Approach selection and outcomes of craniopharyngioma resection: a single-institute study.

Since there are many approaches for successful craniopharyngioma resection, how to choose a suitable approach remains problematic. The aim of this study was to summarize experience of approach selection and outcomes of craniopharyngioma resection in our institute. The data of 182 primary craniopharyngiomas between January 2013 and June 2019 were retrospectively reviewed. Craniopharyngiomas were classified into intrasellar, intra-suprasellar, suprasellar, and intra-third ventricle types based on the location. The surgical approaches, extent of resection, endocrine and ophthalmological outcomes, and complications were evaluated. Gross total resection (GTR) was achieved in 158 (86.8%) patients, near-total resection (NTR) in 20 (11%), and partial resection (PR) in 4 (2.2%). New-onset hypopituitarism occurred in 90 (49.5%) and new-onset diabetes insipidus in 48 (26.4%). Visual function was improved in 110 of the 182 patients, unchanged in 52, and deteriorated in 20. For intra-suprasellar and suprasellar tumors, patients in the endoscopic endonasal approach (EEA) group had higher GTR rate, lower incidence of new-onset hypopituitarism, and better visual outcome than patients in transcranial approach group, but no significant difference in the incidence of new-onset diabetes insipidus was found. There were no surgery-related deaths, and the common complications included permanent oculomotor nerve palsy, hemorrhage, and cerebrospinal fluid leaks. During the follow-up period, tumor recurrence or regrowth occurred in 6.6% of the cases. Tumor location is key for choosing an optimal surgical approach for craniopharyngioma resection. The EEA should be considered as the first choice for intra-suprasellar and suprasellar craniopharyngiomas to achieve better visual outcomes and fewer pituitary hormonal disorders.

The absence of PRDM2 involved the tumorigenesis of somatotroph adenomas through regulating c-Myc.

Somatotroph adenoma is the main cause of acromegaly which have peripheral signs with growth of soft tissues and multiple comorbidities. Surgery and adjuvant therapy with somatostatin analogs (SSA) fail in more than 25% of patients. PRDM2, a tumor suppressor, plays an important role in cancer and obesity, including pituitary adenomas. In this study, we analyze the correlation of PRDM2 and oncogene c-Myc in 70 somatotroph adenomas according immunohistochemical staining, furthermore, we probed that whether PRDM2 participates in c-Myc signaling pathway in vitro experiment. 70 somatotroph adenomas patients were divided into low patients and high patients according to median of H-score of PRDM2 or c-Myc. Low PRDM2 patients had higher risk of invasive behavior, larger tumor volume and recurrence chance than high PRDM2 group (P = 0.015, P = 0.031, P = 0.017). High c-Myc patients had higher risk of invasive behavior, larger tumor volume and recurrence chance than low c-Myc group (P = 0.012, P = 0.002, P = 0.015). It was a negative correlation between H-score of PRDM2 and c-Myc (PRDM2 = -0.163 × c-Myc + 67.11, r = -0.407). The ability of cell proliferation was declined in a time dependent manner after overexpression of PRDM2 (PRDM2 group) compared to that in control GH3 cells (P < 0.05). Through flow cytometry assay, PRDM2 could induce the apoptosis and G2/M arrest in GH3 cell (both p < 0.05). Transwell experiment proved less trans-membrane cells in PRDM2 group than those in control group (415 ± 76 vs 145 ± 37, P < 0.01). RT-PCR and western blot both proved PRDM2 could inhibit the level c-Myc and elevate the levels of CDKN1A and CDKN1B. Combined with c-Myc inhibitor 10058-F4, PRDM2 further inhibited cell proliferation and induced more apoptosis in GH3 cell. Taken together, we found that PRDM2 negatively regulated the expression of c-Myc in somatotroph adenomas, and testified the synergism between PRDM2 gene therapy and c-Myc inhibitor in vitro experiment.

Detection of circulating tumor cells in patients with pituitary tumors.

BACKGROUND: Circulating tumor cells (CTCs) are tumor cells that have shed from a primary tumor and circulate in the peripheral blood. Recent experimental and clinical studies show that CTCs can be detected in early-stage disease. CASE PRESENTATION: We report three cases of pituitary adenoma (PA) in which tumor cells with particles were detected in the interstitial vascular compartment by transmission electron microscopy. Tumors were completely resected. Immunohistochemical analysis showed a ß-catenin score of 10.5 ± 1.5 in the three cases with CTCs compared with 2.4 ± 0.5 in 24 control adenomas. The Ki-67 labeling index was 2.1 ± 0.7 in CTCs vs. 0.2 ± 0.3 in control cases (p = 0.043), and the p53 score was 4.33 ± 1.3 vs. 0.31 ± 0.17 (p = 0.000). The E-cadherin score did not differ significantly between the two groups. CONCLUSIONS: CTCs can be detected in benign tumors such as PAs and not only in late-stage malignant tumors with apparent distant metastases. The present findings suggest that pituitary carcinomas develop from adenomas.

Aberrant expression of the sFRP and WIF1 genes in invasive non-functioning pituitary adenomas.

Non-functioning pituitary adenomas (NFPAs) are the most common pituitary tumors and mainly invade the sphenoid, cavernous sinus or dura mate. Aberrant regulation of the Wnt signaling pathway plays an important role in tumorigenesis. This study was designed to investigate the relationships between secreted frizzled-related proteins (sFRPs), WIF1 genes and the invasion of NFPAs by tissue microassays (TMAs) of samples from 163 patients. Significantly weaker staining of WIF1 and sFRP4 were detected in the invasive group compared with the non-invasive group by TMAs (p = 0.002, p < 0.001). Univariate analysis showed a significant correlation between tumor invasion and low expression of WIF1 and sFRP4 (p = 0.002, p < 0.001). A similar trend was observed when analyzing the mRNA and protein levels through RT-PCR and western blot experiments. Methylation of the WIF1 promoter was significantly increased in invasive NFPAs compared with the noninvasive group (p = 0.004). The average progression free survival time in the high WIF1 group was longer than that in the low WIF1 group (p = 0.025). Furthermore, RT-PCR measured the levels of 11 miRNAs targeting WIF1 according to the Targetscan database and PubMed. The levels of miRNA-137, miRNA-374a-5p and miRNA-374b-5p in the invasive group were 0.037-fold, 0.577-fold and 0.44-fold that of the noninvasive group (p = 0.003, p = 0.049 and p = 0.047). Overexpression of miRNA-137 could inhibit the proliferation and invasion of GH3 cells through cell viability and Transwell experiments (p < 0.05). Furthermore, the WIF1 level was upregulated after overexpression of miRNA-137 compared with miRNA-137-NC (control miRNA) in GH3 cells. Our data suggest that WIF1 may be potential biomarker for the aggressiveness of NFPAs. miRNA-137 plays an important role in the Wnt signaling pathway by affecting promoter methylation of WIF1.

Endoscopic Treatment of an Adult with Tegmental Astrocytoma Accompanied by Cerebrospinal Fluid Dissemination

Midbrain gliomas are relatively rare neoplasms with a generally benign prognosis, with dissemination or metastasis not previously reported. We describe here a woman, in whom magnetic resonance imaging scans showed hydrocephalus and a tegmental lesion in the upper aqueduct. Endoscopic third ventriculostomy and biopsy were performed; during surgery, a second small lesion was observed in the infundibular recess. Histologically, the two lesions had the characteristics of low grade astrocytoma, suggesting that the midbrain astrocytoma may have been disseminated via the cerebral spinal fluid to the infundibular recess. Postoperatively this patient received radiotherapy for nearly one month. Although patients with these tumors are not usually administered adjunctive therapy, radiation and, combined modality therapy, including surgery, radiotherapy, and chemotherapy, may be beneficial in patients with midbrain gliomas with dissemination.

Malignant Transformation of Radiotherapy-Naïve Craniopharyngioma.

BACKGROUND: Craniopharyngioma is a rare benign intracranial neoplasm that is successfully managed with surgery or adjuvant radiotherapy. The malignant transformation of craniopharyngioma has seldom been reported. CASE DESCRIPTION: A 30-year-old woman presented with a 5-month history of amenorrhea and was admitted to the hospital. She underwent surgical resection for three times and died at last. MRI revealed a new solid component of craniopharyngioma. Pathologic examination revealed malignant changes in the craniopharyngioma. In addition, We analyzed the expression of Ki-67, p53, VEGF, and MMP-9 in this malignant case after the third operation and in samples from 9 benign craniopharyngiomas. Immunohistochemical analysis showed that the Ki-67 index was higher in malignant craniopharyngiomas (50%) compared with benign craniopharyngiomas (3.0% ± 1.5%; range, 1.0%-6.0%). The p53, MMP-9, and VEGF protein levels were higher in the malignant craniopharyngioma compared with the benign craniopharyngiomas. CONCLUSIONS: Patients with a high Ki-67 index and high p53, MMP-9, and VEGF protein levels and a new solid component of craniopharyngioma on MRI may benefit from aggressive treatment and close surveillance.

Protein phosphatase 2A is involved in the tyrosine hydroxylase phosphorylation regulated by α-synuclein.

α-Synuclein (α-Syn) plays a crucial role in the pathophysiology of Parkinson's disease (PD), the degeneration of dopaminergic neurons. Previous studies have shown that α-Syn regulates dopamine synthesis by binding to and inhibiting tyrosine hydroxylase (TH). In neurons, protein phosphatases (PPs) play a prominent role in directing signaling toward survival or degeneration. This study was to re-evaluate whether α-Syn could regulate the tyrosine hydroxylase phosphorylation by protein phosphatase-2A (PP2A) in dopaminergic MN9D cells and cortex neurons. Our data demonstrated for the first time that α-Syn stimulates PP2A activity and reduces phosphorylation of TH through regulating the methylation of PP2A in dopaminergic MN9D cells and primary cortex neurons. Increased PP2A activity and reduced phosphorylation of PP2A at Y307 (inactive form of PP2A) were observed in α-Syn overexpression dopaminergic cells (Syn) and primary cortex neurons, and the TH phosphorylation relieved by enhancing PP2A methylation in Syn group could be abated by using PP inhibitors, okadaic acid (OKA). OKA could reduce the cell damage and cell apoptosis induced by α-Syn. Thus our findings may provide an insight into the complicated pathogenesis of PD as well as some clues to the development of novel therapeutic strategies targeting at PP2A.

The expression of TGF-ß1, Smad3, phospho-Smad3 and Smad7 is correlated with the development and invasion of nonfunctioning pituitary adenomas.

BACKGROUND: Transforming growth factor ß (TGF-ß) signaling functions as a suppressor or a promoter in tumor development, depending on the tumor stage and type. However, the role of TGF-ß signaling in nonfunctioning pituitary adenomas (NFPAs) has not been explored. METHODS: TGF-ß1, Smad2, phospho-Smad2 (p-Smad2), Smad3, phospho-Smad3 (p-Smad3), Smad4, and Smad7 were detected in 5 cases of normal anterior pituitaries, 29 cases of invasive NFPAs, and 21 cases of noninvasive NFPAs by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemical analysis. RESULTS: The Smad3 and p-Smad3 protein levels gradually decreased from normal anterior pituitaries, noninvasive NFPAs, to invasive NFPAs. However, there were no significant differences in Smad2 (P = 0.122) and p-Smad2 protein levels (P = 0.101) or Smad2 mRNA level (P = 0.409). In addition, the TGF-ß1 mRNA level gradually decreased while the Smad7 mRNA level gradually increased from normal anterior pituitaries, noninvasive NFPAs, to invasive NFPAs. Furthermore, proliferating cell nuclear antigen (PCNA) mRNA level was markedly increased in invasive NFPAs compared to noninvasive ones (P < 0.01), and its level was negatively correlated with Smad3 mRNA level (P < 0.01). CONCLUSION: The activity of TGF-ß signaling may be restrained in NFPAs and is correlated with the development and invasion of NFPAs.

Impacts of Different Doses of Alcohol on Rat Endothelial Microparticles / 天津医药

Objective To discuss the impacts of different doses of alcohol on the level of microparticles (EMPs) of rat endothelial cells. Methods Sixty male SD rats were randomly allocated into four groups:high dose group (group A), me-dium dose group (group B), low dose group (group C) and the blank contrast group (group D). There were15 rats in each group. Rats were fed alcohol for 8 weeks. Flow cytometer was used to measure the level of circulating CD31+/CD42-EMPs in four groups, and which was compared with the alcohol dosage. Results Compared with group D, the level of circulating EMPs was significantly increased in group A and B (P＜0.05). There was no significant change in the level of circulating EMPs in group C (P>0.05). Conclusion The moderate and high doses of alcohol are harmful to the function of vascular en-dothelial cells in rats, which show a significant dose-effect relationship. The low dose of alcohol shows no effect on the func-tion of vascular endothelial cells in rats. The protective effect of alcohol needs further investigation.

Statistical analysis of scientific papers published by postgraduate in Beijing Neurosurgical Institute from 2001 to 2010 / 中华医学教育探索杂志

ObjectiveThe aim of this paper is to investigate more effective ways in postgraduate academic training and research management by analysis of the scientific papers published in graduate school period.MethodsThe categories,quantity and quality of the scientific papers published by postgraduate students in Beijing Neurosurgical Institute from 2001 to 2010 were analyzed statistically.ResultsThe quantity of papers published by postgraduate students has been stably improved year by year,and the quality of the papers has shown an obvious tendency of increasing.ConclusionsAn outstanding research capability of the whole institute,the strict demand of supervisors and the reasonable encouraging systems in scientific research management are all the guarantee of the improvement of academic research ability of postgraduate students in Beijing Neurosurgical Institute.

Clonal heterogeneity in differentiation potential of immortalized human mesenchymal stem cells in vitro and in vivo / 中国综合临床

Objective To study the clonal heterogeneity in differentiation potential of immortalized mesenchymal stem cells in vitro and in rive.Methods The monoclonal cell lines were performed with limiting dilution cloning,and were induced to adipocytic,asteogenic and neuronal differentiation in vitro.After transplanted the monoclonal cell lines into SCID mice,the xenotransplants were removed and evaluated by immunohistochemistry.Results From the parental HMSC-TERT,32 single-cell derived clones were established,of which the differentiation properties varied considerably in vitro.The cells grow in different plating densities during expansion in culture:HMSC-TERT-2 expressed more strongly in LCA,GFAP and vimemin;HMSC-TERT-C19 expressed more strongly in keratinose than HMSC-TERT-2,HMSC-IERT-20,and MSC-H;HMSC-TERT-C2 expressed more strongly in actin than HMSC-TERT-2.Conclusions The HMSC-TERT monoclone cells are heterogeneity in differentiation petential in vitro and in vivo,suggesting that standard in vitro culture and in vivo inoculate procedure phy an important role in the clinical application of stem cells.

Effects of Transplantation of Bone Marrow Stromal Cells on Expression of Vascular Endothelial Growth Factor after Local Brain Injury in Rats / 中国康复理论与实践

@#Objective To observe the effects of transplantation of bone marrow stromal cells(BMSCs)on expression of vascular endothelial growth factor(VEGF)after local brain injury in rats.Methods The animal model of local brain injury in rat was established.The human BMSCs(hBMSCs)were transplanted into the local brain.The immunohistochemistry,real-time quantitative PCR,and ELISA were used to observe the changes of VEGF and VEGF mRNA in tissues of local brain.Results After the hBMSCs were transplanted into the animal model,the quantities of the VEGF positive cells increased;real-time quantitative PCR showed that VEGF mRNA of local brain was enhanced.Conclusion The BMSCs transplantation can improve expression of endogenous VEGF and raise the content of VEGF in injured tissues of brain.

Effect of naloxone on neural functional recovery of rats with traumatic brain injury / 中国组织工程研究

BACKGROUND: As unspecific antagonist of opiate receptor, naloxone is widely used for multiple diseases which are related with abnormal release of endogenous opium. At present, researches suggest that large dosage of naloxone is used at early period can decrease death rate of patients with acute craniocerebral injury and promote neural functional recovery.OBJECTIVE: To investigate the effect of naloxone on improving the nervous function of rats with acute craniocerebral injury and to analyze effectively.DESIGN: Randomized grouping design based on the experimental animal.SETTING: Beijing Neurosurgical Institute.MATERIALS: Totally 250 SD rats were divided randomly into 0.3, 1.0,3.0, 9.0 mg/kg naloxone group, positive control group and negative control group.METHODS: Craniocerebral injured model was established with Feenly free fall struck, and the medicine was given 30 minutes after injury. The rats of the first four experimental group were injected transpeniponeally with naloxone hydrochloride by 0.3 mg/kg, 1.0 mg/kg, 3.0 mg/kg and 9.0 mg/kg respectively once a day; meanwhile, the control groups were given 2 mg citicoline sodium for injection and 0.5 mL normal saline per rat respectively. The longest time was 14 days.MAIN OUTCOME MEASURES: MNSS neural functional score was used every day. The brain edemas of 8 rats in each group were measured with wet-dry weight methods on the second and the fourth day after head trauma.RESULTS: Among 250 rats, 172 entered the final analysis. The nervous function of rats in naloxone groups was better than the two control groups (P ＜ 0.01), and that in 1, 3 and 9 mg/kg naloxone group were better than 0.3 mg/kg group (P ＜ 0.05), but there were no significant differences a mong the three naloxone groups (P ＞ 0.05). The brain edemas of rats in naloxone groups were lighter than that in the control groups (P ＜ 0.05), and that of 1, 3 and 9 mg/kg groups were lighter than 0.3 mg/kg (P ＜ 0.05), but there were no significant differences among these three groups (P ＞ 0.05).CONCLUSION: Naloxone can decrease the brain edemas of rats with traumatic brain injury, promote the nervous function recovery, and the treatment effect changes with the dosage during some range.Therefore, the experiment illustrates that naloxone can decrease the brain edemas of experimental brain injury in SD rats and improve the nervous function, but the effect of naloxone is associated with the dosages in some range.

Proliferation and migration in vivo of neural precursor cells in adult rat brain following fluid percussion injury / 中国组织工程研究

BACKGROUND: Neural precursor cells exist in the central nervous system (CNS) of adult mammals, characterized fundamentally by such biological properties of multipotential differentiation and capability of maintaining their stable quantity.OBJECTIVE: To investigate the proliferation and migration of the neural precursor cells in adult rat brain following fluid percussion injury (FPI),and explore their role in the repair of CNS damage.DESIGN:Randomized controlled experiment.SETITNG: Laboratory of Pathophysiology, Beijing Institute of Neurosurgery.MATERIALS: This experiment was carried out at the Laboratory of Pathophysiology, Beijing Institute of Neurosurgery. Totally 67 adult Wistar rats were randomized into a control group (n=7) and 5 FPI groups (n=12)sampled 1, 3, 7, 14, and 30 days after FPI, respectively. Each FPI group was further divided into artificial cerebral spinal fluid (CSF) group (n=2),basic fibroblast growth factor (bFGF) group (n=5) and neurotrophin-3 (NT3) group (n=5).METHODS: Lateral fluid percussion brain injury was induced in rats in the FPI group and the rats in the control group were only subjected to craniotomy without percussion. The rats in FPI groups were given intraperitoneal injection of bromodexyuridine (BrdU) at the dosage of 50 mg/kg for three times a day in 1- and 3-day FPI groups, but only once a day in 7-and 14-day groups, with the final dose given 2 hours before sacrifice. The rats in bFGF subgroup and NT-3 subgroup were given bFGF at the total daily dose of 360 ng and NT-3 of 240 ng, respectively, while those in artificial CSF subgroup received perfusion fluid of 4 μL without bFGF or NT3 every day. The dynamic expressions of nestin and BrdU in the rat brain were determined with immunocytochemistry. BrdU labeling method was used to identify the differentiated neural progenitor cells, and nestin expression was used to identify the neural progenitor cells.MAIN OUTCOME MEASURES: Expressions of Brdu, glial fibrillary acidic protein (GFAP)+/Brdu+ and GFAP-/Brdu+ cells in the rat brain of each group at various time points.with the control group, nestin-positive cells in the cortex, hippocampus and subventricular zone on the injured side was obviously increased at 1day after FPI (3.1±1.1 vs 0, 5.5±0.9 vs 1.3±0.8 and 8.1±0.9 vs 2.3±0.8 in each visual field, respectively, P＜0.05), reaching the peak on day 7 (7.5±1.2,10.2±1.5, and 13.6±1.2 in each visual field, respectively) and disappeared BrdU-positive cells in the cortex, hippocampus and subventricular zone on the injured side increased to the highest level 3 days after FPI (12.6±1.5,9.9±1.1, and 13.4±1.0 in each visual field, respectively), but gradually delar zone gradually migrated to the opposite side across the corpus callosum.CONCLUSION: FPI can stimulate the proliferation and migration of neural progenitor cells in adult rat brain, such as in the cortex, hippocampus and subventricular zone, where the nestin-positive cells is the most 7 days after the injury, but BrdU-positive cells is the most 3 days after the injury.

Effect of Schwann cells transplanting into injured middle brain on remyelination in rat / 中国康复理论与实践

@#Objective To investigate the remyelination after Schwann cells grafted into injured middle brain in rat.Methods Schwann cells originated from sciatic nerves of 1 to 2 day old rat were expanded and labeled by BrdU in vitro, transplanted into the rat middle brain injured by electric needle stimulus. Immunohistochemistry and myelin staining were used to locate in the BrdU positive cells and investigate remyelination.Results BrdU positive cells could be identified till at least 8 months after grafting, which mainly migrated toward injured ipsilateral cortex. New myelination could be seen in destructed brain stem area. Conclusion Schwann cells transplantation could promote CNS regeneration.

Transplantation of schwann’s cells transfected by brain derived neurotrophin factor gene into electrical reticular lesion of the brain stem in rats / 中华创伤杂志

Objective To investigate the effect of brain derived neurotrophin factor (BDNF) transfected with cationic liposome in protecting nerve tissue and promoting regeneration of the myelin sheath. Methods Wistar rat Schwanns cells (SWCs) were cultured in vitro. The recombinant cationic liposomes mediated PCDNA 3 BDNF was transplanted into SWCs and then into electrical reticular lesion of the brain stem (Group Ⅰ). At the same time, pure cell transplantation group (Group Ⅱ), empty transfected vector cell transplantation (Group Ⅲ) and normal saline injection group (Group Ⅳ) were set. The concentration of BDNF in the brain stem was measured by ELISA, the survival of myelinated basic protein (MBP) and SWCs in the brain stem by immunohistochemistry and the regeneration of the myelin sheath by the transmission electron microscope (TEM). Results One week after transplantation, the concentration of BDNF in the brain stem in the Group Ⅰ was much higher than that in other three groups ( P

Differentiation of rat embryonic neural stem cells promoted by co-cultured Schwann cells / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the factors which induce differentiation of embryonic neural stem cells.</p><p><b>METHODS</b>Rat embryonic neural stem cells were co-cultured with newborn rat Schwann cells in serum-free medium. The phenotype and specific-markers including tubulin-beta, glial fibrillary acidic protein (GFAP) and galactorcerebroside (GalC), were demonstrated by phase contrast microscopy and double immunofluorescence staining.</p><p><b>RESULTS</b>Overall, 80% +/- 5% of neural stem cells protruded several elongated processes and expressed tubulin-beta antigen at high levels, while 20 +/- 3% of them protruded several short processes and were GalC or GFAP positive.</p><p><b>CONCLUSION</b>The factors secreted by Schwann cells could induce rat embryonic neural stem cell to differentiate.</p>

Establishment of multidrug-resistance cell line C(6)/adr and reversal of drug-resistance / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the mechanism of multidrug resistance (MDR) in a human glioma cell and methods for overcoming multi-drug resistance.</p><p><b>METHODS</b>MDR cell line C(6)/adr was established. The expression of the mdr-1 gene and its P-glycoprotein (P-gp) in the C(6)/adr cell line was observed by RT-PCR and flow cytometry. The reversal of MDR by verapamil, erythromycin, dihydropyridine, P-gp monoclonal antibody and Salvia miltiorrhiza (SM) was studied by microtiter tetrazolium (MTT) assay or by high performance liquid chromatographic assay.</p><p><b>RESULTS</b>The mdr-1 gene of the C(6)/adr cell line was positive, over-expressing P-gp. The drug-resistance of the C(6)/adr cell lines could be partly reversed by 2 - 6 microg/ml of verapamil, 50 - 100 microg/ml of erythromycin, or 5 microg/ml of dihydropyridine. As concentration increased, they had a better effect. Among these drugs, 100 microg/ml of erythromycin had the best result of reversal. Dihydropyridine 1 microg/ml, P-gp monoclonal antibody and SM had no effect.</p><p><b>CONCLUSION</b>The mdr-1 gene and its expression might be associated with the MDR of glioma cells. Verapamil, erythromycin and dihydropyridine could reverse the MDR of glioma cells.</p>

Nestin expression and proliferation of ependymal cells in adult rat spinal cord after injury / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To determine cell proliferation and nestin expression in the ependyma of adult rat spinal cord after injury.</p><p><b>METHODS</b>Rat spinal cord injury models were established by aneurysm clip compression, and nestin expression and proliferation of ependymal cells at different times were shown with pathological and immuno-histochemical staining.</p><p><b>RESULTS</b>Ependymal cells adjacent to the injured site demonstrated a dramatic increase in nestin expression 24 hours after compression. Proliferating cell nuclear antigen was positive, and significant proliferation was observed after 7 days. Nestin expression was down regulated as time went by.</p><p><b>CONCLUSION</b>Normally quiescent mature ependymal cells appear to revert to an embryonic state in response to spinal cord injury.</p>