ovalbumin and calcium-phosphate--dibasic--anhydrous

Aluminum hydroxide (Al) and calcium phosphate (Ca) gels have been used as vaccine adjuvants for many years. We investigated mechanism of the hemolytic activities of both adjuvant materials. The hemolytic activity of each gel depended on the gel dose. The adsorption capacities and the hemolytic activities of both adjuvants decreased as the concentration of phosphate increased in a gel-washing solution. A positive correlation between the hemolytic activity and the adsorption capacity was found in Al-gel. A disruptive effect of Ca-gel on membrane of erythrocytes was shown by electron microscopy. Ca-gel required more than 10 times as much pre-adsorbed ovalbumin as did Al-gel to inhibit the hemolysis. These results suggest that the hemolytic activity of both adjuvant materials depended mainly on the adsorption ability, and it may be useful to control the adsorption ability of adjuvants to reduce their hemolytic activity.

Topics: Adjuvants, Immunologic; Adsorption; Aluminum Hydroxide; Animals; Calcium Phosphates; Erythrocyte Membrane; Female; Gels; Guinea Pigs; Hemolysis; Microscopy, Electron, Scanning; Ovalbumin; Phosphates

Two experiments were conducted to determine the effects of dietary vanadium (V) on egg albumen quality. In Experiment 1, White Leghorn hens fed 9.9 ppm V supplied from a commercial dicalcium phosphate (Dical B at 1.5% of the diet) or a diet containing 29.9 ppm V (28.5 ppm from ammonium vanadate and 1.4 ppm from Dical A) produced eggs with significantly poorer albumen quality (61.7 and 61.6 Haugh units, respectively) than those of hens fed 1.4 ppm V from Dical A (76.9 Haugh units). The decline in albumen quality occurred within 1 week of treatment and persisted through 4 weeks of V feeding. Inclusion of 28.5 ppm V as ammonium vanadate also reduced egg production and feed consumption but had no significant effect on egg weight or change in body weight during the 4-week test period. At the end of 4 weeks, all hens were fed the 1.4-ppm V diet. Improvement in albumen quality was observed within 1 week, and after 4 weeks of the recovery period, no significant differences among treatment groups were observed. Part 1 of Experiment 2 showed that albumen quality was significantly reduced by 6.0 and 7.9 ppm V, supplied from Dical B, but 2.0 or 4.0 ppm V did not significantly change albumen quality during a 4-week trial. In Part 2 of Experiment 2, the inclusion of 9.9 ppm V from Dical B again significantly reduced albumen quality within 1 week. The magnitudes of adverse effects of 6.0, 7.9, and 9.9 ppm V on albumen quality plateaued approximately 4 weeks after treatment began and remained relatively constant through 6 weeks of feeding 9.9 ppm V and through 10 weeks of feeding 6.0 or 7.9 ppm V. The results demonstrate that certain commercial dicalcium phosphates may contribute excessive V to the diet of hens, and, when present at levels of 6.0 ppm or more, V will adversely affect albumen quality.

Topics: Animals; Body Weight; Calcium Phosphates; Chickens; Diet; Egg White; Female; Ovalbumin; Oviposition; Vanadium