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Abstract

Objective

To evaluate the ability of hyaluronic acid (HA), with and without transforming growth factor β (TGF-β), to stabilize the catabolic processes associated with atrophy of articular cartilage.

Animals

20 adult, skeletally normal, hound-type dogs.

Procedure

Dogs (20 to 30 kg) were randomly assigned to 1 of 5 groups. One group served as untreated controls. Bivalve casts were placed on the left hind limbs of the remaining 16 dogs to limit weightbearing and motion of the limb for 92 days. One group served as the cast control. Beginning on day 56, 3 groups received aseptic intra-articular injections in the left stifles of either 5 mg of HA or 5 mg of HA containing either 20 or 50 μg of TGF-β. Intra-articular injections were repeated at 4-day intervals until the end of the study. On day 92, stifles were harvested at necropsy. Medial femoral condyles were histologically processed, and the articular cartilage was stained for the presence of proteoglycans, stromelysin, tumor necrosis factor (TNF) α, and TNF receptors (p55 and p75).

Results

Decreased metachromasia was evident in the cartilage matrix of all cast groups, with the smallest decrease in the HA-treated group. Stromelysin was immunolocalized in articular cartilage of the cast (left) limbs of cast control and both HA/TGF-β-treated groups. TNF-α was localized in articular cartilage of all cast (left) and right limbs, except those of the HA-treated group. Receptors for TNF were observed in both limbs of untreated control and cast control groups and cast limbs of HA/TGF-β-treated groups. The receptors were not localized in the right limbs of the HA with or without TGF-β-treated groups. TGF-β did not decrease stromelysin or TNF-α or receptors at the doses used.

Conclusions

HA may mediate a chondrostabilizing influence on articular cartilage by down-regulating TNF-α. Importantly, HA appeared to exert its inhibitory influence on TNF-α, as well as stromelysin and TNF receptors, on a systemic basis.

Clinical Relevance

Results provide insight into the mode of action of HA as a therapeutic agent for arthritis and its stabilizing influence on cartilage metabolism. (Am J Vet Res 1996;57:1488-1496)

Free access
in American Journal of Veterinary Research

Objective—

To compare a prescrotal castration technique with the conventional bilateral scrotal incision technique for castration of llamas.

Design—

Prospective randomized controlled trial.

Animals—

10 clinically normal, sexually intact male llamas.

Procedure—

Five llamas were castrated by use of a 5-cm skin incision located 2 to 3 cm lateral to the ventral midline and approximately 15 cm cranial to the scrotum, which was closed with absorbable suture material to allow primary healing. Five other llamas were castrated via a more conventional technique, with a 5-cm scrotal incision positioned directly over each testis, which was allowed to heal by second intention.

Results—

The prescrotal technique required significantly more time to complete; however, no additional anesthesia was required to complete the longer procedure. Llamas castrated with the prescrotal technique required less aftercare and had less incisional pain when the area was palpated.

Clinical Implications—

Both techniques are safe and effective. Some clients, however, find the prescrotal technique more aesthetically acceptable. The prescrotal technique may be more clinically important where fly control is difficult. U Am Vet Med Assoc 1996:208:261-262)

Free access
in Journal of the American Veterinary Medical Association

Objective

To describe 3 laparoscopic approaches for, and the normal laparoscopic anatomy of, the abdomen in adult llamas and to evaluate the effects of laparoscopy in those llamas.

Design

Prospective clinical trial.

Animals

Six adult castrated male llamas.

Procedure

After induction of general anesthesia, 3 surgical approaches to the abdomen were performed: left paralumbar, ventral midline, and right paralumbar. The abdomen was systematically examined, and anatomic features described. After recovery from anesthesia, all llamas were examined daily for 10 days and CBC was repeated 24, 72, and 120 hours after laparoscopy.

Results

Laparoscopy was successfully performed in all llamas by use of the ventral midline and right paralumbar approaches. The laparoscope was inadvertently placed into the left retroperitoneal space in 1 of the 6 llamas when the left paralumbar approach was used. Also, hemorrhage into the abdomen limited the view from the left side in another llama. Various approaches allowed viewing of the first and third forestomach compartments, liver, spleen, kidneys, small intestine, ileum, proximal loop of the ascending colon, spiral colon, and urinary bladder. Postoperative findings included subcutaneous emphysema and edema. Mean WBC count peaked 24 hours after surgery (mean, 23,500 cells/μl). Generally, neutrophil count increased and lymphocyte count decreased during the 120 hours after surgery.

Clinical Implications

Laparoscopy may be used for differentiation of medical and surgical lesions in the abdomen of llamas. The site for laparoscopy should be chosen on the basis of the most likely site of the suspected lesion.

Free access
in Journal of the American Veterinary Medical Association

Summary:

Case records of cattle admitted to 2 university veterinary hospitals during 6 years were evaluated to determine the age, breed, sex, and treatment of cattle with upward fixation of the patella. Affected cattle were compared with those from the respective hospital populations of cattle admitted during the same time.

Of 38 cattle with upward fixation of the patella, 34 were treated surgically. Follow-up evaluation was obtained from owners of 28 of the treated cattle. Surgery was successful in eliminating all clinical signs in 25 of the 28 cattle. There was an increased risk of upward fixation of the patella associated with Brahman and Brahman-type cattle, compared with non-Brahman cattle.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objectives

To use lipopolysaccharide (LPS) to create synovitis in the midcarpal joint of ponies, and to assess the morphologic, histochemical, and immunohistochemical effects of synovitis on articular cartilage of the third carpal bone.

Animals

2- to 3-year-old ponies, 6 control (group 1) and 6 treated (group 2).

Procedure

Synovitis was induced in 1 midcarpal joint of group-2 ponies by intra-articular injections of LPS (0.02 μg/kg of body weight), morphine (0.1 mg/kg), and saline solution (group 2a) and morphine and saline solution alone in the contralateral midcarpal joint (group 2b). Articular cartilage sections and attached synovial membrane from the third carpal bones were examined by immunohistochemical distribution of interleukin 1β, tumor necrosis factor (TNF)-α, TNF receptors (P55, P75) and 3-B-3(–) epitopes, and by localization of proteoglycans (metachromatic staining). Proteoglycan extracts were assessed by metachromatic staining or western blotting and immunohistochemical staining, using anti-3-B-3 antibodies.

Results

Enhanced immunoreactivity for the cytokines and receptors was found in inflamed synovial membrane and noncalcified cartilage (group 2a more than 2b). Metachromasia of the noncalcified cartilage was greater in group-1 than in group-2a and group-2b specimens. In group 2a, chondrocyte hypertrophy and enhanced immunoreactivity for 3-B-3(–) epitope in areas of increased cytokine immunoreactivity suggested possible phenotypic change of the chondrocytes in response to synovitis. Immunohistochemical analysis by western blotting of proteoglycan extracts indicated strong 3-B-3(–) epitope immunolocalization in group-2a, weaker staining in group-2b, and barely detectable stain in group-1 specimens, which correlated with in situ immunolocalization.

Conclusions

Intra-articular administration of LPS may be used to induce a synovial environment conducive to increased immunoreactivity of interleukin 1β, TNF-α, and its receptors in equine synovial membrane and articular cartilage. These cytokines may be involved in the early phenotypic change of chondrocytes that is believed to occur in osteoarthritis and is characterized in this study by enhanced 3-B-3(–) epitope immunoreactivity and chondrocyte hypertrophy. (Am J Vet Res 1996;57:1080–1093)

Free access
in American Journal of Veterinary Research