Home About us Contact
|
Home About us Contact | ||
|
|
||
Vivo Imaging (vivo + imaging)
Selected AbstractsFluorescent Polystyrene,Fe3O4 Composite Nanospheres for In Vivo Imaging and HyperthermiaADVANCED MATERIALS, Issue 21 2009Donglu Shi Quantum dots (QDs) are immobilized on the surfaces of magnetic Fe3O4 -composite nanospheres (MNSs, see figure). The QDs exhibit intense visible-light emission in fluorescence spectroscopy and successfully facilitate, for the first time, in vivo soft-tissue imaging in live mice. The Fe3O4 nanoparticles respond to an external magnetic field by increasing the temperature of the surrounding environment (i.e., hyperthermia), which can be used therapeutically. [source] Sodium-Ion-Selective Two-Photon Fluorescent Probe for In Vivo Imaging,ANGEWANDTE CHEMIE, Issue 2 2010Kyung Kim Zwei Photonen sind besser als eines: Eine Zweiphotonensonde (ANa1, siehe Bild) in Zellen reagiert auf Na+ mit einer starken Zweiphotonenfluoreszenzverstärkung und einer Dissoziationskonstante Kdi von (26±2),mM. Sie lässt sich einfach in Zellen einführen und weist über lange Zeit selektiv intrazelluläres freies Na+ in lebenden Zellen und Geweben in einer Tiefe von 100,200,,m nach. [source] In Vivo Imaging of a Bacterial Cell Division Protein Using a Protease-Assisted Small-Molecule Labeling ApproachCHEMBIOCHEM, Issue 5 2008Souvik Chattopadhaya Announce on entry: We present a method for the site-specific labeling of target proteins using a set of cell permeable small-molecule probes. The tobacco etch virus (TEV) NIa protease, was used to generate target proteins with an N-terminal cysteine residue, which was subsequently labeled with thioester probe(s) in a site-specific and covalent manner. Furthermore, we demonstrate the utility of this approach for the study of FtsZ, an important bacterial cell-division protein (see figure). [source] An Albumin-Activated Far-Red Fluorochrome for In,Vivo ImagingCHEMMEDCHEM, Issue 1 2006Xavier Montet Dr. The far-red indocyanine fluorochrome VM315 significantly increases its fluorescence upon binding albumin, but not other proteins. Experimental tumor detection in multiple xenograft cancer models is greatly improved. This small-molecule probe is expected to find wide-spread application in the in,vivo fluorescence imaging of various disease processes. [source] Dopamine Transporter in vitro Binding and in vivo Imaging in the BrainBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 6 2001Kim A. Bergström Recent findings indicate that dopamine reuptake is more like a highly regulated than a constitutive determinant of dopamine clearance. Positron emission tomography (PET) and single-photon emission tomography (SPET) offer unique methods to study dopamine transporter function. Results from in vivo PET and SPET studies correspond well with in vitro studies performed on post mortem human brain tissue. Considering some of the variances between in vitro and in vivo receptor binding phenomena it may be that the role of a compound to alter binding to monoamine uptake sites in vitro does not indicate its potential to affect monoamine transporters after administration in vivo. This discrepancy may be better understood taking into account recent studies indicating the possibility of a rapid regulation of transporter function and surface expression. Furthermore, the dopamine transporter is a fruitful target for CNS drug discovery. Fundamental nature of drug actions in vivo may be studied using demonstrated in vitro and in vivo imaging methods. [source] One-Step Synthesis of 2-Arylbenzothiazole ("BTA") and -benzoxazole Precursors for in vivo Imaging of ,-Amyloid Plaques.CHEMINFORM, Issue 24 2005David Alagille Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Characterization of a C(6) Nucleoside Analogue for the in vivo Imaging of the Gene Expression of Herpes Simplex Virus Type-1 Thymidine Kinase (HSV1 TK)CHEMISTRY & BIODIVERSITY, Issue 3 2006Anass Johayem Abstract The synthesis and biological evaluation of ,6-(1,3-dihydroxyisobutyl)thymine' (DHBT; 1), which corresponds to 6-[3-hydroxy-2-(hydroxymethyl)propyl]-5-methylpyrimidine-2,4(1H,3H)-dione, is reported. DHBT (1) was designed as a new substrate for herpes simplex virus type-1 thymidine kinase (HSV1 TK). The compound was found to be exclusively phosphorylated by HSV1 TK, and to exhibit good binding affinity (Ki,=,35.3±1.3,,M). Cell-proliferation assays with HSV1-TK-transduced human osteosarcoma cells (143B-TK+-HSV1-WT) and with both human-thymidine-kinase-1-negative (143B-TK,) and non-transduced parental (MG-63) cells indicate that 1 is less cytotoxic than the standard drug Ganciclovir. Thus, DHBT (1) represents a promising precursor of a nontoxic reporter probe for the monitoring of HSV1 TK gene expression by means of positron-emission tomography (PET). [source] Fluorescence lifetime imaging of activatable target specific molecular probesCONTRAST MEDIA & MOLECULAR IMAGING, Issue 1 2010Raphael Alford Abstract In vivo optical imaging using fluorescently labeled self-quenched monoclonal antibodies, activated through binding and internalization within target cells, results in excellent target-to-background ratios. We hypothesized that these molecular probes could be utilized to accurately report on cellular internalization with fluorescence lifetime imaging (FLI). Two imaging probes were synthesized, consisting of the antibody trastuzumab (targeting HER2/neu) conjugated to Alexa Fluor750 in ratios of either 1:8 or 1:1. Fluorescence intensity and lifetime of each conjugate were initially determined at endosomal pHs. Since the 1:8 conjugate is self-quenched, the fluorescence lifetime of each probe was also determined after exposure to the known dequencher SDS. In vitro imaging experiments were performed using 3T3/HER2+ and BALB/3T3 (HER2,) cell lines. Changes in fluorescence lifetime correlated with temperature- and time-dependent cellular internalization. In vivo imaging studies in mice with dual flank tumors [3T3/HER2+ and BALB/3T3 (HER2,)] detected a minimal difference in FLI. In conclusion, fluorescence lifetime imaging monitors the internalization of target-specific activatable antibody,fluorophore conjugates in vitro. Challenges remain in adapting this methodology to in vivo imaging. Copyright © 2010 John Wiley & Sons, Ltd. [source] Progressive neurogenesis defines lateralis somatotopyDEVELOPMENTAL DYNAMICS, Issue 7 2010Jesús Pujol-Martí Abstract Fishes and amphibians localize hydromechanical variations along their bodies using the lateral-line sensory system. This is possible because the spatial distribution of neuromasts is represented in the hindbrain by a somatotopic organization of the lateralis afferent neurons' central projections. The mechanisms that establish lateralis somatotopy are not known. Using BAPTI and neuronal tracing in the zebrafish, we demonstrate growth anisotropy of the posterior lateralis ganglion. We characterized a new transgenic line for in vivo imaging to show that although peripheral growth-cone structure adumbrates somatotopy, the order of neurogenesis represents a more accurate predictor of the position of a neuron's central axon along the somatotopic axis in the hindbrain. We conclude that progressive neurogenesis defines lateralis somatotopy. Developmental Dynamics 239:1919,1930, 2010. © 2010 Wiley-Liss, Inc. [source] In Vitro Two-Dimensional Echocardiographic Imaging of a Stented Porcine Bioprosthetic Valve: The Bent Strut ArtifactECHOCARDIOGRAPHY, Issue 1 2009David S. Bach M.D.Article first published online: 8 OCT 200 Background: Echocardiographic imaging of a stented valve bioprosthesis can reveal apparent inward deflection of one or more struts. It could be assumed that this finding is related to actual strut distortion as opposed to an artifact of off-axis imaging. Objective: To determine whether normal (nondistorted) bioprosthetic struts can appear by artifact to be bent inward on two-dimensional echocardiographic imaging. Methods: A production-quality porcine bioprosthetic aortic valve was imaged in vitro using standard two-dimensional echocardiographic techniques. Apparent strut distortion on echocardiographic imaging was investigated relative to prosthesis orientation to the transducer. Results: The appearance of inward strut distortion was produced when two of three struts were simultaneously imaged, including imaging in an off-axis long axis orientation and from above or below the prosthesis. Conclusion: Apparent inward distortion of bioprosthetic struts can be simulated in vitro using a normal, nondistorted valve, and is common if two struts are simultaneously imaged. A finding of inward distortion of strut tips on in vivo imaging should be used with caution, since the finding may not be representative of actual strut anatomy. [source] The structure and mode of action of different botulinum toxinsEUROPEAN JOURNAL OF NEUROLOGY, Issue 2006J. O. Dolly The seven serotypes (A,G) of botulinum neurotoxin (BoNT) are proteins produced by Clostridium botulinum and have multifunctional abilities: (i) they target cholinergic nerve endings via binding to ecto-acceptors (ii) they undergo endocytosis/translocation and (iii) their light chains act intraneuronally to block acetylcholine release. The fundamental process of quantal transmitter release occurs by Ca2+ -regulated exocytosis involving sensitive factor attachment protein-25 (SNAP-25), syntaxin and synaptobrevin. Proteolytic cleavage by BoNT-A of nine amino acids from the C-terminal of SNAP-25 disables its function, causing prolonged muscle weakness. This unique combination of activities underlies the effectiveness of BoNT-A haemagglutinin complex in treating human conditions resulting from hyperactivity at peripheral cholinergic nerve endings. In vivo imaging and immunomicroscopy of murine muscles injected with type A toxin revealed that the extended duration of action results from the longevity of its protease, persistence of the cleaved SNAP-25 and a protracted time course for the remodelling of treated nerve,muscle synapses. In addition, an application in pain management has been indicated by the ability of BoNT to inhibit neuropeptide release from nociceptors, thereby blocking central and peripheral pain sensitization processes. The widespread cellular distribution of SNAP-25 and the diversity of the toxin's neuronal acceptors are being exploited for other therapeutic applications. [source] Integrated Multifunctional Nanosystems for Medical Diagnosis and TreatmentADVANCED FUNCTIONAL MATERIALS, Issue 21 2009*Article first published online: 9 OCT 200, Donglu Shi Abstract This article provides an overview on the development of integrated multifunctional nanosystems for medical diagnosis and treatment. In particular, a novel system is developed specifically for achieving simultaneous diagnosis and treatment of cancer. Critical issues are addressed on the architecture and assembly of nanocomponents based on medical requirements: targeted in vivo imaging, controlled drug release, localized hyperthermia, and toxicity. Nanotube-based carriers are summarized with surface functionalized properties. Other types of nanocarriers are also included such as super paramagnetic composite nanospheres and biodegradable hydroxylapatite nanoparticles. In addition, polymeric-based nanosystems are introduced with several novel features: they can be bio-dissolved due to environmental pH and temperature fluctuations. The nanocarriers are surface tailored with key functionalities: surface antibodies for cell targeting, anti-cancer drug loading, and magnetic nanoparticles for both hyperthermia and MRI. Future requirements, aims, and trends in the development of multifunctional nanosystems, particularly with intelligent functionalities for fundamental studies, are also provided. [source] Inducible gene expression with the Tet-on system in CD4+ T cells and thymocytes of miceGENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 7 2007Jisen Huai Abstract CD4+ T cells with their growing list of effector and regulatory subpopulations have vital functions within the immunohematopoietic system. We report here on the first mouse lines that allow temporally and quantitatively controlled expression of transgenes specifically in CD4+ thymocytes and T cells. These were constructed using the Tet-on system. The rtTA2S -M2 version of the reverse tetracycline-dependent transactivator was placed under control of all known CD4 regulatory elements. Reporter transgene expression in mice expressing these constructs is highly specific for CD4+ cells, is strictly dependent on the tetracycline derivative doxycycline, and can be regulated by up to five logs depending on the doxycycline concentration. Moreover, we demonstrate that these mice can be used for noninvasive in vivo imaging of a coexpressed luciferase reporter. These new mouse lines should be highly valuable for studying and manipulating numerous aspects of CD4+ T cell development, biology, and function. genesis 45:427,431, 2007. © 2007 Wiley-Liss, Inc. [source] Low dose radiotherapy in indolent lymphomas, enough is enough,HEMATOLOGICAL ONCOLOGY, Issue 2 2009R. L. M. Haas MD. Abstract Follicular lymphomas, as a prototype of all indolent lymphomas, are exquisitely radiation sensitive. This review paper highlights the clinical presentation of this lymphoma entity. Literature data are presented on first line curative irradiation in stage I and II patients, low-dose total body irradiation (TBI) in stage III and IV patients in first line and low-dose IF-RT (involved field radiotherapy) in patients with relapse. The clinical aspects of 2,×,2,Gy IF-RT in follicular lymphoma (FL) are presented as well as the in vivo imaging of the apoptotic cell death underlying the clinical response. Finally, by gene expression profiling, possible molecular-biological pathways are described involved in the low dose irradiation of FL. Copyright © 2009 John Wiley & Sons, Ltd. [source] Disparity between prostate tumor interior versus peripheral vasculature in response to verteporfin-mediated vascular-targeting therapyINTERNATIONAL JOURNAL OF CANCER, Issue 3 2008Bin Chen Abstract Photodynamic therapy (PDT) is a light-based cancer treatment modality. Here we employed both in vivo and ex vivo fluorescence imaging to visualize vascular response and tumor cell survival after verteporfin-mediated PDT designed to target tumor vasculature. EGFP-MatLyLu prostate tumor cells, transduced with EGFP using lentivirus vectors, were implanted in athymic nude mice. Immediately after PDT with different doses of verteporfin, tumor-bearing animals were injected with a fluorochrome-labeled albumin. The extravasation of fluorescent albumin along with tumor EGFP fluorescence was monitored noninvasively with a whole-body fluorescence imaging system. Ex vivo fluorescence microscopy was performed on frozen sections of tumor tissues taken at different times after treatment. Both in vivo and ex vivo imaging demonstrated that vascular-targeting PDT with verteporfin significantly increased the extravasation of fluorochrome-labeled albumin in the tumor tissue, especially in the tumor periphery. Although PDT induced substantial vascular shutdown in interior blood vessels, some peripheral tumor vessels were able to maintain perfusion function up to 24 hr after treatment. As a result, viable tumor cells were typically detected in the tumor periphery in spite of extensive tumor cell death. Our results demonstrate that vascular-targeting PDT with verteporfin causes a dose- and time-dependent increase in vascular permeability and decrease in blood perfusion. However, compared to the interior blood vessels, peripheral tumor blood vessels were found less sensitive to PDT-induced vascular shutdown, which was associated with subsequent tumor recurrence in the tumor periphery. © 2008 Wiley-Liss, Inc. [source] The imaging continuum: bench to biomarkers to diagnostics,JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9-10 2007Richard A. Frank Abstract Innovation in basic and applied science has brought radiotracers to fruition as diagnostics. Non-invasive, longitudinal, and quantifiable molecular imaging is the key to diagnosing and monitoring numerous illnesses, with more to come from characterization of the clinical relevance of findings from genomics research. Radiotracers enable real-time in vivo studies of the effects of drug candidates on receptors, pathways, pharmacodynamics, and clinically relevant endpoints, thereby providing both early detection of pathophysiology to enable early intervention, and then monitoring of treatment responses to enable individualization of treatment regimens. We review developments which have translated imaging from ,bench to bedside', or ,biomarkers to diagnostics'. Notable developments include (1) synthesis methods for rapid 11C labeling of biomolecules to high specific radioactivity; (2) ligand-binding assays for screening molecular imaging agents rather than drugs; (3) in vivo imaging of radiotracers in animals; (4) discovering the imaging advantages of 99mTc, 11C, and 18F; (5) co-registration and automated quantitative assessment of high spatial resolution CT and MR images with molecular images from PET for longitudinal studies of treatment effect. Copyright © 2007 John Wiley & Sons, Ltd. [source] Efficient synthesis of [11C]befloxatone, a selective radioligand for the in vivo imaging of MAO-A density using PETJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2003F. Dollé Abstract Carbon-11 labelled befloxatone ((5R)-5-(methoxymethyl)-3-[4-[(3R)-4,4,4-trifluoro-3-hydroxybutoxy]phenyl]-2-oxazolidinone) is a reversible and selective monoamine oxidase-A (MAO-A) inhibitor and appears to be a new potent PET tracer for the in vivo imaging of MAO-A density. In this paper, the radiosynthesis of befloxatone was investigated and orientated towards the preparation of multi milliCuries of radiotracer. Typically, using no-carrier-added [11C]phosgene, 150,300 mCi (5.55,11.10 GBq) of [11C]befloxatone was obtained within 20 min of radiosynthesis (including HPLC purification) with specific radioactivities ranging from 500 to 2000 mCi/µmol (18.5,74.0 GBq/µmol). The high efficiency of these radiosyntheses allows for multi-injection protocols and kinetic approaches for absolute quantification of the tracer. Copyright © 2003 John Wiley & Sons, Ltd. [source] Highly efficient synthesis of [11C]S12968 and [11C]S12967, for the in vivo imaging of the cardiac calcium channels using PETJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 7 2001Frédéric Dolle Abstract The dihydrophyridines S12968 ((,)-S11568, absolute configuration S) and S12967 ((+)-S11568, absolute configuration R), 3-ethyl 5-methyl (,/+)-2-[(2-(2-aminoethoxy)ethoxy)methyl]-4-(2,3-dichlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate, have both an in vitro profile of high potency and of high selectivity for the low-voltage-dependent L-type calcium channel. In this paper, the radiosynthesis of both enantiomers, S12968 and S12967, with carbon-11, a positron-emitting isotope (half-life : 20.4 min) was investigated and oriented towards the preparation of multi milliCuries of radiotracer. Typically, 130,250 mCi (4.81,9.25 GBq) of [11C]S12968 and [11C]S12967 were obtained within 30 min of radiosynthesis (HPLC purification included) with specific radioactivities ranging from 500 to 1000 mCi/,mol (18.5,37.0 GBq/,mol) using no-carrier-added [11C]methyl triflate as the alkylating agent and the appropriate, enantiomerically pure carboxylic acid precursor at 100°C for 1 min. Based on preliminary PET experiments, only the levo enantiomer S12968 ((,)-[11C]-1) appears to be suitable for myocardial PET imaging as demonstrated in vivo in beagle dogs: with S12968, 85% of the uptake of [11C]S12968 could be inhibited in pretreatment experiments and up to 70% of [11C]S12968 could be displaced. Further investigations are currently underway in order to provide an absolute quantification of ventricular calcium channels with PET. Copyright © 2001 John Wiley & Sons, Ltd. [source] Spatial refractive index measurement of porcine artery using differential phase optical coherence microscopyLASERS IN SURGERY AND MEDICINE, Issue 10 2006Jeehyun Kim PhD Abstract Background and Objectives We describe a methodology to record spatial variation of refractive index of porcine renal artery using differential phase optical coherence microscopy (DP-OCM). Study Design/Materials and Methods The DP-OCM provides quantitative measurement of thin specimen phase retardation and refractive index by measuring optical path-length changes on the order of a few nanometers and with a lateral resolution of 3 µm. The DP-OCM instrumentation is an all-fiber, dual-channel Michelson interferometer constructed using a polarization maintaining (PM) fiber. Results Two-dimensional en face dual-channel phase images are taken over a 150,×,200 µm region on a microscopic slide, and the images are reconstructed by plotting a two-dimensional refractive index map as the OCM beam is moved across the sample. Conclusions Because the DP-OCM can record transient changes in the optical path-length, the system may be used to record quantitative optical path-length alterations of tissue in response to various stimuli. A fiber-based DP-OCM may have the potential to substantially improve in vivo imaging of individual cells for a variety of clinical diagnostics, and monitoring applications. Lasers Surg. Med. © 2006 Wiley-Liss, Inc. [source] Visualization of ,-amyloid plaques in a transgenic mouse model of Alzheimer's disease using MR microscopy without contrast reagentsMAGNETIC RESONANCE IN MEDICINE, Issue 3 2004Sang-Pil Lee Abstract The visualization of ,-amyloid plaque deposition in brain, a key feature of Alzheimer's disease (AD), is important for the evaluation of disease progression and the efficacy of therapeutic interventions. In this study, ,-amyloid plaques in the PS/APP transgenic mouse brain, a model of human AD pathology, were detected using MR microscopy without contrast reagents. ,-Amyloid plaques were clearly visible in the cortex, thalamus, and hippocampus of fixed brains of PS/APP mice. The distribution of plaques identified by MRI was in excellent agreement with those found in the immunohistological analysis of the same brain sections. It was also demonstrated that image contrast for ,-amyloid plaques was present in freshly excised nonfixed brains. Furthermore, the detection of ,-amyloid plaques was achieved with a scan time as short as 2 hr, approaching the scan time considered reasonable for in vivo imaging. Magn Reson Med 52:538,544, 2004. © 2004 Wiley-Liss, Inc. [source] Assessment and compensation of susceptibility artifacts in gradient echo MRI of hyperpolarized 3He gasMAGNETIC RESONANCE IN MEDICINE, Issue 2 2003Jim M. Wild Abstract The effects of macroscopic background field gradients upon 2D gradient echo images of inhaled 3He in the human lung were investigated at 1.5 T. Effective compensation of in-slice signal loss in 3He gradient echo images was then demonstrated using a multiple acquisition interleaved single gradient echo sequence. This method restores signal dephasing through a combination of separate images acquired with different slice refocusing gradients. In vivo imaging of volunteers with the sequence shows substantial restoration of signal at the lung periphery and close to blood vessels. The technique presented may be useful when using 3He MRI for volumetric measurements of lung ventilation and in studies using 3He combined with intravenous contrast as a means of assessing lung ventilation/perfusion (V/Q). Magn Reson Med 50:417,422, 2003. © 2003 Wiley-Liss, Inc. [source] In vivo imaging of the neutron capture therapy agent BSH in mice using 10B MRIMAGNETIC RESONANCE IN MEDICINE, Issue 1 2001Peter Bendel Abstract Boron neutron capture therapy (BNCT) is an experimental cancer treatment modality requiring the targeting of 10B-enriched compounds to the tumor, which is then irradiated by low-energy neutrons. One of the boron-containing compounds used for this purpose is the mercaptoborane Na2B12H11SH (BSH). The first in vivo MR images of 10B-enriched BSH are presented here. BSH, injected into the tail vein of mice with implanted M2R melanoma xenografts, was imaged using 3D gradient echo 10B MRI. 10B NMR spectroscopy, localized mainly to the tumor by virtue of the use of a small surface coil, was applied to measure the T1 (2.9 ± 0.3 ms) and T2 (1.75 ± 0.25 ms) values of the 10B signal. The MRI experiments detected levels of about 20 ppm (,g boron / g tissue) at 6 × 6 × 6 mm spatial resolution in a total scan time of 16 min. Magn Reson Med 46:13,17, 2001. © 2001 Wiley-Liss, Inc. [source] In vivo delivery of fluoresceinated dextrans to the murine growth plate: Imaging of three vascular routes by multiphoton microscopyTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2006Cornelia E. Farnum Abstract Bone elongation by endochondral ossification occurs through the differentiation cascade of chondrocytes of cartilaginous growth plates. Molecules from the systemic vasculature reach the growth plate from three different directions: epiphyseal, metaphyseal, and a ring vessel and plexus associated with the perichondrium. This study is an analysis of the real-time dynamics of entrance of fluoresceinated tracers of different molecular weights into the growth plate from the systemic vasculature and tests the hypothesis that molecular weight is a key variable in the determination of both the directionality and the extent of tracer movement into the growth plate. Multiphoton microscopy was used for direct in vivo imaging of the murine proximal tibial growth plate in anesthetized 4- to 5-week-old transgenic mice with green fluorescent protein linked to the collagen II promoter. Mice were given an intracardiac injection of either fluorescein (332.3 Da) or fluoresceinated dextrans of 3, 10, 40, 70 kDa, singly or sequentially. For each tracer, directionality and rate of arrival, together with extent of movement within the growth plate, were imaged in real time. For small molecules (up to 10 kDa), vascular access from all three directions was observed and entrance was equally permissive from the metaphyseal and the epiphyseal sides. Within our detection limit (a few percent of vascular concentration), 40 kDa and larger dextrans did not enter. These results have implications both for understanding systemic and paracrine regulation of growth plate chondrocytic differentiation, as well as variables associated with effective drug delivery to growth plate chondrocytes. © 2005 Wiley-Liss, Inc. [source] Retroviral vector-producing mesenchymal stem cells for targeted suicide cancer gene therapyTHE JOURNAL OF GENE MEDICINE, Issue 5 2009Ryosuke Uchibori Abstract Background Mesenchymal stem cells (MSCs) are a promising vehicle for targeted cancer gene therapy because of their potential of tumor tropism. For efficient therapeutic application, we developed retroviral vector-producing MSCs that enhance tumor transduction via progeny vector production. Methods Rat bone marrow-derived MSCs were nucleofected with the proviral plasmids (vesicular stomatitis virus-G protein-pseudotyped retroviral vector components) (VP-MSCs) or pLTR plasmid alone (non-VP-MSCs). The luciferase-based in vivo imaging system was used to assess gene expression periodically. To evaluate the anticancer effects, we administered MSCs expressing herpes simplex virus-thymidine kinase (HSV- tk) into the left ventricular cavity of nude mice engrafted with 9L glioma cells subcutaneously. Results In vivo imaging revealed that administration of luciferase-expressing non-VP-MSCs enhanced the bioluminescence signal at the inoculation sites of 9L cells, whereas no accumulation was observed in mice at the site of the control Rat-1 fibroblasts. Compared to non-VP-MSCs, the administration of VP-MSCs resulted in significant augmentation of the signal with an increase in transgene copy number. Immunohistochemical analysis showed marked luciferase expression at the tumor periphery in mice injected with VP-MSCs, whereas little expression was detected in those injected with non-VP-MSCs. Under the continuous infusion of ganciclovir, systemic administration of VP-MSCs expressing HSV- tk suppressed tumor growth more effectively than non-VP-MSC administration, whereas no anticancer effect was observed without ganciclovir treatment. Furthermore, VP-MSC administration caused no transgene transduction in the normal tissues and organs. Conclusions VP-MSCs accumulated at the site of tumors after intravascular injection in tumor-bearing mice, followed by in situ gene transfer to tumors without transduction of normal organs. When applied to the HSV- tk/ganciclovir suicide gene therapy, more efficient tumor growth suppression was observed using VP-MSCs compared to non-VP-MSCs. This VP-MSC-based system has great potential for improved cancer gene therapy. Copyright © 2009 John Wiley & Sons, Ltd. [source] In vivo imaging of retinoic acid receptor ,2 transcriptional activation by the histone deacetylase inhibitor MS-275 in retinoid-resistant prostate cancer cellsTHE PROSTATE, Issue 1 2005David Z. Qian Abstract BACKGROUND In retinoid resistant epithelial tumors, the lack of retinoic acid receptor ,2 (RAR,2) expression due to epigenetic silencing impairs the activation of retinoid target genes including RAR,2, and has been associated with the development of cancer. In this study we developed a strategy to monitor the re-activation of RAR,2 by chromatin remodeling agents combined with retinoids in real time, and to correlate the RAR,2 re-activation with anti-tumor activity. METHODS We selected the RAR,2-negative retinoid resistant human prostate carcinoma cell line PC3 and stably transfected it with a luciferase expression vector under the control of a functional segment of RAR,2 promoter (pGL2-RAR,2-PC3). Then, we used the bioluminescence technology to monitor the reporter gene expression in real time both in vitro and in vivo following combination treatment with the histone deacetylase inhibitor MS-275 and 13- cis retinoic acid (CRA). Based on the effective dose for the RAR,2 re-activation, we tested the anti-tumor activity of this drug combination. RESULTS Following combination treatment with MS-275 and CRA, we observed endogenous RAR,2 re-expression, acetylation at the RAR,2 promoter level, and synergistic activation of the luciferase reporter gene by real time imaging both in vitro and in vivo. Combination treatment with MS-275 and CRA restored retinoid sensitivity in human prostate carcinoma cell lines, and had a greater inhibitory effect on tumor cell growth than single agents in vitro and in vivo. CONCLUSIONS This study provides evidence that HDAC inhibitors restore retinoid sensitivity in prostate cancer cells, and in vivo real time imaging of RAR,2 activation may represent a useful tool to study the pharmacodynamics of combination therapy with HDAC inhibitors and retinoids. © 2005 Wiley-Liss, Inc. [source] Improving the Procedure for Detection of Intrahepatic Transplanted Islets by Magnetic Resonance ImagingAMERICAN JOURNAL OF TRANSPLANTATION, Issue 10 2009M. L. Malosio Islet transplantation is an effective therapy for restoring normoglycemia in type-1 diabetes, but long-term islet graft function is achieved only in a minority of cases. Noninvasive magnetic resonance imaging of pancreatic islets is an attractive option for "real-time" monitoring of graft evolution. So far, previous studies have been performed in the absence of a standardized labeling procedure and, besides a feasibility study in patients, the effectiveness and safety of various labeling approaches were tested only with high field magnets (4.7 T). In this study, we addressed: (a) standardization of a labeling procedure for human islets with clinically-approved contrast agent Endorem®, (b) safety aspects of labeling related to inflammation and (c) quality of imaging both at 7 T and 1.5 T. We have highlighted that the ratio of Endorem®/islet is crucial for reproducible labeling, with a ratio of 2.24 ug/IEQ, allowing successful in vivo imaging both with 1.5 T and 7.0 T magnets up to 143 days after intrahepatic transplant. With this standardized labeling procedure, labeled islets are neither inflamed nor more susceptible to inflammatory insults than unlabeled ones. This report represents an important contribution towards the development of a standardized and safe clinical protocol for the noninvasive imaging of transplanted islets in humans. [source] In vivo imaging of microglial cell traffickingACTA OPHTHALMOLOGICA, Issue 2009M PAQUES Purpose Microglial cells (MCs) are active sensors of neural tissues that are rapidly mobilized upon disruption of homeostasis. OUr goal was to observe in vivo the migration of MCs, which has not been done yet. Methods Following acute laser damage, the behavior of MCs in the retina of adult Cx3cr1gfp/+ and gfp/gfp mice was observed noninvasively using time-lapse confocal scanning laser ophthalmoscopy. Observation were done at various time-points up to 8 days after laser damage. Results Focal damage elicite prompt migratory response of MCs within 200 to 400 µm around laser burns. This migratory response was preceded in all case by dendritic reorientation. Convergent and nonconvergent migration were observed. Such migratory activity persisted several days after laser damage. At day 8, the microglia network was restored and microglial locomotion had ceased. Conclusion To our knowledge, this is the first observation of microglial locomotion in vivo. A Morphological evidence of microglial activation starts with dendritic reorganization. Migrating cells were only of the dendritic type (i.e. not ameboid). There appears to be a notable heterogeneity in the locomotor response of MCs. MCs within and around scars remain highly motile and mobile several days after laser damage. [source] In vivo imaging of retinal inflammation in experimental autoimmune uveoretinitisACTA OPHTHALMOLOGICA, Issue 2009Purpose Experimental animal models are essential for us to understand the pathogenesis of human diseases. Posterior uveoretinitis can be modelled in mice with IRBP immunization (i.e. experimental autoimmune uveitis, EAU), whereas a number of mouse models are also available for age-related macular degeneration (AMD). With the advancement in new technologies, it is now possible to image inflammatory retinal changes in experimental mice in vivo none invasively. The aim of the study is to clinical revisit the traditional retinal inflammation animal models with modern imaging techniques. Methods EAU was induced in C57B/6 mice with IRBP peptide 1-20. Aged CCL2 knockout mice were used as an AMD model. Retinal inflammatory changes were imaged in vivo non-invasively using topical endoscopic fundus imaging system and the scanning laser ophthalmoscopy (SLO) system. Results Inflammatory retinal changes in the early stages of EAU were characterised as retinal oedema, vascular sheathing, multiple small retinal infiltrates or large linear retinal infiltrates. "Snow-ball"-like vitreous infiltrates were observed in the inferior part of the fundus at the peak stage of EAU. Using SLO autofluorescent (AF)-macrophages were detected at the peak stages of EAU and were located predominately around inflamed retinal venules. At the late stages of EAU, retinal scars and intraretinal neovascular membranes were observed. In the retina aged CCL2 KO mice, regional retinal atrophy and dursen-like multiple lesions were observed. Dursen-like changes were autofluorescent in SLO examination. Ex vivo confocal microscopy indicated that they were not dursen but subretinal lipofuscin-loaded microglial cells. Conclusion EAU mimics many aspects of human posterior uveoretinitis including retinal vasculitis, multifocal choroiditis. Late stage EAU could be a good model for inflammation induced retinal neovascularisation. CCL2 KO mouse is a model of dry-AMD. [source] Spectral domain OCT of exudative AMDACTA OPHTHALMOLOGICA, Issue 2009N LEVEZIEL Age-related Macular Degeneration (AMD) is the main cause of vision loss in developed countries. Spectral domain OCT (SD-OCT) is a non invasive technique providing in vivo imaging of the retina, with a higher resolution than time domain OCT. This SIS will describe the clinical features of exudative AMD with SD-OCT, including occult choroidal neovascularization (CNV), classic CNV, idiopathic polypoïdal vasculopathy, and chorioretinal anastomosis. The improvement of the resolution of retinal imaging will provide a better classification and explanation of the pathological processes observed during AMD. [source] Chorioretinal anastomosis in adaptive optic and high definition spectral domain optical coherence tomographyACTA OPHTHALMOLOGICA, Issue 2009C MAILLON Purpose To assess morphologic variations in the outer and inner retinal layers in eyes with chorioretinal anatomosis using high definition Spectral Domain Optical Coherence Tomography (Spectralis HRA OCT, Heidelberg Engineering, Heidelberg, Germany) and to compare these scans with images acquired by Adaptive Optics (AO). Methods This was a prospective observational case series including 50 patients. SD-OCT scans were obtained with combined confocal scanning laser ophthalmoscope (cSLO) and SD-OCT for simultaneous tomographic and topographic in vivo imaging. Patients underwent fluorescein and ICG- angiography and Adaptive Optics assessment with Imagine EyesÔ System. The neurosensory retina and the photoreceptor layer were analyzed using both HR-OCT and AO imaging. Results Combining of the adaptive optics with SD-OCT may give us further information of the early stage development of chorioretinal anastomosis. [source] | |||||||||||||||||||