Process Development for the Detoxification of Fermentation Inhibitors from Acid Pretreated Microalgae Hydrolysate.

The aim of this study was to remove 5-hydroxymethyl furfural (5-HMF) and furfural, known as fermentation inhibitors, in acid pretreated hydrolysates (APH) obtained from Scenedesmus obliquus using activated carbon. Microwave-assisted pretreatment was used to produce APH containing glucose, xylose, and fermentation inhibitors (5-HMF, furfural). The response surface methodology was applied to optimize key detoxification variables such as temperature (16.5-58.5 °C), time (0.5-5.5 h), and solid-liquid (S-L) ratio of activated carbon (0.6-7.4 w/v%). Three variables showed significant effects on the removal of fermentation inhibitors. The optimum detoxification conditions with the maximum removal of fermentation inhibitors and the minimum loss of sugars (glucose and xylose) were as follows: temperature of 36.6 °C, extraction time of 3.86 h, and S-L ratio of 3.3 w/v%. Under these conditions, removal of 5-HMF, furfural, and sugars were 71.6, 83.1, and 2.44%, respectively, which agreed closely with the predicted values. When the APH and detoxified APH were used for ethanol fermentation by S. cerevisiae, the ethanol produced was 38.5% and 84.5% of the theoretical yields, respectively, which confirmed that detoxification using activated carbon was effective in removing fermentation inhibitors and increasing fermentation yield without significant removal of fermentable sugars.

Clinical outcomes of upper gastrointestinal bleeding in patients with gastric gastrointestinal stromal tumor.

BACKGROUND: Upper gastrointestinal bleeding (UGIB) is one of the major manifestations of gastrointestinal stromal tumor (GIST) of the stomach. Several studies have reported that GIST bleeding is associated with poor prognosis. However, only case reports have reported hemostasis modalities for treating hemorrhagic gastric GIST. To identify clinical outcome of gastric GIST bleeding, we analyzed risk factors and prognosis of hemorrhagic GIST evaluating hemostasis methods. METHODS: Total 697 patients histopathologically diagnosed with primary gastric GIST between January 1998 and May 2015 were enrolled to the study, retrospectively. RESULTS: Of 697 total patients, 46 (6.6%) patients had UGIB. Endoscopic intervention, transarterial embolization, or surgical intervention was performed for initial hemostasis in 15, 2, and 1, respectively. Over a median of 68 months of follow-up, 16 patients in bleeding group and 88 patients in non-bleeding group died; the 5-year survival rate was 79.4% in bleeding group and 91.8% in non-bleeding group (p = 0.004). Multivariate analysis showed that significant risk factors for gastric GIST bleeding included the maximal tumor diameter > 5 cm and Ki-67 positivity. Age ≥ 60 [hazard ratio (HR) = 8.124, p = 0.048], necrosis (HR = 5.093, p = 0.027), and bleeding (HR 5.743, p = 0.034) were significant factors for overall survival of gastric GIST patients. CONCLUSIONS: Bleeding risk of gastric GIST was higher when tumor had diameter > 5 cm or Ki-67 positivity. In addition, tumor bleeding, necrosis, and age ≥ 60 years were associated with poor overall survival. Endoscopic intervention can be considered as an effective method for initial hemostasis of hemorrhagic gastric GIST.

Portal biliopathy treated with endoscopic biliary stenting.

Portal biliopathy is defined as abnormalities in the extra- and intrahepatic ducts and gallbladder of patients with portal hypertension. This condition is associated with extrahepatic venous obstruction and dilatation of the venous plexus of the common bile duct, resulting in mural irregularities and compression of the biliary tree. Most patients with portal biliopathy remain asymptomatic, but approximately 10% of them advance to symptomatic abdominal pain, jaundice, and fever. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography are currently used as diagnostic tools because they are noninvasive and can be used to assess the regularity, length, and degree of bile duct narrowing. Management of portal biliopathy is aimed at biliary decompression and reducing the portal pressure. Portal biliopathy has rarely been reported in Korea. We present a symptomatic case of portal biliopathy that was complicated by cholangitis and successfully treated with biliary endoscopic procedures.

A large-sized phytobezoar located on the rare site of the gastrointestinal tract.

Bezoars are concretions of undigested material and are most often observed in the stomach. They can occur at any site in the gastrointestinal tract; however, duodenal localization is very rare. We report the case of a 71-year-old male who had undergone subtotal gastrectomy with gastroduodenostomy and experienced severe epigastric discomfort, abdominal pain, and vomiting for a few days. An approximately 7×8 cm-sized mass was found on an abdominal computed tomography scan. On following endoscopy, a large bezoar was revealed in the duodenum and was removed using an endoscopic removal technique, assisted by a large amount of Coca-Cola infusion.

Two Cases of Diffuse Large B-Cell Lymphomas in the Cervical Lymph Nodes in Patients with Low-Grade Gastric Marginal Zone B-Cell Lymphoma (MALT Lymphoma).

It is well known that gastric mucosa-associated lymphoid tissue (MALT) lymphomas are associated with Helicobacter pylori infection and have a good prognosis. However, although rare, these low-grade lymphomas transform to the high-grade diffuse large B-cell lymphomas (DLBCLs) which are thought to be the important cause of death in patients with MALT lymphoma. We report two cases of DLBCLs in the cervical lymph nodes that occurred 10 years and 1.5 years after diagnosing low-grade gastric MALT lymphomas.