A novel quantitative method to evaluate the contribution of platelet products to white thrombus formation in reconstituted blood under flow conditions.

Background And Objectives: Currently, the quality of platelet (PLT) products is evaluated using a series of in vitro tests, which only analyse PLTs as an inspection material. However, it would be ideal to assess the physiological functions of PLTs under conditions similar to the sequential blood haemostatic process. In this study, we attempted to establish an in vitro system where the thrombogenicity of PLT products was evaluated in the presence of red blood cells (RBCs) and plasma using a microchamber under constant shear stress (600/s).

Gap Junction-Mediated Transport of Metabolites Between Stem Cells and Vascular Endothelial Cells.

We have previously demonstrated that small molecular transfer, such as glucose, between hematopoietic stem cells (HSCs) or mesenchymal stem cells (MSCs) and vascular endothelial cells via gap junctions constitutes an important mechanism of stem cell therapy. Cell metabolites are high-potential small-molecule candidates that can be transferred to small molecules between stem cells and vascular endothelial cells. Here, we investigated the differences in metabolite levels between stem cells (HSCs and MSCs), vascular endothelial cells, and the levels of circulating non-hematopoietic white blood cells (WBCs).

Production and nonclinical evaluation of an autologous iPSC-derived platelet product for the iPLAT1 clinical trial.

Donor-derived platelets are used to treat or prevent hemorrhage in patients with thrombocytopenia. However, ∼5% or more of these patients are complicated with alloimmune platelet transfusion refractoriness (allo-PTR) due to alloantibodies against HLA-I or human platelet antigens (HPA). In these cases, platelets from compatible donors are necessary, but it is difficult to find such donors for patients with rare HLA-I or HPA.

Automated preparation of washed platelet concentrates through spinning-membrane filtration.

Background: Washed platelet concentrates (WPC), prepared with an automated system cell processor (ACP), have recently been approved to be manufactured and marketed in Japan. From the perspective of risk management, it is preferable to secure alternative technologies for ACP. Here, we conducted a study to evaluate the quality of WPC prepared using an automated membrane filtration-based system, Lovo.

Comparison of the programmed freezer method and deep freezer method in the manufacturing of frozen red blood cell products.

Background And Objectives: Frozen-thawed red blood cells (FTRCs) are useful blood components to patients with rare blood phenotypes. However, frozen red blood cells (FRCs) sometimes cause significant haemolysis after thawing due to the freeze/thaw process. In this study, we aimed to focus on the former process and reduce process-related haemolysis.

Dual preparation of plasma and platelet concentrates in platelet additive solution from platelet concentrates in plasma using a novel filtration system.

Background And Objectives: Platelet concentrates suspended in a platelet additive solution (PAS-PC) are associated with a reduction in allergic response and are suitable for preparing pathogen-inactivated PC. We aimed to develop an efficient platform for the dual preparation of PAS-PC and platelet-poor plasma.

Materials And Methods: PAS-PC was prepared in six steps by using a hollow-fibre system based on cross-flow filtration: priming, loading PC, loading PAS, collection of filtered liquid (flow-through) and collection of platelets by washing with PAS followed by washing with air.

UV light-emitting diode (UV-LED) at 265 nm as a potential light source for disinfecting human platelet concentrates.

The risk of sepsis through bacterial transmission is one of the most serious problems in platelet transfusion. In processing platelet concentrates (PCs), several methods have been put into practice to minimize the risk of bacterial transmission, such as stringent monitoring by cultivation assays and inactivation treatment by photoirradiation with or without chemical agents. As another potential option, we applied a light-emitting diode (LED) with a peak emission wavelength of 265 nm, which has been shown to be effective for water, to disinfect PCs.

The Kg-antigen, RhAG with a Lys164Gln mutation, gives rise to haemolytic disease of the newborn.

The Kg-antigen was first discovered in an investigation of a mother whose infant had haemolytic disease of the newborn (HDN). The antibody against the Kg-antigen is believed to be responsible for HDN. The Kg-antigen is provisionally registered under the number 700045, according to the Red Cell Immunogenetics and Blood Group Terminology.

Erythrocytes lacking the Langereis blood group protein ABCB6 are resistant to the malaria parasite .

The ATP-binding cassette transporter was recently discovered to encode the Langereis (Lan) blood group antigen. Lan null individuals are asymptomatic, and the function of ABCB6 in mature erythrocytes is not understood. Here, we assessed ABCB6 as a host factor for malaria parasites during erythrocyte invasion.

High-resolution melting analysis as an alternative method for human neutrophil antigen genotyping.

Human neutrophil antigen (HNA)-typed granulocyte panels are widely used to screen for the presence of HNA antibodies and to determine antibody specificity. Many laboratories screen donors for HNA genotypes using low-throughput methods such as allele-specific polymerase chain reaction (PCR), PCR-restriction fragment-length polymorphism, and multiplex PCR. In the present study, we used a high-resolution melting (HRM) analysis to determine HNA genotypes.

Defining the Jr(a-) phenotype in the Japanese population.

Background: The Jr(a-) phenotype is rare in European and North American populations but is not so rare in Japanese and other Asian populations. Recently, two groups have established the connection between the Jr(a-) phenotype and the ATP-binding cassette, member G2 (ABCG2) gene and concluded that ABCG2-null alleles encode the Jr(a-) phenotype. In Japanese Red Cross Blood Centers, the Jr(a-) phenotype is found with a prevalence of 0.

ABCB6 is dispensable for erythropoiesis and specifies the new blood group system Langereis.

The human ATP-binding cassette (ABC) transporter ABCB6 has been described as a mitochondrial porphyrin transporter essential for heme biosynthesis, but it is also suspected to contribute to anticancer drug resistance, as do other ABC transporters located at the plasma membrane. We identified ABCB6 as the genetic basis of the Lan blood group antigen expressed on red blood cells but also at the plasma membrane of hepatocellular carcinoma (HCC) cells, and we established that ABCB6 encodes a new blood group system (Langereis, Lan). Targeted sequencing of ABCB6 in 12 unrelated individuals of the Lan(-) blood type identified 10 different ABCB6 null mutations.

High-resolution melting analysis for genotyping Duffy, Kidd and Diego blood group antigens.

High-resolution melting (HRM) analysis is a simpler genotyping method than allele-specific PCR, PCR-restriction fragment length polymorphism and multiplex PCR. Duffy, Kidd and Diego are clinically important blood group antigens. We used a novel method to genotype these three blood group antigens.

The role of aquaporin 3 in the movement of water and cryoprotectants in mouse morulae.

The permeability to water and cryoprotectants of the plasma membrane is crucial to the successful cryopreservation of embryos. Previously, we have shown in mouse morulae that water and glycerol move across the plasma membrane by facilitated diffusion, and we have suggested that aquaporin 3 plays an important role in their movement. In the present study, we clarify the contribution of aquaporin 3 to the movement of water and various cryoprotectants in mouse morulae by measuring the Arrhenius activation energies for permeability to cryoprotectants and water, through artificial expression of aquaporin 3 using Aqp3 cRNA in mouse oocytes, and by suppressing the expression of aquaporin 3 in morulae by injecting double-stranded RNA of Aqp3 at the one-cell zygote stage.

Channel-dependent permeation of water and glycerol in mouse morulae.

The cryosensitivity of mammalian embryos depends on the stage of development. Because permeability to water and cryoprotectants plays an important role in cryopreservation, it is plausible that the permeability is involved in the difference in the tolerance to cryopreservation among embryos at different developmental stages. In this study, we examined the permeability to water and glycerol of mouse oocytes and embryos, and tried to deduce the pathway for the movement of water and glycerol.

Permeability of mouse oocytes and embryos at various developmental stages to five cryoprotectants.

To assess the permeability of mouse oocytes and embryos, matured oocytes and embryos at various stages of development were placed in five cryoprotectant solutions at 25 C for 25 min. From the cross-sectional areas of the oocytes/embryos, the relative change in volume was analyzed. In oocytes, shrinkage was least extensive and recovery was quickest in the propylene glycol solution, showing that propylene glycol permeates the oocytes most rapidly.