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Vivo Applications (vivo + application)
Selected AbstractsSolid Contact Micropipette Ion Selective Electrode II: Potassium Electrode for SECM and In Vivo ApplicationsELECTROANALYSIS, Issue 17-18 2009Gergely Gyetvai Abstract Micropipette ion selective electrodes are very small, but fragile, short-life time sensors with very high resistance. Their high resistance is a draw back considering application in scanning electrochemical microscopy (SECM) and in life sciences. New, low resistance potassium micropipette electrodes were prepared, and applied. The electrode contains solid internal contact made of a carbon fiber lowered down all the way close to the orifice of the micropipette. The internal contact potential was kept constant by applying a doped, electrochemically prepared PEDOT coating on the fiber surface. The electrode performed well in in vivo experiments both in plant and animal tissue without capacitance neutralization and in SECM. [source] Ex vivo Application of Carbon Monoxide in UW Solution Prevents Transplant-Induced Renal Ischemia/Reperfusion Injury in PigsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2010J. Yoshida I/R injury is a major deleterious factor of successful kidney transplantation (KTx). Carbon monoxide (CO) is an endogenous gaseous regulatory molecule, and exogenously delivered CO in low concentrations provides potent cytoprotection. This study evaluated efficacies of CO exposure to excised kidney grafts to inhibit I/R injury in the pig KTx model. Porcine kidneys were stored for 48 h in control UW or UW supplemented with CO (CO-UW) and autotransplanted in a 14-day follow-up study. In the control UW group, animal survival was 80% (4/5) with peak serum creatinine levels of 12.0 ± 5.1 mg/dL. CO-UW showed potent protection, and peak creatinine levels were reduced to 6.9 ± 1.4 mg/dL with 100% (5/5) survival without any noticeable adverse event or abnormal COHb value. Control grafts at 14 days showed significant tubular damages, focal fibrotic changes and numerous infiltrates. The CO-UW group showed significantly less severe histopathological changes with less TGF-, and p-Smad3 expression. Grafts in CO-UW also showed significantly lower early mRNA levels for proinflammatory cytokines and less lipid peroxidation. CO in UW provides significant protection against renal I/R injury in the porcine KTx model. Ex vivo exposure of kidney grafts to CO during cold storage may therefore be a safe strategy to reduce I/R injury. [source] In vivo application of mAb directed against the ,, TCR does not deplete but generates "invisible" ,, T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2009Christian Koenecke Abstract mAb targeting the ,, TCR have been used for ,, T-cell depletion with varying success. Although the depletion-capacity of the anti-,, TCR mAb clone GL3 has been disputed repeatedly, many groups continue to use ,, T-cell depletion protocols involving the mAb clone UC7-13D5 and find significant biological effects. We show here that treatment with both GL3 and UC7-13D5 antibodies does not deplete ,, T cells in vivo, but rather leads to TCR internalization and thereby generates "invisible" ,, T cells. We addressed this issue using anti-,, TCR mAb injections into WT mice as well as into reporter TCR delta locus-histone 2B enhanced GFP knock-in mice, in which ,, T cells can be detected based on an intrinsic green fluorescence. Importantly, the use of TCR delta locus-histone 2B enhanced GFP mice provided here for the first time direct evidence that the "depleted" ,, T cells were actually still present. Our results show further that GL3 and UC7-13D5 mAb are in part cross-competing for the same epitope. Assessed by activation markers, we observed in vitro and in vivo activation of ,, T cells through mAb. We conclude that ,, T-cell depletion experiments must be evaluated with caution and discuss the implications for future studies on the physiological functions of ,, T cells. [source] IL-2 induces in vivo suppression by CD4+CD25+Foxp3+ regulatory T cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 6 2008Susan Brandenburg Abstract Interleukin-2 (IL-2) treatment is currently used to enhance T cell-mediated immune responses against tumors or in viral infections. At the same time, IL-2 is essential for the peripheral homeostasis of CD4+CD25+Foxp3+ regulatory T cells (Treg). In our study, we show that IL-2 is also an important activator of Treg suppressive activity in vivo. IL-2 treatment induces Treg expansion as well as IL-10 production and increases their suppressive potential in vitro. Importantly, in vivo application of IL-2 via gene-gun vaccination using IL-2 encoding DNA plasmids (pIL-2) inhibited naive antigen-specific T cell proliferation as well as a Th1-induced delayed type hypersensitivity response. The suppressive effect can be transferred onto naive animals by Treg from IL-2-treated mice and the suppression depends on the synergistic action of IL-10 and TGF-,. These data highlight that during therapeutic treatment with IL-2 the concomitant activation of Treg may indeed counteract the intended activation of cellular immunity. [source] Applications of Sleeping Beauty transposons for nonviral gene therapyIUBMB LIFE, Issue 6 2007Hanzhong Liu Abstract Virus-based gene therapy has advanced to clinical trials; however, this approach may result in serious adverse events including oncogenesis and the possibility of triggering fatal immune responses. Nonviral gene delivery approaches have a better safety profile, but their in vivo application has been largely limited in the past due to their inefficient delivery into cells and lack of stable chromosomal integration that is necessary for long-term therapeutic benefit. However, recent advances suggest that the use of Sleeping Beauty transposons, a novel integrating nonviral vector system, are capable of achieving long-lasting therapeutic levels of transgene expression in preclinical settings. These observations and other ongoing relevant studies may unlock the therapeutic potential of nonviral gene therapy for human diseases. iubmb Life, 59: 1 - 6, 2007 [source] Modifications of the fibroblast growth factor-2 gene led to a marked enhancement in secretion and stability of the recombinant fibroblast growth factor-2 proteinJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2007Shin-Tai Chen Abstract Progress in FGF-2 gene therapy has been hampered by the difficulty in achieving therapeutic levels of FGF-2 secretion. This study tested whether the addition of BMP2/4 hybrid secretion signal to the FGF-2 gene and mutation of cys-70 and cys-88 to serine and asparagine, respectively, would increase the stability and secretion of active FGF-2 protein in mammalian cells using MLV-based vectors. Single or double mutations of cys-70 and cys-88 to ser-70 and asp-88, respectively, markedly increased the amounts of FGF-2 protein in conditioned media and cell lysates, which may be due to glycosylation, particularly at the mutated asp-88 residue. Addition of BMP2/4 secretion signal increased FGF-2 secretion, but also suppressed FGF-2 biosynthesis. The combination of BMP2/4 secretion signal and double cys-70 and cys-88 mutations increased the total amount of secreted FGF-2 protein >60-fold. The modifications did not alter its ability to stimulate cell proliferation and Erk1/2 phosphorylation in marrow stromal cells or its ability to bind heparin in vitro, suggesting that the modified FGF-2 protein was functionally as effective as the unmodified FGF-2. An ex vivo application of rat skin fibroblasts (RSF) transduced with the modified FGF-2 vector in a subcutaneous implant model showed that rats with implants containing cells transduced with the modified FGF-2 vector increased serum FGF-2 level >15-fold, increased growth of the implant, and increased vascularization within the implant, compared to rats that received implants containing ,-galactosidase- or wild-type FGF-2-transduced control cells. This modified vector may be useful in FGF-2 gene therapy investigations. J. Cell. Biochem. 100: 1493,1508, 2007. © 2007 Wiley-Liss, Inc. [source] Feasibility of Myxomatous Mitral Valve Repair Using Direct Leaflet and Chordal Radiofrequency AblationJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 6 2008JEFFREY L. WILLIAMS M.D., M.S. Objective: Minimally invasive repair of mitral valve prolapse (MVP) causing severe mitral regurgitation (MR) should reduce MR and have chronic durability. Our ex vivo, acute in vivo, and chronic in vivo studies suggest that direct application of radiofrequency ablation (RFA) to mitral leaflets and chordae can effect these repair goals to decrease MR. Methods: A total of seven canines were studied to assess the effects of RFA on mitral valve structure and function. RFA was applied ex vivo (n = 1), acutely in vivo using a right lateral thoracotomy and cardiopulmonary bypass (n = 3), and chronically in vivo using percutaneous access to the heart (n = 3). RFA was applied to the mitral valve and its associated chordae. Mitral valve structure and function (in vivo preparations) were then assessed. Results: Ex vivo application of RFA resulted in qualitative reduction in mitral leaflet surface area and chordal length. Acute in vivo application of RFA to canines found to have MVP causing severe MR demonstrated a 43.7,60.7% statistically significant (P = 0.039) reduction in postablation MR. Chronic, in vivo, percutaneous application of RFA was found to be feasible and the engendered alterations durable. Conclusion: These data suggest that myxomatous mitral valve repair using radiofrequency energy delivered via catheter is feasible. [source] Implementation of three-dimensional wavelet encoding spectroscopic imaging: In vivo application and method comparisonMAGNETIC RESONANCE IN MEDICINE, Issue 1 2009Richard Young Abstract We have recently proposed a two-dimensional Wavelet Encoding-Spectroscopic Imaging (WE-SI) technique as an alternative to Chemical Shift Imaging (CSI), to reduce acquisition time and crossvoxel contamination in magnetic resonance spectroscopic imaging (MRSI). In this article we describe the extension of the WE-SI technique to three dimensions and its implementation on a clinical 1.5 T General Electric (GE) scanner. Phantom and in vivo studies are carried out to demonstrate the usefulness of this technique for further acquisition time reduction with low voxel contamination. In wavelet encoding, a set of dilated and translated prototype functions called wavelets are used to span a localized space by dividing it into a set of subspaces with predetermined sizes and locations. In spectroscopic imaging, this process is achieved using radiofrequency (RF) pulses with profiles resembling the wavelet shapes. Slice selective excitation and refocusing RF pulses, with single-band and dual-band profiles similar to Haar wavelets, are used in a modified PRESS sequence to acquire 3D WE-SI data. Wavelet dilation and translation are achieved by changing the strength of the localization gradients and frequency shift of the RF pulses, respectively. The desired spatial resolution in each direction sets the corresponding number of dilations (increases in the localization gradients), and consequently, the number of translations (frequency shift) of the Haar wavelets (RF pulses), which are used to collect magnetic resonance (MR) signals from the corresponding subspaces. Data acquisition time is reduced by using the minimum recovery time (TRmin), also called effective time, when successive MR signals from adjacent subspaces are collected. Inverse wavelet transform is performed on the acquired data to produce metabolite maps. The proposed WE-SI method is compared in terms of acquisition time, pixel bleed, and signal-to-noise ratio to the CSI technique. The study outcome shows that 3D WE-SI provides accurate results while reducing both acquisition time and voxel contamination. Magn Reson Med 61:6,15, 2009. © 2008 Wiley-Liss, Inc. [source] Amphoteric liposomes enable systemic antigen-presenting cell,directed delivery of CD40 antisense and are therapeutically effective in experimental arthritisARTHRITIS & RHEUMATISM, Issue 4 2009Evangelos Andreakos Objective Mediation of RNA interference by oligonucleotides constitutes a powerful approach for the silencing of genes involved in the pathogenesis of inflammatory disease, but in vivo application of this technique requires effective delivery to immune cells and/or sites of inflammation. The aim of the present study was to develop a new carrier system to mediate systemic administration of oligonucleotides to rheumatoid arthritis (RA) joints, and to develop an antisense oligonucleotide (ASO),based approach to interfere with CD40,CD154 interactions in an experimental model of RA. Methods A novel liposomal carrier with amphoteric properties, termed Nov038, was developed and assessed for its ability to systemically deliver an ASO directed against CD40 (CD40-ASO). Male DBA/1 mice with collagen-induced arthritis were treated with Nov038-encapsulated CD40-ASO, and the effects of treatment on various parameters of disease activity, including clinical score, paw swelling, lymph node responses, and inflammatory cytokine production in the joints, were assessed. Results Nov038 was well tolerated, devoid of immune-stimulatory effects, and efficacious in mediating systemic oligonucleotide delivery to sites of inflammation. In mice with collagen-induced arthritis, Nov038 enabled the therapeutic administration of CD40-ASO and improved established disease, while unassisted CD40-ASO was ineffective, and anti,tumor necrosis factor , (anti-TNF,) treatment was less effective in this model. Nov038/CD40-ASO efficacy was attributed to its tropism for monocyte/macrophages and myeloid dendritic cells (DCs), resulting in rapid down-regulation of CD40, inhibition of DC antigen presentation, and reduction in collagen-specific T cell responses, as well as decreased levels of TNF,, interleukin-6 (IL-6), and IL-17 in arthritic joints. Conclusion Amphoteric liposomes represent a novel carrier concept for systemic and antigen-presenting cell,targeted oligonucleotide delivery with clinical applicability and numerous potential applications, including target validation in vivo and inflammatory disease therapeutics. Moreover, Nov038/CD40-ASO constitutes a potent alternative to monoclonal antibody,based approaches for interfering with CD40,CD40L interactions. [source] Advances and Applications of Biodegradable Elastomers in Regenerative MedicineADVANCED FUNCTIONAL MATERIALS, Issue 2 2010Maria Concepcion Serrano Abstract When elastomers were first proposed as useful materials for regenerative medicine a few decades ago, their high versatility and suitability for a diverse and wide range of in vivo applications could not have been predicted. Due to their ability to recover after deformation, these materials were first introduced in tissue engineering in an attempt to mimic the mechanical properties of the extracellular matrix. Furthermore, elastomeric characteristics have been described as important criteria for cell interaction by modulating cellular behavior. From soft to hard tissues, elastomers have demonstrated degradation, mechanical, and biocompatibility requirements in accordance with the target tissue. In this feature article, biodegradable synthetic polyester elastomers that have been reported in the literature are discussed, with special focus on those that show promise for in vivo tissue replacement. Their satisfactory performance in vivo shows the promise of elastomers for use in regenerative medicine. However, further investigation is required to demonstrate the prospect of elastomer-based therapies in clinical trials. [source] Nanobiomaterials and Nanoanalysis: Opportunities for Improving the Science to Benefit Biomedical Technologies,ADVANCED MATERIALS, Issue 5 2008W. Grainger Abstract Nanomaterials advocated for biomedical applications must exhibit well-controlled surface properties to achieve optimum performance in complex biological or physiological fluids. Dispersed materials with extremely high specific surface areas require as extensive characterization as their macroscale biomaterials analogues. However, current literature is replete with many examples of nanophase materials, most notably nanoparticles, with little emphasis placed on reporting rigorous surface analysis or characterization, or in formal implementation of surface property standards needed to validate structure-property relationships for biomedical applications. Correlations of nanophase surface properties with their stability, toxicity and biodistributions are essential for in vivo applications. Surface contamination is likely, given their processing conditions and interfacial energies. Leaching adventitious adsorbates from high surface area nanomaterials is a possible toxicity mechanism. Polydimethylsiloxane (PDMS), long known as a ubiquitous contaminant in clean room conditions, chemical synthesis and microfabrication, remains a likely culprit in nanosystems fabrication, especially in synthesis, soft lithography and contact molding methods. New standards and expectations for analyzing the interfacial properties of nanoparticles and nano-fabricated technologies are required. Surface science analytical rigor similar to that applied to biomedical devices, nanophases in microelectronics and heterogeneous catalysts should serve as a model for nanomaterials characterization in biomedical technologies. [source] A flow cytometry-based assay for measuring invasion of red blood cells by Plasmodium falciparum,AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2010Amy K. Bei Variability in the ability of the malaria parasite Plasmodium falciparum to invade human erythrocytes is postulated to be an important determinant of disease severity. Both the parasite multiplication rate and erythrocyte selectivity are important parameters that underlie such variable invasion. We have established a flow cytometry-based method for simultaneously calculating both the parasitemia and the number of multiply-infected erythrocytes. Staining with the DNA-specific dye SYBR Green I allows quantitation of parasite invasion at the ring stage of parasite development. We discuss in vitro and in vivo applications and limitations of this method in relation to the study of parasite invasion. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source] Modification of pLL/DNA complexes with a multivalent hydrophilic polymer permits folate-mediated targeting in vitro and prolonged plasma circulation in vivoTHE JOURNAL OF GENE MEDICINE, Issue 5 2002Christopher M. Ward Abstract Background Gene delivery vectors based on poly(L -lysine) and DNA (pLL/DNA complexes) have limited use for targeted systemic application in vivo since they bind cells and proteins non-specifically. In this study we have attempted to form folate-targeted vectors with extended systemic circulation by surface modification of pLL/DNA complexes with hydrophilic polymers. Methods pLL/DNA complexes were stabilised by surface modification with a multivalent reactive polymer based on alternating segments of poly(ethylene glycol) and tripeptides bearing reactive ester groups. Folate moieties were incorporated into the vectors either by direct attachment of folate to the polymer or via intermediate poly(ethylene glycol) spacers of 800 and 3400,Da. Results Polymer-coated complexes show similar morphology to uncoated complexes, their zeta potential is decreased towards zero, serum protein binding is inhibited and aqueous solubility is substantially increased. Intravenous (i.v.) administration to mice of coated complexes produced extended systemic circulation, with up to 2000-fold more DNA measured in the bloodstream after 30,min compared with simple pLL/DNA complexes. In further contrast to simple pLL/DNA complexes, coated complexes do not bind blood cells in vivo. Folate receptor targeting is shown to mediate targeted association with HeLa cells in vitro, leading to increased transgene expression. We demonstrate for the first time that DNA uptake via the folate receptor is dependent on pEG spacer length, with the transgene expression relatively independent of the level of internalised DNA. Conclusions We show increased systemic circulation, decreased blood cell and protein binding, and folate-targeted transgene expression using pLL/DNA complexes surface-modified with a novel multireactive hydrophilic polymer. This work provides the basis for the development of plasma-circulating targeted vectors for in vivo applications. Copyright © 2002 John Wiley & Sons, Ltd. [source] MAGNETIC RESONANCE IN SURGICAL ONCOLOGY: II , LITERATURE REVIEWANZ JOURNAL OF SURGERY, Issue 6 2005Laurence Gluch Ex vivo and in vivo applications of magnetic resonance spectroscopy have been developed which aid in distinguishing malignant from normal tissues. Studies of breast, colon, cervix, oesophageal and prostate cancer reveal both the successes and failings of present technology. Verification that these non-invasive tests might supplant conventional histology in obtaining spatial diagnostic and chemical prognostic information remains for the time being illusive. [source] Enhancement of in vitro and in vivo microdialysis recovery of SB-265123 using Intralipid® and Encapsin® as perfusatesBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 1 2003Keith W. Ward Abstract This study was conducted to compare the ability of two potential microdialysis perfusates to enhance the recovery of SB-265123, a lipophilic, highly protein-bound compound, both in vitro and in vivo. Initial in vitro experiments established that the recovery of SB-265123 by microdialysis using normal saline as a perfusate was poor (1.7%). Different concentrations of Intralipid® and Encapsin® also were evaluated in an identical in vitro setting, to determine enhancement of recovery. In vitro recovery was enhanced to approximately 24 and 65% with 5 and 20% Intralipid®, and to approximately 59 and 62% with 5 and 20% Encapsin®, respectively. A rat in vivo study was conducted with 20% Encapsin® to confirm the in vitro observations. In the in vivo study, 75,80% recovery of free SB-265123 was achieved using 20% Encapsin® as a perfusate. The results from this study indicate that for SB-265123, a lipophilic, highly protein-bound molecule, Encapsin® is an efficient recovery enhancer in vitro. The results from this investigation further demonstrate that a recovery enhancer may be useful for in vivo applications, even with a compound that is highly bound to plasma protein. Copyright © 2002 John Wiley & Sons, Ltd. [source] Caged Protein Prenyltransferase Substrates: Tools for Understanding Protein PrenylationCHEMICAL BIOLOGY & DRUG DESIGN, Issue 3 2008Amanda J. DeGraw Originally designed to block the prenylation of oncogenic Ras, inhibitors of protein farnesyltransferase currently in preclinical and clinical trials are showing efficacy in cancers with normal Ras. Blocking protein prenylation has also shown promise in the treatment of malaria, Chagas disease and progeria syndrome. A better understanding of the mechanism, targets and in vivo consequences of protein prenylation are needed to elucidate the mode of action of current PFTase (Protein Farnesyltransferase) inhibitors and to create more potent and selective compounds. Caged enzyme substrates are useful tools for understanding enzyme mechanism and biological function. Reported here is the synthesis and characterization of caged substrates of PFTase. The caged isoprenoid diphosphates are poor substrates prior to photolysis. The caged CAAX peptide is a true catalytically caged substrate of PFTase in that it is to not a substrate, yet is able to bind to the enzyme as established by inhibition studies and X-ray crystallography. Irradiation of the caged molecules with 350 nm light readily releases their cognate substrate and their photolysis products are benign. These properties highlight the utility of those analogs towards a variety of in vitro and in vivo applications. [source] Template-synthesized Protein Nanotubes with Controlled Size Based on Layer-by-layer MethodCHINESE JOURNAL OF CHEMISTRY, Issue 2 2010Caihong Tao Abstract The protein nanotubes fabricated by a layer-by-layer deposition method using the porous alumina membrane as the template were described. The combination of the template method and the layer-by-layer assembly technique for the fabrication of protein nanotubes presented simplicity and versatility. The nanotubes composed of two kinds of proteins (bovine serum albumin and hemoglobin lyophilized bovine erythrocytes) with different sizes could be synthesized through this method. The outside diameter of the obtained nanotubes was determined by the diameter of the pores of the template. And the wall thickness of the protein nanotubes increased with the increase of the number of protein layers that made up of the walls of nanotubes. Such biodegradable nanotubes with good biocompatibility should be useful for in vivo applications. [source] Novel ceramic bone replacement material CeraBall® seeded with human mesenchymal stem cellsCLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2010Timothy Douglas Abstract Objectives: Hydroxyapatite (HA) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. A recently developed material for bone replacement is CeraBall®, which is a mixed HA,TCP scaffold available as porous spherical scaffolds of diameter 4 and 6 mm. Before their use as bone replacement materials in vivo, in vitro testing of these scaffolds is necessary. The goal of this study was to characterise 4 and 6 mm CeraBall® scaffolds in vitro with a view to their future use as bone replacement materials. Materials and methods: The proliferation of human mesenchymal stromal cells (hMSCs) seeded on CeraBall® scaffolds was evaluated quantitatively using the WST [Water soluble tetrazolium ((4-[3-(4- Iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate)] test and qualitatively by scanning electron microscopy (SEM). In addition, the standard MTT [(3-(4, 5-Dimenthylthiazol-2-Y1)-2, 5-Diphenyltetrazolium bromide)] biocompatibility test and cell vitality staining were performed using hMSCs. CeraBall® scaffolds were also tested for their mechanical properties. Results: SEM and WST test results showed that hMSCs proliferated on CeraBall® scaffolds over the course of 9 days. Proliferation was similar to that seen on tissue culture polystyrene (control). Cells showed a well-spread morphology and formed ,sheets' on the surface of scaffolds. Invasion of pores was observed. Good biocompatibility was demonstrated by MTT test results and cell vitality staining. Scaffolds of both 4 and 6 mm were able to withstand compressive loads of 5 N. Conclusions: CeraBall® scaffolds show good biocompatibility in vitro for hMSCs. This opens the way for in vivo applications. To cite this article: Douglas T, Liu Q, Humpe A, Wiltfang J, Sivananthan S, Warnke PH. Novel ceramic bone replacement material CeraBall® seeded with human mesenchymal stem cells. Clin. Oral Impl. Res. 21, 2010; 262,267. doi: 10.1111/j.1600-0501.2009.01818.x [source] | |||||||||||||||||||