1.DNA Methylation-Based Age Estimation in the Forensic Field.
Ja Hyun AN ; Kyoung Jin SHIN ; Ajin CHOI ; Woo Ick YANG ; Hwan Young LEE
Korean Journal of Legal Medicine 2013;37(1):1-8
The estimation of age is an important issue in forensic science, and the forensic community has attempted many times to establish methods for solving this issue. Aging leads to alterations in tissues and organs at the molecular level. These alterations at the molecular level may aid forensic scientists to estimate the age of a living person or a dead body. Initially, the focus was on the genetic components of aging, but recently, epigenetic mechanisms have emerged as the key contributors to the alterations in genome structure and function that accompany aging. In particular, DNA methylation is one of the best-understood mechanisms, and it has been suggested as a promising biomarker for age estimation in many studies. In this review, we summarize the recent studies on age-associated DNA methylation changes in different tissues and discuss its possible and practical applications in forensics.
Aging
;
DNA
;
DNA Methylation
;
Epigenomics
;
Forensic Sciences
;
Genome
;
Humans
2.Korean clinical practice guidelines for preventing the transmission of infections in hemodialysis facilities.
Hayne Cho PARK ; Young Ki LEE ; Kyung Don YOO ; Hee Jung JEON ; Seung Jun KIM ; Ajin CHO ; Jacob LEE ; Yang Gyun KIM ; Sang Ho LEE ; Sang Oh LEE
Kidney Research and Clinical Practice 2018;37(1):8-19
Patients receiving hemodialysis are vulnerable to infectious diseases due to their impaired immunity and high risk of exposure to pathogens. To protect patients, staff, and visitors from potential infections, each hemodialysis unit should establish and follow standard infection control and prevention measures. Therefore, clinical practice guidelines were developed by a working group of nephrologists and infection control specialists to provide evidence-based guidance for dialysis physicians and nurses, with the aim of preventing infection transmission and controlling infection sources in hemodialysis facilities. The areas of infection control covered by these guidelines include standard precautions, isolation strategies, vascular access, water treatment, cleaning/disinfecting/sterilizing, and vaccination. This special report summarizes the key recommendations from the Korean clinical practice guidelines for preventing the transmission of infections in hemodialysis facilities.
Communicable Diseases
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Dialysis
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Disease Transmission, Infectious
;
Humans
;
Infection Control
;
Renal Dialysis*
;
Specialization
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Vaccination
;
Water Purification
3.Essential Role of Protein Arginine Methyltransferase 1 in Pancreas Development by Regulating Protein Stability of Neurogenin 3
Kanghoon LEE ; Hyunki KIM ; Joonyub LEE ; Chang Myung OH ; Heein SONG ; Hyeongseok KIM ; Seung Hoi KOO ; Junguee LEE ; Ajin LIM ; Hail KIM
Diabetes & Metabolism Journal 2019;43(5):649-658
BACKGROUND: Protein arginine methyltransferase 1 (PRMT1) is a major enzyme responsible for the formation of methylarginine in mammalian cells. Recent studies have revealed that PRMT1 plays important roles in the development of various tissues. However, its role in pancreas development has not yet been elucidated. METHODS: Pancreatic progenitor cell-specific Prmt1 knock-out (Prmt1 PKO) mice were generated and characterized for their metabolic and histological phenotypes and their levels of Neurog3 gene expression and neurogenin 3 (NGN3) protein expression. Protein degradation assays were performed in mPAC cells. RESULTS: Prmt1 PKO mice showed growth retardation and a severely diabetic phenotype. The pancreatic size and β-cell mass were significantly reduced in Prmt1 PKO mice. Proliferation of progenitor cells during the secondary transition was decreased and endocrine cell differentiation was impaired. These defects in pancreas development could be attributed to the sustained expression of NGN3 in progenitor cells. Protein degradation assays in mPAC cells revealed that PRMT1 was required for the rapid degradation of NGN3. CONCLUSION: PRMT1 critically contributes to pancreas development by destabilizing the NGN3 protein.
Animals
;
Diabetes Mellitus
;
Endocrine Cells
;
Gene Expression
;
Islets of Langerhans
;
Mice
;
Pancreas
;
Phenotype
;
Protein Stability
;
Protein-Arginine N-Methyltransferases
;
Proteolysis
;
Stem Cells
4.Seropositive rate of the anti-hepatitis A immunoglobulin G antibody in maintenance hemodialysis subjects from two hospitals in Korea
Hyunsuk KIM ; Jiwon RYU ; Young Ki LEE ; Myung Jin CHOI ; Ajin CHO ; Ja Ryong KOO ; Sae Yun BAIK ; Eun Hee LEE ; Jong Woo YOON ; Jung Woo NOH
The Korean Journal of Internal Medicine 2019;34(6):1297-1303
BACKGROUND/AIMS:
Hepatitis A virus (HAV) is a self-limiting infectious disease, but 1% of subjects develop fulminant hepatitis. The prevalence of the anti-HAV immunoglobulin G (IgG) antibody in hemodialysis subjects in Korea remains unknown. The purpose of this study was to describe and compare the seropositive rate of anti-HAV antibody among hemodialysis subjects in two hospitals according to age group.
METHODS:
A total of 170 hemodialysis subjects were evaluated for the seropositive rate of the anti-HAV IgG antibody and its titer.
RESULTS:
Of the 170 maintenance hemodialysis subjects in two hospitals (Kangnam 92 vs. Chuncheon 78), 79 (46.5%) were male. The mean age was 53.2 years old, and 94.1% of the subjects were over 40 years old. The median vintage of hemodialysis was 29.0 months. Anti-HAV antibody was found in 163 subjects (95.9%), with no significant difference between the two areas (Kangnam 97.8% [n = 90] vs. Chuncheon 93.6% [n = 73]). Subjects younger than 40 years old showed a seropositive rate of 50%, while the seropositive rate increased with age for subjects aged 40 or older (p for trend < 0.001). Seropositive subjects from Kangnam showed a higher anti-HAV antibody titer than those from Chuncheon (median: Kangnam 14.2 vs. Chuncheon 11.7). Only age influenced seropositivity. The only factor that influenced the antibody level was the location of hospital (p < 0.001).
CONCLUSIONS
The seropositive rate of the anti-HAV antibody in hemodialysis subjects was 95%, which is similar to findings in the general population. Active immunization against hepatitis A is strongly recommended for hemodialysis subjects under 40 years of age after anti-HAV testing.
5.Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?
Hayne Cho PARK ; Do Hyoung KIM ; AJin CHO ; Bo Yeon KIM ; Miri LEE ; Gui Ok KIM ; Jinseog KIM ; Young-Ki LEE
Kidney Research and Clinical Practice 2024;43(5):671-679
Hemodialysis (HD) patients have a higher mortality rate compared to the general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of the general population as well as HD patients from other countries. Methods: Baseline data were retrieved from HD quality assessment data from 2015. Among the patients over 30 years old who were alive at the beginning of 2016 (20,304 males and 14,264 females), a total of 22,078 (12,621 males and 9,457 females) were still alive at the end of 2021 while 12,490 (7,683 males and 4,807 females) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in 2-year increments. Results: The remaining life expectancies for 60-year-old patients were 11.64 years for males and 14.64 years for females. The average remaining life expectancies of the HD population were only about half of the general population. Diabetic patients demonstrated shorter life expectancy compared to patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and the United States. Conclusion: The HD population shows a shorter life expectancy compared to the general population. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology on improved survival rates among the HD population.
6.Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?
Hayne Cho PARK ; Do Hyoung KIM ; AJin CHO ; Bo Yeon KIM ; Miri LEE ; Gui Ok KIM ; Jinseog KIM ; Young-Ki LEE
Kidney Research and Clinical Practice 2024;43(5):671-679
Hemodialysis (HD) patients have a higher mortality rate compared to the general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of the general population as well as HD patients from other countries. Methods: Baseline data were retrieved from HD quality assessment data from 2015. Among the patients over 30 years old who were alive at the beginning of 2016 (20,304 males and 14,264 females), a total of 22,078 (12,621 males and 9,457 females) were still alive at the end of 2021 while 12,490 (7,683 males and 4,807 females) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in 2-year increments. Results: The remaining life expectancies for 60-year-old patients were 11.64 years for males and 14.64 years for females. The average remaining life expectancies of the HD population were only about half of the general population. Diabetic patients demonstrated shorter life expectancy compared to patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and the United States. Conclusion: The HD population shows a shorter life expectancy compared to the general population. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology on improved survival rates among the HD population.
7.Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?
Hayne Cho PARK ; Do Hyoung KIM ; AJin CHO ; Bo Yeon KIM ; Miri LEE ; Gui Ok KIM ; Jinseog KIM ; Young-Ki LEE
Kidney Research and Clinical Practice 2024;43(5):671-679
Hemodialysis (HD) patients have a higher mortality rate compared to the general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of the general population as well as HD patients from other countries. Methods: Baseline data were retrieved from HD quality assessment data from 2015. Among the patients over 30 years old who were alive at the beginning of 2016 (20,304 males and 14,264 females), a total of 22,078 (12,621 males and 9,457 females) were still alive at the end of 2021 while 12,490 (7,683 males and 4,807 females) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in 2-year increments. Results: The remaining life expectancies for 60-year-old patients were 11.64 years for males and 14.64 years for females. The average remaining life expectancies of the HD population were only about half of the general population. Diabetic patients demonstrated shorter life expectancy compared to patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and the United States. Conclusion: The HD population shows a shorter life expectancy compared to the general population. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology on improved survival rates among the HD population.
8.Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?
Hayne Cho PARK ; Do Hyoung KIM ; AJin CHO ; Bo Yeon KIM ; Miri LEE ; Gui Ok KIM ; Jinseog KIM ; Young-Ki LEE
Kidney Research and Clinical Practice 2024;43(5):671-679
Hemodialysis (HD) patients have a higher mortality rate compared to the general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of the general population as well as HD patients from other countries. Methods: Baseline data were retrieved from HD quality assessment data from 2015. Among the patients over 30 years old who were alive at the beginning of 2016 (20,304 males and 14,264 females), a total of 22,078 (12,621 males and 9,457 females) were still alive at the end of 2021 while 12,490 (7,683 males and 4,807 females) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in 2-year increments. Results: The remaining life expectancies for 60-year-old patients were 11.64 years for males and 14.64 years for females. The average remaining life expectancies of the HD population were only about half of the general population. Diabetic patients demonstrated shorter life expectancy compared to patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and the United States. Conclusion: The HD population shows a shorter life expectancy compared to the general population. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology on improved survival rates among the HD population.
9.Two cases of idiopathic membranous nephropathy treated with rituximab.
Jae Young YOON ; Seung Tae HAN ; Ajin CHO ; Hye Ryoun JANG ; Jung Eun LEE ; Wooseong HUH ; Dae Joong KIM ; Ha Young OH ; Yoon Goo KIM
Kidney Research and Clinical Practice 2013;32(3):138-141
Idiopathic membranous nephropathy is a common cause of nephrotic syndrome, and has been reported as a cause of idiopathic primary glomerulonephropathy in up to 90% of patients. However, the treatment options remain controversial. We report two cases of idiopathic membranous nephropathy that were treated with rituximab. A 54-year-old man and a 64-year old man were admitted for rituximab therapy. They had previously been treated with combinations of immunosuppressive agents including cyclophosphamide, cyclosporine, mycophenolate, and steroids. However, the patients' heavy proteinuria was not resolved. Both patients received rituximab therapy, 2 weeks apart. After several months of follow-up and a second round of rituximab treatment for each patient, their proteinuria decreased and partial remission of disease was achieved in both patients.
Antibodies, Monoclonal, Murine-Derived
;
Cyclophosphamide
;
Cyclosporine
;
Follow-Up Studies
;
Glomerulonephritis, Membranous*
;
Humans
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Immunosuppressive Agents
;
Middle Aged
;
Nephrotic Syndrome
;
Proteinuria
;
Steroids
;
Rituximab
10.Rac-mediated actin remodeling and myosin II are involved in KATP channel trafficking in pancreatic beta-cells.
Young Eun HAN ; Ajin LIM ; Sun Hyun PARK ; Sunghoe CHANG ; Suk Ho LEE ; Won Kyung HO
Experimental & Molecular Medicine 2015;47(10):e190-
AMP-activated protein kinase (AMPK) is a metabolic sensor activated during metabolic stress and it regulates various enzymes and cellular processes to maintain metabolic homeostasis. We previously reported that activation of AMPK by glucose deprivation (GD) and leptin increases KATP currents by increasing the surface levels of KATP channel proteins in pancreatic beta-cells. Here, we show that the signaling mechanisms that mediate actin cytoskeleton remodeling are closely associated with AMPK-induced KATP channel trafficking. Using F-actin staining with Alexa 633-conjugated phalloidin, we observed that dense cortical actin filaments present in INS-1 cells cultured in 11 mM glucose were disrupted by GD or leptin treatment. These changes were blocked by inhibiting AMPK using compound C or siAMPK and mimicked by activating AMPK using AICAR, indicating that cytoskeletal remodeling induced by GD or leptin was mediated by AMPK signaling. AMPK activation led to the activation of Rac GTPase and the phosphorylation of myosin regulatory light chain (MRLC). AMPK-dependent actin remodeling induced by GD or leptin was abolished by the inhibition of Rac with a Rac inhibitor (NSC23766), siRac1 or siRac2, and by inhibition of myosin II with a myosin ATPase inhibitor (blebbistatin). Immunocytochemistry, surface biotinylation and electrophysiological analyses of KATP channel activity and membrane potentials revealed that AMPK-dependent KATP channel trafficking to the plasma membrane was also inhibited by NSC23766 or blebbistatin. Taken together, these results indicate that AMPK/Rac-dependent cytoskeletal remodeling associated with myosin II motor function promotes the translocation of KATP channels to the plasma membrane in pancreatic beta-cells.
AMP-Activated Protein Kinases/metabolism
;
Actins/*metabolism
;
Animals
;
Cell Line
;
Glucose/metabolism
;
Insulin-Secreting Cells/*metabolism
;
KATP Channels/*metabolism
;
Leptin/metabolism
;
Myosin Type II/*metabolism
;
Phosphorylation
;
Rats
;
*Signal Transduction
;
rac GTP-Binding Proteins/*metabolism