Search results for "Dermis"
showing 10 items of 202 documents
Local reactions to tick bites
2008
A retrospective histological and immunohistochemical study has been carried out in 25 cases of tick bites recorded in our Departments. The samples that included an attached tick showed a cement cone anchoring the mouthparts to the skin and a blood-soaked, spongiform appearance of the superficial dermis, with a mild neutrophilic and eosinophilic infiltration. The vessels displayed a loose multilayered endothelial proliferation, with plump endothelia, permeated with erythrocytes. A few of them were severed, allowing copious blood extravasation. The established lesions included the following: erythema chronicum migrans-like cases, foreign body granulomas-sometimes containing remnants of the mo…
Immunohistological and immunoelectron microscopic identification of TNF alpha in normal human and murine epidermis.
1992
The presence, distribution and cellular localization of tumour necrosis factor-alpha (TNF alpha) were investigated in normal human and murine epidermis using immunohistological and immunoelectron microscopic methods with monoclonal and polyclonal antibodies. The immunostaining revealed an intercellular plasma membrane and cytoplasmic labelling of the epidermal keratinocytes, but no labelling of Langerhans cells, melanocytes and Merkel cells. Large amounts of TNF alpha were regularly found in the sebaceous glands. These findings demonstrate that epidermal keratinocytes and especially sebocytes produce and release TNF alpha and that this keratinocyte-derived cytokine may be important for the …
Circumscribed palmar or plantar hypokeratosis: a distinctive epidermal malformation of the palms or soles.
2002
Abstract Background: Epidermal malformations of the skin include a group of heterogeneous developmental defects that result from errors in morphogenesis of the epidermis during intrauterine life. Objective: The purpose of this study was to report the clinical and histopathologic features of a distinctive epidermal malformation involving the skin of the palms or soles. Methods: Ten patients were included in this study. All of them showed the same clinical features that consisted of a solitary circumscribed and circular area of erythematous depressed skin on the palm or on the sole. Diagnosis was confirmed by histopathologic study. Results: All patients were middle aged or elderly. Nine patie…
Stimulation of T cells by autologous mononuclear leukocytes and epidermal cells in psoriasis.
1986
Based on reports suggesting aberrant cell-mediated immunity and altered infiltration of immunocompetent cells into the skin in psoriasis, we studied the stimulation of T cells by autologous non-T mononuclear leukocytes (autologous mixed lymphocyte reaction, AMLR) and by epidermal cells isolated from lesional and clinically uninvolved skin in psoriasis (autologous mixed epidermal cell lymphocyte reaction, AMECLR). Age- and sex-matched individuals served as controls. We found that the AMLR in psoriasis (n = 11) was similar to that in healthy controls (n = 16); furthermore, cell proliferation was alike in the presence of either 5% AB-serum or autologous serum. By contrast, while the AMECLR in …
Age-related dermal collagen changes during development, maturation and ageing - a morphometric and comparative study.
2014
The tissue organisation of dermal collagen is gaining importance as a contributing factor both in development and ageing, as well as in skin maturation processes. In this work we aim to study different representative parameters of this structural organisation in 45 human skin samples of assorted ages, by means of image analysis. The variation of these parameters on the basis of age was assessed using several regression models (linear, quadratic and cubic). The area occupied by collagen was significantly reduced as a function of age in the papillary dermis (R(2) = 0.437, P < 0.0001), as well as the thickness of the collagen bundles (R(2) = 0.461, P < 0.0001), following statistical models of …
Induction of bone morphogenetic protein-6 in skin wounds. Delayed reepitheliazation and scar formation in BMP-6 overexpressing transgenic mice.
1998
Growth factors of the transforming growth factor-beta superfamily are involved in cutaneous wound healing. In this study we analyze the expression of the bone morphogenetic protein-6 (BMP-6) gene, a transforming growth factor-beta related gene, in skin wounds. In normal mouse skin high levels of BMP-6 mRNA and protein are expressed by postmitotic keratinocytes of stratified epidermis until day 6 after birth. BMP-6 expression is strongly reduced in adult epidermis with diminished mitotic activity. After skin injury we found large induction of BMP-6-specific RNA and protein in keratinocytes at the wound edge and keratinocytes of the newly formed epithelium as well as in fibroblast shaped cell…
Immunohistochemical localization of filaggrin in benign, premalignant and malignant cervical tissue.
1994
Epithelial distribution of filaggrin, a histidine-rich protein related to squamous terminal differentiation, was investigated in 87 cervical biopsies using an avidin-biotin-peroxidase technique with a monoclonal anti-human filaggrin antibody (AKH1). Normal squamous cervical epithelium exhibited a positive homogeneous immunoperoxidase stain in the upper parabasal, intermediate and superficial cell layers. Similar findings were obtained in cervical condylomas, although full-thickness staining was observed in 35.7% of the cases (P < 0.001). Filaggrin expression in CIN was inversely related to the severity of the lesion (P < 0.001). An irregular staining pattern was present in most high-grade C…
Enhancement of nortriptyline penetration through human epidermis: influence of chemical enhancers and iontophoresis.
2008
Abstract Different known percutaneous chemical enhancers and iontophoresis have been tested in-vitro to study their ability to increase transdermal absorption of nortriptyline hydrochloride (20 mg mL−1). The chemicals 1-dodecanol, Span 20, Azone, (R)-(+)-limonene or isopropyl myristate were used as an overnight pretreatment at 5% (w/w) in ethanol. Furthermore, isopropyl myristate (20%, w/w) and propylene glycol (15%, w/w) were tested in the same vehicle. Iontophoresis was applied directly to the nortriptyline hydrochloride donor solution for three different concentrations (20, 2 and 0.5 mgmL−1). The chemical enhancers slightly increased the nortriptyline transdermal flux but iontophoresis w…
A pigmented papule acting like a playful ghost: dermoscopy of three targetoid hemosiderotic hemangiomas
2018
Targetoid hemosiderotic hemangioma represents an uncommon, distinctive, benign lympho-vascular lesion, with a variable clinical appearance, typically occurs in the lower limbs and trunk. Most patients are in their 20's or 30's. We describe three dermoscopic cases followed by the review of the literature. Dermoscopic images have been collected and have been evaluated for the presence of dermoscopic features. Concerning the review, we researched on pubmed and records were reviewed noting patient age of onset, sex, location, overall size, dermoscopic appearance. The harmonic mean age of patients was 31 years; the female-to-male ratio was 1:1, and the most common locations were lower extremitie…
Anti-Aging Effects of GDF11 on Skin
2020
International audience; Human skin is composed of three layers: the epidermis, the dermis, and the hypodermis. The epidermis has four major cell layers made up of keratinocytes in varying stages of progressive differentiation. Skin aging is a multi-factorial process that affects every phase of its biology and function. The expression profiles of inflammation-related genes analyzed in resident immune cells demonstrated that these cells have a strong ability to regenerate adult skin stem cells and to produce endogenous substances such as growth differentiation factor 11 (GDF11). GDF11 appears to be the key to progenitor proliferation and/or differentiation. The preservation of youthful phenot…