engleski

Hypertrophic Callus Formation In Patients With Severe Traumatic Brain Injury - An In Vitro Model

Patients with severe traumatic brain injury (TBI) and fractures of long bones and/or large joints often exert enhanced osteogenesis with hypertrophic callus formation and/or heterotopic periarticular ossifications. The reasons for this phenomenon are still unknown. Humoral factors of local and systemic genesis probably play an important role. We have examined this in cultures of human bone cells by adding human sera taken from 3 groups of patients as well as from healthy subjects: group I (patients with TBI and fractures of long bones), group II (TBI only), group III (fractures only), group IV (healthy subjects). The sera have been taken weekly during the first 3 months after injury. Monolayer cultures were seeded and the sera of the 4 groups added ; 3H-thymidine incorporation was measured with the Beta-counter. As most of the growth factors are bound to heparin in serum, heparin bound components have been removed by heparin-sepharose and 3H-thymidine incorporation was performed. Migration of bone cells from the bone particle into the culture medium and development of a gentle monolayer cell culture at the bottom could be seen. The sera which were modified by heparin-sepharose showed a different growth stimulating activity of the sera, indicating that the heparin bound factors are responsible for - or are at least involved - in this phenomenon. Tissue cultures have been obtained by seeding human bone cells on decalcified bovine bone matrix ; the reaction of the pooled sera of the different groups of patients on the growth of the bone cells was examined under microscope. In those cultures to which the sera of patients of groups I or II (patients with TBI) were added an intensive synthesis of new bone material could be noticed during the first 4 weeks in vitro, resembling the phenomenon of heterotopic ossifications and hypertrophic callus formation in patients with TBI observed in the x-rays in vivo.

nije evidentirano

nije evidentirano