Osteochondral Fragmentation in the Synovial Pad of the Fetlock in Warmblood Horses

Objectives— To determine clinical and arthroscopic characteristics associated with fragments in the synovial pad of the fetlock and to characterize their morphology. Study Design— Retrospective study. Animals— Warmblood horses (n=104) with fragment(s) in the synovial pad. Methods— S ignalment and results of radiographic and clinical examination were collected before surgery. After arthroscopic fragment removal and joint evaluation for synovial and/or cartilage abnormalities, fragments were measured, and evaluated by histopathology. Results— Synovial pad fragments (n=142) were removed from 127 fetlocks. Two older horses had lameness. During arthroscopy, abnormalities were observed in 40 joints (31.5%) and multivariate logistic regression analysis showed a significant correlation between the observed arthroscopic abnormalities and the presence of large fragments (P=.016). Fragments were osteochondral bodies completely surrounded by fibrous tissue. At the edges of the hyaline cartilage cap an underlying fibrous structure was obvious in the extracellular matrix giving it a reactive pattern. Conclusions— Although the impact on lameness was minimal, there was a significant correlation between arthroscopic abnormalities and presence of large synovial pad fragments. On histopathology, these osteochondral fragments are embedded in fibrous tissue and show a reactive pattern. They are not a manifestation of any well‐described joint pathology. Clinical Relevance— Large synovial pad fragments in Warmblood horses can be associated with synovial and cartilage abnormalities, but further studies are warranted to determine their origin and clinical importance.     

Video‐Assisted Thoracoscopic Resection of Noninvasive Thymomas Using One‐Lung Ventilation in Two Dogs

Objective— To report the technique and outcome of video‐assisted thoracoscopic surgery (VATS) for resection of cranial mediastinal thymoma in 2 dogs. Study Design— Case report. Animals— Eleven‐year‐old Labrador Retrievers (n=2). Methods— Two dogs had VATS resection of thymoma. Preoperative computed tomography (CT) scans revealed well‐circumscribed cranial mediastinal masses with dimensions of 4.5 cm × 4.2 cm × 3.7 cm and 2.1 cm × 2.1 cm × 4.1 cm (at the time of resection) without CT evidence of vascular invasion. One‐lung ventilation (OLV) was achieved using a bronchoscopically placed double‐lumen endobronchial tube. A 3‐portal technique was used for VATS access to the thorax. Thymomas were dissected from the tissues of the cranial mediastinum with the aid of a harmonic scalpel and retrieved in specimen retrieval bags. Results— Two cranial mediastinal thymomas were resected successfully, with their capsules intact, using a VATS technique. One dog developed aspiration pneumonia postoperatively which resolved with treatment and remains healthy 18 months postoperatively with no radiographic evidence of tumor recurrence. The second dog was diagnosed with myasthenia gravis, megaesophagus, and aspiration pneumonia preoperatively and despite recovering well from the procedure had a second episode of aspiration pneumonia 5 days postoperatively and was euthanatized. Conclusions— VATS resection of modestly sized noninvasive thymoma is possible in dogs. Careful case selection and preoperative imaging are the keys. Clinical Relevance— Thoracoscopic resection of modestly sized mediastinal masses forms part of an increasingly expansive set of indications for minimally invasive surgery in select veterinary patients.     

Antioxidant supplementation,effect on post‐thaw spermatozoan function in three sturgeon species

High levels of reactive oxygen species (ROS), which may be associated with reduced sperm quality, can be detected during cryopreservation of sperm of some species. Our objective was to investigate whether the addition of antioxidants to cryopreservation extenders influenced post‐thaw sperm characteristics and fertility in Acipenser dabryanus, Acipenser sinensis and Acipenser baerii. Prior to freezing, sperm samples were diluted with a base extender as control or in extender supplemented with catalase (CAT), glutathione (GSH), cysteine (NAC), ascorbic acid (VC) or their paired combinations. Protective concentrations of CAT, GSH and VC in the three species were 25 U/ml, 0.25‐0.5 mg/ml and 0.5 mg/ml, respectively. Cysteine showed no protective effect against ROS. The addition of CAT, GSH and VC positively affected either acrosome or membrane integrity of post‐thawed sperm in the three species, as well as spermatozoan motility in A. sinensis. The combination of antioxidants did not show a positive synergistic effect. This study suggested that the use of antioxidants in the cryopreservation of sturgeon sperm has potential to decrease intracellular ROS, and consequently preserve acrosome and membrane integrity, as well as spermatozoan motility.     

Comparison of the bordered pits of two species of spruce (Pinaceae) in a green and kiln-dried condition and their effects on fluid flow in the stem wood in relation to wood preservation

The relationship between bordered pit aspiration, pit sizesand permeability measured as preservative uptake and expressedas porosity was examined in two species of spruce, Sitka spruce(Picea sitchensis (Bong.) Carr.) grown in the UK and Easternspruce (Picea orientalis (L.) Link.) grown in Turkey, before(in the freshly felled green condition) and after kiln drying.A 2.5 per cent chromated copper arsenate preservative solutionwas allowed to flow in either the longitudinal or tangentialdirection of the stem wood and the uptake was assessed. Borderedpit anatomy was examined by light and scanning electron microscopyand image analysis was used to characterize the samples. Thepermeability of the wood declined following drying but lessso in the Sitka spruce. From an analysis of measurements madeon the wood features it appeared that basic density, latewoodpercentage and degree of pit aspiration were the most importantfeatures explaining these results. The structure of the borderedpits varied between the two species and the relative size ofthe aperture in comparison with the pit chambers was greaterin the Eastern spruce. The effects of these and other variablesincluding differences in conventional drying systems and naturaltree responses to environmental conditions on pit behaviouraffecting permeability are discussed.     

Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density

Background

Recent studies of anadromous salmon (Oncorhynchus spp.) on the Pacific Coast of North America indicate an important and previously unrecognized role of salmonid nutrients to terrestrial biota. However, the extent of this uptake by primary producers and consumers and the influences on community structure remain poorly described. We examine here the contribution of salmon nutrients to multiple taxa of riparian vegetation (Blechnum spicant, Menziesii ferruginea, Oplopanax horridus, Rubus spectabilis, Vaccinium alaskaense, V. parvifolium, Tsuga heterophylla) and measure foliar δ¹⁵N, total %N and plant community structure at two geographically separated watersheds in coastal British Columbia. To reduce potentially confounding effects of precipitation, substrate and other abiotic variables, we made comparisons across a sharp ecological boundary of salmon density that resulted from a waterfall barrier to salmon migration.

Results

δ¹⁵N and %N in foliage, and %cover of soil nitrogen indicators differed across the waterfall barrier to salmon at each watershed. δ¹⁵N values were enriched by 1.4‰ to 9.0‰ below the falls depending on species and watershed, providing a relative contribution of marine-derived nitrogen (MDN) to vegetation of 10% to 60%. %N in foliar tissues was slightly higher below the falls, with the majority of variance occurring between vegetation species. Community structure also differed with higher incidence of nitrogen-rich soil indicator species below the waterfalls.

Conclusions

Measures of δ¹⁵N, %N and vegetation cover indicate a consistent difference in the riparian community across a sharp ecological boundary of salmon density. The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access. This, in turn, may have cascading ecosystem effects in forests adjacent to salmon streams.