Glycolipids produced byPseudomonas aeruginosa YPJ-80 were characterized by chromatographic and spectroscopic techniques as a mixture of two rhamnolipids. For recovery of glycolipids from the culture ...broth, various isolation methods including ultrafiltration, adsorption and solvent extraction were compared. Ultrafiltration showed the best results in terms of glycolipids recovery. Further purification for spectroscopic analysis was carried out by adsorption chromatography and preparation thin layer chromatography. From the spectroscopic analysis, such as IR spectroscopy, FAB-MS,^sup 1^H-NMR and^sup 13^C-NMR and hydrolysis analysis, the glycolipids were identified as L-α-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate and 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate. Monorhamnolipid and dirhamnolipid lowered the surface tension of water to 28.1 mN/m and 29.3 mN/m, respectively.PUBLICATION ABSTRACT
Numerous epidemiologic data have documented that chronic infection by hepatitis C virus (HCV) is a major risk factor for the development of hepatocellular carcinoma (HCC). But the molecular mechanism ...underlying these strong epidemiologic associations between HCV and HCC has not be elucidated. We observed the changes of HCV in HCC to investigate the association of HCV with HCC.
We used competitive and quantitative polymerase chain reaction and dideoxy-nucleotide chain termination method to compare HCV titers and sequences of the hypervariable region of E2/NS1 region of four isolates from the HCC and surrounding cirrhotic liver tissues in tow anti-HCV positive patients.
The copy numbers of HCV-RNA were 1 x 10(6) and 4 x 10(6)/gm wet weight of HCC, and 8 x 10(7) and 3.2 x 10(8)/gm wet weight of cirrhotic liver tissues from patient-1 and -2. The sequence differences between HCV RNA in HCC and in cirrhotic liver were two and five nucleotides in patient-1 and in patient-2 respectively. The amino acid sequences were changed in one and two site in each patient.
These findings may suggest the possible etiological role of HCV in carcinogenesis of HCC, but complete sequence analysis of HCV including multiple isolates in the same patient, should be performed in many cases.
This paper presents an approach to developing Real-time Dependable Systems (RDSs) based on a real-time object model. A system development process can be divided into two phases, that is, ...Specification Phase and Construction Phase. In the Specification Phase, especially for an RDS, system requirements are decomposed into a group of Real-Time Objects (RTOs) and appropriate objects are identified by means of a decomposition scheme such as Multi-Dimensional Decomposition (MDD). In the Construction Phase, the identified objects are instantiated and combined. RTO.e, which is an extension of the RTO.k model proposed earlier by Kim and Kopetz (1994), plays the role of a connector and also that of a firewall between the two phases. In this paper, we present design tools that are required in developing RDSs. The tools provide a seamless system implementation method and an information base that can be utilized through the development process.
Glycolipids produced by Pseudomonas aeruginosa YPJ-80 were characterized by chromatographic and spectorscopic techniques as a mixture of two rhamnolipids. For recovery of glycolipids from the culture ...broth, various isolation methods including ultrafiltration, adsorption and solvent extraction were compared. Ultrafiltration showed the best results in terms of glycolipids recovery. Further purification for spectroscopic analysis was carried out by adsorption chromatography and preparative thin layer chromatography. From the spectroscopic analysis, such as IR spectroscopy. FAB-MS, 1H-NMR and 13C-NMR and hydrolysis analysis, the glycolipids were identified as L-${\alpha}$-rhamnopyranosyl-${\beta}$-hydroxydecanoly-${\beta}$-hydroxydecanoate and 2-O-${\alpha}$-L-rhamnopyranosyl-${\alpha}$-L-rhamnopyranosyl-${\beta}$-hydroxydecanoyl-${\beta}$-hydroxydecanoate. Monorhamnolipid and dirhamnolipid lowered the surface tension of water to 28.1 mN/M and 29.3 mN/m, respectively.
The eradication rates of Helicobacter pylori infection have been reported to have decreased over the years due to antibiotics resistance. The aim of this study is to investigate the trend of ...eradication rates of first-line triple therapy for H. pylori over the past 13 year period, and to evaluate factors affecting H. pylori eradication in Daegu and Gyeongsangbuk-do, Korea.
A total of 2,982 patients with H. pylori infection who were treated with either 1 week or 2 weeks first-line therapy (proton pump inhibitor PPI, amoxicillin, and clarithromycin) from January 1999 through December 2011 were included in this study. Data were collected by retrospectively reviewing the medical records.
The overall H. pylori eradication rate was 87.2%. The eradication rates from 1999 to 2011 fluctuated between 78.0% and 95.7%, but no definite evidence of a decreasing tendency was seen over the 13 year period (p=0.113). Furthermore, there was no significant difference in the eradication rate according to the duration of therapy (p=0.592). However, there was a significant difference in the eradication rate among various PPIs (p<0.01).
There was no decreasing trend in the H. pylori eradication rate over the past 13 years in Daegu and Gyeongsangbuk-do, Korea. There also was no difference in the eradication rates depending on duration of therapy. However, a significant difference was noted among various PPIs.
Recent studies suggest that the prevalence of gastroesophageal reflux disease (GERD) is increasing in Korea. However, studies on risk factors for GERD have yielded inconsistent results. The aims of ...this study were to compare clinical features between symptomatic syndromes without esophageal injury (=non-erosive disease NED) and syndromes with esophageal injury (=erosive disease ED), and to determine risk factors associated ED.
A total of 450 subjects who visited gastroenterology clinics of six training hospitals in Daegu from March 2008 to April 2010 were consecutively enrolled. The subjects were asked to complete a questionnaire which inquired about gastroesophageal reflux symptoms. The questionnaire also included questions about smoking, alcohol drinking, consumption of coffee, use of drugs, exercise, and other medical history. The subjects were subdivided into NED and ED groups.
The proportion of subjects in each NED and ED group was 172 (38.2%) and 278 (61.8%). Male gender, smoking, alcohol drinking, consumption of coffee, large waist circumference, infrequent medication of antacids, aspirin and NSAIDs, infrequent and mild GERD symptoms were all significantly associated with ED on univariate analysis. Age, hiatal hernia, diabetes mellitus, body mass index, change in weight during 1 year, and number of typical GERD symptoms were not independent risk factors for ED. However, the association between ED and alcohol drinking, infrequent medication of antacids, mild typical GERD symptoms remained as strong risk factors after adjustments on multivariate logistic analysis.
Independent risk factors associated with ED were alcohol drinking, infrequent medication of antacids and mild typical GERD symptoms.
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