Characteristics of Acute Cartilage Response After Mechanical Loading in Patients with Early-Mild Knee Osteoarthritis

This study determined whether the acute cartilage response, assessed by cartilage thickness and echo intensity, differs between patients with early-mild knee osteoarthritis (OA) and healthy controls. We recruited 56 women aged ≥ 50 years with Kellgren-Lawrence (KL) grade ≤ 2 (age, 70.6 ± 7.4 years; height, 153.7 ± 5.2 cm; weight, 51.9 ± 8.2 kg). Based on KL grades and knee symptoms, the participants were classified into control (KL ≤ 1, asymptomatic, n = 27) and early-mild knee OA groups (KL 1 and symptomatic, KL 2, n = 29). Medial femoral cartilage thickness and echo intensity were assessed using ultrasonographic B-mode images before and after treadmill walking (15 min, 3.3 km/h). To investigate the acute cartilage response, repeated-measures analysis of covariance (groups × time) with adjusted age, external knee moment impulse, steps during treadmill walking, and cartilage thickness at pre-walking was performed. A significant interaction was found at the tibiofemoral joint; after walking, the cartilage thickness was significantly decreased in the early-mild knee OA group compared to the control group (p = 0.002). At the patellofemoral joint, a significant main effect of time was observed, but no interaction was detected (p = 0.802). No changes in cartilage echo intensity at either the tibiofemoral or patellofemoral joints, and no interactions were noted (p = 0.295 and p = 0.063). As acute cartilage response after walking, the thickness of the medial tibiofemoral joint in the early-mild knee OA was significantly reduced than that in the control group. Thus, greater acute deformation after walking might be a feature found in patients with early-mild knee OA.

Reliability and validity of quantitative ultrasound for evaluating patellar alignment: A pilot study

BACKGROUND

Patellar malalignment is a risk factor of patellofemoral pain. Evaluation of the patellar alignment have mostly used magnetic resonance imaging (MRI). Ultrasound (US) is a non-invasive instrument that can quickly evaluate patellar alignment. However, the method for evaluating patellar alignment via US has not been established. This study aimed to investigate the reliability and validity of evaluating patellar alignment via US.

METHODS

The sixteen right knees were imaged via US and MRI. US images were obtained at two sites of the knee to measure US-tilt as the index of patellar tilt. Using a single US image, we measured US-lateral distance and US-angle as the index of patellar shift. All US images were obtained three times each by two observers to evaluate reliabilities. Lateral patellar angle (LPA), as the indicators of patellar tilt, and lateral patella distance (LPD) and bisect offset (BO), as the indicators of patellar shift, were measured via MRI.

RESULTS

US measurements provided high intra- (within-day and between days) and interobserver reliabilities with exception of interobserver reliability of US-lateral distance. Pearson correlation coefficient indicated that US-tilt is significantly positively correlated with LPA (r = 0.79), and US-angle is significantly positively correlated with LPD (r = 0.71) and BO (r = 0.63).

CONCLUSION

Evaluating patellar alignment via US showed high reliabilities. US-tilt and US-angle showed moderate to strong correlation with MRI indices of patellar tilt and shift via MRI, respectively. US methods are useful for evaluating accurate and objective indices of patellar alignment.

Examination of knee extensor and valgus moment arms of the patellar tendon in older individuals with and without knee osteoarthritis

BACKGROUND

Joint moment arm is a major element that determines joint torque. This study aimed to investigate factors associated with knee extensor and valgus moment arms of the patellar tendon in older individuals with and without knee osteoarthritis.

METHODS

Thirty-six participants with knee osteoarthritis (mean age, 78.1 ± 6.0 years) and 43 healthy controls (mean age, 73.0 ± 6.3 years) were analyzed. Magnetic resonance images (MRI) from the knee joint and thigh were acquired using a 3.0 T MRI scanner. The three-dimensional moment arm was defined as the distance between the contact point of the tibiofemoral joint and the patellar tendon line. The three-dimensional moment arm was decomposed into sagittal and coronal components, which were calculated as knee extensor and valgus moment arms, respectively. Quadriceps muscle volume, epicondylar width, bisect offset, Insall-Salvati ratio, and Kellgren-Lawrence grade were assessed. Multiple regression analyses were performed in the healthy control and knee osteoarthritis groups, with knee extensor and valgus moment arms as dependent variables.

FINDINGS

Knee extensor moment arm was significantly associated with epicondylar width and the Insall-Salvati ratio in the healthy control group and with Kellgren-Lawrence grade, epicondylar width, and quadriceps muscle volume in the knee osteoarthritis group. Valgus knee moment arm was significantly associated with bisect offset in both the groups.

INTERPRETATION

Knee size, osteoarthritis severity, and quadriceps muscle volume affect the knee extensor moment arm in knee osteoarthritis, whereas lateral patellar displacement affects the valgus knee moment arms in older individuals with and without knee osteoarthritis.

Understanding muscle coordination during gait based on muscle synergy and its association with symptoms in patients with knee osteoarthritis

OBJECTIVE

We aimed to investigate the muscle coordination differences between a control group and patients with mild and severe knee osteoarthritis (KOA) using muscle synergy analysis and determine whether muscle coordination was associated with symptoms of KOA.

METHOD

Fifty-three women with medial KOA and 19 control patients participated in the study. The gait analyses and muscle activity measurements of seven lower limb muscles were assessed using a motion capture system and electromyography. Gait speed and knee adduction moment impulse were calculated. The spatiotemporal components of muscle synergy were extracted using non-negative matrix factorization, and the dynamic motor control index during walking (walk-DMC) was computed. The number of muscle synergy and their spatiotemporal components were compared among the mild KOA, severe KOA, and control groups. Moreover, the association between KOA symptoms with walk-DMC and other gait parameters was evaluated using multi-linear regression analysis.

RESULTS

The number of muscle synergies was lower in mild and severe KOA compared with those in the control group. In synergy 1, the weightings of biceps femoris and gluteus medius in severe KOA were higher than that in the control group. In synergy 3, the weightings of higher tibial anterior and lower gastrocnemius lateralis were confirmed in the mild KOA group. Regression analysis showed that the walk-DMC was independently associated with knee-related symptoms of KOA after adjusting for the covariates.

CONCLUSIONS

Muscle coordination was altered in patients with KOA. The correlation between muscle coordination and KOA may be attributed to the knee-related symptoms. Key points • Patients with knee osteoarthritis (OA) experienced a deterioration in muscle coordination when walking. • Loss of muscle coordination was associated with severe knee-related symptoms in knee OA. • Considering muscle coordination as a knee OA symptom-related factor may provide improved treatment.

Hybrid representation-enhanced sampling for Bayesian active learning in musculoskeletal segmentation of lower extremities

PURPOSE

Manual annotations for training deep learning models in auto-segmentation are time-intensive. This study introduces a hybrid representation-enhanced sampling strategy that integrates both density and diversity criteria within an uncertainty-based Bayesian active learning (BAL) framework to reduce annotation efforts by selecting the most informative training samples.

METHODS

The experiments are performed on two lower extremity datasets of MRI and CT images, focusing on the segmentation of the femur, pelvis, sacrum, quadriceps femoris, hamstrings, adductors, sartorius, and iliopsoas, utilizing a U-net-based BAL framework. Our method selects uncertain samples with high density and diversity for manual revision, optimizing for maximal similarity to unlabeled instances and minimal similarity to existing training data. We assess the accuracy and efficiency using dice and a proposed metric called reduced annotation cost (RAC), respectively. We further evaluate the impact of various acquisition rules on BAL performance and design an ablation study for effectiveness estimation.

RESULTS

In MRI and CT datasets, our method was superior or comparable to existing ones, achieving a 0.8% dice and 1.0% RAC increase in CT (statistically significant), and a 0.8% dice and 1.1% RAC increase in MRI (not statistically significant) in volume-wise acquisition. Our ablation study indicates that combining density and diversity criteria enhances the efficiency of BAL in musculoskeletal segmentation compared to using either criterion alone.

CONCLUSION

Our sampling method is proven efficient in reducing annotation costs in image segmentation tasks. The combination of the proposed method and our BAL framework provides a semi-automatic way for efficient annotation of medical image datasets.

Age-related change in gait efficacy and predictors of its decline: A 3-year longitudinal study

AIM

This study aimed to calculate the minimal clinically important difference (MCID) for a modified Gait Efficacy Scale (mGES) over 3 years and to clarify the predictors of mGES decline.

METHODS

In total, 87 community-dwelling older adults were enrolled in this 3-year longitudinal study. The mGES, fall history and physical function (chair stand frequency, open-eyes one-leg stand, open-close stepping test, walking speed, walking endurance [shuttle stamina walk test] and physical activity) were assessed at baseline. After a 3-year follow-up period, the mGES and Global Rating of Change Scale were assessed. The MCID was calculated using anchor-based methods, with the Global Rating of Change Scale as an anchor. The participants were classified into the decline and keep groups based on whether the changes in the mGES were greater than the MCID. A logistic regression analysis was conducted using the mGES as the dependent variable and physical characteristics, fall history, and physical function as independent variables.

RESULTS

The MCID for the mGES over 3 years was -7.38 points. A logistic regression analysis identified low open-close stepping (odds ratio, 0.87; 95% confidence interval, 0.782-0.985; P = 0.027) and the shuttle stamina walk test (odds ratio, 0.974; 95% confidence interval, 0.949-1.000; P = 0.049) as predictors of the mGES decline.

CONCLUSION

These findings suggest that a change of 7.38 points in the mGES was clinically significant and that poor agility and walking endurance can predict future decline in the mGES. Geriatr Gerontol Int 2024; 24: 90-94.

SARS-CoV-2 RT-PCR as a universal screening on planned admission in asymptomatic patients

Universal screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on admission is reportedly beneficial in preventing nosocomial infections. However, some issues remain, including low positivity rate, cost, and time required for testing. We describe SARS-CoV-2 reverse transcription polymerase chain reaction (PCR) for universal screening in asymptomatic patients on planned admissions. In total, 14,574 patients were included between October 12, 2020, and June 23, 2022. The PCR-positive rate for the period was 0.44 % (64/14,574). The PCR positivity for the epidemic period by strain was 0.28 % (95 % confidence interval [CI] 0.12-0.56 %), 0.16 % (95 % CI 0.05-0.37 %), 0.21 % (95 % CI 0.09-0.41 %), and 0.9 % (95 % CI 0.65-1.2 %) for the wild-type strain, Alpha, Delta, and Omicron variants, respectively. The proportion of Ct values < 30 was higher in the first half of the epidemic (first vs. second, 29.4 % [95 % CI 16.9-44.8 %] vs. 16.7 % [95 % CI 6.0-28.5 %]), whereas that of Ct values ≥ 35 increased significantly in the second half (first vs. second, 32.4 % [95 % CI 19.3-47.8 %] vs. 70.0 % [95 % CI 53.5-83.4 %]). Of all positives, 50 % (32/64) had a coronavirus disease (COVID-19) history before PCR screening, with a median of 28 days (10-105) from COVID-19 onset or positive to PCR screening. PCR screening may help detect positives with high viral loads early in the epidemic for each mutant strain, with an increasing proportion of positives with low viral loads later in the epidemic. PCR testing may be unnecessary for recently diagnosed cases and patients in whom reinfection is unlikely.

Pre-stroke physical activity is associated with post-stroke physical activity and sedentary behavior in the acute phase

This study investigated the link between pre-stroke and acute-stage physical activity (PA) and sedentary behavior. Forty individuals with stroke (aged 73.6 ± 8.9 years) were enrolled. Post-stroke activity, including metabolic equivalents (METs), sedentary behavior, light PA, and moderate-to-vigorous PA (MVPA), was measured using a tri-axial accelerometer (ActiGraph wGT3X-BT) over 11 consecutive days starting from the 4th day post-stroke. Pre-stroke PA levels were assessed using the International Physical Activity Questionnaire (IPAQ). We measured skeletal muscle mass index (SMI) and phase angle using a bioelectrical impedance analyzer (Inbody S10) upon admission. Physical therapists assessed the Brunnstrom recovery stage (BRS) within 3 days post-stroke. Total daily activity averaged 1.05 ± 0.05 METs. Throughout the day, 91.2 ± 5.1, 7.6 ± 4.1, and 1.2 ± 1.3% was spent in sedentary behavior, light PA, and MVPA, respectively. Only pre-stroke PA was independently associated with METs (β = 0.66), sedentary behavior (β = -0.58), light PA (β = 0.50), and MVPA (β = 0.71) after adjusting for age, sex, stroke severity, and activities of daily living. This suggests that pre-stroke PA might play a crucial role in reducing sedentary behavior and promoting PA during the acute phase.

Effects of Low-Intensity Torque-Matched Isometric Training at Long and Short Muscle Lengths of the Hamstrings on Muscle Strength and Hypertrophy: A Randomized Controlled Study

ABSTRACT

Nakao, S, Ikezoe, T, Taniguchi, M, Motomura, Y, Hirono, T, Nojiri, S, Hayashi, R, Tanaka, H, and Ichihashi, N. Effects of low-intensity torque-matched isometric training at long and short muscle lengths of the hamstrings on muscle strength and hypertrophy: A randomized controlled study. J Strength Cond Res 37(10): 1978-1984, 2023-This study investigated the effects of low-intensity torque-matched isometric training on muscle hypertrophy and strengthening at long (LL) and short muscle lengths (SL). Twenty-eight young subjects completed an 8-week hamstring isometric training program (30% of maximal voluntary contraction (MVC) × 5 s × 20 repetitions × 5 sets × 3 times/week) at 30° knee flexion (LL) or 90° knee flexion (SL). The cross-sectional area (CSA) of the hamstrings and MVC were measured before and after the intervention. The active torque because of muscle contraction was calculated by subtracting the passive torque at rest from the total torque (30% MVC). The active torque was significantly lower in the LL training group than in the SL training group (p < 0.01), whereas there was no between-group difference in total torque during training. For CSA and MVC at 30° knee flexion, the split-plot analysis of variance (ANOVA) showed no significant time × group interaction; however, it did show a significant main effect of time (p < 0.05), indicating a significant increase after training intervention. As for MVC at 90° knee flexion, there was a significant time × group interaction (p < 0.05) and a significant simple main effect of time in both the LL (p < 0.01; Cohen's d effect size [ES] = 0.36) and SL (p < 0.01; ES = 0.64) training groups. Therefore, low-intensity isometric training at LL can induce hypertrophy and strengthening, even in cases where the active torque production is lower than that at SL, whereas the training at SL may be more effective for muscle strengthening at SL.

Association of Regional Muscle Thickness and Echo Intensity with Muscle Volume, Intramuscular Adipose Tissue, and Strength of the Quadriceps Femoris

Purpose

This study aimed to investigate the association of muscle thickness (MT) and echo intensity (EI) obtained at different regions along the muscle length with muscle volume (MV), intramuscular adipose tissue (IntraMAT), and muscle strength of the quadriceps femoris (QF).

Patients and Methods

A total of 135 community-dwelling adults (64 men and 71 women) participated in the study. Ultrasound scanning of the rectus femoris (RF) and vastus intermedius (VI) was performed at three locations (from mid- to distal thigh). The MT of the RF and VI and EI of the RF were measured. MRI-derived MV, IntraMAT, and muscle strength of the QF were measured.

Results

The correlation between RF-MT and RF-MV weakened as scanning approached the distal thigh, and the difference between the coefficients for the scanning locations was significant for women. However, the correlation of VI-MT with VI-MV and that of the combined MT of RF and VI with the MV of the whole QF and muscle strength were comparable among the scanning locations for both sexes. The correlation of RF-EI with the IntraMAT of the RF and the whole QF and muscle strength was also comparable among the scanning locations for both sexes.

Conclusion

The results of this study suggest that ultrasound measurements at the distal thigh can predict MV, IntraMAT, and muscle strength of the QF to the same degree as those at the mid-thigh.

Ultrasonographic echo intensity in the medial femoral cartilage is enhanced prior to cartilage thinning in women with early mild knee osteoarthritis

PURPOSE

We aimed to determine whether altered cartilage echo intensity is associated with knee osteoarthritis (OA) severity and whether the alteration occurs before thinning of the femoral cartilage in knee OA.

METHODS

The medial femoral cartilage thickness and echo intensity of 118 women aged ≥ 50 years were assessed using an ultrasound imaging device. Based on the Kellgren-Lawrence (KL) grade and knee symptoms, participants were classified into five groups: control (asymptomatic grades 0-1), early OA (symptomatic grade 1), grade 2, grade 3, and grade 4. Analysis of covariance, with adjusted age and height, and the Sidak post hoc test were used to assess the differences in cartilage thickness and echo intensity in knees with varying OA severity.

RESULTS

The echo intensity on longitudinal images, equivalent to the tibiofemoral weight-bearing surface, was significantly higher in the grade 2 group than that in the control group (p = 0.049). However, no significant difference was noted in cartilage thickness (n.s.). In the grades 3 and 4 groups, cartilage thickness became thinner as OA progressed (p < 0.001 and p < 0.001, respectively). However, the cartilage echo intensity was not significantly enhanced compared with that of the grade 2 group (n.s.). There were no significant differences in the cartilage thickness and echo intensity between the early OA and control groups on the longitudinal images (n.s.).

CONCLUSIONS

The echo intensity of the medial femoral cartilage was high in patients with KL grade 2, without decreased thickness. Our findings suggested that higher echo intensity is a feature of early cartilage degeneration in mild knee OA. Further studies are needed to establish this feature as a useful screening parameter of early cartilage degeneration in knee OA.

LEVEL OF EVIDENCE

Level III.

Sitting vs. supine ultrasound measurements of the vastus medialis: correlations with MRI measurements and age considerations

BACKGROUND

Muscle thickness (MT) and echo intensity (EI) measurements are ultrasound alternatives to magnetic resonance imaging (MRI) for evaluating muscle quantity and quality. The vastus medialis (VM) is a clinically important muscle, and assessment methods that most accurately reflect its quantity and quality are required. This study aimed to examine the correlation between MT and EI measured in the supine and sitting postures with corresponding MRI-measured muscle quantity and quality indices.

METHODS

In total, 134 adults (91 older and 43 young) participated in this study. Ultrasound images of the VM were acquired in the supine and sitting postures, and MT and EI were measured. The cross-sectional area (CSA), muscle volume (MV), and intramuscular adipose tissue (intraMAT) of the VM were evaluated from MRI images using T1-weighted and Dixon methods. Pearson's coefficients were used to quantify the correlation strength amongst pairs of dependent variables. Meng's test was used to test for correlation coefficient differences between the two measurement postures (supine and sitting).

RESULTS

The correlation coefficients amongst MT, CSA, and MV were significantly higher in the sitting posture than in the supine posture. EI measured in the supine and sitting postures correlated significantly with intraMAT, and in young individuals, these correlation coefficients were significantly higher in the sitting posture than in the supine posture.

CONCLUSIONS

These findings suggest that assessment of VM muscle quantity in the sitting posture is superior for young and older individuals, and assessment of VM muscle quality in the sitting posture is most effective in younger individuals.

Aggregative movement of C4 mesophyll chloroplasts is promoted by low CO2 under high intensity blue light

C₄ plants supply concentrated CO₂ to bundle sheath (BS) cells, improving photosynthetic efficiency by suppressing photorespiration. Mesophyll chloroplasts in C₄ plants are redistributed toward the sides of the BS cells (aggregative movement) in response to environmental stresses under light. Although this chloroplast movement is common in C₄ plants, the significance and mechanisms underlying the aggregative movement remain unknown. Under environmental stresses, such as drought and salt, CO₂ uptake from the atmosphere is suppressed by closing stomata to prevent water loss. We hypothesized that CO₂ limitation may induce the chloroplast aggregative movement. In this study, the mesophyll chloroplast arrangement in a leaf of finger millet, an NAD-malic enzyme type C₄ plant, was examined under different CO₂ concentrations and light conditions. CO₂ limitation around the leaves promoted the aggregative movement, but the aggregative movement was not suppressed, even at the higher CO₂ concentration than in the atmosphere, under high intensity blue light. In addition, mesophyll chloroplasts did not change their arrangement under darkness or red light. From these results, it can be concluded that CO₂ limitation is not a direct inducer of the aggregative movement but would be a promoting factor of the movement under high intensity blue light.

Red dichromatic imaging improves visibility of bleeding during gastric endoscopic submucosal dissection

Bleeding frequently occurs during gastric endoscopic submucosal dissection (ESD) and bleeding points are sometimes difficult to detect. Red dichromatic imaging (RDI) was recently developed to improve the visibility of bleeding. Our study aimed at examining the efficacy of RDI in improving the visibility of bleeding during gastric ESD. We retrospectively evaluated the visibility score and color difference of bleeding spot during gastric ESD during September 2020-January 2021. The visibility score was evaluated as four numeric values by operators, and the color difference between the bleeding spot and surroundings was evaluated using RDI and white light imaging (WLI). A further analysis to evaluate bleeding characteristics was performed to evaluate the possible beneficial effects of RDI. Twenty patients with a total of 85 bleedings were analyzed. The mean visibility score in RDI was significantly higher than that in WLI (3.69 ± 0.60 vs 3.20 ± 0.84, p < 0.01). The color difference with RDI was also significantly higher than that with WLI (19.51 ± 15.18 vs 14.80 ± 7.41, p < 0.01). Furthermore, in the bleedings with a higher visibility score in RDI, the color difference in RDI was significantly higher than that in WLI (23.99 ± 19.29 vs 14.33 ± 7.08, p < 0.01). The multivariate analysis of visibility scores revealed that submergence of bleeding points was independently associated with the superiority of RDI (odds ratio 10.35, 95% confidence interval: 2.76-38.81, p < 0.01). Our study demonstrates that RDI can improve the visibility of bleeding during gastric ESD.

A higher intramuscular fat in vastus medialis is associated with functional disabilities and symptoms in early stage of knee osteoarthritis: a case-control study

BACKGROUND

The characteristics of muscle degeneration in individual quadriceps in early knee osteoarthritis (OA) and the association of muscle quantity and quality on knee dysfunction remain unclear. This study aimed to clarify the characteristics of muscle degeneration in individual quadriceps muscles in early knee OA and elucidate the association of muscle volume and intramuscular adipose tissue (intraMAT) with knee dysfunction, including functional disabilities, symptoms, and joint morphology.

METHODS

Fifty participants were categorized into early knee OA and healthy control groups. 3.0 T magnetic resonance imaging (MRI) using T1-weighted and Dixon methods and 3D SPACE in the thigh muscle and knee joint regions was performed. Quadriceps muscle volume, intraMAT, and whole-organ MRI score (WORMS) were assessed. The Knee Society Score (KSS) was used to evaluate functional disabilities and knee symptoms. Univariate analysis of variance was conducted with covariates to clarify the differences in muscle volume and intraMAT between the two groups. Multiple linear regression analyses were performed using the KSS function and symptom subcategories and WORMS as dependent variables and muscle volume, intraMAT, and the presence of early knee OA as independent variables, such as potential confounders.

RESULTS

The quadriceps intraMAT, especially in the vastus medialis (VM), was significantly higher in patients with early knee OA than in healthy controls. The VM intraMAT, not muscle volume, was significantly associated with KSS function [B =  - 3.47; 95% confidence interval [CI], - 5.24 to - 1.71; p < 0.001] and symptom scores [B =  - 0.63; 95% CI, - 1.09 to - 0.17; p = 0.008], but not with WORMS.

CONCLUSION

These findings suggest that higher VM intraMAT is characteristic of quadriceps muscle degeneration in early knee OA and its increase is associated with functional disabilities and symptoms.

Machine Learning-Based Prediction of Hospital Admission Among Children in an Emergency Care Center

OBJECTIVES

Machine learning-based prediction of hospital admissions may have the potential to optimize patient disposition and improve clinical outcomes by minimizing both undertriage and overtriage in crowded emergency care. We developed and validated the predictive abilities of machine learning-based predictions of hospital admissions in a pediatric emergency care center.

METHODS

A prognostic study was performed using retrospectively collected data of children younger than 16 years who visited a single pediatric emergency care center in Osaka, Japan, between August 1, 2016, and October 15, 2019. Generally, the center treated walk-in children and did not treat trauma injuries. The main outcome was hospital admission as determined by the physician. The 83 potential predictors available at presentation were selected from the following categories: demographic characteristics, triage level, physiological parameters, and symptoms. To identify predictive abilities for hospital admission, maximize the area under the precision-recall curve, and address imbalanced outcome classes, we developed the following models for the preperiod training cohort (67% of the samples) and also used them in the 1-year postperiod validation cohort (33% of the samples): (1) logistic regression, (2) support vector machine, (3) random forest, and (4) extreme gradient boosting.

RESULTS

Among 88,283 children who were enrolled, the median age was 3.9 years, with 47,931 (54.3%) boys and 1985 (2.2%) requiring hospital admission. Among the models, extreme gradient boosting achieved the highest predictive abilities (eg, area under the precision-recall curve, 0.26; 95% confidence interval, 0.25-0.27; area under the receiver operating characteristic curve, 0.86; 95% confidence interval, 0.84-0.88; sensitivity, 0.77; and specificity, 0.82). With an optimal threshold, the positive and negative likelihood ratios were 4.22, and 0.28, respectively.

CONCLUSIONS

Machine learning-based prediction of hospital admissions may support physicians' decision-making for hospital admissions. However, further improvements are required before implementing these models in real clinical settings.

Differential association of total and regional muscle mass and quality with physical performance in community-dwelling older adults

PURPOSE

In this study, we examined the association among total muscle mass, regional muscle mass, muscle quality, and various types of physical performance in community-dwelling older adults.

METHODS

This study included 195 community-dwelling older adults (61 males and 134 females). The muscle thickness and echo intensity of the quadriceps femoris and triceps surae were measured using ultrasound, and the skeletal muscle mass index was evaluated using bioelectrical impedance analysis. Physical performance was measured using the 30-s standing test (CS30), Timed up-and-go test (TUG), 10-m maximum walking speed (10MWT), vertical jump test (VJT), and grip strength.

RESULTS

Partial correlation analysis after controlling for age, sex, and body mass index showed that CS30 was significantly correlated with muscle thickness and echo intensity of the quadriceps femoris. The TUG and VJT were significantly correlated with muscle thickness of the triceps surae, and grip strength was significantly correlated with muscle thickness of the triceps surae and skeletal muscle mass index. Stepwise multiple regression analyses indicated that the echo intensity of the quadriceps femoris was a significant predictor of CS30, and the muscle thickness of the triceps surae was a significant predictor of TUG, VJT, and grip strength, whereas the skeletal muscle mass index was not a significant predictor of any physical performance test.

CONCLUSION

Our results suggest that regional muscle mass and quality are more important than skeletal muscle mass index for predicting physical performance.

Rectal administration of low-dose diclofenac does not reduce post-endoscopic retrograde cholangiopancreatography pancreatitis: a propensity score matching analysis

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) is a popular technique; however, post-ERCP pancreatitis (PEP) remains a major adverse event. The administration of rectal nonsteroidal anti-inflammatory drugs (NSAIDs) is reportedly effective in preventing PEP. However, the recommended dose varies and the efficacy of low-dose rectal NSAIDs remains unclear. Therefore, we decided to investigate the effectiveness of low-dose rectal diclofenac on PEP prevention, using propensity score matching.

METHODS

This single-center retrospective study included 401 patients who underwent ERCP between July 2015 and March 2020. After December 2016, we administered rectal diclofenac within 30 min before the ERCP procedure as widely as possible. Patients were divided into those who did (diclofenac group) and did not (control group) receive rectal diclofenac. Patients weighing ≥ 50 kg were administered a 50 mg dose, while those weighing < 50 kg were administered a 25 mg dose. The incidence and severity of PEP in the two groups were assessed by propensity score matching analysis.

RESULTS

Among 401 patients undergoing ERCP, 367 fulfilled the inclusion criteria. Overall, 187 patients received rectal diclofenac (diclofenac group) and 180 did not (control group). After propensity score matching, 105 pairs were selected for evaluation. Overall, seven (6.7%) patients in the diclofenac group and 10 (9.5%) in the control group developed PEP (P = 0.45). Moderate or severe PEP occurred in four (3.8%) patients in the diclofenac group and six (5.7%) in the control group (P = 0.52).

CONCLUSIONS

The administration of low-dose rectal diclofenac could not reduce the incidence and severity of PEP.

Enhanced echo intensity in vastus medialis is associated with worsening of functional disabilities and symptoms in patients with knee osteoarthritis: a 3 years longitudinal study

Patients with knee osteoarthritis (OA) experience muscle quality loss, and is characterized by the enhanced echo intensity (EI) of the vastus medialis (VM) muscles and a high extracellular water-to-intracellular water (ECW/ICW) ratio of the thigh. This study aimed to elucidate the association between muscle degeneration and the worsening of functional disabilities and symptoms in patients with KOA over 3 years duration. Thirty-three patients with KOA who completed follow-up over 3 years were included in the analysis. The knee scoring system (KSS) was used to evaluate the functional abilities and symptoms. Based on the 3 years change in KSS scores, patients were classified into progressive or non-progressive groups. Muscle thickness (MT) and EI of the VM were determined using ultrasonography. The ECW/ICW ratio was measured using segmental-bioelectrical impedance spectroscopy. Multivariable logistic regression analyses were conducted with the groups as the dependent variables and VM-MT, VM-EI, and ECW/ICW ratio at baseline as independent variables, including potential confounders. Thirteen (39.4%) patients showed progressive features. VM-EI at baseline was significantly associated with the progression of functional disabilities (adjusted odds ratio [OR] 1.24; 95% confidence interval [CI] 1.03 − 1.50) and symptoms (adjusted OR 1.13; 95% CI 1.01 − 1.25). Enhanced VM-EI was associated with the worsening of functional disabilities and symptoms in patients with KOA over a period of 3 years. Therefore, the assessment of VM-EI using ultrasonography is a useful indicator for predicting the future worsening of KOA.

Properties of the iliotibial band and their relationships with gait parameters among patients with knee osteoarthritis

This study aimed to determine the thickness and stiffness of the iliotibial band (ITB) in patients with knee osteoarthritis (KOA) and to identify the gait parameters that are associated with ITB properties. Eighteen female patients with radiographically diagnosed medial KOA and knee pain (age: 69.7 ± 5.9 years, body mass index: 23.0 ± 3.1 kg/m² ) and 22 age-matched female individuals without knee pain (age: 69.1 ± 7.0 years, body mass index: 21.6 ± 3.6 kg/m² ) were included. Shear wave elastography images were obtained at the height of the proximal pole of the patella with the participants in the supine position, and the ITB thickness and shear wave velocity, which is a surrogate measure of stiffness, were calculated. In patients with KOA, the knee and hip joint angles and moments during walking were calculated using a motion analysis system. The shear wave velocity was significantly higher in patients with KOA than in asymptomatic adults (11.3 ± 1.0 vs. 10.0 ± 1.8 m/s, respectively; p = 0.010); however, the thickness did not differ between them (2.1 ± 0.3 vs. 2.0 ± 0.3 mm, respectively; p = 0.705). The time-integral value of the knee adduction moment (β = 0.507, p = 0.032) and maximum value of the hip flexion moment (β = 0.498, p = 0.036) were associated with the shear wave velocity. Meanwhile, no parameters were associated with the thickness. The ITB was stiffer in patients with KOA than in asymptomatic adults; such a stiffer ITB was associated with greater knee adduction and hip flexion moments during walking. Clinical Significance: Greater mechanical loading was associated with a stiffer ITB in patients with KOA.

Influence of ultrasound focus depth on the association between echo intensity and intramuscular adipose tissue

INTRODUCTION/AIMS

Attenuation of the US wave is a serious limitation of echo intensity (EI) on B-mode ultrasound (US). The aim of this study was to determine if the focus depth of US images influences the depth-dependent attenuation of EI and the relationship between EI and intramuscular adipose tissues (IntraMAT).

METHODS

The rectus femoris (RF) and vastus intermedius (VI) of the right thigh were studied in 135 adults (92 older, 43 younger). The EI on US images was measured at three focus depth conditions: top of the image, center of the RF, and center of the VI. The depth of the region of interest (ROI) was measured. Using water and fat images based on the two-point Dixon technique with 3.0 T MRI scanner, IntraMAT was calculated.

RESULTS

The correlation between EI and IntraMAT was stronger in the focus RF and VI conditions than in the focus top condition and stronger for RF than for VI. The depth of the ROI influenced the IntraMAT-adjusted residual EI more in the focus top condition than in the focus RF and VI conditions, and influenced VI more strongly than it did RF.

DISCUSSION

This study showed that by mitigating EI attenuation, EI with a focus depth adjusted to the ROI reflected IntraMAT more accurately than that without adjustment. However, it may not completely prevent the potential influence of depth-dependent attenuation of EI, especially for deeper muscles such as the VI. This article is protected by copyright. All rights reserved.

OP0090 PRECLINICAL STUDIES OF A NOVEL CATHEPSIN C INHIBITOR IN MPO-ANCA-ASSOCIATED VASCULITIS MODEL

Background

MPO-ANCA-associated vasculitis (MPO-AAV) is a systemic small vessel vasculitis with the production of MPO-ANCA in the serum. This disease develops necrotizing and crescent glomerulonephritis (NCGN) and peritubular capillaritis-mediated interstitial damages in the kidneys, and pulmonary hemorrhage due to capillaritis in the lungs. Recent studies have revealed that neutrophil extracellular traps (NETs) induced by MPO-ANCA are critically involved in its pathogenesis,1 and neutrophil elastase (NE) plays an essential role in the formation of NETs.2 Cathepsin C (CatC) functions as a key enzyme in the activation process of several neutrophil serine proteases (NSPs) such as NE, proteinase 3 and cathepthin G by converting the inactive forms of the NSPs to the active forms by digesting dipeptides at the N-terminus of the enzymes.3

Objectives

Although glucocorticoids and immunosuppressive drugs used as the standard of cares can lead remission in MPO-AAV patients, there are remaining unmet medical needs such as severe side effects, resistance to the treatment and relapse. Therefore, development of new therapeutic strategies is awaited. The aim of this study is to demonstrate the efficacy of MOD06051, a novel CatC inhibitor, against MPO-AAV, using an MPO-AAV rat model established previously.4

Methods

In vitro studies: Cathpsins and NE inhibitory activity was measured using recombinant enzymes and fluorescent substrates. Cellular NE activity in the granulocytes differentiated from the primary human bone marrow-derived hematopietic stem cells under the presence or absence of MOD06051 was determined using fluorescent substrates.

In vivo studies: 4-week-old Wistar Kyoto (WKY) rats were immunized with human MPO according to Little’s protocol.4 The rats were divided into three groups (n=8 in each group), and vehicle (0.5% methylcellulose) or MOD06051 (0.3 or 3 mg/kg bid) was orally administered every day for 42 days. All rats were euthanized at the end of the study for serological and histological evaluations.

Results

In vitro studies: MOD06051 inhibited the enzymatic activity of human recombinant CatC with an IC50 value of 1.5 nM, and no other cathepsins nor NE inhibition was observed at 10 μM. The NE activity in primary human granulocytes was suppressed by MOD06051 with an IC50 value of 18 nM.

In vivo studies: MPO-ANCA was induced in all groups at the same level. The percentage of affected glomeruli including those with NCGN, NET-forming neutrophils in the peripheral blood and glomeruli, and glomerular neutrophil counts were significantly suppressed by MOD06051 treatment in a dose-dependent manner. Furthermore, hematuria score, urinary NGAL (Neutrophil Gelatinase-Associated Lipocalin), tubular erythrocyte cast counts, and pulmonary hemorrhage foci were significantly decreased in the 3 mg/kg of MOD06051 treated group with the similar trends in 0.3 mg/kg group.

Conclusion

MOD06051 showed sepcific inhibition of CatC activity. This compound suppressed the serine proteases activation in primary human neutrophils and NET formation in the MPO-AAV model rats, resulting in amelioration of MPO-ANCA-induced tissue destruction, including NCGN and tubular interstitial damages in the kidneys, and disorder of alveolar septal capillaries in the lungs. MOD06051 appears to be a promising agent for treatment of MPO-AAV patients.

References

[1]Nakazawa D, et al. Nat Rev Rheumatol 15: 91-101, 2019.

[2]Papayannopoulos V, et al. J Cell Biol 191: 677-691, 2010.

[3]Korkmaz B, et al. Pharmacol Ther 190: 202-236, 2018.

[4]Little MA, et al. Am J Pathol 174: 1212-1220, 2009.

Disclosure of Interests

Akihiro Ishizu Grant/research support from: Modulus Discovery, Inc., Mai Taniguchi: None declared, Suishin Arai: None declared, Yuka Nishibata Grant/research support from: Modulus Discovery, Inc., Sakiko Masuda Grant/research support from: Modulus Discovery, Inc., Utano Tomaru: None declared, Takafumi Shimizu Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., William Sinko Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Tadashi Nagakura Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc., Yoh Terada Shareholder of: Modulus Discovery, Inc., Employee of: Modulus Discovery, Inc.

Age- and sex-related differences of muscle cross-sectional area in iliocapsularis: a cross-sectional study

Background

This study aimed to determine in how many individuals the iliocapsularis muscle (IC) could be identified on magnetic resonance imaging (MRI) and whether age and sex are associated with the cross-sectional area (CSA) of the IC.

Methods

Thirty-seven healthy younger adults and 40 healthy older adults were assigned to four groups: 1) 20 younger men; 2) 17 younger women; 3) 20 older men; and 4) 20 older women. The CSAs of the IC, IP, the rectus femoris (RF) and the quadriceps (QUAD) were quantified on an axial MRI.

Results

The number of individuals with the identified IC was n = 17 (85.0%) of 20 younger men, n = 15 (88.2%) of 17 younger women, n = 18 (90.0%) of 20 older men, and 19 (95.0%) of 20 older women. Our results showed the main effect of sex, but not age, in the CSA of the IC. The men-groups had larger CSA of the IC than the women-groups; however, no difference in CSA of the IC was found between the younger and older groups. Meanwhile, the main effects of age and sex were found for the IP, RF, and QUAD; thus, younger or men groups have larger CSAs of the three muscles than the older or women groups. The IC muscle can be discriminated in 85% – 95% of healthy individuals.

Conclusion

Although sex and age are associated with the CSA of lower-limb muscles other than the IC, only sex is associated with the CSA of the IC.

Properties of triceps surae and Achilles tendon in forefoot and non-forefoot strike runners

BACKGROUND

The purpose of this study was to compare the properties of the triceps surae and Achilles tendon of forefoot strike runners and non-forefoot strike runners.

METHODS

Fourteen male college forefoot strike runners and 11 non-forefoot strike runners participated in this study. The shear elastic moduli and cross-sectional areas of the medial and lateral gastrocnemius, soleus, and Achilles tendon were measured. Passive ankle joint stiffness, maximum voluntary isometric contraction on plantar flexion and rebound jump index were also measured.

RESULTS

Forefoot strike runners had higher shear elastic moduli of the medial and lateral gastrocnemius, higher passive ankle joint stiffness, higher rebound jump index, and greater crosssectional area of the gastrocnemius and Achilles tendon than non-forefoot strike runners.

CONCLUSIONS

These findings suggest that forefoot strike runners have different mechanical properties in the gastrocnemius muscles, and different morphological properties in the Achilles tendon and gastrocnemius muscles, compared with non-forefoot strike runners.

Interstitial Lung Disease Associated with <b><i>Agaricus blazei</i></b> Murill in a Patient with Pancreatic Ductal Adenocarcinoma Receiving Gemcitabine-Based Therapy

A male in his sixties with locally advanced pancreatic ductal adenocarcinoma (PDAC) was administered gemcitabine plus nab-paclitaxel therapy. Computed tomography (CT) scans after five courses revealed nonspecific interstitial pneumonitis in addition to PDAC aggravation. No evidence of respiratory infection was detected, and his condition was stable and asymptomatic at diagnosis. Sputum test and interferon-gamma release assay revealed no evidence of tuberculosis. Through careful history taking, the patient was found to be taking dietary supplementation with Agaricus blazei Murill extract for approximately 1 month. Drug-induced lymphocyte stimulation tests for gemcitabine and nab-paclitaxel were negative, whereas those for Agaricus blazei Murill were positive. CT scans after withdrawal showed improved pneumonitis. These findings suggest a possibility that the dietary supplementation may lead to drug-induced interstitial lung disease (ILD). This patient indicates that pertinent diagnostic interviews are essential for the identification of drug-induced ILD.

Association of Physical Activity and Nutritional Intake with Muscle Quantity and Quality Changes in Acute Stroke Patients

OBJECTIVES

To evaluate longitudinally the muscle properties of acute stroke patients and examine the association between physical activity and nutritional intake.

MATERIALS AND METHODS

This study enrolled 21 stroke patients (72.7±10.4 years). Muscle quantity (fat-free mass, appendicular skeletal muscle mass) and quality (extracellular water/intracellular water ratio, phase angle) were assessed using a bioelectrical impedance device at baseline (within three days) and two weeks after stroke onset. Physical activity and sedentary were calculated from the accelerometer data. Total energy and protein intake were calculated from the dietary surveys as nutritional intake. The association of physical activity, sedentary, and nutritional intake with the rate of changes in muscle properties was examined.

RESULTS

The fat-free mass significantly decreased (from 43.4±8.0 to 42.2±7.6 kg), and the skeletal muscle was unchanged (from 17.8±4.2 to 17.7±4.0 kg) after two weeks. The extracellular water/intracellular water ratio significantly increased (from 0.63±0.02 to 0.65±0.03) and the phase angle significantly decreased (from 5.1±0.6 to 4.9±0.8°), suggesting that the muscle quality have declined. Correlation analysis showed that the extracellular water/intracellular water ratio was significantly associated with physical activity [metabolic equivalents (ρ=-0.61)] and sedentary (ρ=0.67) and that the phase angle was significantly associated with physical activity [metabolic equivalents (ρ=0.69)], sedentary (ρ=-0.68), and nutritional intake [total energy (r=0.45), protein (r=0.45)].

CONCLUSIONS

The fat-free mass and muscle quality (extracellular water/intracellular water ratio and phase angle) declined two weeks after stroke. Physical activity and nutritional intake were lower in patients with decreased muscle quality, suggesting the importance of exercise and nutrition in the acute phase.

Angelica keiskei (Ashitaba) has potential as an antithrombotic health food

Angelica keiskei (Ashitaba) is a large perennial herb that is native to the Pacific coast of Japan. It has recently become popular as a healthy food in Asian countries because it might have various physiological benefits including antithrombotic properties. Most studies of the bioactive constituents from Ashitaba have focused on the activities of the major chalcones, xanthoangelol and 4-hydroxyderricin. However, other chalcones, flavanones and coumarins have also been isolated from Ashitaba, precisely characterized, and investigated in vivo. Platelets play a key role in haemostasis and wound healing processes. Dysregulated platelet activity is associated with the progression of platelet aggregation and decreased venous blood flow, which results in thrombotic diseases. A minor chalcone, xanthoangelol E, inhibits TXB2 synthesis in rabbit platelets, which seems to be the source of the belief that Ashitaba has antithrombotic properties. However, recent data showed that xanthoangelol and 4-hydroxyderricin inhibited the aggregation of rabbit platelets. Platelet aggregation stimulated by collagen was also inhibited in whole blood incubated with Xanthoangelol or 4-hydroxyderricin. Plasminogen activator inhibitor-1 is the primary physiological inhibitor of tissue type plasminogen activator, a key protease of the fibrinolytic system. An increase in plasma of this inhibitor is associated with thrombotic conditions. Ashitaba yellow exudate inhibited the elevation of plasma plasminogen activator inhibitor-1 in mice induced by obesity or chronic low-grade inflammation. These studies showed the yellow exudate from stem cuttings and chalcones isolated from Ashitaba roots and leaves might have antithrombotic activity. This article reviews the possible antithrombotic properties of Ashitaba.

Relationship Between Muscle Swelling and Hypertrophy Induced by Resistance Training

ABSTRACT

Hirono, T, Ikezoe, T, Taniguchi, M, Tanaka, H, Saeki, J, Yagi, M, Umehara, J, and Ichihashi, N. Relationship between muscle swelling and hypertrophy induced by resistance training. J Strength Cond Res 36(2): 359-364, 2022-Muscle swelling immediately after resistance exercise may be induced by metabolic stress. The accumulation of metabolic stress is considered to promote muscle hypertrophy after several weeks of resistance training (RT). The purpose of this study was to determine the relationship between muscle swelling immediately after the first session of RT and muscle hypertrophy after a 6-week RT using ultrasonography. Twenty-two untrained young men performed knee extension resistance exercise consisting of 3 sets with 8 repetitions at a load of 80% of one repetition maximum for 6 weeks (3 d·wk-1). Muscle thickness of the quadriceps femoris was measured using ultrasonography device at 3 anatomical sites (proximal, medial, and distal sites) of the middle, lateral, and medial part of the anterior thigh. The sum of the muscle thickness at 9 measurement sites was used for analysis. Acute change in muscle thickness immediately after the first session of RT was used as an indicator of muscle swelling. Chronic change in muscle thickness after the 6-week RT was used as an indicator of muscle hypertrophy. A significant increase in muscle thickness was observed immediately after the first session of RT (8.3 ± 3.2%, p < 0.001). After the 6-week RT, muscle thickness increased significantly (2.9 ± 2.6%, p < 0.001). A significant positive correlation was found between muscle swelling and muscle hypertrophy (ρ = 0.443, p = 0.039). This study suggests that the greater the muscle swelling immediately after the first session of RT, the greater the muscle hypertrophy after RT.

Acute effects of ankle plantar flexor force-matching exercises on postural strategy during single leg standing in healthy adults

BACKGROUND

Ankle plantar flexor force steadiness, assessed by measuring the fluctuation of the force around the submaximal target torque, has been associated with postural stability.

RESEARCH QUESTION

To investigate whether a force-matching exercise, where submaximal steady torque is maintained at the target torque, can modulate postural strategy immediately.

METHODS

Twenty-eight healthy young adults performed ankle plantar flexor force-matching exercises at target torques of 5%, 20%, and 50% of maximum voluntary contraction (MVC), in a randomized crossover trial. Participants with their ankle in a neutral position were instructed to maintain isometric contraction at each target torque, as measured by a dynamometer, for 20 s with 3 sets of 5 contractions. Before and after the force-matching exercises, the anterior-posterior velocities and standard deviation of the center of pressure (COP) on the stable platform and the tilt angle of the unstable platform during 20-seconds single-leg standing were measured. The velocities and standard deviations of the COP and tilt angle before and after the exercises were compared using paired t-tests.

RESULTS

The tilt angle velocity of an unstable platform significantly decreased after the force-matching exercise at a target torque of 5% MVC (p = 0.029), whereas it was unchanged after the exercises at target torques of 20% and 50% MVC. The standard deviations of the tilt angle of unstable platform test did not change significantly after any exercise. Furthermore, no significant differences were observed in the COP velocities or standard deviations on the stable platform test after any exercise.

SIGNIFICANCE

Our findings suggest that repeated exertion training at low-intensity contractions can affect postural stability in an unstable condition. Particularly, force-matching exercise at very low-intensity torque, such as 5% of MVC, may be an effective method to improve postural control in the unstable condition, but not in a stable condition.

Hybridization of Bogoliubov Quasiparticles between Adjacent CuO_{2} Layers in the Triple-Layer Cuprate Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{10+δ} Studied by Angle-Resolved Photoemission Spectroscopy

Hybridization of Bogoliubov quasiparticles (BQPs) between the CuO_{2} layers in the triple-layer cuprate high-temperature superconductor Bi_{2}Sr_{2}Cu_{2}Cu_{3}O_{10+δ} is studied by angle-resolved photoemission spectroscopy (ARPES). In the superconducting state, an anticrossing gap opens between the outer- and inner-BQP bands, which we attribute primarily to interlayer single-particle hopping with possible contributions from interlayer Cooper pairing. We find that the d-wave superconducting gap of both BQP bands smoothly develops with momentum without an abrupt jump in contrast to a previous ARPES study. Hybridization between the BQPs also gradually increases in going from the off nodal to the antinodal region, which is explained by the momentum dependence of the interlayer single-particle hopping. As possible mechanisms for the enhancement of the superconducting transition temperature, the hybridization between the BQPs as well as the combination of phonon modes of the triple CuO_{2} layers and spin fluctuations represented by a four-well model are discussed.

Association between adherence to home-based walking exercise with a pedometer and one-year adverse outcomes among lower extremity peripheral artery disease patients with endovascular treatment

Background

Home-based exercise after endovascular treatment (EVT) for lower extremity peripheral artery disease (LE-PAD) patients with intermittent claudication is suggested as an alternative therapy for supervised exercise; however, an association of adherence to home-based exercise with clinical adverse events has not been fully investigated.

Purpose

We aimed to investigate the association of adherence to home-based exercise with 1-year major adverse events (MAE), patency, and leg symptoms after EVT in a contemporary Japanese registry.

Methods

A total of 500 patients with LE-PAD within the Long Term Outcome of Endovascular Therapy for PAD with Intermittent Claudication Observational Prospective Multicenter (ASHIMORI-IC) registry (UMINCTR, UMINehab724.203718753) who underwent EVT between January 2016 and March 2019 were included in the analysis. After EVT, all patients were instructed to do home-based walking exercise with a pedometer. The study population was divided and compared between 2 groups according to adherence to home-based exercise: well-adherence and poor-adherence. The adherence of home-based exercise was as defined by step count derived from a pedometer on sites. The primary outcome was MAE defined as composite of all-cause death, myocardial infarction, stroke, target vessel revascularization, and major amputation of target lower limb for one year. The main secondary outcome was 1-year primary patency of the treated lesion, and the improvement of leg symptom (6-minute walk distance [6MWD] and claudication distance). The study followed the Consensus definitions from peripheral academic research consortium criteria.

Results

Overall, the mean age was 72.8 years, and 78% were men. At 1 year, MAE occurred in 45 patients (9.0%), and the primary patency rate was 85.3% (94.2% of EVT for aortoiliac and 71.9% of EVT for femoropopliteal). A significant difference in the incidence of MAE was observed between the well-adherence group and the poor-adherence group (10 of 233 patients [4.3%] vs. 35 of 267 patients [13.1%]; P&lt;0.001). After multivariate Cox regression analysis, patients in the well-adherence group showed the lower hazard ratio for 1-year MAE (0.30; 95% confidence interval, 0.15–0.58; P&lt;0.001) compared to those in the poor-adherence group. In the well-adherence group, compared with the poor-adherence group, higher primary patency rate (88.9% vs 81.5%; p=0.015), longer claudication onset distance (370 m [IQR 240–453 m] vs 240m [IQR 126–324 m]; P&lt;0.001), and longer 6MWD (422 m [IQR 359–483 m] vs 325 m [IQR 213–400 m]; P&lt;0.001) were observed even after adjusting for each baseline value.

Conclusion

Our study demonstrates the importance of adherence to home-based walking exercise after EVT in LE-PAD patients.

Funding Acknowledgement

Type of funding sources: None.

Estimating thigh skeletal muscle volume using multi-frequency segmental-bioelectrical impedance analysis

Background

The primary aim of this study was to investigate whether using the extracellular water/intracellular water (ECW/ICW) index and phase angle combined with segmental-bioimpedance analysis (BIA) improved the model fitting of skeletal muscle volume (SMV) estimation. The secondary aim was to compare the accuracy of segmental-BIA with that of ultrasound for estimating the quadriceps SMV measured with MRI.

Methods

Seventeen young men (mean age, 23.8 ± 3.3 years) participated in the study. The T-1 weighted images of thigh muscles were obtained using a 1.5 T magnetic resonance imaging (MRI) scanner. Thigh and quadriceps SMVs were calculated as the sum of the products of anatomical cross-sectional area and slice thickness of 6 mm across all slices. Segmental-BIA was applied to the thigh region, and data on the 50-kHz bioelectrical impedance (BI) index, ICW index, ECW/ICW index, and phase angle were obtained. The muscle thickness index was calculated as the product of the mid-thigh muscle thickness, determined using ultrasound, and thigh length. The standard error of estimate (SEE) of the regression equation was calculated to determine the model fitting of SMV estimation and converted to %SEE by dividing the SEE values by the mean SMV.

Results

Multiple regression analysis indicated that the combination of 50-kHz BI and the ECW/ICW index or phase angle was a significant predictor when estimating thigh SMV (SEE = 7.9 and 8.1%, respectively), but were lower than the simple linear regression (SEE = 9.4%). The ICW index alone improved the model fitting for the estimation equation (SEE = 7.6%). The model fitting of the quadriceps SMV with the 50-kHz BI or ICW index was similar to that with the skeletal muscle thickness index measured using ultrasound (SEE = 10.8, 9.6 and 9.7%, respectively).

Conclusions

Combining the traditionally used 50-kHz BI index with the ECW/ICW index and phase angle can improve the model fitting of estimated SMV measured with MRI. We also showed that the model suitability of SMV estimation using segmental-BIA was equivalent to that on using ultrasound. These data indicate that segmental-BIA may be a useful and cost-effective alternative to the gold standard MRI for estimating SMV.

Prevalence and physical characteristics of locomotive syndrome stages as classified by the new criteria 2020 in older Japanese people: results from the Nagahama study

Background

The Japanese Orthopaedic Association (JOA) proposed the concept of locomotive syndrome (LS) in 2007 for detecting high-risk individuals with mobility limitation. In 2020, the JOA revised the clinical decision limits and introduced LS stage 3, which carried the highest-risk for LS compared to the conventional stages, 1 and 2. The purpose of this study was to characterize the prevalence, comorbidities, and physical characteristics in each LS stage, as per the LS criteria 2020.

Methods

We analyzed 2077 participants (64.9% women; mean age, 68.3 ± 5.4 years) from the Nagahama Study aged ≥60 years. Participants were classified into 4 groups, non-LS and LS stages 1, 2, and 3, based on a 25-question Geriatric Locomotive Function Scale. The prevalence of comorbidities (sarcopenia, osteoporosis, diabetes mellitus, low back pain [LBP], and knee pain) were investigated. Physical characteristics were measured based on the physical performance tests including gait speed, five-times chair-stand, single-leg stand, and short physical performance battery; muscle strength tests including grip, knee extension, hip flexion, and abduction; and body-composition analysis including muscle quantity and quality. Differences in the prevalence of comorbidities between LS stages were tested using the chi-square test. The general linear model was performed for univariate and multivariate analyses with post-hoc test to compare the differences in physical characteristics among the LS stages.

Results

The prevalence of LS increased with age, and the mean prevalence of LS stages 1, 2, and 3 were 24.4, 5.5, and 6.5%, respectively. The prevalence of comorbidities, including sarcopenia, osteoporosis, LBP, and knee pain, increased with worsening LS stage. Physical performance tests were significantly different between LS stages 2 and 3; and muscle strength differed significantly between LS stages 1 and 2. Additionally, in terms of body composition analysis, muscle quality but not muscle quantity showed significant differences among all the LS stages.

Conclusions

Our findings suggest that muscle strengthening and dynamic training, including balance training in LS stage 1 and 2, respectively, were needed for preventing the LS progression. Individuals with LS stage 3 should perform dynamic training and muscle strengthening exercises while receiving treatment for comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02440-2.

Physical Activity Mediates the Relationship between Gait Function and Fall Incidence after Total Knee Arthroplasty

The present study aims to examine (1) the preoperative factors that can predict postoperative falls, (2) whether postoperative physical activity (PA) mediates the relationship between fall incidence and gait function, and (3) whether postoperative PA levels are associated with fall risk in total knee arthroplasty (TKA) patients. Ninety-six patients (mean age: 72.0 ± 6.1 years) who were observed postoperatively for 6 months were selected. Timed up and go (TUG) was assessed as an indicator of gait function. Fall incidence and PA were investigated for 6 months post-TKA. The body mass index, history of preoperative falls, knee pain, knee extensor strength, range of motion in knee flexion, and modified gait efficacy scale were evaluated. Additionally, postoperative PA levels were categorized into three groups-low: <3,000, moderate: 3,000 to 4,000, and high: ≥4,000 steps/day. The relative fall incidence rate was calculated according to the total number of falls normalized for every 1,000 steps/day for 6 months postoperatively. Twenty-five (26.0%) of the 96 patients had at least one fall. The TUG, knee pain, and knee extensor strength were identified preoperatively as significant variables affecting postoperative falls. The mediated effects model revealed that postoperative fall incidence was predicted by preoperative TUG and postoperative PA. Postoperative PA was significantly associated with preoperative TUG. Moreover, both the preoperative TUG and postoperative PA were selected as significant variables for predicting fall incidence. Thus, postoperative PA mediates the relationship between gait function and fall incidence after TKA. Furthermore, the relative fall incidence rate associated with a low PA level was significantly higher than that associated with moderate and high PA levels. In conclusion, preoperative assessments of TUG performance, muscle strength, and knee pain were effective in predicting fall risk. Additionally, an increase in PA could contribute to reducing fall risk in TKA patients. Therefore, our results suggest that preoperative screening for fall predictors and managing postoperative PA could reduce the fall incidence in TKA patients.

Severe Liver Injury Associated with Glecaprevir Plus Pibrentasvir Therapy in a Patient with Treatment-naïve Hepatitis C Virus Infection

A 49-year-old man underwent treatment with glecaprevir plus pibrentasvir (G/P) for chronic hepatitis C infection. Six weeks later, he was admitted to our hospital because of jaundice and fatigue with no accompanying skin rash. A laboratory examination and evaluation of the patient's history resulted in a diagnosis of acute liver injury. Discontinuation of G/P and a rigorous medical protocol, including plasma exchange and hemodiafiltration, successfully mitigated the liver damage. The patient was also found to be allergic to two drugs other than the G/P therapy. In such cases with a history of drug allergy, careful observation may be required to detect serious adverse events.

Cut-off Values for Lower Limb Muscle Thickness to Detect Low Muscle Mass for Sarcopenia in Older Adults

Purpose

Ultrasound-based prediction methods for the detection of low muscle mass for sarcopenia in older adults have been explored previously; however, the muscle that most accurately predicts it is unclear. This study aimed to clarify prediction accuracy and cut-off values for ultrasound-derived thigh and lower leg muscle thickness (MT) to detect low skeletal muscle mass index (SMI) in older adults and to estimate cut-off values based on two standard deviations (SD) below younger adult means for the corresponding muscles as an early detection tool for site-specific low muscle mass.

Methods

This study included 204 community-dwelling older (64 males, 140 females, mean age: 75.4 years) and 59 younger (31 males, 28 females, mean age: 22.3 years) adults. The MT of the rectus femoris, vastus intermedius, gastrocnemius, and soleus muscles was measured using ultrasound; SMI was measured using bioelectrical impedance analysis.

Results

The prevalence of a low SMI among older adults was 20.3% (n=13) for males and 21.4% (n=30) for females. The receiver operating characteristic analysis revealed that the total MT for the four muscles measured presented the highest area under the curve (AUC) value to predict low SMI for males (0.849) and females (0.776). The AUC value was the highest for the total MT of the gastrocnemius and soleus muscles for males and the gastrocnemius for females (0.836, 0.748; cut-off value: 5.67 cm, 1.42 cm, respectively). Muscle-specific differences between the low SMI-predicting and SD-based cut-off values were observed. The SD-based value for the rectus femoris (1.85 cm) was substantially higher than the low SMI-predicting value (1.51 cm) in males.

Conclusion

Ultrasound measurement of lower leg muscles may be a simple, robust measure to detect low muscle mass for sarcopenia. Additionally, cut-off values for site-specific muscle mass loss may not always agree with those for whole-limb muscle mass loss.

Correlation between irreversible organ damage and the quality of life of patients with systemic lupus erythematosus: The Kyoto Lupus Cohort survey

OBJECTIVES

It is important to clarify the relationship between irreversible organ damage and the quality of life (QOL) by considering the unique factors of patients with systemic lupus erythematosus (SLE). We aimed to clarify their correlation using SLE-specific QOL assessment tools. We also aimed to identify which type of organ damage is adversely correlated with the QOL.

METHODS

We conducted a questionnaire-based survey of outpatients with SLE at Kyoto University Hospital and evaluated irreversible organ damage using the SLICC/ACR damage index (SDI). LupusPRO and the SLE symptom checklist (SSC) were employed as SLE-specific QOL tools, and the SF-36v2 was used as a conventional QOL tool. Multiple linear regression analyses were performed to examine the correlations between the total SDI score and each QOL score, and between each SDI item/system score and each QOL score.

RESULTS

We analyzed the data of 265 patients. The total SDI score was significantly correlated with physical (PCS) and role/social component summary (RCS) of the SF-36v2, health-related QOL (HRQOL) of LupusPRO, and SSC (p < 0.001). Among the SDI items, atrophy/weakness and osteoporosis with fracture/vertebral collapse were negatively correlated with PCS (β = -0.40, p < 0.001/β = -0.28, p < 0.001), RCS (β = -0.30, p < 0.001/β = -0.35, p < 0.001), and HRQOL (β = -0.34, p < 0.001/β = -0.31, p < 0.001), respectively. Among the SDI systems, musculoskeletal damage had higher negative correlations with PCS (β = -0.51, p < 0.001), RCS (β = -0.29, p < 0.001), and HRQOL (β = -0.40, p < 0.001).

CONCLUSION

We demonstrated the QOL of patients with SLE is negatively correlated with irreversible organ damage. We also revealed musculoskeletal damage is adversely correlated with the health-related QOL, especially the physical and role/social QOL.

The use of ultrasound in central vascular ligation during laparoscopic right-sided colon cancer surgery: technical notes

BACKGROUND

Complete mesocolic excision (CME) with central vascular ligation (CVL) requires the surgeon to sharply dissect the mesocolon and approach the superior mesenteric artery (SMA) and superior mesenteric vein (SMV) for ligation of the supplying vessels relating to right-sided colon cancer at their origin. Even with preoperative images, it can still be challenging to identify these structures during laparoscopic surgery because of various intraoperative conditions. The aim of this study was to assess the efficacy of intraoperative ultrasound (IOUS) for identification of blood vessels during right-sided colon cancer surgery.

METHODS

We performed IOUS on 19 patients diagnosed with right-sided colon cancer at our institution, in January-October 2020. Preoperatively, a three-dimensional computed tomography (3D-CT) angiogram was obtained for the majority of patients to visualize the SMA, SMV, and their respective branches. The running position of the ileocolic artery (ICA) and right colic artery (RCA) related to the SMV and the presence of the middle colic artery were identified and compared using preoperative 3D-CT, IOUS, and intraoperative findings.

RESULTS

Nineteen patients [seven men and 12 women with a mean age of 73.9 ± 8.4 years (range 58-82 years)] were studied, including some with a body mass index of > 30 kg/m², locally advanced cancer, and severe adhesion. There were IOUSs that detected the SMA, SMV, and their tributaries in all patients. The positional relationships between the SMV and the ICA and RCA revealed by IOUS were consistent with the preoperative and intraoperative findings.

CONCLUSION

IOUS is a safe, feasible, and reproducible technique that can assist in detecting the branching of the SMA and SMV during CME with CVL in laparoscopic right-sided colon cancer surgery, regardless of individual conditions.

The effects of knee pain on knee contact force and external knee adduction moment in patients with knee osteoarthritis

Knee osteoarthritis (OA) is a major cause of knee pain, leading to physical dysfunction. External knee adduction moment (KAM), a surrogate measure of knee contact force (KCF) in the medial compartment, is related to knee pain, but the association between KCF and pain severity remains unclear. This study aimed to reveal the differences in KCF due to pain severity. Twenty-eight patients with knee OA were evaluated knee symptoms including pain severity via the Knee Society Score. Based on the median symptom score, 17 points in this study, subjects were classified as having Mild symptomatic OA (n = 15) and Severe symptomatic OA (n = 13). Subjects walked three times at a comfortable speed along a six-meter walkway, and we calculated KAM during the stance phase. KCF magnitude and distribution were also computed using the subject-specific musculoskeletal model, considering physical characteristics such as the femorotibial angle measured by X-ray. No differences in physical characteristics such as femorotibial angle and gait speed were found by symptom severity, whereas KAM and medial KCF at minimum and second peak in Severe symptomatic OA patients were significantly greater than those in Mild symptomatic OA. A significant medial shift of KCF in Severe symptomatic OA was also seen at first peak and minimum. Severe symptomatic OA had a greater medial KCF and medial shift of KCF. Detailed evaluations of KCF magnitude and distribution in addition to KAM would provide crucial information on knee contact force in relation to symptom severity.

Validation and verification of the Japanese version of the systemic lupus erythematosus symptom checklist for patient quality of life

OBJECTIVE

The systemic lupus erythematosus (SLE) symptom checklist (SSC) is a patient-reported outcome measure consisting of 38 queries. We translated SSC into Japanese and attempted to validate its usefulness for evaluating the quality of life (QOL) of SLE patients and identify factors that affect QOL.

METHODS

Data from the Medical Outcomes Study Short-form 36 questionnaire (SF-36), Japanese LupusPRO, the Japanese version of the SSC (SSC-J) questionnaire, SLEDAI-2k, and the physician global assessment (PGA) were obtained on the same day from 226 SLE outpatients of the Kyoto Lupus cohort at Kyoto University Hospital. Relationships between the total scores or each item of SSC-J and SF-36, Japanese LupusPRO, SLEDAI-2k, or PGA were analyzed by Spearman's rank test.

RESULTS

The total scores of SSC-J correlated with the scores of SF-36 and Japanese LupusPRO. In each item of SSC-J, all 38 items correlated with the physical component summary and mental component summary of SF-36 as well as the Health-Related QOL (HRQOL) scores of Japanese LupusPRO, but not with the non-HRQOL of LupusPRO. SSC-J scores correlated with age, PGA, and corticosteroid doses, but not with SLEDAI-2k.

CONCLUSIONS

SSC-J is suitable as a disease-specific QOL assessment tool for SLE.

Acute effects of repetitive peripheral magnetic stimulation following low-intensity isometric exercise on muscle swelling for selective muscle in healthy young men

Repetitive peripheral magnetic stimulation (rPMS) is a non-invasive stimulator that can induce strong muscle contraction in selective regions. This study aimed to measure acute changes in skeletal muscle thickness induced by rPMS following a low-intensity exercise. Fifteen healthy young men performed an isometric knee extensor exercise at 30% of maximum strength consisting of three sets of 10 contractions on their dominant leg. rPMS was then applied on the vastus lateralis (VL) at the maximum intensity of the rPMS device. Muscle thicknesses of the rectus femoris (RF) and VL were measured using an ultrasound device and were compared among baseline, post-exercise, and post-rPMS. There were significant increases in muscle thickness of both the RF and VL post-exercise compared with baseline values (RF: baseline; 24.7 ± 2.4, post-exercise; 25.3 ± 2.4 mm, p = .034, VL: baseline; 27.0 ± 2.8, post-exercise; 27.4 ± 2.8 mm, p = .006). Compared with post-exercise, there was a significant increase post-rPMS in only the VL (VL: post-rPMS; 28.3 ± 2.9 mm, p = .002). These findings suggest that low-intensity isometric exercise can induce acute increases in muscle thickness (muscle swelling) in synergist muscles, and rPMS following exercise can induce further acute muscle swelling via repetitive muscle contraction.