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https://www.readbyqxmd.com/read/29777820/accuracy-and-precision-of-quantitative-dce-mri-parameters-how-should-one-estimate-contrast-concentration
#1
Nicole Wake, Hersh Chandarana, Henry Rusinek, Koji Fujimoto, Linda Moy, Daniel K Sodickson, Sungheon Gene Kim
INTRODUCTION: Pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE-MRI) data are sensitive to acquisition and post-processing techniques, which makes it difficult to compare results obtained using different methods. In particular, one of the most important factors affecting estimation of model parameters is how to convert MRI signal intensities to contrast agent concentration. The purpose of our study was to quantitatively compare a linear signal-to-concentration conversion (LC) as an approximation and a non-linear conversion (NLC) based on the MRI signal equation, in terms of the accuracy and precision of the pharmacokinetic parameters in T1 -weighted DCE-MRI...
May 16, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29777389/iron-based-metal-organic-frameworks-as-a-theranostic-carrier-for-local-tuberculosis-therapy
#2
Gabriela Wyszogrodzka, Przemysław Dorożyński, Barbara Gil, Wieslaw J Roth, Maciej Strzempek, Bartosz Marszałek, Władysław P Węglarz, Elżbieta Menaszek, Weronika Strzempek, Piotr Kulinowski
PURPOSE: The purpose of the study was initial evaluation of applicability of metal organic framework (MOF) Fe-MIL-101-NH2 as a theranostic carrier of antituberculous drug in terms of its functionality, i.e. drug loading, drug dissolution, magnetic resonance imaging (MRI) contrast and cytotoxic safety. METHODS: Fe-MIL-101-NH2 was characterized using X-ray powder diffraction, FTIR spectrometry and scanning electron microscopy. The particle size analysis was determined using laser diffraction...
May 18, 2018: Pharmaceutical Research
https://www.readbyqxmd.com/read/29777330/down-regulating-il-6-gp130-targets-improved-the-anti-tumor-effects-of-5-fluorouracil-in-colon-cancer
#3
Sanhong Li, Jilai Tian, Hongming Zhang, Shoubing Zhou, Xiyong Wang, Lei Zhang, Jiapeng Yang, Zhigang Zhang, Zhenling Ji
Recent studies have confirmed that IL-6/GP130 targets are closely associated with tumor growth, metastasis and drug resistance. 5-Fluorouracil (5-FU) is the most common chemotherapeutic agent for colon cancer but is limited due to chemoresistance and high cytotoxicity. Bazedoxifene (BZA), a third-generation selective estrogen receptor modulator, was discovered by multiple ligand simultaneous docking and drug repositioning approaches to have a novel function as an IL-6/GP130 target inhibitor. Thus, we speculated that in colon cancer, the anti-tumor efficacy of 5-FU might be increased in combination with IL-6/GP130 inhibitors...
May 18, 2018: Apoptosis: An International Journal on Programmed Cell Death
https://www.readbyqxmd.com/read/29776458/hydrocephalus-after-intrathecal-administration-of-dextran-to-rhesus-macaques-macaca-mulatta
#4
Jason P Dufour, Kasi E Russell-Lodrigue, Lara Doyle-Meyers, Kathrine P Falkenstein, Robert V Blair, Elizabeth S Didier, Nadia Slisarenko, Kenneth C Williams, Marcelo J Kuroda
Dextrans have been used extensively as medical therapies and labeling agents in biomedical research to investigate theblood-brain barrier and CSF flow and absorption. Adverse effects from dextrans include anaphylactic reaction and dilation ofthe cerebral ventricles due to administration into the subarachnoid space. This retrospective study describes 51 rhesus macaques(Macaca mulatta) that received dextran intrathecally. The purpose of intrathecal administration was to enable detection oflong-lived, dextran-labeled macrophages and to study monocyte-macrophage turnover in the CNS of SIV- or SHIV- infectedand uninfected animals by using immunofluorescence...
May 18, 2018: Comparative Medicine
https://www.readbyqxmd.com/read/29775791/an-imaging-biomarker-for-assessing-hepatic-function-in-patients-with-primary-sclerosing-cholangitis
#5
Jennifer Schulze, Henrike Lenzen, Jan B Hinrichs, Burckhardt Ringe, Michael P Manns, Frank Wacker, Kristina I Ringe
BACKGROUND & AIMS: We aimed to evaluate the potential of hepatobiliary phase magnetic resonance imaging (MRI) as parameter for assessment of hepatocellular function in patients with primary sclerosing cholangitis (PSC). METHODS: We collected data from 111 patients (83 male, 28 female; median, 44 years old), from March 2012 through March 2016, with a confirmed diagnosis of PSC who underwent MRI evaluation before and after injection (hepatobiliary phase) of a hepatocyte-specific contrast agent (gadoxetate disodium)...
May 15, 2018: Clinical Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/29774529/inhibition-of-prmt3-activity-selectively-impairs-lxr-driven-transcription-of-hepatic-lipogenic-genes-in-vivo
#6
Joya E Nahon, Christianne Groeneveldt, Janine J Geerling, Miranda Van Eck, Menno Hoekstra
BACKGROUND AND PURPOSE: Agonists for the liver X receptor (LXR) are considered promising therapeutic moieties in cholesterol-driven diseases by promoting cellular cholesterol efflux pathways. However, current clinical application of these agents is hampered by the concomitant LXR-induced activation of a lipogenic transcriptional network, leading to hepatic steatosis. Recent studies have suggested that protein arginine methyltransferase 3 (PRMT3) may act as a selective co-activator of LXR activity...
May 18, 2018: British Journal of Pharmacology
https://www.readbyqxmd.com/read/29774188/gadofosveset-enhanced-magnetic-resonance-imaging-as-a-problem-solving-tool-for-diagnosing-colorectal-liver-metastases-a-case-report
#7
Helen Cheung, Paul Karanicolas, Natalie Coburn, Calvin Law, Laurent Milot
Due to significant improvements in morbidity and mortality, surgery with curative intent is now the standard of care for patients with colorectal liver metastases who are surgical candidates. As a result, highly accurate preoperative per-lesion diagnosis is crucial. However, in some instances, this remains limited with standard techniques, including magnetic resonance imaging (MRI) with conventional contrast agents. Delayed retention of contrast of fibrotic liver metastases on MRI with extracellular contrast agents may mimic the late retention of contrast in hemangiomas and represent a diagnostic pitfall that limits diagnosis...
April 2018: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/29774185/protein-modified-ultra-small-gold-clusters-for-dual-modal-in-vivo-fluorescence-photoacoustic-imaging
#8
Duyang Gao, Yubin Liu, Yating Wang, Zhen Yuan
Background: Construction of nanoprobes for dual-modal fluorescence/photoacoustic imaging (PAI) is of great importance for the detection of disease pathology and the development of innovative therapeutics. Previously ultra-small gold clusters were designed and used as contrast agents for fluorescence imaging (FLI). However, it is not clear whether they can also serve as promising probes for PAI. In this study, protein-modified ultra-small gold clusters are produced and examined quantitatively as enhanced contrast agents for dual-modal in vivo fluorescence and PAI...
April 2018: Quantitative Imaging in Medicine and Surgery
https://www.readbyqxmd.com/read/29774103/bevacizumab-exacerbates-sinusoidal-obstruction-syndrome-sos-in-the-animal-model-and-increases-mmp-9-production
#9
Azin Jafari, Hanno Matthaei, Sven Wehner, Tolga Tonguc, Jörg C Kalff, Steffen Manekeller
Background: Thanks to modern multimodal treatment the ouctome of patients with colorectal cancer has experienced significant improvements. As a downside, agent specific side effects have been observed such as sinusoidal obstruction syndrome (SOS) after oxaliplatin chemotherapy (OX). Bevazicumab targeting VEGF is nowadays comprehensively used in combination protocols with OX but its impact on hepatotoxicity is thus far elusive and focus of the present study. Results: After MCT administration 67% of animals developed SOS...
April 24, 2018: Oncotarget
https://www.readbyqxmd.com/read/29774069/a-large-switchable-optical-clearing-skull-window-for-cerebrovascular-imaging
#10
Chao Zhang, Wei Feng, Yanjie Zhao, Tingting Yu, Pengcheng Li, Tonghui Xu, Qingming Luo, Dan Zhu
Rationale: Intravital optical imaging is a significant method for investigating cerebrovascular structure and function. However, its imaging contrast and depth are limited by the turbid skull. Tissue optical clearing has a great potential for solving this problem. Our goal was to develop a transparent skull window, without performing a craniotomy, for use in assessing cerebrovascular structure and function. Methods: Skull optical clearing agents were topically applied to the skulls of mice to create a transparent window within 15 min...
2018: Theranostics
https://www.readbyqxmd.com/read/29774066/caveolae-mediated-mesenchymal-stem-cell-labelling-by-pss-coated-plga-pfob-nano-contrast-agent-for-mri
#11
Hieu Vu Quang, Chi-Chih Chang, Ping Song, Ellen-Margrethe Hauge, Jørgen Kjems
Rationale: Non-invasive tracking of transplanted cells is critical in evaluating delivery, migration and prognosis of cell therapies. Methods: We formulated a nano-contrast agent consisting of a perfluorooctylbromide (PFOB) core within a shell of poly (lactic-co-glycolic acid) (PLGA) followed by a coat of polystyrene sulfonate (PSS) for 19 F MRI. The nano-contrast agent (PSS-NP) was characterised by DLS and the uptake efficiency of the nano-contrast agent (PSS-NP) was tested using flow cytometry, in vitro MRI and confocal microscopy...
2018: Theranostics
https://www.readbyqxmd.com/read/29773187/gd-accumulation-in-tissues-of-healthy-mice-upon-repeated-administrations-of-gadodiamide-and-gadoteridol
#12
Enza Di Gregorio, Rebecca Iani, Giuseppe Ferrauto, Raffaele Nuzzi, Silvio Aime, Eliana Gianolio
The aim of this work was to investigate, by five different administration protocols, the impact of the dosage, the time passed after the last injection and the frequency of injections, on accumulation and distribution of Gd-containing species in the body tissues of healthy mice upon repeated injections of Gadolinium Based Contrast Agents (GBCAs). Gadodiamide and Gadoteridol have been compared. The amount of Gd retained in several tissues/organs (cerebrum, cerebellum, spleen, liver, kidneys, eyes, skin, bone and muscle) has been assessed by ICP-MS upon administration of the GBCAs i) at three weeks or three months after the last administration, ii) when one, three or twelve doses of GBCA were administered and iii) when administrations were made every two weeks...
July 2018: Journal of Trace Elements in Medicine and Biology
https://www.readbyqxmd.com/read/29772311/mid-term-outcomes-of-endovascular-aortic-aneurysm-repair-with-carbon-dioxide-guided-angiography
#13
Yuriko Takeuchi, Noriyasu Morikage, Yutaro Matsuno, Tamami Nakamura, Makoto Samura, Koshiro Ueda, Takasuke Harada, Yoshitaka Ikeda, Kotaro Suehiro, Hiroshi Ito, Kensuke Sakata, Kimikazu Hamano
BACKGROUND: Although iodinated contrast (IC) agents are commonly used in endovascular aneurysm repair (EVAR), perioperative use in patients with renal dysfunction or IC allergies is avoided. Carbon dioxide (CO2 )-guided angiography is a promising alternative. We aimed to evaluate short-term and mid-term outcomes of EVAR using CO2 -guided angiography. METHODS: Three hundred and eighty-one patients who underwent EVAR from January 2012 to September 2016 were retrospectively reviewed and divided into an IC-EVAR group (n=351) and CO2 -EVAR group (n=30)...
May 14, 2018: Annals of Vascular Surgery
https://www.readbyqxmd.com/read/29772242/synthesis-molecular-modeling-and-biological-evaluation-of-potent-analogs-of-2-methoxyestradiol
#14
Nora Al-Kazaale, Phuong T Tran, Farhad Haidari, Eirik Johansson Solum, Sandra Liekens, Peter Vervaeke, Ingebrigt Sylte, Jing-Jy Cheng, Anders Vik, Trond Vidar Hansen
The endogenous steroid 2-methoxyestradiol (1) has attracted a great interest as a lead compound towards the development of new anti-cancer drugs. Herein, the synthesis, molecular modeling, anti-proliferative and anti-angiogenic effects of ten 2-ethyl and four 2-methoxy analogs of estradiol are reported. The ethyl group was introduced to the steroid A-ring using a novel Friedel-Crafts alkylation protocol. Several analogs displayed potent anti-proliferative activity with IC50 -values in the submicromolar range towards the CEM human leukemia cancer cell line...
May 14, 2018: Steroids
https://www.readbyqxmd.com/read/29771999/growth-medium-dependent-antimicrobial-activity-of-early-stage-mep-pathway-inhibitors
#15
Sara Sanders, David Bartee, Mackenzie J Harrison, Paul D Phillips, Andrew T Koppisch, Caren L Freel Meyers
The in vivo microenvironment of bacterial pathogens is often characterized by nutrient limitation. Consequently, conventional rich in vitro culture conditions used widely to evaluate antibacterial agents are often poorly predictive of in vivo activity, especially for agents targeting metabolic pathways. In one such pathway, the methylerythritol phosphate (MEP) pathway, which is essential for production of isoprenoids in bacterial pathogens, relatively little is known about the influence of growth environment on antibacterial properties of inhibitors targeting enzymes in this pathway...
2018: PloS One
https://www.readbyqxmd.com/read/29771932/a-multi-center-preclinical-study-of-gadoxetate-dce-mri-in-rats-as-a-biomarker-of-drug-induced-inhibition-of-liver-transporter-function
#16
Anastassia Karageorgis, Stephen C Lenhard, Brittany Yerby, Mikael F Forsgren, Serguei Liachenko, Edvin Johansson, Mark A Pilling, Richard A Peterson, Xi Yang, Dominic P Williams, Sharon E Ungersma, Ryan E Morgan, Kim L R Brouwer, Beat M Jucker, Paul D Hockings
Drug-induced liver injury (DILI) is a leading cause of acute liver failure and transplantation. DILI can be the result of impaired hepatobiliary transporters, with altered bile formation, flow, and subsequent cholestasis. We used gadoxetate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), combined with pharmacokinetic modelling, to measure hepatobiliary transporter function in vivo in rats. The sensitivity and robustness of the method was tested by evaluating the effect of a clinical dose of the antibiotic rifampicin in four different preclinical imaging centers...
2018: PloS One
https://www.readbyqxmd.com/read/29771727/modeling-gadoxetate-liver-uptake-and-efflux-using-dynamic-contrast-enhanced-magnetic-resonance-imaging-enables-preclinical-quantification-of-transporter-drug-drug-interactions
#17
Leonidas Georgiou, Jeffrey Penny, Glynis Nicholls, Neil Woodhouse, François-Xavier Blé, Josephine H Naish, Penny L Hubbard Cristinacce
OBJECTIVES: The aim of this study was to model the in vivo transporter-mediated uptake and efflux of the hepatobiliary contrast agent gadoxetate in the liver. The efficacy of the proposed technique was assessed for its ability to provide quantitative insights into drug-drug interactions (DDIs), using rifampicin as inhibitor. MATERIALS AND METHODS: Three groups of C57 mice were scanned twice with a dynamic gadoxetate-enhanced magnetic resonance imaging protocol, using a 3-dimensional spoiled gradient-echo sequence for approximately 72 minutes...
May 15, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/29771534/nitroxyl-modified-tobacco-mosaic-virus-as-a-metal-free-high-relaxivity-mri-and-epr-active-superoxide-sensor
#18
Madushani Dharmarwardana, Andre F Martins, Zhuo Chen, Philip Palacios, Chance M Nowak, Raymond P Welch, Shaobo Li, Michael Andrew Luzuriaga, Leonidas Bleris, Brad S Pierce, A Dean Sherry, Jeremiah J Gassensmith
Superoxide overproduction is known to occur in multiple disease states requiring critical care yet non-invasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by "click conjugating" paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced in vivo to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species-in particular superoxide-and are largely unaffected by peroxides and molecular oxygen...
May 17, 2018: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/29771468/interaction-between-cyanine-dye-ir-783-and-polystyrene-nanoparticles-in-solution
#19
Yunzhi Zhang, Hui Xu, Leah B Casabianca
The interactions between small molecule drugs or dyes and nanoparticles are important to the use of nanoparticles in medicine. Noncovalent adsorption of dyes on nanoparticle surfaces is also important to the development of nanoparticle dual-use imaging contrast agents. In the present work, solution-state NMR is used to examine the noncovalent interaction between a near-infrared cyanine dye and the surface of polystyrene nanoparticles in solution. Using 1D proton NMR, we can approximate the number of dye molecules that associate with each nanoparticle for different sized nanoparticles...
May 17, 2018: Magnetic Resonance in Chemistry: MRC
https://www.readbyqxmd.com/read/29770979/caesium-for-perovskite-solar-cells-an-overview
#20
Federico Bella, Polyssena Renzi, Carmen Cavallo, Claudio Gerbaldi
Perovskite solar cells have the potential to revolutionize the world of photovoltaics, and their efficiency close to 23% on a lab-scale recently certified this novel technology as the one with the most rapidly raising performance per year in the whole story of solar cells. With the aim of improving stability, reproducibility and spectral properties of the devices, in the last three years the scientific community strongly focused on Cs-doping for hybrid (typically, organolead) perovskites. In parallel, in order to further contrast hygroscopicity and reach thermal stability, research has also been carried out to achieve the development of all-inorganic perovskites based on caesium, the performances of which are actually rapidly increasing...
May 17, 2018: Chemistry: a European Journal
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