128 research outputs found

    Uniform Hazard Response Spectra of Korea Considering Uncertainties in Ground Properties

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    The seismic site coefficients derived deterministically are often used with ground motion parameters determined by probabilistic seismic hazard analysis in construction of the design response spectrum. There is, therefore, an inherent incompatibility between two approaches. New methods have been developed to resolve this incompatibility by developing probabilistic seismic site coefficients. In such approaches, the uncertainties in the properties of the ground were not systematically accounted for due to lack of measurements of the ground. In this study, an integrated probabilistic seismic hazard analysis which can quantify the nonlinear seismic site effects and account for the uncertainties in soil properties is developed and used to generate the uniform hazard response spectra in Korea. The procedure used an extensive database of measured shear wave velocity profiles and dynamic curves, which included more than 114 shear wave velocity profiles and more than 15 dynamic curves. The calculated uniform hazard response spectra were compared to the design spectra. Comparisons show significant discrepancy between two spectra, and highlight the need to revise the current design guideline

    The importance of critically short telomere in myelodysplastic syndrome

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    A few critically short telomeres trigger genomic instability regardless of average telomere length (TL). Recently, the telomere shortest length assay (TeSLA) was developed to detect critically short telomeres and measure absolute telomeres. Using TeSLA with the internally labeled biotin probe, we measured the TL of bone marrow (BM) aspirates from 52 patients with myelodysplastic syndrome (MDS). A percentage of shortest telomeres (<โ€‰1.0ย kb (ShTL1.0)) were calculated. ShTL1.0 was correlated to IPSS-R risk (spearmanโ€™s rhoโ€‰=โ€‰0.35 and pโ€‰=โ€‰0.0196), and ShTL1.0 and BM blast (2.61% inโ€‰<โ€‰5% blast, 4.15% in 5โ€“10% blast, and 6.80% in 10โ€“20% blast, respectively, pโ€‰=โ€‰0.0332). Interestingly, MDS patients with a shortest TLโ€‰โ‰ฅโ€‰0.787ย kb at the time of diagnosis showed better overall survival (OS) and progression-free survival (PFS) than patients with a shortest TLโ€‰<โ€‰0.787ย kb in the multivariate analyses (HRโ€‰=โ€‰0.13 and 0.30, pโ€‰=โ€‰0.011 and 0.048 for OS and PFS, respectively). Our results clearly show the presence and abundance of critically short telomeres in MDS patients. These pathologic telomeres are associated with IPSS-R which is a validated prognostic scoring system in MDS. Furthermore, they are independent prognostic factors for OS in MDS patients. Future prospective studies are needed to validate our results.Highlights Telomere length (TL) has been reported to be important in myelodysplastic syndrome (MDS).A novel TeSLA method demonstrated the presence and abundance of extremely short telomeres (<1.0kb) in MDS.Critically short TL rather than an average TL is associated with the IPSS-R and BM blast in MDS.The shortest TL is an independent prognostic factor for PFS and OS.Short TL should be incorporated into the risk scoring system in MDS in the future.This work was supported by the Ministry of Science and ICT(MSIT) of the Republic of Korea and the National Research Foundation of Korea (NRF-2020R1A3B3079653)

    Polymorphisms in Genes That Regulate Cyclosporine Metabolism Affect Cyclosporine Blood Levels and Clinical Outcomes in Patients Who Receive Allogeneic Hematopoietic Stem Cell Transplantation

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    In patients who received allogeneic hematopoietic stem cell transplantation (HSCT), we investigated the correlations between single nucleotide polymorphisms (SNPs) in genes that regulate cyclosporine metabolism and clinical outcomes. All patients received sibling-matched HSCT. DNA samples of patients and donors were analyzed for 4 SNPs: MDR1 +1236C>T (rs1128503), +2677G>T>A (rs2032582), +3435C>T (rs1045642), and CYP3A5 +6986G>A (rs776746). A total of 156 patients (median age 40ย years) were analyzed. Nineteen patients received HSCT for nonmalignant disease. The CYP3A5 +6986AA genotype was associated with a high cyclosporine blood level after transplantation. However, this genotype was not related to any particular clinical outcome. In contrast, the MDR1 +1236C>T SNP was correlated with specific clinical outcomes. When neither the donor nor the recipient had the CC genotype of MDR1 +1236, patients had lower creatinine levels (P < .001) and less transplantation-related mortality (TRM) (P = .012). These patients also showed longer overall survival (OS) in both univariate (P = .003) and multivariate (P = .003) analyses. Although the CYP3A5 +6986AA genotype was correlated with a high blood cyclosporine concentration, lack of the MDR1 +1236CC genotype in both the donor and recipient was correlated with less TRM and a longer OS in patients who received allogeneic HSCT

    Physioxia enhances T-cell development ex vivo from human hematopoietic stem and progenitor cells

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    Understanding physiologic T-cell development from hematopoietic stem (HSCs) and progenitor cells (HPCs) is essential for development of improved hematopoietic cell transplantation (HCT) and emerging T-cell therapies. Factors in the thymic niche, including Notch 1 receptor ligand, guide HSCs and HPCs through T-cell development in vitro. We report that physiologically relevant oxygen concentration (5% O2,physioxia), an important environmental thymic factor, promotes differentiation of cord blood CD34+ cells into progenitor T (proT) cells in serum-free and feeder-free culture system. This effect is enhanced by a potent reducing and antioxidant agent, ascorbic acid. Human CD34+ cell-derived proT cells in suspension cultures maturate into CD3+ T cells in an artificial thymic organoid (ATO) culture system more efficiently when maintained under physioxia, compared to ambient air. Low oxygen tension acts as a positive regulator of HSC commitment and HPC differentiation toward proT cells in the feeder-free culture system and for further maturation into T cells in the ATO. Culturing HSCs/HPCs in physioxia is an enhanced method of effective progenitor T and mature T-cell production ex vivo and may be of future use for HCT and T-cell immunotherapies

    Transcriptional signatures of the BCL2 family for individualized acute myeloid leukaemia treatment

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    Abstract Background Although anti-apoptotic proteins of the B-cell lymphoma-2 (BCL2) family have been utilized as therapeutic targets in acute myeloid leukaemia (AML), their complicated regulatory networks make individualized therapy difficult. This study aimed to discover the transcriptional signatures of BCL2 family genes that reflect regulatory dynamics, which can guide individualized therapeutic strategies. Methods From three AML RNA-seq cohorts (BeatAML, LeuceGene, and TCGA; n = 451, 437, and 179, respectively), we constructed the BCL2 family signatures (BFSigs) by applying an innovative gene-set selection method reflecting biological knowledge followed by non-negative matrix factorization (NMF). To demonstrate the significance of the BFSigs, we conducted modelling to predict response to BCL2 family inhibitors, clustering, and functional enrichment analysis. Cross-platform validity of BFSigs was also confirmed using NanoString technology in a separate cohort of 47 patients. Results We established BFSigs labeled as the BCL2, MCL1/BCL2, and BFL1/MCL1 signatures that identify key anti-apoptotic proteins. Unsupervised clustering based on BFSig information consistently classified AML patients into three robust subtypes across different AML cohorts, implying the existence of biological entities revealed by the BFSig approach. Interestingly, each subtype has distinct enrichment patterns of major cancer pathways, including MAPK and mTORC1, which propose subtype-specific combination treatment with apoptosis modulating drugs. The BFSig-based classifier also predicted response to venetoclax with remarkable performance (area under the ROC curve, AUROC = 0.874), which was well-validated in an independent cohort (AUROC = 0.950). Lastly, we successfully confirmed the validity of BFSigs using NanoString technology. Conclusions This study proposes BFSigs as a biomarker for the effective selection of apoptosis targeting treatments and cancer pathways to co-target in AML

    Toxic leukoencephalopathy with axonal spheroids caused by chemotherapeutic drugs other than methotrexate

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    Background The objective of this report is to share the clinicopathological features of chemotherapy-induced toxic leukoencephalopathy, which is a rare and under-recognized disease, clinically characterized by rapidly progressive cognitive loss that often leads to sudden death. Case presentation A 64-year-old woman and a 63-year-old man, who had both suffered from a rapid deterioration of consciousness, were autopsied under the clinical impressions of either the central nervous system graft versus host disease (CNS-GVHD), infectious encephalitis, or autoimmune encephalitis. Both patients had been treated with multiple chemotherapy regimens, including adriamycin, cytarabine arabinoside, daunorubicin, fludarabine, azacitidine, and allogeneic peripheral blood stem cell transplantation to treat hematological malignancies (acute myelogenous leukemia and myelodysplastic syndrome). Neuropathological findings at autopsy revealed rarefaction and vacuolar changes of the white matter with axonal spheroids, reactive gliosis, and foamy macrophage infiltration, predominantly in the visual pathways of the occipital and temporal lobes. Damaged axons exhibited immunoreactivity to beta-amyloid, consistent with axonopathy. However, there was no lymphocyte infiltration that suggested CNS-GVHD or any type of encephalitis. Conclusion The neuropathology found in the presented cases had the characteristic features of toxic leukoencephalopathy (chemobrain). Our cases showed that toxic leukoencephalopathy can also be caused by chemotherapy drugs other than methotrexate.This research was supported by a fund (2021-ER1001-01) by the Research of Korea Disease Control and Prevention Agency. The role of the funder is financial support for the operation of the brain bank of Seoul National University Hospital and the operation of the brain donation program for the research

    Risk factors for and clinical outcomes of carbapenem non-susceptible gram negative bacilli bacteremia in patients with acute myelogenous leukemia

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    Background Carbapenem is frequently used when gram negative bacilli (GNB) bacteremia is detected especially in neutropenic patients. Consequently, appropriate treatment could be delayed in GNB bacteremia cases involving organisms which are not susceptible to carbapenem (carba-NS), resulting in a poor clinical outcomes. Here, we explored risk factors for carba-NS GNB bacteremia and its clinical outcomes in patients with acute myelogenous leukemia (AML) that underwent chemotherapy. Methods We reviewed all GNB bacteremia cases that occurred during induction or consolidation chemotherapy, over a 15-year period, in a tertiary-care hospital. Results Among 489 GNB bacteremia cases from 324 patients, 45 (9.2%) were carba-NS and 444 (90.8%) were carbapenem susceptible GNB. Independent risk factors for carba-NS GNB bacteremia were: carbapenem use at bacteremia onset (adjusted odds ratio [aOR]: 91.2; 95% confidence interval [95%CI]: 29.3โ€“284.1; Pโ€‰<โ€‰0.001); isolation of carbapenem-resistant Acinetobacter baumannii (aOR: 19.4, 95%CI: 3.4โ€“112.5; Pโ€‰=โ€‰0.001) in the prior year; and days from chemotherapy to GNB bacteremia (aOR: 1.1 per day, 95%CI: 1.1โ€“1.2; Pโ€‰<โ€‰0.001). Carba-NS bacteremia was independently associated with in-hospital mortality (aOR: 6.6, 95%CI: 3.0โ€“14.8; Pโ€‰<โ€‰0.001). Conslusion Carba-NS organisms should be considered for antibiotic selection in AML patients having these risk factors

    Micafungin prophylaxis for acute leukemia patients undergoing induction chemotherapy

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    Background Micafungin is a well-tolerated and effective prophylactic antifungal agent used in hematologic diseases. In this prospective trial, we evaluated the efficacy and safety of prophylactic micafungin during first induction chemotherapy in patients with acute leukemia. We also compared outcomes of prophylactic micafungin with those of prophylactic posaconazole in acute myeloid leukemia (AML). Methods Medically fit patients with newly diagnosed acute leukemia received 50โ€‰mg micafungin intravenously once daily from the initiation of first induction chemotherapy to recovery of neutrophil count, suspected fungal infection, or unacceptable drug-related toxicity (Clinicaltrials.gov number, NCT02440178). The primary end point was incidence of invasive fungal infection, and the secondary end points were adverse events of prophylactic micafungin and mortality during induction therapy. Results The 65 patients (median ageโ€‰=โ€‰51โ€‰years, male:femaleโ€‰=โ€‰34:31) enrolled in this study had diagnoses of AML (33, 50.8%), acute lymphoblastic leukemia (31, 47.7%), and acute biphenotypic leukemia (1, 1.5%). Median duration of micafungin treatment was 24โ€‰days (range 1โ€“68), with proven invasive fungal disease in one patient (1.5%) and possible fungal infection in two patients (3.1%). Three of the patients (4.6%) experienced the following adverse events, but all events were tolerable: liver function abnormality (Grade 2, nโ€‰=โ€‰1; Grade 3, nโ€‰=โ€‰1) and allergic reaction (Grade 2, nโ€‰=โ€‰1). Three patients died during induction therapy, and invasive aspergillosis pneumonia was the cause of death for one of those patients. Overall, 19 patients (29.2%) discontinued prophylactic micafungin, and 18 (27.7%) patients switched to another antifungal agent. We observed no fungal infections caused by amphotericin B-resistant organisms. In AML patients, outcomes of prophylactic micafungin during induction chemotherapy did not differ significantly with those of prophylactic posaconazole with regard to incidence of fungal infections, rate of discontinuation, or safety. Conclusions Our study demonstrates that prophylactic micafungin is safe and effective in patients with acute leukemia undergoing induction chemotherapy. Outcomes in patients with AML were similar to those of prophylactic posaconazole, indicating the usefulness of micafungin as a prophylactic antifungal agent during induction chemotherapy for AML. Trial registration Clinicaltrials.gov NCT02440178, registered May 12th 2015.This study was funded by Astellas Pharma Korea, Inc. Funding source had no role in the study design, data collection, data analysis or data interpretation

    Strong association between herpes simplex virus-1 and chemotherapy-induced oral mucositis in patients with hematologic malignancies

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    Background/Aims: A link between oral cavity infections and chemotherapy-induced oral mucositis (CIOM) in patients with hematological malignancies (HMs) undergoing intensive chemotherapy (IC) or hematopoietic stem cell transplantation (HSCT) has been suggested. However, conclusive data are lacking, and there are no current guidelines for the prophylactic use of antimicrobials to prevent CIOM in these populations. Methods: The relationships between herpes simplex virus (HSV) reactivation and Candida colonization in the oral cavity and CIOM in patients with HMs undergoing IC or HSCT were evaluated. Patients aged &gt;= 19 years with HMs undergoing IC or HSCT were enrolled. Each patient was evaluated for HSV and Candida in the oral cavity along with CIOM at baseline and during the and, 3rd, and 4th weeks. Results: Seventy presentations among 56 patients were analyzed. CIOM was observed in 23 presentations (32.9%), with a higher incidence associated with HSCT (17 of 35 presentations, 48.6%) than with IC (six of 35 presentations, 8.6%). The reactivation of HSV-1 was significantly associated with an increased incidence of CIOM after adjusting for age, sex, type of disease, and treatment stage. A higher HSV-1 viral load was associated with an increased incidence of CIOM. The presence of Candida was not associated with CIOM. Conclusions: HSV-1 reactivation in the oral cavity was highly associated with CIOM in patients with HMs undergoing high-dose chemotherapy.Y
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