Effects of ovotransferrin on chicken macrophages and heterophil-granulocytes.

Ovotransferrin (OTF) is an acute phase protein in chickens, serum levels of which increase in inflammation and infections. To understand the significance of OTF in inflammation, we studied its in vitro effects on HD11 cells, a macrophage cell line, and heterophils isolated from blood using a panel of variables indicative of cellular activation. These included the production of interleukin-6 (IL-6), nitrite, matrix metalloproteinase (MMP), oxidation of dichlorofluorescein diacetate for respiratory burst and the degranulation of heterophils by the loss of fluorescein isothiocyanate positive cytoplasmic granules. The results show that ovotransferrin stimulates the production of IL-6, nitrite and MMP by HD11 cells and augments phorbol ester-induced respiratory burst. Ovotransferrin stimulated heterophils to produce IL-6, and MMP, but failed to produce nitrite, enhanced respiratory burst activity and degranulation. These results suggest that ovotransferrin can modulate macrophage and heterophil functions in chickens.

Density Segregation of Corn and Wheat Naturally Contaminated with Aflatoxin, Deoxynivalenol and Zearalenone.

Density segregation was used to reduce mycotoxin levels of corn samples naturally contaminated with aflatoxin or deoxynivalenol, and wheat samples naturally contaminated with deoxynivalenol or zearalenone. Corn kernels which were buoyant in saturated sodium chloride represented 3% of the total sample, yet contained 74% of the aflatoxin. Corn buoyant in water contained 51 and 14% of the total deoxynivalenol present in two naturally contaminated corn samples. Subsequent segregation of corn non-buoyant in water with 30% sucrose removed additional deoxynivalenol-contaminated kernels, resulting in the combined removal of 59 and 79% of the deoxynivalenol. Removal of deoxynivalenol-contaminated corn kernels with both water and 30% sucrose reduced the concentration of deoxynivalenol by 53 and 77%. Removing wheat buoyant in water and 30% sucrose decreased the deoxynivalenol present by 96 and 68%, and reduced the deoxynivalenol concentration by 96 and 67%. Removing wheat naturally contaminated with zearalenone buoyant in water and 30% sucrose combined resulted in no detectable zearalenone remaining in the non-buoyant fraction of the samples.

Mycotoxins - Their Biosynthesis in Fungi: Ochratoxins - Metabolites of Combined Pathways.

Little work has been done on the biosynthesis of ochratoxins. Nevertheless. a scheme based on known chemical and enzymatic reactions and incorporating known facts about ochratoxin biosynthesis is proposed as a working model. The scheme calls for formation of an unbranched pentaketide from acetyl and malonyl CoA, its cyclization and aromatization to an is ocoumarin, methylation and oxidation to the carboxy derivative which is chlorinated by chloroperoxidase before acyl activation for reaction with an ester of phenylalanine which arises via the shikimic acid pathway. The amide, ochratoxin A, is considered the final product of this biosynthetic pathway.