Thermal comfort zones in the Vietnamese

Thermally comfortable zones in Vietnamese were investigated during winter in Hanoi. The subjects were 21 males (age: 19.7 +/- 0.4 yrs; height: 165 +/- 1.5 cm; body mass: 55.1 +/- 1.1 kg) and 19 females (age: 19.7 +/- 0.4 yrs; height; 155.6 +/- 1.7 cm; body mass: 45.6 +/- 1.3 kg). Each participant entered singly the climatic chamber controlled at 22 degrees C and 40% RH. After 20 min rest, the participant was requested to indicate on a 7-point scale (Table 1) how he or she felt to the room temperature given. Then, the room temperature increased by 1 degrees C over 10 min every 20 min. Just before the rise of the room temperature, the participant judged his or her thermal sensation. More than 90% of the participants felt 24-29 degrees C of the room temperature as "slightly cool", "neutral" and "slightly warm" (Table 2). We defined these sensations as "thermally comfort". These thermally comfortable zones were quite higher than those (20-24 degrees C) recommended by ISO-7730 (1994). We discussed these discrepancies in terms of higher establishment of thermoregulatory set-point in the Vietnamese.     

Cytotoxic screening of medicinal and edible plants in Okinawa,Japan, and identification of the main toxic constituent of Rhodea japonica (Omoto)

The cytotoxic activity of ethanol extracts from 53 parts of 36 species of medicinal and edible plants cultivated in Okinawa was measured by using K562 human leukemia cells by a flow cytometric method. Two extracts from Rhodea japonica and Hypericum chinense were cytotoxic at a concentration of 10 microg/ml. The main cytotoxic constituent of Rhodea japonica was isolated and identified to be rhodexin A, which has been isolated as a cardetonic agent of the plant. The IC(50) value for rhodexin A against the growth of K562 cells was 19 nM, this activity being much stronger than that of ouabain (IC(50), 60 nM).     

The composition,structure and stability of a group II chaperonin are temperature regulated in a hyperthermophilic archaeon

The hyperthermoacidophilic archaeon Sulfolobus shibatae contains group II chaperonins, known as rosettasomes, which are two nine-membered rings composed of three different 60 kDa subunits (TF55 alpha, beta and gamma). We sequenced the gene for the gamma subunit and studied the temperature-dependent changes in alpha, beta and gamma expression, their association into rosettasomes and their phylogenetic relationships. Alpha and beta gene expression was increased by heat shock (30 min, 86 degrees C) and decreased by cold shock (30 min, 60 degrees C). Gamma expression was undetectable at heat shock temperatures and low at normal temperatures (75-79 degrees C), but induced by cold shock. Polyacrylamide gel electrophoresis indicated that in vitro alpha and beta subunits form homo-oligomeric rosettasomes, and mixtures of alpha, beta and gamma form hetero-oligomeric rosettasomes. Transmission electron microscopy revealed that beta homo-oligomeric rosettasomes and all hetero-oligomeric rosettasomes associate into filaments. In vivo rosettasomes were hetero-oligomeric with an average subunit ratio of 1alpha:1beta:0.1gamma in cultures grown at 75 degrees C, a ratio of 1alpha:3beta:1gamma in cultures grown at 60 degrees C and a ratio of 2alpha:3beta:0gamma after 86 degrees C heat shock. Using differential scanning calorimetry, we determined denaturation temperatures (Tm) for alpha, beta and gamma subunits of 95.7 degrees C, 96.7 degrees C and 80.5 degrees C, respectively, and observed that rosettasomes containing gamma were relatively less stable than those with alpha and/or beta only. We propose that, in vivo, the rosettasome structure is determined by the relative abundance of subunits and not by a fixed geometry. Furthermore, phylogenetic analyses indicate that archaeal chaperonin subunits underwent multiple duplication events within species (paralogy). The independent evolution of these paralogues raises the possibility that chaperonins have functionally diversified between species.     

Ethylene glycol bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) inhibits the growth of Escherichia coli at alkaline pH

The growth of Escherichia coli was inhibited by ethylene glycol bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) in a medium of initial pH 8.8. The growth inhibition was reversed by the addition of CaCl(2). E. coli could grow in the presence of EGTA at pH values below 8. The concentration of free calcium ions increases with a decrease in medium pH because of a decrease in the calcium binding capacity of EGTA. So, although the results suggest that calcium ions are essential for the growth of E. coli, the minimum concentration required is very low.     

Development of a highly sensitive high-performance liquid chromatographic method for measuring an anticancer drug, UCN-01, in human plasma or urine

We have established a highly sensitive high-performance liquid chromatographic method for the determination of an anticancer drug, UCN-01, in human plasma or urine. Using a fluorescence detector set at an excitation wavelength of 310 nm and emission monitored at 410 nm, there was a good linearity for UCN-01 in human plasma (r=0.999) or urine (r=0.999) at concentrations ranging from 0.2 to 100 ng/ml or 1 to 400 ng/ml, respectively. For intra-day assay, in plasma samples, the precision and accuracy were 1.8% to 5.6% and −10.0% to 5.2%, respectively. For inter-day assay, the precision and accuracy were 2.0% to 18.2% and 2.4% to 10.0%, respectively. In urine samples, the intra- and inter-day precision and accuracy were within 3.9% and ±2.7%, respectively. The lower limit of quantification (LLOQ) was set at 0.2 ng/ml in plasma and 1 ng/ml in urine. UCN-01 in plasma samples was stable up to two weeks at −80°C and also up to four weeks in urine samples. This method could be very useful for studying the human pharmacokinetics of UCN-01.     

DNA barcoding reveals 24 distinct lineages as cryptic bird species candidates in and around the Japanese Archipelago

DNA barcoding using a partial region (648 bp) of the cytochrome c oxidase I (COI) gene is a powerful tool for species identification and has revealed many cryptic species in various animal taxa. In birds, cryptic species are likely to occur in insular regions like the Japanese Archipelago due to the prevention of gene flow by sea barriers. Using COI sequences of 234 of the 251 Japanese‐breeding bird species, we established a DNA barcoding library for species identification and estimated the number of cryptic species candidates. A total of 226 species (96.6%) had unique COI sequences with large genetic divergence among the closest species based on neighbour‐joining clusters, genetic distance criterion and diagnostic substitutions. Eleven cryptic species candidates were detected, with distinct intraspecific deep genetic divergences, nine lineages of which were geographically separated by islands and straits within the Japanese Archipelago. To identify Japan‐specific cryptic species from trans‐Paleartic birds, we investigated the genetic structure of 142 shared species over an extended region covering Japan and Eurasia; 19 of these species formed two or more clades with high bootstrap values. Excluding six duplicated species from the total of 11 species within the Japanese Archipelago and 19 trans‐Paleartic species, we identified 24 species that were cryptic species candidates within and surrounding the Japanese Archipelago. Repeated sea level changes during the glacial and interglacial periods may be responsible for the deep genetic divergences of Japanese birds in this insular region, which has led to inconsistencies in traditional taxonomies based on morphology.     

The HIV-1 Gp120/CXCR4 Axis Promotes CCR7 Ligand-Dependent CD4 T Cell Migration: CCR7 Homo- and CCR7/CXCR4 Hetero-Oligomer Formation as a Possible Mechanism for Up-Regulation of Functional CCR7

During human immunodeficiency virus (HIV) infection, enhanced migration of infected cells to lymph nodes leads to efficient propagation of HIV-1. The selective chemokine receptors, including CXCR4 and CCR7, may play a role in this process, yet the viral factors regulating chemokine-dependent T cell migration remain relatively unclear. The functional cooperation between the CXCR4 ligand chemokine CXCL12 and the CCR7 ligand chemokines CCL19 and CCL21 enhances CCR7-dependent T cell motility in vitro as well as cell trafficking into the lymph nodes in vivo. In this study, we report that a recombinant form of a viral CXCR4 ligand, X4-tropic HIV-1 gp120, enhanced the CD4 T cell response to CCR7 ligands in a manner dependent on CXCR4 and CD4, and that this effect was recapitulated by HIV-1 virions. HIV-1 gp120 significantly enhanced CCR7-dependent CD4 T cell migration from the footpad of mice to the draining lymph nodes in in vivo transfer experiments. We also demonstrated that CXCR4 expression is required for stable CCR7 expression on the CD4 T cell surface, whereas CXCR4 signaling facilitated CCR7 ligand binding to the cell surface and increased the level of CCR7 homo- as well as CXCR4/CCR7 hetero-oligomers without affecting CCR7 expression levels. Our findings indicate that HIV-evoked CXCR4 signaling promotes CCR7-dependent CD4 T cell migration by up-regulating CCR7 function, which is likely to be induced by increased formation of CCR7 homo- and CXCR4/CCR7 hetero-oligomers on the surface of CD4 T cells.     

Histological and Transcriptomic Analysis of Adult Japanese Medaka Sampled Onboard the International Space Station

To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment (“Medaka Osteoclast”) was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation–reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation.