KNEE AND ANKLE MUSCLES COACTIVATIONS IN BREASTSTROKE SWIMMING KICK AND RECOVERY: EXPLORATORY APPROACH

The specificities of body position in breaststroke induce important lower limbs solicitations for the swimmers to propel themselves efficiently. Coactivations around the knee and ankle might appear during the powerful leg extension (i.e. push) and for leg replacement (i.e. recovery). The purpose of this exploratory study is to determine muscle activations and coactivations during these two phases at three different velocities. The EMG of four muscles was recorded (BF, RF, GAS and TA). The results showed important activations of the four muscles in the push, contrary to the recovery. However, no significant differences were found for the coactivations in the two phases and for the three velocities. These findings denoted the important resistances occasioned by aquatic environment, both in push and recovery phases, necessitating muscle coactivations to stabilise joints

Osteonecrosis of the femoral head safely healed with autologous, expanded, bone marrow-derived mesenchymal stromal cells in a multicentric trial with minimum 5 years follow-up

Background: Osteonecrosis (ON) of the femoral head represents a potentially severe disease of the hip where the lack of bone regeneration may lead to femoral head collapse and secondary osteoarthritis, with serious pain and disability. The aim of this European, multicentric clinical trial was to prove safety and early efficacy to heal early femoral head ON in patients through minimally invasive surgical implantation of autologous mesenchymal stromal cells (MSC) expanded from bone marrow (BM) under good manufacturing practices (GMP). Methods: Twenty-two patients with femoral head ON (up to ARCO 2C) were recruited and surgically treated in France, Germany, Italy and Spain with BM-derived, expanded autologous MSC (total dose 140 million MSC in 7 mL). The investigational advanced therapy medicinal product (ATMP) was expanded from BM under the same protocol in all four countries and approved by each National Competent Authority. Patients were followed during two years for safety, based on adverse events, and for efficacy, based on clinical assessment (pain and hip score) and imaging (X-rays and MRIs). Patients were also reviewed after 5 to 6 years at latest follow-up for final outcome. Results: No severe adverse event was recalled as related to the ATMP. At 12 months, 16/20 per protocol and 16/22 under intention-to-treat (2 drop-out at 3 and 5 months) maintained head sphericity and showed bone regeneration. Of the 4 hips with ON progression, 3 required total hip replacement (THR). At 5 years, one patient (healed at 2 years visit) was not located, and 16/21 showed no progression or THR, 4/21 had received THR (all in the first year) and 1 had progressed one stage without THR. Conclusions: Expanded MSCs implantation was safe. Early efficacy was confirmed in 80% of cases under protocol at 2 years. At 5 years, the overall results were maintained and 19% converted to THR, all in the first yearThe research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/FP7-HEALTH-2009): REBORNE Project, Grant Agreement 241876. Work in EFS and stromalab was also supported by the Agence Nationale pour la Recherche for support of the national infrastructure: “ECELLFRANCE

Cellules dendritiques et vaccination anti-idiotypique dans les lymphomes B (différentes étapes de validation pré-clinique)

PARIS12-CRETEIL BU Multidisc. (940282102) / SudocSudocFranceF

Specific antibodies modulate the interactions of adenovirus type 5 with dendritic cells

International audienceAdenovirus type 5 (Ad5) is able to induce an efficient CD8+ T lymphocyte (CTL) response against a transgene product, a property thought to be linked to its ability to transduce dendritic cells (DCs). Little, however, is known about the capacity of Ad5 to interact with DCs in the presence of specific antibodies, although most people test positive for antibodies directed against Ad5. In the present study, we found that in the presence of Ad5 antibodies, a large fraction of Ad5 binds very efficiently to DCs, and that this binding is FcgammaRII/FcgammaRIII dependent. Nevertheless, in the presence of high levels of antibodies against the whole virion, Ad5 entry was inhibited. Increased binding led to increased entry in DCs in the presence of fiber-specific antibodies or in the presence of low amounts of a whole antiserum raised against whole virions, showing that the relative concentration of antibodies directed against fiber and penton base plays a major role in entry efficacy. Nevertheless, mice previously immunized with virions or purified fiber developed a lower transgene-specific CD8+ T cell response than naive mice, although their serum appeared to increase virus entry into DCs in vitro

Breaststroke swimmers moderate internal work increases toward the highest stroke frequencies

A model to predict the mechanical internal work of breaststroke swimming was designed. It allowed us to explore the frequency–internal work relationship in aquatic locomotion. Its accuracy was checked against internal work values calculated from kinematic sequences of eight participants swimming at three different self-chosen paces. Model predictions closely matched experimental data (0.58±0.07 vs 0.59±0.05 J kg−1 m−1; t(23)=−0.30, P=0.77), which was reflected in a slope of the major axis regression between measured and predicted total internal work whose 95% confidence intervals included the value of 1 (β=0.84, [0.61, 1.07], N=24). The model shed light on swimmers ability to moderate the increase in internal work at high stroke frequencies. This strategy of energy minimization has never been observed before in humans, but is present in quadrupedal and octopedal animal locomotion. This was achieved through a reduced angular excursion of the heaviest segments (7.2±2.9° and 3.6±1.5° for the thighs and trunk, respectively, P<0.05) in favor of the lightest ones (8.8±2.3° and 7.4±1.0° for the shanks and forearms, respectively, P<0.05). A deeper understanding of the energy flow between the body segments and the environment is required to ascertain the possible dependency between internal and external work. This will prove essential to better understand swimming mechanical cost determinants and power generation in aquatic movements

Distinct Phases of Postnatal Skeletal Muscle Growth Govern the Progressive Establishment of Muscle Stem Cell Quiescence

International audienceMuscle stem cells (or muscle satellite cells [MuSCs]) are required for postnatal growth. Yet, the detailed characterization of myogenic progression and establishment of quiescence during this process remains poorly documented. Here, we provide an overview of myogenic cells heterogeneity and dynamic from birth to adulthood using flow cytometry. We demonstrated that PAX7+ cells acquire an increasing ability to progress in the myogenic program from birth to adulthood. We then simultaneously analyzed the cycling state (KI67 expression) of the MuSCs and progenitors (PAX7+) and their progression into myogenic precursors (PAX7−MYOD+) and differentiating cells (MYOG+) in vivo. We identified two distinct peaks of myogenic differentiation between P7–P10 and P21–P28, and showed that the quiescent MuSC pool is established between 7 and 8 weeks of age. Overall our study provides a comprehensive in vivo characterization of myogenic heterogeneity and demonstrates the highly dynamic nature of skeletal muscle postnatal growth process

Endovascular Cell Therapy Introducing an Anatomical Sparing Strategy in a Preclinical Model of Aortic Isthmus Saccular Aneurysm

International audienceNo abstract availabl

Bibliographie

Bibliographie. In: Paléorient, 1981, vol. 7, n°2. pp. 123-150