Hantaan virus surveillance targeting small mammals at Dagmar North Training Area, Gyeonggi Province, Republic of Korea, 2001-2005

In response to a hemorrhagic fever with renal syndrome case in November 2000, a seasonal rodent-borne disease surveillance program was initiated at Dagmar North Training Area (DNTA), Gyeonggi Province, Republic of Korea. From April 2001-December 2005, 1,848 small mammals were captured. Apodemus agrarius accounted for 92.5%, followed by Mus musculus (3.6%), Crocidura lasiura (2.1%), and Microtus fortis (1.1%). Three species of rodents were found to be antibody-positive (Ab+) for Hantaan virus (HTNV): A. agrarius (22.3%), M. musculus (9.1%), and M. fortis (5.0%). Ab+ rates for A. agrarius increased with increasing weight (age), except for those weighing <10 g. The peak HTNV transmission period in Korea coincided with the peak reproductive potential of A. agrarius during the fall (August/September) surveys. HTNV strains from DNTA were distinct from HTNV strains from the People's Republic of China. From these studies, more accurate risk assessments can be developed to better protect personnel from rodent-borne diseases.     

Inhibitory effect of Galgeun-tang on RANKL-induced osteoclast differentiation and bone loss in ovariectomized rats

Galgeun-tang (GGT) is a traditional Korean medication known to have a diaphoretic effect and to improve cerebral circulation. The aim of this study was to investigate the effects of GGT on osteoclast differentiation and bone loss in ovariectomized (OVX) rats compared to Galgeun-tang fermented by Bifidobacterium breve (designated as GFT). GGT significantly and dose-dependently inhibited the receptor activator for nuclear factor κB ligand (RANKL)-induced tartrate-resistant acid phosphatase (TRAP) activity and the formation of multinucleated osteoclasts in RAW264.7 cells. In addition, GGT significantly reduced RANKL-induced mRNA expression levels of TRAP, c-Src, and Cathepsin K. To examine the effect of GGT or GFT in OVX rats, we administered GGT or GFT (15 mL/kg/day) orally to OVX rats for 12 weeks. GGT administration significantly reduced body weight gain in OVX rats. GGT administration also significantly reduced total serum cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, and triglyceride levels in OVX rats. GFT administration significantly reduced serum LDL-cholesterol and triglyceride levels in OVX rats. Moreover, administration of GGT, but not GFT, significantly increased bone mineral density of the femur, which is normally decreased in OVX rats. In conclusion, these results suggest that GGT could have the potential to decrease ovariectomy-induced increases in body weight and lipid content and could prevent bone loss through its inhibitory effect on osteoclast differentiation.     

Amputee locomotion: Spring-like leg behavior and stiffness regulation using running-specific prostheses

Carbon fiber running-specific prostheses (RSPs) have allowed individuals with lower extremity amputation (ILEA) to participate in running. It has been established that as running speed increases, leg stiffness (K_leg) remains constant while vertical stiffness (K_vert) increases in able-bodied runners. The K_vert further depends on a combination of the torsional stiffnesses of the joints (joint stiffness; K_joint) and the touchdown joint angles. Thus, an increased understanding of spring-like leg function and stiffness regulation in ILEA runners using RSPs is expected to aid in prosthetic design and rehabilitation strategies. The aim of this study was to investigate stiffness regulation to various overground running speeds in ILEA wearing RSPs. Eight ILEA performed overground running at a range of running speeds. K_leg, K_vert and K_joint were calculated from kinetic and kinematic data in both the intact and prosthetic limbs. K_leg and K_vert in both the limbs remained constant when running speed increased, while intact limbs in ILEA running with RSPs have a higher K_leg and K_vert than residual limbs. There were no significant differences in K_ankle, K_knee and touchdown knee angle between the legs at all running speeds. Hip joints in both the legs did not demonstrate spring-like function; however, distinct impact peaks were observed only in the intact leg hip extension moment at the early stance phase, indicating that differences in K_vert between limbs in ILEA are due to attenuating shock with the hip joint. Therefore, these results suggest that ILEA using RSPs has a different stiffness regulation between the intact and prosthetic limbs during running.     

Differential toxicity and accumulation of inorganic and methylated arsenic in rice

Background and aims

Efficient accumulation of arsenic (As) in rice (Oryza sativa L.) poses a potential health risk to rice consumers. The aim of this study was to investigate the mechanisms of uptake, transport and distribution of inorganic arsenic (As_i) and dimethylarsinic acid (DMA) in rice plants.

Methods

Rice was exposed to As_i (As(V)) and DMA in hydroponics. High-performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and synchrotron X-ray fluorescence (SXRF) microprobe were used to determine As concentration and the in situ As distribution.

Results

DMA induced abnormal florets before flowering and caused a sharp decline in the seed setting rate after flowering compared to As_i. Rice grains accumulated 2-fold higher DMA than As_i. The distribution of As_i concentration (root?>?leaf?>?husk?>?caryopsis) in As(V) treatments was different from that of the DMA concentration (caryopsis?>?husk?>?root?≥?leaf) in DMA treatments. SXRF showed that As_i mainly accumulated in the vascular trace of caryopsis with limited distribution to the endosperm, whereas DMA was observed in both tissues.

Conclusions

DMA tended to accumulate in caryopsis and induced higher toxicity to the reproductive tissues resulting in markedly reduced grain yield, whereas As_i mainly remained in the vegetative tissues and had no significant effect on yield. DMA is more toxic than As_i to the reproductive tissues when both of them are at similar concentrations in nutrient solution.     

Ginkgetin induces apoptosis via activation of caspase and inhibition of survival genes in PC-3 prostate cancer cells

Ginkgetin is a natural biflavonoid isolated from leaves of Ginkgo biloba L. Though it was known to have anti-inflammatory, anti-influenza virus, anti-fungal activity, osteoblast differentiation stimulating activity and neuro-protective effects, the underlying antitumor mechanism of ginkgetin still remains unclear. Thus, in the present study, anti-cancer mechanism of ginkgetin was elucidated in human prostate cancer PC-3 cells. Ginkgetin suppressed the viability of PC-3 cells in a concentration-dependent manner and also significantly increased the sub-G1 DNA contents of cell cycle in PC-3 cells. Ginkgetin activated caspase-3 and attenuated the expression of survival genes such as Bcl-2, Bcl-x_L, survivin and Cyclin D1 at protein and mRNA levels. Consistently, pan-caspase inhibitor Z-DEVD-fmk blocked sub G1 accumulation and cleavages of PRAP and caspase 3 induced by ginkgetin in PC-3 cells. Overall, these findings suggest that ginkgetin induces apoptosis in PC-3 cells via activation of caspase 3 and inhibition of survival genes as a potent chemotherapeutic agent for prostate cancer treatment.     

Tricyclic thiazoles are a new class of angiogenesis inhibitors

Tricyclic thiazoleamine derivatives that were identified as hits in a screen against human umbilical vein endothelial cell proliferation were subjected to a structure–activity relationship study. Two structurally superimposable scaffolds—4H-thiochromeno[4,3-d]thiazol-2-amine and 5,6-dihydro-4H-benzo[6,7]cyclohepta[1,2-d]thiazol-2-amine derivatives—yielded low-micromolar inhibitors, and two among them 37 and 43 also exhibited antiangiogenic activity in an endothelial tube formation assay. Thus, 37 and 43 can serve as leads to develop a novel class of antiangiogenic agents.     

Prevention of Pseudomonas aeruginosa adhesion by electric currents

The process of controlling bacterial adhesion using an electric current deserves attention because of its ease of automation and environmentally friendly nature. This study investigated the role of electric currents (negative, positive, alternating) for preventing adhesion of Pseudomonas aeruginosa and achieving bacterial inactivation. Indium tin oxide (ITO) film was used as a working electrode to observe adhesion and inactivation under electric polarization. Electric current types were classified into negative, positive, and alternating current. The working electrode acted as a cathode or anode by applying a negative or positive current, and an alternating current indicates that the negative current was combined sequentially with the positive current. The numbers of adhered cells were compared under a flow condition, and the in situ behavior of the bacterial cells and the extent of their inactivation were also investigated using time-lapse recording and live/dead staining, respectively. The application of a negative current prevented bacterial adhesion significantly (～81% at 15.0 μA cm^?2). The positive current did not significantly inhibit adhesion (<20% at 15.0 μA cm^?2), compared to the nonpolarized case. The alternating current had a similar effect as the negative current on preventing bacterial adhesion, but it also exhibited bactericidal effects, making it the most suitable method for bacterial adhesion control.     

Steering signal transduction pathway towards cardiac lineage from human pluripotent stem cells: A review

In humans injured myocardium cannot avert the onset and progression of ventricular dysfunction because of limited regenerative ability of myocytes. Although limited renaissance of cardiomyocytes has been reported in human infarcted hearts, it is generally accredited that non-functional fibrous tissue replaces the dead myocardium. High cardiovascular morbidity and dearth of donor hearts warrant a constant hunt for radically different approach to treat heart failure. Pluripotent stem (PS) cells possess the ability to produce functional cardiomyocytes for clinical applications and drug development, which may provide the answer to this problem. Although progress has been made in differentiating human PS cells into cardiomyocytes, however, the in vitro differentiation of pluripotent cells into cardiomyocytes involves a poorly defined, inefficient and relatively non-selective process. A thorough understanding of signaling pathways would tender a roadmap for the streamlined development of in vitro cardiac differentiation strategies. The ability to obtain unlimited numbers of human cardiomyocytes would improve development of cell-based therapies for cardiovascular diseases, facilitate the study of cardiovascular biology and improve the early stages of drug discovery. Here in this review, we highlight the interacting endogenous cellular signals and their modulators involved in directing the human PSCs towards cardiac differentiation.