Objective—To evaluate chemotactic, phagocytic, and
bactericidal activities of bovine and porcine alveolar
macrophages (AM) exposed to tilmicosin.
Animals—12 healthy calves and 12 healthy pigs.
Procedure—Lungs were obtained immediately after
euthanasia; AM were collected by means of bronchoalveolar
lavage and density gradient centrifugation.
Chemotactic activity was evaluated by exposing
AM to lipopolysaccharide or macrophage inhibitory
peptide during incubation with tilmicosin. Phagocytic
activity was evaluated by incubating AM with tilmicosin
for 24 hours and then with tilmicosin-resistant
Salmonella serotype Typhimurium. Bactericidal activity
was evaluated by incubating AM with tilmicosin (0,
10, or 20 µg/ml for bovine AM; 0 or 10 µg/ml or 10
µg/ml but washed free of tilmicosin for porcine AM)
and then with Mannheimia haemolytica (bovine AM)
or with Actinobacillus pleuropneumoniae or
Pasteurella multocida(porcine AM).
Results—Tilmicosin had no significant effects on
chemotactic or phagocytic activities of bovine or
porcine AM. The time-course of bactericidal activity
was best described by polynomial equations. Time to
cessation of bacterial growth and area under the time
versus bacterial number curve were significantly
affected by incubation of AM with tilmicosin.
Conclusion and Clinical Relevance—Results show
that bactericidal activity of bovine and porcine AM
was enhanced by tilmicosin, but not in proportion to
the reported ability of AM to concentrate tilmicosin
intracellularly. With or without exposure to tilmicosin,
the time-course of bactericidal activity of bovine AM
against M haemolytica and of porcine AM against
A pleuropneumoniae or P multocida was too complex
to be reduced to a simple linear equation. (Am J Vet
Objective—To examine the effect of various clinical tracks within the veterinary medical clinical curriculum at Texas A&M University on clinical diagnostic proficiency as determined by pre- and post-training assessment. We expected that the clinical track chosen by the student would impact their measured outcome with bias toward higher scores in their chosen field.
Design—Prospective cohort study.
Study Population—32 students from the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University.
Procedures—By use of standardized, written case scenarios, clinical reasoning was assessed twice: once prior to the clinical (fourth) year of the curriculum and again at completion of the clinical year. Students demonstrated their abilities to collect and organize appropriate clinical data (history, physical examination, and laboratory findings), determine clinical diagnoses, and formulate and implement acceptable treatment modalities. Data from clinical assessments were compared for a given cohort and correlated with other measures (eg, grades, standardized test scores, and species-specific curricular track).
Results—Differences were detected in clinical diagnostic proficiency among students in different clinical tracks and for different species groups in the case scenarios. Tracking by species group in the clinical veterinary curriculum appeared to affect development of clinical reasoning and resulted in differential proficiency among cases for differing species groups.
Conclusions and Clinical Relevance—Differences in clinical experiences between small animal tracks and all other track opportunities (large animal, mixed animal, and alternative) influenced the development of clinical proficiency in fourth-year veterinary students during their clinical training period.