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.

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.

[Clinicopathologic characteristics of superficial gastric cancer diagnosed at primary health care institutions in 2011].

BACKGROUND/AIMS: Stomach cancer is prevalent in Korea. The purpose of this study was to evaluate the characteristics of superficial gastric cancers detected at SOK Sokpeynhan Internal Medical Network, the nationwide primary health care institutions. METHODS: We prospectively analysed the clinicopathologic and endoscopic characteristics of 218 superficial gastric cancer patients diagnosed using gastric endoscopy at SOK network from January 2011 through December 2011. RESULTS: The mean age was 58.5 years old and male to female ratio was 1.7 : 1. Asymptomatic patients were most common (45.0%). The macroscopic classification revealed that simple types (63.8%) were more common than complex types (36.2%). The most common type was IIc (28.4%) and other types were as follows; IIb (16.1%), IIb+IIc (13.3%), IIa (10.6%), III (9.2%), IIa+IIc (7.3%), IIc+IIa (6.0%), IIc+IIb (5.0%). The most commonly involved sites were the body (53.1%) and greater curvature (32.6%) of the stomach. The size of lesion was less than 1 cm (69.3%) and less than 5 mm (33.5%) in diameter. The most common pathologic type was tubular adenocarcinoma (75.7%). Helicobacter pylori infection rate was 50.2%. Fifty five percent of the cases were diagnosed via endoscopy of National Health Insurance Corporation screenings. CONCLUSIONS: Superficial gastric cancers in 2011 at primary health care SOK network were different from those of previous reports. Type IIc was most common but type IIb was more prevalent and the body and greater curvature of the stomach were the most commonly involved sites. Therefore, careful observation of the proximal gastric mucosa and mucosal color change is needed.

The Miss Rate for Colorectal Adenoma Determined by Quality-Adjusted, Back-to-Back Colonoscopies.

BACKGROUND/AIMS: Colonoscopy is considered to be the gold standard for detecting adenomatous polyps. Polyps are missed during colonoscopic examination at a rate that varies from 6% to 27%. The adenoma miss rate affects colonoscopic surveillance intervals and procedural quality. We aimed to assess the adenoma miss rate and the variables affecting the rate using same-day, quality-adjusted, back-to-back colonoscopies. METHODS: This prospective study was performed at a single institution and included 149 patients. Two consecutive same-day colonoscopies were performed by two experienced endoscopists. The adenoma miss rates and variables affecting the missed adenomas, including polyp characteristics and procedure times, were evaluated. RESULTS: The miss rates of polyps, adenomas, and advanced adenomas were 16.8%, 17%, and 5.4%, respectively. The smaller polyps and increased number of polyps detected during the first colonoscopy were more likely to be missed. A longer insertion time during the colonoscopy was correlated with an increased adenoma detection rate. CONCLUSIONS: There was a significant miss rate in the detection of colonic adenomas even in quality-adjusted, back-to-back colonoscopies. The adenoma miss rate can be reduced with a sufficient observation time during colonoscopic insertion. The development of specific technological methods to reduce the adenoma miss rate is necessary.

[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.

Simple tests to predict hepatic fibrosis in nonalcoholic chronic liver diseases.

BACKGROUND/AIMS: Several simple tests for hepatic fibrosis employ indirect markers. However, the efficacy of using direct and indirect serum markers to predict significant fibrosis in clinical practice is inconclusive. We analyzed the efficacy of a previously reported indirect marker of hepatic fibrosis - the aspartate aminotransferase to platelet ratio index (APRI) - in patients with nonalcoholic chronic liver diseases (CLDs). METHODS: A total of 134 patients who underwent a percutaneous liver biopsy with a final diagnosis of chronic hepatitis B (n=93), chronic hepatitis C (n=18), or nonalcoholic fatty liver disease (n=23) were enrolled. A single-blinded pathologist staged fibrosis from F0 to F4 according to the METAVIR system, with significant hepatic fibrosis defined as a METAVIR fibrosis score of >/=2. RESULTS: The mean area under the receiver operating characteristic curve (AUROC) of APRI for predicting significant fibrosis in nonalcoholic CLDs was 0.84 [95% confidence interval (CI), 0.78-0.91]. APRI yielded the highest mean AUROC in the patients with chronic hepatitis B (0.85; 95% CI, 0.771-0.926). The positive predictive value of APRI >/=1.5 for predicting significant fibrosis was 89%. The negative predictive value of APRI <0.5 for excluding significant fibrosis was 80%. CONCLUSIONS: APRI might be a simple and noninvasive index for predicting significant fibrosis in nonalcoholic CLDs.

[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 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.

[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.

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.

[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.

[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.

[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 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 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.