PURPOSE: The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS: Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS: The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

PURPOSE: Severe cutaneous adverse reactions (SCARs), including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) to antiepileptic drug (AED), are rare, but result in significant morbidity and mortality. We investigated the major culprit drugs, clinical characteristics, and clinical course and outcomes of AED-induced SCARs using a nationwide registry in Korea. METHODS: A total of 161 patients with AED-induced SCARs from 28 referral hospitals were analyzed. The causative AEDs, clinical characteristics, organ involvements, details of treatment, and outcomes were evaluated. We compared the clinical and laboratory parameters between SJS/TEN and DRESS according to the leading causative drugs. We further determined risk factors for prolonged hospitalization in AED-induced SCARs. RESULTS: Carbamazepine and lamotrigine were the most common culprit drugs causing SCARs. Valproic acid and levetiracetam also emerged as the major causative agents. The disease duration and hospital stay in carbamazepine-induced SJS/TEN were shorter than those in other AEDs (P< 0.05, respectively). In younger patients, lamotrigine caused higher incidences of DRESS than other drugs (P= 0.045). Carbamazepine, the most common culprit drug for SCARs, was associated with a favorable outcome related with prolonged hospitalization in SJS (odds ratio, 0.12; 95% confidence interval, 0.02-0.63, P= 0.12), and thrombocytopenia was found to be a risk factor for prolonged hospitalization in DRESS. CONCLUSION: This was the first large-scale epidemiological study of AED-induced SCARs in Korea. Valproic acid and levetiracetam were the significant emerging AEDs causing SCARs in addition to the well-known offending AEDs such as carbamazepine and lamotrigine. Carbamazepine was associated with reduced hospitalization, but thrombocytopenia was a risk factor for prolonged hospitalization. Our results suggest that the clinical characteristics and clinical courses of AED-induced SCARs might vary according to the individual AEDs.
Anticonvulsants ; Carbamazepine ; Cicatrix ; Drug Hypersensitivity Syndrome ; Epidemiologic Studies ; Hospitalization ; Humans ; Incidence ; Korea ; Length of Stay ; Mortality ; Referral and Consultation ; Risk Factors ; Stevens-Johnson Syndrome ; Thrombocytopenia ; Valproic Acid

OBJECTIVE: To investigate the magnetic resonance imaging (MRI) findings and the patterns of postoperative spinal infection according to the passage of time. METHODS: Institutional review board approval was obtained, and informed consent was not obtained for the retrospective review of patients’ medical records. A total of 43 patients (27 men and 16 women; mean age, 64) diagnosed with postoperative spinal infection were included in this study. We retrospectively reviewed the MRI findings and the medical records and categorized the infection sites based on MRI, i.e., anterior, posterior, and both parts. The duration of the clinical onset from surgery was divided, i.e., acute (≤2 weeks), subacute (2–4 weeks), and late (>4 weeks). RESULTS: Postoperative spinal infection was involved in the posterior part in 31 (72%), anterior part in two (4.7%), and both parts in 10 patients (23.3%). Abscess or phlegmon in the back muscles and laminectomy site were the most common MRI findings. The number of patients with acute, subacute, and late clinical onset were 35, two, and six, respectively (mean, 33.4 days; range, 1–730 days). The mean duration of the clinical onset was 12 days in the posterior part, 15.2 days in both parts, and 456.5 days in the anterior part. CONCLUSION: Postoperative spinal infection usually occurred within four weeks in the posterior part and over time the infection was considered to spread into the anterior part. For the evaluation of postoperative spinal infection, the posterior surgical field was more important than the vertebral body or the disc space on MRI.
Abscess ; Back Muscles ; Cellulitis ; Discitis ; Ethics Committees, Research ; Female ; Humans ; Informed Consent ; Laminectomy ; Magnetic Resonance Imaging* ; Male ; Medical Records ; Retrospective Studies ; Spine ; Spondylitis

PURPOSE: There was a global increase in the prevalence of oseltamivir-resistant influenza viruses during the 2007-2008 influenza season. This study was conducted to investigate the occurrence and characteristics of oseltamivir-resistant influenza viruses during the 2007-2008 and 2008-2009 influenza seasons among patients who were treated with oseltamivir (group A) and those that did not receive oseltamivir (group B). METHODS: A prospective study was conducted on 321 pediatric patients who were hospitalized because of influenza during the 2007-2008 and 2008-2009 influenza seasons. Drug resistance tests were conducted on influenza viruses isolated from 91 patients. RESULTS: There was no significant difference between the clinical characteristics of groups A and B during both seasons. Influenza A/H1N1, isolated from both groups A and B during the 2007-2008 and 2008-2009 periods, was not resistant to zanamivir. However, phenotypic analysis of the virus revealed a high oseltamivir IC50 range and that H275Y substitution of the neuraminidase (NA) gene and partial variation of the hemagglutinin (HA) gene did not affect its antigenicity to the HA vaccine even though group A had a shorter hospitalization duration and fewer lower respiratory tract complications than group B. In addition, there was no significant difference in the clinical manifestations between oseltamivir-susceptible and oseltamivir-resistant strains of influenza A/H1N1. CONCLUSION: Establishment of guidelines to efficiently treat influenza with oseltamivir, a commonly used drug for treating influenza in Korean pediatric patients, and a treatment strategy with a new therapeutic agent is required.
Child ; Drug Resistance ; Hemagglutinins ; Hospitalization ; Humans ; Influenza, Human ; Inhibitory Concentration 50 ; Neuraminidase ; Orthomyxoviridae ; Oseltamivir ; Prevalence ; Prospective Studies ; Respiratory System ; Seasons ; Viruses ; Zanamivir

BACKGROUND/AIMS: Low-dose metronomic chemotherapy involves the frequent administration of comparatively low doses of cytotoxic agents with no extended breaks, and it may be as efficient as and less toxic than the conventional maximum tolerated dose therapy. This study evaluated the feasibility and therapeutic efficacy of metronomic chemotherapy in patients with advanced hepatocellular carcinoma (HCC) with major portal vein thrombosis (PVT). METHODS: Thirty consecutive HCC patients with major PVT with or without extrahepatic metastasis were prospectively allocated to metronomic chemotherapy consisting of epirubicin being infused through the correct hepatic artery at a dose of 30 mg/body surface area (BSA) every 4 weeks, and cisplatin (15 mg/BSA) and 5-fluorouracil (50 mg/BSA) every week for 3 weeks, with intervening 1 week breaks. The treatment response was assessed using response evaluation criteria in solid tumors (RECIST). RESULTS: In total, 116 cycles of metronomic chemotherapy were administered to the 30 patients, with a median of 3 cycles given to individual patients (range, 1-15 cycles). Six patients (20.0%) achieved a partial response and six patients (20.0%) had stable disease. The median time to disease progression and overall survival were 63 days (range, 26-631 days) and 162 days (95% confidence interval; range, 62-262 days), respectively. Overall survival was significantly associated with baseline alpha-fetoprotein level (P=0.001) and tumor response (P=0.005). The baseline alpha-fetoprotein level was significantly associated with the disease control rate (P=0.007). Adverse events were tolerable and managed successfully with conservative treatment. CONCLUSIONS: Metronomic chemotherapy may be a safe and useful palliative treatment in HCC patients with major PVT.
Administration, Metronomic ; Adult ; Aged ; Antineoplastic Agents/administration & dosage ; Carcinoma, Hepatocellular/complications/*drug therapy/mortality ; Cisplatin/administration & dosage ; Epirubicin/administration & dosage ; Female ; Fluorouracil/administration & dosage ; Humans ; Kaplan-Meier Estimate ; Liver Neoplasms/complications/*drug therapy/mortality ; Male ; Middle Aged ; *Portal Vein ; Prognosis ; Tomography, X-Ray Computed ; Venous Thrombosis/complications/*diagnosis ; alpha-Fetoproteins/analysis

The Streptococcus milleri group, which also includes S. anginosus, S. intermedius and S. constellatus, is found in the oropharynx, upper respiratory tract, gastrointestinal tract, and urogenital tract mucosa. Bacteria in the Streptococcus milleri group are associated with bacteremia and abscess formation. Most of the reports of of Streptococcus milleri group (SMG) infection occur in patients with underlying medical conditions. Predisposing factors that have been associated with S. milleri group empyema include mucosal disturbances (sinusitis, periodontal disease, enteric disease), preceding to pneumonia, thoracic surgery, malignancy, neurological disease, alcohol abuse, and also diabetes mellitus. We report on a 42-year-old man with mental retardation. He who suffered from dyspnea and a fever that he had developed for over 14 days. S. constellatus and anaerobic bacterias (Prevotella buccae and Micromonas micros) were cultured. The patient was treated with the drainage of pleural effusion and clindamycin and levofloxacin.
Abscess ; Adult ; Alcoholism ; Bacteremia ; Bacteria ; Bacteria, Anaerobic ; Cheek ; Clindamycin ; Diabetes Mellitus ; Drainage ; Dyspnea ; Empyema ; Fever ; Gastrointestinal Tract ; Humans ; Intellectual Disability ; Mucous Membrane ; Ofloxacin ; Oropharynx ; Periodontal Diseases ; Pleural Effusion ; Pneumonia ; Respiratory System ; Streptococcus ; Streptococcus constellatus ; Streptococcus milleri Group ; Thoracic Surgery

Bortezomib is an inhibitor of 26S proteasome, which is an effective treatment for multiple myeloma. The common adverse effects of bortezomib are asthenic conditions, gastrointestinal disturbances, and peripheral neuropathy. Here we describe a patient with dyspnea and general weakness because of complete atrioventricular block while receiving bortezomib. We immediately stopped bortezomib, and after inserting a permanent VDD pacemaker, the patients' symptoms disappeared.
Atrioventricular Block/*chemically induced ; Boronic Acids/*adverse effects/*therapeutic use ; Female ; Humans ; Middle Aged ; Multiple Myeloma/*drug therapy ; Pyrazines/*adverse effects/*therapeutic use

Bortezomib is an inhibitor of 26S proteasome, which is an effective treatment for multiple myeloma. The common adverse effects of bortezomib are asthenic conditions, gastrointestinal disturbances, and peripheral neuropathy. Here we describe a patient with dyspnea and general weakness because of complete atrioventricular block while receiving bortezomib. We immediately stopped bortezomib, and after inserting a permanent VDD pacemaker, the patients' symptoms disappeared.
Atrioventricular Block/*chemically induced ; Boronic Acids/*adverse effects/*therapeutic use ; Female ; Humans ; Middle Aged ; Multiple Myeloma/*drug therapy ; Pyrazines/*adverse effects/*therapeutic use

Endovascular treatment of ethmoidal dural arteriovenous fistula (DAVF) has not been widely performed because of the technical difficulty of the procedure and the potential risk of central retinal artery occlusion. We report the case of a patient who underwent Onyx embolization through the ophthalmic artery in bilateral ethmoidal DAVF; to our best knowledge this is the first report.
Central Nervous System Vascular Malformations ; Humans ; Ophthalmic Artery ; Retinal Artery Occlusion

We developed a high-resolution micro-CT system based on rotational gantry and flat-panel detector for live mouse imaging. This system is composed primarily of an x-ray source with micro-focal spot size, a CMOS (complementary metal oxide semiconductor) flat panel detector coupled with CsI (Tl) (thallium-doped cesium iodide) scintillator, a linearly moving couch, a rotational gantry coupled with positioning encoder, and a parallel processing system for image data. This system was designed to be of the gantry-rotation type which has several advantages in obtaining CT images of live mice, namely, the relative ease of minimizing the motion artifact of the mice and the capability of administering respiratory anesthesia during scanning. We evaluated the spatial resolution, image contrast, and uniformity of the CT system using CT phantoms. As the results, the spatial resolution of the system was approximately the 11.3 cycles/mm at 10% of the MTF curve, and the radiation dose to the mice was 81.5 mGy. The minimal resolving contrast was found to be less than 46 CT numbers on low-contrast phantom imaging test. We found that the image non-uniformity was approximately 70 CT numbers at a voxel size of ~55x55x100micrometer3. We present the image test results of the skull and lung, and body of the live mice.
Anesthesia ; Animals ; Artifacts ; Cesium ; Lung ; Mice ; Skull