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Respiratory Burst (respiratory + burst)

Distribution by Scientific Domains

Medical Sciences	59%
Earth and Environmental Science	18%
Chemistry	12%
Life Sciences	9%

Distribution within Medical Sciences

Dermatology	25%
Immunology	15%

Kinds of Respiratory Burst

neutrophil respiratory burst

Terms modified by Respiratory Burst

respiratory burst activity

Selected Abstracts

Ethanol-Induced Malfunction of Neutrophils Respiratory Burst on Patients Suffering From Alcohol Dependence

ALCOHOLISM, Issue 10 2008
Dirk Breitmeier
Background:, Polymorphonuclear, neutrophil granulocytes (PMN) play a major role in the control of infections, and people who abuse alcohol are susceptible to infections. Resistance against infections ensues intracellularly following initial phagocytosis of microorganisms with the oxygen-dependent respiratory burst, the key enzyme of which is the respiratory burst oxidase, whereby oxygen radicals are produced for microbial destruction. To date there is insufficient information available in connection with the process of impaired defence against infection in patients suffering from alcohol dependence. Therefore, our investigation was carried out to determine the influence of alcohol exposition on the formation of oxygen radicals and the respiratory burst. Methods:, 4.5 ml of whole blood was taken from 10 healthy adults and 10 patients suffering from alcohol dependence. An additional 3.5 ml of whole blood was taken from the alcoholic patients for determination of the blood alcohol concentration. The respiratory burst of PMN was tested using the Four-Colour-Continuous Flow Cytometer. Each experimental procedure consisted of 4 test samples [negative controls, Escherichia coli, FMLP-supplement (N-formyl-l-methionyl-l-leucyl-l-phenylalanin), PMA-supplement (phorbol-12-myristate-13-acetate)]. Differing concentrations of ethanol were also introduced to each of the tests performed (0.20 to 4.00 g/l). Results:, Ethanol revealed a marked decrease of burst activity in those patients suffering from alcoholism with increased alcohol concentration. A dependence between the burst activity and the ethanol concentration was seen to be statistically significant. This effect was only evident after stimulation with E. coli and FMLP in those patients with alcohol dependence. Conclusion:, The results presented in this study show an impairment in the function of PMN in those patients addicted to alcohol due to the decrease in burst activity. In view of the results of the different stimuli, the second-messenger effects were not evident. A clarification of this phenomenon could well be assumed as an allosteric receptor effect on the burst oxidase, namely, a direct effect on the phagocytosis interaction between circulating granulocytes and causative organisms. [source]

Pityriarubins, Novel Highly Selective Inhibitors of Respiratory Burst from Cultures of the Yeast Malassezia furfur: Comparison with the Bisindolylmaleimide Arcyriarubin A

CHEMBIOCHEM, Issue 12 2005
Hans-Joachim Krämer Dr.
Abstract Pityriasis versicolor is the most common skin mycosis in humans worldwide. Yeasts of the genus Malassezia, particularly M. furfur, a saprophyte occurring widely on human skin, are generally regarded as the causative agents. M. furfur is able to convert tryptophan into a variety of indole alkaloids, some of them showing biological properties that correlate well with certain clinical features of pityriasis versicolor. This suggests a possible role for these compounds in the pathophysiology of the disease. We here report that the novel pityriarubins A, B and C, isolated from cultures of the yeast, inhibit respiratory burst in human neutrophils, activated by various agents, in a highly selective, unexpected manner. The release of 5-lipoxygenase products after challenge of neutrophils with the calcium ionophore A23187 is also inhibited in a dose-dependent manner. These activities reflect the close structural relationship of pityriarubins to bisindolylmaleimides, which have recently gained great interest as protein kinase inhibitors. [source]

Neutrophil respiratory burst is decreased in scleroderma and normalized by near-infrared mediated hyperthermia

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 6 2006
J. Foerster
Summary Background., The production of reactive oxygen species (ROS) by fibroblasts has been suggested to contribute to scleroderma pathogenesis. Infrared-mediated hyperthermia has recently been shown to be of benefit in scleroderma. Aim., As the contribution of neutrophils and monocytes to ROS formation in scleroderma is unknown, we studied respiratory burst in these cell types. We also aimed to test the hypothesis that near-infrared (IRA) treatment may effect burst activity. Methods., We determined respiratory burst in patients with scleroderma (n = 22) and age- and sex-matched controls (n = 20) at baseline, and after high-level stimulation by phorbolmyristyl acetate (PMA) and low-level stimulation by non-opsonized zymosan. Respiratory burst was also assessed before and after a series of infrared-mediated hyperthermia treatments. Results., Unexpectedly, we observed no increase but instead a slight but statistically significant reduction in baseline and zymosan-stimulated respiratory burst in scleroderma neutrophils (P < 0.001) and monocytes (P < 0.005). This decrease in burst activity was nonspecific, as it was also observed in patients with another active inflammatory disease, psoriasis. IRA treatment induced a cell-type-specific normalization of respiratory burst only in neutrophils, but not in monocytes. Intriguingly, neutrophil-specific normalization of ROS formation persisted for 6 weeks after the end of IRA treatment, in concordance with the previously reported clinical responses to this therapy. Conclusion., Neutrophils and monocytes do not exhibit cell-autonomous overproduction of ROS in scleroderma, thereby implicating fibroblasts as main source for clinically relevant ROS accumulation. Furthermore, repeated mild infrared-mediated hyperthermia exerts a lasting cell-type-specific effect on neutrophils. [source]

Reduced post-operative neutrophil activation in liver transplant recipients suffering from post-hepatitic cirrhosis

CLINICAL TRANSPLANTATION, Issue 6 2009
Björn Jüttner
Abstract:, Background:, It has been supposed that liver transplant recipients with hepatitis C virus infection have a higher incidence of infectious complications after transplantation. This study was designed to investigate whether neutrophil function is immediately affected by liver transplantation. Methods:, Biochemical values, plasma levels of myeloperoxidase (MPO), hydrogen peroxide production of neutrophils and neutrophil,platelet complexes were analyzed in 32 patients who underwent liver transplantation and 20 healthy volunteers. Results:, MPO levels were significantly increased 24 h after reperfusion. In post-hepatitic patients levels were significantly lower three d up to one wk post-transplant than in patients due to other liver diseases. One wk post-operatively the respiratory burst activity following N -formyl-methionyl-leucylphenylalanine (fMLP) or (tumor necrosis factor-,) TNF-,/fMLP stimulation was depressed in post-hepatitic recipients. Respiratory burst stimulated with phorbol 12-myristate 13-acetate in these patients was increased one wk after transplantation. One d after transplantation the neutrophil,platelet complexes decreased significantly throughout the post-operative period. Conclusions:, The results of this study suggest a reduced post-operative neutrophil activation in liver transplant recipients suffering from post-hepatitic cirrhosis compared to cirrhosis due to other causes. We hypothesized that neutrophil dysfunction in those patients depends on the underlying disease with an increased susceptibility to bacterial or fungal infections. [source]

Immunosuppression in the northern leopard frog (Rana pipiens) induced by pesticide exposure

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2003
Mary-Kate Gilbertson
Abstract An injection study and a field study were used to investigate the hypothesis that environmental xenobiotics have the potential to alter the immune function of northern leopard frogs (Rana pipiens). Three assays, IgM-specific antibody response to keyhole limpet hemocyanin linked to dinitrophenyl (KLH-DNP), zymozan induced chemiluminescence (CL) of whole blood and the delayed-type hypersensitivity (DTH), were used to assay humoral, innate and cell-mediated immune endpoints. Sublethal doses of DDT (923 ng/g wet wt), malathion (990 ng/g wet wt), and dieldrin (50 ng/g wet wt) were used in the injection study. In all pesticide-injected groups, antibody response was dramatically suppressed, DTH reactions were enhanced, and respiratory burst was lower. When the order of administration of pesticides and antigens was reversed, no differences in immune function between the control and dosed groups were apparent, indicating that frogs exposed to pathogens prior to pesticide exposure can still respond. A field study found significant differences in immune function between frog populations in pesticide-exposed and pesticide-free locations. The antibody response and CL were suppressed and the DTH enhanced in frogs from Essex County (ON, Canada). Overall, the results suggest that exposure to these pesticides can cause both stimulatory and suppressive immune changes in adult frogs and is doing so in wild populations. [source]

Retinol binding protein isolated from acute renal failure patients inhibits polymorphonuclear leucocyte functions

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2004
G. Cohen
Abstract Background, Protein factors accumulating in sera of patients with end-stage renal disease (ESRD) that interfere with the nonspecific immune response by inhibiting essential functions of polymorphonuclear leucocytes (PMNLs) have previously been described. No such factor has been isolated from acute renal failure (ARF) patients to date. Materials and methods, Using a three-step chromatographic procedure involving ion exchange, size exclusion and hydrophobic interaction chromatography we purified the apo- and holo-form of retinol binding protein (RBP) from high-flux dialyser (polyacrylonitrile; AN69) ultrafiltrates of patients with ARF. Their effect on the chemotaxis of PMNLs isolated from healthy donors was determined by the under-agarose method. Whole-blood assays applying flow cytometry were used to assess phagocytosis and the oxidative metabolism of PMNLs. Apoptosis was assessed by determining the DNA content using propidium iodide. Results, Isolated apo- and holo-forms of RBP were truncated on their C-terminus as determined by mass spectrometry. All isolates significantly inhibited the chemotactic movement of PMNLs obtained from healthy donors and the PMNL oxidative metabolism stimulated by E. coli. These effects were concentration dependent. Retinol binding protein had no influence on the PMNL oxidative metabolism stimulated by PMA and on PMNL phagocytosis. Commercially available RBP isolated from urine influenced PMNL functions in the same way. Inhibition of p38 mitogen-activated protein kinase (MAPK) by SB203580 significantly attenuated the phagocytosis-induced respiratory burst and RBP did not lead to a further decrease. Polymorphonuclear leucocyte apoptosis was significantly inhibited by RBP. Conclusions, The apo- and holo-forms of RBP isolated from the ultrafiltrate of ARF patients inhibit PMNL chemotaxis, oxidative metabolism and apoptosis. Therefore, RBP may be considered a uraemic toxin contributing to a disturbed immune defence. [source]

,-GalCer ameliorates listeriosis by accelerating infiltration of Gr-1+ cells into the liver

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2010
Masashi Emoto
Abstract ,-Galactosylceramide (,-GalCer) activates invariant (i)NKT cells, which in turn stimulate immunocompetent cells. Although activation of iNKT cells appears critical for regulation of immune responses, it remains elusive whether protection against intracellular bacteria can be induced by ,-GalCer. Here, we show that ,-GalCer treatment ameliorates murine listeriosis, and inhibits inflammation following Listeria monocytogenes infection. Liver infiltration of Gr-1+ cells and ,/, T cells was accelerated by ,-GalCer treatment. Gr-1+ cell and ,/, T-cell depletion exacerbated listeriosis in ,-GalCer-treated mice, and this effect was more pronounced after depletion of Gr-1+ cells than that of ,/, T cells. Although GM-CSF and IL-17 were secreted by NKT cells after ,-GalCer treatment, liver infiltration of Gr-1+ cells was not prevented by neutralizing mAb. In parallel to the numerical increase of CD11b+Gr-1+ cells in the liver following ,-GalCer treatment, CD11b,Gr-1+ cells were numerically reduced in the bone marrow. In addition, respiratory burst in Gr-1+ cells was enhanced by ,-GalCer treatment. Our results indicate that ,-GalCer-induced antibacterial immunity is caused, in part, by accelerated infiltration of Gr-1+ cells and to a lesser degree of ,/, T cells into the liver. We also suggest that the infiltration of Gr-1+ cells is caused by an accelerated supply from the bone marrow. [source]

Role of Ca2+/calmodulin regulated signaling pathways in chemoattractant induced neutrophil effector functions

FEBS JOURNAL, Issue 18 2002
Comparison with the role of phosphotidylinositol-3 kinase
In human neutrophils, both changes in intracellular Ca2+ concentrations, [Ca2+]i, and activation of phosphatidylinositol-3 kinase (PtdIns3K) have been proposed to play a role in regulating cellular function induced by chemoattractants. In this study we have investigated the role of [Ca2+]i and its effector molecule calmodulin in human neutrophils. Increased [Ca2+]i alone was sufficient to induce phosphorylation of extracellular signal-regulated protein kinase 2 (ERK2), p38 mitogen activated kinase (p38 MAPK), protein kinase B (PKB) and glycogen synthase kinase-3, (GSK-3,). Inhibition of calmodulin using a calmodulin antagonist N -(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W7), did not effect N -formyl-methionyl-leucyl-phenylalanine (fMLP) induced ERK, p38 MAPK or GSK-3, phosphorylation, but attenuated fMLP induced PKB phosphorylation. PCR analysis of human neutrophil cDNA demonstrated variable expression of members of the Ca2+/calmodulin-dependent kinase family. The roles of calmodulin and PtdIns3K in regulating neutrophil effector functions were further compared. Neutrophil migration was abrogated by inhibition of calmodulin, while no effect was observed when PtdIns3K was inhibited. In contrast, production of reactive oxygen species was sensitive to inhibition of both calmodulin and PtdIns3K. Finally, we demonstrated that chemoattractants are unable to modulate neutrophil survival, despite activation of PtdIns3K and elevation [Ca2+]i. Taken together, our data indicate critical roles for changes in [Ca2+]i and calmodulin activity in regulating neutrophil migration and respiratory burst and suggest that chemoattractant induced PKB phosphorylation may be mediated by a Ca2+/calmodulin sensitive pathway in human neutrophils. [source]

Neutrophil depletion protects against murine acetaminophen hepatotoxicity,,

HEPATOLOGY, Issue 6 2006
Zhang-Xu Liu
We previously reported that liver natural killer (NK) and NKT cells play a critical role in mouse model of acetaminophen (APAP)-induced liver injury by producing interferon gamma (IFN-,) and modulating chemokine production and subsequent recruitment of neutrophils into the liver. In this report, we examined the role of neutrophils in the progression of APAP hepatotoxicity. C57BL/6 mice were given an intraperitoneal toxic dose of APAP (500 mg/kg), which caused severe acute liver injury characterized by significant elevation of serum ALT, centrilobular hepatic necrosis, and increased hepatic inflammatory cell accumulation. Flow cytometric analysis of isolated hepatic leukocytes demonstrated that the major fraction of increased hepatic leukocytes at 6 and 24 hours after APAP was neutrophils (Mac-1+Gr-1+). Depletion of neutrophils by in vivo treatment with anti-Gr-1 antibody (RB6-8C5) significantly protected mice against APAP-induced liver injury, as evidenced by markedly reduced serum ALT levels, centrilobular hepatic necrosis, and improved mouse survival. The protection was associated with decreased FasL-expressing cells, cytotoxicity against hepatocytes, and respiratory burst in hepatic leukocytes. In intracellular adhesion molecule (ICAM)-1,deficient mice, APAP caused markedly reduced liver injury when compared with wild-type mice. The marked protection in ICAM-1,deficient mice was associated with decreased accumulation of neutrophils in the liver. Hepatic GSH depletion and APAP-adducts showed no differences among the antibody-treated, ICAM-1,deficient, and normal mice. In conclusion, accumulated neutrophils in the liver contribute to the progression and severity of APAP-induced liver injury. (HEPATOLOGY 2006;43:1220,1230.) [source]

Regulation of human neutrophil-mediated cartilage proteoglycan degradation by phosphatidylinositol-3-kinase

IMMUNOLOGY, Issue 1 2001
C. S. T. Hii
Summary The ability of neutrophils to degrade cartilage proteoglycan suggests that the neutrophils that accumulate in the joints of rheumatoid arthritis patients are mediators of tissue damage. The regulatory mechanisms which are relevant to the proteoglycan-degrading activity of neutrophils are poorly understood. Since phosphatidylinositol 3-kinase (PI3-K), protein kinase C (PKC), the extracellular signal-regulated protein kinase (ERK)1/ERK2 and cyclic adenosine monophosphate (cAMP) have been reported to regulate neutrophil respiratory burst and/or degranulation, a role for these signalling molecules in regulating proteoglycan degradation was investigated. Preincubation of human neutrophils with GF109203X (an inhibitor of PKC), PD98059 (an inhibitor of MEK, the upstream regulator of ERK1/ERK2) or with forskolin or dibutyryl cAMP, failed to suppress proteoglycan degradation of opsonized bovine cartilage. In contrast, preincubation of neutrophils with wortmannin or LY294002, specific inhibitors of PI3-K, inhibited proteoglycan degradation. Incubation of neutrophils with cartilage resulted in the activation of PI3-K in neutrophils, consistent with a role for PI3-K in proteoglycan degradation. Activation of PI3-K and proteoglycan degradation was enhanced by tumour necrosis factor-,. Degradation caused by neutrophils from the synovial fluid of rheumatoid arthritis patients was also inhibited by wortmannin. These data demonstrate that the proteoglycan degradative activity of neutrophils required PI3-K but not PKC or the ERK1/ERK2/ERK5 cascades and was insensitive to increases in intracellular cAMP concentrations. [source]

Extensive xanthelasma associated with anaplastic large cell lymphoma and hyperimmunoglobulin E syndrome

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2003
Mi-Woo Lee MD
A 57-year-old woman presented with a 6-month history of an extensively spreading, yellowish patch on the periorbital areas and cheeks. A diagnosis of hyperimmunoglobulin E syndrome had been made at the age of 22 years on the basis of an eczematous eruption, recurrent furunculosis, and a persistently elevated immunoglobulin E (IgE) level. Her past medical history revealed that she had suffered from numerous recurrent bouts of chronic sinusitis, otitis media, oral candidiasis, orbital cellulitis, acne rosacea, and pneumonia caused by cytomegalovirus since her twenties. In addition, 1 year ago, anaplastic large cell lymphoma of the cervical lymph node (stage IIIb) developed, and she received six cycles of cyclophosphamide,doxorubicin,vincristine,prednisolone (CHOP) chemotherapy with partial remission. None of her family had any of these problems. Cutaneous examination showed extensive, symmetric, noninfiltrated macular areas of distinct yellow discoloration around the eyes and on both cheeks (Fig. 1). There were also erythematous papulonodular eruptions on the nose and both cheeks, which were thought to be acne rosacea. Laboratory findings were normal, except for an elevated IgE level (8157 IU/mL). Serum concentrations of IgG, IgA, and IgM were normal. Serum complement levels were normal, as evidenced by normal C3, C4, and CH50. Although she had a previous history of a decreased level (12%) of nitroblue tetrazolium (NBT) test (control, 53%), NBT test at our institute was normal. Neutrophil function tests, including neutrophil chemotaxis, neutrophil phagocytosis, neutrophil respiratory burst, and neutrophil microbial killing test, by flow cytometry, showed normal results. The serum lipid levels, including total cholesterol, triglyceride, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol, were normal. Serum lipoprotein electrophoresis was normal. A biopsy specimen revealed scattered foamy cells throughout the dermis. The larger clusters of foamy cells tended to group around the blood vessels of the dermis (Fig. 2). Figure 1. Extensively distributed, yellowish, flat xanthelasma on the face Figure 2. Clusters of foamy cells around the blood vessels of the dermis (hematoxylin and eosin, ×400) [source]

Ethanol-Induced Malfunction of Neutrophils Respiratory Burst on Patients Suffering From Alcohol Dependence

Effect of cigarette smoke extract on the polymorphonuclear leukocytes chemiluminescence: influence of a filter containing glutathione

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2005
B. Zappacosta
Abstract Cigarette smoking is known to be a risk factor for several chronic and neoplastic diseases. Many compounds formed by cigarette burning, ranging from particulate materials to water solutes and gaseous extracts, are considered to be noxious agents, and many biochemical and molecular mechanisms have been proposed for the toxic effects of cigarette smoke. The oral cavity and the upper respiratory tract represent the first contact areas for smoke compounds; even a single cigarette can produce marked effects on some components of the oral cavity, either chemical compounds, such as glutathione and enzymes, or cellular elements, such as polymorphonuclear leukocytes. Several studies suggest a protective role of glutathione against the noxious effects of tobacco smoke; the sulphydril groups of glutathione, in fact, could react with some smoke products, such as unsaturated aldehydes, leading to the formation of harmless intermediate compounds and simultaneously preventing the inactivation of metabolically essential molecules, such as some enzymes. In this paper we analyse the effect of a filter containing glutathione on the respiratory burst of polymorphonuclear leukocytes exposed to aqueous extract of cigarette smoke, measuring their chemiluminescence activity. The results of this paper indicate that the GSH--containing filter has a likely protective effect against the inhibition of cigarette smoke extract on polymorphonuclear leukocyte activity. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Respiratory burst activity of polymorphonuclear cells is dependent on the cell preparation technique

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2003
J. Zhao
Background: Controversial results have been reported regarding the effect of anaesthetics on superoxide anion production during the respiratory burst (RB) of polymorphonuclear cells (PMN). The differences could be caused by the cell preparation methods and the aim of this study was to compare two techniques. Methods: RB activity was measured in cell suspensions isolated with the single-step Ficoll procedure and in unfractionated whole blood. Two concentrations of propofol (therapeutic and 10-fold of this, 6 µg ml,1 or 60 µg ml,1) were investigated after cell preparation with both methods. RB was stimulated with Escherichia coli (E. coli), phorbol 12-myristate 13-acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (fMLP) and measured by means of fluorescence intensity in a flow cytometer. Results: The percentage of PMNs in whole blood which generate superoxide anions in response to fMLP was significantly lower (2.5 ± 0.7%; mean ± SEM) than that in Ficoll isolated cell suspensions (15.1 ± 1.7%). Incubation with propofol led to a concentration-related decrease of RB activity in Ficoll separated PMNs after both PMA and fMLP stimulation. No significant effect of propofol was observed on the RB in PMA stimulated whole blood samples. Conclusion: The results suggest that the influence of cell preparation methods should be considered when the in vitro effects of anaesthetics on PMN functions are studied with flow cytometric methods. [source]

Effects of a natural parasitical infection (Lernanthropus kroyeri) on the immune system of European sea bass, Dicentrarchus labrax L

PARASITE IMMUNOLOGY, Issue 12 2009
M. A. HENRY
Summary The immune response of European sea bass, Dicentrarchus labrax, to a natural infection by the copepod parasite Lernanthropus kroyeri was evaluated for the first time in vivo. The results clearly demonstrated the triggering of the fish immune system by the parasite. Lysozyme activity and alternative complement pathway were involved in the early action against the parasitical infection, whilst classical complement and respiratory burst (RB) activity took over in the later stages of infection. It was hypothesized that the levels of alternative and classical complement and RB stimulation indexes may determine the resistance capacity of the fish to the parasite. It is not clear how parasites can survive despite the strong immunological arsenal deployed by the fish. The continual increase of prevalence and severity of parasite infection suggested that the parasite's mechanism of evasion of the immune system was extremely successful. The contrasting decrease in the negative effects of parasites on the fish health (such as gills anaemia) suggested that an equilibrium between the parasites and their hosts was reached in chronic infection. These dynamic interactions between parasites and fish hosts were probably the main determinant of host specificity. [source]

Nimbidin suppresses functions of macrophages and neutrophils: relevance to its antiin,ammatory mechanisms

PHYTOTHERAPY RESEARCH, Issue 5 2004
Gurpreet Kaur
Abstract Nimbidin is a mixture of tetranortriterpenes and is the major active principle of the seed oil of Azadirachta indica A. Juss (Meliaceae) possessing potent antiin,ammatory and antiarthritic activities. The present study revealed that nimbidin signi,cantly inhibited some of the functions of macrophages and neutrophils relevant to the in,ammatory response following both in vivo and in vitro exposure. Oral administration of 5,25 mg/kg nimbidin to rats for 3 consecutive days signi,cantly inhibited the migration of macrophages to their peritoneal cavities in response to in,ammatory stimuli and also inhibited phagocytosis and phorbol-12-myristate-13-acetate (PMA) stimulated respiratory burst in these cells. In vitro exposure of rat peritoneal macrophages to nimbidin also inhibited phagocytosis and PMA stimulated respiratory burst in these cells. Nimbidin also inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS) stimulated macrophages following in vitro exposure, whereas interleukin 1 (IL-1) was only weakly inhibited. Probing the mechanism of NO inhibition revealed that nimbidin ameliorated the induction of inducible NO synthase (iNOS) without any inhibition in its catalytic activity. In addition, nimbidin also attenuated degranulation in neutrophils assessed in terms of release of , -glucuronidase, myeloperoxidase and lysozyme. The results suggest that nimbidin suppresses the functions of macrophages and neutrophils relevant to in,ammation. Thus nimbidin can be valuable in treating in,ammation/in,ammatory diseases. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Integration of K+ and Cl, currents regulate steady-state and dynamic membrane potentials in cultured rat microglia

THE JOURNAL OF PHYSIOLOGY, Issue 3 2005
Evan W. Newell
The role of ion channels and membrane potential (Vm) in non-excitable cells has recently come under increased scrutiny. Microglia, the brain's resident immune cells, express voltage-gated Kv1.3 channels, a Kir2.1-like inward rectifier, a swelling-activated Cl, current and several other channels. We previously showed that Kv1.3 and Cl, currents are needed for microglial cell proliferation and that Kv1.3 is important for the respiratory burst. Although their mechanisms of action are unknown, one general role for these channels is to maintain a negative Vm. An impediment to measuring Vm in non-excitable cells is that many have a very high electrical resistance, which makes them extremely susceptible to leak-induced depolarization. Using non-invasive Vm -sensitive dyes, we show for the first time that the membrane resistance of microglial cells is several gigaohms; much higher than the seal resistance during patch-clamp recordings. Surprisingly, we observed that small current injections can evoke large Vm oscillations in some microglial cells, and that injection of sinusoidal currents of varying frequency exposes a strong intrinsic electrical resonance in the 5- to 20-Hz frequency range in all microglial cells tested. Using a dynamic current clamp that we developed to actively compensate for the damage done by the patch-clamp electrode, we found that the Vm oscillations and resonance were more prevalent and larger. Both types of electrical behaviour required Kv1.3 channels, as they were eliminated by the Kv1.3 blocker, agitoxin-2. To further determine how the ion currents integrate in these cells, voltage-clamp recordings from microglial cells displaying these behaviours were used to analyse the biophysical properties of the Kv1.3, Kir and Cl, currents. A mathematical model that incorporated only these three currents reproduced the observed Vm oscillations and electrical resonance. Thus, the electrical behaviour of this ,non-excitable' cell type is much more complex than previously suspected, and might reflect a more common oversight in high resistance cells. [source]

Voltage-activated proton currents in human lymphocytes

THE JOURNAL OF PHYSIOLOGY, Issue 1 2002
Tom Schilling
Voltage-activated proton currents are reported for the first time in human peripheral blood T and B lymphocytes and in the human leukaemic T cell line Jurkat E6-1. The properties of H+ currents studied using tight-seal voltage-clamp recording techniques were similar in all cells. Changing the pH gradient by one unit caused a 47 mV shift in the reversal potential, demonstrating high selectivity of the channels for protons. H+ current activation upon membrane depolarisation had a sigmoidal time course that could be fitted by a single exponential function after a brief delay. Increasing pHo shifted the activation threshold to more negative potentials, and increased both the H+ current amplitude and the rate of activation. In lymphocytes studied at pHi 6.0, the activation threshold was more negative and the H+ current density was three times larger than at pHi 7.0. Increasing the intracellular Ca2+ concentration to 1 ,m did not change H+ current amplitude or kinetics detectably. Extracellularly applied Zn2+ and Cd2+ inhibited proton currents, slowing activation and shifting the voltage-activation curve to more positive potentials. The H+ current amplitude was 100 times larger in CD19+ B lymphocytes and in Jurkat E6-1 cells than in CD3+ T lymphocytes. Following stimulation with the phorbol ester PMA, the H+ current density in peripheral blood T lymphocytes and Jurkat T cells increased. In contrast, the H+ current density of phorbol ester (PMA)-stimulated B lymphocytes was reduced and activation became slower. The pattern of expression of H+ channels in lymphocytes appears well suited to their proposed role of charge compensation during the respiratory burst. [source]

Prebiotics in aquaculture: a review

AQUACULTURE NUTRITION, Issue 2 2010
E. RINGØ
Abstract A prebiotic is a non-digestible food ingredient that beneficially affects the host by selectively stimulating the growth and/or the activity of one or a limited number of bacteria in the colon. Despite the potential benefits to health and performance as noted in various terrestrial animals, the use of prebiotics in the farming of fish and shellfish has been less investigated. The studies of prebiotics in fish and shellfish have investigated the following parameters: effect on growth, feed conversion, gut microbiota, cell damage/morphology, resistance against pathogenic bacteria and innate immune parameters such as alternative complement activity (ACH50), lysozyme activity, natural haemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity. This review discusses the results from these studies and the methods used. If the use of prebiotics leads to health responses becoming more clearly manifested in fish and shellfish, then prebiotics might have the potential to increase the efficiency and sustainability of aquaculture production. However, large gaps of knowledge exist. To fully conclude on the effects of adding prebiotics in fish diets, more research efforts are needed to provide the aquaculture industry, the scientific community, the regulatory bodies and the general public with the necessary information and tools. [source]

Dietary vitamin E requirement of the red drum Sciaenops ocellatus

AQUACULTURE NUTRITION, Issue 3 2009
L.I. PENG
Abstract A 12-week feeding trial was conducted to establish the minimum dietary vitamin E requirement of juvenile red drum by broken-line regression analysis. The semi-purified basal diet was supplemented with 10, 20, 30, 40, 60 or 80 IU vitamin E kg,1 as all-rac -,-tocopheryl acetate. Juvenile red drum were conditioned by feeding the basal diet for 8 weeks prior to the feeding trial to reduce whole-body vitamin E levels. Then, fish initially averaging 12.2 ± 0.4 g fish,1 (mean ± SD) were fed the experimental diets at a rate approaching apparent satiation for 12 weeks. Weight gain and feed efficiency responses of fish fed diets were significantly (P < 0.01) altered by the level of vitamin E supplementation but not strictly in a dose-dependent manner. Vitamin E concentrations in liver and plasma also were significantly (P < 0.001) influenced by dietary vitamin E level. Plasma ascorbic acid in fish fed the basal diet tended (P = 0.066) to be lower than in fish fed diets containing the various levels of vitamin E. In addition, fish fed the basal diet showed edema in the heart, while fish fed all other diets were normal. Fish fed 60 or 80 IU all-rac -,-tocopheryl acetate kg,1 diet had significantly higher respiratory burst of head kidney macrophages than fish fed all other diets, although dietary effects on hematocrit and neutrophil oxidative radical production were not significant. The minimum dietary vitamin E requirement of juvenile red drum was established based on broken-line regression of liver thiobarbituric acid reactive substances to be 31 mg all-rac -,-tocopheryl acetate kg,1 diet. [source]

Probiotic effect of Bacillus NL110 and Vibrio NE17 on the survival, growth performance and immune response of Macrobrachium rosenbergii (de Man)

AQUACULTURE RESEARCH, Issue 9 2010
K M Mujeeb Rahiman
Abstract Eight hundred and eighty-five strains of bacterial isolates from various samples associated with the natural habitat of Macrobrachium rosenbergii were screened for their probiotic potential. Two putative probionts namely Bacillus NL110 and Vibrio NE17 isolated from the larvae and egg samples, respectively, were selected for experimental studies and were introduced to the juveniles of M. rosenbergii (0.080±0.001 g) through different modes such as through feed, water and both. The probiotic potential of the above bacteria in terms of improvements in water quality, growth, survival, specific growth rate (SGR), feed conversion ratio and immune parameters was evaluated. The treatment groups showed a significant improvement in SGR and weight gain (P<0.001). Survival among different treatment groups was better than that in the control group. There were also significant improvements in the water quality parameters such as the concentration of nitrate and ammonia in the treatment groups (P<0.05). Improvements in immune parameters such as the total haemocyte count (P<0.05), phenoloxidase activity and respiratory burst were also significant (P<0.001). It is concluded that screening of the natural microflora of cultured fish and shellfish for putative probionts might yield probiotic strains of bacteria that could be utilized for an environment-friendly and organic mode of aquaculture. [source]

Comparative study of the intracellular superoxide anion production in different penaeid species through the NBT-reduction assay

AQUACULTURE RESEARCH, Issue 7 2010
Cristhiane Guertler
Abstract The capacity of reactive oxygen intermediates production upon haemocyte stimulation is one of the most important immunoparameter utilized to assess the health status in cultivated shrimps. In the present study, we compared oxidative stress potential, by measuring the superoxide anion production in three penaeid shrimps: two wild Atlantic species, the pink shrimp Farfantepenaeus paulensis and the white shrimp Litopenaeus schmitti and one cultivated Pacific species, the white shrimp, Litopenaeus vannamei, through the nitro-blue-tetrazolium-reduction assay. We also proposed an optimized experimental protocol for this assay, that produces rapid and consistent results with low levels of basal superoxide anion (O2,) production by unstimulated haemocytes and high levels of this oxygen radical after cell stimulation. Among the different cell elicitors used (zymosan, laminarin, lipopolysaccharide and phorbol myristate acetate), laminarin (,-1,3-glucans , 2 mg mL,1) was the most potent cell activator for the haemocytes of all three penaeids and we recommend this immunostimulant to routinely evaluate shrimp respiratory burst. In general terms, the most elevated levels of O2, production, after cell stimulation with microbial components, were detected in L. schmitti. Interestingly, the stimulation profile of the haemocytes of L. vannamei was more similar to F. paulensis, than to L. schmitti, which is more phylogenetically related. [source]

Comparison of continuous and batch feeding systems on maturation, biochemical composition and immune variables of the oyster Crassostrea corteziensis (Hertlein 1951)

AQUACULTURE RESEARCH, Issue 4 2009
Miguel A Hurtado
Abstract Two feeding systems for maturing oysters were compared, one a continuous feeding system and the other a batch system in which the whole microalgal ration was supplied once daily. The maturation diet consisted in Isochrysis galbana (T-ISO) complemented with an enriched lipid emulsion. Survival and growth did not differ between the feeding systems after 3 weeks of conditioning. Maturation, biochemical composition, fatty acids in membranes and reserves, digestive enzymes activities and immune parameters in Crassostrea corteziensis were analysed. Only oysters fed using the once-daily system had vitellogenic oocytes, whereas the gonad of oysters fed using a continuous-drip system remained immature. Total and differential haemocyte counts were similar between both the systems, but respiratory burst was significantly higher in oysters fed using the once-daily system. Amylase, lipase and trypsin activities in oyster's digestive gland were similar between both the feeding systems. Total lipids, however, differed significantly in oyster tissue in relation to feeding system, with highest level in those fed using the once-daily system, but fatty acid composition in reserves and membrane were similar. No differences were found for biochemical parameters in haemolymph. These results suggest that feeding oysters using a batch, once-daily system allows more rapid initial gonad maturation without affecting general physiological condition and growth. [source]

Could a diet enriched with n-3 highly unsaturated fatty acids be considered a promising way to enhance the immune defences and the resistance of Penaeid prawns to environmental stress?

AQUACULTURE RESEARCH, Issue 2 2001
L Chim
Abstract The prawn Penaeus stylirostris (Stimpson), when fed for 28 days with n-3 highly unsaturated fatty acid (HUFA)-enriched feed pellets, demonstrated an enhanced resistance to variations in environmental parameters (a decrease in temperature and salinity over a 4-day period from 28 °C to 17 °C and from 35, to 10, respectively) and an improvement in their immune defence potential, i.e. increased agglutination titre of plasma and increased respiratory burst of haemocytes. [source]

Neutrophil dysfunction in a family with a SAPHO syndrome,like phenotype

ARTHRITIS & RHEUMATISM, Issue 10 2008
Polly J. Ferguson
SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis, osteitis) is an inflammatory disorder of the bone, skin, and joints. We describe a family with multiple affected members who segregate a SAPHO syndrome,like phenotype, and we report the results of neutrophil studies and candidate gene analysis. We obtained written informed consent and a family history and reviewed medical records. We collected DNA and sequenced candidate genes, and we performed functional studies on neutrophils isolated from the proband and her mother. The pedigree segregated chronic osteomyelitis and cutaneous inflammation in a pattern that suggested an autosomal-dominant disorder. No coding sequence mutations were detected in PSTPIP1,PSTPIP2, LPIN2, SH3BP2, or NCF4. Analysis of neutrophil function in the proband, including nitroblue tetrazolium tests, myeloperoxidase assays, neutrophil chemotaxis, and neutrophil chemotaxis assays, revealed no identifiable abnormalities. However, an abnormality in the luminol, but not the isoluminol, respiratory burst assays following stimulation with phorbol myristate acetate (PMA) was detected in neutrophils isolated from the affected proband. Internal oxidant production was also reduced in the proband and her mother when neutrophils were treated with fMLP with or without platelet-activating factor, PMA alone, or tumor necrosis factor , alone. This family segregates a disorder characterized by chronic inflammation of the skin and bone. Functional differences in neutrophils exist between affected individuals and controls. The biologic significance of this defect remains unknown. Identification of the gene defect will help identify an immunologic pathway that, when dysregulated, causes inflammation of the skin and bone. [source]

Macrophage Stimulating Protein (MSP) evokes superoxide anion production by human macrophages of different origin

BRITISH JOURNAL OF PHARMACOLOGY, Issue 6 2001
Sandra Brunelleschi
Macrophage Stimulating Protein (MSP), a serum factor related to Hepatocyte Growth Factor, was originally discovered to stimulate chemotaxis of murine resident peritoneal macrophages. MSP is the ligand for Ron, a member of the Met subfamily of tyrosine kinase receptors. The effects of MSP on human macrophages and the role played in human pathophysiology have long been elusive. We show here that human recombinant MSP (hrMSP) evokes a dose-dependent superoxide anion production in human alveolar and peritoneal macrophages as well as in monocyte-derived macrophages, but not in circulating human monocytes. Consistently, the mature Ron protein is expressed by the MSP responsive cells but not by the unresponsive monocytes. The respiratory burst evoked by hrMSP is quantitatively higher than the one induced by N-formylmethionyl-leucyl-phenylalanine and similar to phorbol myristate acetate-evoked one. To investigate the mechanisms involved in NADPH oxidase activation, leading to superoxide anion production, different signal transduction inhibitors were used. By using the non selective tyrosine kinase inhibitor genistein, the selective c-Src inhibitor PP1, the tyrosine phosphatase inhibitor sodium orthovanadate, the phosphatidylinositol 3-kinase inhibitor wortmannin, the p38 inhibitor SB203580, the MEK inhibitor PD098059, we demonstrate that hrMSP-evoked superoxide production is mediated by tyrosine kinase activity, requires the activation of Src but not of PI 3-kinase. We also show that MAP kinase and p38 signalling pathways are involved. These results clearly indicate that hrMSP induces the respiratory burst in human macrophages but not in monocytes, suggesting for the MSP/Ron complex a role of activator as well as of possible marker for human mature macrophages. British Journal of Pharmacology (2001) 134, 1285,1295; doi:10.1038/sj.bjp.0704356 [source]

Pityriarubins, Novel Highly Selective Inhibitors of Respiratory Burst from Cultures of the Yeast Malassezia furfur: Comparison with the Bisindolylmaleimide Arcyriarubin A