Publications by authors named "Petras S"

Introduction: The quality of the initial transurethral resection of bladder tumors (TURBT) plays a key role in accurate local staging thus affecting treatment decision-making and disease prognosis. TURBT is still the gold standard for non-muscle invasive bladder cancer (NMIBC). However, en bloc resection of bladder tumors (ERBT) gradually expanded as a promising alternative to TURBT, aiming to overcome certain inherent limitations of conventional resection.

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Goals: Prospective evaluation of salivary gland preservation, overall survival and local recurrence-free survival after head and neck cancer treated by helical tomotherapy (HT).

Material And Methods: From March 2007 to February 2009, 30 patients with head and neck cancer were treated by HT. The salivary excretion fraction (SEF) was assessed by technetium salivary gland scintigraphy before, and 6, 12 and 18 months after HT to define salivary gland preservation rates.

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Objective: The aim of the study was to evaluate the effect of 2-((18)F)-fluoro-2-deoxy-D-glucose ((18)F-FDG)-PET/computed tomography (CT) respiratory-gated imaging [four-dimensional (4D)] in the metabolic evaluation of small solitary pulmonary nodules and analyze the cutoff maximum standardized uptake value (SUV(max)) of 2.5 in classifying and distinguishing benign/malignant pulmonary pathologies in 4D studies.

Materials And Methods: Thirty-two patients with pulmonary lesions measuring 2 cm or less were included during their scheduled (18)F-FDG PET/CT examinations.

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Article Synopsis
  • The study looked at how well a special type of MRI (called diffusion-weighted MRI) can find liver cancer that comes from uveal melanoma.
  • It involved 20 patients who had surgery to remove their liver tumors, and two doctors examined their MRI images.
  • The results showed that adding diffusion-weighted imaging didn't really help find the cancer better compared to other types of MRI, especially for smaller tumors.
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Introduction: Brain perfusion SPECT is commonly used to evaluate patients with cognitive impairments. Physical limits such as attenuation compromise image quality do not allow the most accurate depiction of radionuclide distribution, and thus, application of attenuation correction (AC) has been recommended. Some reports have demonstrated discordances between the uniform (UAC) and nonuniform CT-based correction (NUAC) procedures.

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We report our first experience of brain DaTSCAN SPECT imaging using cadmium-zinc-telluride gamma camera (CZT-GC) in 2 cases: a 64-year-old patient suffering from essential tremor and a 73-year-old patient presenting with atypical bilateral extrapyramidal syndrome. In both cases, 2 different acquisitions were performed and compared, using a double-head Anger-GC, followed immediately by a second acquisition on CZT-GC. There were no significant visual differences between images generated by different GC.

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Background: Chronic low serum vitamin D concentrations are common among the elderly. Recent studies have suggested that its metabolite, 25-hydroxyvitamin D (25-OHD), might be important for preserving cognitive functions through specific brain protective effects. However, this hypothesis is still under discussion.

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Cerebrovascular disease is recognized as a common cause of cognitive impairment and dementia, alone or coexisting with other neurodegenerative diseases, mostly Alzheimer's disease. Vascular cognitive impairment (VCI) is a part of the heterogenous disorders group related to cerebral vessel disease. Although age is one of the most important risk factors for VCI, other common cardiovascular risk factors are also involved.

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A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor.

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Background: Microscopically complete (R0) resection of metastases from uveal melanoma prolongs median overall survival compared to incomplete surgery. The aim of this study was to compare the sensitivity of dynamic-enhanced magnetic resonance imaging (MRI) with fluorodeoxyglucose-positron emission tomography (FDG-PET) in the preoperative diagnosis of liver metastases from uveal melanoma.

Patients And Methods: Fifteen consecutive patients (mean age: 56 years) underwent FDG-PET and liver MRI.

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Pediatric tumors still represent a formidable challenge despite the considerable therapeutical advances that have been reported for the past 30 years. This is largely related with the untowards side-effects of local therapy that are still acknowledged as the "price for cure". In this setting, Proton therapy a sophisticated radiotherapeutical modality seems to represent a real breakthrough due to its unique ability to spare close and distant normal organs compared with modern photons techniques.

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Proprotein convertase subtilisin/kexin type 9 (PCSK9) is predominantly expressed in liver and regulates cholesterol metabolism by down regulating liver LDL receptor (LDLR) proteins. Here we report transgenic overexpression of human PCSK9 in kidney increased plasma levels of PCSK9 and subsequently led to a dramatic reduction in liver LDLR proteins. The regulation of LDLR by PCSK9 displayed tissue specificity, with liver being the most responsive tissue.

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Sterol regulatory element-binding proteins (SREBPs) are major transcriptional regulators of cholesterol, fatty acid, and glucose metabolism. Genetic disruption of SREBP activity reduces plasma and liver levels of cholesterol and triglycerides and insulin-stimulated lipogenesis, suggesting that SREBP is a viable target for pharmacological intervention. The proprotein convertase SREBP site 1 protease (S1P) is an important posttranscriptional regulator of SREBP activation.

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Purpose: To evaluate outcomes and tolerance of high-dose photon and proton therapy in the management of skull base and cervical canal primary bony malignancies in children.

Patients And Methods: Thirty children were treated postoperatively with high-dose photon-proton (29 patients) or protons-only (1 patient) radiotherapy. Twenty-six patients had chordomas (CH), 3 had low-grade chondrosarcomas (CS), and 1 had an aggressive chondroma (AC).

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The discovery and efficacy of a series of potent aminopyrrolidineamide-based inhibitors of sterol regulatory element binding protein site-1 protease is described.

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Background: The Caenorhabditis elegans genome is known to code for at least 1149 G protein-coupled receptors (GPCRs), but the GPCR(s) critical to the regulation of reproduction in this nematode are not yet known. This study examined whether GPCRs orthologous to human gonadotropin-releasing hormone receptor (GnRHR) exist in C. elegans.

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HMG-CoA reductase inhibitor (statin) treatment is frontline therapy for lowering plasma cholesterol levels in patients with hyperlipidemia. In a few case studies, analysis of clinical data has revealed a decreased risk of fracture in patients on statin therapy. However, this reduction in the incidence of fracture is not always observed nor is it supported by an increase in bone density, which further complicates our understanding of the role of statins in bone metabolism.

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Diabetic dyslipidemia requires simultaneous treatment with hypoglycemic agents and lipid-modulating drugs. We recently described glycogen phosphorylase inhibitors that reduce glycogenolysis in cells and lower plasma glucose in ob/ob mice (J. Med.

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Inhibition of acetyl-CoA carboxylase (ACC), with its resultant inhibition of fatty acid synthesis and stimulation of fatty acid oxidation, has the potential to favorably affect the multitude of cardiovascular risk factors associated with the metabolic syndrome. To achieve maximal effectiveness, an ACC inhibitor should inhibit both the lipogenic tissue isozyme (ACC1) and the oxidative tissue isozyme (ACC2). Herein, we describe the biochemical and acute physiological properties of CP-610431, an isozyme-nonselective ACC inhibitor identified through high throughput inhibition screening, and CP-640186, an analog with improved metabolic stability.

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A microsomal triglyceride transfer protein (MTP) inhibitor, CP-346086, was identified that inhibited both human and rodent MTP activity [concentration giving half-maximal inhibition (IC50) 2.0 nM]. In Hep-G2 cells, CP-346086 inhibited apolipoprotein B (apoB) and triglyceride secretion (IC50 2.

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