Impact of ultraviolet radiation on dermal and epidermal DNA damage in a human pigmented bilayered skin substitute

Our laboratory has developed a scaffold‐free cell‐based method of tissue engineering to produce bilayered tissue‐engineered skin substitutes (TESs) from epidermal and dermal cells. However, TES pigmentation is absent or heterogeneous after grafting, due to a suboptimal number of melanocytes in culture. Our objectives were to produce TESs with a sufficient quantity of melanocytes from different pigmentation phototypes (light and dark) to achieve a homogeneous color and to evaluate whether the resulting pigmentation was photoprotective against ultraviolet radiation (UVR)‐induced DNA damage in the dermis and the epidermis. TESs were cultured using different concentrations of melanocytes (100, 200, and 1,500 melanocytes/mm²), and pigmentation was evaluated in vitro and after grafting onto an athymic mouse excisional model. Dermal and epidermal DNA damage was next studied, exposing pigmented TESs to 13 and 32.5 J/cm² UVR in vitro. We observed that melanocyte cell density increased with culture time until reaching a plateau corresponding to the cell distribution of native skin. Pigmentation of melanocyte‐containing TESs was similar to donor skin, with visible melanin transfer from melanocytes to keratinocytes. The amount of melanin in TESs was inversely correlated to the UVR‐induced formation of cyclobutane pyrimidine dimer in dermal fibroblasts and keratinocytes. Our results indicate that the pigmentation conferred by the addition of melanocytes in TESs protects against UVR‐induced DNA damage. Therefore, autologous pigmented TESs could ensure photoprotection after grafting.     

A retrospective study of the role of radiotherapy in the treatment of soft-tissue sarcoma

One hundred and forty patients with soft-tissue sarcoma were seen between 1965 and 1974 and the pathology has been reviewed in 93 cases. One hundred and eight patients were treated radically. Their overall survival rate was 53% at 5 years and 41% at 10 years. Overall local control was 63% but primary local control varied considerably with treatment, being highest for those receiving surgery and post-operative radiotherapy. The poor prognosis of patients with paravertebral tumours is confirmed.     

Acromioclavicular joint reconstruction by coracoid process transfer augmented with hook plate

Background

Various techniques have been reported for the treatment of chronic acromioclavicular (AC) joint separation. The purpose of this study was to evaluate the results of surgical construction of coracoclavicular ligament using coracoid process transfer augmented with a hook plate fixation.

Materials and methods

Twenty-one patients treated with coracoid process transfer augmented with a hook plate fixation for chronic type III and V AC injuries were retrospectively analysed in 2003–2009. The age of the patients ranged from 23 to 58 years with an average age of 41.6 years. The patients were followed up clinically and radiographically, with an average of 33.0 months. Functional status and the ability to return to work were recorded during follow-up. Constant score and visual analogue scale (VAS) for pain were measured.

Results

The mean Constant score has increased from 70.9 points preoperatively to 90.7 points at follow-up. The mean VAS score has decreased from 4.7 preoperatively to 1.2 at follow-up. The average abduction was 172°, forward flexion was 170° and external rotation was 56°. There were 10 excellent results, 10 good results and one fair result. All patients had resumed their job or returned to original sport activity at mean 3.7 months postoperatively. No reduction loss was observed after plate removal and the final follow-up.

Conclusions

Despite retrospective nature of the study, the outcomes of surgical construction with process transfer augmented with hook plate fixation are promising for chronic type III and V AC injuries.

Level of evidence

Therapeutic level IV. Retrospective case series, treatment study.