Nicotinic acetylcholine receptor α7 and β4 subunits contribute nicotine-induced apoptosis in periodontal ligament stem cells.

Nicotine, a major component of cigarette smoking, is the important risk factor for the development of periodontal disease. However, the mechanisms that underlie the cytotoxicity of nicotine in human periodontal ligament stem cells (PDLSCs) are largely unknown. Thus, the purpose of this study was to determine the cytotoxic effect of nicotine by means of nicotinic acetylcholine receptor (nAChR) activation in PDLSCs.

Comparison of the long-term immunogenicity of two pandemic influenza A/H1N1 2009 vaccines, the MF59-adjuvanted and unadjuvanted vaccines, in adults.

Since the first reports of the A/H1N1 virus in April 2009, the pandemic influenza virus spread globally and circulated for a long time. The primary method for the control of influenza is vaccination, but levels of influenza vaccine-induced antibody are known to decline rapidly during a 6-month period. In adults aged 18 to 64 years, we compared the long-term immunogenicity of two of the influenza A/H1N1 2009 monovalent vaccines, 3.

Depigmenting activity of new kojic acid derivative obtained as a side product in the synthesis of cinnamate of kojic acid.

We synthesized cinnamate derivatives of kojic acid for use as depigmenting agents by various esterification methods. The cinnamate of 5-position of kojic acid (6) was obtained by EDC coupling, DCC coupling, acid chloride, and mixed anhydride methods. To obtain the cinnamate of the 2-position of kojic acid (7), we carried out the nucleophilic addition of the potassium salt of cinnamic acid to kojyl chloride.

Sodium fluoride induces apoptosis in mouse embryonic stem cells through ROS-dependent and caspase- and JNK-mediated pathways.

Sodium fluoride (NaF) is used as a source of fluoride ions in diverse applications. Fluoride salt is an effective prophylactic for dental caries and is an essential element required for bone health. However, fluoride is known to cause cytotoxicity in a concentration-dependent manner.

Circumferential evaluation of the neointima by optical coherence tomography after ABSORB bioresorbable vascular scaffold implantation: can the scaffold cap the plaque?

Objective: To quantify the circumferential healing process at 6 and 12 months following scaffold implantation.

Background: The healing process following stent implantation consists of tissue growing on the top of and in the space between each strut. With the ABSORB bioresorbable vascular scaffold (BVS), the outer circumference of the scaffold is detectable by optical coherence tomography (OCT), allowing a more accurate and complete evaluation of the intra-scaffold neointima.

Risk of target lesion failure in relationship to vessel angiographic geometry and stent conformability using the second generation of drug-eluting stents.

Background: Vessel angulation and large changes in vessel geometry after stent implantation have been associated with an increased risk of target lesion failure (TLF) using bare-metal stents. Second-generation drug-eluting stents (DES)offer superior conformability and inhibition of neointima. The aim of the study is to investigate the relationship between pre and post-implant vessel geometry and the occurrence of TLF at 1 year after treatment with second-generation DES; and to compare the conformability of Resolute and Xience stents.

Poly(L-lactic acid) nanocylinders as nanofibrous structures for macroporous gelatin scaffolds.

Electrospun Nanofiber sheets have been shown to mimic the structure of extracellular matrix (ECM). Although these nanofibers have shown great potential for use as tissue engineering scaffolds, it is difficult for the electrospun nanofiber based sheets to be shaped into the desired three-dimensional structure. In this study, poly(L-lactic acid) (PLLA), a biodegradable and biocompatible polyester, was electrospun to produce nanofibers that were treated with an amino group containing base in order to fabricate polymeric nanocylinders.

Development of a biodegradable sirolimus-eluting stent coated by ultrasonic atomizing spray.

In this study, poly(D,L lactic-co-glycolic acid) (PLGA) was used as a drug carrier to generate two types of stents loaded with different concentrations of sirolimus. These stents were prepared by ultrasonic atomizing spray coating. Ultrasonic atomizing spray nozzle uses a low-pressure air/gas to produce a soft, highly focused beam of small spray drops.

Reproducibility of intravascular ultrasound iMAP for radiofrequency data analysis: implications for design of longitudinal studies.

Background: iMAP is a new intravascular ultrasound (IVUS) derived technique for tissue characterization using spectral analysis. Since there is a need for reproducibility data to design longitudinal studies, we sought to assess the in vivo reproducibility of this imaging technique.

Methods: iMAP (40 MHz, Boston Scientific Corporation) was performed in patients referred for elective percutaneous intervention and in whom a nonintervened vessel was judged suitable for a safe IVUS analysis.

Analysis of 1 year virtual histology changes in coronary plaque located behind the struts of the everolimus eluting bioresorbable vascular scaffold.

Serial intravascular ultrasound virtual histology (IVUS-VH) after implantation of metallic stents has been unable to show any changes in the composition of the scaffolded plaque overtime. The everolimus-eluting ABSORB scaffold potentially allows for the formation of new fibrotic tissue on the scaffolded coronary plaque during bioresorption. We examined the 12 month IVUS-VH changes in composition of the plaque behind the struts (PBS) following the implantation of the ABSORB scaffold.

Simvastatin promotes osteogenic differentiation of mouse embryonic stem cells via canonical Wnt/β-catenin signaling.

Simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, has been known to reduce cholesterol biosynthesis. However, recent studies demonstrate that simvastatin shows diverse cholesterol-independent functions including cellular differentiation. In this study, we investigated the stimulatory effect of simvastatin on the osteogenic differentiation of mouse embryonic stem cells (ESCs).

Skin and soft tissue infections: experience over a five-year period and clinical usefulness of ultrasonography-guided gun biopsy-based culture.

Background: Skin and soft tissue infections (SSTIs) are common clinical diseases, but only a few reports of microbiological data on SSTIs in Korea have been published. In practice, specimens are rarely obtained from infected lesions unless there is visible pus or an abscess pocket. However, identification of the causative pathogen is important, because of emerging drug resistance and the increase in immunocompromised hosts.

New insights into the coronary artery bifurcation hypothesis-generating concepts utilizing 3-dimensional optical frequency domain imaging.

Coronary artery bifurcations are a common challenging lesion subset accounting for approximately 10% to 20% of all percutaneous coronary interventions. The provisional T-stenting approach is generally recommended as the first-line management of most lesions. Carina shift is suggested to be the predominant mechanism of side-branch pinching during provisional T-stenting and has been indirectly inferred from bench work and other intravascular imaging modalities.

Immunogenicity and safety of the influenza A/H1N1 2009 inactivated split-virus vaccine in young and older adults: MF59-adjuvanted vaccine versus nonadjuvanted vaccine.

Since initial reports in April 2009, the pandemic influenza A (H1N1) virus has spread globally. Influenza vaccines are the primary method for the control of influenza and its complications. We conducted a multicenter clinical trial to evaluate the immunogenicity and safety of H1N1 vaccine (Green Cross Co.

Clinical, laboratory and radiologic characteristics of 2009 pandemic influenza A/H1N1 pneumonia: primary influenza pneumonia versus concomitant/secondary bacterial pneumonia.

Background: Although influenza virus usually involves the upper respiratory tract, pneumonia was seen more frequently with the 2009 pandemic influenza A/H1N1 than with seasonal influenza.

Methods: From September 1, 2009, to January 31, 2010, a specialized clinic for patients (aged ≥15 years) with ILI was operated in Korea University Guro Hospital. RT-PCR assay was performed to diagnose 2009 pandemic influenza A/H1N1.

β-Catenin mediates cyclic strain-stimulated cardiomyogenesis in mouse embryonic stem cells through ROS-dependent and integrin-mediated PI3K/Akt pathways.

Wnt/β-catenin signaling regulates various cellular events involved in the proliferation and differentiation and these events are affected sensitively by applying to mechanical stimuli. However, the mechanisms by which mechanical force stimulates cardiomyogenesis are not extensively explored. In this study we investigated the cellular mechanisms by which β-catenin signaling regulates cardiac differentiation of strain-subjected embryonic stem (ES) cells.

Ketal cross-linked poly(ethylene glycol)-poly(amino acid)s copolymer micelles for efficient intracellular delivery of doxorubicin.

A biocompatible, robust polymer micelle bearing pH-hydrolyzable shell cross-links was developed for efficient intracellular delivery of doxorubicin (DOX). The rationally designed triblock copolymer of poly(ethylene glycol)-poly(L-aspartic acid)-poly(L-phenylalanine) (PEG-PAsp-PPhe) self-assembled to form polymer micelles with three distinct domains of the PEG outer corona, the PAsp middle shell, and the PPhe inner core. Shell cross-linking was performed by the reaction of ketal-containing cross-linkers with Asp moieties in the middle shells.

Clinical and microbiological characterization of carbapenem-resistant Acinetobacter baumannii bloodstream infections.

The incidence of carbapenem-resistant Acinetobacter baumannii infection is increasing, which might be associated with high morbidity and mortality among critically ill patients with limited therapeutic options. This study was conducted to evaluate the clinical and microbiological features of carbapenem-resistant A. baumannii bacteraemia.