Publications by authors named "Candance Wong"

3 Publications

  • Page 1 of 1

Reliability of performing ultrasound derived SWE and fat fraction in adult livers.

Clin Imaging 2021 Dec 17;80:424-429. Epub 2021 Sep 17.

Rocky Vista University, Ivins, UT, USA.

Purpose: The aim of the study was to test the reproducibility of performing conventional point shear wave elastography (pSWE), auto-pSWE, and ultrasound derived fat fraction (UDFF) in adult livers.

Methods: The Institutional Review Board approved the study and all participants provided written informed consent. Conventional pSWE (obtaining 10 measurements through 10 acquisitions), auto-pSWE (automatically obtaining 15 measurements by a single acquisition), and UDFF (one measurement obtained by one acquisition) of the liver were prospectively performed in 21 participants (10 men, 11 women, mean age 63y) by senior and junior operators in February-May 2021. Shear wave velocity (SWV, m/s) of the liver was measured by conventional pSWE and auto-pSWE. Intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement were used to test intra-observer repeatability and inter-observer reproducibility in measuring pSWE, auto-pSWE, and UDFF.

Results: ICC for testing intra-observer repeatability and inter-observer reproducibility in performing pSWE, auto-pSWE, and UDFF was >0.85 (95% confidence interval 0.85-0.99). The mean difference of 95% Bland-Altman limits of agreement was -0.02 (upper 0.09, lower -0.12) and the correlation of SWV measured between conventional pSWE and auto-pSWE methods was strong (r = 0.87).

Conclusion: Our results suggest good repeatability and reproducibility in measuring UDFF and SWV in adult livers. The auto-pSWE has higher reliability, reproducibility and time efficacy in measuring SWV of adult livers when compared to conventional pSWE method.
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http://dx.doi.org/10.1016/j.clinimag.2021.08.025DOI Listing
December 2021

α-synuclein aggregates induce c-Abl activation and dopaminergic neuronal loss by a feed-forward redox stress mechanism.

Prog Neurobiol 2021 07 2;202:102070. Epub 2021 May 2.

Department of Neurology, University of California San Francisco, United States; Neurology Service, San Francisco Veterans Affairs Health Care System, United States. Electronic address:

Oxidative stress and α-synuclein aggregation both drive neurodegeneration in Parkinson's disease, and the protein kinase c-Abl provides a potential amplifying link between these pathogenic factors. Suppressing interactions between these factors may thus be a viable therapeutic approach for this disorder. To evaluate this possibility, pre-formed α-synuclein fibrils (PFFs) were used to induce α-synuclein aggregation in neuronal cultures. Exposure to PFFs induced oxidative stress and c-Abl activation in wild-type neurons. By contrast, α-synuclein - deficient neurons, which cannot form α-synuclein aggregates, failed to exhibit either oxidative stress or c-Abl activation. N-acetyl cysteine, a thiol repletion agent that supports neuronal glutathione metabolism, suppressed the PFF - induced redox stress and c-Abl activation in the wild-type neurons, and likewise suppressed α-synuclein aggregation. Parallel findings were observed in mouse brain: PFF-induced α-synuclein aggregation in the substantia nigra was associated with redox stress, c-Abl activation, and dopaminergic neuronal loss, along with microglial activation and motor impairment, all of which were attenuated with oral N-acetyl cysteine. Similar results were obtained using AAV-mediated α-synuclein overexpression as an alternative means of driving α-synuclein aggregation in vivo. These findings show that α-synuclein aggregates induce c-Abl activation by a redox stress mechanism. c-Abl activation in turn promotes α-synuclein aggregation, in a feed-forward interaction. The capacity of N-acetyl cysteine to interrupt this interaction adds mechanistic support its consideration as a therapeutic in Parkinson's disease.
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http://dx.doi.org/10.1016/j.pneurobio.2021.102070DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8210833PMC
July 2021

Methodological considerations for studies of brain glycogen.

J Neurosci Res 2019 08 20;97(8):914-922. Epub 2019 Mar 20.

Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Health Care System, San Francisco, California.

Glycogen stores in the brain have been recognized for decades, but the underlying physiological function of this energy reserve remains elusive. This uncertainty stems in part from several technical challenges inherent in the study of brain glycogen metabolism. These include low glycogen content in the brain, non-homogeneous labeling of glycogen by radiotracers, rapid glycogenolysis during postmortem tissue handling, and effects of the stress response on brain glycogen turnover. Here we briefly review the aspects of the glycogen structure and metabolism that bear on these technical challenges and present ways they can be addressed.
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http://dx.doi.org/10.1002/jnr.24412DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6565471PMC
August 2019
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