Transplantation of sheep embrionic stem cells in cartilage lesions: preliminary observations

Source: OAI


Once damaged, joint cartilage never completely regenerates. This is due to absence of vascularisation, slow cellular
turnover and impossibility for inflammation mediators to reach the cartilage lesion. Even small lesions involve
alteration in joint functionality and can cause invalidating pathologies. Treatment is complex and the surgical
techniques used to repair the joint surfaces do not give satisfactory and durable results because the new tissue produced is fibrous cartilage. The aim of this study is to evaluate whether ovine embryonic stem cells transplanted in experimental lesions can differentiate into chondrocyte cells and if the new cartilage is of ialine type. For that purpose, we used the ovine species. The evaluation of reparative tissue was performed 1, 2 and 6 months after cell inoculation with histological, immunohistochemical and in situ hybridization methods. Bare lesions and Tissucol-implanted lesions were used as controls. Results confirm the stem origin of the reparative tissue with stem cells differentiating prevalently into chondrocytes and rarely into fibrocytes.

Download full-text


Available from: Stefano Rocca, Oct 06, 2015
21 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have previously reported that P-glycoprotein (Pgp)-overexpressing multidrug resistant (MDR) osteosarcoma cells were functionally more differentiated than their parent cells. The present study showed that in the parent cells, the actin filaments were sparsely distributed or were diffusely spread throughout the cytoplasm, whereas the MDR osteosarcoma cells exhibited a remarkable increase in well-organized actin stress fibers. Furthermore, dihydrocytochalasin B, a specific inhibitor of actin polymerization, dramatically disrupted this network of stress fibers, increased the intracellular accumulation of doxorubicin (DOX) and modified the resistance against DOX. These results indicate that the organization of actin filaments associated with cellular differentiation may be involved in the expression of Pgp function in the MDR osteosarcoma cells.
    Cancer Letters 05/1998; 126(1):75-81. DOI:10.1016/S0304-3835(97)00539-9 · 5.62 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Axial skeletal osteosarcomas were evaluated retrospectively in 116 dogs. Thirty-one tumors occurred in the mandible, 26 in the maxilla, 17 in the spine, 14 in the cranium, 12 in the ribs, 10 in the nasal cavity and paranasal sinuses, and 6 in the pelvis. Medium-sized and large dogs were most commonly affected. Females outnumbered males 2.1:1, but this varied with tumor location. The mean age was 8.7 years. Osteosarcomas of the rib occurred in significantly younger dogs (mean age, 5.4 years) than osteosarcomas at any other axial skeletal site. Pulmonary metastasis was diagnosed radiographically in 11.1% of the dogs. The median survival for dogs treated surgically was 22 weeks, the 1-year survival was 26.3%, and the 2-year survival was 18.4%. The tumor recurrence rate was 66.7%. Most dogs (79.6%) died or were euthanatized for problems associated with the primary tumor.
    Veterinary Surgery 07/1992; 21(4):304-10. DOI:10.1111/j.1532-950X.1992.tb00069.x · 1.04 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Naturally occurring skeletal osteosarcomas in a series of 144 untreated dogs were found especially to involve the ends of the long bones of the forelimbs and affected predominantly older male dogs of giant and large breeds. Most tumors were large and partially necrotic and had extended into soft tissues. Of 12 host and tumor characteristics tested in the first part of the study, tumor diameter and volume were significantly associated with the presence of pulmonary metastases at autopsy. The second part of the study revealed that extension of the tumor into the soft tissues and localization of the tumor in the hind legs were associated with a poor prognosis, whereas the fibrosarcomatous type of tumor was associated, as in man, with a favorable prognosis. An association between the 12 characteristics tested was found in 11 of 78 combinations at the 5% level and in 5 combinations at the 1% level. Affected giant dogs were generally younger than affected small and medium-sized dogs. Especially in giant dogs, the osteosarcomas involved the long bones and were of relatively large diameters. The sarcomas in female dogs were larger in volume than those in males. Pure osteoblastic osteosarcomas were generally smaller than combined (chondroblastic and fibroblastic) osteosarcomas. Peritumorous lymphocytes and plasma cells were present in 50% of the dogs, especially in small and young dogs. When compared with a reference population, great Danes, rottweilers, German shepherds, and boxers were found to be overrepresented in the osteosarcoma group.
    JNCI Journal of the National Cancer Institute 04/1979; 62(3):537-45. · 12.58 Impact Factor
Show more