Urinary Concentration Defect and Renal Glycosuria in Cyclosporine-treated Rats

Background@#Urinary concentration impairment is a major feature of cyclosporine nephrotoxicity. @*Methods@#We explored two possible mechanisms that may underlie cyclosporineinduced polyuria; water, and/or osmotic diuresis. Cyclosporine was subcutaneously injected to normal salt-fed Sprague-Dawley rats at a daily dose of 25mg/kg for 2 weeks (Experiment I) and 7.5mg/kg for 6 weeks (Experiment II). @*Results@#In Experiment I, cyclosporine treatment caused an increase in urine volume (2.7±0.5 vs. 10.3±1.13mL/d/100 g BW, p<0.001) and a decrease in urine osmolality (2,831±554 vs. 1,379±478mOsm/kg H2O, p<0.05). Aquaporin-2 (AQP2) protein expression decreased in cyclosporine-treated rat kidneys (cortex, 78±8%, p<0.05; medulla, 80±1%, p<0.05). Experiment II also showed that urine volume was increased by cyclosporine treatment (4.97±0.66 vs. 9.65±1.76mL/d/100 g BW, p<0.05). Whereas urine osmolality was not affected, urinary excretion of osmoles was increased (7.5±0.4 vs. 14.9±1.4mosmoles/d/100 g BW, p<0.005). Notably, urinary excretion of glucose increased in cyclosporine-treated rats (7±1 vs. 10,932±2,462 mg/d/100 g BW, p<0.005) without a significant elevation in plasma glucose. In both Experiment I and II, GLUT2 protein expression in the renal cortex was decreased by cyclosporine treatment (Experiment I, 55±6%, p<0.005; Experiment II, 88 ±3%, p<0.05). @*Conclusion@#Both water diuresis and osmotic diuresis are induced by cyclosporine nephrotoxicity. AQP2 and GLUT2 downregulation may underlie water and osmotic diuresis, respectively.

Urinary Concentration Defect and Renal Glycosuria in Cyclosporine-treated Rats

Background@#Urinary concentration impairment is a major feature of cyclosporine nephrotoxicity. @*Methods@#We explored two possible mechanisms that may underlie cyclosporineinduced polyuria; water, and/or osmotic diuresis. Cyclosporine was subcutaneously injected to normal salt-fed Sprague-Dawley rats at a daily dose of 25mg/kg for 2 weeks (Experiment I) and 7.5mg/kg for 6 weeks (Experiment II). @*Results@#In Experiment I, cyclosporine treatment caused an increase in urine volume (2.7±0.5 vs. 10.3±1.13mL/d/100 g BW, p<0.001) and a decrease in urine osmolality (2,831±554 vs. 1,379±478mOsm/kg H2O, p<0.05). Aquaporin-2 (AQP2) protein expression decreased in cyclosporine-treated rat kidneys (cortex, 78±8%, p<0.05; medulla, 80±1%, p<0.05). Experiment II also showed that urine volume was increased by cyclosporine treatment (4.97±0.66 vs. 9.65±1.76mL/d/100 g BW, p<0.05). Whereas urine osmolality was not affected, urinary excretion of osmoles was increased (7.5±0.4 vs. 14.9±1.4mosmoles/d/100 g BW, p<0.005). Notably, urinary excretion of glucose increased in cyclosporine-treated rats (7±1 vs. 10,932±2,462 mg/d/100 g BW, p<0.005) without a significant elevation in plasma glucose. In both Experiment I and II, GLUT2 protein expression in the renal cortex was decreased by cyclosporine treatment (Experiment I, 55±6%, p<0.005; Experiment II, 88 ±3%, p<0.05). @*Conclusion@#Both water diuresis and osmotic diuresis are induced by cyclosporine nephrotoxicity. AQP2 and GLUT2 downregulation may underlie water and osmotic diuresis, respectively.

Head to Head Comparison of Stress Echocardiography with Exercise Electrocardiography for the Detection of Coronary Artery Stenosis in Women

BACKGROUND: Exercise-stress electrocardiography (ECG) is initially recommended for the diagnosis of coronary artery disease. But its value has been questioned in women because of suboptimal diagnostic accuracy. Stress echocardiography had been reported to have comparable test accuracy in women. But the data comparing the diagnostic accuracy of exercise-stress ECG and stress echocardiography directly are few. The aim of the study was to compare the diagnostic accuracy of exercise-stress ECG and dobutamine stress echocardiography (DSE) in Korean women. METHODS: 202 consecutive female patients who presented with chest pain in outpatient clinic, and who underwent treadmill exercise test (TET), DSE and coronary angiography were included for the study. The diagnostic accuracy TET and DSE were calculated by the definition of > 50% or > 75% coronary artery stenosis (CAS). RESULTS: The sensitivity and specificity were higher with DSE (70.4, 94.6%) than TET (53.7, 73.6%) for detection of > 50% CAS. The higher accuracy of DSE was maintained after exclusion of the patients who could not achieve over 85% age predicted heart rate before ischemia induction. DSE also showed greater diagnostic accuracy than TET by > 75% CAS criteria, and in subsets of patient with intermediate pretest probability. CONCLUSION: In the diagnosis of CAS, DSE showed higher accuracy than TET in female patients who presented with chest pain. As well as the test accuracy, adequate stress was more feasible with DSE than TET. These finding suggests DSE may be used as the first-line diagnostic tool in the detection of CAS in women with chest pain.

Unexpected Pathologic Diagnosis of the Mitral Valvular Mass

A 59-year-old man with multifocal cerebral infarction was found to have the large obstructive mitral valvular mass. Although benign tumor was under suspicion before surgery, he was finally diagnosed as chronic infective endocarditis by microscopic evaluation. The precise diagnosis and the proper management of a cardiac mass are very important since even the benign tumor may cause fatal complications. However, primary cardiac mass has the broad spectrum from pseudo-tumor to malignancy and the differential diagnosis using non-invasive methods is not easy even with the currently available imaging techniques.

The Clinical and Laboratory Characteristics of Patients with Chronic Hepatitis B Using Current or Past Antiviral Therapy in Korea: A Multi-Center, Nation-Wide, Cross-Sectional Epidemiologic Study

BACKGROUND/AIMS: The proper assessment of the current disease status of patients with chronic hepatitis B would be valuable for establishing optimal management strategies. METHODS: The clinical and laboratory characteristics of 2,954 patients with current or previous antiviral treatment (46.2+/-10.8 years, 69.7% male) enrolled from 46 referral hospitals and 129 local hospitals or clinics throughout Korea were analyzed. RESULTS: The disease status included chronic hepatitis, cirrhosis, and hepatocellular carcinoma in 79.9%, 16.4%, and 3.7% of the patients, respectively. The major mode of hepatitis B virus (HBV) infection was vertical transmission. The hepatitis C virus (HCV) co-infection rate was 1.5%; however, only 50.8% of patients were evaluated for HCV. The use of herbal or complementary medicines was reported in 33.5% of the patients. The majority of patients (97.6%) were treated with oral nucleoside/nucleotide analogues. Several characteristics were different between the patients treated at referral hospitals and local hospitals/clinics, including the disease state, choice of antiviral drug, and methods of HBV DNA measurement. CONCLUSIONS: This study provides a comprehensive picture of the clinical and laboratory characteristics of patients treated in Korea. Efforts to optimize management strategies are warranted.

Cause of Chest Pain in a Patient with Previous Myocardial Infarction: Look Outside the Heart for Extracardiac Mass / 전남의대학술지

We report a case of thymic carcinoma that was initially detected by echocardiography in an 80-year-old male who visited the emergency room for chest pain and had a history of myocardial infarction and percutaneous coronary intervention. Transthoracic echocardiography showed a huge extracardiac mass that was located in the anterior mediastinum and was diagnosed as a thymic carcinoma by biopsy.

A Case of Stent Thrombosis Occurred at 5 Years after Sirolimus-Eluting Stent Implantation / 전남의대학술지

Drug-eluting stents (DES) have reduced the rate of repeated revascularization of target lesions. For this reason, DES are considered to be superior to bare-metal stents in reducing the restenosis rate. However, some problems have been reported after implantation of DES. One of them, stent thrombosis, has arisen as a fatal complication. Dual antiplatelet therapy is recommended for at least 12 months after implantation of DES to prevent stent thrombosis. Here, we report a case of very late stent thrombosis that occurred 1 week after discontinuation of clopidogrel at 5 years (1832 days) after implantation of a sirolimus-eluting stent.

Telmisartan Versus Valsartan in Patients With Hypertension: Effects on Cardiovascular, Metabolic, and Inflammatory Parameters

BACKGROUND AND OBJECTIVES: Angiotensin-receptor blockers (ARBs) have beneficial effects on cardiovascular, metabolic, and inflammatory parameters in addition to controlling blood pressure (BP). However, few comparative clinical studies have been conducted with different ARBs. We compared these effects in patients with uncomplicated hypertension who were receiving telmisartan or valsartan. SUBJECTS AND METHODS: The subjects were patients with essential hypertension (48.4+/-9.6 years) who were randomly assigned to take either telmisartan (80 mg/day, n=30) or valsartan (160 mg/day, n=30) for 12 weeks. Their anthropometric, laboratory, vascular, and echocardiographic data were measured at baseline and at the end of the study. RESULTS: Baseline characteristics were not significantly different between the two groups, except for the carotid-femoral pulse wave velocity (cfPWV; telmisartan group vs. valsartan group; 841.2+/-131.0 vs. 761.1+/-104.4 cm/s, p<0.05). After 12 weeks, BP had fallen to a similar extent with mean reductions in the systolic and diastolic BP of 20.7+/-18.1 and 16.3+/-13.0 mm Hg (p<0.001, respectively) for the telmisartan and 22.5+/-17.0 and 16.8+/-9.3 mm Hg (p<0.001, respectively) for the valsartan group. Although the cfPWV and left ventricular mass index (LVMI) fell significantly only with the administration of telmisartan, they were not significantly different when baseline cfPWV was considered. The differences in the cfPWV and LVMI changes from baseline between the two groups were also not significant after adjusting for baseline cfPWV. No significant changes in other vascular, metabolic, or inflammatory parameters were observed with either treatment. CONCLUSION: The effects of a 12-week treatment with the two ARBs, telmisartan and valsartan, on cardiovascular, metabolic, and inflammatory parameters were not different in patients with uncomplicated hypertension.

Cause of Chest Pain in a Patient with Previous Myocardial Infarction: Look Outside the Heart for Extracardiac Mass / 전남의대학술지

We report a case of thymic carcinoma that was initially detected by echocardiography in an 80-year-old male who visited the emergency room for chest pain and had a history of myocardial infarction and percutaneous coronary intervention. Transthoracic echocardiography showed a huge extracardiac mass that was located in the anterior mediastinum and was diagnosed as a thymic carcinoma by biopsy.

A Case of Stent Thrombosis Occurred at 5 Years after Sirolimus-Eluting Stent Implantation / 전남의대학술지

Drug-eluting stents (DES) have reduced the rate of repeated revascularization of target lesions. For this reason, DES are considered to be superior to bare-metal stents in reducing the restenosis rate. However, some problems have been reported after implantation of DES. One of them, stent thrombosis, has arisen as a fatal complication. Dual antiplatelet therapy is recommended for at least 12 months after implantation of DES to prevent stent thrombosis. Here, we report a case of very late stent thrombosis that occurred 1 week after discontinuation of clopidogrel at 5 years (1832 days) after implantation of a sirolimus-eluting stent.

A case of petrous carotid artery pseudoaneurysm presenting with epistaxis after radiotherapy in a patient with nasopharyngeal cancer / 대한내과학회지

Rupture of an internal carotid artery pseudoaneurysm is a rare but lethal complication in patients with nasopharyngeal cancer. Here, we report a case of severe nasal bleeding from a left petrous internal carotid artery aneurysm after chemoradiotherapy in a patient with nasopharyngeal cancer. A 76-year-old man who was being treated with concurrent chemoradiotherapy and who had achieved a complete response for 14 months developed massive epistaxis . A postnasal space computed tomography scan showed an enhanced nodular lesion at the left petrous internal carotid artery, and angiography revealed a pseudoaneurysm measuring 11.5x9.1 mm in the left internal carotid artery. Bleeding was well controlled with endovascular occlusion using a coil. The patient showed no recurrence of bleeding during follow-up.

A case of cardiac involvement in Churg-Strauss syndrome presenting without cardiomegaly in an asymptomatic patient / 대한내과학회지

We report a case of Churg-Strauss syndrome with cardiac involvement presenting without cardiomegaly or cardiopulmonary symptoms. A 47-year-old woman was referred to our institution for myalgia, peripheral numbness, and eosinophilia. She had been diagnosed with bronchial asthma and allergic rhinitis four years ago. The patient exhibited eosinophilia (71%) and elevated cardiac enzymes (cTnI, 2.977 ng/mL). Cardiomegaly was not observed on chest radiography, but nonspecific ST segment changes were observed on electrocardiography. A transthoracic echocardiography revealed a dilated left ventricular cavity, a decreased left ventricle (42%), and diastolic dysfunction. Contrast-enhanced cardiac magnetic resonance imaging revealed delayed hyperenhancement 10 minutes after injecting gadolinium. An endomyocardial biopsy showed eosinophilic myocarditis associated with vasculitis. The patient was diagnosed with Churg-Strauss syndrome and received combination therapy with steroid and cyclophosphamide. After the second treatment cycle, the blood eosinophilia disappeared and the vasculitis and infiltration of eosinophils into the endomyocardial tissue had completely resolved.

A Preliminary Study on the Effect of "Low-dose" Glucocorticoid Therapy for Patients with Persistent Acute Respiratory Distress Syndrome / 대한구급학회지

BACKGROUND: The role of glucocorticoids for treating persistent acute respiratory distress syndrome (ARDS) is matter of debate. In the previous studies, the side effects of moderate doses of glucocorticoids might have negated positive effects of glucocorticoids. This study aimed at determining the feasibility of administering "low-dose" glucocorticoid to treat the patients who suffer with persistent ARDS. METHODS: We retrospectively reviewed the medical records of twelve patients with ARDS of at least seven days' duration and who were treated with "low-dose" glucocorticoid (starting dose of 1 mg/kg) between June 2007 to December 2008. The patients were divided by whether or not they were successfully weaned from the ventilator after glucocorticoid therapy. The baseline characteristics and physiologic parameters were recorded for up to 7 days after starting glucocorticoid therapy. RESULTS: Five patients (42%) were included in the weaned group. There was no significant difference in the clinical characteristics and the physiologic parameters between the two groups on the day of ARDS. Yet the weaned group had a significantly lower Sequential Organ Failure Assessment (SOFA) score, as compared to that of the failed group [3 (3-6) vs 8 (5-12), p = 0.009)] at start of glucocorticoid treatment. After 3 days of glucocorticoid therapy, there was significant improvement in the PEEP, the PaO2/FIO2 ratio, the PCO2, the SOFA score and the Murray Lung Injury Score of the weaned group, as compared to that of the failed group. There were no major neuromuscular side effects from the therapy. CONCLUSIONS: This study suggests that the "low-dose" glucocorticoid therapy is feasible and that the SOFA score and the physiologic parameters may assist in determining whether or not to initiate and to continue glucocorticoid therapy for the patients who are suffering with persistent ARDS.

Prediction of Intubation after Bronchoscopy with Non-invasive Positive Pressure Ventilation Support in Patients with Acute Hypoxemic Respiratory Failure / 결핵및호흡기질환

BACKGROUND: Non-invasive positive pressure ventilation (NPPV) ensures adequate gas exchange during bronchoscopy in spontaneously breathing, hypoxemic patients, thus avoiding endotracheal intubation. However, in some patients, endotracheal intubation is eventually required after bronchoscopy. This study investigated the incidence of intubation and predictors of a need for emergency intubation prior to NPPV bronchoscopy initiation. METHODS: On a retrospective basis, we reviewed the medical records of 36 patients (median age, 55 years; interquartile range [IQR], 43~65 years) with acute hypoxemic respiratory failure who required NPPV during bronchoscopy between January 2005 and October 2007. RESULTS: All patients were hypoxemic (median PaO2/FiO2 ratio 155; IQR 90~190), but tolerated bronchoscopy with NPPV support. SOFA score and SAPS II score immediately before NPPV initiation were 4 (3~7) and 36 (30~42), respectively. Seventeen (47%) patients needed endotracheal intubation at a median time of 22 (2~50) hours after bronchoscopy. Patients who needed intubation after bronchoscopy had a higher in-hospital mortality (11 [65%] vs. 4 [21%], p=0.017). Upon multiple logistic regression analysis, the need for intubation after bronchoscopy was independently associated with a PaO2/FiO2 ratio (OR, 0.961; 95% CI, 0.924~0.999; p=0.047) immediately before NPPV initiation for bronchoscopy. CONCLUSION: The severity of the hypoxemia immediately prior to NPPV initiation for bronchoscopy was associated with the need for intubation after bronchoscopy in patients with hypoxemic respiratory failure.