The correlation between high-sensitivity troponin-T and cell-free cardiac DNA in the blood of patients undergoing noncardiac, predominantly vascular surgery.

OBJECTIVE: To present a novel method that uses an epigenetic fingerprint to measure changes in plasma concentrations of cardiac-specific cell-free DNA (CS-cfDNA) as a marker of myocardial cell death. METHODS: This prospective, analytic, observational comparative study included patients with heart disease or multiple risk factors for heart disease undergoing major noncardiac, mostly vascular surgery, requiring an arterial-line, and at least 24 h hospitalization in the post anaesthesia care unit or critical care unit after surgery. Blood samples were collected at least four times per patient to measure troponin-T (via high-sensitivity troponin-T test) and CS-cfDNA pre- and postoperatively. RESULTS: A total of 117 patients were included (group 1, 77 patients [66%] with low preoperative and postoperative troponin-T; group 2, 18 patients [15%] with low preoperative but increased postoperative troponin-T; group 3, 16 patients [14%] with high troponin-T both preoperatively and postoperatively; and group 4, six patients [5%] with elevated preoperative troponin-T that decreased postoperatively). The increase in CS-cfDNA after surgery was statistically significant only in group 2, which correlated with an increase in troponin-T in the same group. CONCLUSIONS: CS-cfDNA increased early postoperatively, particularly in patients with silent postoperative troponin elevation, and was correlated with an increase in troponin-T. These results may suggest that, in the subgroup of patients with postoperative elevated troponin, cardiomyocyte death indeed occurred.

Comparison of migration rates between traditional and tunneled adductor canal block catheters: a randomized controlled trial.

INTRODUCTION: Total knee arthroplasty is associated with significant postoperative pain. Continuous adductor canal blocks via an inserted adductor canal catheter are effective analgesia interventions with the advantage of decreasing quadriceps weakness and the potential of extending the analgesic effect. The classical adductor canal catheter insertion technique may have a high likelihood of catheter dislodgement out of the canal. The interfascial plane between the sartorius muscle and femoral artery (ISAFE) approach has the potential of decreasing the adductor canal catheter migration. The purpose of this study was to evaluate the incidence of catheter dislodgment to outside the adductor canal, for ISAFE and classical approaches. We hypothesized that ISAFE approach would result in a lower dislodgment rate. METHODS: Ninety-seven patients for unilateral total knee arthroplasty were included and randomized to either ISAFE intervention group or conventional group. The primary outcome was the incidence of adductor canal catheter dislodged to outside the adductor canal, on ultrasound evaluation, 24 hours after the surgery. Secondary outcomes were pain scores, opioid consumption and continuous adductor canal block related complications for the first 48 hours after surgery. RESULTS: The catheters placed using ISAFE approach had a lower rate of dislodgement in comparison to the control group (18.6% vs 44.9%, respectively, p=0.01), at 24 hours after surgery; and lower pain scores for rest, on the first two postoperative days. CONCLUSIONS: ISAFE group had a significantly lower rate of dislodgement at 24 hours. The continuous adductor canal block analgesic benefit for knee arthroplasty depends on the position of the tip of the catheter inside the adductor canal.

The DNA methylome of human vascular endothelium and its use in liquid biopsies.

BACKGROUND: Vascular endothelial cells (VECs) are an essential component of each tissue, contribute to multiple pathologies, and are targeted by important drugs. Yet, there is a shortage of biomarkers to assess VEC turnover. METHODS: To develop DNA methylation-based liquid biopsies for VECs, we determined the methylome of VECs isolated from freshly dissociated human tissues. FINDINGS: A comparison with a human cell-type methylome atlas yielded thousands of loci that are uniquely unmethylated in VECs. These sites are typically gene enhancers, often residing adjacent to VEC-specific genes. We also identified hundreds of genomic loci that are differentially methylated in organotypic VECs, indicating that VECs feeding specific organs are distinct cell types with a stable epigenetic identity. We established universal and lung-specific VEC markers and evaluated their presence in circulating cell-free DNA (cfDNA). Nearly 2.5% of cfDNA in the plasma of healthy individuals originates from VECs. Sepsis, graft versus host disease, and cardiac catheterization are associated with elevated levels of VEC-derived cfDNA, indicative of vascular damage. Lung-specific VEC cfDNA is selectively elevated in patients with chronic obstructive pulmonary disease (COPD) or lung cancer, revealing tissue-specific vascular turnover. CONCLUSIONS: VEC cfDNA biomarkers inform vascular dynamics in health and disease, potentially contributing to early diagnosis and monitoring of pathologies, and assessment of drug activity. FUNDING: This work was supported by the Beutler Research Program, Helmsley Charitable Trust, JDRF, Grail and the DON Foundation (to Y.D.). Y.D holds the Walter & Greta Stiel Chair in heart studies. B.G., R.S., J.M., D.N., T.K., and Y.D. filed patents on cfDNA analysis.

Biosensor-based kinetic and thermodynamic characterization of opioids interaction with human µ-opioid receptor.

Development of opioid analgesics with minimal side effects requires substantial knowledge on structure-kinetic and -thermodynamic relationship of opioid-receptor interactions. Here, combined kinetics and thermodynamics of opioid agonist binding to human µ-opioid receptor (h-µOR) was investigated using real-time label-free surface plasmon resonance (SPR)-based method. The N-terminal end truncated and C-terminal 6His-tagged h-µOR was constructed and expressed in E. coli. Receptor was purified, detergent-solubilized and characterized by circular dichroism. The uniform immobilization of h-µOR on Ni-NTA chips was achieved using hybrid capture-coupling approach followed by reconstitution in lipid bilayer. Thermodynamic equilibrium affinities of opioids were in narrow nanomolar range and in near quantitative agreement with their Ki values. However, they did not correlate with their in vitro EC50 values, indicating that they might not have thermodynamic selectivity. Contrary, on and off rates exhibited much larger dispersion and well correlated with EC50 values, indicating that opioids might exhibit kinetic-selectivity towards their target. Temperature-dependent SPR assays provided access to rate and equilibrium thermodynamic data, which demonstrated binding of morphine and naloxone to µOR was exothermic and essentially enthalpy driven. This work suggests that kinetic-based structure-activity of opioids in drug design and incorporation into the pharmacokinetics-pharmacodynamics predictions may have more value than thermodynamic equilibrium constants alone.