Cerebral embolization during coronary artery bypass grafting

Universidade Federal de São Paulo, Dept Neurol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurol, BR-04023900 São Paulo, BrazilWeb of Scienc

Transcranial Doppler assessment of cerebral blood flow: Effect of cardiac transplantation

The authors prospectively studied transcranial Doppler changes in patients with refractory congestive heart failure before and after cardiac transplantation. They evaluated 22 patients preoperatively and 14 patients after transplantation. Mean postoperative flow velocity increased by 53.3% (p < 0.0001). Preoperative waveform changes became normal after transplantation.Universidade Federal de São Paulo, Dept Neurol, BR-04039032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Neurol, BR-04039032 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, SP, BrazilWeb of Scienc

Medulloblastoma in adults: a series from Brazil

We retrospectively reviewed 15 adult patients (11 males, median age 34 years; range 23-48) who had been treated and followed in our Institution since 1991 from the time of diagnosis until death or last follow-up in December 2001. Headache was the most frequent symptom (93%). the tumor was hemispheric in 11 patients. Complete resection was achieved in eight. CSF in 12 patients and craniospinal MRI in 6 did not show metastatic disease. Two patients refused adjuvant treatment and died with progressive disease. Thirteen patients received adjuvant craniospinal radiotherapy and 11 systemic chemotherapy. After initial treatment only 2 of the 13 patients relapsed in the posterior fossa. Recurrence was probably related to sub-optimal radiotherapy planning: inadequate low dose in the posterior fossa (37.5 Gy) and long delay in initiating treatment. Two of the 13 patients that received adjuvant treatment died: one from meningitis, and one from recurrent disease. Eleven patients remained alive, and disease-free with Karnofsky performance status ranging 80-100. the median overall survival was not reached after a median follow-up of 5.6 years (range 0.7-10.8 years). Estimated 1-, 5- and 10-year overall survival rates were 86.7%, 72.7%, and 72.7%, respectively. Adult medulloblastoma was predominant in males and the majority of patients had hemispheric tumors. Long-term survival was not uncommon. Although chemotherapy may be useful and well tolerated, radiotherapy remains the mainstay adjuvant treatment as suggested by our two recurrences associated with a delay or inadequate dose.Universidade Federal de São Paulo, Dept Neurol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurosurg, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurol, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Neurosurg, Escola Paulista Med, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, Escola Paulista Med, BR-04023900 São Paulo, BrazilWeb of Scienc

Application of hyperthermia induced by superparamagnetic iron oxide nanoparticles in glioma treatment

Andr&amp;eacute; C Silva1, Tiago R Oliveira1,2, Javier B Mamani1, Suzana MF Malheiros3,4, Luciana Malavolta1, Lorena F Pavon1, Tatiana T Sibov1, Edson Amaro Jr1,5, Alberto Tann&amp;uacute;s6, Edson LG Vidoto6, Mateus J Martins6, Ricardo S Santos6, Lionel F Gamarra11Instituto Israelita de Ensino e Pesquisa Albert Einstein, IIEPAE, S&amp;atilde;o Paulo, Brazil; 2Instituto de F&amp;iacute;sica, Universidade de S&amp;atilde;o Paulo, S&amp;atilde;o Paulo, Brazil; 3Departament of Neurology and Neurosurgery, Universidade Federal de S&amp;atilde;o Paulo, S&amp;atilde;o Paulo, Brazil; 4Neuro-Oncology Program of Hospital Israelita Albert Einstein, S&amp;atilde;o Paulo, Brazil; 5Instituto de Radiologia, Faculdade de Medicina; 6CIERMag-Instituto de F&amp;iacute;sica de S&amp;atilde;o Carlos, Universidade de S&amp;atilde;o Paulo, S&amp;atilde;o Paulo, BrazilAbstract: Gliomas are a group of heterogeneous primary central nervous system (CNS) tumors arising from the glial cells. Malignant gliomas account for a majority of malignant primary CNS tumors and are associated with high morbidity and mortality. Glioblastoma is the most frequent and malignant glioma, and despite the recent advances in diagnosis and new treatment options, its prognosis remains dismal. New opportunities for the development of effective therapies for malignant gliomas are urgently needed. Magnetic hyperthermia (MHT), which consists of heat generation in the region of the tumor through the application of magnetic nanoparticles subjected to an alternating magnetic field (AMF), has shown positive results in both preclinical and clinical assays. The aim of this review is to assess the relevance of hyperthermia induced by magnetic nanoparticles in the treatment of gliomas and to note the possible variations of the technique and its implication on the effectiveness of the treatment. We performed an electronic search in the literature from January 1990 to October 2010, in various databases, and after application of the inclusion criteria we obtained a total of 15 articles. In vitro studies and studies using animal models showed that MHT was effective in the promotion of tumor cell death and reduction of tumor mass or increase in survival. Two clinical studies showed that MHT could be applied safely and with few side effects. Some studies suggested that mechanisms of cell death, such as apoptosis, necrosis, and antitumor immune response were triggered by MHT. Based on these data, we could conclude that MHT proved to be efficient in most of the experiments, and that the improvement of the nanocomposites as well as the AMF equipment might contribute toward establishing MHT as a promising tool in the treatment of malignant gliomas.Keywords: brain tumor, magnetic hyperthermia, magnetic nanoparticl

Stereotactic biopsy guidance in adults with supratentorial nonenhancing gliomas: role of perfusion-weighted magnetic resonance imaging

Object. the diagnosis of low-grade glioma (LGG) cannot be based exclusively on conventional magnetic resonance (MR) imaging studies, and target selection for stereotactic biopsy is a crucial issue given the high risk of sampling errors. the authors hypothesized that perfusion-weighted imaging could provide information on the microcirculation in presumed supratentorial LGGs.Methods. All adult patients with suspected (nonenhancing) supratentorial LGGs on conventional MR imaging between February 2001 and February 2004 were included in this study. Preoperative MR imaging was performed using a dynamic first-pass gadopentate dimeglumine-enhanced spin echo-echo planar perfusion-weighted sequence, and the tumors' relative cerebral blood volume (rCBV) measurements were expressed in relation to the values observed in contralateral white matter. in patients with heterogeneous tumors a stereotactic biopsy was performed in the higher perfusion areas before resection. Among 21 patients (16 men and five women with a mean age of 36 years, range 23-60 years), 10 had diffuse astrocytomas (World Health Organization Grade II) and 11 had other LGGs and anaplastic gliomas. On perfusion-weighted images demonstrating heterogeneous tumors, areas of higher rCBV focus were found to be oligodendrogliornas or anaplastic astrocytomas on stereotactic biopsy; during tumor resection, however, specimens were characterized predominantly as astrocytomas. Diffuse astrocytomas were associated with significantly lower mean rCBV values compared with those in the other two lesion groups (p < 0.01). the rCBV ratio cutoff value that permitted better discrimination between diffuse astrocytomas and the other lesion groups was 1.2 (80% sensitivity and 100% specificity).Conclusions. Perfusion-weighted imaging is a feasible method of reducing the sampling error in the histopathological diagnosis of a presumed LGG, particularly by improving the selection of targets for stereotactic biopsy.Universidade Federal de São Paulo, Ctr Med Diagnost Fleury, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Neurol, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Neurosurg, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Pathol, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Ctr Med Diagnost Fleury, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Neurol, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Neurosurg, BR-01333391 São Paulo, SP, BrazilUniversidade Federal de São Paulo, Dept Pathol, BR-01333391 São Paulo, SP, BrazilWeb of Scienc