- [Show abstract] [Hide abstract] ABSTRACT: In this study, we characterized cerebral blood flow changes by assessment of blood flow parameters in neck arteries using carotid duplex ultrasonography and predictive factors for these hemodynamic changes. Hemodynamic variables were measured before and during hemodialysis in 81 patients with an arteriovenous access in their arm. Hemodialysis produced significant lowering in peak systolic velocity and flow volume of neck arteries and calculated total cerebral blood flow (1,221.9 ± 344.9 [before hemodialysis] vs. 1,085.8 ± 319.2 [during hemodialysis], P < 0.001). Effects were greater in vessels on the same side as the arteriovenous access and these changes were influenced by arteriovenous access flow during hemodialysis, both in the CCA (r = -0.277, P = 0.015) and the VA (r = -0.239, P = 0.034). The change of total cerebral blood flow during hemodialysis was independently related with age, presence of diabetes, and systemic blood pressure.
Dataset: Supplementary Table 1[Show abstract] [Hide abstract] ABSTRACT: Characteristics of patients reporting dizziness during hemodialysis
- [Show abstract] [Hide abstract] ABSTRACT: [This corrects the article DOI: 10.1371/journal.pone.0158810.].
- [Show abstract] [Hide abstract] ABSTRACT: Background/aims: Both endothelin-1 (ET-1) and the renin-angiotensin system (RAS) may play important roles in renal fibrosis in the obstructed kidney. However, there have been few clear demonstrations of a relationship between their activation and additive or synergistic roles in renal fibrosis. We investigated the protective roles and relationship between renal RAS and ET-1 in unilateral ureteral obstruction (UUO) mice. Methods: 8-week-old male C57BL/6 mice were divided into seven groups: sham, bosentan+sham, valsartan+sham, vehicle+UUO, bosentan+UUO, valsartan+UUO, and valsartan+bosentan+UUO. Valsartan and bosentan were administered orally using an NG tube (valsartan 10 mg/kg/day, bosentan 100 mg/kg/day for 8 days, after which the molecular and structural kidney parameters were evaluated. Bosentan treatment elevated plasma renin activity, renal renin, and AT1R expression in UUO mice. Results: Although valsartan decreased plasma ET-1 in these mice, it did not affect ET(A) or ET(B) in their kidneys. Co-treatment with valsartan and bosentan decreased ET-1 in these mice compared to the single treatments. Bosentan, but not valsartan, elevated eNOS expression in their kidneys. Co-treatment with valsartan and bosentan reduced TGF-β, α-SMA, and collagen IV expression, and the Masson's trichrome stained area in their kidneys. Conclusions: Bosentan and valsartan acted complementarily, and co-treatment with both drugs had an additive protective effect against renal fibrosis.
- [Show abstract] [Hide abstract] ABSTRACT: Dapagliflozin, a new type of drug used to treat diabetes mellitus (DM), is a sodium/glucose cotransporter 2 (SGLT2) inhibitor. Although some studies showed that SGLT2 inhibition attenuated reactive oxygen generation in diabetic kidney the role of SGLT2 inhibition is unknown. We evaluated whether SLT2 inhibition has renoprotective effects in ischemia-reperfusion (IR) models. We evaluated whether dapagliflozin reduces renal damage in IR mice model. In addition, hypoxic HK2 cells were treated with or without SGLT2 inhibitor to investigate cell survival, the apoptosis signal pathway, and the induction of hypoxia-inducible factor 1 (HIF1) and associated proteins. Dapagliflozin improved renal function. Dapagliflozin reduced renal expression of Bax, renal tubule injury and TUNEL-positive cells and increased renal expression of HIF1 in IR-injured mice. HIF1 inhibition by albendazole negated the renoprotective effects of dapagliflozin treatment in IR-injured mice. In vitro, dapagliflozin increased the expression of HIF1, AMP-activated protein kinase (AMPK), and ERK and increased cell survival of hypoxic HK2 cells in a dose-dependent manner. In conclusion, dapagliflozin attenuates renal IR injury. HIF1 induction by dapagliflozin may play a role in renoprotection against renal IR injury.
- [Show abstract] [Hide abstract] ABSTRACT: Background: "Spinning" is an indoor cycling regimen. The number of case reports of spinning-induced rhabdomyolysis (SIR) has increased since 2004 in South Korea. Aim: Our aim of this study is evaluating the clinical characteristics of SIR and compared it with other causes of rhabdomyolysis METHODS: From September 1, 2011, to April 30, 2015, patients who were diagnosed with rhabdomyolysis were included. We analysed the incidence of rhabdomyolysis, biochemical parameters and forced hospitalization which was defined as the days from admission to creatinine phosphokinase (CPK) < 2,000 IU/L. Results Among 70 included patients, 13 (18.6%) patients were diagnosed with SIR. The mean age of the patients with SIR was 25.69 ± 5.0 years and most were females under 35 years old (12, 92.3%). Interestingly, the mean duration of spinning exercise before admission was only 59.23 minutes. Moreover, the patients with SIR showed more severe progress than the all-patients-except-SIR (AESIR) group. The serum CPK, AST, and ALT levels of the patients with SIR were stastically significant higher than the patients with AESIR. Additionally, the duration of forced hospitalization was longer than that of the AESIR (p < 0.01). Conclusions: Spinning could be an important cause of rhabdomyolysis in young, unfit females, which is typically severe. A graded exercise program is advised at the first session.
- [Show abstract] [Hide abstract] ABSTRACT: Background: Idiopathic edema (IE) is a common clinical syndrome. Designing treatment plans for IE is problematic because of the difficulty in assessing volume status. We aimed to evaluate volume status, measured by bioimpedance spectroscopy (BIS), and investigated clinical parameters associated with volume overload (VO) in patients with IE. Methods: Patients with IE were defined as those with symptomatic edema and without abnormal renal function or any other apparent cause of edema. A total of 124 patients were included. Overhydration (OH) and extracellular water (ECW) were calculated using BIS. Relative hydration status (x0394;HS) was defined as OH/ECW. Patients were classified into 2 groups: overhydrated group (OG; x0394;HS ≥7%) and non-OG (NOG; x0394;HS <7). Simple and multiple logistic regression analyses were used to assess the influence of several variables on the incidence of VO. Results: Of 124 patients, 37 (29.8%) were in the OG. The proportion of men in the OG was higher than that in the NOG (p = 0.020). Patients in the OG showed more frequent pretibial pitting edema (PTPE, p < 0.001) and had lower hemoglobin (p = 0.008) and serum albumin levels (p < 0.001). The multivariate analysis showed that the presence of PTPE (OR 10.62, 95% CI 1.98-57.1), low serum albumin level (OR 0.01, 95% CI 0.00-0.25) and lower fat tissue index (OR 0.78, 95% CI 0.63-0.97) were independent risk factors for the presence of VO. Conclusions: BIS helps to identify volume status and body composition in patients with IE.
- [Show abstract] [Hide abstract] ABSTRACT: Background/aims: Fragmented care in nephrology can cause treatment delays. Nephrologists are qualified to perform vascular access-related procedures because they understand the pathophysiology of renal disease and perform physical examination for vascular access. We compared treatment delays associated with tunneled hemodialysis catheter (TDC) placement between interventional radiologists and nephrologists. Methods: We collected data by radiologists from January 1, 2011 through December 31, 2011 and by nephrologists from since July 1, 2012 through June 30, 2013. We compared the duration from the hemodialysis decision to TDC placement (D-P duration) and hemodialysis initiation (D-H duration), catheter success and the complication rate, and the frequency and the usage time of non-tunneled hemodialysis catheters (NDCs) before TDC placement. Results: The study analyzed 483 placed TDCs: 280 TDCs placed by radiologists and 203 by nephrologists. The D-P durations were 319 minutes (interquartile range [IQR], 180 to 1,057) in the radiologist group and 140 minutes (IQR, 0 to 792) in the nephrologist group. Additionally, the D-H durations were 415 minutes (IQR,260 to 1,091) and 275 minutes (IQR, 123 to 598), respectively. These differences were statistically significant (p = 0.00). The TDC success rate (95.3% vs. 94.5%, respectively; p = 0.32) and complication rate (16.2% vs. 11%, respectively; p = 0.11) did not differ between the groups. The frequency (24.5 vs. 26%, respectively; p = 0.72) and the usage time of NDC (8,451 vs. 8,416 minutes, respectively; p = 0.91) before TDC placement were not statistically significant. Conclusions: Trained interventional nephrologists could perform TDC placement safely, minimizing treatment delays.
- [Show abstract] [Hide abstract] ABSTRACT: Background/Aims: There has been controversy about the role of Toll-like receptor 2 (TLR2) in renal injury following ureteric obstruction. Although inhibition of the renin angiotensin system (RAS) reduces TLR2 expression in mice, the exact relationship between TLR2 and RAS is not known. The aim of this study was to determine whether the RAS modulates TLR2. Methods: We used 8-week-old male wild type (WT) and TLR2-knockout (KO) mice on a C57Bl/6 background. Unilateral ureteral obstruction (UUO) was induced by complete ligation of the left ureter. Angiotensin (Ang) II (1,000 ng/kg/ min) and the direct renin inhibitor aliskiren (25 mg/kg/day) were administrated to mice using an osmotic minipump. Molecular and histologic evaluations were performed. Results: Ang II infusion increased mRNA expression of TLR2 in WT mouse kidneys (p < 0.05). The expression of renin mRNA in TLR2-KO UUO kidneys was significantly higher than that in WT UUO kidneys (p < 0.05). There were no differences in tissue injury score or mRNA expression of monocyte chemotactic protein 1 (MCP-1), osteopontin (OPN), or transforming growth factor β (TGF-β) between TLR2-KO UUO and WT UUO kidneys. However, aliskiren decreased the tissue injury score and mRNA expression of TLR2, MCP-1, OPN, and TGF-β in WT UUO kidneys (p < 0.05). Aliskiren-treated TLR2-KO UUO kidneys showed less kidney injury than aliskiren-treated WT UUO kidneys. Conclusions: TLR2 deletion induced activation of the RAS in UUO kidneys. Moreover, inhibition of both RAS and TLR2 had an additive ameliorative effect on UUO injury of the kidney.
- [Show abstract] [Hide abstract] ABSTRACT: Beta-blockers such as propranolol and labetalol is known to induce toxic myopathy because of their partial beta-2 adrenoceptor agonistic effect. Nebivolol has the highest beta-1 receptor affinity among beta-blockers and it has never been reported to induce rhabdomyolysis until now. We report a patient who developed rhabdomyolysis after changing medication to nebivolol. A 75-year old woman was admitted to our hospital because of generalized weakness originating 2 weeks before visiting. Approximately 1 month prior to her admission, her medication was changed from carvedilol 12.5 mg to nebivolol 5 mg. Over this time span she had no other life style changes causing rhabdomyolysis. Her blood chemistry and whole body bone scan indicated rhabdomyolysis. We considered newly prescribed nebivolol as a causal agent. She was prescribed carvedilol 12.5mg, which she was previous taken, instead of nebivolol. She was treated with hydration and urine alkalization. She was fully recovered and discharged.
- [Show abstract] [Hide abstract] ABSTRACT: Recently, a new glomerular filtration rate (GFR) equation for the Japanese population was proposed using measured inulin clearance. To expand its applicability to other Asian populations, we performed a comparative study in the Korean population. Inulin clearance was measured in 166 patients from seven participating medical centers in Korea. Patient's sera and urine were collected, and baseline clinical characteristics were measured to provide an estimated GFR (eGFR) by the Japanese GFR equation using inulin clearance (Japanese-GFR equation), the Modification of Diet in Renal Disease (MDRD) study equation, and the Chronic Kidney Disease - Epidemiology Collaboration (CKD-EPI) equation. We compared the results to determine which equation best estimated the measured GFR (mGFR). Accuracy (95% CI) within 30% of mGFR by the Japanese-GFR equation, the CKD-EPI equation and the MDRD study equation were 66 (58 - 72), 51 (43 - 58), and 55 (47 - 62)%, respectively. Bias (mGFR minus eGFR) were 3.4 ± 22.4, -12.0 ± 22.1, and -9.7 ± 23.8 mL/min/1.73 m2, respectively. The accuracy of the Japanese-GFR equation was significantly better than MDRD study equation in subjects with mGFR < 60 mL/min/1.73 m2 and in total subjects. The bias of the Japanese-GFR equation was significantly smaller compared with other two equations in total subjects. The Japanese-GFR equation has a higher accuracy with less bias than the other equations in estimating GFR in Korean populations. Further studies are required to determine if the current Japanese-GFR equation could represent the standard eGFR for other Asian populations.
- [Show abstract] [Hide abstract] ABSTRACT: Background: Bioimpedance analysis (BIA) helps measuring the constituents of the body noninvasively. Prior studies suggest that BIA-guided fluid assessment helps to predict survival in dialysis patients. We aimed to evaluate the clinical usefulness of BIA for predicting the survival rate of hemodialysis patients in Korea. Methods: We conducted a single-center retrospective study. All patients were diagnosed with end-stage renal disorder and started maintenance hemodialysis between June 2009 and April 2014. BIA was performed within the 1(st) week from the start of hemodialysis. The patients were classified into 2 groups based on volume status measured by the body composition monitor (BCM; Fresenius): an overhydrated group [OG; overhydration/extracellular water (OH/ECW) >15%] and a nonoverhydrated group (NOG; OH/ECW ≤15%). Results: A total of 344 patients met the inclusion criteria. Of these, 252 patients (73.3%) were categorized into the OG and 92 patients (26.7%) into the NOG. Age- and sex-matching patients were selected with a rate of 2:1. Finally, 160 overhydrated patients and 80 nonoverhydrated patients were analyzed. Initial levels of hemoglobin and serum albumin were significantly lower in the OG. During follow-up, 43 patients from the OG and 7 patients from the NOG died (median follow-up duration, 24.0 months). The multivariate-adjusted all-cause mortality was significantly increased in the OG (odds ratio, 2.569; P = 0.033) and older patients (odds ratio, 1.072/y; P < 0.001). No significant difference of all-cause or disease-specific admission rate was observed between the 2 groups. Conclusion: The ratio of OH/ECW volume measured with body composition monitor is related to the overall survival of end-stage renal disorder patients who started maintenance hemodialysis.
- [Show abstract] [Hide abstract] ABSTRACT: Idiopathic membranous glomerulonephritis (IMGN) is commonly diagnosed in adults with proteinuria. Rapid deterioration of renal function is a rare complication of IMGN, except when accompanied by renal vein thrombosis, malignant hypertension, or other underlying disease, including lupus nephritis. Here, we present a case of rapid deterioration of renal function in a patient with MGN superimposed with anti-neutrophil cytoplasmic antibody (ANCA)-associated rapidly progressive crescentic glomerulonephritis (RPGN). Overall, about 20 cases of MGN with ANCA-associated RPGN have been reported. This case of biopsy-proven MGN with ANCA-associated RPGN is the first to be reported in Korea.
- [Show abstract] [Hide abstract] ABSTRACT: In hemodialysis patients, vascular access infection remains a significant cause of morbidity and mortality. It has various complications, including bacterial endocarditis, spinal epidural abscess, osteomyelitis, septic arthritis, and septic pulmonary emboli. However, aortitis with infected pseudoaneurysm formation is very rare. Here, we report a case of necrotizing aortitis in a hemodialysis patient with an arteriovenous graft infection.
Conference Paper: Experimental acute kidney injury.[Show abstract] [Hide abstract] ABSTRACT: Introduction and Aims: Acute interstitial nephritis (AIN) is a common cause of acute kidney injury (AKI). In severe cases, AIN may progress to chronic kidney disease or end-stage renal disease. We previously reported that WNT10A is a novel angio/stromagenic factor in wound healing and organ fibrosis. In this study, we investigated the role of WNT10A in fibrotic progression of AIN. Methods: Kidney biopsy specimens from 25 AKI patients (all men, ≥60 years) treated in our hospital between 2007 and 2013 were examined for WNT proteins, α-SMA, and fibronectin expression by immunohistochemistry. The relationship between each WNT proteins expression level and estimated glomerular filtration rate (eGFR) was evaluated by the Mann-Whitney U test. COS1 cells (kidney fibroblasts from African green monkey) were transfected with a WNT10A expression plasmid or a siRNA targeting peroxiredoxin 5 (PRDX5). The effects of WNT10A overexpression and PRDX5 knockdown on proliferation and hydrogen peroxide induced cytotoxicity were measured by WST-8 assay. Results: The 10 patients exhibiting WNT10A expression in biopsy tissue had significantly lower eGFR values (median, 11.12 mL/min per 1.73 m2; range, 7.16−28.15 mL/min per 1.73 m2) than the 15 patients exhibiting no detectable WNT10A expression (34.70, 8.37−134.58; p = 0.0033). There was no significant relationship between eGFR and the expression level of any other WNT protein examined (WNT-1, -3, and -4). Overexpression of WNT10A in COS1 cells enhanced proliferation, fibronectin expression, PRDX5 expression, and resistance to hydrogen peroxide, while PRDX5 downregulation sensitized COS1 cells to hydrogen peroxide. Conclusions: WNT10A expression may promote fibrotic progression and kidney dysfunction in AIN. Blockade of WNT10A expression may be a feasible therapeutic strategy against kidney fibrosis.
- [Show abstract] [Hide abstract] ABSTRACT: Severe hypernatremia is an important electrolyte disorder that has serious effects. The patient had no medical history. A. 20-year-old ingested bamboo salt for digestion and weight reduction according to the folk remedies posted on an internet website. She presented with vomiting and diarrhea over ten times per day. Her initial serum sodium concentration was 174mEq/L. Her symptoms improved rapidly with hypotonic saline infusion. She recovered completely without any sequelae in three days. Severe hypernatremia in a normal young adult with clear consciousness and normal renal function has not been reported in Korea yet. So we report a case of severe hypernatremia by excessive bamboo salt ingestion in healthy young woman.
- [Show abstract] [Hide abstract] ABSTRACT: Unlabelled: Ischemia/reperfusion (I/R) is the most common cause of acute renal injury. I/R-induced reactive oxygen species (ROS) are thought to be a major factor in the development of acute renal injury by promoting the initial tubular damage. Nad(p)h: quinone oxidoreductase 1 (NQO1) is a well-known antioxidant protein that regulates ROS generation. The purpose of this study was to investigate whether NQO1 modulates the renal I/R injury (IRI) associated with NADPH oxidase (NOX)-derived ROS production in an animal model. We analyzed renal function, oxidative stress, and tubular apoptosis after IRI. NQO1(-/-) mice showed increased blood urea nitrogen and creatinine levels, tubular damage, oxidative stress, and apoptosis. In the kidneys of NQO1(-/-) mice, the cellular NADPH/NADP(+) ratio was significantly higher and NOX activity was markedly higher than in those of NQO1(+/+) mice. The activation of NQO1 by β-lapachone (βL) significantly improved renal dysfunction and reduced tubular cell damage, oxidative stress, and apoptosis by renal I/R. Moreover, the βL treatment significantly lowered the cellular NADPH/NADP(+) ratio and dramatically reduced NOX activity in the kidneys after IRI. From these results, it was concluded that NQO1 has a protective role against renal injury induced by I/R and that this effect appears to be mediated by decreased NOX activity via cellular NADPH/NADP(+) modulation. These results provide convincing evidence that NQO1 activation might be beneficial for ameliorating renal injury induced by I/R.
- [Show abstract] [Hide abstract] ABSTRACT: Background The aim of this study was to evaluate the clinical characteristics of nondiabetic nephropathy in type 2 diabetes mellitus patients and to find a clinical significance of renal biopsy and immunosuppressive treatment in such a patient. Methods Renal biopsy results, clinical parameters, and renal outcomes were analyzed in 75 diabetic patients who underwent kidney biopsy at Chungnam National University Hospital from January 1994 to December 2010. Results The three most common reasons for renal biopsy were nephrotic range proteinuria (44%), proteinuria without diabetic retinopathy (20%), and unexplained decline in renal function (20.0%). Ten patients (13.3%) had only diabetic nephropathy (Group I); 11 patients (14.7%) had diabetic nephropathy with superimposed nondiabetic nephropathy (Group II); and 54 patients (72%) had only nondiabetic nephropathy (Group III). Membranous nephropathy (23.1%), IgA nephropathy (21.5%), and acute tubulointerstitial nephritis (15.4%) were the three most common nondiabetic nephropathies. Group III had shorter duration of diabetes and lesser diabetic retinopathy than Groups I and II (P=0.008). Group II had the lowest baseline estimated glomerular filtration rate (P=0.002), with the greatest proportion of renal deterioration during follow-up (median 38.0 months, P<0.0001). The patients who were treated with intensive method showed better renal outcomes (odds ratio 4.931; P=0.01). Absence of diabetic retinopathy was associated with favorable renal outcome in intensive treatment group (odds ratio 0.114; P=0.032). Conclusion Renal biopsy should be recommended for type 2 diabetic patients with atypical nephropathy because a considerable number of these patients may have nondiabetic nephropathies. And intensive treatment including corticosteroid or immunosuppressants could be recommended for type 2 diabetic patients with nondiabetic nephropathy, especially if the patients do not have diabetic retinopathy.
- [Show abstract] [Hide abstract] ABSTRACT: Background: The purpose of this study is to identify whether hemoglobin (Hb) concentrations can be maintained, and to investigate changes in biomarkers, when switching from erythropoietin stimulating agents (ESA) with shorter half-life to once-monthly subcutaneous methoxy polyethylene glycol-epoetin β (CERA) in pre-dialysis chronic kidney disease (CKD) patients. Methods: Pre-dialysis CKD patients (n=191) aged ≥18 years who maintained their Hb level 10-12 g/dL through use of epoetin-α, epoetin-β, or darbepoetin-α were enrolled. Hb levels and CERA dose was assessed prospectively for 24 weeks. Serum biomarkers related to coagulation, endothelial function, and iron metabolism were measured at weeks 0 and 24. Results: Baseline Hb concentration was 10.8±0.6 g/dL Twelve and 24 weeks after conversion, mean Hb levels were 11.9±0.9 and 11.2±0.9 g/dL, respectively. The mean monthly CERA dose required to maintain Hb levels was gradually reduced. Of total 387 dose adjustments, dose increases and decreases occurred in 35 (9.0%) and 352 (91.0%) episodes, respectively. Hb overshoot occurred in 14 (9.7%) patients. P-selectin was significantly decreased, whereas VCAM was significantly increased 24 weeks after conversion (P < 0.05). Serum soluble transferrin receptor E-selectin and prohepcidin levels were similar before and after switching to CERA (P=N-S). Conclusion: Conversion from ESA with shorter half-life to subcutaneous once-monthly CERA in pre-dialysis CKD patients can efficaciously maintain Hb. The CERA dose requirement decreased significantly. The conversion ratio may need to be reduced when switching from ESA with shorter half-life to CERA. CERA may change biomarkers associated with platelet reactivity and endothelial microenvironment.
Chungnam National University HospitalSŏul, Seoul, South Korea
HYUNDAI MOBISSŏul, Seoul, South Korea