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Background/Aims : Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy (SAA) is challenging to gastrointestinal endoscopists. The aim of this study was to evaluate the impact of scope exchange from a long single balloon enteroscope (SBE) to a gastroscope during SBE-assisted ERCP (SBE-ERCP) in patients with SAA. Methods Patients who underwent SBE-ERCP between February 2019 and October 2020 were retrospectively identified. Intubation success, scope exchange success, cannulation success, and therapeutic success were analyzed along with complications. Results Fifty-six patients with various SAAs underwent SBE-ERCP procedures, including Billroth II subtotal gastrectomy (B-II, n=13), pylorus-preserving pancreato-duodenectomy (PPPD, n=6), Roux-en-Y hepaticojejunostomy (REY HJ, n=4), and total gastrectomy with REY anastomosis (TG REY, n=33). Overall intubation, cannulation, and therapeutic success rates were 89.3%, 82.1%, and 82.1%, respectively. Therapeutic success rates did not differ significantly among the type of SAA. Successful scope exchange rate after successful intubation was significantly higher in native papilla (B-II and TG REY, 83.3%, 35/42) compared to bilioenteric anastomosis (PPPD and REY HJ, 0%, 0/8, p

BACKGROUND Cytomegalovirus (CMV) colitis is usually seen in immunocompromised patients with risk factors such as human immunodeficiency virus infection, solid organ transplant, inflammatory bowel disease, or malignancy. Therefore, many clinicians usually do not consider the possibility of CMV colitis in immunocompetent patients. We reported a rare case of segmental colonic hypoganglionosis associated with CMV colitis in an immunocompetent patient. CASE SUMMARY A 48-year-old woman with no underlying disease was admitted to our hospital for severe abdominal pain and constipation. Computed tomography of the abdomen showed diffuse dilatation of the small intestine and the entire colon. Initial sigmoidoscopic findings and result of polymerase chain reaction (PCR) for CMV revealed the compatible findings of CMV colitis, the patient was treated with intravenous ganciclovir. After treatment, sigmoidoscopic findings and CMV PCR results improved. However the patient continued to suffered from constipation. Eight months after the initial admission, patient visited the emergency department with severe abdominal pain and imaging revealed aggravation of fecal impaction and bowel dilatation. We performed subtotal colectomy to control patient’s symptom. Histological examination of the resected specimen showed significantly reduced number of mature ganglion cells in the sigmoid colon compared to that in the proximal colon. CONCLUSION Our case demonstrates that CMV colitis can develop even in patients with no other underlying disease, and that CMV colitis can be one of the causes for developing colonic hypoganglionosis.

Background/Aims: The study aimed to investigate the current practice patterns in the management of pancreatic cystic neoplasms in Korea.Methods: An electronic survey was systematically distributed by email to members of the Korean Pancreatobiliary Association from December 2019 to February 2020.Results: In total, 115 (110 gastroenterologists, five surgeons) completed the survey, 72.2% of whom worked in a tertiary/academic medical center. Most (65.2%) followed the 2012/2017 International Association of Pancreatology guidelines for the management of pancreatic cystic neoplasms. A gadolinium-enhanced magnetic resonance imaging/magnetic resonance cholangiopancreatography was the most common first-line diagnostic modality (42.1%), but a contrast-enhanced computed tomography scan was preferred as a subsequent surveillance tool (58.3%). Seventy- four percent of respondents routinely performed endoscopic ultrasound-guided fine needle aspiration for pancreatic cystic neoplasms with suspicious mural nodules. Endoscopic ultrasound-guided fine needle aspiration cytology (94.8%) and cystic fluid carcinoembryonic antigen (95.7%) were used for cystic fluid analysis. Most (94%) typically recommended surgery in patients with high-risk stigmata, but 18.3% also considered proceeding with surgery in patients with worrisome features. Most (96.5%) would continue surveillance of pancreatic cystic neoplasms for more than 5 years.Conclusions: According to this survey, there was variability in the management of pancreatic cystic neoplasms among the respondents. These results suggest that the development of evidence-based guidelines for pancreatic cystic neoplasms that fit the Korean practice is needed to create an optimal approach to the management of pancreatic cystic neoplasms.

Background Endoscopic ultrasound-guided fine needle aspiration or biopsy (EUS-FNA or FNB) has become a popular method for diagnosing various lesions of the gastrointestinal tract and surrounding tissue due to the accuracy and safety. To the best of our knowledge, no case report of severe infection after EUS-FNB of a solid lesion in the spleen has been described. Herein, we report a rare case of septic shock after EUS-FNB of a splenic mass. Case summary A 45-year-old male patient presented to the outpatient clinic due to an incidentally detected splenic mass. A definitive diagnosis could not be established based on the abdominal magnetic resonance imaging. EUS of the spleen showed a 6 cm-sized, relatively well-demarcated, heterogeneous mass, and EUS-FNB with a 22G needle was performed. Ten days after the procedure patient developed septic shock and a splenic abscess was identified. Blood culture revealed growth of Granulicatella adiacens. After the treatment with antibiotics the patient underwent surgical resection, and the pathological examination showed diffuse large B-cell lymphoma. The patient received chemotherapy and he is in complete remission. Conclusion Infection of a splenic mass after EUS-FNB is a rare complication and prophylactic antibiotics might be considered.

Sedation, defined as the depressed level of consciousness, induced by drug administration, is widely used for gastrointestinal endoscopy to relieve a patient’s anxiety and discomfort. In addition, successful procedure is anticipated with control of unintended movements. Endoscopic sedation, however, cannot be free from the risk of serious adverse events, e.g., cardiopulmonary compromise. Therefore, principles on personnel, facility and equipment, as well as performance itself, should be followed to prevent unfavorable incidents. In this article, sedation guidelines for the Accreditation of Qualified Endoscopy Units, issued by the Korean Society of Gastrointestinal Endoscopy, are presented.

Background/Aims Delayed gastric emptying (GE) is associated with high morbidity and mortality in subjects with diabetes. The aim of this study is to investigate associations between GE time and the major cardiovascular events (coronary heart diseases and ischemic stroke) in diabetic subjects with upper gastrointestinal (UGI) symptoms. Methods Among 259 subjects with chronic UGI symptoms who underwent gastric emptying study (GES) over 13 years, 122 diabetic subjects without gastric surgery and/or rapid GE were enrolled in this study. We also gathered data about baseline demographics, clinical characteristics, estimated GE half-time (GE T½) and incidence of cardiovascular events following GES. Results The mean age of subjects was 64.0 ± 17.4 years. There were 86 women and 104 subjects with type 2 diabetes. There were 52 (42.6%) subjects with normal GE, 50 (41.0.%) subjects with mild delayed GE, and 20 (16.4%) subjects with marked delayed GE. During follow-up (median, 207 weeks), cardiovascular events occurred in 7 (13.5%) subjects with normal GE, 4 (8.0%) subjects with mild delayed GE and 7 (35.0%) subjects with marked GE (P = 0.015). Univariate analysis showed that GE T½ was significantly associated with incidence of cardiovascular events (crude OR, 1.74; 95% CI, 1.12-2.69; P = 0.014). In a multivariate model, association between GE T½ and incidence of cardiovascular events remained statistically significant after adjustment for baseline characteristics and comorbidities (adjusted OR, 1.94; 95% CI, 1.21-3.12; P = 0.006). Conclusion A delay of GE was associated with an increased incidence of cardiovascular events in diabetic subjects with chronic UGI symptoms. (J Neurogastroenterol Motil 2019;25:387-393)

Unmanned aerial vehicle (UAV) communications over cellular networks are currently gaining increased interest because it can enable real-time control of UAVs and wide-area coverage. We discuss various challenges for future UAV cellular networks, where cellular networks with down-tilted antennas optimized for terrestrial users can extend terrestrial cellular services to aerial users. To overcome challenges such as large channel variation and UAV power consumption in UAV cellular networks, we propose a technique of preamble design for these networks using scalable sequences. Specifically, three types of scalable sequences are proposed for efficient use of battery power in UAVs, namely, maximum-length scalable sequence, Zadoff–Chu scalable sequence, and linear frequency modulated (LFM) scalable sequence. The properties of these scalable sequences are analyzed and compared through simulations in different channel environments.

Background Silibinin is a flavonoid with antihepatotoxic properties, and exhibits pleiotropic anticancer effects. However, the molecular mechanisms responsible for its anticancer actions in pancreatic cancer cells, and the effects on such cells and normal pancreatic cells, remain unclear. The objective of this study was to determine the effect of silibinin on human pancreatic cancer cells and normal ductal cells.Methods Human pancreatic cancer cells (MIA PaCa-2 and PANC-1) and normal ductal cells (hTERT-HPNE) were cultured with 0–400 μM silibinin for 48 h. Thereafter, the proliferation, invasion, apoptosis, and signaling pathways of the pancreatic cells were evaluated.Results Silibinin significantly inhibited the proliferation, invasion, and spheroid formation of human pancreatic cancer cells in vitro in a dose-dependent manner (p < 0.05). It also induced apoptosis in a dose-dependent manner. Western blot analysis showed that silibinin downregulated extracellular signaling-regulated kinase (ERK) and serine/threonine protein kinase (AKT) in human pancreatic cancer cells. It also upregulated microtubule associated protein 1 light chain 3 β (LC3B) and cleaved caspase-3 via c-Jun N-terminal kinases (JNK) signaling. On the other hand, silibinin increased the mRNA and protein levels of c-Jun, Twist-related protein 1, and Snail. It also decreased exogenous p53 levels, but increased endogenous c-Jun protein levels in human pancreatic cancer cells. However, silibinin did not affect cell viability and endogenous c-Jun levels in pancreatic normal ductal cells. It increased exogenous p53 levels, but decreased stemness-related gene expression in pancreatic normal ductal cells. Silibinin increased Ki-67 levels in pancreatic cancer cells, but decreased them in pancreatic normal ductal cells.Conclusion Silibinin not only exerted anticancer effects by inhibiting AKT–ERK and JNK signaling, but also upregulated cancer stemness–related genes in human pancreatic cancer cells. These results suggest that silibinin should be used as a therapeutic agent for human pancreatic cancer with caution.

Background Efficient ampullary intervention is essential for endoscopic retrograde cholangiopancreatography (ERCP) in patients with a prior Billroth II gastrectomy. We retrospectively evaluated the safety and effectiveness of ampullary intervention using fully covered self-expandable metal stents (FCSEMSs) for the management of common bile duct (CBD) stones in a subset of patients with a history of Billroth II gastrectomy. Methods This retrospective analysis involved patients with a prior Billroth II gastrectomy who underwent ampullary intervention with FCSEMSs for the management of CBD stones. The factors associated with FCSEMSs placement, treatment success, and procedural complications were analyzed. Results A group of 15 patients (10 males; median age, 78 years) underwent biliary metal stent placement for high degree of CBD angulation (6), small or flat papilla with unclear margin (5), current use of double antiplatelet agents or an anticoagulant (2), unwanted instrumentation of the cystic duct (1), and insecure position of the scope (1). Ampullary intervention with FCSEMSs was successful in all patients. After dilating the ampulla of Vater and building a durable conduit with FCSEMSs immediately, CBD stones were removed successfully from all patients in a single session. A mild post-ERCP pancreatitis occurred in one patient, who recovered without complications. Conclusion Ampullary intervention with FCSEMSs is safe and effective for the management of CBD stones in a subset of patients with a history of Billroth II gastrectomy.

Background Little information is available about the relationship between restoration of common bile duct (CBD) diameter after endoscopic stone retraction and recurrence of CBD stones in elderly patients. The present study was to determine whether restoration of CBD diameter is a preventive factor for CBD stone recurrence in elderly patients who underwent endoscopic retrograde cholangiopancreatography (ERCP). Methods From January 2006 to December 2010, 238 patients underwent the first and the second session of ERCP for the removal of CBD stones. Among them, 173 were over 65 years old. These patients were divided into recurrent group and non-recurrent group. Restoration of CBD diameter and patients’ characteristics were compared. Results There was no statistical difference in patients’ characteristics, associated diseases, or ERCP-related complications between the two groups. Reduction of CBD diameter was significantly larger in the non-recurrent group (2.7 ± 1.7 mm) compared to that in the recurrent group (1.4 ± 2.3 mm, P = 0.002). The proportion of patients with restoration of CBD diameter were significantly lower in the recurrent group (6/42, 14.3%) compared with that in the non-recurrent group (67/131, 51.1%) (P Conclusions There is an inverse relationship between restoration of CBD diameter and CBD stone recurrence. Therefore, patients without restoration of CBD diameter within 2 weeks after endoscopic stone removal should be monitored more frequently.

Common bile duct (CBD) stone is a relatively frequent disorder with a prevalence of 10-20% in patients with gallstones. This is also associated with serious complications, including obstructive jaundice, acute suppurative cholangitis, and acute pancreatitis. Early diagnosis and prompt treatment is the most important for managing CBD stones. According to a recent meta-analysis, endoscopic ultrasonography and magnetic resonance cholangiopancreatography have high sensitivity, specificity, and accuracy for the diagnosis of CBD stones. Endoscopic ultrasonography, in particular, has been reported to have higher sensitivity between them. A suggested management algorithm for patients with symptomatic gallstones is based on whether they are at low, intermediate, or high probability of CBD stones. Single-stage laparoscopic CBD exploration and cholecystectomy is superior to endoscopic retrograde cholangiopancreatography (ERCP) plus laparoscopic cholecystectomy with respect to technical success and shorter hospital stay in high risk patients with gallstones and CBD stones, where expertise, operative time, and instruments are available. ERCP plus laparoscopic cholecystectomy is usually performed to treat patients with CBD stones and gallstones in many institutions. Patients at intermediate probability of CBD stones after initial evaluation benefit from additional biliary imaging. Patients with a low probability of CBD stones should undergo cholecystectomy without further evaluation. Endoscopic sphincterotomy and endoscopic papillary balloon dilation in ERCP are the primary methods for dilating the papilla of Vater for endoscopic removal of CBD stones. Endoscopic papillary large balloon dilation is now increasingly performed due to the usefulness in the management of giant or difficult CBD stones. Scheduled repeated ERCP may be considered in patients with high risk of recurrent CBD stones.

Anorectal variceal bleeding is a rare occurrence; however, in such event, it could be fatal due to large size and high blood flow rate of varices. However, to date, there is no standardized treatment modality. Although endoscopic treatment can be provided, in cases of recurrent anorectal variceal bleeding, other therapeutic modalities for hemostasis are necessary. Here, we present a case of 58-year-old female patient with liver cirrhosis, who suffered from massive bleeding of anorectal varices. Endoscopic variceal band ligation was performed for primary hemostasis. Additionally, transjugular intrahepatic portosystemic shunt (TIPS) with embolization was performed to reduce the risk of rebleeding. Following the procedure, she had no further bleeding episodes, and the size of anorectal varices decreased, as seen on an abdomino-pelvic computed tomography. Our case illustrates the effectiveness of combined radiological intervention of TIPS with embolization after endoscopic hemostasis, for variceal obliteration and prevention of rebleeding.

In this paper, a design technique of random access preamble (RAP) for high-velocity users (HVUs) in millimeter-wave (mmWave) cellular networks is proposed. After demonstrating the inefficiency of the conventional long-term evolution (LTE)-based RAP for HVUs in mmWave networks, linear-frequency-modulation-based RAP (LFM RAP) is proposed for the detection of HVUs. The correlation of LTE-based RAP, and ambiguity and extended-ambiguity functions of LFM RAP are analyzed to examine their properties affected by the high-velocity of the user. The performance of RAPs is evaluated through detection and false alarm probabilities in a high-velocity and multiuser environment. The results show that the LFM RAP is appropriate for HVUs in mmWave cellular networks because of its high-detection probability in a high-speed environment.

Background Transdiaphragmatic extension of pyogenic liver abscess is the rarest cause of pericarditis and pleural empyema. It is a rapidly progressive and highly lethal infection with mortality rates reaching 100% if left untreated. However, the transmission route, treatment methods and prognosis have not been well studied. Case presentation A 65-year-old male patient presented with a fever, dyspnea, and right upper quadrant abdominal pain. Computed tomography of the chest and abdomen showed huge liver abscess without full liquefaction in the left lobe, large amount of left pleural effusion, and mild pericardial effusion, and the patient was treated with parenteral antibiotics and pigtail insertion at the left pleura. However, four days later, cardiac tamponade was developed and surgical drainage of the abscess and pericardium was performed. Klebsiella pneumonia was isolated from pleural empyema. Twenty-five days after surgery, the patient was discharged without any complications. Conclusions Herein, we report a rare case of pleural empyema and pericarditis in that resulted from the extension of huge pyogenic liver abscess. Early surgical treatment may have prevented progression of the pericarditis to the more dismal purulent pericarditis. We also review pertinent English literature on pericarditis as a complication of PLA.

Future fifth-generation (5G) New Radio (NR) services consider positioning an integral part of a system that provides high precision using millimeter-wave (mmWave) cellular networks. While the 5G standard for positioning is not fully defined yet, the positioning reference signal (PRS) used in long-term evolution (LTE) system is being considered. Since the conventional LTE PRS is designed for LTE systems below 6 GHz, it is more sensitive and inefficient for high-speed vehicle (HSV) experiencing a high Doppler effect in mmWave cellular systems. In this paper, a new sequence, called an oscillatory pulse sequence (OPS), is proposed for the positioning of HSVs in mmWave cellular systems. The ambiguity function (AF) and cross-ambiguity function of OPS are analyzed to examine its autocorrelation and cross-correlation properties in the existence of Doppler shift. The performance of the proposed OPS is compared with the performance of LTE PRS, Zadoff-Chu, and linear-frequency modulated waveforms with respect to correlation, time ambiguity, and Doppler tolerance. The analytic and simulation results show that the OPS provides an accurate timing (distance) estimation in the existence of a high Doppler shift, which is the ideal characteristic of the AF for positioning. The OPS is especially suitable for orthogonal frequency division multiplexing (OFDM) systems because it can be easily multiplexed with other signals in the frequency domain.

Pancreatic pseudocyst is a common complication of acute pancreatitis. Pseudocysts are commonly observed in the lesser sac and retroperitoneum; they are rarely seen in the liver. Herein, we report a case of intrahepatic pseudocyst, complicated by asymptomatic groove pancreatitis, that has successfully been treated with hepatic resection. A 70-year-old woman was referred to our hospital with severe upper abdominal pain. Abdominal computed tomography scan showed 11x10 cm sized cystic lesion in the left lateral section of the liver. Appearance of the pancreas was relatively normal. Endoscopic aspiration revealed a high level of amylase in the cystic fluid. After endoscopy, signs of peritonitis were observed; then, a left hemihepatectomy was performed. Pathologic examination revealed an intrahepatic pancreatic pseudocyst. The presence of intrahepatic cystic lesion in patients with suspected pancreatitis should raise the suspicion of intrahepatic pseudocyst. Intrahepatic pancreatic pseudocysts may be the only clinical manifestation even without an episode of acute pancreatitis.

Rationale Endoscopic ultrasonography-guided tissue acquisition (EUS-TA) has become the norm for the diagnosis of pancreatic solid lesions. EUS-TA is relatively safe, but various complications can occur. Infected pancreatic necrosis (IPN) is a rare but serious complication. The latest guidelines suggest that all invasive interventions in patients with IPN should be delayed until walled-off necrosis appears. Patient concerns A 73-year-old man was referred to our hospital with double primary cancers including gallbladder and pancreas. We performed EUS-TA on metastatic pancreatic tail cancer to confirm histologic diagnosis. Six days after the procedure, he developed abdominal pain and fever. Diagnoses The patient's laboratory findings showed leukocytosis and C-reactive protein elevation. Fluid collection around pancreas tail and stomach was detected in computed tomography (CT) scan, and the patient was diagnosed with IPN. Interventions and outcomes EUS-guided endoscopic transmural drainage (EUS-TD) was performed for the treatment of IPN. Two days after the procedure with antibiotics, his CRP level decreased abruptly, and he received chemotherapy for the treatment of pancreatic ductal adenocarcinoma (PDAC) 5 days after the procedure. He was discharged from our hospital without complications 15 days after chemotherapy. Lessons In selected patients with PDAC, early endoscopic drainage may be recommended as treatment for IPN resulting from complications of EUS-TA.

A small-cell network SCN constructed by splitting a macro-cell into numerous small cells using an active antenna array system is studied. A synchronization signal appropriate for the SCN, virtually generated by an eNodeB with 3D beamforming, is proposed for efficient handover in SCNs. The virtual cell synchronization signal VCSS carries a macro-cell ID MCID and virtual-cell ID VCID in a hierarchical manner, allowing us to distinguish between an intra-cell handover virtual cell handover within a cell without changing the serving eNodeB and inter-cell handover virtual cell handovers across cells while changing the serving eNodeB in SCNs. Using the signal metrics obtained by the VCSS, an efficient handover measurement technique is proposed which can significantly reduce the processing time and overhead by distinguishing between the intra-cell/inter-cell handovers. The performance of the proposed technique is evaluated by simulating two different deployment scenarios of LTE-based SCN with 3D beamforming. Copyright © 2017 John Wiley & Sons, Ltd.

Several studies have demonstrated a correlation between the expression of early growth response gene-1 (EGR-1) and the progression of gastric cancers at advanced stages. However, the effects of EGR-1 expression on human gastric cancer progression, particularly on precancerous lesions, have not been investigated. In this study, we evaluate EGR-1 expression levels in target mucosa from patients with early gastric cancer and precancerous lesions, and assess whether EGR-1 expression affects the oncogenic phenotypes of human gastric cancer cells. EGR-1 protein levels were measured in tissues from subjects with normal mucosa (n=6), low-grade dysplasia (n=6), high-grade dysplasia (n=4) and adenocarcinoma (n=3) using enzyme-linked immunosorbent assay and immunohistochemistry analyses. We also investigated the role of EGR-1 in tumor cell behavior by transiently expressing a dominant active EGR-1 variant in cultured cells. A positive correlation was observed between EGR-1 expression and gastric carcinogenesis (P=0.016). Furthermore, there was an increase in nuclear and cytoplasmic expression of EGR-1 in accordance with the histological grade (P for trends=0.003 and 0.003, respectively), and a positive association between the sum of the nuclear and cytoplasmic EGR-1 expression values and the histological grade (P=0.003). In addition, transient overexpression of EGR-1 enhanced cell proliferation, stimulated cell migration, and promoted the phosphorylation of p38 MAPK and AKT in gastric cancer cells in vitro. Our findings demonstrate that EGR-1 may contribute to the early stages of gastric carcinogenesis via the alteration of tumor cell behaviors.

Background/Aims: Endoscopic retrograde biliary drainage (ERBD) has become a standard procedure in patients with a biliary obstruction. Intraductal ultrasonography (IDUS) has emerged as a new tool for managing extrahepatic biliary diseases. IDUS-directed ERBD can be performed without conventional cholangiography (CC). The goal of this study was to assess the effectiveness and safety of IDUS-directed ERBD compared to CC-directed ERBD in patients with an extrahepatic biliary obstruction. Methods: A total of 210 patients who had undergone IDUS-directed ERBD (IDUS-ERBD, n = 105) and CC-directed ERBD (CC-ERBD, n = 105) between October 2013 and April 2014 were analyzed retrospectively. The primary outcome measure was the procedural success rate. Secondary outcome measures included clinical outcomes, total procedure time, radiation exposure time, and overall complication rates. Results: The total technical success rate of ERBD was 100% (105/105) in the IDUS-ERBD and CC-ERBD groups. Mean procedure time was slightly prolonged in the IDUS-ERBD group than that in the CC-ERBD group (32.1 ± 9.9 minutes vs. 28.4 ± 11.6 minutes, p = 0.023). Mean radiation exposure time was one-third less in the IDUS-ERBD group than that in the CC-ERBD group (28.0 ± 49.3 seconds vs. 94.2 ± 57.3 seconds, p < 0.001). No significant differences in complication rates were detected between the groups. Conclusions: IDUS-ERBD was equally effective and safe as CC-ERBD in patients with an extrahepatic biliary obstruction. Although IDUS-ERBD increased total procedure time, it significantly decreased radiation exposure.

Transdiaphragmatic extension of pyogenic liver abscess is the rarest cause of pericarditis and pleural empyema. It is a rapidly progressive and highly lethal infection with mortality rates reaching 100% if left untreated. However, the transmission route, treatment methods and prognosis have not been well studied.A 65-year-old male patient presented with a fever, dyspnea, and right upper quadrant abdominal pain. Computed tomography of the chest and abdomen showed huge liver abscess without full liquefaction in the left lobe, large amount of left pleural effusion, and mild pericardial effusion, and the patient was treated with parenteral antibiotics and pigtail insertion at the left pleura. However, four days later, cardiac tamponade was developed and surgical drainage of the abscess and pericardium was performed. Klebsiella pneumonia was isolated from pleural empyema. Twenty-five days after surgery, the patient was discharged without any complications.Herein, we report a rare case of pleural empyema and pericarditis in that resulted from the extension of huge pyogenic liver abscess. Early surgical treatment may have prevented progression of the pericarditis to the more dismal purulent pericarditis. We also review pertinent English literature on pericarditis as a complication of PLA.

Background Eradication rate for Helicobacter pylori (H. pylori) has decreased due to antibiotic resistance. Therefore, new strategies are needed to enhance H. pylori eradication, especially for H. pylori with high antibiotic resistance. The objective of this study was to evaluate anti-H. pylori activities of constituents from key lime (Citrus aurantifolia) and their possible inhibitory effects on urease activity of H. pylori. Methods Helicobacter pylori strain ATCC 43526 and triple drug resistant (TDR) H. pylori strains were used in this study. Urease activities of H. pylori strains were measured by ammonia colorimetrical quantification using ELISA reader. Minimum inhibitory concentrations were determined by agar dilution method for antibiotics and by modified media dilution method for each constituent of Citrus aurantifolia (C. aurantifolia). Results Citrus aurantifolia extract decreased the number of colonies of H. pylori strain ATCC 43526 and TDR H. pylori stains. An increasing concentration of C. aurantifolia extract attenuated urease activities of H. pylori strain ATCC 43526 and TDR H. pylori strains. Among constituents of C. aurantifolia, citral and 4-hexen-3-one were found to be able to inhibit the growth of H. pylori strain ATCC 43526 and TDR H. pylori strains. Furthermore, citral and 4-hexen-3-one inhibited urease activities of H. pylori strain ATCC 43526 and TDR H. pylori strains in a dose-dependent manner. Conclusion Citrus aurantifolia has antimicrobial effect on TDR H. pylori strains, suggesting that C. aurantifolia might have therapeutic potential to control antibiotic-resistant H. pylori strains that cause eradication failure using other antibiotics.

BACKGROUND/AIMS: Colon transit time (CTT) is a useful diagnostic tool in chronic constipation, but requires good patient compliance. We analyzed the correlation between the gas volume score (GVS) and CTT in patients with chronic constipation. METHODS: The study included 145 consecutive patients (65 men) with chronic constipation. The primary outcome was the correlation be-tween the colon GVS and CTT. Secondary outcomes were the differences in colon GVS according to CTT and subtypes of chronic constipation. RESULTS: There were 81 patients with "CTT < 45 hours" and 64 patients with "CTT ≥ 45 hours." In addition, 88 patients were classi-fied as having functional constipation and 57 were classified as having constipation predominant irritable bowel syndrome (IBS-C). There was no significant correlation between CTT and colon GVS. However, the right colon GVS showed a positive cor-relation with right CTT (r = 0.255, P = 0.007). The median total colon GVS was significantly higher in patients with "CTT ≥ 45 hours" than in those with "CTT < 45 hours" (5.65% vs 4.15%, P = 0.010). There were no significant differences in colon GVS between the functional constipation and IBS-C. CONCLUSIONS: We were unable to detect a correlation between GVS and CTT in patients with chronic constipation. However, total colon GVS may be a method of predicting slow transit in patients with chronic constipation.

In this paper, the effect of time difference of arrival (TDoA) is investigated for distributed nodes in OFDMA-based wireless mesh networks (WMNs). In order to minimize the interferences caused by TDoA in WMNs, the optimal starting point of FFT window at the receiver side of a node is derived by maximizing the effective SINR for each subcarrier. Also, a signal detection technique, called two dimensional ordered successive interference cancellation (TD-OSIC), is proposed for WMNs with TDoAs. It was shown via simulation that the proposed technique can achieve effective SINR and BER performances similar to the ideal case (no TDoA), even in WMNs with large TDoAs.

In this study, the authors propose a signal detection technique of successive interference cancellation to reduce the effect of inter-symbol interference (ISI), which is caused by the time difference of arrivals among distributed nodes in an asynchronous wireless mesh network based on filtered multi-tone modulation. The proposed signal detection technique uses partial matrices of a transmission gain matrix to mitigate the ISI effect from the adjacent symbols. Under the assumption of perfect symbol time offset and channel estimation at each node, it is shown by simulation that the proposed technique can improve the bit error rate performance with lower complexity compared with the conventional technique.

BACKGROUND/AIMS Endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging in patients with altered gastrointestinal (GI) anatomy. We evaluated the feasibility of cap-assisted ERCP in patients with altered GI anatomy. METHODS The outcome of ERCP procedures (n=136) was analyzed in 78 patients with Billroth II (B-II) gastrectomy (n=72), Roux-en-Y total gastrectomy (n=4), and hepaticoduodenostomy (n=2). The intubation rate for reaching the papilla of Vater (POV), deep biliary cannulation rate, therapeutic interventions and procedure-related complications were analyzed. All of the procedures were conducted using a cap-fitted forward-viewing endoscope. RESULTS The rate of access to the POV was 97.1% (132/136). In cases with successful access, selective biliary cannulation was achieved in 98.5% (130/132) of the patients. The successful biliary cannulation rates were 100% (125/125) for B-II gastrectomy, 50% (2/4) for Roux-en-Y gastrectomy and 100% (3/3) for hepaticoduodenostomy. After selective biliary cannulation, therapeutic interventions, including stone extraction (n=57), sphincterotomy (n=54), stent placement (n=37), nasobiliary drainage (n=20), endoscopic papillary balloon dilatation (n=7) and mechanical lithotripsy (n=15), were performed successfully. The procedure-related complication rate was 8.8% (12/136), including immediate bleeding (5.9%, 8/136), pancreatitis (2.2%, 3/136), and perforation (0.7%, 1/136). There were no procedure-related deaths. CONCLUSIONS Cap-assisted ERCP is efficient and safe in patients with altered GI anatomy.

BACKGROUND/AIMS To evaluate the long-term efficacy and safety of endoscopic injection of N-butyl-2-cyanoacrylate (NBC; Histoacryl) for treatment of bleeding gastric varices. METHODS We retrospectively analyzed the records of 455 patients with gastric variceal hemorrhage (GVH) who were consecutively treated with NBC from January 2004 to July 2013, with a mean follow-up period of 582 days. The patients' endoscopic findings, initial hemostasis, complications, rebleeding rates, and bleeding-related death rates were reviewed. RESULTS Hemostasis was achieved initially in 96.9% (441/455) of patients; rebleeding occurred in 35.2% (160/455), and the bleeding-related death rate was 6.8% (31/455) during follow-up. Complications included fever (6.8%), abdominal pain (3.7%), diarrhea (1.3%), spontaneous bacterial peritonitis (0.7%), bacteremia (0.4%), and embolism (0.2%). A red-color sign on concomitant esophageal varices (EVs) (p = 0.002) and previous history of variceal bleeding (p < 0.001) were significant risk factors for rebleeding within 1 year. The Child-Pugh score (p < 0.001), presence of hepatocellular carcinoma (p = 0.001), and failure of initial hemostasis (p < 0.001) were the risk factors most closely associated with bleeding-related death. CONCLUSIONS This study provides a comprehensive overview of the outcomes and prognostic factors of patients with GVH. The results may help in the selection of effective treatment strategies for patients with GVH.

Gastrointestinal xanthomas are characterized by foamy cytoplasmic cells containing lipid in lamina propria, and occur almost in the gastric mucosa. Colonic xanthomas have been described in rare case. All reported colonic xanthomas were located in rectosigmoid. Rectosigmoid xanthomas have tended to exhibit small polypoid lesion, on the contrary flat in stomach. We report a case of xanthoma on ascending colon presenting as a laterally spreading tumor resected by endoscopic mucosal resection method.

Purpose To evaluate the risk factors of hepatocellular carcinoma (HCC) extension into the right atrium (RA) and determine poor prognostic factors for HCC extension to the heart. Materials and Methods A total of 665 patients who were newly diagnosed with HCC were analyzed retrospectively from January 2004 to July 2012. The patients were divided into two groups: 33 patients with HCC extending into the RA and 632 HCC patients during the same period. The patients with HCC extending into the RA were subdivided into shorter survival group (3 (p=0.016, OR: 13.89) and active treatment (p=0.024, OR: 0.054) were associated with prognostic factors in patients HCC extending into the RA. Active treatment such as radiation (n=1), transcatheter arterial chemoembolization (TACE) (n=11), Sorafenib (n=1), and combined modalities (n=2) were performed. Conclusion Modified UICC stage higher than IVA, vascular invasion and multinodular tumor type are independent risk factors for HCC extending to the RA. Active treatment may prolong survival in patients HCC extending into the RA.

Capsaicin is known to have tumor suppressive effects. However, the molecular mechanisms and targets of capsaicin involved in exerting anticancer activity are complex and remain to be clarified. The aim of the current study was to investigate the effects of capsaicin on human gastric cancer cells (AGS cells) and demonstrate that capsaicin induced apoptosis in AGS cells. Results of the MTT assay and flow cytometry revealed that capsaicin potentially inhibited the proliferation of AGS cells and induced apoptosis in vitro in a dose-dependent manner. Cleaved caspase-3 was increased and Bcl-2 was reduced by treatment with capsaicin in AGS cells. Capsaicin treatment decreased the expression of phosphorylated ERK 1/2, p38 MAPK or JNK in AGS cells. The results of this study suggest that capsaicin may serve as an anti-tumorigenic agent in human gastric cancer.

We report the first case of hypercalcemia-induced acute pancreatitis caused by a functioning parathyroid cyst in a 67-year-old man. Laboratory investigation revealed increased serum amylase and lipase, increased serum ionized calcium and parathyroid hormone (PTH) levels, and decreased serum phosphate, indicating pancreatitis and primary hyperparathyroidism (PHPT). Abdominal computed tomography (CT) revealed mild swelling of the pancreatic head with peri-pancreatic fat infiltration and fluid collection around the pancreatic tail. Ultrasonography and CT of the neck showed a cystic lesion at the inferior portion of the left thyroid gland, suggesting a parathyroid cyst. There was no evidence of parathyroid adenoma by 99mTc sestamibi scintigraphy. PHPT caused by a functioning parathyroid cyst was suspected. The patient underwent surgical resection of the functioning parathyroid cyst owing to his prolonged hypercalcemia. At 3 weeks after the operation, his serum levels of PTH, total calcium, ionized calcium, inorganic phosphate, amylase, and lipase were normalized. At the follow-up examinations, he has remained asymptomatic.

Duodenal neuroendocrine tumors (NETs) are rare neoplasms. In this study, the medical records of 14 patients with duodenal NETs diagnosed at Chonnam National University Hospital from July 2001 to August 2011 were reviewed and analyzed retrospectively. Four patients were diagnosed in the first 5 years, and 10 patients were diagnosed in the latter 5 years of the study. Ten of 12 patients (83.3%) who underwent endoscopic biopsy were confirmed to have NET before resection. Endoscopic resection was performed in 12 patients, surgical resection in one patient, and regular follow-up in one patient who refused resection. None of the patients showed recurrence or distant metastasis. Duodenal NETs are increasingly observed and are mostly detected during screening upper gastrointestinal endoscopy. Careful endoscopic examination and biopsy can improve the diagnostic yield of NETs. Most well-differentiated, nonfunctional duodenal NETs that are limited to the mucosa/submucosa can be treated effectively with endoscopic resection.

The aim of this study was to compare the efficacy, rebleeding rates, survival, and complications of endoscopic variceal ligation (EVL) with those of endoscopic variceal obliteration (EVO) in patients with acute type 1 gastroesophageal variceal (GOV1) bleeding. Data were collected retrospectively at a single center. A total of 84 patients were selected (20 patients underwent EVL; 64 patients underwent EVO) from February 2004 to September 2011. Their clinical characteristics, laboratory results, vital signs, Child-Pugh score, Model for End-stage Liver Disease (MELD) score, and overall mortality were evaluated. There were no significant differences in baseline characteristics between the two groups. The success rate in initial control of active bleeding was not significantly different between the EVL and EVO groups (18/20 EVL, or 90.0%, compared with 62/64 EVO, or 96.9%; p=0.239). The early rebleeding rate was also not significantly different between the groups (3/18 EVL, or 16.7% compared with 17/62 EVO, or 27.4%; p=0.422). The late rebleeding rate of the EVL group was lower than that of the EVO group (3/18 EVL, or 16.7%, compared with 26/59 EVO, or 44.1%; p=0.042). The time-to-rebleeding was 594 days for the EVL group and 326 days for the EVO group (p=0.054). In the multivariate analysis, portal vein thrombosis (PVT) was a significant risk factor for early rebleeding. Hepatocellular carcinoma (HCC) and previous history of bleeding were significant risk factors for very late rebleeding. In conclusion, EVL is better than EVO in reducing late rebleeding in acute GOV1 bleeding. HCC, PVT, and previous bleeding history were significant risk factors for rebleeding.

Endoscopic retrograde cholangiopancreatography (ERCP) in post-gastrectomy patients with Billroth II (BII) reconstruction and Roux-en-Y (RY) reconstruction presents a challenge to therapeutic endoscopists. Major difficulties, including intubation to the ampulla of Vater, selective cannulation, and ampullary intervention, must be overcome in these patients. Recent data have shown that device-assisted ERCP allows for high success rates in these patients because various devices are useful for overcoming major difficulties. Therefore, good knowledge of postoperative anatomy and various devices is mandatory before performing ERCP procedures for post-gastrectomy patients.

The significant growth of machine-to-machine applications for low-power cellular Internet of Things has compelled 3rd Generation Partnership Project to ensure that the future release of long-term evolution can support massive transfer of small, infrequent packets using ultra-low-power and low-cost devices. The 3rd Generation Partnership Project version of machine-to-machine, called “machine-type communication,” is currently being standardized for low-cost machine-type communication operations. In this article, a complete synchronization and cell search procedure is described for machine-type communication devices in long-term evolution systems. Low-complexity algorithms for primary synchronization signal and secondary synchronization signal detection, which requires the highest computational complexity in synchronization and cell search period, are also proposed for low-power machine-type communication devices. Through simulation under long-term evolution-based machine-type communication environments, we show that the proposed methods for primary synchronization signal and secondary synchronization signal detection require six and five times less computational complexity than the conventional methods, respectively, while their performance is similar. The proposed algorithms allow machine-type communication devices in a discontinuous reception cycle to resynchronize quickly with less power when synchronization is lost during a deep sleep period.

Intraductal ultrasonography (IDUS) is one of the most useful diagnostic tools for various extrahepatic biliary diseases. However, conventional IDUS has some limitations in providing accurate cross-sectional imaging of the bile duct in patients with extensive pneumobilia. Using a balloon-sheathed catheter, the US system (balloon-sheathed IDUS) can overcome these limitations. Sixteen patients underwent balloon-sheathed IDUS during endoscopic retrograde cholangiography. The balloon-sheathed IDUS was inserted via a transpapillary route when visualization of the bile duct with conventional IDUS was distorted by extensive pneumobilia. The patient group had a mean age of 65.5 years, and 56.3% (9/16) were male. The balloon-sheathed IDUS permitted successful visualization of the bile duct in all patients, regardless of the extent of pneumobilia. Using this system, remnant common bile duct stones were detected in five patients (31.3%), and cholangiocarcinoma was detected in one patient (6.3%). The balloon-sheath IDUS aided in stone sweeping. No significant complications, including bleeding, perforation, or pancreatitis, occurred in any of the patients. The balloon-sheathed catheter US system was useful and safe for biliary IDUS in patients with extensive pneumobilia.

Background/Aims Percutaneous coronary intervention (PCI) is often performed therapeutically, and antithrombotic treatment is required for at least 12 months after stent implantation. However, the development of post-PCI upper gastrointestinal bleeding (UGIB) increases morbidity and mortality. We investigated the incidence and risk factors for UGIB in Korean patients within 1 year after PCI. Methods The medical records of 3,541 patients who had undergone PCI between January 2006 and June 2012 were retrospectively reviewed. We identified 40 cases of UGIB. We analyzed the incidence and clinical risk factors associated with UGIB occurring within 1 year after PCI by comparing the results for each case to matched controls. The propensity score matching method using age and sex was utilized. Results UGIB occurred in 40 patients (1.1%). Two independent risk factors for UGIB were a history of peptic ulcer disease (odds ratio [OR], 12.68; 95% confidence interval [CI], 2.70 to 59.66; p=0.001) and the use of anticoagulants (OR, 7.76; 95% CI, 2.10 to 28.66; p=0.002). Conclusions UGIB after PCI occurred at a rate of 1.1% in the study population. Clinicians must remain vigilant for the possibility of UGIB after PCI and should consider performing timely endoscopy in patients who have undergone PCI and are suspected of having an UGIB.

BACKGROUND/AIMS: Dieulafoy lesions (DLs) are a rare but significant cause of upper gastrointestinal bleeding. We aimed to define the clinical significance of rebleeding and identify the predictors of rebleeding and mortality in upper gastrointestinal Dieulafoy lesions (UGIDLs). METHODS: Patients diagnosed with UGIDLs between January 2004 and June 2013 were retrospectively evaluated. Multivariate logistic regression analyses were performed to define the predictors of rebleeding and mortality in patients with UGIDLs. RESULTS: The study group consisted of 81 male and 36 female patients. Primary hemostasis was achieved in 115 out of 117 patients (98.3%) with various endoscopic therapies. Rebleeding occurred in 10 patients (8.5%). The mortality rate was significantly higher in patients with rebleeding than in those without rebleeding (30.0% vs. 4.7%, p=0.020). Multivariate logistic regression analysis revealed that kidney disease (p=0.006) and infection (p=0.005) were significant predictors of rebleeding in UGIDLs and that kidney disease (p=0.004) and platelet count (p=0.013) were significant predictors of mortality. CONCLUSIONS: Rebleeding has an important prognostic significance in patients with UGIDLs. Kidney disease and infection are major predictors of rebleeding and mortality in patients with UGIDLs.

Background/Aims: To evaluate the efficacy of proton pump inhibitors (PPIs) in reducing rebleeding and bleeding-related death rates after endoscopic gastric variceal obliteration (GVO) using N-butyl-2-cyanoacrylate (NBC). Methods: This study enrolled 341 patients who were consecutively diagnosed with and treated for bleeding gastric varices. The patients were divided into PPI and non-PPI groups, and their endoscopic findings, initial hemostasis outcomes, rebleeding and bleeding-related death rates, and treatment-related complications were analyzed. Results: The rate of initial hemostasis was 97.1%. rebleeding occurred in 2.2% of patients within 2 weeks, 3.9% of patients within 4 weeks, 18.9% of patients within 6 months, and 27.6% of patients within 12 months of the GVO procedure. A previous history of variceal bleeding (relative risk [RR], 1.955; 95% confidence interval [CI], 1.263 to 3.028; p = 0.003) and use of PPIs (RR, 0.554; 95% CI, 0.352 to 0.873; p = 0.011) were associated with rebleeding. Child-Pugh class C (RR, 10.914; 95% CI, 4.032 to 29.541; p < 0.001), failure of initial hemostasis (RR, 13.329; 95% CI, 2.795 to 63.556; p = 0.001), and the presence of red-colored concomitant esophageal varices (RR, 4.096; 95% CI, 1.320 to 12.713; p = 0.015) were associated with bleeding-related death. Conclusions: The prophylactic use of PPIs reduces rebleeding after GVO using NBC in patients with gastric variceal hemorrhage. However, prophylactic use of PPIs does not reduce bleeding-related death.

Background/Aims Synchronous/metachronous gastric epithelial neoplasias (GENs) in the remaining lesion can develop at sites other than the site of endoscopic resection. In the present study, we aimed to investigate the predictive value of serum pepsinogen for detecting multiple GENs in patients who underwent endoscopic resection. Methods In total, 228 patients with GEN who underwent endoscopic resection and blood collection for pepsinogen I and II determination were evaluated retrospectively. Results The mean period of endoscopic follow-up was 748.8±34.7 days. Synchronous GENs developed in 46 of 228 (20.1%) and metachronous GENs in 27 of 228 (10.6%) patients during the follow-up period. Multiple GENs were associated with the presence of pepsinogen I