Background/Aims: Although anti-hepatitis C virus (HCV) assay is widely used to screen for HCV infection, it has a high false-positive (FP) rate in low-risk populations. We investigated the accuracy of anti-HCV signal-to-cutoff (S/CO) ratio to distinguish true-positive (TP) from FP HCV infection. Methods: We retrospectively analyzed 77,571 patients with anti-HCV results. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic accuracy of anti-HCV S/CO ratio in anti-HCV positive patients. Results: Overall, 1,126 patients tested anti-HCV positive; 34.7% of patients were FP based on HCV RNA and/or recombinant immunoblot assay (RIBA) results. The age and sex-adjusted anti-HCV prevalence was 1.22%. We identified significant differences in serum aspartate transaminase and alanine transaminase levels, anti-HCV S/CO ratio, and RIBA results between groups (viremia vs. non-viremia, TP vs. FP). Using ROC curves, the optimal cutoff values of anti-HCV S/CO ratio for HCV viremia and TP were 8 and 5, respectively. The area under the ROC curve, sensitivity, specificity, positive and negative predictive values were 0.970 (95% CI, 0.959–0.982, p < 0.001), 99.7%, 87.5%, 87.4%, and 99.7%, respectively, for predicting HCV viremia at an anti-HCV S/CO ratio of 8 and 0.987 (95% CI, 0.980–0.994, p < 0.001), 95.3%, 94.7%, 97.1%, and 91.4%, respectively, for TP HCV infection at an anti-HCV S/CO ratio of 5. No patients with HCV viremia had an anti-HCV S/CO ratio below 5. Conclusions The anti-HCV S/CO ratio is highly accurate for discriminating TP from FP HCV infection and should be considered when diagnosing HCV infections.

Background: Bisphosphonates (BP), a commonly used medication for various bone diseases, have been known to have severe complications such as bisphosphonate-related osteonecrosis of the jaw (BRONJ). Failure of dental implants has also been found in patients with medication-related osteonecrosis of the jaw (MRONJ). In this study, we analyzed the necrotic bone tissues and the surface of the failed implants removed from the jaw in patients treated with BPs and antiresorptive agents. Results: Chronic inflammatory cells with collagen and fibrous tissues and bone sequestrum were shown at 5.0 × , 10.0 × , 20.0 × , and 40.0 × magnified histologic sections in the bone and fibrotic scar tissues removed from patients with MRONJ due to osteonecrosis. Hardened bone tissues with microcracked bony resorbed lacunae were observed in SEM. Unlike the previously published comparative data where immune cells, such as dendritic cells, were found in the failed implant surface, these immune cells were not identified in the BRONJ-related peri-implantitis tissues through the TEM investigations. Furthermore, EDS revealed that in addition to the main titanium element, gold, car‑ bon, oxygen, calcium, phosphorus, silicon, and sulfur elements were found. Conclusion Hardened bone tissues with microcracked bony resorbed lacunae were observed in the SEM findings, which were considered as the main characteristic of the osteonecrosis of the jaw. Immune cells, such as dendritic cells were not identified in the TEM. EDS showed that in addition to the main titanium element, gold, carbon, oxygen, calcium, phosphorus, and silicon elements were found. Furthermore, it was revealed that sulfur was found, which was considered to be one of the complicated causes of implant failure in patients with BRONJ.

Background: Recently developed imaging techniques, such as cone beam computed tomography (CBCT) and CAD/CAM technology, have facilitated reliable implant planning and implant surgical guide production by 3D printing. This study compared the accuracy of implant-guided surgery using the R2GATE® program with CBCT before and after surgery. Patients and methods: The study included patients who visited the Department of Oral and Maxillofacial Surgery at Chonnam National University Hospital from September 2021 to March 2022. Twenty-four implants were placed in eleven patients. Using R2GATE® Windows (Megagen implant, Daegu, Korea) software, implant placement was planned. The difference was measured by the CBCT before and after surgery. The cervical and apical distance and angular deviation of the implants were measured. Statistical analysis was performed using an independent t-test, Pearson correlation, and multiple regression analyses. Results: The three-dimensional linear distance difference between the planned implant and the placed implant was 0.97 ± 0.37 mm at the cervical and 1.13 ± 0.36 mm at the apical. The difference in angle deviation between the planned implant and the placed implant was 3.42 ± 2.12°. Among the variables affecting the accuracy of implant placement, a statistically significant difference was found when using a tissue-supported implant guide, implant diameter and implant length. Conclusion Based on these results, using the R2GATE® program is useful to use an implant digital surgical guide, and it will be used in various clinic.

Background: Nilotinib is a tyrosine kinase inhibitor approved by the Ministry of Food and Drug Safety for frontline and 2nd line treatment of Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). This study aimed to confirm the safety and efficacy of nilotinib in routine clinical practice within South Korea. Methods: An open-label, multicenter, single-arm, 12-week observational post-marketing surveillance (PMS) study was conducted on 669 Korean adult patients with Ph + CML from December 24, 2010, to December 23, 2016. The patients received nilotinib treatment in routine clinical practice settings. Safety was evaluated by all types of adverse events (AEs) during the study period, and efficacy was evaluated by the complete hematological response (CHR) and cytogenetic response. Results: During the study period, AEs occurred in 61.3% (410 patients, 973 events), adverse drug reactions (ADRs) in 40.5% (271/669 patients, 559 events), serious AEs in 4.5% (30 patients, 37 events), and serious ADRs in 0.7% (5 patients, 8 events). Furthermore, unexpected AEs occurred at a rate of 6.9% (46 patients, 55 events) and unexpected ADRs at 1.2% (8 patients, 8 events). As for the efficacy results, CHR was achieved in 89.5% (442/494 patients), and minor cytogenetic response or major cytogenetic response was achieved in 85.8% (139/162 patients). Conclusion This PMS study shows consistent results in terms of safety and efficacy compared with previous studies. Nilotinib was well tolerated and efficacious in adult Korean patients with Ph + CML in routine clinical practice settings.

Background: Although neuromyelitis optica spectrum disorder (NMOSD) is known to be a rare disease, its prevalence and incidence have not yet been studied in Korea. We performed a population-based study to examine the prevalence and incidence of NMOSD in Korea using data from the Korean National Health Insurance (NHI) claims database. Methods: Data from 2013 to 2017 were obtained, with a washout period set as 2013 and 2014. The prevalence and incidence of NMOSD in 2016 and 2017 were calculated using population census data. Subjects were divided into 5 groups at 15-year intervals, depending on the age at which the diagnostic code was entered. The relative risk (RR) for each age group was compared with the oldest (≥ 60 years) age group. Results: The overall prevalence was estimated to be 3.36 and 3.56 per 100,000 individuals, with an incidence of 0.41 and 0.65 per 100,000 individuals-year in 2016 and 2017, respectively. The mean age was 43.08 (standard deviation, 14.56) years, and the ratio of male to females was 1:4.7. The incidence was higher in female individuals aged between 30 and 59 years (RR, 2.8–3.05; P < 0.05). Conclusion Nationwide prevalence of NMOSD in Korea was 3.36 and 3.56/100,000 and its incidence was 0.41 and 0.65/100,000-year in 2016 and 2017 respectively.

PURPOSE: The clinical characteristics and results of femoropopliteal artery injury (FPAI) remain unclear. In this study, we evaluated the outcomes and risk factors of limb loss in patients treated for FPAI. MATERIALS AND METHODS: We retrospectively reviewed data from a database of patients who underwent revascularization for an FPAI at a single institution between January 2013 and December 2017. We reviewed and analyzed the characteristics, postoperative results, and factors that influence amputation rates. RESULTS: Twenty-four femoropopliteal arterial reconstructions in 24 patients were included in this study. Among the patients were 20 (83.3%) male with a first-quartile age of 28 years and a third-quartile age of 45 years (range, 15–68 years). The mean injury severity score (ISS) was 16 (range, 4–55), and 5 patients (20.8%) had ISSs of >20 points. The mean mangled extremity severity score (MESS) was 3.8 (range, 1–11), and 8 patients (33.3%) had MESSs of >5 points. In terms of arterial reconstruction methods, autogenous saphenous vein grafting, vein patching, and primary closure were performed in 9 patients (37.5%), 4 patients (16.7%), and 11 patients (45.8%), respectively. Despite arterial reconstruction, 5 patients (20.8%) underwent above-knee amputation. ISSs of >20, MESSs of >7, and orthopedic fixation were statistically significant factors associated with amputation. CONCLUSION: In cases of FPAI with ISSs of >20, MESSs of >7, and orthopedic fixation, amputations should be considered. We were also careful to attempt limb salvage in such cases.
Amputation ; Amputation, Traumatic ; Arteries ; Extremities ; Femoral Artery ; Humans ; Injury Severity Score ; Limb Salvage ; Lower Extremity ; Male ; Orthopedics ; Popliteal Artery ; Retrospective Studies ; Risk Factors ; Saphenous Vein ; Transplants ; Vascular System Injuries ; Veins

BACKGROUND/AIMS: The association between Helicobacter pylori infection and nonsteroidal anti-inflammatory drugs (NSAIDs) or low-dose aspirin therapy as a risk factor for peptic ulcer bleeding (PUB) remains unclear. This study investigated the risk of PUB associated with H. pylori infection and NSAID or low-dose aspirin therapy in patients with PUD. MATERIALS AND METHODS: This case-control study investigated 340 patients with PUB between 2012 and 2016. The control group comprised age and sex-matched patients with endoscopically documented non-bleeding ulcers. Using logistic regression analysis, the adjusted odds ratio (AOR) was calculated for the risk of PUB. RESULTS: Of the patients investigated, 57.9% in the study group and 51.8% in the control group were diagnosed with H. pylori infection (P=0.106). Logistic regression analysis showed synergistic interaction between H. pylori infection and low-dose aspirin therapy. Multivariate analysis showed that low-dose aspirin (AOR 3.92, P < 0.001), NSAIDs (AOR 2.98, P=0.001), warfarin (AOR 14.57, P=0.011), gastric ulcer (compared with duodenal ulcer) (AOR 1.65, P=0.01), and smoking (AOR 1.97, P=0.004) increased the risk of PUB compared with the risk of PUD. CONCLUSIONS: Both NSAIDs and aspirin are independent risk factors for bleeding in patients with PUD. Additionally, low-dose aspirin therapy concomitant with H. pylori infection produced a synergistic effect. Therefore, H. pylori eradication may be crucial in aspirin users. Moreover, a proton pump inhibitor should be prescribed in patients with a history of bleeding ulcers who need long-term NSAID treatment.
Anti-Inflammatory Agents, Non-Steroidal ; Aspirin ; Case-Control Studies ; Helicobacter pylori ; Helicobacter ; Hemorrhage ; Humans ; Logistic Models ; Multivariate Analysis ; Odds Ratio ; Peptic Ulcer ; Proton Pumps ; Risk Factors ; Smoke ; Smoking ; Stomach Ulcer ; Ulcer ; Warfarin

BACKGROUND: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. METHODS: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson’s difficulty index (DI) and RID. RESULTS: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. CONCLUSIONS: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.
Alveolar Bone Loss ; Bone Regeneration ; Compensation and Redress ; Dental Caries ; Dental Cementum ; Follow-Up Studies ; Gingival Recession ; Molar ; Molar, Third ; Periodontal Pocket ; Retrospective Studies ; Tooth ; Tooth Cervix

BACKGROUND: Oral squamous cell carcinoma (OSCC) constitutes a group of tumors that exhibit heterogeneous biology, histopathology, and clinical behaviors.CASE PRESENTATION: A 73-year-old male had a whitish leukoplakia-like lesion around inflamed peri-implant area (#42, #43, and #44), and this lesion had transformed to OSCC within 3 years. He underwent mass resection, selective neck dissection, and reconstructive surgery. To detect any carcinogenesis progression, we examined the removed tumor tissue as well as the patient's preoperative and postoperative sera to identify causative oncogenic proteins using immunoprecipitation high-performance liquid chromatography (IP-HPLC). CONCLUSIONS The protein expression levels of p53, E-cadherin, β-catenin, MMP-10, HER2, NRAS, Met, HER2, and ERb were significantly lower in the serum collected on postoperative day 10 than in the preoperative serum, and if these proteins are consistently not elevated in the serum 3 months after surgery compared with the preoperative serum, these proteins can be potential oncogenic proteins. However, we also found that the serum extracted 3 months after the operation had elevated levels of oncogenic proteins compared with that of the preoperative and 10-day postoperative serum indicating the possibility of tumor recurrence. At postoperative follow-up period, ipsilateral neck metastasis and second primary lesion were found and additional surgery was performed to the patient. IP-HPLC using the patient's serum shows the possibility of oncogenic protein detection. However, follow-up IP-HPLC data is needed to find out patient-specific prognostic factors.

PURPOSE: The purpose of this study is to investigate differences in organ-specific cancer incidence according to the region and population size in Korea. MATERIALS AND METHODS: We reviewed the data of the cancer registration program of Gyeongnam Regional Cancer Center between 2008 and 2011. Age-standardized rates of cancer incidence were analyzed according to population size of the region and administrative zone. RESULTS: Incidence of thyroid cancer has been increasing rapidly in both urban and rural areas. However, the thyroid cancer incidence was much lower in rural areas than in urban areas and megalopolis such as Seoul. Gastric cancer was relatively more common in rural areas, in megalopolis near the sea (Ulsan, Busan, and Incheon), and other southern provinces (Chungcheongnam-do, Gyeongsangbuk-do, and Gyeongsangnam-do). A detailed analysis in Gyeongsangnam-do revealed that rural areas have relatively low incidence of thyroid and colorectal cancer, and relatively high incidence of gastric and lung cancer compared to urban areas. CONCLUSION: This study suggests that there are some differences in cancer incidence by population size. Thyroid and colorectal cancer incidence was increasing, and gastric and lung cancer was slightly decreasing in urban areas, whereas gastric and lung cancer incidence still remains high in rural areas.
Busan ; Colorectal Neoplasms ; Epidemiology ; Gyeongsangbuk-do ; Gyeongsangnam-do ; Incidence* ; Korea* ; Lung Neoplasms ; Population Density ; Rural Population ; Seoul ; Stomach Neoplasms ; Thyroid Gland ; Thyroid Neoplasms ; Urbanization