Antioxidant status of elite athletes remains impaired 2 weeks after a simulated altitude training camp.

Background: It has been shown that the antioxidant status was altered by the "live high-train low" (LHTL) method, however, no information is available regarding the antioxidant restoration during the recovery period.

Aim Of The Study: We tested the hypothesis that the antioxidant status is impaired by 18 days LHTL in elite athletes and remained altered after 14 days of recovery.

Methods: Eleven elite cross-country skiers from the French Skiing Federation were submitted to 18-day endurance training.

Effects of high and low inspired fractions of oxygen on horse erythrocyte membrane properties, blood viscosity and muscle oxygenation during anaesthesia.

Objectives: To evaluate whether a period of hyperoxia or after a period of hypoxia produced changes attributable to reactive oxygen species in anaesthetized horses.

Study Design: Prospective randomized experimental study.

Animals: Six healthy (ASA I) geldings, aged 4.

Effects of acute hypoxia tests on blood markers in high-level endurance athletes.

The aim of this study was to determine the response of blood markers to acute hypoxia in high-level endurance athletes before training based on "living high-training low" model. Thirty endurance athletes performed a hypoxic cycling test and spent 3 h at rest in a simulated altitude of 3,000 m. At the end of the hypoxic cycling test, the quantity of the natural antisense transcript of HIF-1alpha mRNA (aHIF) transcript increased significantly (+37%, P = 0.

Oxidative stress and HIF-1 alpha modulate hypoxic ventilatory responses after hypoxic training on athletes.

We investigated the strength of the association between oxidative stress, hypoxia inducible factor 1 (HIF-1 alpha) and acute hypoxic ventilatory response (AHVR) after hypoxic training in elite runners. Six elite runners were submitted to 18-day of "living high-training low" (LHTL) and six performed the same training in normoxia. AHVR was measured during an acute hypoxic test before and after training.

Thirteen days of "live high-train low" does not affect prooxidant/antioxidant balance in elite swimmers.

We investigated the impact of 13 days of "living high-training low" (LHTL) on the antioxidant/prooxidant balance in elite endurance swimmers. Eighteen elite swimmers from the French Swimming Federation were submitted to a 13-day endurance training and divided into two groups: one group trained at 1,200 m and lived in hypoxia (2,500-3,000 m simulated altitude) and the second group trained and lived at 1,200 m. The subjects performed an acute hypoxic test (10 min at 4,800 m) before and 1 day after the training period.

Effect of intermittent hypoxic training on HIF gene expression in human skeletal muscle and leukocytes.

Intermittent hypoxic exposure with exercise training is based on the assumption that brief exposure to hypoxia is sufficient to induce beneficial muscular adaptations mediated via hypoxia-inducible transcription factors (HIF). We previously demonstrated (Mounier et al. Med Sci Sports Exerc 38:1410-1417, 2006) that leukocytes respond to hypoxia with a marked inter-individual variability in HIF-1alpha mRNA.

In vitro effects of oxygen on physico-chemical properties of horse erythrocyte membrane.

Whether direct exposure to different concentrations (0%, 13%, 100%) of oxygen may affect horse erythrocyte membrane fluidity (EMF) and fatty acid (FA) composition was studied during 1 (T60) and 2h (T120) exposure. EMF was investigated at the head group level and hydrophobic core thanks to phosphorus nucleus 31 ((31)P) nuclear magnetic resonance ((31)P NMR) and electronic paramagnetic resonance (EPR) using two spin probes: 5-nitroxydestearic acid and 16-doxylstearic acid. Lipid structure of the membranes was studied by gas liquid chromatography.

Leukocyte's Hif-1 expression and training-induced erythropoietic response in swimmers.

Purpose: Altitude training is popular among athletes to augment oxygen delivery capabilities to tissues and to improve physical performance. Hypoxia inducible factor-1 (HIF-1) controls the expression of several genes' encoding involved in physiological responses towards reduced oxygen availability, in particular by increasing serum erythropoietin (EPO). It may be involved in the individual variability for erythropoietic markers and/or sea-level performance of athletes using altitude during their training.

Skeletal muscle expression of LDH and monocarboxylate transporters in growing rats submitted to protein malnutrition.

Background: In different circumstances such as infant malnutrition, old age or chronic disease, decline of muscular strength, particularly anaerobic power, is shown. In this context, our laboratory, has demonstrated a decrease in anaerobic glycolytic power in pre-pubertal Bolivian children living at low and high altitude and suffering from marginal protein malnutrition.

Aim Of The Study: To bring molecular support to the relationship between protein malnutrition and anaerobic glycolytic metabolism, we studied the impact of prolonged protein malnutrition on lactate metabolism in different muscles of growing rats.

Contributing factors and variability of energy expenditure in non-obese, obese, and post-obese adolescents.

Energy expenditure (EE) is a major determinant of energy balance and body composition. The objectives of this paper were to review the contributing factors of the main components of daily EE (DEE) and the inter-individual variability in these components in non-obese (NOb), obese (Ob), and post-obese (POb) adolescents. Body composition especially fat-free mass (FFM), is the major determinant of the basal metabolic rate which contributes 50-70% of DEE, whereas fat mass (FM) is a significant factor only in obese subjects.

An image-guided system-drilled surgical template and trephine guide pin to make treatment of completely edentulous patients easier: a clinical report on immediate loading.

Purpose: An image-guided system has been developed to drill a conventional surgical guide following a preoperative three-dimensional plan for accurate placement of implant on bone. The aim of this study is to illustrate how this system facilitates treatment of completely edentulous patients by modifying both surgical and prosthetic protocols, thereby making flapless surgery possible as well as the preparation of the transitional prosthesis before surgery.

Materials And Methods: This system was tested on 10 consecutive patients, placing all planned implants without raising the mucoperiosteal flap and with the connection of all implants to pre-angulated abutments.

Estimating relative physical workload using heart rate monitoring: a validation by whole-body indirect calorimetry.

Measuring physical workload in occupational medicine is fundamental for risk prevention. An indirect measurement of total and relative energy expenditure (EE) from heart rate (HR) is widely used but it has never been validated. The aim of this study was to validate this HR-estimated energy expenditure (HREEE) method against whole-body indirect calorimetry.

Effect of equilibrated hydration changes on total body water estimates by bioelectrical impedance analysis.

The present study was performed to determine how equilibrated fluctuations in hydration affected the validity of bioelectrical impedance analysis (BIA) for body composition assessment. Total body water (TBW) expansion was induced by a 4 d endurance trial and the subsequent water loss was obtained over the recovery period. Twelve healthy men exercised on a cycle and treadmill alternately for 5 h/d over 4 d at moderate intensity.

Reliability of preoperative planning of an image-guided system for oral implant placement based on 3-dimensional images: an in vivo study.

Purpose: The purpose of this study was to assess the reliability of the planning software of an image-guided implant placement system based on a mechanical device coupled with a template stabilized on soft tissue during surgery.

Materials And Methods: Thirty consecutive partially or completely edentulous patients were treated with the image-guided system. For each patient, a study prosthesis was fabricated and duplicated in acrylic resin and served as a scanning template.

Prolonged daytime exercise repeated over 4 days increases sleeping heart rate and metabolic rate.

The aim of this study was to determine the influence of prolonged exercise repeated for 4 days on sleeping heart rate (SHR) and metabolic rate (SMR). Eleven young untrained men exercised at moderate intensity 5 hrs daily for 4 days, alternately on a cycle ergometer (57.0 +/- 1.

Expression of lactate dehydrogenase A and B genes in different tissues of rats adapted to chronic hypobaric hypoxia.

Lactate dehydrogenase (LDH) is a tetramer made up of two different subunits A and B. In cellular models, severe hypoxia increases LDH A gene expression whereas LDH B gene does not exhibit any regulation. The aim of our work was to characterise LDH expression in different tissues of rats bred at high altitude.

Effect of high altitude on protein metabolism in Bolivian children.

In Bolivia, malnutrition in children is a major health problem that may be caused by inadequate protein, energy, and micronutrient intake; exposure to bacterial and parasitic infections; and life in a multistress environment (high altitude, cold, cosmic radiation, low ambient humidity). However, no data on protein absorption and utilization at high altitude were available. Therefore, we evaluated the effect of altitude on protein metabolism in Bolivian children.

Human albumin synthesis is increased by an ultra-endurance trial.

Purpose: The purpose of this study was to determine whether an ultra-endurance event is a strong stimulus to increase albumin synthesis involved in the process of intravascular albumin mass increase associated with transient hypervolemia.

Methods: The albumin synthetic rate was measured in six young men, 3 d before (C) and on the 1st (R1) and 8th (R8) days of the recovery from an ultra-endurance trial (5 h daily for 4 d). Albumin fractional (FSR) and absolute (ASR) synthetic rate were determined using a primed-constant infusion of [1(-13) C] leucine.

Gender Difference in the Relationship of Anaerobic Power Output to Body Composition in Children.

This study was done to determine the extent to which body composition accounts for differences in anaerobic characteristics between 12-year-old girls and boys. Peak leg power (PP), mean leg power (MP), percent body fat, fat free mass (FFM), and lean thigh volume (LTV) were determined by various tests. Pubertal stages and salivary testosterone concentration (in boys) were used to assess sexual maturation.