Objectives—To determine effects of selectin inhibitor
TBC1269 on neutrophil infiltration, and neutrophilassociated
injury during pneumonia induced by
Mannheimia haemolytica and concentration of antimicrobial
anionic peptide (AAP) in bronchoalveolar
lavage fluid (BALF) as well as antimicrobial activity of
BALF from healthy (control) neonatal calves, neonatal
calves with M haemolytica-induced pneumonia,
neonatal calves with prior treatment with TBC1269,
and adult cattle.
Animals—Eighteen 1- to 3-day-old calves and 9 adult
Procedure—Calves were inoculated with M
haemolyticaor pyrogen-free saline (0.14M NaCl) solution
into the right cranial lung lobe, and BALF was collected
2 or 6 hours after inoculation. Thirty minutes
before and 2 hours after inoculation, 4 calves received
TBC1269. The BALF collected from 9 adult cattle was
used for comparison of BALF AAP concentration and
antimicrobial activity. Protein concentration and neutrophil
differential percentage and degeneration in
BALF were determined. An ELISA and killing assay
were used to determine BALF AAP concentration and
antimicrobial activity, respectively.
Results—Total protein concentration was significantly
decreased in BALF from calves receiving TBC1269.
Similar concentrations of AAP were detected in BALF
from all calves, which were 3-fold higher than those in
BALF from adult cattle. However, BALF from
neonates had little or no anti-M haemolytica activity.
Conclusions and Clinical Relevance—These results
suggest that TBC1269 decreases pulmonary tissue
injury in neonatal calves infected with M haemolytica.
Although AAP is detectable in neonatal BALF at 3
times the concentration detected in adult BALF,
neonatal BALF lacks antimicrobial activity for M
haemolytica. (Am J Vet Res 2001;62:665–672)
Objective—To determine effects of the selectin
inhibitor TBC1269 on neutrophil-mediated pulmonary
damage during acute Mannheimia haemolytica-induced pneumonia
in newborn calves.
Animals—Eighteen 1- to 3-day-old colostrumdeprived
Procedure—Mannheimia haemolytica or saline
(0.9% NaCl) solution was inoculated in both cranial
lung lobes of 12 and 6 calves, respectively. Calves
were euthanatized 2 (saline, n = 3; M haemolytica,
n = 4) or 6 hours (saline, n = 3; M haemolytica, n = 8)
after inoculation. Four M haemolytica-inoculated
calves euthanatized at 6 hours also received TBC1269
(25 mg/kg, IV) 30 minutes before and 2 hours after
inoculation. Conjugated diene (CD) concentrations,
inducible nitric oxide synthase (iNOS) expression, and
apoptotic cell counts were determined in lung specimens
collected during necropsy.
Results—Conjugated diene concentrations were significantly
increased in all M haemolytica-inoculated groups,
compared with saline-inoculated groups. Calves treated
with TBC1269 had decreased concentrations of CD,
compared with untreated calves, although the difference
was not significant. Number of apoptotic neutrophils and
macrophages increased significantly in TBC1269-treated
calves, compared with untreated calves. Inducible nitric
oxide synthase was expressed by epithelial cells and
leukocytes. However, iNOS was less abundant in airway
epithelial cells associated with inflammatory exudates.
Degree of iNOS expression was similar between
TBC1269-treated and untreated calves.
Conclusions—Mannheimia haemolytica infection in
neonatal calves resulted in pulmonary tissue damage
and decreased epithelial cell iNOS expression. The
selectin inhibitor TCB1269 altered, but did not completely
inhibit, neutrophil-mediated pulmonary damage.
( Am J Vet Res 2001;62:17–22)
Objective—To measure serum calprotectin concentration in dogs with inflammatory bowel disease (IBD) before and after initiation of treatment and evaluate its correlation with a clinical scoring system (canine IBD activity index), serum canine C-reactive protein concentration, and severity of histopathologic changes.
Animals—34 dogs with idiopathic IBD and 139 healthy control dogs.
Procedures—From dogs with IBD, blood samples were collected immediately before (baseline) and 3 weeks after initiation of 1 of 2 treatments: prednisone (1 mg/kg, PO, q 12 h; n = 21) or a combination of prednisone and metronidazole (10 mg/kg, PO, q 12 h; 13). Blood samples were collected once from each of the control dogs. For all samples, serum calprotectin concentration was determined via radioimmunoassay.
Results—Mean serum calprotectin concentrations for dogs with IBD at baseline (431.1 μg/L) and 3 weeks after initiation of treatment (676.9 μg/L) were significantly higher, compared with that (219.4 μg/L) for control dogs, and were not significantly correlated with the canine IBD activity index, serum C-reactive protein concentration, or severity of histopathologic changes. The use of a serum calprotectin concentration of ≥ 296.0 μg/L as a cutoff had a sensitivity of 82.4% (95% confidence interval, 65.5% to 93.2%) and specificity of 68.4% (95% confidence interval, 59.9% to 76.0%) for distinguishing dogs with idiopathic IBD from healthy dogs.
Conclusions and Clinical Relevance—Serum calprotectin concentration may be a useful biomarker for the detection of inflammation in dogs, but the use of certain drugs (eg, glucocorticoids) appears to limit its clinical usefulness.
Objective—To characterize mucosal gene expression in dogs with chronic enteropathy (CE).
Animals—18 dogs with CE and 6 healthy control dogs.
Procedures—Small intestinal mucosal biopsy specimens were endoscopically obtained from dogs. Disease severity in dogs with CE was determined via inflammatory bowel index scores and histologic grading of biopsy specimens. Total RNA was extracted from biopsy specimens and microchip array analysis (approx 43,000 probe sets) and quantitative reverse transcriptase PCR assays were performed.
Results—1,875 genes were differentially expressed between dogs with CE and healthy control dogs; 1,582 (85%) genes were downregulated in dogs with CE, including neurotensin, fatty acid–binding protein 6, fatty acid synthase, aldehyde dehydrogenase 1 family member B1, metallothionein, and claudin 8, whereas few genes were upregulated in dogs with CE, including genes encoding products involved in extracellular matrix degradation (matrix metallopeptidases 1, 3, and 13), inflammation (tumor necrosis factor, interleukin-8, peroxisome proliferator–activated receptor γ, and S100 calcium-binding protein G), iron transport (solute carrier family 40 member 1), and immunity (CD96 and carcinoembryonic antigen–related cell adhesion molecule [CEACAM] 18). Dogs with CE and protein-losing enteropathy had the greatest number of differentially expressed genes. Results of quantitative reverse transcriptase PCR assay for select genes were similar to those for microchip array analysis.
Conclusions and Clinical Relevance—Expression of genes encoding products regulating mucosal inflammation was altered in dogs with CE and varied with disease severity.
Impact for Human Medicine—Molecular pathogenesis of CE in dogs may be similar to that in humans with inflammatory bowel disease.