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Biomedical subjects

Thomas Ruzicka

Publications and source records attributed to Thomas Ruzicka.

At least 55 records · Page 3Linked to original sources
PubMed2005

[Acute localized exanthematous pustulosis (ALEP)].

Acute generalized exanthematic pustulosis (AGEP) is characterized by a generalized rash and sterile disseminated, sometimes coalescing subcorneal pustules. It occurs in body flexures such as the inguinal folds and intertriginous areas. The acute onset of disease is accompanied by malaise, fever > 38 degrees C and peripheral granulocytosis. We report on a female patient who according to the criteria of AGEP was diagnosed as having acute localized exanthematic pustulosis (ALEP) on the face.

Acute Disease↗
PubMed2004

Socioeconomic factors in lupus erythematosus.

For a long time, systemic lupus erythematosus (SLE) was considered a potentially deadly disease. Since the introduction of immunosuppressive therapy, the life expectancy and the quality of life of patients suffering from lupus erythematosus has been dramatically improved. Today, the 5-year survival rate for SLE varies between 50% and 95%. Still, not all patients benefit equally from medical advances. Ethnic and/or socioeconomic minorities show severely disadvantageous prognosis or outcome in various studies. A substantial reduction in the quality of life as well as unemployment are other frequent side effects of this disease. Vocational handicaps related to discoid lupus erythematodes (DLE) was seen in nearly 45% of the patients. Therefore, the management of lupus erythematosus patients requires interdisciplinary cooperation between physicians, psychologists and social workers. The major aim of this article is to summarize the history of lupus erythematosus on the one and the other hand to consider the role of the socioeconomic factors influencing the prognosis of systemic and cutaneous lupus erythematosus.

Humans↗
PubMed2004

CC chemokine ligand 18, an atopic dermatitis-associated and dendritic cell-derived chemokine, is regulated by staphylococcal products and allergen exposure.

Atopic dermatitis is a chronic inflammatory skin disease with a steadily increasing prevalence. Exposure to allergens or bacterial superantigens triggers T and dendritic cell (DC) recruitment and induces atopic skin inflammation. In this study, we report that among all known chemokines CCL18/DC-CK1/PARC represents the most highly expressed ligand in atopic dermatitis. Moreover, CCL18 expression is associated with an atopic dermatitis phenotype when compared with other chronic inflammatory skin diseases. DCs either dispersed within the dermis or clustering at sites showing perivascular infiltrates are abundant sources of CCL18. In vitro, microbial products including LPS, peptidoglycan, and mannan, as well as the T cell-derived activation signal CD40L, induced CCL18 in monocytes. In contrast to monocytes, monocyte-derived, interstitial-type, and Langerhans-type DCs showed a constitutive and abundant expression of CCL18. In comparison to Langerhans cells, interstitial-type DCs produced higher constitutive levels of CCL18. In vivo, topical exposure to the relevant allergen or the superantigen staphylococcal enterotoxin B, resulted in a significant induction of CCL18 in atopic dermatitis patients. Furthermore, in nonatopic NiSO4-sensitized individuals, only relevant allergen but not irritant exposure resulted in the induction of CCL18. Taken together, findings of the present study demonstrate that CCL18 is associated with an atopy/allergy skin phenotype, and is expressed at the interface between the environment and the host by cells constantly screening foreign Ags. Its regulation by allergen exposure and microbial products suggests an important role for CCL18 in the initiation and amplification of atopic skin inflammation.

Allergens↗
PubMed2004

Frequent alterations of Ras signaling pathway genes in sporadic malignant melanomas.

Ras signaling is important for the intracellular transduction of mitogenic stimuli from activated growth factor receptors. We have investigated 37 sporadic malignant melanomas (15 primary cutaneous melanomas and 22 melanoma metastases) and 6 melanoma cell lines for mutations in the 3 Ras genes NRAS, KRAS and HRAS. All tumors and cell lines were additionally analyzed for mutation and expression of BRAF, which encodes a Ras-regulated serine/threonine kinase with oncogenic properties, as well as for expression of RASSF1A, which encodes a Ras-binding protein with tumor suppressor properties. Mutational analyses identified somatic NRAS mutations in 2 primary melanomas, 4 melanoma metastases and 2 cell lines. One melanoma metastasis showed a somatic KRAS mutation whereas HRAS mutations were not detected. Eight primary melanomas, 6 melanoma metastases and 4 melanoma cell lines carried BRAF mutations affecting the known hot-spot codon 599. None of the tumors or cell lines with BRAF mutation demonstrated NRAS or KRAS mutations. Real-time reverse transcription-PCR showed that 8 melanomas (3 primary tumors, 5 melanoma metastases) had reduced RASSF1A transcript levels of < or =50% relative to benign melanocytic nevi and normal skin. Three melanoma cell lines lacked detectable RASSF1A transcripts. The RASSF1A gene promoter was hypermethylated in these 3 cell lines as well as in 6 of 8 melanomas with reduced RASSF1A mRNA levels. Treatment of the cell lines with 5-aza-2'-deoxycytidine and trichostatin A resulted in demethylation of the RASSF1A promoter and re-expression of RASSF1A transcripts. Most tumors and all cell lines with RASSF1A promoter methylation additionally carried BRAF or NRAS mutations, suggesting a synergistic effect of these aberrations on melanoma growth. Taken together, 57% of the investigated melanomas and 100% of the melanoma cell lines carried mutations in either NRAS, KRAS or BRAF. In addition, 22% of the melanomas and 50% of the cell lines showed reduced RASSF1A transcript levels. Thus, alterations of Ras pathway genes are of paramount importance in the pathogenesis of sporadic melanomas.

Adult↗
PubMed2004

Oral alitretinoin (9-cis-retinoic acid) therapy for chronic hand dermatitis in patients refractory to standard therapy: results of a randomized, double-blind, placebo-controlled, multicenter trial.

OBJECTIVE: To assess the efficacy and safety of oral alitretinoin (9-cis-retinoic acid), 10 mg/d, 20 mg/d, and 40 mg/d, compared with placebo control, in the treatment of chronic hand dermatitis. DESIGN: Multicenter, randomized, double-blind, placebo-control, prospective trial. SETTING: A total of 43 outpatient clinics in 10 European countries. PATIENTS: Of 348 patients screened, 319 with moderate or severe refractory chronic hand dermatitis were randomized, in the ratio of 1:1:1:1, to 4 treatment groups and received allocated intervention. Of 75 patients who withdrew, 24 withdrew owing to adverse events. INTERVENTIONS: Placebo or 10 mg, 20 mg, or 40 mg of oral alitretinoin (9-cis-retinoic acid) taken once daily for 12 weeks. Safety was assessed for all patients during a follow-up period of 4 weeks, and responders were observed for a follow-up period of 3 months. MAIN OUTCOME MEASURE: Physician's global assessment of overall chronic hand dermatitis severity. RESULTS: Alitretinoin led to a significant and dose-dependent improvement in disease status, with responses in up to 53% of patients, and up to a 70% mean reduction in disease signs and symptoms. Treatment was generally well tolerated, with dose-dependent effects comprising headache, flushing, mucocutaneous events, hyperlipidemia, and decreased hemoglobin and decreased free thyroxin levels. Three months after discontinuation of treatment, the rate of relapse was 26%, independent of dose. CONCLUSION: Alitretinoin given at well-tolerated doses induced substantial clearing of chronic hand dermatitis in patients refractory to conventional therapy.

Administration, Oral↗
PubMed2004

DNA mismatch repair and the significance of a sebaceous skin tumor for visceral cancer prevention.

DNA mismatch repair is a postreplicative DNA repair cascade ensuring genomic integrity. Inactivating germline mutations in DNA mismatch repair genes are responsible for hereditary non-polyposis colorectal carcinoma syndrome (HNPCC), which predisposes to various types of visceral cancer. Most associated tumors exhibit high-grade microsatellite instability. Some patients develop skin tumors of the sebaceous glands. This combined occurrence is known as Muir-Torre syndrome, which has a high probability of an underlying DNA mismatch repair defect. This is also true for individuals selected solely on the basis of sebaceous neoplasias, tumors with the highest frequency of high-grade microsatellite instability. This article focuses on the recent advances in molecular diagnostics for the detection of DNA mismatch repair defects in patients with sebaceous neoplasias, and the potential significance for the secondary prevention of visceral cancer in these patients.

Adaptor Proteins, Signal Transducing↗
PubMed2004

Topical immunomodulation in dermatology: potential of toll-like receptor agonists.

BACKGROUND: Topical immunomodulators include both immunostimulatory and immunosuppressive agents. If successful, topical immunotherapy may represent an important improvement in the therapy of inflammatory dermatoses, viral infections, and cancers of the skin and genital mucosa. Topical immunotherapy using obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene has been used against viral (e.g., common warts) and autoimmune diseases (e.g., alopecia areata). RESULTS: Newer agents such imidazoquinolines (imiquimod and resiquimod) act by cytokine secretion from monocytes/macrophages (interferon-alpha, interleukin-12, tumor-necrosis factor-alpha). The locally generated immune milieu leads to a Th1-dominance and cell-mediated immunity that have been clinically used to treat viral infections such as human papillomavirus, herpes simplex virus, and mollusca. Although these agents improve antigen presentation by dendritic cells, they also act on B cells leading to the synthesis of antibodies such as IgG2a. We have also introduced this treatment against cancerous lesions including initial squamous cell and basal cell carcinoma in immunocompetent and immunosuppressed patients. We provide examples of successful treatment of squamous cell cancer using topical imiquimod. CONCLUSION: The available and additional Toll-like receptor agonists will help to improve the specific dermatologic therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents bears potential for effective and patient friendly treatment of inflammatory, infectious, and cancerous skin diseases. Long-term evaluation will define the tolerability and safety profile of these novel topical agents.

Adjuvants, Immunologic↗
PubMed2004

Phototoxicity of exogenous protoporphyrin IX and delta-aminolevulinic acid in the photo hen's egg test.

BACKGROUND: Oxygen, appropriate light sources, and special photosensitizers are necessary to induce photochemical damage in tumor cells via photodynamic therapy (PDT) delta-aminolevulinic acid (ALA) is increasingly used in PDT, because topical or systemic administration of ALA induces accumulation of endogenous porphyrins preferentially in neoplastic tissues. Subsequent radiation with light of approximately 630 nm leads to selective damage of tumor cells. PDT should optimally leave peritumoral tissues unaffected, but only few data are reported on the effects and the time course of ALA-induced porphyrins in tumor-free tissues. METHODS: Therefore, we studied the phototoxic effects of protoporphyrin IX (PP) and ALA-induced porphyrins in a recently established phototoxic model based on tumor-free tissue, the photo hen's egg test (PHET). RESULTS: Employing this test procedure, PP provoked strong phototoxic reactions when irradiated with Ultraviolet A immediately and up to 30 h after substance application. In contrast, ALA induced a significant phototoxic effect only if irradiated 24 h after application. CONCLUSION: Thus, we observed a delayed phototoxic effect of ALA in tumor-free tissue of the yolk sac (YS) blood vessel system. This delayed phototoxic response 24 h after ALA application is probably caused by endogenously synthesized porphyrins. In contrast, epithelial tumors show a maximum porphyrin accumulation 4-8 h after ALA application whereas in healthy human skin porphyrin synthesis is less intensive but prolonged with maximum levels 24-48 h after ALA application. Thus, ALA induced virtually the same delayed phototoxic effect in the tumor-free YS blood vessel tissue as in healthy human skin. These results show that the PHET is a useful model for the predictive preclinical risk assessment of exogenous or endogenous photosensitizers.

Aminolevulinic Acid↗
PubMed2004

Long-term efficacy and safety of pimecrolimus cream 1% in adults with moderate atopic dermatitis.

BACKGROUND: Pimecrolimus cream 1% is a non-steroid, selective inflammatory cytokine inhibitor indicated for atopic dermatitis (AD). OBJECTIVE: To compare the safety and efficacy of pimecrolimus cream 1%-based treatment versus conventional therapy in adults with moderate AD. METHODS: Patients were randomized to receive pimecrolimus cream 1% (n = 62) or vehicle (n = 68) at the first signs/symptoms of AD, for 24 weeks as required. A moderately potent topical corticosteroid (prednicarbate 0.25% cream) was allowed in both groups to treat flares. RESULTS: Corticosteroids were required on fewer days in the pimecrolimus group, compared with the vehicle group (9.7 vs. 37.8%, p < 0.001). Furthermore, 59.7% of pimecrolimus-treated patients experienced no flares during the study period, compared with 22.1% of vehicle-treated patients (p < 0.001). Pimecrolimus cream 1% was well tolerated throughout the study. CONCLUSION: For adults with moderate AD, pimecrolimus cream 1% is well tolerated, reduces the incidence of flares, reduces/eliminates corticosteroid use, improves long-term disease control and enhances the patients' quality of life.

Administration, Cutaneous↗
PubMed2003

Molecular cloning and characterization of alternatively spliced mRNA isoforms from psoriatic skin encoding a novel member of the S100 family.

In an effort to identify psoriasis-associated genes, we compared gene expression in normal and psoriatic skin, using differential display RT-PCR technique. Sequence analysis of a 650-bp cDNA fragment (clone 110) that was highly up-regulated in lesional skin revealed homology to a noncoding cDNA (NICE-2). By subsequent cDNA cloning, using RNA from psoriatic skin, we have identified two alternatively spliced mRNA-isoforms (0.5 and 4.4 kb), which differ in composition of their untranslated regions. By sequence comparison, we have mapped the novel gene, named S100A15, to the S100 gene cluster within the epidermal differentiation complex (chromosome 1q21). Analysis of the deduced amino acid sequence revealed a protein of 101 amino acids containing two potential EF-hand motifs with high homology to the S100A7. Northern blot hybridization and semiquantitative RT-PCR analysis confirmed the S100A15 overexpression in psoriasis, showing different levels of expression of the S100A15 mRNA isoforms. In situ hybridization of the S100A15 revealed a markedly increased staining of basal and suprabasal epidermal layers of psoriatic skin compared with healthy tissue. Our data suggest an involvement of the novel S100A15 in epidermal differentiation and inflammation and might therefore be important for the pathogenesis of psoriasis and other diseases.

Alternative Splicing↗
PubMed2003

Hurpin is a selective inhibitor of lysosomal cathepsin L and protects keratinocytes from ultraviolet-induced apoptosis.

Hurpin (headpin/PI13/serpinB13) is an intracellular, differentially spliced member of the serpin superfamily that has been linked to differentiation and apoptosis of human keratinocytes. It is transiently downregulated by UV light and overexpressed in psoriatic skin lesions. Although it has all of the features of an inhibitory serpin, a productive interaction between hurpin and a proteinase has not yet been reported. Here we demonstrate that hurpin is a potent and selective inhibitor of the archetypal lysosomal cysteine proteinase cathepsin L (catL). Recombinant hurpin inhibits human catL with a stoichiometry of inhibition (SI) of 1.7 and a rate constant k(assoc) of (4.6 +/- 0.14) x 10(5) M(-1) s(-1). It inefficiently inhibits catV and does not inhibit papain, catB, or catK. To investigate the inhibitory mechanism, we determined the P1-P1' bond in the reactive center loop cleaved by catL ((356)Thr-(357)Ser) and expressed variants in which the proximal hinge, P1 residue, or differentially spliced CD loop was mutated. The results of assays using these proteins suggest that inhibition of catL by hurpin occurs via the conventional serpin inhibitory mechanism and that the CD loop plays no role in the process. Finally, it was found that the majority of hurpin is cytosolic and that its overexpression in human keratinocytes confers resistance to UV-induced apoptosis. Given that lysosomal disruption, release of catL, and catL-mediated caspase activation are known to occur in response to cellular stress, we propose that a physiological role of hurpin is to protect epithelial cells from ectopic catL.

Amino Acid Sequence↗
PubMed2003

Molecular basis of basal cell carcinoma: analysis of differential gene expression by differential display PCR and expression array.

Basal cell carcinoma (BCC) is the most common tumor in the Caucasian population. Although BCC rarely metastasize and cause death, they are problematic due to their destructive growth and the frequent localization on the face. Until now the knowledge of genes differentially expressed in BCC has been incomplete. To elucidate the complex alterations in BCC-associated gene expression, we took advantage of 2 techniques: the differential display RT-PCR (DD-PCR) and the differential hybridization of cDNA arrays. Using DD-PCR, we showed differential expression of genes known from other biological contexts (e.g., rac, ubiquitin hydrolase), which could now be associated with BCC. In addition, we detected unknown genes possibly contributing to the carcinogenesis of BCC. Of the 588 genes screened by differential hybridization of the Atlas human cDNA array, differences in the expression levels of BCC were observed for 10 genes. These data were obtained with RNA probes pooled from several BCC of different donors and were subsequently confirmed by semiquantitative RT-PCR for Janus protein tyrosine kinase 3 (Jak3), microsomal glutathione S-transferase 1 (GST 12), teratocarcinoma-derived growth factor cripto, glutaredoxin and the monocyte chemoattractant protein 1 (MCP-1) in 10 individual BCC specimens, 2 squamous cell carcinoma (SCC), the cell line HaCaT and cultured normal human keratinocytes (NHK) in comparison to normal skin. These genes are candidates from gene families with known association to tumors, but they have not been reported in the carcinogenesis of BCC yet. In summary, both approaches allow the detection of differentially expressed genes possibly involved in the carcinogenesis of BCC.

Basal Cell Carcinoma↗