564 research outputs found

    Effects of unidirectional flow shear stresses on the formation, fractal microstructure and rigidity of incipient whole blood clots and fibrin gels

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    Incipient clot formation in whole blood and fibrin gels was studied by the rheometric techniques of controlled stress parallel superposition (CSPS) and small amplitude oscillatory shear (SAOS). The effects of unidirectional shear stress on incipient clot microstructure, formation kinetics and elasticity are reported in terms of the fractal dimension (df ) of the fibrin network, the gel network formation time (TGP ) and the shear elastic modulus, respectively. The results of this first haemorheological application of CSPS reveal the marked sensitivity of incipient clot microstructure to physiologically relevant levels of shear stress, these being an order of magnitude lower than have previously been studied by SAOS. CSPS tests revealed that exposure of forming clots to increasing levels of shear stress produces a corresponding elevation in df , consistent with the formation of tighter, more compact clot microstructures under unidirectional flow. A corresponding increase in shear elasticity was recorded. The scaling relationship established between shear elasticity and df for fibrin clots and whole blood confirms the fibrin network as the dominant microstructural component of the incipient clot in terms of its response to imposed stress. Supplementary studies of fibrin clot formation by rheometry and microscopy revealed the substantial additional network mass required to increase df and provide evidence to support the hypothesis that microstructural changes in blood clotted under unidirectional shear may be attributed to flow enhanced thrombin generation and activation. CSPS also identified a threshold value of unidirectional shear stress above which no incipient clot formation could be detected. CSPS was shown to be a valuable haemorheological tool for the study of the effects of physiological and pathological levels of shear on clot properties

    Anti-CD38 antibody therapy for patients with relapsed/refractory multiple myeloma: differential mechanisms of action and recent clinical trial outcomes.

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    CD38 is a transmembrane glycoprotein that functions both as a receptor and an ectoenzyme, playing key roles in the regulation of calcium signaling and migration of immune cells to tumor microenvironments. High expression on multiple myeloma (MM) cells and limited expression on normal cells makes CD38 an ideal target for the treatment of MM patients. Two monoclonal antibodies directed at CD38, isatuximab and daratumumab, are available for use in patients with relapsed and/or refractory MM (RRMM); daratumumab is also approved in newly diagnosed MM and light-chain amyloidosis. Clinical experience has shown that anti-CD38 antibody therapy is transforming treatment of MM owing to its anti-myeloma efficacy and manageable safety profile. Isatuximab and daratumumab possess similarities and differences in their mechanisms of action, likely imparted by their binding to distinct, non-overlapping epitopes on the CD38 molecule. In this review, we present the mechanistic properties of these two antibodies and outline available evidence on their abilities to induce adaptive immune responses and modulate the bone marrow niche in MM. Further, we discuss differences in regulatory labeling between these two agents and analyze recent key clinical trial results, including evidence in patients with underlying renal impairment and other poor prognostic factors. Finally, we describe the limited existing evidence for the use of isatuximab or daratumumab after disease progression on prior anti-CD38 mono- or combination therapy, highlighting the need for additional clinical evaluations to define optimal anti-CD38 antibody therapy selection and sequencing in RRMM

    Daratumumab, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Patients With Previously Treated Multiple Myeloma : Three-year Follow-up of CASTOR

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    Background: In the phase III CASTOR study in relapsed or refractory multiple myeloma, daratumumab, bortezomib, and dexamethasone (D-Vd) demonstrated significant clinical benefit versus Vd alone. Outcomes after 40.0 months of median follow-up are discussed. Patients and methods: Eligible patients had received 65 1 line of treatment and were administered bortezomib (1.3 mg/m2) and dexamethasone (20 mg) for 8 cycles with or without daratumumab (16 mg/kg) until disease progression. Results: Of 498 patients in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247), 47% had 1 prior line of treatment (1PL; D-Vd, n = 122; Vd, n = 113). Median progression-free survival (PFS) was significantly prolonged with D-Vd versus Vd in the ITT population (16.7 vs. 7.1 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.25-0.40; P < .0001) and the 1PL subgroup (27.0 vs. 7.9 months; HR, 0.22; 95% CI, 0.15-0.32; P < .0001). In lenalidomide-refractory patients, the median PFS was 7.8 versus 4.9 months (HR, 0.44; 95% CI, 0.28-0.68; P = .0002) for D-Vd (n = 60) versus Vd (n = 81). Minimal residual disease (MRD)-negativity rates (10-5) were greater with D-Vd versus Vd (ITT: 14% vs. 2%; 1PL: 20% vs. 3%; both P < .0001). PFS2 was significantly prolonged with D-Vd versus Vd (ITT: HR, 0.48; 95% CI, 0.38-0.61; 1PL: HR, 0.35; 95% CI, 0.24-0.51; P < .0001). No new safety concerns were observed. Conclusion: After 3 years, D-Vd maintained significant benefits in patients with relapsed or refractory multiple myeloma with a consistent safety profile. D-Vd provided the greatest benefit at first relapse and increased MRD-negativity rates

    Daratumumab, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Patients With Previously Treated Multiple Myeloma: Three-year Follow-up of CASTOR

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    Background: In the phase III CASTOR study in relapsed or refractory multiple myeloma, daratumumab, bortezomib, and dexamethasone (D-Vd) demonstrated significant clinical benefit versus Vd alone. Outcomes after 40.0 months of median follow-up are discussed. Patients and Methods: Eligible patients had received ≄ 1 line of treatment and were administered bortezomib (1.3 mg/m2) and dexamethasone (20 mg) for 8 cycles with or without daratumumab (16 mg/kg) until disease progression. Results: Of 498 patients in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247), 47% had 1 prior line of treatment (1PL; D-Vd, n = 122; Vd, n = 113). Median progression-free survival (PFS) was significantly prolonged with D-Vd versus Vd in the ITT population (16.7 vs. 7.1 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.25-0.40; P < .0001) and the 1PL subgroup (27.0 vs. 7.9 months; HR, 0.22; 95% CI, 0.15-0.32; P < .0001). In lenalidomide-refractory patients, the median PFS was 7.8 versus 4.9 months (HR, 0.44; 95% CI, 0.28-0.68; P = .0002) for D-Vd (n = 60) versus Vd (n = 81). Minimal residual disease (MRD)–negativity rates (10−5) were greater with D-Vd versus Vd (ITT: 14% vs. 2%; 1PL: 20% vs. 3%; both P < .0001). PFS2 was significantly prolonged with D-Vd versus Vd (ITT: HR, 0.48; 95% CI, 0.38-0.61; 1PL: HR, 0.35; 95% CI, 0.24-0.51; P < .0001). No new safety concerns were observed. Conclusion: After 3 years, D-Vd maintained significant benefits in patients with relapsed or refractory multiple myeloma with a consistent safety profile. D-Vd provided the greatest benefit at first relapse and increased MRD-negativity rates.CASTOR showed the significant clinical benefit of daratumumab plus bortezomib and dexamethasone for patients with previously treated multiple myeloma. With ∌3 years median follow-up, this regimen continues to demonstrate significantly improved progression-free survival with higher minimal residual dis

    Childhood Asthma and Environmental Exposures at Swimming Pools: State of the Science and Research Recommendations

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    OBJECTIVES: Recent studies have explored the potential for swimming pool disinfection by-products (DBPs), which are respiratory irritants, to cause asthma in young children. Here we describe the state of the science on methods for understanding children's exposure to DBPs and biologics at swimming pools and associations with new-onset childhood asthma and recommend a research agenda to improve our understanding of this issue. DATA SOURCES: A workshop was held in Leuven, Belgium, 21-23 August 2007, to evaluate the literature and to develop a research agenda to better understand children's exposures in the swimming pool environment and their potential associations with new-onset asthma. Participants, including clinicians, epidemiologists, exposure scientists, pool operations experts, and chemists, reviewed the literature, prepared background summaries, and held extensive discussions on the relevant published studies, knowledge of asthma characterization and exposures at swimming pools, and epidemiologic study designs. SYNTHESIS: Childhood swimming and new-onset childhood asthma have clear implications for public health. If attendance at indoor pools increases risk of childhood asthma, then concerns are warranted and action is necessary. If there is no such relationship, these concerns could unnecessarily deter children from indoor swimming and/or compromise water disinfection. CONCLUSIONS: Current evidence of an association between childhood swimming and new-onset asthma is suggestive but not conclusive. Important data gaps need to be filled, particularly in exposure assessment and characterization of asthma in the very young. Participants recommended that additional evaluations using a multidisciplinary approach are needed to determine whether a clear association exists

    Tournaments and piece rates revisited: a theoretical and experimental study of output-dependent prize tournaments

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    Tournaments represent an increasingly important component of organizational compensation systems. While prior research focused on fixed-prize tournaments where the prize to be awarded is set in advance, we introduce ‘output-dependent prizes’ where the tournament prize is endogenously determined by agents’ output—it is high when the output is high and low when the output is low. We show that tournaments with output-dependent prizes outperform fixed-prize tournaments and piece rates. A multi-agent experiment supports the theoretical result

    Evaluating housing quality, health and safety using an Internet-based data collection and response system: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Typically housing and health surveys are not integrated together and therefore are not representative of population health or national housing stocks. In addition, the existing channels for distributing information about housing and health issues to the general public are limited. The aim of this study was to develop a data collection and response system that would allow us to assess the Finnish housing stock from the points of view of quality, health and safety, and also to provide a tool to distribute information about important housing health and safety issues.</p> <p>Methods</p> <p>The data collection and response system was tested with a sample of 3000 adults (one per household), who were randomly selected from the Finnish Population Register Centre. Spatial information about the exact location of the residences (i.e. coordinates) was included in the database inquiry. People could participate either by completing and returning a paper questionnaire or by completing the same questionnaire via the Internet. The respondents did not receive any compensation for their time in completing the questionnaire.</p> <p>Results</p> <p>This article describes the data collection and response system and presents the main results of the population-based testing of the system. A total of 1312 people (response rate 44%) answered the questionnaire, though only 80 answered via the Internet. A third of the respondents had indicated they wanted feedback. Albeit a majority (>90%) of the respondents reported being satisfied or quite satisfied with their residence, there were a number of prevalent housing issues identified that can be related to health and safety.</p> <p>Conclusions</p> <p>The collected database can be used to evaluate the quality of the housing stock in terms of occupant health and safety, and to model its association with occupant health and well-being. However, it must be noted that all the health outcomes gathered in this study are self-reported. A follow-up study is needed to evaluate whether the occupants acted on the feedback they received. Relying solely on an Internet-based questionnaire for collecting data would not appear to provide an adequate response rate for random population-based surveys at this point in time.</p
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