979 resultados para Leukemia, Erythroblastic, Acute


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The term varicocele describes a dilated, tortuous and elongated pampiniform plexus of veins, which is well known in relation to the spermatic cord. Recently varicocele has also been observed inside the testis, and this new entity is known as intra-testicular varicocele. We present a case of intra-testicular varicocele presenting as acute scrotum and discuss the management issues.

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Purpose: Activating mutations in the BRAF oncogene are found in 8% to 15% of colorectal cancer patients and have been associated with poor survival. In contrast with BRAF-mutant (MT) melanoma, inhibition of the MAPK pathway is ineffective in the majority of BRAFMT colorectal cancer patients. Therefore, identification of novel therapies for BRAFMT colorectal cancer is urgently needed.

Experimental Design: BRAFMT and wild-type (WT) colorectal cancer models were assessed in vitro and in vivo. Small-molecule inhibitors of MEK1/2, MET, and HDAC were used, overexpression and siRNA approaches were applied, and cell death was assessed by flow cytometry, Western blotting, cell viability, and caspase activity assays.

Results: Increased c-MET-STAT3 signaling was identified as a novel adaptive resistance mechanism to MEK inhibitors (MEKi) in BRAFMT colorectal cancer models in vitro and in vivo. Moreover, MEKi treatment resulted in acute increases in transcription of the endogenous caspase-8 inhibitor c-FLIPL in BRAFMT cells, but not in BRAFWT cells, and inhibition of STAT3 activity abrogated MEKi-induced c-FLIPL expression. In addition, treatment with c-FLIP–specific siRNA or HDAC inhibitors abrogated MEKi-induced upregulation of c-FLIPL expression and resulted in significant increases in MEKi-induced cell death in BRAFMT colorectal cancer cells. Notably, combined HDAC inhibitor/MEKi treatment resulted in dramatically attenuated tumor growth in BRAFMT xenografts.

Conclusions: Our findings indicate that c-MET/STAT3-dependent upregulation of c-FLIPL expression is an important escape mechanism following MEKi treatment in BRAFMT colorectal cancer. Thus, combinations of MEKi with inhibitors of c-MET or c-FLIP (e.g., HDAC inhibitors) could be potential novel treatment strategies for BRAFMT colorectal cancer.

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New Findings

What is the central question of this study?Exercise performance is limited during hypoxia by a critical reduction in cerebral and skeletal tissue oxygenation. To what extent an elevation in systemic free radical accumulation contributes to microvascular deoxygenation and the corresponding reduction in maximal aerobic capacity remains unknown.What is the main finding and its importance?We show that altered free radical metabolism is not a limiting factor for exercise performance in hypoxia, providing important insight into the fundamental mechanisms involved in the control of vascular oxygen transport.

Exercise performance in hypoxia may be limited by a critical reduction in cerebral and skeletal tissue oxygenation, although the underlying mechanisms remain unclear. We examined whether increased systemic free radical accumulation during hypoxia would be associated with elevated microvascular deoxygenation and reduced maximal aerobic capacity (). Eleven healthy men were randomly assigned single-blind to an incremental semi-recumbent cycling test to determine  in both normoxia (21% O2) and hypoxia (12% O2) separated by a week. Continuous-wave near-infrared spectroscopy was employed to monitor concentration changes in oxy- and deoxyhaemoglobin in the left vastus lateralis muscle and frontal cerebral cortex. Antecubital venous blood samples were obtained at rest and at  to determine oxidative (ascorbate radical by electron paramagnetic resonance spectroscopy), nitrosative (nitric oxide metabolites by ozone-based chemiluminescence and 3-nitrotyrosine by enzyme-linked immunosorbent assay) and inflammatory stress biomarkers (soluble intercellular/vascular cell adhesion 1 molecules by enzyme-linked immunosorbent assay). Hypoxia was associated with increased cerebral and muscle tissue deoxygenation and lower  (P < 0.05 versus normoxia). Despite an exercise-induced increase in oxidative–nitrosative–inflammatory stress, hypoxia per se did not have an additive effect (P > 0.05 versus normoxia). Consequently, we failed to observe correlations between any metabolic, haemodynamic and cardiorespiratory parameters (P > 0.05). Collectively, these findings suggest that altered free radical metabolism cannot explain the elevated microvascular deoxygenation and corresponding lower  in hypoxia. Further research is required to determine whether free radicals when present in excess do indeed contribute to the premature termination of exercise in hypoxia.

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INTRODUCTION: Acute respiratory distress syndrome (ARDS) is a common clinical syndrome with high mortality and long-term morbidity. To date there is no effective pharmacological therapy. Aspirin therapy has recently been shown to reduce the risk of developing ARDS, but the effect of aspirin on established ARDS is unknown.

METHODS: In a single large regional medical and surgical ICU between December 2010 and July 2012, all patients with ARDS were prospectively identified and demographic, clinical, and laboratory variables were recorded retrospectively. Aspirin usage, both pre-hospital and during intensive care unit (ICU) stay, was included. The primary outcome was ICU mortality. We used univariate and multivariate logistic regression analyses to assess the impact of these variables on ICU mortality.

RESULTS: In total, 202 patients with ARDS were included; 56 (28%) of these received aspirin either pre-hospital, in the ICU, or both. Using multivariate logistic regression analysis, aspirin therapy, given either before or during hospital stay, was associated with a reduction in ICU mortality (odds ratio (OR) 0.38 (0.15 to 0.96) P = 0.04). Additional factors that predicted ICU mortality for patients with ARDS were vasopressor use (OR 2.09 (1.05 to 4.18) P = 0.04) and APACHE II score (OR 1.07 (1.02 to 1.13) P = 0.01). There was no effect upon ICU length of stay or hospital mortality.

CONCLUSION: Aspirin therapy was associated with a reduced risk of ICU mortality. These data are the first to demonstrate a potential protective role for aspirin in patients with ARDS. Clinical trials to evaluate the role of aspirin as a pharmacological intervention for ARDS are needed.

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Acute respiratory distress syndrome (ARDS) is a devastating disorder characterized by increased alveolar permeability with no effective treatment beyond supportive care. Current mechanisms underlying ARDS focus on alveolar endothelial and epithelial injury caused by products of innate immune cells and platelets. However, the role of adaptive immune cells in ARDS remains largely unknown. In this study, we report that expansion of Ag-specific αβTh17 cells contributes to ARDS by local secretion of IL-17A, which in turn directly increases alveolar epithelial permeability. Mice with a highly restrictive defect in Ag-specific αβTh17 cells were protected from experimental ARDS induced by a single dose of endotracheal LPS. Loss of IL-17 receptor C or Ab blockade of IL-17A was similarly protective, further suggesting that IL-17A released by these cells was responsible for this effect. LPS induced a rapid and specific clonal expansion of αβTh17 cells in the lung, as determined by deep sequencing of the hypervariable CD3RβVJ region of the TCR. Our findings could be relevant to ARDS in humans, because we found significant elevation of IL-17A in bronchoalveolar lavage fluid from patients with ARDS, and rIL-17A directly increased permeability across cultured human alveolar epithelial monolayers. These results reveal a previously unexpected role for adaptive immune responses that increase alveolar permeability in ARDS and suggest that αβTh17 cells and IL-17A could be novel therapeutic targets for this currently untreatable disease.

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In spite of decades of research, the acute respiratory distress syndrome (ARDS) continues to have an unacceptably high mortality and morbidity. Mesenchymal stromal cells (MSCs) present a promising candidate for the treatment of this condition and have demonstrated benefit in preclinical models. MSCs, which are a topic of growing interest in many inflammatory disorders, have already progressed to early phase clinical trials in ARDS. While a number of their mechanisms of effect have been elucidated, a better understanding of the complex actions of these cells may pave the way for MSC modifications, which might enable more effective translation into clinical practice.

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Acute Kidney Injury(AKI) is common, costly to manage and associated with high mortality. AKI can occur either in the community or in hospitalised patients and may be challenging to recognise because it is typically asymptomatic.Opportunities for prevention of AKI are frequently missed and in the absence of symptoms or signs there is often a delay in recognition ofestablished AKI.Approximately two thirds of hospitalised patients admitted with AKI have developed AKI in the community. AKI in hospitalised patients is associated with a substantial mortality rate > 20%. AKI is a potentially reversible process so improvements in recognition and early interventions could have a major impact on patient outcomes.

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The Bcr-Abl kinase inhibitor, STI571, is the first line treatment for chronic myeloid leukaemia (CML), but the recent emergence of STI571 resistance has led to the examination of combination therapies. In this report, we describe how a novel non-toxic G1-arresting compound, pyrrolo-1,5-benzoxazepine (PBOX)-21, potentiates the apoptotic ability of STI571 in Bcr-Abl-positive CML cells. Co-treatment of CML cells with PBOX-21 and STI571 induced more apoptosis than either drug alone in parental (K562S and LAMA84) and STI571-resistant cells lines (K562R). This potentiation of apoptosis was specific to Bcr-Abl-positive leukaemia cells with no effect observed on Bcr-Abl-negative HL-60 acute myeloid leukaemia cells. Apoptosis induced by PBOX-21/STI571 resulted in activation of caspase-8, cleavage of PARP and Bcl-2, upregulation of the pro-apoptotic protein Bim and a downregulation of Bcr-Abl. Repression of proteins involved in Bcr-Abl transformation, the anti-apoptotic proteins Mcl-1 and Bcl-(XL) was also observed. The combined lack of an early change in mitochondrial membrane potential, release of cytochrome c and cleavage of pro-caspase-9 suggests that this pathway is not involved in the initiation of apoptosis by PBOX-21/STI571. Apoptosis was significantly reduced following pre-treatment with either the general caspase inhibitor Boc-FMK or the chymotrypsin-like serine protease inhibitor TPCK, but was completely abrogated following pre-treatment with a combination of these inhibitors. This demonstrates the important role for each of these protease families in this apoptotic pathway. In conclusion, our data highlights the potential of PBOX-21 in combination with STI571 as an effective therapy against CML.