Radiation shielding effects of lead equivalent thickness of a radiation protective apron and distance during C-arm fluoroscopy-guided pain interventions: A randomized trial.

BACKGROUND: The present study aimed to evaluate the degree of radiation shielding effects according to lead equivalent thickness and distance during C-arm fluoroscopy-guided lumbar interventions. METHODS: The exposure time and air kerma were recorded using a fluoroscope. The effective dose (ED) was measured with and without the shielding material of the lead apron using 2 dosimeters at 2 positions. According to the lead equivalent thickness of the shielding material and distance from the side of the table, the groups were divided into 4 groups: group 1 (lead equivalent thickness 0.6 mm, distance 0 cm), group 2 (lead equivalent thickness 0.6 mm, distance 5 cm), group 3 (lead equivalent thickness 0.3 mm, distance 0 cm), and group 4 (lead equivalent thickness 0.3 mm, distance 5 cm). Mean differences such as air kerma, exposure time, ED, and ratio of EDs (ED with protector/ED without protector) were analyzed. RESULTS: A total of 400 cases (100 cases in each group) were collected. The ratio of ED was significantly lower in groups 1 and 2 (9.18 ±â€…2.78% and 9.56 ±â€…3.29%, respectively) when compared to that of groups 3 and 4 (21.93 ±â€…4.19% and 21.53 ±â€…4.30%, respectively). The reductive effect of a 5-cm distance was 33.3% to 36.1% when comparing the ED between groups 1 and 2 and groups 3 and 4. CONCLUSIONS: The 0.3- and 0.6-mm lead equivalent thickness protectors have a radiation attenuation effect of 78.1% to 78.5% and 90.4% to 90.8%, respectively. The 5-cm distance from the side of the table reduces radiation exposure by 33.3% to 36.1%.

General anesthesia, using remimazolam, for the patient with myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD): A case report.

RATIONALE: Myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD) is one of auto-immune demyelinating diseases of nervous system. Although both regional anesthesia and general anesthesia has been successfully performed in the patient with demyelinating diseases of nervous system, it has been controversial which one is better. PATIENT CONCERNS: Forty-four male patient was admitted for arthroscopic elbow surgery due to limitation of range of motion. The patient was diagnosed as MOGAD with anti-N-methyl-D-aspartate (NMDA) receptor encephalitis, and steroid was used to prevent and treat symptoms and signs. DIAGNOSIS: He was diagnosed as MOGAD with anti-NMDA receptor encephalitis, 1 year ago. The patient complaint of dizziness, diplopia, nausea, vomiting, seizure, general weakness and so on when he was confirmed as MOGAD with anti-NMDA receptor encephalitis. The diagnosis of MOGAD was confirmed with positive anti-myelin oligodendrocyte glycoprotein (MOG) Immunoglobulin (Ig)G and negative anti-aquaporin 4 (AQP4) IgG in the blood. INTERVENTIONS AND OUTCOMES: After steroid cover, total intravenous anesthesia (TIVA) with remimazolam and remifentanil was established for the patients. Rocuronium was administered under monitoring of neuromuscular blockade, using train of 4 (TOF). The operation was performed without any event under right lateral decubitus position. The patient was uneventfully recovered from anesthesia. LESSONS: The case report showed total intravenous anesthesia with remimazolam and remifentanil under proper monitoring was successfully performed in the patient with MOGAD.

Physicochemically modified high-resolution tin oxide thin film using soft imprinting.

We carried out nanoimprinting lithography on solution-processed tin oxide (SnO) film for use as a liquid crystal (LC) alignment layer, for which we used a parallel configuration. To transfer the nanostructures onto the SnO film, we conducted an experiment according to curing, from which fine nanostructures on the SnO film were obtained at a curing temperature of 200 °C. These acted as a guide for the arrangement of the LC molecules and induced geometric restriction which minimized elastic distortion energies, and so the LC molecules could be aligned in the direction of the nanostructures. The LC alignment state was investigated using polarized optical microscopy, and the pre-tilt angle was measured using a crystal rotation method. With high thermal endurance and drastically low power consumption, the nano patterned SnO was shown to be a promising candidate for LC applications. The nanopatterning process combined with nanoimprinting lithography and solution-processed inorganic materials exhibited the possibility of broadening the features of nanostructure-mounted applications, including LC devices.

Solution-Driven Imprinting Lithography of Sol-Gel ZnO Thin Films for Liquid Crystal Display.

We present a simple and economically convenient method to fabricate nanopatterned ZnO films by imprinting lithography and use them for the layer alignment of liquid crystal (LC) displays. First, a one-dimensional nanopattern was obtained by laser interference lithography on a silicon wafer, and the silicon mold replica was transferred onto a flexible polydimethylsiloxane (PDMS) sheet for conformal patterning. The so-obtained PDMS mold was then applied on a ZnO film spin-coated on a glass substrate. During the imprinting process, the temperature was controlled from 100 to 250 °C to observe the transferring morphologies of the ZnO film; the nanopattern was successfully transferred at annealing temperatures of 200 and 250 °C because the ZnO film at the sol state filled the cavities of the PDMS nanopattern and solidified, forming a negative replica of the nanopattern. The direction of the nanopatterned ZnO film served as a guide for aligning the LC molecules on the LC surface at the centimeter scale and, due to their elastic characteristics and group behavior, propagating their directional states in the LC bulk. The resulting LC cell exhibited an enhanced electro-optical performance and high thermal endurance above 180 °C. The geometry of the alignment layer increased the electric field on the ZnO film and showed reduced threshold voltage. In addition, since flexible devices are generally based on polyimide, which imidized at around 200 °C, the relatively low annealing temperatures of our fabricated nanopatterned ZnO film allow it to be mounted on such devices without any deterioration of the underlying thermoplastic substrate. Therefore, nanopatterned ZnO has a considerable potential for advanced LC displays.

The Neutrophil-to-Lymphocyte Ratio and Preoperative Pulmonary Function Test Results as Predictors of In-Hospital Postoperative Complications after Hip Fracture Surgery in Older Adults.

Purpose: This study retrospectively evaluated the usefulness of the neutrophil-to-lymphocyte ratio (NLR), prognostic nutritional index (PNI), and pulmonary function test (PFT) results as objective predictors of in-hospital postoperative complications after hip fracture surgery in older adults. Methods: The patients aged >65 years who underwent hip fracture surgery under general anaesthesia were enrolled. In-hospital postoperative complications with preoperative NLR, PNI and PFT results were evaluated. The NLR was calculated as the preoperative neutrophil count/lymphocyte count in peripheral blood. The PNI was calculated as the serum albumin (g/dL) × 10 + total lymphocyte count × 0.005 (/mm3). Results: One hundred ninety nine patients were analysed. The most common postoperative complications were respiratory complications. Compared with patients who did not have postoperative complications, patients with postoperative complications had a significantly higher NLR (8.01 ± 4.70 vs. 5.12 ± 4.34, p < 0.001), whereas they had a significantly lower PNI (38.33 ± 6.80 vs. 42.67 ± 6.47, p < 0.001), preoperative functional vital capacity (FVC; 2.04 ± 0.76 vs. 2.45 ± 0.71 L, p < 0.001), and forced expiratory volume at 1 s (FEV1; 1.43 ± 0.53 vs. 1.78 ± 0.58 L, p < 0.001). Multiple logistic regression analysis identified NLR (odds ratio [OR], 1.142; 95% confidence interval [CI], 1.060−1.230; p < 0.001) and FEV1 (OR, 0.340; 95% CI, 0.191−0.603; p < 0.001) as risk factors for postoperative complications after hip fracture surgery. Conclusion: Preoperative NLR and FEV1 are objective predictors of in-hospital postoperative complications after hip fracture surgery in older patients.

Superior nanopatterns via adjustable nanoimprint lithography on aluminum oxide in high-K thin films with ultraviolet curable polymer.

The present study substantiate that ultraviolet-nanoimprint lithography (UV-NIL) can be used to transfer a one-dimensional nano-pattern onto a high-k thin film of aluminum oxide mixed with a UV photocuring agent. Polydimethylsiloxane (PDMS) molds fabricated on silicon wafers were made using deep ultraviolet laser interference lithography in order to investigate one-dimension nanopatterns. These imprinted nano-patterns induce geometric deformations in the liquid crystal (LC), creating collective and elastic properties, which act as a guide for homogeneous alignment. The nanoimprint method can process a large area, so it can be processed much easier, faster, and more accurately than the conventional rubbing method. Moreover, the optical properties of the nano-imprinted aluminum oxide (AlO) thin-film are about 1.5p% superior to that of conventional commercialized cells, so it has a high effect on the luminance and color gamut of the display. After pattern imprinting, atomic force microscope (AFM) was performed to confirm the result. We can compared the cycle of AlO mixed with UV photocuring agent PDMS pattern cycle, the period is 776 and 750 nm, the width is 468 and 450 nm, the spacing is 292 and 300 nm, and the height is 40 and 30 nm. The nano-imprinted film appears to replicate the width, amplitude, and spacing of the PDMS template. In addition, X-ray photoelectron spectroscopy was performed to determine the chemical properties of the thin film and it was confirmed that UV irradiation induces oxidation, thus increases the intensity significantly. The binding energies of Al 2p and C-O spectra were situated at 74.27 ± 0.5 eV and 531.78 ± 0.5 eV, respectively.

Formation of Wrinkle Structures on Styrene-b-isoprene-b-styrene Films Using One-Step Ion-Beam Irradiation.

We investigated the wrinkle formation on ion-beam (IB)-irradiated substrates coated with the thermoplastic elastomer styrene-b-isoprene-b-styrene (SIS) and demonstrate a relation of the wrinkle structure and the newly formed top layer induced by IB. IB irradiation led to polymer cross-linking on the surface, thereby forming a new skin layer, a finding which was supported by an X-ray photoelectron spectroscopy analysis, Young moduli calculated using force-distance curves, and time-of-flight secondary ion mass spectrometry depth profiling. The wrinkle wavelength increased according to the irradiation time, which indicates that the latter mainly increased the thickness of the cross-linking layer. The increase in the wrinkle wavelength varied from 420 to 670 nm by changing the IB irradiation time. In this paper, we present not only the expectation of wrinkle fabrication using our method but also the possibility of choosing diverse materials such as the thermoplastic elastomer SIS for fabrication of wrinkle structures.

One-dimensional surface wrinkling for twisted nematic liquid crystal display based on ultraviolet nanoimprint lithography.

Surface wrinkling method is used to fabricate a 1-dimensional nanostructure. The structure is transferred to an ultraviolet cured polymer which is used as an alignment layer. The anisotropic geometry serves as a guide for aligning liquid crystal molecules uniformly without defects. The TN-LC cell showed a successful LC switching, with a response time of 20.5 ms, and a threshold voltage of 2.00 V. It also exhibited high thermal stability above 180°C. The proposed UV-cured polymers with 1-D nano wrinkle geometry can be a candidate for alternative alignment techniques, for advanced liquid crystal devices with high thermal budgets.

Physicochemical Modification Effect on Homogeneously Aligned Liquid Crystals Based on the Nickel Oxide Thin Film.

We demonstrated homogeneous liquid crystal (LC) alignment on Nickel Oxide (NiO) films subjected to ion beam (IB) irradiation. Uniform LC alignment was achieved at high IB intensity values of 1200 and 1800 eV. To determine the mechanism of LC alignment following IB irradiation, physicochemical analysis was performed using atomic force microscopy and X-ray photoelectron spectroscopy. IB irradiation with high intensity increases uniformity of the surface, and IB irradiation induces the formation of oxygen vacancies and increases the NiO (Ni2+) phase components. Hence, both of the smooth surface and the strong van der Waals interactions between the NiO film and the LC molecules provides the LC molecules with a stable anchor on the surface, leading to uniform LC alignment on NiO films after IB irradiation. IB-irradiated NiO exhibited a high transparency of 85% in the visible light range as compared with the 83% average transmittance of conventional polyimide, which makes the IB-irradiated NiO alignment layer attractive in display devices.

A score for decision making during percutaneous coronary intervention in acute myocardial infarction patients with multivessel disease.

BACKGROUND/AIMS: The optimal percutaneous coronary intervention (PCI) strategy in patients with acute myocardial infarction (AMI) with multivessel disease (MVD) is uncertain. This study was designed to develop a novel and simple tool for assessing an individualized and optimized PCI strategy in AMI patients with MVD. METHODS: In total, 5,025 patients with AMI from nine centers at two universities were enrolled in the prospective Convergent Registry of Catholic and Chonnam University for Acute Myocardial Infarction (COREA-AMI) registry from January 2004 through December 2009. From among them, we selected 2,630 patients with MVD who were treated by culprit-only or multivessel (MV) PCI. We investigated major adverse cardiac events (MACEs) during a 1-year clinical follow-up. Using a subgroup analysis, we extracted variables for use in the culprit only versus multivessel revascularization (CONVERSE) score, which showed a preference for MV PCI rather than culprit-only PCI for treating MVD. RESULTS: The CONVERSE score was constructed using eight independent variables (1 point for each variable): age > 65 years, hypertension, diabetes mellitus, high Killip class (III or IV), low left ventricular ejection fraction (≤ 50%), low creatinine clearance (≤ 60 mL/min), high level of high-sensitivity C-reactive protein (≥ 2.0 mg/L), and left anterior descending artery or left main as the nonculprit vessel. The incidence of MACEs increased linearly with the CONVERSE score. The receiver operating characteristic curve showed that the cutoff value was 3 points. CONCLUSION: The results suggest that patients with a CONVERSE score of 3 or more should undergo MV PCI.

Erratum: Two-year clinical outcomes in stable angina and acute coronary syndrome after percutaneous coronary intervention of left main coronary artery disease.

[This corrects the article on p. 1084 in vol. 31, PMID: 27756119.].

Optimal Timing of Percutaneous Coronary Intervention for Nonculprit Vessel in Patients with ST-Segment Elevation Myocardial Infarction and Multivessel Disease.

BACKGROUND AND OBJECTIVES: In patients with ST-segment elevation myocardial infarction (STEMI) and multivessel disease (MVD), the optimal timing of staged percutaneous coronary intervention (PCI) remains unclear. SUBJECTS AND METHODS: This study was a retrospective analysis of 753 STEMI patients with MVD who were treated by multivessel PCI in the Convergent Registry of Catholic and Chonnam University for Acute myocardial infarction (MI). Patients were divided into 3 groups according to the time from initial to staged PCI: group 1 (n=316, multivessel PCI performed during the index procedure), group 2 (n=360, staged PCI within 1 week), and group 3 (n=77, staged PCI after 1 week). The endpoint was major adverse cardiac events (MACEs), including all-cause mortality, non-fatal MI, and repeat PCI during 3.4 years follow-up. RESULTS: The incidence of composite MACEs was higher in group 3 than in group 1 (odds ratio [OR]: 1.83, 95% confidence interval [CI]: 1.06 to 3.18, p=0.031). However, the risk of MACEs in groups 1 and 2 was comparable (OR: 1.01, 95% CI: 0.70 to 1.46, p=0.950). In multivariate logistic regression, independent predictors of 3-year MACEs were high Killip class (OR: 2.72, 95% CI: 1.38 to 5.37, p=0.004), left ventricular ejection fraction <45% (OR: 1.57, 95% CI: 1.06 to 2.32, p=0.024), and group 3 (OR: 1.83, 95% CI: 1.06 to 3.18, p=0.009). CONCLUSION: Deferred staged PCI after one week index PCI was associated with the highest MACE, as compared to both simultaneous multivessel PCI and early staged PCI <1 week.

Formyl Peptide Receptor 2 Is Involved in Cardiac Repair After Myocardial Infarction Through Mobilization of Circulating Angiogenic Cells.

Increasing evidence suggests that circulating angiogenic cells (CACs) promote repair of ischemic tissues. Activation of formyl peptide receptor 2 (Fpr2) has been reported to stimulate repair of ischemic heart. This study was conducted to investigate the role of Fpr2 on CAC mobilization and cardiac protection in myocardial infarction (MI). WKYMVm, a strong agonist for Fpr2, was administered in a murine model of acute MI, and mobilization of CACs including endothelial progenitor cells (CD34+ Flk1+ or Sca1+ Flk1+ cells) in peripheral blood was monitored. CAC mobilization by daily injection of WKYMVm for the first 4 days after MI was as efficient as granulocyte colony-stimulating factor and provided myocardial protection from apoptosis with increased vascular density and preservation of cardiac function. Transplantation of bone marrow (BM) from green fluorescent protein mice showed that BM-derived cells homed to ischemic heart after WKYMVm treatment and contributed to tissue protection. Transplantation of BM from Fpr2 knockout mice showed that Fpr2 in BM cells is critical in mediation of WKYMVm-stimulated myocardial protection and neovascularization after MI. These results suggest that activation of Fpr2 in BM after WKYMVm treatment provides cardiac protection through mobilization of CACs after MI, which may lead to the development of a new clinical protocol for treating patients with ischemic heart conditions. Stem Cells 2017;35:654-665.

Two-year clinical outcomes in stable angina and acute coronary syndrome after percutaneous coronary intervention of left main coronary artery disease.

BACKGROUND/AIMS: This study appraised the long term clinical outcomes of patients treated with percutaneous coronary intervention (PCI) for unprotected left main coronary artery (ULMCA) disease. There are limited data regarding long-term clinical outcomes after PCI for ULMCA disease. METHODS: From 2001 to 2011, a total of 448 patients who underwent PCI for ULMCA disease and had 2-year clinical follow-up, were analyzed. The study patients were divided into two groups: group I (stable angina pectoris [SAP], n = 60, 48 men, 62 ± 10 years) and group II (acute coronary syndrome [ACS], n = 388, 291 men, 64 ± 10 years). We evaluated clinical and angiographic characteristics and major adverse cardiac events (MACE) during 2-year clinical follow-up. RESULTS: Mean age of studied patients was 64 ± 10 years with 339 male patients. Average stent diameter was 3.6 ± 0.4 mm and stent length was 19.7 ± 6.3 mm. Stent implantation techniques and use of intravascular ultrasound guidance were not different between two groups. In-hospital mortality was 0% in group I and 7% in group II (p = 0.035). One-month mortality was 0% in group I and 7.7% in group II (p = 0.968). Two-year survival rate was 93% in the group I and 88.4% in the group II (p = 0.921). Predictive factors for 2-year MACE were hypertension, Killip class ≥ 3, and use of intra-aortic balloon pump by multivariate analysis. CONCLUSIONS: Although in-hospital mortality rate was higher in ACS than in SAP, clinical outcomes during 2-year clinical follow-up were similar between SAP and ACS after PCI of ULMCA.

Long-Term Clinical Outcomes of Transient and Persistent No Reflow Phenomena following Percutaneous Coronary Intervention in Patients with Acute Myocardial Infarction.

BACKGROUND AND OBJECTIVES: There is limited information on the transient or persistent no reflow phenomenon in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: The study analyzed 4329 patients with AMI from a Korean multicenter registry who underwent PCI using coronary stents (2668 ST-elevation and 1661 non-ST-elevation myocardial infarction [MI] patients): 4071 patients without any no reflow, 213 with transient no reflow (no reflow with final thrombolysis in myocardial infarction [TIMI] flow grade 3), and 45 with persistent no reflow (no reflow with final TIMI flow grade≤2). The primary endpoint was all-cause mortality during 3-year follow-up. We also analyzed the incidence of cardiac mortality, non-fatal MI, re-hospitalization due to heart failure, target vessel revascularization, and stent thrombosis. RESULTS: The persistent no reflow group was associated with higher all-cause mortality (hazard ratio [HR] 1.98, 95% confidence interval [CI] 1.08-3.65, p=0.028) and cardiac mortality (HR 3.28, 95% CI 1.54-6.95, p=0.002) compared with the normal reflow group. Transient no reflow increased all-cause mortality only when compared with normal reflow group (HR 1.58, 95% CI 1.11-2.24, p=0.010). When comparing transient and persistent no reflow, persistent no reflow was associated with increased all-cause mortality (46.7 vs. 24.4%, log rank p=0.033). CONCLUSION: The persistent no reflow phenomenon was associated with a poor in-hospital outcome and increased long-term mortality mainly driven by increased cardiac mortality compared to the transient no reflow phenomenon or normal reflow.

Tailoring the Orientation and Periodicity of Wrinkles Using Ion-Beam Bombardment.

The present study demonstrates that surface reformation in polydimethylsiloxane can be controlled using ion-beam (IB) irradiation. This can be done by simply varying the IB incidence angle and requires no change in the energy source. By controlling the incidence angle of IB irradiation, we were able to continuously control the pattern of the wrinkle structure, that is, a randomly formed pattern or an anisotropic one. Moreover, the directional characteristics of the wrinkle pattern control the alignment of liquid crystal molecules. This control is a function of the incidence angle of the IB. These simple methods can provide considerable flexibility in the fabrication of wrinkle structures.

Correlation of Angina Pectoris and Perfusion Decrease by Collateral Circulation in Single-Vessel Coronary Chronic Total Occlusion Using Myocardial Perfusion Single-Photon Emission Computed Tomography.

PURPOSE: To evaluate the perfusion decrease in donor myocardium by collateral circulation and its correlation with angina pectoris in patients with chronic total occlusion (CTO) using myocardial perfusion single-photon emission computed tomography (MPS). MATERIALS AND METHODS: Thirty-six patients with single-vessel CTO without any other stenosis were included. All patients underwent MPS and coronary angiography (CAG) within 2 months. Total 72 donor arteries were evaluated for the grades of collaterals to the CTO artery using the Rentrop grading system on CAG. Perfusion defects and perfusion scores in donor and CTO territories were analyzed on MPS. Myocardial perfusion of donor and CTO territories were evaluated according to the presence of angina pectoris and the grades of collateral circulation. RESULTS: When the CTO territory was ischemic, symptomatic patients showed higher summed difference scores in the CTO territory compared to asymptomatic patients (3.5 ± 2.4 vs. 1.5 ± 0.8 for symptomatic and asymptomatic groups respectively; p = 0.034). However, when the CTO territory was nonischemic, symptomatic patients showed higher summed stress scores (SSS, 4.3 ± 2.9 vs. 1.6 ± 1.2; p = 0.032) and summed rest scores (SRS, 4.2 ± 2.5 vs. 1.5 ± 1.1; p = 0.003) in the donor territories. On the per-vessel analysis, perfusion defects in donor territories were more frequent (0 % vs. 53 % vs. 86 % for Rentrop 0, Rentrop 1-2 and Rentrop 3, respectively; p < 0.001) and showed higher SSS (0.0 ± 0.0, 1.3 ± 1.6 and 2.1 ± 1.1 for Rentrop 0, Rentrop 1-2 and Rentrop 3, respectively; p = 0.001) and SRS (0.0 ± 0.0, 1.0 ± 1.4 and 1.7 ± 1.2; p = 0.003) at higher Rentrop grades, but their patterns were variable. CONCLUSION: Angina pectoris was related to either ischemia of the myocardium beyond CTO or a perfusion decrease in the donor myocardium. The perfusion decrease in donor myocardium positively correlated with the collateral grades.

5-Azacytidine modulates interferon regulatory factor 1 in macrophages to exert a cardioprotective effect.

Macrophages are actively involved in inflammatory responses during the progression of cardiac injury, including myocardial infarction (MI). A previous study showed that 5-azacytidine (5AZ), a DNA methylation inhibitor, can ameliorate cardiac injury by shifting macrophages toward an anti-inflammatory phenotype via iNOS inhibition. Here, we show that the beneficial effect of 5AZ is associated with sumoylation of interferon regulatory factor-1 (IRF1) in macrophages. IRF1 is a critical transcription factor for iNOS induction and is antagonized by IRF2. In the stimulated macrophages, IRF1 accumulated in the nucleus without degradation by 5AZ treatment. In animal study, 5AZ administration resulted in significant improvements in cardiac function and fibrosis. IRF1-expressing macrophages were more abundant in the 5AZ-treated MI group than in the PBS-treated MI group. Because sumoylated IRF1 is known to mimic IRF2, we examined the IRF1 sumoylation. Sumoylated IRF1 was resistant to degradation and significantly increased in the 5AZ-treated MI group. Collectively, 5AZ had a protective effect after MI by potentiation of IRF1 sumoylation and is suggested as a novel therapeutic intervention for cardiac repair.

Localized Ion-Beam Irradiation-Induced Wrinkle Patterns.

We observe a localized irradiation-induced wrinkle pattern on poly(dimethylsiloxane) (PDMS) via a long pattern mask. Localized ion-beam irradiation induces an inhomogeneous wrinkle pattern on the treated region. To confirm the inhomogeneity of the entire wrinkle pattern, its morphology was investigated using optical microscopy, which revealed separated regions in the wrinkle pattern. We used atomic force microscopy for quantitative analysis of the wrinkle pattern morphology and analyzed the angular distribution and the direction of compressive stress of the irradiated area. We confirmed the direction of stress release along the distance from the edges, and we achieved control of the orientation of the wrinkle pattern by altering the width of the irradiated area. Investigation of the inhomogeneities in a localized wrinkle formation provides an understanding of the formation mechanism to enhance its performance and application in various fields.

Involvement of miR-34c in high glucose-insulted mesenchymal stem cells leads to inefficient therapeutic effect on myocardial infarction.

High glucose-insulted bone marrow-derived mesenchymal stem cells (BMCs) showed impaired angiogenesis along with downregulation of stem cell factor (SCF). This study was designed to determine the involvement of microRNAs (miR), which are actively involved in the physiological function of stem cells. We observed that miR-34c was significantly induced by high glucose treatment and blunted tube formation of BMCs. Stem cell factor (SCF) was confirmed as a target of miR-34c by 3'-UTR promoter analysis and Western blot. SCF knockdown by siRNA induced Krüppel-like factor 4 (KLF4) and resulted in the blockade of angiogenesis of BMCs. Sequentially, KLF4 overexpression completely blocked tube formation through inducing PAI-1 (plasminogen activator inhibitor-1). To study the action of miR-34c in terms of the therapeutic potential of BMCs, myocardial infarction (MI) was induced by ligation of the coronary artery in nude mice, BMCs transfected with miR-control or miR-34c were injected into the infarcted myocardium 7 days later, and histological studies were performed 2 weeks later. Cardiac fibrosis was 18.24±4.7% in the miR-34c-BMC group and 10.01±0.2% in the miR-control-BMC group (p<0.05). Cardiac function and vessel density were decreased in the miR-34c-BMC group compared with the miR-con-BMC group. Particularly, miR-34c-BMCs failed to incorporate into vessels. Our results show that the angiogenic activity of BMCs is finely regulated by the miR-34c-SCF-KLF4 axis, which is a potent translational target for optimizing the therapeutic activity of autologous BMCs for cardiac repair.