Transcriptional regulation of a gene is not always correlated with genetic information inherited from parents because the transcription of specific genes is often governed by the modification of chromatin structure. The study of transcriptional regulation by modifying chromatin structure is well-known as "epigenetics". Several methods involved in the modification of chromatin structure have been developed in the mammalian species during evolution. Among those methods, methylations of specific DNA region or histone are often used to control specific gene transcription. Therefore, understanding the activity of proteins involved in DNA or histone methylation is an initial step to control the transcriptional activity of a specific gene. Polycomb group (PcG) proteins were known to be repressors of transcription of a specific gene by creating and maintaining methylation or ubiquitination of the specific region of histone. Dependent on the target histone, the activity of PcG proteins effects on the development of specific lineage cells or the activity of specific cell types. In this review, the function, expression and activity of PcG proteins related with the development or activation of T cells are discussed.
Chromatin ; DNA ; Epigenomics ; Genes, vif ; Histone Code ; Histones ; Humans ; Methylation ; Parents ; Polycomb-Group Proteins ; Proteins ; T-Lymphocytes ; Ubiquitin ; Ubiquitination

Critical limb ischemia (CLI) is one of the most severe forms of peripheral artery diseases, but current treatment strategies do not guarantee complete recovery of vascular blood flow or reduce the risk of mortality. Recently, human bone marrow derived mesenchymal stem cells (MSCs) have been reported to have a paracrine influence on angiogenesis in several ischemic diseases. However, little evidence is available regarding optimal cell doses and injection frequencies. Thus, the authors undertook this study to investigate the effects of cell dose and injection frequency on cell survival and paracrine effects. MSCs were injected at 10⁶ or 10⁵ per injection (high and low doses) either once (single injection) or once in two consecutive weeks (double injection) into ischemic legs. Mice were sacrificed 4 weeks after first injection. Angiogenic effects were confirmed in vitro and in vivo, and M2 macrophage infiltration into ischemic tissues and rates of limb salvage were documented. MSCs were found to induce angiogenesis through a paracrine effect in vitro, and were found to survive in ischemic muscle for up to 4 weeks dependent on cell dose and injection frequency. In addition, double high dose and low dose of MSC injections increased vessel formation, and decreased fibrosis volumes and apoptotic cell numbers, whereas a single high dose did not. Our results showed MSCs protect against ischemic injury in a paracrine manner, and suggest that increasing injection frequency is more important than MSC dosage for the treatment CLI.
Animals* ; Bone Marrow* ; Cell Count ; Cell Survival ; Extremities* ; Fibrosis ; Humans ; In Vitro Techniques ; Ischemia* ; Leg ; Limb Salvage ; Macrophages ; Mesenchymal Stromal Cells* ; Mice ; Models, Animal* ; Mortality ; Peripheral Arterial Disease

PURPOSE: When flexor tendons are injuried in children, the management is difficult. There are needs to determine the periods of postoperative immobilization. MATERIALS AND METHODS: From April 1994 to March 1998, 40 patients younger than 16 years who had sustained flexor tendon lacerations in zone I or zone II of 52 digits were available for critical evaluation. The average postoperative follow-up period was 24 (range, 3-48) months. RESULTS: All profundus repairs in zone I achieved excellent or good function. Isolated profundus and combined profundus and superficialis repairs in zone II achieved comparable results which managed with a passive motion program immediately after operation (TAM=82%) or motion following immobilization for 3 weeks (TAM =79%) or 4 weeks (TAM=78%) . Immobilization for longer than 4 weeks which resulted in an appreciable deterioration of funtion (5 weeks: TAM=64%, 6 weeks: TAM=61%) . Digital motion following flexor tendon injuries treated with less than 4 weeks of immobilization or early motion was not significantly different. CONCLUSION: We could find no benefits of early mobilization protocols in children. Howerver, it does appear that it is important that postoperative immobilization not be continued beyond 4 weeks.
Child* ; Early Ambulation ; Follow-Up Studies ; Hand* ; Humans ; Immobilization ; Lacerations ; Tendon Injuries ; Tendons*

BACKGROUND/AIMS: Treatment of coronary in-stent restenosis (ISR) is still associated with a high incidence of recurrence. We aimed to compare the efficacy and safety of drug-eluting balloons (DEB) for the treatment of ISR as compared with conventional balloon angioplasty (BA) and drug-eluting stents (DES). METHODS: Between January 2006 and May 2012 a total of 177 patients (188 lesions, 64.1 ± 11.7 years old) who underwent percutaneous coronary intervention for ISR were retrospectively enrolled. Clinical outcomes were compared between patients treated with DEB (n = 58, 32.8%), conventional BA (n = 65, 36.7%), or DES (n = 54, 30.5%). The primary end point was a major adverse cardiac event (MACE), defined as a composite of cardiac death, myocardial infarction, and target lesion revascularization(TLR). RESULTS: Baseline characteristics were not different except for a history of previous MI, which was more frequent in patients treated by conventional BA or DES than in patients treated by DEB (40.0% vs. 48.1% vs. 17.2%, respectively, p = 0.002). The total incidences of MACEs were 10.7%, 7.4%, and 15.4% in patients treated by DEB, DES, or conventional BA, respectively (p > 0.05). TLR was more frequent in patients treated by conventional BA than in patients treated by DEB or DES, but this was not statistically significant (10.8% vs. 6.9% vs. 3.7%, p > 0.05 between all group pairs, respectively). CONCLUSIONS: This study showed that percutaneous coronary intervention using DEB might be a feasible alternative to conventional BA or DES implantation for treatment of coronary ISR. Further large-scaled, randomized study assessing long-term clinical and angiographic outcomes will be needed.
Angioplasty, Balloon* ; Coronary Restenosis ; Death ; Drug-Eluting Stents* ; Humans ; Incidence ; Myocardial Infarction ; Percutaneous Coronary Intervention ; Recurrence ; Retrospective Studies

BACKGROUND AND OBJECTIVES: We investigated the predictors of the recovery of depressed left ventricular ejection fraction (LVEF) in patients with moderate or severe left ventricular (LV) systolic dysfunction after acute myocardial infarction (MI). SUBJECTS AND METHODS: We analyzed 1307 patients, who had moderately or severely depressed LVEF (<45%) on echocardiography soon after acute MI and who underwent a follow-up echocardiography, among 27369 patients from the Korea Working Group on the Myocardial Infarction Registry. Patients were categorized into two groups according to recovery of LVEF: group I with consistently depressed LVEF (<45%) at the follow-up echocardiography and group II with a recovery of LVEF (> or =45%). RESULTS: Recovery of LV systolic dysfunction was observed in 51% of the subjects (group II, n=663; DeltaLVEF, 16.2+/-9.3%), whereas there was no recovery in the remaining subjects (group I, n=644; DeltaLVEF, 0.6+/-7.1%). In the multivariate analysis, independent predictors of recovery of depressed LVEF were as follows {odds ratio (OR) [95% confidence interval (CI)]}: moderate systolic dysfunction {LVEF > or =30% and <45%; 1.73 (1.12-2.67)}, Killip class I-II {1.52 (1.06-2.18)}, no need for diuretics {1.59 (1.19-2.12)}, non-ST-segment elevation MI {1.55 (1.12-2.16)}, lower peak troponin I level {<24 ng/mL, median value; 1.55 (1.16-2.07)}, single-vessel disease {1.53 (1.13-2.06)}, and non-left anterior descending (LAD) culprit lesion {1.50 (1.09-2.06)}. In addition, the use of statin was independently associated with a recovery of LV systolic dysfunction {OR (95% CI), 1.46 (1.07-2.00)}. CONCLUSION: Future contractile recovery of LV systolic dysfunction following acute MI was significantly related with less severe heart failure at the time of presentation, a smaller extent of myonecrosis, or non-LAD culprit lesions rather than LAD lesions.
Diuretics ; Echocardiography ; Follow-Up Studies ; Heart Failure ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Korea ; Multivariate Analysis ; Myocardial Infarction ; Prognosis ; Stroke Volume ; Troponin I

Human pluripotent stem cells (hPSCs) such as human embryonic stem cells (hESCs), induced pluripotent stem cells, and somatic cell nuclear transfer (SCNT)-hESCs can permanently self-renew while maintaining their capacity to differentiate into any type of somatic cells, thereby serving as an important cell source for cell therapy. However, there are persistent challenges in the application of hPSCs in clinical trials, where one of the most significant is graft rejection by the patient immune system in response to human leukocyte antigen (HLA) mismatch when transplants are obtained from an allogeneic (non-self) cell source. Homozygous SCNT-hESCs (homo-SCNT-hESCs) were used to simplify the clinical application and to reduce HLA mismatch. Here, we present a xeno-free protocol that confirms the efficient generation of neural precursor cells in hPSCs and also the differentiation of dopaminergic neurons. Additionally, there was no difference when comparing the HLA expression patterns of hESC, homo-SCNT-hESCs and hetero-SCNT-hESCs. We propose that there are no differences in the differentiation capacity and HLA expression among hPSCs that can be cultured in vitro. Thus, it is expected that homo-SCNT-hESCs will possess a wider range of applications when transplanted with neural precursor cells in the context of clinical trials.

PURPOSE: To compare the effectiveness of device closure and medical therapy in prevention of recurrent embolic event in the Korean population with cryptogenic stroke and patent foramen ovale (PFO). MATERIALS AND METHODS: Consecutive 164 patients (men: 126 patients, mean age: 48.1 years, closure group: 72 patients, medical group: 92 patients) were enrolled. The primary end point was a composite of death, stroke, transient ischemic attack (TIA), or peripheral embolism. RESULTS: Baseline characteristics were similar in the two groups, except age, which was higher in the medical group (45.3±9.8 vs. 50.2±6.1, p<0.0001), and risk of paradoxical embolism score, which was higher in the closure group (6.2±1.6 vs. 5.7±1.3, p=0.026). On echocardiography, large right-to-left shunt (81.9% vs. 63.0%, p=0.009) and shunt at rest/septal hypermobility (61.1% vs. 23.9%, p<0.0001) were more common in the closure group. The device was successfully implanted in 71 (98.6%) patients. The primary end point occurred in 2 patients (2 TIA, 2.8%) in the closure group and in 2 (1 death, 1 stroke, 2.2%) in the medical group. Event-free survival rate did not differ between the two groups. CONCLUSION: Compared to medical therapy, device closure of PFO in patients with cryptogenic stroke did not show difference in reduction of recurrent embolic events in the real world's setting. However, considering high risk of echocardiographic findings in the closure group, further investigation of the role of PFO closure in the Asian population is needed.
Adult ; Aged ; Aged, 80 and over ; Cardiac Catheterization/adverse effects ; Disease-Free Survival ; Embolism/etiology/*prevention & control ; Female ; Fibrinolytic Agents/adverse effects/*therapeutic use ; Foramen Ovale, Patent/complications/*drug therapy/mortality/*surgery ; Humans ; Ischemic Attack, Transient/*drug therapy/mortality/*surgery ; Male ; Middle Aged ; Republic of Korea/epidemiology ; Risk ; Secondary Prevention/methods ; *Septal Occluder Device/adverse effects ; Stroke/etiology/prevention & control ; Treatment Outcome