1,774 research outputs found

    Genes and pathways driving glioblastomas in humans and murine disease models

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

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

    Get PDF
    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

    Measurements of the pp → ZZ production cross section and the Z → 4ℓ branching fraction, and constraints on anomalous triple gauge couplings at √s = 13 TeV

    Get PDF
    Four-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*) -> 4l, where l = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 17.2 +/- 0.5 (stat) +/- 0.7 (syst) +/- 0.4 (theo) +/- 0.4 (lumi) pb, measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 4l) = 4.83(-0.22)(+0.23) (stat)(-0.29)(+0.32) (syst) +/- 0.08 (theo) +/- 0.12(lumi) x 10(-6) for events with a four-lepton invariant mass in the range 80 4GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ. couplings at 95% confidence level: -0.0012 < f(4)(Z) < 0.0010, -0.0010 < f(5)(Z) < 0.0013, -0.0012 < f(4)(gamma) < 0.0013, -0.0012 < f(5)(gamma) < 0.0013

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

    Get PDF
    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

    Get PDF
    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia
    corecore