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A Kapp

Publications and source records attributed to A Kapp.

At least 37 records · Page 2Linked to original sources

Distinct amplification of the C5a-receptor pathways in normodense and hypodense eosinophils of patients with atopic dermatitis.

In patients with atopic dermatitis two different types of blood eosinophils with distinct density can be isolated. The normodense cells represent the huge majority in count, whereas the hypodense eosinophils are characterized by higher effector activity. To understand the altered functional responsiveness of these two cell subtypes, the expression of C5a receptors as well as C5a-induced signal pathways and the production of reactive oxygen metabolites have been analyzed. Chemiluminescence measurements revealed significant higher production of reactive oxygen metabolites in hypodense eosinophils in comparison to normodense cells. However, no difference in the expression level of C5a receptors as well as in the C5a-induced Ca2+-transients between normodense and hypodense eosinophils were found. In contrast, hypodense eosinophils showed a significantly higher actin polymerization response and phosphatidylinositol 4,5 bisphosphate 3-kinase activation after stimulation with C5a than normodense eosinophils. Therefore, normodense and hypodense eosinophils from the blood of patients with atopic dermatitis are characterized by differential amplification of C5a-receptor signal pathways, which might explain the differences in their proinflammatory activity.

Actins↗

Detection of mRNA for eotaxin-2 and eotaxin-3 in human dermal fibroblasts and their distinct activation profile on human eosinophils.

As many new biologically active chemokines have been cloned exploring the genomic DNA sequence database in the vicinity of already known chemokine sequences without demonstrating their natural origin, it is important to transfer findings from in vitro experiments with chemokines into the in vivo situation. With respect to eosinophils and fibroblasts that play an important part in the pathogenesis of allergic and autoimmune diseases, the role of the recently discovered members of the eotaxin family, eotaxin-2 and eotaxin-3, is not really understood. In order to elucidate the origin and biologic potency of the eotaxin family this study was performed. Conventional reverse transcription-polymerase chain reaction analysis was suitable to detect mRNA for eotaxin and eotaxin-3 but not for eotaxin-2 in dermal fibroblasts. In contrast to conventional reverse transcription-polymerase chain reaction, LightCycler analysis revealed that dermal fibroblasts constitutively expressed mRNA not only for eotaxin and eotaxin-3 but also for eotaxin-2. Moreover, with this technique we investigated mRNA expression levels after stimulation of fibroblasts with interleukin-4 and interleukin-4 plus tumor necrosis factor-alpha: the rank order of expression levels within the eotaxin family was eotaxin > eotaxin-3 > eotaxin-2. To address the question of the efficacy of eotaxin-3, we compared its activity with eotaxin, eotaxin-2, monocyte chemotactic protein-3, monocyte chemotactic protein-4, and RANTES in different test systems for eosinophils. The efficacy of the CC chemokines at equimolar concentrations with respect to the chemotactic response of human eosinophils was eotaxin-3 = eotaxin = eotaxin-2 > RANTES > monocyte chemotactic protein-4. The rank order of activity with respect to actin polymerization and release of toxic reactive oxygen species was eotaxin-3 = eotaxin = eotaxin-2 and eotaxin = eotaxin-2 > eotaxin-3 = monocyte chemotactic protein-3 = monocyte chemotactic protein-4 = RANTES, respectively. This study indicated a distinct profile in expression levels of the members of the eotaxin family in dermal fibroblasts. Indeed, all three eotaxin ligands demonstrated activation of human eosinophils with similar efficacies for chemotaxis, cytoskeletal rearrangements, activation of Gi proteins and transients of [Ca2+]i, but a distinct profile of activity with respect to the binding to CCR3 and the release of toxic reactive oxygen species. These findings may help to understand further the role of CC chemokines in fibroblast/eosinophil activation, which is of interest particularly in allergic and autoimmune diseases.

Actins↗

Characterization of the CC chemokine receptor 3 on human keratinocytes.

CC chemokine receptors are expressed on hematopoietic cells, and these may impart selective homing of monocyte, leukocyte, and lymphocyte subsets to sites of inflammation. CC chemokine receptor 3 is the major receptor on eosinophils and is also expressed on other inflammatory cells suggesting its important role for allergic diseases such as atopic dermatitis and bronchial asthma. Eotaxin, eotaxin-2 and eotaxin-3 have been identified as ligands that only activate CC chemokine receptor 3. CC chemokine receptor 3 is also activated by other promiscuous ligands, however, such as RANTES and monocyte chemotactic protein 4. To date, CC chemokine receptor 3 has not been reported to be expressed on nonhematopoietic cells. In this study, we investigated whether keratinocytes possess autocrine and paracrine mechanisms for CC chemokine secretion and receptor expression as reported for the expression of interleukin 8 and its receptors. Reverse transcriptase polymerase chain reaction analysis demonstrated that CC chemokine receptor 3 mRNA is expressed constitutively in cultured keratinocytes. The signal quantities of the CC chemokine receptor 3 amplicons showed lower intensities for keratinocytes than for eosinophils. In situ hybridization techniques exhibited that basal cell layers of the epidermis were stained homogeneously for CC chemokine receptor 3 mRNA with a decreasing signal to the upper epidermis showing that differentiating and proliferating keratinocytes did express mRNA specific for CC chemokine receptor 3. Immunohistochemical studies confirmed low expression of CC chemokine receptor 3 protein on epidermal keratinocytes compared to the high level observed on infiltrating eosinophils. Furthermore, stimulation of cultured keratinocytes with eotaxin resulted in an increased [3H]thymidine incorporation indicating a role of CC chemokine receptor 3 in epidermal proliferation and differentiation. These data demonstrate that CC chemokine receptor 3 is expressed not only on hematopoietic cells but also on keratinocytes as nonhematopoietic cells with ectodermal origin. Therefore, the identification of CC chemokine receptor 3 on epidermal keratinocytes may indicate a role for CC chemokine receptor 3 and its ligands in skin physiology and pathophysiology.

Cells, Cultured↗

Detection of clonal T cell receptor gamma gene rearrangements in cutaneous T cell lymphoma by LightCycler-polymerase chain reaction.

Cutaneous T cell lymphoma is thought to be characterized by a monoclonal T cell infiltrate in the skin that can be detected by polymerase chain reaction-based amplification of T cell receptor gamma gene rearrangements. We sought to establish a new, simple, and fast LightCycler-based real-time polymerase chain reaction assay for the detection of monoclonality in cutaneous T cell lymphoma, which was suitable for routine laboratory application. Monoclonal T cell receptor gamma gene rearrangements were detected by polymerase chain reaction with consensus primers using: (i) a thermocycler followed by polyacrylamide gel electrophoresis; (ii) a Light Cycler followed by melting curve analysis; and (iii) a LightCycler and subsequent polyacrylamide gel electrophoresis. The detection limit of monoclonal Jurkat T cells diluted in polyclonal peripheral blood mononuclear cells was: (i) 1--3% by thermocycler--polymerase chain reaction and polyacrylamide gel electrophoresis; (ii) 10% by LightCycler--polymerase chain reaction and melting curve analysis; and (iii) 1% by LightCycler--polymerase chain reaction and polyacrylamide gel electrophoresis. In skin biopsies of 22 cutaneous T cell lymphoma patients, a monoclonal or biclonal T cell infiltrate was detected in: (i) 15 of 22 (68%) by thermocycler--polymerase chain reaction and polyacrylamide gel electrophoresis; (ii) 13 of 22 (59%) by LightCycler--polymerase chain reaction and melting curve analysis; and (iii) 16 of 22 (72%) by LightCycler--polymerase chain reaction and polyacrylamide gel electrophoresis. All three techniques revealed negative results in skin biopsies from 26 patients with benign dermatitis. In conclusion, LightCycler--polymerase chain reaction and melting curve analysis is a fast, simple and specific method to detect monoclonal T cell infiltrates in cutaneous T cell lymphoma. Sensitivity of LightCycler--polymerase chain reaction and polyacrylamide gel electrophoresis is slightly higher compared with sensitivity of thermocycler--polymerase chain reaction and polyacrylamide gel electrophoresis. Melting curve analysis, however, is less sensitive compared with polyacrylamide gel electrophoresis, and in case of negative results of the melting curve analysis, it is recommended to resolve LightCycler--polymerase chain reaction samples by gel electrophoresis.

Adult↗

Levels of circulating CD8(+) T lymphocytes, natural killer cells, and eosinophils increase upon acute psychosocial stress in patients with atopic dermatitis.

BACKGROUND: Different exogenous and endogenous provocation factors such as mental stress are hypothesized as being relevant in the pathophysiology of atopic dermatitis (AD). OBJECTIVE: The purpose of this study was to examine the effects of acute psychological stress on illness-specific immunologic parameters in AD. Patients with psoriasis and healthy volunteers were investigated in parallel. METHODS: Patients with AD (n = 15), patients with psoriasis (n = 15), and control subjects (n = 15) were exposed to mental stress lasting 10 minutes (public speaking, mental arithmetic). In vitro analyses were done 1 hour before, immediately after, and 1 hour after stress exposure. Vital parameters (blood pressure, heart rate) and plasma noradrenaline concentrations were determined to prove the effects of mental stress on the individuals. Lymphocytes were phenotypically analyzed by flow cytometry. RESULTS: The results indicate a higher ability of CD8(+) T lymphocytes to react to stress, including the subpopulations of CD8(+)/CD11b(+) T lymphocytes and eosinophils in patients with AD compared with healthy volunteers. The increases in the subpopulation of CD8(+)/CD11b(+) T lymphocytes on psychological stress were higher in the patients with AD and psoriasis than in healthy control subjects. Significant stress-induced changes of natural killer cells were revealed for all 3 groups. CONCLUSION: The results suggest that psychological stress has different immunologic effects in patients with AD than in patients with psoriasis and healthy men.

Acute Disease↗

Different expression of cytokine and membrane molecules by circulating lymphocytes on acute mental stress in patients with atopic dermatitis in comparison with healthy controls.

BACKGROUND: Mental stress is believed to induce an exacerbation of atopic dermatitis (AD). Until now, however, only few psychoneuroendocrinologic mechanisms underlying the link between psychological stress and exacerbation or maintenance of AD have been described. OBJECTIVE: Our purpose was to conduct an investigation of immunologic parameters in the form of membrane molecules and cytokines with potential relevance for the cutaneous inflammation in an established psychological laboratory stress model. METHODS: Patients with AD (n = 15) and healthy controls (n = 15) were exposed to mental stress, as described in a previous report. In vitro analyses were completed 1 hour before, immediately after, and 1 hour after mental stress exposure. Lymphocyte subpopulations, the cutaneous lymphocyte-associated antigen (CLA), the membrane molecule CD69(+) (early activation antigen), and intracellular IL-4, IL-5, and IFN-gamma in blood-derived lymphocytes were analyzed by flow cytometry. IL-4 in the supernatant of concanavalin-A-stimulated PBMCs was determined by ELISA. RESULTS: An increase in heart rate and blood pressure was demonstrated during psychological stress in patients with AD and healthy volunteers. We found significantly higher stress-induced increase of CLA(+) lymphocytes, T helper cells expressing IL-5, and both CD4(+) and CD8(+) lymphocytes expressing IFN-gamma on mitogenic stimulation in patients with AD in comparison with healthy controls. In addition, we observed an earlier increase in the secretion of IL-4 in the supernatant of mitogen-stimulated lymphocytes during psychological stress in patients with AD in comparison with healthy volunteers. CONCLUSION: A higher stress-induced increase of CLA(+) cells in the circulation in patients with AD compared to healthy controls might indicate an increased ability of T lymphocytes in AD to migrate to the skin during this psychological condition. In addition, the data of this study suggest a different stress-induced cytokine profile in circulating lymphocytes in patients with AD compared to healthy controls.

Adolescent↗

Sensitive detection of Borrelia burgdorferi sensu lato DNA and differentiation of Borrelia species by LightCycler PCR.

In order to differentiate species within the Borrelia burgdorferi sensu lato complex, LightCyler PCR and melting-curve analysis of the amplicons of two genes with intraspecies variability, the p66 gene and the recA gene, were performed. It was demonstrated that nested LightCycler PCR amplification of p66 is more sensitive in the detection of borrelia DNA than amplification of the recA gene. B. burgdorferi sensu stricto could be differentiated from Borrelia garinii and Borrelia afzelii by melting-curve analysis of the p66 gene amplicon. B. garinii could be differentiated from B. afzelii and B. burgdorferi sensu stricto by melting-curve analysis of the recA gene amplicon. Therefore, the PCRs complement each other in subtyping different Borrelia species, and combined LightCycler PCR and melting-curve analysis of both target genes is a rapid method to distinguish the three species of B. burgdorferi sensu lato.

Bacterial Proteins↗

Long term outcome of ocular adnexal lymphoma subtyped according to the REAL classification. Revised European and American Lymphoma.

AIM: To classify ocular adnexal lymphomas according to the Revised European and American Lymphoma (REAL) classification and to determine any correlation between clinical features or histomorphological variables with the patients' outcome. METHODS: Conventional and immunohistology were performed on representative sections of 53 specimens of 46 patients with ocular adnexal lymphoma. The antibodies used were CD20, BCL-2, CD21, CD23, CD43, CD3, CD5, p53, cyclin D1, pan-cytokeratin, kappa, lambda, IgD, and IgM. The growth fraction of the tumours was determined using the MIB-1 antibody directed against the Ki-67 antigen. Clinical follow up data regarding the outcome were obtained from the treating physicians and/or hospital files. The Student's t test and log rank test were used for statistical analysis. RESULTS: The patient collective consisted of 29 females and 17 males with an age range of 32-89.7 years (average 63 years). Almost all specimens represented B cell non-Hodgkin's lymphomas: extranodal marginal zone lymphoma (EMZL) (n=38), diffuse large cell B cell lymphoma (n=8), lymphoplasmocytic lymphoma/immunocytoma (n=2), mantle cell lymphoma (n=2), follicle centre lymphoma (n=1), and plasmacytoma (n=1). One case of a secondary anaplastic large cell lymphoma of T cell type (T-ALCL) was diagnosed. The majority of the patients had stage I disease. A variety of therapeutic regimens was administered, the main form of treatment being radiotherapy. The average follow up time was 85 months. Complete remission was achieved in 24 patients (10 after excision alone, eight after radiotherapy alone, three after combined excision and radiotherapy, one after chemotherapy alone, and two after combined radiotherapy and chemotherapy). 12 patients died of causes related to lymphoma; in one patient the cause of death was unknown. Six patients had persistent tumour at final follow up and two patients were lost to follow up. The stage at presentation, as well as the lymphoma malignancy category, had a significant correlation with the final course of the disease (p=0.0001 and p=0.03, respectively). A significant correlation was also noted between the final outcome (p<0.05) and tumour cell expression for Ki-67 antigen and p53 protein. CONCLUSION: 67% of patients with ocular adnexal lymphoma had EMZL. The stage at presentation had a significant influence on the final outcome. MIB-1 and p53 expression by the tumour cells proved to be important immunohistochemical markers concerning the prognosis. It is suggested that, following thorough staging investigations, primary EMZL (stage I) (if accessible) should be treated with excisional biopsy and subsequent low dose radiotherapy. Primary diffuse large cell B cell lymphoma of the ocular adnexa requires at least similar therapeutic measures and regular intensive follow up.

Adult↗

Pathophysiological role of leukotrienes in dermatological diseases: potential therapeutic implications.

In vitro and in vivo data have demonstrated that leukotrienes play a key role not only in allergic airway diseases but also in inflammatory reactions of the skin. Antileukotriene drugs, i.e. leukotriene receptor antagonists and synthesis inhibitors, are a new class of anti-inflammatory drugs that have shown clinical efficacy in the management of asthma, allergic rhinitis and inflammatory bowel disease. To address the question of the validity and applicability of published evidence of the use of antileukotriene drugs in dermatological diseases, we reviewed data concerning the pathophysiological effect of leukotrienes in the skin and in skin diseases, and the experience with antileukotriene treatment that has been published. In vivo and in vitro data suggest that antileukotriene treatment may have efficacy in atopic dermatitis, different types of urticaria or psoriasis and other skin diseases such as bullous skin diseases, collagenoses, Sjogren-Larsson syndrome or Kawasaki disease. Nevertheless, published evidence is very limited and before any conclusions can be drawn, additional basic research needs to be performed with regard to the role of different leukotrienes and leukotriene receptors in skin diseases. On the basis of these data, randomised and placebo-controlled clinical trials with leukotriene antagonists and synthesis inhibitors should be performed. Moreover, future studies investigating the additive benefit of antileukotriene drugs are warranted, e.g. in combination with antihistamines, corticosteroids or other anti-inflammatory drugs.

Animals↗

Activated human T lymphocytes express a functional C3a receptor.

The C3a molecule is an anaphylatoxin of the C system with a wide spectrum of proinflammatory effects predominantly on cells of myeloid origin. In this study we investigated the expression of the high affinity receptor for C3a (C3aR) in human T lymphocytes using receptor-specific mAb. C3aR expression was detected in CD4(+) and CD8(+) blood- or skin-derived T cell clones (TCC) from birch pollen-sensitized patients with atopic dermatitis. No significant difference in C3aR expression in CD4(+) or CD8(+) TCCs could be observed. In contrast to C3a(desArg), C3a led to a transient calcium flux in TCCs expressing the C3aR, whereas C3aR-negative TCCs were unreactive. Circulating T cells from patients suffering from severe inflammatory skin diseases expressed the C3aR, whereas no expression of C3aR could be found in unstimulated T lymphocytes from patients with mild inflammatory skin diseases or from healthy individuals. Type I IFNs, which are potent stimulators of cellular immunity, were identified as up-regulators of C3aR expression in vitro in freshly isolated or cloned T lymphocytes. Moreover, C3aR(+) T cells were found at the sites of injection in IFN-beta-treated patients with multiple sclerosis. These data provide direct evidence for the expression of C3aR on activated human T lymphocytes; this may point to a biological function of C3a in T cell-dependent diseases.

Antibodies, Monoclonal↗

Characterization of synthetic C3a analog peptides on human eosinophils in comparison to the native complement component C3a.

The C3a anaphylatoxin is a potent proinflammatory mediator derived from the complement system inducing biologic effects of human eosinophils like Ca2+ transients and the activation of the respiratory burst. These findings support an important role for C3a in diseases typically associated with a peripheral blood or tissue eosinophilia. Synthetic human C3a analogue peptides with variations at the C-terminal effector domain have been evaluated with respect to their binding affinity and signaling potency on human eosinophils. Flow cytometrical analysis and RT-PCR revealed that the C3a receptor is constitutively expressed on human eosinophils. Peptides bearing an N-terminal 9-fluorenylmethoxycarbonyl and the 6-aminohexanoyl motif were the most powerful peptides tested. Amino acid replacements in the conserved C-terminal pentapeptide decreased binding affinity and functional potency substantially. In addition, synthetic C3a analogue peptides induced C3aR internalization, led to transient changes of intracellular Ca2+ concentration, and did release reactive oxygen species in human eosinophils indicating the in vivo relevance of C3a-related sequences. The tripeptide LAR was found to be essential for C3a receptor binding on human eosinophils. Moreover, the putative binding motif of C3a anaphylatoxin is also crucial for the induction of biologic effects in the human system such as changes of intracellular Ca2+ concentration and the release of reactive oxygen species. This study demonstrates that the carboxyl terminus is important for the interaction with the C3aR and the biologic potency of C3a anaphylatoxin in the human system and plays a key role in the activation process of human eosinophils.

Calcium↗

Differential activation of CC chemokine receptors by AOP-RANTES.

RANTES (regulated on activation normal T cell expressed) has been found at elevated levels in biological fluids from patients with a wide range of allergic and autoimmune diseases and is able to attract several subtypes of leukocytes including eosinophils and monocytes into inflamed tissue. Amino-terminal modifications of RANTES produce receptor antagonists which are candidates for blocking this cellular recruitment. Met-RANTES has been shown to modulate inflammation in vivo, while AOP-RANTES is a potent inhibitor of R5 human immunodeficiency virus type 1 (HIV-1) strains and has been shown to down-modulate CCR5 and prevent recycling of the receptor. We have studied the effect of AOP-RANTES in eosinophil activation and have found that it is able to efficiently elicit eosinophil effector functions through CCR3, as measured by the release of reactive oxygen species and calcium mobilization, whereas Met-RANTES is inactive in these assays. AOP-RANTES is found to inhibit CCR3-mediated HIV-1 infection with moderate potency, in contrast to its potent inhibition of CCR5-mediated HIV-1 infection. Furthermore, we have investigated the abilities of these modified proteins to down-modulate CCR1 and CCR3 from the surface of monocytes and eosinophils. We show here that AOP-RANTES is much less effective than RANTES in down-modulation of CCR1. Surprisingly, recycling of CCR1 was minimal after incubation with RANTES while there was complete recycling with AOP-RANTES. In the case of CCR3, no significant difference was found between RANTES and AOP-RANTES in down-modulation and recycling. It therefore appears that trafficking of RANTES receptors follows different patterns, which opens up potential new targets for therapeutic intervention.

Anti-HIV Agents↗

[Malignant melanoma of the skin. Pathogenesis, clinical aspects and prognosis].

Cutaneous malignant melanoma is not among the most frequent cancer types at an incidence of 10-12/100,000 persons/year in Central Europe. However, the number of melanomas has doubled within the last 10-15 years. This increase is higher than that of most other malignancies. It has been attributed to an increased UV-light exposure, whereby the latency period probably reaches decades. Persons at high risk for melanoma were identified in various studies: those from families with other melanoma patients and those who have more than 50 benign nevi, atypical nevi and actinic freckles. The majority of melanomas develops de novo and not from preexisting nevi. Treatment of choice is complete surgical excision of the tumors. Prognosis of these patients is mainly determined by tumor thickness. Metastatic spread occurs most frequently within lymph vessels, local recurrences as well as regional metastases significantly impairing the prognosis. From long-term experience in Australia it is evident that the dilemma "melanoma" can only be addressed effectively by rigorous prophylaxis and early diagnosis of the tumors.

Adolescent↗

Safety and efficacy of 1 year of tacrolimus ointment monotherapy in adults with atopic dermatitis. The European Tacrolimus Ointment Study Group.

OBJECTIVE: To investigate the safety and efficacy of using 0.1% tacrolimus ointment for long-term treatment of atopic dermatitis. DESIGN: Open-label, noncomparative study with 6 to 12 months of follow-up. SETTINGS: Outpatient departments in 30 study centers in 11 European countries. PATIENTS: We enrolled 316 patients aged 18 years and older with moderate to severe atopic dermatitis, 200 for 6 months and 116 for 12 months; 77.5% of patients completed the study. INTERVENTION: Twice-daily application of 0.1% tacrolimus ointment on all affected skin. Visits were scheduled on day 1; after 1, 2, and 4 weeks of treatment; and monthly thereafter. MAIN OUTCOME MEASURES: Safety assessments included monitoring of adverse events, clinical laboratory values, and tacrolimus blood concentrations. Efficacy end points included a combined score (modified Eczema Area and Severity Index) and an investigator's global assessment. RESULTS: Local irritation, adverse events such as burning sensation (47% of patients), pruritus (24% of patients), and erythema (12% of patients) were common but tended to occur only when initiating treatment. Laboratory values showed no marked changes over time. Systemic absorption was minimal, with the maximum tacrolimus blood concentration being less than 1 ng/mL in 76% of patients. All efficacy end points showed improvement. The mean (SD) modified Eczema Area and Severity Index score was 23.7 (12.6) at day 1, 13.5 (11.3) at week 1, 6.1 (9.2) at month 6, and 6.1 (8.1) at month 12. Marked or excellent improvement or clearance of disease was reported in 54%, 81%, and 86% of patients at week 1, month 6, and month 12, respectively. CONCLUSION: Up to 1 year of tacrolimus ointment use was safe and effective in patients with atopic dermatitis. Arch Dermatol. 2000;136:999-1006

Administration, Topical↗

The CC chemokine receptor 3 CCR3 is functionally expressed on eosinophils but not on neutrophils.

The chemokine subclasses differ in their biological activity to stimulate different kinds of effector cells via distinct chemokine receptors. Controversial results about the expression of the CC chemokine receptor CCR3 on the surface of human neutrophils have been described. To find out whether eosinophil contamination might be responsible for these diverse observations, CCR3 expression on highly purified neutrophils and eosinophils was investigated. We enriched neutrophils from a heterogeneous granulocyte population with immunomagnetic beads coated with various anti-CD52 monoclonal antibodies. This procedure was suitable to enrich neutrophils with a purity of up to 99.85%. Reverse transcriptase-PCR revealed that CCR3 mRNA was not expressed by CD52-negative selected neutrophils. In contrast to these cells, CCR3 mRNA could be detected in a heterogeneous granulocyte population and CD16-negative selected eosinophils. In addition, spectrofluorometric measurement of intracellular calcium concentration ([Ca2+]i) demonstrated that CD52-negative selected neutrophils did not show a transient [Ca2+]i increase following stimulation with the CCR3 ligand eotaxin, whereas the heterogeneous granulocyte population as well as eosinophils did respond. Therefore, previous studies demonstrating the expression of CCR3 on human neutrophils have to be re-evaluated because CCR3 mRNA detection on human neutrophils due to contamination by mRNA from eosinophils could not be excluded.

Adult↗

[Trigeminotrophic ulceration of the ala nasi in Wallenberg syndrome].

A patient developed a trophic ulceration of the nose after an acute bulbar ischemia with infarction of the right trigeminal nuclei. Neurologic examination showed symptoms of a Wallenberg syndrome including ipsilateral hyp- and paresthesia of the second trigeminal branch and disturbed sensibility and temperature sense on the contralateral half of the body. The right ala nasi showed the characteristic sickle-shaped defect (ulcération en arc). The differential diagnosis and therapeutic approaches are discussed.

Aged↗

Allelic loss at the neurofibromatosis type 1 (NF1) gene locus is frequent in desmoplastic neurotropic melanoma.

Mutations of the tumour-suppressor gene NF1 (neurofibromatosis 1) have been observed in neurofibromas and neurofibrosarcomas of patients with von Recklinghausen's disease and in sporadic nerve sheath tumours. In contrast, melanoma, another tumour type of neuroectodermal origin, rarely shows NF1 alterations. Desmoplastic neurotropic melanoma (DNM) is an uncommon melanoma subtype that shares morphological characteristics with nerve sheath tumours. Therefore, we analysed 15 DNM and 20 melanomas without morphological features of desmoplasia or neuroid differentiation (common melanomas) for loss of heterozygosity (LOH) at the NF1 locus and flanking regions. Allelic loss was detected in 10/15 (67%) DNM but only in 1/20 (5%) common melanomas. LOH was most frequently observed at marker IVS38, located in intron 38 of NF1. These data suggest a role for NF1 in the pathogenesis of DNM and support an earlier hypothesis that exon 37 might encode a functional domain. DNM may represent an interesting tumour model tor the further elucidation of the cellular functions and tumour-suppressive potential of neurofibromin.

Alleles↗