Energy landscape analysis and time-series clustering analysis of patient state multistability related to rheumatoid arthritis drug treatment: The KURAMA cohort study.

Rheumatoid arthritis causes joint inflammation due to immune abnormalities, resulting in joint pain and swelling. In recent years, there have been considerable advancements in the treatment of this disease. However, only approximately 60% of patients achieve remission. Patients with multifactorial diseases shift between states from day to day. Patients may remain in a good or poor state with few or no transitions, or they may switch between states frequently. The visualization of time-dependent state transitions, based on the evaluation axis of stable/unstable states, may provide useful information for achieving rheumatoid arthritis treatment goals. Energy landscape analysis can be used to quantitatively determine the stability/instability of each state in terms of energy. Time-series clustering is another method used to classify transitions into different groups to identify potential patterns within a time-series dataset. The objective of this study was to utilize energy landscape analysis and time-series clustering to evaluate multidimensional time-series data in terms of multistability. We profiled each patient's state transitions during treatment using energy landscape analysis and time-series clustering. Energy landscape analysis divided state transitions into two patterns: "good stability leading to remission" and "poor stability leading to treatment dead-end." The number of patients whose disease status improved increased markedly until approximately 6 months after treatment initiation and then plateaued after 1 year. Time-series clustering grouped patients into three clusters: "toward good stability," "toward poor stability," and "unstable." Patients in the "unstable" cluster are considered to have clinical courses that are difficult to predict; therefore, these patients should be treated with more care. Early disease detection and treatment initiation are important. The evaluation of state multistability enables us to understand a patient's current state in the context of overall state transitions related to rheumatoid arthritis drug treatment and to predict future state transitions.

Active Rheumatoid Arthritis and Scoliosis: A Mid-Term Cohort Study.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To elucidate the factors related to progression of scoliosis in patients with rheumatoid arthritis (RA) using longitudinal cohort data. SUMMARY OF BACKGROUND DATA: Thirty percent of patients with RA have lumbar scoliosis. However, the effectiveness of current treatment methods in preventing the progression of scoliosis is not well-understood due to a lack of longitudinal studies. METHODS: We enrolled 180 patients with RA who were followed up for over two years, all of whom underwent standing spinal X-rays. These patients were categorized based on their disease activity score-28 with erythrocyte sedimentation rate (DAS28-ESR) into two groups: those in remission (n=76) and those in non-remission (n=104). We evaluated various radiographic measures, including C7 center sacral vertical line (C7-CSVL), pelvic obliquity, major Cobb angle, and curve location. RESULTS: Fifty-three (29.4%) patients presented progression of scoliosis during a mean follow-up period of 4.8 years. Patients in the non-remission showed larger Cobb angle at baseline and final follow-up, compared to those in remission. The annual progression rate of the curve was also greater in the non-remission group (1.04 degree /year), than in the remission group (0.59 degree /year, P=0.001). There was no difference in the incidence of new vertebral fractures. The presence of a baseline cobb angle of 10 degree or more (OR: 3.14; 95% CI: 1.38-7.13; P=0.006), glucocorticoid use (OR: 2.88; 95% CI: 1.18-7.06; P=0.021), and non-remission at baseline (OR: 2.83; 95% CI: 1.25-6.41; P=0.012) were significant risk factors for progression of scoliosis. CONCLUSION: RA disease activity is linked to progression of scoliosis in patients with RA. Patients with RA who present with an initial scoliosis of 10 degrees or greater, require glucocorticoids for treatment and are in non-remission at baseline may be at high risk for scoliosis progression.

Safety of Janus kinase inhibitors compared to biological DMARDs in patients with rheumatoid arthritis and renal impairment: the ANSWER cohort study.

Data on the safety of Janus kinase inhibitors (JAKis) in patients with renal impairment are lacking. This study aimed to investigate the safety of JAKis compared to biological (b) DMARDs in patients with rheumatoid arthritis (RA) and renal impairment. We used a multi-centre observational registry of patients with RA in Japan (the ANSWER cohort). We assessed the drug retention rates of b/targeted synthetic DMARDs with different modes of action (tumour necrosis factor inhibitors (TNFis), immunoglobulins fused with cytotoxic T-lymphocyte antigen (CTLA-4-Ig), interleukin-6 receptor inhibitors (IL-6Ris), and JAKis) in patients with RA stratified by pre-treatment estimated glomerular filtration rate (eGFR) levels. The time to discontinuation of bDMARDs or JAKis was analysed using a multivariate Cox proportional hazards model This study included 3775 patients, who were classified into three groups (the normal group (eGFR ≥ 60 mL/min/1.73 m2): 2893 patients; CKDa group (eGFR 45-60 mL/min/1.73 m2): 551; and CKDb group (eGFR < 45 mL/min/1.73 m2): 331). In the CKDb group, the 12-month drug retention rate due to adverse events (AE) was the lowest in patients treated with JAKi (TNFi: 93.1%; IL-6Ri: 94.1%; CTLA-4-Ig: 92.3%; JAKi: 75.1%). In the normal and CKDa groups, drug retention rates due to AE were similar among patients treated with bDMARDs and JAKi. In contrast, drug retention rates due to inefficacy were similar between bDMARDs and JAKis in all groups. In the Cox-proportional model, in the CKDb group, TNFi, IL-6Ri, and CTLA-4-Ig showed lower incidence of drug discontinuation due to AE than JAKis (TNFi: hazard ratio = 0.23 (95% confidence interval 0.09-0.61), IL-6Ri: 0.34 (0.14-0.81), CTLA-4-Ig: 0.36 (0.15-0.89)). JAKis showed the lowest drug retention due to AE in patients with moderate-to-severe and severe renal impairment (eGFR < 45 mL/min/1.73 m2). Physicians should pay more attention to renal function when using JAKis than when using bDMARDs.

Low Hounsfield unit values on computed tomography as a potential predictor of vertebral fracture in patients with rheumatoid arthritis: The KURAMA cohort study.

OBJECTIVE: Hounsfield units (HU) measured using computed tomography (CT) have gained considerable attention for the detection of osteoporosis. This study aimed to investigate whether opportunistic CT could predict vertebral fractures in patients with rheumatoid arthritis (RA). METHODS: A total of 233 patients with RA who underwent chest CT were included in this study. The HU values of the anterior 1/3 of the vertebral bodies based on the sagittal plane at T11-L2 after reconstruction were measured. The incidence of vertebral fractures was investigated with respect to the HU value. RESULTS: Vertebral fractures were identified in 32 patients during a mean follow-up period of 3.8 years. In patients who experienced vertebral fractures within 2 years of CT imaging, the HU values of the vertebral bodies (T11-L2) were lower than those in patients who did not experience fractures. Receiver operating characteristic curve analysis identified that a T11 HU value of <125 was a risk factor for vertebral fracture within 2 years. Multivariate analysis showed that a T11 HU value of <125 and the existence of prevalent vertebral fractures were significant risk factors for fracture. CONCLUSION: HU measurements of the anterior 1/3 of the vertebral body are a potential predictor for vertebral fractures in patients with RA.

Effect of high disease activity on spinal sagittal malalignment in patients with rheumatoid arthritis.

OBJECTIVE: Atlantoaxial subluxation is a well-known serious complication encountered in patients with rheumatoid arthritis (RA). However, it is unknown whether RA affects global spinal alignment. The aim of this study was to investigate whether high disease activity in patients with RA exacerbates spinal sagittal malalignment. METHODS: The authors included 197 patients with RA who were followed up for > 2 years; standing spinal radiographs were obtained in all patients. Patients were divided into persistent moderate disease activity/high disease activity (pMDA/HDA; n = 64) and non-pMDA/HDA (n = 133) groups based on the disease activity at follow-up visits. Radiographic parameters assessed included pelvic incidence, pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7 sagittal vertical axis (SVA). RESULTS: Over an average 5-year follow-up, increases in SVA, PT, and TK and a decrease in LL were observed. The pMDA/HDA group had a larger increase in PT and a higher incidence of vertebral fractures than the non-pMDA/HDA group. After adjusting variables using propensity score matching, the authors still found a higher rate of increase in PT (0.79°/year vs 0.01°/year, p = 0.001) in the pMDA/HDA group than in the non-pMDA/HDA group. This trend remained consistent even when patients who developed vertebral fractures were excluded. CONCLUSIONS: Spinal sagittal alignment deteriorates over time in patients with RA. High disease activity in RA exacerbates spinal deformity.

Comparison of safety and effectiveness between etanercept biosimilar LBEC0101 and reference in patients with rheumatoid arthritis in real-world data using the KURAMA cohort.

OBJECTIVES: Biosimilars are anticipated to be widely used in the treatment of rheumatoid arthritis (RA), owing to their cost efficiency; LBEC0101 was the first etanercept (ETN) biosimilar approved in Japan. However, there are limited real-world data comparing its safety and effectiveness with those of a reference product. METHODS: This study used data from the Kyoto University Rheumatoid Arthritis Management Alliance cohort, including patients with RA who received ETN therapy-ETN reference product (ETN-RP) or LBEC0101-between 2015 and 2021. Serum ETN levels were measured using liquid chromatography-tandem mass spectrometry. RESULTS: The 1-year continuation rates of ETN-RP and LBEC0101 were 58.7% and 74.4%, respectively. Effectiveness of treatment was evaluated in 18 patients; both products significantly reduced the 28-joint RA disease activity score and erythrocyte sedimentation rate (DAS28-ESR). Moreover, to determine equivalence, we analysed 11 patients who switched from ETN-RP to LBEC0101; the DAS28-ESR and serum ETN levels before and after switching were not significantly different. CONCLUSIONS: This real-world cohort study confirmed that the biosimilar of ETN, LBEC0101, was comparable to the reference product in terms of continuation rate, effectiveness at initiation of introduction, and effect persistence before and after switching in clinical practice.

Impact of Concurrent Visual and Hearing Impairment on Incident Alzheimer's Disease: The LIFE Study.

Background: The prevalence of Alzheimer's disease (AD) is increasing in Japan due to population aging. The association between sensory impairment and incident AD remains unclear. Objective: This study aimed to investigate the impact of sensory impairment on incident AD. Methods: We analyzed residents of five municipalities participating in the Longevity Improvement & Fair Evidence (LIFE) Study. The participants comprised individuals who had newly applied for long-term care needs certification between 2017 and 2022 and had no cognitive impairment upon application or AD diagnosis within the preceding six months. Participants were classified according to sensory impairment status: visual impairment (VI), hearing impairment (HI), neither sensory impairment (NSI), and dual sensory impairment (DSI). The month succeeding the certification application was set as the index month, and the interval from that month until AD onset was assessed. Multivariable Cox proportional hazards analysis was performed to calculate the risk of AD onset according to sensory impairment status while adjusting for sex, age, dependence level, self-reliance level, and comorbidities. Results: Among 14,186 participants, we identified 1,194 (8.4%) who developed AD over a median follow-up period of 22.6 months. VI and HI only were not associated with incident AD. However, DSI conferred a significantly higher risk (HR: 1.6, CI: 1.1-2.2, p = 0.008) of AD onset than NSI. Conclusions: Individuals with concurrent DSI have a higher risk of developing AD than those with single or NSI. Preventing and treating sensory impairment may not only improve functional outcomes, but could also help to reduce the future risk of AD.

Monocyte-derived transcriptomes explain the ineffectiveness of abatacept in rheumatoid arthritis.

BACKGROUND: The biological mechanisms underlying the differential response to abatacept in patients with rheumatoid arthritis (RA) are unknown. Here, we aimed to identify cellular, transcriptomic, and proteomic features that predict resistance to abatacept in patients with RA. METHODS: Blood samples were collected from 22 RA patients treated with abatacept at baseline and after 3 months of treatment. Response to treatment was defined by the European League Against Rheumatism (EULAR) response criteria at 3 months, and seven patients were classified as responders and the others as non-responders. We quantified gene expression levels by RNA sequencing, 67 plasma protein levels, and the expression of surface molecules (CD3, 19, and 56) by flow cytometry. In addition, three gene expression data sets, comprising a total of 27 responders and 50 non-responders, were used to replicate the results. RESULTS: Among the clinical characteristics, the number of monocytes was significantly higher in the non-responders before treatment. Cell type enrichment analysis showed that differentially expressed genes (DEGs) between responders and non-responders were enriched in monocytes. Gene set enrichment analysis, together with single-cell analysis and deconvolution analysis, identified that Toll-like receptor 5 (TLR5) and interleukin-17 receptor A (IL17RA) pathway in monocytes was upregulated in non-responders. Hepatocyte growth factor (HGF) correlated with this signature showed higher concentrations in non-responders before treatment. The DEGs in the replication set were also enriched for the genes expressed in monocytes, not for the TLR5 and IL17RA pathway but for the oxidative phosphorylation (OXPHOS) pathway. CONCLUSIONS: Monocyte-derived transcriptomic features before treatment underlie the differences in abatacept efficacy in patients with RA. The pathway activated in monocytes was the TLR5 and IL17RA-HGF signature in the current study, while it was the OXPHOS pathway in the replication set. Elevated levels of HGF before treatment may serve as a potential biomarker for predicting poor responses to abatacept. These findings provide insights into the biological mechanisms of abatacept resistance, contributing valuable evidence for stratifying patients with RA.

Management and treatment outcomes of rheumatoid arthritis in the era of biologic and targeted synthetic therapies: evaluation of 10-year data from the KURAMA cohort.

BACKGROUND: Advances in rheumatoid arthritis (RA) treatment, highlighted by biological disease-modifying antirheumatic drugs (bDMARDs) and targeted synthetic DMARDs (tsDMARDs), have altered the paradigm of RA treatment in the last decade. Therefore, real-world clinical evidence is needed to understand how treatment strategies and outcomes have changed. METHODS: Using an observational cohort of RA from 2012 to 2021, we collected cross-sectional data of RA patients annually to analyze a trend in RA management. For patients who initiated b/tsDMRDs, we evaluated treatment outcomes between b/tsDMARDs. Mixed-effect models were applied to examine the statistical implications of changes over time in treatment outcomes with a background adjustment. RESULTS: We analyzed annual cross-sectional data from 5070 patients and longitudinal data from 1816 patients in whom b/tsDMARDs were initiated between 2012 and 2021. b/tsDMARD use increased, whereas glucocorticoid use decreased from 2012 to 2021. Disease activity and functional disability measures improved over time. The percentage of tsDMARD prescriptions considerably increased. All b/tsDMARDs showed clinical improvements in disease activity and functional disability. Statistically, TNFi showed better short-term improvements in b/tsDMARD-naïve patients, while IL6Ri demonstrated significant long-term benefits. IL6Ri had better retention rates in switched patients. After adjustment for patient characteristics, the annual change of RA disease activity and functional disability fared significantly better from 2012 to 2021. CONCLUSIONS: With the development of new RA therapeutics, overall treatment outcomes advanced in the past decade.

Predictive value of baseline concomitant glucocorticoid for abatacept-mediated long-term inhibition of radiographic progression: insights from the KURAMA cohort.

Abatacept (ABT) is a biological disease-modifying antirheumatic drug (bDMARDs) for rheumatoid arthritis (RA) when conventional synthetic DMARDs are ineffective. We aimed to evaluate the long-term effects of ABT on joint destruction in patients treated for over 2 years. Radiographic progression was evaluated using the van der Heijde-modified Total Sharp Score (mTSS) by two rheumatologists at ABT initiation and after 2 years. Multivariate logistic regression analysis was used to identify factors associated with structural remission, defined as the mean annual change in mTSS ≤0.5. Among the 111 patients included, 48 discontinued, and 63 continued ABT treatment until radiographic evaluation was performed. The rate of patients who achieved estimated TSS REM (yearly progression of van der Heijde modified total Sharp scores ≤0.5) was significantly lower in ABT-dropouts than in the ABT-continued group (69% vs. 48%, p = .0336 by Fisher's exact test). Among the continued ABT cases, concomitant glucocorticoid treatment at ABT initiation was the strongest negative predictive factor of estimated TSS REM in univariate and multivariate logistic regression analyses. Radiographic progression after ABT administration should be evaluated separately for dropout and non-dropout cases. Glucocorticoids at the initiation of ABT may serve as a predictive factor for joint destruction in long-term ABT use.

Real-world comparative study of the efficacy of Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVE: This multicentre, retrospective study compared the efficacy and safety of tofacitinib, baricitinib, peficitinib and upadacitinib in real-world clinical settings after minimizing selection bias and adjusting the confounding patient characteristics. METHOD: The 622 patients were selected from the ANSWER cohort database and treated with tofacitinib (TOF), baricitinib (BAR), peficitinib (PEF) or upadacitinib (UPA). The patient's background was matched using propensity score-based inverse probability of treatment weighting (IPTW) among four treatment groups. The values of Clinical Disease Activity Index (CDAI), C-reactive protein (CRP), and modified Health Assessment Questionnaire (mHAQ) after drug initiation and the remission or low disease activity (LDA) rates of CDAI at 6 months after drug initiation were compared among the four groups. Further, the predictive factor for TOF and BAR efficacy was analysed. RESULTS: The retention and discontinuation rates until 6 months after drug initiations were not significantly different among the four JAK inhibitors treatment groups. Mean CDAI value, CDAI remission rate, and CDAI-LDA rate at 6 months after drug initiation were not significantly different among treatment groups. Baseline CDAI (TOFA: OR 1.09, P < 0.001; BARI: OR 1.07, P < 0.001), baseline CRP (TOFA: OR 1.32, P = 0.049), baseline glucocorticoid dose (BARI: OR 1.18, 95% CI 1.01-1.38, P = 0.035), a number of previous biological or targeted synthetic disease-modifying antirheumatic drugs (biological/targeted synthetic DMARDs) (BARI: OR 1.36, P = 0.004) were predictive factors for resistance to CDAI-LDA achievement to JAK inhibitor treatment. CONCLUSION: The efficacy and safety of TOF, BAR, PEF and UPA were not significantly different for the treatment of patients with rheumatoid arthritis.

How do symptoms of each joint contribute to global pain, disease activity and functional disability in rheumatoid arthritis?-A comprehensive association study using a large cohort.

BACKGROUND: Established assessment tools for patients with rheumatoid arthritis (RA), including disease activity scores (DASs), disease activity indexes (DAIs), visual analog scales (VASs), and health assessment questionnaires (HAQs), are widely used. However, comparative associations between joint involvement and disease status assessment tools have rarely been investigated. METHODS: We included a dataset of 4016 patients from a large RA cohort from 2012 to 2019. The tenderness and swelling of each joint were counted as a symptom, with 70 and 68 affected joints throughout the body, respectively. The relative contribution of various joints to the disease status assessment tools, VAS scores, and functional disability indexes was analyzed using multiple regression analysis. RESULTS: The wrist showed the most significant contribution overall, especially in DASs and VASs, while the metacarpophalangeal and proximal interphalangeal joints made significant contributions to DASs and DAIs, but not to VASs and HAQs. The shoulder and the elbow significantly contributed to HAQs, but only the shoulder did to the VASs. The knee universally contributed to all of the tools, but the ankle played a minor but important role in most assessment tools, especially in HAQs. Similar but different contribution ratios were found between the sets of DASs, DAIs, VASs, or HAQs. CONCLUSIONS: Each joint makes a unique contribution to these assessment tools. The improvement or aggravation of symptoms in each joint affects the assessment tools in different manners.

Serum Concentrations of Infliximab and IL-6 for Predicting One-Year Discontinuation of Infliximab Treatment Owing to Secondary Non-response in Patients with Rheumatoid Arthritis.

Secondary non-response to infliximab (IFX) occurs in some patients with rheumatoid arthritis (RA). Although therapeutic drug monitoring (TDM) is a useful tool to optimize IFX therapy, it is unclear whether it can help to identify the risk of secondary non-response. This study aimed to explore the utility of serum levels of IFX or other biomarkers to predict IFX discontinuation owing to secondary non-response. A single-center, retrospective study was conducted using the Kyoto University Rheumatoid Arthritis Management Alliance cohort database between 2011 and 2020. Serum IFX levels were measured using liquid chromatography-tandem mass spectrometry. An electrochemiluminescence assay was used to quantify serum levels of tumor necrosis factor-α and interleukin-6 and detect anti-drug antibodies. Eighty-four out of 310 patients were eligible for this study. The cutoff levels of biomarkers were determined by receiver operating characteristic analysis. IFX persistence was similar between groups stratified using IFX levels, tumor necrosis factor-α levels, interleukin-6 levels, and anti-drug antibodies positivity. The group with lower IFX and higher interleukin-6 levels had the worst therapy persistence (p = 0.017) and the most frequent disease worsening (90.0%, p < 0.001). Evaluating both interleukin-6 and IFX levels, not just IFX alone, enabled us to identify patients at risk of discontinuing IFX treatment. These findings support the utility of measuring IFX and interleukin-6 levels for successful maintenance therapy for RA.

Drug retention of biologics and Janus kinase inhibitors in patients with rheumatoid arthritis: the ANSWER cohort study.

OBJECTIVES: This multicentre retrospective study in Japan aimed to assess the retention of biological disease-modifying antirheumatic drugs and Janus kinase inhibitors (JAKi), and to clarify the factors affecting their retention in a real-world cohort of patients with rheumatoid arthritis. METHODS: The study included 6666 treatment courses (bDMARD-naïve or JAKi-naïve cases, 55.4%; tumour necrosis factor inhibitors (TNFi) = 3577; anti-interleukin-6 receptor antibodies (aIL-6R) = 1497; cytotoxic T lymphocyte-associated antigen-4-Ig (CTLA4-Ig) = 1139; JAKi=453 cases). The reasons for discontinuation were divided into four categories (ineffectiveness, toxic adverse events, non-toxic reasons and remission); multivariate Cox proportional hazards modelling by potential confounders was used to analyse the HRs of treatment discontinuation. RESULTS: TNFi (HR=1.93, 95% CI: 1.69 to 2.19), CTLA4-Ig (HR=1.42, 95% CI: 1.20 to 1.67) and JAKi (HR=1.29, 95% CI: 1.03 to 1.63) showed a higher discontinuation rate due to ineffectiveness than aIL-6R. TNFi (HR=1.28, 95% CI: 1.05 to 1.56) and aIL-6R (HR=1.27, 95% CI: 1.03 to 1.57) showed a higher discontinuation rate due to toxic adverse events than CTLA4-Ig. Concomitant use of oral glucocorticoids (GCs) at baseline was associated with higher discontinuation rate due to ineffectiveness in TNFi (HR=1.24, 95% CI: 1.09 to 1.41), as well as toxic adverse events in JAKi (HR=2.30, 95% CI: 1.23 to 4.28) and TNFi (HR=1.29, 95%CI: 1.07 to 1.55). CONCLUSIONS: TNFi (HR=1.52, 95% CI: 1.37 to 1.68) and CTLA4-Ig (HR=1.14, 95% CI: 1.00 to 1.30) showed a higher overall drug discontinuation rate, excluding non-toxicity and remission, than aIL-6R.

Caution to Poor Adherence With Immunosuppressant Medication That Causes Coma-Onset Autoimmune Encephalitis: A Case Report and Literature Review.

Autoimmune encephalitis after liver transplantation (LT) is a rare disorder. This is because patients are usually in an immunosuppressed state after LT. Here, we report a rare case of autoantibody-negative autoimmune-encephalitis-induced coma after living-donor (LD) LT. A 45-year-old woman who underwent LDLT for primary biliary cholangitis (PBC) was brought to our hospital with the chief complaint of cognitive deficiency and an episode of memory loss. Physical examination, laboratory tests, and cerebrospinal fluid analysis revealed no significant findings. However, diffusion-weighted magnetic resonance imaging showed hyperintensity in the bilateral hippocampus. No autoantibodies associated with autoimmune encephalitis were detected. The diagnosis of antibody-negative autoimmune encephalitis was made on the basis of low immunosuppressive drug levels in the blood (indicative of poor adherence) and the presence of PBC as the autoimmune disease. The patient regained consciousness after intravenous methylprednisolone pulse therapy and plasma exchange. This case highlights that when examining patients with impaired consciousness after LDLT, it is important to consider autoimmune encephalitis as a potential diagnosis.

Predicting dry weight change in Hemodialysis patients using machine learning.

BACKGROUND: Machine Learning has been increasingly used in the medical field, including managing patients undergoing hemodialysis. The random forest classifier is a Machine Learning method that can generate high accuracy and interpretability in the data analysis of various diseases. We attempted to apply Machine Learning to adjust dry weight, the appropriate volume status of patients undergoing hemodialysis, which requires a complex decision-making process considering multiple indicators and the patient's physical conditions. METHODS: All medical data and 69,375 dialysis records of 314 Asian patients undergoing hemodialysis at a single dialysis center in Japan between July 2018 and April 2020 were collected from the electronic medical record system. Using the random forest classifier, we developed models to predict the probabilities of adjusting the dry weight at each dialysis session. RESULTS: The areas under the receiver-operating-characteristic curves of the models for adjusting the dry weight upward and downward were 0.70 and 0.74, respectively. The average probability of upward adjustment of the dry weight had sharp a peak around the actual change over time, while the average probability of downward adjustment of the dry weight formed a gradual peak. Feature importance analysis revealed that median blood pressure decline was a strong predictor for adjusting the dry weight upward. In contrast, elevated serum levels of C-reactive protein and hypoalbuminemia were important indicators for adjusting the dry weight downward. CONCLUSIONS: The random forest classifier should provide a helpful guide to predict the optimal changes to the dry weight with relative accuracy and may be useful in clinical practice.

Load distribution structure of rear bumper beam to enhance vehicle body energy absorption in rear-end collisions.

OBJECTIVE: This research focused on FMVSS301, which is required for higher energy absorption as a regulation for rear-end collisions. Since they are offset collisions, the deformation of the non-collision side frame, which does not directly contact the barrier, is less than on the collision side. The reason is that the rear bumper beam with curvature is deformed into a straight shape by the load from the barrier, resulting in an asymmetrical load distribution from the barrier that is biased toward the collision side. Therefore, the objective of this research was to construct a new bumper beam structure that reduces the difference in the load input to both frames and increases the energy absorption of the non-collision side frame. METHOD: The basic principle is to generate a counterforce against the lateral loads during transmitting the load from barrier to the frames. To achieve this, a bow-shaped rear bumper beam structure was devised. The rear bumper beam corresponds to the bow and the newly added connection plate to the string. The lateral load increase is suppressed and load distribution to the rear frame is maintained. RESULTS: The designed rear bumper beam and rear components equipped with the rear bumper beam were both prepared and evaluated by drop test. With testing of the rear bumper beam, it was demonstrated that the load in the lateral direction, which conventionally generates over 80 kN, could be canceled. Tests of the rear component demonstrated that load distribution to the rear frame could be maintained, and the energy absorption of the non-collision side frame could be enhanced by 35 times. The total energy absorption of the barrier and the two frames was demonstrated to increase 2.9 times. CONCLUSION: The bow-shaped rear bumper beam was designed to distribute the load evenly to the collision and non-collision side frames, and to deform both frames, thereby achieving a higher energy absorption of the entire vehicle body. This is expected to be applicable to electric vehicles and FCVs, which require more energy absorption with increased vehicle weight.

New load transfer structure to reduce body deformation in side collisions.

OBJECTIVE: In this research, body technology was established for side collisions with new IIHS MDB as a representative case. In the conventional body structure, most of the load received from the barrier is absorbed by bending deformation of the door beam and B-pillar, etc. For that reason, the body is subjected to large deformation before reaching the maximum load, and the deformation increases further when subjected to a high-energy collision. Therefore, the objective of this research is to create a structure that increases the load from the initiation of impact and suppresses the deformation of the car body. METHOD: An arched door beam was developed to reduce the bending moment by the axial load in the longitudinal direction generated during the deformation and to increase the load in the lateral direction. A principle equation was developed that uses the shape of the door beam as a variable. A prototype of the arched door beam was fabricated, and its performance was evaluated by an impactor test. A full-car simulation was conducted using a mass-produced sedan as a base, to which the arched door beam was added to verify the performance of the complete vehicle. RESULTS: The results of the impactor tests were evaluated using the load gradient, which was defined as the generated load divided by the amount of deformation. Compared to conventional straight door beams, the load gradient was 7.1 times higher. Full-car simulation results showed that for a gasoline-powered vehicle body weight, the body load gradient of the proposed structure was 4.7 times higher, and the body deformation adjacent to the dummy shoulder was reduced by 210 mm. Spine acceleration of the dummy was reduced by 56%. CONCLUSION: The body structure proposed in this research has the effect of increasing the load gradient and reducing body deformation and spine acceleration. It is expected to be applicable to EVs and FCVs, which require more energy absorption due to their increased vehicle weight.

Genetic and histopathological analysis of spermatogenesis after short-term testicular torsion in rats.

BACKGROUND: Patients with testicular torsion (TT) may exhibit impaired spermatogenesis from reperfusion injury after detorsion surgery. Alteration in the expressions of spermatogenesis-related genes induced by TT have not been fully elucidated. METHODS: Eight-week-old Sprague-Dawley rats were grouped as follows: group 1 (sham-operated), group 2 (TT without reperfusion) and group 3 (TT with reperfusion). TT was induced by rotating the left testis 720° for 1 h. Testicular reperfusion proceeded for 24 h. Histopathological examination, oxidative stress biomarker measurements, RNA sequencing and RT-PCR were performed. RESULTS: Testicular ischemia/reperfusion injury induced marked histopathological changes. Germ cell apoptosis was significantly increased in group 3 compared with group 1 and 2 (mean apoptotic index: 26.22 vs. 0.64 and 0.56; p = 0.024, and p = 0.024, respectively). Johnsen score in group 3 was smaller than that in group 1 and 2 (mean: 8.81 vs 9.45 and 9.47 points/tubule; p = 0.001, p < 0.001, respectively). Testicular ischemia/reperfusion injury significantly upregulated the expression of genes associated with apoptosis and antioxidant enzymes and significantly downregulated the expression of genes associated with spermatogenesis. CONCLUSION: One hour of TT followed by reperfusion injury caused histopathological testicular damage. The relatively high Johnsen score indicated spermatogenesis was maintained. Genes associated with spermatogenesis were downregulated in the TT rat model. IMPACT: How ischemia/reperfusion injury in testicular torsion (TT) affects the expressions of genes associated with spermatogenesis has not been fully elucidated. This is the first study to report comprehensive gene expression profiles using next generation sequencing for an animal model of TT. Our results revealed that ischemia/reperfusion injury downregulated the expression of genes associated with spermatogenesis and sperm function in addition to histopathological damage, even though the duration of ischemia was short.