Recycling of SLC38A1 to the plasma membrane by DSCR3 promotes acquired temozolomide resistance in glioblastoma

PURPOSE

Glioblastoma multiforme (GBM) is a primary brain tumor with devastating prognosis. Although the O⁶-methylguanine-DNA methyltransferase (MGMT) leads to inherent temozolomide (TMZ) resistance, approximately half of GBMs were sufficient to confer acquired TMZ resistance, which express low levels of MGMT. The purpose of this study was to investigate the underlying mechanisms of the acquired TMZ resistance in MGMT-deficient GBM.

METHODS

The function of Down syndrome critical region protein 3 (DSCR3) on MGMT-deficient GBM was investigated in vitro and in an orthotopic brain tumor model in mice. Purification of plasma membrane proteins by membrane-cytoplasmic separation and subsequent label free-based quantitative proteomics were used to identified potential protein partners for DSCR3. Immunofluorescence was performed to show the reverse transport of solute carrier family 38 member 1 (SLC38A1) mediated by DSCR3.

RESULTS

DSCR3 is upregulated in MGMT-deficient GBM cells during TMZ treatment. Both DSCR3 and SLC38A1 were highly expressed in recurrent GBM patients. Silencing DSCR3 or SLC38A1 expression can increase TMZ sensitivity in MGMT-deficient GBM cells. Combination of proteomics and in vitro experiments show that DSCR3 directly binds internalized SLC38A1 to mediate its sorting into recycling pathway, which maintains the abundance on plasma membrane and enhances uptake of glutamine in MGMT-deficient GBM cells.

CONCLUSIONS

DSCR3 is a crucial regulator of acquired TMZ resistance in MGMT-deficient GBM. The DSCR3-dependent recycling of SLC38A1 maintains its abundance on plasma membrane, leading to tumor progression and acquired TMZ resistance in MGMT-deficient GBM.

Incidence and Possible Predictors of Sodium Disturbance After Craniopharyngioma Resection Based on QST Classification

OBJECTIVE

Serum sodium abnormalities are one of the most common manifestations after radical craniopharyngioma (CP) excision. The aim of this study was to report the incidence and possible predictors of serum sodium disturbance and explore features of sodium destabilization manifestation among QST classification results after CP resection.

METHODS

A retrospective analysis was performed of clinical, biochemical, radiologic, and operative data for 134 successive patients who underwent primary CP removal between September 2016 and March 2018. Univariate and multivariate analyses were conducted to determine predictors.

RESULTS

Sixty patients (44.8%) experienced hyponatremia and 67 patients (50%) hypernatremia; the median time of onset was 6 days and the first day after surgery, respectively. The incidence, onset, severity, and type of sodium disturbance among different types of CP differed significantly based on statistical tests (P < 0.05). Sodium disturbance was more common and severe in patients with type T tumors (P < 0.05). Age, tumor type, and preoperative diabetes insipidus were independent prognostic factors for obvious disorders of serum sodium.

CONCLUSIONS

Hyponatremia/hypernatremia is common after primary CP resection. The site of tumor origin has a direct effect on the growth pattern of CP, which may serve as a useful index for anticipating sodium perturbation after surgery. The level of sodium in children and patients with type T tumors, preoperative diabetes insipidus should be monitored closely throughout hospitalization.

Establishing a papillary craniopharyngioma cell line by SV40LT-mediated immortalization

BACKGROUND

Craniopharyngioma represents a troublesome tumor of the intracranial sellar region. There are currently no available well-characterized craniopharyngioma cell lines. This lack of reliable, immortal cell lines is a major reason for the slow progress in fundamental research related to craniopharyngioma.

METHODS

We describe the development of an immortal papillary craniopharyngioma (PCP) cell line by transfecting primary PCP cells with the pLenti-simian virus 40 large T antigen(SV40LT).

RESULTS

Three clones have been cultured for more than 14 months so far, while non-transfected cells ceased proliferation within three months of isolation. The established immortal PCP cell lines were identified to have BRAF^V600E mutations, while no mutations in tumor suppressor genes were found in primary cells or immortal cells. Immortal cells had higher proliferation rates and formed tumors when implanted in the bran of nude mice. BRAF inhibition in immortal PCP cells altered cell morphology, inhibited cell proliferation and promoted apoptosis.

CONCLUSION

We successfully developed PCP cell lines by SV40LT-mediated immortalization. These cell lines represent a powerful tool for fundamental and therapeutical studies on craniopharyngioma.

Development of a novel score to predict probability of growth without growth hormone after resection of paediatric craniopharyngiomas: relative to tumour growth pattern

OBJECTIVE

Some patients with paediatric craniopharyngiomas (PCs) showed normal growth despite growth hormone deficiency, which is known as growth without GH (GWGH); however, its mechanism remains unclear. We aimed to develop a novel clinical score to predict the probability of GWGH in PCs.

METHODS

A total of 708 PC patients were prospectively enrolled from six hospitals, among which 431 patients were finally included. Data from four of the six hospitals (n = 325) were used to develop the innovative clinical score (ICS), which was further validated using the data from the other two hospitals (n = 106). To establish and validate the ICS, sequential logistic regression was used to analyse the clinical characteristics including tumour growth pattern and tumour size and so on. Furthermore, C-statistic was employed to calibrate the discriminatory ability of the established clinical score, while a calibration plot was adopted for further assessment.

RESULTS

The overall incidence of GWGH was 16.9% (73/431). The ICS ranged from 2 to 23, with an optimism-corrected C-statistic of 0.820, Furthermore, the optimism-corrected C-statistic of external validation was 0.835, indicating good discriminatory power and robustness of the clinical score. Additionally, no apparent overestimation or underestimation was observed in the calibration plots, which showed excellent calibration power of the clinical score.

CONCLUSIONS

Based on tumour growth patterns and PC patients' clinical characteristics, individualized surgical strategies were promising to achieve long-term effective management of PC patients. The ICS is valuable for the evaluation of probability of developing postoperative GWGH.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT00949156.

Feasibility of primary human cell cultures as a model for adamantinomatous craniopharyngioma research: Evidence from RNA-Seq analysis

Adamantinomatous craniopharyngioma (ACP) is a benign epithelial tumor of the sellar region. Whether primary human cell cultures can be used as a stable research model has yet to be determined. The characteristics of three cultured craniopharyngioma primary cell (CPC) lines were identified using immunofluorescence. The culture duration for each CPC line was 10, 20 and 30 days. Cell lines and paired parental tumor tissues were subsequently analyzed using transcriptome sequencing (RNA-Seq). Transcriptomic differences between ACP tissues and CPC lines were compared. CPCs maintained the original epithelial lineage markers, including pan-cytokeratin and epithelial cell adhesion molecule. However, the Pearson's correlation coefficient of transcriptomes between each pair of CPC lines and ACP tissues decreased from 0.657 (cultured for 10 days) to 0.61 (cultured for 20 days) and further to 0.547 (cultured for 30 days). The number of differentially expressed genes between ACP tissues and CPCs was increased from 1,247 (cultured for 10 days) to 1,643 (cultured for 20 days) and then to 1,949 (cultured for 30 days). The results of Gene Set Enrichment Analysis demonstrated that the diversity of gene sets increased with longer culture time. Significant differences in the majority of signature gene sets were not observed between ACP tissues and CPCs, with the exception of keratinization phenotype [normalized enrichment score (NES)=−2.02, false discovery rate (FDR)=0.0038] and epithelial cell phenotype (NES=−1.82, FDR=0.032). Cell proliferation (NES=1.78, FDR=0.028) and mitosis (NES=1.93, FDR=0.012) were enhanced in CPCs. Therefore, primary human cell cultures can be used as a suitable research platform for ACP, however further experiments are required.

Identification of tumor stem-like cells in admanatimomatous craniopharyngioma and determination of these cells' pathological significance

OBJECTIVE

Nuclear β-catenin, a hallmark of active canonical Wnt signaling, can be histologically detected in a subset of cells and cell clusters in up to 94% of adamantinomatous craniopharyngioma (ACP) samples. However, it is unclear whether nuclear β-catenin-containing cells within human ACPs possess the characteristics of tumor stem cells, and it is unknown what role these cells have in ACP.

METHODS

Primary ACP cells were cultured from 12 human ACP samples. Adamantinomatous CP stem cell-like cells (CSLCs) showing CD44 positivity were isolated from the cultured primary ACP cells by performing magnetic-activated cell sorting. The tumor sphere formation, cell cycle distribution, stemness marker expression, and multidifferentiation potential of the CD44- cells and the CSLCs were analyzed.

RESULTS

Compared with the CD44- cells, the cultured human CSLCs formed tumor spheres and expressed CD44 and CD133; moreover, these cells demonstrated nuclear translocation of β-catenin. In addition, the CSLCs demonstrated osteogenic and adipogenic differentiation capacities compared with the CD44- cells. The CSLCs also displayed the capacity for tumor initiation in human-mouse xenografts.

CONCLUSIONS

These results indicate that CSLCs play an important role in ACP development, calcification, and cystic degeneration.

Endoplasmic reticulum stress induces apoptosis of arginine vasopressin neurons in central diabetes insipidus via PI3K/Akt pathway

Aims

Central diabetes insipidus (CDI), a typical complication caused by pituitary stalk injury, often occurs after surgery, trauma, or tumor compression around hypothalamic structures such as the pituitary stalk and optic chiasma. CDI is linked to decreased arginine vasopressin (AVP) neurons in the hypothalamic supraoptic nucleus and paraventricular nucleus, along with a deficit in circulating AVP and oxytocin. However, little has been elucidated about the changes in AVP neurons in CDI. Hence, our study was designed to understand the role of several pathophysiologic changes such as endoplasmic reticulum (ER) stress and apoptosis of AVP neurons in CDI.

Methods

In a novel pituitary stalk electric lesion (PEL) model to mimic CDI, immunofluorescence and immunoblotting were used to understand the underlying regulatory mechanisms.

Results

We reported that in CDI condition, generated by PEL, ER stress induced apoptosis of AVP neurons via activation of the PI3K/Akt and ERK pathways. Furthermore, application of N‐acetylcysteine protected hypothalamic AVP neurons from ER stress‐induced apoptosis through blocking the PI3K/Akt and ERK pathways.

Conclusion

Our findings showed that AVP neurons underwent apoptosis induced by ER stress, and ER stress might play a vital role in CDI condition through the PI3K/Akt and ERK pathways.

miR-519a enhances chemosensitivity and promotes autophagy in glioblastoma by targeting STAT3/Bcl2 signaling pathway

Background

Chemoresistance to temozolomide (TMZ) is a major challenge in the treatment of glioblastoma (GBM). We previously found that miR-519a functions as a tumor suppressor in glioma by targeting the signal transducer and activator of transcription 3 (STAT3)-mediated autophagy oncogenic pathway. Here, we investigated the effects of miR-519a on TMZ chemosensitivity and autophagy in GBM cells. Furthermore, the underlying molecular mechanisms and signaling pathways were explored.

Methods

In the present study, two stable TMZ-resistant GBM cell lines were successfully generated by exposure of parental cells to a gradually increasing TMZ concentration. After transfecting U87-MG/TMZ and U87-MG cells with miR-519a mimic or inhibitor, a series of biochemical assays such as MTT, apoptosis, and colony formation were performed to determine the chemosensitive response to TMZ. The autophagy levels in GBM cells were detected by transmission electron microscopy, LC3B protein immunofluorescence, and Western blotting analysis. Stable knockdown and overexpression of miR-519a in GBM cells were established using lentivirus. A xenograft nude mouse model and in situ brain model were used to examine the in vivo effects of miR-519a. Tumor tissue samples were collected from 48 patients with GBM and were used to assess the relationship between miR-519a and STAT3 expression.

Results

TMZ treatment significantly upregulated miR-519a in U87-MG cells but not in U87-MG/TMZ cells. Moreover, the expression of miR-519a and baseline autophagy levels was lower in U87-MG/TMZ cells as compared to U87-MG cells. miR-519a dramatically enhanced TMZ-induced autophagy and apoptotic cell death in U87-MG/TMZ cells, while inhibition of miR-519a promoted TMZ resistance and reduced TMZ-induced autophagy in U87-MG cells. Furthermore, miR-519a induced autophagy through modification of STAT3 expression. The in vivo results showed that miR-519a can enhance apoptosis and sensitized GBM to TMZ treatment by promoting autophagy and targeting the STAT3/Bcl-2/Beclin-1 pathway. In human GBM tissues, we found an inverse correlation between miR-519a and STAT3 expression.

Conclusions

Our results suggested that miR-519a increased the sensitivity of GBM cells to TMZ therapy. The positive effects of miR-519a may be mediated through autophagy. In addition, miR-519a overexpression can induce autophagy by inhibiting STAT3/Bcl-2 pathway. Therefore, a combination of miR-519a and TMZ may represent an effective therapeutic strategy in GBM.

Electronic supplementary material

The online version of this article (10.1186/s13045-018-0618-0) contains supplementary material, which is available to authorized users.

TREM-1 expression in craniopharyngioma and Rathke's cleft cyst: its possible implication for controversial pathology

Whether a mixed type of craniopharyngioma (CP) exists and whether papillary craniopharyngioma (pCP) is on a histopathological continuum with Rathke's cleft cyst (RCC) remain controversial. Herein, we examined the expression and localization of β-catenin, BRAF p.V600E (V600E), and triggering receptor expressed on myeloid cells-1 (TREM-1) in 58 samples including 20 pCPs, 26 adamantinomatous craniopharyngiomas (aCP), and 12 RCCs. Five aCPs were diagnosed with mixed type CPs and the remaining 21 cases were pure aCPs. Four of the 12 RCCs presented with significant squamous epithelium (SE). V600E immunoreactivity was observed in all pCPs in the cytoplasm, but not in the nuclei. aCPs and RCCs, including mixed type CP, did not express V600E. Nuclear β-catenin translocation was detected exclusively in aCPs. TREM-1 was expressed in pCPs. Additionally, TREM-1 expression was detected in the SE of 5 “mixed type” CPs, while it was absent in pure aCPs. TREM-1 was expressed in 4 RCCs with SE, but not in the remaining 8 RCCs. TREM-1 mRNA levels were compared in cultured pCP and aCP cells. TREM-1 mRNA level was significantly (p < 0.001; up to 4.045 fold) higher in pCPs than in aCPs. Western blotting revealed a significantly (p < 0.001; up to 7.19 fold) lower level of TREM-1 expression in aCP cells compared to that in pCP cells. Our findings further supported that RCC and pCP may represent two ends of a morphological spectrum. A variant showing overlapping histological features of aCP and pCP should not be considered as a mixed type.

[Hypopituitarism mode in patients with craniopharyngioma in relation to tumor growth pattern]

Objective: To investigate the pituitary hormone changes of patients with craniopharyngioma of different growth patterns during perioperative period and follow up time. Methods: Retrospective studies were performed on 212 cases of primary craniopharyngioma patient who received total tumor excision surgery in our hospital from January 2001 to May 2012. The characteristics of pituitary hormone and associated clinical manifestation during preoperative, perioperative and postoperative periods were analyzed according to the QST surgical classification. Results: One hundred and seventy-seven (83.5%) of patients present preoperative hypopituitarism, 36 of them were panhypopituitarism. The hypopituitarism condition was exacerbated during the early stage of post-operation period. The abnormal rates of HPA and HPT during the follow up were 60.1% and 58.3% respectively and hormone replacement treatment was needed for these patients. Craniopharyngioma of different growth patterns showed diversities in the characteristics of hypopituitarism. Conclusion: QST surgical classification was closely associated with the pattern of hypopituitarism, it can help to optimize treatment and prognosis estimation, and could be important criterion for improving the clinical practice of neuroendocrine monitoring, treatment and health education of patients with craniopharyngioma.

[Effect of recombinant human growth hormone therapy on metabolic parameters in patients with craniopharyngioma]

Objective: To investigate the effects of recombinant human growth hormone (rhGH) on metabolic parameters in patients with craniopharyngioma surgeries. Methods: Totallys 30 patients with craniopharyngioma were included in this retrospective study. They were divided into growth hormone (GH) group and control group according to whether they received rhGH therapy or not. The following parameters, including body mass index (BMI), weight, waist circumstance, transaminase, fasting blood glucose, lipid profile and high-sensitivity C-reactive protein (hsCRP) were compared after rhGH therapy for 4-6 months. Results: In GH group, patients were 18-46 (30.0±8.8) years old. The duration after craniopharyngioma surgery was (12.9±5.4) years. Before rhGH therapy, they had got sufficient thyroid and glucocorticoid hormone replacement. After rhGH therapy, the body weight decreased from (92.3±20.1) to (87.6 ±14.6) kg (P=0.190), with a reduction of BMI from (30.1±5.9) to (28.2±3.7) kg/m(2) (P=0.120). The waist circumference decreased from (104.4±9.4) cm to (98.8±10.6) cm (P=0.002). Alanine aminotransferase (ALT) decreased from (52±34) to (28±19) U/L (P=0.029), with a reduction of aspartate transaminase (AST) from (46±21) to (33±18) U/L (P=0.035) and γ-glutamyl transpeptadase (GGT) from (59±42) to (29±15) U/L (P=0.02). hsCRP decreased from (5.3±4.9) to (2.3±2.8) mg/L (P=0.006) and triglyceride (TG) decreased from (1.8±0.7) to (1.5±0.6) mmol/L (P=0.028). Fasting blood glucose, low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and free fat acid (FFA) were not significantly changed(all P>0.05). In the control group, the above mentioned parameters did not changed significantly during 4-6 months of observational period(all P>0.05). Conclusion: rhGH therapy improves metabolic parameters in patients after craniopharyngioma surgery by decreasing body weight, waist circumstance and fat deposit in liver, as well as lowering TG and hsCRP levels.

The purine receptor P2X7R regulates the release of pro-inflammatory cytokines in human craniopharyngioma

Craniopharyngiomas (CPs) are usually benign, non-metastasizing embryonic malformations originating from the sellar area. They are, however, locally invasive and generate adherent interfaces with the surrounding brain parenchyma. Previous studies have shown the tumor microenvironment is characterized by a local abundance of adenosine triphosphate (ATP), infiltration of leukocytes and elevated levels of pro-inflammatory cytokines that are thought to be responsible, at least in part, for the local invasion. Here, we examine whether ATP, via the P2X7R, participates in the regulation of cytokine expression in CPs. The expression of P2X7R and pro-inflammatory cytokines were measured at the RNA and protein levels both in tumor samples and in primary cultured tumor cells. Furthermore, cytokine modulation was measured after manipulating P2X7R in cultured tumor cells by siRNA-mediated knockdown, as well as pharmacologically by using selective agonists and antagonists. The following results were observed. A number of cytokines, in particular IL-6, IL-8 and MCP-1, were elevated in patient plasma, tumor tissue and cultured tumor cells. P2X7R was expressed in tumor tissue as well as in cultured tumor cells. RNA expression as measured in 48 resected tumors was positively correlated with the RNA levels of IL-6, IL-8 and MCP-1 in tumors. Furthermore, knockdown of P2X7R in primary tumor cultures reduced, and stimulation of P2XR7 by a specific agonist enhanced the expression of these cytokines. This latter stimulation involved a Ca²⁺-dependent mechanism and could be counteracted by the addition of an antagonist. In conclusion, the results suggest that P2X7R may promote IL-6, IL-8 and MCP-1 production and secretion and contribute to the invasion and adhesion of CPs to the surrounding tissue.

Interleukin‑6 induces an epithelial‑mesenchymal transition phenotype in human adamantinomatous craniopharyngioma cells and promotes tumor cell migration

Total resection of adamantinomatous craniopharyngioma (ACP) is complex and often leads to postoperative recurrence. This is due to the tendency of the tumor to invade the surrounding brain tissue and the generation of a local inflammatory state between the tumor cells and parenchyma. While there is evidence to suggest that interleukin-6 (IL-6) induces craniopharyngioma (CP)-associated inflammation, particularly in ACP, the role of IL-6 in the progression of ACP remains unclear. The results of the present study demonstrated that CP inflammation was associated with pathological classification, extent of surgery, degree of calcification and postoperative hypothalamic status scale. Cytokine antibody arrays were conducted to measure the expression of IL-6 and other inflammatory factors in tumor tissues in response to various levels of inflammatory exposure. IL-6, IL-6 receptor (IL-6R) and glycoprotein 130 expression was detected by immunohistochemistry. In addition, an ELISA was performed to quantify the levels of soluble IL-6R (sIL-6R) in the cystic fluid and supernatants of ACP cells and tumor-associated fibroblasts. These measurements demonstrated that ACP cells produce IL-6 and its associated proteins. In addition, the results revealed that while the viability of ACP cells was not affected, the migration of ACP cells was promoted by IL-6 treatment in a concentration-dependent manner. Conversely, treatment with an IL-6-blocking monoclonal antibody significantly decreased the migration of ACP cells. In addition, IL-6 treatment increased the expression of vimentin and decreased the expression of E-cadherin in a dose-dependent manner. The findings of the present study demonstrate that IL-6 may promote migration in vitro via the classic- and trans-signaling pathways by inducing epithelial-mesenchymal transition in ACP cell cultures.

Does Early Postsurgical Temozolomide Plus Concomitant Radiochemotherapy Regimen Have Any Benefit in Newly-diagnosed Glioblastoma Patients? A Multi-center, Randomized, Parallel, Open-label, Phase II Clinical Trial

Background:

The radiochemotherapy regimen concomitantly employing temozolomide (TMZ) chemotherapy and radiotherapy (RT) 4 weeks after surgery, followed by 6 cycles of TMZ is a common treatment for glioblastoma (GBM). However, its median overall survival (OS) is only 14.6 months. This study was to explore the effectiveness and safety of early TMZ chemotherapy between surgery and chemoradiotherapy plus the standard concomitant radiochemotherapy regimen.

Methods:

A randomized, parallel group, open-label study of 99 newly diagnosed GBM patients was conducted at 10 independent Chinese neurosurgical departments from June 2008 to June 2012. Patients were treated with concomitant radiochemotherapy regimen plus early postsurgical temozolomide (early TMZ group) or standard concomitant radiochemotherapy regimen (control group). Overall response was assessed based on objective tumor assessments, administration of corticosteroid and neurological status test. Hematological, biochemical, laboratory, adverse event (AE), and neurological condition were measured for 24 months of follow-up. The primary efficacy endpoint of this study was overall survival (OS). The secondary endpoint was progression free survival (PFS).

Results:

The median OS time in the early TMZ group was 17.6 months, compared with 13.2 months in the control group (log-rank test P = 0.021). In addition, the OS rate in the early TMZ group was higher at 6, 12, and 18 months than in the control group, respectively (P < 0.05). The median PFS time was 8.7 months in the early TMZ group and 10.4 months in the control group (log-rank test P = 0.695). AEs occurred in 29 (55.8%) and 31(73.8%) patients respectively in early and control groups, including nausea (15.4% vs. 33.3%), vomiting (7.7% vs. 28.6%), fever (7.7% vs. 11.9%), and headache (3.8% vs. 23.8%). Only 30.8% and 33.3% were drug-related, respectively.

Conclusions:

Addition of TMZ chemotherapy in the early break of the standard concomitant radiochemotherapy regimen was well tolerated and significantly improved the OS of the GBM patients, compared with standard concomitant radiochemotherapy regimen. However, a larger randomized trial is warranted to verify these results.

[Efficacy and safety of Willis covered stent for treatment of blood blister-like aneurysm]

OBJECTIVE

To evaluate the safety and short-term efficacy of Willis covered stent for treatment of blood blister-like aneurysms (BBA).

METHODS

Eight patients with BBA were treated with Willis covered stent system during the period from December 2014 to February 2016. The guiding catheter was placed as high as possible to facilitate the delivery of the covered stent system.

RESULTS

s Nine covered stents were implanted in the aneurysms of 8 patients (8 aneurysms), and 8 stents were released successfully in the parent arteries. In 6 patients, angiography immediately after stent release showed complete disappearance of the aneurysm and the parent arteries remained patent. One patient experienced a minor endoleak after stent implantation, and another stent was implanted to eliminate the endoleak. Iatrogeniccarotid-cavernous fistula occurred in 1 patient due to tortuosity of the parent artery, for which superficial temporal artery-to-middle cerebral artery bypass combined with parent artery occlusion was performed instead; the patient recovered smoothly and the bypass remained patent at 6 months after the operation. No other periprocedural complications occurred in these patients. Follow-up study showed no new-onset neurological deficits in these 8 patients, who had mRS score of 0 in 6 patients and of 1 in 2 patients. Digital subtractive angiography at 6 months after the operation demonstrated no aneurysm in these patients, and only one patient showed mild stenosis in the parent artery.

CONCLUSION

Willis covered stents are effective for treatment of BBA with good safety and short-term outcomes.

Role of IL-8 gene polymorphisms in glioma development in a Chinese population

This case-control study aimed to investigate the role of -251 T>A (rs4073) and -781 C>T (rs2227306) polymorphisms in the interleukin-8 (IL-8) gene in the development of glioma in a Chinese population. One hundred and twenty-seven glioma patients and 284 healthy control subjects were recruited to this study between February 2013 and December 2014. The IL-8 -251 T>A (rs4073) and -781 C>T (rs2227306) polymorphisms were genotyped by polymerase chain reaction coupled with restriction fragment length polymorphism. The patients and control subjects were comparable by gender (X² = 1.24, P = 0.27), tobacco smoking status (X² = 0.80, P = 0.37), alcohol consumption status (X² = 0.97, P = 0.32), and family history of cancer (X² = 1.54, P = 0.22). The age of glioma patients was statistically lower than that of control subjects (t = 2.87, P = 0.002). The chi-square test revealed the lack of any statistically significant differences in the genotype distributions of IL-8 rs4073 (X² = 0.89, P = 0.64) and rs2227306 (X² = 2.58, P = 0.28) between the glioma patients and control subjects. Unconditional logistic regression analysis revealed that the IL-8 rs4073 and rs2227306 gene polymorphisms did not contribute to the development of glioma. In conclusion, we determined that there is a lack of evidence suggesting a significant association between the IL-8 rs4073 and rs2227306 gene polymorphisms and the development of glioma in a Chinese population.

Epithelial-mesenchymal transition and clinicopathological correlation in craniopharyngioma

AIMS

To assess the immunophenotypic changes associated with epithelial-mesenchymal transition (EMT) in craniopharyngioma, especially at the tumour invasive front, and to correlate the findings with clinicopathological features and patient outcomes.

METHODS AND RESULTS

Forty-two craniopharyngiomas were investigated for the presence of EMT markers (vimentin, E-cadherin and β-catenin) by immunohistochemistry and western blot. The relationships between expression of these markers and various clinicopathological indicators and clinical outcomes of the tumours were analysed. There were statistically significant differences in the expression of vimentin and E-cadherin-β-catenin between adamantinomatous and papillary variants. The expression of vimentin and E-cadherin (but not that of β-catenin) in whole tumour sections was associated with tumour recurrence, and with postoperative weight and hypothalamic disturbances; the expression of vimentin and E-cadherin-β-catenin at the tumour invasive front was also associated with tumour recurrence, postoperative weight, and hypothalamic disturbances. The results from western blotting closely matched those of immunohistochemistry.

CONCLUSION

Our study demonstrates, for the first time, the potential prognostic implications of vimentin, E-cadherin and β-catenin expression in craniopharyngiomas. EMT may represent a crucial mechanism in the progression of craniopharyngiomas.

Bifocal germinomas in the pineal region and hypothalamo-neurohypophyseal axis: Primary or metastasis?

Whether bifocal germinomas (BFGs) synchronously presenting within the pineal region and the hypothalamo-neurohypophyseal axis (HNA) are primary germinomas of dual-origin remains to be elucidated. We analyzed MRI images and clinical features of 95 neurohypophyseal germinomas and 21 BFG patients and developed a tentative definition of the BFGs. We found dual-primary BFGs (true BFGs) do exist. The fundamental difference between primary and metastatic HNA germinomas was the direction of tumor growth. For a true BFG, the primary HNA tumor grew from the neurohypophysis toward the hypothalamus and almost invaded the whole pituitary stalk. For a false BFG (primary pineal germinoma with HNA metastasis), the metastatic HNA tumor first appeared at the third ventricular floor (TVF), grew toward the neurohypophysis, but commonly did not invade the inferior pituitary stalk. Compared to false BFGs, true BFGs commonly had diabetes insipidus as the first symptom, dysfunction of the anterior pituitary, no high-intensity MRI signal at the posterior pituitary, a larger extension of the HNA tumor, and fewer numbers of remote lesions from cerebrospinal fluid seeding. Accordingly, 12.8% (12/96) of our germinoma patients had true BFGs, and of these, 58.3% (7/12) were free of remote metastases and warranted treatment with limited radiotherapy. True BFGs with remote metastases and all false BFGs should be treated with craniospinal irradiation. We provided evidence for the diagnosis of true BFGs that is useful for radiotherapy strategy, suggesting that the existence of metastasis to other locations is not a diagnostic criterion for a true BFG.

Akt and β-catenin contribute to TMZ resistance and EMT of MGMT negative malignant glioma cell line

Glioblastoma is one of the most lethal cancers in central nervous system, and some individual cells that cannot be isolated for surgical resection and also show treatment-resistance induce poor prognosis. Hence, in order to research these cells, we treated temozolomide (TMZ)-sensitive U87MG cells with 400μM TMZ in culture media for over 6months and established TMZ-resistant cell line designated as U87/TR. We detected the MGMT status through pyrosequencing and western blotting, and we also assessed the proliferation, migration, EMT-like changes and possible activated signaling pathways in U87/TR cells. Our results demonstrated that U87/TR was MGMT negative, which indicated that MGMT made no contribution for TMZ-resistance of U87/TR. And U87/TR cells displayed cell cycle arrest, higher capacity for migration and EMT-like changes including both phenotype and characteristic proteins. We also revealed that both β-catenin and the phosphorylation level of Akt and PRAS40 were increased in U87/TR, while we did not observe the phosphorylation of mTOR in U87/TR. It indicated that activation of Akt and Wnt/β-catenin pathways may be response for the chemo-resistance and increased invasion of U87/TR cells, and the phosphorylation of PRAS40 and inactivated mTOR may be related to cell cycle arrest in U87/TR cells.

[RNA interference of PC4 and SFRS1 interacting protein 1 inhibits invasion and migration of U87 glioma cells]

OBJECTIVE

To investigate the effect of small interfering RNA (siRNA)-mediated silencing of PC4 and SFRS1 interacting protein 1 (PSIP1) on invasion and migration of human glioma U87 cells.

METHODS

Chemically synthesized siRNA targeting PSIP1 gene was transfected into U87 cells via lipofectamine, and the gene silencing effect was determined using real-time PCR. The changes in the invasion and migration abilities of the transfected cells were assessed with Transwell assay and wound healing assay, respectively. Western blotting was used to analyze the expression of N-cadherin, β-catenin and the transcription factor Slug.

RESULTS

The mRNA and protein level of PSIP1 was significantly reduced in U87 cells after transfection with PSIP1 siRNA (P<0.0001). PSIP1 knockdown in U87 cells resulted in significant suppression of cell invasion and migration abilities (P<0.01) and also reduced N-cadherin, β-catenin and Slug expressions.

CONCLUSION

s Silencing of PSIP1 impairs the invasion and migration abilities of glioma cells and lowers the expressions of N-cadherin, β-catenin and Slug, suggesting that PSIP1 may regulate Slug by classical Wnt/β-catenin signaling pathway to modulate epithelial-mesenchymal transition and promote the invasion and migration of glioma cells.

ERCC2 rs13181 polymorphism association with glioma susceptibility in a Chinese population

We conducted a case-control study to investigate the role of ERCC2 rs13181 polymorphism in glioma development. A total of 165 patients who were histopathologically diagnosed to have gliomas and 330 controls were collected at Jiujiang First People's Hospital between July 2012 and June 2014. The ERCC2 rs13181 polymorphism was analyzed using a polymerase chain reaction -restriction fragment length polymorphism assay. By conditional regression analysis, we found that the GG genotype of the ERCC2 rs13181 polymorphism is associated with susceptibility to gliomas when compared to the TT genotype (OR = 2.05, 95%CI = 1.11-3.79). In the recessive model, the GG genotype is associated with an increased risk of gliomas when compared with the TT+TG genotype (OR = 1.87, 95%CI = 1.03-3.37). In conclusion, the ERCC2 rs13181 polymorphism is correlated with an increased risk of gliomas in codominant and recessive models, which suggests that this polymorphism could influence the etiology of gliomas.

[Onyx embolization for treatment of dural arteriovenous fistula: comparison of long- distance versus routine injection method]

OBJECTIVE

To compare the efficacy, clinical characteristics, safety, injection time and radiation exposure of Onyx embolization using a long-distance injection method and routine injection method for management of dural arteriovenous fistula (DAVF).

METHODS

The clinical data were retrospectively analyzed in 59 patients with DAVF treated with Onyx embolization using long-distance injection method (28 patients) and routine injection method (31 patients). The efficacy, safety, injection time and radiation exposure during Onyx embolization were compared between the two injections methods.

RESULTS

The average radiation dose exposure to the surgeon per procedure was significantly lower in the long-distance injection group than in the routine group. The injection time (P=0.53), injection volume (P=0.78), number of supply arteries (P=0.80), Cognard types (P=0.67), and effect of embolization (P=0.88) were all similar between the two groups.

CONCLUSION

Endovaseular treatment of intracranial DAVF with Onyx embolization using the long-distance injection method is feasible, safe and effective and can reduce the radiation exposure to the surgeon.

The Impact of MMP-2 and Its Specific Inhibitor TIMP-2 Expression on the WHO Grade and Prognosis of Gliomas in Chinese Population: a Meta-Analysis

So far, the prognostic value of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of matrix metalloproteinase 2 (TIMP-2) expressions in patients with gliomas has been widely reported, especially in China. But, the results were inconsistent. Thus, we conducted a meta-analysis to determine the correlation of MMP-2 and TIMP-2 expressions with the prognosis of patients with gliomas. Identical search strategies were used to search relevant literature in electronic databases updated to May 1, 2015, and odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were estimated. Funnel plots and Egger’s tests were conducted for the evaluation of publication bias, and heterogeneity and sensitivity were also analyzed. Finally, a total of 25 studies involving 1572 patients were included in the meta-analysis. Coincidentally, all these studies were conducted in Chinese population. It was found that MMP-2 expression was significantly associated with high-WHO grade gliomas (n = 24, OR = 6.54, CI = 4.98–8.60; I² = 0 %, P = 0.911) and poor overall survival (OS), while it did not correlate to age (n = 2, OR = 0.78, CI = 0.35–1.74; I² = 0 %, P = 0.621) and gender (n = 2, OR = 1.15, CI = 0.51–2.62; I² = 0 %, P = 0.995). Moreover, the results of the pooled analysis indicated that there was no association between TIMP-2 expression and the WHO grade of gliomas (n = 7, OR = 1.02, 95 % CI = 0.68–1.54; I² = 71.4 %, P = 0.002), but the ratio of MMP-2 and TIMP-2 (MMP-2/TIMP-2) rose with the increase of the WHO grade of gliomas. In conclusion, there was no correlation between TIMP-2 expression and the WHO grade of gliomas, while MMP-2 expression was potently associated with high-WHO grade of gliomas.

A membranous structure separating the adenohypophysis and neurohypophysis: an anatomical study and its clinical application for craniopharyngioma

OBJECT This study aimed to identify the membranous septation between the adeno- and neurohypophysis. The clinical impact of this septation in the surgical removal of infradiaphragmatic craniopharyngioma (Id-CP) is also clarified. METHODS The sellar regions from 8 fetal and 6 adult cadavers were dissected. After staining first with H & E and then with picro-Sirius red, the membranous structures were observed and measured under normal light and polarization microscopy. The pre- and postsurgical images and intraoperative procedures in 28 cases of childhood Id-CP were reviewed and analyzed. RESULTS There is a significant membranous septation (termed the adenoneurohypophysis septation [ANHS]) lying behind the intermediate lobe to separate the adeno- and neurohypophysis. The average thicknesses are 21.9 ± 16.9 μm and 79.1 ± 43.2 μm in fetal and adult heads, respectively. The median segment of the septation is significantly thicker than the upper and lower segments. The ANHS extends from the suprasellar pars tuberalis to the sellar floor, where it is fused with the pituitary capsule. During Id-CP surgery performed via a transcranial approach, the ANHS can be identified to reserve the neurohypophysis. Moreover, by understanding the anatomy of this membrane, the pituitary stalk was preserved in 3 patients (10.7%). CONCLUSIONS There is a significant membrane separating the anterior and posterior lobes of the pituitary gland, which lies behind the intermediate lobe. Understanding the anatomy of this septation is important for identifying and preserving the neurohypophysis and pituitary stalk during Id-CP surgery.

[Diagnosis and treatment of multiple intracranial aneurysms]

OBJECTIVE

To explore the diagnosis and treatment strategy of multiple intracranial aneurysms (MIA).

METHODS

We retrospectively analyzed 96 patients with MIA (234 aneurysms). The rupture site was determined on the basis of computed tomographic and angiographic findings, and the supposed ruptured aneurysm was treated with coiling OR clipping. All the patients' records were reviewed including all computed tomographic scans and angiograms.

RESULTS

Twelve patients received conservative treatment, 56 patients were treated by endovascular embolization, and 28 patients received clipping; 44 patients received one-stage treatment, and 4 patients needed a second therapy. In 36 patients, only the ruptured aneurysm was eliminated. The clinical outcomes of these 84 patients evaluated by Glasgow Outcome Scale grades were: absence of deficits in 62 patients, minor deficits in 12 patients, major deficit in 8 patients; death occurred in 2 cases. Thirty patients were available for a 6-month follow-up with DSA, which revealed stable occlusion of the aneurysms in 29 patients and the need of a retreatment due to recanalization in only one patient.

CONCLUSION

Correct localization of the rupture aneurysm based on a comprehensive diagnosis is key to MIA treatment. All the aneurysms should be treated in one session whenever possible to protect the patient from rebleeding.

Interference of Notch 2 inhibits the progression of gliomas and induces cell apoptosis by induction of the cell cycle at the G0/G1 phase

Glioblastoma is the most common type of malignant brain tumor with a poor prognosis. The Notch signaling pathway is often aberrantly activated in glioma cells. In order to determine the expression of Notch 2 and to evaluate its possible prognostic value in malignant glioblastoma, specimens from 32 patients and 20 controls were analyzed using immunohistochemical staining and reverse transcription quantitative polymerase chain reaction. The expression of Notch 2 in the glioma tissues was significantly higher compared with that in the normal brain tissues (P<0.01). Subsequently, endogenous Notch 2 interference was effectively performed by specific small hairpin (sh)RNA in the glioma cancer cell line U251. The results from an MTT assay and from Annexin V-fluorescein isothiocyanate/propidium iodide staining indicated that interference of Notch 2 significantly inhibited the proliferation and induced the apoptosis of U251 cells. In addition, the cell cycle was analyzed using flow cytometry and the results revealed that Notch 2 shRNA induced cell cycle arrest at the G0/G1 phase in U251 cells. Additionally, proteins associated with the cell cycle and cell proliferation were detected using western blot analysis. The data demonstrated that the expression of P21, cyclin D and phosphorylated retinoblastoma was significantly inhibited in the Notch 2 shRNA-transfected U251 cells. The results of the present study provide further insights into the effects of Notch 2 and a molecular reference for brain tumor therapy.

Inhibition of EZH2 reverses chemotherapeutic drug TMZ chemosensitivity in glioblastoma

Glioblastoma remains among the most devastating cancers with a median survival of less than 15 months and virtually no survival beyond five years. Currently, the treatment of glioma includes surgery, radiation therapy, chemotherapy, and comprehensive treatment. Intrinsic or acquired resistance to TMZ, is one of the greatest obstacles in successful GB treatment, and is thought to be influenced by a variety of mechanisms. The EZH2 gene, which is expressed in various solid tumors, can regulate gene transcription and promote the generation and progression of tumors. Our aim was to investigate the relationship between EZH2 and multidrug-resistance of human glioblastoma cells. In this study, we established TMZ-resistant U251 and U87 clones (U251/TMZ and U87/TMZ cells), which expressed high level of EZH2. Using RNA interference, we demonstrated that the downregulation of Ezh2 expression in U251/TMZ and U87/TMZ cells resulted in apoptosis and a cell cycle arrest in the G1/S phase. Furthermore, the reduced expression of Ezh2 altered the MDR, MRP and BCRP mRNA and protein levels. These findings suggest that EZH2 plays an important part in the development of multidrug resistance and may represent a novel therapeutic target for multidrug-resistant glioblastoma.

IDH mutations occur frequently in Chinese glioma patients and predict longer survival but not response to concomitant chemoradiotherapy in anaplastic gliomas

Mutations in the isocitrate dehydrogenase 1 and 2 genes (IDH1 and IDH2) appear to occur frequently and selectively in gliomas. Our aim was to assess whether IDH mutations are common in Chinese glioma patients and whether the mutations predict good response to concomitant chemoradiotherapy. In this study IDH1 and IDH2 mutations were detected in a series of 203 gliomas. IDH1 mutations were present in 75 of the 203 cases (36.9%) while IDH2 mutations in 5 of the 203 cases (2.5%). No tumor was mutated in both IDH1 and IDH2. IDH1/2 mutations were associated with prolonged overall survival in the whole series of patients exclusive of pilocytic astrocytoma (P<0.001), WHO grade Ⅱ patients who received no adjuvant therapy after surgery (P=0.014) and WHO grade Ⅲ patients who received concomitant chemoradiotherapy (standard schedule) after surgery (P=0.033). Furthermore, there was no correlation between IDH1/2 mutations and reponse to concomitant chemoradiotherapy in anaplastic gliomas. Our results suggest that IDH1 mutations also occur freuqently in Chinese glioma patients but the frequency of IDH1 mutations is below the findings reported by North American and European groups. Furthermore, we confirm the prognostic significance of IDH1/2 mutations in gliomas, but the mutations cannot predict a favorable response to concomitant chemoradiotherapy in anaplastic gliomas.

Analysis of isocitrate dehydrogenase-1/2 gene mutations in gliomas

OBJECTIVE

To highlight recent researches which may show promise for histomolecular classification and new treatments for gliomas.

DATA SOURCES

All articles cited in this review were mainly searched from PubMed, which were published in English from 1996 to 2010.

STUDY SELECTION

Original articles and critical reviews selected were relevant to the isocitrate dehydrogenase-1/2 mutation in gliomas and other tumors.

RESULTS

Extraordinary high rates of somatic mutations in isocitrate dehydrogenase-1/2 occur in the majority of World Health Organization grade II and grade III gliomas as well as grade IV secondary glioblastomas. Isocitrate dehydrogenase-1/2 mutations are associated with younger age at diagnosis and a better prognosis in patients with mutated tumors. The functional role of isocitrate dehydrogenase-1/2 mutations in the pathogenesis of gliomas is still unclear.

CONCLUSION

Isocitrate dehydrogenase-1/2 mutations define a specific subtype of gliomas and may have great significance in the diagnosis, prognosis, and treatment of patients with these tumors.

The measurement of vesical detrusor electromyographic activity during nerve-sparing radical hysterectomy

OBJECTIVE

To evaluate the feasibility for confirming the preservation of the parasymphathetic nerve pathway innervating the bladder during nerve-sparing radical hysterectomy (RH).

METHODS

A total of 20 patients underwent nerve-sparing RH. Intraoperative electrical stimulation (IES) were performed on the root of pelvic splanchnic nerve (PSN) trunk while recording the electromyographic (EMG) activity of the vesical detrusor. The average duration achieving residual urine ≤50 mL and urodynamic study (UDS) was observed.

RESULTS

Evoked potentials were recorded when stimulating, in 18 patients who were referred IES-positive. Its duration was 9.89 days. The UDS results indicated that all voided normally. The remaining 2 IES-negative cases with no evoked potentials had longer duration and the micturitions were performed using abdominal pressure.

CONCLUSION

During nerve-sparing RH, IES based on the measurement of EMG activity is a useful tool for confirmation of the preservation of parasymphathetic nerve pathway innervating the bladder and prediction of the postoperative bladder function.

[Clinical study of pineal region tumors: experience with 132 patients]

OBJECTIVE

To review the clinical manifestations, imaging, tumor markers, treatment methods, pathology results and clinical curative effects of pineal region tumors and to evaluate the characteristics and intervention strategies for those tumors.

METHODS

The clinicopathological data of 132 patients with pineal region tumor treated in our department between January 2000 and May 2008 were retrospectively studied.

RESULTS

A moderate predominance in males was presented. The clinical manifestations of the disease included increased intracranial pressure and ocular movement impairment. There were some features but no regularity and specific appearance on imaging including CT and MRI. 88.6% of patients associated with hydrocephalus. A high serum level of alpha-fetoprotein (AFP) was presented in 14 cases and high HCG in 9 cases. Eighteen cases received direct radiation therapy and 7 had radiotherapy post biopsy. 107 cases were treated surgically and 63 cases received postoperative adjuvant treatment. 114 cases had pathology results including 56 germ cell tumors. The patients were followed up for 12 approximately 132 months. Recurrence developed in 23 cases and 12 cases died. The 5-year survival rate was 89.3%.

CONCLUSION

Pineal region tumors are often associated with hydrocephalus and this makes preoperative diagnosis difficult. Imaging examination may help diagnosis but less specific. Germ cell tumors may diagnosed by some tumor markers. Radiation therapy is the choice of treatment for pure germinomas. Other types of pineal region tumors should receive surgical treatment. Postoperative adjuvant treatment based on pathology can provide a good prognosis in pineal region tumor.

[Construction of delta-pIRES2-EGFP plasmid and its expression in HEK293 cells]

OBJECTIVE

To construct the delta-pIRES2-EGFP plasmid and investigate its expression in HEK293 cells.

METHODS

Full length cDNA of rat delta opioid receptor gene amplified from rat brain tissues using reverse transcription and nested PCR was cloned into pMD20 T vector. The delta cDNA was inserted into pIRES2-EGFP plasmid to construct the recombinant eukaryotic plasmid delta-pIRES2-EGFP, which was transfected into HEK293 cells via Lipofectamine2000. The expression of delta was examined under fluorescence microscope.

RESULTS

The recombinant delta-pIRES2-EGFP plasmid was successfully constructed, and high expression of delta was detected in HEK293 cells transfected by the plasmid.

CONCLUSION

delta-pIRES2-EGFP has been successfully cloned, which shows high expression of delta in HEK293 cells.

[Analysis of the factors contributing to diabetes insipidus after surgeries for craniopharyngiomas]

OBJECTIVE

To analyze the factors contributing to the occurrence of diabetes insipidus after operations for craniopharyngiomas.

METHODS

A total of 121 cases of diabetes insipidus following surgeries for craniopharyngiomas were retrospectively analyzed and the factors associated with postoperative diabetes insipidus were analyzed.

RESULTS

The incidence of diabetes insipidus was 27.3% (33/121 cases) before the operation, 89.9% (107/1119) early after the operation and 39.8%(37/93) in later stages after the operation. The occurrence of early postoperative diabetes insipidus showed a significant relation to the classification and calcification of the craniopharyngioma. Patients with supradiaphragmatic and extraventricular tumors had the lowest incidence of postoperative diabetes insipidus. Late postoperative diabetes insipidus was closely correlated to such factors as age, classification of craniopharyngioma, and intraoperative treatment of the pituitary stalk, but not to the scope of tumor resection or tumor calcification. Late diabetes insipidus was more frequent in children and patients with severed pituitary stalk. The incidence of late postoperative diabetes insipidus was significantly higher in patients with supradiaphragmatic and extra-intraventricular tumors than in those with tumors beneath the diaphragma sellae and extraventricular tumors.

CONCLUSIONS

Postoperative diabetes insipidus following surgeries for craniopharyngiomas is closely related to the tumor classification, calcification and pituitary stalk protection.

[Combined modality therapy for primary choriocarcinoma in the pineal region: report of two cases]

OBJECTIVE

We report two rare cases of primary choriocarcinoma in the pineal region verified histologically. In both cases, the pre-operative serum level of human chorionic gonadotropin (HCG) was significantly elevated to 128-/+935.7 and 9 -/+088.9 mIU/ml, respectively, and serum alpha-fetoprotein (AFP) was negative. The tumors were microsurgically removed, and postoperative hydrocephalus were treated by endoscopic third ventriculostomy. Both patients underwent chemotherapy and radiotherapy. After adjunctive treatment, the serum HCG decreased within normal range. During the two-year-long follow-up, no radiological (MRI) evidence was found to suggest recurrence in MR imaging, and the serum HCG was normal in one patient, but mildly elevated in the other. HCG measurement can be crucial to the diagnosis and post-treatment monitoring of choriocarcinoma, and radical surgical tumor removal and combined modality therapy including chemotherapy and radiotherapy may ensure good results.

[Establishment of rat hypophyseal compression model and changes in its postoperative biological characteristics]

OBJECTIVE

To establish a rat model of hypophyseal compression and observe and analyze the changes in its biological characteristics after operation.

METHODS

The rats were subjected to compression of the pituitary gland by stuffing the autologous muscular tissue into the hypophyseal fossa. The postoperative mortality of the rats was recorded and the volume of the hypophyeseal fossa, body weight, daily food intake, water intake, urine volume and urine specific gravity were measured.

RESULTS

Rat models of the hypophyseal compression model were successfully established by this procedure, which resulted in an increase of the volume of hypophyseal fossa by 35%. Rapid body weight loss occurred within 5 weeks after the operation (by as much as 31% on day 10). The rats exhibited recovery of appetite after 2 weeks, but their food intake was still less than that in the control group. Manifestations of central diabetes insipidus occurred gradually, which were especially obvious at 2 weeks and persisted afterwards, and at this time point, significant increment of urine volume (55.4-/+15.9 vs 18.5-/+5.8 ml) and lowered urine gravity (1.011-/+0.004 vs 1.036-/+0.006) were observed.

CONCLUSION

Rat models of hypophyseal compression can be established successfully by the described procedure, and the compression results in alteration of the rats' metabolic behaviors, which may differ from the effects of hypophysectomy and damage of pituitary stalk.

Association of epileptiform activity with neuronal death in the CA3 subfield of the hippocampus following focally evoked limbic seizures

OBJECTIVE: To investigate the relationnship between epileptiform activity and cell death in the CA3 subfield of hippocampus following focally evoked limbic seizures through a quantitative study. METHODS: Wistar rats used in this study received intra-amygdaloid injection of kainic acid to induce type epileptiform activity of different duration with continuous electroencephalographic (EEG) monitoring. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells. The number of CA3 neurons survived and TUNEL-positive cells were counted to estimate the number of necrotic cells. RESULTS: Epileptiform activity induced necrosis in the major form of apoptosis of the cells in CA3 subfield of the hippocampus following focally evoked limbic seizures. The longer the type epileptiform activity lasted, the less neurons survived, with consequent increase in the number of both necrotic and apoptotic cells. CONCLUSION: Prolongation of type IV seizures dose-dependently causes increase in apoptotic and necrotic cells in CA3 subfield of the hippocampus.

[Ultrastructural features of cultured rat cortical astrocytes with stretch-induced injury]

OBJECTIVE

To investigate the changes of ultrastructural features of cultured rat cortical astrocytes after stretch-induced injury.

METHODS

Rat cortical astrocytes isolated from 1- to 2-day-old rats were cultured till confluency, and then plated in tissue culture wells with flexible silastic bottom after purification. A computer-controlled device was used to produce stretch-induced injury in the astrocytes with the imposed pressure of 50, 150, and 250 kPa respectively, followed by observation of the ultrastructural changes in the astrocytes with light and electron microscopy.

RESULTS

Obvious ultrastructural destruction of the astrocytes occurred when the imposed stretch pressure was 50 kPa, and scanning electron microscopy demonstrated increased intercellular space and laceration of the cell body and its processes. Transmission electron microscopy revealed mitochondria swelling 1 h after stretch-induced injury and 6 h after the injury, vacuolar degeneration of the mitochondria occurred. Increased stretch pressure caused further decrease in the amount of glial filaments and densification of astrocytes.

CONCLUSIONS

Stress, even at a relatively small scale, can cause disruption of intercellular juncture and ultrastructural change of the cultured astrocyte, which may be related with extensive brain edema after traumatic brain injury.

Fibrous dysplasia of the skull complicated with meningioma: report of 2 cases

OBJECTIVE

Two cases of fibrous dysplasia of the skull complicated with meningioma that are seldom seen were reported.

Application of electromagnetic navigation in surgical treatment of intracranial tumors: analysis of 12 cases

OBJECTIVE

To explore the application and characteristics of electromagnetic navigation in neurosurgical operation.

METHODS

Neurosurgical operations with the assistance of electromagnetic navigation were performed in 12 patients with intracranial tumors.

RESULTS

Total removal of the tumor was achieved in 8 cases, subtotal removal in 3 and removal of the majority of the tumor in 1 case. The error in the navigation averaged 1.9+/-0.9 mm and the time consumed by preoperative preparation was 19+/-2 min with the exception in 1 case.

CONCLUSION

In comparison with optic navigation, electromagnetic navigation offers better convenience and absence of signal blockage, and with a head frame, automatic registration can be achieved.

Radiosurgical treatment of intractable epilepsy with low radiation dose

OBJECTIVE

To localize the epileptic foci with positron emission tomography (PET), and study the principles of target definition and method to determine the optimal range of exposure in radiosurgery for intractable epilepsy.

METHODS

This study included 176 patients with intractable epilepsy, who received linear accelerator radiosurgery after (18)F-FDG PET for epileptic foci localization. The patients were divided according to different peripheral doses used in the treatment into Group A in which radiation dose of 9 to 11 Gy was used, Group B with 11 to 13 Gy and Group C with exposure to over 13 Gy. Follow-up study was conducted in all the patients for a period ranging from 3 to 16 months, during which the frequency of seizure after treatment was recorded to evaluate the therapeutic effect.

RESULTS

The seizure frequency significantly decreased after radiosurgical treatment in all the groups, but between the groups, the decrement evinced no significant difference. According to Wieser's classification of the effect after operation, 46.9% cases belonged to grade I to II and 41.5% to grade III to IV. Obvious complications were not observed, nor did disability or mortality occurred in these cases.

CONCLUSIONS

Stereotactic radiosurgery with low radiation dose under the guidance of PET provides a safe, effective and minimally invasive surgical approach for patients with intractable epilepsy, and peripheral radiation doses of 9 to 11 Gy for the epileptic foci localized by PET is sufficient to ensure good clinical outcome.

Significance of radiological identification of the pituitary stalk in surgical removal of craniopharyngiomas

OBJECTIVE

To explore the radiological characteristics of craniopharyngiomas and particularly, to discuss the radiological manifestations of the pituitary stalk and their significance in safe resection of craniopharyngiomas.

METHODS

Retrospective analyses of the data obtained in preoperative radiological evaluation and intraoperative observation were conducted in 63 cases of craniopharyngiomas that were surgically removed.

RESULTS

In 6 cases (9.5%) the pituitary stalk was identified in preoperative radiological examination, and in 17 cases (27%) the position and course of pituitary stalk could be presumed according to the displacement of the third ventricle floor, which were confirmed in all cases during the operation. While in the other 33 (52.5%) cases, the pituitary stalk was only located during the operation. Massive calcification in the central position of the tumor stood in the way of achieving complete tumor removal, and the irregular peripheral enhancement in the superoposterior part of the tumor indicated tumor invasion of the hypothalamus.

CONCLUSION

Preoperative identification of the pituitary stalk and tumor calcification, together with a clear understanding of the position of the posterior part of the tumor in association with the hypothalamus is crucial to safe and complete surgical removal of craniopharyngiomas.

[Expression of proliferating cell nuclear antigen in craniopharyngioma and tumor recurrence]

OBJECTIVE

To investigate proliferating cell nuclear antigen labeling indices (PCNA-LI) in craniopharyngiomas in association with tumor recurrence.

METHODS

Immunohistochemistry was employed to examine the expression of PCNA in 43 craniopharyngioma samples of different pathological types, and the relationship between PCNA-LI and tumor recurrence was evaluated.

RESULTS

PCNA-LI was much higher in adamantinous tumors than in squamous papillary tumors that did not give rise to postoperative recurrence. Although PCNA-LI was higher in the recurrent lesions than in the primary tumor in adamantinoma group, the difference was not statistically significant.

CONCLUSIONS

Craniopharyngioma cells with different pathological features may possess varied proliferating potentials, and active proliferation is the main factor for postoperative recurrence of adamantinoma.

[Misdiagnosis of intracranial foreign body: report of one case]

This case of misdiagnosis of intracranial foreign body arose from undetailed history inquiry at hospitalization of the patient and poor image of wood foreign body by CT examination, suggesting that a detailed knowledge of the cause of injury and close examination of the wounds are crucial to avoid misdiagnosis.

[The study and manufacture of multifunctional brain microsurgery operation dilator]

The dilator consists of fixative clasp-handle, fixative platform, support arm, spatula and handle. The dilator may be fixed on the edge of bone window easily in the brain operation. The functions of the dilator include localization, dilation, expose, washing, lighting and suction. The spatula of the dilator may be prepared according to the different depth and width of the operation field.