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PubMed2002

Use of allogenic dermis for radial forearm free flap donor site coverage.

OBJECTIVE: The radial forearm free flap has become the method of choice for reconstruction of head and neck defects following oncologic ablation. Harvesting of a radial forearm free flap leaves a donor site defect. This is most commonly closed with a split-thickness skin graft. Morbidity, most commonly owing to a lack of graft take over the tendons, can be quite high. Recently, an acellular matrix (Alloderm) has been advocated to decrease complications at the radial forearm donor site, as well as obviate taking a split-thickness skin graft from the thigh. MATERIAL AND METHODS: Tertiary referral academic centre. Retrospective chart review of 15 patients. Five patients received allogenic dermis, 10 patients received split-thickness skin grafting to the radial forearm donor site. RESULTS: Patients with allogenic dermis took between 12 and 16 weeks to heal completely. Patients undergoing split-thickness skin graft were completely healed within 4 to 6 weeks. Cosmesis was judged to be marginally better in the allogenic dermis group. Allogenic dermis placement had a greater impact on hand function owing to prolonged healing, whereas patients with split-thickness skin graft required wound care at the thigh for a 2- to 3-week period owing to the harvesting of the skin graft. CONCLUSIONS: Allogenic dermis may be a viable alternative to split-thickness skin grafting and radial forearm free flap donor sites. Prolonged healing with subsequent increased health care services use needs to be addressed.

Aged↗

PubMed1996

Dorsal dermis of the scaleless (sc/sc) embryo directs normal feather pattern formation until day 8 of development.

We have examined the ability of the scaleless (sc/sc) backskin dermis (6 to 16 days of incubation) to regulate pattern formation using the presumptive scutate scale epidermis from 11-day normal embryos as the responding tissue. Prior to 8 days of incubation the sc/sc backskin dermis is able to induce hexagonally patterned and uniformly oriented feather germs in normal epidermis. This ability is lost during day 8 and follows a central to lateral gradient. Such gradients are characteristic of normal feather development in the spinal tract. We discuss the change in the inductive ability of the sc/sc dermis in relation to the stabilization of the feather pattern, which occurs all at once throughout the dorsal dermis at 7.5-8 days of development. After day 8 until day 10, the sc/sc backskin dermis only supports the formation of sporadic, unpatterned feather germs; thereafter it will not support feather formation.

Animals↗

PubMed1981

The ability of localized implants of whole or minced dermis to disrupt pattern formation in the regenerating forelimb of the axolotl.

The ability of localized grafts of dermis to alter pattern formation in the regenerating limb of the axolotl was studied. Longitudinal pieces of skin (1/4 of circumference of the limb) were removed from either the anterior or the posterior surface of the upper forelimb. Epidermis was removed by immersion in versene followed by mechanical stripping. The resulting dermis was cross transplanted directly beneath the skin on the opposite side of the limb from which it originated. After 5 days of healing each limb was amputated through the graft at the midpoint of the humerus. High percentages of multiple regenerates resulted. Similar results were obtained when dermis was minced into 1 mm3 fragments prior to cross-transplantation. Freezing or x-raying (2000 rads) the grafts prior to cross-transplantation abolished the effect. Dermis obtained form head skin rarely caused multiple regeneration when implanted into the upper forelimb followed by amputation 5 days later. These results demonstrate that addition of dermis to an intact limb stump profoundly alters pattern formation during regeneration. The effect is dependent upon viable cells that are capable of cell division.

Ambystoma↗

PubMed1984

The differentiation of the dermis in the laboratory mouse.

The purpose of this study was to provide a comprehensive and sequential account of the differentiation of the dermis in one body region in a mammalian species. A histological, histochemical, and ultrastructural study was made of each cellular and matrix component of the dermis of the upper lip of the mouse during prenatal development. On the basis of these observations, the development of the dermis was divided into four phases: I) undifferentiated mesenchyme (12, 13 days), II) cell differentiation (14, 15 days), III) dynamic transition (16 days), and IV) matrix differentiation (beginning at 17 days). The first phase was marked by a decrease in the cell density but no change in the ultrastructure of the undifferentiated mesenchyme cells. The second phase began with the cytodifferentiation of the mesenchyme cells and was characterized by the appearance of new cell types in the dermis (immature fibroblasts, mast cells, myoblasts, and cells of indeterminate type). During phase III the dermis was undergoing rapid change. Fibroblasts became fully differentiated, mast cell density reached a sharp peak, there was a marked increase in the number of collagen fibrils in the dermal matrix and the first collagen fibers were observed, and changes occurred in the pattern of proteoglycan synthesis. Aggregations of vesicles appeared to be extruded from cytoplasmic blebs on the fibroblasts in large quantities at this time. Further differentiation of the dermal intercellular matrix occurred during the fourth phase, which continued after birth, as more collagen was laid down to form the connective tissue stroma.

Animals↗

PubMed1993

Different rates of ultraviolet-induced DNA damage in the epidermis and dermis of a platyfish model for carcinogenesis.

The purpose of this study was to compare fluence-response relationships for the production of cyclobutane pyrimidine dimers in epidermal or dermal DNA of platyfish Xiphophorus hybrids irradiated with UVB, and to determine photoreactivation from black light on dimers produced in situ. This was accomplished by quantitative gel electrophoresis of unlabeled DNA following extraction of the DNA and treatment with an enzyme specific for the detection of pyrimidine dimers. The dermis was the target tissue for UV-induced DNA damage in Xiphophorus hybrid fish skin. Shapes of dimer-fluence response data following filtered sunlamp irradiation (lambda > 290 nm) or monochromatic wavelength 302 nm in the epidermis or dermis were different. In the epidermis there was an initial step upward slope followed by a plateau, whereas in the dermis a linear relationship was observed. The final values of dimers at the high doses were, however, nearly equal in the epidermis and dermis exposed to either radiation. These differences in fluence-response relationships are probably attributable to the intertwining of the epidermis and to the shielding effect of the epidermal layer, with scales leading to a heterogeneous population of cells which are exposed to different UV doses. Photoreversal of dimers was readily observed by black light irradiation in both epidermis and dermis irradiated with either lambda > 290 nm or 302 nm.

Animals↗

PubMedDate not supplied

Usefulness and limitations of artificial dermis implantation for posttraumatic deformity.

We have previously reported the use of artificial dermis implantation to cover exposed major vessels and to correct a depressed region after tissue resection and bone deformity with satisfactory results. In this paper, we present cases with depressed lesions and adhesive lesions after trauma, treated with artificial dermis implantation. Artificial dermis (Terudermis, Terumo Co. Ltd., Tokyo, Japan) was implanted in 12 cases of posttraumatic deformity. Eight of the 12 cases involved a depressed lesion, and the other four involved adhesive lesions. There was no postoperative infection or allergic reaction in any of the patients. Improvement of the deformity was obtained in all cases, but the degree of volume reduction in traumatic cases is likely to be more severe than that in the non-traumatic cases previously reported. In conclusion, artificial dermis implantation is an easy, safe, and useful method to correct a posttraumatic deformity, such as a depression or an adhesion, although it is important to note that depressions require overcorrection in order to obtain satisfactory results, as compared with non-traumatic cases treated with artificial dermis.

Adult↗

PubMed1996

Evaluation of an artificial dermis full-thickness skin defect model in the rat.

An artificial dermis product was applied to full-thickness skin defects in rats and cell infiltration into the collagen matrix was investigated. Host fibroblasts and capillaries infiltrated as far as the upper end of the collagen matrix by day 14 after application. Determination of glycosaminoglycan levels in the matrix showed that hyaluronic acid was generated in a similar amount to that seen in the intact skin by day 14. An autologous thin split-thickness skin graft was placed onto the artificial dermis simultaneously or several days after its application to the defect. The take rate was 100% when a split-thickness skin graft was performed on day 14 after application of the artificial dermis. At 6 weeks after the skin defect was created, the wound area was 80% of the original area and the dermis at the grafted site was as thick as that of normal skin. These results suggested that the artificial dermis provides a good matrix for thin split-thickness skin graft and is useful for the reconstruction of full-thickness skin defects. This method is considered to be an alternative to the conventional procedure using thick skin grafts or skin flaps.

Animals↗

PubMed1980

The dermis is required for the synthesis of extracellular glycosaminoglycans in cultured pig epidermis.

1. Slices of pig ear skin were cultured in the presence of D-[3H]glucosamine and the epidermis solubilised in 8 M urea/5% sodium dodecyl sulphate was analysed by polyacrylamide gel electrophoresis. A high molecular weight peak, previously shown to contain glycosaminoglycans, was a major labelled component of epidermis separated from dermis using either CaCl2, dispase or trypsin. This material was unlikely to represent dermal contamination of the epidermis since (a) it was present mainly in epidermis rather than dermis, and (b) both histology and comparison of protein compositions showed the epidermis to be essentially free of dermal components. 2. When the epidermis was separated from dermis before rather than after culture (using CaCl2, dispase, trypsin or suction) the labelled glycosaminoglycan peak was never observed. The labelling of other epidermal glycoconjugates was unaffected. Thus the dermis was necessary specifically for the synthesis of epidermal glycosaminoglycans. 3. All-trans-retinoic acid (1 x 10(-5) M) had a marked effect on the labelling of the epidermal but not the dermal glycosaminoglycan peak, indicating that the epidermal glycosaminoglycans were not synthesised in the dermis. 4. The results suggest that dermal influences in the epidermis could be mediated via dermal control of epidermal glycosaminoglycan synthesis.

Animals↗

PubMed2005

Accelerated wound healing through the incorporation of basic fibroblast growth factor-impregnated gelatin microspheres into artificial dermis using a pressure-induced decubitus ulcer model in genetically diabetic mice.

The objective of this study was to evaluate the effect of incorporating basic fibroblast growth factor (bFGF)-impregnated gelatin microspheres into an artificial dermis on impaired wound healing using a pressure-induced decubitus ulcer model in genetically diabetic mice. Daily 10 h prolonged pressure at 500 g/cm2 was loaded for 2 consecutive days over the femoral trochanter tertius of mice to produce ischemic necrosis. Five days after completion of the pressure load, the necrotic tissues were resected. Then, an artificial dermis incorporating bFGF-impregnated gelatin microspheres or bFGF in solution was implanted into the wound (n = 5). Mice were sacrificed at 5, 7, and 10 days after implantation, and a full-thickness biopsy was taken and stained with hematoxylin and eosin for histological analysis. All experimental animals were infected because diabetic mice have little tolerance for infection. Seven days after implantation, the incorporation of bFGF into the artificial dermis reduced infection and accelerated fibroblast proliferation and capillary formation. However, the accelerated effects were more significant with the incorporation of bFGF-impregnated gelatin microspheres than with free bFGF. We conclude that the incorporation of bFGF-impregnated gelatin microspheres into an artificial dermis induced tissue regeneration in an artificial dermis in an impaired wound healing model.

Animals↗

PubMed2003

Culture of rat keratinocytes with acellular pig dermis.

This study evaluated the growth rate and the cell activity of cultured keratinocytes on acellular pig dermis in order to develop a composite skin in vitro for burn injuries or other skin defects. Full thickness skin was cultivated from neonatal SD rats, and separated into epidermal layer and dermal layer with enzyme digestion. The keratinocytes were then seeded on the prepared acellular pig dermis soaked in the culture medium. The cultures were incubated and the growth status of keratinocytes on acellular pig dermis evaluated by phase contrast microscope, histological examination with hematoxylin-eosin staining and acridine orange staining, immunohistochemistry, observation of growth curve plotted by MTT colorimetry and analysis of changes in keratinocytes proliferation cycle with flow cytometer. Almost all keratinocytes anchored in 48-72 h, and most inosculated at days 6 and 7. The growth curve showed that the keratinocytes grew in logarithmic phase at days 3-6 after seeding. More than four layers of keratinocyte structure and the basement membrane between keratinocytes and porcine dermis were observed. Pancytokeratin was strongly positive in the cultured keratinocytes. Laminin and collagen IV were positive in the basement membrane. It is concluded that the cultured keratinocytes on acellular pig dermis grow well and the structure of composite skin which has been established is satisfactory.

Animals↗

PubMed1997

Reconstruction of burn deformity using artificial dermis combined with thin split-skin grafting.

Twelve patients with post-burn contracture were treated using artificial dermis combined with thin split-skin grafting during the period January 1994 to April 1996. Bilayer artificial dermis was grafted onto full thickness open wounds of the skin, after excision of scar contracture tissue. About 3 weeks later, the silicone layer was removed and thin split-skin, 8/1000 in. thick, was grafted onto the newly synthesized dermis-like tissue in the wound bed. Scalp was chosen as the donor site in 11 of the 12 cases. Artificial dermis grafting was undertaken to ensure that morbidity at the donor site could be reduced as much as possible in the treatment of burn deformity. The skin grafts took completely in all cases. Postoperative management was performed in accordance with conventional skin grafting. Postoperative contraction or hypertrophic scar was observed in three cases, but a soft, favorable quality was obtained in the other nine cases. Treatment of burn deformity with artificial dermis may be beneficial in selected cases.

Adolescent↗

PubMed1996

Characterization of collagen fibril segments from chicken embryo cornea, dermis and tendon.

The cornea, dermis and tendon have extracellular matrix architectures with differences in fibril diameter, packing and organization. An early step in fibril assembly is the formation of a striated fibril of discrete length (segment). Fibril segments were isolated from developing chicken cornea, dermis and tendon by physical disruption and the structure characterized. In all three tissues, intact but relatively short fibril lengths were isolated. These segments were asymmetric, having long (alpha) and short (beta) tapered ends. They were also centrosymmetric with respect to molecular packing. Segments isolated from 12- to 16-day corneas, dermis and tendons had identical structures, but their lengths and diameters were distinct. We propose that the increase in length is, at least in part, the result of lateral associations of adjacent segments. In the developing tendon, there is a rapid increase in length and diameter between day 16 and 17, while in the dermis the increase is more linear with respect to time. In the cornea, the fibril segments grow longer, but their diameters remain constant. Disruption of corneas in phosphate-buffered saline yielded larger diameter segments than seen in situ, while tendon or dermis maintained tissue-specific diameters. When corneas were disrupted in buffers that stabilized the water layer associated with the collagen molecules or containing the corneal proteoglycans, then tissue-specific diameters were maintained. These data suggest differences in the stabilization of segments during growth in tissues where diameter increases versus those where diameter remains constant, and this may be related to collagen-proteoglycan interactions.

Animals↗

PubMed1982

The exclusion of human serum albumin by human dermal collagenous fibres and within human dermis.

Preparations of dermal collagenous fibres and slices of human dermis have been equilibrated with 125I-labelled monomeric human serum albumin. The space inaccessible to the albumin in the fibres and in the dermis was determined by subtraction of the accessible space, calculated from the radioactivity of the specimen, from its total fluid. For a fibre preparation examined in detail, the fluid exclusion was independent of the concentration of either albumin or collagen. Binding of albumin to the fibres was not demonstrable. Three fibre preparations excluded albumin from 3.75 +/- 0.96, 3.55 +/- 0.67, and 2.05 +/- 0.39 g of fluid/g of collagen (+/-S.D.). Slices from three specimens of dermis excluded albumin from 1.45 +/- 0.08 g of fluid/g of insoluble solids or 1.57 +/- 0.11 g of fluid/g of collagen (+/-S.D.). Thus the exclusion of albumin by dermis was much less than expected from its content of collagenous fibres. On the basis of these data and the published composition of dermis, the concentration of albumin in the accessible interstitial space was estimated to be close to that in the plasma.

Adult↗

PubMed2003

Dry environment increases mast cell number and histamine content in dermis in hairless mice.

BACKGROUND: A variety of skin diseases, such as atopic dermatitis, senile xerosis or psoriasis tends to worsen during the dry winter season. These skin diseases are also characterized by itch sensation. OBJECTIVES: To evaluate the generation of histamine in the dermis of hairless mice kept under various conditions of environmental humidity. MATERIALS AND METHODS: We carried out the quantification of mast cell population and evaluated the histamine content in the epidermis, dermis and serum of the mice kept under various conditions of environmental humidity. RESULTS: Histamine content in the dermis of the mice kept in a low environmental humidity (relative humidity < 10%) for 3 and 5 days was significantly higher than that of the mice kept in a high environmental humidity (relative humidity > 80%) for the same period of time. No significant difference was observed on the histamine content in the epidermis between the two humidity groups. The number of mast cells in the dermis of the mice kept in the low environmental humidity was significantly higher than that of the mice kept in the high environmental humidity. Topical application of petrolatum reduced the level of histamine in the dermis of the mice under the low environmental humidity. CONCLUSIONS: These results suggest that a low environmental humidity increases mast cell number and dermal histamine content.

Animals↗

PubMed1998

Analysis of matrix protein components of the dermis-like structure formed in a long-term culture of human fibroblasts: type VI collagen is a major component.

Formation of a dermis-like structure by a long-term culture of fibroblasts in the presence of ascorbic acid is a potential model for tissue organization or wound healing, and has its practical use as a skin graft. In the present study, solubilization of the dermis-like structure without pepsin treatment was attempted for analysis of pepsin-labile matrix components that might be involved in the formation of the dermis-like structure, as well as quantification of mutated type I collagen that could be susceptible to pepsin. The whole dermis-like structure was dissolved in a Tris buffer containing SDS and urea at 80 degreesC. Analysis of the extract by SDS-PAGE revealed several protein bands that were not found in the pepsin-treated extract. Among them, the polypeptide band migrating at 140k under reducing condition showed a similar intensity of protein staining to the alpha2(I) chain band. The N-terminal amino acid sequences of cyanogen bromide peptides derived from the 140k polypeptide band as well as the amino acid composition of the band suggested that the band essentially consisted of alpha1(VI) and alpha2(VI) chains. The results demonstrated that the type VI collagen was a major component, being a comparable in amount to type I collagen, in the dermis-like structure.

Adolescent↗

PubMed1997

Use of a porcine dermis template to enhance widely expanded mesh autologous split-thickness skin graft growth: preliminary report.

To answer the question whether a xenograft dermal substitute could enhance skin grafting, we used porcine dermis as a template for a widely expanded mesh autologous split-thickness skin (ASTS) graft in a rat model. Four groups of rats had received widely expanded meshed skin autografts to cover an excised back wound. Group 1 had a bed of autologous dermis, group 2 had porcine xenograft dermis, group 3 had widely expanded meshed autograft alone, and group 4 had no graft with the wound healing by contraction alone. Wounds were studied by clinical inspection for texture and contraction, and by histologic and immunofluorescent techniques. At 2 weeks, there was acceptable ASTS graft take, and most of the wound healed completely by 3 weeks. The integrity of this complex skin graft was maintained for 4 months but wound contraction gradually decreased overall wound size. Size was maintained better in the ASTS-autodermis and ASTS-xenodermis groups at postgraft 4, 5, and 6 weeks when compared with the ASTS graft, and there was no difference between the ASTS-autodermis and ASTS-xenodermis groups. Thus both allodermis and xenodermis provided a similar template to enhance widely expanded mesh skin growth and delay wound contraction. The pathologic studies indicate that the xenodermis collagen was replaced either by fibrosis or by biodegradation to rat collagen. The immunofluorescent study also reflected that anti-porcine antibody activity was hugely diminished in the ASTS-xenodermis graft wound after long-term follow-up. In conclusion, either autodermis or xenodermis enhances widely expanded mesh ASTS survival in a rat model, and could significantly maintain the original wound size better than ASTS graft without a template. In a long-term follow-up study, the porcine dermis was replaced either by fibrosis or biodegradation to rat dermis.

Animals↗

PubMed2001

The use of acellular dermis in the prevention of Frey's syndrome.

EDUCATIONAL OBJECTIVE: At the conclusion of this presentation, the participant should be able to discuss the indications and advantages of using acellular dermis in the prevention of post-parotidectomy gustatory sweating (Frey's Syndrome). INTRODUCTION: Gustatory sweating is a common postoperative problem and a challenge to treat. The purpose of this study was to evaluate the role of acellular dermis in preventing post-parotidectomy gustatory sweating. METHODS: Sixty-four patients were randomly assigned to two groups. Group I consisted of 32 patients who underwent a superficial lobe parotidectomy. Group II consisted of 32 patients who underwent a superficial lobe parotidectomy and underwent intraoperative placement of acellular dermis within the parotid bed, between the skin flap and the remaining parotid tissue. The implanted volume of acellular dermis was determined by the amount required to aesthetically restore lateral facial contour. All 64 patients were evaluated for gustatory sweating by identical phone and mail questionnaires. Thirty randomly chosen patients (group I = 15, group II = 15) were evaluated using a modified Minor's Starch-Iodine Test (MSIT). In all 30 patients, the MSIT was administered to both sides of the face. RESULTS: The responses to questionnaires (N = 64) demonstrated the subjective presence of gustatory sweating in 3 of 32 patients (9.3%) in group I, whereas group II demonstrated a subjective incidence in 1 of 32 patients (3.1%). The objective incidence determined by those who underwent the MSIT (n = 30) revealed a 40% (6) and 0% incidence of Frey's Syndrome in groups I and II, respectively. The complication rate in group I was 9% (3 seromas) and in group II it was 25% (7 seromas and 1 wound infection). CONCLUSIONS: Acellular dermis appears to be an effective method for preventing post-parotidectomy gustatory sweating, despite its higher complication rate.

Biocompatible Materials↗

PubMed2005

Artificial dermis as an alternative for coverage of complex scalp defects following excision of malignant tumors.

BACKGROUND: Artificial dermis has been used successfully for coverage of full-thickness wounds with a well-vascularized surgical bed. However, the use of artificial dermis in the reconstruction of partial- and full-thickness scalp defects has not been well documented. METHODS: Seven patients (six men and one woman; mean age, 70 +/- 14 years) with partial-thickness (three patients) and full-thickness (four patients) soft-tissue defects of the scalp (mean defect area, 97 +/- 58 cm) following resection of recurrent malignant tumors and/or previous failed reconstructions underwent staged scalp reconstruction with a bilaminate skin substitute (Integra). After adequate debridement of scalp wounds, including burring the outer table of the calvaria down to bleeding bone for full-thickness defects, Integra was scored and applied unexpanded. A split-thickness skin graft (0.011 +/- 0.0 inch in thickness) was placed on the operative site at postoperative day 36 +/- 15 after removal of the silicone layer of the artificial dermis. Two patients required repeated applications of artificial dermis to compensate for contour deficits before skin grafting. RESULTS: Clinically, all reconstructed areas showed well-vascularized neodermis before skin grafting. There was a 100 percent take of the skin grafts, with no infections or other complications noted. All reconstructive procedures were performed in less than 3 hours of combined operative time, with the last stage performed on an outpatient basis. CONCLUSIONS: Artificial dermis can be used successfully for reconstruction of complex scalp defects following oncologic resection, offering minimal donor-site morbidity, expedient operative time, and when needed, temporary quality closure until final pathologic results are known. Integra skin may offer another option for definitive management of extensive full-thickness scalp defects.

Aged↗