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https://www.readbyqxmd.com/read/28820941/a-photoactivatable-probe-for-super-resolution-imaging-of-enzymatic-activity-in-live-cells
#1
Elias A Halabi, Zacharias Thiel, Nils Trapp, Dorothea Pinotsi, Pablo Rivera-Fuentes
A dual-activatable, fluorogenic probe was developed to sense esterase activity with single-molecule resolution. Without enzymatic pre-activation, the diazoindanone-based probe has an electron poor core and, upon irradiation, undergoes Wolff rearrangement to give a ring-expanded xanthene core that is non-emissive. If the probe is pre-activated by carboxylesterases, the tricyclic core becomes electron-rich and the photoinduced Wolff rearrangement produces a highly emissive rhodol dye. Live-cell and solution studies confirmed the selectivity of the probe and revealed that the photoactivated dye does not diffuse away from the original location of activation because the intermediate ketene forms a covalent bond with surrounding macromolecules...
August 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28820864/diffusion-kurtosis-imaging-and-pathology-in-spinal-cord-ischemia-reperfusion-injury-in-rabbits-a-case-control-study
#2
Daowei Li, Xiaoming Wang
BACKGROUND The aim of this study was to evaluate the application of diffusion kurtosis imaging (DKI) in spinal cord ischemia/reperfusion (SCI/R) injury and to explore its association with pathology. MATERIAL AND METHODS Japanese male long-eared rabbits were chosen and divided into 7 groups (8 rabbits in each group): control group (C group), sham-operation control group (S group), and 5 experimental groups (E-2 h group, E-24 h group, E-48 h group, E-7 d group, and E-14 d group). Tarlov scoring and immunohistochemical staining were used to assess hindlimb motor function and observe the expression of glial fiber acidic protein (GFAP), respectively...
August 18, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28820625/multimodal-image-analysis-of-the-retina-in-hunter-syndrome-mucopolysaccharidosis-type-ii-case-report
#3
Isadora Darriba Macedo Salvucci, Simone Finzi, Maria Kiyoko Oyamada, Chong Ae Kim, Sérgio Luis Gianotti Pimentel
INTRODUCTION: We report a case of retinal and posterior ocular findings in a 33-year-old man diagnosed with Hunter syndrome (Mucopolysaccharidosis type II) in a multimodal imaging way. CASE PRESENTATION: Our patient was complaining of blurred night vision for the past 3 years. He had not received any systemic treatment for Hunter syndrome. Vision acuity was 20/20 in both eyes and corneas were clear. Fundus examination revealed bilateral crowded and hyperemic optic nerve heads (elevated in the ocular ultrasound) and areas of subretinal hypopigmentation...
August 18, 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28820624/retinopathy-and-optic-atrophy-expanding-the-phenotypic-spectrum-of-pathogenic-variants-in-the-aars2-gene
#4
Jason H Peragallo, Stephanie Keller, Marjo S van der Knaap, Bruno P Soares, Suma P Shankar
BACKGROUND: Optic atrophy may be the sequela of optic nerve injury due to any insult, including isolated and syndromic genetic diseases. Alanyl-tRNA synthetase 2 (AARS2) pathogenic variants have been reported to cause leukodystrophy with ovarian failure, and cardiomyopathy (#615889) as well as combined oxidative phosphorylation deficiency-8 (#614096). We report a young child who presented with decreased vision due to optic atrophy and was found to harbor missense variants in the AARS2 gene expanding the phenotypic expression of the AARS2 gene...
August 18, 2017: Ophthalmic Genetics
https://www.readbyqxmd.com/read/28820547/incidence-and-clinical-impact-of-cerebral-lesions-after-the-mitraclip%C3%A3-%C3%A2-procedure
#5
Sebastian Barth, Karsten Hamm, Stefan Fodor, Wilko Reents, Sebastian Kerber, Philipp Halbfass, Martina B Hautmann, Bernhard Schieffer, Hassan Soda
BACKGROUND: Clinically silent brain injury detected with cerebral magnetic resonance imaging (MRI) is well known after various cardiovascular interventions. Thus far, only one study has examined the periprocedural risk of cerebral ischemic events in patients undergoing percutaneous mitral valve reconstruction. The study aim was to examine the incidence and clinical impact of cerebral embolic events in patients undergoing percutaneous mitral valve reconstruction using the MitraClip® system...
March 2017: Journal of Heart Valve Disease
https://www.readbyqxmd.com/read/28820526/silica-nanoparticle-monolayers-on-a-macroion-modified-surface-formation-mechanism-and-stability
#6
M Morga, Z Adamczyk, D Kosior
Even though silica nanoparticles and their monolayers find a broad field of applications, only a few studies providing a quantitative description of silica nanoparticle deposition at solid/liquid interfaces have been reported in the literature. Given the deficit of reliable experimental data, the goal of this work is to acquire thorough physicochemical characteristics of amorphous silica nanoparticle deposition. Silica nanoparticle monolayers of controlled coverage were formed on macroion (PAH)-modified mica...
August 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28819924/dynamic-imaging-of-mitochondrial-membrane-proteins-in-specific-sub-organelle-membrane-locations
#7
REVIEW
Timo Appelhans, Karin B Busch
Mitochondria are cellular organelles with multifaceted tasks and thus composed of different sub-compartments. The inner mitochondrial membrane especially has a complex nano-architecture with cristae protruding into the matrix. Related to their function, the localization of mitochondrial membrane proteins is more or less restricted to specific sub-compartments. In contrast, it can be assumed that membrane proteins per se diffuse unimpeded through continuous membranes. Fluorescence recovery after photobleaching is a versatile technology used in mobility analyses to determine the mobile fraction of proteins, but it cannot provide data on subpopulations or on confined diffusion behavior...
August 17, 2017: Biophysical Reviews
https://www.readbyqxmd.com/read/28819863/effects-of-testosterone-treatment-on-hypothalamic-neuroplasticity-in-female-to-male-transgender-individuals
#8
Georg S Kranz, Andreas Hahn, Ulrike Kaufmann, Martin Tik, Sebastian Ganger, René Seiger, Allan Hummer, Christian Windischberger, Siegfried Kasper, Rupert Lanzenberger
Diffusion-weighted imaging (DWI) is used to measure gray matter tissue density and white matter fiber organization/directionality. Recent studies show that DWI also allows for assessing neuroplastic adaptations in the human hypothalamus. To this end, we investigated a potential influence of testosterone replacement therapy on hypothalamic microstructure in female-to-male (FtM) transgender individuals. 25 FtMs were measured at baseline, 4 weeks, and 4 months past treatment start and compared to 25 female and male controls...
August 17, 2017: Brain Structure & Function
https://www.readbyqxmd.com/read/28819296/intravoxel-incoherent-motion-diffusion-weighted-imaging-for-discriminating-the-pathological-response-to-neoadjuvant-chemoradiotherapy-in-locally-advanced-rectal-cancer
#9
Wen Lu, Hou Jing, Zhou Ju-Mei, Nie Shao-Lin, Cao Fang, Yu Xiao-Ping, Lu Qiang, Zeng Biao, Zhu Su-Yu, Hu Ying
To investigate the usefulness of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) in discriminating the pathological complete response (pCR) to neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC), 42 patients underwent preoperative IVIM-DWI before (pre-nCRT) and after nCRT (post-nCRT). The values of pre-nCRT and post-nCRT IVIM-DWI parameters (ADC, D, D* and f), together with the percentage changes (∆% parametric value) induced by nCRT, were compared between the pCR (tumour regression grade [TRG] 4) and non-pCR (TRG 0, 1, 2 or 3) groups and between the GR (TRG 3 or 4) and PR (TRG 0, 1 or 2) groups based on the Dworak TRG system...
August 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28819085/histological-grading-of-hepatocellular-carcinomas-with-intravoxel-incoherent-motion-diffusion-weighted-imaging-inconsistent-results-depending-on-the-fitting-method
#10
Shintaro Ichikawa, Utaroh Motosugi, Diego Hernando, Hiroyuki Morisaka, Nobuyuki Enomoto, Masanori Matsuda, Hiroshi Onishi
PURPOSE: To compare the abilities of three intravoxel incoherent motion (IVIM) imaging approximation methods to discriminate the histological grade of hepatocellular carcinomas (HCCs). METHODS: Fifty-eight patients (60 HCCs) underwent IVIM imaging with 11 b-values (0-1000 s/mm(2)). Slow (D) and fast diffusion coefficients (D(*)) and the perfusion fraction (f) were calculated for the HCCs using the mean signal intensities in regions of interest drawn by two radiologists...
August 16, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28818988/multiregional-tumor-drug-uptake-imaging-by-pet-and-microvascular-morphology-in-end-stage-diffuse-intrinsic-pontine-glioma
#11
Sophie E M Veldhuijzen van Zanten, A Charlotte P Sewing, Arthur van Lingen, Otto S Hoekstra, Pieter Wesseling, Michaël H Meel, Dannis G van Vuurden, Gertjan J L Kaspers, Esther Hulleman, Marianna Bugiani
Inadequate tumor uptake of the vascular endothelial growth factor (VEGF) antibody bevacizumab could explain lack of effect in diffuse intrinsic pontine glioma (DIPG). Methods: By combining data from a positron emission tomography (PET) imaging study using zirconium-89((89)Zr)-labeled bevacizumab and an autopsy study, a 1-on-1 analysis of multiregional in vivo and ex vivo (89)Zr-bevacizumab uptake, tumor histology and vascular morphology in a DIPG patient was performed. Results: In vivo (89)Zr-bevacizumab measurements showed heterogeneity between lesions...
August 17, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28818826/test-retest-and-interreader-reproducibility-of-semiautomated-atlas-based-analysis-of-diffusion-tensor-imaging-data-in-acute-cervical-spine-trauma-in-adult-patients
#12
D J Peterson, A M Rutman, D S Hippe, J G Jarvik, F H Chokshi, M R Reyes, C H Bombardier, M Mossa-Basha
BACKGROUND AND PURPOSE: DTI is a tool for microstructural spinal cord injury evaluation. This study evaluated the reproducibility of a semiautomated segmentation algorithm of spinal cord DTI. MATERIALS AND METHODS: Forty-two consecutive patients undergoing acute trauma cervical spine MR imaging underwent 2 axial DTI scans in addition to their clinical scan. The datasets were put through a semiautomated probabilistic segmentation algorithm that selected white matter, gray matter, and 24 individual white matter tracts...
August 17, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28818116/distinct-white-matter-microstructural-abnormalities-and-extracellular-water-increases-relate-to-cognitive-impairment-in-alzheimer-s-disease-with-and-without-cerebrovascular-disease
#13
Fang Ji, Ofer Pasternak, Siwei Liu, Yng Miin Loke, Boon Linn Choo, Saima Hilal, Xin Xu, Mohammad Kamran Ikram, Narayanaswamy Venketasubramanian, Christopher Li-Hsian Chen, Juan Zhou
BACKGROUND: Mixed vascular and neurodegenerative dementia, such as Alzheimer's disease (AD) with concomitant cerebrovascular disease, has emerged as the leading cause of age-related cognitive impairment. The brain white matter (WM) microstructural changes in neurodegeneration well-documented by diffusion tensor imaging (DTI) can originate from brain tissue or extracellular free water changes. The differential microstructural and free water changes in AD with and without cerebrovascular disease, especially in normal-appearing WM, remain largely unknown...
August 17, 2017: Alzheimer's Research & Therapy
https://www.readbyqxmd.com/read/28818013/relationship-between-doppler-findings-and-fetal-brain-apparent-diffusion-coefficient-in-early-onset-intra-uterine-growth-restriction
#14
Mehmet Serdar Kutuk, Murside Sahin, Sureyya Burcu Gorkem, Selim Doganay, Ahmet Ozturk
OBJECTIVE: The aim of the study is to assess the relationship between uteroplacental Doppler sonography findings and cerebral diffusion measured by diffusion-weighted magnetic resonance imaging (DWI) in fetuses with early- onset intrauterine growth restriction (IUGR). MATERIAL AND METHODS: The study included 54 pregnant women with fetal IUGR and 15 healthy controls (n: 15). Fetuses with IUGR were classified into 4 groups based on Doppler findings: group 1 (n = 12), umbilical artery (UA) pulsatility index (PI) >95pc; group 2 (n = 11), UA PI > 95 pc and middle cerebral artery PI <5pc; group 3 (n = 21), absent end-diastolic (A-EDF) in UA; group 4 (n = 10), reversed EDF in UA...
August 17, 2017: Journal of Maternal-fetal & Neonatal Medicine
https://www.readbyqxmd.com/read/28817878/re-diagnostic-performance-of-diffusion-weighted-magnetic-resonance-imaging-in-differentiating-human-renal-lesions-benignity-or-malignancy-a%C3%A2-meta-analysis
#15
https://www.readbyqxmd.com/read/28817577/detailing-neuroanatomical-development-in-late-childhood-and-early-adolescence-using-noddi
#16
Alyssa Mah, Bryce Geeraert, Catherine Lebel
Diffusion tensor imaging (DTI) studies have provided much evidence of white and subcortical gray matter changes during late childhood and early adolescence that suggest increasing myelination, axon density, and/or fiber coherence. Neurite orientation dispersion and density imaging (NODDI) can be used to further characterize development in white and subcortical grey matter regions in the brain by improving specificity of the MRI signal compared to conventional DTI. We used measures from NODDI and DTI to examine white and subcortical gray matter development in a group of 27 healthy participants aged 8-13 years...
2017: PloS One
https://www.readbyqxmd.com/read/28817574/diffusion-tensor-imaging-profiles-reveal-specific-neural-tract-distortion-in-normal-pressure-hydrocephalus
#17
Nicole C Keong, Alonso Pena, Stephen J Price, Marek Czosnyka, Zofia Czosnyka, Elise E DeVito, Charlotte R Housden, Barbara J Sahakian, John D Pickard
BACKGROUND: The pathogenesis of normal pressure hydrocephalus (NPH) remains unclear which limits both early diagnosis and prognostication. The responsiveness to intervention of differing, complex and concurrent injury patterns on imaging have not been well-characterized. We used diffusion tensor imaging (DTI) to explore the topography and reversibility of white matter injury in NPH pre- and early after shunting. METHODS: Twenty-five participants (sixteen NPH patients and nine healthy controls) underwent DTI, pre-operatively and at two weeks post-intervention in patients...
2017: PloS One
https://www.readbyqxmd.com/read/28817196/technical-note-quantitative-analysis-of-ivim-diffusion-mri-using-total-variation-and-huber-penalty-function
#18
Esha Baidya Kayal, Devasenathipathy Kandasamy, Kedar Khare, Jayendra Tiru Alampally, Sameer Bakhshi, Raju Sharma, Amit Mehndiratta
PURPOSE: Quantitative analysis in Intra-voxel Incoherent Motion (IVIM) imaging commonly uses voxel-wise estimation of the bi-exponential model, which might not be reliable for clinical interpretation. Improving model fitting performance and qualitative and quantitative parametric estimation, two novel methodologies are proposed here. METHODS: Five IVIM analyses methodologies: i) Bi-Exponential (BE) model, ii) Segmented BE method with 2-parameter fitting (BEseg-2), iii) Segmented BE method with 1-parameter fitting (BEseg-1), iv) BE with adaptive Total Variation Penalty function (BE+TV) and v) BE with adaptive Huber Penalty function (BE+HPF) were evaluated...
August 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28816952/prediction-of-microvascular-invasion-of-hepatocellular-carcinoma-with-preoperative-diffusion-weighted-imaging-a-comparison-of-mean-and-minimum-apparent-diffusion-coefficient-values
#19
Jinkun Zhao, Xubin Li, Kun Zhang, Xiaoyu Yin, Xiangfu Meng, Lizhu Han, Xuening Zhang
The aim of the study was to investigate the value of preoperative diffusion-weighted imaging (DWI) in predicting microvascular invasion (MVI) of hepatocellular carcinoma (HCC), using and comparing mean and minimum apparent diffusion coefficient (ADC) values.Preoperative MR images of 318 patients with HCC confirmed by surgical pathology were retrospectively analyzed. All patients underwent preoperative DWI on a 1.5 Tesla MRI scanner. The mean and minimum ADC values of the tumors were measured. Interobserver agreements were assessed by the intraclass correlation coefficient (ICC)...
August 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28816772/a-case-of-lenticulostriate-stroke-due-to-minor-closed-head-injury-in-a-2-year-old-child-role-of-mineralizing-angiopathy
#20
Emin Fidan, Dana D Cummings, Mioara D Manole
OBJECTIVE: Cerebral infarction due to minor head injury is rare. Mineralizing angiopathy is considered a predisposing factor for lenticulostriate stroke after minor closed head injury. This entity is characterized by infarction of the basal ganglia and most often occurs in young children, from infancy to 2 years of age. Symptoms usually occur immediately after the injury. METHODS AND RESULTS: We present the case of a previously healthy 2-year-old female child presenting with right facial hemiparesis and aphasia, along with right arm and leg weakness that occurred immediately after a fall from the couch onto a carpeted floor...
July 3, 2017: Pediatric Emergency Care
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