Objective—To quantify peripheral blood neutrophil apoptosis in equine patients with acute abdominal disease (ie, colic) caused by strangulating or nonstrangulating intestinal lesions and compare these values with values for horses undergoing elective arthroscopic surgery.
Animals—20 client-owned adult horses.
Procedures—Peripheral blood was collected from horses immediately prior to and 24 hours after surgery for treatment of colic (n = 10) or elective arthroscopic surgery (10), and neutrophils were counted. Following isolation by means of a bilayer colloidal silica particle gradient and culture for 24 hours, the proportion of neutrophils in apoptosis was detected by flow cytometric evaluation of cells stained with annexin V and 7-aminoactinomycin D. Values were compared between the colic and arthroscopy groups; among horses with colic, values were further compared between horses with and without strangulating intestinal lesions.
Results—Percentage recovery of neutrophils was significantly smaller in preoperative samples (median, 32.5%) and in all samples combined (35.5%) for the colic group, compared with the arthroscopy group (median, 66.5% and 58.0%, respectively). No significant differences in the percentages of apoptotic neutrophils were detected between these groups. Among horses with colic, those with strangulating intestinal lesions had a significantly lower proportion of circulating apoptotic neutrophils in postoperative samples (median, 18.0%) than did those with nonstrangulating lesions (66.3%).
Conclusions and Clinical Relevance—The smaller proportion of apoptotic neutrophils in horses with intestinal strangulation suggested that the inflammatory response could be greater or prolonged, compared with that of horses with nonstrangulating intestinal lesions. Further investigations are needed to better understand the relationship between neutrophil apoptosis and inflammation during intestinal injury.
Objective—To compare expression of tartrate-resistant
acid phosphatase (TRAP) and cathepsin K and
histologic changes in canine cranial cruciate ligaments
(CCLs) and human anterior cruciate ligaments (ACLs).
Study Population—Sections of cruciate ligaments
from 15 dogs with ruptured CCLs, 8 aged dogs with
intact CCLs, 14 human beings with ruptured ACLs,
and 11 aged human beings with intact ACLs.
Procedure—The CCLs and ACLs were evaluated histologically,
and cells containing TRAP and cathepsin K
were identified histochemically and immunohistochemically,
Results—The proportion of ruptured CCLs that contained
TRAP+ cells was significantly higher than the
proportion of intact ACLs that did but similar to proportions
of intact CCLs and ruptured ACLs that did.
The proportion of ruptured CCLs that contained
cathepsin K+ cells was significantly increased, compared
with all other groups. Numbers of TRAP+ and
cathepsin K+ cells were significantly increased in ruptured
CCLs, compared with intact ACLs. The presence
of TRAP+ cells was correlated with inflammatory
changes, which were most prominent in ruptured
Conclusion and Clinical Relevance—Results suggest
that synovial macrophage-like cells that produce
TRAP are an important feature of the inflammation
associated with CCL rupture in dogs. Identification of
TRAP and cathepsin K in intact CCLs and ACLs from
aged dogs suggests that these enzymes have a functional
role in cruciate ligament remodeling and repair.
We hypothesize that recruitment and activation of
TRAP+ macrophage-like cells into the stifle joint synovium
and CCL epiligament are critical features of the
inflammatory arthritis that promotes progressive
degradation and eventual rupture of the CCL in dogs.
(Am J Vet Res 2005;66:2073–2080)
Objective—To compare viability and biosynthetic capacities of cells isolated from equine tendon, muscle, and bone marrow grown on autogenous tendon matrix.
Sample Population—Cells from 4 young adult horses.
Procedures—Cells were isolated, expanded, and cultured on autogenous cell-free tendon matrix for 7 days. Samples were analyzed for cell viability, proteoglycan synthesis, collagen synthesis, and mRNA expression of collagen type I, collagen type III, and cartilage oligomeric matrix protein (COMP).
Results—Tendon- and muscle-derived cells required less time to reach confluence (approx 2 weeks) than did bone marrow–derived cells (approx 3 to 4 weeks); there were fewer bone marrow–derived cells at confluence than the other 2 cell types. More tendon- and muscle-derived cells were attached to matrices after 7 days than were bone marrow–derived cells. Collagen and proteoglycan synthesis by tendon- and muscle-derived cells was significantly greater than synthesis by bone marrow–derived cells. On a per-cell basis, tendon-derived cells had more collagen synthesis, although this was not significant. Collagen type I mRNA expression was similar among groups. Tendon-derived cells expressed the highest amounts of collagen type III and COMP mRNAs, although the difference for COMP was not significant.
Conclusions and Clinical Relevance—Tendon- and muscle-derived cells yielded greater cell culture numbers in shorter time and, on a per-cell basis, had comparable biosynthetic assays to bone marrow–derived cells. More in vitro experiments with higher numbers may determine whether tendon-derived cells are a useful resource for tendon healing.