233 research outputs found
Combining molecular targeted agents with radiation therapy for malignant gliomas
No full textThe expansion in understanding the molecular biology that characterizes cancer cells has led to the rapid development of new agents to target important molecular pathways associated with aberrant activation or suppression of cellular signal transduction pathways involved in gliomagenesis, including epidermal growth factor receptor, vascular endothelial growth factor receptor, mammalian target of rapamycin, and integrins signaling pathways. The use of antiangiogenic agent bevacizumab, epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib, mammalian target of rapamycin inhibitors temsirolimus and everolimus, and integrin inhibitor cilengitide, in combination with radiation therapy, has been supported by encouraging preclinical data, resulting in a rapid translation into clinical trials. Currently, the majority of published clinical studies on the use of these agents in combination with radiation and cytotoxic therapies have shown only modest survival benefits at best. Tumor heterogeneity and genetic instability may, at least in part, explain the poor results observed with a single-target approach. Much remains to be learned regarding the optimal combination of targeted agents with conventional chemoradiation, including the use of multipathways-targeted therapies, the selection of patients who may benefit from combined treatments based on molecular biomarkers, and the verification of effective blockade of signaling pathways. © 2013 Scaringi et al
Influence of Displacement Rate on Residual Shear Strength of Clays
No full textThis paper reports on the results of direct shear tests carried out under controlled displacement rate in the range of 10-4 -
102 mm/min, under different normal stresses, with different shear devices. The tests were carried out on a kaolin, a bentonite,
their mixtures with sand at various percentages, and the clayey soil of the Costa della Gaveta earthflow. The tests were
performed on specimens reconstituted with distilled water as well as with NaCl solutions at various concentrations. Positive rate
effects were exhibited by mixtures with c.f. higher than 50% and, consistently, by the natural clayey soil the c.f. of which is about
50%. The residual shear strength increases significantly for shear displacement rate higher than about 1 mm/min. The rate effect
increases with the pore solution concentration. The residual shear strength independence of displacement rate has been confirmed
in the range 10-6 - 10-1 mm/min by the results of shear tests performed under controlled shear stress, with varying chemical
conditions of the pore fluid
Effect of inactivated C. albicans on natural killer (NK) cell activity and blastogenesis in mice. P. Marconi, L. Scaringi, A. Cassone, L. Tissi. In: Genetic and Phenotypic Markers of Tumors, (S.A. Aaronson, L. Frati and R. Verna Eds.). Plenum Publishing Corp., New York, London, pp. 145-151, 1985.
No full textChemoselective synthesis of sialic acid 1,7-lactones
No full textThe chemoselective synthesis of the 1,7-lactones of N-acetylneuraminic acid, N-glycolylneuraminic acid, and 3-deoxy-D-glycero-D-galacto-nononic acid is accomplished in two steps: a simple treatment of the corresponding free sialic acid with benzyloxycarbonyl chloride and a successive hydrogenolysis of the formed 2-benzyloxycarbonyl 1,7-lactone. The instability of the 1,7-lactones to protic solvents has been also evidenced together with the rationalization of the mechanism of their formation under acylation conditions. The results permit to dispose of authentic 1,7-sialolactones to be used as reference standards and of a procedure useful for the preparation of their isotopologues to be used as inner standards in improved analytical procedures for the gas liquid chromatography-mass spectrometry (GLC-MS) analysis of 1,7-sialolactones in biological medi
Variazione della composizione del fluido interstiziale delle argille come possibile causa di scorrimento viscoso
No full textDa alcuni anni l’unità di ricerca della Basilicata conduce uno studio teso a valutare l’influenza dei processi chimico-fisici d’interazione fra scheletro solido e fluido di porosità sulla dinamica delle grandi frane attive in terreni argillosi. Questa nota riporta alcuni risultati di una sperimentazione di laboratorio che evidenziano gli effetti provocati da variazioni di composizione del fluido interstiziale sugli scorrimenti di due argille lungo una superficie di rottura in condizioni residue. I materiali sono stati ricostituiti con soluzioni di NaCl a diverse concentrazioni e tagliati a velocità costante fino al residuo in assenza di gradienti chimici. Raggiunta la resistenza residua r, i provini in soluzione sono stati sottoposti a prove di creep da taglio con < r, inducendo così trascurabili spostamenti di tipo primario. Al termine di questa fase, i provini sono stati esposti ad acqua distillata. Dopo l’esposizione si sono verificati scorrimenti con velocità crescente nel tempo fino a valori tipici di una rottura. Il fenomeno è stato attribuito alla riduzione di resistenza causata dalla diminuzione della concentrazione ionica nel fluido interstiziale. Una prima semplice modellazione approssimata dei processi suggerisce che la diffusione ionica dai pori verso il fluido di cella sia stata la causa principale dei comportamenti osservati
Radiation techniques for acromegaly
No full textAbstract Radiotherapy (RT) remains an effective treatment in patients with acromegaly refractory to medical and/or surgical interventions, with durable tumor control and biochemical remission; however, there are still concerns about delayed biochemical effect and potential late toxicity of radiation treatment, especially high rates of hypopituitarism. Stereotactic radiotherapy has been developed as a more accurate technique of irradiation with more precise tumour localization and consequently a reduction in the volume of normal tissue, particularly the brain, irradiated to high radiation doses. Radiation can be delivered in a single fraction by stereotactic radiosurgery (SRS) or as fractionated stereotactic radiotherapy (FSRT) in which smaller doses are delivered over 5-6 weeks in 25-30 treatments. A review of the recent literature suggests that pituitary irradiation is an effective treatment for acromegaly. Stereotactic techniques for GH-secreting pituitary tumors are discussed with the aim to define the efficacy and potential adverse effects of each of these techniques.</p
Effects of multiple treatments with biological response modifiers on development of NK/LAK activity in mice
No full textClay creep and displacements: influence of pore fluid composition
No full textTime dependent shear displacements in clay soils under constant effective stresses can also be induced by changes in pore fluid composition. This paper presents the results of laboratory tests carried out on a sodium bentonite and on samples of the Varicoloured Clays formation outcropping east of Potenza, Southern Italian Apennines. The soils reconstituted with a 1M NaCl solution were submitted to shear tests under constant shear stresses in two different conditions: i) after shearing to the residual state, and ii) intact at various OCR. The applied shear stresses were lower than the residual strength of the materials reconstituted with the salt solution (residual friction angle, ’r ≈ 15°) and higher than that obtained with distilled water (’r ≈ 5°). While exposed to 1M NaCl solution, the specimens didn’t experiment creep; on the contrary, exposure to distilled water made the displacement rate increase greatly. The decrease in pore ion concentration obliterated the over-consolidation effects
Learning Bermudans
No full textAmerican-type financial instruments are often priced with specific Monte Carlo techniques whose efficiency critically depends on the dimensionality of the problem and the available computational power. Our work proposes a novel approach for pricing Bermudan swaptions, well-known interest rate derivatives, using supervised learning algorithms. In particular, we link the price of a Bermudan swaption to its natural hedges, which include the underlying European swaptions, and other relevant financial quantities through supervised learning non-parametric regressions. We explore several algorithms, ranging from linear models to decision tree-based models and neural networks and compare their predictive performances. Our results indicate that all supervised learning algorithms are reliable and fast, with ridge regressor, neural networks, and gradient-boosted regression trees performing the best for the pricing problem. Furthermore, using feature importance techniques, we identify the most important driving factors of a Bermudan swaption price, confirming that the maximum underlying European swaption value is the dominant feature
Temozolomide-related hematologic toxicity
No full textTemozolomide (TMZ) is an oral alkylating agent used for the treatment of recurrent or newly diagnosed malignant gliomas with significant survival benefit. TMZ is generally well tolerated and safe. The most common side effects are mild to moderate, and are represented by fatigue, nausea, vomiting, thrombocytopenia, and neutropenia. However severe hematologic adverse events (HAEs), including myelodysplastic syndrome and aplastic anemia, have also been reported. In this review we present an overview of the available literature of HAEs after exposure to TMZ. © 2013 S. Karger GmbH, Freiburg
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