Geographical distribution of bat flies (Diptera: Nycteribiidae and Streblidae), including two new records,Nycteribia allotopa and N. formosana,collected from bats (Chiroptera: Rhinolophidae and Vespertilionidae) in the Republic of Korea

As part of the 65^th Medical Brigade, U.S. Army, arthropod‐borne disease surveillance program and in collaboration with the Korea National Institute of Biological Resources (NIBR), bats were captured from caves and abandoned mines in the Republic of Korea. A total of 39 adult bat flies including five species of Nycteribiidae [Penicillidia jenynsii, Nycteribia parvula, N. formosana, N. allotopa mikado, and an unidentified species of Nycteribia (N. cf. formosana)], and one species of Streblidae, Brachytarsina kanoi, were collected from bats belonging to two families, Rhinolophidae and Vespertilionidae. This is the first report of N. allotopa mikado and N. formosana from the Republic of Korea.     

Antifungal property of dihydrodehydrodiconiferyl alcohol 9′-O-β-d-glucoside and its pore-forming action in plasma membrane of Candida albicans

The aims of this study were to investigate the antifungal activity as a bioactive property of dihydrodehydrodiconiferyl alcohol 9′-O-β-d-glucoside (DDDC9G) and the mode of action(s) involved in its effect. Antifungal susceptibility testing showed that DDDC9G possessed potent antifungal activities toward various fungal strains with almost no hemolytic effect. To understand the antifungal mechanism(s) of DDDC9G, we conducted the following experiments in this study using Candida albicans. Fluorescence experiments using the probes, 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) and propidium iodide suggested that DDDC9G perturbed the fungal plasma membrane. Consecutively, the analysis of the transmembrane electrical potential (ΔΨ) with 3, 3′-dipropylthiadicarbocyanine iodide [DiSC₃(5)] and bis-(1, 3-dibutylbarbituric acid) trimethine oxonol [DiBAC₄(3)] indicated that DDDC9G induced membrane-depolarization. Furthermore, model membrane studies were performed with rhodamine-labeled giant unilamellar vesicles (GUVs), calcein encapsulating large unilamellar vesicles (LUVs), and FITC-dextran (FD) loaded LUVs. These results demonstrated that the antifungal effects of DDDC9G upon the fungal plasma membrane were through the formation of pores with the radii between 0.74 nm and 1.4 nm. Finally, in three dimensional (3D) flow cytometric contour plots, a reduced cell size was observed as a result of osmolarity changes from DDDC9G-induced structural and functional membrane damages. Therefore, the present study suggests that DDDC9G exerts its antifungal effect by damaging the membrane through pore formation in the fungal plasma membrane.     

Relationships between digit ratio (2D:4D), ACE gene polymorphism, and physical performance in the Korean population

The aim of this study is to assess the possible contribution of the ratio of the length of second-to-fourth digits (2D:4D) and angiotensin-converting enzyme (ACE) gene variants to differences in elite athletic performance. We have therefore examined a population-based association study in 151 Korean elite athletes and 183 controls with the digit ratio (2D:4D) and I/D polymorphism of ACE gene. Genotype distribution of the ACE gene showed no significant deviation from Hardy-Weinberg equilibrium in both groups of elite athletes and controls. No statistically significant difference in the distribution of the ACE genotype frequency was observed between the elite athletes and control groups. In contrast, the digit ratio (2D:4D) appeared to be statistically significant difference between the elite athletes and control groups (p<0.001), although there was no genotype effect of the ACE gene on the digit ratio (2D:4D) in this survey. Thus, our data are consistent with hypothesis that digit ratios, as markers for prenatal testosterone action may provide a significant effect on elite athlete status, although larger sample sizes functional studies are necessary to further substantiate these findings.     

An investigation of a mouse model to estimate the potency of the diphtheria component in vaccines

A mouse model to estimate the potency of the diphtheria toxoid components in vaccines using Vero cells to detect the neutralizing antibodies in the sera from immunized mice is described. The results obtained with this mouse model correlated significantly with those obtained in the lethal challenge test in guinea-pigs. For this reason it is suggested that the potency test in guinea-pigs be replaced by this mouse model because a considerable reduction in the number of animals used and costs can be achieved by the introduction of this mouse test for the routine control of the potency of the diphtheria component of vaccines.