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Featured researches published by J.C. Meyer.


Dermatology | 1984

Soft X-irradiation influences the integrity of Langerhans cells. A histochemical and immunohistological study.

Veronica Groh; J.C. Meyer; R. Panizzon; Claudia Zortea-Caflisch

This report defines the influence of field soft X-ray irradiation on the integrity of epidermal Langerhans cells (LC) in the guinea pig and mouse systems. Male albino (Rockefeller strain) and piebald F 1 (2 X 13 strain) guinea pigs as well as C3H mice (H-2Kk) were exposed to one single shot of different dosages of soft X-rays [80, 1,200, 1,600, and 3,200 R; 30 kV, 0.5 mm aluminium filter, FSD (focus-skin distance) 12 cm]. 1 and 4 weeks after exposure, skin specimens were taken from the irradiated skin. The demonstration and evaluation of LC was performed basing on their expression of specific histochemical (ATPase) and functional immunologic markers (Ia antigens). Soft X-irradiation had pronounced effects on number and structure of ATPase- and Ia-antigen-positive cells. In the mouse system, 1 week after exposure to 800 and 1,200 R ATPase-positive cells and, in a more or less parellel manner, Ia-antigen-positive cells () were reduced to 74% (74%) and 70% (68%), respectively, and 4 weeks after exposure to 49% (47%) and 43% (40%), respectively. In the guinea pig system one single shot of 1,600 or 3,200 R produced, respectively, a 35% or a 38% reduction of ATPase-positive cells. Prolonged survival did not result in a further depletion of ATPase-positive cells.


Dermatology | 1982

Rapid Laboratory Diagnostic of X-Linked Ichthyosis

J.C. Meyer; Veronica Groh; V. Giger; Heidi Weiss; H. Varbelow; U.W. Schnyder

Steroid sulfatase and aryl sulfatase C activities were assayed simultaneously in peripheral blood leucocytes of 4 patients with X-linked ichthyosis (XLI) and 4 patients with autosomal-dominant ichthyosis; 11 healthy subjects served as controls. The deficiency of steroid sulfatase as well as of aryl sulfatase C found in leucocytes of patients with XLI was confirmed by the histochemical demonstration of aryl sulfatase C deficiency in skin sections. Although results are obtained earlier with the histochemical method than with the biochemical assay in leucocytes, several disadvantages brought us to the conclusion that the biochemical assay of microsomal sulfatase activity in leucocytes offers a fast and safe method for the identification of patients with XLI.


Dermatology | 1985

Plasma Concentrations of Beta-Carotene and Canthaxanthin during and after Stopping Intake of a Combined Preparation

J.C. Meyer; H. P. Grundmann; B. Seeger; U.W. Schnyder

During 17 days two groups of 6 and 8 volunteers of the Department of Dermatology ingested 4 and 6 capsules per day of carotenoids (10 mg beta-carotene + 15 mg canthaxanthin per capsule; Phenoro). Heparinized blood was collected twice a week until day 21 and then weekly until day 77. Concentrations of beta-carotene and canthaxanthin in plasma were analyzed by high-performance liquid chromatography during 77 days. Plasma levels of carotenoids were higher in group 2 (6 capsules) than in group 1 (4 capsules) but reached maximum concentrations within the same time. Hence, therapeutic plasma levels of beta-carotene were reached earlier in group 2. According to blood levels, group 2 could be clearly divided in low and high responders. In contrast to canthaxanthin, beta-carotene exhibited a biphasic decline in both groups, with a monophasic asymptotic decrease which was expressed clinically by a pronounced orange to yellow pigmentation of the skin.


American Journal of Dermatopathology | 1997

Expression of intercellular adhesion molecule 3 (CDw50) on endothelial cells in cutaneous lymphomas: A comparative study between nodal and cutaneous lymphomas

Stefan Dommann; Corina Dommann-Scherrer; Thomas Ziegler; J.C. Meyer; Ralph M. Trüeb; Thomas M. Kündig; R. Panizzon; Günter Burg

Advances in the molecular definition of surface proteins (adhesion molecules) involved in tumor metastasis may help to explain the invasive behavior of malignant tumors, that is, the migration of tumor cells involving reversible adhesive contacts, their release in the circulation, and their extravasation into distant sites. Intercellular adhesion molecule-3 (ICAM-3), the third receptor for the lymphocyte function-associated antigen molecule-1 (LFA-1) was recently characterized. We investigated fresh frozen skin biopsies from 10 patients with mycosis fungoides, four with pleomorphic T-cell lymphoma, six with Sézary syndrome, 10 with primary cutaneous B-cell lymphoma, and 10 with eczematous lesions as controls. The biopsies were compared with lymph node biopsies of five patients with known cutaneous T-cell lymphoma (CTCL), 10 with primary nodal B-cell lymphoma, and 11 with lymph-node specimens showing dermatopathic lymphadenopathy as controls. The specimens were stained with ICAM-3 antibody (Bender Medical Science) using the alkaline phosphatase antialkaline phosphatase method. Using cytomorphologic criteria, neoplastic lymphocytes could be differentiated from smaller reactive cells. Staining intensities were classified semiquantitatively as follows: 4, strong expression in 75 to 100% of the tumor cells; 3, 50 to 75%; 2, 25 to 50%; 1, 5 to 25%; and 0 fewer than 5% of the tumor cells. The endothelial cells in skin biopsies of seven of 30 primary cutaneous lymphomas expressed ICAM-3. In contrast, no expression of ICAM-3 could be demonstrated on endothelial cells in lymph nodes infiltrated with tumor cells of CTCL. Finally, endothelial cells of lymph nodes infiltrated with primary nodal B-cell lymphomas showed expression of ICAM-3 in three of 10 patients. The endothelial cells in the 11 control patients presenting with both eczematous lesions and dermatopathic lymphadenopathy showed no staining for ICAM-3. Every patient who expressed ICAM-3 on endothelial cells showed systemic spread of this disease. The findings suggest that ICAM-3 expression may be induced on endothelial cells in late-stage cutaneous lymphomas, probably by a cytokine-mediated mechanism.


Dermatology | 1989

Factors Affecting Plasma Levels of Ketoconazole during Long-Term Treatment

J.C. Meyer; C. Burri; P. Ruf; U.W. Schnyder

In the present study we intended to obtain information on the evolution of near-peak blood levels during long-term treatment. 56 patients with an indication for systemic treatment of nail or skin mycoses obtained a daily dose of 200 mg ketoconazole. They were periodically checked for blood level of ketoconazole, clinical and mycological status and enzyme values. The average blood level was 2.8 +/- 1.3 micrograms/ml plasma. The blood level was not influenced by the length of the treatment. A correlation between blood level and weight or sex was not observed, whereas a significant negative correlation occurred between blood level and age (age group 15-30 years: 3.9 +/- 1.3 micrograms/ml; 46-60 years: 2.4 +/- 0.9 micrograms/ml).


BMC Infectious Diseases | 2013

Decreased susceptibility of Neisseria gonorrhoeae isolates from Switzerland to Cefixime and Ceftriaxone: antimicrobial susceptibility data from 1990 and 2000 to 2012

Helen Kovari; Maria Dg de Melo Oliveira; Paula Hauser; Severin Läuchli; J.C. Meyer; Rainer Weber; Reinhard Zbinden

BackgroundNeisseria gonorrhoeae can rapidly develop resistance to antimicrobial agents. Over the last years, decreased gonococcal susceptibility to third-generation cephalosporins, especially cefixime, emerged worldwide. Therefore, current international guidelines recommend dual therapy for gonorrhoea with ceftriaxone plus either azithromycin or doxycycline. Gonococcal susceptibility data in Switzerland are sparse.MethodsWe investigated the prevalence of antibiotic susceptibility of N. gonorrhoeae in specimens collected between 1990 and 2012 at the University of Zurich, Switzerland. Minimum inhibitory concentrations (MICs) for cefixime, ceftriaxone, ciprofloxacin, and penicillin were determined by Etests. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints were used to define reduced susceptibility.ResultsA total of 320 isolates were tested. Between 1990 and 2006 all tested samples were susceptible to both cephalosporins. Subsequently, the prevalence of elevated MICs for cefixime increased to 10.4% (2007/2008), 11.5% (2009/2010), and 11.4% (2011/2012); and for ceftriaxone to 2.4% (2007/2008), 4.7% (2009/2010), and 0% (2011/2012), respectively. The prevalence of resistance to ciprofloxacin (72.7%) and penicillin (22.7%) was high in 2011/2012.ConclusionsDecreasing susceptibility of N. gonorrhoeae to third-generation cephalosporins in Switzerland supports treatment recommendations with ceftriaxone plus azithromycin or doxycycline. Health-care providers need to be aware of possible treatment failures with cephalosporins. Continued surveillance of gonococcal antimicrobial resistance is essential.


Dermatology | 1990

Properties of acid phosphatase in human stratum corneum.

J.C. Meyer; H. P. Grundmann; Susi Knabenhans

Sheets of stratum corneum were prepared by a trypsinization procedure from human skin samples, homogenized with a freeze press and then fractionated into a soluble fraction and a sediment by centrifugation at 50,000 g. Acid phosphatase (AcP) activity was found in both fractions but the bulk of the activity was detected in the supernatant. Highest activities were observed after treatment with Triton X-100. The bulk of the AcP activity remained bound to the pellet, if suspension and fractionation of the homogenized stratum corneum were performed in acetate buffer in the range between pH 4.0-5.0, probably due to ionic or hydrophobic interactions. AcP activity was totally lost if homogenates or fractions were stored frozen at -20 degrees C in buffers with pH values lower than 4.0. Triton X-100 extracts from whole skin, epidermis, stratum corneum, cultured skin fibroblasts and leukocytes were compared by isoelectric focusing. Extracts from whole skin, epidermis and stratum corneum yielded almost identical patterns with one main AcP activity band at pI of 5.65, whereas a second pronounced band from whole skin behaved similarly to one band from cultured skin fibroblasts and leukocytes (pI 6.1). The prominent band from extracts of stratum corneum and epidermis was not observed in extracts of skin fibroblasts and leukocytes. Hence, we conclude that stratum corneum and epidermis contain a tissue-specific AcP.


Dermatology | 1984

Steroid Sulfatase = Aryl Sulfatase C? Chromatographic and Electrophoretic Properties in Extracts from Placental Microsomes and Skin Fibroblasts

J.C. Meyer; H. P. Grundmann; Heidi Weiss

Although the deficiency of steroid sulfatase (STS) as well as aryl sulfatase C (ASC) activities in patients with X-linked recessive ichthyosis has been confirmed by several groups all over the world, the question whether STS = ASC is not yet completely answered. To obtain more information, Miranol H2M extracts from placental microsomes and cultured skin fibroblasts were subjected to gel permeation chromatography and polyacrylamide gel electrophoresis. STS (3H-dehydroepiandrosterone sulfate) and ASC (4-methylumbelliferone sulfate) activities were estimated in the eluted gel permeation chromatography fractions and within the same gel cylinders in half gel slices. None of these two methods allowed a separation of the two microsomal sulfatase activities. From these results and from different behavior of STS and ASC (not deficient in uncultured skin preparations of X-linked recessive ichthyosis, different kinetic properties between STS and ASC, etc.) we propose microsomal sulfatase activities to be assembled in an enzyme aggregate.


Dermatology | 1979

Spättyp-Überempfindlichkeit gegenüber Staphylokokkenantigenen bei Meerschweinchen

J.C. Meyer; H. P. Grundmann; Heidi Weiss; H. Trachsel

Delayed type hypersensitivity against staphylococcal antigens could be induced in guinea pigs by injecting the animals with a staphylococcal homogenate in Freunds adjuvant in all four foot pads and the nuchal skin. Maximal skin reactivity, tested intracutaneously, was observed 21 days after sensitization. Highest stimulation of lymph node cells and peripheral blood lymphocytes was also obtained 21 days after sensitization. When comparing cell walls, cell materials (nonsoluble material obtained after the separation of the cell wall fraction) and soluble fraction (obtained after sedimentation of all nonsoluble material, the strongest skin test reactions occurred after testing intracutaneously with the cell wall fraction.Delayed type hypersensitivity against staphylococcal antigens could be induced in guinea pigs by injecting the animals with a staphylococcal homogenate in Freund’s adjuvant in all four foot pads and the nuchal skin. Maximal skin reactivity, tested intracutaneously, was observed 21 days after sensitization. Highest stimulation of lymph node cells and peripheral blood lymphocytes was also obtained 21 days after sensitization. When comparing cell walls, cell materials (nonsoluble material obtained after the separation of the cell wall fraction) and soluble fraction (obtained after sedimentation of all nonsoluble material, the strongest skin test reactions occurred after testing intracutaneously with the cell wall fraction.


Dermatology | 1994

Various Cytokines Modulate ICAM-1 Shedding on Melanoma- and CTCL-Derived Cell Lines: Inverse Regulation of ICAM-1 Shedding in a Sézary Cell Line by Interferon-γ

Reinhard Dummer; S. Sigg-Zemann; K. Kalthof; S. Muletta; J.C. Meyer; G. Burg

BACKGROUND Since soluble intercellular adhesion molecules 1 (sICAM-1) retain their ability to bind to their ligand, they can interfere in cell-mediated immunosurveillance. OBJECTIVE We studied the impact of various cytokines on ICAM-1 release of several tumor cell lines. METHODS Two melanoma cell lines (M19, M26), 1 B lymphoblastoid cell line (Daudi), 1 erythroleukemia cell line (K562), 1 Sézary-cell-derived cell line (SeAx), 1 cell line derived from a mycosis fungoides lesion (MyLa) and normal peripheral blood mononuclear cells (PBMC) were grown in the presence of interferon gamma (IFN-gamma), IFN-alpha, interleukin-2 (IL-2), IL-6 and tumor necrosis factor alpha (TNF-alpha) in various concentrations. ICAM-1 release into the supernatant was measured after 24 and 48 h using an enzyme-linked immunosorbent assay (ELISA). RESULTS PBMC and the B lymphoblastoid cell line did not shed detectable amounts of sICAM-1. In all other cell lines, ICAM-1 shedding was found with and without cytokine stimulation. In all cell cell lines except the CTCL-derived one, ICAM-1 shedding was marginally affected by IFN-alpha, IL-2 and IL-6. TNF-alpha and IFN-gamma enhanced the shedding in a time- and dose-dependent manner. In the SeAx line, IL-2 and IFN-gamma inhibited ICAM-1 release. By contrast, TNF-alpha and IL-6 enhanced it. The CTCL-derived MyLa responded to IFN-alpha with a dose-dependent increase in ICAM-1 shedding. All other cytokines had marginal influence. CONCLUSION Cytokine-modulated ICAM-1 shedding shows quantitative and qualitative differences in the investigated cell lines. This might have implications for the pathophysiology of cutaneous malignancies and their susceptibility to immunotherapies.

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C. Burri

University of Zurich

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