Browsing by Author "Ouyang, Zheng"

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    Intraoperative detection of isocitrate dehydrogenase mutations in human gliomas using a miniature mass spectrometer
    (SpringerLink, 2019-12) Brown, Hannah Marie; Pu, Fan; Dey, Mahua; Miller, James; Shah, Mitesh V.; Shapiro, Scott A.; Ouyang, Zheng; Cohen-Gadol, Aaron A.; Cooks, R. Graham; Neurological Surgery, School of Medicine
    Knowledge of the isocitrate dehydrogenase (IDH) mutation status of glioma patients could provide insights for decision-making during brain surgery. However, pathology is not able to provide such information intraoperatively. Here we describe the first application of a miniature mass spectrometer (MS) to the determination of IDH mutation status in gliomas intraoperatively. The instrumentation was modified to be compatible with use in the operating room. Tandem MS was performed on the oncometabolite, 2-hydroxyglutarate, and a reference metabolite, glutamate, which is not involved in the IDH mutation. Ratios of fragment ion intensities were measured to calculate an IDH mutation score, which was used to differentiate IDH mutant and wild-type tissues. The results of analyzing 25 biopsies from 13 patients indicate that reliable determination of IDH mutation status was achieved (p = 0.0001, using the Kruskal-Wallis non-parametric test). With its small footprint and low power consumption and noise level, this application of miniature mass spectrometers represents a simple and cost-effective platform for an important intraoperative measurement.
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    Neuroprotective Ferulic Acid (FA)-Glycol Chitosan (GC) Nanoparticles for Functional Restoration of Traumatically Injured Spinal Cord
    (Elsevier B.V., 2014-02) Wu, Wei; Lee, Seung-Young; Wu, Xiangbing; Tyler, Jacqueline Y.; Wang, He; Ouyang, Zheng; Park, Kinam; Xu, Xiao-Ming; Cheng, Ji-Xin; Department of Neurological Surgery, IU School of Medicine
    An urgent unmet need exists for early-stage treatment of spinal cord injury (SCI). Currently methylprednisolone is the only therapeutic agent used in clinics, for which the efficacy is controversial and the side effect is well-known. We demonstrated functional restoration of injured spinal cord by self-assembled nanoparticles composed of ferulic acid modified glycol chitosan (FA-GC). Chitosan and ferulic acid are strong neuroprotective agents but their systemic delivery is difficult. Our data has shown a prolonged circulation time of the FA-GC nanoparticles allowing for effective delivery of both chitosan and ferulic acid to the injured site. Furthermore, the nanoparticles were found both in the gray matter and white matter. The in vitro tests demonstrated that nanoparticles protected primary neurons from glutamate-induced excitotoxicity. Using a spinal cord contusion injury model, significant recovery in locomotor function was observed in rats that were intravenously administered nanoparticles at 2 h post injury, as compared to non-improvement by methylprednisolone administration. Histological analysis revealed that FA-GC treatment significantly preserved axons and myelin and also reduced cavity volume, astrogliosis, and inflammatory response at the lesion site. No obvious adverse effects of nanoparticles to other organs were found. The restorative effect of FA-GC presents a promising potential for treating human SCIs.