Although student engagement with the intellectual work of school is important to students' achievement and to their social and cognitive development, studies over a span of two decades have ...documented low levels of engagement, particularly in the classroom. Examining several theoretical perspectives that attempt to explain engagement through comprehensive frameworks, this study evaluates the effect on engagement of school reform initiatives that are consistent with the theories. The study also investigates whether patterns exist in students' engagement, whether the patterns are consistent across grade levels, and whether class subject matter (mathematics or social studies) differentially affects engagement. The sample includes 3,669 students representing 143 social studies and mathematics classrooms in a nationally selected sample of 24 restructuring elementary, middle, and high schools. Because of the nature of the nested data (students nested within classrooms nested within schools), the analysis is conducted using hierarchical linear modeling in its three-level application (HLM3L). The reform initiatives, which are consistent with the theories, eliminate personal background effects. Together with classroom subject matter, they substantially influence engagement. The results are generally consistent across grade levels.
Focusing on school leadership relations between principals and teachers, this study examines the potential of their active collaboration around instructional matters to enhance the quality of ...teaching and student performance. The analysis is grounded in two conceptions of leadership—transformational and instructional. The sample comprises 24 nationally selected restructured schools—8elementary, 8middle, and 8high schools. In keeping with the multilevel structure of the data, the primary analytic technique is hierarchical linear modeling (HLM). The study finds that transformational leadership is a necessary but insufficient condition for instructional leadership. When transformational and shared instructional leadership coexist in an integrated form of leadership, the influence on school performance, measured by the quality of its pedagogy and the achievement of its students, is substantial.
Background
Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is unlikely to be a major transfusion‐transmitted pathogen; however, convalescent plasma is a treatment option used in some ...regions. The risk of transfusion‐transmitted infections can be minimized by implementing Pathogen Inactivation (PI), such as THERAFLEX MB‐plasma and THERAFLEX UV‐Platelets systems. Here we examined the capability of these PI systems to inactivate SARS‐CoV‐2.
Study Design and Methods
SARS‐CoV‐2 spiked plasma units were treated using the THERAFLEX MB‐Plasma system in the presence of methylene blue (~0.8 μmol/L; visible light doses: 20, 40, 60, and 120 standard J/cm2). SARS‐CoV‐2 spiked platelet concentrates (PCs) were treated using the THERAFLEX UV‐platelets system (UVC doses: 0.05, 0.10, 0.15, and 0.20 standard J/cm2). Samples were taken prior to the first and after each illumination dose, and viral infectivity was assessed using an immunoplaque assay.
Results
Treatment of spiked plasma with the THERAFLEX MB‐Plasma system resulted in an average ≥5.03 log10 reduction in SARS‐CoV‐2 infectivity at one third (40 J/cm2) of the standard visible light dose. For the platelet concentrates (PCs), treatment with the THERAFLEX UV‐Platelets system resulted in an average ≥5.18 log10 reduction in SARS‐CoV‐2 infectivity at the standard UVC dose (0.2 J/cm2).
Conclusions
SARS‐CoV‐2 infectivity was reduced in plasma and platelets following treatment with the THERAFLEX MB‐Plasma and THERAFLEX UV‐Platelets systems, to the limit of detection, respectively. These PI technologies could therefore be an effective option to reduce the risk of transfusion‐transmitted emerging pathogens.
BACKGROUND
Yellow fever virus (YFV) is endemic to tropical and subtropical areas in South America and Africa, and is currently a major public health threat in Brazil. Transfusion transmission of the ...yellow fever vaccine virus has been demonstrated, which is indicative of the potential for viral transfusion transmission. An approach to manage the potential YFV transfusion transmission risk is the use of pathogen inactivation (PI) technology systems, such as THERAFLEX MB‐Plasma and THERAFLEX UV‐Platelets (Macopharma). We aimed to investigate the efficacy of these PI technology systems to inactivate YFV in plasma or platelet concentrates (PCs).
STUDY DESIGN AND METHODS
YFV spiked plasma units were treated using THERAFLEX MB‐Plasma system (visible light doses: 20, 40, 60, and 120 standard J/cm2) in the presence of methylene blue (approx. 0.8 μmol/L) and spiked PCs were treated using THERAFLEX UV‐Platelets system (ultraviolet C doses: 0.05, 0.10, 0.15, and 0.20 standard J/cm2). Samples were taken before the first and after each illumination dose and tested for residual virus using a modified plaque assay.
RESULTS
YFV infectivity was reduced by an average of 4.77 log or greater in plasma treated with the THERAFLEX MB‐Plasma system and by 4.8 log or greater in PCs treated with THERAFLEX UV‐Platelets system.
CONCLUSIONS
Our study suggests the THERAFLEX MB‐Plasma and the THERAFLEX UV‐Platelets systems can efficiently inactivate YFV in plasma or PCs to a similar degree as that for other arboviruses. Given the reduction levels observed in this study, these PI technology systems could be an effective option for managing YFV transfusion‐transmission risk in plasma and PCs.
BACKGROUND
Zika virus (ZIKV) has emerged as a potential threat to transfusion safety worldwide. Pathogen inactivation is one approach to manage this risk. In this study, the efficacy of the THERAFLEX ...UV‐Platelets system and THERAFLEX MB‐Plasma system to inactivate ZIKV in platelet concentrates (PCs) and plasma was investigated.
STUDY DESIGN AND METHODS
PCs spiked with ZIKV were treated with the THERAFLEX UV‐Platelets system at 0.05, 0.10, 0.15, and 0.20 J/cm2 UVC. Plasma spiked with ZIKV was treated with the THERAFLEX MB‐Plasma system at 20, 40, 60, and 120 J/cm2 light at 630 nm with at least 0.8 µmol/L methylene blue (MB). Samples were taken before the first and after each illumination dose and tested for residual virus. For each system the level of viral reduction was determined.
RESULTS
Treatment of PCs with THERAFLEX UV‐Platelets system resulted in a mean of 5 log reduction in ZIKV infectivity at the standard UVC dose (0.20 J/cm2), with dose dependency observed with increasing UVC dose. For plasma treated with MB and visible light, ZIKV infectivity was reduced by a mean of at least 5.68 log, with residual viral infectivity reaching the detection limit of the assay at 40 J/cm2 (one‐third the standard dose).
CONCLUSIONS
Our study demonstrates that the THERAFLEX UV‐Platelets system and THERAFLEX MB‐Plasma system can reduce ZIKV infectivity in PCs and pooled plasma to the detection limit of the assays used. These findings suggest both systems have the capacity to be an effective option to manage potential ZIKV transfusion transmission risk.
BACKGROUND
Arboviruses, including dengue (DENV 1‐4), chikungunya (CHIKV), and Ross River (RRV), are emerging viruses that are a risk for transfusion safety globally. An approach for managing this ...risk is pathogen inactivation, such as the THERAFLEX UV‐Platelets system. We investigated the ability of this system to inactivate the above mentioned arboviruses.
STUDY DESIGN AND METHODS
DENV 1‐4, CHIKV, or RRV were spiked into buffy coat (BC)‐derived platelet (PLT) concentrates in additive solution and treated with the THERAFLEX UV‐Platelets system at the following doses: 0.05, 0.1, 0.15, and 0.2 J/cm2 (standard dose). Pre‐ and posttreatment samples were taken for each dose, and the level of viral infectivity was determined.
RESULTS
At the standard ultraviolet C (UVC) dose (0.2 J/cm2), viral inactivation of at least 4.43, 6.34, and 5.13 log or more, was observed for DENV 1‐4, CHIKV, and RRV, respectively. A dose dependency in viral inactivation was observed with increasing UVC doses.
CONCLUSIONS
Our study has shown that DENV, CHIKV, and RRV, spiked into BC‐derived PLT concentrates, were inactivated by the THERAFLEX UV‐Platelets system to the limit of detection of our assay, suggesting that this system could contribute to the safety of PLT concentrates with respect to these emerging arboviruses.
Background
Japanese encephalitis virus (JEV) is endemic to tropical areas in Asia and the Western Pacific. It can cause fatal encephalitis, although most infected individuals are asymptomatic. JEV is ...mainly transmitted to humans through the bite of an infected mosquito, but can also be transmitted through blood transfusion. To manage the potential risk of transfusion transmission, pathogen inactivation (PI) technologies, such as THERAFLEX MB‐Plasma and THERAFLEX UV‐Platelets systems, have been developed. We examined the efficacy of these two PI systems to inactivate JEV.
Study Design and Methods
Japanese encephalitis virus–spiked plasma units were treated using the THERAFLEX MB‐Plasma system (visible light doses, 20, 40, 60, and 120 standard J/cm2) in the presence of methylene blue at approximately 0.8 μmol/L and spiked platelet concentrates (PCs) were treated using the THERAFLEX UV‐Platelets system (UVC doses, 0.05, 0.10, 0.15, and 0.20 standard J/cm2). Samples were taken before the first and after each illumination dose and tested for infectivity using an immunoplaque assay.
Results
Treatment of plasma with the THERAFLEX MB‐Plasma system resulted in an average of 6.59 log reduction in JEV infectivity at one‐sixth of the standard visible light dose (20 J/cm2). For PCs, treatment with the THERAFLEX UV‐Platelet system resulted in an average of 7.02 log reduction in JEV infectivity at the standard UVC dose (0.20 J/cm2).
Conclusions
The THERAFLEX MB‐Plasma and THERAFLEX UV‐Platelets systems effectively inactivated JEV in plasma or PCs, and thus these PI technologies could be an effective option to reduce the risk of JEV transfusion transmission.
BACKGROUND
Cryopreservation of platelets (PLTs) is useful in remote areas to overcome logistic problems associated with supply and can extend the shelf life to 2 years. During cryopreservation, ...properties of PLTs are modified. Whether changes in the cryopreserved PLT (CPP) product are associated with modulation of recipients’ immune function is unknown. We aimed to characterize the immune profile of myeloid dendritic cells (mDCs) and the specialized blood DC antigen (BDCA)3+ subset after exposure to CPPs.
STUDY DESIGN AND METHODS
Using an in vitro whole blood model of transfusion, the effect of CPPs on mDC and BDCA3+ DC surface antigen expression and inflammatory mediator production was examined using flow cytometry. In parallel, polyinosinic:polycytidylic acid (poly(I:C)) or lipopolysaccharide (LPS) was utilized to model processes activated in viral or bacterial infection, respectively.
RESULTS
Cryopreserved PLTs had minimal impact on mDC responses but significantly modulated BDCA3+ DC responses in vitro. Exposure to CPPs alone up regulated BDCA3+ DC CD86 expression and suppressed interleukin (IL)‐8, tumor necrosis factor (TNF)‐α, and interferon‐γ inducible protein (IP)‐10 production. In both models of infection‐related processes, exposure to CPPs down regulated BDCA3+ DC expression of CD40, CD80, and CD83 and suppressed BDCA3+ DC production of IL‐8, IL‐12, and TNF‐α. CPPs suppressed CD86 expression in the presence of LPS and IP‐10 and IL‐6 production with poly(I:C).
CONCLUSION
Cryopreserved PLTs may be immunosuppressive, and this effect is more evident when processes associated with infection are concurrently activated, especially for BDCA3+ DCs. This suggests that transfusion of CPPs in patients with infection may result in impaired BDCA3+ DC responses.
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