Change of accreditation standards of medical schools by the Korean Institute of Medical Education and Evaluation from 2000 to 2019.

It aimed to provide the change of accreditation standards of medical schools in Korea by the Korean Institute of Medical Education and Evaluation (KIMEE) from 2000 to 2019. Specifically, the following was explained: the development process, setting principle and direction, items of evaluation, characteristics of the standards, and validity test of 4 cycles. The first cycle of accreditation (2000-2005) was a process to secure the minimum requirement of the educational environment. The evaluation criteria emphasized the evaluation of the core elements of medical education, including facilities and human resources. The second cycle of accreditation (2007-2010) was a process in which the university emphasized its commitment to social accountability and the pursuit of excellence in medical education. It raised the importance of the qualitative standard for judging the contents and fidelity of education. In the post-2nd cycle of accreditation (2012-2018), the certification criteria were developed to standardize the educational environment and educational programs and to use them in the development of curriculum, to continually improve the quality of basic medical education. The ASK2019 accreditation aimed at qualitative evaluation following the World Federation of Medical Education's accreditation criteria to reach the international level of basic medical education, which stresses the student-centered curriculum, communication with the society, and evaluation through whole basic medical education course. KIMEE has developed the basic medical education evaluation and certification system step by step as above. Understanding the previous process will help to develop the accreditation criteria of medical school in Korea.

Inhibitory modulation of ATP-sensitive potassium channels by gallate-ester moiety of (-)-epigallocatechin-3-gallate.

(-)-Epigallocatechin-3-gallate (EGCG), a major polyphenolic substance found in green tea, is well recognized to be beneficial for human health. However, it is still controversial as to what dose of this compound is indeed good for human health. Though some recent studies have interestingly reported various beneficial effects of EGCG in cell culture system, however, plasma levels of EGCG attainable by oral regular intake in humans are normally in nanomolar range. However, potential side effects of EGCG when administered parenterally at higher concentration have not been thoroughly tested. Here, we evaluated the effect of EGCG on ATP-sensitive potassium (K(ATP)) channels expressed in Xenopus oocytes. EGCG inhibited the activity of the Kir6.2/SUR1 and Kir6.2DeltaC36 channels with IC(50) of 142+/-37 and 19.9+/-1.7microM, respectively. Inhibition of EGCG was also observed in Kir6.2/SUR2A or Kir6.2/SUR2B channels. Notably, (-)-epicatechin-3-gallate (ECG), another major polyphenolic substance in green tea, was found to reduce the channel activity with greater potency than EGCG. In contrast to EGCG and ECG, which have the gallic acid-ester moiety in their own structures, (-)-epigallocatechin and (-)-epicatechin exhibited very weak inhibition of the K(ATP) channel. Collectively, these results suggest that the gallate-ester moiety of epicatechins may be critical for inhibiting the K(ATP) channel activity via the pore-forming subunit Kir6.2 and this may be a possible mechanism by which green tea extracts or EGCG may cause unexpected side effects at micromolar plasma level.

Anisomycin treatment enhances TRAIL-mediated apoptosis in renal carcinoma cells through the down-regulation of Bcl-2, c-FLIP(L) and Mcl-1.

Anisomycin is known to inhibit protein synthesis and induce ribotoxic stress. In this study, we investigated whether anisomycin treatment could modulate TRAIL-mediated apoptosis in human renal carcinoma Caki cells. We found that anisomycin treatment (10-15 nM) alone had no effect on the level of apoptosis, but a combination treatment of anisomycin and TRAIL significantly increased the level of apoptosis in human renal carcinoma (Caki, ACHN and A498), human glioma (U251MG), and human breast carcinoma (MDA-MB-361 and MCF7) cells. Anisomycin treatment led to the down-regulation of Bcl-2 expression at the transcriptional level, and the over-expression of Bcl-2 inhibited the apoptosis induced by the combination treatment of anisomycin and TRAIL. Furthermore, anisomycin treatment resulted in the down-regulation of c-FLIP(L) and Mcl-1 at the post-transcriptional level, and the over-expression of c-FLIP(L) and Mcl-1 blocked the induction of apoptosis caused by the combination treatment of anisomycin with TRAIL. In contrast, anisomycin treatment had no effect on the levels of TRAIL-mediated apoptosis in mouse kidney cells (TMCK-1) or normal human skin fibroblasts (HSF). Cumulatively, our study demonstrates that anisomycin treatment enhances TRAIL-mediated apoptosis through the down-regulation of Bcl-2, c-FLIP(L) and Mcl-1 at the transcriptional or post-transcriptional level.

Role of (-)-epigallocatechin-3-gallate in cell viability, lipogenesis, and retinol-binding protein 4 expression in adipocytes.

(-)-Epigallocatechin-3-gallate (EGCG), a bioactive compound of green tea, is known to combat obesity by reducing the viability and lipid accumulation of adipocytes. In this study, we evaluated the mechanism and clinical relevance on those actions of EGCG. We measured the viability of 3T3-L1 preadipocytes and adipocytes by the 3-(4, 5-dimethylthiazol-2yl)-2, 5-diphenyltetrazolium bromide assay. Lipid accumulation was measured by Oil Red O staining. Intracellular accumulation of reactive oxygen species (ROS) was determined using a flow cytometer. Cellular glucose uptake was determined with 2-deoxy-[(3)H]-glucose. The protein levels of peroxisome proliferator-activated receptor (PPAR)-γ and adiponectin in 3T3-L1 adipocytes, as well as the protein level and secretion of plasma retinol-binding protein (RBP4) in human adipocytes, were measured by western blot. EGCG at concentrations higher than 10 µM induced ROS generation and decreased the viability and lipid accumulation of adipocytes. It also decreased the expression of PPAR-γ and adiponectin. At concentrations readily achievable in human plasma via green tea intake (≤10 µM), EGCG inhibited cellular glucose uptake and enhanced the expression and secretion of RBP4 in adipocytes. Pharmacological doses of EGCG showed cytotoxic effects in preadipocytes and adipocytes. EGCG-mediated glucose uptake inhibition in adipocytes may be clinically relevant and is probably linked to the increase in the expression and secretion of RBP4. Because secreted RBP4 from adipocytes inhibits muscular glucose uptake and enhance hepatic glucose output, the systemic effect of EGCG associated with its effect on RBP4 secretion should be further determined, as it may negatively regulate whole-body insulin sensitivity, contrary to general belief.

EGCG attenuates AMPA-induced intracellular calcium increase in hippocampal neurons.

We have investigated the protective effect of (-)-epigallocatechin gallate (EGCG) on alpha-amino-3-hydroxy-5-methyl-4-isoxazolo propionate (AMPA)-induced toxicity in cultured rat hippocampal neurons. Treatment of 24 h AMPA (10 microM) reduced the neuronal viability in both survival neuron counting and MTT reduction assay compared with control, with increase in cellular concentrations of hydrogen peroxide and malondialdehyde. These responses to AMPA were significantly blocked by co-treatments with EGCG (10 microM), which effect was very similar to the protective ability of a known antioxidant catalase (2000 U/ml). AMPA (50 microM) elicited the increase in intracellular calcium concentration ([Ca(2+)]i) on which EGCG significantly attenuated both peak amplitude and sustained nature of that [Ca(2+)]i increase in a dose-dependent manner. These data suggest that EGCG has a neuroprotective effect against AMPA through inhibition of AMPA-induced [Ca(2+)]i increase and consequent attenuation of reactive oxygen species production and lipid peroxidation as an antioxidant and a radical scavenger.

Cardiac expressions of natriuretic peptide mRNA following 4 weeks of head-down suspension in rat

BACKGROUND: Head-down suspension (HDS) of rats has evolved as a useful model for the simulation of a microgravity environment. Atrial natriuretic peptides (ANP) and brain natriuretic peptide (BNP) have been considered to comprise the cardiac natriuretic peptide family responsible for body fluid homeostasis and blood pressure control. However, little is known about the long-term responses and the simultaneous observations of both ANP and BNP following HDS. Therefore, this study was aimed to characterize the long-term adaptations of cardiac ANP and BNP syntheses to 4 weeks of HDS in rats. METHOD: Unanesthetized, unrestrained, male Sprague-Dawley rats were subjected to either a horizontal position (control rats) or a 45degree head-down tilt using the tail-traction technique (HDS rats). We determined the cardiac synthesis of natriuretic peptides as a expression of ANP and BNP mRNA, The expressions of natriuretic peptide mRNA were measured by reverse transcription-polymerase chain reaction with [32P]-dCTP following 4 weeks of HDS in the each cardiac chamber of control and HDS rats. RESULT: After 4 weeks of HDS, the expressions of ANP mRNA were decreased in the both right (p<0.05) and left atria. The ANP mRNA in the ventricles did not show significant changes compared with control values. In contrast with ANP, BNP mRNA was only decreased in the left atrium (p<0.05) and revealed the non-significant decreasing trend in the right ventricle. There were no remarkable changes of BNP mRNA expression compared with control rats in the both right atrium and left ventricle. CONCLUSION: Collectively, these results represent that the cardiac syntheses of natriuretic peptides following 4 weeks of HDS are attenuated to prevent any decrement of body fluid as a long-term adaptive response to simulated microgravity and ANP and BNP genes have the differential expression in the each chamber of the heart.