Browsing by Subject "Lipid"

Now showing 1 - 6 of 6
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    Bond-selective photoacoustic imaging by converting molecular vibration into acoustic waves
    (Elsevier, 2016-03) Hui, Jie; Li, Rui; Phillips, Evan H.; Goergen, Craig J.; Sturek, Michael; Cheng, Ji-Xin; Department of Cellular & Integrative Physiology, IU School of Medicine
    The quantized vibration of chemical bonds provides a way of detecting specific molecules in a complex tissue environment. Unlike pure optical methods, for which imaging depth is limited to a few hundred micrometers by significant optical scattering, photoacoustic detection of vibrational absorption breaks through the optical diffusion limit by taking advantage of diffused photons and weak acoustic scattering. Key features of this method include both high scalability of imaging depth from a few millimeters to a few centimeters and chemical bond selectivity as a novel contrast mechanism for photoacoustic imaging. Its biomedical applications spans detection of white matter loss and regeneration, assessment of breast tumor margins, and diagnosis of vulnerable atherosclerotic plaques. This review provides an overview of the recent advances made in vibration-based photoacoustic imaging and various biomedical applications enabled by this new technology.
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    Essential fatty acid deficiency in parenteral nutrition: Historical perspective and modern solutions, a narrative review
    (Wiley, 2025) Wolff, Jodi; Cober, Mary Petrea; Huff, Katie A.; Pediatrics, School of Medicine
    Essential fatty acid deficiency (EFAD) may occur in the setting of inadequate fat intake, malabsorption, malnutrition, and altered fat metabolism. Humans lack the enzymes to synthesize the essential acids linoleic acid and alpha-linolenic acid, so they must be obtained from the diet. Patients dependent on parenteral nutrition need adequate amounts of these essential fatty acids supplied in lipid injectable emulsions (ILEs). With the increasing use of multicomponent ILEs that are lower in linoleic and alpha-linolenic acid, it is imperative that clinicians understand appropriate dosing to prevent EFAD. An understanding of fatty acid composition and metabolic pathways is important, as the use of the Holman Index (triene:tetraene ratio) alone may lead to an inaccurate diagnosis of EFAD.
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    Fat-water separation by fast metabolite cycling magnetic resonance spectroscopic imaging at 3 T: A method to generate separate quantitative distribution maps of musculoskeletal lipid components
    (Wiley, 2020-09) Alhulail, Ahmad A.; Patterson, Debra A.; Xia, Pingyu; Zhou, Xiaopeng; Lin, Chen; Thomas, M. Albert; Dydak, Ulrike; Emir, Uzay E.; Radiology and Imaging Sciences, School of Medicine
    Purpose: To provide a rapid, noninvasive fat-water separation technique that allows producing quantitative maps of particular lipid components. Methods: The calf muscles in 5 healthy adolescents (age 12-16 years; body mass index = 20 ± 3 kg/m2 ) were scanned by two different fat fraction measurement methods. A density-weighted concentric-ring trajectory metabolite-cycling MRSI technique was implemented to collect data with a nominal resolution of 0.25 mL within 3 minutes and 16 seconds. For comparative purposes, the standard Dixon technique was performed. The two techniques were compared using structural similarity analysis. Additionally, the difference in the distribution of each lipid over the adolescent calf muscles was assessed based on the MRSI data. Results: The proposed MRSI technique provided individual fat fraction maps for eight musculoskeletal lipid components identified by LCModel analysis (IMC/L [CH3 ], EMCL [CH3 ], IMC/L [CH2 ]n , EMC/L [CH2 ]n , IMC/L [CH2 -CH], EMC/L [CH2 -CH], IMC/L [-CH=CH-], and EMC/L [-CH=CH-]) with mean structural similarity indices of 0.19, 0.04, 0.03, 0.50, 0.45, 0.04, 0.07, and 0.12, respectively, compared with the maps generated by the used Dixon method. Further analysis of voxels with zero structural similarity demonstrated an increased sensitivity of fat fraction lipid maps from the data acquired using this MRSI technique over the standard Dixon technique. The lipid spatial distribution over calf muscles was consistent with previously published findings in adults. Conclusion: This MRSI technique can be a useful tool when individual lipid fat fraction maps are desired within a clinically acceptable time and with a nominal spatial resolution of 0.25 mL.
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    In Vivo Renal Lipid Quantification by Accelerated Magnetic Resonance Spectroscopic Imaging at 3T: Feasibility and Reliability Study
    (MDPI, 2022-04-23) Alhulail, Ahmad A.; Servati, Mahsa; Ooms, Nathan; Akin, Oguz; Dincer, Alp; Thomas, M. Albert; Dydak, Ulrike; Emir, Uzay E.; Radiology and Imaging Sciences, School of Medicine
    A reliable and practical renal-lipid quantification and imaging method is needed. Here, the feasibility of an accelerated MRSI method to map renal fat fractions (FF) at 3T and its repeatability were investigated. A 2D density-weighted concentric-ring-trajectory MRSI was used for accelerating the acquisition of 48 × 48 voxels (each of 0.25 mL spatial resolution) without respiratory navigation implementations. The data were collected over 512 complex-FID timepoints with a 1250 Hz spectral bandwidth. The MRSI sequence was designed with a metabolite-cycling technique for lipid-water separation. The in vivo repeatability performance of the sequence was assessed by conducting a test-reposition-retest study within healthy subjects. The coefficient of variation (CV) in the estimated FF from the test-retest measurements showed a high degree of repeatability of MRSI-FF (CV = 4.3 ± 2.5%). Additionally, the matching level of the spectral signature within the same anatomical region was also investigated, and their intrasubject repeatability was also high, with a small standard deviation (8.1 ± 6.4%). The MRSI acquisition duration was ~3 min only. The proposed MRSI technique can be a reliable technique to quantify and map renal metabolites within a clinically acceptable scan time at 3T that supports the future application of this technique for the non-invasive characterization of heterogeneous renal diseases and tumors.
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    Mitochondrial Cardiolipin-Targeted Tetrapeptide, SS-31, Exerts Neuroprotective Effects Within In Vitro and In Vivo Models of Spinal Cord Injury
    (MDPI, 2025-04-02) Ravenscraft, Baylen; Lee, Do-Hun; Dai, Heqiao; Watson, Abbie Lea; Aparicio, Gabriela Inés; Han, Xianlin; Deng, Ling-Xiao; Liu, Nai-Kui; Neurological Surgery, School of Medicine
    Spinal cord injury (SCI) affects millions globally, leading to severe motor and sensory deficits with no effective clinical treatment. Cardiolipin (CL), a mitochondria-specific phospholipid, plays a critical role in bioenergetics and apoptosis. Emerging evidence suggests that CL alterations contribute to secondary SCI pathology, but their precise role and underlying mechanisms remain fully understudied. In this study, we investigated the protective effects of SS-31 on CL alteration, neuronal death, tissue damage, and behavioral recovery after SCI using both in vitro and in vivo models, lipidomics analysis, histological evaluation, and behavioral assessments. In vitro investigations used primary spinal cord neuron cultures, challenged with either rotenone or glutamatergic excitotoxicity, with protective capabilities measured via cell death assays and neurite morphological analysis. In vivo investigations used female adult C57Bl/6 mice, challenged with a contusive SCI. The results showed that SS-31 reduced rotenone- and glutamate-induced mitochondrial dysfunction and neuronal death in a dose-dependent manner in vitro. Additionally, SS-31 attenuated rotenone- and glutamate-induced neurite degeneration in vitro. Lipidomics analysis revealed a reduction in CL at 24 h post-SCI in adult mice, which was attenuated by SS-31 in a dose-dependent manner. Consistent with this effect, SS-31 improved behavioral recovery after SCI in adult mice, although it had no significant effect on tissue damage. These findings suggest that CL alteration may play a key role in the pathogenesis of SCI, at least in the C57BL/6 mouse, and as such could be an attractive therapeutic target for ameliorating secondary SCI.
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    Some aspects on the control of lipid synthesis
    (1971) Shinohara, Naomi