1,721,001 research outputs found
Le cellule staminali mesenchimali in Ortopedia. Quali, come, perché
Full text linkLa biologia ossea e le cellule staminali sono sempre state intimamente legate fin dagli inizi della medicina sperimentale. Questo già molto tempo prima che il termine di Medicina Rigenerativa divenisse abusato nella letteratura. Le cellule staminali presenti nell’osso sono state studiate approfonditamente ed in particolare la contemporanea presenza di due linee cellulari come l’ematopoietica e l’osteogenica ha sempre raccolto l’interesse della scienza. A tale riguardo il trapianto di cellule staminali ematopoietiche prelevate dal midollo osseo ed espanse in vitro rappresenta una delle maggiori innovazioni scientifiche nel campo della biologia applicata alla terapia. Dopo questo successo l’idea di poter utilizzare il prelievo di cellule mesenchimali per il trattamento delle patologie ossee ha trovato un nuovo impulso e il recente concetto di “nicchia” ha spinto ulteriormente avanti la nostra comprensione del funzionamento delle cellule rendendo possibile l’inizio di studi mirati al trattamento delle condropatie degenerative, delle necrosi epifisarie, l’osteoporosi e le mancate guarigioni delle fratture
Le protesi composite in chirurgia ortopedica [Allograft-prosthetic composites in orthopedic surgery]
No full textA allograft-prosthetic composite is a method used for reconstruction of great loss of metaepiphyseal bone substance in prosthetic revisions, in posttraumatic loss of substance, and in oncologic orthopedic surgery. Composite technique is a combination of a massive allograft with a conventional joint prosthesis. The bone graft allows both the restoration of an appropriate metaphyseal bone stock, and a valid reinsertion of the tendon structures of the host. The prosthetic component warrants a rapid functional recovery, with a joint surface which is stable in time. The authors describe the surgical technique of prosthetic composites at the level of the proximal femur and the proximal tibia. Both anatomical locations have shown a greater functional advantage with this method than with the use of megaprosthesis after resection. The possibility of obtaining any valid insertion of the tendon of the gluteus muscles at the level of the hip allows the restoration of active abduction; at the proximal tibia, the anchorage of the patellar tendon warrants active knee extension. In extra-articular resections of the knee in oncologic surgery, prosthetic composite is a method of choice because it prevents the arthrodesis of the knee, and allows a functional reconstruction of the joint through the implant of a massive graft of the proximal tibia comprehensive of the extensor apparatus associated to a conventional long-stem prosthesis
Minimally invasive techniques for treatment of metastatic cancer
No full textMany percutaneous image-guided ablative techniques have been used in the treatment of cancer-related bone metastases. These techniques are rapidly becoming a focus in the palliative and curative treatment of patients with both benign and malignant bone cancer.In this article we will briefly review the principles of radiofrequency ablation and our experience with this technique, including its use in combination with surgery; we will also discuss other minimally invasive techniques such as cryoablation and osteoplasty in the treatment of bone metastases
Treatment of non-unions of long bones with bone marrow alone or combined with platelet rich plasma or recombinant bone morphogenetic protein 7 (OP 1). An ongoing observational study
No full textTreatment of non-unions of long bones in the last years has seen the new chance of BMP augmentation. We had already treated difficult and recalcitrant non-unions with Concentrated Bone Marrow alone or associated with Platelet Derived Growth Factor (PDGF). The availability of the Bone Morphogenetic Protein 7 (BMP 7, OP 1) allowed us to compare the results of both treatments. We have now 40 cases from February 2001 to March 2006. Seven non unions affected the humerus, 30 non unions affected the lower limb, 18 cases the femur, 14 cases the tibia and one an attempted subtalar arthrodesis. The average age was 30 years (16-65). In five cases we used the bone marrow with a percutaneous technique with a 60% healing success. The two failures of this technique were in the same patient. In 35 cases we used open surgery and added bone graft plus PDGF and Bone Marrow in 16 cases, OP 1 alone in 16 cases and Bone Marrow plus OP1 in the last 3 cases. The healing rate of all groups was similar (87% vs 87% vs 100%). The higher result of the last treatment (Bone Marrow + OP 1 ± PDGF) was only on three patients and should be further evaluated. The patients treated with OP 1 experienced a greater number of previous surgeries (>3), still the BMP-7 proved to be effective in these cases. We suggest that surgeons should take into account the use of BMP-7 that proved to be effective in selected , previously failed patients for non unions and that adding Concentrated Bone Marrow might improve these already impressive results
L’organizzazione della Banca dei tessuti e del Centro di conservazione del tessuto osseo della Regione Toscana
No full textL’organizzazione della Banca dei tessuti e del Centro di conservazione del tessuto osseo della Regione Toscan
Riabitazione degli innesti spongiosi e tecniche di stimolazione [Bone allograft rehabilitation and growth factors]
No full textBone regeneration is based upon the three components of osteoconduction, osteoinduction and osteogenesis. During last years several bone substitutes have been developed to obtain a graft with ideal osteoconductive capabilities. Osteogenesis too has been emphasized with the progress of tissue engineering. Osteoinduction and the intrinsic osteoinductive properties of native bone have been already stressed by the historical works of Marshall Urist in 1965 about demineralised bone matrix (DBM). Only 20 years later the genetic sequences of the bone morphogenetic proteins (BMP) were identified and classified with the identification of a number of different BMPs whose precise role in the osteoinduction process is still extensively studied and not well defined. But experimental and preclinical studies have shown also that the BMPs are not playing alone on this stage. A lot of proteins secreted by the cells are implied in the process of healing and new bone formation; to these factors has been generically assigned the term of growth factor and an increasing number of these have been identified and used in experimental studies. The more debated are the transforming growth factor beta (TGF-β), the fibroblast growth factor (FGF), the insuline-like growth factor (IGF) and the platelets derived growth factors (PDGF). Obviously these are only some of the variety of factors that participate together with BMPs in a normal healing process
Salvage of failed osteosynthesis of proximal femural fractures and complex knee fractures with modular megaprostheses.
No full textSalvage of failed osteosynthesis of proximal femural fractures and complex knee fractures with modular megaprostheses
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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