We have used free forearm flaps for closure of various intraoral and oropharyngeal defects after radical ablation of tumors. A problem remained, however, in that split-thickness skin grafts required to close the forearm defect had to be obtained from other areas. To avoid this disadvantage, we de-epithelialized forearm flaps and the donor defects were closed with the split-thickness skin obtained from flap de-epithelialization. As a result of this procedure, unnecessary scarring has been avoided and postoperative management has been simplified. Such complications as flap loss, fistulae, or scar contracture have not occurred with greater frequency than is seen in normal circumstances. The de-epithelialized forearm flap procedure is explained. Histological findings concerning the de-epithelialized forearm flap are described, and the advantages of this method stated.

Adult↗

PubMedDate not supplied

Dual free flap transfer using forearm flap for mandibular reconstruction.

To reconstruct a composite mandibular defect, we have simultaneously transferred a vascularized bone graft or osteocutaneous flap together with a forearm flap. The radial forearm flap, being thin, pliable, and having a long vascular stalk, served as mucosal lining and/or an interpositional flap acting as a vascular bridge. Between 1982 and 1989, we used this procedure in 17 patients with a mandibular defect or deformity which developed following treatment of oral cancer. Our clinical experience has demonstrated that this dual free tissue transfer has many advantages. It is useful for obtaining a good alveolar ridge in patients with a composite mandibular defect. It is applicable in cases where only a single pair of recipient vessels are present and may be useful when the recipient vessels are positioned some distance from the defect.

Adult↗

PubMedDate not supplied

In vivo microdialysis studies of pineal and ocular melatonin rhythms in birds.

Pineal and retinal melatonin has an important role in the control of avian circadian rhythms. In order to study the mechanisms of circadian rhythms of melatonin synthesis in the pineal and in the eye, in vivo microdialysis was applied to these organs. In both pigeons and Japanese quails, pineal and ocular melatonin levels were high during the dark and low during the day under light-dark (LD) cycles. These rhythms persisted under constant dim light (LLdim) conditions indicating the circadian nature of pineal and ocular melatonin release. Light has two effects on melatonin synthesis. One is acute inhibition of melatonin synthesis and the other is entrainment of circadian melatonin rhythms. We have examined photoreceptors mediating these effects in the pigeon. The results have indicated that the eyes are not involved in light-induced suppression and photic entrainment of pineal melatonin release, and pineal photoreceptors themselves are likely to mediate these effects. Concerning ocular melatonin, retinal photoreceptors seem to mediate light-induced suppression and photic entrainment and no evidence supporting mediation of extraretinal photoreceptors was obtained. Because dopamine is implicated in retinal melatonin synthesis, we measured dopamine and melatonin release simultaneously from the eye of pigeon. In contrast to melatonin rhythms, dopamine increased during the day and decreased during the dark. This antiphase relationship between melatonin and dopamine persisted in LLdim, suggesting an interaction between these two rhythms. The results of an intraocular injection of dopamine or melatonin in the phase of melatonin and dopamine rhythms indicated that the interaction is required for maintaining the antiphase relationship between the two rhythms.

Animals↗