Limb Underloading in Walking Transmits Less Dynamic Knee Joint Contact Forces after Anterior Cruciate Ligament Reconstruction.

Introduction: Individuals with anterior cruciate ligament reconstruction (ACLR) often walk with a less dynamic vertical ground reaction force (vGRF), exemplified by a reduced first peak vGRF and elevated midstance vGRF compared to uninjured controls. However, the mechanism by which altered limb loading affects actual tibial plateau contact forces during walking remains unclear.

Methods: Our purpose was to use musculoskeletal simulation to evaluate the effects of first peak vertical ground reaction force (vGRF) biofeedback on bilateral tibiofemoral contact forces relevant to the development of post-traumatic osteoarthritis (OA) in 20 individuals with ACLR.

The Effect of Shoe Insole Stiffness Modifications on Walking Performance in Older Adults: A Feasibility Study.

Shoes or insoles embedded with carbon fiber materials to increase longitudinal stiffness have been shown to enhance running and walking performance in elite runners, and younger adults, respectively. It is unclear, however, if such stiffness modifications can translate to enhanced mobility in older adults who typically walk with greater metabolic cost of transport compared to younger adults. Here, we sought to test whether adding footwear stiffness via carbon fiber insoles could improve walking outcomes (eg, distance traveled and metabolic cost of transport) in older adults during the 6-minute walk test.

Conceptual modeling of structural malalignments and ankle joint contact forces during walking.

Background: Structural malalignments, such as talar malalignments and hindfoot varus, are hypothesized to contribute to early ankle joint degeneration by altering joint contact force (JCF). These malalignments, common in individuals with chronic ankle instability (CAI), can modify the articular geometry of the ankle joint, potentially leading to abnormal joint loading patterns. This study leverages musculoskeletal modeling and simulation to conceptualize the effects of increasing severity of these malalignments on ankle JCF during walking.

The effects of age and task demand on dynamic mean ankle moment arm during walking.

Background: Older adults walk with a diminished foot and ankle push-off compared to younger adults and this difference may be a target for assistive devices. Dynamic mean ankle moment arm (DMAMA) is an aggregate measure of foot and ankle control that varies in younger adults across walking speeds and inclines.

Research Question: Does age affect DMAMA across a range of walking tasks designed to challenge power output from the ankle and foot?

Methods: We enrolled 12 healthy younger adults and 10 healthy older adults.

Questionnaires of self-perception poorly correlate with instability elicited by walking balance perturbations.

Rehabilitation to prevent falls should not only directly address intrinsic and extrinsic factors, but also the neuropsychology of falls to promote safe and independent mobility in our aging population. The purpose of this study was to determine the relation between falls self-efficacy and objective responses to a series of walking balance perturbations. 29 healthy younger adults and 28 older adults completed four experimental trials, including unperturbed walking and walking while responding to three perturbations: mediolateral optical flow, treadmill-induced slips, and lateral waist-pulls; and three self-reported questionnaires: Activity-specific Balance Confidence, Falls Efficacy Scale, and the Fear of Falling Questionnaire-Revised.

The aging Achilles tendon: model-predicted changes in calf muscle neuromechanics.

Forward propulsion depends on the forces generated by the triceps surae muscles and transmitted through the muscles' subtendons, which merge and twist to form the Achilles tendon (AT). As people age, the AT may undergo structural changes that could alter the subtendons' ability to transmit forces or function with some independence; prominent changes include increased tendon compliance and a proliferation of interfascicular adhesions compared to younger tendon. However, the effects of age-related changes on the subtendons are difficult to isolate in vivo.

Reduced Achilles tendon stiffness in aging associates with higher metabolic cost of walking.

The mechanisms responsible for increased metabolic cost of walking in older adults are poorly understood. We recently proposed a theoretical premise by which age-related reductions in Achilles tendon stiffness (k) can disrupt the neuromechanics of calf muscle force production and contribute to faster rates of oxygen consumption during walking. The purpose of this study was to objectively evaluate this premise.

Foot-Ankle Mechanical Transmission: Age Effects and the Relation to Ankle Push-Off During Walking.

Older adults walk with less push-off power than younger adults. Principally attributed to plantar flexor dysfunction, growing evidence implicates interactions between the foot and ankle as critical for generating effective push-off. Our purposes were to measure age effects on foot-ankle mechanical transmission (FAMT, ie, the ratio between metatarsal phalangeal extension and medial gastrocnemius fascicle length change), and its association with ankle push-off during walking.

BCAS1-positive oligodendrocytes enable efficient cortical remyelination in multiple sclerosis.

Remyelination is a crucial regenerative process in demyelinating diseases, limiting persisting damage to the central nervous system (CNS). It restores saltatory nerve conduction and ensures trophic support of axons. In multiple sclerosis (MS) patients, remyelination has been observed in both white and grey matter and found to be more efficient in the cortex.

Expert perspectives on ECCOR for acute hypoxemic respiratory failure: consensus of a 2022 European roundtable meeting.

Background: By controlling hypercapnia, respiratory acidosis, and associated consequences, extracorporeal CO removal (ECCOR) has the potential to facilitate ultra-protective lung ventilation (UPLV) strategies and to decrease injury from mechanical ventilation. We convened a meeting of European intensivists and nephrologists and used a modified Delphi process to provide updated insights into the role of ECCOR in acute respiratory distress syndrome (ARDS) and to identify recommendations for a future randomized controlled trial.

Results: The group agreed that lung protective ventilation and UPLV should have distinct definitions, with UPLV primarily defined by a tidal volume (V) of 4-6 mL/kg predicted body weight with a driving pressure (ΔP) ≤ 14-15 cmHO.

Peak vertical ground reaction force used to identify sub-groups of individuals with differing biomechanical gait profiles post-anterior cruciate ligament reconstruction.

Lesser peak vertical ground reaction force (vGRF) has been widely reported among individuals with anterior cruciate ligament reconstruction (ACLR). Peak vGRF remains less than uninjured controls and relatively stable during the first year following ACLR. However, it is unknown whether there are subgroups of individuals exhibiting consistently greater peak vGRF in the first 6-months following ACLR and if individuals with consistently greater peak vGRF exhibit kinematic and kinetic gait differences compared to individuals with low vGRF.

An outbreak of renal failure in asian dogs due to s-triazine adulteration of pet food raw material: Analysis of unique, green kidney stones formed as a result.

Renoliths were removed at necropsy from dogs that had died from acute kidney injury in Asia in 2004 and submitted to our laboratories for analysis including elemental composition, mass spectrometry, and nuclear magnetic resonance spectroscopy. The presence of a mixed s-triazine matrix comprising melamine, cyanuric acid, and ammelide, but no detectable ammeline, was found in the stone samples we analyzed. The unusual and unique green coloration of these stones was determined to be due to the presence of biliverdin.

Persistent cytopenias after anti-BCMA CAR T-cell therapy are associated with reduced hematopoietic activity in posttreatment bone marrows.

Objectives: We attempt to analyze bone marrow findings and correlation with cytopenia(s) after anti-B-cell maturation antigen (BCMA) chimeric antigen receptor (CAR) T-cell infusion in this study.

Methods: Relevant clinicopathologic data, including complete blood counts, neutrophil counts, relevant therapy history, and pre- and posttherapy bone marrow evaluations, were studied in 12 patients who received anti-BCMA CAR T-cell therapy.

Results: Bone marrow findings after CAR T-cell therapy were available in 6 of 12 cases, 3 of which showed markedly hypocellular marrow with either markedly reduced or essentially absent hematopoiesis.

T cell-mediated microglial activation triggers myelin pathology in a mouse model of amyloidosis.

Age-related myelin damage induces inflammatory responses, yet its involvement in Alzheimer's disease remains uncertain, despite age being a major risk factor. Using a mouse model of Alzheimer's disease, we found that amyloidosis itself triggers age-related oligodendrocyte and myelin damage. Mechanistically, CD8 T cells promote the progressive accumulation of abnormally interferon-activated microglia that display myelin-damaging activity.

The impact of infused red blood cell volume on major and bidirectional ABO-mismatched bone marrow transplantation.

Background Aims: ABO incompatibility does not hinder bone marrow transplantation (BMT), but it has been associated with worse outcomes and additional adverse events. This study aimed to verify the impact of incompatible red blood cells (iRBCs) in allogeneic BMT and to determine a safe number of iRBCs to be infused.

Methods: We compared ABO-incompatible (iABO) allogeneic BMT (n = 42) with ABO-compatible allogeneic BMT (n = 44) and evaluated the impact of the number of infused iRBCs on outcomes and adverse events.

Effect of sensor number and location on accelerometry-based vertical ground reaction force estimation during walking.

Knee osteoarthritis is a major cause of global disability and is a major cost for the healthcare system. Lower extremity loading is a determinant of knee osteoarthritis onset and progression; however, technology that assists rehabilitative clinicians in optimizing key metrics of lower extremity loading is significantly limited. The peak vertical component of the ground reaction force (vGRF) in the first 50% of stance is highly associated with biological and patient-reported outcomes linked to knee osteoarthritis symptoms.

Neuropathological assessment of the olfactory bulb and tract in individuals with COVID-19.

The majority of patients with Parkinson disease (PD) experience a loss in their sense of smell and accumulate insoluble α-synuclein aggregates in their olfactory bulbs (OB). Subjects affected by a SARS-CoV-2-linked illness (COVID-19) also frequently experience hyposmia. We previously postulated that microglial activation as well as α-synuclein and tau misprocessing can occur during host responses following microbial encounters.

The effects of plantarflexor weakness and reduced tendon stiffness with aging on gait stability.

Falls among older adults are a costly public health concern. Such falls can be precipitated by balance disturbances, after which a recovery strategy requiring rapid, high force outputs is necessary. Sarcopenia among older adults likely diminishes their ability to produce the forces necessary to arrest gait instability.

Visual feedback improves propulsive force generation during treadmill walking in people with Parkinson disease.

Persons with Parkinson's disease experience gait alterations, such as reduced step length. Gait dysfunction is a significant research priority as the current treatments targeting gait impairment are limited. This study aimed to investigate the effects of visual biofeedback on propulsive force during treadmill walking in persons with Parkinson's.

Bifurcation of Excited-State Population Leads to Anti-Kasha Luminescence in a Disulfide-Decorated Organometallic Rhenium Photosensitizer.

We report a rhenium diimine photosensitizer equipped with a peripheral disulfide unit on one of the bipyridine ligands, [Re(CO)(bpy)(bpy)] (, bpy = 2,2'-bipyridine, bpy = [1,2]dithiino[3,4-:6,5-']dipyridine), showing anti-Kasha luminescence. Steady-state and ultrafast time-resolved spectroscopies complemented by nonadiabatic dynamics simulations are used to disclose its excited-state dynamics. The calculations show that after intersystem crossing the complex evolves to two different triplet minima: a (bpy)-ligand-centered excited state (LC) lying at lower energy and a metal-to-(bpy)-ligand charge transfer (MLCT) state at higher energy, with relative yields of 90% and 10%, respectively.