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Freire M, Gonzalez-Montoro A, Cañizares G, Rezaei A, Nuyts J, Berr SS, Williams MB, Benlloch JM, Gonzalez AJ. Experimental validation of a rodent PET scanner prototype based on a single LYSO crystal tube. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022; 6:697-706. [PMID: 35909498 PMCID: PMC9328404 DOI: 10.1109/trpms.2021.3124448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Improving sensitivity and spatial resolution in small animal Positron Emission Tomography imaging instrumentation constitutes one of the main goals of nuclear imaging research. These parameters are degraded by the presence of gaps between the detectors. The present manuscript experimentally validates our prototype of an edge-less pre-clinical PET system based on a single LYSO:Ce annulus with an inner diameter of 62 mm and 10 outer facets of 26 × 52 mm2. Scintillation light is read out by arrays of 8 × 8 SiPMs coupled to the facets, using a projection readout of the rows and columns signals. The readout provides accurate Depth of Interaction (DOI). We have implemented a calibration that mitigates the DOI-dependency of the transaxial and axial impact coordinates, and the energy photopeak gain. An energy resolution of 23.4 ± 1.8% was determined. Average spatial resolution of 1.4 ± 0.2 and 1.3 ± 0.4 mm FWHM were achieved for the radial and axial directions, respectively. We found a peak sensitivity of 3.8% at the system center, and a maximum NECR at 40.6 kcps for 0.27 mCi. The image quality was evaluated using reconstructed images of an array of sources and the NEMA image quality phantom was also studied.
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Tobey H, Lucas T, Paul S, Berr SS, Mehrkens B, Brolinson PG, Klein BG, Costa BM. Mechanoceutics Alters Alzheimer's Disease Phenotypes in Transgenic Rats: A Pilot Study. J Alzheimers Dis 2021; 74:421-427. [PMID: 32039851 DOI: 10.3233/jad-191071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Current advancements in neurovascular biology relates a mechanoceutics treatment, known as cranial osteopathic manipulation (COM), Alzheimer's disease (AD). COM could be used as an evidence-based treatment strategy to improve the symptoms of AD if molecular mechanisms, which currently remain unclear, are elucidated. In the present pilot study, using transgenic rats, we have identified COM mediated changes in behavioral and biochemical parameters associated with AD phenotypes. We expect these changes may have functional implications that might account for improved clinical outcomes of COM treatment. Further investigations on COM will be helpful to establish an adjunct treatment for AD.
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Sheybani ND, Breza VR, Paul S, McCauley KS, Berr SS, Miller GW, Neumann KD, Price RJ. ImmunoPET-informed sequence for focused ultrasound-targeted mCD47 blockade controls glioma. J Control Release 2021; 331:19-29. [PMID: 33476735 PMCID: PMC7946780 DOI: 10.1016/j.jconrel.2021.01.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/11/2022]
Abstract
Phagocytic immunotherapies such as CD47 blockade have emerged as promising strategies for glioblastoma (GB) therapy, but the blood brain/tumor barriers (BBB/BTB) pose a persistent challenge for mCD47 delivery that can be overcome by focused ultrasound (FUS)-mediated BBB/BTB disruption. We here leverage immuno-PET imaging to determine how timing of [89Zr]-mCD47 injection relative to FUS impacts antibody penetrance into orthotopic murine gliomas. We then design and implement a rational paradigm for combining FUS and mCD47 for glioma therapy. We demonstrate that timing of antibody injection relative to FUS BBB/BTB disruption is a critical determinant of mCD47 access, with post-FUS injection conferring superlative antibody delivery to gliomas. We also show that mCD47 delivery across the BBB/BTB with repeat sessions of FUS can significantly constrain tumor outgrowth and extend survival in glioma-bearing mice. This study generates provocative insights for ongoing pre-clinical and clinical evaluations of FUS-mediated antibody delivery to brain tumors. Moreover, our results confirm that mCD47 delivery with FUS is a promising therapeutic strategy for GB therapy.
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Freire M, Gonzalez-Montoro A, Cañizares G, Berr SS, Vidal LF, Hernandez L, Gonzalez AJ. Calibration Methodology of an Edgeless PET System Prototype. IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD. NUCLEAR SCIENCE SYMPOSIUM 2020; 2020:10.1109/NSS/MIC42677.2020.9508042. [PMID: 34908824 PMCID: PMC8667022 DOI: 10.1109/nss/mic42677.2020.9508042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Instrumentation research in small animal Positron Emission Tomography (PET) imaging is driven by improving timing, spatial resolution and sensitivity. Conventional PET scanners are built of multiple detectors placed in a cylindrical geometry with gaps between them in both the transaxial and axial planes. These gaps decrease sensitivity and degrade spatial resolution towards the edges of the system field of view (FOV). To mitigate these problems, we have designed and validated an edgeless pre-clinical PET system based on a single LYSO annulus with an inner diameter of 62 mm and 10 outer facets of 26 × 52 mm2 each. The scintillation light is read out using the row and columns of Silicon Photomultipliers (SiPMs) mounted in magnetic-field compatible PCBs. The objective of this work is to provide a calibration method for this system. The particular design of the annulus produces some undesirable effects in the light distributions (LD) at the module joints, which needs to be addressed. Nevertheless, after calibration, the system allows one to properly retrieve both, the energy and 3D photon impact positions.
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Cui D, Drake JC, Wilson RJ, Shute RJ, Lewellen B, Zhang M, Zhao H, Sabik OL, Onengut S, Berr SS, Rich SS, Farber CR, Yan Z. A novel voluntary weightlifting model in mice promotes muscle adaptation and insulin sensitivity with simultaneous enhancement of autophagy and mTOR pathway. FASEB J 2020; 34:7330-7344. [PMID: 32304342 DOI: 10.1096/fj.201903055r] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/17/2020] [Accepted: 03/04/2020] [Indexed: 12/23/2022]
Abstract
Our understanding of the molecular mechanisms underlying adaptations to resistance exercise remains elusive despite the significant biological and clinical relevance. We developed a novel voluntary mouse weightlifting model, which elicits squat-like activities against adjustable load during feeding, to investigate the resistance exercise-induced contractile and metabolic adaptations. RNAseq analysis revealed that a single bout of weightlifting induced significant transcriptome responses of genes that function in posttranslational modification, metabolism, and muscle differentiation in recruited skeletal muscles, which were confirmed by increased expression of fibroblast growth factor-inducible 14 (Fn14), Down syndrome critical region 1 (Dscr1) and Nuclear receptor subfamily 4, group A, member 3 (Nr4a3) genes. Long-term (8 weeks) voluntary weightlifting training resulted in significantly increases of muscle mass, protein synthesis (puromycin incorporation in SUnSET assay) and mTOR pathway protein expression (raptor, 4e-bp-1, and p70S6K proteins) along with enhanced muscle power (specific torque and contraction speed), but not endurance capacity, mitochondrial biogenesis, and fiber type transformation. Importantly, weightlifting training profound improved whole-body glucose clearance and skeletal muscle insulin sensitivity along with enhanced autophagy (increased LC3 and LC3-II/I ratio, and decreased p62/Sqstm1). These data suggest that resistance training in mice promotes muscle adaptation and insulin sensitivity with simultaneous enhancement of autophagy and mTOR pathway.
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Tobey H, Lucas T, Bledsoe D, Mykins M, Campbell C, Berr SS, Sasser T, Helm R, Brolinson PG, Klein BG, Costa BM. Effect of Osteopathic Cranial Manipulative Medicine on an Aged Rat Model of Alzheimer Disease. THE JOURNAL OF THE AMERICAN OSTEOPATHIC ASSOCIATION 2019; 119:2753340. [PMID: 31613309 PMCID: PMC8425714 DOI: 10.7556/jaoa.2019.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
CONTEXT In the aging brain, reduction in the pulsation of cerebral vasculature and fluid circulation causes impairment in the fluid exchange between different compartments and lays a foundation for the neuroinflammation that results in Alzheimer disease (AD). The knowledge that lymphatic vessels in the central nervous system play a role in the clearance of brain-derived metabolic waste products opens an unprecedented capability to increase the clearance of macromolecules such as amyloid β proteins. However, currently there is no pharmacologic mechanism available to increase fluid circulation in the aging brain. OBJECTIVE To demonstrate the influence of an osteopathic cranial manipulative medicine (OCMM) technique, specifically, compression of the fourth ventricle, on spatial memory and changes in substrates associated with mechanisms of metabolic waste clearance in the central nervous system using the naturally aged rat model of AD. RESULTS Significant improvement was found in spatial memory in 6 rats after 7 days of OCMM sessions. Live animal positron emission tomographic imaging and immunoassays revealed that OCMM reduced amyloid β levels, activated astrocytes, and improved neurotransmission in the aged rat brains. CONCLUSION These findings demonstrate the molecular mechanism of OCMM in aged rats. This study and further investigations will help physicians promote OCMM as an evidence-based adjunctive treatment for patients with AD.
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Gonzalez AJ, Berr SS, Cañizares G, Gonzalez-Montoro A, Orero A, Correcher C, Rezaei A, Nuyts J, Sanchez F, Majewski S, Benlloch JM. Feasibility Study of a Small Animal PET Insert Based on a Single LYSO Monolithic Tube. Front Med (Lausanne) 2018; 5:328. [PMID: 30547030 PMCID: PMC6279866 DOI: 10.3389/fmed.2018.00328] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/09/2018] [Indexed: 11/26/2022] Open
Abstract
There are drawbacks with using a Positron Emission Tomography (PET) scanner design employing the traditional arrangement of multiple detectors in an array format. Typically PET systems are constructed with many regular gaps between the detector modules in a ring or box configuration, with additional axial gaps between the rings. Although this has been significantly reduced with the use of the compact high granularity SiPM photodetector technology, such a scanner design leads to a decrease in the number of annihilation photons that are detected causing lower scanner sensitivity. Moreover, the ability to precisely determine the line of response (LOR) along which the positron annihilated is diminished closer to the detector edges because the spatial resolution there is degraded due to edge effects. This happens for both monolithic based designs, caused by the truncation of the scintillation light distribution, but also for detector blocks that use crystal arrays with a number of elements that are larger than the number of photosensors and, therefore, make use of the light sharing principle. In this report we present a design for a small-animal PET scanner based on a single monolithic annulus-like scintillator that can be used as a PET insert in high-field Magnetic Resonance systems. We provide real data showing the performance improvement when edge-less modules are used. We also describe the specific proposed design for a rodent scanner that employs facetted outside faces in a single LYSO tube. In a further step, in order to support and prove the proposed edgeless geometry, simulations of that scanner have been performed and lately reconstructed showing the advantages of the design.
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Grainger AT, Tustison NJ, Qing K, Roy R, Berr SS, Shi W. Deep learning-based quantification of abdominal fat on magnetic resonance images. PLoS One 2018; 13:e0204071. [PMID: 30235253 PMCID: PMC6147491 DOI: 10.1371/journal.pone.0204071] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/09/2018] [Indexed: 01/02/2023] Open
Abstract
Obesity is increasingly prevalent and associated with increased risk of developing type 2 diabetes, cardiovascular diseases, and cancer. Magnetic resonance imaging (MRI) is an accurate method for determination of body fat volume and distribution. However, quantifying body fat from numerous MRI slices is tedious and time-consuming. Here we developed a deep learning-based method for measuring visceral and subcutaneous fat in the abdominal region of mice. Congenic mice only differ from C57BL/6 (B6) Apoe knockout (Apoe-/-) mice in chromosome 9 that is replaced by C3H/HeJ genome. Male congenic mice had lighter body weight than B6-Apoe-/- mice after being fed 14 weeks of Western diet. Axial and coronal T1-weighted sequencing at 1-mm-thickness and 1-mm-gap was acquired with a 7T Bruker ClinScan scanner. A deep learning approach was developed for segmenting visceral and subcutaneous fat based on the U-net architecture made publicly available through the open-source ANTsRNet library—a growing repository of well-known neural networks. The volumes of subcutaneous and visceral fat measured through our approach were highly comparable with those from manual measurements. The Dice score, root-mean-square error (RMSE), and correlation analysis demonstrated the similarity between two methods in quantifying visceral and subcutaneous fat. Analysis with the automated method showed significant reductions in volumes of visceral and subcutaneous fat but not non-fat tissues in congenic mice compared to B6 mice. These results demonstrate the accuracy of deep learning in quantification of abdominal fat and its significance in determining body weight.
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Byrne FL, Hargett SR, Lahiri S, Roy RJ, Berr SS, Caldwell SH, Hoehn KL. Serial MRI Imaging Reveals Minimal Impact of Ketogenic Diet on Established Liver Tumor Growth. Cancers (Basel) 2018; 10:E312. [PMID: 30189621 PMCID: PMC6162796 DOI: 10.3390/cancers10090312] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 08/29/2018] [Accepted: 09/04/2018] [Indexed: 11/16/2022] Open
Abstract
Rodent models of liver tumorigenesis have reproducibly shown that dietary sugar intake is a powerful driver of liver tumor initiation and growth. In contrast, dietary sugar restriction with ketogenic diets or calorie restriction generally prevents liver tumor formation. Ketogenic diet is viewed positively as a therapeutic adjuvant; however, most ketogenic diet studies described to date have been performed in prevention mode rather than treatment mode. Therefore, it remains unclear whether a ketogenic diet can be administered in late stages of disease to stall or reverse liver tumor growth. To model the clinically relevant treatment mode, we administered a ketogenic diet to mice after liver tumor initiation and monitored tumor growth by magnetic resonance imaging (MRI). Male C57BL/6 mice were injected with diethylnitrosamine (DEN) at 2 weeks of age and fed a chow diet until 39 weeks of age, when they underwent MRI imaging to detect liver tumors. Mice were then randomised into two groups and fed either a chow diet or switched to a ketogenic diet from 40⁻48 weeks of age. Serial MRIs were performed at 44 and 48 weeks of age. All mice had tumors at study completion and there were no differences in total tumor burden between diet groups. Although a ketogenic diet has marked protective effects against DEN-induced liver tumourigenesis in this mouse model, these data demonstrate that ketogenic diet cannot stop the progression of established liver tumors.
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Cheng B, He H, Huang T, Berr SS, He J, Fan D, Zhang J, Xu P. Gold Nanosphere Gated Mesoporous Silica Nanoparticle Responsive to Near-Infrared Light and Redox Potential as a Theranostic Platform for Cancer Therapy. J Biomed Nanotechnol 2016; 12:435-49. [PMID: 26949379 DOI: 10.1166/jbn.2016.2195] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A gold/mesoporous silica hybrid nanoparticle (GoMe), which possesses the best of both conventional gold nanoparticles and mesoporous silica nanoparticles, such as excellent photothermal converting ability as well as high drug loading capacity and triggerable drug release, has been developed. In contrast to gold nanorod and other heat generating gold nanoparticles, GoMe is photothermal stable and can be repetitively activated through NIR irradiation. Doxorubicin loaded GoMe (DOX@GoMe) is sensitive to both NIR irradiation and intracellularly elevated redox potential. DOX@GoMe coupled with NIR irradiation exhibits a synergistic effect of photothermal therapy and chemotherapy in killing cancer cells. Furthermore, 64Cu-labeled GoMe can successfully detect the existence of clinically relevant spontaneous lung tumors in a urethane-induced lung cancer mouse model through PET imaging. Altogether, GoMe can be utilized as an effective theranostic platform for cancer therapy.
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Li Y, Huang T, Zhang X, Zhong M, Walker NN, He J, Berr SS, Keller SR, Kundu BK. Determination of Fatty Acid Metabolism with Dynamic [
11
C]Palmitate Positron Emission Tomography of Mouse Heart In Vivo. Mol Imaging 2015. [DOI: 10.2310/7290.2015.00024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Li Y, Huang T, Zhang X, Zhong M, Walker NN, He J, Berr SS, Keller SR, Kundu BK. Determination of Fatty Acid Metabolism with Dynamic [11C]Palmitate Positron Emission Tomography of Mouse Heart In Vivo. Mol Imaging 2015; 14:516-525. [PMID: 26462138 PMCID: PMC4625801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023] Open
Abstract
The goal of this study was to establish a quantitative method for measuring fatty acid (FA) metabolism with partial volume (PV) and spill-over (SP) corrections using dynamic [(11)C]palmitate positron emission tomographic (PET) images of mouse heart in vivo. Twenty-minute dynamic [(11)C]palmitate PET scans of four 18- to 20-week-old male C57BL/6 mice under isoflurane anesthesia were performed using a Focus F-120 PET scanner. A model-corrected blood input function, by which the input function with SP and PV corrections and the metabolic rate constants (k1-k5) are simultaneously estimated from the dynamic [(11)C]palmitate PET images of mouse hearts in a four-compartment tracer kinetic model, was used to determine rates of myocardial fatty acid oxidation (MFAO), myocardial FA esterification, myocardial FA use, and myocardial FA uptake. The MFAO thus measured in C57BL/6 mice was 375.03 ± 43.83 nmol/min/g. This compares well to the MFAO measured in perfused working C57BL/6 mouse hearts ex vivo of about 350 nmol/g/min and 400 nmol/min/g. FA metabolism was measured for the first time in mouse heart in vivo using dynamic [(11)C]palmitate PET in a four-compartment tracer kinetic model. MFAO obtained with this model was validated by results previously obtained with mouse hearts ex vivo.
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Banizs AB, Huang T, Dryden K, Berr SS, Stone JR, Nakamoto RK, Shi W, He J. In vitro evaluation of endothelial exosomes as carriers for small interfering ribonucleic acid delivery. Int J Nanomedicine 2014; 9:4223-30. [PMID: 25214786 PMCID: PMC4159392 DOI: 10.2147/ijn.s64267] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Exosomes, one subpopulation of nanosize extracellular vesicles derived from multivesicular bodies, ranging from 30 to 150 nm in size, emerged as promising carriers for small interfering ribonucleic acid (siRNA) delivery, as they are capable of transmitting molecular messages between cells through carried small noncoding RNAs, messenger RNAs, deoxyribonucleic acids, and proteins. Endothelial cells are involved in a number of important biological processes, and are a major source of circulating exosomes. In this study, we prepared exosomes from endothelial cells and evaluated their capacity to deliver siRNA into primary endothelial cells. Exosomes were isolated and purified by sequential centrifugation and ultracentrifugation from cultured mouse aortic endothelial cells. Similar to exosome particles from other cell sources, endothelial exosomes are nanometer-size vesicles, examined by both the NanoSight instrument and transmission electron microscopy. Enzyme-linked immunosorbent assay analysis confirmed the expression of two exosome markers: CD9 and CD63. Flow cytometry and fluorescence microscopy studies demonstrated that endothelial exosomes were heterogeneously distributed within cells. In a gene-silencing study with luciferase-expressing endothelial cells, exosomes loaded with siRNA inhibited luciferase expression by more than 40%. In contrast, siRNA alone and control siRNA only suppressed luciferase expression by less than 15%. In conclusion, we demonstrated that endothelial exosomes have the capability to accommodate and deliver short foreign nucleic acids into endothelial cells.
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Stout D, Berr SS, LeBlanc A, Kalen JD, Osborne D, Price J, Schiffer W, Kuntner C, Wall J. Guidance for methods descriptions used in preclinical imaging papers. Mol Imaging 2013; 12:1-15. [PMID: 23920252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
Preclinical molecular imaging is a rapidly growing field, where new imaging systems, methods, and biological findings are constantly being developed or discovered. Imaging systems and the associated software usually have multiple options for generating data, which is often overlooked but is essential when reporting the methods used to create and analyze data. Similarly, the ways in which animals are housed, handled, and treated to create physiologically based data must be well described in order that the findings be relevant, useful, and reproducible. There are frequently new developments for metabolic imaging methods. Thus, specific reporting requirements are difficult to establish; however, it remains essential to adequately report how the data have been collected, processed, and analyzed. To assist with future manuscript submissions, this article aims to provide guidelines of what details to report for several of the most common imaging modalities. Examples are provided in an attempt to give comprehensive, succinct descriptions of the essential items to report about the experimental process.
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Stout D, Berr SS, LeBlanc A, Kalen JD, Osborne D, Price J, Schiffer W, Kuntner C, Wall J. Guidance for Methods Descriptions Used in Preclinical Imaging Papers. Mol Imaging 2013. [DOI: 10.2310/7290.2013.00055] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Sen S, Kundu BK, Wu HCJ, Hashmi SS, Guthrie P, Locke LW, Roy RJ, Matherne GP, Berr SS, Terwelp M, Scott B, Carranza S, Frazier OH, Glover DK, Dillmann WH, Gambello MJ, Entman ML, Taegtmeyer H. Glucose regulation of load-induced mTOR signaling and ER stress in mammalian heart. J Am Heart Assoc 2013; 2:e004796. [PMID: 23686371 PMCID: PMC3698799 DOI: 10.1161/jaha.113.004796] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Changes in energy substrate metabolism are first responders to hemodynamic stress in the heart. We have previously shown that hexose-6-phosphate levels regulate mammalian target of rapamycin (mTOR) activation in response to insulin. We now tested the hypothesis that inotropic stimulation and increased afterload also regulate mTOR activation via glucose 6-phosphate (G6P) accumulation. METHODS AND RESULTS We subjected the working rat heart ex vivo to a high workload in the presence of different energy-providing substrates including glucose, glucose analogues, and noncarbohydrate substrates. We observed an association between G6P accumulation, mTOR activation, endoplasmic reticulum (ER) stress, and impaired contractile function, all of which were prevented by pretreating animals with rapamycin (mTOR inhibition) or metformin (AMPK activation). The histone deacetylase inhibitor 4-phenylbutyrate, which relieves ER stress, also improved contractile function. In contrast, adding the glucose analogue 2-deoxy-d-glucose, which is phosphorylated but not further metabolized, to the perfusate resulted in mTOR activation and contractile dysfunction. Next we tested our hypothesis in vivo by transverse aortic constriction in mice. Using a micro-PET system, we observed enhanced glucose tracer analog uptake and contractile dysfunction preceding dilatation of the left ventricle. In contrast, in hearts overexpressing SERCA2a, ER stress was reduced and contractile function was preserved with hypertrophy. Finally, we examined failing human hearts and found that mechanical unloading decreased G6P levels and ER stress markers. CONCLUSIONS We propose that glucose metabolic changes precede and regulate functional (and possibly also structural) remodeling of the heart. We implicate a critical role for G6P in load-induced mTOR activation and ER stress.
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Xiao L, Zhang Y, Berr SS, Chordia MD, Pramoonjago P, Pu L, Pan D. A novel near-infrared fluorescence imaging probe for in vivo neutrophil tracking. Mol Imaging 2012; 11:372-382. [PMID: 22954181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023] Open
Abstract
The development and validation of a multiscopic near-infrared fluorescence (NIRF) probe, cinnamoyl-F-(D)L-F-(D)L-F-PEG-cyanine7 (cFlFlF-PEG-Cy7), that targets formyl peptide receptor on neutrophils using a mice ear inflammation model is described. Acute inflammation was induced in mice by topical application of phorbol-12-myristate-13-acetate to left ears 24 hours before probe administration. Noninvasive NIRF imaging was longitudinally performed up to 24 hours following probe injection. The in vivo neutrophil-targeting specificity of the probe was characterized by a blocking study with preadministration of excess nonfluorescent peptide cFlFlF-PEG and by an imaging study with a scrambled peptide probe cLFFFL-PEG-Cy7. NIRF imaging of mice injected with cinnamoyl-L-F-F-F-L-PEG-cyanine7 (cFlFlF-PEG-Cy7) revealed that the fluorescence intensity for inflamed left ears was approximately fourfold higher than that of control right ears at 24 hours postinjection. In comparison, the ratios acquired with the scrambled probe and from the blocking study were 1.5- and 2-fold at 24 hours postinjection, respectively. Moreover, a microscopic immunohistologic study confirmed that the NIRF signal of cFlFlF-PEG-Cy7 was associated with activated neutrophils in the inflammatory tissue. With this probe, in vivo neutrophil chemotaxis could be correlatively imaged macroscopically in live animals and microscopically at tissue and cellular levels.
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Xiao L, Zhang Y, Berr SS, Chordia MD, Pramoonjago P, Pu L, Pan D. A Novel Near-Infrared Fluorescence Imaging Probe for in Vivo Neutrophil Tracking. Mol Imaging 2012. [DOI: 10.2310/7290.2011.00054] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Locke LW, Mayo MW, Yoo AD, Williams MB, Berr SS. PET imaging of tumor associated macrophages using mannose coated 64Cu liposomes. Biomaterials 2012; 33:7785-93. [PMID: 22840225 DOI: 10.1016/j.biomaterials.2012.07.022] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 07/09/2012] [Indexed: 01/25/2023]
Abstract
Macrophages within the tumor microenvironment (TAMs) have been shown to play a major role in the growth and spread of many types of cancer. Cancer cells produce cytokines that cause macrophages to express scavenger receptors (e.g. the mannose receptor) and factors that facilitate tissue and blood vessel growth, suppress T cell mediated anti-tumor activity, and express enzymes that can break down the extracellular matrix, thereby promoting metastasis. We have designed a mannosylated liposome (MAN-LIPs) and show that it accumulates in TAMs in a mouse model of pulmonary adenocarcinoma. These liposomes are loaded with (64)Cu to allow tracking by PET imaging, and contain a fluorescent dye in the lipid bilayer permitting subsequent fluorescence microscopy. We injected these liposomes into a mouse model of lung cancer. In vivo PET images were acquired 6 h after injection followed by the imaging of select excised organs. MAN-LIPs accumulated in TAMs and exhibited little accumulation in remote lung areas. MAN-LIPs are a promising new vehicle for the delivery of imaging agents to lung TAMs. In addition to imaging, MAN-LIPs hold the potential for delivery of therapeutic agents to the tumor microenvironment.
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West AM, Anderson JD, Epstein FH, Meyer CH, Hagspiel KD, Berr SS, Harthun NL, Weltman AL, Annex BH, Kramer CM. Percutaneous intervention in peripheral artery disease improves calf muscle phosphocreatine recovery kinetics: a pilot study. Vasc Med 2012; 17:3-9. [PMID: 22363013 DOI: 10.1177/1358863x11431837] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We hypothesized that percutaneous intervention in the affected lower extremity artery would improve calf muscle perfusion and cellular metabolism in patients with claudication and peripheral artery disease (PAD) as measured by magnetic resonance imaging (MRI) and spectroscopy (MRS). Ten patients with symptomatic PAD (mean ± SD: age 57 ± 9 years; ankle-brachial index (ABI) 0.62 ± 0.17; seven males) were studied 2 months before and 10 months after lower extremity percutaneous intervention. Calf muscle phosphocreatine recovery time constant (PCr) in the revascularized leg was measured by (31)P MRS immediately after symptom-limited exercise on a 1.5-T scanner. Calf muscle perfusion was measured using first-pass gadolinium-enhanced MRI at peak exercise. A 6-minute walk and treadmill test were performed. The PCr recovery time constant improved significantly following intervention (91 ± 33 s to 52 ± 34 s, p < 0.003). Rest ABI also improved (0.62 ± 0.17 to 0.93 ± 0.25, p < 0.003). There was no difference in MRI-measured tissue perfusion or exercise parameters, although the study was underpowered for these endpoints. In conclusion, in this pilot study, successful large vessel percutaneous intervention in patients with symptomatic claudication, results in improved ABI and calf muscle phosphocreatine recovery kinetics.
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Beyers RJ, Smith RS, Xu Y, Piras BA, Salerno M, Berr SS, Meyer CH, Kramer CM, French BA, Epstein FH. T2-weighted MRI of post-infarct myocardial edema in mice. Magn Reson Med 2011. [DOI: 10.1002/mrm.24160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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West AM, Pesch AJ, Mehta N, Anderson JD, Epstein FH, Meyer CH, Hagspiel KD, Berr SS, Harthun NL, Hunter JR, DiMaria JM, Christopher JM, Kramer CM. Changes in atherosclerotic plaque composition assessed by MRI in the superficial femoral artery with two years of lipid lowering therapy. J Cardiovasc Magn Reson 2011. [PMCID: PMC3106898 DOI: 10.1186/1532-429x-13-s1-p382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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West AM, Anderson JD, Meyer CH, Epstein FH, Wang H, Hagspiel KD, Berr SS, Harthun NL, DiMaria JM, Hunter JR, Christopher JM, Chew JD, Winberry GB, Kramer CM. The effect of ezetimibe on peripheral arterial atherosclerosis depends upon statin use at baseline. Atherosclerosis 2011; 218:156-62. [PMID: 21570685 PMCID: PMC3157540 DOI: 10.1016/j.atherosclerosis.2011.04.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 03/22/2011] [Accepted: 04/04/2011] [Indexed: 11/23/2022]
Abstract
BACKGROUND Both statins and ezetimibe lower LDL-C, but ezetimibe's effect on atherosclerosis is controversial. We hypothesized that lowering LDL-C cholesterol by adding ezetimibe to statin therapy would regress atherosclerosis measured by magnetic resonance imaging (MRI) in the superficial femoral artery (SFA) in peripheral arterial disease (PAD). METHODS Atherosclerotic plaque volume was measured in the proximal 15-20 cm of the SFA in 67 PAD patients (age 63 ± 10, ABI 0.69 ± 0.14) at baseline and annually × 2. Statin-naïve patients (n=34) were randomized to simvastatin 40 mg (S, n=16) or simvastatin 40 mg+ezetimibe 10mg (S+E, n=18). Patients already on statins but with LDL-C >80 mg/dl had open-label ezetimibe 10mg added (E, n=33). Repeated measures models estimated changes in plaque parameters over time and between-group differences. RESULTS LDL-C was lower at year 1 in S+E (67 ± 7 mg/dl) than S (91 ± 8 mg/dl, p<0.05), but similar at year 2 (68 ± 10 mg/dl vs. 83 ± 11 mg/dl, respectively). Plaque volume did not change from baseline to year 2 in either S+E (11.5 ± 1.4-10.5 ± 1.3 cm(3), p=NS) or S (11.0 ± 1.5-10.5 ± 1.4 cm(3), p=NS). In E, plaque progressed from baseline to year 2 (10.0 ± 0.8-10.8 ± 0.9, p<0.01) despite a 22% decrease in LDL-C. CONCLUSIONS Statin initiation with or without ezetimibe in statin-naïve patients halts progression of peripheral atherosclerosis. When ezetimibe is added to patients previously on statins, peripheral atherosclerosis progressed. Thus, ezetimibe's effect on peripheral atherosclerosis may depend upon relative timing of statin therapy.
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West AM, Anderson JD, Epstein FH, Meyer CH, Wang H, Hagspiel KD, Berr SS, Harthun NL, Weltman AL, DiMaria JM, Hunter JR, Christopher JM, Kramer CM. Low-density lipoprotein lowering does not improve calf muscle perfusion, energetics, or exercise performance in peripheral arterial disease. J Am Coll Cardiol 2011; 58:1068-76. [PMID: 21867844 PMCID: PMC3182461 DOI: 10.1016/j.jacc.2011.04.034] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2010] [Revised: 03/02/2011] [Accepted: 04/19/2011] [Indexed: 01/12/2023]
Abstract
OBJECTIVES We hypothesized that low-density lipoprotein (LDL) reduction regardless of mechanism would improve calf muscle perfusion, energetics, or walking performance in peripheral arterial disease (PAD) as measured by magnetic resonance imaging and magnetic resonance spectroscopy. BACKGROUND Statins improve cardiovascular outcome in PAD, and some studies suggest improved walking performance. METHODS Sixty-eight patients with mild to moderate symptomatic PAD (age 65 ± 11 years; ankle-brachial index [ABI] 0.69 ± 0.14) were studied at baseline and annually for 2 years after beginning simvastatin 40 mg (n = 20) or simvastatin 40 mg/ezetimibe 10 mg (n = 18) if statin naïve, or ezetimibe 10 mg (n = 30) if taking a statin. Phosphocreatine recovery time was measured by (31)P magnetic resonance spectroscopy immediately after symptom-limited calf exercise on a 1.5-T scanner. Calf perfusion was measured using first-pass contrast-enhanced magnetic resonance imaging with 0.1 mM/kg gadolinium at peak exercise. Gadolinium-enhanced magnetic resonance angiography was graded. A 6-min walk and a standardized graded Skinner-Gardner exercise treadmill test with peak Vo(2) were performed. A repeated-measures model compared changes over time. RESULTS LDL reduction from baseline to year 2 was greater in the simvastatin 40 mg/ezetimibe 10 mg group (116 ± 42 mg/dl to 56 ± 21 mg/dl) than in the simvastatin 40 mg group (129 ± 40 mg/dl to 90 ± 30 mg/dl, p < 0.01). LDL also decreased in the ezetimibe 10 mg group (102 ± 28 mg/dl to 79 ± 27 mg/dl, p < 0.01). Despite this, there was no difference in perfusion, metabolism, or exercise parameters between groups or over time. Resting ABI did improve over time in the ezetimibe 10 mg group and the entire study group of patients. CONCLUSIONS Despite effective LDL reduction in PAD, neither tissue perfusion, metabolism, nor exercise parameters improved, although rest ABI did. Thus, LDL lowering does not improve calf muscle physiology or functional capacity in PAD. (Comprehensive Magnetic Resonance of Peripheral Arterial Disease; NCT00587678).
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Beyers RJ, Smith RS, Xu Y, Piras BA, Salerno M, Berr SS, Meyer CH, Kramer CM, French BA, Epstein FH. T₂ -weighted MRI of post-infarct myocardial edema in mice. Magn Reson Med 2011; 67:201-9. [PMID: 21630350 DOI: 10.1002/mrm.22975] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Revised: 02/28/2011] [Accepted: 04/04/2011] [Indexed: 11/11/2022]
Abstract
T(2) -weighted, cardiac magnetic resonance imaging (T(2) w CMR) can be used to noninvasively detect and quantify the edematous region that corresponds to the area at risk (AAR) following myocardial infarction (MI). Previously, CMR has been used to examine structure and function in mice, expediting the study of genetic manipulations. To date, CMR has not been applied to imaging of post-MI AAR in mice. We developed a whole-heart, T(2) w CMR sequence to quantify the AAR in mouse models of ischemia and infarction. The ΔB(0) and ΔB(1) environment around the mouse heart at 7 T were measured, and a T(2) -preparation sequence suitable for these conditions was developed. Both in vivo T(2) w and late gadolinium enhanced CMR were performed in mice after 20-min coronary occlusions, resulting in measurements of AAR size of 32.5 ± 3.1 (mean ± SEM)% left ventricular mass, and MI size of 50.1 ± 6.4% AAR size. Excellent interobserver agreement and agreement with histology were also found. This T(2) w imaging method for mice may allow for future investigations of genetic manipulations and novel therapies affecting the AAR and salvaged myocardium following reperfused MI.
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