Biomedical subjects
Publications and source records attributed to L Sedel.
In a case of giant cell tumour of bone, electron microscopy revealed filamentous inclusions within the nuclei of all the giant cells. Although not invariably present in such tumours, their similarity with the nucleocytoplasmic inclusions seen in osteoclasts in Paget's disease is underlined. This raises interesting questions as to their nature and the histogenesis of these disorders.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Explore the source record for details and available documents.
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Large bone defects are still a challenge to orthopedic surgeons. In this study, a massive bone defect with a clinically relevant volume was efficiently reconstructed by transplanting an engineered bone in which mesenchymal stem cells (MSCs) expanded in autologous serum (AS) were combined with a porous scaffold. In the first step, we established that the way in which the MSCs are distributed over the scaffold affects the ultimate bone-forming ability of the transplant: constructs consisting of a natural coral scaffold and a pseudo-periosteal layer of MSCs surrounding the implant (coral-MSC3D) formed significantly more bone than constructs in which the MSCs were distributed throughout the implant (p = 0.01). However, bone healing occurred in only one sheep, owing to the high resorption rate of natural coral scaffold. To overcome this problem, constructs in which MSCs were combined with a porous coralline-based hydroxyapatite (CHA) scaffold having the same architecture as natural coral but a lower resorption rate were prepared. After their implantation, these constructs were found to have the same osteogenic potential as autologous bone grafts in terms of the amount of newly formed bone present at 4 months (p = 0.89) and to have been completely replaced by newly formed, structurally competent bone within 14 months. Nevertheless, although the rate of bone healing was strikingly improved when CHA-MSC3D constructs were used (five of seven animals healed) as compared with the coral-MSC3D construct (one of seven healed), it was still less satisfactory than that obtained with autografts (five of five healed).
The results of a series of 86 cases with a follow-up of 2 to 23 years are presented. Treatment was surgical in all cases except in spine and pelvis. 24 cases were treated by curetage, 51 by resection in some cases after curetage. Block resection nearly suppresses the recurrences and, when used as the first treatment, may avoid secondary malignant degeneration.
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Twelve sheep were used in an experimental study on bone healing. The first metatarsal was fractured and fixed either by plating without compression or by intramedullary nailing. Three months later, the animals were sacrificed, the fractured bone removed and the mechanical properties of the callus were assessed by resistance to rupture, tangential strain measurement, the energy required for rupture, module of elasticity and the moment of inertia. It was concluded that callus was superior quantitatively as well as qualitatively after nailing. The mechanical properties of the callus wwere related to its degree of mineralisation.
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