Characterization of a feline homologue of the alphaE integrin subunit (CD103) reveals high specificity for intra-epithelial lymphocytes

The characteristics of a feline homologue of the alphaE integrin (CD103), defined by two murine monoclonal antibodies, Fe7.1B8 (IgG1) and Fe7.2D8 (IgG1), are described. These antibodies recognized 75% of intra-epithelial (range 59-88%) and 40% of lamina proprial (range 28-46%) T cells of the intestinal mucosal tissue of the small intestine in contrast with approximately 2% of peripheral blood lymphocytes. Both antibodies immunoprecipitated a 180 kDa protein from biotinylated feline intra-epithelial mucosal leukocytes consistent with the alphaE integrin subunit in conjunction with a 120 kDa protein consistent with the beta7 subunit. The nucleotide sequence of feline alphaE integrin, generated from molecular cloning of the feline alphaE encoding cDNA, is also reported. This feline molecule shares 72% sequence homology with human and 69% homology with murine and rat counterparts. Homology includes the presence of an X (extra) domain, that appears unique to alphaE molecules as described for human, rat and mouse, as well as areas of homology common to other alpha integrins. Of note is a typical I (inserted) domain, the presence of seven repeat regions, and highly conserved sequences in the cytoplasmic tail. Transfection studies demonstrated that both antibodies recognized an extracellular component which encompassed the X and I domains of the cloned alphaE integrin subunit. These studies demonstrate that the pattern of tissue distribution, biochemical characteristics, and cDNA sequence of the feline alphaE integrin subunit are largely similar to that described for other species.     

Pre-operative fibrous osteodystrophy and severe,refractory, post-operative hypocalcemia following parathyroidectomy in a dog

A 13-year-old dog exhibited dramatic, radiographic osteopenia consistent with fibrous osteodystrophy secondary to primary hyperparathyroidism. Following parathyroidectomy, the dog developed severe, prolonged hypocalcemia, but was successfully treated and discharged 32 d after surgery. A variety of factors may have contributed to this dog’s hypocalcemia including hypoparathyroidism and hungry bone syndrome.     

Nasopharyngeal turbinates in brachycephalic dogs and cats

This retrospective study reports the presence and incidence of nasal turbinates in the nasopharynx (nasopharyngeal turbinates) in a population of brachycephalic dogs and cats exhibiting signs of upper respiratory disease. Medical records were reviewed for 53 brachycephalic dogs and 10 brachycephalic cats undergoing upper airway endoscopy. Nasopharyngeal turbinates were identified in 21% of brachycephalic animals, including 21% of dogs and 20% of cats. Pugs accounted for 32% of all dogs in the study population and 82% of dogs with nasopharyngeal turbinates. The presence of nasopharyngeal turbinates may play a role in upper airway obstruction in the brachycephalic airway syndrome.     

The effect of otic vehicle and concentration of dexamethasone on liver enzyme activities and adrenal function in small breed healthy dogs

Dexamethasone 0.1% in propylene glycol vehicle has been shown to cause adrenal suppression and increased liver enzyme concentrations in normal dogs. The objectives of this study were to determine if these effects are concentration or vehicle dependent and to evaluate a dexamethasone 0.01% solution. Twenty-one privately owned normal dogs were included in this double-blinded study. Chemistry panels and adrenocorticotropin hormone (ACTH) stimulation tests were performed on day 0 and 15. Dogs were randomly assigned treatment with dexamethasone 0.01% in saline, 0.1% in saline, or 0.1% in a commercial preparation (Tresaderm®: Merial, Duluth, GA, USA) in each ear twice daily for 2 weeks. Nineteen dogs completed the study. After 2 weeks of treatment, all dogs receiving dexamethasone 0.01% in saline had normal ACTH stimulation tests and liver enzyme values. In contrast, four of seven dogs (57.14%) receiving dexamethasone 0.1% in saline experienced adrenal suppression, and four of six dogs (66.67%) receiving Tresaderm® experienced adrenal suppression with three of those dogs (50%) experiencing marked adrenal suppression. No dogs receiving dexamethasone 0.1% in saline had increased liver enzyme concentration, while one of six dogs (16.67%) experienced a slight elevation in alkaline phosphatase. In conclusion, it appears that adrenal suppression caused by otic dexamethasone is concentration and perhaps vehicle dependent. Veterinarians who formulate dexamethasone 0.1% otic solutions should be cognizant of potential adrenal suppression similar to that seen with Tresaderm® although not to the same degree. Dexamethasone at 0.01% did not cause adrenal suppression or liver enzyme alterations after 2 weeks of treatment.     

Assessment of the cryopreservation of equine spermatozoa in the presence of enzyme scavengers and antioxidants

OBJECTIVE: To evaluate the effect of the addition of enzyme scavengers and antioxidants to the cryopreservation extender on characteristics of equine spermatozoa after freezing and thawing. SAMPLE POPULATION: 2 ejaculates collected from each of 5 stallions. PROCEDURE: Equine spermatozoa were cryopreserved in freezing extender alone (control samples) or with the addition of catalase (200 U/mL), superoxide dismutase (200 U/mL), reduced glutathione (10 mM), ascorbic acid (10 mM), alpha-tocopherol (25, 50, 100, or 500 microM or 1 mM), or the vehicle for alpha-tocopherol (0.5% ethanol). After thawing, spermatozoal motility was assessed via computer-assisted analysis and DNA fragmentation was assessed via the comet assay. Spermatozoal mitochondrial membrane potential, acrosomal integrity, and viability were determined by use of various specific staining techniques and flow cytometry. RESULTS: The addition of enzyme scavengers or antioxidants to cryopreservation extender did not improve spermatozoal motility, DNA fragmentation, acrosomal integrity, viability, or mitochondrial membrane potential after thawing. Superoxide dismutase increased DNA fragmentation, likely because of the additional oxidative stress caused by the generation of hydrogen peroxide by this enzyme. Interestingly, the addition of the vehicle for alpha-tocopherol resulted in a significant decrease in live acrosome-intact spermatozoa. CONCLUSIONS AND CLINICAL RELEVANCE: The addition of antioxidants to the cryopreservation extender did not improve the quality of equine spermatozoa after thawing, which suggests that the role of oxidative stress in cryopreservation-induced damage of equine spermatozoa requires further investigation. Our data suggest that solubilizing alpha-tocopherol in ethanol may affect spermatozoal viability; consequently, water-soluble analogues of alpha-tocopherol may be preferred for future investigations.