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Phagocytic Capacity (phagocytic + capacity)
Selected AbstractsEffect of preoperative prophylaxis with filgrastim in cancer neck dissectionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2000Wenisch Background Cancer surgery is known to lead to a deterioration in host defence mechanisms and an increase in susceptibility to infection after operation. Filgrastim enhances important antimicrobial functions of neutrophils including chemotaxis, phagocytosis and oxidative killing mechanisms. Methods The effects of additional (all patients received perioperative 3 , 25 mg kg,1 cefotiam and 1 , 20 mg kg,1 metronidazole) preoperative prophylaxis with filgrastim (5 ,g kg,1 12 h prior to surgery plus 5 ,g kg,1 0 h prior to surgery) on neutrophil phagocytosis and reactive oxygen radical production and postoperative infections in 24 patients undergoing cancer neck dissection were studied. Phagocytic capacity was assessed by measuring the uptake of fluorescein isothiocyanate-labelled Escherichia coli and Staphylococcus aureus by flow cytometry. Reactive oxygen generation after phagocytosis was estimated by determining the amount of dihydrorhodamine 123 converted to rhodamine 123, intracellularly. Results In the filgrastim-treated patients a higher neutrophil phagocytic capacity was seen intraoperatively, and 1,5 days postoperative, but not prior to surgery. Reactive oxygen radical production was significantly higher in filgrastim-treated patients prior to surgery, intraoperative and postoperative (1,5 days). 2/12 (17%) patients had postoperative infections in the filgrastim group and 9/12 (75%) patients had infections in the placebo group (P < 0.001). In particular, wound infections were recorded more often in the placebo group (1/12 vs. 6/12; P = 0.004). Conclusion We conclude that filgrastim enhances perioperative neutrophil function and could be useful in the prophylaxis of postoperative wound infections in patients undergoing cancer neck dissection. [source] Phagocytic capacity of leucocytes in sheep mammary secretions following weaningJOURNAL OF ANATOMY, Issue 5 2002Liliana Tatarczuch Abstract Lactating animals are particularly susceptible to mastitis during the early stages of mammary gland involution following weaning. In this study we compared the phagocytic capacity of cells collected from sheep mammary secretions at different stages of involution. The ability of neutrophils and macrophages to ingest latex beads in an in vitro phagocytosis assay was found to be dependent on how heavily the phagocytes were loaded with milk constituents. There was a decline in the phagocytic capacity of neutrophils from 1 to 2 days after weaning, while macrophages collected from fully involuted glands were more effective phagocytes compared with earlier stages (7,15 days) of involution. In addition, dendritic cells present in fully involuted mammary gland secretions (30 days after weaning) were highly phagocytic. These studies demonstrate that neutrophils and macrophages in sheep mammary secretions at early stages of involution are incapacitated, and as such may compromise the immune status of the mammary gland. [source] Receptor-mediated phagocytosis of rat macrophages is regulated differentially for opsonized particles and non-opsonized particles containing ,-glucanIMMUNOLOGY, Issue 2 2001Jonathan S. Reichner Summary Experiments were conducted to test the hypothesis that opsonic and non-opsonic phagocytic capacities are differentially regulated by resting and wound-derived macrophages. Furthermore, the phagocytosis of non-opsonized zymosan and ,-glucan particles was quantified to determine whether cells differentially regulate non-opsonic lectinophagocytosis in accordance with the carbohydrate composition of the ligand. In that regard, wound macrophages exhibited profound differential regulation in lectinophagocytosis with a seven-fold increase in phagocytosis of ,-glucan particles following overnight culture but with a relatively modest increase in internalization of mannan-containing zymosan. Cultured peritoneal macrophages increased uptake of both particles similarly. Upon activation with interferon-,/lipopolysaccharide (IFN-,/LPS), wound macrophages selectively suppressed ,-glucan ingestion, while phagocytosis of zymosan particles was unaffected. Lectinophagocytosis was decreased in activated peritoneal macrophages regardless of particle composition and was due in part to a nitric oxide-dependent mechanism which was without a role in regulation of wound macrophage lectinophagocytosis. Overnight culture of wound macrophages suppressed their capacity for opsonic-dependent phagocytosis independently of activation, whereas suppression of phagocytosis by peritoneal macrophages was activation-dependent. Regulation of all three phagocytic pathways was achieved distinctly by peritoneal and wound-derived macrophages, with changes found in the percentage of resident peritoneal macrophages capable of phagocytosis, whereas the phagocytic capacity of wound macrophages was primarily affected by the number of particles ingested by individual cells. Taken together, these findings demonstrate that the differential regulation of phagocytic pathways encompasses the nature of the phagocytic particle, the site from which macrophages are obtained, their response to activating agents and the mechanism through which the cell population alters its phagocytic potential. [source] Effect of preoperative prophylaxis with filgrastim in cancer neck dissectionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2000Wenisch Background Cancer surgery is known to lead to a deterioration in host defence mechanisms and an increase in susceptibility to infection after operation. Filgrastim enhances important antimicrobial functions of neutrophils including chemotaxis, phagocytosis and oxidative killing mechanisms. Methods The effects of additional (all patients received perioperative 3 , 25 mg kg,1 cefotiam and 1 , 20 mg kg,1 metronidazole) preoperative prophylaxis with filgrastim (5 ,g kg,1 12 h prior to surgery plus 5 ,g kg,1 0 h prior to surgery) on neutrophil phagocytosis and reactive oxygen radical production and postoperative infections in 24 patients undergoing cancer neck dissection were studied. Phagocytic capacity was assessed by measuring the uptake of fluorescein isothiocyanate-labelled Escherichia coli and Staphylococcus aureus by flow cytometry. Reactive oxygen generation after phagocytosis was estimated by determining the amount of dihydrorhodamine 123 converted to rhodamine 123, intracellularly. Results In the filgrastim-treated patients a higher neutrophil phagocytic capacity was seen intraoperatively, and 1,5 days postoperative, but not prior to surgery. Reactive oxygen radical production was significantly higher in filgrastim-treated patients prior to surgery, intraoperative and postoperative (1,5 days). 2/12 (17%) patients had postoperative infections in the filgrastim group and 9/12 (75%) patients had infections in the placebo group (P < 0.001). In particular, wound infections were recorded more often in the placebo group (1/12 vs. 6/12; P = 0.004). Conclusion We conclude that filgrastim enhances perioperative neutrophil function and could be useful in the prophylaxis of postoperative wound infections in patients undergoing cancer neck dissection. [source] Receptor-mediated phagocytosis of rat macrophages is regulated differentially for opsonized particles and non-opsonized particles containing ,-glucanIMMUNOLOGY, Issue 2 2001Jonathan S. Reichner Summary Experiments were conducted to test the hypothesis that opsonic and non-opsonic phagocytic capacities are differentially regulated by resting and wound-derived macrophages. Furthermore, the phagocytosis of non-opsonized zymosan and ,-glucan particles was quantified to determine whether cells differentially regulate non-opsonic lectinophagocytosis in accordance with the carbohydrate composition of the ligand. In that regard, wound macrophages exhibited profound differential regulation in lectinophagocytosis with a seven-fold increase in phagocytosis of ,-glucan particles following overnight culture but with a relatively modest increase in internalization of mannan-containing zymosan. Cultured peritoneal macrophages increased uptake of both particles similarly. Upon activation with interferon-,/lipopolysaccharide (IFN-,/LPS), wound macrophages selectively suppressed ,-glucan ingestion, while phagocytosis of zymosan particles was unaffected. Lectinophagocytosis was decreased in activated peritoneal macrophages regardless of particle composition and was due in part to a nitric oxide-dependent mechanism which was without a role in regulation of wound macrophage lectinophagocytosis. Overnight culture of wound macrophages suppressed their capacity for opsonic-dependent phagocytosis independently of activation, whereas suppression of phagocytosis by peritoneal macrophages was activation-dependent. Regulation of all three phagocytic pathways was achieved distinctly by peritoneal and wound-derived macrophages, with changes found in the percentage of resident peritoneal macrophages capable of phagocytosis, whereas the phagocytic capacity of wound macrophages was primarily affected by the number of particles ingested by individual cells. Taken together, these findings demonstrate that the differential regulation of phagocytic pathways encompasses the nature of the phagocytic particle, the site from which macrophages are obtained, their response to activating agents and the mechanism through which the cell population alters its phagocytic potential. [source] Phagocytic capacity of leucocytes in sheep mammary secretions following weaningJOURNAL OF ANATOMY, Issue 5 2002Liliana Tatarczuch Abstract Lactating animals are particularly susceptible to mastitis during the early stages of mammary gland involution following weaning. In this study we compared the phagocytic capacity of cells collected from sheep mammary secretions at different stages of involution. The ability of neutrophils and macrophages to ingest latex beads in an in vitro phagocytosis assay was found to be dependent on how heavily the phagocytes were loaded with milk constituents. There was a decline in the phagocytic capacity of neutrophils from 1 to 2 days after weaning, while macrophages collected from fully involuted glands were more effective phagocytes compared with earlier stages (7,15 days) of involution. In addition, dendritic cells present in fully involuted mammary gland secretions (30 days after weaning) were highly phagocytic. These studies demonstrate that neutrophils and macrophages in sheep mammary secretions at early stages of involution are incapacitated, and as such may compromise the immune status of the mammary gland. [source] The immunomodulatory effects of levamisole on the nonspecific immune system of Atlantic salmon, Salmo salar L.JOURNAL OF FISH DISEASES, Issue 6 2000V L Findlay Sea water-adapted Atlantic salmon, Salmo salar L., were given a 2-h bath in a 2.5 mg L,1 levamisole (as levamisole hydrochloride) solution in fresh-water. Following bathing, the fish were held in full salinity sea water for 2 weeks before being subjected to a number of immunological assays. Heightened activity of the nonspecific defence system was demonstrated by increases in phagocytic index, phagocytic capacity and phagocytic activity, increased levels of the reactive oxygen intermediate, superoxide anion, and an increased lytic activity of both the mucus and the serum. These results indicate that levamisole is effective in augmenting parts of the nonspecific defence system of Atlantic salmon. This is the first record of the use and efficacy of levamisole as an immunomodulator in Atlantic salmon. [source] Acute Alcohol Intoxication During Hemorrhagic Shock: Impact on Host Defense From InfectionALCOHOLISM, Issue 4 2004K. L. Zambell Abstract: Background: Acute alcohol intoxication is a frequent underlying condition associated with traumatic injury. Our studies have demonstrated that acute alcohol intoxication significantly impairs the immediate hemodynamic, metabolic, and inflammatory responses to hemorrhagic shock. This study investigated whether acute alcohol intoxication during hemorrhagic shock would alter the outcome from an infectious challenge during the initial 24 hr recovery period. Methods: Chronically catheterized male Sprague Dawley® rats were randomized to acute alcohol intoxication (EtOH; 1.75 g/kg bolus followed by a constant 15 hr infusion at 250,300 mg/kg/hr) or isocaloric isovolemic dextrose infusion (dex; 3 ml + 0.375 ml/hr). EtOH and dex were assigned to either fixed-volume (50%) hemorrhagic shock followed by fluid resuscitation with Ringer's lactate (EtOH/hem, dex/hem) or sham hemorrhagic shock (EtOH/sham, dex/sham). Indexes of circulating neutrophil function (apoptosis, phagocytosis, oxidative burst) were obtained at baseline, at completion of hemorrhagic shock, and at the end of fluid resuscitation. Bacterial clearance, lung cytokine expression, and myeloperoxidase activity were determined at 6 and 18 hr after an intratracheal challenge with Klebsiella pneumoniae (107 colony-forming units). Results: Mean arterial blood pressure was significantly lower in acute alcohol intoxication-hemorrhagic shock animals throughout the hemorrhagic shock. In sham animals, acute alcohol intoxication alone did not produce significant changes in neutrophil apoptosis or phagocytic activity but significantly suppressed phorbol myristic acid (PMA)-stimulated oxidative burst. Hemorrhagic shock produced a modest increase in neutrophil apoptosis and suppression of neutrophil phagocytic capacity but significantly suppressed PMA-stimulated oxidative burst. Acute alcohol intoxication exacerbated the hemorrhagic shock-induced neutrophil apoptosis and the hemorrhagic shock-induced suppression of phagocytosis without further affecting PMA-stimulated oxidative burst. Fluid resuscitation did not restore neutrophil phagocytosis or oxidative burst. Acute alcohol intoxication decreased (,40%) 3-day survival from K. pneumoniae in hemorrhagic shock animals, impaired bacterial clearance during the first 18 hr postinfection, and prolonged lung proinflammatory cytokine expression. Conclusions: These results demonstrate that the early alterations in metabolic and inflammatory responses to hemorrhagic shock produced by acute alcohol intoxication are associated with neutrophil dysfunction and impaired host response to a secondary infectious challenge leading to increased morbidity and mortality. [source] Blood Lymphocyte Subpopulations, Neutrophil Phagocytosis and Proteinogram During Late Pregnancy and Postpartum in MaresREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2008R Agrícola Contents The aim of this study was to evaluate peripheral blood lymphocyte subpopulations, neutrophil phagocytic capacity and proteinogram characteristics in mares, during the last trimester of pregnancy and in postpartum. Measurement of phagocytosis and quantification of T-lymphocyte subsets were done by flow cytometry. Quantification of T-lymphocyte subsets was performed with monoclonal antibodies specific for CD2, CD3, CD4 and CD8 cell markers. Natural killer and B-cell counts were estimated mathematically. Serum proteinogram was obtained by electrophoresis. No significant differences were observed between gestation and postpartum on CD4+, CD8+ and NK+ lymphocyte subsets, CD4 : CD8 ratio and phagocytosis. The percentage of cells expressing CD3 (64.2 ± 1.8) and CD2 (68.4 ± 1.7) (Mean ± SEM) was reduced during gestation vs postpartum (69.7 ± 1.5 and 73.8 ± 1.4 respectively) (p < 0.05). During pregnancy, CD19+ (31.6 ± 1.7) was higher than in postpartum (26.2 ± 1.4) (p < 0.05). Total T cells (2911 ± 227 cells/,l), T helper cells (2144 ± 169 cells/,l) and T-cytotoxic cells (767 ± 68 cells/,l) were depressed in pregnancy, when compared with postpartum (4093 ± 337 cells/,l; 3004 ± 276 cells/,l; 1089 ± 94 cells/,l respectively) (p < 0.01). Total white blood cell count was reduced during pregnancy (8815 ± 427 cells/,l) with respect to postpartum (10742 ± 446 cells/,l) (p < 0.01), while neutrophil count did not change. Total proteins, albumin, ,1,,2,,1, ,2, , globulins and albumin : globulin did not differ. Our results suggest that the physiological immune depression occurring in mares, during gestation might be due to T-helper and T-cytotoxic lymphocytes reduction. [source] Haematologic and immunologic parameters of bullfrogs, Lithobates catesbeianus, fed probioticsAQUACULTURE RESEARCH, Issue 7 2010Danielle de Carla Dias Abstract The effects of two probiotics (P1,Lactobacillus acidophilus, Bifidobacterium bifidum and Enterococcus faecium and P2,Bacillus subtilis) supplemented to commercial feed (40% crude protein) on the haematological and immunological parameters of the bullfrog Lithobates catesbeianus were studied. Two doses of each probiotic (5 and 10 g kg,1 of food) were added to the diets and fed to frogs, totalling five treatments over 112 days. Haematological analyses consisted of total and differential leucocyte counts, erythrocyte and thrombocyte counts, haematocrit, haemoglobin levels and RBC indices (mean corpuscular volume, mean corpuscular haemoglobin , and mean corpuscular haemoglobin concentration) and the immunological parameters included phagocytic capacity and phagocytic index of peritoneal phagocytes. The results showed that the probiotics did not significantly influence any of the haematological parameters measured. However, immunological assays showed that the probiotics had an immunostimulating effect. The greatest effects were seen with probiotic P1 fed at a dose of 10 g kg,1 of diet and probiotic P2 fed at 5 g kg,1 of diet. [source] Haemocyte responses of blue mussels (Mytilus edulis L.) transferred from a contaminated site to a reference site: can the immune system recuperate?AQUACULTURE RESEARCH, Issue 10 2005Elise Mayrand Abstract We measured the haemocyte responses of the blue mussels, Mytilus edulis (L.), transferred from a contaminated site (Pictou, NS, Canada) to a relatively clean site (Richibucto, NB, Canada) to assess the capacity of recovery of haemocytes. Mussels from each site were caged in Richibucto. Haemocyte count, phagocytic capacity, mortality and mitotic activity were measured 1, 4 and 9 days after caging. At the end of the 9-day exposure, 15 mussels from each site were evaluated for their capacity to clear bacteria, 36 h after having been injected with Listonella anguillarum. Before caging, mussels native to Pictou had higher haemocyte counts and mitotic capacity and lower phagocytic capacity than mussels native to Richibucto. However, after the mussels had been caged and transferred from Pictou to Richibucto and as the exposure progressed, phagocytic capacity slowly rose to the level measured at Richibucto, the haemocyte count lowered and haemocyte mortality and mitotic activity rose. At the end of the experiment, bacteria clearing was more efficient in mussels originating from Richibucto than in those transferred from Pictou. This study shows a partial recovery of the haemocyte responses in mussels originating from an industrialized site and transferred to an unindustrialized environment, and illustrates the importance of linking descriptors of haemocyte activity with immunocompetency. [source] Determination of intracellular efficacies of azithromycin against Leishmania major infection in human neutrophils in vitroCELL BIOCHEMISTRY AND FUNCTION, Issue 1 2003Mehmet Tanyuksel Abstract Azithromycin is one of a new class of antibiotics known as azalides. Azithromycin has high tissue affinity and this feature is thought to be due to the presence of two basic tertiary amine groups. Leishmania major, one of the causative agents of cutaneous leishmaniosis, is an obligate intracellular parasite. In this in vitro study, the potential anti-leishmanial effect of azithromycin upon intracellular forms namely the amastigote of L. major in mice peritoneal macrophages was investigated. L. major promastigotes were propagated in RPMI-1640 supplemented with 20% fetal calf serum in the log phase. The percentage of phagocytosis and microbiacidal activity of azithromycin on macrophages was assessed in the control and study groups by fluorescence microscopy, using acridine orange. Our results showed that at all the concentrations used (0.05, 0.1, 0.3, 0.6,,g,ml,1) azithromycin had no inhibitory effect on the phagocytic capacity of mouse peritoneal macrophages. Although no significant difference was observed for leishmaniacidal activity between the study and the control groups at a concentration of 0.05,,g,ml,1 (p>0.05), a significant (p<0.05) increase in leishmaniacidal activity was detected at 0.1, 0.3 and 0.6,,g,ml,1. As a result, azithromycin does not provide any contribution to the phagocytosis of L. major promastigotes in macrophages in vitro, but it increases the intracellular killing rates of amastigotes. These results suggest that it has a potential anti-leishmanial effect, and may provide a significant advantage in the treatment of the disease. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||||||||