Synthesis of galactomannan fragments to help NMR assignment of polysaccharides extracted from lichens.

The synthesis of six model trisaccharides representative of galactomannans produced by lichens was performed through stereoselective glycosylation. These standards include linear and branched galactomannans bearing either galactofuranosyl or galactopyranosyl entities. The complete assignment of 1H and 13C signals for both forms of synthetically reduced oligosaccharides was performed. The resulting NMR data were used to quickly demonstrate the structural characteristics of minor polysaccharides within different extracts of three representative lichens.

Gas-Phase Behavior of Galactofuranosides upon Collisional Fragmentation: A Multistage High-Resolution Ion Mobility Study.

Carbohydrates are ubiquitous in nature but are among the least conserved biomolecules in life. These biopolymers pose a particular challenge to analytical chemists because of their high diversity and structural heterogeneity. In addition, they contain many isomerisms that complicate their structural characterization, notably by mass spectrometry. The tautomerism of the constitutive subunits is of particular interest. A given cyclized monosaccharide unit can take two forms: a most common 6-membered ring (pyranose, p) and a more flexible 5-membered ring (furanose, f). The tautomers impact the biological properties of polysaccharides, resulting in interesting properties of the derived oligosaccharides. From an analytical point of view, the impact of tautomerism on the gas-phase behavior of ions has scarcely been described in the literature. In this work, we study the behavior of Galf-containing oligosaccharides, ionized as [M+Li]+ species, under collisional dissociation (CID) conditions using high-resolution and multistage ion mobility (IMS) on a Cyclic IMS platform. In the first part of this work, we studied whether disaccharidic fragments released from Galf-containing (Gal)1(Man)2 trisaccharides (and their Galp counterpart) would match the corresponding disaccharide standards, and─despite the fragments generally being a good match─we showed the possibility of Galf migrations and other unidentified alterations in the IMS profile. Next, we expanded on these unknown features using multistage IMS and molecular dynamics, unveiling the contributions of additional gas-phase conformers in the profile of fragments from a Galf-containing trisaccharide compared with the corresponding disaccharides.

Impact of aerobic training periodisation on global and regional right ventricular strain in coronary heart disease.

Linear aerobic training periodisation (LP) is recommended for patients with coronary heart disease (CHD). However, the effects of training periodisation on the right heart mechanics in patients with CHD have never been examined. This study aimed to explore the effects of LP and non-linear periodisation (NLP) on right heart mechanics. We prospectively randomised CHD patients to 12 weeks of aerobic training with LP or NLP. While there was a weekly increase in energy expenditure with LP, there was a steeper increase during the first 3 weeks, followed by a decrease in the fourth week with NLP. Echocardiography was performed at baseline and after the training period to assess the right ventricular free wall (RVFW) and right atrial strain. Thirty patients with CHD were included (NLP, n = 16; LP, n = 14). The traditional right and left heart parameters showed no significant time effects. There was a decrease of RVFW strain with time in both groups (+1.3 ± 0.9% with NLP, and +1.5 ± 0.8% with LP; p = 0.033). Mid-ventricular RVFW strain changed significantly with time (+2.0 ± 1.3% with NLP, and from +2.3 ± 1.2% with LP; p = 0.025). There was no time effect on the right atrial strain. In stable CHD patients, LP and NLP resulted in right ventricular strain decrements with a segment-specific pattern. This study was registered at ClinicalTrials.gov (identifier number: NCT03414996). Novelty: In stable coronary heart disease patients, both linear and non-linear aerobic training periodisation programs result in right ventricular strain decrements with time, particularly in the mid-ventricular segment. Traditional right and left heart parameters and right atrial strain showed no significant time effect in both 12 weeks aerobic training periodisation programs.

Impact of 2 different aerobic periodization training protocols on left ventricular function in patients with stable coronary artery disease: an exploratory study.

We compared the impacts of linear (LP) and nonlinear (NLP) aerobic training periodizations on left ventricular (LV) function and geometry in coronary artery disease (CAD) patients. Thirty-nine CAD patients were randomized to either a 3-month isoenergetic supervised LP or NLP. All underwent standard echocardiography with assessment of 3D LV ejection fraction (LVEF), diastolic function, strain (global longitudinal, radial, and circumferential), and strain rate at baseline and study end. Training was performed 3 times/week and included high-intensity interval and moderate-intensity continuous training sessions. Training load was progressively increased in the LP group, while it was deeply increased and intercepted with a recovery week each fourth week in the NLP group. For the 34 analyzed patients, we found similar improvements for 3D LVEF (effect size (ES): LP, 0.29; NLP, 0.77), radial strain (ES: LP, 0.58; NLP, 0.48), and radial strain rate (ES: LP, 0.87; NLP, 0.17) in both groups (time for all: p ≤ 0.01). All other parameters of cardiac function remained similar. In conclusion, NLP and LP led to similar improvements in 3D LVEF and radial strain, suggesting a favourable positive cardiac remodelling through myofibers reorganization. These findings must be investigated in patients with more severe cardiac dysfunction. The study was registered on ClinicalTrials.gov (NCT03443193). Novelty: Linear and nonlinear periodization programs improved radial strain, accompanied by improvement of ejection fraction. Both aerobic periodization programs did not negatively impact cardiac function in coronary artery disease patients.

Impact of glucose concentration on cardiac ventricular repolarization under I Kr/I Ks blocking agents.

Drug-induced QT interval prolongation is a condition likely to be aggravated by diabetes. The objective of this study was to evaluate how glucose concentration may modulate drug effects on ventricular repolarization and on cardiac repolarizing potassium currents. Guinea pig hearts were Langendorff-retroperfused and monophasic action potential duration (MAPD) was measured. Glucose (1, 5 or 20 mmol/L) was tested with either dofetilide (a specific I(Kr) blocker), chromanol 293B (a specific I(Ks) blocker) or both. Effects of glucose (1, 5 or 20 mmol/L) on I(Kr) blockade mediated by dofetilide were also measured in HERG-transfected HEK293 cells in the absence vs presence of the P-glycoprotein drug transporter, using the whole cell patch-clamp technique. Our results suggest that both hypo- and hyperglycemia potentiate the MAPD-prolonging and I(Kr)-blocking properties of dofetilide. P-glycoprotein drug extrusion efficacy appears as a key determinant of dofetilide's I(Kr)-blocking effect. This efficacy appears to be affected by glucose concentration, particularly hyperglycemia.

Novel Approaches to Define Outcomes in Coronary Revascularization.

Coronary revascularization is done to alleviate the patient symptoms or to improve prognosis. Despite these clinical indications, significant variability exists in the risk assessment tools used to select patients for coronary revascularization, to the extent of revascularization performed and, in our approaches to define "optimal" revascularization. The goal of this review is to evaluate novel approaches that can assess coronary artery disease before and after revascularization, define the thresholds of these approaches that have been shown to improve morbidity and mortality, and highlight future directions for research in this area. The novel approaches defining coronary revascularization described in this review are split among quality of life metrics, risk scores, noninvasive imaging outcomes, invasive imaging outcomes, and physiological measurements.

The impact of high-intensity interval training on ventricular remodeling in patients with a recent acute myocardial infarction-A randomized training intervention pilot study.

BACKGROUND: Aerobic exercise training is associated with beneficial ventricular remodeling and an improvement in cardiac biomarkers in chronic stable heart failure. High-intensity interval training (HIIT) is a time-efficient method to improve V ˙ O 2 peak in stable coronary heart disease patients. This pilot study aimed to compare the effect of HIIT on ventricular remodeling in patients with a recent acute myocardial infarction (AMI). METHODS: Nineteen post-AMI patients were randomized to either HIIT (n = 9) or usual care (n = 10). A cardiopulmonary exercise test (CPET), transthoracic echocardiography, and cardiac biomarker assessment (ie, N-terminal pro B-type natriuretic peptide levels and G protein-coupled receptor kinase 2 expression) were performed before and after a 12-week training intervention. CPET parameters including oxygen uptake efficiency slope (OUES) and V ˙ O 2 at the first ventilatory threshold ( V ˙ O 2 VT1) were calculated. left ventricular (LV) structural and functional echocardiographic parameters including myocardial strain imaging were assessed. RESULTS: V ˙ O 2 peak and OUES improved solely in the HIIT group (P < .05 for group/time, respectively). There was a significant training effect for the improvement of peak work load in both groups (P < .05). O2 pulse and V ˙ O 2 at VT1 both improved only in the HIIT group (P < .05 for time, no interaction). HIIT improved radial strain and pulsed-wave tissue Doppler imaging derived e' (P < .05 for time, no interaction). Cardiac biomarkers did not change in either group. CONCLUSIONS: In post-AMI patients, HIIT lead to significant improvements in prognostic CPET parameters compared to usual care. HIIT was associated with favorable ventricular remodeling regarding certain echocardiographic parameters of LV function.