157 research outputs found

    A TWO-STAGE METHOD FOR DAMAGE DETECTION OF LARGE-SCALE STRUCTURES

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    ABSTRACT A novel two-stage algorithm for detection of damages in large-scale structures under static loads is presented. The technique utilizes the vector of response change (VRC) and sensitivities of responses with respect to the elemental damage parameters (RSEs). It is shown that VRC approximately lies in the subspace spanned by RSEs corresponding to the damaged elements. The property is leveraged in the first stage of the proposed method by seeking RSEs whose spanned subspace best contains the VRC. Consequently, the corresponding elements are regarded as damage candidates. To alleviate the exploration among RSEs, they are first partitioned into several clusters. Subsequently, discrete ant colony optimization (ACO) is utilized to find the clusters containing the RSEs of damaged elements. In the second stage of the algorithm, damage amounts for the restricted elements are determined using a continuous version of ACO. Two numerical examples are studied. The results illustrate that the method is both robust and efficient for detection of damages in large-scale structures

    Autoantibodies against a 43 KDa Muscle Protein in Inclusion Body Myositis

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    BACKGROUND: Inclusion body myositis (IBM) is a poorly understood and refractory autoimmune muscle disease. Though widely believed to have no significant humoral autoimmunity, we sought to identify novel autoantibodies with high specificity for this disease. METHODOLOGY/PRINCIPAL FINDINGS: Plasma autoantibodies from 65 people, including 25 with IBM, were analyzed by immunoblots against normal human muscle. Thirteen of 25 (52%) IBM patient samples recognized an approximately 43 kDa muscle protein. No other disease (N = 25) or healthy volunteer (N = 15) samples recognized this protein. CONCLUSIONS: Circulating antibodies against a 43-kDa muscle autoantigen may lead to the discovery of a novel biomarker for IBM. Its high specificity for IBM among patients with autoimmune myopathies furthermore suggests a relationship to disease pathogenesis

    Management of refractory/relapsed acute leukemia with heart limitation by anthracycline-free chemotherapy regimens in pediatric patients: New hypothesis and new approach

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    Background: Anthracycline therapy for acute leukemia may be associated with significant morbidity and mortality in children or elderly patients that have a degree of heart failure. Patients with prior anthracycline exposure, those with pre-existing heart disease, or who have received the total anthracycline dose present an increased risk for cardiotoxicity. Therefore, new chemotherapy regimens in these situations would be life saving for leukemia patients. We have conducted a systematic review of possible strategies for rescue regimens without anthracycline in refractory acute leukemia patients. Methods: We gathered the data from 5 creation databases and relevant website until August 2016. We selected randomized clinical trials or other studies that used anthracycline-free chemotherapy regimens to treat acute refractory leukemia in children and adults. The quality of the studies was evaluated according to the Cochrane risk of the polarization tool. All stages of the review were independently conducted by two authors. We obtained data from 75 main clinical trials. Results: There were 75 trials included from which 4 were considered to be at low risk for bias. Most trials showed that the improvement did not reach statistical significance. Conclusion: Evidence existed to support the use of the combination of fludarabine, cytarabine, and filgrastim, ICE-rituximab chemotherapy regimens, or monoclonal antibodies such as tyrosine kinase inhibitors (Sorafenib) useful for acute refractory/relapsed leukemia.These drugs are used as first salvage regimens or clofarabine and cladribine for acute myeloid leukemia in patients for whom combined anthracycline chemotherapy is inappropriate. © 2018, Shiraz University of Medical Sciences. All rights reserved

    Management of refractory/relapsed acute leukemia with heart limitation by anthracycline-free chemotherapy regimens in pediatric patients: New hypothesis and new approach

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    Background: Anthracycline therapy for acute leukemia may be associated with significant morbidity and mortality in children or elderly patients that have a degree of heart failure. Patients with prior anthracycline exposure, those with pre-existing heart disease, or who have received the total anthracycline dose present an increased risk for cardiotoxicity. Therefore, new chemotherapy regimens in these situations would be life saving for leukemia patients. We have conducted a systematic review of possible strategies for rescue regimens without anthracycline in refractory acute leukemia patients. Methods: We gathered the data from 5 creation databases and relevant website until August 2016. We selected randomized clinical trials or other studies that used anthracycline-free chemotherapy regimens to treat acute refractory leukemia in children and adults. The quality of the studies was evaluated according to the Cochrane risk of the polarization tool. All stages of the review were independently conducted by two authors. We obtained data from 75 main clinical trials. Results: There were 75 trials included from which 4 were considered to be at low risk for bias. Most trials showed that the improvement did not reach statistical significance. Conclusion: Evidence existed to support the use of the combination of fludarabine, cytarabine, and filgrastim, ICE-rituximab chemotherapy regimens, or monoclonal antibodies such as tyrosine kinase inhibitors (Sorafenib) useful for acute refractory/relapsed leukemia.These drugs are used as first salvage regimens or clofarabine and cladribine for acute myeloid leukemia in patients for whom combined anthracycline chemotherapy is inappropriate. © 2018, Shiraz University of Medical Sciences. All rights reserved

    Effect of Alemtuzumab (CAMPATH 1-H) in patients with inclusion-body myositis

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    Sporadic inclusion-body myositis (sIBM) is the most common disabling, adult-onset, inflammatory myopathy histologically characterized by intense inflammation and vacuolar degeneration. In spite of T cell-mediated cytotoxicity and persistent, clonally expanded and antigen-driven endomysial T cells, the disease is resistant to immunotherapies. Alemtuzumab is a humanized monoclonal antibody that causes an immediate depletion or severe reduction of peripheral blood lymphocytes, lasting at least 6 months. We designed a proof-of-principle study to examine if one series of Alemtuzumab infusions in sIBM patients depletes not only peripheral blood lymphocytes but also endomysial T cells and alters the natural course of the disease. Thirteen sIBM patients with established 12-month natural history data received 0.3 mg/kg/day Alemtuzumab for 4 days. The study was powered to capture ≥10% increase strength 6 months after treatment. The primary end-point was disease stabilization compared to natural history, assessed by bi-monthly Quantitative Muscle Strength Testing and Medical Research Council strength measurements. Lymphocytes and T cell subsets were monitored concurrently in the blood and the repeated muscle biopsies. Alterations in the mRNA expression of inflammatory, stressor and degeneration-associated molecules were examined in the repeated biopsies. During a 12-month observation period, the patients’ total strength had declined by a mean of 14.9% based on Quantitative Muscle Strength Testing. Six months after therapy, the overall decline was only 1.9% (P < 0.002), corresponding to a 13% differential gain. Among those patients, four improved by a mean of 10% and six reported improved performance of daily activities. The benefit was more evident by the Medical Research Council scales, which demonstrated a decline in the total scores by 13.8% during the observation period but an improvement by 11.4% (P < 0.001) after 6 months, reaching the level of strength recorded 12 months earlier. Depletion of peripheral blood lymphocytes, including the naive and memory CD8+ cells, was noted 2 weeks after treatment and persisted up to 6 months. The effector CD45RA+CD62L­ cells, however, started to increase 2 months after therapy and peaked by the 4th month. Repeated muscle biopsies showed reduction of CD3 lymphocytes by a mean of 50% (P < 0.008), most prominent in the improved patients, and reduced mRNA expression of stressor molecules Fas, Mip-1a and αB-crystallin; the mRNA of desmin, a regeneration-associated molecule, increased. This proof-of-principle study provides insights into the pathogenesis of inclusion-body myositis and concludes that in sIBM one series of Alemtuzumab infusions can slow down disease progression up to 6 months, improve the strength of some patients, and reduce endomysial inflammation and stressor molecules. These encouraging results, the first in sIBM, warrant a future study with repeated infusions (Clinical Trials. Gov NCT00079768)

    Radiation-induced non-targeted effect and carcinogenesis; implications in clinical radiotherapy

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    Bystander or non-targeted effect is known to be an interesting phenomenon in radio-biology. The genetic consequences of bystander effect on non-irradiated cells have shown that this phenomenon can be considered as one of the most important factors involved in secondary cancer after exposure to ionizing radiation. Every year, millions of people around the world undergo radiotherapy in order to cure different types of cancers. The most crucial aim of radiotherapy is to improve treatment efficiency by reducing early and late effects of exposure to clinical doses of radiation. Secondary cancer induction resulted from exposure to high doses of radiation during treatment can reduce the effectiveness of this modality for cancer treatment. The perception of carcinogenesis risk of bystander effects and factors involved in this phenomenon might help reduce secondary cancer incidence years after radiotherapy. Different mo-dalities such as radiation LET, dose and dose rate, fractionation, types of tissue, gender of patients, etc. may be involved in carcinogenesis risk of bystander effects. Therefore, selecting an appropriate treatment modality may improve cost-effectiveness of radiation therapy as well as the quality of life in survived patients. In this review, we first focus on the carcinogenesis evidence of non-targeted effects in radiotherapy and then review physical and biological factors that may influence the risk of secondary cancer induced by this phenomenon. © 2018, Shiraz University of Medical Sciences. All rights reserved
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