The temporo-spatial expression of fibrillin and elastin in skin regenerating from autologous keratinocyte grafts was studied in three burned children. Skin biopsies taken between 5 days and 17 months after grafting were investigated by conventional immunofluorescence, confocal laser scanning, and electron microscopy. Fibrillin, the major component of 10-12nm microfibrils, appeared 5 days after grafting in a band-like fashion similar to collagen VII at the prospective basement membrane, and the formed the characteristic microfibrillar candelabra at the dermo-epidermal junction by fusion of several fine microfibrils to communicating microfibrils projecting downward into the reticular layer of the neodermis. Four to five months after grafting, several communicating microfibrils were connected to a web of horizontally undulating microfibrils of the neodermis which had developed independently. Elastin was first identified in the deeper neodermis 1 month after grafting as granular aggregates and 4 months after grafting on fibrillar structures and surrounding capillaries of the upper neodermis. Association of elastin with microfibrils in the papillary dermis was not detectable before month 17. Our findings suggest that the cutaneous microfibrillar apparatus develops simultaneously at both the dermo-epidermal junction and the reticular dermis and is a prerequisite for elastic fiber formation. In addition, it might be a driving force for the formation of the papilla-rete ridge pattern.
Since transglutaminases create covalent ␥ -glutamyl-⑀ -lysine cross-links between extracellular matrix proteins they are prime candidates for stabilizing tissue during wound healing. Therefore, we studied the temporo-spatial expression of transglutaminase activity in skin regenerating from cultured epithelial autografts in severely burned children by the specific incorporation of monodansylcadaverine into cryostat sections from skin biopsies obtained between 5 d to 17 mo after grafting. The dansyl label was subsequently immunolocalized in the epidermis, dermal connective tissue, and along the basement membrane. Incubation of cryosections of normal and regenerating skin with purified tissue transglutaminase confirmed the dermo-epidermal junction and the papillary dermis as targets for this enzyme and revealed that in regenerating skin transamidation of the basement membrane zone was completed only 4-5 mo after grafting. Immunoelectron microscopy revealed that three distinct regions on the central portion of anchoring fibrils were positive for monodansylcadaverine in normal skin which were negative during the initial phase of de novo formation of anchoring fibrils in regenerating skin. Biochemically, we identified collagen VII as potential substrate for tissue transglutaminase. Thus, tissue transglutaminase appears to play an important role not only in cross-linking of the papillary dermis but also of the dermo-epidermal junction in particular. ( J. Clin. Invest. 1996. 98:1174-1184.)
From 1984 to 1990 we treated 18 patients aged 5 to 15 1/2 years with solitary bone cysts of the humerus, the femur and the calcaneus. To fill the defect, tricalcium phosphate (TCP) instead of bone grafting was used. The clinical and radiological long-term results up to seven years postoperatively are reported. In 16 patients TCP was well incorporated without any adverse reaction to the synthetic material. Two patients with a recurrence of the bone cyst were successfully reoperated. We conclude that ceramics are a cheap and easy available substitute for bone grafts in the treatment of solitary bone cysts.
We retrospectively reviewed six pediatric cases of medial clavicular injury, i.e., epiphyseal separation (Salter/Harris type I or II injury), diagnosed between 1993 and 1997. The clavicular metaphysis was displaced posteriorly in three cases and anteriorly in three. On conventional radiographic views the diagnosis was initially missed in two of three retrosternal dislocations. A special X-ray projection (described by Heinig) or computed tomography (CT) permitted correct diagnosis. Anterior dislocations were immediately and correctly diagnosed. Closed reduction successfully treated retrosternal displacement in two of the three patients. The third patient needed open reduction and internal fixation. Open reduction and internal fixation had to be performed in all three patients with anterior displacement. Follow-up assessment showed perfect functional results in all cases. Direct visualization during open reduction, which was necessary in four of six cases, yielded clear evidence that the so-called sternoclavicular dislocation in children and young adults is, in fact, a fracture of the medial growth plate with posterior or anterior displacement of the metaphysis.
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