[Clinical effect of free thoracodorsal artery perforator flap in reconstructing large scar on the facial subunit].

Objective: To explore the clinical effect of free transplantation of thoracodorsal artery perforator flap in reconstructing large scar on the facial subunit. Methods: From April 2014 to March 2018, 7 patients with large facial scar were admitted to Ningbo NO.6 Hospital, including 3 males and 4 females, aged from 31 to 49 years, 4 with frontal involvement and 3 with chin and neck. Color Doppler ultrasound was used for the positioning of the thoracodorsal artery perforating vessel, and scar resection was performed according to the principle of facial subunit repair. The wound area was 8 cm×6 cm-21 cm×8 cm, and the wound was repaired with the free thoracodorsal artery perforator flap in the area of 9 cm×7 cm-22 cm×9 cm. The donor site was closed directly by suturing. The consistency of the location of the perforating vessel explored during the operation with its preoperative positioning and the flap survival were recorded. The color, texture, and appearance of the flap and the healing condition, scar formation, and function of the donor area were observed during follow-up. Results: The locations of the perforating vessels of 7 patients explored during the operation were consistent with those positioned by color Doppler ultrasound before the operation. All the flaps of the 7 cases survived successfully after operation. Postoperative follow-up of 12-18 months showed that the flap color was similar to the surrounding skin of the recipient area, with soft texture and no obvious contracture. Slight bloated appearance was observed in the flaps of 4 cases. All the 7 patients had postoperative healing of the flap donor site without obvious scar hyperplasia or influence on shoulder joint function. Conclusions: The anatomy of the perforating vessel of the thoracodorsal artery perforator flap is relatively constant and the flap can be cut in large area with soft texture, good appearance, and concealed donor area, which is a good choice for reconstructing large scar on the facial subunit.

A photolysis-triggered heme ligand switch in H93G myoglobin.

Resonance Raman spectroscopy and step-scan Fourier transform infrared (FTIR) spectroscopy have been used to identify the ligation state of ferrous heme iron for the H93G proximal cavity mutant of myoglobin in the absence of exogenous ligand on the proximal side. Preparation of the H93G mutant of myoglobin has been previously reported for a variety of axial ligands to the heme iron (e.g., substituted pyridines and imidazoles) [DePillis, G., Decatur, S. M., Barrick, D., and Boxer, S. G. (1994) J. Am. Chem. Soc. 116, 6981-6982]. The present study examines the ligation states of heme in preparations of the H93G myoglobin with no exogenous ligand. In the deoxy form of H93G, resonance Raman spectroscopic evidence shows water to be the axial (fifth) ligand to the deoxy heme iron. Analysis of the infrared C-O and Raman Fe-C stretching frequencies for the CO adduct indicates that it is six-coordinate with a histidine trans ligand. Following photolysis of CO, a time-dependent change in ligation is evident in both step-scan FTIR and saturation resonance Raman spectra, leading to the conclusion that a conformationally driven ligand switch exists in the H93G protein. In the absence of exogenous nitrogenous ligands, the CO trans effect stabilizes endogenous histidine ligation, while conformational strain favors the dissociation of histidine following photolysis of CO. The replacement of histidine by water in the five-coordinate complex is estimated to occur in < 5 micros. The results demonstrate that the H93G myoglobin cavity mutant has potential utility as a model system for studying the conformational energetics of ligand switching in heme proteins such as those observed in nitrite reductase, guanylyl cyclase, and possibly cytochrome c oxidase.