A comparative study of epidemiological characteristics, treatment outcomes, and mortality among patients undergoing hemodialysis by health insurance types: data from the Korean Renal Data System.

Background: The prevalence of end-stage renal disease (ESRD) requiring dialysis has progressively increased. Therefore, to achieve financial stability by managing the increasing numbers of patients undergoing hemodialysis (HD), a fixed-payment system was introduced in 2001 for medical aid (MA) beneficiaries receiving HD in Korea. Methods: We identified patients in the Korean Renal Data System that received HD between 2001 and 2017 and stratified them into the following two groups: the National Health Insurance (NHI) and MA groups. Then, we compared the two groups that differed in demographic characteristics, the treatment process and outcomes, and mortality based on health insurance type. Results: Among 52,574 patients, the number of patients aged 65 years or older, hypertension was higher in the NHI group, but diabetes was higher in the MA group. Additionally, the MA group had more weekly dialysis sessions, and expensive drugs tended to be used less frequently. Regarding treatment outcomes, including laboratory test results, the MA group achieved significantly lower goals than the NHI group (p < 0.001). Furthermore, the mortality rate per 1,000 persons was 31 and 27 in the MA and NHI groups, respectively, and the mortality rate ratio was 1.2 (95% confidence interval [CI], 1.076-1.230). Moreover, the hazard ratio for mortality was 1.39 (95% CI, 1.30-1.49, p < 0.001) after adjusting for age, sex, causes of ESRD, and comorbidities. Conclusion: There were significant differences in the treatment and mortality indicators between the groups. Therefore, policy support should be strengthened to provide better medical services to MA beneficiaries undergoing HD.

Usefulness of continuous glucose monitoring of blood glucose control in patients with diabetes undergoing hemodialysis: A pilot study.

Background: Blood glucose stability has recently been considered important in the treatment of diabetes. Both hypoglycemia and hyperglycemia can frequently occur in patients with diabetes undergoing hemodialysis. This study aimed to determine the usefulness of continuous glucose monitoring (CGM) for glycemic control and glycemic variability stabilization in patients with diabetes undergoing hemodialysis. Materials and methods: Eighteen patients aged ≥18 years with type 1 or 2 diabetes and ≥3 months on hemodialysis at the Eulji Medical Center, Daejeon, Republic of Korea between November 2021 and May 2022 were included. Patients underwent 7 days CGM twice: the baseline study period (T0) and the follow-up study period (T1), at a 12 weeks interval. Physicians modified the treatment strategy according to the T0 results, and then patients conducted T1. As indicators of glycemic control, the mean glucose levels, glycated hemoglobin A1c (HbA1c), and time in range were measured. As indicators of glycemic variability, standard deviation (SD) and % coefficient variation (%CV) were measured. Results: Data from 18 patients were analyzed. The mean glucose levels, HbA1c, SD, and %CV improved in T1 compared to T0 (P < 0.05). During T0, the mean glucose level was significantly lower on a day with hemodialysis than on a day without (P < 0.05), and SD and %CV were significantly higher on a day with hemodialysis than on a day without (P < 0.05). After the physicians modified the treatment according to the T0 results, there were no differences in the mean glucose levels, SD, and %CV between days with and without hemodialysis during T1. Conclusion: Continuous glucose monitoring could be a promising tool for individualizing treatment strategies in patients with diabetes undergoing hemodialysis.

Microstructure, Tensile, and Fatigue Properties of Large-Scale Austenitic Lightweight Steel.

High-Mn lightweight steel, Fe-0.9C-29Mn-8Al, was manufactured using steelmaking, ingot-making, forging, and rolling processes. After the final rolling process, a typical austenite single phase was observed on all sides of the thick plate. The microstructural changes after annealing and aging heat-treatments were observed, using optical and transmission electron microscopy. The annealed coupon exhibited a typical austenite single phase, including annealing twins in several grains; the average grain size was 153 µm. After aging heat treatment, κ-carbide was observed within the grains and on the grain boundaries. Additionally, the effect of aging heat treatment on the mechanical properties was analyzed, using a tensile test. The fine κ-carbide that precipitated within the grains in the aged coupon improved the 0.2% offset yield and the tensile stresses, as compared to the as-annealed coupon. To estimate the applicability of high-Mn lightweight steel for low-pressure (LP) steam turbine blades, a low-cycle fatigue (LCF) test was carried out at room temperature. At a total strain amplitude of 0.5 to 1.2%, the LCF life of high-Mn lightweight steel was approximately three times that of 12% Cr steel, which is used in commercial LP steam turbine blades. The LCF behavior of high-Mn lightweight steel followed the Coffin-Manson equation. The LCF life enhancement in the high-Mn lightweight steel results from the planar dislocation gliding behavior.

Prediction of Metal Additively Manufactured Surface Roughness Using Deep Neural Network.

In recent years, manufacturing industries (e.g., medical, aerospace, and automobile) have been changing their manufacturing process to small-quantity batch production to flexibly cope with fluctuations in demand. Therefore, many companies are trying to produce products by introducing 3D printing technology into the manufacturing process. The 3D printing process is based on additive manufacturing (AM), which can fabricate complex shapes and reduce material waste and production time. Although AM has many advantages, its product quality is poor compared to conventional manufacturing systems. This study proposes a methodology to improve the quality of AM products based on data analysis. The targeted quality of AM is the surface roughness of the stacked wall. Surface roughness is one of the important quality indicators and can cause short product life and poor structure performance. To control the surface roughness, the resultant surface roughness needs to be predicted in advance depending on the process parameters. Various analysis methods such as data pre-processing and deep neural networks (DNN) combined with sensor data are used to predict surface roughness in the proposed methodology. The proposed methodology is applied to field data from operated wire + arc additive manufacturing (WAAM), and the analysis result shows its effectiveness, with a mean absolute percentage error (MAPE) of 1.93%.

Radiolucent Pure Matrix Stones on Computed Tomography Scan, Arising in Patient with Type I Diabetes and Chronic Kidney Disease: A Case Report.

Kidney matrix stones are a rare form of calculi, which are challenging to diagnose. Matrix stones consist of a proteinaceous material which has a radiolucent appearance that might be overlooked on imaging. Recently, endourological intervention has been the standard treatment method for matrix stones. We report a case of urinary matrix stones in a patient with type 1 diabetes mellitus and chronic kidney disease, in whom the stones formed into a pure matrix and were not visualized in the computed tomography scan. The stones were found after additional work-up, and they were managed using a transureteral stone basket, not through endourological intervention.

An Updated Meta-Analysis of Remote Blood Pressure Monitoring in Urban-Dwelling Patients with Hypertension.

Following the coronavirus disease-2019 pandemic, this study aimed to evaluate the overall effects of remote blood pressure monitoring (RBPM) for urban-dwelling patients with hypertension and high accessibility to healthcare and provide updated quantitative summary data. Of 2721 database-searched articles from RBPM's inception to November 2020, 32 high-quality studies (48 comparisons) were selected as primary data for synthesis. A meta-analysis was undertaken using a random effects model. Primary outcomes were changes in office systolic blood pressure (SBP) and diastolic blood pressure (DBP) following RBPM. The secondary outcome was the BP control rate. Compared with a usual care group, there was a decrease in SBP and DBP in the RBPM group (standardized mean difference 0.507 (95% confidence interval [CI] 0.339-0.675, p < 0.001; weighted mean difference [WMD] 4.464 mmHg, p < 0.001) and 0.315 (CI 0.209-0.422, p < 0.001; WMD 2.075 mmHg, p < 0.001), respectively). The RBPM group had a higher BP control rate based on a relative ratio (RR) of 1.226 (1.107-1.358, p < 0.001). RBPM effects increased with increases in city size and frequent monitoring, with decreases in intervention duration, and in cities without medically underserved areas. RBPM is effective in reducing BP and in achieving target BP levels for urban-dwelling patients with hypertension.

Strain hardening recovery mediated by coherent precipitates in lightweight steel.

We investigated the effect of κ-carbide precipitates on the strain hardening behavior of aged Fe-Mn-Al-C alloys by microstructure analysis. The κ-carbides-strengthened Fe-Mn-Al-C alloys exhibited a superior strength-ductility balance enabled by the recovery of the strain hardening rate. To understand the relation between the κ-carbides and strain hardening recovery, dislocation gliding in the aged alloys during plastic deformation was analyzed through in situ tensile transmission electron microscopy (TEM). The in situ TEM results confirmed the particle shearing mechanism leads to planar dislocation gliding. During deformation of the 100 h-aged alloy, some gliding dislocations were strongly pinned by the large κ-carbide blocks and were prone to cross-slip, leading to the activation of multiple slip systems. The abrupt decline in the dislocation mean free path was attributed to the activation of multiple slip systems, resulting in the rapid saturation of the strain hardening recovery. It is concluded that the planar dislocation glide and sequential activation of slip systems are key to induce strain hardening recovery in polycrystalline metals. Thus, if a microstructure is designed such that dislocations glide in a planar manner, the strain hardening recovery could be utilized to obtain enhanced mechanical properties of the material.

Direct observation of dislocation plasticity in high-Mn lightweight steel by in-situ TEM.

To gain the fundamental understanding of deformation mechanisms in an aluminum-containing austenitic high-Mn steel (Fe-32Mn-8.9Al-0.78 C (wt.%)), in-situ straining transmission electron microscopy (TEM) analysis is conducted. The in-situ observation during the deformation demonstrates that the plastic deformation is accommodated by the pronounced planar dislocation gliding followed by the formation of slip bands (SBs) and highly dense dislocation walls (HDDWs). Experimental evidences of the glide plane softening can be obtained from the interaction between the gliding perfect dislocations and the L'12 ordered precipitates in the austenite matrix. Furthermore, the observation of the localized cross-slip of dislocations at the slip band intersections enables to understand why slip bands are extensively developed without mutual obstructions between the slip bands. The enhanced strain hardening rate of the aluminum-containing austenitic high-Mn steels can be attributed to the pronounced planar dislocation glides followed by formation of extensive slip band which prevent premature failure by suppressing strain localization.

Nrf2-Heme Oxygenase-1 Attenuates High-Glucose-Induced Epithelial-to-Mesenchymal Transition of Renal Tubule Cells by Inhibiting ROS-Mediated PI3K/Akt/GSK-3ß Signaling.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) is thought to play a significant role in the advancement to chronic kidney disease and contributes to the deposition of extracellular matrix proteins and renal fibrosis relating to diabetic nephropathy. METHOD: We studied the effect of Nrf2-HO-1 signaling on high-glucose- (HG-) induced EMT in normal human tubular epithelial cells, that is, HK2 cells. In short, we treated HK2 cells with HG and sulforaphane (SFN) as an Nrf2 activator. EMT was evaluated by the expression activity of the epithelial marker E-cadherin and mesenchymal markers such as vimentin and fibronectin. RESULTS: Exposure of HK2 cells to HG (60 mM) activated the expression of vimentin and fibronectin but decreased E-cadherin. Treatment of HK2 cells with SFN caused HG-induced attenuation in EMT markers with activated Nrf2-HO-1. We found that SFN decreased HG-induced production of reactive oxygen species (ROS), phosphorylation of PI3K/Akt at serine 473, and inhibitory phosphorylation of serine/threonine kinase glycogen synthase kinase-3ß (GSK-3ß) at serine 9. Subsequently, these signaling led to the downregulation of the Snail-1 transcriptional factor and the recovery of E-cadherin. CONCLUSION: The present study suggests that Nrf2-HO-1 signaling has an inhibitory role in the regulation of EMT through the modulation of ROS-mediated PI3K/Akt/GSK-3ß activity, highlighting Nrf2-HO-1 and GSK-3ß as potential therapeutic targets in diabetic nephropathy.

Nrf2-Heme oxygenase-1 modulates autophagy and inhibits apoptosis triggered by elevated glucose levels in renal tubule cells.

BACKGROUND: Autophagy is a highly balanced process in which lysosomes remove aged and damaged organelles and cellular proteins. Autophagy is essential to maintain homeostasis in the kidneys. METHODS: Using human renal tubule cells HK-2, we assessed the impact of high glucose (HG) on autophagy. We also evaluated the capability of sulforaphane (SFN) to protect the HK-2 cells from HG-induced apoptosis by modulating autophagy. RESULTS: SFN modulated autophagy and decreased apoptosis in the HK-2 cells that were cultured in 250 mM glucose medium for two days. The reactive oxygen species (ROS) levels increased, as expected, in the cells cultured in the 250 mM glucose medium. However, the SFN decreased the ROS levels in the HK-2 cells. The overexpression of heme oxygenase-1 (HO-1) by SFN decreased the expression of LC3 and beclin-1. LC3 and beclin-1 were involved in the downregulation of caspase-3 that was observed in the HG-induced cells. CONCLUSION: The activation of nuclear factor E2-related factor 2 (Nrf2)-HO-1 inhibited ROS expression and subsequently attenuated autophagy and cell apoptosis after HG injury was decreased. HG injury led to the activation of autophagy and HO-1 in order to combat oxidative stress and protect against cell apoptosis. Therefore, HO-1 activation can prevent ROS development and oxidative stress during HG injury, which considerably decreases autophagy and apoptosis.

Concurrent renal dysfunction with ischemic heart disease is an important determinant for cardiac and cerebrovascular mortality in patients on chronic digoxin therapy for atrial fibrillation.

BACKGROUND: Major adverse cardiac and cerebrovascular events (MACCEs) are main concerns in patients with atrial fibrillation (AF); however, factors affecting MACCEs remain inconclusive in AF patients chronically treated with digoxin. We investigated the major clinical determinants for fatal MACCEs in AF patients treated with digoxin over a 10-year follow-up period. METHODS: We analyzed a retrospective cohort of 1,480 AF patients at Eulji University Hospital, Daejeon, South Korea from March 2004 to August 2015. Among this population, 402 consecutive patients receiving chronic digoxin therapy were selected for the study. Data for electrocardiography, medication history, laboratory values including the serum digoxin concentration (SDC) and fatal MACCEs were collected. All data were divided and compared between groups based on the occurrence of MACCEs. RESULTS: The overall incidence of fatal MACCEs among the 402 digoxin-treated AF patients (age, 68 ± 11 years; male, 40.3%) was 12.1%. These fatalities resulted from heart failure (46.1%), fatal stroke (26.9%), fatal myocardial infarction (15.3%) and sudden cardiac death (5.7%). A higher prevalence of diabetes, pre-existing ischemic heart disease (IHD), lower estimated glomerular filtration rate (eGFR), higher SDC, and junctional bradycardia were more frequently observed in patients with MACCEs compared to those without MACCEs. Multivariable analysis showed that an eGFR of ≤ 60 mL/min/1.73 m2 and pre-existing IHD had a hazard ratio of 3.35 and a confidence interval of 1.64-6.87 (P < 0.001) for fatal MACCEs. CONCLUSION: Chronic kidney disease stage III-V with pre-existing IHD is significantly associated with increased cardiac and cerebrovascular mortality in AF patients with chronic digoxin use.

Highly conductive and environmentally stable gold/graphene yarns for flexible and wearable electronics.

Here, we fabricated high-performance gold/graphene yarns through a facile method by the electroless deposition of gold nanoparticles onto the surface of graphene yarns. The gold/graphene yarns are fabricated using a completely solution-based process that can be scaled up for practical applications. They possess high electrical conductivity (2.86 × 102 S cm-1) and good gravimetric specific conductivity (6.81 × 102 S cm2 g-1) as well as good reliability under 1000 bending tests with a maximum bending angle of 170° and 10 washing tests with laundry detergents. These stable conducting yarns could also be integrated into textiles and clothes in various forms to create smart fabrics and wearable devices. In addition, this facile approach is easily applicable to various graphene films and devices on soft substrates that are presently used in flexible/wearable electronics.

Treadmill exercise-induced E/e' elevation as a predictor of cardiovascular event in end-stage renal disease on peritoneal dialysis.

BACKGROUND/AIMS: Diastolic dysfunction is associated with cardiovascular (CV) events in end-stage renal disease (ESRD) on continuous ambulatory peritoneal dialysis (CAPD). However, conventional measurement of LA volume and E/e' using Doppler echocardiography has been limited to predict CV events in patients with ESRD on CAPD. METHODS: From September 2007 to September 2008, 30 consecutive patients with exertional dyspnea in ESRD on CAPD and normal systolic function was prospectively enrolled and underwent laboratory testing, coronary angiography, and treadmill exercise stress echocardiography (TESE). We divided the patients according to the presence of exercise-induced change of E/e' tissue Doppler and investigated whether this factor predicted CV events in ESRD on CAPD. RESULTS: Mean CAPD duration of all patients (70% male; mean age, 49 years) was 12 months. Patients with exercise-induced elevated E/e' (n = 12, 40%) and non-elevated E/e' (n = 18, 60%) demonstrated similar baseline characteristics. Exercise-induced elevated E/e' was predictable (cut-off value 14%, sensitivity 63%, and specificity 95%), with a hazard ratio of 1.13 (confidence interval, 1.03 to 1.24; p = 0.005), and significantly associated with CV events compared to the non-elevated E/e' group (log-rank, p = 0.007). CONCLUSIONS: Exercise-induced elevated E/e' determined using TESE might be feasible to predict CV events in patients with ESRD on CAPD.

Fibrillary glomerulonephritis combined with chronic inflammatory demyelinating polyneuropathy.

A 58-yr-old man presented with leg edema and subacute weakness of his bilateral lower extremities. Urinary and serum immunoelectrophoresis revealed the presence of lambda-type Bence Jones proteins. He was ultimately diagnosed with monoclonal gammopathy of undetermined significance (MGUS). A renal biopsy specimen showed fibrillary glomerulonephritis (FGN), which was randomly arranged as 12-20 m nonbranching fibrils in the basement membranes. Immunofluorescence studies were negative for immunoglobulin (Ig)G, IgM, IgA, C3, and kappa light chains in the capillary walls and mesangial areas. A Congo red stain for amyloid was negative. Electromyography and nerve conduction velocity examinations results were compatible with the presence of demyelinating polyneuropathy. This case showed a rare combination of FGN, without Ig deposition, and MGUS combined with chronic inflammatory demyelinating polyneuropathy (CIDP).

Effect of topical vitamin D on chronic kidney disease-associated pruritus: An open-label pilot study.

Chronic kidney disease-associated pruritus (CKD-aP) is a troublesome symptom in patients with end-stage renal disease (ESRD). Recently, vitamin D deficiency has been known to be one of the possible etiologic factors in CKD-aP. However, limited data is available on whether topical vitamin D treatment is effective for relieving CKD-aP. Therefore, the purpose of this study is to evaluate the effectiveness of topically vitamin D for CKD-aP. Twenty-three patients with CKD-aP were enrolled in a single center, open-label study. Patients were instructed to apply a topical vitamin D (calcipotriol) agent (Daivonex solution; LEO Pharma) or vehicle solution twice daily for a month. We assessed the efficacy and safety of topical vitamin D on CKD-aP using clinical and dermoscopic photographs, and questionnaires including the validated modified pruritus assessment score (VMPAS) and visual analog scale (VAS) every 2 weeks. Dry dermoscopic findings showed significant improvement of scale (dryness) on the skin of topical vitamin D-treated patients compared with those of the vehicle group. Both VMPAS and VAS were significantly decreased after 2 and 4 weeks of the topical vitamin D treatment compared with the vehicle, respectively (P < 0.05). No significant side-effects were observed. Topical vitamin D may be one of the safe and effective therapeutic candidates for CKD-aP.

Diastolic Dysfunction Induced by a High-Fat Diet Is Associated with Mitochondrial Abnormality and Adenosine Triphosphate Levels in Rats.

BACKGROUND: Obesity is well-known as a risk factor for heart failure, including diastolic dysfunction. However, this mechanism in high-fat diet (HFD)-induced obese rats remain controversial. The purpose of this study was to investigate whether cardiac dysfunction develops when rats are fed with a HFD for 10 weeks; additionally, we sought to investigate the association between mitochondrial abnormalities, adenosine triphosphate (ATP) levels and cardiac dysfunction. METHODS: We examined myocardia in Wistar rats after 10 weeks of HFD (45 kcal% fat, n=6) or standard diet (SD, n=6). Echocardiography, histomorphologic analysis, and electron microscopy were performed. The expression levels of mitochondrial oxidative phosphorylation (OXPHOS) subunit genes, peroxisome-proliferator-activated receptor γ co-activator-1α (PGC1α) and anti-oxidant enzymes were assessed. Markers of oxidative stress damage, mitochondrial DNA copy number and myocardial ATP level were also examined. RESULTS: After 10 weeks, the body weight of the HFD group (349.6±22.7 g) was significantly higher than that of the SD group (286.8±14.9 g), and the perigonadal and epicardial fat weights of the HFD group were significantly higher than that of the SD group. Histomorphologic and electron microscopic images were similar between the two groups. However, in the myocardium of the HFD group, the expression levels of OXPHOS subunit NDUFB5 in complex I and PGC1α, and the mitochondrial DNA copy number were decreased and the oxidative stress damage marker 8-hydroxydeoxyguanosine was increased, accompanied by reduced ATP levels. CONCLUSION: Diastolic dysfunction was accompanied by the mitochondrial abnormality and reduced ATP levels in the myocardium of 10 weeks-HFD-induced rats.

Heme oxygenase-1 attenuates epithelial-to-mesenchymal transition of human peritoneal mesothelial cells.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) of peritoneal mesothelial cells has been regarded as an early mechanism of peritoneal fibrosis. A substantial and rapidly growing literature indicates that HO-1 provides the provenance for pathways that can interrupt virtually all major mechanisms of tissue injury. The effects of HO-1 expression on EMT, which plays a critical role in the development of peritoneal membrane (PM) fibrosis, are unknown and its roles in peritoneal fibrosis has not been studied, yet. METHODS: A piece of human omentum obtained from consenting patients undergoing elective abdominal surgery was used for study. We treated the human peritoneal mesothelial cells (HPMCs) with high glucose solution and HO-1 inducer (hemin, 10 µmol/L). To further investigate the pure effect of HO-1 on EMT of mesothelium, gene transfer of recombinant Adenovirus-harboring human HO-1 (Adv-HO-1 gene) to HPMCs was done. RESULTS: Exposure of HPMCs to HG solution resulted in an increase of the expression of mesenchymal markers such as α-smooth muscle actin (α-SMA) and was associated with a decrease in the expression of epithelial markers, E-cadherin. HO-1 protein expression was decreased in the same situation. Treatment of HPMCs with HO-1 inducer, hemin showed a dosage-dependent amelioration of HG induced changes in markers of EMT with increase of expression of HO-1. Human HO-1 gene transfection resulted in a significant increase in HO-1 expression and ameliorated HG-induced changes in expression of E-cadherin and α-SMA. CONCLUSION: Taken together, our results suggest that HO-1 has a critical role in the modulation of peritoneal fibrosis, and, more important, the suppression of EMT. This study is the first to show the beneficial effect of HO-1 on reversing EMT in MC.

Prevalence, correlates, and comorbidity of 12-Month tobacco dependence among ever-smokers in South Korea, during 1984-2001.

The rate of dependence among ever-users of a drug indicates the risk of developing dependence once an individual has been exposed to the drug. This is the first study to investigate 12-month tobacco dependence (TD) among ever-smokers in a community-based population. Analyses were based on two national studies of representative samples aged 18-64 in 1984 (n=5,025) and in 2001 (n=6,275), conducted with household visits and face-to-face interviews. The rates of 12-month TD among ever-smokers in men showed no significant difference between 51.6% in 1984 and 50.6% in 2001. On the contrary, the rates in women significantly increased from 33.3% in 1984 to 52.8% in 2001. After adjusting for the sociodemographic variables, 'male gender' was significantly associated with 12-month TD among eversmokers in 1984, but not in 2001. 'Unmarried' was significantly associated in 2001 but not in 1984. 'Alcohol dependence' was the only psychiatric disorder associated with 12-month TD in both study years. In conclusion, 12-month TD was found in about 50% of ever-smokers, and gender differences between the rates of 12-month TD which was observed in 1984 disappeared in 2001. Individuals with 12-month TD showed higher comorbidity with alcohol dependence than ever-smokers without TD.