Alberto Estrada

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The effect of segregated early weaning (SEW) on postweaning small intestinal development was investigated in SEW and control (CON) pigs. Small intestines were collected from a total of 15 pigs killed at 11 (preweaning), 15 (3 d postweaning), and 34 d of age. At 3 d postweaning, the SEW and CON pigs had shorter villi (P<.01), deeper crypts (P<.01), and(More)
Saponins extracted from the seed of Chenopodium quinoa (quinoa) were studied for their ability to act as mucosal adjuvants upon their intragastric or intranasal administration together with model antigens in mice. Quinoa saponins, co-administered intragastrically or intranasally with cholera toxin or ovalbumin, potentiated specific IgG and IgA antibody(More)
The effect of beta-glucan, extracted from oats, on the enhancement of resistance to infections caused by Staphylococcus aureus and Eimeria vermiformis was studied in mice. In vitro study using macrophages isolated from the peritoneal cavity showed that beta-glucan treatment significantly enhanced phagocytic activity. In vivo study further demonstrated that(More)
Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used as adjuvants in the immunization of mice(More)
Previous studies have shown that beta-glucans extracted from yeast or fungi potentiate immune responses. In the present study, the immunomodulatory activities of beta-(1-->3,1-->4)-glucan, derived from oats, were investigated. The ability of oat beta-glucan (ObetaG) to stimulate IL-1 and TNF-alpha release from murine peritoneal macrophages and the murine(More)
We have identified saponins in the root of Polygala senega L., a plant indigenous to the Canadian prairies, which display immunopotentiation activity to protein and viral antigens. By two-step extraction and hemolytic activity-guided fractionation by silica flush chromatography six saponin fractions were generated and their HPLC profiles determined. Two(More)
Synthetic, biotinylated somatostatin-14 (Somatotropin Release-Inhibiting Factor; SRIF) was conjugated to avidin, and the resulting complex incorporated into immune-stimulating complexes (ISCOMS). The ISCOMS were used to study the systemic and mucosal immune responses induced by parenteral and gastrointestinal vaccination. Mice were immunized by(More)
The effect of intragastrically or parenterally administered beta-glucan, extracted from oats, on the enhancement of disease resistance to Eimeria vermiformis was studied in C57BL/6 mice. Groups of mice were immunosuppressed with dexamethasone (DXM), infected with oocysts of E. vermiformis and treated with oat beta-glucan by the intragastric (i.g.) or(More)
In order to assess the effect of oat beta-glucan (ObetaG) administration on immune parameters of beef steers, 3 experiments were carried out. In experiment 1, the in vitro effect of ObetaG on the proliferation of blood lymphocytes, with or without the presence of dexamethasone (DXM), was evaluated. In experiment 2, groups of 12 healthy steers were(More)
Previous studies have shown that endotoxin potentiates immune responses by direct stimulation of B cells and macrophages. In the present study, we assessed the ability of endotoxin to stimulate cells from different lymphoid tissue compartments to release cytokines. The in vitro stimulation of macrophages with endotoxin resulted in the production of IL-1 and(More)