168 research outputs found
Photoluminescence and concentration quenching of Pr3+ doped BaTa2O6 phosphor
The pure and Pr3+ doped TTB-BaTa2O6 phosphors were obtained by the solid state reaction method at 1 425 °C for 20hours. X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses confirmed a single phase of BaTa2O6up to 10 mol % Pr2O36. SEM analysis also shows that BaTa2O6 grain size decreased with the increasing Pr2O36 concentration.The chemical composition of Pr3+ doped BaTa2O6 structures was confirmed by Energy Dispersive Spectroscopy(EDS) analysis. BaTa2O6:Pr3+ phosphors exhibited on a strong red emission at 620,9 nm, a green emission at 548,3 nm and a red emission at 655,2 nm. Emission intensity increased with Pr3+ doping concentration up to 1,5 mol %, then decreased due to concentration quenching
Getting lost in a story: how narrative engagement emerges from narrative perspective and individual differences in alexithymia
The present research examines how narrative engagement, or the extent to which people immerse themselves into the world of a story, varies as a function of narrative perspective and individual differences in alexithymia. The authors hypothesised that narrative engagement would be higher when people assume a first-person (rather than third-person) perspective and for people lower (rather than higher) on alexithymia. In an online study (N = 541) and a lab study (N = 55), participants with varying levels of alexithymia read first- and/or third-person narrated texts and then rated their narrative engagement. As expected, first-person stories evoked more narrative engagement than third-person stories, and global alexithymia was negatively correlated with narrative engagement. Narrative perspective did not interact with cognitive facets of alexithymia (i.e. difficulties identifying, verbalising, and understanding feelings). However, narrative perspective did interact with affective facets of alexithymia (i.e. emotionalising and fantasising): First-person (rather than third-person) stories elicited more narrative engagement at lower levels of affective alexithymia, but not at higher levels of affective alexithymia. The interaction effect was significant in Study 1; the interaction was significant in Study 2 after controlling for trait absorption. Together, these findings suggest that alexithymia is linked to difficulties in mentally simulating narrative worlds.Pathways through Adolescenc
Therapeutic vulnerability of multiple myeloma to MIR17PTi, a first-in-class inhibitor of pri-mir-17-92
The microRNA cluster miR-17-92 is oncogenic and represents a valuable therapeutic target in c-MYC (MYC)-driven malignancies. Here, we developed novel LNA gapmeR antisense oligonucleotides (ASOs) to induce RNase H-mediated degradation of MIR17HG primary transcripts and, consequently, to prevent biogenesis of miR-17-92 microRNAs (miR-17-92s). The leading LNA-ASO, named MIR17PTi, impaired proliferation of several cancer cell lines (n=48) established from both solid and hematologic tumors by on-target antisense activity, and more effectively as compared to miR-17-92s inhibitors. By focusing on multiple myeloma (MM), we found that MIR17PTi triggers apoptosis via impairment of homeostatic MYC/miR-17-92 feed-forward loops (FFLs) in patient-derived MM cells; and induced MYC-dependent synthetic lethality. We show that alteration of a BIM-centered FFL is instrumental for MIR17PTi to induce cytotoxicity in MM cells. MIR17PTi exerts strong in vivo anti-tumor activity in NOD-SCID mice bearing clinically relevant models of MM, with advantageous safety and pharmacokinetics profiles in non-human primates. Altogether, MIR17PTi is a novel pharmacological tool to be tested in early-phase clinical trials against MM and other MYC-driven malignancies
Clinical features associated with COVID-19 outcome in multiple myeloma: first results from the International Myeloma Society data set
The primary cause of morbidity and mortality in patients with multiple myeloma(MM) is an infection. Therefore there is great concern about the susceptibility to the outcome of COVID-19 infected patients with MM. This retrospective study describes the baseline characteristics and outcome data of COVID-19 infection in 650 patients with plasma cell disorders, collected by the International Myeloma Society to understand the initial challenges faced by myeloma patients during COVID-19 pandemic. Analysis were performed for hospitalized MM patients. Among hospitalized patinets, the median age was 69 years, and nearly all patients(96%) had MM. Approximately 36% were recently diagnosed(2019-2020), and 54% of patients were receiving first-line therapy. Thirty-three percent of patients have died, with significant geographic variability, ranging from 27% to 57% of hospitalized patients. Univariate analysis identified age, ISS3, high-risk disease, renal disease, suboptimal myeloma control(active or progressive disease), and one or more comorbidities as risk factors for higher rates of death. Neither history of transplant, including within a year of COVID-19 diagnosis, nor other anti-MM treatments were associated with outcomes. Multivariate analysis found that only age, high-risk MM, renal disease, and suboptimal MM control remained independent predictors of adverse outcome with COVID-19 infection. The management of MM in the era of COVID-19 requires careful consideration of patient and disease-related factors to decrease the risk of acquiring COVID-19 infection, while not compromising disease control through appropriate MM treatment. This study provides initial data to develop recommendations for the management of MM patients with COVID-19 infection
On limit theorems for continued fractions
It is shown that for sums of functionals of digits in continued fraction
expansion the Kolmogorov-Feller weak laws of large numbers and the
Khinchine-L\'evy-Feller-Raikov characterization of the domain of attraction of
the normal law hold.Comment: 16 page
RIP4 inhibits STAT3 signaling to sustain lung adenocarcinoma differentiation.
Loss of epithelial differentiation and extracellular matrix (ECM) remodeling are known to facilitate cancer progression and are associated with poor prognosis in patients with lung cancer. We have identified Receptor-interacting serine/threonine protein kinase 4 (RIP4) as a regulator of tumor differentiation in lung adenocarcinoma (AC). Bioinformatics analyses of human lung AC samples showed that poorly differentiated tumors express low levels of RIP4, whereas high levels are associated with better overall survival. In vitro, lung tumor cells expressing reduced RIP4 levels showed enhanced activation of STAT3 signaling and had a greater ability to invade through collagen. In contrast, overexpression of RIP4 inhibited STAT3 activation, which abrogated interleukin-6-dependent induction of lysyl oxidase, a collagen cross-linking enzyme. In an autochthonous mouse model of lung AC initiated by Kras(G12D) expression with loss of p53, Rip4 knockdown tumors progressed to a poorly differentiated state marked by an increase in Hmga2, reduced Ttf1, and enrichment of genes regulating extracellular remodeling and Jak-Stat signaling. Tail vein injections of cells overexpressing Rip4 showed a reduced potential to invade and form tumors, which was restored by co-expression of Stat3. Altogether, our work has identified that loss of RIP4 enhances STAT3 signaling in lung cancer cells, promoting the expression of ECM remodeling genes and cancer dedifferentiation
A high-risk, Double-Hit, group of newly diagnosed myeloma identified by genomic analysis
Patients with newly diagnosed multiple myeloma (NDMM) with high-risk disease are in need of new treatment strategies to improve the outcomes. Multiple clinical, cytogenetic, or gene expression features have been used to identify high-risk patients, each of which has significant weaknesses. Inclusion of molecular features into risk stratification could resolve the current challenges. In a genome-wide analysis of the largest set of molecular and clinical data established to date from NDMM, as part of the Myeloma Genome Project, we have defined DNA drivers of aggressive clinical behavior. Whole-genome and exome data from 1273 NDMM patients identified genetic factors that contribute significantly to progression free survival (PFS) and overall survival (OS) (cumulative R2 = 18.4% and 25.2%, respectively). Integrating DNA drivers and clinical data into a Cox model using 784 patients with ISS, age, PFS, OS, and genomic data, the model has a cumlative R2 of 34.3% for PFS and 46.5% for OS. A high-risk subgroup was defined by recursive partitioning using either a) bi-allelic TP53 inactivation or b) amplification (≥4 copies) of CKS1B (1q21) on the background of International Staging System III, comprising 6.1% of the population (median PFS = 15.4 months; OS = 20.7 months) that was validated in an independent dataset. Double-Hit patients have a dire prognosis despite modern therapies and should be considered for novel therapeutic approaches
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Nucleotide excision repair is a potential therapeutic target in multiple myeloma
Despite the development of novel drugs, alkylating agents remain an important component of therapy in multiple myeloma (MM). DNA repair processes contribute towards sensitivity to alkylating agents and therefore we here evaluate the role of nucleotide excision repair (NER), which is involved in the removal of bulky adducts and DNA crosslinks in MM. We first evaluated NER activity using a novel functional assay and observed a heterogeneous NER efficiency in MM cell lines and patient samples. Using next-generation sequencing data, we identified that expression of the canonical NER gene, excision repair cross-complementation group 3 (ERCC3), significantly impacted the outcome in newly diagnosed MM patients treated with alkylating agents. Next, using small RNA interference, stable knockdown and overexpression, and small-molecule inhibitors targeting xeroderma pigmentosum complementation group B (XPB), the DNA helicase encoded by ERCC3, we demonstrate that NER inhibition significantly increases sensitivity and overcomes resistance to alkylating agents in MM. Moreover, inhibiting XPB leads to the dual inhibition of NER and transcription and is particularly efficient in myeloma cells. Altogether, we show that NER impacts alkylating agents sensitivity in myeloma cells and identify ERCC3 as a potential therapeutic target in MM
miR-23b/SP1/c-myc forms a feed-forward loop supporting multiple myeloma cell growth
Deregulated microRNA (miR)/transcription factor (TF)-based networks represent a hallmark of cancer. We report here a novel c-Myc/miR-23b/Sp1 feed-forward loop with a critical role in multiple myeloma (MM) and Waldenstrom's macroglobulinemia (WM) cell growth and survival. We have found miR-23b to be downregulated in MM and WM cells especially in the presence of components of the tumor bone marrow milieu. Promoter methylation is one mechanism of miR-23b suppression in myeloma. In gain-of-function studies using miR-23b mimics-transfected or in miR-23b-stably expressing MM and WM cell lines, we observed a significant decrease in cell proliferation and survival, along with induction of caspase-3/7 activity over time, thus supporting a tumor suppressor role for miR-23b. At the molecular level, miR-23b targeted Sp1 3'UTR and significantly reduced Sp1-driven nuclear factor-kappa B activity. Finally, c-Myc, an important oncogenic transcription factor known to stimulate MM cell proliferation, transcriptionally repressed miR-23b. Thus MYC-dependent miR-23b repression in myeloma cells may promote activation of oncogenic Sp1-mediated signaling, representing the first feed-forward loop with critical growth and survival role in myeloma
A multiple myeloma classification system that associates normal B-cell subset phenotypes with prognosis.
Despite the recent progress in treatment of multiple myeloma (MM), it is still an incurable malignant disease, and we are therefore in need of new risk stratification tools that can help us to understand the disease and optimize therapy. Here we propose a new subtyping of myeloma plasma cells (PCs) from diagnostic samples, assigned by normal B-cell subset associated gene signatures (BAGS). For this purpose, we combined fluorescence-activated cell sorting and gene expression profiles from normal bone marrow (BM) Pre-BI, Pre-BII, immature, naïve, memory, and PC subsets to generate BAGS for assignment of normal BM subtypes in diagnostic samples. The impact of the subtypes was analyzed in 8 available data sets from 1772 patients' myeloma PC samples. The resulting tumor assignments in available clinical data sets exhibited similar BAGS subtype frequencies in 4 cohorts from de novo MM patients across 1296 individual cases. The BAGS subtypes were significantly associated with progression-free and overall survival in a meta-analysis of 916 patients from 3 prospective clinical trials. The major impact was observed within the Pre-BII and memory subtypes, which had a significantly inferior prognosis compared with other subtypes. A multiple Cox proportional hazard analysis documented that BAGS subtypes added significant, independent prognostic information to the translocations and cyclin D classification. BAGS subtype analysis of patient cases identified transcriptional differences, including a number of differentially spliced genes. We identified subtype differences in myeloma at diagnosis, with prognostic impact and predictive potential, supporting an acquired B-cell trait and phenotypic plasticity as a pathogenetic hallmark of MM
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