specific and efficient chemical reaction between the oxyamine and aldehyde groups. PMID:26146536

  17. In vivo modulation of endothelial polarization by Apelin receptor signalling

    PubMed Central

    Kwon, Hyouk-Bum; Wang, Shengpeng; Helker, Christian S. M.; Rasouli, S. Javad; Maischein, Hans-Martin; Offermanns, Stefan; Herzog, Wiebke; Stainier, Didier Y. R.

    2016-01-01

    Endothelial cells (ECs) respond to shear stress by aligning in the direction of flow. However, how ECs respond to flow in complex in vivo environments is less clear. Here we describe an endothelial-specific transgenic zebrafish line, whereby the Golgi apparatus is labelled to allow for in vivo analysis of endothelial polarization. We find that most ECs polarize within 4.5 h after the onset of vigorous blood flow and, by manipulating cardiac function, observe that flow-induced EC polarization is a dynamic and reversible process. Based on its role in EC migration, we analyse the role of Apelin signalling in EC polarization and find that it is critical for this process. Knocking down Apelin receptor function in human primary ECs also affects their polarization. Our study provides new tools to analyse the mechanisms of EC polarization in vivo and reveals an important role in this process for a signalling pathway implicated in cardiovascular disease. PMID:27248505

  18. Progress Toward In Vivo Use of siRNAs-II

    PubMed Central

    Rettig, Garrett R; Behlke, Mark A

    2012-01-01

    RNA interference (RNAi) has been extensively employed for in vivo research since its use was first demonstrated in mammalian cells 10 years ago. Design rules have improved, and it is now routinely possible to obtain reagents that suppress expression of any gene desired. At the same time, increased understanding of the molecular basis of unwanted side effects has led to the development of chemical modification strategies that mitigate these concerns. Delivery remains the single greatest hurdle to widespread adoption of in vivo RNAi methods. However, exciting advances have been made and new delivery systems under development may help to overcome these barriers. This review discusses advances in RNAi biochemistry and biology that impact in vivo use and provides an overview of select publications that demonstrate interesting applications of these principles. Emphasis is placed on work with synthetic, small interfering RNAs (siRNAs) published since the first installment of this review which appeared in 2006. PMID:22186795

  19. RNA circularization strategies in vivo and in vitro

    PubMed Central

    Petkovic, Sonja; Müller, Sabine

    2015-01-01

    In the plenitude of naturally occurring RNAs, circular RNAs (circRNAs) and their biological role were underestimated for years. However, circRNAs are ubiquitous in all domains of life, including eukaryotes, archaea, bacteria and viruses, where they can fulfill diverse biological functions. Some of those functions, as for example playing a role in the life cycle of viral and viroid genomes or in the maturation of tRNA genes, have been elucidated; other putative functions still remain elusive. Due to the resistance to exonucleases, circRNAs are promising tools for in vivo application as aptamers, trans-cleaving ribozymes or siRNAs. How are circRNAs generated in vivo and what approaches do exist to produce ring-shaped RNAs in vitro? In this review we illustrate the occurrence and mechanisms of RNA circularization in vivo, survey methods for the generation of circRNA in vitro and provide appropriate protocols. PMID:25662225

  20. Tracking immune cells in vivo using magnetic resonance imaging.

    PubMed

    Ahrens, Eric T; Bulte, Jeff W M

    2013-10-01

    The increasing complexity of in vivo imaging technologies, coupled with the development of cell therapies, has fuelled a revolution in immune cell tracking in vivo. Powerful magnetic resonance imaging (MRI) methods are now being developed that use iron oxide- and ¹⁹F-based probes. These MRI technologies can be used for image-guided immune cell delivery and for the visualization of immune cell homing and engraftment, inflammation, cell physiology and gene expression. MRI-based cell tracking is now also being applied to evaluate therapeutics that modulate endogenous immune cell recruitment and to monitor emerging cellular immunotherapies. These recent uses show that MRI has the potential to be developed in many applications to follow the fate of immune cells in vivo.

  1. In Vivo Generation of Neural Stem Cells Through Teratoma Formation.

    PubMed

    Hong, Yean Ju; Kim, Jong Soo; Choi, Hyun Woo; Song, Hyuk; Park, Chankyu; Do, Jeong Tae

    2016-09-01

    Pluripotent stem cells have the potential to differentiate into all cell types of the body in vitro through embryoid body formation or in vivo through teratoma formation. In this study, we attempted to generate in vivo neural stem cells (NSCs) differentiated through teratoma formation using Olig2-GFP transgenic embryonic stem cells (ESCs). After 4 to 6 weeks of injection with Olig2-GFP transgenic ESCs, Olig2-GFP(+) NSCs were identified in teratomas formed in immunodeficient mice. Interestingly, 4-week-old teratomas contained higher percentage of Olig2-GFP(+) cells (∼11%) than 6-week-old teratomas (∼3%). These in vivo-derived NSCs expressed common NSC markers (Nestin and Sox2) and differentiated into terminal neuronal and glial lineages. These results suggest that pure NSC populations exhibiting properties similar to those of brain-derived NSCs can be established through teratoma formation. PMID:27439546

  2. In vivo demonstration of surgical task assistance using miniature robots.

    PubMed

    Hawks, Jeff A; Kunowski, Jacob; Platt, Stephen R

    2012-10-01

    Laparoscopy is beneficial to patients as measured by less painful recovery and an earlier return to functional health compared to conventional open surgery. However, laparoscopy requires the manipulation of long, slender tools from outside the patient's body. As a result, laparoscopy generally benefits only patients undergoing relatively simple procedures. An innovative approach to laparoscopy uses miniature in vivo robots that fit entirely inside the abdominal cavity. Our previous work demonstrated that a mobile, wireless robot platform can be successfully operated inside the abdominal cavity with different payloads (biopsy, camera, and physiological sensors). We hope that these robots are a step toward reducing the invasiveness of laparoscopy. The current study presents design details and results of laboratory and in vivo demonstrations of several new payload designs (clamping, cautery, and liquid delivery). Laboratory and in vivo cooperation demonstrations between multiple robots are also presented. PMID:22893373

  3. In vivo acoustic and photoacoustic focusing of circulating cells

    PubMed Central

    Galanzha, Ekaterina I.; Viegas, Mark G.; Malinsky, Taras I.; Melerzanov, Alexander V.; Juratli, Mazen A.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Zharov, Vladimir P.

    2016-01-01

    In vivo flow cytometry using vessels as natural tubes with native cell flows has revolutionized the study of rare circulating tumor cells in a complex blood background. However, the presence of many blood cells in the detection volume makes it difficult to count each cell in this volume. We introduce method for manipulation of circulating cells in vivo with the use of gradient acoustic forces induced by ultrasound and photoacoustic waves. In a murine model, we demonstrated cell trapping, redirecting and focusing in blood and lymph flow into a tight stream, noninvasive wall-free transportation of blood, and the potential for photoacoustic detection of sickle cells without labeling and of leukocytes targeted by functionalized nanoparticles. Integration of cell focusing with intravital imaging methods may provide a versatile biological tool for single-cell analysis in circulation, with a focus on in vivo needleless blood tests, and preclinical studies of human diseases in animal models. PMID:26979811

  4. In vitro and in vivo evaluation of linear polyethylenimine nanoparticles.

    PubMed

    Goyal, Ritu; Tripathi, S K; Tyagi, S; Sharma, A; Kumar, P; Ram, K Ravi; Chowdhuri, D K; Shukla, Y; Gupta, K C

    2011-02-01

    bPEI (polyethylenimine, 25 kDa, gold standard) is highly effective in transfection efficiency owing to its high buffering capacity, however, cytotoxicity limits its use in in vivo applications. We hypothesized that partial conversion of secondary amines in IPEI to tertiary amines, while preserving the overall number of amines, would result in improved buffering capacity, which may, in turn, improve transfection efficiency of the resulting nanoparticles with cell viability comparable to that of native IPEI. IPEI was crosslinked with BDE to obtain a series of IPEI nanoparticles (LPN-1 to LPN-8) which were obtained in approximately 80-85% yield. These particles were relatively non-toxic in vitro and in vivo. In vivo gene expression studies using LPN-5 in Balb/c mice through i.v. injection showed maximum expression of the reporter gene in the spleen. These results demonstrate the potential of these particles as efficient transfection reagents. PMID:21485799

  5. Transgenic Mouse Models Enabling Photolabeling of Individual Neurons In Vivo

    PubMed Central

    Peter, Manuel; Bathellier, Brice; Fontinha, Bruno; Pliota, Pinelopi; Haubensak, Wulf; Rumpel, Simon

    2013-01-01

    One of the biggest tasks in neuroscience is to explain activity patterns of individual neurons during behavior by their cellular characteristics and their connectivity within the neuronal network. To greatly facilitate linking in vivo experiments with a more detailed molecular or physiological analysis in vitro, we have generated and characterized genetically modified mice expressing photoactivatable GFP (PA-GFP) that allow conditional photolabeling of individual neurons. Repeated photolabeling at the soma reveals basic morphological features due to diffusion of activated PA-GFP into the dendrites. Neurons photolabeled in vivo can be re-identified in acute brain slices and targeted for electrophysiological recordings. We demonstrate the advantages of PA-GFP expressing mice by the correlation of in vivo firing rates of individual neurons with their expression levels of the immediate early gene c-fos. Generally, the mouse models described in this study enable the combination of various analytical approaches to characterize living cells, also beyond the neurosciences. PMID:23626779

  6. In vivo genomic footprint of a yeast centromere.

    PubMed Central

    Densmore, L; Payne, W E; Fitzgerald-Hayes, M

    1991-01-01

    We have used in vivo genomic footprinting to investigate the protein-DNA interactions within the conserved DNA elements (CDEI, CDEII, and CDEIII) in the centromere from chromosome III of the yeast Saccharomyces cerevisiae. The in vivo footprint pattern obtained from wild-type cells shows that some guanines within the centromere DNA are protected from methylation by dimethyl sulfate. These results are consistent with studies demonstrating that yeast cells contain sequence-specific centromere DNA-binding proteins. Our in vivo experiments on chromosomes with mutant centromeres show that some mutations which affect chromosome segregation also alter the footprint pattern caused by proteins bound to the centromere DNA. The results of this study provide the first fine-structure map of proteins bound to centromere DNA in living yeast cells and suggest a direct correlation between these protein-DNA interactions and centromere function. Images PMID:1986217

  7. In vivo demonstration of surgical task assistance using miniature robots.

    PubMed

    Hawks, Jeff A; Kunowski, Jacob; Platt, Stephen R

    2012-10-01

    Laparoscopy is beneficial to patients as measured by less painful recovery and an earlier return to functional health compared to conventional open surgery. However, laparoscopy requires the manipulation of long, slender tools from outside the patient's body. As a result, laparoscopy generally benefits only patients undergoing relatively simple procedures. An innovative approach to laparoscopy uses miniature in vivo robots that fit entirely inside the abdominal cavity. Our previous work demonstrated that a mobile, wireless robot platform can be successfully operated inside the abdominal cavity with different payloads (biopsy, camera, and physiological sensors). We hope that these robots are a step toward reducing the invasiveness of laparoscopy. The current study presents design details and results of laboratory and in vivo demonstrations of several new payload designs (clamping, cautery, and liquid delivery). Laboratory and in vivo cooperation demonstrations between multiple robots are also presented.

  8. Quantitating intracellular oxygen tension in vivo by phosphorescence lifetime measurement

    PubMed Central

    Hirakawa, Yosuke; Yoshihara, Toshitada; Kamiya, Mako; Mimura, Imari; Fujikura, Daichi; Masuda, Tsuyoshi; Kikuchi, Ryohei; Takahashi, Ippei; Urano, Yasuteru; Tobita, Seiji; Nangaku, Masaomi

    2015-01-01

    Hypoxia appears to have an important role in pathological conditions in many organs such as kidney; however, a method to quantify intracellular oxygen tension in vivo has not been well established. In this study, we established an optical method to quantify oxygen tension in mice kidneys using a cationic lipophilic phosphorescence probe, BTPDM1, which has an intracellular oxygen concentration-sensitive phosphorescence lifetime. Since this probe is distributed inside the tubular cells of the mice kidney, we succeeded in detecting acute renal hypoxic conditions and chronic kidney disease. This technique enabled us to estimate intracellular partial pressures of oxygen in vivo by extrapolating the calibration curve generated from cultured tubular cells. Since intracellular oxygen tension is directly related to cellular hypoxic reactions, such as the activation of hypoxia-inducible factors, our method will shed new light on hypoxia research in vivo. PMID:26644023

  9. Single-site colectomy with miniature in vivo robotic platform.

    PubMed

    Wortman, Tyler D; Mondry, Jack M; Farritor, Shane M; Oleynikov, Dmitry

    2013-04-01

    There has been a continuing push to reduce the invasiveness of surgery by accessing the abdominal cavity through a single incision, such as with laparoendoscopic single-site (LESS) surgery. Although LESS procedures offer significant benefits, added complexities still inhibit the procedures. Robotic surgery is proving to be an excellent option to overcome these limitations. This paper presents the experimental results of the single-incision in vivo surgical robot (SISR), a multifunctional, dexterous, two-armed robot capable of performing surgical tasks while overcoming the issues associated with manual LESS operations. In vivo surgical procedures have been used to demonstrate the efficacy of using a robotic platform over traditional laparoscopic tools. The most recent experimental test resulted in the first successful in vivo robotic LESS colectomy utilizing a robot completely contained within the abdominal cavity. In this test, SISR showed significant benefits including access to all quadrants in the peritoneal cavity and improved dexterity.

  10. In vivo modeling of biofilm-infected wounds: a review.

    PubMed

    Seth, Akhil K; Geringer, Matthew R; Hong, Seok J; Leung, Kai P; Mustoe, Thomas A; Galiano, Robert D

    2012-11-01

    Chronic wounds continue to represent a difficult and complex problem for both patients and healthcare providers. Bacterial biofilms represent a critical component of nonhealing wounds, utilizing several different mechanisms to inhibit innate inflammatory pathways and resist traditional therapeutics. Although in vitro biofilm systems have been well described and studied, understanding the intricacies of wound biofilm pathology requires appropriate in vivo models to understand the interactions between bacteria and host. In an effort to clarify the available literature, this review describes and critically evaluates all of the in vivo wound biofilm models currently published to-date, including model advantages and clinical applicability. We will also address the need for continued therapeutic development and testing using these currently available in vivo models.

  11. In Vivo Reprogramming for Brain and Spinal Cord Repair.

    PubMed

    Chen, Gong; Wernig, Marius; Berninger, Benedikt; Nakafuku, Masato; Parmar, Malin; Zhang, Chun-Li

    2015-01-01

    Cell reprogramming technologies have enabled the generation of various specific cell types including neurons from readily accessible patient cells, such as skin fibroblasts, providing an intriguing novel cell source for autologous cell transplantation. However, cell transplantation faces several difficult hurdles such as cell production and purification, long-term survival, and functional integration after transplantation. Recently, in vivo reprogramming, which makes use of endogenous cells for regeneration purpose, emerged as a new approach to circumvent cell transplantation. There has been evidence for in vivo reprogramming in the mouse pancreas, heart, and brain and spinal cord with various degrees of success. This mini review summarizes the latest developments presented in the first symposium on in vivo reprogramming glial cells into functional neurons in the brain and spinal cord, held at the 2014 annual meeting of the Society for Neuroscience in Washington, DC. PMID:26730402

  12. Quantitating intracellular oxygen tension in vivo by phosphorescence lifetime measurement.

    PubMed

    Hirakawa, Yosuke; Yoshihara, Toshitada; Kamiya, Mako; Mimura, Imari; Fujikura, Daichi; Masuda, Tsuyoshi; Kikuchi, Ryohei; Takahashi, Ippei; Urano, Yasuteru; Tobita, Seiji; Nangaku, Masaomi

    2015-12-08

    Hypoxia appears to have an important role in pathological conditions in many organs such as kidney; however, a method to quantify intracellular oxygen tension in vivo has not been well established. In this study, we established an optical method to quantify oxygen tension in mice kidneys using a cationic lipophilic phosphorescence probe, BTPDM1, which has an intracellular oxygen concentration-sensitive phosphorescence lifetime. Since this probe is distributed inside the tubular cells of the mice kidney, we succeeded in detecting acute renal hypoxic conditions and chronic kidney disease. This technique enabled us to estimate intracellular partial pressures of oxygen in vivo by extrapolating the calibration curve generated from cultured tubular cells. Since intracellular oxygen tension is directly related to cellular hypoxic reactions, such as the activation of hypoxia-inducible factors, our method will shed new light on hypoxia research in vivo.

  13. Manufacture of die casting dies by hot isostatic pressing. CRADA final report

    SciTech Connect

    Viswanathan, S.; Ren, W.; Luk, K.; Brucher, H.G.

    1998-09-01

    The reason for this Cooperative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory (ORNL) and Doehler-Jarvis was to investigate the manufacture die-casting dies with internal water-cooling lines by hot-isostatic pressing (HIPing) of H13 tool steel powder. The use of HIPing will allow the near-net-shape manufacture of dies and the strategic placement of water-cooling lines during manufacture. The production of near-net-shape dies by HIPing involves the generation of HIPing diagrams, the design of the can that can be used for HIPing a die with complex details, strategic placement of water-cooling lines in the die, computer modeling to predict movement of the water lines during HIPing, and the development of strategies for placing water lines in the appropriate locations. The results presented include a literature review, particle analysis and characterization of H13 tool steel powder, and modeling of the HIPing process.

  14. Functional significance of glutamate-cysteine ligase modifier for erythrocyte survival in vitro and in vivo.

    PubMed

    Föller, M; Harris, I S; Elia, A; John, R; Lang, F; Kavanagh, T J; Mak, T W

    2013-10-01

    Erythrocytes endure constant exposure to oxidative stress. The major oxidative stress scavenger in erythrocytes is glutathione. The rate-limiting enzyme for glutathione synthesis is glutamate-cysteine ligase, which consists of a catalytic subunit (GCLC) and a modifier subunit (GCLM). Here, we examined erythrocyte survival in GCLM-deficient (gclm(-/-)) mice. Erythrocytes from gclm(-/-) mice showed greatly reduced intracellular glutathione. Prolonged incubation resulted in complete lysis of gclm(-/-) erythrocytes, which could be reversed by exogenous delivery of the antioxidant Trolox. To test the importance of GCLM in vivo, mice were treated with phenylhydrazine (PHZ; 0.07 mg/g b.w.) to induce oxidative stress. Gclm(-/-) mice showed dramatically increased hemolysis compared with gclm(+/+) controls. In addition, PHZ-treated gclm(-/-) mice displayed markedly larger accumulations of injured erythrocytes in the spleen than gclm(+/+) mice within 24 h of treatment. Iron staining indicated precipitations of the erythrocyte-derived pigment hemosiderin in kidney tubules of gclm(-/-) mice and none in gclm(+/+) controls. In fact, 24 h after treatment, kidney function began to diminish in gclm(-/-) mice as evident from increased serum creatinine and urea. Consequently, while all PHZ-treated gclm(+/+) mice survived, 90% of PHZ-treated gclm(-/-) mice died within 5 days of treatment. In vitro, upon incubation in the absence or presence of additional oxidative stress, gclm(-/-) erythrocytes exposed significantly more phosphatidylserine, a cell death marker, than gclm(+/+) erythrocytes, an effect at least partially due to increased cytosolic Ca(2+) concentration. Under resting conditions, gclm(-/-) mice exhibited reticulocytosis, indicating that the enhanced erythrocyte death was offset by accelerated erythrocyte generation. GCLM is thus indispensable for erythrocyte survival, in vitro and in vivo, during oxidative stress.

  15. Tracking of Multimodal Therapeutic Nanocomplexes Targeting Breast Cancer in Vivo

    PubMed Central

    Bardhan, Rizia; Chen, Wenxue; Bartels, Marc; Perez-Torres, Carlos; Botero, Maria F.; McAninch, Robin Ward; Contreras, Alejandro; Schiff, Rachel; Pautler, Robia G.; Halas, Naomi J.; Joshi, Amit

    2014-01-01

    Nanoparticle-based therapeutics with local delivery and external electromagnetic field modulation holds extraordinary promise for soft-tissue cancers such as breast cancer; however, knowledge of the distribution and fate of nanoparticles in vivo is crucial for clinical translation. Here we demonstrate that multiple diagnostic capabilities can be introduced in photothermal therapeutic nanocomplexes by simultaneously enhancing both near-infrared fluorescence and magnetic resonance imaging (MRI). We track nanocomplexes in vivo, examining the influence of HER2 antibody targeting on nanocomplex distribution over 72 h. This approach provides valuable, detailed information regarding the distribution and fate of complex nanoparticles designed for specific diagnostic and therapeutic functions. PMID:21090693

  16. In vivo melanoma depth detection by a handheld photoacoustic microscope

    NASA Astrophysics Data System (ADS)

    Zhou, Yong; Xing, Wenxin; Maslov, Konstantin I.; Cornelius, Lynn A.; Wang, Lihong V.

    2015-03-01

    We developed a handheld photoacoustic microscope (PAM) to detect melanoma and determine tumor depth in nude mice in vivo. Compared to our previous PAM system for melanoma imaging, a new light delivery mechanism is introduced to improve light penetration. We show that melanomas with 4.1 mm and 3.3 mm thicknesses can be successfully detected in phantom and in vivo experiments, respectively. With its deep melanoma imaging ability and novel handheld design, this system is promising for clinical melanoma diagnosis, prognosis, and surgical planning for patients at the bedside.

  17. In vivo Carbon-13 Nuclear Magnetic Resonance Studies of Mammals

    NASA Astrophysics Data System (ADS)

    Alger, J. R.; Sillerud, L. O.; Behar, K. L.; Gillies, R. J.; Shulman, R. G.; Gordon, R. E.; Shaw, D.; Hanley, P. E.

    1981-11-01

    Natural abundance carbon-13 nuclear magnetic resonances (NMR) from human arm and rat tissues have been observed in vivo. These signals arise primarily from triglycerides in fatty tissue. Carbon-13 NMR was also used to follow, in a living rat, the conversion of C-1--labeled glucose, which was introduced into the stomach, to C-1--labeled liver glycogen. The carbon-13 sensitivity and resolution obtained shows that natural abundance carbon-13 NMR will be valuable in the study of disorders in fat metabolism, and that experiments with substrates labeled with carbon-13 can be used to study carbohydrate metabolism in vivo.

  18. Translating cell biology in vitro to immunity in vivo

    NASA Astrophysics Data System (ADS)

    Boes, Marianne; Ploegh, Hidde L.

    2004-07-01

    The elimination of pathogens and pathogen-infected cells initially rests on the rapid deployment of innate immune defences. Should these defences fail, it is the lymphocytes - T cells and B cells - with their antigen-specific receptors that must rise to the task of providing adaptive immunity. Technological advances are now allowing immunologists to correlate data obtained in vitro with in vivo functions. A better understanding of T-cell activation in vivo could lead to more effective strategies for the treatment and prevention of infectious and autoimmmune diseases.

  19. Manipulating the in vivo immune response by targeted gene knockdown

    PubMed Central

    Lieberman, Judy

    2015-01-01

    Aptamers, nucleic acids selected for high affinity binding to proteins, can be used to activate or antagonize immune mediators or receptors in a location and cell-type specific manner and to enhance antigen presentation. They can also be linked to other molecules (other aptamers, siRNAs or miRNAs, proteins, toxins) to produce multifunctional compounds for targeted immune modulation in vivo. Aptamer-siRNA chimeras (AsiCs) that induce efficient cell-specific knockdown in immune cells in vitro and in vivo can be used as an immunological research tool or potentially as an immunomodulating therapeutic. PMID:26149459

  20. Molecular probes for the in vivo imaging of cancer

    PubMed Central

    Alford, Raphael; Ogawa, Mikako; Choyke, Peter L.

    2012-01-01

    Advancements in medical imaging have brought about unprecedented changes in the in vivo assessment of cancer. Positron emission tomography, single photon emission computed tomography, optical imaging, and magnetic resonance imaging are the primary tools being developed for oncologic imaging. These techniques may still be in their infancy, as recently developed chemical molecular probes for each modality have improved in vivo characterization of physiologic and molecular characteristics. Herein, we discuss advances in these imaging techniques, and focus on the major design strategies with which molecular probes are being developed. PMID:19823742

  1. In Vivo Gene Delivery by Nonviral Vectors: Overcoming Hurdles?

    PubMed Central

    Zhang, Yuan; Satterlee, Andrew; Huang, Leaf

    2012-01-01

    The promise of cancer gene therapeutics is hampered by difficulties in the in vivo delivery to the targeted tumor cells, and systemic delivery remains to be the biggest challenge to be overcome. Here, we concentrate on systemic in vivo gene delivery for cancer therapy using nonviral vectors. In this review, we summarize the existing delivery barriers together with the requirements and strategies to overcome these problems. We will also introduce the current progress in the design of nonviral vectors, and briefly discuss their safety issues. PMID:22525514

  2. Application of in vivo laser scanning microscope in dermatology

    NASA Astrophysics Data System (ADS)

    Lademann, Juergen; Richter, H.; Otberg, N.; Lawrenz, F.; Blume-Peytavi, U.; Sterry, W.

    2003-10-01

    The state of the art of in-vivo and in-vitro penetration measurements of topically applied substances is described. Only optical techniques represent online measuring methods based on the absorption or scattering properties of the topically applied substances. Laser scanning microscopy (LSM) has become a promising method for investigations in dermatology and skin physiology, after it was possible to analyze the skin surface on any body side in-vivo. In the present paper the application of a dermatological laser scanning microscope for penetration and distribution measurements of topically applied substances is described. The intercellular and follicular penetration pathways were studied.

  3. Biodegradable Xylitol-Based Elastomers: In Vivo Behavior and Biocompatibility

    PubMed Central

    Bruggeman, Joost P.; Bettinger, Christopher J.; Langer, Robert

    2010-01-01

    Biodegradable elastomers based on polycondensation reactions of xylitol with sebacic acid, referred to as poly(xylitol sebacate) (PXS) elastomers have recently been developed. Herein, we describe the in vivo behavior of PXS elastomers. Four PXS elastomers were synthesized, characterized and compared to poly(L-lactic-co-glycolic acid) (PLGA). PXS elastomers displayed a high level of structural integrity and form stability during degradation. The in vivo half-life ranged from approximately 3 to 52 weeks. PXS elastomers exhibited increased biocompatibility compared to PLGA implants. PMID:20540093

  4. Vaginal Lactobacillus: biofilm formation in vivo - clinical implications.

    PubMed

    Ventolini, Gary

    2015-01-01

    Vaginal lactobacilli provide protection against intrusive pathogenic bacteria. Some Lactobacillus spp. produce in vitro a thick, protective biofilm. We report in vivo formation of biofilm by vaginal Lactobacillus jensenii. The biofilm formation was captured in fresh wet-mount microscopic samples from asymptomatic patients after treatment for recurrent bacterial vaginitis. In vivo documentation of biofilm formation is in our opinion noteworthy, and has significant clinical implications, among which are the possibility to isolate, grow, and therapeutically utilize lactobacilli to prevent recurrent vaginal infections and preterm labor associated with vaginal microbial pathogens. PMID:25733930

  5. OCT-based in vivo tissue injury mapping

    NASA Astrophysics Data System (ADS)

    Baran, Utku; Li, Yuandong; Wang, Ruikang K.

    2016-03-01

    Tissue injury mapping (TIM) is developed by using a non-invasive in vivo optical coherence tomography to generate optical attenuation coefficient and microvascular map of the injured tissue. Using TIM, the infarct region development in mouse cerebral cortex during stroke is visualized. Moreover, we demonstrate the in vivo human facial skin structure and microvasculature during an acne lesion development. The results indicate that TIM may help in the study and the treatment of various diseases by providing high resolution images of tissue structural and microvascular changes.

  6. Modeling disease in vivo with CRISPR/Cas9

    PubMed Central

    Dow, Lukas E.

    2015-01-01

    The recent advent of CRISPR/Cas9-mediated genome editing has created a wave of excitement across the scientific research community, carrying the promise of simple and effective genomic manipulation of nearly any cell type. CRISPR has quickly become the preferred tool for genetic manipulation, and shows incredible promise as a platform for studying gene function in vivo. Here, I discuss the current application of CRISPR technology to create new in vivo disease models, with a particular focus on how these tools, derived from an adaptive bacterial immune system, are helping us better model the complexity of human cancer. PMID:26432018

  7. Celestial Fireworks from Dying Stars

    NASA Astrophysics Data System (ADS)

    2011-04-01

    This image of the nebula NGC 3582, which was captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile, shows giant loops of gas bearing a striking resemblance to solar prominences. These loops are thought to have been ejected by dying stars, but new stars are also being born within this stellar nursery. These energetic youngsters emit intense ultraviolet radiation that makes the gas in the nebula glow, producing the fiery display shown here. NGC 3582 is part of a large star-forming region in the Milky Way, called RCW 57. It lies close to the central plane of the Milky Way in the southern constellation of Carina (The Keel of Jason's ship, the Argo). John Herschel first saw this complex region of glowing gas and dark dust clouds in 1834, during his stay in South Africa. Some of the stars forming in regions like NGC 3582 are much heavier than the Sun. These monster stars emit energy at prodigious rates and have very short lives that end in explosions as supernovae. The material ejected from these dramatic events creates bubbles in the surrounding gas and dust. This is the probable cause of the loops visible in this picture. This image was taken through multiple filters. From the Wide Field Imager, data taken through a red filter are shown in green and red, and data taken through a filter that isolates the red glow characteristic of hydrogen are also shown in red. Additional infrared data from the Digitized Sky Survey are shown in blue. The image was processed by ESO using the observational data identified by Joe DePasquale, from the United States [1], who participated in ESO's Hidden Treasures 2010 astrophotography competition [2]. The competition was organised by ESO in October-November 2010, for everyone who enjoys making beautiful images of the night sky using astronomical data obtained using professional telescopes. Notes [1] Joe searched through ESO's archive and identified datasets that he used to compose his

  8. A comparison of the accuracy of three removable die systems and two die materials.

    PubMed

    Sivakumar, I; Mohan, J; Arunachalam, K S; Zankari, V

    2013-09-01

    The purpose of this study was to evaluate the dimensional shift of three commonly used die systems (Conventional system, Pindex system, Di-Lok tray system) with two commercially available type IV die stones (Ultra rock and Pearl stone). Under controlled conditions, ten casts, each with two removable dies, were constructed for each system for a total of 30 casts and 60 removable dies. Before and after sectioning measurements to within 0.01 mm in horizontal and vertical planes were recorded and differences calculated. Data were analyzed with 't' tests, one way analysis of variance and post hoc Tukey test. The results demonstrated that among the die systems compared, no single system was superior to the others in all respects. But among the die materials, dies poured in Pearl stone exhibited more dimensional changes than Ultra rock (p<0.05). Selection of die material is as critical as selection of any particular die system for successful fabrication of fixed partial denture and implant prosthesis.

  9. The morpholino molecular beacon for specific RNA visualization in vivo.

    PubMed

    Chen, Jianbin; Wu, Jikui; Hong, Yunhan

    2016-02-21

    A non-invasive fluorescent probe, morpholino molecular beacon (MO-MB), was designed for RNA visualization in vivo. Featuring negligible toxicity, stability, and high target specificity in living embryos, MO-MB is superior to conventional probes and has the potential for specific RNA visualization in basic biological and clinical research.

  10. Delineation of an in vivo inhibitor for Aspergillus glutamate dehydrogenase.

    PubMed

    Choudhury, Rajarshi; Noor, Shahid; Varadarajalu, Lakshmi Prabha; Punekar, Narayan S

    2008-01-01

    NADP-glutamate dehydrogenase (NADP-GDH) along with glutamine synthetase plays a pivotal role in ammonium assimilation. Specific inhibitors were valuable in defining the importance of glutamine synthetase in nitrogen metabolism. Selective in vivo inhibition of NADP-GDH has so far been an elusive desideratum. Isophthalate, a potent in vitro inhibitor of Aspergillus niger NADP-GDH [Noor S, Punekar NS. Allosteric NADP-glutamate dehydrogenase from aspergilli: purification, characterization and implications for metabolic regulation at the carbon-nitrogen interface. Microbiology 2005;151:1409-19], was evaluated for its efficacy in vivo. Dimethyl ester of isophthalate (DMIP), but not isophthalate, inhibited A. niger growth on agar as well as in liquid culture. This was ascribed to the inability of isophthalate to enter fungal mycelia. Subsequent to DMIP addition however, intracellular isophthalate could be demonstrated. Apart from NAD-GDH, no other enzyme including NAD-glutamate synthase was inhibited by isophthalate. A cross-over at NADP-GDH step of metabolism was observed as a direct consequence of isophthalate (formed in vivo from DMIP) inhibiting this enzyme. Addition of ammonium to DMIP-treated A. niger mycelia resulted in intensive vacuolation, retraction of cytoplasm and autolysis. Taken together, these results implicate glutamate dehydrogenase and NADP-GDH in particular, as a key target of in vivo isophthalate inhibition during ammonium assimilation. PMID:22578865

  11. Recent advances in microscopic techniques for visualizing leukocytes in vivo

    PubMed Central

    Jain, Rohit; Tikoo, Shweta; Weninger, Wolfgang

    2016-01-01

    Leukocytes are inherently motile and interactive cells. Recent advances in intravital microscopy approaches have enabled a new vista of their behavior within intact tissues in real time. This brief review summarizes the developments enabling the tracking of immune responses in vivo. PMID:27239292

  12. Monitoring tumor metastasis by in vivo imaging and flow cytometer

    NASA Astrophysics Data System (ADS)

    Gu, Zhenqin; Guo, Jin; Liu, Guangda; Li, Yan; Chen, Yun; Chen, Tong; Wang, Chen; Wei, Xunbin

    2009-08-01

    Prostate cancer is the most common malignancy in American men and the second leading cause of deaths from cancer, after lung cancer. The tumor usually grows slowly and remains confined to the gland for many years. During this time, the tumor produces little or no symptoms or outward signs. As the cancer advances, however, it can metastasize throughout other areas of the body, such as the bones, lungs, and liver. Surgical resection, hormonal therapy, chemotherapy and radiation therapy are the foundation of current prostate cancer therapies. Treatments for prostate cause both short- and long-term side effects that may be difficult to accept. Molecular mechanisms of prostate cancer metastasis need to be understood better and new therapies must be developed to selectively target to unique characteristics of cancer cell growth and metastasis. We have developed the "in vivo microscopy" to study the mechanisms that govern prostate cancer cell spread through the microenvironment in vivo in real-time confocal nearinfrared fluorescence imaging. A recently developed "in vivo flow cytometer" and optical imaging are used to assess prostate cancer cell spreading and the circulation kinetics of prostate cancer cells. A real- time quantitative monitoring of circulating prostate cancer cells by the in vivo flow cytometer will be useful to assess the effectiveness of the potential therapeutic interventions.

  13. Children's Coping with "In Vivo" Peer Rejection: An Experimental Investigation

    ERIC Educational Resources Information Center

    Reijntjes, Albert; Stegge, Hedy; Terwogt, Mark Meerum; Kamphuis, Jan Henk; Telch, Michael J.

    2006-01-01

    We examined children's behavioral coping in response to an "in vivo" peer rejection manipulation. Participants (N = 186) ranging between 10 and 13 years of age, played a computer game based on the television show "Survivor" and were randomized to either peer rejection (i.e., being voted out of the game) or non-rejection control. During a five-min.…

  14. On-chip immobilization of planarians for in vivo imaging.

    PubMed

    Dexter, Joseph P; Tamme, Mary B; Lind, Christine H; Collins, Eva-Maria S

    2014-09-17

    Planarians are an important model organism for regeneration and stem cell research. A complete understanding of stem cell and regeneration dynamics in these animals requires time-lapse imaging in vivo, which has been difficult to achieve due to a lack of tissue-specific markers and the strong negative phototaxis of planarians. We have developed the Planarian Immobilization Chip (PIC) for rapid, stable immobilization of planarians for in vivo imaging without injury or biochemical alteration. The chip is easy and inexpensive to fabricate, and worms can be mounted for and removed after imaging within minutes. We show that the PIC enables significantly higher-stability immobilization than can be achieved with standard techniques, allowing for imaging of planarians at sub-cellular resolution in vivo using brightfield and fluorescence microscopy. We validate the performance of the PIC by performing time-lapse imaging of planarian wound closure and sequential imaging over days of head regeneration. We further show that the device can be used to immobilize Hydra, another photophobic regenerative model organism. The simple fabrication, low cost, ease of use, and enhanced specimen stability of the PIC should enable its broad application to in vivo studies of stem cell and regeneration dynamics in planarians and Hydra.

  15. Strength in Numbers: Visualizing CTL-Mediated Killing In Vivo.

    PubMed

    Nolz, Jeffrey C; Hill, Ann B

    2016-02-16

    Cytotoxic CD8+ T lymphocytes (CTLs) have long been believed to be extremely efficient killers. Forster and colleagues (Halle et al., 2016) used in vivo imaging to tell a different story, in which each CTL killed only 2-16 targets a day, and several CTLs per target were needed to get the job done. PMID:26885849

  16. A Comparison of In Vitro and In Vivo Asexual Embryogenesis.

    PubMed

    Hand, Melanie L; de Vries, Sacco; Koltunow, Anna M G

    2016-01-01

    In plants, embryogenesis generally occurs through the sexual process of double fertilization, which involves a haploid sperm cell fusing with a haploid egg cell to ultimately give rise to a diploid embryo. Embryogenesis can also occur asexually in the absence of fertilization, both in vitro and in vivo. Somatic or gametic cells are able to differentiate into embryos in vitro following the application of plant growth regulators or stress treatments. Asexual embryogenesis also occurs naturally in some plant species in vivo, from either ovule cells as part of a process defined as apomixis, or from somatic leaf tissue in other species. In both in vitro and in vivo asexual embryogenesis, the embryo precursor cells must attain an embryogenic fate without the act of fertilization. This review compares the processes of in vitro and in vivo asexual embryogenesis including what is known regarding the genetic and epigenetic regulation of each process, and considers how the precursor cells are able to change fate and adopt an embryogenic pathway. PMID:26619856

  17. Educating and training India's next generation of in vivo pharmacologists.

    PubMed

    Lewis, David I

    2016-01-01

    The Indian Pharmaceutical Industry is undergoing rapid development and expansion. Critical to this process, and the future of drug discovery in India is the continued education and training of integrative or in vivo pharmacologists, equipped with the knowledge, skills and expertise to undertake studies using laboratory animals. Modern in vivo pharmacologists not only require manual or technical skills, but a much broader education including in animal welfare, ethics, the principles of the replacement, refinement and reduction of animals in research, and nonanimal alternative techniques. This education, training, and continued professional development throughout their careers can be provided, in part, through the use of online e-learning resources. While many excellent resources exist, they are hard to locate and not widely known to the community. To address this issue, Education and Training Resources in In vivo Sciences, a free website which provides access to free open access e-learning resources in in vivo pharmacology was developed. Use of this resource by researchers and educators will result in better-trained researchers and members of ethical review committees, which in turn will raise animal welfare standards, minimize the pain, suffering and distress of laboratory animals, and enhance scientific research. PMID:27298489

  18. In-vivo morphologic and spectroscopic investigation of Psoriasis

    NASA Astrophysics Data System (ADS)

    Kapsokalyvas, Dimitrios; Cicchi, Riccardo; Bruscino, Nicola; Alfieri, Domenico; Massi, Daniela; Lotti, Torello; Pavone, Francesco S.

    2011-07-01

    Psoriasis is an autoimmune disease of the skin characterized by hyperkeratosis, hyperproliferation of the epidermis, inflammatory cell accumulation and increased dilatation of dermal papillary blood vessels. Cases of psoriasis were investigated in vivo with optical means in order to evaluate the potential of in vivo optical biopsy. A Polarization Multispectral Dermoscope was employed for the macroscopic observation. Features such as the 'dotted' blood vessels pattern was observed with high contrast. High resolution image sections of the epidermis and the dermis were produced with a custom made Multiphoton Microscope. Imaging extended from the surface of the lesion down to the papillary dermis, at a depth of 200 μm. In the epidermis, a characteristic morphology of the stratum corneum found only in Psoriasis was revealed. Additionally, the cytoplasmic area of the cells in the stratum spinosum layer was found to be smaller than normal. In the dermis the morphological features were more pronounced, where the elongated dermal papillae dominated the papillary layer. Their length exceeds 100μm, which is a far greater value compared to that of healthy skin. These in vivo observations are consistent with the ex vivo histopathological observations, supporting both the applicability and potentiality of multispectral dermoscopy and multiphoton microscopy in the field of in vivo optical investigation and biopsy of skin.

  19. In vivo static field perturbations in magnetic resonance

    NASA Astrophysics Data System (ADS)

    Koch, Kevin Matthew

    2007-12-01

    Fundamental magnetic resonance (MR) theory assumes the spatial homogeneity of a dominating static magnetic field B = B 0ẑ. When this assumption is violated, a myriad of artifacts and compromising factors are introduced to MR spectra and images. Though in vivo nuclear magnetic resonance (NMR) is one of the most widely used scientific and diagnostic tools in medicine and biology, it remains haunted by the continual and persistant ghost of B0 inhomogeneity. An inclusive list of in vivo NMR applications severely impacted by B0 inhomogeneity could go on ad infinitum. Examples of such applications include neurosurgical utility in functional magnetic resonance imaging (fMRI), cerebral metabolic flux mapping, cerebral diffusion tractography, and abdominal diagnostic imaging. Given this wide impact on in vivo NMR, significant effort has been exerted in developing methods of compensating B0 inhomogeneity. Complicating this task is the sample-specific nature of in vivo B 0 inhomogeneity and its exacerbation with ever increasing B 0 field strengths. State of the art B 0 inhomogeneity compensation is currently at a critical juncture where homogenization demands are overwhelming the outer capabilities of existing technology and methods. This thesis addresses the B 0 inhomogeneity problem in the mammalian brain and presents novel solutions to the homogenization technology stalemate.

  20. Analysis of the mutations inducedd by conazole fungicides in vivo

    EPA Science Inventory

    The mouse liver tumorigenic conazo1e fungicides triadimefon and propiconazo1e have previously been shown to be in vivo mouse liver mutagens in the Big Blue" transgenic mutation assay when administered in feed at tumorigenic doses, whereas the nontumorigenic conazo1e myc1obutani1 ...

  1. Performance testing of radiobioassay laboratories: In vivo measurements, Final Report

    SciTech Connect

    MacLellan, J.A.; Traub, R.J.; Olsen, P.C.

    1990-04-01

    A study of two rounds of in vivo laboratory performance testing was undertaken by Pacific Northwest Laboratory (PNL) to determine the appropriateness of the in vivo performance criteria of draft American National Standards Institute (ANSI) standard ANSI N13.3, Performance Criteria for Bioassay.'' The draft standard provides guidance to in vivo counting facilities regarding the sensitivity, precision, and accuracy of measurements for certain categories of commonly assayed radionuclides and critical regions of the body. This report concludes the testing program by presenting the results of the Round Two testing. Testing involved two types of measurements: chest counting for radionuclide detection in the lung, and whole body counting for detection of uniformly distributed material. Each type of measurement was further divided into radionuclide categories as defined in the draft standard. The appropriateness of the draft standard criteria by measuring a laboratory's ability to attain them were judged by the results of both round One and Round Two testing. The testing determined that performance criteria are set at attainable levels, and the majority of in vivo monitoring facilities passed the criteria when complete results were submitted. 18 refs., 18 figs., 15 tabs.

  2. Does atorvastatin induce aortic smooth muscle cell apoptosis in vivo?

    PubMed

    Doyon, Marielle; Hale, Taben Mary; Huot-Marchand, Julie-Emilie; Wu, Rong; de Champlain, Jacques; DeBlois, Denis

    2011-01-01

    It has been reported that HMG-CoA reductase inhibitors such as atorvastatin induce vascular smooth muscle cell (SMC) apoptosis in vitro. However, this effect remains to be demonstrated in vivo. The present studies were designed to test the ability of atorvastatin to induce SMC apoptosis in vivo, using the spontaneously hypertensive rat (SHR) as a well-known reference model of SMC apoptosis induction in vivo by cardiovascular drugs including the calcium channel blocker amlodipine. Atorvastatin was administered to SHR for 3 or 6 weeks either alone or together with amlodipine, a drug combination clinically available to patients. Primary endpoints included aortic medial hypertrophy and aortic SMC hyperplasia, internucleosomal DNA fragmentation and expression of the apoptosis regulatory proteins Bax and Bcl-2. The SHR aorta showed no evidence of SMC apoptosis induction by atorvastatin, even at the high dose of 50 mg kg(-1) day(-1), although the statin significantly reduced oxidative stress after 3 weeks and blood pressure after 6 weeks of administration. Amlodipine-induced regression of aortic hypertophy and aortic SMC hyperplasia were dose- and time-dependent, but there was no interaction between atorvastatin and amlodipine in modulating the primary endpoints. These results do not support the notion that atorvastatin induces SMC apoptosis in the aortic media in vivo.

  3. IN VIVO DERMAL ABSORPTION OF PYRETHROID PESTICIDES IN THE RAT

    EPA Science Inventory

    The potential for exposure to pyrethroid pesticides has risen recently because of their increased agricultural and residential use. The objective of this study was to examine the in vivo dermal absorption of bifenthrin, deltamethrin and cis-permethrin in the rat. Hair on...

  4. In vivo dermal absorption of pyrethroid pesticides in the rat.

    EPA Science Inventory

    The potential for exposure to pyrethroid pesticides has risen recently because of their increased use. The objective of this study was to examine the in vivo dermal absorption of bifenthrin, deltamethrin and permethrin in the rat. Hair on the dorsal side of anesthetized adult m...

  5. Carbon Nanomaterials Interfacing with Neurons: An In vivo Perspective

    PubMed Central

    Baldrighi, Michele; Trusel, Massimo; Tonini, Raffaella; Giordani, Silvia

    2016-01-01

    Developing new tools that outperform current state of the art technologies for imaging, drug delivery or electrical sensing in neuronal tissues is one of the great challenges in neurosciences. Investigations into the potential use of carbon nanomaterials for such applications started about two decades ago. Since then, numerous in vitro studies have examined interactions between these nanomaterials and neurons, either by evaluating their compatibility, as vectors for drug delivery, or for their potential use in electric activity sensing and manipulation. The results obtained indicate that carbon nanomaterials may be suitable for medical therapies. However, a relatively small number of in vivo studies have been carried out to date. In order to facilitate the transformation of carbon nanomaterial into practical neurobiomedical applications, it is essential to identify and highlight in the existing literature the strengths and weakness that different carbon nanomaterials have displayed when probed in vivo. Unfortunately the current literature is sometimes sparse and confusing. To offer a clearer picture of the in vivo studies on carbon nanomaterials in the central nervous system, we provide a systematic and critical review. Hereby we identify properties and behavior of carbon nanomaterials in vivo inside the neural tissues, and we examine key achievements and potentially problematic toxicological issues. PMID:27375413

  6. In Vivo Axial Loading of the Mouse Tibia

    PubMed Central

    Melville, Katherine M.; Robling, Alexander G.

    2015-01-01

    Summary Non-invasive methods to apply controlled, cyclic loads to the living skeleton are used as an anabolic agent to stimulate new bone formation in adults and enhance bone mass accrual in growing animals. These methods are also invaluable for understanding bone signaling pathways. Our focus here is on a particular loading model: in vivo axial compression of the mouse tibia. An advantage of loading the tibia is that changes are present in both the cancellous envelope of the proximal tibia and the cortical bone of the tibial diaphysis. To load the tibia of the mouse axially in vivo, a cyclic compressive load is applied up to five times a week to a single tibia per mouse for a duration lasting from 1 day to 6 weeks. With the contralateral limb as an internal control, the anabolic response of the skeleton to mechanical stimuli can be studied in a pairwise experimental design. Here, we describe the key parameters that must be considered before beginning an in vivo mouse tibial loading experiment, including methods for in vivo strain gauging of the tibial midshaft, and then we describe general methods for loading the mouse tibia for an experiment lasting multiple days. PMID:25331046

  7. Coxsackievirus B3 mutator strains are attenuated in vivo.

    PubMed

    Gnädig, Nina F; Beaucourt, Stéphanie; Campagnola, Grace; Bordería, Antonio V; Sanz-Ramos, Marta; Gong, Peng; Blanc, Hervé; Peersen, Olve B; Vignuzzi, Marco

    2012-08-21

    Based on structural data of the RNA-dependent RNA polymerase, rational targeting of key residues, and screens for Coxsackievirus B3 fidelity variants, we isolated nine polymerase variants with mutator phenotypes, which allowed us to probe the effects of lowering fidelity on virus replication, mutability, and in vivo fitness. These mutator strains generate higher mutation frequencies than WT virus and are more sensitive to mutagenic treatments, and their purified polymerases present lower-fidelity profiles in an in vitro incorporation assay. Whereas these strains replicate with WT-like kinetics in tissue culture, in vivo infections reveal a strong correlation between mutation frequency and fitness. Variants with the highest mutation frequencies are less fit in vivo and fail to productively infect important target organs, such as the heart or pancreas. Furthermore, whereas WT virus is readily detectable in target organs 30 d after infection, some variants fail to successfully establish persistent infections. Our results show that, although mutator strains are sufficiently fit when grown in large population size, their fitness is greatly impacted when subjected to severe bottlenecking, which would occur during in vivo infection. The data indicate that, although RNA viruses have extreme mutation frequencies to maximize adaptability, nature has fine-tuned replication fidelity. Our work forges ground in showing that the mutability of RNA viruses does have an upper limit, where larger than natural genetic diversity is deleterious to virus survival.

  8. Detecting virulence and drug resistance mycobacterial phenotypes in vivo

    PubMed Central

    Timmins, Graham

    2015-01-01

    Bacterial phenotypes are predominantly studied in culture because detection of their specific metabolic pathways in the host is challenging. Development of stable isotope breath tests allowing in situ phenotype analyses may endow diagnostics with new modalities based upon direct monitoring of in vivo microbial metabolism and host–pathogen phenotypic interactions. PMID:25800730

  9. 40 CFR 79.64 - In vivo micronucleus assay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... information on this test guideline, the following references should be consulted. (1) 40 CFR 798.5395, In Vivo... that, because it contains RNA, can be differentiated by appropriate staining techniques from a normochromatic erythrocyte (NCE), which lacks RNA. In one to two days, a PCE matures into a NCE. (c) Test...

  10. 40 CFR 79.64 - In vivo micronucleus assay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... information on this test guideline, the following references should be consulted. (1) 40 CFR 798.5395, In Vivo... that, because it contains RNA, can be differentiated by appropriate staining techniques from a normochromatic erythrocyte (NCE), which lacks RNA. In one to two days, a PCE matures into a NCE. (c) Test...

  11. 40 CFR 79.64 - In vivo micronucleus assay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... information on this test guideline, the following references should be consulted. (1) 40 CFR 798.5395, In Vivo... that, because it contains RNA, can be differentiated by appropriate staining techniques from a normochromatic erythrocyte (NCE), which lacks RNA. In one to two days, a PCE matures into a NCE. (c) Test...

  12. In vivo continuous evolution of genes and pathways in yeast

    PubMed Central

    Crook, Nathan; Abatemarco, Joseph; Sun, Jie; Wagner, James M.; Schmitz, Alexander; Alper, Hal S.

    2016-01-01

    Directed evolution remains a powerful, highly generalizable approach for improving the performance of biological systems. However, implementations in eukaryotes rely either on in vitro diversity generation or limited mutational capacities. Here we synthetically optimize the retrotransposon Ty1 to enable in vivo generation of mutant libraries up to 1.6 × 107 l−1 per round, which is the highest of any in vivo mutational generation approach in yeast. We demonstrate this approach by using in vivo-generated libraries to evolve single enzymes, global transcriptional regulators and multi-gene pathways. When coupled to growth selection, this approach enables in vivo continuous evolution (ICE) of genes and pathways. Through a head-to-head comparison, we find that ICE libraries yield higher-performing variants faster than error-prone PCR-derived libraries. Finally, we demonstrate transferability of ICE to divergent yeasts, including Kluyveromyces lactis and alternative S. cerevisiae strains. Collectively, this work establishes a generic platform for rapid eukaryotic-directed evolution across an array of target cargo. PMID:27748457

  13. ANTIOXIDANTS AMELIORATION OF ARSENICAL-INDUCED EFFECTS IN VIVO

    EPA Science Inventory

    Antioxidant amelioration of arsenical-induced effects in vivo. ES Hunter and EH Rogers. Reproductive Toxicology Division, NHEERL, US EPA, RTP, NC.

    Antioxidants have been reported to ameliorate the effects of many developmental toxicants. We tested the hypothesis that oxi...

  14. Efficient in vivo Vascularization of Tissue Engineering Scaffolds

    PubMed Central

    Hegen, Anja; Blois, Anna; Tiron, Crina E.; Hellesøy, Monica; Micklem, David R.; Nör, Jacques E.; Akslen, Lars A.; Lorens, James B.

    2010-01-01

    The success of tissue engineering depends on the rapid and efficient formation of a functional blood vasculature. Adult blood vessels comprise endothelial cells and peri-vascular mural cells that assemble into patent tubules ensheathed by a basement membrane during angiogenesis. Using individual vessel components, we characterized intra-scaffold microvessel self-assembly efficiency in a physiological in vivo tissue engineering implant context. Primary human microvascular endothelial- and vascular smooth muscle cells were seeded at different ratios in poly-L lactic acid (PLLA) scaffolds enriched with basement membrane proteins (Matrigel) and implanted subcutaneously into immunocompromised mice. Temporal intra-scaffold microvessel formation, anastomosis and perfusion were monitored by immunohistochemical, flow cytometric and in vivo multiphoton fluorescence microscopy analysis. Vascularization in the tissue engineering context was strongly enhanced in the implants seeded with a complete complement of blood vessel components: Human microvascular endothelial and vascular smooth muscle cells in vivo assembled a patent microvasculature within Matrigel-enriched PLLA scaffolds that anastomosed with the host circulation during the first week of implantation. Multiphoton fluorescence angiographic analysis of the intra-scaffold microcirculation showed a uniform, branched microvascular network. 3-D image reconstruction analysis of hPASMC distribution within vascularized implants was non-random and displayed a preferential peri-vascular localization. Hence, efficient microvessel self-assembly, anastomosis and establishment of a functional microvasculture in the native hypoxic in vivo tissue engineering context is promoted by providing a complete set of vascular components. PMID:20865694

  15. Mitochondrial energetics is impaired in vivo in aged skeletal muscle.

    PubMed

    Gouspillou, Gilles; Bourdel-Marchasson, Isabelle; Rouland, Richard; Calmettes, Guillaume; Biran, Marc; Deschodt-Arsac, Véronique; Miraux, Sylvain; Thiaudiere, Eric; Pasdois, Philippe; Detaille, Dominique; Franconi, Jean-Michel; Babot, Marion; Trézéguet, Véronique; Arsac, Laurent; Diolez, Philippe

    2014-02-01

    With aging, most skeletal muscles undergo a progressive loss of mass and strength, a process termed sarcopenia. Aging-related defects in mitochondrial energetics have been proposed to be causally involved in sarcopenia. However, changes in muscle mitochondrial oxidative phosphorylation with aging remain a highly controversial issue, creating a pressing need for integrative approaches to determine whether mitochondrial bioenergetics are impaired in aged skeletal muscle. To address this issue, mitochondrial bioenergetics was first investigated in vivo in the gastrocnemius muscle of adult (6 months) and aged (21 months) male Wistar rats by combining a modular control analysis approach with (31) P magnetic resonance spectroscopy measurements of energetic metabolites. Using this innovative approach, we revealed that the in vivo responsiveness ('elasticity') of mitochondrial oxidative phosphorylation to contraction-induced increase in ATP demand is significantly reduced in aged skeletal muscle, a reduction especially pronounced under low contractile activities. In line with this in vivo aging-related defect in mitochondrial energetics, we found that the mitochondrial affinity for ADP is significantly decreased in mitochondria isolated from aged skeletal muscle. Collectively, the results of this study demonstrate that mitochondrial bioenergetics are effectively altered in vivo in aged skeletal muscle and provide a novel cellular basis for this phenomenon. PMID:23919652

  16. In vivo axial loading of the mouse tibia.

    PubMed

    Melville, Katherine M; Robling, Alexander G; van der Meulen, Marjolein C H

    2015-01-01

    Noninvasive methods to apply controlled, cyclic loads to the living skeleton are used as anabolic procedures to stimulate new bone formation in adults and enhance bone mass accrual in growing animals. These methods are also invaluable for understanding bone signaling pathways. Our focus here is on a particular loading model: in vivo axial compression of the mouse tibia. An advantage of loading the tibia is that changes are present in both the cancellous envelope of the proximal tibia and the cortical bone of the tibial diaphysis. To load the tibia of the mouse axially in vivo, a cyclic compressive load is applied up to five times a week to a single tibia per mouse for a duration lasting from 1 day to 6 weeks. With the contralateral limb as an internal control, the anabolic response of the skeleton to mechanical stimuli can be studied in a pairwise experimental design. Here, we describe the key parameters that must be considered before beginning an in vivo mouse tibial loading experiment, including methods for in vivo strain gauging of the tibial midshaft, and then we describe general methods for loading the mouse tibia for an experiment lasting multiple days. PMID:25331046

  17. A Comparison of In Vitro and In Vivo Asexual Embryogenesis.

    PubMed

    Hand, Melanie L; de Vries, Sacco; Koltunow, Anna M G

    2016-01-01

    In plants, embryogenesis generally occurs through the sexual process of double fertilization, which involves a haploid sperm cell fusing with a haploid egg cell to ultimately give rise to a diploid embryo. Embryogenesis can also occur asexually in the absence of fertilization, both in vitro and in vivo. Somatic or gametic cells are able to differentiate into embryos in vitro following the application of plant growth regulators or stress treatments. Asexual embryogenesis also occurs naturally in some plant species in vivo, from either ovule cells as part of a process defined as apomixis, or from somatic leaf tissue in other species. In both in vitro and in vivo asexual embryogenesis, the embryo precursor cells must attain an embryogenic fate without the act of fertilization. This review compares the processes of in vitro and in vivo asexual embryogenesis including what is known regarding the genetic and epigenetic regulation of each process, and considers how the precursor cells are able to change fate and adopt an embryogenic pathway.

  18. Quantifying in vivo MR spectra with circles ⋆

    PubMed Central

    Gabr, Refaat E.; Ouwerkerk, Ronald; Bottomley, Paul A.

    2007-01-01

    Accurate and robust quantification of in vivo magnetic resonance spectroscopy (MRS) data is essential to its application in research and medicine. The performance of existing analysis methods is problematic for in vivo studies where low signal-to-noise ratio, overlapping peaks and intense artefacts are endemic. Here, a new frequency-domain technique for MRS data analysis is introduced wherein the circular trajectories which result when spectral peaks are projected onto the complex plane, are fitted with active circle models. The use of active contour strategies naturally allows incorporation of prior knowledge as constraint energy terms. The problem of phasing spectra is eliminated, and baseline artefacts are dealt with using active contours-snakes. The stability and accuracy of the new technique, CFIT, is compared with a standard time-domain fitting tool, using simulated 31P data with varying amounts of noise and 98 real human chest and heart 31P MRS data sets. The real data were also analyzed by our standard frequency-domain absorption-mode technique. On the real data, CFIT demonstrated the least fitting failures of all methods and an accuracy similar to the latter method, with both these techniques outperforming the time-domain approach. Contrasting results from simulations argue that performance relative to Cramer-Rao Bounds may not be a suitable indicator of fitting performance with typical in vivo data such as these. We conclude that CFIT is a stable, accurate alternative to the best existing methods of fitting in vivo data. PMID:16325436

  19. Non-invasive in vivo measurement of macular carotenoids

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2009-01-01

    A non-invasive in vivo method for assessing macular carotenoids includes performing Optical Coherence Tomography (OCT) on a retina of a subject. A spatial representation of carotenoid levels in the macula based on data from the OCT of the retina can be generated.

  20. ASSESSING TCDD WASTING SYNDROME IN AN IN VIVO OBESITY MODEL

    EPA Science Inventory

    TCDD is a by-product of incineration commonly found as a microcontaminant in the food supply. The TCDD wasting syndrome, characterized by prolonged weight loss, has been examined for decades. Much of this work has focused on high dose in vivo and in vitro studies....

  1. The morpholino molecular beacon for specific RNA visualization in vivo.

    PubMed

    Chen, Jianbin; Wu, Jikui; Hong, Yunhan

    2016-02-21

    A non-invasive fluorescent probe, morpholino molecular beacon (MO-MB), was designed for RNA visualization in vivo. Featuring negligible toxicity, stability, and high target specificity in living embryos, MO-MB is superior to conventional probes and has the potential for specific RNA visualization in basic biological and clinical research. PMID:26810703

  2. Veni, vidi, vici: in vivo molecular imaging of immune response.

    PubMed

    Gross, Shimon; Moss, Britney L; Piwnica-Worms, David

    2007-10-01

    "I came, I saw, I conquered," Julius Caesar proclaimed, highlighting the importance of direct visualization as a winning strategy. Continuing the "From the Field" series (see Editorial [2007] 26, 131), Gross et al. summarize how modern molecular imaging techniques can successfully dissect the complexities of immune response in vivo. PMID:17967405

  3. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0μm, field of view 200μm x 100μm (lateral resolution , 0.3μm). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In

  4. Methods of in-vivo mouse lung micro-CT

    NASA Astrophysics Data System (ADS)

    Recheis, Wolfgang A.; Nixon, Earl; Thiesse, Jacqueline; McLennan, Geoffrey; Ross, Alan; Hoffman, Eric

    2005-04-01

    Micro-CT will have a profound influence on the accumulation of anatomical and physiological phenotypic changes in natural and transgenetic mouse models. Longitudinal studies will be greatly facilitated, allowing for a more complete and accurate description of events if in-vivo studies are accomplished. The purpose of the ongoing project is to establish a feasible and reproducible setup for in-vivo mouse lung micro-computed tomography (μCT). We seek to use in-vivo respiratory-gated μCT to follow mouse models of lung disease with subsequent recovery of the mouse. Methodologies for optimizing scanning parameters and gating for the in-vivo mouse lung are presented. A Scireq flexiVent ventilated the gas-anesthetized mice at 60 breaths/minute, 30 cm H20 PEEP, 30 ml/kg tidal volume and provided a respiratory signal to gate a Skyscan 1076 μCT. Physiologic monitoring allowed the control of vital functions and quality of anesthesia, e.g. via ECG monitoring. In contrary to longer exposure times with ex-vivo scans, scan times for in-vivo were reduced using 35μm pixel size, 158ms exposure time and 18μm pixel size, 316ms exposure time to reduce motion artifacts. Gating via spontaneous breathing was also tested. Optimal contrast resolution was achieved at 50kVp, 200μA, applying an aluminum filter (0.5mm). There were minimal non-cardiac related motion artifacts. Both 35μm and 1μm voxel size images were suitable for evaluation of the airway lumen and parenchymal density. Total scan times were 30 and 65 minutes respectively. The mice recovered following scanning protocols. In-vivo lung scanning with recovery of the mouse delivered reasonable image quality for longitudinal studies, e.g. mouse asthma models. After examining 10 mice, we conclude μCT is a feasible tool evaluating mouse models of lung pathology in longitudinal studies with increasing anatomic detail available for evaluation as one moves from in-vivo to ex-vivo studies. Further developments include automated

  5. Imaging cellular dynamics in vivo with multicolor fluorescent proteins

    NASA Astrophysics Data System (ADS)

    Hoffman, Robert M.

    2005-04-01

    The new field of in vivo cell biology is being developed with multi-colored fluorescent proteins. With the use of fluorescent proteins, the behavior of individual cells can be visualized in the living animal. An example of the new cell biology is dual-color fluorescence imaging using red fluorescent protein (RFP)-expressing tumors transplanted in green fluorescent protein (GFP)-expressing transgenic mice. These models show with great clarity the details of the tumor-stroma cell-cell interaction especially tumor-induced angiogenesis, tumor-infiltrating lymphocytes, stromal fibroblasts and macrophages. Another example is the color-coding of cells with RFP or GFP such that both cell types and their interaction can be simultaneously visualized in vivo. Stem cells can also be visualized and tracked in vivo with fluorescent proteins. Mice, in which the regulatory elements of the stem-cell marker nestin drive GFP expression, can be used to visualize hair follicle stem cells including their ability to form hair follicles as well as blood vessels. Dual-color cells expressing GFP in the nucleus and RFP in the cytoplasm enable real-time visualization of nuclear-cytoplasm dynamics including cell cycle events and apoptosis. Dual-color cells also enable the in vivo imaging of cell and nuclear deformation as well as trafficking in capillaries in living animals. Multiple-color labeling of cells will enable multiple events to be simultaneously visualized in vivo including cell-cell interaction, gene expression, ion fluxes, protein and organelle trafficking, chromosome dynamics and numerous other processes currently still studied in vitro.

  6. Determination of Optimal Rhodamine Flurophore for In Vivo Optical Imaging

    PubMed Central

    Longmire, Michelle; Ogawa, Mikako; Hama, Yukihiro; Kosaka, Nobuyuki; Regino, Celeste A.S.; Choyke, Peter L.; Kobayashi, Hisataka

    2009-01-01

    Optical imaging has the potential to improve the efficacy of surgical and endoscopic approaches to cancer treatment; however, the optimal type of fluorescent probe has not yet been established. It is well known that rhodamine-core-derived fluorophores offer a combination of desirable properties such as good photostability, high extinction coefficient, and high fluorescence quantum yield. However, despite the ubiquitous use of rhodamine fluorophores for in vivo optical imaging, it remains to be determined, however, if unique chemical properties among individual rhodamine core family members affect fluorophore parameters critical to in vivo optical imaging applications. These parameters include: preserved fluorescence intensity in low pH environments, similar to that of the endolysosome; efficient fluorescence signal despite conformational changes to targeting proteins as may occur in harsh subcellular environments; persistence of fluorescence after cellular internalization; and sufficient signal-to-background ratios to permit the identification of fluorophore-targeted tumors. In the present study, we conjugated 4 common rhodamine-core based fluorescent dyes to a clinically feasible and quickly internalizing D-galactose receptor targeting reagent, galactosamine serum albumin (GmSA), and conducted a series of in vitro and in vivo experiments using a metastatic ovarian cancer mouse model to determine if differences exist among rhodamine fluorophores and if so, which rhodamine core possesses optimal characteristics for in vivo imaging applications. Herein, we demonstrate that the rhodamine-fluorophore, TAMRA, is the most robust of the 4 common rhodamine fluorophores for in vivo optical imaging of ovarian cancer metastases to the peritoneum. PMID:18610943

  7. In Vivo Multiphoton Microscopy of Basal Cell Carcinoma

    PubMed Central

    Balu, Mihaela; Zachary, Christopher B.; Harris, Ronald M.; Krasieva, Tatiana B.; König, Karsten; Tromberg, Bruce J.; Kelly, Kristen M.

    2015-01-01

    Importance Basal cell carcinomas (BCCs) are diagnosed by clinical evaluation, which can include dermoscopic evaluation, biopsy, and histopathologic examination. Recent translation of multiphoton microscopy (MPM) to clinical practice raises the possibility of noninvasive, label-free in vivo imaging of BCCs that could reduce the time from consultation to treatment. Objectives To demonstrate the capability of MPM to image in vivo BCC lesions in human skin, and to evaluate if histopathologic criteria can be identified in MPM images. Design, Setting, and Participants Imaging in patients with BCC was performed at the University of California–Irvine Health Beckman Laser Institute & Medical Clinic, Irvine, between September 2012 and April 2014, with a clinical MPM-based tomograph. Ten BCC lesions were imaged in vivo in 9 patients prior to biopsy. The MPM images were compared with histopathologic findings. Main Outcomes and Measures MPM imaging identified in vivo and noninvasively the main histopathologic feature of BCC lesions: nests of basaloid cells showing palisading in the peripheral cell layer at the dermoepidermal junction and/or in the dermis. Results The main MPM feature associated with the BCC lesions involved nests of basaloid cells present in the papillary and reticular dermis. This feature correlated well with histopathologic examination. Other MPM features included elongated tumor cells in the epidermis aligned in 1 direction and parallel collagen and elastin bundles surrounding the tumors. Conclusions and Relevance This study demonstrates, in a limited patient population, that noninvasive in vivo MPM imaging can provide label-free contrast that reveals several characteristic features of BCC lesions. Future studies are needed to validate the technique and correlate MPM performance with histopathologic examination. PMID:25909650

  8. Generalized EPID calibration for in vivo transit dosimetry.

    PubMed

    Fidanzio, Andrea; Cilla, Savino; Greco, Francesca; Gargiulo, Laura; Azario, Luigi; Sabatino, Domenico; Piermattei, Angelo

    2011-01-01

    Many researchers are studying new in vivo dosimetry methods based on the use of Elelctronic portal imaging devices (EPIDs) that are simple and efficient in their daily use. However the need of time consuming implementation measurements with solid water phantoms for the in vivo dosimetry implementation can discourage someone in their use. In this paper a procedure has been proposed to calibrate aSi EPIDs for in vivo transit dosimetry. The dosimetric equivalence of three aSi Varian EPIDs has been investigated in terms of signal reproducibility and long term stability, signal linearity with MU and dose per pulse and signal dependence on the field dimensions. The signal reproducibility was within ± 0.5% (2SD), while the long term signal stability has been maintained well within ± 2%. The signal linearity with the monitor units (MU) was within ± 2% and within ± 0.5% for the EPIDs controlled by the IAS 2, and IAS 3 respectively. In particular it was verified that the correction factor for the signal linearity with the monitor units, k(lin), is independent of the beam quality, and the dose per pulse absorbed by the EPID. For 6, 10 and 15 MV photon beams, a generalized set of correlation functions F(TPR,w,L) and empirical factors f(TPR,d,L) as a function of the Tissue Phantom Ratio (TPR), the phantom thickness, w, the square field side, L, and the distance, d, between the phantom mid-plane and the isocentre were determined to reconstruct the isocenter dose. The tolerance levels of the present in vivo dosimetry method ranged between ± 5% and ± 6% depending on the tumor body location. In conclusion, the procedure proposed, that use generalized correlation functions, reduces the effort for the in vivo dosimetry method implementation for those photon beams with TPR within ± 0.3% as respect those here used.

  9. Exploring the case for assisted dying in the UK.

    PubMed

    Haigh, Carol

    This article discusses the concepts of euthanasia, assisted suicide and physician-assisted suicide, under the umbrella term of assisted dying, from a pro-assisted dying perspective. It outlines the key principles underpinning the debate around assisted dying and refutes the main arguments put forward by those opposing legalisation of assisted dying in the UK.

  10. Apoptosis-inducing effect of a palladium(II) saccharinate complex of terpyridine on human breast cancer cells in vitro and in vivo.

    PubMed

    Ari, Ferda; Cevatemre, Buse; Armutak, Elif Ilkay Ikitimur; Aztopal, Nazlihan; Yilmaz, Veysel T; Ulukaya, Engin

    2014-09-01

    The anti-growth effect of a palladium(II) complex-[PdCl(terpy)](sac)·2H2O] (sac=saccharinate, and terpy=2,2':6',2″-terpyridine)-was tested against human breast cancer cell lines, MCF-7 and MDA-MB-231. Anti-growth effect was assayed by the MTT and ATP viability assays in vitro and then confirmed on Balb/c mice in vivo. The mode of cell death was determined by both histological and biochemical methods. The Pd(II) complex had anti-growth effect on a dose dependent manner in vitro and in vivo. The cells died by apoptosis as evidenced by the pyknotic nucleus, cleavage of poly-(ADP-ribose) polymerase (PARP) and induction of active caspase-3. These results suggest that the palladium(II) saccharinate complex of terpyridine represents a potentially active novel complex for the breast cancer treatment, thus warrants further studies.

  11. In vitro and in vivo activities of piperacillin-tazobactam and meropenem at different inoculum sizes of ESBL-producing Klebsiella pneumoniae.

    PubMed

    Harada, Y; Morinaga, Y; Kaku, N; Nakamura, S; Uno, N; Hasegawa, H; Izumikawa, K; Kohno, S; Yanagihara, K

    2014-11-01

    The inoculum effect is a laboratory phenomenon in which the minimal inhibitory concentration (MIC) of an antibiotic is increased when a large number of organisms are exposed. Due to the emergence of extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-Kpn) infections, the inoculum effect of ESBL-Kpn on β-lactams was studied in vitro and in vivo using an experimental model of pneumonia. The in vitro inoculum effect of 45 clinical ESBL-Kpn isolates on β-lactams was evaluated at standard (10(5) CFU/mL) and high (10(7) CFU/mL) organism concentrations. The MIC50 of piperacillin-tazobactam, cefotaxime and cefepime was increased eight-fold or more and that of meropenem was increased two-fold. The in vivo inoculum effect was evaluated in an ESBL-Kpn pneumonia mouse model treated with bacteriostatic effect-adjusted doses of piperacillin-tazobactam (1000 mg/kg four times daily, %T>MIC; 32.60%) or meropenem (100 mg/kg twice daily, %T>MIC; 28.65%) at low/standard (10(4) CFU/mouse) and high (10(6) CFU/mouse) inocula. In mice administered a low inoculum, no mice died after treatment with piperacillin-tazobactam or meropenem, whereas all the control mice died. In contrast, in the high inoculum model, all mice in the piperacillin-tazobactam-treated group died, whereas all meropenem-treated mice survived and had a decreased bacterial load in the lungs and no invasion into the blood. In conclusion, meropenem was more resistant to the inoculum effect of ESBL-Kpn than piperacillin-tazobactam both in vitro and in vivo. In the management of severe pneumonia caused by ESBL-Kpn, carbapenems may be the drugs of choice to achieve a successful outcome.

  12. Killing, letting die and moral perception.

    PubMed

    Gillett, Grant

    1994-10-01

    There are a number of arguments that purport to show, in general terms, that there is no difference between killing and letting die. These are used to justify active euthanasia on the basis of the reasons given for allowing patients to die. I argue that the general and abstract arguments fail to take account of the complex and particular situations which are found in the care of those with terminal illness. When in such situations, there are perceptions and intuitions available that do not easily find propositional form but lead most of those whose practice is in the care of the dying to resist active euthanasia. I make a plea for their intuitions to be heeded above the sterile voice of abstract premises and arguments by examining the completeness of the outline form of the pro-euthanasia argument. In doing so, I make use of Nussbaum's discussion of moral perception and general claims to be found in the literature of moral particularism.

  13. CAE Based Die Face Engineering Development to Contribute to the Revitalization of the Tool & Die Industry

    NASA Astrophysics Data System (ADS)

    Tang, Arthur; Lee, Wing C.; St. Pierre, Shawn; He, Jeanne; Liu, Kesu; Chen, Chin C.

    2005-08-01

    Over the past two decades, the Computer Aided Engineering (CAE) tools have emerged as one of the most important engineering tools in various industries, due to its flexibility and accuracy in prediction. Nowadays, CAE tools are widely used in the sheet metal forming industry to predict the forming feasibility of a wide variety of complex components, ranging from aerospace and automotive components to household products. As the demand of CAE based formability accelerates, the need for a robust and streamlined die face engineering tool becomes more crucial, especially in the early stage when the tooling layout is not available, but a product design decision must be made. Ability to generate blank, binder and addendum surfaces with an appropriate layout of Drawbead, Punch Opening Line, Trim Line are the primary features and functions of a CAE based die face engineering tool. Once the die face layout is ready, a formability study should be followed to verify the die face layout is adequate to produce a formable part. If successful, the established die face surface should be exported back to the CAD/CAM environment to speed up the tooling and manufacturing design process with confidence that this particular part is formable with this given die face. With a CAE tool as described above, the tool & die industry will be greatly impacted as the processes will enable the bypass of hardware try-out and shorten the overall vehicle production timing. The trend has shown that OEMs and first tiers will source to low cost producers in the world which will have a negative impact to the traditional tool & die makers in the developed countries. CAE based tool as described should be adopted, along with many other solutions, in order to maintain efficiency of producing high quality product and meeting time-to-market requirements. This paper will describe how a CAE based die face engineering (DFE) tool could be further developed to enable the traditional tool & die makers to meet the

  14. Caspase 3 in dying tumor cells mediates post-irradiation angiogenesis

    PubMed Central

    Zhang, Zhengxiang; Yu, Yang; Cheng, Jin; Gong, Yanping; Li, Chuan-Yuan; Huang, Qian

    2015-01-01

    Cytotoxic radiotherapy unfavorably induces tumor cells to generate various proangiogenic substances, promoting post-irradiation angiogenesis (PIA), which is one of major causes of radiotherapy failure. Though several studies have reported some mechanisms behind PIA, they have not yet described the beginning proangiogenic motivator buried in the irradiated microenvironment. In this work, we revealed that dying tumor cells induced by irradiation prompted PIA via a caspase 3 dependent mechanism. Proteolytic inactivation of caspase 3 in dying tumor cells by transducing a dominant-negative version weakened proangiogenic effects in vitro and in vivo. In addition, inhibition of caspase 3 activity suppressed tumor angiogenesis and tumorigenesis in xenograft mouse model. Importantly, we identified vascular endothelial growth factor (VEGF)-A as a downstream proangiogenic factor regulated by caspase 3 possibly through Akt signaling. Collectively, these findings indicated that besides acting as a key executioner in apoptosis, caspase 3 in dying tumor cells may play a central role in driving proangiogenic response after irradiation. Thus, radiotherapy in combination with caspase 3 inhibitors may be a novel promising therapeutic strategy to reduce tumor recurrence due to restrained PIA. PMID:26431328

  15. Design and in vivo evaluation of oxycodone once-a-day controlled-release tablets

    PubMed Central

    Kim, Ju-Young; Lee, Sung-Hoon; Park, Chun-Woong; Rhee, Yun-Seok; Kim, Dong-Wook; Park, Junsang; Lee, Moonseok; Seo, Jeong-Woong; Park, Eun-Seok

    2015-01-01

    The aim of present study was to design oxycodone once-a-day controlled-release (CR) tablets and to perform in vitro/in vivo characterizations. Release profiles to achieve desired plasma concentration versus time curves were established by using simulation software and reported pharmacokinetic parameters of the drug. Hydroxypropyl methylcellulose (HPMC) 100,000 mPa·s was used as a release modifier because the polymer was found to be resistant to changes in conditions of the release study, including rotation speed of paddle and ion strength. The burst release of the drug from the CR tablets could be suppressed by applying an additional HPMC layer as a physical barrier. Finally, the oxycodone once-a-day tablet was comprised of two layers, an inert HPMC layer and a CR layer containing drug and HPMC. Commercial products, either 10 mg bis in die (bid [twice a day]) or once-a-day CR tablets (20 mg) were administered to healthy volunteers, and calculated pharmacokinetic parameters indicated bioequivalence of the two different treatments. The findings of the present study emphasize the potential of oxycodone once-a-day CR tablets for improved patient compliance, safety, and efficacy, which could help researchers to develop new CR dosage forms of oxycodone. PMID:25678774

  16. Autophagy inhibition radiosensitizes in vitro, yet reduces radioresponses in vivo due to deficient immunogenic signalling

    PubMed Central

    Ko, A; Kanehisa, A; Martins, I; Senovilla, L; Chargari, C; Dugue, D; Mariño, G; Kepp, O; Michaud, M; Perfettini, J-L; Kroemer, G; Deutsch, E

    2014-01-01

    Clinical oncology heavily relies on the use of radiotherapy, which often leads to merely transient responses that are followed by local or distant relapse. The molecular mechanisms explaining radioresistance are largely elusive. Here, we identified a dual role of autophagy in the response of cancer cells to ionizing radiation. On one hand, we observed that the depletion of essential autophagy-relevant gene products, such as ATG5 and Beclin 1, increased the sensitivity of human or mouse cancer cell lines to irradiation, both in vitro (where autophagy inhibition increased radiation-induced cell death and decreased clonogenic survival) and in vivo, after transplantation of the cell lines into immunodeficient mice (where autophagy inhibition potentiated the tumour growth-inhibitory effect of radiotherapy). On the other hand, when tumour proficient or deficient for autophagy were implanted in immunocompetent mice, it turned out that defective autophagy reduced the efficacy of radiotherapy. Indeed, radiotherapy elicited an anti-cancer immune response that was dependent on autophagy-induced ATP release from stressed or dying tumour cells and was characterized by dense lymphocyte infiltration of the tumour bed. Intratumoural injection of an ecto-ATPase inhibitor restored the immune infiltration of autophagy-deficient tumours post radiotherapy and improved the growth-inhibitory effect of ionizing irradiation. Altogether, our results reveal that beyond its cytoprotective function, autophagy confers immunogenic properties to tumours, hence amplifying the efficacy of radiotherapy in an immunocompetent context. This has far-reaching implications for the development of pharmacological radiosensitizers. PMID:24037090

  17. Bromodeoxyuridine Inhibits Cancer Cell Proliferation In Vitro and In Vivo12

    PubMed Central

    Levkoff, Lindsay H; Marshall, Gregory P; Ross, Heather H; Caldeira, Maria; Reynolds, Brent A; Cakiroglu, Meryem; Mariani, Christopher L; Streit, Wolfgang J; Laywell, Eric D

    2008-01-01

    The thymidine analog bromodeoxyuridine (BrdU) is incorporated into newly synthesized DNA and has been shown to increase the susceptibility of incorporating cells to ionizing radiation. However, in the absence of secondary stressors, BrdU is thought to substitute relatively benignly for thymidine and is commonly used to “birth-date” proliferative cells. We report a novel antiproliferative effect of BrdU on cancer cells, which is independent of its role in radiosensitization. A single, brief in vitro exposure to BrdU induces a profound and sustained reduction in the proliferation rate of all cancer cells examined. Cells do not die but variably up-regulate some senescence-associated proteins as they accumulate in the G1 phase of the cell cycle. Bromodeoxyuridine also impairs the proliferative capacity of primary tumor-initiating human glioma cells and may therefore represent a means of targeting cancer stem cells. Finally, conservative in vivo BrdU regimens—in the absence of any other treatment—significantly suppress the progression of gliomas in the highly aggressive, syngeneic RG2 model. These results suggest that BrdU may have an important role as an adjunctive therapeutic for a wide variety of cancers based on new insights into its effect as a negative regulator of cell cycle progression. PMID:18680882

  18. Dendritic cell function in vivo during the steady state: a role in peripheral tolerance.

    PubMed

    Steinman, Ralph M; Hawiger, Daniel; Liu, Kang; Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Iyoda, Tomonori; Ravetch, Jeffrey; Dhodapkar, Madhav; Inaba, Kayo; Nussenzweig, Michel

    2003-04-01

    The avoidance of autoimmunity requires mechanisms to actively silence or tolerize self reactive T cells in the periphery. During infection, dendritic cells are not only capturing microbial antigens, but also are processing self antigens from dying cells as well as innocuous environmental proteins. Since the dendritic cells are maturing in response to microbial and other stimuli, peptides will be presented from both noxious and innocuous antigens. Therefore it would be valuable to have mechanisms whereby dendritic cells, prior to infection, establish tolerance to those self and environmental antigens that can be processed upon pathogen encounter. In the steady state, prior to acute infection and inflammation, dendritic cells are in an immature state and not fully differentiated to carry out their known roles as inducers of immunity. These immature cells are not inactive, however. They continuously circulate through tissues and into lymphoid organs, capturing self antigens as well as innocuous environmental proteins. Recent experiments have provided direct evidence that antigen-loaded immature dendritic in vivo silence T cells either by deleting them or by expanding regulatory T cells. In this way, it is proposed that the immune system overcomes at least some of the risk of developing autoimmunity and chronic inflammation. It is proposed that dendritic cells play a major role in defining immunologic self, not only centrally in the thymus but also in the periphery.

  19. A novel, cell-specific attenuation of a herpes simplex virus type 1 infection in vivo.

    PubMed

    Kienzle, T E; Chen, T M; Mrak, R E; Stroop, W G

    2001-04-01

    We have observed a cell-specific attenuation of herpes simplex virus type 1 strain 17syn+ in vivo that was dependent upon the cell type used to grow the virus. Direct corneal infection of rabbits with 17syn+ propagated in Vero cells caused 60% (6 of 10) to develop severe central nervous system (CNS) disease as evidenced by seizures and/or paralysis; all neurologically impaired rabbits died. In contrast, infection of rabbits with 17syn+ propagated in BHK-21 cells induced seizures and was fatal in 10% (1 of 10). The cell-specific attenuation of a 17syn+ occurred after one growth cycle in BHK-21 cells. To determine whether the decreased virulence of the BHK-21 cell-grown virus correlated with a less severe CNS inflammatory reaction, CNS tissues from rabbits infected with 17syn+ grown in Vero and BHK-21 cells were compared. Histopathological analyses revealed no differences in the location or severity of inflammatory lesions from rabbits infected with virus grown in either cell type. Virus-induced corneal disease was less dependent upon the cell type used to propagate the virus as there were no significant differences in the type or severity of observed corneal lesions. Possible explanations based on differences between Vero and BHK-21 cells are discussed.

  20. Die Europäische Union, die Europäische Gemeinschaft und ihre Rechtsordnung, die Europäische Lebensmittelkontrolle

    NASA Astrophysics Data System (ADS)

    Gallhoff, Gudrun; Rimkus, Gerhard G.

    Die Europäische Union (EU) ist ein Zusammenschluss von siebenundzwanzig unabhängigen Staaten, um deren wirtschaftliche, politische und soziale Zusammenarbeit zu verstärken. Seit 1. Mai 2007 hat sie die folgenden Mitglieder: Österreich, Belgien, Bulgarien, Dänemark, Finnland, Frankreich, Deutschland, Griechenland, Irland, Italien, Luxemburg, die Niederlande, Portugal, Spanien, Schweden, das Vereinigte Königreich von Großbritannien und Nordirland, Zypern, die Tschechische Republik, Estland, Ungarn, Lettland, Litauen, Malta, Polen, Rumänien, die Slowakei und Slowenien [1]. (Hinweis: Die Republik Zypern hat juristisch Souveränität über die ganze Insel, da die Türkische Republik Nordzypern international nicht anerkannt wird.)

  1. Die casting die deflections: Prediction and attenuation. Final report, July 1, 1995--September 30, 1997

    SciTech Connect

    Miller, R.A.; Ahuett-Garza, H.; Choudhury, A.K.; Dedhia, S.

    1998-05-01

    This report summarizes two years of research intended to develop methods to model and predict the deflection patterns in die casting dies. No comprehensive analysis of this type had previously been completed. The die casting process is complex and involves numerous mechanical and thermal phenomena that effect the mechanical behavior of the die. A critical activity in this work was sorting out and evaluating the relative contributions of the various mechanisms to die deflections. This evaluation was accomplished through a series of simple engineering analyses based primarily on the order of magnitude of the influence of each load considered on die deflections. A modeling approach incorporating commercially available finite element analysis software was developed and tested. The model evolved by testing simple models against more comprehensive models and against the limited experimental data that is available. The development of the modeling approach lead to consideration of the die casting machine in more detail than was originally anticipated. The machine is critical and cannot be ignored. A simplified model described as a spring/platen model was developed to account for the machine platens, tie bars, and toggles. The characteristics of this model are described and predictions based on this model are compared against full machine models and measured deflections of machine platens. Details of the modeling approach and the various case studies are provided in the report and in several publications that have resulted from the work.

  2. Wissenschaft, die unsere Kultur verändert. Tiefenschichten des Streits um die Evolutionstheorie

    NASA Astrophysics Data System (ADS)

    Patzelt, Werner J.

    Die Evolutionstheorie ist eine der erfolgreichsten wissenschaftlichen Theorien. Sie erlaubt es, unsere Herkunft zu verstehen und riskante Merkmale gerade der menschlichen Spezies zu begreifen. Zugleich ist die Evolutionstheorie eine der umstrittensten Theorien. Das liegt nicht an ihrer empirischen Tragfähigkeit, sondern an ihrem Gegenstand. Sie handelt nämlich nicht nur - wie Hunderte andere wissenschaftliche Theorien - von der "Welt da draußen“, sondern vor allem auch von uns selbst und von unserem Platz in dieser Welt. Den einen gilt sie obendrein als Überwinderin religiösen Aberglaubens, den anderen als neuer Zugang zu Gott und seinem Wirken in der Welt. Ferner sehen die einen in der Evolution eine unbezweifelbare Tatsache gleich der Schwerkraft oder dem Holocaust, die anderen aber eine - noch oder dauerhaft - unbewiesene Hypothese oder gar eine falsche Schöpfungslehre. Und während die meisten Streitfragen solcher Art nach wechselseitig akzeptierten Regeln ‚normaler Wissenschaft‘ geklärt werden, wird bei der Frage nach dem Woher unserer Spezies und Kultur die intellektuelle Zuständigkeit von Wissenschaft mitunter überhaupt bezweifelt. Anscheinend geht es schon um recht tiefe Schichten unserer Kultur und nicht nur der wissenschaftlichen, wenn - wie seit 150 Jahren - um die Evolutionstheorie gestritten wird. Wie sehen diese Schichten aus?

  3. Effect of Die Strength and Work Piece Strength on the Wear of Hot Forging Dies

    NASA Astrophysics Data System (ADS)

    Levy, B. S.; Van Tyne, C. J.

    2015-01-01

    The effect of the strength ratio extracted from an Archard model for wear is used to describe the wear rates expected in hot forging dies. In the current study, the strength ratio is the strength of the hot forging die to the strength of the work piece. Three hot forging die steels are evaluated. The three die steels are FX, 2714, and WF. To determine the strength of the forging die, a continuous function has been developed that describes the yield strength of three die steels for temperatures from 600 to 700 °C and for times up to 20 h (i.e., tempering times of up to 20 h). The work piece material is assumed to be AISI 1045. Based on the analysis, the wear resistance of WF should be superior and FX should be slightly better than 2714. Decreasing the forging temperature increases the strength ratio, because the strength of the die surface increases faster than the flow strength of AISI 1045. The increase in the strength ratio indicates a decrease in the expected wear rate.

  4. Investigation of Die Stress Profiles during Powder Compaction using Instrumented Die

    SciTech Connect

    Hong, Sung-tae; Hovanski, Yuri; Lavender, Curt A.; Weil, K. Scott

    2008-06-01

    The radial stress profile in a cylindrical die during compaction of titanium (Ti) powder was investigated by experiments. The concept of an instrumented die was extended to design an enhanced instrumented die. Custom-made strain gage pins were used to measure the radial stress during powder compaction. The test fixture was designed to simulate double-action pressing. The measured die stress profile for Ti powder was compared with that for a commercially available iron (Fe) powder. The stress history shows that an appreciable residual stress remains in the die in the radial direction after the axial compaction stress is removed from the powder. Furthermore, the radial stress profile in the die, while under maximum axial compaction stress, is more uniform across the height of the Fe compact than that of the Ti compact. In addition, the residual stress profile in the die in the radial direction reduces symmetrically in both directions beyond the height of the compact for both powders. Finally, the Ti powder shows a significantly higher frictional coefficient at the maximum axial compaction stress, and consequently a higher maximum axial ejection stress than the Fe powder.

  5. Deformation properties of pharmaceutical excipients determined using an in-die and out-die method.

    PubMed

    Ilić, Ilija; Govedarica, Biljana; Šibanc, Rok; Dreu, Rok; Srčič, Stane

    2013-03-25

    This study investigated deformation mechanisms of some commonly used pharmaceutical fillers, such as microcrystalline cellulose, lactose, dicalcium phosphate, isomalt and cornstarch, using a combination of the in-die and out-die method with the Heckel and Walker models. The tableting mixtures contained of 98.5% (w/w) filler, the rest consisted of dry binder and an antiadhesive agent. Our results showed that plasticity and elasticity may be considered independent deformation properties as highly plastic materials (microcrystalline cellulose, cornstarch) also exhibited high elasticity. Particular emphasis was placed on explaining the differences observed between the in-die and out-die method-comparison revealed that the differences are a consequence of the material's elastic properties. Larger error of in-die results can be expected for more elastic materials, and thus in-die Heckel should be used with some considerations. In contrast, the Walker model was found to be more robust and smaller differences were observed between the two methods. We consider the most correct results to have been obtained by the out-die approach, which excludes the elastic properties of the material evaluated. An excellent correlation between elastic determination at the single-particle level and multiple-particle scale was demonstrated, suggesting a great potential of nanoscale determination of a material's mechanical properties for better elucidation of deformation mechanisms.

  6. In vivo photoacoustic imaging of model of port wine stains.

    PubMed

    Yuan, Kaihua; Yuan, Yi; Gu, Ying; Gao, Jianhua; Xing, Da

    2012-01-01

    Port wine stains are categorized as a benign capillary vascular malformation, which is hard to cure. In this paper, a photoacoustic microscopy system, which integrated a two-dimensional scanning galvanometer, an objective lens and a focused ultrasound transducer, was designed for noninvasive imaging of blood vessels of port wine stains model in vivo. Cock comb was chosen as the port wine stains model in the experiment. The blood vessels in x-y plane and x-z plane were imaged clearly. Experimental results demonstrate that photoacoustic microscopy can image the blood vessels of port wine stains model in vivo with high contrast and high resolution. It has the potential for clinical applications in detecting the blood vessels in port wine stains skin.

  7. High-Resolution Multiphoton Imaging of Tumors In Vivo

    PubMed Central

    Wyckoff, Jeffrey; Gligorijevic, Bojana; Entenberg, David; Segall, Jeffrey; Condeelis, John

    2014-01-01

    Analysis of the individual steps in metastasis is crucial if insights at the molecular level are to be linked to the cell biology of cancer. A technical hurdle to achieving the analysis of the individual steps of metastasis is the fact that, at the gross level, tumors are heterogeneous in both animal models and patients. Human primary tumors show extensive variation in all properties ranging from growth and morphology of the tumor through tumor-cell density in the blood and formation and growth of metastases. Methods capable of the direct visualization and analysis of tumor-cell behavior at single-cell resolution in vivo have become crucial in advancing the understanding of mechanisms of metastasis, the definition of microenvironment, and the markers related to both. This article discusses the use of high-resolution multiphoton imaging of tumors (specifically breast tumors in mice) in vivo. PMID:21969629

  8. Three-Dimensional Cell Culture: A Breakthrough in Vivo

    PubMed Central

    Antoni, Delphine; Burckel, Hélène; Josset, Elodie; Noel, Georges

    2015-01-01

    Cell culture is an important tool for biological research. Two-dimensional cell culture has been used for some time now, but growing cells in flat layers on plastic surfaces does not accurately model the in vivo state. As compared to the two-dimensional case, the three-dimensional (3D) cell culture allows biological cells to grow or interact with their surroundings in all three dimensions thanks to an artificial environment. Cells grown in a 3D model have proven to be more physiologically relevant and showed improvements in several studies of biological mechanisms like: cell number monitoring, viability, morphology, proliferation, differentiation, response to stimuli, migration and invasion of tumor cells into surrounding tissues, angiogenesis stimulation and immune system evasion, drug metabolism, gene expression and protein synthesis, general cell function and in vivo relevance. 3D culture models succeed thanks to technological advances, including materials science, cell biology and bioreactor design. PMID:25768338

  9. Label-free oxygen-metabolic photoacoustic microscopy in vivo

    NASA Astrophysics Data System (ADS)

    Yao, Junjie; Maslov, Konstantin I.; Zhang, Yu; Xia, Younan; Wang, Lihong V.

    2011-07-01

    Almost all diseases, especially cancer and diabetes, manifest abnormal oxygen metabolism. Accurately measuring the metabolic rate of oxygen (MRO2) can be helpful for fundamental pathophysiological studies, and even early diagnosis and treatment of disease. Current techniques either lack high resolution or rely on exogenous contrast. Here, we propose label-free metabolic photoacoustic microscopy (mPAM) with small vessel resolution to noninvasively quantify MRO2 in vivo in absolute units. mPAM is the unique modality for simultaneously imaging all five anatomical, chemical, and fluid-dynamic parameters required for such quantification: tissue volume, vessel cross-section, concentration of hemoglobin, oxygen saturation of hemoglobin, and blood flow speed. Hyperthermia, cryotherapy, melanoma, and glioblastoma were longitudinally imaged in vivo. Counterintuitively, increased MRO2 does not necessarily cause hypoxia or increase oxygen extraction. In fact, early-stage cancer was found to be hyperoxic despite hypermetabolism.

  10. In vivo photoacoustic imaging of osteosarcoma in a rat model

    NASA Astrophysics Data System (ADS)

    Hu, Jun; Yu, Menglei; Ye, Fei; Xing, Da

    2011-02-01

    Osteosarcoma is one of the most common primary malignant tumors of the bone and the second leading cause of cancer-related deaths in the pediatric age group. Confirmed diagnosis and prompt treatment of osteosarcoma are critical for effective prognosis. In this study, we investigate the application of photoacoustic imaging (PAI) for the detection of osteosarcoma in an animal model. Cross-section images of a normal rat leg and a tumorous rat leg were successfully reconstructed in vivo. Morphological changes and the development of the implanted osteosarcoma were accurately mapped with time-dependent photoacoustic images. Furthermore, we evaluate the use of gold nanorods as contrast agents for imaging osteosarcoma with PAI. This is the first study that uses PAI to detect osteosarcoma in vivo, and the results suggest that PAI has the potential clinical application for detecting osteosarcoma in the early stage.

  11. In vivo surface roughness evolution of a stressed metallic implant

    NASA Astrophysics Data System (ADS)

    Tan, Henry

    2016-10-01

    Implant-associated infection, a serious medical issue, is caused by the adhesion of bacteria to the surface of biomaterials; for this process the surface roughness is an important property. Surface nanotopography of medical implant devices can control the extent of bacterial attachment by modifying the surface morphology; to this end a model is introduced to facilitate the analysis of a nanoscale smooth surface subject to mechanical loading and in vivo corrosion. At nanometre scale rough surface promotes friction, hence reduces the mobility of the bacteria; this sessile environment expedites the biofilm growth. This manuscript derives the controlling equation for surface roughness evolution for metallic implant subject to in-plane stresses, and predicts the in vivo roughness changes within 6 h of continued mechanical loading at different stress level. This paper provides analytic tool and theoretical information for surface nanotopography of medical implant devices.

  12. In Vivo Assessment of Muscle Contractility in Animal Studies.

    PubMed

    Iyer, Shama R; Valencia, Ana P; Hernández-Ochoa, Erick O; Lovering, Richard M

    2016-01-01

    In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies. Animal models provide unmitigated access to histological samples, which provide a "direct measure" of damage. However, even with unconstrained access to tissue morphology and biochemistry assays, the findings typically do not account for loss of muscle function. Thus, the most comprehensive measure of the overall health of the muscle is assessment of its primary function, which is to produce contractile force. The majority of animal models testing contractile force have been limited to the muscle groups moving the ankle, with advantages and disadvantages depending on the equipment. Here, we describe in vivo methods to measure torque, to produce a reliable muscle injury, and to follow muscle function within the same animal over time. We also describe in vivo methods to measure tension in the leg and thigh muscles.

  13. In Vivo Flow Cytometry: A Horizon of Opportunities

    PubMed Central

    Tuchin, Valery V.; Tárnok, Attila; Zharov, Vladimir P.

    2012-01-01

    Flow cytometry has been a fundamental tool of biological discovery for many years. Invasive extraction of cells from a living organism, however, may lead to changes in cell properties and prevents studying cells in their native environment. These problems can be overcome by use of in vivo flow cytometry which provides detection and imaging of circulating normal and abnormal cells directlyin blood or lymph flow. The goal of this mini-review is to provide a brief history, features and challenges of this new generation of flow cytometry methods and instruments. Spectrum of possibilities of in vivo flow cytometry in biological science (e.g., cell metabolism, immune function, or apoptosis) and medical fields (e.g., cancer, infection, cardiovascular disorder) including integrated photoacoustic-photothermal theranostics of circulating abnormal cells are discussed with focus on recent advances of this new platform. PMID:21915991

  14. Improved in vivo stability of actinium-225 macrocyclic complexes.

    PubMed

    Deal, K A; Davis, I A; Mirzadeh, S; Kennel, S J; Brechbiel, M W

    1999-07-29

    The favorable nuclear properties of actinium-225 ((225)Ac) have led to proposal of this isotope for use in radioimmunotherapy. In an effort to reduce the toxicity of free (225)Ac, a series of ligands were evaluated for stability in vivo. Loss of (225)Ac from acyclic chelating agents resulted in high liver uptake and poor whole body clearance. The macrocyclic ligands c-DOTA, PEPA, and HEHA were evaluated, and (225)Ac-HEHA showed exceptional stability in vivo. (225)Ac chelated with EDTA, DTPA, DOTA, or PEPA permitted substantial accumulation of the radionuclide to the liver, while the (225)Ac-HEHA complex was essentially excreted within minutes of administration. The preparation of the ligands and radiolabeled complexes and the biodistribution results will be discussed.

  15. 19F MRI for quantitative in vivo cell tracking

    PubMed Central

    Srinivas, Mangala; Heerschap, Arend; Ahrens, Eric T.; Figdor, Carl G.; de Vries, I. Jolanda M.

    2010-01-01

    Cellular therapy, including stem cell transplants and dendritic cell vaccines, is typically monitored for dosage optimization, accurate delivery and localization using non-invasive imaging, of which magnetic resonance imaging (MRI) is a key modality. 19F MRI retains the advantages of MRI as an imaging modality, while allowing direct detection of labelled cells for unambiguous identification and quantification, unlike typical metal-based contrast agents. Recent developments in 19F MRI-based in vivo cell quantification, the existing clinical use of 19F compounds and current explosive interest in cellular therapeutics have brought 19F imaging technology closer to clinical application. We review the application of 19F MRI to cell tracking, discussing intracellular 19F labels, cell labelling and in vivo quantification, as well as the potential clinical use of 19F MRI. PMID:20427096

  16. The zebrafish: scalable in vivo modeling for systems biology

    PubMed Central

    Deo, Rahul C.; MacRae, Calum A.

    2011-01-01

    The zebrafish offers a scalable vertebrate model for many areas of biologic investigation. There is substantial conservation of genetic and genomic features and, at a higher order, conservation of intermolecular networks, as well as physiologic systems and phenotypes. We highlight recent work demonstrating the extent of this homology, and efforts to develop high-throughput phenotyping strategies suited to genetic or chemical screening on a scale compatible with in vivo validation for systems biology. We discuss the implications of these approaches for functional annotation of the genome, elucidation of multicellular processes in vivo, and mechanistic exploration of hypotheses generated by a broad range of ‘unbiased’ ‘omic technologies such as expression profiling and genome-wide association. Finally, we outline potential strategies for the application of the zebrafish to the systematic study of phenotypic architecture, disease heterogeneity and drug responses. PMID:20882534

  17. Molecular approaches for manipulating astrocytic signaling in vivo

    PubMed Central

    Xie, Alison X.; Petravicz, Jeremy; McCarthy, Ken D.

    2015-01-01

    Astrocytes are the predominant glial type in the central nervous system and play important roles in assisting neuronal function and network activity. Astrocytes exhibit complex signaling systems that are essential for their normal function and the homeostasis of the neural network. Altered signaling in astrocytes is closely associated with neurological and psychiatric diseases, suggesting tremendous therapeutic potential of these cells. To further understand astrocyte function in health and disease, it is important to study astrocytic signaling in vivo. In this review, we discuss molecular tools that enable the selective manipulation of astrocytic signaling, including the tools to selectively activate and inactivate astrocyte signaling in vivo. Lastly, we highlight a few tools in development that present strong potential for advancing our understanding of the role of astrocytes in physiology, behavior, and pathology. PMID:25941472

  18. Applications of nuclear technologies for in-vivo elemental analysis

    SciTech Connect

    Cohn, S.H.; Ellis, K.J.; Vartsky, D.; Wielopolski, L.

    1982-01-01

    Measurement facilities developed, to date, include a unique whole-body-counter, (WBC); a total-body neutron-activation facility (TBNAA); and a partial-body activation facility (PBNAA). A variation of the prompt-gamma neutron-activation technique for measuring total-body nitrogen was developed to study body composition of cancer patients and the effect of nutritional regimens on the composition. These new techniques provide data in numerous clinical studies not previously amenable to investigation. The development and perfection of these techniques provide unique applications of radiation and radioisotopes to the early diagnosis of certain diseases and the evaluation of therapeutic programs. The PBNAA technique has been developed and calibrated for in-vivo measurement of metals. Development has gone forward on prompt-gamma neutron activation for the measurement of cadmium, x-ray fluorescence (XRF) for measurement of iron. Other techniques are being investigated for in-vivo measurement of metals such as silicon and beryllium.

  19. Variables influencing the frictional behaviour of in vivo human skin.

    PubMed

    Veijgen, N K; Masen, M A; van der Heide, E

    2013-12-01

    In the past decades, skin friction research has focused on determining which variables are important to affect the frictional behaviour of in vivo human skin. Until now, there is still limited knowledge on these variables. This study has used a large dataset to identify the effect of variables on the human skin, subject characteristics and environmental conditions on skin friction. The data are obtained on 50 subjects (34 males and 16 females). Friction measurements represent the friction between in vivo human skin and an aluminium sample, assessed on three anatomical locations. The coefficient of friction increased significantly (p<0.05) with increasing age, increasing ambient temperature and increasing relative air humidity. A significant inversely proportional relationship was found between friction and both the amount of hair present on the skin and the height of the subject. Other outcome variables in this study were the hydration of the skin and the skin temperature.

  20. In Vivo Assessment of Muscle Contractility in Animal Studies.

    PubMed

    Iyer, Shama R; Valencia, Ana P; Hernández-Ochoa, Erick O; Lovering, Richard M

    2016-01-01

    In patients with muscle injury or muscle disease, assessment of muscle damage is typically limited to clinical signs, such as tenderness, strength, range of motion, and more recently, imaging studies. Animal models provide unmitigated access to histological samples, which provide a "direct measure" of damage. However, even with unconstrained access to tissue morphology and biochemistry assays, the findings typically do not account for loss of muscle function. Thus, the most comprehensive measure of the overall health of the muscle is assessment of its primary function, which is to produce contractile force. The majority of animal models testing contractile force have been limited to the muscle groups moving the ankle, with advantages and disadvantages depending on the equipment. Here, we describe in vivo methods to measure torque, to produce a reliable muscle injury, and to follow muscle function within the same animal over time. We also describe in vivo methods to measure tension in the leg and thigh muscles. PMID:27492180

  1. Non-contact intracellular binding of chloroplasts in vivo

    NASA Astrophysics Data System (ADS)

    Li, Yuchao; Xin, Hongbao; Liu, Xiaoshuai; Li, Baojun

    2015-06-01

    Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner.

  2. Non-contact intracellular binding of chloroplasts in vivo.

    PubMed

    Li, Yuchao; Xin, Hongbao; Liu, Xiaoshuai; Li, Baojun

    2015-06-04

    Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner.

  3. In vivo imaging of light-emitting probes

    NASA Astrophysics Data System (ADS)

    Rice, Bradley W.; Cable, Michael D.; Nelson, Michael B.

    2001-10-01

    In vivo imaging of cells tagged with light-emitting probes, such as firefly luciferase or fluorescent proteins, is a powerful technology that enables a wide range of biological studies in small research animals. Reporters with emission in the red to infrared (> 600 nm) are preferred due to the low absorption in tissue at these wavelengths. Modeling of photon diffusion through tissue indicates that bioluminescent cell counts as low as a few hundred can be detected subcutaneously, while approximately106 cells are required to detect signals at approximately 2 cm depth in tissue. Signal-to- noise estimates show that cooled back-thinned integrating charge coupled devices (CCDs) are preferred to image-intensified CCDs for this application, mainly due to their high quantum efficiency (approximately 85%) at wavelengths > 600 nm where tissue absorption is low. Instrumentation for in vivo imaging developed at Xenogen is described and several examples of images of mice with bioluminescent cells are presented.

  4. Near-infrared Molecular Probes for In Vivo Imaging

    PubMed Central

    Zhang, Xuan; Bloch, Sharon; Akers, Walter; Achilefu, Samuel

    2012-01-01

    Cellular and tissue imaging in the near-infrared (NIR) wavelengths between 700 and 900 nm is advantageous for in vivo because of the low absorption of biological molecules in this region. This Unit presents protocols for small animal imaging using planar and fluorescence lifetime imaging techniques. Included is an overview of NIR fluorescence imaging of cells and small animals using NIR organic fluorophores, nanoparticles, and multimodal imaging probes. The development, advantages, and application of NIR fluorescent probes that have been used for in vivo imaging are also summarized. The use of NIR agents in conjunction with visible dyes and considerations in selecting imaging agents are discussed. We conclude with practical considerations for the use of these dyes in cell and small animal imaging applications. PMID:22470154

  5. In vivo evaluation of matrix pellets containing nanocrystalline ketoprofen.

    PubMed

    Vergote, G J; Vervaet, C; Van Driessche, I; Hoste, S; De Smedt, S; Demeester, J; Jain, R A; Ruddy, S; Remon, J P

    2002-06-20

    The aim of this study was to evaluate the in-vivo behaviour of matrix pellets formulated with nanocrystalline ketoprofen after oral administration to dogs. No significant differences in AUC-values were seen between pellet formulations containing nanocrystalline or microcrystalline ketoprofen and a commercial ketoprofen formulation (reference: Rofenid 200 Long Acting). C(max) of the formulations containing nano- or microcrystalline ketoprofen was significantly higher compared to reference, whereas t(max) was significantly lower. The in-vivo burst release observed for the spray dried nanocrystalline ketoprofen matrix pellets was reduced following compression of the pellets in combination with placebo wax/starch pellets. These matrix tablets sustained the ketoprofen plasma concentrations during 5.6 and 5.4 h for formulations containing nano- and microcrystalline ketoprofen, respectively.

  6. Verapamil inhibits scar formation after peripheral nerve repair in vivo

    PubMed Central

    Han, A-chao; Deng, Jing-xiu; Huang, Qi-shun; Zheng, Huai-yuan; Zhou, Pan; Liu, Zhi-wei; Chen, Zhen-bing

    2016-01-01

    The calcium channel blocker, verapamil, has been shown to reduce scar formation by inhibiting fibroblast adhesion and proliferation in vitro. It was not clear whether topical application of verapamil after surgical repair of the nerve in vivo could inhibit the formation of excessive scar tissue. In this study, the right sciatic nerve of adult Sprague-Dawley rats was transected and sutured with No. 10-0 suture. The stoma was wrapped with gelfoam soaked with verapamil solution for 4 weeks. Compared with the control group (stoma wrapped with gelfoam soaked with physiological saline), the verapamil application inhibited the secretion of extracellular matrix from fibroblasts in vivo, suppressed type I and III collagen secretion and increased the total number of axons and the number of myelinated axons. These findings suggest that verapamil could reduce the formation of scar tissue and promote axon growth after peripheral nerve repair. PMID:27127494

  7. Recent molecular approaches to understanding astrocyte function in vivo

    PubMed Central

    Davila, David; Thibault, Karine; Fiacco, Todd A.; Agulhon, Cendra

    2013-01-01

    Astrocytes are a predominant glial cell type in the nervous systems, and are becoming recognized as important mediators of normal brain function as well as neurodevelopmental, neurological, and neurodegenerative brain diseases. Although numerous potential mechanisms have been proposed to explain the role of astrocytes in the normal and diseased brain, research into the physiological relevance of these mechanisms in vivo is just beginning. In this review, we will summarize recent developments in innovative and powerful molecular approaches, including knockout mouse models, transgenic mouse models, and astrocyte-targeted gene transfer/expression, which have led to advances in understanding astrocyte biology in vivo that were heretofore inaccessible to experimentation. We will examine the recently improved understanding of the roles of astrocytes – with an emphasis on astrocyte signaling – in the context of both the healthy and diseased brain, discuss areas where the role of astrocytes remains debated, and suggest new research directions. PMID:24399932

  8. High-resolution multiphoton imaging of tumors in vivo.

    PubMed

    Wyckoff, Jeffrey; Gligorijevic, Bojana; Entenberg, David; Segall, Jeffrey; Condeelis, John

    2011-10-01

    Analysis of the individual steps in metastasis is crucial if insights at the molecular level are to be linked to the cell biology of cancer. A technical hurdle to achieving the analysis of the individual steps of metastasis is the fact that, at the gross level, tumors are heterogeneous in both animal models and patients. Human primary tumors show extensive variation in all properties ranging from growth and morphology of the tumor through tumor-cell density in the blood and formation and growth of metastases. Methods capable of the direct visualization and analysis of tumor-cell behavior at single-cell resolution in vivo have become crucial in advancing the understanding of mechanisms of metastasis, the definition of microenvironment, and the markers related to both. This article discusses the use of high-resolution multiphoton imaging of tumors (specifically breast tumors in mice) in vivo.

  9. Liposomes of terbutaline sulphate: in vitro and in vivo studies.

    PubMed

    Joshi, M R; Misra, A N

    1999-09-01

    In vitro studies were conducted to understand the comparative drug diffusion pattern, across artificial membrane, of the drug and of the prepared liposomes of different liposomal membrane composition. In vivo studies were carried out to determine the extent and time-course of pulmonary tissue uptake of administered liposomes containing terbutaline sulphate(TER) on rat lungs. In vitro studies revealed that the drug released from the prepared liposomes obeys Higuchi's diffusion controlled model. Different loading doses and release patterns of drug from the liposomes can be obtained by altering the PC:CHOL ratio and incorporation of cholesterol was found to reduce permeability of the membrane. Similarly drug absorption in vivo in rat's lung following intratracheal instillation, prolonged over 12 hr by liposomal entrapment of TER. The findings of present investigation indicated that liposomally encapsulated TER can be used for pulmonary delivery for maximizing the therapeutic efficacy and reducing undesirable side effects. PMID:10687283

  10. Evidence that hematopoiesis may be a stochastic process in vivo.

    PubMed

    Abkowitz, J L; Catlin, S N; Guttorp, P

    1996-02-01

    To study the behavior of hematopoietic stem cells in vivo, hematopoiesis was simulated by assuming that all stem cell decisions (that is, replication, apoptosis, initiation of a differentiation/maturation program) were determined by chance. Predicted outcomes from simulated experiments were compared with data obtained in autologous marrow transplantation studies of glucose 6-phosphate dehydrogenase (G6PD) heterozygous female Safari cats. With this approach, we prove that stochastic differentiation can result in the wide spectrum of discrete outcomes observed in vivo, and that clonal dominance can occur by chance. As the analyses also suggest that the frequency of feline hematopoietic stem cells is only 6 per 10(7) nucleated marrow cells, and that sem cells do not replicate on average more frequently than once every three weeks, these large-animal data challenge clinical strategies for marrow transplantation and gene therapy.

  11. Investigation of septin biology in vivo using zebrafish.

    PubMed

    Willis, A; Mazon-Moya, M; Mostowy, S

    2016-01-01

    The zebrafish (Danio rerio) is an important animal model to study cell biology in vivo. Benefits of the zebrafish include a fully annotated reference genome, an easily manipulable genome (for example, by morpholino oligonucleotide or CRISPR-Cas9), and transparent embryos for noninvasive, real-time microscopy using fluorescent transgenic lines. Zebrafish have orthologues of most human septins, and studies using larvae were used to investigate the role of septins in vertebrate development. The zebrafish larva is also an established model to study the cell biology of infection and has recently been used to visualize septin assembly during bacterial infection in vivo. Here, we describe protocols for the study of septins in zebrafish, with emphasis on techniques used to investigate the role of septins in host defense against bacterial infection. PMID:27473912

  12. In vivo photoacoustic imaging of model of port wine stains.

    PubMed

    Yuan, Kaihua; Yuan, Yi; Gu, Ying; Gao, Jianhua; Xing, Da

    2012-01-01

    Port wine stains are categorized as a benign capillary vascular malformation, which is hard to cure. In this paper, a photoacoustic microscopy system, which integrated a two-dimensional scanning galvanometer, an objective lens and a focused ultrasound transducer, was designed for noninvasive imaging of blood vessels of port wine stains model in vivo. Cock comb was chosen as the port wine stains model in the experiment. The blood vessels in x-y plane and x-z plane were imaged clearly. Experimental results demonstrate that photoacoustic microscopy can image the blood vessels of port wine stains model in vivo with high contrast and high resolution. It has the potential for clinical applications in detecting the blood vessels in port wine stains skin. PMID:22635179

  13. In vivo platforms for analysis of HIV persistence and eradication.

    PubMed

    Garcia, J Victor

    2016-02-01

    HIV persistence in patients undergoing antiretroviral therapy is a major impediment to the cure of HIV/AIDS. The molecular and cellular mechanisms underlying HIV persistence in vivo have not been fully elucidated. This lack of basic knowledge has hindered progress in this area. The in vivo analysis of HIV persistence and the implementation of curative strategies would benefit from animal models that accurately recapitulate key aspects of the human condition. This Review summarizes the contribution that humanized mouse models of HIV infection have made to the field of HIV cure research. Even though these models have been shown to be highly informative in many specific areas, their great potential to serve as excellent platforms for discovery in HIV pathogenesis and treatment has yet to be fully developed.

  14. Dendritic spines: from structure to in vivo function

    PubMed Central

    Rochefort, Nathalie L; Konnerth, Arthur

    2012-01-01

    Dendritic spines arise as small protrusions from the dendritic shaft of various types of neuron and receive inputs from excitatory axons. Ever since dendritic spines were first described in the nineteenth century, questions about their function have spawned many hypotheses. In this review, we introduce understanding of the structural and biochemical properties of dendritic spines with emphasis on components studied with imaging methods. We then explore advances in in vivo imaging methods that are allowing spine activity to be studied in living tissue, from super-resolution techniques to calcium imaging. Finally, we review studies on spine structure and function in vivo. These new results shed light on the development, integration properties and plasticity of spines. PMID:22791026

  15. Fluorescence molecular tomography resolves protease activity in vivo.

    PubMed

    Ntziachristos, Vasilis; Tung, Ching-Hsuan; Bremer, Christoph; Weissleder, Ralph

    2002-07-01

    Systematic efforts are under way to develop novel technologies that would allow molecular sensing in intact organisms in vivo. Using near-infrared fluorescent molecular beacons and inversion techniques that take into account the diffuse nature of photon propagation in tissue, we were able to obtain three-dimensional in vivo images of a protease in orthopic gliomas. We demonstrate that enzyme-activatable fluorochromes can be detected with high positional accuracy in deep tissues, that molecular specificities of different beacons towards enzymes can be resolved and that tomography of beacon activation is linearly related to enzyme concentration. The tomographic imaging method offers a range of new capabilities for studying biological function; for example, identifying molecular-expression patterns by multispectral imaging or continuously monitoring the efficacy of therapeutic drugs.

  16. In vivo imaging of the pharmacodynamics and pharmacokinetics of lithium.

    PubMed

    Kilts, C D

    2000-01-01

    The therapeutic efficacy of lithium for the long-term management of bipolar disorder is well recognized, along with the risk of lithium-induced toxicity. The author describes the current findings of in vivo functional neuroimaging techniques with respect to the pharmacokinetics and pharmacodynamics of lithium and their future potential to elucidate the drug distribution and neural mechanisms that produce its therapeutic effects. Brain Li nuclear magnetic resonance spectroscopy findings have disassociated postdose brain and blood lithium concentrations and suggest a pharmacokinetic basis for lithium response and nonresponse. The application of in vivo synaptic activity and neurochemical imaging is providing new knowledge related to the distributed neural activity associated with lithium response and is contributing to the critical human testing of neuroprotective and signal transduction models of lithium's therapeutic effects.

  17. In vivo confocal imaging: general principles and applications.

    PubMed

    Petroll, W M; Jester, J V; Cavanagh, H D

    1994-01-01

    It is well established that confocal microscopy provides higher resolution images with better rejection of out-of-focus information than conventional light microscopy. The optical sectioning ability of confocal microscopy allows images to be obtained from different depths within a thick tissue specimen, thereby eliminating the need for processing and sectioning procedures. Thus, confocal microscopy has made it possible to view biological tissues under more physiologic conditions than previously possible. The most widespread biological application of confocal microscopy has been in the localization of immunofluorescently labeled proteins in cell culture or within excised blocks of tissue. Because of its noninvasive optical sectioning capability, confocal microscopy is also ideally suited to the study of tissue in intact living animals, although the potential in vivo applications of this paradigm have received less attention. In this paper we trace the development of in vivo confocal microscopy and present examples of current capabilities for both research and clinical use.

  18. In vivo SELEX for Identification of Brain-penetrating Aptamers

    PubMed Central

    Cheng, Congsheng; Chen, Yong Hong; Lennox, Kim A; Behlke, Mark A; Davidson, Beverly L

    2013-01-01

    The physiological barriers of the brain impair drug delivery for treatment of many neurological disorders. One delivery approach that has not been investigated for their ability to penetrate the brain is RNA-based aptamers. These molecules can impart delivery to peripheral tissues and circulating immune cells, where they act as ligand mimics or can be modified to carry payloads. We developed a library of aptamers and an in vivo evolution protocol to determine whether specific aptamers could be identified that would home to the brain after injection into the peripheral vasculature. Unlike biopanning with recombinant bacteriophage libraries, we found that the aptamer library employed here required more than 15 rounds of in vivo selection for convergence to specific sequences. The aptamer species identified through this approach bound to brain capillary endothelia and penetrated into the parenchyma. The methods described may find general utility for targeting various payloads to the brain. PMID:23299833

  19. Nanoparticles that communicate in vivo to amplify tumour targeting

    NASA Astrophysics Data System (ADS)

    von Maltzahn, Geoffrey; Park, Ji-Ho; Lin, Kevin Y.; Singh, Neetu; Schwöppe, Christian; Mesters, Rolf; Berdel, Wolfgang E.; Ruoslahti, Erkki; Sailor, Michael J.; Bhatia, Sangeeta N.

    2011-07-01

    Nanomedicines have enormous potential to improve the precision of cancer therapy, yet our ability to efficiently home these materials to regions of disease in vivo remains very limited. Inspired by the ability of communication to improve targeting in biological systems, such as inflammatory-cell recruitment to sites of disease, we construct systems where synthetic biological and nanotechnological components communicate to amplify disease targeting in vivo. These systems are composed of ‘signalling’ modules (nanoparticles or engineered proteins) that target tumours and then locally activate the coagulation cascade to broadcast tumour location to clot-targeted ‘receiving’ nanoparticles in circulation that carry a diagnostic or therapeutic cargo, thereby amplifying their delivery. We show that communicating nanoparticle systems can be composed of multiple types of signalling and receiving modules, can transmit information through multiple molecular pathways in coagulation, can operate autonomously and can target over 40 times higher doses of chemotherapeutics to tumours than non-communicating controls.

  20. Nanoscale Imaging of Caveolin-1 Membrane Domains In Vivo

    PubMed Central

    Gabor, Kristin A.; Kim, Dahan; Kim, Carol H.; Hess, Samuel T.

    2015-01-01

    Light microscopy enables noninvasive imaging of fluorescent species in biological specimens, but resolution is generally limited by diffraction to ~200–250 nm. Many biological processes occur on smaller length scales, highlighting the importance of techniques that can image below the diffraction limit and provide valuable single-molecule information. In recent years, imaging techniques have been developed which can achieve resolution below the diffraction limit. Utilizing one such technique, fluorescence photoactivation localization microscopy (FPALM), we demonstrated its ability to construct super-resolution images from single molecules in a living zebrafish embryo, expanding the realm of previous super-resolution imaging to a living vertebrate organism. We imaged caveolin-1 in vivo, in living zebrafish embryos. Our results demonstrate the successful image acquisition of super-resolution images in a living vertebrate organism, opening several opportunities to answer more dynamic biological questions in vivo at the previously inaccessible nanoscale. PMID:25646724

  1. In vivo EMG biofeedback in violin and viola pedagogy.

    PubMed

    LeVine, W R; Irvine, J K

    1984-06-01

    In vivo EMG biofeedback was found to be an effective pedagogical tool for removing unwanted left-hand tension in nine violin and viola players. Improvement occurred rapidly and persisted throughout a 5-month follow-up period. Further studies will be necessary to assess the effect of biofeedback independent of placebo effects. The brevity of the method and the magnitude of improvement warrant further investigation. PMID:6509108

  2. In vivo compartmental analysis of leukocytes in mouse lungs.

    PubMed

    Patel, Brijesh V; Tatham, Kate C; Wilson, Michael R; O'Dea, Kieran P; Takata, Masao

    2015-10-01

    The lung has a unique structure consisting of three functionally different compartments (alveolar, interstitial, and vascular) situated in an extreme proximity. Current methods to localize lung leukocytes using bronchoalveolar lavage and/or lung perfusion have significant limitations for determination of location and phenotype of leukocytes. Here we present a novel method using in vivo antibody labeling to enable accurate compartmental localization/quantification and phenotyping of mouse lung leukocytes. Anesthetized C57BL/6 mice received combined in vivo intravenous and intratracheal labeling with fluorophore-conjugated anti-CD45 antibodies, and lung single-cell suspensions were analyzed by flow cytometry. The combined in vivo intravenous and intratracheal CD45 labeling enabled robust separation of the alveolar, interstitial, and vascular compartments of the lung. In naive mice, the alveolar compartment consisted predominantly of resident alveolar macrophages. The interstitial compartment, gated by events negative for both intratracheal and intravenous CD45 staining, showed two conventional dendritic cell populations, as well as a Ly6C(lo) monocyte population. Expression levels of MHCII on these interstitial monocytes were much higher than on the vascular Ly6C(lo) monocyte populations. In mice exposed to acid aspiration-induced lung injury, this protocol also clearly distinguished the three lung compartments showing the dynamic trafficking of neutrophils and exudative monocytes across the lung compartments during inflammation and resolution. This simple in vivo dual-labeling technique substantially increases the accuracy and depth of lung flow cytometric analysis, facilitates a more comprehensive examination of lung leukocyte pools, and enables the investigation of previously poorly defined "interstitial" leukocyte populations during models of inflammatory lung diseases.

  3. Biosynthesis of rat enamel matrix components in vivo

    SciTech Connect

    Sasaki, S.; Shimokawa, H.; Tanaka, K.

    1982-12-01

    The biosynthesis of enamel matrix components of developing rat incisors was investigated by measuring the incorporation of /sup 3/H-proline, /sup 32/P-phosphate, and /sup 35/S-sulfate in vivo. /sup 3/H- and /sup 32/P-radioactivity was found in what seemed to be a prototype of enamel proteins. Subsequent shifts in other protein and peptide fractions were observed. /sup 35/S was also incorporated into components other than the above-mentioned proteins.

  4. In vivo protein crystallization opens new routes in structural biology.

    PubMed

    Koopmann, Rudolf; Cupelli, Karolina; Redecke, Lars; Nass, Karol; Deponte, Daniel P; White, Thomas A; Stellato, Francesco; Rehders, Dirk; Liang, Mengning; Andreasson, Jakob; Aquila, Andrew; Bajt, Sasa; Barthelmess, Miriam; Barty, Anton; Bogan, Michael J; Bostedt, Christoph; Boutet, Sébastien; Bozek, John D; Caleman, Carl; Coppola, Nicola; Davidsson, Jan; Doak, R Bruce; Ekeberg, Tomas; Epp, Sascha W; Erk, Benjamin; Fleckenstein, Holger; Foucar, Lutz; Graafsma, Heinz; Gumprecht, Lars; Hajdu, Janos; Hampton, Christina Y; Hartmann, Andreas; Hartmann, Robert; Hauser, Günter; Hirsemann, Helmut; Holl, Peter; Hunter, Mark S; Kassemeyer, Stephan; Kirian, Richard A; Lomb, Lukas; Maia, Filipe R N C; Kimmel, Nils; Martin, Andrew V; Messerschmidt, Marc; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Schlichting, Ilme; Schulz, Joachim; Seibert, M Marvin; Shoeman, Robert L; Sierra, Raymond G; Soltau, Heike; Stern, Stephan; Strüder, Lothar; Timneanu, Nicusor; Ullrich, Joachim; Wang, Xiaoyu; Weidenspointner, Georg; Weierstall, Uwe; Williams, Garth J; Wunderer, Cornelia B; Fromme, Petra; Spence, John C H; Stehle, Thilo; Chapman, Henry N; Betzel, Christian; Duszenko, Michael

    2012-03-01

    Protein crystallization in cells has been observed several times in nature. However, owing to their small size these crystals have not yet been used for X-ray crystallographic analysis. We prepared nano-sized in vivo-grown crystals of Trypanosoma brucei enzymes and applied the emerging method of free-electron laser-based serial femtosecond crystallography to record interpretable diffraction data. This combined approach will open new opportunities in structural systems biology.

  5. In vivo mouse imaging using frequency domain optoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Kellnberger, Stephan; Deliolanis, Nikolaos C.; Queirós, Daniel; Sergiadis, George; Ntziachristos, Vasilis

    2013-06-01

    Frequency domain optoacoustics relates to stimulation of optoacoustic signals using intensity modulated continuous wave light instead of pulsed laser light employed in time domain optoacoustic imaging. We present a method to generate frequency domain tomographic images of optical absorbers and cross sectional in-vivo mouse images, showing the changes of optical absorption before and after injection of indocyanine green (ICG). OCIS codes: 170.6960, 170.3880, 170.5220

  6. Are rare-earth nanoparticles suitable for in vivo applications?

    PubMed

    Liu, Chunyan; Hou, Yi; Gao, Mingyuan

    2014-10-29

    Rare earth (RE) nanoparticles have attracted considerable attention due to their unique optical and magnetic properties associated with f-electrons. The recent accomplishments in RE nanoparticle synthesis have aroused great interest of scientists to further explore their biomedical applications. This Research News summarizes recent achievements in controlled synthesis of magnetic and luminescent RE nanoparticles, surface modification, and toxicity studies of RE nanomaterials, and highlights state-of-the-art in in vivo applications of RE nanoparticles.

  7. In vivo multiphoton imaging of obstructive cholestasis in mice

    NASA Astrophysics Data System (ADS)

    Li, Feng-Chieh; Lee, Yu Yang; Chiou, Ling-Ling; Lee, Hsuan-Shu; Dong, Chen-Yuan

    2010-02-01

    Combining multiphoton microscopy with a newly designed hepatic imaging window, we acquired in vivo images of mice obstructive cholestasis. We observed that in mice with bile duct ligation, bile canaliculi failed to appear during the whole observation period over 100 minutes following carboxyfluorescein diacetate injection, whereas the fluorescence was retained much longer within sinusoids. Furthermore, the fluorescence intensities in sinusoids were persistently higher than in hepatocytes during the course.

  8. Directed evolution of artificial metalloenzymes for in vivo metathesis

    NASA Astrophysics Data System (ADS)

    Jeschek, Markus; Reuter, Raphael; Heinisch, Tillmann; Trindler, Christian; Klehr, Juliane; Panke, Sven; Ward, Thomas R.

    2016-09-01

    The field of biocatalysis has advanced from harnessing natural enzymes to using directed evolution to obtain new biocatalysts with tailor-made functions. Several tools have recently been developed to expand the natural enzymatic repertoire with abiotic reactions. For example, artificial metalloenzymes, which combine the versatile reaction scope of transition metals with the beneficial catalytic features of enzymes, offer an attractive means to engineer new reactions. Three complementary strategies exist: repurposing natural metalloenzymes for abiotic transformations; in silico metalloenzyme (re-)design; and incorporation of abiotic cofactors into proteins. The third strategy offers the opportunity to design a wide variety of artificial metalloenzymes for non-natural reactions. However, many metal cofactors are inhibited by cellular components and therefore require purification of the scaffold protein. This limits the throughput of genetic optimization schemes applied to artificial metalloenzymes and their applicability in vivo to expand natural metabolism. Here we report the compartmentalization and in vivo evolution of an artificial metalloenzyme for olefin metathesis, which represents an archetypal organometallic reaction without equivalent in nature. Building on previous work on an artificial metallohydrolase, we exploit the periplasm of Escherichia coli as a reaction compartment for the ‘metathase’ because it offers an auspicious environment for artificial metalloenzymes, mainly owing to low concentrations of inhibitors such as glutathione, which has recently been identified as a major inhibitor. This strategy facilitated the assembly of a functional metathase in vivo and its directed evolution with substantially increased throughput compared to conventional approaches that rely on purified protein variants. The evolved metathase compares favourably with commercial catalysts, shows activity for different metathesis substrates and can be further evolved in

  9. In vivo brain microdialysis: advances in neuropsychopharmacology and drug discovery

    PubMed Central

    Darvesh, Altaf S.; Carroll, Richard T.; Geldenhuys, Werner J.; Gudelsky, Gary A.; Klein, Jochen; Meshul, Charles K.; Van der Schyf, Cornelis J.

    2010-01-01

    Introduction Microdialysis is an important in vivo sampling technique, useful in the assay of extracellular tissue fluid. The technique has both pre-clinical and clinical applications but is most widely used in neuroscience. The in vivo microdialysis technique allows measurement of neurotransmitters such as acetycholine (ACh), the biogenic amines including dopamine (DA), norepinephrine (NE) and serotonin (5-HT), amino acids such as glutamate (Glu) and gamma aminobutyric acid (GABA), as well as the metabolites of the aforementioned neurotransmitters, and neuropeptides in neuronal extracellular fluid in discrete brain regions of laboratory animals such as rodents and non-human primates. Areas covered In this review we present a brief overview of the principles and procedures related to in vivo microdialysis and detail the use of this technique in the pre-clinical measurement of drugs designed to be used in the treatment of chemical addiction, neurodegenerative diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD) and as well as psychiatric disorders such as attention-deficit/hyperactivity disorder (ADHD) and schizophrenia. This review offers insight into the tremendous utility and versatility of this technique in pursuing neuropharmacological investigations as well its significant potential in rational drug discovery. Expert opinion In vivo microdialysis is an extremely versatile technique, routinely used in the neuropharmacological investigation of drugs used for the treatment of neurological disorders. This technique has been a boon in the elucidation of the neurochemical profile and mechanism of action of several classes of drugs especially their effects on neurotransmitter systems. The exploitation and development of this technique for drug discovery in the near future will enable investigational new drug candidates to be rapidly moved into the clinical trial stages and to market thus providing new successful therapies for neurological diseases

  10. Transcutaneous Raman Spectroscopy of Murine Bone In Vivo

    PubMed Central

    Schulmerich, Matthew V.; Cole, Jacqueline H.; Kreider, Jaclynn M.; Esmonde-White, Francis; Dooley, Kathryn A.; Goldstein, Steven A.; Morris, Michael D.

    2009-01-01

    Raman spectroscopy can provide valuable information about bone tissue composition in studies of bone development, biomechanics, and health. In order to study the Raman spectra of bone in vivo, instrumentation that enhances the recovery of subsurface spectra must be developed and validated. Five fiber-optic probe configurations were considered for transcutaneous bone Raman spectroscopy of small animals. Measurements were obtained from the tibia of sacrificed mice, and the bone Raman signal was recovered for each probe configuration. The configuration with the optimal combination of bone signal intensity, signal variance, and power distribution was then evaluated under in vivo conditions. Multiple in vivo transcutaneous measurements were obtained from the left tibia of 32 anesthetized mice. After collecting the transcutaneous Raman signal, exposed bone measurements were collected and used as a validation reference. Multivariate analysis was used to recover bone spectra from transcutaneous measurements. To assess the validity of the transcutaneous bone measurements cross-correlations were calculated between standardized spectra from the recovered bone signal and the exposed bone measurements. Additionally, the carbonate-to-phosphate height ratios of the recovered bone signals were compared to the reference exposed bone measurements. The mean cross-correlation coefficient between the recovered and exposed measurements was 0.96, and the carbonate-to-phosphate ratios did not differ significantly between the two sets of spectra (p > 0.05). During these first systematic in vivo Raman measurements, we discovered that probe alignment and animal coat color influenced the results and thus should be considered in future probe and study designs. Nevertheless, our noninvasive Raman spectroscopic probe accurately assessed bone tissue composition through the skin in live mice. PMID:19281644

  11. Determination of the in vivo degradation mechanism of PEGDA hydrogels.

    PubMed

    Browning, M B; Cereceres, S N; Luong, P T; Cosgriff-Hernandez, E M

    2014-12-01

    Poly(ethylene glycol) (PEG) hydrogels are one of the most extensively utilized biomaterials systems due to their established biocompatibility and highly tunable properties. It is widely acknowledged that traditional acrylate-derivatized PEG (PEGDA) hydrogels are susceptible to slow degradation in vivo and are therefore unsuitable for long-term implantable applications. However, there is speculation whether the observed degradation is due to hydrolysis of endgroup acrylate esters or oxidation of the ether backbone, both of which are possible in the foreign body response to implanted devices. PEG diacrylamide (PEGDAA) is a polyether-based hydrogel system with similar properties to PEGDA but with amide linkages in place of the acrylate esters. This provides a hydrolytically-stable control that can be used to isolate the relative contributions of hydrolysis and oxidation to the in vivo degradation of PEGDA. Here we show that PEGDAA hydrogels remained stable over 12 weeks of subcutaneous implantation in a rat model while PEGDA hydrogels underwent significant degradation as indicated by both increased swelling ratio and decreased modulus. As PEGDA and PEGDAA have similar susceptibility to oxidation, these results demonstrate for the first time that the primary in vivo degradation mechanism of PEGDA is hydrolysis of the endgroup acrylate esters. Additionally, the maintenance of PEGDAA hydrogel properties in vivo indicates their suitability for long-term implants. These studies serve to elucidate key information about a widely used biomaterial system to allow for better implantable device design and to provide a biostable replacement option for PEGDA in applications that require long-term stability.

  12. Advances in fiber optic sensors for in-vivo monitoring

    NASA Astrophysics Data System (ADS)

    Baldini, Francesco; Mignani, Anna G.

    1995-09-01

    Biomedical fiber-optic sensors are attractive for the measurement of both physical and chemical parameters as well as for spectral measurements directly performed on the patient. An overview of fiber-optic sensors for in vivo monitoring is given, with particular attention to the advantages that these sensors are able to offer in different fields of application such as cardiovascular and intensive care, angiology, gastroenterology, ophthalmology, oncology, neurology, dermatology, and dentistry.

  13. Lens-assisted in vivo desensitization to heights.

    PubMed

    Schneider, J W

    1982-12-01

    Optical lenses that alter perceived depth may be usefully applied in the treatment of acrophobia. The present case report describes reverse viewing through binoculars to magnify apparent height during in vivo desensitization. The technique enables effective treatment from low actual heights, allows close control over exposure durations, and affords the opportunity to extend desensitization to apparent heights considerably greater than those ordinarily available for practice.

  14. Connecting tubule glomerular feedback antagonizes tubuloglomerular feedback in vivo.

    PubMed

    Wang, H; Garvin, J L; D'Ambrosio, M A; Ren, Y; Carretero, O A

    2010-12-01

    In vitro experiments showed that the connecting tubule (CNT) sends a signal that dilates the afferent arteriole (Af-Art) when Na(+) reabsorption in the CNT lumen increases. We call this process CNT glomerular feedback (CTGF) to differentiate it from tubuloglomerular feedback (TGF), which is a cross talk between the macula densa (MD) and the Af-Art. In TGF, the MD signals the Af-Art to constrict when NaCl transport by the MD is enhanced by increased luminal NaCl. CTGF is mediated by CNT Na(+) transport via epithelial Na(+) channels (ENaC). However, we do not know whether CTGF occurs in vivo or whether it opposes the increase in Af-Art resistance caused by TGF. We hypothesized that CTGF occurs in vivo and opposes TGF. To test our hypothesis, we conducted in vivo micropuncture of individual rat nephrons, measuring stop-flow pressure (P(SF)) as an index of glomerular filtration pressure. To test whether activation of CTGF opposes TGF, we used benzamil to block CNT Na(+) transport and thus CTGF. CTGF inhibition with the ENaC blocker benzamil (1 μM) potentiated the decrease in P(SF) at 40 and 80 nl/min. Next, we tested whether we could augment CTGF by inhibiting NaCl reabsorption in the distal convoluted tubule with hydrochlorothiazide (HCTZ, 1 mM) to enhance NaCl delivery to the CNT. In the presence of HCTZ, benzamil potentiated the decrease in P(SF) at 20, 40, and 80 nl/min. We concluded that in vivo CTGF occurs and opposes the vasoconstrictor effect of TGF. PMID:20826574

  15. RNA nanotechnology for computer design and in vivo computation.

    PubMed

    Qiu, Meikang; Khisamutdinov, Emil; Zhao, Zhengyi; Pan, Cheryl; Choi, Jeong-Woo; Leontis, Neocles B; Guo, Peixuan

    2013-10-13

    Molecular-scale computing has been explored since 1989 owing to the foreseeable limitation of Moore's law for silicon-based computation devices. With the potential of massive parallelism, low energy consumption and capability of working in vivo, molecular-scale computing promises a new computational paradigm. Inspired by the concepts from the electronic computer, DNA computing has realized basic Boolean functions and has progressed into multi-layered circuits. Recently, RNA nanotechnology has emerged as an alternative approach. Owing to the newly discovered thermodynamic stability of a special RNA motif (Shu et al. 2011 Nat. Nanotechnol. 6, 658-667 (doi:10.1038/nnano.2011.105)), RNA nanoparticles are emerging as another promising medium for nanodevice and nanomedicine as well as molecular-scale computing. Like DNA, RNA sequences can be designed to form desired secondary structures in a straightforward manner, but RNA is structurally more versatile and more thermodynamically stable owing to its non-canonical base-pairing, tertiary interactions and base-stacking property. A 90-nucleotide RNA can exhibit 4⁹⁰ nanostructures, and its loops and tertiary architecture can serve as a mounting dovetail that eliminates the need for external linking dowels. Its enzymatic and fluorogenic activity creates diversity in computational design. Varieties of small RNA can work cooperatively, synergistically or antagonistically to carry out computational logic circuits. The riboswitch and enzymatic ribozyme activities and its special in vivo attributes offer a great potential for in vivo computation. Unique features in transcription, termination, self-assembly, self-processing and acid resistance enable in vivo production of RNA nanoparticles that harbour various regulators for intracellular manipulation. With all these advantages, RNA computation is promising, but it is still in its infancy. Many challenges still exist. Collaborations between RNA nanotechnologists and computer

  16. In vivo real-time volumetric synthetic aperture ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Bouzari, Hamed; Rasmussen, Morten F.; Brandt, Andreas H.; Stuart, Matthias B.; Nikolov, Svetoslav; Jensen, Jørgen A.

    2015-03-01

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

  17. Myelin water fraction in human cervical spinal cord in vivo.

    PubMed

    Wu, Yijing; Alexander, Andrew L; Fleming, John O; Duncan, Ian D; Field, Aaron S

    2006-01-01

    The noninvasive discrimination of myelin disease from axonal loss and other pathologic confounds remains an unsolved problem in multiple sclerosis but may be possible through magnetic resonance quantitation of the intramyelinic water compartment. Technical challenges have limited the study of this approach in the spinal cord, a common site of involvement in multiple sclerosis. This technical note reports the test-retest reproducibility of a short T2-based estimate of myelin content in human spinal cord in vivo.

  18. Grueneisen relaxation photoacoustic microscopy in vivo (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Shi, Junhui; Hai, Pengfei; Zhou, Yong; Wang, Lihong V.

    2016-03-01

    Optical-resolution photoacoustic microscopy (OR-PAM) can achieve submicron lateral resolution by tightly focusing the excitation light, while the axial resolution is still limited by the frequency bandwidth of the ultrasonic transducer. The Grueneisen relaxation effect, in which the Grueneisen parameter changes within the thermal relaxation time following a laser impulse heating, can provide excellent axial resolution due to its optical sectioning property. Based on this effect, Grueneisen relaxation photoacoustic microscopy (GR-PAM) was developed and demonstrated ex vivo. Here, we present for the first time in vivo imaging of mouse brains with improved axial resolution based on GR-PAM. An intensity-modulated continuous-wave (CW) 532 nm laser thermally heated the in-focus absorber. Another 532 nm pulsed laser, which is aligned confocally with the CW laser, generated the photoacoustic (PA) signal from the absorber. The difference between the amplitudes of the photoacoustic signals with and without heating was used for image reconstruction. The achieved axial resolution is ~12.5 µm, which is fivefold better than the acoustically determined value for a 20 MHz-bandwidth ultrasound transducer. The system was demonstrated by imaging a blood-filled tube ex vivo and blood vessels of mouse brains in vivo. The blood-filled tube diameter obtained from the PA image by GR-PAM is 105 µm, which is much closer to its actual diameter (100 µm) than the value from conventional OR-PAM (160 µm). This axial resolution improvement was further validated in imaging mouse brains in vivo, and yielded significantly narrower axial profiles of the vessels. This in vivo demonstration of imaging by GR-PAM might inspire more applications in PA biomedical imaging and sensing.

  19. Studying tumor metastasis by in vivo imaging and flow cytometer

    NASA Astrophysics Data System (ADS)

    Wei, Xunbin; Guo, Jin; Liu, Guangda; Li, Yan; Chen, Yun; Zhang, Li; Tan, Yuan; Chen, Tong; Gu, Zhenqin; Wang, Chen

    2009-02-01

    Liver cancer is one of the most common malignancies in the world, with approximately 1,000,000 cases reported every year. This ranges from 15,000 cases in the United States to more than a 250,000 in China. About 80% of people with primary liver cancer are male. Although two-thirds of people have advanced liver disease when they seek medical help, one third of the patients have cancer that has not progressed beyond the liver. Primary liver cancer (hepatocellular carcinoma, or HCC) is associated with liver cirrhosis 60-80% of the time. HCC may metastasize to the lung, bones, kidney, and many other organs. Surgical resection, liver transplantation, chemotherapy and radiation therapy are the foundation of current HCC therapies. However the outcomes are poor-the survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed to selectively target to unique characteristics of HCC cell growth and metastasis. We have developed the "in vivo microscopy" to study the mechanisms that govern liver tumor cell spread through the microenvironment in vivo in real-time confocal near-infrared fluorescence imaging. A recently developed "in vivo flow cytometer" and optical imaging are used to assess liver tumor cell spreading and the circulation kinetics of liver tumor cells. A real-time quantitative monitoring of circulating liver tumor cells by the in vivo flow cytometer will be useful to assess the effectiveness of the potential therapeutic interventions.

  20. NIR fluorescent ytterbium compound for in vivo fluorescence molecular imaging.

    PubMed

    Aita, Kazuki; Temma, Takashi; Kuge, Yuji; Seki, Koh-ichi; Saji, Hideo

    2010-01-01

    We have developed a new NIR fluorescent probe based on an ytterbium(III) (E)-1-(pyridin-2-yl-diazenyl)naphthalen-2-ol (PAN) complex. This probe emits near-infrared luminescence derived from the Yb ion through excitation of the PAN moiety with visible light (lambda(ex)= 530 nm, lambda(em)= 975 nm). The results support the possible utility of the probe for in vivo fluorescence molecular imaging.

  1. Amphiphilic vinyl polymers effectively prolong liposome circulation time in vivo.

    PubMed

    Torchilin, V P; Shtilman, M I; Trubetskoy, V S; Whiteman, K; Milstein, A M

    1994-10-12

    Newly synthesized amphiphilic polyacrylamide and poly(vinyl pyrrolidone), single terminus-modified with long-chain fatty acyl groups, are able to incorporate into the liposomal membrane, and similar to poly(ethylene glycol) prolong liposome circulation in vivo and decrease liposome accumulation in the liver. Protective efficacy of modified polymers increases with the increase in the length of acyl moiety and decreases for higher molecular weight polymers. The data on amphiphilic polymer-modified liposome biodistribution are presented.

  2. Measuring In Vivo Free Radical Production by the Outer Retina

    PubMed Central

    Berkowitz, Bruce A.; Bredell, Bryce X.; Davis, Christopher; Samardzija, Marijana; Grimm, Christian; Roberts, Robin

    2015-01-01

    Purpose Excessive and continuously produced free radicals in the outer retina are implicated in retinal aging and the pathogenesis of sight-threatening retinopathies, yet measuring outer retinal oxidative stress in vivo remains a challenge. Here, we test the hypothesis that continuously produced paramagnetic free radicals from the outer retina can be measured in vivo using high-resolution (22-μm axial resolution) 1/T1magnetic resonance imaging (MRI) without and with a confirmatory quench (quench-assisted MRI). Methods Low-dose sodium iodate–treated and diabetic C57Bl6/J mice (and their controls), and rod-dominated (129S6) or cone-only R91W;Nrl−/− mice were studied. In dark-adapted groups, 1/T1 was mapped transretinally in vivo without or with (1) the antioxidant combination of methylene blue (MB) and α-lipoic acid (LPA), or (2) light exposure; in subgroups, retinal superoxide production was measured ex vivo (lucigenin). Results In the sodium iodate model, retinal superoxide production and outer retina-specific 1/T1 values were both significantly greater than normal and corrected to baseline with MB+LPA therapy. Nondiabetic mice at two ages and 1.2-month diabetic mice (before the appearance of oxidative stress) had similar transretinal 1/T1 profiles. By 2.3 months of diabetes, only outer retinal 1/T1 values were significantly greater than normal and were corrected to baseline with MB+LPA therapy. In mice with healthy photoreceptors, a light quench caused 1/T1 of rods, but not cones, to significantly decrease from their values in the dark. Conclusions Quench-assisted MRI is a feasible method for noninvasively measuring normal and pathologic production of free radicals in photoreceptors/RPE in vivo. PMID:26670830

  3. Interferon induces natural killer cell blastogenesis in vivo

    NASA Technical Reports Server (NTRS)

    Biron, C. A.; Sonnenfeld, G.; Welsh, R. M.

    1984-01-01

    Interferon (IFN), types beta and gamma, and IFN inducers polyinosinic-polycytidylic acid and lymphocytic choriomeningitis virus, all stimulated the generation of blast-natural killer (NK) cells in mouse spleens, Blast-NK cells were characterized on the basis of size, 3H-thymidine uptake, and NK cell markers These data indicate that in addition to augmenting NK cell-mediated lysis, IFN may regulate NK cell proliferation in vivo.

  4. In vivo protein crystallization opens new routes in structural biology.

    PubMed

    Koopmann, Rudolf; Cupelli, Karolina; Redecke, Lars; Nass, Karol; Deponte, Daniel P; White, Thomas A; Stellato, Francesco; Rehders, Dirk; Liang, Mengning; Andreasson, Jakob; Aquila, Andrew; Bajt, Sasa; Barthelmess, Miriam; Barty, Anton; Bogan, Michael J; Bostedt, Christoph; Boutet, Sébastien; Bozek, John D; Caleman, Carl; Coppola, Nicola; Davidsson, Jan; Doak, R Bruce; Ekeberg, Tomas; Epp, Sascha W; Erk, Benjamin; Fleckenstein, Holger; Foucar, Lutz; Graafsma, Heinz; Gumprecht, Lars; Hajdu, Janos; Hampton, Christina Y; Hartmann, Andreas; Hartmann, Robert; Hauser, Günter; Hirsemann, Helmut; Holl, Peter; Hunter, Mark S; Kassemeyer, Stephan; Kirian, Richard A; Lomb, Lukas; Maia, Filipe R N C; Kimmel, Nils; Martin, Andrew V; Messerschmidt, Marc; Reich, Christian; Rolles, Daniel; Rudek, Benedikt; Rudenko, Artem; Schlichting, Ilme; Schulz, Joachim; Seibert, M Marvin; Shoeman, Robert L; Sierra, Raymond G; Soltau, Heike; Stern, Stephan; Strüder, Lothar; Timneanu, Nicusor; Ullrich, Joachim; Wang, Xiaoyu; Weidenspointner, Georg; Weierstall, Uwe; Williams, Garth J; Wunderer, Cornelia B; Fromme, Petra; Spence, John C H; Stehle, Thilo; Chapman, Henry N; Betzel, Christian; Duszenko, Michael

    2012-03-01

    Protein crystallization in cells has been observed several times in nature. However, owing to their small size these crystals have not yet been used for X-ray crystallographic analysis. We prepared nano-sized in vivo-grown crystals of Trypanosoma brucei enzymes and applied the emerging method of free-electron laser-based serial femtosecond crystallography to record interpretable diffraction data. This combined approach will open new opportunities in structural systems biology. PMID:22286384

  5. A profile of silicosis cases who died.

    PubMed

    Phoon, W H

    1982-01-01

    Silicosis cases which had been notified by doctors and confirmed after investigations were followed up by the Industrial Health Division. Up to August 1981, a total of 313 persons were confirmed as having the disease. Of these, 59 had died. The majority of these 59 persons had had their silica exposure in the granite quarries. 13 had been exposed to "rubber powder" which contained a high percentage of free silica. 52 of those who died were male, and their average age at death was 60.87 years. This did not appear to be significantly shorter than their life expectancy of 65.1 years. But the average age of death for the 7 women was 58.86 years, which was much shorter than their life expectancy of 70 years. Many of the men died from causes unrelated to silicosis. But 6 of the 7 women had progressive massive fibrosis (PMF) and they apparently died of the disease or complications arising from it.

  6. The Onion and "When Legends Die."

    ERIC Educational Resources Information Center

    Bell, Loren C.

    1984-01-01

    Describes the eight layers in Thomas Black Bull's ("When the Legends Die") journey to spiritual rebirth and stresses that students can easily identify these layers and can thereby achieve a clearer understanding of the relationship between structure and meaning in fiction. (CRH)

  7. Weltall im Wandel. Die neue Astronomie.

    NASA Astrophysics Data System (ADS)

    Elsässer, H.

    Contents: Alte und neue Astronomie. Die Sterne des Milchstraßensystems. Sternentstehung und interstellare Materie. Unser Sonnensystem und seine Geschichte. Interplanetarer Staub. Vom Sterben der Sterne. Arbeitsmittel der optischen Astronomie. Ein neues Zentrum astronomischer Forschung. Galaxien. Ursprung und Entwicklung des Weltalls.

  8. Expectation and Variation with a Virtual Die

    ERIC Educational Resources Information Center

    Watson, Jane; English, Lyn

    2015-01-01

    By the time students reach the middle years they have experienced many chance activities based on dice. Common among these are rolling one die to explore the relationship of frequency and theoretical probability, and rolling two dice and summing the outcomes to consider their probabilities. Although dice may be considered overused by some, the…

  9. The Academic Study of Death and Dying.

    ERIC Educational Resources Information Center

    Amend, Edward W.

    The current study of death and dying is an example of constant change and development in academic disciplines. While the discussion of death in time of crisis is hard, if not impossible, youthful undergraduates find this topic to be of considerable interest. For them, a course can be organized effectively as a small and intimate seminar, which…

  10. Mold Die Making. 439-322/324.

    ERIC Educational Resources Information Center

    Yunke, P.; And Others

    Each unit in this curriculum guide on mold die making contains an introduction, objectives, materials required, lessons, space for notes, figures, and diagrams. There are 10 units in this guide: (1) introduction to Electrical Discharge Machining (EDM); (2) EDM principles; (3) the single pulse; (4) EDM safety; (5) electrode material; (6) electrode…

  11. Continuing Education on Dying and Death.

    ERIC Educational Resources Information Center

    Chodil, Judith J.; Dulaney, Peggy E.

    1984-01-01

    "Dying and Death in Critical Care Practice" was a one-day continuing education offering designed for registered nurses who practiced in settings such as emergency rooms, intensive care units, coronary care units, and operating rooms. The workshop was part of a continuing education curriculum in critical care nursing. (SSH)

  12. Care of the Dying: A Swedish Perspective

    ERIC Educational Resources Information Center

    Feigenberg, Loma; Fulton, Robert

    1977-01-01

    This article illustrates various aspects of terminal care, and shows that rules and norms for such care do not exist today. The authors advocate the formulation of an aim for humane treatment of dying patients, and its application in a manner appropriate to Swedish medical concepts and Swedish conditions. (Author)

  13. Asymmetric Die Grows Purer Silicon Ribbon

    NASA Technical Reports Server (NTRS)

    Kalejs, J. P.; Chalmers, B.; Surek, T.

    1983-01-01

    Concentration of carbide impurities in silicon ribbon is reduced by growing crystalline ribbon with die one wall higher than other. Height difference controls shape of meniscus at liquid/crystal interface and concentrates silicon carbide impurity near one of broad faces. Opposite face is left with above-average purity. Significantly improves efficiency of solar cells made from ribbon.

  14. Ceramic for Silicon-Shaping Dies

    NASA Technical Reports Server (NTRS)

    Sekercioglu, I.; Wills, R. R.

    1982-01-01

    Silicon beryllium oxynitride (SiBON) is a promising candidate material for manufacture of shaping dies used in fabricating ribbons or sheets of silicon. It is extremely stable, resists thermal shock, and has excellent resistance to molten silicon. SiBON is a solid solution of beryllium silicate in beta-silicon nitride.

  15. Flexible, Ultra-Thin, Embedded Die Packaging

    NASA Astrophysics Data System (ADS)

    McPherson, Ryan J.

    As thin, flexible electronics solutions become more robust, their integration into everyday life becomes more likely. With possible applications in wearable electronics, biomedical sensors, or 'peel and stick' sensors, the reliability of these ultra-thin packages becomes paramount. Likewise, the density achievable with stacked packages benefits greatly from thinner die stacks. To this end, techniques previously developed have demonstrated packages with die thinned to approximately 20mum. Covered in this work are methods for thinning and packaging silicon die, as well as information on common materials used in these processes. The author's contribution is a fabrication process for embedding ultra-thin (approximately 10mum) silicon die in polyimide substrates. This method is fully illustrated in Chapter 3 and enumerated in the Appendix as a quick reference. Additionally, thermal cycle testing of passive daisy chain assemblies has shown promising reliability data. Packages were mounted in three alignments: flat, concave, and convex, and placed into thermal shock testing. Finally, the author discusses possible applications for this fabrication process, including the fabrication of multi-chip-modules.

  16. Stamping Die Making. 439-318/320.

    ERIC Educational Resources Information Center

    Yunke, P.; And Others

    Each unit in this curriculum guide on stamping die making contains an introduction, objectives, materials required, lessons, space for notes, figures, and diagrams. There are 29 units in this guide, dealing with the following topics: EZ-MILL programming; EZ-MILL BATT; print of punch and EZ-MILL part programming; download to Computer Numerical…

  17. A Guide to Studying Human Hair Follicle Cycling In Vivo.

    PubMed

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan; Kim, Moonkyu; Paus, Ralf; Plikus, Maksim V

    2016-01-01

    Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. Although available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. In this article, we present such a guide, which uses objective, well-defined, and reproducible criteria, and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in suboptimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field. PMID:26763421

  18. Novel in vivo techniques to visualize kidney anatomy and function.

    PubMed

    Peti-Peterdi, János; Kidokoro, Kengo; Riquier-Brison, Anne

    2015-07-01

    Intravital imaging using multiphoton microscopy (MPM) has become an increasingly popular and widely used experimental technique in kidney research over the past few years. MPM allows deep optical sectioning of the intact, living kidney tissue with submicron resolution, which is unparalleled among intravital imaging approaches. MPM has solved a long-standing critical technical barrier in renal research to study several complex and inaccessible cell types and anatomical structures in vivo in their native environment. Comprehensive and quantitative kidney structure and function MPM studies helped our better understanding of the cellular and molecular mechanisms of the healthy and diseased kidney. This review summarizes recent in vivo MPM studies with a focus on the glomerulus and the filtration barrier, although select, glomerulus-related renal vascular and tubular functions are also mentioned. The latest applications of serial MPM of the same glomerulus in vivo, in the intact kidney over several days, during the progression of glomerular disease are discussed. This visual approach, in combination with genetically encoded fluorescent markers of cell lineage, has helped track the fate and function (e.g., cell calcium changes) of single podocytes during the development of glomerular pathologies, and provided visual proof for the highly dynamic, rather than static, nature of the glomerular environment. Future intravital imaging applications have the promise to further push the limits of optical microscopy, and to advance our understanding of the mechanisms of kidney injury. Also, MPM will help to study new mechanisms of tissue repair and regeneration, a cutting-edge area of kidney research.

  19. In vivo potential of recombinant granulysin against human tumors

    PubMed Central

    Al-Wasaby, Sameer; de Miguel, Diego; Aporta, Adriana; Naval, Javier; Conde, Blanca; Martínez-Lostao, Luis; Anel, Alberto

    2015-01-01

    9 kDa granulysin is a protein present in the granules of human CTL and NK cells, with cytolytic activity against microbes and tumors. Previous work from our group demonstrated that this granulysin isoform induced apoptosis in vitro on hematological tumor cells and on primary tumor cells from B-CLL patients. In the present work, recombinant 9 kDa granulysin was used as an anti-tumoral agent to study its in vivo effect on tumor development in athymic “nude” mice models bearing human breast adenocarcinoma MDA-MB-231 or multiple myeloma NCI-H929–derived xenografts. Granulysin prevented the in vivo development of detectable MDA-MB-231-derived tumors. In addition, recombinant granulysin was able to completely eradicate NCI-H929-derived tumors. All granulysin-treated tumors exhibited signs of apoptosis induction and an increased NK cell infiltration inside the tumor tissue comparing to control ones. Moreover, no in vivo deleterious effects of the recombinant 9 kDa granulysin doses used in this study were observed on the skin or on the internal organs of the animals. In conclusion, granulysin was able to inhibit the progression of MDA-MB-231-derived xenografts and also to eradicate multiple myeloma NCI-H929-derived xenografts. This work opens the door to the initiation of preclinical and possibly clinical studies for the use of 9 kDa granulysin as a new anti-tumoral treatment. PMID:26405603

  20. Factor XIa induced activation of the intrinsic cascade in vivo.

    PubMed

    ten Cate, H; Biemond, B J; Levi, M; Wuillemin, W A; Bauer, K A; Barzegar, S; Buller, H R; Hack, C E; ten Cate, J W; Rosenberg, R D

    1996-03-01

    Coagulation factor XI is a glycoprotein of the contact factor system. Its deficiency is associated with a highly variable bleeding tendency, thus a role in relation to hemostasis appears to exist. However, the importance of factor XI for stimulating intrinsic coagulation in vivo has not yet been determined. To study the procoagulant effects of human factor XIa in vivo, we infused the purified enzyme into normal chimpanzees (100 micrograms) in the absence or presence of the thrombin inhibitor rec-hirudin (1.0 mg/kg loading dose plus 0.3 mg/kg body wt continuous infusion). Factor XIa elicited an immediate activation of factors IX, X, and prothrombin, as measured by their respective activation fragments. However, whereas the activation of factors IX and X was immediate and shortlasting, (peak increments of 6- and 1.4-fold of baseline at 5 minutes after injection), the conversion of prothrombin gradually increased, reaching a summit of 6-fold baseline values after 60 min, and remaining elevated during the course of the experiments. Thrombin-antithrombin complexes also remained elevated during the study period. In the presence of hirudin, the initial activation of factors IX, X, and prothrombin was unchanged, however the further increment in prothrombin fragment F1 + 2 was markedly inhibited. These results demonstrate that factor XIa is a potential agonist of the intrinsic cascade in vivo, which activity is enhanced in the presence of thrombin.

  1. Diploic venous anatomy studied in-vivo by MRI.

    PubMed

    Jivraj, Khalil; Bhargava, Ravi; Aronyk, Keith; Quateen, Ahmed; Walji, Anil

    2009-04-01

    Calvarial diploic venous anatomy has been studied post-mortem, but few studies have addressed these venous structures in-vivo. Previous work in our laboratory has shown that intraosseous infusion through the skull diploic space near the diploic veins in animals and humans does access the superior sagittal sinus and the systemic venous system. We developed a volumetric method of imaging the diploic veins in-vivo using MRI, intravenous gadolinium, and digital subtraction to provide for three-dimensional depiction and exact localization of these veins. We hypothesized that this technique would allow for an assessment of the probability of existence, distribution, and concentration of diploic veins in the skull. We scanned 31 neurosurgical patients, and were able to create 3D diploic venous maps in 74% of them. These maps were processed using Adobe Photoshop CS2. Mathworks MatLab 6.5, once customized, counted the number of pixels occupied by the diploic veins in the processed image. The probability of veins was highest in the occipital regions (100%). The inferior occipital (4.1%) and posterior parietal (4.1%) regions had the highest concentrations of diploic veins. Digital subtraction venography using a volumetric MRI sequence can demonstrate the diploic veins in-vivo. The inferior occipital region may be the best area for an intraosseous infusion device because it has the greatest likelihood of containing a vein and also has the highest concentration of veins. PMID:19173254

  2. A guide to studying human hair follicle cycling in vivo

    PubMed Central

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A.; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan

    2015-01-01

    Hair follicles (HFs) undergo life-long cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative “quiescence” (telogen). Since HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. While available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. Here, we present such a guide, which uses objective, well-defined, and reproducible criteria and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in sub-optimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field. PMID:26763421

  3. In vivo degeneration and the fate of inorganic nanoparticles.

    PubMed

    Feliu, Neus; Docter, Dominic; Heine, Markus; Del Pino, Pablo; Ashraf, Sumaira; Kolosnjaj-Tabi, Jelena; Macchiarini, Paolo; Nielsen, Peter; Alloyeau, Damien; Gazeau, Florence; Stauber, Roland H; Parak, Wolfgang J

    2016-05-01

    What happens to inorganic nanoparticles (NPs), such as plasmonic gold or silver, superparamagnetic iron oxide, or fluorescent quantum dot NPs after they have been administrated to a living being? This review discusses the integrity, biodistribution, and fate of NPs after in vivo administration. The hybrid nature of the NPs is described, conceptually divided into the inorganic core, the engineered surface coating comprising of the ligand shell and optionally also bio-conjugates, and the corona of adsorbed biological molecules. Empirical evidence shows that all of these three compounds may degrade individually in vivo and can drastically modify the life cycle and biodistribution of the whole heterostructure. Thus, the NPs may be decomposed into different parts, whose biodistribution and fate would need to be analyzed individually. Multiple labeling and quantification strategies for such a purpose will be discussed. All reviewed data indicate that NPs in vivo should no longer be considered as homogeneous entities, but should be seen as inorganic/organic/biological nano-hybrids with complex and intricately linked distribution and degradation pathways. PMID:26862602

  4. A Statistical Model for In Vivo Neuronal Dynamics

    PubMed Central

    Surace, Simone Carlo; Pfister, Jean-Pascal

    2015-01-01

    Single neuron models have a long tradition in computational neuroscience. Detailed biophysical models such as the Hodgkin-Huxley model as well as simplified neuron models such as the class of integrate-and-fire models relate the input current to the membrane potential of the neuron. Those types of models have been extensively fitted to in vitro data where the input current is controlled. Those models are however of little use when it comes to characterize intracellular in vivo recordings since the input to the neuron is not known. Here we propose a novel single neuron model that characterizes the statistical properties of in vivo recordings. More specifically, we propose a stochastic process where the subthreshold membrane potential follows a Gaussian process and the spike emission intensity depends nonlinearly on the membrane potential as well as the spiking history. We first show that the model has a rich dynamical repertoire since it can capture arbitrary subthreshold autocovariance functions, firing-rate adaptations as well as arbitrary shapes of the action potential. We then show that this model can be efficiently fitted to data without overfitting. We finally show that this model can be used to characterize and therefore precisely compare various intracellular in vivo recordings from different animals and experimental conditions. PMID:26571371

  5. Portable XRF Technology to Quantify Pb in Bone In Vivo.

    PubMed

    Specht, Aaron James; Weisskopf, Marc; Nie, Linda Huiling

    2014-01-01

    Lead is a ubiquitous toxicant. Bone lead has been established as an important biomarker for cumulative lead exposures and has been correlated with adverse health effects on many systems in the body. K-shell X-ray fluorescence (KXRF) is the standard method for measuring bone lead, but this approach has many difficulties that have limited the widespread use of this exposure assessment method. With recent advancements in X-ray fluorescence (XRF) technology, we have developed a portable system that can quantify lead in bone in vivo within 3 minutes. Our study investigated improvements to the system, four calibration methods, and system validation for in vivo measurements. Our main results show that the detection limit of the system is 2.9 ppm with 2 mm soft tissue thickness, the best calibration method for in vivo measurement is background subtraction, and there is strong correlation between KXRF and portable LXRF bone lead results. Our results indicate that the technology is ready to be used in large human population studies to investigate adverse health effects of lead exposure. The portability of the system and fast measurement time should allow for this technology to greatly advance the research on lead exposure and public/environmental health. PMID:26317033

  6. Circulation times of cancer cells by in vivo flow cytometry

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Li, Yan; Gu, Zhengqin; Chen, Tong; Wang, Cheng; Wei, Xunbin

    2012-03-01

    Liver cancer is one of the most common malignancies in the world, with approximately 1,000,000 cases reported every year. Hepatocellular carcinoma may metastasize to lung, bones, kidney, and many other organs. Surgical resection, liver transplantation, chemotherapy and radiation therapy are the foundation of current HCC therapies. However the outcomes are poor: the survival rate is almost zero for metastatic HCC patients. Molecular mechanisms of HCC metastasis need to be understood better and new therapies must be developed. A recently developed "in vivo flow cytometer" combined with real-time confocal fluorescence imaging are used to assess spreading and the circulation kinetics of liver tumor cells. The in vivo flow cytometer has the capability to detect and quantify continuously the number and flow characteristics of fluorescently labeled cells in vivo in real time without extracting blood sample. We have measured the depletion kinetics of two related human HCC cell lines, high-metastatic HCCLM3 cells and low-metastatic HepG2 cells, which were from the same origin and obtained by repetitive screenings in mice. >60% HCCLM3 cells are depleted within the first hour. Interestingly, the low-metastatic HepG2 cells possess noticeably slower depletion kinetics. In comparison, <40% HepG2 cells are depleted within the first hour. The differences in depletion kinetics might provide insights into early metastasis processes.

  7. Aspartame induces angiogenesis in vitro and in vivo models.

    PubMed

    Yesildal, F; Aydin, F N; Deveci, S; Tekin, S; Aydin, I; Mammadov, R; Fermanli, O; Avcu, F; Acikel, C H; Ozgurtas, T

    2015-03-01

    Angiogenesis is the process of generating new blood vessels from preexisting vessels and is considered essential in many pathological conditions. The purpose of the present study is to evaluate the effect of aspartame on angiogenesis in vivo chick chorioallantoic membrane (CAM) and wound-healing models as well as in vitro 2,3-bis-2H-tetrazolium-5-carboxanilide (XTT) and tube formation assays. In CAM assay, aspartame increased angiogenesis in a concentration-dependent manner. Compared with the control group, aspartame has significantly increased vessel proliferation (p < 0.001). In addition, in vivo rat model of skin wound-healing study showed that aspartame group had better healing than control group, and this was statistically significant at p < 0.05. There was a slight proliferative effect of aspartame on human umbilical vein endothelial cells on XTT assay in vitro, but it was not statistically significant; and there was no antiangiogenic effect of aspartame on tube formation assay in vitro. These results provide evidence that aspartame induces angiogenesis in vitro and in vivo; so regular use may have undesirable effect on susceptible cases.

  8. Mitochondrially targeted p53 has tumor suppressor activities in vivo.

    PubMed

    Talos, Flaminia; Petrenko, Oleksi; Mena, Patricio; Moll, Ute M

    2005-11-01

    Complex proapoptotic functions are essential for the tumor suppressor activity of p53. We recently described a novel transcription-independent mechanism that involves a rapid proapoptotic action of p53 at the mitochondria and executes the shortest known circuitry of p53 death signaling. Here, we examine if this p53-dependent mitochondrial program could be exploited for tumor suppression in vivo. To test this, we engage Emu-Myc transgenic mice, a well-established model of p53-dependent lymphomagenesis. We show that exclusive delivery of p53 to the outer mitochondrial membrane confers a significant growth disadvantage on Emu-Myc-transformed B-cells of p53-deficient or alternate reading frame-deficient genotypes, resulting in efficient induction of apoptosis and impinged proliferation. Conversely, normal cells from thymus, spleen, and bone marrow showed poor infectivity with these viruses. This proof-of-principle experiment shows that exclusive reliance on the direct mitochondrial program exerts a significant tumor suppressor activity in vivo. Our in vivo data on the direct mitochondrial apoptotic p53 program lays the groundwork to further investigate its efficacy and safety and to address its possible therapeutic value in the future.

  9. In vivo assessment of NuvaRing placement.

    PubMed

    Barnhart, Kurt T; Timbers, Kelly; Pretorius, E Scott; Lin, Kathleen; Shaunik, Alka

    2005-09-01

    NuvaRing, a combined contraceptive vaginal ring 54 mm in diameter, offers many advantages over oral contraceptives. To better delineate in vivo placement, we performed MRI to confirm its anatomical position. Two healthy users, one nulliparous and one parous, underwent a series of MRI: preinsertion, immediately postinsertion and after ambulation. Three-dimensional imaging of the human vagina demonstrates that in vivo, NuvaRing is located superior to the urogenital diaphragm (UGD), surrounding the cervix. The superior-most aspect of the ring lies behind (posterior) the cervix, at a level superior to the external os. The inferior aspect of the ring also lies in the vaginal canal above the UGD. The entire cervix rests inside the ring. The preambulation image in the nulliparous woman was the only exception. In this case, the upper portion of the ring was at the level of the lower-mid cervix and the lower aspect below the UGD. After ambulation, the ring moved cephalad and surrounded the cervix. In all instances, ambulation resulted in lower aspect of NuvaRing moving away from the introitus. In vivo, NuvaRing is compressed laterally forming a gentle oval in the anterior-posterior direction (5-7 mm longer than wide), an effect that is seen more in nulliparous women.

  10. In Vivo Evaluation of Wearable Head Impact Sensors.

    PubMed

    Wu, Lyndia C; Nangia, Vaibhav; Bui, Kevin; Hammoor, Bradley; Kurt, Mehmet; Hernandez, Fidel; Kuo, Calvin; Camarillo, David B

    2016-04-01

    Inertial sensors are commonly used to measure human head motion. Some sensors have been tested with dummy or cadaver experiments with mixed results, and methods to evaluate sensors in vivo are lacking. Here we present an in vivo method using high speed video to test teeth-mounted (mouthguard), soft tissue-mounted (skin patch), and headgear-mounted (skull cap) sensors during 6-13 g sagittal soccer head impacts. Sensor coupling to the skull was quantified by displacement from an ear-canal reference. Mouthguard displacements were within video measurement error (<1 mm), while the skin patch and skull cap displaced up to 4 and 13 mm from the ear-canal reference, respectively. We used the mouthguard, which had the least displacement from skull, as the reference to assess 6-degree-of-freedom skin patch and skull cap measurements. Linear and rotational acceleration magnitudes were over-predicted by both the skin patch (with 120% NRMS error for a(mag), 290% for α(mag)) and the skull cap (320% NRMS error for a(mag), 500% for α(mag)). Such over-predictions were largely due to out-of-plane motion. To model sensor error, we found that in-plane skin patch linear acceleration in the anterior-posterior direction could be modeled by an underdamped viscoelastic system. In summary, the mouthguard showed tighter skull coupling than the other sensor mounting approaches. Furthermore, the in vivo methods presented are valuable for investigating skull acceleration sensor technologies.

  11. Favipiravir elicits antiviral mutagenesis during virus replication in vivo

    PubMed Central

    Arias, Armando; Thorne, Lucy; Goodfellow, Ian

    2014-01-01

    Lethal mutagenesis has emerged as a novel potential therapeutic approach to treat viral infections. Several studies have demonstrated that increases in the high mutation rates inherent to RNA viruses lead to viral extinction in cell culture, but evidence during infections in vivo is limited. In this study, we show that the broad-range antiviral nucleoside favipiravir reduces viral load in vivo by exerting antiviral mutagenesis in a mouse model for norovirus infection. Increased mutation frequencies were observed in samples from treated mice and were accompanied with lower or in some cases undetectable levels of infectious virus in faeces and tissues. Viral RNA isolated from treated animals showed reduced infectivity, a feature of populations approaching extinction during antiviral mutagenesis. These results suggest that favipiravir can induce norovirus mutagenesis in vivo, which in some cases leads to virus extinction, providing a proof-of-principle for the use of favipiravir derivatives or mutagenic nucleosides in the clinical treatment of noroviruses. DOI: http://dx.doi.org/10.7554/eLife.03679.001 PMID:25333492

  12. In vivo dosimetry with silicon diodes in total body irradiation

    NASA Astrophysics Data System (ADS)

    Oliveira, F. F.; Amaral, L. L.; Costa, A. M.; Netto, T. G.

    2014-02-01

    The aim of this work is the characterization and application of silicon diode detectors for in vivo dosimetry in total body irradiation (TBI) treatments. It was evaluated the diode response with temperature, dose rate, gantry angulations and field size. A maximum response variation of 2.2% was obtained for temperature dependence. The response variation for dose rate and angular was within 1.2%. For field size dependence, the detector response increased with field until reach a saturation region, where no more primary radiation beam contributes for dose. The calibration was performed in a TBI setup. Different lateral thicknesses from one patient were simulated and then the calibration factors were determined by means of maximum depth dose readings. Subsequent to calibration, in vivo dosimetry measurements were performed. The response difference between diode readings and the prescribed dose for all treatments was below 4%. This difference is in agreement as recommended by the International Commission on Radiation Units and Measurements (ICRU), which is ±5%. The present work to test the applicability of a silicon diode dosimetry system for performing in vivo dose measurements in TBI techniques presented good results. These measurements demonstrated the value of diode dosimetry as a treatment verification method and its applicability as a part of a quality assurance program in TBI treatments.

  13. A crystal-clear zebrafish for in vivo imaging.

    PubMed

    Antinucci, Paride; Hindges, Robert

    2016-01-01

    The larval zebrafish (Danio rerio) is an excellent vertebrate model for in vivo imaging of biological phenomena at subcellular, cellular and systems levels. However, the optical accessibility of highly pigmented tissues, like the eyes, is limited even in this animal model. Typical strategies to improve the transparency of zebrafish larvae require the use of either highly toxic chemical compounds (e.g. 1-phenyl-2-thiourea, PTU) or pigmentation mutant strains (e.g. casper mutant). To date none of these strategies produce normally behaving larvae that are transparent in both the body and the eyes. Here we present crystal, an optically clear zebrafish mutant obtained by combining different viable mutations affecting skin pigmentation. Compared to the previously described combinatorial mutant casper, the crystal mutant lacks pigmentation also in the retinal pigment epithelium, therefore enabling optical access to the eyes. Unlike PTU-treated animals, crystal larvae are able to perform visually guided behaviours, such as the optomotor response, as efficiently as wild type larvae. To validate the in vivo application of crystal larvae, we performed whole-brain light-sheet imaging and two-photon calcium imaging of neural activity in the retina. In conclusion, this novel combinatorial pigmentation mutant represents an ideal vertebrate tool for completely unobstructed structural and functional in vivo investigations of biological processes, particularly when imaging tissues inside or between the eyes.

  14. Analysis of leukocyte rolling in vivo and in vitro.

    PubMed

    Sperandio, Markus; Pickard, John; Unnikrishnan, Sunil; Acton, Scott T; Ley, Klaus

    2006-01-01

    Leukocyte rolling is an important step for the successful recruitment of leukocytes from blood to tissues mediated by a specialized group of glycoproteins termed selectins. Because of the dynamic process of leukocyte rolling, binding of selectins to their respective counter-receptors (selectin ligands) needs to fulfill three major requirements: (1) rapid bond formation, (2) high tensile strength, and (3) fast dissociation rates. These criteria are perfectly met by selectins, which interact with specific carbohydrate determinants on selectin ligands. This chapter describes the theoretical background, technical requirements, and analytical tools needed to quantitatively assess leukocyte rolling in vivo and in vitro. For the in vivo setting, intravital microscopy allows the observation and recording of leukocyte rolling under different physiological and pathological conditions in almost every organ. Real-time and off-line analysis tools help to assess geometric, hemodynamic, and rolling parameters. Under in vitro conditions, flow chamber assays such as parallel plate flow chamber systems have been the mainstay to study interactions between leukocytes and adhesion molecules under flow. In this setting, adhesion molecules are immobilized on plastic, in a lipid monolayer, or presented on cultured endothelial cells on the chamber surface. Microflow chambers are available for studying leukocyte adhesion in the context of whole blood and without blood cell isolation. The microscopic observation of leukocyte rolling in different in vivo and in vitro settings has significantly contributed to our understanding of the molecular mechanisms responsible for the stepwise extravasation of leukocytes into inflamed tissues.

  15. Structural imprints in vivo decode RNA regulatory mechanisms

    NASA Astrophysics Data System (ADS)

    Spitale, Robert C.; Flynn, Ryan A.; Zhang, Qiangfeng Cliff; Crisalli, Pete; Lee, Byron; Jung, Jong-Wha; Kuchelmeister, Hannes Y.; Batista, Pedro J.; Torre, Eduardo A.; Kool, Eric T.; Chang, Howard Y.

    2015-03-01

    Visualizing the physical basis for molecular behaviour inside living cells is a great challenge for biology. RNAs are central to biological regulation, and the ability of RNA to adopt specific structures intimately controls every step of the gene expression program. However, our understanding of physiological RNA structures is limited; current in vivo RNA structure profiles include only two of the four nucleotides that make up RNA. Here we present a novel biochemical approach, in vivo click selective 2'-hydroxyl acylation and profiling experiment (icSHAPE), which enables the first global view, to our knowledge, of RNA secondary structures in living cells for all four bases. icSHAPE of the mouse embryonic stem cell transcriptome versus purified RNA folded in vitro shows that the structural dynamics of RNA in the cellular environment distinguish different classes of RNAs and regulatory elements. Structural signatures at translational start sites and ribosome pause sites are conserved from in vitro conditions, suggesting that these RNA elements are programmed by sequence. In contrast, focal structural rearrangements in vivo reveal precise interfaces of RNA with RNA-binding proteins or RNA-modification sites that are consistent with atomic-resolution structural data. Such dynamic structural footprints enable accurate prediction of RNA-protein interactions and N6-methyladenosine (m6A) modification genome wide. These results open the door for structural genomics of RNA in living cells and reveal key physiological structures controlling gene expression.

  16. Effect of desipramine on dopamine receptor binding in vivo

    SciTech Connect

    Suhara, Tetsuya Jikei Univ., Tokyo ); Inoue, Osamu; Kobayasi, Kaoru )

    1990-01-01

    Effect of desipramine on the in vivo binding of {sup 3}H-SCH23390 and {sup 3}H-N-methylspiperone ({sup 3}H-NMSP) in mouse striatum was studied. The ratio of radioactivity in the striatum to that in the cerebellum at 15 min after i.v. injection of {sup 3}H-SCH23390 or 45 min after injection of {sup 3}H-NMSP were used as indices of dopamine D1 or D2 receptor binding in vivo, respectively. In vivo binding of D1 and D2 receptors was decreased in a dose-dependent manner by acute treatment with desipramine (DMI). A saturation experiment suggested that the DMI-induced reduction in the binding was mainly due to the decrease in the affinity of both receptors. No direct interactions between the dopamine receptors and DMI were observed in vitro by the addition of 1 mM of DMI into striatal homogenate. Other antidepressants such as imipramine, clomipramine, maprotiline and mianserin also decreased the binding of dopamine D1 and D2 receptors. The results indicated an important role of dopamine receptors in the pharmacological effect of antidepressants.

  17. Organelle acidification negatively regulates vacuole membrane fusion in vivo

    PubMed Central

    Desfougères, Yann; Vavassori, Stefano; Rompf, Maria; Gerasimaite, Ruta; Mayer, Andreas

    2016-01-01

    The V-ATPase is a proton pump consisting of a membrane-integral V0 sector and a peripheral V1 sector, which carries the ATPase activity. In vitro studies of yeast vacuole fusion and evidence from worms, flies, zebrafish and mice suggested that V0 interacts with the SNARE machinery for membrane fusion, that it promotes the induction of hemifusion and that this activity requires physical presence of V0 rather than its proton pump activity. A recent in vivo study in yeast has challenged these interpretations, concluding that fusion required solely lumenal acidification but not the V0 sector itself. Here, we identify the reasons for this discrepancy and reconcile it. We find that acute pharmacological or physiological inhibition of V-ATPase pump activity de-acidifies the vacuole lumen in living yeast cells within minutes. Time-lapse microscopy revealed that de-acidification induces vacuole fusion rather than inhibiting it. Cells expressing mutated V0 subunits that maintain vacuolar acidity were blocked in this fusion. Thus, proton pump activity of the V-ATPase negatively regulates vacuole fusion in vivo. Vacuole fusion in vivo does, however, require physical presence of a fusion-competent V0 sector. PMID:27363625

  18. Nanosensor aided photoacoustic measurement of pH in vivo

    NASA Astrophysics Data System (ADS)

    Ray, Aniruddha; Yoon, Hyung Ki; Kopelman, Raoul; Wang, Xueding

    2013-03-01

    pH plays a critical role in many aspects of cell and tissues physiology. Lower pH is also a typical characteristic of arthritic joints and tumor tissues. These pH anomalies are also exploited in different drug delivery mechanisms. Here we present, a new method of pH sensing in vivo using spectroscopic photoacoustic measurements facilitated by pH sensitive nanosensors. The nanosensors consist of Seminaphtharhodafluor (SNARF), a pH sensitive dye, encapsulated in a specially designed polyacrylamide hydrogel matrix with a hydrophobic core. The photoacoustic intensity ratio between the excitation wavelengths of 585nm and 565nm increases in the pH range from 6.0 to 8.0 and is used to determine the pH of the local environment. These nanosensors are biodegradable, biocompatible, have a long plasma lifetime and can be targeted to any type of cells or tissues by surface modification using proper targeting moieties. The encapsulation of the dye prevents the interaction of the dye with proteins in plasma and also reduces the dye degradation. The SNARF dye in its free form loses 90% of its absorbance in presence of albumin, a protein found in abundance in plasma, and this has severely limited its adaptation to in vivo environments. In comparison, the SNARF nanosensors lose only 16% of their absorbance in the same environment. We employ these nanosensors to demonstrate the feasibility of pH sensing in vivo through photoacoustic measurements on a rat joint model.

  19. Imaging of gene expression in vivo with photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Li, Li; Zemp, Roger J.; Lungu, Gina; Stoica, George; Wang, Lihong V.

    2006-02-01

    In the post-genomic era, there is an increasing interest in visualizing the expression of functional genes in vivo. With the assistance of the reporter gene technique, various imaging modalities have been adopted for this purpose. In vivo gene expression imaging promises to provide biologists with a powerful tool for deepening our understanding of developmental biology, expanding our knowledge of the genetic basis of disease, and advancing the development of medicine. In this paper, we demonstrate the feasibility of imaging gene expression with photoacoustic imaging, which offers unique absorption contrast with ultrasonic resolution in vivo. We mark tumors in rats with the lacZ reporter gene. The lacZ gene encodes an enzyme β-galactosidase, which yields a dark blue product when acting on a colorimetric assay called X-gal. Photoacoustic tomography at 650nm clearly visualizes the presence of this blue product. The spectroscopic method can also potentially improve specificity. Considering how many staining methods are used in traditional biology, we believe that photoacoustic techniques will revolutionize the field of molecular imaging. The further development of reporter gene systems with high absorbing products in the NIR region is needed.

  20. Organelle acidification negatively regulates vacuole membrane fusion in vivo.

    PubMed

    Desfougères, Yann; Vavassori, Stefano; Rompf, Maria; Gerasimaite, Ruta; Mayer, Andreas

    2016-07-01

    The V-ATPase is a proton pump consisting of a membrane-integral V0 sector and a peripheral V1 sector, which carries the ATPase activity. In vitro studies of yeast vacuole fusion and evidence from worms, flies, zebrafish and mice suggested that V0 interacts with the SNARE machinery for membrane fusion, that it promotes the induction of hemifusion and that this activity requires physical presence of V0 rather than its proton pump activity. A recent in vivo study in yeast has challenged these interpretations, concluding that fusion required solely lumenal acidification but not the V0 sector itself. Here, we identify the reasons for this discrepancy and reconcile it. We find that acute pharmacological or physiological inhibition of V-ATPase pump activity de-acidifies the vacuole lumen in living yeast cells within minutes. Time-lapse microscopy revealed that de-acidification induces vacuole fusion rather than inhibiting it. Cells expressing mutated V0 subunits that maintain vacuolar acidity were blocked in this fusion. Thus, proton pump activity of the V-ATPase negatively regulates vacuole fusion in vivo. Vacuole fusion in vivo does, however, require physical presence of a fusion-competent V0 sector.

  1. A crystal-clear zebrafish for in vivo imaging

    PubMed Central

    Antinucci, Paride; Hindges, Robert

    2016-01-01

    The larval zebrafish (Danio rerio) is an excellent vertebrate model for in vivo imaging of biological phenomena at subcellular, cellular and systems levels. However, the optical accessibility of highly pigmented tissues, like the eyes, is limited even in this animal model. Typical strategies to improve the transparency of zebrafish larvae require the use of either highly toxic chemical compounds (e.g. 1-phenyl-2-thiourea, PTU) or pigmentation mutant strains (e.g. casper mutant). To date none of these strategies produce normally behaving larvae that are transparent in both the body and the eyes. Here we present crystal, an optically clear zebrafish mutant obtained by combining different viable mutations affecting skin pigmentation. Compared to the previously described combinatorial mutant casper, the crystal mutant lacks pigmentation also in the retinal pigment epithelium, therefore enabling optical access to the eyes. Unlike PTU-treated animals, crystal larvae are able to perform visually guided behaviours, such as the optomotor response, as efficiently as wild type larvae. To validate the in vivo application of crystal larvae, we performed whole-brain light-sheet imaging and two-photon calcium imaging of neural activity in the retina. In conclusion, this novel combinatorial pigmentation mutant represents an ideal vertebrate tool for completely unobstructed structural and functional in vivo investigations of biological processes, particularly when imaging tissues inside or between the eyes. PMID:27381182

  2. In vivo imaging of IFT in Chlamydomonas flagella.

    PubMed

    Lechtreck, Karl F

    2013-01-01

    Intraflagellar transport (IFT) is a specialized intracellular transport which is required for the assembly and maintenance of cilia and eukaryotic flagella. IFT protein particles move bidirectionally along the flagella in the space between the flagellar membrane and the axonemal doublets. The particles consist of more than 20 different polypeptides and are transported by kinesin-2 from the cell body to the flagellar tip and by cytoplasmic dynein back to the cell body. Chlamydomonas reinhardtii is unique in that IFT can be visualized by two distinct microscopic approaches: differential interference contrast (DIC) and tracking of fluorescently tagged IFT proteins. In vivo imaging of IFT is critical to determine, for example, the role of individual proteins in the IFT pathway and how flagellar proteins are transported by IFT. Here, the microscopic requirements and the procedures for the imaging of IFT by DIC and by total internal reflection fluorescence microscopy will be described. Kymograms, graphical representations of spatial position over time, provide a convenient way to analyze in vivo recordings of IFT. In the future, multicolor in vivo imaging of IFT and its cargoes will be used to understand how flagella are assembled, maintained, and repaired.

  3. In vivo enzyme activity in inborn errors of metabolism

    SciTech Connect

    Thompson, G.N.; Walter, J.H.; Leonard, J.V.; Halliday, D. )

    1990-08-01

    Low-dose continuous infusions of (2H5)phenylalanine, (1-13C)propionate, and (1-13C)leucine were used to quantitate phenylalanine hydroxylation in phenylketonuria (PKU, four subjects), propionate oxidation in methylmalonic acidaemia (MMA, four subjects), and propionic acidaemia (PA, four subjects) and leucine oxidation in maple syrup urine disease (MSUD, four subjects). In vivo enzyme activity in PKU, MMA, and PA subjects was similar to or in excess of that in adult controls (range of phenylalanine hydroxylation in PKU, 3.7 to 6.5 mumol/kg/h, control 3.2 to 7.9, n = 7; propionate oxidation in MMA, 15.2 to 64.8 mumol/kg/h, and in PA, 11.1 to 36.0, control 5.1 to 19.0, n = 5). By contrast, in vivo leucine oxidation was undetectable in three of the four MSUD subjects (less than 0.5 mumol/kg/h) and negligible in the remaining subject (2 mumol/kg/h, control 10.4 to 15.7, n = 6). These results suggest that significant substrate removal can be achieved in some inborn metabolic errors either through stimulation of residual enzyme activity in defective enzyme systems or by activation of alternate metabolic pathways. Both possibilities almost certainly depend on gross elevation of substrate concentrations. By contrast, only minimal in vivo oxidation of leucine appears possible in MSUD.

  4. A historically significant shield for in vivo measurements.

    PubMed

    Lynch, Timothy P

    2007-08-01

    Due to the ubiquitous nature of ionizing radiation, in vivo measurement systems designed to measure low levels of radionuclides in people are usually enclosed within a high-density shield. Lead, steel, earth, and water are just some of the materials that have been and are being used to shield the detectors from radiations of cosmic, atmospheric, man-made, and terrestrial origin. At many Department of Energy sites, the counting room shields are constructed of pre-World War II steel to reduce the background levels in order to perform measurements that have low minimum detectable activities. The pre-World War II steel is commonly called low background steel in the in vivo industry vernacular. The low background descriptor comes from the fact the steel was manufactured prior to the beginning of atmospheric testing of nuclear weapons in the 1940's. Consequently, the steel is not likely to be contaminated with fission or activation products from fallout. For high energy photons (600 keV < E < 1500 keV), 30 cm of steel shielding significantly reduces the measured background radiation levels. This is the story of the unique steel that began as the hull of the U.S.S. Indiana and now forms a shielded room at the In Vivo Radiobioassay and Research Facility in Richland, Washington.

  5. Identification of Enterococcus faecalis antigens specifically expressed in vivo

    PubMed Central

    Shet, Uttom K.; Park, Sang-Won; Lim, Hyun-Pil; Yun, Kwi-Dug; Kang, Seong Soo; Kim, Se Eun

    2015-01-01

    Objectives Molecular mechanism of the pathogenicity of Enterococcus faecalis (E. faecalis), a suspected endodontic pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here we report the identification of in vivo expressed antigens of E. faecalis by using a novel immunoscreening technique called change-mediated antigen technology (CMAT) and an experimental animal model of endodontic infection. Materials and Methods Among 4,500 E. coli recombinant clones screened, 19 positive clones reacted reproducibly with hyperimmune sera obtained from rabbits immunized with E. faecalis cells isolated from an experimental endodontic infection. DNA sequences from 16 of these in vivo-induced (IVI) genes were determined. Results Identified protein antigens of E. faecalis included enzymes involved in housekeeping functions, copper resistance protein, putative outer membrane proteins, and proteins of unknown function. Conclusions In vivo expressed antigens of E. faecalis could be identified by using a novel immune-screening technique CMAT and an experimental animal model of endodontic infection. Detailed analysis of these IVI genes will lead to a better understanding of the molecular mechanisms involved in the endodontic infection of E. faecalis. PMID:26587417

  6. Structural imprints in vivo decode RNA regulatory mechanisms

    PubMed Central

    Spitale, Robert C.; Flynn, Ryan A.; Zhang, Qiangfeng Cliff; Crisalli, Pete; Lee, Byron; Jung, Jong-Wha; Kuchelmeister, Hannes Y.; Batista, Pedro J.; Torre, Eduardo A.; Kool, Eric T.; Chang, Howard Y.

    2015-01-01

    Visualizing the physical basis for molecular behavior inside living cells is a grand challenge in biology. RNAs are central to biological regulation, and RNA’s ability to adopt specific structures intimately controls every step of the gene expression program1. However, our understanding of physiological RNA structures is limited; current in vivo RNA structure profiles view only two of four nucleotides that make up RNA2,3. Here we present a novel biochemical approach, In Vivo Click SHAPE (icSHAPE), that enables the first global view of RNA secondary structures of all four bases in living cells. icSHAPE of mouse embryonic stem cell transcriptome versus purified RNA folded in vitro shows that the structural dynamics of RNA in the cellular environment distinguishes different classes of RNAs and regulatory elements. Structural signatures at translational start sites and ribosome pause sites are conserved from in vitro, suggesting that these RNA elements are programmed by sequence. In contrast, focal structural rearrangements in vivo reveal precise interfaces of RNA with RNA binding proteins or RNA modification sites that are consistent with atomic-resolution structural data. Such dynamic structural footprints enable accurate prediction of RNA-protein interactions and N6-methyladenosine (m6A) modification genome-wide. These results open the door for structural genomics of RNA in living cells and reveal key physiological structures controlling gene expression. PMID:25799993

  7. FANCA safeguards interphase and mitosis during hematopoiesis in vivo.

    PubMed

    Abdul-Sater, Zahi; Cerabona, Donna; Potchanant, Elizabeth Sierra; Sun, Zejin; Enzor, Rikki; He, Ying; Robertson, Kent; Goebel, W Scott; Nalepa, Grzegorz

    2015-12-01

    The Fanconi anemia (FA/BRCA) signaling network controls multiple genome-housekeeping checkpoints, from interphase DNA repair to mitosis. The in vivo role of abnormal cell division in FA remains unknown. Here, we quantified the origins of genomic instability in FA patients and mice in vivo and ex vivo. We found that both mitotic errors and interphase DNA damage significantly contribute to genomic instability during FA-deficient hematopoiesis and in nonhematopoietic human and murine FA primary cells. Super-resolution microscopy coupled with functional assays revealed that FANCA shuttles to the pericentriolar material to regulate spindle assembly at mitotic entry. Loss of FA signaling rendered cells hypersensitive to spindle chemotherapeutics and allowed escape from the chemotherapy-induced spindle assembly checkpoint. In support of these findings, direct comparison of DNA crosslinking and anti-mitotic chemotherapeutics in primary FANCA-/- cells revealed genomic instability originating through divergent cell cycle checkpoint aberrations. Our data indicate that FA/BRCA signaling functions as an in vivo gatekeeper of genomic integrity throughout interphase and mitosis, which may have implications for future targeted therapies in FA and FA-deficient cancers.

  8. Portable XRF Technology to Quantify Pb in Bone In Vivo

    PubMed Central

    Specht, Aaron James; Weisskopf, Marc; Nie, Linda Huiling

    2014-01-01

    Lead is a ubiquitous toxicant. Bone lead has been established as an important biomarker for cumulative lead exposures and has been correlated with adverse health effects on many systems in the body. K-shell X-ray fluorescence (KXRF) is the standard method for measuring bone lead, but this approach has many difficulties that have limited the widespread use of this exposure assessment method. With recent advancements in X-ray fluorescence (XRF) technology, we have developed a portable system that can quantify lead in bone in vivo within 3 minutes. Our study investigated improvements to the system, four calibration methods, and system validation for in vivo measurements. Our main results show that the detection limit of the system is 2.9 ppm with 2 mm soft tissue thickness, the best calibration method for in vivo measurement is background subtraction, and there is strong correlation between KXRF and portable LXRF bone lead results. Our results indicate that the technology is ready to be used in large human population studies to investigate adverse health effects of lead exposure. The portability of the system and fast measurement time should allow for this technology to greatly advance the research on lead exposure and public/environmental health. PMID:26317033

  9. Portable XRF Technology to Quantify Pb in Bone In Vivo.

    PubMed

    Specht, Aaron James; Weisskopf, Marc; Nie, Linda Huiling

    2014-01-01

    Lead is a ubiquitous toxicant. Bone lead has been established as an important biomarker for cumulative lead exposures and has been correlated with adverse health effects on many systems in the body. K-shell X-ray fluorescence (KXRF) is the standard method for measuring bone lead, but this approach has many difficulties that have limited the widespread use of this exposure assessment method. With recent advancements in X-ray fluorescence (XRF) technology, we have developed a portable system that can quantify lead in bone in vivo within 3 minutes. Our study investigated improvements to the system, four calibration methods, and system validation for in vivo measurements. Our main results show that the detection limit of the system is 2.9 ppm with 2 mm soft tissue thickness, the best calibration method for in vivo measurement is background subtraction, and there is strong correlation between KXRF and portable LXRF bone lead results. Our results indicate that the technology is ready to be used in large human population studies to investigate adverse health effects of lead exposure. The portability of the system and fast measurement time should allow for this technology to greatly advance the research on lead exposure and public/environmental health.

  10. High altitude impairs in vivo immunity in humans.

    PubMed

    Oliver, Samuel J; Macdonald, Jamie H; Harper Smith, Adam D; Lawley, Justin S; Gallagher, Carla A; Di Felice, Umberto; Walsh, Neil P

    2013-06-01

    The aim was to assess the effect of high altitude on the development of new immune memory (induction) using a contact sensitization model of in vivo immunity. We hypothesized that high-altitude exposure would impair induction of the in vivo immune response to a novel antigen, diphenylcyclopropenone (DPCP). DPCP was applied (sensitization) to the lower back of 27 rested controls at sea level and to ten rested mountaineers 28 hours after passive ascent to 3777 m. After sensitization, mountaineers avoided strenuous exercise for a further 24 hours, after which they completed alpine activities for 11-18 days. Exactly 4 weeks after sensitization, the strength of immune memory induction was quantified in rested mountaineers and controls at sea level, by measuring the response to a low, dose-series DPCP challenge, read at 48 hours as skin measures of edema (skinfold thickness) and redness (erythema). Compared with control responses, skinfold thickness and erythema were reduced in the mountaineers (skinfold thickness,-52%, p=0.01, d=0.86; erythema, -36%, p=0.02, d=0.77). These changes in skinfold thickness and erythema were related to arterial oxygen saturation (r=0.7, p=0.04), but not cortisol (r<0.1, p>0.79), at sensitization. In conclusion, this is the first study to show, using a contact sensitization model of in vivo immunity, that high altitude exposure impairs the development of new immunity in humans.

  11. In vivo imaging with near-infrared fluorescence lifetime contrast

    NASA Astrophysics Data System (ADS)

    Akers, Walter J.; Berezin, Mikhail Y.; Lee, Hyeran; Achilefu, Samuel

    2009-02-01

    Fluorescence imaging is a mainstay of biomedical research, allowing detection of molecular events in both fixed and living cells, tissues and whole animals. Such high resolution fluorescence imaging is hampered by unwanted signal from intrinsic background fluorescence and scattered light. The signal to background ratio can be improved by using extrinsic contrast agents and greatly enhanced by multispectral imaging methods. Unfortunately, these methods are insufficient for deep tissue imaging where high contrast and speedy acquisition are necessary. Fluorescence lifetime (FLT) is an inherent characteristic of each fluorescent species that can be independent of intensity and spectral properties. Accordingly, FLT-based detection provides an additional contrast mechanism to optical measurements. This contrast is particularly important in the near-infrared (NIR) due to relative transparency of tissue as well as the broad absorption and emission spectra of dyes that are active in this region. Here we report comparative analysis of signal distribution of several NIR fluorescent polymethine dyes in living mice and their correlations with lifetimes obtained in vitro using solution models. The FLT data obtained from dyes dissolved in serum albumin solution correlated well with FLTs measured in vivo. Thus the albumin solution model could be used as a good predictive model for in vivo FLT behavior of newly developed fluorescent reporters. Subsequent experiments in vivo, including monitoring slow release kinetics and detecting proteinuria, demonstrate the complementary nature of FLT for fluorescence intensity imaging.

  12. Hazardous potential of manufactured nanoparticles identified by in vivo assay.

    PubMed

    Valant, Janez; Drobne, Damjana; Sepcić, Kristina; Jemec, Anita; Kogej, Ksenija; Kostanjsek, Rok

    2009-11-15

    New products of nanotechnologies, including nanoparticles, need to be assessed according to their biological reactivity and toxic potential. Given the large number of diverse nanomaterials, a tiered approach is favoured. The aim of our work presented here is to elaborate an in vivo assay with terrestrial invertebrates (Porcellio scaber), which could serve as a first step of hazard identification of nanoparticles. We adapted the widely used acridine orange/ethidium bromide (AO/EB) assay to be applicable for cell membrane stability assessment of entire organ where the animal was exposed in vivo. The digestive glands (hepatopancreas) of terrestrial isopods were taken as a model test system. The assay was validated with Cu(NO(3))(2) and surfactants. The results showed that all tested nanoparticles, i.e. nanosized TiO(2), nanosized ZnO and fullerenes (C(60)) have cell membrane destabilization potential. As expected, C(60) is the most biologically potent. The AO/EB in vivo assay proved to be fast because response is recorded after 30 min of exposure, relatively simple because digestive glands are inspected immediately after isolation from exposed animals and promising approach because different types of nanoparticles could be tested for their biological potential. This assay provides data for the identification of hazardous potential of nanoparticles before subsequent steps in a tiered approach are decided.

  13. Infrared neural stimulation of human spinal nerve roots in vivo

    PubMed Central

    Cayce, Jonathan M.; Wells, Jonathon D.; Malphrus, Jonathan D.; Kao, Chris; Thomsen, Sharon; Tulipan, Noel B.; Konrad, Peter E.; Jansen, E. Duco; Mahadevan-Jansen, Anita

    2015-01-01

    Abstract. Infrared neural stimulation (INS) is a neurostimulation modality that uses pulsed infrared light to evoke artifact-free, spatially precise neural activity with a noncontact interface; however, the technique has not been demonstrated in humans. The objective of this study is to demonstrate the safety and efficacy of INS in humans in vivo. The feasibility of INS in humans was assessed in patients (n=7) undergoing selective dorsal root rhizotomy, where hyperactive dorsal roots, identified for transection, were stimulated in vivo with INS on two to three sites per nerve with electromyogram recordings acquired throughout the stimulation. The stimulated dorsal root was removed and histology was performed to determine thermal damage thresholds of INS. Threshold activation of human dorsal rootlets occurred in 63% of nerves for radiant exposures between 0.53 and 1.23  J/cm2. In all cases, only one or two monitored muscle groups were activated from INS stimulation of a hyperactive spinal root identified by electrical stimulation. Thermal damage was first noted at 1.09  J/cm2 and a 2∶1 safety ratio was identified. These findings demonstrate the success of INS as a fresh approach for activating human nerves in vivo and providing the necessary safety data needed to pursue clinically driven therapeutic and diagnostic applications of INS in humans. PMID:26157986

  14. Labeling cells for in vivo tracking using (19)F MRI.

    PubMed

    Srinivas, Mangala; Boehm-Sturm, Philipp; Figdor, Carl G; de Vries, I Jolanda; Hoehn, Mathias

    2012-12-01

    Noninvasive in vivo cell tracking is crucial to fully understand the function of mobile and/or transplanted cells, particularly immune cells and cellular therapeutics. (19)F MRI for cell tracking has several advantages; chief among them are its noninvasive nature which allows longitudinal data acquisition, use of a stable, non-radioactive isotope permitting long-term tracking, the absence of confounding endogenous signal, and the ability to quantify cell numbers from image data. However, generation of sufficient signal i.e. (19)F cell loading is a key challenge, particularly with non-phagocytic cells such as lymphocytes and stem cells. A range of (19)F cell labels have been developed, including emulsions, particles, polymers, and agents for clinical use. Various animal and primary human cells, such as dendritic cells, lymphocytes and phagocytes have been successfully labeled and studied in models of autoimmune disease, inflammation and transplant rejection. Primary human cells, particularly dendritic cells as used in vaccine therapy have been tested for imminent clinical application. Here, we summarize current cell loading strategies and sensitivity of in vivo cell imaging with (19)F MRI, and discuss the processing of image data for accurate quantification of cell numbers. This novel technology is uniquely applicable to the longitudinal and quantitative tracking of cells in vivo.

  15. Synchronization among neuronal pools without common inputs: in vivo study.

    PubMed

    Brama, Haya; Guberman, Shoshana; Abeles, Moshe; Stern, Edward; Kanter, Ido

    2015-11-01

    Periodic synchronization of activity among neuronal pools has been related to substantial neural processes and information throughput in the neocortical network. However, the mechanisms of generating such periodic synchronization among distributed pools of neurons remain unclear. We hypothesize that to a large extent there is interplay between the topology of the neocortical networks and their reverberating modes of activity. The firing synchronization is governed by a nonlocal mechanism, the network delay loops, such that distant neuronal pools without common drives can be synchronized. This theoretical interplay between network topology and the synchronized mode is verified using an iterative procedure of a single intracellularly recorded neuron in vivo, imitating the dynamics of the entire network. The input is injected to the neuron via the recording electrode as current and computed from the filtered, evoked spikes of its pre-synaptic sources, previously emulated by the same neuron. In this manner we approximate subthreshold synaptic inputs from afferent neuronal pools to the neuron. Embedding the activity of these recurrent motifs in the intact brain allows us to measure the effects of connection probability, synaptic strength, and ongoing activity on the neuronal synchrony. Our in vivo experiments indicate that an initial stimulus given to a single pool is dynamically evolving into the formations of zero-lag and cluster synchronization. By applying results from theoretical models and in vitro experiments to in vivo activity in the intact brain, we support the notion that this mechanism may account for the binding activity across distributed brain areas.

  16. HLA-B27/microbial mimicry: an in vivo analysis.

    PubMed Central

    Kapasi, K; Chui, B; Inman, R D

    1992-01-01

    The association between three major spondyloarthritic diseases, ankylosing spondylitis, Reiter's syndrome, and reactive arthritis, and the major histocompatibility complex (MHC) class 1 antigen HLA-B27 is well documented. The hypothesis of cross-reactivity between HLA-B27 and the antecedent infection-causing Gram-negative pathogens such as Salmonella, Shigella and Yersinia has been suggested by in vitro studies employing monoclonal antibodies. We have examined the possibility of such cross-reactivity in vivo using various rabbit immune sera and patient sera as the source of cross-reacting antibody. Mouse L cells were transfected with HLA-A3 or HLA-B27 and used as a source of antigen. Western blot analysis employing denatured antigen, FACS analysis employing native antigen and immunoprecipitation studies were undertaken to detect cross-reacting antibodies generated in vivo to HLA-B27 antigen. Antibodies generated in vivo by infection in patients or immunization in animals against arthritogenic bacteria did not demonstrate any cross-reactivity with HLA-B27 by any of the methods used. As defined by the humoral immune response, molecular mimicry appears unlikely to explain the role of B27 in the pathogenesis of reactive arthritis. Images Figure 2 Figure 3 Figure 6 PMID:1478690

  17. A Historically Significant Shield for In Vivo Measurements

    SciTech Connect

    Lynch, Timothy P.

    2007-08-01

    Due to the ubiquitous nature of ionizing radiation, in vivo measurement systems designed to measure low levels of radionuclides in people are usually enclosed within a high density shield. Lead, steel, earth, and water are just some of the materials that have been and are being used to shield the detectors from radiations of cosmic, atmospheric, and terrestrial origin. At many Department of Energy sites, the counting room shields are constructed of pre-world War II steel to reduce the background levels to achieve measurements with low minimum detectable activities (MDA). This is one example of what is commonly called low background steel in the in vivo industry vernacular. The name arises from the fact the steel was manufactured prior to the beginning of atmospheric testing of nuclear weapons in the 1940s. Consequently, the steel is not likely to be contaminated with fission or activation products from fallout. For high energy photons (600 keV In Vivo Radioassay and Research Facility (IVRRF) in Richland, Washington.

  18. Single-cell analysis of endothelial morphogenesis in vivo

    PubMed Central

    Yu, Jianxin A.; Castranova, Daniel; Pham, Van N.; Weinstein, Brant M.

    2015-01-01

    Vessel formation has been extensively studied at the tissue level, but the difficulty in imaging the endothelium with cellular resolution has hampered study of the morphogenesis and behavior of endothelial cells (ECs) in vivo. We are using endothelial-specific transgenes and high-resolution imaging to examine single ECs in zebrafish. By generating mosaics with transgenes that simultaneously mark endothelial nuclei and membranes we are able to definitively identify and study the morphology and behavior of individual ECs during vessel sprouting and lumen formation. Using these methods, we show that developing trunk vessels are composed of ECs of varying morphology, and that single-cell analysis can be used to quantitate alterations in morphology and dynamics in ECs that are defective in proper guidance and patterning. Finally, we use single-cell analysis of intersegmental vessels undergoing lumen formation to demonstrate the coexistence of seamless transcellular lumens and single or multicellular enclosed lumens with autocellular or intercellular junctions, suggesting that heterogeneous mechanisms contribute to vascular lumen formation in vivo. The tools that we have developed for single EC analysis should facilitate further rigorous qualitative and quantitative analysis of EC morphology and behavior in vivo. PMID:26253401

  19. A Guide to Studying Human Hair Follicle Cycling In Vivo.

    PubMed

    Oh, Ji Won; Kloepper, Jennifer; Langan, Ewan A; Kim, Yongsoo; Yeo, Joongyeub; Kim, Min Ji; Hsi, Tsai-Ching; Rose, Christian; Yoon, Ghil Suk; Lee, Seok-Jong; Seykora, John; Kim, Jung Chul; Sung, Young Kwan; Kim, Moonkyu; Paus, Ralf; Plikus, Maksim V

    2016-01-01

    Hair follicles (HFs) undergo lifelong cyclical transformations, progressing through stages of rapid growth (anagen), regression (catagen), and relative "quiescence" (telogen). Given that HF cycling abnormalities underlie many human hair growth disorders, the accurate classification of individual cycle stages within skin biopsies is clinically important and essential for hair research. For preclinical human hair research purposes, human scalp skin can be xenografted onto immunocompromised mice to study human HF cycling and manipulate long-lasting anagen in vivo. Although available for mice, a comprehensive guide on how to recognize different human hair cycle stages in vivo is lacking. In this article, we present such a guide, which uses objective, well-defined, and reproducible criteria, and integrates simple morphological indicators with advanced, (immuno)-histochemical markers. This guide also characterizes human HF cycling in xenografts and highlights the utility of this model for in vivo hair research. Detailed schematic drawings and representative micrographs provide examples of how best to identify human HF stages, even in suboptimally sectioned tissue, and practical recommendations are given for designing human-on-mouse hair cycle experiments. Thus, this guide seeks to offer a benchmark for human hair cycle stage classification, for both hair research experts and newcomers to the field.

  20. Immunotherapy of Malignancy by in vivo Gene Transfer into Tumors

    NASA Astrophysics Data System (ADS)

    Plautz, Gregory E.; Yang, Zhi-Yong; Wu, Bei-Yue; Gao, Xiang; Huang, Leaf; Nabel, Gary J.

    1993-05-01

    The immune system confers protection against a variety of pathogens and contributes to the surveillance and destruction of neoplastic cells. Several cell types participate in the recognition and lysis of tumors, and appropriate immune stimulation provides therapeutic effects in malignancy. Foreign major histocompatibility complex (MHC) proteins also serve as a potent stimulus to the immune system. In this report, a foreign MHC gene was introduced directly into malignant tumors in vivo in an effort to stimulate tumor rejection. In contrast to previous attempts to induce tumor immunity by cell-mediated gene transfer, the recombinant gene was introduced directly into tumors in vivo. Expression of the murine class I H-2K^s gene within the CT26 mouse colon adenocarcinoma (H-2K^d) or the MCA 106 fibrosarcoma (H-2K^b) induced a cytotoxic T-cell response to H-2K^s and, more importantly, to other antigens present on unmodified tumor cells. This immune response attenuated tumor growth and caused complete tumor regression in many cases. Direct gene transfer in vivo can therefore induce cell-mediated immunity against specific gene products, which provides an immunotherapeutic effect for malignancy, and potentially can be applied to the treatment of cancer and infectious diseases in man.

  1. Systemic Inhibition of CREB is Well-tolerated in vivo

    PubMed Central

    Li, Bingbing X.; Gardner, Ryan; Xue, Changhui; Qian, David Z.; Xie, Fuchun; Thomas, George; Kazmierczak, Steven C.; Habecker, Beth A.; Xiao, Xiangshu

    2016-01-01

    cAMP-response element binding protein (CREB) is a nuclear transcription factor activated by multiple extracellular signals including growth factors and hormones. These extracellular cues activate CREB through phosphorylation at Ser133 by various protein serine/threonine kinases. Once phosphorylated, it promotes its association with transcription coactivators CREB-binding protein (CBP) and its paralog p300 to activate CREB-dependent gene transcription. Tumor tissues of different origins have been shown to present overexpression and/or overactivation of CREB, indicating CREB as a potential cancer drug target. We previously identified 666-15 as a potent inhibitor of CREB with efficacious anti-cancer activity both in vitro and in vivo. Herein, we investigated the specificity of 666-15 and evaluated its potential in vivo toxicity. We found that 666-15 was fairly selective in inhibiting CREB. 666-15 was also found to be readily bioavailable to achieve pharmacologically relevant concentrations for CREB inhibition. Furthermore, the mice treated with 666-15 showed no evidence of changes in body weight, complete blood count, blood chemistry profile, cardiac contractility and tissue histologies from liver, kidney and heart. For the first time, these results demonstrate that pharmacological inhibition of CREB is well-tolerated in vivo and indicate that such inhibitors should be promising cancer therapeutics. PMID:27694829

  2. In vivo histamine voltammetry in the mouse premammillary nucleus.

    PubMed

    Samaranayake, Srimal; Abdalla, Aya; Robke, Rhiannon; Wood, Kevin M; Zeqja, Anisa; Hashemi, Parastoo

    2015-06-01

    Histamine plays a major role in the mediation of allergic reactions such as peripheral inflammation. This classical monoamine is also a neurotransmitter involved in the central nervous system but its role in this context is poorly understood. Studying histamine neurotransmission is important due to its implications in many neurological disorders. The sensitivity, selectivity and high temporal resolution of fast scan cyclic voltammetry (FSCV) offer many advantages for studying electroactive neurotransmitters. Histamine has previously been studied with FSCV; however, the lack of a robust Faradaic electrochemical signal makes it difficult to selectively identify histamine in complex media, as found in vivo. In this work, we optimize an electrochemical waveform that provides a stimulation-locked and unique electrochemical signal towards histamine. We describe in vitro waveform optimization and a novel in vivo physiological model for stimulating histamine release in the mouse premammillary nucleus via stimulation of the medial forebrain bundle. We demonstrate that a robust signal can be used to effectively identify histamine and characterize its in vivo kinetics.

  3. Gene transfer into mammalian somatic cells in vivo.

    PubMed

    Yang, N S

    1992-01-01

    Direct gene transfer into mammalian somatic tissues in vivo is a developing technology with potential application for human gene therapy. During the past 2 years, extensive progress and numerous breakthroughs have been made in this area of research. Genetically engineered retroviral vectors have been used successfully to infect live animals, effecting foreign gene expression in liver, blood vessels, and mammary tissues. Recombinant adenovirus and herpes simplex virus vectors have been utilized effectively for in vivo gene transfer into lung and brain tissues, respectively. Direct injection or particle bombardment of DNA has been demonstrated to provide a physical means for in situ gene transfer, while carrier-mediated DNA delivery techniques have been extended to target specific organs for gene expression. These technological developments in conjunction with the initiation of the NIH human gene therapy trials have marked a milestone in developing new medical treatments for various genetic diseases and cancer. Various in vivo gene transfer techniques should also provide new tools for basic research in molecular and developmental genetics.

  4. Metabolism of nanomaterials in vivo: blood circulation and organ clearance.

    PubMed

    Wang, Bing; He, Xiao; Zhang, Zhiyong; Zhao, Yuliang; Feng, Weiyue

    2013-03-19

    Before researchers apply nanomaterials (NMs) in biomedicine, they need to understand the blood circulation and clearance profile of these materials in vivo. These qualities determine the balance between nanomaterial-induced activity and unwanted toxicity. NMs have heterogeneous characteristics: they combine the bulk properties of solids with the mobility of molecules, and their highly active contact interfaces exhibit diverse functionalities. Any new and unexpected circulation features and clearance patterns are of great concern in toxicological studies and pharmaceutical screens. A number of studies have reported that NMs can enter the bloodstream directly during their application or indirectly via inhalation, ingestion, and dermal exposure. Due to the small size of NMs, the blood can then transport them throughout the circulation and to many organs where they can be stored. In this Account, we discuss the blood circulation and organ clearance patterns of NMs in the lung, liver, and kidney. The circulation of NMs in bloodstream is critical for delivery of inhalable NMs to extrapulmonary organs, the delivery of injectable NMs, the dynamics of tissue redistribution, and the overall targeting of drug carriers to specific cells and organs. The lung, liver, and kidney are the major distribution sites and target organs for NMs exposure, and the clearance patterns of NMs in these organs are critical for understanding the in vivo fate of NMs. Current studies suggest that multiple factors control the circulation and organ clearance of NMs. The size, shape, surface charge, surface functional groups, and aspect ratio of NMs as well as tissue microstructures strongly influence the circulation of NMs in bloodstream, their site-specific extravasation, and their clearance profiles within organs. Therefore structure design and surface modification can improve biocompatibility, regulate the in vivo metabolism, and reduce the toxicity of NMs. The biophysicochemical interactions

  5. EPID based in vivo dosimetry system: clinical experience and results.

    PubMed

    Celi, Sofia; Costa, Emilie; Wessels, Claas; Mazal, Alejandro; Fourquet, Alain; Francois, Pascal

    2016-01-01

    Mandatory in several countries, in vivo dosimetry has been recognized as one of the next milestones in radiation oncology. Our department has implemented clinically an EPID based in vivo dosimetry system, EPIgray, by DOSISOFT S.A., since 2006. An analysis of the measurements per linac and energy over a two-year period was performed, which included a more detailed examination per technique and treat-ment site over a six-month period. A comparison of the treatment planning system doses and the doses estimated by EPIgray shows a mean of the differences of 1.9% (± 5.2%) for the two-year period. The 3D conformal treatment plans had a mean dose difference of 2.0% (± 4.9%), while for intensity-modulated radiotherapy and volumetric-modulated arc therapy treatments the mean dose difference was -3.0 (± 5.3%) and -2.5 (± 5.2%), respectively. In addition, root cause analyses were conducted on the in vivo dosimetry measurements of two breast cancer treatment techniques, as well as prostate treatments with intensity-modulated radiotherapy and volumetric-modulated arc therapy. During the breast study, the dose differences of breast treatments in supine position were correlated to patient setup and EPID positioning errors. Based on these observations, an automatic image shift correc-tion algorithm is developed by DOSIsoft S.A. The prostate study revealed that beams and arcs with out-of-tolerance in vivo dosimetry results tend to have more complex modulation and a lower exposure of the points of interest. The statistical studies indicate that in vivo dosimetry with EPIgray has been successfully imple-mented for classical and complex techniques in clinical routine at our institution. The additional breast and prostate studies exhibit the prospects of EPIgray as an easy supplementary quality assurance tool. The validation, the automatization, and the reduction of false-positive results represent an important step toward adaptive radiotherapy with EPIgray. PMID:27167283

  6. Die neue Kosmologie. Von Dunkelmaterie, GUTs und Superhaufen.

    NASA Astrophysics Data System (ADS)

    Cornell, J.

    This book is a German translation, by M. Röser, of the American original "Bubbles, voids, and bumps in time: the new cosmology", published 1989 (see 49.003.045). Contents: 1. Die Entdeckung des Weltalls: Eine Einleitung (A. P. Lightman). 2. Die Vermessung des Weltalls: Rotverschiebungen und Standardkerzen (R. P. Kirshner). 3. Die Kartierung des Weltalls: Scheiben und Blasen (M. J. Geller). 4. Die Bestimmung der Masse im Weltall: Dunkelmaterie und fehlende Masse (V. C. Rubin). 5. Der Beginn des Weltalls: Urknall und kosmische Inflation (A. H. Guth). 6. Die Ausweitung des Weltalls: Das Weltraumteleskop und Perspektiven für die nächsten 20 Jahre (J. E. Gunn).

  7. Prediction of In Vivo Radiation Dose Status in Radiotherapy Patients using Ex Vivo and In Vivo Gene Expression Signatures

    PubMed Central

    Paul, Sunirmal; Barker, Christopher A.; Turner, Helen C.; McLane, Amanda; Wolden, Suzanne L.; Amundson, Sally A.

    2011-01-01

    After a large-scale nuclear accident or an attack with an improvised nuclear device, rapid biodosimetry would be needed for triage. As a possible means to address this need, we previously defined a gene expression signature in human peripheral white blood cells irradiated ex vivo that predicts the level of radiation exposure with high accuracy. We now demonstrate this principle in vivo using blood from patients receiving total-body irradiation (TBI). Whole genome microarray analysis has identified genes responding significantly to in vivo radiation exposure in peripheral blood. A 3-nearest neighbor classifier built from the TBI patient data correctly predicted samples as exposed to 0, 1.25 or 3.75 Gy with 94% accuracy (P < 0.001) even when samples from healthy donor controls were included. The same samples were classified with 98% accuracy using a signature previously defined from ex vivo irradiation data. The samples could also be classified as exposed or not exposed with 100% accuracy. The demonstration that ex vivo irradiation is an appropriate model that can provide meaningful prediction of in vivo exposure levels, and that the signatures are robust across diverse disease states and independent sample sets, is an important advance in the application of gene expression for biodosimetry. PMID:21388269

  8. Photo-cross-linked poly(ethylene carbonate) elastomers: synthesis, in vivo degradation, and determination of in vivo degradation mechanism.

    PubMed

    Cornacchione, L A; Qi, B; Bianco, J; Zhou, Z; Amsden, B G

    2012-10-01

    Low-molecular-weight poly(ethylene carbonate) diols of varying molecular weight were generated through catalyzed thermal degradation of high-molecular-weight poly(ethylene carbonate). These polymers were then end functionalized with acrylate groups. The resulting α,ω-diacrylates were effectively photo-cross-linked upon exposure to long-wave UV light in the presence of a photoinitiator to yield rubbery networks of low sol content. The degree of cross-linking effectively controlled the in vivo degradation rate of the networks by adherent macrophages; higher cross-link densities yielded slower degradation rates. The cross-link density did not affect the number of adherent macrophages at the elastomer/tissue interface, indicating that cross-linking affected the susceptibility of the elastomer to degradative species released by the macrophages. The reactive species likely responsible for in vivo degradation appears to be superoxide anion, as the in vivo results were in agreement with in vitro degradation via superoxide anion, while cholesterol esterase, known to degrade similar poly(alkylene carbonate)s, had no affect on elastomer degradation.

  9. Photo-cross-linked poly(ethylene carbonate) elastomers: synthesis, in vivo degradation, and determination of in vivo degradation mechanism.

    PubMed

    Cornacchione, L A; Qi, B; Bianco, J; Zhou, Z; Amsden, B G

    2012-10-01

    Low-molecular-weight poly(ethylene carbonate) diols of varying molecular weight were generated through catalyzed thermal degradation of high-molecular-weight poly(ethylene carbonate). These polymers were then end functionalized with acrylate groups. The resulting α,ω-diacrylates were effectively photo-cross-linked upon exposure to long-wave UV light in the presence of a photoinitiator to yield rubbery networks of low sol content. The degree of cross-linking effectively controlled the in vivo degradation rate of the networks by adherent macrophages; higher cross-link densities yielded slower degradation rates. The cross-link density did not affect the number of adherent macrophages at the elastomer/tissue interface, indicating that cross-linking affected the susceptibility of the elastomer to degradative species released by the macrophages. The reactive species likely responsible for in vivo degradation appears to be superoxide anion, as the in vivo results were in agreement with in vitro degradation via superoxide anion, while cholesterol esterase, known to degrade similar poly(alkylene carbonate)s, had no affect on elastomer degradation. PMID:22920572

  10. [Anguish about death and fear of dying, supportive care for the dying].

    PubMed

    Bouregba, A; Lebret, T

    2008-11-01

    During metastatic patient follow up, anguish about death is different from the fear of dying. In fact anguish is unconscious and associated with anxiety, on the other hand the fear of dying is a reaction to the threat of imminent death. Physical pain and isolation are factors that increase the pangs of death. The support of friends and family constitutes a real benefit for the treatment of patients during this period.

  11. In Vivo Monitoring Program Manual, PNL-MA-574, Rev 5.1

    SciTech Connect

    Lynch, Timothy P.

    2011-09-12

    The following sections provide an overview of the administration for the In Vivo Monitoring Program (IVMP) for Hanford. This includes the organizational structure and program responsibilities; coordination of in vivo measurements; scheduling measurements; performing measurements; reporting results; and quality assurance.

  12. A comparison of in vivo and in vitro methods for determining availability of iron from meals

    SciTech Connect

    Schricker, B.R.; Miller, D.D.; Rasmussen, R.R.; Van Campen, D.

    1981-01-01

    A comparison is made between in vitro and human and rat in vivo methods for estimating food iron availability. Complex meals formulated to replicate meals used by Cook and Monsen (Am J Clin Nutr 1976;29:859) in human iron availability trials were used in the comparison. The meals were prepared by substituting pork, fish, cheese, egg, liver, or chicken for beef in two basic test meals and were evaluated for iron availability using in vitro and rat in vivo methods. When the criterion for comparison was the ability to show statistically significant differences between iron availability in the various meals, there was substantial agreement between the in vitro and human in vivo methods. There was less agreement between the human in vivo and the rat in vivo and between the in vivo and the rat in vivo and between the in vitro and the rat in vivo methods. Correlation analysis indicated significant agreement between in vitro and human in vivo methods. Correlation between the rat in vivo and human in vivo methods were also significant but correlations between the in vitro and rat in vivo methods were less significant and, in some cases, not significant. The comparison supports the contention that the in vitro method allows a rapid, inexpensive, and accurate estimation of nonheme iron availability in complex meals.

  13. Spiritual aspects of death and dying.

    PubMed Central

    Mermann, A. C.

    1992-01-01

    Dying is an event beyond our comprehension, an experience that can only be imagined. Patients with cancer have a gift denied many others: some time to prepare for the approaching end of life. This time can be used to bring old conflicts to a close, to say goodbye and seek forgiveness from others, to express love and gratitude for the gifts of a life. Physicians can help patients by being aware of the spiritual dimensions to life that many patients have. In major religious traditions, death is accepted as the natural end of the gift of life and as a point of transition to another, yet unknown, existence. For many patients, it is not death that is feared, but abandonment. The physician's awareness of the spiritual needs of patients can make care of the dying more rewarding and fulfilling for all concerned. PMID:1519377

  14. Architecture for on-die interconnect

    DOEpatents

    Khare, Surhud; More, Ankit; Somasekhar, Dinesh; Dunning, David S.

    2016-03-15

    In an embodiment, an apparatus includes: a plurality of islands configured on a semiconductor die, each of the plurality of islands having a plurality of cores; and a plurality of network switches configured on the semiconductor die and each associated with one of the plurality of islands, where each network switch includes a plurality of output ports, a first set of the output ports are each to couple to the associated network switch of an island via a point-to-point interconnect and a second set of the output ports are each to couple to the associated network switches of a plurality of islands via a point-to-multipoint interconnect. Other embodiments are described and claimed.

  15. Fatigue of die cast zinc alloys

    SciTech Connect

    Schrems, K.K.; Dogan, O.N.; Goodwin, F.E.

    2006-04-01

    The rotating bending fatigue limit of die cast zinc alloy 2, alloy 3, alloy 5, AcuZinc 5, and ZA-8 were determined as a part of an on-going program by ILZRO into the mechanical properties of die cast zinc. The stress-life (S-N) curves of alloys 3, 5, AcuZinc 5, and ZA-8 were determined previously. This presentation reports the results of the S-N curve for Alloy 2 and the calculated fatigue limits for all five alloys. During the previous stress-life testing, the samples were stopped at 10 million cycles and the fatigue limit for alloy 3, alloy 5, and AcuZinc 5 appeared to be higher and the fatigue limit for ZA-8 appeared to be lower than the values reported in the literature. This was further investigated in alloy 5 and ZA-8 by testing continuous cast bulk alloy 5 and ZA-8.

  16. Spiritual aspects of death and dying.

    PubMed

    Mermann, A C

    1992-01-01

    Dying is an event beyond our comprehension, an experience that can only be imagined. Patients with cancer have a gift denied many others: some time to prepare for the approaching end of life. This time can be used to bring old conflicts to a close, to say goodbye and seek forgiveness from others, to express love and gratitude for the gifts of a life. Physicians can help patients by being aware of the spiritual dimensions to life that many patients have. In major religious traditions, death is accepted as the natural end of the gift of life and as a point of transition to another, yet unknown, existence. For many patients, it is not death that is feared, but abandonment. The physician's awareness of the spiritual needs of patients can make care of the dying more rewarding and fulfilling for all concerned.

  17. Dying in hospital: the residents' viewpoint

    PubMed Central

    Ahmedzai, S

    1982-01-01

    A survey of residents' (junior house officers') experiences and attitudes to the terminal care part of their work in four Glasgow teaching hospitals showed that even a month after starting work one-fifth of the respondents had not actively managed a dying patient. Sixty-four per cent thought that they had received inadequate teaching in terminal care. Depression and anxiety had been the most difficult symptoms encountered. The residents thought that the ward nursing staff contributed much more than their senior medical colleagues to both the medical and psychological aspects of terminal care. The results indicate a need for more undergraduate education in the most relevant areas, such as coping with the psychological problems of dying patients and their relatives. Newly qualified residents require more support from senior medical staff in looking after the terminally ill. PMID:6809204

  18. Historical review of die drool phenomenon during plastics extrusion

    NASA Astrophysics Data System (ADS)

    Musil, Jan; Zatloukal, Martin

    2013-04-01

    Die drool phenomenon is defined as unwanted spontaneous accumulation of extruded polymer melt on open faces of extrusion die during extrusion process. Such accumulated material builds up on the die exit and frequently or continually sticks onto the extruded product and thus damages it. Since die drool appears, extrusion process must be shut down and die exit must be manually cleaned which is time and money consuming. Although die drool is complex phenomenon and its formation mechanism is not fully understood yet, variety of proposed explanations of its formation mechanism and also many ways to its elimination can be found in open literature. Our review presents in historical order breakthrough works in the field of die drool research, shows many ways to suppress it, introduces methods for its quantitative evaluation and composition analysis and summarizes theories of die drool formation mechanism which can be helpful for extrusion experts.

  19. Einführung in die Astronomie.

    NASA Astrophysics Data System (ADS)

    Winnenburg, W.

    Contents: 1. Forschungbereich Astronomie. 2. Astronomische Beobachtungstechnik. 3. Bewegungen am Sternenhimmel. 4. Dynamik im Planetensystem. 5. Aufbau des Planetensystems. 6. Die Sonne. 7. Meßbare Eigenschaften der Sterne. 8. Aufbau von Sternen. 9. Veränderliche Sterne und Sonderfälle. 10. Der interstellare Raum. 11. Ko-Evolution von Sternen und Materie. 12. Astronomische Entfernungsbestimmung. 13. Milchstraßensystem. 14. Extragalaktische Systeme. 15. Das Weltall. 16. Grenzfragen.

  20. Euthanasia: why people want to die earlier.

    PubMed

    Seale, C; Addington-Hall, J

    1994-09-01

    The results from two surveys in England of relatives and others who knew people in samples drawn from death certificates are reported. The main focus is on a sample of 3696 people dying in 1990 in 20 health authorities, with supporting analysis from an earlier national sample of 639 people dying in 1987. The incidence of people saying they wanted to die sooner, and of requests for euthanasia are reported. Excluding a proportion who did not wish to express a view, or did not know the answer, about a quarter of both respondents and the people who died expressed the view that an earlier death would be, or would have been, preferable. 3.6% of people in the 1990 study were said to have asked for euthanasia at some point in the last year of life. The extent to which such views were determined by the experience of pain, other distressing symptoms, dependency and social and cultural factors such as religious belief and social class is explored. The finding that dependency was important in causing the feeling that an earlier death would have been better, as well as requests for euthanasia, is related to the public debate about euthanasia, which often contains the assertion that fear of pain is a dominant factor. Pain was found to be a significant factor in death from cancer, but not as important for other causes of death. Social class, place of residence of the deceased, and strength and type of religious faith were found to be largely insignificant in influencing feelings about an earlier death and requests for euthanasia.