Synergistic effect of IGF-I and TGF-beta1 on fracture healing in rats: single versus combined application of IGF-I and TGF-beta1.

During the last few decades, knowledge about growth factors and their function has increased. However, little is known about the interaction of these factors during bone growth and fracture healing. In vitro studies have shown a higher rate of cell proliferation and cell metabolism after the use of IGF-I and TGF-beta1 in combination, as compared to the single use of these factors. The purpose of this study was to investigate a possible synergistic effect of these growth factors in vivo, using a fracture model. A midshaft fracture of rat tibia (n = 84) was intramedullary stabilized with poly(D,L-lactide)-coated or uncoated titanium K-wires. The growth factors IGF-I and TGF-beta1, singly or in combination, were incorporated in the coating and continuously released during fracture healing. 28 days after fracture, we performed mechanical tests and histomorphological analyses. We found a greater stimulating effect of IGF-I on fracture healing than of TGF-beta1. The combined application of both growth factors resulted in a significantly higher maximum load and torsional stiffness than the use of only one of them. The histomorphometric analyses showed an increase in remodeling of the fracture callus in this group with less cartilaginous and more mineralized tissue than in the other groups. Both growth factors seem to have a synergistic effect on fracture healing in this model.

Complete spontaneous resolution of severe nonimmunological hydrops fetalis with unknown etiology in the second trimester--a case report.

The incidence of nonimmunological fetal hydrops is between 1 in 1500 and 1 in 4000. Overall mortality for this condition is about 80%. This report describes a case of prenatally diagnosed hydrops fetalis with severe generalized edema, ascites and pleural effusion of unknown origin at 19 weeks of gestation. No symptoms were found of infections or anemia, no variabilities were observed in fetal blood analysis or in karyotyping. All signs of hydrops resolved completely after 6 weeks without treatment. The pregnancy continued with normal fetal development; labor was induced at 41 weeks of gestation. After vaginal delivery with vacuum extraction the child was completely healthy and demonstrated no signs of remaining hydrops fetalis or any other pathological parameters except an uncritical atrial septal defect type II which healed without any complications within 3 months post delivery.