Risk of colonoscopic post-polypectomy bleeding in patients after the discontinuation of antithrombotic therapy.

BACKGROUND/AIMS: Few studies have examined the incidence of post-polypectomy bleeding (PPB) after discontinuation of antithrombotic therapies. Therefore, this study aimed to evaluate the incidence of PPB and thromboembolic events in patients whose antithrombotic agents were discontinued before colonoscopy. MATERIALS AND METHODS: We retrospectively selected all patients who underwent colon polypectomy at a community hospital. A total of 282 patients (540 polypectomies) discontinued antithrombotic agents (group 1), and 1,648 patients (2,827 polypectomies) did not take antithrombotic agents (group 2). The cessation periods before and after polypectomies were 4 and 3 days for warfarin, 5 and 3 days for anti-platelet agents, and 7 and 5 days of combination therapy, respectively. Main outcome measurements were the incidence of PPB and thromboembolic events. RESULTS: Immediate PPB rates were 3.9% (11/282) in group 1 and 4.6% (76/1648) in group 2 (adjusted odds ratio [OR], 0.85; 95% confidence interval [CI], 0.42-1.72; p=0.65). Delayed PPB rates were 1.4% (4/282) in group 1 and 1.1% (18/1648) in group 2 (adjusted OR, 1.24; 95% CI, 0.36-4.24; p=0.732). No thromboembolic events were observed in either group. CONCLUSION: Our cessation periods were appropriate, and further shortening of these periods is possible.

Multicenter prospective study on the histological diagnosis of gastric cancer by narrow band imaging-magnified endoscopy with and without acetic acid.

Background and study aims The usefulness of endoscopy for diagnosing histological type remains unclear. This study aimed to examine the diagnostic accuracy of white light endoscopy (WLE), magnified endoscopy with narrow band imaging (NBI-ME), and NBI-ME with acetic acid enhancement (NBI-AA) for histological type of gastric cancer. Patients and methods Patients with depressed-type gastric cancers resected by endoscopic submucosal dissection were prospectively enrolled, and 221 cases were analyzed. Histological type was diagnosed by WLE, followed by NBI-ME and NBI-AA. Histological type was classified into differentiated adenocarcinoma and undifferentiated adenocarcinoma. Histological type was diagnosed based on lesion color in WLE, surface patterns (pit, villi, and unclear) and vascular irregularities in NBI-ME, and surface patterns in NBI-AA. Results Histological types of target areas were differentiated adenocarcinoma and undifferentiated adenocarcinoma in 206 and 15 cases, respectively. Diagnostic accuracy of WLE, NBI-ME, and NBI-AA for the histological type was 96.4 % (213/221), 96.8 % (214/221), and 95.5 % (211/221), respectively. No significant differences were observed among modalities. Positive predictive value based on endoscopic findings in NBI-ME was 98.0 % (149/152) for the villi pattern, 100 % (19/19) for the irregular pit pattern, 100 % (9/9) for the unclear surface pattern with a vascular network, 90.3 % (28/31) for the unclear surface pattern with mild vascular irregularity, and 88.9 % (8/9) for the unclear surface pattern with severe vascular irregularity. Conclusions NBI-ME and NBI-AA did not show any advantages over WLE for diagnostic accuracy. Villi pattern, irregular pit pattern, and vascular network may be useful for identifying differentiated adenocarcinoma.

Identification and characterization of a translation arrest motif in VemP by systematic mutational analysis.

VemP ( Vibrio protein export monitoring polypeptide) is a secretory protein comprising 159 amino acid residues, which functions as a secretion monitor in Vibrio and regulates expression of the downstream V.secDF2 genes. When VemP export is compromised, its translation specifically undergoes elongation arrest at the position where the Gln156 codon of vemP encounters the P-site in the translating ribosome, resulting in up-regulation of V.SecDF2 production. Although our previous study suggests that many residues in a highly conserved C-terminal 20-residue region of VemP contribute to its elongation arrest, the exact role of each residue remains unclear. Here, we constructed a reporter system to easily and exactly monitor the in vivo arrest efficiency of VemP. Using this reporter system, we systematically performed a mutational analysis of the 20 residues (His138-Phe157) to identify and characterize the arrest motif. Our results show that 15 residues in the conserved region participate in elongation arrest and that multiple interactions between important residues in VemP and in the interior of the exit tunnel contribute to the elongation arrest of VemP. The arrangement of these important residues induced by specific secondary structures in the ribosomal tunnel is critical for the arrest. Pro scanning analysis of the preceding segment (Met120-Phe137) revealed a minor role of this region in the arrest. Considering these results, we conclude that the arrest motif in VemP is mainly composed of the highly conserved multiple residues in the C-terminal region.

Gastroduodenal Intussusception with a Gastric Gastrointestinal Stromal Tumor Treated by Endoscopic Submucosal Dissection.

A 95-year-old Japanese woman presented to our hospital with intermittent vomiting and several episodes of melena. Abdominal computed tomography revealed intussusception of the gastric tumor into the duodenum. After endoscopic reduction, endoscopic ultrasonography identified a hypoechogenic lesion limited to the submucosal layer. Endoscopic resection was performed as a localized treatment for the prevention of recurrent gastroduodenal intussusception. To our knowledge, there have been no other reports describing a gastric gastrointestinal stromal tumor presenting with gastroduodenal intussusception and treated using an endoscopic submucosal dissection technique.

Nascent chain-monitored remodeling of the Sec machinery for salinity adaptation of marine bacteria.

SecDF interacts with the SecYEG translocon in bacteria and enhances protein export in a proton-motive-force-dependent manner. Vibrio alginolyticus, a marine-estuarine bacterium, contains two SecDF paralogs, V.SecDF1 and V.SecDF2. Here, we show that the export-enhancing function of V.SecDF1 requires Na+ instead of H+, whereas V.SecDF2 is Na+-independent, presumably requiring H+. In accord with the cation-preference difference, V.SecDF2 was only expressed under limited Na+ concentrations whereas V.SecDF1 was constitutive. However, it is not the decreased concentration of Na+ per se that the bacterium senses to up-regulate the V.SecDF2 expression, because marked up-regulation of the V.SecDF2 synthesis was observed irrespective of Na+ concentrations under certain genetic/physiological conditions: (i) when the secDF1VA gene was deleted and (ii) whenever the Sec export machinery was inhibited. VemP (Vibrio export monitoring polypeptide), a secretory polypeptide encoded by the upstream ORF of secDF2VA, plays the primary role in this regulation by undergoing regulated translational elongation arrest, which leads to unfolding of the Shine-Dalgarno sequence for translation of secDF2VA. Genetic analysis of V. alginolyticus established that the VemP-mediated regulation of SecDF2 is essential for the survival of this marine bacterium in low-salinity environments. These results reveal that a class of marine bacteria exploits nascent-chain ribosome interactions to optimize their protein export pathways to propagate efficiently under different ionic environments that they face in their life cycles.

Solubility of Carbon Dioxide in Pentaerythritol Hexanoate: Molecular Dynamics Simulation of a Refrigerant-Lubricant Oil System.

We have investigated the solubility and the solvation structure between a refrigerant (carbon dioxide, CO2) and a lubricant oil (pentaerythritol hexanoate, PEC6) by molecular dynamics simulations. First, to investigate the solubility, we calculated the vapor-liquid equilibrium pressure. The chemical potential of the liquid phase and the gas phase were calculated, and the equilibrium state was obtained from the crossing point of these chemical potentials. The equilibrium pressures agreed well with experimental data over a wide range of temperatures and mole fractions of CO2. Second, the solvation structure was also investigated on a molecular scale. We found the following characteristics. First, the tails of the lubricant oil are relatively rigid inside the ester groups but flexible beyond. Second, CO2 molecules barely enter the lubricant core as delimited by the ester groups. Third, the double-bonded oxygen atoms of the ester groups are good sorption sites for CO2. Fourth, only a few CO2 molecules are attached to more than one carbonyl oxygen simultaneously. Finally, there is also significant unspecific sorption of CO2 in the alkane tail region. These results indicate that increasing the size of the rigid lubricant core would probably decrease the solubility, whereas increasing the number of polar groups would increase it.

Lymph node metastasis after endoscopic submucosal dissection of a differentiated gastric cancer confined to the mucosa with an ulcer smaller than 30 mm.

In the expanded indications for endoscopic resection, Japanese guidelines for gastric cancer include differentiated cancers confined to the mucosa with an ulcer <30 mm. We describe a patient with lymph node metastasis after curative endoscopic submucosal dissection (ESD) for a tumor of this indication. The patient was a 70-year-old man with chronic hepatitis C. He underwent ESD for early gastric cancer in May 2010. Pathology revealed a moderately differentiated adenocarcinoma, 22 × 17 mm in size, that was confined to the mucosa with an ulcer. The horizontal and vertical margins were negative for the tumor. We diagnosed thiscase as curative resection of expanded indication and followed this patient with endoscopy, abdominal ultrasonography (AUS) or enhanced computed tomography (CT) approximately every 6 months. After 17 months, lymph node metastasis was detected with AUS and CT and diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy in August 2011. Distal gastrectomy with D2 dissection was carried out in December 2011. Although it is low, the possibility of recurrence should be borne in mind after endoscopic treatment of early gastric cancer, despite its inclusion in the expanded indications for endoscopic resection.

Gastrointestinal stromal tumor of the ampulla of Vater: a case report.

Gastrointestinal stromal tumors (GISTs) usually develop in the stomach and small intestine and only rarely occur at the ampulla of Vater, with only 11 cases reported in the literature. We report a case of a GIST of the ampulla of Vater. A 36-year-old, previously healthy man presented with a loss of consciousness lasting a few minutes. A gastroduodenal endoscopy revealed a submucosal tumor with central ulceration at the ampulla of Vater. The enhanced computed tomography scan revealed a smooth-outlined hypervascular solid mass (24 mm × 30 mm) in the second part of the duodenum. Neither lymphadenopathy nor metastasis was observed. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed normal bile and pancreatic ducts. Biopsies were collected from the ulcerative lesion, and the tumor was diagnosed as a GIST. A submucosal tumor with central ulceration may be a characteristic form of GISTs of the ampulla of Vater, and biopsy studies are useful for the diagnosing such tumors. The patient underwent pancreatoduodenectomy, and the operative specimen revealed a 2.2-cm GIST with 1 mitosis per 50 high-power fields. The gold standard for treatment of GISTs is surgical resection without rupture of a capsule. If technically possible, local resection may be considered. However, when the location of the lesion presents challenges, a pancreatoduodenectomy should be performed for GIST of the ampulla of Vater.

Pseudoaneurysm caused by a self-expandable metal stent: a report of three cases.

We present three cases of pseudoaneurysm caused by self-expandable metal stents that formed arteriobiliary fistulas and caused hemobilia. Diagnoses were made on the basis of dynamic computed tomography or angiography. One patient died because of bleeding and cholangitis, whereas the others were successfully treated by transarterial embolization.

A case of primary pancreatic lymphoblastic lymphoma diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

Pancreatic involvement is an extremely rare manifestation of lymphoblastic lymphoma (LBL), and only a few cases have been reported. We report a case of LBL arising from the pancreas that was diagnosed using endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The patient was a 57-year-old female who had suffered from abdominal pain for 2 weeks. A physical examination revealed an upper abdominal mass, but did not detect peripheral lymphadenopathy. Imaging studies including computed tomography (CT) and (18)F-fluorodeoxy glucose (FDG)-positron emission tomography-CT revealed an enlarged pancreatic body, which was positive for FDG uptake. EUS-FNA detected medium-sized proliferating atypical lymphocytes, and immunohistochemical staining demonstrated that these cells were positive for CD20, CD10, PAX5, and terminal deoxynucleotidyl transferase. A bone marrow examination was negative for lymphoma infiltration, and a diagnosis of LBL arising from the pancreas was made. The patient was successfully treated with a combination of chemotherapy and pancreatic irradiation.

A case of focal autoimmune pancreatitis (AIP) mimicking an intraductal papillary mucinous neoplasm (IPMN).

The present case involved a 76-year-old man with a cystic mass in the head of his pancreas. The cystic lesion, which measured 17.7 × 9.8 mm, was first detected by ultrasonography (US) at the age of 72 years. Follow-up endoscopic ultrasonography (EUS) performed at 4 years after the lesion had first been detected revealed a mural nodule measuring 14.0 × 8.4 mm in the cyst. Endoscopic retrograde pancreatography (ERP) imaging revealed that the main pancreatic duct was in communication with the cyst and that there was no irregular narrowing of the main pancreatic duct. On the basis of these results, the patient was diagnosed with an intraductal papillary mucinous neoplasm (IPMN), and stomach-preserving pancreaticoduodenectomy was performed. A histopathological examination revealed that the interior of the cystic part of the lesion was lined by a pancreatic ductal epithelium. A pathological examination of the nodular lesion detected storiform fibrosis, severe lymphoplasmacytic infiltration, and hyperplasia in the pancreatic duct epithelium together with a small amount of mucus. On immunohistological staining, the infiltrating lymphoplasmacytes were found to be positive for IgG4. Accordingly, the patient was diagnosed with focal autoimmune pancreatitis (AIP). In conclusion, we reported a case of focal AIP mimicking IPMN. This case showed neither enlargement of the pancreas nor irregular narrowing of the main pancreatic duct.

Granular cell tumor of the common bile duct: a Japanese case.

Granular cell tumor (GCT) of the biliary system is rare. It is reported that it occurs more commonly in young black women. We report here our seldom experience of a Japanese case in whom icterus was found as a first symptom just after a caesarean operation. A 36-year-old Japanese woman developed icterus after delivery by the Caesarean operation. A surgical operation was performed without can deny that there was a tumor-related change in a bile duct as a result of examination for various images. As a result of pathological evaluation, GCT was diagnosed. By the preoperative organization biomicroscopy result, it was not able to be attachd a right diagnosis. It was thought that this tumor, although rare, should be considered as one of the causes of biliary stenosis in the younger population.

Criteria for non-surgical treatment of perforation during colorectal endoscopic submucosal dissection.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) has recently been applied in the treatment of large colorectal tumors. However, indications for emergent surgery and criteria for conservative treatment of perforation remain unclear. The aim of this study was to clarify the criteria for non-surgical treatment of perforation during colorectal ESD. METHODS: 219 colorectal tumors in 215 patients (136 men and 79 women; median age 69 years) were removed by performing ESD. The procedural outcomes, complications, prognoses, and criteria for non-surgical treatment of perforation were retrospectively analyzed by using our prospectively corrected database. RESULTS: The en-bloc and complete en-bloc resection rates were 92.7% (203/219) and 85.8% (188/219), respectively. The rate of discontinued ESD was 2.3% (5/219). The immediate and delayed perforation rates were 5.0% (11/219) and 0%, respectively. One of these patients required emergent surgery because of a residual lesion and localized peritonitis caused by an unsuccessful closure. The other 10 patients recovered with conservative treatment after successful closure with hemoclips and complete resection. The defects in all patients were successfully closed by using hemoclips. None of the patients had signs of diffuse peritonitis. The other factors, i.e. absence of localized peritonitis, high-grade fever, and acceleration of inflammatory reaction, were not associated with the success or the failure of the non-surgical treatment. CONCLUSIONS: The criteria for non-surgical treatment of perforation caused by colonic ESD were absence of diffuse peritonitis and successful closure.

Multicenter study of the long-term outcomes of endoscopic submucosal dissection for early gastric cancer in patients 80 years of age or older.

BACKGROUND: Little information is available on the long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in patients of advanced age (≥80 years). METHODS: A multicenter study was conducted at 10 Japanese institutions concerning their results for ESD. Data on 440 patients of advanced age (≥80 years) with EGC (470 lesions) were collected and reviewed. Early and long-term outcomes of ESD were assessed. We compared the overall survival rates between 3 patient groups, those with curative ESD, additional surgery after noncurative ESD, and nonsurgical follow-up after noncurative ESD. RESULTS: Bleeding and perforation rates were 3.2 and 2.8%, respectively. Curative ESD was achieved in 366 of the 470 lesions (77.9%). Of the 104 patients with noncurative ESD, 12 patients (11.5%) underwent additional surgery and 91 patients (87.5%) were followed without surgery. The 5-year survival rate in the patients with nonsurgical follow-up after noncurative ESD (66.7%) was significantly lower than that in the patients with curative ESD (80.3%, p = 0.0001). There was no significant difference in the 5-year survival rates between the patients with curative ESD and those with surgery after noncurative ESD (100%, p = 0.21), nor was there a difference in these rates between the patients with surgery after noncurative ESD and those with nonsurgical follow-up after noncurative ESD (p = 0.061). None of the patients developed cancer recurrence after curative ESD, and none developed cancer recurrence following the additional surgery after noncurative ESD. In the patients with curative ESD and in those with surgery after noncurative ESD, the cumulative observed survival was better than the expected survival for the general population of similar age and gender. CONCLUSIONS: ESD is safe for the treatment of EGC in patients 80 years of age or older. Both curative ESD and additional surgery after noncurative ESD may contribute to the extension of life expectancy.

[Case of von Hippel-Lindau disease diagnosed by detection of multiple pancreatic endocrine tumors and renal tumor 13 years after bilateral adrenalectomy].

von Hippel-Lindau (VHL) syndrome is an inherited neoplastic syndrome caused by abnormity of the VHL gene found on the short arm of the chromosome 3. We reported a case of VHL disease diagnosed by the detection of multiple pancreatic endocrine tumors and renal tumor 13 years after bilateral adrenalectomy. A 40-year-old man presented with multiple pancreas tumors (maximum size 42 mm in diameter) detected by screening abdominal ultrasonography. A 23 mm renal tumor was detected by contrast computed tomography scan at that time. His past history included left retinal angioma (age 15) and bilateral adrenal pheochromocytoma (age 27). VHL was diagnosed by genetic testing. Endoscopic ultrasound-guided fine-needle aspiration biopsy of the pancreas tumor was performed, and tumor was diagnosed as an endocrine tumor. After diagnosis, distal pancreatectomy (body-tail) was performed. This was a didactic case indicating that we should suspect VHL syndrome based on past history and family history and follow such cases up strictly.

[A case of duodenal gangliocytic paraganglioma with lymph node metastasis].

A 28-year-old man complained of tarry stool. A series of examinations showed a submucosal tumor with bleeding at the papilla of Vater and a swollen # 17b lymph node, both of which indicated a hypervascular tumor. The pathological findings of the enucleated tumor specimens revealed gangliocytic paraganglioma with metastasis to the # 17b lymph node. Additional pancreaticoduodenectomy revealed another # 17b lymph node metastasis 7-mm in diameter. Although the majority of gangliocytic paragangliomas are benign, 7% of reported cases have lymph node metastases, as shown in the present case. These findings are important in treating patients with gangliocytic paraganglioma.

[A case of duodenal carcinoma with massive peritoneal carcinomatosis complicating a pulmonary embolism].

The incidence of venous thromboembolism in cancer patients is reportedly around 15%, and a pulmonary embolism is an important cause of morbidity and mortality. We present a case of duodenal carcinoma with peritoneal carcinomatosis complicated by a pulmonary embolism. Heparin, followed by warfarin, was useful to treat the embolism. The combination chemotherapy with TS-1 and docetaxel was effective for the peritoneal carcinomatosis. The QOL of this patient was maintained for about 5 months.

[A case of advanced hepatocellular carcinoma with lung metastases and cirrhosis that responded to combination chemotherapy with interferon-alpha and 5-fluorouracil].

The prognosis for patients with hepatocellular carcinoma (HCC) with progressive liver cirrhosis or extrahepatic metastases remains dismal. We report a case of HCC with liver cirrhosis and lung metastases who had been treated successfully by combination chemotherapy of 5-fluorouracil (5-FU) and interferon-alpha (IFN-alpha). A 67-year-old male with a history of hepatitis C, liver cirrhosis and HCC was hospitalized because of cough and dyspnea. Computed tomography (CT) of chest revealed multiple lung metastases. Systemic combination chemotherapy with 5-FU and IFN-alpha was begun, and lung metastases disappeared after one course of treatment. He died of liver failure one year later, but no recurrence of lung metastases was seen. Although systemic combination chemotherapy of 5-FU and IFN-alpha induced the bone marrow suppression, it was effective for lung metastases and palliates symptoms and signs in our case of HCC.

Suspected paclitaxel-induced pneumonitis.

We report two patients with advanced gastric cancer with suspected paclitaxel-induced interstitial pneumonitis. Case 1, a 66-year-old man with recurrent gastric cancer, was treated weekly with paclitaxel. After 11 administrations of paclitaxel, he developed a nonproductive cough and dyspnea. Computed tomography (CT) scan showed extensive bilateral areas of ground-glass attenuation. He did not respond to corticosteroid, and died 57 days after the last paclitaxel administration. Case 2, a 61-year-old man with gastric cancer and liver metastasis, was treated with weekly paclitaxel. The liver metastasis was dramatically reduced in size, but he developed a nonproductive cough and dyspnea after 21 administrations of paclitaxel. He did not respond to high-dose corticosteroid, and died 50 days after the last paclitaxel administration. Although it is a rare complication, paclitaxel-induced interstitial pneumonitis needs to be considered in the differential diagnosis when patients treated with paclitaxel present with fever, nonproductive cough, and dyspnea.