• Toxicological Research
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• v.32 no.1
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• pp.47-56
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• 2016

The identification of biomarkers for the early detection of acute kidney injury (AKI) is clinically important. Acute kidney injury (AKI) in critically ill patients is closely associated with increased morbidity and mortality. Conventional biomarkers, such as serum creatinine (SCr) and blood urea nitrogen (BUN), are frequently used to diagnose AKI. However, these biomarkers increase only after significant structural damage has occurred. Recent efforts have focused on identification and validation of new noninvasive biomarkers for the early detection of AKI, prior to extensive structural damage. Furthermore, AKI biomarkers can provide valuable insight into the molecular mechanisms of this complex and heterogeneous disease. Our previous study suggested that pyruvate kinase M2 (PKM2), which is excreted in the urine, is a sensitive biomarker for nephrotoxicity. To appropriately and optimally utilize PKM2 as a biomarker for AKI requires its complete characterization. This review highlights the major studies that have addressed the diagnostic and prognostic predictive power of biomarkers for AKI and assesses the potential usage of PKM2 as an early biomarker for AKI. We summarize the current state of knowledge regarding the role of biomarkers and the molecular and cellular mechanisms of AKI. This review will elucidate the biological basis of specific biomarkers that will contribute to improving the early detection and diagnosis of AKI.

• Journal of Yeungnam Medical Science
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• v.31 no.2
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• pp.127-130
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• 2014

Autoimmune thyroiditis is the most common cause of hypothyroidism in the world. It is characterized clinically by gradual thyroid failure, goiter formation, or both, because of the autoimmune-mediated destruction of the thyroid gland. Renal involvement presenting proteinuria in autoimmune thyroiditis is not uncommon, occurring in 10% to 30% of the cases. Glomerulonephropathy associated with autoimmune thyroiditis, however, is a rare disease. Most reports of autoimmune thyroiditis with glomerulonephropathy have demonstrated a mixed pathological morphology and have been predominantly associated with membranous glomerulopathy. The case of minimal-change disease associated with thyroiditis presenting acute kidney injury is a rare disease that has not been reported in South Korea. Reported herein is the case of a 16-year-old man diagnosed with Hashimoto's thyroiditis, with minimal-change disease presenting acute kidney injury. He revealed hypothyroidism, proteinuria, and impaired renal function. Renal biopsy showed minimal-change disease and minimal tubular atrophy. The patient was treated with thyroid hormone, and his renal function and proteinuria improved. Therefore, for patients with autoimmune thyroiditis presenting unexplained proteinuria, glomer-ulonephropathy should be ruled out. Conversely, for patients with glomerulonephropathy and persistent proteinuria despite proper treatment, thyroid function and antibody tests should be performed.

• Yonsei Medical Journal
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• v.59 no.9
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• pp.1015-1025
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• 2018

Kidney diseases including acute kidney injury and chronic kidney disease are among the largest health issues worldwide. Dialysis and kidney transplantation can replace a significant portion of renal function, however these treatments still have limitations. To overcome these shortcomings, a variety of innovative efforts have been introduced, including cell-based therapies. During the past decades, advances have been made in the stem cell and developmental biology, and tissue engineering. As part of such efforts, studies on renal cell therapy and artificial kidney developments have been conducted, and multiple therapeutic interventions have shown promise in the pre-clinical and clinical settings. More recently, therapeutic cell-secreting secretomes have emerged as a potential alternative to cell-based approaches. This approach involves the use of renotropic factors, such as growth factors and cytokines, that are produced by cells and these factors have shown effectiveness in facilitating kidney function recovery. This review focuses on the renotropic functions of bioactive compounds that provide protective and regenerative effects for kidney tissue repair, based on the available data in the literature.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.347-355
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• 2018

Background: Nephrotic syndrome (NS) is the most common glomerulopathy in children. Acute kidney injury (AKI) is a common complication of NS, caused by severe intravascular volume depletion, acute tubular necrosis, interstitial nephritis, or progression of NS. However, the incidence and risk factors of childhood-onset NS in Korea are unclear. Therefore, we studied the incidence, causes, and risk factors of AKI in hospitalized Korean patients with childhood-onset NS. Methods: We conducted a retrospective review of patients with childhood-onset NS who were admitted to our center from January 2015 to July 2017. Patients with decreased renal function or hereditary/secondary NS, as well as those admitted for management of other conditions unrelated to NS, were excluded. Results: During the study period, 65 patients with idiopathic, childhood-onset NS were hospitalized 90 times for management of NS or its complications. Of these 90 cases, 29 met the Kidney Disease Improving Global Outcomes criteria for AKI (32.2%). They developed AKI in association with infection (n = 12), NS aggravation (n = 11), dehydration (n = 3), and intravenous methylprednisolone administration (n = 3). Age ${\geq}9$ years at admission and combined use of cyclosporine and renin-angiotensin system inhibitors were risk factors for AKI. Conclusion: AKI occurred in one-third of the total hospitalizations related to childhood-onset NS, owing to infection, aggravation of NS, dehydration, and possibly high-dose methylprednisolone treatment. Age at admission and use of nephrotoxic agents were associated with AKI. As the AKI incidence is high, AKI should be considered during management of high-risk patients.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.2
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• pp.135-143
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• 2018

Tumor necrosis $factor-{\alpha}$ ($TNF{\alpha}$) and the angiotensin system are involved in inflammatory diseases and may contribute to acute kidney injury. We investigated the mechanisms by which $TNF{\alpha}$-converting enzyme (TACE) contributes to lipopolysaccharide (LPS)-induced renal inflammation and the effect of TACE inhibitor treatment on LPS-induced cellular injury in human renal proximal tubule epithelial (HK-2) cells. Mice were treated with LPS (10 mg/kg, i.p.) and HK-2 cells were cultured with or without LPS ($10{\mu}g/ml$) in the presence or absence of a type 1 TACE inhibitor ($1{\mu}M$) or type 2 TACE inhibitor ($10{\mu}M$). LPS treatment induced increased serum creatinine, $TNF{\alpha}$, and urinary neutrophil gelatinase-associated lipocalin. Angiotensin II type 1 receptor, mitogen activated protein kinase (MAPK), and TACE increased, while angiotensin-converting enzyme-2 (ACE2) expression decreased in LPS-induced acute kidney injury and LPS-treated HK-2 cells. LPS induced reactive oxygen species and the down-regulation of ACE2, and these responses were prevented by TACE inhibitors in HK-2 cells. TACE inhibitors increased cell viability in LPS-treated HK-2 cells and attenuated oxidative stress and inflammatory cytokines. Our findings indicate that LPS activates renin angiotensin system components via the activation of TACE. Furthermore, inhibitors of TACE are potential therapeutic agents for kidney injury.

• Childhood Kidney Diseases
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• v.16 no.1
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• pp.63-67
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• 2012

Acute pyelonephritis (APN) is a relatively common bacterial infection in children. In previously healthy children, acute kidney injury (AKI) is very rare in the course of APN without urinary tract obstruction, renal hypoperfusion due to hypotension or exposure to nephrotoxic agents. We describe a case of AKI secondary to APN and renal abscess in a child with vesicoureteral reflux. With antibiotic treatment and adequate hydration, the patient was improved. APN should be included in the differential diagnosis of AKI and adequate treatment by proper antibiotics is crucial for full recovery of renal function.

• Journal of Yeungnam Medical Science
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• v.28 no.1
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• pp.54-59
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• 2011

Leptospirosis is a spirochetal infectious disease caused by $Leptospira$ $interrogans$, and may vary in degree from an asymptomatic infection to a severe and fatal illness. The kidney is one of the principal target organs of $Leptospira$. Renal disorders caused by $Leptospira$ infection vary from an abnonnality in urinalysis to acute kidney injury (AKI). Incidence of AKI in severe leptospirosis varies from 40% to 60%. AKI reflects the severity of leptospirosis and is generally accompanied by cholestatic jaundice. The pathophysiology of AKI in leptospirosis consists of hypovolemia, direct tubular toxicity, and rhabdomyolysis. Most patients with acute leptospirosis experience severe myalgias, and show laboratory evidence of mild rhabdomyolysis. However, occurrence of severe rhabdomyolysis is rare. We report here on a patient with leoptospirosis, who had severe rhabdomyolysis and acute kidney injury without jaundice.

• Journal of Yeungnam Medical Science
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• v.32 no.1
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• pp.17-21
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• 2015

Amlodipine, a calcium channel blocker of the dihydropyridine group, is commonly used in management of hypertension, angina, and myocardial infarction. Amlodipine overdose, characterized by severe hypotension, arrythmias, and pulmonary edema, has seldom been reported in Korean literature. We report on a fatal case of amlodipine intoxication with complications including rhabdomyolysis and oliguric acute kidney injury. A 70-year-old woman with a medical history of hypertension was presented at the author's hospital 6 hours after ingestion of 50 amlodipine (norvasc) tablets (total dosage 250 mg) in an attempted suicide. Her laboratory tests showed a serum creatinine level of 2.5 mg/dL, with elevated serum creatine phosphokinase and myoglobin. The patient was initially treated with fluids, alkali, calcium gluconate, glucagon, and vasopressors without a hemodynamic effect. High-dose insulin therapy was also started with a bolus injection of regular insulin (RI), followed by continuous infusion of RI and 50% dextrose with water. Despite intensive treatment including insulin therapy, inotropics, mechanical ventilation, and continuous venovenous hemodiafiltration, the patient died of refractory shock and cardiac arrest with no signs of renal recovery 116 hours after her hospital admission.

• Annals of Clinical Neurophysiology
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• v.24 no.2
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• pp.93-97
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• 2022

Posterior reversible encephalopathy syndrome (PRES) is a rare condition manifested by inflammation in certain areas of the brain. Rhabdomyolysis with acute kidney injury (AKI) complicated by PRES is rarely reported. A 26-year-old female presented with neurological symptoms, high blood pressure, and AKI. Her symptoms improved with blood pressure control, anticonvulsant drug medications, and renal replacement therapy. This case demonstrates that PRES should be considered in the differential diagnosis of patients who have rhabdomyolysis with AKI accompanied by neurological symptoms, including headaches and convulsions.

• Neonatal Medicine
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• v.17 no.2
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• pp.168-180
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• 2010

Acute renal failure (ARF) is common in the neonatal period, however, there are no uniform treatment strategies of ARF. The main treatment strategies are conservative management including medical treatment and the renal replacement therapy. Because ARF in the newborn is commonly acquired by hypoxic ischemic injury and toxic insults, removal of all the offending causes is important. Aminoglycoside, indomethacin, and amphotericin-B are the most common nephrotoxic drugs of ARF. To relieve the possible prerenal ARF, initial fluid challenge can be followed by diuretics. If there is no response, fluid restriction and correction of electrolyte imbalance should begin. Adequate nutritional support and drug dosing according to the pharmacokinetics of such drugs will be difficult problems. Renal replacement therapies may be provided by peritoneal dialysis, intermittent hemodialysis, or hemofiltration. New promising agents, bioartificial kidney, and stem cell will enable us to extend our therapeutic repertoire.