Immune regulation of canine tumour and macrophage PD‐L1 expression

Expression of programmed cell death receptor ligand 1 (PD‐L1) on tumor cells has been associated with immune escape in human and murine cancers, but little is known regarding the immune regulation of PD‐L1 expression by tumor cells and tumor‐infiltrating macrophages in dogs. Therefore, 14 canine tumor cell lines, as well as primary cultures of canine monocytes and macrophages, were evaluated for constitutive PD‐L1 expression and for responsiveness to immune stimuli. We found that PD‐L1 was expressed constitutively on all canine tumor cell lines evaluated, although the levels of basal expression were very variable. Significant upregulation of PD‐L1 expression by all tumor cell lines was observed following IFN‐γ exposure and by exposure to a TLR3 ligand. Canine monocytes and monocyte‐derived macrophages did not express PD‐L1 constitutively, but did significantly upregulate expression following treatment with IFN‐γ. These findings suggest that most canine tumors express PD‐L1 constitutively and that both innate and adaptive immune stimuli can further upregulate PD‐L1 expression. Therefore the upregulation of PD‐L1 expression by tumor cells and by tumor‐infiltrating macrophages in response to cytokines such as IFN‐γ may represent an important mechanism of tumor‐mediated T‐cell suppression in dogs as well as in humans.     

Water vapour diffusion and adsorption characteristics of sugar maple (Acer saccharum,Marsh.) wood polymer composites

Summary Water vapour diffusion characteristics and adsorption isotherms were determined for cell-lumen and cell-wall treated wood polymer composites (WPC). The diffusion coefficients of the cell-lumen WPC were lower than untreated wood and the cell-wall WPC coefficients were lower than cell-lumen. Using the Hailwood and Horrobin sorption model, it was found that the unimolecular layer is formed at lower moisture contents in WPC than in wood. The amount of free dissolved water was reduced only in the cell-wall WPC. The polymer reduces the water vapour accessibility in both types of WPC.     

Surgical management of cicatricial ectropion following scarring dermatopathies in two dogs

Two dogs were presented with severe dermatopathies leading to cicatricial ectropion and severe surface ocular pathology. In one case, idiopathic sterile pyogranuloma was diagnosed on histopathology and managed with systemic immunosuppressive therapy. In the second case, demodicosis was diagnosed on skin scrapings and successfully treated with acaricidal medication. Following control of the underlying dermatopathies, both cases developed cicatricial ectropion as a result of scarring and contracture of eyelid tissue. Wharton-Jones (V-Y) blepharoplasties were performed on the affected eyelids and resulted in improved eyelid function and reduced corneal exposure in both cases.     

Spinal spondylosis and acute intervertebral disc prolapse in a European brown bear (Ursus arctos arctos)

A 22-year-old male European brown bear (Ursus arctos arctos) was presented to the Onderstepoort Veterinary Academic Hospital after an acute onset of hind limb paralysis 4 days earlier. Previous radiographs revealed marked degenerative joint disease of the stifles, tarsi and digits. The clinical findings were consistent with acute disc prolapse. Lateral radiographs of the entire vertebral column were made as well as ventrodorsal pelvic radiographs. The latter were within normal limits. The vertebral column revealed multiple lesions consistent with chronic and acute disc herniations. Lateral compression of the caudal lumbar nerve roots could not be ruled out. Owing to multiple significant findings of the vertebral column and the poor prognosis for full recovery after surgery, the bear was euthanased. The diagnosis of an acute disc prolapse and multiple chronic disc herniations was confirmed on necropsy.     

Nitrate leaching and residual soil nitrogen supply following outdoor pig farming

Abstract. Large nitrogen (N) inputs to outdoor pig farms in the UK can lead to high nitrate leaching losses and accumulation of surplus N in soil. We investigated the residual effects of three contrasting outdoor pig systems as compared to an arable control on nitrate leaching and soil N supply for subsequent spring cereal crops grown on a sandy loam soil during 1997/98 and 1998/99 harvest seasons. Previously, the pig systems had been stocked for 2 years from October 1995 and were designated current commercial practice (CCP, 25 sows ha^?1 on stubble), improved management practice (IMP, 18 sows ha^?1 on undersown stubble) and best management practice (BMP, 12 sows ha^?1 on established grass). Estimated soil N surpluses by the end of stocking in September 1997 were 576, 398, 265 and 27 kg ha^?1 N for the CCP, IMP, BMP and continuous arable control, respectively. Nitrate leaching losses in the first winter were 235, 198, 137 and 38 kg ha^?1 N from the former CCP, IMP and BMP systems and the arable control, respectively. These losses from the former pig systems were equivalent to 41–52% of the estimated soil N surpluses. Leaching losses were much smaller in the second winter at 21, 14, 23 and 19 kg ha^?1 N, respectively. Cultivation timing had no effect (P>0.05) on leaching losses in year 1, but cultivation in October compared with December increased nitrate leaching by a mean of 14 kg ha^?1 N across all treatments in year 2. Leaching losses over the two winters were correlated (P<0.001) with autumn soil mineral N (SMN) contents. In both seasons, spring SMN, grain yields and N offtakes at harvest were similar (P>0.05) for the three previous pig systems and the arable control, and cultivation timing had no effect (P>0.05) on grain yields and crop N offtake. This systems study has shown that nitrate leaching losses during the first winter after outdoor pig farming can be large, with no residual available N benefits to following cereal crops unless that first winter is much drier than average.     

CASE REPORT: Unilateral eyelid lesion and ophthalmologic findings in an aardvark (Orycteropus afer): case report and literature review

Objective To summarize the medical knowledge surrounding aardvarks to date, to describe the ophthalmic examination of a specimen with a chronic history of an upper eyelid lesion, of an assumed blind left eye, and to detail the anesthesia procedure performed. Procedure A 23‐year‐old aardvark was examined under general anesthesia and multiple ocular abnormalities were detected in the left eye (globe deviation, corneal opacities, iridodonesis, and aphakia). A thickening of the palpebral conjunctiva affecting the medial upper eyelid with erosion of the normal eyelid margin anatomy was identified. The adnexal lesion was resected by a wedge resection and histopathology was performed. Suture breakdown 3 days postoperatively required a second surgery, where buried sutures were used. The surgical techniques and postoperative care are discussed. Results The histopathology revealed mucosal hyperplasia and moderate neutrophilic and lymphoplasmacytic blepharitis. No causal organisms were identified. Following initial wound dehiscence and a modified surgical technique, the upper eyelid healed without complication and retained complete function. Conclusions The eyelid lesion involved a benign inflammatory and hyperplastic pathology of unknown etiology. Adjusting routine ophthalmic surgical techniques to wildlife and zoo animals can be challenging and complicated. It is important to understand the nature of the animals being managed, their circadian cycle, and habitat, to adjust and individualize the surgical approach, instrumentation, suture material, and perioperative treatment.