Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice.

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1ß), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

A randomized trial evaluating the safety profile of sugammadex in high surgical risk ASA physical class 3 or 4 participants.

BACKGROUND: The aim of this randomized, double-blind trial was to evaluate the safety and tolerability profile, including cardiac safety, of sugammadex-mediated recovery from neuromuscular block in participants undergoing surgery who met the American Society of Anesthesiologists (ASA) Physical Class 3 or 4 criteria. Specifically, this study assessed the impact of sugammadex on cardiac adverse events (AEs) and other prespecified AEs of clinical interest. METHODS: Participants meeting ASA Class 3 and 4 criteria were stratified by ASA Class and NMBA (rocuronium or vecuronium) then randomized to one of the following: 1) Moderate neuromuscular block, sugammadex 2 mg/kg; 2) Moderate neuromuscular block, neostigmine and glycopyrrolate (neostigmine/glycopyrrolate); 3) Deep neuromuscular block, sugammadex 4 mg/kg; 4) Deep neuromuscular block, sugammadex 16 mg/kg (rocuronium only). Primary endpoints included incidences of treatment-emergent (TE) sinus bradycardia, TE sinus tachycardia and other TE cardiac arrhythmias. RESULTS: Of 344 participants randomized, 331 received treatment (61% male, BMI 28.5 ± 5.3 kg/m2, age 69 ± 11 years). Incidence of TE sinus bradycardia was significantly lower in the sugammadex 2 mg/kg group vs neostigmine/glycopyrrolate. The incidence of TE sinus tachycardia was significantly lower in the sugammadex 2 and 4 mg/kg groups vs neostigmine/glycopyrrolate. No significant differences in other TE cardiac arrythmias were seen between sugammadex groups and neostigmine/glycopyrrolate. There were no cases of adjudicated anaphylaxis or hypersensitivity reactions in this study. CONCLUSIONS: Compared with neostigmine/glycopyrrolate, incidence of TE sinus bradycardia was significantly lower with sugammadex 2 mg/kg and incidence of TE sinus tachycardia was significantly lower with sugammadex 2 mg/kg and 4 mg/kg. These results support the safety of sugammadex for reversing rocuronium- or vecuronium-induced moderate and deep neuromuscular block in ASA Class 3 or 4 participants. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03346057 .

A Standardized Method for Measurement of Elbow Kinesthesia.

Proprioception is an important component of controlled movement. The threshold to detection of passive movement (TDPM) is a commonly used method for quantifying the proprioceptive submodality of kinesthesia in research settings. The TDPM paradigm has been found to be valid and reliable; however, the equipment and methods used for TDPM vary between studies. In particular, the research laboratory apparatuses for producing passive movement of an extremity are often custom designed by individual laboratories or inaccessible due to high cost. There is a need for a standardized, valid, and reliable method for measuring TDPM using readily available equipment. The purpose of this protocol is to provide a standardized method for measurement of TDPM at the elbow that is economical, easy to administer, and that produces quantitative results for measurement purposes in research-based settings. This method was tested on 20 healthy adults without neurological impairment, and eight adults with chronic stroke. The results obtained suggest this method is a reliable way to quantify elbow TDPM in healthy adults, and provides initial support for validity. Researchers seeking a balance between equipment affordability and measurement precision are most likely to find this protocol of benefit.

Complexity, fractal dynamics and determinism in treadmill ambulation: Implications for clinical biomechanists.

BACKGROUND: Reduced inter-stride complexity during ambulation may represent a pathologic state. Evidence is emerging that treadmill training for rehabilitative purposes may constrain the locomotor system and alter gait dynamics in a way that mimics pathological states. The purpose of this study was to examine the dynamical system components of gait complexity, fractal dynamics and determinism during treadmill ambulation. METHODS: Twenty healthy participants aged 23.8 (1.2) years walked at preferred walking speeds for 6min on a motorized treadmill and overground while wearing APDM 6 Opal inertial monitors. Stride times, stride lengths and peak sagittal plane trunk velocities were measured. Mean values and estimates of complexity, fractal dynamics and determinism were calculated for each parameter. Data were compared between overground and treadmill walking conditions. FINDINGS: Mean values for each gait parameter were statistically equivalent between overground and treadmill ambulation (P>0.05). Through nonlinear analyses, however, we found that complexity in stride time signals (P<0.001), and long-range correlations in stride time and stride length signals (P=0.005 and P=0.024, respectively), were reduced on the treadmill. INTERPRETATION: Treadmill ambulation induces more predictable inter-stride time dynamics and constrains fluctuations in stride times and stride lengths, which may alter feedback from destabilizing perturbations normally experienced by the locomotor control system during overground ambulation. Treadmill ambulation, therefore, may provide less opportunity for experiencing the adaptability necessary to successfully ambulate overground. Investigators and clinicians should be aware that treadmill ambulation will alter dynamic gait characteristics.

A comparison of variability in spatiotemporal gait parameters between treadmill and overground walking conditions.

Motorized treadmills are commonly used in biomechanical and clinical studies of human walking. Whether treadmill walking induces identical motor responses to overground walking, however, is equivocal. The purpose of this study was to examine differences in the spatiotemporal gait parameters of the lower extremities and trunk during treadmill and overground walking using comparison of mean and variability values. Twenty healthy participants (age 23.8±1.2 years) walked for 6min on a treadmill and overground while wearing APDM 6 Opal inertial monitors. Stride length, stride time, stride velocity, cadence, stance phase percentage, and peak sagittal and frontal plane trunk velocities were measured. Mean values were calculated for each parameter as well as estimates of short- (SD1) and long-term variability (SD2) using Poincaré analyses. The mean, SD1, and SD2 values were compared between overground and treadmill walking conditions with paired t-tests (α=0.05) and with effect size estimates using Cohen's d statistic. Mean values for each of the gait parameters were statistically equivalent between treadmill and overground walking (p>0.05). The SD1 and SD2 values representing short- and long-term variability were considerably reduced (p<0.05) on the treadmill as compared to overground walking. This demonstrates the importance of consideration of gait variability when using treadmills for research or clinical purposes. Treadmill training may induce invariant gait patterns, posing difficulty in translating locomotor skills gained on a treadmill to overground walking conditions.

Assessment of mitochondrial biogenesis and mTORC1 signaling during chronic rapamycin feeding in male and female mice.

Chronic inhibition of the protein synthesis regulator mTORC1 through rapamycin extends life span in mice, with longer extension in females than in males. Whether rapamycin treatment inhibits protein synthesis or whether it does so differently between sexes has not been examined. UM-HET3 mice were fed a control or rapamycin-supplemented (Rap) diet for 12 weeks. Protein synthesis in mixed, cytosolic (cyto), and mitochondrial (mito) fractions and DNA synthesis and mTORC1 signaling were determined in skeletal muscle, heart, and liver. In both sexes, mito protein synthesis was maintained in skeletal muscle from Rap despite decreases in mixed and cyto fractions, DNA synthesis, and rpS6 phosphorylation. In the heart, no change in protein synthesis occurred despite the decreased DNA synthesis. In the heart and liver, Rap males were more sensitive to mTORC1 inhibition than Rap females. In conclusion, we show changes in protein synthesis and mTORC1 signaling that differ by sex and tissue.

The Back to School asthma study: the effect of montelukast on asthma burden when initiated prophylactically at the start of the school year.

BACKGROUND: Pediatric asthma hospitalizations peak in early autumn. OBJECTIVE: To determine the effectiveness of montelukast therapy in reducing the asthma burden in children when initiated prophylactically on school return. METHODS: This was a randomized, multicenter, double-blind, placebo-controlled study of children with asthma aged 6 to 14 years. No minimum asthma symptoms were required, and patients could continue inhaled corticosteroid (ICS) use. Montelukast, 5 mg, chewable tablet (n = 580) or matching placebo (n = 582) was taken the night before the first day of school and nightly thereafter for 8 weeks. The primary end point was the percentage of days with worsening asthma, defined by one of the following: (1) increased beta-agonist use, (2) increased daytime symptoms, (3) awake "all night," (4) oral corticosteroid rescue or increased ICS use for worsening asthma, or (5) unanticipated health care utilization. RESULTS: The reduction in the percentage of days with worsening asthma with montelukast use versus placebo use was not significant (24.3% vs 27.2%, P = .07). Prespecified subgroup analyses demonstrated nonsignificant trends favoring montelukast therapy in boys and older children but no effect by baseline ICS use or history of cold symptoms. Post hoc analysis showed a nonsignificant trend favoring montelukast therapy in reducing worsening asthma days for children commencing school after August 15 compared with earlier commencement. CONCLUSIONS: Montelukast use was not significantly more effective than was placebo use in reducing the percentage of days with worsening asthma when initiated at the start of the school year. The effect of montelukast treatment on the fall peak in asthma burden may depend on sex, age, and the date of school return.

The efficacy of montelukast during the allergy season in pediatric patients with persistent asthma and seasonal aeroallergen sensitivity.

OBJECTIVE: To determine the effect of montelukast on asthma during the allergy season in children with persistent asthma and seasonal aeroallergen sensitivity. DESIGN: This 3-week double-blind, placebo-controlled, parallel-group multicenter study compared daily montelukast 5 mg chewable tablets and placebo in patients 6-14 years of age with forced expiratory volume in 1 second (FEV(1)) > or = 60 and < or = 85% predicted, persistent asthma that is also active during allergy season, and documented sensitivity to seasonal allergens. Concomitant inhaled corticosteroid use was permitted in up to 40% of enrolled patients. The primary endpoint was the percentage change from baseline in FEV(1) over 3 weeks of treatment. Additional endpoints included the percentage change from baseline in beta-agonist use, average changes in daytime and nighttime symptom score, AM and PM peak expiratory flow rate (PEFR), investigator's global asthma evaluation, and parent/guardian global asthma evaluation at the end of the treatment period. Adverse experiences (AEs) were collected to assess safety and tolerability. RESULTS: A total of 421 patients were randomized to montelukast (N = 203) or placebo (N = 218). For the primary endpoint, the percentage change from baseline FEV(1), montelukast was not significantly different from placebo (least squares mean 9.53% vs. 9.15%, respectively; p = 0.810). Compared with placebo, montelukast was associated with significantly lower (better) investigator's global asthma evaluation (LS mean 2.71 vs. 2.98; p < 0.05) and parent/guardian global asthma evaluation (LS mean: 2.63 vs. 2.90; p < 0.05) scores. There were no significant differences between treatment groups for the other efficacy evaluations. Both treatments were well tolerated, with no significant differences observed in AE rates. CONCLUSION: Montelukast did not significantly improve FEV(1) compared with placebo over three weeks of treatment during the allergy season in pediatric patients with seasonal allergen sensitivity. (ClinicalTrials.gov identifier: NCT00289874).