When expression of more than one gene is required in cells, bicistronic or multicistronic expression vectors have been used. Among various strategies employed to construct bicistronic or multicistronic vectors, an internal ribosomal entry site (IRES) has been widely used. Due to the large size and difference in expression levels between genes before and after IRES, however, a new strategy was required to replace IRES. A self-cleaving 2A peptide could be a good candidate to replace IRES because of its small size and high cleavage efficiency between genes upstream and downstream of the 2A peptide. Despite the advantages of the 2A peptides, its use is not widespread because (i) there are no publicly available cloning vectors harboring a 2A peptide gene and (ii) comprehensive comparison of cleavage efficiency among various 2A peptides reported to date has not been performed in different contexts. Here, we generated four expression plasmids each harboring different 2A peptides derived from the foot-and-mouth disease virus, equine rhinitis A virus, Thosea asigna virus and porcine teschovirus-1, respectively, and evaluated their cleavage efficiency in three commonly used human cell lines, zebrafish embryos and adult mice. Western blotting and confocal microscopic analyses revealed that among the four 2As, the one derived from porcine teschovirus-1 (P2A) has the highest cleavage efficiency in all the contexts examined. We anticipate that the 2A-harboring cloning vectors we generated and the highest efficiency of the P2A peptide we demonstrated would help biomedical researchers easily adopt the 2A technology when bicistronic or multicistronic expression is required.

Background The relationship of LPA single nucleotide polymorphisms (SNPs), apolipoprotein(a) isoforms and lipoprotein(a) [Lp(a)] levels with major adverse cardiovascular (MACE) events in different ethnic groups is not well known. Methods LPA SNPs, apolipoprotein(a) isoforms, Lp(a) and oxidized phospholipids on apolipoprotein B-100 (OxPL-apoB) levels were measured in 1792 Black, 1030 White and 597 Hispanic subjects enrolled in the Dallas Heart Study. Their interdependent relationships and prospective association with MACE after median 9.5-year follow-up were determined. Results LPA SNP rs3798220 was most prevalent in Hispanics (42.38%), rs10455872 in Whites (14.27%) and rs9457951 in Blacks (32.927%). The correlation of each of these SNPs with the major apolipoprotein(a) isoform size was highly variable and in different directions among ethnic groups. In the entire cohort, Cox regression analysis with multivariable adjustment revealed that quartiles 4 of Lp(a) and OxPL-apoB were associated with hazard ratios (HR) (95% CI) for time to MACE of 2.35 (1.50-3.69), p<0.001) and 1.89 (1.26-2.84), p=0.003), respectively, versus quartile 1. Addition of the major apolipoprotein(a) isoform and the 3 LPA SNPs to these models attenuated the risk, but significance was maintained for both Lp(a) and OxPL-apoB. Evaluating specific ethnic groups, in Blacks Lp(a) was a positive predictor and the size of the major apolipoprotein(a) isoform and inverse predictor, in Whites the size of the major apolipoprotein(a) isoform was an inverse predictor and in Hispanics OxPL-apoB was a predictor of time to MACE. Conclusion The prevalence and association of LPA SNPs with size of apolipoprotein(a) isoforms, Lp(a) and OxPL-apoB levels are highly variable and ethnicity-specific. The relationship to MACE is best explained by elevated plasma Lp(a) or OxPL-apoB levels, despite significant ethnic differences in LPA genetic markers.

Background: While chronic β-Hydroxy β-Methylbutyrate (HMB) supplementation (≥ 2 wk) lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK), lactate dehydrogenase (LDH), muscle soreness, and maximal voluntary contraction (MVC).

Background/Aims : Behcet's disease (BD) is a systemic disorder associated with a characteristic vasculitis that can involve both veins and arteries of all sizes. Endothelial activation or injury is a characteristic feature of BD. Endothelial dysfunction is widely regarded as being the initial lesion in the development of atherosclerosis. The carotid artery intima-media thickness (IMT) is a widely accepted marker of subclinical atherosclerosis. We aimed to determine the carotid IMT in BD patients with using high-resolution B-mode Doppler ultrasonography.Methods : We studied 40 patients (24 males, mean age: 39.1±8.5 years) who were diagnosed by the international diagnostic criteria of Behcet's disease and 20 healthy controls (13 males, mean age: 40.2±5.1 years), and the two groups were matched by age and gender. No subject in either group had a history of atherosclerosis or its complications. The clinical data, including the age of onset, the duration of disease, a history of medication, the activity score and the laboratory data were analyzed.Results : The carotid IMT in the BD group was significantly higher than that in the control group (0.71±0.22 mm vs. 0.59±0.09 mm, respectively, p<0.01). Cardiac and major vessel involvements were not identified in the BD group. However, minor vascular involvements were documented in 2 patients with deep vein thrombosis, in 4 patients with superficial thrombophlebitis and in 2 patients with pseudoaneurysm. The carotid IMT in the patients with posterior uveitis or retinal vasculitis was higher than that of the patients without these findings (0.85±0.21 mm vs. 0.64±0.10 mm, respectively, p=0.007), but there was no difference of the IMT according to minor vascular involvement.Conclusions : Despite that there was no significant cardiovascular involvement in the BD patients, the carotid IMT was significantly higher in the BD patients as compared with the healthy controls.

Background and Objectives：This study was designed to examine whether mesenchymal stem cells (MSCs) transduced with Akt are more resistant to apoptosis, and enhance cardiac repair, following the transplantation into infarcted porcine myocardium. Materials and Methods：The MSCs were separated and genetically engineered using ex-vivo myr-Akt-adenoviral gene transfer. The MSCs were delivered by intracoronary injection into infarcted porcine myocardium [group I (control: n=8), media only; group II (n=8), MSCs only; group III (n=8), MSCs modified with Akt]. Myocardial SPECT was performed before and 4 weeks after the MSC transplantation, with the pigs sacrificed for immunocytochemical staining and histological analyses for apoptosis and fibrosis. Results：The left ventricular ejection fractions (LVEF) were 44.7±16.6, 35.9±10.0 and 41.1±7.9% at first (each n=8), which changed to 29.7±8.5, 39.0±9.5 and 60.4±16.6% at 4 weeks after the MSC implantation in groups I, II and III, respectively. The myocardial infarction (MI) area changed from 17.6±9.2, 35.0±11.8 and 24.3±11.2% to 19.6±10.1, 27.2±13.9 and 7.4±5.3% in groups I, II and III, respectively. Transplantation of 1×10 7 cells into group II increased the ΔLVEF (-15.0±15.3 vs. 3.0±4.3%, n=8 in each, p=0.016) and decreased the ΔMI area (2.1±0.9 vs. 5.6±3.1%, n=8 in each, p=0.04) compared to those of the control group, and these changes were more significant in the ΔLVEF (19.3±15.7%, p=0.006) and ΔMI area (-16.4±6.1%, p=0.037) of group III. Conclusion：MSCs transduced with Akt enhance the repair of the injured area, prevent remodeling and restore systolic performance in infarcted porcine myocardium. (Korean Circulation J 2005;35:734-741) KEY WORDS：Myocardial infarction；Stem cells；Ventricular remodeling.서 론 최근 관상동맥질환은 선진국뿐만 아니라 한국에서도 급증 하여 성인 사망률의 주요한 원인이 되고 있다. 이러한 관상 동맥질환의 치료는 경피적 관상동맥 풍선 확장술과 스텐트 등으로 치료가 가능해 졌지만, 급성 심근경색증의 후유증으 논문접수일：2005년 5월 18일 수정논문접수일：2005년 9월 2일 심사완료일：2005년 9월 12일 교신저자：정명호, 501-757 광주광역시 동구 학동 8번지 전남대학교병원 심장센터, 전남대학교 의과학연구소 전화：(062) 220-6243·전송：(062) 228-7174·E-mail：myungho@chollian.net

BackgroundWe investigated the prevalence of latent tuberculosis infection (LTBI) among the health care workers (HCWs) and analyzed its risk factors in South Korea.MethodsA standard questionnaire regarding the baseline demographics and risk factors for LTBI was given to each participant and tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (QFT-GIT) assay, and chest radiography were performed.ResultsA total of 493 participants, 152 (30.8%) doctors and 341 (69.2%) nurses were enrolled in eight tertiary referral hospitals. The mean age of the subjects was 30.6 years old, and 383 (77.7%) were female. Of the 152 doctors, 63 (41.4%) and 36 (23.7%) were positive by TST and by QTF-GIT, respectively, and among the 341 nurses, 119 (34.9%) and 49 (14.4%) had positive TST and QFT-GIT results, respectively. Overall, the agreement between the two tests was 0.22 by the chance corrected proportional agreement rate (kappa coefficient) in 493 subjects. Experience of working in tuberculosis (TB)-related departments was significantly associated with positive LTBI test results by QFT-GIT assay, not by TST. In multivariate analysis, only age was independently associated with increased risk of a positive TST result, while age and experience of working in TB-related departments (odds ratio, 2.29; 95% confidence interval, 1.01-5.12) were independently associated with increased risk of a positive QFT-GIT result.ConclusionA high prevalence of LTBI was found among South Korean HCWs. Considering the association between the experience of working in TB-related departments and high risk of LTBI, QFT-GIT may be a better diagnostic test for LTBI than TST in HCWs.

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tent implantation is an effective treatment for coronary artery stenosis and is a commonly used strategy in percutaneous coronary intervention (PCI). At the present time, 2 drug-eluting stents (DES: sirolimus and paclitaxel) have made it into large clinical trials and seem to have fundamentally changed the treatment of coronary artery disease. DES are successful in most patients in preventing restenosis as compared with bare metal stents (BMS). [1][2][3][4][5] There are reports of the superiority of the sirolimuseluting stent (SES) over the paclitaxel-eluting stent (PES) in certain clinical groups such as those with diabetes or small vessels. [6][7][8] However, in truly head-to-head comparisons, such as the REALITY trial, there were no differences in the rate of binary restenosis and major adverse cardiac events (MACE) between the 2 types. 9 The importance of the angiographic endpoint of lower in-stent late luminal loss as representative of clinical events has been doubted and there are only a few published studies on the patterns of DES use in clinical practice. 10,11 Recent trials of DES in acute myocardial infarction However, there are growing questions about the actual usefulness of DES, because of the increased incidence of thrombosis and death in DES cases compared with BMS during follow-up. [15][16][17] Moreover, because there is more chance of a thrombotic condition in AMI, many clinicians have questioned the incidence of MACE and stent thrombosis in DES-implanted AMI patients during real-life clinical Circ J 2008; 72: 392 -398