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Biomedical subjects

E Christophers

Publications and source records attributed to E Christophers.

At least 73 records · Page 4Linked to original sources
PubMed1999

Determination of 5-S-cysteinyldopa in plasma and urine using a fully automated solid-phase extraction--high-performance liquid chromatographic method for an improvement of specificity and sensitivity of this prognostic marker of malignant melanoma.

5-S-Cysteinyldopa (5-SCD) in plasma and urine was determined by means of a newly developed method. This method incorporates optimized conditions for blood collection and storage, as well as a new extraction and separation technique, required for the strong oxidation and light sensitive 5-SCD. The new aspects of the method are the following: immediate centrifugation and freezing of the samples after blood collection, fully automatical solid-phase extraction (SPE) with phenylboronic acid (PBA) cartridges and immediate HPLC injection of the eluate, nearly complete exclusion of light and air-oxygen during extraction, constant sample cooling, use of the more suitable internal standard 5-S-D-cysteinyldopa and easy, sensitive and selective HPLC conditions (RP18-column with isocratic separation and electrochemical detection). The method has a linear range from 0.25 to 50 microg l(-1) and 25 to 5000 microg l(-1) for plasma and urine samples, respectively, a limit of detection of 0.17 microg l(-1), intra-assay variabilities from 1.7 to 3.6%, inter-assay variabilities from 4.0 to 18.3% and an average relative recovery of 103.5% for plasma and 105.4% for urine samples. In our study the measured 5-SCD concentrations of patients with melanomas at various stages correlated better with their clinical pictures than described in literature up to date. The results were obtained in comparison to patients with other skin tumors and in comparison to healthy control persons.

Automation↗
PubMed1999

Genomic organization, sequence analysis and transcriptional regulation of the human MCP-4 chemokine gene (SCYA13) in dermal fibroblasts: a comparison to other eosinophilic beta-chemokines.

The eosinophil chemotactic beta-chemokine MCP-4 is assumed to be involved in the accumulation of eosinophils characteristic for eosinophilic inflammatory diseases. We here describe the genomic organisation (3 exons of 138, 115 and 578 bp, 2 introns of 867 and 437 bp and 1.4 kb of regulatory sequences from the immediate 5' upstream region), sequence (genomic and transcribed) and mRNA expression of the human MCP-4 gene in dermal fibroblasts. Among the promoter elements potentially regulating MCP-4 gene expression and/or mediating the effects of anti-inflammatory drugs we identified consensus sequences known to interact with nuclear factors like NF-IL6, AP-2, a NF-kappaB like consensus sequence, gamma-interferon- response and YY-1 elements as well as glucocorticoid response elements. Like MCP-3, MCP-4 mRNA expression in dermal fibroblasts is upregulated by TNF-alpha, IL-1alpha, IFN-gamma or IL-4 and differs from RANTES and eotaxin mRNA expression in its response to IFN-gamma and/or IL-4.

5' Untranslated Regions↗
PubMed1999

Linkage disequilibrium analysis of familial psoriasis: identification of multiple disease-associated MHC haplotypes.

Although psoriasis vulgaris (PsV) is strongly associated with certain human leukocyte antigens, the pathogenetic nature of these associations remains elusive. The objectives of this study were: (i) to determine whether HLA loci directly determine susceptibility or merely serve as markers for the susceptibility allele; and (ii) to identify additional disease-associated haplotypes. By applying maximum likelihood linkage disequilibrium analysis (LDA) in cases vs. controls, we found the susceptibility gene to be more strongly associated with specific HLA haplotypes than with their component alleles. Stronger linkage disequilibrium between PsV and HLA alleles was detected at HLA-C and HLA-B than at DRB1 and DQB1. Parametric linkage analysis accounting for marker-trait disequilibrium in psoriasis vulgaris pedigrees yielded most significant results for a locus close to HLA-B and -C. Furthermore, we found that susceptibility is linked to at least three different ancestral HLA haplotypes; among them, HLA-Cw7-B8-DRB1*0301-DQB1*02 is linked to PsV for the first time. These results identify a major PsV susceptibility locus in the immediate vicinity of, but distinct from HLA-B or HLA-C, and suggest that multiple disease alleles have arisen during human evolution.

Alleles↗
PubMed1999

Corneodesmosin gene polymorphism demonstrates strong linkage disequilibrium with HLA and association with psoriasis vulgaris.

Corneodesmosin (CD) is thought to play a key role in corneocyte cohesion, and its proteolysis appears to be a major event in the process of desquamation. Recently it was shown that CD is encoded by the S-gene, which is located approximately 160 kb telomeric of HLA-C. In the present study, the role of CD in the genetics of psoriasis vulgaris was studied in greater detail. The second exon of the CD gene was sequenced in 86 HLA-typed individuals from 13 psoriasis multiplex families. A total of 11 silent dimorphisms and 7 variants resulting in amino acid substitutions were found. Pedigree analysis showed that these variants could be grouped into 7 alleles, encoding 6 different amino acid sequences. These alleles are in strong linkage disequilibrium with HLA-B and -C, indicating that the polymorphism of the CD gene is ancient and well conserved rather than sporadic. One allele at the CD locus, designated CD2, displayed strong linkage disequilibrium with HLA-Cw6, the HLA allele most prominently associated with psoriasis. CD2 demonstrated a greater relative risk than Cw6 (3.4 vs. 2.5, not significant) and higher significant transmission disequilibrium with psoriasis than any of the investigated HLA-alleles. Due to its biologic function, cellular location and disease association, the CD gene appears to be an excellent candidate gene for PSORS1, the HLA-linked determinant of psoriasis vulgaris.

Alleles↗
PubMed1999

Linear IgA disease associated with lymphocytic colitis.

A 66-year-old woman presented with a bullous skin eruption and chronic diarrhoea. Lesional skin showed subepidermal blistering, and direct immunofluorescence of perilesional skin revealed linear deposits of IgA at the dermoepidermal junction, establishing a diagnosis of linear IgA disease (LAD). Chronic watery diarrhoea complicated by substantial loss of body weight preceded the skin eruption for several months. On endoscopy, the colon appeared macroscopically normal. On histology, the colon mucosa showed increased numbers of intraepithelial lymphocytes and infiltrates of mononuclear cells in the lamina propria, indicative of lymphocytic colitis. Treatment with methylprednisolone and dapsone led to complete clearing of the bullous skin eruption and marked improvement of the patient's diarrhoea. Gastrointestinal disorders such as lymphocytic colitis have rarely been reported in patients with LAD. Whether the simultaneous occurrence of these two diseases is coincidental or due to related pathogenetic mechanisms remains to be seen.

Aged↗
PubMed1999

Comèl-Netherton syndrome complicated by papillomatous skin lesions containing human papillomaviruses 51 and 52 and plane warts containing human papillomavirus 16.

We describe a 28-year-old woman with characteristic clinical signs of Comèl-Netherton syndrome (CNS) who showed numerous plane warts on her face and forearms and papillomatous skin tumours affecting her groins and genitoanal skin. Using human papillomavirus (HPV) type-specific primers for cutaneous and mucosal HPV types we identified HPV 16-specific sequences in plane warts and HPV 51- and HPV 52-specific DNA in papillomatous skin from the patient's groins, suggesting a pathogenetic role (cofactor) for HPV in the development of verrucous skin lesions in patients with CNS. Whether the susceptibility to HPV infections is due to decreased cellular immunity or epidermal defence mechanisms remains to be seen.

Adult↗
PubMed1999

Predictive value of serum S100B for monitoring patients with metastatic melanoma during chemotherapy and/or immunotherapy.

In the immunohistology of malignant melanoma the use of polyclonal antibodies against protein S100 is well established. Recently, it was shown that S100B, a subunit of the S100 protein family, is detectable in the serum of melanoma patients and correlates with the stage of the disease in patients with metastatic melanoma. In the present study, the first evaluation of a large number of treatment observations (n = 77) in 64 different patients during chemotherapy and/or immunotherapy for advanced metastatic melanoma (stage IV) is presented. All patients received treatment according to standardized protocols comprising 8 weeks of treatment followed by routine staging procedures to evaluate therapeutic outcome. In 13 patients with tumour enlargement after first-line therapy, a second-line treatment was subsequently given. S100B immunoradiometric assay (IRMA) tests were performed before, during and after treatment at scheduled time points. In the interim analysis at 4 weeks 29 of 37 (78%) patients with tumour progression during treatment showed a raised S100B level. In the final analysis at 8 weeks, 31 of these 37 patients (84%) demonstrated rising S100B values (P < 0.001). Patients who responded to treatment (stable or regressing metastatic disease) showed constant or declining S100B levels in 38 of 40 patients (95%) at the interim analysis, at 8 weeks this was further increased to 39 of 40 patients (98%; P < 0.001). Thus, the use of S100B for monitoring treatment is adequate in the majority of cases. Our observations are of great interest for therapeutic trials of adjuvant and palliative therapies as the rise of S100B levels might indicate that re-staging and/or changes in therapy strategies should be chosen.

Adult↗
PubMed1999

Treatment of severe psoriasis with fumaric acid esters: scientific background and guidelines for therapeutic use. The German Fumaric Acid Ester Consensus Conference.

Fumaric acid ester (FAE) therapy has proved to be safe and effective in patients with severe psoriasis vulgaris. This treatment was introduced nearly 30 years ago, but is only now gaining renewed interest among dermatologists. FAE therapy is licensed in Germany and registration is pending in many European countries. Multicentre trials have confirmed the beneficial effect of FAE in psoriasis and have defined the spectrum of its adverse effects. Although the mode of action of FAEs in the treatment of psoriasis is not fully understood, recent experimental data point towards a skewing of the Th1-dominated T-cell response in psoriasis to a Th2-like pattern, and inhibition of proliferation of keratinocytes. This article reviews the experimental and clinical information on FAEs in psoriasis and provides guidelines for the clinical use of FAEs derived from a consensus meeting of leading experts.

Cytokines↗
PubMed1999

Interleukin-8 plays its role at local level in psoriasis vulgaris.

The pro-inflammatory properties of interleukin-8 (IL-8) suggest a major role of this peptide in inflammatory processes of skin and other organs. Both biochemical and immunohistochemical studies from our group have demonstrated IL-8 peptide within psoriatic scales and epidermis. So far, however, the relevance of circulating IL-8 and its relation to locally produced IL-8 in this disease remain unclear. Serum IL-8 levels of psoriatic patients were determined in sandwich-ELISA prior to therapy as well as during therapy. Using either the assay from our laboratory or three commercial ELISAs, no correlation was found between serum IL-8 levels and disease severity at any stage of the disease. Similarly, epidermal IL-8-immunoreactivity was monitored immunohistochemically in sequential biopsies from individual psoriatic lesions as they resolved during the course of therapy. Initially, decreased epidermal IL-8 immunoreactivity shifted to a homogeneous staining comparable to normal or non-diseased skin as lesions resolved under treatment. These results indicate a role of IL-8 at local level in psoriatic skin. In contrast to hyperinflammatory diseases like sepsis, where increased serum IL-8 levels are found, in psoriasis either circulating IL-8 is absent or potent mechanisms are operative effectively binding and/or inactivating IL-8 as it enters circulation.

Biopsy↗
PubMed1999

Prognostic significance of serum S100B detection compared with routine blood parameters in advanced metastatic melanoma patients.

Recent reports on the use of a quantitative measurement of S100B protein for the detection of metastatic melanoma have yielded promising results. In this study we evaluated 489 serum samples from 64 patients suffering from advanced melanoma (UICC/AJCC stage IV) to compare the sensitivity of a S100B immunoradiometric assay (IRMA) with that of conventional blood parameters as well as other known clinical prognostic factors. In a univariate statistical analysis, gender, bone metastasis, and lactate dehydrogenase and S100B levels in serum samples were found to be significant prognostic markers (P<0.05). The S100B level represented the only relevant independent prognostic marker that was sustained in a multivariate analysis (P = 0.016). Furthermore, we were able to demonstrate that S100B is of relevance irrespective of the specific sites of metastatic involvement. The other laboratory parameters could not match the sensitivity rate of S100B. Overall survival rate was strongly associated with serum S100B values. The results of our study suggest that S100B might be a useful tool as a melanoma marker and an independent prognostic factor in advanced metastatic melanoma. S100B serum detection is likely to be of great interest for the pretreatment stratification and/or monitoring of patients enrolled in clinical studies.

Blood Platelets↗
PubMed1999

S100B protein detection in serum is a significant prognostic factor in metastatic melanoma.

The serum detection of S100B, a new melanoma marker, has shown clinical significance in early studies. The aim of our study of 1, 339 serum samples from 412 different melanoma patients and 107 control patients was to prove the prognostic value of serum S100B levels in melanoma patients at different stages of disease and at follow-up (median: 30 months). Using a cutoff level of 0.2 microgram/l S100B, 5 of 286 patients (1.7%) with primary tumors (stage I/II), 14/73 (19.2%) patients with locoregional metastasis (stage III) and 57/84 (67.9%) patients with advanced disease (stage IV) were S100B positive (statistically significant differences for stage I/II vs. III, I/II vs. IV, and III vs. IV, p < 0.001). The estimated overall survival time was significantly longer (p < 0.001) for patients with S100B values below 0.2 microgram/l compared to patients with elevated S100B levels (>/=0.2 microgram/l), which was independent of the stage of disease (I-IV). Regarding prognosis, we were furthermore able to distinguish different subgroups among stage III and IV patients using S100B serum levels (p < 0.01). Patients with different cutaneous non-melanoma diseases served as S100B-negative controls. S100B serum evaluations using the Sangtec(R)100 IRMA are highly specific and sensitive for the detection of metastatic melanoma. S100B has been shown to be a relevant prognostic factor for survival in a study with a large sample size of melanoma patients including close follow-up evaluations.

Adult↗
PubMed1999

Identification of DNA sequences of both genital and cutaneous HPV types in a small number of keratoacanthomas of nonimmunosuppressed patients.

BACKGROUND: Viral infection was suggested to be etiologically involved in skin tumor development. Data on the association of human papillomavirus (HPV) with keratoacanthomas are still conflicting. OBJECTIVE: Analysis of HPV infection in keratoacanthomas of the general population. METHODS: HPV DNA was detected by nested PCR. To include a broad range of both cutaneous and mucosal HPV types, HPV PCR was performed with two sets of degenerate primers. RESULTS: Considering only beta-globin-positive specimens, HPV DNA was detected in 20% of the specimens obtained from 18% of the patients. The spectrum of HPV types detected contains HPV types 6, 14, 16, 35, 58 and 61. In 1 case, the underlying HPV type was not identified. In 1 specimen with transition towards squamous-cell carcinoma, HPV 16 was detected. CONCLUSIONS: HPV is probably not generally associated with the etiology of keratoacanthoma but may be relevant in individual cases. Oncogenic HPV types may be cofactors for malignant transformation of initially benign skin lesions like keratoacanthomas.

DNA, Viral↗
PubMed1999

IL-4 induces eotaxin in human dermal fibroblasts.

A common feature of Th2-mediated skin diseases is selective eosinophil (Eo) infiltration in the affected dermis. However, the mechanisms of selective Eo recruitment are not yet fully understood. Our recent findings indicated that dermal fibroblasts actively participate in the accumulation of Eo in Th2-mediated skin inflammation. Following stimulation with IL-4, dermal fibroblasts produce eotaxin, which is the only biologically active Eo attractant detected in the supernatants. Natural eotaxin is comprised of a mixture of N-terminal-truncated and O-glycosylated variants. The expression of eotaxin mRNA is upregulated within 1 h after stimulation. TNF-alpha markedly enhances eotaxin mRNA expression and release of the protein product from IL-4-stimulated fibroblasts. As mast cells and Th2 cells produce both cytokines, it is probable that Eo recruitment into sites of allergen-induced, Th2-mediated skin reactions is, at least in part, due to IL-4-stimulated induction of eotaxin in dermal fibroblasts.

Chemokine CCL11↗
PubMed1999

Association of lymphocytic colitis with linear IgA dermatosis.

The case of a 66-year-old female patient is presented, who suffered from chronic watery diarrhea. In addition, she developed linear IgA dermatosis after oral treatment of a presumed yeast infection with nystatin. To evaluate the reason for her diarrhea, colonoscopy was performed. The macroscopic aspect of the colon mucosa was described as normal with no specific alterations for chronic inflammatory bowel disease or for bacterial infections. In contrast, the histologic examination revealed the typical characteristics of lymphocytic colitis. This disease is thought to be caused by immunological reactions against as yet unknown luminal antigens. After treatment with steroids and dapsone the diarrhea as well as the skin disease disappeared. To our knowledge, the present report describes for the first time the association of linear IgA dermatosis with lymphocytic colitis after oral treatment with nystatin. A possible causative link between these two disease entities is discussed.

Administration, Oral↗
PubMed1998

Antileukoprotease in human skin: an antibiotic peptide constitutively produced by keratinocytes.

Antileukoprotease (ALP), also known as mucous protease inhibitor or secretory leukoprotease inhibitor, resembles one of the major antiproteases present in human body fluids. It is capable of preventing proteolytic degradation of extracellular matrix proteins by neutrophil-derived serine proteases. ALP was isolated from human callus and detected in supernatants of cultured human primary keratinocytes. ALP mRNA was constitutively expressed in keratinocytes and the expression was not significantly affected by TNF alpha or Interferon gamma stimulation. In microbicidal assays recombinant ALP exhibited antimicrobial activity against several human skin associated microorganisms like P. aeruginosa, S. aureus, S. epidermidis, and C. albicans, indicating that ALP may actively participate in mechanisms allowing homeostasis of bacterial and yeast colonization on human skin. Thus, ALP represents a major soluble serine protease inhibitor and antimicrobial agent expressed in human skin and seems to contribute to the high resistance of the epidermis against proteolysis and infections.

Anti-Bacterial Agents↗