Ultrastructure of the human mucocutaneous end organ.

The ultrastructure of the human mucocutaneous end organ is described. The corpuscle is divided into sublobular units comprising axon terminals surrounded by generally concentric lamellar processes which are derived from laminar cells whose nuclei are situated towards the periphery of the sublobules. Interlamellar substance which contains elastic tissue, collagen and coarse periodicity crossbanded structures intervenes between lamellar processes. Specialized zones of contact resembling desmosomes are found at intervals seemingly connecting adjacent lamellar processes and axons with lamellar processes. The ultrastructural features of this end organ are similar to that of the Meissner corpuscle despite minor differences of the light microscopical appearance, which supports the view that differences in sensory end organs are merely variations on a common organizational basis.

Surface-bound immunoglobulin E on antigen-presenting cells in cutaneous tissue of atopic dermatitis.

Both type I and type IV hypersensitivity reactions have been implicated in the pathogenesis of atopic dermatitis. Using monoclonal antibodies we have identified IgE on the surface of cutaneous dendritic cells in both lesional and nonlesional skin. Double immunofluorescence labeling demonstrates these cells to be antigen-presenting cells. Immunoglobulin E (IgE) was not identified on such cells either in atopic individuals with no history of dermatitis or in patients with a range of other dermatoses. Further studies are consistent with IgE being bound to the cell surface via an Fc-IgE receptor. We conclude that this finding is specific for atopic dermatitis and thus may provide a link between the two types of hypersensitivity reactions frequently observed.

Monoclonal antibody labeling of mononuclear cell surface antigens in formaldehyde-fixed paraffin-embedded cutaneous tissue.

The influence of the sequential stages of conventional formaldehyde fixation and paraffin embedding of cutaneous tissue on monoclonal antibody labeling of cell surface antigens is described. The effects of variation in fixation time, dehydration, clearing, wax embedding, and enzyme treatment of cutaneous sections were examined. By curtailing fixation time, using cold ethanol dehydration, and limited cold clearing with xylene, immunoreactivity of several important monoclonal antibodies was retained. Wax embedding could be achieved at 58 degrees C for 1 h or by using low-melting-point wax at 42 degrees C for 3 h. Thus was derived an optimal processing procedure which afforded good tissue morphology and allowed reliable reproducible labeling by monoclonal antibodies to cell surface antigens.

The effect of in vivo interferon-gamma on the distribution of LFA-1 and ICAM-1 in normal human skin.

Lymphocyte function associated antigen 1 (LFA-1) and its ligand intercellular adhesion molecule 1 (ICAM-1) are cell surface adhesion molecules important in many lymphocyte-mediated responses. Recent in vitro studies have demonstrated that the cytokine interferon-gamma (IFN-gamma) can induce ICAM-1 expression by keratinocytes, and that lymphocytes adhere to IFN-gamma treated keratinocytes. In view of the importance of keratinocyte/lymphocyte interactions in the pathogenesis of cutaneous disease, we have examined the effects of in vivo IFN-gamma on cutaneous expression of LFA-1 and ICAM-1. Fourteen volunteers received intradermal IFN-gamma (dose: 1 or 10 micrograms) daily for 3 d. Biopsy was obtained on day 6. Cryostat sections were stained by the peroxidase antiperoxidase technique employing murine monoclonal antibodies to CD11, CD18, and ICAM-1. IFN-gamma intensified ICAM-1 expression by dermal endothelial cells and induced keratinocyte expression of ICAM-1. Furthermore, after administration of 10 micrograms of IFN-gamma LFA-1 positive (LFA + ve) lymphocytes were observed along the basement membrane zone closely related to ICAM-1 + ve basal keratinocytes and also surrounding dermal endothelium. Exposure to IFN-gamma induced expression of both CD11a and CD18 antigens on epidermal Langerhans cells. These studies suggest that the distribution of adherence molecules expression within cutaneous tissue in vivo is modulated by IFN-gamma, and that these alterations may be important in interactions involving cutaneous immunocompetent cells.

A technique for immunoultrastructural identification of T6-positive Langerhans cells and indeterminate cells in mycosis fungoides.

An immunoelectron microscopic method was developed using T6 antiserum in an immunoperoxidase technique to label the dendritic cells of the epidermis in mycosis fungoides (MF). The technique allows simultaneous identification of intracellular Birbeck granules and T6 membrane positivity. Ultrastructural examination of the epidermal infiltrate of MF, using this method, confirmed the T6-positive nature of Langerhans cells and indeterminate cells. All Sézariform and mature lymphocytes were T6-negative and a small population of T6-negative histiocytic cells were also observed.

Ultrastructural identification of T lymphocytes in tissue sections of mycosis fungoides.

An immunoelectronomicroscopic method has been employed to demonstrate in situ the T lymphocyte nature of the dermal and epidermal infiltrates to mycosis fungoides. A specific antiserum to the human T lymphocyte surface antigen (HTLA) was used in an indirect reaction with a peroxidase labeled anti-immunoglobulin. After histochemically revealing the peroxidase activity, T cells were easily identified by the deposition of electron dense material on the cytoplasmic membrane. Counterstaining with uranyl acetate and lead citrate enabled us morphologically to observe the maturity of infiltrating T lymphocytes and to identify Sézary cells and other cells such as eosinophils in the infiltrate. Our results confirm the T cell nature of the dermal infiltrate in mycosis fungoides and show that the epidermal infiltrate of cells forming Pautrier micro-abscesses are predominantly T lymphocytes.

Mononuclear leukocyte cyclic adenosine monophosphate responses in psoriasis are normal.

It has been proposed that immune dysfunction in psoriasis is a consequence of aberrant cyclic nucleotide metabolism. We have examined cyclic AMP responses to isoprenaline, histamine, and prostaglandin E2 in peripheral blood mononuclear leukocytes from patients with psoriasis, in the presence and absence of a potent cyclic AMP phosphodiesterase inhibitor. Stimulated and basal cyclic AMP levels in mononuclear leukocytes from psoriatics did not differ from those observed in mononuclear leukocytes from normal subjects, irrespective of the stimulant employed, either in the presence or in the absence of the phosphodiesterase inhibitor. These findings do not support the hypothesis that psoriasis is associated with either impaired beta-adrenergic reactivity or a more generalized abnormality of mononuclear leukocyte cyclic nucleotide metabolism.

Expression of simple epithelial keratins 8 and 18 in epidermal neoplasia.

A systematic study of keratin expression in epidermal lesions (six actinic keratoses, 10 Bowen's disease, seven squamous cell carcinomas) has been undertaken by using a large panel of monospecific monoclonal antibodies to individual keratins. Expression of differentiation-specific keratins was frequently delayed or lost from dysplastic regions. Novel expression of the embryonic, or simple epithelial, keratins 8 and 18 was widely observed in intradermal areas of poorly differentiated squamous cell carcinomas. In addition, the most proliferative of in situ malignancies (Bowen's disease) also contained small numbers of cells expressing simple epithelial keratins. These observations suggest that the expression of simple epithelial keratins may be of functional importance in malignancy of keratinocytes and could be related to tumor invasion and/or to changes in epithelial-mesenchymal interactions.

Exploitation of phylogenetic distance in cell surface immune labeling: studies with beta 2-microglobulin.

Beta 2-microglobulin (beta 2M) is part of the HLA molecule, and is found on the cell surface of human nucleated cells. In certain skin tumors, malignant change has been associated with a loss of this surface beta 2M, indicating a possible diagnostic value for this marker. At present beta 2M is best identified in paraffin-embedded tissue by means of a triple-layer peroxidase-antiperoxidase technique, using mammalian polyclonal antisera. Recently a polyclonal antiserum against human beta 2M has been produced in chickens. Because of the phylogenetic differences between the species, the resulting antiserum is likely to recognize more epitopes on the beta 2M and show greater sensitivity than antisera raised in mammalian species. To confirm this hypothesis, the avian antiserum was compared to both mammalian polyclonal (rabbit) and monoclonal (mouse) antibody in vitro. beta 2M fixed to plastic surfaces combined with more avian than mammalian antibody. Furthermore, insolubilized chicken antibody could bind more secondary antibody-horseradish peroxidase conjugate than could insolubilized mammalian antibody, thus showing even greater enhancement with this system. Immunohistochemical analysis of these systems confirmed that the chicken strategy has greater sensitivity, and can be used in an indirect system with consequent reduction in nonspecific background activity. It is the most suitable technique for the investigation of the distribution of beta 2M in paraffin-embedded tissue.

E-selectin binds to squamous cell carcinoma and keratinocyte cell lines.

E-selectin is an endothelial adhesion molecule that binds carbohydrate epitopes on leukocytes and has been implicated in a potential pathway of tumor metastasis. Keratinocyte cell lines express similar carbohydrate epitopes, one of which, sialyl Lewis X (SL-X) is a ligand for E-selectin and is also expressed by squamous cell carcinomas (SCC) in situ. The functional role of keratinocyte selectin ligands was investigated using a soluble E-selectin chimaeric protein (pE-sel-Ig) containing pig lectin-like and epidermal growth factor-like domains fused to human IgG. After incubation of keratinocyte cell lines (A431 and SVK14) and normal keratinocytes with pE-sel Ig, binding was quantified by flow cytometry. Frozen sections of SCC were overlaid with pE-sel Ig and binding was visualized immunoenzymatically. Immunolabeling was undertaken using monoclonal antibodies (CSLEX-1 and HECA-452), which label E-selectin ligands including sialyl Lewis X. E-selectin bound strongly to A431 and SVK14 cells; the degree of binding paralleled staining intensity with CSLEX-1 antibody. HECA-452 antibody stained A431 cells strongly but SVK14 cells only weakly. Normal keratinocytes and normal epidermis did not express CSLEX-1 or HECA-452 antigens or bind E-selectin. Serial sections of SCC revealed close correlation between fusion protein binding and antibody staining. Antibody pretreatment of tumor sections with CSLEX-1 blocked fusion protein binding, whereas HECA-452 antibody only slightly reduced fusion protein binding. pE-sel Ig pretreated with YT11.1 antibody failed to bind to A431 or SVK14 cells or to SCC. These studies provide functional evidence that SL-X/E-selectin pathways may be important in SCC metastasis and that A431 and SVK14 cells provide a good model to investigate these mechanisms.

Effect of in vivo interleukin-1 on adhesion molecule expression in normal human skin.

We have examined the expression of three endothelial adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], endothelial leukocyte adhesion molecule-1 [ELAM-1], and vascular cell adhesion molecule-1 [VCAM-1]) in normal human skin following intradermal injection of stratum corneum-derived interleukin-1 alpha (SCIL-1 alpha). In control skin, constitutive expression of ICAM-1 was found on endothelial cells and at low levels on dermal dendritic cells but not on keratinocytes. ELAM-1 and VCAM-1 were present in low levels on endothelium and perivascular dendritic cells, respectively. SCIL-1 alpha injection produced marked endothelial ELAM-1 upregulation. Double staining with neutrophil elastase demonstrated that many ELAM-1-positive vessels contained marginating neutrophils and that interstitial neutrophils were clustered around ELAM-1-positive vessels. An increase in dermal dendritic cell ICAM-1 expression occurred and in two of three biopsies there was keratinocyte expression of ICAM-1 in the SCIL-1 alpha-injected tissue. Also, there was upregulation of VCAM-1 on vascular endothelium and an increase in the dermal dendritic cell expression of this molecule. These results give in vivo confirmation that SCIL-1 alpha modulated endothelial and dermal dendritic cell adhesion molecule expression, and show that endothelial VCAM-1 is regulated in vivo by SCIL-1 alpha, thus providing a regulatable ICAM-1-independent means of mononuclear cell recruitment.

Adhesion molecule expression in polymorphic light eruption.

Endothelial leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) are cytokine-regulated cell-surface leukocyte adhesion molecules. We have investigated the in vivo kinetics and pattern of expression of these adhesion molecules in relation to tissue accumulation of leukocytes in the photodermatosis, polymorphic light eruption (PMLE), which is characterized by dense perivascular leukocytic infiltration. Immunohistology was performed on biopsies taken at varying time points from PMLE lesions induced in 11 subjects by suberythemal solar simulated irradiation. Vascular endothelial ELAM-1 expression was first observed at 5 h, maximal at 24 to 72 h, and remained elevated at 6 d. VCAM-1, minimally expressed in control skin, was induced above background levels on endothelium and some perivascular cells after 24 h and maintained at 6 d. Endothelial cell ICAM-1 expression was increased above control levels at 72 h and 6 d. Keratinocyte ICAM-1 expression, most marked overlying areas of dermal leukocytic infiltration, began at 5 h and was strong at 72 h and 6 d. In addition to lymphocytes, significant numbers of neutrophils but not eosinophils were detected in the dermal leukocytic infiltrate that appeared at 5 h and persisted at 6 d. The pattern of adhesion molecule expression that we have observed is similar to that seen in normal skin during a delayed hypersensitivity reaction. These observations support an immunologic basis for PMLE.

Interferon-gamma activates co-ordinate transcription of HLA-DR, DQ, and DP genes in cultured keratinocytes and requires de novo protein synthesis.

The purpose of this study was to determine the effect of interferon-gamma on keratinocyte major histocompatibility complex class II gene transcription. Transformed human foreskin keratinocytes (SVK14 cells) were incubated with recombinant IFN-gamma in the presence or absence of the protein synthesis inhibitor cycloheximide. Total cellular RNA was extracted from the cells and Northern blot analysis carried out using cDNA probes for all the functional class II genes. We report that 1) there is co-ordinate activation of all the class-II genes; 2) the rate of transcription varies between gene loci after activation; and 3) de novo protein synthesis is required for IFN-gamma activation of class II transcription.

Effects of serum albumin, indomethacin and histamine H1-antagonists on Paf-acether-induced inflammatory responses in the skin of experimental animals and man.

Cutaneous responses to synthetic platelet activating factor (Paf-acether) have been studied in guinea-pig and human skin. Intradermal injection of Paf-acether elicited an acute inflammatory response in guinea-pig skin (assessed by means of radioisotopic techniques) and acute oedema formation in human skin (assessed by means of weal volume and flare area). Acute inflammatory responses in guinea-pig and human skin are potentiated by the presence of serum albumin, a phospholipid carrier. Acute inflammatory responses induced by Paf-acether in guinea-pig and human skin are not significantly affected by concomitant administration of the cyclo-oxygenase inhibitor, indomethacin. Acute inflammatory responses induced by Paf-acether in guinea-pig and human skin are not significantly affected by concomitant administration of the cyclo-oxygenase inhibitor, indomethacin. Acute inflammatory responses induced by Paf-acether in guinea-pig and human skin are slightly modified by the H1-receptor antagonists, mepyramine and chlorpheniramine. These results indicate that the acute inflammatory response induced by Paf-acether is independent of cyclo-oxygenase products of arachidonic acid and that histamine release has a minor contribution to the inflammatory response induced by Paf-acether.

Pagetoid reticulosis. Histiocyte marker studies.

Epidermal mononuclear cell infiltrate from three patients with pagetoid reticulosis was examined for the presence of the cytoplasmic markers lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin, using specific antisera and a peroxidase-antiperoxidase technique. Many of the infiltrating cells possessed these markers, indicating that they belonged to the monocyte-macrophage-histiocyte series.

Spontaneous regression of perianal extramammary Paget's disease after partial surgical excision.

A 62-year-old woman presented with a three-year history of a pruritic perianal lesion, which was histologically confirmed to be perianal extramammary Paget's disease. Partial surgical excision of the lesion was followed by complete spontaneous regression of the residual plaque.

Cutaneous periarteritis nodosa. Hepatitis B surface antigen-containing immunocomplexes and polymorphonuclear-leukocyte lysosomal enzyme release.

In a patient with cold-induced cutaneous periarteritis nodosa, cryoprecipitation of a circulating hepatitis B surface antigen-containing immunocomplex resulted in phagocytosis by neutrophils and monocytes with prominent vacuolation of the cells and extracellular release of lysosomal enzymes. We believe this immunocomplex attached itself to the cell membrane and induced vacuolation and degranulation in normal neutrophils.

Loss of membrane B2 microglobulin in eccrine porocarcinoma. Its association with the histopathologic and clinical criteria of malignancy.

A sensitive immunoperoxidase method employs a new chicken anti-B2-microglobulin (B2M) antibody for use on paraffin sections. The method demonstrates the loss of B2M from the cell membranes of malignant eccrine poromas , and this is correlated with the histopathologic and clinical criteria of malignancy.

Sunlight exposure, antioxidant status, and cataract in Hong Kong fishermen.

STUDY OBJECTIVES: The aim was to test whether cataract is associated with higher lifetime exposure to sunlight, and whether antioxidants protect against cataract. DESIGN: This was a cross sectional survey of eye disease, with assessment of antioxidant status in a subgroup. SETTING: Hong Kong fishing communities in 1989. PARTICIPANTS: 685 men and women aged 55 to 74 years old were included in the study, of whom 367 (54%) attended hospital for detailed examination. MEASUREMENTS AND MAIN RESULTS: At a mobile clinic visual acuity and lens opacities were assessed, and using a questionnaire, occupational history and lifetime exposure to sunlight. At hospital ophthalmic measurements were repeated and blood was taken for measurement of plasma vitamin C, vitamin E, and total carotenoids, and red cell activities of glucose-6-phosphate dehydrogenase, glutathione peroxidase, superoxide dismutase, and catalase. Higher grades of cataract (particularly nuclear cataract) tended to be more common in subjects with the most sun exposure, although not to the point of statistical significance. In contrast to earlier studies, no association was found with antioxidant status. CONCLUSIONS: The findings give some support to the hypothesis that sunlight causes cataract. The absence of a relation to antioxidant status may be because blood levels of antioxidants at one point in time do not adequately reflect a subject's past metabolic state, and particularly the past activity of antioxidants in the lens.

Psychiatric services in general hospitals. Rational and irrational considerations.

The structure of a psychiatric service in an urban general hospital is complex. Varied intrainstitutional and extrainstitutional relationships create stress, which can lead to rational and irrational reactions, often in combination. Psychologic mechanisms that exist in individuals also occur as shared defense mechanisms in an institutional setting, serving to reduce anxiety and stress but often at the expense of accurate reality perception. Good communication can play a vital role in reducing reality distortions but is itself often blocked or impaired by the same defense mechanisms that led to the distortions. An awareness of how these mechanisms operate in an institutional setting can aid the psychiatric administrator in correcting distortions and maintaining good channels of communication.