Search results for "Epidermis"

Selective AhR knockout in langerin-expressing cells abates Langerhans cells and polarizes Th2/Tr1 in epicutaneous protein sensitization

2020

The aryl hydrocarbon receptor (AhR) represents an environmental sensor regulating immune responses. In the skin, AhR is expressed in several cell types, including keratinocytes, epidermal Langerhans cells (LC), and dermal dendritic cells (DC). The mechanisms how AhR activates or inhibits cutaneous immune responses remain controversial, owing to differences in the cell-specific functions of AhR and the different activating ligands. Therefore, we sought to investigate the role of AhR in LC and langerin(+) and negative DC in the skin. To this aim, we generated Langerin-specific and CD11c-specific knockout ((−/−)) mice lacking AhR, respectively, in LC and Langerin(+) dermal DC and in all CD11c(…

Acute Necrotic Plaque in an Immunocompromised Host.

2017

Changes in Placental Morphology and their Association with Embryonic Skin Development

2019

Abstract Histogenesis and organogenesis in mammals normally transpires in a hypoxic environment. Oxygen diffusing capacity is dependent on diffusion distance, which may vary with the thickness of placental barrier and with the level of tissue vascularity. Since the epidermis is avascular, its development fully depends on dermal blood vessels. Despite the large number of studies focusing on uteroplacental circulation and embryogenesis, it is clear that the current knowledge of how placental changes in pregnancy contribute to skin development is incomplete. The aim of this study was to evaluate the association between structural changes in the placental barrier and development of the integume…

Down-Regulation of CD62L Shedding in T Cells by CD39+ Regulatory T Cells Leads to Defective Sensitization in Contact Hypersensitivity Reactions

2016

Injection of regulatory T cells (Tregs) followed by sensitization with 2,4,6-trinitrochlorobenzene induced a transient increase in size and cellularity of skin-draining lymph nodes (LNs) in mice. This led us to hypothesize that Tregs may affect the trafficking of T cells from and to peripheral LNs. Two to three hours after sensitization, we found fewer CD8+ T cells expressing CD62L in LNs compared with untreated controls. Injection of wild-type Tregs prevented this down-regulation of CD62L. In contrast, Tregs devoid of the adenosine triphosphate (ATP)-degrading ecto-enzyme CD39 were unable to do so. As for the mechanism of CD62L regulation, we found that ATP, which is released in skin upon …

The mammary pheromone of the rabbit: from where does it come?

2005

Newborn rabbits, Oryctolagus cuniculus, are directed to their mother's nipples by specialized odour cues. Previous investigations have suggested that these cues are released from the doe's abdominal surface from structures located around the nipple. We tested pups with samples of various cutaneous tissues or fluids collected from lactating females to determine the location of the source of the odour cues. After finding that the nipples from lactating does were more attractive than those of virgin females, we conducted three experiments using skin samples collected at increasing distance from the nipples, dermal and mammary tissues taken below the nipples, and milk collected at different lev…

Epithelial markers and differentiation in adnexal neoplasms of the skin: an immunohistochemical study including individual cytokeratins

1995

Applying immunohistochemical procedures for the detection of eight different cytokeratin (CK) polypeptides and other differentiation markers, we compared the staining patterns of normal cutaneous structures with those of benign adnexal tumors (n = 65). Syringomas exhibited a marker pattern highly reminiscent of that seen in normal dermal eccrine ducts (EMA in peripheral cells, CK 10 in intermediate cells, and CK 6, CK 19, and CEA in luminal cells). Nodular hidradenomas exhibited complex patterns suggesting relationship between tumor cells, including clear cells, and normal secretory coil cells (CK 7, CK 8, CK 19, and EMA); however, dermal-duct and epidermoid differentiation were also detect…

Enhancing effect of alpha-hydroxyacids on "in vitro" permeation across the human skin of compounds with different lipophilicity.

2005

The percutaneous penetration-enhancing effects of glycolic acid, lactic acid and sodium lauryl sulphate through the human epidermis was investigated using 5-fluorouracil as a hydrophilic model permeant and three compounds belonging to the phenylalcohols: 2-phenyl-ethanol, 4-phenyl-butanol and 5-phenyl-pentanol. The lipophilicity values of the compounds ranged from log Poct -0.95 to 2.89. The effect of the enhancer concentration was also studied. Skin pretreatment with aqueous solutions of the three enhancers did not increase the permeability coefficient of the most lipophilic compound (log Poct = 2.89). For the other compounds assayed, the increase in the permeability coefficients depended …

Distribution of a special subset of keratinocytes characterized by the expression of cytokeratin 9 in adult and fetal human epidermis of various body…

1987

Biochemical analyses have previously shown that palmar and plantar epidermis, unlike the epidermis of other body sites, contain cytokeratin 9 (Mr 64,000), an unusually large acidic (type I) cytokeratin. Guinea-pig antibodies that specifically and selectively react with bovine and human cytokeratin 9 were used for the immunocytochemical identification of cytokeratin 9 in adult and fetal human epidermis from various body sites. In the epidermis of palms and soles, antibodies against cytokeratin 9 stained a high proportion of the keratinocytes in suprabasal locations. These suprabasal cytokeratin-9-positive keratinocytes were often arranged in vertical columns and concentrated around intraepid…

Inhibition of skin inflammation by baicalin ultradeformable vesicles.

2016

The topical efficacy of baicalin, a natural flavonoid isolated from Scutellaria baicalensis Georgi, which has several beneficial properties, such as antioxidative, antiviral, anti-inflammatory and antiproliferative, is hindered by its poor aqueous solubility and low skin permeability. Therefore, its incorporation into appropriate phospholipid vesicles could be a useful tool to improve its local activity. To this purpose, baicalin at increasing concentrations up to saturation, was incorporated in ultradeformable vesicles, which were small in size (∼67nm), monodispersed (PI<0.19) and biocompatible, regardless of the concentration of baicalin, as confirmed by in vitro studies using fibroblasts…

High CCL27 immunoreactivity in ‘supratumoral’ epidermis correlates with better prognosis in patients with cutaneous malignant melanoma

2016

AimsIt has been proposed that the expression of chemokines and chemokine receptors by melanoma cells may have a role in tumour immune escape. Chemokine CCL27 is reported to be expressed specifically on the epidermal keratinocytes. The implication of CCL27 in cutaneous melanomas is currently unresolved. It has been suggested that CCL27 expression in melanomas can induce antitumoral immunity, and that CCL27 may suppress tumour growth probably due to the local lymphocyte recruitment.MethodsWe studied CCL27 chemokine expression in three different concentric epidermal areas covering the primary cutaneous melanoma in patients with a long clinical follow-up. Our study included 91 cases of primary …