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Respiratory Burst Activity (respiratory + burst_activity)
Selected AbstractsRespiratory burst activity of polymorphonuclear cells is dependent on the cell preparation techniqueACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2003J. 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] Influence of Vitamin E Source and Dietary Supplementation Level on Production Performance of Sunshine Bass, Morone chrysops , × Morone saxatilis ,, Fillet Tocopherol Content, and Immunocompetency during Stress and Bacterial ChallengeJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2008Jesse T. Trushenski We evaluated the effects of dietary vitamin E concentration and source on production performance and immunocompetency of sunshine bass, Morone chrysops × Morone saxatilis, following stress and disease challenge. Four diets were formulated to contain requisite levels (1×) or five times (5×) the vitamin E requirement of sunshine bass as met by synthetic vitamin E (SYNE) or natural source vitamin E (NSVE). Each diet was fed to juvenile sunshine bass for 8 wk prior to experimental challenges. Replicate tanks within each dietary treatment were challenged with stressor exposure (chasing with dip net), incidental Flavobacterium columnare exposure, or both; control groups were not challenged. Pathogen and/or stressor exposure largely resulted in significant reductions in immunological performance. Although significant independent dietary effects were not observed among immunological parameters, suppression of complement and macrophage respiratory burst activities was numerically lower within the 5× NSVE treatment. Production performance was largely unaffected by dietary vitamin E source or level. Fillet ,-tocopherol concentration was significantly higher among fish fed the 5× diets (40.7/41.6 vs. 12.2/14.5 ,g/g dry tissue for 1× diets); however, the dietary concentration required to achieve these levels was lower for NSVE. Although super-requirement levels of either source of vitamin E were apparently beneficial, NSVE was effective at ,50% lower supplementation levels. [source] Efficacy of in-feed probiotics against Aeromonas bestiarum and Ichthyophthirius multifiliis skin infections in rainbow trout (Oncorhynchus mykiss, Walbaum)JOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2008N. Pieters Abstract Aims:, The aim of this study was to assess the efficacy of in-feed probiotics as a preventive measure against skin infections caused by Aeromonas bestiarum and Ichthyophthirius multifiliis (Ich) in rainbow trout. Methods and Results:, Fin rot was induced in fish by intradermal injection with 0·1 ml volumes containing 105 cells per ml A. bestiarum at the base of the dorsal fin. Ich infections resulted from immersion in Ich-contaminated water. Each probiotic was administered orally [108 cells per g feed for GC2 (Aeromonas sobria) and 1010 cells per g feed for BA211 (Brochothrix thermosphacta)] for 14 days. Results showed that, after challenge with A. bestiarum, probiotics GC2 and BA211 led to 76% and 88% survival, respectively, in contrast to 22% survival for controls. Fish fed with probiotic GC2 had 100% survival after challenge with Ich compared with 2% for probiotic BA211 and 0% for controls. Analysis of innate immune responses revealed that probiotic GC2 promoted higher phagocytic activity, whereas probiotic BA211 led to enhanced respiratory burst activity. Conclusion:, Of the two probiotics examined, GC2 was more effective in protecting against both fin rot and Ich. Each probiotic appeared to stimulate different pathways within the innate immune system. Significance and Impact of the Study:, This is the first demonstration that probiotics can protect fish against surface infections. Furthermore, this is the first time a probiotic has been shown to protect against a eucaryotic pathogen, namely I. multifiliis. [source] Microbial levan in the diet of Labeo rohita Hamilton juveniles: effect on non-specific immunity and histopathological changes after challenge with Aeromonas hydrophilaJOURNAL OF FISH DISEASES, Issue 9 2008S K Gupta Abstract A 60-day feeding trial was conducted to study the immuno-protective effect of microbial levan on Labeo rohita juveniles challenged with Aeromonas hydrophila. Six purified diets were prepared with different levels of microbial levan: control (no levan), T1 (Basal + 0.25%), T2 (Basal + 0.50%), T3 (Basal + 0.75%), T4 (Basal + 1%) and T5 (Basal + 1.25%), fed to six groups of fish in triplicate. Among the treatment groups the haemoglobin content and total leucocyte count were increased with a dietary supplementation of levan at 1% or more. An increasing trend for total erythrocyte count was observed with increasing level of dietary levan. Lower levan-supplemented groups showed a higher albumin/globulin ratio. As the levan supplementation was increased, there was a gradual increase in serum lysozyme activity and respiratory burst activity [nitroblue tetrazolium (NBT) assay] reduction values. The highest lysozyme activity and NBT were observed in the T5 group although this was similar to the T4 group (P > 0.05). No significant histo-architectural changes were associated with dietary levan levels. After challenge with A. hydrophila, moderately degenerated hepatocytes, oedema and leucocytic infiltration in parenchymatous tissues, and extensive haemorrhage and haemosiderosis in the kidney were observed in the control group. However, the T5 group supplemented with 1.25% levan showed infiltrating leucocytes in the liver while the kidney showed only moderate degeneration of renal tubules. The relative survival per cent of juveniles after challenge with A. hydrophila was the highest in the T5 group followed by T4. This suggests that microbial levan at 1.25% can be used as dietary immunostimulant for L. rohita juveniles. [source] Effect of dietary administration of Porphyridium cruentum on the respiratory burst activity of sole, Solea senegalensis (Kaup), phagocytesJOURNAL OF FISH DISEASES, Issue 7 2008P Díaz-Rosales Abstract The stimulatory effect of the red microalga Porphyridium cruentum on respiratory burst activity of sole phagocytes was evaluated in vivo. Oral administration of a diet supplemented with lyophilized P. cruentum cells (10 g kg,1) stimulated respiratory burst activity after 4 weeks feeding in sole vaccinated with Photobacterium damselae subsp. piscicida bacterin. [source] Use of a probiotic to control lactococcosis and streptococcosis in rainbow trout, Oncorhynchus mykiss (Walbaum)JOURNAL OF FISH DISEASES, Issue 12 2005J Brunt Abstract From a comparison of 125 bacterial isolates recovered from the digestive tract of rainbow trout, Oncorhynchus mykiss, and carp, Cyprinus sp., a culture was obtained which was effective at preventing clinical disease caused by Lactococcus garvieae and Streptococcus iniae when used as a feed additive. The culture, Aeromonas sobria GC2, was incorporated into the feed and fed to rainbow trout (average weight = 20 g) for 14 days at a dose equivalent to 5 × 107 cells g,1 of feed. Whereas the untreated controls experienced losses of 75,100% when challenged intraperitoneally with L. garvieae and S. iniae, the probiotic-treated groups remained healthy with total mortalities of only 0,6%. Formalized and sonicated preparations of GC2 and cell-free supernatant fared less well. The mode of action reflected stimulation of innate immunity, namely an increased number of leucocytes and enhanced phagocytic and respiratory burst activity. [source] Evaluation of zinc supplementation in European sea bass (Dicentrarchus labrax) juvenile dietsAQUACULTURE RESEARCH, Issue 9 2010Eleni Fountoulaki Abstract This study aimed to investigate the effect of increased zinc dietary levels on the growth performance, feed utilization, immune status and induced wound healing in European sea bass (Dicentrarchus labrax). Fish weighing 10 g were fed five diets containing organic zinc at 30, 70, 110 and 150 mg kg,1 diet and one inorganic zinc source (zinc oxide) at 150 mg kg,1 diet for a period of 12 weeks. No significant (P>0.05) differences were found in the growth performance parameters (final weight, specific growth rate), immunological indices tested (respiratory burst activity in whole blood) and the wound-healing process. Zinc accumulation in the skin, vertebrae and liver increased significantly (P<0.01) with increased dietary zinc levels but not in muscle. The highest zinc concentrations were obtained in skin tissue, followed by vertebrae, liver and muscle tissue. Using the concentration of zinc in skin as a response criterion, broken-line analysis showed that the supplementation of 148 mg organic Zn kg,1 diet seemed to be the optimum dietary zinc supplementation level for sea bass juveniles. [source] Reduced post-operative neutrophil activation in liver transplant recipients suffering from post-hepatitic cirrhosisCLINICAL TRANSPLANTATION, Issue 6 2009Björn 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] | |||||||||||||