Phytoestrogens ß -sitosterol and genistein have limited effects on reproductive endpoints in a female fish, Betta splendens.

Phytoestrogens are produced by plants and may cause endocrine disruption in vertebrates. The present study hypothesizes that phytoestrogen exposure of female Siamese fighting fish (Betta splendens) may disrupt endogenous steroid levels, change agonistic behavior expression, and potentially also disrupt oocyte development. However, only the pharmacologic dose of ß-sitosterol had a significant effect on opercular flaring behavior, while we did not find significant effects of ß-sitosterol or genistein on steroids or gonads. These findings are in direct contrast with previous studies on the effects of phytoestrogens in female fish. Results of the current study support previous work showing that the effects of phytoestrogen exposure may be less acute in mature female B. splendens than in other fish.

A pilot study of pulmonary rehabilitation and chest physiotherapy versus chest physiotherapy alone in bronchiectasis.

AIM: The aim of our study was to assess the efficacy of pulmonary rehabilitation in addition to regular chest physiotherapy in non cystic fibrosis bronchiectasis. METHODS: Thirty patients with clinically significant bronchiectasis and limited exercise tolerance were randomized into either the control group receiving chest physiotherapy (8 weeks) or into the intervention group, receiving pulmonary rehabilitation in addition to chest physiotherapy (8 weeks). Both groups were encouraged to maintain their exercise program and or chest physiotherapy, following completion of the study. RESULTS: End of training (8 weeks) No improvement in control group. In the intervention group, incremental shuttle walk test (ISWT) improved by 56.7 m (p = 0.03), endurance walk test (EWT) by 193.3 m (p = 0.01), Leicester Cough Questionnaire (LCQ) improved by 2.6 units (p < 0.001) and St. George's Respiratory Questionnaire (SGRQ) by 8 units (p < 0.001). At 20 weeks (12 weeks post end of training) No improvement in control group. In the intervention group, ISWT improved by 80 m (p = 0.04) and EWT by 247.5 m (p = 0.003). LCQ improved by 4.4 units (p < 0.001) and SGRQ by 4 units (p < 0.001). CONCLUSION: Pulmonary rehabilitation in addition to regular chest physiotherapy, improves exercise tolerance and health related quality of life in non cystic fibrosis bronchiectasis and the benefit was sustained at 12 weeks post end of pulmonary rehabilitation. Clinical trials regn no. NCT00868075.

Exercise-induced elevation in plasma oxidative generating capability augments the temporal inflammatory response stimulated by lipopolysaccharide.

Prolonged oxidative stress is detrimental to health; however, transient oxidative stress may improve immune capability. We examined whether exercise-induced increases in the plasma oxidative generating capability enhance immune responsiveness to potential pathogens. Twelve individuals underwent a 30-min row and pre and post-exercise bloods were collected for oxidative stress and immune assessment. We found that exercise induced a transient increase in plasma carbonyls (3.2-5.3 nmol/mg protein) and creatine kinase activity (0.5-1.2 absorbance/min/mg protein) and that lipopolysaccharide (LPS) stimulation (0.5-24 h) of pre- and post-exercise blood augmented temporal tumour necrosis factor-alpha (TNFalpha) secretion. Further characterisation of plasma using a modified dihydro-2',7'-dichlorohydrofluorescein (DCF) assay revealed that addition of a sub-threshold of hydrogen peroxide to post-exercise (and not pre-exercise) plasma caused a sixfold increase in the radical oxygen species (ROS) generating capability after 15 min (555 +/- 131 to 3607 +/- 488 change in fluorescent intensity [DeltaFI]), which was inhibited using 60 mM N-acetyl-L: -cysteine (920 +/- 154 DeltaFI). Furthermore, cell experiments revealed that LPS stimulation of either THP-1 cells pre-incubated with post-exercise plasma or peripheral blood mononuclear cells pre-treated with pro-oxidants, modulated the temporal secretion of key cytokines that regulate the initiation, progression and resolution of an inflammatory response. These results indicate that exercise-induced changes in plasma parameters (e.g. oxidative generating capability-dependent or independent of inflammatory mediators) augment the temporal LPS response and support the notion that repeated transient oxidative stress (such as that induced by regular exercise) is important for a "healthy" immune system.

Short-term blackcurrant extract consumption modulates exercise-induced oxidative stress and lipopolysaccharide-stimulated inflammatory responses.

Exercise-induced oxidative stress is instrumental in achieving the health benefits from regular exercise. Therefore, inappropriate use of fruit-derived products (commonly applied as prophalytic antioxidants) may counteract the positive effects of exercise. Using human exercise and cellular models we found that 1) blackcurrant supplementation suppressed exercise-induced oxidative stress, e.g., plasma carbonyls (0.9 +/- 0.1 vs. 0.6 +/- 0.1 nmol/mg protein, placebo vs. blackcurrant), and 2) preincubation of THP-1 cells with an anthocyanin-rich blackcurrant extract inhibited LPS-stimulated cytokine secretion [TNF-alpha (16,453 +/- 322 vs. 10,941 +/- 82 pg/ml, control vs. extract, P < 0.05) and IL-6 (476 +/- 14 vs. 326 +/- 32 pg/ml, control vs. extract, P < 0.05)] and NF-kappaB activation. In addition to its antioxidant and anti-inflammatory properties, we found that postexercise plasma collected after blackcurrant supplementation enhanced the differential temporal LPS-stimulated inflammatory response in THP-1 cells, resulting in an early suppression of TNF-alpha (1,741 +/- 32 vs. 1,312 +/- 42 pg/ml, placebo vs. blackcurrant, P < 0.05) and IL-6 (44 +/- 5 vs. 36 +/- 3 pg/ml, placebo vs. blackcurrant, P < 0.05) secretion after 24 h. Furthermore, by using an oxidative stress cell model, we found that preincubation of THP-1 cells with hydrogen peroxide (H(2)O(2)) prior to extract exposure caused a greater suppression of LPS-stimulated cytokine secretion after 24 h, which was not evident when cells were simultaneously incubated with H(2)O(2) and the extract. In summary, our findings support the concept that consumption of blackcurrant anthocyanins alleviate oxidative stress, and may, if given at the appropriate amount and time, complement the ability of exercise to enhance immune responsiveness to potential pathogens.

Alkylamides from echinacea modulate induced immune responses in macrophages.

The ability of Echinacea and its components to alter the immune response was examined in vitro in a macrophage cell line under either basal or immunostimulated conditions. Potential immunostimulatory and inflammatory activity was determined using a nuclear transcription factor (NFkappaB) expression, tumour necrosis factor alpha (TNFalpha) and nitric oxide (NO) production as biomarkers. In the absence of alternate stimulation, the only significant effects seen were a decrease in NFkappaB expression by a 2-ene alkylamide ((2E)-N-isobutylundeca-2-ene-8,10-diynamide (1)) and a decrease in TNFalpha levels by cichoric acid and an Echinacea alkylamide fraction (EPL AA). When the cells were stimulated by lipopolysaccharide (LPS), inhibition of the increased NFkappaB expression levels was caused by cichoric acid, an Echinacea preparation (EPL), EPL AA and a 2,4-diene ((2E,4E,8Z,10Z)-N-isobutyldodeca-2,4,8,10-tetraenamide (2)). Increases in TNFalpha levels were inhibited by cichoric acid, EPL and EPL AA but enhanced by 1 in the presence of LPS, while only EPL AA was able to inhibit the stimulated increases in NO. When using phorbol myristate acetate to stimulate the cells, NFkappaB and NO levels were unaffected by Echinacea or its components while only cichoric acid and 2 inhibited TNFalpha levels. Although cichoric acid was found to have an effect, it is probably not an important contributor to the Echinacea modulation of the immune response in vivo, as it is not bioavailable. Echinacea appears to attenuate the response of macrophages to an immune stimulus and its combination of phytochemicals exhibits different pharmacological properties to one or more of the isolated major individual components.

Anti-allergy properties of fermented foods: an important immunoregulatory mechanism of lactic acid bacteria?

Clinical reports have suggested that dietary consumption of fermented foods, such as yogurt, can alleviate some of the symptoms of atopy and might also reduce the development of allergies, possibly via a mechanism of immune regulation. Controlled studies have indicated that consumption of fermented milk cultures containing lactic acid bacteria (LAB) can enhance production of Type I and Type II interferons at the systemic level. In animal models, LAB have been shown to promote interferon expression, and to reduce allergen-stimulated production of IL-4 and IL-5 in some cases. Recent results have shown that LAB are potent inducers of pro-interferon monokines (IL-12 and IL-18), and that cytokine secretion is stimulated by the interaction of Gram-positive cell wall components with surface receptors of mononuclear phagocytes, via NF-kappa B and STAT signalling pathways. However, it is clear that the extent and quality of LAB-induced immunoregulation is strain-dependent. This review discusses the clinical and laboratory evidence for anti-allergy properties of fermented foods, and proposes a model for the mechanism by which some well-defined strains of immunoregulatory LAB might down-regulate a Th2 allergic phenotype.

Expression of cell surface adhesion molecules by peripheral blood eosinophils during Trichostrongylus colubriformis infection in sheep.

The effect of infection of sheep with the gastrointestinal nematode parasite Trichostrongylus colubriformis on expression of adhesion molecules CD11a, CD11b, CD11c, CD18, CD44, CD49d and CD62L by peripheral blood eosinophils was examined by flow cytometry. Initially, to establish the sensitivity of adhesion molecules to inflammatory signals, eosinophil-rich exudates were elicited in non-lactating mammary glands of immune sheep by infusion of 50 microg of soluble antigen extract from T. colubriformis third stage larvae. Eosinophils comprised 40.8% of mammary leucocytes and 4.5% of peripheral blood leucocytes. In comparison with blood, the percentage of eosinophils expressing CD18 increased and the percentage expressing CD62L decreased in exudates and the mean fluorescent intensity, an indicator of receptor number per cell, for CD11a and CD49d also decreased on exudate eosinophils. Peripheral blood eosinophils were examined over 8 weeks during trickle infection of immune sheep with infective or irradiated third stage larvae of T. colubriformis. During the last 3 weeks of infection, CD11a staining decreased in infected sheep and CD44 staining decreased in sheep receiving either infective or irradiated larvae. Other surface markers did not change. The results indicate that systemic changes in expression of adhesion molecules by eosinophils occur during T. colubriformis infection in sheep.

Comparative aspects of plasma antioxidant status in sheep and goats, and the influence of experimental abomasal nematode infection.

This paper provides, for the first time, comparative data on the plasma antioxidant status of two ruminant species, namely sheep and goats. In addition, the influence of experimental infection with Teladorsagia circumcincta on antioxidant status in the same two species is compared and contrasted. In general terms, antioxidant status was significantly higher in uninfected kids than in lambs. Differences in protein sulphydryl groups and vitamin E concentrations were particularly noteworthy; trends were similar, however, for albumin, vitamin A and total antioxidant capacity (TAC). Parasitological results, based on worm burden, faecal egg counts and peripheral blood eosinophil numbers, confirmed that goat kids were more susceptible than lambs to experimental T. circumcincta infection. "Trickle infection" had a variable impact on both total and individual antioxidant status; particularly during the early weeks, the trend was for reduced values in lambs and increased values in kids, as compared with uninfected controls. Subsequent challenge infection was associated with a transient decrease in TAC and albumin in trickle-infected animals of both species, and in appropriate control animals. The observed differences in plasma antioxidant capacity between sheep and goats may have important implications in terms of the comparative resilience of sheep and goats to parasite infection.

Kinetic basis for activation of CDK2/cyclin A by phosphorylation.

The activation of most protein kinases requires phosphorylation at a conserved site within a structurally defined segment termed the activation loop. A classic example is the regulation of the cell cycle control enzyme, CDK2/cyclin A, in which catalytic activation depends on phosphorylation at Thr(160) in CDK2. The structural consequences of phosphorylation have been revealed by x-ray crystallographic studies on CDK2/cyclin A and include changes in conformation, mainly of the activation loop. Here, we describe the kinetic basis for activation by phosphorylation in CDK2/cyclin A. Phosphorylation results in a 100,000-fold increase in catalytic efficiency and an approximate 1,000-fold increase in the overall turnover rate. The effects of phosphorylation on the individual steps in the catalytic reaction pathway were determined using solvent viscosometric techniques. It was found that the increase in catalytic power arises mainly from a 3,000-fold increase in the rate of the phosphoryl group transfer step with a more moderate increase in substrate binding affinity. In contrast, the rate of phosphoryl group transfer in the ATPase pathway was unaffected by phosphorylation, demonstrating that phosphorylation at Thr(160) does not serve to stabilize ATP in the ATPase reaction. Thus, we hypothesize that the role of phosphorylation in the kinase reaction may be to specifically stabilize the peptide phosphoacceptor group.

Eosinophil-specific biological activity of recombinant ovine interleukin-5.

Recombinant ovine interleukin-5 (rovIL-5) expressed from Chinese hamster ovary (CHO) cells was tested for cell-specific bioreactivity, in vitro, in a soft agar clonogenic assay and in an enzyme-based microassay for eosinophil potentiating activity (EPA). In soft agar assays, colony and cluster formation from sheep bone marrow cells (SBMC) incubated with rovIL-5 was significantly enhanced compared with SBMC incubated with control supernatants from mock-transfected CHO cells. Colony analysis at 14 days demonstrated that for three separate rovIL-5 preparations 45%, 61% and 66% of colonies were eosinophilic, as were 55%-71% of clusters. In contrast, no eosinophil colonies were detected in parallel control cultures. RovIL-5 was also shown to possess potent and dose-responsive EPA, on the basis of eosinophil peroxidase (EPO) and arylsulphatase (EAS) assay in 7 day SBMC cultures. This activity was inhibited in a dose-responsive manner by TRFK-5, a rat anti-murine IL-5 monoclonal antibody (MAb) previously shown to have cross-reactivity in the ovine EPA assay. The results demonstrate that rovIL-5 exhibited eosinophil-specific properties similar to those of IL-5 derived from other mammalian species.

Persistence of immunity of Nematodirus battus infection in lambs.

Fifty-four Greyface Suffolk lambs aged 3 months were allocated to six groups of seven and one group of 12. Three groups were infected continuously with Nematodirus battus larvae (L3) over a 7-week period and three groups remained worm-free. One week after the last larval dose all six groups were treated with anthelmintic and challenged with a single dose of 30,000 N. battus L3 either 1, 6 or 12 weeks post-treatment (PT) and killed 10 days later. A seventh continuously infected and treated group (n = 12) was segregated into four sub-groups of three lambs which were used as tissue cell count controls and provided data on local cellular responses prior to challenge. Lambs in the first sub-group were killed immediately after anthelmintic treatment and those in the other sub-groups were killed on the same day that the lambs in the other main groups were challenged. Overall post-challenge worm burdens did not differ significantly between previously infected and challenge control groups although they were significantly reduced in both treatment groups by Week 12 PT. The principal manifestation of acquired immunity that was maintained throughout 12 weeks without further infection was retardation in larval development. There was also evidence of preferential rejection of male worms from immune lambs. Local mast cell, but not eosinophil, responses were significantly enhanced by previous infection and persisted up to Week 12 PT. The numbers of bone marrow eosinophils were significantly increased as a result of previous infection and this response persisted up to Week 12 PT. During primary infection anti-L4 and anti-adult worm IgG responses were significantly increased in the previously infected lambs by Day 42 post-infection. Eosinophil responses during this period did not differ between groups. The inflammatory cell responses, coupled with the parasitological observations, suggest that immunity to previous infection is maintained for up to 12 weeks PT without further antigenic stimulation. This 'immunological memory' may have waned partially after 6 weeks PT although the superimposition of age resistance may have masked the effect.

The response of breeding doses to nematodiasis: segregation into "responders" and "non-responders".

Responder and non-responder does were identified from a flock of 95 Scottish cashmere 2-6 year-old does exposed to natural nematode infection over a 12-month period. Every 5 weeks, the does were faecal sampled for worm-egg counts prior to anthelmintic treatment. Responsive and non-responsive individuals were identified on the basis of their cumulative faecal egg count (FEC) rankings: the 8 lowest and 8 highest rankings were deemed to be responders and non-responders, respectively. Retrospective analysis showed that the mean egg count of the 8 responders was significantly lower than that of the 8 non-responders. The selected responders and non-responders were subsequently housed together with 8 randomly selected does from a control line, and given a mixed trickle challenge with Teladorsagia circumcincta and Trichostrongylus vitrinus larvae (L3). Mean responders FEC was significantly lower following artificial infection than that of non-responder and unselected does. Peripheral eosinophilia was significantly greater in responders in the first 3 weeks of this infection. On day 60, the infection was terminated with anthelmintic and 7 days later the goats were given a single challenge of 50,000 T. circumcincta L3. The mean responder worm burden was lower, and exhibited greater evidence of retardation of worm development, than those of non-responder and unselected does. Responders had significantly more mast cells and globule leukocytes post-challenge than did the other 2 groups. These results suggest that under the conditions encountered in this experiment, it is possible to segregate goats into responders and non-responders using simple parasitological criteria, as individual responsiveness is a relatively repeatable phenomenon.

Dietary protein influences upon immunity to Nematodirus battus infection in lambs.

Several indices of the immune response to Nematodirus battus infection in lambs offered differing levels of dietary protein were quantified. Lambs were offered either a complete basal ruminant diet (13.2% crude protein (CP)) or the same diet supplemented with fish meal as a source of rumen bypass protein (18.3% CP). Lambs from each dietary treatment group were given either a 7-week continuous trickle infection with N. battus L3 or remained uninfected. All lambs were drenched with anthelmintic at week 8 post-infection (PI), challenged with a single dose of 30,000 N. battus L3 1 week later, and killed 9 days post-challenge (PC). Previous infection induced a significant reduction in worm burdens (p < 0.001) and enhancement of immune responses when compared to challenge controls. Among previously infected lambs, protein supplementation did not reduce worm burdens significantly, although there was a trend for fewer worms in the supplemented lambs. However, a significant increase in mucosal globule leucocyte (p < 0.05) and eosinophil (p < 0.05) numbers was evident. Supplementation (p < 0.05) and previous infection (p < 0.001) both enhanced serum anti-worm IgG titres over time. Peripheral blood eosinophil counts were not affected by supplementation but were significantly elevated over time as a result of previous infection (p < 0.001). Since there were no significant differences in worm burdens of supplemented and unsupplemented previously infected lambs, it was of interest to determine whether lambs possessed an innate ability to regulate their parasite burden. Hence they were re-grouped based on an arbitrary cut-off burden of 1000 worms. High responders (HR) had burdens below 1000 worms, while low responders (LR) had burdens above this value and challenge controls were pooled. The data were re-analyzed based on these groupings and showed significant reduction in worm burdens between all three groups (p < 0.001). Globule leucocytes were the only cell type that appeared to be significantly more abundant in the intestinal mucosa of HR (p < 0.001). Serum antibody responses (p < 0.05) and peripheral blood eosinophil counts (p < 0.01) were significantly elevated over time in accord with the degree of responsiveness. The results of this study suggest that supplementation of protein upon an adequate basal diet of lambs previously exposed to N. battus does not significantly enhance worm regulation despite significant increases in cellular and antibody responses. The immunity acquired is characterized by reduction in worm burdens, elevated anti-worm antibodies and a cellular inflammatory response. The identification of HR and LR essentially shows that when the protein supply is adequate, the predominant host effect influencing the pathogenicity of the parasites is the level of genetically determined susceptibility of the host.

Studies on caprine responsiveness to nematodiasis: segregation of male goats into responders and non-responders.

Eighty-three 2-4-year-old intact male goats exposed to a combination of artificial and natural challenge were segregated into responders and non-responders by ranking of weekly faecal egg counts (FECs). Retrospective analysis of samples over a 15-week-period showed responders had a statistically lower mean FEC than non-responders. Estimates of repeatability between consecutive egg counts were significant in both groups. The 6 top responders and bottom non-responders were subsequently given an artificial trickle challenge with Teladorsagia circumcincta and Trichostrongylus vitrinus. Mean faecal egg output was significantly lower in responders than non-responders. Peripheral eosinophil numbers following challenge were significantly greater in responder than non-responder goats. Abomasal and intestinal worm burdens were considerably lower in responders, with evidence of retardation of worm development compared to non-responders. Both abomasal and jejunal tissue eosinophil numbers were significantly higher in responders, although there was no difference in mucosal mast cell or globule leucocyte numbers. These results suggest that under temperate climatic conditions, it is possible to segregate male goats into responders and non-responders on the basis of simple parasitological criteria.

Haemopoietic cell responses in the blood and bone marrow of sheep infected with the abomasal nematode Telodorsagia circumcincta.

The generation of bone marrow and blood haemopoietic progenitor colony-forming cells (CFCs) in sheep given primary or challenge infections with the nematode parasite Telodorsagia circumcincta is described. Ten days after a primary infection, the frequency of early multipotential-CFCs, eosinophil-CFCs, macrophage-CFCs and mast cell or basophil-CFCs was greater than in controls. These frequencies then declined to pre-infection levels by day 21. Blood CFCs (mainly macrophage-CFCs and eosinophil-CFCs) also increased after infection, indicating a migration of CFCs, presumably to the site of infection. Ten days after challenge infection there was less marked myelopoiesis than in the primary infection on day 10, though both eosinophil-CFCs and mast cell or basophil-CFCs were significantly above control values. Blood CFC output (mainly macrophage-CFCs and eosinophil-CFCs) reached a peak 2-6 days after challenge, evidence of rapid recruitment to the site of infection. Telodorsagia circumcincta infection is therefore associated with an increase in myelopoiesis, particularly for the cell types characteristic of the local inflammatory response to abomasal nematodes. There was no correlation between any of the haemopoietic cell responses measured and worm burdens in individual animals after either primary or challenge infection.

A comparison of the mast cell and eosinophil responses of sheep and goats to gastrointestinal nematode infections.

The mucosal mast cell and eosinophil responses of goats and sheep to a mixed gastrointestinal nematode infection were compared. Groups of eight does and nine ewes, previously maintained on pasture and treated with anthelmintic when they were housed and five worm-free lambs were challenged with 10,000 Trichostrongylus vitrinus third stage larvae (L3) and 10,000 Teladorsagia circumcincta L3. Eleven days after challenge, the ewes had significantly (P < 0.001) lower burdens of abomasal and intestinal worms than the does or naive lambs, but significantly higher (P < 0.001) tissue concentrations of mast cell proteinase. Toluidine blue-stained sections indicated a paucity of mast cells in the does compared with the ewes, whereas the immunolocalisation of sheep mast cell proteinase revealed similar numbers of stained cells in the two species. This discrepancy was due to the relatively high proportion of globule leucocytes (77 and 91 per cent in the jejunum and abomasum, respectively) in the does compared with the ewes (7 and 24 per cent in the jejunum and abomasum, respectively). No differences were detected between the numbers of circulating or tissue eosinophils in the ewes and does.

Cross-reactivity amongst recombinant haematopoietic cytokines from different species for sheep bone-marrow eosinophils.

The potentiating effects of a variety of recombinant cytokines on the survival or proliferation (or both) of sheep bone marrow eosinophils in vitro were assessed by means of cell-specific enzyme microassays for eosinophil peroxidase (EPO) and eosinophil arylsulphatase (EAS). In this system recombinant human and mouse interleukin 5 (rhIL5 and rmIL5, respectively) had potent eosinophil potentiating activity (EPA) that was reciprocally inhibited by polyclonal anti-rhIL5 and anti-rmIL5 antibodies and by a specific monoclonal anti-rmIL5 (TRFK5). Recombinant ovine granulocyte-macrophage colony-stimulating factor (rovGM-CSF) and interleukin 3 (rovIL3) also had marked EPA for sheep cells, and the activity of the former was blocked by a mouse monoclonal anti-rovGM-CSF. The equivalent human and murine recombinant GM-CSFs and IL3s had no detectable effect on sheep eosinophils, nor did antibodies against them influence the EPA of any of the ovine cytokines. The evidence presented provides further support to the concept that the structure, biological reactivity and cell specificity of IL5 is highly conserved in mammals, whereas other eosinopoietins such as IL3 and GM-CSF are more species-specific.

Local eosinophil- and mast cell-related responses in abomasal nematode infections of lambs.

Eosinophil numbers in peripheral blood and eosinophil potentiating activity (EPA) and sheep mast cell protease (SMCP) in efferent gastric lymph were monitored in lambs during infections with Ostertagia circumcincta. Worm burdens, eosinophil numbers in bone marrow, abomasal mucosa and gastric lymph node, as well as mast cell numbers and SMCP concentrations in mucosa and mucus, were determined in post mortem samples. In naive lambs, high and relatively uniform worm burdens were present 10 days after primary infection and these were associated with only mild blood and tissue eosinophilia. By day 21 worm burdens were markedly lower and more variable. There was more evidence of eosinophil and mast cell accumulation in mucosa, and numbers in bone marrow were also higher than on day 10. However, neither EPA nor SMCP were detectable in lymph. By contrast, EPA and SMCP were present in substantial amounts in draining lymph within 48 h of challenge (secondary) infection of previously exposed lambs. EPA was inversely related to worm burdens recovered on day 10, as were abomasal mucosal and mucus SMCP concentrations. Elevated eosinophil numbers were also consistently detected in blood, bone marrow, mucosa and gastric lymph node. The results suggest that host immune defence against secondary, but not primary, exposure to O. circumcincta involves a rapidly mobilised local inflammatory component.