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Results for “Dermis”

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PubMed1986

Selective decrease of 15-hydroxyeicosatetraenoic acid (15-HETE) formation in uninvolved psoriatic dermis.

Epidermis of psoriatic skin lesions is characterized by elevated 5-lipoxygenase and 12-lipoxygenase products. 15-hydroxyeicosatetraenoic acid (15-HETE), the predominant lipoxygenase product in normal dermis, has the potential to inhibit 5-lipoxygenase and 12-lipoxygenase. The purpose of the present study was to determine the capacity of homogenized dermis from uninvolved psoriatic skin to form 15-HETE in vitro. Extracted lipids were separated by reversed-phase high-performance liquid chromatography. Each chromatographic peak was identified by its coelution with authentic standards, by ultraviolet spectrometry, and by radioimmunoassay. Dermis from uninvolved psoriatic skin generated on average 48% less 15-HETE than normal dermis (P less than .01). In contrast, the formation of 12-hydroxyeicosatetraenoic acid was increased by 56% in psoriatic dermis (P less than .01). Prostaglandin E2 formation was similar in normal and psoriatic dermis. Since 15-HETE can inhibit the synthesis of 5-lipoxygenase and 12-lipoxygenase products that possess inflammatory and proliferative capacities, a defective 15-HETE generation in dermis may be of importance for the development of psoriasis.

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

PubMed1994

Recovery of antioxidants and reduction in lipid hydroperoxides in murine epidermis and dermis after acute ultraviolet radiation exposure.

In previous studies we have found that a single acute dose of ultraviolet radiation to murine skin causes a large degree of destruction of enzymic and non-enzymic antioxidants immediately after irradiation. In the present study, we wished to elucidate the recovery of antioxidants after a single dose of ultraviolet (UV) radiation. We measured antioxidants and lipid hydroperoxides (as a marker of membrane damage) in murine epidermis and the dermis at 0, 3, 12, 24, 72 and 120 h after exposure to UV radiation (25 J/cm2, UVA+UVB). Lipid hydroperoxides showed the highest values immediately after UV exposure and returned to control values within 24 h in both epidermis and dermis. The activities of catalase, glutathione peroxidase and glutathione reductase showed the lowest activities immediately after UV exposure; superoxide dismutase activities reached a minimum at 3 h postexposure. The pattern of recovery was different for each enzyme and for epidermis and dermis. The activities of superoxide dismutase and catalase decreased remarkably and recovered slowly. Superoxide dismutase in the dermis recovered full activity by 120 h and in the epidermis by 12 h. Catalase activity in both epidermis and dermis had returned to only 50% of control activity at 120 h, although the epidermis showed a temporary increase (to 93%) at 24 h. Glutathione peroxidase and glutathione reductase were slightly decreased immediately after irradiation, recovered to 100% at 3 h and then increased to 200-250% in both the epidermis and the dermis at various times; values had returned to 100% in epidermis by 120 h but remained elevated in dermis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2004

Long-distance cue from emerging dermis stimulates neural crest melanoblast migration.

Neural crest melanoblasts display unique navigational abilities enabling them to colonize the dorsal path between ectoderm and somite. One signal shown here to elicit melanoblast migration is a chemotactic cue supplied by the emerging dermis. Until dermis emerges, melanoblasts fail to enter the dorsal path. The dermis emerges from a site that is too distant to stimulate migration by cell contact. Instead, surgeries show that dermis elicits migration from a distance. When dermis is grafted distally, neural crest cells enter the path precociously. Moreover, large grafts recruit melanoblasts from the control sides (without increasing crest cell numbers) as well as a few crest cells from ventral somite. Because other grafted tissues fail to stimulate migration, the dermis stimulus is specific. This report is the first documentation that trunk neural crest cells can be guided chemotactically. It also extends evidence that migration is exquisitely sensitive to temporal-spatial patterns of somite morphogenesis. Developmental Dynamics 229:99-108, 2004.

Animals↗

PubMed2006

Clonal characterization of fibroblasts in the superficial layer of the adult human dermis.

The dermis of adult human skin contains a physiologically heterogeneous population of fibroblasts that interact to produce its unique architecture and that participate in inflammatory and wound repair functions in vivo. This heterogeneity has been well documented for fibroblasts located in the superficial papillary dermis and the deep reticular dermis. However, the existence of diverse fibroblast subpopulations within a given region of the dermis has not been explored. In this study, fibroblast cultures have been established from the superficial dermis following enzymatic dissociation of the tissue. These fibroblasts have been cloned by limiting dilution and initially selected on the basis of morphology and proliferation kinetics. Fibroblasts in some of the clones selected for study express alpha-smooth muscle actin, a myofibroblast characteristic. Significant differences for fibroblast clones obtained from the same piece of skin have been observed with regard to their rate of collagen lattice contraction, their ability to organize a fibronectin matrix, their release of specific growth factors/cytokines into culture medium, and their response to interleukin-1alpha. These differences in both morphological and physiological characteristics indicate that the superficial papillary dermis contains a heterogeneous population of fibroblasts. This heterogeneity might indicate that diverse subpopulations of fibroblasts are required to interact in both homeostatic and pathological situations in skin.

Actins↗

PubMed2005

The use of dermis grafts after discectomy for internal derangement of the temporomandibular joint.

PURPOSE: The aim of this retrospective clinical study was to review the outcomes of temporomandibular joint (TMJ) discectomy with autogenous dermis used as an immediate interpositional graft in patients with advanced internal derangement of the TMJ. PATIENTS AND METHODS: Thirty-five joints in 29 patients who presented with advanced internal derangement of the TMJ with degenerate and irreparable discs were identified and included in the study. All patients underwent a TMJ arthrotomy (including 6 bilateral TMJ procedures) that involved removal of the disc (discectomy) and immediate replacement with autogenous dermis graft. Patients were followed up for an average of 2 years. RESULTS: There was a mean +6.7-mm improvement in maximum interincisal opening, a 66% mean improvement in pain ( P < .001), and a 42% mean improvement in function ( P < .05) after TMJ discectomy with immediate dermis graft replacement. After an average follow-up period of 24.6 months, patients reported good to excellent improvement in their TMJ symptoms in 30 of the 35 joints (85.7%). All patients showed radiologic evidence of varying degrees of condylar remodeling at 6 months or later after surgery. Of the 7 patients who had magnetic resonance imaging (MRI) performed at 6 months or later after surgery, none showed any radiologic evidence of the dermis graft. No clinical evidence of joint sounds such as crepitus was found in 33 of the 35 operated joints. CONCLUSIONS: This study found that TMJ discectomy can have a significant positive effect on the management of patients with advanced internal derangement of the TMJ who fail to respond to less invasive measures such as splint therapy and TMJ arthroscopy. However, the only advantage of dermis grafts over no grafts seems to be that it can minimize or eliminate joint sounds such as crepitus in the discectomized TMJ. In this study, the dermis grafts did not prevent regressive remodeling of the mandibular condyles.

Adolescent↗

PubMed2005

[Dermis collagens: beyond their structural properties].

The extracellular matrix is a complex network composed of macromolecules such as collagens, proteoglycans and elastin that strongly interact with each other and with cells to maintain the structural integrity of many tissues. These interactions also sustain important cell programs such as migration, proliferation, differentiation and apoptosis. The skin, and more specifically the dermis, contains an extreme diversity of macromolecules that reflects the importance of the composition and organization of the matrix components in providing physical properties and function of the tissues. The most abundant matrix components are the collagens that form a super-family of 27 different members which are divided into different subgroups. The fibrillar collagens, types I, III and V, the FACIT collagens, types XII, XIV and XVI, and collagen VI are all expressed in the collagen-rich dermis. Although the structural features of these collagens are now well characterized, their functions remain elusive. Mutations in human collagen genes give rise to numerous connective tissue diseases including dermis disorders. For example, clinical manifestations in the classical Elhers-Danlos syndrome caused by collagen V gene mutations occur predominantly in the dermis. However, the genotype-phenotype relationship is not clearly established as well as the relation between the distribution and the function of the collagens in dermis. There is no doubt that the ongoing and future work using in vivo approaches will provide new cues regarding the function of collagens in dermis.

ADAM Proteins↗

PubMed2001

The autogenous dermis-fat orbital implant in children.

PURPOSE: The autogenous dermis-fat graft orbital implant is one alternative for volume augmentation in the adult anophthalmic socket. We have reviewed our experience with dermis-fat grafts after primary enucleation in the pediatric population. METHODS: We reviewed the clinic charts of all patients under 8 years of age who underwent primary enucleation combined with dermis-fat graft implantation. We assessed subsequent orbital growth by measuring lid and fissure symmetry, superficial soft tissue socket volume, prosthetic fit, and periorbital symmetry. All measurements were obtained by 2 of the authors. RESULTS: Eight children had primary enucleations combined with a dermis-fat implant (Table 1). Age at the time of surgery ranged from 1 week to 8 years. Indications for enucleation were retinoblastoma (4), malignant teratoid medulloepithelioma (1), blind, painful eye secondary to trauma (2), or phthisis secondary to end-stage retinopathy of prematurity (1). Two patients were lost to follow up at 3 months and 6 months post enucleation. The remaining 6 patients had between 1 year and 6 years of follow up. All implants maintained appropriate volume allowing proper prosthetic fit and facial symmetry. Two children experienced excessive growth of their implants, managed by surgical debulking. Two children developed a central graft ulcer, managed by superficial revision and reclosure. CONCLUSIONS: We have observed that dermis-fat grafts in pediatric primary enucleations demonstrate good maintenance of orbital soft tissue volume and periorbital symmetry. The complications of excessive dermis-fat growth or central ulceration were easily corrected. We feel this is a promising implant for the pediatric anophthalmic socket.

Adipose Tissue↗

PubMed2002

The modification of scaffold material in building artificial dermis.

Type X collagen is principal extracellular matrix (ECM) in natural dermis. To prepare artificial dermis, collagen is traditional, and most superior biomaterial. But beside collagen, the dermis also contains many other ECM. Among them, glycosaminoglycan (GAG) is another important substance. To imitate the natural dermis, and modificate the scaffold materials, two types of scaffolds were prepared: one is traditional type X collagen spongy scaffold, the other is collagen-chondroitin sulfate (CS) spongy scaffold. Collagen was blended with CS, one kind of GAG, and cross-linked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC). Dermis fibroblast was isolated from neonate prepuce, and dermis fibroblasts were cultured on the scaffolds. The physical and chemical properties of the scaffolds were tested, including SEM, DSC, H&E staining, immunohistochemical staining and CS content analysis and so on. The results indicated that EDC is an effective and non-cytotoxic cross-link reagent, and attaching CS into collagen scaffold could improve the stability and histocompatibility of scaffold.

Animals↗

PubMed1999

Morphea limited to the superficial reticular dermis: an underrecognized histologic phenomenon.

Morphea (localized scleroderma) is a disease of unknown etiology, presenting as circumscribed areas of indurated skin. Histologically, most cases of morphea feature thickened collagen bundles in the deep reticular dermis, sometimes also extending into the superficial dermis or into the subcutis. We present six cases of morphea in which typical histologic features were restricted to the superficial dermis and contrast these with 27 additional biopsies of conventional morphea seen during the same time period. Sections were stained for elastic fibers, and dermal dendritic cells were labeled with antibodies to CD34 and Factor XIIIa. All six cases showed thickened collagen bundles restricted to the superficial dermis, sparing the deep dermis and without associated evidence of lichen sclerosus et atrophicus (LSA). Dermal elastic fibers were not appreciably decreased in number. There was loss of CD34-positive dermal spindle cells in each of our six superficial examples of morphea, which was restricted to the area of altered collagen in four of the six cases. This report highlights the distinctly uncommon phenomenon of morphea presenting solely as alteration of the superficial reticular dermis, without features of LSA. The selective loss of CD34-labeled spindle cells may provide information regarding the role of these putative immune accessory cells in morphea. Recognition of this manifestation of morphea may be helpful diagnostically.

Adult↗

PubMed2005

Use of the artificial dermis for free radial forearm flap donor site.

The radial forearm free flap has been popular in many area of reconstructive surgery. Despite the many attributes of this flap in surgical reconstruction, one of the clear disadvantages has been the morbidity of the donor site. To solve problems associated with closure of the radial forearm flap donor site, the artificial dermis was used for better outcome in the donor site. From July of 2001 to October 2003, 13 patients (12 male, 1 female) ranging in age from 27 to 67 years underwent free radial forearm transfers. Flap size measured 49 to 144 cm2. Donor-site defects secondary to the flap elevation was closed first with the artificial dermis (Terudermis), marketed by Terumo Inc, Japan, and secondary split-thickness skin graft to the artificial dermis was performed in 15 days (range, 13 to 17 days) on average. There was no flap failure in all cases. Partial loss of the artificial dermis graft was noticed in 2 cases, but it was negligible. Secondary skin graft take was noticed in about 7 days, and there was no remarkable skin graft loss. The artificial dermis was used successfully in 13 patients with the donor defects of free radial forearm flap. Despite the disadvantage to need the secondary split-thickness skin graft, use of the artificial dermis gave us not only soft-tissue augmentation and graft-skin quality similar to full-thickness skin graft but also fast graft healing and diminished morbidity of the skin-graft donor site.

Adult↗

PubMed2005

Evaluation of a sunscreen photoprotective effect by ascorbic acid assessment in human dermis using microdialysis and gas chromatography mass spectrometry.

Ultraviolet irradiation causes adverse effects like sunburn, photosensitivity reactions or immunologic suppression. The aim of this study was to evaluate the photo-protective outcome of a sunscreen cream (SPF8) by the determination of erythema indexes and the assessment of ascorbic acid and its metabolites in human dermis. These substances were used as markers of oxidative effect. Eight healthy female subjects were enrolled in this study. Two abdominal areas were exposed to solar simulated irradiation with three minimal erythema dose, one with SPF8 application and the other site without SPF8 application. Two other areas were used as control, one without SPF8 application and the other site after SPF8 application. Ascorbic acid and its metabolites (dehydroascorbic acid, threonic acid, oxalic acid and xylose) were collected from human dermis by microdialysis and assessed by gas chromatography mass spectrometry. Irradiated site without sunscreen application had significantly demonstrated lower dermis ascorbic acid concentrations and a higher erythema index than the three other sites (P < 0.05). Threonic acid, oxalic acid and xylose dermis concentrations were significantly higher in site III than in the control site I (P < 0.05). The protected-irradiated site did not show erythema formation and there was stability of ascorbic acid dermis concentrations with non-variation in its metabolites. The assessment of ascorbic acid and its metabolites in human dermis could be an efficient tool to demonstrate the oxidative process and consequently to control the efficiency of sunscreen creams against undesirable UV effects.

Adult↗

PubMed2001

Microdialysis can detect age-related differences in glucose distribution within the dermis and subcutaneous adipose tissue.

BACKGROUND: Intrinsic (chronological) cutaneous aging is a continuous and complex process. Limitation in nutrient supply to the skin could contribute to this process. OBJECTIVE: Our study focused on the impact of age on glucose supply to human skin and its distribution within the dermis and subcutaneous adipose tissue. METHODS: An oral glucose load (100 g) was given to healthy volunteers of two age groups (24 +/- 4 and 59 +/- 10 years, n = 4 for each group). Dialysate concentrations of glucose and glycerol were monitored by microdialysis in the dermis and adipose tissue. RESULTS: Baseline tissue [glucose] did not differ significantly between the two groups. After the glucose load, dialysate [glucose] of the dermis peaked between 60 and 80 min and between 80 and 120 min in the young and old groups, respectively. In the old group, dialysate [glucose] was significantly higher in the dermis than adipose tissue at 80, 100, 120, 160 and 180 min after the load. The sum of the areas under the curve (dermis + adipose tissue) did not differ significantly between the two age groups. CONCLUSIONS: Aging is accompanied by an increased diffusion barrier for glucose between the dermis and adipose tissue.

Adipose Tissue↗

PubMedDate not supplied

Iron and ascorbic acid concentrations in human dermis with regard to age and body sites.

BACKGROUND: Reactive oxygen species (ROS) contribute to processes relating to cutaneous aging. Iron catalyses ROS formation whereas ascorbic acid (AA) plays a fundamental role in defending the organism against undesirable ROS action. OBJECTIVE: The aim of this work was to determine the ex vivo iron and AA concentrations in human dermis from different age groups to better understand their role. METHODS: Skin fragments were collected from 66 female patients during surgical operations and were grouped according to age: group I (<15 years, before puberty, n = 12), group II (15-50 years, adults, n = 42), and group III (>50 years, advanced age adults, n = 12). Two sites were investigated: the abdomen (unexposed areas) and face (exposed sites). Iron and AA were collected from human dermis by microdialysis and assessed by atomic absorption spectrometry and gas chromatography mass spectrometry, respectively. RESULTS: Iron concentrations in the dermis were significantly higher in group III (27.4 +/- 20.9 microg/l) than in group I (13.8 +/- 3.3 microg/l; p< 0.05 ). An inverse correlation between AA dermis levels and increasing age was detected. For groups III and I, iron and AA concentrations were significantly different in dermis from the face compared to that of the abdomen (p < 0.05). CONCLUSION: This study shows for the first time that there is a direct relationship between iron and AA concentrations in the dermis and aging. Moreover, iron and AA concentrations differed according to body site.

Abdomen↗

PubMed2001

Iron concentrations in human dermis assessed by microdialysis associated with atomic absorption spectrometry.

Until recently, the determination of metallic elements concentrations in normal skin, in vivo, was rare due to the lack of non-invasive techniques. Microdialysis has the advantage of being slightly invasive when applied to the collection in vivo of endogenous or exogenous substances from the skin. Iron is an active element in different cutaneous disorders. The aim of this work was to assess iron by atomic absorption spectrometry (AAS) after the collection of samples by microdialysis from human dermis. A first essential step, before determining the in vivo iron concentration in human dermis, was to establish an experimental protocol applicable to ex vivo as well as in vivo conditions. For this reason, this work deals only with the assessment of iron in ex vivo human dermis. A skin microdialysis technique and a calibration method, the No Net Flux, were used to quantify basal iron concentrations in human dermis and the same method was also used to determine in vitro and ex vivo iron recoveries. No differences were detected between in vitro and ex vivo recoveries. Ex vivo basal iron dermis concentrations ranged from 3.6 to 7.7 microg/l. This study shows that non-invasive microdialysis is an efficient method for sampling iron from human skin. A sensitive and accurate AAS technique was able to assess low iron concentrations in human dermis. The strategy adopted for this work was efficient and appropriate for the determination of iron in human skin and experiments will be carried out in vivo.

Dermis↗

PubMed2003

Dynamic mechanical properties of body-wall dermis in various mechanical states and their implications for the behavior of sea cucumbers.

The dermis of the sea cucumber body wall is a typical catch connective tissue that rapidly changes its mechanical properties in response to various stimuli. Dynamic mechanical properties were measured in stiff, standard, and soft states of the sea cucumber Actinopyga mauritiana. Sinusoidal deformations were applied, either at a constant frequency of 0.1 Hz with varying maximum strain of 2%-20% or at a fixed maximum strain of 1.8% with varying frequency of 0.0005-50 Hz. The dermis showed viscoelasticity with both strain and strain-rate dependence. The dermis in the standard state showed a J-shaped stress-strain curve with a stiffness of 1 MPa and a dissipation ratio of 60%; the curve of the stiff dermis was linear with high stiffness (3 MPa) and a low dissipation ratio (30%). Soft dermis showed a J-shaped curve with low stiffness (0.3 MPa) and a high dissipation ratio (80%). The strain-induced softening was observed in the soft state. Stiff samples had a higher storage modulus and a lower tangent delta than soft ones, implying a larger contribution of the elastic component in the stiff state. A simple molecular model was proposed that accounted for the mechanical behavior of the dermis. The model suggested that stiffening stimulation increased inter-molecular bonds, whereas softening stimulation affected intra-molecular bonds. The adaptive significance of each mechanical state in the behavior of sea cucumbers is discussed.

Adaptation, Biological↗

PubMed1999

Morphometric analyses of the development of dermis in human fetuses.

In this study, the morphometric differences of the different dermis regions during the development of the human fetus were investigated. The different dermis regions, namely, cranial, femoral and plantar (sole) parts of 40 fetuses which were between 12th-23.5th week gestation age were obtained from maternity hospital and after the routine H&E histological procedure, the measurement was performed with ocular micrometer. The first sharp increase was observed in the dermis of cranial region. It has been suggested that the thickness of the dermis is dependent on the collagen and elastic fibres, but the flexibility of the dermis is dependent on the number and the structure of the elastic fibres. The early beginning of the increase of the dermis thickness in the cranial part may be due to the effect of the cranio-caudal stimulation on the production of the collagen and elastic fibres in the embryonic term.

Dermis↗

PubMed1994

Stereological analysis of collagen and elastic fibers in the normal human dermis: variability with age, sex, and body region.

Normal human dermis has been analyzed using stereological methods to estimate the quantitative modifications of collagen and elastic fibers in relation to age, sex, and body region. Forty-five skin biopsies from the trunk or the limbs of 26 males and 19 females of different age were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin. The relative volumes of collagen and elastic fibers were calculated by the point counting method on 1 micron semithin sections. Photographic sampling was performed on four consecutive dermis layers: the papillary layer and three consecutive layers of reticular dermis. The data were subjected to analysis of variance which showed that all the factors studied exert a significant influence on the relative amounts of collagen and elastic fibers. The fractional volume of collagen fibers is constant throughout all dermis layers analyzed and is always higher in females than in males, except for the second and third decades of life. Collagen fiber density increases with age in both sexes up to 30-40 years, when it starts decreasing. Both the relative volumes and the diameters of elastic fibers increase from papillary to deep reticular dermis. In reticular dermis of both sexes there is an increment of elastic fiber density in the first decade of life, followed by a drop particularly marked in males. After 20 years, the relative volume of elastic fibers displays a decreasing trend in females, whereas it increases in males, attaining the highest values beyond the 40s.

Adolescent↗

PubMed1977

Epidermal-dermal tissue interactions between mutant foot skin and normal back skin: a comparison of the inductive capacities of scaleless low line and normal anterior foot dermis.

The inductive capacities of 9- to 16-day anterior foot dermis of scaleless low line and normal embryos were compared by recombining them with a common source of epidermis, i.e., 7-day normal back epidermis. Tissue recombinants were cultured as grafts to the chorioallantoic membrane (CAM). Both normal and scaleless low line dermis of 12 to 13 days of incubation began to lose their ability to elicit feather production in 7-day normal back epidermis. Normal foot dermis began to elicit scale production at 12 to 13 days, whereas scaleless low line anterior foot dermis maintained feather production at a low level. It is inferred that without being associated with scale placode formation, scaleless low line anterior foot dermis does not acquire specific inductive capacities related to the production of an outer scale surface in the overlying epidermis. Feather placodes do not function as surrogates of scale placodes. The difference between normal and scaleless low line anterior foot dermis in terms of specific inductive capacities related to scale production is interpreted as a secondary effect of the action of the scaleless allele in interfering with scale placode formation in the scaleless low line anterior foot epidermis.

Animals↗