Pathogenic Potential of Eomesodermin-Expressing T-Helper Cells in Neurodegenerative Diseases.

Eomesodermin-expressing (Eomes+) T-helper (Th) cells show cytotoxic characteristics in secondary progressive multiple sclerosis. We found that Eomes+ Th cell frequency was increased in the peripheral blood of amyotrophic lateral sclerosis and Alzheimer's disease patients. Furthermore, granzyme B production by Th cells from such patients was high compared with controls. A high frequency of Eomes+ Th cells was observed in the initial (acutely progressive) stage of amyotrophic lateral sclerosis, and a positive correlation between Eomes+ Th cell frequency and cognitive decline was observed in Alzheimer's disease patients. Therefore, Eomes+ Th cells may be involved in the pathology of amyotrophic lateral sclerosis and Alzheimer's disease. ANN NEUROL 2024.

Detailed Lipid Profiles and Lipid-related Residual Risk after 12-week 10 mg Rosuvastatin Treatment for Acute Myocardial Infarction.

Objective We aimed to reveal detailed on-treatment lipid profiles, lipid-related surrogate markers, and factors predicting failure to achieve the guideline-recommended lipid management goal following guideline-recommended statin treatment in Japanese patients with acute myocardial infarction (AMI). Methods and Results Sixty AMI patients who underwent coronary intervention and had received rosuvastatin 10 mg/day since the start of their hospitalization were assessed for on-treatment lipid-related profiles, including high-sensitivity C-reactive protein, small dense low-density lipoprotein cholesterol (sd LDL-C), and lipoprotein (a), at the 12-week follow-up. Patients who failed to achieve the guideline-recommended lipid management at 12 weeks were defined as the "unachieved group." Univariate and multivariate logistic regression analyses were performed to evaluate the predictors of inclusion in the unachieved group after high-dose statin treatment. Despite the use of high-dose rosuvastatin, 61.7% of the enrolled AMI patients were included in the unachieved group. In addition, the unachieved group had higher sd LDL-C and lipoprotein (a) levels than the achieved group. Logistic regression analyses demonstrated that low baseline high-density lipoprotein cholesterol (HDL-C) levels and the absence of diabetes were predictors of inclusion in the unachieved group. Conclusion More than half of the Japanese AMI patients treated with rosuvastatin 10 mg/day did not achieve the guideline-recommended goal of lipid management and still had lipid-related residual risk at 12 weeks. Particular attention should be paid to patients with low baseline HDL-C levels and those without diabetes with regard to their on-treatment lipid profiles.

Influence of microarchitecture on stressed volume and mechanical fatigue behaviour of equine subchondral bone.

Fractures of the equine metacarpophalangeal (MCP) joint are among the most common and fatal injuries experienced by racehorses. These bone injuries are a direct result of repetitive, high intensity loading of the skeleton during racing and training and there is consensus that they represent a mechanical fatigue phenomenon. Existing work has found the fatigue life of bone to be strongly determined by bone microarchitecture and the resulting stressed volume (i.e., the volume of bone stressed above assumed yield). The purpose of this study was to quantify the influence of bone microarchitecture on the mechanical fatigue behaviour of equine subchondral bone from the MCP joint across a wide variety of sample types. Forty-eight subchondral bone samples were prepared from the third metacarpal (MC3) and proximal phalanx (P1) of 8 horses and subsequently imaged using high resolution micro-computed tomography (µCT) to quantify microarchitectural features of interest, including bone volume fraction, tissue mineral density, pore size, pore spacing, and pore number. Samples were cyclically loaded in compression to a stress of 70 MPa, and fatigue life was defined as the number of cycles until failure. Finite element models were created from the µCT images and used to quantify stressed volume. Based on the expected log point-wise predictive density, stressed volume was a strong predictor of fatigue life in both the MC3 and P1. A regional analysis indicated fatigue life was more strongly associated with bone volume fraction in the superficial (r2 = 0.32, p < 0.001) and middle (r2 = 0.70, p < 0.001) regions of the subchondral bone, indicating the prominent role that the cortical plate played in the fatigue resistance of equine subchondral bone. By improving our understanding of the variance in fatigue life measurements, this research helps clarify the underlying mechanisms of the mechanical fatigue process and provides a basic understanding of subchondral bone injuries in the equine fetlock joint.

SPTLC2 variants are associated with early-onset ALS and FTD due to aberrant sphingolipid synthesis.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is a devastating, incurable neurodegenerative disease. A subset of ALS patients manifests with early-onset and complex clinical phenotypes. We aimed to elucidate the genetic basis of these cases to enhance our understanding of disease etiology and facilitate the development of targeted therapies. METHODS: Our research commenced with an in-depth genetic and biochemical investigation of two specific families, each with a member diagnosed with early-onset ALS (onset age of <40 years). This involved whole-exome sequencing, trio analysis, protein structure analysis, and sphingolipid measurements. Subsequently, we expanded our analysis to 62 probands with early-onset ALS and further included 440 patients with adult-onset ALS and 1163 healthy controls to assess the prevalence of identified genetic variants. RESULTS: We identified heterozygous variants in the serine palmitoyltransferase long chain base subunit 2 (SPTLC2) gene in patients with early-onset ALS. These variants, located in a region closely adjacent to ORMDL3, bear similarities to SPTLC1 variants previously implicated in early-onset ALS. Patients with ALS carrying these SPTLC2 variants displayed elevated plasma ceramide levels, indicative of increased serine palmitoyltransferase (SPT) activity leading to sphingolipid overproduction. INTERPRETATION: Our study revealed novel SPTLC2 variants in patients with early-onset ALS exhibiting frontotemporal dementia. The combination of genetic evidence and the observed elevation in plasma ceramide levels establishes a crucial link between dysregulated sphingolipid metabolism and ALS pathogenesis. These findings expand our understanding of ALS's genetic diversity and highlight the distinct roles of gene defects within SPT subunits in its development.

Combined home and clinic-based therapy versus home-based exercise programme after distal radial fracture: a randomized controlled study.

We investigated outcomes of clinic-based hand therapy combined with a home-based exercise programme after anterior plating for distal radial fractures. A total of 102 patients were randomly assigned to one of three groups: a home-based exercise programme alone; a home-based exercise programme combined with four hand therapy sessions in the clinic; and a home-based exercise programme with seven sessions in the clinic. Mean Patient-Rated Wrist Evaluation scores at 6 weeks were significantly better for the group of patients with seven sessions in the clinic than in those with only home exercises (12 vs. 30), but the difference was no longer significant at 12 weeks. Grip strength was significantly better at 6 and 12 weeks. Combined home- and clinic-based hand therapy may facilitate an earlier return of function after anterior plating for distal radius fractures.Level of evidence: II.

Nescient helix-loop-helix 1 (Nhlh1) is a novel activating transcription factor 5 (ATF5) target gene in olfactory and vomeronasal sensory neurons in mice.

Activating transcription factor 5 (ATF5) is a transcription factor that belongs to the cAMP-response element-binding protein/ATF family and is essential for the differentiation and survival of sensory neurons in mouse olfactory organs. However, transcriptional target genes for ATF5 have yet to be identified. In the present study, chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) experiments were performed to verify ATF5 target genes in the main olfactory epithelium and vomeronasal organ in the postnatal pups. ChIP-qPCR was conducted using hemagglutinin (HA)-tagged ATF5 knock-in olfactory organs. The results obtained demonstrated that ATF5-HA fusion proteins bound to the CCAAT/enhancer-binding protein-ATF response element (CARE) site in the enhancer region of nescient helix-loop-helix 1 (Nhlh1), a transcription factor expressed in differentiating olfactory and vomeronasal sensory neurons. Nhlh1 mRNA expression was downregulated in ATF5-deficient (ATF5-/-) olfactory organs. The LIM/homeobox protein transcription factor Lhx2 co-localized with ATF5 in the nuclei of olfactory and vomeronasal sensory neurons and bound to the homeodomain site proximal to the CARE site in the Nhlh1 gene. The CARE region of the Nhlh1 gene was enriched by the active enhancer marker, acetyl-histone H3 (Lys27). The present study identified Nhlh1 as a novel target gene for ATF5 in murine olfactory organs. ATF5 may upregulate Nhlh1 expression in concert with Lhx2, thereby promoting the differentiation of olfactory and vomeronasal sensory neurons.

Monitoring ventral tail base surface temperature for fever detection in calves.

In this study, we investigated whether monitoring the ventral tail base surface temperature (ST) using a wearable wireless sensor could be effective for fever detection in calves with experimentally induced pneumonia after inoculation with Histophilus somni strain 2336. We found a significant difference in the changes in ST values between the control and H. somni-inoculated groups after 24 h of inoculation and detected fever; however, the rectal temperature showed a significant difference between the groups after 12 h of inoculation. When a significant difference in the ST between the two groups was observed, serum haptoglobin concentration and exacerbation of clinical score increased in the H. somni-inoculated group compared with those in the control group. Pneumonia was observed in the H. somni-inoculated group at necropsy, indicating that the changes in ST may reflect fever with inflammation caused by H. somni infection. Our results demonstrated that monitoring ST using a sensor attached to the ventral tail base can detect fever in calves and may be a useful and labor-saving tool for the health management of calves.

Structural Validity of the Mini-Balance Evaluation Systems Test in Individuals With Spinocerebellar Ataxia: A Rasch Analysis Study.

OBJECTIVE: To examine the structural validity of the Mini-Balance Evaluation Systems Test (Mini-BESTest) in individuals with spinocerebellar ataxia (SCA). DESIGN: Methodological research on data gathered in a cross-sectional study. A Rasch analysis was conducted (partial credit model). SETTING: Inpatients in a hospital rehabilitation setting. PARTICIPANTS: A pooled sample of patients with SCA (N=65 [total 110 data]; 23 women, 42 men; mean±SD age 63.1±9.9y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We evaluated the Mini-BESTest's category structure, unidimensionality, and measurement accuracy (0: unable to perform or requiring help to 2: normal performance). RESULTS: The Mini-BESTest rating scale fulfilled the category functioning criteria. The analysis of the standardized Rasch residuals showed the scale's unidimensionality, but there were 7 item pairs indicating local dependence. All of the items fit the underlying scale construct (dynamic balance), with the exception of item #1, "Sit to stand," which was an underfit. The Mini-BESTest demonstrated adequate reliability (person separation reliability=.87) and separated the patients into 5 strata. The item-difficulty measures ranged from -4.49 to 2.02 logits, and the person ability-item difficulty matching was very good (the mean of person ability=-.07 logits and the mean of item difficulty=.00). No floor or ceiling effects were detected. The keyform identified items with small (#11, "Walk with head turns, horizontal") and large (#3, "Stand on 1 leg") item thresholds. CONCLUSIONS: The Mini-BESTest has a unidimensional balance assessment scale with good category structure and reliability even for individuals with SCA. However, it also has some inherent shortcomings such as fit statistics, local item dependencies, and item thresholds. The results obtained when the Mini-BESTest is administered to patients with cerebellar ataxia should, thus, be interpreted cautiously.

Nationwide survey of patients with multisystem proteinopathy in Japan.

OBJECTIVE: Multisystem proteinopathy (MSP) is an inherited disorder in which protein aggregates with TAR DNA-binding protein of 43 kDa form in multiple organs. Mutations in VCP, HNRNPA2B1, HNRNPA1, SQSTM1, MATR3, and ANXA11 are causative for MSP. This study aimed to conduct a nationwide epidemiological survey based on the diagnostic criteria established by the Japan MSP study group. METHODS: We conducted a nationwide epidemiological survey by administering primary and secondary questionnaires among 6235 specialists of the Japanese Society of Neurology. RESULTS: In the primary survey, 47 patients with MSP were identified. In the secondary survey of 27 patients, inclusion body myopathy was the most common initial symptom (74.1%), followed by motor neuron disease (11.1%), frontotemporal dementia (FTD, 7.4%), and Paget's disease of bone (PDB, 7.4%), with no cases of parkinsonism. Inclusion body myopathy occurred most frequently during the entire course of the disease (81.5%), followed by motor neuron disease (25.9%), PDB (18.5%), FTD (14.8%), and parkinsonism (3.7%). Laboratory findings showed a high frequency of elevated serum creatine kinase levels and abnormalities on needle electromyography, muscle histology, brain magnetic resonance imaging, and perfusion single-photon emission computed tomography. INTERPRETATION: The low frequency of FTD and PDB may suggest that FTD and PDB may be widely underdiagnosed and undertreated in clinical practice.

Metabolomic responses to high-intensity interval exercise in equine skeletal muscle: effects of rest interval duration.

High-intensity interval training has attracted considerable attention as a time-efficient strategy for inducing physiological adaptations, but the underlying mechanisms have yet to be elucidated. By using metabolomics techniques, we investigated changes in the metabolic network responses in Thoroughbred horses to high-intensity interval exercise performed with two distinct (15 min or 2 min) rest intervals. The peak plasma lactate level was higher during high-intensity exercise with a 2 min rest duration than that with a 15 min rest duration (24.5±6.8 versus 13.3±2.7 mmol l-1). The arterial oxygen saturation was lower at the end of all exercise sessions with a 2 min rest duration than that with a 15 min rest duration. Metabolomic analysis of skeletal muscle revealed marked changes in metabolite concentrations in the first and third bouts of the 15 min rest interval conditions. In contrast, there were no metabolite concentrations or pathways that significantly changed during the third bout of exercise performed with a 2 min rest interval. Our findings suggest that the activity of each energy production system is not necessarily reflected by apparent changes in metabolite concentrations, potentially due in part to a better match between metabolite flux into and out of the pathway and cycle, as well as between metabolite production and disposal. This study provides evidence that changes in metabolite concentrations vary greatly depending on the number of repetitions and the length of rest periods between exercises, even if the exercises themselves are identical.

[Spinocerebellar ataxia 2 develop lower motor neuron involvement as an initial symptom: a case report].

A 36-year-old man has developed weakness of left thumb and atrophy of left thenar muscle and left first dorsal interosseous muscle without sensory disturbance for a year. A nerve conduction study revealed decreases in the amplitude of compound muscle action potentials and occurrence of F-waves on left medial nerve. Needle electromyography examination revealed positive sharp waves and later recruited motor units on left abductor pollicis brevis muscle. Brain MRI showed atrophy of bilateral cerebellar hemisphere. His grandmother and his two uncles have been diagnosed as spinocerebellar degeneration. After discharge, he developed bilateral lower limb ataxia. Genetic analysis showed heterozygous CAG repeat expansion (19/39) in ATXN2 gene, being diagnosed as spinocerebellar ataxia 2 (SCA2). A previous report has shown that motor neuron involvement is recognized as part of SCA2 in the same pedigree with full CAG repeat expansions in ATXN2 gene. We here report the patient with lower motor neuron involvement as an initial symptom of SCA2.

Inhibition of Heat Shock Protein 90 Lowered Intraocular Pressure without Affecting the Production of Aqueous Humor in Rabbits.

INTRODUCTION: Heat shock protein (Hsp) 90 is one of the most abundant proteins in unstressed cells and regulates stability and functional maintenance of client proteins. In ocular tissue, Hsp90 is widely expressed in the cornea and retina and has multiple roles in these tissues. The expression of HSPs was induced in the retinas of glaucomatous patients and laser-induced glaucoma in monkey while their mechanisms remain to be elucidated. For this reason, we tried to elucidate the role of Hsp90 in intraocular pressure (IOP) regulation in rabbits. METHODS: IOP was measured by a pneumatonometer before and after intracameral injection of Hsp90 inhibitors. The aqueous flow rate was measured by fluorophotometry. Trans-epithelial electrical resistance was measured in primary human trabecular meshwork cells. RESULTS: 17-AAG, a specific Hsp90 inhibitor, significantly lowered IOP at concentrations of more than 30 µm in normotensive rabbits. Other Hsp90 inhibitors also significantly lowered IOP in normotensive rabbits at a dose of 100 µm. No reduction of aqueous humor production was observed by injection of 17-AAG in rabbits. Topical administration of pilocarpine tended to attenuate the IOP-lowering effects induced by the Hsp90 inhibitor. No reduction of trans-epithelial electrical resistance was observed by inhibition of Hsp90 in culture cells. CONCLUSIONS: These results indicated that intraocular Hsp90 regulates IOP, and the inhibition of Hsp90 by Hsp90 inhibitor decreases IOP without affecting aqueous humor production in rabbits. Further research in elucidating the mechanism of Hsp90 inhibitors will result in a better understanding of the role of Hsp90 in the regulation of IOP.

Writer's Cramps as an Initial Symptom of Spinocerebellar Ataxia Type 14: A Case Report.

Spinocerebellar ataxia type 14 (SCA14) is a rare form of autosomal dominant cerebellar ataxia caused by mutations in PRKCG. We herein report a case of SCA14 presenting with writer's cramp that predated the onset of progressive ataxia by four years. A 47-year-old Japanese woman had an 11-year history of writer's cramps, followed by unsteadiness. Whole-exome sequencing revealed a heterozygous mutation in PRKCG (p.C142S), leading to an SCA14 diagnosis. Therefore, writer's cramp might be a characteristic extracerebellar sign of SCA14 and can precede the onset of cerebellar ataxia.

Analysis of the Relationship Between Muscle Tones and Abnormal Postures in a Computational Model.

Patients with Parkinson's disease (PD), a neurodegenerative disorder, exhibit a characteristic posture known as a forward flexed posture. Increased muscle tone is suggested as a possible cause of this abnormal posture. For further analysis, it is necessary to measure muscle tone, but the experimental measurement of muscle tone during standing is challenging. The aim of this study was to examine the hypothesis that "In patients with PD, abnormal postures are those with a small sway at increased muscle tones" using a computational model. The muscle tones of various magnitudes were estimated using the computational model and standing data of patients with PD. The postures with small sway at the estimated muscle tones were then calculated through an optimization method. The postures and sway calculated using the computational model were compared to those of patients with PD. The results showed that the differences in posture and sway between the simulation and experimental results were small at higher muscle tones compared to those considered plausible in healthy subjects by the simulations. This simulation result indicates that the reproduced sway at high muscle tones is similar to that of actual patients with PD and that the reproduced postures with small sway locally at high muscle tones in the simulations are similar to those of patients with PD. The result is consistent with the hypothesis, reinforcing the hypothesis.Clinical relevance- This study implies that improving the increased muscle tone in patients with PD may lead to an improved abnormal posture.

Exploring the Potential of the Corpus Callosum Area as a Predictive Marker for Impaired Information Processing in Multiple Sclerosis.

Early cognitive impairment (CI) detection is crucial in multiple sclerosis (MS). However, it can progress silently regardless of relapse activity and reach an advanced stage. We aimed to determine whether the corpus callosum area (CCA) is a sensitive and feasible marker for CI in MS compared to other neuroimaging markers. We assessed cognitive function in 77 MS patients using the Symbol Digit Modalities Test, Paced Auditory Serial Additions Task, Wechsler Adult Intelligence Scale-IV, and Wechsler Memory Scale-Revised. The neuroimaging markers included manually measured CCA, two diffusion tensor imaging markers, and nine volumetric measurements. Apart from volumes of the hippocampus and cerebellum, ten markers showed a significant correlation with all neuropsychological tests and significant differences between the groups. The normalized CCA demonstrated a moderate-to-strong correlation with all neuropsychological tests and successfully differentiated between the CI and cognitively normal groups with 80% sensitivity and 83% specificity. The marker had a large area under the curve and a high Youden index (0.82 and 0.63, respectively) and comparability with established cognitive markers. Therefore, the normalized CCA may serve as a reliable marker for CI in MS and can be easily implemented in clinical practice, providing a supportive diagnostic tool for CI in MS.

Effectiveness of Minitracheostomy After Extubation in Patients with Pneumonia at High Risk of Reintubation: A Case Series.

Introduction: Minitracheostomy involves the percutaneous insertion of a 4-mm-diameter cricothyroidotomy tube for tracheal suctioning to facilitate the clearance of airway secretions. The advantage of using the minitracheostomy is in the clearance of secretions, however data on their usefulness for respiratory failure after extubation is limited. Aim of the study: We aimed to assess the use of minitracheostomy for patients with challenging extubation caused by significant sputum. Material and Methods: We conducted a retrospective analysis of consecutive case series. We analyzed the data of 31 patients with pneumonia. After minitracheostomy, the primary endpoints of reintubation within 72 hours and clinical effects, including mortality, length of intensive care unit (ICU), or hospital stay, were assessed. The successful extubation group included patients who did not require reintubation within 72 hours. Conversely, the reintubation group consisted of patients mandating reestablishment of intubation within 72 hours. Results: Among those who underwent minitracheostomy after extubation, 22 (71%) underwent successful extubation and 9 underwent reintubation (reintubation rate: 29%). The in-hospital mortality rates after 30 days were 18.2% in the successful extubation group and 22.2% in the reintubation group. The ICU and hospital lengths of stay were 11 days (interquartile range: 8-14.3 days) and 23 days (interquartile range: 15.5-41 days), respectively, in the successful extubation group; they were 14 days (interquartile range: 11-18.5 days) and 30 days (interquartile range: 16-45.5 days), respectively, in the reintubation group. Conclusions: The prophylactic use of minitracheostomy may be an option as a means of reducing reintubation in patients with pneumonia who are at very high risk of reintubation.

Brain Abnormalities in Becker Muscular Dystrophy: Evaluation by Voxel-Based DTI and Morphometric Analysis.

BACKGROUND AND PURPOSE: Although various neuropsychological problems in Becker muscular dystrophy have attracted attention, there have been few related neuroimaging studies. We investigated brain abnormalities in patients with Becker muscular dystrophy using 3D T1WI and DTI. MATERIALS AND METHODS: MR images were obtained for 30 male patients and 30 age-matched healthy male controls. We classified patients into Dp140+ and Dp140- subgroups based on their predicted dystrophin Dp140 isoform expression and performed voxel-based comparisons of gray and white matter volumes and DTI metrics among the patients, patient subgroups, and controls. ROI-based DTI analyses were also performed. RESULTS: Significantly decreased fractional anisotropy was observed in the left planum temporale and right superior parietal lobule compared between the Becker muscular dystrophy and control groups. In the Dp140- subgroup, decreased fractional anisotropy was observed in the left planum temporale, but no significant changes were seen in the Dp140+ subgroup. The ROI-based analysis obtained the same results. No significant differences were evident in the gray or white matter volumes or the DTI metrics other than fractional anisotropy between the groups. CONCLUSIONS: A DTI metric analysis is useful to detect white-matter microstructural abnormalities in Becker muscular dystrophy that may be affected by the Dp140 isoform expression.

Physiological and skeletal muscle responses to high-intensity interval exercise in Thoroughbred horses.

Introduction: The purpose of this study was to determine whether acute high-intensity interval exercise or sprint interval exercise induces greater physiological and skeletal muscle responses compared to moderate-intensity continuous exercise in horses. Methods: In a randomized crossover design, eight trained Thoroughbred horses performed three treadmill exercise protocols consisting of moderate-intensity continuous exercise (6 min at 70% VO2max; MICT), high-intensity interval exercise (6 × 30 s at 100% VO2max; HIIT), and sprint interval exercise (6 × 15 s at 120% VO2max; SIT). Arterial blood samples were collected to measure blood gas variables and plasma lactate concentration. Biopsy samples were obtained from the gluteus medius muscle before, immediately after, 4 h, and 24 h after exercise for biochemical analysis, western blotting and real-time RT-PCR. Effects of time and exercise protocol were analyzed using mixed models (p < 0.05). Results: Heart rate and plasma lactate concentration at the end of exercise were higher in HIIT and SIT than those in MICT (heart rate, HIIT vs. MICT, p = 0.0005; SIT vs. MICT, p = 0.0015; lactate, HIIT vs. MICT, p = 0.0014; SIT vs. MICT, p = 0.0003). Arterial O2 saturation and arterial pH in HIIT and SIT were lower compared with MICT (SaO2, HIIT vs. MICT, p = 0.0035; SIT vs. MICT, p = 0.0265; pH, HIIT vs. MICT, p = 0.0011; SIT vs. MICT, p = 0.0023). Muscle glycogen content decreased significantly in HIIT (p = 0.0004) and SIT (p = 0.0016) immediately after exercise, but not in MICT (p = 0.19). Phosphorylation of AMP-activated protein kinase (AMPK) in HIIT showed a significant increase immediately after exercise (p = 0.014), but the increase was not significant in MICT (p = 0.13) and SIT (p = 0.39). At 4 h after exercise, peroxisome proliferator-activated receptor γ co-activator-1α mRNA increased in HIIT (p = 0.0027) and SIT (p = 0.0019) and vascular endothelial growth factor mRNA increased in SIT (p = 0.0002). Discussion: Despite an equal run distance, HIIT and SIT cause more severe arterial hypoxemia and lactic acidosis compared with MICT. In addition, HIIT activates the AMPK signaling cascade, and HIIT and SIT elevate mitochondrial biogenesis and angiogenesis, whereas MICT did not induce any significant changes to these signaling pathways.

Analysis of in vivo humeral rotation of reverse total shoulder arthroplasty patients during shoulder abduction on the scapular plane with a load.

BACKGROUND: Few studies have investigated the kinematics after reverse total shoulder arthroplasty (RTSA). This study aimed to compare the shoulder kinematics in RTSA patients during shoulder abduction on the scapular plane with and without a load and yield information regarding the function of stabilizing the joints against gravity for the functional assessment of the shoulder after RTSA, which could lead to changes in postoperative rehabilitation treatment. METHODS: Twenty RTSA patients (7 men, 13 women; mean age: 78.1 [64-90] years) were examined. First, active shoulder abduction in the scapular plane was captured using single-plane fluoroscopic X-ray images. Imaging was performed by stipulating that one shoulder abduction cycle should be completed in 6 s. Two trials were conducted: one under a load equivalent to 2% of body weight and one without a load. Next, a three-dimensional (3D) model of each humeral and scapular component was matched to the silhouette of the fluoroscopic image to estimate the 3D dynamics. By using the 3D dynamic model obtained, the kinematics of the glenosphere and humeral implant were calculated relative to the shoulder abduction angle on the scapular plane and were compared between groups with and without a load. A one-way analysis of variance and a post hoc paired t-test with a statistical significance level of 0.05 were performed. RESULTS: The humeral internal rotation decreased with a load at shoulder abduction between 40° and 90° on the scapular plane (P < 0.01, effect size: 0.15). No significant differences in scapular upward rotation (P = 0.57, effect size: 0.022), external rotation (P = 0.83, effect size: 0.0083) and posterior tilting (P = 0.74, effect size: 0.013) were observed between groups with and without a load. The main effect was not observed with and without a load (P = 0.86, effect size: 0.0072). However, the scapulohumeral rhythm was significantly greater without a load during shoulder joint abduction between 40° and 60° on the scapular plane. CONCLUSION: In RTSA patients, the glenohumeral joint was less internally rotated, and the scapulohumeral rhythm decreased under loaded conditions. It was stabilized against the load through the mechanical advantage of the deltoid muscle and other muscles.