Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Rafael R. Faleiros x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract

Objective—To determine the effect of experimental intraluminal distention on microvascular perfusion of the small colon in horses.

Animals—6 mixed-breed healthy horses (mean age [± SD], 9.1 ± 2 years).

Procedure—Under general anesthesia, the small colon was exposed by celiotomy and 3 segments were demarcated. In 1 of these segments, intraluminal obstruction was created by placement of a latex balloon inflated to a pressure of 40 mm Hg (obstructed segment). The other segments were the sham-operated segment and the control segment. Microvascular perfusion was evaluated in the mucosal, submucosal, muscular, and serosal layers by injection of 15-µm-diameter colored microspheres into branches of the caudal mesenteric artery. Recovery of microspheres was performed by tissue digestion, washing, and centrifugation. Distribution of microspheres in the intestinal layers was evaluated by direct observation of stained frozen sections by light microscopy.

Results—A significant reduction was observed in total microvascular perfusion of obstructed segments, which was 26.4% of that of control segments. This reduction was not evident in the mucosal layer.

Conclusion and Clinical Relevance—Intraluminal distention of the equine small colon wall can promote ischemia by a reduction in microvascular perfusion in the intestinal wall. Intestinal layers do not seem to be affected to the same extent, because the absolute value for mucosal perfusion did not decrease in the obstructed segment. (Am J Vet Res 2002;63:1292–1297)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine and compare the number, type, location, and distribution of apoptotic epidermal cells in the laminae of clinically normal horses and horses with laminitis.

Sample Population—Formalin-fixed samples of digital lamellar tissue from 47 horses (including clinically normal horses [controls; n = 7], horses with acute [4] and chronic [7] naturally acquired laminitis, and horses with black walnut extract-induced [11] or carbohydrate overload-induced [18] laminitis).

Procedure—Blocks of paraffin-embedded lamellar tissues were stained for DNA fragmentation with the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. Differential immunohistochemical staining for caspases 3 and 14 were used to confirm apoptosis.

Results—The number of TUNEL-positive epidermal cells per 0.1 mm of primary laminae was significantly greater in the acute laminitis group than in the other groups. In the acute laminitis group, there were 17 and 1,025 times as many TUNEL-positive basal layer cells and keratinocytes, respectively, compared with the control group. Apoptosis of TUNEL-positive basal layer cells was confirmed by results of caspase 3 immunohistochemical staining. The TUNEL-positive keratinocytes did not stain for caspases 3 or 14.

Conclusions and Clinical Relevance—The large number of apoptotic basal layer cells detected in the lamellar tissue of horses with acute naturally acquired laminitis suggests that apoptosis may be important in the development of acute laminitis. The role of the large number of TUNEL-positive keratinocytes detected in the interface of primary and secondary epidermal laminae of horses with acute laminitis remains to be elucidated. ( Am J Vet Res 2004;65:578–585)

Full access
in American Journal of Veterinary Research