1,720,991 research outputs found
D-Dimer Elevation and Paresis Predict Thromboembolic Events During Bevacizumab Therapy for Recurrent Malignant Glioma
No full textBackground: The major side-effects of bevacizumab in glioma treatment are venous thromboembolic events (VTE). We retrospectively evaluated factors potentially predictive of thromboembolic events. Patients and Methods: Bevacizumab, alone or in combination with chemotherapy was used as salvage therapy for recurrence in malignant glioma every two weeks. None but one patient received anticoagulants. Before each bevacizumab cycle differential blood cell count, kidney and liver parameters, D-dimers, neurological status, body-mass index, vital signs and signs of venous thrombosis were assessed. Results: Thirty-eight patients received 428 cycles of bevacizumab. In five patients (13%), six VTE were observed. These complications were preceded four weeks before the onset of symptoms by D-dimer elevation above 0.865 mg/l [p<0.0001; sensitivity=89% (95% confidence interval=83-93%); specificity=89% (95% CI=52-100%)]. An existing hemiparesis constituted a 27-fold risk elevation for thrombotic complication (p<0.0001, chi(2)-test). Conclusion: D-Dimer elevation or hemiparesis predict VTE under bevacizumab and chemotherapy, four weeks before the event becomes clinically apparent. Future investigations should determine if prophylactic anti-coagulants for patients at risk may reduce the risk of VTE
IDH1/2 mutations in WHO grade II astrocytomas associated with localization and seizure as the initial symptom
No full textAbstractIntroductionSeizures are the most common initial symptom in patients with low-grade glioma and their occurrence strongly depends on the tumor location. The majority of low-grade gliomas reveal mutations in the genes encoding isocitrate-dehydrogenase 1 (IDH1) or 2 (IDH2). These mutations are associated with metabolic changes that are potentially epileptogenic. We investigated the correlation between IDH1/2 mutations and tumor localization and seizure as the initial symptom.Materials and methodsThis retrospective study included patients with a diagnosis of WHO grade II astrocytoma and cortical infiltration and in whom initial symptoms were documented and biopsy tissue was available for IDH1/2 analysis. IDH1/2 mutation analysis was performed by direct sequencing or by immunohistochemistry with an antibody which detects mutated protein IDH1 R132H. Sequencing was carried out if immunohistochemistry was negative. IDH1/2 status was defined as mutated if either of these investigations were positive.ResultsSeventy-nine patients were included. IDH1 or IDH2 mutation was present in 63 (80%) patients who on average were younger than patients without IDH1/2 mutation (40 vs. 47 years, p=0.0331, t-test). IDH1/2 mutations were associated with frontal tumor location (p=0.0202). All 12 tumors in the insula revealed IDH1/2 mutations. Seizure as the initial symptom was recorded in 57 (72%) patients and was associated with IDH1 or IDH2 mutation by multivariate analysis (OR 22.563, p=0.0019).ConclusionIn WHO grade II astrocytomas, IDH1/2 mutations mostly occur in tumors infiltrating the frontal lobe. Seizure as the initial symptom is associated with IDH1 or IDH2 mutation
D-Dimer Elevation and Paresis Predict Thromboembolic Events During Bevacizumab Therapy for Recurrent Malignant Glioma
No full textBackground: The major side-effects of bevacizumab in glioma treatment are venous thromboembolic events (VTE). We retrospectively evaluated factors potentially predictive of thromboembolic events. Patients and Methods: Bevacizumab, alone or in combination with chemotherapy was used as salvage therapy for recurrence in malignant glioma every two weeks. None but one patient received anticoagulants. Before each bevacizumab cycle differential blood cell count, kidney and liver parameters, D-dimers, neurological status, body-mass index, vital signs and signs of venous thrombosis were assessed. Results: Thirty-eight patients received 428 cycles of bevacizumab. In five patients (13%), six VTE were observed. These complications were preceded four weeks before the onset of symptoms by D-dimer elevation above 0.865 mg/l [p<0.0001; sensitivity=89% (95% confidence interval=83-93%); specificity=89% (95% CI=52-100%)]. An existing hemiparesis constituted a 27-fold risk elevation for thrombotic complication (p<0.0001, chi(2)-test). Conclusion: D-Dimer elevation or hemiparesis predict VTE under bevacizumab and chemotherapy, four weeks before the event becomes clinically apparent. Future investigations should determine if prophylactic anti-coagulants for patients at risk may reduce the risk of VTE
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Clinical benefit from resection of recurrent glioblastomas: results of a multicenter study including 503 patients with recurrent glioblastomas undergoing surgical resection.
No full textBACKGROUND
While standards for the treatment of newly diagnosed glioblastomas exist, therapeutic regimens for tumor recurrence remain mostly individualized. The role of a surgical resection of recurrent glioblastomas remains largely unclear at present. This study aimed to assess the effect of repeated resection of recurrent glioblastomas on patient survival.
METHODS
In a multicenter retrospective-design study, patients with primary glioblastomas undergoing repeat resections for recurrent tumors were evaluated for factors affecting survival. Age, Karnofsky performance status (KPS), extent of resection (EOR), tumor location, and complications were assessed.
RESULTS
Five hundred and three patients (initially diagnosed between 2006 and 2010) undergoing resections for recurrent glioblastoma at 20 institutions were included in the study. The patients' median overall survival after initial diagnosis was 25.0 months and 11.9 months after first re-resection. The following parameters were found to influence survival significantly after first re-resection: preoperative and postoperative KPS, EOR of first re-resection, and chemotherapy after first re-resection. The rate of permanent new deficits after first re-resection was 8%.
CONCLUSION
The present study supports the view that surgical resections of recurrent glioblastomas may help to prolong patient survival at an acceptable complication rate
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Proteomics separates adult-type diffuse high-grade gliomas in metabolic subgroups independent of 1p/19q codeletion and across IDH mutational status
No full textHigh-grade adult-type diffuse gliomas are malignant neuroepithelial tumors with poor survival rates in combined chemoradiotherapy. The current WHO classification is based on IDH1/2 mutational and 1p/19q codeletion status. Glioma proteome alterations remain undercharacterized despite their promise for a better molecular patient stratification and therapeutic target identification. Here, we use mass spectrometry to characterize 42 formalin-fixed, paraffin-embedded (FFPE) samples from IDH-wild-type (IDHwt) gliomas, IDH-mutant (IDHmut) gliomas with and without 1p/19q codeletion, and non-neoplastic controls. Based on more than 5,500 quantified proteins and 5,000 phosphosites, gliomas separate by IDH1/2 mutational status but not by 1p/19q status. Instead, IDHmut gliomas split into two proteomic subtypes with widespread perturbations, including aerobic/anaerobic energy metabolism. Validations with three independent glioma proteome datasets confirm these subgroups and link the IDHmut subtypes to the established proneural and classic/mesenchymal subtypes in IDHwt glioma. This demonstrates common phenotypic subtypes across the IDH status with potential therapeutic implications for patients with IDHmut gliomas.</p
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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