Search

Molecular imaging studies have recently found inter- and intratumoral heterogeneity in World Health Organization (WHO) grade II gliomas. A correlative analysis with tumor histology, however, is still lacking. For elucidation we conducted the current prospective study. Fifty-five adult patients with an MRI-based suspicion of a WHO grade II glioma were included. [F-18]Fluoroethyltyrosine ((18)FET) uptake kinetic studies were combined with frame-based stereotactic localization techniques and used as a guide for stepwise (1-mm steps) histopathological evaluation throughout the tumor space. In tumors with heterogeneous PET findings, the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and expression of mutated protein isocitrate dehydrogenase variant R132H (IDH1) were determined inside and outside of hot spot volumes. Metabolic imaging revealed 3 subgroups: the homogeneous WHO grade II glioma group (30 patients), the homogeneous malignant glioma group (10 patients), and the heterogeneous group exhibiting both low- and high-grade characteristics at different sites (15 patients). Stepwise evaluation of 373 biopsy samples indicated a strong correlation with analyses of uptake kinetics (p < 0.0001). A homogeneous pattern of uptake kinetics was linked to homogeneous histopathological findings, whereas a heterogeneous pattern was associated with histopathological heterogeneity; hot spots exhibiting malignant glioma characteristics covered 4-44% of the entire tumor volumes. Both MGMT and IDH1 status were identical at different tumor sites and not influenced by heterogeneity. Maps of (18)FET uptake kinetics strongly correlated with histopathology in suspected grade II gliomas. Anaplastic foci can be accurately identified, and this finding has implications for prognostic evaluation and treatment planning.

Background: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression., Methodology/principal Findings: ADULT PATIENTS WITH A HISTOLOGICALLY PROVEN MALIGNANT ASTROCYTOMA (GLIOBLASTOMA: N = 53, anaplastic astrocytoma: N = 10) were included. MGMT promoter methylation was determined by methylation-specific PCR (MSP) and sequencing analysis. Expression of MGMT and DNMTs mRNA were analysed by real-time qPCR. Prognostic factors were obtained from proportional hazards models. Correlation between MGMT mRNA expression and MGMT methylation status was validated using data from the Cancer Genome Atlas (TCGA) database (N = 229 glioblastomas). Low MGMT mRNA expression was strongly predictive for prolonged time to progression, treatment response, and length of survival in univariate and multivariate models (p<0.0001); the degree of MGMT mRNA expression was highly correlated with the MGMT promoter methylation status (p<0.0001); however, discordant findings were seen in 12 glioblastoma patients: Patients with methylated tumors with high MGMT mRNA expression (N = 6) did significantly worse than those with low transcriptional activity (p<0.01). Conversely, unmethylated tumors with low MGMT mRNA expression (N = 6) did better than their counterparts. A nearly identical frequency of concordant and discordant findings was obtained by analyzing the TCGA database (p<0.0001). Expression of DNMT1 and DNMT3b was strongly upregulated in tumor tissue, but not correlated with MGMT promoter methylation and MGMT mRNA expression., Conclusions/significance: MGMT mRNA expression plays a direct role for mediating tumor sensitivity to alkylating agents. Discordant findings indicate methylation-independent pathways of MGMT expression regulation. DNMT1 and DNMT3b are likely to be involved in CGI methylation. However, their exact role yet has to be defined.

Purpose: To preoperatively detect, by using diffusion-tensor imaging coregistered with anatomic magnetic resonance (MR) imaging, suspected microstructural tissue changes of the trigeminal nerves in patients with trigeminal neuralgia (TN) resulting from neurovascular compression., Materials and Methods: The study was approved by the institutional review board, and written informed consent was obtained from all patients. Twenty patients (mean age, 51.3 years) with TN and evidence of neurovascular contact were examined with use of a 3.0-T MR unit combined with an eight-channel head coil before undergoing surgical decompression. A single-shot diffusion-tensor echo-planar sequence was used along 15 different diffusion directions, with a b value of 1000 sec/mm(2) and a section thickness of 2 mm. For anatomic correlation, 0.6-mm isotropic three-dimensional fast imaging employing steady-state images were acquired for coregistration with the functional diffusion-tensor maps. After region of interest placement, mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated for each nerve by using the paired-sample two-tailed t test (with P < .005 indicating significance) and compared with surgical findings., Results: FA was significantly lower (P = .004) on the trigeminal neuralgia-affected side (mean FA, 0.203) than on the contralateral side (mean FA, 0.239). ADCs were nearly identical between the normal and TN-affected nerve tissues., Conclusion: These findings suggest that diffusion-tensor imaging enables the identification and quantification of anisotropic changes between normal nerve tissue and TN-affected trigeminal nerves. Coregistration of anatomic three-dimensional fast imaging employing steady-state imaging and diffusion-tensor imaging facilitates excellent delineation of the cisternal segments of the trigeminal nerves., (© RSNA, 2010.)

Background: A substantial proportion of therapists experience the loss of a patient to suicide at some point during their professional life., Aims: To assess (1) the impact of a patient's suicide on therapists distress and well-being over time, (2) which factors contribute to the reaction, and (3) which subgroup might need special interventions in the aftermath of suicide., Methods: A 63-item questionnaire was sent to all 185 Psychiatric Clinics at General Hospitals in Germany. The emotional reaction of therapists to patient's suicide was measured immediately, after 2 weeks, and after 6 months., Results: Three out of ten therapists suffer from severe distress after a patients' suicide. The item "overall distress" immediately after the suicide predicts emotional reactions and changes in behavior. The emotional responses immediately after the suicide explained 43.5% of the variance of total distress in a regression analysis., Limitations: The retrospective nature of the study is its primary limitation., Conclusions: Our data suggest that identifying the severely distressed subgroup could be done using a visual analog scale for overall distress. As a consequence, more specific and intensified help could be provided to these professionals.

A substantial proportion of therapists will at some point in their professional life experience the loss of a patient to suicide. Our aims were to assess how therapists react to patient's suicide over time and which factors contribute to the reaction. One third of the therapists, mostly women, suffer from severe distress. The impact is not different for therapists in institutional settings and therapists in private practice. The item "overall distress" immediately after the suicide predicts emotional reactions and changes in behavior. Our data suggest that identifying the severely distressed subgroup could be done using a visual analogue scale for overall distress. As a consequence, more specific and intensified help could be provided to these individuals.

Even though stereotactic brachytherapy has been used for treatment of complex located low-grade glioma for many years, its place within modern treatment concepts is still debated and only a few centers have gained experience with this complex treatment modality. The current article reviews selection criteria, treatment protocols, radiobiology, treatment effects, risk models and side effects of stereotactic brachytherapy. Potentially alternative techniques such as radiosurgery were also reviewed under consideration of radiobiological similarities and differences.

Phosphatidylethanol (PEth) is a direct ethanol metabolite, and has recently attracted attention as biomarker of ethanol intake. The aims of the current study are: (1) to characterize the normalization time of PEth in larger samples than previously conducted; (2) to elucidate potential gender differences; and (3) to report the correlation of PEth with other biomarkers and self-reported alcohol consumption. Fifty-seven alcohol-dependent patients (ICD 10 F 10.25; 9 females, 48 males) entering medical detoxification at three study sites were enrolled. The study sample was comprised of 48 males and 9 females, with mean age 43.5. Mean gamma glutamyl transpeptidase (GGT) was 209.61 U/l, average mean corpuscular volume (MCV) was 97.35 fl, mean carbohydrate deficient transferrin (%CDT) was 8.68, and mean total ethanol intake in the last 7 days was 1653 g. PEth was measured in heparinized whole blood with a high-pressure liquid chromatography method, while GGT, MCV and %CDT were measured using routine methods. PEth levels at day 1 of detoxification ranged between 0.63 and 26.95 micromol/l (6.22 mean, 4.70 median, SD 4.97). There were no false negatives at day 1. Sensitivities for the other biomarkers were 40.4% for MCV, 73.1% for GGT and 69.2% for %CDT, respectively. No gender differences were found for PEth levels at any time point. Our data suggest that PEth is (1) a suitable intermediate term marker of ethanol intake in both sexes; and (2) sensitivity is extraordinary high in alcohol dependent patients. The results add further evidence to the data that suggest that PEth has potential as a candidate for a sensitive and specific biomarker, which reflects longer-lasting intake of higher amounts of alcohol and seemingly has the above mentioned certain advantages over traditional biomarkers.

Background: Presence of CD133(+) cancer stem cells has been demonstrated within glioblastoma multiforme (GBM), the most malignant phenotype of gliomas (WHO grade IV). Since GBM frequently develops from low grade gliomas (WHO grade II) we assessed a possible qualitative or quantitative correlation of CD133(+) cells and glioma grade to get new insights in gliomagenesis., Results: The amount of CD133(+) cells within the bulk tumor mass, analyzed by immunostaining and Western blotting, showed a clear quantitative correlation with glioma grade (WHO degrees II, III and IV). Most of CD133(+) cells were arranged in clusters frequently associated to tumor vessels. Protein analysis revealed high cellular coexpression of CD133 with Musashi-I but not CD34 indicating a neural, i.e. local origin of these cells. In vitro, no differences in stem cell properties concerning self-renewal and multi-lineage differentiation have been found for CD133(+) cells isolated from gliomas of different grades., Conclusions: These findings indicate a solely quantitative correlation of glioma grade with the presence of neural CD133(+) cells within tumors supporting the concept of a CD133(+) stem cell dependent gliomagenesis., (Copyright 2008. Published by Elsevier Inc.)

We report a molecular stereotactic biopsy technique that combines histopathologic diagnosis with small sample size-adjusted molecular genetic analysis of low-grade gliomas that are ineligible for tumor resection. Loss of heterozygosity (LOH) of 1p/19q and TP53 mutations were analyzed in 1-mm tissue samples from 42 World Health Organization grade II gliomas (30 astrocytomas, 8 oligoastrocytomas, 4 oligodendrogliomas) using polymerase chain reaction-based microsatellite and sequence analysis. Alternating histological and molecular genetic evaluation within 1-mm steps at different sites within each tumor was performed to determine reproducibility of the results and the intratumoral distribution of the biomarkers. Multiple serial biopsies (range, 2-5 per tumor) taken from distinct intratumoral areas revealed concordant molecular genetic findings and homogeneous distribution of both biomarkers throughout 41 tumors. Contamination by nonneoplastic tissue could be recognized by corresponding histological evaluation and resulted in discordant LOH findings in 1 tumor. The frequency of LOH 1p/19q and TP53 mutations was consistent with the literature; these genetic alterations were found to be mutually exclusive. There was no biopsy-related morbidity. We conclude that determination of the LOH 1p/19q and TP53 status using this molecular stereotactic biopsy technique is safe and reliable in cases of unresectable gliomas.

Background: Heavy alcohol consumption may accelerate the progression of hepatitis C (HCV)-related liver disease and/or limit efforts at antiviral treatment. As most of the patients in methadone maintenance treatment (MMT) suffer from hepatitis C infection, this study was conducted to identify the alcohol intake among these patients at a Swiss Psychiatric University Clinic by self-reports and direct ethanol metabolites as biomarkers of ethanol consumption., Patients and Methods: A convenience sample of 40 MMT patients (15 women, 25 men; median age 39 years) of the total 124 patients was asked and consented to participate in this study. This sample was not different in age, gender distribution, and rate of hepatitis C infection from the total sample. The Alcohol Use Disorders Identification Test (AUDIT) and self-reported ethanol intake during the previous 7 days were assessed. In addition, ethyl glucuronide (EtG) in urine, and fatty acid ethyl esters (FAEEs) and EtG in hair were determined using LC-MS/MS and gas chromatograph/mass spectrometer. The limit of quantitation for UEtG, HEtG, and FAEEs were 0.1 mg/l, 2.3 pg/mg, and 0.1 ng/mg, respectively., Results: Fourteen participants reported abstinence from alcohol for the previous 7 days. AUDIT scores were > or =8 in 15 male and >5 in 5 female participants. Direct ethanol metabolites were as follows (median, min, max, standard deviation): UEtG (19 positives; 9.91, 1.38 to 251, 62.39 mg/l); the values of HEtG were 17.65, 0 to 513, 105.62 pg/mg [in 2 cases no material, 8 abstinent (up to 7 pg/mg), 15 social drinkers (up to 50 g per day), and 15 excessive users (>50/60 g/d)]. For the 13 cases, where enough material for additional determination of HFAEEs was available, the values were 0.32, 0 to 1.32, 0.44 ng/mg. Among the 30 HEtG-positive participants, 20 had not reported the corresponding ethanol intake using question 1 (frequency) and 2 (quantity) of the AUDIT. Of the 14 participants reporting no alcohol intake during the previous 7 days, 4 were UEtG-positive. HEtG and AUDIT correlated significantly (r = 0.622, p < 0.0001), but this was not the case for UEtG and self-reported ethanol intake during the previous 7 days., Conclusion: (1) HEtG identified 20 cases of daily ethanol intake of more than 20 g, that would have been missed by the sole use of question 1 (frequency) and 2 (quantity) of the AUDIT. (2) Using the total score of the AUDIT, HEtG confirmed 10 more cases positive for alcohol intake. (3) Episodic heavy drinking is with 22.5% more frequent than in general population, and (4) of the 14 participants who reported no alcohol intake during the previous 7 days, 4 were UEtG positive. Improved detection of alcohol consumption, which is hazardous or harmful in the context of HCV and opiate dependence, would allow for earlier intervention in this population which is at particular risk of liver disease and fatal respiratory-depressed overdose. The combined use of self-reports and direct ethanol metabolites seems promising.

In malignant gliomas, the integrin adhesion receptors seem to play a key role for invasive growth and angiogenesis. However, there is still a controversy about the expression and the distribution of alpha(v)beta(3) integrin caused by malignancy. The aim of our study was to assess the extent and pattern of alpha(v)beta(3) integrin expression within primary glioblastomas (GBMs) compared with low-grade gliomas (LGGs). Tumor samples were immunostained for the detection of alpha(v)beta(3) integrin and quantified by an imaging software. The expression of alpha(v)beta(3) was found to be significantly higher in GBMs than in LGGs, whereby focal strong reactivity was restricted to GBMs only. Subsequent analysis revealed that not only endothelial cells but also, to a large extent, glial tumor cells contribute to the overall amount of alpha(v)beta(3) integrin in the tumors. To further analyze the integrin subunits, Western blots from histologic sections were performed, which demonstrated a significant difference in the expression of the beta(3) integrin subunit between GBMs and LGGs. The presented data lead to new insights in the pattern of alpha(v)beta(3) integrin in gliomas and are of relevance for the inhibition of alpha(v)beta(3) integrin with specific RGD peptides and interfering drugs to reduce angiogenesis and tumor growth.

Angiogenic processes are regulated by vascular endothelial growth factors (VEGFs) and their receptors VEGFR1 (Flt-1), 2 (Flk-1) and 3 (Flt-4). While VEGFR2 is thought to play a central role in tumor angiogenesis, anti-angiogenic therapies targeting VEGFR2 in glioma models can show escape phenomena with secondary onset of angiogenesis. The purpose of this study was to find explanations for these processes by searching for alternative pathways regulating glioma angiogenesis and reveal a correlation with tumor grade. Thus, VEGFR3, which is not expressed in normal brain, and its ligands VEGF-C and -D, were assessed in high grade (WHO degrees IV, glioblastomas, GBM) and low grade gliomas [WHO degrees II astrocytomas (AII)]. In all GBM, a strong protein expression of VEGFR3 was found on tumor endothelium, VEGF-C and -D expression was found on numerous cells in areas of high vascularization. On RNA level, a significant up-regulation of VEGFR3 was detected in GBM compared to AII and non-neoplastic brain. In AII, only very moderate VEGFR3, VEGF-C and -D expression was found on protein and RNA level indicating a correlation of VEGFR3 expression with tumor grade. VEGFR3 signal in both grades was found predominantly on endothelial cells, confirmed by VEGFR3 expression on isolated CD31 positive cells and the expression of various endothelial markers on VEGFR3-positive cells isolated from GBM. The demonstration of a complete angiogenic signaling system that is dependent on tumor grade may influence the traditional paradigm of glioma angiogenesis and may provide a basis for more effective anti-angiogenic treatment strategies.

Febrile seizures are the most common type of developmental seizures, affecting up to 5% of children. Experimental complex febrile seizures involving the immature rat hippocampus led to a persistent lowering of seizure threshold despite an upregulation of inhibition. Here we provide a mechanistic resolution to this paradox by showing that, in the hippocampus of rats that had febrile seizures, the long-lasting enhancement of the widely expressed intrinsic membrane conductance Ih converts the potentiated synaptic inhibition to hyperexcitability in a frequency-dependent manner. The altered gain of this molecular inhibition-excitation converter reveals a new mechanism for controlling the balance of excitation-inhibition in the limbic system. In addition, here we show for the first time that h-channels are modified in a human neurological disease paradigm.

The chondroitin sulphate proteoglycan brevican is one of the most abundant extracellular matrix molecules in the adult rat brain. It is primarily synthesized by astrocytes and is believed to influence astroglial motility during development and under certain pathological conditions. In order to study a potential role of brevican in the glial reaction after brain injury, its expression was analysed following entorhinal cortex lesion in rats (12 h, 1, 2, 4, 10, 14 and 28 days and 6 months post lesion). In situ hybridization and immunohistochemistry were employed to study brevican mRNA and protein, respectively, in the denervated outer molecular layer of the fascia dentata and at the lesion site. In both regions brevican mRNA was upregulated between 1 and 4 days post lesion. The combination of in situ hybridization with immunohistochemistry for glial fibrillary acidic protein demonstrated that many brevican mRNA-expressing cells are astrocytes. In the denervated zone of the fascia dentata, immunostaining for brevican was increased by 4 days, reached a maximum by 4 weeks and remained detectable up to 6 months post lesion. Electron microscopic immunocytochemistry showed that brevican is a component of the extracellular matrix compartment. At the lesion site a similar time course of brevican upregulation was observed. These data demonstrate that brevican is upregulated in areas of brain damage as well as in areas denervated by a lesion. They suggest a role of brevican in reactive gliosis and are compatible with the hypothesis that brevican is involved in the synaptic reorganization of denervated brain areas.

The chondroitin sulfate proteoglycan neurocan is a major component of brain extracellular matrix during development. Neurocan is primarily synthesized by neurons and has the ability to interact with cell adhesion molecules involved in the regulation of cell migration and axonal growth. Within the first weeks postnatally, neurocan expression is strongly downregulated. To test whether neurocan is reexpressed in areas of axonal growth (sprouting) after brain injury, the time course of neurocan expression was analyzed in the denervated fascia dentata of the rat after entorhinal cortex lesion (12 hr; 1, 2, 4, and 10 d; 2 and 4 weeks; and 6 months after lesion). In the denervated zone, immunohistochemistry revealed neurocan-positive astrocytes by 2 d after lesion and a diffuse labeling of the extracellular matrix at all later time points. Electron microscopy confirmed the deposition of neurocan in the extracellular matrix compartment. In situ hybridization demonstrated a strong upregulation of neurocan mRNA within the denervated outer molecular layer 1 and 4 d after lesion. The combination of in situ hybridization with immunohistochemistry for glial fibrillary acidic protein demonstrated that the neurocan mRNA-expressing cells are astrocytes. These data demonstrate that neurocan is reexpressed in the injured brain. In contrast to the situation during development, astrocytes, but not neurons, express neurocan and enrich the extracellular matrix with this molecule. Similar to the situation during development, neurocan is expressed in an area of active axon growth, and it is suggested that neurocan acts to maintain the boundaries of the denervated fascia dentata after entorhinal cortex lesion.