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Biomedical subjects

A Scheynius

Publications and source records attributed to A Scheynius.

At least 145 records · Page 8Linked to original sources
PubMed1986

Effects on murine T helper cell proliferation by DTH activated syngeneic epidermal cells.

Epidermal cells, obtained either from the site of a delayed type of hypersensitivity (DTH) reaction to 2,4-dinitro-1-fluorobenzene (DNFB) or from skin subjected only to painting with acetone: olive oil have been studied for their capacity to stimulate antigen specific T-lymphocyte proliferation. Small numbers of cells from the control, as well as from the DTH activated epidermis, presented collagen type II to a line of and a clone of collagen II specific T helper cells. Larger numbers of epidermal cells from DTH activated epidermis suppressed this T-cell proliferation compared to control epidermal cells. Phenotypic analysis showed an increased expression of Thy-1 antigen on epidermal cells from DTH lesions 3 days after provocation. It is suggested that epidermal cells may be involved in negative as well as positive feedback loops in conjunction with T-cell immunity. It would thus be of interest to study further whether the induced Thy-1 antigen expression on epidermal cells is of importance in a negative feedback system.

Animals↗
PubMed1985

Class II transplantation antigens in the late human skin tuberculin reaction.

The presence of class II transplantation antigens on keratinocytes and the phenotypes of the inflammatory cells in the late human skin tuberculin reaction were analysed with immunohistochemical double staining techniques in frozen sections of skin biopsies taken 10-45 days after intradermal purified protein derivative (PPD) injection. Dermal cell infiltrates decreased with time but were found throughout the observation period. Most of the cells in the perivascular infiltrates expressed HLA-DR antigens. Some of these cells are probably 'activated' macrophages, since they expressed OKM1 and OKT9 antigens in consecutive sections. Another less frequent cell population which reacted with RFD1 antibodies are presumably interdigitating cells. About half the perivascular cells were anti-Leu 3a-positive (T 'helper/inducer' phenotype). HLA-DR but not HLA-DQ antigens were detected on keratinocytes. This acquired expression of HLA-DR antigens on the epithelial cells disappeared between 17 and 30 days. If HLA-DR-expressing keratinocytes have immunoregulatory functions these might be different from those of other HLA-DR-expressing cell types that also express HLA-DQ molecules.

Epidermal Cells↗
PubMed1985

Treatment of therapy-resistant Sézary syndrome with Cyclosporin-A: suppression of pruritus, leukaemic T cell activation markers and tumour mass.

A patient with Sézary's syndrome resistant to conventional therapy was successfully treated with Cyclosporin-A (CyA) for 14 months. Pre-treatment in vitro studies showed that the leukaemic T cells were sensitive to therapeutic concentrations of CyA. The patient's pruritus disappeared promptly after 2 d of treatment. The positive effect of CyA on the pruritus was related to the dose and plasma concentrations of the drug. Analysis of leukaemic cell surface markers using monoclonal antibodies showed that episodes of pruritus were correlated with the appearance of cells expressing the T cell "activation" markers interferon- gamma (IFN-gamma) and HLA-DR. This indicated that CyA may control pruritus by suppressing the production/release of lymphokines. Immunohistochemical staining of repeated skin biopsies demonstrated a reduction of infiltrating T cells. Clinically, this was correlated with an improved skin status and a partial regress of palpable lymph node size. Apart from an initial reversible drop in the circulating helper/suppressor T cell ratio, the number of circulating Sézary cells was unaltered during CyA treatment. After 5 months, higher doses of CyA were needed to control symptoms, and this was correlated wit with partial drug resistance also in vitro.

Aged↗
PubMed1984

Human keratinocytes express HLA-DR antigens in the tuberculin reaction.

The cellular response in the human skin tuberculin reaction was studied with immunohistochemical double-staining techniques in frozen sections of skin biopsies taken 6 h to 8 days after intradermal PPD injections. Cell infiltrates were observed from day 2 onwards and increased in size up to 4 days. Most of the infiltrating cells reacted with anti-Leu 3a (T 'helper/inducer' phenotype) antibodies. In contrast to normal epidermis, not only Langerhans cells but also keratinocytes expressed HLA-DR antigens from day 4 onwards. The induction of HLA-DR antigens on keratinocytes may be secondary to T-cell activation. Since the HLA-DR expression on keratinocytes appeared late in the tuberculin reaction, the function may be to suppress rather than enhance the immune response.

Adult↗
PubMed1984

Phenotypic characterization in situ of inflammatory cells in pityriasis (tinea) versicolor.

The cellular response in pityriasis (tinea) versicolor lesions was analysed in situ with an immunohistochemical double staining technique combined with periodic acid-Schiff staining in frozen sections of skin biopsies from 9 patients. The proportions of B and T cells and subpopulations of T cells in the blood were normal as were the proliferative responses of blood mononuclear cells against various B- and T-cell mitogens and antigens. Fungi were observed in stratum corneum in all lesions, and there were moderate cell infiltrates in both epidermis and dermis as compared to biopsies from normal-looking skin. The majority of the infiltrating perivascular cells reacted with anti-Leu 1 antibodies (all mature peripheral T cells). Anti-Leu 2a reactive cells ('suppressor/cytotoxic' phenotype) were few and scattered, whereas anti-Leu 3a reactive cells ('helper/inducer' phenotype) dominated. This investigation demonstrates that pityriasis versicolor is not a simple overgrowth of the fungus in stratum corneum, but is accompanied by infiltrating immunocompetent cells in both epidermis and dermis.

Adult↗
PubMed1984

Phenotypic characterization in situ of inflammatory cells in allergic and irritant contact dermatitis in man.

The cellular response in allergic and irritant contact dermatitis was analysed in situ with an immunohistochemical double staining technique. Allergic patch test reactions were elicited in 10 patients and irritant reactions in eight cases, using the Finn chamber technique. Skin biopsies were obtained 6-72 h after test applications. Frozen sections of 43 biopsies were investigated by simultaneous staining with rabbit anti-HLA-DR antibodies and various mouse monoclonal antibodies. The cell infiltrates were usually larger in the allergic than in the irritant reactions. However, the kinetics of the cell responses, the phenotypes of the inflammatory cells, their distribution and spatial relationships were similar. It thus appears that the applications of allergens or irritants to the skin generates a cell pattern that to a large extent reflects an immunological readiness for further immune reactions.

Adult↗
PubMed1983

Epidermal Langerhans cells as accessory cells in con A stimulation of T lymphocytes in the guinea-pig.

Stimulation of guinea-pig T cells by concanavalin A (Con A) requires Ia-antigen expressing accessory cells. Such functional accessory cells were identified among the normal epidermal cells and could be fractionated and enriched by centrifugation on discontinuous Percoll density gradients. Epidermal cells collecting at a density of 1.08 g/ml were the most effective in mediating Con A-dependent T cell proliferation, induced the highest activity of T cell growth factors (TCGF) and were enriched fivefold for Ia antigen expressing cells. A monolayer immunosorbent technique yielded a 35-fold enrichment of Ia antigen expressing epidermal cells. This cell fraction induced high levels of TCGF in the culture supernatants. Since the only cells in the normal epidermis expressing Ia antigens are the Langerhans cells, we conclude that the Langerhans cells may act as accessory cells for Con A stimulation of T cells.

Animals↗
PubMed1983

Dermatitis herpetiformis: relation between circulating antibodies against reticulin and gluten, small-intestinal mucosal status and absorptive capacity.

The status of the jejunal mucosa and of the intestinal absorptive capacity were investigated and related to the occurrence of antibodies against reticulin and gluten in 55 patients with dermatitis herpetiformis (DH), 28 on a normal, 11 on a gluten-reduced and 16 on a gluten-free diet. The mucosal status was characterized on the basis of histopathological findings and the numbers of intra-epithelial lymphocytes. Absorption was evaluated by 5-h urine and 1-h serum D-xylose tests. There was a positive correlation between the degree of pathological mucosal changes, malabsorption and the occurrence of circulating antibodies against reticulin and gluten. The serum xylose test was more sensitive than the urine xylose test for screening of the relatively mild enteropathy of DH and identified 88% of the patients with an abnormal mucosal status. The serological test (antibodies to reticulin and gluten) identified 80% of such patients. Among patients on a gluten-free diet there was some discrepancy between the serum xylose and the serological test, in that 5 of the 16 patients on this diet had an abnormal serum xylose test result, but no antibodies. In DH patients on a normal diet, the presence of antibodies to reticulin and gluten provided the same information about the presence of mucosal lesions as the serum xylose test. In the whole material a combination of the serum xylose test and the serological test identified 24 of 25 patients with an abnormal mucosal status.

Adult↗
PubMed1983

Gluten-free diet in patients with dermatitis herpetiformis. Effect on the occurrence of antibodies to reticulin and gluten.

In a prospective study of 51 patients with dermatitis herpetiformis (DH), the occurrence of antibodies against reticulin and gluten was investigated and the influences of gluten-free, gluten-restricted, and normal diets on the persistence of these antibodies were compared. After a period extending from 11 to 47 months, none of the patients who were eating a gluten-free diet had reticulin or gluten antibodies. The patients eating a normal diet had the same incidence of reticulin autoantibodies at the end of the study as at its beginning, and gluten antibodies developed in some additional patients during the follow-up period. Thus, we have shown that the elimination of gluten from the diet of patients with DH has an important influence on the occurrence of antibodies to both reticulin and gluten.

Adult↗
PubMed1982

Evidence in support of a self-perpetuating HLA-DR-dependent delayed-type cell reaction in rheumatoid arthritis.

Originating from observations on similarities between the rheumatoid synovial tissue and skin lesions in delayed-type hypersensitivity reactions--similarities as to massive infiltrates of "helper" T lymphocytes close to HLA-DR-expressing macrophage/dendritic cells--a notion is formed on the importance of local macrophage-dependent helper T-cell activation in the rheumatoid joint similar to that in a delayed-type skin reaction. In vitro studies on suspended synovial cells have been used to test and qualify these ideas. It is shown that (i) HLA-DR-expressing cells in normal synovial intima can, like epidermal Langerhans cells, mediate T-cell activation; (ii) the large numbers of rheumatoid synovial HLA-DR-expressing macrophage-like/dendritic cells are heterogeneous and mediate either efficient activation or suppression of T-lymphocyte proliferation, and (iii) specificity of rheumatoid T cells can be analyzed with the help of autologous synovial antigen-presenting cells; a specific anti-collagen type II response is reported in three patients.

Arthritis, Rheumatoid↗
PubMed1982

Antigenic similarities and differences in genus Pityrosporum.

Using the indirect immunofluorescence technique no differences were observed in intensity of staining when antisera against Pityrosporum orbiculare and P. ovale or IgG fractions of these were incubated with P. orbiculare and P. ovale cells. However, a weaker reaction was observed with these antisera and P. pachydermatis cells. With IgG fractions the nonspecific fluorescence was minimized. Fungal cells in biopsies from tinea versicolor lesions showed a brilliant staining with the IgG fractions of antisera against P. orbiculare. This investigation indicates a close antigenic relationship between all of the 3 Pityrosporum species. A common antigenicity was found between P. orbiculare and P. ovale cells as well as between P. orbiculare cells from culture and the fungal cells in biopsies from tinea versicolor lesions. This strongly suggests that these 2 species are identical with each other and with the organism found in tissue.

Animals↗
PubMed1982

Enrichment of epidermal Langerhans cells: studies with a monolayer technique and flow cytometry sorting.

Langerhans cells were enriched from epidermal cell suspensions by a monolayer technique based on the association of Langerhans cells with solid matrix-bound anti-Ia antibodies or by flow cytometry sorting of fluorescein-isothiocyanate labeled anti-Ia reactive cells. The monolayer technique gave a moderate enrichment (15-37%) whereas considerably higher purity (73-87%) was obtained by flow cytometry sorting. The identity of the enriched anti-Ia reactive cells as Langerhans cells was established by histochemical techniques or electron microscopy. The monolayer-enriched Langerhans cells could function as stimulating cells in the mixed leukocyte culture reaction and as antigen-presenting cells.

Animals↗
PubMed1982

In situ identification of T lymphocyte subsets and HLA-DR expressing cells in the human skin tuberculin reaction.

T lymphocyte subsets and HLA-DR expressing cells were studied with an immunohistochemical double staining technique in frozen sections of human skin 6, 48 and 96 hr after intradermal PPD injections. The number of lymphocytes reacting with monoclonal Leu 1 antibodies (all mature peripheral T cells) increased with time. The majority of the T lymphocytes at 48 and 96 hr reacted with Leu 3a ('helper/inducer' phenotype) antibodies and a few with Leu 2a ('suppressor/cytotoxic' phenotype) antibodies. Apposition of T lymphocytes of both subsets to HLA-DR expressing cells occurred in the dermis as well as in the epidermis. The study gives a morphological picture of the cell-mediated immune reactions in delayed type of hypersensitivity consistent with in vitro experiments on proliferative responses to soluble antigens.

Adult↗
PubMed1981

Anti-Ia-reactive cells in mycosis fungoides: a study of skin biopsies, single epidermal cells and circulating T lymphocytes.

Skin sections, epidermal cells in suspension and circulating T lymphocytes were investigated for the presence of Ia-like antigens in a group of patients with the cutaneous T-cell lymphoma mycosis fungoides (MF) and in healthy controls. Highly purified anti-Ia antibodies were used in indirect immunofluorescence, indirect peroxidase and peroxidase-antiperoxidase techniques. Allogeneic and autologous mixed leukocyte reaction tests with epidermal cells from MF lesions as stimulator cells were also performed. The majority of the dermal lympho-histiocytes and mononuclear cells in the epidermal Pautrier microabscesses expressed Ia-like antigens. So also did a greater proportion of circulating T lymphocytes than in the controls. In some MF patients a high percentage of single epidermal cells of non-lymphoid character also reacted with the antibodies. The possible significance of the present findings for the pathogenesis of MF is discussed.

Adult↗
PubMed1980

Methenamine-hippurate and bacteriuria in the geriatric patient with a catheter.

Oral treatment with methenamine-hippurate (MH) in patients with an indwelling catheter has been found to reduce the need of frequent catheter exchange and the number of symptomatic infections. Bacteriuria, however, persists during MH treatment. The hypothesis that the therapeutic effect is due to a reduction in the number of bacteria, or a change in the pattern of strains was tested in a crossover study (2 x 6 weeks). MH treatment, 1 g twice daily, was compared to control periods in 52 patients. The majority of quantitative and qualitative bacterial cultures at 2-week intervals yielded 2--4 strains. Of the bacterial isolates, 50% were found on 4--6 occasions out of 6 possible. MH treatment had no significant influence on the pattern of various strains. A 30% decrease in the mean total bacterial count during MH treatment did not reach statistical significance (p approximately 0.07). It is suggested that prevention of catheter complications during MH treatment may be due to a physiochemical action on salt formation rather than a direct antibacterial effect.

Aged↗