Human SCF R/c-Kit ELISA Kit

We retrospectively analyzed characteristics and outcomes of low-risk acute myeloid leukemia. The incidence rates of extramedullary infiltration, myeloid sarcoma, and central nervous system leukemia in this study were 24.76%, 20.56%, and 5.61%, respectively. Patients with extramedullary infiltration had worse 3-year relapse-free survival (67.0% +/- 6.6% vs. 86.9% +/- 2.9%; P = .000) and worse 3-year overall survival (76.1% +/- 6.2% vs. 87.8% +/- 2.8%; P=.026). Myeloid sarcoma was an independent risk factor for poor relapse-free survival (hazard ratio, 2.640; 95% confidence interval, 1.281-5.440; P = .008) and overall survival (hazard ratio, 2.079; 95% confidence interfal, 0.969-4.460; P = .049). Background: The impact of extramedullary infiltration (EMI) on the clinical outcomes of pediatric patients with acute myeloid leukemia (AML) are controversial. Patients and Methods: A total of 214 pediatric patients with low-risk AML were classified as having EMI (central nervous leukemia [CNSL] and/or myeloid sarcoma [MS]) and not having EMI. Patients with isolated MS before AML diagnosis by bone marrow examination were confirmed with histopathologic examination. For patients diagnosed with AML by bone marrow examination, a thorough physical examination and radiologic imaging were used to confirm MS. Results: Male gender, a high white blood cell count, the FAB-M5 subtype, t(8;21) and t(1;11) abnormalities, and c-KIT mutations were associated with EMI. The presence of MS was associated with a low complete remission rate (63.6% vs. 79.4%; P = .000) and poor 3-year relapse-free survival (RFS) (62.6% +/- 7.5% vs. 87.0% +/- 2.8%; P = .000) and 3-year overall survival (73.5% +/- 7% vs. 88.8% +/- 2.6%; P = .011). Multivariate analysis revealed that MS was a poor prognostic factor for RFS and overall survival. Bone infiltration was an independent risk factor for inferior RFS with MS. Patients with CNSL had a low complete remission rate (58.3% vs. 77.2%; P = .045); however, CNSL did not significantly affect the survival of low-risk patients with AML. Conclusion: MS should be considered an independent risk factor to guide stratified treatment. (C) 2020 Elsevier Inc. All rights reserved.

This article proposes doubly robust estimators for the average treatment effect on the treated (ATT) in difference-in-differences (DID) research designs. In contrast to alternative DID estimators, the proposed estimators are consistent if either (but not necessarily both) a propensity score or outcome regression working models are correctly specified. We also derive the semiparametric efficiency bound for the KIT in DID designs when either panel or repeated cross-section data are available, and show that our proposed estimators attain the semiparametric efficiency bound when the working models are correctly specified. Furthermore, we quantify the potential efficiency gains of having access to panel data instead of repeated cross-section data. Finally, by paying particular attention to the estimation method used to estimate the nuisance parameters, we show that one can sometimes construct doubly robust DID estimators for the ATT that are also doubly robust for inference. Simulation studies and an empirical application illustrate the desirable finite-sample performance of the proposed estimators. Open-source software for implementing the proposed policy evaluation tools is available. (C) 2020 Elsevier B.V. All rights reserved.