Biomedical subjects

M Gebhart

Publications and source records attributed to M Gebhart.

40 records · Page 3Linked to original sources

PubMedDate not supplied

[Ewing's sarcoma: literature review and presentation of 4 cases].

Ewing's sarcoma occurs most often in young males of caucasian type and affects the medio-diaphysis of a long bone of the lower extremity, the pelvis and the humerus. Radiologically there is bone destruction, onion skin appearance, a Codman triangle and extension into the surrounding soft tissues. Microscopically, this tumor is composed of small round cells and it can be differentiated from non Hodgkin lymphoma, metastatic neuroblastoma and embryonal rhabdomyosarcoma. Recent immunological studies suspect a neuroectodermal origin. Ewing's sarcoma growths rapidly and spreads to lung and other bone locations. Without treatment, survival at 5 years is less than 5%. The actual therapeutic approach is multidisciplinary including surgery, chemotherapy and if necessary radiotherapy. With this approach actual survival rates at 5 years reaches 75%.

Adolescent↗

PubMedDate not supplied

[Osteoradionecrosis at the level of coxo-femoral articulation in the adult].

Two cases of either cervical or acetabular osteoradionecrosis were described. One patient had endoprosthetic replacement of the hip, the other did not receive any surgical treatment. Regarding the literature, osteoradionecrosis occurs in 0.3 to 4% of the irradiated bones. Histologically there is a destruction of the bone by direct toxicity of the radiation and by destruction of the vascular supply. The threshold of irreversible bone destruction is 30 Gy. Fractures are epiphenomenons of osseous radionecrosis. The diagnosis can be suspected either by radiographies or by bone scans. Sometimes a bone biopsy is necessary to differentiate between bone necrosis, bone metastasis and eventually a radiation-induced sarcoma of the bone. If the osteoradionecrosis affects the acetabulum, even in the case of a stress fracture without acetabular protrusion of the femoral head, no surgical treatment is recommended. Weight bearing is avoided and spontaneous resolution occurs in most cases. If, on the other hand, there is a fracture through the femoral neck, hemiarthroplasty or total joint replacement is the treatment of choice. Total joint replacement is also recommended in case of an extensive radiation induced coxopathy.

Acetabulum↗

PubMedDate not supplied

Complete fibular regeneration following removal of the fibula for bone grafting.

Major bone defects may be reconstructed by either vascularized or not vascularized fibula grafts. No much attention is done so far to the donor site. This article emphasizes on an interesting observation, where almost total regeneration of a subperiosteally harvested fibula graft occurred within the first three postoperative months.

Bone Regeneration↗

PubMedDate not supplied

In vitro characterisation of soft tissue tumor chemosensitivity.

BACKGROUND: The benefit of performing chemotherapy on soft tissue sarcomas remains controversial. The present study deals with the in vitro characterisation of the influence of 3 antitumoral agents on the growth of 8 sarcoma cell lines. MATERIALS AND METHODS: Cell growth was monitored by means of the MTT colorimetric assay, which was further validated by a direct cell counting method. The three drugs tested included doxorubicin (ADR), cisplatin (DDP) and dacarbazine (DTIC). ADR was tested at 10(-5) M, 10(-6) M and 10(-7) M; DDP at 10(-5) M, 10(-6) M and 10(-7) M; and DTIC at 10(-3) M, 10(-4) M and 10(-5) M. A combination of the three drugs was also tested in order to ascertain whether a synergistic effect on cell growth inhibition could be obtained. A potential antineoplastic agent-induced influence on cell growth was determined 3 days after the addition of the diverse drug(s) to the culture media. The cell concentration was specifically adapted to each cell line. The 8 cell lines included 3 leiomyosarcomas, 1 malignant mixed Müllerian tumour, 3 rhabdomyosarcomas and 1 fibrosarcoma. RESULTS: The results show that of the three drugs tested, ADR was the most efficient in terms of the level of cell growth inhibition obtained and the number of cell lines whose growth was significantly inhibited. Of the three drugs, the least active was DDP. A significant synergistic effect was observed when the three drugs were added together to the culture medium. This synergistic effect was evident at the lowest doses tested for each drug. Whatever the histopathological type, the 8 cell lines exhibited a wide range of response to chemotherapy. CONCLUSIONS: The present study shows that the inhibition induced by 10(-7) M ADR, 10(-7) M DDP and 10(-5) M DTIC on sarcoma cell line growth is significantly more efficient than if each agent is tested individually. The in vitro methodology used here fits in with clinical reality because it enables sarcoma cell heterogeneity to be taken into account.

Antineoplastic Agents↗