Expression patterns of Notch receptors and their ligands in human osteoarthritic and healthy articular cartilage.

Notch pathway plays a pivotal role in cell fate determination. There is much interest surrounding its therapeutic potential, in osteoarthritis, but the expression profile of Notch-related molecules, as well as their relation with cartilage pathological parameters, remains unclear. The purpose of our study is to analyze the expression pattern of Notch family members, type II and type I collagen, in normal (healthy) and osteoarthritic human knee cartilage. Osteoarthritic cartilages were obtained from 3 patients undergoing a total knee replacement. Macroscopically normal cartilage was dissected from 3 human knees at the time of autopsy or surgery. Immunohistochemical staining was performed using Notch1,2,3 and 4, Delta, Jagged, type II collagen and type I collagen antibodies. In healthy cartilage, type II collagen was abundantly expressed while type I was absent. This latter increased proportionally to the osteoarthritic grade. Type II collagen expression remained intense in osteoarthritic cartilage. In healthy cartilage as well as in cartilage with minor lesions, Notch family member's proteins were not or just weakly expressed at the surface and in the cells. However, Notch molecules were over-expressed in osteoarthritic cartilage compared to healthy one. This expression pattern was different according to the cartilage zone and the severity of OA. Our data suggest that Notch signaling is activated in osteoarthritic cartilage, compared to healthy cartilage, with a much more abundant expression in the most damaged areas.

Endometrial stromal sarcoma presenting as a cystic abdominal mass.

Endometrial stromal sarcoma (ESS) is rarely localized in extrauterine sites if metastasis or local extension of the primary uterine tumour are excluded, and diagnosis can be delayed because of the unusual site. We report a case of abdominal ESS in a 45-year-old woman who presented with an abdominal complaint. Ultrasound of the abdomen showed a large multiloculated cystic mass. The complete excision of the tumour revealed ESS arising in endometriosis. The tumour expressed hormonal receptors and the patient was administered hormonal therapy. ESS has a better prognosis than the sarcoma that is part of differential diagnosis, and is associated with endometriosis in about one-half of cases.

Complete mutation screening and haplotype characterization of BRCA1 gene in Tunisian patients with familial breast cancer.

Breast cancer, the most commonly diagnosed cancer in women, is the second leading cause of cancer death in women worldwide. To investigate the contribution of BRCA1 gene mutations to familial breast cancer in Tunisia, 32 unrelated patients who had at least one first degree relative affected with breast and/or ovarian cancer were analysed. BRCA1 mutation analysis was performed by DNA sequencing of all BRCA1 exons. We identified four different BRCA1 frameshift mutations: c.4041delAG, c.2551delG and c.5266dupC already been described and one novel mutation, c.211dupA, observed in two unrelated families. C.5266dupC has previously been found among Jewish Ashkenazi and Eastern European populations. Our study describes it in Arabic/Berber population. Five out of thirty two familial cases had deleterious BRCA1 mutations. Fifteen additional cases carried unclassified variants (UV) or single nucleotide polymorphisms (SNPs). Our study is the first molecular investigation on the role of BRCA1 in hereditary breast cancer in North Tunisia.

Osteosarcoma with rhabdomyosarcomatous component or so-called malignant mesenchymoma of bone.

BACKGROUND: Primary malignant mesenchymoma of the bone is a rare neoplasm consisting of two or more unrelated malignant mesenchymal components. The literature reports fewer than 20 cases, most of which were composed of osteosarcoma and liposarcoma. OBSERVATION: We report an exceedingly rare case of primary malignant mesenchymoma of bone composed of rhabdomyosarcoma, osteosarcoma, and a minor chondrosarcoma component, arising in the right proximal humerus of a 15-year-old girl. The rhabdomyosarcomatous component was present in the initial biopsy and persisted in surgical specimen following chemotherapy. CONCLUSION: Effect of chemotherapy is enigmatic since rhabdomyosarcomatous component could appear, persist or disappear after chemotherapy according to literature.