This paper describes a study performed to evaluate the feasibility of using a 1.5-T whole-body magnetic resonance imaging (MRI) equipment, in combination with pharmacokinetic modeling, to obtain in vivo information about the morphology and perfusion of tarantulas (Eurypelma californicum). MRI was performed on three tarantulas using spin-echo sequences for morphological imaging and a rapid spoiled gradient-echo sequence for dynamic imaging during and after contrast medium (CM; Gd-DTPA) injection. Signal enhancement in dynamic measurements was evaluated with a pharmacokinetic two-compartment model. Spin-echo images showed morphological structures well. Dynamic images were of sufficient quality and allowed a model analysis of CM kinetics, which provides information about regional perfusion. In conclusion, morphological and dynamic contrast-enhanced MRI of tarantulas is feasible with a conventional clinical scanner. Studies of this kind are therefore possible without a dedicated high-field animal scanner.
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http://dx.doi.org/10.1016/j.mri.2006.08.019 | DOI Listing |
J Am Chem Soc
July 2023
Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, United States.
We report an innovative approach to producing bacteriochlorins (bacs) via formal cycloaddition by subjecting a porphyrin to a trimolecular reaction. Bacs are near-infrared probes with the intrinsic ability to serve in multimodal imaging. However, despite their ability to fluoresce and chelate metal ions, existing bacs have thus offered limited ability to label biomolecules for target specificity or have lacked chemical purity, limiting their use in bio-imaging.
View Article and Find Full Text PDFLancet Psychiatry
November 2020
Institute for the Developing Mind, Children's Hospital Los Angeles, Los Angeles, CA, USA; Department of Psychiatry, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
Background: Exposure therapy is the treatment of choice for anxiety disorders but requires people to confront feared situations and can be distressing. We tested the hypothesis that exposure without conscious awareness would reduce fear in participants with specific phobia by harnessing the neural circuitry supporting the automatic extinction of fear.
Methods: In this single-centre, randomised controlled experiment, we recruited women aged 18-29 years from an ethnically diverse, community-based population in northeastern USA, between Sept 1, 2013, and Aug 1, 2016.
Hum Brain Mapp
May 2017
Children's Hospital Los Angeles & Keck School of Medicine, University of Southern California, Los Angeles, California.
Research on automatic processes in fear has emphasized the provocation of fear responses rather than their attenuation. We have previously shown that the repeated presentation of feared images without conscious awareness via backward masking reduces avoidance of a live tarantula in spider-phobic participants. Herein we investigated the neural basis for these adaptive effects of masked exposure.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2010
Medical Research Council-Cognition and Brain Sciences Unit, Cambridge CB2 7EF, United Kingdom.
Phylogenetic threats such as spiders evoke our deepest primitive fears. When close or looming, such threats engage evolutionarily conserved monitoring systems and defense reactions that promote self-preservation. With the use of a modified behavioral approach task within functional MRI, we show that, as a tarantula was placed closer to a subject's foot, increased experiences of fear coincided with augmented activity in a cascade of fear-related brain networks including the periaqueductal gray, amygdala, and bed nucleus of the stria terminalis.
View Article and Find Full Text PDFMagn Reson Imaging
January 2007
Section of Medical Physics, Department of Diagnostic and Interventional Radiology, Johannes Gutenberg University Hospital, 55131 Mainz, Germany.
This paper describes a study performed to evaluate the feasibility of using a 1.5-T whole-body magnetic resonance imaging (MRI) equipment, in combination with pharmacokinetic modeling, to obtain in vivo information about the morphology and perfusion of tarantulas (Eurypelma californicum). MRI was performed on three tarantulas using spin-echo sequences for morphological imaging and a rapid spoiled gradient-echo sequence for dynamic imaging during and after contrast medium (CM; Gd-DTPA) injection.
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