Search

The decay of space charge in conjugated polymers due to detrapping from deep traps after the turn-off of an external bias has been investigated. We present an experiment for measuring time-resolved laser intensity modulation method spectrum with a resolution of about 1 s. For this pyroelectric current transients have been recorded at different temperatures from 220 to 360 K. The data have been analyzed, assuming detrapping of charge carriers from single energy trap levels to a Gaussian distribution of transport levels to be the predominating process of the space-charge decay. In poly[2-methoxy, 5-(2'-ethyl-hexyloxy)-p-phenylene-vinylene], we find hole trapping with a trap depth of E[sub t]=0.6eV and a trap density N[sub t]>2 × 10[sup 21]m[sup -3]. In poly(2,5-pyridinediyl) both electron and hole trapping are observed, and the analysis of the decays yield E[sup t] = 0.55 eV and N[sub t] > 10[sup 21] m[sup -3]. No deep trapping could be observed in poly(9,9-dioctylfluorene), confirming the high chemical purity of this polymer. [ABSTRACT FROM AUTHOR]

Temperature dependent pyroelectric measurements have been carried out on high barrier devices of conjugated polymers. At room temperature we find significant buildup of space charge at the metal/polymer interface as well as in the bulk despite the very low device current. At lower temperature (180 K) the charge profile is "frozen in" and shows nearly no bias dependence, while above room temperature the space charge seems to become more mobile and leads to broadening of the charge profile. By applying an injection model that accounts for charge backflow via interface recombination we demonstrate that the high amount of space charge detected in our films indicates the existence of deep traps in the surface region that can effectively collect charge from the electrode. In the bulk of the film we find space charge of different sign, which is assumed to be due to separation in the field of charge from intrinsic defect states. These bulk charges are also immobile at low temperatures, indicating that they correspond to electrons or holes that are transported by hopping or tunneling between traps. [ABSTRACT FROM AUTHOR]

Targeted protein degradation (TPD) represents a promising alternative to conventional occupancy-driven protein inhibition. Despite the existence of more than 600 E3 ligases in the human proteome, so far only a few have been utilized for TPD of histone deacetylases (HDACs), which represent important epigenetic anticancer drug targets. In this study, we disclose the first-in-class Fem-1 homologue B (FEM1B)-recruiting HDAC degraders. A set of 12 proteolysis targeting chimeras (PROTACs) was synthesized using a solid-phase supported parallel synthesis approach utilizing a covalent FEM1B ligand as an E3 ligase warhead. The evaluation of the HDAC degradation efficiency revealed substantial HDAC1 degradation by the top-performing degrader FF2049 ( 1g : D max = 85%; DC 50 = 257 nM). Unlike our previously published cereblon-recruiting selective HDAC6 degrader, A6 , which uses the same HDAC ligand, the FEM1B-based PROTACs achieved selective HDAC1-3 degradation. This unexpected change in the HDAC isoform degradation profile was accompanied by significant enhancement of the antiproliferative properties.

Background: Cytomegalovirus (CMV) disease causes significant morbidity among solid organ transplant (SOT) recipients. To prevent CMV disease, eligible recipients are frequently started on valganciclovir (VGC) prophylaxis post-transplant. Leukopenia has been documented as a primary adverse events of the drug (1). This study's primary aim was to determine whether a patient's weight at the start of VGC prophylaxis was associated with the development of leukopenia., Methods: This was a single center, retrospective cohort study that included adults > 18 years of age, who had received an organ transplant (heart, liver, or lung) at an academic transplant center from January 1, 2018 through December 31, 2022. A creatinine clearance of > 60 mL/min was required., Results: All 294 included patients received 900 mg/day of VGC for CMV prophylaxis, without dose adjustment. Fifty-two percent of the patients developed leukopenia while receiving VGC prophylaxis. The mean weight at initiation of VGC was higher in patients who did not develop leukopenia (97.9 kg) compared to those who did (90.7 kg; p = 0.0112). It was found that with each 1 kg increase in body weight, the likelihood of developing leukopenia decreased by 1.7% (p = 0.004, odds ratio = 0.983, 95% confidence interval [CI], 0.972-0.994). Patients with a baseline body-mass index (BMI) > 25 had a longer median freedom time from leukopenia after initiation of VGC as compared to the group with baseline BMI < 25 (log-rank p = 0.035)., Conclusion: These data suggest that in SOT recipients with normal renal function, receiving a fixed dose of VGC resulted in a significant, inverse relationship between body weight and the development of leukopenia., (© 2024 The Author(s). Transplant Infectious Disease published by Wiley Periodicals LLC.)

Most cancers and neoplastic progenitor cells have elevated telomerase activity and preservation of telomeres that promote cellular immortality, making telomerase a rational target for the treatment of cancer. Imetelstat is a first-in-class, 13-mer oligonucleotide that binds with high affinity to the template region of the RNA component of human telomerase and acts as a competitive inhibitor of human telomerase enzymatic activity. Pharmacokinetics, pharmacodynamics, exposure-response analyses, efficacy, and safety of imetelstat have been evaluated in vitro, in vivo, and clinically in solid tumor and hematologic malignancies, including lower-risk myelodysplastic syndromes (LR-MDS) and myeloproliferative neoplasms. Imetelstat was approved in the United States in June 2024 for the treatment of adult patients with LR-MDS with transfusion-dependent anemia requiring four or more red blood cell units over 8 weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents, with a recommended dosing regimen of 7.1 mg/kg administered via 2-h intravenous infusion every 4 weeks. In the pivotal trial, significantly more patients treated with imetelstat versus placebo achieved ≥8-week and ≥24-week red blood cell-transfusion independence, and imetelstat was associated with a manageable safety profile characterized primarily by short-lived and manageable neutropenia and thrombocytopenia. This mini-review summarizes the mechanism of action, pharmacokinetic and pharmacodynamic characteristics, clinical development, and clinical efficacy and safety data of imetelstat., (© 2024 Geron Corporation. Clinical and Translational Science published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Our previously reported HDAC6 inhibitor (HDAC6i) Marbostat-100 (4) has provided many arguments for further clinical evaluation. By the substitution of the acidic hydrogen of 4 for different carbon residues, we were able to generate an all-carbon stereocenter, which significantly improves the hydrolytic stability of the inhibitor. Further asymmetric synthesis has shown that the (S)-configured inhibitors preferentially bind to HDAC6. This led to the highly selective and potent methyl-substituted derivative S-29b, which elicited a long-lasting tubulin hyperacetylation in MV4-11 cells. Finally, a crystal structure of the HDAC6/S-29b complex provided mechanistic explanation for the high potency and stereoselectivity of synthesized compound series., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: The incidence of atypical pneumonia among immunocompromised patients is not well characterized. Establishing a diagnosis of atypical pneumonia is challenging as positive tests must be carefully interpreted. We aimed to assess the test positivity rate and incidence of atypical pneumonia in transplant recipients., Methods: A retrospective cohort study was conducted at the Yale New Haven Health System in Connecticut. Adults with solid organ transplant, hematopoietic stem cell transplant (HSCT), or chimeric antigen receptor T-cell, who underwent testing for atypical pathogens of pneumonia (Legionella pneumophilia, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Bordetella pertussis) between January 2016 and August 2022 were included. Positive results were adjudicated in a clinical context using pre-defined criteria. A cost analysis of diagnostic testing was performed., Results: Note that, 1021 unique tests for atypical pathogens of pneumonia were performed among 481 transplant recipients. The testing positivity rate was 0.7% (n = 7). After clinical adjudication, there were three cases of proven Legionella and one case of possible Mycoplasma infection. All cases of legionellosis were in transplant recipients within 1-year post-transplantation with recently augmented immunosuppression and lymphopenia. The possible case of Mycoplasma infection was in an HSCT recipient with augmented immunosuppression. The cost of all tests ordered was $50,797.73., Conclusion: The positivity rate of tests for atypical pneumonia was very low in this transplant cohort. An algorithmic approach that targets testing for those with compatible host, clinical, radiographic, and epidemiologic factors, and provides guidance on test selection and test interpretation, may improve the diagnostic yield and lead to substantial cost savings., (© 2024 The Authors. Transplant Infectious Disease published by Wiley Periodicals LLC.)

Imetelstat is a novel, first-in-class, oligonucleotide telomerase inhibitor in development for the treatment of hematologic malignancies including lower-risk myelodysplastic syndromes and myelofibrosis. A nonlinear mixed-effects model was developed to characterize the population pharmacokinetics of imetelstat and identify and quantify covariates that contribute to its pharmacokinetic variability. The model was developed using plasma concentrations from 7 clinical studies including 424 patients with solid tumors or hematologic malignancies who received single-agent imetelstat via intravenous infusion at various dose levels (0.4-11.7 mg/kg) and schedules (every week to every 4 weeks). Covariate analysis included factors related to demographics, disease, laboratory results, renal and hepatic function, and antidrug antibodies. Imetelstat was described by a two-compartment, nonlinear disposition model with saturable binding/distribution and dose- and time-dependent elimination from the central compartment. Theory-based allometric scaling for body weight was included in disposition parameters. The final covariates included sex, time, malignancy, and dose on clearance; malignancy and sex on volume of the central compartment; and malignancy and spleen volume on concentration of target. Clearance in females was modestly lower, resulting in nonclinically relevant increases in predicted exposure relative to males. No effects on imetelstat pharmacokinetics were identified for mild-to-moderate hepatic or renal impairment, age, race, and antidrug antibody status. All model parameters were estimated with adequate precision (relative standard error < 29%). Visual predictive checks confirmed the capacity of the model to describe the data. The analysis supports the imetelstat body-weight-based dosing approach and lack of need for dose individualizations for imetelstat-treated patients., (© 2024 Geron Corporation. CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Background: Unmet medical needs remain in patients with red blood cell transfusion-dependent (RBC-TD) lower-risk myelodysplastic syndromes (LR-MDS) who are not responding to or are ineligible for erythropoiesis-stimulating agents (ESAs). Imetelstat, a competitive telomerase inhibitor, showed promising results in a phase 2 trial. We aimed to compare the RBC transfusion independence (RBC-TI) rate with imetelstat versus placebo in patients with RBC-TD LR-MDS., Methods: In phase 3 of IMerge, a double-blind, placebo-controlled trial conducted in 118 sites including university hospitals, cancer centres, and outpatient clinics in 17 countries, patients (aged ≥18 years) with ESA-relapsed, ESA-refractory, or ESA-ineligible LR-MDS (low or intermediate-1 risk disease as per International Prognostic Scoring System [IPSS] criteria) were randomly assigned via a computer-generated schedule (2:1) to receive imetelstat 7·5 mg/kg or placebo, administered as a 2-h intravenous infusion, every 4 weeks until disease progression, unacceptable toxic effects, or withdrawal of consent. Randomisation was stratified by previous RBC transfusion burden and IPSS risk group. Patients, investigators, and those analysing the data were masked to group assignment. The primary endpoint was 8-week RBC-TI, defined as the proportion of patients without RBC transfusions for at least 8 consecutive weeks starting on the day of randomisation until subsequent anti-cancer therapy, if any. Primary efficacy analyses were performed in the intention-to-treat population, and safety analyses were conducted in patients who received at least one dose of trial medication or placebo. This trial is registered with ClinicalTrials.gov (NCT02598661; substudy active and recruiting)., Findings: Between Sept 11, 2019, and Oct 13, 2021, 178 patients were enrolled and randomly assigned (118 to imetelstat and 60 to placebo). 111 (62%) were male and 67 (38%) were female. 91 (77%) of 118 patients had discontinued treatment by data cutoff in the imetelstat group versus 45 (75%) in the placebo group; a further one patient in the placebo group did not receive treatment. Median follow-up was 19·5 months (IQR 12·0-23·4) in the imetelstat group and 17·5 months (12·1-22·7) in the placebo group. In the imetelstat group, 47 (40% [95% CI 30·9-49·3]) patients had an RBC-TI of at least 8 weeks versus nine (15% [7·1-26·6]) in the placebo group (rate difference 25% [9·9 to 36·9]; p=0·0008). Overall, 107 (91%) of 118 patients receiving imetelstat and 28 (47%) of 59 patients receiving placebo had grade 3-4 treatment-emergent adverse events. The most common treatment-emergent grade 3-4 adverse events in patients taking imetelstat were neutropenia (80 [68%] patients who received imetelstat vs two [3%] who received placebo) and thrombocytopenia (73 [62%] vs five [8%]). No treatment-related deaths were reported., Interpretation: Imetelstat offers a novel mechanism of action with durable transfusion independence (approximately 1 year) and disease-modifying activity for heavily transfused patients with LR-MDS who are not responding to or are ineligible for ESAs., Funding: Janssen Research & Development before April 18, 2019, and Geron Corporation thereafter., Competing Interests: Declaration of interests UP received honoraria consultancy fees and research funding from Geron Corporation, BMS/Celgene, AbbVie, Jazz, Janssen, Syros, Servier, Silence Therapeutics, and Takeda. VS served on advisory boards with AbbVie, CTI, Geron Corporation, Gilead, BMS/Celgene, Novartis, Otsuka, Servier, and Syros, and received a travel grant from Janssen. PF received consultancy fees, research funding, and honoraria from BMS/Celgene, and honoraria and research funding from Celgene. MAS received advisory board fees from Geron Corporation, BMS/Celgene, Novartis, and Kurome. MRS received research funding from ALX Oncology, Astex, Incyte, Takeda, and TG Therapeutics; consults or serves on advisory or data safety monitoring boards for AbbVie, BMS/Celgene, Forma, Geron Corporation, Karyopharm, Novartis, Ryvu, Sierra Oncology, Taiho, Takeda, and TG Therapeutics; and has equity in Karyopharm and Ryvu. YFM received honoraria or consulting fees from Blueprint Medicines, Geron Corporation, and OncLive; participated in advisory boards and received honoraria from Sierra Oncology, Stemline Therapeutics, Blueprint Medicines, Morphosys, Taiho Oncology, and Novartis; and received travel reimbursement from Blueprint Medicines and Morphosys. MD-C consulted or participated in an advisory role with BMS/Celgene, Novartis, GlaxoSmithKline, and Blueprint Medicines; received travel and accommodation expenses from Gilead Sciences; and received honoraria from BMS/Celgene and Novartis. DV consulted or participated in an advisory role with BMS/Celgene, Amgen, GlaxoSmithKline, Novartis, Takeda, Pfizer, BMS/Celgene, Sanofi, Jazz Pharmaceuticals, and SOBI; participated in speakers' bureau at Agios, Novartis, Amgen, GlaxoSmithKline, Astellas Pharma, Pfizer, Jazz Pharmaceuticals, Sanofi/Aventis, BMS/Celgene, Astellas Pharma, Kyte, and Gebro Pharma; and received travel, accommodations, and expenses from BMS/Celgene, Amgen, Pfizer, GlaxoSmithKline, and Jazz Pharmaceuticals. TI consulted or participated in an advisory role at Novartis, AstraZeneca, and AbbVie. AJ consulted or participated in an advisory role at AbbVie, BMS/Celgene, and Novartis; and received travel, accommodations, and expenses from AbbVie and BMS/Celgene. RSK participated on a speaker bureau with Jazz, Servier, AbbVie, CTI, and PharmaEssentia; received advisory board fees or honoraria from BMS/Celgene, Novartis, AbbVie, Jazz, Servier, PharmaEssentia, Taiho, Takeda, Geron Corporation, Gilead/Forty Seven, and CTI; received travel, accommodations, expenses from Jazz, BMS/Celgene, and PharmaEssentia; has stock and other ownership interests in AbbVie; and received research funding from BMS/Celgene. AMZ received research funding (institutional) from BMS/Celgene, AbbVie, Astex, Pfizer, Kura, Medimmune/AstraZeneca, Boehringer Ingelheim, Incyte, Takeda, Novartis, Shattuck Labs, Geron Corporation, Foran, and Aprea; participated in advisory boards, had a consultancy with, or received honoraria from AbbVie, Pfizer, BMS/Celgene, Jazz, Incyte, Agios, Servier, Boehringer Ingelheim, Novartis, Astellas, Daiichi Sankyo, Geron Corporation, Taiho, Seattle Genetics, BeyondSpring, Takeda, Ionis, Amgen, Janssen, Genentech, Epizyme, Syndax, Gilead, Kura, Chiesi, ALX Oncology, BioCryst, Notable, Orum, Mendus, Zentalis, Schrodinger, Regeneron, Syros, Schrodinger, and Tyme; and served on clinical trial committees for Novartis, AbbVie, Gilead, Syros, BioCryst, ALX Oncology, Kura, Geron Corporation, and BMS/Celgene. LS, TB, SD, SS, QX, LJS, YW, FH, AI, SN, and FF are employees of Geron Corporation. PB declares no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

There is a growing interest in alternative strategies for targeted protein degradation. In this work, we present the development of histone deacetylase (HDAC) degraders based on hydrophobic tagging technology. To this end, a library of hydrophobically tagged HDAC inhibitors was synthesized via efficient solid-phase protocols utilizing pre-loaded resins. The subsequent biological evaluation led to the identification of our best degrader, 1a , which significantly decreased HDAC1 levels in MM.1S multiple myeloma cells., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Immunomodulatory imide drugs (IMiDs) such as thalidomide, pomalidomide, and lenalidomide are the most common cereblon (CRBN) recruiters in proteolysis-targeting chimera (PROTAC) design. However, these CRBN ligands induce the degradation of IMiD neosubstrates and are inherently unstable, degrading hydrolytically under moderate conditions. In this work, we simultaneously optimized physiochemical properties, stability, on-target affinity, and off-target neosubstrate modulation features to develop novel nonphthalimide CRBN binders. These efforts led to the discovery of conformationally locked benzamide-type derivatives that replicate the interactions of the natural CRBN degron, exhibit enhanced chemical stability, and display a favorable selectivity profile in terms of neosubstrate recruitment. The utility of the most potent ligands was demonstrated by their transformation into potent degraders of BRD4 and HDAC6 that outperform previously described reference PROTACs. Together with their significantly decreased neomorphic ligase activity on IKZF1/3 and SALL4, these ligands provide opportunities for the design of highly selective and potent chemically inert proximity-inducing compounds.

Histone deacetylases (HDACs) play a key role in the control of transcription, cell proliferation, and migration. FDA-approved histone deacetylase inhibitors (HDACi) demonstrate clinical efficacy in the treatment of different T-cell lymphomas and multiple myeloma. However, due to unselective inhibition, they display a wide range of adverse effects. One approach to avoiding off-target effects is the use of prodrugs enabling a controlled release of the inhibitor in the target tissue. Herein, we describe the synthesis and biological evaluation of HDACi prodrugs with photo-cleavable protecting groups masking the zinc-binding group of the established HDACi DDK137 ( I ) and VK1 ( II ). Initial decaging experiments confirmed that the photocaged HDACi pc-I could be deprotected to its parent inhibitor I . In HDAC inhibition assays, pc-I displayed only low inhibitory activity against HDAC1 and HDAC6. After irradiation with light, the inhibitory activity of pc-I strongly increased. Subsequent MTT viability assays, whole-cell HDAC inhibition assays, and immunoblot analysis confirmed the inactivity of pc-I at the cellular level. Upon irradiation, pc-I demonstrated pronounced HDAC inhibitory and antiproliferative activities which were comparable to the parent inhibitor I . Additionally, only phototreated pc-I was able to induce apoptosis in Annexin V/PI and caspase-Glo 3/7 assays, making pc-I a valuable tool for the development of light-activatable HDACi.

Multi-target drugs (MTDs) are emerging alternatives to combination therapies. Since both histone deacetylases (HDACs) and cyclooxygenase-2 (COX-2) are known to be overexpressed in several cancer types, we herein report the design, synthesis, and biological evaluation of a library of dual HDAC-COX inhibitors. The designed compounds were synthesized via an efficient parallel synthesis approach using preloaded solid-phase resins. Biological in vitro assays demonstrated that several of the synthesized compounds possess pronounced inhibitory activities against HDAC and COX isoforms. The membrane permeability and inhibition of cellular HDAC activity of selected compounds were confirmed by whole-cell HDAC inhibition assays and immunoblot experiments. The most promising dual inhibitors, C3 and C4 , evoked antiproliferative effects in the low micromolar concentration range and caused a significant increase in apoptotic cells. In contrast to previous reports, the simultaneous inhibition of HDAC and COX activity by dual HDAC-COX inhibitors or combination treatments with vorinostat and celecoxib did not result in additive or synergistic anticancer activities.

Acute myeloid leukemia (AML) is characterized by poor clinical outcomes due to high rates of relapse following standard-of-care induction chemotherapy. While many pathogenic drivers have been described in AML, our understanding of the molecular mechanisms mediating chemotherapy resistance remains poor. Therefore, we sought to identify resistance genes to induction therapy in AML and elucidated ALOX5 as a novel mediator of resistance to anthracycline-based therapy. ALOX5 is transcriptionally upregulated in AML patient blasts in comparison to normal hematopoietic stem/progenitor cells (HSPCs) and ALOX5 mRNA, and protein expression is increased in response to induction therapy. In vitro, and in vivo genetic, and pharmacologic perturbation studies confirm that ALOX5 positively regulates the leukemogenic potential of AML LSCs, and its loss does not significantly affect the function of normal HSPCs. ALOX5 mediates resistance to daunorubicin (DNR) and promotes AML cell survival and maintenance through its leukotriene (LT) synthetic capacity, specifically via modulating the synthesis of LTB4 and its binding to LTB receptor (BLTR). Our study reveals a previously unrecognized role of LTs in AML pathogenesis and chemoresistance, whereby inhibition of ALOX5 mediated LTB4 synthesis and function could be combined with standard chemotherapy, to enhance the overall therapeutic efficacy in AML., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

In the MYF2001 trial, treatment of Janus kinase (JAK) inhibitor-relapsed/refractory intermediate-2 or high-risk myelofibrosis (MF) with imetelstat 9.4 mg/kg every 3 weeks demonstrated encouraging median overall survival of 29.9 months. To provide historical context, external real-world data (RWD) were collected from a study of 96 patients who had discontinued ruxolitinib and were subsequently treated with best available therapy (BAT) at Moffitt Cancer Center. A closely matched cohort was identified using the MYF2001 eligibility criteria, including patients with MF who had discontinued ruxolitinib due to lack or loss of response. Overall survival was measured from time of JAK inhibitor discontinuation to death or censored at last follow-up. To improve comparability, propensity score weighting approaches using average treatment effect for overlap population (ATO) and stabilized inverse probability treatment weighting (sIPTW) were used for 10 critical baseline covariates. Fifty-seven patients treated with imetelstat 9.4 mg/kg from MYF2001 and 38 patients treated with BAT from RWD were analyzed with improved balanced baseline covariates after propensity score adjustment, showing significantly lower risk of death with imetelstat compared with BAT (hazard ratio: 0.35; p = 0.0019). With sIPTW, results were similar. Results of sensitivity analyses were consistent with the primary analysis. In conclusion, treatment with imetelstat was associated with longer overall survival compared to BAT (30 vs 12 months, respectively) in closely matched patients with MF after JAK inhibitor failure, warranting further evaluation of imetelstat in this poor-prognosis patient population., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Herein, we report a case of a 68-year-old woman receiving ibrutinib for chronic lymphocytic leukaemia, who presented with septic shock and a progressive necrotic lesion on her nose. Surgical pathology of the nasal lesion revealed evidence of tissue necrosis, and both tissue and blood culture grew Pseudomonas aeruginosa A diagnosis of ecthyma gangrenosum was made. Additional investigations also led to the discovery of invasive pulmonary aspergillosis. To our knowledge, this is the first case of ecthyma gangrenosum secondary to Pseudomonas sepsis and concurrent invasive pulmonary aspergillosis associated with ibrutinib use., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: Patients with lower-risk (LR) myelodysplastic syndromes (MDS) who are RBC transfusion dependent and have experienced relapse after or are refractory to erythropoiesis-stimulating agent (ESA) have limited treatment options. High telomerase activity and human telomerase reverse-transcription expression in clonal hematopoietic cells have been reported in patients with MDS. Imetelstat, a first-in-class competitive inhibitor of telomerase enzymatic activity, targets cells with active telomerase. We report efficacy, safety, and biomarker data for patients with LR MDS who are RBC transfusion dependent and who were relapsed/refractory to ESAs., Patients and Methods: In this two-part phase II/III study (MDS3001), the primary end point was 8-week RBC transfusion independence (TI) rate, with key secondary end points of 24-week RBC TI rate, TI duration, and hematologic improvement-erythroid., Results: Data from the phase II part of the study are reported. Of 57 patients enrolled and treated (overall population), 38 were non-del(5q) and hypomethylating agent and lenalidomide naïve (subset population). The 8- and 24-week RBC TI rates in the overall population were 37% and 23%, respectively, with a median TI duration of 65 weeks. In the subset population, 8- and 24-week RBC TI rates were 42% and 29%, respectively, with a median TI duration of 86 weeks. Eight-week TI rate was observed across all subgroups evaluated. Cytogenetic and mutational data revealed a reduction of the malignant clones, suggesting disease modification activity. The most common adverse events were cytopenias, typically reversible within 4 weeks., Conclusion: Imetelstat treatment results in a meaningful, durable TI rate across a broad range of heavily transfused patients with LR MDS who are ineligible for or relapsed/refractory to ESAs. Biomarker analyses indicated effects on the mutant malignant clone.

In an effort to meet the changing landscape of the health care system and the explosion of nursing knowledge, the Institute of Medicine and the Robert Wood Johnston Foundation have summoned nursing academia to partner on curriculum development with an emphasis on the professional socialization of the new nurse. As health care continues to change, the education of nurses must also evolve to meet these changes. Curriculum transformation is needed at nearly every aspect of health care. This policy statement will explore these challenges and the transformation in nursing education required to meet them.

Because Th17-polarized airway inflammation correlates with poor control in bronchial asthma and is a feature of numerous other difficult-to-treat inflammatory lung diseases, new therapeutic approaches for this type of airway inflammation are necessary. We assessed different licensed anti-inflammatory agents with known or expected efficacy against Th17-polarization in mouse models of Th17-dependent airway inflammation. Upon intravenous transfer of in vitro derived Th17 cells and intranasal challenge with the corresponding antigen, we established acute and chronic murine models of Th17-polarised airway inflammation. Consecutively, we assessed the efficacy of methylprednisolone, roflumilast, azithromycin, AM80 and rapamycin against acute or chronic Th17-dependent airway inflammation. Quantifiers for Th17-associated inflammation comprised: bronchoalveolar lavage (BAL) differential cell counts, allergen-specific cytokine and immunoglobulin secretion, as well as flow cytometric phenotyping of pulmonary inflammatory cells. Only rapamycin proved effective against acute Th17-dependent airway inflammation, accompanied by increased plasmacytoid dendritic cells (pDCs) and reduced neutrophils as well as reduced CXCL-1 levels in BAL. Chronic Th17-dependent airway inflammation was unaltered by rapamycin treatment. None of the other agents showed efficacy in our models. Our results demonstrate that Th17-dependent airway inflammation is difficult to treat with known agents. However, we identify rapamycin as an agent with inhibitory potential against acute Th17-polarized airway inflammation.

Drug-induced thrombocytopenia often results from dysregulation of normal megakaryocytopoiesis. In this study, we investigated the mechanisms responsible for thrombocytopenia associated with the use of Panobinostat (LBH589), a histone deacetylase inhibitor with promising anti-cancer activities. The effects of LBH589 were tested on the cellular and molecular aspects of megakaryocytopoiesis by utilizing an ex vivo system in which mature megakaryocytes (MK) and platelets were generated from human primary CD34(+) cells. We demonstrated that LBH589 did not affect MK proliferation or lineage commitment but inhibited MK maturation and platelet formation. Although LBH589 treatment of primary MK resulted in hyperacetylation of histones, it did not interfere with the expression of genes that play important roles during megakaryocytopoiesis. Instead, we found that LBH589 induced post-translational modifications of tubulin, a nonhistone protein that is the major component of the microtubule cytoskeleton. We then demonstrated that LBH589 treatment induced hyperacetylation of tubulin and alteration of microtubule dynamics and organization required for proper MK maturation and platelet formation. This study provides new insights into the mechanisms underlying LBH589-induced thrombocytopenia and provides a rationale for using tubulin as a target for selective histone deacetylase inhibitor therapies to treat thrombocytosis in patients with myeloproliferative neoplasms., (Copyright © 2012 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.)

Unlabelled: Basic Local Alignment Search Tool, (BLAST) allows the comparison of a query sequence/s to a database of sequences and identifies those sequences that are similar to the query above a user-defined threshold. We have developed a user friendly web application, MULTBLAST that runs a series of BLAST searches on a user-supplied list of proteins against one or more target protein or nucleotide databases. The application pre-processes the data, launches each individual BLAST search on the University of Nevada, Reno's-TimeLogic DeCypher® system (available from Active Motif, Inc.) and retrieves and combines all the results into a simple, easy to read output file. The output file presents the list of the query proteins, followed by the BLAST results for the matching sequences from each target database in consecutive columns. This format is especially useful for either comparing the results from the different target databases, or analyzing the results while keeping the identification of each target database separate., Availability: The application is available at the URLhttp://blastpipe.biochem.unr.edu/

In the filamentous ascomycete Podospora anserina a 6,935-bp retrotransposon, Yeti, has been identified and characterized. It is flanked by a 5-bp target site duplication and contains long terminal repeats (LTRs) 354 bp in length. The LTRs show a high degree of identity to the previously reported repetitive element repa, a sequence suggested to represent a solo-LTR element of an unknown transposon. In the investigated Podospora strains, the number of complete Yeti copies is significantly lower than the number of repa elements, with up to 25 copies. Yeti appears to be inactive: it is highly degenerate and no transcripts of the element have been detected even in Podospora cultures grown under elevated stress conditions. The amino acid sequences deduced from Yeti display significant homology, particularly in the reverse transcriptase region, to those of other fungal retrotransposons, indicating that it is a member of the gypsy family. As suggested by the unusual dinucleotide content, degeneration of Yeti appears to be the result of a molecular mechanism resembling repeat-induced point mutation in Neurospora crassa.