415 research outputs found

    Design-oriented approach to predict shear strength of reinforced concrete beams

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    There are different approaches to predict the shear strength of reinforced concrete (RC) beams, but their predictive performance is still relatively low due to several and complex resisting mechanisms involved in shear. In addition, most of design approaches ignore the influence of the flange of T cross section beams on the ultimate shear capacity. This paper aims to present a design‐oriented approach to predict the load carrying capacity of RC beams failing in shear. This approach is based on the simplified modified compression field theory (SMCFT). A sensitivity analysis is carried out to assess the importance of the input parameters that mostly affect the shear strength of RC members. Taking into account the results of the sensitivity analysis, two simple equations are proposed for obtaining the: (a) tensile stress factor in the cracked concrete (β) and (b) inclination of the diagonal compressive stress in the web of the section (θ). The obtained equations eliminate the iterative process required by the SMCFT and provide a straightforward design methodology to find β and θ with suitable accuracy for design purposes. In addition, a coefficient is presented to take into account the effect of the flange on the shear capacity of T shaped cross section beams. To appraise the predictive performance of the new approach, a database is set. By evaluating the ratio between the experimental results and the analytical predictions, an average value of 1.24 with a coefficient of variation of 20.9% is obtainedFundação para a Ciência e a Tecnologia. Grant Number: SFRH/BSAB/114302/201

    Outcome of older (≥70 years) APL patients frontline treated with or without arsenic trioxide-an International Collaborative Study

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    Data on outcome in older (≥70 years) patients with acute promyelocytic leukemia after treatment with arsenic trioxide (ATO) compared with standard chemotherapy (CTX) is scarce. We evaluated 433 patients (median age, 73.4 years) treated either with ATO+ all-trans retinoic acid (ATO/ATRA; n = 26), CTX/ATRA + ATO during consolidation (CTX/ATRA/ATO; n = 148), or with CTX/ATRA (n = 259). Median follow-up for overall survival (OS) was 4.8 years. Complete remissions (CR) were achieved in 92% with ATO/ATRA and 82% with CTX/ATRA; induction death rates were 8% and 18%, respectively. For analysis of postremission outcomes we combined the ATO/ATRA and CTX/ATRA/ATO groups (ATO/ATRA ± CTX). Cumulative incidence of relapse (CIR) was significantly lower after ATO/ATRA ± CTX compared with CTX/ATRA (P 10 × 10 9 /l) white blood cell (WBC) counts at diagnosis were associated with higher CIR (P < 0.001) compared with lower WBC in the CTX/ATRA group, but not in the ATO/ATRA ± CTX group (P = 0.48). ATO, when added to ATRA or CTX/ATRA is feasible and effective in elderly patients for remission induction and consolidation, particularly in patients with high WBC at diagnosis

    Prognostic impact of a suboptimal number of analyzed metaphases in normal karyotype lower-risk MDS

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    Conventional karyotype is one of the most relevant prognostic factors in MDS. However, about 50% of patients with MDS have a normal karyotype. Usually, 20-25 normal metaphases (nMP) are considered to be optimal to exclude small abnormal clones which might be associated with poor prognosis. This study evaluated the impact of examining a suboptimal number of metaphases in patients recruited to the EUMDS Registry with low and intermediate-1 risk according to IPSS. Only 179/1049 (17%) of patients with a normal karyotype had a suboptimal number of nMP, defined as less than 20 metaphases analyzed. The outcome (overall survival and progression-free survival) of patients with suboptimal nMP was not inferior to those with higher numbers of analyzed MP both in univariate and multivariate analyses. For patients with an abnormal karyotype, 224/649 (35%) had a suboptimal number of MP assessed, but this did not impact on outcome. For patients with a normal karyotype and suboptimal numbers of analyzable metaphases standard evaluation might be acceptable for general practice, but we recommend additional FISH-analyses or molecular techniques, especially in candidates for intensive interventions

    Blood-Brain Barrier Cellular Responses Toward Organophosphates: Natural Compensatory Processes and Exogenous Interventions to Rescue Barrier Properties

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    Organophosphorus compounds (OPs) are highly toxic chemicals widely used as pesticides (e.g., paraoxon (PX)- the active metabolite of the insecticide parathion) and as chemical warfare nerve agents. Blood-brain barrier (BBB) leakage has been shown in rodents exposed to PX, which is an organophosphate oxon. In this study, we investigated the cellular mechanisms involved in BBB reaction after acute exposure to PX in an established in vitro BBB system made of stem-cell derived, human brain-like endothelial cells (BLECs) together with brain pericytes that closely mimic the in vivo BBB. Our results show that PX directly affects the BBB in vitro both at toxic and non-toxic concentrations by attenuating tight junctional (TJ) protein expression and that only above a certain threshold the paracellular barrier integrity is compromised. Below this threshold, BLECs exhibit a morphological coping mechanism in which they enlarge their cell area thus preventing the formation of meaningful intercellular gaps and maintaining barrier integrity. Importantly, we demonstrate that reversal of the apoptotic cell death induced by PX, by a pan-caspase-inhibitor ZVAD-FMK (ZVAD) can reduce PX-induced cell death and elevate cell area but do not prevent the induced BBB permeability, implying that TJ complex functionality is hindered. This is corroborated by formation of ROS at all toxic concentrations of PX and which are even higher with ZVAD. We suggest that while lower levels of ROS can induce compensating mechanisms, higher PX-induced oxidative stress levels interfere with barrier integrity

    Arsenic trioxide is required in the treatment of newly diagnosed acute promyelocytic leukemia. Analysis of a randomized trial (APL 2006) by the French Belgian Swiss APL group.

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    In standard-risk acute promyelocytic leukemia, recent results have shown that all-trans retinoic acid plus arsenic trioxide combinations are at least as effective as classical all-trans retinoic acid plus anthracycline-based chemotherapy while being less myelosuppressive. However, the role of frontline arsenic trioxide is less clear in higher-risk acute promyelocytic leukemia, and access to arsenic remains limited for front-line treatment of standard-risk acute promyelocytic leukemia in many countries. In this randomized trial, we compared arsenic, all-trans retinoic acid and the "classical" cytarabine for consolidation treatment (after all-trans retinoic acid and chemotherapy induction treatment) in standard-risk acute promyelocytic leukemia, and evaluated the addition of arsenic during consolidation in higher-risk disease. Patients with newly diagnosed acute promyelocytic leukemia with a white blood cell count &lt;10x10 &lt;sup&gt;9&lt;/sup&gt; /L, after an induction treatment consisting of all-trans retinoic acid plus idarubicin and cytarabine, received consolidation chemotherapy with idarubicin and cytarabine, arsenic or all-trans retinoic acid. Patients with a white blood cell count &gt;10x10 &lt;sup&gt;9&lt;/sup&gt; /L received consolidation chemotherapy with or without arsenic. Overall, 795 patients with acute promyelocytic leukemia were enrolled in this trial. Among those with standard-risk acute promyelocytic leukemia (n=581), the 5-year event-free survival rates from randomization were 88.7%, 95.7% and 85.4% in the cytarabine, arsenic and all-trans retinoic acid consolidation groups, respectively (P=0.0067), and the 5-year cumulative incidences of relapse were was 5.5%, 0% and 8.2%. (P=0.001). Among those with higher-risk acute promyelocytic leukemia (n=214), the 5-year event-free survival rates were 85.5% and 92.1% (P=0.38) in the chemotherapy and chemotherapy plus arsenic groups, respectively, and the corresponding 5-year cumulative incidences of relapse were 4.6% and 3.5% (P=0.99). Given the prolonged myelosuppression that occurred in the chemotherapy plus arsenic arm, a protocol amendment excluded cytarabine during consolidation cycles in the chemotherapy plus arsenic group, resulting in no increase in relapse. Our results therefore advocate systematic introduction of arsenic in the first-line treatment of acute promyelocytic leukemia, but probably not concomitantly with intensive chemotherapy, a situation in which we found myelosuppression to be significant. (ClinicalTrials.gov Identifier: NCT00378365)

    Acupuncture for the treatment of severe acute pain in Herpes Zoster: results of a nested, open-label, randomized trial in the VZV Pain Study

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    <p>Abstract</p> <p>Background</p> <p>Data on the potential efficacy of acupuncture (AC) in controlling intense or very intense pain in patients with Herpes Zoster (HZ) has not been so far adequately assessed in comparison with standard pharmacological treatment (ST) by a controlled trial design.</p> <p>Methods</p> <p>Within the VZV Pescara study, pain was assessed in HZ patients on a Visual Analogue Scale (VAS) and by the McGill Pain Questionnaire (MPQ) both at the beginning and at the end of treatment. Response rates, mean changes in pain intensity, differences in total pain burden with an area-under-the-curve (AUC) method over a 1-year follow-up and differences in the incidence of Post-Herpetic Neuralgia (PHN) were evaluated.</p> <p>Results</p> <p>One hundred and two patients were randomized to receive either AC (n = 52) or ST (n = 50) for 4 weeks. Groups were comparable regarding age, sex, pain intensity at presentation and missed antiviral prescription. Both interventions were largely effective. No significant differences were observed in response rates (81.6% vs 89.2%, p = 0.8), mean reduction of VAS (4.1 +/- 2.3 vs 4.9 +/- 1.9, p = 0.12) and MPQ scores (1.3 +/- 0.9 vs 1.3 +/- 0.9, p = 0.9), incidence of PHN after 3 months (48.4% vs 46.8%, p = 0.5), and mean AUC during follow-up (199 +/- 136 vs 173 +/- 141, p = 0.4). No serious treatment-related adverse event was observed in both groups.</p> <p>Conclusions</p> <p>This controlled and randomized trial provides the first evidence of a potential role of AC for the treatment of acute herpetic pain.</p> <p>Trial registration</p> <p>ChiCTR-TRC-10001146.</p

    Impact of treatment with iron chelation therapy in patients with lower-risk myelodysplastic syndromes participating in the European MDS registry

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    Iron overload due to red blood cell transfusions is associated with morbidity and mortality in lower-risk myelodysplastic syndrome patients. Many studies suggested improved survival after iron chelation therapy, but valid data are limited. The aim of this study was to assess the effect of iron chelation on overall survival and hematological improvement in lower-risk myelodysplastic syndrome patients in the European MDS registry. We compared chelated patients with a contemporary, non-chelated control group within the European MDS registry, that met the eligibility criteria for starting iron chelation. A Cox proportional hazards model was used to assess overall survival, treating receipt of chelation as a time-varying variable. Additionally, chelated and non-chelated patients were compared using a propensity-score matched model. Of 2200 patients, 224 received iron chelation. The hazard ratio and 95% confidence interval for overall survival for chelated patients, adjusted for age, sex, comorbidity, performance status, cumulative red blood cell transfusions, IPSS-R, and presence of ringed sideroblasts was 0.50 (0.34-0.74). The propensity-score analysis, matched for age, sex, country, red blood cell transfusion intensity, ferritin level, comorbidity, performance status, and IPSS-R and additionally corrected for cumulative red blood cell transfusions and presence of ringed sideroblasts, demonstrated a significantly improved overall survival for chelated patients with a hazard ratio of 0.42 (0.27-0.63) compared to non-chelated patients. Up to 39% of chelated patients reached an erythroid response. In conclusion, our results suggest that iron chelation may improve overall survival and hematopoiesis in transfused lower-risk myelodysplastic syndrome patients. This trial was registered at www.clinicaltrials.gov as #NCT00600860
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