No abstract

To define acaricidal mechanism of a new acaricidal AKD-2023 (2-acetoxy-3-n-dodecyl-l, 4naphthoquinone) and its metabolite, DHN (2-hydroxy-3-n-dodecyl-l, 4-naphthoquinone), the effects of these compounds on the respiration of flight-muscle mitochondria isolated from house flies were investigated. The inhibitory potency of AKD-2023 for succinate and pyruvate oxidation activity was much less than that of DHN. This result suggested that the hydrolyzed metabolite, DHN is virtually biologically active and inhibits the respiration of mitochondria. It was also proved that the inhibition occurs at the complex III in mitochondrial electron transfer chain. On the basis of reduction kinetics of cytochromes b and c1, the binding site was shown to be ubiquinol oxidation site (Q0 center) of complex III, being different from that of other acaricides developed recently.

SummaryIt has been well established that CD45 is a key receptor-type protein tyrosine phosphatase (PTPase) regulating Src-family protein tyrosine kinase (Src-PTK) in T and B lymphocytes. However, precisely how CD45 exerts its effect in these lymphocytes remains controversial. We recently reported that Jacalin, an a-O-glycoside of the disaccharide Thomsen-Friedenreich antigen-specific lectin from jackfruit seeds, caused marked T-cell activation in response to T-cell receptor ligation and CD28 costimulation by binding to CD45. On extending the reported research, we found that CD45 and isoforms are major Jacalin receptors on B lymphocytes, and that the glycosylation of CD45 is involved in the interaction of Jacalin with the PTPase. In contrast to Jacalin-stimulated T-cell activation, we found that Jacalin induced human B-lymphocyte apoptosis, resulting in calcium mobilization and calpain activation, suggesting that the calciumcalpain pathway may mediate the Jacalin-induced apoptosis. Importantly, the apoptosis was effectively blocked by a specific CD45 PTPase inhibitor, indicating that Jacalin induces human B-lymphocyte apoptosis through CD45 triggering. Furthermore, we found that Jacalin significantly increased the C-terminal inhibitory tyrosine (Tyr507) phosphorylation of Src-PTK Lyn, one of the major substrates of CD45 PTPase, and this effect was also observed on incubation of B lymphocytes with the specific CD45 PTPase inhibitor, suggesting that Jacalin stimulation results in increasing C-terminal tyrosine phosphorylation of the kinase through inhibition of CD45 tyrosine phosphatase activity in human B lymphocytes. Therefore, the down-modulation of Lyn kinase may play a role in the regulation of B-lymphocyte viability.

Background and Aim Linked color imaging (LCI) is useful for screening in the gastrointestinal tract; however, its true clinical benefit has not been determined. The aim of this study was to determine the objective advantage of LCI for detection of upper gastrointestinal neoplasms. Methods Nine endoscopists, including three novices, three trainees, and three experts, prospectively performed eye tracking. From 30 cases of esophageal or gastric neoplasm and 30 normal cases without neoplasms, a total of 120 images, including 60 pair images of white light imaging (WLI) and LCI taken at the same positions and angles, were randomly shown for 10 s. The sensitivity of tumor detection as a primary endpoint was evaluated and sensitivities by organ, size, and visual gaze pattern were also assessed. Color differences (ΔE using CIE1976 [L*a*b*]) between lesions and surrounding mucosa were measured and compared with detectability. Results A total of 1080 experiments were completed. The sensitivities of tumor detection in WLI and LCI were 53.7% (50.1–56.8%) and 68.1% (64.8–70.8%), respectively (P = 0.002). LCI provided higher sensitivity than WLI for the novice and trainee groups (novice: 42.2% [WLI] vs 65.6% [LCI], P = 0.003; trainee: 54.4% vs 70.0%, P = 0.045). No significant correlations were found between sensitivity and visual gaze patterns. LCI significantly increased ΔE, and the diagnostic accuracy with WLI depended on ΔE. Conclusions In conclusion, LCI significantly improved sensitivity in the detection of epithelial neoplasia and enabled epithelial neoplasia detection that is not possible with the small color difference in WLI. (UMIN000047944).