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Ruspini LC, Øren PE, Berg S, Masalmeh S, Bultreys T, Taberner C, Sorop T, Marcelis F, Appel M, Freeman J, Wilson OB. Multiscale Digital Rock Analysis for Complex Rocks. Transp Porous Media 2021. [DOI: 10.1007/s11242-021-01667-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Karlsons K, de Kort DW, Sederman AJ, Mantle MD, Freeman JJ, Appel M, Gladden LF. Characterizing pore-scale structure-flow correlations in sedimentary rocks using magnetic resonance imaging. Phys Rev E 2021; 103:023104. [PMID: 33736007 DOI: 10.1103/physreve.103.023104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/12/2021] [Indexed: 12/11/2022]
Abstract
Quantitative, three-dimensional (3D) spatially resolved magnetic resonance flow imaging (flow MRI) methods are presented to characterize structure-flow correlations in a 4-mm-diameter plug of Ketton limestone rock using undersampled k- and q-space data acquisition methods combined with compressed sensing (CS) data reconstruction techniques. The acquired MRI data are coregistered with an X-ray microcomputed tomography (μCT) image of the same rock sample, allowing direct correlation of the structural features of the rock with local fluid transport characteristics. First, 3D velocity maps acquired at 35 μm isotropic spatial resolution showed that the flow was highly heterogeneous, with ∼10% of the pores carrying more than 50% of the flow. Structure-flow correlations were found between the local flow velocities through pores and the size and topology (coordination number) associated with these pores. These data show consistent trends with analogous data acquired for flow through a packing of 4-mm-diameter spheres, which may be due to the microstructure of Ketton rock being a consolidation of approximately spherical grains. Using two-dimensional and 3D visualization of coregistered μCT images and velocity maps, complex pore-scale flow patterns were identified. Second, 3D spatially resolved propagators were acquired at 94 μm isotropic spatial resolution. Flow dispersion within the rock was examined by analyzing each of the 331 776 local propagators as a function of observation time. Again, the heterogeneity of flow within the rock was shown. Quantification of the mean and standard deviation of each of the local propagators showed enhanced mixing occurring within the pore space at longer observation times. These spatially resolved measurements also enable investigation of the length scale of a representative elementary volume. It is shown that for a 4-mm-diameter plug this length scale is not reached.
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Affiliation(s)
- K Karlsons
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - D W de Kort
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.,Shell Technology Centre Amsterdam, Shell Global Solutions International B.V., Grasweg 31, 1031 HW Amsterdam, the Netherlands
| | - A J Sederman
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - M D Mantle
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - J J Freeman
- Shell Technology Center Houston, Shell Exploration and Production Inc., 3333 Highway 6 S, Houston, Texas 77082, USA
| | - M Appel
- Shell Technology Centre Amsterdam, Shell Global Solutions International B.V., Grasweg 31, 1031 HW Amsterdam, the Netherlands
| | - L F Gladden
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
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Han J, Heinemann L, Ginsberg BH, Alva S, Appel M, Bess S, Chen KY, Freckmann G, Harris DR, Hartwig M, Hinzmann R, Kerr D, Krouwer J, Morrow L, Nichols J, Pfützner A, Pleus S, Rice M, Sacks DB, Schlueter K, Vesper HW, Klonoff DC. The YSI 2300 Analyzer Replacement Meeting Report. J Diabetes Sci Technol 2020; 14:679-686. [PMID: 32174135 PMCID: PMC7576944 DOI: 10.1177/1932296820911471] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This is a summary report of the most important aspects discussed during the YSI 2300 Analyzer Replacement Meeting. The aim is to provide the interested reader with an overview of the complex topic and propose solutions for the current issue. This solution should not only be adequate for the United States or Europe markets but also for all other countries. The meeting addendum presents three outcomes of the meeting.
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Affiliation(s)
- Julia Han
- Diabetes Research Institute, Mills-Peninsula Medical Center, San Mateo, CA, USA
| | - Lutz Heinemann
- Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany
| | | | | | | | | | - Kong Y. Chen
- National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Guido Freckmann
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | | | | | | | - David Kerr
- Sansum Diabetes Research Institute, Santa Barbara, CA, USA
| | | | | | - James Nichols
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | | | - Stefan Pleus
- Institut für Diabetes-Technologie Forschungs- und Entwicklungsgesellschaft mbH, Ulm, Germany
| | - Mark Rice
- Vanderbilt University School of Medicine, Nashville, TN, USA
| | | | | | | | - David C. Klonoff
- Diabetes Research Institute, Mills-Peninsula Medical Center, San Mateo, CA, USA
- David C. Klonoff, MD, FACP, FRCP (Edin), Fellow AIMBE, Medical Director, Diabetes Research Institute, Mills-Peninsula Medical Center, 100 South San Mateo Drive, Room 5147, San Mateo, CA 94401, USA.
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Karlsons K, DE Kort DW, Sederman AJ, Mantle MD, DE Jong H, Appel M, Gladden LF. Identification of sampling patterns for high-resolution compressed sensing MRI of porous materials: 'learning' from X-ray microcomputed tomography data. J Microsc 2019; 276:63-81. [PMID: 31587277 DOI: 10.1111/jmi.12837] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/10/2019] [Accepted: 10/01/2019] [Indexed: 11/30/2022]
Abstract
There exists a strong motivation to increase the spatial resolution of magnetic resonance imaging (MRI) acquisitions so that MRI can be used as a microscopy technique in the study of porous materials. This work introduces a method for identifying novel data sampling patterns to achieve undersampling schemes for compressed sensing MRI (CS-MRI) acquisitions, enabling 3D spatial resolutions of 17.6 µm to be achieved. A data-driven learning approach is used to derive k-space undersampling schemes for 3D MRI acquisitions from 3D X-ray microcomputed tomography (µCT) datasets acquired at a higher spatial resolution than can be acquired using MRI. The performance of the new sampling approach was compared to other, well-established sampling strategies using simulated MRI data obtained from high-resolution µCT images of rock core plugs. These simulations were performed for a range of different k-space sampling fractions (0.125-0.375) using images of Ketton limestone. The method was then extended to consideration of imaging Estaillades limestone and Fontainebleau sandstone. The results show that the new sampling approach performs as well as or better than conventional variable density sampling and without need for time-consuming parameter optimisation. Further, a bespoke sampling pattern is produced for each rock type. The novel undersampling strategy was employed to acquire 3D magnetic resonance images of a Ketton limestone rock at spatial resolutions of 35 and 17.6 µm. The ability of the k-space sampling scheme produced using the new approach in enabling reconstruction of the pore space characteristics of the rock was then demonstrated by benchmarking against the pore space statistics obtained from high-resolution µCT data. The MRI data acquired at 17.6 µm resolution gave excellent agreement with the pore size distribution obtained from the X-ray microcomputed tomography dataset, while the pore coordination number distribution obtained from the MRI data was slightly skewed to lower coordination numbers. This approach provides a method of producing a k-space undersampling pattern for MRI acquisition at a spatial resolution for which a fully sampled acquisition at that spatial resolution would be impractically long. The approach can be easily extended to other CS-MRI techniques, such as spatially resolved flow and relaxation time mapping. LAY DESCRIPTION: Magnetic resonance imaging (MRI) is widely used to study the microstructure of, and fluid transport phenomena in porous media relevant for engineering applications. A major application is the study of water and hydrocarbon transport in porous sedimentary rocks, which typically have pore sizes smaller than 100 µm. The spatial resolution of routine MRI acquisitions, however, is limited to several hundred µm due to the relatively low sensitivity of the magnetic resonance method. Therefore, there exists a strong motivation to increase the spatial resolution of MRI by one to two orders of magnitude to be able to study these rocks at a pore scale. This work reports the initial step towards achieving this. Three-dimensional images of rock pore structure are acquired at both 35 and 17.6 µm spatial resolution. In ongoing work, these methods are now being incorporated into magnetic resonance velocity imaging methods, thereby enabling imaging of both pore structure and hydrodynamics at these much higher spatial resolutions than were hitherto possible. Although X-ray microcomputed tomography (µCT) produces high spatial resolution images, it is far more limited in being able to spatially map transport processes (i.e. flow) in porous media. This work reports a strategy for accelerating the image acquisition time such that sufficient signal-to-noise ratio (SNR) is achieved to increase the spatial resolution, that is, the voxel size within which there is sufficient SNR within the resulting image. To achieve this, a technique known as compressed sensing is used which exploits undersampling of the acquired data relative to the standard fully sampled image. In MRI, data are acquired in so-called k-space and Fourier transformed to yield the real space image. The challenge, when undersampling, is to optimise the specific points in k-space that are acquired because these will influence the quality of the resulting image. This work reports a straightforward, robust strategy for identifying the optimal sets of k-space points to acquire. The method introduced uses simulated MRI images calculated from high-resolution µCT images of the rocks of interest, from which optimised MRI sampling patterns are obtained. The method does not require any optimisation of parameters for its implementation, which is a significant advantage compared to other strategies. Moreover, we show that the pore space characteristics of the acquired MRI images are in excellent agreement with the same characteristics obtained from a high-resolution µCT image.
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Affiliation(s)
- K Karlsons
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, U.K
| | - D W DE Kort
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, U.K
| | - A J Sederman
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, U.K
| | - M D Mantle
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, U.K
| | - H DE Jong
- Shell Technology Center Houston, Shell Exploration and Production Inc., Houston, Texas, U.S.A
| | - M Appel
- Shell Technology Centre Amsterdam, Shell Global Solutions International B.V., Amsterdam, The Netherlands
| | - L F Gladden
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, U.K
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de Kort DW, Hertel SA, Appel M, de Jong H, Mantle MD, Sederman AJ, Gladden LF. Under-sampling and compressed sensing of 3D spatially-resolved displacement propagators in porous media using APGSTE-RARE MRI. Magn Reson Imaging 2019; 56:24-31. [DOI: 10.1016/j.mri.2018.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 08/26/2018] [Accepted: 08/27/2018] [Indexed: 11/24/2022]
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de Kort DW, Reci A, Ramskill NP, Appel M, de Jong H, Mantle MD, Sederman AJ, Gladden LF. Acquisition of spatially-resolved displacement propagators using compressed sensing APGSTE-RARE MRI. J Magn Reson 2018; 295:45-56. [PMID: 30096552 DOI: 10.1016/j.jmr.2018.07.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/14/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
A method is presented for accelerating the acquisition of spatially-resolved displacement propagators via under-sampling of an Alternating Pulsed Gradient Stimulated Echo - Rapid Acquisition with Relaxation Enhancement (APGSTE-RARE) data acquisition with compressed sensing image reconstruction. The method was demonstrated with respect to the acquisition of 2D spatially-resolved displacement propagators of water flowing through a packed bed of hollow cylinders. The q,k-space was under-sampled according to variable-density pseudo-random sampling patterns. The quality of compressed sensing reconstructions of spatially-resolved propagators at a range of sampling fractions was assessed using the peak signal-to-noise ratio (PSNR) as a quality metric. Propagators of good quality (PSNR 33.2 dB) were reconstructed from only 6.25% of all data points in q,k-space, resulting in a reduction in the data acquisition time from 4 h to 14 min. The spatially-resolved propagators were reconstructed using both the total variation and nuclear norm sparsifying transforms; use of total variation resulted in a slightly higher quality of the reconstructed image in most cases. To illustrate the power of this method to characterise heterogeneous flow in porous media, the method is applied to the characterisation of flow in a vuggy carbonate rock.
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Affiliation(s)
- Daan W de Kort
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Andi Reci
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Nicholas P Ramskill
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Matthias Appel
- Shell Technology Center, 3333 Highway 6 S, Houston, TX 77082, USA
| | - Hilko de Jong
- Shell Technology Center, 3333 Highway 6 S, Houston, TX 77082, USA
| | - Michael D Mantle
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Andrew J Sederman
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom
| | - Lynn F Gladden
- Magnetic Resonance Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, United Kingdom.
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Ramskill NP, Bush I, Sederman AJ, Mantle MD, Benning M, Anger BC, Appel M, Gladden LF. Fast imaging of laboratory core floods using 3D compressed sensing RARE MRI. J Magn Reson 2016; 270:187-197. [PMID: 27500742 DOI: 10.1016/j.jmr.2016.07.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/26/2016] [Accepted: 07/27/2016] [Indexed: 06/06/2023]
Abstract
Three-dimensional (3D) imaging of the fluid distributions within the rock is essential to enable the unambiguous interpretation of core flooding data. Magnetic resonance imaging (MRI) has been widely used to image fluid saturation in rock cores; however, conventional acquisition strategies are typically too slow to capture the dynamic nature of the displacement processes that are of interest. Using Compressed Sensing (CS), it is possible to reconstruct a near-perfect image from significantly fewer measurements than was previously thought necessary, and this can result in a significant reduction in the image acquisition times. In the present study, a method using the Rapid Acquisition with Relaxation Enhancement (RARE) pulse sequence with CS to provide 3D images of the fluid saturation in rock core samples during laboratory core floods is demonstrated. An objective method using image quality metrics for the determination of the most suitable regularisation functional to be used in the CS reconstructions is reported. It is shown that for the present application, Total Variation outperforms the Haar and Daubechies3 wavelet families in terms of the agreement of their respective CS reconstructions with a fully-sampled reference image. Using the CS-RARE approach, 3D images of the fluid saturation in the rock core have been acquired in 16min. The CS-RARE technique has been applied to image the residual water saturation in the rock during a water-water displacement core flood. With a flow rate corresponding to an interstitial velocity of vi=1.89±0.03ftday(-1), 0.1 pore volumes were injected over the course of each image acquisition, a four-fold reduction when compared to a fully-sampled RARE acquisition. Finally, the 3D CS-RARE technique has been used to image the drainage of dodecane into the water-saturated rock in which the dynamics of the coalescence of discrete clusters of the non-wetting phase are clearly observed. The enhancement in the temporal resolution that has been achieved using the CS-RARE approach enables dynamic transport processes pertinent to laboratory core floods to be investigated in 3D on a time-scale and with a spatial resolution that, until now, has not been possible.
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Affiliation(s)
- N P Ramskill
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK.
| | - I Bush
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - A J Sederman
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - M D Mantle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
| | - M Benning
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
| | - B C Anger
- Shell Technology Centre, 3333 Highway 6 S, Houston, TX, USA
| | - M Appel
- Shell Technology Centre, 3333 Highway 6 S, Houston, TX, USA
| | - L F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA, UK
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Ondrejkovic P, Kempa M, Kulda J, Frick B, Appel M, Combet J, Dec J, Lukasiewicz T, Hlinka J. Dynamics of nanoscale polarization fluctuations in a uniaxial relaxor. Phys Rev Lett 2014; 113:167601. [PMID: 25361280 DOI: 10.1103/physrevlett.113.167601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Indexed: 06/04/2023]
Abstract
We have studied neutron diffuse scattering in a Sr(0.61)Ba(0.39)Nb(2)O(6) single crystal by neutron backscattering at sub-μeV energy resolution. We can identify two response components with transverse polarization: an elastic (resolution limited) central peak, which monotonically increases with decreasing temperature, and a quasielastic central peak, having a maximum intensity around the ferroelectric phase transition close to 350 K. In contrast to previous neutron experiments on this and other relaxor materials, we were able to observe a temperature dependence of the characteristic frequency of these fluctuations, obeying the same Vogel-Fulcher law as the dynamic part of the dielectric permittivity of this material. In this way our findings provide a first direct link between the Vogel-Fulcher-type frequency dependence of dielectric permittivity and dynamic nanoscale lattice modulations with a transverse correlation length of about 5-10 unit cells.
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Affiliation(s)
- P Ondrejkovic
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
| | - M Kempa
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
| | - J Kulda
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - B Frick
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - M Appel
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J Combet
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - J Dec
- Institute of Materials Science, University of Silesia, Bankowa 12, PL-40-007 Katowice, Poland
| | - T Lukasiewicz
- Institute of Electronic Materials Technology, 133 Wolczynska Street, 01-919 Warsaw, Poland
| | - J Hlinka
- Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 18221 Praha 8, Czech Republic
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Andreis E, Küllmer K, Appel M. Application of the reference method isotope dilution gas chromatography mass spectrometry (ID/GC/MS) to establish metrological traceability for calibration and control of blood glucose test systems. J Diabetes Sci Technol 2014; 8:508-15. [PMID: 24876614 PMCID: PMC4455442 DOI: 10.1177/1932296814523886] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Self-monitoring of blood glucose (BG) by means of handheld BG systems is a cornerstone in diabetes therapy. The aim of this article is to describe a procedure with proven traceability for calibration and evaluation of BG systems to guarantee reliable BG measurements. Isotope dilution gas chromatography mass spectrometry (ID/GC/MS) is a method that fulfills all requirements to be used in a higher-order reference measurement procedure. However, this method is not applicable for routine measurements because of the time-consuming sample preparation. A hexokinase method with perchloric acid (PCA) sample pretreatment is used in a measurement procedure for such purposes. This method is directly linked to the ID/GC/MS method by calibration with a glucose solution that has an ID/GC/MS-determined target value. BG systems are calibrated with whole blood samples. The glucose levels in such samples are analyzed by this ID/GC/MS-linked hexokinase method to establish traceability to higher-order reference material. For method comparison, the glucose concentrations in 577 whole blood samples were measured using the PCA-hexokinase method and the ID/GC/MS method; this resulted in a mean deviation of 0.1%. The mean deviation between BG levels measured in >500 valid whole blood samples with BG systems and the ID/GC/MS was 1.1%. BG systems allow a reliable glucose measurement if a true reference measurement procedure, with a noninterrupted traceability chain using ID/GC/MS linked hexokinase method for calibration of BG systems, is implemented. Systems should be calibrated by means of a traceable and defined measurement procedure to avoid bias.
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Weslinck N, De Jonckheere J, Storme L, Logier R, Appel M, Thomas D, Rakza T. [Impact of the instrumental vaginal delivery on pain perception at two months]. Arch Pediatr 2014; 21:614-9. [PMID: 24768067 DOI: 10.1016/j.arcped.2014.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 01/01/2014] [Accepted: 03/10/2014] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Although instrumental vaginal delivery reduces the risk of neonatal mortality, it increases the risk of specific morbidity including prolonged neonatal discomfort. Previous studies suggest that neonatal exposure to acute pain could have long-term effects on the pain response later in life. The aim of the study was to investigate whether instrumental vaginal delivery may alter the response to a noxious stimulus at the age of two months. METHOD Newborn infants were enrolled in this prospective observational study after parental consent. A group of children born by instrumental vaginal delivery (group 2) were compared to matched controls born by vaginal delivery (group 1). Pain was assessed in each newborn infant between two and four hours after birth using the scale of pain and discomfort of the newborn baby (EDIN). These children were reassessed for pain response to immunizations (Infanrix(®) and Prevenar(®)) at two months of age using the DAN scale. RESULTS Thirteen children were enrolled in this study, six in group 1 and seven in group 2. Gestational age, birth weight, Apgar score, and umbilical arterial blood were similar in both groups. The EDIN measured between H2 and H4 was significantly higher in group 2 (median, 4 [IQ, 3] versus 0 [3.25], P<0.05). While the DAN score before and during immunization was similar in the two groups, it was statistically higher in group 2 than in group 1 (4 [3] versus 2 [2.25], P<0.01) within the15 min following the injections. CONCLUSION These results indicate that birth by instrumental vaginal delivery causes discomfort after birth and increases the pain response to immunization at the age of two months. This study supports the hypothesis that instrumental vaginal delivery may alter pain perception later in life.
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Affiliation(s)
- N Weslinck
- Pôle femme, mère et nouveau-né, hôpital Jeanne-de-Flandre, CHRU de Lille, 1, avenue Eugène-Avinée, 59038 Lille cedex, France
| | - J De Jonckheere
- Inserm CIC-IT 807, institut Hippocrate, CHRU de Lille, 59038 Lille, France; UPRES-EA4489, environnement périnatal et croissance, faculté de médecine, université Lille I et Lille II, 1, place de Verdun, 59000 Lille, France
| | - L Storme
- Pôle femme, mère et nouveau-né, hôpital Jeanne-de-Flandre, CHRU de Lille, 1, avenue Eugène-Avinée, 59038 Lille cedex, France; UPRES-EA4489, environnement périnatal et croissance, faculté de médecine, université Lille I et Lille II, 1, place de Verdun, 59000 Lille, France
| | - R Logier
- Inserm CIC-IT 807, institut Hippocrate, CHRU de Lille, 59038 Lille, France
| | - M Appel
- Pôle femme, mère et nouveau-né, hôpital Jeanne-de-Flandre, CHRU de Lille, 1, avenue Eugène-Avinée, 59038 Lille cedex, France
| | - D Thomas
- Pôle femme, mère et nouveau-né, hôpital Jeanne-de-Flandre, CHRU de Lille, 1, avenue Eugène-Avinée, 59038 Lille cedex, France
| | - T Rakza
- Pôle femme, mère et nouveau-né, hôpital Jeanne-de-Flandre, CHRU de Lille, 1, avenue Eugène-Avinée, 59038 Lille cedex, France; UPRES-EA4489, environnement périnatal et croissance, faculté de médecine, université Lille I et Lille II, 1, place de Verdun, 59000 Lille, France.
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Hillesheim I, Appel M, Dos Reis R, Rolim K, Souza A, Klimann L, Monego H. Cervical cancer post-treatment follow-up: Critical analysis. Gynecol Oncol 2013. [DOI: 10.1016/j.ygyno.2013.04.169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Appel M, Visser C, Woutersen R. Cell proliferation and apoptosis in the exocrine pancreas of azaserine-treated rats and N-nitrosobis(2-oxopropyl)amine-treated hamsters. Int J Oncol 2012; 8:1171-8. [PMID: 21544479 DOI: 10.3892/ijo.8.6.1171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Altered cell proliferation is an important characteristic of neoplastic development, hence the quantitation of cell growth in normal and (pre)neoplastic pancreatic tissue will provide useful information on the process (and modulation) of pancreatic tumour promotion in experimental animals. Cell proliferation was estimated by means of BrdU-incorporation in normal pancreatic tissue and in putative preneoplastic pancreatic tissue of azaserine-treated rats and of N-nitrosobis(2-oxopropyl)amine (BOP)-treated hamsters at 2, 6, 12, 26 and 52 weeks post-treatment. Furthermore, the effects of diets high in vegetable oil or fish oil on the BrdU labeling index, the Ki-67 labeling index as well as the apoptotic labeling index were determined in azaserine-induced atypical acinar cell foci (AACF) in the pancreas of rats. In saline- and azaserine-treated rats, the BrdU labeling index (LI) in normal pancreatic acinar cells showed a similar time-related decrease. In azaserine-treated rats, the BrdU-LI in AACF was significantly higher than in normal acinar tissue. The BrdU, Ki-67 and apoptotic labeling indices in pancreatic AACF of rats fed diets high in vegetable oil versus fish oil were 24.8+/-1.7 vs 15.5+/-1.2 (BrdU; P<0.05), 9.9+/-0.8 vs 6.5+/-0.5 (Ki-67; P<0.001) and 1.31+/-0.12 vs 0.97+/-0.11 (apoptosis; P<0.05), respectively. In hamsters, up to 26 weeks after BOP-treatment the BrdU-LI in acinar cells was significantly higher than in saline-treated animals. In BOP-treated hamsters, ductal cells showed a significantly increased LI 2 weeks post-treatment, whereas the LI in centroacinar cells had significantly increased 2 and 26 weeks post-treatment. In hamster pancreas the LI was significantly higher in tubular ductal complexes than in cystic ductal complexes and was highest in borderline lesions. It is concluded that (i) determination of BrdU-LI provides a reliable parameter to discriminate between putative preneoplastic lesions with a high or low growth potential, hence with a high or low potential to develop into ultimate carcinomas, (ii) BOP causes increased DNA synthesis in normal acinar cells, leading to increased risk of additional DNA damage, implicating the acinar cell to be putatively involved in the development of ductular adenocarcinomas in the hamster pancreas and (iii) quantitation of cell proliferation and apoptosis may be useful to determine the enhancing or inhibitory effects of life-style factors on pancreatic carcinogenesis.
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Affiliation(s)
- M Appel
- TNO,NUTR & FOOD RES INST,DIV TOXICOL,DEPT GEN TOXICOL,3700 AJ ZEIST,NETHERLANDS
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Matos J, Appel M, Korngold R, Friedman T. TCR Transduction Approach to Expand Severe Graft-Versus-Host Disease Inducing CD4 Specific T Cells. Biol Blood Marrow Transplant 2012. [DOI: 10.1016/j.bbmt.2011.12.434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Osán TM, Ollé JM, Carpinella M, Cerioni LMC, Pusiol DJ, Appel M, Freeman J, Espejo I. Fast measurements of average flow velocity by Low-Field ¹H NMR. J Magn Reson 2011; 209:116-122. [PMID: 21316994 DOI: 10.1016/j.jmr.2010.07.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/25/2010] [Accepted: 07/15/2010] [Indexed: 05/30/2023]
Abstract
In this paper, we describe a method for measuring the average flow velocity of a sample by means of Nuclear Magnetic Resonance. This method is based on the Carr-Purcell-Meiboom-Gill (CPMG) sequence and does not require the application of any additional static or pulsed magnetic field gradients to the background magnetic field. The technique is based on analyzing the early-time behavior of the echo amplitudes of the CPMG sequence. Measurements of average flow velocity of water are presented. The experimental results show a linear relationship between the slope/y-intercept ratio of a linear fit of the first echoes in the CPMG sequence, and the average flow velocity of the flowing fluid. The proposed method can be implemented in low-cost Low-Field NMR spectrometers allowing a continuous monitoring of the average velocity of a fluid in almost real-time, even if the flow velocity changes rapidly.
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Affiliation(s)
- T M Osán
- Spinlock S.R.L., Córdoba, X5020DVD, Argentina.
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Ergezen E, Appel M, Shah P, Kresh JY, Lec RM, Wootton DM. Real-time monitoring of adhesion and aggregation of platelets using thickness shear mode (TSM) sensor. Biosens Bioelectron 2007; 23:575-82. [PMID: 17913487 DOI: 10.1016/j.bios.2007.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2007] [Revised: 05/23/2007] [Accepted: 05/25/2007] [Indexed: 10/23/2022]
Abstract
Hemostasis is required to maintain vascular system integrity, but thrombosis, formation of a clot in a blood vessel, is one of the largest causes of morbidity and mortality in the industrialized world. Novel clinical and research tools for characterizing the hemostatic system are of continued interest, and the object of this research is to test the hypothesis that clinically relevant platelet function can be monitored using an electromechanical sensor. A piezoelectric thickness shear mode (TSM) biosensor coated with collagen-I fibers to promote platelet activation and adhesion was developed and tested for sensitivity to detect these primary events. Magnitude and frequency response of the sensor were monitored under static conditions at 37 degrees C, using platelet-rich plasma (PRP), and PRP with adenosine diphosphate (ADP), a clinical aggregation inhibitor (abciximab), or a collagen binding inhibitor. Sensors loaded with PRP exhibited a 3-stage response; no significant change in response for the first 20 min (Stage-1), followed by a larger drop in response (Stage-2) and subsequently, response gradually increased (Stage-3). Exogenous ADP stimulated an immediate Stage-2 response, while abciximab delayed and reduced the magnitude change of Stage-2. In the presence of collagen inhibitor, Stage-2 response was similar to that of control but was delayed by an additional 20 min. The obtained results, supported by epifluorescence and complementary SEM studies, demonstrated the selective sensitivity of TSM electromechanical biosensors to monitor platelet function and inhibition, particularly aggregation.
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Affiliation(s)
- E Ergezen
- School of Biomedical Engineering, Science and Health Systems, Drexel University, United States
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Kim HR, Gil S, Andrieux K, Nicolas V, Appel M, Chacun H, Desmaële D, Taran F, Georgin D, Couvreur P. Low-density lipoprotein receptor-mediated endocytosis of PEGylated nanoparticles in rat brain endothelial cells. Cell Mol Life Sci 2007; 64:356-64. [PMID: 17256088 DOI: 10.1007/s00018-007-6390-x] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Poly(methoxypolyethyleneglycol cyanoacrylate-co-hexadecylcyanoacrylate) (PEG-PHDCA) nanoparticles have demonstrated their capacity to diffuse through the blood-brain barrier after intravenous administration. However, the mechanism of transport of these nanoparticles into brain has not yet been clearly elucidated. The development of a model of rat brain endothelial cells (RBEC) in culture has allowed investigations into this mechanism. A study of the intracellular trafficking of nanoparticles by cell fractionation and confocal microscopy showed that nanoparticles are internalized by the endocytic pathway. Inhibition of the caveolae-mediated pathway by preincubation with filipin and nystatin did not modify the cellular uptake of the nanoparticles. In contrast, chlorpromazine and NaN(3) pretreatment, which interferes with clathrin and energy-dependent endocytosis, caused a significant decrease of nanoparticle internalization. Furthermore, cellular uptake experiments with nanoparticles preincubated with apolipoprotein E and blocking of low-density lipoprotein receptors (LDLR) clearly suggested that the LDLR-mediated pathway was involved in the endocytosis of PEGPHDCA nanoparticles by RBEC.
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Affiliation(s)
- H Ryoung Kim
- Laboratory of Biopharmacy and Pharmaceutical Technology, Faculty of Pharmacy, UMR 8612, IFR 141, CNRS, University of Paris-Sud 11, 5, rue J. B. Clément, 92296 Châtenay-Malabry, France
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Abstract
In September 2001, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) founded the Collaborative Islet Transplant Registry (CITR). Each year, CITR produces a complete set of analyses available to the public. In its second year, CITR represents the efforts of 19 North American islet transplant programs reporting information on 138 islet transplant recipients (1999-2004), 256 processed pancreata that led to infusion, and 266 infusion procedures. This analysis focuses on recipients of islet-alone procedures. Median age of the recipient is 41.6 years (range, 23.1-64.4 years), duration of diabetes is 29 years (range, 4-50 years), and over 66% are female. Median weight of the recipient is 65 kg (range, 47-97 kg) and median body mass index (BMI) is 23.1 kg/m(2) (range, 18.8-31.6). Examining outcomes at 6 months following the recipient's last infusion, 67.0% are insulin independent, and at 12 months this percentage decreases to 58.0%. There is a striking decrease in the occurrence of severe hypoglycemic events subsequent to the first infusion. Over 82% of all recipients experience one or more severe hypoglycemic events in the year prior to their first infusion. However, only two recipients (2%) experience one or more severe hypoglycemic events between 30 days and 12 months postinfusion, but both of these recipients were on insulin replacement therapy and one had experienced a complete islet graft failure. The information provided in this analysis and subsequent analyses of CITR provides current and comprehensive information on outcome measures in islet transplantation.
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Affiliation(s)
- N Close
- EMMES Corp, Rockville, MD, USA.
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Raunser S, Appel M, Ganea C, Geldmacher-Kaufer U, Fendler K, Kühlbrandt W. Structure and function of prokaryotic glutamate transporters from Escherichia coli and Pyrococcus horikoshii. Biochemistry 2006; 45:12796-805. [PMID: 17042498 DOI: 10.1021/bi061008+] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The glutamate transporters GltP(Ec) from Escherichia coli and GltP(Ph) from Pyrococcus horikoshii were overexpressed in E. coli and purified to homogeneity with a yield of 1-2 mg/L of culture. Single-particle analysis and electron microscopy indicate that GltP(Ph) is a trimer in detergent solution. Electron microscopy of negatively stained GltP(Ph) two-dimensional crystals shows that the transporter is a trimer also in the membrane. Gel filtration of GltP(Ec) indicates a reversible equilibrium of two oligomeric states in detergent solution that we identified as a trimer and hexamer by blue-native gel electrophoresis and cross-linking. The purified transporters were fully active upon reconstitution into liposomes, as demonstrated by the uptake of radioactively labeled L-aspartate or L-glutamate. L-aspartate/L-glutamate transport of GltP(Ec) involves the cotransport of protons and depends only on pH, whereas GltP(Ph) catalyzes L-glutamate transport with a cotransport of H+ or Na+. L-glutamate induces a fast transient current in GltP(Ph) proteoliposomes coupled to a solid supported membrane (SSM). We show that the electric signal depends on the concentration of Na+ or H+ outside the proteoliposomes and that GltP(Ph) does not require K+ inside the proteoliposomes. In addition, the electrical currents are inhibited by TBOA and HIP-B. The half-saturation concentration for activation of GltP(Ph) glutamate transport (K0.5(glut)) is 194 microM.
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Affiliation(s)
- Stefan Raunser
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
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du Plessis L, Hendry DA, Dorrington RA, Hanzlik TN, Johnson JE, Appel M. Revised RNA2 sequence of the tetravirus, Nudaurelia capensis ω virus (NωV). Arch Virol 2005; 150:2397-402. [PMID: 16012786 DOI: 10.1007/s00705-005-0575-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Accepted: 05/16/2005] [Indexed: 10/25/2022]
Affiliation(s)
- L du Plessis
- Shimoda Biotech (Pty) Ltd., Greenacres, Port Elizabeth, South Africa
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Daoud-Mahammed S, Couvreur P, Amiel C, Besnard M, Appel M, Gref R. Original tamoxifen-loaded gels containing cyclodextrins: in situ self-assembling systems for cancer treatment. J Drug Deliv Sci Technol 2004. [DOI: 10.1016/s1773-2247(04)50005-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Larabi M, Pages N, Pons F, Appel M, Gulik A, Schlatter J, Bouvet S, Barratt G. Study of the toxicity of a new lipid complex formulation of amphotericin B. J Antimicrob Chemother 2003; 53:81-8. [PMID: 14657087 DOI: 10.1093/jac/dkh025] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The aim of this study was to evaluate the toxicity of a new lipid complex formulation of amphotericin B (LC-AmB) produced by a simple process. METHODS Toxicity was evaluated after daily administration for 21 consecutive days in female CD1 mice. Doses of LC-AmB up to 20 mg/kg were used, and compared with Fungizone at 0.5 mg/kg and Abelcet at 10 mg/kg. Acute toxicity after a single bolus injection was also determined, as well as the haemolytic activity and toxicity to mouse macrophages in vitro. RESULTS LC-AmB reduced both the haemolytic activity of amphotericin B and its toxicity towards mouse peritoneal macrophages. Its acute toxicity (LD50 > 200 mg/kg in CD1 mice) was similar to that in the literature for the least toxic lipid formulations of amphotericin B. The relative liver weight increased slightly in mice treated daily with a dose of 20 mg/kg LC-AmB, as did the kidney weight in this group and the group treated with Fungizone. There was also a dose-dependent decrease in the haematocrit with all formulations. All treatments caused significant increases in transaminase levels. Total hepatic CYP 450 was slightly but not significantly increased in the groups treated with 20 mg/kg LC-AmB, Abelcet and Fungizone. However, expression of some isoforms of CYP 450 was reduced, the most marked being the hepatic CYP 3A1 after treatment with 20 mg/kg LC-AmB, Abelcet and Fungizone. The effects on hepatic function are probably related to accumulation in organs rich in phagocytic cells. CONCLUSION LC-AmB did not induce any new toxicity compared with Abelcet and Fungizone.
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Affiliation(s)
- M Larabi
- Laboratoire de Physico-chimie, Pharmacotechnie, Biopharmacie, UMR CNRS 8612, France
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23
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Espuelas MS, Legrand P, Campanero MA, Appel M, Chéron M, Gamazo C, Barratt G, Irache JM. Polymeric carriers for amphotericin B: in vitro activity, toxicity and therapeutic efficacy against systemic candidiasis in neutropenic mice. J Antimicrob Chemother 2003; 52:419-27. [PMID: 12888593 DOI: 10.1093/jac/dkg351] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To study the toxicity and activity of two new amphotericin B formulations: poly(epsilon-caprolactone) nanospheres coated with poloxamer 188 (AmB-NP) and mixed micelles with the same surfactant (AmB-MM). MATERIALS AND METHODS The toxicity of these formulations was evaluated in erythrocytes, J774.2 macrophages and LLCPK1 renal cells, as well as in mice. Activity was determined in clinical isolates and in neutropenic mice. Mice were made neutropenic with 5-fluorouracil, infected with Candida albicans and treated with the antifungal formulations for three consecutive days. AmB association in cells and accumulation in kidneys and liver of animals was quantified by HPLC. RESULTS Both formulations decreased between 8- and 10-fold the MIC of the polyene against clinical isolates of C. albicans. However, their activity was lower than or equal to that of AmB-deoxycholate when it was assessed against C. albicans-infected macrophages. When given as a single intravenous dose in mice, AmB-MM and AmB-NP had an LD50 of 9.8 and 18.6 mg/kg, respectively, compared with 4 mg/kg for AmB-deoxycholate. Comparison of residual infection burdens in the liver and kidneys showed that AmB-deoxycholate (0.5 mg/kg) was more effective and faster in eradicating yeast cells than polymeric formulations. This fact can be related to a lower AmB accumulation inside macrophages and in liver and kidneys (about 1.5 mg drug/g tissue) of mice, compared with those detected for AmB-deoxycholate (4 mg drug/g). Overall, the efficacy of these formulations at 2 mg/kg was equal to that of AmB-deoxycholate at 0.5 mg/kg. CONCLUSIONS AmB-MM and AmB-NP decreased the in vivo antifungal activity of AmB, and higher concentrations were therefore necessary to obtain a similar therapeutic effect. However, these higher concentrations were achievable owing to the reduced toxicity of these formulations.
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Affiliation(s)
- M S Espuelas
- Centro Galénico, Facultad de Farmacia, Universidad de Navarra, 31080 Pamplona, Spain
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Waegell W, Babineau M, Hart M, Dixon K, McRae B, Wallace C, Leach M, Ratnofsky S, Belanger A, Hirst G, Rossini A, Appel M, Mordes J, Greiner D, Banerjee S. A420983, a novel, small molecule inhibitor of LCK prevents allograft rejection. Transplant Proc 2002; 34:1411-7. [PMID: 12176420 DOI: 10.1016/s0041-1345(02)02909-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- W Waegell
- Abbott Bioresearch Center, 100 Research Drive, Worcester, MA 01605, USA
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Appel M, Fleischer G, Kaerger J, Dieng AC, Riess G. Investigation of the Restricted Diffusion in Spherical Cavities of Polymers by Pulsed Field Gradient Nuclear Magnetic Resonance. Macromolecules 2002. [DOI: 10.1021/ma00111a030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fleischer G, Appel M. Chain Length and Temperature Dependence of the Self-Diffusion of Polyisoprene and Polybutadiene in the Melt. Macromolecules 2002. [DOI: 10.1021/ma00125a036] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Appel M, Fleischer G. Investigation of the chain length dependence of self-diffusion of poly(dimethylsiloxane) and poly(ethylene oxide) in the melt with pulsed field gradient NMR. Macromolecules 2002. [DOI: 10.1021/ma00072a033] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Whitmarsh AJ, Kuan CY, Kennedy NJ, Kelkar N, Haydar TF, Mordes JP, Appel M, Rossini AA, Jones SN, Flavell RA, Rakic P, Davis RJ. Requirement of the JIP1 scaffold protein for stress-induced JNK activation. Genes Dev 2001; 15:2421-32. [PMID: 11562351 PMCID: PMC312784 DOI: 10.1101/gad.922801] [Citation(s) in RCA: 186] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The c-Jun N-terminal kinase (JNK) signal transduction pathway is activated in response to the exposure of cells to environmental stress. Components of the JNK signaling pathway interact with the JIP1 scaffold protein. JIP1 is located in the neurites of primary hippocampal neurons. However, in response to stress, JIP1 accumulates in the soma together with activated JNK and phosphorylated c-Jun. Disruption of the Jip1 gene in mice by homologous recombination prevented JNK activation caused by exposure to excitotoxic stress and anoxic stress in vivo and in vitro. These data show that the JIP1 scaffold protein is a critical component of a MAP-kinase signal transduction pathway.
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Affiliation(s)
- A J Whitmarsh
- Howard Hughes Medical Institute and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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Appel M, Freeman JJ, Gardner JS, Hirasaki GH, Zhang QG, Shafer JL. Interpretation of restricted diffusion in sandstones with internal field gradients. Magn Reson Imaging 2001; 19:535-7. [PMID: 11445350 DOI: 10.1016/s0730-725x(01)00287-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We report on experiments to characterize internal magnetic field gradients that are caused by magnetic susceptibility differences between the solid phase and the fluids filling the pore space. Our measurements focus on low-field relaxometry of brine and oil in sandstones from various reservoirs around the world. Our results show the need to understand the dependence of internal field gradients on diffusion length, pore size- and fluid distribution in order to predict the impact of internal gradients on the interpretation of NMR experiments.
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Affiliation(s)
- M Appel
- Shell International Exploration & Production, Inc., 3737 Bellaire Blvd, Houston, TX, USA.
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Brigger I, Chaminade P, Marsaud V, Appel M, Besnard M, Gurny R, Renoir M, Couvreur P. Tamoxifen encapsulation within polyethylene glycol-coated nanospheres. A new antiestrogen formulation. Int J Pharm 2001; 214:37-42. [PMID: 11282234 DOI: 10.1016/s0378-5173(00)00628-1] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
When dealing with solid tumors in vivo, pegylated long-circulating carrier systems show, after intravenous administration, an attractive extravasation profile with an enhanced localization in the tumoral interstitium. These systems could be of help for the delivery of cancer fighting drugs, such as Tamoxifen, a well known antiestrogen used in breast cancer therapy that possesses an extended biodistribution in vivo. This work aimed at encapsulating Tamoxifen in long-circulating poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) 1:4 nanospheres. Tamoxifen-loaded poly(MePEGcyanoacrylate-co-hexadecylcyanoacrylate) nanospheres were successfully synthesized and characterized in terms of hydrophilicity/hydrophobicity by a model made up from near infrared spectra using principal component analysis. Zeta potential, drug loading, encapsulation efficiency, as well as biological effect, in vitro release and nanospheres integrity were also investigated. Even though near infrared spectroscopy could not detect Tamoxifen, it revealed that Pluronic F68 was associated with the pegylated nanospheres. HPLC measurements demonstrated that Tamoxifen was encapsulated in the pegylated nanospheres following a partition equilibrium between the polymeric and the aqueous phases. The Tamoxifen encapsulated in the nanospheres still showed a transcription inhibitory activity in ex vivo experiments. However, zeta potential and in vitro release suggested that Tamoxifen was essentially localized at the nanoparticles surface, resulting in an important and immediate drug release.
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Affiliation(s)
- I Brigger
- Faculty of Pharmacy, UMR 8612, University of Paris-Sud XI, 5 Rue J.B. Clement, 92296 Châtenay-Malabry, France
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Larabi M, Legrand P, Appel M, Gil S, Lepoivre M, Devissaguet J, Puisieux F, Barratt G. Reduction of no synthase expression and tumor necrosis factor alpha production in macrophages by amphotericin B lipid carriers. Antimicrob Agents Chemother 2001; 45:553-62. [PMID: 11158754 PMCID: PMC90326 DOI: 10.1128/aac.45.2.553-562.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The present study compared the abilities of different lipid carriers of amphotericin B (AMB) to activate murine peritoneal macrophages, as assessed by their capacities to produce nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha). Although AMB alone did not induce NO production, synergy was observed with gamma interferon but not with lipopolysaccharide. This synergy could not be explained by the mobilization of the nuclear activation factor NF-kappaB by AMB. On the other hand, AMB induced TNF-alpha production without a costimulator and no synergy was observed. Anti-TNF-alpha antibodies did not influence NO production, and an inhibitor of NO synthase did not affect TNF-alpha production, indicating that the production of one of these effector molecules was independent of that of the other. The incorporation of AMB into lipid carriers reduced NO and TNF-alpha production with all formulations but more so with liposomes than with lipid complexes. NO production was correlated with the induction of NO synthase II, revealed by Western blotting. The extent of association of AMB with macrophages depended on the formulation, especially on the AMB/lipids ratio: the higher the ratio was, the greater the AMB association with macrophages. However, there was no clear correlation between AMB association with macrophages, whether internalized or bound to the membrane, and immunostimulating effects. These results may explain the reduced toxicities of lipid-based formulations of AMB.
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Affiliation(s)
- M Larabi
- Laboratoire de Physico-Chimie-Pharmacotechnie-Biopharmacie, UMR CNRS 8612, France
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Jaulin N, Appel M, Passirani C, Barratt G, Labarre D. Reduction of the uptake by a macrophagic cell line of nanoparticles bearing heparin or dextran covalently bound to poly(methyl methacrylate). J Drug Target 2000; 8:165-72. [PMID: 10938526 DOI: 10.3109/10611860008996862] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Amphiphilic and fluorescent covalently labelled core-shell nanoparticles based on poly(methyl methacrylate) (PMMA), were prepared by random copolymerisation of N-Vinyl carbazole (NVC) with MMA, initiated on polysaccharidic radicals, yielding diblock copolymers of either dextran-P(MMA-NVC) (Nanodex* particles), or heparin-P(MMA-NVC) (Nanohep* particles). Nanoparticles made from random copolymers of P(MMA-NVC) (PMMA*) were used as controls. The interactions between particles and a J774A1 murine macrophage-like cell line were quantified by direct measurement of the cell-associated fluorescence. The association with the cells occurred within 30 min. Nanodex* and Nanohep* showed considerably less association than the control PMMA* particles. Some of the particle uptake could be attributed to phagocytosis, but more than 50% of the cell-associated fluorescence persisted at low temperature or in the presence of cytochalasin B. The results suggest that both the adsorption and the internalisation processes can be inhibited by the presence of the polysaccharide chains. In conclusion, these results confirm that nanoparticles prepared with heparin or dextran chains on their surface, probably in a brush-like configuration, show "stealth" properties in vitro as had previously been observed in vivo. If this biomimetic approach can also be applied to biodegradable polymers, these systems would provide at least an alternative to PEG-modified particles as long-circulating drug carriers systems or imaging agents.
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Affiliation(s)
- N Jaulin
- Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, UMR CNRS 8612, Faculté de Pharmacie, Université Paris Sud-XI, 5 rue J. B. Clément, 92290 Châtenay-Malabry, France
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Chehab NH, Malikzay A, Appel M, Halazonetis TD. Chk2/hCds1 functions as a DNA damage checkpoint in G(1) by stabilizing p53. Genes Dev 2000; 14:278-88. [PMID: 10673500 PMCID: PMC316357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Chk2/hcds1, the human homolog of the Saccharomyces cerevisiae RAD53/SPK1 and Schizosaccharomyces pombe cds1 DNA damage checkpoint genes, encodes a protein kinase that is post-translationally modified after DNA damage. Like its yeast homologs, the Chk2/hCds1 protein phosphorylates Cdc25C in vitro, suggesting that it arrests cells in G(2) in response to DNA damage. We expressed Chk2/hCds1 in human cells and analyzed their cell cycle profile. Wild-type, but not catalytically inactive, Chk2/hCds1 led to G(1) arrest after DNA damage. The arrest was inhibited by cotransfection of a dominant-negative p53 mutant, indicating that Chk2/hCds1 acted upstream of p53. In vitro, Chk2/hCds1 phosphorylated p53 on Ser-20 and dissociated preformed complexes of p53 with Mdm2, a protein that targets p53 for degradation. In vivo, ectopic expression of wild-type Chk2/hCds1 led to increased p53 stabilization after DNA damage, whereas expression of a dominant-negative Chk2/hCds1 mutant abrogated both phosphorylation of p53 on Ser-20 and p53 stabilization. Thus, in response to DNA damage, Chk2/hCds1 stabilizes the p53 tumor suppressor protein leading to cell cycle arrest in G(1).
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Affiliation(s)
- N H Chehab
- Department of Molecular Genetics, The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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Barth E, Wollmeyer J, Fischer G, Weckmann T, Appel M, Schneider EM, Moldawer LL, Georgieff M, Weiss M. In contrast to CD64 expression, CD14 expression is persistently downregulated on polymorphonuclear cells (PMN) but not on monocytes of patients with septic shock. Crit Care 2000. [PMCID: PMC3332977 DOI: 10.1186/cc773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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36
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Mosqueira VC, Legrand P, Gref R, Heurtault B, Appel M, Barratt G. Interactions between a macrophage cell line (J774A1) and surface-modified poly (D,L-lactide) nanocapsules bearing poly(ethylene glycol). J Drug Target 1999; 7:65-78. [PMID: 10614816 DOI: 10.3109/10611869909085493] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The interactions of naked and surface-modified poly(D,L-lactic acid) (PLA) nanocapsules (NC), where polyethyleneglycol (PEG) was adsorbed or covalently attached, have been studied with a macrophage-like cell line. The fluorescent oil marker, DiD, was successfully encapsulated in NCs in order to follow their interactions with cells. The cell-associated fluorescence obtained with PEG-PLA NC was about 3- to 13-fold lower than that obtained with naked-PLA NC. The effects of PEG chain length, its content as a percentage of total polymer and NC concentration in the culture medium were evaluated. PEG-PLA NC showed dramatically reduced fluorescence association with cells during an 18 h incubation compared with naked-PLA NC, showing that covalent attachment of PEG is important for the persistence of low uptake. The best results in reducing cell-associated fluorescence were obtained with a surface-modified PEG-PLA NC bearing a chain with 20000 MW. Increasing the percentage of PEG produced a reduction in marker association for a given PEG chain length. Moreover, when the PEG-containing poloxamer was simply adsorbed, marker association was dependent on the extent of dilution and the type of serum in the culture medium. Serum proteins, especially immunoglobulins, increased cell-associated fluorescence for PEG-adsorbed NC, but had very little effect on PEG-PLA NC. Marker association was only partially inhibited in the presence of cytochalasin B. The mechanisms of cell-NC interaction depended on the characteristics of the NC surface in each formulation. When the NC was physically separated from cells no diffusion of fluorescent marker in aqueous medium occurred. Nevertheless, collision-mediated transfer of DiD from NC to J774 cells was a non-negligible route of marker transfer, mainly for naked NC. However, this collision-mediated transfer was reduced for the PEG-PLA NC probably due to the restricted contact between NC and cells afforded by PEG steric hindrance at the surface.
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Affiliation(s)
- V C Mosqueira
- Laboratoire de Physico-Chimie, Pharmacotechnie et Biopharmacie, UMR CNRS 8612, Université de Paris-Sud, Châtenay-Malabry, France
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Schmidt A, Kababya S, Appel M, Khatib S, Botoshansky M, Eichen Y. Measuring the Temperature Width of a First-Order Single Crystal to Single Crystal Phase Transition Using Solid-State NMR: Application to the Polymorphism of 2-(2,4-Dinitrobenzyl)-3-methylpyridine. J Am Chem Soc 1999. [DOI: 10.1021/ja991204m] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- A. Schmidt
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
| | - S. Kababya
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
| | - M. Appel
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
| | - S. Khatib
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
| | - M. Botoshansky
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
| | - Y. Eichen
- Contribution from the Department of Chemistry and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000 Israel
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Abstract
BACKGROUND Apheresis devices designed for the collection of mature blood elements are being used for the collection of peripheral blood progenitor cells (PBPCs). The collection of PBPCs differs from that of other cells in the rarity of the target cell and in the fact that donors may undergo several days of collection. A consequence of this process may be a depletion of blood cells such as platelets from the blood. The disposable set and operating software for an apheresis device (Spectra, COBE BCT) was modified by the manufacturer to automate the collection of PBPCs and reduce the collection of unwanted blood cells. STUDY DESIGN AND METHODS A study was initiated to compare the collection of PBPCs with the new device, the AutoPBSC (version [V]6.0 with AutoPBSC tubing set), and that with the MNC (mononuclear cell) procedure (V4.7 with white cell tubing set), for patients and healthy donors. RESULTS Patients whose blood was processed by either theV6.0 orV4.7 procedure achieved the target dose of 5 x 10(6) CD34+ cells per kg of patient weight in similar numbers of procedures, even though the calculated collection efficiency for CD34+ cells using the automated V6.0 procedure was significantly less than that with the V4.7 procedure for both allogeneic donors and patients donating PBPCs. The collection efficiency for platelets was lower with the V6.0 procedure, and components collected in this manner contained fewer platelets. Apheresis by the V6.0 procedure required 30 to 60 more minutes per procedure than apheresis by the V4.7 procedure. Review of engraftment kinetics after transplantation did not reveal any effect of the collection procedure on recipients of either allogeneic or autologous transplants. CONCLUSION The collection efficiencies of the V6.0 procedure for both CD34+ cells and mature blood cells are lower than those of the V4.7 procedure. The lower collection efficiency for platelets results in a smaller drop in peripheral blood platelet count after the procedure. The automated features of the V6.0 procedure may simplify PBPC collection, but this procedure requires a longer apheresis.
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Affiliation(s)
- S D Rowley
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
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Packer C, Altizer S, Appel M, Brown E, Martenson J, O'Brien SJ, Roelke‐Parker M, Hofmann‐Lehmann R, Lutz H. Viruses of the Serengeti: patterns of infection and mortality in African lions. J Anim Ecol 1999. [PMCID: PMC7197470 DOI: 10.1046/j.1365-2656.1999.00360.x] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
1. We present data on the temporal dynamics of six viruses that infect lions (Panthera leo) in the Serengeti National Park and Ngorongoro Crater, Tanzania. These populations have been studied continuously for the past 30 years, and previous research has documented their seroprevalence for feline herpesvirus, feline immunodeficiency virus (FIV), feline calicivirus, feline parvovirus, feline coronavirus and canine distemper virus (CDV). A seventh virus, feline leukaemia virus (FeLV), was absent from these animals. 2. Comprehensive analysis reveals that feline herpesvirus and FIV were consistently prevalent at high levels, indicating that they were endemic in the host populations. Feline calici‐, parvo‐ and coronavirus, and CDV repeatedly showed a pattern of seroprevalence that was indicative of discrete disease epidemics: a brief period of high exposure for each virus was followed by declining seroprevalence. 3. The timing of viral invasion suggests that different epidemic viruses are associated with different minimum threshold densities of susceptible hosts. Furthermore, the proportion of susceptibles that became infected during disease outbreaks was positively correlated with the number of susceptible hosts at the beginning of each outbreak. 4. Examination of the relationship between disease outbreaks and host fitness suggest that these viruses do not affect birth and death rates in lions, with the exception of the 1994 outbreak of canine distemper virus. Although the endemic viruses (FHV and FIV) were too prevalent to measure precise health effects, there was no evidence that FIV infection reduced host longevity.
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Affiliation(s)
- C. Packer
- Department of Ecology, Evolution and Behaviour, University of Minnesota, St. Paul, MN, USA
| | - S. Altizer
- Department of Ecology, Evolution and Behaviour, University of Minnesota, St. Paul, MN, USA
| | - M. Appel
- James Baker Institute of Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - E. Brown
- Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick, MD, USA; and
| | - J. Martenson
- Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick, MD, USA; and
| | - S. J. O'Brien
- Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick, MD, USA; and
| | - M. Roelke‐Parker
- Laboratory of Viral Carcinogenesis, National Cancer Institute, Frederick, MD, USA; and
| | - R. Hofmann‐Lehmann
- Clinical Laboratory, Department of Internal Veterinary Medicine, University of Zurich, Zurich, Switzerland
| | - H. Lutz
- Clinical Laboratory, Department of Internal Veterinary Medicine, University of Zurich, Zurich, Switzerland
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Soma CE, Dubernet C, Barratt G, Nemati F, Appel M, Benita S, Couvreur P. Ability of doxorubicin-loaded nanoparticles to overcome multidrug resistance of tumor cells after their capture by macrophages. Pharm Res 1999; 16:1710-6. [PMID: 10571276 DOI: 10.1023/a:1018902031370] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Investigation of the ability of doxorubicin-loaded nanoparticles (NP/Dox) to overcome multidrug resistance (MDR) when they have first been taken up by macrophages. METHODS The growth inhibition of P388 sensitive (P388) and resistant (P388/ADR) tumor cells was evaluated in a coculture system consisting of wells with two compartments. The tumor cells were seeded into the lower compartment, the macrophages were introduced into the upper part in which the drug preparations were also added. RESULTS Doxorubicin exerted lower cytotoxicity on tumor cells in coculture compared with direct contact. In P388/ADR, NP/Dox cytotoxicity was far higher than that of free doxorubicin (Dox). Three different formulations of cyclosporin A (either free (CyA), loaded to nanoparticles (NP/CyA) or in a combined formulation with doxorubicin (NP/Dox-CyA)), were added to modulate doxorubicin efficacy. The addition of cyclosporin A to Dox increased drug cytotoxicity. Both CyA added to NP/Dox and NP/Dox-CyA were able to bypass drug resistance. CONCLUSIONS Despite the barrier role of macrophages, NP/Dox remained far more cytotoxic than Dox against P388/ADR. Both NP/Dox + CyA and NP/Dox-CyA allowed to overcome MDR, but the last one should present greater advantage in vivo by confining both drugs in the same compartment, hence reducing the adverse effects.
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Affiliation(s)
- C E Soma
- Centre d'Etudes Pharmaceutiques, UMR CNRS 8612, Châtenay-Malabry, France
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Chabannon C, Blache JL, Sielleur I, Douville J, Faucher C, Gravis G, Arnoulet C, Oziel-Taieb S, Blaise D, Novakovitch G, Camerlo J, Chabbert I, Genre D, Appel M, Armstrong D, Maraninchi D, Viens P. Production of ex vivo expanded hematopoietic cells and progenitors in a closed bioreactor, starting with a small volume marrow collection: A feasibility study in patients with poor-risk breast cancer and receiving high-doses of cyclophosphamide. Int J Oncol 1999; 15:511-8. [PMID: 10427133 DOI: 10.3892/ijo.15.3.511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
We report a clinical pilot study conducted in 6 women with poor-prognosis breast cancer. The goal was to evaluate the feasibility and safety of producing hematopoietic progenitors and cells from a small marrow sample, for clinical use after high-dose cyclophosphamide. A small volume marrow collection was obtained, using local anesthesia and conscious sedation, before the first of two chemotherapy cycles. Cells were cryopreserved, and later thawed to inoculate two Aastrom Biosciences Inc Replicell bioreactors, on time to reinfuse ex vivo expanded cells after the second chemotherapy cycle. Patients recovered neutrophils and platelets at similar times after the first and second chemotherapy cycles, and showed comparable clinical events. This pilot study prepares future randomized trials, designed to evaluate clinical benefits associated with the use of ex vivo expanded cells in the setting of multicycle high-dose chemotherapy.
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Affiliation(s)
- C Chabannon
- Laboratoire de Biologie Cellulaire, Centre de Therapie Cellulaire, Institut Paoli-Calmettes, CRLCC Provence-Alpes-Cote d'Azur, 13273 Marseille cedex 9, France
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42
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Peracchia MT, Fattal E, Desmaële D, Besnard M, Noël JP, Gomis JM, Appel M, d'Angelo J, Couvreur P. Stealth PEGylated polycyanoacrylate nanoparticles for intravenous administration and splenic targeting. J Control Release 1999; 60:121-8. [PMID: 10370176 DOI: 10.1016/s0168-3659(99)00063-2] [Citation(s) in RCA: 314] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The aim of the present work was to investigate the biodistribution characteristics of PEG-coated polycyanoacrylate nanoparticles prepared by the nanoprecipitation/solvent diffusion method using the previously synthesized poly(MePEGcyanoacrylate-hexadecylcyanoacrylate) copolymer. It was observed that [14C]-radiolabeled PEGylated nanoparticles remained for a longer time in the blood circulation after intravenous administration to mice, compared to the non-PEGylated poly(hexadecylcyanoacrylate) (PHDCA) nanoparticles. Furthermore, hepatic accumulation was dramatically reduced, whereas a highly increased spleen uptake was shown. The PEGylation degree of the polymer seemed not to affect the in vivo behavior of the nanoparticles, whereas previously obtained in vitro data have shown a modification of plasma protein adsorption depending on the density of PEG at the surface of the particles. Moreover, the study of the in vitro cytotoxicity of the nanoparticles revealed that the PEGylation of the cyanoacrylate polymer reduced its toxicity. These results open up interesting perspectives for the targeting of drugs to other tissues than the liver.
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Affiliation(s)
- M T Peracchia
- Université Paris XI, Pharmacotechnie, UMR CNRS 8612 - 5, rue J.B. Clément, 92296, Châtenay-Malabry, France
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Rathgeber S, Willner L, Richter D, Brulet A, Farago B, Appel M, Fleischer G. Polymer dynamics in bimodal polyethylene melts: A study with neutron spin echo spectroscopy and pulsed field gradient nuclear magnetic resonance. J Chem Phys 1999. [DOI: 10.1063/1.478890] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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44
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Fleischer G, Kärger J, Rittig F, Hoerner P, Riess G, Schmutzler K, Appel M. Liquid polyethylene glycol dispersed in a poly(styrene)-b-poly(ethylene/butylene)-b-poly(styrene) elastomer: determination of morphology and molecular mobility by light and electron microscopy as well as nuclear magnetic resonance self-diffusion andT2 measurements. POLYM ADVAN TECHNOL 1998. [DOI: 10.1002/(sici)1099-1581(1998100)9:10/11<700::aid-pat831>3.0.co;2-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Chabannon C, Blache JL, Faucher C, Gravis G, Douville J, Sielleur I, Tonnaire G, Novakovitch G, Appel M, Fish R, Bertucci F, Oziel-Taieb S, Stoppa AM, Biaise D, Chabbert I, Moatti JP, Muller T, Ogier W, Armstrong D, Maraninchi D, Viens P. O3-3 Production ex vivo et réinjection de progéniteurs hématopoïétiques autologues: une étude clinique pilote chez six patientes atteintes d'un cancer du sein. Transfus Clin Biol 1998. [DOI: 10.1016/s1246-7820(98)80034-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Seyler I, Appel M, Devissaguet JP, Legrand P, Barratt G. Modulation of nitric oxide production in RAW 264.7 cells by transforming growth factor-beta and interleukin-10: differential effects on free and encapsulated immunomodulator. J Leukoc Biol 1997; 62:374-80. [PMID: 9307077 DOI: 10.1002/jlb.62.3.374] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The mouse macrophage cell line RAW 264.7 can be stimulated to produce nitric oxide (NO) by muramyltripeptide cholesterol included within biodegradable poly(D,L-lactide) nanocapsules (NC MTPChol). The aim of this work was to determine whether one or both of the cytokines transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) could be responsible for feedback control seen at high concentrations. Activated RAW 264.7 cells produced TGFbeta1. When exogenous TGF-beta1 was added during stimulation, a dose-dependent inhibition of NO production was observed when NC MTP-Chol was used, whereas activation by the soluble muramyl dipeptide (MDP) was not affected. Furthermore, addition of a blocking antibody to TGF-beta arrested the fall in NO production seen at high concentrations of NC MTP-Chol. Addition of IL-10 during RAW 264.7 cell activation also reduced NO production; however, in this case, both NC MTP-Chol and MDP were equally affected. The presence of anti-IL-10 antibody during activation significantly increased NO production.
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Affiliation(s)
- I Seyler
- URA CNRS 1218, Centre d'Etudes Pharmaceutiques, Université, Paris-Sud, Châtenay-Malabry, France
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Appel M, Grenander U. Elements of Pattern Theory. J Am Stat Assoc 1997. [DOI: 10.2307/2965592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Appel M, Fleischer G, Kärger J, Chang I, Fujara F, Schönhals A. Transient entanglement behaviour in a poly(propylene glycole) melt: A field gradient NMR self-diffusion study. Colloid Polym Sci 1997. [DOI: 10.1007/s003960050070] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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de Verdière AC, Dubernet C, Némati F, Soma E, Appel M, Ferté J, Bernard S, Puisieux F, Couvreur P. Reversion of multidrug resistance with polyalkylcyanoacrylate nanoparticles: towards a mechanism of action. Br J Cancer 1997; 76:198-205. [PMID: 9231919 PMCID: PMC2223924 DOI: 10.1038/bjc.1997.362] [Citation(s) in RCA: 129] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Polyalkylcyanoacrylate (PACA) nanoparticles loaded with doxorubicin allowed multidrug resistance to be overcome in vitro. However, increased cytotoxicity is not always correlated with an increased level of intracellular drug. Although we have previously shown that PACA nanoparticles are not endocytosed by tumour cells, we report here that a direct interaction between nanoparticles and cells is a necessary requirement for overcoming resistance. In addition, the results showed that the degradation products of PACA (mainly polycyanoacrylic acid) in the presence of doxorubicin are able to increase both accumulation and cytotoxicity, thus suggesting the formation of a doxorubicin-polycyanoacrylic acid ion pair. It is therefore concluded that resistance is overcome as a result of both the adsorption of nanoparticles to the cell surface and increased doxorubicin diffusion by the accumulation of an ion pair at the plasma membrane.
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Affiliation(s)
- A C de Verdière
- Centre d'Etudes Pharmaceutiques, URA CNRS 1218, Châtenay-Malabry
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50
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Wetzel R, Appel M, Hess G, Schwarzkopf S, Puhl W. [Sesamoid bone complex and hallux valgus deformity. A retrospective analysis of 82 Mitchell osteotomies]. Z Orthop Ihre Grenzgeb 1996; 134:524-32. [PMID: 9027123 DOI: 10.1055/s-2008-1039919] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of the operative treatment of the hallux valgus deformity is to correct the medial luxation of the first metatarsal head out of the sesamoid complex, the restoration of a congruent joint, the patient after treatment should be painfree. 82 patients were available for an independent clinical and radiological review. The median follow up was 32 months. The evaluation of the results are based on objective and subjective assessment of the patients as well as on radiographic criteria, such as hallux valgus angle, intermetatarsal angle, shortening of the first metatarsal bone, subluxation, lateral positioning of the osteotomized MT I-head and position of the sesamoid complex. Depending on the degree of "lateralisation" of the sesamoid complex seven groups were defined: 0/0, 1/0, 1/1, 2/1, 2/2. 2/3, 3/3 following Appel. Following objective criteria 61% of the patients were evaluated excellent or good, following subjective criteria 77% were evaluated excellent or good. Isolated parallel shifting seems to be sufficient in mild forms of hallux valgus (sesamoid complex group 2/2 or less), while the severe subluxation in the metatarsophalangeal joint (sesamoid complex group 2/3, 3/3) requires an additional lateral wedge osteotomy.
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Affiliation(s)
- R Wetzel
- Orthopädische Abteilung des Rehabilitationskrankenhauses Ulm
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