Susceptibility to Echinococcus multilocularis infection considerably varies among intermediate (mostly rodents) and dead-end host species (e.g. humans and pig), in particular regarding intestinal oncosphere invasion and subsequent hepatic metacestode development. Wistar rats are highly resistant to infection and subsequent diseases upon oral inoculation with E. multilocularis eggs, however, after immunosuppressive treatment with dexamethasone, rats become susceptible. To address the role of the cellular innate immunity, Wistar rats were individually or combined depleted of natural killer (NK) cells, macrophages (MΦ) and granulocytes (polymorphonuclear cells, PMN) prior to E. multilocularis egg inoculation. Although NK cell and MΦ depletion did not alter the resistance status of rats, the majority of PMN-depleted animals developed liver metacestodes within 10 weeks, indicating that PMN are key players in preventing oncosphere migration and/or development in Wistar rats. In vitro studies indicated that resistance is not caused by neutrophil reactive oxygen species or NETosis. Also, light microscopical examinations of the small intestine showed that oral inoculation of E. multilocularis eggs does not elicit a mucosal neutrophil response, suggesting that the interaction of oncospheres and neutrophils may occur after the former have entered the peripheral blood. We suggest to consider granulocytes as mediators of resistance in more resistant species, such as humans.

Background and objective: Volatile anaesthetic agents are known to influence neutrophil function. The aim was to determine the effect of chronic occupational exposure to volatile anaesthetic agents on the rate of neutrophil apoptosis among anaesthetists. To test this hypothesis, we compared the rate of neutrophil apoptosis in anaesthetists who had been chronically exposed to volatile anaesthetic agents with that in unexposed volunteers.

Methods: Venous blood (20 mL) was withdrawn from 24 ASA I-II volunteers, from which neutrophils were isolated, and maintained in culture. At 1, 12 and 24 h in culture, the percentage of neutrophil apoptosis was assessed by dual staining with annexin V-FITC and propidium iodide.

Results: At 1 h (but not at 12 and 24 h) in culture, the rate of neutrophil apoptosis was significantly less in the anaesthetists – 13.8 (12.9%) versus 34.4 (12.1%) (P = 0.001).

Conclusions: Chronic occupational exposure to volatile anaesthetic agents may inhibit neutrophil apoptosis. This may have implications for anaesthetists and similarly exposed healthcare workers in terms of the adequacy of their inflammatory response.

Background and objective Respiratory burst is an essential component of the neutrophil's biocidal function. In vitro, sodium thiopental, isoflurane and lidocaine each inhibit neutrophil respiratory burst. The objectives of this study were (a) to determine the effect of a standard clinical induction/tracheal intubation sequence on neutrophil respiratory burst and (b) to determine the effect of intravenous lidocaine administration during induction of anaesthesia on neutrophil respiratory burst.

Methods Twenty ASA I and II patients, aged 18–60 years, undergoing elective surgery were studied. After induction of anaesthesia [fentanyl (2 μg kg−1), thiopental (4–6 mg kg−1), isoflurane (end-tidal concentration 0.5–1.5%) in nitrous oxide (66%) and oxygen], patients randomly received either lidocaine 1.5 mg kg−1 (group L) or 0.9% saline (group S) prior to tracheal intubation. Neutrophil respiratory burst was measured immediately prior to induction of anaesthesia, immediately before and 1 and 5 min after lidocaine/saline.

Results Neutrophil respiratory burst decreased significantly after induction of anaesthesia in both groups [87.4 ± 8.2% (group L) and 88.5 ± 13.4% (group S) of preinduction level (P < 0.01 both groups)]. After intravenous lidocaine (but not saline) administration, neutrophil respiratory burst returned towards preinduction levels, both before (97.1 ± 23.6%) and after (94.4 ± 16.6%) tracheal intubation.

Conclusion Induction of anaesthesia and tracheal intubation using thiopentone and isoflurane, inhibit neutrophil respiratory burst. This effect may be diminished by the administration of lidocaine.

Background and objective The objective of this study was to determine the dose as well as the duration of exposure–dependent effects of methohexital on neutrophil [polymorphonuclear leucocyte (PMN)] free amino acid profiles and, in a parallel study, on PMN immune functions.

Methods Whole blood samples were taken from 20 volunteers and incubated with methohexital [0 (control), 3.6, 26, 130 and 260 μgmL−1] for 10, 30, 60 or 120 min. PMN amino acid profiles were documented using advanced PMN separation and highperformance liquid chromatography procedures. Superoxide anion (O2−) and hydrogen peroxide production (H2O2), and activity of released myeloperoxidase (MPO), were determined photometrically.

Results After methohexital, significant dose (≥26 μg mL−1) as well as duration of exposure–dependent (≥30 min) increases in histidine, isoleucine, leucine, valine, methionine, serine, glycine, threonine, and decreases in glutamine, glutamate, aspartate, asparagine, arginine, ornithine, citrulline, alanine and taurine were observed (P ≤0.05). Concerning PMN immune functions, methohexital significantly decreased O2−, H2O2 formation and MPO (≥26 μgmL−1, ≥30 min, P≤0.05).

Conclusions Altogether, there is significant relevance to the pharmacological regimens which enhance the supply of methohexital in whole blood. In regards to our results, we suggest that considerable changes in PMN ‘dynamic free amino acid pool’, for example induced by methohexital, may be one of the determinants in cell nutrition adversely affecting PMN metabolism. It is partially through its effect on the PMN free amino acid pool that maleficent pharmacological stress may have an unintentional influence on PMN immune functions.

Cardiac and major abdominal surgery are associated with granulocytosis in peripheral blood. The purpose of the present study was to describe the granulocyte and monocyte oxidative burst and the expression of adhesion molecules following cardiac surgery with cardiopulmonary bypass and abdominal surgery. The ability to respond with an oxidative burst was measured by means of flow cytometry using 123-dihydrorhodamine. The adhesion molecules CD11a/CD18, CD11c/CD18, CD44 were measured using monoclonal antibodies. Blood samples from eight patients undergoing open-heart surgery were taken before surgery, 1, 5, 10 and 20 min after aortic clamping, and then 1, 5, 10 and 20 min and 1, 2 and 3 h after declamping. Samples from eight patients undergoing abdominal surgery were taken before surgery, at the end of surgery, and 2 and 3 h post-operatively. A decrease in number of granulocytes and monocytes during cardiopulmonary bypass was observed. The percentage of CD11a-positive granulocytes increased from 30% preoperatively to 75% following cardiopulmonary bypass, while CD44-positive granulocytes increased from 5% to 13%. Despite the extent of the changes, these were not significant. The oxidative burst of the granulocytes and monocytes decreased after declamping to 15% and 27% of initial values in vitro. Several hours after surgery, there was no significant difference between the two groups. These results can be explained by a granulocyte and monocyte refractory response developing subsequent to an increased per-operative oxidative burst activity, and the induction of adhesion molecules on granulocytes associated with the cardiopulmonary bypass and surgery. In conclusion, open-heart surgery with cardiopulmonary bypass was associated with a rapid and pronounced activation of leukocytes which may play a role in reperfusion injury.

The venerid clams, Tapes decussatus and T. semidecussatus, develop a singular defensive response to Perkinsus atlanticus infection. This reaction involves the redifferentiation of recruited granulocytes and the expression de novo of the polypeptide p225. To determine whether the association of this defensive process with the natural parasitism by P. atlanticus is unique, the inflammatory response elicited by inoculations of bacteria, algae and non-viable P. atlanticus pre-zoosporangia in the clam T. semidecussatus was shown. Inoculated areas were heavily infiltrated by granulocytes and delimited by myofibroblast-like cells and extracellular matrix. While bacteria and algae were phagocytosed by the infiltrated granulocytes, pre-zoosporangia were not. After 40 days, neither cell redifferentiation nor the expression of p225 was observed. These findings indicate that both redifferentiation and p225 expression are specifically associated with P. atlanticus infection. After 5-bromodeoxyuridine administration, only a few cells were labelled either in the inoculated zone or in the cellular reaction around P. atlanticus meronts. Significant differences between untreated and inoculated groups were observed in the epicardic connective tissue soon after injection. These results suggest that this anatomical region could be the main site of haemocyte proliferation stimulated after inoculation of foreign bodies in T. semidecussatus.

Three morphological classes of haemocytes (prohaemocytes, plasmatocytes and granulocytes) were observed in the haemolymph of Glossina morsitans morsitans and G. pallidipes. In addition to the three types, a category of spindle cells were also observed in haemolymph especially in the newly emerged Glossina. Based on their unusual morphology, as well as on their inverse relationship with the number of thrombocytoids (a filamentous plasmatocyte), it is suggested that these spindle cells might be precursors of thrombocytoids observed mostly in older Glossina. The number of thrombocytoids increased progressively with the increasing age of the flies. Total haemocyte counts (THCs) dropped significantly during the first 48 hr following emergence, after which the values levelled off with the exception of minor fluctuations. This sudden drop in THCs resulted primarily from a remarkable decrease in the number of the spindle cells in the haemolymph. The number of round plasmatocytes decreased gradually and progressively with age of the flies, while the number of the granulocytes increased, suggesting a possible transformation of plasmatocytes into granulocytes. Newly emerged female G. morsitans morsitans were observed to have significantly higher THCs (P < 0.01) than males of the same age. Although no difference was observed between THCs of 5-week-old pregnant and non-pregnant female G. morsitans morsitans, the differential haemocyte counts (DHCs) showed that the concentration of thrombocytoid fragments was significantly lower (P < 0.01) in the pregnant than in the non-pregnant females.