Coronavirus disease 2019 (COVID-19) is an emerging pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although majority of patients who become infected with SARS-CoV-2 are asymptomatic or have mild symptoms, some develop symptoms that can permanently detract from their quality life. closely related to SARS-CoV-1, which causes (SARS). Both viruses infect system, and there direct indirect effects this infection on multiple organ systems, including...

Advanced age is associated with increases in muscle passive stiffness, but the contributors to changes remain unclear. Our purpose was determine relative contributions of fibers and extracellular matrix (ECM) stiffness both adult old animals. Passive mechanical properties were determined for isolated individual bundles that included their ECM, obtained from tibialis anterior muscles (8-12 mo old) (28-30 mice. Maximum tangent moduli not different at any sarcomere length tested. In contrast,...

Tendons play a significant role in the modulation of forces transmitted between bones and skeletal muscles consequently protect muscle fibers from contraction-induced, or high-strain, injuries. Myostatin (GDF-8) is negative regulator mass. Inhibition myostatin not only increases mass maximum isometric force muscles, but also susceptibility to contraction-induced injury. We hypothesized that would regulate morphology mechanical properties tendons. The expression receptors ACVR2B ACVRB was...

Transforming growth factor-beta (TGF-β) is a well-known regulator of fibrosis and inflammation in many tissues. During embryonic development, TGF-β signaling induces expression the transcription factor scleraxis, which promotes fibroblast proliferation collagen synthesis tendons. In skeletal muscle, has been shown to induce atrophy fibrosis, but effect on muscle contractility scleraxis atrogin-1, an important atrophy, were not known.We treated muscles from mice with measured force...

Abstract Scleraxis is a basic helix–loop–helix transcription factor that plays central role in promoting fibroblast proliferation and matrix synthesis during the embryonic development of tendons. Mice with targeted inactivation scleraxis ( Scx −/− ) fail to properly form limb tendons, but has regulating growth adaptation tendons adult organisms unknown. To determine if expression changes response physiological stimulus we subjected mice express green fluorescent protein (GFP) under control...

ABSTRACT Tendon injuries occur frequently in physically active individuals, but the clinical outcomes for these can be poor. In many injured tissues repair process is orchestrated by two types of cells, macrophages and fibroblasts. Macrophages, which have both pro‐inflammatory (M1) anti‐inflammatory (M2) phenotypes, directly participate tissue remodeling direct response other cells through secretion cytokines growth factors. organ systems, epithelial trans‐differentiate into fibroblasts,...

Tendon injuries are one of the most common musculoskeletal conditions in active patients. Platelet-rich plasma (PRP) has shown some promise treatment tendon disorders, but little is known as to mechanisms by which PRP can improve regeneration. contains numerous different growth factors and cytokines that activate various cellular signaling cascades, it been difficult determine precisely pathways responses activated after treatment. Additionally, macrophages play an important role modulating...

To evaluate inpatient outcomes among patients with hip fracture treated during the COVID-19 pandemic in New York City.Multicenter retrospective cohort study.One Level 1 trauma center and one orthopaedic specialty hospital City.Fifty-nine consecutive (average age 85 years, range: 65-100 years) for a (OTA/AO 31, 32.1) over 5-week period, March 20, 2020, to April 24, height of crisis.COVID-19 infection status was used stratify patients. The primary outcome mortality. Secondary were admission...

Tendon is a dense connective tissue that stores and transmits forces between muscles bones. Cellular heterogeneity increasingly recognized as an important factor in the biological basis of homeostasis disease, yet little known about diversity cell types populate tendon. To address this, we determined populations within mouse Achilles tendons using single-cell RNA sequencing. In assembling transcriptomic atlas tendons, identified 11 distinct cells, including three previously undescribed...

Myosteatosis is the pathologic accumulation of lipid that can occur in conjunction with atrophy and fibrosis following skeletal muscle injury. Little known about mechanisms by which accumulates myosteatosis, but many clinical studies have demonstrated degree infiltration negatively correlates function regeneration. Our objective was to determine changes result injured fibers. We used a rat model rotator cuff injury this study because group particularly prone development myosteatosis after...

Background: The long incubation period and asymptomatic spread of COVID-19 present considerable challenges for health-care institutions. identification infected individuals is vital to prevent the illness staff other patients as well identify those who may be at risk disease-related complications. This particularly relevant with resumption elective orthopaedic surgery around world. We report results a universal testing protocol in undergoing during coronavirus pandemic describe postoperative...

Myostatin is a negative regulator of muscle mass. The impact myostatin deficiency on the contractile properties healthy muscles has not been determined. We hypothesized that would increase maximum tetanic force (P(o)), but decrease specific P(o) (sP(o)) and susceptibility to contraction-induced injury. in vitro extensor digitorum longus (EDL) soleus from wild-type (MSTN(+/+)), heterozygous-null (MSTN(+/-)), homozygous-null (MSTN(-/-)) adult male mice were For EDL muscles, both MSTN(+/-)...

Objective: The paper addresses the degree to which attainment of status as an elite athlete in different sports ameliorates known age-related losses skeletal muscle structure and function. Design: retrospective design, based on comparisons published data former masters athletes control subjects, assessed ameliorated changes Setting: Institutional. Participants: Elite male athletes. Interventions: Participation selected individual team sports. Main Outcome Measurements: Strength, power,...

Abstract Full‐thickness tears to the rotator cuff can cause severe pain and disability. Untreated progress in size are associated with muscle atrophy an infiltration of fat area, a condition known as “fatty degeneration.” To improve treatment tears, greater understanding changes contractile properties fibers molecular regulation fatty degeneration is essential. Using rat model injury, we measured force generating capacity individual determined fiber type distribution that develop after full...

Background: The repair and restoration of function after chronic rotator cuff tears are often complicated by muscle atrophy, fibrosis, fatty degeneration the diseased muscle. inflammatory response has been implicated in development injuries. Licofelone is a novel anti-inflammatory drug that inhibits 5-lipoxygenase (5-LOX), as well cyclooxygenase (COX)–1 COX-2 enzymes, which play important roles inducing inflammation While previous studies have demonstrated nonsteroidal drugs selective...

Background: After anterior cruciate ligament (ACL) reconstruction, there is significant atrophy of the quadriceps muscles that can limit full recovery and place athletes at risk for recurrent injuries with return to play. The cause this muscle not fully understood. Hypothesis: Circulating levels proatrophy, proinflammatory, cartilage turnover cytokines biomarkers would increase after ACL reconstruction. Study Design: Descriptive laboratory study. Methods: Patients (N = 18; mean age, 28 ± 2.4...

Vascularized composite allografts, particularly hand and forearm, have limited ischemic tolerance after procurement. In bilateral transplantations, this demands a 2 team approach expedited transfer of the allograft, limiting recovery to small geographic area. Ex situ perfusion may be an alternative allograft preservation method extend survival time. This is short report 5 human limbs maintained for 24 hours with ex perfusion.Upper were procured from brain-dead organ donors. Following...

Tendons play a critical role in the transmission of forces between muscles and bones, chronic tendon injuries diseases are among leading causes musculoskeletal disability. Little is known about sex-based differences structure function. Our objective was to evaluate mechanical properties, biochemical composition, transcriptome, cellular activity plantarflexor tendons from 4 month old male female C57BL/6 mice using vitro biomechanics, mass spectrometry-based proteomics, genome-wide expression...

A major goal of rehabilitation after anterior cruciate ligament reconstruction (ACLR) is restoring quadriceps muscle strength. Unfortunately, current paradigms fall short this goal, such that substantial strength deficits can limit return to play and increase the risk recurrent injuries. Blood flow restriction training (BFRT) involves obstruction venous working muscles during exercise may lead better recovery ACLR.To examine efficacy BFRT with high-intensity on function in patients...