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J Brasch

Publications and source records attributed to J Brasch.

At least 19 recordsLinked to original sources
PubMed1992

The effect of selected human steroid hormones upon the growth of dermatophytes with different adaptation to man.

The inhibitory effect exerted by steroid hormones on the in vitro growth characteristics of dermatophytes is poorly understood. As a hypothesis this inhibition could result from fungal adaptation to the human host. Therefore, in this study the susceptibility of representative anthropophilic, zoophilic and geophilic dermatophytes to hormonal inhibition was compared. As a result, in agar dilution assays progesterone, testosterone, and estradiol proved to reduce fungal growth, whereas hydrocortisone had no such effect. In general, anthropophilic dermatophytes were shown to be more responsive to steroid hormones than geophilic species, suggesting a correlation of steroid susceptibility with adaptation to human skin. However, since fungal response to hormones consisted of growth inhibition and occurred only at steroid concentrations much higher than present in human skin, it cannot be assumed to contribute to this adaptation.

Adaptation, Biological↗
PubMed1992

Common pathogenetic pathways in allergic and irritant contact dermatitis.

Despite their different pathogeneses, allergic and irritant contact dermatitis show a remarkable similarity with respect to clinical appearance, histology, and immunohistology. To further analyze this apparent contradiction, our study was designed to meticulously compare cellular infiltrates in irritant and allergic patch-test reactions by immunostaining with a broad panel of monoclonal antibodies. For this purpose, skin biopsies from allergic and irritant patch-test reactions of similar inflammatory degree were obtained from the same probands. We found that after 72 h both types of reaction were characterized by an identical dermal infiltrate consisting mainly of memory T cells, many of which were activated, and macrophages. Dermal and epidermal Langerhans cell density and HLA--DR expression of keratinocytes were also virtually identical. Our results show that antigen recognition by specific memory T cells as well as irritants can finally induce the same pattern of inflammation, including activation of T cells obviously independent of exogenous antigen.

Adult↗
PubMed1992

Infiltrating neutrophils differ from circulating neutrophils when stimulated with C5a, NAP-1/IL-8, LTB4 and FMLP.

In this study we report on functional characteristics of pustule as well as blood polymorphonuclear neutrophils (PMN) in a patient suffering from relapsing bullous staphyloderma. Large numbers of viable PMN from newly formed pustules as well as from the peripheral blood were investigated. During the course of disease chemotactic migration, enzyme degranulation, superoxide-anion generation and leukotriene B4 production were determined simultaneously. The results revealed C5a- and NAP-1/IL-8-specific dysfunction of pustule PMN as compared with blood PMN. In contrast, FMLP-elicited functional activities of pustule PMN were only slightly affected. Our findings provide evidence that in inflamed tissue invading PMN are regulated by in situ generated mediators. C5a produced by staph, aureus-induced activation of the alternative pathway of the complement cascade represents a predominant regulatory factor in situ. Furthermore, the results substantiate previous observations concerning different modulation of C5a and f-met-peptide receptors on human PMN.

Chemotaxis, Leukocyte↗
PubMed1992

Allergic contact dermatitis from chironomids.

Although Type I allergy to chironomids is well-known, allergic contact dermatitis caused by these cosmopolitan insects has not previously been reported. In the case we describe in this report, patch tests disclosed a delayed-type hypersensitivity to 4 different species of chironomids (larvae of Chironomus thummi, Chironomus plumosus, and 2 different species of Glyptotendipes) as the probable cause of airborne facial contact dermatitis. An additional asymptomatic immediate-type allergy to chironomids was demonstrated by scratch tests and specific IgE. The possible sources of exposure to chironomids, their allergens and their distribution are discussed with regard to clinical implications.

Animals↗
PubMed1992

Expression of adhesion molecules in early allergic patch test reactions.

In order to study the relevance of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and endothelial leukocyte adhesion molecule 1 (ELAM-1) for lymphocyte extravasation in the early phase of allergic contact dermatitis, the time courses of lymphocyte infiltration and adhesion molecule expression during initiation of this disorder were determined. Sequential biopsies of positive allergic patch test reactions were obtained 4, 8, 16 and 24 h after antigen application, cryostat sectioned and stained with monoclonal antibodies for ICAM-1, VCAM-1, ELAM-1 and lymphocytes by use of an immunoperoxidase technique. The slides were evaluated semiquantitatively according to appropriate gradation scales that had been defined separately for the staining with each antibody. Our results show that there is a significant upregulation of VCAM-1 and ELAM-1 expression within the first 8 h after antigen application, when lymphocyte extravasation is just beginning. In contrast, ICAM-1 is already expressed in higher levels in normal skin and is hardly enhanced during the first 8 h of patch test reactions. The main influx of lymphocytes occurs 16-24 h after antigen application and is accompanied by a further increase in all three adhesion molecules. We conclude that VCAM-1 and ELAM-1 rather than ICAM-1 may be of particular importance for the start phase of allergic contact dermatitis and that all three of them contribute to an amplification of this inflammation.

Cell Adhesion Molecules↗
PubMed1992

Immunophenotypical characterization of inflammatory cellular infiltrates in tinea.

In order to elucidate the still poorly understood pathogenetic pathways of acute tinea, the inflammatory cellular infiltrates in this infection were analyzed. Lesional punch biopsies were cryostat-sectioned and stained with monoclonal antibodies for immunophenotypization of T cells, B cells, macrophages and activation markers. For each antibody the positively stained inflammatory cells in the dermis and in the epidermis were quantified separately. Most of the dermal mononuclear cells in acute tinea were identified as T helper lymphocytes of the memory type. Furthermore, considerable amounts of Langerhans' cells and macrophages were found, but virtually no B cells. A high proportion of cells expressed markers of activation. Within the epidermis, accumulations of Langerhans' cells and LeuM5+ dendritic macrophages were detected near fungal element. In view of the otherwise rather similar cellular infiltrates in acute tinea and different non-infectious dermatoses, acute tinea may be particularly suitable to study the functional relationship of Langerhans cells and LeuM5+ macrophages.

Acute Disease↗
PubMed1992

Candida albicans grown in glucose-free media contains serum-independent chemotactic activity.

Infection of skin with Candida albicans is usually followed by infiltration of neutrophil granulocytes (PMN). So far, chemotaxins for PMN have been isolated from C. albicans cultures grown in the presence of glucose. However, since glucose is not present in skin in vivo, a contribution of such factors to Candida-triggered cutaneous inflammation would appear unlikely. In order to clarify this question, chemotactic activity was measured in extracts from three different strains of C. albicans which were grown in five different peptone media free of carbohydrates and serum. In addition, four culture systems were supplemented with lipids normally present in human stratum corneum, including a triglyceride, cholesterol, and sphingomyelin. In all sugar-free grown cultures, serum-independent chemotactic activity was detected by use of the Boyden chamber technique. Since, as shown here in vitro, production of neutrophil chemotaxins by C. albicans is independent of glucose-feeding, a possible role of Candida-chemotaxins in the pathophysiology of cutaneous candidosis can no longer be excluded.

Candida albicans↗
PubMed1992

Relapsing bullous staphyloderma.

Relapsing eruptions of bullae rapidly turning into pustules were seen in a 69-year-old woman of good general health. At different times during several months of observation, strains of S. aureus were grown from various lesions, including one (phage group III) producing enterotoxin C. Systemic involvement except for high BSR was absent and repeated blood cultures were negative. Histopathological findings resembled impetigo. Antibiotic treatment was effective. As this disease does not fit into any of the well-known pustular infectious dermatoses, we suggest calling it relapsing bullous staphyloderma.

Aged↗
PubMed1991

Cell trafficking in positive and negative patch-test reactions: demonstration of a stereotypic migration pathway.

The cellular and molecular events taking place during epidermal antigen exposure in sensitized individuals are principally well understood. Epidermal Langerhans cells (LC) are supposed to take up, process, and express a given foreign substance on their cell surface. The antigen is then recognized by T cells bearing the appropriate T-cell receptor (TCR). Because LC do not bear variable antigen (Ag)-specific binding sites, one could postulate that the epidermal exposure of any substance should activate LC and other cells of the skin immune system. To test this hypothesis, we analyzed immunophenotypically the cellular trafficking events in positive (n = 5) and negative epicutaneous patch-test reactions (n = 10), using a panel of monoclonal antibodies against CD1a, CD11c (Ki-M1, LeuM5), CD68 (Ki-M6), Ki-M8, and CD3 (Leu4). We can demonstrate that irrespective of whether or not an antigen will be responded to by the immune system (i.e., positive or negative test reaction), epidermal antigen exposure causes a decrease of LC density in the epidermis and simultaneously causes an increase of LC in the dermis. Moreover, monocytes and T cells immigrate into the dermis both in positive and negative patch-test reactions. As is to be expected, the degree of this cellular traffic is more pronounced in positive test reactions, which may be due to amplification mechanisms caused by antigen recognition of sensitized T cells. This finding demonstrates that human skin contains cell migration programs that ensure that any foreign substance will be accessible to the skin immune and phagocytic system.

Antibodies, Monoclonal↗
PubMed1991

Allergic contact dermatitis from 4-chloro-7-nitrobenzofurazan.

A 30-year-old pharmacist suffered from acute allergic contact dermatitis due to 4-chloro-7-nitrobenzofurazan (NBD-Cl). Contact allergy towards this reagent and 2 of its reaction products was proven by patch tests. As NBD-Cl has not been reported as an allergen before, the characteristics of this chemical and its use as an analytical reagent are briefly surveyed. Similarities to dinitrochlorobenzene (DNCB) are pointed out.

Acute Disease↗
PubMed1991

[The enzyme release by Trichophyton rubrum is dependent on nutritional substance supply].

Enzymes liberated by growing dermatophytes are of pathogenetic importance in tinea. To investigate the influence of nutrients on this enzyme release, Trichophyton rubrum was grown in media containing peptone, keratin and lipids, to which glucose was added in separate assays. The culture supernatants were compared for extracellular enzyme activities by use of the api-zym-test. Our results clearly show that the extracellular enzyme activity is dependent on the nutrients supplied. Seven different enzymes were released when keratin was supplied, as compared to only 5 and 2, respectively, when lipids or peptone were available. Among these enzymes alkaline phosphatase and N-acetyl-beta-glucosaminidase were detected in all cultures lacking glucose. Enzyme release was inhibited completely when glucose was added to the media, except for N-acetyl-beta-glucosaminidase in peptone cultures. This dependency of enzyme release on fungal nutrition can be expected to occur in vivo, too. In addition, it has to be considered for in vitro cultural conditions. Alkaline phosphatase and acetyl-glucosaminidase may be more important in tinea than has been assumed so far.

Culture Media↗
PubMed1991

[Periorbicular trichophyton verrucosum infections].

Three patients with periorbicular infections by Trichophyton verrucosum are described. This type of fungal infection is much less common as compared to the usual kerion formation. The main characteristics of Trichophyton verrucosum and of the epidemiology and clinical course of infections with Trichophyton verrucosum are summarized. In this condition the identification of the causative agent as well as the therapeutic regimen chosen to eliminate fungal growth deserve careful attention.

Adolescent↗
PubMed1990

Dominance of memory over naive T cells in contact dermatitis is due to differential tissue immigration.

CD4+ T cells include a naive (CD4-, CD45RO-, CD29-, CD45RA+) as well as a memory subpopulation (CD4+, CD45RO+, CD29+, CD45RA-). These subpopulations represent different stages in T-cell development and function. Recently, it has been shown that inflammatory and neoplastic CD4+ T-cell infiltrates are dominated by the memory subpopulation, whereas both subpopulations are about the same size in the peripheral blood. This was thought to be the result of in situ maturation of naive into memory T cells. We analysed early positive patch-test reactions 1-2 days after antigen challenge and found that most of the CD4+ T cells that had freshly immigrated into the tissue carried the memory phenotype. Their preferential migration may be mediated by at least five adhesion molecules expressed on their cell surface. This observation has important pathogenetic implications, since memory T cells can be rapidly activated by antigens and secrete a wide variety of pro-inflammatory cytokines.

Antigens, CD↗
PubMed1990

[Pathogens and pathogenesis of dermatophytoses].

The principles of taxonomic and systematic classification of dermatophytes are described with an emphasis on the relevance of teleomorphic forms. Special attention is given to their relation to dimorphic fungi and the formation of arthroconidia as a parasitic growth form. The main factors contributing to pathogenicity of dermatophytes are explained, including enzymes (especially keratinases), allergens and leukotaxins. Genetic predisposition and the unspecific (serum factors, polymorphoneutrophilic granulocytes) and specific immunological mechanisms of host defence are differentiated and critically evaluated.

Arthrodermataceae↗