Search Results

Abstract

Objective—To determine significant molecular and cellular factors responsible for differences in secondintention healing in thoracic and metacarpal wounds of horses.

Animals—6 adult mixed-breed horses.

Procedure—A full-thickness skin wound on the metacarpus and another such wound on the pectoral region were created, photographed, and measured, and tissue was harvested from these sites weekly for 4 weeks. Gene expression of type-I collagen, transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-1, and tissue inhibitor of metalloproteinase (TIMP)-1 were determined by quantitative in situ hybridization. Myofibroblasts were detected by immunohistochemical labeling with α-smooth muscle actin (α-SMA). Collagen accumulation was detected by use of picrosirius red staining. Tissue morphology was examined by use of H&E staining.

Results—Unlike thoracic wounds, forelimb wounds enlarged during the first 2 weeks. Myofibroblasts, detected by week 1, remained abundant with superior organization in thoracic wounds. Type-I collagen mRNA accumulated progressively in both wounds. More type-I collagen and TGF-β1 mRNA were seen in forelimb wounds. Volume of MMP-1 mRNA decreased from day 0 in both wounds. By week 3, TIMP-1 mRNA concentration was greater in thoracic wounds.

Conclusions and Clinical Relevance—Greater collagen synthesis in metacarpal than thoracic wounds was documented by increased concentrations of myofibroblasts, type-I collagen mRNA, TGF-β1 mRNA, and decreased collagen degradation (ie, MMP-1). Imbalanced collagen synthesis and degradation likely correlate with development of exuberant granulation tissue, delaying healing in wounds of the distal portions of the limbs. Factors that inhibit collagen synthesis or stimulate collagenase may provide treatment options for horses with exuberant granulation tissue. (Am J Vet Res 2002;63:1564–1570)

Abstract

Objective—To determine incidence of animal bite injuries among humans in North Carolina by use of statewide emergency department visit data; to evaluate incidence rates on the basis of age, sex, urbanicity, biting species, and month for selected species; and to characterize bite-related emergency department visits.

Design—Retrospective cohort and cross-sectional study.

Sample—Records of 38,971 incident animal bite–related emergency department visits in North Carolina from 2008 to 2010.

Procedures—Emergency department visits were selected for inclusion by means of external-cause-of-injury codes assigned with an international coding system and keyword searches of chief complaint and triage notes. Rates were calculated with denominators obtained from census data. Cross-sectional analysis of incident emergency department visits was performed.

Results—By the age of 10, a child in North Carolina had a 1 in 50 risk of dog bite injury requiring an emergency department visit. Incidence rates for dog bites were highest for children ≤ 14 years of age, whereas the incidence rate for cat bites and scratches was highest among individuals > 79 years of age. Lifetime risk of cat bite or scratch injury requiring an emergency department visit was 1 in 60 for the population studied. Rabies postexposure prophylaxis was administered during 1,664 of 38,971 (4.3%) incident visits.

Conclusions and Clinical Relevance—Emergency department visit surveillance data were used to monitor species-specific bite incidence statewide and in various subpopulations. Emergency department surveillance data may be particularly useful to public health veterinarians. Results may inform and renew interest in targeted animal bite prevention efforts.