Distribution of Non-tasters for Phenylthiocarbamide and High Sensitivity to Quinine Hydrochloride of the Non-tasters in Japanese

The percentage of non-tasters for phenylthiocarbamide in 915Japanese students was 9.4%. The thresholds of the edge and backof the tongue to quinine hydrochloride were significantly smallerin the non-tasters than in the tasters. The thresholds of anytongue portions to NaCl, acetic acid or sucrose did not differbetween the tasters and the non-tasters. Chem. Senses 22: 547–551,1997.     

Estimation of thermal sensation using PMV and SET under high air movement conditions

1. 1. Our previous experimental results showed the thermal sensation vote was much less than the values of PMV and SET^* at air velocities above 0.5 m/s.

2. 2. The method to modify SET^* is presented from the results of subjective experiments taking account of decrease in clo value of summer clothing and decrease in skin wettedness due to increased air velocity.

3. 3. Thermal resistance under increased air movement on a standard summer clothing ensemble was measured. Basic thermal insulation of the summer ensemble was reduced by 25% at air velocity of 1.0 m/s.

4. 4. Thirty-two subjects were exposed at operative temperatures of 27 and 30°C under 1 m/s air movement in order to determine the amount of skin diffusion. Measured evaporation heat loss from skin surface was much smaller at air velocity of 1 m/s than that predicted by SET^*.

5. 5. Estimated thermal sensation vote using modified SET^* agreed well with our previous experimental results under different air velocities for the same clothing.

Transcellular transport of West Nile virus-like particles across human endothelial cells depends on residues 156 and 159 of envelope protein

Background  

West Nile virus (WNV) causes viremia after invasion to the hosts by mosquito bite. Endothelial cells could play an important role in WNV spread from the blood stream into the central nervous system and peripheral tissues. Here, we analyzed the capacity of virus-like particles (VLPs) of the highly virulent NY99 6-LP strain (6-LP VLPs) and the low virulence Eg101 strain (Eg VLPs) to cross cultured human endothelial cells.     

A luminol chemiluminescence method for sensing histidine and lysine using enzyme reactions

The analysis of free amino acids in urine and plasma is useful for estimating disease status in clinical diagnoses. Changes in the concentration of free amino acids in foods are also useful markers of freshness, nutrition, and taste. In this study, the specific interaction between aminoacyl–tRNA synthetase (aaRS) and its corresponding amino acid was used to measure amino acid concentrations. Pyrophosphate released by the amino acid–aaRS binding reaction was detected by luminol chemiluminescence; the method provided selective quantitation of 1.0–30 μM histidine and 1.0–60 μM lysine.     

Dopamine D1-like receptor antagonist, SCH23390, exhibits a preventive effect on diabetes mellitus that occurs naturally in NOD mice

Dopamine receptors have five isoforms, termed D1-D5. The D1 and D5 receptors form the D1-like group that couples with the Gαs class of G proteins, while D2, D3 and D4 form the D2-like group that couples with the Gαi class of G proteins. In our previous studies, a D1-like-R antagonist, SCH23390, inhibited DC-mediated Th17 differentiation and exhibited preventive and therapeutic effects on experimental autoimmune encephalomyelitis (EAE) in mice. We herein demonstrate in the current study that in the pancreas obtained from NOD mice, islet infiltrates appear to be composed of mononuclear cells positive for IL-23R, one of the specific markers for Th17. Thereafter, NOD mice were orally administered SCH23390 from week 6 to week 26. At week 26, 67% and 25% of mice developed diabetes in the control and the SCH23390 groups, respectively (p < 0.05). A histological examination of SCH23390-treated mice exhibited a typical normal islet structure with no signs of periductal and perivascular infiltrates, whereas the islets from vehicle controls showed insulitis. In week 26, spleen cells were re-stimulated with anti-CD3 and anti-CD28 antibodies in vitro and exhibited an augmentation of IFNγ induction and the suppression of IL-17 induction in the SCH23390-treated mice. These findings indicate that antagonizing D1-like-R suppresses IL-17 expression, thereby leading to a decreased occurrence of NOD.     

Genomic DNA fragmentation in red blood cells of the bullfrog during metamorphosis

Red blood cells (RBC) of the bullfrog ( Rana catesbeiana ) contain larval-type hemoglobin (Hb) during the larval period. At the beginning of metamorphosis, RBC containing adult-type Hb appear and two types of RBC coexist in the systemic circulation. During the metamorphic climax, RBC with larval-type Hb disappear from the circulation and, simultaneously, RBC containing adult-type Hb begin to circulate. These two types of RBC were separated by Percoll density gradient centrifugation to examine the molecular size of the genomic DNA of each population. DNA fragmentation was detected only in new RBC with adult-type Hb that appeared in the systemic circulation and remained throughout post-metamorphic life. Semiquantification of DNA on agarose gel showed that the degree of DNA fragmentation was highest at the metamorphic climax. As the existence of DNA fragments suggested endonucleolytic cleavage, nuclease activity was examined by an activity gel system and in vitro circular plasmid DNA digestion assays. The latter revealed that both types of RBC possess endonucleolytic activity throughout the pre- and post-metamorphic periods. Assays of endogenous endonucleolytic activities under different divalent ionic conditions suggested that mobilization of intracellular Ca²⁺-Mg²⁺ induces genomic DNA fragmentation in adult-type RBC.     

Receptors on the brush border membrane of the insect midgut as determinants of the specificity of Bacillus thuringiensis delta-endotoxins.

To investigate the biochemical basis of the differences in the insecticidal spectrum of Bacillus thuringiensis insecticidal crystal proteins (ICPs), we performed membrane binding and toxicity assays with three different ICPs and three lepidopteran species. The three ICPs have different toxicity patterns in the three selected target species. Binding studies with these 125I-labeled ICPs revealed high-affinity saturable binding to brush border membrane vesicles of the sensitive species. ICPs with no toxicity against a given species did not bind saturably to vesicles of that species. Together with previous data that showed a correlation between toxicity and ICP binding, our data support the statement that differences in midgut ICP receptors are a major determinant of differences in the insecticidal spectrum of the entire lepidopteran-specific ICP family. Receptor site heterogeneity in the insect midgut occurs frequently and results in sensitivity to more than one type of ICP.