Water quality trend and pollutant load and source analysis of Tamjin River water system.

To systematically manage water quality based on watersheds, it is necessary to understand the characteristics of changes in river water quality. This study used observational data of the Tamjin River water system to analyze changes in water quality due to farming activities during the farming period. Water quality trends were analyzed through a long-term trend analysis. Furthermore, the loads and sources of substances regulated under the total maximum daily load system were evaluated. Biochemical oxygen demand and total phosphorous, water quality factors of the target basin, showed recent increasing trends. Loads increased from April, which corresponded to the non-farming period before farming activities began, and characteristics of pollutant discharged in the basin from farming activities were observed. Pollutant sources were different from those observed in water systems with a high proportion of farming activities, and water quality management measures considering the target basin's characteristics were proposed. The results of this study will serve as logical baseline data for establishing water quality management plans.

Predicting Cyanobacterial Blooms Using Hyperspectral Images in a Regulated River.

Process-based modeling for predicting harmful cyanobacteria is affected by a variety of factors, including the initial conditions, boundary conditions (tributary inflows and atmosphere), and mechanisms related to cyanobacteria growth and death. While the initial conditions do not significantly affect long-term predictions, the initial cyanobacterial distribution in water is particularly important for short-term predictions. Point-based observation data have typically been used for cyanobacteria prediction of initial conditions. These initial conditions are determined through the linear interpolation of point-based observation data and may differ from the actual cyanobacteria distribution. This study presents an optimal method of applying hyperspectral images to establish the Environmental Fluid Dynamics Code-National Institute of Environment Research (EFDC-NIER) model initial conditions. Utilizing hyperspectral images to determine the EFDC-NIER model initial conditions involves four steps that are performed sequentially and automated in MATLAB. The EFDC-NIER model is established using three grid resolution cases for the Changnyeong-Haman weir section of the Nakdong River Basin, where Microcystis dominates during the summer (July to September). The effects of grid resolution on (1) water quality modeling and (2) initial conditions determined using cumulative distribution functions are evaluated. Additionally, the differences in Microcystis values are compared when applying initial conditions using hyperspectral images and point-based evaluation data. Hyperspectral images allow detailed initial conditions to be applied in the EFDC-NIER model based on the plane-unit cyanobacterial information observed in grids, which can reduce uncertainties in water quality (cyanobacteria) modeling.

Pre-operative predictive factors for gallbladder cholesterol polyps using conventional diagnostic imaging.

AIM: To determine the clinical data that might be useful for differentiating benign from malignant gallbladder (GB) polyps by comparing radiological methods, including abdominal ultrasonography (US) and computed tomography (CT) scanning, with postoperative pathology findings. METHODS: Fifty-nine patients underwent laparoscopic cholecystectomy for a GB polyp of around 10 mm. They were divided into two groups, one with cholesterol polyps and the other with non-cholesterol polyps. Clinical features such as gender, age, symptoms, size and number of polyps, the presence of a GB stone, the radiologically measured maximum diameter of the polyp by US and CT scanning, and the measurements of diameter from postoperative pathology were recorded for comparative analysis. RESULTS: Fifteen of the 41 cases with cholesterol polyps (36.6%) were detected with US but not CT scanning, whereas all 18 non-cholesterol polyps were observed using both methods. In the cholesterol polyp group, the maximum measured diameter of the polyp was smaller by CT scan than by US. Consequently, the discrepancy between those two scanning measurements was greater than for the non-cholesterol polyp group. CONCLUSION: The clinical signs indicative of a cholesterol polyp include: (1) a polyp observed by US but not observable by CT scanning, (2) a smaller diameter on the CT scan compared to US, and (3) a discrepancy in its maximum diameter between US and CT measurements. In addition, US and the CT scan had low accuracy in predicting the polyp diameter compared to that determined by postoperative pathology.

Comparison of mass spectrometric analysis and TRUGENE HBV genotyping for monitoring lamivudine resistance in chronic hepatitis B patients.

BACKGROUND: There is an increasing need for the early detection of emerging mutations in the tyrosine-methionine-aspartate-aspartate (YMDD) motif of hepatitis B virus (HBV) DNA polymerase with using sensitive molecular methods. METHODS: We evaluated the usefulness of monitoring lamivudine resistance using a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based assay (the restriction fragment mass polymorphism; RFMP) in comparison with the direct sequencing assay, the TRUGENE ' HBV genotyping kit. We also investigated the treatment responses in relation to the presence of YMDD mutants. The sera from 50 chronic HBVs patients were analysed for the presence of YMDD mutants by performing RFMP and TRUGENE. The results at codons 180 and 204 were compared for 46 patients. RESULTS: The concordance rate between the two assays was 65.2% (30/46). All the discordance corresponded to the detection of additional virus populations by RFMP. Early detection of mutants before viral breakthrough was accomplished by RFMP in two patients. Persistence of very low viraemia was observed in five patients who harboured mutant virus populations. Additional information was provided by TRUGENE in eight patients. CONCLUSIONS: RFMP showed a superior ability for detecting minor mutant virus populations compared with TRUGENE. However, the results of highly sensitive RFMP should be interpreted carefully because lamivudine could be effective despite the presence of mutants. RFMP could be a practical tool in conjunction with regular measurements of the HBV viral load for the early detection of lamivudine resistance and the timely introduction of new antiviral drugs.

The association between increased alanine aminotransferase activity and metabolic factors in nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) has been associated with metabolic disorders, including central obesity, dyslipidema, hypertension, and hyperglycemia. Metabolic syndrome, obesity, and insulin resistance are major risk factors in the pathogenesis of NAFLD. The aim of this study was to identify the relative contribution of the metabolic syndrome, obesity, and insulin resistance to alanine aminotransferase (ALT) activity in NAFLD. A total of 3091 subjects diagnosed with fatty liver by ultrasonography were enrolled. All components of metabolic syndrome criteria, anthropometric parameters, fasting insulin levels, high-sensitivity C-reactive protein (hs-CRP) as an inflammation marker, and ALT were measured in each subject. Homeostasis model assessment--insulin resistance (HOMA-IR) as a measure of insulin resistance and body mass index (BMI) as a measure of obesity were calculated. The prevalence of increased ALT levels (>40 IU/L) was 26.7%. Increased ALT activity was significantly associated with the following characteristics: male sex, young age, increased triglycerides, fasting glucose, fasting insulin, HOMA-IR, hs-CRP, waist circumference, BMI and diastolic blood pressure, and decreased high-density lipoprotein cholesterol (HDL-C). According to the increase in the number of metabolic syndrome components, BMI, HOMA-IR, and hs-CRP, the prevalence and odds ratio for having increased ALT activity were significantly increased. Central obesity, raised triglycerides, reduced HDL-C, and raised fasting glucose were strongly associated with increased ALT activity. In conclusion, a number of metabolic syndrome components, obesity, insulin resistance, and hs-CRP, are strong predictors of increased ALT activity in NAFLD. Central obesity, raised triglycerides, reduced HDL-C, and raised fasting glucose are metabolic syndrome components that contributed to increased ALT activity.

Hyperinsulinemia and the development of nonalcoholic Fatty liver disease in nondiabetic adults.

BACKGROUND: insulin resistance is known to be the most important pathogenic factor in the development of nonalcoholic fatty liver disease. We performed a prospective study to analyze the associations of baseline and changes in fasting insulin levels with future development of nonalcoholic fatty liver disease in nondiabetic adults over a 5-year period. METHODS: this study was performed in 4954 subjects who did not have diabetes or nonalcoholic fatty liver disease and who participated in a health checkup program in both 2003 and 2008. The presence of nonalcoholic fatty liver disease was defined by ultrasonographic examination. Subjects were divided into 4 groups according to the baseline quartiles of fasting insulin and dichotomized fasting insulin levels at baseline and after 5 years: low-low, low-high, high-low, high-high. RESULTS: after 5 years, 644 subjects (13%) developed nonalcoholic fatty liver disease. The odds ratio (OR) for development of nonalcoholic fatty liver disease increased as the quartiles of the baseline fasting insulin levels increased from the first to the fourth quartile (1.00 vs. 0.99, 1.44, 1.65, respectively). The OR for nonalcoholic fatty liver disease was 2.5-fold higher in the high-high group and 1.6-fold higher in the low-high group compared with that of the low-low group. The OR for nonalcoholic fatty liver disease increased as the quartile of changes in fasting insulin level over the 5-year period increased. CONCLUSION: high baseline and continuously increasing fasting insulin levels were the independent determinants for future development of nonalcoholic fatty liver disease during a 5-year follow-up in nondiabetic healthy adults.

Serum adipocyte-specific fatty acid-binding protein is associated with nonalcoholic fatty liver disease in apparently healthy subjects.

Adipocyte-specific fatty acid-binding protein (A-FABP) is a cytoplasmic protein that is expressed in adipocytes and is closely associated with insulin resistance, metabolic syndrome, and Type 2 diabetes. We investigated the relationship between A-FABP as a surrogate marker of metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) in apparently healthy subjects. We assessed clinical and biochemical metabolic parameters and measured serum levels of A-FABP, high-sensitivity C-reactive protein and tumor necrosis factor-α (TNF-α) in 494 subjects who were divided into two groups according to the presence of NAFLD by abdominal ultrasonography. All parameters associated with metabolic syndrome were significantly higher in patients with NAFLD (P<.001). A-FABP showed positive correlation with TNF-α, homeostasis model assessment index of insulin resistance (HOMA-IR), and metabolic syndrome (P<.001) when adjusted for age and sex. The odds ratio for the risk of NAFLD in the highest tertile of A-FABP compared with the lowest tertile was 7.36 (CI 3.80-14.27, P<.001) after adjustment for age and sex; 4.52 (CI 2.22-9.20, P<.001) after adjustment for age, sex, HOMA-IR and metabolic syndrome and 2.86 (CI 1.11-7.35, P<.05) after further adjustment for all metabolic parameters including TNF-α. The serum level of A-FABP was independently associated with NAFLD and showed significant correlation with TNF-α, HOMA-IR, and metabolic syndrome.

Clevudine-induced viral response, associated with continued reduction of HBsAg titer, was durable after the withdrawal of therapy.

BACKGROUND: This study was conducted to evaluate the durability of clevudine-induced viral response after the withdrawal of treatment. METHODS: Patients who showed a complete response [alanine aminotransferase (ALT) normalization and hepatitis B virus (HBV) DNA <4,700 copies/mL for hepatitis B envelope antigen (HBeAg)-negative patients; ALT normalization, HBV DNA <4,700 copies/mL, and HBeAg seroconversion for HBeAg-positive patients] in the previous clevudine phase III trials were followed for an additional 96 weeks without any treatment for hepatitis B. RESULTS: Of the 63 patients in the study cohort, 73% and 35% of the patients had HBV DNA <141,500 and <4,700 copies/mL, respectively, and 75% of the patients had normal ALT at the end of follow-up. HBeAg seroconversion was maintained in 81% of the patients and hepatitis B surface antigen (HBsAg) loss occurred in 3 patients. Continued HBsAg titer decrease (-0.5 log IU/mL) was observed in the sustained viral responders, suggesting the reduction of covalently closed circular DNA in hepatocytes. CONCLUSIONS: The clevudine-induced viral response was durable in the majority of patients for 2 years after the withdrawal of treatment.

Metabolic syndrome is associated with erosive esophagitis.

AIM: To clarify whether insulin resistance and metabolic syndrome are risk factors for erosive esophagitis. METHODS: A case-control study was performed using the database of the Kangbuk Samsung Hospital Medical Screening Center. RESULTS: A total of 1679 cases of erosive esophagitis and 3358 randomly selected controls were included. Metabolic syndrome was diagnosed in 21% of the cases and 12% of the controls (P < 0.001). Multiple logistic regressions confirmed the association between erosive esophagitis and metabolic syndrome (Odds ratio, 1.25; 95% CI, 1.04-1.49). Among the components of metabolic syndrome, increased waist circumference, elevated serum triglyceride levels and hypertension were significant risk factors for erosive esophagitis (all P < 0.01). Furthermore, increased insulin resistance (Odds ratio, 0.91; 95% CI, 0.85-0.98) and fatty liver, as diagnosed by ultrasonography (Odds ratio, 1.39; 95% CI, 1.20-1.60), were also related to erosive esophagitis even after adjustment for a series of confounding factors. CONCLUSION: Metabolic syndrome and increased insulin resistance are associated with an increased risk of developing erosive esophagitis.

Clevudine is highly efficacious in hepatitis B e antigen-negative chronic hepatitis B with durable off-therapy viral suppression.

UNLABELLED: Clevudine is a pyrimidine analog with potent and sustained antiviral activity against HBV. In the present study, we evaluated the safety and efficacy of clevudine 30 mg daily for 24 weeks and assessed the durability of antiviral response for 24 weeks after cessation of dosing in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (e-CHB). We randomized a total of 86 patients (3:1) to receive clevudine 30 mg (n = 63) or placebo (n = 23) daily for 24 weeks. We followed patients for an additional 24 weeks after withdrawal of treatment. The median changes in HBV DNA from baseline were -4.25 and -0.48 log(10) copies/mL at week 24 in the clevudine and placebo groups, respectively (P < 0.0001). Viral suppression in the clevudine group was sustained after withdrawal of therapy, with 3.11 log(10) reduction at week 48. At week 24 and week 48, 92.1% and 16.4% of patients in the clevudine group had undetectable serum HBV DNA levels by Amplicor PCR assay (<300 copies/mL). The proportion of patients who achieved ALT normalization was 74.6% and 33.3% in the clevudine and placebo groups at week 24, respectively (P = 0.0006). ALT normalization in the clevudine group was well-maintained during the post-treatment follow-up period. The incidence of adverse events was similar in the 2 groups. No resistance to clevudine was detected during treatment. CONCLUSION: A 24-week clevudine therapy was well-tolerated and showed potent and sustained antiviral effect without evidence of viral resistance in e-CHB patients. However, treatment for longer than 24 weeks would be needed to achieve durable remission.

Twenty-four-week clevudine therapy showed potent and sustained antiviral activity in HBeAg-positive chronic hepatitis B.

UNLABELLED: Clevudine is a pyrimidine analogue with potent and sustained antiviral activity against HBV. The present study evaluated the safety and efficacy of 30 mg clevudine once daily for 24 weeks and assessed the durable antiviral response for 24 weeks after cessation of dosing. A total of 243 hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients were randomized (3:1) to receive clevudine 30 mg once daily (n=182) or placebo (n=61) for 24 weeks. Patients were followed for a further 24 weeks off therapy. Median serum HBV DNA reductions from baseline at week 24 were 5.10 and 0.27 log10 copies/mL in the clevudine and placebo groups, respectively (P<0.0001). Viral suppression in the clevudine group was sustained off therapy, with 3.73 log10 reduction at week 34 and 2.02 log10 reduction at week 48. At week 24, 59.0% of patients in the clevudine group had undetectable serum HBV DNA levels by Amplicor PCR assay (less than 300 copies/mL). The proportion of patients who achieved normalization of alanine aminotransferase (ALT) levels was 68.2% in the clevudine group and 17.5% in the placebo group at week 24 (P<0.0001). ALT normalization in the clevudine group was well maintained during post-treatment follow-up period. The incidence of adverse events (AEs) was similar between the clevudine group and the placebo group. No resistance to clevudine was detected with 24 weeks of administration of drug. CONCLUSION: A 24-week clevudine therapy was well tolerated and showed potent and sustained antiviral effect without evidence of viral resistance during treatment period in HBeAg-positive chronic hepatitis B.

Relative risks of the metabolic syndrome according to the degree of insulin resistance in apparently healthy Korean adults.

A new simple criterion for diagnosing metabolic syndrome was proposed in the third report of the NCEP (National Cholesterol Education Program). In the present study, we analysed the association between metabolic syndrome and insulin resistance to investigate the effects of the latter on the prevalence of metabolic syndrome based on the new criteria recommended in the ATP (Adult Treatment Panel) III report. A total of 7057 participants (4472 men and 2585 women), who underwent medical screening at the Sungkyunkwan University Kangbuk Samsung Hospital, were investigated. Fasting insulin levels were measured and components of the metabolic syndrome as defined by the ATP III report were determined. We also applied the criteria for abdominal obesity as defined by APC-WC (Asia-Pacific criteria for waist circumference). The prevalence of metabolic syndrome as defined by ATP III was 5.3% (5.0% in men and 5.8% in women) and 8.9% (8.1% in men and 10.3% in women) by APC-WC. The odds ratio for the metabolic syndrome was significantly higher in subjects with higher insulin resistance than in those with lower insulin resistance. The mean levels of HOMA (homoeostatic model assessment) and fasting insulin were significantly higher in those with more of the components of the metabolic syndrome. A high HOMA (> or =2.56) and fasting insulin concentration (> or =9.98 microIU/ml; where IU is international unit) were found to be independent risk factors of the metabolic syndrome by multiple regression analysis after adjusting for age, sex and body mass index (P<0.001). These results show that the metabolic syndrome is significantly correlated with the insulin resistance index, and that appropriate values of HOMA and fasting insulin concentration may serve as a helpful guide for the management of metabolic syndrome.