MGMT promoter methylation status and prognosis of patients with primary or recurrent glioblastoma treated with carmustine wafers

The prognostic role of O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma patients treated with carmustine (BCNU) wafer implantation is unclear. Here, we report on a retrospective study of 47 patients with either newly diagnosed (30 patients) or recurrent (17 patients) glioblastoma (WHO grade IV) treated with BCNU (bis-chloroethylnitrosourea) wafers. Thirteen of the newly diagnosed patients received local BCNU and irradiation only (first-line BCNU), while 17 patients additionally received concomitant and adjuvant temozolomide (TMZ) radiochemotherapy (first-line BCNU + TMZ). Of the 17 patients treated for recurrent glioblastoma (second-line BCNU), 16 had received radiotherapy with concomitant and adjuvant TMZ as an initial treatment. Median overall survival (OS) did not significantly differ between 19 patients with MGMT promoter methylated tumors when compared to 28 patients with unmethylated tumors (18.9 vs 15.0 months; p = 0.1054). In the first-line BCNU + TMZ group, MGMT promoter methylation was associated with longer OS (21.0 vs 11.1 months, p = 0.0127), while no significant survival differences were detected in the other two subgroups. Progression-free survival did not significantly differ between patients with and without MGMT promoter methylated tumors in the entire patient cohort or any of the three subgroups. The first-line BCNU + TMZ group showed no significant difference in OS when compared to the first-line BCNU group (18.9 vs 14.7 months), but tended to have more therapy-related adverse effects (53% vs 24%, p = 0.105). In summary, MGMT promoter methylation showed a non-significant trend toward longer survival in our patient cohort. The combination of TMZ radiochemotherapy with local delivery of BCNU did not provide a significant survival benefit compared to local BCNU alone, but was associated with a higher rate of adverse effects. Owing to the small number of patients investigated, however, these findings would need to be corroborated in larger patient cohorts.

Hotspot mutations in H3F3A and IDH1 define distinct epigenetic and biological subgroups of glioblastoma

Glioblastoma (GBM) is a brain tumor that carries a dismal prognosis and displays considerable heterogeneity. We have recently identified recurrent H3F3A mutations affecting two critical amino acids (K27 and G34) of histone H3.3 in one-third of pediatric GBM. Here, we show that each H3F3A mutation defines an epigenetic subgroup of GBM with a distinct global methylation pattern, and that they are mutually exclusive with IDH1 mutations, which characterize a third mutation-defined subgroup. Three further epigenetic subgroups were enriched for hallmark genetic events of adult GBM and/or established transcriptomic signatures. We also demonstrate that the two H3F3A mutations give rise to GBMs in separate anatomic compartments, with differential regulation of transcription factors OLIG1, OLIG2, and FOXG1, possibly reflecting different cellular origins.

Dissecting the genomic complexity underlying medulloblastoma

Medulloblastoma is an aggressively growing tumour, arising in the cerebellum or medulla/brain stem. It is the most common malignant brain tumour in children, and shows tremendous biological and clinical heterogeneity. Despite recent treatment advances, approximately 40% of children experience tumour recurrence, and 30% will die from their disease. Those who survive often have a significantly reduced quality of life. Four tumour subgroups with distinct clinical, biological and genetic profiles are currently identified. WNT tumours, showing activated wingless pathway signalling, carry a favourable prognosis under current treatment regimens. SHH tumours show hedgehog pathway activation, and have an intermediate prognosis. Group 3 and 4 tumours are molecularly less well characterized, and also present the greatest clinical challenges. The full repertoire of genetic events driving this distinction, however, remains unclear. Here we describe an integrative deep-sequencing analysis of 125 tumour-normal pairs, conducted as part of the International Cancer Genome Consortium (ICGC) PedBrain Tumor Project. Tetraploidy was identified as a frequent early event in Group 3 and 4 tumours, and a positive correlation between patient age and mutation rate was observed. Several recurrent mutations were identified, both in known medulloblastoma-related genes (CTNNB1, PTCH1, MLL2, SMARCA4) and in genes not previously linked to this tumour (DDX3X, CTDNEP1, KDM6A, TBR1), often in subgroup-specific patterns. RNA sequencing confirmed these alterations, and revealed the expression of what are, to our knowledge, the first medulloblastoma fusion genes identified. Chromatin modifiers were frequently altered across all subgroups. These findings enhance our understanding of the genomic complexity and heterogeneity underlying medulloblastoma, and provide several potential targets for new therapeutics, especially for Group 3 and 4 patients.

The need to unify neuropathological assessments of vascular alterations in the ageing brain: multicentre survey by the BrainNet Europe consortium

Here, we summarise the results after carrying out a large survey regarding the assessment of vascular alterations, both vessel changes and vascular lesions in an inter-laboratory setting. In total, 32 neuropathologists from 22 centres, most being members of BrainNet Europe (BNE), participated by filling out a questionnaire with emphasis on assessment of common vascular alterations seen in the brains of aged subjects. A certain level of harmonisation has been reached among BNE members regarding sectioning of the brain, harvesting of brain tissue for histology and staining used when compared to the survey carried out in 2006 by Pantoni and colleagues. The most significant variability was seen regarding the assessment of severity and of clinical significance of vascular alterations. Two strategies have recently been recommended regarding the assessment of vascular alterations in aged and demented subjects. The National Institute on Aging - Alzheimer's Association (NIA-AA) recommends the assessment of hippocampal sclerosis, vascular brain injury and microvascular lesions in 12 regions. Although this strategy will be easy to follow, the recommendations do not inform how the load of observed alterations should be assessed and when the observed lesions are of significance. Deramecourt and his colleagues recommend an assessment and semiquantitative grading of various pathologies in 4 brain regions. This strategy yielded a total score of 0 to 20 as an estimate of pathology load. It is, however, not clear which score is considered to be of clinical significance. Furthermore, in several BNE trials the semiquantitative assessment has yielded poor agreement rates; an observation that might negatively influence the strategy proposed by Deramecourt and his colleagues. In line with NIA-AA, a dichotomised approach of easily recognisable lesions in a standardised set of brain regions harvested for neuropathological assessment and applying reproducible sampling and staining strategies is recommended by BNE. However, a simple strategy regarding assessment of load of alteration is urgently needed to yield reproducible, and at the same time, comparable results between centres.

Driver mutations in histone H3.3 and chromatin remodelling genes in paediatric glioblastoma

Glioblastoma multiforme (GBM) is a lethal brain tumour in adults and children. However, DNA copy number and gene expression signatures indicate differences between adult and paediatric cases. To explore the genetic events underlying this distinction, we sequenced the exomes of 48 paediatric GBM samples. Somatic mutations in the H3.3-ATRX-DAXX chromatin remodelling pathway were identified in 44% of tumours (21/48). Recurrent mutations in H3F3A, which encodes the replication-independent histone 3 variant H3.3, were observed in 31% of tumours, and led to amino acid substitutions at two critical positions within the histone tail (K27M, G34R/G34V) involved in key regulatory post-translational modifications. Mutations in ATRX (α-thalassaemia/mental retardation syndrome X-linked) and DAXX (death-domain associated protein), encoding two subunits of a chromatin remodelling complex required for H3.3 incorporation at pericentric heterochromatin and telomeres, were identified in 31% of samples overall, and in 100% of tumours harbouring a G34R or G34V H3.3 mutation. Somatic TP53 mutations were identified in 54% of all cases, and in 86% of samples with H3F3A and/or ATRX mutations. Screening of a large cohort of gliomas of various grades and histologies (n = 784) showed H3F3A mutations to be specific to GBM and highly prevalent in children and young adults. Furthermore, the presence of H3F3A/ATRX-DAXX/TP53 mutations was strongly associated with alternative lengthening of telomeres and specific gene expression profiles. This is, to our knowledge, the first report to highlight recurrent mutations in a regulatory histone in humans, and our data suggest that defects of the chromatin architecture underlie paediatric and young adult GBM pathogenesis.

pH measurement as quality control on human post mortem brain tissue: a study of the BrainNet Europe consortium

AIMS

Most brain diseases are complex entities. Although animal models or cell culture experiments mimic some disease aspects, human post mortem brain tissue remains essential to advance our understanding of brain diseases using biochemical and molecular techniques. Post mortem artefacts must be properly understood, standardized, and either eliminated or factored into such experiments. Here we examine the influence of several premortem and post mortem factors on pH, and discuss the role of pH as a biochemical marker for brain tissue quality.

METHODS

We assessed brain tissue pH in 339 samples from 116 brains provided by 8 different European and 2 Australian brain bank centres. We correlated brain pH with tissue source, post mortem delay, age, gender, freezing method, storage duration, agonal state and brain ischaemia.

RESULTS

Our results revealed that only prolonged agonal state and ischaemic brain damage influenced brain tissue pH next to repeated freeze/thaw cycles.

CONCLUSIONS

pH measurement in brain tissue is a good indicator of premortem events in brain tissue and it signals limitations for post mortem investigations.

Pediatric supratentorial ependymomas show more frequent deletions on chromosome 9 than infratentorial ependymomas: a microsatellite analysis

Numerous human malignancies, including brain tumors, have been reported to show aberrations on chromosome 9. In our previous screening study in ependymomas, we used microsatellite analysis to identify frequent aberrations on this chromosome. To refine our preliminary analysis of candidate regions, here we use 15 polymorphic microsatellite markers spanning the entire chromosome 9. A total of 48 pairs of matched normal and tumor specimens from patients with ependymoma, including 28 children (mean age, 4.4 years) and 20 adults (mean age, 44.9 years), were genotyped. Allelic imbalances were found in 30/48 patients (62.5%). Pediatric tumors, which were predominantly anaplastic, showed fewer aberrations (57.1%) than adult tumors (70%), and two common regions of deletions were identified (9p21.1 approximately p22.3 and 9q31.3 approximately q33.2). We found that 9q31.3 approximately q33.2, an approximately 8.5-megabase segment containing the DCR1 gene, exhibited the highest number of aberrations (n=33). Adults with ependymomas harboring aberrations on chromosome 9 (n=14) showed significantly longer overall survival than patients of the same group without this aberration (n=6; P=0.034), irrespective of the extent of resection in multivariate analysis. Aberrations of chromosome 9, and particularly of DCR1, may play a role in the prognostic evaluation for ependymomas in adults in the future. In pediatric patients, genetic aberrations were found significantly more often in supratentorial tumors than in tumors with infratentorial location (P=0.007). This result may underscore differences in the origin of these tumors.

Staging/typing of Lewy body related alpha-synuclein pathology: a study of the BrainNet Europe Consortium

When 22 members of the BrainNet Europe (BNE) consortium assessed 31 cases with alpha-synuclein (alphaS) immunoreactive (IR) pathology applying the consensus protocol described by McKeith and colleagues in 2005, the inter-observer agreement was 80%, being lowest in the limbic category (73%). When applying the staging protocol described by Braak and colleagues in 2003, agreement was only 65%, and in some cases as low as 36%. When modifications of these strategies, i.e., McKeith's protocol by Leverenz and colleagues from 2009, Braak's staging by Müller and colleagues from 2005 were applied then the agreement increased to 78 and 82%, respectively. In both of these modifications, a reduced number of anatomical regions/blocks are assessed and still in a substantial number of cases, the inter-observer agreement differed significantly. Over 80% agreement in both typing and staging of alphaS pathology could be achieved when applying a new protocol, jointly designed by the BNE consortium. The BNE-protocol assessing alphaS-IR lesions in nine blocks offered advantages over the previous modified protocols because the agreement between the 22 observers was over 80% in most cases. Furthermore, in the BNE-protocol, the alphaS pathology is assessed as being present or absent and thus the quality of staining and the assessment of the severity of alphaS-IR pathology do not alter the inter-observer agreement, contrary to other assessment strategies. To reach these high agreement rates an entity of amygdala-predominant category was incorporated. In conclusion, here we report a protocol for assessing alphaS pathology that can achieve a high inter-observer agreement for both the assignment to brainstem, limbic, neocortical and amygdala-predominant categories of synucleinopathy and the Braak stages.

Hypothalamic papillary tumor in a patient with tuberous sclerosis

We here report an unusual tumor of the suprasellar region featuring a papillary growth pattern and cytokeratin expression in a 10-year-old boy with tuberous sclerosis. This hitherto undescribed low-grade hypothalamic tumor extends the spectrum of tumors associated with the tuberous sclerosis complex.

Management of a twenty-first century brain bank: experience in the BrainNet Europe consortium

Collections of human postmortem brains gathered in brain banks have underpinned many significant developments in the understanding of central nervous system (CNS) disorders and continue to support current research. Unfortunately, the worldwide decline in postmortem examinations has had an adverse effect on research tissue procurement, particularly from control cases (non-diseased brains). Recruitment to brain donor programmes partially addresses this problem and has been successful for dementing and neurodegenerative conditions. However, the collection of brains from control subjects, particularly from younger individuals, and from CNS disorders of sudden onset, remains a problem. Brain banks need to adopt additional strategies to circumvent such shortages. The establishment of brain bank networks allows data on, and access to, control cases and unusual CNS disorders to be shared, providing a larger resource for potential users. For the brain banks themselves, inclusion in a network fosters the sharing of protocols and development of best practice and quality control. One aspect of this collective experience concerns brain bank management, excellence in which is a prerequisite not only for gaining the trust of potential donors and of society in general, but also for ensuring equitable distribution to researchers of high quality tissue samples. This review addresses the legal, ethical and governance issues, tissue quality, and health and safety aspects of brain bank management and data management in a network, as well as the needs of users, brain bank staffing, donor programs, funding issues and public relations. Recent developments in research methodology present new opportunities for researchers who use brain tissue samples, but will require brain banks to adopt more complex protocols for tissue collection, preparation and storage, with inevitable cost implications for the future.

Correlation between 6q25.3 deletion status and survival in pediatric intracranial ependymomas

Losses and rearrangements of genetic material on chromosome 6q are frequently found in several human malignancies, including primary central nervous system tumors. We previously used microsatellite analysis of ependymomas to identify frequent deletions in regions 6q15 approximately q16, 6q21 approximately q22.1, and 6q24.3 approximately q25.3. To refine our preliminary analysis of potential prognostic regions, we used a panel of 25 microsatellite markers located between 6q15 and 6qter in 49 pairs of matched normal and tumor specimens from 28 children and 21 adults with ependymoma. Allelic deletions were detected in 34 of 49 patients (69%), and two common regions of deletions (6q24.3 and 6q25.2 approximately q25.3) were identified. A short segment of approximately 0.4 Mb between D6S1612 and D6S363 on 6q25.3, containing the SNX9 and SYNJ2 genes, exhibited the highest number of aberrations (n = 38). Pediatric tumors showed slightly fewer aberrations (64%) than adult tumors (76%) and also predominantly exhibited small interstitial deletions, in contrast to the extensive losses of genetic material in adults. Pediatric anaplastic intracranial (supra- and infratentorial) ependymomas harboring the 6q25.3 deletion (n = 9) showed significantly longer overall survival than did patients of the same group without the aberration (n = 6), independent of the extent of resection (P = 0.013). This supports the identified deletion on 6q25.3 as a candidate favorable prognostic parameter and warrants further investigation.

Staging of neurofibrillary pathology in Alzheimer's disease: a study of the BrainNet Europe Consortium

It has been recognized that molecular classifications will form the basis for neuropathological diagnostic work in the future. Consequently, in order to reach a diagnosis of Alzheimer's disease (AD), the presence of hyperphosphorylated tau (HP‐tau) and β‐amyloid protein in brain tissue must be unequivocal. In addition, the stepwise progression of pathology needs to be assessed. This paper deals exclusively with the regional assessment of AD‐related HP‐tau pathology. The objective was to provide straightforward instructions to aid in the assessment of AD‐related immunohistochemically (IHC) detected HP‐tau pathology and to test the concordance of assessments made by 25 independent evaluators. The assessment of progression in 7‐µm‐thick sections was based on assessment of IHC labeled HP‐tau immunoreactive neuropil threads (NTs). Our results indicate that good agreement can be reached when the lesions are substantial, i.e., the lesions have reached isocortical structures (stage V–VI absolute agreement 91%), whereas when only mild subtle lesions were present the agreement was poorer (I–II absolute agreement 50%). Thus, in a research setting when the extent of lesions is mild, it is strongly recommended that the assessment of lesions should be carried out by at least two independent observers.

Alterations in expression of glutamatergic transporters and receptors in sporadic Alzheimer's disease

Excitatory neurotransmitter dysfunction has been discussed to be involved in the pathophysiology of Alzheimer's disease (AD). In the current study we investigated gene and protein expression patterns of glutamatergic receptors and transporters in brains of AD patients in various stages of disease using gene chip arrays, real time PCR and immunohistochemistry. We found marked impairment in the expression of excitatory amino acid transporters (EAAT1 and EAAT 2) at both gene and protein levels in hippocampus and gyrus frontalis medialis of AD patients, already in early clinical stages of disease. The loss of EAAT immunoreactivity was particularly obvious in the vicinity of amyloid plaques. In contrast, EAAT expression was up-regulated in the cerebellum of these patients. Furthermore, a significant up-regulation of the glutamatergic kainate (GRIK4) receptor observed by gene arrays was confirmed by quantitative RT-PCR in late stages in the hippocampus of AD patients. Moreover, there were down-regulations of other glutamatergic receptors such as NMDA (GRINL1A) and AMPA (GRIA4) receptors. Our data show marked changes in the functional elements of the glutamatergic synapses such as glutamatergic receptors and transporters and indicate impaired glutamate clearing rendering neurons susceptible to excess extracellular glutamate and support further the involvement of excitotoxic mechanisms in the pathogenesis of AD.

Cytogenetic and molecular genetic analyses of giant cell glioblastoma multiforme reveal distinct profiles in giant cell and non-giant cell subpopulations

We have comparatively analyzed mechanisms associated with chromosomal and microsatellite instability in giant cell glioblastoma multiforme (gcGBM) and classic GBM. This included microsatellite instability (MSI), loss of expression of four major mismatch repair (MMR) proteins, aberrations of five chromosomes, EGFR copy number, and TP53 mutations. MSI was more frequent among gcGBM (30 vs. 7.8%, P = 0.054). TP53 mutations were more commonly observed in gcGBM (83.3%), whereas EGFR was amplified in just one gcGBM (8.3%). By tumor cell phenotype-specific cytogenetic analysis of gcGBM, increased chromosome copy numbers were identified in 72-84% of giant cells but in only 4-14% of nongiant cells; in classic GBM, intermediate frequencies were noted (11-49%). Chromosome 10 deletions were found in nongiant cells of all gcGBM cases but in only approximately 45% of the cell population in classic GBM. The present study shows a distinct pattern of cytogenetic alterations in nongiant and giant cell phenotypes in gcGBM and suggests that multinuclear giant cells evolve from nongiant tumor cells at an early tumor stage. Furthermore, the data point to differences in the profile of chromosomal and microsatellite instability in gcGBM and classic GBM that might underscore the distinct pathological features of both tumor subtypes.

Frequent but borderline methylation of p16 (INK4a) and TIMP3 in medulloblastoma and sPNET revealed by quantitative analyses

Certain risk groups among tumors of the central nervous system (CNS) in children take an almost inevitably fatal course. The elucidation of molecular mechanisms offers hope for improved therapy. Aberrant methylation is common in malignant brain tumors of childhood and may have implications for stratification and therapy. Methylation of p16 (INK4A), p14 (ARF), TIMP3, CDH1, p15 (INK4B )and DAPK1 in medulloblastoma (MB) and ependymoma has been discussed controversially in the literature. DUTT1 and SOCS1 have not previously been analyzed. We examined methylation in MB, sPNET and ependymoma using methylation-specific PCR (MSP), quantitative Combined Bisulfite Restriction Analysis (COBRA) and direct and clone sequencing of bisulfite PCR products. We detected methylation of p16 (INK4A) (17/43), p14 (ARF) (11/42) and TIMP3 (9/44) in MB and others by MSP. CDH1 was not only methylated in MB (31/41), but also in normal controls. Evaluation of MSP results by quantitative COBRA and sequencing yielded methylation between the detection limits of COBRA (1%) and MSP (0.1%). Only p16 (INK4A )and TIMP3 were methylated consistently in medulloblastomas (p16 (INK4A ) 14%, TIMP3 11%) and p16 (INK4A) also in anaplastic ependymomas (1/4 tumors). Methylation ranged from 1-5%. Evaluation of methylation using MSP has thus to be supplemented by quantitative methods. Our analyses raise the issue of the functional significance of low level methylation, which may disturb the delicate growth factor equilibrium within the cell. Therapeutic and diagnostic implications urge into depth analyses of methylation as a mechanism, which might fill some of the gaps of our understanding of brain tumor origin.

Further evidence for a somatic KRAS mutation in a pilocytic astrocytoma

Astrocytomas are the most common brain tumors of childhood. However, knowledge of the molecular etiology of astrocytomas WHO grade I and II is limited. Germline mutations in the Ras-guanosine triphosphatase-activating protein, neurofibromin, in individuals with neurofibromatosis type I predispose to pilocytic astrocytomas. This association suggests that constitutive activation of the Ras signaling pathway plays a fundamental role in astrocytoma development. We screened 25 WHO I and II astrocytomas for mutations of PTPN11, NRAS, KRAS, and HRAS genes and identified the somatic G12A KRAS mutation in one pilocytic astrocytoma. These data suggest that Ras is rarely mutated in these tumors. Analyzed astrocytomas without mutations in Ras or neurofibromin may harbor mutations in other proteins of this pathway leading to hyperactive Ras signaling.

Ependymoma gene expression profiles associated with histological subtype, proliferation, and patient survival

Ependymomas are primary tumors of the central nervous system that typically originate from the walls of the cerebral ventricles or from the spinal canal. The pathogenesis of these tumors is poorly understood, and prognostic assessment based on histologic features and clinical parameters is difficult. The aim of this study was to investigate the molecular heterogeneity of ependymomas. We used cDNA microarrays and RT-PCR to examine gene expression in 47 ependymomas. We present results for five comparisons: (1) tumors from children and adults with poor versus favorable outcome, (2) tumors from children with poor versus favorable outcome, (3) tumors with high versus low proliferation indices, (4) subependymomas versus myxopapillary ependymomas, and (5) spinal versus intracranial ependymomas. For patients with an overall survival >10 years after diagnosis, we identified 27 genes associated with favorable prognosis. In contrast, overexpression of BNIP3, MRC1, EPHB3, GLIS3, CDK4, COL4A2, EBP, NRCAM, and CCNA1 genes in tumors with high proliferation indices was associated with a poor outcome. Thirty genes, including ETV6, YWHAE, TOP2A, TLR2, IRAK1, TIA1, and UFD1L were found to be highly expressed in subependymomas but not myxopapillary ependymomas. Also, 30 genes were differentially expressed in spinal versus intracranial ependymomas. There was no relationship between expression profiles and tumor grade, patient age, and patient gender. Our results provide insight into specific molecular events underlying ependymoma tumorigenesis and may contribute to more accurate diagnosis and prediction of clinical outcome.

Neuronal and ependymal expression of selenoprotein P in the human brain

Selenoprotein P (SePP) is central to selenium (Se) metabolism in the mammalian organism. Human SePP contains 10 Se atoms that are covalent constituents of the polypeptide chain incorporated as the rare amino acid selenocysteine (Sec). Since hepatocytes secrete SePP into plasma, SePP is commonly regarded as a Se transport protein, although SePP mRNA is expressed in many organs. Gene targeting of SePP in mice leads to neurological dysfunction resulting from Se deficiency and associated reduction of selenoenzyme activities in the brain. However, more recent data revealed that isolated hepatic SePP deficiency does not alter brain Se levels, suggesting a role for SePP locally expressed in the brain. Some of the best characterized and most abundant selenoenzymes, glutathione peroxidases, thioredoxin reductases, and methionine sulfoxide reductase B, play major roles in the cellular defense against reactive oxygen species. Therefore, it was hypothesized that reduced brain Se bioavailability may be involved in the pathogenesis of neurodegenerative disease and normal ageing. We present evidence that human CSF contains SePP and that the human brain expresses SePP mRNA. Moreover, SePP-like immunoreactivity localizes to neurons and ependymal cells and thus appears strategically situated for maintenance and control of Se-dependent anti-oxidative defense systems.

How a neuropsychiatric brain bank should be run: a consensus paper of Brainnet Europe II

The development of new molecular and neurobiological methods, computer-assisted quantification techniques and neurobiological investigation methods which can be applied to the human brain, all have evoked an increased demand for post-mortem tissue in research. Psychiatric disorders are considered to be of neurobiological origin. Thus far, however, the etiology and pathophysiology of schizophrenia, depression and dementias are not well understood at the cellular and molecular level. The following will outline the consensus of the working group for neuropsychiatric brain banking organized in the Brainnet Europe II, on ethical guidelines for brain banking, clinical diagnostic criteria, the minimal clinical data set of retrospectively analyzed cases as well as neuropathological standard investigations to perform stageing for neurodegenerative disorders in brain tissue. We will list regions of interest for assessments in psychiatric disorder, propose a dissection scheme and describe preservation and storage conditions of tissue. These guidelines may be of value for future implementations of additional neuropsychiatric brain banks world-wide.

Glioblastoma multiforme with oligodendroglial component (GBMO): favorable outcome after post-operative radiotherapy and chemotherapy with nimustine (ACNU) and teniposide (VM26)

BACKGROUND

The presence of an oligodendroglial component within a glioblastoma multiforme (GBM) is considered a prognostically favorable factor, but the clinical outcome of patients with glioblastoma multiforme with oligodendroglial component (GBMO) after combined post-operative radiotherapy and chemotherapy has rarely been reported.

METHODS

We analyzed overall and progression-free survival in a group of ten consecutive patients initially diagnosed with GBMO between 1996 and 2004 (4.2% of all GBM patients). Median (range) age was 54 (34-73) years, 90% were resected and median radiotherapy dose was 54 (45-60.6) Gy. 80% of patients received post-operative chemotherapy with nimustine (ACNU) and VM26 (teniposide) for a median of 3.5 (1-6) cycles, the remainder were treated with post-operative radiotherapy alone. All specimens were reviewed by an experienced neuropathologist.

RESULTS

Neuropathological re-evaluation revealed GBM with an oligodendroglial component of 30% or less in five cases, predominant oligoastrocytic tumors with focal areas of GBM in four patients and WHO grade III oligoastrocytoma with questionable transition to GBM in one patient. Four of ten patients were alive at at 40, 41, 41 and 82 months. The median overall survival (Kaplan-Meier) was 26 months, the 2-year survival rate was 60% (progression-free survival: 9.8 months and 40%, respectively).

CONCLUSION

In conclusion, patients with GBMO treated with post-operative radiotherapy and chemotherapy with ACNU/VM26 had a better prognosis than reported for GBM in modern chemoradiation series.

Interlaboratory comparison of assessments of Alzheimer disease-related lesions: a study of the BrainNet Europe Consortium

This interlaboratory study evaluated the reproducibility of the assessments of neuritic plaques and neurofibrillary tangles (NFTs)--the hallmark lesions of Alzheimer disease--and compared the staining between the BrainNet Europe centers. To reduce the topography-related inconsistencies in assessments, we used a 2-mm tissue microarray (TMA) technique. The TMA block included 42 core samples taken from 21 paraffin blocks. The assessments were done on Bielschowsky and Gallyas silver stains using an immunohistochemical (IHC) method with antibodies directed to beta-amyloid (IHC/Abeta) and hyperphosphorylated tau (IHC/HPtau). The staining quality and the assessments differed between the participants, being most diverse with Bielschowsky (good/acceptable stain in 53% of centers) followed by Gallyas (good/acceptable stain in 57%) and IHC/Abeta (good/acceptable stain in 71%). The most uniform staining quality and assessment was obtained with the IHC/HPtau method (good/acceptable stain in 94% of centers). The neuropathologic diagnostic protocol (Consortium to Establish a Registry for Alzheimer Disease, Braak and Braak, and the National Institute of Aging and Reagan [NIA-Reagan] Institute) that was used significantly influenced the agreement, being highest with NIA-Reagan (54%) recommendations. This agreement was improved by visualization of NFTs using the IHC/HPtau method. Therefore, the IHC/HPtau methodology to visualize NFTs and neuropil threads should be considered as a method of choice in a future diagnostic protocol for Alzheimer disease.

Biological activity of paediatric cerebral cavernomas: an immunohistochemical study of 28 patients

OBJECTIVE

According to the hypothesis that paediatric cerebral cavernomas may have different biological activity compared to adult cavernomas, immunohistochemical analysis was used to elucidate the biological nature of paediatric cavernomas.

PATIENTS AND METHODS

We examined the histological features and the proliferative and angiogenic capacity of the tissue specimens acquired from 28 paediatric patients. Normal paediatric brain tissues obtained from paediatric autopsy cases were used as a control group. The proliferative activity of the endothelium and the neoangiogenetic capacity were investigated by immunohistochemistry for proliferating cell nuclear antigen (PCNA), Ki-67 epitope (MIB-1), Flk-1 receptor, vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1 alpha, and endoglin antibody, respectively. Afterwards, the results of the paediatric lesions were analysed and compared with the correspondent values of previously reported immunohistochemical analysis in adult cavernomas.

RESULTS

Positive immunostaining of VEGF was detected significantly less in paediatric cavernomas compared to adult cases (p<0.05). In contrast, endoglin, a protein that is upregulated during an increased vascular shear stress, was expressed more often in paediatric cavernomas (p<0.05). Neither the expression of the PCNA nor the expression of the HIF-1alpha was found significantly different between paediatric and adult cavernomas. However, the positive immunoreaction for MIB-1 occurred more often in the paediatric cases (p<0.05).

CONCLUSIONS

The immunohistochemical study indicates that paediatric cavernomas are dynamic lesions. The VEGF/Flk-1 associated neoangiogenesis may play a minor role for the biology of paediatric cavernomas, while endoglin seems to act more prominently than previously thought, particularly for the biology of paediatric cavernomas.

Epigenetic repression of RASSF1A but not CASP8 in supratentorial PNET (sPNET) and atypical teratoid/rhabdoid tumors (AT/RT) of childhood

Supratentorial primitive neuroectodermal tumors (sPNET) and atypical teratoid/rhabdoid tumors (AT/RT) of the CNS represent a biological and clinical enigma, despite advances in both molecular techniques and clinical management for these two rare embryonal brain tumors of childhood. Epigenetic changes hold great potential as possible disease mechanisms and may be manipulated therapeutically. We thus studied aberrant methylation of the genes RASSF1A and CASP8 and its consequence on expression in cell lines and primary tumors using a combination of semiquantitative methylation specific PCR (MSP), bisulfite sequencing and RT-PCR. In all, 17 samples of autopsy-derived normal appearing brain served as controls. Opposed to control tissues 19/24 sPNET and 4/6 AT/RT demonstrated aberrant methylation for the RASSF1A promoter region. Treatment of cell lines using 5-Aza-2'-deoxycytidine (5AZA) alone or in combination with trichostatin A (TSA) succeeded in re-establishing expression of RASSF1A in cell lines derived from a renal rhabdoid, an AT/RT and a medulloblastoma. A 5' CpG-rich region of CASP8 was methylated in normal tissues and in tumors. However, CASP8 showed inconsistent expression patterns in normal and tumor tissues. Our results indicate that aberrant methylation of the RASSF1A promoter region may be of importance in the origin and progression of sPNET and AT/RT while the analysed 5'-CpG rich region of the CASP8 gene does not seem to play an important role in these tumors. Further studies of epigenetic changes in these rare tumors are warranted as their biology remains obscure and treatment efforts have been rather unsuccessfull.

[Dementia with argyrophilic grains]

Dementia with argyrophilic grains (AG) is a neuropathologically defined potentially dementing disease of advanced age which was first described by H. and E. Braak in 1987. It is often combined with histopathological signs of Alzheimer's disease but has nevertheless to be considered as a distinct entity since pure bona fide cases have been reported. Clinically it may resemble either Alzheimer's or Pick's disease; it is almost exclusively confined to patients older than 60 years and progresses slowly but relentlessly. Repeatedly prominent behavioral disorders were pointed out. Useful therapeutic regimens are not available at present but acetylcholinesterase inhibitors have proven effective in some cases and amantadines as well as dopamine agonists hold some promise from a theoretical perspective, too. The diagnosis can be ascertained only by histopathological examination. For the clinician it is important to know that this disease is to be considered as an additional and differential diagnosis of both Alzheimer's disease and the frontotemporal dementias. It must be counted among the tauopathies. This review is supplemented by a detailed case report.

Gene expression profiling of parkinsonian substantia nigra pars compacta; alterations in ubiquitin-proteasome, heat shock protein, iron and oxidative stress regulated proteins, cell adhesion/cellular matrix and vesicle trafficking genes

Gene expression profiling of human substantia nigra pars compacta (SNpc) from Parkinson's disease (PD) patients, was examined employing high density microarrays. We identified alterations in the expression of 137 genes, with 68 down regulated and 69 up regulated. The down regulated genes belong to signal transduction, protein degradation (e.g. ubiquitin-proteasome subunits), dopaminergic transmission/metabolism, ion transport, protein modification/phosphorylation and energy pathways/glycolysis functional classes. Up-regulated genes, clustered mainly in biological processes involving cell adhesion/cytoskeleton, extracellular matrix components, cell cycle, protein modification/phosphorylation, protein metabolism, transcription and inflammation/stress (e.g. key iron and oxygen sensor EGLN1). One major finding in the present study is the particular decreased expression of SKP1A, a member of the SCF (E3) ligase complex specifically in the substantia nigra (SN) of sporadic parkinsonian patients, which may lead to a wide impairment in the function of an entire repertoire of proteins subjected to regulatory ubiquitination. These findings reveal novel players in the neurodegenerative scenario and provide potential targets for the development of novel drug compounds.

Metabolic Patterns in Meningiomas

The aim of this investigation was to define characteristic properties of cellular energy metabolism in meningiomas in vitro dependent on the histological subtype. We analysed marker enzymes of representative metabolic pathways localized in the mitochondria (respiratory chain, citric acid cycle, beta-oxidation of fatty acids) and in the cytoplasm (glycolysis, pentose phosphate shunt). The activities of the intramitochondrial enzymes were significantly reduced in the meningiomas compared to normal cortex tissue. Glycolytic enzymes were not significantly different, but the marker enzyme of the pentose phosphate shunt was increased by a factor of 3.5-6 in the tumours. Further analysis of the histological subtypes showed that phosphofructokinase and lactate dehydrogenase were significantly increased in the anaplastic meningiomas compared to the benign subtypes.

Human ependymomas reveal frequent deletions on chromosomes 6 and 9

Ependymomas are glial tumors of the brain and spinal cord. Genetic aberrations associated with the development of these tumors have not been fully identified yet. In previous cytogenetic and comparative genomic hybridization studies, multiple genomic imbalances in ependymomas were found, including partial or whole chromosome losses (1p, 4q, 6q, 9, 10, 11, 13, 16, 17, 19q, 20q and 22q). The aim of this study was to map particularly the commonly affected regions in ependymomas. Thirty-three pairs of matched normal and tumor specimens from ependymoma patients were genotyped using 34 polymorphic microsatellite markers distributed over 15 chromosomes. Loss of heterozygosity (LOH) was found in 26 of 33 tumors (78.8%). The most frequent LOHs were found on the long arms of chromosomes 6 (30.3%) and 9 (27.3%). LOH was also detected on 3p14 (13.3%), 10q23 (10.3%) and 11q (18.2%). Because of the high percentage of LOH on chromosome 6 and 9, we conclude that important tumor suppressor genes are situated on these two chromosomes.

Primary anaplastic large cell lymphoma of the central nervous system: prognostic effect of ALK-1 expression

Anaplastic large cell lymphoma (ALCL) rarely occurs in the central nervous system. Although defined by its composition of large, pleomorphic, CD30-positive lymphocytes, ALCL is heterogeneous. Most are T cell but some are null cell. Most but not all have a characteristic 2:5 translocation producing the fusion protein ALK-1, which is reliably detected by immunohistochemistry. In systemic ALCL, ALK-1 expression correlates with young patient age and a favorable prognosis. Herein we report four new cases of primary central nervous system ALCL from the Mayo Clinic and incorporate additional data from five previously published cases. ALK-1 expression was determined in all nine tumors. Patient age was 4-66 years (mean 29 years) with a bimodal distribution: 6 < or = 22 years, 3 > or = 50 years. Six were female. Tumors were mostly supratentorial, five were multifocal, and seven had involvement of dura or leptomeninges. Seven tumors were T cell, two were null cell, and five of nine were ALK-1 immunopositive. Total mortality was six of nine. Three patients, 4-18 years of age (mean 13 years), were alive at 4.8-6.1 years postdiagnosis; these tumors were all ALK positive. Five patients, 13-66 years of age (mean 43 years), died of tumor 4 days to 11 weeks postdiagnosis; four of five of these tumors were ALK negative. One 10-year-old child with an ALK-positive tumor died of sepsis, but in remission. Central nervous system ALCL is aggressive. Our study suggests that a better outcome may be associated with young age and ALK-1 positivity, prognostic parameters similar to systemic ALCL.

Neuroleptic malignant syndrome in Kufs' disease

A patient with adult neuronal ceroid lipofuscinosis (ANCL; Kufs' disease) is described in whom neuroleptic malignant syndrome occurred, initially presenting as catatonic syndrome. Comprehensive neuroimaging studies were conducted including FDG-PET, IBZM-SPECT, and beta-CIT-SPECT, electrophysiological examinations and an ex vivo contracture test exposing muscle biopsy specimens to neuroleptics. Collectively the results argued for an involvement of the muscle in neuroleptic malignant syndrome at least in ANCL.

[Rhabdoid meningioma. A new malignant subtype]

Of the numerous morphological variants of meningiomas only few, and among these the rhabdoid meningioma, have prognostic importance. Rhabdoid meningiomas were described for the first time in 1998 as an unusual variant with increased proliferative activity. In 2000 they have been included in the revised WHO classification of tumours of the CNS as a subtype of meningiomas with increased risk of recurrence and more aggressive growth, corresponding to WHO grade III. We report the case of a rhabdoid meningioma in a 21-year-old woman presenting as a intracerebral tumour mimicking an oligodendroglioma. The tumour showed features of a meningioma and a rhabdoid morphology with angiomatous components and was considered to be a rhabdoid meningioma. After surgery a small residual tumour remained. The patient received postoperative radiotherapy resulting in regression of the residual tumour in control examinations after 4 and 8 months. Using the presented case we discuss the differential diagnosis and prognostic significance of recognition of a rhabdoid meningioma.

Expression of foetal type acetylcholine receptor is restricted to type 1 muscle fibres in human neuromuscular disorders

In adult muscle, acetylcholine receptors (AChR) are restricted mainly to the motor endplate where the adult isoform (alphabetadeltaepsilon) is expressed. When skeletal muscle is denervated in animal models, there is atrophy of the muscle and a marked increase in expression of the AChR foetal isoform (alphabetagammadelta) containing a gamma-subunit. Similar changes in AChR expression are thought to occur in human muscle. While the role of denervation in regulating AChR gene expression has been widely studied, it has not been determined whether the transcriptional programmes responsible for defining different fibre types have an impact on the expression of AChR genes. We investigated biopsies from patients with a wide spectrum of neuromuscular diseases for expression of the AChR alpha- and gamma-subunits using RNase protection assays, alpha/gamma-duplex reverse transcriptase polymerase chain reaction, immunohistochemistry for foetal AChR and RNA in situ hybridization. Muscle from all patients with neurogenic disorders and, to a lesser extent, myogenic disorders, exhibited markedly increased transcription of the AChR gamma-subunit but, in contrast to previous animal studies, did not show increased AChR alpha-subunit. Moreover, both immunohistochemistry and RNA in situ hybridization revealed that AChR gamma-subunit hyperexpression occurred exclusively in atrophic type 1 and not in atrophic type 2 muscle fibres, irrespective of the underlying neuromuscular disease. We conclude that up-regulation of the AChR gamma-subunit in human muscle disorders is restricted to type 1 muscle fibres and, therefore, that AChR gamma-subunit expression is controlled by a muscle fibre type-restricted transcriptional programme. The factors influencing expression of this and other functional proteins should be relevant to the understanding and treatment of a range of neuromuscular disorders.

Echogenicity of the substantia nigra: association with increased iron content and marker for susceptibility to nigrostriatal injury

BACKGROUND

Patients with Parkinson disease characteristically exhibit an increased echogenicity of the substantia nigra (SN) on transcranial sonography, a new neuroimaging technique. The same echo feature of the SN can be identified in 9% of healthy adults.

OBJECTIVE

To evaluate the relevance of the echogenic SN in healthy adults.

DESIGN

In the first part of the study, 10 healthy subjects younger than 40 years with a distinct SN hyperechogenicity underwent extensive neurological, motor, neuropsychological, and fluorine 18-dopa positron emission tomographic ([18F]-dopa PET) examinations. Results were compared with those of 10 subjects with a low echogenic SN. In the second part of the study, the postmortem brains of 20 patients without extrapyramidal disorders during their lifetime were sonographically examined with a particular focus on SN echogenicity. Subsequently, one half of the brain was prepared for heavy metal analysis, the other for a histological examination.

RESULTS

Healthy subjects with SN hyperechogenicity exhibited a significant reduction of the [18F]-dopa uptake, especially in the putamen (Wilcoxon matched pair test: left side, P =.006; right side, P =.009), whereas their neuropsychological and motor performance were normal. Postmortem studies showed that the echogenicity of the SN correlated with its iron content.

CONCLUSIONS

Increased echogenicity of the SN, characteristically seen in Parkinson disease, is related to a functional impairment of the nigrostriatal system (even in young healthy adults) that can be revealed by [18F]-dopa PET studies. Substantia nigra hyperechogenicity is related to a higher tissue iron level, which is known to enhance the cells' generation of reactive oxygen specimens. Therefore, we hypothesize that transcranial sonography may identify a susceptibility marker for the development of nigral injury that can be detected early in life, prior to the onset of Parkinson disease.

Loss of heterozygosity on chromosome 22 in human ependymomas

Ependymomas are glial tumors of the brain and spinal cord. The most frequent genetic change in sporadic ependymomas is monosomy 22, suggesting the presence of an ependymoma tumor suppressor gene on chromosome 22. Thirty-three pairs of matched normal and tumor specimens from ependymoma patients were genotyped using 12 polymorphic microsatellite markers spanning the long arm of chromosome 22. Allelic deletion was found in 12 of 33 tumors (36.4%). Eight tumors showed partial deletions and 4 tumors exhibited loss of the entire arm of 22q. We identified two common regions of deletion: one at 22q11.21-12.2 flanked by markers D22S420 and D22S300, and a second candidate region at 22q13.1-13.3 between D22S274 and D22S1149. The size of each region was 21.1 and 2.4 cM, respectively. Thus, our results suggest that one or more tumor suppressor genes associated with ependymoma may be present on chromosome 22. Comparison of these results with clinicopathological data indicate that allelic losses on 22q tend to occur more frequently in intracranial anaplastic ependymomas in children and intraspinal ependymomas in adults.

TP53 gene mutations, nuclear p53 accumulation, expression of Waf/p21, Bcl-2, and CD95 (APO-1/Fas) proteins are not prognostic factors in de novo glioblastoma multiforme

Glioblastoma multiforme (WHO grade IV; GBM) is the most common primary brain tumor with a median survival of less than one year despite multimodal treatment regimens. However, a small subgroup of GBM patients has a better clinical outcome, with a small number of patients surviving several years. Apoptosis, a genetically determined program of cell suicide, may be induced as a consequence of critical DNA damage. However, due to defects in the signaling pathways, cancer cells may escape apoptosis, despite carrying irreversible DNA damage. In the present study, we have analyzed tumors of two age-matched, equally treated groups of GBM patients with different postoperative time to tumor progression (TTP), defined as 'short-term' for TTP of less than 6 months (n = 54), and 'long-term' for TTP of more than 12 months (n = 39) for alterations in apoptosis regulatory pathways: Mutations of the TP53 tumor suppressor gene and/or nuclear accumulation of its gene product p53, expression of Waf/p21, CD95 (Apo1/Fas), and Bcl-2. TP53 mutations were found in 12 out of 54 (22%) GBMs of short-term survivors and 8 out of 35 (23%) tumors of long-term survivors; the respective numbers for nuclear p53 protein accumulation were 12/53 (23%) and 10/37 (27%). Waf1/p21 expression was found in 13/53 (25%) tumors of short-term survivors and 9/35 (26%) GBMs of long-term survivors. The respective numbers for Bcl-2 expression were 25/42 (60%) and 22/36 (61%) and for CD95 (Apo1/Fas) expression 20/49 (41%) and 14/36 (39%) GBMs. The percentage of alterations in genes/proteins involved in the apoptotic pathway investigated here was virtually identical in the two groups of clinically different GBM patients. Thus, our data imply that none of these alterations investigated per se has a strong impact on the overall survival of GBM patients.

Increased microglia proliferation separates pilocytic astrocytomas from diffuse astrocytomas: a double labeling study

It is not known how many non-tumorous cells in gliomas contribute to the proliferation rate. We investigated the proliferative activity of microglia in an immunohistochemical double-labeling study of pilocytic astrocytomas and astrocytomas WHO grade II-IV using the antibodies MIB-1 (Ki67) as proliferation-marker and Ki-M1P (CD68) as microglia marker. We found the highest indices of proliferating microglia in pilocytic astrocytomas with an average rate of 32% (+/- 6.8) of all proliferating cells. In contrast, the proliferation indices of microglia were lowest in fibrillary astrocytomas with 8.6% (+/- 2.5) of all proliferating cells. In anaplastic astrocytomas and glioblastomas the percentage of proliferating microglia showed a slight increase to 8.8% (+/- 3.6) and 13.4% (+/- 8.7), respectively. We conclude that microglial cells in astrocytic brain tumors proliferate and show different proliferative activities at different grades of malignancy with the highest rates of proliferating microglia especially in pilocytic astrocytomas. Thus, the proliferation rate does not solely reflect the proliferation of tumor cells, but also of non-tumorous cells. This should be considered in particular when proliferation rates are used as a criterion for prognosis and grading of pilocytic astrocytomas.

Long-term survival of glioblastoma multiforme: importance of histopathological reevaluation

The overall prognosis for patients with glioblastoma multiforme is extremely poor. However, a small proportion of patients enjoy prolonged survival. This study investigated retrospectively the extent to which erroneous histopathological classification may contribute to long-term survival of patients initially diagnosed with "glioblastoma multiforme." We compared two age- and gender-matched patient groups with different postoperative time to tumor progression (TTP), defined as "short-term" for TTP of less than 6 months (n = 54), and "long-term" for TTP of more than 12 months (n = 52). Histological specimens of the corresponding tumors, all primarily diagnosed as glioblastoma multiforme, were reevaluated according to the current World Health Organization (WHO) classification of central nervous system tumors, with the investigators being blinded to clinical outcome. Among the tumors from short-term TTP patients, one tumor (2%) was reclassified as anaplastic oligoastrocytoma (WHO grade III) while the remaining 53 were confirmed as glioblastoma multiforme. In contrast, 13 tumors (25%) from the long-term TTP patients were reclassified, mostly as anaplastic oligodendroglioma (WHO grade III; n = 7) or anaplastic oligoastrocytoma (WHO grade III, n = 2), respectively. In addition, three were reclassified as anaplastic astrocytoma (WHO grade III), and one was identified as anaplastic pilocytic astrocytoma (WHO grade III). Our data indicate that a sizable proportion of glioblastoma patients with long-term survival actually carry malignant gliomas with oligodendroglial features. The correct histopathological recognition of these tumors has not only prognostic but also therapeutic implications, since oligodendroglial tumors are more likely to respond favorably to chemotherapy.

[Are morphologic changes in skeletal muscles of patients with malignant hyperthermia diagnostically useful?]

Malignant Hyperthermia (MH) represents a functional myopathy triggered by volatile anesthetics and depolarizing muscle relaxants, and leading to metabolic disturbances of intracellular Calcium homeostasis. Central-Core-like-structures (CCLS) were recently described as central defects in enzyme-histochemical stains and well correlated to the autosomal-dominant MH-predisposition. We studied the correlation of a MH-predisposition with specific myopathological signs. Skeletal muscles of suspected MH-individuals were histochemically stained by SDH-, NADH-, COX-, Gomori-Trichrome-, ATPase-, Acid Phosphatase-, Oil-red O- und PAS-stain und evaluated without knowing MH-diagnosis by the in-vitro-contracture test. Out of 118 patients (30% MHS ["susceptible"], 63% MHN [normal], 7% MHE ["equivocal"]) 19% revealed pathological findings corresponding to CCLS. 45% of these findings were associated with MHS/MHE. With HE-staining internal nuclei were not specific, but increased with the probability of MHS/MHE from 24% to 80%. Central Cores were correlated in 100% with MHS/MHE (4 out of 118 patients). CCLS were found with about similar frequency in skeletal muscle of MHS/MHE and MHN individuals. Internal nuclei were, however, not specifically, associated with MHS. In contrast, Central Cores correlated significantly with MHS/MHE diagnosis. In conclusion, histopathological findings in skeletal muscle seem to be a reliable marker for MH-predisposition only with Central Cores.

Microglial/macrophage expression of interleukin 10 in human glioblastomas

Interleukin 10 (IL-10) expression has been found to be correlated with the extent of malignancy in gliomas. In vitro, IL-10 increases proliferation and migratory capacity in human glioma cell lines. In this study, we localized the site of IL-10 synthesis in gliomas to cells of microglial origin. Biopsy specimens from 11 patients with malignant glioma were processed on native tissues and at early cell culture passages (0-4). IL-10 mRNA was analyzed by RT-PCR and in situ hybridization. Protein was quantitatively assessed by ELISA in cell culture supernatants, and cells expressing IL-10 were determined by a combination of immunohistochemistry for CD68 (specific for microglia/macrophage lineage) and IL-10 in situ hybridization. IL-10 mRNA decreased from passage 0 to 4 in all samples and was undetectable beyond passage 5. Such downregulation of mRNA leads to a steep decrease of IL-10 protein in culture supernatants (below detection level, 0.05 ng/ml, beyond passage 1). The combination of in situ hybridization for IL-10 and CD68 immunostaining revealed that only cells of the microglia/macrophage lineage produced IL-10 mRNA. Our results identify microglia/macrophage cells as the major source of IL-10 expression in gliomas which decreases markedly during early passages of primary cultures of human gliomas due to a progressive reduction of microglia/macrophages present.

Primary intracerebral Hodgkin's disease: report of a case with Epstein-Barr virus association and review of the literature

A case of primary intracerebral Hodgkin's disease (HD) without dural attachment in a 54-year-old immunocompetent patient is described. The infiltrate was located superficially in the occipital lobe and corresponded to the histologic type of nodular sclerosis. A typical immunohistochemical profile (membrane and cytoplasmic staining with dotlike Golgi enhancement of CD30, moderate cytoplasmic staining of CD15 in the Golgi area, membrane staining of CD20 of <10% of blastic cells, CD45RB negative) and in addition Epstein-Barr virus (EBV) latent membrane protein was detectable in Reed-Sternberg cells. Staging revealed no other organ sites of involvement. After combined surgery, postoperative radiotherapy, and chemotherapy, there are no signs of recurrence or systemic disease on follow-up for >1 year. To the authors' best knowledge, an association of EBV with primary central nervous system HD has not been demonstrated before.

Expression of matrix metalloproteinases in human glioma cell lines in the presence of IL-10

Matrix metalloproteinases have been implicated to play a vital role in glioma invasion as they degrade extracellular matrix to facilitate the subsequent migration of tumor cells into the surrounding brain tissue. The cytokine Interleukin-10 (IL-10) was detected recently in glial tumors in vivo. Expression of specific IL-10 mRNA as well as blood serum levels of IL-10 in glioma patients increased with malignancy suggesting a functional role of IL-10 in glioma progression. Moreover, glioma cell migration in vitro was enhanced in the presence of IL-10. We therefore investigated the expression of the matrix metalloproteinases (MMPs) stromelysin-1 (MMP-3), 72-kDa collagenase (MMP-2), 92-kDa collagenase (MMP-9), matrilysin (MMP-7) and the human macrophage metalloelastase (MMP-12). In addition, a possible relation between exposure of glioma cells to IL-10 and invasiveness of these cells due to MMP expression was analyzed. Experiments with Matrigel coated Boyden chambers revealed a pronounced dose dependent effect of IL-10 on glioma invasiveness. The synthetic MMP-inhibitor Marimastat markedly reduced cell invasion in the Boyden chambers confirming the significance of MMPs in the process of invasion. Subsequently, the expression level of MMPs and the serine protease uPA was investigated in 7 glioma cell lines (U373, GaMG, U251, GHE, SNB19, U138 and D54) by RT-PCR. In all but one cell line no enhancement of MMP expression by IL-10 was detected. Matrilysin in U373 cells was the only protease found to be upregulated in the presence of IL-10 dependent on cell density. The present data suggest that IL-10 related effects on the invasive properties of the cell lines are not directly mediated by an upregulation of matrix metalloproteinase expression.

Expression of matrix metalloproteinases in human glioma cell lines in the presence of IL-10

Matrix metalloproteinases have been implicated to play a vital role in glioma invasion as they degrade extracellular matrix to facilitate the subsequent migration of tumor cells into the surrounding brain tissue. The cytokine Interleukin-10 (IL-10) was detected recently in glial tumors in vivo. Expression of specific IL-10 mRNA as well as blood serum levels of IL-10 in glioma patients increased with malignancy suggesting a functional role of IL-10 in glioma progression. Moreover, glioma cell migration in vitro was enhanced in the presence of IL-10. We therefore investigated the expression of the matrix metalloproteinases (MMPs) stromelysin-1 (MMP-3), 72-kDa collagenase (MMP-2), 92-kDa collagenase (MMP-9), matrilysin (MMP-7) and the human macrophage metalloelastase (MMP-12). In addition, a possible relation between exposure of glioma cells to IL-10 and invasiveness of these cells due to MMP expression was analyzed. Experiments with Matrigel coated Boyden chambers revealed a pronounced dose dependent effect of IL-10 on glioma invasiveness. The synthetic MMP-inhibitor Marimastat markedly reduced cell invasion in the Boyden chambers confirming the significance of MMPs in the process of invasion. Subsequently, the expression level of MMPs and the serine protease uPA was investigated in 7 glioma cell lines (U373, GaMG, U251, GHE, SNB19, U138 and D54) by RT-PCR. In all but one cell line no enhancement of MMP expression by IL-10 was detected. Matrilysin in U373 cells was the only protease found to be upregulated in the presence of IL-10 dependent on cell density. The present data suggest that IL-10 related effects on the invasive properties of the cell lines are not directly mediated by an upregulation of matrix metalloproteinase expression.

[Dissections of the basilar artery]

PURPOSE

To describe clinical, radiological and pathological-anatomical findings of basilar artery dissections.

METHODS

During a period of three years (1994-1996) we observed 4 patients with dissections of the basilar artery, proven by angiography. Angiograms, MRI (n = 2) and autopsy results (n = 1) of these patients were correlated with clinical symptoms and long-term follow-up.

RESULTS

In three patients the dissection was confined into the basilar artery. Three patients with vertebrobasilar ischaemia showed irregularities of the vessel wall on angiography, in one of these patients autopsy revealed a haematoma within the vessel wall, located between intima and media. One patient complaining of relapsing headaches had a posttraumatic basilar artery aneurysm.

CONCLUSION

Dissections of the basilar artery can be separated in two types. In case of subintimal dissection patients present with vertebrobasilar ischaemia, which in contrast to extracranial dissections usually occurs without temporal delay. A second type of patients presents with subarachnoid haemorrhage. The dissection is subadventitial and pierces through a thin adventitia into the subarachnoid space.

Favorable outcome of giant cell glioblastoma in a child. Report of an 11-year survival period

Giant cell glioblastomas are defined as glioblastomas with a marked predominance of bizarre, multinucleated giant cells. They represent about 5% of all glioblastomas and can occur at any site of the central nervous system, but the temporal and frontal lobes are the sites of predilection. Overall, giant cell glioblastomas show a prolonged survival period compared with common glioblastoma multiforme, and survival periods of 7 and 9 years have been reported in adults. Here we report on a child aged 11 years at diagnosis, who has so far survived for 11 years since operation and adjunctive radio- and chemotherapy.