Hong Wan

Capital Medical University, Peping, Beijing, China

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Publications (29)38.34 Total impact

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    ABSTRACT: The aim of this study was to determine the effectiveness of hypoglossal-facial nerve "side"-to-end (HemiHN-FN) and accessory-facial nerve end-to-end (AN-FN) neurorrhaphy using a predegenerated nerve graft (PNG) for reanimating facial paralysis in a rat FN injury model. A total of 25 rats with complete unilateral facial paralysis resulting from section of the right FN were divided into 5 groups (n=5 each) that were submitted to immediate, delayed (3months after FN injury) or no (control) FN reconstruction procedures involving HemiHN-FN or AN-FN neurorrhaphy. Approximately 3months after FN reconstruction, cholera toxin subunit B conjugate Alexa 555 (CTB-Alexa 555) was injected into the ipsilateral whisker pad muscle and CTB-Alexa 555-labeled neurons were observed in the hypoglossal or accessory nuclei of all the FN reconstruction rats, but none of these neurons were found in the controls. There were numerous myelinated and nonmyelinated axons in both PNG and repaired FN of the FN reconstruction rats. No differences were found for these numbers between the two neurorrhaphy methods for each of the treatment time points, indicating the equal effectiveness of axon regeneration. However, a significantly higher number of CTB-Alexa 555-labeled neurons was observed in the hypoglossal nucleus of the immediate HemiHN-FN neurorrhaphy-treated rats when compared to that in the accessory nucleus of the immediate AN-FN neurorrhaphy-treated rats, consistent with the surface values of the recorded MAPs at the whisker pad muscle while electro-stimulating the FN. These results suggest that HemiHN-FN neurorrhaphy produces more efficient innervation of the paralyzed facial muscles than AN-FN neurorrhaphy without sacrificing ipsilateral hypoglossal function. Taking into consideration the clinical relevance of these findings for postoperative complications and functional reanimation in relation to the central plasticity, we suggest that HemiHN-FN neurorrhaphy may be the preferable facial reanimation procedure after an FN injury. Copyright © 2014 Elsevier B.V. All rights reserved.
    Journal of the neurological sciences. 10/2014; 347(1-2):235-241.
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    ABSTRACT: Hypoglossal-facial nerve (HN-FN) neurorrhaphy is a method commonly used to treat facial palsy when the proximal stump of the injured FN is unavailable. Since the classic HN-FN neurorrhaphy method that needs to section the injured FN is not suitable for incomplete facial palsy, we investigated a modified method that consists of HN-FN 'side'-to-side neurorrhaphy, retaining the remaining or spontaneously regenerated FN axons while preserving hemihypoglossal function.
    Journal of neurology, neurosurgery, and psychiatry. 09/2014;
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    ABSTRACT: Skull base chordoma is a rare tumor with unknown risk factors. Werner syndrome, which is caused by a mutation in the WRN gene, is a disease of progeria, resembling the pathological process of aging. The present study aimed to provide data on the possible association between skull base chordoma and the single-nucleotide polymorphism (SNP) rs1346044 of the WRN gene. Between July, 2010 and September, 2012, a total of 65 patients with pathologically confirmed skull base chordoma and 65 control subjects were enrolled in this case-control study. The clinical data of the skull base chordoma patients were documented and the rs1346044 site in all the enrolled subjects was analyzed by sequencing and statistically compared using SPSS software. The A allele was the dominant allele of the rs1346044. The comparisons of genotype distributions and allele frequencies did not reveal any significant difference between the groups [P=0.383, 95% confidence interval (CI): 0.346-1.505]. The clinicopathological factors were assessed and no statistically significant difference was observed. In conclusion, the present study suggested that there is no association between rs1346044 SNP and skull base chordomas, at least in the population analyzed.
    Biomedical reports. 07/2014; 2(4):521-524.
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    ABSTRACT: Non-functioning pituitary adenomas (NFPAs) may be locally invasive. Surgery is a treatment option, but unlike the case for functional pituitary adenomas, there are almost no drug treatments available for NFPAs. Markers of invasiveness are needed to guide therapeutic decision-making and identify potential adjuvant drugs. Owing to the highly heterogeneous nature of NFPAs, little is known regarding the subtype-specific gene expression profiles associated with invasiveness. To identify important biomarkers of invasiveness, we selected 23 null cell adenomas and 20 oncocytomas. These tumors were classified as invasive or non-invasive adenomas based on magnetic resonance imaging, pathology slides and surgical findings. Firstly, we observed that there were significant differences in expression between invasive (n = 3) and non-invasive (n = 4) adenomas by gene expression microarray. A total of 1,188 genes were differentially expressed in the invasive and non-invasive adenomas. Among these 1,188 genes, 578 were upregulated and 610 were downregulated in invasive adenomas. Secondly, the expression of ENC1, which displayed the significant alterations, was further confirmed by qRT-PCR and Western blot analysis in all 43 tumor samples and three normal pituitary glands. Low levels of ENC1 were found in tumor samples, while high levels were detected in normal pituitary glands. Interestingly, the ENC1 expression level was low in invasive null cell adenomas compared with non-invasive adenomas, but this relationship was not observed in invasive oncocytomas. Immunohistochemistry also demonstrated that the staining of ENC1 was different between invasive and non-invasive null cell adenomas. In addition, bioinformatics studies, including gene ontology and protein interaction analyses, were also performed to better understand the critical role of ENC1 in the development and progression of null cell adenomas and oncocytomas. Consequently, ENC1 may be an important biomarker for null cell adenomas and oncocytomas, and it is specific to invasive null cell adenomas.
    Journal of Neuro-Oncology 06/2014; · 3.12 Impact Factor
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    ABSTRACT: Gliomas arising in the brainstem and thalamus are devastating tumors that are difficult to surgically resect. To determine the genetic and epigenetic landscape of these tumors, we performed exomic sequencing of 14 brainstem gliomas (BSGs) and 12 thalamic gliomas. We also performed targeted mutational analysis of an additional 24 such tumors and genome-wide methylation profiling of 45 gliomas. This study led to the discovery of tumor-specific mutations in PPM1D, encoding wild-type p53-induced protein phosphatase 1D (WIP1), in 37.5% of the BSGs that harbored hallmark H3F3A mutations encoding p.Lys27Met substitutions. PPM1D mutations were mutually exclusive with TP53 mutations in BSG and attenuated p53 activation in vitro. PPM1D mutations were truncating alterations in exon 6 that enhanced the ability of PPM1D to suppress the activation of the DNA damage response checkpoint protein CHK2. These results define PPM1D as a frequent target of somatic mutation and as a potential therapeutic target in brainstem gliomas.
    Nature genetics. 06/2014;
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    ABSTRACT: Object Hypoglossal-facial nerve neurorrhaphy is a widely used method for treating complete facial palsy. However, the classic surgical procedure using a "side"-to-end neurorrhaphy is not suitable for incomplete facial palsy (IFP), because sectioning of the facial nerve for neurorrhaphy compromises remnant axons and potential spontaneous reinnervation. For the treatment of persistent IFP, the authors investigated in rats a modified method using hypoglossal-facial nerve "side"-to-side neurorrhaphy. Methods An IFP model was created by crushing the facial nerve and then ligating the injury site to limit axonal regeneration. After 9 weeks, rats with IFP were submitted to hypoglossal-facial nerve "side"-to-side neurorrhaphy: The gap between the 2 nerves was bridged with a predegenerated peroneal nerve graft, which was sutured to only one-half of the hypoglossal nerve and to the remnant facial nerve through a small window created by removing the epineurium, thus preserving regenerating facial axons. Results Four months after repair surgery, double innervation of the target whisker pad by hypoglossal and facial motor neurons was supported by the recording of muscle action potentials and their retrograde labeling. Regenerated hypoglossal and facial motor neurons effectively participated in the reinnervation of the whisker pad, significantly improving facial symmetry without evident synkinesis, compared with rats that underwent IFP without hypoglossal-facial nerve neurorrhaphy. Conclusions This study demonstrates that hypoglossal-facial nerve "side"-to-side neurorrhaphy with a predegenerated nerve graft can lead to rapid functional benefits for persistent IFP without compromising the remnants of facial axons, thus providing a proof-of-feasibility for further studies in humans.
    Journal of Neurosurgery 11/2013; · 3.15 Impact Factor
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    ABSTRACT: Clinical studies have shown that gliomas of the brainstem behave differently in children and adults. The aim of the present study was to compare and analyze the differences between these gliomas in juvenile and adult rats with regard to tumor growth, survival, pathology and magnetic resonance imaging (MRI). A total of 25 juvenile and 25 adult Wistar rats were divided into groups A (15 juvenile rats), B (10 juvenile rats), C (15 adult rats) and D (10 adult rats). The rats of groups A and C (experimental) were injected with glioma cells, while groups B and D (control) were injected with a physiological saline solution. Rat neurological signs, survival time, tumor size, hematoxylin and eosin (HE) staining and immunohistochemical staining for MMP-2, MMP-9 and β-catenin were compared. The survival time of group A was 19.47±2.232 days, whereas that of group C was 21.47±2.232 days (P<0.05). The tumor sizes were 4.55 and 4.62 mm (P>0.05) in groups A and C, respectively. HE and immunohistochemical staining revealed no differences between the groups. The results suggest that the growth patterns and invasiveness of brainstem gliomas may vary in children compared with adults due to the varied biological behaviors of the tumor cells.
    Oncology letters 07/2013; 6(1):246-250. · 0.24 Impact Factor
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    ABSTRACT: Background: The overall prognosis of brainstem gliomas is very poor, and the current treatment cannot significantly prolong the overall survival of these patients; therefore, studying the molecular biological mechanisms of the occurrence and development of brainstem gliomas has important significance for their treatment. The Wnt/β-catenin signaling pathway is closely associated with the occurrence and development of tumors, but its relationship with brainstem gliomas remains unclear. Methods: This study used Western blot and immunohistochemistry methods to detect the expressions of Wnt/β-catenin signaling pathway-related components such as Wnt-1, Wnt-2, β-catenin and C-myc in six cases of normal brain tissues and 24 cases of brainstem gliomas and analyzed the relationship between their expressions and clinicopathological characteristics. Results: Wnt-1 had no obvious expression in normal brain tissues and did not show any significant difference between high- and low-grade brainstem gliomas; the expressions of Wnt-2, β-catenin and C-myc in high-grade brainstem gliomas were significantly higher than that in low-grade brainstem gliomas and normal brain tissues and were positively correlated with the expression of Ki-67. Moreover, the expressions of Wnt-2 and C-myc were significantly associated with the prognosis of brainstem glioma patients; additionally, there was a trend toward increased β-catenin expression with shorter survival, but there was no statistical difference. Conclusions: Wnt/β-catenin signaling pathway might be abnormally activated and plays an important role in the occurrence and development of brainstem gliomas. Wnt-2, β-catenin and C-myc may be potential targets for brainstem glioma treatment.
    The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques 05/2013; 40(3):355-60. · 1.33 Impact Factor
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    ABSTRACT: Object Facial nerve injury results in facial palsy that has great impact on the psychosocial conditions of affected patients. Reconstruction of the facial nerve to restore facial symmetry and expression is still a significant surgical challenge. In this study, the authors assessed a hypoglossal-facial nerve anastomosis method combined with neurotrophic factor gene therapy to treat facial palsy in adult rats after facial nerve injury. Methods Surgery consisted of the interposition of a predegenerated nerve graft (PNG) that was anastomosed with the hypoglossal and facial nerves at each of its extremities. The hypoglossal nerve was cut approximately 50% for this anastomosis to conserve partial hypoglossal function. Before their transplantation, the PNGs were genetically engineered using lentiviral vectors to induce overexpression of the neurotrophic factor neurotrophin-3 (NT-3) to improve axonal regrowth in the reconstructed nerve pathway. Reconstruction was performed after facial nerve injury, either immediately or after a delay of 9 weeks. The rats were followed up for 4 months postoperatively, and treatment outcomes were then assessed. Results Compared with the functional innervation in control rats that underwent facial nerve injury without subsequent treatment, functional innervation of the paralyzed whisker pad by hypoglossal motoneurons in rats treated 4 months after nerve reconstruction was evidenced by the retrograde transport of neuronal tracers, the recording of muscle action potentials conducted by the PNG, and the recovery of facial symmetry. Although a better outcome was observed when reconstruction was performed immediately after facial nerve injury, reconstruction with NT3-treated PNGs significantly improved functional reinnervation of the paralyzed whisker pad even when implantation occurred 9 weeks posttrauma. Conclusions Results demonstrated that hypoglossal-facial nerve anastomosis facilitates innervation of paralyzed facial muscle via hypoglossal motoneurons without sacrificing ipsilateral hemitongue function. Neurotrophin-3 treatment through gene therapy could effectively improve such innervation, even after delayed reconstruction. These findings suggest that the combination of surgical reconstruction and NT-3 gene therapy is promising for its potential application in treating facial palsy in humans.
    Journal of Neurosurgery 04/2013; · 3.15 Impact Factor
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    ABSTRACT: BACKGROUND: Various tissue engineering strategies have been developed to facilitate axonal regeneration after spinal cord injury. This study aimed to investigate whether neural stem cells (NSCs) could survive in poly(L-lactic-co-glycolic acid) (PLGA) scaffolds and, when cografted with Schwann cells (SCs), could be induced to differentiate towards neurons which form synaptic connection and eventually facilitate axonal regeneration and myelination and motor function. METHODS: NSCs and SCs which were seeded within the directional PLGA scaffolds were implanted in hemisected adult rat spinal cord. Control rats were similarly injured and implanted of scaffolds with or without NSCs. Survival, migration, differentiation, synaptic formation of NSCs, axonal regeneration and myelination and motor function were analyzed. Student's t test was used to determine differences in surviving percentage of NSCs. One-way analysis of variance (ANOVA) was used to determine the differences in the number of axons myelinated in the scaffolds, the mean latency and amplitude of cortical motor evoked potentials (CMEPs) and Basso, Beattie & Bresnahan locomotor rating scale (BBB) score. The χ(2) test was used to determine the differences in recovery percentage of CMEPs. RESULTS: NSCs survived, but the majority migrated into adjacent host cord and died mostly. Survival rate of NSCs with SCs was higher than that of NSCs without SCs ((1.7831 ± 0.0402)% vs. (1.4911 ± 0.0313)%, P < 0.001). Cografted with SCs, NSCs were induced to differentiate towards neurons and might form synaptic connection. The mean number of myelinated axons in PLGA + NSCs + SCs group was more than that in PLGA + NSCs group and in PLGA group ((110.25 ± 30.46) vs. (18.25 ± 3.30) and (11.25 ± 5.54), P < 0.01). The percentage of CMEPs recovery in PLGA + NSCs + SCs group was higher than in the other groups (84.8% vs. 50.0% and 37.5%, P < 0.05). The amplitude of CMEPs in PLGA + NSCs + SCs group was higher than in the other groups ((1452.63 ± 331.70) µV vs. (428.84 ± 193.01) µV and (117.33 ± 14.40) µV, P < 0.05). Ipsilateral retransection resulted in disappearance again and functional loss of CMEPs for a few days. But contralateral retransection completely damaged the bilateral motor function. CONCLUSIONS: NSCs can survive in PLGA scaffolds, and SCs promote NSCs to survive and differentiate towards neurons in vivo which even might form synaptic connection. The scaffolds seeded with cells facilitate axonal regeneration and myelination and motor function recovery. But regenerating axons have limited contribution to motor function recovery.
    Chinese medical journal 03/2013; 126(5):909-917. · 0.90 Impact Factor
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    ABSTRACT: A recent chordoma cancer genotyping study reveals that the rs2305089, a single nucleotide polymorphism (SNP) located in brachyury gene and a key gene in the development of notochord, is significantly associated with chordoma risk. The brachyury gene is believed to be one of the key genes involved in the pathogenesis of chordoma, a rare primary bone tumor originating along the spinal column or at the base of the skull. The association between the brachyury Gly177Asp single nucleotide polymorphism (SNP) and the risk of skull base chordoma in Chinese populations is currently unknown. We investigated the genotype distribution of this SNP in 65 skull-base chordoma cases and 120 healthy subjects. Comparisons of the genotype distributions and allele frequencies did not reveal any significant difference between the groups. Our data suggest that the brachyury Gly177Asp SNP is not involved in the risks of skull-base chordoma, at least in the Chinese population.
    International Journal of Molecular Sciences 01/2013; 14(11):21258-21265. · 2.46 Impact Factor
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    ABSTRACT: Abstract Brainstem gliomas are usually associated with serious dysfunction and poor prognosis especially for diffuse intrinsic brainstem gliomas, however the reasons are still unclear. Some clinical studies have suggested that the invasive ability may be different among brainstem gliomas, and the dysfunction of β-catenin and E- and N-cadherin appears to be connected with tumor invasion and progression. In this study, the expression of β-catenin and E- and N-cadherin was detected in 40 brainstem glioma samples using immunochemistry and was further analyzed in 18 samples using reverse transcription-polymerase chain reaction. The clinicopathological characteristics were also analyzed. The results show that there was no obvious staining for E-cadherin, but weak expression at the mRNA level could be seen in a few samples. The protein and mRNA expression levels of β-catenin and N-cadherin were significantly associated with the pathological grades of brainstem gliomas. No significant differences in the expression levels of β-catenin and N-cadherin were observed for age, sex, location, or diffuse growing pattern. The overall survival of patients with low β-catenin expression was longer than that with high β-catenin expression, and there was a trend toward increased expression of N-cadherin with shorter survival, however both of them had no statistical differences. These results demonstrate that expression of β-catenin and N-cadherin is associated with the malignant progression of brainstem gliomas but not correlated with the diffuse and invasive growing pattern. β-catenin and N-cadherin are potential therapeutic targets and prognostic markers for brainstem glioma, which need to be validated in a larger patient cohort.
    The International journal of neuroscience 12/2012; · 0.86 Impact Factor
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    ABSTRACT: Direct or ex vivo BMP9 adenoviral gene therapy can induce massive bone formation at the injection sites and clearly promote spinal fusion. A comprehensive analysis of the osteogenic activity indicated that BMP9 was one of the most potent inducers of osteogenic differentiation both in vitro and in vivo among 14 types of human BMPs. However, genetic variations and whether they correlated with OPLL were not considered. We have sequenced the complete BMP9 gene in 450 patients with OPLL and in 550 matched controls. Analyses were performed on single markers and haplotypes. Single marker tests identified 6 SNPs, among which the minor alleles of rs7923671 (T>C; P=0.0026; OR: 1.33, CI: 1.10-1.60), rs75024165 (C>T, Thr304Met; P<0.001; OR: 1.76, CI: 1.47-2.12) and rs34379100 (A>C; P<0.001; OR: 1.52, CI: 1.27-1.82) were associated with OPLL. Logistic regression analysis showed that the additive model of rs75024165 (TT vs. CT vs. CC; P<0.001; OR: 1.74) and rs34379100 (CC vs. AC vs. AA; P=0.003; OR: 1.95) retained statistical significance when adjusted for clinical and demographic characteristics. Linkage disequilibrium (LD) analysis identified one 3 kb block of intense LD in BMP9 and one specific haplotype, CTCA (P<0.001; OR: 2.37), that contained the OPLL-associated risk alleles and was a risk factor for OPLL. This haplotype is associated with increased severity of OPLL, as shown by the distribution of ossified vertebrae in patients with OPLL (P=0.001). In summary, in the Chinese population studied, SNPs in the BMP9 gene appear to contribute to the risk of OPLL in association with certain clinical and demographic characteristics. The severity of OPLL seems to be mediated predominantly by genetic variations in a 3kb BMP9 locus with the specific haplotype CTCA.
    PLoS ONE 01/2012; 7(7):e40587. · 3.53 Impact Factor
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    ABSTRACT: Previous genome-wide microarray analysis of candidate genes involved in the ossification of the posterior longitudinal ligament (OPLL) of the spine resulted in the identification of a novel, clinically relevant gene encoding bone morphogenetic protein 4 (BMP4) but was defined only by its expression patterns. The complete genomic BMP4 coding DNA from 450 patients with OPLL and 550 matched controls were sequenced and compared. We identified 18 SNPs, among which the minor alleles of SNP8 (C>T; p < 0.001; OR: 1.58), SNP13 (rs17563C>T; p < 0.001; OR: 1.76), and SNP14 (rs76335800A>T; p < 0.001; OR: 1.68) were associated with OPLL. Logistic regression analysis showed that the additive model of SNP8 (p < 0.001; OR: 3.48), SNP13 (p < 0.001; OR: 2.22), and SNP14 (p < 0.001; OR: 1.99) retained statistical significance. Linkage disequilibrium (LD) analysis identified a 3-kbp block of intense LD in BMP4 and 1 specific haplotype, TGGGCTT (p < 0.001, OR: 2.54), which was associated with OPLL-associated risk alleles and increased severity of OPLL, as shown by the distribution of ossified vertebrae in patients with OPLL (p = 0.002). Novel mutations in the BMP4 gene and a specific haplotype TGGGCTT appear to contribute to the risk of developing OPLL. Also the severity of OPLL seems to be mediated predominantly by genetic variations in this specific BMP4 gene region, but might be associated with other certain clinical and demographic characteristics in the Chinese population studied.
    Journal of Orthopaedic Research 11/2011; 30(5):748-56. · 2.88 Impact Factor
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    ABSTRACT: Studies have shown that abnormal activation of the sonic hedgehog pathway is closely related to tumorigenesis in central nervous system. This study aimed to investigate the role of the sonic hedgehog signaling pathway in the occurrence of brainstem and supratentorial glioma. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to detect the expression of sonic hedgehog-related components in 5 specimens of normal brain tissue, 10 of grade II brainstem glioma, and 10 of grade II supratentorial glioma. The significance of differences between two groups was determined using the Mann-Whitney U test or the two-sample test according to the results of normality distribution tests. The mRNA expression levels of sonic hedgehog-related genes were higher in brainstem astrocytomas than in supratentorial astrocytomas and normal brain tissue. The level of protein patched homolog 1 (PTCH1) was significantly higher in brainstem astrocytomas than in supratentorial astrocytomas and normal brain tissue (P < 0.01). Immunohistochemistry semi-quantitative analysis was consistent with the qRT-PCR result that PTCH1 expression was increased significantly in brainstem astrocytomas at the protein level (P < 0.05). Enhanced PTCH1 expression and activation of the sonic hedgehog pathway are involved in brainstem glioma. This may be related to the difference in malignant biological behavior between brainstem and hemispheric glioma, and could be an ideal therapeutic target in brainstem glioma.
    Chinese medical journal 11/2011; 124(21):3515-20. · 0.90 Impact Factor
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    ABSTRACT: The most important objective of transplant studies in the injured spinal cord has been to provide a favorable environment for axonal growth. Moreover, the continuing discovery of new grafts is providing new potentially interesting transplant candidates. Our purpose was to observe the morphological and functional repair effects of the co-transplantation of neural stem cell (NSC), Schwann cells (SCs) and poly lactide-co-glycolide acid (PLGA) on the spinal cord injury of rats. A scaffold of PLGA was fabricated. NSCs and SCs were cultured, with the NSCs labeled with 5-bromodeoxyuridine, and the complex of NSC/PLGA or NSC + SCs/PLGA were constructed. Thirty-six Wistar rats were randomly divided into three groups: group A (transplantation of PLGA), group B (transplantation of NSC/PLGA) and group C (transplantation of NSC + SCs/PLGA). The 3 mm length of the right hemicord was removed under the microscope in all rats. The PLGA or the complex of PLGA-cells were implanted into the injury site. Basso-Beattie-Bresnahan (BBB) locomotion scores, motor and somatosensory evoked potential of lower limbs were examined to learn the rehabilitation of sensory and motor function at 4 weeks, 8 weeks, 12 weeks and 24 weeks after injury. All the recovered spinal cord injury (SCI) tissues were observed with HE staining, immunohistochemistry, and transelectronmicroscopy to identify the survival, migration and differentiation of the transplanted cells and the regeneration of neural fibres at 4 weeks, 8 weeks, 12 weeks and 24 weeks after injury. (1) From 4 weeks to 24 weeks after injury, the BBB locomotion scores of cell-transplanted groups were better than those of the non-cell-transplanted group, especially group C (P < 0.05). The amplitudes of the somatosensory evoked potential (SEP) and motor-evoked potential (MEP) were improved after injury in groups B and C, but the amplitude of SEP and MEP at 4 weeks was lower than that at 12 weeks and 24 weeks after injury. Compared with group B, the amplitude of SEP and MEP in group C was improved. The amplitude of SEP and MEP was not improved after injury in group A. (2) HE staining revealed the volume of the scaffold decreased and the number of cells in the scaffold increased. Newly-grown capillaries also could be seen. Immunohistochemistry staining showed the transplanted NSCs could survive and migrate until 24 weeks and they could differentiate into neurons and oligodendrocytes. The regenerated axons were observed in the scaffold-cell complex with transelectronmicroscopy. The above manifestations were more extensive in group C. The transplanted NSC can survive and migrate in the spinal cord of rats up to 24 weeks after injury, and they can differentiate into various neural cells. Co-transplantation of cells/PLGA can promote the functional recovery of the injured spinal cord. The effect of co-transplanting NSC + SCs/PLGA is better than transplanting NSC/PLGA alone.
    Chinese medical journal 09/2010; 123(17):2424-31. · 0.90 Impact Factor
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    ABSTRACT: It is generally known that low-intensity pulsed ultrasound (LIPUS) accelerates peripheral nerve tissue regeneration. However, the precise cellular mechanism involved is still unclear. The purpose of this study was to determine how the Schwann cells respond directly to LIPUS stimuli. Thus, we investigated the effect of LIPUS on cell proliferation, neurotrophin-3 (NT-3), and brain-derived neurotrophic factor (BDNF) mRNA expression in rat Schwann cells. Schwann cells were enzymatically isolated from postnatal 1-3 day rat sciatic nerve tissue and cultured in the six-well plate. The ultrasound was applied at a frequency of 1 MHz and an intensity of 100 mW/cm(2) spatial average temporal average for 5 minutes/day. The control group was cultured in the same way but without the administration of ultrasound. Immunohistochemistry demonstrated that more than 98% of the experimental and control cells were positive for S-100, NT-3, and BDNF. With 5-bromo-2'-deoxyuridine (BrdU) assay, the stimulated cells also exhibited an increase in the rate of cell proliferation on days 4, 7, 10, and 14. Further investigation found that mRNA expression of NT-3 was significantly upregulated in experimental groups compared with the control 14 days after the LIPUS stimulation (the ratio of NT-3/beta-actin was 0.56 +/- 0.13 vs. 0.41 +/- 0.09, P < 0.01), whereas the mRNA expression of BDNF was significantly downregulated in experimental groups compared with the control (the ratio of BDNF/beta-actin was 0.51 +/- 0.05 vs. 0.60 +/- 0.08, P < 0.05). These results demonstrated that the application of LIPUS promotes cell proliferation and NT-3 gene expression in Schwann cells, and involved in the alteration of BDNF gene expression.
    Microsurgery 04/2009; 29(6):479-85. · 1.62 Impact Factor
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    ABSTRACT: To investigate the recovery of rat transected spinal cord injury after implantation of Schwann cells combined with poly (lactide-co-glycolide) (PLGA). Schwann cells were expanded, co-cultured with PLGA for 9 days in vitro, and then analyzed with scanning electron microscope (SEM). Rat spinal cord at the level of T(9) was transected. Schwann cells labeled with BrdU and PLGA scaffold were implanted to injury site. After 1, 3, 6 months, BrdU/MBP immunohistochemistry double staining, semi-thin sections stained thionin and ultra-thin section were performed to investigate myelin renew. BBB open field locomotion, motor evoked potential (MEP), compound muscle action potential (CMAP) and somatosensory evoked potential (SEP) were recorded. Schwann cells grew well on PLGA under SEM. BrdU/MBP double positive cells would been seen, remyelination was thin and formed by Schwann cells at 6 months later under electron microscope (EM). BBB behavioral tests revealed no significant difference in recovery comparing with experiment group and control group. The results of MEP, CMAP and SEP showed no significant improvement in the conduction of spinal cord. There are the compatibility between Schwann cells and PLGA. Although remyelination was found in morphology, function conduction of spinal cord failed to be established.
    Zhonghua wai ke za zhi [Chinese journal of surgery] 07/2007; 45(12):843-6.
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    ABSTRACT: To investigate whether there is neogenesis of myelin sheath and neuron after transplantation of Schwann cells into cerebral hemorrhage lesion. Schwann cells were expanded, labeled with BrdU in vitro and transplanted into rat cerebral hemorrhage with blood extracted from femoral artery and then injected into the basal nuclei. Double immunohistochemistry staining and electron microscopy were used to detect the expression of BrdU/MBP and BrdU/GAP-43 and remyelination. BrdU/MBP double positive cells could be seen at 1 week up to 16 weeks after transplantation of Schwann cells. Thin remyelination was observed under electron microscope. GAP-43 positive cells appeared after 12 weeks and were found more in Hippocamp. Grafted Schwann cells participate in remyelination and promoter nerve restore in rat cerebral hemorrhage.
    Biomedical and Environmental Sciences 03/2007; 20(1):47-51. · 1.15 Impact Factor
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    ABSTRACT: To analyze the upstream region of radiation-induced junB gene. Four plasmids containing 250 bp, 590 bp, 900 bp and 1650 bp, and CAT reporter gene were constructed separately and introduced to L8704 cells. The cells were irradiated with 2 Gy X-rays and incubated at different intervals. Total RNA was extracted from the cells and fluctuation of the CAT mRNA level was assessed by the RNA ratio of CAT/beta-actin measured by quantitative Northern blot hybridization. CAT mRNA expression containing 900 bp and 1560 bp junB promoter remarkably and rapidly increased, and reached its peak 30 min after 2 Gy X-ray irradiation. 590-900 bp fragments located in the upstream region of junB gene play an important role in the early process of cells against radiation.
    Biomedical and Environmental Sciences 07/2006; 19(3):210-3. · 1.15 Impact Factor

Publication Stats

124 Citations
38.34 Total Impact Points

Institutions

  • 2013–2014
    • Capital Medical University
      • Department of Neurosurgery
      Peping, Beijing, China
    • Beijing Tiantan Hospital
      Peping, Beijing, China
  • 2003–2013
    • Beijing Neurosurgical Institute
      Peping, Beijing, China