Arthrographic Study of the Communication between the Tarsal Joints in Crioulo Horses.

OBJECTIVE: The aim of the present study is to assess an arthrographic technique based on the access to the equine tarsus via distal intertarsal and on the existence and frequency of communication between distal and tarsocrural joints in the tarsus of Crioulo horses. MATERIALS AND METHODS: Fifty Crioulo horses of both sexes from 3 to 8 years old were included in the experiment. Animals with radiographic signs of tarsal osteoarthritis and joint space loss were excluded from the experiment. Contrast was injected in the distal intertarsal joint and radiographs were taken at two different times - Time 0 (after contrast application) and Time 1 (45 seconds after) to detect any communication between tarsal joints. The recorded results were analysed through chi-squared test. RESULTS: Thirty out of three hundred tarsi were excluded from the experiment since the radiographic images showed loss of the distal intertarsal joint space. Positive contrast was injected in distal intertarsal joint of 70/100 tarsi. There was not any contrast overflow in the 30/70 assessed tarsi. Contrast diffused to the tarsometatarsal joint in 32/70 of the assessed tarsi and reached tarsocrural joints in 8/70 tarsi. The adopted arthrographic technique was effective in data collection and evaluation; however, 52/70 of tarsi showed contrast overflow to the bursa of the cunean tendon. CLINICAL SIGNIFICANCE: The communication between tarsocrural and distal tarsal joints in Crioulo horses was significantly higher, and this finding emphasizes the importance of performing contrasted arthrography before getting to a final diagnostic and defining therapeutic procedures.

Heavy metal concentrations and biomarkers of oxidative stress in native mussels (Mytilus edulis chilensis) from Beagle Channel coast (Tierra del Fuego, Argentina).

The aim of this study was to evaluate the usefulness of oxidative stress biomarkers of pollution in native mussels Mytilus edulis chilensis from the Beagle Channel. Spatial and seasonal variations of catalase, glutathione-S-transferase and lipid peroxidation in gills and digestive gland were analyzed in relation to environmental parameters, heavy metals in sediment and in tissue. Four sites with anthropogenic impact and a control site were selected and monitored during the four seasons of 2007. We found significant differences among sites in concentrations of dissolved nutrients and heavy metals in sediments, with the highest values recorded at sites with anthropogenic pressure. Different patterns were observed between concentrations of metals in tissues and in sediments suggesting differences in bioavailability. There were also significant differences in biomarker responses among sites, despite the strong seasonal variability. Our results showed relatively moderate levels of pollution in the study area as a result of urban influences.

Biomarkers and heavy metal bioaccumulation in mussels transplanted to coastal waters of the Beagle Channel.

Mussels coming from a mussel farm at Brown Bay (Beagle Channel) were transplanted to four sites inside Ushuaia Bay for 2 and 4 weeks. The objective of this study was to assess the quality of coastal waters of Ushuaia Bay by measuring catalase activity, lipid peroxidation, total lipid content, bioaccumulation of heavy metals and condition index in transplanted mussel Mytilus edulis chilensis. Biomarkers except condition index showed significant differences among exposure times as well as among tissues. Digestive gland presented the highest catalase activity, malondialdehyde level and total lipid content. Digestive gland also was the main target tissue of accumulation of iron and copper, while gill accumulated the highest levels of zinc. A principal component analyzes with the whole set of data allowed to separate stations based on physicochemical conditions and biochemical responses of each studied area.