Showing papers by "Ichiro Ono published in 1997"

Enhancement by bFGF of osteogenesis induced by rhBMP-2 in rats

Abstract: Subcutaneous implantation of bone morphogenetic protein (BMP) combined with a fibrous glass membrane (FGM) induces cartilage formation in the entire inner area of the membrane within 2 wk. It has been hypothesized that a tight FGM network (1 microm exclusion size) provides immature cells with spaces for penetrating into the membrane, but not for vascular formation, at least until 2 wk. To test this hypothesis, basic fibroblast growth factor (bFGF), known to be a potent stimulant of capillary formation, was applied to the implant. BMP was combined with FGM in the presence or absence of bFGF, and then implanted subcutaneously into the backs of rats. The bFGF-supplemented implant caused 1.3 times higher alkaline phosphatase activity and 3 times higher calcium contents at 2 wk, whereas type II collagen contents decreased, thus indicating that bFGF enhances bone formation in BMP/FGM implants. These results suggest that bFGF induces faster and stronger invasion of capillaries into the FGM and destroys its tight network, resulting in acceleration of the ossification process.

Role of transforming growth factor-beta 1 in fibroblasts derived from normal and hypertrophic scarred skin.

Abstract: In order to elucidate the effect of transforming growth factor beta 1 (TGF-beta 1) on normal dermal fibroblasts (NDF) and on fibroblasts derived from hypertrophic scar (HSF) tissue, we compared proliferation, the levels of TGF-beta 1 protein and mRNA, the activity of type-I collagen synthesis and collagenase, and the response to recombinant human (rh) TGF-beta 1 in cultures of both types of cells which had been simultaneously collected from the same patients. We also studied the effects of anti-TGF-beta 1 antibody on the proliferation of these two types of fibroblasts in culture. In spite of the fact that the growth rate of HSF was higher than that of NDF, NDF proliferation was more sensitive to the concentration of rhTGF-beta 1. With respect to rates of synthesis, the results obtained in both groups revealed that the production of type-I collagen was higher and collagenase activity was lower in culture supernatants of HSF. However, the addition of rhTGF-beta 1 resulted in a decrease in the collagenase/collagen ratio in NDF, but failed to induce any change in this ratio in HSF. In addition, the production of TGF-beta 1 and the expression of TGF-beta 1 mRNA in HSF were greater than in NDF. Furthermore, anti-TGF-beta 1 antibody reduced the rate of growth of HSF. These results suggest that HSF are able to produce TGF-beta 1, resulting in enhanced proliferation of these cells as well as in a rapid synthesis of type-I collagen through an autocrine mechanism which may lead to hypertrophic scarring.

Reconstruction of defects of the entire vermilion with a buccal musculomucosal flap following resection of malignant tumors of the lower lip.

Abstract: We reconstructed a defect of nearly the entire lower vermilion using a buccal musculomucosal flap following resection of a malignant tumor of the lower lip and obtained satisfactory results. The buccal musculomucosal flap was semi-spindle shaped and pedicled at the angle of the mouth. A flap measuring as much as 1.5 cm in width and 5 cm in length could be raised while ensuring that fibers of the buccinator muscle extended over its entire length. Using this technique, it was possible to reconstruct a wide defect following tumor resection and removal of almost the entire lower vermilion by means of only a transposition of a unilateral buccal musculomucosal flap after about one-quarter of the lower lip had been excised and sutured primarily. Reconstruction with this technique is a two-stage operation, and a secondary minor touch-up operation is performed on the angle of the mouth at the same time as repair of the dog-ear of the pedicle. Advantages of this technique are that food can be taken orally soon after the operation, hemodynamics in the flap are maintained stably because the flap contains fibers of the buccinator muscle, and the vermilion is given a natural eminence. In addition, postoperative drooling is minimized, and sensation returns to the vermilion within the early postoperative period. Based on these advantages, we think our technique should be the first choice for carrying out reconstruction of defects that are located mainly in the lower lip vermilion because this is a safe and reliable method with which we performed 12 cases of vermilion reconstruction without flap necrosis and with satisfactory aesthetic and functional results.

Primary maxillary reconstruction after radical maxillectomy using a combined free flap and secondary dynamic suspension.

Abstract: We report a case of maxillary reconstruction aimed at optimizing facial contour, oral function, and facial animation after radical maxillectomy. In the first stage, using combined latissimus dorsi serratus anterior flaps attached with ribs, we performed a three-dimensional restoration for midface defects. In the second stage, we performed dynamic reconstruction of the nasolabial fold and upper lip using a temporal muscle transposition. As a result, the upper lip was able to be elevated as much as 10 mm when the patient clenched his teeth, and the outcome was judged to be both aesthetically and functionally satisfactory.