Persisting Elevation of Total Hemoglobin Mass After Altitude Training in Elite Swimmers: a Potential Role of Prolonged Erythrocyte Survival.

Altitude training camps are frequently used by endurance athletes to increase total hemoglobin mass (Hb) and potentially aerobic performance. However, the effects of such intervention on red blood cell (RBC) properties remain largely unexplored, although these factors could influence the physiological responses following altitude training. This self-controlled study investigated the effects of a "Live High-Train High" (LHTH) altitude training camp on RBC senescence and Hb in 9 elite swimmers.

Quantification of the Effect of Saddle Fitting on Rider-Horse Biomechanics Using Inertial Measurement Units.

The saddle's adaptability to the rider-horse pair's biomechanics is essential for equestrian comfort and performance. However, approaches to dynamic evaluation of saddle fitting are still limited in equestrian conditions. The purpose of this study is to propose a method of quantifying saddle adaptation to the rider-horse pair in motion.

Differences in oxygen-gradient ektacytometry parameters and blood viscosity between patients with sickle cell anemia and patients with sickle cell-hemoglobin C disorder.

Oxygen-gradient ektacytometry (oxygenscan) has been recently used in the context of sickle cell disease (SCD) to determine the ability of red blood cells (RBCs) to deform in normoxia and during deoxygenation. While several studies focused on the determinants of oxygenscan parameters in the homozygous form of SCD (i.e.

Impact of elevated red blood cell membrane cholesterol in sickle cell anemia patients: Effects of BRN-002, a 2-hydroxypropyl-β-cyclodextrin derivate, on red blood cell lipids, deformability, sickling and hemolysis.

Sickle cell anemia (SCA) patients are characterized by poorly deformable and fragile red blood cells (RBCs). Few studies reported an increased cholesterol content in SCA RBC membrane. However, the consequences of this elevated cholesterol level in the above-mentioned RBC alterations are currently unknown.

Effect of dalcetrapib, voxelotor and their combination on red blood cell deformability and sickling in sickle cell disease.

The aim of the present study was to test the effects of dalcetrapib and voxelotor on red blood cells (RBC) of sickle cell patients. Oxygen gradient ektacytometry was performed to measure RBC deformability in normoxia and hypoxia, as well as the propensity of RBC to sickle. Voxelotor and dalcetrapib reduced the propensity of RBC to sickle under deoxygenation and increased RBC deformability in hypoxia.

Comprehensive analysis of sickle β-thalassemia genotypes and their associated HbA levels in France.

We retrospectively reviewed the clinical records of 228 HbS/β-thal patients. The different genotypes were distributed into three groups according to their mean residual HbA levels: <10 % (group 1; n = 22), between 10 and 20 % (group 2; n = 175) and > 20 % (group 3; n = 31). Routine red blood cells and hemoglobin parameters were compared between the three groups.

Impact of Hematocrit on Coagulation Measured by Rotational Thromboelastometry in Healthy Subjects and Patients with Polycythemia.

Thrombotic and cardiovascular events are among the leading causes of death for patients with polycythemia, more specifically for those with primary origin. It has been suggested that the high hematocrit (Hct) would favor hypercoagulability. However, the impact of Hct on coagulation in patients with polycythemia has not been investigated so far.

A replication study of novel fetal hemoglobin-associated genetic variants in sickle cell disease-only cohorts.

Sickle cell disease (SCD) is the most common monogenic disease in the world and is caused by mutations in the β-globin gene (HBB). Notably, SCD is characterized by extreme clinical heterogeneity. Inter-individual variation in fetal hemoglobin (HbF) levels strongly contributes to this patient-to-patient variability, with high HbF levels associated with decreased morbidity and mortality.

Evaluation of a New Tandem Mass Spectrometry Method for Sickle Cell Disease Newborn Screening.

In France, sickle cell disease newborn screening (SCD NBS) has been targeted to at-risk regions since 1984, but generalization to the whole population will be implemented from November 2024. Although tandem mass spectrometry (MS/MS) is already used for the NBS of several inherited metabolic diseases, its application for SCD NBS has not been widely adopted worldwide. The aim of this study was to evaluate a dedicated MS/MS kit (Targeted MS/MS Hemo, ZenTech, LaCAR Company, Liege, Belgium) for SCD NBS and to compare the results obtained with those from an NBS reference center using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and cation-exchange high-performance liquid chromatography (CE-HPLC, Variant NBS, Biorad Laboratories, Inc.

Impaired microvascular function in patients with sickle cell anemia and leg ulcers improved with healing.

Leg Ulcer (LU) pathophysiology is still not well understood in sickle cell anaemia (SCA). We hypothesised that SCA patients with LU would be characterised by lower microvascular reactivity. The aim of the present study was to compare the microcirculatory function (transcutaneous oxygen pressure (TcPO) on the foot and laser Doppler flowmetry on the arm) and several blood biological parameters between nine SCA patients with active LU (LU+) and 56 SCA patients with no positive history of LU (LU-).

Oxygen gradient ektacytometry-derived biomarkers are associated with acute complications in sickle cell disease.

We investigated the potential of the point of sickling (PoS; the pO2 tension at which red cells start to sickle), determined by oxygen gradient ektacytometry to serve as a biomarker associated with the incidence of acute sickle cell disease-related complications in 177 children and 50 adults. In the pediatric cohort, for every 10 mmHg increase in PoS reflecting a greater likelihood of sickling, the likelihood of an individual experiencing >1 type of acute complication increased; the adjusted odds ratio (aOR) was 1.65.

Vascular pathophysiology of sickle cell disease.

Sickle cell disease (SCD) is an hereditary disorder characterized by the production of an abnormal hemoglobin called hemoglobin S (HbS). HbS may polymerize in deoxygenated conditions, which leads to red blood cell (RBC) sickling. Sickled RBCs are more rigid and fragile, and prone to lysis.

A preliminary study of phosphodiesterases and adenylyl cyclase signaling pathway on red blood cell deformability of sickle cell patients.

Sickle cell disease (SCD) is an inherited hemoglobinopathy characterized by chronic anemia, intravascular hemolysis, and the occurrence of vaso-occlusive crises due to the mechanical obstruction of the microcirculation by poorly deformable red blood cells (RBCs). RBC deformability is a key factor in the pathogenesis of SCD, and is affected by various factors. In this study, we investigated the effects of adenylyl cyclase (AC) signaling pathway modulation and different phosphodiesterase (PDE) modulatory molecules on the deformability and mechanical stress responses of RBC from SCD patients (HbSS genotype) by applying 5 Pa shear stress with an ektacytometer (LORRCA).

[Impact of voxelotor on hemoglobin electrophoretic and chromatographic profiles].

Voxelotor (GBT440, OXBRYTA®) appeared recently as one of the possible treatments for sickle cell disease. This molecule, by binding the alpha globin of hemoglobin, causes hyperaffinity of the latter for oxygen and reduces its polymerization properties. Several therapeutic trials have been able to show its effectiveness on certain aspects of sickle cell disease; thus, the french HAS (High Authority of Health) college issued an early access authorization and, since 2021, this treatment can be offered to patients under a temporary authorization for use.

Increased retention of functional mitochondria in mature sickle red blood cells is associated with increased sickling tendency, hemolysis and oxidative stress.

Abnormal retention of mitochondria in mature red blood cells (RBC) has been recently reported in sickle cell anemia (SCA) but their functionality and their role in the pathophysiology of SCA remain unknown. The presence of mitochondria within RBC was determined by flow cytometry in 61 SCA patients and ten healthy donors. Patients were classified according to the percentage of mature RBC with mitochondria contained in the whole RBC population: low (0-4%), moderate (>4% and <8%), or high level (>8%).

Piezo1 activation augments sickling propensity and the adhesive properties of sickle red blood cells in a calcium-dependent manner.

Haemoglobin S polymerization in the red blood cells (RBCs) of individuals with sickle cell anaemia (SCA) can cause RBC sickling and cellular alterations. Piezo1 is a mechanosensitive protein that modulates intracellular calcium (Ca ) influx, and its activation has been associated with increased RBC surface membrane phosphatidylserine (PS) exposure. Hypothesizing that Piezo1 activation, and ensuing Gárdos channel activity, alter sickle RBC properties, RBCs from patients with SCA were incubated with the Piezo1 agonist, Yoda1 (0.

Effects of a Maximal Exercise Followed by a Submaximal Exercise Performed in Normobaric Hypoxia (2500 m), on Blood Rheology, Red Blood Cell Senescence, and Coagulation in Well-Trained Cyclists.

Acute normoxic exercise impacts the rheological properties of red blood cells (RBC) and their senescence state; however, there is a lack of data on the effects of exercise performed in hypoxia on RBC properties. This crossover study compared the effects of acute hypoxia vs. normoxia on blood rheology, RBC senescence, and coagulation during exercise.