Objective: To investigate the mechanism of antibacterial activity of luteolin (LUT) against methicillin-resistant Staphylococcus aureus (MRSA). Methods: The mechanism of anti-MRSA activity of LUT was analyzed by the viability assay in membrane permeabilizing agent, ATPase inhibitors, and peptidoglycan (PGN) derived from Staphylococcus aureus (S. aureus). Also, transmission electron microscopy was used to monitor survival characteristics and changes in S. aureus morphology. Results: Compared to the LUT alone, the optical density of suspensions treated with the combination of 125 μg/mL Tris and 250 μg/mL N,N'-dicyclohexylcarbodiimide were reduced to 60% and 46% of the control, respectively. PGN (15.6 μg/mL) gradually impeded the activity of LUT, and PGN (62.5 μg/mL) completely blocked the activity of LUT on S. aureus. Conclusions: Increased susceptibility to LUT with the Tris-dicyclohexylcarbodiimide combinations is evident in all tested MRSA isolates. The results indicate LUT synergy in increasing cytoplasmic membrane permeability and inhibiting ATPase. S. aureus PGN directly blocks the antibacterial activity of LUT, suggesting the direct binding of LUT with PGN. These findings may be validated for the development of antibacterial agent for low MRSA resistance.

BACKGROUND: Dialysis patients have impaired host defense mechanisms and frequently require antibiotics for various infective complications. In this study, we investigated whether dialysis patients have greater risk for Clostridium difficile-associated diarrhea (CDAD). METHODS: During the 4-year study period (2004-2008), 85 patients with CDAD were identified based on a retrospective review of C difficile toxin assay or histology records. Nosocomial diarrheal patients without CDAD were considered as controls (n=403). We assessed the association between renal function and the prevalence and clinical outcomes of CDAD. RESULTS: There was a significant difference in the prevalence rate of chronic kidney disease (CKD) between CDAD and non-CDAD patients (P<0.001). Sixteen patients (18.8%) of the CDAD group were treated with dialysis, whereas 21 patients (5.2%) of the non-CDAD group were treated with dialysis. There was a significant association between renal function and CDAD in patients on dialysis [odds ratio (OR)=4.44, 95% confidence interval (CI) 2.19-8.99, P<0.001], but not in patients with CKD stage 3-5 (OR=1.10, 95% CI 0.63-1.92, P=0.73). In multivariate analysis, CKD stage 5D was an independent risk factor for the development of CDAD (OR=13.36, 95% CI 2.94-60.67, P=0.001). CONCLUSION: Our data indicate that dialysis patients might be at a greater risk of developing CDAD, which suggests that particular attention should be provided to CDAD when antibiotic treatment is administered to dialysis patients.
Anti-Bacterial Agents ; Clostridium ; Clostridium difficile ; Defense Mechanisms ; Dialysis ; Diarrhea ; Humans ; Multivariate Analysis ; Prevalence ; Renal Insufficiency, Chronic ; Retrospective Studies ; Risk Factors

BACKGROUND: Dialysis patients have impaired host defense mechanisms and frequently require antibiotics for various infective complications. In this study, we investigated whether dialysis patients have greater risk for Clostridium difficile-associated diarrhea (CDAD). METHODS: During the 4-year study period (2004-2008), 85 patients with CDAD were identified based on a retrospective review of C difficile toxin assay or histology records. Nosocomial diarrheal patients without CDAD were considered as controls (n=403). We assessed the association between renal function and the prevalence and clinical outcomes of CDAD. RESULTS: There was a significant difference in the prevalence rate of chronic kidney disease (CKD) between CDAD and non-CDAD patients (P<0.001). Sixteen patients (18.8%) of the CDAD group were treated with dialysis, whereas 21 patients (5.2%) of the non-CDAD group were treated with dialysis. There was a significant association between renal function and CDAD in patients on dialysis [odds ratio (OR)=4.44, 95% confidence interval (CI) 2.19-8.99, P<0.001], but not in patients with CKD stage 3-5 (OR=1.10, 95% CI 0.63-1.92, P=0.73). In multivariate analysis, CKD stage 5D was an independent risk factor for the development of CDAD (OR=13.36, 95% CI 2.94-60.67, P=0.001). CONCLUSION: Our data indicate that dialysis patients might be at a greater risk of developing CDAD, which suggests that particular attention should be provided to CDAD when antibiotic treatment is administered to dialysis patients.
Anti-Bacterial Agents ; Clostridium ; Clostridium difficile ; Defense Mechanisms ; Dialysis ; Diarrhea ; Humans ; Multivariate Analysis ; Prevalence ; Renal Insufficiency, Chronic ; Retrospective Studies ; Risk Factors

BACKGROUND/AIMS: The meaning of specialized intestinal metaplasia (SIM) in the diagnosis of Barrett's esophagus (BE) is not clear. This study was designed to determine the clinical significance of SIM in the diagnosis of Barrett's esophagus. MATERIALS AND METHODS: Biopsies were taken from 601 subjects with endoscopically suspected columnar-lined esophagus. Under light microscopy with Alcian-blue stain, SIM was identified. Demographic characteristics, gastroesophageal (GE) reflux symptoms and endoscopic findings were compared between the SIM-present group and the SIM-absent group. RESULTS: Among 601 subjects, 184 (30.6%) were confirmed by pathology to have SIM. Age over 40 years (P<0.001) and a medication history of proton pump inhibitor or H2 blocker were found more frequently in the SIM-present group (P=0.01) than in the SIM-absent group. Any of 7 GE reflux symptoms (heartburn, acid regurgitation, chest pain, hoarseness, globus sensation, cough and epigastric soreness) were more frequent in the SIM-present group than SIM-absent group (P<0.001). Specifically, heartburn, chest pain and cough were significantly more common in the SIM-present group. There was no clinically significant difference associated with endoscopic findings or other clinical characteristics. CONCLUSIONS: When subjects with endoscopically suspected BE are analyzed based on the presence or absence of SIM, the SIM-present group was significantly associated with GE reflux symptoms suggestive of frequent GE reflux. However, the presence of SIM did not correlate with endoscopic findings.
Barrett Esophagus ; Biopsy ; Chest Pain ; Cough ; Esophagus ; Gastroesophageal Reflux ; Heartburn ; Hoarseness ; Light ; Metaplasia ; Microscopy ; Prospective Studies ; Proton Pumps ; Sensation

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms

BACKGROUND/AIMS: Chronic gastritis is a common finding during endoscopy and it is very important to describe it correctly. This study was designed to evaluate the distribution of endoscopic gastritis and the differences according to age, sex or area. MATERIALS AND METHODS: A clinical analysis was conducted on 25,536 subjects who had undergone an upper endoscopy for routine health check-up. Endoscopic gastritis was classified into four types, superficial gastritis, erosive gastritis, atrophic gastritis and intestinal metaplasia. The distribution of the four types of gastritis was evaluated according to sex, age and area. RESULTS: 51.6% of the patients had experienced at least one of the symptoms (epigastric pain or discomfort, soarness, dyspepsia, abdominal pain) on at least a few occasions during the previous year. The incidence of normal gastric finding was 3,593 (14.1%). 21,943 (85.9%) subjects have at least more than one of endoscopic gastritis. The number of cases with superficial gastritis was 7,983 (31.3%), erosive gastritis 6,054 (23.7%), atrophic gastritis 6,918 (27.1%), and intestinal metaplasia 1,181 (7.1%). Erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men than women (P<0.001) and in the older age group (> or =60 years) than younger age group (P<0.001). CONCLUSIONS: The prevalence of endoscopic gastritis was very common, 85.9%. In addition, erosive gastritis, atrophic gastritis and intestinal metaplasia were more frequent in men and in the older age group, which is similar to gastric cancer or peptic ulcer. Cautious regular endoscopic follow-up might be necessary regardless of gastrointestinal symptoms in Korea.
Dyspepsia ; Endoscopy ; Female ; Gastritis ; Gastritis, Atrophic ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Male ; Metaplasia ; Peptic Ulcer ; Prevalence ; Stomach Neoplasms

PURPOSE: Systemic anticoagulation, usually with heparin, is required to prevent thrombosis in the blood circuit of hemodialysis. In patients at high bleeding risk, strategies to minimize the bleeding risk include heparin-free or regional anticoagulation methods. Nafamostat mesilate with conventional dose (35 mg/hr) has been used for this purpose. But it is an expensive anticoagulant to use conveniently for the dialysis therapy. Application of low-dose nafamostat mesilate has almost never been tried yet on hemodiaysis management. In this study, we examined the effect of low-dose nafamostat mesilate compared to heparin-free in hemodialysis patients with high risk of bleeding. METHODS: The current study was conducted on 35 hemodialysis patients with high bleeding risk (on-going bleeding, hemorrhage, surgery or severe thrombocytopenia). In the low-dose nafamostat group (n=17, mean age: 59+/-15 years), 238 sessions were performed with continuous infusion of nafamostat mesilate (12.5 mg/hr). In the control group with saline-flushing no heparin methods (n=18, mean age: 57+/-17 years), 247 sessions were analyzed. RESULTS: No significant differences were found in baseline characteristics between the low-dose nafamostat group and the saline group. In the progress of bleeding complications, there were no significant differences between the two groups (11.8% vs. 11.1%). In saline group, however, massive clotting occurred in 44.5 per 1000 sessions, while it occurred in 4.2 per 1000 sessions in the low-dose nafamostat group (p=0.006). CONCLUSION: In patients at high bleeding risk, low-dose nafamostat mesilat can be used as an inexpensive, effective, and safe anticoagulant for hemodialysis.
Dialysis ; Guanidines ; Hemorrhage ; Heparin ; Humans ; Mesylates ; Renal Dialysis ; Thrombosis

PURPOSE: Pulmonary hypertension can occur from diverse etiologies. It was reported that pulmonary hypertension also complicated dialysis patents, but the exact mechanisms were not determined. The aim of this study was to evaluate the prevalence and risk factors of pulmonary hypertension in maintenance hemodialysis patients. In addition, we studied the relationship between pulmonary hypertension and arteriovenous access. METHODS: Fifty-nine chronic hemodialysis patients underwent clinical evaluation. Pulmonary artery pressure (PAP) was estimated by Doppler echocardiography. Pulmonary hypertension was defined as PAP > or =35 mmHg. RESULTS: Mean PAP value of subjects was 39.3+/-13.2 mmHg. Pulmonary hypertension was found in 31 (53%) of patients receiving hemodialysis (49.0+/-10.6 mmHg; range 37 to 84 mmHg). Clinical and biochemical parameters did not differ significantly between patients with pulmonary hypertension and without pulmonary hypertension. In 19 patients, PAP was elevated from 27.8+/-10.2 mmHg to 41.8+/-11.9 mmHg (p<0.001) after onset of hemodialysis via arteriovenous fistula. And pulmonary hypertension developed in 12 of 15 patients with normal PAP after onset of hemodialysis treatment. CONCLUSION: The prevalence of pulmonary hypertension was high, and hemodialysis via arteriovenous access may be involved in the development of pulmonary hypertension.
Arteriovenous Fistula ; Dialysis ; Echocardiography, Doppler ; Humans ; Hypertension ; Hypertension, Pulmonary ; Kidney Failure, Chronic ; Prevalence ; Pulmonary Artery ; Renal Dialysis ; Risk Factors

PURPOSE: To evaluate the incidence and clinical features of age-related macular degeneration (AMD) in Korea. METHODS: Web-based (www.armd-nova.or.kr) registration was conducted for AMD patients aged 50 or more who were newly diagnosed by retinal specialists in Korea from August 20, 2005 to August 20, 2006. Patient data including ophthalmologic examination, fundus photography, fluorescein angiogram and/or indocyanin green angiogram (ICG), past medical history, behavioral habit, combined systemic diseases were up-loaded. RESULTS: Among finally enrolled 1,141 newly diagnosed AMD patients, 690 patients (60.5%) were male and 451 patients (39.5%) were female. The average age of AMD patients was 69.7+/-8.0. Early AMD was observed in 190 patients and 951 patients had late AMD. Classic choroidal neovascular membrane (CNVM) was observed in 18.6% of exudative AMD patients and 63.4 % had occult CNVM. Subfoveal CNVM was observed in 80.4% of the patients with CNVM. Among the 580 exudative AMD eyes that performed indocyanin green angiography (ICG), 184 eyes (31.7%) had polypoidal choroidal vasculopathy (PCV) and 36 eyes (6.2%) showed retinal angiomatous proliferation (RAP). Age, male gender, smoking, diabetes and hypertension significantly increased the risk of the AMD among Koreans. CONCLUSIONS: Because of the low rate of participation by retinal specialists, definite incidence of AMD was not obtainable. However, the estimated 1-year AMD incidence in the Pusan area of Korea is at least 0.4%. In contrast to Western people, 31.7% of exudative AMD cases were revealed to be PCV and 6.2% were revealed to be RAP. This discrepancy between ethnic groups should be considered in the diagnosis and treatment modality selection of Korean AMD patients.
Aged ; Angiography ; Choroid ; Ethnic Groups ; Eye ; Female ; Fluorescein ; Humans ; Hypertension ; Incidence ; Korea ; Macular Degeneration ; Male ; Membranes ; Photography ; Retinaldehyde ; Smoke ; Smoking ; Specialization

BACKGROUND/AIMS: Vascular access dysfunction is an important cause of morbidity and mortality in hemodialysis (HD) patients. Recent studies have shown that a klotho gene mutation is related to endothelial dysfunction, thrombosis, and arteriosclerosis, which are regarded as causes of vascular access dysfunction. We investigated the relationship between the klotho G-395A polymorphism and early dysfunction in vascular access in HD patients. METHODS: Patients who underwent vascular access operations between 1999 and 2002 were enrolled (n=126). Genotyping was performed by allelic discrimination using a 5'-nuclease polymerase chain reaction assay. Clinical data that could be relevant to access dysfunction were obtained from medical records. Early dysfunction of vascular access was defined as the need for any angioplastic or surgical intervention to correct or replace a poorly or nonfunctioning vascular access within 1 year and at least 8 weeks after initial access placement. RESULTS: Of the 126 patients, the genotype frequency of G-395A was 72.2% for GG (n=91), 24.6% for GA (n=31), and 3.2% for AA (n=4), and the frequency of minor allele was 0.155. Clinical data were similar between the two groups, divided according to the status of the A allele. Early dysfunction occurred in 34 (27.0%) of patients, but it occurred at a significantly higher rate in A allele carriers (45.7%, 16/35) than in noncarriers (19.8%, 18/91; p=0.003). CONCLUSIONS: Our results suggest that the klotho G-395A polymorphism could be a risk factor for early dysfunction of vascular access in HD patients.
Aged ; *Arteriovenous Shunt, Surgical ; Catheters, Indwelling ; Cohort Studies ; Female ; Glucuronidase/*genetics ; Humans ; Kidney Failure, Chronic/complications/*genetics/therapy ; Male ; Middle Aged ; Polymorphism, Genetic/*genetics ; Promoter Regions, Genetic/genetics ; *Renal Dialysis ; Vascular Diseases/complications/genetics ; Vascular Patency/*genetics