An empirical analysis of the state of competition in OECD mobile wireless markets

Contra the current trend of deregulation, mobile wireless markets in the OECD member states appear, until recently, to have been more or less concentrated. The study estimates the equations for market concentration, mobile prices, and profits using annual panel data from 24 OECD member states for the 1998-2009 period, in order to assess their interaction. Mobile prices, measured by revenue per minute in constant USD PPP, are regarded as a direct measure of consumer welfare. Estimation results indicate that in the second half of the 2000s, market concentration had no effect on mobile prices, whereas the positive relationship between market concentration and profits persisted. In other words, the market-power hypothesis is rejected in the second half of the 2000s. This empirical result provides a strong case for a recent lenient approach towards regulation and merger attempts in OECD mobile wireless markets. Additionally, the study provides evidence that regulatory policies have affected mobile market structure and performance

Impact of Toxocariasis in Patients with Unexplained Patchy Pulmonary Infiltrate in Korea

Toxocariasis is one of the causes of pulmonary eosinophilic infiltrate that is increasing in Korea. This study was designed to identify the prevalence of toxocara seropositivity in patients with unexplained pulmonary patchy infiltrate and to evaluate associated factors. We evaluated 102 patients with unexplained pulmonary patchy infiltrate on chest computed tomography (CT) scan. As a control set, 116 subjects with normal chest CT were also evaluated. History of allergic disease, drug use, parasitic disease and raw cow liver intake were taken. Blood eosinophil count and total IgE level were measured. Specific serum IgG antibody to Toxocara canis larval antigen and specific IgG antibodies to 4 other parasites were measured by enzyme-linked immunosorbent assay (ELISA). In the infiltrate group, 66.7% subjects were toxocara seropositive whereas 22.4% of the control group were seropositive (p<0.001). In the infiltrate group, patients with a history of eating raw cow liver (odds ratio [OR], 7.8) and patients with eosinophilia (OR, 5.2) had a higher incidence of toxocara seropositivity. Thirty-five percent of toxocara seropositive patients with infiltrate exhibited migrating infiltrate and 48% had decreased infiltrate on the follow-up CT. We recommend that toxocara ELISA should be performed in patients with unexplained pulmonary patchy infiltrate, and that the eating of raw cow liver should be actively discouraged

Effect of 457 nm Diode-Pumped Solid State Laser on the Polymerization Composite Resins: Microhardness, Cross-Link Density, and Polymerization Shrinkage

Objective: The purpose of the present study was to test the usefulness of 457 nm diode-pumped solid state (DPSS) laser as a light source to cure composite resins. Materials and methods: Five different composite resins were light cured using three different light-curing units (LCUs): a DPSS 457 nm laser (LAS), a light-emitting diode (LED), and quartz-tungsten-halogen (QTH) units. The light intensity of LAS was 560 mW/cm2, whereas LED and QTH LCUs was ∼900 mW/cm2. The degree of polymerization was tested by evaluating microhardness, cross-link density, and polymerization shrinkage. Results: Before water immersion, the microhardness of laser-treated specimens ranged from 40.8 to 84.7 HV and from 31.7 to 79.0 HV on the top and bottom surfaces, respectively, and these values were 3.3–23.2% and 2.9–31.1% lower than the highest microhardness obtained using LED or QTH LCUs. Also, laser-treated specimens had lower top and bottom microhardnesses than the other LCUs treated specimens by 2.4–19.4% and 1.4–27.8%, respectively. After ethanol immersion for 24 h, the microhardness of laser-treated specimens ranged from 20.3 to 63.2 HV on top and bottom surfaces, but from 24.9 to 71.5 HV when specimens were cured using the other LCUs. Polymerization shrinkage was 9.8–14.7 μm for laser-treated specimens, and these were significantly similar or lower (10.2–16.0 μm) than those obtained using the other LCUs. Conclusions: The results may suggest that the 457 nm DPSS laser can be used as a light source for light-curing dental resin composites

Incidence of gestational trophoblastic disease in South Korea: a longitudinal, population-based study

Introduction We investigated the rate and longitudinal trends of gestational trophoblastic disease (GTD) incidence in the Republic of Korea between 2009 and 2015 using population-based data. Materials and Methods Data of patients diagnosed with GTD from 2009 to 2015 were obtained from the Health Insurance Review and Assessment Service/National Inpatient Sample (HIRA-NIS) in the Republic of Korea. The HIRA annually provides the HIRA-NIS, a collection of clinical data from over one million people. For each year, the HIRA-NIS extracted records of 13% of patients admitted at any one time during the year and 1% of all remaining patients using the weighted sample method. Results Medical records of 370,117 women with at least one pregnancy (GTD, ectopic pregnancy, abortion, or delivery) were extracted from a total of 4,476,495 records. Of these, 372 episodes of GTD were identified in women with a mean age of 35.4 ± 0.7 years. The incidence rate of GTD was 130 ± 10 cases per 100,000 pregnancies, which was classified as hydatidiform mole (HM), invasive mole, or malignant neoplasm of the placenta with incidence rates of 110 ± 10, 20 ± 0, or 10 ± 0 cases per 100,000 pregnancies, respectively. Incidence of GTD was lowest among women in their late 20 s and early 30 s. Occurrences of HM accounted for 80.3% all GTD cases. Weighted logistic analysis indicated that while age significantly affected the incidence of GTD (odds ratio (OR): 2.46; 95% confidence interval (CI) [1.79–3.37]; P < 0.001), socioeconomic status did not (OR: 1.94; 95% CI [1.0–3.79]; P = 0.05). Conclusions In the Republic of Korea, we observed overall incidence rates of GTD and HM of 1.3 and 1.1 per 1,000 pregnancies, respectively, which are similar to those reported in recent Western population-based studies. We also noted that annual incidence rates of GTD stabilized from 2009 to 2015

Primary Adenosquamous Cell Carcinoma of the Pancreas: A Case Report with a Review of the Korean Literature

The most common pancreatic cancer is adenocarcinoma. Primary adenosquamous cell carcinoma of the pancreas is very rare and aggressive. A 46-year-old man presented with a 3-month history of dyspepsia and a 7-kg weight loss. The physical examination showed tenderness of the right upper quadrant of the abdomen. There was no jaundice. Amylase and lipase were elevated. CA 19-9 was elevated to 566.7 U/mL. Gastroduodenoscopy showed a hard ulceroinfiltrative mass with a yellowish exudate that bled readily on touch in the second portion of the duodenum. Abdominal computed tomography showed a 7.1 × 6.3-cm heterogeneously enhancing mass in the pancreatic head. The pancreatic mass had invaded the duodenum wall, gastric antrum, and gastroduodenal artery sheath. Fine-needle aspiration biopsy of the pancreatic mass revealed adenosquamous cell carcinoma, anaplastic type. We concluded that an adenosquamous cell carcinoma of pancreas had invaded the duodenal mucosa causing ulceration

A Case of Ischemic Colitis Associated with the Herbal Food Supplement Ma Huang

Ischemic colitis is a condition that usually occurs in the elderly, as a form of vascular disease. However, ischemic colitis also occurs, though rarely, in healthy young adults. Moreover, food supplements containing Ephedra sinica or ma huang have been linked to adverse central nervous and cardiovascular events. A 40-year-old man was admitted to our emergency department after 2 episodes of abdominal pain and bloody diarrhea that lasted 24 hours. His medical history was unremarkable for risk factors of bowel ischemia, except for well-controlled hypertension. However, a weight-loss supplement, Ephedra sinica, had been prescribed for daily use during the previous month. Both abdominal/pelvic computed tomography and colonoscopy revealed findings compatible with ischemic colitis. His conditions spontaneously improved without any serious complications, and he was advised to discontinue the use of herbal medications containing ephedrine. In this paper, we describe a case of ischemic colitis that was potentially linked to the use of ma huang with a review of the relevant literature

Sulforaphane Increases Cyclin-Dependent Kinase Inhibitor, p21 Protein in Human Oral Carcinoma Cells and Nude Mouse Animal Model to Induce G2/M Cell Cycle Arrest

Previously, our group reported that sulforaphane (SFN), a naturally occurring chemopreventive agent from cruciferous vegetables, effectively inhibits the proliferation of KB and YD-10B human oral squamous carcinoma cells by causing apoptosis. In this study, treatment of 20 and 40 µM of SFN for 12 h caused a cell cycle arrest in the G2/M phase. Cell cycle arrest induced by SFN was associated with a significant increase in the p21 protein level and a decrease in cyclin B expression, but there was no change in the cyclin A protein level. In addition, SFN increased the p21 promoter activity significantly. Furthermore, SFN induced p21 protein expression in a nude mouse xenograft model suggesting that SFN is a potent inducer of the p21 protein in human oral squamous carcinoma cells. These findings show that SFN is a promising candidate for molecular-targeting chemotherapy against human oral squamous cell carcinoma

Infectious Mononucleosis Hepatitis in Young Adults: Two Case Reports

Infectious mononucleosis due to Epstein-Barr virus (EBV) infection sometimes causes acute hepatitis, which is usually self-limiting with mildly elevated transaminases, but rarely with jaundice. Primary EBV infection in children is usually asymptomatic, but in a small number of healthy individuals, typically young adults, EBV infection results in a clinical syndrome of infectious mononucleosis with hepatitis, with typical symptoms of fever, pharyngitis, lymphadenopathy, and hepatosplenomegaly. EBV is rather uncommonly confirmed as an etiologic agent of acute hepatitis in adults. Here, we report two cases: the first case with acute hepatitis secondary to infectious mononucleosis and a second case, with acute hepatitis secondary to infectious mononucleosis concomitantly infected with hepatitis A. Both cases involved young adults presenting with fever, pharyngitis, lymphadenopathy, hepatosplenomegaly, and atypical lymphocytosis confirmed by serologic tests, liver biopsy and electron microscopic study