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PubMedDate not supplied

Healing of chronic foot ulcers in diabetic patients treated with a human fibroblast-derived dermis.

A prospective, multicenter, randomized, controlled 12-week study was undertaken to evaluate the effectiveness of a human fibroblast-derived dermis for treating foot ulcers in the diabetic patient. This report summarizes the findings from one center. Following a 2-week screening period, patients were randomized to either human fibroblast-derived dermis (HFDD) (Dermagraft) plus saline-moistened gauze or to the control group (CT) of saline-moistened gauze alone. Effectiveness end points were: 1) wound closure by week 12, 2) time to wound closure, and 3) percent wound closure by week 12. Safety was assessed by review of adverse events and laboratory findings. Patients randomized to HFDD received an application at day 0 and up to seven additional treatments. All patients in each group received shoes with custom-molded inserts and were seen weekly. The study population was comprised of 28 patients (14 HFDD/14 CT) with chronic ulcers (>6 weeks' duration at time of screening). By week 12, significantly more chronic ulcers healed in the HFDD group than in the CT group (71.4% versus 14.3%, p = .003). Healed HFDD patients achieved wound closure significantly faster than CT patients (p = .004). Patients treated with HFDD showed a statistically significant higher percent of wound closure by week 12 than did CT patients (p = .002). The percent of patients who experienced an infection involving their study wound was less in the HFDD group than in the CT group. It was concluded that HFDD is a safe and effective treatment for chronic foot ulcers in diabetic patients.

Cells, Cultured↗
PubMed2004

Clinical evaluation of a new bilayer artificial dermis for repair of oral mucosal defects: report of two cases.

Free mucosal grafts or split-thickness skin grafts have been used in patients undergoing repair procedures for oral mucosal defects. Conventional methods require the creation of second surgical wounds for use as donor sites. We applied two bilayers of artificial dermis to repair a buccal mucosal defect in one case and vestibular extension in another case. After removal of the sutures, no infection, pain, or hemorrhage developed in these patients. The results of granulation and epithelialization were good. Satisfactory appearance and function were achieved in both cases. Therefore, bilayer artificial dermis may be recommended for the repair of oral mucosal defects.

Aged↗
PubMed2002

Langerhans cells that express matrix metalloproteinase 9 increase in human dermis during sensitization to diphenylcyclopropenone in patients with alopecia areata.

BACKGROUND: We know little of the initial events during the sensitization phase of contact allergy in humans. Alopecia areata (AA), a disease of unknown pathogenesis characterized by patchy hair loss, may be treated by inducing contact allergy to diphenylcyclopropenone (DPC), later followed by its topical application. OBJECTIVES: To learn more about the initial events during sensitization in human skin, we studied the early events during induction of contact allergy to DPC in patients with AA. METHODS: DPC 2% and sodium lauryl sulphate (SLS) 4% were applied on the backs of eight patients with AA. Punch biopsies were taken 6 and 24 h after application. The biopsies were snap-frozen and cryostat sections were evaluated with immunohistochemistry using antibodies against CD1a, HLA-DR, CD3, CD54 and matrix metalloproteinase 9 (MMP-9). RESULTS: After 24 h all subjects exhibited erythema on the DPC-treated areas. Histological evaluation of biopsies from these areas showed hydropic degeneration and a significantly increased number of MMP-9+ cells in the dermis (P < 0.0005). The MMP-9+ cells were identified with double immunofluorescence staining as CD1a + Langerhans cells. The expression of the other markers studied remained unaltered irrespective of treatment, including treatment with SLS. CONCLUSIONS: Our findings show that DPC induces an irritant reaction leading to an increased number of MMP-9+ CD1a+ cells in the dermis during the initial phase of sensitization.

Administration, Topical↗
PubMed2003

Autogenous dermis skin grafts in lower eyelid reconstruction.

PURPOSE: To describe a new procedure using autogenous dermis to correct lower eyelid retraction secondary to posterior lamella shortening. METHODS: A retrospective case series of 10 eyelids in 7 patients. Autogenous dermis grafts were created from postauricular skin by using dermabrasion. The grafts were placed as posterior lamellar spacers to provide elevation and support for the retracted lower eyelids. The postoperative eyelid height, contour, and complications were documented. RESULTS: All patients demonstrated an elevation of the lower eyelid and a decrease in inferior scleral show. Minimal and transient complications were encountered. CONCLUSIONS: The technique described offers a simple alternative to other methods of posterior lamellar lower eyelid reconstruction.

Blepharoplasty↗
PubMed2006

Low fistula rate in palatal clefts closed with the Furlow technique using decellularized dermis.

BACKGROUND: Despite the advances in cleft palate closure over the past 20 years, postoperative fistulas are still a significant problem. Fistula rates average 10 to 23 percent, and it has been suggested that wide clefts have a higher rate of fistula formation. METHODS: In an attempt to improve closure rates, the authors placed decellularized dermal graft within the closure of 31 consecutive palatal cleft closures using the Furlow technique, with one attending surgeon. A retrospective review of this series of patients was analyzed for cleft width, Veau type, and rate of healing. RESULTS: Average cleft width was 12.2 mm (range, 8 to 15 mm). There were one Veau type I, five Veau type II, 20 Veau type III, and six Veau type IV patients. The average age at time of palate repair was 11.75 months (range, 8 to 28 months). One patient (Veau type IV, 15-mm width) developed fistula (3.2 percent fistula rate overall). There was no evidence of rejection, scarring, or impaired palatal motion by examination. CONCLUSIONS: A low fistula rate was obtained in Furlow technique palatal cleft repairs using decellularized dermis when compared with historical controls. Decellularized dermis may provide an additional barrier to wound breakdown in the postoperative period and may improve fistula rate.

Child, Preschool↗
PubMed2000

Appearance of peculiar vessels with immunohistological features of high endothelial venules in the dermis of moxibustion-stimulated rat skin.

Morphological changes of the dermal blood vessels ofmoxibustion-stimulated rat skin were examined with reference to the lymphocyte migration. After long-term stimulation with direct moxibustion to the acupoint tsu-san-li (St-36), peculiar vessels that possess immunohistological features of high endothelial venules could be observed in the moxa-stimulated acupoint dermis. Endothelial cells of the vessels had well-developed Golgi apparatus in their plump cytoplasms, and they strongly expressed intercellular adhesion molecule-1 on the luminal surface. These data suggest that the appearance of the peculiar vessels in the dermis acts toward the active infiltration of blood-lymphocytes into the acupoint skin.

Animals↗
PubMed1999

CD44 expression marks the onset of keratinocyte stratification and mesenchymal maturation into fibrous dermis in fetal human skin.

The cell surface glycoprotein CD44 is involved in active cell movement, cancer metastasis, and morphogenesis. We studied its expression in fetal human skin using an antibody specific for CD44v3 and another that recognizes all CD44 forms. In embryonic and early fetal skin, only cells with dendritic morphology expressed CD44. The first keratinocyte expression of CD44 occurred in the basal cells on the eleventh week. Later, the suprabasal cells also turned positive, whereas periderm and the terminally differentiated cells remained negative at all stages. Maturation of the early mesenchyme towards dermis at the eleventh week was associated with an increase in the number of CD44-positive cells, and later the fibrous extracellular matrix also became CD44-positive. During hair induction, the epithelium showed a transient downregulation of CD44. Later, the follicular cells regained CD44. Cells in the primordial dermal papilla displayed a continuously strong signal. The sweat gland anlagen showed faint CD44 positivity. Exon 3 was present in the CD44 of keratinocytes and their derivatives but was absent in dermis. CD44 expression in human fetal skin is a relatively late event, associated with maturation and adult-type differentiation both in epidermal keratinocytes and in dermal fibroblastic cells.(J Histochem Cytochem 47:1617-1624, 1999)

Dermis↗
PubMedDate not supplied

A factor implicated in the myogenic conversion of nonmuscle cells derived from the mouse dermis.

Using the mdx mouse model for human Duchenne muscular dystrophy we have shown that a cell population residing in the dermis of C57B1/10ScSn mouse skin is capable of converting to a myogenic lineage when implanted into the mdx muscle environment. It was important to determine the characteristics of the converting cell. A previous in vitro study indicated that 10% of cells underwent conversion but only when the cells were grown in medium previously harvested from a myogenic culture. In the present study we cloned cells derived from the dermis to identify the converting cells. Clones grown in normal growth medium showed no conversion, but when grown in medium conditioned by muscle cells around 40% conversion was achieved in several individual clones. We investigated whether the protein beta-galactoside binding protein (betaGBP), which is secreted by myoblasts and acts as a cell growth regulator of fibroblasts. could be a candidate factor responsible for conversion. Medium harvested from COS-1 cells infected with a construct containing betaGBP has been used for this investigation. Growth of dermal fibroblasts in medium enriched with this factor showed a high rate of conversion to cells expressing muscle-specific factors.

Animals↗
PubMed1999

Absence of integrin alpha1beta1 in the mouse causes loss of feedback regulation of collagen synthesis in normal and wounded dermis.

Integrin alpha1beta1 is a collagen receptor predominantly found in mesenchymal tissues. Mice lacking this receptor are viable. We have previously suggested that alpha1beta1 might participate in the down-regulation of collagen gene expression observed in cells suspended inside collagen gels. The results presented here demonstrate that integrin alpha1beta1 acts as a feedback regulator of collagen synthesis both in vitro and in vivo. Firstly, alpha1 null animals show a higher rate of collagen synthesis in the dermis in vivo. Secondly, fibroblasts derived from alpha1 null cutaneous wounds show a reduced sensitivity to collagen gel induced downregulation of collagen mRNA synthesis, as compared to their wild-type counterparts. An increase in collagenase synthesis is also seen in the alpha1 null dermis and in collagen gel suspended fibroblasts. While dermal thickness is normal in the alpha1 null animals, an increase is seen in skin thickness of alpha1 null but not alpha1 heterozygote animals on a background of collagenase resistant collagen. Increased expression of both collagen and collagenase mRNA are seen in experimental granulation tissue in alpha1 null animals, but their ultimate accumulation of collagen is normal, probably due to non alpha1 dependent paracrine regulators of collagen turnover.

Animals↗
PubMed2004

Skin development in bony fish with particular emphasis on collagen deposition in the dermis of the zebrafish (Danio rerio).

The first part of this article is a review of the current status of knowledge of the fish skin, with particular attention to its development. In the second part we present original results obtained in zebrafish (Danio rerio), with particular emphasis on the deposition and organisation of the dermal collagenous stroma. Using a series of zebrafish specimens aged between 15 hours postfertilization (hpf) and 4.5 years old, we have combined Transmission Electron Microscopy (TEM) observations and in situ hybridisation using type I collagen a2 chain (Col1a2) probe. Collagen fibrils, with a diameter of 22 nm, appear first in an acellular subepidermal space at 24 hpf, are first all oriented in the same direction, and form the primary dermal stroma. Subsequently, three events occur. (1) From 5-7 days pf (dpf) onwards the collagen fibrils self-organise into several lamellae arranged in a plywood-like structure, starting in the upper layers and progressing throughout the entire thickness of the dermis. (2) At 20-26 dpf, fibroblasts of unknown origin progressively invade the acellular collagenous stroma, some of them accumulating below the epidermis. (3) Concomitant with the invasion of fibroblasts, the collagen fibrils increase progressively in diameter to reach 160 nm towards the end of the fish life. In situ hybridisation experiments reveal that, between 24 and 48 hpf, the collagen matrix is produced by the epidermis only. From 72 hpf to 20-26 dpf, both the basal epidermal cells and the dermal cells bordering the deep region of the dermis are involved in the production of collagen. When the fibroblasts invade the plywood-like structure, the epidermal cells progressively cease to synthesise collagen, which from this point is produced only by the fibroblasts. This suggests that the fibroblasts secrete a still unidentified signalling molecule that downregulates collagen production by the epidermis.

Animals↗
PubMed2006

Effects of ingestion of collagen peptide on collagen fibrils and glycosaminoglycans in the dermis.

In order to investigate the effects of collagen peptide ingestion on fibroblasts and the extracellular matrix in the dermis, collagen peptide was administered orally to pigs at 0.2 g/kg body weight/d for 62 d, and its effects were compared with those of lactalbumin and water controls. Fibroblast density, and diameter and density of collagen fibrils were significantly larger in the collagen peptide group than in the lactalbumin and water control groups. The two major components of dermal glycosaminoglycans, hyaluronic acid and dermatan sulfate, which are present in the inter-fibrillar space, did not differ significantly among the three groups. However, the ratio of dermatan sulfate, which is derived from fibril-bound decorin, was largest in the collagen peptide group. These results suggest that ingestion of collagen peptide induces increased fibroblast density and enhances formation of collagen fibrils in the dermis in a protein-specific manner.

Administration, Oral↗
PubMed2004

Differentiation of dermis-derived multipotent cells into insulin-producing pancreatic cells in vitro.

AIM: To observe the plasticity of whether dermis-derived multipotent cells to differentiate into insulin-producing pancreatic cells in vitro. METHODS: A clonal population of dermis-derived multipotent stem cells (DMCs) from newborn rat with the capacity to produce osteocytes, chondrocytes, adipocytes and neurons was used. The gene expression of cultured DMCs was assessed by DNA microarray using rat RGU34A gene expression probe arrays. DMCs were further cultured in the presence of insulin complex components (Insulin-transferrin-selenium, ITS) to observe whether DMCs could be induced into insulin-producing pancreatic cells in vitro. RESULTS: DNA microarray analysis showed that cultured DMCs simultaneously expressed several genes associated with pancreatic cell, neural cell, epithelial cell and hepatocyte, widening its transcriptomic repertoire. When cultured in the specific induction medium containing ITS for pancreatic cells, DMCs differentiated into epithelioid cells that were positive for insulin detected by immunohistochemistry. CONCLUSION: Our data indicate that dermal multipotent cells may serve as a source of stem/progenitor cells for insulin-producing pancreatic cells.

Animals↗
PubMed2006

Cutting edge: CD1a+ antigen-presenting cells in human dermis respond rapidly to CCR7 ligands.

Recent data from murine models have confirmed that Langerhans cells are not the only population of APCs in the skin involved in initiating immune responses. In healthy human skin, we identify CD1a(+) dermal APCs located close to the lymphatic vessels in the upper layers of the dermis that are unequivocally distinct from migrating Langerhans cells but exhibit both potent allostimulatory capacity and a chemotactic response to CCR7 ligands. In contrast, CD14(+) dermal APCs are distributed throughout the dermis and lack a chemotactic response to CCR7 ligands. CD1a(+) dermal APCs therefore represent an APC population distinct from Langerhans cells that are capable of migrating to lymph nodes and stimulating naive T cells. In humans, CD1a(+) dermal APCs may fulfill some of the roles previously ascribed to Langerhans cells.

Antigen Presentation↗
PubMed2001

[An experimental study on the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis].

OBJECTIVE: To observe the effects of the recombinant composite skin graft consisting of human epithelium and acellular xeno-dermis on full thickness skin loss wounds, so as to find a new wound covering material. METHODS: Forty-two nude mice with full thickness skin loss on the back were grafted with the composite skin (compound skin grafting group, G) and human keratinocyte sheet (control group, C), respectively. The wound healing conditions, such as wound healing rate and wound contraction rate, were observed at different time points after the operation. Simultaneously, wound tissue samples were harvested for histological examination. RESULTS: The wound healing rate in G group was much higher than that in C group. In contrast, the wound contraction rate in G group was obviously lower than that in C group (P < 0.05). It was indicated by histological examination that there was full differentiation of epithelium, orderly collagen proliferation and obvious reconstruction of the epithelial-dermal conjunction structure in G group. There was no obvious sign of acute immune rejection. CONCLUSION: The wound covering with recombinant composite skin graft of human epithelium and acellular xeno-dermis could improve wound healing quality. The composite skin could be a new skin substitute.

Animals↗
PubMed2002

Technical prerequisites for in vivo microdialysis determination of interleukin-6 in human dermis.

BACKGROUND: Cutaneous microdialysis in vivo in human skin is demonstrably of use in the study of skin metabolism, percutaneous absorption and skin inflammation. A promising area for cutaneous microdialysis is the measurement of cytokines. This requires catheters equipped with membranes permeable to molecules of high molecular weight. OBJECTIVES: To address technical problems of poor sample volume retrieval and analysis sensitivity in the simplest model of provocation, namely the insertion of the catheter itself in vivo into human dermis. METHODS: Use of a polyethylenesulphone membrane, with a cut-off value of 100,000 Da, allowed measurement of target molecules of large molecular weight. Using an adaptation of a commercially available high sensitivity enzyme-linked immunosorbent assay, the ubiquitous proinflammatory cytokine interleukin (IL)-6 was measured in the normal skin of six healthy volunteers after insertion of the microdialysis catheter. RESULTS: Reliable sample volumes and high analyte recovery were achieved either by push-pull pumping or by standard pumping using a perfusate consisting of Ringers Dextran 60 Braun. No IL-6 was detected in 25 of 26 samples taken during the first 100 min after catheter insertion. The IL-6 concentration then increased and remained elevated for the duration of the experiments. CONCLUSIONS: Technical and analytical modifications in the microdialysis technique have allowed the measurement of IL-6 in vivo in human dermis. It is suggested that the cytokine production is the result of the dermal trauma caused by catheter insertion, but the cellular source of the IL-6 is at present unknown.

Adult↗
PubMed2004

[Factors controlling the microstructure of collagen-based dermis regeneration scaffold].

The factors controlling the microstructure and properties of collagen-based bioactive artificial dermis are reviewed. The second component, the pore diameter and porosity, the thickness of scaffold, the bioactive factors as well as the cross-linking density that are important parameters of artificial dermis should be carefully researched and designed. Experiment methods controlling these parameters are suggested.

Biocompatible Materials↗
PubMed2006

[Combined superficial temporal fascial flap with free dermis-fat graft to reconstruct hemifacial atrophy].

OBJECTIVE: To introduce a method to reconstruct hemifacial atrophy (Romberg's disease). METHODS: Through a temporal incision, the compound grafts of pedicled superficial temporal fascial flap and free dermis-fat were inserted into the cheek to correct soft tissue depression on the face. The dermis-fat was harvested from gluteal crease site. RESULTS: 6 cases were treated with this technique. 3 to 10 months' follow-up showed satisfactory results and few resorption of the compound grafts. CONCLUSIONS: The mentioned technique is simple and reliable in reconstructing bulk defects of the face.

Adipose Tissue↗
PubMed1983

Autogenous dermis-fat orbital implantation.

We examined 52 consecutive patients who underwent autogenous dermis-fat implantation in anophthalmic sockets during the past five years. The results of the study show that 81% of the cases had no change in the volume of the graft during a mean follow-up period of 2 1/2 years, ranging from a minimum of six months to a maximum of five years. The remaining 19% underwent graft resorption to a varying degree. We consider dermis-fat graft a procedure of choice in cases of extruded or migrated implants, an alternative to a synthetic allograft in primary enucleations, and a useful procedure in selected cases of enophthalmic and contracted socket.

Adipose Tissue↗