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1.
Scand J Med Sci Sports ; 28(9): 2023-2034, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29723911

ABSTRACT

This study compared professional ballet dancers (n = 10) to nonstretching controls (n = 10) with the purpose of comparing muscle and tendon morphology, mechanical, neural, and functional properties of the triceps surae and their role for ankle joint flexibility. Torque-angle and torque-velocity data were obtained during passive and active conditions by use of isokinetic dynamometry, while tissue morphology and mechanical properties were evaluated by ultrasonography. Dancers displayed longer gastrocnemius medialis fascicles (55 ± 5 vs 47 ± 6 mm) and a longer (207 ± 33 vs 167 ± 10 mm) and more compliant (230 ± 87 vs 364 ± 106 N/mm) Achilles tendon compared to controls. Greater passive ankle dorsiflexion range of motion (40 ± 7 vs 17 ± 9°) was seen in dancers, resulting from greater fascicle strain and greater elongation of the muscle. Peak electromyographic (EMG) activity recorded during passive stretching was lower in dancers, and at common joint angles, dancers displayed lower EMG amplitude and lower passive joint stiffness. No differences between groups were seen in maximal isometric plantar flexor torque, isokinetic peak torque, angle of peak torque, or work. In conclusion, the greater ankle joint flexibility of professional dancers seems attributed to multiple differences in morphological and mechanical properties of muscle and tendinous tissues, and to factors related to neural activation.


Subject(s)
Achilles Tendon/physiology , Ankle Joint/physiology , Dancing , Muscle, Skeletal/physiology , Range of Motion, Articular , Adult , Athletes , Case-Control Studies , Female , Humans , Torque , Young Adult
2.
Ann Chir Plast Esthet ; 54(1): 16-20, 2009 Feb.
Article in French | MEDLINE | ID: mdl-19042073

ABSTRACT

UNLABELLED: Based on a new concept, a procedure combining induced membranes and cancellous autografts allows the reconstruction of wide diaphyseal defects. To date, this procedure is limited by the amount of cancellous bone available from the patient and by the related morbidity at the donor site. The aim of this study was to evaluate the biological effect of induced membranes on a cylindrical-shaped ceramic implants loaded with OP-1 in heterotopic site. MATERIALS AND METHODS: Sixty hydroxyapatite tricalcium phosphate (HA-TCP) implants, 20 of which being loaded with a bone growth factor (rhOP-1) were inserted either in a subcutaneous tunnel or within a previously induced membrane on the back of rabbits. There were two time-points at four and 16 weeks. Implants were investigated at three different levels (extremities and middle). RESULTS: None of the untreated implants showed any evidence of bone formation. Implants inserted in an induced membrane presented with less resorption. Bone ingrowth within the pores of the materials was significantly higher when the implants were inserted into the induced membrane whatever the time-point considered. CONCLUSION: The membrane seems to play the role it was assigned, i.e. to protect and revascularize the implant, thus favouring osteogenesis that occurs in 80% of the implants after four months.


Subject(s)
Calcium Phosphates/metabolism , Ceramics , Implants, Experimental , Membranes, Artificial , Osteogenesis , Transforming Growth Factors/metabolism , Animals , Back , Choristoma , Guided Tissue Regeneration/methods , Models, Animal , Rabbits , Subcutaneous Tissue
3.
Cell Biol Int ; 27(5): 439-43, 2003.
Article in English | MEDLINE | ID: mdl-12758092

ABSTRACT

To study the influence of smooth muscle cells (SMC) on endothelial cells (EC), different co-culture designs are available, including EC seeding on SMC extracellular matrix (ECM). We explored human umbilical vein endothelial cell (HUVEC) adhesion and proliferation on either in situ or coated ECM, elaborated by HUVECs or human arterial smooth muscle cells (HUASMCs), in the presence of different nutrient media containing varying amounts of fetal calf serum. Coating wells with HUVEC or HUASMC ECMs did not improve HUVEC adhesion 1 h after cell seeding, compared with uncoated wells. HUVEC adhesion on in situ HUVEC-ECM and HUASMC-ECM was significantly increased compared with uncoated wells. The substratum upon which cells are maintained was found to play a crucial role, in conjunction with the medium to which HUVECs are exposed for their proliferative response. These results stress the importance of selecting media in relation to the particular substratum, in order to avoid misinterpretation of data.


Subject(s)
Culture Media/pharmacology , Endothelial Cells/drug effects , Endothelial Cells/physiology , Extracellular Matrix/drug effects , Extracellular Matrix/physiology , Cell Adhesion/drug effects , Cell Adhesion/physiology , Cells, Cultured , Endothelial Cells/cytology , Humans
4.
Am J Physiol Cell Physiol ; 282(4): C775-85, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11880266

ABSTRACT

Bone development and remodeling depend on complex interactions between bone-forming osteoblasts and other cells present within the bone microenvironment, particularly vascular endothelial cells that may be pivotal members of a complex interactive communication network in bone. Our aim was to investigate the interaction between human umbilical vein endothelial cells (HUVEC) and human bone marrow stromal cells (HBMSC). Cell differentiation analysis performed with different cell culture models revealed that alkaline phosphatase activity and type I collagen synthesis were increased only by the direct contact of HUVEC with HBMSC. This "juxtacrine signaling" could involve a number of different heterotypic connexions that require adhesion molecules or gap junctions. A dye coupling assay with Lucifer yellow demonstrated a functional coupling between HUVEC and HBMSC. Immunocytochemistry revealed that connexin43 (Cx43), a specific gap junction protein, is expressed not only in HBMSC but also in the endothelial cell network and that these two cell types can communicate via a gap junctional channel constituted at least by Cx43. Moreover, functional inhibition of the gap junction by 18alpha-glycyrrhetinic acid treatment or inhibition of Cx43 synthesis with oligodeoxyribonucleotide antisense decreased the effect of HUVEC cocultures on HBMSC differentiation. This stimulation could be mediated by the intercellular diffusion of signaling molecules that permeate the junctional channel.


Subject(s)
Cell Communication/physiology , Endothelium, Vascular/cytology , Gap Junctions/physiology , Osteoblasts/cytology , Stem Cells/cytology , Bone Marrow Cells/cytology , Cell Differentiation/physiology , Cells, Cultured , Coculture Techniques , Connexin 43/genetics , Connexin 43/metabolism , Gap Junctions/metabolism , Gene Expression/physiology , Humans , Mesoderm/cytology , Stromal Cells/cytology , Umbilical Veins/cytology
5.
J Cell Biochem ; 79(4): 672-85, 2000 Sep 14.
Article in English | MEDLINE | ID: mdl-10996857

ABSTRACT

Angiogenesis is a tightly regulated process involved in growth, repair, and bone remodeling. Several studies have shown that there is a reciprocal regulation and functional relationship between endothelial cells and osteoblast-like cells during osteogenesis, where systemic hormones and paracrine growth factors play an active role. Angiogenesis is induced by a variety of growth factors; among them vascular endothelial growth factor (VEGF) may be an important mediator for the angiogenic process involved in bone physiology. We studied the VEGF effect on osteoblast progenitor cells (Human Bone Marrow Stromal Cells: HBMSE) cultured alone or associated with endothelial cells (Human Umbilical Vein Endothelial Cells: HUVEC) in different co-culture models (co-culture with or without direct contact, conditioned medium), to determine the influence of VEGF on these cells and on their relationship. In agreement with other studies, we show that HBMSC express and synthesize VEGF, HUVEC conditioned medium has a proliferative effect on them, and early osteoblastic marker (Alkaline phosphatase activity) levels increase when these cells are co-cultured with HUVEC only in direct contact. However, unlike previous studies, we did not find that VEGF increased these processes. These results suggest that the intercommunication between endothelial cells and osteoblastic-like cells requires not only diffusible factors, but also involving cell membrane proteins.


Subject(s)
Bone Marrow Cells/cytology , Bone Marrow Cells/physiology , Endothelial Growth Factors/physiology , Endothelium, Vascular/cytology , Lymphokines/physiology , Alkaline Phosphatase/metabolism , Base Sequence , Bone Marrow Cells/drug effects , Cell Communication/physiology , Cell Differentiation , Cell Division , Coculture Techniques , Culture Media, Conditioned , DNA Primers/genetics , Endothelial Growth Factors/genetics , Endothelial Growth Factors/pharmacology , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiology , Extracellular Matrix/physiology , Gene Expression , Humans , Lymphokines/genetics , Lymphokines/pharmacology , Neovascularization, Physiologic/drug effects , Osteocalcin/biosynthesis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor Protein-Tyrosine Kinases/genetics , Receptors, Growth Factor/genetics , Receptors, Vascular Endothelial Growth Factor , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
6.
J Biomed Mater Res ; 46(3): 368-75, 1999 Sep 05.
Article in English | MEDLINE | ID: mdl-10397994

ABSTRACT

The attachment of human umbilical vein endothelial cells (HUVECs) on substrates that had been covalently grafted with the cell adhesion peptides Arg-Gly-Asp (RGD) was investigated. This approach was used to provide substrates that are adhesive to cells even in the absence of serum proteins and to cells that have had no prior treatment of the surface with proteins that promote cell adhesion. We wanted to improve control of cellular interactions with cell-adhesive materials by providing fixedly bound adhesion ligands. Silica was examined as a model surface. The peptides were grafted using three different steps: grafting of aminosilane molecules; reaction with a maleimide molecule; and immobilization of cell-binding peptides containing the RGD sequence. The RGD-grafted surface was characterized by X-ray photoelectron spectroscopy (XPS) and contact-angle measurements.


Subject(s)
Cell Transplantation , Endothelium, Vascular/cytology , Oligopeptides , Silicon Dioxide/chemistry , Spectrometry, X-Ray Emission , Amino Acid Sequence , Cell Adhesion , Cells, Cultured , Cross-Linking Reagents , Humans , Maleimides/chemistry , Molecular Sequence Data , Surface Properties , Wettability
7.
Med Biol Eng Comput ; 36(2): 256-7, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9684472

ABSTRACT

The paper deals with the in vitro assessment of endothelial cell (EC) phenotype covering an albumin- and chitosan-coated polyester fabric and shows that resting ECs express a pro-coagulant phenotype by releasing a high von Willebrand factor level and expressing low thrombomodulin surface activity, despite maintaining an adequate response to stimulating agents.


Subject(s)
Biocompatible Materials , Blood Coagulation , Endothelium, Vascular/cytology , Endothelium, Vascular/physiology , Polyesters , Humans , RNA, Messenger/analysis , Thrombomodulin/genetics , Thrombomodulin/metabolism , Umbilical Veins/cytology , von Willebrand Factor/metabolism
8.
J Mater Sci Mater Med ; 8(12): 877-9, 1997 Dec.
Article in English | MEDLINE | ID: mdl-15348808

ABSTRACT

The concept of endothelial cell seeding of vascular prostheses is designed as a method for improving long-term patency substitutes because endothelium is considered as the haemocompatible surface of reference. The assessment of the functionality of cells lining a biomaterial is thus of crucial importance. We have reported encouraging results concerning the ability of a polyester coated with albumin and chitosan (M 11) to be lined by a confluent monolayer of cultured human endothelial cells (EC). The aim of the present work was to study the expression of thrombomodulin (membrane glycoprotein responsible for anticoagulant activity) in EC lying on M.11 by anticoagulant activity and mRNA level with and without stimulation. Results obtained in basal conditions showed that EC on M.11 have a comparable expression of TM mRNA when compared to control (EC on tissue culture plates) despite a lower TM surface activity for EC on the biomaterial. In terms of ratio (stimulated cells to unstimulated ones) the response in activity for EC on M.11 is comparable to that of the control. These results indicate that cells lying on M.11 are able to respond to physiological-like stimuli, despite a tendency for these cells to express a procoagulant phenotype when compared with control EC.

9.
Cell Biol Toxicol ; 12(4-6): 207-14, 1996 Dec.
Article in English | MEDLINE | ID: mdl-9034610

ABSTRACT

To select an insert suitable for human umbilical vein endothelial cell (HUVEC) culture, we compared several available inserts of 0.2 to 0.45 micron porosity: Cellagen (ICN), Transwell-COL (Costar), Millicell-HA and CM (Millipore), Anopore (Nunc), Cyclopore (Falcon) in comparison with a control surface (Thermanox). The requirements were: (i) to promote attachment, adhesion and proliferation of HUVEC (judged by [3H]thymidine incorporation into DNA at days 1, 3, 7); (ii) to allow HUVEC visualization by inverted, fluorescence microscopy for uptake of DiI-Ac-LDL and scanning electron microscopy, performed at day 9 after seeding. Because Transwell and Cellagen are collagen precoated and CM has to be coated for cell culture, we performed collagen coating (types I + III or IV) for non-pretreated inserts for the purpose of comparison. Our preferences comprise Transwell-COL, Cyclopore not coated or coated (whatever the collagen type), and Cellagen. However, on a quality/price ratio criterion, Cyclopore, even uncoated, is the insert of choice. The HA, CM and Anopore inserts, even coated, do not allow HUVEC growth but do not alter positive uptake of acetylated LDL.


Subject(s)
Endothelium, Vascular/cytology , Umbilical Veins/cytology , Cells, Cultured , Coculture Techniques/economics , Coculture Techniques/methods , Culture Media/analysis , Humans
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