Pharmacokinetic study on pradofloxacin in the dog – Comparison of serum analysis, ultrafiltration and tissue sampling after oral administration

Background: Pradofloxacin, a newly developed 8-cyano-fluoroquinolone, show enhanced activity against Grampositive organisms and anaerobes to treat canine and feline bacterial infections. The purpose of this cross-over study was to measure the unbound drug concentration of pradofloxacin in the interstitial fluid (ISF) using ultrafiltration and to compare the kinetics of pradofloxacin in serum, ISF and tissue using enrofloxacin as reference. Results: After oral administration of enrofloxacin (5 mg/kg) and pradofloxacin (3 mg/kg and 6 mg/kg, respectively), serum collection and ultrafiltration in regular intervals over a period of 24 h were performed, followed by tissue sampling at the end of the third dosing protocol (pradofloxacin 6 mg/kg). Peak concentrations of pradofloxacin (3 mg/kg) were 1.55±0.31 μg/ml in the ISF and 1.85±0.23 μg/ml in serum and for pradofloxacin (6 mg/kg) 2.71±0.81 μg/kg in the ISF and 2.77±0.64 μg/kg in serum; both without a statistical difference between ISF and serum. Comparison between all sampling approaches showed no consistent pattern of statistical differences. Conclusions: Despite some technical shortcomings the ultrafiltration approach appears to be the most sensitive sampling technique to estimate pharmacokinetic values of pradofloxacin at the infection site. Pharmacokinetics – Pradofloxacin – Ultrafiltration – Dog – Oral Administration

High‐field (3 Tesla) MRI of the navicular apparatus of sound horses shows good agreement to histopathology

Magnetic resonance imaging and the correlation to histopathological findings of the equine palmar foot of lame horses have been described previously, using 0.27 and 1.5 T systems. Compared to these, 3 T systems provide superior spatial resolution and imaging contrast. The aim of our prospective anatomic study was to characterize the imaging anatomy of the navicular region on 3 T MRI in comparison to histopathological findings. We hypothesized that 3 T MRI allows a good visualization of the entire navicular apparatus and reliable measurements of navicular cartilage and cortical bone thickness. Twenty front feet of sound horses were examined using a 3 T MRI system. For histopathological examination, sagittal tissue sections of the navicular bones and adjacent ligaments were prepared. Alterations in magnetic resonance signal were graded for each region and compared to corresponding histological slices. Overall, there was good visualization of the anatomical detail and a very good agreement between MRI and histology for compact bone and spongiosa, good agreement for the fibrocartilage and the distal sesamoidean impar ligament, but only moderate agreement for the hyaline cartilage and the collateral sesamoidean ligament. A comparative measurement of cartilage and cortical bone thickness on magnetic resonance images and histological sections was performed. In MRI, the hyaline cartilage of the articular surface appeared significantly thinner and the fibrocartilage of the flexor surface appeared significantly thicker compared to histology. Findings indicated that MRI at a field strength of 3 T allows reliable depiction of anatomic details of the navicular apparatus

The role of diffusion tensor imaging as an objective tool for the assessment of motor function recovery after paraplegia in a naturally-occurring large animal model of spinal cord injury

Abstract Background Traumatic spinal cord injury (SCI) results in sensory and motor function impairment and may cause a substantial social and economic burden. For the implementation of novel treatment strategies, parallel development of objective tools evaluating spinal cord (SC) integrity during motor function recovery (MFR) is needed. Diffusion tensor imaging (DTI) enables in vivo microstructural assessment of SCI. Methods In the current study, temporal evolvement of DTI metrics during MFR were examined; therefore, values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were measured in a population of 17 paraplegic dogs with naturally-occurring acute SCI showing MFR within 4 weeks after surgical decompression and compared to 6 control dogs. MRI scans were performed preoperatively and 12 weeks after MFR was observed. DTI metrics were obtained at the lesion epicentre and one SC segment cranially and caudally. Variance analyses were performed to compare values between evaluated localizations in affected dogs and controls and between time points. Correlations between DTI metrics and clinical scores at follow-up examinations were assessed. Results Before surgery, FA values at epicentres were higher than caudally (p = 0.0014) and control values (p = 0.0097); ADC values were lower in the epicentre compared to control values (p = 0.0035) and perilesional (p = 0.0448 cranially and p = 0.0433 caudally). In follow-up examinations, no significant differences could be found between DTI values from dogs showing MFR and control dogs. Lower ADC values at epicentres correlated with neurological deficits at follow-up examinations (r = − 0.705; p = 0.0023). Conclusions Findings suggest that a tendency to the return of DTI values to the physiological situation after surgical decompression accompanies MFR after SCI in paraplegic dogs. DTI may represent a useful and objective clinical tool for follow-up studies examining in vivo SC recovery in treatment studies

Direct Evidence for the Importance of Small Animals to Prehistoric Diets: A Review of Coprolite Studies

Researchers tend to underestimate or ignore the importance of small animals to the prehistoric diet due to the difficulty of separating cultural from noncultural faunal debris excavated from sites. Human coprolite analyses (dessicated human feces) indicate prehistoric dietary consumption of small animals. The large number of coprolites analyzed from North America reveals direct ingestion of small animals and indicates that small animal remains from sites indeed reflect human dietary patterns. The coprolites reveal that reptiles, birds, bats, and a large variety of rodents were an important and prevalent component of the prehistoric diet