BACKGROUND: The present study was aimed at investigating whether there is a mechanism exerted by endogenous nitric oxide(NO) in the regulation of aquaporin(AQP) water channels in the kidney. METHODS: Male Sprague-Dawley rats were treated with N(G)-nitro-L-arginine methyl ester(L-NAME, 40 mg/L drinking water) to inhibit the endogenous generation of nitric oxide. Four weeks later, total abundance and shuttling of AQP2 proteins were determined in different regions of the kidney. RESULTS: Chronic inhibition of NO synthesis increased the expression of AQP2 channels in cortex, outer medulla, and inner medulla of the kidney. The AQP2 shuttling was not significantly altered, as evidenced by an unaltered ratio of AQP2 expression in the membrane fraction versus that in the cytoplasmic fraction. CONCLUSION: It is suggested that endogenous NO activity plays a tonic inhibitory role in the expression of AQP2 channels in the kidney.
Animals ; Aquaporin 2* ; Aquaporins* ; Cytoplasm ; Drinking ; Humans ; Kidney* ; Male ; Membranes ; Nitric Oxide* ; Rats* ; Rats, Sprague-Dawley

OBJECTIVE: Recent researches suggest that trans,trans-muconic acid (t,t-MA) would be an adequate metabolic biomarker for low-level benzene exposure. Few study have investigated the association between the t,t-MA and platelet count, and this is the primary aim of this study. METHODS: From May 2004 to June 2004, 326 chemical factory workers took part in a questionnaire survey and they underwent urinary t,t-MA and CBC assessment. The questionnaire covered general aspects of health and the occupational and smoking histories. Statistical analyses of outcomes were performed using SPSS 14.0 for Windows. RESULTS: The subjects' urinary t,t-MA concentration (geometric mean and geometric standard deviation) was 0.28 mg/g creatinine (2.62). No significant differences between different occupations among the chemical workers were found. The urinary t,t-MA concentrations in the smokers and non-smokers were 0.32 mg/g creatinine (2.44) and 0.25 mg/g creatinine (2.77) respectively, and the difference was statistically significant (p<0.05). There was no significant difference in the platelet count based on occupation and the smoking history. There was significant correlation between log(platelet) and log(t,t-MA)(r=-0.116 p=0.039). The regression equation log(platelet) = -0.002xAge + [-0.029xlog(t,t-MA)] + 2.436, R2=0.032, was calculated from linear regression analysis with log(platelet) as the dependent variable. Cross-tabulation between 2 subgroups that were divided by the 90-percentile level of the t,t-MA (0.819 mg/g creatinine), and 2 subgroups that were divided by the 10-percentile level of the platelet count (175,000) was conducted. Higher distribution in subgroup with platelet count below 175,000 was demonstrated in the subgroup with a urinary t,t-MA above the 90-percentile, with an odds ratio of 3.01. CONCLUSIONS: The study may be limited by not taking into account factors such as smoking quantity and sorbic acid, which may confound urinary the t,t-MA concentration as well as medication and infection that may affect the platelet count. Yet it is meaningful that the correlation between the urinary t,t-MA concentration and the platelet count was found through linear regression analysis and the chi-square test, and further, this outcome may be used as a basis for a study to establish the acceptable limit of urinary t,t-MA in Korea.
Benzene ; Blood Platelets ; Creatinine ; Korea ; Linear Models ; Occupations ; Odds Ratio ; Platelet Count ; Questionnaires ; Smoke ; Smoking ; Sorbic Acid

OBJECTIVES: Accurate diagnosis of the mechanism and origin site of paroxysmal supraventricular tachycardia(PSVT) can be made using electrophysiologic study(EPS). Recently, radiofrequency catheter ablation technique has been introduced and widely used for the definitive treatment of various forms of PSVT, thereby precise determination of the mechanism of PSVT can be possible. It has been known that atrioventricular reentry tachycardia (AVRT) using concealed bypass tract is more frequent than atrioventricular nodal reentry tachycardia (AVNRT) in Korea. But it is not certain that those studies represent actual distribution of PSVT in Korea. This study was designed to determine the mechanism and clinical characteristics of PSVT in Korea. METHODS: We investigated 136patients in whom electrophysiolosic study was performed from October 1992 through October 1994 at the Chonnam National University Hospital, the only tertiary referral center of the Kwangju-Chonnam area of Korea. RESULTS: 1) The electrophysiologic mechanism of PSVT was AVNRT in 44patients(32.4%), WPW syndrome in 46(33.8%), AVRT using concealed bypass tract in 40(29.4%), sinoatrial nodal reentry tachycardia (SANRT) in 4(2.9%), and automatic atrial tachycardia(AAT) in 2(1.5%), ensuing that AVNRT is most common mechanism of PSVT with no preexcitation during sinus rhythm. 2) Male is more frequent than female in AVNRT, WPW syndrome, and AVRT, which was most prominent in WPW syndrome. 3) The first episode of symptom occured at the age of 34.9 +/- 17.3 years in AVNRT, 25.5 +/- 13.3 years in WPW and 26.3 +/- 15.0 years in AVRT(p<0.05). There was no significant difference in the duration of symptom. The tachycardia rate in WPW syndrome was 183.6 +/- 23.9 per minute and AVRT was 186.7 +/- 38.0 per minute, which were faster than that of AVNRT(161.7 +/- 28.6/min)(p<0.05). 4) There was no significant difference in the presenting symptoms and in the provocation factors between AVNRT and AVRT. CONCLUSION: AVNIlT is most common mechanism of PSVT with no preexcitation during sinus rhythm, developed at older age than WPW syndorme and AVRT, and had lower tachycardia rate than WPW syndrome and AVRT.
Catheter Ablation ; Diagnosis ; Female ; Humans ; Jeollanam-do ; Korea ; Male ; Tachycardia ; Tachycardia, Atrioventricular Nodal Reentry ; Tachycardia, Sinoatrial Nodal Reentry ; Tachycardia, Supraventricular* ; Tertiary Care Centers ; Wolff-Parkinson-White Syndrome

OBJECTIVES: The main goal of this study was to find the incidence of the dimethylacetamide (DMAc) induced toxic liver injury among workers who were exposed to DMAc for about 5 years in a synthetic fiber factory. METHODS: In our investigation, total 1,021 workers had been exposed to DMAc from 1st February, 2000 to 30th June, 2004. Among them, 24 workers who had initial abnormal hepatic enzyme level or was viral hepatitis B carrier were excluded. Finally, 997 DMAc exposed workers were followed up for their incidence of toxic liver injury. To find out DMAc induced toxic liver injury case, we carried out regular examinations including liver enzyme tests such as AST and ALT. RESULTS: We followed up 997 workers and among them 72 cases coincided with our case definition. Incidence density method was 6.05 per 100 person-year. and, a cumulative incidence by life table method was 0.0965 within a year. The incidence of the DMAc-induced toxic liver injury peaked at 4 to 5 in weeks after employment. There was no toxic liver injury case within second week after exposure to DMAc. Five new cases developed in 2th to 3th week, 25 cases in 4th to 5th week, 14 cases in 6th to 7th week, 12 cases in 8th to 9th week, 5 cases in 10th to 11th week, 4 cases in 12th to 13th week, 4 cases in 14th to 15th week, 1 case in 16th to 17th week, 1 case in 30th to 31th week, and there was one case in 48th to 49th week. CONCLUSIONS: The incidence rate of toxic liver injury was considerably high during the 1st year after a worker is placed. So it is needed to take careful monitoring of hepatic enzyme level for newly exposed worker.
Employment ; Hepatitis B ; Incidence* ; Life Tables ; Liver*

Floating thrombi in the aortic arch are very rare, and often go under-diagnosed. Herein, a case of an 8-cm long thrombus in the aortic arch is reported. It was a floating, highly mobile thrombus attached to the atherosclerotic plaque in the proximal aortic arch. The patient was a 59-year-old woman with a history of hypertension. The thrombus was operatively removed, with a favorable outcome.
Aorta, Thoracic* ; Arteriosclerosis ; Female ; Humans ; Hypertension ; Middle Aged ; Plaque, Atherosclerotic ; Thrombosis*

BACKGROUND: Chronic heart failure (HF) is a leading cause of morbidity and mortality in industrialized countries. Raised resting heart rate (HR) is a marker of cardiovascular risk in general population, as well as in patients with hypertension and coronary artery disease. We studied the association between HR and cardiovascular events in patients with Cardiac Insufficiency of Various Origin in Jeonbuk (CION-J) registry. METHODS: CION-J registry was a multicenter, prospective database for chronic HF. From January 2010 to December 2010, 356 HF patients who clinically stabilized at least 2 weeks were analyzed. According to resting HR, the patients divided into the tertile (lower tertile < 70/min, n = 129; middle tertile 70-80/min, n = 114; upper tertile > 80/min, n = 113). Clinical outcomes during 6-month period were compared by resting HR. RESULTS: Patients with upper tertile revealed higher New York Heart Association (NYHA) class than in those with lower tertile. From the lower to the upper tertile, the incidence of composite events of death, non-fatal myocardial infarction, ischemic stroke, and hospitalization for HF were increased(3.1%, 4.4%, 16.8%, respectively; p < 0.001). Patients with upper tertile had a higher predictive value for the incidence of death (hazard ratio, 5.8; p = 0.036) and hospitalization for HF (hazard ratio, 6.4; p < 0.001) than in those with middle and lower tertile. In multivariate analysis, NYHA class III/IV, resting HR > 80/min, and ejection fraction < 35% were independent predictors of adverse events. CONCLUSIONS: High resting HR (> 80/min) is a prognostic factor in chronic HF. Optimal treatment to reduce HR should be emphasized to improve prognosis of HF.
Coronary Artery Disease ; Developed Countries ; Heart ; Heart Failure ; Heart Rate ; Hospitalization ; Humans ; Hypertension ; Incidence ; Multivariate Analysis ; Myocardial Infarction ; New York ; Prognosis ; Prospective Studies ; Stroke

OBJECTIVES: Area-based occupational disease surveillance in Kumi (KODS) was used to collect data on occupational diseases. The data was used to estimate the magnitude of the diseases, to analyze for their characteristics, and to find links for their intervention and prevention. METHODS: Since January 2001, occupational physicians and nurses in Occupational Health Service (OHS)have reported six major occupational diseases; occupational musculoskeletal disorders of the upper extremities(MSDUE), occupational dermatoses, toxic hepatitis, occupational asthma (OA), hand-arm vibration syndrome(HAVS), and occupational cancer. For the respective diseases, a reporting sheet and operational diagnostic criteria were developed by the KODS. An analysis of the KODS data, collected over a certain period, was compared with data from the Korea Labor Workers Corporation (KLWC) and the Specific Health Examination (SHE), and the incidence rates of the diseases estimated. RESULTS: Between Jan 2001 and Apr 2002, 287 cases of the six major occupational disease were reported. Of these, there were 132 (46.0%), 100 (34.8%), 34 (11.8%), 16 (5.6%), and 5 (1.7%), cases of MSDUE, occupational dermatoses, toxic hepatitis, OA, and HAVS, respectively. But, there were no cases of occupational cancer. 33 (11.5%) of the incidence were reported via the OHS, 206 (71.7%) from health checkups, and the other 48(16.8%) from other routes. The synthetic fibers and electronic components manufacturing industries accounted for the greatest number of reported cases. With respect to occupation, the greatest numbers of incidence were reported from the elementary occupations, textile workers, assemblers, and cooks and food services worker, in that order. Of the MSDUE cases, carpal tunnel syndrome and epicondylitis were the two most common diseases. Most of the occupational dermatoses were due to contact dermatitis, with organic solvents (59%), nickel (6%), and epoxy resin (5%) accounting for the majority of these cases. All cases of toxic hepatitis were induced by dimethylformamide or dimethylacetamide, which were reported by a unique monitoring system. During same period, there were no cases claimed by workers to the KLWC, and only three cases from SHE, were identified. Using data from workers' number and surveillance, the annual incidences of MSDUE, dermatoses, hepatitis, OA, and HAVS, per 100,000 workers were 63.6, 48.2, 17.9, 7.7, and 2.4, respectively. CONCLUSIONS: These results show that an area-based surveillance system can be very effective for the collection of data on work-related diseases, at least in Kumi.
Asthma, Occupational ; Carpal Tunnel Syndrome ; Dermatitis, Contact ; Dimethylformamide ; Drug-Induced Liver Injury ; Food Services ; Gyeongsangbuk-do* ; Hepatitis ; Incidence ; Korea ; Nickel ; Occupational Diseases ; Occupational Health Services ; Occupations ; Skin Diseases ; Solvents ; Textiles ; Vibration

BACKGROUND AND OBJECTIVES: Angiotensin II receptor blocker (ARB) has emerged as an alternative to angiotensin converting enzyme inhibitor (ACEI) for the treatment of heart failure. This study aimed at comparing the effectiveness and safety of valsartan with ramipril in patients with heart failure, and these patients were hospitalized at Chonnam National University Hospital, Wonkwang University Hospital, Gunsan Medical Center, Presbyterian Medical Center, Seonam University Hospital and Gwangju Christian Hospital. SUBJECTS AND METHODS: Between March 2005 and March 2007, 82 patients (60.5+/-12.4 years, 59 males) who complained of class II to IV dyspnea, according to the New York Heart Association (NYHA) classification, and who had low left ventricular ejection fraction (LVEF) less than 50% were randomly allocated to valsartan or ramipril. After 6 months, the clinical symptoms, vital signs, biochemical tests and echocardiography were compared between the two groups. RESULTS: The NYHA class was improved in both groups (the valsartan group: 2.31+/-0.51 vs. 1.46+/-0.58, p<0.001; the ramipril group: 2.21+/-0.55 vs. 1.61+/-0.50, p<0.001). The incidence of cough, as measured by the cough index, was significantly lower in the valsartan group than in the ramipril group (p=0.045). The LVEF was improved in both groups (the valsartan group: 36.4+/-8.5% vs. 46.9+/-12.9%, p<0.001; the ramipril group: 35.1+/-8.5% vs. 45.3+/-11.2%, p<0.001). The improvements of the left ventricular end-systolic dimension (p=0.754) and end-diastolic dimension (p=0.998) were not different between the two groups. N-terminal Pro-B-type natriuretic peptide level was improved in both groups (the valsartan group: 2619.6+/-4213.5 vs. 995.4+/-2186.0 pg/mL, p=0.012; the ramipril group: 3267.9+/-4320.0 vs. 828.1+/-1232.8 pg/mL, p=0.009), and there was no difference between the groups (p=0.877). CONCLUSION: Both valsartan and ramipril were effective treatments, with relatively low adverse events, in patients with heart failure.
Angiotensins ; Cough ; Dyspnea ; Echocardiography ; Heart ; Heart Failure ; Humans ; Incidence ; New York ; Peptidyl-Dipeptidase A ; Protestantism ; Ramipril ; Receptors, Angiotensin ; Stroke Volume ; Tetrazoles ; Valine ; Ventricular Remodeling ; Vital Signs ; Valsartan