1,641 research outputs found

    Genes and pathways driving glioblastomas in humans and murine disease models

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    Human malignant gliomas arise from neural progenitor cells and/or dedifferentiated astrocytes. By now, they are genetically so well characterized that several murine glioma models have emerged that faithfully reiterate the typical histological features of the disease. In experimental animals, only one or two elements of the growth factor/Ras, PI3K/PTEN/PKB, p53/ARF/HDM2, and p16/Rb/cyclinD/CDK4 pathways are targeted. In human gliomas, many additional genes and pathways are targeted due to a most severe mutator phenotype that leads to the accumulation of countless epigenetic and genetic alterations. Changes that convey a growth advantage are selected for, leading to overgrowth of precursor cell populations with increasingly malignant tumor cell clones. While murine models represent a powerful tool for elucidating the role of genetic pathways, mechanisms of response and resistance to new therapeutic agents might be fundamentally different due to the high degree of genomic instability in the human disease. In fact, little is known about the molecular causes of genomic instability involved in gliomas, except for the rare Turcot's syndrome, O6-methylguanine-DNA methyltransferase, and the apurinic/apyrimidinic endonuclease Ape-1. Novel approaches that selectively exploit fundamental metabolic differences between tumor and normal cells have to consider these fundamental differences between human disease and presently available, highly sophisticated animal model

    Intradural spinal metastasis of renal cell cancer. Report of a case and review of 26 published cases

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    Metastatic disease in the intradural compartment of the spine is a rare manifestation of cancer. We report the case of an 82-year-old patient with an intradural, extramedullary metastasis of renal cell carcinoma in the cervical spine. A literature search for intradural spinal metastases of renal cell carcinoma yielded a total of 26 further cases. 18 patients had sporadic renal cell carcinoma, and 9 patients had von Hippel-Lindau disease (VHL) in which the metastases of the renal cell carcinoma were embedded within spinal haemangioblastomas. Patients presented with paresis, back pain, altered sensation or, less frequently, bladder dysfunction. Intradural spinal metastases were diagnosed at an earlier age in VHL patients than in sporadic cases (mean 43 ± 5years vs. 60 ± 14.5years). The metastasis was surgically removed in 81% of patients. Pain improved in all patients, paresis in 90%, hypaesthesia in 38% and bladder dysfunction in 50%. Death occured as a result of systemic cancer progression. 93% of patients in the sporadic renal cell cancer group died within 1.5years, whereas two thirds of the VHL patients were alive after 2year

    Characteristics and Treatment Outcome of Cerebrospinal Fluid Shunt-Associated Infections in Adults: A Retrospective Analysis over an 11-Year Period

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    Background. Data on infections associated with cerebrospinal fluid (CSF) shunts among adults are limited. Therefore, we performed a retrospective study of shunt-associated infections in adults. Methods. Patients aged ⩾12 years with infections associated with CSF shunts and admitted to our institution (University Hospital Basel, Basel, Switzerland) from January 1996 through December 2006 were included retrospectively. Hospital charts were reviewed, and follow-up was performed by assessment of later hospitalizations and telephone contact with patients, their families, and general practitioners. Results. Seventy-eight episodes of infection associated with ventriculoperitoneal shunt (65 episodes), ventriculoatrial shunt (7), lumboperitoneal shunt (5), and central nervous system reservoir (1) were included. Median patient age was 50 years (range, 12-80 years); 49 (63%) of the patients were men. Most infections (48 [62%]) manifested within 1 month after shunt surgery. Fever was present in 61 episodes (78%), neck stiffness was present in 35 (45%), and local signs of infection were present in 38 (49%). In CSF, leukocyte count was >5×106 cells/L in 80% of episodes, and lactate level was >1.9 mmol/L in 81% of episodes. Leukocyte counts were significantly higher in CSF obtained by use of lumbar puncture (median leukocyte count, 573×106 cells/L; P=.001) and valve puncture (median leukocyte count, 484×106 cells/L; P=.016) than in ventricular CSF (median leukocyte count, 8.5×106 cells/L). Overall, results of CSF cultures were positive in 66% of episodes (48 of 73 episodes for which CSF was collected), and microorganisms were isolated more often from valve puncture CSF specimens (91% of specimens) and ventricular CSF specimens (70%) than from lumbar CSF specimens (45%). The most prevalent organisms were coagulase-negative staphylococci (found in 37% of specimens), Staphylococcus aureus (18%), and Propionibacterium acnes (9%). A surgical procedure was performed to treat infection in 63 (81% of the episodes) (shunt removal in 37 episodes and shunt replacement in 26). The shunt was retained without surgery for 15 episodes (19% of episodes). Median duration of patient follow-up was 4.6 years (range, 0.1-11.1 years), with favorable treatment outcome in 75 (96%) of 78 cases. One of the 63 patients who underwent surgical treatment of shunt-associated infection experienced infection relapse; of the 15 patients who received treatment with antibiotics alone, 1 experienced infection relapse and 1 died. The 2 relapses involved rifampin-resistant coagulase-negative staphylococci. Conclusions. Shunt-associated infections among adults often present with nonspecific clinical signs, and affected patients can have normal CSF leukocyte counts and lactate levels; therefore, a high index of suspicion and improved methods are required for diagnosing shunt-associated infectio

    Neoadjuvant targeting of glioblastoma multiforme with radiolabeled DOTAGA-substance P—results from a phase I study

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    Complete surgical resection beyond tumor margins cannot be achieved in glioblastoma multiforme (GBM) because of infiltrative nature. In several cancers, neoadjuvant treatment has been implemented to reduce the risk of tumor cell spreading during resection. In GBM, the objective of a neoadjuvant approach is reduction of tumor cells within the main tumor mass and beyond in the infiltration zone. Such an approach can only be performed if elevated intracranial pressure can be medically controlled. In a previous study with recurrent gliomas, we showed that local intratumoral injection of radiolabeled DOTAGA-substance P substantially inhibited further growth and led to radionecrotic transformation of the tumor (CCR 2006). We have now examined this modality as neoadjuvant treatment for GBM, primarily assessing feasibility, toxicity, the extent of resection, and functional outcome. After diagnosis of GBM, 17 patients were included in a prospective phase I study. Repetitive intratumoral injections of radiolabeled DOTAGA-substance P were performed, followed by surgical resection. Chemical synthesis, radiolabeling, and local injection of the peptidic vector [90Yttrium]-DOTAGA-substance P were described previously. Neoadjuvant injection of [90Y]-DOTAGA-substance P was feasible without decompensation of intracranial pressure. Prolonged application of corticosteroids was identified as the main risk factor for side effects. Fifteen patients stabilized or improved their functional status. The mean extent of resection in subsequent surgery was 96%. Neoadjuvant therapy of GBM using locally injected radiolabeled DOTAGA-substance P was feasible and of low toxicity. The high extent of resection and concomitant irradiation of tumor cells in the infiltration zone may be prognostically relevan

    Long-Term Tumor Control Following Targeted Alpha Therapy (TAT) of Low-Grade Gliomas (LGGs): A New Treatment Paradigm?

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    The median survival time has been reported to vary between 5 and 8 years in low-grade (WHO grade 2) astrocytoma, and between 10 and 15 years for grade 2 oligodendroglioma. Targeted alpha therapy (TAT), using the modified peptide vector [213Bi]Bi/[225Ac]Ac-DOTA-substance P, has been developed to treat glioblastoma (GBM), a prevalent malignant brain tumor. In order to assess the risk of late neurotoxicity, assuming that reduced tumor cell proliferation and invasion should directly translate into good responses in low-grade gliomas (LGGs), a limited number of patients with diffuse invasive astrocytoma (n = 8) and oligodendroglioma (n = 3) were offered TAT. In two oligodendroglioma patients, TAT was applied as a second-line treatment for tumor progression, 10 years after targeted beta therapy using [90Y]Y-DOTA-substance P. The radiopharmaceutical was locally injected directly into the tumor via a stereotactic insertion of a capsule-catheter system. The activity used for radiolabeling was 2-2.5 GBq of Bismuth-213 and 17 to 35 MBq of Actinium-225, mostly applied in a single fraction. The recurrence-free survival times were in the range of 2 to 16 years (median 11 years) in low-grade astrocytoma (n = 8), in which TAT was administered following a biopsy or tumor debulking. Regarding oligodendroglioma, the recurrence-free survival time was 24 years in the first case treated, and 4 and 5 years in the two second-line cases. In conclusion, TAT leads to long-term tumor control in the majority of patients with LGG, and recurrence has so far not manifested in patients with low-grade (grade 2) astrocytomas who received TAT as a first-line therapy. We conclude that targeted alpha therapy has the potential to become a new treatment paradigm in LGG

    Individual voxelwise dosimetry of targeted 90Y-labelled substance P radiotherapy for malignant gliomas

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    Purpose: Substance P is the main ligand of neurokinin type 1 (NK-1) receptors, which are consistently overexpressed in malignant gliomas. The peptidic vector 111In/90Y-DOTAGA-substance P binds to these receptors and can be used for local treatment of brain tumours. Dosimetry for this interstitial brachytherapy has mainly been done using geometrical models; however, they often do not faithfully reproduce the in vivo biodistribution of radiopharmaceuticals, which is indispensable to correlate the deposited energy with clinical response. The aim of this study was to establish a reproducible dosimetry protocol for intratumoural radiopeptide therapy. Methods: For test and therapeutic injections, 2MBq of 111In-substance P and 370-3,330MBq of 90Y-substance P, respectively, were applied in 12 patients with malignant gliomas. Over a period of 24h, serial SPECT scans were performed on a dual-head SPECT camera. The scans were acquired in a double-energy window technique together with 99mTc-ECD in order to co-register the dose distributions with a separately acquired, contrast-enhanced CT scan. Quantitative voxelwise dose distribution maps (in Gy/GBq) were computed from these data using a mono-exponential decay approach. Pre- and post-therapeutic values were compared. Results: Agreement between pre- and post-therapeutic dosimetry was very good and delivered absolute dose values in Gy per injected GBq. In all patients, the pretherapeutic test injection together with the CT overlay technique could predict the precise localisation of dose deposition in an anatomical context. Conclusion: This protocol allows a precise pretherapeutic computation of the expected three-dimensional dose distribution and is clearly superior to the previously used dosimetry based on planar scintigraphic images. It has become an indispensable tool for planning intratumoural radiopeptide therapy in glioma patient

    A systematic review and critical analysis of cost-effectiveness studies for coronary artery disease treatment [version 2; referees: 2 approved]

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    Background: Cardiovascular disease remains the primary cause of death among Australians, despite dramatic improvements in overall cardiovascular health since the 1980s. Treating cardiovascular disease continues to place a significant economic strain on the Australian health care system, with direct healthcare costs exceeding those of any other disease. Coronary artery disease accounts for nearly one third of these costs and spending continues to rise. A range of treatments is available for coronary artery disease yet evidence of cost-effectiveness is missing, particularly for the Australian context. Cost-effectiveness evidence can signal waste and inefficiency and so is essential for an efficient allocation of healthcare resources. Methods: We used systematic review methods to search the literature across several electronic databases for economic evaluations of treatments for stable coronary artery disease.  We critically appraised the literature found in searches, both against the CHEERS statement for quality reporting of economic evaluations and in terms of its usefulness for policy and decision-makers. Results: We retrieved a total of 308 references, 229 once duplicates were removed. Of these, 26 were excluded as they were not full papers (letters, editorials etc.), 55 were review papers, 50 were not cost-effectiveness analyses and 93 related to a highly specific patient sub-group or did not consider all treatment options.  This left five papers to be reviewed in full. Conclusions: The current cost-effectiveness evidence does not support the increased use of PCI that has been seen in Australia and internationally. Due to problems with accessibility, clarity and relevance to policy and decision-makers, some otherwise very scientifically rigorous analyses have failed to generate any policy changes

    Clinical Use and Effectiveness of Lipid Lowering Therapies in Diabetes Mellitus—An Observational Study from the Swedish National Diabetes Register

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    OBJECTIVES: To describe the use and evaluate the effectiveness of different lipid lowering therapies in unselected patients with type 1 and type 2 diabetes in clinical practice. DESIGN: Observational population-based study using the personal identification number to link information from the National Diabetes Register, the Prescribed Drug Register and the Patient register in Sweden. All patients in the NDR aged 18-75 years with diabetes more than one year were eligible, but only patients starting any lipid lowering treatment with at least three prescriptions 1 July 2006-30 June 2007 were included (n = 37,182). The mean blood lipid levels in 2008 and reductions in LDL cholesterol were examined. RESULTS: Blood lipid levels were similar in patients treated with simvastatin, atorvastatin and rosuvastatin, showing similar lipid lowering effect as currently used. Users of pravastatin, fluvastatin, ezetimib and fibrate more seldom reach treatment goals. Moderate daily doses of the statins were used, with 76% of simvastatin users taking 20 mg or less, 48% of atorvastatin users taking 10 mg, 55% of pravastatin users taking 20 mg, and 76% of rosuvastatin users taking 5 or 10 mg. CONCLUSIONS: This observational study shows that the LDL-C levels in patients taking simvastatin, atorvastatin or rosuvastatin are very similar as currently used, as well as their LDL-C lowering abilities. There is potential to intensify lipid lowering treatment to reduce the remaining high residual risk and achieve better fulfilment of treatment goals, since the commonly used doses are only low to moderate

    Loss of NOTCH2 Positively Predicts Survival in Subgroups of Human Glial Brain Tumors

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    The structural complexity of chromosome 1p centromeric region has been an obstacle for fine mapping of tumor suppressor genes in this area. Loss of heterozygosity (LOH) on chromosome 1p is associated with the longer survival of oligodendroglioma (OD) patients. To test the clinical relevance of 1p loss in glioblastomas (GBM) patients and identifiy the underlying tumor suppressor locus, we constructed a somatic deletion map on chromosome 1p in 26 OG and 118 GBM. Deletion hotspots at 4 microsatellite markers located at 1p36.3, 1p36.1, 1p22 and 1p11 defined 10 distinct haplotypes that were related to patient survival. We found that loss of 1p centromeric marker D1S2696 within NOTCH2 intron 12 was associated with favorable prognosis in OD (P = 0.0007) as well as in GBM (P = 0.0175), while 19q loss, concomitant with 1p LOH in OD, had no influence on GBM survival (P = 0.918). Assessment of the intra-chromosomal ratio between NOTCH2 and its 1q21 pericentric duplication N2N (N2/N2N-test) allowed delineation of a consistent centromeric breakpoint in OD that also contained a minimally lost area in GBM. OD and GBM showed distinct deletion patterns that converged to the NOTCH2 gene in both glioma subtypes. Moreover, the N2/N2N-test disclosed homozygous deletions of NOTCH2 in primary OD. The N2/N2N test distinguished OD from GBM with a specificity of 100% and a sensitivity of 97%. Combined assessment of NOTCH2 genetic markers D1S2696 and N2/N2N predicted 24-month survival with an accuracy (0.925) that is equivalent to histological classification combined with the D1S2696 status (0.954) and higher than current genetic evaluation by 1p/19q LOH (0.762). Our data propose NOTCH2 as a powerful new molecular test to detect prognostically favorable gliomas

    Loss of heterozygosity of TRIM3 in malignant gliomas

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    <p>Abstract</p> <p>Background</p> <p>Malignant gliomas are frequent primary brain tumors associated with poor prognosis and very limited response to conventional chemo- and radio-therapies. Besides sharing common growth features with other types of solid tumors, gliomas are highly invasive into adjacent brain tissue, which renders them particularly aggressive and their surgical resection inefficient. Therefore, insights into glioma formation are of fundamental interest in order to provide novel molecular targets for diagnostic purposes and potential anti-cancer drugs. Human <it>Tripartite motif protein 3 </it>(<it>TRIM3</it>) encodes a structural homolog of <it>Drosophila brain tumor </it>(<it>brat</it>) implicated in progenitor cell proliferation control and cancer stem cell suppression. <it>TRIM3 </it>is located within the loss of allelic heterozygosity (LOH) hotspot of chromosome segment 11p15.5, indicating a potential role in tumor suppression. ...</p> <p>Methods</p> <p>Here we analyze 70 primary human gliomas of all types and grades and report somatic deletion mapping as well as single nucleotide polymorphism analysis together with quantitative real-time PCR of chromosome segment 11p15.5.</p> <p>Results</p> <p>Our analysis identifies LOH in 17 cases (24%) of primary human glioma which defines a common 130 kb-wide interval within the <it>TRIM3 </it>locus as a minimal area of loss. We further detect altered genomic dosage of <it>TRIM3 </it>in two glioma cases with LOH at 11p15.5, indicating homozygous deletions of <it>TRIM3</it>.</p> <p>Conclusion</p> <p>Loss of heterozygosity of chromosome segment 11p15.5 in malignant gliomas suggests <it>TRIM3 </it>as a candidate brain tumor suppressor gene.</p
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