1.Use of Angiotensin Converting Enzyme Inhibitors and Angiotensin Receptor Blockers: A Closer Look at Hyperkalemia.
Sungjin CHUNG ; Cheol Whee PARK
Korean Journal of Medicine 2011;80(1):20-30
Therapeutic manipulation of the renin-angiotensin-aldosterone system (RAAS) is an important strategy for improving hypertension, diabetes, cardiovascular disease, and chronic kidney disease. Development of hyperkalemia after the administration of RAAS inhibitors is of particular concern because patients at highest risk for this complication are often the same patients who derive the greatest cardiovascular or renoprotective benefit. Based on an overview of the incidence of hyperkalemia during treatment with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers alone and in combination, this review suggests approaches for monitoring, detecting, and managing hyperkalemia in patients treated with RAAS inhibitors. Although the incidence of hyperkalemia with RAAS inhibitors is generally low, hyperkalemia can be associated with increased mortality. When using RAAS inhibitors, it is important to monitor on-treatment electrolyte levels and renal function parameters in patients with a high risk for hyperkalemia.
Angiotensin Receptor Antagonists
;
Angiotensin-Converting Enzyme Inhibitors
;
Angiotensins
;
Cardiovascular Diseases
;
Humans
;
Hyperkalemia
;
Hypertension
;
Incidence
;
Organothiophosphorus Compounds
;
Peptidyl-Dipeptidase A
;
Renal Insufficiency, Chronic
;
Renin-Angiotensin System
2.Arthroscopic Treatment of Symptomatic Discoid Meniscus in Children.
Namyong CHOI ; Sukku HAN ; Haeseok KO ; Sungjin PARK ; Hyungkuk CHUNG ; Inju LEE
Journal of the Korean Knee Society 1998;10(2):223-228
We retrospectively reviewed the results of nine children who were less than sixteen years old and in whom partial or total arthroscopic meniscectomy was performed for symptomatic discoid meniscus in eleven knees between March 1991 and February 1997. On arthroscopic findings, there were two complete and eight incomplete type of lateral discoid menisci and one medial discoid meniscus. Among eleven cases, partial meniscectomy was performed in seven and total meniscectomy in four. The average duration of follow-up was two and a half years (range, one to five years). In this study, arthroscopic total meniscectomy was superior to partial meniscectomy for a symptomatic discoid meniscus including pain, click and locking in children. Therefore, arthroscopic meniscectomy may offer the best prognosis following accurate diagnosis in children.
Child*
;
Diagnosis
;
Follow-Up Studies
;
Humans
;
Knee
;
Prognosis
;
Retrospective Studies
3.Urate Transporters in the Kidney: What Clinicians Need to Know
Electrolytes & Blood Pressure 2021;19(1):1-9
Urate is produced in the liver by the degradation of purines from the diet and nucleotide turnover and excreted by the kidney and gut. The kidney is the major route of urate removal and has a pivotal role in the regulation of urate homeostasis. Approximately 10% of the glomerular filtered urate is excreted in the urine, and the remainder is reabsorbed by the proximal tubule. However, the transport of urate in the proximal tubule is bidirectional: reabsorption and secretion. Thus, an increase in reabsorption or a decrease in secretion may induce hyperuricemia.In contrast, a decrease in reabsorption or an increase in secretion may result in hyperuricosuria. In the proximal tubule, urate reabsorption is mainly mediated by apical URAT1 (SLC22A12) and basolateral GLUT9 (SLC2A9) transporter. OAT4 (SLC22A11) also acts in urate reabsorption in the apical membrane, and its polymorphism is associated with the risk of hyperuricemia. Renal hypouricemia is caused by SLC22A12 or SLC2A9 loss-of-function mutations, and it may be complicated by exercise-induced acute kidney injury. URAT1 and GLUT9 are also drug targets for uricosuric agents. Sodium-glucose cotransporter inhibitors may induce hyperuricosuria by inhibiting GLUT9b located in the apical plasma membrane. Urate secretion is mediated by basolateral OAT1 (SLC22A6) and OAT3 (SLC22A8) and apical ATP-binding cassette super-family G member 2 (>ABCG2), NPT1 (SLC17A1), and NPT4 (SLC17A3) transporter in the proximal tubule. NPT1 and NPT4 may be key players in renal urate secretion in humans, and deletion of SLC22A6 and SLC22A8 in mice leads to decreased urate excretion. Dysfunctional variants of >ABCG2 inhibit urate secretion from the gut and kidney and may cause gout. In summary, the net result of urate transport in the proximal tubule is determined by the dominance of transporters between reabsorption (URAT1, OAT4, and GLUT9) and secretion (ABCG2, NPT1, NPT4, OAT1, and OAT3).
4.US28, a Virally-Encoded GPCR as an Antiviral Target for Human Cytomegalovirus Infection.
Sungjin LEE ; Yoon Hee CHUNG ; Choongho LEE
Biomolecules & Therapeutics 2017;25(1):69-79
Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.
Biology
;
Carcinogenesis
;
Cytomegalovirus Infections*
;
Cytomegalovirus*
;
Genome
;
Herpesviridae
;
Humans*
5.What is the Optimal Period of Observation after Percutaneous Renal Biopsy?.
Sungjin CHUNG ; Seok Joon SHIN
Korean Journal of Nephrology 2011;30(5):439-442
No abstract available.
6.Role of Peroxisome Proliferator-Activated Receptor alpha in Diabetic Nephropathy.
Sungjin CHUNG ; Cheol Whee PARK
Diabetes & Metabolism Journal 2011;35(4):327-336
With a developing worldwide epidemic of diabetes mellitus, the renal complications associated with diabetes have become a serious health concern. Primary therapy for treating diabetic nephropathy is a multifactorial process. Peroxisome proliferator-activated receptor alpha (PPARalpha) agonists have been used primarily in clinical practice for the treatment of dyslipidemia and insulin resistance. Given that PPARalpha expression and regulation of metabolic pathways are involved in oxidative stress, inflammation, blood pressure regulation, and the renin-angiotensin aldosterone system, PPARalpha likely influences the development and pathogenesis of diabetic nephropathy via indirect effects on glucose and lipid homeostasis and also by direct action on the kidneys. These findings suggest that PPARalpha may become an important therapeutic target for treating diabetic renal complications.
Aldosterone
;
Blood Pressure
;
Diabetes Mellitus
;
Diabetic Nephropathies
;
Dyslipidemias
;
Glucose
;
Homeostasis
;
Inflammation
;
Insulin Resistance
;
Kidney
;
Metabolic Networks and Pathways
;
Oxidative Stress
;
Peroxisomes
;
PPAR alpha
7.Intrarenal Mechanisms of Sodium-Glucose Cotransporter-2 Inhibitors on Tubuloglomerular Feedback and Natriuresis
Eun Sil KOH ; Gheun-Ho KIM ; Sungjin CHUNG
Endocrinology and Metabolism 2023;38(4):359-372
When sodium-glucose cotransporter-2 (SGLT2) inhibitors were first introduced a decade ago, no one expected them to have substantial effects beyond their known glucose-lowering effects, until the emergence of evidence of their robust renal and cardiovascular benefits showing that they could attenuate progression of kidney disease, irrespective of diabetes, as well as prevent the development of acute kidney injury. Still, the precise and elaborate mechanisms underlying the major organ protection of SGLT2 inhibitors remain unclear. SGLT2 inhibitors inhibit the reabsorption of sodium and glucose in the proximal tubule of the kidney and then recovers tubuloglomerular feedback, whereby SGLT2 inhibitors reduce glomerular hyperfiltration. This simple demonstration of their beneficial effects has perplexed experts in seeking more plausible and as yet undisclosed explanations for the whole effects of SGLT2 inhibitors, including metabolism reprogramming and the modulation of hypoxia, inflammation, and oxidative stress. Given that the renal benefits of SGLT2 inhibitors in patients with kidney disease but without diabetes were comparable to those seen in patients with diabetes, it may be reasonable to keep the emphasis on their hemodynamic actions. In this context, the aim of the present review is to provide a comprehensive overview of renal hemodynamics in individuals with diabetes who are treated with SGLT2 inhibitors, with a focus on natriuresis associated with the regulation of tubuloglomerular feedback and potential aquaresis. Throughout the discussion of alterations in renal sodium and water transports, particular attention will be given to the potential enhancement of adenosine and its receptors following SGLT2 inhibition.
8.Histological Assessment and Interobserver Agreement in Major Pathologic Response for Non–Small Cell Lung Cancer with Neoadjuvant Therapy
Sungjin KIM ; Jeonghyo LEE ; Jin-Haeng CHUNG
Cancer Research and Treatment 2025;57(2):401-411
Purpose:
Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction.
Materials and Methods:
This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images.
Results:
Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012).
Conclusion
While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.
9.Histological Assessment and Interobserver Agreement in Major Pathologic Response for Non–Small Cell Lung Cancer with Neoadjuvant Therapy
Sungjin KIM ; Jeonghyo LEE ; Jin-Haeng CHUNG
Cancer Research and Treatment 2025;57(2):401-411
Purpose:
Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction.
Materials and Methods:
This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images.
Results:
Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012).
Conclusion
While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.
10.Histological Assessment and Interobserver Agreement in Major Pathologic Response for Non–Small Cell Lung Cancer with Neoadjuvant Therapy
Sungjin KIM ; Jeonghyo LEE ; Jin-Haeng CHUNG
Cancer Research and Treatment 2025;57(2):401-411
Purpose:
Major pathologic response (MPR), defined as ≤ 10% of residual viable tumor (VT), is a prognostic factor in non–small cell lung cancer (NSCLC) after neoadjuvant therapy. This study evaluated interobserver reproducibility in assessing MPR, compared area-weighted and unweighted VT (%) calculation, and determined optimal VT (%) cutoffs across histologic subtypes for survival prediction.
Materials and Methods:
This retrospective study included 108 patients with NSCLC who underwent surgical resection after neoadjuvant chemotherapy or chemoradiation at Seoul National University Bundang Hospital between 2009-2018. Three observers with varying expertise independently assessed tumor bed and VT (%) based on digital whole-slide images.
Results:
Reproducibility in tumor bed delineation was reduced in squamous cell carcinoma (SqCC) with smaller tumor bed, although overall concordance was high (Dice coefficient, 0.96; intersection-over-union score, 0.92). Excellent agreement was achieved for VT (%) (intraclass correlation coefficient=0.959) and MPR using 10% cutoff (Fleiss’ kappa=0.911). Shifting between area-weighted and unweighted VT (%) showed only one case differing in MPR status out of 81 cases. The optimal cutoff was 10% for both adenocarcinoma (ADC) and SqCC. MPR+ was observed in 18 patients (17%), with SqCC showing higher MPR+ rates (p=0.044), lower VT (%) (p < 0.001), and better event-free survival (p=0.015) than ADC. MPR+ significantly improved overall survival (p=0.023), event-free survival (p=0.001), and lung cancer-specific survival (p=0.012).
Conclusion
While MPR assessment demonstrated robust reproducibility with minimal impact from the tumor bed, attention is warranted when evaluating smaller tumor beds in SqCC. A 10% cutoff reliably predicted survival across histologic subtypes with higher interobserver reproducibility.