Sustained Limb-Level Loading: A Ground Reaction Force Phenotype Common to Individuals at High Risk for and Those With Knee Osteoarthritis.

Objective: The objective of this study was to compare the vertical (vGRF), anterior-posterior (apGRF), and medial-lateral (mlGRF) ground reaction force (GRF) profiles throughout the stance phase of gait (1) between individuals 6 to 12 months post-anterior cruciate ligament reconstruction (ACLR) and uninjured matched controls and (2) between ACLR and individuals with differing radiographic severities of knee osteoarthritis (KOA), defined as Kellgren and Lawrence (KL) grades KL2, KL3, and KL4.

Methods: A total of 196 participants were included in this retrospective cross-sectional analysis. Gait biomechanics were collected from individuals 6 to 12 months post-ACLR (n = 36), uninjured controls matched to the ACLR group (n = 36), and individuals with KL2 (n = 31), KL3 (n = 67), and KL4 osteoarthritis (OA) (n = 26).

Association of Jump-Landing Biomechanics With Tibiofemoral Articular Cartilage Composition 12 Months After ACL Reconstruction.

Background: Excessively high joint loading during dynamic movements may negatively influence articular cartilage health and contribute to the development of posttraumatic osteoarthritis after anterior cruciate ligament reconstruction (ACLR). Little is known regarding the link between aberrant jump-landing biomechanics and articular cartilage health after ACLR.

Purpose/hypothesis: The purpose of this study was to determine the associations between jump-landing biomechanics and tibiofemoral articular cartilage composition measured using T1ρ magnetic resonance imaging (MRI) relaxation times 12 months postoperatively.

Changes in Infrapatellar Fat Pad Volume 6 to 12 Months After Anterior Cruciate Ligament Reconstruction and Associations With Patient-Reported Knee Function.

Context: Hypertrophy of the infrapatellar fat pad (IFP) in idiopathic knee osteoarthritis has been linked to deleterious synovial changes and joint pain related to mechanical tissue impingement. Yet little is known regarding the IFP's volumetric changes after anterior cruciate ligament reconstruction (ACLR).

Objectives: To examine changes in IFP volume between 6 and 12 months after ACLR and determine associations between patient-reported outcomes and IFP volume at each time point as well as the volume change over time.

In Vivo Compositional Changes in the Articular Cartilage of the Patellofemoral Joint Following Anterior Cruciate Ligament Reconstruction.

Objective: To compare T1ρ relaxation times of the medial and lateral regions of the patella and femoral trochlea at 6 and 12 months following anterior cruciate ligament reconstruction (ACLR) on the ACLR and contralateral extremity. Greater T1ρ relaxation times are associated with a lower proteoglycan density of articular cartilage.

Methods: This study involved 20 individuals (11 males, 9 females; mean ± SD age 22 ± 3.

Using TENS to Enhance Therapeutic Exercise in Individuals with Knee Osteoarthritis.

Unlabelled: Transcutaneous electrical nerve stimulation (TENS) facilitates quadriceps voluntary activation in experimental settings. Augmenting therapeutic exercise (TE) with TENS may enhance the benefits of TE in individuals with knee osteoarthritis (KOA) and quadriceps voluntary activation failure (QVAF).

Purpose: This study aimed to determine the effect of TENS + TE on patient-reported function, quadriceps strength, and voluntary activation, as well as physical performance compared with sham TENS + TE (Sham) and TE alone in individuals with symptomatic KOA and QVAF.

Bilateral Gait 6 and 12 Months Post-Anterior Cruciate Ligament Reconstruction Compared with Controls.

Purpose: To compare gait biomechanics throughout stance phase 6 and 12 months after unilateral anterior cruciate ligament reconstruction (ACLR) between ACLR and contralateral limbs and compared with controls.

Methods: Vertical ground reaction force (vGRF), knee flexion angle (KFA), and internal knee extension moment (KEM) were collected bilaterally 6 and 12 months post-ACLR in 30 individuals (50% female, 22 ± 3 yr, body mass index = 23.8 ± 2.

Assessing Step Count-Dependent Changes in Femoral Articular Cartilage Using Ultrasound.

Objectives: To evaluate changes in the femoral cartilage cross-sectional area (CSA) measured with ultrasound (US) between baseline and 1000, 2000, 3000, 4000, and 5000 steps of walking on a treadmill.

Methods: Forty-one healthy individuals completed a single testing session. Participants rested with their knees extended on a plinth for 45 minutes to unload the femoral cartilage.

Effects of a knee valgus unloader brace on medial femoral articular cartilage deformation following walking in varus-aligned individuals.

Background: Knee varus alignment may increase loading in the medial tibiofemoral compartment, which can increase strain on the articular cartilage. Knee valgus unloader braces seek to reduce loading through the medial femoral compartment, but their effects on cartilage characteristics during dynamic tasks have not been evaluated.

Objective: To determine the effects of a knee valgus unloader brace on medial femoral articular cartilage deformation following a single 5000-step walking protocol in individuals with varus-knee alignment.

Quadriceps weakness associates with greater T1ρ relaxation time in the medial femoral articular cartilage 6 months following anterior cruciate ligament reconstruction.

Purpose: Quadriceps weakness following anterior cruciate ligament reconstruction (ACLR) is linked to decreased patient-reported function, altered lower extremity biomechanics and tibiofemoral joint space narrowing. It remains unknown if quadriceps weakness is associated with early deleterious changes to femoral cartilage composition that are suggestive of posttraumatic osteoarthritis development. The purpose of the cross-sectional study was to determine if quadriceps strength was associated with T1ρ relaxation times, a marker of proteoglycan density, of the articular cartilage in the medial and lateral femoral condyles 6 months following ACLR.

Gait Mechanics and T1ρ MRI of Tibiofemoral Cartilage 6 Months after ACL Reconstruction.

Purpose: Aberrant walking biomechanics after anterior cruciate ligament reconstruction (ACLR) are hypothesized to be associated with deleterious changes in knee cartilage. T1ρ magnetic resonance imaging (MRI) is sensitive to decreased proteoglycan density of cartilage. Our purpose was to determine associations between T1ρ MRI interlimb ratios (ILR) and walking biomechanics 6 months after ACLR.

Walking Ground Reaction Force Post-ACL Reconstruction: Analysis of Time and Symptoms.

Purpose: The association between lower-extremity loading and clinically relevant knee symptoms at different time points after anterior cruciate ligament reconstruction (ACLR) is unclear. Vertical ground reaction force (vGRF) from walking was compared between individuals with and without clinically relevant knee symptoms in three cohorts: <12 months post-ACLR, 12-24 months post-ACLR, and >24 months post-ACLR.

Methods: One hundred twenty-eight individuals with unilateral ACLR were classified as symptomatic or asymptomatic, based on previously defined cutoff values for the Knee Osteoarthritis and Injury Outcome Score (<12 months post-ACLR [symptomatic n = 28, asymptomatic n = 24]; 12-24 months post-ACLR [symptomatic n = 15, asymptomatic n = 15], and >24 months post-ACLR [symptomatic, n = 13; asymptomatic, n = 33]).

Walking gait asymmetries 6 months following anterior cruciate ligament reconstruction predict 12-month patient-reported outcomes.

The study sought to determine the association between gait biomechanics (vertical ground reaction force [vGRF], vGRF loading rate [vGRF-LR]) collected 6 months following anterior cruciate ligament reconstruction (ACLR) with patient-reported outcomes at 12 months following ACLR. Walking gait biomechanics and all subsections of the Knee Injury and Osteoarthritis Outcomes Score (KOOS) were collected at 6 and 12 months following ACLR, respectively, in 25 individuals with a unilateral ACLR. Peak vGRF and peak instantaneous vGRF-LR were extracted from the first 50% of the stance phase.

Peak knee biomechanics and limb symmetry following unilateral anterior cruciate ligament reconstruction: Associations of walking gait and jump-landing outcomes.

Background: Aberrant walking-gait and jump-landing biomechanics may influence the development of post-traumatic osteoarthritis and increase the risk of a second anterior cruciate ligament injury, respectively. It remains unknown if individuals who demonstrate altered walking-gait biomechanics demonstrate similar altered biomechanics during jump-landing. Our aim was to determine associations in peak knee biomechanics and limb-symmetry indices between walking-gait and jump-landing tasks in individuals with a unilateral anterior cruciate ligament reconstruction.

Associations Between Slower Walking Speed and T1ρ Magnetic Resonance Imaging of Femoral Cartilage Following Anterior Cruciate Ligament Reconstruction.

Objective: To determine whether walking speed, collected at 6 and 12 months following anterior cruciate ligament reconstruction (ACLR), is associated with inter-extremity differences in proteoglycan density, measured via T1ρ magnetic resonance imaging, in tibiofemoral articular cartilage 12 months following ACLR.

Methods: Twenty-one individuals with a unilateral patellar-tendon autograft ACLR (10 women and 11 men, mean ± SD age 23.9 ± 2.

Risk stratification following complex PCI: clinical versus anatomical risk stratification including "post PCI residual SYNTAX-score" as quantification of incomplete revascularization.

Background: EuroSCORE and completeness of revascularization predicts long-term survival after multivessel PCI (MV-PCI). The SYNTAX-Score has also been proposed to predict clinical outcome. The prognostic impact of these scores to predict long-term survival after PCI has not yet been compared.

A switch in pathogenic mechanism in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis in IFN-γ-inducible lysosomal thiol reductase-free mice.

IFN-γ-inducible lysosomal thiol reductase (GILT) is an enzyme located in the Lamp-2-positive compartments of APC. GILT(-/-) mice are phenotypically normal, but their T cells exhibit reduced proliferation to several exogenously administered Ags that include cysteine residues and disulfide bonds. We undertook the present studies to determine if GILT(-/-) mice would process exogenously administered myelin oligodendrocyte glycoprotein (MOG), which contains disulfide bonds, to generate experimental autoimmune encephalomyelitis (EAE) to the endogenous protein.

Microglial cystatin F expression is a sensitive indicator for ongoing demyelination with concurrent remyelination.

Demyelination coincides with numerous changes of gene expression in the central nervous system (CNS). Cystatin F, which is a papain-like lysosomal cysteine proteinase inhibitor that is normally expressed by immune cells and not in the brain, is massively induced in the CNS during acute demyelination. We found that microglia, which are monocyte/macrophage-lineage cells in the CNS, express cystatin F only during demyelination.

Myelin protein composition is altered in mice lacking either sulfated or both sulfated and non-sulfated galactolipids.

Myelin is highly enriched in galactocerebroside (GalCer) and its sulfated form sulfatide. Mice, unable to synthesize GalCer and sulfatide (CGT(null)) or sulfatide alone (CST(null)), exhibit disorganized paranodal structures and progressive dysmyelination. To obtain insights into the molecular mechanisms underlying these defects, we examined myelin composition of these mutants by two-dimensional differential fluorescence intensity gel electrophoresis proteomic approach and immunoblotting.

Human myelin proteome and comparative analysis with mouse myelin.

Myelin, formed by oligodendrocytes (OLs) in the CNS, is critical for axonal functions, and its damage leads to debilitating neurological disorders such as multiple sclerosis. Understanding the molecular mechanisms of myelination and the pathogenesis of human myelin disease has been limited partly by the relative lack of identification and functional characterization of the repertoire of human myelin proteins. Here, we present a large-scale analysis of the myelin proteome, using the shotgun approach of 1-dimensional PAGE and liquid chromatography/tandem MS.

Role for Rab3a in oligodendrocyte morphological differentiation.

Rab3a, a small GTPase important for exocytosis, is uniquely up-regulated as oligodendrocytes enter terminal differentiation and initiate myelin biosynthesis. In this study, we analyze the role of this protein in oligodendrocyte morphological differentiation by using Rab3a overexpression and siRNAi-mediated Rab3a silencing. We found that Rab3a silencing delayed mature oligodendrocyte morphological differentiation but did not interfere with lineage progression of OL progenitors; this is consistent with the high levels of Rab3a expressed by mature oligodendrocytes compared with progenitor cells.

The Reliability and Validity of a Spanish Translated Version of the Gifted Rating Scales.

This study was a preliminary examination of the psychometric properties of a newly developed Spanish translated version of the . Data was collected from elementary and middle schools in northeastern Puerto Rico. Thirty teachers independently rated 153 students using the GRS-S Spanish Form.

Microglial Fc receptors mediate physiological changes resulting from antibody cross-linking of myelin oligodendrocyte glycoprotein.

Antibodies to myelin oligodendrocyte glycoprotein (MOG) have been implicated in Multiple Sclerosis demyelination through activation of complement and/or macrophage-effector processes. We presented a novel mechanism, whereby MOG on oligodendrocytes, when cross-linked with anti-MOG and secondary antibody resulted in its repartitioning into lipid rafts, and changes in protein phosphorylation and morphology. Here, we show that similar events occur when anti-MOG is cross-linked with Fc receptors (FcRs) present on microglia but not with complement.

Validation of the Gifted Rating Scales-School Form in China.

The Gifted Rating Scales-School Form (GRS-S), a teacher-completed rating scale, is designed to identify five types of giftedness and motivation. This study examines the reliability and validity of a Chinese-translated version of the GRS-S with a sample of Chinese elementary and middle school students ( = 499). The Chinese GRSS was found to have high internal consistency.

The Gifted Rating Scales-School Form: A Validation Study Based on Age, Gender, and Race.

This study examined the internal consistency and validity of a new rating scale to identify gifted students, the Gifted Rating Scales-School Form (GRS-S). The study explored the effect of gender, race/ethnicity, age, and rater familiarity on GRS-S ratings. One hundred twenty-two students in first to eighth grade from elementary and middle schools in the southeastern United States participated in the investigation.