An electronic device for accelerating bone formation in tissues surrounding a dental implant.

A dental implant is a unique structure which can be used with a noninvasive method because it is inserted into the bone in part and extended extracorporally. This study presents an electronic device that is temporarily connected with the dental implant, and reports its effect on accelerating bone formation in the surrounding tissues in a canine mandibular model. A small sized and low power consumption biphasic electrical current (BEC) stimulator ASIC was developed and the surrounding tissue was exposed to continuous BEC stimulation for 7 days with the parameters of 20 microA/cm(2), 125 micros duration, and 100 pulses/s.

Synergistic effect of ERK inhibition on tetrandrine-induced apoptosis in A549 human lung carcinoma cells.

Tetrandrine (TET), a bis-benzylisoquinoline alkaloid from the root of Stephania tetrandra, is known to have anti-tumor activity in various malignant neoplasms. However, the precise mechanism by which TET inhibits tumor cell growth remains to be elucidated. The present studies were performed to characterize the potential effects of TET on phosphoinositide 3-kinase/Akt and extracellular signal-regulated kinase (ERK) pathways since these signaling pathways are known to be responsible for cell growth and survival.

In vitro response of primary human bone marrow stromal cells to recombinant human bone morphogenic protein-2 in the early and late stages of osteoblast differentiation.

A number of factors must be added to human bone marrow stromal cells (hBMSCs) in vitro to induce osteogenesis, including ascorbic acid (AA), beta-glycerophosphate (GP), and dexamethasone (Dex). Bone morphogenic protein (BMP)-2 is an osteoinductive factor that can commit stromal cells to differentiate into osteoblasts. However, it is still not clear whether the addition of BMP-2 alone in vitro can induce hBMSCs to complete osteoblast differentiation, resulting in matrix mineralization.

Hepatitis C virus nonstructural 4B protein modulates sterol regulatory element-binding protein signaling via the AKT pathway.

Hepatitis C virus (HCV) infection is often associated with hepatic steatosis and yet the molecular mechanisms of HCV-associated steatosis are poorly understood. Because sterol regulatory element-binding proteins (SREBPs) are the major transcriptional factors in lipogenic gene expression including fatty acid synthase (FAS), we examined the effects of HCV nonstructural proteins on the signaling pathways of SREBP. In this study, we demonstrated that HCV nonstructural 4B (NS4B) protein increased the transcriptional activities of SREBPs.

Increased expression of pigment epithelium-derived factor in allergic rhinitis.

Objectives: To investigate the expression of messenger RNA (mRNA) of the gene for pigment epithelium-derived factor (PEDF) (OMIM *172860) and PEDF protein and to localize the PEDF protein in the nasal mucosa of patients with allergic rhinitis and of control subjects.

Design: Investigation of PEDF mRNA and PEDF protein expression in the nasal mucosa using reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemical staining.

Participants: We used inferior turbinate mucosal samples from 10 patients with allergic rhinitis and 10 matched healthy control subjects.

Extremely small-magnitude accelerations enhance bone regeneration: a preliminary study.

High-frequency, low-magnitude accelerations can be anabolic and anticatabolic to bone. We tested the hypothesis that application of these mechanical signals can accelerate bone regeneration in scaffolded and nonscaffolded calvarial defects. The cranium of experimental rats (n = 8) in which the 5-mm bilateral defects either contained a collagen scaffold or were left empty received oscillatory accelerations (45 Hz, 0.

The changes of MRSA infections in chronic suppurative otitis media.

Objectives: To investigate the epidemiologic and microbiological characteristics of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) infections in the otorrhea of chronic suppurative otitis media (COM) patients.

Design: Retrospective study of patients with newly identified MRSA infections from January 1998 through December 2006. A total of 2773 patients with a diagnosis of COM were included in this study.

Synthesis and characterization of matrix metalloprotease sensitive-low molecular weight hyaluronic acid based hydrogels.

Hyaluronic acid is a naturally derived glycosaminoglycan (GAG) involved in biological processes. A low molecular weight hyaluronic acid (50 kDa)-based hydrogel was synthesized using acrylated hyaluronic acid. Matrix metalloproteinase (MMP) sensitive hyaluronic acid-based hydrogels were prepared by conjugation with two different peptides: cell adhesion peptides containing integrin binding domains (Arg-Gly-Asp: RGD) and a cross-linker with MMP degradable peptides to mimic the remodeling characteristics of natural extracellular matrices (ECMs) by cell-derived MMPs.

Characterization of low-molecular-weight hyaluronic acid-based hydrogel and differential stem cell responses in the hydrogel microenvironments.

Hyaluronic acid is a natural glycosaminoglycan involved in biological processes. Low-molecular-weight hyaluronic acid (10 and 50 kDa)-based hydrogel was synthesized using derivatized hyaluronic acid. Hyaluronic acid was acrylated by two steps: (1) introduction of an amine group using adipic acid dihydrazide, and (2) acrylation by N-acryloxysuccinimide.

Serum immunoglobulin fused interferon-alpha inhibited tumor growth in athymic mice bearing colon 26 adenocarcinoma cells.

Interferon (IFN) has therapeutic potential for a wide range of infectious and proliferative disorders. However, the half-life of IFN is too short to have a stable therapeutic effect. To overcome this problem, serum immunoglobulin has been fused to IFN.

Cancer survival in Korea 1993-2002: a population-based study.

Population-based survival reflect the average prognosis of unselected patients with a variety of natural histories as well as treatment patterns and are also useful for evaluating effectiveness and efficiency of cancer-directed health services in a given region. Although survival data have been reported based on hospital data, the survival data from population-based registry have been rarely reported in Korea. Based on the Korea National Cancer Incidence Database, we report the results from survival analysis for cancer patients diagnosed during 1993-2002 and followed up until 31 December 2005 at primary cancer sites.

Inhibition of HCV replicon cell growth by 2-arylbenzofuran derivatives isolated from Mori Cortex Radicis.

Medicinal herbs are increasingly used in the search for safe and efficient drug candidates for hepatitis C virus infection. In this study, we have investigated the anti-HCV effect of compounds from Mori Cortex Radicis. During a screening for extracts with anti-HCV affinity from medicinal plants (173 species), the methanol extract of Mori Cortex Radicis was selected.

Up-regulation of protease-activated receptor 2 in allergic rhinitis.

Objectives: We compared the patterns of PAR-2 messenger RNA (mRNA) and protein expression in the nasal mucosa of subjects with and without allergic rhinitis.

Methods: Biopsy specimens were obtained from 10 patients with allergic rhinitis and 10 normal controls. RNA was extracted from the nasal mucosa, and semiquantitative reverse transcription-polymerase chain reaction was performed for PAR-2.

Increasing trend in the incidence of cervical cancer among the elderly in Korea: a population-based study from 1993 to 2002.

Cancer is primarily a disease of older adults. However, little data is available on the clinical features of cervical cancer in elderly patients. We investigated the trends in incidence and clinical features associated with cervical cancer among the elderly in Korea during the period of 1993-2002.

Large hepatitis delta antigen modulates transforming growth factor-beta signaling cascades: implication of hepatitis delta virus-induced liver fibrosis.

Background & Aims: Transforming growth factor-beta (TGF-beta) has been implicated in the pathogenesis of liver disease. TGF-beta is involved in liver regeneration and in the fibrotic and cirrhotic transformation with hepatitis viral infection. Hepatitis delta virus (HDV) infection causes fulminant hepatitis and liver cirrhosis.

Bone regeneration using hyaluronic acid-based hydrogel with bone morphogenic protein-2 and human mesenchymal stem cells.

Acrylated hyaluronic acid (HA) was used as a scaffold for bone morphogenic protein-2 (BMP-2) and human mesenchymal stem cells (hMSCs) for rat calvarial defect regeneration. HA was acrylated by two-step reactions: (1) introduction of an amine group using adipic acid dihydrazide (ADH); (2) acrylation by N-acryloxysuccinimide. Tetrathiolated poly(ethylene) glycol (PEG-SH(4)) was used as a cross-linker by a Michael-type addition reaction and the hydrogel was formed within 10min under physiological conditions.

Up-regulation of peroxisome proliferator-activated receptor gamma in perennial allergic rhinitis.

Objectives: To investigate the expression of peroxisome proliferator-activated receptor gamma (PPAR-gamma) messenger RNA and protein and to localize the PPAR-gamma protein in the nasal mucosa of patients with allergic rhinitis and control subjects.

Design: Prospective study.

Setting: Tertiary academic institution.

Expressions of cyclooxygenase 1 and 2 in endotoxin-induced otitis media with effusion in the rat.

Objective: Recently, a selective COX-2 inhibitor was developed and used for reducing the levels of inflammation-inducing prostaglandin (PG) whilst not inhibiting the release of protective PG by COX-1. COX-1 may be the critical isoform required for the production of PG with a homeostatic function, whereas COX-2 may be the main contributor to PG production in inflammation. The purpose of this study was to investigate COX-1 and 2 expressions in experimental endotoxin-induced OME in rats and to quantify their temporal expressions.

Efficacy of sucralfate in the postoperative management of uvulopalatopharyngoplasty: a double-blind, randomized, controlled study.

Objective: To evaluate the effectiveness of sucralfate in influencing throat pain, otalgia, analgesic requirement, bleeding, mucosal recovery, and incidence of postoperative bleeding in patients undergoing uvulopalatopharyngoplasty.

Design: A prospective double-blind randomized study.

Setting: University-affiliated tertiary referral hospital.

Polymorphism of the CD14 gene in perennial allergic rhinitis.

Objectives: Allergic diseases have strong genetic backgrounds. Recently, a C-T polymorphism in the promoter region of CD14 has been associated with phenotypes of atopy in some populations. The aim of this study was to investigate the association of CD14/-159 polymorphism with total serum IgE levels and number of positive skin prick tests in Korean population with perennial allergic rhinitis.

Biphasic electric current stimulates proliferation and induces VEGF production in osteoblasts.

This study investigated biphasic electric current (BEC) functions as a new type of electrical stimulation to induce rat calvarial osteoblasts to proliferate, differentiate and synthesize cytokines. The culture system was designed so that biphasic current flowed between upper and lower gold plates. BEC helps to minimize the net charge accumulation during cell exposure to the electrical stimulation.

Expression of hepatitis C virus nonstructural 4B in transgenic mice.

Hepatitis C virus (HCV) is a pathogen that is of great medical significance in chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma worldwide. Although the HCV proteins have been intensively investigated over the past decade, the biochemical functions of the NS4B protein are still largely unknown. To investigate NS4B as a potential causative agent of liver disease, transgenic mice expressing the NS4B protein in liver tissue were produced.

Up-regulation of chemokine ligand 20 in chronic rhinosinusitis.

Objectives: To investigate the up-regulation of chemokine ligand 20 (CCL20) in chronic rhinosinusitis mucosa and to localize the distribution of CCL20 in the human paranasal sinus mucosa.

Design: Prospective study.

Setting: Tertiary academic institution.

Hepatitis C virus nonstructural 5B protein regulates tumor necrosis factor alpha signaling through effects on cellular IkappaB kinase.

Hepatitis C virus (HCV) NS5B protein is a membrane-associated phosphoprotein that possesses an RNA-dependent RNA polymerase activity. We recently reported that NS5A protein interacts with TRAF2 and modulates tumor necrosis factor alpha (TNF-alpha)-induced NF-kappaB and Jun N-terminal protein kinase (JNK). Since NS5A and NS5B are the essential components of the HCV replication complex, we examined whether NS5B could modulate TNF-alpha-induced NF-kappaB and JNK activation.

Up-regulation of peroxidase proliferator-activated receptor gamma in cholesteatoma.

Objective: To evaluate the localization and expression of peroxidase proliferator-activated receptor (PPAR)gamma in cholesteatoma epithelium.

Study Design: Experimental study.

Methods: Reverse-transcription polymerase chain reaction was performed on cholesteatoma tissues from 10 adult patients undergoing tympanomastoid surgery for middle ear cholesteatoma and on 10 samples of normal external auditory canal skin tissue.