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Increase in fibronectin in the deep dermis of involved skin in progressive systemic sclerosis.

The distribution and amount of fibronectin in both involved and uninvolved skin from scleroderma patients and controls were compared by indirect immunofluorescence. A marked increase in fibronectin was found in the deep dermis of involved scleroderma skin, while the subepidermal papillary regions of all specimens revealed little variation in fibronectin content. The districution of the accumulated fibronectin appeared to parallel that of the accumulated collagen in the involved reticular dermis.

Adult↗

Xenoplastic combinations between chick chorionic epithelium and fetal monkey dermis.

Fetel monkey dermis from the sole of the foot or ear induces the chick chorionic epithelum (CE) to form an epidermis that histologically resembles chick rather than monkey. These results support the conclusion that in epithelial-mesenchymal interactions between animals of different vertebrate classes the epithelium responds in a species-specific manner. Differences were noted, however, in the response of the avian CE to either the sole or ear dermis.

Animals↗

6-trans-leukotriene B4 is a neutrophil chemotaxin in the guinea pig dermis.

The products of the 5- and 12-lipoxygenase (5-LO, 12-LO) pathways of arachidonic acid metabolism are implicated as proinflammatory mediators in a number of disease states. 12(R)-hydroxyeicosatetraenoic acid [12(R)-HETE] is present in large quantities in human psoriatic lesional skin and can be further metabolized by 5-LO to 5(S), 12(R)-dihydroxy-(6E,8Z,10E,14Z)-eicosatetraenoic acid (6-trans-LTB4). Furthermore, leukotriene B4 (LTB4) and the sulfidopeptide leukotrienes (LTC4, LTD4) can be transformed to 6-trans-LTB4. When injected into the guinea pig dermis, 6-trans-LTB4 (1.0, 10.0, 20.0 micrograms/intradermal site) caused a significant (P less than 0.02) infiltration of polymorphonuclear leukocytes (PMN) at 4 hr as assessed by histology and the levels of the PMN marker enzyme myeloperoxidase. 6-trans-LTB4 is a more potent PMN chemoattractant than 12(R)-HETE in the guinea pig dermis but is far less potent than LTB4. Pharmacological interdiction of leukotriene production or receptor binding should take into account the proinflammatory activity of 6-trans-LTB4.

Animals↗

Effects of argon, dye, and Nd:YAG lasers on epidermis, dermis, and venous vessels.

The aim of the present study, which was performed at the dorsal aspects of the ears of guinea pigs, was to compare effects of different lasers on epidermis, dermis, and small venous vessels. Irradiations were performed with argon, dye, and Nd:YAG lasers. In the first series tissue repair processes were studied after argon laser application. Laser defects were excised after 1, 4, 8, and 14 days and were prepared for routine histological examination. The breadth of epidermal defect and extent of dermal coagulation and occlusion of vessels by thrombus formation were examined histologically. In a second series parameters of irradiation (ie, exposure time, laser power) of the three different lasers were changed systematically. Laser-induced morphological tissue changes could be best observed 24 hours after irradiation. Each of the lasers led to occlusion of vessels by thrombus formation and also coagulated epidermis and dermis. The extent of dermal and epidermal coagulation was less pronounced after dye laser application. Using short exposure times it was possible to reduce the extent of epidermal damage caused by argon and Nd:YAG lasers. Only 50-msec dye laser pulses led to intravascular thrombus formation without epidermal and dermal damage.

Animals↗

Membrane-bound structures at the interface between tumour and dermis in basal cell carcinoma. An ultrastructural study.

During an ultrastructural study of the interface area between tumour and dermis in 23 basal cell carcinoma (BCC), membrane-bound structures were noted in the dermis adjacent to the basal lamina in 12 tumours (52 per cent), but none of the controls. Serial sectioning demonstrated cytoplasmic connections between these structures and tumour cells. Their formation and interaction with adjacent stromal cells is discussed.

Basal Cell Carcinoma↗

Endoneurial mast cells in peripheral nerves of the armadillo dermis.

Electron microscopy of the dermis of the 9-banded armadillo, Dasypus novemcinctus, reveals an intimate relationship of mast cells to peripheral nerves. Mast cells are routinely found in the dermis in close proximity to nerves, and mast cells are also present within the perineurial cell sheath in the endoneurial space proper. These cells contain electron opaque granules and exhibit numerous surface folds as is characteristic of other species. The degranulation of the mast cells by injection of 0.5% aqueous trypan blue reveals sequential exocytosis of granules, similar to that described for the rat. Degranulation occurs in most dermal and endoneurial mast cells following a single intradermal injection of trypan blue. A small number of mast cells partially degranulate and a few exhibit no degranulation, suggesting a heterogeneous population. It is also noted that mitochondrial morphology differs in degranulating cells, in that they become swollen and vacuolated. The results of this study are discussed in light of previous results reported for other species, mainly at the light microscope level.

Animals↗

Psoriasiform architecture of murine epidermis overlying human psoriatic dermis transplanted onto SCID mice.

Preliminary observations in a xenogeneic SCID mouse transplantation model indicated that murine epidermis overgrows human dermis from psoriatic skin but not that form normal skin. To investigate the effect of peripheral blood mononuclear cells on the differentiation of murine keratinocytes, we transplanted involved and uninvolved full-thickness skin from patients with psoriasis onto SCID mice and followed this with repeated subcutaneous injections of cells suspended in patient serum. After 6 weeks grafts were analysed morphologically and immunohistochemically. The epidermis in grafts from clinically uninvolved skin appeared normal. The persistence of a psoriasiform epidermis was noted in all grafts from affected sites despite a lack of lymphocytic infiltration. Staining for human and mouse MHC class I antigens revealed the murine origin of keratinocytes forming the psoriasiform epidermis, while the human dermis was retained. Our observations indicate that the defect underlying the pathogenesis of psoriasis is most likely located in the dermal rather than the epidermal compartment. This xenogeneic transplantation model may be useful for future studies of the pathogenesis and treatment of psoriasis.

Animals↗

Transient immune deposits in the papillary dermis and in the epidermis. A light-microscopical study on the experimental Arthus reaction.

To have as further insight into the localizations of immune deposits in the skin the reversed passive and the passive Arthus reactions were carried out in the foot-pads skin of guinea-pigs using horseradish peroxidase as antigen. The transient localizations of immune deposits in the papillary dermis and in the epidermal cell layer were observed in the skin of the reversed passive Arthus reaction, but not in the skin of the passive Arthus reaction. Following the immune deposits in the papillae including the capillary walls and the dermoepidermal junction, the papillary dermis became widened, swollen, and edematous, being infiltrated by PMN's. In the epidermal layer, the immune deposits were found as fine granular aggregates adhering to the epidermal cells or to the dendritic cells. Although the immune deposits disappeared promptly from the papillae and the inflammatory reactions were slightly and transient, the epidermal cell layer became thickened, and several mitotic figures of the epidermal cells were observed.

Animals↗

Dermatitis herpetiformis: 'pH optimum' for the release of potentially antigen-binding IgA fragments from papillary dermis of uninvolved skin by peptic digestion.

In preparations of papillary dermis taken from clinically normal skin of patients with dermatitis herpetiformis (DH), the disappearance of granular IgA deposits induced by peptic digestion was partial at pH 4.5 and total at pH 4.1, as visualized by immunofluorescence microscopy. In a model system in which human monomeric IgA was digested by pepsin using a pepsin-IgA ratio of 100:0.3, an IgA concentration of 3 lambda g/ml and a pH range of 5.1-4.1, the degradation of IgA molecules did not appear to proceed beyond the formation of fragments corresponding to F (ab)'. When supernatants after peptic digestion of papillary dermis at pH 4.1 were analysed by sodium-dodecylsulphate (SDS)-polyacrylamide gel electrophoresis after reduction and alkylation followed by electrophoretic transfer to nitrocellulose membranes and subsequent immunochemical detection, IgA-like material corresponding to the alpha-chain part of F (ab)' fragments was found in preparations from DH patients but not in those from controls.

Dermatitis Herpetiformis↗

Comparison of DNase, DNA-polymerase and RNA-polymerase activities present in the DNA-binding proteins of normal human dermis, epidermis, horny layer and psoriatic scales.

DNA-binding proteins (DBP) of normal human dermis, epidermis, horny layer and psoriatic scales represent a tissue-specific group of mostly nuclear nonhistone proteins. To analyse their function, the different DBP fractions were examined concerning the presence of DNase, DNA-polymerase and RNA-polymerase activities. DBP of normal epidermis and horny layer contain four different DNases. One DNase of both DBP fractions is active only at pH 5.0. Three DNases of epidermal DBP are active at a pH-range from 5.0--8.5, while the corresponding DNases of horny layer-DBP are most active at pH 7.4. Probably these DNases have changed their pH-optimum during keratinisation. DBP of psoriatic scales include no activity of these three DNases and the pH 5.0-DNases seem to have reduced DNA-affinity. Human dermis DBP contain quite another set of four DNases which hardly can be correlated to the DNases of epidermal DBP. DNA-polymerase activities are present in each fraction and derive from different DNA-polymerases. Two DNA-polymerases with pI-values of 4.5 and 9.3 may correspond to beta- and alpha-DNA-polymerase of eukaryotes, respectively. Further activity of proteins which are focussed at pH 6.5--7.2 and 8.2 could be detected. The proteins represent either tissue-specific DNA-polymerases or further thymidine monophosphate incorporating enzymes. Contrary, RNA-polymerase activity could not be enriched from correlating extracts by DNA-cellulose chromatography.

DNA-Directed DNA Polymerase↗

Effect of macrophages on elimination of dermal melanin from the dermis.

To facilitate the mobilization of dermal melanin from the skin, we studied the role of macrophages in the elimination of dermal melanin in incontinentia pigmenti. The protein and melanin moieties of mouse-melanoma melanosomes were labeled with 14C and 3H, respectively. Labeled melanosomes were injected intracutaneously into the backs of guinea pigs. Carrageenan, a macrophage toxic agent, showed an inhibitory effect on the degradation and elimination of protein moiety of melanosomes from the dermis, when carrageenan was injected i.p. at the time of inoculation of melanosomes. Delayed-type inflammatory infiltrates in contact dermatitis showed some increase in the elimination of melanin moiety of melanosomes from the dermis.

Animals↗

Pharmacotoxicological applications of an equivalent dermis: three measurements of cytotoxicity.

The legal procedure for evaluating the toxicity of cosmetic, household, chemical and pharmaceutical products is still the irritancy Draize test on rabbits. Various irritation tests are currently being developed as alternatives to in vivo animal testing. Our in vitro model system is composed of 24 equivalent dermis (ED) comprising a chitosan-cross-linked collagen-glycosaminoglycan matrix populated by foreskin fibroblasts. In evaluating this system for irritancy testing, three different measures of toxicity were used: MTT (dimethylthiazol diphenyltetrazolium bromide) reduction, and lactate dehydrogenase and interleukin-6 release. The experiments described herein represent a preliminary evaluation to determine the usefulness and predictive value of our 24 ED kit as an alternative method for the prediction of human dermal reaction, versus three chemical products: cadmium chloride, lauryl sulfate, and benzalkonium chloride. Preliminary results suggest that the ED may be a useful in vitro model for the prediction of cutaneous and ocular toxicity and allow the development of a 24-skin-equivalent kit realized by seeding human normal keratinocytes onto the equivalent dermis.

Cells, Cultured↗

Reconstruction of parasacral hernia with acellular human dermis graft.

Parasacral hernias are defects through the pelvic floor which occur as the result of sacral resection. These defects are often large, and are frequently the result of treatment for sacral malignancies. This report documents the case of a 71-year-old woman who underwent radical coccygectomy and partial sacrectomy for a chordoma and subsequently presented 1 year later with a large parasacral hernia. The defect was repaired using an acellular human dermis graft with a gluteus maximus muscle-advancement flap overlay. This article summarizes the current literature of this challenging clinical problem, and examines the use of acellular human dermis in the repair of complex hernias.

Aged↗

Dermis-fat graft for orbital reconstruction after subtotal exenteration.

A surgical technique for reconstruction after subtotal orbital exenteration uses an autogenous dermis-fat graft. A musculocutaneous flap is advanced over the graft to provide the anterior vascular supply for the free dermis-fat graft. The periorbita and remaining orbital tissue provide the vascular supply posteriorly. This technique eliminates extensive skin grafting and delayed spontaneous healing. Wound healing is rapid and surgical morbidity is minimized. We have used this procedure in three patients with sebaceous gland adenocarcinoma, two patients with severe posttraumatic contracted sockets, and as a palliative procedure in one patient with a fungating choroidal melanoma and widespread metastasis.

Adipose Tissue↗

Configurational changes within the dermis of meshed split skin grafts: a histological study.

By placing a series of vertical cuts through the skin graft, the meshing process increases the area of exposed dermis. This extra dermis contains the cut ends of vessels derived from the subpapillary plexus. Histological examination has shown that each of the skin bridges within the mesh changes shape so that these vessels come to open on to the undersurface of the graft, where they are advantageously placed to participate in revascularisation of the graft.

Humans↗

Kerato-dermal grafts: the importance of dermis for the in vivo growth of cultured keratinocytes.

In a porcine model, we studied the benefit of dermis for the growth of cultured autologous keratinocytes (CAK) on full-thickness wounds isolated within skin graft chambers. Kerato-dermal grafts were prepared in a two stage process using autologous de-epidermalised dermis (DED) and CAK (Group 1). Control wounds were prepared by grafting either CAK only (Group 2) or DED only (Group 3). The median epidermal cover of 34 wounds in Group 1 was 47% and was significantly greater (p < 0.001) than the epidermal cover of 12 wounds in Group 2 (4%) and 14 wounds in Group 3 (12%). The epidermis in Group 1 was durable whereas it was fragile in the control wounds. Histologically rête ridges were present at 2 weeks in Group 1, but not in the control wounds. These data indicate that a dermal wound bed significantly improves the in vivo growth of cultured keratinocytes.

Animals↗

Differences in the histogenesis and keratin expression of avian extraembryonic ectoderm and endoderm recombined with dermis.

The responses of the chorionic ectoderm and allantoic endoderm (from 8-day chick embryos) to dermal induction were compared through tissue recombinants grafted onto the chorioallantoic membrane. The chorionic epithelium formed the appropriate epidermis with a fully developed stratum corneum in response to both spur and scutate scale dermises. Analysis of these recombinant epidermal tissues by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that tissue-specific expression of the alpha (alpha) and beta (beta) keratin polypeptides occurred. In addition, indirect immunofluorescence studies with antisera to alpha or beta keratins showed that the beta stratum, which characterizes the epidermis of spurs and scutate scales, was formed, and the alpha keratins were distributed as in the normal epidermal tissues. In contrast, although the allantoic endoderm became stratified in association with either spur or scutate scale dermis, a stratum corneum with a beta stratum did not develop. SDS-PAGE analysis demonstrated that while the characteristic beta keratins of scutate scales and spur were not detected, most of the alpha keratins normally elaborated by these structures were present, suggesting that even without histogenesis of a stratum corneum the expression of alpha keratins of endoderm could be regulated in a tissue-specific manner by dermis. This study also demonstrated that there are differences in the abilities of the chorionic and allantoic epithelia to respond to the same dermal cues, which may reflect earlier restrictions in their developmental potentials.

Allantois↗

Induction of epidermal mucous metaplasia by culture of recombinants of undifferentiated epidermis and retinol-treated dermis in a chemically defined medium.

Epidermal mucous metaplasia of cultured skin is known to be induced by excess retinol. Studies were made on whether retinol affects primarily the epidermis or the dermis during retinol-induced epidermal mucous metaplasia of 13-day-old chick embryonic skin in culture. When recombinants of 13-day-old normal epidermis and retinol-treated dermis were cultured for 7 days in chemically defined medium in the absence of retinol, hormones, and serum, they showed altered epidermal differentiation toward secretory epithelium (mucous metaplasia). Thus retinol acted primarily on dermal cells.

Animals↗