DistSNE: Distributed computing and online visualization of DNA methylation-based central nervous system tumor classification.

The current state-of-the-art analysis of central nervous system (CNS) tumors through DNA methylation profiling relies on the tumor classifier developed by Capper and colleagues, which centrally harnesses DNA methylation data provided by users. Here, we present a distributed-computing-based approach for CNS tumor classification that achieves a comparable performance to centralized systems while safeguarding privacy. We utilize the t-distributed neighborhood embedding (t-SNE) model for dimensionality reduction and visualization of tumor classification results in two-dimensional graphs in a distributed approach across multiple sites (DistSNE). DistSNE provides an intuitive web interface (https://gin-tsne.med.uni-giessen.de) for user-friendly local data management and federated methylome-based tumor classification calculations for multiple collaborators in a DataSHIELD environment. The freely accessible web interface supports convenient data upload, result review, and summary report generation. Importantly, increasing sample size as achieved through distributed access to additional datasets allows DistSNE to improve cluster analysis and enhance predictive power. Collectively, DistSNE enables a simple and fast classification of CNS tumors using large-scale methylation data from distributed sources, while maintaining the privacy and allowing easy and flexible network expansion to other institutes. This approach holds great potential for advancing human brain tumor classification and fostering collaborative precision medicine in neuro-oncology.

Leveraging Attention-Based Convolutional Neural Networks for Meningioma Classification in Computational Histopathology.

Convolutional neural networks (CNNs) are becoming increasingly valuable tools for advanced computational histopathology, promoting precision medicine through exceptional visual decoding abilities. Meningiomas, the most prevalent primary intracranial tumors, necessitate accurate grading and classification for informed clinical decision-making. Recently, DNA methylation-based molecular classification of meningiomas has proven to be more effective in predicting tumor recurrence than traditional histopathological methods. However, DNA methylation profiling is expensive, labor-intensive, and not widely accessible. Consequently, a digital histology-based prediction of DNA methylation classes would be advantageous, complementing molecular classification. In this study, we developed and rigorously assessed an attention-based multiple-instance deep neural network for predicting meningioma methylation classes using tumor methylome data from 142 (+51) patients and corresponding hematoxylin-eosin-stained histological sections. Pairwise analysis of sample cohorts from three meningioma methylation classes demonstrated high accuracy in two combinations. The performance of our approach was validated using an independent set of 51 meningioma patient samples. Importantly, attention map visualization revealed that the algorithm primarily focuses on tumor regions deemed significant by neuropathologists, offering insights into the decision-making process of the CNN. Our findings highlight the capacity of CNNs to effectively harness phenotypic information from histological sections through computerized images for precision medicine. Notably, this study is the first demonstration of predicting clinically relevant DNA methylome information using computer vision applied to standard histopathology. The introduced AI framework holds great potential in supporting, augmenting, and expediting meningioma classification in the future.

Significantly higher expression of high-mobility group AT hook protein 2 (HMGA2) in the border zone of glioblastoma.

BACKGROUND: High-mobility group AT-hook protein 2 (HMGA2) is a gene regulatory protein that is correlated with metastatic potential and poor prognosis. It has been shown that HMGA2 is overexpressed in various tumors such as lung cancer or pancreatic cancer. The invasive character and highly aggressive structure of glioblastoma let us to investigate HMGA2 expression in the border zone of the tumor more closely. We compared HMGA2 expression between glioblastoma and normal brain tissue. In addition, we analyzed and compared HMGA2 expression in the border and center zones of tumors. Correlation tests between HMGA expression and clinical parameters such as MGMT-status and survival were performed. METHODS: Samples from 23 patients with WHO grade 4 glioblastomas were analyzed for HMGA2 expression using quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry (IHC) and correlated with clinical parameters. The areas from the tumor center and border were analyzed separately. Two normal brain tissue specimens were used as the controls. RESULTS: Our results confirm that HMGA2 is higher expressed in glioblastoma compared to healthy brain tissue (qPCR, P=0.013; IHC, P=0.04). Moreover, immunohistochemistry revealed significantly higher HMGA2 expression in the border zone of the tumor than in the tumor center zone (P=0.012). Survival analysis revealed a tendency for shorter survival when HMGA2 was highly expressed in the border zone. CONCLUSIONS: The results reveal an overexpression of HMGA2 in the border zone of glioblastomas; thus, the expression cluster of HMGA2 seems to be heterogenous and thorough borough surgical resection of the vital and aggressive border cells might be important to inhibit the invasive character of the tumor.

Fibrinogen to Albumin Ratio as Early Serum Biomarker for Prediction of Intra-Hospital Mortality in Neurosurgical Intensive Care Unit Patients with Spontaneous Intracerebral Hemorrhage.

Background: The prognostic value of the fibrinogen to albumin ratio on intrahospital mortality has been investigated in patients with cardiovascular disease, cancer, sepsis, and ischemic stroke; however, it has not been investigated for neurosurgical patients with spontaneous intracerebral hemorrhage (ICH). The present study investigates the impact of the fibrinogen to albumin ratio upon admission for intrahospital mortality in neurosurgical intensive care unit (ICU) patients with spontaneous ICH. Methods: A total of 198 patients with diagnosis of spontaneous ICH treated from 10/2008 to 12/2017 at our ICU were retrospectively analyzed. Blood samples were drawn upon admission, and the patients' demographic, medical data, and cranial imaging were collected. Binary logistic regression analysis was performed to identify independent prognostic factors for intrahospital mortality. Results: The total rate of intrahospital mortality was 35.4% (n = 70). In the multivariate regression analysis, higher fibrinogen to albumin ratio (OR = 1.16, CI = 1.02−1.31, p = 0.03) upon admission was an independent predictor of intrahospital mortality in neurosurgical ICU patients with ICH. Moreover, a fibrinogen to albumin ratio cut-off level of >0.075 was related to increased intrahospital mortality (Youden's index = 0.26, sensitivity = 0.51, specificity = 0.77). Conclusion: A fibrinogen to albumin ratio > 0.075 was significantly associated with increased intrahospital mortality in ICH patients.

Tumor treating fields therapy is feasible and safe in a 3-year-old patient with diffuse midline glioma H3K27M - a case report.

Since high grade gliomas are aggressive brain tumors, intensive search for new treatment options is ongoing. For adult patients with newly diagnosed (ndGBM) and recurrent glioblastoma (rGBM), low intensity intermediate frequency alternating electric fields, known as tumor treating fields (TTFields) have been established as a new treatment modality. Tumor treating fields significantly increase survival rates in combination with adjuvant temozolomide (TMZ) in adult and GBM patients. Here, we report about feasibility and safety of treatment on a pediatric patient with diffuse midline glioma who is receiving TTFields therapy in combination with temozolomide.

Oligosarcomas, IDH-mutant are distinct and aggressive.

Oligodendrogliomas are defined at the molecular level by the presence of an IDH mutation and codeletion of chromosomal arms 1p and 19q. In the past, case reports and small studies described gliomas with sarcomatous features arising from oligodendrogliomas, so called oligosarcomas. Here, we report a series of 24 IDH-mutant oligosarcomas from 23 patients forming a distinct methylation class. The tumors were recurrences from prior oligodendrogliomas or developed de novo. Precursor tumors of 12 oligosarcomas were histologically and molecularly indistinguishable from conventional oligodendrogliomas. Oligosarcoma tumor cells were embedded in a dense network of reticulin fibers, frequently showing p53 accumulation, positivity for SMA and CALD1, loss of OLIG2 and gain of H3K27 trimethylation (H3K27me3) as compared to primary lesions. In 5 oligosarcomas no 1p/19q codeletion was detectable, although it was present in the primary lesions. Copy number neutral LOH was determined as underlying mechanism. Oligosarcomas harbored an increased chromosomal copy number variation load with frequent CDKN2A/B deletions. Proteomic profiling demonstrated oligosarcomas to be highly distinct from conventional CNS WHO grade 3 oligodendrogliomas with consistent evidence for a smooth muscle differentiation. Expression of several tumor suppressors was reduced with NF1 being lost frequently. In contrast, oncogenic YAP1 was aberrantly overexpressed in oligosarcomas. Panel sequencing revealed mutations in NF1 and TP53 along with IDH1/2 and TERT promoter mutations. Survival of patients was significantly poorer for oligosarcomas as first recurrence than for grade 3 oligodendrogliomas as first recurrence. These results establish oligosarcomas as a distinct group of IDH-mutant gliomas differing from conventional oligodendrogliomas on the histologic, epigenetic, proteomic, molecular and clinical level. The diagnosis can be based on the combined presence of (a) sarcomatous histology, (b) IDH-mutation and (c) TERT promoter mutation and/or 1p/19q codeletion, or, in unresolved cases, on its characteristic DNA methylation profile.

Integrated Molecular-Morphologic Meningioma Classification: A Multicenter Retrospective Analysis, Retrospectively and Prospectively Validated.

PURPOSE: Meningiomas are the most frequent primary intracranial tumors. Patient outcome varies widely from benign to highly aggressive, ultimately fatal courses. Reliable identification of risk of progression for individual patients is of pivotal importance. However, only biomarkers for highly aggressive tumors are established (CDKN2A/B and TERT), whereas no molecularly based stratification exists for the broad spectrum of patients with low- and intermediate-risk meningioma. METHODS: DNA methylation data and copy-number information were generated for 3,031 meningiomas (2,868 patients), and mutation data for 858 samples. DNA methylation subgroups, copy-number variations (CNVs), mutations, and WHO grading were analyzed. Prediction power for outcome was assessed in a retrospective cohort of 514 patients, validated on a retrospective cohort of 184, and on a prospective cohort of 287 multicenter cases. RESULTS: Both CNV- and methylation family-based subgrouping independently resulted in increased prediction accuracy of risk of recurrence compared with the WHO classification (c-indexes WHO 2016, CNV, and methylation family 0.699, 0.706, and 0.721, respectively). Merging all risk stratification approaches into an integrated molecular-morphologic score resulted in further substantial increase in accuracy (c-index 0.744). This integrated score consistently provided superior accuracy in all three cohorts, significantly outperforming WHO grading (c-index difference P = .005). Besides the overall stratification advantage, the integrated score separates more precisely for risk of progression at the diagnostically challenging interface of WHO grade 1 and grade 2 tumors (hazard ratio 4.34 [2.48-7.57] and 3.34 [1.28-8.72] retrospective and prospective validation cohorts, respectively). CONCLUSION: Merging these layers of histologic and molecular data into an integrated, three-tiered score significantly improves the precision in meningioma stratification. Implementation into diagnostic routine informs clinical decision making for patients with meningioma on the basis of robust outcome prediction.

Proposed definition of competencies for surgical neuro-oncology training.

OBJECTIVE: The aim of this work is to define competencies and entrustable professional activities (EPAs) to be imparted within the framework of surgical neuro-oncological residency and fellowship training as well as the education of medical students. Improved and specific training in surgical neuro-oncology promotes neuro-oncological expertise, quality of surgical neuro-oncological treatment and may also contribute to further development of neuro-oncological techniques and treatment protocols. Specific curricula for a surgical neuro-oncologic education have not yet been established. METHODS: We used a consensus-building approach to propose skills, competencies and EPAs to be imparted within the framework of surgical neuro-oncological training. We developed competencies and EPAs suitable for training in surgical neuro-oncology. RESULT: In total, 70 competencies and 8 EPAs for training in surgical neuro-oncology were proposed. EPAs were defined for the management of the deteriorating patient, the management of patients with the diagnosis of a brain tumour, tumour-based resections, function-based surgical resections of brain tumours, the postoperative management of patients, the collaboration as a member of an interdisciplinary and/or -professional team and finally for the care of palliative and dying patients and their families. CONCLUSIONS AND RELEVANCE: The present work should subsequently initiate a discussion about the proposed competencies and EPAs and, together with the following discussion, contribute to the creation of new training concepts in surgical neuro-oncology.

Early Serum Biomarkers for Intensive Care Unit Treatment within the First 24 Hours in Patients with Intracerebral Hemorrhage.

BACKGROUND: The prognostic significance of serum biomarkers in patients with intracerebral hemorrhage (ICH) is not well investigated concerning inhospital mortality (IHM) and cardiopulmonary events within the first 24 hours of intensive care unit (ICU) treatment. The influence of troponin I (TNI) value and cortisol value (CV) on cardiopulmonary events within the first 24 hours of ICU treatment was reported in subarachnoid hemorrhage patients, but not in ICH patients up to now. The aim of this study was to investigate the role of early serum biomarkers on IHM and TNI value and CV on cardiopulmonary events within the first 24 hours of ICU treatment. PATIENTS AND METHODS: A total of 329 patients with spontaneous ICH were retrospectively analyzed. Blood samples were taken on admission to measure serum biomarkers. The TNI value and CV were defined as biomarkers for cardiopulmonary stress. Demographic data, cardiopulmonary parameters, including norepinephrine application rate (NAR) in microgram per kilogram per minute and inspiratory oxygen fraction (FiO2) within the first 24 hours, and treatment regime were analyzed concerning their impact on ICU treatment and in hospital outcome. Binary logistic analysis was used to identify independent prognostic factors for IHM. RESULTS: Patients with initially nonelevated CVs required higher NAR (p = 0.01) and FiO2 (p = 0.046) within the first 24 hours of ICU treatment. Lower cholinesterase level (p = 0.004), higher NAR (p = 0.002), advanced age (p < 0.0001), larger ICH volume (p < 0.0001), presence of intraventricular hemorrhage (p = 0.007) and hydrocephalus (p = 0.009), raised level of C-reactive protein (p = 0.024), serum lactate (p = 0.003), and blood glucose (p = 0.05) on admission were significantly associated with IHM. In a multivariate model, age (odds ratio [OR]: 1.055; 95% confidence interval [CI]: 1.026-1.085; p < 0.0001), ICH volume (OR: 1.016; CI: 1.008-1.025; p < 0.0001), and Glasgow Coma Scale (GCS) score (OR: 0.680; CI: 0.605-0.764; p < 0.0001) on admission as well as requiring NAR (OR: 1.171; CI: 1.026-1.337; p = 0.02) and FiO2 (OR: 0.951; CI: 0.921-0.983, p = 0.003) within the first 24 hours were independent predictors of IHM. CONCLUSION: Higher levels of C-reactive protein, serum lactate, blood glucose, and lower cholinesterase level on admission were significantly associated with IHM. Patients with initially nonelevated CVs required higher NAR and FiO2 within the first 24 hours of ICU treatment. Furthermore, requiring an NAR > 0.5 µg/kg/min or an FiO2 > 0.21 were identified as additional independent predictors for IHM. These results could be helpful to improve ICU treatment in ICH patients.

Case Report of Complete Radiological Response of a Thalamic Glioblastoma After Treatment With Proton Therapy Followed by Temozolomide and Tumor-Treating Fields.

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults. We present a case of a 42-year-old male patient presenting with headache and vomiting. Imaging demonstrated obstructive hydrocephalus and a ring-enhancing lesion in the right posterior thalamus. After endoscopic third ventriculostomy and stereotactic biopsy, the histopathologic diagnosis of a malignant glioma was confirmed by DNA methylation array as GBM isocitrate dehydrogenase wild type. The patient was treated with combined treatment of chemoradiation with temozolomide (TMZ) including proton boost, TMZ maintenance, and tumor-treating fields. In this case report, complete radiological response was observed 1 year after the end of radiation therapy.

Programmable valve breakage in shunt systems of children with posthemorrhagic hydrocephalus after minor head trauma-a case series.

PURPOSE: We report five rare cases of programmable valve breakage (Codman Hakim-Medos valve) in shunt systems of children with posthemorrhagic hydrocephalus. Only four similar studies have been published in the current literature. METHODS: Between 2013 and 2018, five children with posthemorrhagic hydrocephalus were admitted to the pediatric department. All patients had a history of slight blows to the head in a minor trauma and follow up MRI scans. After initial clinical examination, cranial computed tomography (CT) and X-ray were conducted. RESULTS: In all cases, pumping the reservoir resulted in very slow refilling. The cranial CT in one patient showed slit ventricles confirming the suspicion of overdrainage, the other cases a slight enhancement of the hydrocephalus. In lateral X-rays of the skull in comparison to the first X-ray control of the shunt valve, the pressure control chamber could be seen dislocated in the inferior part of the reservoir in all cases. Surgery revealed that the shunt valve was broken. The pressure control chamber had dropped to the bottom of the reservoir. After implantation of a new shunt valve, the symptoms resolved completely in all five children. Overall this complication occurred in 4.3% (5 of 85 implanted Codman Hakim-Medos valve) of all children necessitating ventriculoperitoneal shunt implantation between January 2013 and December 2018. CONCLUSION: The well-accepted Codman Hakim-Medos programmable valve is part of a tube-system, which is designed to offer the possibility of a reliable and precise treatment of hydrocephalus. Various mechanical and non-mechanical complications of shunt systems have been reported. Valve breakage is a very rare condition, often missed, and must be kept in mind when trauma and prior MRI scan are reported.

Carbon Ion Beam Reirradiation in Recurrent High-Grade Glioma.

BACKGROUND: Patients with recurrent glioma after prior radiotherapy have a poor prognosis. Carbon ion beam radiotherapy offers highly conformal dose distributions and more complex biological radiation effects eventually resulting in optimized normal tissue sparing and improved outcome. The aim of this study was to analyze toxicity, local control and overall survival after reirradiation of recurrent high-grade glioma with carbon ion radiotherapy. METHODS: Between 10/2015 and 12/2018, 30 patients (median age: 59 years) with recurrent high-grade glioma were reirradiated with carbon ion beams and retrospectively analyzed. Diagnosis of recurrent glioma was based on magnetic resonance imaging. Thirteen patients had repeated resection prior to reirradiation and 24 patients underwent additional chemotherapy. The median initial radiation dose was 60 Gy and the median time interval between the initial and repeated radiotherapy was 10 months. The reirradiation dose was 45 Gy (relative biological effectiveness) applied in 15 fractions. All patients received regular follow-up imaging after reirradiation. Kaplan-Meier estimation, log rank test and Cox regression analysis were used for statistical assessment. RESULTS: Applying common toxicity criteria, there were no grade 5 or 4 adverse events, while 8 patients showed grade 3 adverse events. The median follow-up after reirradiation was 11 months and the median overall survival after diagnosis of recurrent high-grade glioma was 13 months. The 6-, 12- and 24-month overall survival rates after diagnosis of recurrent high-grade glioma were 76%, 50% and 19%, respectively. Upon multivariate Cox regression analysis, a Ki67 score of the initial tumor histology of less than 20% was prognostic. Repeated resection or chemotherapy for the recurrent disease did not result in significantly prolonged survival. CONCLUSION: Carbon ion reirradiation in recurrent high-grade glioma is safe and feasible. No radiation-associated grade 4 toxicities were documented and treatment was tolerated well.

Placement of External Ventricular Drain: Comparison of Two Methods.

BACKGROUND: Insertion of a frontal external ventricular drain (EVD) is a common emergency procedure in neurosurgery. Malpositioning of the EVD and/or triggering a new intracerebral or intraventricular hemorrhage (nICVH) are typical complications. The standard procedure (SP) uses a tape measure to identify the Kocher's point for placement of a frontal burr hole. A faster alternative to determine the correct position is the freehand technique (FHT). This study compared both techniques with regard to the correct positioning of the EVD tip and the induction catheter-induced nICVH. METHODS: We performed a retrospective analysis of patients who required an EVD for acute or chronic hydrocephalus between January 2013 and March 2014. The study consisted of two groups. In the first group, EVDs were placed with the FHT. In the second group the SP was used. Postoperative computed tomography scans were analyzed regarding correct positioning of the ventricular catheter, malpositioning of the tip of the EVD using a 4-point-scale, and evidence for catheter-induced nICVH. RESULTS: A total of 95 patients could be included. The FHT was performed in 43 cases and the SP in 52 cases. No significant differences between the two groups were found regarding the correct position of the EVD tip (p = 0.38) and nICVH (p = 0.12). There was no significant difference in malpositioning of the EVD tip between the groups (p = 0.34). CONCLUSION: Our results show no significant differences between the two methods with regard to correct position, malpositioning, and nICVH. Thus we conclude that the FHT is a fast, safe, and effective alternative to the SP.

A Retrospective Analysis of 25 Cases With Peripheral Nerve Field Stimulation for Chronic Low Back Pain and the Predictive Value of Transcutaneous Electrical Nerve Stimulation for Patient Selection.

OBJECTIVE: Transcutaneous electrical nerve stimulation (TENS) and peripheral nerve field stimulation (PNFS) may be proposed to patients with chronic lumbar pain refractory to conventional treatment. Aim of this study was to assess the importance of preoperatively treatment with TENS as a predictive value for later successful PNFS and impact of PNFS in follow-up of 12 months. METHODS: Between 2012 and 2016, a retrospective analysis of 25 patients with chronic lumbar pain and implantation of a PNFS-system was performed. Pain intensity (NRS), health-related quality of life (EQ-5D-5L), Oswestry disability index (ODI), actual mood state scale (ASTS), and treatment satisfaction (CSQ-8) were assessed pre/postoperatively, after 6 and 12 months. TENS use before surgery was assessed. RESULTS: The cohort consisted of 25 patients with a median age of 56 years (IQR25-75 51-63). In a subgroup analysis, 18 patients used TENS before surgery, 7 did not use TENS and were excluded. No pain relief was observed in 14 patients. Ten of these patients showed later positive effect in PNFS trial stimulation. In four patients, pain relief with TENS was seen. One patient later on had no benefit after PNFS trial, three had sufficient pain relief. In the whole cohort, five patients had no benefit after PNFS trial, in 20 patients a neurostimulator was implanted. NRS, EQ-5D-5L, and ODI measures showed significant improvement in the whole follow-up after PNFS implantation. ASTS scale showed an increase of values for positive mood and a reduction in values for sorrow, fatigue, and anger. In 55%, a sustained reduction in demand for analgesics was seen after 6 months, 50% after 12 months, respectively. CONCLUSION: In this retrospective analysis, TENS has no predictive value in the selection of patients with low back pain for the PFNS treatment. PNFS is effective and safe to relieve significantly symptoms of chronic low back pain.

Microsurgical unilateral laminotomy for decompression of lumbar spinal stenosis: long-term results and predictive factors.

BACKGROUND: The microsurgical unilateral laminotomy (MUL) technique for bilateral decompression of lumbar spinal stenosis (LSS) is a less destabilizing alternative to laminectomy and leads to good short-term outcomes. However, little is known about the long-term results including predictive factors. METHODS: Medical records of patients who underwent MUL for LSS decompression between 2005 and 2010 were reviewed, and a questionnaire was distributed to complement the long-term outcome data. The study population consisted of 176 patients including 17 patients with stable grade I spondylolisthesis. Complications and reoperations were meticulously analyzed. Clinical outcome was measured using a modified Prolo scale and was further dichotomized in good vs. poor outcome. Predictive factors were obtained from uni- and multivariate analyses. RESULTS: The median age of the cohort was 70.0 years and the follow-up 71.7 months. Complications occurred in 5.1 % of the patients. The overall reoperation rate was 17.0 %, including surgery, which was exclusively performed at other levels in 4.0 %. The reoperation rate for fusion was 4.5 %. Good neurogenic claudication outcome faded from 98.3 % at hospital discharge to 47.2 % at 6 years. Multivariate analysis identified previous lumbar operation as a potential independent predictor of a reoperation; potential independent predictors of poor long-term claudication outcome were older age, female gender, higher body mass index (BMI) and tobacco smoking. CONCLUSIONS: In our experience, the long-term reoperation rate after MUL for LSS is not negligible and higher in previously operated patients. It seems like the good initial clinical results after MUL may fade over time, and several patient-related predictive factors including potentially modifiable obesity and tobacco smoking seem to play an important role.

NDRG2 and NDRG4 Expression Is Altered in Glioblastoma and Influences Survival in Patients with MGMT-methylated Tumors.

AIM: The N-myc down-regulated gene (NDRG) family is a group of genes that have predominantly tumor-suppressive effects. The goal of this study was to investigate the expression of NDRG2 and NDRG4 in surgical specimens of human glioblastoma and in normal brain tissue, and to search for correlations with overall (OS) and progression-free survival (PFS). MATERIALS AND METHODS: Samples from 44 patients (31 males, 13 females; mean age±SD=57.4±15.7 years) with primary (n=40) or recurrent glioblastoma (n=4) were analyzed by quantitative real-time polymerase chain reaction and immunohistochemistry, with dimensionless semiquantitative immunoreactivity score (IRS), ranging from 0-30] for expression of NDRG2 and NDRG4. Five non-tumorous autopsy brain specimens were used as controls. RESULTS: On the protein level, expression of NDRG2 was significantly down-regulated in glioblastoma (IRS=3.5±3.0 vs. 8.8±3.3; p=0.001), while expression of NDRG4 was significantly up-regulated (IRS=5.4±3.7 vs. 0.75±0.4 vs, p<0.001). There was no statistically significant difference in PFS between a group of 15 patients with glioblastoma with MGMT methylation and enhanced expression of NDRG4 mRNA who were treated with adjuvant radiochemotherapy (temozolomide and 60 Gy) and a group of patients with low expression of NDRG4 mRNA [10 (range=5.5-14.2) months vs. 21 (range=10.7-31.3) months] (p=0.13). CONCLUSION: Expression of both NDRG2 and NDRG4 genes is significantly altered in glioblastomas. PFS among the patients with glioblastoma with MGMT methylation treated with radiochemotherapy differed significantly in high-expression groups compared to patients without MGMT methlation and without radiochemotherapy (p<0.05).

High-mobility group AT-hook protein 2 expression and its prognostic significance in MGMT methylated and unmethylated glioblastoma.

High-mobility group AT-hook protein 2 (HMGA 2) is a transcription factor associated with malignancy and poor prognosis in a variety of human cancers. We correlated HMGA 2 expression with clinical parameters, survival, and O-6-methylguanine-DNA methyltransferase methylation status (MGMT) in glioblastoma patients. HMGA 2 expression was determined by performing quantitative real-time polymerase chain reaction (qPCR) and immunohistochemistry (IHC) in 44 glioblastoma patients and 5 non-tumorous brain specimens as controls. Gene expression levels of MGMT methylated vs. unmethylated patients, and gene expression levels between patient groups, both for qPCR and IHC data were compared using the Mann-Whitney U test. The relationship between HMGA 2 expression, progression-free survival and overall survival was analyzed using the Kaplan-Meier method and the log-rank test. P-values of <0.05 were considered statistically significant throughout the analyses. The mean age of patients at diagnosis was 57.4 ± 15.7 years, and the median survival was 16 months (SE 2.8; 95% CI, 10.6-21.4). HMGA 2 gene expression was significantly higher in glioblastoma compared to normal brain tissue on qPCR (mean, 0.35; SD, 0.27 vs. 0.03, SD, 0.05) and IHC levels (IRS mean, 17.21; SD, 7.43 vs. 3.20; SD, 1.68) (p=0.001). Survival analysis revealed that HMGA 2 overexpression was associated with a shorter progression-free and overall survival time in patients with methylation (n=24). The present study shows a tendency that HMGA 2 overexpression correlates with a poor prognosis of glioblastoma patients independent of MGMT methylation status. The results suggest that HMGA 2 could play an important role in the treatment of glioblastoma and could have a function in prognosis of this type of cancer.

Predicting the "usefulness" of 5-ALA-derived tumor fluorescence for fluorescence-guided resections in pediatric brain tumors: a European survey.

BACKGROUND: Five-aminolevulinic acid (Gliolan, medac, Wedel, Germany, 5-ALA) is approved for fluorescence-guided resections of adult malignant gliomas. Case reports indicate that 5-ALA can be used for children, yet no prospective study has been conducted as of yet. As a basis for a study, we conducted a survey among certified European Gliolan users to collect data on their experiences with children. METHODS: Information on patient characteristics, MRI characteristics of tumors, histology, fluorescence qualities, and outcomes were requested. Surgeons were further asked to indicate whether fluorescence was "useful", i.e., leading to changes in surgical strategy or identification of residual tumor. Recursive partitioning analysis (RPA) was used for defining cohorts with high or low likelihoods for useful fluorescence. RESULTS: Data on 78 patients <18 years of age were submitted by 20 centers. Fluorescence was found useful in 12 of 14 glioblastomas (85 %), four of five anaplastic astrocytomas (60 %), and eight of ten ependymomas grades II and III (80 %). Fluorescence was found inconsistently useful in PNETs (three of seven; 43 %), gangliogliomas (two of five; 40 %), medulloblastomas (two of eight, 25 %) and pilocytic astrocytomas (two of 13; 15 %). RPA of pre-operative factors showed tumors with supratentorial location, strong contrast enhancement and first operation to have a likelihood of useful fluorescence of 64.3 %, as opposed to infratentorial tumors with first surgery (23.1 %). CONCLUSIONS: Our survey demonstrates 5-ALA as being used in pediatric brain tumors. 5-ALA may be especially useful for contrast-enhancing supratentorial tumors. These data indicate controlled studies to be necessary and also provide a basis for planning such a study.

Relative positioning of classical benzodiazepines to the γ2-subunit of GABAA receptors.

GABAA receptors are the major inhibitory neurotransmitter receptors in the brain. Benzodiazepine exert their action via a high affinity-binding site at the α/γ subunit interface on some of these receptors. Diazepam has sedative, hypnotic, anxiolytic, muscle relaxant, and anticonvulsant effects. It acts by potentiating the current evoked by the agonist GABA. Understanding specific interaction of benzodiazepines in the binding pocket of different GABAA receptor isoforms might help to separate these divergent effects. As a first step, we characterized the interaction between diazepam and the major GABAA receptor isoform α1ß2γ2. We mutated several amino acid residues on the γ2-subunit assumed to be located near or in the benzodiazepine binding pocket individually to cysteine and studied the interaction with three ligands that are modified with a cysteine-reactive isothiocyanate group (-NCS). When the reactive NCS group is in apposition to the cysteine residue this leads to a covalent reaction. In this way, three amino acid residues, γ2Tyr58, γ2Asn60, and γ2Val190 were located relative to classical benzodiazepines in their binding pocket on GABAA receptors.