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Spinous Layer (spinous + layer)
Selected AbstractsFebrile Ulceronecrotic Mucha-habermann Disease: a Rare, Severe VariantJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2006Michele M. Thompson A 56 year old Hispanic man presented with extensive ulcerative skin lesions, involving his lower trunk, groin and upper legs, severe pain and a temperature of 38.7 degrees Celsius. He was admitted to the Medical Intensive Care Unit for empiric intravenous antibiotics. Several biopsies were performed. In the following days his condition worsened and ulcerative lesions involved nearly all of his skin. Previous biopsies were consistent with pityriasis lichenoides et varioliformis acuta (PLEVA), however, neither this, nor others in the histological differential diagnosis, fit his severe and worsening clinical picture. Histology revealed vacuolar alteration with dyskeratotic keratinocytes and a superficial perivascular mixed infiltrate of lymphocytes and eosinophils. There was confluent parakeratosis containing neutrophils, and a diminished granular layer with pallor in the upper portion of the spinous layer. Immunofluorescence studies were negative. These findings were consistent with PLEVA. A clinical diagnosis of febrile ulceronecrotic Mucha-Habermann disease was made. Febrile ulceronecrotic Mucha-Habermann disease is a rare and severe variant of PLEVA characterised by high fever and papulonecrotic skin lesions. Twenty-five cases have been previously reported. We present the clinical and histological findings in this unusual clinical presentation. [source] Psoriasis under the microscopeJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 2006BJ Cribier Abstract Histopathology is a major diagnostic tool in dermatology, particularly in psoriasiform diseases. Morphological studies showed that the initial event in psoriatic lesions is perivascular infiltrate, followed by dilatation of superficial papillary vessels. Proliferation of keratinocytes and neutrophil exocytosis are secondary events. Fully developed psoriasis has a very characteristic pattern, which includes elongation of rete ridges leading to regular acanthosis, oedema of the papillary dermis associated with tortuous dilated vessels, thinning of suprapapillar area, decreased thickness of granular layer, and exocytosis of neutrophils in the spinous layer (Kogoj's pustule) or in the cornified parakeratotic layer (Munro microabscesses). Pustular psoriasis is characterized by large or confluent intra-epidermal multilocular pustules. Whatever the clinical variant of psoriasis, common morphological signs suggest that it is basically a unique pathological process, with many possible presentations according to various factors such as age, size and localization of lesions, or therapy. Similar microscopic elementary lesions indicate that Hallopeau's acrodermatitis continua, Reiter's disease and geographical tongue are variants of psoriasis. Because of the many faces of the disease, psoriasis can resemble many other squamous or pustular disorders. Differential diagnosis by microscopic analysis is based on pattern analysis, PAS (Periodic Acid Schiff) staining to rule out fungal infection, and immunohistochemistry to characterize lymphocytic infiltrate. Psoriasis is one of the most common inflammatory skin diseases. In its characteristic presentation, psoriasis comprises well-circumscribed red scaly papules and plaques. In this form, the disease is generally easy to identify, especially when the elbows, knees and scalp are affected. Nevertheless, the term ,psoriasis' includes more clinical variants than any other inflammatory dermatosis: psoriasis vulgaris vs. pustular, localized vs. generalized, topographic variants, mucous membranes involvement, hair and nail lesions. Although some of these conditions might be extremely different from psoriasis vulgaris, common pathological findings can be identified in all of them. Microscopic analysis of psoriatic lesions may therefore help clinicians to make the diagnosis and to understand that, whatever the clinical presentation, signs and symptoms are mainly due to a unique pathological process. [source] Localization of sphingomyelin during the development of dorsal and tail epidermis of miceBRITISH JOURNAL OF DERMATOLOGY, Issue 5 2001Y. Yoshida Background The water permeability barrier of the stratum corneum seems to be regulated primarily by lamellar bodies situated between the corneocytes; the lamellar bodies originate largely from polar lipid precursors, mainly sphingomyelin (SM), provided by the cells of the stratum granulosum via exocytosis of their lamellar body content. Objectives The aim of our study was to evaluate the cellular distribution of SM during development of the epidermis. Methods In this study, we investigated the expression and localization of SM in both adult and fetal mouse skin by a cytochemical detection method, immunofluorescence microscopy and immunoelectron microscopy, using anti-SM antibody, a specific binding protein to SM (lysenin), and Nile red stain. In addition, we measured transepidermal water loss to estimate the barrier function of the fetal skin. Results We observed that SM was widely distributed from the basal layer to the granular layer in the adult mouse epidermis. An intense cytochemical reaction for SM was observed on embryonic day E14·5 of gestation just before the differentiation of the granular and squamous cells from the intermediate cells. The immunofluorescence indicating SM was detected in two regions, i.e. the most superficial zone of the granular layer and the upper spinous layer after the cell differentiation at the late gestational age. This distribution was not detected by conventional lipid staining, such as with Nile red stain. Immunoelectron microscopy revealed that SM was mainly localized in the intercellular spaces of the adult mouse epidermis and in the intracellular vesicles without a complete lamellar structure in the cytoplasm of epidermal cells of E14·5 fetuses. It is well known that the formation of the structurally mature cornified cell envelope occurs at E15·5 of development. The skin of fetuses at E16·5 showed a definite barrier function. Conclusions These findings suggest that SM dynamics is related to the formation of the lipid envelope, cell differentiation, and epidermal barrier function during development. [source] Identity of TUNEL-positive cells in the oral buccal epithelium of normal mucosa and lichen lesionsJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 5 2004Andreas Karatsaidis Background:,In situ detection of DNA fragmentation by TdT (terminal deoxynucleotidyl transferase)-mediated dUTP nick end labeling (TUNEL) is a widely used technique to identify apoptotic cells in the terminal phases of cell death. Several studies have shown that there are statistically increased numbers of TUNEL+ cells within the epithelium of oral lichen (OL). It was suggested that this indicates an increased rate of apoptosis among basal and suprabasal keratinocytes in OL epithelium. The aim of this study was to identify the TUNEL+ cells in the epithelium of erythematous (ERY) OL and normal oral mucosa (NOM). Methods:, Sections of biopsies from NOM and ERY OL were processed for TUNEL combined with immunostaining for pan-cytokeratin or for cell markers specifically expressed by different leukocytes. Results:, In NOM, TUNEL+ keratinocytes were almost exclusively seen in the outermost epithelial layers. This labeling was absent in ERY OL. In the basal and lower spinous layers, more TUNEL+ cell nuclei were seen in ERY OL as compared with NOM, in accordance with previous studies. The present observations show, however, that only very few of these cells were keratinocytes, but rather were CD4+ lymphocytes and CD68+ macrophages. There was no difference between the numbers of TUNEL+ keratinocytes in basal and lower spinous layers in ERY OL and NOM epithelium. No intraepithelial CD8+ lymphocytes, Langerhans cells, or mast cells were found to be TUNEL+. Conclusion:, The findings indicate that the pathologic changes in ERY OL epithelium cannot be explained by increased prevalence of terminal keratinocyte cell death identified by TUNEL. [source] Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epitheliaJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2006S. Hatakeyama Background and Objective:, The gingival epithelium is the physiologically important interface between the bacterially colonized gingival sulcus and periodontal soft and mineralized connective tissues, requiring protection from exposure to bacteria and their products. However, of the three epithelia comprising the gingival epithelium, the junctional epithelium has much wider intercellular spaces than the sulcular epithelium and oral gingival epithelium. Hence, the aim of the present study was to characterize the cell adhesion structure in the junctional epithelium compared with the other two epithelia. Material and Methods:, Gingival epithelia excised at therapeutic flap surgery from patients with periodontitis were examined for expression of adhesion molecules by immunofluorescence. Results:, In the oral gingival epithelium and sulcular epithelium, but not in the junctional epithelium, desmoglein 1 and 2 in cell,cell contact sites were more abundant in the upper than the suprabasal layers. E-cadherin, the main transmembranous molecule of adherens junctions, was present in spinous layers of the oral gingival epithelium and sulcular epithelium, but was scarce in the junctional epithelium. In contrast, desmoglein 3 and P-cadherin were present in all layers of the junctional epithelium as well as the oral gingival epithelium and sulcular epithelium. Connexin 43 was clearly localized to spinous layers of the oral gingival epithelium, sulcular epithelium and parts of the junctional epithelium. Claudin-1 and occludin were expressed in the cell membranes of a few superficial layers of the oral gingival epithelium. Conclusion:, These findings indicated that the junctional epithelium contains only a few desmosomes, composed of only desmoglein 3; adherens junctions are probably absent because of defective E-cadherin. Thus, the anchoring junctions connecting junctional epithelium cells are lax, causing widened intercellular spaces. In contrast, the oral gingival epithelium, which has a few tight junctions, functions as a barrier. [source] Expression of human ,-defensins-1 and -2 peptides in unresolved chronic periodontitisJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2004Qian Lu Background:, Human ,-defensins (hBDs) are antimicrobial peptides which contribute to host innate immunity by disrupting the membrane integrity of a broad spectrum of microorganisms. Objectives:, This study aimed to determine the expression profiles of hBD-1 and -2 peptides in gingiva and to assess the possible relations of these antimicrobial peptides with periodontal health and disease. Methods:, Seven periodontally healthy subjects and 22 patients with unresolved chronic periodontitis were recruited and the gingival biopsies collected consisted of healthy tissues from the healthy subjects (HT-C); periodontal pocket tissues (PoT) and inflamed connective tissues (ICT) from the base of pocket, i.e. granulation tissues, as well as clinically healthy tissues (HT-P) from the adjacent clinically healthy sites from the patients. The expression of hBD-1 and -2 peptides was detected by immunohistochemistry and quantitatively analyzed with a computerized image processing system. Results:, Both hBD-1 and -2 peptides were detected in all periodontally healthy subjects, while hBD-1 was detected in all patients and hBD-2 was found in most of the patients. Their expression was mainly confined to the granular and spinous layers of gingival epithelium, in which hBD-1 was detected in both intercellular spaces and cytoplasm, whereas hBD-2 was mainly observed in the cytoplasm. HT-C expressed significantly higher levels of hBD-2 than HT-P (p < 0.05). Within the patients, both defensins were up-regulated significantly in PoT as compared with the adjacent HT-P (p < 0.05). Conclusions:, The present study showed that hBD-1 and -2 were frequently expressed in the granular and spinous layers of gingival epithelia and their expression may be associated with periodontal health and disease. [source] | ||||||||||