Role of circulating platelets and granulocytes in PAF-induced pulmonary dysfunction in awake sheep

The effects of a single intravascular bolus injection of platelet-activating factor (PAF) on pulmonary hemodynamics, lung mechanics, and lung fluid and solute exchange were studied in 13 chronically instrumented unanesthetized sheep. Since PAF has profound effects on both platelets and granulocytes, we investigated the effects of platelet and granulocyte depletion on the sheep's response to exogenous PAF. Sheep received PAF when granulocyte and platelets counts were normal and after platelet depletion with rabbit antisheep platelet antibodies (n = 5) or granulocyte depletion with hydroxyurea (n = 5). Sheep served as their own controls, and the order of experimentation was varied. Bolus injections of PAF had reproducible effects on pulmonary hemodynamics (pulmonary arterial pressure increased acutely to 85 +/- 3.7 cmH2O) and lung mechanics (dynamic compliance of the lungs decreased to 24.5 +/- 3.8% of base line and resistance to airflow across the lungs increased greater than 10-fold) and caused marked increases in lung lymph concentrations of thromboxane B2 and 6-ketoprostaglandin F1 alpha. The single bolus injection of PAF also caused marked prolonged elevations in lung lymph flow and increases in the lymph-to-plasma protein concentration ratio for 3 h after PAF. PAF had profound effects despite platelet and granulocyte depletion. Platelet depletion slightly attenuated the pulmonary hypertension observed after PAF injection. Platelet depletion also attenuated the increases in thromboxane B2 concentrations in lung lymph, and lung mechanics normalized more rapidly in platelet-depleted sheep. There were no statistically significant effects of granulocyte depletion to less than 200 granulocytes/mm3 on any of the measured variables.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of storage conditions on function of granulocytes

The effect of collection technique, anticoagulant, pH, glucose, and temperature on in vitro granulocyte function were studied after 24 hr of storage in the liquid state. Collection by CL did not adversely affect granulocyte function, however, cells collected by FL had accelerated loss of bactericidal activity and chemotactic response. Citrate anticoagulants provided better maintenance of bacteridical activity, NBT reduction, and chemotactic response than heparin, EDTA, and ion-exchange anticoagulants. Chemiluminescence was well maintained when the initial pH of the preservative solution (CPD plasma) was between 6.5 and 8.0 but maintenance of chemotaxis required pH of 7.0–7.5. Glucose concentrations of 80–1000 mg/dl provided adequate maintenance of chemiluminescence and chemotaxis. Bacterial killing was well maintained by storage at either 1–6 or 20–24 °C. Storage at 1–6 °C caused decreased chemotaxis, decreased ability of granulocytes to adhere and spread on a foreign surface, and a decreased intravascular recovery and shortened half-life after transfusion. Although short-term liquid storage may be practical, at present, granulocytes should be transfused as soon as possible after collection.     

Spontaneous activation of circulating granulocytes in patients with acute myocardial and cerebral diseases.

Recent animal studies have suggested that there exists an activated subpopulation of circulating granulocytes which plays an important part in microvascular sequestration and tissue injury during shock and ischemia. In this respect, spontaneous granulocyte activation in form of pseudopod formation, a manifestation of actin polymerization, is a high risk for microvascular entrapment. The present investigation was carried out to determine if there is a significant difference in pseudopod formation in vitro between granulocytes obtained from healthy volunteers without symptoms and patients with acute cardiovascular illnesses. Blood samples from 25 healthy volunteers, 12 patients with acute myocardial infarction (AMI) and 12 patients with acute cerebral infarction (ACI) to determine spontaneous pseudopod formation in granulocytes with a high resolution light microscope over a period of several hours. The results revealed that the mean percentage of cells with pseudopod formation in the control group was below 10% in the first 3 hours, and increased to about 50% at 12 hours. In AMI patients, the level of activation within the first hour was not significantly different from the controls, but it rose rapidly to 90% in 4 to 5 hours. Patients with cerebral infarction, however, showed no significant difference from the control group. When the granulocytes of healthy subjects were incubated in plasma of AMI, the cells were activated similar to AMI granulocytes in their own plasma. When AMI plasma was serially diluted with Ringer's solution, the activation curve fell successively. These results indicate that AMI patients' blood contains plasma factor(s) which can activate granulocytes at a more rapid rate than controls.     

Fish granulocytes: Morphology,distribution, and function

In the last 20 years interest in fish granulocyte identification, distribution, and function has burgeoned, as evidenced by the increasing number of reports in scientific literature. Neutrophils, eosinophils, and basophils are present in peripheral blood and certain organs of fish. Some species of fish have all three cell types, while other species may only possess one cell type. Granulopoiesis in fish occurs in the spleen, kidneys, epigonal organ, organ of Leydig, and other specialized tissue, with the specific locations depending on the species. In some fish, neutrophils are actively phagocytic. In vitro assays indicate phagocytosis, mobilization in response to chemotaxins, detectable chemiluminescence, and an active respiratory burst when appropriately stimulated. In fish species without neutrophils, the eosinophil may be responsible for phagocytosis. Eosinophils also function in antiparasite immunity in certain species. Basophil function has not been investigated. Responses of fish neutrophils and eosinophils can be altered by season of the year, environmental pollutants, disease, and others stressors. Differences among fish species in type, cellular distribution, and function of granulocytes are the focus of this review.     

Role of circulating granulocytes in sheep lung injury produced by phorbol myristate acetate

Phorbol myristate acetate (PMA) and endotoxin cause pulmonary granulocyte sequestration and alteration in lung fluid and solute exchange in awake sheep that are felt to be analogous to the adult respiratory distress syndrome in humans. The basic hypothesis that PMA causes lung injury by activating circulating granulocytes has never been tested. The effects of infused PMA on lung mechanics and the cellular constituents of lung lymph have also not been reported. We therefore characterized the effects of intravenous PMA, 5 micrograms/kg, on lung mechanics, pulmonary hemodynamics, lung fluid and solute exchange, pulmonary gas exchange, blood and lymph leukocyte counts, and plasma and lymph cyclooxygenase products of arachidonate metabolism in 10 awake sheep with normal granulocyte counts and after granulocyte depletion with hydroxyurea. PMA significantly altered lung mechanics from base line in both nongranulocyte depleted and granulocyte-depleted sheep. Dynamic compliance decreased by over 50% and resistance to airflow across the lungs increased over threefold acutely following PMA infusion in both sets of experiments. Changes in lung mechanics, pulmonary hemodynamics, lung fluid and solute exchange, pulmonary gas exchange, and plasma and lymph arachidonate metabolites were not significantly affected by greater than 99% depletion of circulating granulocytes. We conclude that the lung injury caused by PMA in chronically instrumented awake sheep probably is not a result of activation of circulating granulocytes.     

Alcohol, wine and platelet function

Epidemiological studies have demonstrated an inverse correlation between moderate wine and alcohol consumption and morbidity and mortality from coronary heart disease. The protective effect has been associated with an increase in the plasma level of HDL cholesterol, as it is well recognized that plasma HDL is inversely correlated with CHD. In addition, it has become evident that blood platelets contribute to the rate of development of atherosclerosis and CHD through several mechanisms. In recent studies it has been shown that the level of HDL cholesterol can explain only 50% of the protective effect of alcoholic beverages; the other 50% may be partly related to a decrease in platelet activity. This anti-platelet activity of wine is explained by ethanol but also by the polyphenolic components with which red wines are richly endowed. Several studies carried out on humans and animals have shown that wine phenolics could exert their effects by reducing prostanoid synthesis from arachidonate. In addition, it has been suggested that wine phenolics could reduce platelet activity mediated by nitric oxide. Moreover, wine phenolics increase vitamin E levels while decreasing the oxidation of platelets submitted to oxidative stress. However, a rebound phenomenon of hyperaggregability is observed after an acute alcohol consumption which is not observed with wine consumption. This protection afforded by wine has been duplicated in animals with grape phenolics added to alcohol. The rebound phenomenon may explain ischemic strokes or sudden deaths known to occur after episodes of drunkenness. It appears that wine, and wine phenolics in particular, could have a more significant inhibitory effect on platelet aggregation and could explain, in part, the hypothesis that red wine is more protective against atherosclerosis and coronary heart disease.     

1,25-Dihydroxyvitamin D3 and the regulation of the differentiation and function of macrophages and granulocytes

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) exerts a differential inhibitory effect on the formation of granulocyte, granulocyte/macrophage, and macrophage colonies grown from mouse bone marrow precursor cells; 50% inhibition was attained at 1.1, 2.3, and 23 nM 1,25(OH)2D3, respectively. The inhibition of colony formation, as well as phagocyte proliferation in liquid cultures, requires the presence of 1,25(OH)2D3 in the early stages of culture (up to 72 h after culture initiation). 1,25(OH)2D3 induces a dose- and time-dependent augmentation of the phagocytic capability of mononuclear phagocytes (up to 100%) towards both heat-killed yeast cells and IgG-coated sheep red blood cells. The augmentation of the phagocytic capability of the mononuclear phagocytes depends critically on when 1,25(OH)2D3 is added. It is effective when added up to 72 h after culture initiation, while at later stages (greater than or equal to 96 h) the cells are no longer induced to express enhanced phagocytic capability. We suggest that these phenomena may be relevant to hemopoietic processes.     

Alcohol consumption is directly associated with circulating oxidized low-density lipoprotein

Findings on the association of alcohol consumption and oxidation of low-density lipoprotein (LDL), which is thought to play a crucial role in the generation of atherosclerotic lesion, are inconsistent. The aim of the present study was to investigate the association of total alcohol consumption and type of alcoholic beverage with circulating plasma LDL oxidation. This cross-sectional study included data of circulating oxidized LDL (ox-LDL) from a subpopulation of 587 men and women enrolled in a population-based survey conducted in 2000 in Girona (Spain). Multivariate analysis was performed to describe the independent association of alcohol consumption and ox-LDL. Increasing alcohol consumption was associated with high in vivo ox-LDL levels in the present population. The consumption of 10 g of alcohol was associated with an increase of 2.40 U/L of ox-LDL (p = 0.002). Adjustment for dietary variables, leisure-time physical activity, educational level, smoking, LDL-cholesterol, high-density lipoprotein-cholesterol, glycemia, triglycerides, diabetes, body mass index, waist circumference, and systolic and diastolic blood pressures only slightly modified this association (p = 0.003). In this full adjusted model the consumption of 10 g of alcohol per day was associated with an increase of 2.11 U/L of ox-LDL. Consumption of wine (ml/day) was associated with increasing ox-LDL levels (p = 0.029), however, attenuated after controlling for alcohol. No significant relationship of ox-LDL with alcohol-independent consumption of wine, beer, and spirits was observed. Alcohol consumption was independently and directly associated with circulating ox-LDL in the present population.     

Fine structure of the camel neutrophilic granulocytes with special references to its function

This study is directed at the population of neutrophilic granulocytes in the peripheral circulating blood of the one-humped camel. The detailed fine structure is described and a number of cellular parameters are determined. Particular attention was given to the characteristics of the cytoplasmic granules of this cell type. The functional roles of these intracellular granules are discussed.     

Recovery,structure, and function of dog granulocytes after freeze-preservation with dimethylsulfoxide

The recovery, structure and function of dog granulocytes were determined before and after freeze-preservation. Leucocytes were isolated from defibrinated or anti-coagulated whole blood and subsequent erythrocyte sedimentation on a column of 2:1 dextran (6%)-isopaque (33.9%). Granulocytes isolated by these procedures were examined for changes in O₂ consumption associated with phagocytosis, in vitro directed migration (chemotaxis), bactericidal activity, and ultrastructure before and after freezing. Granulocytes were frozen in DMSO (7.5%) and autologous serum or HBSS-minus and 20% autologous serum at the rate of ?1 °C/min to ?80 °C and stored in liquid N₂ vapor.After freeze-preservation, O₂ consumption associated with phagocytosis was decreased by 54 and 64% for granulocytes isolated from defibrinated or from ACD-anticoagulated blood, respectively. Bactericidal activity is only slightly depressed in samples from either isolation method after freeze-preservation when compared to the prefreeze controls, but granulocytes isolated from defibrinated blood are significantly less effective in killing bacteria than those from ACD-anticoagulated blood. Chemotactic response after freeze-preservation was completely inhibited in granulocytes isolated from defibrinated blood. Exposure of granulocytes to ACD inhibited chemotaxis prior to freezing, but the granulocytes responded chemotactically after freeze-thaw and additional washing. The ultrastructure of granulocytes observed before and after freeze-thaw was similar for cells isolated by both methods. However, nuclear, cytoplasmic, and granular changes observed were slightly greater in granulocytes isolated from defibrinated blood. Dog granulocytes isolated by either method withstood freeze-preservation in DMSO to a degree not previously reported.It is concluded that dog granulocytes freeze-preserved by these methods are functional in vitro, but that phagocytic, directed migration, and bactericidal functions and ultrastructure are impaired to different degrees, according to the method of isolation and preparation for storage. These results indicate the need for continued investigation on the effects of storage variables on the preservation of granulocytes.     

The function of granulocytes stored in whole blood in relation to the storage time

Whereas numerous investigations and extensive experiences have been available for some years on problems of storing erythrocytes and thrombocytes, it was only recently that the storage of granulocytes with the aim at maintaining their function for a longer period has been given proper regard as a problem, which, however, could not be brought to a satisfactory solution. Primarily, attention is focused on specific cell physiology. At the same time it is necessary to have at hand a number of approaches covering as many partial aspects of the granulocyte function as possible to identify the functional damages or the extent of cell damage in connection with storage. In the present paper the behaviour of granulocytes under conditions commonly used in transfusion medicine for storing blood are investigated for a period of 4 days by controlling the total leukocyte and granulocyte values, pH value, osmolality, vitality test in the colour excluding test as well as by function tests such as behaviour of phagocytosis and NBT capability of reduction. A report is presented on the results of quantitative and qualitative changes in the investigated parameters.     

Evaluation as a function of granulocytes in hyperimmunoglobulinemia E syndrome with recurrent infections

The hyper-IgE syndrome with recurrent infections (HIESRI) is characterized by skin and respiratory infections due to Staphylococcus aureus and several fungi infections which are frequently associated with tissue damage. A deficiency in the chemotaxis of phagocytic cells has been documented to explain these findings; however, the expression of adhesion molecules, the secretion of cytokines that activate granulocytes and the production of oxygen reactive molecules have not been evaluated in HIESRI. Six HIESRI patients were evaluated for the following parameters: (1) secretion of GM-CSF and IL-5 by mitogen and antigen-activated mononuclear cells, (2) the chemotactic response of FMLP-activated granulocytes, (3) the respiratory burst of PMA-activated granulocytes, and (4) the expression of L-selectin and CD11b in PMA-activated granulocytes. Human recombinant GM-CSF and culture supernatants were evaluated for capacity to modulate granulocytic function. Compared to controls, HIESRI patients showed a normal production of GM-CSF and an increase in the basal secretion of IL-5. No significant differences were observed for chemotaxis, respiratory burst or L-selectin and CD11b expression. The GM-CSF did not modulate these functions in granulocytes from HIESRI patients, but culture supernatants applied to granulocytes inhibited chemotaxis, increased respiratory burst and caused the shedding of L-selectin from the granulocyte surface. The 6 HIESRI patients were nonsymptomatic during the time of this research due to a program of continued treatment; findings suggest that granulocytes are activated more easily in response to proinflammatory factors and that production of these factors is higher in HIESRI.