Background and objectives: Athlete’s heart is characterized by structural cardiac changes, including enlargement and hypertrophy. However, exercise-induced cardiac electrical remodeling is not well known in Asian athletes. We sought to evaluate the association between vigorous exercise and the development of abnormal late potential on signal-averaged electrocardiogram (SAECG).Method: We analyzed 48 Korean professional soccer players and 71 healthy sedentary controls who underwent SAECG and transthoracic echocardiography at Kyung Hee University Hospital. An SAECG was considered abnormal (positive for ventricular late potential) when any one of the three following criteria was met: filtered QRS dura‑ tion > 114 ms, root-mean-square voltage in the terminal 40 ms < 20 uV, or a voltage < 40 uV for more than 38 ms. Results: Fragmented QRS was more commonly found in athletes (1.4% vs. 10.4%). Athletes demonstrated signifi‑ cantly higher proportion of filtered QRS duration > 114 ms (7.0% vs. 22.9%, P = 0.013) and lower terminal QRS rootmean-square voltage < 20 uV (5.6% vs. 20.8%, P = 0.012). Ventricular late potential on SAECG was significantly more frequent in athletes (15.5% vs. 35.4%, P = 0.012). Regarding echocardiographic parameters, the athletes had larger cardiac chamber size; however, these differences became non-significant after adjustment for body surface area, except left ventricular mass index (65.7 ± 12.7 g/m2 vs. 84.7 ± 17.7 g/m2 , P < 0.001). Conclusion Abnormal SAECG findings were significantly more common in athletes than in controls. Further study is needed to determine the clinical impact of these abnormal SAECGs in athletes and cardiac outcomes in the long term.

The therapeutic effects of mesenchymal stem cells (MSCs) in musculoskeletal diseases (MSDs) have been verified in many human and animal studies. Although some tissues contain MSCs, the number of cells harvested from those tissues and rate of proliferation in vitro are not enough for continuous transplantation. In order to produce and maintain stable MSCs, many attempts are made to induce differentiation from pluripotent stem cells (iPSCs) into MSCs. In particular, it is also known that the paracrine action of stem cell-secreted factors could promote the regeneration and differentiation of target cells in damaged tissue. MicroRNAs (miRNAs), one of the secreted factors, are small non-coding RNAs that regulate the translation of a gene. It is known that miRNAs help communication between stem cells and their surrounding niches through exosomes to regulate the proliferation and differentiation of stem cells. While studies have so far been underway targeting therapeutic miRNAs of MSDs, studies on specific miRNAs secreted from MSCs are still minimal. Hence, our ultimate goal is to obtain sufficient amounts of exosomes from iPSC-MSCs and develop them into therapeutic agents, furthermore to select specific miRNAs and provide safe cell-free clinical setting as a cell-free status with purpose of delivering them to target cells. This review article focuses on stem cell therapy on MSDs, specific microRNAs regulating MSDs and updates on novel approaches.

Background and objectives: Athlete’s heart is characterized by structural cardiac changes, including enlargement and hypertrophy. However, exercise-induced cardiac electrical remodeling is not well known in Asian athletes. We sought to evaluate the association between vigorous exercise and the development of abnormal late potential on signal-averaged electrocardiogram (SAECG).Method: We analyzed 48 Korean professional soccer players and 71 healthy sedentary controls who underwent SAECG and transthoracic echocardiography at Kyung Hee University Hospital. An SAECG was considered abnormal (positive for ventricular late potential) when any one of the three following criteria was met: filtered QRS dura‑ tion > 114 ms, root-mean-square voltage in the terminal 40 ms < 20 uV, or a voltage < 40 uV for more than 38 ms. Results: Fragmented QRS was more commonly found in athletes (1.4% vs. 10.4%). Athletes demonstrated signifi‑ cantly higher proportion of filtered QRS duration > 114 ms (7.0% vs. 22.9%, P = 0.013) and lower terminal QRS rootmean-square voltage < 20 uV (5.6% vs. 20.8%, P = 0.012). Ventricular late potential on SAECG was significantly more frequent in athletes (15.5% vs. 35.4%, P = 0.012). Regarding echocardiographic parameters, the athletes had larger cardiac chamber size; however, these differences became non-significant after adjustment for body surface area, except left ventricular mass index (65.7 ± 12.7 g/m2 vs. 84.7 ± 17.7 g/m2 , P < 0.001). Conclusion Abnormal SAECG findings were significantly more common in athletes than in controls. Further study is needed to determine the clinical impact of these abnormal SAECGs in athletes and cardiac outcomes in the long term.

The therapeutic effects of mesenchymal stem cells (MSCs) in musculoskeletal diseases (MSDs) have been verified in many human and animal studies. Although some tissues contain MSCs, the number of cells harvested from those tissues and rate of proliferation in vitro are not enough for continuous transplantation. In order to produce and maintain stable MSCs, many attempts are made to induce differentiation from pluripotent stem cells (iPSCs) into MSCs. In particular, it is also known that the paracrine action of stem cell-secreted factors could promote the regeneration and differentiation of target cells in damaged tissue. MicroRNAs (miRNAs), one of the secreted factors, are small non-coding RNAs that regulate the translation of a gene. It is known that miRNAs help communication between stem cells and their surrounding niches through exosomes to regulate the proliferation and differentiation of stem cells. While studies have so far been underway targeting therapeutic miRNAs of MSDs, studies on specific miRNAs secreted from MSCs are still minimal. Hence, our ultimate goal is to obtain sufficient amounts of exosomes from iPSC-MSCs and develop them into therapeutic agents, furthermore to select specific miRNAs and provide safe cell-free clinical setting as a cell-free status with purpose of delivering them to target cells. This review article focuses on stem cell therapy on MSDs, specific microRNAs regulating MSDs and updates on novel approaches.

Objectives: . To compare the surgical outcomes of externally monitored and conventional buried flaps with the goal of determining the usefulness of external monitoring of buried flaps. Methods: . In this case-control study with propensity score matching, 30 patients were evenly divided into externally monitored buried flap and conventional buried flap groups. The total operative time for free flap reconstruction, the flap survival rate, the length of hospital stay, the initial time of a reliable visual assessment, complications, the final diet achieved, and the duration until diet initiation were compared between the groups. Results: . The mean operative time for reconstruction was 115 minutes (interquartile range, 85–150 minutes) and 142 minutes (interquartile range, 95–180 minutes) in the externally monitored and conventional groups, respectively (P= 0.245). The median length of hospital stay was 24 days (interquartile range, 18–30 days) and 27 days (interquartile range, 20–41 days) in the externally monitored and conventional groups, respectively (P=0.298). The median duration until diet initiation was 15 days (interquartile range, 15–21 days) and 18 days (interquartile range, 15–34 days) in the externally monitored and conventional groups, respectively (P=0.466). The final diet, initial time of a reliable visual assessment, and complications were comparable between the groups, but the external skin paddle provided an excellent visual assessment immediately postoperatively in all cases. Conclusion . The outcomes were comparable between the groups, indicating that externalization of the cutaneous component of a buried flap may be a straightforward and useful technique for monitoring a buried anterolateral thigh free flap in laryngopharyngeal reconstructions. The salvage and false-positive rates of compromised flaps should be compared in large subject groups in future studies to prove that the use of an external skin paddle improves flap monitoring.

Objective: To investigate the predictive value of intraplaque neovascularization (IPN) for cardiovascular outcomes. Materials and Methods: We evaluated 217 patients with coronary artery disease (CAD) (158 men; mean age, 68 ± 10 years) with a maximal carotid plaque thickness ≥ 1.5 mm for the presence of IPN using contrast-enhanced ultrasonography. We compared patients with (n = 116) and without (n = 101) IPN during the follow-up period and investigated the predictors of major adverse cardiovascular events (MACE), including cardiac death, myocardial infarction, coronary artery revascularization, and transient ischemic accident/stroke. Results: During the mean follow-up period of 995 ± 610 days, the MACE rate was 6% (13/217). Patients with IPN had a higher maximal thickness than those without IPN (2.86 ± 1.01 vs. 2.61 ± 0.84 mm, p = 0.046). Common carotid artery-peak systolic velocity, left ventricular mass index (LVMI), and ventricular-vascular coupling index were significantly correlated with MACE. However, on multivariate Cox regression analysis, increased LVMI was independently related to MACE (p < 0.05). The presence of IPN could not predict MACE. Conclusion The presence of IPN was related to a higher plaque thickness but could not predict cardiovascular outcomes better than conventional clinical factors in patients with CAD.

Background: Pedicle screw augmentation with bone cement has been experimentally demonstrated to increase the pullout strength. However, the mechanisms of screw loosening are complicated and interacting. Although vertebroplasty augmentation and fenestrated screw augmentation have been compared in many studies, there has been no comparative study on their clinical effects and complications in real clinical settings. We investigated clinical effects of bone cement augmentation of a pedicle screw and differences according to augmentation methods. Methods: Of the total 241 patients who had osteoporosis and underwent posterior pedicle screw fixation without anterior bone graft between January 2010 and December 2016, 132 patients with ≥2 years of radiological follow-up were included in this retrospective study. The patients were divided into group I (unaugmented) and group II (bone cement augmented). Group II was subdivided into II-S group (solid screw augmented) and II-F group (fenestrated screw augmented). The incidence of screw loosening was compared between groups I and II. Cement leakage, screw loosening, and screw fractures were investigated in the subgroups. Results: In total, 36 of 71 (52%, group I) unaugmented cases and 96 of 170 (56%, group II) augmented cases were followed up for ≥2 years. Of the total 78 solid screw augmented cases, 42 (56%) were in II-S group; 54 of the total 92 (59%) fenestrated screw augmented cases were in II-F group. Groups I and II were homogenous regarding demographic characteristics; II-S and II-F groups were also homogenous. The incidence of screw loosening was 50.0% (18/36) in group I and 7.3% (7/96) in group II (p < 0.001). Cement leakage developed in 2 of 42 (4.8%) cases in II-S group and in 5 of 54 (9.3%) cases in II-F group (p = 0.462). Screw loosening developed in 6 of 42 (14.3%) cases in II-S group and in 1 of 54 cases (1.9%) in II-F group (p = 0.041). Screw fracture developed in none of 42 cases in II-S group and in 3 of 54 cases (5.6%) in II-F group (p = 0.254). Conclusions In osteoporotic patients, bone cement augmentation of a pedicle screw decreased the incidence of screw loosening, and fenestrated screw augmentation was more effective than vertebroplasty augmentation.

BACKGROUND: Spinal diseases are self-limited or non-progressive in many cases. Epidural steroid injection (ESI) is a common nonsurgical treatment option for spinal pain. Despite concerns about complications of repeated steroid injection, few studies reported on the adrenal function of spine disease patients undergoing surgery after ESI. We investigated the influence of preoperative multiple ESIs on adrenal function in spine surgery patients. METHODS: This was a retrospective study with prospective data collection. Those who underwent elective spinal operations and had a history of multiple ESIs from January to June 2017 were selected as a study group. Those who underwent knee arthroplasty and did not have a history of ESI and any kind of steroid injection in other areas during 6 months before surgery were selected as a control group. Demographic data were compared to assess homogeneity between groups. We assessed the preoperative serum cortisol level (SCL) to compare the basal adrenal function between groups. Also, we assessed the elevation of SCL postoperatively to evaluate the adrenal response to the surgical stress in each group. For subgroup analysis, we divided all patients into normal (7–28 µg/dL) and subnormal groups according to SCL and analyzed risk factors of adrenal suppression with multivariate logistic regression test. RESULTS: There were 53 patients in the study group and 130 in the control group. Age and sex were homogeneous between groups. There was significant intergroup difference in preoperative SCL (10.4 ± 4.8 µg/dL in the study group vs. 12.0 ± 4.2 µg/dL in the control group; p = 0.026).The postoperative day one SCL was 11.6 ± 5.0 µg/dL in the study group without significant increase from the preoperative level (p = 0.117), whereas the increase was significant in the control group with a postoperative level of 14.4 ± 4.4 µg/dL (p < 0.001). Among all patients, the SCL was subnormal in 18 patients and within the normal range in 165. Spine surgery was the independent risk factor irrespective of age and sex (odds ratio, 3.472; p = 0.015). CONCLUSIONS: Our results suggest that concern should be raised about the influence of preoperative multiple ESIs on adrenal suppression in spine surgery patients.
Arthroplasty, Replacement, Knee ; Data Collection ; Humans ; Hydrocortisone ; Logistic Models ; Prospective Studies ; Reference Values ; Retrospective Studies ; Risk Factors ; Spinal Diseases ; Spine

BACKGROUND: Combination of metformin to reduce the fasting plasma glucose level and an α-glucosidase inhibitor to decrease the postprandial glucose level is expected to generate a complementary effect. We compared the efficacy and safety of a fixed-dose combination of voglibose plus metformin (vogmet) with metformin monotherapy in drug-naïve newly-diagnosed type 2 diabetes mellitus. METHODS: A total of 187 eligible patients aged 20 to 70 years, with a glycosylated hemoglobin (HbA1c) level of 7.0% to 11.0%, were randomized into either vogmet or metformin treatments for 24 weeks. A change in the HbA1c level from baseline was measured at week 24. RESULTS: The reduction in the levels of HbA1c was −1.62%±0.07% in the vogmet group and −1.31%±0.07% in the metformin group (P=0.003), and significantly more vogmet-treated patients achieved the target HbA1c levels of <6.5% (P=0.002) or <7% (P=0.039). Glycemic variability was also significantly improved with vogmet treatment, estimated by M-values (P=0.004). Gastrointestinal adverse events and hypoglycemia (%) were numerically lower in the vogmet-treated group. Moreover, a significant weight loss was observed with vogmet treatment compared with metformin (−1.63 kg vs. −0.86 kg, P=0.039). CONCLUSION: Vogmet is a safe antihyperglycemic agent that controls blood glucose level effectively, yields weight loss, and is superior to metformin in terms of various key glycemic parameters without increasing the risk of hypoglycemia.
Blood Glucose ; Diabetes Mellitus, Type 2 ; Fasting ; Glucose ; Hemoglobin A, Glycosylated ; Humans ; Hypoglycemia ; Metformin ; Weight Loss