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Sample records for perfusion higher cell

  1. Perfusion based cell culture chips

    DEFF Research Database (Denmark)

    Heiskanen, Arto; Emnéus, Jenny; Dufva, Martin

    2010-01-01

    Performing cell culture in miniaturized perfusion chambers gives possibilities to experiment with cells under near in vivo like conditions. In contrast to traditional batch cultures, miniaturized perfusion systems provide precise control of medium composition, long term unattended cultures...... and tissue like structuring of the cultures. However, as this chapter illustrates, many issues remain to be identified regarding perfusion cell culture such as design, material choice and how to use these systems before they will be widespread amongst biomedical researchers....

  2. Cancer cells growing on perfused 3D collagen model produced higher reactive oxygen species level and were more resistant to cisplatin compared to the 2D model.

    Science.gov (United States)

    Liu, Qingxi; Zhang, Zijiang; Liu, Yupeng; Cui, Zhanfeng; Zhang, Tongcun; Li, Zhaohui; Ma, Wenjian

    2018-03-01

    Three-dimensional (3D) collagen scaffold models, due to their ability to mimic the tissue and organ structure in vivo, have received increasing interest in drug discovery and toxicity evaluation. In this study, we developed a perfused 3D model and studied cellular response to cytotoxic drugs in comparison with traditional 2D cell cultures as evaluated by cancer drug cisplatin. Cancer cells grown in perfused 3D environments showed increased levels of reactive oxygen species (ROS) production compared to the 2D culture. As determined by growth analysis, cells in the 3D culture, after forming a spheroid, were more resistant to the cancer drug cisplatin compared to that of the 2D cell culture. In addition, 3D culturing cells showed elevated level of ROS, indicating a physiological change or the formation of a microenvironment that resembles tumor cells in vivo. These data revealed that cellular response to drugs for cells growing in 3D environments are dramatically different from that of 2D cultured cells. Thus, the perfused 3D collagen scaffold model we report here might be a potentially very useful tool for drug analysis.

  3. Development of a microfluidic perfusion 3D cell culture system

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    Park, D. H.; Jeon, H. J.; Kim, M. J.; Nguyen, X. D.; Morten, K.; Go, J. S.

    2018-04-01

    Recently, 3-dimensional in vitro cell cultures have gained much attention in biomedical sciences because of the closer relevance between in vitro cell cultures and in vivo environments. This paper presents a microfluidic perfusion 3D cell culture system with consistent control of long-term culture conditions to mimic an in vivo microenvironment. It consists of two sudden expansion reservoirs to trap incoming air bubbles, gradient generators to provide a linear concentration, and microchannel mixers. Specifically, the air bubbles disturb a flow in the microfluidic channel resulting in the instability of the perfusion cell culture conditions. For long-term stable operation, the sudden expansion reservoir is designed to trap air bubbles by using buoyancy before they enter the culture system. The performance of the developed microfluidic perfusion 3D cell culture system was examined experimentally and compared with analytical results. Finally, it was applied to test the cytotoxicity of cells infected with Ewing’s sarcoma. Cell death was observed for different concentrations of H2O2. For future work, the developed microfluidic perfusion 3D cell culture system can be used to examine the behavior of cells treated with various drugs and concentrations for high-throughput drug screening.

  4. Impairment of myocardial perfusion in children with sickle cell disease

    International Nuclear Information System (INIS)

    Maunoury, C.; Acar, P.; Montalembert, M. de

    2003-01-01

    While brain, bone and spleen strokes are well documented in children with sickle cell disease (SCD), impairment of myocardial perfusion is an unknown complication. Non invasive techniques such as exercise testing and echocardiography have a low sensitivity to detect myocardial ischemia in patients with SCD. We have prospectively assessed myocardial perfusion with Tl-201 SPECT in 23 patients with SCD (10 female, 13 male, mean age 12 ± 5 years). Myocardial SPECT was performed after stress and 3 hours later after reinjection on a single head gamma camera equipped with a LEAP collimator (64 x 64 matrix size format, 30 projections over 180 deg C, 30 seconds per step). Left ventricular ejection fraction (LVEF) was assessed by equilibrium radionuclide angiography at rest on the same day. Myocardial perfusion was impaired in 14/23 patients: 9 reversible defects and 5 fixed defects. The left ventricular cavity was dilated in 14/23 patients. The mean LVEF was 63 ± 9%. There was no relationship between myocardial perfusion and left ventricular dilation or function. The frequent impairment of myocardial perfusion in children with SCD could lead to suggest a treatment with hydroxyurea, an improvement of perfusion can be noted with hydroxyurea. (author)

  5. Perfusion cell culture decreases process and product heterogeneity in a head-to-head comparison with fed-batch.

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    Walther, Jason; Lu, Jiuyi; Hollenbach, Myles; Yu, Marcella; Hwang, Chris; McLarty, Jean; Brower, Kevin

    2018-05-30

    In this study, we compared the impacts of fed-batch and perfusion platforms on process and product attributes for IgG1- and IgG4-producing cell lines. A "plug-and-play" approach was applied to both platforms at bench scale, using commercially available basal and feed media, a standard feed strategy for fed-batch, and ATF filtration for perfusion. Product concentration in fed-batch was 2.5 times greater than perfusion, while average productivity in perfusion was 7.5 times greater than fed-batch. PCA revealed more variability in the cell environment and metabolism during the fed-batch run. LDH measurements showed that exposure of product to cell lysate was 7-10 times greater in fed-batch. Product analysis shows larger abundances of neutral species in perfusion, likely due to decreased bioreactor residence times and extracellular exposure. The IgG1 perfusion product also had higher purity and lower half-antibody. Glycosylation was similar across both culture modes. The first perfusion harvest slice for both product types showed different glycosylation than subsequent harvests, suggesting that product quality lags behind metabolism. In conclusion, process and product data indicate that intra-lot heterogeneity is decreased in perfusion cultures. Additional data and discussion is required to understand the developmental, clinical and commercial implications, and in what situations increased uniformity would be beneficial. This article is protected by copyright. All rights reserved.

  6. The relationship between red blood cell deformability metrics and perfusion of an artificial microvascular network.

    Science.gov (United States)

    Sosa, Jose M; Nielsen, Nathan D; Vignes, Seth M; Chen, Tanya G; Shevkoplyas, Sergey S

    2014-01-01

    The ability of red blood cells (RBC) to undergo a wide range of deformations while traversing the microvasculature is crucial for adequate perfusion. Interpretation of RBC deformability measurements performed in vitro in the context of microvascular perfusion has been notoriously difficult. This study compares the measurements of RBC deformability performed using micropore filtration and ektacytometry with the RBC ability to perfuse an artificial microvascular network (AMVN). Human RBCs were collected from healthy consenting volunteers, leukoreduced, washed and exposed to graded concentrations (0-0.08%) of glutaraldehyde (a non-specific protein cross-linker) and diamide (a spectrin-specific protein cross-linker) to impair the deformability of RBCs. Samples comprising cells with two different levels of deformability were created by adding non-deformable RBCs (hardened by exposure to 0.08% glutaraldehyde) to the sample of normal healthy RBCs. Ektacytometry indicated a nearly linear decline in RBC deformability with increasing glutaraldehyde concentration. Micropore filtration showed a significant reduction only for concentrations of glutaraldehyde higher than 0.04%. Neither micropore filtration nor ektacytometry measurements could accurately predict the AMVN perfusion. Treatment with diamide reduced RBC deformability as indicated by ektacytometry, but had no significant effect on either micropore filtration or the AMVN perfusion. Both micropore filtration and ektacytometry showed a linear decline in effective RBC deformability with increasing fraction of non-deformable RBCs in the sample. The corresponding decline in the AMVN perfusion plateaued above 50%, reflecting the innate ability of blood flow in the microvasculature to bypass occluded capillaries. Our results suggest that in vitro measurements of RBC deformability performed using either micropore filtration or ektacytometry may not represent the ability of same RBCs to perfuse microvascular networks. Further

  7. Improved Performance in Mammalian Cell Perfusion Cultures by Growth Inhibition.

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    Wolf, Moritz K F; Closet, Aurélie; Bzowska, Monika; Bielser, Jean-Marc; Souquet, Jonathan; Broly, Hervé; Morbidelli, Massimo

    2018-05-21

    Mammalian cell perfusion cultures represent a promising alternative to the current fed-batch technology for the production of various biopharmaceuticals. Long-term operation at a fixed viable cell density (VCD) requires a viable culture and a constant removal of excessive cells. Product loss in the cell removing bleed stream deteriorates the process yield. In this study, the authors investigate the use of chemical and environmental growth inhibition on culture performance by either adding valeric acid (VA) to the production media or by reducing the culture temperature (33.0 °C) with respect to control conditions (36.5 °C, no VA). Low temperature significantly reduces cellular growth, thus, resulting in lower bleed rates accompanied by a reduced product loss of 11% compared to 26% under control conditions. Additionally, the cell specific productivity of the target protein improves and maintained stable leading to media savings per mass of product. VA shows initially an inhibitory effect on cellular growth. However, cells seemed to adapt to the presence of the inhibitor resulting in a recovery of the cellular growth. Cell cycle and Western blot analyses support the observed results. This work underlines the role of temperature as a key operating variable for the optimization of perfusion cultures. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Microfluidically supported biochip design for culture of endothelial cell layers with improved perfusion conditions.

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    Raasch, Martin; Rennert, Knut; Jahn, Tobias; Peters, Sven; Henkel, Thomas; Huber, Otmar; Schulz, Ingo; Becker, Holger; Lorkowski, Stefan; Funke, Harald; Mosig, Alexander

    2015-03-02

    Hemodynamic forces generated by the blood flow are of central importance for the function of endothelial cells (ECs), which form a biologically active cellular monolayer in blood vessels and serve as a selective barrier for macromolecular permeability. Mechanical stimulation of the endothelial monolayer induces morphological remodeling in its cytoskeleton. For in vitro studies on EC biology culture devices are desirable that simulate conditions of flow in blood vessels and allow flow-based adhesion/permeability assays under optimal perfusion conditions. With this aim we designed a biochip comprising a perfusable membrane that serves as cell culture platform multi-organ-tissue-flow (MOTiF biochip). This biochip allows an effective supply with nutrition medium, discharge of catabolic cell metabolites and defined application of shear stress to ECs under laminar flow conditions. To characterize EC layers cultured in the MOTiF biochip we investigated cell viability, expression of EC marker proteins and cell adhesion molecules of ECs dynamically cultured under low and high shear stress, and compared them with an endothelial culture in established two-dimensionally perfused flow chambers and under static conditions. We show that ECs cultured in the MOTiF biochip form a tight EC monolayer with increased cellular density, enhanced cell layer thickness, presumably as the result of a rapid and effective adaption to shear stress by remodeling of the cytoskeleton. Moreover, endothelial layers in the MOTiF biochip express higher amounts of EC marker proteins von-Willebrand-factor and PECAM-1. EC layers were highly responsive to stimulation with TNFα as detected at the level of ICAM-1, VCAM-1 and E-selectin expression and modulation of endothelial permeability in response to TNFα/IFNγ treatment under flow conditions. Compared to static and two-dimensionally perfused cell culture condition we consider MOTiF biochips as a valuable tool for studying EC biology in vitro under

  9. Differentiation of low- and high-grade clear cell renal cell carcinoma: Tumor size versus CT perfusion parameters.

    Science.gov (United States)

    Chen, Chao; Kang, Qinqin; Xu, Bing; Guo, Hairuo; Wei, Qiang; Wang, Tiegong; Ye, Hui; Wu, Xinhuai

    To compare the utility of tumor size and CT perfusion parameters for differentiation of low- and high-grade clear cell renal cell carcinoma (RCC). Tumor size, Equivalent blood volume (Equiv BV), permeability surface-area product (PS), blood flow (BF), and Fuhrman pathological grading of clear cell RCC were retrospectively analyzed. High-grade clear cell RCC had significantly higher tumor size and lower PS than low grade. Tumor size positively correlated with Fuhrman grade, but PS negatively did. Tumor size and PS were significantly independent indexes for differentiating high-grade from low-grade clear cell RCC. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Higher cerebral oxygen saturation may provide higher urinary output during continuous regional cerebral perfusion

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    Tomoyasu Takahiro

    2008-10-01

    Full Text Available Abstract Objective We examined the hypothesis that higher cerebral oxygen saturation (rSO2 during RCP is correlated with urinary output. Methods Between December 2002 and August 2006, 12 patients aged 3 to 61 days and weighing 2.6 to 3.4 kg underwent aortic arch repair with RCP. Urinary output and rSO2 were analyzed retrospectively. Data were assigned to either of 2 groups according to their corresponding rSO2: Group A (rSO2 ≦ 75% and Group B (rSO2 Results Seven and 5 patients were assigned to Group A and Group B, respectively. Group A was characterized by mean radial arterial pressure (37.9 ± 9.6 vs 45.8 ± 7.8 mmHg; P = 0.14 and femoral arterial pressure (6.7 ± 6.1 vs 20.8 ± 14.6 mmHg; P = 0.09 compared to Group B. However, higher urinary output during CPB (1.03 ± 1.18 vs 0.10 ± 0.15 ml·kg-1·h-1; P = 0.03. Furthermore our results indicate that a higher dose of Chlorpromazine was used in Group A (2.9 ± 1.4 vs 1.7 ± 1.0 mg/kg; P = 0.03. Conclusion Higher cerebral oxygenation may provide higher urinary output due to higher renal blood flow through collateral circulation.

  11. Metabolic and Kinetic analyses of influenza production in perfusion HEK293 cell culture

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    Lohr Verena

    2011-09-01

    Full Text Available Abstract Background Cell culture-based production of influenza vaccine remains an attractive alternative to egg-based production. Short response time and high production yields are the key success factors for the broader adoption of cell culture technology for industrial manufacturing of pandemic and seasonal influenza vaccines. Recently, HEK293SF cells have been successfully used to produce influenza viruses, achieving hemagglutinin (HA and infectious viral particle (IVP titers in the highest ranges reported to date. In the same study, it was suggested that beyond 4 × 106 cells/mL, viral production was limited by a lack of nutrients or an accumulation of toxic products. Results To further improve viral titers at high cell densities, perfusion culture mode was evaluated. Productivities of both perfusion and batch culture modes were compared at an infection cell density of 6 × 106 cells/mL. The metabolism, including glycolysis, glutaminolysis and amino acids utilization as well as physiological indicators such as viability and apoptosis were extensively documented for the two modes of culture before and after viral infection to identify potential metabolic limitations. A 3 L bioreactor with a perfusion rate of 0.5 vol/day allowed us to reach maximal titers of 3.3 × 1011 IVP/mL and 4.0 logHA units/mL, corresponding to a total production of 1.0 × 1015 IVP and 7.8 logHA units after 3 days post-infection. Overall, perfusion mode titers were higher by almost one order of magnitude over the batch culture mode of production. This improvement was associated with an activation of the cell metabolism as seen by a 1.5-fold and 4-fold higher consumption rates of glucose and glutamine respectively. A shift in the viral production kinetics was also observed leading to an accumulation of more viable cells with a higher specific production and causing an increase in the total volumetric production of infectious influenza particles. Conclusions These results

  12. Microfluidic perfusion culture of human induced pluripotent stem cells under fully defined culture conditions.

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    Yoshimitsu, Ryosuke; Hattori, Koji; Sugiura, Shinji; Kondo, Yuki; Yamada, Rotaro; Tachikawa, Saoko; Satoh, Taku; Kurisaki, Akira; Ohnuma, Kiyoshi; Asashima, Makoto; Kanamori, Toshiyuki

    2014-05-01

    Human induced pluripotent stem cells (hiPSCs) are a promising cell source for drug screening. For this application, self-renewal or differentiation of the cells is required, and undefined factors in the culture conditions are not desirable. Microfluidic perfusion culture allows the production of small volume cultures with precisely controlled microenvironments, and is applicable to high-throughput cellular environment screening. Here, we developed a microfluidic perfusion culture system for hiPSCs that uses a microchamber array chip under defined extracellular matrix (ECM) and culture medium conditions. By screening various ECMs we determined that fibronectin and laminin are appropriate for microfluidic devices made out of the most popular material, polydimethylsiloxane (PDMS). We found that the growth rate of hiPSCs under pressure-driven perfusion culture conditions was higher than under static culture conditions in the microchamber array. We applied our new system to self-renewal and differentiation cultures of hiPSCs, and immunocytochemical analysis showed that the state of the hiPSCs was successfully controlled. The effects of three antitumor drugs on hiPSCs were comparable between microchamber array and 96-well plates. We believe that our system will be a platform technology for future large-scale screening of fully defined conditions for differentiation cultures on integrated microfluidic devices. © 2013 Wiley Periodicals, Inc.

  13. Assessing tumor treatment response and prognosis in non-small cell lung cancer with perfusion CT

    International Nuclear Information System (INIS)

    Wang Jianwei; Wu Ning; Song Ying

    2010-01-01

    Objective: To prospectively investigate whether any of the perfusion parameters would predict early tumor response to chemotherapy and/or radiotherapy and prognosis in non-small cell lung cancer (NSCLC). Methods: In a prospective series, Perfusion CT were performed in 152 patients suspected lung cancer with 16-slice or 8-slice multislice CT. Contrast medium (50 ml) was injected at a rate of 4 ml/s with a power injector. The scanning delay was 10 seconds and the scanning time was 50 seconds. Among 152 patients, 123 patients were proved lung cancer by pathology. With the perfusion 3.0 software, the parameters including blood flow (BF), blood volume (BV), mean transit time (MTT) and capillary permeability surface area product (PS) were calculated. The perfusion image quality was evaluated on a 4-1eveal scale. The treatment response after chemotherapy and (or) radiotherapy was assessed with Response Evaluation Criteria in Solid Tumors (RECIST), and then the relationship between perfusion parameters with early tumor response to chemotherapy and (or) radiotherapy was evaluated. Student t test and Kaplan-Meier estimates were used for data analysis. Results: In 84 patients (68.3%), the perfusion image quality was staged level 2 (moderate) and level 3 (good). Among them, 35 patients with NSCLC were assessed with RECIST after chemotherapy and (or) radiotherapy. In these 35 patients, The BF of responders and nonresponders was (81.0 ± 33.6)and (56.3 ± 23.1) ml · min -1 ·100 g -1 , respectively, which was significantly different(t=2.393, P=0.023). The median PFS of low-BF group (BF ≤ 80 ml · min -1 · 100 g -1 ) and high-BF group (BF>80 ml · min -1 · 100 g -1 ) was 11.8 and 8.0 months respectively (P>0.05), and the median PFS of low-BV group (BF ≤ 6 ml/100 g -1 ) and high-BV group (BF>6 ml/100 g -1 ) was 9.2 and 8.0 months respectively(P>0.05), both of them were not significantly different. Conclusion: NSCLC in high perfusion are relatively sensitive to chemotherapy

  14. Transfection in perfused microfluidic cell culture devices: A case study.

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    Raimes, William; Rubi, Mathieu; Super, Alexandre; Marques, Marco P C; Veraitch, Farlan; Szita, Nicolas

    2017-08-01

    Automated microfluidic devices are a promising route towards a point-of-care autologous cell therapy. The initial steps of induced pluripotent stem cell (iPSC) derivation involve transfection and long term cell culture. Integration of these steps would help reduce the cost and footprint of micro-scale devices with applications in cell reprogramming or gene correction. Current examples of transfection integration focus on maximising efficiency rather than viable long-term culture. Here we look for whole process compatibility by integrating automated transfection with a perfused microfluidic device designed for homogeneous culture conditions. The injection process was characterised using fluorescein to establish a LabVIEW-based routine for user-defined automation. Proof-of-concept is demonstrated by chemically transfecting a GFP plasmid into mouse embryonic stem cells (mESCs). Cells transfected in the device showed an improvement in efficiency (34%, n = 3) compared with standard protocols (17.2%, n = 3). This represents a first step towards microfluidic processing systems for cell reprogramming or gene therapy.

  15. Perfusion directed 3D mineral formation within cell-laden hydrogels.

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    Sawyer, Stephen William; Shridhar, Shivkumar Vishnempet; Zhang, Kairui; Albrecht, Lucas; Filip, Alex; Horton, Jason; Soman, Pranav

    2018-06-08

    Despite the promise of stem cell engineering and the new advances in bioprinting technologies, one of the major challenges in the manufacturing of large scale bone tissue scaffolds is the inability to perfuse nutrients throughout thick constructs. Here, we report a scalable method to create thick, perfusable bone constructs using a combination of cell-laden hydrogels and a 3D printed sacrificial polymer. Osteoblast-like Saos-2 cells were encapsulated within a gelatin methacrylate (GelMA) hydrogel and 3D printed polyvinyl alcohol (PVA) pipes were used to create perfusable channels. A custom-built bioreactor was used to perfuse osteogenic media directly through the channels in order to induce mineral deposition which was subsequently quantified via microCT. Histological staining was used to verify mineral deposition around the perfused channels, while COMSOL modeling was used to simulate oxygen diffusion between adjacent channels. This information was used to design a scaled-up construct containing a 3D array of perfusable channels within cell-laden GelMA. Progressive matrix mineralization was observed by cells surrounding perfused channels as opposed to random mineral deposition in static constructs. MicroCT confirmed that there was a direct relationship between channel mineralization within perfused constructs and time within the bioreactor. Furthermore, the scalable method presented in this work serves as a model on how large-scale bone tissue replacement constructs could be made using commonly available 3D printers, sacrificial materials, and hydrogels. © 2018 IOP Publishing Ltd.

  16. CULTIVATION OF HUMAN LIVER CELLS AND ADIPOSE-DERIVED MESENCHYMAL STROMAL CELLS IN PERFUSION BIOREACTOR

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    Yu. В. Basok

    2018-01-01

    Full Text Available Aim: to show the progress of the experiment of cultivation of human liver cells and adipose-derived mesenchymal stromal cells in perfusion bioreactor.Materials and methods. The cultivation of a cell-engineered construct, consisting of a biopolymer microstructured collagen-containing hydrogel, human liver cells, adipose-derived mesenchymal stromal cells, and William’s E Medium, was performed in a perfusion bioreactor.Results. On the 7th day large cells with hepatocyte morphology – of a polygonal shape and a centrally located round nucleus, – were present in the culture chambers of the bioreactor. The metabolic activity of hepatocytes in cell-engineered constructs was confi rmed by the presence of urea in the culture medium on the seventh day of cultivation in the bioreactor and by the resorption of a biopolymer microstructured collagen-containing hydrogel.

  17. Flow perfusion culture of human mesenchymal stem cells on coralline hydroxyapatite scaffolds with various pore sizes

    DEFF Research Database (Denmark)

    Bjerre, Lea; Bünger, Cody; Baatrup, Anette

    2011-01-01

    of this study was to obtain a clinically relevant substitute size using a direct perfusion culture system. Human bone marrowderived mesenchymal stem cells were seeded on coralline hydroxyapatite scaffolds with 200 μm or 500 μm pores, and resulting constructs were cultured in a perfusion bioreactor or in static...

  18. A pump-free microfluidic 3D perfusion platform for the efficient differentiation of human hepatocyte-like cells.

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    Ong, Louis Jun Ye; Chong, Lor Huai; Jin, Lin; Singh, Pawan Kumar; Lee, Poh Seng; Yu, Hanry; Ananthanarayanan, Abhishek; Leo, Hwa Liang; Toh, Yi-Chin

    2017-10-01

    The practical application of microfluidic liver models for in vitro drug testing is partly hampered by their reliance on human primary hepatocytes, which are limited in number and have batch-to-batch variation. Human stem cell-derived hepatocytes offer an attractive alternative cell source, although their 3D differentiation and maturation in a microfluidic platform have not yet been demonstrated. We develop a pump-free microfluidic 3D perfusion platform to achieve long-term and efficient differentiation of human liver progenitor cells into hepatocyte-like cells (HLCs). The device contains a micropillar array to immobilize cells three-dimensionally in a central cell culture compartment flanked by two side perfusion channels. Constant pump-free medium perfusion is accomplished by controlling the differential heights of horizontally orientated inlet and outlet media reservoirs. Computational fluid dynamic simulation is used to estimate the hydrostatic pressure heads required to achieve different perfusion flow rates, which are experimentally validated by micro-particle image velocimetry, as well as viability and functional assessments in a primary rat hepatocyte model. We perform on-chip differentiation of HepaRG, a human bipotent progenitor cell, and discover that 3D microperfusion greatly enhances the hepatocyte differentiation efficiency over static 2D and 3D cultures. However, HepaRG progenitor cells are highly sensitive to the time-point at which microperfusion is applied. Isolated HepaRG cells that are primed as static 3D spheroids before being subjected to microperfusion yield a significantly higher proportion of HLCs (92%) than direct microperfusion of isolated HepaRG cells (62%). This platform potentially offers a simple and efficient means to develop highly functional microfluidic liver models incorporating human stem cell-derived HLCs. Biotechnol. Bioeng. 2017;114: 2360-2370. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Impairment of myocardial perfusion in children with sickle cell disease; Alteration de la perfusion myocardique chez l'enfant drepanocytaire

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    Maunoury, C. [Hopital Necker-Enfants-Malades, Service de Medecine Nucleaire, 75 - Paris (France); Acar, P. [Centre Hospitalier Universitaire, Hopital des Enfants, Service de Cardiologie Pediatrique, 31 - Toulouse (France); Montalembert, M. de [Hopital Necker-Enfants-Malades, Service de Pediatrie Generale, 75 - Paris (France)

    2003-10-01

    While brain, bone and spleen strokes are well documented in children with sickle cell disease (SCD), impairment of myocardial perfusion is an unknown complication. Non invasive techniques such as exercise testing and echocardiography have a low sensitivity to detect myocardial ischemia in patients with SCD. We have prospectively assessed myocardial perfusion with Tl-201 SPECT in 23 patients with SCD (10 female, 13 male, mean age 12 {+-} 5 years). Myocardial SPECT was performed after stress and 3 hours later after reinjection on a single head gamma camera equipped with a LEAP collimator (64 x 64 matrix size format, 30 projections over 180 deg C, 30 seconds per step). Left ventricular ejection fraction (LVEF) was assessed by equilibrium radionuclide angiography at rest on the same day. Myocardial perfusion was impaired in 14/23 patients: 9 reversible defects and 5 fixed defects. The left ventricular cavity was dilated in 14/23 patients. The mean LVEF was 63 {+-} 9%. There was no relationship between myocardial perfusion and left ventricular dilation or function. The frequent impairment of myocardial perfusion in children with SCD could lead to suggest a treatment with hydroxyurea, an improvement of perfusion can be noted with hydroxyurea. (author)

  20. AMC-Bio-Artificial Liver culturing enhances mitochondrial biogenesis in human liver cell lines: The role of oxygen, medium perfusion and 3D configuration

    NARCIS (Netherlands)

    Adam, Aziza A. A.; van Wenum, Martien; van der Mark, Vincent A.; Jongejan, Aldo; Moerland, Perry D.; Houtkooper, Riekelt H.; Wanders, Ronald J. A.; Oude Elferink, Ronald P.; Chamuleau, Robert A. F. M.; Hoekstra, Ruurdtje

    2017-01-01

    Human liver cell lines, like HepaRG and C3A, acquire higher functionality when cultured in the AMC-Bio-Artificial Liver (AMC-BAL). The three main differences between BAL and monolayer culture are the oxygenation (40% vs 20%O2), dynamic vs absent medium perfusion and 3D vs 2D configuration. Here, we

  1. Effect of nicorandil on the myocardial tissue perfusion and myocardial cell injury in patients with diabetes after PCI

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    Xue-Li Ren1

    2017-04-01

    Full Text Available Objective: To study the effect of nicorandil on the myocardial tissue perfusion and myocardial cell damage in patients with diabetes after percutaneous coronary intervention (PCI. Methods: 68 patients with coronary heart disease and type 2 diabetes mellitus who received PCI in our hospital between May 2011 and September 2015 were collected and then divided into observation group and control group (n=34 according to the single-blind randomized control method. Control group of patients received PCI alone, and the observation group of patients received nicorandil therapy after PCI. After treatment, real-time myocardial ultrasound contrast was used to evaluate the myocardial perfusion of two groups of patients; blood biochemical analyzer was used to detect the contents of peripheral blood myocardial enzyme spectrum indexes; the ELISA method was used to detect the contents of serum oxidative stress indicators; RIA method was used to detect the contents of serum apoptosis molecules. Results: After treatment, the myocardial tissue perfusion parameters plateau peak intensity (A, slope rate of curve (β and myocardial blood flow (A×β levels of observation group were significantly higher than those of control group (P<0.05; peripheral blood myocardial enzyme spectrum indexes creatine kinase (CK, lactate dehydrogenase (LDH, troponin I (cTnI and glutamic oxalacetic transaminase (GOT contents of observation group were significantly lower than those of control group (P<0.05; serum vitamin E (VitE and vitamin C (VitC contents of observation group were significantly higher than those of control group while malondialdehyde (MDA, advanced oxidation protein products (AOPPs, soluble apoptosis-associated factor (sFas and soluble apoptosis-associated factor ligand (sFasL contents were lower than those of control group (P<0.05. Conclusion: Adjuvant nicorandil therapy can improve the myocardial perfusion and reduce the myocardial cell injury in patients with coronary

  2. Cell-swelling-induced taurine release from isolated perfused rat liver

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    Brand, H. S.; Meijer, A. J.; Gustafson, L. A.; Jörning, G. G.; Leegwater, A. C.; Maas, M. A.; Chamuleau, R. A.

    1994-01-01

    Astrocytes and lymphocytes are able to release significant amounts of taurine during periods of hypotonicity to reduce the increase in cell volume. To investigate this mechanism in the liver, we studied the release of free amino acids from isolated perfused rat liver during hypotonicity. The

  3. MicroRNA-93 controls perfusion recovery after hindlimb ischemia by modulating expression of multiple genes in the cell cycle pathway.

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    Hazarika, Surovi; Farber, Charles R; Dokun, Ayotunde O; Pitsillides, Achillieas N; Wang, Tao; Lye, R John; Annex, Brian H

    2013-04-30

    MicroRNAs are key regulators of gene expression in response to injury, but there is limited knowledge of their role in ischemia-induced angiogenesis, such as in peripheral arterial disease. Here, we used an unbiased strategy and took advantage of different phenotypic outcomes that follow surgically induced hindlimb ischemia between inbred mouse strains to identify key microRNAs involved in perfusion recovery from hindlimb ischemia. From comparative microRNA profiling between inbred mouse strains that display profound differences in their extent of perfusion recovery after hindlimb ischemia, we found that the mouse strain with higher levels of microRNA-93 (miR-93) in hindlimb muscle before ischemia and the greater ability to upregulate miR-93 in response to ischemia had better perfusion recovery. In vitro, overexpression of miR-93 attenuated hypoxia-induced apoptosis in both endothelial and skeletal muscle cells and enhanced proliferation in both cell types. In addition, miR-93 overexpression enhanced endothelial cell tube formation. In vivo, miR-93 overexpression enhanced capillary density and perfusion recovery from hindlimb ischemia, and antagomirs to miR-93 attenuated perfusion recovery. Both in vitro and in vivo modulation of miR-93 resulted in alterations in the expression of >1 cell cycle pathway gene in 2 different cell types. Our data indicate that miR-93 enhances perfusion recovery from hindlimb ischemia by modulation of multiple genes that coordinate the functional pathways of cell proliferation and apoptosis. Thus, miR-93 is a strong potential target for pharmacological modulation to promote angiogenesis in ischemic tissue.

  4. Perfusion of veins at arterial pressure increases the expression of KLF5 and cell cycle genes in smooth muscle cells

    International Nuclear Information System (INIS)

    Amirak, Emre; Zakkar, Mustafa; Evans, Paul C.; Kemp, Paul R.

    2010-01-01

    Vascular smooth muscle cell (VSMC) proliferation remains a major cause of veno-arterial graft failure. We hypothesised that exposure of venous SMCs to arterial pressure would increase KLF5 expression and that of cell cycle genes. Porcine jugular veins were perfused at arterial or venous pressure in the absence of growth factors. The KLF5, c-myc, cyclin-D and cyclin-E expression were elevated within 24 h of perfusion at arterial pressure but not at venous pressure. Arterial pressure also reduced the decline in SM-myosin heavy chain expression. These data suggest a role for KLF5 in initiating venous SMCs proliferation in response to arterial pressure.

  5. Induced Human Decidual NK-Like Cells Improve Utero-Placental Perfusion in Mice.

    Directory of Open Access Journals (Sweden)

    Ricardo C Cavalli

    Full Text Available Decidual NK (dNK cells, a distinct type of NK cell, are thought to regulate uterine spiral artery remodeling, a process that allows for increased blood delivery to the fetal-placental unit. Impairment of uterine spiral artery remodeling is associated with decreased placental perfusion, increased uterine artery resistance, and obstetric complications such as preeclampsia and intrauterine growth restriction. Ex vivo manipulation of human peripheral blood NK (pNK cells by a combination of hypoxia, TGFß-1 and 5-aza-2'-deoxycytidine yields cells with phenotypic and in vitro functional similarities to dNK cells, called idNK cells. Here, gene expression profiling shows that CD56Bright idNK cells derived ex vivo from human pNK cells, and to a lesser extent CD56Dim idNK cells, are enriched in the gene expression signature that distinguishes dNK cells from pNK cells. When injected into immunocompromised pregnant mice with elevated uterine artery resistance, idNK cells homed to the uterus and reduced the uterine artery resistance index, suggesting improved placental perfusion.

  6. High cell density suppresses BMP4-induced differentiation of human pluripotent stem cells to produce macroscopic spatial patterning in a unidirectional perfusion culture chamber.

    Science.gov (United States)

    Tashiro, Shota; Le, Minh Nguyen Tuyet; Kusama, Yuta; Nakatani, Eri; Suga, Mika; Furue, Miho K; Satoh, Taku; Sugiura, Shinji; Kanamori, Toshiyuki; Ohnuma, Kiyoshi

    2018-04-19

    Spatial pattern formation is a critical step in embryogenesis. Bone morphogenetic protein 4 (BMP4) and its inhibitors are major factors for the formation of spatial patterns during embryogenesis. However, spatial patterning of the human embryo is unclear because of ethical issues and isotropic culture environments resulting from conventional culture dishes. Here, we utilized human pluripotent stem cells (hiPSCs) and a simple anisotropic (unidirectional perfusion) culture chamber, which creates unidirectional conditions, to measure the cell community effect. The influence of cell density on BMP4-induced differentiation was explored during static culture using a conventional culture dish. Immunostaining of the early differentiation marker SSEA-1 and the mesendoderm marker BRACHYURY revealed that high cell density suppressed differentiation, with small clusters of differentiated and undifferentiated cells formed. Addition of five-fold higher concentration of BMP4 showed similar results, suggesting that suppression was not caused by depletion of BMP4 but rather by high cell density. Quantitative RT-PCR array analysis showed that BMP4 induced multi-lineage differentiation, which was also suppressed under high-density conditions. We fabricated an elongated perfusion culture chamber, in which proteins were transported unidirectionally, and hiPSCs were cultured with BMP4. At low density, the expression was the same throughout the chamber. However, at high density, SSEA-1 and BRACHYURY were expressed only in upstream cells, suggesting that some autocrine/paracrine factors inhibited the action of BMP4 in downstream cells to form the spatial pattern. Human iPSCs cultured in a perfusion culture chamber might be useful for studying in vitro macroscopic pattern formation in human embryogenesis. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Transparent polymeric cell culture chip with integrated temperature control and uniform media perfusion

    DEFF Research Database (Denmark)

    Petronis, Sarunas; Stangegaard, Michael; Christensen, C.

    2006-01-01

    Modern microfabrication and microfluidic technologies offer new opportunities in the design and fabrication of miniaturized cell culture systems for online monitoring of living cells. We used laser micromachining and thermal bonding to fabricate an optically transparent, low-cost polymeric chip...... for long-term online cell culture observation under controlled conditions. The chip incorporated a microfluidic flow equalization system, assuring uniform perfusion of the cell culture media throughout the cell culture chamber. The integrated indium-tin-oxide heater and miniature temperature probe linked....... HeLa cells were cultured for up to 2 weeks within the cell culture chip and monitored using a time-lapse video recording microscopy setup. Cell attachment and spreading was observed during the first 10-20 h (lag phase). After approximately 20 h, cell growth gained exponential character...

  8. Renal Cell Carcinoma Perfusion before and after Radiofrequency Ablation Measured with Dynamic Contrast Enhanced MRI: A Pilot Study.

    Science.gov (United States)

    Wah, Tze Min; Sourbron, Steven; Wilson, Daniel Jonathan; Magee, Derek; Gregory, Walter Martin; Selby, Peter John; Buckley, David L

    2018-01-08

    To investigate if the early treatment effects of radiofrequency ablation (RFA) on renal cell carcinoma (RCC) can be detected with dynamic contrast enhanced (DCE)-MRI and to correlate RCC perfusion with RFA treatment time. 20 patients undergoing RFA of their 21 RCCs were evaluated with DCE-MRI before and at one month after RFA treatment. Perfusion was estimated using the maximum slope technique at two independent sittings. Total RCC blood flow was correlated with total RFA treatment time, tumour location, size and histology. DCE-MRI examinations were successfully evaluated for 21 RCCs (size from 1.3 to 4 cm). Perfusion of the RCCs decreased significantly ( p measuring RCC perfusion before and after RFA. Perfusion significantly decreases in the zone of ablation, suggesting that it may be useful for the assessment of treatment efficacy. Pre-RFA RCC blood flow may be used to predict RFA treatment time.

  9. Simultaneous environmental manipulations in semi-perfusion cultures of CHO cells producing rh-tPA

    OpenAIRE

    Vergara,Mauricio; Becerra,Silvana; Díaz-Barrera,Alvaro; Berrios,Julio; Altamirano,Claudia

    2012-01-01

    We evaluated the combined effect of decreasing the temperature to a mild hypothermia range (34 and 31ºC) and switching to a slowly metabolizable carbon source (glucose substituted by galactose) on the growth and production of a recombinant human tissue plasminogen activator (rh-tPA) by Chinese hamster ovary cells in batch and semi-perfusion cultures. In batch cultures using glucose as a carbon source, decreasing the temperature caused a reduction in cell growth and an increase in specific pro...

  10. Universal lab-on-a-chip platform for complex, perfused 3D cell cultures

    Science.gov (United States)

    Sonntag, F.; Schmieder, F.; Ströbel, J.; Grünzner, S.; Busek, M.; Günther, K.; Steege, T.; Polk, C.; Klotzbach, U.

    2016-03-01

    The miniaturization, rapid prototyping and automation of lab-on-a-chip technology play nowadays a very important role. Lab-on-a-chip technology is successfully implemented not only for environmental analysis and medical diagnostics, but also as replacement of animals used for the testing of substances in the pharmaceutical and cosmetics industries. For that purpose the Fraunhofer IWS and partners developed a lab-on-a-chip platform for perfused cell-based assays in the last years, which includes different micropumps, valves, channels, reservoirs and customized cell culture modules. This technology is already implemented for the characterization of different human cell cultures and organoids, like skin, liver, endothelium, hair follicle and nephron. The advanced universal lab-on-a-chip platform for complex, perfused 3D cell cultures is divided into a multilayer basic chip with integrated micropump and application-specific 3D printed cell culture modules. Moreover a technology for surface modification of the printed cell culture modules by laser micro structuring and a complex and flexibly programmable controlling device based on an embedded Linux system was developed. A universal lab-on-a-chip platform with an optional oxygenator and a cell culture module for cubic scaffolds as well as first cell culture experiments within the cell culture device will be presented. The module is designed for direct interaction with robotic dispenser systems. This offers the opportunity to combine direct organ printing of cells and scaffolds with the microfluidic cell culture module. The characterization of the developed system was done by means of Micro-Particle Image Velocimetry (μPIV) and an optical oxygen measuring system.

  11. Particle image velocimetry (PIV) study of rotating cylindrical filters for animal cell perfusion processes.

    Science.gov (United States)

    Figueredo-Cardero, Alvio; Chico, Ernesto; Castilho, Leda; de Andrade Medronho, Ricardo

    2012-01-01

    In the present work, the main fluid flow features inside a rotating cylindrical filtration (RCF) system used as external cell retention device for animal cell perfusion processes were investigated using particle image velocimetry (PIV). The motivation behind this work was to provide experimental fluid dynamic data for such turbulent flow using a high-permeability filter, given the lack of information about this system in the literature. The results shown herein gave evidence that, at the boundary between the filter mesh and the fluid, a slip velocity condition in the tangential direction does exist, which had not been reported in the literature so far. In the RCF system tested, this accounted for a fluid velocity 10% lower than that of the filter tip, which could be important for the cake formation kinetics during filtration. Evidence confirming the existence of Taylor vortices under conditions of turbulent flow and high permeability, typical of animal cell perfusion RCF systems, was obtained. Second-order turbulence statistics were successfully calculated. The radial behavior of the second-order turbulent moments revealed that turbulence in this system is highly anisotropic, which is relevant for performing numerical simulations of this system. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

  12. Water permeability of acinar cell membranes in the isolated perfused rabbit mandibular salivary gland.

    Science.gov (United States)

    Steward, M C; Seo, Y; Rawlings, J M; Case, R M

    1990-01-01

    1. The diffusive water permeability of epithelial cell membranes in the perfused rabbit mandibular salivary gland was measured at 37 degrees C by a 1H nuclear magnetic resonance relaxation method using an extracellular relaxation reagent, gadolinium diethylenetriaminepentaacetic acid (Gd(DTPA)). 2. In glands perfused with a HEPES-buffered solution containing 10 mmol l-1 Gd(DTPA), the spin-lattice (T1) relaxation of the water protons showed two exponential components. The water compartment responsible for the slower component corresponded in magnitude to 71 +/- 5% of the wet weight of the gland, and was attributed to the exchangeable intracellular water of the acinar cells. 3. The rate constant for water efflux from the cells was estimated to be 4.1 +/- 0.1 s-1 which would be consistent with a diffusive membrane permeability (Pd) of approximately 3 x 10(-3) cm s-1. Stimulation with acetylcholine (10(-6) mol l-1) did not cause any detectable change in membrane water permeability. 4. Since the basolateral membrane probably provides the main pathway for water efflux, the osmotic water permeability of this barrier (expressed per gland) was estimated to be less than 6.2 cm3 s-1. This would be insufficient to account for the generation of a near-isosmotic fluid at the flow rates observed during secretion, and suggests that a substantial fraction of the flow of water occurs via a paracellular route. PMID:1966053

  13. Transcriptomics as a tool for assessing the scalability of mammalian cell perfusion systems.

    Science.gov (United States)

    Jayapal, Karthik P; Goudar, Chetan T

    2014-01-01

    DNA microarray-based transcriptomics have been used to determine the time course of laboratory and manufacturing-scale perfusion bioreactors in an attempt to characterize cell physiological state at these two bioreactor scales. Given the limited availability of genomic data for baby hamster kidney (BHK) cells, a Chinese hamster ovary (CHO)-based microarray was used following a feasibility assessment of cross-species hybridization. A heat shock experiment was performed using both BHK and CHO cells and resulting DNA microarray data were analyzed using a filtering criteria of perfect match (PM)/single base mismatch (MM) > 1.5 and PM-MM > 50 to exclude probes with low specificity or sensitivity for cross-species hybridizations. For BHK cells, 8910 probe sets (39 %) passed the cutoff criteria, whereas 12,961 probe sets (56 %) passed the cutoff criteria for CHO cells. Yet, the data from BHK cells allowed distinct clustering of heat shock and control samples as well as identification of biologically relevant genes as being differentially expressed, indicating the utility of cross-species hybridization. Subsequently, DNA microarray analysis was performed on time course samples from laboratory- and manufacturing-scale perfusion bioreactors that were operated under the same conditions. A majority of the variability (37 %) was associated with the first principal component (PC-1). Although PC-1 changed monotonically with culture duration, the trends were very similar in both the laboratory and manufacturing-scale bioreactors. Therefore, despite time-related changes to the cell physiological state, transcriptomic fingerprints were similar across the two bioreactor scales at any given instance in culture. Multiple genes were identified with time-course expression profiles that were very highly correlated (> 0.9) with bioprocess variables of interest. Although the current incomplete annotation limits the biological interpretation of these observations, their full potential may be

  14. The myocardial perfusion imaging of bone marrow mesenchymal stem cell transplantation treated acute myocardial infarction in pig

    International Nuclear Information System (INIS)

    He Miao; Hou Xiancun; Li Yaomei; Zhou Peng; Qi Chunmei; Wu Weihuan; Li Li

    2006-01-01

    Objective: To evaluate the clinical value of bone marrow mesenchymal stem cell transplantation on acute myocardial infarction in pig with myocardial perfusion imaging. Methods: Acute myocardial infarction models were established by 21 minitype Chinese pigs and were divided into two groups. After 10 days, experimental group (n=11) was transplanted with bone marrow mesenchymal stem cell at the infarct areas, and the control group (n=10) with incubation solution. Before and eight weeks after transplantation, both groups were examined by 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion imaging and with semi-quantitative analysis. Besides, echocardiogram and immunohistochemistry were also performed. Results: There was significant difference of total myocardial perfusion abnormal segments (46 vs 26), infarct areas [(34±12)% vs (21±10)%] and myocardial ischemia score [(20.0±4.3) vs (12.1±3.6)] between two groups (P<0.05). Also, there were accordant results with echocardiogram and immunohistochemistry findings. Conclusions: Bone marrow mesenchymal stem cell transplantation may improve blood perfusion and viability of the ischemic areas: Myocardial perfusion imaging can accurately observe the survival of bone marrow mesenchymal stem cell transplanted at the infarct areas. (authors)

  15. Flow perfusion culture of human mesenchymal stem cells on silicate-substituted tricalcium phosphate scaffolds

    DEFF Research Database (Denmark)

    Bjerre, Lea; Bünger, Cody E; Kassem, Moustapha

    2008-01-01

    Autologous bone grafts are currently the gold standard for treatment of large bone defects, but their availability is limited due to donor site morbidity. Different substitutes have been suggested to replace these grafts, and this study presents a bone tissue engineered alternative using silicate......-substituted tricalcium phosphate (Si-TCP) scaffolds seeded with human bone marrow-derived mesenchymal stem cells (hMSC). The cells were seeded onto the scaffolds and cultured either statically or in a perfusion bioreactor for up to 21 days and assessed for osteogenic differentiation by alkaline phosphatase activity...... assays and by quantitative real-time RT-PCR on bone markers. During culture, cells from the flow cultured constructs demonstrated improved proliferation and osteogenic differentiation verified by a more pronounced expression of several bone markers, e.g. alkaline phosphatase, osteopontin, Runx2, bone...

  16. Adipose-Derived Cell Construct Stabilizes Heart Function and Increases Microvascular Perfusion in an Established Infarct

    Science.gov (United States)

    Nguyen, Quang T.; Touroo, Jeremy S.; Aird, Allison L.; Chang, Raymond C.; Ng, Chin K.; Hoying, James B.; Williams, Stuart K.

    2013-01-01

    We have previously shown that myocardial infarction (MI) immediately treated with an epicardial construct containing stromal vascular fraction (SVF) from adipose tissue preserved microvascular function and left ventricle contractile mechanisms. In order to evaluate a more clinically relevant condition, we investigated the cardiac recovery potential of an SVF construct implanted onto an established infarct. SVF cells were isolated from rat adipose tissue, plated on Vicryl, and cultured for 14 days. Fischer-344 rats were separated into MI groups: (a) 6-week MI (MI), (b) 6-week MI treated with an SVF construct at 2 weeks (MI SVF), (c) 6-week MI with Vicryl construct at 2 weeks (MI Vicryl), and (d) MI 2wk (time point of intervention). Emax, an indicator of systolic performance and contractile function, was lower in the MI and MI Vicryl versus MI SVF. Positron emission tomography imaging (18F-fluorodeoxyglucose) revealed a decreased percentage of relative infarct volume in the MI SVF versus MI and MI Vicryl. Total vessel count and percentage of perfusion assessed via immunohistochemistry were both increased in the infarct region of MI SVF versus MI and MI Vicryl. Overall cardiac function, percentage of relative infarct, and percentage of perfusion were similar between MI SVF and MI 2wk; however, total vessel count increased after SVF treatment. These data suggest that SVF treatment of an established infarct stabilizes the heart at the time point of intervention by preventing a worsening of cardiac performance and infarcted volume, and is associated with increased microvessel perfusion in the area of established infarct. PMID:24106337

  17. Transport and phosphorylation of choline in higher plant cells. Phosphorus-31 nuclear magnetic resonance studies

    Energy Technology Data Exchange (ETDEWEB)

    Bligny, R.; Foray, M.F.; Roby, C.; Douce, R.

    1989-03-25

    When sycamore cells were suspended in basal medium containing choline, the latter was taken up by the cells very rapidly. A facilitated diffusion system appertained at low concentrations of choline and exhibited Michaelis-Menten kinetics. At higher choline concentrations simple diffusion appeared to be the principal mode of uptake. Addition of choline to the perfusate of compressed sycamore cells monitored by /sup 31/P NMR spectroscopy resulted in a dramatic accumulation of P-choline in the cytoplasmic compartment containing choline kinase and not in the vacuole. The total accumulation of P-choline over a 10-h period exhibited Michaelis-Menten kinetics. During this period, in the absence of Pi in the perfusion medium there was a marked depletion of glucose-6-P, and the cytoplasmic Pi resonance disappeared almost completely. When a threshold of cytoplasmic Pi was attained, the phosphorylation of choline was sustained by the continuous release of Pi from the vacuole although at a much lower rate. However, when 100 microM inorganic phosphate was present in the perfusion medium, externally added Pi was preferentially used to sustain P-choline synthesis. It is clear, therefore, that cytosolic choline kinase associated with a carrier-mediated transport system for choline uptake appeared as effective systems for continuously trapping cytoplasmic Pi including vacuolar Pi entering the cytoplasm.

  18. Albumin modulates S1P delivery from red blood cells in perfused microvessels: mechanism of the protein effect.

    Science.gov (United States)

    Adamson, R H; Clark, J F; Radeva, M; Kheirolomoom, A; Ferrara, K W; Curry, F E

    2014-04-01

    Removal of plasma proteins from perfusates increases vascular permeability. The common interpretation of the action of albumin is that it forms part of the permeability barrier by electrostatic binding to the endothelial glycocalyx. We tested the alternate hypothesis that removal of perfusate albumin in rat venular microvessels decreased the availability of sphingosine-1-phosphate (S1P), which is normally carried in plasma bound to albumin and lipoproteins and is required to maintain stable baseline endothelial barriers (Am J Physiol Heart Circ Physiol 303: H825-H834, 2012). Red blood cells (RBCs) are a primary source of S1P in the normal circulation. We compared apparent albumin permeability coefficients [solute permeability (Ps)] measured using perfusates containing albumin (10 mg/ml, control) and conditioned by 20-min exposure to rat RBCs with Ps when test perfusates were in RBC-conditioned protein-free Ringer solution. The control perfusate S1P concentration (439 ± 46 nM) was near the normal plasma value at 37 °C and established a stable baseline Ps (0.9 ± 0.4 × 10(-6) cm/s). Ringer solution perfusate contained 52 ± 8 nM S1P and increased Ps more than 10-fold (16.1 ± 3.9 × 10(-6) cm/s). Consistent with albumin-dependent transport of S1P from RBCs, S1P concentrations in RBC-conditioned solutions decreased as albumin concentration, hematocrit, and temperature decreased. Protein-free Ringer solution perfusates that used liposomes instead of RBCs as flow markers failed to maintain normal permeability, reproducing the "albumin effect" in these mammalian microvessels. We conclude that the albumin effect depends on the action of albumin to facilitate the release and transport of S1P from RBCs that normally provide a significant amount of S1P to the endothelium.

  19. Renal Cell Carcinoma Perfusion before and after Radiofrequency Ablation Measured with Dynamic Contrast Enhanced MRI: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Tze Min Wah

    2018-01-01

    Full Text Available Aim: To investigate if the early treatment effects of radiofrequency ablation (RFA on renal cell carcinoma (RCC can be detected with dynamic contrast enhanced (DCE-MRI and to correlate RCC perfusion with RFA treatment time. Materials and methods: 20 patients undergoing RFA of their 21 RCCs were evaluated with DCE-MRI before and at one month after RFA treatment. Perfusion was estimated using the maximum slope technique at two independent sittings. Total RCC blood flow was correlated with total RFA treatment time, tumour location, size and histology. Results: DCE-MRI examinations were successfully evaluated for 21 RCCs (size from 1.3 to 4 cm. Perfusion of the RCCs decreased significantly (p < 0.0001 from a mean of 203 (±80 mL/min/100 mL before RFA to 8.1 (±3.1 mL/min/100 mL after RFA with low intra-observer variability (r ≥ 0.99, p < 0.0001. There was an excellent correlation (r = 0.95 between time to complete ablation and pre-treatment total RCC blood flow. Tumours with an exophytic location exhibit the lowest mean RFA treatment time. Conclusion: DCE-MRI can detect early treatment effects by measuring RCC perfusion before and after RFA. Perfusion significantly decreases in the zone of ablation, suggesting that it may be useful for the assessment of treatment efficacy. Pre-RFA RCC blood flow may be used to predict RFA treatment time.

  20. Mesenchymal Stromal Cells as Anti-Inflammatory and Regenerative Mediators for Donor Kidneys During Normothermic Machine Perfusion.

    Science.gov (United States)

    Sierra-Parraga, Jesus Maria; Eijken, Marco; Hunter, James; Moers, Cyril; Leuvenink, Henri; Møller, Bjarne; Ploeg, Rutger J; Baan, Carla C; Jespersen, Bente; Hoogduijn, Martin J

    2017-08-15

    There is great demand for transplant kidneys for the treatment of end-stage kidney disease patients. To expand the donor pool, organs from older and comorbid brain death donors, so-called expanded criteria donors (ECD), as well as donation after circulatory death donors, are considered for transplantation. However, the quality of these organs may be inferior to standard donor organs. A major issue affecting graft function and survival is ischemia/reperfusion injury, which particularly affects kidneys from deceased donors. The development of hypothermic machine perfusion has been introduced in kidney transplantation as a preservation technique and has improved outcomes in ECD and marginal organs compared to static cold storage. Normothermic machine perfusion (NMP) is the most recent evolution of perfusion technology and allows assessment of the donor organ before transplantation. The possibility to control the content of the perfusion fluid offers opportunities for damage control and reparative therapies during machine perfusion. Mesenchymal stromal cells (MSC) have been demonstrated to possess potent regenerative properties via the release of paracrine effectors. The combination of NMP and MSC administration at the same time is a promising procedure in the field of transplantation. Therefore, the MePEP consortium has been created to study this novel modality of treatment in preparation for human trials. MePEP aims to assess the therapeutic effects of MSC administered ex vivo by NMP in the mechanisms of injury and repair in a porcine kidney autotransplantation model.

  1. Modulation and modeling of monoclonal antibody N-linked glycosylation in mammalian cell perfusion reactors.

    Science.gov (United States)

    Karst, Daniel J; Scibona, Ernesto; Serra, Elisa; Bielser, Jean-Marc; Souquet, Jonathan; Stettler, Matthieu; Broly, Hervé; Soos, Miroslav; Morbidelli, Massimo; Villiger, Thomas K

    2017-09-01

    Mammalian cell perfusion cultures are gaining renewed interest as an alternative to traditional fed-batch processes for the production of therapeutic proteins, such as monoclonal antibodies (mAb). The steady state operation at high viable cell density allows the continuous delivery of antibody product with increased space-time yield and reduced in-process variability of critical product quality attributes (CQA). In particular, the production of a confined mAb N-linked glycosylation pattern has the potential to increase therapeutic efficacy and bioactivity. In this study, we show that accurate control of flow rates, media composition and cell density of a Chinese hamster ovary (CHO) cell perfusion bioreactor allowed the production of a constant glycosylation profile for over 20 days. Steady state was reached after an initial transition phase of 6 days required for the stabilization of extra- and intracellular processes. The possibility to modulate the glycosylation profile was further investigated in a Design of Experiment (DoE), at different viable cell density and media supplement concentrations. This strategy was implemented in a sequential screening approach, where various steady states were achieved sequentially during one culture. It was found that, whereas high ammonia levels reached at high viable cell densities (VCD) values inhibited the processing to complex glycan structures, the supplementation of either galactose, or manganese as well as their synergy significantly increased the proportion of complex forms. The obtained experimental data set was used to compare the reliability of a statistical response surface model (RSM) to a mechanistic model of N-linked glycosylation. The latter outperformed the response surface predictions with respect to its capability and reliability in predicting the system behavior (i.e., glycosylation pattern) outside the experimental space covered by the DoE design used for the model parameter estimation. Therefore, we can

  2. Evaluation of mechanical and morphologic features of PLLA membranes as supports for perfusion cells culture systems

    Energy Technology Data Exchange (ETDEWEB)

    Montesanto, S., E-mail: salvatore.montesanto1985@gmail.com [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); Brucato, V. [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); La Carrubba, V. [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); Euro-Mediterranean Institute of Science and Technology (IEMEST), Via Michele Miraglia, 20, 90128 Palermo (Italy)

    2016-12-01

    Porous biodegradable PLLA membranes, which can be used as supports for perfusion cell culture systems were designed, developed and characterized. PLLA membranes were prepared via diffusion induced phase separation (DIPS). A glass slab was coated with a binary PLLA–dioxane solution (8 wt.% PLLA) via dip coating, then pool immersed in two subsequent coagulation baths, and finally dried in a humidity-controlled environment. Surface and mechanical properties were evaluated by measuring pore size, porosity via scanning electron microscopy, storage modulus, loss modulus and loss angle by using a dynamic mechanical analysis (DMA). Cell adhesion assays on different membrane surfaces were also performed by using a standard count method. Results provide new insights into the foaming methods for producing polymeric membranes and supply indications on how to optimise the fabrication parameters to design membranes for tissue cultures and regeneration. - Highlights: • Design, development and characterization of porous biodegradable PLLA membranes via DIPS technology. • Easy-to-tune processing parameters in terms of surface and volumetric properties and cell adhesion. • Evaluation of the impact of the interconnection degree on membrane's mechanical properties. • Evaluation of cell adhesion on different membrane surface textures.

  3. Evaluation of mechanical and morphologic features of PLLA membranes as supports for perfusion cells culture systems

    International Nuclear Information System (INIS)

    Montesanto, S.; Brucato, V.; La Carrubba, V.

    2016-01-01

    Porous biodegradable PLLA membranes, which can be used as supports for perfusion cell culture systems were designed, developed and characterized. PLLA membranes were prepared via diffusion induced phase separation (DIPS). A glass slab was coated with a binary PLLA–dioxane solution (8 wt.% PLLA) via dip coating, then pool immersed in two subsequent coagulation baths, and finally dried in a humidity-controlled environment. Surface and mechanical properties were evaluated by measuring pore size, porosity via scanning electron microscopy, storage modulus, loss modulus and loss angle by using a dynamic mechanical analysis (DMA). Cell adhesion assays on different membrane surfaces were also performed by using a standard count method. Results provide new insights into the foaming methods for producing polymeric membranes and supply indications on how to optimise the fabrication parameters to design membranes for tissue cultures and regeneration. - Highlights: • Design, development and characterization of porous biodegradable PLLA membranes via DIPS technology. • Easy-to-tune processing parameters in terms of surface and volumetric properties and cell adhesion. • Evaluation of the impact of the interconnection degree on membrane's mechanical properties. • Evaluation of cell adhesion on different membrane surface textures.

  4. Teratoma formation of human embryonic stem cells in three-dimensional perfusion culture bioreactors.

    Science.gov (United States)

    Stachelscheid, H; Wulf-Goldenberg, A; Eckert, K; Jensen, J; Edsbagge, J; Björquist, P; Rivero, M; Strehl, R; Jozefczuk, J; Prigione, A; Adjaye, J; Urbaniak, T; Bussmann, P; Zeilinger, K; Gerlach, J C

    2013-09-01

    Teratoma formation in mice is today the most stringent test for pluripotency that is available for human pluripotent cells, as chimera formation and tetraploid complementation cannot be performed with human cells. The teratoma assay could also be applied for assessing the safety of human pluripotent cell-derived cell populations intended for therapeutic applications. In our study we examined the spontaneous differentiation behaviour of human embryonic stem cells (hESCs) in a perfused 3D multi-compartment bioreactor system and compared it with differentiation of hESCs and human induced pluripotent cells (hiPSCs) cultured in vitro as embryoid bodies and in vivo in an experimental mouse model of teratoma formation. Results from biochemical, histological/immunohistological and ultrastuctural analyses revealed that hESCs cultured in bioreactors formed tissue-like structures containing derivatives of all three germ layers. Comparison with embryoid bodies and the teratomas revealed a high degree of similarity of the tissues formed in the bioreactor to these in the teratomas at the histological as well as transcriptional level, as detected by comparative whole-genome RNA expression profiling. The 3D culture system represents a novel in vitro model that permits stable long-term cultivation, spontaneous multi-lineage differentiation and tissue formation of pluripotent cells that is comparable to in vivo differentiation. Such a model is of interest, e.g. for the development of novel cell differentiation strategies. In addition, the 3D in vitro model could be used for teratoma studies and pluripotency assays in a fully defined, controlled environment, alternatively to in vivo mouse models. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Optimising cell aggregate expansion in a perfused hollow fibre bioreactor via mathematical modelling.

    KAUST Repository

    Chapman, Lloyd A C; Shipley, Rebecca J; Whiteley, Jonathan P; Ellis, Marianne J; Byrne, Helen M; Waters, Sarah L

    2014-01-01

    , the higher fluid shear stress can lead to cell death. For a given cell type and initial aggregate distribution, the operating parameters that give the most rapid overall growth can be identified from simulations. For example, when aggregates of rat

  6. Flow-perfusion interferes with chondrogenic and hypertrophic matrix production by mesenchymal stem cells

    NARCIS (Netherlands)

    Kock, Linda M; Malda, Jos; Dhert, Wouter J A; Ito, Keita; Gawlitta, Debby

    2014-01-01

    Flow-perfusion is being promoted as a way to grow tissue-engineered cartilage in vitro. Yet, there is a concern that flow-perfusion may induce unwanted mechanical effects on chondrogenesis and terminal differentiation. Therefore, the aim of this study is to evaluate the effect of fluid flow on

  7. Normal LVEF measurements are significantly higher in females asassessed by post-stress resting Tc-99m sestamibi gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Kim, Jong Ho; Shin, Eak Kyun

    1999-01-01

    Volume-LVEF relationship is one of the most important factors of automatic EF quantification algorithm from gated myocardial perfusion SPECT(gMPS) (Germano et al. JNM, 1995). Gender difference whereby normal LVEF measurements are higher in females assessed by gMPS (Yao et al. JNM 1997). To validate true physiologic value of LVEF vs sampling or measured error, various parameters were evaluated statistically in both gender and age matched 200 subjects (mean age= 58.41±15.01) with normal LVEF more than 50%, and a low likelihood of coronary artery disease. Correlation between LVEDVi(ml/m2) and LVEF was highly significant (r=-0.62, p<0.0001) with similar correlations noted in both male (r=-0.45, p<0.0001) and female (r=-0.67, p<0.0001) subgroups. By multivariate analysis, LV volume and stroke volume was the most significant factor influencing LVEF in male and female, respectively. In conclusion, there is a significant negative correlation between LV volume and LVEF as measured by Tc-99m gated SPECT. Higher normal LVEF value should be applied to females as assessed by post-stress resting Tc-99m Sestamibi gated myocardial perfusion SPECT

  8. Comparison of parathyroid hormone and G-CSF treatment after myocardial infarction on perfusion and stem cell homing.

    Science.gov (United States)

    Huber, Bruno C; Fischer, Rebekka; Brunner, Stefan; Groebner, Michael; Rischpler, Christoph; Segeth, Alexander; Zaruba, Marc M; Wollenweber, Tim; Hacker, Marcus; Franz, Wolfgang-Michael

    2010-05-01

    Mobilization of stem cells by granulocyte colony-stimulating factor (G-CSF) was shown to have protective effects after myocardial infarction (MI); however, clinical trials failed to be effective. In search for alternative cytokines, parathyroid hormone (PTH) was recently shown to promote cardiac repair by enhanced neovascularization and cell survival. To compare the impact of the two cytokines G-CSF and PTH on myocardial perfusion, mice were noninvasively and repetitively investigated by pinhole single-photon emission computed tomography (SPECT) after MI. Mobilization and homing of bone marrow-derived stem cells (BMCs) was analyzed by fluorescence-activated cell sorter (FACS) analysis. Mice (C57BL/6J) were infarcted by left anterior descending artery ligation. PTH (80 mug/kg) and G-CSF (100 mug/kg) were injected for 5 days. Perfusion defects were determined by (99m)Tc-sestamibi SPECT at days 6 and 30 after MI. The number of BMCs characterized by Lin(-)/Sca-1(+)/c-kit(+) cells in peripheral blood and heart was analyzed by FACS. Both G-CSF and PTH treatment resulted in an augmented mobilization of BMCs in the peripheral blood. Contrary to G-CSF and controls, PTH and the combination showed significant migration of BMCs in ischemic myocardium associated with a significant reduction of perfusion defects from day 6 to day 30. A combination of both cytokines had no additional effects on migration and perfusion. In our preclinical model, SPECT analyses revealed the functional potential of PTH reducing size of infarction together with an enhanced homing of BMCs to the myocardium in contrast to G-CSF. A combination of both cytokines did not improve the functional outcome, suggesting clinical applications of PTH in ischemic heart diseases.

  9. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

  10. Extracellular Vesicles from Human Liver Stem Cells Reduce Injury in an Ex Vivo Normothermic Hypoxic Rat Liver Perfusion Model.

    Science.gov (United States)

    Rigo, Federica; De Stefano, Nicola; Navarro-Tableros, Victor; David, Ezio; Rizza, Giorgia; Catalano, Giorgia; Gilbo, Nicholas; Maione, Francesca; Gonella, Federica; Roggio, Dorotea; Martini, Silvia; Patrono, Damiano; Salizzoni, Mauro; Camussi, Giovanni; Romagnoli, Renato

    2018-05-01

    The gold standard for organ preservation before transplantation is static cold storage, which is unable to fully protect suboptimal livers from ischemia/reperfusion injury. An emerging alternative is normothermic machine perfusion (NMP), which permits organ reconditioning. Here, we aimed to explore the feasibility of a pharmacological intervention on isolated rat livers by using a combination of NMP and human liver stem cells-derived extracellular vesicles (HLSC-EV). We established an ex vivo murine model of NMP capable to maintain liver function despite an ongoing hypoxic injury induced by hemodilution. Livers were perfused for 4 hours without (control group, n = 10) or with HLSC-EV (treated group, n = 9). Bile production was quantified; perfusate samples were collected hourly to measure metabolic (pH, pO2, pCO2) and cytolysis parameters (AST, alanine aminotransferase, lactate dehydrogenase). At the end of perfusion, we assessed HLSC-EV engraftment by immunofluorescence, tissue injury by histology, apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, tissue hypoxia-inducible factor 1-α, and transforming growth factor-beta 1 RNA expression by quantitative reverse transcription-polymerase chain reaction. During hypoxic NMP, livers were able to maintain homeostasis and produce bile. In the treated group, AST (P = 0.018) and lactate dehydrogenase (P = 0.032) levels were significantly lower than those of the control group at 3 hours of perfusion, and AST levels persisted lower at 4 hours (P = 0.003). By the end of NMP, HLSC-EV had been uptaken by hepatocytes, and EV treatment significantly reduced histological damage (P = 0.030), apoptosis (P = 0.049), and RNA overexpression of hypoxia-inducible factor 1-α (P < 0.0001) and transforming growth factor-beta 1 (P = 0.014). HLSC-EV treatment, even in a short-duration model, was feasible and effectively reduced liver injury during hypoxic NMP.

  11. Whole tumour first-pass perfusion using a low-dose method with 64-section multidetector row computed tomography in oesophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Chen Tianwu; Yang Zhigang; Dong Zhihui; Li Yuan; Yao Jin; Wang Qiling; Qian Lingling

    2011-01-01

    Purpose: To propose a low-dose method at tube current-time product of 50 mAs for whole tumour first-pass perfusion of oesophageal squamous cell carcinoma using 64-section multidetector row computed tomography (MDCT), and to assess the original image quality and accuracy of perfusion parameters. Materials and methods: Fifty-nine consecutive patients with confirmed oesophageal squamous cell carcinomas were enrolled into our study, and underwent whole tumour first-pass perfusion scan with 64-section MDCT at 50 mAs. Image data were statistically reviewed focusing on original image quality demonstrated by image-quality scores and signal-to-noise (S/N) ratios; and perfusion parameters including perfusion (PF, in ml/min/ml), peak enhanced density (PED, in HU), time to peak (TTP, in seconds) and blood volume (BV, in ml/100 g) for the tumour. To test the interobserver agreement of perfusion measurements, perfusion analyses were repeatedly performed. Results: Original image-quality scores were 4.71 ± 0.49 whereas S/N ratios were 5.21 ± 2.05, and the scores were correlated with the S/N ratios (r = 0.465, p < 0.0001). Mean values for PF, PED, TTP and BV of the tumour were 33.27 ± 24.15 ml/min/ml, 24.06 ± 9.87 HU, 29.42 ± 8.61 s, and 12.45 ± 12.22 ml/100 g, respectively. Intraclass correlation coefficient between the replicated measurements of each perfusion parameter was greater than 0.99, and mean difference of the replicated measurements of each parameter was close to zero. Conclusion: Whole tumour first-pass perfusion with 64-section MDCT at low-dose radiation could be reproducible to assess microcirculation in oesophageal squamous cell carcinoma without compromising subjective original image quality of the tumour.

  12. An axial distribution of seeding, proliferation, and osteogenic differentiation of MC3T3-E1 cells and rat bone marrow-derived mesenchymal stem cells across a 3D Thai silk fibroin/gelatin/hydroxyapatite scaffold in a perfusion bioreactor

    Energy Technology Data Exchange (ETDEWEB)

    Sinlapabodin, Salita; Amornsudthiwat, Phakdee; Damrongsakkul, Siriporn; Kanokpanont, Sorada, E-mail: sorada.k@chula.ac.th

    2016-01-01

    In cell culture, a perfusion bioreactor provides effective transportation of nutrients, oxygen, and waste removal to and from the core of the scaffold. In addition, it provides mechanical stimuli for enhancing osteogenic differentiation. In this study, we used an axial distribution of cell numbers, alkaline phosphatase (ALP) enzyme activity, and calcium content across 4 cross-sections of 10 mm thick scaffold, made of Thai silk fibroin (SF)/gelatin (G)/hydroxyapatite (HA), as a tool to evaluate the suitable perfusion flow rate. These evaluations cover all cellular developmental phases starting from seeding, to proliferation, and later osteogenic differentiation. Mouse pre-osteoblastic MC3T3-E1 cell lines were used as a cell model during seeding and proliferation. The bioreactor seeded scaffold provided more uniform cell distribution across the scaffold compared to centrifugal and agitation seeding, while the overall number of adhered cells from bioreactor seeding was slightly lower than agitation seeding. The dynamic culture using 1 ml/min perfusion flow rate (initial shear stress of 0.1 dyn/cm{sup 2}) enabled statistically higher MC3T3-E1 proliferation, ALP activity, and calcium deposition than those observed in the static-culturing condition. However, the perfusion flow rate of 1 ml/min seemed not to be enough for enhancing ALP expression across all sections of the scaffold. Rat bone marrow derived stromal cells (rMSC) were used in the detachment test and osteogenic differentiation. It was found that perfusion flow rate of 5 ml/min caused statistically higher cell detachment than that of 1 and 3 ml/min. The perfusion flow rate of 3 ml/min gave the highest rMSC osteogenic differentiation on a SF/G/HA scaffold than other flow rates, as observed from the significantly highest number of ALP enzyme activity and the calcium content without any significant cell growth. In addition, all of these parameters were evenly distributed across all scaffold sections. - Highlights

  13. Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused 3D Porous Polymer Scaffold for Liver Tissue Engineering

    DEFF Research Database (Denmark)

    Hemmingsen, Mette; Muhammad, Haseena Bashir; Mohanty, Soumyaranjan

    A huge shortage of liver organs for transplantation has motivated the research field of tissue engineering to develop bioartificial liver tissue and even a whole liver. The goal of NanoBio4Trans is to create a vascularized bioartificial liver tissue, initially as a liver-support system. Due...... to limitations of primary hepatocytes regarding availability and maintenance of functionality, stem cells and especially human induced pluripotent stem cells (hIPS cells) are an attractive cell source for liver tissue engineering. The aim of this part of NanoBio4Trans is to optimize culture and hepatic...... differentiation of hIPS-derived definitive endoderm (DE) cells in a 3D porous polymer scaffold built-in a perfusable bioreactor. The use of a microfluidic bioreactor array enables the culture of 16 independent tissues in one experimental run and thereby an optimization study to be performed....

  14. Time-resolved, single-cell analysis of induced and programmed cell death via non-invasive propidium iodide and counterstain perfusion.

    Science.gov (United States)

    Krämer, Christina E M; Wiechert, Wolfgang; Kohlheyer, Dietrich

    2016-09-01

    Conventional propidium iodide (PI) staining requires the execution of multiple steps prior to analysis, potentially affecting assay results as well as cell vitality. In this study, this multistep analysis method has been transformed into a single-step, non-toxic, real-time method via live-cell imaging during perfusion with 0.1 μM PI inside a microfluidic cultivation device. Dynamic PI staining was an effective live/dead analytical tool and demonstrated consistent results for single-cell death initiated by direct or indirect triggers. Application of this method for the first time revealed the apparent antibiotic tolerance of wild-type Corynebacterium glutamicum cells, as indicated by the conversion of violet fluorogenic calcein acetoxymethyl ester (CvAM). Additional implementation of this method provided insight into the induced cell lysis of Escherichia coli cells expressing a lytic toxin-antitoxin module, providing evidence for non-lytic cell death and cell resistance to toxin production. Finally, our dynamic PI staining method distinguished necrotic-like and apoptotic-like cell death phenotypes in Saccharomyces cerevisiae among predisposed descendants of nutrient-deprived ancestor cells using PO-PRO-1 or green fluorogenic calcein acetoxymethyl ester (CgAM) as counterstains. The combination of single-cell cultivation, fluorescent time-lapse imaging, and PI perfusion facilitates spatiotemporally resolved observations that deliver new insights into the dynamics of cellular behaviour.

  15. A perfusion culture system using a stirred ceramic membrane reactor for hyperproduction of IgG2a monoclonal antibody by hybridoma cells.

    Science.gov (United States)

    Dong, Haodi; Tang, Ya-Jie; Ohashi, Ryo; Hamel, Jean-François P

    2005-01-01

    A novel perfusion culture system for efficient production of IgG2a monoclonal antibody (mAb) by hybridoma cells was developed. A ceramic membrane module was constructed and used as a cell retention device installed in a conventional stirred-tank reactor during the perfusion culture. Furthermore, the significance of the control strategy of perfusion rate (volume of fresh medium/working volume of reactor/day, vvd) was investigated. With the highest increasing rate (deltaD, vvd per day, vvdd) of perfusion rate, the maximal viable cell density of 3.5 x 10(7) cells/mL was obtained within 6 days without any limitation and the cell viability was maintained above 95%. At lower deltaD's, the cell growth became limited. Under nutrient-limited condition, the specific cell growth rate (mu) was regulated by deltaD. During the nonlimited growth phase, the specific mAb production rate (qmAb) remained constant at 0.26 +/- 0.02 pg/cell x h in all runs. During the cell growth-limited phase, qmAb was regulated by deltaD within the range of 0.25-0.65 vvdd. Under optimal conditions, qmAb of 0.80 and 2.15 pg/cell x h was obtained during the growth-limited phase and stationary phase, respectively. The overall productivity and yield were 690 mg/L x day and 340 mg/L x medium, respectively. This study demonstrated that this novel perfusion culture system for suspension mammalian cells can support high cell density and efficient mAb production and that deltaD is an important control parameter to regulate and achieve high mAb production.

  16. The influence of intraoperative pleural perfusion with matrine-cisplatin or cisplatin on stromal cell-derived factor-1 in non-small cell lung cancer patients with subclinical pleural metastasis.

    Science.gov (United States)

    Yang, Cheng-Liang; Liu, Shun-Shou; Ma, Ye-Gang; Liu, Yong-Yu; Xue, Yi-Xue; Huang, Bo

    2012-06-01

    The early diagnosis and treatment of non-small cell lung cancer (NSCLC) in patients with subclinical pleural metastasis is currently a challenge. In an effort to establish a method for the diagnosis and treatment of these patients, we conducted a single-blind study during which intraoperative pleural lavage cytology (PLC) was performed in 164 patients with NSCLC without obvious pleural effusion. Stromal cell-derived factor-1 (SDF-1) serum concentrations were analyzed using enzyme-linked immunoassay on day 1 prior to tumor resection and on day 7 postoperatively. Western blot analysis was used for the detection of CXCR4 protein expression in resected tumors. Intraoperative pleural perfusion chemotherapy, with either cisplatin or cisplatin plus matrine, was given to patients with positive PLC. A group of 30 patients with NSCLC that did not undergo intraoperative PLC were used as a control group. Of the 164 study patients, 41 (25%) patients had positive PLC. Serum SDF-1 concentrations were higher in PLC-positive patients compared with patients negative for PLC and control patients. Serum SDF-1 concentrations were also lower at postoperative day 7 in patients treated with cisplatin plus matrine compared with control patients and those perfused with cisplatin alone. A lower incidence of chemotherapy-related adverse events was observed in patients treated with cisplatin plus matrine versus those treated with cisplatin alone during the first postoperative month. Patients with positive PLC showed a higher CXCR4 protein expression than patients with negative PLC. Based on the results of this study, PLC combined with serum SDF-1 concentration measurements may be considered as an effective index to determine the risk of subclinical pleural metastasis in patients with lung cancer. In addition, cisplatin plus matrine was confirmed as an initial approach for pleural perfusion and was superior to cisplatin alone.

  17. Renal perfusion scintiscan

    Science.gov (United States)

    ... Radionuclide renal perfusion scan; Perfusion scintiscan - renal; Scintiscan - renal perfusion Images Kidney anatomy Kidney - blood and urine flow Intravenous pyelogram References Rottenberg G, Andi AC. Renal ...

  18. Optimising cell aggregate expansion in a perfused hollow fibre bioreactor via mathematical modelling.

    KAUST Repository

    Chapman, Lloyd A C

    2014-08-26

    The need for efficient and controlled expansion of cell populations is paramount in tissue engineering. Hollow fibre bioreactors (HFBs) have the potential to meet this need, but only with improved understanding of how operating conditions and cell seeding strategy affect cell proliferation in the bioreactor. This study is designed to assess the effects of two key operating parameters (the flow rate of culture medium into the fibre lumen and the fluid pressure imposed at the lumen outlet), together with the cell seeding distribution, on cell population growth in a single-fibre HFB. This is achieved using mathematical modelling and numerical methods to simulate the growth of cell aggregates along the outer surface of the fibre in response to the local oxygen concentration and fluid shear stress. The oxygen delivery to the cell aggregates and the fluid shear stress increase as the flow rate and pressure imposed at the lumen outlet are increased. Although the increased oxygen delivery promotes growth, the higher fluid shear stress can lead to cell death. For a given cell type and initial aggregate distribution, the operating parameters that give the most rapid overall growth can be identified from simulations. For example, when aggregates of rat cardiomyocytes that can tolerate shear stresses of up to 0:05 Pa are evenly distributed along the fibre, the inlet flow rate and outlet pressure that maximise the overall growth rate are predicted to be in the ranges 2.75 x 10(-5) m(2) s(-1) to 3 x 10(-5) m(2) s(-1) (equivalent to 2.07 ml min(-1) to 2.26 ml min(-1)) and 1.077 x 10(5) Pa to 1.083 x 10(5) Pa (or 15.6 psi to 15.7 psi) respectively. The combined effects of the seeding distribution and flow on the growth are also investigated and the optimal conditions for growth found to depend on the shear tolerance and oxygen demands of the cells.

  19. Expansion of Bone Marrow Mesenchymal Stromal Cells in Perfused 3D Ceramic Scaffolds Enhances In Vivo Bone Formation.

    Science.gov (United States)

    Hoch, Allison I; Duhr, Ralph; Di Maggio, Nunzia; Mehrkens, Arne; Jakob, Marcel; Wendt, David

    2017-12-01

    Bone marrow-derived mesenchymal stromal cells (BMSC), when expanded directly within 3D ceramic scaffolds in perfusion bioreactors, more reproducibly form bone when implanted in vivo as compared to conventional expansion on 2D polystyrene dishes/flasks. Since the bioreactor-based expansion on 3D ceramic scaffolds encompasses multiple aspects that are inherently different from expansion on 2D polystyrene, we aimed to decouple the effects of specific parameters among these two model systems. We assessed the effects of the: 1) 3D scaffold vs. 2D surface; 2) ceramic vs. polystyrene materials; and 3) BMSC niche established within the ceramic pores during in vitro culture, on subsequent in vivo bone formation. While BMSC expanded on 3D polystyrene scaffolds in the bioreactor could maintain their in vivo osteogenic potential, results were similar as BMSC expanded in monolayer on 2D polystyrene, suggesting little influence of the scaffold 3D environment. Bone formation was most reproducible when BMSC are expanded on 3D ceramic, highlighting the influence of the ceramic substrate. The presence of a pre-formed niche within the scaffold pores had negligible effects on the in vivo bone formation. The results of this study allow a greater understanding of the parameters required for perfusion bioreactor-based manufacturing of osteogenic grafts for clinical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A potential to reduce pulmonary toxicity: The use of perfusion SPECT with IMRT for functional lung avoidance in radiotherapy of non-small cell lung cancer

    International Nuclear Information System (INIS)

    Lavrenkov, Konstantin; Christian, Judith A.; Partridge, Mike; Niotsikou, Elena; Cook, Gary; Parker, Michelle; Bedford, James L.; Brada, Michael

    2007-01-01

    Background and purpose: The study aimed to examine specific avoidance of functional lung (FL) defined by a single photon emission computerized tomography (SPECT) lung perfusion scan, using intensity modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3-DCRT) in patients with non-small cell lung cancer (NSCLC). Materials and methods: Patients with NSCLC underwent planning computerized tomography (CT) and lung perfusion SPECT scan in the treatment position using fiducial markers to allow co-registration in the treatment planning system. Radiotherapy (RT) volumes were delineated on the CT scan. FL was defined using co-registered SPECT images. Two inverse coplanar RT plans were generated for each patient: 4-field 3-DCRT and 5-field step-and-shoot IMRT. 3-DCRT plans were created using automated AutoPlan optimisation software, and IMRT plans were generated employing Pinnacle 3 treatment planning system (Philips Radiation Oncology Systems). All plans were prescribed to 64 Gy in 32 fractions using data for the 6 MV beam from an Elekta linear accelerator. The objectives for both plans were to minimize the volume of FL irradiated to 20 Gy (fV 20 ) and dose variation within the planning target volume (PTV). A spinal cord dose was constrained to 46 Gy. Volume of PTV receiving 90% of the prescribed dose (PTV 90 ), fV 20 , and functional mean lung dose (fMLD) were recorded. The PTV 90 /fV 20 ratio was used to account for variations in both measures, where a higher value represented a better plan. Results: Thirty-four RT plans of 17 patients with stage I-IIIB NSCLC suitable for radical RT were analysed. In 6 patients with stage I-II disease there was no improvement in PTV 90 , fV 20 , PTV/fV 20 ratio and fMLD using IMRT compared to 3-DCRT. In 11 patients with stage IIIA-B disease, the PTV was equally well covered with IMRT and 3-DCRT plans, with IMRT producing better PTV 90 /fV 20 ratio (mean ratio - 7.2 vs. 5.3, respectively, p = 0.001) and reduced f

  1. Hepatic Differentiation of Human Induced Pluripotent Stem Cells in a Perfused Three-Dimensional Multicompartment Bioreactor

    Directory of Open Access Journals (Sweden)

    Nora Freyer

    2016-08-01

    Full Text Available The hepatic differentiation of human induced pluripotent stem cells (hiPSC holds great potential for application in regenerative medicine, pharmacological drug screening, and toxicity testing. However, full maturation of hiPSC into functional hepatocytes has not yet been achieved. In this study, we investigated the potential of a dynamic three-dimensional (3D hollow fiber membrane bioreactor technology to improve the hepatic differentiation of hiPSC in comparison to static two-dimensional (2D cultures. A total of 100 × 106 hiPSC were seeded into each 3D bioreactor (n = 3. Differentiation into definitive endoderm (DE was induced by adding activin A, Wnt3a, and sodium butyrate to the culture medium. For further maturation, hepatocyte growth factor and oncostatin M were added. The same differentiation protocol was applied to hiPSC maintained in 2D cultures. Secretion of alpha-fetoprotein (AFP, a marker for DE, was significantly (p < 0.05 higher in 2D cultures, while secretion of albumin, a typical characteristic for mature hepatocytes, was higher after hepatic differentiation of hiPSC in 3D bioreactors. Functional analysis of multiple cytochrome P450 (CYP isoenzymes showed activity of CYP1A2, CYP2B6, and CYP3A4 in both groups, although at a lower level compared to primary human hepatocytes (PHH. CYP2B6 activities were significantly (p < 0.05 higher in 3D bioreactors compared with 2D cultures, which is in line with results from gene expression. Immunofluorescence staining showed that the majority of cells was positive for albumin, cytokeratin 18 (CK18, and hepatocyte nuclear factor 4-alpha (HNF4A at the end of the differentiation process. In addition, cytokeratin 19 (CK19 staining revealed the formation of bile duct-like structures in 3D bioreactors similar to native liver tissue. The results indicate a better maturation of hiPSC in the 3D bioreactor system compared to 2D cultures and emphasize the potential of dynamic 3D culture

  2. The research on the influences of hyperthermal perfusion chemotherapy combined with immunologic therapy on the immunologic function and levels of circulating tumor cells of the advanced colorectal cancer patients with liver metastasis.

    Science.gov (United States)

    Sun, J-J; Fan, G-L; Wang, X-G; Xu, K

    2017-07-01

    To investigated the influence of hyperthermal perfusion chemotherapy combined with immunologic therapy on the immunologic function and levels of circulating tumor cells of the advanced colorectal cancer patients with liver metastasis. We enrolled 98 advanced colorectal cancer patients with liver metastasis that were admitted to this hospital for treatment and were randomly divided into two groups, the observation group (n = 49) and the control group (n = 49). We administered systemic vein chemotherapy for patients in the control group, and hyperthermal perfusion chemotherapy for the patients in the observation group in order to compare the subgroup levels of T lymphocytes, NK cells and immunoglobulin (IgG, IgA, and IgM) in the immune system of patients in both groups. We also assayed the circulating tumor cells (CTC) in the peripheral blood of patients in both groups using the cell search method, and compared the efficacy using response evaluation criteria in solid tumors and the survival rates of patients in both groups using the Kaplan-Meier method. After two treatment courses, the levels of CD3+, CD4+ and CD4+/CD8+ of the patients in the observation group were significantly higher than those of the control group, but the levels of CD8+ of patients in the observation group was lower than that in the control group (pfunctions of patients for the indirect anti-tumor effect, a significant decrease in CTC of patients, and a higher long-term survival rate have been achieved in the treatment with hyperthermal perfusion chemotherapy combined with immunologic therapy for the advanced colorectal cancer patients with liver metastasis. Thus, it can serve as the preferable drug for the treatment of advanced colorectal cancer with liver metastasis.

  3. The effect of perfusion culture on proliferation and differentiation of human mesenchymal stem cells on biocorrodible bone replacement material

    International Nuclear Information System (INIS)

    Farack, J.; Wolf-Brandstetter, C.; Glorius, S.; Nies, B.; Standke, G.; Quadbeck, P.; Worch, H.; Scharnweber, D.

    2011-01-01

    Biocorrodible iron foams were coated with different calcium phosphate phases (CPP) to obtain a bioactive surface and controlled degradation. Further adhesion, proliferation and differentiation of SaOs-2 and human mesenchymal stem cells were investigated under both static and dynamic culture conditions. Hydroxyapatite (HA; [Ca 10 (PO 4 ) 6 OH 2 ]) coated foams released 500 μg/g iron per day for Dulbecco's modified eagle medium (DMEM) and 250 μg/g iron per day for McCoys, the unmodified reference 1000 μg/g iron per day for DMEM and 500 μg/g iron per day for McCoys, while no corrosion could be detected on brushite (CaHPO 4 ) coated foams. Using a perfusion culture system with conditions closer to the in vivo situation, cells proliferated and differentiated on iron foams coated with either brushite or HA while in static cell culture cells could proliferate only on Fe-brushite. We conclude that the degradation behaviour of biocorrodible iron foams can be varied by different calcium phosphate coatings, offering opportunities for design of novel bone implants. Further studies will focus on the influence of different modifications of iron foams on the expression of oxidative stress enzymes. Additional information about in vivo reactions and remodelling behaviour are expected from testing in implantation studies.

  4. Correlation between [{sup 18}F]FDG PET/CT and volume perfusion CT in primary tumours and mediastinal lymph nodes of non-small-cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sauter, Alexander W.; Spira, Daniel; Schulze, Maximilian; Pfannenberg, Christina; Claussen, Claus D.; Horger, Marius S. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Hetzel, Juergen [Eberhard Karls University, Department of Oncology, Hematology, Immunology, Rheumatology and Pulmonology, Tuebingen (Germany); Reimold, Matthias [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Klotz, Ernst [Siemens Healthcare, Computed Tomography, Forchheim (Germany)

    2013-05-15

    The aim of this study was to investigate correlations between glucose metabolism as determined by [{sup 18}F]FDG PET/CT and tumour perfusion as quantified by volume perfusion CT in primary tumours and mediastinal lymph nodes (MLN) of patients with non-small-cell lung cancer (NSCLC). Enrolled in the study were 17 patients with NSCLC. [{sup 18}F]FDG uptake was quantified in terms of SUV{sub max} and SUV{sub avg}. Blood flow (BF), blood volume (BV) and flow extraction product (K{sup trans}) were determined as perfusion parameters. The correlations between the perfusion parameters and [{sup 18}F]FDG uptake values were subsequently evaluated. For the primary tumours, no correlations were found between perfusion parameters and [{sup 18}F]FDG uptake. In MLN, there were negative correlations between BF and SUV{sub avg} (r = -0.383), BV and SUV{sub avg} (r = -0.406), and BV and SUV{sub max} (r = -0.377), but not between BF and SUV{sub max}, K{sup trans} and SUV{sub avg}, or K{sup trans} and SUV{sub max}. Additionally, in MLN with SUV{sub max} >2.5 there were negative correlations between BF and SUV{sub avg} (r = -0.510), BV and SUV{sub avg} (r = -0.390), BF and SUV{sub max} (r = -0.536), as well as BV and SUV{sub max} (r = -0.346). Perfusion and glucose metabolism seemed to be uncoupled in large primary tumours, but an inverse correlation was observed in MLN. This information may help improve therapy planning and response evaluation. (orig.)

  5. Quantitative Validation of the Presto Blue Metabolic Assay for Online Monitoring of Cell Proliferation in a 3D Perfusion Bioreactor System.

    Science.gov (United States)

    Sonnaert, Maarten; Papantoniou, Ioannis; Luyten, Frank P; Schrooten, Jan Ir

    2015-06-01

    As the fields of tissue engineering and regenerative medicine mature toward clinical applications, the need for online monitoring both for quantitative and qualitative use becomes essential. Resazurin-based metabolic assays are frequently applied for determining cytotoxicity and have shown great potential for monitoring 3D bioreactor-facilitated cell culture. However, no quantitative correlation between the metabolic conversion rate of resazurin and cell number has been defined yet. In this work, we determined conversion rates of Presto Blue, a resazurin-based metabolic assay, for human periosteal cells during 2D and 3D static and 3D perfusion cultures. Our results showed that for the evaluated culture systems there is a quantitative correlation between the Presto Blue conversion rate and the cell number during the expansion phase with no influence of the perfusion-related parameters, that is, flow rate and shear stress. The correlation between the cell number and Presto Blue conversion subsequently enabled the definition of operating windows for optimal signal readouts. In conclusion, our data showed that the conversion of the resazurin-based Presto Blue metabolic assay can be used as a quantitative readout for online monitoring of cell proliferation in a 3D perfusion bioreactor system, although a system-specific validation is required.

  6. Quantitative Validation of the Presto Blue™ Metabolic Assay for Online Monitoring of Cell Proliferation in a 3D Perfusion Bioreactor System

    Science.gov (United States)

    Sonnaert, Maarten; Papantoniou, Ioannis; Luyten, Frank P.

    2015-01-01

    As the fields of tissue engineering and regenerative medicine mature toward clinical applications, the need for online monitoring both for quantitative and qualitative use becomes essential. Resazurin-based metabolic assays are frequently applied for determining cytotoxicity and have shown great potential for monitoring 3D bioreactor-facilitated cell culture. However, no quantitative correlation between the metabolic conversion rate of resazurin and cell number has been defined yet. In this work, we determined conversion rates of Presto Blue™, a resazurin-based metabolic assay, for human periosteal cells during 2D and 3D static and 3D perfusion cultures. Our results showed that for the evaluated culture systems there is a quantitative correlation between the Presto Blue conversion rate and the cell number during the expansion phase with no influence of the perfusion-related parameters, that is, flow rate and shear stress. The correlation between the cell number and Presto Blue conversion subsequently enabled the definition of operating windows for optimal signal readouts. In conclusion, our data showed that the conversion of the resazurin-based Presto Blue metabolic assay can be used as a quantitative readout for online monitoring of cell proliferation in a 3D perfusion bioreactor system, although a system-specific validation is required. PMID:25336207

  7. Radiation exposure to surgical staff during hyperthermic isolated limb perfusion with 99m Technetium labeled red blood cells

    DEFF Research Database (Denmark)

    Kristoffersen, Ulrik Sloth; Straalman, Kristina; Schmidt, Grethe

    2009-01-01

    PURPOSE: Hyperthermic isolated limb perfusion (HILP) is an effective method in the treatment of recurrent melanomas and soft tissue sarcomas. To avoid systemic toxicity, leakage from the limb perfusate into the systemic circulation is real-time monitored by administration of a radioactive agent...

  8. Monitoring Cell Death in Regorafenib-Treated Experimental Colon Carcinomas Using Annexin-Based Optical Fluorescence Imaging Validated by Perfusion MRI.

    Directory of Open Access Journals (Sweden)

    Philipp M Kazmierczak

    Full Text Available To investigate annexin-based optical fluorescence imaging (OI for monitoring regorafenib-induced early cell death in experimental colon carcinomas in rats, validated by perfusion MRI and multiparametric immunohistochemistry.Subcutaneous human colon carcinomas (HT-29 in athymic rats (n = 16 were imaged before and after a one-week therapy with regorafenib (n = 8 or placebo (n = 8 using annexin-based OI and perfusion MRI at 3 Tesla. Optical signal-to-noise ratio (SNR and MRI tumor perfusion parameters (plasma flow PF, mL/100mL/min; plasma volume PV, % were assessed. On day 7, tumors underwent immunohistochemical analysis for tumor cell apoptosis (TUNEL, proliferation (Ki-67, and microvascular density (CD31.Apoptosis-targeted OI demonstrated a tumor-specific probe accumulation with a significant increase of tumor SNR under therapy (mean Δ +7.78±2.95, control: -0.80±2.48, p = 0.021. MRI detected a significant reduction of tumor perfusion in the therapy group (mean ΔPF -8.17±2.32 mL/100 mL/min, control -0.11±3.36 mL/100 mL/min, p = 0.036. Immunohistochemistry showed significantly more apoptosis (TUNEL; 11392±1486 vs. 2921±334, p = 0.001, significantly less proliferation (Ki-67; 1754±184 vs. 2883±323, p = 0.012, and significantly lower microvascular density (CD31; 107±10 vs. 182±22, p = 0.006 in the therapy group.Annexin-based OI allowed for the non-invasive monitoring of regorafenib-induced early cell death in experimental colon carcinomas, validated by perfusion MRI and multiparametric immunohistochemistry.

  9. The Effect of Primary Cancer Cell Culture Models on the Results of Drug Chemosensitivity Assays: The Application of Perfusion Microbioreactor System as Cell Culture Vessel

    Science.gov (United States)

    Chen, Yi-Dao; Huang, Shiang-Fu; Wang, Hung-Ming

    2015-01-01

    To precisely and faithfully perform cell-based drug chemosensitivity assays, a well-defined and biologically relevant culture condition is required. For the former, a perfusion microbioreactor system capable of providing a stable culture condition was adopted. For the latter, however, little is known about the impact of culture models on the physiology and chemosensitivity assay results of primary oral cavity cancer cells. To address the issues, experiments were performed. Results showed that minor environmental pH change could significantly affect the metabolic activity of cells, demonstrating the importance of stable culture condition for such assays. Moreover, the culture models could also significantly influence the metabolic activity and proliferation of cells. Furthermore, the choice of culture models might lead to different outcomes of chemosensitivity assays. Compared with the similar test based on tumor-level assays, the spheroid model could overestimate the drug resistance of cells to cisplatin, whereas the 2D and 3D culture models might overestimate the chemosensitivity of cells to such anticancer drug. In this study, the 3D culture models with same cell density as that in tumor samples showed comparable chemosensitivity assay results as the tumor-level assays. Overall, this study has provided some fundamental information for establishing a precise and faithful drug chemosensitivity assay. PMID:25654105

  10. Perfusion bioreactor-based cryopreservation of 3D human mesenchymal stromal cell tissue grafts

    Czech Academy of Sciences Publication Activity Database

    Petrenko, Yuriy; Petrenko, A.; Martin, I.; Wendt, D.

    2017-01-01

    Roč. 76, jun. (2017), s. 150-153 ISSN 0011-2240 Institutional support: RVO:68378041 Keywords : cryopreservation * tissue engineering * mesenchymal stromal cells Subject RIV: FP - Other Medical Disciplines OBOR OECD: Cell biology Impact factor: 1.996, year: 2016

  11. Fish kidney cells show higher tolerance to hyperosmolality than amphibian

    Directory of Open Access Journals (Sweden)

    Lang Gui

    2018-05-01

    Full Text Available In contrast to fish, amphibians inhabit both aquatic and terrestrial environments. To better understand osmoregulation in fish and amphibian, we have investigated the morphological changes in kidney cells to osmotic stress. To address this, kidney cell line isolated from the freshwater grass carp (CIK and Chinese giant salamander (GSK were challenged to different mediums with distinct osmotic pressures (100, 300 and 700 mOsm. Morphological alterations of the fish and amphibian cells were compared by optical and electron microscopy. Following hyposmotic treatment (100 mOsm, both CIK and GSK cells became unhealthy and show condensed chromatin, swollen mitochondria and cytoplasmic vacuole. Meanwhile, after hyperosmotic treatment (700 mOsm, shrunken CIK cells with multipolar shape, pale or lightly stained cytoplasm, condensed chromatin, vacuoles and swollen mitochondria were detected. GSK cells were seriously damaged and most were completely lysed. The results suggest that fish kidney cells show a higher degree of tolerance to hyperosmoticity by comparing to amphibians and provide novel insights on the osmoregulatory capacity and adaptability of kidney cells between the two animal groups.

  12. Isolated limb perfusion electrochemotherapy for the treatment of an advanced squamous cell carcinoma of the hoof in a mare

    Directory of Open Access Journals (Sweden)

    Enrico Pierluigi Spugnini

    2017-06-01

    Full Text Available A twenty-year-old female saddle horse was referred for evaluation of a seven month, non-healing erosive lesion of the right hind hoof with proliferation and bleeding of the underlying soft tissues. This lesion had been twice surgically treated as a canker but rapidly recurred. Histological examination of the second excision revealed a well-differentiated squamous cell carcinoma. At presentation, the horse was mildly depressed, lame and partially non-weight-bearing on the right hind leg, which exhibited a 10 x 10 cm erosive and proliferative lesion remodeling the hoof. After completing staging procedures, the lesion was approached with surgery and intraoperative electrochemotherapy (ECT administration of bleomycin in isolated limb perfusion. A second session of surgery and ECT was performed one month later, followed by three additional monthly sessions of ECT. During periodic recheck, the mare showed continuous improvement. One year after presentation, the mare was in complete remission and her gait markedly improved. ECT was well-tolerated and resulted in improved local control of a tumor in a challenging anatomical district.

  13. Cloning higher plants from aseptically cultured tissues and cells

    Science.gov (United States)

    Krikorian, A. D.

    1982-01-01

    A review of aseptic culture methods for higher plants is presented, which focuses on the existing problems that limit or prevent the full realization of cloning plants from free cells. It is shown that substantial progress in clonal multiplication has been made with explanted stem tips or lateral buds which can be stimulated to produce numerous precocious axillary branches. These branches can then be separated or subdivided and induced to root in order to yield populations of genetically and phenotypically uniorm plantlets. Similarly, undifferentiated calluses can sometimes be induced to form shoots and/or roots adventitiously. Although the cell culture techniques required to produce somatic embryos are presently rudimentary, steady advances are being made in learning how to stimulate formation of somatic or adventive embryos from totipotent cells grown in suspension cultures. It is concluded that many problems exist in the producing and growing of totipotent or morphogenetically competent cell suspensions, but the potential benefits are great.

  14. Microfluidic Impedimetric Cell Regeneration Assay to Monitor the Enhanced Cytotoxic Effect of Nanomaterial Perfusion

    Directory of Open Access Journals (Sweden)

    Mario Rothbauer

    2015-11-01

    Full Text Available In the last decade, the application of nanomaterials (NMs in technical products and biomedicine has become a rapidly increasing market trend. As the safety and efficacy of NMs are of utmost importance, new methods are needed to study the dynamic interactions of NMs at the nano-biointerface. However, evaluation of NMs based on standard and static cell culture end-point detection methods does not provide information on the dynamics of living biological systems, which is crucial for the understanding of physiological responses. To bridge this technological gap, we here present a microfluidic cell culture system containing embedded impedance microsensors to continuously and non-invasively monitor the effects of NMs on adherent cells under varying flow conditions. As a model, the impact of silica NMs on the vitality and regenerative capacity of human lung cells after acute and chronic exposure scenarios was studied over an 18-h period following a four-hour NM treatment. Results of the study demonstrated that the developed system is applicable to reliably analyze the consequences of dynamic NM exposure to physiological cell barriers in both nanotoxicology and nanomedicine.

  15. Microfluidic Impedimetric Cell Regeneration Assay to Monitor the Enhanced Cytotoxic Effect of Nanomaterial Perfusion.

    Science.gov (United States)

    Rothbauer, Mario; Praisler, Irene; Docter, Dominic; Stauber, Roland H; Ertl, Peter

    2015-11-27

    In the last decade, the application of nanomaterials (NMs) in technical products and biomedicine has become a rapidly increasing market trend. As the safety and efficacy of NMs are of utmost importance, new methods are needed to study the dynamic interactions of NMs at the nano-biointerface. However, evaluation of NMs based on standard and static cell culture end-point detection methods does not provide information on the dynamics of living biological systems, which is crucial for the understanding of physiological responses. To bridge this technological gap, we here present a microfluidic cell culture system containing embedded impedance microsensors to continuously and non-invasively monitor the effects of NMs on adherent cells under varying flow conditions. As a model, the impact of silica NMs on the vitality and regenerative capacity of human lung cells after acute and chronic exposure scenarios was studied over an 18-h period following a four-hour NM treatment. Results of the study demonstrated that the developed system is applicable to reliably analyze the consequences of dynamic NM exposure to physiological cell barriers in both nanotoxicology and nanomedicine.

  16. Residual DNA double strand breaks in perfused but not in unperfused areas determine different radiosensitivity of tumours

    International Nuclear Information System (INIS)

    Menegakis, Apostolos; Eicheler, Wolfgang; Yaromina, Ala; Thames, Howard D.; Krause, Mechthild; Baumann, Michael

    2011-01-01

    Purpose: Micromilieu-dependent quantification of γH2AX after irradiation in vivo and correlation with local tumour control. Materials and methods: Local tumour control was evaluated after irradiation of FaDu and SKX xenografts with ambient single doses. γH2AX foci were quantified in perfused and unperfused regions after different irradiation doses and at different time points. Results: The TCD 50 of FaDu was 2-times higher compared to SKX (28.0 Gy [95% C.I. 24.6; 31.3 Gy] for FaDu; 14.9 Gy [10.9; 18.9] for SKX, p < 0.001). The induction of foci did not differ between the tumour models. Residual foci were twice higher in perfused SKX regions compared to FaDu, no difference was observed in the non-perfused region between both tumour models. The number of residual foci increased with a 2-times higher slope in perfused SKX-regions compared to FaDu, while no difference was detected in unperfused regions. Already within the perfused regions, this slope decreased with distance from perfused vessels. Conclusion: The dose-response of residual γH2AX foci is highly dependent on tumour cell oxygenation in well perfused areas. This dependence decreases further away from tumour vessels. Only γH2AX evaluation in perfused tumour areas can distinguish between the different radiocurability of the two tumour models.

  17. Detachably assembled microfluidic device for perfusion culture and post-culture analysis of a spheroid array.

    Science.gov (United States)

    Sakai, Yusuke; Hattori, Koji; Yanagawa, Fumiki; Sugiura, Shinji; Kanamori, Toshiyuki; Nakazawa, Kohji

    2014-07-01

    Microfluidic devices permit perfusion culture of three-dimensional (3D) tissue, mimicking the flow of blood in vascularized 3D tissue in our body. Here, we report a microfluidic device composed of a two-part microfluidic chamber chip and multi-microwell array chip able to be disassembled at the culture endpoint. Within the microfluidic chamber, an array of 3D tissue aggregates (spheroids) can be formed and cultured under perfusion. Subsequently, detailed post-culture analysis of the spheroids collected from the disassembled device can be performed. This device facilitates uniform spheroid formation, growth analysis in a high-throughput format, controlled proliferation via perfusion flow rate, and post-culture analysis of spheroids. We used the device to culture spheroids of human hepatocellular carcinoma (HepG2) cells under two controlled perfusion flow rates. HepG2 spheroids exhibited greater cell growth at higher perfusion flow rates than at lower perfusion flow rates, and exhibited different metabolic activity and mRNA and protein expression under the different flow rate conditions. These results show the potential of perfusion culture to precisely control the culture environment in microfluidic devices. The construction of spheroid array chambers allows multiple culture conditions to be tested simultaneously, with potential applications in toxicity and drug screening. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan); Fujisawa, Yasuko [Toshiba Medical Systems Corporation, Otawara (Japan); Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro [Division of Radiology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Sugihara, Naoki [Toshiba Medical Systems Corporation, Otawara (Japan); Yoshikawa, Takeshi [Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Advanced Biomedical Imaging Research Center, Kobe University Graduate School of Medicine, Kobe (Japan)

    2017-01-15

    Purpose: To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Materials and methods: Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR + PR) and 2) stable or progressive disease (SD + PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV{sub max}, and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. Results: The step-wise regression test showed that therapeutic effect (r{sup 2} = 0.63, p = 0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV{sub max}. Mean overall survival showed a significant difference for total perfusion (p = 0.003) and systemic arterial perfusion (p = 0.04). Conclusion: Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy.

  19. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT

    International Nuclear Information System (INIS)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

    2017-01-01

    Purpose: To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Materials and methods: Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR + PR) and 2) stable or progressive disease (SD + PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV max , and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. Results: The step-wise regression test showed that therapeutic effect (r 2 = 0.63, p = 0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV max . Mean overall survival showed a significant difference for total perfusion (p = 0.003) and systemic arterial perfusion (p = 0.04). Conclusion: Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy.

  20. Dynamic contrast-enhanced perfusion area-detector CT assessed with various mathematical models: Its capability for therapeutic outcome prediction for non-small cell lung cancer patients with chemoradiotherapy as compared with that of FDG-PET/CT.

    Science.gov (United States)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Koyama, Hisanobu; Kishida, Yuji; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

    2017-01-01

    To directly compare the capability of dynamic first-pass contrast-enhanced (CE-) perfusion area-detector CT (ADCT) and PET/CT for early prediction of treatment response, disease progression and overall survival of non-small cell carcinoma (NSCLC) patients treated with chemoradiotherapy. Fifty-three consecutive Stage IIIB NSCLC patients who had undergone PET/CT, dynamic first-pass CE-perfusion ADCT, chemoradiotherapy, and follow-up examination were enrolled in this study. They were divided into two groups: 1) complete or partial response (CR+PR) and 2) stable or progressive disease (SD+PD). Pulmonary arterial and systemic arterial perfusions and total perfusion were assessed at targeted lesions with the dual-input maximum slope method, permeability surface and distribution volume with the Patlak plot method, tumor perfusion with the single-input maximum slope method, and SUV max , and results were averaged to determine final values for each patient. Next, step-wise regression analysis was used to determine which indices were the most useful for predicting therapeutic effect. Finally, overall survival of responders and non-responders assessed by using the indices that had a significant effect on prediction of therapeutic outcome was statistically compared. The step-wise regression test showed that therapeutic effect (r 2 =0.63, p=0.01) was significantly affected by the following three factors in order of magnitude of impact: systemic arterial perfusion, total perfusion, and SUV max . Mean overall survival showed a significant difference for total perfusion (p=0.003) and systemic arterial perfusion (p=0.04). Dynamic first-pass CE-perfusion ADCT as well as PET/CT are useful for treatment response prediction in NSCLC patients treated with chemoradiotherapy. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. Effects of Steroid Hormones on Sex Differences in Cerebral Perfusion.

    Directory of Open Access Journals (Sweden)

    Carmen Ghisleni

    Full Text Available Sex differences in the brain appear to play an important role in the prevalence and progression of various neuropsychiatric disorders, but to date little is known about the cerebral mechanisms underlying these differences. One widely reported finding is that women demonstrate higher cerebral perfusion than men, but the underlying cause of this difference in perfusion is not known. This study investigated the putative role of steroid hormones such as oestradiol, testosterone, and dehydroepiandrosterone sulphate (DHEAS as underlying factors influencing cerebral perfusion. We acquired arterial spin labelling perfusion images of 36 healthy adult subjects (16 men, 20 women. Analyses on average whole brain perfusion levels included a multiple regression analysis to test for the relative impact of each hormone on the global perfusion. Additionally, voxel-based analyses were performed to investigate the sex difference in regional perfusion as well as the correlations between local perfusion and serum oestradiol, testosterone, and DHEAS concentrations. Our results replicated the known sex difference in perfusion, with women showing significantly higher global and regional perfusion. For the global perfusion, DHEAS was the only significant predictor amongst the steroid hormones, showing a strong negative correlation with cerebral perfusion. The voxel-based analyses revealed modest sex-dependent correlations between local perfusion and testosterone, in addition to a strong modulatory effect of DHEAS in cortical, subcortical, and cerebellar regions. We conclude that DHEAS in particular may play an important role as an underlying factor driving the difference in cerebral perfusion between men and women.

  2. Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation.

    Science.gov (United States)

    Knaak, Jan M; Spetzler, Vinzent N; Goldaracena, Nicolas; Boehnert, Markus U; Bazerbachi, Fateh; Louis, Kristine S; Adeyi, Oyedele A; Minkovich, Leonid; Yip, Paul M; Keshavjee, Shaf; Levy, Gary A; Grant, David R; Selzner, Nazia; Selzner, Markus

    2014-11-01

    An ischemic-type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7-hour CS and 3-hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long-term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP- and CS-treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP-treated livers (7.3 × 10(-4) ± 2.6 × 10(-4) cells/μm(2)) but not in CS-treated livers (3.7 × 10(-4) ± 1.3 × 10(-4) cells/μm(2) , P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 μmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation. © 2014 American Association for the Study of Liver Diseases.

  3. Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lau Chu-Pak

    2010-01-01

    Full Text Available Abstract Background Recent studies suggested that bone marrow (BM cell implantation in patients with severe chronic coronary artery disease (CAD resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR. Methods and Results We compared the interval changes of left ventricular ejection fraction (LVEF, myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12 injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, P = 0.04 and increase in global LVEF (+9.0%, P = 0.02, the percentage of regional wall thickening (+13.1%, P= 0.04 and MPR (+0.25%, P = 0.03 over the target area at 6-months compared with baseline. Conclusions Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.

  4. Preserving Functional Lung Using Perfusion Imaging and Intensity-Modulated Radiation Therapy for Advanced-Stage Non-Small Cell Lung Cancer

    International Nuclear Information System (INIS)

    Shioyama, Yoshiyuki; Jang, Si Young; Liu, H. Helen; Guerrero, Thomas; Wang, Xuanmin; Gayed, Isis W.; Erwin, William D.; Liao, Zhongxing; Chang, Joe Y.; Jeter, Melenda; Yaremko, Brian P.; Borghero, Yerko O.; Cox, James D.; Komaki, Ritsuko; Mohan, Radhe

    2007-01-01

    Purpose: To assess quantitatively the impact of incorporating functional lung imaging into intensity-modulated radiation therapy planning for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials: Sixteen patients with advanced-stage NSCLC who underwent radiotherapy were included in this study. Before radiotherapy, each patient underwent lung perfusion imaging with single-photon-emission computed tomography and X-ray computed tomography (SPECT-CT). The SPECT-CT was registered with simulation CT and was used to segment the 50- and 90-percentile hyperperfusion lung (F50 lung and F90 lung). Two IMRT plans were designed and compared in each patient: an anatomic plan using simulation CT alone and a functional plan using SPECT-CT in addition to the simulation CT. Dosimetric parameters of the two types of plans were compared in terms of tumor coverage and avoidance of normal tissues. Results: In incorporating perfusion information in IMRT planning, the median reductions in the mean doses to the F50 and F90 lung in the functional plan were 2.2 and 4.2 Gy, respectively, compared with those in the anatomic plans. The median reductions in the percentage of volume irradiated with >5 Gy, >10 Gy, and >20 Gy in the functional plans were 7.1%, 6.0%, and 5.1%, respectively, for F50 lung, and 11.7%, 12.0%, and 6.8%, respectively, for F90 lung. A greater degree of sparing of the functional lung was achieved for patients with large perfusion defects compared with those with relatively uniform perfusion distribution. Conclusion: Function-guided IMRT planning appears to be effective in preserving functional lung in locally advanced-stage NSCLC patients

  5. CIGS cells with metallized front contact: Longer cells and higher efficiency

    NARCIS (Netherlands)

    Deelen, J. van; Frijters, C.

    2017-01-01

    We have investigated the benefit of a patterned metallization on top of a transparent conductive oxide in CIGS thin-film solar panels. It was found that cells with a grid have a higher efficiency compared to cells with only a TCO. This was observed for all cell lengths used. Furthermore, metallic

  6. Human Umbilical Cord-Derived Mesenchymal Stromal Cells Improve Left Ventricular Function, Perfusion, and Remodeling in a Porcine Model of Chronic Myocardial Ischemia

    Science.gov (United States)

    Liu, Chuan-Bin; Huang, He; Sun, Ping; Ma, Shi-Ze; Liu, An-Heng; Xue, Jian; Fu, Jin-Hui; Liang, Yu-Qian; Liu, Bing; Wu, Dong-Ying

    2016-01-01

    Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton’s jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia. Significance Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called “no-option” patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation. PMID

  7. Analysis of glutathione in supernatants and lysates of a human proximal tubular cell line from perfusion culture upon intoxication with cadmium chloride by HPLC and LC-ESI-MS

    NARCIS (Netherlands)

    Hahn, Hans; Huck, Christian W; Rainer, Matthias; Najam-ul-Haq, Muhammad; Bakry, Rania; Abberger, Thomas; Jennings, Paul; Pfaller, Walter; Bonn, Günther K

    A simple and highly effective reversed-phase (RP) high-performance liquid chromatography (HPLC) method is described for analysing glutathione (GSH) and glutathione disulfide (GSSG) in out-flowing supernatants and lysates of perfusion cell cultures of human kidney cells (HK-2 cells) continuously

  8. Effective avoidance of a functional spect-perfused lung using intensity modulated radiotherapy (IMRT) for non-small cell lung cancer (NSCLC): An update of a planning study

    International Nuclear Information System (INIS)

    Lavrenkov, Konstantin; Singh, Shalini; Christian, Judith A.; Partridge, Mike; Nioutsikou, Elena; Cook, Gary; Bedford, James L.; Brada, Michael

    2009-01-01

    IMRT and 3-dimensional conformal radiotherapy (3-DCRT) plans of 25 patients with non-small cell lung (NSCLC) were compared in terms of planning target volume (PTV) coverage and sparing of functional lung (FL) defined by a SPECT perfusion scan. IMRT resulted in significant reduction of functional V 20 and mean lung dose in stage III patients with inhomogeneous hypoperfusion. If the dose to FL is shown to be the determinant of lung toxicity, IMRT would allow for effective dose escalation by specific avoidance of functional lung.

  9. Perfusion seed cultures improve biopharmaceutical fed-batch production capacity and product quality.

    Science.gov (United States)

    Yang, William C; Lu, Jiuyi; Kwiatkowski, Chris; Yuan, Hang; Kshirsagar, Rashmi; Ryll, Thomas; Huang, Yao-Ming

    2014-01-01

    Volumetric productivity and product quality are two key performance indicators for any biopharmaceutical cell culture process. In this work, we showed proof-of-concept for improving both through the use of alternating tangential flow perfusion seed cultures coupled with high-seed fed-batch production cultures. First, we optimized the perfusion N-1 stage, the seed train bioreactor stage immediately prior to the production bioreactor stage, to minimize the consumption of perfusion media for one CHO cell line and then successfully applied the optimized perfusion process to a different CHO cell line. Exponential growth was observed throughout the N-1 duration, reaching >40 × 10(6) vc/mL at the end of the perfusion N-1 stage. The cultures were subsequently split into high-seed (10 × 10(6) vc/mL) fed-batch production cultures. This strategy significantly shortened the culture duration. The high-seed fed-batch production processes for cell lines A and B reached 5 g/L titer in 12 days, while their respective low-seed processes reached the same titer in 17 days. The shortened production culture duration potentially generates a 30% increase in manufacturing capacity while yielding comparable product quality. When perfusion N-1 and high-seed fed-batch production were applied to cell line C, higher levels of the active protein were obtained, compared to the low-seed process. This, combined with correspondingly lower levels of the inactive species, can enhance the overall process yield for the active species. Using three different CHO cell lines, we showed that perfusion seed cultures can optimize capacity utilization and improve process efficiency by increasing volumetric productivity while maintaining or improving product quality. © 2014 American Institute of Chemical Engineers.

  10. Lung perfusion scintigraphy by SPECT

    International Nuclear Information System (INIS)

    Hirayama, Takanobu

    1990-01-01

    The initial study reports the characteristic performance using lung segmental phantom filled in Tc-99m pertechnetate. To evaluate the segmental defect in lung perfusion scintigraphy, we applied Bull's-eye analysis in addition to planar image set. Bull's-eye analysis especially facilitated the interpretation in both middle and lower lobes. Subsequently, to evolute the clinical application of Bull's-eye analysis, pulmonary scintigraphy was performed on 10 normal subjects and 60 patients with several pulmonary diseases. Of interest, Bull's-eye analysis, however, encouraged the interpretation in both lower lobes. To calculate the extention and severity of perfusion defect, the present study describes Bull's-eye analysis. Quantitative scoring showed higher in patients with lung cancer than those with pulmonary tuberculosis. The present study focus that Bull's-eye analysis can be useful for evaluating perfusion in patients with a couple of pulmonary diseases. (author)

  11. 1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart

    OpenAIRE

    Jelicks, L.A.; Wittenberg, B.A.

    1995-01-01

    The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin res...

  12. Assembly of cell-laden hydrogel fiber into non-liquefied and liquefied 3D spiral constructs by perfusion-based layer-by-layer technique

    International Nuclear Information System (INIS)

    Sher, Praveen; Oliveira, Sara M; Borges, João; Mano, João F

    2015-01-01

    In this work, three-dimensional (3D) self-sustaining, spiral-shaped constructs were produced through a combination of ionotropic gelation, to form cell-encapsulated alginate fibers, and a perfusion-based layer-by-layer (LbL) technique. Single fibers were assembled over cylindrical molds by reeling to form spiral shapes, both having different geometries and sizes. An uninterrupted nanometric multilayer coating produced by a perfusion-based LbL technique, using alginate and chitosan, generated stable 3D spiral-shaped macrostructures by gripping and affixing the threads together without using any crosslinking/binding agent. The chelation process altered the internal microenvironment of the 3D construct from the solid to the liquefied state while preserving the external geometry. L929 cell viability by MTS and dsDNA quantification favor liquefied 3D constructs more than non-liquefied ones. The proposed technique setup helps us to generate complex polyelectrolyte-based 3D constructs for tissue engineering applications and organ printing. (note)

  13. Amniotic Fluid Cells Show Higher Pluripotency-Related Gene Expression Than Allantoic Fluid Cells.

    Science.gov (United States)

    Kehl, Debora; Generali, Melanie; Görtz, Sabrina; Geering, Diego; Slamecka, Jaroslav; Hoerstrup, Simon P; Bleul, Ulrich; Weber, Benedikt

    2017-10-01

    Amniotic fluid represents an abundant source of multipotent stem cells, referred as broadly multipotent given their differentiation potential and expression of pluripotency-related genes. However, the origin of this broadly multipotent cellular fraction is not fully understood. Several sources have been proposed so far, including embryonic and extraembryonic tissues. In this regard, the ovine developmental model uniquely allows for direct comparison of fetal fluid-derived cells from two separate fetal fluid cavities, the allantois and the amnion, over the entire duration of gestation. As allantoic fluid mainly collects fetal urine, cells originating from the efferent urinary tract can directly be compared with cells deriving from the extraembryonic amniotic tissues and the fetus. This study shows isolation of cells from the amniotic [ovine amniotic fluid cells (oAFCs)] and allantoic fluid [ovine allantoic fluid cells (oALCs)] in a strictly paired fashion with oAFCs and oALCs derived from the same fetus. Both cell types showed cellular phenotypes comparable to standard mesenchymal stem cells (MSCs), with trilineage differentiation potential, and expression of common ovine MSC markers. However, the expression of MSC markers per single cell was higher in oAFCs as measured by flow cytometry. oAFCs exhibited higher proliferative capacities and showed significantly higher expression of pluripotency-related genes OCT4, STAT3, NANOG, and REX1 by quantitative real-time polymerase chain reaction compared with paired oALCs. No significant decrease of pluripotency-related gene expression was noted over gestation, implying that cells with high differentiation potential may be isolated at the end of pregnancy. In conclusion, this study suggests that cells with highest stem cell characteristics may originate from the fetus itself or the amniotic fetal adnexa rather than from the efferent urinary tract or the allantoic fetal adnexa.

  14. Increased sinusoidal volume and solute extraction during retrograde liver perfusion

    International Nuclear Information System (INIS)

    Bass, N.M.; Manning, J.A.; Weisiger, R.A.

    1989-01-01

    Retrograde isolated liver perfusion has been used to probe acinar functional heterogeneity, but the hemodynamic effects of backward flow have not been characterized. In this study, extraction of a long-chain fatty acid derivative, 12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazol-amino stearate (12-NBDS), was greater during retrograde than during anterograde perfusion of isolated rat liver. To determine whether hemodynamic differences between anterograde and retrograde perfused livers could account for this finding, the hepatic extracellular space was measured for both directions of flow by means of [ 14 C]sucrose washout during perfusion as well as by direct measurement of [ 14 C]sucrose entrapped during perfusion. A three- to fourfold enlargement of the total hepatic extracellular space was found during retrograde perfusion by both approaches. Examination of perfusion-fixed livers by light microscopy and morphometry revealed that marked distension of the sinusoids occurred during retrograde perfusion and that this accounts for the observed increase in the [ 14 C]sucrose space. These findings support the hypothesis that maximum resistance to perfusate flow in the isolated perfused rat liver is located at the presinusoidal level. In addition, increased transit time of perfusate through the liver and greater sinusoidal surface area resulting from sinusoidal distension may account for the higher extraction of 12-NBDS and possibly other compounds by retrograde perfused liver

  15. Dynamic Contrast-Enhanced Perfusion Area-Detector CT: Preliminary Comparison of Diagnostic Performance for N Stage Assessment With FDG PET/CT in Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Ohno, Yoshiharu; Fujisawa, Yasuko; Sugihara, Naoki; Kishida, Yuji; Seki, Shinichiro; Koyama, Hisanobu; Yoshikawa, Takeshi

    2017-11-01

    The objective of our study was to directly compare the capability of dynamic first-pass contrast-enhanced (CE) perfusion area-detector CT (ADCT) and FDG PET/CT for differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with non-small cell lung carcinoma (NSCLC). Seventy-seven consecutive patients, 45 men (mean age ± SD, 70.4 ± 5.9 years) and 32 women (71.2 ± 7.7 years), underwent dynamic first-pass CE-perfusion ADCT at two or three different positions for covering the entire thorax, FDG PET/CT, surgical treatment, and pathologic examination. From all ADCT data for each of the subjects, a whole-chest perfusion map was computationally generated using the dual- and single-input maximum slope and Patlak plot methods. For quantitative N stage assessment, perfusion parameters and the maximum standardized uptake value (SUV max ) for each lymph node were determined by measuring the relevant ROI. ROC curve analyses were performed for comparing the diagnostic capability of each of the methods on a per-node basis. N stages evaluated by each of the indexes were then statistically compared with the final pathologic diagnosis by means of chi-square and kappa statistics. The area under the ROC curve (A z ) values of systemic arterial perfusion (A z = 0.89), permeability surface (A z = 0.78), and SUV max (A z = 0.85) were significantly larger than the A z values of total perfusion (A z = 0.70, p Dynamic first-pass CE-perfusion ADCT is as useful as FDG PET/CT for the differentiation of metastatic from nonmetastatic lymph nodes and assessment of N stage in patients with NSCLC.

  16. Backup pathways of NHEJ in cells of higher eukaryotes: Cell cycle dependence

    International Nuclear Information System (INIS)

    Iliakis, George

    2009-01-01

    DNA double-strand breaks (DSBs) induced by ionizing radiation (IR) in cells of higher eukaryotes are predominantly repaired by a pathway of non-homologous end joining (NHEJ) utilizing Ku, DNA-PKcs, DNA ligase IV, XRCC4 and XLF/Cernunnos (D-NHEJ) as central components. Work carried out in our laboratory and elsewhere shows that when this pathway is chemically or genetically compromised, cells do not shunt DSBs to homologous recombination repair (HRR) but instead use another form of NHEJ operating as a backup (B-NHEJ). Here I review our efforts to characterize this repair pathway and discuss its dependence on the cell cycle as well as on the growth conditions. I present evidence that B-NHEJ utilizes ligase III, PARP-1 and histone H1. When B-NHEJ is examined throughout the cell cycle, significantly higher activity is observed in G2 phase that cannot be attributed to HRR. Furthermore, the activity of B-NHEJ is compromised when cells enter the plateau phase of growth. Together, these observations uncover a repair pathway with unexpected biochemical constitution and interesting cell cycle and growth factor regulation. They generate a framework for investigating the mechanistic basis of HRR contribution to DSB repair.

  17. Detection of Local Tumor Recurrence After Definitive Treatment of Head and Neck Squamous Cell Carcinoma: Histogram Analysis of Dynamic Contrast-Enhanced T1-Weighted Perfusion MRI.

    Science.gov (United States)

    Choi, Sang Hyun; Lee, Jeong Hyun; Choi, Young Jun; Park, Ji Eun; Sung, Yu Sub; Kim, Namkug; Baek, Jung Hwan

    2017-01-01

    This study aimed to explore the added value of histogram analysis of the ratio of initial to final 90-second time-signal intensity AUC (AUCR) for differentiating local tumor recurrence from contrast-enhancing scar on follow-up dynamic contrast-enhanced T1-weighted perfusion MRI of patients treated for head and neck squamous cell carcinoma (HNSCC). AUCR histogram parameters were assessed among tumor recurrence (n = 19) and contrast-enhancing scar (n = 27) at primary sites and compared using the t test. ROC analysis was used to determine the best differentiating parameters. The added value of AUCR histogram parameters was assessed when they were added to inconclusive conventional MRI results. Histogram analysis showed statistically significant differences in the 50th, 75th, and 90th percentiles of the AUCR values between the two groups (p Histogram analysis of AUCR can improve the diagnostic yield for local tumor recurrence during surveillance after treatment for HNSCC.

  18. Higher cell stiffness indicating lower metastatic potential in B16 melanoma cell variants and in (-)-epigallocatechin gallate-treated cells.

    Science.gov (United States)

    Watanabe, Tatsuro; Kuramochi, Hiromi; Takahashi, Atsushi; Imai, Kazue; Katsuta, Naoko; Nakayama, Tomonobu; Fujiki, Hirota; Suganuma, Masami

    2012-05-01

    To understand how nanomechanical stiffness affects metastatic potential, we studied the relationship between cell migration, a characteristic of metastasis, and cell stiffness using atomic force microscopy (AFM), which can measure stiffness (elasticity) of individual living cells. Migration and cell stiffness of three metastatic B16 melanoma variants (B16-F10, B16-BL6, and B16-F1 cells), and also effects of (-)-epigallocatechin gallate (EGCG), were studied using Transwell assay and AFM. Migration of B16-F10 and B16-BL6 cells was 3 and 2 times higher than that of B16-F1 cells in Transwell assay, and cell stiffness determined by AFM was also different among the three variants, although they have similar morphologies and the same growth rates: Means of Young's modulus were 350.8 ± 4.8 Pa for B16-F10 cells, 661.9 ± 16.5 Pa for B16-BL6 cells, and 727.2 ± 13.0 Pa for B16-F1 cells. AFM measurements revealed that highly motile B16-F10 cells have low cell stiffness, and low motile and metastatic B16-F1 cells have high cell stiffness: Nanomechanical stiffness is inversely correlated with migration potential. Treatment of highly motile B16-F10 cells with EGCG increased cell stiffness 2-fold and inhibited migration of the cells. Our study with AFM clearly demonstrates that cell stiffness is a reliable quantitative indicator of migration potential, and very likely metastatic potential, even in morphologically similar cells. And increased cell stiffness may be a key nanomechanical feature in inhibition of metastasis.

  19. Cardiac tissue engineering using perfusion bioreactor systems

    Science.gov (United States)

    Radisic, Milica; Marsano, Anna; Maidhof, Robert; Wang, Yadong; Vunjak-Novakovic, Gordana

    2009-01-01

    This protocol describes tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cell populations on porous scaffolds (in some cases with an array of channels) and bioreactors with perfusion of culture medium (in some cases supplemented with an oxygen carrier). The overall approach is ‘biomimetic’ in nature as it tends to provide in vivo-like oxygen supply to cultured cells and thereby overcome inherent limitations of diffusional transport in conventional culture systems. In order to mimic the capillary network, cells are cultured on channeled elastomer scaffolds that are perfused with culture medium that can contain oxygen carriers. The overall protocol takes 2–4 weeks, including assembly of the perfusion systems, preparation of scaffolds, cell seeding and cultivation, and on-line and end-point assessment methods. This model is well suited for a wide range of cardiac tissue engineering applications, including the use of human stem cells, and high-fidelity models for biological research. PMID:18388955

  20. Induction of Inducible Nitric Oxide Synthase by Lipopolysaccharide and the Influences of Cell Volume Changes, Stress Hormones and Oxidative Stress on Nitric Oxide Efflux from the Perfused Liver of Air-Breathing Catfish, Heteropneustes fossilis.

    Directory of Open Access Journals (Sweden)

    Mahua G Choudhury

    Full Text Available The air-breathing singhi catfish (Heteropneustes fossilis is frequently being challenged by bacterial contaminants, and different environmental insults like osmotic, hyper-ammonia, dehydration and oxidative stresses in its natural habitats throughout the year. The main objectives of the present investigation were to determine (a the possible induction of inducible nitric oxide synthase (iNOS gene with enhanced production of nitric oxide (NO by intra-peritoneal injection of lipopolysaccharide (LPS (a bacterial endotoxin, and (b to determine the effects of hepatic cell volume changes due to anisotonicity or by infusion of certain metabolites, stress hormones and by induction of oxidative stress on production of NO from the iNOS-induced perfused liver of singhi catfish. Intra-peritoneal injection of LPS led to induction of iNOS gene and localized tissue specific expression of iNOS enzyme with more production and accumulation of NO in different tissues of singhi catfish. Further, changes of hydration status/cell volume, caused either by anisotonicity or by infusion of certain metabolites such as glutamine plus glycine and adenosine, affected the NO production from the perfused liver of iNOS-induced singhi catfish. In general, increase of hydration status/cell swelling due to hypotonicity caused decrease, and decrease of hydration status/cell shrinkage due to hypertonicity caused increase of NO efflux from the perfused liver, thus suggesting that changes in hydration status/cell volume of hepatic cells serve as a potent modulator for regulating the NO production. Significant increase of NO efflux from the perfused liver was also observed while infusing the liver with stress hormones like epinephrine and norepinephrine, accompanied with decrease of hydration status/cell volume of hepatic cells. Further, oxidative stress, caused due to infusion of t-butyl hydroperoxide and hydrogen peroxide separately, in the perfused liver of singhi catfish, resulted

  1. Perfusion dyssynchrony analysis

    NARCIS (Netherlands)

    Chiribiri, A.; Villa, A.D.M.; Sammut, E.; Breeuwer, M.; Nagel, E.

    2015-01-01

    AIMS: We sought to describe perfusion dyssynchrony analysis specifically to exploit the high temporal resolution of stress perfusion CMR. This novel approach detects differences in the temporal distribution of the wash-in of contrast agent across the left ventricular wall. METHODS AND RESULTS:

  2. Regional myocardial perfusion of cardioplegic solutions

    International Nuclear Information System (INIS)

    Eugene, J.; Lyons, K.P.; Ott, R.A.; Gelezunas, V.L.; Chang, C.W.; Kowall, M.G.; Haiduc, N.J.

    1987-01-01

    We compared the regional myocardial perfusion of blood cardioplegic solution (BCP) and crystalloid cardioplegic solution (CCP) in 14 mongrel dogs. Cardiopulmonary bypass was established at 28 degrees C, and a hydraulic occluder was placed around the proximal left anterior descending (LAD) coronary artery. In group 1 (N = 7) collateral coronary arteries were ligated; in group 2 (N = 7) collateral coronary arteries were left in situ. After the aorta was clamped, BCP and CCP were alternately perfused at 200 ml/min. The occluder was inflated to produce moderate, severe, and critical LAD stenosis, and regional perfusion was measured by xenon-133 washout with the Silicon Avalanche Radiation Detector. BCP infusion produced a consistently higher aortic pressure, but CCP flow was better than BCP flow under all conditions, particularly without coronary collaterals. Regional myocardial perfusion of CCP is superior to BCP

  3. Impact of intracoronary injection of mononuclear bone marrow cells in acute myocardial infarction on left ventricular perfusion and function: a 6-month follow-up gated 99mTc-MIBI single-photon emission computed tomography study

    International Nuclear Information System (INIS)

    Lipiec, Piotr; Krzeminska-Pakula, Maria; Plewka, Michal; Kasprzak, Jaroslaw D.; Kusmierek, Jacek; Plachcinska, Anna; Szuminski, Remigiusz; Robak, Tadeusz; Korycka, Anna

    2009-01-01

    We investigated the impact of intracoronary injection of autologous mononuclear bone marrow cells (BMC) in patients with acute ST elevation myocardial infarction (STEMI) on left ventricular volumes, global and regional systolic function and myocardial perfusion. The study included 39 patients with first anterior STEMI treated successfully with primary percutaneous coronary intervention. They were randomly assigned to the treatment group or the control group in a 2:1 ratio. The patients underwent baseline gated single-photon emission computed tomography (G-SPECT) 3-10 days after STEMI with quantitative and qualitative analysis of left ventricular perfusion and systolic function. On the following day, patients from the BMC treatment group were subjected to bone marrow aspiration, mononuclear BMC isolation and intracoronary injection. No placebo procedure was performed in the control group. G-SPECT was repeated 6 months after STEMI. Baseline and follow-up G-SPECT studies were available for 36 patients. At 6 months in the BMC group we observed a significantly enhanced improvement in the mean extent of the perfusion defect, the left ventricular perfusion score index, the infarct area perfusion score and the infarct area wall motion score index compared to the control group (p=0.01-0.04). However, the changes in left ventricular volume, ejection fraction and the left ventricular wall motion score index as well as the relative changes in the infarct area wall motion score index did not differ significantly between the groups. Intracoronary injection of autologous mononuclear BMC in patients with STEMI improves myocardial perfusion at 6 months. The benefit in infarct area systolic function is less pronounced and there is no apparent improvement of global left ventricular systolic function. (orig.)

  4. WE-G-18C-02: Estimation of Optimal B-Value Set for Obtaining Apparent Diffusion Coefficient Free From Perfusion in Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Karki, K; Hugo, G; Ford, J; Saraiya, S; Weiss, E [Radiation Oncology, Virginia Commonwealth University, Richmond, VA (United States); Olsen, K; Groves, R [Radiology, Virginia Commonwealth University, Richmond, VA (United States)

    2014-06-15

    Purpose: Diffusion-weighted MRI (DW-MRI) is increasingly being investigated for radiotherapy planning and response assessment. Selection of a limited number of b-values in DW-MRI is important to keep geometrical variations low and imaging time short. We investigated various b-value sets to determine an optimal set for obtaining monoexponential apparent diffusion coefficient (ADC) close to perfusion-insensitive intravoxel incoherent motion (IVIM) model ADC (ADCIVIM) in nonsmall cell lung cancer. Methods: Seven patients had 27 DW-MRI scans before and during radiotherapy in a 1.5T scanner. Respiratory triggering was applied to the echo-planar DW-MRI with TR=4500ms approximately, TE=74ms, pixel size=1.98X1.98mm{sub 2}, slice thickness=4–6mm and 7 axial slices. Diffusion gradients were applied to all three axes producing traceweighted images with eight b-values of 0–1000μs/μm{sup 2}. Monoexponential model ADC values using various b-value sets were compared to ADCIVIM using all b-values. To compare the relative noise in ADC maps, intra-scan coefficient of variation (CV) of active tumor volumes was computed. Results: ADCIVIM, perfusion coefficient and perfusion fraction for tumor volumes were in the range of 880-1622 μm{sup 2}/s, 8119-33834 μm{sup 2}/s and 0.104–0.349, respectively. ADC values using sets of 250, 800 and 1000; 250, 650 and 1000; and 250–1000μs/μm{sup 2} only were not significantly different from ADCIVIM(p>0.05, paired t-test). Error in ADC values for 0–1000, 50–1000, 100–1000, 250–1000, 500–1000, and three b-value sets- 250, 500 and 1000; 250, 650 and 1000; and 250, 800 and 1000μs/μm{sup 2} were 15.0, 9.4, 5.6, 1.4, 11.7, 3.7, 2.0 and 0.2% relative to the reference-standard ADCIVIM, respectively. Mean intrascan CV was 20.2, 20.9, 21.9, 24.9, 32.6, 25.8, 25.4 and 24.8%, respectively, whereas that for ADCIVIM was 23.3%. Conclusion: ADC values of two 3 b-value sets

  5. Estimation of optimal b-value sets for obtaining apparent diffusion coefficient free from perfusion in non-small cell lung cancer.

    Science.gov (United States)

    Karki, Kishor; Hugo, Geoffrey D; Ford, John C; Olsen, Kathryn M; Saraiya, Siddharth; Groves, Robert; Weiss, Elisabeth

    2015-10-21

    The purpose of this study was to determine optimal sets of b-values in diffusion-weighted MRI (DW-MRI) for obtaining monoexponential apparent diffusion coefficient (ADC) close to perfusion-insensitive intravoxel incoherent motion (IVIM) model ADC (ADCIVIM) in non-small cell lung cancer. Ten subjects had 40 DW-MRI scans before and during radiotherapy in a 1.5 T MRI scanner. Respiratory triggering was applied to the echo-planar DW-MRI with TR ≈ 4500 ms, TE  =  74 ms, eight b-values of 0-1000 μs μm(-2), pixel size  =  1.98 × 1.98 mm(2), slice thickness  =  6 mm, interslice gap  =  1.2 mm, 7 axial slices and total acquisition time ≈6 min. One or more DW-MRI scans together covered the whole tumour volume. Monoexponential model ADC values using various b-value sets were compared to reference-standard ADCIVIM values using all eight b-values. Intra-scan coefficient of variation (CV) of active tumour volumes was computed to compare the relative noise in ADC maps. ADC values for one pre-treatment DW-MRI scan of each of the 10 subjects were computed using b-value pairs from DW-MRI images synthesized for b-values of 0-2000 μs μm(-2) from the estimated IVIM parametric maps and corrupted by various Rician noise levels. The square root of mean of squared error percentage (RMSE) of the ADC value relative to the corresponding ADCIVIM for the tumour volume of the scan was computed. Monoexponential ADC values for the b-value sets of 250 and 1000; 250, 500 and 1000; 250, 650 and 1000; 250, 800 and 1000; and 250-1000 μs μm(-2) were not significantly different from ADCIVIM values (p > 0.05, paired t-test). Mean error in ADC values for these sets relative to ADCIVIM were within 3.5%. Intra-scan CVs for these sets were comparable to that for ADCIVIM. The monoexponential ADC values for other sets-0-1000; 50-1000; 100-1000; 500-1000; and 250 and 800 μs μm(-2) were significantly different from the ADCIVIM values. From Rician noise

  6. Repair of segmental bone defect using Totally Vitalized tissue engineered bone graft by a combined perfusion seeding and culture system.

    Directory of Open Access Journals (Sweden)

    Lin Wang

    Full Text Available BACKGROUND: The basic strategy to construct tissue engineered bone graft (TEBG is to combine osteoblastic cells with three dimensional (3D scaffold. Based on this strategy, we proposed the "Totally Vitalized TEBG" (TV-TEBG which was characterized by abundant and homogenously distributed cells with enhanced cell proliferation and differentiation and further investigated its biological performance in repairing segmental bone defect. METHODS: In this study, we constructed the TV-TEBG with the combination of customized flow perfusion seeding/culture system and β-tricalcium phosphate (β-TCP scaffold fabricated by Rapid Prototyping (RP technique. We systemically compared three kinds of TEBG constructed by perfusion seeding and perfusion culture (PSPC method, static seeding and perfusion culture (SSPC method, and static seeding and static culture (SSSC method for their in vitro performance and bone defect healing efficacy with a rabbit model. RESULTS: Our study has demonstrated that TEBG constructed by PSPC method exhibited better biological properties with higher daily D-glucose consumption, increased cell proliferation and differentiation, and better cell distribution, indicating the successful construction of TV-TEBG. After implanted into rabbit radius defects for 12 weeks, PSPC group exerted higher X-ray score close to autograft, much greater mechanical property evidenced by the biomechanical testing and significantly higher new bone formation as shown by histological analysis compared with the other two groups, and eventually obtained favorable healing efficacy of the segmental bone defect that was the closest to autograft transplantation. CONCLUSION: This study demonstrated the feasibility of TV-TEBG construction with combination of perfusion seeding, perfusion culture and RP technique which exerted excellent biological properties. The application of TV-TEBG may become a preferred candidate for segmental bone defect repair in orthopedic and

  7. Dynamic determination of kinetic parameters for the interaction between polypeptide hormones and cell-surface receptors in the perfused rat liver by the multiple-indicator dilution method

    International Nuclear Information System (INIS)

    Sato, H.; Sugiyama, Y.; Sawada, Y.; Iga, T.; Sakamoto, S.; Fuwa, T.; Hanano, M.

    1988-01-01

    Hepatic elimination of epidermal growth factor (EGF) via receptor-mediated endocytosis was studied by a multiple-indicator dilution method in the isolated perfused rat liver, in which cell polarity and spatial organization are maintained. In this method EGF was given with inulin, an extracellular reference, as a bolus into the portal vein, and dilution curves of both compounds in the hepatic vein effluent were analyzed. Analysis of the dilution curve for EGF, compared with that for somatostatin, which showed no specific binding to isolated liver plasma membranes, resulted as follows: (i) both extraction ratio and distribution volume of 125 I-labeled EGF decreased as the injected amount of unlabeled EGF increased; (ii) the ratio plot of the dilution curve for EGF exhibited an upward straight line initially for a short period of time, whereas the ratio plot of somatostatin gradually decreased. The multiple-indicator dilution method was used for other peptides also. Insulin and glucagon, known to have hepatocyte receptors, behaved similarly to EGF in shape of their ratio plots. The kinetic parameters calculated by this analysis were comparable with reported values obtained by in vitro direct binding measurements at equilibrium using liver homogenates. They conclude that the multiple-indicator dilution method is a good tool for analyzing the dynamics of peptide hormones-cell-surface receptor interaction under a condition in which spatial architecture of the liver is maintained

  8. Vicarious audiovisual learning in perfusion education.

    Science.gov (United States)

    Rath, Thomas E; Holt, David W

    2010-12-01

    Perfusion technology is a mechanical and visual science traditionally taught with didactic instruction combined with clinical experience. It is difficult to provide perfusion students the opportunity to experience difficult clinical situations, set up complex perfusion equipment, or observe corrective measures taken during catastrophic events because of patient safety concerns. Although high fidelity simulators offer exciting opportunities for future perfusion training, we explore the use of a less costly low fidelity form of simulation instruction, vicarious audiovisual learning. Two low fidelity modes of instruction; description with text and a vicarious, first person audiovisual production depicting the same content were compared. Students (n = 37) sampled from five North American perfusion schools were prospectively randomized to one of two online learning modules, text or video.These modules described the setup and operation of the MAQUET ROTAFLOW stand-alone centrifugal console and pump. Using a 10 question multiple-choice test, students were assessed immediately after viewing the module (test #1) and then again 2 weeks later (test #2) to determine cognition and recall of the module content. In addition, students completed a questionnaire assessing the learning preferences of today's perfusion student. Mean test scores from test #1 for video learners (n = 18) were significantly higher (88.89%) than for text learners (n = 19) (74.74%), (p audiovisual learning modules may be an efficacious, low cost means of delivering perfusion training on subjects such as equipment setup and operation. Video learning appears to improve cognition and retention of learned content and may play an important role in how we teach perfusion in the future, as simulation technology becomes more prevalent.

  9. Pulmonary perfusion ''without ventilation''

    International Nuclear Information System (INIS)

    Chapman, C.N.; Sziklas, J.J.; Spencer, R.P.; Rosenberg, R.J.

    1983-01-01

    An 88-yr-old man, with prior left upper lobectomy and phrenic nerve injury, had a ventilation/perfusion lung image. Both wash-in and equilibrium ventilation images showed no radioactive gas in the left lung. Nevertheless, the left lung was perfused. A similar result was obtained on a repeat study 8 days later. Delayed images, during washout, showed some radioactive gas in the left lung. Nearly absent ventilation (but continued perfusion) of that lung might have been related to altered gas dynamics brought about by the prior lobectomy, a submucosal bronchial lesion, phrenic nerve damage, and limited motion of the left part of the diaphragm. This case raises the issue of the degree of ventilation (and the phase relationship between the lungs) required for the entry of radioactive gas into a diseased lung, and the production of a ''reversed ventilation/perfusion mismatch.''

  10. Hepatic arterial perfusion increases in the early stage of severe acute pancreatitis patients: Evaluation by perfusion computed tomography

    International Nuclear Information System (INIS)

    Koyasu, Sho; Isoda, Hiroyoshi; Tsuji, Yoshihisa; Yamamoto, Hiroshi; Matsueda, Kazuhiro; Watanabe, Yuji; Chiba, Tsutomu; Togashi, Kaori

    2012-01-01

    Purpose: Although hepatic perfusion abnormalities have been reported in patients with acute pancreatitis, hepatic perfusion with severe acute pancreatitis (SAP) has not been quantitatively evaluated in humans. Therefore, we investigated hepatic perfusion in patients with SAP using perfusion CT. Materials and methods: Hepatic perfusion CT was performed in 67 patients with SAP within 3 days after symptom onset. The patients were diagnosed as having SAP according to the Atlanta criteria. Fifteen cases were established as a control group. Perfusion CT was obtained for 54 s beginning with a bolus injection of 40 ml of contrast agent (600–630 mgI/kg) at a flow rate of 4 ml/s. Perfusion data were analyzed by the dual-input maximum slope method to obtain hepatic arterial perfusion (HAP) and hepatic portal perfusion (HPP). Finally, we compared HAP and HPP in SAP patients with those in the control group, respectively. Results: Average HAP was significantly higher in SAP patients than in the control group (75.1 ± 38.0 vs. 38.2 ± 9.0 ml/min/100 ml; p < 0.001). There was no significant difference in average HPP between SAP patients and the control group (206.7 ± 54.9 vs. 204.4 ± 38.5 ml/min/100 ml; p = 0.92). Conclusion: Using quantitative analysis on perfusion CT, we first demonstrated an increase of HAP in the right hepatic lobe in SAP patients.

  11. Fabrication and perfusion culture of anatomically shaped artificial bone using stereolithography

    International Nuclear Information System (INIS)

    Du, Dajiang; Asaoka, Teruo; Ushida, Takashi; Furukawa, Katsuko S

    2014-01-01

    Because patient bone defects are usually varied and complicated in geometry, it would be preferred to fabricate custom-made artificial bone grafts that are anatomically specific to individual patient defects. Using a rabbit femoral segment as a bone reconstruction model, we successfully produced customized ceramic scaffolds by stereolithography, which not only had an anatomically correct external shape according to computed tomography data but also contained an interconnecting internal network of channels designed for perfusion culture. Rabbit bone marrow stromal cells were isolated and cultured with these scaffolds using a novel oscillatory perfusion system that was stereolithographically fabricated to fit well to the unique scaffold shapes. After five days of three-dimensional culture with oscillatory perfusion, the cells attached and proliferated homogenously in the scaffolds. However, control cells inside the scaffolds cultured under static conditions were dead after prolonged in vitro culture. Cellular DNA content and alkaline phosphatase activities were significantly higher in the perfusion group versus the static group. Therefore, anatomically correct artificial bone can be successfully constructed using stereolithography and oscillatory culture technology, and could be useful for bone engraftment and defect repair. (paper)

  12. Effect of mobilization of bone marrow stem cells by granulocyte colony stimulating factor on clinical symptoms, left ventricular perfusion and function in patients with severe chronic ischemic heart disease

    DEFF Research Database (Denmark)

    Wang, Yongzhong; Tägil, Kristina; Ripa, Rasmus S.

    2005-01-01

    . Myocardial perfusion was unchanged at adenosine stress single photon emission computerized tomography (SPECT) or magnetic resonance images (MRI). Left ventricular ejection fraction decreased from 57% to 52% (p... with echocardiography. CONCLUSIONS: Treatment by G-CSF improved symptoms but not signs of myocardial ischemia in patients with severe IHD. The effects seemed related to mobilization of stem cells. An adverse effect on ejection fraction could not be excluded...

  13. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

  14. Transplantation of Rat Mesenchymal Stem Cells Overexpressing Hypoxia-Inducible Factor 2α Improves Blood Perfusion and Arteriogenesis in a Rat Hindlimb Ischemia Model

    Directory of Open Access Journals (Sweden)

    Weifeng Lu

    2017-01-01

    Full Text Available Mesenchymal stem cells (MSCs have been increasingly tested in cell-based therapy to treat numerous diseases. Genetic modification to improve MSC behavior may enhance posttransplantation outcome. This study aims to test the potential therapeutic benefits of rat bone marrow MSCs overexpressing hypoxia-inducible factor 2α (rMSCsHIF-2α in a rat hindlimb ischemia model. PBS, rMSCs, or rMSCsHIF-2α were injected into rat ischemic hindlimb. Compared with the injection of PBS or rMSCs, transplantation of rMSCsHIF-2α significantly improved blood perfusion, increased the number of vessel branches in the muscle of the ischemic hindlimb, and improved the foot mobility of the ischemic hindlimb (all P<0.05. rMSCHIF-2α transplantation also markedly increased the expression of proangiogenic factors VEGF, bFGF, and SDF1 and Notch signaling proteins including DII4, NICD, Hey1, and Hes1, whereas it reduced the expression of proapoptotic factor Bax in the muscle of the ischemic hindlimb. Overexpression of HIF-2α did not affect rMSC stemness and proliferation under normoxia but significantly increased rMSC migration and tube formation in matrigel under hypoxia (all P<0.05. RMSCsHIF-2α stimulated endothelial cell invasion under hypoxia significantly (P<0.05. Genetic modification of rMSCs via overexpression of HIF-2α improves posttransplantation outcomes in a rat hindlimb ischemia model possibly by stimulating proangiogenic growth factors and cytokines.

  15. Phase 1 Trial of Bevacizumab With Concurrent Chemoradiation Therapy for Squamous Cell Carcinoma of the Head and Neck With Exploratory Functional Imaging of Tumor Hypoxia, Proliferation, and Perfusion

    International Nuclear Information System (INIS)

    Nyflot, Matthew J.; Kruser, Tim J.; Traynor, Anne M.; Khuntia, Deepak; Yang, David T.; Hartig, Gregory K.; McCulloch, Timothy M.; Wiederholt, Peggy A.; Gentry, Lindell R.; Hoang, Tien; Jeraj, Robert

    2015-01-01

    Purpose: A phase 1 trial was completed to examine the safety and feasibility of combining bevacizumab with radiation and cisplatin in patients with locoregionally advanced squamous cell carcinoma of the head and neck (HNSCC) treated with curative intent. Additionally, we assessed the capacity of bevacizumab to induce an early tumor response as measured by a series of biological imaging studies. Methods and Materials: All patients received a single induction dose of bevacizumab (15 mg/kg) delivered 3 weeks (±3 days) before the initiation of chemoradiation therapy. After the initial dose of bevacizumab, comprehensive head and neck chemoradiation therapy was delivered with curative intent to 70 Gy in 33 fractions with concurrent weekly cisplatin at 30 mg/m 2 and bevacizumab every 3 weeks (weeks 1, 4, 7) with dose escalation from 5 to 10 to 15 mg/kg. All patients underwent experimental imaging with [ 18 F]fluorothymidine positron emission tomography (FLT-PET) (proliferation), [ 61 Cu]Cu-diacetyl-bis(N4-methylthiosemicarbazone) PET (Cu-ATSM-PET) (hypoxia), and dynamic contrast-enhanced computed tomography (DCE-CT) (perfusion) at 3 time points: before bevacizumab monotherapy, after bevacizumab monotherapy, and during the combined therapy course. Results: Ten patients were enrolled. All had stage IV HNSCC, all achieved a complete response to treatment, and 9 of 10 remain alive, with a mean survival time of 61.3 months. All patients experienced grade 3 toxicity, but no dose-limiting toxicities or significant bleeding episodes were observed. Significant reductions were noted in tumor proliferation (FLT-PET), tumor hypoxia (Cu-ATSM-PET), and DCE-CT contrast enhancement after bevacizumab monotherapy, with further decreases in FLT-PET and Cu-ATSM-PET during the combined therapy course. Conclusions: The incorporation of bevacizumab into comprehensive chemoradiation therapy regimens for patients with HNSCC appears safe and feasible. Experimental imaging demonstrates

  16. Phase 1 Trial of Bevacizumab With Concurrent Chemoradiation Therapy for Squamous Cell Carcinoma of the Head and Neck With Exploratory Functional Imaging of Tumor Hypoxia, Proliferation, and Perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Nyflot, Matthew J., E-mail: nyflot@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Kruser, Tim J. [Department of Radiation Oncology, Cadence Cancer Center at Delnor Hospital, Geneva, Illinois (United States); Traynor, Anne M. [Department of Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Khuntia, Deepak [Varian Medical Systems, Palo Alto, California (United States); Yang, David T. [Departments of Pathology and Laboratory Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Hartig, Gregory K.; McCulloch, Timothy M. [Department of Surgery-Otolaryngology, H& N Surgery Division, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Wiederholt, Peggy A. [Department of Human Oncology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Gentry, Lindell R. [Department of Radiology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Hoang, Tien [Department of Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Jeraj, Robert [Department of Human Oncology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Department of Radiology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Department of Medical Physics, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); and others

    2015-04-01

    Purpose: A phase 1 trial was completed to examine the safety and feasibility of combining bevacizumab with radiation and cisplatin in patients with locoregionally advanced squamous cell carcinoma of the head and neck (HNSCC) treated with curative intent. Additionally, we assessed the capacity of bevacizumab to induce an early tumor response as measured by a series of biological imaging studies. Methods and Materials: All patients received a single induction dose of bevacizumab (15 mg/kg) delivered 3 weeks (±3 days) before the initiation of chemoradiation therapy. After the initial dose of bevacizumab, comprehensive head and neck chemoradiation therapy was delivered with curative intent to 70 Gy in 33 fractions with concurrent weekly cisplatin at 30 mg/m{sup 2} and bevacizumab every 3 weeks (weeks 1, 4, 7) with dose escalation from 5 to 10 to 15 mg/kg. All patients underwent experimental imaging with [{sup 18}F]fluorothymidine positron emission tomography (FLT-PET) (proliferation), [{sup 61}Cu]Cu-diacetyl-bis(N4-methylthiosemicarbazone) PET (Cu-ATSM-PET) (hypoxia), and dynamic contrast-enhanced computed tomography (DCE-CT) (perfusion) at 3 time points: before bevacizumab monotherapy, after bevacizumab monotherapy, and during the combined therapy course. Results: Ten patients were enrolled. All had stage IV HNSCC, all achieved a complete response to treatment, and 9 of 10 remain alive, with a mean survival time of 61.3 months. All patients experienced grade 3 toxicity, but no dose-limiting toxicities or significant bleeding episodes were observed. Significant reductions were noted in tumor proliferation (FLT-PET), tumor hypoxia (Cu-ATSM-PET), and DCE-CT contrast enhancement after bevacizumab monotherapy, with further decreases in FLT-PET and Cu-ATSM-PET during the combined therapy course. Conclusions: The incorporation of bevacizumab into comprehensive chemoradiation therapy regimens for patients with HNSCC appears safe and feasible. Experimental imaging

  17. Increased perfusion pressure enhances the expression of endothelin (ETB) and angiotensin II (AT1, AT2) receptors in rat mesenteric artery smooth muscle cells

    DEFF Research Database (Denmark)

    Lindstedt, Isak; Xu, Cang-Bao; Zhang, Yaping

    2009-01-01

    and luminally perfused in a perfusion chamber. After either exposure to no ("organ culture" (0 mmHg)), normal (85/75 mmHg) or high pressure (160/150 mmHg) at constant flow for 1-17 h, the vessel segments were snap frozen and real-time polymerase chain reaction was performed to quantify the ET- and AT-receptor m...

  18. Scintigraphic and MR perfusion imaging in preoperative evaluation for lung volume reduction surgery. Pilot study results

    International Nuclear Information System (INIS)

    Johkoh, Takeshi; Mueller, N.L.; Kavanagh, P.V

    2000-01-01

    To compare MR perfusion imaging with perfusion scintigraphy in the evaluation of patients with pulmonary emphysema being considered for lung volume reduction surgery. Six patients with pulmonary emphysema and two normal individuals were evaluated by MR perfusion imaging, perfusion scintigraphy, and selective bilateral pulmonary angiography. MR images were obtained with an enhanced fast gradient recalled echo with three-dimensional Fourier transformation technique (efgre 3D) (6.3/1.3; flip angle, 30 deg C; field of view, 45-48 cm; matrix, 256 x 160). The presence or absence of perfusion defects in each segment was evaluated by two independent observers. Using angiography as the gold standard, the sensitivity, specificity, and accuracy of MR perfusion imaging in detecting focal perfusion abnormalities were 90%, 87%, and 89%, respectively, while those of perfusion scintigraphy were 71%, 76%, and 71%, respectively. The diagnostic accuracy of MR perfusion imaging was significantly higher than that of scintigraphy (p<0.001, McNemar test). There was good agreement between two observers for MR perfusion imaging (kappa statistic, 0.66) and only moderate agreement for perfusion scintigraphy (kappa statistic, 0.51). MR perfusion imaging is superior to perfusion scintigraphy in the evaluation of pulmonary parenchymal perfusion in patients with pulmonary emphysema. (author)

  19. Perfusion MRI in CNS disease: current concepts

    International Nuclear Information System (INIS)

    Essig, M.; Giesel, F.; Le-Huu, M.; Stieltjes, B.; Tengg, H. von; Weber, M.-A.

    2004-01-01

    Today there are several indications for cerebral perfusion MRI. The major indications routinely used in increasing numbers of imaging centers include cerebrovascular disease, tumor imaging and recently psychiatric disorders. Perfusion MRI is based on the injection of a gadolinium chelate and the rapid acquisition of images as the bolus of contrast agent passes through the blood vessels in the brain. The contrast agent causes a signal change; this signal change over time can be analysed to measure cerebral hemodynamics. The quality of brain perfusion studies is very dependent on the contrast agent used: a robust and strong signal decrease with a compact bolus is needed. MultiHance (gadobenate dimeglumine, Gd-BOPTA) is the first of a new class of paramagnetic MR contrast agents with a weak affinity for serum proteins. Due to the interaction of Gd-BOPTA with serum albumin, MultiHance presents with significantly higher T1- and T2-relaxivities enabling a sharper bolus profile. This article reviews the indications of perfusion MRI and the performance of MultiHance in MR perfusion of different diseases. Previous studies using perfusion MRI for a variety of purposes required the use of double dose of contrast agent to achieve a sufficiently large signal drop to enable the acquisition of a clear input function and the calculation of perfusion rCBV and rCBF maps of adequate quality. Recent studies with Multi-Hance suggest that only a single dose of this agent is needed to cause a signal drop of about 30% which is sufficient to allow the calculation of high quality rCBV and rCBF maps. (orig.)

  20. Modeling placental transport: correlation of in vitro BeWo cell permeability and ex vivo human placental perfusion

    DEFF Research Database (Denmark)

    Poulsen, Marie Sønnegaard; Rytting, Erik; Mose, Tina

    2009-01-01

    across the BeWo cells was observed in the rank order of caffeine>antipyrine>benzoic acid>glyphosate in terms of both the apparent permeability coefficient and the initial slope, defined as the linear rate of substance transferred to the fetal compartment as percent per time, a parameter used to compare...

  1. Isolated limb perfusion electrochemotherapy for the treatment of an advanced squamous cell carcinoma of the hoof in a mare

    OpenAIRE

    Spugnini, Enrico Pierluigi; Bolaffio, Carlo; Scacco, Licia; Baldi, Alfonso

    2017-01-01

    A twenty-year-old female saddle horse was referred for evaluation of a seven month, non-healing erosive lesion of the right hind hoof with proliferation and bleeding of the underlying soft tissues. This lesion had been twice surgically treated as a canker but rapidly recurred. Histological examination of the second excision revealed a well-differentiated squamous cell carcinoma. At presentation, the horse was mildly depressed, lame and partially non-weight-bearing on the right hind leg, which...

  2. Arterially perfused neurosphere-derived cells distribute outside the ischemic core in a model of transient focal ischemia and reperfusion in vitro.

    Directory of Open Access Journals (Sweden)

    Chiara Pastori

    Full Text Available BACKGROUND: Treatment with neural stem cells represents a potential strategy to improve functional recovery of post-ischemic cerebral injury. The potential benefit of such treatment in acute phases of human ischemic stroke depends on the therapeutic viability of a systemic vascular delivery route. In spite of the large number of reports on the beneficial effects of intracerebral stem cells injection in experimental stroke, very few studies demonstrated the effectiveness of the systemic intravenous delivery approach. METODOLOGY/PRINCIPAL FINDINGS: We utilized a novel in vitro model of transient focal ischemia to analyze the brain distribution of neurosphere-derived cells (NCs in the early 3 hours that follow transient occlusion of the medial cerebral artery (MCA. NCs obtained from newborn C57/BL6 mice are immature cells with self-renewal properties that could differentiate into neurons, astrocytes and oligodendrocytes. MCA occlusion for 30 minutes in the in vitro isolated guinea pig brain preparation was followed by arterial perfusion with 1x10(6 NCs charged with a green fluorescent dye, either immediately or 60 minutes after reperfusion onset. Changes in extracellular pH and K(+ concentration during and after MCAO were measured through ion-sensitive electrodes. CONCLUSION/SIGNIFICANCE: It is demonstrated that NCs injected through the vascular system do not accumulate in the ischemic core and preferentially distribute in non-ischemic areas, identified by combined electrophysiological and morphological techniques. Direct measurements of extracellular brain ions during and after MCA occlusion suggest that anoxia-induced tissue changes, such as extracellular acidosis, may prevent NCs from entering the ischemic area in our in vitro model of transitory focal ischemia and reperfusion suggesting a role played by the surrounding microenviroment in driving NCs outside the ischemic core. These findings strongly suggest that the potential beneficial effect

  3. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells

    Energy Technology Data Exchange (ETDEWEB)

    Brun, Nadja Rebecca [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Wehrli, Bernhard [Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland); Fent, Karl, E-mail: karl.fent@fhnw.ch [University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132 Muttenz (Switzerland); Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitätsstrasse 16, CH-8092 Zürich (Switzerland)

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L{sup −1} molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L{sup −1}. From OPV, copper (14 μg L{sup −1}), zinc (87 μg L{sup −1}) and silver (78 μg L{sup −1}) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. - Highlights: • Photovoltaics may be disposed in the environment after usage. • Copper indium gallium selenide (CIGS) and organic (OPV) cells were compared. • Morphological and molecular effects were assessed in zebrafish embryos. • Environmental condition affected metal leaching and ecotoxicological activity. • Damaged CIGS cells pose higher risk to the environment than OPV cells.

  4. Reverse ventilation--perfusion mismatch

    International Nuclear Information System (INIS)

    Palmaz, J.C.; Barnett, C.A.; Reich, S.B.; Krumpe, P.E.; Farrer, P.A.

    1984-01-01

    Patients having lobar airway obstruction or consolidation usually have decreases of both ventilation and perfusion on lung scans. We report three patients in whom hypoxic vasoconstriction was apparently incomplete, resulting in a ''reversed'' ventilation-perfusion mismatch. Perfusion of the hypoxic lobe on the radionuclide scan was associated with metabolic alkalosis, pulmonary venous and pulmonary arterial hypertension in these patients

  5. Hepatic artery perfusion imaging

    International Nuclear Information System (INIS)

    Thrall, J.H.; Gyves, J.W.; Ziessman, H.A.; Ensminger, W.D.

    1985-01-01

    Organ and region-selective intra-arterial chemotherapy have been used for more than two decades to treat malignant neoplasms in the extremities, head and neck region, pelvis, liver, and other areas. Substantial evidence of improved response to regional chemotherapy now exists, but there are stringent requirements for successful application of the regional technique. First, the chemotherapeutic agent employed must have appropriate pharmacokinetic and pharmacodynamic properties. Second, the drug must be reliably delivered to the tumor-bearing area. This typically requires an arteriographic assessment of the vascular supply of the tumor, followed by placement of a therapeutic catheter and confirmation that the ''watershed'' perfusion distribution from the catheter truly encompasses the tumor. Optimal catheter placement also minimizes perfusion of nontarget organs. Radionuclide perfusion imaging with technetium 99m-labeled particles, either microspheres or macroaggregates of albumin, has become the method of choice for making these assessments. Catheter placement itself is considered by many to represent a type of ''therapeutic'' intervention. However, once the catheter is in the hepatic artery the radionuclide perfusion technique can be used to assess adjunctive pharmacologic maneuvers designed to further exploit the regional approach to chemotherapy. This chapter presents the technetium Tc 99m macroaggregated albumin method for assessing catheter placement and the pharmacokinetic rationale for regional chemotherapy, and discusses two promising avenues for further intervention

  6. Extremity perfusion for sarcoma

    NARCIS (Netherlands)

    Hoekstra, Harald Joan

    2008-01-01

    For more than 50 years, the technique of extremity perfusion has been explored in the limb salvage treatment of local, recurrent, and multifocal sarcomas. The "discovery" of tumor necrosis factor-or. in combination with melphalan was a real breakthrough in the treatment of primarily irresectable

  7. Isolated limb perfusion.

    Science.gov (United States)

    Gillespie, Rosalyn; Chantier, Nariane

    1994-12-08

    Growing concern over the rising incidence of malignant melanoma has brought about a need for information on this disorder and the treatment available. Isolated limb perfusion is a relatively new technique used in only a few hospitals. An increased knowledge base will lead to a better understanding of the nursing care required and to a more in-depth care plan.

  8. Kupffer cell depletion attenuates leptin-mediated methoxamine-stimulated portal perfusion pressure and thromboxane A2 release in a rodent model of NASH-cirrhosis.

    Science.gov (United States)

    Yang, Ying-Ying; Huang, Yi-Tsau; Tsai, Tung-Hu; Hou, Ming-Chih; Lee, Fa-Yauh; Lee, Shou-Dong; Lin, Han-Chieh

    2012-12-01

    Cirrhotic portal hypertension is characterized by increased hepatic oxidative stress, AA (arachidonic acid)-derived TXA(2) (thromboxane A(2)) release and exaggerated hepatic response to the α-adrenergic agonist MTX (methoxamine). Besides promoting hepatic fibrosis, the role of hyperleptinaemia in the modulation of vascular response in NASH (non-alcoholic steatohepatitis) rat livers remains unknown. The aim of the present study was to explore the possible links between hyperleptinaemia and the disarrangement in the hepatic microcirculation. NASH-cirrhosis with hyperleptinaemia was induced in lean rats by feeding with an HF/MCD (high-fat/methionine-choline-deficient) diet. Portal haemodynamics, various substances, protein and mRNA expression and PUFA (polyunsaturated fatty acid) composition were measured. Finally, the effects of leptin pre-infusion on TXA(2) release and concentration-PPP (portal perfusion pressure) curves in response to MTX were evaluated by simultaneously pre-treatment with the Kupffer cell inactivators GdCl(3) (gadolinium chloride) or EC (encapsulated clodronate), the TXS (TXA(2) synthase) inhibitor furegrelate, the TP receptor (TXA(2) receptor) antagonist SQ29548 and the dual TXS/TP receptor antagonist BM567. In HF/MCD+leptin-lean rats, cirrhosis-induced PPP and MTX hyper-responsiveness were associated with increased hepatic TXA(2) production, TBARS (thiobarbituric acid-reacting substances) levels and the AA (arachidonic acid)/n-3 PUFA ratio, and up-regulation of hepatic leptin, FAS (fatty acid synthase), NADPH oxidase subunits, TXS, TP receptor, TGFβ(1) (transforming growth factor β(1)) proteins and mRNAs. Pre-infusion of leptin significantly enhanced MTX-stimulated PPP elevation and TXA(2) release, which were attenuated by GdCl(3) and EC pre-treatment. Concomitantly pre-incubation with BM567, but not furegrelate or SQ29548, significantly abolished the leptin-enhanced MTX-stimulated increase in PPP in NASH-cirrhotic rats. Hyperleptinaemia

  9. Spatial relationship between tumor perfusion and endogeneous glucose distribution

    International Nuclear Information System (INIS)

    Schroeder, T.; Larrier, N.; Viglianti, B.; Rabbani, Z.N.; Peltz, C.; Vujascovic, Z.; Dewhirst, M.W.

    2003-01-01

    Earlier studies detecting glucose in tissue and solid tumors by bioluminescence imaging suggested, that glucose distribution patterns may be spatially related to functional vascularity. The purpose of this study was to evaluate this relationship by comparing glucose distribution patterns as determined by bioluminescence imaging to perfusion patterns of endogeneous Hoechst 33342 in rats bearing mammary carcinomas. R 3230 mammary carcinoma cells have been implanted subcutaneously into 7 female Fischer 344 rats. Two months post implantation, after injection of Hoechst 33342 the tumors were removed and snap frozen to conserve metabolite levels. Concomitantly, blood was sampled from the animals for analysis of glucose concentrations using a micodialysis analyzer. Cryosections of the tumors have been prepared, and every slice has been analyzed for both, Hoechst binding by fluorescence microscopy, and for glucose distribution patterns using bioluminescence imaging. In many cases vascular structures could be retrieved by the spatial pattern of glucose distribution. In some cases however, higher glucose concentrations could be found independent from Hoechst signal. On the other hand, regions of high Hoechst signal are not necessarily correlated with high glucose concentrations. When comparing blood and tissue glucose levels, tissue glucose content as measured with bioluminescence imaging (1.9-3.5 mM) is considerably lower than blood glucose (5.6-8.0 mM), demonstrating the expected gradient from blood to tissue. This study demonstrates the feasibility of monitoring glucose gradients in relation to functional vasculature throughout the body, from blood down to tissue or tumor and further, throughout the microenvironment of the solid tumor. Glucose distribution patterns may be an important tool in perfusion studies, e. g. in detecting the direction of blood flow in ex-vivo samples or in estimating glucose consumption rates of tumor cells adjacent to or in between perfused

  10. Higher order mode damping in a five-cell superconducting rf cavity with a photonic band gap coupler cell

    Science.gov (United States)

    Arsenyev, Sergey A.; Temkin, Richard J.; Shchegolkov, Dmitry Yu.; Simakov, Evgenya I.; Boulware, Chase H.; Grimm, Terry L.; Rogacki, Adam R.

    2016-08-01

    We present a study of higher order mode (HOM) damping in the first multicell superconducting radio-frequency (SRF) cavity with a photonic band gap (PBG) coupler cell. Achieving higher average beam currents is particularly desirable for future light sources and particle colliders based on SRF energy-recovery linacs (ERLs). Beam current in ERLs is limited by the beam breakup instability, caused by parasitic HOMs interacting with the beam in accelerating cavities. A PBG cell incorporated in an accelerating cavity can reduce the negative effect of HOMs by providing a frequency selective damping mechanism, thus allowing significantly higher beam currents. The five-cell cavity with a PBG cell was designed and optimized for HOM damping. Monopole and dipole HOMs were simulated. The SRF cavity was fabricated and tuned. External quality factors for some HOMs were measured in a cold test. The measurements agreed well with the simulations.

  11. Higher order mode damping in a five-cell superconducting rf cavity with a photonic band gap coupler cell

    Directory of Open Access Journals (Sweden)

    Sergey A. Arsenyev

    2016-08-01

    Full Text Available We present a study of higher order mode (HOM damping in the first multicell superconducting radio-frequency (SRF cavity with a photonic band gap (PBG coupler cell. Achieving higher average beam currents is particularly desirable for future light sources and particle colliders based on SRF energy-recovery linacs (ERLs. Beam current in ERLs is limited by the beam breakup instability, caused by parasitic HOMs interacting with the beam in accelerating cavities. A PBG cell incorporated in an accelerating cavity can reduce the negative effect of HOMs by providing a frequency selective damping mechanism, thus allowing significantly higher beam currents. The five-cell cavity with a PBG cell was designed and optimized for HOM damping. Monopole and dipole HOMs were simulated. The SRF cavity was fabricated and tuned. External quality factors for some HOMs were measured in a cold test. The measurements agreed well with the simulations.

  12. Common themes and cell type specific variations of higher order chromatin arrangements in the mouse

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    Cremer Thomas

    2005-12-01

    Full Text Available Abstract Background Similarities as well as differences in higher order chromatin arrangements of human cell types were previously reported. For an evolutionary comparison, we now studied the arrangements of chromosome territories and centromere regions in six mouse cell types (lymphocytes, embryonic stem cells, macrophages, fibroblasts, myoblasts and myotubes with fluorescence in situ hybridization and confocal laser scanning microscopy. Both species evolved pronounced differences in karyotypes after their last common ancestors lived about 87 million years ago and thus seem particularly suited to elucidate common and cell type specific themes of higher order chromatin arrangements in mammals. Results All mouse cell types showed non-random correlations of radial chromosome territory positions with gene density as well as with chromosome size. The distribution of chromosome territories and pericentromeric heterochromatin changed during differentiation, leading to distinct cell type specific distribution patterns. We exclude a strict dependence of these differences on nuclear shape. Positional differences in mouse cell nuclei were less pronounced compared to human cell nuclei in agreement with smaller differences in chromosome size and gene density. Notably, the position of chromosome territories relative to each other was very variable. Conclusion Chromosome territory arrangements according to chromosome size and gene density provide common, evolutionary conserved themes in both, human and mouse cell types. Our findings are incompatible with a previously reported model of parental genome separation.

  13. A capillary-based perfusion phantom for simulation of brain perfusion for MRI

    International Nuclear Information System (INIS)

    Maciak, A.; Kronfeld, A.; Mueller-Forell, W.; Wille, C.; Kempski, O.; Stoeter, P.

    2010-01-01

    Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

  14. NAC selectively inhibit cancer telomerase activity: A higher redox homeostasis threshold exists in cancer cells

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    Pengying Li

    2016-08-01

    Full Text Available Telomerase activity controls telomere length, and this plays an important role in stem cells, aging and tumors. Antioxidant was shown to protect telomerase activity in normal cells but inhibit that in cancer cells, but the underlying mechanism is elusive. Here we found that 7721 hepatoma cells held a higher redox homeostasis threshold than L02 normal liver cells which caused 7721 cells to have a higher demand for ROS; MnSOD over-expression in 7721 decreased endogenous reactive oxygen species (ROS and inhibited telomerase activity; Akt phosphorylation inhibitor and NAC both inhibited 7721 telomerase activity. The over-elimination of ROS by NAC resulted in the inhibition of Akt pathway. Our results suggest that ROS is involved in the regulation of cancer telomerase activity through Akt pathway. The different intracellular redox homeostasis and antioxidant system in normal cells and tumor cells may be the cause of the opposite effect on telomerase activity in response to NAC treatment. Our results provide a theoretical base of using antioxidants selectively inhibit cancer telomerase activity. Findings of the present study may provide insights into novel approaches for cancer treatment.

  15. Dynamic volume perfusion CT in patients with lung cancer: Baseline perfusion characteristics of different histological subtypes

    International Nuclear Information System (INIS)

    Shi, Jingyun; Schmid-Bindert, Gerald; Fink, Christian; Sudarski, Sonja; Apfaltrer, Paul; Pilz, Lothar R.; Liu, Bo; Haberland, Ulrike; Klotz, Ernst

    2013-01-01

    Objective: To evaluate dynamic volume perfusion CT (dVPCT) tumor baseline characteristics of three different subtypes of lung cancer in untreated patients. Materials and methods: 173 consecutive patients (131 men, 42 women; mean age 61 ± 10 years) with newly diagnosed lung cancer underwent dVPCT prior to biopsy. Tumor permeability, blood flow (BF), blood volume (BV) and mean transit time (MTT) were quantitatively assessed as well as tumor diameter and volume. Tumor subtypes were histologically determined and compared concerning their dVPCT results. dVPCT results were correlated to tumor diameter and volume. Results: Histology revealed adenocarcinoma in 88, squamous cell carcinoma in 54 and small cell lung cancer (SCLC) in 31 patients. Tumor permeability was significantly differing between adenocarcinoma, squamous cell carcinoma and SCLC (all p < 0.05). Tumor BF and BV were higher in adenocarcinomathan in SCLC (p = 0.001 and p = 0.0002 respectively). BV was also higher in squamous cell carcinoma compared to SCLC (p = 0.01). MTT was not differing between tumor subtypes. Regarding all tumors, tumor diameter did not correlate with any of the dVPCT parameters, whereas tumor volume was negatively associated with permeability, BF and BV (r = −0.22, −0.24, −0.24, all p < 0.05). In squamous cell carcinoma, tumor diameter und volume correlated with BV (r = 0.53 and r = −0.40, all p < 0.05). In SCLC, tumor diameter und volume correlated with MTT (r = 0.46 and r = 0.39, all p < 0.05). In adenocarcinoma, no association between morphological and functional tumor characteristics was observed. Conclusions: dVPCT parameters are only partially related to tumor diameter and volume and are significantly differing between lung cancer subtypes

  16. Acid perfusion test in gastroesophageal reflux disease

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

    1986-01-01

    An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness.

  17. Intra-Arterial MR Perfusion Imaging of Meningiomas: Comparison to Digital Subtraction Angiography and Intravenous MR Perfusion Imaging.

    Directory of Open Access Journals (Sweden)

    Mark A Lum

    Full Text Available To evaluate the ability of IA MR perfusion to characterize meningioma blood supply.Studies were performed in a suite comprised of an x-ray angiography unit and 1.5T MR scanner that permitted intraprocedural patient movement between the imaging modalities. Patients underwent intra-arterial (IA and intravenous (IV T2* dynamic susceptibility MR perfusion immediately prior to meningioma embolization. Regional tumor arterial supply was characterized by digital subtraction angiography and classified as external carotid artery (ECA dural, internal carotid artery (ICA dural, or pial. MR perfusion data regions of interest (ROIs were analyzed in regions with different vascular supply to extract peak height, full-width at half-maximum (FWHM, relative cerebral blood flow (rCBF, relative cerebral blood volume (rCBV, and mean transit time (MTT. Linear mixed modeling was used to identify perfusion curve parameter differences for each ROI for IA and IV MR imaging techniques. IA vs. IV perfusion parameters were also directly compared for each ROI using linear mixed modeling.18 ROIs were analyzed in 12 patients. Arterial supply was identified as ECA dural (n = 11, ICA dural (n = 4, or pial (n = 3. FWHM, rCBV, and rCBF showed statistically significant differences between ROIs for IA MR perfusion. Peak Height and FWHM showed statistically significant differences between ROIs for IV MR perfusion. RCBV and MTT were significantly lower for IA perfusion in the Dural ECA compared to IV perfusion. Relative CBF in IA MR was found to be significantly higher in the Dural ICA region and MTT significantly lower compared to IV perfusion.

  18. Higher positive identification of malignant CSF cells using the cytocentrifuge than the Suta chamber

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    Sérgio Monteiro de Almeida

    Full Text Available ABSTRACT Objective To define how to best handle cerebrospinal fluid (CSF specimens to obtain the highest positivity rate for the diagnosis of malignancy, comparing two different methods of cell concentration, sedimentation and cytocentrifugation. Methods A retrospective analysis of 411 CSF reports. Results This is a descriptive comparative study. The positive identification of malignant CSF cells was higher using the centrifuge than that using the Suta chamber (27.8% vs. 19.0%, respectively; p = 0.038. Centrifuge positively identified higher numbers of malignant cells in samples with a normal concentration of white blood cells (WBCs (< 5 cells/mm3 and with more than 200 cells/mm3, although this was not statistically significant. There was no lymphocyte loss using either method. Conclusions Cytocentrifugation positively identified a greater number of malignant cells in the CSF than cytosedimentation with the Suta chamber. However, there was no difference between the methods when the WBC counts were within the normal range.

  19. Differing strategies of patterning of follicular cells in higher and lower brachycerans (Diptera: Brachycera).

    Science.gov (United States)

    Tworzydlo, Waclaw; Jablonska, Anna; Kisiel, Elzbieta; Bilinski, Szczepan M

    2005-10-01

    In all higher dipterans (Brachycera), including the fruitfly, Drosophila melanogaster, each egg chamber (ovarian follicle) consists of a group (clone) of germ cells (one oocyte and 15 accompanying nurse cells) that is surrounded by a layer of somatic mesodermal follicular cells (FCs). As oogenesis progresses the initially uniform FCs diversify into several morphologically and functionally distinct subpopulations. In D. melanogaster some of these subpopulations, e.g., border, centripetal, and dorsolateral cells, undertake coordinated migration or rearrangement over the surface of the germ cells. During the final stages of oogenesis these subpopulations participate in the formation of a complex, regionally specialized eggshell. In representatives of lower brachycerans (Orthorrhapha), only FCs that undertake active, directed migration are the border cells. These cells originate at the anterior pole of the ovarian follicle and migrate between the nurse cells to the anterior pole of the oocyte. Reduced motility of FCs in lower brachycerans results in the absence of certain FC subpopulations in their egg chambers and subsequent simplicity of their eggshells. We found that the lack of some FC subpopulations coincided with the appearance of lamellipodium-like protrusions of the oocyte. These protrusions penetrated between the apposing membranes of nurse and FCs and partially enveloped the nurse cell compartment. Analysis of whole-mount preparations stained with rhodamine-conjugated phalloidin revealed that the protrusions contained microfilaments and that their tips were equipped with actin-rich filopodium-like processes. We also found that in some lower brachycerans (representatives of the family Rhagionidae), the FCs located at the posterior pole of the oocyte, became enlarged and morphologically similar to the anterior border cells. These findings indicate that in higher dipterans the processes leading to the formation of a functional egg are variable and often markedly

  20. Higher Regional Court Celle, judgment of December 9, 1986 (legal term of radioactive waste)

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    In its decision of December 9, 1986, the Higher Regional Court in Celle deals with the legal term of radioactive waste. The definition does not result from sec. 1 para. 1 of the Waste Disposal Act but from sec. 9 a para. 1 Atomic Energy Act. (WG) [de

  1. Influence of ocular perfusion pressure fluctuation on glaucoma

    Directory of Open Access Journals (Sweden)

    Min-Zi Ren

    2015-12-01

    Full Text Available AIM:To investigate the influence of ocular perfusion pressure fluctuation on glaucoma. METHODS:Forty patients with primary open angle glaucoma from January 2013 to June 2015 in our hospital were used as observation group and 40 families were used as control group. Circadian fluctuation of intraocular pressure, blood pressure and ocular perfusion pressure in 24h were determined to obtain systolic ocular perfusion pressure(SOPP, diastolic ocular perfusion pressure(DOPPand mean ocular perfusion pressure(MOPP. Pearson linear correlation was used to analyze the correlation of circadian MOPP fluctuation with cup-disc ratio, mean defect(MDand the picture standard deviation(PSD. RESULTS:The fluctuation of MOPP, SOPP and DOPP of observation group were significantly higher than those of control group(Pr=-0.389, 95%CI:-0.612~-0.082; P=0.011, was positively correlated with PSD(r=0.512, 95%CI:0.139 ~0.782; P=0.008; no correlation was found between it and the vertical cup-disc ratio(r=0.115, 95%CI:0.056~0.369; P=0.355. CONCLUSION:Ocular perfusion pressure fluctuations in patients with primary open angle glaucoma may reflect the severity of the disease and may make the situation aggravating. Therefore through perfusion pressure monitor in 24h may help us understand the ocular blood flow and the development of primary open-angle glaucoma.

  2. Presence of Cytotoxic Extracellular Histones in Machine Perfusate of Donation After Circulatory Death Kidneys.

    Science.gov (United States)

    van Smaalen, Tim C; Beurskens, Daniëlle M H; Hoogland, E R Pieter; Winkens, Bjorn; Christiaans, Maarten H L; Reutelingsperger, Chris P; van Heurn, L W Ernest; Nicolaes, Gerry A F

    2017-04-01

    Extracellular histones are cytotoxic molecules that are related to cell stress and death. They have been shown to play a crucial role in multiple pathophysiologic processes like sepsis, inflammation, vascular dysfunction, and thrombosis. Their role in organ donation and graft function and survival is still unknown. The aim of this study was to assess whether an association exists between the presence of extracellular histones in machine perfusates and deceased donor kidney viability. Machine perfusates of 390 donations after circulatory death kidneys were analyzed for histone concentration, and corresponding graft function and survival were assessed. Extracellular histone concentrations were significantly higher in perfusates of kidneys with posttransplant graft dysfunction (primary nonfunction and delayed graft function) and were an independent risk factor for delayed graft function (odds ratio, 2.152; 95% confidence interval [95% CI], 1.199-3.863) and 1 year graft failure (hazard ratio, 1.386; 95% CI, 1.037-1.853), but not for primary nonfunction (odds ratio, 1.342; 95% CI, 0.900-2.002). One year graft survival was 12% higher in the group with low histone concentrations (P = 0.008) as compared with the group that contained higher histone concentrations. This study warrants future studies to probe for a possible role of cytotoxic extracellular histones in organ viability and suggests that quantitation of extracellular histones might contribute to assessment of posttransplant graft function and survival.

  3. Gammagraphy of cerebral perfusion

    International Nuclear Information System (INIS)

    Vazquez, Silvia

    2003-01-01

    Important aspects of the gammagraphy of cerebral perfusion and the diverse clinical applications in the neurological diseases are comment in this article. We focus in the usefulness of the photon emission cerebral tomography (SPECT) and its capacity to cross the hemato encephalic barrier through the use of radiopharmacons like 99 mTc-H M-PAO and 99mTc-EDC, thus managing to offer functional data on the captantes neurons of the radiopharmacon. The clinical applications of SPECT are studied; cerebrovascular disease, transient ischemic attacks, dementias, Alzheimer disease, as well as other neurological diseases are referred. (The author)

  4. Ventilation-perfusion distribution in normal subjects.

    Science.gov (United States)

    Beck, Kenneth C; Johnson, Bruce D; Olson, Thomas P; Wilson, Theodore A

    2012-09-01

    Functional values of LogSD of the ventilation distribution (σ(V)) have been reported previously, but functional values of LogSD of the perfusion distribution (σ(q)) and the coefficient of correlation between ventilation and perfusion (ρ) have not been measured in humans. Here, we report values for σ(V), σ(q), and ρ obtained from wash-in data for three gases, helium and two soluble gases, acetylene and dimethyl ether. Normal subjects inspired gas containing the test gases, and the concentrations of the gases at end-expiration during the first 10 breaths were measured with the subjects at rest and at increasing levels of exercise. The regional distribution of ventilation and perfusion was described by a bivariate log-normal distribution with parameters σ(V), σ(q), and ρ, and these parameters were evaluated by matching the values of expired gas concentrations calculated for this distribution to the measured values. Values of cardiac output and LogSD ventilation/perfusion (Va/Q) were obtained. At rest, σ(q) is high (1.08 ± 0.12). With the onset of ventilation, σ(q) decreases to 0.85 ± 0.09 but remains higher than σ(V) (0.43 ± 0.09) at all exercise levels. Rho increases to 0.87 ± 0.07, and the value of LogSD Va/Q for light and moderate exercise is primarily the result of the difference between the magnitudes of σ(q) and σ(V). With known values for the parameters, the bivariate distribution describes the comprehensive distribution of ventilation and perfusion that underlies the distribution of the Va/Q ratio.

  5. A recapitulative three-dimensional model of breast carcinoma requires perfusion for multi-week growth

    Directory of Open Access Journals (Sweden)

    Kayla F Goliwas

    2016-07-01

    Full Text Available Breast carcinomas are complex, three-dimensional tissues composed of cancer epithelial cells and stromal components, including fibroblasts and extracellular matrix. In vitro models that more faithfully recapitulate this dimensionality and stromal microenvironment should more accurately elucidate the processes driving carcinogenesis, tumor progression, and therapeutic response. Herein, novel in vitro breast carcinoma surrogates, distinguished by a relevant dimensionality and stromal microenvironment, are described and characterized. A perfusion bioreactor system was used to deliver medium to surrogates containing engineered microchannels and the effects of perfusion, medium composition, and the method of cell incorporation and density of initial cell seeding on the growth and morphology of surrogates were assessed. Perfused surrogates demonstrated significantly greater cell density and proliferation and were more histologically recapitulative of human breast carcinoma than surrogates maintained without perfusion. Although other parameters of the surrogate system, such as medium composition and cell seeding density, affected cell growth, perfusion was the most influential parameter.

  6. Myocardial perfusion SPECT imaging in patients with myocardial bridging

    International Nuclear Information System (INIS)

    Fang Wei; Qiu Hong; Yang Weixian; Wang Feng; He Zuoxiang

    2008-01-01

    Objective: Stress myocardial perfusion SPECT imaging was used to assess myocardial ischemia in patients with myocardial bridging. Methods: Ninety-six patients with myocardial bridging of the left anterior descending artery documented by coronary angiography were included in this study. All under- went exercise or pharmacological stress myocardial perfusion SPECT assessing myocardial ischemia. None had prior myocardial infarction. One year follow-up by telephone interview was performed in all patients. Results The mean stenotic severity of systolic phase on angiography was (65 ± 19)%. In the SPECT study, 20 of 96 (20.8%) patients showed abnormal perfusion. This percentage was significantly higher than that of stress electrocardiogram (ECG). The higher positive rate of SPECT perfusion images was showed in the group of patients with severe systolic narrowing (≥75%) than that with mild-to-moderate systolic narrowing (50% vs 6.3%, P<0.001). The prevalence of abnormal image was significantly higher in ELDERLY PEOPLE; patients with STT change on rest ECG than in those with normal rest ECG (54.2% vs 9.7%, P<0.001). During follow-up, one patient with abnormal SPECT perfusion image sustained angina and accepted percutaneous coronary intervention, and no cardiac event occurred in patients with normal images. Conclusions: Stress myocardial perfusion SPECT imaging can be used effectively for assessing myocardial ischemia and has potential prognostic value for patients with myocardial bridging. (authors)

  7. Tumor Vessel Compression Hinders Perfusion of Ultrasonographic Contrast Agents

    Directory of Open Access Journals (Sweden)

    Mirco Galiè

    2005-05-01

    Full Text Available Contrast-enhanced ultrasound (CEUS is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 μm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI. Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes.

  8. Tumor Vessel Compression Hinders Perfusion of Ultrasonographic Contrast Agents1

    Science.gov (United States)

    Galiè, Mirco; D'Onofrio, Mirko; Montani, Maura; Amici, Augusto; Calderan, Laura; Marzola, Pasquina; Benati, Donatella; Merigo, Flavia; Marchini, Cristina; Sbarbati, Andrea

    2005-01-01

    Abstract Contrast-enhanced ultrasound (CEUS) is an advanced approach to in vivo assessment of tumor vascularity and is being increasingly adopted in clinical oncology. It is based on 1- to 10 µm-sized gas microbubbles, which can cross the capillary beds of the lungs and are effective echo enhancers. It is known that high cell density, high transendothelial fluid exchange, and poorly functioning lymphatic circulation all provoke solid stress, which compresses vessels and drastically reduces tumor blood flow. Given their size, we supposed that the perfusion of microbubbles is affected by anatomic features of tumor vessels more than are contrast agents traditionally used in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Here, we compared dynamic information obtained from CEUS and DCE-MRI on two experimental tumor models exhibiting notable differences in vessel anatomy. We found that tumors with small, flattened vessels show a much higher resistance to microbubble perfusion than to MRI contrast agents, and appear scarcely vascularized at CEUS examination, despite vessel volume adequate for normal function. Thus, whereas CEUS alone could induce incorrect diagnosis when tumors have small or collapsed vessels, integrated analysis using CEUS and DCE-MRI allows in vivo identification of tumors with a vascular profile frequently associated with malignant phenotypes. PMID:15967105

  9. Effects of a perfusion bioreactor activated novel bone substitute in spine fusion in sheep

    DEFF Research Database (Denmark)

    Sørensen, Jesper Roed; Koroma, Kariatta Ester; Ding, Ming

    2012-01-01

    To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model.......To evaluate the effect of a large perfusion-bioreactor cell-activated bone substitute, on a two-level large posterolateral spine fusion sheep model....

  10. Role of perfusion SPECT in prediction and measurement of pulmonary complications after radiotherapy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Farr, Katherina P.; Khalil, Azza A.; Grau, Cai [Aarhus University Hospital, Department of Oncology, Aarhus C (Denmark); Kramer, Stine; Morsing, Anni [Aarhus University Hospital, Department of Nuclear Medicine and PET Centre, Aarhus C (Denmark)

    2015-07-15

    The purpose of the study was to evaluate the ability of baseline perfusion defect score (DS) on SPECT to predict the development of severe symptomatic radiation pneumonitis (RP) and to evaluate changes in perfusion on SPECT as a method of lung perfusion function assessment after curative radiotherapy (RT) for non-small-cell lung cancer (NSCLC). Patients with NSCLC undergoing curative RT were included prospectively. Perfusion SPECT/CT and global pulmonary function tests (PFT) were performed before RT and four times during follow-up. Functional activity on SPECT was measured using a semiquantitative perfusion DS. Pulmonary morbidity was graded by the National Cancer Institute's Common Terminology Criteria for Adverse Events version 4 for pneumonitis. Patients were divided into two groups according to the severity of RP. A total of 71 consecutive patients were included in the study. Baseline DS was associated with chronic obstructive pulmonary disease. A significant inverse correlation was found between baseline DS and forced expiratory volume in 1 s and diffusing capacity of the lung for carbon monoxide. Patients with severe RP had significantly higher baseline total lung DS (mean 5.43) than those with no or mild symptoms (mean DS 3.96, p < 0.01). PFT results were not different between these two groups. The odds ratio for total lung DS was 7.8 (95 % CI 1.9 - 31) demonstrating the ability of this parameter to predict severe RP. Adjustment for other potential confounders known to be associated with increased risk of RP was performed and did not change the odds ratio. The median follow-up time after RT was 8.4 months. The largest DS increase of 13.3 % was associated with severe RP at 3 months of follow-up (p < 0.01). The development of severe RP during follow-up was not associated with changes in PFT results. Perfusion SPECT is a valuable method for predicting severe RP and for assessing changes in regional functional perfusion after curative RT comparable with

  11. Patient satisfaction with coronary CT angiography, myocardial CT perfusion, myocardial perfusion MRI, SPECT myocardial perfusion imaging and conventional coronary angiography

    Energy Technology Data Exchange (ETDEWEB)

    Feger, S.; Rief, M.; Zimmermann, E.; Richter, F.; Roehle, R. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Dewey, M. [Freie Universitaet Berlin, Department of Radiology, Charite - Universitaetsmedizin Berlin Campus Mitte, Humboldt-Universitaet zu Berlin, Berlin (Germany); Institut fuer Radiologie, Berlin (Germany); Schoenenberger, E. [Medizinische Hochschule Hannover, Department of Medicine, Hannover (Germany)

    2015-07-15

    To evaluate patient acceptance of noninvasive imaging tests for detection of coronary artery disease (CAD), including single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), stress perfusion magnetic resonance imaging (MRI), coronary CT angiography (CTA) in combination with CT myocardial stress perfusion (CTP), and conventional coronary angiography (CCA). Intraindividual comparison of perception of 48 patients from the CORE320 multicentre multinational study who underwent rest and stress SPECT-MPI with a technetium-based tracer, combined CTA and CTP (both with contrast agent, CTP with adenosine), MRI, and CCA. The analysis was performed by using a validated questionnaire. Patients had significantly more concern prior to CCA than before CTA/CTP (p < 0.001). CTA/CTP was also rated as more comfortable than SPECT-MPI (p = 0.001). Overall satisfaction with CT was superior to that of MRI (p = 0.007). More patients preferred CT (46 %; p < 0.001) as a future diagnostic test. Regarding combined CTA/CTP, CTP was characterised by higher pain levels and an increased frequency of angina pectoris during the examination (p < 0.001). Subgroup analysis showed a higher degree of pain during SPECT-MPI with adenosine stress compared to physical exercise (p = 0.016). All noninvasive cardiac imaging tests are well accepted by patients, with CT being the preferred examination. (orig.)

  12. A 3D printed microfluidic perfusion device for multicellular spheroid cultures.

    Science.gov (United States)

    Ong, Louis Jun Ye; Islam, Anik; DasGupta, Ramanuj; Iyer, Narayanan Gopalakkrishna; Leo, Hwa Liang; Toh, Yi-Chin

    2017-09-11

    The advent of 3D printing technologies promises to make microfluidic organ-on-chip technologies more accessible for the biological research community. To date, hydrogel-encapsulated cells have been successfully incorporated into 3D printed microfluidic devices. However, there is currently no 3D printed microfluidic device that can support multicellular spheroid culture, which facilitates extensive cell-cell contacts important for recapitulating many multicellular functional biological structures. Here, we report a first instance of fabricating a 3D printed microfluidic cell culture device capable of directly immobilizing and maintaining the viability and functionality of 3D multicellular spheroids. We evaluated the feasibility of two common 3D printing technologies i.e. stereolithography (SLA) and PolyJet printing, and found that SLA could prototype a device comprising of cell immobilizing micro-structures that were housed within a microfluidic network with higher fidelity. We have also implemented a pump-free perfusion system, relying on gravity-driven flow to perform medium perfusion in order to reduce the complexity and footprint of the device setup, thereby improving its adaptability into a standard biological laboratory. Finally, we demonstrated the biological performance of the 3D printed device by performing pump-free perfusion cultures of patient-derived parental and metastatic oral squamous cell carcinoma tumor and liver cell (HepG2) spheroids with good cell viability and functionality. This paper presents a proof-of-concept in simplifying and integrating the prototyping and operation of a microfluidic spheroid culture device, which will facilitate its applications in various drug efficacy, metabolism and toxicity studies.

  13. The Use of an Acellular Oxygen Carrier in a Human Liver Model of Normothermic Machine Perfusion.

    Science.gov (United States)

    Laing, Richard W; Bhogal, Ricky H; Wallace, Lorraine; Boteon, Yuri; Neil, Desley A H; Smith, Amanda; Stephenson, Barney T F; Schlegel, Andrea; Hübscher, Stefan G; Mirza, Darius F; Afford, Simon C; Mergental, Hynek

    2017-11-01

    Normothermic machine perfusion of the liver (NMP-L) is a novel technique that preserves liver grafts under near-physiological conditions while maintaining their normal metabolic activity. This process requires an adequate oxygen supply, typically delivered by packed red blood cells (RBC). We present the first experience using an acellular hemoglobin-based oxygen carrier (HBOC) Hemopure in a human model of NMP-L. Five discarded high-risk human livers were perfused with HBOC-based perfusion fluid and matched to 5 RBC-perfused livers. Perfusion parameters, oxygen extraction, metabolic activity, and histological features were compared during 6 hours of NMP-L. The cytotoxicity of Hemopure was also tested on human hepatic primary cell line cultures using an in vitro model of ischemia reperfusion injury. The vascular flow parameters and the perfusate lactate clearance were similar in both groups. The HBOC-perfused livers extracted more oxygen than those perfused with RBCs (O2 extraction ratio 13.75 vs 9.43 % ×10 per gram of tissue, P = 0.001). In vitro exposure to Hemopure did not alter intracellular levels of reactive oxygen species, and there was no increase in apoptosis or necrosis observed in any of the tested cell lines. Histological findings were comparable between groups. There was no evidence of histological damage caused by Hemopure. Hemopure can be used as an alternative oxygen carrier to packed red cells in NMP-L perfusion fluid.

  14. In-vivo quantitative evaluation of perfusion zones and perfusion gradient in the deep inferior epigastric artery perforator flap

    Science.gov (United States)

    Saint-Cyr, Michel; Lakhiani, Chrisovalantis; Cheng, Angela; Mangum, Michael; Liang, Jinyang; Teotia, Sumeet; Livingston, Edward H.; Zuzak, Karel J.

    2013-03-01

    The selection of well-vascularized tissue during DIEP flap harvest remains controversial. While several studies have elucidated cross-midline perfusion, further characterization of perfusion to the ipsilateral hemiabdomen is necessary for minimizing rates of fat necrosis or partial fat necrosis in bilateral DIEP flaps. Eighteen patients (29 flaps) underwent DIEP flap harvest using a prospectively designed protocol. Perforators were marked and imaged with a novel system for quantitatively measuring tissue oxygenation, the Digital Light Hyperspectral Imager. Images were then analyzed to determine if perforator selection influenced ipsilateral flap perfusion. Flaps based on a single lateral row perforator (SLRP) were found to have a higher level of hemoglobin oxygenation in Zone I (mean %HbO2 = 76.1) compared to single medial row perforator (SMRP) flaps (%HbO2 = 71.6). Perfusion of Zone III relative to Zone I was similar between SLRP and SMRP flaps (97.4% vs. 97.9%, respectively). These differences were not statistically significant (p>0.05). Perfusion to the lateral edge of the flap was slightly greater for SLRP flaps compared SMRP flaps (92.1% vs. 89.5%, respectively). SMRP flaps had superior perfusion travelling inferiorly compared to SLRP flaps (88.8% vs. 83.9%, respectively). Overall, it was observed that flaps were better perfused in the lateral direction than inferiorly. Significant differences in perfusion gradients directed inferiorly or laterally were observed, and perforator selection influenced perfusion in the most distal or inferior aspects of the flap. This suggests broader clinical implications for flap design that merit further investigation.

  15. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Y.; Hayashida, K.; Uehara, T.; Shimonagata, T.; Nishimura, T.; Osaka Univ., Suita

    1993-01-01

    15 cases of primary pulmonary hypertension were classified into two groups by patterns of perfusion lung scintigraphy. Perfusion scintigrams showed multiple, small, ill-defined defects (mottled + ve) pattern in eight cases, and the remaining seven cases had a normal (mottled - ve) pattern. The mean pulmonary arterial pressure in patients with a mottled pattern (54 ± 10 mmHg) was higher than in those with a normal pattern (42 ± 9 mmHg, p < 0.05). There were no significant differences between the two groups in right ventricular ejection fraction, partial pressures of oxygen in the arterial blood or alveolo-arterial oxygen difference. All the patients with a mottled pattern died within 2 years following the lung scintigraphy. There was a significant difference in the survival curves between the two groups. (author)

  16. Brain perfusion: computed tomography applications

    International Nuclear Information System (INIS)

    Miles, K.A.

    2004-01-01

    Within recent years, the broad introduction of fast multi-detector computed tomography (CT) systems and the availability of commercial software for perfusion analysis have made cerebral perfusion imaging with CT a practical technique for the clinical environment. The technique is widely available at low cost, accurate and easy to perform. Perfusion CT is particularly applicable to those clinical circumstances where patients already undergo CT for other reasons, including stroke, head injury, subarachnoid haemorrhage and radiotherapy planning. Future technical developments in multi-slice CT systems may diminish the current limitations of limited spatial coverage and radiation burden. CT perfusion imaging on combined PET-CT systems offers new opportunities to improve the evaluation of patients with cerebral ischaemia or tumours by demonstrating the relationship between cerebral blood flow and metabolism. Yet CT is often not perceived as a technique for imaging cerebral perfusion. This article reviews the use of CT for imaging cerebral perfusion, highlighting its advantages and disadvantages and draws comparisons between perfusion CT and magnetic resonance imaging. (orig.)

  17. Perfusion CT in acute stroke

    International Nuclear Information System (INIS)

    Eckert, Bernd; Roether, Joachim; Fiehler, Jens; Thomalla, Goetz

    2015-01-01

    Modern multislice CT scanners enable multimodal protocols including non-enhanced CT, CT angiography, and CT perfusion. A 64-slice CT scanner provides 4-cm coverage. To cover the whole brain, a 128 - 256-slice scanner is needed. The use of perfusion CT requires an optimized scan protocol in order to reduce exposure to radiation. As compared to non-enhanced CT and CT angiography, the use of CT perfusion increases detection rates of cerebral ischemia, especially small cortical ischemic lesions, while the detection of lacunar and infratentorial stroke lesions remains limited. Perfusion CT enables estimation of collateral flow in acute occlusion of large intra- or extracranial arteries. Currently, no established reliable thresholds are available for determining infarct core and penumbral tissue by CT perfusion. Moreover, perfusion parameters depend on the processing algorithms and the software used for calculation. However, a number of studies point towards a reduction of cerebral blood volume (CBV) below 2 ml/100 g as a critical threshold that identifies infarct core. Large CBV lesions are associated with poor outcome even in the context of recanalization. The extent of early ischemic signs on non-enhanced CT remains the main parameter from CT imaging to guide acute reperfusion treatment. Nevertheless, perfusion CT increases diagnostic and therapeutic certainty in the acute setting. Similar to stroke MRI, perfusion CT enables the identification of tissue at risk of infarction by the mismatch between infarct core and the larger area of critical hypoperfusion. Further insights into the validity of perfusion parameters are expected from ongoing trials of mechanical thrombectomy in stroke.

  18. Placental perfusion - a human alternative

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E

    2006-01-01

    Foetal exposures to environmental and medicinal products have impact on the growth of the foetus (e.g. cigarette smoke) and development of organs (e.g. methylmercury and Thalidomide). Perfusion studies of the human term placenta enable investigation of placental transport of chemical substances...... between the mother and foetus. Dual perfusion of a single cotyledon in the human placenta can contribute to a better understanding of the placental barrier, transport rate and mechanisms of different substances and placental metabolism. The perfusion system has recently been established in Copenhagen...

  19. Static compression down-regulates N-cadherin expression and facilitates loss of cell phenotype of nucleus pulposus cells in a disc perfusion culture.

    Science.gov (United States)

    Zhou, Haibo; Shi, Jianmin; Zhang, Chao; Li, Pei

    2018-02-28

    Mechanical compression often induces degenerative changes of disc nucleus pulposus (NP) tissue. It has been indicated that N-cadherin (N-CDH)-mediated signaling helps to preserve the NP cell phenotype. However, N-CDH expression and the resulting NP-specific phenotype alteration under the static compression and dynamic compression remain unclear. To study the effects of static compression and dynamic compression on N-CDH expression and NP-specific phenotype in an in vitro disc organ culture. Porcine discs were organ cultured in a self-developed mechanically active bioreactor for 7 days and subjected to static or dynamic compression (0.4 MPa for 2 h once per day). The noncompressed discs were used as controls. Compared with the dynamic compression, static compression significantly down-regulated the expression of N-CDH and NP-specific markers (laminin, brachyury, and keratin 19); decreased the Alcian Blue staining intensity, glycosaminoglycan and hydroxyproline contents; and declined the matrix macromolecule (aggrecan and collagen II) expression. Compared with the dynamic compression, static compression causes N-CDH down-regulation, loss of NP-specific phenotype, and the resulting decrease in NP matrix synthesis. © 2018 The Author(s).

  20. Nuclear magnetic resonance of perfused tissue

    International Nuclear Information System (INIS)

    Harpen, M.D.; Allison, R.C.

    1986-01-01

    The effect of perfusion on the NMR signal observed in NMR imaging is studied in a phantom and in two isolated perfused canine lungs. It is observed that perfusion in tissue has little effect on longitudinal relaxation times. Transverse relaxation rates are observed to correlate linearly with rates of perfusion, in accordance with a model presented. (author)

  1. Quantitative lung perfusion evaluation using Fourier decomposition perfusion MRI.

    Science.gov (United States)

    Kjørstad, Åsmund; Corteville, Dominique M R; Fischer, Andre; Henzler, Thomas; Schmid-Bindert, Gerald; Zöllner, Frank G; Schad, Lothar R

    2014-08-01

    To quantitatively evaluate lung perfusion using Fourier decomposition perfusion MRI. The Fourier decomposition (FD) method is a noninvasive method for assessing ventilation- and perfusion-related information in the lungs, where the perfusion maps in particular have shown promise for clinical use. However, the perfusion maps are nonquantitative and dimensionless, making follow-ups and direct comparisons between patients difficult. We present an approach to obtain physically meaningful and quantifiable perfusion maps using the FD method. The standard FD perfusion images are quantified by comparing the partially blood-filled pixels in the lung parenchyma with the fully blood-filled pixels in the aorta. The percentage of blood in a pixel is then combined with the temporal information, yielding quantitative blood flow values. The values of 10 healthy volunteers are compared with SEEPAGE measurements which have shown high consistency with dynamic contrast enhanced-MRI. All pulmonary blood flow (PBF) values are within the expected range. The two methods are in good agreement (mean difference = 0.2 mL/min/100 mL, mean absolute difference = 11 mL/min/100 mL, mean PBF-FD = 150 mL/min/100 mL, mean PBF-SEEPAGE = 151 mL/min/100 mL). The Bland-Altman plot shows a good spread of values, indicating no systematic bias between the methods. Quantitative lung perfusion can be obtained using the Fourier Decomposition method combined with a small amount of postprocessing. Copyright © 2013 Wiley Periodicals, Inc.

  2. CT Perfusion Characteristics Identify Metastatic Sites in Liver

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2015-01-01

    Full Text Available Tissue perfusion plays a critical role in oncology because growth and migration of cancerous cells require proliferation of new blood vessels through the process of tumor angiogenesis. Computed tomography (CT perfusion is an emerging functional imaging modality that measures tissue perfusion through dynamic CT scanning following intravenous administration of contrast medium. This noninvasive technique provides a quantitative basis for assessing tumor angiogenesis. CT perfusion has been utilized on a variety of organs including lung, prostate, liver, and brain, with promising results in cancer diagnosis, disease prognostication, prediction, and treatment monitoring. In this paper, we focus on assessing the extent to which CT perfusion characteristics can be used to discriminate liver metastases from neuroendocrine tumors from normal liver tissues. The neuroendocrine liver metastases were analyzed by distributed parameter modeling to yield tissue blood flow (BF, blood volume (BV, mean transit time (MTT, permeability (PS, and hepatic arterial fraction (HAF, for tumor and normal liver. The result reveals the potential of CT perfusion as a tool for constructing biomarkers from features of the hepatic vasculature for guiding cancer detection, prognostication, and treatment selection.

  3. Phosphorus NMR of isolated perfused morris hepatomas

    International Nuclear Information System (INIS)

    Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.

    1986-01-01

    The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin

  4. Hepatic perfusion during hepatic artery infusion chemotherapy: Evaluation with perfusion CT and perfusion scintigraphy

    International Nuclear Information System (INIS)

    Miller, D.L.; Carrasquillo, J.A.; Lutz, R.J.; Chang, A.E.

    1989-01-01

    The standard method for the evaluation of hepatic perfusion during hepatic artery infusion (HAI) chemotherapy is planar hepatic artery perfusion scintigraphy (HAPS). Planar HAPS was performed with 2 mCi of [99mTc] macroaggregated albumin infused at 1 ml/min and compared with single photon emission CT (SPECT) HAPS and with a new study, CT performed during the slow injection of contrast material through the HAI catheter (HAI-CT). Thirteen patients underwent 16 HAI-CT studies, 14 planar HAPS studies, and 9 SPECT HAPS studies. In 13 of 14 studies (93%) HAI-CT and planar HAPS were in complete agreement as to the perfusion pattern of intrahepatic metastases and normal liver. In nine studies where all modalities were performed, the findings identified by HAI-CT and planar HAPS agreed in all cases, whereas the results of two SPECT scans disagreed with the other studies. With respect to perfusion of individual metastases, 14 of 14 HAI-CT studies, 12 of 13 planar HAPS studies, and 9 of 9 SPECT HAPS studies correctly demonstrated the perfusion status of individual lesions as indicated by the pattern of changes in tumor size determined on CT obtained before and after the perfusion studies. Hepatic artery infusion CT was superior for delineation of individual metastases, particularly small lesions, and for the evaluation of nonperfused portions of the liver. Planar HAPS detected extrahepatic perfusion in four patients, and this was not detected by HAI-CT. We conclude that HAI-CT and scintigraphy are complementary techniques. Hepatic artery infusion CT has advantages for the evaluation of intrahepatic perfusion, and planar HAPS is superior to HAI-CT for the detection of extrahepatic perfusion

  5. The advantage of high relaxivity contrast agents in brain perfusion

    International Nuclear Information System (INIS)

    Cotton, F.; Hermier, M.

    2006-01-01

    Accurate MRI characterization of brain lesions is critical for planning therapeutic strategy, assessing prognosis and monitoring response to therapy. Conventional MRI with gadolinium-based contrast agents is useful for the evaluation of brain lesions, but this approach primarily depicts areas of disruption of the blood-brain barrier (BBB) rather than tissue perfusion. Advanced MR imaging techniques such as dynamic contrast agent-enhanced perfusion MRI provide physiological information that complements the anatomic data available from conventional MRI. We evaluated brain perfusion imaging with gadobenate dimeglumine (Gd-BOPTA, MultiHance; Bracco Imaging, Milan, Italy). The contrast-enhanced perfusion technique was performed on a Philips Intera 1.5-T MR system. The technique used to obtain perfusion images was dynamic susceptibility contrast-enhanced MRI, which is highly sensitive to T2* changes. Combined with PRESTO perfusion imaging, SENSE is applied to double the temporal resolution, thereby improving the signal intensity curve fit and, accordingly, the accuracy of the derived parametric images. MultiHance is the first gadolinium MR contrast agent with significantly higher T1 and T2 relaxivities than conventional MR contrast agents. The higher T1 relaxivity, and therefore better contrast-enhanced T1-weighted imaging, leads to significantly improved detection of BBB breakdown and hence improved brain tumor conspicuity and delineation. The higher T2 relaxivity allows high-quality T2*-weighted perfusion MRI and the derivation of good quality relative cerebral blood volume (rCBV) maps. We determined the value of MultiHance for enhanced T2*-weighted perfusion imaging of histologically proven (by surgery or stereotaxic biopsy) intraaxial brain tumors (n=80), multiple sclerosis lesions (n=10), abscesses (n=4), neurolupus (n=15) and stroke (n=16). All the procedures carried out were safe and no adverse events occurred. The acquired perfusion images were of good quality in

  6. Myocardial perfusion imaging in hyperthrophic cardiomyopathy

    International Nuclear Information System (INIS)

    Moorin, B.

    1998-01-01

    Full text: Patients with Hyperthrophic Cardiomyopathy (HCM) frequently suffer from syncope and cardiac arrest which may lead to sudden death. This is most often caused by ventricular arrhythmia's in adults, however in young patients the mechanisms are thought to be different. Ischaemia may play a significant role even in young asymptomatic HCM patients. The mechanisms of ischaemic development in HCM differ from those in the 'normal' myocardium (Due to intramural small vessel abnormalities and abnormal myocellular architecture). In HCM the coronary microcirculation is most often affected and massive hypertrophy means more energy is required to promote contraction thus increasing oxygen demand and compounding the effects of any ischaemic changes. A case of a 12 year old HCM patient is presented who has symptoms of syncope associated with exercise whose mother died suddenly of cardiac arrest developed from HCM. A myocardial perfusion rest/stress study was undertaken to detect any underlying myocardial ischaemia. Myocardial perfusion scintigraphy demonstrates any reduction in the microcirculation in addition to that present in the macrocirculation, unlike angiography which will only detect the latter. In this case the scan clearly showed evidence of ischaemia in the lateral wall and this may be an explanation for her episodes of syncope. We suggest an algorithm or the routine work-up of young patients with HCM which makes aggressive use of myocardial perfusion imaging to detect ischaemic changes. This may identify patients who are at higher risk and will assist with treatment decisions. We feel myocardial perfusion scintigraphy is a sensitive non-invasive accurate method of detecting microcirculatory ischaemia and is thus invaluable in HCM patients

  7. SHARP: A Spatially Higher-order, Relativistic Particle-in-cell Code

    Energy Technology Data Exchange (ETDEWEB)

    Shalaby, Mohamad; Broderick, Avery E. [Department of Physics and Astronomy, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1 (Canada); Chang, Philip [Department of Physics, University of Wisconsin-Milwaukee, 1900 E. Kenwood Boulevard, Milwaukee, WI 53211 (United States); Pfrommer, Christoph [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Lamberts, Astrid [Theoretical Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Puchwein, Ewald, E-mail: mshalaby@live.ca [Institute of Astronomy and Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom)

    2017-05-20

    Numerical heating in particle-in-cell (PIC) codes currently precludes the accurate simulation of cold, relativistic plasma over long periods, severely limiting their applications in astrophysical environments. We present a spatially higher-order accurate relativistic PIC algorithm in one spatial dimension, which conserves charge and momentum exactly. We utilize the smoothness implied by the usage of higher-order interpolation functions to achieve a spatially higher-order accurate algorithm (up to the fifth order). We validate our algorithm against several test problems—thermal stability of stationary plasma, stability of linear plasma waves, and two-stream instability in the relativistic and non-relativistic regimes. Comparing our simulations to exact solutions of the dispersion relations, we demonstrate that SHARP can quantitatively reproduce important kinetic features of the linear regime. Our simulations have a superior ability to control energy non-conservation and avoid numerical heating in comparison to common second-order schemes. We provide a natural definition for convergence of a general PIC algorithm: the complement of physical modes captured by the simulation, i.e., those that lie above the Poisson noise, must grow commensurately with the resolution. This implies that it is necessary to simultaneously increase the number of particles per cell and decrease the cell size. We demonstrate that traditional ways for testing for convergence fail, leading to plateauing of the energy error. This new PIC code enables us to faithfully study the long-term evolution of plasma problems that require absolute control of the energy and momentum conservation.

  8. Hydrostatic determinants of cerebral perfusion

    International Nuclear Information System (INIS)

    Wagner, E.M.; Traystman, R.J.

    1986-01-01

    We examined the cerebral blood flow response to alterations in perfusion pressure mediated through decreases in mean arterial pressure, increases in cerebrospinal fluid (CSF) pressure, and increases in jugular venous (JV) pressure in 42 pentobarbital anesthetized dogs. Each of these three pressures was independently controlled. Cerebral perfusion pressure was defined as mean arterial pressure minus JV or CSF pressure, depending on which was greater. Mean hemispheric blood flow was measured with the radiolabeled microsphere technique. Despite 30-mm Hg reductions in mean arterial pressure or increases in CSF or JV pressure, CBF did not change as long as the perfusion pressure remained greater than approximately 60 mm Hg. However, whenever perfusion pressure was reduced to an average of 48 mm Hg, cerebral blood flow decreased 27% to 33%. These results demonstrate the capacity of the cerebral vascular bed to respond similarly to changes in the perfusion pressure gradient obtained by decreasing mean arterial pressure, increasing JV pressure or increasing CSF pressure, and thereby support the above definition of cerebral perfusion pressure

  9. Ecotoxicological assessment of solar cell leachates: Copper indium gallium selenide (CIGS) cells show higher activity than organic photovoltaic (OPV) cells.

    Science.gov (United States)

    Brun, Nadja Rebecca; Wehrli, Bernhard; Fent, Karl

    2016-02-01

    Despite the increasing use of photovoltaics their potential environmental risks are poorly understood. Here, we compared ecotoxicological effects of two thin-film photovoltaics: established copper indium gallium selenide (CIGS) and organic photovoltaic (OPV) cells. Leachates were produced by exposing photovoltaics to UV light, physical damage, and exposure to environmentally relevant model waters, representing mesotrophic lake water, acidic rain, and seawater. CIGS cell leachates contained 583 μg L(-1) molybdenum at lake water, whereas at acidic rain and seawater conditions, iron, copper, zinc, molybdenum, cadmium, silver, and tin were present up to 7219 μg L(-1). From OPV, copper (14 μg L(-1)), zinc (87 μg L(-1)) and silver (78 μg L(-1)) leached. Zebrafish embryos were exposed until 120 h post-fertilization to these extracts. CIGS leachates produced under acidic rain, as well as CIGS and OPV leachates produced under seawater conditions resulted in a marked hatching delay and increase in heart edema. Depending on model water and solar cell, transcriptional alterations occurred in genes involved in oxidative stress (cat), hormonal activity (vtg1, ar), metallothionein (mt2), ER stress (bip, chop), and apoptosis (casp9). The effects were dependent on the concentrations of cationic metals in leachates. Addition of ethylenediaminetetraacetic acid protected zebrafish embryos from morphological and molecular effects. Our study suggests that metals leaching from damaged CIGS cells, may pose a potential environmental risk. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma.

    Science.gov (United States)

    Ho, Chang Y; Gener, Melissa; Bonnin, Jose; Kralik, Stephen F

    2016-07-01

    We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.

  11. Increased circulating fibrocytes are associated with higher reticulocyte percent in children with sickle cell anemia.

    Science.gov (United States)

    Karafin, Matthew S; Dogra, Shibani; Rodeghier, Mark; Burdick, Marie; Mehrad, Borna; Rose, C Edward; Strieter, Robert M; DeBaun, Michael R; Strunk, Robert C; Field, Joshua J

    2016-03-01

    Interstitial lung disease is common in patients with sickle cell anemia (SCA). Fibrocytes are circulating cells implicated in the pathogenesis of pulmonary fibrosis and airway remodeling in asthma. In this study, we tested the hypotheses that fibrocyte levels are: (1) increased in children with SCA compared to healthy controls, and (2) associated with pulmonary disease. Cross-sectional cohort study of children with SCA who participated in the Sleep Asthma Cohort Study. Fibrocyte levels were obtained from 45 children with SCA and 24 controls. Mean age of SCA cases was 14 years and 53% were female. In children with SCA, levels of circulating fibrocytes were greater than controls (P < 0.01). The fibrocytes expressed a hierarchy of chemokine receptors, with CXCR4 expressed on the majority of cells and CCR2 and CCR7 expressed on a smaller subset. Almost half of fibrocytes demonstrated α-smooth muscle actin activation. Increased fibrocyte levels were associated with a higher reticulocyte count (P = 0.03) and older age (P = 0.048) in children with SCA. However, children with increased levels of fibrocytes were not more likely to have asthma or lower percent predicted forced expiratory volume in 1 sec/forced vital capacity (FEV1 /FVC) or FEV1 than those with lower fibrocyte levels. Higher levels of fibrocytes in children with SCA compared to controls may be due to hemolysis. Longitudinal studies may be able to better assess the relationship between fibrocyte level and pulmonary dysfunction. © 2015 Wiley Periodicals, Inc.

  12. Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

    Science.gov (United States)

    Govindarajan, Tina; Shandas, Robin

    2018-01-01

    Shape Memory Polymers (SMPs) are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA) and Poly(ethylene glycol) dimethacrylate (PEGDMA) were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA), contact angle studies, and atomic force microscopy (AFM) were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC) attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices. PMID:29707382

  13. Shape Memory Polymers Containing Higher Acrylate Content Display Increased Endothelial Cell Attachment

    Directory of Open Access Journals (Sweden)

    Tina Govindarajan

    2017-11-01

    Full Text Available Shape Memory Polymers (SMPs are smart materials that can recall their shape upon the application of a stimulus, which makes them appealing materials for a variety of applications, especially in biomedical devices. Most prior SMP research has focused on tuning bulk properties; studying surface effects of SMPs may extend the use of these materials to blood-contacting applications, such as cardiovascular stents, where surfaces that support rapid endothelialization have been correlated to stent success. Here, we evaluate endothelial attachment onto the surfaces of a family of SMPs previously developed in our group that have shown promise for biomedical devices. Nine SMP formulations containing varying amounts of tert-Butyl acrylate (tBA and Poly(ethylene glycol dimethacrylate (PEGDMA were analyzed for endothelial cell attachment. Dynamic mechanical analysis (DMA, contact angle studies, and atomic force microscopy (AFM were used to verify bulk and surface properties of the SMPs. Human umbilical vein endothelial cell (HUVEC attachment and viability was verified using fluorescent methods. Endothelial cells preferentially attached to SMPs with higher tBA content, which have rougher, more hydrophobic surfaces. HUVECs also displayed an increased metabolic activity on these high tBA SMPs over the course of the study. This class of SMPs may be promising candidates for next generation blood-contacting devices.

  14. Radiation response of perfused tracheal sections

    International Nuclear Information System (INIS)

    Ford, J.R.; Maslowski, A.J.; Braby, L.A.

    2003-01-01

    Full text: A model of respiratory tissue using a perfusion culture system is being developed. We are using this system to quantify the effects of normal tissue architecture and the interaction of epithelial cells with other cell types on radiation-induced bystander effects. Tracheal tissue taken from young adult male Fischer 344 rats is imbedded in a growth factor enriched agarose matrix. The chamber is designed to allow growth medium to periodically wash the epithelial surface of the tracheal lumen while maintaining the air-interface that is necessary for the normal differentiation of the epithelium. In preliminary experiments with rat trachea we have shown that a differentiated epithelial lining can be maintained for several days. Cells can be obtained for a number of different cell culture assays for endpoints such as survival and preneoplastic transformation after irradiation

  15. CT Perfusion evaluation of gastric cancer. Correlation with histologic type

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Ho; Joo, Ijin [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Kim, Se Hyung [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Han, Joon Koo [Seoul National University Hospital, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Institute of Radiation Medicine, Seoul (Korea, Republic of)

    2018-02-15

    To prospectively evaluate if the perfusion parameters of gastric cancer can provide information on histologic subtypes of gastric cancer. We performed preoperative perfusion CT (PCT) and curative gastrectomy in 46 patients. PCT data were analysed using a dedicated software program. Perfusion parameters were obtained by two independent radiologists and were compared according to histologic type using Kruskal-Wallis, Mann-Whitney U test and receiver operating characteristic analysis. To assess inter-reader agreement, we used intraclass correlation coefficient (ICC). Inter-reader agreement for perfusion parameters was moderate to substantial (ICC = 0.585-0.678). Permeability surface value of poorly cohesive carcinoma (PCC) was significantly higher than other histologic types (47.3 ml/100 g/min in PCC vs 26.5 ml/100 g/min in non-PCC, P < 0.001). Mean transit time (MTT) of PCC was also significantly longer than non-PCC (13.0 s in PCC vs 10.3 s in non-PCC, P = 0.032). The area under the curve to predict PCC was 0.891 (P < 0.001) for permeability surface and 0.697 (P = 0.015) for MTT. Obtaining perfusion parameters from PCT was feasible in gastric cancer patients and can aid in the preoperative imaging diagnosis of PCC-type gastric cancer as the permeability surface and MTT value of PCC type gastric cancer were significantly higher than those of non-PCC. (orig.)

  16. CT Perfusion evaluation of gastric cancer. Correlation with histologic type

    International Nuclear Information System (INIS)

    Lee, Dong Ho; Joo, Ijin; Kim, Se Hyung; Han, Joon Koo

    2018-01-01

    To prospectively evaluate if the perfusion parameters of gastric cancer can provide information on histologic subtypes of gastric cancer. We performed preoperative perfusion CT (PCT) and curative gastrectomy in 46 patients. PCT data were analysed using a dedicated software program. Perfusion parameters were obtained by two independent radiologists and were compared according to histologic type using Kruskal-Wallis, Mann-Whitney U test and receiver operating characteristic analysis. To assess inter-reader agreement, we used intraclass correlation coefficient (ICC). Inter-reader agreement for perfusion parameters was moderate to substantial (ICC = 0.585-0.678). Permeability surface value of poorly cohesive carcinoma (PCC) was significantly higher than other histologic types (47.3 ml/100 g/min in PCC vs 26.5 ml/100 g/min in non-PCC, P < 0.001). Mean transit time (MTT) of PCC was also significantly longer than non-PCC (13.0 s in PCC vs 10.3 s in non-PCC, P = 0.032). The area under the curve to predict PCC was 0.891 (P < 0.001) for permeability surface and 0.697 (P = 0.015) for MTT. Obtaining perfusion parameters from PCT was feasible in gastric cancer patients and can aid in the preoperative imaging diagnosis of PCC-type gastric cancer as the permeability surface and MTT value of PCC type gastric cancer were significantly higher than those of non-PCC. (orig.)

  17. Permanently Hypoxic Cell Culture Yields Rat Bone Marrow Mesenchymal Cells with Higher Therapeutic Potential in the Treatment of Chronic Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Yihua Liu

    2017-11-01

    Full Text Available Background: The mismatch between traditional in vitro cell culture conditions and targeted chronic hypoxic myocardial tissue could potentially hamper the therapeutic effects of implanted bone marrow mesenchymal stem cells (BMSCs. This study sought to address (i the extent of change to BMSC biological characteristics in different in vitro culture conditions and (ii the effectiveness of permanent hypoxic culture for cell therapy in treating chronic myocardial infarction (MI in rats. Methods: rat BMSCs were harvested and cultured in normoxic (21% O2, n=27 or hypoxic conditions (5% O2, n=27 until Passage 4 (P4. Cell growth tests, flow cytometry, and Bio-Plex assays were conducted to explore variations in the cell proliferation, phenotype, and cytokine expression, respectively. In the in vivo set-up, P3-BMSCs cultured in normoxia (n=6 or hypoxia (n=6 were intramyocardially injected into rat hearts that had previously experienced 1-month-old MI. The impact of cell therapy on cardiac segmental viability and hemodynamic performance was assessed 1 month later by 2-Deoxy-2[18F]fluoro-D-glucose (18F-FDG positron emission tomography (PET imaging and pressure-volume catheter, respectively. Additional histomorphological examinations were conducted to evaluate inflammation, fibrosis, and neovascularization. Results: Hypoxic preconditioning significantly enhanced rat BMSC clonogenic potential and proliferation without altering the multipotency. Different profiles of inflammatory, fibrotic, and angiogenic cytokine secretion were also documented, with a marked correlation observed between in vitro and in vivo proangiogenic cytokine expression and tissue neovessels. Hypoxic-preconditioned cells presented a beneficial effect on the myocardial viability of infarct segments and intrinsic contractility. Conclusion: Hypoxic-preconditioned BMSCs were able to benefit myocardial perfusion and contractility, probably by modulating the inflammation and promoting

  18. Permanently Hypoxic Cell Culture Yields Rat Bone Marrow Mesenchymal Cells with Higher Therapeutic Potential in the Treatment of Chronic Myocardial Infarction.

    Science.gov (United States)

    Liu, Yihua; Yang, Xiaoxi; Maureira, Pablo; Falanga, Aude; Marie, Vanessa; Gauchotte, Guillaume; Poussier, Sylvain; Groubatch, Frederique; Marie, Pierre-Yves; Tran, Nguyen

    2017-01-01

    The mismatch between traditional in vitro cell culture conditions and targeted chronic hypoxic myocardial tissue could potentially hamper the therapeutic effects of implanted bone marrow mesenchymal stem cells (BMSCs). This study sought to address (i) the extent of change to BMSC biological characteristics in different in vitro culture conditions and (ii) the effectiveness of permanent hypoxic culture for cell therapy in treating chronic myocardial infarction (MI) in rats. rat BMSCs were harvested and cultured in normoxic (21% O2, n=27) or hypoxic conditions (5% O2, n=27) until Passage 4 (P4). Cell growth tests, flow cytometry, and Bio-Plex assays were conducted to explore variations in the cell proliferation, phenotype, and cytokine expression, respectively. In the in vivo set-up, P3-BMSCs cultured in normoxia (n=6) or hypoxia (n=6) were intramyocardially injected into rat hearts that had previously experienced 1-month-old MI. The impact of cell therapy on cardiac segmental viability and hemodynamic performance was assessed 1 month later by 2-Deoxy-2[18F]fluoro-D-glucose (18F-FDG) positron emission tomography (PET) imaging and pressure-volume catheter, respectively. Additional histomorphological examinations were conducted to evaluate inflammation, fibrosis, and neovascularization. Hypoxic preconditioning significantly enhanced rat BMSC clonogenic potential and proliferation without altering the multipotency. Different profiles of inflammatory, fibrotic, and angiogenic cytokine secretion were also documented, with a marked correlation observed between in vitro and in vivo proangiogenic cytokine expression and tissue neovessels. Hypoxic-preconditioned cells presented a beneficial effect on the myocardial viability of infarct segments and intrinsic contractility. Hypoxic-preconditioned BMSCs were able to benefit myocardial perfusion and contractility, probably by modulating the inflammation and promoting angiogenesis. © 2017 The Author(s). Published by S. Karger AG

  19. How Does the Ca2+-paradox Injury Induce Contracture in the Heart?—A Combined Study of the Intracellular Ca2+ Dynamics and Cell Structures in Perfused Rat Hearts—

    International Nuclear Information System (INIS)

    Mani, Hiroki; Tanaka, Hideo; Adachi, Tetsuya; Ikegawa, Masaya; Dai, Ping; Fujita, Naohisa; Takamatsu, Tetsuro

    2015-01-01

    The calcium (Ca 2+ )-paradox injury of the heart, induced by restoration of extracellular Ca 2+ after its short-term depletion, is known to provoke cardiomyocyte contracture. However, undetermined is how the Ca 2+ -paradox provokes such a distinctive presentation of myocytes in the heart. To address this, we imaged sequential intracellular Ca 2+ dynamics and concomitant structures of the subepicardial ventricular myocytes in fluo3-loaded, Langendorff-perfused rat hearts produced by the Ca 2+ paradox. Under rapid-scanning confocal microscopy, repletion of Ca 2+ following its depletion produced high-frequency Ca 2+ waves in individual myocytes with asynchronous localized contractions, resulting in contracture within 10 min. Such alterations of myocytes were attenuated by 5-mM NiCl 2 , but not by verapamil, SEA0400, or combination of ryanodine and thapsigargin, indicating a contribution of non-specific transmembrane Ca 2+ influx in the injury. However, saponin-induced membrane permeabilization of Ca 2+ showed no apparent contracture despite the emergence of high-frequency Ca 2+ waves, indicating an essential role of myocyte-myocyte and myocyte-extracellular matrix (ECM) mechanical connections in the Ca 2+ paradox. In immunohistochemistry Ca 2+ depletion produced separation of the intercalated disc that expresses cadherin and dissipation of β-dystroglycan located along the sarcolemma. Taken together, along with the trans-sarcolemmal Ca 2+ influx, disruption of cell-cell and cell-ECM connections is essential for contracture in the Ca 2+ -paradox injury

  20. [Intratympanic corticosteroid perfusion in the therapy of Meniere's disease].

    Science.gov (United States)

    Sanković-Babić, Snezana; Kosanović, Rade; Ivanković, Zoran; Babac, Snezana; Tatović, Milica

    2014-01-01

    Over the last two decades the intratympanic perfusion of corticosteroids has been used as a minimally invasive surgical therapy of Meniere's disease. According to experimental studies the antiinflammatory, immunoprotective, antioxidant and neuroprotective role of the locally perfused corticosteroids was noticed in the inner ear structures. The recovery of action potentials in the cells of the Corti organ was confirmed as well as a decreased expression of aquaporine-1, a glycoprotein responsible for labyrinth hydrops and N and K ions derangement. The study showed results of intratympanic perfusion therapy with dexamethasone in patients with retractable Meniere's disease who are resistant to conservative treatment. Single doses of 4 mg/ml dexamethasone were given intratympanically in 19 patients with retractable Meniere's disease. Six single successive doses of dexamethasone were administered in the posteroinferior quadrant of the tympanic membrane. Follow-up of the patients was conducted by using a clinical questionnaire a month after completed perfusion series as well as on every third month up to one year. One month after completed first course of perfusions, in 78% of patients, vertigo problems completely ceased or were markedly reduced. The recovery of hearing function was recorded in 68% and marked tinnitus reduction in 84% of patients. After a year of follow-up, in 63% of patients the reduction of vertigo persisted, while hearing function was satisfactory in 52%. Tinitus reduction was present in 73% of patients. Intratympanic perfusion of dexamethasone in patients with Meniere's disease is a minimally invasive therapeutic method that contributes to the reduction of the intensity of vertigo recurrent attacks, decrease of the intensity of tinnitus and improvement of the average hearing threshold. Patients with chronic diseases and Meniere's disease who are contraindicted for systemic administration of cortocosteroids (hypertension, diabetes, glaucoma, peptic

  1. Differential physiologic effects of perfusion of scala tympani versus scala vestibuli in the ischemic cochlea.

    Science.gov (United States)

    Kobayashi, T; Rokugo, M; Takasaka, T; Thalmann, R

    1993-07-01

    The effectiveness of perilymphatic perfusion with oxygenated artificial media upon the endocochlear potential (EP) was measured during systemic ischemia in the guinea pig. Differences in the effects of perfusion of the two perilymphatic scalae were determined. Perfusion of scala vestibuli with oxygenated artificial perilymph at a high flow rate resulted in complete recovery of the EP to the pre-ischemic level, whereas perfusion of scala tympani with the same medium was unable to effect complete recovery. The recovery obtained by perfusion of scala tympani was about half that obtained of scala vestibuli. The pO2 in scala media was measured during perfusion by means of oxygen-sensitive microelectrodes. perfusion of scala vestibuli led to an approximately two-fold higher pO2 in scala media than perfusion of scala tympani. During perfusion, the pO2 in scala media varied dependent upon depth of electrode insertion, with a gradient decreasing toward the stria vascularis, a direction opposite to that seen under normal metabolic conditions. These findings suggest that, in the ischemic cochlea, oxygen enters scala media more easily from scala vestibuli across Reissner's membrane than from scala tympani via the basilar membrane/organ of Corti complex.

  2. Solar cells from 120 PPMA carbon-contaminated feedstock without significantly higher reverse current or shunt

    Energy Technology Data Exchange (ETDEWEB)

    Manshanden, P.; Coletti, G. [ECN Solar Energy, Petten (Netherlands)

    2012-09-15

    In a bid to drive down the cost of silicon wafers, several options for solar grade silicon feedstock have been investigated over the years. All methods have in common that the resulting silicon contains higher levels of impurities like dopants, oxygen, carbon or transition metals, the type and level of impurities depending on the raw materials and refining processes. In this work wafers from a p-type mc-Si ingot made with feedstock contaminated with 120 ppma of carbon have been processed into solar cells together with reference uncontaminated feedstock from semiconductor grade polysilicon with <0.4 ppma carbon. The results show that comparable reverse current, shunts, and efficiencies can be reached for both types of wafers. Gettering and defect hydrogenation effectiveness also did not deviate from the reference. Electroluminescence pictures do not show increased hotspot formation, even at -16V.

  3. CT hepatic perfusion measurement: Comparison of three analytic methods

    International Nuclear Information System (INIS)

    Kanda, Tomonori; Yoshikawa, Takeshi; Ohno, Yoshiharu; Kanata, Naoki; Koyama, Hisanobu; Takenaka, Daisuke; Sugimura, Kazuro

    2012-01-01

    Objectives: To compare the efficacy of three analytic methods, maximum slope (MS), dual-input single-compartment model (CM) and deconvolution (DC), for CT measurements of hepatic perfusion and assess the effects of extra-hepatic systemic factors. Materials and methods: Eighty-eight patients who were suspected of having metastatic liver tumors underwent hepatic CT perfusion. The scans were performed at the hepatic hilum 7–77 s after administration of contrast material. Hepatic arterial and portal perfusions (HAP and HPP, ml/min/100 ml) and arterial perfusion fraction (APF, %) were calculated with the three methods, followed by correlation assessment. Partial correlation analysis was used to assess the effects on hepatic perfusion values by various factors such as age, sex, risk of cardiovascular diseases, arrival time of contrast material at abdominal aorta, transit time from abdominal aorta to hepatic parenchyma, and liver dysfunction. Results: Mean HAP of MS was significantly higher than DC. HPP of CM was significantly higher than MS and CM, and HPP of MS was significantly higher than DC. There was no significant difference in APF. HAP and APF showed significant and moderate correlations among the methods. HPP showed significant and moderate correlations between CM and DC, and poor correlation between MS and CM or DC. All methods showed weak correlations between HAP or APF and age or sex. Finally, MS showed weak correlations between HAP or HPP and arrival time or cardiovascular risks. Conclusions: Hepatic perfusion values arrived at with the three methods are not interchangeable. CM and DC are less susceptible to extra-hepatic systemic factors

  4. Dynamic CT myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Caruso, Damiano; Eid, Marwen; Schoepf, U. Joseph; Jin, Kwang Nam; Varga-Szemes, Akos; Tesche, Christian; Mangold, Stefanie

    2016-01-01

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  5. Dynamic CT myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncological and Pathological Sciences, University of Rome “Sapienza”, Latina (Italy); Eid, Marwen [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States); Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul (Korea, Republic of); Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Mangold, Stefanie [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Diagnostic and Interventional Radiology, University Hospital of Tuebingen, Tuebingen (Germany); and others

    2016-10-15

    Highlights: • CT myocardial perfusion provides functional assessment of the myocardium. • CCTA is limited in determining the hemodynamic significance of coronary stenosis. • CT-MPI can accurately detect hemodynamically significant coronary artery stenosis. - Abstract: Non-invasive cardiac imaging has rapidly evolved during the last decade due to advancements in CT based technologies. Coronary CT angiography has been shown to reliably assess coronary anatomy and detect high risk coronary artery disease. However, this technique is limited to anatomical assessment, thus non-invasive techniques for functional assessment of the heart are necessary. CT myocardial perfusion is a new CT based technique that provides functional assessment of the myocardium and allows for a comprehensive assessment of coronary artery disease with a single modality when combined with CTA. This review aims to discuss dynamic CT myocardial perfusion as a new technique in the assessment of CAD.

  6. Dynamic CT myocardial perfusion imaging identifies early perfusion abnormalities in diabetes and hypertension : Insights from a multicenter registry

    NARCIS (Netherlands)

    Vliegenthart, Rozemarijn; De Cecco, Carlo N.; Wichmann, Julian L.; Meinel, Felix G.; Pelgrim, Gert Jan; Tesche, Christian; Ebersberger, Ullrich; Pugliese, Francesca; Bamberg, Fabian; Choe, Yeon Hyeon; Wang, Yining; Schoepf, U. Joseph

    2016-01-01

    Background: To identify patients with early signs of myocardial perfusion reduction, a reference base for perfusion measures is needed. Objective: To analyze perfusion parameters derived from dynamic computed tomography perfusion imaging (CTPI) in patients with suspected coronary artery disease

  7. Compartmented pyruvate in perfused working heart

    International Nuclear Information System (INIS)

    Buenger, R.

    1985-01-01

    Pyruvate compartmentation and lactate dehydrogenase (LDH) were studied in isolated perfused working guinea pig hearts. The mean intracellular pyruvate (Pyr) contents increased with perfusate Pyr (0-2 mM) but varied only slightly with glucose (0-10 mM) and additional insulin (0.04-5 U/l), respectively. With 5-10 mM glucose plus 5 U/l insulin, but not with Pyr or lactate (Lac) as substrates, a near equilibrium between the LDH and the glycerol-3-phosphate dehydrogenase seemed to exist. Evidence for an inhibitory effect of Pyr on the activity of the LDH system of the perfused hearts was not obtained. With [U- 14 C]glucose as sole substrate, the specific activity of coronary venous Lac was near half that of precursor glucose. 14 CO 2 production was thus in quantitative agreement with rates of pyruvate oxidation that were determined as glucose uptake minus (Pyr + Lac) release. In contrast, with 0.2 mM [1- 14 C]Pyr plus 5 mM glucose, the ratio of 14 CO 2 production to specific activity of Lac overestimated Pyr oxidation judged from myocardial substrate balances and O 2 uptake, respectively; here, at least three pools of [ 14 C]HCO-3 and [ 14 C]lac, respectively, were kinetically demonstrable during washout of trace amounts of 14 C-labeled Pyr. Evidently, the specific activity of Lac was equivalent to that of mitochondrial oxidized Pyr provided [ 14 C]glucose was the sole or major precursor of cellular pyruvate. However, exogenously applied [1- 14 C]Pyr of high specific activity seemed to induce intracellular formation of both a highly and lowly labeled Pyr; the latter Pyr compartment did not seem in ready equilibrium with the cell physiologically prevailing highly labeled Pyr pool

  8. Automatic assessment of cardiac perfusion MRI

    DEFF Research Database (Denmark)

    Ólafsdóttir, Hildur; Stegmann, Mikkel Bille; Larsson, Henrik B.W.

    2004-01-01

    In this paper, a method based on Active Appearance Models (AAM) is applied for automatic registration of myocardial perfusion MRI. A semi-quantitative perfusion assessment of the registered image sequences is presented. This includes the formation of perfusion maps for three parameters; maximum up...

  9. Higher 5-hydroxymethylcytosine identifies immortal DNA strand chromosomes in asymmetrically self-renewing distributed stem cells.

    Science.gov (United States)

    Huh, Yang Hoon; Cohen, Justin; Sherley, James L

    2013-10-15

    Immortal strands are the targeted chromosomal DNA strands of nonrandom sister chromatid segregation, a mitotic chromosome segregation pattern unique to asymmetrically self-renewing distributed stem cells (DSCs). By nonrandom segregation, immortal DNA strands become the oldest DNA strands in asymmetrically self-renewing DSCs. Nonrandom segregation of immortal DNA strands may limit DSC mutagenesis, preserve DSC fate, and contribute to DSC aging. The mechanisms responsible for specification and maintenance of immortal DNA strands are unknown. To discover clues to these mechanisms, we investigated the 5-methylcytosine and 5-hydroxymethylcytosine (5hmC) content on chromosomes in mouse hair follicle DSCs during nonrandom segregation. Although 5-methylcytosine content did not differ significantly, the relative content of 5hmC was significantly higher in chromosomes containing immortal DNA strands than in opposed mitotic chromosomes containing younger mortal DNA strands. The difference in relative 5hmC content was caused by the loss of 5hmC from mortal chromosomes. These findings implicate higher 5hmC as a specific molecular determinant of immortal DNA strand chromosomes. Because 5hmC is an intermediate during DNA demethylation, we propose a ten-eleven translocase enzyme mechanism for both the specification and maintenance of nonrandomly segregated immortal DNA strands. The proposed mechanism reveals a means by which DSCs "know" the generational age of immortal DNA strands. The mechanism is supported by molecular expression data and accounts for the selection of newly replicated DNA strands when nonrandom segregation is initiated. These mechanistic insights also provide a possible basis for another characteristic property of immortal DNA strands, their guanine ribonucleotide dependency.

  10. Pulmonary ventilation/perfusion scan

    Science.gov (United States)

    ... to stop eating (fast), be on a special diet, or take any medicines before the test. A chest x-ray is usually done before or after a ventilation and perfusion scan. You wear a hospital gown or comfortable clothing that does not have ...

  11. Capturing power at higher voltages from arrays of microbial fuel cells without voltage reversal

    KAUST Repository

    Kim, Younggy

    2011-01-01

    Voltages produced by microbial fuel cells (MFCs) cannot be sustainably increased by linking them in series due to voltage reversal, which substantially reduces stack voltages. It was shown here that MFC voltages can be increased with continuous power production using an electronic circuit containing two sets of multiple capacitors that were alternately charged and discharged (every one second). Capacitors were charged in parallel by the MFCs, but linked in series while discharging to the circuit load (resistor). The parallel charging of the capacitors avoided voltage reversal, while discharging the capacitors in series produced up to 2.5 V with four capacitors. There were negligible energy losses in the circuit compared to 20-40% losses typically obtained with MFCs using DC-DC converters to increase voltage. Coulombic efficiencies were 67% when power was generated via four capacitors, compared to only 38% when individual MFCs were operated with a fixed resistance of 250 Ω. The maximum power produced using the capacitors was not adversely affected by variable performance of the MFCs, showing that power generation can be maintained even if individual MFCs perform differently. Longer capacitor charging and discharging cycles of up to 4 min maintained the average power but increased peak power by up to 2.6 times. These results show that capacitors can be used to easily obtain higher voltages from MFCs, allowing for more useful capture of energy from arrays of MFCs. © 2011 The Royal Society of Chemistry.

  12. Improving Spiking Dynamical Networks: Accurate Delays, Higher-Order Synapses, and Time Cells.

    Science.gov (United States)

    Voelker, Aaron R; Eliasmith, Chris

    2018-03-01

    Researchers building spiking neural networks face the challenge of improving the biological plausibility of their model networks while maintaining the ability to quantitatively characterize network behavior. In this work, we extend the theory behind the neural engineering framework (NEF), a method of building spiking dynamical networks, to permit the use of a broad class of synapse models while maintaining prescribed dynamics up to a given order. This theory improves our understanding of how low-level synaptic properties alter the accuracy of high-level computations in spiking dynamical networks. For completeness, we provide characterizations for both continuous-time (i.e., analog) and discrete-time (i.e., digital) simulations. We demonstrate the utility of these extensions by mapping an optimal delay line onto various spiking dynamical networks using higher-order models of the synapse. We show that these networks nonlinearly encode rolling windows of input history, using a scale invariant representation, with accuracy depending on the frequency content of the input signal. Finally, we reveal that these methods provide a novel explanation of time cell responses during a delay task, which have been observed throughout hippocampus, striatum, and cortex.

  13. Cerebral perfusion characteristics show differences in younger versus older children with sickle cell anaemia: Results from a multiple-inflow-time arterial spin labelling study.

    Science.gov (United States)

    Kawadler, Jamie M; Hales, Patrick W; Barker, Simon; Cox, Timothy C S; Kirkham, Fenella J; Clark, Chris A

    2018-03-30

    Sickle cell anaemia (SCA) is associated with chronic anaemia and oxygen desaturation, which elevate cerebral blood flow (CBF) and increase the risk of neurocognitive complications. Arterial spin labelling (ASL) provides a methodology for measuring CBF non-invasively; however, ASL techniques using only a single inflow time are not sufficient to fully characterize abnormal haemodynamic behaviour in SCA. This study investigated haemodynamic parameters from a multi-inflow-time ASL acquisition in younger (8-12 years) and older (13-18 years) children with SCA with and without silent cerebral infarction (SCI+/-) (n = 20 and 19 respectively, 6 and 4 SCI+ respectively) and healthy controls (n = 9 and 7 respectively). Compared with controls, CBF was elevated globally in both groups of patients. In the younger SCA patients, blood oxygen content was negatively correlated with CBF in the middle and posterior cerebral artery territories and significantly positively correlated with bolus arrival time (BAT) in the anterior and middle cerebral artery territories. In older children, SCA patients had significantly shorter BAT than healthy controls and there was a significant negative correlation between CBF and oxygen content only in the territory of the posterior cerebral artery, with a trend for a correlation in the anterior cerebral artery but no relationship for the middle cerebral artery territory. In the younger group, SCI+ patients had significantly higher CBF in the posterior cerebral artery territory (SCI+ mean = 92.78 ml/100 g/min; SCI- mean = 72.71 ml/100 g/min; F = 4.28, p = 0.04), but this no longer reached significance when two children with abnormal transcranial Doppler and one with haemoglobin SC disease were excluded, and there were no significant differences between patients with and without SCI in the older children. With age, there appears to be increasing disparity between patients and controls in terms of the relationship between CBF and oxygen

  14. Skin Blood Perfusion and Cellular Response to Insertion of Insulin Pen Needles With Different Diameters

    DEFF Research Database (Denmark)

    Præstmark, Kezia Ann; Stallknecht, Bente Merete; Bo Jensen, Casper

    2014-01-01

    skin blood perfusion response around needle insertion sites. Three common sized pen needles of 28G, 30G, and 32G as well as hooked 32G needles, were inserted into the neck skin of pigs and then removed. Laser Speckle Contrast Analysis was used to measure skin blood perfusion for 20 minutes after...... blood perfusion recording and grouped according to needle type, skin blood perfusion response relates to needle diameter. The response was significantly higher after insertions with 28G and hooked 32G needles than with 30G (P ..., but there was a trend of an increased response with increasing needle diameter. Skin blood perfusion response to pen needle insertions rank according to needle diameter, and the tissue response caused by hooked 32G needles corresponds to that of 28G needles. The relation between needle diameter and trauma when...

  15. Argyrophil cell density in the oxyntic mucosa is higher in female than in male morbidly obese patients

    International Nuclear Information System (INIS)

    Maksud, F.A.N.; Kakehasi, A.M.; Barbosa, A.J.A.

    2013-01-01

    Obesity is a multifactorial disorder often associated with many important diseases such as diabetes, hypertension and other metabolic syndrome conditions. Argyrophil cells represent almost the total population of endocrine cells of the human gastric mucosa and some reports have described changes of specific types of these cells in patients with obesity and metabolic syndrome. The present study was designed to evaluate the global population of argyrophil cells of the gastric mucosa of morbidly obese and dyspeptic non-obese patients. Gastric biopsies of antropyloric and oxyntic mucosa were obtained from 50 morbidly obese patients (BMI >40) and 50 non-obese patients (17 dyspeptic overweight and 33 lean individuals) and processed for histology and Grimelius staining for argyrophil cell demonstration. Argyrophil cell density in the oxyntic mucosa of morbidly obese patients was higher in female (238.68 ± 83.71 cells/mm 2 ) than in male patients (179.31 ± 85.96 cells/mm 2 ) and also higher in female (214.20 ± 50.38 cells/mm 2 ) than in male (141.90 ± 61.22 cells/mm 2 ) morbidly obese patients with metabolic syndrome (P = 0.01 and P = 0.02, respectively). In antropyloric mucosa, the main difference in argyrophil cell density was observed between female morbidly obese patients with (167.00 ± 69.30 cells/mm 2 ) and without (234.00 ± 69.54 cells/mm 2 ) metabolic syndrome (P = 0.001). In conclusion, the present results show that the number of gastric argyrophil cells could be under gender influence in patients with morbid obesity. In addition, gastric argyrophil cells seem to behave differently among female morbidly obese patients with and without metabolic syndrome

  16. Argyrophil cell density in the oxyntic mucosa is higher in female than in male morbidly obese patients

    Energy Technology Data Exchange (ETDEWEB)

    Maksud, F.A.N. [Laboratório de Patologia Digestiva e Neuroendócrina, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Faculdade de Medicina, Universidade Federal de Ouro Preto, Ouro Preto, MG (Brazil); Kakehasi, A.M. [Laboratório de Patologia Digestiva e Neuroendócrina, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Barbosa, A.J.A. [Laboratório de Patologia Digestiva e Neuroendócrina, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil); Instituto Alfa de Gastroenterologia, Belo Horizonte, MG (Brazil)

    2013-04-05

    Obesity is a multifactorial disorder often associated with many important diseases such as diabetes, hypertension and other metabolic syndrome conditions. Argyrophil cells represent almost the total population of endocrine cells of the human gastric mucosa and some reports have described changes of specific types of these cells in patients with obesity and metabolic syndrome. The present study was designed to evaluate the global population of argyrophil cells of the gastric mucosa of morbidly obese and dyspeptic non-obese patients. Gastric biopsies of antropyloric and oxyntic mucosa were obtained from 50 morbidly obese patients (BMI >40) and 50 non-obese patients (17 dyspeptic overweight and 33 lean individuals) and processed for histology and Grimelius staining for argyrophil cell demonstration. Argyrophil cell density in the oxyntic mucosa of morbidly obese patients was higher in female (238.68 ± 83.71 cells/mm{sup 2}) than in male patients (179.31 ± 85.96 cells/mm{sup 2}) and also higher in female (214.20 ± 50.38 cells/mm{sup 2}) than in male (141.90 ± 61.22 cells/mm{sup 2}) morbidly obese patients with metabolic syndrome (P = 0.01 and P = 0.02, respectively). In antropyloric mucosa, the main difference in argyrophil cell density was observed between female morbidly obese patients with (167.00 ± 69.30 cells/mm{sup 2}) and without (234.00 ± 69.54 cells/mm{sup 2}) metabolic syndrome (P = 0.001). In conclusion, the present results show that the number of gastric argyrophil cells could be under gender influence in patients with morbid obesity. In addition, gastric argyrophil cells seem to behave differently among female morbidly obese patients with and without metabolic syndrome.

  17. Effects of perfusion detect on the measurement of left ventricular mass, ventricular volume and post-stress left ventricular ejection fraction in gated myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Ahn, Byeong Cheol; Bae, Sun Keun; Lee, Sang Woo; Jeong, Sin Young; Lee, Jae Tae; Lee, Kyu Bo

    2002-01-01

    The presence of perfusion defect may influence the left ventricular mass (LVM) measurement by quantitative gated myocardial perfusion SPECT (QGS), and ischemic myocardium, usually showing perfusion defect may produce post-stress LV dysfunction. This study was aimed to evaluated the effects of extent and reversibility of perfusion defect on the automatic measurement of LVM by QGS and to investigate the effect of reversibility of perfusion defect on post-stress LV dysfunction. Forty-six patients (male/female=34:12, mean age=64 years) with perfusion defect on myocardial perfusion SPECT underwent rest and post-stress QGS. Forty patients (87%) showed reversible defect. End-diastolic volume (EDV), end-systolic volume (ESV), LV ejection fraction (EF), and LV myocardial volume were obtained from QGS by autoquant program, and LVM was calculated by multiplying the LV myocardial volume by the specific gravity of myocardium. LVMs measured at rest and post-stress QGS showed good correlation, and higher correlation was founded in the subjects with fixed perfusion defect and with small defect (smaller than 20%). There were no significant differences in EDVs, ESVs and EFs between obtained by rest and post-stress QGS in patients with fixed myocardial defect. Whereas, EF obtained by post-stress QGS was lower than that by rest QGS in patients with reversible defect and 10 (25%) of them showed decreases in EF more than 5% in post-stress QGS, as compared to that of rest QGS. Excellent correlations of EDVs, ESVs, EFs between rest and post-stress QGS were noted. Patients with fixed defect had higher correlation between defect can affect LVM measurement by QGS and patients with reversible defect shows post-stress LV dysfunction more frequently than patients with fixed perfusion defect

  18. Dynamic Compression Promotes the Matrix Synthesis of Nucleus Pulposus Cells Through Up-Regulating N-CDH Expression in a Perfusion Bioreactor Culture.

    Science.gov (United States)

    Xu, Yichun; Yao, Hui; Li, Pei; Xu, Wenbin; Zhang, Junbin; Lv, Lulu; Teng, Haijun; Guo, Zhiliang; Zhao, Huiqing; Hou, Gang

    2018-01-01

    An adequate matrix production of nucleus pulposus (NP) cells is an important tissue engineering-based strategy to regenerate degenerative discs. Here, we mainly aimed to investigate the effects and mechanism of mechanical compression (i.e., static compression vs. dynamic compression) on the matrix synthesis of three-dimensional (3D) cultured NP cells in vitro. Rat NP cells seeded on small intestinal submucosa (SIS) cryogel scaffolds were cultured in the chambers of a self-developed, mechanically active bioreactor for 10 days. Meanwhile, the NP cells were subjected to compression (static compression or dynamic compression at a 10% scaffold deformation) for 6 hours once per day. Unloaded NP cells were used as controls. The cellular phenotype and matrix biosynthesis of NP cells were investigated by real-time PCR and Western blotting assays. Lentivirus-mediated N-cadherin (N-CDH) knockdown and an inhibitor, LY294002, were used to further investigate the role of N-CDH and the PI3K/Akt pathway in this process. Dynamic compression better maintained the expression of cell-specific markers (keratin-19, FOXF1 and PAX1) and matrix macromolecules (aggrecan and collagen II), as well as N-CDH expression and the activity of the PI3K/Akt pathway, in the 3D-cultured NP cells compared with those expression levels and activity in the cells grown under static compression. Further analysis showed that the N-CDH knockdown significantly down-regulated the expression of NP cell-specific markers and matrix macromolecules and inhibited the activation of the PI3K/Akt pathway under dynamic compression. However, inhibition of the PI3K/Akt pathway had no effects on N-CDH expression but down-regulated the expression of NP cell-specific markers and matrix macromolecules under dynamic compression. Dynamic compression increases the matrix synthesis of 3D-cultured NP cells compared with that of the cells under static compression, and the N-CDH-PI3K/Akt pathway is involved in this regulatory process

  19. Contralateral thalamic hypoperfusion on brain perfusion SPECT

    International Nuclear Information System (INIS)

    Lee, Seok Mo; Bae, Sang Kyun; Yoo, Kyung Moo; Yum, Ha Yong

    2000-01-01

    Brain perfusion single photon emission computed tomography (SPECT) is useful for the localization of cerebrovascular lesion and sometimes reveals more definite lesion than radiologic imaging modality such as CT or MRI does. The purpose of this study was to evaluate the diagnostic usefulness of brain perfusion SPECT in patients with hemisensory impairment. Thirteen consecutive patients (M:F= 8:5, mean age = 48) who has hemisensory impairment were included. Brain perfusion SPECT was performed after intravenous injection of 1110 MBq of Tc-99m ECD. The images were obtained using a dual-head gamma camera with ultra-high resolution collimator. Semiquantitative analysis was performed after placing multiple ROIs on cerebral cortex, basal ganglia, thalamus and cerebellum. There were 10 patients with left hemisensory impairment and 3 patients with right-sided symptom. Only 2 patients revealed abnormal signal change in the thalamus on MRI. But brain perfusion SPECT showed decreased perfusion in the thalamus in 9 patients. Six patients among 10 patients with left hemisensory impairment revealed decreased perfusion in the contralateral thalamus on brain SPECT. The other 4 patients revealed no abnormality. Two patients among 3 patients with right hemisensory impairment also showed decreased perfusion in the contralateral thalamus on brain SPECT. One patients with right hemisensory impairment showed ipsilateral perfusion decrease. Two patients who had follow-up brain perfusion SEPCT after treatment revealed normalization of perfusion in the thalamus. Brain perfusion SPECT might be a useful tool in diagnosing patients with hemisensory impairment

  20. Magnetic resonance perfusion imaging without contrast media

    International Nuclear Information System (INIS)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

    2010-01-01

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  1. Thallium-201 myocardial perfusion imaging during transient coronary occlusion at the time of PTCA

    International Nuclear Information System (INIS)

    Nakagawa, Tatsuya; Sugihara, Hiroki; Inagaki, Suetsugu

    1989-01-01

    To evaluate myocardial perfusion during transient coronary arterial occlusion, thallium-201 was administered intravenously during percutaneous transluminall coronary angioplasty (PTCA) in 12 patients with effort angina, and the resulting perfusion images were compared with those of exercise stress obtained before PTCA. Thallium-201 was injected at the last inflation of an angioplastic baloon and occlusion was maintained for 60 to 90 sec. Three projections of planar images were obtained immediately after PTCA, using a portable gamma camera in an angiography room. These perfusion images obtained during PTCA and exercise were visually interpreted and compared. Myocardial perfusion defects due to the responsible vessel occlusion were observed at early imaging after PTCA, and were fully redistributed three hrs post injection. In 10 patients without angiographically imaged collateral vessels, there were no significatn differences in perfusion between images during PTCA and during exercise. Two patients whose collaterals were observed during coronary angiography before PTCA had higher perfusion scores during PTCA than during exercise. We concluded that intravenous injection of thallium-201 during PTCA is a useful means for assessing alteration of myocardial perfusion due to transient coronary occlusion without increasing the risk of angioplastic procedures, and that it provides more precise information about the jeopardized myocardium, perfused by antegrade blood flow. (author)

  2. Consideration of Normal Variation of Perfusion Measurements in the Quantitative Analysis of Myocardial Perfusion SPECT: Usefulness in Assessment of Viable Myocardium

    International Nuclear Information System (INIS)

    Paeng, Jin Chul; Lim, Il Han; Kim, Ki Bong; Lee, Dong Soo

    2008-01-01

    Although automatic quantification software of myocardial perfusion SPECT provides highly objective and reproducible quantitative measurements, there is still some limitation in the direct use of quantitative measurements. In this study we derived parameters using normal variation of perfusion measurements, and tried to test the usefulness of these parameters. In order to calculate normal variation of perfusion measurements on myocardial perfusion SPECT, 55 patients (M:F=28:27) of low-likelihood for coronary artery disease were enrolled and 201 Tl rest / 99m Tc-MIBI stress SPECT studies were performed. Using 20-segment model, mean (m) and standard deviation (SD) of perfusion were calculated in each segment. As a myocardial viability assessment group, another 48 patients with known coronary artery disease, who underwent coronary artery bypass graft surgery (CABG) were enrolled. 201 Tl rest / 99m Tc-MIBI stress / 201 Tl 24-hr delayed SPECT was performed before CABG and SPECT was followed up 3 months after CABG. From the preoperative 24-hr delayed SPECT, Q delay (perfusion measurement), Δ delay (Q delay .m) and Z delay ((Q delay .m)/SD) were defined and diagnostic performances of them for myocardial viability were evaluated using area under curve (AUC) on receiver operating characteristic (ROC) curve analysis. Segmental perfusion measurements showed considerable normal variations among segments. In men, the lowest segmental perfusion measurement was 51.8±6.5 and the highest segmental perfusion was 87.0±5.9, and they are 58.7±8.1 and 87.3±6.0, respectively in women. In the viability assessment, Q delay showed AUC of 0.633, while those for Δ delay and Z delay were 0.735 and 0.716, respectively. The AUCs of Δ delay and Z delay were significantly higher than that of Q delay (p=0.001 and 0.018, respectively). The diagnostic performance of Δ delay , which showed highest AUC, was 85% of sensitivity and 53% of specificity at the optimal cutoff of -24.7. On automatic

  3. Collagen Promotes Higher Adhesion, Survival and Proliferation of Mesenchymal Stem Cells.

    Directory of Open Access Journals (Sweden)

    Chinnapaka Somaiah

    Full Text Available Mesenchymal stem cells (MSC can differentiate into several cell types and are desirable candidates for cell therapy and tissue engineering. However, due to poor cell survival, proliferation and differentiation in the patient, the therapy outcomes have not been satisfactory. Although several studies have been done to understand the conditions that promote proliferation, differentiation and migration of MSC in vitro and in vivo, still there is no clear understanding on the effect of non-cellular bio molecules. Of the many factors that influence the cell behavior, the immediate cell microenvironment plays a major role. In this context, we studied the effect of extracellular matrix (ECM proteins in controlling cell survival, proliferation, migration and directed MSC differentiation. We found that collagen promoted cell proliferation, cell survival under stress and promoted high cell adhesion to the cell culture surface. Increased osteogenic differentiation accompanied by high active RHOA (Ras homology gene family member A levels was exhibited by MSC cultured on collagen. In conclusion, our study shows that collagen will be a suitable matrix for large scale production of MSC with high survival rate and to obtain high osteogenic differentiation for therapy.

  4. Evaluation of portal hypertension: a comparison of the use of liver perfusion CT with wedge hepatic venous pressure and hepatic

    International Nuclear Information System (INIS)

    Chung, Dong Jin; Kim, Young Joong; Park, Yong Sung; Lee, Tae Hee; Kim, Chong Soo; Kang, Heung Keun

    2008-01-01

    We compared the hepatic perfusion indices obtained using hepatic perfusion CT with the wedge hepatic venous pressure (WHVP) and hepatic venous pressure gradient (HVPG) to determine the efficacy of the use of liver perfusion CT for the evaluation of portal hypertension. Thirty-five patients with liver cirrhosis underwent hepatic vein catheterization to measure WHVP and HVPG and underwent a liver perfusion CT examination. Arterial perfusion, portal perfusion, total perfusion and the hepatic perfusion index (HPI) were calculated by the methods described by Miles and Blomlely. The overall correlation coefficients (r) between the perfusion indices and WHVP and HVPG were calculated. An additional correlation coefficient of 23 alcoholic cirrhosis patients was calculated. Using Blomley's equation, HPI had a positive correlation with WHVP (r = .471; ρ < .05) and HVPG (r = .482; ρ < .05). For the alcoholic liver cirrhosis patients, HPI had a higher positive correlation with WHVP (r = .500; ρ < .05) and HVPG (r = .539; ρ < .05) than for the non-alcoholic cirrhosis patients. There was no statistical difference between the use of Miles' equation and Blomley's equation for the evaluation of portal hypertension. This preliminary study showed that HPI positively correlated with WHVP and HVPG, especially in alcoholic cirrhosis patients. Liver perfusion CT may be useful in the evaluation of portal hypertension

  5. Evaluation of portal hypertension: a comparison of the use of liver perfusion CT with wedge hepatic venous pressure and hepatic

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Dong Jin; Kim, Young Joong; Park, Yong Sung; Lee, Tae Hee [University of Konyang College of Medicine, Daejeon (Korea, Republic of); Kim, Chong Soo; Kang, Heung Keun [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2008-09-15

    We compared the hepatic perfusion indices obtained using hepatic perfusion CT with the wedge hepatic venous pressure (WHVP) and hepatic venous pressure gradient (HVPG) to determine the efficacy of the use of liver perfusion CT for the evaluation of portal hypertension. Thirty-five patients with liver cirrhosis underwent hepatic vein catheterization to measure WHVP and HVPG and underwent a liver perfusion CT examination. Arterial perfusion, portal perfusion, total perfusion and the hepatic perfusion index (HPI) were calculated by the methods described by Miles and Blomlely. The overall correlation coefficients (r) between the perfusion indices and WHVP and HVPG were calculated. An additional correlation coefficient of 23 alcoholic cirrhosis patients was calculated. Using Blomley's equation, HPI had a positive correlation with WHVP (r = .471; {rho} < .05) and HVPG (r = .482; {rho} < .05). For the alcoholic liver cirrhosis patients, HPI had a higher positive correlation with WHVP (r = .500; {rho} < .05) and HVPG (r = .539; {rho} < .05) than for the non-alcoholic cirrhosis patients. There was no statistical difference between the use of Miles' equation and Blomley's equation for the evaluation of portal hypertension. This preliminary study showed that HPI positively correlated with WHVP and HVPG, especially in alcoholic cirrhosis patients. Liver perfusion CT may be useful in the evaluation of portal hypertension.

  6. Guidelines for the use and interpretation of assays for monitoring cell death in higher eukaryotes.

    Science.gov (United States)

    Galluzzi, L; Aaronson, S A; Abrams, J; Alnemri, E S; Andrews, D W; Baehrecke, E H; Bazan, N G; Blagosklonny, M V; Blomgren, K; Borner, C; Bredesen, D E; Brenner, C; Castedo, M; Cidlowski, J A; Ciechanover, A; Cohen, G M; De Laurenzi, V; De Maria, R; Deshmukh, M; Dynlacht, B D; El-Deiry, W S; Flavell, R A; Fulda, S; Garrido, C; Golstein, P; Gougeon, M-L; Green, D R; Gronemeyer, H; Hajnóczky, G; Hardwick, J M; Hengartner, M O; Ichijo, H; Jäättelä, M; Kepp, O; Kimchi, A; Klionsky, D J; Knight, R A; Kornbluth, S; Kumar, S; Levine, B; Lipton, S A; Lugli, E; Madeo, F; Malomi, W; Marine, J-C W; Martin, S J; Medema, J P; Mehlen, P; Melino, G; Moll, U M; Morselli, E; Nagata, S; Nicholson, D W; Nicotera, P; Nuñez, G; Oren, M; Penninger, J; Pervaiz, S; Peter, M E; Piacentini, M; Prehn, J H M; Puthalakath, H; Rabinovich, G A; Rizzuto, R; Rodrigues, C M P; Rubinsztein, D C; Rudel, T; Scorrano, L; Simon, H-U; Steller, H; Tschopp, J; Tsujimoto, Y; Vandenabeele, P; Vitale, I; Vousden, K H; Youle, R J; Yuan, J; Zhivotovsky, B; Kroemer, G

    2009-08-01

    Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases. Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous implications for the development of novel therapeutic strategies. It is, therefore, of utmost importance to standardize the experimental procedures that identify dying and dead cells in cell cultures and/or in tissues, from model organisms and/or humans, in healthy and/or pathological scenarios. Thus far, dozens of methods have been proposed to quantify cell death-related parameters. However, no guidelines exist regarding their use and interpretation, and nobody has thoroughly annotated the experimental settings for which each of these techniques is most appropriate. Here, we provide a nonexhaustive comparison of methods to detect cell death with apoptotic or nonapoptotic morphologies, their advantages and pitfalls. These guidelines are intended for investigators who study cell death, as well as for reviewers who need to constructively critique scientific reports that deal with cellular demise. Given the difficulties in determining the exact number of cells that have passed the point-of-no-return of the signaling cascades leading to cell death, we emphasize the importance of performing multiple, methodologically unrelated assays to quantify dying and dead cells.

  7. Hyperventilation, cerebral perfusion, and syncope

    DEFF Research Database (Denmark)

    Immink, R V; Pott, F C; Secher, N H

    2014-01-01

    dioxide (PaCO2) and oxygen (PaO2) partial pressures so that hypercapnia/hypoxia increases and hypocapnia/hyperoxia reduces global cerebral blood flow. Cerebral hypoperfusion and TLOC have been associated with hypocapnia related to HV. Notwithstanding pronounced cerebrovascular effects of PaCO2...... the contribution of a low PaCO2 to the early postural reduction in middle cerebral artery blood velocity is transient. HV together with postural stress does not reduce cerebral perfusion to such an extent that TLOC develops. However when HV is combined with cardiovascular stressors like cold immersion or reduced...... cardiac output brain perfusion becomes jeopardized. Whether, in patients with cardiovascular disease and/or defect, cerebral blood flow cerebral control HV-induced hypocapnia elicits cerebral hypoperfusion, leading to TLOC, remains to be established....

  8. Myocardial perfusion modeling using MRI

    DEFF Research Database (Denmark)

    Larsson, H B; Fritz-Hansen, T; Rostrup, Egill

    1996-01-01

    In the present study, it is shown that it is possible to quantify myocardial perfusion using magnetic resonance imaging in combination with gadolinium diethylenetriaminopentaacetic acid (Gd-DTPA). Previously, a simple model and method for measuring myocardial perfusion using an inversion recovery...... turbo-FLASH (fast low-angle shot) sequence and Gd-DTPA has been presented. Here, an extension of the model is presented taking into account fast and slow water exchange between the compartments, enabling the calculation of the unidirectional influx constant (Ki) for Gd-DTPA, the distribution volume...... of Gd-DTPA (lambda), the vascular blood volume (Vb), and the time delay through the coronary arteries (delta T). The model was evaluated by computer simulation and used on experimental results from seven healthy subjects. The results in the healthy volunteers for a region of interest placed...

  9. 'Motion frozen' quantification and display of myocardial perfusion gated SPECT

    International Nuclear Information System (INIS)

    Slomka, P.J.; Hurwitz, G.A.; Baddredine, M.; Baranowski, J.; Aladl, U.E.

    2002-01-01

    Aim: Gated SPECT imaging incorporates both functional and perfusion information of the left ventricle (LV). However perfusion data is confounded by the effect of ventricular motion. Most existing quantification paradigms simply add all gated frames and then proceed to extract the perfusion information from static images, discarding the effects of cardiac motion. In an attempt to improve the reliability and accuracy of cardiac SPECT quantification we propose to eliminate the LV motion prior to the perfusion quantification via automated image warping algorithm. Methods: A pilot series of 14 male and 11 female gated stress SPECT images acquired with 8 time bins have been co-registered to the coordinates of the 3D normal templates. Subsequently the LV endo and epi-cardial 3D points (300-500) were identified on end-systolic (ES) and end-diastolic (ED) frames, defining the ES-ED motion vectors. The nonlinear image warping algorithm (thin-plate-spline) was then applied to warp end-systolic frame was onto the end-diastolic frames using the corresponding ES-ED motion vectors. The remaining 6 intermediate frames were also transformed to the ED coordinates using fractions of the motion vectors. Such warped images were then summed to provide the LV perfusion image in the ED phase but with counts from the full cycle. Results: The identification of the ED/ES corresponding points was successful in all cases. The corrected displacement between ED and ES images was up to 25 mm. The summed images had the appearance of the ED frames but have been much less noisy since all the counts have been used. The spatial resolution of such images appeared higher than that of summed gated images, especially in the female scans. These 'motion frozen' images could be displayed and quantified as regular non-gated tomograms including polar map paradigm. Conclusions: This image processing technique may improve the effective image resolution of summed gated myocardial perfusion images used for

  10. Higher percentage of CD133+ cells is associated with poor prognosis in colon carcinoma patients with stage IIIB

    Directory of Open Access Journals (Sweden)

    Zhang Xin

    2009-07-01

    Full Text Available Abstract Background Cancer stem cell model suggested that tumor progression is driven by the overpopulation of cancer stem cells and eradicating or inhibiting the symmetric division of cancer stem cells would become the most important therapeutic strategy. However, clinical evidence for this hypothesis is still scarce. To evaluate the overpopulation hypothesis of cancer stem cells the association of percentage of CD133+ tumor cells with clinicopathological parameters in colon cancer was investigated since CD133 is a putative cancer stem cell marker shared by multiple solid tumors. Patients and methods Tumor tissues matched with adjacent normal tissues were collected from 104 stage IIIB colon cancer patients who were subject to radical resection between January, 1999 to July, 2003 in this center. The CD133 expression was examined with immunohistochemical staining. The correlation of the percentage of CD133+ cell with clinicopathological parameters and patients' 5-year survival was analyzed. Results The CD133+ cells were infrequent and heterogeneous distribution in the cancer tissue. Staining of CD133 was localized not only on the glandular-luminal surface of cancer cells but also on the invasive budding and the poorly differentiated tumors with ductal structures. Both univariate and multivariate survival analysis revealed that the percentage of CD133+ cancer cells and the invasive depth of tumor were independently prognostic. The patients with a lower percentage of CD133+ cancer cells (less than 5% were strongly associated with a higher 5-year survival rate than those with a higher percentage of CD133+ cancer cells (greater than or equal to 55%. Additionally, no correlation was obtained between the percentage of CD133+ cancer cells and the other clinicopathological parameters including gender, age, site of primary mass, pathologic types, grades, and invasive depth. Conclusion The fact that a higher percentage CD133+ cells were strongly associated

  11. DiI Perfusion as a Method for Vascular Visualization in Ambystoma mexicanum.

    Science.gov (United States)

    Saltman, Anna J; Barakat, May; Bryant, Donald M; Brodovskaya, Anastasia; Whited, Jessica L

    2017-06-16

    Perfusion techniques have been used for centuries to visualize the circulation of tissues. Axolotl (Ambystoma mexicanum) is a species of salamander that has emerged as an essential model for regeneration studies. Little is known about how revascularization occurs in the context of regeneration in these animals. Here we report a simple method for visualization of the vasculature in axolotl via perfusion of 1,1'-Dioctadecy-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI). DiI is a lipophilic carbocyanine dye that inserts into the plasma membrane of endothelial cells instantaneously. Perfusion is done using a peristaltic pump such that DiI enters the circulation through the aorta. During perfusion, dye flows through the axolotl's blood vessels and incorporates into the lipid bilayer of vascular endothelial cells upon contact. The perfusion procedure takes approximately one hour for an eight-inch axolotl. Immediately after perfusion with DiI, the axolotl can be visualized with a confocal fluorescent microscope. The DiI emits light in the red-orange range when excited with a green fluorescent filter. This DiI perfusion procedure can be used to visualize the vascular structure of axolotls or to demonstrate patterns of revascularization in regenerating tissues.

  12. Dosimetry in myocardial perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C. [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear. Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2011-07-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  13. Dosimetry in myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Toledo, Janine M.; Trindade, Bruno; Ribeiro, Tarcisio P.C.

    2011-01-01

    This paper conducts a dosimetric investigation on the myocardial perfusion image protocol, together with a literature reviewing, motivated by the significant statistic increasing on mortality, morbidity and disability associated with cardiovascular disease, surpassing infectious diseases. Nuclear Cardiology plays a role n the diagnostic functional evaluation of the heart and in the prognostic of patients with suspected or known cardiac ischemia. In the context of unstable myocardial ischemic syndrome, myocardial perfusion scintigraphy is a non-invasive procedure performed by administering a radiopharmaceutical targeted to the heart. As tool for this study are that the images obtained by thoracic angiotomography and abdominal aorta as a anatomic and functional information for model reproduction in SISCODES - System of Codes for Absorbed Dose Calculations based on Stochastic Methods. Data were manipulated in order to create a voxel computational model of the heart to be running in MCNP - Monte Carlo Neutron Particle Code. . It was assumed a homogeneous distribution of Tl-201 in cardiac muscle. Simulations of the transport of particles through the voxel and the interaction with the heart tissue were performed. As a result, the isodose curves in the heart model are displayed as well as the dose versus volume histogram of the heart muscle. We conclude that the present computational tools can generate doses distributed in myocardial perfusion. (author)

  14. Guidelines for the use and interpretation of assays for monitoring cell death in higher eukaryotes

    NARCIS (Netherlands)

    Galluzzi, L.; Aaronson, S. A.; Abrams, J.; Alnemri, E. S.; Andrews, D. W.; Baehrecke, E. H.; Bazan, N. G.; Blagosklonny, M. V.; Blomgren, K.; Borner, C.; Bredesen, D. E.; Brenner, C.; Castedo, M.; Cidlowski, J. A.; Ciechanover, A.; Cohen, G. M.; de Laurenzi, V.; de Maria, R.; Deshmukh, M.; Dynlacht, B. D.; El-Deiry, W. S.; Flavell, R. A.; Fulda, S.; Garrido, C.; Golstein, P.; Gougeon, M.-L.; Green, D. R.; Gronemeyer, H.; Hajnóczky, G.; Hardwick, J. M.; Hengartner, M. O.; Ichijo, H.; Jäättelä, M.; Kepp, O.; Kimchi, A.; Klionsky, D. J.; Knight, R. A.; Kornbluth, S.; Kumar, S.; Levine, B.; Lipton, S. A.; Lugli, E.; Madeo, F.; Malorni, W.; Marine, J.-Cw; Martin, S. J.; Medema, J. P.; Mehlen, P.; Melino, G.; Moll, U. M.; Morselli, E.; Nagata, S.; Nicholson, D. W.; Nicotera, P.; Nuñez, G.; Oren, M.; Penninger, J.; Pervaiz, S.; Peter, M. E.; Piacentini, M.; Prehn, J. H. M.; Puthalakath, H.; Rabinovich, G. A.; Rizzuto, R.; Rodrigues, C. M. P.; Rubinsztein, D. C.; Rudel, T.; Scorrano, L.; Simon, H.-U.; Steller, H.; Tschopp, J.; Tsujimoto, Y.; Vandenabeele, P.; Vitale, I.; Vousden, K. H.; Youle, R. J.; Yuan, J.; Zhivotovsky, B.; Kroemer, G.

    2009-01-01

    Cell death is essential for a plethora of physiological processes, and its deregulation characterizes numerous human diseases. Thus, the in-depth investigation of cell death and its mechanisms constitutes a formidable challenge for fundamental and applied biomedical research, and has tremendous

  15. Higher acid-chlorite reactivity of cell corner middle lamella lignin in black spruce

    Science.gov (United States)

    Umesh P. Agarwal

    2007-01-01

    To determine if there was a delignification behavior difference between secondary wall (S2) and middle lamella (cell corner or CC) lignin, black spruce cross-sections were acid-chlorite delignified and the tissue was evaluated in-situ by Raman imaging. Lignin concentration in S2 and CC was determined in numerous latewood cell areas in the two hour delignified cross...

  16. Perfusion abnormalities in congenital and neoplastic pulmonary disease: comparison of MR perfusion and multislice CT imaging

    International Nuclear Information System (INIS)

    Boll, Daniel T.; Lewin, Jonathan S.; Young, Philip; Gilkeson, Robert C.; Siwik, Ernest S.

    2005-01-01

    The aim of this work was to assess magnetic resonance (MR) perfusion patterns of chronic, nonembolic pulmonary diseases of congenital and neoplastic origin and to compare the findings with results obtained with pulmonary, contrast-enhanced multislice computed tomography (CT) imaging to prove that congenital and neoplastic pulmonary conditions require MR imaging over the pulmonary perfusion cycle to successfully and directly detect changes in lung perfusion patterns. Twenty-five patients underwent concurrent CT and MR evaluation of chronic pulmonary diseases of congenital (n=15) or neoplastic (n=10) origin. Analysis of MR perfusion and contrast-enhanced CT datasets was realized by defining pulmonary and vascular regions of interest in corresponding positions. MR perfusion calculated time-to-peak enhancement, maximal enhancement and the area under the perfusion curve. CT datasets provided pulmonary signal-to-noise ratio measurements. Vessel centerlines of bronchial arteries were determined. Underlying perfusion type, such as pulmonary arterial or systemic arterial supply, as well as regions with significant variations in perfusion were determined statistically. Analysis of the pulmonary perfusion pattern detected pulmonary arterial supply in 19 patients; six patients showed systemic arterial supply. In pulmonary arterial perfusion, MR and multislice CT imaging consistently detected the perfusion type and regions with altered perfusion patterns. In bronchial arterial supply, MR perfusion and CT imaging showed significant perfusion differences. Patients with bronchial arterial supply had bronchial arteries ranging from 2.0 to 3.6 mm compared with submillimeter diameters in pulmonary arterial perfusion. Dynamic MR imaging of congenital and neoplastic pulmonary conditions allowed characterization of the pulmonary perfusion type. CT imaging suggested the presence of systemic arterial perfusion by visualizing hypertrophied bronchial arteries. (orig.)

  17. Assessment of pulmonary parenchyma perfusion with FAIR in comparison with DCE-MRI-Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Fan Li [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: fanli0930@163.com; Liu Shiyuan [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China); Sun Fei [GE Healthcare China (China)], E-mail: Fei.sun@med.ge.com; Xiao Xiangsheng [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: lizhaobin79@163.com

    2009-04-15

    Objective: The aim of this study was to assess pulmonary parenchyma perfusion with flow-sensitive alternating inversion recovery (FAIR) in comparison with 3D dynamic contrast-enhanced (DCE) imaging in healthy volunteers and in patients with pulmonary embolism or lung cancer. Materials and methods: Sixteen healthy volunteers and 16 patients with pulmonary embolism (5 cases) or lung cancer (11 cases) were included in this study. Firstly, the optimized inversion time of FAIR (TI) was determined in 12 healthy volunteers. Then, FAIR imaging with the optimized TI was performed followed by DCE-MRI on the other 4 healthy volunteers and 16 patients. Tagging efficiency of lung and SNR of perfusion images were calculated with different TI values. In the comparison of FAIR with DCE-MRI, the homogeneity of FAIR and DCE-MRI perfusion was assessed. In the cases of perfusion abnormality, the contrast between normal lung and perfusion defects was quantified by calculating a normalized signal intensity ratio. Results: One thousand milliseconds was the optimal TI, which generated the highest lung tagging efficiency and second highest PBF SNR. In the volunteers, the signal intensity of perfusion images acquired with both FAIR and DCE-MRI was homogeneous. Wedged-shaped or triangle perfusion defects were visualized in five pulmonary embolisms and three lung cancer cases. There was no significant statistical difference in signal intensity ratio between FAIR and DCE-MRI (P > 0.05). In the rest of eight lung cancers, all the lesions showed low perfusion against the higher perfused pulmonary parenchyma in both FAIR and DCE-MRI. Conclusion: Pulmonary parenchyma perfusion imaging with FAIR was feasible, consistent and could obtain similar functional information to that from DCE-MRI.

  18. Assessment of pulmonary parenchyma perfusion with FAIR in comparison with DCE-MRI-Initial results

    International Nuclear Information System (INIS)

    Fan Li; Liu Shiyuan; Sun Fei; Xiao Xiangsheng

    2009-01-01

    Objective: The aim of this study was to assess pulmonary parenchyma perfusion with flow-sensitive alternating inversion recovery (FAIR) in comparison with 3D dynamic contrast-enhanced (DCE) imaging in healthy volunteers and in patients with pulmonary embolism or lung cancer. Materials and methods: Sixteen healthy volunteers and 16 patients with pulmonary embolism (5 cases) or lung cancer (11 cases) were included in this study. Firstly, the optimized inversion time of FAIR (TI) was determined in 12 healthy volunteers. Then, FAIR imaging with the optimized TI was performed followed by DCE-MRI on the other 4 healthy volunteers and 16 patients. Tagging efficiency of lung and SNR of perfusion images were calculated with different TI values. In the comparison of FAIR with DCE-MRI, the homogeneity of FAIR and DCE-MRI perfusion was assessed. In the cases of perfusion abnormality, the contrast between normal lung and perfusion defects was quantified by calculating a normalized signal intensity ratio. Results: One thousand milliseconds was the optimal TI, which generated the highest lung tagging efficiency and second highest PBF SNR. In the volunteers, the signal intensity of perfusion images acquired with both FAIR and DCE-MRI was homogeneous. Wedged-shaped or triangle perfusion defects were visualized in five pulmonary embolisms and three lung cancer cases. There was no significant statistical difference in signal intensity ratio between FAIR and DCE-MRI (P > 0.05). In the rest of eight lung cancers, all the lesions showed low perfusion against the higher perfused pulmonary parenchyma in both FAIR and DCE-MRI. Conclusion: Pulmonary parenchyma perfusion imaging with FAIR was feasible, consistent and could obtain similar functional information to that from DCE-MRI.

  19. Laser microsurgery of higher plant cell walls permits patch-clamp access

    International Nuclear Information System (INIS)

    Henriksen, G.H.; Taylor, A.R.; Brownlee, C.; Assmann, S.M.

    1996-01-01

    Plasma membranes of guard cells in epidermal peels of Vicia faba and Commelina communis can be made accessible to a patch-clamp pipet by removing a small portion (1-3 micrometer in diameter) of the guard cell wall using a microbeam of ultraviolet light generated by a nitrogen laser. Using this laser microsurgical technique, we have measured channel activity across plasma membranes of V. faba guard cells in both cell-attached and isolated patch configurations. Measurements made in the inside-out patch configuration revealed two distinct K+-selective channels. Major advantages of the laser microsurgical technique include the avoidance of enzymatic protoplast isolation, the ability to study cell types that have been difficult to isolate as protoplasts or for which enzymatic isolation protocols result in protoplasts not amenable to patch-clamp studies, the maintenance of positional information in single-channel measurements, reduced disruption of cell-wall-mediated signaling pathways, and the ability to investigate intercellular signaling through studies of cells remaining situated within tissue

  20. Disposition kinetics of diclofenac in the dual perfused rat liver.

    Science.gov (United States)

    Sahin, Selma; Rowland, Malcolm

    2013-09-01

    This study investigates the hepatic disposition of diclofenac as a function of route of input: portal vein (PV) versus hepatic artery (HA) in the presence of its binding protein, albumin. The in situ dual perfused rat liver was performed using Krebs bicarbonate buffer containing human serum albumin (HSA, 0.25%-1%) at constant PV (12 mL/min) and HA (3 mL/min) flow rates. Bolus doses of [(14) C]-diclofenac and (125) I-labeled HSA were injected randomly into the HA or PV and then, after an appropriate interval, into the alternate vessel. Regardless of route of input and perfusion medium protein concentration, the hepatic outflow profile of diclofenac displayed a characteristic sharp peak followed by a slower eluting tail, indicating that its radial distribution is not instantaneous. Based on the estimated effective permeability-surface area product/blood flow ratio, hepatic uptake of diclofenac is governed by both perfusion and permeability. Fractional effluent recovery (F) increased as unbound diclofenac fraction in the perfusate decreased. Although no significant difference in hepatic clearance of diclofenac as a function of route of delivery at 0.5% and 1% HSA, it was demonstrable at 0.25% HSA (p < 0.001), when the extraction ratio is higher. Copyright © 2013 Wiley Periodicals, Inc.

  1. Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas

    International Nuclear Information System (INIS)

    Matsumoto, Takehisa; Kanno, Tomio; Seo, Yoshiteru; Murakami, Masataka; Watari, Hiroshi

    1988-01-01

    Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degree C). 31 P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (P i ) and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and P i increased. At that time, the P i resonance shfted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 μM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly

  2. The acid perfusion test in gastroesophageal reflux disease

    International Nuclear Information System (INIS)

    Kaul, B.; Petersen, H.; Grette, K.; Myrvold, H.E.

    1986-01-01

    An acid perfusion test, isotope scanning, endoscopy, and esophageal biopsy were performed in 101 patients with symptoms strongly suggestive of gastroesophageal reflux (GER) disease. A positive acid perfusion test within 30 min (APT) and within 5 min (TAPT) was found in 70.2% and 37.6% of the patients, respectively. A positive APT was found significantly more often in patients with than without endoscopic esophagitis, whereas a positive TAPT was found significantly more often in patients with severe symptoms than in patients with moderate symptoms, and in a significantly higher proportion of patients with than without GER by scintigraphy. Neither the APT nor the TAPT showed any dependency on the presence of histologic esophagitis. Most (97%) patients with a negative acid perfusion test, in addition to typical symptoms, also presented with scintigraphic, endoscopic, or histologic evidence of GER disease. Although it shows that the acid perfusion test, particularly when early positive, may serve as a weak predictor of the severity of GER disease, the present study gives little support to the test's clinical usefulness

  3. Pulmonary artery perfusion versus no pulmonary perfusion during cardiopulmonary bypass in patients with COPD

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Sundskard, Martin M; Jonassen, Thomas

    2016-01-01

    INTRODUCTION: Absence of pulmonary perfusion during cardiopulmonary bypass (CPB) may be associated with reduced postoperative oxygenation. Effects of active pulmonary artery perfusion were explored in patients with chronic obstructive pulmonary disease (COPD) undergoing cardiac surgery. METHODS: 90...... perfusion with normothermic oxygenated blood during cardiopulmonary bypass appears to improve postoperative oxygenation in patients with COPD undergoing cardiac surgery. Pulmonary artery perfusion with hypothermic HTK solution does not seem to improve postoperative oxygenation. TRIAL REGISTRATION NUMBER...

  4. Effects of Initial Seeding Density and Fluid Perfusion Rate on Formation of Tissue-Engineered Bone

    OpenAIRE

    GRAYSON, WARREN L.; BHUMIRATANA, SARINDR; CANNIZZARO, CHRISTOPHER; CHAO, P.-H. GRACE; LENNON, DONALD P.; CAPLAN, ARNOLD I.; VUNJAK-NOVAKOVIC, GORDANA

    2008-01-01

    We describe a novel bioreactor system for tissue engineering of bone that enables cultivation of up to six tissue constructs simultaneously, with direct perfusion and imaging capability. The bioreactor was used to investigate the relative effects of initial seeding density and medium perfusion rate on the growth and osteogenic differentiation patterns of bone marrow–derived human mesenchymal stem cells (hMSCs) cultured on three-dimensional scaffolds. Fully decellularized bovine trabecular bon...

  5. Normal anatomy of lung perfusion SPECT scintigraphy

    International Nuclear Information System (INIS)

    Moskowitz, G.W.; Levy, L.M.

    1987-01-01

    Ten patients studies for possible pulmonary embolic disease had normal lung perfusion planar and SPECT scintigraphy. A computer program was developed to superimpose the CT scans on corresponding SPECT images. Superimposition of CT scans on corresponding SPECT transaxial cross-sectional images, when available, provides the needed definition and relationships of adjacent organs. SPECT transaxial sections provide clear anatomic definition of perfusion defects without foreground and background lung tissue superimposed. The location, shape, and size of the perfusion defects can be readily assessed by SPECT. An algorithm was developed for the differentiation of abnormal pulmonary perfusion patterns from normal structures on variation

  6. Myocardial CT perfusion imaging and SPECT for the diagnosis of coronary artery disease

    DEFF Research Database (Denmark)

    George, Richard T; Mehra, Vishal C; Chen, Marcus Y

    2014-01-01

    %, respectively, for SPECT. CONCLUSION: The overall performance of myocardial CT perfusion imaging in the diagnosis of anatomic CAD (stenosis ≥50%), as demonstrated with the Az, was higher than that of SPECT and was driven in part by the higher sensitivity for left main and multivessel disease.......PURPOSE: To compare the diagnostic performance of myocardial computed tomographic (CT) perfusion imaging and single photon emission computed tomography (SPECT) perfusion imaging in the diagnosis of anatomically significant coronary artery disease (CAD) as depicted at invasive coronary angiography....... MATERIALS AND METHODS: This study was approved by the institutional review board. Written informed consent was obtained from all patients. Sixteen centers enrolled 381 patients from November 2009 to July 2011. Patients underwent rest and adenosine stress CT perfusion imaging and rest and either exercise...

  7. Frozen cord blood hematopoietic stem cells differentiate into higher numbers of functional natural killer cells in vitro than mobilized hematopoietic stem cells or freshly isolated cord blood hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Martha Luevano

    Full Text Available Adoptive natural killer (NK cell therapy relies on the acquisition of large numbers of NK cells that are cytotoxic but not exhausted. NK cell differentiation from hematopoietic stem cells (HSC has become an alluring option for NK cell therapy, with umbilical cord blood (UCB and mobilized peripheral blood (PBCD34(+ being the most accessible HSC sources as collection procedures are less invasive. In this study we compared the capacity of frozen or freshly isolated UCB hematopoietic stem cells (CBCD34(+ and frozen PBCD34(+ to generate NK cells in vitro. By modifying a previously published protocol, we showed that frozen CBCD34(+ cultures generated higher NK cell numbers without loss of function compared to fresh CBCD34(+ cultures. NK cells generated from CBCD34(+ and PBCD34(+ expressed low levels of killer-cell immunoglobulin-like receptors but high levels of activating receptors and of the myeloid marker CD33. However, blocking studies showed that CD33 expression did not impact on the functions of the generated cells. CBCD34(+-NK cells exhibited increased capacity to secrete IFN-γ and kill K562 in vitro and in vivo as compared to PBCD34(+-NK cells. Moreover, K562 killing by the generated NK cells could be further enhanced by IL-12 stimulation. Our data indicate that the use of frozen CBCD34(+ for the production of NK cells in vitro results in higher cell numbers than PBCD34(+, without jeopardizing their functionality, rendering them suitable for NK cell immunotherapy. The results presented here provide an optimal strategy to generate NK cells in vitro for immunotherapy that exhibit enhanced effector function when compared to alternate sources of HSC.

  8. Structural and cell adhesion properties of zebrafish syndecan-4 are shared with higher vertebrates

    DEFF Research Database (Denmark)

    Whiteford, James; Ko, Sunggeon; Lee, Weontae

    2008-01-01

    , but no molecular and cellular studies have been reported. Here it is demonstrated that key functional attributes of syndecan-4 are common to both zebrafish and mammalian homologues. These include glycosaminoglycan substitution, a NXIP motif in the extracellular domain that promotes integrin-mediated cell adhesion......The syndecan proteoglycans are an ancient class of receptor, bearing heparan sulfate chains that interact with numerous potential ligands including growth factors, morphogens, and extracellular matrix molecules. The single syndecan of invertebrates appears not to have cell adhesion roles......, but these have been described for mammalian paralogues, especially syndecan-4. This member is best understood in terms of interactions, signaling, and structure of its cytoplasmic domain. The zebrafish homologue of syndecan-4 has been genetically linked to cell adhesion and migration in zebrafish embryos...

  9. Fucoidan cytotoxicity against human breast cancer T47D cell line increases with higher level of sulfate ester group

    Science.gov (United States)

    Saepudin, Endang; Alfita Qosthalani, Fildzah; Sinurat, Ellya

    2018-01-01

    The anticancer activity of different sulfate ester group content in different molecular weight was examined. The anticancer activity was achieved in vitro on human breast cancer T47D cell line. Fucoidan with lower molecular weight (5.79 kDa) tends to have lower sulfate ester group content (8.69%) and resulted in higher IC50 value (184.22 μg/mL). While fucoidan with higher molecular weight (785.12 kDa) tends to have higher sulfate level (18.63%) and achieved lower IC50 value (75.69 μg/mL). The result showed that in order to maintain fucoidan cytotoxic activity against human breast cancer T47D cell line, the sulfate content should be remain high. Keywords: fucoidan, sulfate ester group, human breast cancer

  10. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: A cholinesterase dependent mechanism

    International Nuclear Information System (INIS)

    Del Pino, Javier; Zeballos, Garbriela; Anadon, María José; Capo, Miguel Andrés; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2014-01-01

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases

  11. Quantitative imaging by pixel-based contrast-enhanced ultrasound reveals a linear relationship between synovial vascular perfusion and the recruitment of pathogenic IL-17A-F+IL-23+ CD161+ CD4+ T helper cells in psoriatic arthritis joints.

    Science.gov (United States)

    Fiocco, Ugo; Stramare, Roberto; Martini, Veronica; Coran, Alessandro; Caso, Francesco; Costa, Luisa; Felicetti, Mara; Rizzo, Gaia; Tonietto, Matteo; Scanu, Anna; Oliviero, Francesca; Raffeiner, Bernd; Vezzù, Maristella; Lunardi, Francesca; Scarpa, Raffaele; Sacerdoti, David; Rubaltelli, Leopoldo; Punzi, Leonardo; Doria, Andrea; Grisan, Enrico

    2017-02-01

    To develop quantitative imaging biomarkers of synovial tissue perfusion by pixel-based contrast-enhanced ultrasound (CEUS), we studied the relationship between CEUS synovial vascular perfusion and the frequencies of pathogenic T helper (Th)-17 cells in psoriatic arthritis (PsA) joints. Eight consecutive patients with PsA were enrolled in this study. Gray scale CEUS evaluation was performed on the same joint immediately after joint aspiration, by automatic assessment perfusion data, using a new quantification approach of pixel-based analysis and the gamma-variate model. The set of perfusional parameters considered by the time intensity curve includes the maximum value (peak) of the signal intensity curve, the blood volume index or area under the curve, (BVI, AUC) and the contrast mean transit time (MTT). The direct ex vivo analysis of the frequencies of SF IL17A-F + CD161 + IL23 + CD4 + T cells subsets were quantified by fluorescence-activated cell sorter (FACS). In cross-sectional analyses, when tested for multiple comparison setting, a false discovery rate at 10%, a common pattern of correlations between CEUS Peak, AUC (BVI) and MTT parameters with the IL17A-F + IL23 + - IL17A-F + CD161 + - and IL17A-F + CD161 + IL23 + CD4 + T cells subsets, as well as lack of correlation between both peak and AUC values and both CD4 + T and CD4 + IL23 + T cells, was observed. The pixel-based CEUS assessment is a truly measure synovial inflammation, as a useful tool to develop quantitative imaging biomarker for monitoring target therapeutics in PsA.

  12. Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients.

    Science.gov (United States)

    Le Faivre, Julien; Duhamel, Alain; Khung, Suonita; Faivre, Jean-Baptiste; Lamblin, Nicolas; Remy, Jacques; Remy-Jardin, Martine

    2016-11-01

    To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. • Dual-energy computed tomography generates standard diagnostic imaging and lung perfusion analysis. • Depiction of CPE on central arteries relies on standard diagnostic imaging. • Detection of peripheral CPE is improved by perfusion imaging.

  13. Commercial software upgrades may significantly alter Perfusion CT parameter values in colorectal cancer

    International Nuclear Information System (INIS)

    Goh, Vicky; Shastry, Manu; Endozo, Raymondo; Groves, Ashley M.; Engledow, Alec; Peck, Jacqui; Reston, Jonathan; Wellsted, David M.; Rodriguez-Justo, Manuel; Taylor, Stuart A.; Halligan, Steve

    2011-01-01

    To determine how commercial software platform upgrades impact on derived parameters for colorectal cancer. Following ethical approval, 30 patients with suspected colorectal cancer underwent Perfusion CT using integrated 64 detector PET/CT before surgery. Analysis was performed using software based on modified distributed parameter analysis (Perfusion software version 4; Perfusion 4.0), then repeated using the previous version (Perfusion software version 3; Perfusion 3.0). Tumour blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were determined for identical regions-of-interest. Slice-by-slice and 'whole tumour' variance was assessed by Bland-Altman analysis. Mean BF, BV and PS was 20.4%, 59.5%, and 106% higher, and MTT 14.3% shorter for Perfusion 4.0 than Perfusion 3.0. The mean difference (95% limits of agreement) were +13.5 (-44.9 to 72.0), +2.61 (-0.06 to 5.28), -1.23 (-6.83 to 4.36), and +14.2 (-4.43 to 32.8) for BF, BV, MTT and PS respectively. Within subject coefficient of variation was 36.6%, 38.0%, 27.4% and 60.6% for BF, BV, MTT and PS respectively indicating moderate to poor agreement. Software version upgrades of the same software platform may result in significantly different parameter values, requiring adjustments for cross-version comparison. (orig.)

  14. Reversible defects on myocardial perfusion imaging early after coronary stent implantation: a predictor of late restenosis

    International Nuclear Information System (INIS)

    Kim, D. E.; Park, S. A.; Kim, C. K.; Chang, J. A.; Jeong, J. W.; Oh, S. G.; Lee, C.

    2007-01-01

    It appears logical that myocardial perfusion should be fixed and not reversible, in the territory supplied by a dilated coronary artery. However, several studies have demonstrated reversible perfusion in the territory supplied by a coronary artery with an optimally implanted stent. The main objective of this study was to evaluate the incidence of reversible defects detected by M-SPECT early after optimal PTCA with stent implantation. Its second objective was to determine the predictive value of detecting reversible defects after stent implantation for late restenosis. Sixty-six patients that underwent M-SPECT within 24 hours of successful PTCA with stent implantation were included. All patients were followed up clinically and angiographically. The incidence of reversible perfusion defects on M-SPECT and the rate of late restenosis in target coronary arteries were evaluated retrospectively. Reversible perfusion defects on M-SPECT were observed in 26% of the patients and in 36% of lesions following successful PTCA with stent implantation. The incidence of late restenosis was significantly higher in patients and lesions with reversible perfusion defects (47% vs. 18%). According to binary logistic regression analysis, the presence of a reversible perfusion defects was the only independent predictor of late restenosis. This study shows that the predictive value of reversible perfusion defects on M-SPECT early after stent implantation with respect to the incidence of late restenosis was 47% in patients with a reversible defect, and 18% in those without it

  15. Multiparametric imaging of patient and tumour heterogeneity in non-small-cell lung cancer: quantification of tumour hypoxia, metabolism and perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Elmpt, Wouter van; Zegers, Catharina M.L.; Reymen, Bart; Even, Aniek J.G.; Oellers, Michel; Troost, Esther G.C.; Lambin, Philippe [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO), GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Dingemans, Anne-Marie C. [Maastricht University Medical Centre, Department of Pulmonology, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Centre, Department of Radiology, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); Mottaghy, Felix M. [Maastricht University Medical Centre, Department of Nuclear Medicine, GROW - School for Oncology and Developmental Biology, Maastricht (Netherlands); University Hospital RWTH Aachen University, Department of Nuclear Medicine, Aachen (Germany)

    2016-02-15

    Multiple imaging techniques are nowadays available for clinical in-vivo visualization of tumour biology. FDG PET/CT identifies increased tumour metabolism, hypoxia PET visualizes tumour oxygenation and dynamic contrast-enhanced (DCE) CT characterizes vasculature and morphology. We explored the relationships among these biological features in patients with non-small-cell lung cancer (NSCLC) at both the patient level and the tumour subvolume level. A group of 14 NSCLC patients from two ongoing clinical trials (NCT01024829 and NCT01210378) were scanned using FDG PET/CT, HX4 PET/CT and DCE CT prior to chemoradiotherapy. Standardized uptake values (SUV) in the primary tumour were calculated for the FDG and hypoxia HX4 PET/CT scans. For hypoxia imaging, the hypoxic volume, fraction and tumour-to-blood ratio (TBR) were also defined. Blood flow and blood volume were obtained from DCE CT imaging. A tumour subvolume analysis was used to quantify the spatial overlap between subvolumes. At the patient level, negative correlations were observed between blood flow and the hypoxia parameters (TBR >1.2): hypoxic volume (-0.65, p = 0.014), hypoxic fraction (-0.60, p = 0.025) and TBR (-0.56, p = 0.042). At the tumour subvolume level, hypoxic and metabolically active subvolumes showed an overlap of 53 ± 36 %. Overlap between hypoxic sub-volumes and those with high blood flow and blood volume was smaller: 15 ± 17 % and 28 ± 28 %, respectively. Half of the patients showed a spatial mismatch (overlap <5 %) between increased blood flow and hypoxia. The biological imaging features defined in NSCLC tumours showed large interpatient and intratumour variability. There was overlap between hypoxic and metabolically active subvolumes in the majority of tumours, there was spatial mismatch between regions with high blood flow and those with increased hypoxia. (orig.)

  16. Epithelial and Mesenchymal Tumor Compartments Exhibit In Vivo Complementary Patterns of Vascular Perfusion and Glucose Metabolism

    Directory of Open Access Journals (Sweden)

    Mirco Galiè

    2007-11-01

    Full Text Available Glucose transport and consumption are increased in tumors, and this is considered a diagnostic index of malignancy. However, there is recent evidence that carcinoma-associated stromal cells are capable of aerobic metabolism with low glucose consumption, at least partly because of their efficient vascular supply. In the present study, using dynamic contrast-enhanced magnetic resonance imaging and [F-18]fluorodeoxyglucose (FDG positron emission tomography (PET, we mapped in vivo the vascular supply and glucose metabolism in syngeneic experimental models of carcinoma and mesenchymal tumor. We found that in both tumor histotypes, regions with high vascular perfusion exhibited a significantly lower FDG uptake. This reciprocity was more conspicuous in carcinomas than in mesenchymal tumors, and regions with a high-vascular/low-FDG uptake pattern roughly overlapped with a stromal capsule and intratumoral large connectival septa. Accordingly, mesenchymal tumors exhibited a higher vascular perfusion and a lower FDG uptake than carcinomas. Thus, we provide in vivo evidence of vascular/metabolic reciprocity between epithelial and mesenchymal histotypes in tumors, suggesting a new intriguing aspect of epithelial-stromal interaction. Our results suggests that FDG-PET-based clinical analysis can underestimate the malignity or tumor extension of carcinomas exhibiting any trait of “mesenchymalization” such as desmoplasia or epithelial-mesenchymal transition.

  17. Metabolism of ibuprofen in higher plants: A model Arabidopsis thaliana cell suspension culture system

    Czech Academy of Sciences Publication Activity Database

    Maršík, Petr; Šíša, Miroslav; Lacina, O.; Moťková, Kateřina; Langhansová, Lenka; Rezek, Jan; Vaněk, Tomáš

    2017-01-01

    Roč. 220, JAN (2017), s. 383-392 ISSN 0269-7491 R&D Projects: GA ČR(CZ) GA14-22593S Grant - others:European Regional Development Fund(XE) CZ.2.16/3.1.00/24014 Institutional support: RVO:61389030 Keywords : Arabidopsis thaliana * Ibuprofen * Metabolism * Plant cells * Sequestration Subject RIV: CE - Biochemistry OBOR OECD: Plant sciences, botany Impact factor: 5.099, year: 2016

  18. Size, Shape, and Arrangement of Cellulose Microfibril in Higher Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Ding, S. Y.

    2013-01-01

    Plant cell walls from maize (Zea mays L.) are imaged using atomic force microscopy (AFM) at the sub-nanometer resolution. We found that the size and shape of fundamental cellulose elementary fibril (CEF) is essentially identical in different cell wall types, i.e., primary wall (PW), parenchyma secondary wall (pSW), and sclerenchyma secondary wall (sSW), which is consistent with previously proposed 36-chain model (Ding et al., 2006, J. Agric. Food Chem.). The arrangement of individual CEFs in these wall types exhibits two orientations. In PW, CEFs are horizontally associated through their hydrophilic faces, and the planar faces are exposed, forming ribbon-like macrofibrils. In pSW and sSW, CEFs are vertically oriented, forming layers, in which hemicelluloses are interacted with the hydrophobic faces of the CEF and serve as spacers between CEFs. Lignification occurs between CEF-hemicelluloses layers in secondary walls. Furthermore, we demonstrated quantitative analysis of plant cell wall accessibility to and digestibility by different cellulase systems at real-time using chemical imaging (e.g., stimulated Raman scattering) and fluorescence microscopy of labeled cellulases (Ding et al., 2012, Science, in press).

  19. Normal versus sickle red blood cells: hemodynamic and permeability characteristics in reperfusion lung injury.

    Science.gov (United States)

    Haynes, J; Seibert, A; Shah, A; Taylor, A

    1990-01-01

    Decreased deformability and increased internal viscosity of the sickle red blood cell (SRBC) contribute to abnormal flow in the microcirculation. Since the lungs are commonly affected in sickle cell disease, we compared the hemodynamics of the normal human red blood cell (NRBC) with the SRBC in the pulmonary circulation. The SRBC has decreased antioxidant enzyme activities compared with the NRBC. Thus, using the capillary filtration coefficient (Kfc), we determined the ability of the NRBC and the SRBC to attenuate the increased permeability and resulting edema seen in the oxidant stress of reperfusion lung injury (RLI). We found that lungs perfused with a 5% SRBC perfusate had higher pulmonary arterial pressures (Ppa) and resistances than lungs perfused with a 5% NRBC perfusate. Lungs made ischemic and reperfused with a physiologic cell-free perfusate resulted in a significant increase (P less than .05) in Kfc compared with the preischemic Kfc (.45 +/- .06 to 1.4 +/- 22 mL.min-1.cm H2O.100 g-1). In lungs reperfused with 5% RBC-containing perfusates, the Kfc did not change from preischemic Kfc with NRBCs and decreased from the preischemic Kfc with SRBCs. These findings suggest that the SRBC causes physiologically significant increases in Ppa and resistances and the SRBC, like the NRBC, offers apparent protection in RLI.

  20. Field profile and loading measurements on higher order modes in a two cell 500 MHz superconducting structure

    International Nuclear Information System (INIS)

    Barry, W.; Edighoffer, J.; Chattopadhyay, S.; Fornaco, S.

    1992-01-01

    The Infrared Free Electron Laser, being designed at LBL as part of the Chemical Dynamics Research Laboratory, is based on a 500 MHz superconducting linac driver that consists of five 4-cell structures of the CERN/DESY type. A 500 MHz, 2-cell version of this structure is being used in a joint Stanford/LBL/BNL program to study accelerator issues relevant to the FEL applications. As part of this study, field profile and loading measurements of higher order modes have been made on the prototype structure. (Author) 3 refs., 2 figs., tab

  1. Field profile and loading measurements on higher order modes in a two cell 500 MHz superconducting structure

    International Nuclear Information System (INIS)

    Barry, W.; Edighoffer, J.; Chattopadhyay, S.; Fornaca, S.

    1992-08-01

    The Infrared Free Electron Laser, being designed at LBL as part of the Chemical Dynamics Research Laboratory, is based on a 500 MHz superconducting linac driver that consists of five 4-cell structures of the CERN/DESY type. A 500 MHz, 2-cell version of this structure is being used in a joint Stanford/LBL/BNL program to study accelerator issues relevant to the FEL applications. As part of this study, field profile and loading measurements of higher order modes have been made on the prototype structure

  2. Quality assessment of a placental perfusion protocol

    DEFF Research Database (Denmark)

    Mathiesen, Line; Mose, Tina; Mørck, Thit Juul

    2010-01-01

    mlh(-1) from the fetal reservoir) when adding 2 (n=7) and 20mg (n=9) FITC-dextran/100ml fetal perfusion media. Success rate of the Copenhagen placental perfusions is provided in this study, including considerations and quality control parameters. Three checkpoints suggested to determine success rate...

  3. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S. [Samsung Medical Center, Seoul (Korea, Republic of); Lee, Kyung Han; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1996-03-15

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  4. Computed Tomography (CT) Perfusion in Abdominal Cancer

    DEFF Research Database (Denmark)

    Hansen, Martin Lundsgaard; Norling, Rikke; Lauridsen, Carsten

    2013-01-01

    Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed...

  5. Clinical application of cerebral dynamic perfusion studies

    International Nuclear Information System (INIS)

    DeLand, F.H.

    1975-01-01

    Radionuclide cerebral perfusion studies are assuming a far greater importance in the detection and differential diagnosis of cerebral lesions. Perfusion studies not only contribute to the differential diagnosis of lesions but in certain cases are the preferred methods by which more accurate clinical interpretations can be made. The characteristic blood flow of arterio-venous malformations readily differentiates this lesion from neoplasms. The decreased perfusion or absent perfusion observed in cerebral infarctions is diagnostic without concurrent evidence from static images. Changes in rates and direction of blood flow contribute fundamental information to the status of stenosis and vascular occlusion and, in addition, offer valuable information on the competency and routes of collateral circulation. The degree of cerebral perfusion after cerebral vascular accidents appears to be directly related to patient recovery, particularly muscular function. Cerebral perfusion adds a new parameter in the diagnosis of subdural haematomas and concussion and in the differentiation of obscuring radioactivity from superficial trauma. Although pictorial displays of perfusion blood flow will offer information in most cerebral vascular problems, the addition of computer analysis better defines temporal relationships of regional blood flow, quantitative changes in flow and the detection of the more subtle increases or decreases in cerebral blood flow. The status of radionuclide cerebral perfusion studies has taken on an importance making it the primary modality for the diagnosis of cerebral lesions. (author)

  6. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    radiolabeled liquid aerosols are not restricted to the presence of obstructive lung disease. Radiolabeled macroaggregated human albumin is the imaging agent of choice for perfusion scintigraphy. An optimal combination of nuclide activities and acquisition times for ventilation and perfusion, collimators......Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas over......, and imaging matrix yields an adequate V/Q SPECT study in approximately 20 minutes of imaging time. The recommended protocol based on the patient remaining in an unchanged position during the initial ventilation study and the perfusion study allows presentation of matching ventilation and perfusion slices...

  7. Assessment of the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level in patients with emphysema

    International Nuclear Information System (INIS)

    Ley-Zaporozhan, Julia; Ley, Sebastian; Eberhardt, Ralf; Weinheimer, Oliver; Fink, Christian; Puderbach, Michael; Eichinger, Monika; Herth, Felix; Kauczor, Hans-Ulrich

    2007-01-01

    Purpose: To assess the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level using CT and MRI in patients with emphysema. Material and methods: Forty-five patients with severe emphysema (GOLD III and IV) underwent inspiratory 3D-HRCT and contrast-enhanced MR-perfusion (1.5T; 3.5 mm x 1.9 mm x 4 mm). 3D-HRCT data was analyzed using a software for detection and visualization of emphysema. Emphysema was categorized in four clusters with different volumes and presented as overlay on the CT. CT and lung perfusion were visually analyzed for three lobes on each side using a four-point-score to grade the abnormalities on CT (1: predominantly small emphysema-clusters to 4: >75% large emphysema-clusters) and MRI (1: normal perfusion to 4: no perfusion). Results: A total of 270 lobes were evaluated. At CT, the score was 1 for 9 lobes, 2 for 43, 3 for 77, and 4 for 141 lobes. At MRI, the score was 1 for 13 lobes, 2 for 45, 3 for 92, and 4 for 120 lobes. Matching of lung parenchymal destruction and reduced perfusion was found in 213 lobes (weighted kappa = 0.8). The score was higher on CT in 44, and higher on MRI in 13 lobes. Conclusion: 3D-HRCT and 3D MR-perfusion show a high lobar agreement between parenchymal destruction and reduction of perfusion in patients with severe emphysema

  8. Perfusion of tumor-bearing kidneys as a model for scintigraphic screening of monoclonal antibodies

    International Nuclear Information System (INIS)

    van Dijk, J.; Oosterwijk, E.; van Kroonenburgh, M.J.; Jonas, U.; Fleuren, G.J.; Pauwels, E.K.; Warnaar, S.O.

    1988-01-01

    Tumor-bearing human kidneys were used in an ex vivo perfusion model to screen monoclonal antibodies, recognizing renal cell carcinoma-associated antigens for diagnostic potential in vivo. Perfusion of tumor-bearing kidneys with /sup 99m/Tc-labeled G250 and RC38 antibody resulted in visualization of the tumor, whereas perfusion with two other monoclonal antibodies, RC2 and RC4, did not lead to tumor visualization. Uptake of radiolabel in normal kidney tissue was low for G250 and RC38 antibody. Tumor-to-kidney tissue ratios after perfusion with G250 and RC38 antibody were 2.7 and 2.2, respectively. After rinsing for 3 hr with unlabeled perfusion fluid the tumor-to-kidney tissue ratios increased to 8.6 for G250 antibody and to 2.7 for RC38 antibody. We conclude that perfusion of tumor-bearing human kidneys with radiolabeled monoclonal antibodies is a relatively simple way to evaluate renal cell carcinoma associated monoclonal antibodies as diagnostic agents in vivo

  9. Adjuvant therapy in renal cell carcinoma: does higher risk for recurrence improve the chance for success?

    Science.gov (United States)

    Figlin, R A; Leibovich, B C; Stewart, G D; Negrier, S

    2018-02-01

    The success of targeted therapies, including inhibitors of the vascular endothelial growth factor pathway or the mammalian target of rapamycin, in the treatment of metastatic renal cell carcinoma led to interest in testing their efficacy in the adjuvant setting. Results from the first trials are now available, with other studies due to report imminently. This review provides an overview of adjuvant targeted therapy in renal cell carcinoma, including interpretation of currently available conflicting data and future direction of research. We discuss the key differences between the completed targeted therapy adjuvant trials, and highlight the importance of accurately identifying patients who are likely to benefit from adjuvant treatment. We also consider reasons why blinded independent radiology review and treatment dose may prove critical for adjuvant treatment success. The implications of using disease-free survival as a surrogate end point for overall survival from the patient perspective and measurement of health benefit have recently been brought into focus and are discussed. Finally, we discuss how the ongoing adjuvant trials with targeted therapies and checkpoint inhibitors may improve our understanding and ability to prevent tumor recurrence after nephrectomy in the future.

  10. Higher-Density Culture in Human Embryonic Stem Cells Results in DNA Damage and Genome Instability

    Directory of Open Access Journals (Sweden)

    Kurt Jacobs

    2016-03-01

    Full Text Available Human embryonic stem cells (hESC show great promise for clinical and research applications, but their well-known proneness to genomic instability hampers the development to their full potential. Here, we demonstrate that medium acidification linked to culture density is the main cause of DNA damage and genomic alterations in hESC grown on feeder layers, and this even in the short time span of a single passage. In line with this, we show that increasing the frequency of the medium refreshments minimizes the levels of DNA damage and genetic instability. Also, we show that cells cultured on laminin-521 do not present this increase in DNA damage when grown at high density, although the (long-term impact on their genomic stability remains to be elucidated. Our results explain the high levels of genome instability observed over the years by many laboratories worldwide, and show that the development of optimal culture conditions is key to solving this problem.

  11. Kinetics of reversible-sequestration of leukocytes by the isolated perfused rat lung

    Energy Technology Data Exchange (ETDEWEB)

    Goliaei, B.

    1980-08-01

    The kinetics and morphology of sequestration and margination of rat leukocytes were studied using an isolated perfused and ventilated rat lung preparation. Whole rat blood, bone marrow suspension, or leukocyte suspensions, were used to perfuse the isolated rat lung. The lung was also perfused with latex particle suspensions and the passage of particles through the lung capillaries was studied. When a leukocyte suspension was perfused through the lung in the single-pass mode, the rate of sequestration decreased as more cells were perfused. In contrast, latex particles of a size comparable to that of leukocytes were totally stopped by the lung. When the leukocyte suspension was recirculated through the lung, cells were rapidly removed from circulation until a steady state was reached, after which no net removal of cells by the lung occurred. These results indicate that leukocytes are reversibly sequestered from circulation. The sequestered cells marginated and attached to the luminal surface of the endothelium of post-capillary venules and veins. A mathematical model was developed based on the assumption that the attachment and detachment of leukocytes to blood vessel walls follows first-order kinetics. The model correctly predicts the following characteristics of the system: (a) the kinetics of the sequestration of leukocytes by the lung; (b) the existence of a steady state when a suspension of leukocytes is recirculated through the lung; and (c) the independence of the fraction of cells remaining in circulation from the starting concentration for all values of starting concentration. (ERB)

  12. Brain Perfusion Changes in Intracerebral Hemorrhage

    International Nuclear Information System (INIS)

    Mititelu, R.; Mazilu, C.; Ghita, S.; Rimbu, A.; Marinescu, G.; Codorean, I.; Bajenaru, O.

    2006-01-01

    Full text: Purpose: Despite the latest advances in medical treatment and neuro critical care, patients suffering spontaneous intracerebral hemorrhage (SICH) still have a very poor prognosis, with a greater mortality and larger neurological deficits at the survivors than for ischemic stroke. Many authors have shown that there are many mechanisms involved in the pathology of SICH: edema, ischemia, inflammation, apoptosis. All of these factors are affecting brain tissue surrounding hematoma and are responsible of the progressive neurological deterioration; most of these damages are not revealed by anatomical imaging techniques. The aim of our study was to asses the role of brain perfusion SPECT in demonstrating perfusion changes in SICH patients. Method: 17 SICH pts were studied. All pts underwent same day CT and brain SPECT with 99mTcHMPAO, 24h-5d from onset of stroke. Results: 14/17 pts showed a larger perfusion defect than expected after CT. In 2 pts hematoma diameter was comparable on CT and SPECT; 1pt had quasinormal aspect of SPECT study. In pts with larger defects, SPECT revealed a large cold spot with similar size compared with CT, and a surrounding hypo perfused area. 6/17 pts revealed cortical hyper perfusion adjacent to hypo perfused area and corresponding to a normal-appearing brain tissue on CT. In 3 pts we found crossed cerebellar diaskisis.In 2 pts we found cortical hypo perfused area in the contralateral cortex, with normal appearing brain tissue on CT. Conclusions: Brain perfusion SPECT revealed different types of perfusion changes in the brain tissue surrounding hematoma. These areas contain viable brain tissue that may be a target for future ne uroprotective strategies. Further studies are definitely required to demonstrate prognostic significance of these changes, but we can conclude that brain perfusion SPECT can play an important role in SICH, by early demonstrating functional changes responsible of clinical deterioration, thus allowing prompt

  13. Higher molecular weight polyethylene glycol increases cell proliferation while improving barrier function in an in vitro colon cancer model.

    Science.gov (United States)

    Bharadwaj, Shruthi; Vishnubhotla, Ramana; Shan, Sun; Chauhan, Chinmay; Cho, Michael; Glover, Sarah C

    2011-01-01

    Polyethylene glycol (PEG) has been previously shown to protect against enteric pathogens and prevent colon cancer invasion. To determine if PEG could indeed protect against previously observed pro-invasive effects of commensal E. coli and EPEC, Caco-2 cells grown in an in vitro model of colon cancer were infected with strains of human commensal E. coli or EPEC and treated with 10% PEG 3350, PEG 8000, and PEG 20,000, respectively. At 24 hours after infection, MMP-1 and MMP-13 activities, cell cluster thickness, depth of invasion, and proliferation were determined using standard molecular biology techniques and advanced imaging. We found that higher molecular weight PEG, especially PEG 8000 and 20,000, regardless of bacterial infection, increased proliferation and depth of invasion although a decrease in cellular density and MMP-1 activity was also noted. Maximum proliferation and depth of invasion of Caco-2 cells was observed in scaffolds treated with a combination of commensal E. coli strain, HS4 and PEG 8000. In conclusion, we found that PEG 8000 increased cell proliferation and led to the preservation of cell density in cells treated with commensal bacteria. This is important, because the preservation of a proliferative response in colon cancer results in a more chemo-responsive tumor.

  14. Higher Molecular Weight Polyethylene Glycol Increases Cell Proliferation While Improving Barrier Function in an In Vitro Colon Cancer Model

    Directory of Open Access Journals (Sweden)

    Shruthi Bharadwaj

    2011-01-01

    Full Text Available Polyethylene glycol (PEG has been previously shown to protect against enteric pathogens and prevent colon cancer invasion. To determine if PEG could indeed protect against previously observed pro-invasive effects of commensal E. coli and EPEC, Caco-2 cells grown in an in vitro model of colon cancer were infected with strains of human commensal E. coli or EPEC and treated with 10% PEG 3350, PEG 8000, and PEG 20,000, respectively. At 24 hours after infection, MMP-1 and MMP-13 activities, cell cluster thickness, depth of invasion, and proliferation were determined using standard molecular biology techniques and advanced imaging. We found that higher molecular weight PEG, especially PEG 8000 and 20,000, regardless of bacterial infection, increased proliferation and depth of invasion although a decrease in cellular density and MMP-1 activity was also noted. Maximum proliferation and depth of invasion of Caco-2 cells was observed in scaffolds treated with a combination of commensal E. coli strain, HS4 and PEG 8000. In conclusion, we found that PEG 8000 increased cell proliferation and led to the preservation of cell density in cells treated with commensal bacteria. This is important, because the preservation of a proliferative response in colon cancer results in a more chemo-responsive tumor.

  15. Distinct Signaling Pathways After Higher or Lower Doses of Radiation in Three Closely Related Human Lymphoblast Cell Lines

    International Nuclear Information System (INIS)

    Lu, T.-P.; Lai, L.-C.; Lin, B.-I.; Chen, L.-H.; Hsiao, T.-H.; Liber, Howard L.; Cook, John A.; Mitchell, James B.; Tsai, M.-H.; Chuang, Eric Y.

    2010-01-01

    Purpose: The tumor suppressor p53 plays an essential role in cellular responses to DNA damage caused by ionizing radiation; therefore, this study aims to further explore the role that p53 plays at different doses of radiation. Materials and Methods: The global cellular responses to higher-dose (10 Gy) and lower dose (iso-survival dose, i.e., the respective D0 levels) radiation were analyzed using microarrays in three human lymphoblast cell lines with different p53 status: TK6 (wild-type p53), NH32 (p53-null), and WTK1 (mutant p53). Total RNAs were extracted from cells harvested at 0, 1, 3, 6, 9, and 24 h after higher and lower dose radiation exposures. Template-based clustering, hierarchical clustering, and principle component analysis were applied to examine the transcriptional profiles. Results: Differential expression profiles between 10 Gy and iso-survival radiation in cells with different p53 status were observed. Moreover, distinct gene expression patterns were exhibited among these three cells after 10 Gy radiation treatment, but similar transcriptional responses were observed in TK6 and NH32 cells treated with iso-survival radiation. Conclusions: After 10 Gy radiation exposure, the p53 signaling pathway played an important role in TK6, whereas the NFkB signaling pathway appeared to replace the role of p53 in WTK1. In contrast, after iso-survival radiation treatment, E2F4 seemed to play a dominant role independent of p53 status. This study dissected the impacts of p53, NFkB and E2F4 in response to higher or lower doses of γ-irradiation.

  16. Comparison of higher order modes damping techniques for 800 MHz single cell superconducting cavities

    Science.gov (United States)

    Shashkov, Ya. V.; Sobenin, N. P.; Petrushina, I. I.; Zobov, M. M.

    2014-12-01

    At present, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOMs) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOMs damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOMs damping is analyzed. The problems of a multipacting discharge in the considered structures are discussed and the operating frequency detuning due to the Lorentz force is evaluated.

  17. Comparison of higher order modes damping techniques for 800 MHz single cell superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Shashkov, Ya.V., E-mail: shashkovyv@mail.ru [National Research Nuclear University MEPhI, Moscow (Russian Federation); Sobenin, N.P.; Petrushina, I.I. [National Research Nuclear University MEPhI, Moscow (Russian Federation); Zobov, M.M. [Laboratori Nazionali di Frascati INFN, Rome (Italy)

    2014-12-11

    At present, applications of 800 MHz harmonic cavities in both bunch lengthening and shortening regimes are under consideration and discussion in the framework of the High Luminosity LHC project. In this paper we study electromagnetic characteristics of high order modes (HOMs) for a single cell 800 MHz superconducting cavity and arrays of such cavities connected by drifts tubes. Different techniques for the HOMs damping such as beam pipe grooves, coaxial-notch loads, fluted beam pipes etc. are investigated and compared. The influence of the sizes and geometry of the drift tubes on the HOMs damping is analyzed. The problems of a multipacting discharge in the considered structures are discussed and the operating frequency detuning due to the Lorentz force is evaluated.

  18. FinFET memory cell improvements for higher immunity against single event upsets

    Science.gov (United States)

    Sajit, Ahmed Sattar

    The 21st century is witnessing a tremendous demand for transistors. Life amenities have incorporated the transistor in every aspect of daily life, ranging from toys to rocket science. Day by day, scaling down the transistor is becoming an imperious necessity. However, it is not a straightforward process; instead, it faces overwhelming challenges. Due to these scaling changes, new technologies, such as FinFETs for example, have emerged as alternatives to the conventional bulk-CMOS technology. FinFET has more control over the channel, therefore, leakage current is reduced. FinFET could bridge the gap between silicon devices and non-silicon devices. The semiconductor industry is now incorporating FinFETs in systems and subsystems. For example, Intel has been using them in their newest processors, delivering potential saving powers and increased speeds to memory circuits. Memory sub-systems are considered a vital component in the digital era. In memory, few rows are read or written at a time, while the most rows are static; hence, reducing leakage current increases the performance. However, as a transistor shrinks, it becomes more vulnerable to the effects from radioactive particle strikes. If a particle hits a node in a memory cell, the content might flip; consequently, leading to corrupting stored data. Critical fields, such as medical and aerospace, where there are no second chances and cannot even afford to operate at 99.99% accuracy, has induced me to find a rigid circuit in a radiated working environment. This research focuses on a wide spectrum of memories such as 6T SRAM, 8T SRAM, and DICE memory cells using FinFET technology and finding the best platform in terms of Read and Write delay, susceptibility level of SNM, RSNM, leakage current, energy consumption, and Single Event Upsets (SEUs). This research has shown that the SEU tolerance that 6T and 8T FinFET SRAMs provide may not be acceptable in medical and aerospace applications where there is a very high

  19. Lower omental t-regulatory cell count is associated with higher fasting glucose and lower β-cell function in adults with obesity.

    Science.gov (United States)

    Gyllenhammer, Lauren E; Lam, Jonathan; Alderete, Tanya L; Allayee, Hooman; Akbari, Omid; Katkhouda, Namir; Goran, Michael I

    2016-06-01

    T-lymphocytes are potential initiators and regulators of adipose tissue (AT) inflammation, but there is limited human data on omental AT. The aim of this study was to assess the relationship between T cells, particularly Foxp3+ regulatory T (Treg) cells, in human subcutaneous (subQ) and omental AT and type 2 diabetes risk. SubQ and deep subQ (DsubQ) abdominal and omental AT biopsies were collected from 44 patients (body mass index, BMI ≥25) undergoing elective abdominal surgery. Flow cytometry was used to quantify CD4+ T cell (T effector and Treg) and macrophages (M1 and M2), and systemic inflammation was measured in fasting blood. Tregs were significantly lower in omental versus subQ and DsubQ AT, and M1 cell counts were significantly higher in the omental and DsubQ depot relative to the subQ. Only omental AT Tregs were negatively associated with fasting glucose and MCP-1 and positively associated with homeostasis model assessment (HOMA)-β. M1 and M2 cell counts across multiple depots had significant relationships with HOMA-insulin resistance, tumor necrosis factor-α, insulin, and HOMA-β. All relationships were consistent across ethnicities. Tregs were significantly lower in omental versus both subQ adipose depots. Fewer omental Tregs may have metabolic implications based on depot-specific relationships with higher fasting glucose and lower β-cell function. © 2016 The Obesity Society.

  20. Should elderly patients with higher-risk myelodysplastic syndromes undergo allogeneic hematopoietic stem cell transplantation?

    Science.gov (United States)

    Zeidan, Amer M; Gore, Steven D

    2013-10-01

    Myelodysplastic syndromes (MDS) include a group of hematopoietic malignancies characterized by dysplastic changes, ineffective hematopoiesis and variable risk of leukemic progression. At diagnosis, 86% of MDS patients are ≥60 years. Azacitidine, the only drug that prolongs life in high-risk (HR)-MDS patients, adds a median of only 9.5 months to life. Allogeneic stem cell transplantation (alloSCT) remains the only potentially curative approach. Despite recent improvements including use of reduced intensity conditioning (RIC) that decrease transplant-related mortality, alloSCT continues to be used rarely in elderly MDS. There is paucity of data regarding outcomes of RIC alloSCT in elderly MDS patients, especially in direct comparison with azanucleosides. In this paper, the authors discuss the recent Markov decision analysis by Koreth et al. in which investigators demonstrated superior survival of patients with HR-MDS aged 60-70 years who underwent RIC alloSCT in comparison with those who were treated with azanucleosides.

  1. CD3+/CD16+CD56+ cell numbers in peripheral blood are correlated with higher tumor burden in patients with diffuse large B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Anna Twardosz

    2011-04-01

    Full Text Available Diffuse large B-cell lymphoma is the commonest histological type of malignant lymphoma, andremains incurable in many cases. Developing more efficient immunotherapy strategies will require betterunderstanding of the disorders of immune responses in cancer patients. NKT (natural killer-like T cells wereoriginally described as a unique population of T cells with the co-expression of NK cell markers. Apart fromtheir role in protecting against microbial pathogens and controlling autoimmune diseases, NKT cells havebeen recently revealed as one of the key players in the immune responses against tumors. The objective of thisstudy was to evaluate the frequency of CD3+/CD16+CD56+ cells in the peripheral blood of 28 diffuse largeB-cell lymphoma (DLBCL patients in correlation with clinical and laboratory parameters. Median percentagesof CD3+/CD16+CD56+ were significantly lower in patients with DLBCL compared to healthy donors(7.37% vs. 9.01%, p = 0.01; 4.60% vs. 5.81%, p = 0.03, although there were no differences in absolute counts.The frequency and the absolute numbers of CD3+/CD16+CD56+ cells were lower in advanced clinical stagesthan in earlier ones. The median percentage of CD3+/CD16+CD56+ cells in patients in Ann Arbor stages 1–2 was5.55% vs. 3.15% in stages 3–4 (p = 0.02, with median absolute counts respectively 0.26 G/L vs. 0.41 G/L (p == 0.02. The percentage and absolute numbers of CD3+/CD16+CD56+ cells were significantly higher in DL-BCL patients without B-symptoms compared to the patients with B-symptoms, (5.51% vs. 2.46%, p = 0.04;0.21 G/L vs. 0.44 G/L, p = 0.04. The percentage of CD3+/CD16+CD56+ cells correlated adversely with serumlactate dehydrogenase (R= –445; p < 0.05 which might influence NKT count. These figures suggest a relationshipbetween higher tumor burden and more aggressive disease and decreased NKT numbers. But it remains tobe explained whether low NKT cell counts in the peripheral blood of patients with DLBCL are the result

  2. Vasoactive mediators and splanchnic perfusion.

    Science.gov (United States)

    Reilly, P M; Bulkley, G B

    1993-02-01

    To provide an overview of the splanchnic hemodynamic response to circulatory shock. Previous studies performed in our own laboratory, as well as a computer-assisted search of the English language literature (MEDLINE, 1966 to 1991), followed by a selective review of pertinent articles. Studies were selected that demonstrated relevance to the splanchnic hemodynamic response to circulatory shock, either by investigating the pathophysiology or documenting the sequelae. Article selection included clinical studies as well as studies in appropriate animal models. Pertinent data were abstracted from the cited articles. The splanchnic hemodynamic response to circulatory shock is characterized by a selective vasoconstriction of the mesenteric vasculature mediated largely by the renin-angiotensin axis. This vasospasm, while providing a natural selective advantage to the organism in mild-to-moderate shock (preserving relative perfusion of the heart, kidneys, and brain), may, in more severe shock, cause consequent loss of the gut epithelial barrier, or even hemorrhagic gastritis, ischemic colitis, or ischemic hepatitis. From a physiologic standpoint, nonpulsatile cardiopulmonary bypass, a controlled form of circulatory shock, has been found experimentally to significantly increase circulating levels of angiotensin II, the hormone responsible for this selective splanchnic vasoconstriction. While angiotensin II has been viewed primarily as the mediator responsible for the increased total vascular resistance seen during (and after) cardiopulmonary bypass, it may also cause the disproportionate decrease in mesenteric perfusion, as measured in human subjects by intraluminal gastric tonometry and galactose clearance by the liver, as well as the consequent development of the multiple organ failure syndrome seen in 1% to 5% of patients after cardiac surgery.

  3. Regional Cerebral Perfusion in Progressive Supranuclear Palsy

    International Nuclear Information System (INIS)

    Lee, Won Yong; Lee, Ki Hyeong; Yoon, Byung Woo; Lee, Sang Bok; Jeon, Beom S.; Lee, Kyung Han; Lee, Myung Chul

    1996-01-01

    Progressive supranuclear palsy (PSP) is a Parkinson-plus syndrome characterized clinically by supranuclear ophthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormaility and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using Tc-99m-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p 0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex

  4. Computerized analysis of brain perfusion parameter images

    International Nuclear Information System (INIS)

    Turowski, B.; Haenggi, D.; Wittsack, H.J.; Beck, A.; Aurich, V.

    2007-01-01

    Purpose: The development of a computerized method which allows a direct quantitative comparison of perfusion parameters. The display should allow a clear direct comparison of brain perfusion parameters in different vascular territories and over the course of time. The analysis is intended to be the basis for further evaluation of cerebral vasospasm after subarachnoid hemorrhage (SAH). The method should permit early diagnosis of cerebral vasospasm. Materials and Methods: The Angiotux 2D-ECCET software was developed with a close cooperation between computer scientists and clinicians. Starting from parameter images of brain perfusion, the cortex was marked, segmented and assigned to definite vascular territories. The underlying values were averages for each segment and were displayed in a graph. If a follow-up was available, the mean values of the perfusion parameters were displayed in relation to time. The method was developed under consideration of CT perfusion values but is applicable for other methods of perfusion imaging. Results: Computerized analysis of brain perfusion parameter images allows an immediate comparison of these parameters and follow-up of mean values in a clear and concise manner. Values are related to definite vascular territories. The tabular output facilitates further statistic evaluations. The computerized analysis is precisely reproducible, i. e., repetitions result in exactly the same output. (orig.)

  5. Effects of perfusion pressure and insulin on (3H) cytochalasin B (CB) binding to control and diabetic rat hearts

    International Nuclear Information System (INIS)

    Pleta, M.; Chan, T.

    1987-01-01

    Using ( 3 H) CB, they attempted to quantitate the changes in the amount of glucose transporters in the plasma membrane (PM) and intracellular membranes (HSP) prepared from rat hearts perfused with insulin, under low and high pressure. Membranes isolated from non-perfused hearts showed a PM/HSP ratio of (0.593). Hearts perfused with low pressure showed a lower ratio of (0.474). Perfusion with insulin increased the ratio to (1.8), almost a 3-4 fold increase from low perfusion pressure. These data correlate with insulin effects in glucose transport and CB binding in the fat cells. High pressure perfusion increased the PM/HSP ratio by 1-2 fold. ( 3 H) 2-DG transport indicates a comparable increase in glucose uptake with high pressure, but with insulin only a 1.5 fold increase was observed. Initial data obtained from streptozotocin (STZ) injected diabetic rats indicate low CB binding in the PM fraction. Only insulin, but not high perfusion pressure increased PM/HSP ratio in the STZ-diabetic hearts. Their data imply that while both caused apparent translocation of glucose transporters, influences on cardiac glucose metabolism by work load are different. Furthermore, STZ induced diabetes affected only the high perfusion pressure-induced and not the insulin-stimulated change in CB binding

  6. Dynamic contrast enhanced MRI for perfusion quantification

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke

    2002-01-01

    Magnetic resonance imaging, during bolus passage of a paramagnetic contrast agent, is used world-wide to obtain parameters that reflect the pathological state of tissue. Abnormal perfusion occurs in diseases such as stoke and tumour. Consequently, perfusion quantication could have signi cant...... clinical value both in diagnosis and treatment of such pathologies. One approach for perfusion quanti cation involves using the contrast mechanism that a ects the transverse relaxation rates of the magnetization, R2 or R 2 , since this provides the most pronounced effect. However, the linearity between...

  7. WE-AB-202-12: Voxel-Wise Analysis of Apparent Diffusion Coefficient and Perfusion Maps in Multi-Parametric MRI of Prostate Cancer

    International Nuclear Information System (INIS)

    Engstroem, K; Casares-Magaz, O; Muren, L; Roervik, J; Andersen, E

    2016-01-01

    Purpose: Multi-parametric MRI (mp-MRI) is being introduced in radiotherapy (RT) of prostate cancer, including for tumour delineation in focal boosting strategies. We recently developed an image-based tumour control probability model, based on cell density distributions derived from apparent diffusion coefficient (ADC) maps. Beyond tumour volume and cell densities, tumour hypoxia is also an important determinant of RT response. Since tissue perfusion from mp-MRI has been related to hypoxia we have explored the patterns of ADC and perfusion maps, and the relations between them, inside and outside prostate index lesions. Methods: ADC and perfusion maps from 20 prostate cancer patients were used, with the prostate and index lesion delineated by a dedicated uro-radiologist. To reduce noise, the maps were averaged over a 3×3×3 voxel cube. Associations between different ADC and perfusion histogram parameters within the prostate, inside and outside the index lesion, were evaluated with the Pearson’s correlation coefficient. In the voxel-wise analysis, scatter plots of ADC vs perfusion were analysed for voxels in the prostate, inside and outside of the index lesion, again with the associations quantified with the Pearson’s correlation coefficient. Results: Overall ADC was lower inside the index lesion than in the normal prostate as opposed to ktrans that was higher inside the index lesion than outside. In the histogram analysis, the minimum ktrans was significantly correlated with the maximum ADC (Pearson=0.47; p=0.03). At the voxel level, 15 of the 20 cases had a statistically significant inverse correlation between ADC and perfusion inside the index lesion; ten of the cases had a Pearson < −0.4. Conclusion: The minimum value of ktrans across the tumour was correlated to the maximum ADC. However, on the voxel level, the ‘local’ ktrans in the index lesion is inversely (i.e. negatively) correlated to the ‘local’ ADC in most patients. Research agreement with

  8. Perfusion-based three dimensional (3D) tissue engineering platform with integrated bioimpedance sensing

    DEFF Research Database (Denmark)

    Muhammad, Haseena Bashir; Canali, Chiara; Heiskanen, Arto

    2014-01-01

    We present an 8-channel bioreactor array with integrated bioimpedance sensors, which enables perfusion culture of cells seeded onto porous 3D scaffolds. Results show the capability of the system for monitoring cell proliferation within the scaffolds through a culture period of 19 days....

  9. Multiple-indicator dilution technique for characterization of normal and retrograde flow in once-through rat liver perfusions

    International Nuclear Information System (INIS)

    St-Pierre, M.V.; Schwab, A.J.; Goresky, C.A.; Lee, W.F.; Pang, K.S.

    1989-01-01

    The technique of normal and retrograde rat liver perfusion has been widely used to probe zonal differences in drug-metabolizing activities. The validity of this approach mandates the same tissue spaces being accessed by substrates during both normal and retrograde perfusions. Using the multiple-indicator dilution technique, we presently examine the extent to which retrograde perfusion alters the spaces accessible to noneliminated references. A bolus dose of 51Cr-labeled red blood cells, 125I-albumin, 14C-sucrose and 3H2O was injected into the portal (normal) or hepatic (retrograde) vein of rat livers perfused at 10 ml per min per liver. The outflow perfusate was serially collected over 220 sec to characterize the transit times and the distribution spaces of the labels. During retrograde perfusion, red blood cells, albumin and sucrose profiles peaked later and lower than during normal perfusion, whereas the water curves were similar. The transit times of red blood cells, albumin and sucrose were longer (p less than 0.005), whereas those for water did not change. Consequently, retrograde flow resulted in significantly larger sinusoidal blood volumes (45%), albumin Disse space (42%) and sucrose Disse space (25%) than during normal flow, whereas the distribution spaces for total and intracellular water remained unaltered. The distension of the vascular tree was confirmed by electron microscopy, by which occasional isolated foci of widened intercellular recesses and spaces of Disse were observed. Cellular ultrastructure was otherwise unchanged, and there was no difference found between normal and retrograde perfusion for bile flow rates, AST release, perfusion pressure, oxygen consumption and metabolic removal of ethanol, a substrate with flow-limited distribution, which equilibrates rapidly with cell water (hepatic extraction ratios were virtually identical: normal vs. retrograde, 0.50 vs. 0.48 at 6 to 7.4 mM input concentration)

  10. Persistent human Borna disease virus infection modifies the acetylome of human oligodendroglia cells towards higher energy and transporter levels

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xia [Shanghai Key Laboratory of Forensic Medicine, Institute of Forensic Science, Ministry of Justice, Shanghai 200063 (China); Liu, Siwen [Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing 400016 (China); Bode, Liv [Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016 (China); Liu, Chengyu [Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing 400016 (China); Zhang, Liang [Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing 400016 (China); Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Wang, Xiao [Institute of Neuroscience and the Collaborative Innovation Center for Brain Science, Chongqing Medical University, Chongqing 400016 (China); Chongqing Key Laboratory of Neurobiology, Chongqing Medical University, Chongqing 400016 (China); Li, Dan [Department of Pathology, Faculty of Basic Medicine, Chongqing Medical University, Chongqing 400016 (China); Lei, Yang [Department of Internal Medicine, University-Town Hospital of Chongqing Medical University, Chongqing 400016 (China); Peng, Xiaojun [Jingjie PTM BioLab (Hangzhou) Co. Ltd, Hangzhou 310018 (China); Cheng, Zhongyi [Advanced Institute of Translational Medicine, Tongji University, Shanghai 200092 (China); and others

    2015-11-15

    Background: Borna disease virus (BDV) is a neurotropic RNA virus persistently infecting mammalian hosts including humans. Lysine acetylation (Kac) is a key protein post-translational modification (PTM). The unexpectedly broad regulatory scope of Kac let us to profile the entire acetylome upon BDV infection. Methods: The acetylome was profiled through stable isotope labeling for cell culture (SILAC)-based quantitative proteomics. The quantifiable proteome was annotated using bioinformatics. Results: We identified and quantified 791 Kac sites in 473 Kac proteins in human BDV Hu-H1-infected and non-infected oligodendroglial (OL) cells. Bioinformatic analysis revealed that BDV infection alters the acetylation of metabolic proteins, membrane-associated proteins and transmembrane transporter activity, and affects the acetylation of several lysine acetyltransferases (KAT). Conclusions: Upon BDV persistence the OL acetylome is manipulated towards higher energy and transporter levels necessary for shuttling BDV proteins to and from nuclear replication sites. - Highlights: • We used SILAC-based proteomics to analyze the acetylome of BDV infected OL cells. • We quantified 791Kac sites in 473 proteins. • Bioinformatic analysis revealed altered acetylation of metabolic proteins et al. • BDV manipulates the OL acetylome towards higher energy and transporter levels. • BDV infection is associated with enriched phosphate-associated metabolic processes.

  11. Persistent human Borna disease virus infection modifies the acetylome of human oligodendroglia cells towards higher energy and transporter levels

    International Nuclear Information System (INIS)

    Liu, Xia; Liu, Siwen; Bode, Liv; Liu, Chengyu; Zhang, Liang; Wang, Xiao; Li, Dan; Lei, Yang; Peng, Xiaojun; Cheng, Zhongyi

    2015-01-01

    Background: Borna disease virus (BDV) is a neurotropic RNA virus persistently infecting mammalian hosts including humans. Lysine acetylation (Kac) is a key protein post-translational modification (PTM). The unexpectedly broad regulatory scope of Kac let us to profile the entire acetylome upon BDV infection. Methods: The acetylome was profiled through stable isotope labeling for cell culture (SILAC)-based quantitative proteomics. The quantifiable proteome was annotated using bioinformatics. Results: We identified and quantified 791 Kac sites in 473 Kac proteins in human BDV Hu-H1-infected and non-infected oligodendroglial (OL) cells. Bioinformatic analysis revealed that BDV infection alters the acetylation of metabolic proteins, membrane-associated proteins and transmembrane transporter activity, and affects the acetylation of several lysine acetyltransferases (KAT). Conclusions: Upon BDV persistence the OL acetylome is manipulated towards higher energy and transporter levels necessary for shuttling BDV proteins to and from nuclear replication sites. - Highlights: • We used SILAC-based proteomics to analyze the acetylome of BDV infected OL cells. • We quantified 791Kac sites in 473 proteins. • Bioinformatic analysis revealed altered acetylation of metabolic proteins et al. • BDV manipulates the OL acetylome towards higher energy and transporter levels. • BDV infection is associated with enriched phosphate-associated metabolic processes.

  12. Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

    International Nuclear Information System (INIS)

    Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela; Maris, Thomas G.

    2008-01-01

    To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22< r<0.32, p<0.05). Our results indicate increased perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

  13. Differences in perfusion parameters between upper and lower lumbar vertebral segments with dynamic contrast-enhanced MRI (DCE MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Savvopoulou, Vasiliki; Vlahos, Lampros; Moulopoulos, Lia Angela [University of Athens, Areteion Hospital, Department of Radiology, Medical School, Athens (Greece); Maris, Thomas G. [University of Crete, Deparment of Medical Physics, Faculty of Medicine, Heraklion (Greece)

    2008-09-15

    To investigate the influence of age, sex and spinal level on perfusion parameters of normal lumbar bone marrow with dynamic contrast-enhanced MRI (DCE MRI). Sixty-seven subjects referred for evaluation of low back pain or sciatica underwent DCE MRI of the lumbar spine. After subtraction of dynamic images, a region of interest (ROI) was placed on each lumbar vertebral body of all subjects, and time intensity curves were generated. Consequently, perfusion parameters were calculated. Statistical analysis was performed to search for perfusion differences among lumbar vertebrae and in relation to age and sex. Upper (L1, L2) and lower (L3, L4, L5) vertebrae showed significant differences in perfusion parameters (p<0.05). Vertebrae of subjects younger than 50 years showed significantly higher perfusion compared to vertebrae of older ones (p<0.05). Vertebrae of females demonstrated significantly increased perfusion compared to those of males of corresponding age (p<0.05). All perfusion parameters, except for washout (WOUT), showed a mild linear correlation with age. Time to maximum slope (TMSP) and time to peak (TTPK) showed the same correlation with sex (0.22perfusion of the upper compared to the lower lumbar spine, of younger compared to older subjects and of females compared to males. (orig.)

  14. Fed-batch and perfusion culture processes: economic, environmental, and operational feasibility under uncertainty.

    Science.gov (United States)

    Pollock, James; Ho, Sa V; Farid, Suzanne S

    2013-01-01

    This article evaluates the current and future potential of batch and continuous cell culture technologies via a case study based on the commercial manufacture of monoclonal antibodies. The case study compares fed-batch culture to two perfusion technologies: spin-filter perfusion and an emerging perfusion technology utilizing alternating tangential flow (ATF) perfusion. The operational, economic, and environmental feasibility of whole bioprocesses based on these systems was evaluated using a prototype dynamic decision-support tool built at UCL encompassing process economics, discrete-event simulation and uncertainty analysis, and combined with a multi-attribute decision-making technique so as to enable a holistic assessment. The strategies were compared across a range of scales and titres so as to visualize how their ranking changes in different industry scenarios. The deterministic analysis indicated that the ATF perfusion strategy has the potential to offer cost of goods savings of 20% when compared to conventional fed-batch manufacturing processes when a fivefold increase in maximum viable cell densities was assumed. Savings were also seen when the ATF cell density dropped to a threefold increase over the fed-batch strategy for most combinations of titres and production scales. In contrast, the fed-batch strategy performed better in terms of environmental sustainability with a lower water and consumable usage profile. The impact of uncertainty and failure rates on the feasibility of the strategies was explored using Monte Carlo simulation. The risk analysis results demonstrated the enhanced robustness of the fed-batch process but also highlighted that the ATF process was still the most cost-effective option even under uncertainty. The multi-attribute decision-making analysis provided insight into the limited use of spin-filter perfusion strategies in industry. The resulting sensitivity spider plots enabled identification of the critical ratio of weightings of

  15. Experimental study of CT perfusion in hepatitis, hepatic fibrosis and early stage of cirrhosis

    International Nuclear Information System (INIS)

    Guan Sheng; Zhao Weidong; Zhou Kangrong; Peng Weijun; Mao Jian; Tang Feng; Wang Yong; Cao Guang; Sun Fei

    2005-01-01

    Objective: To investigate the value of CT perfusion in the early diagnosis of hepatic diffuse disease. Methods: Fourteen male Wistar rats of control group and 14 of test group at stages of hepatitis, hepatic fibrosis, hepatic cirrhosis which were induced with diethylnitrosamine (DEN), were studied with CT perfusion respectively. CT perfusion data of different stages were compared and pathologic analysis were performed. Results: Density-time curves of CT perfusion were satisfactory and all perfusion data could be obtained. During the period of hepatitis developing into early stage of hepatic cirrhosis, hepatic artery flow (HAF) trended to increase in test group, mean transmit time (MTT) prolonged obviously, blood flow (BF) and volume (BV) declined. While in control group, HAF declined slightly, MTT, BV and BF increased. Statistic analysis showed the differences of HAF and MTT at different stages between control and test groups were significant (P<0.05 ); the differences of BV and BF between hepatitis and hepatic cirrhosis, hepatic fibrosis and early stage of hepatic cirrhosis in test group were significant (P<0.05), but no significant difference between hepatitis and hepatic fibrosis. The corresponding pathologic changes at stage of hepatitis was swelling of hepatic cells; sinusoids cap illarization and deposition of collagen in the extravascular Disse's spaces were the main changes relating to hepatic blood perfusion at stage of fibrosis and early stage of cirrhosis. Conclusion: The method of CT scan can reflect some changes of hepatic blood perfusion in rats with hepatitis, hepatic fibrosis and early stage of cirrhosis. The data of CT perfusion, especially the changes should be valuable for clinical early diagnosis, treatment and follow-up. (authors)

  16. A capillary-based perfusion phantom for simulation of brain perfusion for MRI; Ein kapillarbasiertes Phantom zur Simulation der Gehirnperfusion mit der Magnet-Resonanz-Tomografie

    Energy Technology Data Exchange (ETDEWEB)

    Maciak, A.; Kronfeld, A.; Mueller-Forell, W. [Universitaetsklinikum Mainz (Germany). Inst. fuer Neuroradiologie; Wille, C. [Fachhochschule Bingen (Germany). Inst. fuer Informatik; Kempski, O. [Universitaetsklinikum Mainz (Germany). Inst. fuer Neurochirurgische Pathophysiologie; Stoeter, P. [CEDIMAT, Santo Domingo (Dominican Republic). Inst. of Neuroradiology

    2010-10-15

    Purpose: The measurement of the CBF is a non-standardized procedure and there are no reliable gold standards. This abstract shows a capillary-based perfusion-phantom for CE-DSC-MRI. It has equivalent flow properties to those within the tissue capillary system of the human brain and allows the validation of the Siemens Perfusion (MR) software. Materials and Methods: The perfusion phantom consists of a dialyzer for the simulation of the capillary system, a feeding tube for simulation of the AIF and a pulsatile pump for simulation of the heart. Using this perfusion phantom, the exact determination of the gold standard CBF due to the well-known geometry of the phantom is easy. It was validated based on different perfusion measurements. These measurements were investigated with standard software (Siemens Perfusion MR). The software determined the CBF within the capillary system. Based on this CBF, a comparison to the gold standard was made with several different flow speeds. After AIF selection, a total of 726 CBF data points were automatically extracted by the software. Results: This results in a comparison of the gold standard CBF to these 726 CBF values. Therefore, a reproducible and reliable deviation estimation between gold standard CBF and measured CBF using the software was computed. It can be shown that the deviation between gold standard and software-based evaluation ranges between 1 and 31 %. Conclusion: There is no significance for any correlation between flow speed and amount of deviation. The mean measured CBF is 11.4 % higher than the gold standard CBF (p-value < 0.001). Using this kind of perfusion-phantom, the validation of different software systems allows reliable conclusions about their quality. (orig.)

  17. Perfusion-induced changes in cardiac contractility depend on capillary perfusion.

    Science.gov (United States)

    Dijkman, M A; Heslinga, J W; Sipkema, P; Westerhof, N

    1998-02-01

    The perfusion-induced increase in cardiac contractility (Gregg phenomenon) is especially found in heart preparations that lack adequate coronary autoregulation and thus protection of changes in capillary pressure. We determined in the isolated perfused papillary muscle of the rat whether cardiac muscle contractility is related to capillary perfusion. Oxygen availability of this muscle is independent of internal perfusion, and perfusion may be varied or even stopped without loss of function. Muscles contracted isometrically at 27 degrees C (n = 7). During the control state stepwise increases in perfusion pressure resulted in all muscles in a significant increase in active tension. Muscle diameter always increased with increased perfusion pressure, but muscle segment length was unaffected. Capillary perfusion was then obstructed by plastic microspheres (15 microns). Flow, at a perfusion pressure of 66.6 +/- 26.2 cmH2O, reduced from 17.6 +/- 5.4 microliters/min in the control state to 3.2 +/- 1.3 microliters/min after microspheres. Active tension developed by the muscle in the unperfused condition before microspheres and after microspheres did not differ significantly (-12.8 +/- 29.4% change). After microspheres similar perfusion pressure steps as in control never resulted in an increase in active tension. Even at the two highest perfusion pressures (89.1 +/- 28.4 and 106.5 +/- 31.7 cmH2O) that were applied a significant decrease in active tension was found. We conclude that the Gregg phenomenon is related to capillary perfusion.

  18. Effective collateral circulation may indicate improved perfusion territory restoration after carotid endarterectomy.

    Science.gov (United States)

    Lin, Tianye; Lai, Zhichao; Lv, Yuelei; Qu, Jianxun; Zuo, Zhentao; You, Hui; Wu, Bing; Hou, Bo; Liu, Changwei; Feng, Feng

    2018-02-01

    To investigate the relationship between the level of collateral circulation and perfusion territory normalisation after carotid endarterectomy (CEA). This study enrolled 22 patients with severe carotid stenosis that underwent CEA and 54 volunteers without significant carotid stenosis. All patients were scanned with ASL and t-ASL within 1 month before and 1 week after CEA. Collateral circulation was assessed on preoperative ASL images based on the presence of ATA. The postoperative flow territories were considered as back to normal if they conformed to the perfusion territory map in a healthy population. Neuropsychological tests were performed on patients before and within 7 days after surgery. ATA-based collateral score assessed on preoperative ASL was significantly higher in the flow territory normalisation group (n=11, 50 %) after CEA (P mean differences+2SD among control (MMSE=1.35, MOCA=1.02)]. This study demonstrated that effective collateral flow in carotid stenosis patients was associated with normalisation of t-ASL perfusion territory after CEA. The perfusion territory normalisation group tends to have more cognitive improvement after CEA. • Evaluation of collaterals before CEA is helpful for avoiding ischaemia during clamping. • There was good agreement on ATA-based ASL collateral grading. • Perfusion territories in carotid stenosis patients are altered. • Patients have better collateral circulation with perfusion territory back to normal. • MMSE and MOCA test scores improved more in the territory normalisation group.

  19. Quantitation of Brown Adipose Tissue Perfusion in Transgenic Mice Using Near-Infrared Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Akira Nakayama

    2003-01-01

    Full Text Available Brown adipose tissue (BAT; brown fat is the principal site of adaptive thermogenesis in the human newborn and other small mammals. Of paramount importance for thermogenesis is vascular perfusion, which controls the flow of cool blood in, and warmed blood out, of BAT. We have developed an optical method for the quantitative imaging of BAT perfusion in the living, intact animal using the heptamethine indocyanine IR-786 and near-infrared (NIR fluorescent light. We present a detailed analysis of the physical, chemical, and cellular properties of IR-786, its biodistribution and pharmacokinetics, and its uptake into BAT. Using transgenic animals with homozygous deletion of Type II iodothyronine deiodinase, or homozygous deletion of uncoupling proteins (UCPs 1 and 2, we demonstrate that BAT perfusion can be measured noninvasively, accurately, and reproducibly. Using these techniques, we show that UCP 1/2 knockout animals, when compared to wild-type animals, have a higher baseline perfusion of BAT but a similar maximal response to β3-receptor agonist. These results suggest that compensation for UCP deletion is mediated, in part, by the control of BAT perfusion. Taken together, BAT perfusion can now be measured noninvasively using NIR fluorescent light, and pharmacological modulators of thermogenesis can be screened at relatively high throughput in living animals.

  20. Pulmonary O2 transfer during pulsatile and non-pulsatile perfusion.

    Science.gov (United States)

    Hauge, A; Nicolaysen, G

    1980-07-01

    The importance of the perfusion pattern for the oxygen transfer has been examined in isolated rabbit lungs perfused with plasma at constant volume inflow. The lungs were ventilated with constant tidal volume and constant end-expiratory pressure. Following a standardized rise in FIO2 the rate of rise in pulmonary venous PO2 (delta PO2/delta t) was measured during alternately pulsatile and non-pulsatile perfusion in normal lungs and in lungs made edematous by elevation of left atrial pressure. In normal lungs there was no difference in delta PO2/delta t when the two modes of perfusion were compared. In edematous lungs delta PO/delta t was statistically higher during pulsatile perfusion, indicating a beneficial effect of flow- and pressure pulsations, e.g. a better distribution of V/Q ratios throughout the lungs. In a separate series of expts. the advancement of a high O2 front through the airways was measured, and the two perfusion patterns compared. Since no difference was found, we suggest that the phenomenon of "cardiogenic gas mixing" in the airways in vivo is a result of a direct action of the heart on the lungs rather than arterial pulsations.

  1. A constitutive damage specific DNA-binding protein is synthesized at higher levels in UV-irradiated primate cells

    International Nuclear Information System (INIS)

    Hirschfeld, S.; Levine, A.S.; Ozato, K.; Protic, M.

    1990-01-01

    Using a DNA band shift assay, we have identified a DNA-binding protein complex in primate cells which is present constitutively and has a high affinity for UV-irradiated, double-stranded DNA. Cells pretreated with UV light, mitomycin C, or aphidicolin have higher levels of this damage-specific DNA-binding protein complex, suggesting that the signal for induction can either be damage to the DNA or interference with cellular DNA replication. Physiochemical modifications of the DNA and competition analysis with defined substrates suggest that the most probable target site for the damage-specific DNA-binding protein complex is a 6-4'-(pyrimidine-2'-one)-pyrimidine dimer: specific binding could not be detected with probes which contain -TT- cyclobutane dimers, and damage-specific DNA binding did not decrease after photoreactivation of UV-irradiated DNA. This damage-specific DNA-binding protein complex is the first such inducible protein complex identified in primate cells. Cells from patients with the sun-sensitive cancer-prone disease, xeroderma pigmentosum (group E), are lacking both the constitutive and the induced damage-specific DNA-binding activities. These findings suggest a possible role for this DNA-binding protein complex in lesion recognition and DNA repair of UV-light-induced photoproducts

  2. Investigation of contrast agent dosage for perfusion-weighted MRI

    International Nuclear Information System (INIS)

    Erb, G.; Benner, T.; Heiland, S.; Reith, W.; Sartor, K.; Forsting, M.

    1997-01-01

    Purpose: In this study we investigated, whether increasing the dosage of a paramagnetic contrast agent results in a stronger signal decrease in T 2 *-weighted perfusion sequences and therefore more meaningful parameter maps. Material and methods: In a prospective study bolus injection of gadolinium-DTPA was performed at dosages of 0.1, 0.2, and 0.3 mmol/kg body weight (BW) in 10 patients each. Before, during and after bolus injection 40 T 2 *-weighted images of a reference brain slice were acquired within 65.6 seconds on a 1.0 T clinical scanner and perfusion parameters were calculated. Results: Due to the limited signal decrease during bolus passage and the resulting low signal-difference-to-noise ratio (ΔS/N) no reliable differentiation of gray and white matter was possible at a contrast agent dosage of 0.1 mmol/kg BW. Only at higher dosages, both, signal decrease and ΔS/N were strong enough to allow differentiation of gray and white matter and to yield reliable parameter maps. Conclusion: For meaningful MR perfusion imaging at 1.0 T and with the given sequence a contrast agent dosage of at least 0.2 mmol/kg BW is necessary, if a 0.5-molar contrast agent is used. (orig.) [de

  3. Machine perfusion for improving outcomes following renal transplant: current perspectives

    Directory of Open Access Journals (Sweden)

    Cannon RM

    2016-03-01

    Full Text Available Robert M Cannon,1 Glen A Franklin1,2 1The Hiram C Polk Jr MD Department of Surgery, University of Louisville, 2Kentucky Organ Donor Affiliates, Louisville, KY, USAAbstract: There is a disparity between the number of kidneys available for transplantation and the number of patients awaiting an organ while on dialysis. The current kidney waiting list in the US contains more than 100,000 patients. This need has led to the inclusion of older donors with worsening renal function, as well as greater utilization of kidneys from non-heartbeating (donation after cardiac death donors. Coinciding with this trend has been a growing interest in technology to improve the function of these more marginal organs, the most important of which currently is machine perfusion (MP of donated kidneys after procurement. While this technology has no standard guidelines currently for comprehensive use, there are many studies that demonstrate higher organ yield and function after a period of MP. Particularly with the older donor and during donation after cardiac death cases, MP may offer some significant benefits. This manuscript reviews all of the current literature regarding MP and its role in renal transplantation. We will discuss both the experience in Europe and the US using machine perfusion for donated kidneys.Keywords: machine perfusion, renal transplantation, kidney pumping, renal failure, organ donation

  4. Myocardial perfusion scintigraphy - possibilities of diagnosing CAD

    International Nuclear Information System (INIS)

    Tsonevska, A.

    1998-01-01

    A reviewing the diagnostic methods used in the intricate process of evaluating CAD patients in a attempt to establish the role played by radionuclide methods in the diagnostic strategy is done. The perfusion cardiotropic radiopharmaceuticals used and the various methods of evaluating myocardial are discussed. Although 210 Tl-chloride is the most widely used myocardial perfusion agent, recently 99m Tc-MIBI is proposed as an alternative because of its advantages. Myocardial perfusion assessment is done by various techniques depending on the specific aim, each of them having its proper advantages and shortcomings. The inference is reached that regardless of the routine practical implementation of myocardial perfusion scintigraphy and comprehensive studies along this line in course, there are problems still not well enough clarified awaiting solution

  5. MRI of pulmonary perfusion; MRT der Lungenperfusion

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany); Risse, F.; Semmler, W. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Medizinische Physik in der Radiologie, Heidelberg (Germany); Schoenberg, S.O.; Reiser, M.F. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen (Germany). Institut fuer Klinische Radiologie; Kauczor, H.-U. [Deutsches Krebsforschungszentrum (DKFZ), Abteilung Radiologie, Heidelberg (Germany)

    2006-04-15

    Lung perfusion is a crucial prerequisite for effective gas exchange. Quantification of pulmonary perfusion is important for diagnostic considerations and treatment planning in various diseases of the lungs. Besides disorders of pulmonary vessels such as acute pulmonary embolism and pulmonary hypertension, these also include diseases of the respiratory tract and lung tissue as well as pulmonary tumors. This contribution presents the possibilities and technical requirements of MRI for diagnostic work-up of pulmonary perfusion. (orig.) [German] Die Perfusion der Lunge ist eine entscheidende Voraussetzung fuer einen effektiven Gasaustausch. Die Bestimmung der Lungenperfusion ist bei verschiedenen Erkrankungen der Lunge fuer Diagnostik und Therapieplanung bedeutsam. Hierzu zaehlen neben Erkrankungen der Lungengefaesse wie akute Lungenembolie und pulmonale Hypertension ebenso Erkrankungen der Atemwege, des Lungengeruests und Lungentumoren. In diesem Beitrag werden die Moeglichkeiten und technischen Voraussetzungen der MRT zur Diagnostik der Lungenperfusion dargestellt. (orig.)

  6. Acute stroke: automatic perfusion lesion outlining using level sets.

    Science.gov (United States)

    Mouridsen, Kim; Nagenthiraja, Kartheeban; Jónsdóttir, Kristjana Ýr; Ribe, Lars R; Neumann, Anders B; Hjort, Niels; Østergaard, Leif

    2013-11-01

    To develop a user-independent algorithm for the delineation of hypoperfused tissue on perfusion-weighted images and evaluate its performance relative to a standard threshold method in simulated data, as well as in acute stroke patients. The study was approved by the local ethics committee, and patients gave written informed consent prior to their inclusion in the study. The algorithm identifies hypoperfused tissue in mean transit time maps by simultaneously minimizing the mean square error between individual and mean perfusion values inside and outside a smooth boundary. In 14 acute stroke patients, volumetric agreement between automated outlines and manual outlines determined in consensus among four neuroradiologists was assessed with Bland-Altman analysis, while spatial agreement was quantified by using lesion overlap relative to mean lesion volume (Dice coefficient). Performance improvement relative to a standard threshold approach was tested with the Wilcoxon signed rank test. The mean difference in lesion volume between automated outlines and manual outlines was -9.0 mL ± 44.5 (standard deviation). The lowest mean volume difference for the threshold approach was -25.8 mL ± 88.2. A significantly higher Dice coefficient was observed with the algorithm (0.71; interquartile range [IQR], 0.42-0.75) compared with the threshold approach (0.50; IQR, 0.27- 0.57; P , .001). The corresponding agreement among experts was 0.79 (IQR, 0.69-0.83). The perfusion lesions outlined by the automated algorithm agreed well with those defined manually in consensus by four experts and were superior to those obtained by using the standard threshold approach. This user-independent algorithm may improve the assessment of perfusion images as part of acute stroke treatment. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13121622/-/DC1. RSNA, 2013

  7. Scaling of cerebral blood perfusion in primates and marsupials.

    Science.gov (United States)

    Seymour, Roger S; Angove, Sophie E; Snelling, Edward P; Cassey, Phillip

    2015-08-01

    The evolution of primates involved increasing body size, brain size and presumably cognitive ability. Cognition is related to neural activity, metabolic rate and rate of blood flow to the cerebral cortex. These parameters are difficult to quantify in living animals. This study shows that it is possible to determine the rate of cortical brain perfusion from the size of the internal carotid artery foramina in skulls of certain mammals, including haplorrhine primates and diprotodont marsupials. We quantify combined blood flow rate in both internal carotid arteries as a proxy of brain metabolism in 34 species of haplorrhine primates (0.116-145 kg body mass) and compare it to the same analysis for 19 species of diprotodont marsupials (0.014-46 kg). Brain volume is related to body mass by essentially the same exponent of 0.70 in both groups. Flow rate increases with haplorrhine brain volume to the 0.95 power, which is significantly higher than the exponent (0.75) expected for most organs according to 'Kleiber's Law'. By comparison, the exponent is 0.73 in marsupials. Thus, the brain perfusion rate increases with body size and brain size much faster in primates than in marsupials. The trajectory of cerebral perfusion in primates is set by the phylogenetically older groups (New and Old World monkeys, lesser apes) and the phylogenetically younger groups (great apes, including humans) fall near the line, with the highest perfusion. This may be associated with disproportionate increases in cortical surface area and mental capacity in the highly social, larger primates. © 2015. Published by The Company of Biologists Ltd.

  8. Analysis of blood flow in a third ventricular ependymoma and an olfactory bulb meningioma by usisng perfusion computed tomography

    International Nuclear Information System (INIS)

    Kishimoto, M.; Yamada, K.; Seok, J.S.; Shimizu, J.; Kobayashi, Y.; Akiba, Y.; Morishita, Y.; Iwasa, A.; Iwasaki, T.; Miyake, Y.

    2008-01-01

    Brain perfusion computed tomography (CT) scanning was performed in a mongrel dog and a golden retriever that were diagnosed with third ventricular tumor and olfactory bulb tumor, respectively, by contrast-enhanced CT. The tumors were pathologically diagnosed as ependymoma and meningioma, respectively. Perfusion CT results revealed that the ependymoma in this study had a lower blood flow, higher blood volume, and greater transit time of blood than the adjacent brain tissue. Further, the meningioma in this study had a higher blood flow, higher blood volume, and greater transit time of blood than the adjacent brain tissue. Perfusion CT can potentially be used for the grading of brain tumors and narrowing differential diagnosis, provided the perfusion CT data of animals are accumulated

  9. Improved exercise myocardial perfusion during lidoflazine therapy

    International Nuclear Information System (INIS)

    Shapiro, W.; Narahara, K.A.; Park, J.

    1983-01-01

    Lidoflazine is a synthetic drug with calcium-channel blocking effects. In a study of 6 patients with severe classic angina pectoris, single-blind administration of lidoflazine was associated with improved myocardial perfusion during exercise as determined by thallium-201 stress scintigraphy. These studies demonstrate that lidoflazine therapy is associated with relief of angina, an increased physical work capacity, and improved regional myocardial perfusion during exercise

  10. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8...

  11. Ventilation-perfused studies using SPECT

    International Nuclear Information System (INIS)

    Zwijnenburg, A.

    1989-01-01

    A method for the quantitative analysis of ventilation-perfusion SPECT studies is decribed and an effort is made to evaluate its usefullness. The technical details of the emthod are described. In the the transaxial reconstructions of the tomographic studies the contour of the lungs is detected and regional values of lung volume, ventilation, perfusion and ventilation-perfusion ratios are calculated. The method is operator independent. The lung volume calculations from the SPECT studies are validated by comparing them with lung volume measurements using the helium dilution technique. A good correlation (r=0.91) was found between the two volumes. SPECT volume was greater than the volume measured with helium dilution, which was attributed to non-gas-containing structures in the. lungs. The use of ventilation-perfusion ratio SPECT is described to evaluate the effect of ionizing radiation on the lungs in patients treated with mantle field irradiation for Hodgkin's disease. Perfusion changes appear as early as 2 months after the start of irradiation. Ventilation changes appear later and relatively minor. No changes are seen outside the radiation portals. The ventilation-perfusion inequality in pulmonary sarcoidosis is treated. It is suggested that the decrease D LCO in these patients may be partly due to an even distribution of ventilation perfusion ratios. An effort is made to establish the properties of a new tracer used for the assessment of the metabolic function of the pulmonary endothelium. The lung uptake of I-123 IMP mimics the distribution of a perfusion tracer and it is suggested that this tracer may be useful for the early detection of pulmonary vascular damage, even when blood flow is still intact. Some aspects of the use of Kr-81m as a ventilation tracer are discussed as well as the effect of noise on Kr-81m SPECT reconstructions. (author). 146 refs.; 39 figs.; 8 tabs

  12. Myocardial perfusion in silent myocardial ischemia

    International Nuclear Information System (INIS)

    Narita, Michihiro; Kurihara, Tadashi; Murano, Kenichi; Usami, Masahisa

    1989-01-01

    To investigate myocardial perfusion in silent myocardial ischemia, we performed exercise stress myocardial tomography with thallium-201 (Tl) in 85 patients with coronary artery disease (CAD). Exercise stress myocardial tomography was obtained both immediately after exercise and three hours later. Patients were classified into two groups according to the presence (Symptomatic Group, n=36) or absence (Silent Group, n=49) of chest pain during exercise stress. Clinical features (age, gender and history of myocardial infarction) and arteriographically determined severity of CAD were the same in both groups. The extent of myocardial ischemia (% Ischemia) estimated by exercise stress myocardial tomography was the same in each group (30±10 % in Silent Group, 28±12 % in Symptomatic Group, NS). The severity of exercise-induced myocardial ischemia was expressed as a minimal value of myocardial Tl washout rate (minimal WOR) of each patient. Although exercise heart rate was identical in both groups, minimal WOR in Silent Group was significantly higher than that of Symptomatic Group (4±10% vs -16±14%, p<0.001). The study in patients who exhibited both silent and symptomatic ischemia showed the same results. These findings suggest that the severity of ischemia is a fundamental factor in determining the presence or absence of pain during exercise induced ischemia. (author)

  13. Correlation of angina pectoris and perfusion decrease by collateral circulation in single-vessel coronary chronic total occlusion using myocardial perfusion single-photon emssion computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Geon; Park, Ki Seong; Kang, Sae Ryung [Chonnam National University Hospital, Gwangju (Korea, Republic of); and others

    2016-03-15

    To evaluate the perfusion decrease in donor myocardium by collateral circulation and its correlation with angina pectoris in patients with chronic total occlusion (CTO) using myocardial perfusion single-photon emission computed tomography (MPS). Thirty-six patients with single-vessel CTO without any other stenosis were included. All patients underwent MPS and coronary angiography (CAG) within 2 months. Total 72 donor arteries were evaluated for the grades of collaterals to the CTO artery using the Rentrop grading system on CAG. Perfusion defects and perfusion scores in donor and CTO territories were analyzed on MPS. Myocardial perfusion of donor and CTO territories were evaluated according to the presence of angina pectoris and the grades of collateral circulation. When the CTO territory was ischemic, symptomatic patients showed higher summed difference scores in the CTO territory compared to asymptomatic patients (3.5 ± 2.4 vs. 1.5 ± 0.8 for symptomatic and asymptomatic groups respectively; p = 0.034). However, when the CTO territory was nonischemic, symptomatic patients showed higher summed stress scores (SSS, 4.3 ± 2.9 vs. 1.6 ± 1.2; p = 0.032) and summed rest scores (SRS, 4.2 ± 2.5 vs. 1.5 ± 1.1; p = 0.003) in the donor territories. On the per-vessel analysis, perfusion defects in donor territories were more frequent (0 % vs. 53 % vs. 86 % for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p < 0.001) and showed higher SSS (0.0 ± 0.0, 1.3 ± 1.6 and 2.1 ± 1.1 for Rentrop 0, Rentrop 1–2 and Rentrop 3, respectively; p = 0.001) and SRS (0.0 ± 0.0, 1.0 ± 1.4 and 1.7 ± 1.2; p = 0.003) at higher Rentrop grades, but their patterns were variable. Angina pectoris was related to either ischemia of the myocardium beyond CTO or a perfusion decrease in the donor myocardium. The perfusion decrease in donor myocardium positively correlated with the collateral grades.

  14. Modulation of Higher Order Chromatin Conformation in Mammalian Cell Nuclei Can Be Mediated by Polyamines and Divalent Cations.

    Directory of Open Access Journals (Sweden)

    Ashwat Visvanathan

    Full Text Available The organisation of the large volume of mammalian genomic DNA within cell nuclei requires mechanisms to regulate chromatin compaction involving the reversible formation of higher order structures. The compaction state of chromatin varies between interphase and mitosis and is also subject to rapid and reversible change upon ATP depletion/repletion. In this study we have investigated mechanisms that may be involved in promoting the hyper-condensation of chromatin when ATP levels are depleted by treating cells with sodium azide and 2-deoxyglucose. Chromatin conformation was analysed in both live and permeabilised HeLa cells using FLIM-FRET, high resolution fluorescence microscopy and by electron spectroscopic imaging microscopy. We show that chromatin compaction following ATP depletion is not caused by loss of transcription activity and that it can occur at a similar level in both interphase and mitotic cells. Analysis of both live and permeabilised HeLa cells shows that chromatin conformation within nuclei is strongly influenced by the levels of divalent cations, including calcium and magnesium. While ATP depletion results in an increase in the level of unbound calcium, chromatin condensation still occurs even in the presence of a calcium chelator. Chromatin compaction is shown to be strongly affected by small changes in the levels of polyamines, including spermine and spermidine. The data are consistent with a model in which the increased intracellular pool of polyamines and divalent cations, resulting from depletion of ATP, bind to DNA and contribute to the large scale hyper-compaction of chromatin by a charge neutralisation mechanism.

  15. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

    2016-01-01

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

  16. Insulin degradation products from perfused rat kidney

    International Nuclear Information System (INIS)

    Duckworth, W.C.; Hamel, F.G.; Liepnieks, J.; Peavy, D.; Frank, B.; Rabkin, R.

    1989-01-01

    The kidney is a major site for insulin metabolism, but the enzymes involved and the products generated have not been established. To examine the products, we have perfused rat kidneys with insulin specifically iodinated on either the A14 or the B26 tyrosine. Labeled material from both the perfusate and kidney extract was examined by Sephadex G50 and high-performance liquid chromatography (HPLC). In perfusate from a filtering kidney, 22% of the insulin-sized material was not intact insulin on HPLC. With the nonfiltering kidney, 10.6% was not intact insulin. Labeled material from HPLC was sulfitolyzed and reinjected on HPLC. By use of 125 I-iodo(A14)-insulin, almost all the degradation products contained an intact A-chain. By use of 125 I-iodo(B26)-insulin, several different B-chain-cleaved products were obtained. The material extracted from the perfused kidney was different from perfusate products but similar to intracellular products from hepatocytes, suggesting that cellular metabolism by kidney and liver are similar. The major intracellular product had characteristics consistent with a cleavage between the B16 and B17 amino acids. This product and several of the perfusate products are also produced by insulin protease suggesting that this enzyme is involved in the degradation of insulin by kidney

  17. CT perfusion study of neck lymph nodes

    International Nuclear Information System (INIS)

    Zhong Jin; Liu Jun; Hua Rui; Qiao Hui; Gong Yi

    2011-01-01

    Objective: To study the CT perfusion features of various lymph nodes in the neck. Methods: Dynamic perfusion CT scanning was performed in 83 neck lymph nodes proved by pathology, including tuberculosis lymph nodes, lymphoma and metastatic lymph nodes. The shapes, blood flow modes, and perfusion parameters of these lymph nodes were compared among 3 groups. Statistical analysis of L/T and CT perfusion parameters was performed by one-way ANOVA and LSD test. Results: The values of MTT of tuberculosis lymph nodes, lymphoma and metastatic lymph nodes were (28.13±5.08), (31.08±5.82), and (11.24±5.31) s, respectively. The MTT of metastatic lymph nodes was statistically lower than that of tuberculosis lymph nodes and lymphoma (P -1 · 100 g -1 , respectively. The values of BV were (24.68±2.84), (25.30±3.16), and (25.15± 8.81) ml·100 g -1 respectively. The values of TTP were (40.90±8.85), (40.67±6.45), and (40.98±6.62) s, respectively. There were no significant differences in L/T, BF, BV and TTP among tuberculosis lymph nodes, lymphoma and metastatic lymph nodes (P>0.05). Conclusion: CT perfusion, especially combination functional imaging with perfusion images may be helpful in judging the nature of neck lymph nodes. (authors)

  18. Perfusion CT assessment of the colon and rectum: Feasibility of quantification of bowel wall perfusion and vascularization

    International Nuclear Information System (INIS)

    Khan, Sairah; Goh, Vicky; Tam, Emily; Wellsted, David; Halligan, Steve

    2012-01-01

    The aim was to determine the feasibility of vascular quantification of the bowel wall for different anatomical segments of the colorectum. Following institutional ethical approval and informed consent, 39 patients with colorectal cancer underwent perfusion CT. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS) were assessed for different segments of the colorectum: ascending, transverse, descending colon, sigmoid, or rectum, that were distant from the tumor, and which were proven normal on contemporary colonoscopy, and subsequent imaging and clinical follow up. Mean (SD) for BF, BV, MTT and PS for the different anatomical colorectal segments were obtained and compared using a pooled t-test. Significance was at 5%. Assessment was not possible in 9 of 39 (23%) patients as the bowel wall was ≤5 mm precluding quantitative analysis. Forty-four segments were evaluated in the remaining 30 patients. Mean BF was higher in the proximal than distal colon: 24.0 versus 17.8 mL/min/100 g tissue; p = 0.009; BV, MTT and PS were not significantly different; BV: 3.46 versus 3.15 mL/100 g tissue, p = 0.45; MTT: 15.1 versus 18.3 s; p = 0.10; PS: 6.84 versus 8.97 mL/min/100 tissue, p = 0.13, respectively. In conclusion, assessment of bowel wall perfusion may fail in 23% of patients. The colorectum demonstrates segmental differences in perfusion.

  19. Hydrogels from feather keratin show higher viscoelastic properties and cell proliferation than those from hair and wool keratins.

    Science.gov (United States)

    Esparza, Yussef; Bandara, Nandika; Ullah, Aman; Wu, Jianping

    2018-09-01

    Hydrogel prepared from keratin shows potential applications in tissue engineering. However, the importance of the keratin sources has not been considered. The objectives of this study were to characterize and compare the rheological (storage modulus), physical (porosity, pore size, swelling capacity, and water contact angle) and in vitro cell compatibility of hydrogel scaffolds prepared from various keratin sources. Keratins were characterized by means of their molecular weight, amino acid composition, thermal and conformational properties. Hydrogels from chicken feather keratins demonstrated substantially higher storage modulus (G') than hair and wool keratin hydrogels. However, higher swelling capacity (>3000%) was determined in hair and wool over feather keratin (1500%) hydrogels. Our results suggest that small molecular weight and β-sheet conformation of feather keratin (~10 kDa) facilitated the self-assembly of rigid hydrogels through disulfide bond re-oxidation. Whereas, high molecular weight (10-75 kDa) stretchable α-helix conformation in hair and wool keratins resulted in weaker hydrogels. The cell cultures using fibroblasts showed the highest proliferation rate on chicken feather keratin hydrogel scaffolds. After 15 days of culture, partial breakdown of keratin fibers was observed. Results indicate that stiffer avian keratins can be used to fabricate more mechanically robust biomaterials than mammalian keratins. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Aging and stem cell therapy: AMPK as an applicable pharmacological target for rejuvenation of aged stem cells and achieving higher efficacy in stem cell therapy.

    Science.gov (United States)

    Khorraminejad-Shirazi, Mohammadhossein; Farahmandnia, Mohammad; Kardeh, Bahareh; Estedlal, Alireza; Kardeh, Sina; Monabati, Ahmad

    2017-10-19

    In recent years, tissue regeneration has become a promising field for developing stem cell-based transplantation therapies for human patients. Adult stem cells are affected by the same aging mechanisms that involve somatic cells. One of the mechanisms involved in cellular aging is hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and disruption of 5' adenosine monophosphate-activated protein kinase (AMPK). Aging of stem cells results in their impaired regenerative capacity and depletion of stem cell pools in adult tissue, which results in lower efficacy of stem cell therapy. By utilizing an effective therapeutic intervention for aged stem cells, stem cell therapy can become more promising for future application. mTORC1 inhibition is a practical approach to preserve the stem cell pool. In this article, we review the dynamic interaction between sirtuin (silent mating type information regulation 2 homolog) 1, AMPK, and mTORC1. We propose that using AMPK activators such as 5-aminoimidazole-4-carboxamide ribonucleotide, A769662, metformin, and oxidized nicotinamide adenine dinucleotide (NAD + ) are practical ways to be employed for achieving better optimized results in stem cell-based transplantation therapies. Copyright © 2017 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

  1. Perfusion of surgical cavity wall enhancement in early post-treatment MR imaging may stratify the time-to-progression in glioblastoma.

    Directory of Open Access Journals (Sweden)

    Ji Eun Park

    Full Text Available To determine if perfusion in surgical cavity wall enhancement (SCWE obtained in early post-treatment MR imaging can stratify time-to-progression (TTP in glioblastoma.This study enrolled 60 glioblastoma patients with more than 5-mm-thick SCWEs as detected on contrast-enhanced MR imaging after concurrent chemoradiation therapy. Two independent readers categorized the shape and perfusion state of SCWEs as nodular or non-nodular and as having positive or negative perfusion compared with the contralateral grey matter on arterial spin labeling (ASL. The perfusion fraction on ASL within the contrast-enhancing lesion was calculated. The independent predictability of TTP was analyzed using the Kaplan-Meier method and Cox proportional hazards modelling.The perfusion fraction was higher in the non-progression group, significantly for reader 2 (P = 0.03 and borderline significantly for reader 1 (P = 0.08. A positive perfusion state and (P = 0.02 a higher perfusion fraction of the SCWE were found to become an independent predictor of longer TTP (P = 0.001 for reader 1 and P < 0.001 for reader 2. The contrast enhancement pattern did not become a TTP predictor.Assessment of perfusion in early post-treatment MR imaging can stratify TTP in patients with glioblastoma for adjuvant temozolomide therapy. Positive perfusion in SCWEs can become a predictor of a longer TTP.

  2. Intra-peritoneal administration of interleukin-1 beta induces impaired insulin release from the perfused rat pancreas

    DEFF Research Database (Denmark)

    Wogensen, L; Helqvist, S; Pociot, F

    1990-01-01

    Previous studies have demonstrated a stimulatory effect of interleukin-1 beta (IL-1 beta) on insulin and glucagon release from the perfused rat pancreas, accompanied by selective lysis of 20% of beta-cells as assessed by electronmicroscopy. However, we have not observed an inhibitory action of IL-1...... beta on insulin release from the perfused pancreas as shown for isolated islets. To test whether periodical exposure of the endocrine pancreas to circulating IL-1 beta in vivo affects insulin release from the intact perfused pancreas, rats were treated with daily intraperitoneal injections of 4...

  3. Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve by 82Rb PET/CT in HIV-Infected Patients

    Directory of Open Access Journals (Sweden)

    Mathilde Ørbæk

    2017-05-01

    Full Text Available After the introduction of antiretroviral therapy (ART the life expectancy of patients infected with human immunodeficiency virus (HIV is now approaching that of the general population and the importance of non-AIDS co-morbidities is increasing. Specifically, the risk of coronary artery disease (CAD seems to be higher in HIV-infected patients and an accurate risk prediction of CAD is of high importance for optimal long term treatment. In this study, we assessed the correlation of the endoPAT, which is an office-based CVD screening tool with the myocardial perfusion reserve by 82-rubidium PET/CT. We measured the reactive hyperemia index, which is a measure of the endothelial responsiveness, by the use of an endoPAT device (Itamar Medical, Caesarea, Israel in 48 ART treated HIV-infected patients with high CD 4 cell counts and viral suppression (HIV-RNA < 20 copies/mL, who had previously undergone measurement of the myocardial perfusion reserve by 82-rubidium PET/CT for study purposes. We found an inverse correlation between the reactive hyperemia index and the myocardial perfusion reserve which most likely indicates different vascular physiology. This study did not find evidence to suggest the immediate implementation of the reactive hyperemia index as a screening tool for early coronary artery disease in well-treated HIV-infected patients pending further validation in larger prospective studies.

  4. MDS shows a higher expression of hTERT and alternative splice variants in unactivated T-cells.

    Science.gov (United States)

    Dong, Wen; Wu, Lei; Sun, Houfang; Ren, Xiubao; Epling-Burnette, Pearlie K; Yang, Lili

    2016-11-01

    Telomere instability and telomerase reactivation are believed to play an important role in the development of myelodysplastic syndromes (MDS). Abnormal enzymatic activity of human telomerase reverse transcriptase (hTERT), and its alternative splice variants have been reported to account for deregulated telomerase function in many cancers. In this study, we aim to compare the differences in expression of hTERT and hTERT splice variants, as well as telomere length and telomerase activity in unstimulated T-cells between MDS subgroups and healthy controls. Telomere length in MDS cases was significantly shorter than controls (n = 20, pMDS using World Health Organization classification (WHO subgroups versus control: RARS, p= 0.009; RCMD, p=0.0002; RAEB1/2, p=0.004, respectively) and the International Prognostic Scoring System (IPSS subgroups: Low+Int-1, pMDS patients (n=20) had significantly higher telomerase activity (p=0.002), higher total hTERT mRNA levels (p=0.001) and hTERT α+β- splice variant expression (pMDS (r=0.58, p=0.007). This data is in sharp contrast to data published previously by our group showing a reduction in telomerase and hTERT mRNA in MDS T-cells after activation. In conclusion, this study provides additional insight into hTERT transcript patterns and activity in peripheral T-cells of MDS patients. Additional studies are necessary to better understand the role of this pathway in MDS development and progression.

  5. Bioprinting of 3D Convoluted Renal Proximal Tubules on Perfusable Chips

    Science.gov (United States)

    Homan, Kimberly A.; Kolesky, David B.; Skylar-Scott, Mark A.; Herrmann, Jessica; Obuobi, Humphrey; Moisan, Annie; Lewis, Jennifer A.

    2016-10-01

    Three-dimensional models of kidney tissue that recapitulate human responses are needed for drug screening, disease modeling, and, ultimately, kidney organ engineering. Here, we report a bioprinting method for creating 3D human renal proximal tubules in vitro that are fully embedded within an extracellular matrix and housed in perfusable tissue chips, allowing them to be maintained for greater than two months. Their convoluted tubular architecture is circumscribed by proximal tubule epithelial cells and actively perfused through the open lumen. These engineered 3D proximal tubules on chip exhibit significantly enhanced epithelial morphology and functional properties relative to the same cells grown on 2D controls with or without perfusion. Upon introducing the nephrotoxin, Cyclosporine A, the epithelial barrier is disrupted in a dose-dependent manner. Our bioprinting method provides a new route for programmably fabricating advanced human kidney tissue models on demand.

  6. Lower expression of CADM1 and higher expression of MAL in Merkel cell carcinomas are associated with Merkel cell polyomavirus infection and better prognosis.

    Science.gov (United States)

    Iwasaki, Takeshi; Matsushita, Michiko; Nonaka, Daisuke; Nagata, Keiko; Kato, Masako; Kuwamoto, Satoshi; Murakami, Ichiro; Hayashi, Kazuhiko

    2016-02-01

    Merkel cell carcinoma (MCC) is a clinically aggressive neuroendocrine skin cancer; 80% of the cases are associated with the Merkel cell polyomavirus (MCPyV). We previously reported that MCPyV-negative MCCs have more irregular nuclei with abundant cytoplasm and significantly unfavorable outcomes than do MCPyV-positive MCCs. These results suggest that some cell adhesion or structural stabilization molecules are differently expressed depending on MCPyV infection status. Thus, we investigated the association of prognosis or MCPyV infection status in MCCs with cell adhesion molecule 1 (CADM1)/differentially expressed in adenocarcinoma of the lung protein 1 (DAL-1)/membrane protein, palmitoylated 3 (MPP3) tripartite complex and mal T-cell differentiation protein (MAL) expression, which play important roles in cell adhesion and oncogenesis and are related to cancer outcomes in various malignancies, to elucidate the role of these molecules. We analyzed the pathological and molecular characteristics of 26 MCPyV-positive and 15 MCPyV-negative MCCs. Univariate Cox regression analysis showed that advanced age (hazard ratio [HR], 8.249; P = .007) and high CADM1 expression (HR, 5.214; P = .012) were significantly unfavorable overall survival parameters, whereas MCPyV infection (HR, 0.043, P Merkel cells expressed DAL-1 and MAL but not CADM1. This study revealed that MCPyV-negative MCCs significantly expressed higher CADM1 and lower MAL than MCPyV-positive MCCs; these expression levels were markedly related to unfavorable outcomes. These data will give us important insights to develop novel molecular target therapies for MCCs. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. The evaluation of the degree of impairment of pulmonary perfusion in lung cancer patients treated by radiotherapy by the quantification of nonuniform distribution of lung perfusion scintigraphy SPECT

    International Nuclear Information System (INIS)

    Mitomo, Osamu; Tsunoda, Takashi; Kuwabara, Hidemasa

    2004-01-01

    patients was 26.4±1.4, which was almost equal to that of the pulmonary group including the chronic obstructive pulmonary diseases, and significantly higher than that of cardiac or non-cardiopulmonary group. The irradiated lung cancer patients with complications of pulmonary or cardiopulmonary diseases showed a significantly increased D index, compared with patients without complications. Distribution index of tumor-bearing lung (D r/l index) was significantly higher than that of non-tumor-bearing lung. The D r/l index of tumor-bearing lung of small cell carcinoma patients significantly increased, compared with that of adenocarcinoma patients, and significantly increased according to whether or not the primary tumor occupied the hilar region and degree of extension of tumor invasion especially in the hilum as well as the mediastinum. In the follow-up irradiated lung cancer patients, the D index and D r/l index of non-tumor-bearing lung post-radiotherapy significantly increased, compared with pre-radiotherapy. It is considered that the distribution index quantifying nonuniform distribution in the SPECT enables evaluation of the degree of impairment of lung as a whole, tumor-bearing lung, and non-tumor-bearing lung in lung cancer patients, and results in presenting a useful indicator for radiotherapeutic planning and following up respiratory function after radiotherapy. (author)

  8. Regional cortical hyper perfusion on perfusion CT during postical motor deficit: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Hye Jin [Dept. of Radiology, Haeundae Paik Hospital, Inje University College of Medicine, Busan (Korea, Republic of)

    2013-08-15

    Postictal neurologic deficit is a well-known complication mimicking the manifestation of a stroke. We present a case of a patient with clinical evidence of Todd's paralysis correlating with reversible postictal parenchymal changes on perfusion CT and magnetic resonance (MR) imaging. In this case, perfusion CT and MR imaging were helpful in the differential diagnosis of stroke-mimicking conditions.

  9. The Groningen hypothermic liver perfusion pump : Functional evaluation of a new machine perfusion system

    NARCIS (Netherlands)

    van der Plaats, A.; Maathuis, M. H. J.; Hart, N. A. 't; Bellekom, A. A.; Hofker, H. S.; van der Houwen, E. B.; Verkerke, G. J.; Leuvenink, H. G. D.; Verdonck, P.; Ploeg, R. J.; Rakhorst, G.

    2006-01-01

    To improve preservation of donor livers, we have developed a portable hypothermic machine perfusion (HMP) system as an alternative for static cold storage. A prototype of the system was built and evaluated on functionality. Evaluation criteria included 24 h of adequate pressure controlled perfusion,

  10. Esophageal blood flow in the cat. Normal distribution and effects of acid perfusion

    International Nuclear Information System (INIS)

    Hollwarth, M.E.; Smith, M.; Kvietys, P.R.; Granger, D.N.

    1986-01-01

    The radioactive microsphere technique was used to estimate blood flow to different regions of the esophagus and to adjacent regions of the stomach before and after perfusion of the esophagus with hydrochloric acid (pH 1.5) for 5 min. Under resting conditions total blood flow, as well as blood flow to the mucosal-submucosal layer and the muscular layer, to both sphincters was significantly higher than to the esophageal body. Blood flow to the adjacent regions of the stomach was significantly higher than esophageal blood flow. Acid perfusion resulted in a large increase in total blood flow in both sphincters and the lower esophageal body. Gastric blood flow was not altered by acid perfusion. The esophageal hyperemia resulted primarily from an increase in blood flow to the muscular layer; mucosal-submucosal blood flow was increased only in the lower esophageal sphincter. The present study indicates that short periods (5 min) of gastroesophageal reflux may increase esophageal blood flow

  11. Ex Vivo Normothermic Perfusion Induces Donor-Derived Leukocyte Mobilization and Removal Prior to Renal Transplantation

    Directory of Open Access Journals (Sweden)

    John P. Stone

    2016-11-01

    Discussion: We demonstrate that ex vivo normothermic perfusion initiates an inflammatory cytokine storm and release of mitochondrial and genomic DNA. This is likely to be responsible for immune cell activation and mobilization into the circuit prior to transplantation. Interestingly this did not have an impact on renal function. These data therefore suggest that normothermic perfusion can be used to immunodeplete and to saturate the pro-inflammatory capacity of donor kidneys prior to transplantation.

  12. Brain perfusion abnormalities in patients with euthyroid autoimmune thyroiditis

    Energy Technology Data Exchange (ETDEWEB)

    Piga, M.; Serra, A.; Loi, G.L.; Satta, L. [University of Cagliari, Nuclear Medicine - Department of Medical Sciences ' ' M. Aresu' ' , Cagliari (Italy); Deiana, L.; Liberto, M. Di; Mariotti, S. [University of Cagliari, Endocrinology - Department of Medical Sciences ' ' M. Aresu' ' , Cagliari (Italy)

    2004-12-01

    Brain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto's thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with euthyroid HT without any clinical evidence of CNS involvement by means of {sup 99m}Tc-ECD brain SPECT. Sixteen adult patients with HT entered this study following informed consent. The diagnosis was based on the coexistence of high titres of anti-thyroid auto-antibodies and diffuse hypoechogenicity of the thyroid on ultrasound in association with normal circulating thyroid hormone and TSH concentrations. Nine consecutive adult patients with non-toxic nodular goitre (NTNG) and ten healthy subjects matched for age and sex were included as control groups. All patients underwent {sup 99m}Tc-ECD brain SPECT. Image assessment was both qualitative and semiquantitative. Semiquantitative analysis was performed by generation of four regions of interest (ROI) for each cerebral hemisphere - frontal, temporal, parietal and occipital - and one for each cerebellar hemisphere in order to evaluate cortical perfusion asymmetry. The Asymmetry Index (AI) was calculated to provide a measurement of both magnitude and direction of perfusion asymmetry. As assessed by visual examination, {sup 99m}Tc-ECD cerebral distribution was irregular and patchy in HT patients, hypoperfusion being more frequently found in frontal lobes. AI revealed abnormalities in 12/16 HT patients, in three of the nine NTNG patients and in none of the normal controls. A significant difference in the mean AI was found between patients with HT and both patients with NTNG (p<0.003) and normal controls (p<0.001), when only frontal lobes were considered. These results show the high prevalence of brain perfusion

  13. 31P-NMR studies on perfused mouse liver

    International Nuclear Information System (INIS)

    McLaughlin, A.C.; Takeda, H.; Chance, B.

    1978-01-01

    From a metabolic viewpoint, the most important organ in the body is the liver. In contrast to more specialized organs such as heart and kidney which perform only one major function, the liver performs a number of major metabolic functions. Two of the most important functions are the catabolism and storage of foodstuffs (in the form of glycogen) and the control of most of the constituents of the blood (in particular, the blood glucose level). Most of these functions are localized within a single type of cell. One way that the liver is able to regulate these diverse reactions is by the control of the ATP level in the cell. Encouraged by the recent success of many groups in using 31 P-NMR to provide a continuous and non-destructive monitor of ATP levels in isolated cells, skeletal muscle, and perfused organs such as heart and kidney, 31 P-NMR was used to investigate ATP levels in perfused liver of mice

  14. Genesis of B lymphocytes in the bone marrow: extravascular and intravascular localization of surface IgM-bearing cells in mouse bone marrow detected by electron-microscope radioautography after in vivo perfusion of 125I anti-IgM antibody

    International Nuclear Information System (INIS)

    Osmond, D.G.; Batten, S.J.

    1984-01-01

    The role of mammalian bone marrow in generating surface IgM (sIgM)-bearing B lymphocytes is reviewed. Precursor cells in the marrow give rise to large, rapidly dividing cells bearing free cytoplasmic mu chains (c mu). The progeny of the large c mu+ cells form a population of small, nondividing c mu+ cells that mature into small lymphocytes, progressively expressing sIgM and other B-cell surface membrane components. Newly formed sIgM+ cells soon migrate through the bloodstream to the spleen and other lymphoid tissues, where they may die after a short lifespan or be activated to produce antibody molecules. The large-scale lymphocytopoiesis in the bone marrow thus maintains a population of rapidly renewed virgin B lymphocytes in the peripheral lymphoid tissues. A technique for perfusing radiolabeled anti-IgM antibodies in young mice has now permitted sIgM+ cells to be detected radioautographically in histological preparations of bone marrow under the electron microscope. Small sIgM+ lymphocytes are situated either singly or in small groups throughout the extravascular hemopoietic compartment of the bone marrow, often near sinusoid walls adjacent to late erythroblasts and reticular cells. Some regional concentrations of sIgM+ cells are apparent. sIgM+ cells also appear in transit through the sinusoidal endothelium and are markedly concentrated in the lumen of some sinusoids. Intrasinusoidal sIgM+ small lymphocytes have high densities of sIgM and long microvilli, on which sIgM molecules are concentrated. These studies reveal the localization and cell associations of specifically identified sIgM+ small lymphocytes in the extravascular marrow compartment and suggest that these cells may also undergo a transient intravascular storage and maturation phase. Use of this in vivo immunolabeling technique to detect other cell-surface markers may further elucidate the microenvironmental basis of B lymphocyte genesis in the bone marrow

  15. [An automatic system controlled by microcontroller for carotid sinus perfusion].

    Science.gov (United States)

    Yi, X L; Wang, M Y; Fan, Z Z; He, R R

    2001-08-01

    To establish a new method for controlling automatically the carotid perfusion pressure. A cheap practical automatic perfusion unit based on AT89C2051 micro controller was designed. The unit, LDB-M perfusion pump and the carotid sinus of an animal constituted an automatic perfusion system. This system was able to provide ramp and stepwise updown perfusion pattern and has been used in the research of baroreflex. It can insure the precision and reproducibility of perfusion pressure curve, and improve the technical level in corresponding medical field.

  16. Intratympanic corticosteroid perfusion in the therapy of Meniere’s disease

    Directory of Open Access Journals (Sweden)

    Sanković-Babić Snežana

    2014-01-01

    Full Text Available Introduction. Over the last two decades the intratympanic perfusion of corticosteroids has been used as a minimally invasive surgical therapy of Meniere’s disease. According to experimental studies the antiinflammatory, immunoprotective, antioxidant and neuroprotective role of the locally perfused corticosteroids was noticed in the inner ear structures. The recovery of action potentials in the cells of the Corti organ was confirmed as well as a decreased expression of aquaporine-1, a glycoprotein responsible for labyrinth hydrops and N and K ions derangement. Objective. The study showed results of intratympanic perfusion therapy with dexamethasone in patients with retractable Meniere’s disease who are resistant to conservative treatment. Methods. Single doses of 4 mg/ml dexamethasone were given intratympanically in 19 patients with retractable Meniere’s disease. Six single successive doses of dexamethasone were administered in the posteroinferior quadrant of the tympanic membrane. Follow-up of the patients was conducted by using a clinical questionnaire a month after completed perfusion series as well as on every third month up to one year. Results. One month after completed first course of perfusions, in 78% of patients, vertigo problems completely ceased or were markedly reduced. The recovery of hearing function was recorded in 68% and marked tinnitus reduction in 84% of patients. After a year of follow-up, in 63% of patients the reduction of vertigo persisted, while hearing function was satisfactory in 52%. Tinitus reduction was present in 73% of patients. Conclusion. Intratympanic perfusion of dexamethasone in patients with Meniere’s disease is a minimally invasive therapeutic method that contributes to the reduction of the intensity of vertigo recurrent attacks, decrease of the intensity of tinnitus and improvement of the average hearing threshold. Patients with chronic diseases and Meniere’s disease who are contraindicted for

  17. Myocardial perfusion imaging with dual energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Kwang Nam [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); De Cecco, Carlo N. [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Caruso, Damiano [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Radiological Sciences, Oncology and Pathology, University of Rome “Sapienza”, Rome (Italy); Tesche, Christian [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Department of Cardiology and Intensive Care Medicine, Heart Center Munich-Bogenhausen, Munich (Germany); Spandorfer, Adam; Varga-Szemes, Akos [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC (United States); Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC (United States)

    2016-10-15

    Highlights: • Stress dual-energy sCTMPI offers the possibility to directly detect the presence of myocardial perfusion defects. • Stress dual-energy sCTMPI allows differentiating between reversible and fixed myocardial perfusion defects. • The combination of coronary CT angiography and dual-energy sCTMPI can improve the ability of CT to detect hemodynamically relevant coronary artery disease. - Abstract: Dual-energy CT (DECT) enables simultaneous use of two different tube voltages, thus different x-ray absorption characteristics are acquired in the same anatomic location with two different X-ray spectra. The various DECT techniques allow material decomposition and mapping of the iodine distribution within the myocardium. Static dual-energy myocardial perfusion imaging (sCTMPI) using pharmacological stress agents demonstrate myocardial ischemia by single snapshot images of myocardial iodine distribution. sCTMPI gives incremental values to coronary artery stenosis detected on coronary CT angiography (CCTA) by showing consequent reversible or fixed myocardial perfusion defects. The comprehensive acquisition of CCTA and sCTMPI offers extensive morphological and functional evaluation of coronary artery disease. Recent studies have revealed that dual-energy sCTMPI shows promising diagnostic accuracy for the detection of hemodynamically significant coronary artery disease compared to single-photon emission computed tomography, invasive coronary angiography, and cardiac MRI. The aim of this review is to present currently available DECT techniques for static myocardial perfusion imaging and recent clinical applications and ongoing investigations.

  18. [Lung perfusion studies after percutaneous closure of patent ductus arteriosus using the Amplatzer Duct Occluder in children].

    Science.gov (United States)

    Parra-Bravo, José Rafael; Apolonio-Martínez, Adriana; Estrada-Loza, María de Jesús; Beirana-Palencia, Luisa Gracia; Ramírez-Portillo, César Iván

    2015-01-01

    The closure of patent ductus arteriosus with multiple devices has been associated with a reduction in lung perfusion. We evaluated the pulmonary perfusion after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder device using perfusion lung scan. Thirty patients underwent successful percutaneous patent ductus arteriosus occlusions using the Amplatzer Duct Occluder device were included in this study. Lung perfusion scans were preformed 6 months after the procedure. Peak flow velocities and protrusion of the device were analyzed by Doppler echocardiography. A left lung perfusionductus arteriosus and the minimum and maximum diameter/length of the ductus arteriosus ratio were statistically significant in patients with abnormalities of lung perfusion. It was observed protrusion the device in 6 patients with a higher maximum flow rate in the left pulmonary artery. The left lung perfusion may be compromised after percutaneous closure of patent ductus arteriosus with the Amplatzer Duct Occluder. The increased flow velocity in the origin of the left pulmonary artery can be a poor indicator of reduction in pulmonary perfusion and can occur in the absence of protrusion of the device. Copyright © 2014 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  19. Impact of CT perfusion imaging on the assessment of peripheral chronic pulmonary thromboembolism: clinical experience in 62 patients

    Energy Technology Data Exchange (ETDEWEB)

    Le Faivre, Julien; Khung, Suonita; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [University of Lille, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Duhamel, Alain [University of Lille, Department of Biostatistics, Lille (France); Lamblin, Nicolas [University of Lille, Department of Cardiology, Cardiology Hospital, Lille (France)

    2016-11-15

    To evaluate the impact of CT perfusion imaging on the detection of peripheral chronic pulmonary embolisms (CPE). 62 patients underwent a dual-energy chest CT angiographic examination with (a) reconstruction of diagnostic and perfusion images; (b) enabling depiction of vascular features of peripheral CPE on diagnostic images and perfusion defects (20 segments/patient; total: 1240 segments examined). The interpretation of diagnostic images was of two types: (a) standard (i.e., based on cross-sectional images alone) or (b) detailed (i.e., based on cross-sectional images and MIPs). The segment-based analysis showed (a) 1179 segments analyzable on both imaging modalities and 61 segments rated as nonanalyzable on perfusion images; (b) the percentage of diseased segments was increased by 7.2 % when perfusion imaging was compared to the detailed reading of diagnostic images, and by 26.6 % when compared to the standard reading of images. At a patient level, the extent of peripheral CPE was higher on perfusion imaging, with a greater impact when compared to the standard reading of diagnostic images (number of patients with a greater number of diseased segments: n = 45; 72.6 % of the study population). Perfusion imaging allows recognition of a greater extent of peripheral CPE compared to diagnostic imaging. (orig.)

  20. Standardized perfusion value of the esophageal carcinoma and its correlation with quantitative CT perfusion parameter values

    Energy Technology Data Exchange (ETDEWEB)

    Djuric-Stefanovic, A., E-mail: avstefan@eunet.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Saranovic, Dj., E-mail: crvzve4@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Sobic-Saranovic, D., E-mail: dsobic2@gmail.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia); Masulovic, D., E-mail: draganmasulovic@yahoo.com [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Unit of Digestive Radiology (First University Surgical Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade (Serbia); Artiko, V., E-mail: veraart@beotel.rs [Faculty of Medicine, University of Belgrade, Belgrade (Serbia); Center of Nuclear Medicine, Clinical Center of Serbia, Belgrade (Serbia)

    2015-03-15

    Purpose: Standardized perfusion value (SPV) is a universal indicator of tissue perfusion, normalized to the whole-body perfusion, which was proposed to simplify, unify and allow the interchangeability among the perfusion measurements and comparison between the tumor perfusion and metabolism. The aims of our study were to assess the standardized perfusion value (SPV) of the esophageal carcinoma, and its correlation with quantitative CT perfusion measurements: blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) of the same tumor volume samples, which were obtained by deconvolution-based CT perfusion analysis. Methods: Forty CT perfusion studies of the esophageal cancer were analyzed, using the commercial deconvolution-based CT perfusion software (Perfusion 3.0, GE Healthcare). The SPV of the esophageal tumor and neighboring skeletal muscle were correlated with the corresponding mean tumor and muscle quantitative CT perfusion parameter values, using Spearman's rank correlation coefficient (r{sub S}). Results: Median SPV of the esophageal carcinoma (7.1; range: 2.8–13.4) significantly differed from the SPV of the skeletal muscle (median: 1.0; range: 0.4–2.4), (Z = −5.511, p < 0.001). The cut-off value of the SPV of 2.5 enabled discrimination of esophageal cancer from the skeletal muscle with sensitivity and specificity of 100%. SPV of the esophageal carcinoma significantly correlated with corresponding tumor BF (r{sub S} = 0.484, p = 0.002), BV (r{sub S} = 0.637, p < 0.001) and PS (r{sub S} = 0.432, p = 0.005), and SPV of the skeletal muscle significantly correlated with corresponding muscle BF (r{sub S} = 0.573, p < 0.001), BV (r{sub S} = 0.849, p < 0.001) and PS (r{sub S} = 0.761, p < 0.001). Conclusions: We presented a database of the SPV for the esophageal cancer and proved that SPV of the esophageal neoplasm significantly differs from the SPV of the skeletal muscle, which represented a sample of healthy

  1. Arterial spin labelling perfusion MRI of breast cancer using FAIR TrueFISP: Initial results

    International Nuclear Information System (INIS)

    Buchbender, S.; Obenauer, S.; Mohrmann, S.; Martirosian, P.; Buchbender, C.; Miese, F.R.; Wittsack, H.J.; Miekley, M.; Antoch, G.; Lanzman, R.S.

    2013-01-01

    Aim: To assess the feasibility of an unenhanced, flow-sensitive, alternating inversion recovery-balanced steady-state free precession (FAIR TrueFISP) arterial spin labelling (ASL) magnetic resonance imaging (MRI) technique for quantification of breast cancer perfusion. Materials and methods: Eighteen untreated breast tumour patients (mean age 53 ± 17 years, range 30–68 years) and four healthy controls (mean age 51 ± 14 years, range 33–68 years) were enrolled in this study and were imaged using a clinical 1.5 T MRI machine. Perfusion measurements were performed using a coronal single-section ASL FAIR TrueFISP technique in addition to a routine breast MRI examination. T1 relaxation time of normal breast parenchyma was determined in four healthy volunteers using the variable flip angle approach. The definitive diagnosis was obtained at histology after biopsy or surgery and was available for all patients. Results: ASL perfusion was successfully acquired in 13 of 18 tumour patients and in all healthy controls. The mean ASL perfusion of invasive ductal carcinoma tissue was significantly higher (88.2 ± 39.5 ml/100 g/min) compared to ASL perfusion of normal breast parenchyma (24.9 ± 12.7 ml/100 g/min; p < 0.05) and invasive lobular carcinoma (30.5 ± 4.3 ml/100 g/min; p < 0.05). No significant difference was found between the mean ASL perfusion of normal breast parenchyma and invasive lobular carcinoma tissue (p = 0.97). Conclusion: ASL MRI enables quantification of breast cancer perfusion without the use of contrast material. However, its impact on diagnosis and therapy management of breast tumours has to be evaluated in larger patient studies

  2. Clinical Evaluation of Brain Perfusion SPECT with Brodmann Areas Mapping in Early Diagnosis of Alzheimer's Disease.

    Science.gov (United States)

    Valotassiou, Varvara; Papatriantafyllou, John; Sifakis, Nikolaos; Tzavara, Chara; Tsougos, Ioannis; Psimadas, Dimitrios; Fezoulidis, Ioannis; Kapsalaki, Eftychia; Hadjigeorgiou, George; Georgoulias, Panagiotis

    2015-01-01

    Early diagnosis of Alzheimer's disease (AD) based on clinical criteria alone may be problematic, while current and future treatments should be administered earlier in order to be more effective. Thus, various disease biomarkers could be used for early detection of AD. We evaluated brain perfusion with 99mTc-HMPAO single photon emission computed tomography (SPECT) and Brodmann areas (BAs) mapping in mild AD using an automated software (NeuroGam) for the semi-quantitative evaluation of perfusion in BAs and the comparison with the software's normal database. We studied 34 consecutive patients with mild AD: 9 men, 25 women, mean age 70.9 ± 8.1 years, mean Mini-Mental State Examination 22.6 ± 2.5. BAs 25L, 25R, 38L, 38R, 28L, 28R, 36L, and 36R had the lower mean perfusion values, while BAs 31L, 31R, 19R, 18L, 18R, 17L, and 17R had the higher mean values. Compared with healthy subjects of the same age, perfusion values in BAs 25L, 25R, 28R, 28L, 36L, and 36R had the greatest deviations from the healthy sample, while the lowest deviations were found in BAs 32L, 32R, 19R, 24L, 17L, 17R, 18L, and 18R. A percentage of ≥94% of patients had perfusion values more than -2SDs below the mean of healthy subjects in BAs 38R, 38L, 36L, 36R, 23L, 23R, 22L, 44L, 28L, 28R, 25L, and 25R. The corresponding proportion was less than 38% for BAs 11L, 19R, 32L, 32R, 18L, 18R, 24L, and 17R. In conclusion, brain SPECT studies with automated perfusion mapping could be useful as an ancillary tool in daily practice, revealing perfusion impairments in early AD.

  3. Time and dose-related changes in lung perfusion after definitive radiotherapy for NSCLC

    DEFF Research Database (Denmark)

    Farr, Katherina P; Khalil, Azza A; Møller, Ditte S

    2018-01-01

    BACKGROUND AND PURPOSE: To examine radiation-induced changes in regional lung perfusion per dose level in 58 non-small-cell lung cancer (NSCLC) patients treated with intensity-modulated radiotherapy (IMRT). MATERIAL AND METHODS: NSCLC patients receiving chemo-radiotherapy (RT) of minimum 60 Gy we...

  4. Toxicity and Kinetics of (3H)Microcystin-LR in Isolated Perfused Rat Livers

    Science.gov (United States)

    1990-03-20

    with a Waters 490 multiwavelength detector, as described by Robinson et al. (1989). A C-18 column (Adsorbosphere HS, 4.6 x 250 mm, 5 Am, Alltech ...1988). The isolated perfused liver has several advantages over other model systems for the study of hepatotoxins. Unlike the in-vitro cell systems

  5. Application of a stir-tank bioreactor for perfusion culture and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-18

    Jan 18, 2010 ... The bioreactor we used could be an efficient cell culture system and demonstrates industrial potential. ... overcoming the harmful effects of browning have no conclusive .... solvent under reduced pressure, the ethanol extract liquids was re- ... was detected in the exhaust medium with a perfusion rate of more ...

  6. Microstructure oriented modelling of hierarchically perfused porous media for cerebral blood flow evaluation

    Czech Academy of Sciences Publication Activity Database

    Tonar, Z.; Kochová, P.; Cimrman, R.; Witter, K.; Janáček, Jiří; Rohan, V.

    2011-01-01

    Roč. 465, č. 2011 (2011), s. 286-289 ISSN 1013-9826. [International Conference on Materials Structure & Micromechanics of Fracture /6./. Brno, 28.06.2010-30.06.2010] Institutional research plan: CEZ:AV0Z50110509 Keywords : brain * perfusion * morphometry * microvessels * stereology * modelling Subject RIV: EA - Cell Biology

  7. Dynamic perfusion patterns in temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Dupont, Patrick; Paesschen, Wim van; Zaknun, John J.; Maes, Alex; Tepmongkol, Supatporn; Locharernkul, Chaichon; Vasquez, Silvia; Carpintiero, Silvina; Bal, C.S.; Dondi, Maurizio

    2009-01-01

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  8. Dynamic perfusion patterns in temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, Patrick; Paesschen, Wim van [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); Zaknun, John J. [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); University Hospital of Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Maes, Alex [KU Leuven/UZ Gasthuisberg, Nuclear Medicine, Medical Imaging Center and Neurology, Leuven (Belgium); AZ Groeninge, Nuclear Medicine, Kortrijk (Belgium); Tepmongkol, Supatporn; Locharernkul, Chaichon [Chulalongkorn University, Nuclear Medicine and Neurology, Bangkok (Thailand); Vasquez, Silvia; Carpintiero, Silvina [Fleni Instituto de Investigaciones Neurologicas, Nuclear Medicine, Buenos Aires (Argentina); Bal, C.S. [All India Institute of Medical Sciences, Nuclear Medicine, New Delhi (India); Dondi, Maurizio [International Atomic Energy Agency (IAEA), Nuclear Medicine Section, Division of Human Health, Wagramer Strasse 5, PO BOX 200, Vienna (Austria); Ospedale Maggiore, Nuclear Medicine, Bologna (Italy)

    2009-05-15

    To investigate dynamic ictal perfusion changes during temporal lobe epilepsy (TLE). We investigated 37 patients with TLE by ictal and interictal SPECT. All ictal injections were performed within 60 s of seizure onset. Statistical parametric mapping was used to analyse brain perfusion changes and temporal relationships with injection time and seizure duration as covariates. The analysis revealed significant ictal hyperperfusion in the ipsilateral temporal lobe extending to subcortical regions. Hypoperfusion was observed in large extratemporal areas. There were also significant dynamic changes in several extratemporal regions: ipsilateral orbitofrontal and bilateral superior frontal gyri and the contralateral cerebellum and ipsilateral striatum. The study demonstrated early dynamic perfusion changes in extratemporal regions probably involved in both propagation of epileptic activity and initiation of inhibitory mechanisms. (orig.)

  9. Comparison of Acupuncture Effect on Blood Perfusion between Needling Nonacupoint on Meridian and Needling Nonacupoint off Meridian

    Directory of Open Access Journals (Sweden)

    Wei-Bo Zhang

    2013-01-01

    Full Text Available To verify the ancient theory of rather missing the acupoint than missing the meridian, acupuncture at nonacupoint on meridian and acupuncture at nonacupoint off meridian were performed, respectively. The blood perfusion (BP on the calf around bladder meridian area was measured with a laser Doppler perfusion imager before, during, and after acupuncture. The whole scanning field was divided into seven subareas, and mean BP on each area was calculated. The ratio of mean BP between a subarea and a reference subarea was gotten, and then the change rate was calculated as ratio change rate (RCR. The results showed that RCR on bladder meridian area and around Chengshan (BL57 during or after acupuncture at nonacupoint on meridian was significantly higher than that at nonacupoint off meridian, which supports the ancient theory. Such differences may be attributable to some factors that can facilitate the signals transmission and produce a better acupuncture effect, such as richer nerve terminals, blood vessels, and mast cells which can produce stronger signals on the acupoints and the low hydraulic resistance channel along meridians which plays a role of signal transmitting channel to get a better effect of acupuncture.

  10. Long-term outdoor cultivation by perfusing spent medium for biodiesel production from Chlorella minutissima.

    Science.gov (United States)

    Oh, Sung Ho; Kwon, Min Chul; Choi, Woon Yong; Seo, Yong Chang; Kim, Ga Bin; Kang, Do Hyung; Lee, Shin Young; Lee, Hyeon Yong

    2010-08-01

    A unique perfusion process was developed to maintain high concentrations of marine alga, Chlorella minutissima. This method is based on recycling cells by continuous feeding with warm spent sea water from nuclear power plants, which has very similar properties as sea water. A temperature of at least 30 degrees C in a 200 L photo-bioreactor was maintained in this system by perfusion of the thermal plume for 80 days in the coldest season. The maximum cell concentration and total lipid content was 8.3 g-dry wt./L and 23.2 %, w/w, respectively, under mixotrophic conditions. Lipid production was found to be due to a partially or non-growth related process, which implies that large amounts of biomass are needed for a high accumulation of lipids within the cells. At perfusion rates greater than 1.5 L/h, the temperature of the medium inside the reactor was around 30 degrees C, which was optimal for cell growth. For this system, a perfusion rate of 2.8 L/h was determined to be optimal for maintaining rapid cell growth and lipid production during outdoor cultivation. It was absolutely necessary to maintain the appropriate perfusion rate so that the medium temperature was optimal for cell growth. In addition, the lipids produced using this process were shown to be feasible for biodiesel production since the lipid composition of C. minutissima grown under these conditions consisted of 17 % (w/w) of C(16) and 47% (w/w) of C(18). The combined results of this study clearly demonstrated that the discharged energy of the thermal plume could be reused to cultivate marine alga by maintaining a relatively constant temperature in an outdoor photo-bioreactor without the need for supplying any extra energy, which could allow for cheap production of biodiesel from waste energy. Copyright 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. High-resolution MRI for the quantitative evaluation of subendocardial and subepicardial perfusion under pharmalogical stress and at rest

    International Nuclear Information System (INIS)

    Ritter, C.O.; Savio, K. del; Brackertz, A.; Beer, M.; Hahn, D.; Koestler, H.

    2007-01-01

    Purpose: MR stress perfusion imaging of the heart allows the quantification of myocardial perfusion and the evaluation of myocardial perfusion reserve (MPR) and the ratio of subendocardial to subepicardial perfusion at rest and under adenosine stress. The aim of this study was to evaluate a high-resolution GRAPPA sequence for quantitative MR first pass perfusion imaging in healthy volunteers. Materials and Methods: First pass stress and rest perfusion studies were performed on 10 healthy volunteers using a 1.5 T MR scanner with a multislice SR-TrueFISP first pass perfusion sequence with a GRAPPA algorithm (acceleration factor 3) in prebolus technique and an image resolution of 1.8 x 1.8 mm. For the comparison group, we examined 12 different healthy volunteers with a standard first pass perfusion SR-TrueFISP sequence using a resolution of 2.7 x 3.3 mm. Myocardial contours were manually delineated followed by an automatic division of the myocardium into two rings with an equal thickness for the subendo- and subepicardial layer. Eight sectors per slice were evaluated using contamination and baseline correction. Results: Using the GRAPPA sequence, the ratio of subendo- to subepimyocardial perfusion was 1.18 ± 0.32 for the examination at rest. Under pharmacologically induced stress, the ratio was 1.08 ± 0.27. For the standard sequence the ratio was 1.15 ± 0.28 at rest and 1.11 ± 0.33 under stress. For the high resolution sequence higher mean values for the subendo- to subepimyocardial ratio were obtained with comparable standard deviations. The difference between the sequences was not significant. Conclusion: The evaluation of subendomyocardial and subepimyocardial perfusion is feasible with a high-resolution first pass perfusion sequence. The use of a higher resolution to avoid systematic error leads to increased image noise. However, no relevant reduction in the quantitative perfusion values under stress and at rest was able to be depicted. (orig.)

  12. Optimization of perfusion studies using Atropine

    International Nuclear Information System (INIS)

    Alvarado, A.N.; Valle, V.M.; Montoya, M.J.; Eskenazi, E.S.; Montiel, M.L.; Cueto, C.C.

    2002-01-01

    The studies of myocardial perfusion require an adequate stress; exercise or pharmacological. Every day, more pharmacological studies are performed, specially in some group of patients (women, AMI, etc). There some drugs that are used for this purpose, as adenosine and dobutamine. However, their cost and the lack of availability and infrastructure in our country do not allow there routinely use. We performed dipyridamol as a pharmacological stress, however in some patients there is a doubt regarding if the pharmacological effect was adequate. Atropine is a drug that is frequently used for different purpose and it is well know its tachycardic response. We present and alternative technique, using dipyridamol-atropine as a protocol of stress perfusion study. Our goal was to correlate the standard dipyridamol -thallium perfusion study and the dipyridamol -atropine-perfusion in patients with chronic coronary disease. We evaluated 6 patients (5 males) with stable angina and chronic coronary disease. A standard dipyridamol-thallium study was performed in all of them. Dipyridamole was administered intravenously at a rate of 0.14 mg/kg/min over 6 min for a total of 0.84 mg/kg body weight. Blood pressure, heart rate, EKG and symptoms were monitored before, during and after the pharmacological infusion. Two minutes after the infusion was completed, the radiotracer was injected intravenously. In the next 6 months, without any modification of the clinical situation (symptoms and therapy) a new dipyridamol study was performed, using 1 mg of atropine after the administration of dipyridamol. There were no differences in the collateral effects and we observed and average increase of 30% in the heart rate in relation with the study using dipyridamol alone. The addition of atropine to the standard dipyridamol perfusion study is safe, cheaper and improved the detection of perfusion defects in patients with coronary artery disease

  13. Cerebral perfusion imaging in HIV positive patients

    International Nuclear Information System (INIS)

    Kundley, Kshama; Chowdhury, D.; Lele, V.R.; Lele, R.D.

    1998-01-01

    Full text: Twelve human immunodeficiency virus (HIV) positive patients were studied by SPECT cerebral perfusion imaging 1 hour post injection of 15 mCi of 99m Tc-ECD under ideal conditions with a triple head gamma camera (Prism 3000 X P LEUHR), fanbeam collimators followed by Folstein Mini Mental Status Examination (FMMSE) and AIDS dementia complex (ADC) staging on the same day. All 12 patients were male, in the age range of 23-45 y (mean 31 y). The infected status was diagnosed by ELISA (10 patients) or Western blot (5 patients). The interval between diagnosis and imaging ranged from 1 month - 35 months (mean 15.3 months). Two patients were alcoholic and 2 were smokers. None of them had CNS disorder clinically. ADC staging and FMMSE could be performed in 4 patients. Two patients were normal (stage 0) and 2 were subclinical (stage 0.5) on ADC staging. FMMSE revealed normal or near normal status (mean score 35; maximum score 36). Cerebral perfusion images were interpreted simultaneously by 3 observers blind towards history and examination using semi-quantitative and quantitative methods by consensus. It revealed multiple areas of hypoperfusion, viz. temporal (11 patients (91 %), parietal 10 patients (83%), frontal 9 patients (75%, pre and post central gyrus 7 patients (58%), occipital 6 patients (50%) cingulate gyrus and cerebellum 5 patients (41%) and thalamic in 2 patients (16%). Hyper perfusion in caudate nuclei was noted in 10 patients (83%). The study reveals presence of multiple perfusion abnormalities on cerebral perfusion imaging in HIV positive patients who have normal/near normal mental status suggesting precedence of perfusion abnormality over clinically apparent mental deficit

  14. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    International Nuclear Information System (INIS)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae

    2005-01-01

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 ± 8.5%, range:3 ∼ 35%) and mild to moderate severity (-71 ± 42.7%, range:-217 ∼ -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome

  15. Abnormal perfusion on myocardial perfusion SPECT in patients with Wolff-Parkinson-White syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young; Cha, Kwang Soo; Han, Seung Ho; Park, Tae Ho; Kim, Moo Hyun; Kim, Young Dae [Donga University College of Medicine, Busan (Korea, Republic of)

    2005-02-15

    Abnormal myocardial perfusion may be caused by ventricular preexcitation, but its location, extent, severity and correlation with accessory pathway (AP) are not established. We evaluated perfusion patterns on myocardial perfusion SPECT and location of AP in patients with WPW (Wolff-Parkison-White) syndrome. Adenosine Tc-99m MIBI or Tl-201 myocardial perfusion SPECT was performed in 11 patients with WPW syndrome. Perfusion defects (PD) were compared to AP location based on ECT with Fitzpatrick's algorithm of electrophysiologic study and radiofrequency catheter ablation. Patients had atypical chest discomfort or no symptom. Risk of coronary artery disease (CAD) was below 0.1 in 11 patients using the nomogram to estimate the probability of CAD. Coronary angiography was performed in 4 patients(mid-LAD 50% in one, normal in others). In 4 patients, AP localization was done by electrophysiologic study and radiofrequency catheter ablation (RFCA). Small to large extent (11.0 {+-} 8.5%, range:3 {approx} 35%) and mild to moderate severity (-71 {+-} 42.7%, range:-217 {approx} -39%) of reversible (n=9) or fixed (n=1) perfusion defects were noted. One patients with right free wall (right lateral) AP showed normal. PD locations were variable following the location of AP. One patient with left lateral wall AP was followed 6 weeks after RFCA and showed significantly decreased PD on SPECT with successful ablation. Myocardial perfusion defect showed variable extent, severity and location in patients with WPW syndrome. Abnormal perfusion defect showed in most of all patients, but if did not seem to be correlated specifically with location of accessory pathway and coronary artery disease. Therefore myocardial perfusion SPECT should be interpreted carefully in patients with WPW syndrome.

  16. Higher proliferation of peritumoral endothelial cells to IL-6/sIL-6R than tumoral endothelial cells in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Zhuang, Peng-Yuan; Wang, Jian-Dong; Tang, Zhao-Hui; Zhou, Xue-Ping; Quan, Zhi-Wei; Liu, Ying-Bin; Shen, Jun

    2015-01-01

    This study aimed to explore the responses to the interleukin-6 (IL-6)/soluble interleukin-6 receptor (sIL-6R) complex in peritumoral endothelial cells (PECs) and tumor endothelial cells (TECs), as well as determine the signaling pathways in the angiogenesis of hepatocellular carcinoma (HCC). The expression of IL-6, IL-6R, gp130, CD68, HIF-1α, and microvessel density (MVD) were assessed with an orthotopic xenograft model in nude mice. ECs were incubated under hypoxic conditions to detect IL-6 and gp130. The proliferation of PECs and TECs in the presence of IL-6 and sIL-6R, as well as the expression of gp130, JAK2/STAT3, PI3K/AKT in endothelial cells were measured. Peritumoral IL-6, IL-6R, gp130, CD68, and HIF-1α expression, as well as MVD, gradually increased during tumor growth. Hypoxia could directly induce IL-6 expression, but not gp130 in PECs. The co-culture of IL-6/sIL-6R induced much higher PEC proliferation and gp130 expression, as well as the elevated phosphorylation of JAK2 and STAT3, however not the phosphorylation of PI3K and AKT. PECs exhibited higher proliferation in response to IL-6/sIL-6R co-treatment compared with TECs in HCC via the up-regulation of gp130 /JAK2/STAT3. PEC and its associated peritumoral angiogenesis microenvironment may be a potential novel target for anti-angiogenic treatment. The online version of this article (doi:10.1186/s12885-015-1763-2) contains supplementary material, which is available to authorized users

  17. NMR study of damage on isolated perfused rat heart exposed to ischemia and hypoxia

    International Nuclear Information System (INIS)

    Luo Xuechun; Yan Yongbin; Zhang Riqing; Fan Lili

    2001-01-01

    Myocardial ischemia is the most common and primary cause of myocardium damage. Numerous conventional techniques and methods have been developed for ischemia and reperfusion studies. However, because of damage to the heart sample, most of these techniques can not be used to continuously monitor the full dynamic course of the myocardial metabolic pathway. The nuclear magnetic resonance (NMR) surface coil technique, which overcomes the limitations of conventional instrumentation, can be used to quantitatively study every stage of the perfused heart (especially after perfusion stoppage) continuously, dynamically, and without damage under normal or designed physiological conditions at the molecular level. In this paper, 31 P-NMR was used to study the effects of ischemia and hypoxia on isolated perfused hearts. The results show that complete hypoxia caused more severe functional damage to the myocardial cells than complete ischemia

  18. Optimal Homogenization of Perfusion Flows in Microfluidic Bio-Reactors: A Numerical Study

    DEFF Research Database (Denmark)

    Okkels, Fridolin; Dufva, Martin; Bruus, Henrik

    2011-01-01

    In recent years, the interest in small-scale bio-reactors has increased dramatically. To ensure homogeneous conditions within the complete area of perfused microfluidic bio-reactors, we develop a general design of a continually feed bio-reactor with uniform perfusion flow. This is achieved...... by introducing a specific type of perfusion inlet to the reaction area. The geometry of these inlets are found using the methods of topology optimization and shape optimization. The results are compared with two different analytic models, from which a general parametric description of the design is obtained...... and tested numerically. Such a parametric description will generally be beneficial for the design of a broad range of microfluidic bioreactors used for, e. g., cell culturing and analysis and in feeding bio-arrays....

  19. Analysis of perfusion weighted image of CNS lymphoma

    International Nuclear Information System (INIS)

    Lee, In Ho; Kim, Sung Tae; Kim, Hyung-Jin; Kim, Keon Ha; Jeon, Pyoung; Byun, Hong Sik

    2010-01-01

    Purpose: It is difficult to differentiate CNS lymphoma from other tumors such as malignant gliomas, metastases, or meningiomas with conventional MR imaging, because the imaging findings are overlapped between these tumors. The purpose of this study is to investigate the perfusion weighted MR imaging findings of CNS lymphomas and to compare the relative cerebral blood volume ratios between CNS lymphomas and other tumors such as high grade gliomas, metastases, or meningiomas. Materials and methods: We retrospectively reviewed MRI findings and clinical records in 13 patients with pathologically proven CNS lymphoma between January 2006 and November 2008. We evaluated the relative cerebral blood volume ratios of tumor, which were obtained by dividing the values obtained from the normal white matter on MRI. Results: Total 13 patients (M:F = 8:5; age range 46-67 years, mean age 52.3 years) were included. The CNS lymphomas showed relatively low values of maximum relative CBV ratio in most patients regardless of primary or secondary CNS lymphoma. Conclusion: Perfusion weighted image may be helpful in the diagnosis of CNS lymphoma in spite of primary or secondary or B cell or T cell.

  20. The effect of patent ductus arteriosus on pre-ductal and post-ductal perfusion index in preterm neonates.

    Science.gov (United States)

    Nitzan, Itamar; Hammerman, Cathy; Fink, Daniel; Nitzan, Meir; Koppel, Robert; Bromiker, Ruben

    2018-06-26

    The ductus arteriosus is a blood vessel that connects the pulmonary artery to the descending aorta during fetal life and generally undergoes spontaneous closure shortly after birth. In premature neonates it often fails to close (patent ductus arteriosus - PDA), which can result in diversion of a significant part of the left-ventricular cardiac output to the pulmonary circulation. This left-to-right shunt may result in significant increase of pulmonary blood flow and decrease of systemic perfusion (hemodynamically significant PDA - hsPDA), which may lead to severe neonatal morbidity. The study objective was to find the relationship between hsPDA and perfusion index (PI), a photoplethysmographic parameter, related to systemic perfusion. Approach. PI measures the relative systolic increase in tissue light absorption due to the systolic increase in the tissue blood volume. PI has been found to be directly related to tissue perfusion, and is therefore expected to be affected by hsPDA. Main results. PI was found to be higher in preterm neonates with hsPDA after first week of life, in comparison to those with closed DA, despite the lower systemic perfusion, probably due to reverse flow during diastole. Significance. In our study, perfusion index increased despite the lower systemic perfusion, indicating that in neonates with hsPDA, perfusion index is not necessarily a measure of perfusion. Nevertheless, PI can be used as a screening tool for suspicious PDA, in order to select a relatively small group of neonates for a more definitive examination by echocardiography, which is not suitable for universal screening. . © 2018 Institute of Physics and Engineering in Medicine.

  1. Quantitative dual energy CT measurements in rabbit VX2 liver tumors: Comparison to perfusion CT measurements and histopathological findings

    International Nuclear Information System (INIS)

    Zhang, Long Jiang; Wu, Shengyong; Wang, Mei; Lu, Li; Chen, Bo; Jin, Lixin; Wang, Jiandong; Larson, Andrew C.; Lu, Guang Ming

    2012-01-01

    Purpose: To evaluate the correlation between quantitative dual energy CT and perfusion CT measurements in rabbit VX2 liver tumors. Materials and methods: This study was approved by the institutional animal care and use committee at our institution. Nine rabbits with VX2 liver tumors underwent contrast-enhanced dual energy CT and perfusion CT. CT attenuation for the tumors and normal liver parenchyma and tumor-to-liver ratio were obtained at the 140 kVp, 80 kVp, average weighted images and dual energy CT iodine maps. Quantitative parameters for the viable tumor and adjacent liver were measured with perfusion CT. The correlation between the enhancement values of the tumor in iodine maps and perfusion CT parameters of each tumor was analyzed. Radiation dose from dual energy CT and perfusion CT was measured. Results: Enhancement values for the tumor were higher than that for normal liver parenchyma at the hepatic arterial phase (P < 0.05). The highest tumor-to-liver ratio was obtained in hepatic arterial phase iodine map. Hepatic blood flow of the tumor was higher than that for adjacent liver (P < 0.05). Enhancement values of hepatic tumors in the iodine maps positively correlated with permeability of capillary vessel surface (r = 0.913, P < 0.001), hepatic blood flow (r = 0.512, P = 0.010), and hepatic blood volume (r = 0.464, P = 0.022) at the hepatic arterial phases. The effective radiation dose from perfusion CT was higher than that from DECT (P < 0.001). Conclusions: The enhancement values for viable tumor tissues measured in iodine maps were well correlated to perfusion CT measurements in rabbit VX2 liver tumors. Compared with perfusion CT, dual energy CT of the liver required a lower radiation dose.

  2. Meta-Analysis of Stress Myocardial Perfusion Imaging

    Science.gov (United States)

    2017-06-06

    Coronary Disease; Echocardiography; Fractional Flow Reserve, Myocardial; Hemodynamics; Humans; Magnetic Resonance Imaging; Myocardial Perfusion Imaging; Perfusion; Predictive Value of Tests; Single Photon Emission Computed Tomography; Positron Emission Tomography; Multidetector Computed Tomography; Echocardiography, Stress; Coronary Angiography

  3. The clinical application of SPECT myocardial perfusion imaging with 99mTc-MIBI

    International Nuclear Information System (INIS)

    Dong Weiyu

    1992-01-01

    This paper reported 182 SPECT myocardial perfusion images with China made 99m Tc-MIBI and were compared with ECG and UCG. The sensitivity of SPECT in ischemic were 91.2% and was higher than ECG (74.9%)and UCG (61.8%) (P < 0.01). And its specificity, accuracy and positive predictive rate were 78.3%, 90% and 97% respectively. Besides 9 cases have reverse distribution after exercise and rest images. In some ICD patients had shown their SPECT images, the perfusion defects in exercise as well as in rest image

  4. Effects of smoking on lung uptake of 201Tl during exercise myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Ouyang Wei; He Guorong; Liu Jinhua

    2004-01-01

    Objective: To investigate the influence of smoking on lung uptake of 201 Tl during myocardial perfusion imaging. Methods: Ninety-two healthy subjects, with normal 201 Tl myocardial perfusion imaging findings but no evidence of left ventricular hypertrophy and pulmonary disease, were divided into three groups, smoker, nonsmoker and quitted smoker groups. Exercise/delay 201 Tl myocardial perfusion imaging was performed on all subjects included. Lung/heart ratio was defined on the anterior planar image obtained during exercise tomography. Results: Both the lung/heart ratios during exercise in smoker (0.40 ± 0.07, F=10.635, P 201 Tl lung/heart ratios in smokers are higher than in nonsmokers and this must be kept in mind when 201 Tl lung/heart ratios are used clinically, even in quitted smokers

  5. Study of a new method for the evaluation of portal vein pressure by hepatic perfusion imaging

    International Nuclear Information System (INIS)

    Cheng Muhua; Ling Yunbiao; Pan Zhiheng; Zhang Feng; Chen Weizhen

    2002-01-01

    To study a new method for predication of portal vein pressure (PVP) by hepatic perfusion imaging. 25 hepato-cirrhotic cases and 13 normal controls were performed the hepatic perfusion imaging. According to two compartmental model the values of portal vein indexes (PVI) was calculated using curve slope, area and hepatic heart perfusion ratio methods etc. The relationship of PVI with different method to PVP was also observed. All PVI by three methods in hepatocirrhosis were higher than those in normal controls (P<0.01), and also positively correlated with the PVP, their correlated coefficients was 0.79, 0.60, 0.68 respectively. Among them the slope method was most markedly significant than normal control and closely correlated with PVP. PVI can sensitively reflect the changes of portal vein blood flow. And it was an atraumatic, simple method for the evaluation of PVP

  6. Improved visualization of delayed perfusion in lung MRI

    International Nuclear Information System (INIS)

    Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

    2011-01-01

    Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S n,max /τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

  7. Application of CT perfusion imaging in radiotherapy for lung cancer

    International Nuclear Information System (INIS)

    Xia Guangrong; Liu Guimei; He Wen; Jin Guohua; Xie Ruming; Xu Yongxiang; Li Xiaobo; Li Xuebing

    2011-01-01

    Objective: To investigate the value of CT perfusion imaging in evaluation of therapeutic effect and prognosis in radiotherapy for lung cancer. Methods: Fifty-one cases of lung cancer who were unable or refused to be operated on, 36 males and 15 females, aged 37-80, underwent CT perfusion imaging, 29 of which only before radiotherapy and 22 before and after radiotherapy twice. The images were collected by cine dynamic scanning (5 mm/4 slices) and input into the GE AW4.0 workstation for data processing. The slice positions of CT imaging were determined according to the largest tumor size in CT scan. Regions of interest of tumor were drawn at the region corresponding to the original images of CT perfusion. Radiotherapy was performed after CT perfusion imaging. Relevant parameters, including blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface (PS) were calculated. The treatment response after radiotherapy was evaluated by RECIST. At 2 -4 weeks after the treatment, CT examination was conducted once more. Results: The tests of the 51 patients showed that the BV was 13.6 ml·100 g -1 , the BF was 129.5 ml·min -1 ·100 g -1 , the MTT was 9.1 s, and the PS was 10.0 ml· min -1 · 100 g -1 before radiotherapy. The tests of the 22 of the 51 patients showed that the values of BV and BF after radiotherapy were 7.6 ml· 100 g -1 and 97.8 ml·min -1 · 100 g -1 , respectively, both lower than those before radiotherapy (11.2 and 108.7 ml·min -1 ·100 g -1 , respectively), however, both not significantly (t=1.28, 0.40, P>0.05); and the values of MTT and PS after radiotherapy were 8.9 s and 7.8 ml·min -1 · 100 g -1 , respectively, both not significantly higher than those before radiotherapy (7.2 s and 6.8 ml· min -1 · 100 g -1 , respectively, t=-1.15, -0.57, P>0.05). The mean area of tumor after radiotherapy was 1189.6 mm 2 , significantly less than that before radiotherapy (1920.3 mm 2 , t=3.98, P<0.05). The MTT of the SCLC patients was 12

  8. Automatic Detection of Myocardial Boundaries in MR Cardio Perfusion Images

    NARCIS (Netherlands)

    Spreeuwers, Luuk; Breeuwer, Marcel

    2001-01-01

    Cardiovascular diseases often result in reduced blood perfusion of the myocardium (MC). Recent advances in MR allow fast recordingof contrast enhanced myocardial perfusion scans. For perfusion analysis the myocardial boundaries must be traced. Currently this is done manually. In this paper a method

  9. Assessment of relationship between regional perfusion and ventricular function in patients with severely depressed ejection fraction

    International Nuclear Information System (INIS)

    Teresinska, A.; Konieczna, S.; Szumilak, B.; Gosiewska-Marcinkowska, E.; Potocka, J.

    1998-01-01

    Patients with low ventricular (LV) ejection fraction (EF) and with regional or global LV dysfunction, considered for myocardial revascularization, are often submitted to myocardial perfusion study to ptrove perfusion preserved and to approximate viability. The aim of this work is to evaluate, to what extent SPECT with Tc-99m-MIBI (SPECT-MIBI) additionally differentiatesa and enlarges the information on LV contractility achieved from radioisotopic ventriculography (RNV). Seventy-three patients with EF=0.11-0.35 (mean: 0.26 ± 0.06, calculated from RNV) were studied. Planar gated RNV and SPECT-MIBI were performed within 2 months (mean: 15 ± 14 days). RNV, after in vivo red cells labeling with Tc-99m, was recorded in rest in LAO45 and RAO30 views. Global EF and contractility of 5 regions (anterior, posterior, lateral walls, septum and apex) were evaluated. Assessment was performed by means of LV in 'cine' mode,m ED and ES outlines and amplitude-phase images. Regional contractility abnormalities were classified as dyskinesis, akinesis and hypokinesis. SPECT-MIBI was performed in rest and stress. Perfusion abnormalities in 5 above mentioned regions was classified as large (more intense than 50% of myocardial maximum) or small persistent defects (DEFpers), large or small partially reversible defects (DEFpart-rev), large or small completely reversible defects (DEFrev). Hypokinesis was detected in 23-35 regions (65%) , dyskinesis - in 63 (17%), akinesis - in 37 (10%), normokinesis - in 27 (7%). In dyskinetic regions, there existed large DEFpers (79%) or large DEFpart-rev (21%). In akinetic regions, there also existed large DEFpers (68%) or large DEFpart-rev (32%). In hypokinetic regions, there were no perfusion defects (31% of regions), small DEFpers, DEFrev and DEFpart-rev (42%) and also large DEFpers (27%). In most of normokinetic regions, different types of perfusion defects were observed (large DEFpers existed in 26% of regions). In summary: In dyskinetic and akinetic

  10. Effect of nutritional status on oxidative stress in an ex vivo perfused rat liver.

    Science.gov (United States)

    Stadler, Michaela; Nuyens, Vincent; Seidel, Laurence; Albert, Adelin; Boogaerts, Jean G

    2005-11-01

    Normothermic ischemia-reperfusion is a determinant in liver injury occurring during surgical procedures, ischemic state, and multiple organ failure. The preexisting nutritional status of the liver might contribute to the extent of tissue injury and primary nonfunction. The aim of this study was to determine the role of starvation on hepatic ischemia-reperfusion injury in normal rat livers. Rats were randomly divided into two groups: one had free access to food, the other was fasted for 16 h. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Two modes of perfusion were applied in each series of rats, fed and fasting. In the ischemia-reperfusion mode, the experiment consisted of perfusion for 15 min, warm ischemia for 60 min, and reperfusion during 60 min. In the nonischemia mode, perfusion was maintained during the 135-min study period. Five rats were included in each experimental condition, yielding a total of 20 rats. Liver enzymes, potassium, glucose, lactate, free radicals, i.e., dienes and trienes, and cytochrome c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in tissue biopsies. Transaminases, lactate dehydrogenase, potassium, and free radical concentrations were systematically higher in fasting rats in both conditions, with and without ischemia. Cytochrome c was higher after reperfusion in the fasting rats. Glucose and lactate concentrations were greater in the fed group. The glycogen content decreased in both groups during the experiment but was markedly lower in the fasting rats. In fed rats, liver injury was moderate, whereas hepatocytes integrity was notably impaired both after continuous perfusion and warm ischemia in fasting animals. Reduced glycogen store in hepatocytes may explain reduced tolerance.

  11. Anodic biofilms in microbial fuel cells harbor low numbers of higher-power-producing bacteria than abundant genera

    Energy Technology Data Exchange (ETDEWEB)

    Kiely, Patrick D.; Call, Douglas F.; Yates, Matthew D.; Regan, John M.; Logan, Bruce E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Civil and Environmental Engineering

    2010-09-15

    Microbial fuel cell (MFC) anode communities often reveal just a few genera, but it is not known to what extent less abundant bacteria could be important for improving performance. We examined the microbial community in an MFC fed with formic acid for more than 1 year and determined using 16S rRNA gene cloning and fluorescent in situ hybridization that members of the Paracoccus genus comprised most ({proportional_to}30%) of the anode community. A Paracoccus isolate obtained from this biofilm (Paracoccus denitrificans strain PS-1) produced only 5.6 mW/m{sup 2}, whereas the original mixed culture produced up to 10 mW/m{sup 2}. Despite the absence of any Shewanella species in the clone library, we isolated a strain of Shewanella putrefaciens (strain PS-2) from the same biofilm capable of producing a higher-power density (17.4 mW/m{sup 2}) than the mixed culture, although voltage generation was variable. Our results suggest that the numerical abundance of microorganisms in biofilms cannot be assumed a priori to correlate to capacities of these predominant species for high-power production. Detailed screening of bacterial biofilms may therefore be needed to identify important strains capable of high-power generation for specific substrates. (orig.)

  12. Anodic biofilms in microbial fuel cells harbor low numbers of higher-power-producing bacteria than abundant genera

    KAUST Repository

    Kiely, Patrick D.; Call, Douglas F.; Yates, Matthew D.; Regan, John M.; Logan, Bruce E.

    2010-01-01

    Microbial fuel cell (MFC) anode communities often reveal just a few genera, but it is not known to what extent less abundant bacteria could be important for improving performance. We examined the microbial community in an MFC fed with formic acid for more than 1 year and determined using 16S rRNA gene cloning and fluorescent in situ hybridization that members of the Paracoccus genus comprised most (~30%) of the anode community. A Paracoccus isolate obtained from this biofilm (Paracoccus denitrificans strain PS-1) produced only 5.6 mW/m 2, whereas the original mixed culture produced up to 10 mW/m 2. Despite the absence of any Shewanella species in the clone library, we isolated a strain of Shewanella putrefaciens (strain PS-2) from the same biofilm capable of producing a higher-power density (17.4 mW/m2) than the mixed culture, although voltage generation was variable. Our results suggest that the numerical abundance of microorganisms in biofilms cannot be assumed a priori to correlate to capacities of these predominant species for high-power production. Detailed screening of bacterial biofilms may therefore be needed to identify important strains capable of high-power generation for specific substrates. © 2010 Springer-Verlag.

  13. Anodic biofilms in microbial fuel cells harbor low numbers of higher-power-producing bacteria than abundant genera

    KAUST Repository

    Kiely, Patrick D.

    2010-07-15

    Microbial fuel cell (MFC) anode communities often reveal just a few genera, but it is not known to what extent less abundant bacteria could be important for improving performance. We examined the microbial community in an MFC fed with formic acid for more than 1 year and determined using 16S rRNA gene cloning and fluorescent in situ hybridization that members of the Paracoccus genus comprised most (~30%) of the anode community. A Paracoccus isolate obtained from this biofilm (Paracoccus denitrificans strain PS-1) produced only 5.6 mW/m 2, whereas the original mixed culture produced up to 10 mW/m 2. Despite the absence of any Shewanella species in the clone library, we isolated a strain of Shewanella putrefaciens (strain PS-2) from the same biofilm capable of producing a higher-power density (17.4 mW/m2) than the mixed culture, although voltage generation was variable. Our results suggest that the numerical abundance of microorganisms in biofilms cannot be assumed a priori to correlate to capacities of these predominant species for high-power production. Detailed screening of bacterial biofilms may therefore be needed to identify important strains capable of high-power generation for specific substrates. © 2010 Springer-Verlag.

  14. Dynamic CT of portal hypertensive gastropathy: significance of transient gastric perfusion defect sign

    International Nuclear Information System (INIS)

    Kim, T.U.; Kim, S.; Woo, S.K.; Lee, J.W.; Lee, T.H.; Jeong, Y.J.; Heo, J.

    2008-01-01

    Aim: To evaluate the 'transient gastric perfusion defect' sign as a way of diagnosing portal hypertensive gastropathy (PHG) on multidetector computed tomography (CT). Materials and methods: Ninety-two consecutive patients with cirrhosis underwent three-phase CT and endoscopy. Endoscopy was performed within 3 days of the CT examination. As controls, 92 patients without clinical evidence of chronic liver diseases who underwent CT and endoscopy were enrolled; the findings at endoscopy were used as a reference standard for patients with PHG. Two radiologists who were unaware of the results of the endoscopy retrospectively interpreted the CT images. PHG was diagnosed on dynamic CT if the transient gastric perfusion defect sign was present. The transient gastric perfusion defect was defined as the presence of transient, segmental or subsegmental hypo-attenuating mucosa in the fundus or body of the stomach on hepatic arterial imaging that returned to normal attenuation on portal venous or equilibrium-phase imaging. The frequency of the transient gastric perfusion defect sign was compared between these two groups using Fisher's exact test. The frequency, sensitivity, specificity, positive predictive values, and negative predictive values of the transient gastric perfusion defect sign were also compared between patients with PHG and without PHG in the cirrhosis group. Results: Nine patients of 92 patients with cirrhosis were excluded because of previous procedure or motion artifact; the remaining 83 patients with cirrhosis were evaluated. In the cirrhosis group, 40 (48.1%) of 83 patients showed the transient gastric perfusion defect sign. In the control group, none of the 92 patients showed the transient gastric perfusion defect sign. In the cirrhotic group, the frequency of the transient gastric perfusion defect sign was significantly higher in the patients with PHG (75%, 36/48) than in patients without PHG (11.4%, 4/35). The sensitivity, specificity, positive predictive

  15. Human leucocyte antigen class I-redirected anti-tumour CD4+ T cells require a higher T cell receptor binding affinity for optimal activity than CD8+ T cells.

    Science.gov (United States)

    Tan, M P; Dolton, G M; Gerry, A B; Brewer, J E; Bennett, A D; Pumphrey, N J; Jakobsen, B K; Sewell, A K

    2017-01-01

    CD4 + T helper cells are a valuable component of the immune response towards cancer. Unfortunately, natural tumour-specific CD4 + T cells occur in low frequency, express relatively low-affinity T cell receptors (TCRs) and show poor reactivity towards cognate antigen. In addition, the lack of human leucocyte antigen (HLA) class II expression on most cancers dictates that these cells are often unable to respond to tumour cells directly. These deficiencies can be overcome by transducing primary CD4 + T cells with tumour-specific HLA class I-restricted TCRs prior to adoptive transfer. The lack of help from the co-receptor CD8 glycoprotein in CD4 + cells might result in these cells requiring a different optimal TCR binding affinity. Here we compared primary CD4 + and CD8 + T cells expressing wild-type and a range of affinity-enhanced TCRs specific for the HLA A*0201-restricted NY-ESO-1- and gp100 tumour antigens. Our major findings are: (i) redirected primary CD4 + T cells expressing TCRs of sufficiently high affinity exhibit a wide range of effector functions, including cytotoxicity, in response to cognate peptide; and (ii) optimal TCR binding affinity is higher in CD4 + T cells than CD8 + T cells. These results indicate that the CD4 + T cell component of current adoptive therapies using TCRs optimized for CD8 + T cells is below par and that there is room for substantial improvement. © 2016 The Authors. Clinical & Experimental Immunology published by John Wiley & Sons Ltd on behalf of British Society for Immunology.

  16. Study of lung perfusion in colagenosis

    International Nuclear Information System (INIS)

    Macedo de Carvalho, A.C.; Calegaro, J.U.M.

    1982-01-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized. (author) [es

  17. Methodology for ventilation/perfusion SPECT

    DEFF Research Database (Denmark)

    Bajc, Marika; Neilly, Brian; Miniati, Massimo

    2010-01-01

    Ventilation/perfusion single-photon emission computed tomography (V/Q SPECT) is the scintigraphic technique of choice for the diagnosis of pulmonary embolism and many other disorders that affect lung function. Data from recent ventilation studies show that the theoretic advantages of Technegas ov...

  18. Study of lung perfusion in colagenosis

    Energy Technology Data Exchange (ETDEWEB)

    Macedo de Carvalho, A C; Calegaro, J U.M. [Fundacao Hospitalar do Distrito Federal, Distrito Federal (Brazil). Unidade de Medicina Nuclear

    1982-07-01

    The lung involvement in the various types of colagenosis has been widely described in the literature. However, the study of lung perfusion utilizing radionuclides has been only mentioned in a few papers. With the intention of ascertaining the importance of the lung perfusion scanning in colagenosis, ten cases were studied, seven of which were females and three males, with the following pathologies: 4 rheumatoid arthritis, 4 systemic lupus eritematosous, 1 scleroderma and 1 scleroderma plus dermatomyositis. The ages of the patients varied from 20 to 73 years, and the duration of the disease from 1 month to 39 years. The lung scanning showed perfusion defects in 100% of the cases, not related with the type of colagenosis, duration of the disease, sex or age. On the other hand, the X rays study showed alterations in only 2 patients (20% of the cases). The ventilatory and respiratory functions were tested on 7 patients showing alteration (mixed pattern with predominance of the restrictive factor) in only one (14.3%), while the other patients were normal (85.7%). The importance of the lung perfusion scanning study in all patients with collagen vascular diseases is emphasized.

  19. Nuclear cardiology: Myocardial perfusion and function

    International Nuclear Information System (INIS)

    Seldin, D.W.

    1991-01-01

    Myocardial perfusion studies continue to be a major focus of research, with new investigations of the relationship of exercise-redistribution thallium imaging to diagnosis, prognosis, and case management. The redistribution phenomenon, which seemed to be fairly well understood a few years ago, is now recognized to be much more complex than originally thought, and various strategies have been proposed to clarify the meaning of persistent defects. Pharmacologic intervention with dipyridamole and adenosine has become available as an alternative to exercise, and comparisons with exercise imaging and catheterization results have been described. Thallium itself is no longer the sole single-photon perfusion radiopharmaceutical; two new technetium agents are now widely available. In addition to perfusion studies, advances in the study of ventricular function have been made, including reports of studies performed in conjunction with technetium perfusion studies, new insights into cardiac physiology, and the prognostic and case-management information that function studies provide. Finally, work has continued with monoclonal antibodies for the identification of areas of myocyte necrosis. 41 references

  20. Perfusion Quantification Using Gaussian Process Deconvolution

    DEFF Research Database (Denmark)

    Andersen, Irene Klærke; Have, Anna Szynkowiak; Rasmussen, Carl Edward

    2002-01-01

    The quantification of perfusion using dynamic susceptibility contrast MRI (DSC-MRI) requires deconvolution to obtain the residual impulse response function (IRF). In this work, a method using the Gaussian process for deconvolution (GPD) is proposed. The fact that the IRF is smooth is incorporated...

  1. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    International Nuclear Information System (INIS)

    Meeder, J.G.; Blanksma, P.K.; Wall, E.E. van der; Anthonio, R.L.; Willemsen, A.T.M.; Pruim, J.; Vaalburg, W.; Lie, K.I.

    1996-01-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116±17 ml/min/100 g vs 96±20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02±0.15 vs 1.18±0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%±4.2% vs 13.5%±1.9%, P <0.05) and during cold pressor stimulation (17.0%±3.2% vs 13.9%±1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab

  2. Long-term cigarette smoking is associated with increased myocardial perfusion heterogeneity assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Meeder, J.G. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Blanksma, P.K. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Wall, E.E. van der [Department of Cardiology, University Hospital, Leiden (Netherlands); Anthonio, R.L. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Willemsen, A.T.M. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Pruim, J. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Vaalburg, W. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands); Lie, K.I. [Department of Cardiology and National Research PET Center, University Hospital, Groningen (Netherlands)

    1996-11-01

    The pathophysiology of smoking-related coronary events in patients with normal coronary arteries is incompletely understood. This study was conducted to explore, in subjects without symptoms of cardiovascular disease, the long-term effects of smoking on regional coronary artery vasoactivity, especially during sympathetic stimulation. In ten smoking and ten non-smoking sex- and age-matched healthy volunteers, segmental myocardial perfusion was studied using dynamic parametric nitrogen-13 ammonia positron emission tomography at rest and during sympathetic stimulation evoked by the cold pressor stimulation. Smokers demonstrated a higher myocardial perfusion at rest (116{+-}17 ml/min/100 g vs 96{+-}20 ml/min/100 g, P <0.01) and an impaired myocardial perfusion increase during cold pressor stimulation (1.02{+-}0.15 vs 1.18{+-}0.17, P <0.05). The heterogeneity of perfusion, expressed as coefficient of variation, was significantly different between the smoking and the non-smoking group. The coefficient of variation of segmental myocardial perfusion was higher in smokers at rest (17.5%{+-}4.2% vs 13.5%{+-}1.9%, P <0.05) and during cold pressor stimulation (17.0%{+-}3.2% vs 13.9%{+-}1.8%, P <0.05). We conclude that the long-term effects of smoking in healthy volunteers are associated with (1) increased myocardial perfusion at rest, (2) impaired myocardial perfusion response to cold pressor stimulation, and (3) increased myocardial perfusion heterogeneity both at rest and during cold pressor stimulation. These results may suggest that in healthy subjects the long-term effect of smoking is related to abnormal coronary artery vasoactivity, presumably induced by an interplay of regional endothelial dysfunction and autonomic dysregulation. (orig.). With 1 fig., 1 tab.

  3. Fundamental supply of skin blood flow in the Chinese Han population: Measurements by a full-field laser perfusion imager.

    Science.gov (United States)

    Fei, W; Xu, S; Ma, J; Zhai, W; Cheng, S; Chang, Y; Wang, X; Gao, J; Tang, H; Yang, S; Zhang, X

    2018-05-08

    Skin blood flow is believed to link with many diseases, and shows a significant heterogeneity. There are several papers on basal cutaneous microcirculation perfusion in different races, while the data in Chinese is vacant. The aim was to establish the database of absolute fundamental supply of skin blood flow in the Chinese Han population. With a full-field laser perfusion imager (FLPI), the skin blood flow can be quantified. Cutaneous perfusion values were determined in 17 selected skin areas in 406 healthy participants aged between 20 and 80 years (mean 35.05 ± 11.33). Essential parameters such as weight, height were also measured and values of BMI were calculated. The perfusion values were reported in Arbitrary Perfusion Units (APU). The highest cutaneous perfusion value fell on eyelid (931.20 ± 242.59 in male and 967.83 ± 225.49 in female), and pretibial had the lowest value (89.09 ± 30.28 in male and 85.08 ± 33.59 in female). The values were higher in men than women on the bank of fingertips, nose, forehead, cheek, neck and earlobe (P < .05). Perfusion values on stretch and flexion side of forearm had negative correlation with age (P = .01 and P = 4.88 × 10 -3 , respectively) in male. Abdomen was negatively correlated with BMI in both gender (P = .02, respectively). Skin blood flow values vary with skin regions. There is a tendency to measure higher perfusion values in men than in women. And the values are irrelevant with age or BMI. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Detectable perfusion changes in MAG3 studies

    International Nuclear Information System (INIS)

    Shuter, B.; Bernar, A.; Roach, P.

    1998-01-01

    Full text: The use of 120 MBq 99m Tc-MAG 3 instead of 600 MBq 99m Tc-DTPA in renal imaging has degraded the images obtained during the perfusion phase. An increase of the minimum detectable change (MDC) in blood flow (BF) would also be expected. In transplant patients, renal BF is an important factor in patient management and the MDC should be small to allow early detection of reduced perfusion. We determined the mean and coefficient of variation (CoV: standard deviation/mean) of three renal perfusion indices as a function of counts in the time-activity curves (TACs). Transplant patients were given a dose of about 300 MBq of 99m Tc-MAG3 and images acquired at 8 fps for 60s. TACs made up from 8, 4, 2 or I images per second allowed calculation of renal perfusion indices as if doses of 300, 150, 75 and 38 MBq had been administered. Perfusion indices based on area under the TACs up to the arterial peak (API), the maximum slopes of the TACs (SPI) and the maximum slope of renal TAC and height of arterial TAC (BPI) were calculated by our routine renal software package. As the administered dose decreased, the CoV rose for all indices, least for BPI and most for API. BPI CoV increased from ∼10% at 300 MBq to 20% at 75 MBq, but API CoV rose from 6% to 46%. Mean BPI was stable over the dose range, but mean API showed a systematic increase of about 50% over the 300 MBq result. We conclude that at 120 MBq the MDC (expressed as 2*CoV) in BF is 30-60%, whereas at 600 MBq it may be as low as 10%, allowing earlier confident detection of a change in BF. The BPI was the preferred perfusion index as its mean value changed little and it had the least CoV at lower activities. The data also imply that relative kidney perfusion in the one individual will be much less accurate with 120 MBq of MAG 3

  5. Insulin resistance is associated with lower arterial blood flow and reduced cortical perfusion in cognitively asymptomatic middle-aged adults

    Science.gov (United States)

    Hoscheidt, Siobhan M; Kellawan, J Mikhail; Berman, Sara E; Rivera-Rivera, Leonardo A; Krause, Rachel A; Oh, Jennifer M; Beeri, Michal S; Rowley, Howard A; Wieben, Oliver; Carlsson, Cynthia M; Asthana, Sanjay; Johnson, Sterling C; Schrage, William G

    2016-01-01

    Insulin resistance (IR) is associated with poor cerebrovascular health and increased risk for dementia. Little is known about the unique effect of IR on both micro- and macrovascular flow particularly in midlife when interventions against dementia may be most effective. We examined the effect of IR as indexed by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) on cerebral blood flow in macro- and microvessels utilizing magnetic resonance imaging (MRI) among cognitively asymptomatic middle-aged individuals. We hypothesized that higher HOMA-IR would be associated with reduced flow in macrovessels and lower cortical perfusion. One hundred and twenty cognitively asymptomatic middle-aged adults (57 ± 5 yrs) underwent fasting blood draw, phase contrast-vastly undersampled isotropic projection reconstruction (PC VIPR) MRI, and arterial spin labeling (ASL) perfusion. Higher HOMA-IR was associated with lower arterial blood flow, particularly within the internal carotid arteries (ICAs), and lower cerebral perfusion in several brain regions including frontal and temporal lobe regions. Higher blood flow in bilateral ICAs predicted greater cortical perfusion in individuals with lower HOMA-IR, a relationship not observed among those with higher HOMA-IR. Findings provide novel evidence for an uncoupling of macrovascular blood flow and microvascular perfusion among individuals with higher IR in midlife. PMID:27488909

  6. Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per

    2015-01-01

    Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

  7. Regional perfusion and oxygenation of tumors upon methylxanthine derivative administration

    International Nuclear Information System (INIS)

    Kelleher, Debra K.; Thews, Oliver; Vaupel, Peter

    1998-01-01

    Purpose: The use of methylxanthine derivatives has been postulated as a means of increasing tumor perfusion and thus ameliorating tumor hypoxia. The aim of this study was to quantify and compare the effects of three methylxanthine derivatives: pentoxifylline (PX), torbafylline (TB), and HWA 138 (HW) on tumor perfusion and oxygenation. Methods and Materials: Anesthetized Sprague Dawley rats with DS-sarcomas implanted subcutaneously onto the hind foot dorsum were used in this study. Mean arterial blood pressure (MABP) was measured throughout experiments. Regional red blood cell (RBC) flux was monitored using a multichannel laser Doppler device and tumor oxygenation on a more global level was assessed polarographically using an O 2 -sensitive catheter electrode. The methylxanthine derivatives were administered as a single dose intraperitoneally (for PX 50 mg/kg; for TB and HW 75 mg/kg). Results: Following drug administration, initial decreases in MABP down to 75% of baseline values were observed for all three substances. PX, HW, and TB caused initial transient reductions in mean RBC flux followed by gradual increases to values of 137 ± 27 %, 139 ± 14 %, and 122 ± 14 % respectively at t = 60 min. Following a small initial decrease upon drug administration, O 2 partial pressure (pO 2 ) rose to 160 ± 31 %, 153 ± 34 %, and 121 ± 11 % for PX, HW, and TB, respectively at t = 60 min. At the end of the observation period (t = 90 min), increases in RBC flux and pO 2 were still evident. When individual tumors were considered, a variety of patterns (including opposing effects) for changes in RBC flux were seen, not necessarily reflected in the mean values. Thus, while the methylxanthine derivatives caused an increased average tumor perfusion, there is evidence suggesting that a redistribution of tumor blood flow occurs which may amplify preexisting heterogeneity. Conclusions: Substantial improvements in tumor oxygenation and perfusion were observed after administration of

  8. Myocardial perfusion imaging by digital subtraction angiography

    International Nuclear Information System (INIS)

    Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

    1986-01-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

  9. Basic consideration of diffusion/perfusion imaging

    International Nuclear Information System (INIS)

    Tamagawa, Yoichi; Kimura, Hirohiko; Matsuda, Tsuyoshi; Kawamura, Yasutaka; Nakatsugawa, Shigekazu; Ishii, Yasushi; Sakuma, Hajime; Tsukamoto, Tetsuji.

    1990-01-01

    In magnetic resonance imaging (MRI), microscopic motion of biological system such as molecular diffusion of water and microcirculation of blood in the capillary network (perfusion) has been proposed to cause signal attenuation as an intravoxel incoherent motion (IVIM). Quantitative imaging of the IVIM phenomenon was attempted to generate from a set of spin-echo (SE) sequences with or without sensitization by motion probing gradient (MPG). The IVIM imaging is characterized by a parameter, apparent diffusion coefficient (ADC), which is an integration of both the diffusion and the perfusion factor on voxel-by-voxel basis. Hard ware was adjusted to avoid image artifact mainly produced by eddy current. Feasibility of the method was tested using bottle phantom filled with water at different temperature and acetone, and the calculated ADC values of these media corresponded well with accepted values of diffusion. The method was then applied to biological system to investigate mutual participation of diffusion/perfusion on the ADC value. The result of tumor model born on nude mouse suggested considerable participation of perfusion factor which immediately disappeared after sacrificing the animal. Meanwhile, lower value of sacrificed tissue without microcirculation was suggested to have some restriction of diffusion factor by biological tissue. To substantiate the restriction effect on the diffusion, a series of observation have made on a fiber phantom, stalk of celory with botanical fibers and human brain with nerve fibers, in applying unidirectional MPG along the course of these banch of fiber system. The directional restriction effect of diffusion along the course of fiber (diffusion anisotrophy) was clearly visualized as directional change of ADC value. The present method for tissue characterization by diffusion/perfusion on microscopic level will provide a new insight for evaluation of functional derangement in human brain and other organs. (author)

  10. Ventilation and perfusion display in a single image

    International Nuclear Information System (INIS)

    Lima, J.J.P. de; Botelho, M.F.R.; Pereira, A.M.S.; Rafael, J.A.S.; Pinto, A.J.; Marques, M.A.T.; Pereira, M.C.; Baganha, M.F.; Godinho, F.

    1991-01-01

    A new method of ventilation and perfusion display onto a single image is presented. From the data on regions of interest of the lungs, three-dimensional histograms are created, containing as parameters X and Y for the position of the pixels, Z for the perfusion and colour for local ventilation. The perfusion value is supplied by sets of curves having Z proportional to the local perfusion count rate. Ventilation modulates colour. Four perspective views of the histogram are simultaneously displayed to allow visualization of the entire organ. Information about the normal ranges for both ventilation and perfusion is also provided in the histograms. (orig.)

  11. Characteristics of Brain Perfusion in Patients of Parkinson's Disease

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Park, Min Jung; Kim, Jae Woo; Kang, Young Kang

    2008-01-01

    It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9±6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4±9.2 y/o) as normal controls who had no past illness history were performed 99m Tc-HMPAO brain perfusion SPECT and neuropsychological test. At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood

  12. Functional and perfusion magnetic resonance imaging at 3 tesla

    International Nuclear Information System (INIS)

    Klarhoefer, M.

    2001-03-01

    This thesis deals with the development and optimization of fast magnetic resonance imaging (MRI) methods for non-invasive functional studies of the human brain and perfusion imaging on a 3 Tesla (T) whole body NMR system. The functional MRI (fMRI) experiments performed showed that single-shot multi-echo EPI and spiral imaging techniques provide fast tools to obtain information about T2* distributions during functional activation in the human brain. Both sequences were found to be useful in the separation of different sources contributing to the functional MR signal like inflow or susceptibility effects in the various vascular environments. An fMRI study dealing with the involvement of prefrontal brain regions in movement preparation lead to inconsistent results. It could not be clarified if these were caused by problems during a spatial normalization process of the individual brains or if the functional paradigm, using very short inter-stimulus intervals, was not suited for the problem investigated. Blood flow velocity measurements in the human finger showed that the use of a strong, small-bore gradient system permits short echo times that reduce flow artefacts and allows high spatial resolution in order to keep systematic errors due to partial volume effects small. With regard to the perfusion investigations an inversion recovery snapshot-FLASH sequence was implemented, which allowed the acquisition of T1 parameter maps of the human brain within a few seconds. The accuracy of this method was demonstrated in test objects. The perfusion investigations with FAIR showed good qualitative results, whereas the quantitative analysis did not yield reproducible findings. A reason for the poor results could be the low signal-to-noise ratio (SNR) of the FAIR images or an incomplete global inversion of the magnetization due to the transmission characteristics of the radio-frequency coil. The BASE sequence that did not require a global inversion yielded quantitative perfusion

  13. Quantitative hepatic CT perfusion measurement: Comparison of Couinaud's hepatic segments with dual-source 128-slice CT

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuan [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Xue, Hua-dan, E-mail: bjdanna95@hotmail.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Jin, Zheng-yu, E-mail: jin_zhengyu@163.com [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China); Su, Bai-yan; Li, Zhuo; Sun, Hao; Chen, Yu; Liu, Wei [The Department of Radiology, Peking Union Medical College Hospital, Dongcheng District, Beijing, 100730 (China)

    2013-02-15

    Purpose: To compare the quantitative liver computed tomography perfusion (CTP) differences among eight hepatic segments. Materials and methods: This retrospective study was based on 72 acquired upper abdomen CTP scans for detecting suspected pancreas tumor. Patients with primary or metastatic liver tumor, any focal liver lesions except simple cyst (<3 cm in diameter), history of liver operation or splenectomy, evidence of liver cirrhosis or invasion of portal vein were excluded. The final analysis included 50 patients (M:F = 21:29, mean age = 43.2 years, 15–76 years). Arterial liver perfusion (ALP), portal-venous perfusion (PVP), total hepatic perfusion (THP = ALP + PVP), and hepatic perfusion index (HPI) of each hepatic segment were calculated and compared by means of one-way analysis of variance (ANOVA) and the Bonferonni correction method. Results: Compared to hepatic segments 5, 6, 7 and 8, segments 2 and 3 showed a tendency of higher ALPs, lower PVPs, and higher HPIs, most of which were statistically significant (p < 0.05). Hepatic segments 1 and 4 had higher mean values of ALP and HPI and lower mean values of PVP than segments 5, 6, 7 and 8 as well, although no significant differences were detected except for ALP and HPI for liver segments 1 and 7 (p = 0.001 and 0.035 respectively), and ALP for liver segments 1 and 5 (p = 0.039). Higher ALP and HPI were showed in hepatic segment 3 compared to segment 4 (p = 0.000 and 0.000 respectively). No significant differences were found for THP among eight segments. Conclusions: Intra-hepatic perfusion differences exist in normal hepatic parenchyma especially between lateral sector (segments 2 and 3) and right lobe (segments 5, 6, 7 and 8). This might have potential clinical significance in liver-perfusion-related protocol design and result analysis.

  14. Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

    Energy Technology Data Exchange (ETDEWEB)

    Dowdle, S.C.; Human, D.G.; Mann, M.D. (Univ. of Cape Town (South Africa))

    1990-08-01

    Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis.

  15. Pulmonary ventilation and perfusion abnormalities and ventilation perfusion imbalance in children with pulmonary atresia or extreme tetralogy of Fallot

    International Nuclear Information System (INIS)

    Dowdle, S.C.; Human, D.G.; Mann, M.D.

    1990-01-01

    Xenon-133 lung ventilation and perfusion scans were done preoperatively after cardiac catheterization and cineangiocardiography in 19 children; 6 had pulmonary atresia with an intact ventricular septum and hypoplastic right ventricle, 4 pulmonary atresia with associated complex univentricular heart, and 9 extreme Tetralogy of Fallot. The four patients with discrepancies in the sizes of the left and right pulmonary arteries on angiography had marked asymmetry of pulmonary perfusion and ventilation-perfusion imbalance on scintigraphy. Similar degrees of asymmetry and imbalance were present in 6 of the 15 children with equal-size pulmonary vessels. Asymmetry of pulmonary perfusion and ventilation-perfusion imbalance were associated with a poor prognosis

  16. Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A. (Dept. of Radiology and Diagnostic Imaging, and Dept. of General and Vascular Surgery, Nicolaus Copernicus Univ., Collegium Medicum, Bydgoszcz (Poland))

    2009-02-15

    Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

  17. Reproducibility of Dynamic Computed Tomography Brain Perfusion Measurements in Patients with Significant Carotid Artery Stenosis

    International Nuclear Information System (INIS)

    Serafin, Z.; Kotarski, M.; Karolkiewicz, M.; Mindykowski, R.; Lasek, W.; Molski, S.; Gajdzinska, M.; Nowak-Nowacka, A.

    2009-01-01

    Background: Perfusion computed tomography (PCT) determination is a minimally invasive and widely available technique for brain blood flow assessment, but its application may be restricted by large variation of results. Purpose: To determine the intraobserver, interobserver, and inter examination variability of brain PCT absolute measurements in patients with significant carotid artery stenosis (CAS), and to evaluate the effect of the use of relative perfusion values on PCT reproducibility. Material and Methods: PCT imaging was completed in 61 patients before endarterectomy, and in 38 of these within 4 weeks after treatment. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP), and peak enhancement intensity (PEI) were calculated with the maximum slope method. Inter examination variability was evaluated based on perfusion of hemisphere contralateral to the treated CAS, from repeated examinations. Interobserver and intraobserver variability were established for the untreated side, based on pretreatment examination. Results: Interobserver and intraobserver variability were highest for CBF measurement (28.8% and 32.5%, respectively), and inter examination variability was the highest for CBV (24.1%). Intraobserver and interobserver variability were higher for absolute perfusion values compared with their respective ratios for CBF and TTP. The only statistically significant difference between perfusion values measured by two observers was for CBF (mean 78.3 vs. 67.5 ml/100 g/min). The inter examination variability of TTP (12.1%) was significantly lower than the variability of other absolute perfusion measures, and the inter examination variability of ratios was significantly lower than absolute values for all the parameters. Conclusion: In longitudinal studies of patients with chronic cerebral ischemia, PCT ratios and either TTP or CBV are more suitable measures than absolute CBF values, because of their considerably lower inter- and intraobserver

  18. New method of isolation and perfusion of rat pancreas for phosphorus nucletic resonance study

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takehisa; Kanno, Tomio; Murakami, Masataka; Watari, Hiroshi; Seo, Yoshiteru

    1988-02-01

    Phosphorus nuclear magnetic resonance (/sup 31/P-NMR) was applied to measure phosphorus metabolites in the pancreas. Rat pancreatic gland was isolated and perfused with a modified Krebs-Henseleit solution at room temperature (25 deg C). Removal of the duodenum from the pancreas made it possible to record /sup 31/P-NMR spectra only from the pancreatic tissue. /sup 31/P signals of creatine phosphate (PCr), ATP and inorganic phosphate (Pi) were observed in all the glands. In different individual glands, the Signal intensity of PCr varied, but those of ATP were almost the same. The initial levels of all the phosphorus metabolites in individual glands remained almost unchanged during perfusion with the standard solution for 2 hours. When the perfusion was stopped, signal intensity of ATP and PCr decreased while Pi resonance increased and shifted to a higher magnetic field, indicating tissue acidification. On re-perfusion, each resonance and tissue pH were restored to the respective initial resting levels. Continuous stimulation with 0.3 ..mu..M acetylcholine (ACh) or 0.1 nM CCK-8 caused a markedly larger increase in pancreatic exocrine secretion than that observed in the perfused pancreas which was prepared by the previous method. Continuous stimulation with 0.1 ..mu..M ACh caused a marked and sustained increase in pancreatic exocrine secretion. During the stimulation, the resonances of phosphorus energy metabolites and tissue pH remained almost unchanged. These results indicate that the isolated perfused rat pancreas which is prepared by our new method is a useful preparation for analysis of secretion-metabolism coupling in the exocrine pancreas.

  19. Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Sowa, Piotr [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Owren Nygaard, Gro [Oslo University Hospital, Department of Neurology, Oslo (Norway); Bjoernerud, Atle [Intervention Center, Oslo University Hospital, Oslo (Norway); University of Oslo, Department of Physics, Oslo (Norway); Gulowsen Celius, Elisabeth [Oslo University Hospital, Department of Neurology, Oslo (Norway); University of Oslo, Institute of Health and Society, Faculty of Medicine, Oslo (Norway); Flinstad Harbo, Hanne [University of Oslo, Institute of Clinical Medicine, Faculty of Medicine, Oslo (Norway); Oslo University Hospital, Department of Neurology, Oslo (Norway); Kristiansen Beyer, Mona [Oslo University Hospital, Department of Radiology and Nuclear Medicine, Oslo (Norway); Oslo and Akershus University College of Applied Sciences, Department of Life Sciences and Health, Oslo (Norway)

    2017-07-15

    The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

  20. Magnetic resonance imaging perfusion is associated with disease severity and activity in multiple sclerosis

    International Nuclear Information System (INIS)

    Sowa, Piotr; Owren Nygaard, Gro; Bjoernerud, Atle; Gulowsen Celius, Elisabeth; Flinstad Harbo, Hanne; Kristiansen Beyer, Mona

    2017-01-01

    The utility of perfusion-weighted imaging in multiple sclerosis (MS) is not well investigated. The purpose of this study was to compare baseline normalized perfusion measures in subgroups of newly diagnosed MS patients. We wanted to test the hypothesis that this method can differentiate between groups defined according to disease severity and disease activity at 1 year follow-up. Baseline magnetic resonance imaging (MRI) including a dynamic susceptibility contrast perfusion sequence was performed on a 1.5-T scanner in 66 patients newly diagnosed with relapsing-remitting MS. From the baseline MRI, cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) maps were generated. Normalized (n) perfusion values were calculated by dividing each perfusion parameter obtained in white matter lesions by the same parameter obtained in normal-appearing white matter. Neurological examination was performed at baseline and at follow-up approximately 1 year later to establish the multiple sclerosis severity score (MSSS) and evidence of disease activity (EDA). Baseline normalized mean transit time (nMTT) was lower in patients with MSSS >3.79 (p = 0.016), in patients with EDA (p = 0.041), and in patients with both MSSS >3.79 and EDA (p = 0.032) at 1-year follow-up. Baseline normalized cerebral blood flow and normalized cerebral blood volume did not differ between these groups. Lower baseline nMTT was associated with higher disease severity and with presence of disease activity 1 year later in newly diagnosed MS patients. Further longitudinal studies are needed to confirm whether baseline-normalized perfusion measures can differentiate between disease severity and disease activity subgroups over time. (orig.)

  1. Higher B-cell activating factor levels at birth are positively associated with maternal dairy farm exposure and negatively related to allergy development.

    Science.gov (United States)

    Lundell, Anna-Carin; Hesselmar, Bill; Nordström, Inger; Adlerberth, Ingegerd; Wold, Agnes E; Rudin, Anna

    2015-10-01

    A high proportion of circulating immature/naive CD5(+) B cells during early infancy is a risk factor for allergy development. B-cell activating factor (BAFF) is an important cytokine for B-cell maturation. We sought to investigate whether BAFF levels are related to environmental exposures during pregnancy and early childhood and whether BAFF levels are associated with postnatal B-cell maturation and allergic disease. In the FARMFLORA study, including both farming and nonfarming families, we measured BAFF levels in plasma from mothers and their children at birth and at 1, 4, 18, and 36 months of age. Infants' blood samples were also analyzed for B-cell numbers and proportions of CD5(+) and CD27(+) B cells. Allergic disease was clinically evaluated at 18 and 36 months of age. Circulating BAFF levels were maximal at birth, and farmers' children had higher BAFF levels than nonfarmers' children. Higher BAFF levels at birth were positively associated with proportions of CD27(+) memory B cells among farmers' children and inversely related to proportions of CD5(+) immature/naive B cells among nonfarmers' children. Children with allergic disease at 18 months of age had lower cord blood BAFF levels than nonallergic children. At birth, girls had higher BAFF levels and lower proportions of CD5(+) B cells than boys. Farm exposure during pregnancy appears to induce BAFF production in the newborn child, and high neonatal BAFF levels were associated with more accelerated postnatal B-cell maturation, which lend further strength to the role of B cells in the hygiene hypothesis. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  2. Pulmonary perfusion scintigraphy in the evaluation of the severity of bronchopulmonary dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Soler, C. [Neonatal Unit, Dept. of Pediatrics, Casa Maternitat Hospital, Clinical Hospital and Sant Joan de Deu Hospital, Univ. of Barcelona (Spain); Figueras, J. [Neonatal Unit, Dept. of Pediatrics, Casa Maternitat Hospital, Clinical Hospital and Sant Joan de Deu Hospital, Univ. of Barcelona (Spain)]|[Servicio de Neonatologia, Hospital Clinico, Barcelona (Spain); Roca, I. [Nuclear Medicine Unit, Autonomous Univ. of Barcelona (Spain); Perez, J.M. [Neonatal Unit, Dept. of Pediatrics, Casa Maternitat Hospital, Clinical Hospital and Sant Joan de Deu Hospital, Univ. of Barcelona (Spain); Jimenez, R. [Neonatal Unit, Dept. of Pediatrics, Casa Maternitat Hospital, Clinical Hospital and Sant Joan de Deu Hospital, Univ. of Barcelona (Spain)

    1997-01-01

    Objective. The objectives of this study were to analyze the changes in pulmonary perfusion in bronchopulmonary dysplasia (BPD) and to assess the advantages of this method in evaluating the severity of BPD. Patients and methods. The study group was made up of 10 children with BPD, matched with a control group of 12 children. The criteria for matching were birth weight, gestational age and need for ventilation for more than 3 days. Clinical and roentgenographic scoring systems were applied on the 21st day of life. At 6 months of corrected age, clinical evolutive severity was evaluated and a pulmonary perfusion scintigraphy using technetium-99 was performed in each child. The scintigraphic findings were classified in five categories ranging from normal to severely affected, depending on the degree and localization of perfusion abnormalities. Another score was obtained by assigning a value from 1 to 5 to each pulmonary lobe, depending on the concentration of the tracer. Results. The study of clinical, roentgenographic and evolutive scores always showed higher values in children with BPD, with good correlation between methods (P < 0.001). In the BPD group, abnormal lung perfusion patterns were more frequent and more severe (P < 0.05), the lobe scoring was higher (P < 0.05), and a lower count rate was found (P < 0.01). Conclusion. Pulmonary scintigraphy is a useful technique in evaluating the severity of BPD. (orig.). With 1 fig., 3 tabs.

  3. Pulmonary perfusion scintigraphy in the evaluation of the severity of bronchopulmonary dysplasia

    International Nuclear Information System (INIS)

    Soler, C.; Figueras, J.; Roca, I.; Perez, J.M.; Jimenez, R.

    1997-01-01

    Objective. The objectives of this study were to analyze the changes in pulmonary perfusion in bronchopulmonary dysplasia (BPD) and to assess the advantages of this method in evaluating the severity of BPD. Patients and methods. The study group was made up of 10 children with BPD, matched with a control group of 12 children. The criteria for matching were birth weight, gestational age and need for ventilation for more than 3 days. Clinical and roentgenographic scoring systems were applied on the 21st day of life. At 6 months of corrected age, clinical evolutive severity was evaluated and a pulmonary perfusion scintigraphy using technetium-99 was performed in each child. The scintigraphic findings were classified in five categories ranging from normal to severely affected, depending on the degree and localization of perfusion abnormalities. Another score was obtained by assigning a value from 1 to 5 to each pulmonary lobe, depending on the concentration of the tracer. Results. The study of clinical, roentgenographic and evolutive scores always showed higher values in children with BPD, with good correlation between methods (P < 0.001). In the BPD group, abnormal lung perfusion patterns were more frequent and more severe (P < 0.05), the lobe scoring was higher (P < 0.05), and a lower count rate was found (P < 0.01). Conclusion. Pulmonary scintigraphy is a useful technique in evaluating the severity of BPD. (orig.). With 1 fig., 3 tabs

  4. Isoattenuating insulinomas at biphasic contrast-enhanced CT: frequency, clinicopathologic features and perfusion characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liang; Xue, Hua-dan; Sun, Hao; Wang, Xuan; He, Yong-lan; Jin, Zheng-yu [Peking Union Medical College Hospital, Department of Radiology, Beijing (China); Zhao, Yu-pei [Peking Union Medical College Hospital, Department of General Surgery, Beijing (China)

    2016-10-15

    We aimed to determine the frequency of isoattenuating insulinomas, to investigate their clinicopathological features and to assess their regional pancreatic perfusion characteristics. Institutional review board approval was obtained, and patient informed consent was waived. From July 2010 to June 2014, 170 patients (66 male, 104 female) with endogenous hyperinsulinemic hypoglycemia underwent biphasic contrast-enhanced CT before surgery, and 129 of those patients also received preoperative whole-pancreas CT perfusion. A total of 181 tumours were proved histopathologically after surgery. Enhancement pattern and regional pancreatic perfusion characteristics were analyzed. Clinical features, tumour size and pathological grading were investigated. The frequency of isoattenuating tumours was 24.9 %. Tumour size and WHO grading was not significantly different between isoattenuating and hyperattenuating tumours. Tumour-free regions had identical blood flow (BF) regardless of their location (p = 0.35). Isoattenuating tumour-harbouring regions had lower BF compared with hyperattenuating tumour-harbouring regions; both showed higher BF compared with tumour-free neighbourhood regions (all p < 0.01). For patients with isoattenuating tumours, the overall hospital stay was longer (p < 0.01). A substantial subset of insulinomas were isoattenuating on biphasic CT. CT perfusion showed higher BF in tumour-harbouring regions compared to tumour-free regions, providing a clue for tumour regionalization. (orig.)

  5. Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

    Energy Technology Data Exchange (ETDEWEB)

    Tutcu, Semra [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Serter, Selim, E-mail: serterselim@gmail.co [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Kaya, Yavuz; Kara, Eray [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey); Nese, Nalan [Department of Pathology, Celal Bayar University, School of Medicine, Manisa (Turkey); Pekindil, Goekhan [Department of Radiology, Celal Bayar University, School of Medicine, Manisa (Turkey); Coskun, Teoman [Department of Surgery, Celal Bayar University, School of Medicine, Manisa (Turkey)

    2010-08-15

    Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

  6. Hepatic perfusion changes in an experimental model of acute pancreatitis: Evaluation by perfusion CT

    International Nuclear Information System (INIS)

    Tutcu, Semra; Serter, Selim; Kaya, Yavuz; Kara, Eray; Nese, Nalan; Pekindil, Goekhan; Coskun, Teoman

    2010-01-01

    Purpose: It is known that acute pancreatitis may cause secondary changes in several organs. Liver is one of these involved organs. In different experimental studies hepatic damages were shown histopathologically in acute pancreatitis but there are a few studies about perfusion disorders that accompany these histopathologic changes. Perfusion CT (pCT) provides the ability to detect regional and global alterations in organ blood flow. The purpose of the study was to describe hepatic perfusion changes in experimental acute pancreatitis model with pCT. Materials and methods: Forty Sprague-Dawley rats of both genders with average weights of 250 g were used. Rats were randomized into two groups. Twenty rats were in control group and 20 in acute pancreatitis group. pCT was performed. Perfusion maps were formed by processing the obtained images with perfusion CT software. Blood flow (BF) and blood volume (BV) values were obtained from these maps. All pancreatic and liver tissues were taken off with laparotomy and histopathologic investigation was performed. Student's t test was used for statistical analyses. Results: In pCT we found statistically significant increase in blood volume in both lobes of liver and in blood flow in right lobe of the liver (p < 0.01). Although blood flow in left lobe of the liver increased, it did not reach statistical significance. Conclusion: The quantitative analysis of liver parenchyma with pCT showed that acute pancreatitis causes a significant perfusion changes in the hepatic tissue. Systemic mediators seem to be effective as well as local inflammatory changes in perfusion changes.

  7. Can preoperative myocardial perfusion scintigraphy predict changes in left ventricular perfusion and function after coronary artery bypass graft surgery?

    DEFF Research Database (Denmark)

    Eckardt, Rozy; Kjeldsen, Bo Juel; Johansen, Allan

    2012-01-01

    OBJECTIVESWe wanted to evaluate whether preoperative myocardial perfusion scintigraphy (MPS) could predict changes in cardiac symptoms and postoperative myocardial perfusion and left ventricular function after coronary artery bypass grafting (CABG).METHODSNinety-two patients with stable angina...... in 26%. Left ventricular ejection fraction (LVEF), which was normal before operation in 45%, improved in 40% of all patients. The increase in LVEF was not related to the preoperative pattern of perfusion defects. Of 30 patients with normalized perfusion after CABG, 29 (97%) had reversible defects...... that reversible or partly reversible perfusion defects at a preoperative MPS have a high chance of normalized myocardial perfusion assessed by MPS 6 months after operation. Normal perfusion is obtained almost exclusively in territories with reversible ischaemia. Symptoms improved in nearly all patients and LVEF...

  8. The clinical application value of myocardial perfusion imaging in evaluating coronary artery myocardial bridge patients with symptoms

    International Nuclear Information System (INIS)

    Wang Yuetao; Fu Ning; Ding Xuemei; Lu Cunzhi; Zhu Feng; Wang Guanmin; Huang Yijie; Wang Linguang

    2008-01-01

    Objective: Myocardial bridge is a common inborn coronary artery anomaly, myocardial bridge may be associated with myocardial ischemia. Only a few patients with coronary artery myocardial bridge were evaluated with nuclear medicine techniques. The aim of this study was to investigate the role of nuclear cardiology with myocardial perfusion technique in symptomatic myocardial bridge patients. Methods Nineteen myocardial bridge patients with the symptoms of chest pain and chest distress were analyzed retrospectively. 99 Tc m -methoxyisobutylisonitrile (MIBI) myocardial perfusion images (both exercise and rest) were performed in all. Imaging results were compared with the results of movement electrocardiogram (ECG) and coronary arteriography. The t test or χ 2 test was used to statistically analyze the data with Stata 7.0 software. Results: Of the 19 patients, 18 patients had myocardial bridge locating at the left anterior descending artery, 1 patient at the left anterior descending and left circumflex artery, the mean angiographic systolic occlusion within the myocardial bridge was (65.4 ± 22.1)%. Of these 19 patients, Exercise-rest 99 Tc m -MIBI myocardial perfusion imaging defined positive myocardial ischemia in 10 and negative in 9 patients. Of the 10 patients with 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia, 8 had reversible radioactive defect of partial anterior wall and (or) apex, 1 had reversible defect of post lateral wall and post septal wall, and 1 had reversible defect of inferior wall. The positive predictive value of myocardial perfusion imaging was 52.6% (10/19), which was higher than movement ECG [21.1% (4/19), χ 2 = 4.07, P 99 Tc m -MIBI myocardial periusion imaging defined myocardial ischemia. Six cases with Grade II stenosis, two were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial ischemia. Eight cases with Grade III stenosis, seven were 99 Tc m -MIBI myocardial perfusion imaging defined myocardial

  9. Optically induced dielectropheresis sorting with automated medium exchange in an integrated optofluidic device resulting in higher cell viability.

    Science.gov (United States)

    Lee, Gwo-Bin; Wu, Huan-Chun; Yang, Po-Fu; Mai, John D

    2014-08-07

    We demonstrated the integration of a microfluidic device with an optically induced dielectrophoresis (ODEP) device such that the critical medium replacement process was performed automatically and the cells could be subsequently manipulated by using digitally projected optical images. ODEP has been demonstrated to generate sufficient forces for manipulating particles/cells by projecting a light pattern onto photoconductive materials which creates virtual electrodes. The production of the ODEP force usually requires a medium that has a suitable electrical conductivity and an appropriate dielectric constant. Therefore, a 0.2 M sucrose solution is commonly used. However, this requires a complicated medium replacement process before one is able to manipulate cells. Furthermore, the 0.2 M sucrose solution is not suitable for the long-term viability of cells. In comparison to conventional manual processes, our automated medium replacement process only took 25 minutes. Experimental data showed that there was up to a 96.2% recovery rate for the manipulated cells. More importantly, the survival rate of the cells was greatly enhanced due to this faster automated process. This newly developed microfluidic chip provided a promising platform for the rapid replacement of the cell medium and this was also the first time that an ODEP device was integrated with other active flow control components in a microfluidic device. By improving cell viability after cell manipulation, this design may contribute to the practical integration of ODEP modules into other lab-on-a-chip devices and biomedical applications in the future.

  10. Evaluation of brain perfusion in Alzheimer disease with perfusion computed tomography and comparison to elderly patient without dementia.

    Science.gov (United States)

    Yildirim, Tülin; Karakurum Göksel, Başak; Demir, Şenay; Tokmak, Naime; Tan, Meliha

    2016-04-19

    The aim of this study was to evaluate perfusion computed tomography (PCT) findings in patients with Alzheimer disease and to compare them with those of patients without dementia. PCT was performed in 35 patients: 20 with Alzheimer disease (mean age, 69.7 ± 5.5 years) and 15 control subjects (mean age, 67.5 ± 3.5 years). Control subjects were elderly individuals with no cognitive problems who were admitted with headaches. All PCT examinations were performed on a 4-slice CT unit. The PCT analysis software program was used to calculate regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), regional time-to-peak (rTTP) values in the bilateral frontal, temporal, and occipital cortices, and bilateral lentiform nucleus. rCBF values in the bilateral frontal and temporal cortices and bilateral lentiform nucleus were significantly lower in the patients with Alzheimer disease than in the control subjects. There were no significant differences in rCBV values between Alzheimer disease and the control group. rTTP values in all cortical areas and bilateral lentiform nucleus were significantly higher in the patients with Alzheimer disease than in the control subjects. PCT is a rapid and reliable imaging modality for evaluating brain perfusion in Alzheimer disease.

  11. Computer modeling of the combined effects of perfusion, electrical conductivity, and thermal conductivity on tissue heating patterns in radiofrequency tumor ablation.

    Science.gov (United States)

    Ahmed, Muneeb; Liu, Zhengjun; Humphries, Stanley; Goldberg, S Nahum

    2008-11-01

    could not be achieved at higher inner/outer perfusions (>4 kg/m(3)-s). For varied electrical conductivities in the setting of varied perfusion, greatest RF heating occurred for inner electrical conductivities simulating injection of saline around the electrode with an outer electrical conductivity of soft tissue, and the least amount of heating occurring while simulating renal cell carcinoma in normal kidney. Characterization of these scenarios demonstrated the role of electrical and thermal conductivity interactions, with the greatest differences in effect seen in the 3-4 cm tumor range, as almost all 2 cm tumors and almost no 5 cm tumors could be treated. Optimal combinations of thermal and electrical conductivity can partially negate the effect of perfusion. For clinically relevant tumor sizes, thermal and electrical conductivity impact which tumors can be successfully ablated even in the setting of almost non-existent perfusion.

  12. Mechanism of radiation tolerance in higher plants. Radiation damage of DNA in cultured tobacco BY-2 cells and implication from its repair process

    International Nuclear Information System (INIS)

    Yokota, Yuichiro; Narumi, Issay; Funayama, Tomoo; Kobayashi, Yasuhiko; Tanaka, Jun; Inoue, Masayoshi

    2007-01-01

    This paper describes the mechanism of radiation tolerance at the cellular level in higher plants, of which fundamental study basis is rather poor, in cultured cells in the title (BY-2 cells, Nicotiana tabacum L., allotetraploid). When compared with LD 50 of radiation in higher animals (2.4-8.6 Gy), higher plants are generally tolerant to radiation (known LD 50 , >360-2000 Gy). Authors have made unicellular BY-2 cells (protoplasts) by enzyme treatment to see their colony forming ability (CFA) and have found those cells are also resistant to radiation: D 10 (10% CFA dose) (Gy) is found to be 8.2-47.2 by radiation with various linear energy transfer (LET)s like gamma ray and heavy ion beams, in contrast to human D 10 (1.17-8.12, by X-ray and carbon beam). Double strand break (DSB) of DNA by radiation per one BY-2 cell initially occurs 7-10 times more frequently than mammalian cells (CHO-K1). However, DSB repair in BY-2 cells is found only as efficient as in mammalian cells: a slow repair relative to DSB number. Checkpoint mechanism of DNA damage is found poorly working in BY-cells, which results in frequent chromosome aberration like micronucleus. Authors consider that, for an herbaceous plant, to precede the cell cycle rather than to recover from the genomic instability can be profitable for growing more rapidly to have more sunlight energy than other individuals. Improvement of plants by gene technological approach with such a mean as mutation by radiation is conceivably important from aspects of food supply and of ecological environment. (R.T.)

  13. Dysembryoplastic neuroepithelial tumors: proton MR spectroscopy, diffusion and perfusion characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Bulakbasi, Nail; Kocaoglu, Murat; Sanal, Tuba H.; Tayfun, Cem [Gulhane Military Medical Academy, Department of Radiology, Military Medical Faculty, Ankara (Turkey)

    2007-10-15

    We describe the magnetic resonance (MR) imaging characteristics of dysembryoplastic neuroepithelial tumors (DNT) and discuss their differential diagnosis. Proton MR spectroscopy (TE 30 and 136 ms), diffusion-weighted and perfusion images were retrospectively evaluated in 22 patients with pathologically proven DNT (17 male and 5 female, mean age 18.7 years) and 14 control subjects (10 male and 4 female, mean age 16.9 years). The results from the DNT patients and from the control subjects were compared using an independent sample t-test and the degree of correlation was tested by Pearson's correlation. All DNTs were solitary and in a supratentorial cortical or subcortical location (ten temporal, eight frontal and four parietal). They had low-signal on T1-weighted images and high-signal on T2-weighted images without a prominent mass effect. Additionally a cystic appearance (six patients, 27.3%), cortical dysplasia (six patients, 27.3%) and contrast enhancement (four patients, 18.2%) were also noted. No significant differences were detected in NAA/Cho, NAA/Cr, NAA/Cho+Cr or Cho/Cr ratios between DNT and normal brain. DNTs had a significantly higher mI/Cr ratio and apparent diffusion coefficient (ADC) values and lower cerebral blood values than normal parenchyma (P < 0.001). ADC had the highest correlation with the diagnosis of DNT (r = 0.996) followed by relative cerebral blood volume (rCBV) (r = -0.883) and mI/Cr ratio (r = 0.663). Proton MR spectroscopy, diffusion-weighted and perfusion imaging characteristics of DNTs provide additional information to their MR imaging findings. The MR spectrum showing a slight increase in mI/Cr ratio, and higher ADC and lower rCBV values than normal parenchyma help to differentiate DNTs from other cortical tumors, which had higher rCBV and lower ADC values than DNTs. (orig.)

  14. Quantitative aspects of myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Vogel, R.A.

    1980-01-01

    Myocardial perfusion measurements have traditionally been performed in a quantitative fashion using application of the Sapirstein, Fick, Kety-Schmidt, or compartmental analysis principles. Although global myocardial blood flow measurements have not proven clinically useful, regional determinations have substantially advanced our understanding of and ability to detect myocardial ischemia. With the introduction of thallium-201, such studies have become widely available, although these have generally undergone qualitative evaluation. Using computer-digitized data, several methods for the quantification of myocardial perfusion images have been introduced. These include orthogonal and polar coordinate systems and anatomically oriented region of interest segmentation. Statistical ranges of normal and time-activity analyses have been applied to these data, resulting in objective and reproducible means of data evaluation

  15. Nursing implications for Hepatic arterial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Ellender, R.

    1999-01-01

    Nurses working in Nuclear Medicine assist in Hepatic Artery Catheter (HAC) perfusion studies. This scan is not widely performed in Australia, the St George hospital for example performs approximately five per year. The purpose of this article is firstly to review the indications and rationale of HAC patency studies. Secondly, this article will stress the clinical implications for the Nuclear Medicine Nurse during this study. Emphasis will be placed on the importance of patient education during the procedure. A brief overview of hepatic anatomy and the radiopharmaceuticals administered during the scan is discussed. Finally, a step by step protocol is presented to show how the perfusion/ shunt study is performed. Copyright (1999) The Australian and New Zealand Society of Nuclear Medicine Inc

  16. Perfusion lung scintigraphy in primary pulmonary hypertension

    International Nuclear Information System (INIS)

    Ogawa, Yoji; Nishimura, Tsunehiko; Kumita, Shin-ichirou; Hayashida, Kohei; Uehara, Toshiisa; Shimonagata, Tsuyoshi; Ohno, Akira

    1991-01-01

    Fifteen cases with primary pulmonary hypertension (PPH) were classified into two groups by using the perfusion lung scan pattern. Eight cases had multiple, small, ill-defined defects (mottled pattern), and remaining seven cases had no mottled pattern. These two groups were compared with mean pulmonary arterial pressure (mean PAP), right ventricular ejection fraction (RVEF), blood gas at room air (PaO 2 ), and alveolar-arterial O 2 difference (A-aDo 2 ). The cases with mottled pattern showed a significant increase in mean PAP. There were no significant differences in RVEF, PaO 2 , and A-aDo 2 , between the groups. The survival rate of the patients with mottled pattern was significantly lower than that without mottled pattern (p<0.05). We concluded that perfusion lung scan is very useful for evaluation of the prognosis in primary pulmonary hypertension. (author)

  17. Cerebral perfution studies; Estudios de Perfusion Cerebral

    Energy Technology Data Exchange (ETDEWEB)

    Mut, Fernando [Universidad de la Republica, Montevideo (Uruguay). Centro de Medicina Nuclear

    1994-12-31

    For detecting in precocious form a coronary disease is necessary to aply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images, proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases.

  18. Regional cerebral perfusion in cardiovascular reflex syncope

    International Nuclear Information System (INIS)

    Toeyry, J.P.; Kuikka, J.T.; Laensimies, E.A.

    1997-01-01

    Little is known about the regional cerebral perfusion in subjects with presyncope or syncope, and the impact that autonomic nervous dysfunction has on it. Seven subjects with cardiovascular vasodepressor reflex syncope were studied. A baseline test was performed with the patients standing in the 70 upright position, while the passive head-up tilt table test with and without isoprenaline infusion was employed for provocation. Regional cerebral perfusion was assessed by means of single-photon emission tomography with technetium-99m labelled V-oxo-1,2-N,N 1 -ethylenedylbis-l-cysteine diethylester (baseline, and during blood pressure decline in the provocation test) and the autonomic nervous function by means of spectral analysis of heart rate variability (baseline, and before blood pressure decline in the provocation test). Every subject showed an abrupt decline in blood pressure in the provocation test (five with presyncope and two with syncope). The systolic and diastolic blood pressures decreased significantly (P<0.001) between the baseline and the provocation study time points (radiopharmaceutical injection and lowest systolic blood pressure). Mean cerebral perfusion as average count densities decreased upon provocation as compared with baseline (190±63 vs 307±90 counts/voxel, respectively, P=0.013). Hypoperfusion was most pronounced in the frontal lobe. These results suggest that cerebral perfusion decreases markedly during presyncope or syncope with systemic blood pressure decline in subjects with cardiovascular vasodepressor syncope. Furthermore, the autonomic nervous function remains unchanged before the systemic blood pressure decline. (orig.). With 3 figs., 2 tabs

  19. Myocardial perfusion studies in coronary diseases

    International Nuclear Information System (INIS)

    Mut, Fernando

    1994-01-01

    For detecting in precocious form a coronary disease is necessary to apply a diagnostic techniques. The main considerations to be indicated in the present work are: physiological considerations, myocardial perfusion studies with radiotracers such as Talio 201, 99mTc, MIBI, 99mTc-Teboroxima, 99mTc-Fosfinas, instrumentation for obtain good images,proceedings protocols, studies interpretation, standards, SPECT, anomalies standards, coronary diseases

  20. Characteristic findings of exercise ECG test, perfusion SPECT and coronary angiography in patients with exercise induced myocardial stunning

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Byeong Cheol; Seo, Ji Hyoung; Bae, Jin Ho; Jeong, Shin Young; Park, Hun Sik; Lee, Jae Tae; Chae, Shung Chull; Lee, Kyu Bo [School of Medicine, Kyungpook National Univ., Daegu (Korea, Republic of)

    2004-06-01

    Transient wall motion abnormality and contractile dysfunction of the left ventricle (LV) can be observed in patients with coronary artery disease due to post-stress myocardial stunning. To understand clinical characteristics of stress induced LV dysfunction, we have compared the findings of exercise stress test, myocardial perfusion SPECT and coronary angiography between subjects with and without post-stress LV dysfunction. Among subjects who underwent exercise stress test, myocardial perfusion SPECT and coronary angiography within a month of interval, we enrolled 36 patients with post-stress LV ejection fraction (LVEF) was {>=}5% lower than rest (stunning group) and 16 patients with difference of post-stress and rest LVEF was lesser than 1% (non-stunning group) for this study. Treadmill exercise stress gated myocardial perfusion SPECT was performed with dual head SPECT camera using 740 MBq Tc-99m MIBI and coronary angiography was also performed by conventional Judkins method. Stunning group had a significantly higher incidence of hypercholesterolemia than non-stunning group(45.5 vs 7.1%, p=0.01). Stunning group also had higher incidence of diabetes mellitus and lower incidence of hypertension, but these were not statistically significant. Stunning group had larger and more severe perfusion defect in stress perfusion myocardial SPECT than non-stunning group(extent 18.2 vs 9.2%, p=0.029; severity 13.5 vs 6.9, p=0.040). Stunning group also had higher degree of reversibility of perfusion defect, higher incidence of positive exercise stress test and higher incidence of having severe stenosis(80{approx}99%) in coronary angiography than non-stunning group, but these were not statistically significant. In stunning group, all of 4 patients without perfusion defect had significant coronary artery stenosis and had received revascularization treatment. Patients with post-stress LV dysfunction had larger and more severe perfusion defect and severe coronary artery stenosis than

  1. Non-contrast MRI perfusion angiosome in diabetic feet

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Cardiovascular Imaging Lab, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Hastings, Mary K.; Mueller, Michael J. [Washington University School of Medicine, The Program in Physical Therapy, St. Louis, MO (United States); Muccigross, David; Hildebolt, Charles F. [Washington University School of Medicine, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Fan, Zhaoyang [Cedars-Sinai Medical Center, Biomedical Imaging Research Institute, Los Angeles, CA (United States); Gao, Fabao [West China Hospital, Sichuan University, Department of Radiology, Chengdu (China); Curci, John [Washington University School of Medicine, The Department of Surgery, St. Louis, MO (United States)

    2015-01-15

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  2. Non-contrast MRI perfusion angiosome in diabetic feet

    International Nuclear Information System (INIS)

    Zheng, Jie; Hastings, Mary K.; Mueller, Michael J.; Muccigross, David; Hildebolt, Charles F.; Fan, Zhaoyang; Gao, Fabao; Curci, John

    2015-01-01

    The purpose of this study is to develop a non-contrast magnetic resonance imaging (MRI) approach to evaluate skeletal muscle perfusion in the diabetic foot based on the concept of angiosomes of the foot. Five healthy volunteers and five participants with diabetes (HbA1c = 7.2 ± 1.8 %) without a history of peripheral artery disease were examined. The non-contrast perfusion measurements were performed during a toe flexion challenge. Absolute perfusion maps were created and two regions (medial and lateral) on the maps were segmented based on angiosomes. Regional difference in the perfusion of foot muscle was readily visualized in the MRI perfusion angiosomes during the challenge. In the participants with diabetes, the perfusion during toe flexion challenge was significantly lower than in healthy volunteers (P < 0.01). The average perfusion for the medial plantar region of the right foot was lower in subjects with diabetes (38 ± 9 ml/min/100 g) than in healthy subjects (93 ± 33 ml/min/100 g). Non-contrast MRI perfusion angiosome maps demonstrate the feasibility of determining regional perfusion in foot muscles during toe challenge and may facilitate evaluation of muscle perfusion in diabetic feet. (orig.)

  3. Can perfusion SPECT aid CTPA interpretation?

    International Nuclear Information System (INIS)

    Gradinscak, D. J.; Roach, P.; Bailey, E.; Kueh, S.

    2009-01-01

    Full text:Objective: To determine whether fusion of perfusion SPECT and CTPA improves the diagnostic accuracy of CTPA. Methods: 35 patients with suspected PE who underwent both CTPA and SPECT V/Q within 48 hours were included. Of these, the majority (n=30) had PE as determined by the V/Q SPECT scan and the others (n=5) were negative for PE. The clinical reports of CTPA were reviewed and pulmonary emboli tabulated based on anatomical location. A second radiologist, blinded to the results of the clinical read and the V/Q SPECT scan, reviewed the CTPA with and without perfusion SPECT fusion for assistance. Results: A total 57 PE were reported on the clinical reports and 60 PE identified on the blinded read. Fused CTPA/perfursion SPECT images identified a further 5 PE not identified on the clinical read (8% increase) and 2 PE not identified on the blinded read (3% increase). The additional emboli detected resulted in a change in final diagnosis from PE negative to PE positive in 2 patients (6%) compared with the clinical read and 1 patient (3%) compared with the blinded read without SPECT fusion. Conclusion: Fused CTPA-SPECT perfusion improves the sensitivity of CTPA for the detection of PE in a small number of patients. Fused data may help guide the radiologist to identify sites of PE on CTPA.

  4. Cerebral perfusion in homogeneity in normal volunteers

    International Nuclear Information System (INIS)

    Gruenwald, S.M.; Larcos, G.

    1998-01-01

    Full text: In the interpretation of cerebral perfusion scans, it is important to know the normal variation in perfusion which may occur between the cerebral hemispheres. For this reason 24 normal volunteers with no neurological or psychiatric history, and who were on no medications, had 99m Tc-HMPAO brain SPECT studies using a single headed gamma camera computer system. Oblique, coronal and sagittal images were reviewed separately by two experienced observers and any differences were resolved by consensus. Semi-quantitation was performed by summing two adjacent oblique slices and drawing right and left mirror image ROIs corresponding to the mid section level of anterior and posterior frontal lobes, anterior and posterior parietal lobes, temporal lobes and cerebellum. From the mean counts per pixel, right: left ROI ratios and ROI: cerebellar ratios were calculated. On qualitative review 6/24 subjects had mild asymmetry in tracer distribution between right and left cerebral lobes. Semi-quantitation revealed a 5-10% difference in counts between right and left ROIs in 12/24 subjects and an additional three subjects had 10-20% difference in counts between right and left temporal lobes. This study demonstrates the presence of mild asymmetry of cerebral perfusion in a significant minority of normal subjects

  5. Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

    International Nuclear Information System (INIS)

    Schumann, Stefan; Schließmann, Stephan J; Wagner, Giskard; Goebel, Ulrich; Priebe, Hans-Joachim; Guttmann, Josef; Kirschbaum, Andreas

    2010-01-01

    Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH 2 O) or high (8 cmH 2 O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

  6. Correlation of iodine uptake and perfusion parameters between dual-energy CT imaging and first-pass dual-input perfusion CT in lung cancer.

    Science.gov (United States)

    Chen, Xiaoliang; Xu, Yanyan; Duan, Jianghui; Li, Chuandong; Sun, Hongliang; Wang, Wu

    2017-07-01

    To investigate the potential relationship between perfusion parameters from first-pass dual-input perfusion computed tomography (DI-PCT) and iodine uptake levels estimated from dual-energy CT (DE-CT).The pre-experimental part of this study included a dynamic DE-CT protocol in 15 patients to evaluate peak arterial enhancement of lung cancer based on time-attenuation curves, and the scan time of DE-CT was determined. In the prospective part of the study, 28 lung cancer patients underwent whole-volume perfusion CT and single-source DE-CT using 320-row CT. Pulmonary flow (PF, mL/min/100 mL), aortic flow (AF, mL/min/100 mL), and a perfusion index (PI = PF/[PF + AF]) were automatically generated by in-house commercial software using the dual-input maximum slope method for DI-PCT. For the dual-energy CT data, iodine uptake was estimated by the difference (λ) and the slope (λHU). λ was defined as the difference of CT values between 40 and 70 KeV monochromatic images in lung lesions. λHU was calculated by the following equation: λHU = |λ/(70 - 40)|. The DI-PCT and DE-CT parameters were analyzed by Pearson/Spearman correlation analysis, respectively.All subjects were pathologically proved as lung cancer patients (including 16 squamous cell carcinoma, 8 adenocarcinoma, and 4 small cell lung cancer) by surgery or CT-guided biopsy. Interobserver reproducibility in DI-PCT (PF, AF, PI) and DE-CT (λ, λHU) were relatively good to excellent (intraclass correlation coefficient [ICC]Inter = 0.8726-0.9255, ICCInter = 0.8179-0.8842; ICCInter = 0.8881-0.9177, ICCInter = 0.9820-0.9970, ICCInter = 0.9780-0.9971, respectively). Correlation coefficient between λ and AF, and PF were as follows: 0.589 (P input CT perfusion analysis method can be applied to assess blood supply of lung cancer patients. Preliminary results demonstrated that the iodine uptake relevant parameters derived from DE-CT significantly correlated with perfusion

  7. Release of galanin from isolated perfused porcine adrenal glands

    DEFF Research Database (Denmark)

    Holst, J J; Ehrhart-Bornstein, M; Messell, T

    1991-01-01

    We found a high concentration of galanin in extracts of porcine adrenal glands (114 pmol/g). By immunohistochemistry, galanin was localized to groups of medullary cells previously shown to produce norepinephrine. To study mechanisms for the release of galanin, we developed the following in vitro...... model: isolated perfused porcine adrenals with intact splanchnic nerve supply. When the nerves were electrically stimulated, epinephrine and norepinephrine secretion increased 276- and 291-fold, respectively, and galanin release increased up to 1,300-fold. Acetylcholine at 10(-6) M stimulated galanin...... release, and hexamethonium almost abolished the response to nerve stimulation. Galanin infusions had no effect on epinephrine and norepinephrine secretion in concentrations of 10(-8) and 10(-7) M, but increased both cortisol and aldosterone secretion (P less than 0.05). Splanchnic nerve stimulation...

  8. Towards robust deconvolution of low-dose perfusion CT: Sparse perfusion deconvolution using online dictionary learning

    Science.gov (United States)

    Fang, Ruogu; Chen, Tsuhan; Sanelli, Pina C.

    2014-01-01

    Computed tomography perfusion (CTP) is an important functional imaging modality in the evaluation of cerebrovascular diseases, particularly in acute stroke and vasospasm. However, the post-processed parametric maps of blood flow tend to be noisy, especially in low-dose CTP, due to the noisy contrast enhancement profile and the oscillatory nature of the results generated by the current computational methods. In this paper, we propose a robust sparse perfusion deconvolution method (SPD) to estimate cerebral blood flow in CTP performed at low radiation dose. We first build a dictionary from high-dose perfusion maps using online dictionary learning and then perform deconvolution-based hemodynamic parameters estimation on the low-dose CTP data. Our method is validated on clinical data of patients with normal and pathological CBF maps. The results show that we achieve superior performance than existing methods, and potentially improve the differentiation between normal and ischemic tissue in the brain. PMID:23542422

  9. Pulmonary artery perfusion versus no perfusion during cardiopulmonary bypass for open heart surgery in adults

    DEFF Research Database (Denmark)

    Buggeskov, Katrine B; Grønlykke, Lars; Risom, Emilie C

    2018-01-01

    BACKGROUND: Available evidence has been inconclusive on whether pulmonary artery perfusion during cardiopulmonary bypass (CPB) is associated with decreased or increased mortality, pulmonary events, and serious adverse events (SAEs) after open heart surgery. To our knowledge, no previous systematic...... handsearched retrieved study reports and scanned citations of included studies and relevant reviews to ensure that no relevant trials were missed. We searched for ongoing trials and unpublished trials in the World Health Organization International Clinical Trials Registry Platform (ICTRP) and at clinicaltrials......). We used GRADE principles to assess the quality of evidence. MAIN RESULTS: We included in this review four RCTs (210 participants) reporting relevant outcomes. Investigators randomly assigned participants to pulmonary artery perfusion with blood versus no perfusion during CPB. Only one trial included...

  10. Ex vivo perfusion of human spleens maintains clearing and processing functions.

    Science.gov (United States)

    Buffet, Pierre A; Milon, Geneviève; Brousse, Valentine; Correas, Jean-Michel; Dousset, Bertrand; Couvelard, Anne; Kianmanesh, Reza; Farges, Olivier; Sauvanet, Alain; Paye, François; Ungeheuer, Marie-Noëlle; Ottone, Catherine; Khun, Huot; Fiette, Laurence; Guigon, Ghislaine; Huerre, Michel; Mercereau-Puijalon, Odile; David, Peter H

    2006-05-01

    The spleen plays a central role in the pathophysiology of several potentially severe diseases such as inherited red cell membrane disorders, hemolytic anemias, and malaria. Research on these diseases is hampered by ethical constraints that limit human spleen tissue explorations. We identified a surgical situation--left splenopancreatectomy for benign pancreas tumors--allowing spleen retrieval at no risk for patients. Ex vivo perfusion of retrieved intact spleens for 4 to 6 hours maintained a preserved parenchymal structure, vascular flow, and metabolic activity. Function preservation was assessed by testing the ability of isolated-perfused spleens to retain Plasmodium falciparum-infected erythrocytes preexposed to the antimalarial drug artesunate (Art-iRBCs). More than 95% of Art-iRBCs were cleared from the perfusate in 2 hours. At each transit through isolated-perfused spleens, parasite remnants were removed from 0.2% to 0.23% of Art-iRBCs, a proportion consistent with the 0.02% to 1% pitting rate previously established in artesunate-treated patients. Histologic analysis showed that more than 90% of Art-iRBCs were retained and processed in the red pulp, providing the first direct evidence of a zone-dependent parasite clearance by the human spleen. Human-specific physiologic or pathophysiologic mechanisms involving clearing or processing functions of the spleen can now be experimentally explored in a human tissue context.

  11. Industrialization of a perfusion bioreactor: Prime example of a non-straightforward process.

    Science.gov (United States)

    Talò, G; Turrisi, C; Arrigoni, C; Recordati, C; Gerges, I; Tamplenizza, M; Cappelluti, A; Riboldi, S A; Moretti, M

    2018-02-01

    Bioreactors are essential enabling technologies for the translation of advanced therapies medicinal products from the research field towards a successful clinical application. In order to speed up the translation and the spread of novel tissue engineering products into the clinical routine, tissue engineering bioreactors should evolve from laboratory prototypes towards industrialized products. In this work, we thus challenged the industrialization process of a novel technological platform, based on an established research prototype of perfusion bioreactor, following a GMP-driven approach. We describe how the combination of scientific background, intellectual property, start-up factory environment, wise industrial advice in the biomedical field, design, and regulatory consultancy allowed us to turn a previously validated prototype technology into an industrial product suitable for serial production with improved replicability and user-friendliness. The solutions implemented enhanced aesthetics, ergonomics, handling, and safety of the bioreactor, and they allowed compliance with the fundamental requirements in terms of traceability, reproducibility, efficiency, and safety of the manufacturing process of advanced therapies medicinal products. The result is an automated incubator-compatible device, housing 12 disposable independent perfusion chambers for seeding and culture of any perfusable tissue. We validated the cell seeding process of the industrialized bioreactor by means of the Design of Experiment approach, whilst the effectiveness of perfusion culture was evaluated in the context of bone tissue engineering. Copyright © 2017 John Wiley & Sons, Ltd.

  12. The Myocardial Perfusion Scintigraphy in Predicting Risk for Coronary Artery Disease in Patients with Anxiety and Depression Symptoms

    Directory of Open Access Journals (Sweden)

    Billur Çalışkan

    2016-06-01

    Full Text Available INTRODUCTION: An association between psychological factors and cardiovascular disease, has long been suspected. However it is not clear whether chest pain is caused by emotional distress or whether coronary spasms are caused by the onset of coronary artery disease (CAD. We aimed to predict the risk for CAD in patients referred to myocardial perfusion imaging (MPI with chest pain using depression, stress, and anxiety symptoms. METHODS: The emotional status of all patients was evaluated using the Hospital Anxiety and Depression Scale (HADS-A and HADS-D, the State and Trait Anxiety Inventory (STAI-1 and STAI-2, the Perceived Stress Scale (PSS, and the Anxiety Sensitivity Index-3 (ASI. Myocardial perfusion was measured using a 17-segment model and 5-point scoring system (0: normal perfusion; 4: no perfusion. RESULTS: MPI revealed reversible perfusion defects in 24 of 141 patients and no perfusion defects in 117 patients. The STAI-2 and HADS-A and HADS-D scores were significantly higher in patients with myocardial ischemia than in those without (STAI-2: 50.8 ± 7.5 vs. 46.3 ± 7.1, respectively; p = 0.008; HADS-A: 9.5 ± 3.9 vs. 7.8 ± 3.4, respectively; p = 0.033; HADS-D: 8.7 ± 3.0 vs. 7.3 ± 3.0, respectively; p = 0.05. Unadjusted correlation analysis showed that there was statistically significant correlation between reversible perfusion defects and anxiety scores (r=0.186, p= 0.029. DISCUSSION AND CONCLUSION: The patients with symptoms of depression and high-trait anxiety may be at higher risk of myocardial ischemia than patients without such symptoms. Thus, the emotional status of patients should be taken into consideration during clinical evaluation for CAD.

  13. Recent developments in gamma camera technology for myocardial perfusion scintigraphy

    International Nuclear Information System (INIS)

    Bengel, Frank M.

    2010-01-01

    Economic pressure, competition from alternative modalities and an increasing awareness of patient radiation exposure have triggered a rapid development of novel technology for cardiac single-photon emission computed tomography (SPECT) in recent years. The trend clearly goes towards systems with higher sensitivity and resolution, and towards faster acquisition protocols. Those goals are achieved by various measures: On the one hand, several manufacturers have integrated novel semiconductor detector materials together with innovative collimators into dedicated cardiac scanners. On the other hand, new collimators and reconstruction algorithms have lead to increased speed and accuracy of conventional gamma cameras. Imaging times now can be reduced to as much as 10% of that of previous standard protocols, and/or injected activity can be reduced. This is achieved without loss of diagnostic accuracy. These novel developments are still in early phases of clinical implementation. Their potential for a profound change of the clinical practice of myocardial perfusion scintigraphy, however, becomes increasingly obvious. (orig.)

  14. Developing a Benchmarking Process in Perfusion: A Report of the Perfusion Downunder Collaboration

    Science.gov (United States)

    Baker, Robert A.; Newland, Richard F.; Fenton, Carmel; McDonald, Michael; Willcox, Timothy W.; Merry, Alan F.

    2012-01-01

    Abstract: Improving and understanding clinical practice is an appropriate goal for the perfusion community. The Perfusion Downunder Collaboration has established a multi-center perfusion focused database aimed at achieving these goals through the development of quantitative quality indicators for clinical improvement through benchmarking. Data were collected using the Perfusion Downunder Collaboration database from procedures performed in eight Australian and New Zealand cardiac centers between March 2007 and February 2011. At the Perfusion Downunder Meeting in 2010, it was agreed by consensus, to report quality indicators (QI) for glucose level, arterial outlet temperature, and pCO2 management during cardiopulmonary bypass. The values chosen for each QI were: blood glucose ≥4 mmol/L and ≤10 mmol/L; arterial outlet temperature ≤37°C; and arterial blood gas pCO2 ≥ 35 and ≤45 mmHg. The QI data were used to derive benchmarks using the Achievable Benchmark of Care (ABC™) methodology to identify the incidence of QIs at the best performing centers. Five thousand four hundred and sixty-five procedures were evaluated to derive QI and benchmark data. The incidence of the blood glucose QI ranged from 37–96% of procedures, with a benchmark value of 90%. The arterial outlet temperature QI occurred in 16–98% of procedures with the benchmark of 94%; while the arterial pCO2 QI occurred in 21–91%, with the benchmark value of 80%. We have derived QIs and benchmark calculations for the management of several key aspects of cardiopulmonary bypass to provide a platform for improving the quality of perfusion practice. PMID:22730861

  15. Comparison of the Peripheral Reactive Hyperemia Index with Myocardial Perfusion Reserve byRb PET/CT in HIV-Infected Patients

    DEFF Research Database (Denmark)

    Ørbæk, Mathilde; Hasbak, Philip; Sejersten Ripa, Rasmus

    2017-01-01

    (CAD) seems to be higher in HIV-infected patients and an accurate risk prediction of CAD is of high importance for optimal long term treatment. In this study, we assessed the correlation of the endoPAT, which is an office-based CVD screening tool with the myocardial perfusion reserve by82-rubidium PET...... undergone measurement of the myocardial perfusion reserve by82-rubidium PET/CT for study purposes. We found an inverse correlation between the reactive hyperemia index and the myocardial perfusion reserve which most likely indicates different vascular physiology. This study did not find evidence to suggest...

  16. Magnetic Resonance Imaging of Ventilation and Perfusion in the Lung

    Science.gov (United States)

    Prisk, Gordon Kim (Inventor); Hopkins, Susan Roberta (Inventor); Buxton, Richard Bruce (Inventor); Pereira De Sa, Rui Carlos (Inventor); Theilmann, Rebecca Jean (Inventor); Cronin, Matthew Vincent (Inventor)

    2017-01-01

    Methods, devices, and systems are disclosed for implementing a fully quantitative non-injectable contrast proton MRI technique to measure spatial ventilation-perfusion (VA/Q) matching and spatial distribution of ventilation and perfusion. In one aspect, a method using MRI to characterize ventilation and perfusion in a lung includes acquiring an MR image of the lung having MR data in a voxel and obtaining a breathing frequency parameter, determining a water density value, a specific ventilation value, and a perfusion value in at least one voxel of the MR image based on the MR data and using the water density value to determine an air content value, and determining a ventilation-perfusion ratio value that is the product of the specific ventilation value, the air content value, the inverse of the perfusion value, and the breathing frequency.

  17. Myocardial perfusion in type 2 diabetes with left ventricular hypertrophy

    DEFF Research Database (Denmark)

    Hesse, Birger; Meyer, Christian; Nielsen, Flemming S

    2004-01-01

    The purpose of this study was to assess whether acute angiotensin-converting enzyme (ACE) inhibition would improve myocardial perfusion and perfusion reserve in a subpopulation of normotensive patients with diabetes and left ventricular hypertrophy (LVH), both independent risk factors of coronary...... disease. Using positron emission tomography (PET), we investigated the response of regional myocardial perfusion to acute ACE inhibition with i.v. infusion of perindoprilat (vs saline infusion as control, minimum interval 3 days) in 12 diabetic patients with LVH. Myocardial perfusion was quantified...... with controls, maximal perfusion was reduced in patients (1.8+/-0.6 vs 2.5+/-1.0 ml min(-1) g(-1); P2.7+/-1.0 vs 3.6+/-1.3; P=0.059). During perindoprilat infusion, myocardial perfusion reserve in patients increased to 3.9+/-0.9 ( P

  18. Reversible ventilation and perfusion abnormalities in unilateral obstructed lung

    International Nuclear Information System (INIS)

    Ward, H.E.; Jones, R.L.; King, E.G.; Sproule, B.J.; Fortune, R.L.

    1982-01-01

    An intraluminal carcinoid tumor obstructing the left mainstem bronchus produced hypoxemia through alteration in ventilation/perfusion matching. Studies of regional lung function using 133-xenon (/sup 133/Xe) and a multiprobe computerized instrumentation system documented a reduction of perfusion to 22 percent and ventilation to 6 percent of the total. There was negligible washout of intravenously injected /sup 133/Xe from the left lung consistent with air trapping. Four days after left mainstem bronchial sleeve resection, perfusion, ventilation and washout of injected xenon had significantly improved and by four months postresection, all measurements were virtually normal, although complete restoration of perfusion in relation to ventilation was delayed. Regional lung function studied with a multiprobe system in this patient provided a clinical model for the study of ventilation and perfusion inter-relationships in large airway obstruction and demonstrated that a prolonged time may be required for return of perfusion to normal

  19. Laws of physics help explain capillary non-perfusion in diabetic retinopathy.

    Science.gov (United States)

    Stefánsson, E; Chan, Y K; Bek, T; Hardarson, S H; Wong, D; Wilson, D I

    2018-02-01

    The purpose is to use laws of physics to elucidate the mechanisms behind capillary non-perfusion in diabetic retinopathy. In diabetic retinopathy, loss of pericytes weakens capillary walls and the vessel dilates. A dilated capillary has reduced resistance to flow, therefore increased flow in that vessel and decreased in adjoining capillaries. A preferential shunt vessel is thus formed from the dilated capillary and the adjacent capillaries become non-perfused. We apply the laws of Laplace and Hagen-Poiseuille to better understand the phenomena that lead to capillary non-perfusion. These laws of physics can give a foundation for physical or mathematical models to further elucidate this field of study. The law of Laplace predicts that a weaker vessel wall will dilate, assuming constant transmural pressure. The Hagen-Poiseuille equation for flow and the Ostwald-de Waele relationship for viscosity predict that a dilated vessel will receive a higher portion of the fluid flow than the adjoining capillaries. Viscosity will decrease in the dilated vessel, furthering the imbalance and resulting in a patch of non-perfused capillaries next to the dilated 'preferential' shunt vessel. Physical principles support or inspire novel hypotheses to explain poorly understood phenomena in ophthalmology. This thesis of pericyte death and capillary remodelling, which was first proposed by Cogan and Kuwabara, already agrees with histological and angiographical observations in diabetic retinopathy. We have shown that it is also supported by classical laws of physics.

  20. Image quality in CT perfusion imaging of the brain. The role of iodine concentration

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, Matthias; Bueltmann, Eva; Bode-Schnurbus, Lucas; Koenen, Dirk; Mielke, Eckhart; Heuser, Lothar [Knappschaftskrankenhaus Langendreer, Department of Diagnostic and Interventional Radiology and Nuclear Medicine, Ruhr-University Bochum, Bochum (Germany)

    2007-01-15

    The purpose of this study was to evaluate the impact of various iodine contrast concentrations on image quality in computed tomography (CT) perfusion studies. Twenty-one patients with suspicion of cerebral ischemia underwent perfusion CT using two different iodine contrast concentrations: 11 patients received iomeprol 300 (iodine concentration: 300 mg/ml) while ten received the same volume of iomeprol 400 (iodine concentration: 400 mg/ml). Scan parameters were kept constant for both groups. Maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and time to peak (TTP) were calculated from two adjacent slices. Quantitative comparisons were based on measurements of the maximum enhancement [Hounsfield units (HU)] and signal-to-noise index (SNI) on CBF, CBV, and TTP images. Determinations of grey-to-white-matter delineation for each iodine concentration were performed by two blinded readers. Only data from the non-ischemic hemispheres were considered. Both maximum enhancement and SNI values were higher after iomeprol 400, resulting in significantly better image quality in areas of low perfusion. No noteworthy differences were found for normal values of CBF, CBV, and TTP. Qualitative assessment of grey/white matter contrast on CBF and CBV maps revealed better performance for iomeprol 400. For brain perfusion studies, highly concentrated contrast media such as iomeprol 400 is superior to iomeprol 300. (orig.)

  1. Arterial spin-labelling perfusion MRI and outcome in neonates with hypoxic-ischemic encephalopathy

    International Nuclear Information System (INIS)

    Vis, Jill B. de; Hendrikse, Jeroen; Petersen, Esben T.; Vries, Linda S. de; Bel, Frank van; Alderliesten, Thomas; Negro, Simona; Groenendaal, Floris; Benders, Manon J.N.L.

    2015-01-01

    Hyperperfusion may be related to outcome in neonates with hypoxic-ischemic encephalopathy (HIE). The purpose of this study was to evaluate whether arterial spin labelling (ASL) perfusion is associated with outcome in neonates with HIE and to compare the predictive value of ASL MRI to known MRI predictive markers. Twenty-eight neonates diagnosed with HIE and assessed with MR imaging (conventional MRI, diffusion-weighted MRI, MR spectroscopy [MRS], and ASL MRI) were included. Perfusion in the basal ganglia and thalami was measured. Outcome at 9 or 18 months of age was scored as either adverse (death or cerebral palsy) or favourable. The median (range) perfusion in the basal ganglia and thalami (BGT) was 63 (28-108) ml/100 g/min in the neonates with adverse outcome and 28 (12-51) ml/100 g/min in the infants with favourable outcome (p 2 = 0.86, p < 0.001). Higher ASL perfusion values in neonates with HIE are associated with a worse neurodevelopmental outcome. A combination of the MRS and ASL MRI information is the best predictor of outcome. (orig.)

  2. Arterial spin-labelling perfusion MRI and outcome in neonates with hypoxic-ischemic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Vis, Jill B. de; Hendrikse, Jeroen [University Medical Center Utrecht, Department of Radiology, HP E 01.132, P.O. Box 85500, Utrecht (Netherlands); Petersen, Esben T. [University Medical Center Utrecht, Department of Radiology, HP E 01.132, P.O. Box 85500, Utrecht (Netherlands); University Medical Center Utrecht, Department of Radiotherapy, Utrecht (Netherlands); Vries, Linda S. de; Bel, Frank van; Alderliesten, Thomas; Negro, Simona; Groenendaal, Floris; Benders, Manon J.N.L. [Wilhelmina Children' s Hospital/University Medical Center Utrecht, Department of Neonatology, Utrecht (Netherlands)

    2015-01-15

    Hyperperfusion may be related to outcome in neonates with hypoxic-ischemic encephalopathy (HIE). The purpose of this study was to evaluate whether arterial spin labelling (ASL) perfusion is associated with outcome in neonates with HIE and to compare the predictive value of ASL MRI to known MRI predictive markers. Twenty-eight neonates diagnosed with HIE and assessed with MR imaging (conventional MRI, diffusion-weighted MRI, MR spectroscopy [MRS], and ASL MRI) were included. Perfusion in the basal ganglia and thalami was measured. Outcome at 9 or 18 months of age was scored as either adverse (death or cerebral palsy) or favourable. The median (range) perfusion in the basal ganglia and thalami (BGT) was 63 (28-108) ml/100 g/min in the neonates with adverse outcome and 28 (12-51) ml/100 g/min in the infants with favourable outcome (p < 0.01). The area-under-the-curve was 0.92 for ASL MRI, 0.97 for MRI score, 0.96 for Lac/NAA and 0.92 for ADC in the BGT. The combination of Lac/NAA and ASL MRI results was the best predictor of outcome (r {sup 2} = 0.86, p < 0.001). Higher ASL perfusion values in neonates with HIE are associated with a worse neurodevelopmental outcome. A combination of the MRS and ASL MRI information is the best predictor of outcome. (orig.)

  3. Quantitative study on lung volume and lung perfusion using SPECT and CT in thoracal tumors

    International Nuclear Information System (INIS)

    Beyer-Enke, S.A.; Goerich, J.; Strauss, L.G.

    1988-01-01

    22 patients with space occupying lesions in the thoracal region were investigated by computer tomography and by perfusion scintigraphy using SPECT. In order to evaluate the CT images quantitatively, the lung volume was determined using approximation method and compared with the perfusion in the SPECT study. For this, anatomically equivalent transaxial SPECT slices had been coordinated to the CT slices. Between the determined lung volumes and the activity in the ocrresponding layers, a statistically significant correlation was found. It could be shown that the stronger perfusion, frequently observed at the right side of the healthy lung, may be explained by an higher volume of the right pulmonary lobe. Whereas in benign displacing processes the relation activity to volume was similar to the one of the healthy lung, a strongly reduced perfusion together with inconspicuous lung volumes became apparent with malignant tumors. In addition to the great morphological evidence of CT and SPECT studies, additional informations regarding the dignity of displacing processes may be derived from the quantitative evaluation of both methods. (orig.) [de

  4. Effects of thyroid state on respiration of perfused rat and guinea pig hearts

    International Nuclear Information System (INIS)

    Read, L.C.; Wallace, P.G.; Berry, M.N.

    1987-01-01

    The effects of thyroid state on the respiration of the isolated heart were investigated using retrograde perfused rat and guinea pig hearts. In both species, hypothyroidism caused a marked depression in circulating thyroid hormone concentrations and in the respiration of the isolated, retrograde perfused heart. Hypothyroidism was caused by injecting animals with Na 131 I. The effects on myocardial respiration could be attributed to changes in the contraction frequency and in the oxygen consumption per beat, with little contribution from basal respiration. Treatment of animals with thyroxine elevated plasma thyroid hormones to a similar extent in rats and guinea pigs. In the latter, thyroxine treatment was associated with substantial increases in the contraction frequency and the oxygen consumption per beat of the isolated heart. In contrast, only small changes were apparent in the retrograde perfused rat heart, observations that were confirmed in rat hearts perfused at near physiological work loads. It was concluded that rat hearts isolated from normal animals function at near maximal thyroid state, in contrast to the guinea pig heart, which requires higher circulating concentrations of thyroid hormones to attain maximal responses

  5. Characteristics of myocardial perfusion imaging and coronary artery angiography in patients of NIDDM complicated with AMI

    International Nuclear Information System (INIS)

    Zhao Peiqin; Zhao Jinhua; Qin Mingzhao; Dai HaoJie; Zhang Runwu; Xiao Fen

    2001-01-01

    Objective: To investigate the characteristic changes of myocardial perfusion imaging and coronary artery angiography in patients of acute myocardial infarction (AMI) with underlined type 2 diabetes mellitus. Methods: 25 type 2 diabetes mellitus patients were enrolled for having clinical manifestation of AMI. Ten inpatients with AMI of simple coronary heart disease origin were served as controls. All subjects underwent both myocardial perfusion imagings (resting and nitroglycerine invention) and coronary artery angiography. Results: Compared to controls (40%), type 2 diabetes mellitus + AMI group had higher rate of multivessel disease (60%). For type 2 diabetes mellitus + AMI patients, 129/400 segments (32.25%) showed fixed defect, 25/160 segments (15.62%) in controls. Conclusions: For type 2 diabetes mellitus + AMI group, myocardial perfusion defects are widely distributed and multivessel or severe stenosis is more often presented. Good correlation exists between abnormal segments and angiographic lesions in both the number of segments involved and the severity of the lesions. Radionuclide myocardial perfusion is therefore considered a useful screening test not inferior to angiography, especially for those who are not tolerant enough to undergoing angiography

  6. Myocardial perfusion MRI with sliding-window conjugate-gradient HYPR.

    Science.gov (United States)

    Ge, Lan; Kino, Aya; Griswold, Mark; Mistretta, Charles; Carr, James C; Li, Debiao

    2009-10-01

    First-pass perfusion MRI is a promising technique for detecting ischemic heart disease. However, the diagnostic value of the method is limited by the low spatial coverage, resolution, signal-to-noise ratio (SNR), and cardiac motion-related image artifacts. In this study we investigated the feasibility of using a method that combines sliding window and CG-HYPR methods (SW-CG-HYPR) to reduce the acquisition window for each slice while maintaining the temporal resolution of one frame per heartbeat in myocardial perfusion MRI. This method allows an increased number of slices, reduced motion artifacts, and preserves the relatively high SNR and spatial resolution of the "composite images." Results from eight volunteers demonstrate the feasibility of SW-CG-HYPR for accelerated myocardial perfusion imaging with accurate signal intensity changes of left ventricle blood pool and myocardium. Using this method the acquisition time per cardiac cycle was reduced by a factor of 4 and the number of slices was increased from 3 to 8 as compared to the conventional technique. The SNR of the myocardium at peak enhancement with SW-CG-HYPR (13.83 +/- 2.60) was significantly higher (P < 0.05) than the conventional turbo-FLASH protocol (8.40 +/- 1.62). Also, the spatial resolution of the myocardial perfection images was significantly improved. SW-CG-HYPR is a promising technique for myocardial perfusion MRI. (c) 2009 Wiley-Liss, Inc.

  7. Quantitative assessment of angiographic perfusion reduction using color-coded digital subtraction angiography during transarterial chemoembolization.

    Science.gov (United States)

    Wang, Ji; Cheng, Jie-Jun; Huang, Kai-Yi; Zhuang, Zhi-Guo; Zhang, Xue-Bin; Chi, Jia-Chang; Hua, Xiao-Lan; Xu, Jian-Rong

    2016-03-01

    The aim of this study was to develop a quantitative measurement of perfusion reduction using color-coded digital subtraction angiography (ccDSA) to monitor intra-procedural arterial stasis during TACE. A total number of 35 patients with hepatocellular carcinoma who had undergone TACE were enrolled into the study. Pre- and post-two-dimensional digital subtraction angiography scans were conducted with same protocol and post-processed with ccDSA prototype software. Time-contrast-intensity (CI[t]) curve was obtained by region-of-interest (ROI) measurement on the generated ccDSA image. Quantitative 2D perfusion parameters time to peak, area under the curve (AUC), maximum upslope, and contrast intensity peak (CI-Peak) derived from the ROI-based CI[t] curve for pre- and post-TACE were evaluated to assess the reduction of antegrade blood flow and tumor blush. Relationships between 2D perfusion parameters, subjective angiographic chemoembolization endpoint (SACE) scale, and clinical outcomes were analyzed. Area normalized AUC and CI-Peak revealed significant reduction after the TACE (P SACE level III and a reduction ranging from 60% to 70% was equivalent to SACE level IV. For intermediate reduction (SACE level III), better tumor response was found after TACE rather than a higher reduction (SACE level IV). ccDSA application provides an objective approach to quantify the perfusion reduction and subjectively evaluate the arterial stasis of antegrade blood flow and tumor blush caused by TACE.

  8. Blood temperature and perfusion to exercising and non-exercising human limbs.

    Science.gov (United States)

    González-Alonso, José; Calbet, José A L; Boushel, Robert; Helge, Jørn W; Søndergaard, Hans; Munch-Andersen, Thor; van Hall, Gerrit; Mortensen, Stefan P; Secher, Niels H

    2015-10-01

    What is the central question of this study? Temperature-sensitive mechanisms are thought to contribute to blood-flow regulation, but the relationship between exercising and non-exercising limb perfusion and blood temperature is not established. What is the main finding and its importance? The close coupling among perfusion, blood temperature and aerobic metabolism in exercising and non-exercising extremities across different exercise modalities and activity levels and the tight association between limb vasodilatation and increases in plasma ATP suggest that both temperature- and metabolism-sensitive mechanisms are important for the control of human limb perfusion, possibly by activating ATP release from the erythrocytes. Temperature-sensitive mechanisms may contribute to blood-flow regulation, but the influence of temperature on perfusion to exercising and non-exercising human limbs is not established. Blood temperature (TB ), blood flow and oxygen uptake (V̇O2) in the legs and arms were measured in 16 healthy humans during 90 min of leg and arm exercise and during exhaustive incremental leg or arm exercise. During prolonged exercise, leg blood flow (LBF) was fourfold higher than arm blood flow (ABF) in association with higher TB and limb V̇O2. Leg and arm vascular conductance during exercise compared with rest was related closely to TB (r(2) = 0.91; P exercise, LBF increased in association with elevations in TB and limb V̇O2, whereas ABF, arm TB and V̇O2 remained largely unchanged. During incremental arm exercise, both ABF and LBF increased in relationship to similar increases in V̇O2. In 12 trained males, increases in femoral TB and LBF during incremental leg exercise were mirrored by similar pulmonary artery TB and cardiac output dynamics, suggesting that processes in active limbs dominate central temperature and perfusion responses. The present data reveal a close coupling among perfusion, TB and aerobic metabolism in exercising and non

  9. Blood temperature and perfusion to exercising and non‐exercising human limbs

    Science.gov (United States)

    Calbet, José A. L.; Boushel, Robert; Helge, Jørn W.; Søndergaard, Hans; Munch‐Andersen, Thor; van Hall, Gerrit; Mortensen, Stefan P.; Secher, Niels H.

    2015-01-01

    New Findings What is the central question of this study? Temperature‐sensitive mechanisms are thought to contribute to blood‐flow regulation, but the relationship between exercising and non‐exercising limb perfusion and blood temperature is not established. What is the main finding and its importance? The close coupling among perfusion, blood temperature and aerobic metabolism in exercising and non‐exercising extremities across different exercise modalities and activity levels and the tight association between limb vasodilatation and increases in plasma ATP suggest that both temperature‐ and metabolism‐sensitive mechanisms are important for the control of human limb perfusion, possibly by activating ATP release from the erythrocytes. Temperature‐sensitive mechanisms may contribute to blood‐flow regulation, but the influence of temperature on perfusion to exercising and non‐exercising human limbs is not established. Blood temperature (T B), blood flow and oxygen uptake (V˙O2) in the legs and arms were measured in 16 healthy humans during 90 min of leg and arm exercise and during exhaustive incremental leg or arm exercise. During prolonged exercise, leg blood flow (LBF) was fourfold higher than arm blood flow (ABF) in association with higher T B and limb V˙O2. Leg and arm vascular conductance during exercise compared with rest was related closely to T B (r 2 = 0.91; P exercise, LBF increased in association with elevations in T B and limb V˙O2, whereas ABF, arm T B and V˙O2 remained largely unchanged. During incremental arm exercise, both ABF and LBF increased in relationship to similar increases in V˙O2. In 12 trained males, increases in femoral T B and LBF during incremental leg exercise were mirrored by similar pulmonary artery T B and cardiac output dynamics, suggesting that processes in active limbs dominate central temperature and perfusion responses. The present data reveal a close coupling among perfusion, T B and aerobic metabolism

  10. Assessment value of quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Jiang-Xia Lei

    2016-10-01

    Full Text Available Objective: To analyze the assessment value of the quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer. Methods: A total of 58 patients with space-occupying pancreatic lesions were divided into 20 patients with pancreatic cancer and 38 patients with benign pancreatic lesions after pancreatic CT perfusion. Patients with pancreatic cancer received palliative surgery, and the cancer tissue and para-carcinoma tissue specimens were collected during operation. The differences in pancreatic CT perfusion scanning parameter values and serum tumor marker levels were compared between patients with pancreatic cancer and patients with benign pancreatic lesions, mRNA expression levels of malignant molecules in pancreatic cancer tissue and para-carcinoma tissue were further determined, and the correlation between pancreatic CT perfusion scanning parameter values and malignant degree of pancreatic cancer was analyzed. Results: CT perfusion scanning BF, BV and Per values of patients with pancreatic cancer were lower than those of patients with benign pancreatic lesions; serum CA19-9, CEA, CA125 and CA242 levels were higher than those of patients with benign pancreatic lesions (P<0.05; mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue samples were higher than those in paracarcinoma tissue samples, and mRNA expression levels of P53 and Bax were lower than those in para-carcinoma tissue samples (P<0.05; CT perfusion scanning parameters BF, BV and Per values of patients with pancreatic cancer were negatively correlated with CA19-9, CEA, CA125 and CA242 levels in serum as well as mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue, and positively correlated with mRNA expression levels of P53 and Bax in pancreatic cancer tissue (P<0.05. Conclusions: Pancreatic CT perfusion scanning is a reliable way to judge the malignant degree of pancreatic cancer and plays a

  11. Whole-brain dynamic CT angiography and perfusion imaging

    Energy Technology Data Exchange (ETDEWEB)

    Orrison, W.W. [CHW Nevada Imaging Company, Nevada Imaging Centers, Spring Valley, Las Vegas, NV (United States); College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Department of Medical Education, University of Nevada School of Medicine, Reno, NV (United States); Snyder, K.V.; Hopkins, L.N. [Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Buffalo, NY (United States); Roach, C.J. [School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States); Ringdahl, E.N. [Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV (United States); Nazir, R. [Shifa International Hospital, Islamabad (Pakistan); Hanson, E.H., E-mail: eric.hanson@amigenics.co [College of Osteopathic Medicine, Touro University Nevada, Henderson, NV (United States); Department of Health Physics and Diagnostic Sciences, University of Nevada Las Vegas, Las Vegas, NV (United States); Advanced Medical Imaging and Genetics (Amigenics), Las Vegas, NV (United States)

    2011-06-15

    The availability of whole brain computed tomography (CT) perfusion has expanded the opportunities for analysing the haemodynamic parameters associated with varied neurological conditions. Examples demonstrating the clinical utility of whole-brain CT perfusion imaging in selected acute and chronic ischaemic arterial neurovascular conditions are presented. Whole-brain CT perfusion enables the detection and focused haemodynamic analyses of acute and chronic arterial conditions in the central nervous system without the limitation of partial anatomical coverage of the brain.

  12. Simultaneous Multiagent Hyperpolarized 13C Perfusion Imaging

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Bok, Robert A.; Reed, Galen D.

    2014-01-01

    in simulations. "Tripolarized" perfusion MRI methods were applied to initial preclinical studies with differential conditions of vascular permeability, in normal mouse tissues and advanced transgenic mouse prostate tumors. Results: Dynamic imaging revealed clear differences among the individual tracer...... distributions. Computed permeability maps demonstrated differential permeability of brain tissue among the tracers, and tumor perfusion and permeability were both elevated over values expected for normal tissues. Conclusion: Tripolarized perfusion MRI provides new molecular imaging measures for specifically...

  13. Peripheral blood mononuclear cells of patients with latent autoimmune diabetes secrete higher levels of pro- & anti-inflammatory cytokines compared to those with type-1 diabetes mellitus following in vitro stimulation with β-cell autoantigens

    Directory of Open Access Journals (Sweden)

    Darshan Badal

    2017-01-01

    Interpretation & conclusions: There are differences in the portfolio of cytokine secretion in diabetic subjects with varying rates of β-cell destruction as LADA subjects secrete higher levels of both pro- and anti-inflammatory cytokines on exposure to β-cell autoantigens, thus highlighting another distinguishing feature in the pathophysiology of the two forms of autoimmune diabetes.

  14. The value of perfusion CT in predicting the short-term response to synchronous radiochemotherapy for cervical squamous cancer

    International Nuclear Information System (INIS)

    Li, Xiang Sheng; Fan, Hong Xia; Zhu, Hong Xian; Song, Yun Long; Zhou, Chun Wu

    2012-01-01

    To determine the value of the perfusion parameters in predicting short-term tumour response to synchronous radiochemotherapy for cervical squamous carcinoma. Ninety-three patients with cervical squamous carcinoma later than stage IIB were included in this study. Perfusion CT was performed for all these patients who subsequently received the same synchronous radiochemotherapy. The patients were divided into responders and non-responders according to short-term response to treatment. Baseline perfusion parameters of the two groups were compared. The perfusion parameters that might affect treatment effect were analysed by using a multivariate multi-regression analysis. The responders group had higher baseline permeability-surface area product (PS) and blood volume (BV) values than the non-responders group (P 0.05). At multivariate multi-regression analysis, BV, PS and tumour size were significant factors in the prediction of treatment effect. Small tumours usually had high PS and BV values, and thus had a good treatment response. Perfusion CT can provide some helpful information for the prediction of the short-term effect. Synchronous radiochemotherapy may be more effective in cervical squamous carcinoma with higher baseline PS and BV. (orig.)

  15. Effect of Defocused CO2 Laser on Equine Tissue Perfusion

    Directory of Open Access Journals (Sweden)

    Bergh A

    2006-03-01

    Full Text Available Treatment with defocused CO2 laser can have a therapeutic effect on equine injuries, but the mechanisms involved are unclear. A recent study has shown that laser causes an increase in equine superficial tissue temperature, which may result in an increase in blood perfusion and a stimulating effect on tissue regeneration. However, no studies have described the effects on equine tissue perfusion. The aim of the present study was to investigate the effect of defocused CO2 laser on blood perfusion and to correlate it with temperature in skin and underlying muscle in anaesthetized horses. Differences between clipped and unclipped haircoat were also assessed. Eight horses and two controls received CO2 laser treatment (91 J/cm2 in a randomised order, on a clipped and unclipped area of the hamstring muscles, respectively. The significant increase in clipped skin perfusion and temperature was on average 146.3 ± 33.4 perfusion units (334% and 5.5 ± 1.5°C, respectively. The significant increase in perfusion and temperature in unclipped skin were 80.6 ± 20.4 perfusion units (264% and 4.8 ± 1.4°C. No significant changes were seen in muscle perfusion or temperature. In conclusion, treatment with defocused CO2 laser causes a significant increase in skin perfusion, which is correlated to an increase in skin temperature.

  16. Perfusion lung scanning: differentiation of primary from thromboembolic pulmonary hypertension

    International Nuclear Information System (INIS)

    Lisbona, R.; Kreisman, H.; Novales-Diaz, J.; Derbekyan, V.

    1985-01-01

    Of eight patients with pulmonary arterial hypertension, final diagnosis established by autopsy or angiography, four had primary hypertension and four hypertension from thromboembolism. The perfusion lung scan was distinctly different in the two groups. The lung scan in primary pulmonary hypertension was associated with nonsegmental, patchy defects of perfusion, while in thromboembolic hypertensives it was characterized by segmental and/or lobar defects of perfusion with or without subsegmental defects. The perfusion lung scan is a valuable, noninvasive study in the evaluation of the patient with pulmonary hypertension of undetermined cause and in the exclusion of occult large-vessel pulmonary thromboembolism

  17. Higher Levels of c-Met Expression and Phosphorylation Identify Cell Lines With Increased Sensitivity to AMG-458, a Novel Selective c-Met Inhibitor With Radiosensitizing Effects

    International Nuclear Information System (INIS)

    Li Bo; Torossian, Artour; Sun, Yunguang; Du, Ruihong; Dicker, Adam P.; Lu Bo

    2012-01-01

    Purpose: c-Met is overexpressed in some non-small cell lung cancer (NSCLC) cell lines and tissues. Cell lines with higher levels of c-Met expression and phosphorylation depend on this receptor for survival. We studied the effects of AMG-458 on 2 NSCLC cell lines. Methods and Materials: 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl) -2H-tetrazolium assays assessed the sensitivities of the cells to AMG-458. Clonogenic survival assays illustrated the radiosensitizing effects of AMG-458. Western blot for cleaved caspase 3 measured apoptosis. Immunoblotting for c-Met, phospho-Met (p-Met), Akt/p-Akt, and Erk/p-Erk was performed to observe downstream signaling. Results: AMG-458 enhanced radiosensitivity in H441 but not in A549. H441 showed constitutive phosphorylation of c-Met. A549 expressed low levels of c-Met, which were phosphorylated only in the presence of exogenous hepatocyte growth factor. The combination of radiation therapy and AMG-458 treatment was found to synergistically increase apoptosis in the H441 cell line but not in A549. Radiation therapy, AMG-458, and combination treatment were found to reduce p-Akt and p-Erk levels in H441 but not in A549. H441 became less sensitive to AMG-458 after small interfering RNA knockdown of c-Met; there was no change in A549. After overexpression of c-Met, A549 became more sensitive, while H441 became less sensitive to AMG-458. Conclusions: AMG-458 was more effective in cells that expressed higher levels of c-Met/p-Met, suggesting that higher levels of c-Met and p-Met in NSCLC tissue may classify a subset of tumors that are more sensitive to molecular therapies against this receptor.

  18. The correlation of CT perfusion imaging with microvessel density and vascular endothelial growth factor in hepatic alveolar echinococcosis

    International Nuclear