Some azo dyes, including Sudans I–IV and Para Red, are genotoxic and may be biotransformed to cancerogenic aromatic amines. They are banned as food and feed additives, but their presence has been detected in food. Aromatic amines are also considered potentially toxic. Online EC–MS is a promising tool to study the transformation mechanisms of xenobiotics such as azo dyes. The aim of the study was to investigate emulation of how azo dyes are enzymatically transformed to amines with EC–MS. The reduction reactions of five azo dyes (Sudans I–IV and Para Red) were conducted using a glassy carbon working electrode and 0.1% formic acid in acetonitrile. Reduction results were compared with the literature and in silico to select preliminary candidates for metabolites. The LC-MS/MS method was used to confirm results obtained by electrochemical reactor. A limited number of pre-selected compounds were confirmed as azo dyes metabolites – aniline for Sudan I, aniline and 4-aminoazobenzene for Sudan III, o-toluidine for Sudan IV, and 4-nitroaniline for Para Red. No metabolites were found for Sudan II. Electrochemistry–mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation.

Tracheal mucus transport rates were measured over a 10-minute period in 20 healthy horses twice in 24 hours. The mean rate was 1.93 +/- 0.55 cm/min on day 1 and 1.99 +/- 0.49 cm/min 24 hours later. The mean difference between day 1 and day 2 (0.06 +/- 0.42 cm/min) was not significant (P = 0.55). The range on day 1 was 1.12 to 2.9 cm/min and 1.11 to 2.89 cm/min on day 2.

The lungs of sensitized horses were exposed to aerosolized ovalbumin. Some horses (n = 4) were given ovalbumin in 1 lung only, whereas in others (n = 7), ovalbumin or vehicle were inoculated in the cranial, ventral, and caudal regions of the caudal lung lobe. Horses were exercised 5 hours after ovalbumin exposure. Immediately before exercise, endoscopy failed to reveal any abnormality. After exercise, endoscopic examination of horses subjected to unilateral ovalbumin exposure revealed extensive blood in airways leading to the exposed lung in all horses. Blood was not observed in the airways leading to the control lung. Mean (+/- SEM) minimum volume of the exposed and control lungs was 9.5 +/- 1.5 and 5.5 +/- 1.6 L, respectively; this difference was statistically significant (P < 0.05). Bronchoscopy of horses subjected to regional ovalbumin or vehicle exposure and exercise revealed a small amount of blood-tinged fluid in the bronchi serving the regions of the lung inoculated with ovalbumin. Minimum volumes of such regions were not significantly different from one another. However, their minimum volume was significantly (P < 0.05) larger than that of vehicle-inoculated regions. Gross and histologic examination confirmed inflammation and hemorrhage in the ovalbumin-exposed, but not the control lungs or lung regions. Thus, exercise can cause blood from an injured region of lung to appear in the larger airways. Regional differences in lung structure and function do not influence the appearance of blood in the airways.

In 5 horses, 13CO2/12CO2 ratios in expired air were determined using isotope mass spectroscopy to investigate metabolism of naturally occurring [13C]glucose. Oral glucose tolerance tests (OGTT) were performed using maize or beet glucose. Maize has a higher 13C concentration than that of most plants. The 13CO2/12CO2 ratios after OGTT was performed using maize glucose were compared with 13CO2/12CO2 ratios in expired air after OGTT was performed using beet glucose. The ratio also was determined during the period horses were not fed. Using OGTT, all horses were glucose tolerant. The OGTT performed using beet glucose led to minimal changes in 13CO2/12CO2 ratios. The 13CO2/12CO2 ratios decreased significantly (P less than 0.01) when horses were not fed. After oral dosing with maize glucose, 13CO2/12CO2 ratios reached maximal increases 5 hours after dosing and reached baseline values 15 hours after dosing.

Refined, Bleached and Deodorized Palm Stearin (RBDPS) is a solid fraction obtained from Refined, Bleached and Deodorized Palm Oil after fractionation by crystallization at controlled temperature. Fractionated RBDPS was found to be enriched with C16 fatty acids,&#xD;lacking in trans fat and has a high melting point. The fractionated RBDPS produced had an iodine value of 13.1 gI2/100g, C16 content of 79.7% and melting point 60°C .These characteristics indicate fractionated RBDPS has potential as a rumen bypass fat as well as providing desirable carbon chain composition for good milk characteristics.