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Biomedical subjects

D N Sauder

Publications and source records attributed to D N Sauder.

At least 91 records · Page 5Linked to original sources
PubMed1994

Lymphocyte function-associated antigen-1 is required for maximum elicitation of allergic contact dermatitis.

Cell adhesion molecules (CAMs) are known to play an important role in cell-mediated immunity and inflammation. To investigate the importance of one of the CAMs, lymphocyte function-associated antigen-1 (LFA-1) in allergic contact dermatitis (ACD), a specific anti-LFA-1 monoclonal antibody was injected into the ears of mice after sensitization but prior to challenge with dinitrofluorobenzene (DNFB). BALB/c mice were sensitized on the dorsal skin with DNFB, and challenged on the ears 6 days later. The effect of the antibody on the elicitation phase of contact sensitization was determined by its intradermal injection into the pinnae of the mice at doses of 1-40 micrograms. At 24 and 48 h after challenge, ear swelling was dose-dependently suppressed by injection of LFA-1 antibody at doses of 2-40 micrograms, which are less than 10% of the systemic dose required for effective suppression of delayed-type hypersensitivity in previous studies. Maximal inhibition of ear swelling (44%) was observed after injection of 20 micrograms of anti-LFA-1 antibody. Inhibition of ear swelling was accompanied by a reduction in dermal oedema and leucocyte infiltration into the dermis. Our results suggest that LFA-1 plays a significant role in the elicitation of ACD reactions, and also that our test system is a sensitive and useful means of evaluating the blocking effect of antibody to adhesion molecules thought to be involved in the elicitation phase of ACD.

Animals↗
PubMed1994

Differential modulation of interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) in human epidermal keratinocytes by UVB.

Conflicting reports exist concerning ultraviolet-B (UVB) effects on keratinocyte (KC) interleukin-1 (IL-1) expression. To clarify the modulatory effects of UVB on IL-1, the following study was undertaken. Normal human epidermal KCs cultured in a standard low Ca2+ and serum-free medium were irradiated in quiescent phase with UVB. In this study, we used semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the mRNA level of interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta). After exposure to 100 or 300 J/m2 UVB, a transient increase in mRNA levels was observed within 1 hour for IL-1 alpha and 3 to 6 h for IL-1 beta. Following this transient induction, mRNA levels for both IL-1 alpha and IL-1 beta returned to steady-state levels after 100 J/m2. After 300 J/m2 irradiation, IL-1 alpha and IL-1 beta levels were downregulated compared to unirradiated cultures at 24-h post-irradiation. The half-life for IL-1 alpha and IL-1 beta was estimated using actinomycin D treatment. Both IL-1 alpha and IL-1 beta mRNAs half-lives (t1/2) decreased faster in irradiated cells (t1/2 = 30 minutes for IL-1 alpha and 2 h for IL-1 beta) compared to unirradiated cells (t1/2 = 1 h and 4 h, respectively). These results suggest that IL-1 alpha and IL-1 beta mRNA expression are differentially regulated by UVB. In contrast to down-regulation of mRNA levels, a significant increase in IL-1 alpha protein levels, measured by ELISA, was observed in culture supernatants from 6 h to 24 h after 300 J/m2 UVB irradiation. Cycloheximide treatment did not abrogate this increase in IL-1 alpha protein level. Since this dose of UVB irradiation decreased the stability of IL-1 alpha and IL-1 beta mRNA, this suggests that the release of IL-1 alpha after UVB irradiation was due to leakage from UVB-damaged cells and not from de novo protein synthesis.

Cells, Cultured↗
PubMed1994

Characterization of epidermal cytokine profiles in sensitization and elicitation phases of allergic contact dermatitis as well as irritant contact dermatitis in mouse skin.

Epidermal cytokines are known to participate in the initiation of immune and inflammatory processes in the skin. In the present study, we examined epidermal cytokine mRNA levels to elucidate the initial molecular events in the sensitization and elicitation phases of allergic contact dermatitis (ACD) as well as in irritant contact dermatitis (ICD). BALB/c mice were sensitized on the dorsal skin with 0.5% dinitrofluorobenzene (DNFB) and challenged with 0.2% DNFB on the ears 6 days later to elicit allergic contact hypersensitivity (ACDe), the elicitation phase. To examine cytokine profiles during the sensitization phase from the same anatomic area, other animals were sensitized on ear instead of dorsal skin. The sensitization phase of ACD (ACDs) was induced by painting the ears of naive mice with 0.5% DNFB. Sodium lauryl sulfate (SLS), utilized as an irritant control, was also applied to the ears of another group of mice to induce ICD. Total RNA was extracted from the epidermis of the treated ears at various time points after each treatment, reverse transcribed to cDNA, and amplified by PCR using radiolabeled cytokine-specific primers. Amplified products were sized by electrophoresis and autoradiography and semiquantitated by densitometry. Autoradiographs were normalized relative to beta-actin signals. ACDs and ACDe showed similar patterns of cytokine mRNA levels; that is, at 6 h after hapten application, interleukin (IL)-1 beta, IL-6, IL-10, and granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA levels were upregulated, and this upregulation was observed until 24 h after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effect of ultraviolet-inducible cytokines on melanoma growth in vivo: stimulation of melanoma growth by interleukin-1 and -6.

Ultraviolet light of wavelengths 280-320 nm (UVB) can induce transcription of cytokine mRNAs and increase expression of the corresponding proteins in the epidermis. In particular, UVB can stimulate keratinocyte synthesis of interleukin-1 (IL-1), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta). Several of these cytokines can influence the growth of tumour cells as well as the host response to these tumours. In this study we examined the effect of IL-1, IL-6, IL-8, TNF-alpha and TGF-beta on the growth of melanoma in vivo and in vitro, using the murine B16 melanoma and its syngeneic host, the C57BL/6 mouse. Mice were injected with 0.1-1.5 micrograms of recombinant cytokine subcutaneously every other day following a subcutaneous injection of 1 x 10(5) B16 cells (F-10 clone). In this model, tumours appeared within 12-14 days, and IL-1 and IL-6 stimulated tumour growth in vivo. TNF-alpha, TGF-beta, IL-2 and IL-8 had no significant effect. In contrast to the in vivo effects, TNF-alpha inhibited B16 cell growth in vitro and IL-6 stimulated B16 cell growth. The in vivo IL-1 effect on tumour growth in mice was examined in greater detail. IL-1-treated animals showed tumours approximately 5-fold greater in size than those of the control animals. The IL-1-treated animals also showed highly vascularized tumours that invaded underlying muscle tissue more rapidly than controls. These tumors also showed a strong positive reaction with antibody to intercellular adhesion molecule-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effects of a novel topical immunomodulator, imiquimod, on keratinocyte cytokine gene expression.

A novel immunomodulator, imiquimod, has been shown to be an effective topical antiviral and antitumor agent in animal models. Imiquimod has been reported to induce interferon-alpha and other cytokines in animals and humans, but its precise role as an immunomodulator at skin sites has not been determined. We investigated its effect on cytokine gene expression in the human epidermal carcinoma cell line COLO-16 and human keratinocytes. COLO-16 cells were incubated with imiquimod (1 and 10 micrograms/ml) and human keratinocytes with 5 micrograms/ml for 6 or 24 h. Cytokine gene expression was analyzed by reverse-transcriptase PCR. In COLO-16 cells, imiquimod stimulated IL-6 mRNA levels 2.3- and 4.4-fold at 1 and 10 micrograms/ml after 6 h. IL-8 mRNA increased 4-fold at both 1 and 10 micrograms/ml. At 24 h, though IL-6 mRNA level at 1 micrograms/ml was further stimulated, enhanced expressions of IL-8 at 1 micrograms/ml and both IL-6 and IL-8 at 10 micrograms/ml were down-regulated. In human keratinocytes, 5 micrograms/ml of imiquimod stimulated IL-6 mRNA levels 1.4-fold at 6 h and 2.1-fold at 24 h, and IL-8 mRNA levels 1.7- and 2.0-fold at 6 and 24 h. IL-1 alpha mRNA levels in COLO-16 or keratinocytes were unchanged by either dose or incubation time. These results suggest that stimulation of IL-6 and IL-8 expression may be involved in the immunomodulating action of imiquimod.

Adjuvants, Immunologic↗
PubMed1994

Antifungal agents: an overview. Part I.

The last decade has witnessed remarkable advances in the therapy for cutaneous fungal diseases. These will have a major impact on the choice of antifungal therapy. To understand these advances traditional therapies for fungal diseases, the polyenes, griseofulvin, older topical agents and the older azoles, will be reviewed first. Part II will focus on recent advances.

Administration, Cutaneous↗
PubMed1994

Interleukin-8 immunoreactivity in epidermis of cutaneous T-cell lymphoma patients.

The histopathologic hallmark of cutaneous T-cell lymphoma is collections of malignant T cells in the epidermis. The mechanism(s) involved in the T-cell localization is unknown, however recent evidence suggests that cytokines play a role. Since Interleukin-8 functions both as a leukocyte and lymphocyte chemoattractant, we measured IL-8 expression in skin of cutaneous T-cell lymphoma patients. Lesional skin was obtained by biopsy from cutaneous T-cell lymphoma (CTCL) patients and patients suffering from other dermatoses and subjected to in situ hybridization with a 35S-Riboprobe and immunofluorescence to detect IL-8. Fourteen out of 15 lesional biopsies from histologically proven CTCL patients displayed intense epidermal IL-8 immunoreactivity compared to negligible reactivity in sections from 14 normal patients and other inflammatory dermatoses. These results were corroborated by strong hybridization signals using IL-8 probes in only the lesional CTCL skin. Lesional CTCL epidermis contains elevated levels of IL-8 mRNA and protein suggesting a role for this cytokine in the pathogenesis of the disease.

Antibodies, Monoclonal↗
PubMed1993

Epidermal cytokines in murine lupus.

Murine lupus and the analogous human disease systemic lupus erythematosus (SLE) in humans are characterized by multisystem disease accompanied by the production of numerous serum autoantibodies. The classic model of murine lupus is the New Zealand black mouse (NZB). In this strain anti-DNA antibodies are the most specific marker for the presence of murine lupus, in that this autoantibody parallels both the development and activity of the disease. Exposure to ultraviolet (UV) radiation is known to exacerbate the disease in both the murine and the human disease. UV irradiation of the skin increases serum levels of certain cytokines including interleukin-1 (IL-1), IL-6, and granulocyte/macrophage-colony stimulating factor (GM-CSF), which can influence B- and T-cell function. Recent studies have focused on the role of cytokines in SLE. We hypothesize that the ultraviolet (UV)-induced exacerbation in NZB mice in part is mediated by UV-induced cytokines such as IL-1. Eight-week-old female NZB and DBA/2 mice were exposed to UV irradiation. Sera and supernatants from spleen cell cultures were assayed for anti-DNA antibodies. After UV exposure, NZB mice showed a marked increase in such antibodies. Skin from both strains of mice was probed for IL-1 alpha mRNA before and after UV irradiation. At 24 h, DBA/2 mice had a slight increase in mRNA coding for IL-1 alpha, whereas a much greater increase in skin IL-1 alpha was seen in the NZB skin. This increase in IL-1 mRNA was associated with similar increases in IL-1 bioactivity. These data suggest that the mechanism underlying the UV-induced exacerbation of lupus is mediated in part by the cutaneous production of IL-1.

Animals↗
PubMed1993

IL-8 gene expression and production in human keratinocytes and their modulation by UVB.

Interleukin (IL)-8 is a member of the supergene family of proinflammatory and chemotactic cytokines recently termed chemokines. IL-8 has been implicated in the pathogenesis of inflammatory skin diseases such as psoriasis. In this study, IL-8 mRNA expression and protein production were determined in normal cultured human epidermal keratinocytes after ultraviolet-B (UVB) irradiation. Messenger RNA levels were determined by the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Total RNA was extracted from cultured keratinocytes at various time points post-irradiation, reverse transcribed to cDNA, and amplified by PCR using a labeled specific primer for the target gene. Amplified products were sized by electrophoresis, visualized by autoradiography, and quantitated by densitometry. Autoradiographs were normalized relative to glyceraldehyde-3-phosphate-dehydrogenase (G3PDH) signals. Constitutive expression of IL-8 mRNA was seen in normal cultured keratinocytes. After 100 or 300 J/m2 UVB irradiation, a rapid increase in IL-8 mRNA level was observed within 1 h after irradiation. At 24 h after irradiation, the mRNA level was elevated 11-13 times compared with the control level. Production of IL-8 protein in culture supernatants was assayed by enzyme-linked immunosorbent assay (ELISA). Significant levels of IL-8 protein were observed at 24 h after irradiation. Cycloheximide treatment blocked this IL-8 protein induction. As IL-8 is known to be an inflammatory cell chemotactic factor, these results suggest a possible role for IL-8 in UVB-induced skin inflammation and diseases.

Cells, Cultured↗
PubMed1992

Identification and characterization of a partial cDNA expressing interleukin-1-like activity in keratinocytes.

A partial cDNA has been isolated from the human keratinocyte cell line COLO-16 which is distinct from either IL-1 alpha or beta and encodes a protein which displays some of the biological properties associated with IL-1. The 720 bp partial cDNA hybridized on Northern blots of COLO-16 mRNA to a 1.6 kbp message of low abundance. Expression of the partial cDNA in COS-1 cells resulted in activity in three IL-1 assays: thymocyte co-stimulation, D10.G4.1 T-cell stimulation and fibroblast proliferation. Antisera generated against synthetic peptides based on inferred protein sequence from the cDNA reacted with a 20 kDa and 30 kDa species in both the COLO-16 cell line and PMA-stimulated normal human keratinocytes. These novel species were also present in PMA-stimulated and unstimulated human dermal fibroblasts and human T-cell lines.

Amino Acid Sequence↗
PubMed1992

Combined treatment with oral etretinate and electron beam therapy in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome).

BACKGROUND: Total skin irradiation for early-stage mycosis fungoides produces clinical remission in 90% of patients, but the median duration of remission is only 2 to 4 years. Etretinate has proven efficacy in advanced mycosis fungoides. Its potential as adjuvant therapy to radiation could be limited by toxicity from the combination. OBJECTIVE: Our purpose was to determine whether oral etretinate at 1 mg/kg can be combined with 35 Gy of radiation without intensifying or prolonging the radiation reaction and to determine the relapse-free survival rate. METHODS: Twenty-three patients began etretinate on day one of radiation and the dose was reduced for nose bleeds, dry skin, or hyperlipidemia. During the reaction skin toxicity questionnaires were completed weekly. Nine concurrent patients receiving only radiation completed identical forms. RESULTS: Etretinate did not intensify the skin reaction but did prolong it by 2 weeks. At a median follow-up of 2 years the relapse-free survival rate in complete responders was similar to stage-matched concurrent and historic control subjects. CONCLUSIONS: Both radiation and etretinate can be given together with acceptable toxicity and without compromising either therapy.

Administration, Oral↗
PubMed1992

Inhibition of interleukin-1 beta mRNA expression and interleukin-1 alpha and beta secretion by a specific human recombinant interleukin-1 receptor antagonist in human peripheral blood mononuclear cells.

The transcription and translation of interleukin-1 (IL-1) may have a pleiotropic effect on the immune system and inflammatory diseases. Recently it has been reported that human monocytes not only produce IL-1 but also induce, with adherent IgG, the secretion of an IL-1 receptor antagonist (IL-1Ra), which can play an essential in vivo and in vitro role in the regulation of IL-1 activity. Recombinant human (rh) IL-1Ra is structurally similar to IL-1 beta but with no IL-1-like activity, and specifically binds to the IL-1 receptor. To more fully evaluate and clarify the inhibitory effect of rhIL-1 receptor antagonist on IL-1 we have studied the influence of rhIL-1Ra on IL-1 transcription and translation. In this report we show that IL-1 beta mRNA from peripheral blood mononuclear cells (PBMC) is strongly inhibited (66%) when rhIL-1Ra (250 ng/ml) was added to cultured cells activated with lipopolysaccharide (LPS) (100 ng/ml) for 4 hr, determined with the slot blot analysis. The addition of exogenous rhIL-1 beta to the cell culture diminished the inhibitory effect (44%). Moreover, we report that the block of IL-1 mRNA transcription consequently leads to the inhibition of IL-1 alpha and IL-1 beta secretion in human PBMC, as measured by ELISA method. In fact, herein we show that LPS activates human PBMC to secrete IL-1 beta and IL-1 alpha, an effect inhibited, in a dose-dependent fashion by rhIL-1Ra (0.025-250 ng/ml) in an overnight incubation. Since IL-1 is a strong inducer of IL-1 synthesis in vivo and in vitro, in our study we used rh IL-1 alpha to stimulate the secretion of IL-1 beta in human PBMC. This activation, carried out overnight, also provoked the release of IL-1 beta in a dose-dependent manner, which was strongly inhibited by rhIL-1Ra used at different concentrations (0.025-250 ng/ml). The inhibitory effect exerted by IL-1Ra on human PBMC IL-1 mRNA transcription and the down-regulation of secretion of IL-1 beta stimulated by IL-1 alpha, may contribute to therapeutic effects in inflammatory diseases such as rheumatoid arthritis and other autoimmune diseases.(ABSTRACT TRUNCATED AT 400 WORDS)

Cells, Cultured↗
PubMed1992

Keratinocyte cytokines.

It is now clear that keratinocytes produce a wide range of cytokines that can be regarded as important mediators of intercellular communication. A major emphasis has been placed on IL-1 because of its relationships with other cytokines and other differentiated tissues. Dysregulation of IL-1, IL-1 receptor, and inhibitory factors for IL-1 may cause imbalance of skin biology, leading to perpetuation of immune and inflammatory events. Interaction of IL-1 with other cytokines in vivo is also important in the understanding of the pathophysiology of skin diseases. More fundamental questions regarding the homeostatic significance of IL-1 in keratinocytes still remain to be answered.

Colony-Stimulating Factors↗
PubMed1991

Langerhans cell histiocytosis in monozygotic twins.

Langerhans cells histiocytosis, one of a group of histiocytosis syndromes characterized by Langerhans cell infiltration, has many clinical manifestations. In the past 30 years, numerous cases of presumed Letterer-Siwe disease, the acute multiorgan variant, have been reported in twins and siblings. Only recently has the Histiocyte Society established a criterion for a "definitive diagnosis" of Langerhans cell histiocytosis--the presence of Birbeck granules within the cells of the histiocytic infiltrate. We report the fatal outcome of Langerhans cell histiocytosis in monozygotic twin infants. There is no satisfactory explanation why Langerhans cell histiocytosis occurs concurrently in twins. We suggest that cytokines may provide an endogenous signal that triggers the pathologic proliferation of Langerhans cells.

Diseases in Twins↗
PubMed1991

Polymyositis: a manifestation of chronic graft-versus-host disease.

Polymyositis developed in a patient who had had bone marrow transplants for the treatment of acute myeloid leukemia. There was no previous evidence of graft-versus-host disease. Polymyositis has previously been reported to be associated with graft-versus-host disease; this article suggests that polymyositis may represent its sole manifestation.

Adult↗