Spinal arthritis in invasive cane toads is linked to rate of dispersal as well as to latitude.

Initial research on the spread of cane toads (Rhinella marina) through tropical Australia reported a high incidence of spinal arthritis (spondylosis) in toads at the invasion front (where toads disperse rapidly), but not in areas colonized earlier (where toads are more sedentary). The idea that spondylosis was a cost of rapid dispersal was challenged by wider spatial sampling which linked rates of spondylosis to hot (tropical) climates rather than to dispersal rates. Here, the authors of these competing interpretations collaborate to reinterpret the data. Our reanalysis supports both previous hypotheses; rates of spondylosis are higher in populations established by fast-dispersing toads, and are higher in tropical than in temperate environments; they are also higher in larger toads. The functional reason for climatic effects is unclear, but might involve effects on the soil-living bacteria involved in the induction of spondylosis; and/or may reflect higher movement (as opposed to dispersal) or more pronounced dry-season aggregation rates of toads in tropical conditions.

La interleucina-17 en los modelos animales de espondiloartritis / Interleukin-17 in animal models of spondyloarthritis

La relevancia de la IL-17 en la patogenia de las espondiloartritis ha sido definitivamente contrastada por el éxito terapéutico de sus antagonistas. Los modelos animales han proporcionado información útil sobre las vías moleculares y celulares que implican esta vía en estas enfermedades. Los ratones deficientes en diferentes componentes moleculares relacionados con esta vía pusieron de manifiesto inicialmente la dependencia de numerosas enfermedades inflamatorias de las células Th17 y de las citocinas IL-17 e IL-23 modificando el modelo previo Th1/Th2. Los modelos animales de artritis, colitis y encefalitis autoinmunes han sido útiles para demostrar su dependencia de las células Th17. En otros modelos de artritis, como la inducida por proteoglicanos o por anticuerpos (glucosa-6-fosfato isomerasa), ni las células Th17 ni la IL-17 parecen estar involucradas. Los modelos animales de espondiloartritis y de psoriasis han revelado la importancia de IL-23 e IL-17 en la patogenia de las diferentes manifestaciones comunes a este grupo de enfermedades. Estos modelos también han mostrado la relevancia de otras células del sistema inmune innato además de las Th17, tanto de origen mieloide como linfoide, como productoras de IL-17. Además de los efectos proinflamatorios, estos modelos han evidenciado los efectos de IL-17 en la patogenia de las lesiones erosivas u osteoformativas asociadas a las espondiloartropatías

The relevance of interleukin (IL)-17 in the pathogenesis of spondyloarthritis has unquestionably been demonstrated by the therapeutic success of its antagonists. Animal models have provided useful information on the molecular and cellular pathways that implicate this route in these diseases. Mice that were deficient in different molecular components related to this pathway initially revealed the dependence of a number of inflammatory diseases on Th17 cells and on cytokines IL-17 and IL-23, modifying the previous TH1/th2 model. Animal models of autoimmune arthritis, colitis and encephalitis have been useful in that they demonstrate their dependence on T helper 17 (Th17) cells. In other models of arthritis, such as that induced by proteoglycans or antibodies (glucose-6-phosphate isomerase), neither Th17 cells nor IL-17 appear to be involved. Animal models of spondyloarthritis and of psoriasis revealed the importance of IL-23 and IL-17 in the pathogenesis of the distinct manifestations that are common to this group of diseases. These models have also shown the relevance of other cells of the innate immune system, including myeloid and lymphoid cells, as well as Th17, as the origin of IL-17. Aside from the proinflammatory effects, these models have displayed the effects of IL-17 in the pathogenesis of the erosive lesions or pathological bone formation associated with spondyloarthropathies

Feasibility of ultrasound-guided epidural access at the lumbo-sacral space in dogs.

Epidural injections are commonly performed blindly in veterinary medicine. The aims of this study were to describe the lumbosacral ultrasonographic anatomy and to assess the feasibility of an ultrasound-guided epidural injection technique in dogs. A cross sectional anatomic atlas of the lumbosacral region and ex vivo ultrasound images were obtained in two cadavers to describe the ultrasound anatomy and to identify the landmarks. Sixteen normal weight canine cadavers were used to establish two variations of the technique for direct ultrasound-guided injection, using spinal needles or epidural catheters. The technique was finally performed in two normal weight cadavers, in two overweight cadavers and in five live dogs with radiographic abnormalities resulting of the lumbosacral spine. Contrast medium was injected and CT was used to assess the success of the injection. The anatomic landmarks to carry out the procedure were the seventh lumbar vertebra, the iliac wings, and the first sacral vertebra. The target for directing the needle was the trapezoid-shaped echogenic zone between the contiguous articular facets of the lumbosacral vertebral canal visualized in a parasagittal plane. The spinal needle or epidural catheter was inserted in a 45° craniodorsal-caudoventral direction through the subcutaneous tissue and the interarcuate ligament until reaching the epidural space. CT examination confirmed the presence of contrast medium in the epidural space in 25/25 dogs, although a variable contamination of the subarachnoid space was also noted. Findings indicated that this ultrasound-guided epidural injection technique is feasible for normal weight and overweight dogs, with and without radiographic abnormalities of the spine.

Spondylitis in a humpback whale (Megaptera novaeangliae) from the southeast Pacific.

A 7.25 m long male humpback whale (Megaptera novaeangliae) with spondylitis was found beached on August 13, 1994 at Ancon, Ecuador (2 degrees 23' S, 80 degrees 47' W). The condition involved at least 11 vertebrae, 7 lumbar (L4 to L11) and 4 caudal (Ca1 to Ca4). Partial fusion of vertebrae was observed as a result of intervertebral bony proliferation, likely impeding full motion. The relatively young age of this specimen and the severity of the deformities suggest an infectious, rather than degenerative, process. The gross findings are most consistent with some type of spondyloarthritis. Although this condition has previously been identified in a number of cetacean species, the pathogenesis, population impact and ecologic implications have not been fully assessed. This is the third case described for humpback whales and the first for a humpback whale from the SE Pacific.

Inflammatory arthritis in canids: spondyloarthropathy.

Spondyloarthropathy was observed in 25 (2.8%) of 895 preserved canid museum specimens and was catalogued by species. The associated skeletal alterations in canids are indistinguishable grossly and physiologically from those in humans with spondyloarthropathy of the reactive type. Rate of affliction was independent of captive or wild-caught status or gender. In canids, spondyloarthropathy was much more common than osteoarthritis (0.3%), which predominantly is limited to captive animals. Animal well-being may be enhanced by recognition of the condition and initiation of specific treatment.