Generation of a novel monoclonal antibody against inflammatory biomarker S100A8 using hybridoma technology.

OBJECTIVES: S100A8 is highly expressed in several inflammatory and oncological conditions. To address the current lack of a reliable and sensitive detection method for S100A8, we generated a monoclonal antibody with a high binding affinity to human S100A8 to enable early disease diagnosis. RESULTS: A soluble recombinant S100A8 protein with a high yield and purity was produced using Escherichia coli. Next, mice were immunized with recombinant S100A8 to obtain anti-human S100A8 monoclonal antibodies using hybridoma technology. Lastly, the high binding activity of the antibody was confirmed and its sequence was identified. CONCLUSIONS: This method, including the production of antigens and antibodies, will be useful for the generation of hybridoma cell lines that produce anti-S100A8 monoclonal antibodies. Moreover, the sequence information of the antibody can be used to develop a recombinant antibody for use in various research and clinical applications.

A rapid ELISA for the detection of matrix metallopeptidase 9 using a recombinant Fab-type antibody.

Matrix metalloproteinase 9 (MMP9) contributes to several aspects of inflammation and cancer pathology, including invasion, metastasis, and angiogenesis. In this study, we expressed a recombinant fragment antigen-binding (Fab)-type anti-MMP9 antibody in Escherichia coli with high purity within five days and confirmed the nanomolar order of antigen-binding efficiency of the recombinant Fab. Moreover, we optimized the experimental time for performing enzyme-linked immunosorbent assay (ELISA), and decreased the reaction time from the conventional 20.5 h to 3.5 h. The rapid and sensitive MMP9 detection system developed in this study can be applied to a range of applications, including the diagnosis of diseases with MMP9 overexpression including inflammatory and cancer-related diseases.

Generation of Q-bead against bone Gla protein with simplified preparation steps.

Quenchbody (Q-body)-based immunoassays enable the detection of antigen within a few minutes with high sensitivity and specificity, thereby revealing their applicability as biosensors for quantifying several biomolecules of interest; however, while producing a Q-body, it is necessary to eliminate the unconjugated dye after labeling to separate the Q-body from the capturing bead and to change the buffer using ultrafiltration, which is time-consuming and leads to yield reduction. In this study, we generated a recombinant single chain variable fragment against bone Gla protein as a model antibody. We labeled the antibody with a dye to generate a Q-body and subsequently added affinity beads to the Q-body mixture. After washing, we directly added antigen without extracting the Q-body from the bead and then measured the fluorescence intensity. As a result, the antigen-dependent fluorescence response was obtained from "Q-bead", which was almost the same as that of the Q-body generated according to the conventional method. The Q-bead was generated within only 2.5 h, thus requiring an hour and two steps less than those required for the generation of the traditional Q-body. No expensive Flag peptide was required to recover the total antibody from beads. Moreover, the ultra-filtration step was eliminated in this bead-based method, leading to improved convenience and cost- and time-saving attributes. The Q-bead-based assay can be used as a standard protocol for simple and rapid analysis of antibody-based molecular detection.

[Non-endoscopic predictors of large esophageal varices in patients with liver cirrhosis].

BACKGROUND/AIMS: The aim of this study was to identify non-endoscopic predictors for the presence of large esophageal varices in Korean patients with liver cirrhosis. METHODS: Among 736 patients with liver cirrhosis newly diagnosed between the year 2001 and 2005, 245 patients (171 men and 74 women, mean age of 51.9 years) fulfilled the inclusion criteria and underwent EGD as screening tests for esophageal varices. Fifteen variables were analysed to identify the presence of large esophageal varices. RESULTS: Esophageal varices were noted in 186 patients (75.9%) and large varices in 55 patients (22.4%), while 59 patients (24.1%) had no varices at the time of initial diagnosis of cirrhosis. The causes of liver cirrhosis were viral hepatitis (41.2%), chronic alcoholism (42.4%), viral hepatitis/alcoholism (9.8%), and others (6.6%). Fifty-one percent, 35.1% and 13.9% of the patients belonged to Child-Pugh class A, B, and C, respectively. Variables associated with the presence of large esophageal varices on univariate analysis were the presence of ascites, splenomegaly (long-axis >or= 12 cm by ultrasound measure), alcoholism, Child-Pugh class, platelet count, prothrombin time, and albumin. On multivariate analysis, alcohol, splenomegaly, and ascites were significantly associated with the presence of large esophageal varices. If the patients have two of them, sensitivity and negative predictive value were 80% and 91.7%, respectively. Patients without all three factors had no large esophageal varices. CONCLUSIONS: These results suggest that patients who have at least two among ascites, splenomegaly, and alcoholism would have an increased risk of having large esophageal varices.

[Macro-aspartate aminotransferase in a patient with chronic hepatitis C].

Macroenzymes are normal enzymes complexed with an immunoglobulin (usually IgG, rarely IgA or IgM). A number of macroenzymes have been reported in the literature. Among them, macro-AST has been detected in diseases such as acute and chronic hepatitis, various malignancies and autoimmune diseases, but usually not associated with any specific disease. We report a case of elevated AST activity in serum due to marco-AST formation in a female with chronic hepatitis C which was confirmed by AST isoenzyme electrophoresis. To our knowledge, this is the first report of macro-AST occurred in chronic hepatitis patient in Korea.

Localized esophageal ulcerations after CyberKnife treatment for metastatic hepatic tumor of colon cancer.

CyberKnife is an image-guided robotic system designed for stereotactic radiosurgery. It uses the combination of robotics and image guidance to deliver concentrated and accurate beams of radiation to intracranial and extracranial targets. Although the frameless nature of the CyberKnife allows tumors in the chest and abdomen to be treated as well, complications associated with CyberKnife treatment have not been established yet due to its short clinical experience. We describe a case of localized esophageal ulcerations after CyberKnife treatment for metastatic hepatic tumor of colon cancer.

[A case of colon cancer associated with Crohn's disease].

Colon cancer is the most serious intestinal complication in patients with Crohn's disease. Although an association between Crohn's disease and colon cancer has not been clearly defined, a number of studies in western countries reported an increased rate of colon cancer in patients with Crohn's disease. In Korea, Crohn's disease is rare when compared to western countries, and only a single case of colon cancer associated with Crohn's disease has been reported. We recently experienced a 66-year-old women with colon cancer associated with Crohn's disease.

[A case of acute cholecystitis secondary to hemobilia after percutaneous liver biopsy].

Percutaneous liver biopsy is well established for the diagnosis and follow-up of many liver diseases. Although it is rather safe, major complications, such as bleeding into the peritoneal or thoracic cavity, hemobilia, enteric perforation and intrahepatic hematoma, have been reported related to the procedure. Recently, incidence of such major complications has been decreased since the introduction of ultrasonography-guided liver biopsy. We report a case of 59-year-old female patient with acute cholecystitis secondary to hemobilia 2 days after ultrasonography-guided percutaneous liver biopsy.

[Association of hepatic iron deposition and serum iron indices with hepatic inflammation and fibrosis stage in nonalcoholic fatty liver disease].

BACKGROUND/AIMS: Nonalcoholic steatohepatitis can develop from nonalcoholic fatty liver and progress to severe liver disease such as cirrhosis. The mechanism determining the progression from fatty liver to steatohepatitis is unknown. Iron is suspected to enhance hepatic damage associated with nonalcoholic fatty liver disease (NAFLD). The aims of this study were to evaluate the relationship of serum iron indices and hepatic iron deposition with hepatic fibrosis or inflammation, and to assess whether the increased hepatic iron deposition is an independent predictor of progression to liver injury. METHODS: The biochemical and histopathological data of thirty-nine patients with NAFLD were analyzed. Liver biopsy findings were graded according to the method described by Brunt, et al. Hepatic iron concentration was available in 29 of 39 patients. RESULTS: The mean hepatic iron concentration and hepatic iron indices were 1,349+/-1,188 microg/g dry weight and 0.9+/-0.7 microg/g/age. Serum ferritin and body mass indices were associated with hepatic inflammation (p=0.001, p=0.006) and fibrosis (p=0.005, p=0.013). Hepatic iron concentration and hepatic iron index were not associated with hepatic inflammation and fibrosis. Multivariate analysis did not identify serum ferritin or body mass index as an independent predictor of liver injury. CONCLUSIONS: Hepatic iron deposition shows no association with the degree of hepatic inflammation or fibrosis. Hepatic iron is not an independent predictor of hepatic injury in patients with NAFLD.

[A case of adenosquamous carcinoma of the papilla of Vater].

Adenosquamous carcinoma of the papilla of Vater is a rare tumor and only a few cases have been reported so far. Here, we report a case of adenosquamous carcinoma in a 76-year-old male who presented with jaundice and right upper quadrant abdominal pain. Ultrasonography and enhanced abdominal CT scans showed dilated common bile duct (CBD) and intrahepatic bile duct (IHD) with a suspicious obstructing mass in distal CBD. On endoscopy, obstructing and ulcerated mass was noted on the papilla of Vater. Histopathological inspection of the biopsied specimens from mass showed adenosquamous cell carcinoma of the papilla of Vater. Since the patient refused operation, we inserted a self-expandable metallic stent in distal CBD. This is the first case report on adenosquamous carcinoma of the papilla of Vater in Korea.

[A case of hemolytic uremic syndrome with hemorrhagic colitis due to Escherichia coli O111 infection].

Shiga toxin producing E. coli (STEC) may cause severe hemorrhagic colitis followed by hemolytic uremic syndrome (HUS). In Korea, there had been a few case reports of HUS by STEC, mostly due to O157 serotype. The reports of HUS caused by STEC non-O157 serotype were rare. We report a sporadic case of HUS associated with hemorrhagic colitis. A 51-year-old woman was admitted to our hospital due to intractable abdominal pain and bloody diarrhea. Three days after admission, azotemia and microangiopathic hemolysis developed. E. coli, serotype O111 was identified. Conservative management with plasmapheresis resulted in a complete recovery.

[A case of spontaneous perforation of the common bile duct associated with cholangitis].

Spontaneous perforation of the common bile duct (CBD) is a rare event in adults. Most cases of CBD perforation are iatrogenic after invasive procedures such as endoscopic retrograde cholangiopancreatography (ERCP) or cholecystectomy. We report a case of an 81-year-old woman who presented with severe right upper abdominal pain, fever, and chills. Abdominal CT showed multiple gallbladder and CBD stones and loculated fluid collection in the inferoposterior portion of the stomach. ERCP showed the leakage of contrast media into the peritoneal cavity from the CBD. We performed endoscopic sphincterotomy (EST) and endoscopic nasobiliary drainage (ENBD) to decompress the CBD instead of emergent surgical intervention. One week later, cholangiography via ENBD tube revealed that there was no more leakage of the contrast media from the CBD. We performed cholecystectomy, removal of the CBD stones after exploration of the CBD, and T tube insertion. The perforated site of the CBD was closed and there was no more fluid collection in the inferoposterior portion of the stomach. Medical treatment including endoscopic procedures was useful for healing of the perforated CBD.

[A case of retroperitoneal schwannoma of the vagus nerve].

Schwannomas are benign nerve sheath tumors that originate from any anatomical site. Most schwannomas occur in the head, neck or limbs, but rarely occur in the retroperitoneal space. Furthermore, the schwannoma originating from the vagus nerve of retroperitoneal space is much rare. We experienced a case of retroperitoneal schwannoma of the vagus nerve. A 34-year-old male was referred to our hospital for the evaluation of abdominal mass on ultrasonography. Endoscopic examination revealed submucosal tumor-like lesion on high body of the stomach. Computed tomography (CT) revealed that the stomach was compressed by a solid tumor in the retroperitoneum. On exploratory laparotomy, this mass turned out to be a baseball sized mass in the retroperitoneal space. The mass was excised in an encapsulated state. Histological examination with immunohistochemical stains revealed a schwannoma of the vagus nerve.

[A case of methicillin resistant Staphylococcus aureus enterocolitis presenting with massive diarrhea].

Methicillin resistant Staphylococcal aureus (MRSA) enterocolitis is characterized by high fever, abdominal distension, and watery diarrhea that leads to severe dehydration, shock, a sharp decrease in the white cell counts and sometimes multiple organ failure. Clinically, it can be an another cause of nosocomial diarrhea. If MRSA enteritis is suspected from the clinical symptoms, prompt treatment and strict prophylactic measures including vancomycin, are most important for its management. We recently observed a case of MRSA enterocolitis as a nosocomial infection in a patient with acute pancreatitis. This patient showed uncontrolled massive diarrhea, fever, and multiple organ failure. We report a case of MRSA enterocolitis with a review of literatures.

[The recurrence rate of colon polyp after polypectomy and the interval of surveillance colonoscopy: predictors of early development of advanced polyp].

BACKGROUND/AIMS: Surveillance of individuals with colon polyps is important for the prevention of colon cancer, and its interval is based on the clinical status. Our aims were to determine the recurrence rate of advanced polyp after polypectomy and estimate the adequate interval of surveillance colonoscopy as well as the risk factors of recurrence in Korea. METHODS: Ninety-seven patients who underwent follow-up colonoscopy after initial colonoscopic polypectomy were retrospectively studied. All polyps were endoscopically removed with electrocautery. RESULTS: Mean number of initial polyps were 2.2 and advanced polyps were observed in 40% of the patients. The cumulative recurrence rate of colon polyp was 13.8% within 1 year, and 60% within 3 years, while that of advanced polyps was 2.5% and 31% within 1 and 3 years, respectively. The significant difference was noted according to the initial polyp number in both overall and advanced polyp recurrence rate. The age at the diagnosis of colon polyps was a significant factor only in overall polyp recurrence rate. Patients who initially had one polyp showed 15% of advanced polyp recurrence within 3 years. CONCLUSIONS: Recurrence of advanced polyp is very rare within one year after polypectomy. Patients with single polyp have low risk and thus, their surveillance may be delayed beyond the standard 3 years. When surveillance colonoscopy is to be performed for the patients with 2 or more polyps, initial polyp number and age should be considered.

Cytomegalovirus colitis manifested with a ring like ileocecal valve ulcer in a Korean AIDS patient.

A 32-year-old man, who had no previous medical history, was hospitalized with 3-week duration of abdominal pain, fever, and watery diarrhea. Initial colonoscopy showed subepithelial hemorrhagic spots throughout the entire colon together with well-circumscribed ulcer around the ileocecal valve. Serologic test disclosed HIV-positive and repeated biopsies at ulcer base finally revealed that the patient had cytomegalovirus ulcer in ileocecal area.

[Importance of age and other risk factors in NSAID-induced gastropathy].

BACKGROUND/AIMS: It is clinically important to analyze the risk factors of NSAID-induced gastropathy because there could be no symptoms. Age is the most important risk factor according to previous reports. The aim of this study was to find risk factors of NSAID-induced gastropathy and to confirm the association between NSAID-induced gastropathy and age. METHODS: We retrospectively assessed 300 patients who conducted an upper gastroscopy during the course of chronic NSAID treatment. RESULTS: Median age of patients group is 51.4 +/- 12.2 years. In multivariate analysis, age and ulcer history are two significant risk factors. Median age is 46.7 +/- 10.7 years for the patients with nonspecific gastroscopic finding, 53.0 +/- 12.5 for those with erosion, 57.6 +/- 10.0 for those with ulcer, and 63.2 +/- 8.9 for those with hemorrhage. The proportion of ulcer patients is as follows: 6% in the patients of under 40 years old, 14.9% in patients of the 40s, 20% in patients of the 50s, 30.9% in patients of the 60s, 33.3% in patients over 70 years. The proportion of nonspecific findings is 62.2% in patients of the 40s, 37.8% in patients of the 50s, and 29% in patients over 60 years. CONCLUSIONS: Age is the most important risk factor of the NSAID-induced gastrointestinal mucosal injury. A larger randomized prospective control study will be required in the future for more conclusive results.

[Clinical features of obscure-overt gastrointestinal bleeding].

BACKGROUND/AIMS: Obscure gastrointestinal bleeding (OGIB) is defined as recurrent acute or chronic bleeding for which no sources have been identified by routine endoscopic and contrast studies. The patients with OGIB are frequently difficult to manage and often undergo extensive investigation and even laparatomy without diagnosis. The aim of this study was to review our overall experiences of the investigation and treatment of OGIB. METHODS: We reviewed, retrospectively, medical records of 41 cases with OGIB from June 1996 to July 2002. RESULTS: Of the 41 patients with OGIB, there were 21 men and 20 women and their mean age was 47.8 years (range, 18 to 81 years). Diagnosis was possible in 13 patients (31.7%) and no specific causes were identified in the remaining 28 patients (68.3%). The principal etiologies were gastrointestinal stromal tumor of the small bowel in 3 cases, duodenal diverticulum in 2 cases. Other causes are as follows: adenocarcinoma of the duodenal 3rd portion, duodenal varix at the 4th portion, splenic artery pseudoaneurysm, Crohn's disease, jejunal ulcer, ileal ulcer, ileal angiodysplasia, and anastomosis site bleeding after hemicolectomy. CONCLUSIONS: We conclude that further and logical diagnostic investigations such as small bowel enteroscopy and wireless capsule endoscopy will promise better results.

[Expression of Cdx-2 homeobox gene in intestinal metaplasia and gastric adenocarcinoma].

BACKGROUND/AIMS: The Cdx-1 and Cdx-2 genes are intestinal transcription factors that may be involved in the regulation of proliferation and differentiation of intestinal epithelial cells. The Cdx-1 and Cdx-2 are expressed in the epithelium of the small intestine and colon but not in the normal epithelium of the esophagus and stomach. Conversely, aberrant Cdx-2 expression is often observed in the esophagus and stomach. We investigated the expression and role of Cdx-2 in intestinal metaplasia and gastric adenocarcinoma. METHODS: The gastric tissues obtained endoscopically were analyzed by the reverse transcriptase-polymerase chain reaction and histology. The Cdx-1 and Cdx-2 mRNA expression was confirmed and analyzed according to updated Sydney classification. Then, immunohistochemical study with monoclonal anti-Cdx-2 antibody was performed with gastric adenocarcinoma obtained by surgical resection. RESULTS: The prevalence of Cdx-1 and Cdx-2 mRNA expression was significantly higher in mucosa with intestinal metaplasia than mucosa without intestinal metaplasia. In immunohistochemical study, nuclear staining of Cdx-2 was strong in metaplastic mucosa, but weak in adjacent normal gastric mucosa (p<0.001). The expression of Cdx-2 in gastric adenocarcinoma was lower than in metaplastic mucosa (p<0.001). The Cdx-2 expression was also detected in 97% of intestinal type gastric adenocarcinoma and 61.5% of diffuse type gastric adenocarcinoma (p=0.003). CONCLUSIONS: Aberrant expression of Cdx-2 is observed in intestinal metaplasia and a subset of gastric adenocarcinoma, which is predominant in intestinal-type gastric adenocarcinoma. Therefore, Cdx-2 may play an important role in gastric carcinogenesis, especially in intestinal type adenocarcinoma.

[Clinical characteristics of acute toxic liver injury].

BACKGROUND/AIMS: Recently, acute toxic liver injury has been reported to be the most common cause of acute hepatitis. The frequency and clinical manifestations of acute toxic liver injury was evaluated. METHODS: The medical records of 68 patients demonstrating clinically significant acute toxic liver injury were retrospectively reviewed. Patients with mild biochemical abnormalities were excluded. RESULTS: The annual percentage of toxic liver injury ranged from 50% to 90% among acute hepatitis groups. Among the causes, prescribed drugs (group D) accounted for 55%, herbs or plant products (group H) for 42% and both accounted for 3%. Antibiotics and anti-inflammatory drugs were the most common agents (78%) among group D. The mean age of the patients was 43 and 70% of patients were female. Of the population, common symptoms were jaundice, weakness, fatigue, and nausea. Initial ALT and AST levels were 847 +/- 879 and 664 +/- 625 IU/L, and initial total bilirubin was 7.5 +/- 8.1 mg/dL. Acute toxic liver injury occurred after a mean of 32 days after first exposure. Liver injury resolved within a mean of 32 days. Hepatocellular, mixed, and cholestatic type was 45.2%, 32.3%, 22.5%, respectively. CONCLUSIONS: Recently, acute toxic liver injury has been the most common cause of acute hepatitis in Korea. Prescribed drugs and herbs or plant products are equally important etiologic agents of toxic liver injury. However, etiologic difference may not affect clinical courses or outcomes. A nationwide investigation of the hepatotoxicity of drugs, herbs or other plant products is required.