Angiopoietin-1 is an apoptosis survival factor for endothelial cells

AbstractWe examined the effect of angiopoietin-1 (Ang1) on apoptosis in human umbilical vein endothelial cells (HUVECs). Ang1 (5–1000 ng/ml) dose-dependently inhibited apoptosis under a serum-deprived state. A significant apoptotic inhibition occurred with as low as 50 ng/ml. Two hundred ng/ml of Ang1 inhibited to approximately 50% of the control apoptotic rates for 96 h. Furthermore, an augmented antiapoptotic effect of Ang1 by the addition of 20 ng/ml vascular endothelial growth factor was observed. This Ang1-induced strong antiapoptotic effect in endothelial cells is a novel and intriguing finding and could be an additional description of Ang1-induced direct biological function

Soluble vascular endothelial growth factor receptor-3 suppresses lymphangiogenesis and lymphatic metastasis in bladder cancer

Peer reviewe

Exchange Rates, Monetary Policies, and Macroeconomic Stability

Three aggregated stochastic models are developed which incorporate the major features of small open economy with structural changes in different stages of economic development. For Model 1 and 2, both analytic and empirical studies are made. The optimal policy mix between exchange rate and monetary policies for achieving economic stability is analyzed when the economy faces unexpected shocks on demand and supply. Empirical studies of Korea concludes that it is not optimal to absorb the external shocks through full accommodation of exchange rates. Since Model 3 assumes rigid price and capital mobility, exchange rates are no longer policy variables and determined within the system. The optimal monetary policies under those conditions are analytically derived but empirical studies are postponed since capital flows are under strict control in Korea

The Korean Currency Crisis and the IMF Program: An Insider's View

When the Korean currency crisis broke out, the IMF and many scholars blamed the whole crisis on Korea's internal problems. This paper, however, takes different stances from others towards the current crisis in several respects. We argue that both external and internal causes of the crisis should be equally addressed in explaining the current crisis. As external causes, we list the boom-and-bust cycle generated by the capital liberalization and asymmetries of financial liberalization policies. For the triggering factors of the Korean crisis, we emphasize sudden outflow of foreign capital, Southeast Asian crisis, as well as use of foreign reserves to support overseas branches of Korean banks. Regarding the IMF program, we criticize the IMF's macroeconomic policy and the complete financial opening policy. But unlike critics of the IMF program, we argue that the policy of structural reforms is necessary to strengthen the Korean economy and we should take this opportunity to implement it although such policy may exacerbate the severity of the crisis

The Positive Effects of Poria cocos Extract on Quality of Sleep in Insomnia Rat Models

Sleep disorders may have various causes and can incur mental and/or physical symptoms, and affect an individual’s quality of life. In this study, we confirm that the Poria cocos extract (PCET) can improve sleep quality and structure by promoting inhibitory neurotransmission via the γ-aminobutyric acid (GABA) type A (GABAA) receptors based on the mechanisms revealed in the experiment with superior cervical ganglion neurons. Pentobarbital-induced sleep tests were conducted in order to determine whether the PCET extract improves the sleep quality and structure in normal ICR mice. Sleep latency and duration were checked with the righting reflex. To simulate the state of awakening as well as a normal sleep state, caffeine was administered orally before the PCET diet. After oral gavage of PCET, sleep latency was decreased, and total sleep duration was increased in normal and caffeine-induced sleep disturbance state. In the ACTH-induced sleep disturbed models, administration of PCET significantly reduced the sleep latency and increased the non-REM sleep duration, which was analyzed in real-time EEG by implanting wireless electrodes in SD rats. PCET was found to improve the sleep quality under a normal sleep state through the GABAA receptor; it also promoted and improved the sleep quality and sleep structure in both the arousal activation state and stress-based sleep disturbance

Enhanced purification of fetal liver hematopoietic stem cells using SLAM family receptors

Although adult mouse hematopoietic stem cells (HSCs) have been purified to near homogeneity, it remains impossible to achieve this with fetal HSCs. Adult HSC purity recently has been enhanced using the SLAM family receptors CD150, CD244, and CD48. These markers are expressed at different stages of the hematopoiesis hierarchy, making it possible to highly purify adult HSCs as CD150+CD48–CD244– cells. We found that SLAM family receptors exhibited a similar expression pattern in fetal liver. Fetal liver HSCs were CD150+CD48–CD244–, and the vast majority of colony-forming progenitors were CD48+CD244–CD150– or CD48+CD244+CD150–, just as in adult bone marrow. SLAM family markers enhanced the purification of fetal liver HSCs. Whereas 1 (11%) of every 8.9 ThylowSca-1+lineage–Mac-1+ fetal liver cells gave long-term multilineage reconstitution in irradiated mice, 1 (18%) of every 5.7 CD150+CD48–CD41– cells and 1 (37%) of every 2.7 CD150+CD48–Sca-1+lineage–Mac-1+ fetal liver cells gave long-term multilineage reconstitution. These data emphasize the robustness with which SLAM family markers distinguish progenitors at different stages of the hematopoiesis hierarchy and enhance the purification of definitive HSCs from diverse contexts. Nonetheless, CD150, CD244, and CD48 are not pan-stem cell markers, as they were not detectably expressed by stem cells in the fetal or adult nervous system