Biomedical subjects

W Diezel

Publications and source records attributed to W Diezel.

At least 19 recordsLinked to original sources

PubMed1996

Histochemical, immunohistochemical and ultrastructural studies on the action of glucocorticoids on epidermal Langerhans cells (ELC) of murine skin.

We studied the influence of the glucocorticosteroids dexamethasone and prednisolone on epidermal Langerhans cells (ELC) in the ear skin of BALB/c mice. ELC were detected by HLA II-antigen-expression and ATPase staining. The number of ELC was counted by normal light and immunofluorescence microscopy. Both, dexamethasone and prednisolone decreased the number of ELC and the intensity of the reaction for HLA II and ATPase significantly. In the electron microscope, ELC were identified by their light cytoplasm, the lobulated nucleus and typical Birbeck Granula (BG). After systemic application of dexamethasone or prednisolone the ultrastructure was changed with respect to a loss of typical BG and occurrence of numerous small vacuoles without electron dense content instead of BG.

Animals↗

PubMed1995

Inhibition of eicosanoid formation in human polymorphonuclear leukocytes by high concentrations of magnesium ions.

The cutaneous antiinflammatory action of Dead-Sea brine is thought to be due to magnesium ions. To elucidate their mode of action, we studied the influence of isotonic solutions containing high concentrations of Mg2+ (up to 115mM) on the formation of 5-lipoxygenase-derived eicosanoids in human polymorphonuclear leukocytes. The cells were stimulated by either ionophore A23187 or the chemotactic peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine. We observed a pronounced inhibition of the formation of leukotriene B4 and 5-hydroxyeicosatetraenoic acid from either added [1-14C] or endogenously liberated arachidonic acid. In the latter case, the sum of arachidonic acid and its oxygenation products was also markedly diminished. The inhibitory effects of Mg2+ depended in a reciprocal manner on the concentration of Ca2+ in the incubation medium. An unspecific damage to cells as reason for the inhibitory effects was excluded. Human recombinant 5-lipoxygenase was also inhibited by Mg2+ in the same concentration range (IC50 16 mM). These data suggest that high concentrations of Mg2+ inhibit the eicosanoid metabolism both at the level of the liberation of arachidonic acid and by direct inhibition of the 5-lipoxygenase enzyme.

Arachidonate 5-Lipoxygenase↗

PubMed1994

Inhibitory effects of sulfonated shale oils (ammonium bituminosulphonates, Ichthyols) on enzymes of polyenoic fatty acid metabolism.

The two commercial pharmaceutical preparations of ammonium bituminosulphonates, Leukichthol and Dark Ichthyol, were shown to inhibit the formation of 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) from external arachidonic acid by human polymorphonuclear leukocytes stimulated by ionophore A-23187 in a dose-dependent manner. Pure arachidonate 15-lipoxygenases from rabbit reticulocytes and soya beans, and the particulate prostaglandin endoperoxide synthase from sheep vesicular glands, were also inhibited. With the reticulocyte lipoxygenase, the Ichthyols suppressed the enzyme activity by two different mechanisms: (1) a prolongation of the lag period typical of lipoxygenase catalysis, and (2) by a lowering of the maximal enzymatic activity after the end of lag period. As expected, the first effect was reversed by the addition of the lipoxygenase product 13S-hydroperoxy-9Z,11E-octadecadienoic acid (13-HpODE). Ammonium bituminosulphonates are thus universal inhibitors of lipoxygenase activities, and the latter are of potential importance in inflammatory dermatoses.

Arachidonic Acid↗

PubMed1993

The effect of splenopentin (DA SP-5) on in vitro myelopoiesis and on AZT-induced bone marrow toxicity.

Splenopentin (DA SP-5) is a pentapeptide corresponding to the amino acid sequence 32-36 (Arg-Lys-Glu-Val-Tyr) of the splenic hormone splenin. We examined the influence of DA SP-5 on bone marrow progenitor cell (BMC) proliferation. DA SP-5 acts as a co-stimulant for recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) in the induction of human BMC derived colony formation in vitro (colony-forming units). When exposed to DA SP-5 and thereafter to AZT and rHuGM-CSF, BMCs show a colony-forming response similar to that after cultivation with the rHuGM-CSF alone. In contrast, when exposed to AZT and rHuGM-CSF (and not preincubated with DA SP-5) the colony formation was reduced. A similar pentapeptide thymopentin (Arg-Lys-Asp-Val-Tyr) did not influence colony formation by human BMCs. We assume that DA SP-5 could support therapeutic effects of rHuGM-CSF.

Amino Acid Sequence↗

PubMed1993

Efficacy of tromantadine and aciclovir in the topical treatment of recurrent herpes orofacialis. Comparison in a clinical trial.

In a double-blind study, 198 patients experiencing recurrent herpes orofacialis were randomly assigned to treatment with either tromantadine hydrochloride (ViruMerz Serol, CAS 53783-83-8) or aciclovir. All patients performed an up to 5-day course of topical treatment beginning on average within 2 h after the first signs of recurrence. The herpes efflorescences and symptoms were assessed daily by the same physician for 14 days, except on weekends, and by the patients each day during the whole observation time. Rapid healing was achieved with both medications. Efficacy was assessed by rating the course of vesicle eruptions, duration until beginning of incrustation and the clinical course of the symptoms (burning, tension, pain). Equivalence between the medication groups was shown by comparative analysis of all evaluation criteria. The global efficacy and tolerability of both medications was rated by the physician as well as by the patients as "good" or "very good" in more than 80% of the cases. The results of this trial show equivalence of both medications in the treatment of recurrent herpes orofacialis, and confirm the good dermal tolerability of the drugs.

Acyclovir↗

PubMed1992

Inhibition of skin allograft rejection and acute graft-versus-host disease by cis-urocanic acid.

Ultraviolet B radiation initiates a suppression of the delayed-type hypersensitivity response accompanied by a generation of antigen-specific suppressor cells and an alteration of antigen-presenting function. In previous studies we and other investigators could achieve a prolongation of graft survival by a treatment of the recipient with UVB light or 8-methoxy-psoralen plus UVA light (PUVA). One of the mediators of the systemic immunomodulatory effects of ultraviolet light or PUVA may be urocanic acid, which is isomerized in the skin by ultraviolet light from its cis- to the trans-isomer. In this work we present evidence that cis-urocanic acid, generated in vitro by a treatment with UVB light or PUVA, is able to prolong the survival of allogeneic MHC disparate skin grafts in mice. In contrast, the rejection of second set grafts was not suppressed. Unirradiated (trans-urocanic acid) had no effect on allograft rejection. In a murine model cis-, but not trans-urocanic acid, prevented or delayed an acute lethal graft-versus-host disease. These experiments demonstrate the potent systemic immunomodulatory effects of cis-urocanic acid in vivo.

Animals↗

PubMed1992

[ATPase positive epidermal Langerhans cells: inhibition of ATPase by ammonium bituminosulfonate (Ichthyol) and pix lithanthracis].

Both, ammonium bituminosulfonate (Ichthyol) and Pix lithanthracis reduce the number of ATPase-positive epidermal Langerhans cells (ELC) in the epidermis of BALB/c mice: vaselinum flavum alone vs vaselinum flavum +5% Ichthyol: P less than 0.01; vaselinum flavum vs vaselinum flavum +5% Pix lithanthracis: P less than 0.001. In contrast to this, the number of Ia-positive cells was not changed under identical conditions. These results allow the conclusion that Ichthyol and Pix lianthracis are able to inhibit the enzyme ATPase on the surface of ELC. We infer that inhibition of ELC ATPase may be important in the regulation of ELC function (inhibition of cutaneous contact hypersensitivity).

Adenosine Triphosphatases↗

PubMed1992

[Ammonium bituminosulfonate (Ichthyol). Anti-inflammatory effect and inhibition of the 5-lipoxygenase enzyme].

Ammonium bituminosulphonate (Ichthyol) inhibits 5-lipoxygenase activity in human polymorphonuclear neutrophils. The inhibition is dose-dependent and occurs at non-cytotoxic concentrations of the drug. This results in a decreased release of Leukotriene B4 from polymorphonuclear neutrophils. Furthermore, when applied to the ear skin of AB/Bln mice pretreated with croton oil, Ichthyol reduces the inflammatory reaction.

Animals↗

PubMed1992

[In vitro proliferation of human bone marrow cells--inhibition by components of Candida albicans].

Candida albicans (CA) components influence the proliferation of human bone marrow cells in vitro (colony-forming assay). Number of colonies per 10(5) bone marrow cells after cultivation with rHuGM-CSF (maximal plateau colony formation): 46.2 +/- 9.1 (n = 6); after cultivation with rHuGM-CSF in combination with CA proteins: 0.05 mg protein/ml: 33.4 +/- 4.6 (n = 3); 0.10 mg protein/ml: 20.8 +/- 3.6 (n = 3).

Bone Marrow Cells↗

PubMed1991

Inhibition of Langerhans cell ATPase and contact sensitization by lanthanides--role of T-suppressor cells.

Lanthanides are rare earths, elements 55-71 in the periodic table, that are of interest in biologic systems as isomorphic competitors for calcium binding sites. Lanthanides were tested for their inhibitory influence on the Ca++/Mg(++)-dependent ATPase of epidermal langerhans cells in vitro, and on the immunologic function of Langerhans cells in vivo. The trivalent ions of lanthanides, lanthanum, and cerium completely inhibited the ATPase staining of Langerhans cells in vitro. When mice were sensitized with dinitrofluorobenzene on skin sites pretreated with topical lanthanum chloride, and challenged on untreated ear skin, a markedly reduced contact hypersensitivity response was observed. This hyporesponsiveness was found to be antigen specific, and could be passively transferred to naive syngeneic animals recipients by CD4-CD8+ spleen cells. These results suggest that inhibition of the epidermal Langerhans cell surface ATPase by application of topical lanthanum and the induction of antigen-specific immunologic tolerance may be related events.

Adenosine Triphosphatases↗

PubMed1990

Cytofluorometric and cytomorphologic analysis of human bone marrow cells derived from stromal cultures stimulated by granulocyte-macrophage colony-stimulating factor, interferon-gamma and splenopentin pentapeptide.

We studied the influence of human recombinant granulocyte-macrophage colony-stimulating factor (hrGM-CSF), human recombinant interferon-gamma (hrIFN-gamma) and splenopentin pentapeptide (Sp-5), either alone or in combination, on the proliferation and differentiation of human bone marrow cells in modified Dexter's cultures. After 10, 14 and 21 days cells were analyzed by classical staining according to Pappenheim and by cytofluorometry with a set of different monoclonal antibodies. IFN-gamma inhibited the proliferation of progenitor cells and provided signals promoting monocytic differentiation, whereas GM-CSF induced the proliferation of blastoid elements which expressed HLA-DR and M2 (VIM-2 monoclonal antibody), but progressively lost surface CD34. Furthermore, an increase of CD15+ cells was also observed. When GM-CSF was tested in combination with IFN-gamma, it abolished the inhibitory effect of IFN-gamma and both cytokines synergized to promote the expression of CD11c, CD14 and M2 surface antigens. Sp-5 alone had only a marginal activity, but it potentiated the effects of GM-CSF. These findings suggest that GM-CSF may induce the transition from stem cells to committed myeloid progenitors. In contrast to IFN-gamma, Sp-5 can serve as an additional proliferative signal with negligible effects on cell maturation.

Amino Acid Sequence↗

PubMed1990

Inhibition of rat heart allograft rejection by a PUVA treatment of the graft recipient. Role of cisurocanic acid.

Treatment of rat heart grafts with PUVA, the combination of the photosensitizer 8-methoxypsoralen and longwave ultraviolet light, leads to a prolonged transplant survival in allogeneic recipients. A PUVA treatment of the recipient rats, performed for 7 consecutive days after transplantation, prolonged graft survival even more effectively. This may be due to the systemic immunomodulatory effects of PUVA in the recipient. One of the mediators is urocanic acid, which is transformed by ultraviolet light in the skin from its trans- to the cis-isomer, which, in turn, acts as a mediator on the immune system. An injection of cisurocanic acid into graft recipients for 7 consecutive days after transplantation resulted in prolonged graft survival; in 40% of the rats, permanent graft acceptance was observed. The significance of these results for clinical organ transplantation is discussed.

Analysis of Variance↗

PubMed1990

Stimulation of the recruitment of epidermal Langerhans cells by splenopentin.

Splenopentin (SP-5: Arg-Lys-Glu-Val-Tyr), a pentapeptide corresponding to the residues 32-36 of the splenic hormone splenin, increases dose-dependently the number of bone marrow colonies (M and GM colonies). Therefore, we tested the stimulatory effect of SP-5 on the recruitment of epidermal Langerhans cells in skin deprived of these cells. A high dose of cyclophosphamide or dexamethasone led to a drastic decrease of LC density in murine skin with slow and incomplete restoration. SP-5 accelerated Langerhans cell recruitment and led to pretreatment levels of Langerhans cell density in the skin. These results indicate that SP-5 may possibly be used to treat disorders (e.g., HIV infection) where impaired Langerhans cell density and function can lead to secondary cutaneous infections.

Animals↗

PubMed1990

Splenopentin (DAc-SP-5) accelerates the restoration of myelopoietic and immune systems after sublethal radiation in mice.

In 1981 a new splenic hormone was described by Audhya et al. (Biochemistry, 20, 6195-6200, 1981). At first designated as thymopoietin III, the complete amino acid sequence had been described as splenin in 1984. For the pentapeptide corresponding to amino acids 32-36 of splenin was shown to be active in immunological systems. The synthetic pentapeptide splenopentin (DAc-SP-5) and the sequence 32-36 of splenin are identical. In this study the recovery of immunocompetence in mice following sublethal irradiation is shown to be enhanced by DAc-SP-5. The treatment effects of DAc-SP-5 were verified by splenic plaque-forming response to a T-cell dependent antigen and in the hematopoietic colony-forming assay. These effects were associated with an accelerated recovery of leukocyte counts in peripheral blood and spleen without significant changes in the relation between leukocyte and lymphocyte subpopulations. Furthermore, in comparison to control animals DAc-SP-5 treated mice showed in the first weeks postexposure a significantly higher number of bone marrow derived cells as well as granulocyte-macrophage and macrophage colony-forming cells (GM-CFC and M-CFC). Therefore, DAc-SP-5 may be a useful substance for treating secondary forms of bone marrow depression.

Animals↗

PubMed1990

Splenopentin (DAc-SP5)--influence on engraftment and graft-vs-host reaction after non-H-2 bone marrow transplantation in mice.

The influence of DAc-SP5 on engraftment and graft-vs-host reaction (GVHR) was studied in different non-H-2 strain combinations. The engraftment was more or less enhanced in every case, whereas the situation in the GVHR was completely different. In one case splenopentin did not influence the course of the GVHR so much, in a second case the symptoms of the GVHR were completely abolished, and in a third case the GVHR was dramatically enhanced up to a great mortality. Therefore, before application of DAc-SP5 to the bone marrow transplantation in humans in order to improve the engraftment, parameters have to be found which allow an exact prediction about the influence of splenopentin on the GVHR in each single case.

Animals↗

PubMed1990

[The effect of Tomesa therapy on epidermal Langerhans cells in experimental animals].

In the last years a new therapy of psoriasis was developed, which consists in a treatment with salt solutions, resembling the water of the Dead Sea, and ultraviolet light (Tomesa-therapy). We studied the influence of the used salt on ATPase positive epidermal Langerhans cells in murine ear skin. An irreversible partial reduction of the Langerhans cell ATPase was found after salt treatment of separated epidermis or of full skin preparations. These results may have implications for the optimization and broader application of this therapy.

Adenosine Triphosphatases↗

PubMed1990

[Inflammation-inhibiting effect of magnesium ions in contact eczema reactions].

Water containing high concentrations of magnesium ions (e.g. Dead Sea water) is effective in the treatment of inflammatory skin diseases. Therefore, we examined the influence of Mg2+ on inflammation in allergic contact dermatitis induced by 1-chloro-2,4-dinitrobenzene (DNCB) in BALB/c mice. Animals challenged with 0.125% DNCB in the presence of magnesium chloride (28% and 14%) demonstrated significantly less pronounced contact dermatitis (ear swelling) than did animals challenged with DNCB alone (p less than 0.001 and p less than 0.01). In mice challenged with DNCB in combination with sodium chloride (14%) there was no statistically significant difference in the degree of ear swelling. These results were borne out in 5 patients known to be allergic to nickel, in whom magnesium chloride but not sodium chloride, suppressed nickel sulphate-induced contact dermatitis.

Adolescent↗

PubMed1990

[Prolonging transplant survival time by PUVA treatment of the transplant recipient. Significance of cis-urocanic acid].

A PUVA treatment of the recipients of murine tail skin grafts led to a significant prolongation of transplant survival. A possible mechanism of the systemic immunomodulatory effects of ultraviolet light in the organism is the transformation of urocanic acid in the skin from its trans- to the cis-isomer, which acts as a mediator on the immune system. A treatment of graft recipients with cis-, but not trans-urocanic acid also prolonged graft survival. The rejection of secondary grafts and the humoral immune response of mice to sheep erythrocytes were not influenced by cis-urocanic acid. These results implicate that cis-urocanic acid may be get use in clinical organ transplantation and dermatology.

Animals↗