Concentrations of buparvaquone in milk and tissue of dairy cows.

AIM: To determine the concentration of the anti-theilerial drug buparvaquone in the milk and tissue of dairy cattle following treatment with two different formulations, and to assess the effect of clinical theileriosis on the concentration of buparvaquone in milk. METHODS: Healthy lactating dairy cows (n=25) were injected once (Day 0) I/M with 2.5 mg/kg of one of two formulations of buparvaquone (Butalex; n=12 or Bupaject; n=13). Milk samples were collected from all cows daily until Day 35. Five cows were slaughtered on each of Days 56, 119, 147, 203 and 328, and samples of liver, muscle and injection site tissue collected. Milk samples were also collected from cows (n=14) clinically affected with theileriosis for up to 21 days after treatment with buparvaquone. Milk and tissue samples were analysed by liquid chromatography-mass spectrometry; limits of detection (LOD) were 0.00018 mg/kg for muscle and 0.00023 mg/L for milk. Concentrations of buparvaquone in milk and tissues were log10-transformed for analysis using multivariate models. RESULTS: In healthy cows, concentrations of buparvaquone in milk declined with time post-treatment (p<0.001), but were above the LOD in 11 of 25 cows at Day 35. Concentration in milk was higher one day after treatment in cows treated with Butalex than in cows treated with Bupaject, but not different thereafter (p=0.007). Concentrations of buparvaquone in muscle were below the LOD for four of five animals at Day 119 and for all animals by Day 147, but were above the LOD at the injection site of one cow, and in the liver of three cows at Day 328. Tissue concentrations did not differ with formulation nor was there a formulation by time interaction (p>0.3). Concentrations of buparvaquone in the milk of clinically affected animals were not different from those of healthy animals at 1 and 21 days post-treatment (p=0.72). Between 21 and 25 days post-treatment concentrations were below the LOD in 9/14 milk samples from clinically affected cows. CONCLUSIONS: Detectable concentrations of buparvaquone were found in the milk of some cows for at least 35 days and in the liver and injection site of some cows until at least 328 days after injection. There were no biologically meaningful differences in milk or tissue concentrations between the formulations, or in the milk concentrations for cows that were clinically affected compared with those that were healthy at the time of treatment.

Serologic survey of woodchuck hepatitis virus in North Carolina woodchucks (Marmota monax).

The prevalence of woodchuck hepatitis virus (WHV) in wild populations of woodchucks is understudied and therefore unclear. Although infection is common in the southeastern region of Pennsylvania and surrounding states, it is virtually absent in New York and New England. Sera were collected from wild woodchucks from Orange County, North Carolina and tested for the presence of markers of current or previous infection with WHV. Of the 24 woodchucks tested, there were three animals (12.5%) with WHV surface antigen as well as antibodies to woodchuck hepatitis core antigen in their serum, indicative of active infection. There were four (17%) animals with antibodies to WHV core antigen but no woodchuck hepatitis surface antigen, indicative of prior infections. The remaining 17 animals had no detectable markers of WHV infection. These data indicate that WHV is present in central North Carolina at rates approaching those seen in endemic areas, such as the mid-Atlantic region of the United States.

Evaluation of inorganic pyrophosphate in amniotic fluid as a mode of prenatal diagnosis of osteogenesis imperfecta.

Using a modified procedure by Solomons and Styner (1969), an evaluation of inorganic pyrophosphate (PPi) was performed on the amniotic fluid of two fetuses at risk for osteogenesis imperfecta (OI) at 14 1/2 weeks gestation. The parents of both cases had a previous child with OI, Type II. The normal control group at 14-16 weeks gestation had PPi values ranging from 22.0-59.2 micrograms/100 ml, with a mean of 38.6 +/- 9.51 micrograms/100 ml. In each at-risk fetus, the amniotic fluid PPi value was within normal range. The first baby was born phenotypically normal at term. Intrauterine radiographic and fetal sonograms were done on the second fetus at approximately 19 weeks gestation. Both showed evidence of OI, Type II. The pregnancy was terminated at 21 weeks. Radiologic studies of the aborted fetus were consistent with OI, Type II. Our results indicate that the evaluation of PPi levels in amniotic fluid is not the method of choice for prenatal diagnosis of OI.