Molecular and histologic evaluation of idiopathic hyperextension of the metacarpophalangeal and metatarsophalangeal joints in adult llamas

Abstract Objective—To determine the molecular and histologic characteristics of hyperextension of the metacarpophalangeal and metatarsophalangeal joints in adult llamas. Animals—12 adult llamas (6 with bilateral hyperextension of the metacarpophalangeal or metatarsophalangeal joints [affected] and 6 age- and sex-matched clinically normal control llamas). Procedures—Llamas were euthanized, and specimens of superficial digital flexor tendon, deep digital flexor tendon, and suspensory ligament were obtained from 4 areas and snap frozen in liquid nitrogen or suspended in neutral-buffered 10% formalin. Histologic evaluation of collagen fiber orientation, elastin content, and proteoglycan content was performed by use of Masson trichrome, picrosirius red, Verhoeff, and Alcian blue stains. Total RNA was isolated from frozen suspensory ligament specimens. Gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 was evaluated with a real-time quantitative reverse transcriptase PCR assay. Results—Gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 in suspensory ligaments was similar between affected and control llamas. Collagen orientation and elastin content of the flexor tendons and suspensory ligaments were also similar between the groups. Proteoglycan content was low in most specimens but was focally increased in discrete lesions of suspensory ligaments in 2 affected and 2 control llamas. Conclusions and Clinical Relevance—Hyperextension of the metacarpophalangeal or metatarsophalangeal joints in llamas did not appear to be caused by degeneration or inflammation of the suspensory ligament. Although focal proteoglycan accumulation existed in the suspensory ligaments of 2 affected llamas, widespread abnormal connective tissue proteoglycan accumulation was not found.</jats:p

Molecular, histologic, and trace mineral characterization of metacarpophalangeal and metatarsophalangeal joint hyperextension in juvenile llamas

Abstract Objective—To evaluate molecular and histologic characteristics of the superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), and suspensory ligament (SL) and assess trace-mineral concentrations in serum, liver, and hair of juvenile llamas with metacarpophalangeal and metatarsophalangeal joint hyperextension. Animals—12 juvenile llamas (6 with bilateral hyperextension of metacarpophalangeal joints, metatarsophalangeal joints, or both and 6 clinically normal control llamas). Procedures—Radiography and ultrasonography of metacarpophalangeal and metatarsophalangeal regions were performed. Llamas were euthanized, and SDFT, DDFT, and SL samples were collected for histologic evaluation of collagen and elastin content and orientation, proteoglycan content, and collagen type III immunohistochemistry. Total RNA was isolated from SL tissue, and gene expression of collagen types I and III, lysyl oxidase, and matrix metalloproteinase-13 was evaluated via real-time quantitative reverse transcriptase PCR assay. Liver, serum, and hair samples were evaluated for trace mineral content. Results—Collagen type III gene expression and proteoglycan content were significantly increased in SL samples of affected juvenile llamas, compared with those of control llamas. No difference was detected in collagen and elastin content and orientation or in gene expression of collagen type I, lysyl oxidase, or matrix metalloproteinase-13 between groups. Affected llamas had significantly increased serum molybdenum and decreased liver cobalt concentrations, compared with values for control llamas. Conclusions and Clinical Relevance—Increased collagen type III gene expression and proteoglycan content in SL samples of affected juvenile llamas provided evidence of ongoing SL matrix repair. Trace mineral differences may have been attributable to dietary imbalances in affected llamas.</jats:p

Septic flexor tendonitis and suspensory desmitis in an alpaca

Abstract Case Description—A 2-year-old male Suri alpaca was referred for evaluation of severe right forelimb lameness of 2 weeks' duration following a traumatic episode. Clinical Findings—Examination of the distal aspect of the metacarpus revealed 4 wounds exuding purulent material. On weight bearing, the metacarpophalangeal joint was severely hyperextended with the palmar surface touching the ground. Ultrasonography of the palmar surface of the metacarpus revealed desmitis of the proximal suspensory ligament, a large core lesion of the deep digital flexor tendon at mid-metacarpus, and complete loss of fiber pattern within the deep digital flexor tendon and lateral aspect of the superficial digital flexor tendon distally. Treatment and Outcome—The alpaca was treated systemically with antimicrobials and anti-inflammatory drugs and underwent repeated antimicrobial intraosseous regional limb perfusion. A bandage and splint were applied to stabilize the affected forelimb in an anatomically correct position, and the alpaca underwent prolonged stall confinement. At the time of hospital discharge 5 days after initial evaluation, clinical evidence of infection at the wound sites was absent. Three months following treatment, the alpaca was moving freely in a small paddock and had moderate hyperextension of the metacarpophalangeal joint. Clinical Relevance—Treatment of septic flexor tendonitis and suspensory desmitis with antimicrobial intraosseous regional limb perfusion in combination with systemic treatment with antimicrobials and orthopedic support resulted in an excellent outcome in this alpaca. Antimicrobial intraosseous regional limb perfusion is simple to perform and has the potential to be beneficial in the treatment of infections in the distal portion of a limb in camelids.</jats:p

Gene expression profiling from leukocytes of horses affected by osteochondrosis.

Osteochondrosis (OC) is a developmental disease that affects growing horses and that severely affects their ability to perform. The genetic basis of its pathogenesis is poorly understood. The aim of the study was to analyze the transcript profile of leukocytes from horses affected with OC. Two transcriptome libraries were constructed from leukocytes of OC-affected and non-OC-affected horses using digital gene expression analysis (DGE) and real-time PCR. Statistical analysis allowed selection of 1,008 tags upregulated in the non-OC-affected group and 1,545 tags upregulated in the OC-affected group. Among these genes, 16 regulated genes and 5 housekeeping genes were selected. Metabolic pathways analysis showed an obvious dysregulation of several signaling pathways related to cartilage formation or cartilage repair, including Wnt, Indian hedgehog, and TGF-beta signaling. Other genes, including ISG, ApoB, MGAT4, and TBC1D9, showed a significantly different expression between groups. These genes may play a role in high carbohydrate diet, abnormal insulin metabolism, or inflammation, mechanisms suspected to be involved in OC. This DGE analysis of the transcript profile of leukocytes from OC-affected horses demonstrated significant differences in comparison to the control library. These results open new perspectives for the understanding of equine OC. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res