Phagocytic Activity Of Granulocytes Research Articles

Phagocytic activity of blood cells in diabetic risk probands and newly diagnosed type 1 diabetics.

The phagocytic activity of granulocytes and mononuclear blood cells was compared in probands at risk for insulin-dependent Type 1 diabetes mellitus and in newly diagnosed diabetics before and during short-term insulin treatment. Healthy persons without family history of Type 1 diabetes were used as controls. Furthermore, the relationship between phagocytic activity and the proportion on monocytes in the granulocyte- and mononuclear blood cell fractions was estimated. The phagocytic activity of the mononuclear cells from the risk subjects was reduced. This observation suggests that defective phagocytosis might be important in the pathogenesis of Type 1 diabetes. But the phagocytic activity of mononuclear cells from newly diagnosed diabetics was not severely impaired and was fully normal under insulin treatment. We found no differences in the phagocytic activity of the granulocytes between patients and healthy probands. The proportion of monocytes in the mononuclear cell fraction was significantly enhanced in newly diagnosed diabetics and remained high throughout the 6-month period of insulin therapy. We assume that the increased monocyte level and the phagocytic activity of mononuclear cells in diabetics are not related to each other. But the increased monocyte level could also be interpreted as a compensatory reaction against the impaired phagocytic activity observed in the risk probands.

Leukocytic responses of broilers following dietary contamination with deoxynivalenol and/or treatment by dietary selenium supplementation

1. This experiment was to investigate the effects of natural dietary contamination with a mycotoxin product (deoxynivalenol: DON) and/or with dietary selenised yeast (Se-yeast), on respiratory burst and phagocytic activity of granulocytes and the frequency of B- and T-lymphocytes in peripheral blood of broilers. 2. Sixty one-day-old chicks of both sexes were divided into 4 groups, each of 15 birds, fed on a control diet that contained 0·2 mg DON/kg and 0·4 mg Se/kg (CON group), a diet supplemented with 1 mg Se-yeast/kg (Se-yeast group), a diet contaminated with 3 mg DON/kg (DON group) or a diet contaminated with DON and supplemented with Se-yeast (DON plus Se-yeast group). 3. Blood samples collected from the birds at the age of 4 weeks showed that neither B- and T-cell numbers nor granulocytic respiratory burst were influenced by 3 mg DON/kg. Blood granulocyte phagocytic activity was not reduced by DON but numbers of heterophils were increased. In the DON plus Se yeast group phagocytic activity was the same as in the CON group. The Se-yeast and DON plus Se-yeast groups had increased numbers of CD3+, CD4+, and CD8+ T-cells as well as IgM+ B-cells in their blood compared to both CON and DON-groups. 4. The results show there is no significant effect of dietary DON up to 3 mg/kg on leukocytes apart from the compromised blood granulocytes phagocytic activity and increased numbers of heterophils. The increased numbers of B- and T-lymphocytes in blood of birds fed on diets with supplementation of organic Se indicates some positive effects of this essential microelement on poultry lymphoid cells.

The interaction of urinary tract infection and renal insufficiency

Urinary tract infections (UTIs) are among the most common infections caused by microorganisms, and pyelonephritis is the most severe infection of the urogenital tract. The risk of developing chronic renal insufficiency due to a UTI without other risk factors is low. The pathogenicity and virulence of the infective microorganisms as well as the efficiency of local or systemic defence mechanisms determine the course and severity of the disease. Virulence properties (adhesins, toxins, capsule, iron uptake) are encoded by genomic structures and the determination of virulence is influenced by the host situation. In renal insufficiency, a variety of quite different substances (uraemic toxins, betaine, amino acids, creatinine, urea, glucose) influence the microbial environment. Defence factors (Tamm-Horsfall protein, defensin, phagocytic activity of granulocytes) and underlying anatomical lesions as well as pre-existing renal disease determine the severity of UTI and the prognosis of renal insufficiency.

Deleterious effects of mild hypothermia in septic rats are ameliorated by granulocyte colony-stimulating factor.

The authors studied the effects of mild hypothermia on the outcome in a rat model of intraabdominal sepsis and tested whether granulocyte colony-stimulating factor (G-CSF) augments the host response and improves outcome during mild hypothermia. A rat model of peritoneal contamination and infection with human stool bacteria was used to simulate clinical trials that included increasing complexity. In trial 1, postoperative hypothermia (32 degrees C) was compared with normothermia (38 degrees C), without supportive treatment (10 rats per group). In trial 2, with a more severe infection, rats were given antibiotic prophylaxis. Using 20 rats per group, the authors compared postoperative hypothermia (32 degrees C), normothermia, and postoperative hypothermia (32 degrees C) with 20 mug/kg G-CSF prophylaxis given 12 h before surgery and 12 h and 36 h after surgery. The primary endpoint was death at 120 h. Secondary endpoints were systemic cytokine concentrations, leukocyte counts, and the phagocytic activity of granulocytes and monocytes. In trial 1, 50% of the normothermia group and 10% of the postoperative hypothermia group survived. In trial 2, 50% of the normothermia group, 20% of the hypothermia group, and 60% of the hypothermia plus G-CSF group survived. Postoperative hypothermia plus G-CSF reduced plasma concentrations of interleukin-6 (hypothermia group, 511 +/- 104 pg/ml; hypothermia plus G-CSF group, 247 +/- 51 pg/ml) and macrophage inflammatory protein-2 (hypothermia group, 239 +/- 43 pg/ml; hypothermia plus G-CSF group, 178 +/- 21 pg/ml). In this rat model of intraabdominal sepsis, postoperative hypothermia was deleterious. However, G-CSF treatment, initiated before contamination, reduced the mortality rate, increased the neutrophil count, and downgraded the systemic cytokine response.

Granulocyte colony-stimulating factor but not peritoneal lavage increases survival rate after experimental abdominal contamination and infection.

The value of peritoneal lavage for intra-abdominal contamination and infection has never been proven scientifically. In contrast, the stimulation of host defence mechanisms with cytokines such as granulocyte colony-stimulating factor (G-CSF) has appeared promising in recent clinical trials. Clinic modelling randomized trials (CMRTs), which model the complexity of the clinical reality, were used in rats in which peritoneal contamination and infection (PCI) was produced with human stool bacteria. The following groups were compared: trial 1, intraoperative peritoneal lavage with saline versus taurolin (18 rats per group); trial 2, no lavage versus saline lavage versus saline lavage plus subcutaneous administration of G-CSF (18 rats per group); trial 3, lavage with saline versus no lavage (30 rats per group). The primary endpoint was mortality at 120 h. Secondary endpoints were the phagocytic activity of granulocytes, and systemic and peritoneal cytokine levels. In trial 1 lavage with taurolin was not superior to that with saline (five of 18 versus eight of 18 animals survived; P = 0.32). In trial 2, six of 18 animals having no lavage and three of 18 receiving saline lavage survived. The combination of lavage and G-CSF increased the number of animals surviving to 11 of 18 (P < 0.05). Lavage combined with G-CSF stimulated granulocyte phagocytic activity (P < 0.01) and reduced the levels of interleukin (IL) 6 (P < 0.01) and tumour necrosis factor alpha (P < 0.05) in peritoneal fluid, as well as plasma levels of IL-6 (P < 0.05) and IL-10 (P < 0.01). In trial 3, survival was not significantly different in animals having lavage (14 of 30) and no lavage (19 of 30) (P = 0.14). In these CMRTs of intra-abdominal contamination and infection, peritoneal lavage was not beneficial, but when lavage was combined with subcutaneous administration of G-CSF mortality was reduced and the local and systemic cytokine response was downgraded. Results from these CMRTs were used directly to define the trial conditions of a randomized clinical trial with G-CSF. Peritoneal lavage is not recommended.

Differences in the phagocytic activity of granulocytes and their immunocorrection in chronic aflatoxicosis B1 and benzene poisoning

After 60 days of intoxication, low doses of aflatoxin B1 decreased the total protein concentration, an indicator of phagocytosis completeness, and had no effect on the level of lysosomal cationic proteins. Benzene decreases both parameters, but does not affect the total protein content. The amino acid preparations cerebrolysin and aviamine and glutamic acid normalize the phagocytic activity of granulocytes decreased by benzene, but not by aflatoxin.

Effect of virginiamycin on digestibility of nutrients, blood and immunologic parameters, and quality of meat in veal calves

SummaryExperiments were carried out in 1992 with ten male calves, 4 weeks old initially, on a milk diet. Five calves received 80 mg/head virginiamycin (a feed antibiotic) daily for about 14 weeks. Virginiamycin significantly (P &lt; 0·05) increased weight gains (122±2 kg ν. 114±2 kg), digestibility of ash, serum iron and haemoglobin. The feed intake per 1 kg of gain was non-significantly lowered in the virginiamycin group. The phagocytic activity of granulocytes in blood samples of treated calves was slightly increased with a concomitant decrease in the concentration of immunoglobulins. Meat of virginiamycin-fed calves tended to be somewhat darker, to contain more K, Na and Fe and to have a higher pH 24 h post mortem. There were no major differences in other qualitative characteristics of meat between the groups.

Hematological and enzymatic results of aluminum intoxication in rats

1. The study has been carried out on Wistar rats. The aim of the present study was to trace the effect of aluminum on enzyme activities and hematological parameters on erythrocytes. 2. Aluminum decreased activities of acetylcholinesterase, glutathione reductase, glucose-6-phosphate dehydrogenase, and lactate dehydrogenase in the erythrocytes of the animals tested. 3. In the peripheral blood, a significant decrease in the erythrocyte count, hemoglobin level and hematocrit index and increased percentage of reticulocytes and polychromatophilic erythrocytes were observed. 4. The increase in the neutrophilic granulocyte and lymphocyte count was significant. 5. An inhibitory effect of aluminum on the phagocytic activity of granulocytes was also observed.

Haematological results of vanadium intoxication in wistar rats

1. Two-month-old rats of the Wistar strain of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) of 0.15 mg V/cm 3 concentration for a period of 4 weeks. 2. A small decrease in the amount of food consumed and a significant reduction of the water AMV solution drunk were observed, as compared with the food and water taken up by the control group. 3. In the peripheral blood a significant decrease in the erythrocyte count and haemoglobin level and increased percentage of reticulocytes and polychromatophilic erythrocytes were noted. 4. No changes in the activity of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6PD) were found in the erythrocytes of the animals tested. 5. The increase in the neutrophilic granulocyte and lymphocyte count was significant. 6. An inhibitory influence of vanadium on the phagocytic activity of granulocytes was observed.

Fc‐binding components: a virulence factor in Actinobacillus actinomycetemcomitans?

Actinobacillus actinomycetemcomitans (ATCC 33384) can produce and release components that bind to the Fc part of IgG. Fc-binding components were observed in whole bacteria, capsular material and medium from broth cultures. The components were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotted with biotinylated Fc-fragments and myeloma proteins. In a phagocytosis assay with human granulocytes and sheep erythrocytes, preincubation of opsonized erythrocytes with protein A reduced phagocytosis by 90%. In contrast, preincubation of the opsonizing antibody with medium components from a culture of A. actinomycetemcomitans enhanced the opsonizing effect of the antibody. The enhanced binding of erythrocytes may be caused by formation of aggregates between opsonizing antibody and bacterial Fc-binding components. Aggregated IgG can bind to low-affinity Fc gamma II and gamma III receptors that cannot bind monomeric IgG. Release of Fc-binding components from bacteria may contribute to the periodontal lesion through interference with the phagocytic activity of granulocytes and with the complement system. Fc-binding components may also interfere with downregulation of the B-cell response.

Assessment of phagocytic activity of granulocytes using laser flow cytometry

A laser flow cytometer assay for assessing two functions of polymorphonuclear leucocytes is described. The technique permits the quantitation of phagocytosis and intracellular killing of yeast cells by leucocytes and is illustrated with results obtained using porcine polymorphonuclear leucocytes.

Transfer factor and repeated otitis media

The effect of transfer factor (TF) was investigated in 12 children with repeated otitis media. These patients were immunologically compared to a control group of 23 age-matched healthy children. Levels of immunoglobulins, total and “active” T-cells, and phagocytic activity of granulocytes and monocytes were evaluated in the 12 children prior to, during, and after TF therapy. Percentages of “active” T cells and absolute numbers of “active” T and total T cells, which were initially low in the patient group, increased significantly after TF therapy to statistically match those of the healthy control group. The percentage of phagocytic monocytes in patients after therapy did not differ from healthy children; however, the percentage of phagocytic granulocytes remained depressed significantly. The levels of IgG, IgA, and IgM were unaffected by the therapy although the IgA and IgM were higher in the patient population throughout the study. After therapy, one-half of the patient population remained asymptomatic for a 1-year period and the others had markedly reduced attack rates.

Phagocytic activity of granulocytes and alveolar macrophages after burn injury measured by chemiluminescence

Despite substantial progress in handling the acute phase, about 50 per cent of all severely burned patients are still subject to lethal infections during the later stages of the burn disease. Such patients frequently succumb to infections by opportunistic bacteria and viruses of normally low virulence indicating that the antiinfectious host defences are severely compromised. The present study was conducted in order to evaluate the effects of severe thermal injury on the two major categories of phagocytic cells, the circulating phagocytes of the blood and the alveolar macrophages as one population of the fixed phagocytes of the reticulo-endothelial system. The cells were isolated from burned and unburned rats. For quantitative assessment of the phagocytic function the chemiluminescence associated with the phagocytosis of opsonized zymosan particles was measured, using luminol as a chemiluminigenic probe. It turned out that as a consequence of the thermal trauma the phagocytic activity as measured by chemiluminescence is reduced in granulocytes as well as in alveolar macrophages.

Inhibitory effects of bilirubin and photobilirubin on neonatal and adult T lymphocytes and granulocytes.

The lymphoproliferative response to phytohemagglutinin of lymphocytes and spontaneous motility, chemotaxis and phagocytic activity of granulocytes were studied in the newborn and adult blood in the presence of bilirubin and photobilirubin. All of these activities were inhibited to the same extent by these substances. In addition, a significant difference between newborn and adult values was found. In conclusion, the authors suggest that phototherapy does not decrease bilirubin cellular toxicity.

The effects of bilirubin and phototreated bilirubin on the phagocytic activity of granulocytes: 27

The effect of bilirubin and phototreated bilirubin (10 mg/dl) on granulocytes (PMN) was studied "in vitro" utilizing the activity of the hexose-monophosphate shunt as an indirect index of granulocyte metabolic activity and, therefore, of its phagocytic function. Blood was obtained from 10 healthy full-term newborns and from 10 healthy adults. Bilirubin and phototreated bilirubin seem to determine a significant decrease in the metabolic activity - during phagocytosis of latex microspheres - of newborns' as well as adults' PMN. These data, obtained by studying the entire blood,allow to conclude that bilirubin and phototreated bilirubin - directly or indirectly - inhibit the PMN function and indicate that "in vitro" light exposure does not decrease bilirubin toxicity on PMN metabolic activity. This work received financial support from C.N.R., under the U.S.A.-Italy cooperative program in science (contract No. 78.01876.65).

The detection and characterization of phagocytic cells in established human cell lines synthesizing immunoglobulins.

SummaryLong-term suspension cultures of lymphoid cell lines were studied for phagocytic activity and pyrogen production. These cell lines were shown to actively phagocytize both polystyrene particles and Staphylococcus epidermidis, a function generally not attributed to lymphoid cells. We have observed that release of leukocytic pyrogen, normally associated with phagocytic activity of granulocytes and monocytes, did not accompany phagocytosis by these lymphoid cell lines.