Pharmacokinetics of a single intravenous dose of marbofloxacin in adult donkeys

Six donkeys each received 2 mg/kg marbofloxacin as a 10 per cent aqueous solution administered intravenously. Principal pharmacokinetic parameters were determined and two efficacy indices were computed by using pharmacokinetic parameters and selected mic90 values of marbofloxacin against pathogenic equine strains to predict the efficacy of the drug at this dose. The pharmacokinetics of marbofloxacin in donkeys was characterised by a large mean volume of distribution at a steady state (1.15 [0.09] l/kg) and a long mean (sd) elimination half-life of 9.24 (1.96) hours. It was also characterised by a relatively slow total body clearance of 0.10 (0.02) l/kg/hour, slower than in horses. Using mic90 values of marbofloxacin against pathogenic equine strains with a daily dose of 2 mg/kg, appropriate values of efficacy indicators were obtained only for Enterobacteriaceae. Daily intravenous doses of 0.33, 2.62 and 20 mg/kg were calculated for evaluation in clinical trials of infections due to Enterobacteriaceae, Staphylococcus aureus and Streptococci, respectively.     

Fumonisin B-glucose reaction products are less toxic when fed to swine

The effects of fumonisin B-glucose reaction products in swine diets was examined. Pigs were fed diets containing 528 micromol of total fumonisin B/kg (FB), 528 micromol of total FB-glucose adducts/kg (FB-G, 122 micromol of unreacted FB/kg), or 0 micromol of total FB/kg for 15 days to test the efficacy of the FB-G reaction products in detoxifying FB. Weight gain in FB pigs was lower than in FB-G or controls, which was correlated with feed intake reduction in FB pigs. Serum aspartate aminotransferase, gamma-glutamyltransferase, and total bilirubin in FB pigs were higher than in FB-G or control pigs. Serum sphinganine/shingosine ratios in FB pigs were higher than in FB-G or control pigs. Microscopic examination of tissues from FB pigs showed generalized liver necrosis and apoptosis with marked cellular pleomorphism and disorganized hepatic cords. The liver and kidneys in the FB-G group appeared to be normal. Tissues of controls were free of lesions. Results suggest that dietary FB-G products are less toxic to swine and may provide an detoxification approach in instances of widespread FB grain contamination (p < 0.05).     

Pyrimidine nucleotide synthesis: regulatory control during transformation of lymphocytes in vitro

The incorporation of uridine into RNA in lymphocytes undergoing transformation induced by phytohemagglutinin parallels its incorporation into the intratcellular pool of acid-soluble nucleotides and coincides with a 20-fold increase in the specific activity of uridine kinase. This increase is dependent upon synthesis of both RNA and protein and is subject to both repression and end-product inhibition by cytidine.     

The war against blue mold

An epidemic of blue mold of tobacco unexpectedly attacked crops in the United States and Canada in 1979, causing an estimated loss of almost a quarter billion dollars. The disease, caused by a fungus, apparently started in Cuba where half the crop was destroyed in 1979 and 90 percent in 1980. Control of blue mold is difficult and expensive. Resistant cultivars become susceptible within a few years. A therapeutic fungicide, metalaxyl, gives efficient control, but resistant strains of the fungus may soon appear. Blue mold is an international problem that will require the collaboration of scientists, governments, and Industries for an adequate solution.     

Predatory Dinosaurs from the Sahara and Late Cretaceous Faunal Differentiation

Late Cretaceous (Cenomanian) fossils discovered in the Kem Kem region of Morocco include large predatory dinosaurs that inhabited Africa as it drifted into geographic isolation. One, represented by a skull approximately 1.6 meters in length, is an advanced allosauroid referable to the African genus Carcharodontosaurus. Another, represented by a partial skeleton with slender proportions, is a new basal coelurosaur closely resembling the Egyptian genus Bahariasaurus. Comparisons with Cretaceous theropods from other continents reveal a previously unrecognized global radiation of carcharodontosaurid predators. Substantial geographic differentiation of dinosaurian faunas in response to continental drift appears to have arisen abruptly at the beginning of the Late Cretaceous.