Assessment of the viability of integrating virtual reality programs in practical tests for the Korean Radiological Technologists Licensing Examination: a survey study

PURPOSE

The objective of this study was to assess the feasibility of incorporating virtual reality/augmented reality (VR/AR) programs into practical tests administered as part of the Korean Radiological Technologists Licensing Examination (KRTLE). This evaluation is grounded in a comprehensive survey that targeted enrolled students in departments of radiology across the nation.

METHODS

In total, 682 students from radiology departments across the nation were participants in the survey. An online survey platform was used, and the questionnaire was structured into 5 distinct sections and 27 questions. A frequency analysis for each section of the survey was conducted using IBM SPSS ver. 27.0.

RESULTS

Direct or indirect exposure to VR/AR content was reported by 67.7% of all respondents. Furthermore, 55.4% of the respondents expressed that VR/AR could be integrated into their classes, which signified a widespread acknowledgment of VR among the students. With regards to the integration of a VR/AR or mixed reality program into the practical tests for purposes of the KRTLE, a substantial amount of the respondents (57.3%) exhibited a positive inclination and recommended its introduction.

CONCLUSION

The application of VR/AR programs within practical tests of the KRTLE will be used as an alternative for evaluating clinical examination procedures and validating job skills.

AMPK boosts ADAM10 shedding activity in human aortic endothelial cells by promoting Rab14-dependent ADAM10 cell surface translocation

A disintegrin and metalloprotease 10 (ADAM10) regulates the expression of cell surface receptors such as tumor necrosis factor receptor 1, toll-like receptor 4, and the receptor for advanced glycation end products (RAGE) by cleaving their extracellular regions. To function as a sheddase, ADAM10 should translocate from the intracellular compartments to the cell surface, but the translocation mechanism remains unclear. In this study, we explored the possible role of adenosine monophosphate-activated protein kinase (AMPK) in the induction of ADAM10 shedding activity. In cultured human aortic endothelial cells (HAECs), 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), an AMPK activator, boosted ADAM10 cell surface translocation and ectodomain shedding of RAGE. ADAM10 inhibition with GI 254023X and ADAM10 siRNA silencing both prevented AICAR-induced RAGE ectodomain shedding. AICAR increased AMPK phosphorylation as well. Both Compound C-mediated AMPK inhibition and AMPKα1-siRNA-mediated AMPK depletion suppressed AICAR-induced ADAM10 cell surface translocation and RAGE ectodomain shedding. On the other hand, siRNA knockdown of Rab14, a small GTPase that facilitates the intracellular trafficking of transmembrane proteins, prevented AICAR-induced ADAM10 cell surface translocation and RAGE ectodomain shedding. In conclusion, AMPK activation is an obvious inducer of ADAM10 shedding activity. Our findings suggest that AMPK boosts ADAM10 shedding activity in HAECs by promoting Rab14-dependent ADAM10 cell surface translocation.

Risk of bleeding-related complications after kidney biopsy in patients with systemic lupus erythematosus

OBJECTIVE

Kidney biopsy is essential for the diagnosis and classification of lupus nephritis. Percutaneous biopsy has a risk of bleeding-related complications; however, data on the risk of percutaneous kidney biopsy in patients with systemic lupus erythematosus (SLE) are scarce. In this study, we aimed to investigate the rate of bleeding-related complications and to examine the risk factors for complications of kidney biopsy in patients with systemic lupus erythematosus (SLE).  METHODS: We retrospectively reviewed the medical records of patients with SLE who underwent ultrasound-guided percutaneous kidney biopsy between 2002 and 2020 at a tertiary referral center. Minor complications were defined as hematoma and passing hematuria not requiring an intervention. Major complications included bleeding events that required interventions after the biopsy. Statistical analysis with a multivariate logistic regression model was performed.

RESULTS

In a total of 277 patients with SLE, the rate of overall bleeding-related complications after kidney biopsy was 19.9% (minor 13.0%; major 6.9%). Among patients with major complications, 84.2% needed blood transfusion alone without embolization or surgery, whereas the remaining three patients needed embolization for bleeding control. Multivariate analysis revealed that thrombocytopenia (odds ratio [OR] 7.186, 95% confidence interval [CI] 2.315-22.300), and low eGFR (OR 3.478, 95% CI 1.094-11.056) were significantly associated with the risk of major bleeding-related complications after kidney biopsy.

CONCLUSION

Percutaneous kidney biopsy is accompanied by the risk of bleeding-related complications; however, most events in our study did not require vascular intervention for bleeding control. Low platelet count and low estimated glomerular filtration rate (eGFR) significantly increase the risk of complications after kidney biopsy in patients with SLE. Key Points • The rate of overall bleeding-related complications after kidney biopsy was about 20% of patients with SLE. • The most commonly observed events were gross hematuria followed by blood transfusion. • Thrombocytopenia and poor kidney function areis an important risk of bleeding-related complications after kidney biopsy.

RSK1 and RSK2 serine/threonine kinases regulate different transcription programs in cancer

The 90 kDa ribosomal S6 kinases (RSKs) are serine threonine kinases comprising four isoforms. The isoforms can have overlapping functions in regulation of migration, invasion, proliferation, survival, and transcription in various cancer types. However, isoform specific differences in RSK1 versus RSK2 functions in gene regulation are not yet defined. Here, we delineate ribosomal S6 kinases isoform-specific transcriptional gene regulation by comparing transcription programs in RSK1 and RSK2 knockout cells using microarray analysis. Microarray analysis revealed significantly different mRNA expression patterns between RSK1 knockout and RSK2 knockout cell lines. Importantly some of these functions have not been previously recognized. Our analysis revealed RSK1 has specific roles in cell adhesion, cell cycle regulation and DNA replication and repair pathways, while RSK2 has specific roles in the immune response and interferon signaling pathways. We further validated that the identified gene sets significantly correlated with mRNA datasets from cancer patients. We examined the functional significance of the identified transcriptional programs using cell assays. In alignment with the microarray analysis, we found that RSK1 modulates the mRNA and protein expression of Fibronectin1, affecting cell adhesion and CDK2, affecting S-phase arrest in the cell cycle, and impairing DNA replication and repair. Under similar conditions, RSK2 showed increased ISG15 transcriptional expression, affecting the immune response pathway and cytokine expression. Collectively, our findings revealed the occurrence of RSK1 and RSK2 specific transcriptional regulation, defining separate functions of these closely related isoforms.

Design of Bronze-Rich Dual-Phasic TiO2 Embedded Amorphous Carbon Nanocomposites Derived from Ti-Metal-Organic Frameworks for Improved Lithium-Ion Storage

Dual-phasic (DP)-TiO₂ -based composites are considered attractive anode materials for high lithium-ion storage because of the synergetic contribution from dual-phases in lithium-ion storage. However, a comprehensive investigation on more efficient architectures and platforms is necessary to develop lithium-storage devices with high-rate capability and long-term stability. Herein, for the first time, a rationally designed bronze-rich DP-TiO₂ -embedded amorphous carbon nanoarchitecture, denoted as DP-TiO₂ @C, from sacrificial Ti-metal-organic frameworks (Ti-MOFs) via a two-step pyrolysis process is proposed. The bronze/anatase DP-TiO₂ @C nanocomposites are successfully synthesized using a unique pyrolysis process, which decomposes individually the metal clusters and organic linkers of Ti-MOFs. DP-TiO₂ @C exhibits a significantly high density and even distribution of nanoparticles (<5 nm), enabling the formation of numerous heterointerfaces. Remarkably, the bronze-rich DP-TiO₂ @C shows high specific capacities of 638 and 194 mAh g^-1 at current densities of 0.1 and 5 A g^-1 , respectively, owing to the contribution of the synergetic interfacial structure. In addition, reversible specific capacities are observed at a high rate (5 A g^-1 ) during 6000 cycles. Thus, this study presents a new approach for the synthesis of DP-TiO₂ @C nanocomposites from a sacrificial Ti-MOF and provides insights into the efficient control of the volume ratio in DP-TiO₂ anode architecture.

Liraglutide, a glucagon-like peptide-1 receptor agonist, induces ADAM10-dependent ectodomain shedding of RAGE via AMPK activation in human aortic endothelial cells

AIMS

Glucagon-like peptide-1 alleviates the deleterious effects of advanced glycation end products (AGEs), but the underlying mechanisms are not fully understood. In this study, we investigated the protective mechanism using liraglutide, a glucagon-like peptide-1 receptor agonist, in cultured human aortic endothelial cells (HAECs).

MAIN METHODS

Following liraglutide treatment in HAECs, the receptor for AGEs (RAGE) was measured in both cell lysate and culture supernatant, the cytosolic free Ca²⁺ level was monitored using Fluo-4 AM, the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) was analyzed, and immunofluorescence staining was used to visualize a disintegrin and metalloprotease 10 (ADAM10) on the cell surface.

KEY FINDINGS

Liraglutide (100 nM) induced ectodomain shedding of RAGE within 30 min and inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) induced by AGEs of bovine serum albumin (AGE-BSA). Further experiments revealed that liraglutide rapidly increased extracellular Ca²⁺ influx through L-type calcium channels and activated AMPK, resulting in translocation of ADAM10 to the cell surface, whereas siRNA-mediated ADAM10 depletion prevented liraglutide-induced ectodomain shedding of RAGE and eliminated liraglutide's inhibitory effect on AGE-BSA-induced ICAM-1 expression. Moreover, compound C-mediated AMPK inhibition and siRNA-mediated AMPK depletion both prevented ADAM10 translocation to the cell surface and ADAM10-mediated ectodomain shedding of RAGE.

SIGNIFICANCE

Liraglutide reduces the number of intact RAGE on the cell surface by inducing ADAM10-mediated ectodomain shedding, which decreases the inflammatory effects of AGEs. AMPK activated by extracellular Ca²⁺ influx is critically involved in the translocation of ADAM10 to the cell surface, where it cleaves RAGE.

Validation and modification of HEART score components for patients with chest pain in the emergency department

OBJECTIVE

This study aimed to clarify the relative prognostic value of each History, Electrocardiography, Age, Risk Factors, and Troponin (HEART) score component for major adverse cardiac events (MACE) within 3 months and validate the modified HEART (mHEART) score.

METHODS

This study evaluated the HEART score components for patients with chest symptoms visiting the emergency department from November 19, 2018 to November 19, 2019. All components were evaluated using logistic regression analysis and the scores for HEART, mHEART, and Thrombolysis in Myocardial Infarction (TIMI) were determined using the receiver operating characteristics curve.

RESULTS

The patients were divided into a derivation (809 patients) and a validation group (298 patients). In multivariate analysis, age did not show statistical significance in the detection of MACE within 3 months and the mHEART score was calculated after omitting the age component. The areas under the receiver operating characteristics curves for HEART, mHEART and TIMI scores in the prediction of MACE within 3 months were 0.88, 0.91, and 0.83, respectively, in the derivation group; and 0.88, 0.91, and 0.81, respectively, in the validation group. When the cutoff value for each scoring system was determined for the maintenance of a negative predictive value for a MACE rate >99%, the mHEART score showed the highest sensitivity, specificity, positive predictive value, and negative predictive value (97.4%, 54.2%, 23.7%, and 99.3%, respectively).

CONCLUSION

Our study showed that the mHEART score better detects short-term MACE in high-risk patients and ensures the safe disposition of low-risk patients than the HEART and TIMI scores.

Automated urine sediment analyzers underestimate the severity of hematuria in glomerular diseases

Hematuria, either glomerular or extraglomerular, is defined as 3 or more red blood cells (RBCs)/high power field. Currently, urinalyses are commonly performed using automated urine sediment analyzers. To assess whether RBC counting by automated urine sediment analyzers is reliable for defining hematuria in glomerular disease, random specimen urinalyses of men with nephritic glomerular disease (7674 urinalyses) and bladder cancer (12,510 urinalyses) were retrospectively reviewed. Urine RBCs were counted by an automated urine sediment analyzer based on flow cytometry (UF-1000i, Sysmex Corporation) or digital image analysis (Cobas 6500, Roche Diagnostics GmbH). In about 20% of urine specimens, the specific gravity was less than 1.010, making the RBC counts unreliable. In the urine specimens with specific gravity ≥ 1.010, RBC counts measured using either UF-1000i or Cobas 6500 were well correlated with the positive grades in the dipstick blood test. However, at a trace, 1+, or higher positive dipstick tests for blood, RBC counts were graded significantly lower in glomerular disease than in bladder cancer. The findings suggest that RBC counting by UF-1000i or Cobas 6500 underestimates the severity of hematuria in glomerular disease, possibly because dysmorphic RBCs in glomerular disease are susceptible to hemolysis and/or fail to be properly recognized.

Non-diabetic glycosuria as a diagnostic clue for acute tubulointerstitial nephritis in patients with azotemia

Background

Glycosuria is one of the manifestations of acute tubulointerstitial nephritis (ATIN), but may also be observed in other renal diseases. In this study, we investigated the value of non-diabetic glycosuria as a diagnostic clue for ATIN.

Methods

We retrospectively reviewed the medical records of adult patients who underwent a kidney biopsy as an evaluation for serum creatinine > 1.4 mg/dL. Patients with proteinuria in the nephrotic range, diabetes mellitus, or transplanted kidney were excluded. The laboratory abnormalities suggestive of tubular injury were compared between 28 patients (14 men and 14 women, mean age 48.5 ± 14.1 years) with ATIN and 116 patients (76 men and 40 women, mean age 53.1 ± 15.0 years) with other diagnoses.

Results

In ATIN, glycosuria (≥ 1+ on dipstick; 68%) was more frequent than hypophosphatemia (18%), hypouricemia (18%), hypokalemia (18%), and tubular proteinuria (40%). In other diagnoses, glycosuria (≥ 1+) was detected in 7 (6%) patients; 6 of them had the histological diagnosis of antineutrophil cytoplasmic antibody-associated glomerulonephritis. The presence of glycosuria (≥ 1+) had 68% sensitivity and 94% specificity for ATIN, with the positive likelihood ratio of 11.24 and the negative likelihood ratio of 0.34. Pyuria and low total CO₂ were equally and more sensitive (68% and 71%, respectively) than glycosuria (≥ 1+), but had no diagnostic value due to low specificities (58% and 60%, respectively).

Conclusion

In non-diabetic, non-nephrotic patients undergoing a kidney biopsy for azotemia, 1+ or higher glycosuria, if present, was a good predictor of the diagnosis of ATIN.

Application of convolutional neural networks for distal radio-ulnar fracture detection on plain radiographs in the emergency room

OBJECTIVE

Recent studies have suggested that deep-learning models can satisfactorily assist in fracture diagnosis. We aimed to evaluate the performance of two of such models in wrist fracture detection.

METHODS

We collected image data of patients who visited with wrist trauma at the emergency department. A dataset extracted from January 2018 to May 2020 was split into training (90%) and test (10%) datasets, and two types of convolutional neural networks (i.e., DenseNet-161 and ResNet-152) were trained to detect wrist fractures. Gradient-weighted class activation mapping was used to highlight the regions of radiograph scans that contributed to the decision of the model. Performance of the convolutional neural network models was evaluated using the area under the receiver operating characteristic curve.

RESULTS

For model training, we used 4,551 radiographs from 798 patients and 4,443 radiographs from 1,481 patients with and without fractures, respectively. The remaining 10% (300 radiographs from 100 patients with fractures and 690 radiographs from 230 patients without fractures) was used as a test dataset. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of DenseNet-161 and ResNet-152 in the test dataset were 90.3%, 90.3%, 80.3%, 95.6%, and 90.3% and 88.6%, 88.4%, 76.9%, 94.7%, and 88.5%, respectively. The area under the receiver operating characteristic curves of DenseNet-161 and ResNet-152 for wrist fracture detection were 0.962 and 0.947, respectively.

CONCLUSION

We demonstrated that DenseNet-161 and ResNet-152 models could help detect wrist fractures in the emergency room with satisfactory performance.

Gold(I) Complexes with a Quinazoline Carboxamide Alkynyl Ligand: Synthesis, Cytotoxicity, and Mechanistic Studies

A series of gold(I) complexes with the general formula [Au(L2)(L')] (L2=4-phenyl-N-(prop-2-yn-1-yl)quinazoline-2-carboxamide, L'=PPh3 (triphenylphosphine), 1; TPA (1,3,5-triaza-7-phosphaadamantane), 2, and Me2-imy (1,3-dimethylimidazol-2-ylidene), 3) were synthesized and fully characterized by spectroscopic methods. The alkynyl ligand L2 belongs to the quinazoline carboxamide class of ligands that are known to bind to the translocator protein (TSPO) at the outer mitochondrial membrane. 1 and 2 exert cytotoxic effects in bladder cancer cells with IC50 values in the low micromolar range. Further mechanistic analysis indicated that the two complexes both act by inducing reactive oxygen species and caspase-mediated apoptosis. The complexes inhibit thioredoxin reductase, an established target of anticancer gold(I) complexes. Docking studies confirmed that after ligand exchange the free ligand L2 can interact with the TSPO binding site.

Investigation of the Inhibitory Effect of Platycodin D in Human Transitional Cell Carcinoma Cell Line 5637

Platycodin D is an active component isolated from Chinese herb Platycodonis radix with various pharmacological activities, such as antitussive, expectorant, anti-inflammatory, and analgesic effects. Interestingly, platycodin D also exerts anticancer effects against several types of cancer. However, few studies on the anti-tumour effects of platycodin against urinary bladder cancer have been reported. In this study, we explored the anti-tumour effect of platycodin D against human bladder cancer and its mechanisms in vitro and in vivo. We found that platycodin D had significant anti-proliferative effects on four types of cancer cells, especially the 5637 bladder cancer cell line, and exerted these effects by preventing cell cycle progression from G0/G1 to S phase, down-regulating Ki-67 and cyclin D1 protein expression and up-regulating P21 protein expression. Furthermore, platycodin D inhibited 5637 cell migration by decreasing twist-related protein 1 (Twist1) and matrix metallopeptidase 2 (MMP2) expression and exerted significant tumour-suppressive effects in tumour-bearing nude mice. Platycodin D also increased caspase-9, caspase-8, caspase-3, and p53 expression and decreased Bcl-2 expression in tumour tissues. Taken together, our results provide a theoretical basis for application of platycodin D in treating urinary bladder cancer.

RasGRP1 induces autophagy and transformation-associated changes in primary human keratinocytes

Ras mutations are present in only a subset of sporadic human cutaneous squamous cell carcinomas (cSCC) even though Ras is activated in most. This suggests that other mechanisms of Ras activation play a role in the disease. The aberrant expression of RasGRP1, a guanyl nucleotide exchange factor for Ras, is critical for mouse cSCC development through its ability to increase Ras activity. However, the role of RasGRP1 in human keratinocyte carcinogenesis remains unknown. Here we report that RasGRP1 is significantly elevated in human cSCC and that high RasGRP1 expression in human primary keratinocytes triggered activation of endogenous Ras and significant morphological changes including cytoplasmic vacuole formation and growth arrest. Moreover, RasGRP1-expressing cells were autophagic as indicated by LC3-II increase and the formation of LC3 punctae. In an in vitro organotypic skin model, wild type keratinocytes generated a well-stratified epithelium, while RasGRP1-expressing cells failed to do so. Finally, RasGRP1 induced transformation-like changes in skin cells from Li-Fraumeni patients with inactivating p53 mutations, demonstrating the oncogenic potential of this protein. These results support a role for RasGRP1 in human epidermal keratinocyte carcinogenesis and might serve as an important new therapeutic target.

Auranofin-Based Analogues Are Effective Against Clear Cell Renal Carcinoma In Vivo and Display No Significant Systemic Toxicity

Effective pharmacological treatments for patients with advanced clear cell renal carcinoma (ccRCC) are limited. Bimetallic titanium-gold containing compounds exhibit significant cytotoxicity against ccRCC in vitro and in vivo and inhibit invasion and angiogenisis in vitro and markers driving these phenomena. However, in vivo preclinical evaluations of such compounds have not examined their pharmacokinetics, pathology, and hematology. Here we use NOD.CB17-Prkdc SCID/J mice bearing xenograft ccRCC Caki-1 tumors to evaluate the in vivo efficacies of two titanium-gold compounds Titanocref and Titanofin (based on auranofin analogue scaffolds) accompanied by pharmacokinetic and pathology studies. A therapeutic trial was performed over 21 days at 5 mg/kg/72h of Titanocref and 10 mg/kg/72h of Titanofin tracking changes in tumor size. We observed a significant reduction of 51% and 60%, respectively (p < 0.01) in tumor size in the Titanocref- and Titanofin-treated mice compared to the starting size, while the vehicle-treated mice exhibited a tumor size increase of 138% (p < 0.01). Importantly, no signs of pathological complication as a result of treatment were found. In addition, Titanocref and Titanofin treatment reduced angiogenesis by 38% and 54%, respectively. Microarray and qRT-PCR analysis of ccRCC Caki-1 cells treated with Titanocref revealed that the compound alters apoptosis, JNK MAP kinase, and ROS pathways within 3 h of treatment. We further show activation of apoptosis by Titanocref and Titanofin in vivo by caspase 3 assay. Titanocref is active against additional kidney cancer cells. Titanocref and Titanofin are therefore promising candidates for further evaluation toward clinical application in the treatment of ccRCC.

Auranofin-Based Analogues Are Effective Against Clear Cell Renal Carcinoma In Vivo and Display No Significant Systemic Toxicity

Effective pharmacological treatments for patients with advanced clear cell renal carcinoma (ccRCC) are limited. Bimetallic titanium-gold containing compounds exhibit significant cytotoxicity against ccRCC in vitro and in vivo and inhibit invasion and angiogenisis in vitro and markers driving these phenomena. However, in vivo preclinical evaluations of such compounds have not examined their pharmacokinetics, pathology, and hematology. Here we use NOD.CB17-Prkdc SCID/J mice bearing xenograft ccRCC Caki-1 tumors to evaluate the in vivo efficacies of two titanium-gold compounds Titanocref and Titanofin (based on auranofin analogue scaffolds) accompanied by pharmacokinetic and pathology studies. A therapeutic trial was performed over 21 days at 5 mg/kg/72h of Titanocref and 10 mg/kg/72h of Titanofin tracking changes in tumor size. We observed a significant reduction of 51% and 60%, respectively (p < 0.01) in tumor size in the Titanocref- and Titanofin-treated mice compared to the starting size, while the vehicle-treated mice exhibited a tumor size increase of 138% (p < 0.01). Importantly, no signs of pathological complication as a result of treatment were found. In addition, Titanocref and Titanofin treatment reduced angiogenesis by 38% and 54%, respectively. Microarray and qRT-PCR analysis of ccRCC Caki-1 cells treated with Titanocref revealed that the compound alters apoptosis, JNK MAP kinase, and ROS pathways within 3 h of treatment. We further show activation of apoptosis by Titanocref and Titanofin in vivo by caspase 3 assay. Titanocref is active against additional kidney cancer cells. Titanocref and Titanofin are therefore promising candidates for further evaluation toward clinical application in the treatment of ccRCC.

Collagenofibrotic glomerulopathy- report of a rare renal disease with serial biopsies

INTRODUCTION

Collagenofibrotic glomerulopathy or collagen type-III glomerulopathy is a rare glomerular disease characterised by the deposition of type III collagen fibres in the subendothelial space and mesangium of the glomerulus.

CASE REPORT

Here, we present a case of collagenofibrotic glomerulopathy in a 49-year-old Indian female, the first to be reported from Singapore. Renal biopsy showed PAS (periodic acid-Schiff), silver and Congo red negative, amorphous extracellular material that expanded mesangial and subendothelial regions. Such materials were strongly positive for anti-collagen III immunofluorescent staining. Under electron microscopy, the mesangial and some subendothelial regions were greatly expanded by abundant collagen fibres which were different from normal collagen III fibres in both appearance and periodicity.

DISCUSSION

The availability of past renal biopsies for reference offered insight into disease progression. From the initial diagnosis of focal segmental glomerulosclerosis to eventually collagenofibrotic glomerulopathy over a time span of more than 10 years, this case highlights the gradual accumulation of collagen fibres in the glomeruli before classical features are apparent. It also emphasises the importance of electron microscopy in the diagnosis of this disease.

Validation of the Good Outcome Following Attempted Resuscitation (GO-FAR) score in an East Asian population

AIM

The Good Outcome Following Attempted Resuscitation (GO-FAR) score is useful for identifying patients post-arrest with very poor neurologic outcomes and may thus be utilized when counseling family members on do-not-attempt-resuscitation (DNAR) order. We validated the GO-FAR score for neurologically intact survival in patients with in-hospital cardiac arrest (IHCA) in an East Asian country in which DNAR order not common.

METHODS

Retrospective study about patients who experienced IHCA from 2013 to 2017 with a primary outcome of neurologically intact survival, defined as a CPC score 1 or 2 at discharge. GO-FAR score categorizes the patients into 4 groups: a very low (<1%), low (1%-3%), average (>3%-15%), or higher than average (>15%) likelihood of neurologically intact survival.

RESULTS

Of the 1011 included patients, the rates of survival discharge and neurologically intact survival at discharge were 25.4% and 16.0%, respectively. The area under the receiver operating characteristics curve of GO-FAR score for good neurological outcome was 0.81 (95% CI, 0.78-0.84). Patients with low or very low probability of survival had a likelihood of 0.9% (95% CI, 0.0-2.0), but for those under 40 years old, it was increased to 4.2% (95% CI, 0.0-12.2). Patients with average or above-average probabilities had likelihoods of of 18.5% (95% CI, 15.3-21.6) and 50.5% (95% CI, 40.6-60.5), respectively.

CONCLUSIONS

The GO-FAR score well-predicted the neurologically intact survival of East Asian patients with IHCA. This tool may be used as part of a shared decision regarding DNAR orders.

An electromagnetic separation system for the enrichment of 39Ar

An isotope enrichment system for ³⁹Ar has been developed at the Institute of Modern Physics, which is designed to increase the abundance of ³⁹Ar in the incident sample gas. With intense Ar⁺ beams produced by a 2.45 GHz electron cyclotron resonance ion source and a high mass resolution spectrometer system, Ar isotopes are evidently separated on the target plane and selectively collected by an Al target. The separated Ar isotopes have been identified on the target plane, which is consistent with the simulations. According to the recent cross-checked results with atom trap trace analysis, a high enrichment factor of ³⁹Ar has been successfully achieved. This paper will present the design and test results of this system.

Role of Hypoalbuminemia in the Genesis of Cardiovascular Disease in Dialysis Patients

Our objective was to review the articles about the association between hypoalbuminemia and atherosclerotic or thrombotic cardiovascular disease (CVD) and to look for possible explanations for the role of hypoalbuminemia.

Increased incidences of CVD were reported in patients with hypoalbuminemia owing to renal or other diseases. Hypoalbuminemia increases plasma levels of lipoprotein(a), fibrinogen, and arachidonic acid metabolites; it also increases platelet aggregability and blood viscosity, all of which may contribute to the development of CVD. This cause-effect association is thought to be “dependent.” Changes in atherogenic lipoproteins or lipids, such as LDL cholesterol, triglycerides, and apolipoprotein B, are controversial in hypoalbuminemic dialysis patients, possibly because coexistent malnutrition and volume status can affect both albumin and lipids. In our recent study, there was a negative correlation between serum albumin and C-reactive protein, D-dimer (an index of intravascular thrombogenesis), and von Willebrand factor (a marker for endothelial cell injury), but infusion of albumin did not affect the level of these parameters, which suggests that the correlations may be an effect-effect association by a confounding variable, such as inflammation.

In conclusion, hypoalbuminemia is associated with cardiovascular disease via two pathways: one, a “dependent” cause-effect association; the other, an effect-effect association.

Reviews and Original Articles Lipoprotein(A) and Apolipoprotein(A) Phenotypes in Patients with End-Stage Renal Disease

Objective

To evaluate the distribution pattern of apolipoprotein(a) [Apo(a)] phenotypes in Koreans and the effect of dialysis modality on serum lipoprotein(a) [Lp(a)] concentration according to apo(a) phenotype in patients with end-stage renal disease (ESRO).

Design

Cross-sectional study.

Setting

A university hospital. Participants: 153 normal controls, 99 hemodialysis (HO) patients and 82 continuous ambulatory peritoneal dialysis (CAPO) patients.

Main Outcome Measures

Fasting serum Lp(a), lipids, and apo(a) phenotypes were measured.

Results

The frequencies of the subjects with apo(a) phenotypes of high-molecular weight only, including S3, S4, or S5 or null type were 95.4% of control, 100% of HO patients, and 95.1% of CAPO patients. The frequent apo(a) phenotypes in Koreans consisted of S4, S4S5, S5, and S5S5 isoforms. Significant difference was found in serum Lp(a) concentration among controls and HO and CAPO patients [median (interquartile range): 0.05 g/L, (0.01 0.19); 0.19g/L, (0.10 0.35); 0.63g/L, (0.28 0.90), p< 0.001]. Lp(a) levels in CAPO patients were significantly higher than in HO patients for all four common apo(a) isoforms found in Korean subjects. CAPO patients had higher total and LOL cholesterol levels, and higher ApoB levels than H O patients. Significant differences were found in serum albumin levels between controls and HO and CAPO patients (44 ± 3 g/L, 40 ± 4 g/L, 32 ± 7 g/L, respectively, p < 0.05). There were significant inverse correlations between serum albumin and Lp(a) (r = -0.33, p < 0.01), total cholesterol (r = -0.31, p < 0.01), LOL (r = -0.39, p < 0.01) or ApoB (r = -0.35, p < 0.01) in ESRO patients. A significant positive correlation was found between serum albumin and ApoA1 (r = 0.24, p < 0.01).

Conclusion

These findings indicate that Koreans have mainly high -molecular weight apo(a) phenotypes and serum Lp(a) is elevated in CAPO patients compared to HO patients for common apo(a) phenotypes, which may contribute to the frequent cardiovascular mortality in CAPO patients.

Interleukin-1β Stimulates the Production of Extracellular Matrix in Cultured Human Peritoneal Mesothelial Cells

Objective

To investigate the effect of interleukin-1β (IL-1β) on the production of extracellular matrix in cultured human peritoneal mesothelial cells (HPMCs).

Design

Cultured HPMCs were treated with or without IL-1β. Cell morphology was observed. The expression of fibronectin, α1(I) procollagen, and transforming growth factor-β1 (TGFβ1) mRNAs was measured by Northern blot analysis. The cell surface expression of fibronectin and type I collagen was evaluated by immunofluorescent staining. Fibronectin and type I collagen in culture supernatant were measured by inhibition ELISA.

Results

Interleukin-1β induced morphologic change in HPMCs from a cuboidal epithelioid shape into an elongated fibroblastoid shape. The elongated cells were positive for cytokeratin although they had a fibroblastoid appearance. Treatment of HPMCs with IL-1β resulted in increased expression of both fibronectin and α1(I) procollagen mRNA in dose- and time-dependent manners. Immunofluorescent staining showed strong and diffuse cytoplasmic expression of fibronectin and type I collagen in the cells treated with IL-1β, whereas only weak perinuclear cytoplasmic staining was noted in the cells on media alone. The concentrations of secreted fibronectin and type I collagen in culture supernatant were significantly higher in the cells treated with IL-1β than in the control cells. IL-1β also stimulated the expression of TGFβ1 mRNA. However, IL-1β-induced fibronectin mRNA expression was only partially blocked by neutralizing anti-TGFβ antibody.

Conclusion

Interleukin-1β stimulated the production of extracellular matrix in cultured HPMCs along with the induction of morphologic changes. This may play a role in the development of peritoneal fibrosis caused by peritonitis or bioincompatible dialysate in continuous ambulatory peritoneal dialysis patients.

Reduced Oxidative Stress in Hypoalbuminemic CAPD Patients

Objective

Albumin is one of the plasma antioxidants. The higher incidence of cardiovascular disease in dialysis patients with hypoalbuminemia may be related to decreased antioxidant capacity resulting from low serum albumin. We evaluated malondialdehyde (MDA), a marker of oxidative stress, and total antioxidant capacity (TAC) in relation to serum albumin in continuous ambulatory peritoneal dialysis (CAPD) patients.

Patients and Methods

In this cross-sectional study, we measured MDA, TAC, albumin, uric acid (another important plasma antioxidant), prealbumin, and C-reactive protein (CRP) in the blood of 66 CAPD patients and 30 normal controls. Twenty-two CAPD patients with albumin less than or equal to 3.5 g/dL were divided into two groups: In the experimental group ( n = 11), MDA, TAC, and CRP were measured before and after repeated infusion of 20% albumin 100 mL daily for 7 days. In the control group ( n = 11), the same parameters were measured without albumin infusion.

Results

CAPD patients had lower albumin and higher MDA, TAC, and uric acid than normal controls. There were positive correlations between albumin and TAC or uric acid in CAPD patients. Contrary to our expectation, there was also positive correlation between albumin and MDA in CAPD patients ( r = 0.37, p = 0.004). MDA showed a positive correlation with TAC. Uric acid was correlated with TAC. It did not, however, show correlation with MDA. Log CRP was negatively correlated with albumin, but did not show correlation with MDA or TAC. Prealbumin was correlated with MDA, TAC, albumin, and uric acid. Serum albumin in the experimental group increased from 2.5 ± 0.3 g/dL to 3.6 ± 0.2 g/dL ( p < 0.001) at the end of repeated infusions. No changes were seen in MDA, TAC, and CRP in either group.

Conclusions

The present study suggests that lipid peroxidation is increased in CAPD patients and that this is not due to weakening of antioxidant defenses of plasma. Increased TAC was mainly caused by a higher level of uric acid. Reduced, rather than increased, MDA in hypoalbuminemic patients and lack of effects of albumin infusion on levels of MDA suggest that the frequent occurrence of cardiovascular disease in dialysis patients with hypoalbuminemia is not due to the decrease in antioxidant capacity resulting from low serum albumin.

Epigallocatechin-3-gallate downregulates lipopolysaccharide signaling in human aortic endothelial cells by inducing ectodomain shedding of TLR4

Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea leaves, has anti-inflammatory effects. In this study, we investigated the mechanism by which EGCG attenuates the effects of lipopolysaccharide (LPS), an agonist of toll-like receptor 4 (TLR4), in cultured human aortic endothelial cells (HAECs). The increase in the expression of intercellular adhesion molecule-1 (ICAM-1) induced by LPS (100 ng/ml) was effectively attenuated by pretreatment with EGCG (50 μM). Importantly, EGCG treatment resulted in a rapid reduction of cellular TLR4, which was accompanied by an increase in the N-terminal fragment of TLR4 in the culture supernatant, indicating that EGCG induces ectodomain shedding of TLR4. EGCG increased cytosolic Ca²⁺ by inducing the release of intracellular stored Ca²⁺ and the influx of extracellular Ca²⁺; accordingly, EGCG-induced ectodomain shedding of TLR4 was nullified by pretreatment with BAPTA-AM (10 μM), an intracellular Ca²⁺ chelator. EGCG induced translocation of a disintegrin and metalloprotease 10 (ADAM10) to the cell surface, which was also blocked by BAPTA-AM. Treatment with ADAM10 inhibitor (GI254023X, 2 μM) and siRNA-mediated depletion of ADAM10 prevented EGCG-induced ectodomain shedding of TLR4 and abolished the inhibitory effect of EGCG on LPS-induced ICAM-1 expression. Collectively, these findings suggest that EGCG decreases cell surface TLR4 in HAECs by inducing ADAM10-mediated ectodomain shedding, and thereby attenuates the effects of LPS. This is a new mechanism of the suppressive effect of EGCG on LPS signaling.

Febuxostat, a novel inhibitor of xanthine oxidase, reduces ER stress through upregulation of SIRT1-AMPK-HO-1/thioredoxin expression

BACKGROUND

Endoplasmic reticulum (ER) stress has been implicated in the development of various renal diseases. Thus, inhibition of ER stress using pharmacological agents may serve as a promising therapeutic approach. We postulated that febuxostat, a novel xanthine oxidase inhibitor, could suppress the ER stress through upregulation of SIRT1 (silent mating type information regulation 2 homolog 1)-AMPK (AMP activated protein kinase)-HO-1 (heme oxygenase-1)/thioredoxin expression.

METHODS

We examined the effect of febuxostat on the ER stress induced by a chemical inducer, tunicamycin and non-chemical agents such as angiotensin II, aldosterone, high glucose, and albumin in renal tubular cells. We further examined the in vivo effects of febuxostat using mouse model of kidney disease induced by unilateral ureteral obstruction (UUO). Expression of ER stress was measured by western blot analysis and immunohistochemical stain.

RESULTS

Febuxostat suppressed the ER stress induced by tunicamycin and non-chemical agents, as shown by inhibition of increased GRP78 (glucose-related protein78) and p-eIF2α (phosphospecific-eukaryotic translation initiation factor 2α) expression. Inhibitory effect of febuxostat was mediated through upregulation of SIRT1-AMPK followed by induction of HO-1 and thioredoxin. In animal model of UUO, febuxostat reduced the UUO-induced ER stress, which was abolished by pretreatment with SIRT1 inhibitor (sirtinol) and AMPK inhibitor (compound C).

CONCLUSION

Febuxostat could suppress the ER stress caused by various ER stress inducers through upregulation of SIRT1-AMPK-HO-1/thioredoxin expression. Targeting these pathways might serve as one of the possible therapeutic approaches in kidney diseases under excessive ER stress.

Usefulness of mid-week hemoglobin measurement for anemia management in patients undergoing hemodialysis: a retrospective cohort study

Background

Short-term hemoglobin (Hb) variability related to volume status is observed in chronic kidney disease (CKD) patients receiving hemodialysis (HD). Given the lack of studies regarding outcomes according to the day of Hb sampling, the existing guidelines do not strongly recommend regarding measurement timing. Pre-dialysis mid-week sampling (Wednesday and Thursday) is preferable to minimize short-term Hb variability, although numerous HD centers perform early-week sampling (Monday and Tuesday). The different measurement days may influence the prescribed dose of erythropoiesis-stimulating agent (ESA) and related patient outcomes. We investigated changes in Hb levels and ESA doses according to the Hb measurement day among HD patients.

Methods

Starting September 2013, the day for pre-dialysis Hb measurement at the Asan Medical Center was changed from early-week days to mid-week days. This single-center retrospective study evaluated medical records of 92 patients who received maintenance HD between September 2012 and August 2014.

Results

There was no significant difference in the mean Hb levels between early-week days and mid-week days (10.71 ± 0.06 g/dL vs. 10.78 ± 0.47 g/dL, p = 0.105). However, the mean doses of darbepoetin-α on early-week days were higher than those on mid-week days (175.4 ± 72.5 μg/month vs. 163.7 ± 83.6 μg/month, p = 0.022). The mean doses of intravenous iron hydroxide sucrose for early-week measurements were also higher than those for mid-week measurements (623.0 ± 489.0 mg/year vs. 447.0 ± 505.2 mg/year, p = 0.001). The mean interdialytic weight gains were 2.81 ± 0.82 kg on early-week days and 1.99 ± 0.61 kg on mid-week days (p < 0.001).

Conclusions

Compared with early-week measurements, mid-week pre-dialysis Hb measurements were significantly associated with lower ESA doses without a change in Hb levels.

Expression pattern of estrogen receptor β and its correlation with multidrug resistance in non-small cell lung cancer

The aim of this work was to determine the expression of the ERβ (estrogen receptor β) and multidrug resistance, namely MDR1 (P-glycoprotein, P-gp), in 152 samples of non-small cell lung cancer. The expression pattern of ERβ and MDR1 were assessed by the quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry. We also analyzed the correlation between ERβ and MDR1 with clinical and pathological data. The co-expression pattern of ERβ and individual MDR1 proteins was assessed by correspondence analysis and chi-squared tests. In the present study, we found that patients with tumor stage I-II showed higher ERβ mRNA expression levels and decreased expression of ERβ protein with increasing tumor grade, which is opposite to MDR1 expression. In addition, an opposite co-expression pattern of ERβ and individual MDR1 proteins was also observed. In conclusion, the results can be used to better understand the expression control of MDR1 and may allow for the establishment of new cancer chemistry strategies that will control P-gp expression in NSCLC.

Clinical significance of isoagglutinin titre with the current desensitization protocol in ABO-incompatible kidney transplantation

AIM

ABO-incompatible (ABOi) kidney transplantation (KT) has become a routine procedure with graft survival rates comparable to those of ABO-compatible KT. However, the clinical significance of the isoagglutinin titre in ABOi KT remains uncertain. Therefore, in this study, we analysed the clinical outcomes of ABOi KT according to the baseline and post-operative isoagglutinin titre.

METHODS

All patients who received ABOi KT between 2009 and 2013 were reviewed and followed up until December 2016. The patients were classified according to baseline (<1:128 or ≥1:128) and post-operative rebound isoagglutinin titre (<1:16 or ≥1:16), and the clinical outcomes of KT were compared.

RESULTS

Patients with a high baseline isoagglutinin titre showed a poor titre reduction rate (1.48 ± 0.41 vs 1.32 ± 0.34, P = 0.008), and more patients experienced titre rebound ≥1:16 after KT (15.0% vs 35.8%, P = 0.002). The occurrence of both T-cell-mediated rejection and antibody-mediated rejection did not show a significant difference (P = 0.805 and 0.714, respectively). The rate of rejection-free survival was not different among groups (P = 0.680, log-rank test). Furthermore, the rate of death-censored graft survival was not different among groups (P = 0.701, log-rank test). Urinary tract infection was the most frequently reported infectious complication overall. The incidence of urinary tract infection, pneumonia and viral infections (BK virus and cytomegalovirus) was not different among groups.

CONCLUSION

In conclusion, high baseline isoagglutinin titre was associated with a high rebound isoagglutinin titre, low titre reduction rates and more sessions of plasmapheresis. However, the isoagglutinin titre may not be as important as it was in the past in ABOi KT if appropriate desensitization is performed.

A Case Series of Asymptomatic Hemodialysis Catheter-Related Right Atrial Thrombi That Are Incidentally Detected Prior to Kidney Transplantation

A hemodialysis (HD) catheter-related right atrial thrombus (RAT) is rarely encountered prior to kidney transplantation (KT) but necessitates a decision about whether to anticoagulate and/or delay the surgery. There is controversy surrounding the clinical implications of a RAT in this situation. It is sometimes considered fatal but other opinions consider it to be benign, especially when incidentally detected. We reviewed the clinical characteristics, management, and outcomes of a patient series with HD catheter-related RAT detected prior to KT and speculated on its clinical significance. Among 3677 cases of KT performed on 3607 patients between January 1997 and September 2015 in our single tertiary center, 11 cases of HD catheter-related RAT detected on transthoracic echocardiography (TTE) prior to KT were included for analysis. The average maximal diameter of the RAT was 23.2 ± 16.3 (SD in mm) and 9 (81.8%) of these 11 patients had no symptoms associated with the RAT. Four patients (36.3%) had their catheters replaced, 5 patients (45.5%) had their catheters removed, and the catheters were maintained in the remaining 2 patients (18.2%). Six patients (54.5%) were anticoagulated with either heparin or warfarin. However all 11 patients had a successful KT suggesting that a HD catheter-related RAT incidentally detected prior to this surgery may not be as serious as previously considered and should not be a reason for delaying the transplantation.

Ectodomain Shedding of RAGE and TLR4 as a Negative Feedback Regulation in High-Mobility Group Box 1-Activated Aortic Endothelial Cells

BACKGROUND/AIMS

High-mobility group box 1 (HMGB1) elicits inflammatory responses through interactions with the receptor for advanced glycation end products (RAGE) and toll-like receptor 4 (TLR4). We investigated how RAGE and TLR4 expressions are regulated after HMGB1 stimulation in cultured human aortic endothelial cells (HAECs).

METHODS

RAGE and TLR4 expressions were analyzed by Western blot analysis and immunofluorescence staining. A disintegrin and metalloprotease 17 (ADAM17) activity was measured using a fluorogenic substrate.

RESULTS

Upon treatment with HMGB1, both RAGE and TLR4 began to decrease in cell lysate and remained decreased up to 24 h. The decrease in cellular RAGE and TLR4 was accompanied by an increase of N-terminal fragment of RAGE and TLR4 in culture supernatant, indicating ectodomain shedding of the receptors. HMGB1 activated p38 mitogen-activated protein kinase (p38 MAPK) and ADAM17, while HMGB1-induced ADAM17 activation was inhibited by SB203580, a p38 MAPK inhibitor. HMGB1-induced ectodomain shedding of RAGE and TLR4 was prevented by siRNA depletion of ADAM17 as well as TAPI-2, an inhibitor of ADAM family, and SB203580. HMGB1 pretreatment abolished p38 MAPK activation in response to 2nd HMGB1 stimulation. In the cells depleted of ADAM17, HMGB1-induced p38 MAPK activation was prolonged. siRNA depletion of RAGE, but not TLR4, suppressed HMGB1-induced p38 MAPK activation.

CONCLUSION

In response to HMGB1 stimulation, HAECs rapidly undergo ectodomain shedding of RAGE and TLR4, and thereby become insensitive to further HMGB1 stimulation. ADAM17, activated through RAGE-p38 MAPK pathway, is implicated in the ectodomain cleavage of the receptors.

Risk Factors of Acute Rejection in Patients with BK Nephropathy After Reduction of Immunosuppression

Background

BK nephropathy (BKN) affects graft function and increases the risk of graft failure. The reduction of immunosuppression is the main treatment for BKN. However, acute rejection may develop following immunosuppression reduction, and data regarding the risk factors of acute rejection during the post-reduction period are insufficient.

Material/Methods

Of 758 patients who received a kidney transplantation (KT) between 2008 and 2011, 79 who underwent immunosuppression reduction as BKN treatment were enrolled. The risk factors of acute rejection after immunosuppression reduction were identified using multivariate logistic regression analysis.

Results

During the median follow-up period (75 months), acute rejection developed in 21.5% of study group patients and in 22.5% of KT recipients without BKN. The rejection group showed a trend of higher body mass index (24.13±3.92 vs. 22.40±3.31 kg/m², P=0.070) and lower tacrolimus levels than the no rejection group, although mycophenolate mofetil (MMF) doses were not lower in the rejection group. The rejection group showed worse graft survival than the no rejection group (P=0.001 by the log rank test). A greater number of patients in the rejection group exhibited reduced calcineurin inhibitor (CNI) level by >20% at 1 month after initial BKV detection (34.2% vs. 7.9%, P=0.008). Multivariate analysis indicated that the peak BKV PCR level (odds ratio [OR], 0.136; 95% confidence interval [CI], 0.025–0.732; P=0.020), MMF discontinuation (vs. MMF reduction; OR, 0.112; 95% CI, 0.020–0.618; P=0.012) and CNI level reduction >20% (OR, 33.752; 95% CI, 4.263–267.251; P=0.001) were significantly associated with acute rejection.

Conclusions

Acute rejection after immunosuppression reduction for BKN showed worse allograft survival than the patients without acute rejection. In addition, a CNI dose reduction >20% at 1 month after the initial BKV detection can increase the risk of acute rejection.

Use of fludrocortisone for intradialytic hypotension

Intradialytic hypotension during dialysis adversely affects a patient’s prognosis and increases mortality. We report a case in which intradialytic hypotension that persisted after the administration of midodrine was relieved after the use of fludrocortisone. Administration of 0.2 mg of fludrocortisone occurred 30 minutes before dialysis. We compared 45 sessions of dialysis without fludrocortisone administration and 45 sessions of dialysis with fludrocortisone administration in one patient. The number of times in which systolic blood pressure became lower than 80 mmHg and the number of early terminations of dialysis due to a decrease in systolic blood pressure were higher in the sessions without fludrocortisone administration than in the sessions with fludrocortisone administration (P < 0.05). Fludrocortisone may be helpful for the treatment of intradialytic hypotension that does not respond to midodrine administration.

Outcomes of living donor kidney transplantation in diabetic patients: age and sex matched comparison with non-diabetic patients

BACKGROUND/AIMS

Kidney transplantation (KT) reportedly provides a significant survival advantage over dialysis in diabetic patients. However, KT outcome in diabetic patients compared with that in non-diabetic patients remains controversial. In addition, owing to recent improvements in the outcomes of KT and management of cardiovascular diseases, it is necessary to analyze outcomes of recently performed KT in diabetic patients.

METHODS

We reviewed all diabetic patients who received living donor KT between January 2008 and December 2011. Each patient was age- and sex-matched with two non-diabetic patients who received living donor KT during the same period. The outcomes of living donor KT were compared between diabetic and non-diabetic patients.

RESULTS

Among 887 patients, 89 diabetic patients were compared with 178 non-diabetic patients. The incidence of acute rejection was not different between the diabetic and non-diabetic patients. Urinary tract infection and other infections as well as cardiovascular events occurred more frequently in diabetic patients. However, diabetes, cardiovascular disease, and infection were not significant risk factors of graft failure. Late rejection (acute rejection after 1 year of transplantation) was the most important risk factor for graft failure after adjusting for diabetes mellitus (DM), human leukocyte antigen mismatch, rejection and infection (hazard ratio, 56.082; 95% confidence interval, 7.169 to 438.702; p < 0.001). Mortality was not significantly different between diabetic and non-diabetic patients (0 vs. 2, p = 0.344 by log-rank test).

CONCLUSIONS

End-stage renal disease patients with DM had favorable outcomes with living donor kidney transplantation.

ADAM17-Mediated Ectodomain Shedding of Toll-Like Receptor 4 as a Negative Feedback Regulation in Lipopolysaccharide-Activated Aortic Endothelial Cells

BACKGROUND/AIMS

Lipopolysaccharide (LPS)-activated monocytes/macrophages develop endotoxin tolerance in part by reducing cell surface toll-like receptor 4 (TLR4) through cluster of differentiation 14 (CD14)-dependent endocytosis. In case of endothelial cells, CD14 is expressed in low copy numbers as compared with monocytes/macrophages. Thus, we explored how endothelial cells regulate TLR4 expression after LPS stimulation.

METHODS

Cultured human aortic endothelial cells (HAECs) were treated with LPS. TLR4 expression was analyzed by Western blot analysis and immunofluorescence staining. A disintegrin and metalloprotease 17 (ADAM17) activity was measured using a fluorescent substrate.

RESULTS

TLR4 in cell lysate began to decrease within 30 min of LPS treatment with a maximal reduction at 2 h, and it was accompanied by an increase of N-terminal fragment of TLR4 in culture supernatant, indicating ectodomain shedding of the receptor. LPS activated p38 mitogen-activated protein kinase (p38 MAPK) and ADAM17, while LPS-induced ADAM17 activation was inhibited by SB203580, a p38 MAPK inhibitor. LPS-induced ectodomain shedding of TLR4 was attenuated by siRNA depletion of ADAM17 as well as TAPI-2 (an inhibitor of ADAM family) and SB203580. LPS pretreatment resulted in a blunted response of p38 MAPK activation to further LPS stimulation. In the cells depleted of ADAM17, LPS-induced p38 MAPK activation was prolonged and LPS-induced intercellular adhesion molecule-1 expression was potentiated.

CONCLUSION

HAECs respond to LPS by rapid shedding of the ectodomain of TLR4 and thereby reduce the responsiveness to subsequent LPS exposure. ADAM17, downstream of p38 MAPK, is implicated in the ectodomain cleavage of TLR4.

Efficacy and Safety of Febuxostat in Kidney Transplant Patients

OBJECTIVES

Febuxostat, a nonpurine xanthine oxidase, is known to be effective and safe, even in patients with chronic kidney disease. However, there are insufficient data about the efficacy and safety of febuxostat in kidney transplant patients.

MATERIALS AND METHODS

We reviewed medical records of all kidney transplant patients who were prescribed febuxostat between August 2012 and May 2015 at Asan Medical Center in Seoul, Korea. The efficacy and safety results of febuxostat in transplant patients were evaluated. To compare the efficacy of febuxostat, results of kidney transplant patients who were prescribed benzbromarone or allopurinol for more than 1 year during the same period were also reviewed.

RESULTS

Thirty-one patients were included in this study. The initial serum uric acid level of 481.83 ± 143.36 μmol/L decreased to 302.18 ± 150.50 μmol/L after 1 month of febuxostat use. Only 1 patient had altered sense of taste after taking febuxostat, but this symptom quickly improved and he continued treatment. No other adverse events were reported. In addition, at 12 months, mean serum uric acid levels were 280.77 ± 78.52 μmol/L in the febuxostat, 332.52 ± 72.57 μmol/L in the benzbromarone, and 363.45 ± 60.08 μmol/L in the allopurinol group. However, we found no apparent effect on estimated glomerular filtration rate (P = .344). The mean doses of febuxostat, benzbromarone, and allopurinol were 52.31 ± 5.33 mg/day, 42.19 ± 1.69 mg/day, and 146.67 ± 16.52 mg/day.

CONCLUSIONS

Febuxostat reduced serum uric acid levels effectively in kidney transplant patients without severe adverse events.

Diosgenin, an Activator of 1,25D3-MARRS Receptor/ERp57, Attenuates the Effects of TNF-α by Causing ADAM10-Dependent Ectodomain Shedding of TNF Receptor 1

BACKGROUND/AIMS

We investigated how diosgenin, a steroidal sapogenin, has anti-tumor necrosis factor-α (TNF-α) effects in human aortic endothelial cells (HAECs).

METHODS

Tumor necrosis factor receptor 1 (TNFR1) was assessed by Western blot analysis. Intracellular Ca2+ was measured using Fluo-4 AM. Immunofluorescence staining was performed for a disintegrin and metalloprotease 10 (ADAM10).

RESULTS

Diosgenin (1 ∼ 100 nM) induced ectodomain shedding of TNFR1 within 30 min and attenuated TNF-α-induced intercellular adhesion molecule-1 (ICAM-1) expression. Upon treatment with diosgenin, extracellular Ca2+ entered into the cells via L-type calcium channels, whereas diosgenin-induced ectodomain shedding of TNFR1 was almost completely inhibited by BAPTA-AM (intracellular Ca2+ chelator), verapamil (L-type calcium channel antagonist) and the absence of extracellular Ca2+. Diosgenin caused translocation of ADAM10 to the cell surface, which was mediated by extracellular Ca2+ influx. Depletion of ADAM10 prevented diosgenin-induced ectodomain shedding of TNFR1 and abolished the inhibitory effect of diosgenin on TNF-α-induced ICAM-1 expression. Diosgenin did not induce extracellular Ca2+ influx and ectodomain shedding of TNFR1 in cells depleted of 1,25D3-membrane associated rapid response steroid-binding receptor (1,25D3-MARRS receptor/ERp57).

CONCLUSION

Diosgenin elicits L-type calcium channel-mediated extracellular Ca2+ influx, and thereby induces ADAM10-mediated ectodomain shedding of TNFR1. This effect of diosgenin was exerted through 1,25D3-MARRS receptor/ERp57.

Risk factors and long-term outcomes of parvovirus B19 infection in kidney transplant patients

BACKGROUND

Parvovirus B19 is a small, non-enveloped, single-stranded DNA virus with a special affinity for the erythroid progenitor cells of the bone marrow. The first case of parvovirus B19 infection in a kidney transplant recipient (KTR) was reported in 1986. Data on the risk factors and specific clinical characteristics of parvovirus B19 infection remain insufficient.

METHODS

We screened 602 KTRs for parvovirus B19 infection using parvovirus B19 polymerase chain reaction (PCR) from January 1990 to April 2016, and the clinical characteristics of patients with positive results were compared to those of age- and gender-matched patients with negative PCR results.

RESULTS

A total of 39 KTRs tested positive for parvovirus B19, and they were compared to 78 age- and gender-matched patients among 563 KTRs who had negative PCR results. In all, 89.7% of positive cases were reported within the first year after kidney transplantation. In multivariate analyses, deceased-donor kidney transplantation (odds ratio [OR] 9.067, 95% confidence interval [CI] 1.668-49.275, P = .011), use of tacrolimus (OR 3.607, 95% CI 1.024-12.706, P = .046), PCR test within 1 year of kidney transplantation (OR 12.456, 95% CI 2.674-58.036, P = .001), and hemoglobin levels (OR 0.559, 95% CI 0.351-0.889, P = .014) showed significant correlations with parvovirus B19 infection. Graft survival did not differ between the two groups during the follow-up period of 111.68 ± 54.54 months (P = .685 by log-rank test).

CONCLUSION

The identification of factors related to positive parvovirus B19 PCR results may promote the early detection of parvovirus B19 infection. Further studies are needed to elucidate the characteristics of parvovirus B19 infection in kidney transplantation.

Differential Characteristics of Kidney Transplant Recipients According to 1-Year Chronic Kidney Disease Stage 3a and Stage 3b Graft Function

The outcomes of transplantation have improved, but more than 50% of kidney transplantation (KT) recipients are still reported to have renal function of chronic kidney disease (CKD) stage 3 at 1 year after KT. We reviewed all 1235 patients who received a KT in our institution between 2008 and 2012. Among these recipients, 77 and 289 cases were included in the estimated glomerular filtration rate (eGFR) at 1 year after KT 30-44 (CKD stage 3b) group and eGFR 45-59 (CKD stage 3a) group, respectively. Longer duration of dialysis (odds ratio [OR] = 1.007, 95% confidence interval [CI], 1.000-1.014, P = 0.047), older donors (OR = 1.064, 95% CI, 1.031-1.098, P < 0.001), delayed graft function (OR = 3.601, 95% CI, 1.031-1.098, P < 0.001), BK virus infection (OR = 2.567, 95% CI, 1.242-5.305, P = 0.011), and pneumonia (OR = 4.451, 95% CI, 1.388-14.279, P = 0.012) were contributing factors to eGFR 30-44 mL/min. Especially, ureteral stricture occurred more frequently in eGFR 30-44 group of deceased donor KT. However, acute rejection was not a significant risk factor of lower eGFR. Graft survival was better in the eGFR 45-59 group. However, this difference was smaller in deceased donor KT. Infections and urologic complications are also important contributing factors of lower graft function in CKD stage 3. In addition, dividing CKD stage 3 into subgroups might be more useful in living donor kidney transplantation.

A postoperative 1-Year eGFR of More Than 45 ml/min May be the Cutoff Level for a Favorable Long-Term Prognosis in Renal Transplant Patients

BACKGROUND One-year renal function after kidney transplantation (KT) classified by the Kidney Disease: Improving Global Outcomes (KDIGO) chronic kidney disease (CKD) staging has been reported to be associated with graft survival. However, the outcomes of KT are improving. Therefore, the distribution and prognostic value of 1-year estimated glomerular filtration rate (eGFR) in recently performed transplants were re-evaluated in this study. MATERIAL AND METHODS We reviewed all patients who received KT between 2008 and 2011 at our institution, and followed them until June 2015. The distribution of 1-year eGFR, graft survival according to CKD staging, the cutoff level for a favorable prognosis, and the occurrence of rejection and infection were analyzed. RESULTS A total of 758 patients were included in this study. Unlike previous studies, most patients (56.2%) were in the CKD stage 2 (eGFR 60-89) rather than stage 3 (eGFR 30-59). In addition, the CKD stage 3a (eGFR 45-59) group showed better graft survival than the CKD stage 3b (eGFR 30-44) group. However, CKD stage 2 and CKD stage 3a groups did not show significant differences in graft survival. Patients with postoperative 1-year eGFR ≥45 ml/min showed a more favorable outcome compared with those with postoperative 1-year eGFR <45 ml/min. One-year eGFR<45 ml/min, acute cellular rejection, antibody-mediated rejection, and CMV infection after 1 year were adjusted risk factors for graft failure. CONCLUSIONS A 1-year eGFR ≥45 ml/min may be the appropriate cutoff level for predicting favorable outcomes in KT. In addition, KDIGO CKD staging may no longer be useful in recently performed KT.

Usefulness of Tacrolimus without Basiliximab in Well-Matched Living-Donor Renal Transplant Recipients in Korea

OBJECTIVES

Basiliximab is used alongside tacrolimus-based immunosuppression for routine induction therapy, even for well-matched living-donor renal transplant recipients. Because tacrolimus is a different drug from cyclosporine, this study examined the utility of tacrolimus-based immunosuppression without basiliximab for well-matched living-donor renal transplant recipients.

MATERIALS AND METHODS

This prospective study evaluated 36 patients who underwent 1 to 3 human leukocyte antigens mismatched living-donor renal transplants without basiliximab induction therapy between April 2012 and March 2015 (group 1). All transplants were ABO compatible and T-flow negative and were followed until April 2015. Tacrolimus-based triple therapy was used for maintenance immunosuppression. The control group comprised 72 age- and sex-matched patients who underwent 1 to 3 human leukocyte antigens mismatched living-donor renal transplants with basiliximab induction therapy during the same period (group 2).

RESULTS

Two patients in group 1 and 12 patients in group 2 had infection,with cytomegalovirus infection and Pneumocystis pneumonia infection occurring only in group 2 and BK virus and urinary tract infection reported in both groups, with a similar incidence. One patient from group 2 had sepsis. Although the incidence of infection tended to be lower in group 1 than in group 2 (5.6% vs 16.7%), the overall incidence of infection was not significantly different (P=.135). In addition, there were no significant differences in incidence of acute rejection between groups 1 and 2 (2.8% vs 4.2%; P=.699). All patients showed stable renal function after treatment.

CONCLUSIONS

Tacrolimus-based triple drug maintenance immunosuppression without basiliximab might be an optimal treatment choice for individuals undergoing well-matched living-donor renal transplant.

TNF-α Activates High-Mobility Group Box 1 - Toll-Like Receptor 4 Signaling Pathway in Human Aortic Endothelial Cells

BACKGROUND/AIMS

Toll-like receptor 4 (TLR4) interacts with endogenous substances as well as lipopolysaccharide. We explored whether TLR4 is implicated in tumor necrosis factor-α (TNF-α) signal transduction in human aortic endothelial cells.

METHODS

The pathway was evaluated by transfection of siRNAs, immunoprecipitation and Western blot analysis.

RESULTS

TNF-α activated spleen tyrosine kinase (Syk) within 10 min, which led to endothelin-1 (ET-1) production. TLR4 was also rapidly activated by TNF-α stimulation, as shown by recruitment of interleukin-1 receptor-associated kinase 1 to TLR4 and its adaptor molecule, myeloid differentiation factor 88 (MyD88). siRNA depletion of TLR4 markedly attenuated TNF-α-induced Syk activation and ET-1 production. TLR4 inhibitor (CLI-095), TLR4-neutralizing antibody and siRNA depletion of MyD88 also attenuated TNF-α-induced Syk activation. Syk was co-immunoprecipitated with TLR4, and TNF-α activated Syk bound to TLR4. High-mobility group box 1 (HMGB1) was rapidly released and associated with TLR4 after TNF-α stimulation with a peak at 5 min, which was prevented by N-acetylcysteine, an antioxidant. Glycyrrhizin (HMGB1 inhibitor), HMGB1-neutralizing antibody and siRNA depletion of HMGB1 all suppressed TNF-α-induced Syk activation and ET-1 production.

CONCLUSION

Upon TNF-α stimulation, TLR4 is activated by HMGB1 that is immediately released after the generation of reactive oxygen species, and plays a crucial role in the signal transduction.

Epigallocatechin-3-Gallate Attenuates the Effects of TNF-α in Vascular Endothelial Cells by Causing Ectodomain Shedding of TNF Receptor 1

Background/Aims: We investigated the mechanism underlying anti-tumor necrosis factor-α (TNF-α) effects of epigallocatechin-3-gallate (EGCG) in human aortic endothelial cells. Methods: Tumor necrosis factor receptor 1 (TNFR1) was assessed by Western blot analysis. Cytosolic Ca2+ was measured using Fluo-4 AM. A disintegrin and metalloprotease 10 (ADAM10) was localized by immunofluorescence staining. Results: EGCG caused ectodomain shedding of TNFR1 within 30 min and attenuated TNF-α-induced endothelin-1 (ET-1) expression. EGCG-induced TNFR1 ectodomain shedding was prevented by BAPTA-AM (intracellular Ca2+ chelator), but not by the absence of extracellular Ca2+. In physiologic extracellular Ca2+ concentration, EGCG markedly increased cytosolic Ca2+. Even in the absence of extracellular Ca2+, EGCG raised cytosolic Ca2+, though less potently. siRNA depletion of ADAM10 prevented EGCG-induced ectodomain shedding of TNFR1 and also diminished the inhibitory effect of EGCG on TNF-α-induced ET-1 expression. EGCG caused translocation of ADAM10 to the plasma membrane, and this effect was prevented by BAPTA-AM. Besides extracellular Ca2+ influx, release of intracellular stored Ca2+ caused ADAM10-dependent ectodomain shedding of TNFR1. Conclusion: EGCG decreases the responsiveness of cells to TNF-α by causing ADAM10-dependent ectodomain shedding of TNFR1. This effect was attributed to its property to increase cytosolic Ca2+ through both extracellular Ca2+ influx and release of stored Ca2+.

Late-onset IgA vasculitis in adult patients exhibits distinct clinical characteristics and outcomes

OBJECTIVES

The aim of this study was to determine whether adult IgA vasculitis patients who developed the disease at an older age differ from early-onset patients in terms of clinical features and outcomes.

METHODS

All consecutive adult patients who were diagnosed with IgA vasculitis between January 1997 and December 2014 were reviewed retrospectively. Patients who developed the disease at an older age (≥60 years; late-onset) were compared with those with an earlier onset of disease (<60 years; early-onset). Renal insufficiency was defined as an estimated glomerular filtration rate <60 ml/minute.

RESULTS

In total, 100 adult patients were diagnosed with IgA vasculitis (mean age, 45.61 ± 17.24 years), of whom 31 (31%) had late-onset disease. Compared to early-onset patients, late-onset patients were less likely to have a preceding upper respiratory tract infection (0/31, 0.0% vs. 14/69, 20.3%; p=0.004), and more likely to have renal involvement at presentation (27/31, 87.1% vs. 43/69, 62.3%; p=0.017). At the last follow-up visit, late-onset patients were more likely to have chronic renal insufficiency, including end-stage renal disease (18/28, 64.3% vs. 7/62, 11.3%; p=0.000). Multivariate Cox analysis revealed that late-onset was a significant risk factor for renal insufficiency at follow-up (hazard ratio, 16.980, 95% confidence intervals, 4.380-65.830; p=0.000).

CONCLUSIONS

Patients with late-onset IgA vasculitis in adults exhibit distinct clinical features characterized by greater renal involvement and worse renal outcomes. Thus, watchful follow-up might be needed for adult IgA vasculitis patients, in particular those with late-onset disease.

Loss of cysteinyl-tRNA synthetase (CARS) induces the transsulfuration pathway and inhibits ferroptosis induced by cystine deprivation

Ferroptosis is a form of regulated non-apoptotic cell death that has been implicated in several disease contexts. A better understanding of the ferroptotic death mechanism could lead to the development of new therapeutics for degenerative diseases, and a better understanding of how to induce ferroptosis in specific tumor contexts. We performed an unbiased genome-wide siRNA screen to find genetic suppressors of ferroptosis. We determined that loss of CARS, the cysteinyl-tRNA synthetase, suppresses ferroptosis induced by erastin, which inhibits the cystine-glutamate antiporter known as system xc(-). Knockdown of CARS inhibited erastin-induced death by preventing the induction of lipid reactive oxygen species, without altering iron homeostasis. Knockdown of CARS led to the accumulation of cystathionine, a metabolite on the transsulfuration pathway, and upregulated genes associated with serine biosynthesis and transsulfuration. In addition, inhibition of the transsulfuration pathway resensitized cells to erastin, even after CARS knockdown. These studies demonstrate a new mechanism of resistance to ferroptosis and may lead to strategies for inducing and suppressing ferroptosis in diverse contexts.

Vitamin D-induced ectodomain shedding of TNF receptor 1 as a nongenomic action: D3 vs D2 derivatives

As a nongenomic action, 1,25-dihydroxyvitamin D3 (1,25D3) induces L-type Ca(2+) channel-mediated extracellular Ca(2+) influx in human aortic smooth muscle cells (HASMCs), which activates a disintegrin and metalloprotease 10 (ADAM10) to cleave and shed the ectodomain of tumor necrosis factor receptor 1 (TNFR1). In this study, we examined the potencies of other vitamin D3 and D2 analogs to stimulate the ectodomain shedding of TNFR1 in HASMCs. 25-Hydroxyvitamin D3 (25D3), a precursor of 1,25D3, and elocalcitol, an analog of 1,25D3, caused ectodomain shedding of TNFR1 within 30 min, whereas 1,25-dihydroxyvitamin D2 (1,25D2) and paricalcitol, a derivative of 1,25D2, did not. Both 25D3 and elocalcitol rapidly induced extracellular Ca(2+) influx and markedly increased intracellular Ca(2+), while 1,25D2 and paricalcitol caused only small increases in intracellular Ca(2+). 25D3- and elocalcitol-induced TNFR1 ectodomain sheddings were abolished by verapamil and in Ca(2+)-free media. Both 25D3 and elocalcitol caused the translocation of ADAM10 to the cell surface, which was inhibited by verapamil, while 1,25D2 and paricalcitol did not cause ADAM10 translocation. When ADAM10 was depleted by ADAM10-siRNA, 25D3 and elocalcitol could not induce ectodomain shedding of TNFR1. The plasma membrane receptor, endoplasmic reticulum stress protein 57 (ERp57), but not the classic vitamin D receptor, mediated the nongenomic action of vitamin D to induce ectodomain shedding of TNFR1. In summary, like 1,25D3, 25D3 and elocalcitol caused ADAM10-mediated ectodomain shedding of TNFR1, whereas 1,25D2 and paricalcitol did not. The difference may depend on their affinities to ERp57 through which extracellular Ca(2+) influx is induced.

ApoE and S-100 expression and its significance in the brain tissue of rats with focal contusion

This study explored the effect of focal cerebral contusion on the expression of ApoE and S-100, and its significance in determining the time of brain injury. Based on a rat model of cerebral contusion, immunohistochemistry was used to analyze the expressions of S-100 and ApoE at different time points after injury. Thirty minutes following cerebral contusion, ApoE protein expression was significantly increased in cortex neurons (P < 0.01), and S-100 protein expression was significantly (P < 0.001) elevated 2 h after cerebral contusion. Over time, the number of ApoE and S-100 positively expressing cells gradually increased. Three days after injury, ApoE was widely distributed throughout the tissue and the number of ApoE-positive cells and staining intensity reached a peak. ApoE expression decreased after this time point. Five days after cerebral contusion, the number of S-100-positive cells reached a peak level of expression higher than that in the control group. Our data demonstrate that the expression of ApoE and S-100 correlated with the progression of focal cerebral contusion. This suggests that both proteins may serve as effective biomarkers of focal cerebral contusions.

Low dose of mycophenolate mofetil is enough in desensitized kidney transplantation using rituximab

Background

Rituximab is widely used in kidney transplantation. However, it is not clear whether the conventional doses of maintenance immunosuppressant in rituximab-treated kidney transplantation (KT) are appropriate. In our previous study, decreasing mycophenolate mofetil (MMF) dose due to infection did not increase the incidence of rejection or graft failure. Based on these experiences, we developed a new protocol with a lower dose of MMF and studied its clinical outcomes in rituximab-treated KT.

Methods

We enrolled all patients who underwent ABO-incompatible or human leukocyte antigen (HLA)-sensitized living donor KT with the new immunosuppressant protocol after preconditioning with rituximab, but without splenectomy from November 2011 to May 2013. Seventy-two patients (group 1) were consecutively enrolled in this study and followed until November 2013. Patients from our previous study served as control groups. Sixty-seven patients received KT using rituximab with a conventional dose of MMF (group 2), and 87 patients received ABO compatible KT without need for rituximab (group 3). Clinical outcomes, including rejection, infection, and graft survival, were compared between the groups. The χ² test and Fisher’s exact test were used for categorical variables, the Student’s t-test and Mann-Whitney U test were used for continuous variables, and a log-rank test was used for mortality analysis.

Results

Doses of postoperative MMF (g/day) were lower in group 1 than in the other groups (1.03 ± 0.19, 1.48 ± 0.34 and 1.48 ± 0.32 g/day at 1 week, p < 0.001). Infectious complications occurred more often in groups with conventional MMF doses (group 2 and 3) than in group 1 (16.7 vs. 37.3 %, p = 0.007 and 16.7 vs. 34.5 %, p = 0.012, respectively). Notably, group 1 showed a lower incidence of cytomegalovirus infection than group 2. However, reduction in MMF dose did not increase the incidence of acute rejection (4.2, 4.5 and 10.3 %). Only one graft failure occurred in group 2 due to vessel kinking after operation. There were no significant differences in the incidence of malignancy and mortality between groups.

Conclusions

A low MMF dose reduces infection without increasing rejection or graft loss and it may be appropriate to reduce the dose of MMF for rituximab-treated KT patients.