Publications by authors named "Xuzhe Zhao"

10 Publications

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Combining MGMT promoter pyrosequencing and protein expression to optimize prognosis stratification in glioblastoma.

Cancer Sci 2021 Jun 11. Epub 2021 Jun 11.

Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Pyrosequencing (PSQ) represents the golden standard for MGMT promoter status determination. Binary interpretation of results based on the threshold from the average of several CpGs tested would neglect the existence of the "gray zone". How to define the gray zone and reclassify patients in this subgroup remains to be elucidated. A consecutive cohort of 312 primary glioblastoma patients were enrolled. CpGs 74-81 in the promoter region of MGMT were tested by PSQ and the protein expression was assessed by immunohistochemistry (IHC). Receiver operating characteristic curves were constructed to calculate the area under the curves (AUC). Kaplan-Meier plots were used to estimate the survival rate of patients compared by the log-rank test. The optimal threshold of each individual CpG differed from 5% to 11%. Patients could be separated into the hypomethylated subgroup (all CpGs tested below the corresponding optimal thresholds, n = 126, 40.4%), hypermethylated subgroup (all CpGs tested above the corresponding optimal thresholds, n = 108, 34.6%), and the gray zone subgroup (remaining patients, n = 78, 25.0%). Patients in the gray zone harbored an intermediate prognosis. The IHC score instead of the average methylation levels could successfully predict the prognosis for the gray zone (AUC for overall survival, 0.653 and 0.519, respectively). Combining PSQ and IHC significantly improved the efficiency of survival prediction (AUC: 0.662, 0.648, and 0.720 for PSQ, IHC, and combined, respectively). Immunohistochemistry is a robust method to predict prognosis for patients in the gray zone defined by PSQ. Combining PSQ and IHC could significantly improve the predictive ability for clinical outcomes.
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http://dx.doi.org/10.1111/cas.15024DOI Listing
June 2021

Corrigendum: Distinguishing Pseudoprogression From True Early Progression in Isocitrate Dehydrogenase Wild-Type Glioblastoma by Interrogating Clinical, Radiological and Molecular Features.

Front Oncol 2021 19;11:700599. Epub 2021 May 19.

Department of Neurosurgery, National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

[This corrects the article DOI: 10.3389/fonc.2021.627325.].
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http://dx.doi.org/10.3389/fonc.2021.700599DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8171117PMC
May 2021

Differential Predictors and Clinical Implications Associated With Long-Term Survivors in IDH Wildtype and Mutant Glioblastoma.

Front Oncol 2021 13;11:632663. Epub 2021 May 13.

Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Background: Glioblastoma (GBM) is the most aggressive intracranial tumor which can be divided into two subtypes based on status of isocitrate dehydrogenase (IDH). A small fraction of patients after receiving standard treatment can be long-term survivors (LTS). This study was designed to disclose the predictors and clinical implications associated with LTS in IDH wildtype and mutant GBM.

Methods: Patients who survived beyond five years after diagnosis of GBM were defined as LTS, while those with a survival less than one year were defined as short-term survivors (STS). A total of 211 patients with diagnosis of GBM in Beijing Tiantan Hospital from January 2007 to January 2015 were enrolled, including 44 (20.9%) LTS and 167 (79.1%) STS. The clinical, radiological and molecular features between groups were systematically compared.

Results: Compared with STS, LTS were a subgroup of patients with a younger age at diagnosis (=0.006), a higher KPS score (=0.011), higher rates of cystic change (=0.037), O-methylguanine-DNA methyltransferase (MGMT) promoter methylation (=0.007), and IDH mutation (=0.049), and more likely to have undergone gross total resection (<0.001). Survival analysis demonstrated that LTS with wildtype IDH conferred a longer progression-free survival (66.0 27.0 months, =0.04), but a shorter post-progression survival (46.5 months not reached, =0.0001) than those of LTS with mutant IDH. LTS with mutant IDH showed a trend towards increased survival after receiving re-operation (=0.155) and reirradiation (=0.127), while this clinical benefit disappeared in the subset of LTS with wildtype IDH (>0.05).

Conclusion: The prognostic value and therapeutic implications associated with LTS in GBM population significantly differed on the basis of IDH status. Our findings provide a new approach for physicians to better understand the two subtypes of GBM, which may assist in making more tailored treatment decisions for patients.
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http://dx.doi.org/10.3389/fonc.2021.632663DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8155513PMC
May 2021

Combination of Immunotherapy and Radiotherapy for Recurrent Malignant Gliomas: Results From a Prospective Study.

Front Immunol 2021 7;12:632547. Epub 2021 May 7.

Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Background: World Health Organization (WHO) grade IV glioma remains one of the most lethal tumors with a dismal prognosis and inevitable recurrence. We evaluated the safety and efficacy of immunotherapy with radiotherapy in this population of patients.

Methods: This study was a single-arm, open-label, phase I trial based on patients with recurrent WHO grade IV glioma. Patients were treated with intracranial and systemic immunoadjuvants in combination with low-dose reirradiation. The primary endpoint of the present trial was safety. Secondary endpoints were overall survival (OS) and progression-free survival (PFS). This trial is registered at ClinicalTrials.gov, NCT03392545.

Results: Thirty patients were enrolled. The most common adverse events (AEs) were fever (66.7%), vomiting (33.3%), headache (30.0%), and fatigue (23.3%). Only a single patient experienced grade 3 fever, and no grade 4 AEs or deaths related to treatment were observed. Of the 30 patients, 1 (3.3%) had a complete response, 5 (16.7%) had a partial response, 9 (30.0%) had stable disease, and 15 (50.0%) had progressive disease, resulting in an objective response rate of 20.0%. The median PFS of the entire cohort was 88.0 (61.0-254.0) days, and the median OS was 362.0 (197.0-601.0) days. Patients could be divided into responders and non-responders, and these groups exhibited a significant difference in terms of survival time, T lymphocyte subsets, frequency of cell division cycle 27 (CDC27) mutation status, and CD15 and CD68 expression (<0.05).

Conclusion: The combination of immunotherapy and radiotherapy is well tolerated and may provide clinical benefit for patients with recurrent WHO grade IV glioma. A prospective phase II study is needed to further validate the efficacy of our therapeutic regimen.
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http://dx.doi.org/10.3389/fimmu.2021.632547DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8138184PMC
May 2021

Distinguishing Pseudoprogression From True Early Progression in Isocitrate Dehydrogenase Wild-Type Glioblastoma by Interrogating Clinical, Radiological, and Molecular Features.

Front Oncol 2021 20;11:627325. Epub 2021 Apr 20.

Department of Neurosurgery, National Clinical Research Center for Neurological Diseases, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Pseudoprogression (PsP) mimics true early progression (TeP) in conventional imaging, which poses a diagnostic challenge in glioblastoma (GBM) patients who undergo standard concurrent chemoradiation (CCRT). This study aimed to investigate whether perioperative markers could distinguish and predict PsP from TeP in isocitrate dehydrogenase (IDH) wild-type GBM patients. New or progressive gadolinium-enhancing lesions that emerged within 12 weeks after CCRT were defined as early progression. Lesions that remained stable or spontaneously regressed were classified as PsP, otherwise persistently enlarged as TeP. Clinical, radiological, and molecular information were collected for further analysis. Patients in the early progression subgroup were divided into derivation and validation sets (7:3, according to operation date). Among 234 consecutive cases enrolled in this retrospective study, the incidences of PsP, TeP, and neither patterns of progression (nP) were 26.1% (61/234), 37.6% (88/234), and 36.3% (85/234), respectively. In the early progression subgroup, univariate analysis demonstrated female (: 2.161, = 0.026), gross total removal (GTR) of the tumor (: 6.571, < 001), located in the frontal lobe (: 2.561, = 0.008), non-subventricular zone (SVZ) infringement (: 10.937, < 0.001), and methylated O-6-methylguanine-DNA methyltransferase (MGMT) promoter (mMGMTp) (: 9.737, < 0.001) were correlated with PsP, while GTR, non-SVZ infringement, and mMGMTp were further validated in multivariate analysis. Integrating quantitative MGMTp methylation levels from pyrosequencing, GTR, and non-SVZ infringement showed the best discriminative ability in the random forest model for derivation and validation set (AUC: 0.937, 0.911, respectively). Furthermore, a nomogram could effectively evaluate the importance of those markers in developing PsP (C-index: 0.916) and had a well-fitted calibration curve. Integrating those clinical, radiological, and molecular features provided a novel and robust method to distinguish PsP from TeP, which was crucial for subsequent clinical decision making, clinical trial enrollment, and prognostic assessment. By in-depth interrogation of perioperative markers, clinicians could distinguish PsP from TeP independent from advanced imaging.
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http://dx.doi.org/10.3389/fonc.2021.627325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8093388PMC
April 2021

Classification of Progression Patterns in Glioblastoma: Analysis of Predictive Factors and Clinical Implications.

Front Oncol 2020 3;10:590648. Epub 2020 Nov 3.

Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.

Background: This study was designed to explore the progression patterns of IDH-wildtype glioblastoma (GBM) at first recurrence after chemoradiotherapy.

Methods: Records from 247 patients who underwent progression after diagnosis of IDH-wildtype GBM was retrospectively reviewed. Progression patterns were classified as either local, distant, subependymal or leptomeningeal dissemination based on the preoperative and serial postoperative radiographic images. The clinical and molecular characteristics of different progression patterns were analyzed.

Results: A total of 186 (75.3%) patients had local progression, 15 (6.1%) patients had distant progression, 33 (13.3%) patients had subependymal dissemination, and 13 (5.3%) patients had leptomeningeal dissemination. The most favorable survival occurred in patients with local progression, while no significant difference of survival was found among patients with distant progression, subependymal or leptomeningeal dissemination who were thereby reclassified into non-local group. Multivariable analysis showed that chemotherapy was a protective factor for non-local progression, while gender of male, subventricular zone (SVZ) involvement and O-methylguanine-DNA-methyltransferase (MGMT) promoter methylation were confirmed as risk factors for non-local progression ( < 0.05). Based on the factors screened by multivariable analysis, a nomogram was constructed which conferred high accuracy in predicting non-local progression. Patients in non-local group could be divided into long- and short-term survivors who differed in the rates of SVZ involvement, MGMT promoter methylation and reirradiation ( < 0.05), and a nomogram integrating these factors showed high accuracy in predicting long-term survivors.

Conclusion: Patients harboring different progression patterns conferred distinct clinical and molecular characteristics. Our nomograms could provide theoretical references for physicians to make more personalized and precise treatment decisions.
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http://dx.doi.org/10.3389/fonc.2020.590648DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7673412PMC
November 2020

Climate change and landscape-use patterns influence recent past distribution of giant pandas.

Proc Biol Sci 2020 06 24;287(1929):20200358. Epub 2020 Jun 24.

Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, People's Republic of China.

Climate change is one of the most pervasive threats to biodiversity globally, yet the influence of climate relative to other drivers of species depletion and range contraction remain difficult to disentangle. Here, we examine climatic and non-climatic correlates of giant panda () distribution using a large-scale 30 year dataset to evaluate whether a changing climate has already influenced panda distribution. We document several climatic patterns, including increasing temperatures, and alterations to seasonal temperature and precipitation. We found that while climatic factors were the most influential predictors of panda distribution, their importance diminished over time, while landscape variables have become relatively more influential. We conclude that the panda's distribution has been influenced by changing climate, but conservation intervention to manage habitat is working to increasingly offset these negative consequences.
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http://dx.doi.org/10.1098/rspb.2020.0358DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7329028PMC
June 2020

Applying Low-Frequency Vibration for the Experimental Investigation of Clutch Hub Forming.

Materials (Basel) 2018 May 30;11(6). Epub 2018 May 30.

School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.

A vibration-assisted plastic-forming method was proposed, and its influence on clutch hub forming process was investigated. The experiments were conducted on a vibration-assisted hydraulic extrusion press with adjustable frequency and amplitude. Vibration frequency and amplitude were considered in investigating the effect of vibration on forming load and surface quality. Results showed that applying vibration can effectively reduce forming force and improve surface quality. The drop in forming load was proportional to the vibration frequency and amplitude, and the load decreased by up to 25%. Such reduction in forming load raised with amplitude increase because the increase in amplitude would accelerate punch relative speed, which then weakened the adhesion between workpiece and dies. By increasing the vibration frequency, the punch movement was enhanced, and the number of attempts to drag the lubricant out of the pits was increased. In this manner, the lubrication condition was improved greatly. The 3D surface topography testing confirmed the assumption. Moreover, vibration frequency exerted a more significant effect on the forming load reduction than vibration amplitude.
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http://dx.doi.org/10.3390/ma11060928DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6025413PMC
May 2018

Investigation of Flat Clinching Process Combined with Material Forming Technology for Aluminum Alloy.

Materials (Basel) 2017 Dec 15;10(12). Epub 2017 Dec 15.

School of Engineering Technology, Purdue University, West Lafayette, IN 47906, USA.

In recent years, the use of aluminum alloy has tended to increase for building lightweight automobiles to reduce their automotive weight, which is helpful to save energy and protect the environment. In order to join aluminum alloy, a flat-clinching process combined with material forming technology was investigated to join aluminum alloy sheets using an experimental and a numerical method. Al1060 was chosen as the material of the sheet, and DEFORM-2D software was used to build the numerical model. After the numerical model was validated by the experimental results, the influences of punch diameter and holder force on the materials deforming behavior of the clinched joint were analyzed using the numerical model. Then, the material flow, joining ability, and joining quality were investigated to assess the clinched joint. The results showed that an increase in punch diameter could give rise to an increase in neck thickness and interlocking length, while an increase in blank holder force induced a decrease in interlocking length and an increase in neck thickness. The joining quality could be increased by increasing the forming force. It can be concluded that a clinched joint has better joining quality for joining light-weight sheets onto automotive structures.
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http://dx.doi.org/10.3390/ma10121433DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5744368PMC
December 2017

Experimental Investigation on the Joining of Aluminum Alloy Sheets Using Improved Clinching Process.

Materials (Basel) 2017 Aug 1;10(8). Epub 2017 Aug 1.

Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima 770-8506, Japan.

Aluminum alloy sheets have been widely used to build the thin-walled structures by mechanical clinching technology in recent years. However, there is an exterior protrusion located on the lower sheet and a pit on the upper sheet, which may restrict the application of the clinching technology in visible areas. In the present study, an improved clinched joint used to join aluminum alloy sheets was investigated by experimental method. The improved clinching process used for joining aluminum alloy evolves through four phases: (a) localized deformation; (b) drawing; (c) backward extrusion; and (d) mechanical interlock forming. A flat surface can be produced using the improved clinching process. Shearing strength, tensile strength, material flow, main geometrical parameters, and failure mode of the improved clinched joint were investigated. The sheet material was compressed to flow radially and upward using a punch, which generated a mechanical interlock by producing severe localized plastic deformation. The neck thickness and interlock of the improved clinched joint were increased by increasing the forming force, which also contributed to increase the strength of the clinched joint. The improved clinched joint can get high shearing strength and tensile strength. Three main failure modes were observed in the failure process, which were neck fracture mode, button separation mode, and mixed failure mode. The improved clinched joint has better joining quality to join aluminum alloy sheets on the thin-walled structures.
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http://dx.doi.org/10.3390/ma10080887DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5578253PMC
August 2017
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