129 research outputs found
Autologous/Allogeneic Hematopoietic Cell Transplantation versus Tandem Autologous Transplantation for Multiple Myeloma: Comparison of Long-Term Postrelapse Survival
We compared postrelapse overall survival (OS) after autologous/allogeneic (auto/allo) versus tandem autologous (auto/auto) hematopoietic cell transplantation (HCT) in patients with multiple myeloma (MM). Postrelapse survival of patients receiving an auto/auto or auto/allo HCT for MM and prospectively reported to the Center for International Blood and Marrow Transplant Research between 2000 and 2010 were analyzed. Relapse occurred in 404 patients (72.4%) in the auto/auto group and in 178 patients (67.4%) in the auto/allo group after a median follow-up of 8.5 years. Relapse occurred before 6 months after a second HCT in 46% of the auto/allo patients, compared with 26% of the auto/auto patients. The 6-year postrelapse survival was better in the auto/allo group compared with the auto/auto group (44% versus 35%; P = .05). Mortality due to MM was 69% (n = 101) in the auto/allo group and 83% (n = 229) deaths in auto/auto group. In multivariate analysis, both cohorts had a similar risk of death in the first year after relapse (hazard ratio [HR], .72; P = .12); however, for time points beyond 12 months after relapse, overall survival was superior in the auto/allo cohort (HR for death in auto/auto =1.55; P = .005). Other factors associated with superior survival were enrollment in a clinical trial for HCT, male sex, and use of novel agents at induction before HCT. Our findings shown superior survival afterrelapse in auto/allo HCT recipients compared with auto/auto HCT recipients. This likely reflects a better response to salvage therapy, such as immunomodulatory drugs, potentiated by a donor-derived immunologic milieu. Further augmentation of the post-allo-HCT immune system with new immunotherapies, such as monoclonal antibodies, checkpoint inhibitors, and others, merit investigation
A data-driven approach for exploiting enzyme promiscuity as a means to predict novel biochemical reactions
Systems metabolic engineering has been widely used to produce chemicals of high commercial value from low cost substrates. But this process has challenges for some applications, such as harnessing lignocellulosic biomass for biofuel and biochemical production, due to our limited metabolic knowledgebase. With current advances in protein engineering, it is possible to exploit substrate promiscuity of enzymes to enable novel biochemical reactions. Nevertheless, performing experiments to determine what substrates an enzyme can act on can be time consuming and it is not always clear what potential substrates to test. So, the current work aims to employ machine learning approaches for identifying novel substrates and in turn, predicting novel reactions that are more promising than the putative reactions predicted simply based on compound similarity measures (e.g., Tanimoto coefficient). A highly accurate (up to 88.3%) machine learning model was developed to identify candidate substrates for alcohol dehydrogenase (ADH) using a dataset consisting of 23 metabolites (with 8 of them being known positives) and 46 chemo-informatics based molecular descriptors (e.g., topology, stereochemistry, and electronic features). In addition, support vector regression proved to be a useful method for estimating enzyme kinetics (characterized by Michaelis-Menten constants, Km and Vmax) for a variety of oxidoreductases that are typically found in biofuel biosynthesis pathways. Such machine learning methods can be applied to other classes of enzymes and hence, used as a tool to expand the knowledgebase of metabolic reactions paving the way for next generation of metabolic/ pathway engineering.
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Post-Transplant Outcomes in High-Risk Compared with Non-High-Risk Multiple Myeloma: A CIBMTR Analysis.
Conventional cytogenetics and interphase fluorescence in situ hybridization (FISH) identify high-risk multiple myeloma (HRM) populations characterized by poor outcomes. We analyzed these differences among HRM versus non-HRM populations after upfront autologous hematopoietic cell transplantation (autoHCT). Between 2008 and 2012, 715 patients with multiple myeloma identified by FISH and/or cytogenetic data with upfront autoHCT were identified in the Center for International Blood and Marrow Transplant Research database. HRM was defined as del17p, t(4;14), t(14;16), hypodiploidy (-Y) or chromosome 1 p and 1q abnormalities; all others were non-HRM. Among 125 HRM patients (17.5%), induction with bortezomib and immunomodulatory agents (imids) was higher compared with non-HRM (56% versus 43%, P \u3c .001) with similar pretransplant complete response (CR) rates (14% versus 16%, P .1). At day 100 post-transplant, at least a very good partial response was 59% in HRM and 61% in non-HRM (P = .6). More HRM patients received post-transplant therapy with bortezomib and imids (26% versus 12%, P = .004). Three-year post-transplant progression-free (PFS) and overall survival (OS) rates in HRM versus non-HRM were 37% versus 49% (P \u3c .001) and 72% versus 85% (P \u3c .001), respectively. At 3 years, PFS for HRM patients with and without post-transplant therapy was 46% (95% confidence interval [CI], 33 to 59) versus 14% (95% CI, 4 to 29) and in non-HRM patients with and without post-transplant therapy 55% (95% CI, 49 to 62) versus 39% (95% CI, 32 to 47); rates of OS for HRM patients with and without post-transplant therapy were 81% (95% CI, 70 to 90) versus 48% (95% CI, 30 to 65) compared with 88% (95% CI, 84 to 92) and 79% (95% CI, 73 to 85) in non-HRM patients with and without post-transplant therapy, respectively. Among patients receiving post-transplant therapy, there was no difference in OS between HRM and non-HRM (P = .08). In addition to HRM, higher stage, less than a CR pretransplant, lack of post-transplant therapy, and African American race were associated with worse OS. In conclusion, we show HRM patients achieve similar day 100 post-transplant responses compared with non-HRM patients, but these responses are not sustained. Post-transplant therapy appeared to improve the poor outcomes of HRM
Multicenter Evaluation of Diagnostic Circulating Biomarkers to Detect Sight-Threatening Diabetic Retinopathy
Importance: It is a global challenge to provide regular retinal screening for all people with diabetes to detect sight-threatening diabetic retinopathy (STDR). Objective: To determine if circulating biomarkers could be used to prioritize people with type 2 diabetes for retinal screening to detect STDR. Design, Setting, and Participants: This cross-sectional study collected data from October 22, 2018, to December 31, 2021. All laboratory staff were masked to the clinical diagnosis, assigned a study cohort, and provided with the database containing the clinical data. This was a multicenter study conducted in parallel in 3 outpatient ophthalmology clinics in the UK and 2 centers in India. Adults 40 years and older were categorized into 4 groups: (1) no history of diabetes, (2) type 2 diabetes of at least 5 years' duration with no evidence of DR, (3) nonproliferative DR with diabetic macular edema (DME), or (4) proliferative DR. STDR comprised groups 3 and 4. Exposures: Thirteen previously verified biomarkers were measured using enzyme-linked immunosorbent assay. Main Outcomes and Measures: Severity of DR and presence of DME were diagnosed using fundus photographs and optical coherence tomography. Weighted logistic regression and receiver operating characteristic curve analysis (ROC) were performed to identify biomarkers that discriminate STDR from no DR beyond the standard clinical parameters of age, disease duration, ethnicity (in the UK) and hemoglobin A1c. Results: A total of 538 participants (mean [SD] age, 60.8 [9.8] years; 319 men [59.3%]) were recruited into the study. A total of 264 participants (49.1%) were from India (group 1, 54 [20.5%]; group 2, 53 [20.1%]; group 3, 52 [19.7%]; group 4, 105 [39.8%]), and 274 participants (50.9%) were from the UK (group 1, 50 [18.2%]; group 2, 70 [25.5%]; group 3, 55 [20.1%]; group 4, 99 [36.1%]). ROC analysis (no DR vs STDR) showed that in addition to age, disease duration, ethnicity (in the UK) and hemoglobin A1c, inclusion of cystatin C had near-acceptable discrimination power in both countries (area under the receiver operating characteristic curve [AUC], 0.779; 95% CI, 0.700-0.857 in 215 patients in the UK with complete data; AUC, 0.696; 95% CI, 0.602-0.791 in 208 patients in India with complete data). Conclusions and Relevance: Results of this cross-sectional study suggest that serum cystatin C had good discrimination power in the UK and India. Circulating cystatin-C levels may be considered as a test to identify those who require prioritization for retinal screening for STDR
Improved Outcomes After Autologous Hematopoietic Cell Transplantation for Light Chain Amyloidosis: A Center for International Blood and Marrow Transplant Research Study
Autologous hematopoietic cell transplantation, or autotransplantation, is effective in light-chain amyloidosis (AL), but it is associated with a high risk of early mortality (EM). In a multicenter randomized comparison against oral chemotherapy, autotransplantation was associated with 24% EM. We analyzed trends in outcomes after autologous hematopoietic cell transplantation for AL in North America
Overload management in real-time control applications using (m, k)-firm guarantee
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder
Synchronization and distributed agreement in real-time systems.
A Byzantine fault is an arbitrary behavior on the part of a hardware component, a software module or a logical entity. The focus of this dissertation is on problems related to designing systems that are resilient to Byzantine faults. This work is important in computer systems that are designed to control critical real-time applications such as avionics, life-support systems, nuclear reactors, automobile engines and process control systems. The main emphasis of the dissertation is on developing techniques for synchronizing system components and ensuring distributed agreement in the presence of Byzantine faults. First, hardware and software schemes are proposed for synchronizing the local clocks in the nodes of a distributed system. These schemes compare favorably with existing schemes in terms of cost as well as tightness of synchronization. Next, a clock distribution scheme is proposed for delivering the clock signal to the components within a node without creating any timing uncertainties. The key aspect of this scheme is that both delay and skew are taken into account when determining the layout of the clock lines. The global time base that results from these two solutions can be used to simplify fault tolerant algorithms for various design problems in real-time systems. This is illustrated by presenting a checkpointing and rollback recovery algorithm that requires considerably less time and space overhead than other algorithms. Finally, a solution is derived for diagnosing components with Byzantine faults. This is useful for reducing the number of faults that need to be tolerated to meet a specified reliability requirement which in turn reduces the overhead imposed by any algorithm that is resilient to Byzantine faults. In short, the work accomplished in this dissertation demonstrates that it is not necessary to limit oneself to small distributed systems in order to achieve a high reliability. The techniques developed here are economical in small and in large distributed systems.Ph.D.Computer scienceElectrical engineeringUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/162512/1/9013992.pd
Multiuser Receiver Aware Multicast in CDMA-based Multihop Wireless Ad-hoc Networks ABSTRACT
Resource placement with multiple adjacency constraints in k-ary n-cubes
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder
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