Evaluation of XPC and prototypes on aflatoxin-challenged broilers.

Various products and prototypes were added to poultry diets during an aflatoxin challenge on growth and histological parameters. Male broiler chicks were randomly assigned to 8 treatment groups with 8 replicates/treatment and 3 birds/replicate. Treatments were as follows: 1) negative control containing no aflatoxin (NC); 2) positive control containing aflatoxin (PC); 3) 0.1% glucomannan mycotoxin standard industry ameliorator (STD); 4) 0.1% prototype A, a proprietary mixture of a Saccharomyces cerevisiae product and diatomaceous clay; 5) 0.2% prototype A; 6) 0.15% prototype B, a proprietary mixture of a S. cerevisiae product and diatomaceous clay (PB); 7) 0.0625% XPC (S. cerevisiae fermentation product); and 8) 0.125% XPC (XPC2). All treatments except NC contained 2,280 +/- 102 ng/g of aflatoxin and were fed for 28 d. Body weight and feed intake were measured weekly. Livers were collected on d 28, weighed, and used for histopathological evaluation. Beginning weights were similar across treatments, but BW were lower (P /= 0.05) different among the treatment groups. Liver weights relative to BW were higher (P /= 0.05) compared with NC. Overall, BW gain in treatment groups PB and XPC2 was not different from NC and that corresponded to protective effects against liver lesions. Benefits observed during an aflatoxin challenge when broilers were supplemented with XPC, a fermentation product that does not contain any adsorbents, may be attributed to something other than adsorption as a primary mechanism.

Ampicillin pharmacokinetics in swine following needle-free, intramuscular, and intravenous administration.

A cross-over study design was used to determine the pharmacokinetics of ampicillin in swine. Each of eight pigs was subjected to all of the following three treatments: (1) intramuscular (i.m.) injection of 17.6 mg/kg of ampicillin trihydrate; (2) injection of a mean dose of 17.6 mg/kg of ampicillin trihydrate using a needle-free (NF) injection device; and (3) intravenous injection of 17.6 mg/kg of sodium ampicillin administered as a bolus. Ampicillin trihydrate administered by NF injection in this study was not statistically different from i.m. injection as measured by AUC(0-infinity), MRT, MAT, or Cmax. However, the 90% confidence limits about the difference in NF to i.m. mean Cmax and AUC(0-infinity) values, expressed relative to the i.m. treatment mean, exceeded the traditional bioequivalence limits of +/-20%. In part, failure to demonstrate bioequivalence was attributable to small study size and the large within-subject variability associated with this drug. Therefore the power of this study was not sufficient to definitively prove or disprove bioequivalence and additional studies to describe appropriate dosage regimens for ampicillin trihydrate when administered by NF injection to pigs are warranted.

Cotton liners to mediate glove comfort for greenhouse applicators.

Greenhouse applicators' acceptance of cotton knit gloves worn as liners under nitrile chemical-resistant gloves (CRG) for pesticide application was investigated through a wear study in Iowa and New York. Comfort was assessed by questionnaires and interviews with 10 applicators. Contamination levels of four pesticides on CRG and liners at thumb, forefinger, palm, and cuff locations were determined by chemical analysis using high-performance liquid chromatography or gas chromatography. Applicators reported feeling more comfortable with cotton liners under their CRG than without and that cotton liners were easy to manage. Contamination was significantly greater on nitrile CRG than on cotton liners underneath, but a few liner specimens had measurable contamination. No significant contamination differences were found between right- and left-hand gloves. Contamination varied significantly by hand location, with cuffs least, and by pesticide, with chlorpyrifos most. These results support the Environmental Protection Agency's recommendation that liners should be disposable, but further work on liners and their laundering feasibility seems indicated.

New, sensitive high-performance liquid chromatography method for the determination of slaframine in plasma and milk.

Slaframine was derivatized precolumn with fluorescamine. The derivatized slaframine was chromatographed isocratically using HPLC on a Hamilton PRP-1 C18 polymeric column with fluorescence detection. By using fluorescent derivatization, sensitivity was increased 100-fold over previously reported GC methods. A liquid-liquid partition was used to extract slaframine from plasma with a 95% recovery and a CV% of 8.4. A solid-phase extraction was used to extract slaframine from milk with a 91% recovery and a CV% of 9.8.

pH method for determination of cholinesterase in whole blood: collaborative study.

A collaborative study of an indirect method for determination of cholinesterase activity was conducted with cattle blood. Ten collaborators analyzed 8 samples of varying degrees of cholinesterase inhibition. The sample is diluted with a buffer, and the pH change that results from the hydrolysis of acetylcholine is monitored. Repeatability relative standard deviations (RSDr) ranged from 6.6 to 8.6%, and reproducibility relative standard deviations (RSDR) ranged from 10.7 to 17.3% for mean activities of 0.60-0.40 delta pH/h. All samples that were completely inhibited were detected. The method was adopted first action by AOAC International for determination of cholinesterase activity in whole bovine blood.