Association between Pentosan Polysulfate and Subsequent Maculopathy: Insights from a Nationwide Population-Based Study in Korea.

PURPOSE: To determine the association between pentosan polysulfate (PPS) use and the subsequent development of maculopathy in Asian population. DESIGN: A nationwide population-based retrospective cohort study using the Health Insurance Review and Assessment Service database. PARTICIPANTS: 103,553 individuals in the PPS user group and 205,792 individuals in the PPS non-user group, all newly diagnosed with cystitis between 2009 and 2020. METHODS: The association between PPS use and maculopathy was evaluated using a time dependent Cox proportional hazard model. Additionally, two sensitivity analyses were conducted by defining PPS users as individuals with an observation period over 6 months from the initial prescription or those with cumulative dose exceeding 9 g, employing the same analysis. MAIN OUTCOME MEASURES: The outcome measures included the hazard ratios (HR) representing the association between PPS use and maculopathy. RESULTS: PPS use was associated with an increased risk of subsequent maculopathy in univariate (HR, 1.7; 95% confidence intervals [CI], 1.66-1.75) and multivariate analysis (HR, 1.34; 95% CI, 1.31-1.38). These results were also confirmed in two sensitivity analyses. The mean cumulative dose of PPS for the cohort was 37.2 ± 76.7 g. CONCLUSIONS: In this nationwide cohort study involving an Asian population, individuals with cystitis using PPS exhibit an increased risk of developing subsequent maculopathy.

INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT IN PATIENTS WITH NEOVASCULAR AGE-RELATED MACULAR DEGENERATION AND POOR VISUAL ACUITY.

PURPOSE: To investigate the significance of intravitreal anti-vascular endothelial growth factor treatment in patients with neovascular age-related macular degeneration and poor visual acuity. METHODS: Retrospective study of patients with neovascular age-related macular degeneration with baseline best-corrected visual acuity of ≤20/200. Patients were divided into regular treatment and scarce treatment groups according to whether they underwent consecutive intravitreal anti-vascular endothelial growth factor treatments at intervals of ≤4 months or not. RESULTS: A total of 131 eyes were included: 87 and 44 eyes in the regular treatment and scarce treatment groups, respectively. The regular treatment group showed significantly improved preservation of lesion size at both Years 1 and 2, with significantly fewer incidences of new subretinal hemorrhage. Improvements in visual acuity, reduction in central subfield macular thickness, and maximal height of choroidal neovascularization were significantly favorable in the regular treatment group at Year 1, and central subfield macular thickness was significantly decreased at Year 2. Survival analysis revealed that the regular treatment group had significantly greater preservation of visual acuity and lesion size than that in the scarce treatment group. CONCLUSION: Maintaining intravitreal anti-vascular endothelial growth factor treatment for patients with neovascular age-related macular degeneration and poor vision showed significant advantages in visual acuity and lesion size stability and reduced the incidence of new subretinal hemorrhage, which suggests preservation of paracentral vision.

Clipless internal mammary artery harvesting for minimally invasive coronary artery bypass grafting using the shear-tip harmonic scalpel.

Background: The internal mammary artery (IMA) is the most commonly used graft in coronary artery bypass grafting (CABG) because of its superior long-term patency rate. However, its small diameter poses challenges in handling, and any vascular damage that may occur during harvesting can significantly affect surgical outcomes. The primary focus during IMA harvesting is to ensure safe and effective hemostasis without direct vascular injury, while ensuring secure and reliable ligation of the vascular branches. Various methods using multiple surgical instruments have been used for this purpose. Unlike traditional instruments, the shear-tip Harmonic scalpel offers more precise vessel branching control, while minimizing damage to surrounding tissues. In this study, we assessed the utility of the shear-tip Harmonic scalpel in patients undergoing minimally invasive coronary artery bypass grafting (MICABG). Methods: From April 2019 to May 2023, a total of 40 patients underwent MICABG. The IMA was harvested using the shear-tip Harmonic scalpel with a clipless skeletonized technique. In this cohort, 5 patients underwent complete endoscopic harvesting, while 34 patients underwent direct visualization harvesting through minimal thoracotomy. Graft patency was assessed by measuring a Doppler flowmeter in the bypass conduit. Results: Successful graft patency was achieved in all patients. The mean duration of IMA harvesting was 87 min. In total, 38 of the 40 patients underwent MICABG without the need for cardiopulmonary bypass, ensuring a stable procedure. There were no graft-related events or complications observed in any of the patients, and all were discharged without any issues. During a median follow-up period of 15.2 months, only one patient experienced graft occlusion necessitating intervention. Conclusions: The utilization of shear-tip Harmonic scalpel for IMA harvesting in MICABG is feasible and yields stable early results.

Trends and Barriers in Diabetic Retinopathy Screening: Korea National Health and Nutritional Examination Survey 2016-2021.

BACKGROUND: The prevalence of diabetes is increasing globally, highlighting the importance of preventive healthcare. This study aimed to identify the diabetic retinopathy (DR) screening rates and risk factors linked to DR screening nonadherence in the Korean population through a nationally representative sample survey. METHODS: Among the Korea National Health and Nutrition Examination Survey database from 2016 to 2021, participants aged ≥ 40 years with diabetes were included. The weighted estimate for nonadherence to DR screening within a year was calculated. Risk factor analyses were conducted using univariate and multivariate logistic regression. RESULTS: Among the 3,717 participants, 1,109 (29.5%) underwent DR screening within the past year, and this national estimate exhibited no statistically significant difference from 2016 to 2021 (P = 0.809). Nonadherence to annual DR screening was associated with residing in rural areas, age ≥ 80 years, low educational level, self-reported good health, absence of ocular disease, current smoking, lack of exercise and dietary diabetes treatment, and no activity limitation (all P < 0.05). CONCLUSION: The recent DR screening rate in Korea was relatively low. Factors associated with apathy and complacency towards personal health were associated with the nonadherence to DR screening. Educational interventions have the potential to enhance the annual screening rate for diabetic patients.

Phase Transitions and Thermoelectric Properties of Charge-Compensated ZnxCu12-xSb4Se13.

In this study, we investigated the phase transitions and thermoelectric properties of charge-compensated hakite (ZnxCu12-xSb4Se13) as a function of Zn content. Based on X-ray diffraction and a differential scanning calorimetric phase analysis, secondary phases (permingeatite and bytizite) transformed into hakite depending on the Zn content, while Zn2Cu10Sb4Se13 existed solely as hakite. Nondegenerate semiconductor behavior was observed, exhibiting increasing electrical conductivity with a rising temperature. With an increase in Zn content, the presence of mixed phases of hakite and permingeatite led to enhanced electrical conductivity. However, Zn2Cu10Sb4Se13 with a single hakite phase exhibited the lowest electrical conductivity. The Seebeck coefficient exhibited positive values, indicating that even after charge compensation (electron supply) by Zn, p-type semiconductor characteristics were maintained. With the occurrence of an intrinsic transition within the measured temperature range, the Seebeck coefficient decreased as the temperature increased; at a certain temperature, Zn2Cu10Sb4Se13 exhibited the highest value. Thermal conductivity showed a low temperature dependence, obtaining low values below 0.65 Wm-1K-1. A power factor of 0.22 mWm-1K-2 and dimensionless figure of merit of 0.31 were achieved at 623 K for ZnCu11Sb4Se13.

Triggered saccadic oscillations: case series and review of the literature.

Saccadic oscillations (SOs) mostly occur spontaneously, but can be occasionally triggered by various stimuli. To determine clinical characteristics and underlying mechanisms of triggered SOs, we analyzed the clinical features and quantitative eye-movement recordings of six new patients and 10 patients in the literature who exhibited with triggered SOs. Eleven of the 16 patients (69%) had a lesion involving cerebellum and/or brainstem such as cerebellar degeneration, cerebellitis, or cerebellar infarction. The other causes were vestibular migraine (n = 2), multiple sclerosis (n = 1), Krabbe disease (n = 1), and idiopathic (n = 1). Vestibular stimulation was the most common trigger (n = 11, 69%), followed by removal of visual fixation (n = 4, 25%), hyperventilation (n = 1), light (n = 1), and blink (n = 1). The types of triggered SOs were varied which included ocular flutter (n = 13), opsoclonus (n = 3), vertical SOs (n = 2), and macrosaccadic oscillations (n = 1). Three patients exhibited downbeat nystagmus either before (n = 1) or after (n = 2) the onset of SOs. The frequency of triggered SOs ranged from 4 to 15 Hz, and oscillations with smaller amplitudes had higher frequencies and smaller peak velocities. SOs can be triggered by the modulation of unstable saccadic neural networks through vestibular and visual inputs in lesions of the brainstem and cerebellum.

Long-term efficacy and safety of brolucizumab in neovascular age-related macular degeneration: A multicentre retrospective real-world study.

PURPOSE: To investigate the long-term efficacy and safety of intravitreal brolucizumab (BRZ) injections in patients with typical neovascular age-related macular degeneration (typical nAMD) and polypoidal choroidal vasculopathy (PCV). METHODS: This multicentre retrospective study included 401 eyes of 398 patients with nAMD who received BRZ injection(s), with a follow-up duration of ≥12 months. Changes in best-corrected visual acuity (BCVA), retinal fluid evaluation and central subfield thickness (CST) on optical coherence tomography were assessed. The efficacy of BRZ was compared between typical nAMD and PCV groups. RESULTS: Analyses were conducted with 280 eyes of 278 patients with typical nAMD and 121 eyes of 120 patients with PCV (mean age, 71.1 ± 8.6 years). 29 eyes (7.2%) were treatment naïve. The mean follow-up period was 15.3 ± 2.8 months; the mean number of BRZ injections within 1 year was 4.5 ± 1.7. BCVA was maintained during the follow-up period, and CST significantly improved from the first injection month and was maintained for 12 months in both the typical nAMD and PCV groups. The dry macula proportion increased from 2.7% at baseline to 56.1% at 1 month and 42.9% at 12 months. Among the 18 eyes that underwent indocyanine green angiography both before and after treatment, 10 (55.6%) showed polyp regression. Overall, the incidence of intraocular inflammation (IOI), retinal vasculitis and occlusive retinal vasculitis was 9.4% (38 eyes), 1.2% (5 eyes) and 0.5% (2 eyes), respectively. IOI occurred from the first to the sixth injections, with an average IOI onset of 28.5 ± 1.4 days. All eyes achieved IOI resolution, although the two eyes with occlusive retinal vasculitis showed a severe visual decline after IOI resolution. CONCLUSION: Brolucizumab was effective in maintaining BCVA and managing fluid in eyes with nAMD for up to 1 year, exhibiting a high polyp regression rate. However, the not uncommon incidence of IOI and the severe visual decline caused by the rare occlusive retinal vasculitis following BRZ treatment underscore the importance of careful monitoring and timely management.

A Comparative Study of Endoscopic versus Percutaneous Epidural Neuroplasty in Lower Back Pain: Outcomes at Six-Month Follow Up.

Background and Objectives: Endoscopic epidural neuroplasty (EEN) facilitates adhesiolysis through direct epiduroscopic visualization, offering more precise neural decompression than that exhibited by percutaneous epidural neuroplasty (PEN). We aimed to compare the effects of EEN and PEN for 6 months after treatment with lower back and radicular pain in patients. Methods: This retrospective study compared the visual analog scale (VAS) and Oswestry disability index (ODI) scores in patients with low back and radicular pain who underwent EEN or PEN with a steering catheter. The medical records of 107 patients were analyzed, with 73 and 34 undergoing EEN and PEN, respectively. Results: The VAS and ODI scores decreased at all time points after EEN and PEN. VAS and ODI scores decreased more in the EEN group than those in the PEN group at 1 day and 1- and 6-months post-procedure, indicating superior pain relief for both lower back and radicular pain through EEN. Conclusions: EEN is a superior treatment of pain control than PEN in lower back and radicular pain patients.

A novel vector field analysis for quantitative structure changes after macular epiretinal membrane surgery.

The aim of this study was to introduce novel vector field analysis for the quantitative measurement of retinal displacement after epiretinal membrane (ERM) removal. We developed a novel framework to measure retinal displacement from retinal fundus images as follows: (1) rigid registration of preoperative retinal fundus images in reference to postoperative retinal fundus images, (2) extraction of retinal vessel segmentation masks from these retinal fundus images, (3) non-rigid registration of preoperative vessel masks in reference to postoperative vessel masks, and (4) calculation of the transformation matrix required for non-rigid registration for each pixel. These pixel-wise vector field results were summarized according to predefined 24 sectors after standardization. We applied this framework to 20 patients who underwent ERM removal to obtain their retinal displacement vector fields between retinal fundus images taken preoperatively and at postoperative 1, 4, 10, and 22 months. The mean direction of displacement vectors was in the nasal direction. The mean standardized magnitudes of retinal displacement between preoperative and postoperative 1 month, postoperative 1 and 4, 4 and 10, and 10 and 22 months were 38.6, 14.9, 7.6, and 5.4, respectively. In conclusion, the proposed method provides a computerized, reproducible, and scalable way to analyze structural changes in the retina with a powerful visualization tool. Retinal structural changes were mostly concentrated in the early postoperative period and tended to move nasally.

Nationwide incidence of congenital and infantile cataract requiring surgery in Korea.

Congenital and infantile (CI) cataract is one of the most important and preventable cause of blindness in children, but the incidence has not been studied in Korea. We collected data from the national claims database of the National Health Insurance Service of Korea from 2002 through 2019. We identified children who underwent cataract surgery within the age of 5 years, and cumulative incidence rates were calculated for each of the three age criteria. 989 patients out of 4,221,459 births underwent surgery with CI cataract during the period. The cumulative incidence rates per 10,000 births were 1.60 (0-1 years), 2.38 (0-3 years), and 2.95 (0-5 years), respectively. The incidence peaked in the 2007 birth cohort, which coincides with the start of the national screening program for infants/children. Primary intraocular lens implantation was performed in 439 patients (44%). Strabismus and glaucoma requiring surgery occurred in 291 patients (29.4%) and 32 patients (3.2%), respectively, within 8 years after cataract surgery. The incidence rates of CI cataract in Korea appear to be comparable to previous studies in other regions. The early screening program for infants may reduce delayed diagnosis and increase the proportion of patients undergoing surgery at a critical time for visual development.

A nationwide study of regional preference and graft survival of kidney transplantation in South Korea: patterns of centralization in the capital area.

Purpose: This study aims to investigate regional patterns and graft survival rates in kidney transplantation (KT) within South Korea using the National Health Insurance Service database. Methods: By analyzing KT data from 2002 to 2017, including patient residency, KT location, and post-KT dialysis information, graft survival was assessed through post-KT dialysis and validated against Ulsan University Hospital and the Korean Organ Transplantation Registry's 2017 report. Results: Among the 20,978 KTs, 60.5% occurred in the Korean capital, Seoul, whereas 39.5% occurred outside. The overall graft survival rate was 81.5% with a median survival duration of 57 months. Patient survival was 83.8%, with a median survival duration of 61 months. For KTs from 2002 to 2007, the 10-year graft and patient survival rates were 89.1% and 90.3%, respectively. The KT recipients living outside Seoul who underwent the KT within their residential regions had a graft survival rate of 88.3%, and those receiving KTs outside their original region had a graft survival rate of 88.0%. Among Seoul residents who underwent KTs in the city, the graft survival rate was 90.5%. Importantly, hospital location did not significantly affect graft survival rates (P = 0.136). Conclusion: This study revealed a regional preference for KT in South Korea, particularly in the capital city, likely because of nonresidents. Nevertheless, the graft and patient survival rates showed no significant regional disparities. These findings emphasize the necessity for equitable KT service access across regions in order to optimize patient outcomes.

Multi-Institutional Collaborative Research Using Ophthalmic Medical Image Data Standardized by Radiology Common Data Model (R-CDM).

Observational Medical Outcome Partners - Common Data Model (OMOP-CDM) is an international standard model for standardizing electronic medical record data. However, unstructured data such as medical image data which is beyond the scope of standardization by the current OMOP-CDM is difficult to be used in multi-institutional collaborative research. Therefore, we developed the Radiology-CDM (R-CDM) which standardizes medical imaging data. As a proof of concept, 737,500 Optical Coherence Tomography (OCT) data from two tertiary hospitals in South Korea is standardized in the form of R-CDM. The relationship between chronic disease and retinal thickness was analyzed by using the R-CDM. Central macular thickness and retinal nerve fiber layer (RNFL) thickness were significantly thinner in the patients with hypertension compared to the control cohort. It is meaningful in that multi-institutional collaborative research using medical image data and clinical data simultaneously can be conducted very efficiently.

Comparison of posterior capsule rupture rates during phacoemulsification using 3D heads-up visualization system and traditional microscopes.

PURPOSE: To compare the posterior capsule rupture (PCR) rates of cataract surgery using a traditional ophthalmic surgical microscope (OSM) and a 3D heads-up visualization system (HUVS). SETTING: Single tertiary referral center. DESIGN: Retrospective study. METHODS: This study included 10 101 eyes that underwent phacoemulsification cataract surgery. Surgeries were performed using either 3D HUVS (1964 eyes, performed by 2 surgeons, HUVS group) or traditional OSM (8137 eyes, performed by 6 surgeons, OSM group) from February 2018 to June 2022. Data were collected based on the diagnosis-related group system, and the rate of PCR requiring vitrectomy and the surgical time were evaluated. RESULTS: The PCR rates were not significantly different between the OSM (n = 63; 0.7%) and HUVS (n = 19; 0.9%, P = .392) groups. The mean surgical time was significantly longer in the HUVS group (14.7 ± 10.6 minutes) than in the OSM group (12.9 ± 9.9 minutes, P < .001). In the 3D HUVS group, there were no PCR cases among the initial 100 patients. In both groups, no significant difference was observed in the PCR rates over time. Although the difference was not statistically significant, the PCR rate decreased over time in the HUVS group. CONCLUSIONS: The results indicate that 3D HUVS-based cataract surgery performed by experienced cataract surgeons had a PCR rate similar to that of traditional OSM-based surgery during the 4-year study period. Although the surgical time was slightly longer with 3D HUVS, cataract surgery using 3D HUVS can be performed safely by experienced surgeons.

Subfoveal Nodule Affecting Visual Prognosis in Coats Disease.

PURPOSE: To investigate the characteristics of subfoveal nodules in Korean patients with Coats disease and their association with visual outcomes. METHODS: A retrospective analysis was conducted within the medical records of patients with stage 2B or 3A1 Coats disease, including clinical features, imaging, presence of either a subfoveal nodule or macular fibrosis, and visual outcome. RESULTS: Twelve patients were present with stage 2B or 3A1 Coats disease, and nine patients (75%) presented with subfoveal nodule. Between the group without subfoveal nodule and the group with subfoveal nodule, there were no significant differences in age (mean, 14.0 ± 1.7 years vs. 27.7 ± 21.8 years; p = 0.482), sex (all men), stage of the disease (stage 2B: three patients vs. eight patients, p > 0.999; stage 3A1: none vs. one patient, p > 0.999), extension of retinal exudation (mean, 7.7 hours vs. 4.1 hours; p = 0.209) and peripheral telangiectasia (mean, 3.7 hours vs. 4.2 hours; p = 0.727), and follow-up duration (mean, 65.0 months vs. 46.1 months; p = 0.600). There were significantly more patients with severe visual loss (≤20 / 200) among the patients with subfoveal nodule (none vs. seven patients, p = 0.045), and the cause for severe visual loss was macular fibrosis in all cases. Macular fibrosis developed significantly more frequently in the patients with subfoveal nodule (none vs. seven = patients, p = 0.045). CONCLUSIONS: This study is the first study covering the analysis of subfoveal nodules in Korean patients with Coats disease. The existence of a subfoveal nodule at the initial diagnosis serves as an indicator predicting the development of macular fibrosis and a less favorable visual outcome in the patients with Coats disease. A multicenter study with a larger patient pool and further studies toward the therapeutic approach for the subfoveal nodule and macular fibrosis are needed.

Self-assembling biomolecules for biosensor applications.

Molecular self-assembly has received considerable attention in biomedical fields as a simple and effective method for developing biomolecular nanostructures. Self-assembled nanostructures can exhibit high binding affinity and selectivity by displaying multiple ligands/receptors on their surface. In addition, the use of supramolecular structure change upon binding is an intriguing approach to generate binding signal. Therefore, many self-assembled nanostructure-based biosensors have been developed over the past decades, using various biomolecules (e.g., peptides, DNA, RNA, lipids) and their combinations with non-biological substances. In this review, we provide an overview of recent developments in the design and fabrication of self-assembling biomolecules for biosensing. Furthermore, we discuss representative electrochemical biosensing platforms which convert the biochemical reactions of those biomolecules into electrical signals (e.g., voltage, ampere, potential difference, impedance) to contribute to detect targets. This paper also highlights the successful outcomes of self-assembling biomolecules in biosensor applications and discusses the challenges that this promising technology needs to overcome for more widespread use.

Patient-Centered Economic Burden of Exudative Age-Related Macular Degeneration: Retrospective Cohort Study.

BACKGROUND: Exudative age-related macular degeneration (AMD), one of the leading causes of blindness, requires expensive drugs such as anti-vascular endothelial growth factor (VEGF) agents. The long-term regular use of effective but expensive drugs causes an economic burden for patients with exudative AMD. However, there are no studies on the long-term patient-centered economic burden of exudative AMD after reimbursement of anti-VEGFs. OBJECTIVE: This study aimed to evaluate the patient-centered economic burden of exudative AMD for 2 years, including nonreimbursement and out-of-pocket costs, compared with nonexudative AMD using the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM). METHODS: This retrospective cohort study was conducted using the OMOP CDM, which included 2,006,478 patients who visited Seoul National University Bundang Hospital from June 2003 to July 2019. We defined the exudative AMD group as patients aged >50 years with a diagnosis of exudative AMD and a prescription for anti-VEGFs or verteporfin. The control group was defined as patients aged >50 years without a diagnosis of exudative AMD or a prescription for anti-VEGFs or verteporfin. To adjust for selection bias, controls were matched by propensity scores using regularized logistic regression with a Laplace prior. We measured any medical cost occurring in the hospital as the economic burden of exudative AMD during a 2-year follow-up period using 4 categories: total medical cost, reimbursement cost, nonreimbursement cost, and out-of-pocket cost. To estimate the average cost by adjusting the confounding variable and overcoming the positive skewness of costs, we used an exponential conditional model with a generalized linear model. RESULTS: We identified 931 patients with exudative AMD and matched 783 (84.1%) with 2918 patients with nonexudative AMD. In the exponential conditional model, the total medical, reimbursement, nonreimbursement, and out-of-pocket incremental costs were estimated at US $3426, US $3130, US $366, and US $561, respectively, in the first year and US $1829, US $1461, US $373, and US $507, respectively, in the second year. All incremental costs in the exudative AMD group were 1.89 to 4.25 and 3.50 to 5.09 times higher in the first and second year, respectively, than those in the control group (P<.001 in all cases). CONCLUSIONS: Exudative AMD had a significantly greater economic impact (P<.001) for 2 years on reimbursement, nonreimbursement, and out-of-pocket costs than nonexudative AMD after adjusting for baseline demographic and clinical characteristics using the OMOP CDM. Although economic policies could relieve the economic burden of patients with exudative AMD over time, the out-of-pocket cost of exudative AMD was still higher than that of nonexudative AMD for 2 years. Our findings support the need for expanding reimbursement strategies for patients with exudative AMD given the significant economic burden faced by patients with incurable and fatal diseases both in South Korea and worldwide.

Altered gut microbiome plays an important role in AKI to CKD transition in aged mice.

Introduction: This study investigated the role of renal-intestinal crosstalk in the transition from acute kidney injury (AKI) to chronic kidney disease (CKD) in elderly individuals. Methods: Using young and aged mice, we induced bilateral ischemia-reperfusion injury (IRI) and compared intestinal and kidney inflammation over 28 days. To determine the role of the microbiome in gut-kidney crosstalk, we analyzed the microbiome of fecal samples of the young vs. aged mice and examined the effects of probiotic supplementation. Results: In the post-IRI recovery phase, prolonged intestinal and renal inflammation along with dysbiosis were evident in aged vs. younger mice that was associated with severe renal dysfunction and fibrosis progression in aged mice. Probiotic supplementation with Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI alleviated intestinal inflammation but not intestinal leakage, characterized by decreased inflammatory cytokine levels and decreased infiltration of macrophages, neutrophils, and Th17 cells. This was associated with improved M1-dominant renal inflammation and ultimately improved renal function and fibrosis, suggesting that renal-intestinal crosstalk in aged mice contributes to the transition from AKI to CKD. Discussion: Our study findings suggest that exacerbation of chronic inflammation through the gut-kidney axis might be an important mechanism in the transition from AKI to CKD in the elderly.

Relationships Between Skeletal Muscle Mass, Lumbar Lordosis, and Chronic Low Back Pain in the Elderly.

OBJECTIVE: Loss of skeletal muscle mass is known to be associated with multiple morbidities. However, there is a dearth of reports on its association with lumbar lordosis and musculoskeletal pain. The aim of this study was to delineate the cross-sectional relationship between loss of skeletal muscle mass, lumbar lordosis, and chronic low back pain (CLBP). METHODS: A total of 721 medical records were reviewed, and data from 165 older subjects (over 65 years old; 81 men and 84 women) were retrospectively analyzed. Subjects were categorized into either the CLBP group (back pain for more than 6 months; 35 men and 36 women) or the control group (46 men and 48 women). The modified skeletal muscle mass index (MSMI, appendicular skeletal muscle mass [kg]/weight [kg] × 100), assessed by bioelectrical impedance analysis, and lumbar lordotic angle (LLA) were measured and compared between the CLBP group and the control group. The correlation between MSMI and LLA was investigated. RESULTS: The LLA of men and women in the CLBP group was significantly lower than that of the control group (p < 0.05). The MSMI was decreased in the CLBP group compared to the control group (p < 0.05). For both sexes, positive correlations were observed between the MSMI and LLA. CONCLUSION: A close cross-sectional relationship was observed between MSMI, LLA, and CLBP. This suggests a potential interaction between the reduction in skeletal muscle mass and altered lumbar spine sagittal alignment, which could lead to CLBP.

Structural Modeling of Cytokine-Receptor-JAK2 Signaling Complexes Using AlphaFold Multimer.

Homodimeric class 1 cytokine receptors include the erythropoietin (EPOR), thrombopoietin (TPOR), granulocyte colony-stimulating factor 3 (CSF3R), growth hormone (GHR), and prolactin receptors (PRLR). These cell-surface single-pass transmembrane (TM) glycoproteins regulate cell growth, proliferation, and differentiation and induce oncogenesis. An active TM signaling complex consists of a receptor homodimer, one or two ligands bound to the receptor extracellular domains, and two molecules of Janus Kinase 2 (JAK2) constitutively associated with the receptor intracellular domains. Although crystal structures of soluble extracellular domains with ligands have been obtained for all of the receptors except TPOR, little is known about the structure and dynamics of the complete TM complexes that activate the downstream JAK-STAT signaling pathway. Three-dimensional models of five human receptor complexes with cytokines and JAK2 were generated here by using AlphaFold Multimer. Given the large size of the complexes (from 3220 to 4074 residues), the modeling required a stepwise assembly from smaller parts, with selection and validation of the models through comparisons with published experimental data. The modeling of active and inactive complexes supports a general activation mechanism that involves ligand binding to a monomeric receptor followed by receptor dimerization and rotational movement of the receptor TM α-helices, causing proximity, dimerization, and activation of associated JAK2 subunits. The binding mode of two eltrombopag molecules to the TM α-helices of the active TPOR dimer was proposed. The models also help elucidate the molecular basis of oncogenic mutations that may involve a noncanonical activation route. Models equilibrated in explicit lipids of the plasma membrane are publicly available.