Publications by authors named "Liman Liu"

5 Publications

  • Page 1 of 1

Assessing Agreement between Frequency-Specific Chirp Auditory Steady-State Response and Pure Tone Audiometry in Adults by Intraclass Correlation Coefficient.

ORL J Otorhinolaryngol Relat Spec 2021 May 12:1-9. Epub 2021 May 12.

Department of Otorhinolaryngology Head and Neck Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.

Introduction: Chirp auditory steady-state response (ASSR) can be used to assess frequency-specific hearing thresholds. However, its reliability has not been confirmed yet. The purpose of this proposed study is to analyze the agreement of thresholds measured by chirp-ASSR and pure tone audiometry (PTA) to investigate the value of chirp-ASSR in hearing threshold evaluation.

Methods: Participants with normal hearing (age: 18-66, 108 ears) and patients with sensorineural hearing loss (age: 22-82, 75 ears) were tested using PTA and chirp-ASSR at 0.5, 1, 2, and 4 kHz, respectively. Intraclass correlation coefficient (ICC) and Bland-Altman plot were introduced to analyze the agreement between the 2 methods.

Results: One-hundred eight participants underwent both chirp-ASSR and PTA to estimate their thresholds. The ICCs yielded by these 2 methods are 0.757, 0.893, 0.883, and 0.921 (p < 0.001) at 0.5, 1, 2, and 4 kHz carrier frequency, respectively. However, there is a significant difference between the 2 methods at 2 kHz: the mean value of the ASSR thresholds is 5.27 dB HL higher than the value of PTA thresholds. Additionally, the 95% limits of agreement range from -27.48 to 26.66 dB HL at 0.5 kHz, from -18.19 to 17.87 dB HL at 1 kHz, from -12.01 to 22.55 dB HL at 2 kHz, and from -21.29 to 19.17 dB HL at 4 kHz, which are large enough to affect clinical decision-making.

Conclusion: In this study, we have confirmed good to excellent correlation between chirp-ASSR and PTA in threshold estimation for adults with and without hearing loss. The degree of correlations is higher for participants with hearing loss and for measurements at high frequencies. However, significant systematic difference and large limits of agreement between the 2 methods have been found. These findings show that chirp-ASSR can be treated as a supplementary method to PTA when evaluating the hearing level, but the 2 methods are not interchangeable due to their systematic difference and large limits of agreement.
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http://dx.doi.org/10.1159/000515237DOI Listing
May 2021

Toxic Effects of 3,3'-Iminodipropionitrile on Vestibular System in Adult C57BL/6J Mice .

Neural Plast 2020 3;2020:1823454. Epub 2020 Jul 3.

ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200031, China.

The utricle is one of the five sensory organs in the mammalian vestibular system, and while the utricle has a limited ability to repair itself, this is not sufficient for the recovery of vestibular function after hair cell (HC) loss induced by ototoxic drugs. In order to further explore the possible self-recovery mechanism of the adult mouse vestibular system, we established a reliable utricle epithelium injury model for studying the regeneration of HCs and examined the toxic effects of 3,3'-iminodiproprionitrile (IDPN) on the utricle in C57BL/6J mice, which is one of the most commonly used strains in inner ear research. This work focused on the epithelial cell loss, vestibular dysfunction, and spontaneous cell regeneration after IDPN administration. HC loss and supporting cell (SC) loss after IDPN treatment was dose-dependent and resulted in dysfunction of the vestibular system, as indicated by the swim test and the rotating vestibular ocular reflex (VOR) test. EdU-positive SCs were observed only in severely injured utricles wherein above 47% SCs were dead. No EdU-positive HCs were observed in either control or injured utricles. RT-qPCR showed transient upregulation of and and fluctuating upregulation of and after IDPN administration. We conclude that a single intraperitoneal injection of IDPN is a practical way to establish an injured utricle model in adult C57BL/6J mice . We observed activation of Notch and Wnt signaling during the limited spontaneous HC regeneration after vestibular sensory epithelium damage, and such signaling might act as the promoting factors for tissue self-repair in the inner ear.
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http://dx.doi.org/10.1155/2020/1823454DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7354661PMC
July 2020

Bmi1 Regulates the Proliferation of Cochlear Supporting Cells Via the Canonical Wnt Signaling Pathway.

Mol Neurobiol 2017 03 3;54(2):1326-1339. Epub 2016 Feb 3.

Department of Otorhinolaryngology and Hearing Research Institute of Affiliated Eye and ENT Hospital, State Key Laboratory of Medicine Neurobiology, Fudan University, Room 611, Building 9, No. 83, Fenyang Road, Xuhui District, Shanghai, 200031, China.

Cochlear supporting cells (SCs), which include the cochlear progenitor cells, have been shown to be a promising resource for hair cell (HC) regeneration, but the mechanisms underlying the initiation and regulation of postnatal cochlear SC proliferation are not yet fully understood. Bmi1 is a member of the Polycomb protein family and has been reported to regulate the proliferation of stem cells and progenitor cells in multiple organs. In this study, we investigated the role of Bmi1 in regulating SC and progenitor cell proliferation in neonatal mice cochleae. We first showed that knockout of Bmi1 significantly inhibited the proliferation of SCs and Lgr5-positive progenitor cells after neomycin injury in neonatal mice in vitro, and we then showed that Bmi1 deficiency significantly reduced the sphere-forming ability of the organ of Corti and Lgr5-positive progenitor cells in neonatal mice. These results suggested that Bmi1 is required for the initiation of SC and progenitor cell proliferation in neonatal mice. Next, we found that DKK1 expression was significantly upregulated, while beta-catenin and Lgr5 expression were significantly downregulated in neonatal Bmi1 mice compared to wild-type controls. The observation that Bmi1 knockout downregulates Wnt signaling provides compelling evidence that Bmi1 is required for the Wnt signaling pathway. Furthermore, the exogenous Wnt agonist BIO overcame the downregulation of SC proliferation in Bmi1 mice, suggesting that Bmi1 knockout might inhibit the proliferation of SCs via downregulation of the canonical Wnt signaling pathway. Our findings demonstrate that Bmi1 plays an important role in regulating the proliferation of cochlear SCs and Lgr5-positive progenitor cells in neonatal mice through the Wnt signaling pathway, and this suggests that Bmi1 might be a new therapeutic target for HC regeneration.
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http://dx.doi.org/10.1007/s12035-016-9686-8DOI Listing
March 2017

Dynamic expression of Lgr6 in the developing and mature mouse cochlea.

Front Cell Neurosci 2015 12;9:165. Epub 2015 May 12.

Key Laboratory of Hearing Medicine, Ministry of Health, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China ; Department of Otorhinolaryngology, Affiliated Eye and ENT Hospital of Fudan University Shanghai, China ; The State Key Laboratory of Medical Neurobiology, The Institutes of Brain Science and the Collaborative Innovation Center for Brain Science, Fudan University Shanghai, China.

The Wnt/β-catenin signaling pathway plays important roles in mammalian inner ear development. Lgr5, one of the downstream target genes of the Wnt/β-catenin signaling pathway, has been reported to be a marker for inner ear hair cell progenitors. Lgr6 shares approximately 50% sequence homology with Lgr5 and has been identified as a stem cell marker in several organs. However, the detailed expression profiles of Lgr6 have not yet been investigated in the mouse inner ear. Here, we first used Lgr6-EGFP-Ires-CreERT2 mice to examine the spatiotemporal expression of Lgr6 protein in the cochlear duct during embryonic and postnatal development. Lgr6-EGFP was first observed in one row of prosensory cells in the middle and basal turn at embryonic day 15.5 (E15.5). From E18.5 to postnatal day 3 (P3), the expression of Lgr6-EGFP was restricted to the inner pillar cells (IPCs). From P7 to P15, the Lgr6-EGFP expression level gradually decreased in the IPCs and gradually increased in the inner border cells (IBCs). At P20, Lgr6-EGFP was only expressed in the IBCs, and by P30 Lgr6-EGFP expression had completely disappeared. Next, we demonstrated that Wnt/β-catenin signaling is required to maintain the Lgr6-EGFP expression in vitro. Finally, we demonstrated that the Lgr6-EGFP-positive cells isolated by flow cytometry could differentiate into myosin 7a-positive hair cells after 10 days in-culture, and this suggests that the Lgr6-positive cells might serve as the hair cell progenitor cells in the cochlea.
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http://dx.doi.org/10.3389/fncel.2015.00165DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4428082PMC
June 2015

Automatic segmentation of the left ventricle in cardiac MRI using local binary fitting model and dynamic programming techniques.

PLoS One 2014 11;9(12):e114760. Epub 2014 Dec 11.

Department of Radiology of Tongji Hospital affiliated to Huazhong University of Science and Technology, Wuhan, People's Republic of China.

Segmentation of the left ventricle is very important to quantitatively analyze global and regional cardiac function from magnetic resonance. The aim of this study is to develop a novel algorithm for segmenting left ventricle on short-axis cardiac magnetic resonance images (MRI) to improve the performance of computer-aided diagnosis (CAD) systems. In this research, an automatic segmentation method for left ventricle is proposed on the basis of local binary fitting (LBF) model and dynamic programming techniques. The validation experiments are performed on a pool of data sets of 45 cases. For both endo- and epi-cardial contours of our results, percentage of good contours is about 93.5%, the average perpendicular distance are about 2 mm. The overlapping dice metric is about 0.91. The regression and determination coefficient between the experts and our proposed method on the LV mass is 1.038 and 0.9033, respectively; they are 1.076 and 0.9386 for ejection fraction (EF). The proposed segmentation method shows the better performance and has great potential in improving the accuracy of computer-aided diagnosis systems in cardiovascular diseases.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0114760PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4263664PMC
October 2015