Search results for "Dermis"
showing 10 items of 202 documents
Immunohistochemical markers for histopathological diagnosis and differentiation of acute cutaneous graft‐versus‐host disease
2021
Graft-versus-host disease (GvHD) is a major complication following stem-cell or solid-organ transplantation. Accurate diagnosis of cutaneous GvHD is challenging, given that drug eruptions and viral rashes may present with similar clinical/histological manifestations. Specific markers are not available. We performed the histological examination of biopsy samples from acute GvHD (aGvHD; n = 54), Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN; n = 27), maculopapular drug eruption (MDE; n = 26) and healthy controls (n = 26). Samples of aGvHD showed a decrease in Langerhans cells (LC, p = 0.0001) and an increase in macrophages (MΦ, p = 0.0001) compared to healthy skin. Compared to …
The distribution of blood group antigens in rodent epithelia
1984
The pattern of distribution of antigens cross-reacting with antibodies to human blood group antigens A and B and two precursor molecules was examined by immunofluorescence in the epidermis, oral mucosa and forestomach of rats and mice. Staining for blood group antigen A was negative. In all epithelia examined, blood group antigen B was present at the surface of basal and parabasal cells, and the H antigen at the surface of spinous cells. N-acetyllactosamine was present on the cell membranes in the upper spinous and granular cell layers of epidermis and forestomach epithelium and was not expressed in the oral epithelia except for a limited area in the dorsal tongue epithelium. Thus, the expr…
Characteristic intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat: morphological details revealed by intrav…
1999
Light microscopic observations employing intravital methylene blue staining and impregnation by the zinc iodide-osmium tetroxide technique are presented for intraepidermal nerve fibre endings of the intervibrissal fur in the mystacial pad of the rat snout. Both procedures revealed anatomical details of the intraepidermal nerve fibre plexus in epidermal hillocks often located very close to the mouths of hairs. These nerve fibres appeared to resemble those described in previous immunohistochemical studies as cluster or bush endings. The methylene blue preparations demonstrated the existence of an intensely stained enlargement at the site of the branching point of the nerve fibres which seemed…
Intraepidermal formation of Merkel cells in xenografts of human fetal skin.
1990
An experimental transplantation model using human fetal skin was applied to approach the question of the embryologic origin of human Merkel cells. Palmar and plantar skin from five fetuses, between 8 and 11 weeks of estimated gestational age (EGA), was xenografted to subcutaneous beds of nude mice. After 4 or 8 weeks of growth, biopsies were taken from these xenografts and examined for the presence of Merkel cells, using immunocytochemistry with antibodies specific for simple epithelial-type cytokeratins and neuron-specific enolase (NSE) as well as using electron microscopy. Skin from the same fetuses at the time of transplantation was screened in the same way. In all fetuses, no (or very s…
A novel monoclonal antibody to a distinct subset of cutaneous dendritic cells.
1992
A monoclonal antibody was generated by immunizing rats with Langerhans cell (LC)–enriched epidermal cells obtained from BALB/c mouse earskin after epicutaneous application of the contact sensitizer 2,4-dinitrofluorobenzene (DNFB). The antibody 4F7 detects in normal mouse skin, few dermal cells showing the morphologic, phenotypic, and functional properties of accessory dendritic cells, but lacking Birbeck granules. The capacity to stimulate allogenic T cells in the mixed leucocyte reaction resembles that of freshly isolated LCs. After DNFB application, an increased number of 4F7+ dendritic cells are found in the dermis and, in addition, some labeled dendritic cells occur in the epidermis. So…
Focal palmoplantar and gingival keratosis ? A rare genodermatoses : case report
2020
Focal palmoplantar and gingival keratosis syndrome is a rare dominant inherited disease with an early onset in life. Clinically, the condition is characterized by pressure related thickening of the epidermis of the palms and soles, usually accompanied by pain and different levels of skin involvement and thickness between patients. Recently, we observed a 38-year-old woman with multiple non-removable, painless white plaques of variable size and thickness on the attached gingiva and a white plaque widespread across the hard palate. By further questioning, the patient comments that she has thick yellowish focal plaques in both soles of her feet. Histopathological analysis revealed a hyperplast…
Primary cutaneous plasmacytosis in a child. Is this a new entity?
2002
Plasma cell proliferations represent a heterogeneous spectrum of disorders. A 7-year-old Caucasian female had suffered an asymptomatic eruption on the trunk for 4 years. Physical examination revealed a plaque with scattered red-brown papules and nodules. Chemical analysis revealed normal proteinaemia. Histological examination of biopsy specimens showed dense perivascular and periadnexal infiltrate, consisting largely of plasma cells, in the superficial and deep dermis. Immunohistochemical study showed that many cells of the infiltrate were CD20 positive. The plasma cells expressed kappa and lambda light chains. The girl's status (age; absence of hypergammaglobulinaemia, lymphadenopathy and …
Merkel cells in ontogenesis of human nails
1993
Digital skin of human fetuses is known to contain a particularly high concentration of Merkel cells. Using antibodies against the simple epithelial cytokeratins (CK) 18 and 20, which are sensitive and specific Merkel cell markers, we studied immunohistochemically the main adnexal structure of digital skin, the nail anlage, in human fetuses (9-22 weeks of gestation) for the presence of Merkel cells. As early as week 9 some clustered Merkel cells were detected in the early matrix primordium. In specimens of week 12-15, abundant Merkel cells were found in the nail anlagen, particularly in the epithelium of the proximal nail-fold and the dorsal and ventral side of the apex region. In contrast, …
Formation of Epidermal and Dermal Merkel Cells During Human Fetal Skin Development
1986
The origin of Merkel cells is still a matter of debate, specifically the question of whether they are derived from epithelial cells of the epidermis or from immigrated neural crest cells. As an argument for the latter hypothesis the occurrence of dermal, nerve-associated Merkel cells in human fetal skin has often been mentioned. Therefore, we analyzed the distribution of Merkel cells in epidermis and dermis of plantar skin of human embryos and fetuses, ranging in gestational age between 7 and 17 weeks. Merkel cells were identified by immunocytochemistry on frozen sections using antibodies against simple epithelium-type cytokeratins and by electron microscopy. In the 17-week-old fetus, 17% o…
Ultrastructural pathology of dermal axons and Schwann cells in lysosomal diseases
1988
Skin tissue specimens, obtained from 60 patients afflicted with a diverse range of lysosomal disorders revealed two groups of lesions within dermal axons, largely unmyelinated ones, particularly within axonal terminals: (1) non-specific mitochondria and dense bodies often enlarging the axonal terminal; and (2) disease-specific lysosomal residual bodies, the latter less frequent depending on the incidence and type of lysosomal disorders, i.e., largely only seen in GM2-gangliosidosis due to hexosaminidase A deficiency and mucolipidosis IV, while the spectrum of lysosomal residual bodies in Schwann cells appeared more variegated, especially due to the occurrence of vacuolar lysosomal residual …