We examined the effect of infusion of lipopolysaccharide (LPS) on serum tumor necrosis factor alpha (TNF alpha) concentration and clinical attitude in 2- to 3-day-old colostrum-fed (CF) and colostrum-deprived (CD) foals. Eleven CF and 8 CD neonatal foals were given a bolus IV infusion of Escherichia coli 055:B5 lipopolysaccharide (0.5 microgram/kg of body weight) in sterile saline (0.9% NaCl) solution. Four CF and 2 CD foals were given saline solution alone. Serum IgG concentration and serum anti-LPS IGG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum TNF alpha concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as TNF alpha by immunoprecipitation with caprine antisera raised against the 15 NH2-terminal amino acids of human TNF alpha. Tumor necrosis factor alpha was not detected in any preinfusion serum samples nor in any samples from foals given saline solution alone. Serum TNF alpha concentration increased in all LPS-infused foals and peaked between 60 and 90 minutes after infusion. Serum TNF alpha concentrations, expressed as mean percentage of peak serum TNF alpha concentration, persisted longer in CD foals given LPS than in CF foals given LPS. All LPS-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the CF and CD foals given LPS were not significantly different at any time. Serum TNF alpha concentrations were correlated with depression index scores in both LPS-infused groups. Mean rectal temperature increased by 1 hour and remained high for 4 hours after infusion in CF foals given LPS. Mean rectal temperature in CD foals given LPS was significantly less than that for CF foals given LPS 1 and 2 hours after infusion and was higher than mean rectal temperature prior to infusion 3 and 4 hours after.

Ten healthy first- and second-lactation Holstein cows were observed from 1 week before to 1 week after calving and at postpartum day 30 to determine polymorphonuclear neutrophil (PMN) functional variation and immunoglobulin binding profiles. Blood and mammary PMN were obtained 3 times weekly and within 24 hours of calving. Functional traits measured included phagocytosis of Stapbylococcus aureus and in vitro chemotaxis through micropore filters in a Boyden chamber. Additionally, PMN were evaluated for endogenous binding of IgG1, IgG2, IgA, and IgM before and after in vitro chemotaxis. Exogenous binding of the same isotypes was determined after incubation in pooled colostrum, purified immunoglobulin, and pooled sera. Phagocytosis results indicated a significant and transient increase in percentage of milk PMN with associated, rather than phagocytosed, bacteria for 1 week after calving. Blood PMN phagocytosis was not significantly different during this period. Though total chemotaxis was essentially unchanged, the percentage of PMN that were unable to complete migration increased substantially on the day of calving, an effect that disappeared by postpartum day 4. A significant (P < 0.01) positive correlation (r = 0.29) between percentage of PMN migrating completely through the micropore filter and percentage of blood PMN with associated bacteria was observed. Changes were not observed in endogenous immunoglobulin binding, with the exception of a peak in relative fluorescence intensity for IgG1 on the day of calving; this disappeared within 2 days after calving. Correlations between relative intensities of IgG2, and IgM, and percentage of mammary neutrophils phagocytosing were 0.37 and 0.70. Exogenous binding of antibody to blood neutrophils before chemotaxis was generally accomplished most effectively by pooled colostrum, whereas use of pooled sera markedly reduced binding and percentage and intensity of IgM in all cases. Binding of all isotypes was slightly higher before than after calving. Incubation of blood neutrophils in isotypes G1, G2, A, and M after chemotaxis yielded lower immunoglobulin binding among all isotypes, particularly IgM. Fluctuations in neutrophil function were observed immediately around parturition, and these changes correlated strongly with endogenous immunoglobulin-binding profiles.

Akabane virus (AKV) strain OBE-1 was inoculated IV into 17 pregnant sheep. Ten fetuses infected at 29 to 45 days of gestation and examined 29 to 30 days later had AKV antigen in the following groups of cells: neuroglial cells in the brain and spinal cord, ganglion cells in the cranial and abdominal ganglia, layer of ganglion cells in the retina, ganglion cells (Auerbach's plexus) in small intestine, hepatocytes, cells in the arterial wall of mesenteric membrane, and trophoblast cells in the placenta. Prior to detection of circulating virus-neutralizing antibody, immunoglobulin-containing cells were found initially at 59 days of gestation in the peripheral portion of white pulp tissue in the spleen. After that, numbers of immunoglobulin-containing cells gradually increased. These results indicated that AKV may have strong affinity for neuronal and ganglional cells in infected fetuses and immunoglobulin-containing cells might be considered the earliest immunologic response to AKV replication in the fetus.

Using polyclonal rabbit and monoclonal mouse anti-dog IgE antibodies, we developed ELISA for measurement of ragweed-specific IgE in canine serum. In the ELISA, microtitration plates were coated with ragweed extract and sequentially incubated with canine serum, purified monoclonal or polyclonal anti-dog IgE, and conjugated goat antibody to mouse IgG or rabbit IgG. Serum ragweed-specific IgE values were measured by the 2 ELISA in serum samples from 60 ragweed-allergic dogs and in serum from 10 control dogs. Passive cutaneous anaphylaxis (PCA) tests were performed on these sera to compare results with those of the ELISA, Mean coefficient of variation between assays was 0.20 +/- 0.10 for the assay using the polyclonal antibody and was 0.17 +/- 0.10 for that using monoclonal antibody. Sensitivity was 0.6 U/ml for the ELISA, using polyclonal antibody, and 2.5 U/ml for the ELISA, using monoclonal antibody. Serum ragweed-specific IgE values measured by the 2 ELISA strongly correlated with PCA titers (P < 0.0000), but the ELISA using polyclonal antibody had higher correlation with PCA titer (r = 0.84) than the ELISA using monoclonal antibody (r = 0.59). The geometric mean ragweed-specific IgE value measured by the 2 ELISA and by PCA testing, was significantly higher (P < 0.0000) in allergic dogs than in control dogs. The 2 ELISA were specific, sensitive, and reproducible for measurement of ragweed-specific IgE in canine serum.

Chicken egg yolk IgG can be absorbed and transferred as efficiently as colostral antibodies in the blood of neonatal pigs. Egg yolk IgG has a half-life of 1.85 days in newborn pig serum. This is shorter than the reported half-life (12 to 14 days) of homologous IgG in serum of pigs. Similar to colostral antibodies, egg yolk IgG absorption from intestine ceased at about 34 hours of age, after a logarithmic decrease in absorption rate from birth. Egg yolk IgG absorption inhibition time in the gastrointestinal tract took 1.73 hours to decrease by half. Egg yolk IgG was protective against experimentally induced diarrhea in pigs when it was administered at high dose, and multiple dosing was instituted. Adverse effects were not observed when chicken egg yolk IgG was administered orally to pigs.