Localization and expression of R-cadherin in skeletal muscle following nerve injury.

Rats in which the sciatic nerves were cut were divided into two groups: animals with nerve sutured and animals with nerve not sutured. In the unsutured group, the levels of R-cadherin expression increased and then decreased to values lower than those of controls. In the sutured group, the levels of R-cadherin expression increased and then decreased to almost control values. These results suggest that R-cadherin plays some role in cells of normal and regenerating muscles.

Use of facial artery musculomucosal flap for closure of soft tissue defects of the mandibular vestibule.

We present the use of the inferiorly based facial artery musculomucous (FAMM) flap to repair a defect of the mandibular vestibule, and discuss the advantages and disadvantages of this procedure. The FAMM flap an effectively cover defects of the mandibular vestibule and other regions of the oral cavity, and its softness, toughness, and minimal shrinkage allow for the use of dental prostheses.

Molecular response to ischemia-reperfusion of rat skin: study of expression of p53, p21WAF-1, and Bax proteins, and apoptosis.

The authors investigated the expression of p53, p21WAF-1, and Bax proteins, and apoptosis to elucidate the cellular response to ischemia-reperfusion of the skin. The rat left lower limb was dissected at the inguinal region retaining the bone and femoral vessels, and the vessels were clamped to produce an ischemic condition. After 6 hours the clamps were removed, and the plantar skin was resected at various times up to 72 hours after reperfusion. Five skin specimens were obtained at each time point from 5 rats. When a rat died during the study, additional rats were used until five specimens could be obtained from 5 rats at each time point. The expression of the three proteins was detected by Western blot analysis. The apoptotic cells were detected using the terminal deoxytransferase-mediated dUDP nick-end labeling assay. After reperfusion, the levels of p53 and p21WAF-1 were significantly higher in the ischemia-reperfusion rats compared with the sham-operated rats. However, the levels of Bax protein did not show a noticeable increase at any period. The apoptotic cells in both the epidermis and dermis were not evident compared with the sham skin, which were similar to those in the nontreated, normal skin. These results demonstrate that p53 and p21WAF-1 proteins accumulate after 6 hours of ischemia of the skin during reperfusion. Moreover, it is speculated that accumulation of these proteins plays an important role in the survival of the skin by inducing growth arrest of the cells, but not apoptosis.

The differential expression of N-cadherin in vascularized and nonvascularized nerve grafts: a study in a rat sciatic nerve model.

The authors investigated N-cadherin expression in vascularized and nonvascularized nerve grafts using a rat sciatic nerve model. The vascularized and nonvascularized nerve grafts were elevated, and then both nerves were sutured to the original site. At various periods after the operation, the entire graft was removed. N-cadherin expression was detected via Western blot analysis and histochemical staining using anti-N-cadherin antibody. In both grafts, the level of N-cadherin expression increased after the operation, but during postoperative weeks 6, 9, and 12, the level in the vascularized graft was significantly (p = 0.00023, 0.0018, and 0.0010, respectively) higher than that in the nonvascularized graft. At postoperative week 14, the level of both grafts returned to the control level. Histochemical findings showed that N-cadherin was expressed around the regenerated axons in both grafts, and the degree of regeneration was greater in the vascularized graft than in the nonvascularized graft. These results demonstrate that the expression of N-cadherin increases during the process of axonal regeneration in both grafts, and that the degree of the expression is augmented by vascularization of the nerve graft.

Detection of E-cadherin expression after nerve repair in a rat sciatic nerve model.

The authors investigated E-cadherin expression during nerve regeneration after nerve suture using the rat sciatic nerve model. Five rats were used during each postoperative period. E-cadherin expression was detected by Western blot analysis and immunofluorescent staining with an anti-E-cadherin monoclonal antibody. The level of E-cadherin expression was calculated as the amount relative to that found in normal control nerve. The level of E-cadherin expression was decreased at first, and then gradually increased. The maximum level of E-cadherin was 1.92 +/- 0.07 fold in the sutured nerve. The level of E-cadherin expression in the sutured nerve was significantly greater (p < 0.0001) than that of the normal control nerve from postoperative day 3 to 21, and that of sutured nerve returned to the control level by postoperative day 28. The immunofluorescent staining results indicated that E-cadherin expression was almost negative or decreased immediately after the operation, but the degree of expression increased gradually in Schwann's cells. The degree of E-cadherin expression was significantly greater than that of normal control nerves from postoperative day 7 to 14, and returned to the control level by postoperative day 21. These results demonstrate that E-cadherin expression increases during nerve regeneration, and the expression was observed mainly in Schwann's cells. The degree of E-cadherin expression may affect the rate of nerve regeneration.

The difference in E-cadherin expression between nonvascularized and vascularized nerve grafts: study in the rat sciatic nerve model.

BACKGROUND: We investigated the expression of E-cadherin during nerve regeneration after nonvascularized and vascularized nerve grafts. MATERIALS AND METHODS: We used the rat sciatic nerve model. E-cadherin expression was detected by Western blot analysis and immunofluorescent staining with anti E-cadherin monoclonal antibody. The level of E-cadherin expression was calculated as the amount relative to that of E-cadherin expression of normal control nerve. Furthermore, repair of the neural tissue structure was examined by toluidine blue staining. RESULTS: In both cases, the level of E-cadherin expression decreased at first, and then gradually increased. The maximum level was 1.61 +/- 0.066-fold in the nonvascularized nerve graft and 2.254 +/- 0.071-fold in the vascularized nerve graft. From the 1st to the 16th postoperative weeks, the level of E-cadherin expression in the vascularized nerve graft was significantly higher than that in the nonvascularized nerve graft. In the immunofluorescent staining, E-cadherin expression was almost negative or decreased immediately after the operation, but the degree of expression was gradually increased in Schwann cells. The degree of E-cadherin expression in the vascularized nerve graft was greater than that in the nonvascularized nerve graft. In toluidine blue staining, the velocity of tissue repair was more rapid in the vascularized nerve graft than in the nonvascularized graft. CONCLUSION: These results demonstrate that the E-cadherin expression of grafted nerve was increased during the nerve regeneration, and the expression was mainly observed in Schwann cells. Because the level of E-cadherin expression was significantly higher in the vascularized nerve graft than in the nonvascularized nerve graft, the level of E-cadherin expression may affect the rapidity of nerve regeneration.

Lip reconstruction of comparatively large defect including the commissure using remaining lip tissue: a modification of reconstructed method.

We present two reconstructed cases after malignant skin tumor of comparatively large defects of lip including the commissure using remaining lip tissue alone. After resecting a tumor including wedge-shaped full-thickness lip tissue, a full thickness oblique incision is made at the site 5 mm distant from the contralateral commissure. The rhomboid-shaped lower lip flap is created, transposed to the defect, and sutured with the defect margin, including the upper lip, to reconstruct the commissure. The cross lip flap is created at the contralateral side of the lower lip, 5 mm from the commissure, and the defect is closed with the crosslip flap. Although our method is applicable only to selected cases, we believe that it is useful in terms of maintaining symmetry of the lip and function of the commissure in the reconstruction of comparatively large defects including the commissure.

Experience with surgical treatment of hidradenitis suppurativa.

The authors report their experience with 23 sites of hidradenitis suppurativa, including cases with musculocutaneous flap repair, and discuss the surgical methods applied. Twenty-three sites in 19 patients with chronic inflammatory skin lesions were reviewed. The lesions were divided into two groups: The limited group was comprised of mild lesions, which appear isolated and have limited abscesses without sinus tract formations. The severe group was compromised of severe lesions, which included diffuse, multiple abscesses with severe sinus tract formation and fibrosis. Nine sites were limited and 14 sites were severe. After resecting the lesion, the defect was covered with a split-thickness skin graft (four sites were limited, nine sites severe), a musculocutaneous flap (five sites severe), primary closure (four sites limited), and a local skin flap (one site limited). In six sites in 6 severe-group patients, local recurrence occurred. The local recurrence rate differed significantly between the limited and the severe groups. The reason for this may be because the lesions in the limited group could be resected completely, whereas the lesions in the severe group were diffuse and total resection was sometimes difficult for various reasons. The method of surgical repair did not affect the local recurrence rate. In recurrent cases, four sites treated with skin grafting required further surgical treatment, and two sites treated with musculocutaneous flaps were controlled with oral antibiotics. In conclusion, sufficient resection of the lesion is the most important issue in treating follicular occlusion triad disease. In lesions that can be resected completely, the surgical procedure to cover the lesions should be selected to suit the size and site of the defect. However, in cases that cannot be resected completely, a musculocutaneous flap is recommended instead of a skin graft for enhanced postoperative management of the recurring wound, and its contribution to aesthetic and functional improvement.

Application of artificial dermis graft to correct a depression after tissue resection.

The authors present 7 cases of artificial dermis implantation to correct a depression after tissue resection. Four of the seven cases resulted from resection of a malignant tumor (N = 3) and from a benign subcutaneous tumor (N = 1). The other 3 cases were the result of temporal muscle harvest to reconstruct facial palsy. In 1 patient a mild degree of bone deformity also existed. The pieces of artificial dermis employed varied from 35 x 40 to 40 x 80 mm in size. In 5 patients two sheets were implanted, and in 2 patients three sheets were implanted. In 2 patients the dermis sheets were covered by a pedicled temporal fascial flap with a free split-thickness skin graft because whole skin was resected as a result of a malignant skin tumor. There was no postoperative infection or allergic reaction in any of the patients. In all cases there was no postoperative contracture, and the implanted area was soft. An adequate or acceptable thickness of subcutaneous tissue was obtained. Artificial dermis may be a useful option as implantation material to correct a depression after tissue resection, especially for wide and comparatively shallow depressions.