80 research outputs found

    Programmable time-multiplexed squeezed light source

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    One of the leading approaches to large-scale quantum information processing (QIP) is the continuous-variable (CV) scheme based on time multiplexing (TM). As a fundamental building block for this approach, quantum light sources to sequentially produce time-multiplexed squeezed-light pulses are required; however, conventional CV TM experiments have used fixed light sources that can only output the squeezed pulses with the same squeezing levels and phases. We here demonstrate a programmable time-multiplexed squeezed light source that can generate sequential squeezed pulses with various squeezing levels and phases at a time interval below 100 ns. The generation pattern can be arbitrarily chosen by software without changing its hardware configuration. This is enabled by using a waveguide optical parametric amplifier and modulating its continuous pump light. Our light source will implement various large-scale CV QIP tasks.Comment: 14 pages, 7 figure

    Contrast-enhanced harmonic endoscopic ultrasound using time–intensity curve analysis predicts pathological grade of pancreatic neuroendocrine neoplasm

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    PURPOSE: Histological grading is important for the treatment algorithm in pancreatic neuroendocrine neoplasms (PNEN). The present study examined the efficacy of contrast-enhanced harmonic endoscopic ultrasound (CH-EUS) and time-intensity curve (TIC) analysis of PNEN diagnosis and grading. METHODS: TIC analysis was performed in 30 patients using data obtained from CH-EUS, and a histopathological diagnosis was made via EUS-guided fine-needle aspiration or surgical resection. The TIC parameters were analyzed by dividing them into G1/G2 and G3/NEC groups. Then, patients were classified into non-aggressive and aggressive groups and evaluated. RESULTS: Twenty-six patients were classified as G1/G2, and four as G3/NEC. From the TIC analysis, five parameters were obtained (I: echo intensity change, II: time for peak enhancement, III: speed of contrast, IV: decrease rate for enhancement, and V: enhancement ratio for node/pancreatic parenchyma). Three of these parameters (I, IV, and V) showed high diagnostic performance. Using the cutoff value obtained from the receiver-operating characteristic (ROC) analysis, the correct diagnostic rates of parameters I, IV, and V were 96.7%, 100%, and 100%, respectively, between G1/G2 and G3/NEC. A total of 21 patients were classified into the non-aggressive group, and nine into the aggressive group. Using the cutoff value obtained from the ROC analysis, the accurate diagnostic rates of I, IV, and V were 86.7%, 86.7%, and 88.5%, respectively, between the non-aggressive and aggressive groups. CONCLUSION: CH-EUS and TIC analysis showed high diagnostic accuracy for grade diagnosis of PNEN. Quantitative perfusion analysis is useful to predict PNEN grade diagnosis preoperatively

    For Vol.70, No.5 pp405-408 A Multicenter, Prospective, Randomized Controlled Trial Evaluating the Efficacy of Rectal Diclofenac and Sublingual Nitrate as a Combined Prophylactic Treatment for Post-ERCP Pancreatitis

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    In the article by Tomoda T et al. entitled “A Multicenter, Prospective, Randomized Controlled Trial Evaluating the Efficacy of Rectal Diclofenac and Sublingual Nitroglycerin as a Combined Prophylactic Treatment for Post-ERCP Pancreatitis”, which appeared in the October 2016 issue, Vol. 70, No. 5, pp405-408, the word “nitroglycerin” should be corrected to “nitrate” throughout the manuscript

    Endoscopic ultrasonography findings of pancreatic parenchyma for predicting subtypes of intraductal papillary mucinous neoplasms

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    Background and Aims: The subtypes of intraductal papillary mucinous neoplasms (IPMNs) are closely associated with the clinicopathological behavior and recurrence after surgical resection. However, there are no established non-invasive methods to confirm the subtypes of IPMNs without surgery. The aim of this study is to predict the subtypes of IPMNs using the findings of endoscopic ultrasonography (EUS). Methods: Sixty-two consecutive patients with IPMNs who underwent EUS before surgery were retrospectively reviewed. The following EUS findings were analyzed and their relationship with the subtypes was evaluated: diameter of the main pancreatic duct, cyst size, number of cysts, height of mural nodule, early chronic pancreatitis (CP) finding, fatty parenchyma and atrophic parenchyma. Results: The subtypes of IPMNs were as follows: gastric (G)-type 38 (61%), intestinal (I) -type 14 (23%) and pancreatobiliary (PB) -type 10 (16%). Fatty parenchyma was significantly associated with G-type (P Conclusions: The evaluation of EUS findings, especially focused on the pancreatic parenchyma, has the potential to predict the subtypes of IPMN

    Utility of Endoscopic Ultrasound-Guided Fine Needle Aspiration in the Diagnosis of Local Recurrence of Pancreaticobiliary Cancer after Surgical Resection

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    Background/Aims: Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA; EUS-FNA) allows for diagnostic tissue specimens from various regions to be analyzed. However, diagnosing recurrent pancreaticobiliary cancer after surgery is sometimes difficult. We evaluated the efficacy of EUS-FNA in the diagnosis of local recurrence of pancreaticobiliary cancer and analyzed the factors associated with falsenegative results. Methods: Fifty-one consecutive patients who underwent EUS-FNA due to suspected recurrence of pancreaticobiliary cancer after surgery in an academic center were retrospectively analyzed. The criteria for EUS-FNA were a resected margin or remnant pancreas mass, round swollen lymph node (≥10 mm in diameter), and soft-tissue enhancement around a major artery. Patients with suspected liver metastasis or malignant ascites were excluded. Results: Thirty-nine of the 51 patients had pancreatic cancer; the remaining 12 had biliary cancer. The target sites for EUS-FNA were the soft tissue around a major artery (n=22, 43%), the resected margin or remnant pancreas (n=12, 24%), and the lymph nodes (n=17, 33%). The median size of the suspected recurrent lesions was 15 mm (range, 8 to 40 mm). The overall sensitivity, specificity and accuracy of EUS-FNA for the diagnosis of recurrence was 84% (32/38), 100% (13/13), and 88% (45/51), respectively. FNA of the soft tissue around major arteries (odds ratio, 8.23; 95% confidence interval, 1.2 to 166.7; p=0.033) was significantly associated with a falsenegative diagnosis in the multivariate analysis. Conclusions: EUS-FNA is useful for diagnosing recurrent cancer, even after pancreaticobiliary surgery. The diagnoses of recurrence at soft-tissue sites should be interpreted with caution

    Outcomes of endoscopic treatment for malignant biliary obstruction in patients with surgically altered anatomy: analysis of risk factors for clinical failure

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    Background To evaluate the outcomes of endoscopic retrograde cholangiopancreatography (ERCP) for malignant biliary obstruction (MBO) using short-type double-balloon enteroscope (sDBE) in patients with surgically altered anatomy. Methods A total of 45 patients with surgically altered anatomy underwent ERCP using sDBE for the treatment of MBO between April 2011 and March 2019. We retrospectively evaluated the clinical and technical success (insertion and biliary intervention success), adverse events, and risk factors for clinical failure. Results The scope was successfully inserted in the target site in 82.2% of patients (37/45), and among them, biliary intervention success was achieved in 86.4% (32/37). The overall technical success rate was 71.1% (32/45) and clinical success rate was 68.9% (31/45), with an adverse event rate of 11.1%. In multivariate analysis, the presence of peritoneal dissemination (odds ratio, 7.3; 95% confidence interval, 1.5–43.5, p = 0.02) was as an independent risk factor for clinical failure. The clinical success rate was 38.5% in patients with peritoneal dissemination and 81.3% in those without peritoneal dissemination. Conclusion Endoscopic treatment using sDBE in patients without peritoneal dissemination provided favorable outcomes, and it can be an initial treatment for MBO in patients with surgically altered anatomy. Endoscopic biliary stent placement with endoscopic retrograde cholangiography (ERCP) for the treatment of malignant biliary obstruction (MBO) has been widely accepted as an effective drainage method because it is less invasive and safe and has a high success rate (1–3). However, MBO is treated using percutaneous transhepatic biliary drainage (PTBD) or surgical bypass because of difficulties related to endoscopic access to the bile duct following gastrointestinal reconstruction. However, these methods are associated with marked adverse event (AE) rates [1,2,3]. Recently, balloon-assisted endoscopy (BAE) facilitates ERCP in patients with surgically altered anatomy. As for a double-balloon enteroscope (DBE), a short-type DBE (sDBE) is especially useful because it allows the use of many standard ERCP accessories. The success rates of reaching the target site and ERCP-related interventions associated using these endoscopes range from 73–100% and 85–100%, respectively [4, 5]. We previously reported that the success rate of reaching the target site and biliary intervention was 93.8% and 95.7%, respectively, in patients with benign hepaticojejunostomy (HJ) anastomotic stricture [6]. However, inaccessibility of the target site may occur due to severe postoperative adhesions or a long insertion time (i.e., > 60 min). Furthermore, previous reports have shown that the success rate of BAE in MBO cases was significantly lower than that in benign biliary diseases [7, 8]. Few reports have investigated the outcome of BAE for MBO in patients with surgically altered anatomy. Additionally, the risk factors for clinical failure are not well-established. Thus, we retrospectively evaluated the outcomes of endoscopic treatment for MBO using sDBE in patients with surgically altered anatomy and identified risk factors for clinical failure

    Combination of Diclofenac and Sublingual Nitrates Is Superior to Diclofenac Alone in Preventing Pancreatitis After Endoscopic Retrograde Cholangiopancreatography

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    BACKGROUND & AIMS: Acute pancreatitis is a major adverse event of endoscopic retrograde cholangiopancreatography (ERCP). Rectal administration of nonsteroidal anti-inflammatory drugs (NSAIDs) decreases the incidence of post-ERCP pancreatitis (PEP). Little is known about the combined effects of sublingual nitrate and NSAIDs. We performed a randomized trial to assess whether the combination of NSAIDs and sublingual nitrate is more effective than NSAIDs alone in preventing PEP. METHODS: In a prospective superiority trial, eligible patients underwent ERCP at 12 endoscopic units in Japan, from March 2015 through May 2018. Patients were randomly assigned to groups given diclofenac suppositories (50 mg) within 15 minutes after the endoscopic procedure alone (diclofenac-alone group, n = 442) or in combination with sublingual isosorbide dinitrate (5 mg) 5 minutes before the endoscopic procedure (combination group, n = 444). The primary endpoint was the occurrence of PEP. RESULTS: PEP developed in 25 patients in the combination group (5.6%), and in 42 patients in the diclofenac-alone group (9.5%) (relative risk 0.59; 95% confidence interval 0.37-0.95; P = .03). Moderate to severe pancreatitis developed in 4 patients (0.9%) in the combination group, and 10 patients (2.3%) in the diclofenac-alone group (relative risk 0.12; 95% confidence interval 0.13-1.26; P = .12). There was no serious adverse event related to the additional administration of sublingual nitrate. CONCLUSIONS: In a randomized controlled trial, we found that prophylaxis with rectal diclofenac and sublingual nitrate significantly reduces the overall incidence of PEP compared with diclofenac suppository alone. ClinicalTrials.gov, no: UMIN 000016274
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