Strains of the Burkholderia cepacia complex have emerged as a serious threat to patients with cystic fibrosis due to their ability to infect the lung and cause, in some patients, a necrotizing pneumonia that is often lethal. It has recently been shown that several strains of the B. cepacia complex can escape intracellular killing by free-living amoebae following phagocytosis. In this work, the ability of two B. cepacia complex strains to resist killing by macrophages was explored. Using fluorescence microscopy, electron microscopy and a modified version of the gentamicin-protection assay, we demonstrate that B. cepacia CEP021 (genomovar VI), and Burkholderia vietnamiensis (previously B. cepacia genomovar V) CEP040 can survive in PU5-1.8 murine macrophages for a period of at least 5 d without significant bacterial replication. Furthermore, bacterial entry into macrophages stimulated production of tumour necrosis factor and primed them to release toxic oxygen radicals following treatment with phorbol myristoyl acetate. These effects were probably caused by bacterial LPS, as they were blocked by polymyxin B. Infected macrophages primed with interferon gamma produced less nitric oxide than interferon-gamma-primed uninfected cells. We propose that the ability of B. cepacia to resist intracellular killing by phagocytic cells may play a role in the pathogenesis of cystic fibrosis lung infection. Our data are consistent with a model where repeated cycles of phagocytosis and cellular activation without bacterial killing may promote a deleterious inflammatory response causing tissue destruction and decay of lung function.
Therapy of acute myeloid leukemia in older persons is associated with poor outcomes because of intolerance to intensive therapy, resistant disease and co-morbidities. This multi-center, randomized, open-label, phase II trial compared safety and efficacy of three therapeutic strategies in patients 65 years or over with newly-diagnosed acute myeloid leukemia: 1) continuous high-dose lenalidomide (n=15); 2) sequential azacitidine and lenalidomide (n=39); and 3) azacitidine only (n=34). The efficacy end point was 1-year survival. Median age was 76 years (range 66–87 years). Thirteen subjects (15%) had prior myelodysplastic syndrome and 41 (47%) had adverse cytogenetics. One-year survival was 21% [95% confidence interval (CI): 0, 43%] with high-dose lenalidomide, 44% (95%CI: 28, 60%) with sequential azacitidine and lenalidomide, and 52% (95%CI: 35, 70%) with azacitidine only. Lenalidomide at a continuous high-dose schedule was poorly-tolerated resulting in a high rate of early therapy discontinuations. Hazard of death in the first four months was greatest in subjects receiving continuous high-dose lenalidomide; hazards of death thereafter were similar. These data do not favor use of continuous high-dose lenalidomide or sequential azacitidine and lenalidomide over the conventional dose and schedule of azacitidine only in patients aged 65 years or over with newly-diagnosed acute myeloid leukemia. (clinicaltrials.gov identifier: 01358734).
Myeloid neoplasms are a heterogeneous group of neoplasms including acute myeloid leukemia (AML), myeloproliferative neoplasms, myelodysplastic syndrome, and myeloproliferative neoplasms/myelodysplastic syndrome. Genetic abnormalities are used as diagnostic, prognostic, and predictive biomarkers in patients with these diseases. Herein, we describe the clinical validation of the Oncomine Myeloid Research (OMR) next-generation sequencing panel that interrogates for 40 genes and 29 fusion genes commonly seen in myeloid neoplasms. Our validation set of 77 DNA samples included acute and chronic myeloid neoplasms, with 91 single-nucleotide variants and small insertions/deletions. The 71 RNA samples from patients with AML included most of the AML-defining translocations. The OMR on the Ion Torrent S5 platform shows good performance in terms of depth of coverage, on-target reads, and uniformity. The panel achieved 91.3% and 100% concordance with reference DNA and RNA samples, respectively, with a clinical sensitivity and specificity of 96.7% and 100% for DNA and 99.8% and 100% for RNA, respectively. Precision and reproducibility were 100%, and the lower limit of detection was generally 5% variant allele fraction for DNA and 2-log reduction from initial value for RNA fusion genes. In conclusion, the OMR panel is a highly accurate and reproducible next-generation sequencing panel for the detection of common genetic alterations in myeloid neoplasms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.