It has been shown in vitro that melanocyte proliferation and function in palmoplantar skin is regulated by mesenchymal factors derived from fibroblasts. In this study, we investigated in vivo the influence of mesenchymal-epithelial interactions in human tissue-engineered skin substitutes reconstructed from palmarand nonpalmoplantar-derived fibroblasts. Tissue-engineered dermo-epidermal analogs based on collagen type I hydrogels were populated with either human palmar or nonpalmoplantar fibroblasts and seeded with human nonpalmoplantar-derived melanocytes and keratinocytes. These skin substitutes were transplanted onto fullthickness skin wounds of immunoincompetent rats. Four weeks after transplantation the development of skin color was measured and grafts were excised and analyzed with regard to epidermal characteristics, in particular melanocyte number and function. Skin substitutes containing palmar-derived fibroblasts in comparison to nonpalmoplantar-derived fibroblasts showed (a) a significantly lighter pigmentation; (b) a reduced amount of epidermal melanin granules; and (c) a distinct melanosome expression. However, the number of melanocytes in the basal layer remained similar in both transplantation groups. These findings demonstrate that human palmar fibroblasts regulate the function of melanocytes in human pigmented dermo-epidermal skin substitutes after transplantation, whereas the number of melanocytes remains constant. This underscores the influence of sitespecific stromal cells and their importance when constructing skin substitutes for clinical application.

As deep soft tissue defects with exposed bone, cartilage or tendons are not suitable for wound closure with skin mesh grafts, other techniques are needed. We report on six patients, one female and five males, aged between 32 and 89 years, and deep soft tissue defects with exposed tendons, cartilage or bone. The aetiology of these defects was vascular (n = 3), tumour surgery (2), and post-traumatic (1). Wounds were treated with a collagen-elastin matrix applied above the exposed structures. In five patients, the procedure was combined with mesh graft transplantation in the same setting. Follow-up varied between 12 and 40 weeks. Wound healing was uncomplicated in all transplanted patients until first dressing change after 7 days. All but one transplant showed a 100% take rate and the transplant was stable within 10-14 days. A complete wound closure was also achieved without transplantation, but this took 8 weeks. No adverse effects were noted. There was no skin contracture of the skin grafts. Collagen-elastin matrix with split-thickness skin grafts is a useful tool in deep soft tissue. The time to heal can be reduced.

Purpose of Review Management and clinical evaluation of children who present with cervical spine injuries can be challenging, particularly in the pre-verbal child and in the presence of polytrauma. Recent Findings The successful approach to the pediatric patients' cervical spine involvement requires the following elements: an understanding of the significance of the problem, basic principles involved the management of pediatric cervical spine, and the role of radiologic studies in this patient population. Summary This chapter highlights the common characteristics and principles behind cervical spine trauma in children, reviews the available evidence for assessment of these injuries, and focuses on a step-wise approach that can be used in the assessment and clearance of the pediatric cervical spine.

Ochrobactrum anthropi is an opportunistic, low-virulence pathogen occasionally associated with human infections and found largely in immunocompromised patients and those with intravascular devices. We report the case of a healthy 70-year-old man who presented with an infection of the hand, who had no history of trauma but had been gardening for 4 months. Despite surgical debridement and empirical antibiotics, the infection could not be controlled. Cultures revealed O anthropi. Antibiotic treatment was adapted to intravenous cefepime for 15 days and the infection was finally controlled after a second surgery. Oral cotrimoxazole was continued for another 2 weeks. Ochrobactrum anthropi infection of the hand must be considered not only in immunosuppressed patients but also in healthy patients without intravascular devices. Local debridement and empiric antibiotic may be insufficient. Antibiotic therapy should follow susceptibility testing, but usually includes a broad-spectrum intravenous beta-lactam such as imipenemecilastatin or cefepime, or oral cotrimoxazole or ciprofloxacin.

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