Action of Enzymes from Clostridium tertium A on the Group A Antigenic Determinant of Human Erythrocytes

It is well known that Clostridium tertium A produces Adecomposing enzymes. We investigated the changes in ABO-antigenicity of human erythrocytes caused by the culture filtrate from this bacteria. Group A erythrocytes were specifically affected, and a decrease in A-activity and an enhancement of H-activity were observed. No change was observed on group B and O cells. There was a significant difference between the agglutinabilities of group A1 and A2 erythrocytes treated with Cl. tertium culture filtrate. A2 erythrocytes completely lost their agglutinability against undiluted anti-A sera. In contrast, A1 erythrocytes preserved a low Aantigenicity. It was clear that this difference reflected the heterogenous nature of A-antigenicity on group A cell membranes. On the other hand, it was suggested that the A-decomposing enzymes in the culture filtrate also had a heterogenous nature. Our crude enzyme preparation was completely inhibited by D-galactosamine, and weakly by N-acetyl-Dgalactosamine or D-galactose. Further enzyme purification was required to elucidate the differences in the antigenic determinants or the structural basis between A1 and A2 erythrocytes

Role of exosomes as a proinflammatory mediator in the development of EBV-associated lymphoma

Epstein-Barr virus (EBV) causes various diseases in the elderly, including B-cell lymphoma such as Hodgkin's lymphoma and diffuse large B-cell lymphoma. Here, we show that EBV acts in trans on noninfected macrophages in the tumor through exosome secretion and augments the development of lymphomas. In a humanized mouse model, the different formation of lymphoproliferative disease (LPD) between 2 EBV strains (Akata and B95-8) was evident. Furthermore, injection of Akata-derived exosomes affected LPD severity, possibly through the regulation of macrophage phenotype in vivo. Exosomes collected from Akata-lymphoblastoid cell lines reportedly contain EBV-derived noncoding RNAs such as BamHI fragment A rightward transcript (BART) micro-RNAs (miRNAs) and EBVencoded RNA.We focused on the exosome-mediated delivery of BART miRNAs. In vitro, BART miRNAs could induce the immune regulatory phenotype in macrophages characterized by the gene expressions of interleukin 10, tumor necrosis factor-a, and arginase 1, suggesting the immune regulatory role of BART miRNAs.The expression level of an EBV-encoded miRNA was strongly linked to the clinical outcomes in elderly patients with diffuse large B-cell lymphoma.These results implicate BART miRNAs as 1 of the factors regulating the severity of lymphoproliferative disease and as a diagnostic marker for EBV1 B-cell lymphoma. (Blood. 2018;131(23):2552-2567)

Application of a computer vision technique to animal-borne video data: extraction of head movement to understand sea turtles’visual assessment of surroundings

Proceedings of the 5th Bio-Logging Science Symposium[Background] An animal-borne video recording system has recently been developed to study the behavior of free-ranging animals. In contrast to other types of sensor data (i.e., acceleration), video images offer the advantage of directly acquiring information without analysis. However, most previous findings have only been obtained through visual observation of image data. Here, we demonstrate a new method of data analysis for animal-borne videos using a computer vision technique referred to as template matching. As a case study, we tracked the horizontal head movements of green turtles (Chelonia mydas) to investigate how they move their heads to look around the underwater environment. [Results] Template matching allowed tracking of head movements with high accuracy (0.34 ± 0.12 % and 0.52 ± 0.29 % of the root-mean-square error on the x- and y-coordinates, respectively), high true (86.2 ± 8.1 %), and low false extraction rates (6.6 ± 8.4 %). However the program sometimes failed because the turtle’s head would move out of range of the video. During cruising swimming, green turtles did not significantly move their heads to one side, moving with a ratio of 50.5:49.5 (left: right). Green turtles moved their heads from side to side more widely and more slowly before (12.0 ± 4.6 point and 0.25 ± 0.03 Hz, respectively) and after taking a breath (27.5 ± 2.9 point and 0.27 ± 0.03 Hz) compared to during cruising swimming (8.4 ± 3.8 point and 0.32 ± 0.01 Hz). Before feeding, turtles moved their heads slowly (0.23 ± 0.03 Hz) and narrowly (9.3 ± 3.6 point). Our combined approach using video and gyro loggers revealed that when making a turn, turtles always turned their heads to the side 1.38 ± 0.77 s before turning their body. [Conclusions] Our method enables researchers to quantitatively extract information regarding vision cognition and behavioral responses in green turtles in the wild that could not otherwise be obtained from other sensors used in previous studies. This new method using a combination of computer vision and bio-logging (e.g., gyroscope) can serve as a powerful tool in animal behavior and ecological studies