Browsing by Author "Zhang, Hui"

Now showing 1 - 5 of 5
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    Objective and Quantitative Assessment of Caries Lesion Activity
    (Elsevier, 2018) Ando, Masatoshi; Fontana, Margherita; Eckert, George J.; Arthur, Rodrigo A.; Zhang, Hui; Zero, Domenick T.; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Objectives Evaluate the ability of objectively measured specular reflection, roughness, and fluorescence change during dehydration to assess caries lesion activity. Methods One hundred ninety-five ground/polished 3 × 3 × 2 mm sound human enamel specimens were divided into three groups and demineralized using a multispecies microbial caries model for 3, 6, or 9 days; and then remineralized with 1100 ppm-F as NaF solution for 10 days using a pH-cyclic model. Reflection (amplitude: %), roughness (Ra: μm), fluorescence change during dehydration (ΔQ: %×mm2), and microfocus computed tomography [μ-CT: lesion volume (μm3)] were measured for sound, demineralized and remineralized enamel. The surface was hydrated and fluorescence images were acquired at 1 s intervals for 10 s (ΔQ10). During image acquisition, surface was dehydrated with continuous compressed air. Changes-in-ΔQ per second (ΔQD: %×mm2/sec) at 5 (ΔQD5) and 10 s (ΔQD10) were obtained. Results Reflection decreased from sound to demineralized groups (p < 0.0001); remineralized groups were higher than demineralized groups (p < 0.001), but not different from sound (p > 0.32). Roughness increased from sound to demineralized groups (p < 0.0001) and remineralized groups were also higher than sound (p < 0.0001). ΔQ10, ΔQD5 and ΔQD10 increased from sound to demineralized groups (p < 0.0001), and remineralized groups decreased compared to demineralized groups (p < 0.05), but was higher than sound (p < 0.0001). The correlations of μ-CT with reflection, roughness, and ΔQ10 were −0.63, 0.71, and 0.82, respectively (p < 0.0001). Conclusions Reflection, roughness and ΔQ could distinguish between sound and demineralized enamel. Reflection and ΔQ were able to distinguish between demineralized and remineralized enamel. Clinical significance Determination of caries activity, whether a lesion is active or inactive, is an essential and critical component of caries diagnosis. However, especially for enamel lesions, it is difficult to estimate without longitudinal follow-up. Reflection, roughness and fluorescence change during dehydration have the potential to measure caries lesion activity at a-single-appointment.
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    PInfer: Learning to Infer Concurrent Request Paths from System Kernel Events
    (IEEE, 2016-07) Xu, Hongteng; Ning, Xia; Zhang, Hui; Rhee, Junghwan; Jiang, Guofei; Department of Computer and Information Science, School of Science
    Operating system kernel-level tracers are popularly used in the post-development stage by black-box approaches. By inferring service request processing paths from kernel events, these approaches enabled system diagnosis and performance management that are application-logic aware. However, asynchronous communications and multi-threading behaviors make request path patterns dynamic on the kernel event level, this causes previous methods to focus on either software instrumentation techniques or better statistical inference models. In this paper, we propose a novel learning based approach called PInfer that infers request processing path patterns automatically with high precision. PInfer first learns dynamic event patterns of inter-thread and intra-thread service processing from the training data of sequential requests. On the testing data containing concurrent requests, PInfer infers individual request processing paths by effectively solving a graph matching problem and a generalized assignment problem based on the learned patterns. We have implemented our approach in a proprietary system performance diagnosis tool, and present performance results on 40 sets of kernel event traces. PInfer achieves on average 65% precision and 85% recall for profiling concurrent request processing paths.
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    PRMT5 is upregulated by B-cell receptor signaling and forms a positive-feedback loop with PI3K/AKT in lymphoma cells
    (Springer, 2019-05-23) Zhu, Fen; Guo, Hui; Bates, Paul D.; Zhang, Shanxiang; Zhang, Hui; Nomie, Krystle J.; Li, Yangguang; Lu, Li; Seibold, Kaitlyn R.; Wang, Fangyu; Rumball, Ian; Cameron, Hunter; Hoang, Nguyet M.; Yang, David T.; Xu, Wei; Zhang, Liang; Wang, Michael; Capitini, Christian M.; Rui, Lixin; Pathology and Laboratory Medicine, School of Medicine
    PRMT5, which regulates gene expression by symmetric dimethylation of histones and non-histone target proteins, is overexpressed and plays a pathogenic role in many cancers. In diffuse large B cell lymphoma (DLBCL), the mechanisms of PRMT5 dysregulation and its role in lymphomagenesis remain largely unknown. Here we demonstrate that B cell receptor (BCR) signaling regulates PRMT5 expression in DLBCL cells. Immunohistochemical analysis reveals elevated levels of PRMT5 expression in DLBCL cases and in germinal center (GC) B cells when compared to naive B cells. PRMT5 can be induced in naive B cells by BCR stimulation. We discovered that BTK-NF-κB signaling induces PRMT5 transcription in activated B cell-like (ABC) DLBCL cells while BCR downstream PI3K-AKT-MYC signaling upregulates PRMT5 expression in both ABC and GCB DLBCL cells. PRMT5 inhibition inhibits the growth of DLBCL cells in vitro and patient derived xenografts. Genomic and biochemical analysis demonstrate that PRMT5 promotes cell cycle progression and activates PI3K-AKT signaling, suggesting a feedback regulatory mechanism to enhance cell survival and proliferation. Co-targeting PRMT5 and AKT by their specific inhibitors is lethal to DLBCL cell lines and primary cancer cells. Therefore, this study provides a mechanistic rationale for clinical trials to evaluate PRMT5 and AKT inhibitors for DLBCL.
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    Reduced expression of IA channels is associated with post-ischemic seizures
    (Elsevier, 2016-08) Lei, Zhigang; Zhang, Hui; Liang, Yanling; Xu, Zao C.; Anatomy and Cell Biology, School of Medicine
    Purpose Post-stroke seizures are considered as a major cause of epilepsy in adults. The pathophysiologic mechanisms resulting in post-stroke seizures are not fully understood. The present study attempted to reveal a new mechanism underlying neuronal hyperexcitability responsible to the seizure development after ischemic stroke. Methods Transient global ischemia was produced in adult Wistar rats using the 4-vessel occlusion (4-VO) method. The spontaneous behavioral seizures were defined by the Racine scale III – V. The neuronal death in the brain was determined by hematoxylineosin staining. The expression levels of A-type potassium channels were analyzed by immunohistochemical staining and western blotting. Results We found that the incidence of spontaneous behavioral seizures increased according to the severity of ischemia with 0% after 15-min ischemia and ~50% after 25- min ischemia. All behavioral seizures occurred with 48 hrs after ischemia. Morphological analysis indicated that brain damage was not correlated with behavioral seizures. Immunohistochemical staining showed that the expression levels of the A-type potassium channel subunit Kv4.2 was significantly reduced in ischemic brains with behavioral seizures, but not in ischemic brains without seizures. In addition, rats failing to develop spontaneous behavioral seizures within 2 days after ischemia were more sensitive to bicuculline-induced seizures at 2 months after ischemia than control rats. Meanwhile, Kv4.2 expression was decreased in brain at 2 months after ischemia. Conclusion Our results demonstrated the reduction of Kv4.2 expression might contribute to the development of post-ischemic seizures and long-term increased seizure susceptibility after ischemia. The mechanisms underlying post-stroke seizures and epilepsy is unknown so far. The down-regulation of IA channels may explained the abnormal neuronal hyperexcitability responsible for the seizure development after ischemic stroke.
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    Using Clinical Scales and Digital Measures to Explore Falls in Patients with Lewy Body Dementia
    (Karger, 2023-06-21) Battioui, Chakib; Man, Albert; Pugh, Melissa; Wang, Jian; Dang, Xiangnan; Zhang, Hui; Ardayfio, Paul; Munsie, Leanne; Hake, Ann Marie; Biglan, Kevin; Neurology, School of Medicine
    Introduction: PRESENCE was a phase 2 clinical trial assessing the efficacy of mevidalen, a D1 receptor positive allosteric modulator, for symptomatic treatment of Lewy body dementia (LBD). Mevidalen demonstrated improvements in motor and non-motor features of LBD, global functioning, and actigraphy-measured activity and daytime sleep. Adverse events (AEs) of fall were numerically increased in mevidalen-treated participants. Methods: A subset of PRESENCE participants wore a wrist actigraphy device for 2-week periods pre-, during, and posttreatment. Actigraphy sleep and activity measures were derived per period and analyzed to assess for their association with participants' reports of an AE of fall. Prespecified baseline and treatment-emergent clinical characteristics were also included in the retrospective analysis of falls. Independent-samples t test and χ2 test were performed to compare the means and proportions between individuals with/without falls. Results: A trend toward more falls was observed with mevidalen treatment (31/258 mevidalen-treated vs. 4/86 in placebo-treated participants: p = 0.12). Higher body mass index (BMI) (p < 0.05), more severe disease measured by baseline Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part II (p < 0.05), and a trend toward improved Alzheimer's Disease Assessment Scale-Cognitive Subscale 13 (ADAS-Cog13) (p = 0.06) were associated with individuals with falls. No statistically significant associations with falls and treatment-emergent changes were observed. Conclusion: The association of falls with worse baseline disease severity and higher BMI and overall trend toward improvements on cognitive and motor scales suggest that falls in PRESENCE may be related to increased activity in mevidalen-treated participants at greater risk for falling. Future studies to confirm this hypothesis using fall diaries and digital assessments are necessary.