Yanming Qu

Capital Medical University, Beijing, Beijing Shi, China

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Publications (7)18.78 Total impact

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    ABSTRACT: Detection of brain gliomas at the earliest stage is of great importance to improve the outcomes but remains the most challenging task. In this study, oleic acid capped manganese oxide (MnO) NPs were prepared by the thermal decomposition of manganese oleate precursors and then transformed to water-dispersible MnO NPs by replacing oleic acid with N-(trimethoxysilylpropyl) ethylene diamine triacetic acid (TETT) silane. The covalently bonded TETT silane offers MnO NPs colloidal stability and abundant carboxylic functional groups allowing the further conjugation of the glioma-specific moiety, folic acid (FA). Moreover, the thin layer of TETT silane ensures a short distance between external Mn ion and water proton, which endows the FA-conjugated, TETT modified MnO (MnO-TETT-FA) NPs a longitudinal relaxivity as high as 4.83 mM-1 s-1. Accordingly, the in vivo MR images demonstrated that MnO-TETT-FA NPs could efficiently enhance the MRI contrast for tiny brain gliomas. More importantly, due to the specificity of FA, MnO-TETT-FA NPs led to a clearer margin of the tiny glioma. This together with the good biocompatibility discloses the great potential of MnO-TETT-FA NPs as an effective MRI contrast agent for the early diagnosis of brain gliomas.
    ACS Applied Materials & Interfaces 10/2014; · 5.90 Impact Factor
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    ABSTRACT: To study the expression level of folate receptor α (FR-α) in glioma tissue and its clinical significance. Forty-eight human glioma specimens were collected from patients who underwent surgery from March 2012 to March 2013. These specimens were as follows:12 cases of glioblastoma (WHO IV), 6 cases of astrocytoma of each malignancy grade(WHO II, III), 6 cases of oligodendroastrocytoma of each malignancy grade (WHO II, III), 6 cases of oligodendroglioma of each malignancy grade (WHO II, III ). In addition, 6 cases of normal brain tissue resected from brain traumatic patients were taken as negative control, and one case of placental tissue (had got the consent of the parents and their families) was taken as positive control. The expression level of FR-α in tumor tissues was evaluated by Western blot analysis. The results of Western blot analysis were analyzed by t-test. The expression level of FR-α and Ki-67 in tumor tissues was evaluated immunohistochemistry, the results were analyzed by Kruskal-Wallis test and Nemenyi test. The correlation between the expression level of FR-α and cell proliferation index Ki-67 was analyzed by Pearson correlation analysis. Western blot analysis showed that the FR-α was not expressed in normal brain tissue and oligodendroglioma tissue, but highly expressed in astrocytoma, oligodendroastrocytoma and gliomablastoma. The expression level in WHO III astrocytoma was significantly higher than in WHO II (t = 4.497, P < 0.05). FR-α was also highly expressed in oligodendroastrocytoma and its expression level in WHO III was also significantly higher than in the WHO II (t = 2.876, P < 0.05). Foremore, immunohistochemistry analysis also showed that FR-α was not expressed in oligodendroglioma, but expressed in astrocytoma, oligodendroastrocytoma and gliomablastoma. The positive rate of FR-α of WHO III was significantly higher than the WHO II astrocytoma(57.8% ± 2.2% vs. 45.7% ± 2.3%,χ(2) = 3.871, P = 0.034). In oligodendroastrocytoma, the positive rate of FR-α of WHO III was significantly higher than the WHO II(56.5% ± 5.4% vs. 37.1% ± 5.2%,χ(2) = 4.454, P = 0.021). Moreover, the expression level of FR-α in gliomablastoma was highest in all histological types of gliomas, the positive rate of FR-α was up to 65.0% ± 4.5%. Pearson correlation analysis showed that the positive rate of FR-α was positively correlated with Ki-67 index (r = 0.903, P < 0.05). FR-α is expressed in astrocytoma, oligodendroastrocytoma and glioblastoma, and the expression level of FR-α is positively correlated with malignancy grade and Ki-67 index. Therefore, FR-α may be applied as a special target for diagnosis and treatment of glioma.
    Zhonghua wai ke za zhi [Chinese journal of surgery] 03/2014; 52(3):202-207.
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    ABSTRACT: Object The aim of this study was to evaluate the clinical results and surgical outcomes of cystic vestibular schwannomas (VSs) with fluid-fluid levels. Methods Forty-five patients with cystic VSs and 86 with solid VSs were enrolled in the study. The patients in the cystic VSs were further divided into those with and without fluid-fluid levels. The clinical and neuroimaging features, intraoperative findings, and surgical outcomes of the 3 groups were retrospectively compared. Results Peritumoral adhesion was significantly greater in the fluid-level group (70.8%) than in the nonfluid-level group (28.6%) and the solid group (25.6%; p < 0.0001). Complete removal of the VS occurred significantly less in the fluid-level group (45.8%, 11/24) than in the nonfluid-level group (76.2%, 16/21) and the solid group (75.6%, 65/86; p = 0.015). Postoperative facial nerve function in the fluid-level group was less favorable than in the other 2 groups; good/satisfactory facial nerve function 1 year after surgery was noted in 50.0% cases in the fluid-level group compared with 83.3% cases in the nonfluid-level group (p = 0.038). Conclusions Cystic VSs with fluid-fluid levels more frequently adhered to surrounding neurovascular structures and had a less favorable surgical outcome. A possible mechanism of peritumoral adhesion is intratumoral hemorrhage and consequent inflammatory reactions that lead to destruction of the tumor-nerve barrier. These findings may be useful in predicting surgical outcome and planning surgical strategy preoperatively.
    Journal of Neurosurgery 07/2013; · 3.15 Impact Factor
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    ABSTRACT: In retrosigmoid craniotomy, neurosurgeons usually depend on surface landmarks and their experience to evaluate the position of transverse-sigmoid sinus junction (TSSJ) and place an appropriate initial burr-hole, which is not accurate each time because of variability in different craniums. The authors introduce a simple procedure based on 3D computed tomography (CT) to localize the TSSJ in retrosigmoid craniotomy. Eighteen patients who underwent retrosigmoid craniotomy were analyzed. On the internal view of skull in 3D CT image, a simulative burr-hole was placed on the margin of transverse-sigmoid sinus groove junction. Then, on the external view of skull in 3D CT image, the center of the simulative burr-hole was marked and a coordinate system was established based on a line connected the digastric point and the asterion. Then the coordinate of the burr-hole's center was measured in this coordinate system. In operation, the burr-hole was placed according to the coordinate measured previously and craniotomy was performed. The margin of TSSJ was exposed in each case. No damage of venous sinus was encountered. Post-operative skull base CT demonstrated a good match between the actual and predicted burr-hole and bone defects only existed along the cut line. This simple method could help in localizing the TSSJ and avoiding the risk of sinus injury and reducing the bone defect. It is sufficiently precise for practical application at surgical planning.
    Neurosurgical Review 05/2012; 35(4):593-9. · 1.97 Impact Factor
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    ABSTRACT: Restenosis is one of several complications following carotid endarterectomy (CEA). The pathogenesis of restenosis may be related to postsurgery inflammation and leukocyte recruitment mediated by cellular adhesion molecules. In this study, we examine the role of vascular cell adhesion molecule-1 (VCAM-1) in carotid neointimal hyperplasia following carotid surgical mechanical de-endothelialization (CSMDE) in a rat model of CEA. The inhibition of siRNA on VCAM-1 protein expression was determined by using the methods of immunostaining and Western blot. Ultrasound imaging and morphometric analysis were applied to measure the degree of CSMDE-induced carotid artery neointimal hyperplasia of rats. We found that a lentivirus-based construct expressing a small interfering RNA (siRNA) against VCAM-1 could effectively (P < .05, n = 10 per group) reduce VCAM-1 protein expression in the carotid arteries of rats undergoing CSMDE (CSMDE+RNAi: 135.0 +/- 27.6%) when compared that of CSMDE with scrambled siRNA (CSMDE+CON: 182.7 +/- 36.4%). Doppler ultrasonography revealed that CSMDE+RNAi was accompanied by a significant reduction in the extent of stenosis demonstrated by increased blood velocity (665.85 +/- 48.37 mm/s) and linear diameter (0.59 +/- 0.77 mm) compared to CSMDE+CON (46.72 +/- 28.67 mm/s with undetectable linear diameter, P < .05, n = 10 per group). In addition, morphometric analysis of hematoxylin and eosin (HE)-stained sections indicated that the intima (innermost layer of media at lesion site)/media area ratio (I/M) was significantly increased (P < .05, n = 10 per group) both in the CSMDE (3.99 +/- 0.65) and CSMDE+CON (4.33 +/- 0.59) groups compared with the SHAM group (0.35 +/- 0.13). However, CSMDE+RNAi resulted in a significant (P < .05, n = 10 per group) decrease in the I/M ratio (1.79 +/- 0.43) compared to CSMDE+CON, whereas there were no significant differences in the total arterial area and medial areas among the groups. These results suggest that perivascular events mediated by VCAM-1 are likely to play an important role in the pathogenesis of carotid artery neointimal hyperplasia in rats after CSMDE.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2009; 50(6):1452-8. · 3.52 Impact Factor
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    ABSTRACT: Several studies have suggested that protein kinase C (PKC) plays a key role in the mechanism of cerebral ischemic/hypoxic preconditioning (I/HPC). However, detailed information regarding PKC isoforms in response to brain ischemia/hypoxia and their potential role in neuroprotection is unclear. Previous studies in our laboratory have demonstrated that the levels in membrane translocation of conventional PKC (cPKC) betaII, gamma, and novel PKCepsilon (nPKC), but not cPKCalpha, betaI, nPKCdelta, eta, mu, theta, and atypical PKC (aPKC) zeta and iota/lambda, were increased significantly in the hippocampus and cortex of intact mice with hypoxic preconditioning. To further detect cPKC and nPKC isoforms activation following prolonged hypoxia in vitro, we tested the membrane translocation (an indicator of PKC activation) of cPKCalpha, betaI, betaII, and gamma, and nPKCdelta, epsilon, eta, mu, and theta in a human neuroblastoma SH-SY5Y cell line following sustained hypoxic exposure (1% O(2)/5% CO(2)/94% N(2)). Using Western blot and immunocytochemistry methods, we found that the levels of cPKCalpha, betaI, betaII, and nPKCepsilon, but not nPKCdelta, eta, mu, and theta, membrane translocation were increased significantly (P < 0.05, n = 8) in a time-dependent manner (from 0.5 to 24 h) following sustained hypoxic exposure. Similarly, the immunostaining experiment also showed a noticeable translocation of cPKCalpha, betaI, betaII, and nPKCepsilon from the cytosol to the perinuclear or membrane-related areas after 6 h posthypoxic exposure. In addition, no cPKCgamma was detected in this cell line under either a normoxic or hypoxic condition. These results suggested that prolonged hypoxia may induce the activation of cPKCalpha, betaI, betaII, and nPKCepsilon by triggering their membrane translocation in SH-SY5Y cells.
    Brain Research 07/2006; 1093(1):25-32. · 2.88 Impact Factor
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    ABSTRACT: Leptomeningeal metastasis (LM) is caused by the spread of malignant tumor cells into the subarachnoid space. However, classification and staging of LM in the spinal canal is rare in the literature. The authors reviewed the records of 58 Chinese patients with LM for clinical features, neuroimaging, and treatments. Gadolinium-enhanced magnetic resonance imaging (MRI) of brain and spinal cord were performed in all patients. Removal of intracranial tumors was performed in all patients and diagnoses were confirmed by histology. The study group consisted of 58 patients, with 29 cases presenting with intraspinal symptoms. Of the 58, 8 patients underwent intraspinal tumor removal, 8 received radiotherapy alone, 9 received chemotherapy alone, and 34 patients received combined radiochemotherapy. We classified LM into 3 types: type L or leptomeninges LM, is subdivided into 2 subtypes (subtype LI and LII (a,b)), type N or nerve root LM is subdivided into 2 subtypes (subtype NI and NII (a,b)), and type M or mixed-type LM. We also divided LM into stages of I-IV according to the symptoms and the volume of the tumor based on spinal axial MRI. Type LI LM often occurs in patients with intracranial and intraspinal tumors found simultaneously. Patients who receive surgery for intracranial tumors may present with type N LM. Surgery is suitable for patients with NI LM and LIIb LM in stages III–IV, presenting with severe spinal symptoms. The prognosis is better for type N LM than type L LM.
    Chinese Science Bulletin 57(22). · 1.37 Impact Factor