Determination of Oxytetracycline/Oxytetracycline Hydrochloride in Animal Feed, Fish Feed, and Veterinary Medicinal Products by Liquid Chromatography with Fluorescence Detection: Collaborative Study

A method for determining oxytetracycline (OTC) in animal feed, fish feed, and veterinary medicinal products at medicated use and contamination levels was collaboratively studied. The method is applicable to the analysis of animal feeds and mineral premixes containing levels 2 mg/kg, and fish feed containing levels 10 mg/kg. Oxytetracycline hydrochloride (OTC.HCl) is extracted from ground feed material in acidmethanol solution using mechanical agitation. After centrifugation for 5 min at 1230 g, an aliquot of the extract is diluted with water and/or acidmethanol so that the concentration of OTC.HCl is approximately the same as that in the working standard, and the solutions contain at least 50 water. Injectable veterinary medicinal materials (also called animal remedy materials) are diluted with water and/or extractant to reach the target concentration. The extracts are filtered and analyzed by reversed-phase liquid chromatography with fluorescence detection with excitation at 390 nm and emission at 512 nm. Twenty-eight test samples of medicated feeds, supplements, and drug premixes, including 4 test samples for trace-level analysis, were sent to 17 collaborators in Canada, The Netherlands, and the United States. Results were received from 11 laboratories. The RSDr values (within-laboratory repeatability) ranged from 1.26 to 9.21; RSDR values (among-laboratory reproducibility) ranged from 2.14 to 12.9, and HorRat values ranged from 0.54 to 3.02. It is recommended that this method be adopted AOAC Official First Action.

Determination of Decoquinate in Animal Feeds by Liquid Chromatography: Collaborative Study

The performance characteristics of a liquid chromatographic (LC) method for the analysis of decoquinate (DEC) in supplements, premixes, and complete animal feeds at medicating and trace levels were collaboratively studied. DEC is extracted from ground feed samples with 1 calcium chloridemethanol solution using mechanical agitation for 90 min. After centrifugation for 5 min and dilution (if necessary), an aliquot of the extract is diluted with water. The diluted extracts are filtered and analyzed by reversed-phase LC with fluorescence detection. Suspect positive trace-level samples are confirmed by using an alternate excitation wavelength. Fourteen test samples of medicated feeds, supplement, and medicated premix, along with 8 test samples for trace-level analysis, were sent to 13 collaborators (one in Canada, 4 in Europe, and 8 in the United States). Test samples were analyzed as blind duplicates. Acceptable results were received from 12 laboratories for the medicated test samples and from 13 laboratories for the trace-level samples. Repeatability relative standard deviation estimates ranged from 1.3 to 5.6. Reproducibility relative standard deviations estimates ranged from 2.8 to 6.1, and HorRat values ranged from 0.22 to 0.74.

Health-related quality of life and pain assessment in 36 patients with resected pancreas adenocarcinoma: Preliminary analysis

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Background: In order to begin to understand the effects of disease on the patient (pt) and possibly of the pt on the disease, we have begun a systematic psychological inventory of all our pts who have has a pancreatectomy for pancreas adenocarcinoma and have began to correlate this with disease extent, and later with survival. Methods: Prior to post-op discharge home, pts were invited to fill out a brief pain inventory (BPI-SF), BPI interference, emotional (EWB) and physical well-being score (Fact-Hep), as well as social/family and functional well-being (FWB) Fact-Hep. The data was entered into a database, together with pertinent lab results, tumor markers, and tumor characteristics from the pre-op CT scan and post-op pathology report. Data was analyzed by descriptive statistics, frequencies and Pearson Correlation (2-tailed sig). Results: Descriptive means (and ranges) were - tumor size 3.43 cm mean (2.0 min-5.2 max), bilirubin 1.26 (0.2–4.7), albumin 2.69 (1.5–3.6), Hb 10.3 (7.5–13.2), platelets 254K (109K-672K), CEA 4.7 (0.8–24), and Ca 19–9 was 987 (1.0–8127). Pain at presentation pre-op of moderate severity was present in 11% of pts and severe pain was present in 5.6% of pts (16.6% total). Pathologically, LNs were involved by cancer in 50% of pts, vascular invasion in 30%, neural invasion in 35% and any margin positive in 14%. 22% had metastases noted at surgery. Statistically significant correlations were found for tumor size and pain severity (p<.035), platelets and FWB (p<.022), albumin and Hb (p=.000), CA 19–9 and bilirubin (p<.030 i.e. high CA 19–9 and high bilirubin). There was a negative correlation between CEA (but not CA 19–9) and both EWB (p<.039) and FWB (p<.035). Pain severity correlated with depressed mood (p<.010), lower physical well-being (p<.01) and interference with life activities (p<.01). Conclusions: CEA, but not CA 19–9 correlated with both emotional and functional well-being. Baseline pain was present in only 16.6% of this cohort. We plan to follow up to examine how these parameters correlate with pt coping throughout therapy and survival.

No significant financial relationships to disclose.

Prenatal weight gain within upper and lower recommended ranges: effect on birth weight of black and white infants

OBJECTIVE

To that end examine differences in birth weight among the term infants of black and white women with weight gains in the upper or lower half of recommended ranges.

METHODS

Birth weight (mean, low [at or below 2500 gl, and suboptimal [2501-2999 g]) among term infants of 2219 black and 3966 white low-income women was compared with maternal prenatal weight gain classified according to four categories: below, within the lower or upper halves, and above the recommended ranges for pregravid body mass index (BMI) category (low, normal, high).

RESULTS

Adjusted mean birth weights among the infants of women with prenatal weight gain in the upper versus lower half of the recommended ranges were higher among white women with normal BMI (3307 g upper half, 3199 g lower half, P = .001) but not among black women with normal BMI (3180 g upper half, 3105 g lower half, not significant). Logistic regression analyses revealed that prenatal weight gain in the upper compared with the lower half of the recommended ranges was associated with a decreased adjusted odds ratio (OR) for low (but not suboptimal) birth weight among the infants of white women (OR 0.4, 95% confidence intervals [CI] 0.2,0.9) but not of black women (OR 1.2; 95% CI 0.4,3.3).

CONCLUSION

These preliminary observations do not provide support for the presence of ethnic group-specific recommendations within guidelines for prenatal weight gain.