Publications by authors named "Margriet Dijkstra-Tiekstra"

Introduction: The aim of this study was to determine the efficacy of early tocilizumab treatment for hospitalized patients with COVID-19 disease.

Methods: Open-label randomized phase II clinical trial investigating tocilizumab in patients with proven COVID-19 admitted to the general ward and in need of supplemental oxygen. The primary endpoint of the study was 30-day mortality with a prespecified 2-sided significance level of α = 0.

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Needle-free intranasal vaccines offer major potential advantages, especially against pathogens entering via mucosal surfaces. As yet, there is no effective vaccine against respiratory syncytial virus (RSV), a ubiquitous pathogen of global importance that preferentially infects respiratory epithelial cells; new strategies are urgently required. Here, we report the safety and immunogenicity of a novel mucosal RSV F protein vaccine linked to an immunostimulatory bacterium-like particle (BLP).

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Hematopoietic progenitor cells (HPC) are stored in cryopreservation bags that are resistant to liquid nitrogen. Since Cryocyte bags of Baxter (B-bags) are no longer available, an alternative bag was sought. Also, the influence of freezing volume was studied.

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Hydroxyethyl starch (HES) is used to separate hematopoietic progenitor cells after bone marrow (BM) collection from red blood cells. The aims were to study alternatives for HAES-steril (200 kDa; not available anymore) and to optimize the sedimentation process. Using WBC-enriched product (10 × 10(9) WBC/L), instead of BM, sedimentation at 10% hematocrit using final 0.

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Background: Adding dimethyl sulfoxide (DMSO) to hematopoietic progenitor cells (HPCs) causes an exothermic reaction, potentially affecting their viability. The freezing method might also influence this. The aim was to investigate the effect of 1) precooling of DMSO and plasma (D/P) and white blood cell (WBC)-enriched product, 2) DMSO concentration of D/P, 3) freezing program, and 4) storage method on WBC quality.

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Background: Developing new quality control methods for platelet concentrates (PCs) can contribute to increasing transfusion safety and efficiency. The aim of this study was to investigate in a large field test the quality of expired PCs and whether 100% noninvasive pH monitoring can be used to predict PC quality.

Study Design And Methods: The pH of 13,693 PCs produced for transfusion was monitored daily using Blood Storage, Inc.

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Background: Fibrin sealant is a human blood product consisting of two components: cryoprecipitate and thrombin. Commercial fibrin sealants are produced from multidonors, increasing the viral risk, and contain fibrinolytic inhibitors such as tranexamic acid or bovine aprotinin. Autologous fibrin sealants reduce the viral risk and are mostly produced during a surgical procedure or well in advance.

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Background: During processing and storage, red blood cells (RBCs) undergo changes and cell injury resulting in hemolysis. Mostly, the separation of whole blood in top-and-bottom quadruple bag systems with break openings takes less than 4 minutes. However, longer separation times are not uncommon.

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Background: Red blood cell (RBC) units stored for more than 2 weeks at 4 degrees C are currently considered of impaired quality. This opinion has primarily been based on altered RBC rheologic properties (i.e.

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Background: Hematology analyzers are designed to count whole blood samples, but are also used by blood centers to perform quality control on blood components. In platelet (PLT) concentrates, the number of PLTs is approximately fivefold higher and red blood cells are absent, causing variable PLT counting results. It was our aim to compare currently used hematology analyzers for counting PLTs in PLT concentrates using fixed human PLTs.

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Background: Platelet (PLT) storage lesions might depend on the total PLT count in the storage container and also on the PLT pooling system, especially the storage container, that is used for preparation of PLT concentrates (PCs). In this study, the PLT capacity of four commercially available PLT pooling systems was studied.

Materials And Methods: Four PCs were prepared in pooling systems of Baxter, Fresenius, Terumo, or Pall.

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Background: For logistic reasons, possibilities to produce both platelet (PLT) concentrates prepared from fresh or overnight-stored whole blood (fresh and o/n PCs, respectively) are convenient. The consequences of both possibilities are not well described. The PLT pooling system used might also influence the condition of PCs.

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Background: Hematology analyzers use impedance, optical, and/or immunologic techniques for counting platelets (PLTs). PLT counting in whole blood has been validated thoroughly; however, this is not the case for PLT counting in PLT concentrates (PCs), in which red cells (RBCs) are absent. Therefore, this study is focused on PLT counting in PCs to study use of ethylenediaminetetraacetate (EDTA), carryover, and accuracy of the analyzers.

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Background: Flow cytometric methods can be used to count residual white blood cells (WBCs) in WBC-reduced blood products, which should contain fewer than 1 x 10(6) WBCs per unit (approximately 3.3 WBCs/ microL). In this study two flow cytometric methods for counting WBCs under routine conditions in nine laboratories were evaluated.

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