1,721,245 research outputs found
Volumetric tumor growth rates of meningiomas involving the intracranial venous sinuses
Object: There is currently no consensus as to whether meningiomas located inside the venous sinuses should be aggressively or conservatively treated. The goals of this study were to identify how sinus-invading meningiomas grow, report and compare growth rates of tumor components inside and outside the different venous sinuses, identify risk factors associated with increased tumor growth, and determine the effects of the extent of tumor resection on recurrence for meningiomas that invade the dural venous sinuses. Methods: Adult patients who underwent primary, non-biopsy resection of a WHO grade 1 meningioma invading the dural venous sinuses at a tertiary care institution between 2007 and 2015 were retrospectively reviewed. Rates of tumor growth were fit to several growth models to evaluate the most accurate model. Cohen’s d analysis was used to identify associations with increased growth of tumor in the venous sinuses. Logistic regression was used to compare extent of resection with recurrence. Results: Of the 68 patients included in the study, 34 patients had postoperative residual tumors in the venous sinuses that were measured over time. The growth model that best fit the growth of intrasinus meningiomas was the Gompertzian growth model (r2 = 0.93). The annual growth rate of meningiomas inside the sinuses was 7.3%, compared to extrasinus tumors with 13.6% growth per year. The only factor significantly associated with increased tumor growth in sinuses was preoperative embolization (effect sizes (ES) [95% CI], 1.874 [7.633–46.735], p = 0.008). Conclusions: This study shows that meningiomas involving the venous sinuses have a Gompertzian-type growth with early exponential growth followed by a slower growth rate that plateaus when they reach a certain size. Overall, the growth rate of the intrasinus portion is low (7.3%), which is half of the reported growth rates for other studies involving primarily extrasinus tumors
VM-26 monochemotherapy trial in the treatment of recurrent supratentorial gliomas: preliminary report
Twenty-five adults with recurrent supratentorial malignant gliomas were treated with VM-26 in a monochemotherapy schedule, the antiblastic region covering a period of 24 weeks. Five cases were excluded from the final evaluation, 4 because of protocol violations and 1 due to intolerance to the drug. In the group of 20 patients who met the criteria for evaluation, 7 (35\%) showed a partial or complete response, with clinical or radiological tumor aggression, and the conditions of 7 (35\%) were unchanged at the end of the chemotherapy courses. The progression-free intervals turned out to be 10.4 months and 8.5 months, respectively. Six patients (30\%) complained of tumor progression despite the treatment. Most of the patients are still alive, and the actuarial survival rate is encouraging. Toxicity was mainly hematologic, but usually moderate and easily reversible
Comparison of Anterior Cervical Decompression and Fusion versus Laminoplasty in the Treatment of Multilevel Cervical Spondylotic Myelopathy: A Meta-Analysis of Clinical and Radiological Outcomes
Objective: Spondylotic cervical myelopathy is a severe condition commonly affecting aging people. Although many investigations have been conducted, a consensus on the best surgical management is still missing. The aim of our study was to systematically review the pertinent literature and carry out a meta-analysis to compare the clinical and radiological outcome of the anterior cervical decompression and fusion (ACDF) and the posterior laminoplasty. Methods: This study was conducted in agreement with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines statement. Different medical database (PubMed, Embase, Scopus) were screened for eligible scientific reports. The key words “cervical,” “spondylosis,” “myelopathy,” “laminoplasty,” “ACDF” (MeSH) have been used in any possible combination. As outcome variables, the Japanese Orthopedic Association score, operation time, blood loss, cervical lordosis, range of motion and, complications were evaluated. Results: A total of 626 articles were screened and 5 finally included in the meta-analysis. Comparing the anterior cervical decompression and fusion (ACDF) and laminoplasty groups, no differences were found in Japanese Orthopedic Association score, operation time, and complication rate. The ACDF was associated with lower intraoperative blood loss and better cervical lordosis preservation, whereas the laminoplasty was associated with a wider cervical range of motion. Conclusions: The results of this meta-analysis seem to suggest that ACDF should be preferred to the laminoplasty for the treatment of multilevel cervical myelopathy, although proper designed randomized controlled clinical trials are needed to further investigate this relevant ongoing issue
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
Multidisciplinary treatment of medulloblastoma: a 5-year experience with the SIOP trial
A 5-year experience of the multidisciplinary treatment of pediatric medulloblastoma with the SIOP (International Society of Pediatric Oncology) trial is presented. 33 eligible patients finally reduced to a total of 30 evaluative cases were treated with major surgical resection, extensive irradiation, and combined chemotherapy (vincristine + CCNU). The overall survival rate without recurrence was encouraging, and the actuarial survival rate is satisfactory. At follow-up controls, most of the patients showed a good performance status and a promising neurological stage. However, the problem concerning quality of life remains unsolved: morbidity and sequelae following high-dose radiotherapy and concomitant antiblastic treatment were noticeable
Variations on the Author
“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
Cerebrospinal fluid levels of cyclic nucleotides and monoaminergic metabolites in subarachnoid haemorrhage: preliminary report.
Walk the Line. The Surgical Highways to the Craniovertebral Junction in Endoscopic Approaches: A Historical Perspective
Background: We compiled a comprehensive literature review on the anatomic and clinical results of endoscopic approaches to the craniocervical junction (CVJ) to better contribute to identify the best strategy. Methods: An updated literature review was performed in the PubMed, OVID, and Google Scholar medical databases, using the terms “Craniovertebral junction,” “Transoral approach,” “Transnasal approach,” “Transcervical approach,” “Endoscopic endonasal approach,” “Endoscopic transoral approach,” “Endoscopic transcervical approach.” Clinical series, anatomic studies, and comparative studies were reviewed. Results: Pure endonasal and cervical endoscopic approaches still have some disadvantages, including the learning curve and the deeper surgical field. Endoscopically assisted transoral surgery with 30° endoscopes represents an emerging option to standard microsurgical techniques for transoral approaches to the anterior CVJ. This approach should be considered as complementary rather than an alternative to the traditional microsurgical transoral-transpharyngeal approach. Conclusions: The transoral approach with sparing of the soft palate still remains the gold standard compared with the pure transnasal and transcervical approaches because of the wider working channel provided by the former technique. The transnasal endoscopic approach alone appears to be superior when the CVJ lesion exceeds the upper limit of the inferior third of the clivus
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