3D rotational fluoroscopy for intraoperative clip control in patients with intracranial aneurysms--assessment of feasibility and image quality.

BACKGROUND: Mobile 3D fluoroscopes have become increasingly available in neurosurgical operating rooms. In this series, the image quality and value of intraoperative 3D fluoroscopy with intravenous contrast agent for the evaluation of aneurysm occlusion and vessel patency after clip placement was assessed in patients who underwent surgery for intracranial aneurysms. MATERIALS AND METHODS: Twelve patients were included in this retrospective analysis. Prior to surgery, a 360° rotational fluoroscopy scan was performed without contrast agent followed by another scan with 50 ml of intravenous iodine contrast agent. The image files of both scans were transferred to an Apple PowerMac® workstation, subtracted and reconstructed using OsiriX® free software. The procedure was repeated after clip placement. Both image sets were compared for assessment of aneurysm occlusion and vessel patency. RESULTS: Image acquisition and contrast administration caused no adverse effects. Image quality was sufficient to follow the patency of the vessels distal to the clip. Metal artifacts reduce the assessability of the immediate vicinity of the clip. Precise image subtraction and post-processing can reduce metal artifacts and make the clip-site assessable and depict larger neck-remnants. CONCLUSION: This technique quickly supplies images at adequate quality to evaluate distal vessel patency after aneurysm clipping. Significant aneurysm remnants may be depicted as well. As it does not require visual control of all vessels that are supposed to be evaluated intraoperatively, this technique may be complementary to other intraoperative tools like indocyanine green videoangiography and micro-Doppler, especially for the assessment of larger aneurysms. At the momentary state of this technology, it cannot replace postoperative conventional angiography. However, 3D fluoroscopy and image post-processing are young technologies. Further technical developments are likely to result in improved image quality.

MB3W1 is an orthotopic xenograft model for anaplastic medulloblastoma displaying cancer stem cell- and Group 3-properties.

BACKGROUND: Medulloblastoma is the most common malignant brain tumor in children and can be divided in different molecular subgroups. Patients whose tumor is classified as a Group 3 tumor have a dismal prognosis. However only very few tumor models are available for this subgroup. METHODS: We established a robust orthotopic xenograft model with a cell line derived from the malignant pleural effusions of a child suffering from a Group 3 medulloblastoma. RESULTS: Besides classical characteristics of this tumor subgroup, the cells display cancer stem cell characteristics including neurosphere formation, multilineage differentiation, CD133/CD15 expression, high ALDH-activity and high tumorigenicity in immunocompromised mice with xenografts exactly recapitulating the original tumor architecture. CONCLUSIONS: This model using unmanipulated, human medulloblastoma cells will enable translational research, specifically focused on Group 3 medulloblastoma.

Detection of Cerebral Vasospasm Following Aneurysmal Subarachnoid Hemorrhage Using Motor Evoked Potentials.

BACKGROUND: Early detection of vasospasm (VS) following aneurysmal subarachnoid hemorrhage (aSAH) is vital to trigger therapy and to prevent infarction and subsequent permanent neurological deficit. Although motor evoked potentials (MEPs) are a well-established method for intraoperative detection of cerebral VS and cerebral ischemia during aneurysm surgery, there are no studies investigating the diagnostic value of MEPs for detecting delayed VS following aSAH in an intensive care unit. OBJECTIVE: A prospective study was conceived to assess the diagnostic accuracy of MEPs in comparison with digital subtraction angiography. METHODS: MEP threshold changes were determined in patients both with and without angiographic VS following high-grade aSAHs. Sensitivity, specificity, and the positive and negative predictive values of significant MEP threshold increases, which indicate angiographic VS, were calculated. RESULTS: In all patients experiencing VS of the arteries supplying cerebral motor areas, a minimal MEP threshold increase of 50 mA (mean 66.25 mA) was observed, whereas a maximum MEP threshold increase of 30 mA was observed in patients without VS. Therefore, an increase from a baseline of ≥50 mA was considered significant and resulted in a sensitivity of 0.83, a specificity of 0.92, a positive predictive value of 0.83, and a negative predictive value of 0.92. CONCLUSION: VS following aSAH can be detected accurately by using MEPs. MEPs are a feasible bedside tool for online VS detection in an intensive care unit and, therefore, may complement existing diagnostic tools.

Behavioral disorders and cognitive impairment associated with cerebellar lesions.

In the last decade evidence has accumulated that suggests that the cerebellum is involved not only in motor but also in behavioral and cognitive functions. A myriad of anatomical, clinical and imaging studies support that assumption. The lengthened survival of patients with cerebellar tumors has also brought an increased awareness of neurocognitive deficits to the neurooncological community. Although evidence from neurosurgical case series exists that clearly demonstrates that patients afflicted from posterior fossa tumors are at high risk for long-term cognitive or adaptive deficits, there is still a lack of systematic translational review on this issue. Accordingly a systematic review was conducted to summarize the impact of cerebellar lesions on behavior and cognition. The findings and clinical implications are discussed in the light of the recent advances in neuroimaging techniques.

Intraoperative cerebral angiography by intravenous contrast administration with 3-dimensional rotational fluoroscopy in patients with intracranial aneurysms: a feasibility study.

BACKGROUND: Intraoperative imaging of cerebral aneurysms may be desirable in emergency situations with large space-occupying hematomas or to visualize vessels after clip placement. Mobile 3-dimensional fluoroscopes are available in a number of neurosurgical departments and may be useful in combination with simple image postprocessing to depict cerebral vessels. OBJECTIVE: To assess whether intracranial aneurysms are detectable with appropriate image quality with intraoperative 3-dimensional fluoroscopy with intravenous contrast administration. METHODS: Eight patients were included in the study. The patients' heads were fixed in a radiolucent Mayfield clamp. First, a rotational fluoroscopy scan was performed without contrast agent. Then, a second scan with 50 mL iodine contrast agent was performed. The DICOM (digital imaging and communications in medicine) data of both scans were transferred to an Apple PowerMac workstation, subtracted, and reconstructed with OsiriX imaging software. The images were compared with preoperative angiograms. RESULTS: No adverse effects were observed during contrast administration. The entire procedure from fluoroscope positioning to the production of usable 3-dimensional images took 5 to 6 minutes with an image acquisition time of 2 × 24 seconds. The configuration of the aneurysm and the vessel anatomy were assessable. Previous coiling limited image quality in 1 patient. CONCLUSION: This technique quickly provides images of adequate quality to assess the configuration of intracranial aneurysms, which may be helpful when immediate intraoperative information about intracranial vessel pathologies is required. The positioning of the fluoroscope, image acquisition, and processing can be completely integrated into the surgical workflow.

Intraoperative somatosensory evoked potential recovery following opening of the fourth ventricle during posterior fossa decompression in Chiari malformation: case report.

The most appropriate surgical technique for posterior fossa decompression in Chiari malformation (CM) remains a matter of debate. Intraoperative electrophysiological studies during posterior fossa decompression of Type I CM (CM-I) aim to shed light on the entity's pathomechanism as well as on the ideal extent of decompression. The existing reports on this issue state that significant improvement in conduction occurs after craniotomy in all cases, but additional durotomy contributes a further improvement in only a minority of cases. This implies that craniotomy alone might suffice for clinical improvement without the need of duraplasty or even subarachnoid manipulation at the level of the craniocervical junction. In contrast to published data, the authors describe the case of a 32-year-old woman who underwent surgery for CM associated with extensive cervicothoracic syringomyelia and whose intraoperative somatosensory evoked potentials (SSEPs) did not notably improve after craniotomy or following durotomy; rather, they only improved after opening of the fourth ventricle and restoration of CSF flow through the foramen of Magendie. Postoperatively, the patient recovered completely from her preoperative neurological deficits. To the authors' knowledge, this is the first report of significant SSEP recovery after opening the fourth ventricle in the decompression of a CM-I. The electrophysiological and operative techniques are described in detail and the findings are discussed in the light of available literature. The authors conclude that there might be a subset of CM-I patients who require subarachnoid dissection at the level of the craniocervical junction to benefit clinically. Prospective studies with detailed electrophysiological analyses seem warranted to answer the question regarding the best surgical approach in CM-I decompression.

Intraoperative 3D rotational angiography: an emergency tool for the diagnosis of intracranial aneurysms.

It was the objective of this report to present a case of recurrent aneurysmal subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) in which an MCA aneurysm was detected by 3D rotational fluoroscopy in an emergency situation. A 44-year-old woman was admitted from an external department after repeated SAH and temporal ICH. Due to progressive anisocoria and cardiocirculatory instability, she was transferred to the operating room without angiography. After a 3D rotational fluoroscopy baseline scan, another scan with 50 ml of iodine contrast agent was performed. The Digital Imaging and Communications in Medicine (DICOM) data sets were subtracted and reconstructed using the OsiriX® free imaging software. No adverse effect was observed during and after the administration of the contrast agent. The entire procedure from positioning of the fluoroscope to the production of utilizable 3D images was completely integrated into the surgical workflow with an image acquisition time of 2 × 24 s. The configuration of the aneurysm, the aneurysm-carrying vessel, and the distal vessel anatomy were well assessable. This technique quickly supplies images at adequate quality to assess the configuration of an intracranial aneurysm and is a useful diagnostic tool if the patient's critical condition prohibits aneurysm diagnostics by angiography or CT angiography.

Long-term tumor control of spinal dissemination of cerebellar glioblastoma multiforme by combined adjuvant bevacizumab antibody therapy: a case report.

BACKGROUND: Glioblastoma multiforme located in the posterior fossa is extremely rare with a frequency up to 3.4%. Compared with glioblastoma of the hemispheres the prognosis of infratentorial glioblastoma seems to be slightly better. Absence of brainstem invasion and low expression rates of epidermal growth factor receptor are described as factors for long-time survival due to the higher radiosensitivity of these tumors. CASE PRESENTATION: In this case study, we report a German female patient with an exophytic glioblastoma multiforme arising from the cerebellar tonsil and a secondary spinal manifestation. Furthermore, the tumor showed no O (6)-Methylguanine-DNA methyltransferase promotor-hypermethylation and no isocitrate dehydrogenase 1 mutations. All these signs are accompanied by significantly shorter median overall survival. A long-term tumor control of the spinal metastases was achieved by a combined temozolomide/bevacizumab and irradiation therapy, as part of a standard care administered by the treating physician team. CONCLUSION: To our knowledge this is the first published case of a combined cerebellar exophytic glioblastoma with a subsequent solid spinal manifestation. Furthermore this case demonstrates a benefit undergoing this special adjuvant therapy regime in terms of overall survival. Due to the limited overall prognosis of the disease, spinal manifestations of glioma are rarely clinically relevant. The results of our instructive case, however, with a positive effect on both life quality and survival warrant treating future patients in the frame of a prospective clinical study.

Impact of MACC1 on human malignant glioma progression and patients' unfavorable prognosis.

BACKGROUND: Metastasis-associated in colon cancer 1 (MACC1) has been established as an independent prognostic indicator of metastasis formation and metastasis-free survival for patients with colon cancer and other solid tumors. However, no data are available concerning MACC1 expression in human astrocytic tumors. Glioblastoma multiforme (GBM) is the most prevalent primary brain tumor of adulthood, and due to its invasive and rapid growth, patients have unfavorable prognoses. Although these tumors rarely metastasize, their invasive and migratory behavior is similar to those of metastatic cells of tumors of different origin. Thus, we hypothesized that MACC1 may be involved in progression of human gliomas. METHODS: We performed real-time measurements of proliferation and migration in MACC1-transfected GBM cell lines (U138, U251) and evaluated tumor formation in organotypic hippocampal slice cultures of mice. Semiquantitative and quantitative real-time reverse transcription PCR analyses were performed for MACC1 and for its transcriptional target c-Met in human astrocytoma of World Health Organization grade II (low-grade astrocytoma) and GBM biopsies. Data were validated by MACC1 immunohistochemistry in independent matched samples of low-grade astrocytoma and GBM. RESULTS: MACC1 increases the proliferative, migratory, and tumor-formation abilities of GBM cells. The c-Met inhibitor crizotinib reduced MACC1-induced migration and tumor formation in organotypic hippocampal slice cultures of mice. Analyzing patients' biopsies, MACC1 expression increased concomitantly with increasing World Health Organization grade. Moreover, MACC1 expression levels allowed discrimination of dormant and recurrent low-grade astrocytomas and of primary and secondary GBM. Strong MACC1 expression correlated with reduced patient survival. CONCLUSIONS: MACC1 may represent a promising biomarker for prognostication and a new target for treatment of human gliomas.

Hypoxia induced CA9 inhibitory targeting by two different sulfonamide derivatives including acetazolamide in human glioblastoma.

HIF-1α regulated genes are mainly responsible for tumour resistance to radiation- and chemo-therapy. Among these genes, carbonic anhydrase isoform IX (CA9) is highly over expressed in many types of cancer especially in high grade brain cancer like Glioblastoma (GBM). Inhibition of the enzymatic activity by application of specific chemical CA9 inhibitor sulphonamides (CAI) like Acetazolamide (Aza.), the new sulfonamide derivative carbonic anhydrase inhibitor (SU.D2) or indirect inhibitors like the HIF-1α inhibitor Chetomin or molecular inhibitors like CA9-siRNA are leading to an inhibition of the functional role of CA9 during tumorigenesis. Human GBM cells were treated with in vitro hypoxia (1, 6, or 24 h at 0.1%, O2). Aza. application was at a range between 250 and 8000 nM and the HIF-1α inhibitor Chetomin at a concentration range of 150-500 nM. Cell culture plates were incubated for 24 h under hypoxia (0.1% O2). Further, CA9-siRNA constructs were transiently transfected into GBM cells exposed to extreme hypoxic aeration conditions. CA9 protein expression level was detectable in a cell-type specific manner under normoxic conditions. Whereas U87-MG exhibited a strong aerobic expression, U251 and U373 displayed moderate and GaMG very weak normoxic CA9 protein bands. Aza. as well as SU.D2 displayed inhibitory characteristics to hypoxia induced CA9 expression in the four GBM cell lines for 24 h of hypoxia (0.1% O2) at concentrations between 3500 and 8000 nM, on both the protein and mRNA level. Parallel experiments using CA9-siRNA confirmed these results. Application of 150-500 nM of the glycolysis inhibitor Chetomin under similar oxygenation conditions led to a sharply reduced expression of both CA IX protein and CA9 mRNA levels, indicating a clear glucose availability involvement for the hypoxic HIF-1α and CA9 expression in GBM cells. Hypoxia significantly influences the behaviour of human tumour cells by activation of genes involved in the adaptation to hypoxic stress. The main objective in malignant GBM therapy is either to eradicate the tumour or to convert it into a controlled, quiescent chronic disease. Aza., SU.D2, Chetomin or CA9-siRNA possesses functional CA9 inhibitory characteristics when applied against human cancers with hypoxic regions like GBM. They may be used as alternative or in conjunction with other direct inhibitors possessing similar functionality, thereby rendering them as potential optimal tools for the development of an optimized therapy in human brain cancer treatment.

Magnesium treatment for neuroprotection in ischemic diseases of the brain.

This article reviews experimental and clinical data on the use of magnesium as a neuroprotective agent in various conditions of cerebral ischemia. Whereas magnesium has shown neuroprotective properties in animal models of global and focal cerebral ischemia, this effect could not be reproduced in a large human stroke trial. These conflicting results may be explained by the timing of treatment. While treatment can be started before or early after ischemia in experimental studies, there is an inevitable delay of treatment in human stroke. Magnesium administration to women at risk for preterm birth has been investigated in several randomized controlled trials and was found to reduce the risk of neurological deficits for the premature infant. Postnatal administration of magnesium to babies after perinatal asphyxia has been studied in a number of controlled clinical trials. The results are promising but the trials have, so far, been underpowered. In aneurysmal subarachnoid hemorrhage (SAH), cerebral ischemia arises with the onset of delayed cerebral vasospasm several days after aneurysm rupture. Similar to perinatal asphyxia in impending preterm delivery, treatment can be started prior to ischemia. The results of clinical trials are conflicting. Several clinical trials did not show an additive effect of magnesium with nimodipine, another calcium antagonist which is routinely administered to SAH patients in many centers. Other trials found a protective effect after magnesium therapy. Thus, it may still be a promising substance in the treatment of secondary cerebral ischemia after aneurysmal SAH. Future prospects of magnesium therapy are discussed.

Urokinase plasminogen activator, uPAR, MMP-2, and MMP-9 in the C6-glioblastoma rat model.

BACKGROUND: In glioblastoma multiforme (GBM), the serine protease urokinase plasminogen activator (uPA), and matrix metalloproteases (MMP-2/MMP-9) contribute to its invasive growth pattern, which is the major obstacle to successful surgical treatment. MATERIALS AND METHODS: The expression of uPA was determined in monolayers and spheroids of the rodent GBM cell line C6 by immunohistochemistry and polymerase chain reaction (PCR). The longitudinal expression of proteases was studied in orthotopically implanted spheroids by semi-quantitative immunohistochemistry (IHC) in Sprague Dawley rats (n=40). The tumor volume was monitored by magnetic resonance imaging (MRI). RESULTS: In vitro, the GBM cell line C6 expresses high levels of uPA. In vivo, a continuous increase of uPA, uPA-receptor (uPAR), MMP-2, and MMP-9 expression was found in the infiltration zone. uPA was located exclusively in the infiltration zone and in the vascular basal layers. The mean tumor volume 23 days after implantation was 3.2 mm3. CONCLUSION: uPA, uPAR, MMP-2 and MMP-9 play an important role in GBM growth. Blockade of uPA and interruption of the proteolytic cascade could become a useful tool in the therapy of GBM.

A complete compilation of matrix metalloproteinase expression in human malignant gliomas.

Glioblastomas are characterized by an aggressive local growth pattern, a marked degree of invasiveness and poor prognosis. Tumor invasiveness is facilitated by the increased activity of proteolytic enzymes which are involved in destruction of the extracellular matrix of the surrounding healthy brain tissue. Elevated levels of matrix metalloproteinases (MMPs) were found in glioblastoma (GBM) cell-lines, as well as in GBM biopsies as compared with low-grade astrocytoma (LGA) and normal brain samples, indicating a role in malignant progression. A careful review of the available literature revealed that both the expression and role of several of the 23 human MMP proteins is controversely discussed and for some there are no data available at all. We therefore screened a panel of 15 LGA and 15 GBM biopsy samples for those MMPs for which there is either no, very limited or even contradictory data available. Hence, this is the first complete compilation of the expression pattern of all 23 human MMPs in astrocytic tumors. This study will support a better understanding of the specific expression patterns and interaction of proteolytic enzymes in malignant human glioma and may provide additional starting points for targeted patient therapy.

Prolonged survival when temozolomide is added to accelerated radiotherapy for glioblastoma multiforme.

BACKGROUND: The goal of this study was to evaluate accelerated radiotherapy with and without temozolomide (TMZ) for glioblastoma multiforme (GBM). METHODS: This retrospective analysis evaluated 86 patients with histologically proven GBM who were treated with accelerated radiotherapy of 1.8 Gy twice daily to a total dose of 54 Gy within 3 weeks. Median age was 62 years and median Karnofsky index was 90. A total of 41 patients received radiotherapy only from 2002-2005 and 45 patients were treated with TMZ concomitantly and after radiotherapy from 2005-2007. RESULTS: Median overall survival (OS) was 12.5 months and 2-year OS was 15.4%. Patient characteristics were well balanced between the two groups except for better performance status (p = 0.05) and higher frequency of retreatment for the first recurrence (p = 0.02) in the TMZ group. Age at diagnosis (HR 2.83) and treatment with TMZ (HR 0.60) were correlated with OS in the multivariate analysis: treatment with and without TMZ resulted in median OS of 16 months and 11.3 months, respectively. Hematological toxicity grade > II was observed in 2/45 patients and 5/37 patients during simultaneous radiochemotherapy and adjuvant TMZ. CONCLUSION: TMZ added to accelerated radiotherapy for GBM resulted in prolonged overall survival with low rates of severe hematological toxicity.

The cohesin-interacting protein, precocious dissociation of sisters 5A/sister chromatid cohesion protein 112, is up-regulated in human astrocytic tumors.

Glioblastoma multiforme (GBM) is the most prevalent, highly malignant, invasive and difficult-to-treat primary brain tumor in adults. At the genetic level, it is characterized by a high degree of chromosomal instability and aneuploidy. It has been shown that defects in the mitotic spindle checkpoint could lead to the development of aneuploidy as well as tumorigenesis. Additional proteins regulating sister chromatid cohesion could also be involved in maintaining the fidelity of chromosome segregation. One such protein is the precocious dissociation of sisters 5A (Pds5A), also known as sister chromatid cohesion protein 112. It is a nuclear protein, expressed from the S right through to the mitotic phase. It is highly conserved from yeast to man and plays a role in the establishment, maintenance and dissolution of sister chromatid cohesion. The mutation of Pds5A orthologs in lower organisms results in chromosome missegregation, aneuploidy and DNA repair defects. It is considered that such defects can cause either cell death or contribute to the development of cancer cells. Indeed, altered expression levels of Pds5A have been observed in tumors of the breast, kidney, oesophagus, stomach, liver and colon. Malignant gliomas, however, have not been analysed so far. Herein, we report on the cloning of Rattus norvegicus Pds5A and on the analysis of its expression pattern in rat tissue. We also show that Pds5A is significantly overexpressed at both the mRNA and protein level and that this overexpression correlates positively with the WHO grade of human gliomas. However, functional assays show that the siRNA-mediated knockdown of Pds5A affects sister chromatid cohesion but does not influence mitotic checkpoint function or the proliferation and survival of GBM cells. Although the mechanism by which Pds5A functions in GBM cells remains unclear, its overexpression in high grade gliomas implies that it could play a pivotal role during the development and progression of astrocytic tumors.

Favorable outcome in the elderly cohort treated by concomitant temozolomide radiochemotherapy in a multicentric phase II safety study of 5-ALA.

The primary objective of this augmental, prospective, uncontrolled phase II multicentre trial was to assess adverse events (AE) associated with malignant glioma resection using 5-aminolevulinic (5-ALA). During accrual, the standard of adjuvant therapy changed to concomitant radiochemotherapy with adjuvant temozolomide (RT/TMZ). Thus, this study also provided a platform for investigating the influence of RT/TMZ on survival in patients with fluorescence-guided resections. Malignant glioma patients, aged 18-75 years and with a Karnofsky performance score (KPS) ≥70%, were eligible. Data were collected on adverse events, KPS, survival and adjuvant therapies. In 243 patients evaluable for safety, 6-week AE incidence was 51.9% (nervous system disorders: 30.0%). Three patients experienced four possibly drug-related AEs. Grade III/IV incidence was 18.9% (nervous system disorders: 10.7%). About 48 h after surgery, AE incidence was 26.3% (9.9% grade III/IV), which was related to overall survival. A total of 219 patients (glioblastoma 206; anaplastic astrocytoma: 13) qualified for efficacy analysis. Median overall survival was 14.1 months (95% CI: 12.0-16.6), but 16.3 (13-19.2) months in 122 glioblastoma patients receiving RT/TMZ compared to 11.9 (9.6-14.1) months in the remaining 84 patients (P = 0.0194). Older patients (≥60 years) had less adjuvant therapies than younger patients. Median survival of older glioblastoma patients with RT/TMZ was also significantly prolonged (16.3; 12.0-17.2 months vs. 11.2; 7.4-14.1, hazard ratio = 0.55; 0.32-0.92). Risks of surgery were similar to past experiences with 5-ALA. Ancillary analyses demonstrated surgical glioblastoma patients, including the elderly, to have derived benefit from RT/TMZ. Thus, older patients should not generally be excluded from accepted therapies (fluorescence-guided resection plus RT/TMZ).

Comparative expression pattern of Matrix-Metalloproteinases in human glioblastoma cell-lines and primary cultures.

BACKGROUND: Glioblastomas (GBM), the most frequent malignant brain tumors in adults, are characterized by an aggressive local growth pattern and highly invasive tumor cells. This invasion is facilitated by expression of matrix metalloproteinases (MMPs), a family of zinc-dependent endopeptidases. They mediate the degradation of protein components of the extracellular matrix. Twenty-three family members are known. Elevated levels of several of them have been reported in GBM. GBM cell-lines are used for in vitro studies of cell migration and invasion. Therefore, it is essential to know their MMP expression patterns. Only limited data for some of the cell-lines are published, yet. To fill the gaps in our knowledge would help to choose suitable model systems for analysis of regulation and function of MMPs during GBM tumorigenesis, cell migration and invasion. FINDINGS: We analysed MMP-1, -8, -9, -10, -11, -13, -17, -19, -20, -21, -23, -24, -26, -27, and MMP-28 expression in seven GBM cell-lines (SNB-19, GaMG, U251, U87, U373, U343, U138) and in four primary cell cultures by semiquantitative RT-PCR, followed changes in the MMP expression pattern with increasing passages of cell culture and examined the influence of TNF-α and TGF-ß1 stimulation on the expression of selected MMPs in U251 and U373 cells.MMP-13, -17, -19 and -24 were expressed by all analyzed cell-lines, whereas MMP-20 and MMP-21 were not expressed by any of them. The other MMPs showed variable expression, which was dependent on passage number. Primary cells displayed a similar MMP-expression pattern as the cell-lines. In U251 and U373 cells expression of MMP-9 and MMP-19 was stimulated by TNF-α. MMP-1 mRNA expression was significantly increased in U373 cells, but not in U251 cells by this cytokine. Whereas TGF-ß1 had no impact on MMP expression in U251 cells, it significantly induced MMP-11 and MMP-24 expression in U373 cells. CONCLUSIONS: Literature-data and our own results suggest that the expression pattern of MMPs is highly variable, dependent on the cell-line and the cell-culture conditions used and that also regulation of MMP expression by cytokines is cell-line dependent. This is of high impact for the transfer of cell-culture experiments to clinical implementation.

Prophylactic intravenous magnesium sulfate for treatment of aneurysmal subarachnoid hemorrhage: a randomized, placebo-controlled, clinical study.

OBJECTIVE: To examine whether the maintenance of elevated magnesium serum concentrations by intravenous administration of magnesium sulfate can reduce the occurrence of cerebral ischemic events after aneurysmal subarachnoid hemorrhage. DESIGN: Prospective, randomized, placebo-controlled study. SETTING: Neurosurgical intensive care unit of a University hospital. INTERVENTIONS: One hundred ten patients were randomized to receive intravenous magnesium sulfate or to serve as controls. Magnesium treatment was started with a bolus of 16 mmol, followed by continuous infusion of 8 mmol/hr. Serum concentrations were measured every 8 hrs, and infusion rates were adjusted to maintain target levels of 2.0-2.5 mmol/L. Intravenous administration was continued for 10 days or until signs of vasospasm had resolved. Thereafter, magnesium was administered orally and tapered over 12 days. MEASUREMENTS AND MAIN RESULTS: Delayed ischemic infarction (primary end point) was assessed by analyzing serial computed tomography scans. Transcranial Doppler sonography and digital subtraction angiography were used to detect vasospasm. Delayed ischemic neurologic deficit was determined by continuous detailed neurologic examinations; clinical outcome after 6 months was assessed using the Glasgow outcome scale. Good outcome was defined as Glasgow outcome scale score 4 and 5.The incidence of delayed ischemic infarction was significantly lower in magnesium-treated patients (22% vs. 51%; p = .002); 34 of 54 magnesium patients and 27 of 53 control patients reached good outcome (p = .209). Delayed ischemic neurologic deficit was nonsignificantly reduced (9 of 54 vs. 15 of 53 patients; p = .149) and transcranial Doppler-detected/angiographic vasospasm was significantly reduced in the magnesium group (36 of 54 vs. 45 of 53 patients; p = .028). Fewer patients with signs of vasospasm had delayed cerebral infarction. CONCLUSION: These data indicate that high-dose intravenous magnesium can reduce cerebral ischemic events after aneurysmal subarachnoid hemorrhage by attenuating vasospasm and increasing the ischemic tolerance during critical hypoperfusion.

An anatomical assessment of the supracerebellar midline and paramedian approaches to the inferior colliculus for auditory midbrain implants using a neuronavigation model on cadaveric specimens.

The inferior colliculus (IC) is an alternative site for electrode placement in neural deafness due to its surgical accessibility and its well-known tonotopic stratification. In patients where tumor surgery has already occurred and the cerebellopontine angle contains scar tissue or tumor-remnants, midline and paramedian supracerebellar approaches are alternative routes. They are often avoided due to concerns regarding the venous drainage of the cerebellum, the electrode trajectory and the course of the electrode cable. We studied these surgical routes in five neuronavigated fixed cadaveric specimens. For paramedian and midline approaches, the transverse sinus was exposed 5.8mm on average. A mean of 1.6 cerebellar veins, with an average diameter of 2.0mm, draining to the tentorium were transected to reach the tentorial notch. Only 0.4 arterial branches were met. We conclude that the supracerebellar midline and paramedian approaches provide a good exposure of the IC and offer safe and viable alternative routes to the IC. Additionally, they provide a wider angle of action for optimal electrode placement.

CD8+ T-cell clones dominate brain infiltrates in Rasmussen encephalitis and persist in the periphery.

Rasmussen encephalitis (RE) is a rare neurological disorder of childhood characterized by uni-hemispheric inflammation, progressive neurological deficits and intractable focal epilepsy. Destruction of neurons and astrocytes by cytotoxic CD8 T cells has been proposed as a pathogenic mechanism underlying this enigmatic disorder. We tested this hypothesis by analysing the clonal composition and T-cell receptor (TCR) repertoire of CD4+ and CD8+ T cells using complementarity determining region 3 (CDR3) spectratyping from peripheral blood and corresponding CNS specimens. Severe perturbations of the TCR repertoire were found in brain infiltrates from all specimens (n = 5). Clonal expansions, as evidenced by peripheral blood analysis (n = 14), belonged to the CD8+ T-cell subset, while CD4+ cells showed normal distributions. Some of those expansions were analysed in the respective CNS specimens by histochemistry. The stainings showed Vbeta specific T cells containing the cytotoxic molecule granzyme B and lying in close appositions to NeuN+ neurons and GFAP+ astrocytes. Analysis of corresponding CNS/blood specimens revealed overlapping but also CNS-restricted expansions of certain TCR clonotypes suggesting expansions of T cells within the target organ itself. Longitudinal analysis of peripheral blood samples (n = 5) demonstrated dominance but also longitudinal persistence of specific CD8 T-cell clones over time. The Vbeta/Jbeta usage, length of the CDR3, and biochemical characteristics of the CDR3 amino acids suggested high similarities putatively related to common driving antigen(s) without shared clones. Taken together, our data strongly support the hypothesis of an antigen-driven MHC class-I restricted, CD8+ T cell-mediated attack against neurons and astrocytes in the CNS dominating the pathogenesis in RE.