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Hypoxia Imaging

Eriko Seo, Toshiyuki Sazi, Morio Togawa, Osamu Nagata, Masataka Murakami, Shigeaki Kojima, Yoshiteru Seo
Infrared photoplethysmogram (IR-PPG) and magnetic resonance image (MRI) of the Mytilus galloprovincialis heart were obtained simultaneously. Heart rate was varied by changing temperature, aerial exposure and hypoxia. Higher heart rates (35-20 beat min(-1)) were usually observed at 20°C under the aerobic condition, typical IR-PPG represented a single peak (peak v). The upward and downward slopes of the peak v corresponded to the filling and contraction of the ventricle, respectively. A double-peak IR-PPG was observed in a wide range of heart rates (35 to 5 beats min(-1)) under various conditions...
October 19, 2016: Biology Open
Francisco Molina, María Luisa Del Moral, María Ángeles Peinado, Alma Rus
BACKGROUND: Nitric oxide (NO) appears to play a key role in the hypoxic injury to the brain. We have previously reported that hypoxia/reoxygenation downregulated NO synthases (NOS) in the adult striatum. Until now, no data were available concerning the influence of aging in conjunction with hypoxia/reoxygenation on the NO system in the striatum. OBJECTIVE: The aim of this study was to assess the role of the NO pathway in the hypoxic aged striatum. METHODS: Wistar rats 24-25 months old were submitted to hypobaric hypoxia (20 min)/reoxygenation (0 h, 24 h, 5 days)...
October 20, 2016: Gerontology
Edem Dovlo, Bahman Lashkari, Sung Soo Sean Choi, Andreas Mandelis, Wei Shi, Fei-Fei Liu
Overcoming the limitations of conventional linear spectroscopy used in multispectral photoacoustic imaging, wherein a linear relationship is assumed between the absorbed optical energy and the absorption spectra of the chromophore at a specific location, is crucial for obtaining accurate spatially-resolved quantitative functional information by exploiting known chromophore-specific spectral characteristics. This study introduces a non-invasive phase-filtered differential photoacoustic technique, wavelength-modulated differential photoacoustic radar (WM-DPAR) imaging that addresses this issue by eliminating the effect of the unknown wavelength-dependent fluence...
October 19, 2016: Journal of Biophotonics
Yuen Ting Lam, Laura Lecce, Joanne T M Tan, Christina A Bursill, David J Handelsman, Martin K C Ng
Increasing evidence indicates that androgens regulate ischemia-induced neovascularization. However, the role of genomic androgen action mediated by androgen receptor (AR), a ligand-activated nuclear transcription factor, remains poorly understood. Using an AR knockout mouse strain that contains a transcriptionally inactive AR (AR(Δex3)KO), we examined the role of AR genomic function in modulating androgen-mediated augmentation of ischemia-induced neovascularization. Castrated wildtype (AR(WT)) and AR(Δex3)KO mice were implanted with dihydrotestosterone (DHT) or placebo pellets following hindlimb ischemia (HLI)...
October 18, 2016: Endocrinology
Marc Auerbach, Joanne Cole, Pina Violano, Linda Roney, Catherine Doherty, Michael Shepherd, Ralph MacKinnon
OBJECTIVES: Thousands of head-injured children are cared for by interprofessional teams in emergency departments every day. Teams must balance performing time-consuming interventions with safe transport for neuroimaging. This study aims to describe and compare providers' perspectives on the transfer of head-injured children to neuroimaging and factors contributing to delays. METHODS: Participants were interprofessional health care providers involved in the care of head-injured children at sites in the United Kingdom, the United States, and New Zealand...
October 8, 2016: Pediatric Emergency Care
Pratik Naik, Laura Cashin, Sonny Huitron
Foreign body granulomatosis is a rare complication of intravenous injection of pulverized oral prescription tablets. We present the case of an active duty male who was ultimately diagnosed with foreign body granulomatosis caused by the crushing and intravenous injection of acetaminophen with oxycodone (Percocet). The 24-year-old patient initially presented with multiple syncopal episodes, hemoptysis and hypoxia. The patient presentation and imaging findings involved in foreign body granulomatosis can mimic many pulmonary disorders and can be widely variable...
October 2016: Military Medicine
Takuya Toyonaga, Shigeru Yamaguchi, Kenji Hirata, Kentaro Kobayashi, Osamu Manabe, Shiro Watanabe, Shunsuke Terasaka, Hiroyuki Kobayashi, Naoya Hattori, Tohru Shiga, Yuji Kuge, Shinya Tanaka, Yoichi M Ito, Nagara Tamaki
PURPOSE: Metabolic activity and hypoxia are both important factors characterizing tumor aggressiveness. Here, we used F-18 fluoromisonidazole (FMISO) and F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) to define metabolically active hypoxic volume, and investigate its clinical significance in relation to progression free survival (PFS) and overall survival (OS) in glioblastoma patients. EXPERIMENTAL DESIGN: Glioblastoma patients (n = 32) underwent FMISO PET, FDG PET, and magnetic resonance imaging (MRI) before surgical intervention...
October 18, 2016: European Journal of Nuclear Medicine and Molecular Imaging
Ashley M Stokes, Charles P Hart, C Chad Quarles
High-grade gliomas are often characterized by hypoxia, which is associated with both poor long-term prognosis and therapy resistance. The adverse role hypoxia plays in treatment resistance and disease progression has led to the development of hypoxia imaging methods and hypoxia-targeted treatments. Here, we determined the tumor hypoxia and vascular perfusion characteristics of 2 rat orthotopic glioma models using 18-fluoromisonidozole positron emission tomography. In addition, we determined tumor response to the hypoxia-activated prodrug evofosfamide (TH-302) in these rat glioma models...
September 2016: Tomography: a Journal for Imaging Research
Qing Zhang, Qing Zhang, Yanxing Guan, Shaozheng Liu, Qingjie Chen, Xiangmin Li
BACKGROUND This study was specifically designed to develop a new 99mTc compound with 3-amino-4-[2-(2-methyl-5-nitro-1H-imidazol)-ethylamino]-4-oxo-butyrate (5-ntm-asp) and to verify whether this compound is feasible to be a radiopharmaceutical for hypoxic tumors. MATERIAL AND METHODS Metronidazole derivative 5-ntm-asp was synthesized and then radio-labeled by Na [99mTcO4], forming 99mTc-5-ntm-asp. Another two complexes of 99mTc-2- and 99mTc-5-nitroimidazole-iminodiacetic acid (99mTc-2-ntm-IDA and 99mTc-5-ntm-IDA) were also synthesized based on previous studies...
October 18, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Yong Li, Xu Wang, Jie Yang, Xilei Xie, Mengmeng Li, Jinye Niu, Lili Tong, Bo Tang
Carbon monoxide (CO), a crucial gas message molecule, plays an important role in the regulation of physiological and pathological process. Hypoxia-induced CO is involved in modulating various cellular activities, including signal transduction, proliferation, and apoptosis. However, tracking CO fluctuation in the hypoxic cells is still a challenge due to lack of straight forward, visualized and non-invasive tools. In this work, based on metal palladium-catalyzed reaction, we present the rational design, synthesis and biological utility of an azobenzene-cyclopalladium-based fluorescent probe, ACP-2, for CO monitoring...
October 17, 2016: Analytical Chemistry
Edward Gilbert-Kawai, Jonny Coppel, Hennis Phillip, Michael Grocott, Can Ince, Daniel Martin
Present knowledge of how the microcirculation is altered by prolonged exposure to hypoxia at high altitude is incomplete and modification of existing analytical techniques may improve our knowledge considerably. We set out to use a novel simplified method of measuring in vivo capillary density during an expedition to high altitude using a CytoCam incident dark field imaging video-microscope. The simplified method of data capture involved recording one-second images of the mucosal surface of the inner lip to reveal data about microvasculature density in ten individuals...
2016: F1000Research
Samata Kakkad, Jiangyang Zhang, Alireza Akhbardeh, Desmond Jacob, Balaji Krishnamachary, Meiyappan Solaiyappan, Michael A Jacobs, Venu Raman, Dieter Leibfritz, Kristine Glunde, Zaver M Bhujwalla
Collagen 1 (Col1) fibers play an important role in tumor interstitial macromolecular transport and cancer cell dissemination. Our goal was to understand the influence of Col1 fibers on water diffusion, and to examine the potential of using noninvasive diffusion tensor imaging (DTI) to indirectly detect Col1 fibers in breast lesions. We previously observed, in human MDA-MB-231 breast cancer xenografts engineered to fluoresce under hypoxia, relatively low amounts of Col1 fibers in fluorescent hypoxic regions...
October 2016: Neoplasia: An International Journal for Oncology Research
Benedikt Wiestler, Anne Kluge, Mathias Lukas, Jens Gempt, Florian Ringel, Jürgen Schlegel, Bernhard Meyer, Claus Zimmer, Stefan Förster, Thomas Pyka, Christine Preibisch
Non-invasive, imaging-based examination of glioma biology has received increasing attention in the past couple of years. To this end, the development and refinement of novel MRI techniques, reflecting underlying oncogenic processes such as hypoxia or angiogenesis, has greatly benefitted this research area. We have recently established a novel BOLD (blood oxygenation level dependent) based MRI method for the measurement of relative oxygen extraction fraction (rOEF) in glioma patients. In a set of 37 patients with newly diagnosed glioma, we assessed the performance of a machine learning model based on multiple MRI modalities including rOEF and perfusion imaging to predict WHO grade...
October 14, 2016: Scientific Reports
Bryn Putbrese, Anne Kennedy
Ventriculomegaly (VM) is a nonspecific finding on fetal imaging. Identification of the specific etiology is important as it affects prognosis and may even change the course of current or future pregnancies. In this review we will focus on the application of fetal MRI to demonstrate intracranial hemorrhage (ICH) and ischemic brain injury as opposed to other causes of VM. MRI is able to identify the specific etiology of ventriculomegaly with much more sensitivity and specificity than ultrasound and should be considered whenever VM is identified on obstetric ultrasound...
October 13, 2016: British Journal of Radiology
Chung-Wein Lee, Keith M Stantz
BACKGROUND: Tumor hypoxia is involved in every stage of solid tumor development: formation, progression, metastasis, and apoptosis. Two types of hypoxia exist in tumors-chronic hypoxia and acute hypoxia. Recent studies indicate that the regional hypoxia kinetics is closely linked to metastasis and therapeutic responses, but regional hypoxia kinetics is hard to measure. We propose a novel approach to determine the local pO2 by fusing the parameters obtained from in vivo functional imaging through the use of a modified multivariate Krogh model...
October 12, 2016: Biomedical Engineering Online
Xiaobo Zhou, Hua Liang, Pengfei Jiang, Kenneth Yin Zhang, Shujuan Liu, Tianshe Yang, Qiang Zhao, Lijuan Yang, Wen Lv, Qi Yu, Wei Huang
Molecular oxygen (O2) plays a key role in many physiological processes, and becomes a toxicant to kill cells when excited to (1)O2. Intracellular O2 levels, or the degree of hypoxia, are always viewed as an indicator of cancers. Due to the highly efficient cancer therapy ability and low side effect, photodynamic therapy (PDT) becomes one of the most promising treatments for cancers. Herein, an early-stage diagnosis and therapy system is reported based on the phosphorescent conjugated polymer dots (Pdots) containing Pt(II) porphyrin as an oxygen-responsive phosphorescent group and (1)O2 photosensitizer...
February 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Owen J Arthurs, A Rega, F Guimiot, N Belarbi, J Rosenblatt, V Biran, M Elmaleh, G Sebag, M Alison
OBJECTIVES: Diffusion weighted magnetic resonance imaging (DWI) is a sensitive method to assess brain maturation or detect brain lesions, providing Apparent Diffusion Coefficient (ADC) values as a measure of water diffusion. Abnormal ADC values are seen in ischemic brain lesions, such as acute or chronic hypoxia. The aim of this study was to assess whether ADC values in the fetal brain were different in a group of fetuses exposed to severe vascular intrauterine growth restriction, compared to normal controls...
October 5, 2016: Ultrasound in Obstetrics & Gynecology
Bilge Öztoprak
OBJECTIVES: Clinical applications of susceptibility-weighted imaging (SWI) are increasing steadily. The aim of this study is to investigate the appearance of cerebral veins on SWI, which is very sensitive to the deoxyhaemoglobin level in vessels, in pulmonary embolism (PE). METHODS: The cranial SWI images of 19 patients with PE and 22 controls from September 2013 through March 2016 were retrospectively examined for the presence of prominent cerebral veins. MRI findings were correlated with blood oxygen levels...
October 4, 2016: European Radiology
Samuel Valable, Aurélien Corroyer-Dulmont, Ararat Chakhoyan, Lucile Durand, Jérôme Toutain, Didier Divoux, Louisa Barré, Eric T MacKenzie, Edwige Petit, Myriam Bernaudin, Omar Touzani, Emmanuel L Barbier
The partial pressure in oxygen remains challenging to map in the brain. Two main strategies exist to obtain surrogate measures of tissue oxygenation: the tissue saturation studied by magnetic resonance imaging (StO2-MRI) and the identification of hypoxia by a positron emission tomography (PET) biomarker with 3-[(18)F]fluoro-1-(2-nitro-1-imidazolyl)-2-propanol ([(18)F]-FMISO) as the leading radiopharmaceutical. Nonetheless, a formal validation of StO2-MRI against FMISO-PET has not been performed. The objective of our studies was to compare the two approaches in (a) the normal rat brain when the rats were submitted to hypoxemia; (b) animals implanted with four tumour types differentiated by their oxygenation...
October 4, 2016: Journal of Cerebral Blood Flow and Metabolism
Xiao Bao, Ming-Wei Wang, Jian-Min Luo, Si-Yang Wang, Yong-Ping Zhang, Ying-Jian Zhang
Objective: Antiangiogenesis therapy (AAT) has provided substantial benefits regarding improved outcomes and survival for suitable patients in clinical settings. Therefore, the early definition of therapeutic effects is urgently needed to guide cancer AAT. We aimed to optimize the early response monitoring and prediction of AAT efficacy, as indicated by the multi-targeted anti-angiogenic drug sunitinib in U87MG tumors, using noninvasive positron emission computed tomography (PET) molecular imaging strategies of multifactorial bioparameters...
2016: Theranostics
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