Biomedical subjects

H H Casper

Publications and source records attributed to H H Casper.

23 records · Page 2Linked to original sources

PubMedDate not supplied

Fluoroacetate residues in ground squirrel and coyote tissues due to primary or secondary 1080 poisoning.

Fluoroacetate residues in various tissues of 1080-poisoned ground squirrels and coyotes are listed. The tissues (excluding the stomach) of squirrels poisoned with an average of 0.8 mg 1080/kg (low dose) contained from 182 to 1309 ppb fluoroacetate. In squirrels poisoned with an average of 4.8 mg 1080/kg (high dose), the tissue residues ranged from 535 to 9754 ppb fluoroacetate. Tissues from coyotes which died after consuming 1080-poisoned ground squirrels were also analyzed for fluoroacetate residues. Residues in these coyote kidneys and livers ranged from less than 10 ppb to 95 ppb fluoroacetate. The residue findings in this research indicate that a diagnostic assay for 1080 in tissues must be reliable at 10 ppb (or less) fluoroacetate.

Animals↗

PubMedDate not supplied

Capillary gas chromatographic-mass spectrometric determination of fluoroacetate residues in animal tissues.

A method for the quantitative determination of fluoroacetate (FAC) residues in animal tissues is described. The procedure involves tungstic acid extraction, partitioning into ethyl acetate, evaporation of ethyl acetate, derivatization with pentafluorobenzyl bromide (PFB), and analysis of the resulting derivative (PFB-FAC) by capillary gas chromatography-mass spectrometry (CGC-MS) with specific ion monitoring (SIM). The tungstic acid system extracted 96.8 +/- 4.2% of the endogenous 14C-1080 residues in rat tissues. Recovery of FAC during the extraction, purification, and derivatization procedures is established by use of a 14C-FAC spike. 1,2-Dibromobenzene is used as an internal standard for the CGC-MS analysis. PFB-FAC is identified on the basis of comparative retention times and the relative intensities of m/z 257.9 and 181.0. PFB-FAC is quantitated by comparing the response at m/z 257.9 to a PFB-FAC standard curve. Routine sensitivity of the method allows determination of 10 ppb fluoroacetate in tissue.

Animals↗

PubMedDate not supplied

Forage nitrate analysis: laboratory performance study.

Four forage samples were analyzed by 16 laboratories for KNO3 content. Individual reported KNO3 values varied widely for each sample; coefficients of variation for the 4 samples were 36.0, 51.0, 12.8, and 55.0%. Recovery of KNO3 from the spiked sample averaged 105%. The analytical results, as a group, were unacceptable both statistically and for use in feeding recommendations. Three values reported could have resulted in feeding potentially toxic forage to livestock.

Nitrates↗

PubMedDate not supplied

Determination of deoxynivalenol in wheat, barley, and malt by column cleanup and gas chromatography with electron capture detection.

A rapid and reliable method to determine deoxynivalenol (DON) in wheat, barley, and malt is described. Samples are extracted with acetonitrile-water (84 + 16). Extracts are eluted through a C18-alumina (1 + 3) column, evaporated to dryness, and derivatized with trimethylsilylimidazole-trimethylchlorosilane (100 + 1). DON is identified and quantitated by capillary gas chromatography with electron capture detection. This method can quantitate DON levels from 0.2 to 40 ppm. Multiple analyses of wheat spiked at 2 ppm and of naturally contaminated wheat, malt, and barley resulted in coefficients of variation of 5.1, 5.1, 6.0, and 9.8%, respectively. Recoveries of DON spikes at 3 levels were 94-100% for wheat, 100-105% for barley, and 100-105% for malt. Results for wheat sample analyzed with this procedure (1.9 +/- 0.1 ppm DON) compared well with results for the same sample analyzed by enzyme-linked immunosorbent assay (1.9 ppm DON) and by liquid chromatography (1.7 ppm DON).

Chromatography, Gas↗

PubMedDate not supplied

Moniliformin from Fusarium fujikuroi culture material and deoxynivalenol from naturally contaminated wheat incorporated into diets of broiler chicks.

The effects of feeding diets containing 100 mg moniliformin (M)/kg of feed from culture material and 16 mg deoxynivalenol (DON)/kg of feed from naturally contaminated wheat were evaluated in growing broiler chicks from 1 day to 21 days of age. Body weight (BW), body-weight gain, and feed consumption were decreased by feeding M and M plus DON diets. Relative heart weight was increased by the M diet, whereas relative weights of proventriculus, gizzard, and heart were increased by the M plus DON diet. The M diet increased alanine transferase and aspartate transaminase activities and creatinine concentration and decreased mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration (MCHC). The M and DON diet decreased glucose, hemoglobin, and MCHC. Histopathological lesions from the M diet were limited to the kidney and consisted of extensive renal tubular epithelial degeneration plus luminal mineralization. A moderation of the severity of lesions was seen in the tissues of the M plus DON-fed chicks, consisting of generally mild tubular epithelial degeneration. None of the parameters measured were affected by the DON diet. Results indicate additive or less-than-additive toxicity for most parameters when chicks were fed diets containing 100 mg M plus 16 mg DON/kg of feed. Although the concentration of M in this study was high compared with that reported for feedstuffs, additional information on the occurrence and toxicity of M will need to be collected in order to assess the importance of M to the poultry industry.

Alanine Transaminase↗