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At least 325 records · Page 18Linked to original sources
PubMed1988

Platelet-activating factor induces eosinophil peroxidase release from purified human eosinophils.

The degranulation response of purified human eosinophils to platelet-activating factor (PAF) has been studied. PAF induced release of eosinophil peroxidase (EPO) and beta-glucuronidase from highly purified human eosinophils with an EC50 of 0.9 nM. The order of release was comparable with that induced by phorbol myristate acetate (PMA). The new specific PAF antagonist 3-[4-(2-chlorophenyl)-9-methyl-H-thieno[3,2-f] [1,2,4]triazolo-[4,3a][1,4]-diazepin-2-yl](4-morpholinyl)- 1-propane-one (WEB 2086) inhibited the PAF-induced enzyme release by human eosinophils in a dose-dependent manner. The viability of eosinophils were unaffected both by PAF and WEB 2086. The results suggest that PAF may amplify allergic and inflammatory reactions by release of preformed proteins from eosinophil granules.

Azepines↗
PubMed1984

Evidence for secretion of human eosinophil granule major basic protein and Charcot-Leyden crystal protein during eosinophil maturation.

Prior electron microscopic studies have suggested that immature eosinophils degranulate during normal maturation in human bone marrow. This hypothesis was tested by measuring levels of eosinophil granule major basic protein (MBP) and Charcot-Leyden crystal (CLC) protein in bone marrow sinusoidal blood. MBP and CLC protein levels were elevated initially in bone marrow sinusoidal blood from normal volunteers when compared with peripheral blood, and levels of both proteins decreased during serial sampling; CLC protein levels remained significantly elevated, while MBP levels declined to equal those of peripheral blood. To investigate whether MBP and CLC protein were secreted during eosinophil maturation, bone marrow cells were cultured in soft agar; MBP and CLC protein levels were measured in culture supernatants by RIA. There was a significant positive correlation between eosinophil colony growth and levels of each protein. Electron micrographs of cells in soft agar colonies provided ultrastructural evidence for secretion of granule products by immature eosinophils. These results support prior observations that eosinophil promyelocytes degranulate during maturation.

Adult↗
PubMed1993

Antigen-mediated pulmonary eosinophilia in immunoglobulin G1-sensitized guinea pigs: eosinophil peroxidase as a simple specific marker for detecting eosinophils in bronchoalveolar lavage fluid.

Eosinophil peroxidase (EPO) has been used previously to detect the number of eosinophils in the peritoneal exudate and bone marrow of mice. The present study was undertaken to determine 1) whether EPO activity may provide a measure of a change in eosinophils in bronchoalveolar lavage fluid (BALF) of guinea pigs, 2) whether immunoglobulin (Ig)G1 could play a role in pulmonary eosinophilia and 3) effects of pharmacological agents on the EPO response in an IgG1 passively sensitized animal model. The activity of EPO was assessed by the ability of cell lysates (0.1% Triton-100 treatment) to oxidize 1 mM o-phenylenediamine in the presence of 1 mM H2O2 for 5 min at 22 degrees C. The enzyme activity was found to be eosinophil dependent, inhibited by the EPO inhibitor 3-amino-1,2,4-triazole (IC50 = approximately 0.1 mM) and relatively resistant to heat treatment (no loss of activity after 2-hr preincubation at 56 degrees C). To determine antigen-dependent eosinophil and EPO responses, guinea pigs were passively sensitized i.p. with 0.5 mg/kg of an affinity-purified antiovalbumin (OA) IgG1. Two to 3 days later, the sensitized animals were injected with pyrilamine (5 mg/kg, i.p.) before OA aerosol challenge. Aerosolized OA (0.1%) caused a significant increase in both eosinophil number and EPO activity in BALF of sensitized guinea pigs at 18 to 24 hr post-challenge. At a given concentration of aerosolized OA, the enzyme activity increased as a function of the antibody dose and time post-OA challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Toxocara canis: failure to find IgE receptors (Fc epsilon R) on eosinophils from infected mice suggests that murine eosinophils do not kill helminth larvae by an IgE-dependent mechanism.

Eosinophils obtained by bronchoalveolar lavage (BAL) from the lungs of mice infected with Toxocara canis were characterized by flow cytometry with respect to cytophilic antibodies and surface Fc receptors. Freshly harvested BAL eosinophils were negative for sIgM, sIgA, sIgE, and Fc epsilon RII. These eosinophils were positive for sIgG1 and Fc gamma RII, although not all Fc gamma RIIs contained bound ligand. Culturing eosinophils for 24 or 48 hr with exogenous IgE and/or IL-4 did not induce IgE binding capacity or Fc epsilon RII expression. IL-4 did not decrease Fc gamma RII expression but did decrease ligand binding capacity by Fc gamma RII. These findings are in marked contrast to the results of studies characterizing the surface of both human and rat eosinophils and may indicate different functional activities for mouse BAL eosinophils in helminth infections.

Animals↗
PubMed1992

Detection of hypodense eosinophils by Percoll multilayer density gradient centrifugation in subjects with normal or slightly elevated eosinophilia. Poor reproducibility and eosinophils of density < 1.077 g/ml.

In patients with marked hypereosinophilia 'hypodense' and 'normodense' eosinophils have been found after density gradient centrifugation. Subsequently this terminology has also been used in studies of patients with milder eosinophilia. However, in these cases the differentiation between normo- and hypodense eosinophils was less clear. This might be due to the high imprecision of the test of density gradient centrifugation, as demonstrated in the first part of this study: the mean within-assay variance of the number of eosinophils in the different density layers was 35%. It was calculated that the test must be performed eight times to obtain an estimate of the true mean for the individual patient. In the second part of the study, the absolute number of 'hypodense eosinophils' in groups of patients with asthma (adults and children) and rheumatoid arthritis (adults) were compared to normal controls. Although a difference in the absolute number of hypodense eosinophils between groups of patients and controls could be demonstrated, the high imprecision of the test of density gradient centrifugation suggested that the technique used was not useful in an individual with normal or slightly elevated eosinophils in the peripheral blood.

Adult↗
PubMed1986

Involvement of eosinophils in leukemia: cytogenetic study of eosinophilic colonies from acute myelogenous leukemia associated with translocation (8;21).

We performed a cytogenetic analysis of eosinophilic colonies grown from bone marrow culture of a patient with acute myelogenous leukemia (FAB-M2) associated with t(8;21). The bone marrow, in which 50.2% myeloblasts and 5.6% eosinophils were observed, gave rise to eosinophilic colonies, as well as colonies consisting of immature myeloid cells. The cytogenetic analyses of the colonies were performed on two occasions. The first study revealed t(8;21) in 15 of 16 metaphases in randomly plucked colonies from a dish, in which 65% of the total colonies were those consisting of immature myeloid cells and 35% were eosinophilic colonies identified by positive staining with Luxol-Fast-Blue. The second study, in which eosinophilic colonies were selectively plucked for cytogenetic analysis, showed Cq- and Gq+ markers, which were considered to be t(8;21), in all metaphases (6/6). Our present study strongly suggests that an involvement of the eosinophilic series in the leukemic process of this patient.

Bone Marrow↗
PubMed1976

Structural determinants of the eosinophil: chemotactic activity of the acidic tetrapeptides of eosinophil chemotactic factor of anaphylaxis.

The acidic tetrapeptides of ECF-A, Ala/Val-Gly-Ser-Glu, exhibit peak in vitro chemotactic activity for human eosinophils at concentrations of 3 X 10(-8) M to 10(-6) M, and rapidly deactivate eosinophils to homologous and other stimuli at concentrations as low as 10(-10) M. The analogue Leu-Gly-Ser-Glu reaches peak activity at 10(-8)M-10(-7)M, while Phe-Gly-Ser-Glu requires 10(-4)M to elicit a peak response. Although inversion of the order of glycine and serine does not alter the eosinophil chemotactic activity of the tetrapeptides, deletion of glycine increases by 10-fold the concentration required for peak chemotactic activity, indicating the critical nature of the spacing between NH2- and COOH-terminal residues. The substituent COOH-terminal tripeptide, which is only marginally chemotactic, irreversibly suppresses eosinophil chemotactic responsiveness at a concentration 10,000-fold higher than concentrations necessary for deactivation by the intact tetrapeptide. The high concentration of tripeptide required for this cell directed effect, which is assumed to be analogous to deactivation, is attributed to the absence of the NH2-terminal residue which would facilitate effective interaction with the eosinophil. A substituent NH2-terminal tripeptide and amides of the NH2-terminal amino acids, which are devoid of chemotactic and deactivating activities, reversibly inhibit the tetrapeptide stimulus in a dose-response fashion. The additional finding that the NH2-terminal tripeptide protects the eosinophil from deactivation by the intact tetrapeptide confirms that the competitive interaction is stimulus specific.

Alanine↗
PubMed1977

Different composition of the eosinophilic bone marrow pool in reactive eosinophilia and eosinophilic leukaemia.

The composition of the eosinophilic cell series in the bone marrow has been analysed in 10 patients with a pronounced reactive eosinophilia (RE) and in 2 with eosinophilic leukaemia (EL). An imparied differentiation of the eosinophils was found in the EL patients compared with the RE group. Thus the ratio of eosinophilic promyelocytestmyelocytes: segmented eosinophils was 9.2 and 9.1, respectively, in the patients with EL and 0.1--3.1 (average 1.3) in the RE patients. It is suggested that EL is characterized by an impaired differentiation of the eosinophilic bone marrow cells and that the recognition of this abnormality is of value in the diffential diagnosis between EL and RE.

Adult↗
PubMed1979

Blood eosinophils and eosinophil cationic protein after acute myocardial infarction or corticosteroid administration.

Measurements of eosinophil cationic protein in serum (S-ECP) have been made in patients with acute myocardial infarction. In spite of low numbers of blood eosinophils in the acute phase of the disease S-ECP levels fluctuated widely with often markedly raised levels. Peak levels of S-ECP were significantly correlated (P less than 0.001) to peak numbers of blood eosinophils, although the former usually occurred within the first 2-3 d of illness and the latter usually after the sixth day. Intravenous injection of 0.5 g methylprednisolone in healthy individuals reduced blood eosinophil counts for at least 24 h, but S-ECP levels remained within normal limits. These results suggest that ECP is released from eosinophils in vivo. The raised levels of S-ECP in patients with acute myocardial infarction are probably due to the active participation of eosinophils in the inflammatory process.

Acute Disease↗
PubMed1994

Eosinophil inflammation of the nasal mucosa in allergic and non-allergic rhinitis measured by eosinophil cationic protein levels in native nasal fluid and serum.

Eosinophil inflammation is essential in many cases of allergic and non-allergic rhinitis. Activated eosinophils release toxic granule proteins. In this study, we compared the degree of local nasal and systemic eosinophil activation by the determination of eosinophil cationic protein (ECP) in serum and native nasal fluid from 119 patients. We found no significant differences in serum ECP levels of the various patient groups. In all patient groups, except in the vasomotor rhinitis group, nasal fluid ECP levels differed significantly from normal controls. We found a nasal fluid ECP (mean +/- SEM) of 32.6 +/- 8.1 ng/ml for normals, 106 +/- 39.7 for non-rhinitic atopics, 87.6 +/- 20.8 ng/ml for patients with chronic non-allergic sinusitis, 101.3 +/- 40.4 ng/ml for patients with a history of pollinosis, 150.5 +/- 35.1 ng/ml for patients with acute pollinosis, 84.7 +/- 24.7 ng/ml for individuals with perennial allergic rhinitis and 112.9 +/- 25.6 ng/ml for patients with both perennial and seasonal allergy. Patients with nasal polyps had mean nasal ECP levels of 146.9 +/- 57.7 ng/ml in absence of allergy and 147.9 +/- 54.9 ng/ml in the presence of allergy. Nasal ECP was 67.0 +/- 22.4 for patients with hyperreactive rhinitis. We found a significant correlation of 0.95 between nasal eosinophils and nasal ECP. Nasal ECP and a subjective symptom score only correlate significantly for chronic sinusitis. We conclude that monitoring native nasal fluid ECP levels may be useful in the diagnosis and management of nasal inflammation. Elevated ECP in nasal secretion may originate from upregulated eosinophil degranulation and thus is a marker for local inflammation although not specific for any particular nasal disease.

Adult↗
PubMed1993

Nanomolar arachidonic acid influences the respiratory burst in eosinophils and neutrophils induced by GTP-binding protein. A comparative study of the respiratory burst in bovine eosinophils and neutrophils.

To investigate a possible role of phospholipase A2 (PLA2) in the respiratory burst in bovine eosinophilic and neutrophilic leukocytes dependent on GTP-binding protein (G-protein), we permeabilized these cells with Staphylococcus aureus alpha-toxin and induced NADPH oxidase activity with the non-hydrolysable GTP analogue GTP[S] or the aluminium tetrafluoro complex AlF4-. Under same experimental conditions, cells responded with different onset times. The onset time for eosinophils was 50-200 s, for neutrophils it was only a few seconds. GTP[S] stimulated in neutrophils only 5% of the respiratory burst compared to eosinophils, whereas AlF4(-)-induced comparable responses (neutrophils 120% of eosinophils). GDP inhibited these responses with an IC50 value of 2.4 mM. Arachidonic acid showed, with the exception of AlF4- stimulated neutrophils, on both stimuli and cell types an enhancing effect (150%) that reached its maximum at 0.1-1 microM. The PLA2 inhibitor 4-bromophenacylbromide reduced the GTP[S]- and AlF4(-)-induced response almost completely (10 microM) and the inhibition was not significantly different for eosinophils and neutrophils (IC50 1-3 microM). If the respiratory burst was reduced with 4-bromophenacylbromide to 1-4% of the original value, 10% of the basal NADPH oxidase activity could be restored by addition of only 20-100 nM arachidonic acid. In addition, the PLA2 activator adriamycin enhanced the response in a dose-dependent manner and in the same order as arachidonic acid did. The results presented above suggest that the respiratory burst may be regulated by different low-molecular-mass and/or heterotrimeric G-proteins and an active role for arachidonic acid or its metabolites in the activation and the maintenance of the direct G-protein-stimulated respiratory burst in bovine eosinophils and neutrophils.

Aluminum Compounds↗
PubMed1995

Presence of eosinophilic precursors in the human thymus: evidence for intra-thymic differentiation of cells in eosinophilic lineage.

The distribution of myeloid cells in the human thymus was investigated by light and electron microscopy, immunohistochemistry, and/or flow cytometry. A series of 74 thymic samples, from newborn to 37 year old patients, were studied. By light microscopy, aggregates of mononuclear cells were frequently present in intralobular septa and outer medulla. Among those cells, eosinophilic precursors (promyelocyte, myelocytes and metamyelocytes) were readily identified. These immature granular cells were present in all pre-involutional thymi, and were particularly frequent in the thymi of patients who were younger than 5 years of age. The cells made up 30-50% of the total eosinophilic population and were frequently observed as a group of cells at various stages of differentiation, suggesting that they differentiate from pre-existing precursors in the thymus. These eosinophilic precursors were mostly located in the intralobular septa and fibroreticular network at the corticomedullary junction, while mature eosinophils were scattered throughout the thymus. Flow cytometric analyses, using stem cell-enriched preparations, showed that cells expressing CD33 or CD34 constituted on average 2.55% and 3.33% (0.09% and 0.12% of the total cells), respectively. CD33+/CD34+ coexpressors were also identified, and they constituted 0.36% of the analyzed cells (0.01% of the total cells). No statistical difference in the proportions of CD33+ and/or 34+ cells was noted between any age groups. It is concluded that eosinophilic precursors present in the thymus differentiate into cells in the eosinophilic lineage in particular areas such as the intralobular septa and fibroreticular network of the outer medulla in preinvolutional human thymi.

Adolescent↗
PubMed1992

Human peripheral blood hypodense eosinophil proteins are more labeled with 32P than the normodense eosinophil proteins.

Peripheral blood eosinophils from patients with atopic dermatitis and normal healthy controls were isolated on a Percoll gradient and were incubated with [32P]orthophosphoric acid. After stopping the reaction, SDS/PAGE was performed and autoradiographs were prepared to determine the incorporation of 32P into proteins. Eosinophils developed at least 14 protein bands below 66.2 kDa by SDS/PAGE and the differences of the protein staining patterns between hypodense and normodense eosinophils were present. In the autoradiographs five distinct radioactive bands were observed below 31 kDa. 32P incorporation into the bands of hypodense eosinophils was stronger than that of normodense eosinophils, suggesting possible involvement of protein phosphorylation in the activation process of human eosinophils.

Adult↗
PubMed1996

Heterogeneous chemotactic response of eosinophils from patients with atopic dermatitis to eosinophil chemotactic factors.

The chemotactic response of eosinophils from 16 patients with atopic dermatitis (AD) to 5 eosinophil chemotactic factors (ECFs) were examined to clarify whether the response is associated with the clinical severity of AD. The factors included ECF-P15, -P16, -P17, -P18 and -P19 and were derived from a T cell line, STO-2. The patients were divided into 2 groups according to the percentage migration of eosinophils produced by the ECFs: a high-responding group (migration > 40%), and a low-responding group (migration < 30%). In a statistical analysis, eosinophils from patients with AD and atopic respiratory diseases (ARD) were found to be high-responding and those from patients with AD alone low-responding (p < 0.01). In a comparison of the chemotactic response of eosinophils from patients with AD alone at remission and at exacerbation, the percentage migrations in response to ECF-P15 and ECF-P16 at exacerbation were significantly higher than that at remission (p < 0.05). It is thus suggested that this type of heterogeneous response of eosinophils to STO-2-derived ECFs could provide a useful tool for evaluation of disease severity in patients with AD.

Adolescent↗
PubMed1994

Evidence for eosinophil activation in eosinophilic cystitis.

Eosinophilic cystitis (EC) is a rare condition. Recent studies have shown that activated eosinophils release cytotoxic cationic proteins which can induce tissue damage. Moreover, in vitro studies have shown that interleukin-5 (IL-5) is a cytokine able to attract and activate eosinophils. The goal of this study was to detect a possible activation of eosinophils in EC using electron microscopy, in situ hybridization with an IL-5 RNA probe and immunochemistry with a specific anti-IL-5 antibody. Using these combined methods in a typical case of EC, we found numerous activated eosinophils synthesizing and secreting IL-5 protein. IL-5 could enhance the activation of eosinophils and their cytotoxic potential in bladder tissues. This mechanism might explain the chronicity of the lesions in EC.

Cystitis↗
PubMed2004

Ultrastructural localization of matrix metalloproteinase-9 in eosinophils from the cerebrospinal fluid of mice with eosinophilic meningitis caused by Angiostrongylus cantonensis.

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of eosinophilic meningitis caused by Angiostrongylus cantonensis. In the present study, such meningitis in mice was found to be associated with elevated expression of MMP-9 mRNA, elevated MMP-9 concentrations and enhanced MMP-9 activity in the cerebrospinal fluid (CSF). Immunocytochemistry showed that an anti-MMP-9 antibody reacted with macrophages, neutrophils and eosinophils from the CSF. As eosinophils are generally considered to be effector cells in host defence against A. cantonensis infection, high-resolution immuno-electron microscopy was then used to confirm the localization of MMP-9 in the eosinophils from the CSF. The method used, which was based on immunogold, indicated that the eosinophilic MMP-9 was mostly localized in the 'small' granules in the cytoplasm and along the cell membrane, and not in the crystalloid-containing secretory granules observed. It therefore appears that MMP-9 is synthesised and/or stored in the small granules of the eosinophils, and is released into the subarachnoid space of the host's brain by secretion or cell rupture.

Angiostrongylus cantonensis↗
PubMedDate not supplied

Eosinophil active cytokines and surface analysis of eosinophils in Churg-Strauss syndrome.

There are few reports regarding the measurement of cytokines and surface analysis of eosinophils in Churg-Strauss syndrome (CSS). To examine the pathophysiology of CSS, concentrations of cytokines in serum and bronchoalveolar lavage fluid (BALF), and surface antigens on peripheral blood eosinophils were analyzed in five patients with CSS. Concentrations of cytokines (interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-3 (IL-3), interleukin-5 (IL-5) and granulocyte/macrophage colony stimulating factor (GM-CSF) were measured using ELISA. Surface antigens on eosinophils in peripheral blood were analyzed using flow cytometry. A concentration of interleukin-5 (IL-5) and TNF-alpha in serum was detected in five cases; however IL-1 beta, GM-CSF, and IL-3 were detected in 3 of 5, 2 of 5, and 1 of 5 patients, respectively. In BALF, TNF-alpha and IL-5 were detected in 2 of 3 and 1 of 3 patients, respectively; however, neither IL-1 beta, GM-CSF, nor IL-3 was detected in any. Newly expressed surface antigens such as CD25, CD4, and CD69 were observed on peripheral blood eosinophils in five cases. CD54 and HLA-DR were expressed in 4 of 5 and 3 of 5 patients, respectively. Eosinophils in peripheral blood are activated to various degrees, possibly depending on cytokine stimulation. This eosinophil activation may be related to the clinical stage of CSS.

Adult↗
PubMed2006

A case of acute eosinophilic myopericarditis presenting with cardiogenic shock and normal peripheral eosinophil count.

Eosinophilic myocarditis usually results from myocardial damage as a result of drugs or parasites, and is generally associated with increased peripheral eosinophil count. This form of myocarditis is difficult to diagnose clinically. A 25 year-old previously healthy woman was transferred from a local clinic because of hypotension and dyspnea with sudden cardiogenic shock after a three day history of gastrointestinal illness. Echocardiography revealed concentric left ventricular wall thickening with moderate pericardial effusion. Biopsy of endomyocardial tissue from the right ventricle showed diffuse infiltration of inflammatory cells, mostly eosinophils, even though the patient had a peripheral eosinophil count that was normal at the time of biopsy. The patient was treated with corticosteroids for the symptoms of pericarditis, and she recovered without cardiac sequelae, clinically and echocardiographically. We here report a case of acute eosinophilic myopericarditis, with cardiogenic shock, diagnosed by endomyocardial biopsy with normal peripheral eosinophil count at the time of biopsy, and complete recovery without sequelae.

Acute Disease↗