SUMMARY Introduction High-flow nasal cannula therapy (HFNC) has been shown to be more effective than continuous positive airway pressure (CPAP) in reducing intubations and ventilator days. HFNC likely provides mechanisms to support respiratory efficiency beyond application of distending pressure. We reason that HFNC washout of nasopharyngeal dead space impacts CO2 removal along with oxygenation. The aim of this study was to demonstrate the flow dependence of CO2 reduction and improved oxygenation during HFNC and the dependence on leak around the nasal prongs. Materials and Methods Neonatal piglets (n=13; 2-6kg) were injured with IV oleic acid and supported with HFNC at 2 through 8 L/minute. High and low leak around the nasal prongs was accomplished by using single and double prong cannulae, respectively. Measurement of hemodynamic, respiratory and blood gas parameters were made at each setting following 10 minutes for physiologic equilibration. Tracheal pressures were recorded by transmural catheters. Results With HFNC, CO2 trended downward in a flow dependent manner independent of leak. Oxygenation and tracheal pressures increased in a flow dependent manner with the greatest effect during double prong. At 8L/minute, tracheal pressures did not exceed 6±1 cmH2O. Conclusions HFNC improves gas exchange in a flow dependent manner; double prong had greater impact on O2; single prong had greater impact on CO2 elimination.
Epigenetic silencing of the lamin A/C gene by CpG island promoter hypermethylation is responsible for the loss of expression of A-type lamins in leukemias and lymphomas. The finding that lamin A/C hypermethylation is associated with poor outcome in diffuse large B-cell lymphomas suggests important clinical implications.
Diffuse large B-cell lymphoma (DLBCL) prognostication requires additional biologic markers. miRNAs may constitute markers for cancer diagnosis, outcome, or therapy response. In the present study, we analyzed the miRNA expression profile in a retrospective multicenter series of 258 DLBCL patients uniformly treated with chemoimmunotherapy. Findings were correlated with overall survival (OS) and progression-free survival (PFS). miRNA and gene-expression profiles were studied using microarrays in an initial set of 36 cases. A selection of miRNAs associated with either DLBCL molecular subtypes (GCB/ABC) or clinical outcome were studied by multiplex RT-PCR in a test group of 240 cases with available formalinfixed, paraffin-embedded (FFPE) diagnostic samples. The samples were divided into a training set (123 patients) and used to derive miRNA-based and combined (with IPI score) Cox regression models in an independent validation series (117 patients). Our model based on miRNA expression predicts OS and PFS and improves upon the predictions based on clinical variables. Combined models with IPI score identified a high-risk group of patients with a 2-year OS and a PFS probability of < 50%. In summary, a precise miRNA signature is associated with poor clinical outcome in chemoimmunotherapy-treated DLBCL patients. This information improves upon IPI-based predictions and identifies a subgroup of candidate patients for alternative therapeutic regimens. (Blood. 2011; 118(4):1034-1040) IntroductionDiffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in adults, accounting for Ͼ 80% of aggressive lymphomas. 1 DLBCL is a heterogeneous group of tumors with different genetic abnormalities, clinical features, responses to treatment, and prognosis. 2 This heterogeneity hinders outcome prediction based on clinical and/or molecular parameters.Combination therapy that associates CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) with rituximab (R-CHOP) has become a standard treatment for DLBCL, leading to complete remission rates of 75%-80% and a 3-to 5-year PFS of 50%-60%. [3][4][5][6][7][8] Nevertheless, patients who fail to respond to first-line therapy or relapse continue to pose a challenge, and identification at diagnosis of poor-outcome cases is crucial for deciding between alternative treatment schemes.The International Prognostic Index (IPI) has been the primary clinical tool for predicting the outcome of patients with aggressive non-Hodgkin lymphoma. 9 Original IPI factors were redistributed in patients treated with R-CHOP to give a revised score (R-IPI) that distinguishes 3 prognostic categories, with 4-year survival rates ranging from 94%-55% for poor-risk patients. 7 Nevertheless, the R-IPI does not discriminate patients with Ͻ 50% probability of survival, which restricts its clinical value. 7 The biologic heterogeneity of DLBCL has been shown substantially to reflect the cell origin of these tumors from germinal center or activated B cells. These differences are significant ind...
Accurate lymphoma diagnosis, prognosis and therapy still require additional markers. We explore the potential relevance of microRNA (miRNA) expression in a large series that included all major B-cell non-Hodgkin lymphoma (NHL) types. The data generated were also used to identify miRNAs differentially expressed in Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL) samples. A series of 147 NHL samples and 15 controls were hybridized on a human miRNA one-color platform containing probes for 470 human miRNAs. Each lymphoma type was compared against the entire set of NHLs. BL was also directly compared with DLBCL, and 43 preselected miRNAs were analyzed in a new series of routinely processed samples of 28 BLs and 43 DLBCLs using quantitative reverse transcription-polymerase chain reaction. A signature of 128 miRNAs enabled the characterization of lymphoma neoplasms, reflecting the lymphoma type, cell of origin and/or discrete oncogene alterations. Comparative analysis of BL and DLBCL yielded 19 differentially expressed miRNAs, which were confirmed in a second confirmation series of 71 paraffin-embedded samples. The set of differentially expressed miRNAs found here expands the range of potential diagnostic markers for lymphoma diagnosis, especially when differential diagnosis of BL and DLBCL is required.
PIM serine/threonine kinases are overexpressed, translocated, or amplified in multiple B-cell lymphoma types. We have explored the frequency and relevance of PIM expression in different B-cell lymphoma types and investigated whether PIM inhibition could be a rational therapeutic approach. Increased expression of PIM2 was detected in subsets of mantle cell lymphoma, diffuse large B-cell lymphoma (DLBLC), follicular lymphoma, marginal zone lymphoma-mucosaassociated lymphoid tissue type, chronic lymphocytic leukemia, and nodal marginal zone lymphoma cases. Increased PIM2 protein expression was associated with an aggressive clinical course in activated B-like-DLBCL patients. Pharmacologic and genetic inhibition of PIM2 revealed p4E-BP1(Thr37/46) and p4E-BP1(Ser65) as molecular biomarkers characteristic of PIM2 activity and indicated the involvement of PIM2 kinase in regulating mammalian target of rapamycin complex 1. The simultaneous genetic inhibition of all 3 PIM kinases induced changes in apoptosis and cell cycle. In conclusion, we show that PIM2 kinase inhibition is a rational approach in DLBCL treatment, identify appropriate biomarkers for pharmacodynamic studies, and provide a new marker for patient stratification. (Blood. 2011;118(20):5517-5527) IntroductionDiffuse large B-cell lymphoma (DLBCL) is the most common type of adult non-Hodgkin lymphoma (NHL), accounting for approximately 40% of all NHL cases. 1 Rather than being a simple entity, it encompasses a constellation of different disorders with varying clinical presentations, molecular pathogenesis, and responses to therapy. 1 Expression-profile studies have revealed the existence of several DLBCL categories, 2 reflecting their origin from discrete B-cell differentiation stages, or the coregulated expression of transcriptional signatures that reflect features of the cell of origin, molecular pathogenesis, or the microenvironment. 1,3,4 Three main subtypes can be distinguished on the basis of the cell-of-origin classification: GCB-DLBCL that express germinal center (GC) genes, activated B-like DLBCL (ABC-DLBCL) with a signature including plasma cell and NF-B-expressed genes, and primary mediastinal DLBCL. 5,6 The standard first-line therapy for treating DLBCL patients is a combination of chemotherapeutical agents (cyclophosphamide, doxorubicin, vincristine, and prednisone [CHOP]) with the rituximab (R) chimeric CD20 monoclonal antibody. 7 Despite this therapy, the disease remains fatal in 30% to 40% of patients. 8 Novel therapeutic opportunities have been proposed based on molecular profiles, suggesting essential regulatory pathways in lymphomas (NF-B pathway, B-cell receptor signaling, B-cell lymphoma 2, B-cell lymphoma 6, and tumor microenvironment) as candidate targets. 9 Although there is a considerable amount of information about the molecular pathogenesis of DLBCL, relatively little progress has been made in developing therapies using compounds that target mutated genes or deregulated pathways. The improved knowledge about the molecular pathogenesis ...
Mantle cell lymphoma (MCL) pathogenesis is still partially unexplained. We investigate the importance of microRNA (miRNA) expression as an additional feature that influences MCL pathway deregulation and may be useful for predicting patient outcome. Twenty-three MCL samples, eight cell lines and appropriate controls were screened for their miRNAs and gene expression profiles and DNA copy-number changes. MCL patients exhibit a characteristic signature that includes 117 miRNA (false discovery rate o0.05). Combined analysis of miRNAs and the gene expression profile, paired with bioinformatics target prediction (miRBase and TargetScan), revealed a series of genes and pathways potentially targeted by a small number of miRNAs, including essential pathways for lymphoma survival such as CD40, mitogen-activated protein kinase and NF-jB. Functional validation in MCL cell lines demonstrated NF-jB subunit nuclear translocation to be regulated by the expression of miR-26a. The expression of 12 selected miRNAs was studied by quantitative PCR in an additional series of 54 MCL cases. Univariate analysis identified a single miRNA, miR20b, whose lack of expression distinguished cases with a survival probability of 56% at 60 months. In summary, using a novel bioinformatics approach, this study identified miRNA changes that contribute to MCL pathogenesis and markers of potential utility in MCL diagnosis and clinical prognostication.
Metabolic stress causes activation of the cJun NH2-terminal kinase (JNK) signal transduction pathway. It is established that one consequence of JNK activation is the development of insulin resistance and hepatic steatosis through inhibition of the transcription factor PPARα. Indeed, JNK1/2 deficiency in hepatocytes protects against the development of steatosis, suggesting that JNK inhibition represents a possible treatment for this disease. However, the long-term consequences of JNK inhibition have not been evaluated. Here we demonstrate that hepatic JNK controls bile acid production. We found that hepatic JNK deficiency alters cholesterol metabolism and bile acid synthesis, conjugation, and transport, resulting in cholestasis, increased cholangiocyte proliferation, and intrahepatic cholangiocarcinoma. Gene ablation studies confirmed that PPARα mediated these effects of JNK in hepatocytes. This analysis highlights potential consequences of long-term use of JNK inhibitors for the treatment of metabolic syndrome.
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