Gene Expression Analyses of Mutant Flammulina velutipes (Enokitake Mushroom) with Clogging Phenomenon

Regulation of proper gene expression is important for cellular and organismal survival, maintenance, and growth. Abnormal gene expression, even for a single critical gene, can thwart cellular integrity and normal physiology to cause diseases, aging, and death. Therefore, gene expression profiling serves as a powerful tool to understand the pathology of diseases and to cure them. In this study, the difference in gene expression in Flammulina velutipes was compared between the wild type (WT) mushroom and the mutant one with clogging phenomenon. Differentially expressed transcripts were screened to identify the candidate genes responsible for the mutant phenotype using the DNA microarray analysis. A total of 88 genes including 60 upregulated and 28 downregulated genes were validated using the realtime quantitative PCR analysis. In addition, proteomic differences between the WT and mutant mushroom were analyzed using two–dimensional gel electrophoresis and matrixassisted laser desorption/ionization-time of flight (MALDI-TOF). Interestingly, the genes identified by these genomic and proteomic analyses were involved in stress response, translation, and energy/sugar metabolism, including HSP70, elongation factor 2, and pyruvate kinase. Together, our data suggest that the aberrant expression of these genes attributes to the mutant clogging phenotype. We propose that these genes can be targeted to foster normal growth in F. velutipes.

Penicillium ulleungdoense sp. nov. from Ulleung Island in Korea

In a study of the fungal diversity on Ulleung Island in Korea, three novel strains of Penicillium were isolated. Different sites on Ulleung Island were selected for collecting endophytic fungi, and three endophytic fungal strains showed unique morphological characteristics. DNA sequence of the internal transcribed spacer, β-tubulin, calmodulin, and RNA polymerase II second largest subunit regions of the strains were analyzed and they showed unique taxonomic position from the other species of Penicillium section Sclerotiora. The new strains were named Penicillium ulleungdoense sp. nov. As the novel endophytic Penicillium taxa were discovered in a unique environment, the data could be meaningful for understanding the geographical distribution of Ascomycetes on Ulleung Island.

Distribution, Characterization, and Diversity of the Endophytic Fungal Communities on Korean Seacoasts Showing Contrasting Geographic Conditions

This study analyzed the distribution of endophytic fungi in 3 coastal environments with different climatic, geographical, and geological characteristics: the volcanic islands of Dokdo, the East Sea, and the West Sea of Korea. The isolated fungal endophytes were characterized and analyzed with respect to the characteristics of their host environments. For this purpose, we selected common native coastal halophyte communities from three regions. Molecular identification of the fungal endophytes showed clear differences among the sampling sites and halophyte host species. Isolates were also characterized by growth at specific salinities or pH gradients, with reference to previous geographical, geological, and climate studies. Unlike the East Sea or West Sea isolates, some Dokdo Islands isolates showed endurable traits with growth in high salinity, and many showed growth under extremely alkaline conditions. A smaller proportion of West Sea coast isolates tolerate compared to the East Sea or Dokdo Islands isolates. These results suggest that these unique fungal biota developed through a close interaction between the host halophyte and their environment, even within the same halophyte species. Therefore, this study proposes the application of specific fungal resources for restoring sand dunes and salt-damaged agricultural lands and industrialization of halophytic plants.

Aspergillus clavatus Y2H0002 as a New Endophytic Fungal Strain Producing Gibberellins Isolated from Nymphoides pe ltata in Fresh Water

Eighteen endophytic fungi with different colony morphologies were isolated from the roots of Nymphoides peltata growing in the Dalsung wetland. The fungal culture filtrates of the endophytic fungi were treated to Waito-c rice seedling to evaluate their plant growth-promoting activities. Culture filtrate of Y2H0002 fungal strain promoted the growth of the Waito-c rice seedlings. This strain was identified on the basis of sequences of the partial internal transcribed spacer region and the partial beta-tubulin gene. Upon chromatographic analysis of the culture filtrate of Y2H0002 strain, the gibberellins (GAs: GA1, GA3, and GA4) were detected and quantified. Molecular and morphological studies identified the Y2H0002 strain as belonging to Aspergillus clavatus. These results indicated that A. clavatus improves the growth of plants and produces various GAs, and may participate in the growth of plants under diverse environmental conditions.

Diversity of Endophytic Fungi Associated with the Roots of Four Aquatic Plants Inhabiting Two Wetlands in Korea

A total of 4 aquatic plants, Eleocharis kuroguwai Ohwi, Hydrocharis dubia Backer, Salvinia natans All., and Zizania latifolia Turcz., were sampled from representative two wetlands of South Korea. A total of 38 endophytic fungal strains were isolated from aquatic plants native to the Daepyeong wetland, and 27 strains were isolated from the Jilnal wetland. The internal transcribed spacer regions of fungal isolates were sequenced and a phylogenetic analysis was performed. In addition, endophytic fungal diversity from each wetland and host plant species was deduced. A total of 25 fungal genera were purely isolated, and 16 fungal genera were isolated from each of the two wetlands. Commonly isolated genera from both wetlands were Aspergillus, Cladosporium, Clonostachys, Fusarium, Leptosphaeria, Penicillium, and Talaromyces. This study revealed that fungal diversity varied with environmental conditions and by host plant in representative two wetlands.

Diversity and Plant Growth Promoting Capacity of Endophytic Fungi Associated with Halophytic Plants from the West Coast of Korea

Five halophytic plant species, Suaeda maritima, Limonium tetragonum, Suaeda australis, Phragmites australis, and Suaeda glauca Bunge, which are native to the Muan salt marsh of South Korea, were examined for fungal endophytes by sequencing the internal transcribed spacer (ITS) region containing ITS1, 5.8S rRNA, and ITS2. In total, 160 endophytic fungal strains were isolated and identified from the roots of the 5 plant species. Taxonomically, all 160 strains belonged to the phyla Ascomycota, Basidiomycota, and Zygomycota. The most dominant genus was Fusarium, followed by the genera Penicillium and Alternaria. Subsequently, using 5 statistical methods, the diversity indices of the endophytes were determined at genus level. Among these halophytic plants, P. australis was found to host the greatest diversity of endophytic fungi. Culture filtrates of endophytic fungi were treated to Waito-C rice seedlings for plant growth-promoting effects. The fungal strain Su-3-4-3 isolated from S. glauca Bunge provide the maximum plant length (20.1 cm) in comparison with wild-type Gibberella fujikuroi (19.6 cm). Consequently, chromatographic analysis of the culture filtrate of Su-3-4-3 showed the presence of physiologically active gibberellins, GA(1) (0.465 ng/mL), GA(3) (1.808 ng/mL) along with other physiologically inactive GA(9) (0.054 ng/mL) and GA(24) (0.044 ng/mL). The fungal isolate Su-3-4-3 was identified as Talaromyces pinophilus.

Culturable Fungal Endophytes Isolated from the Roots of Coastal Plants Inhabiting Korean East Coast

Twelve plant species were collected from the east coast of Korea to identify culturable endophytes present in their roots. The fungal internal transcribe spacer (ITS) region (ITS1-5.8SrRNA-ITS2) was used as a DNA barcode for identification of fungi. A total of 194 fungal strains were identified and categorized into 31 genera. The genus Penicillium accounted for the largest number of strains, followed by the genus Aspergillus. Furthermore, using 5 statistical methods, the diversity indices of the fungi were calculated at the genus level. After comprehensive evaluation, the endophytic fungal group from Phragmites australis ranked highest in diversity analyses. Several strains responsible for plant growth and survival (Penicillium citrinum, P. funiculosum, P. janthinellum, P. restrictum, and P. simplicissimum), were also identified. This study provides basic data on the sheds light on the symbiotic relationship between coastal plants and fungi.

Risk and culture: variations in dioxin risk perceptions, behavioral preferences among social groups in South Korea

OBJECTIVES: This study examined variations in the perceptions of dioxin risk among social groups defined by geographical living location, environmental education, and occupation. Dioxin risk perceptions were analyzed according to values, risk awareness, knowledge, and behavioral preferences. METHODS: A quasi-experimental survey was designed and conducted on individuals from seven experimental groups in Jeonju city, South Korea, including: people living near incineration facilities; people living far from incineration facilities; governmental experts; nongovernmental organization members; office workers in developmental institutes or banks; students who were enrolled in environmental-related classes; and students who were enrolled in business-related classes. RESULTS: The results show variations among groups in values, awareness and behavioral preferences. Particular attention should be given to the result that groups with higher connectedness- to-nature values show higher willingness-to-act (WTA) for risk reduction. Result s can be summarized as follows. First, awareness is associated with one's geographical setting. Second, values and WTA behaviors are related to one's environmental-related education and occupation. Third, values are significantly related to WTA behaviors. CONCLUSIONS: Different cultures, in terms of values or worldview, among groups influence their perceptions of dioxin risk and choices of risk reduction behaviors. It is important to consider values in communicating complicated long-term risk management involving public participation. Further research should be continuously conducted on the effects of multiple dimensions of values on one's WTA for risk reduction behaviors.

Ecological Risk Assessment of Chemicals Migrated from a Recycled Plastic Product

OBJECTIVES: Potential environmental risks caused by chemicals that could be released from a recycled plastic product were assessed using a screening risk assessment procedure for chemicals in recycled products. METHODS: Plastic slope protection blocks manufactured from recycled plastics were chosen as model recycled products. Ecological risks caused by four model chemicals -di-(2-ethylhexyl) phthalate (DEHP), diisononyl phthalate (DINP), cadmium (Cd), and lead (Pb)- were assessed. Two exposure models were built for soil below the block and a hypothetic stream receiving runoff water. Based on the predicted no-effect concentrations for the selected chemicals and exposure scenarios, the allowable leaching rates from and the allowable contents in the recycled plastic blocks were also derived. RESULTS: Environmental risks posed by slope protection blocks were much higher in the soil compartment than in the hypothetic stream. The allowable concentrations in leachate were 1.0x10(-4), 1.2x10(-5), 9.5x10(-3), and 5.3x10(-3) mg/L for DEHP, DINP, Cd, and Pb, respectively. The allowable contents in the recycled products were 5.2x10(-3), 6.0x10(-4), 5.0x10(-1), and 2.7x10(-1) mg/kg for DEHP, DINP, Cd, and Pb, respectively. CONCLUSIONS: A systematic ecological risk assessment approach for slope protection blocks would be useful for regulatory decisions for setting the allowable emission rates of chemical contaminants, although the method needs refinement.

Quantitative Assessment Technology of Small Animal Myocardial Infarction PET Image Using Gaussian Mixture Model / 의학물리

Nuclear medicine images (SPECT, PET) were widely used tool for assessment of myocardial viability and perfusion. However it had difficult to define accurate myocardial infarct region. The purpose of this study was to investigate methodological approach for automatic measurement of rat myocardial infarct size using polar map with adaptive threshold. Rat myocardial infarction model was induced by ligation of the left circumflex artery. PET images were obtained after intravenous injection of 37 MBq 18F-FDG. After 60 min uptake, each animal was scanned for 20 min with ECG gating. PET data were reconstructed using ordered subset expectation maximization (OSEM) 2D. To automatically make the myocardial contour and generate polar map, we used QGS software (Cedars-Sinai Medical Center). The reference infarct size was defined by infarction area percentage of the total left myocardium using TTC staining. We used three threshold methods (predefined threshold, Otsu and Multi Gaussian mixture model; MGMM). Predefined threshold method was commonly used in other studies. We applied threshold value form 10% to 90% in step of 10%. Otsu algorithm calculated threshold with the maximum between class variance. MGMM method estimated the distribution of image intensity using multiple Gaussian mixture models (MGMM2, em leader MGMM5) and calculated adaptive threshold. The infarct size in polar map was calculated as the percentage of lower threshold area in polar map from the total polar map area. The measured infarct size using different threshold methods was evaluated by comparison with reference infarct size. The mean difference between with polar map defect size by predefined thresholds (20%, 30%, and 40%) and reference infarct size were 7.04+/-3.44%, 3.87+/-2.09% and 2.15+/-2.07%, respectively. Otsu verse reference infarct size was 3.56+/-4.16%. MGMM methods verse reference infarct size was 2.29+/-1.94%. The predefined threshold (30%) showed the smallest mean difference with reference infarct size. However, MGMM was more accurate than predefined threshold in under 10% reference infarct size case (MGMM: 0.006%, predefined threshold: 0.59%). In this study, we was to evaluate myocardial infarct size in polar map using multiple Gaussian mixture model. MGMM method was provide adaptive threshold in each subject and will be a useful for automatic measurement of infarct size.

Performance Measurement of Siemens Inveon PET Scanner for Small Animal Imaging / 의학물리

Inveon PET is a recently developed preclinical PET system for small animal. This study was conducted to measure the performance of Inveon PET as recommended by the NEMA NU 4-2008. We measured the spatial resolution, the sensitivity, the scatter fraction and the NECR using a F-18 source. A 3.432 ns coincidence window was used. A 1 mm3 sized F-18 point source was used for the measurement of spatial resolution within an energy window of 350~625 keV. PET acquisition was performed to obtain the spatial resolution from the center to the 5 cm offset toward the edge of the transverse FOV. Sensitivity, scatter fraction, and NECR were measured within an energy window of 350~750 keV. For measuring the sensitivity, a F-18 line source (length: 12.7 cm) was used with concentric 5 aluminum tubes. For the acquisition of the scatter fraction and the NECR, two NEMA scatter phantoms (rat: 50 mm in diameter, 150 mm in length; mouse: 25 mm in diameter, 70 mm in length) were used and the data for 14 half-lives (25.6 hr) was obtained using the F-18 line source (rat: 316 MBq, mouse: 206 MBq). The spatial resolution of the F-18 point source was 1.53, 1.50 and 2.33 mm in the radial, tangential and axial directions, respectively. The volumetric resolution was 5.43 mm3 in the center. The absolute sensitivity was 6.61%. The peak NECR was 486 kcps @121 MBq (rat phantom), and 1056 kcps @128 MBq (mouse phantom). The values of the scatter fraction were 20.59% and 7.93% in the rat and mouse phantoms, respectively. The performances of the Inveon animal PET scanner were measured in this study. This scanner will be useful for animal imaging.

Cloning and Phylogenetic Analysis of Chitin Synthase Genes from Tricholoma matsutake

Chitin synthases(UDP-N-acetyl-D-glucosamine: chitin 4-beta-N-acetyl-D-glucosaminyl transferase, EC 2.4.1.16) catalyze the synthesis of chitin from UDP-N-acetyl-D-glucosamine. Two zymogenic type of chitin synthase gene(TmCHS1 and TmCHS2) were amplified and its nucleotide sequences were determined. By the amino acid comparison and UPGMA tree grouping, TmChs1 and TmChs2 were classified as class II and class IV chitin synthases respectively. The class II type TmChs1 was grouped with others of Agaricales ectomycorrhizal mushroom. Additionally the phylogenetic tree was well adapted to Hymenomycete previously classified by morphological and physiological characteristics.

A Case of Intrahepatic Cholangiocarcinoma Developed in a Remote Region from the Site of Hepatolithiasis / 대한소화기내시경학회지

An association of hepatolithiasis and cholangiocarcinoma is thought to be rare, with a rate reported to be 2.36%-10%. Most of the cholangiocarcinomas concurrent with intrahepatic stones are found in the vicinity of the hepatolithiasis, and the diagnosis of intrahepatic cholangiocarcinoma in cases with hepatolithiasis is very difficult to detect preoperatively in spite of recent developments in techniques of imaging studies. Recently, the development of cholangiocarcinoma was reportd even after the complete removal of the hepatic stones. Thus, bile stasis and bacterial infecton appear to be important causative factors causing cholangiocarcinoma rather than the stone itself. A rare case is reported on intrahepatic cholangiocarcinoma developed in a remote region from the site of the hepatolithiasis. Therefore, the possible presence of cholangiocarcinoma should always be considered and sought during the diagnosis and treatment of hepatolithiasis.

Validity of the specialized columnar epithelium as a diagnostic criterion of the short segment Barrett's esophagus

OBJECTIVE: In the areas where intestinal metaplasia of the stomach is highly prevalent, diagnosing Barrett's esophagus solely by the presence of specialized columnar epithelium in the distal esophagus may lead to many false positive diagnoses. The aim of this study was to test validity of the specialized columnar epithelium as a diagnostic criterion of the short segment Barrett's esophagus in Korea. METHODS: During routine gastroscopy, the length of columnar-lined esophagus was measured and biopsy samples were taken from the mucosa immediately distal to the squamocolumnar junction. Under light microscopy, alcian blue-positive cells were identified. RESULTS: Prevalence of the specialized columnar epithelium in cases without the columnar-lined esophagus and with the short segment columnar-lined esophagus were 57.1% and 31.2%, respectively (P = 0.0281). The specialized columnar epithelium is frequently seen around the cardia in Koreans with or without the columnar-lined esophagus. CONCLUSION: Simple presence of the specialized columnar epithelium is not a valid criterion for a diagnosis of Barrett's esophagus. We propose that both the short segment Barrett's esophagus and the goblet cell metaplasia of the cardia might be grouped together under a title of "the specialized columnar epithelium around the gastroesophageal junction" as a potential preceding condition of adenocarcinoma around the cardia.

Prediction and Management of Choledocholithiasis in Patients Undergoing Laparoscopic Cholecystectomy due to Cholelithiasis / 대한소화기내시경학회지

BACKGROUND/AIMS: Endoscopic retrograde cholangiopancreatography(ERCP) or operative cholangiography is the procedure to demonstrate and remove stones of the biliary tree in patients undergoing laparoscopic cholecystectomy(LC) due to cholelithiasis. However, ERCP or operative cholangiography is an invasive procedure. The next question then is when and for what indication should ERCP or operative cholangiography be performed. The aims of this study were to assess whether prediction of common bile duct(CBD) stones by the noninvasive method such as liver function test and/or clinical findings is possible, and to investigate which method is more adequate for removal of CBD stones found on ERCP or operative cholangiography. METHODS: A total 207 patients with symptomatic cholelithiasis scheduled for LC were enrolled from September 1993 to August 1996. Patients who were already found to have either extrahepatic or intrahepatic biliary stones on sonogram were excluded. Patients were classified into risk group and non-risk group. Patients who belong to the risk group were those having CBD dilatation by ultrasonography, history of jaundice or cholangitis, gallstone pancreatitis, or elevated transaminases. RESULTS: 54 cases were confirmed to have CBD stones by preoperative ERCP(49 cases) and operative cholangiography(5 cases). Detection rate of CBD stones in risk group was 26.8%(22.2% in CBD dilatation, 50.0% in jaundice, 42.9% in history of cholangitis, and 0% in history gallstone pancreatitis or elevated transaminase). Detection rate of CBD stones in non-risk group was 7.7%. All of 12 patients who had CBD stones were successfully removed(10 with preoperative endoscopic removal, 1 with postoperative endoscopic removal, and 1 with CBD exploration). CONCLUSIONS: Jaundice or cholangitis need the preoperative ERCP and, if stones are found, they can be revoved endoscopically. CBD dilatation may be an indication for operative cholangiography rather than preoperative ERCP, and, if CBD stones were found, they can be revoved by laparoscopic CBD exploration or postoperative ERCP. But history of gallstone pancreatitis, elevated transaminases, or patients with no risk factors may not need preoperative ERCP or operative cholangiography considering the cost-effectiveness or possible morbidity.

The Efficacy and Safety of Needle-Knife Papillotomy for Endoscopic Sphincterotomy and Cholangiography / 대한소화기내시경학회지

BACKGROUND: Conventional endoscopic sphincterotomy with papillotome(CES) is an established method of management for patients with biliary obstruction from various causes. However, an alternative treatment to CES must be considered when antecedent cholangiagraphy is unsuccessful or when cannulatian with the conventional papillotome fails. The needle-knife papillotomy(NKP) is one of the alternative methods to CES. Recently, it has been suggested that NKP can be used to achieve diagnostic cholangiography. But NKP is controversial because results from studies assessing its efficacy and safety are conflicting. The current study was undertaken to assess retrospectively the efficacy and safety of NKP and CES. METHODS: All enrolled patients(CES group 113, NKP group 105) underwent ERCP between September 1993 and August 1996 at Korea Univeisity Guro Hospital. NKP for cannulation was used only when biliary tract disease was suspected but deep canulation failed inspite of several attempts. The efficacy and safety of NKP and CES were evaluated according to the rate of success of performing purposes(removal of common bile duct stones, inser tion of endoscopic nasobiliary drainage or endoprosthesis, treatment of sphincter of Oddi dysfunction, and cannulation) and complications(bleeding, perforation, pancreatitis). RESULTS: 1. Overall success rates of performing purposes were 92.9% in CES group(removal of common bile duct stones 95.2%, insertion of endoscopic nasobiliary drainage or endoprosthesis 84.6%, treatment of sphincter of Oddi dysfunction 100%) and 80.0% in NKP group(removal of common bile duct stone 86.7%, insertion of endoscopic nasobiliary drainage or endoprosthesis 80.6%, treatment of SO dysfunction 100%, cannulation 70.6%). The success rate of CES was significantly higher than that of NKP(p=0.04). 2. The morbidity rate of NKP was 10.5%(8 bleeding cases, 1 perforation case, 2 pancreatitis cases) but was not significantly different from that of rate for CES 8.0%(9 bleeding dases). 19 patients with complications recovered uneventfully with conservative treatment. Only 1 patient(ampullary carcinoma) undertwent operation due to severe bleeding after NKP. There was no procedure-related mortality in both groups. CONCLUSION: NKP is an effective endoscopic tool allowing successful endoscopic sphincterotomy when conventional technique fails. And, in carefully selelected cases, NKP is a useful aid for a successful diagnostic cholangiograph.

Two Cases of Primary Sclerosing Cholangitis / 대한소화기내시경학회지

Prirnary sclerosing cholangitis, a chronic progressive cholestatic hepatobiliary disorder of unknown etiology, is characterized by inflammation, scarring and obliteration of bile duct leading to biliary cirrhosis and liver failure. Because histologic finding has only a limited role in the diagnosis, the gold standard for establishing the diagnosis is cholangiographic demonstration of typical diffuse biliary stricutre or beading. The natural history is extremely variable. We report two cases of primary sclerosing cholangitis diagnosed by repeated endoscopic retrograde cholangiographies. They were followed up for 7 and 2 years, respectively.

A Case of Adenoma of the Common Bile Duct Originating at the Cystic Duct Opening / 대한소화기내시경학회지

Adenoma is a benign epithelial lesion with malignant potential and can be found at any site of the gastrointestinal tract. Adenoma of the common bile duct is a rare and unusual cause of bile duct obstruction. We report a case of tubulovillous adenoma of the common bile duct at the cystic duct opening. A 1.8X1.2X1 cm sized, round and lobulated mass was noted on abdominal sonogram, CT scan and endoscopic retrograde cholangiogram, and it was confirmed and treated by surgical resection.

A Case of Tuberculous Lymphadenitis Causing Obstructive Jaundice / 대한소화기내시경학회지

Obstructive disorders of the biliary trees include occlusions of the bile duct lumen by stones, intrinsic disorders of the bile ducts, and extrinsic compressions. The most common biliary cause of obstructive jaundice is the presence of stones. Intrinsic disorders of the bile ducts may be inflammatory, infectious, or neoplastic. And significant enlargement of adjacent lymph nodes due to metastatic tumors or lymphoma can occasionally obstruct the extrahepatic bile ducts. But obstructive jaundice produced by periportal tuberculous lymphadenitis with no evidence of pulmonary tuberculosis is very rare. We report a case of tuberculous lymphadenitis causing obstructive jaundice with a mass around mid common bile duct on abdominal sonogram, CT scan and ERCP, and it was confirmed by an exploratory laparotomy.

A Case of Villous Adenoma of the Ampulla of Vater with Malignant Change / 대한소화기내시경학회지

Ampullary adenoma is a benign neoplasm with malignant potential that arises from the glandular epithelium of the ampulla of Vater. When the tumor is confined to the ampulla, abdominal sonogram and CT scan can show dilatation of the common bile duct or pancreatic duct, but the mass itself may not be seen. And even biopsies are done, the confirmation of malignant change is frequently missed, and it may be impossible to assess the presence of carcinoma in situ or invasive carcinoma without complete exicision of the lesion. So complete surgical resection is recommended because of extensive growth of the ampullary adenoma and its malignant potential. Recently, we experienced a case of about 0.8 x 1.0 cm sized tumor of the ampulla of Vater that was diagnosed as villous adenoma on endoscopic biopsy, and malignant change was found on resected surgical specimen.