Rapid Increase of Gastrointestinal P-Glycoprotein Functional Activity in Response to Etoposide Stimulation.

We previously reported that exposure of human colon adenocarcinoma (Caco-2) cells to the bitter substance phenylthiocarbamide (PTC) rapidly enhanced the transport function of P-glycoprotein (P-gp). In this study, we investigated the short-term effect of etoposide, another bitter-tasting P-gp substrate, on P-gp transport function in the same cell line. We found that etoposide exposure significantly increased both the P-gp protein level in the plasma membrane fraction and the efflux rate of rhodamine123 (Rho123) in Caco-2 cells within 10 min. The efflux ratio (ratio of the apparent permeability coefficient in the basal-to-apical direction to that in the apical-to-basal direction) of Rho123 in etoposide-treated cells was also significantly increased compared with the control. These results indicated that etoposide rapidly enhances P-gp function in Caco-2 cells. In contrast, P-gp expression in whole cells at both the mRNA and protein level was unchanged by etoposide exposure, compared with the levels in non-treated cells. Furthermore, etoposide increased the level of phosphorylated ezrin, radixin and moesin (P-ERM) proteins in the plasma membrane fraction of Caco-2 cells within 10 min. P-gp functional changes were blocked by YM022, an inhibitor of cholecystokinin (CCK) receptor. These results suggest that etoposide induces release of CCK, causing activation of the CCK receptor followed by phosphorylation of ERM proteins, which recruit intracellular P-gp for trafficking to the gastrointestinal membrane, thereby increasing the functional activity of P-gp.

Development of small high-voltage AC power supply for a dielectric barrier discharge plasma actuator.

A dielectric-barrier discharge plasma actuator (DBDPA) is a promising flow control device that can prevent flow separation around an airfoil using electrical discharges. Miniaturizing the DBDPA power supply remains a crucial technological challenge because its size and weight determine the performance of fluid devices equipped with this type of actuator. In this study, we propose a compact high-voltage AC power supply for a DBDPA intended for installation on small airplanes, including unmanned aerial vehicles. The power supply, which consists of a power supply board, a main control board, and a DC/AC converter board, is ∼110 g in weight. It can drive a 300-mm long DBDPA without any substantial voltage drop. The power consumption in standby remains below 1 W, and the maximum consumption during discharge in burst mode at a burst ratio of 5% is 24 W. The power supply uses a lithium-ion battery with a capacity of 1800 mA h, which allows continuous DBDPA operation for ∼1.5 h. An experiment was conducted in a wind tunnel using an airfoil model whose cross-section corresponds to that of an airfoil from a commercial glider airplane. Experimental results reveal that the surface pressure around the airfoil is modified by DBDPA operation, clearly demonstrating the effectiveness of the developed power supply for operating a DBDPA as a flow control device. The size and weight of the proposed power supply can be established as a benchmark to further miniaturize and optimize DBDPA power supplies.

Children's Motives for Admitting to Prosocial Behavior.

There has been extensive research on children's moral evaluation of lying in prosocial situations. Current knowledge regarding the concept of lying has been derived from studies showing that cultural differences exist, whereby non-Western children tend to rate lie telling more positively than Western children do. These findings suggest that there are different views about whether children should publicize their prosocial behaviors and that children have universal motives when they admit to engaging in prosocial behavior. A gender difference has also been found in relation to prosocial behavior. However, previous studies did not investigate in detail children's motives for admission or non-admission to prosocial behavior, and if there is a gender difference. Therefore, this study examined the diversity in and development of motives for admitting or not admitting to engaging in prosocial behavior, with the aim of clarifying these behaviors as a function of children's grade level in school, and how such motives differ with age and gender. Questionnaires from 1345 elementary and junior high school students in Japan were analyzed. Results showed that children's communication tendency with regard to prosocial behavior reports peaked in the fourth grade of elementary school and gradually decreased thereafter. From the third grade of elementary school onwards, children reported that they refrained from admitting prosocial behaviors. Younger children more likely cited honesty as a crucial motive for admitting to prosocial behaviors. Girls were more likely to endorse honesty as a motive than boys were. Moreover, among younger children, girls feared others' negative evaluation and wanted to comply with modesty norms when not admitting. Further research is needed to examine the developmental process for motives behind prosocial behaviors.

Differences Between Japanese and U.S. Children's Performance on "Zoo U": A Game-Based Social Skills Assessment.

OBJECTIVE: The purpose of this study was to test whether and how performance on a digital game-based social skills assessment tool, "Zoo U" (3C Institute, Durham, NC), differed for children in the United States and Japan across six core social skills. MATERIALS AND METHODS: "Zoo U" was administered to 497 third and fourth grade children from the United States and Japan (46 percent Japanese) by teachers and researchers, respectively. U.S. children received the original version of "Zoo U," and Japanese children received a fully translated Japanese version of the program. Scoring of each of the six social skills is built into the "Zoo U" software, with specific scoring algorithms for each grade level that provide both a continuous scale score and cutoffs for three distinct performance categories: high, average, and low. RESULTS: A multivariate analysis of variance (MANOVA) was conducted to assess differences by cultural group on each of the six continuous social skill scores, controlling for gender and grade level. Results revealed significant differences on four of the six skills in expected directions. Chi-squared and odds ratios analyses were then conducted on the assignment of children into each of the performance categories by cultural group, revealing additional nuance to the cultural differences identified in the MANOVA consistent with existing literature. CONCLUSIONS: We were able to replicate known cultural differences between U.S. and Japanese children with a simple direct translation of a Web-based social skills assessment game, "Zoo U." Our results provide preliminary support for the potential of game-based assessment methods to provide efficient and valid social skill assessments to children around the world.

Germin-like protein gene family of a moss, Physcomitrella patens, phylogenetically falls into two characteristic new clades.

We identified 77 EST clones encoding germin-like proteins (GLPs) from a moss, Physcomitrella patens in a database search. These Physcomitrella GLPs ( PpGLP s) were separated into seven groups based on DNA sequence homology. Phylogenetic analysis showed that these groups were divided into two novel clades clearly distinguishable from higher plant germins and GLPs, named bryophyte subfamilies 1 and 2. PpGLPs belonging to bryophyte subfamilies 1 lacked two cysteines at the conserved positions observed in higher plant germins or GLPs. PpGLPs belonging to bryophyte subfamily 2 contained two cysteines as observed in higher plant germins and GLPs. In bryophyte subfamily 1, 12 amino acids, in which one of two cysteines is included, were deleted between boxes A and B. Further, we determined the genomic structure of all of seven PpGLP genes. The sequences of PpGLP s of bryophyte subfamily 1 contained one or two introns, whereas those of bryophyte subfamily 2 contained no introns. Other GLPs from bryophytes, a liverwort GLP from Marchantia polymorpha , and two moss GLPs from Barbula unguiculata and Ceratodon purpureus also fell into bryophyte subfamily 1 and bryophyte subfamily 2, respectively. No higher plant germins and GLPs were grouped into the bryophyte subfamilies 1 and 2 by our analysis. Moreover, we revealed that PpGLP6 had manganese-containing extracellular superoxide dismutase activity. These results indicated that bryophyte possess characteristic GLPs, which phylogenetically are clearly distinguishable from higher plant GLPs.

Salt stress-induced dissociation from cells of a germin-like protein with Mn-SOD activity and an increase in its mRNA in a moss, Barbula unguiculata.

To estimate the physiological roles of a germin-like protein (BuGLP) with Mn-SOD activity isolated newly from a moss, Barbula unguiculata, BuGLP mRNA levels during cell growth and the effects of methyl viologen and salt stress were studied. BuGLP mRNA levels were at their peak during the exponential phase of growth and decreased thereafter, but SOD activity was held at the same level as that during the exponential phase. When methyl viologen was present as a generator of superoxide the amount of BuGLP transcripts decreased, but that of SOD activity of BuGLP bound to the cell wall was not affected. The addition of NaCl to the cells during the logarithmic phase increased both the BuGLP mRNA levels and total SOD activity of BuGLP, but decreased the SOD activity bound to the cell wall due to release of most of the SOD activity into the medium. On the other hand, the addition of NaCl to the cells during the stationary phase hardly affected BuGLP mRNA levels or SOD activity levels bound to the cell wall. These results suggest that the induction of BuGLP gene by salt stress is caused by dissociation of BuGLP protein from the cell wall into the medium in the cells during the logarithmic phase.