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Biomedical subjects

J Elsner

Publications and source records attributed to J Elsner.

At least 19 recordsLinked to original sources
PubMed2001

[Hereditary C1 esterase inhibitor deficiency type I. Divergence of clinical symptoms and laboratory chemical findings].

A 35- and a 29-year-old woman presented with longstanding recurrent angioedema refractory to therapy with steroids and antihistaminic drugs. Laboratory data revealed in both cases a functional and immunohistochemical deficiency of C1-esterase-inhibitor protein (C1-INH). Further investigations of their families showed some individuals with the same pathological findings without any clinical symptoms. Thus we identified striking differences in degree of severity of clinical features in hereditary C1-INH-deficiency type I. These case-reports emphasize the importance of knowing further diagnostic steps in angioedema refractory to therapy with steroids and antihistamines drugs. Furthermore we give a picture of the different clinical courses of C1-INH-deficiency type I and underline that there is no correlation between clinical symptoms and laboratory findings.

Adult↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2001

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

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↗
PubMed2000

Coronary vascular stunning in bypass operations during reperfusion and treatment with nitroglycerin.

OBJECTIVE: A compromised blood flow after ischemia and reperfusion caused by an increased coronary artery resistance can additionally jeopardize the recovery of myocytes. During routine bypass operations, we investigated the effect of various nitroglycerin doses on elevated coronary resistance before and after ischemia and after a defined reperfusion period. METHODS: 46 patients with a low-risk profile scheduled for routine coronary artery bypass grafting were investigated. During normothermic total extracorporeal circulation, the completely relieved and fibrillating heart was completely isolated from the systemic circulation and the coronary artery system was perfused at 300 ml/min and flow-controlled. The perfusion pressures were monitored continuously. This protocol was performed at three time points: I. Control (ctr) = 10 minutes after institution of extracorporeal circulation, II. Early reperfusion (early rep) = immediately after an myocardial ischemia of 46 +/- 8 minutes, and III. Late reperfusion (late rep) = after a reperfusion period of 25 +/- 4.5 minutes. In 12 randomly chosen patients in a second step, 3 microg per kg heart weight per min of nitroglycerin (low-dose NTG) was added to the perfusate at time points I and III. In another 12 patients, we applied a bolus injection of 2 mg into the aortic root instead of low-dose NTG. RESULTS: Compared to ctr, vascular resistance had decreased at early rep by 17% (0 - 48%) (p < 0.005). At late rep, resistance had increased by 46% (5 - 94%) (p < 0.001) compared to early rep and by 23% (3 - 36%) (p < 0.005) compared to ctr. Resistances had risen in particular in patients with hypertension. Application of low-dose NTG lowered resistances by 5% (0-8%) (non-significant) at ctr, and by 6% (0 - 11%) (non-significant) at late rep. Bolus NTG decreased resistances at ctr by 11% (2 - 21%) (p < 0.05) and at late rep by 21% (6 - 48%) (p < 0.01). CONCLUSIONS: In routine heart surgery, coronary vascular constriction is regularly present during postischemic reperfusion despite myocardial protection measures. NTG abolishes this coronary vascular stunning only in part if systemically applicable dosages are given. High-dose intracoronary application of NTG relieves the coronary vasoconstriction completely, but the dosages needed cannot be applied systemically. In this study, vasoconstriction after reperfusion was markedly increased in patients with hypertension.

Aged↗
PubMed1999

The biologic role of interleukin-8: functional analysis and expression of CXCR1 and CXCR2 on human eosinophils.

Chemokines play an important role in attracting granulocytes into sites of inflammation. Two chemokine subfamilies differ in their biologic activity for different granulocyte subsets. Whereas CXC chemokines such as interleukin-8 (IL-8) activate predominantly neutrophils, CC chemokines such as RANTES and eotaxin activate predominantly eosinophils. However, controversial results have been published in the past regarding the biologic role of IL-8 in eosinophil activation, particularly in allergic diseases. In this study, we investigated the functional evidence and expression of both IL-8 receptors, CXCR1 and CXCR2, on highly purified human eosinophils. In the first set of experiments, a chemotaxis assay was performed showing that IL-8 did not induce chemotaxis of eosinophils. In addition, and in contrast to neutrophils and lymphocytes, IL-8 did not induce a rapid and transient release of cytosolic free Ca2+ ([Ca2+]i) in eosinophils, even after preincubation with TH1- and TH2-like cytokines. To investigate whether neutrophil contamination might be responsible for the reported IL-8 effects on eosinophils, neutrophils were added to highly purified eosinophils from the same donor in different concentrations. Interestingly, as little as 5% of neutrophil contamination was sufficient to induce an increase of [Ca2+]i after stimulation with IL-8. Flow cytometry experiments with monoclonal antibodies against both IL-8 receptors demonstrated no expression of CXCR1 and CXCR2 on eosinophils before or after cytokine activation. Reverse transcriptase-polymerase chain reaction experiments showed that eosinophils, in contrast to neutrophils and lymphocytes, did not express mRNA for CXCR1 and CXCR2. In summary, this study clearly demonstrates that CXCR1 and CXCR2 are not expressed on human eosinophils, even after priming with different bioactive cytokines. Because the CXC chemokine IL-8 did not induce in vitro effects on human eosinophils, IL-8 may also not contribute in vivo to the influx of eosinophil granulocytes into sites of allergic inflammation. Our results suggest that CC chemokines such as eotaxin, eotaxin-2, and MCP-4 are predominant for the activation of eosinophils.

Antibodies, Monoclonal↗
PubMed1999

[Hyperthermia-induced priming effect in neutrophil granulocytes].

BACKGROUND AND OBJECTIVE: Whole-body infrared-A irradiation (WBIAI) according to Ardenne is a newly developed version of hyperthermia. In clinical use benefits for patients with chronic infections have been reported. In order to find out more about the immunological background of the method we studied the question whether hyperthermia leads to priming effects in human polymorphonuclear leukocytes (PMN). MATERIAL AND METHODS: We therefore investigated the production of reactive oxygen radical species (ROS) measured by lucigenin-dependent chemiluminescence after stimulation with N-formylpeptide (FMLP, 10(-6) and 10(-7) M), C5a complement (10(-7) and 10(-8) M) or phorbolester (PMA, 10(-7) and 10(-8) M) in isolated PMN of 8 volunteers undergoding a 60-min hyperthermia treatment with the WBIAI. Blood was drawn 0/60/240/510 min after the start of hyperthermia treatment. In addition, we measured blood pressure, pulse, and temperature. RESULTS: In 5 cases a significant increase in ROS (p < 0.05) could be measured beginning 240 min after start of hyperthermia and further increasing until the 510-min time point. These results suggest a priming effect in PMN lasting far beyond the actual treatment period. The increase of ROS production following stimulation with FMLP, C5a or PMA was 60.4 +/- 21.6, 86.0 +/- 23.3, and 63.3 +/- 15.9% (SEM), respectively. Moreover, in all probands the maximal ROS production in PMN was observed 510 min after the beginning of WBIAI treatment. In 3 cases no difference in ROS could be observed. There was no difference in temperature, blood pressure, and pulse between responders and nonresponders. CONCLUSIONS: Our results show a hyperthermia-dependent priming effect of ROS production in PMN, suggesting an increase in immune reaction within the observation period of 510 min. Further investigations are necessary in order to specify responders and nonresponders and to characterize the results in specific diseases and the constitutions of the patients.

Complement C5a↗