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PubMed1986

Expression of high molecular weight (67K) keratin in human keratinocytes cultured on dead de-epidermized dermis.

The influence of living dermal tissue upon epidermal differentiation during embryonic development as well as in vitro culture has been documented. Living dermal tissue contains both cellular and matricial elements. In the present study, third-passage subcultured adult human keratinocytes were either seeded on plastic dishes or recombined with dead de-epidermized dermis and further cultured for 3 weeks. After this time, keratins were extracted and analysed by one- and two-dimensional gel electrophoresis. The 67K keratin subunit, which is thought to be involved in the process of in vivo type skin differentiation, was absent in ordinary cultures; however, it was expressed in air-exposed cultures on dead de-epidermized dermis. Quantitatively, however, it did not reach the in vivo level. This suggests that in principle, the induction of the expression of this protein does not require the presence of living dermal cells.

Adult↗
PubMed1986

Differential growth of sensory neurons in vitro in presence of dermis and epidermis. A quantitative time-lapse analysis.

The influence of dermal and epidermal cells on the growth of nerve fibres from chick embryo sensory neurons was investigated in vitro. A previous quantitative analysis showed that the growth of nerve fibres is profoundly modified in the close vicinity of epidermis. This change is mainly characterized by erratic trajectories of nerve fibres resulting from numerous lateral displacements of the growth cones. In contrast, no such behaviour is observed far away from the epidermis or in the presence of dermis. In this latter case, neurites exhibit a straighter direction of extension. These observations suggest that the epidermis exerts some kind of control on the establishment of nerve fibre pattern in the dermis.

Animals↗
PubMed1985

Comparative observation of fibroblasts derived from the papillary and reticular dermis of infants and adults: growth kinetics, packing density at confluence and surface morphology.

We have confirmed the reports of Harper and Grove (Science, 204 (1979) 526-527), and Azzarone and Macierira-Coehlo (J. Cell Sci., 57 (1982) 177-187) that fibroblasts derived from the papillary dermis have greater in vitro growth potential and longer replicative lifespans than genomically identical fibroblasts derived from the reticular dermis. In addition we demonstrate that the kinetics of cell replication differ for papillary and reticular fibroblasts derived from infant and adult donors. Infant papillary fibroblasts replicate at faster rates than reticular fibroblasts throughout the growth cycle. Adult papillary and reticular fibroblasts replicate at similar rates at low cell densities, but exponential growth of reticular fibroblasts slows at lower cell densities than papillary fibroblasts suggesting that they are more sensitive to density-dependent inhibition of replication. The surface morphologies of reticular fibroblasts and papillary fibroblasts at confluence correlate with their growth kinetics. The decreased cell yields of reticular fibroblasts appears related to the spreading behaviors of individual cells which stretch and occupy more area of the growth surface than do papillary fibroblasts. These data and the reports cited clearly show that one must account for the presence of at least two distinct populations of dermal fibroblasts when examining their biological properties in vitro.

Adult↗
PubMed1993

Lymphocytic meningitis following insertion of a porcine dermis dural graft.

We describe a case of lymphocytic meningitis following insertion of a porcine dermis implant to repair an operative dural defect. Histology of the excised implant revealed local abscess formation with a granulomatous reaction. Oligoclonal Immunoglobulin G, part of which could be removed by absorbtion with the porcine dermis, was present in the patient's cerebrospinal fluid, and, to a less marked degree, in his serum. The cerebrospinal fluid glucose was markedly depressed. An unusual hypersensitivity reaction to the porcine implant was considered the most likely explanation for this meningitic illness. The patient went on to make a full recovery following excision of the implant.

Adult↗
PubMed1989

Effect of decidua angiogenic factors on experimental dermis allografts.

Meshed human dermis allografts containing human uterine angiogenic factor were implanted over full thickness surgical skin wounds in rats. Enhanced angiogenesis of the wound bed, three times more than that observed in control grafts, was found in experimental grafts at 3 days postimplantation. This was accompanied by a greater amount of granulation tissue formation, enhanced granulation tissue penetration into the dermal grafts and accelerated incorporation of the grafts. Angiogenesis of the wound bed regressed to control levels at 7 days postimplantation. The growth and penetration of the granulation tissue and the accelerated incorporation of the dermis grafts, however, continued ahead in the experimental grafts while necrosis appeared in the control grafts. The relevance of these results for acceleration of wound healing and improvement of the wound bed for subsequent application of cultured epidermal grafts is discussed. This method may be extended to the treatment of ulcers and burns.

Angiogenesis Inducing Agents↗
PubMed1991

Loss of factor XIIIa in pig dermis during tissue expansion.

Considerable evidence suggests that factor XIIIa, a blood coagulation factor, also functions in tissue repair, and specifically in the dynamic process of fibroplasia. On the other hand, the dynamic process of tissue expansion would require a loosening of the dermis, the opposite of fibroplasia. We examined the effects of tissue expansion on the expression of factor XIIIa in pig skin. Standard immunohistochemical procedures were used coupled with a rabbit antibody to factor XIIIa. In this report, we demonstrate that the normal expression of factor XIIIa in pig dermis is completely inhibited at the apex overlying the tissue expander. Factor XIIIa inhibition during expansion supports the thesis that this substance is important in the production and maintenance of fibroplasia.

Animals↗
PubMed1989

SC-41930 inhibits neutrophil infiltration of the cavine dermis induced by 12(R)-hydroxyeicosatetraenoic acid.

Psoriasis is a disease state characterized by epidermal proliferation, neutrophil infiltration, along with release of the proinflammatory mediators leukotriene-B4 (LTB4) and 12(R)-hydroxyeicosatetraenoic acid [12(R)-HETE]. LTB4 and 12(R)-HETE are chemoattractant to the neutrophil, the latter approximately 1000X less potent. LTB4 and 12(R)-HETE are present in psoriatic scale, the latter in quantities so much greater than LTB4 that it is proposed as a primary mediator of neutrophil infiltration in psoriasis. 12(R)-HETE, synthesized in optically pure form by a new, shorter route, was injected into the cavine dermis. At a dose of 25 micrograms m per intradermal site, 12(R)-HETE was a significant chemoattractant to the neutrophil (as assessed by dermal myeloperoxidase levels). SC-41930, 7-[3-(4-acetyl-3-methoxy-2-propylphenoxy)-propoxy]- 3,4-dihydro-8-propyl-2H-1-benzopyran-2-carboxylic acid, given intragastrically inhibited 12(R)-HETE-induced neutrophil infiltration of the cavine dermis with an ED50 value of 13.5 mg/kg. Compounds such as SC-41930 may well have utility for treating human psoriasis.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1991

The antiinflammatory agent SC-41930 inhibits granulocyte infiltration of the rodent dermis induced by 6-trans-leukotriene B4.

Granulocyte diapedesis in response to the generation of defined chemotaxins such as leukotriene B4 (LTB4), 12(R)-hydroxyeicosatetraenoic acid [12(R)-HETE], C5a, platelet activating factor and others is a hallmark of the inflammatory process that is thought to contribute to the tissue pathology seen in a number of diseases. 6-trans-LTB4 arises through the myeloperoxidase (MPO)-dependent metabolism of sulfidopeptide leukotrienes and through the action of 5-lipoxygenase on 12(R)-HETE. The intradermal (i.d.) injection of 6-trans-LTB4 induces a dose and time dependent influx of granulocytes into the guinea-pig (Hartley) dermis. When various doses of the LTB4 receptor antagonist and antiinflammatory agent, SC-41930 (7-[3-(4-acetyl-3-methoxy-2-propylphenoxy)-propoxy]-3,4-dihydro- 8-propyl-2H-1-benzopyran-2-carboxylic acid) given 30 min ahead of i.d. injection of 6-trans-LTB4 (10 micrograms/i.d. site), granulocyte infiltration, as assessed by dermal levels of the neutrophil marker enzyme MPO was inhibited with an ED50 value of 9.8 mg/kg in the guinea-pig. When various doses (10-25 micrograms) 6-trans-LTB4 were injected in the mouse (CD-1) dermis, there was a dose-related increase in granulocyte accumulation at 4 h. Furthermore when mice were pretreated (-30 min) with SC-41930 (1 mg/kg) orally, the trafficking of granulocytes was inhibited (p less than .01) as assessed by dermal MPO levels. SC-41930 orally inhibits 6-trans-LTB4-induced granulocyte accumulation in the guinea-pig more potently than against the response to 12(R)-HETE(ED50:13.4 mg/kg) but less potently than against LTB4 (ED50:0.6 mg/kg). These multiple activities may contribute to this compound's potential as an inflammatory agent.

Animals↗
PubMed1991

Collagen fibril assembly and deposition in the developing dermis: segmental deposition in extracellular compartments.

The hierarchy of extracytoplasmic compartmentalization and fibrillar organization as well as the assembly and deposition of collagen fibrils was characterized in the 15-day chick embryo dermis using transmission electron microscopy. At least two levels of extracellular compartmentalization are recognizable at this stage of dermal development. The first compartment consists of a series of narrow channels containing single or small groups (less than 5) of collagen fibrils. These channels course deep within the cell and are open to the extracellular space. The second extracellular compartment consists of fibrils grouped as small bundles in close association with the cell surface and is most often defined by a single fibroblast. A third level of fibril organization and compartmentalization is sometimes apparent at this stage of dermal development consisting of laterally associated bundles, more characteristic of the mature dermis. This compartment is associated with the fibroblast surface, but is less well defined than the fibril channels or bundle-forming compartments. Dermal collagen fibrils within bundles are discontinuous. Numerous fibrils ends are identified from serial sections and the ends gradually taper. These data indicate that the dermal fibroblast compartmentalizes the extracellular space and deposits collagen fibril segments during dermal morphogenesis. A model for the genesis of the extracellular compartments and their role in collagen fibrillogenesis and development of regularly arranged connective tissues, tendon, and cornea has been proposed. Dermal development conforms to this model and we suggest that extracytoplasmic compartmentalization of the steps in matrix assembly and segmental deposition of collagen fibrils are important mechanisms in the development of a wide variety of connective tissues.

Animals↗
PubMed2006

The long-term results of pubovaginal sling surgery using acellular cross-linked porcine dermis in the treatment of urodynamic stress incontinence.

PURPOSE: Acellular cross-linked porcine dermis is a potential substitute for rectus fascia as a sling material with the advantage of decreased morbidity. However, the long-term efficacy is unknown. We compared the 3-year efficacy of PD vs autologous rectus fascia as a sling material for pubovaginal sling surgery in the treatment of urodynamic stress incontinence. MATERIALS AND METHODS: Between July 2000 and December 2001 a total of 101 consecutive, nonrandomized patients with USI underwent a PD (51) or RF (50) sling procedure. Patients were assessed at 6 weeks, and at 3, 6 and 12 months postoperatively. Urodynamic study was repeated in cases of treatment failure. A detailed survey questionnaire was mailed to all patients at least 36 months after surgery and all responders were then retested by telephone interview by a blinded assessor. The primary outcome measure was patient perceived success rate (cured or improved) at least 36 months after PVS. Secondary outcome measures were patient satisfaction 36 months after surgery, durability of success with time and reoperation rate. RESULTS: Complete data were available on 94 patients (48 treated with PD and 46 treated with RF sling). The groups were well matched for age, leak point pressure, prior incontinence surgery and urge symptoms. Pubovaginal sling was successful (cured or improved) in 37 (80.4%) patients treated with RF but in only 26 (54%) patients treated with PD 36 months after surgery (Fisher's exact test p = 0.009; 95% CI 8.03, 44.4). Treatment failure occurred by 9 months after RF and by 24 months after PD sling procedure. Repeat urodynamic study showed USI to be the cause of treatment failure in 18 (37.5%) of 20 patients treated with PD but in only 3 (6.5%) of 8 patients treated with RF. CONCLUSIONS: We have shown that use of the PD sling, although reducing early morbidity, results in a significantly inferior long-term cure rate in comparison to the RF sling. Therefore, acellular cross-linked porcine dermis should not be used as a substitute for rectus fascia.

Adult↗
PubMed1985

Temporalis muscle transfer: a vascular bed for autogenous dermis-fat orbital implantation.

Nine patients with contracted avascular sockets who were unable to wear prostheses, and whose prospects for maintaining viable autogenous dermis-fat grafts were diminished, underwent temporalis muscle transfer into the orbit through a window in the lateral orbital wall. The temporalis transposition was used as a vascular bed for dermis-fat orbital implantation. Postoperatively, seven of nine patients were able to wear satisfactory prostheses and four of nine patients had amelioration of their superior sulcus deformities.

Adipose Tissue↗
PubMed1989

Dermis-fat grafts and evisceration.

Dermis-fat grafts (DFGs) are currently accepted as a viable reconstructive tool in select cases for primary enucleation, replacing an extruded or migrated implant after enucleation, augmenting superior sulcus defects, and reconstructing socket contracture and enophthalmos. The authors describe a new application using dermis-fat grafting either primarily or secondarily in conjunction with evisceration of selected phthisical globes. Enucleation is no longer the only option available when phthisis is present. Evisceration provides improved cosmesis and motility over enucleation. Implementing a DFG with the authors' method allows improvement in the enophthalmos concomitant with a phthisical globe.

Adipose Tissue↗
PubMed1994

The fat pad in dermis fat grafts.

BACKGROUND: Dermis fat grafts are used in orbital reconstruction in a variety of procedures. However, there have been few controlled studies testing their effectiveness. This is a prospective study on 40 patients. METHODS: Primary and secondary orbital dermis fat grafts were evaluated with regard to the long-term cosmetic results of two thicknesses, 10 and 20 mm, of fat pad, keeping all other parameters as constant as possible. Adequacy of the socket, lid anomalies; superior sulcus deformity, exophthalmometry, and motility of the prosthesis were assessed periodically. CONCLUSION: There was a significantly lower incidence of enophthalmos and superior sulcus deformity with the use of a fat pad thickness of 20 mm, without any compromise in the motility of the prosthesis or take of the graft.

Adipose Tissue↗
PubMed1986

Effects of all-trans-retinoic acid on the dermis of hairless mice.

The marked degradative changes induced in human and animal dermis by chronic ultraviolet radiation are thought to be irreversible. We have shown in studies with hairless mice that a new normal dermis formed subepidermally after irradiation ceased. Because retinoids stimulate wound repair, we evaluated the ability of all-trans-retinoic acid (RA) to enhance the repair of ultraviolet damage. To produce mild dermal damage, hairless mice were irradiated for 10 weeks with FS20 sunlamps. The mice were then treated topically with various concentrations of RA for either 5 or 10 weeks. The skin was examined by light and electron microscopic techniques. The subepidermal repair zone in RA-treated mice was significantly wider than that in the untreated control group. The greater repair appeared to be retinoid specific and was dose dependent. The collagen was both histochemically and ultrastructurally normal; fibroblasts were numerous and morphologically hyperactive. In addition, topical RA increased dermal vascularity.

Animals↗
PubMed1997

Major suppression of pro-alpha1(I) type I collagen gene expression in the dermis after keloid excision and immediate intrawound injection of triamcinolone acetonide.

BACKGROUND: A keloid is a benign tumor that contains excess collagen, primarily type I collagen. A common therapy is intralesional injection of a glucocorticosteroid, such as triamcinolone acetonide (TA). Surgical excision is also common; often a glucocorticosteroid is injected weeks after excision when wound repair has already begun. OBJECTIVE: Our purpose was to determine the efficacy of TA in reducing the pro-alpha1(I) type I collagen mRNA in the dermis, when TA is injected into the wound bed immediately after surgical excision of the keloid. METHODS: Six patients with previously untreated keloids were studied. Three were treated with 10 mg/ml of TA immediately after excision of the keloid (experimental group); the other three patients were not treated with TA until 2 weeks after excision (control). Punch biopsy specimens were obtained from the TA-treated sites 2 weeks after removal of the keloid and from the wounds of the control group of patients before they were treated with TA. Sections were prepared for in situ hybridization analysis of the pro-alpha1(I) collagen mRNA, as well as for histochemical analysis of collagen fibers. RESULTS: All keloids showed greatly elevated levels of pro-alpha1(I) type I collagen mRNA in the dermis. Postsurgical wounds injected with TA after removal of the keloid expressed decreased pro-alpha1(I) collagen transcripts, compared with skin not treated with TA. The collagen bundles were also thinner and less dense in the TA-treated skin. CONCLUSION: Downregulation of the type I collagen gene expression is elicited by immediate TA injection after keloid excision. This suggests that prevention of recurrent keloid growth is possible if surgical excision is accompanied by immediate TA injection into the wound bed and that healing of the wound is not apparently compromised by inhibition of type I collagen gene expression.

Administration, Topical↗
PubMed1984

Dermis ageing.

On ageing major changes within connective components of the dermis can be seen: collagen looses its regular and fascicular appearance, while ground substance increases, elastic material decreases and the fibroblast cell population becomes "at rest". The resulting dermal ageing is different according to individuals and is related to genetic back ground and exposition to multiple aggressions. This review presents these changes of the superficial dermis and the role of fibroblasts in the conservation of the connective tissue integrity.

Adult↗
PubMed2003

A tissue-engineered endothelialized dermis to study the modulation of angiogenic and angiostatic molecules on capillary-like tube formation in vitro.

BACKGROUND: Because angiogenesis is a major feature of different physiological and pathological situations, the identification of factors that stimulate or inhibit this process and the elucidation of their mechanisms of action are most certainly of clinical relevance. We have produced a new model of endothelialized reconstructed dermis that promotes the spontaneous formation of a human capillary-like network and its stabilization in vitro for a period longer than 1 month. OBJECTIVES: The aim of this work was to describe the three-dimensional structure of the capillary-like network. Thereafter we strove to study, quantitatively and qualitatively, the influence of angiogenic and angiostatic drugs on capillary-like tube (CLT) formation in vitro in the model. METHODS: The endothelialized dermis was prepared by coculturing two human cell types, dermal fibroblasts and umbilical vein endothelial cells, in a collagen sponge biomaterial. RESULTS: The visualization by confocal microscopy of the tubes present in the model showed that the endothelial structures were not cord-like but rather CLTs with well-defined lumina. Moreover, these tubes were organized in a complex network of branching structures. When angiogenic factors (vascular endothelial growth factor 10 ng mL-1 or basic fibroblast growth factor 10 ng mL-1) were added to the model, 1.8 and 1.4 times more capillaries, respectively, were observed, whereas the addition of progesterone (10 microg x mL(-1)) reduced by 2.4 times the number of tubes compared with the control. CONCLUSIONS: These results suggest that this model is a highly efficient assay for the screening of potentially angiogenic and angiostatic compounds.

Capillaries↗
PubMed2001

Effects of chronic exposure to ultraviolet B radiation on DNA repair in the dermis and epidermis of the hairless mouse.

It has previously been shown that chronic exposure to low fluences of ultraviolet B radiation reduced DNA repair capacity in mouse skin. In this study we now extend this to examine the concentration dependence and tissue dependence of this phenomenon. We found that (6-4) photoproducts were repaired considerably faster than cyclobutane dimers and that the kinetics for photoproduct removal were comparable in the dermis and epidermis. Chronic ultraviolet B irradiation significantly reduced the initial rate and extent of DNA repair. After low daily doses of ultraviolet B (6-4) photoproduct repair was most affected and after high daily doses the repair of both cyclobutane and (6-4) dimers was reduced. Whereas cyclobutane dimer repair was most affected in the dermis, reduced (6-4) photoproduct repair was observed in both tissues. The deleterious effects of chronic ultraviolet exposure were sustained for a considerable time after the chronic treatment ended.

Animals↗