1,907 research outputs found
Translating '–omics' results into precision medicine for hepatocellular carcinoma
A large-scale comprehensive analysis of hepatocellular carcinoma (HCC) based on the integration of six distinct data platforms has pinpointed novel oncogenic processes and prognostic subgroups. These findings confirm previously identified molecular subclasses and fuel the need for a clear strategy of precision medicine in HCC
La regeneració natural després dels incendis forestals a la Comunitat Valenciana
Ecosystem regeneration after wildfire in the Valencia region. The response to wildfires of representative forest ecosystems from the Valencia region is analysed in the present paper. The regenerative strategy of the species that dominate these eco systems is shown to be relevant, as are the physical and nutritional characteristics of the soils where they usually grow. The repercussions of the increasing fire recurrence in the loss of ecosystem regenerative capacity and complexity are discussed. En el present article s'analitza la resposta dels diferents ecosistemes forestals mĂ©s freqĂĽentment afectats per incendis a la Comunitat Valenciana. S'observa la relevancia de l' estratègia regenerativa desprĂ©s del foc de les espècies que dominen aquestes formacions vegetals, aixĂ com les caracterĂstiques fisiques i nutricionals dels diferents tipus de sòls on generalment es desenvolupen. Es discuteix la repercussiĂł de l'increment de la recurrència d' incendis en la pèrdua de la capacitat regenerativa i de la complexitat dels ecosistemes analitzats
Use of the Bethe equation for inner-shell ionization by electron impact
We analyzed calculated cross sections for K-, L-, and M-shell ionization by electron impact to determine the energy ranges over which these cross sections are consistent with the Bethe equation for inner-shell ionization. Our analysis was performed with K-shell ionization cross sections for 26 elements, with L-shell ionization cross sections for seven elements, L-3-subshell ionization cross sections for Xe, and M-shell ionization cross sections for three elements. The validity (or otherwise) of the Bethe equation could be checked with Fano plots based on a linearized form of the Bethe equation. Our Fano plots, which display theoretical cross sections and available measured cross sections, reveal two linear regions as predicted by de Heer and Inokuti [in Electron Impact Ionization, edited by T. D. Mark and G. H. Dunn, (Springer-Verlag, Vienna, 1985), Chap. 7, pp. 232-276]. For each region, we made linear fits and determined values of the two element-specific Bethe parameters. We found systematic variations of these parameters with atomic number for both the low-and the high-energy linear regions of the Fano plots. We also determined the energy ranges over which the Bethe equation can be used
Phosphorylated ERK is a potential predictor of sensitivity to sorafenib when treating hepatocellular carcinoma: evidence from an in vitro study
<p>Abstract</p> <p>Background</p> <p>Sorafenib is the first agent that has demonstrated an improved overall survival benefit in advanced hepatocellular carcinoma (HCC), setting a new standard for first-line treatment. However, no one has yet been able to predict sensitivity to sorafenib. Pre-treatment pERK level has been shown to be associated with favorable response to such therapy in a phase II clinical study, indicating that pERK may be a potential biomarker for treatment of HCC with sorafenib.</p> <p>Methods</p> <p>The effects of sorafenib and 5-fluorouracil (5-FU) on cell proliferation were evaluated by cell viability assays in four HCC cell lines (SMMC-7721, MHCC97-L, MHCC97-H and HCCLM6) with different metastatic potential and basal pERK expression levels. Expression levels of pERK were determined by immunocytochemical quantification together with western blot analysis, and pERK density values were also calculated. Correlation analyses were then carried out between the IC<sub>50 </sub>values of drugs and pERK density values. After basal ERK phosphorylation was down-regulated with U0126 in MHCC97-H cells, cellular responsiveness to sorafenib was assessed by cell viability assay.</p> <p>Results</p> <p>Basal pERK levels increased stepwise in cell lines in accordance with their metastatic potential. Sorafenib inhibited ERK phosphorylation in a dose-dependent manner in all four cell lines at a concentration between 5 and 20 μM, but the degree of inhibition was significantly different according to their basal pERK expression level (<it>P </it>< 0.0001). In contrast, no significant change was observed after 5-FU treatment. Correlation analyses between the IC<sub>50 </sub>values and pERK densities revealed that the effects of sorafenib on cell proliferation were significantly correlated with basal pERK levels (Spearman r = -0.8671, <it>P </it>= 0.0003). Resistance to 5-FU was also significantly associated with basal pERK expression in these HCC cell lines (Spearman r = 0.7832, <it>P </it>= 0.0026). After the basal ERK phosphorylation level in MHCC97-H cells was reduced with U0126, they were significantly less sensitive to sorafenib-mediated growth inhibition, with an IC<sub>50 </sub>of 17.31 ± 1.62 μM versus 10.81 ± 1.24 μM (<it>P </it>= 0.0281).</p> <p>Conclusion</p> <p>In this <it>in vitro </it>study, pERK was confirmed to be a potential biomarker predictive of sensitivity to sorafenib in treating HCC. The RAF/MEK/ERK pathway may be involved in drug resistance to traditional chemotherapy in HCC.</p
A Novel Model Measuring the Harm of Transplanting Hepatocellular Carcinoma Exceeding Milan Criteria
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75159/1/j.1600-6143.2007.02138.x.pd
Comment on: “Investigating Earth’s Formation History Through Copper & Sulfur Metal–Silicate Partitioning During Core-Mantle Differentiation” by Mahan et al. (2018)
The physical and chemical conditions of terrestrial core formation play a key role in the distribution of elements between the Earth’s silicate mantle and metallic core. To explore this, Mahan et al. (2018a) present experimentally-derived partitioning data, showing how Cu distributes itself between metal and silicate at lower-mantle PT conditions with implications for planetary accretion and core formation. Eight experiments were performed in a diamond anvil cell (DAC) and each sample was welded to a copper grid for analysis. An offset in partitioning behaviour was subsequently noted between the high-P experiments and the lower-P dataset. However, when analysing the DAC experiments by electron probe microanalysis, the authors did not account for the secondary fluorescence of Cu that arises from the sample holder. Using Monte Carlo simulations of X-ray and electron transport, we show that the fluorescence of the Cu grid, originating from high energy continuum X-rays emitted from the sample, makes a significant contribution to the reported measurement of Cu in both the silicate and metallic phases. This is in good agreement with previous measurements made on Cu-free analogues. On average, around 70% of the published Cu concentrations are attributable to X-rays that originate externally to the sample. The reported offset in KDmet-sil at high pressures may reflect the different experimental and analytical protocol used, rather than a true pressure effect. Although adequate post-hoc corrections can be made, uncertainties around the exact sample and detector geometries make it difficult to refine simulations and derive accurate correction factors for each experiment
Cost-effectiveness of adjuvant therapy for hepatocellular carcinoma during the waiting list for liver transplantation.
Background: Survival after liver transplantation for early hepatocellular carcinoma (HCC) is worsened by the increasing dropout rate while waiting for a donor.
Aims: To assess the cost effectiveness of adjuvant therapy while waiting for liver transplantation in HCC patients.
Method: Using a Markov model, a hypothetical cohort of cirrhotic patients with early HCC was considered for: (1) adjuvant treatment—resection was limited to Child-Pugh's A patients with single tumours, and percutaneous treatment was considered for Child-Pugh's A and B patients with single tumours unsuitable for resection or with up to three nodules < 3 cm; and (2) standard management. Length of waiting time ranged from six to 24 months.
Results: Surgical resection increased the transplantation rate (>10%) and provided gains in life expectancy of 4.8–6.1 months with an acceptable cost (74 000/life of year gained) for shorter waiting times or high dropout rate scenarios. Percutaneous treatment increased life expectancy by 5.2–6.7 months with a marginal cost of approximately $20 000/year of life gained in all cases, remaining cost effective for all waiting times.
Conclusions: Adjuvant therapies for HCC while waiting for liver transplantation provide moderate gains in life expectancy and are cost effective for waiting lists of one year or more. For shorter waiting times, only percutaneous treatment confers a relevant survival advantage
Multimodality Treatment with Conventional Transcatheter Arterial Chemoembolization and Radiofrequency Ablation for Unresectable Hepatocellular Carcinoma
Background/Aims: To evaluate the efficacy of multimodality treatment consisting of conventional transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA) in patients with non-resectable and non-ablatable hepatocellular carcinoma (HCC). Methods: In this retrospective study, 85 consecutive patients with HCC (59 solitary, 29 multifocal HCC) received TACE followed by RFA between 2001 and 2010. The mean number of tumors per patient was 1.6 +/- 0.7 with a mean size of 3.0 +/- 0.9 cm. Both local efficacy and patient survival were evaluated. Results: Of 120 treated HCCs, 99 (82.5%) showed a complete response (CR), while in 21 HCCs (17.5%) a partial response was depicted. Patients with solitary HCC revealed CR in 91% (51/56); in patients with multifocal HCC (n = 29) CR was achieved in 75% (48 of 64 HCCs). The median survival for all patients was 25.5 months. The 1-, 2-, 3- and 5-year survival rates were 84.6, 58.7, 37.6 and 14.6%, respectively. Statistical analysis revealed a significant difference in survival between Barcelona Clinic Liver Cancer (BCLC) A (73.4 months) and B (50.3 months) patients, while analyses failed to show a difference for Child-Pugh score, Cancer of Liver Italian Program (CLIP) score and tumor distribution pattern. Conclusion: TACE combined with RFA provides an effective treatment approach with high local tumor control rates and promising survival data, especially for BCLC A patients. Randomized trials are needed to compare this multimodality approach with a single modality approach for early-stage HCC. Copyright (C) 2011 S. Karger AG, Base
Molecular Refinement of Clinical Staging in Hepatocellular Carcinoma Patients Evaluated for Potentially Curative Therapies
Abstract: Aim: VEGF and AFP mRNA determinations in the blood are promising prognostic factors for patients with HCC. This study explores their potential prognostic synergy in a cohort of HCC patients evaluated for potentially curative therapies.
Methods: One hundred twenty-four patients with a diagnosis of HCC were prospectively enrolled in the study. Inclusion criteria were: (a) histological diagnosis of HCC and assessment of tumour grade and (b) determination of AFP mRNA status and VEGF levels in the blood before therapy.
Results: At baseline evaluation, 40% of the study group had AFP mRNA in the blood (AFP mRNA positive), and 35% had VEGF > 23 pg ml(-1) (VEGF positive). Surgery was performed in 58 patients (47%), 54 (43%) had tumour ablation, and 12 had chemoembolisation (10%). Median follow-up and survival of the study group were 19 and 26 months (range, 1 to 60), respectively. The association of AFP mRNA and VEGF proved to be prognostically more accurate than their single use in discriminating the risk of death (ROC curve analysis) and survival probability (Cox analysis). In particular, we identified 3 main molecular stages (p < 0,0001): both negative (3-year survival = 63%), one positive (3-year survival = 40%), both positive (3-year survival = 16%). Multivariate analysis identified BCLC staging, surgery, and molecular staging as the most significant survival variables.
Conclusions: The preoperative determination of AFP mRNA status and VEGF may potentially refine the prognostic evaluation of HCC patients and improve the selection process for potentially curative therapies
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