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Biomedical subjects

E Christophers

Publications and source records attributed to E Christophers.

At least 19 recordsLinked to original sources
PubMed1992

Cytokine RANTES released by thrombin-stimulated platelets is a potent attractant for human eosinophils.

Thrombin stimulation of human platelets results in the release of a preformed proteinaceous human eosinophil (Eo)-chemotactic activity. By the use of different high-performance liquid chromatography techniques, two Eo-chemotactic polypeptides (EoCPs), tentatively termed EoCP-1 and EoCP-2, were purified to homogeneity. Upon SDS-PAGE analysis, these chemotaxins showed molecular masses near 8 kD. NH2-terminal amino acid sequence analysis revealed identical sequences for both EoCP-1 and EoCP-2, which are also identical to that of RANTES, a cytokine that structurally belongs to the interleukin 8 superfamily of leukocyte selective attractants, and that is known to be a "memory-type" T lymphocyte-selective attractant. In the major Eo chemotaxin, EoCP-1, the residues 4 and 5, which in EoCP-2 were found to be serine residues, could not be identified. Electrospray mass spectrometry (ESP-MS) of EoCPs revealed for EoCP-2 a molecular mass of 7,862.8 +/- 1.1 daltons, which is 15.8 mass units higher than the calculated value of RANTES, indicating that EoCP-2 is identical to the full-length cytokine, and oxygenation, probably at methionine residue number 64, has taken place. Upon ESP-MS, EoCP-1 showed an average molecular mass of 8,355 +/- 10 daltons, suggesting O-glycosylation at these serine residues. Both natural forms of RANTES showed strong Eo-chemotactic activity (ED50 = 2 nM) with optimal chemotactic migration at concentrations near 10 nM, however, there were no significant migratory responses with human neutrophils. Chemotactic activity of RANTES for human Eos could be confirmed using recombinant material, which has been found to be as active as the natural forms. Since RANTES gene expression has been detected in activated T lymphocytes, and recombinant RANTES was shown to be a "memory" T lymphocyte-selective attractant, it is now tempting to speculate about an important role of RANTES in clinical situations such as allergene-induced late-phase skin reactions in atopic subjects or asthma, where in affected tissues both memory T cells and Eos are characteristic.

Amino Acid Sequence↗
PubMed1992

Mesna side effects which imitate vasculitis.

Mesna (sodium-2-mercaptoethansulfonate) is used in the prophylaxis of cyclophosphamide (CYC)-induced hemorrhagic cystitis. Four patients being treated with "low dose" CYC and prednisone for vasculitis developed severe side effects to Mesna. Fever, arthralgia, myalgia, tachycardia, electrocardiogram changes consistent with perimyocarditis, erythroderma, bullous skin and mucous membrane lesions, and abdominal complaints with profuse diarrhea were noted approximately 3 weeks after the initiation of therapy for CYC-induced leukopenia and a conservatively reduced prednisone dosage. Positive reexposure tests confirmed the association to Mesna use, and hypersensitivity skin tests demonstrated a delayed hypersensitivity reaction.

Adult↗
PubMed1992

Immunohistochemical studies on NAP-1/IL-8 in contact eczema and atopic dermatitis.

The neutrophil activating peptide NAP-1/IL-8 has in the past been shown to be secreted by diverse cell-types involved in inflammatory processes. Furthermore, potent biological effects on both neutrophilic granulocytes and lymphocytes enforce its role in inflammation. Recently, immunohistochemical studies using monoclonal anti-NAP-1/IL-8 antibodies have been performed on dermal inflammatory conditions like psoriasis vulgaris. These have demonstrated epidermal IL-8 immunoreactivity in a pattern inversely related to the degree of inflammatory infiltration. Based on these results, in the present study biopsies from patients with contact eczema as well as atopic dermatitis were examined. The same patterns of immunoreactivity were found with either homogeneous epidermal staining, focally negative staining or overall decreased or even absent staining. As in psoriasis, these patterns were related to the degree of inflammatory infiltration. These results prove NAP-1/IL-8 to be involved not only in psoriasis vulgaris, but more likely to be a marker of different inflammatory processes. Future work will have to examine the kinetics as well as stimuli causing these effect.

Biopsy↗
PubMed1992

Cyclosporine in psoriasis: a multicenter dose-finding study in severe plaque psoriasis. The German Multicenter Study.

Interim results of a randomized, controlled, dose-finding study conducted in 24 dermatology centers on 217 patients with severe chronic plaque psoriasis (entry psoriasis area and severity index of at least 15) are presented. Patients were first treated with cyclosporine either 1.25 or 2.5 mg/kg/day (Sandimmune); in case of inadequate response the dosage was increased to a maximum of 5 mg/kg/day. Cyclosporine was given for 12 to 36 weeks. Treatment was classified as "successful" if the psoriasis area and severity index was reduced to 25% or less of the baseline value or below 8. At the end of the treatment period 18% of patients had improved their psoriasis area and severity index "successfully" with the initial dose of 1.25 mg/kg/day. "Successful" improvement with the initial dose of 2.5 mg/kg/day was achieved in 56% of the cases. In the 1.25 mg group, 44 patients had to increase their dose to 2.5 mg/kg/day and 31 patients to 5 mg/kg/day. In 29 patients whose dosages were started at 2.5 mg/kg/day the dosage was subsequently increased to 5 mg/kg/day. Although 1.25 mg/kg/day proved to be effective in some cases, 2.5 mg/kg/day of cyclosporine is the optimal starting dose. Adverse events were observed in 10% of the patients taking 1.25 mg/kg/day, in 20% taking 2.5 mg/kg/day, and in 32% taking 5 mg/kg/day. The most common were gastrointestinal complaints, followed by the common cold and other viral infections. An increase of serum creatinine level above 130 mumols/L occurred in five patients who could continue therapy after reducing the dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Neutrophil-activating proteins in psoriasis.

Neutrophil accumulation in the epidermis is a histologic characteristic of psoriasis. We addressed the question: What is the major protein-like chemotactic principle responsible for neutrophil accumulation? Purification of proteinaceous neutrophil chemoattractants from extracts obtained from psoriatic scales by multistep high-performance liquid chromatography (HPLC) yielded three biochemically distinct polypeptides with potent neutrophil chemotactic activity. Aminoterminal amino acid sequence analysis of the quantitatively major neutrophil attractant revealed the sequence ELRXQXIKTYSK, which is identical to that of a 69 residue form of neutrophil-activating peptide-1/interleukin 8 (NAP-1/IL-8). The second major attractant showed the sequence XXVATELRXQXL . . ., which is identical to that of the gene product of the oncogene "gro" as well as "melanoma growth stimulatory activity, MGSA," whereas the third and minor neutrophil chemotaxin has an NH2-terminal sequence identical with NAP-1/IL-8. Estimation of NAP-1/IL-8-related proteins and gro/MGSA by HPLC combined with bioassay revealed a mean of 3.3 +/- 1.7 ng NAP-1/IL-8-related proteins (n = 11) and 3.2 +/- 1.9 ng gro/MGSA (n = 11) per 1 mg psoriatic scales. In normal heel callus (n = 8), these neutrophil attractants were found at concentrations below 0.02 +/- 0.01 ng/mg. The finding of more than 150-times increased amounts of both NAP-1/IL-8 and gro/MGSA in lesional psoriasis material suggest that these mitogenic as well as neutrophil- and lymphocyte-chemotactic compounds may play an important role in the pathogenesis of psoriasis.

Amino Acid Sequence↗
PubMed1992

Lesional elastase activity in psoriasis, contact dermatitis, and atopic dermatitis.

Human leukocyte elastase (HLE) is a broad spectrum serine protease derived from neutrophils and macrophages. We developed an assay to determine HLE activity on the skin surface in patients with inflammatory skin diseases. HLE activity was absent in the skin of healthy controls. A massive increase of HLE activity was found in lesional skin of psoriasis (31 times), allergic contact dermatitis (55 times), and atopic dermatitis (35 times), but not in uninvolved skin of diseased patients. Therefore, this assay appears to represent a useful biochemical marker of epidermal inflammation. The presence of proteolytically active HLE in diseased epidermis, which is known to contain specific inhibitors of this enzyme, suggests a pathophysiologic role of this enzymatic activity in psoriasis, contact dermatitis, and atopic dermatitis.

Adult↗
PubMed1992

Inhibition of human monocyte functions by anthralin.

Anthralin is a well-established and widely used compound for topical treatment of psoriasis. In recent years attention has been focused on the anti-inflammatory properties of anthralin, with particular reference to psoriasis. In this study the effect of anthralin on human monocyte chemotaxis, superoxide-anion generation, and enzyme degranulation, were investigated. For comparison, the effect of the clinically inactive anthralin derivative danthrone and the solvent (acetone) were also studied. The results show that anthralin potently inhibits stimulated human monocyte superoxide-anion generation and enzyme degranulation, with a half-maximal inhibitory concentration (IC50) of as low as 0.02 micrograms/ml. Chemotactic migration of monocytes, however, was only affected when very high doses of anthralin (10 micrograms/ml) were used for pretreatment of the cells. Danthrone, up to a concentration of 10 micrograms/ml, or acetone alone (0.1%, v/v), did not inhibit the monocyte functions tested. Our results indicate that anthralin at pharmacological concentrations is a potent and selective inhibitor of human monocyte pro-inflammatory activities, by inhibiting respiratory burst activity (e.g. superoxide-anion generation) and enzyme degranulation, without affecting chemotactic migration.

Acetone↗
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

Elevated levels of NAP-1/interleukin-8 are present in the airspaces of patients with the adult respiratory distress syndrome and are associated with increased mortality.

The adult respiratory distress syndrome (ARDS) is characterized by increased neutrophils within the airspaces of the lungs. In order to determine if neutrophil activating protein (NAP)-1/interleukin-8 (NAP-1/IL-8) could be an important cause of neutrophil influx and activation in ARDS, we examined fluid, which was either directly aspirated or lavaged with saline from the lungs of patients with ARDS. NAP-1/IL-8 was present in significantly higher concentrations in the fluids of patients with ARDS compared with control subjects. There was a significant correlation between the percentage of neutrophils in the lavage fluids and the NAP-1/IL-8 concentration (r2 = 0.74). Furthermore, the NAP-1/IL-8 concentration of the pulmonary edema fluid was equivalent to the optimal concentration required to induce neutrophil chemotaxis in vitro. Although not all of the chemotactic activity of the edema fluid was removed by an anti-NAP-1/IL-8 affinity column, the data established that NAP-1/IL-8 is an important neutrophil chemotaxin in the airspaces of patients with ARDS. In addition, those patients with very high concentrations of NAP-1/IL-8 in their bronchoalveolar lavage fluids had a higher mortality rate than those patients with lower concentrations of NAP-1/IL-8. The correlation between NAP-1/IL-8 concentration and mortality is not paralleled by total protein concentration and mortality.

Adolescent↗
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

Neutrophil-activating peptide 1/interleukin 8 mRNA expression and protein secretion by human monocytes: effect of cyclosporin A.

Neutrophil-activating peptide 1/interleukin 8 (NAP-1/IL-8) is a recently described cytokine with potent chemotactic activity for human neutrophil granulocytes (PMN) and T cells. In psoriasis, a chronic hyperproliferative and inflammatory skin disorder, PMN and T cells are found as prominent cells in the inflammatory infiltrate of the lesions; however, monocytes were shown to be the first cells invading a newly formed plaque. NAP-1/IL-8 was found to be present in high amounts in the skin and in scale material of psoriatic patients. Psoriasis responds well to systemic treatment with cyclosporin A (CsA), an immunosuppressive peptide. Therefore, we addressed the question of whether the clinical improvement of psoriatic patients during CsA therapy may be due to an inhibition of NAP-1/IL-8 production and secretion from monocytes. Purified human monocytes were stimulated by lipopolysaccharide in the presence or absence of various concentrations of CsA. Production of NAP-1/IL-8 was determined as expression of specific mRNA by fluorescent in situ hybridization. Secreted peptide was measured by bioassay (PMN chemotaxis) and enzyme-linked immunosorbent assay (ELISA) using specific monoclonal antibodies. The results show that CsA neither inhibited mRNA expression for NAP-1/IL-8 nor secretion of the peptide. These findings support the hypothesis that the pharmacological effect of CsA may be restricted to the inhibition of T-cell activation and proliferation.

Cyclosporins↗
PubMed1991

Inflammatory properties of neutrophil-activating protein-1/interleukin 8 (NAP-1/IL-8) in human skin: a light- and electronmicroscopic study.

Neutrophil-activating protein-1/interleukin 8 (NAP-1/IL-8), purified to homogeneity from lipopolysaccharide-stimulated human peripheral blood monocytes, was injected intracutaneously into human skin. Sequential biopsy specimens were taken in order to investigate the sequence of ultrastructural changes induced by the cytokine. Whereas intracutaneous injection of 100 ng of NAP-1/IL-8 per site caused no macroscopic changes, by histology infiltration with polymorphonuclear leukocytes (PMN) and monocytes was present within 1 h and increased at 3 and 5 h. No lymphocyte infiltration was noted. The first ultrastructural changes (30 min) consisted of the presence of cytoplasmic 7-nm microfilament bundles, as well as numerous protrusions of the luminal plasma membrane of endothelial cells (EC). As a striking feature, multiple 100- to 160-nm electron lucent vesicles could be observed in the EC cytoplasm. These structures differed from plasmalemmal vesicles and suggest secretory activity. When PMN and monocytes appeared in the vascular lumen (1 h and later), the number of 100-160-nm electron-lucent vesicles had decreased significantly. In contrast to C5a-injected skin sites, mast cell degranulation was absent.

Complement C5a↗