Biochemical analysis of the articular cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis

OBJECTIVE: To assess whether site-related changes in biochemical composition are present in the cartilage and subchondral and trabecular bone of the metacarpophalangeal joint of horses with early osteoarthritis. SAMPLE POPULATION: Right metacarpophalangeal joints from 59 mature warmblood horses. PROCEDURE: Biochemical data (cross-link, amino acid, DNA, and ash contents; denatured collagen and glycosaminoglycan [GAG] concentrations; bone mineral density; and mineral composition) were obtained from 2 differently loaded sites of phalanx I cartilage and subchondral and trabecular bone samples; data were compared with previously published values from nonosteoarthritic equine joints. RESULTS: Compared with findings in nonosteoarthritic joints, GAG concentration was lower in cartilage from osteoarthritic joints and there was a loss of site differences in cellularity and lysylpyridinoline (LP) cross-link content. In subchondral bone, LP cross-link content was decreased overall and there was a loss of site differences in osteoarthritic joints; ash content was higher in the osteoarthritic joints. Hydroxyproline content in trabecular bone from osteoarthritic joints was greater than that in nonosteoarthritic trabecular bone. In all 3 layers and at both sites, the linear increase of the pentosidine cross-link content with age had diminished or was not apparent in the horses with osteoarthritic joints. CONCLUSIONS AND CLINICAL RELEVANCE: In equine metacarpophalangeal joints with early osteoarthritis, distinct biochemical changes were detected in the cartilage and subchondral and trabecular bone. The dissimilarity in response of the different tissues and differences between the sites that are affected may be related to differences in biomechanical loading and transmission and dissipation of force.     

Accuracy and optimization of force platform gait analysis in Labradors with cranial cruciate disease evaluated at a walking gait

OBJECTIVE: To determine the combination of ground reaction forces (GRFs) that best discriminates between lame and non-lame dogs. To compare the sensitivity of force platform gait analysis and visual observation at detecting gait abnormalities in Labradors after surgery for rupture of the cranial cruciate ligament (CCL). ANIMALS: All dogs were adult Labrador Retrievers: 17 free of orthopedic and neurologic abnormalities, 100 with unilateral CCL rupture, and 131 studied 6 months after surgery for unilateral CCL injury, 15 with observable lameness. PROCEDURE: Dogs were walked over a force platform with GRF recorded during the stance phase. Analytic properties of force platform gait analysis were calculated for several combinations of forces. The probability of visual observation detecting a gait abnormality was compared with that of force platform gait analysis. RESULTS: We determined that a combination of peak vertical force (PVF) and falling slope were optimal for discriminating sound and lame Labradors. After surgery, many dogs (75%) with no observable lameness failed to achieve GRFs consistent with sound Labradors. CONCLUSION: A force platform is an accurate method of assessing lameness in Labradors with CCL rupture and is more sensitive than visual observation. Assessing lameness with a combination of GRFs is better than using univariate GRFs. CLINICAL RELEVANCE: Therapies for stifle lameness can be accurately and objectively evaluated using 2 vertical ground reaction forces obtained from a force platform.     

Canine sacroiliac luxation: anatomic study of dorsoventral articular surface angulation and safe corridor for placement of screws used for lag fixation

OBJECTIVE: To define a safe corridor in the dorsoventral plane to facilitate placement of screws inserted in lag fashion within the sacral body for fixation of sacroiliac fracture-luxation injuries in dogs. STUDY DESIGN: Anatomic study. SAMPLE POPULATION: Cadaveric canine sacra. METHODS: Canine sacra (n=45) were used for a radiographic study to define a safe corridor in the dorsoventral plane for placement of screws inserted in lag fashion for fixation of sacroiliac luxation in the dog. The defined safe corridor allowed drilling to a depth of 65% of the sacral width to ensure screw purchase of > or =60%. Effects of positioning and measurement techniques were evaluated. RESULTS: Eighty-seven safe corridors were measured. The mean articular surface was 100+/-4.52 degrees from horizontal. Mean maximum, optimum, and minimum safe corridor drill angles were 111+/- 4.57 degrees, 100+/-4.70 degrees, and 89+/-5.17 degrees, respectively, from the articular surface. Predicted surgeon error of +/-4 degrees was used to define the safe corridor for use clinically. CONCLUSIONS: In 91% of sacra, a drill angle of 100+/-4 degrees would remain ventral to the vertebral canal. Twelve sacra (14%) were at risk of penetration of the pelvic canal. A drill angle of 97+/-4 degrees avoids penetration of the vertebral canal in all sacra measured but risks ventral exit from the body in 30% of sacra studied. CLINICAL RELEVANCE: A drill angle of 97 degrees from the articular surface is recommended for insertion of screws for lag fixation of canine sacroiliac luxation.     

The epidemiology and diagnosis of bluetongue with particular reference to Corsica

Bluetongue (BT) and/or BT viruses (BTV) have been identified in the Mediterranean basin and the Balkans each year from 1998 to 2002 and in particular BTV serotype 2 in the French Island of Corsica (2000 and 2001). In response to these virus incursions, the French Veterinary Authorities carried out epidemiological studies that included virological, serological and entomological analysis, and two vaccination campaigns performed in the winter of 2000/2001 and the winter and spring of 2001 and 2002. Rapid and reliable serotype differentiation is essential at the start of an outbreak to allow an early selection of vaccine to control the spread of the virus. Thus, molecular tools, that complement conventional methods, have been developed for early detection of infection, determination of the serotype, and differentiation between natural infection and vaccination. Serological results showed that the first vaccination campaign during the winter of 2000/2001 did not provide full protection for all sheep and during the summer of 2001, 335 sheep flocks in Corsica were again infected by BTV 2 (7-fold more that in 2000). Entomological studies have demonstrated that the only proven vector of the disease, Culicoides imicola, was present in the island in 2000 and that it has successfully established itself in Corsica. The safety and immunogenicity of the commercial South African vaccine were studied. Fourteen sheep were vaccinated and then observed for clinical signs. Blood, sera, spleen and lymph nodes were collected and analyzed, and the results confirmed the safety and potency of using this vaccine to protect sheep from clinical disease. As a result, an intensive vaccination campaign was performed during winter and spring 2001/2002. No cases of BT had been observed by the end of summer 2002, indicating that the vaccination campaign has been successful in protecting sheep from infection.     

Delivery of growth factors using gene therapy to enhance bone healing

OBJECTIVE: To review the delivery of growth factors using gene therapy for enhancing long-bone fracture healing. STUDY DESIGN: Literature review. METHODS: MEDLINE and CAB Abstracts literature search (1980-2004). RESULTS: Non-union and infected non-union are relatively common complications of long-bone fractures in human and veterinary patients. Growth factors are cytokines that regulate many cell functions important in fracture healing. Exogenous growth factors can be delivered to the fracture site as recombinant proteins or using gene therapy. Recombinant human bone morphogenetic protein-2 and -7 (rhBMP-2 and -7), in particular, enhance fracture healing in numerous experimental and clinical studies. Some limitations with use of recombinant proteins may be overcome by use of gene therapy. Gene therapy involves delivery of the growth factor gene to cells at the fracture site using a viral or non-viral vector. The gene is then expressed (protein synthesis) by cells at the fracture site. Delivery of the BMP gene to the fracture site using gene therapy has been evaluated in laboratory animal models of non-union, with favorable results and without complications. CONCLUSION: Delivery of growth factors, particularly members of BMP family, to the fracture site using gene therapy may be a method to enhance fracture healing. Use of this technology may improve the prognosis for patients with long-bone fractures. CLINICAL RELEVANCE: Clinical application of gene therapy could improve the prognosis for human and veterinary patients with long-bone fractures, but has not been evaluated clinically.     

Exhaled breath condensate (EBC) collection in cats--description of a non-invasive technique to investigate airway disease

Exhaled breath condensate has been collected in other species and used as a non-invasive method of evaluating airway disease by measurement of various markers in the fluid, including hydrogen peroxide, nitric oxide, leukotrienes and prostaglandins. We describe a novel technique for the collection of exhaled breath condensate from cats, which enabled collection of fluid and measurement of its hydrogen peroxide concentration. Further studies will be needed to establish the value of this technique in the investigation of feline respiratory disease.     

Tumor necrosis factor-alpha enhances Haemophilus somnus lipooligosaccharide-induced apoptosis of bovine endothelial cells

Haemophilus somnus lipooligosaccharide (LOS)-induced apoptosis of bovine pulmonary artery endothelial cells has been shown previously to be dependent on capsase-8 activation. Activation of caspase-8 can occur via a death receptor-dependent mechanism (e.g., TNF- binding to TNF- receptor 1 (TNF-R1)). In this study, we tested the hypothesis that TNF- can enhance LOS-induced apoptosis of bovine endothelial cells. Addition of exogenous recombinant human TNF- alone failed to cause apoptosis, or enhance LOS-induced apoptosis, of bovine endothelial cells. However, blocking de novo protein synthesis by addition of cycloheximide significantly enhanced apoptosis of bovine endothelial cells by TNF-, LOS or TNF- and LOS in combination. Conversely, addition of soluble recombinant human (sTNF-R1) diminished LOS-induced apoptosis. Overall, these data suggest that LOS-mediated apoptosis may be due, in part, to activation of a TNR-R1-dependent death pathway.     

Anticonvulsant activity and tolerance of ELB138 in dogs with epilepsy: a clinical pilot study

A new antiepileptic and anxiolytic drug, ELB138, was evaluated in a clinical pilot study in dogs with newly diagnosed or chronic idiopathic epilepsy. The purpose was to verify clinically the anticonvulsant effectiveness of this substance, which had already been demonstrated experimentally. Data from 29 dogs treated with ELB138 were compared with results obtained retrospectively from 82 dogs treated with conventional antiepileptic medication. The reduction in seizure frequency using ELB138 in dogs with newly diagnosed idiopathic epilepsy was comparable to the reduction in dogs treated either with phenobarbital or primidone. In dogs with chronic epilepsy and add-on therapy with either ELB138 or potassium bromide, such supplementation reduced the seizure frequency and the duration and severity of seizures. The most obvious difference between ELB138 treatment and conventional medications became clear in the evaluation of side effects, which in those dogs treated with ELB138 were rare, and consisted mostly of transient polyphagia. This pilot study confirmed that ELB138 has a potent anticonvulsant effect in dogs with idiopathic epilepsy. These results will form the basis for a multicentre, blinded study.