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Biomedical subjects

R Kaufmann

Publications and source records attributed to R Kaufmann.

At least 73 records · Page 4Linked to original sources
PubMed2001

Monitoring of phagocytic activity in histiocytic cytophagic panniculitis.

Histiocytic cytophagic panniculitis presents with subcutaneous panniculitis. Histologically, it is characterized by phagocytosis of blood cells in the subcutaneous tissue and bone marrow. One patient with histiocytic cytophagic panniculitis is described in whom hemophagocytosis macrophages and histiocytes was observed histologically and was confirmed in vitro measuring phagocytosis by peripheral blood monocytes by means of chemiluminescence. In vitro measurements of phagocytosis corresponded well with the clinical course. Chemiluminescence for measuring phagocytosis in vitro may be suitable for analyzing disease activity and for testing therapeutic compounds in vitro.

Adult↗
PubMed2001

Calcipotriol solution for the treatment of scalp psoriasis: evaluation of efficacy, safety and acceptance in 3,396 patients.

BACKGROUND: Psoriasis of the scalp is a very common disease, cosmetically disturbing and therapeutically difficult to manage. OBJECTIVE: The aim of our study was to investigate the efficacy, safety and cosmetic acceptance of calcipotriol solution in a large number of patients with mild to moderate scalp psoriasis and to compare this treatment with previous therapies used. METHODS: In this multicentre prospective observational cohort study 3,396 patients were treated with calcipotriol solution (50 microg/ml) twice daily over an 8-week period either alone or in combination with other treatments. The psoriasis scalp severity index (PSSI) and investigator/patient global assessment were used for the evaluation of clinical response. RESULTS: All psoriasis severity parameters measured were reduced with a significant decrease in PSSI scores from 18.4 to 5.6 after 8 weeks of therapy (p < 0.001). About 80% of the patients showed very good or good clinical improvement. Combination of calcipotriol solution with other treatment modalities e.g. corticosteroids or salicylic acid, showed an increased treatment response. In only 2.4% of the patients side effects occurred (e.g. irritation). CONCLUSION: Calcipotriol solution is an effective, safe, well-tolerated and cosmetically acceptable treatment modality. By patients and physicians, this treatment was found to be a valuable supplement to previously available and established treatments for scalp psoriasis.

Adult↗
PubMed2001

Effects of mechanical force on primary human fibroblasts derived from the gingiva and the periodontal ligament.

Previous experiments have shown that mechanical stress may alter the interactions between cells and extracellular matrix (ECM). The purpose of our study was to investigate the effects of mechanical load on metabolism and ECM expression of primary human periodontal cells. The influence of gravitational force on proliferation, lactate dehydrogenase (LDH) release, and tenascin expression of gingival (HGF) and periodontal ligament fibroblasts (HPDL), as well as their adhesion to various extracellular matrix (ECM) components, was determined. Cells were centrifuged in microplates or flat tubes for 16 hrs at 217 g. Neither an enhanced release of LDH nor an alteration of cell proliferation could be detected after centrifugation. However, the attachment of loaded gingival and periodontal ligament fibroblasts to all tested ECM components significantly decreased in comparison with controls (Wilcoxon-Mann-Whitney test; HGF, p < 0.05; HPDL, p < 0.01). Tenascin expression of mechanically stressed fibroblasts significantly increased in comparison with controls (p < 0.01).

Cell Adhesion↗
PubMed2001

Mycophenolate mofetil is effective in the treatment of atopic dermatitis.

OBJECTIVE: To evaluate whether mycophenolate mofetil, a new immunosuppressive agent, is effective for treating moderate-severe atopic dermatitis (AD). DESIGN: In an open-label pilot study, mycophenolate mofetil, 1 g, was given orally twice daily for 4 weeks. At week 5, the dosage was reduced to 500 mg twice daily until study end (week 8). Patients were followed up for 20 weeks. SETTING: University hospital dermatology department. PATIENTS: Ten consecutive patients with moderate-severe AD nonresponsive to standard therapy. MAIN OUTCOME MEASURE: Severity of AD as measured using the subjective SCORAD [SCORing Atopic Dermatitis] index. RESULTS: Clinical efficacy was measured every 2 weeks using the subjective SCORAD index. Treatment with mycophenolate notably reduced the severity of AD within 4 weeks in all patients (P<.05), and after 8 weeks the mean +/- SD SCORAD index dropped from the pretreatment value of 49.2 +/- 13.8 to 21.9 +/- 26.5 (P<.01). One patient had to discontinue mycophenolate therapy after 4 weeks because of the development of herpes retinitis. Except for this event, mycophenolate was tolerated well in all patients. Six of 7 patients who had responded to mycophenolate monotherapy had no relapse of disease during 20-week follow-up. In the 7 patients who finished the study, the SCORAD index was reduced by 74%, from 44.0 +/- 7.8 before treatment to 11.4 +/- 5.9 at 20-week follow-up. CONCLUSIONS: Mycophenolate is a highly effective drug for treating moderate-severe AD, with no serious adverse effects occurring in any patients. Thus, mycophenolate might develop into a promising alternative in the therapy of moderate-severe AD.

Administration, Oral↗
PubMed2000

Identification of copper/zinc superoxide dismutase as a nitric oxide-regulated gene in human (HaCaT) keratinocytes: implications for keratinocyte proliferation.

Recent studies have demonstrated an induction of expression of inducible nitric oxide synthase that is associated with several inflammatory diseases of the skin. To define the mechanisms of action of nitric oxide (NO) in the skin, we attempted to identify genes that are regulated by NO in keratinocytes. Using the human keratinocyte cell line HaCaT as a model system, we identified a Cu/Zn superoxide dismutase (SOD) that was strongly induced by high concentrations (500 microM) of NO-donating agents ¿S-nitrosoglutathione, sodium nitroprusside and (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2 -diolate (DETA-NO)¿, but not by serum or by single recombinant growth factors and inflammatory cytokines or by treatment with superoxide anions. Furthermore, endogenously produced NO increased the expression of Cu/Zn SOD mRNA in keratinocytes. Moreover, treatment of HaCaT cells with NO was associated with a biphasic effect on cell proliferation, because low doses (100 microM) of different NO donors (S-nitrosoglutathione and DETA-NO) mediated a proliferative signal to the cells, whereas high concentrations (500 microM) were cytostatic. To determine a possible correlation between the close regulation of Cu/Zn SOD expression and proliferation by NO in keratinocytes, we established a cell line (psp1CZ1N) carrying a human Cu/Zn SOD cDNA under the control of a ponasterone-inducible promoter construct. Ponasterone-induced overexpression of Cu/Zn SOD caused a cytostatic effect in proliferating psp1CZ1N cells. We therefore suggest that the up-regulation of Cu/Zn SOD expression by NO establishes an inhibitory mechanism on keratinocyte proliferation.

Base Sequence↗
PubMed2000

Meizothrombin, an intermediate of prothrombin activation, stimulates human glioblastoma cells by interaction with PAR-1-type thrombin receptors.

Thrombin induces well-characterized effects on normal and neoplastic brain cells by interaction with protease-activated receptor (PAR)-type thrombin receptors. However, nothing is known about the function of intermediate enzymes of prothrombin activation recently shown to evoke PAR-1-mediated signaling in smooth muscle cells. Therefore, we investigated the effect of recombinant human meizothrombin (rMT), one of thrombin's catalytically active precursor enzymes in the prothrombin cleavage cascade, on calcium mobilization in human SNB-19 glioblastoma cells. By using reverse-transcription polymerase chain reaction, immunofluorescence studies with a monoclonal anti-PAR-1 antibody and calcium measurements, SNB-19 cells were shown to express functional PAR-1-type thrombin receptors. PAR-1 is not only a receptor for thrombin in SNB-19 cells but was also activated by rMT very effectively. Under the conditions used in our experiments, SNB-19 cells stimulated with thrombin after rMT challenge were unable to elicit a new calcium response and vice versa. In addition, both rMT and thrombin induced no further calcium signal after that observed with the PAR-1-activating peptide SFLLRN. Therefore, rMT and thrombin seem to activate calcium signaling by similar mechanisms including PAR-1. Our results demonstrate rMT as a potent activator of PAR-1-type thrombin receptors in SNB-19 glioblastoma cells, suggesting a function of catalytically active thrombin precursor enzymes in cells of glial origin.

Calcium↗
PubMed2000

Genotoxic potential of porphyrin type photosensitizers with particular emphasis on 5-aminolevulinic acid: implications for clinical photodynamic therapy.

Photodynamic therapy (PDT) uses exogenously administered photosensitizers activated by light to induce cell death or modulation of immunological cascades, presumably via formation of reactive oxygen species (ROS). 5-Aminolevulinic acid (ALA) mediated photosensitization is increasingly used for the treatment of nonmelanoma skin cancer and other indications including benign skin disorders. Long-term side effects of this investigational modality are presently unknown. Just as tumor treatments such as ionizing radiation and chemotherapy can cause secondary tumor induction, PDT may potentially have a carcinogenic risk. Evaluation of the biological effects of ALA in absence of activating light and analysis of the mechanism of ALA-PDT and porphyrin-type photosensitizers mediated photosensitization indicate that this therapy has a pro-oxidant and genotoxic potential. However, porphyrin type molecules also possess antioxidant and antimutagenic properties. ALA-PDT delays photocarcinogenesis in mice, and topical ALA alone does not increase skin cancer incidence in these animals. Patients with increased tissue levels of ALA have an increased incidence of internal carcinoma, however, it is not clear whether this relationship is casual or causal. There is no evidence indicating higher rates of skin cancer in patients with photosensitivity diseases due to presence of high protoporphyrin IX (PP) levels in skin. Overall, the presently available data indicate that the risk for secondary skin carcinoma after topical ALA-PDT seems to be low, but further studies must be carried out to evaluate the carcinogenic risk of ALA-PDT in conditions predisposed to skin cancer.

Aminolevulinic Acid↗
PubMed2000

The two-receptor system PAR-1/PAR-4 mediates alpha-thrombin-induced [Ca(2+)](i) mobilization in human astrocytoma cells.

The proteinase-activated receptor 1 (PAR-1) was characterized as a functional receptor for thrombin in cells from different brain tumor entities. Whether PAR-1 alone accounts for thrombin-induced effects in human cancer cells, or whether other PAR contribute is unknown. We established primary cultures from two neurosurgically removed human astrocytomas and investigated intracellular signaling roles of PAR-1 and PAR-4 by estimating the effect of alpha-thrombin and PAR-activating peptides on [Ca(2+)](i) mobilization in single astrocytoma cells. alpha-Thrombin or the PAR-1-activating peptide SFLLRN induced a transient calcium mobilization. This suggests the involvement of PAR-1 in alpha-thrombin-induced calcium signaling in human astrocytoma cells. In addition, a second, PAR-4-dependent, mechanism exists. This was deduced from the findings that a further calcium signal could be observed in human astrocytoma cells stimulated with alpha-thrombin after SFLLRN and the PAR-4-activating peptide GYPGQV also induced a calcium response. In addition, the observation that trypsin, known to activate both PAR-2 and PAR-4, but not the specifically PAR-2-activating peptide SLIGRL induced calcium signaling is a further indication of functional PAR-4-type thrombin receptors in human astrocytoma cells. This is the first report demonstrating a signaling role for a dual thrombin receptor system in human tumor cells.

Apoptosis Regulatory Proteins↗
PubMed2000

[The UV record. Document for quality control, therapy planning and risk assessment in dermatologic photo- and photochemotherapy].

Ultraviolet (UV-) radiation therapy as a mono- or combination therapy (UV-A, UV-A1, UV-B, SUP, UV-B311) or as photochemotherapy with photosensitization (systemic PUVA-, bath PUVA-, topical PUVA-therapy) are successfully used for the treatment of several dermatological disorders. Long-term side effects of natural UV (sun light) include photoaging and induction of skin tumors. At present, the relevance of in-vitro findings of potential tumor induction in animals through therapeutic levels of UV radiation is a matter of debate. To assess these risks, information on treated location, kind of UV radiation and cumulative UV doses are required. Practically this information is barely accessible. This makes decisions on possible therapies difficult. To solve this problem we propose to use an "UV pass". At the end of each UV radiation cycle, the body location, the type of radiation and the cumulative dose are documented and this pass is given to the patient. This will improve the information transfer if the doctor is changed, as well as facilitating decisions about certain therapies and calculation of long-term risks of UV radiation. Finally it will improve the quality of UV photo- and photochemotherapy.

Dose-Response Relationship, Radiation↗
PubMed2000

[Cutaneous variant of Langerhans cell histiocytosis in early childhood].

The term Langerhans cell histiocytosis (LCH) has been endorsed to describe a group of rare entities, a highly variable spectrum of clinical presentations which are all characterized by localized or generalized proliferation of pathological Langerhans cells. We describe two infants with LCH who had very distinct cutaneous lesions. A two month-old infant developed discrete, disseminated red-brown nodules and plaques. In contrast, a second child at the age of nine months presented with brown aggregated scaling, crusted and ulcero-necrotic papules mainly restricted to the abdomen. In both patients, dermatohistopathology showed characteristic proliferation of pathologic Langerhans cells, and staging procedures revealed involvement of lung and bones. These two cases illustrate the marked variability of clinical presentation and disease course of LCH. In addition, important aspects and current concepts of LCH are discussed reviewing relevant and recent literature.

Biopsy↗
PubMed2000

Melanocytes respond to mechanical stretch by activation of mitogen-activated protein kinases (MAPK).

Cells of human epidermis are permanently targeted by mechanical stimuli. Besides mechanical forces from external sources the body itself generates mechanical forces via muscle contractions and growth processes. Recently, it was demonstrated that mechanical stretch is connected to enhanced proliferation in epidermal cells. The underlying biochemical events are still a matter of debate. Here we show that mechanical stretch leads to activation of both ERK1/2 and SAPK/JNK in human melanocytes and keratinocytes. In response to a 5 min single stretch ERK1/2 becomes moderately induced in melanocytes and peaked 30 min after the stimulus. In keratinocytes strong activation of ERK1/2 is present directly after the stimulus. SAPK/JNK shows the same activation pattern in both cell species--a slow but steady activation. The different kinetics of both MAPK suggest that different signalling cascades were activated. Future studies should evaluate the relevance of stretch-dependent MAPK activation in triggering the cell proliferation.

Cell Line↗