669 research outputs found
On the dosimetric impact of inhomogeneity management in the Acuros XB algorithm for breast treatment
BACKGROUND: A new algorithm for photon dose calculation, Acuros XB, has been recently introduced in the Eclipse, Varian treatment planning system, allowing, similarly to the classic Monte Carlo methods, for accurate modelling of dose deposition in media. Aim of the present study was the assessment of its behaviour in clinical cases. METHODS: Datasets from ten breast patients scanned under different breathing conditions (free breathing and deep inspiration) were used to calculate dose plans using the simple two tangential field setting, with Acuros XB (in its versions 10 and 11) and the Anisotropic Analytical Algorithm (AAA) for a 6MV beam. Acuros XB calculations were performed as dose-to-medium distributions. This feature was investigated to appraise the capability of the algorithm to distinguish between different elemental compositions in the human body: lobular vs. adipose tissue in the breast, lower (deep inspiration condition) vs. higher (free breathing condition) densities in the lung. RESULTS: The analysis of the two breast structures presenting densities compatible with muscle and with adipose tissue showed an average difference in dose calculation between Acuros XB and AAA of 1.6%, with AAA predicting higher dose than Acuros XB, for the muscle tissue (the lobular breast); while the difference for adipose tissue was negligible. From histograms of the dose difference plans between AAA and Acuros XB (version 10), the dose of the lung portion inside the tangential fields presented an average difference of 0.5% in the free breathing conditions, increasing to 1.5% for the deep inspiration cases, with AAA predicting higher doses than Acuros XB. In lung tissue significant differences are found also between Acuros XB version 10 and 11 for lower density lung. CONCLUSIONS: Acuros XB, differently from AAA, is capable to distinguish between the different elemental compositions of the body, and suggests the possibility to further improve the accuracy of the dose plans computed for actual treatment of patients
The Mucosae-Associated Epithelial Chemokine (MEC/CCL28) Modulates Immunity in HIV Infection
BACKGROUND.
CCL28 (MEC) binds to CCR3 and CCR10 and recruits IgA-secreting plasma cells (IgA-ASC) in the mucosal lamina propria (MLP). Mucosal HIV-specific IgA are detected in HIV-infection and exposure. The CCL28 circuit was analyzed in HIV-infected and-exposed individuals and in HIV-unexposed controls; the effect of CCL28 administration on gastrointestinal MLP IgA-ASC was verified in a mouse model.
METHODOLOGY/FINDINGS.
CCL28 was augmented in breast milk (BM) plasma and saliva of HIV-infected and –exposed individuals; CCR3+ and CCR10+ B lymphocytes were increased in these same individuals. Additionally: 1) CCL28 concentration in BM was associated with longer survival in HIV vertically-infected children; and 2) gastro-intestinal mucosal IgA-ASC were significantly increased in VSV-immunized mice receiving CCL28. CONCLUSIONS. CCL28 mediates mucosal immunity in HIV exposure and infection. CCL28-including constructs should be considered in mucosal vaccines to prevent HIV infection of the gastro-intestinal MLP via modulation of IgA-ASC.Istituto Superiore di Sanita' "Programma Nazionale di Ricerca sull' AIDS"; DG Right to Health and Solidarity Policy; EMPRO and AVIP EC WP6 Projects; Japan Health Science Foundation; National Institutes of Child Health and Human Development (HD 39611, HD 40777
Neither for, nor against Mao: PCI-CCP interactions and the normalisation of Sino-Italian relations, 1966-71
This paper explores the Italian Communist Party (PCI)’s interactions with the Chinese Communist Party (CCP) in the years immediately preceding the normalisation of Sino-Italian relations. The present work highlights three aspects of this dynamic: the PCI’s rewriting of its identity as a foreign policy making actor independent of the US, the USSR, and neither dismissive nor laudatory of Mao; the PCI’s establishment of partnerships with actors at home and abroad to allow for its China-policy blueprints to come to fruition; and the efforts of PCI-affiliated intellectuals toward making a rapprochement between the PCI and the CCP possible
Hippocampus avoidance with fan beam and volumetric arc radiotherapy for base of skull tumours
Radiosensitive neurogenic stem cells reside in the hippocampi, suggesting that avoidance of the hippocampi may be an important strategy to reduce potential radiation-related cognitive effects. Six patients treated for base of skull tumours were re-planned using co-planar helical fan beam arc therapy (tomotherapy) and co-planar and non-coplanar volumetric arc techniques (RapidArc). The hippocampi were contoured as avoidance structures with the specific goal of minimising the dose. Two gross target volume (GTV) to planning target volume (PTV) expansions (10 and 2 mm) were considered to evaluate the impact of margin selection on organ at risk (OAR) sparing. The dose prescription was 50 Gy to >95% of the PTV. Comparison of the hippocampus avoidance plans demonstrated the importance of non-coplanar delivery when the 10 mm margin was used. With the 2 mm margin, both co-planar and non-coplanar delivery provided similar degrees of sparing. A mean dose of 3-4 Gy and a V6Gy <5% to the hippocampi was realised with the hippocampus sparing techniques. Our comparisons suggest interventions to minimise GTV to PTV margins will have a more profound influence on multiple OAR sparing than the choice of intensity modulated arc delivery techniqu
Asuransi bagi Akun Game Online untuk Risiko Peretasan
Online games are a type of entertainment that is the result of technological developments that occur in this era of globalization. Indonesia is a country with a very large number of active internet users. Most of the active internet users in Indonesia are online game players. Online games are categorized as a digital asset because players can collect various virtual items. Also, the high level and how high the rank that has been achieved in a game account has its own economic value in the eyes of the players. That makes an online game account has its own economic value and is an asset that must be maintained. An online game account owner is also not immune to the risk of losing their account. One of the unavoidable risks is losing an online game account due to hacker attacks. Hackers can hack into a person's online gaming account and take ownership of it. The risk of hacking is a threat that is not expected to happen. By holding online game account insurance from the threat of hacking, it can divert the risk of online game account owners who are exposed to hacker attacks
La participación arterial en los síndromes varicosos del miembro inferior
Presented at session 12th May 1943Presentado en sesión de 12 de mayo de 194
Cirugía de la aorta abdominal: 2 casos
Presented at session 28th July 1943Presentado en sesión de 28 de julio de 194
Characterization of a new trabectedin-resistant myxoid liposarcoma cell line that shows collateral sensitivity to methylating agents
Myxoid Liposarcomas (MLS), characterized by the expression of FUS-CHOP fusion gene are clinically very sensitive to the DNA binding antitumor agent, trabectedin. However, resistance eventually occurs, preventing disease eradication. To investigate the mechanisms of resistance, a trabectedin resistant cell line, 402-91/ET, was developed. The resistance to trabectedin was not related to the expression of MDR related proteins, uptake/efflux of trabectedin or GSH levels that were similar in parental and resistant cells. The 402-91/ET cells were hypersensitive to UV light because of a nucleotide excision repair defect: XPG complementation decreased sensitivity to UV rays, but only partially to trabectedin. 402-91/ET cells showed collateral sensitivity to temozolomide due to the lack of O(6) -methylguanine-DNA-methyltransferase (MGMT) activity, related to the hypermethylation of MGMT promoter. In 402-91 cells chromatin immunoprecipitation (ChIP) assays showed that FUS-CHOP was bound to the PTX3 and FN1 gene promoters, as previously described, and trabectedin caused FUS-CHOP detachment from DNA. Here we report that, in contrast, in 402-91/ET cells, FUS-CHOP was not bound to these promoters. Differences in the modulation of transcription of genes involved in different pathways including signal transduction, apoptosis and stress response between the two cell lines were found. Trabectedin activates the transcription of genes involved in the adipogenic-program such as c/EBPα and β, in 402-91 but not in 402-91/ET cell lines. The collateral sensitivity of 402-91/ET to temozolomide provides the rationale to investigate the potential use of methylating agents in MLS patients resistant to trabectedin
Cirrosis de Hanot y Litiasis biliar
Presented at session 31th July 1935Presentado en sesión de 31 de julio de 193
- …
