183 research outputs found
Differentiated thyroid cancer: A new perspective with radiolabeled somatostatin analogues for imaging and treatment of patients
No full textBackground: The expression of somatostatin receptors (SSTR) in thyroid cells may offer the possibility to identify metastatic lesions and to select patients for peptide receptor radionuclide therapy (PRRT). We investigated 68Ga-DOTATOC positron emission tomography/computed tomography (PET/CT) to select patients with progressive differentiated thyroid cancer (DTC) for PRRT as well as treatment response and toxicity in treated patients. Methods: We enrolled 41 patients with progressive radioiodine-negative DTC (24 women and 17 men; mean age=54.3 years, median=59 years, range=19-78 years). In all patients, [18F]FDG-PET/CT was performed to determine recurrent disease with enhanced glucose metabolism, and 68Ga-DOTATOC PET/CT was used to identify SSTR expression. Dosimetric evaluation was performed with 111In-DOTATOC scintigraphy. Eleven patients were treated with PRRT receiving a fractionated injection of 1.5-3.7 GBq 90Y-DOTATOC/ administration. Serial 68Ga-DOTATOC PET/CT scans were performed in all treated patients to evaluate treatment response. Parameters provided by 68Ga-DOTATOC PET/CT were analyzed as potential therapeutic predictors to differentiate responding from nonresponding. In all treated patients, adverse events and toxicity were recorded. Results: 68Ga-DOTATOC PET/CT were positive in 24/41 of radioiodine-negative DTC patients. Based on the high expression of SSTR detected by 68Ga-DOTATOC PET/CT, 13 patients were suitable for PRRT. Two out of 13 patients were not treated due to the lack of fulfillment of other study inclusion criteria. PRRT induced disease control in 7/11 patients (two partial response and five stabilization) with a duration of response of 3.5-11.5 months. Objective response was associated with symptoms relief. Functional volume (FV) over time obtained by PET/CT was the only parameter demonstrating a significant difference between lesions responding and nonresponding to PRRT (p=0.001). Main PRRT adverse events were nausea, asthenia, and transient hematologic toxicity. One patient experienced permanent renal toxicity. Conclusions: In our series, SSTR imaging provided positive results in more than half of the cases with radioiodine-negative DTC, and about one third of patients were eligible for PRRT. 68Ga-DOTATOC PET/CT seems a reliable tool both for patient selection and evaluation of treatment response. In our experience, FV determination over time seems to represent a reliable parameter to determine tumor response to PRRT, although further investigations are needed to better define its role. © 2014, Mary Ann Liebert, Inc. 2014
Linear ODEs: an Algebraic Perspective
No full textThis booklet was intended to provide a minimum of ready-to-use references for the minicourse given by the author during the XXII E ́scola de Algebra (40 Anos), held in Salvador de Bahia (July 2012). It wishes to bring to the fore a number of relationships with other branches of mathematics. Examples include the theory of symmetric functions, the theory of universal decomposition algebras associated to a polynomial, derivations of the exterior algebra of a free module, D-modules, Schubert calculus for the complex Grassmannian, boson-fermion correspondence in the representation theory of the Heisenberg algebr
Cerebral glucose hypometabolism in Tick-Borne Encephalitis, a pilot study in 10 Patients
No full textAbstractBackgroundTick borne encephalitis (TBE) is an acute meningoencephalitis with or without myelitis caused by an RNA virus from the flavivirus family transmitted by Ixodes spp ticks. The neurotropic TBE virus infects preferentially large neurons in basal ganglia, anterior horns, medulla oblongata, Purkinje cells and thalamus. Brain metabolic changes related to radiologic and clinical findings have not been described so far.MethodsHere we describe the clinical course of 10 consecutive TBE patients with outcome assessment at discharge and after 12 month using a modified Rankin Scale. Patients underwent cerebral MRI after confirmation of diagnosis and before discharge. 18F-FDG PET/CT scans were performed within day 5 to day 14 after TBE diagnosis. Extended analysis of coagulation parameters by thrombelastometry (ROTEM® InTEM, ExTEM, FibTEM) was performed every other day after confirmation of TBE diagnosis up to day 10 after hospital admission or discharge.ResultsAll patients presented with a meningoencephalitic course of disease. Cerebral MRI scans showed unspecific findings at predilection areas in 3 patients. 18F-FDG PET/CT showed increased glucose utilization in one patient and decreased 18F-FDG uptake in seven patients. Changes in coagulation measured by standard parameters and thrombelastometry were not found in any of the patients.DiscussionGlucose hypometabolism was present in 7 out of 10 TBE patients reflecting neuronal dysfunction in predilection areas of TBE virus infiltration responsible for development of clinical signs and symptoms
Local Treatment of Breast Cancer Liver Metastasis
No full textBreast cancer represents a leading cause of death worldwide. Despite the advances in systemic therapies, the prognosis for patients with breast cancer liver metastasis (BCLM) remains poor. Especially in case of failure or cessation of systemic treatments, surgical resection for BCLMs has been considered as the treatment standard despite a lack of robust evidence of benefit. However, due to the extent and location of disease and physical condition, the number of patients with BCLM who are eligible for surgery is limited. Palliative locoregional treatments of liver metastases (LM) include transarterial embolization (TAE), transarterial chemoembolization (TACE), and selective internal radiotherapy (SIRT). Percutaneous thermal ablation methods, such as radiofrequency ablation (RFA) and microwave ablation (MWA), are considered potentially curative local treatment options. They are less invasive, less expensive and have fewer contraindications and complication rates than surgery. Because conventional ultrasound- and computed tomography-guided single-probe thermal ablation is limited by tumor size, multi-probe stereotactic radiofrequency ablation (SRFA) with intraoperative image fusion for immediate, reliable judgment has been developed in order to treat large and multiple tumors within one session. This review focuses on the different minimally invasive local and locoregional treatment options for BCLM and attempts to describe their current and future role in the multidisciplinary treatment setting
Adjustable and Rigid Fixation of Brain Tissue Oxygenation Probe (Licox) in Neurosurgery: From Bench to Bedside
No full text
O-(2-18F-fluoroethyl)-L-tyrosine PET predicts failure of antiangiogenic treatment in patients with recurrent high-grade glioma.
No full textUNLABELLED
The objective of this study was to compare MRI response assessment with metabolic O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET response evaluation during antiangiogenic treatment in patients with recurrent high-grade glioma (rHGG).
METHODS
Eleven patients with rHGG were treated biweekly with bevacizumab-irinotecan. MR images and (18)F-FET PET scans were obtained at baseline and at follow-up 8-12 wk after treatment onset. MRI treatment response was evaluated by T1/T2 volumetry according to response assessment in neurooncology (RANO) criteria. For (18)F-FET PET evaluation, an uptake reduction of more than 45% calculated with a standardized uptake value of more than 1.6 was defined as a metabolic response (receiver-operating-characteristic curve analysis). MRI and (18)F-FET PET volumetry results and response assessment were compared with each other and in relation to progression-free survival (PFS) and overall survival (OS).
RESULTS
At follow-up, MR images showed partial response in 7 of 11 patients (64%), stable disease in 2 of 11 patients (18%), and tumor progression in 2 of 11 patients (18%). In contrast, (18)F-FET PET revealed 5 of 11 metabolic responders (46%) and 6 of 11 nonresponders (54%). MRI and (18)F-FET PET showed that responders survived significantly longer than did nonresponders (10.24 vs. 4.1 mo, P = 0.025, and 7.9 vs. 2.3 mo, P = 0.015, respectively). In 4 patients (36.4%), diagnosis according to RANO criteria and (18)F-FET PET was discordant. In these cases, PET was able to detect tumor progression earlier than was MRI.
CONCLUSION
In rHGG patients undergoing antiangiogenic treatment, (18)F-FET PET seems to be predictive for treatment failure in that it contributes important information to response assessment based solely on MRI and RANO criteria
Secondary structure diagrams of the L20-binding sites on and 23S rRNA and a region of the leader
No full text<p><b>Copyright information:</b></p><p>Taken from "Ribosomal protein L20 controls expression of the operon via a transcription attenuation mechanism"</p><p></p><p>Nucleic Acids Research 2007;35(5):1578-1588.</p><p>Published online 8 Feb 2007</p><p>PMCID:PMC1865079.</p><p>© 2007 The Author(s).</p> A segment of the leader (nts 19–73) comprising the conserved 5′ domain () is drawn to highlight the structural resemblance between the mRNA fold and the L20-binding sites at the junction of helices 40 and 41 (H40/41) on 23S rRNA from and . Numbering corresponds to the mRNA and the respective mature 23S rRNA molecules. The arrow indicates the position of the reverse transcription arrest observed in the presence of L20 (see text and ). The two A residues conserved in eubacterial 23S rRNA are encircled, nucleotides at the interhelical junction conserved between the structures are shown in grey boxes
Effect of leader mutations and the presence of L20 on the transcription profile
No full text<p><b>Copyright information:</b></p><p>Taken from "Ribosomal protein L20 controls expression of the operon via a transcription attenuation mechanism"</p><p></p><p>Nucleic Acids Research 2007;35(5):1578-1588.</p><p>Published online 8 Feb 2007</p><p>PMCID:PMC1865079.</p><p>© 2007 The Author(s).</p> Single round transcription assays were performed on PCR templates comprising the promoter and 5′ noncoding region of using RNA polymerase. RT and T on the left side indicate read-through or prematurely terminated leader transcripts. The size of the marker fragments in bases is indicated. Numbers at the bottom indicate the percentage of read-through transcripts (%RT = (RT/(T + RT) × 100). () Templates were wild type (wt) or contained the A, B or A + B mutations depicted in . () Where indicated proteins were added in 50-fold molar excess over the template during the elongation phase of the single-round transcription assay. The L20 (Bs L20) and L17 (Bs L17) r-proteins were native, L20 (Ec L20) only contained the C-terminal half of the protein
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