Retrospective application of a validated algorithm for estimation of adrenal gland volume after computed tomography on 46 dogs undergoing adrenalectomy.

Canine adrenal gland volume can be predicted based on body weight and computed tomography (CT) measurements using a validated algorithm. Use of this algorithm to detect adrenal pathology, including hyperplasia, hypoplasia and neoplasia, in clinical cases has not been described. The objective of this study was to illustrate application of the algorithm by estimating subject-specific adrenal gland volume in a historical cohort of dogs with known adrenal disease. Forty-six dogs that underwent CT and subsequent adrenalectomy were included. Clinical records and CT images from dogs that underwent adrenalectomy and histologic examination of the excised adrenal gland(s) were reviewed. Normal adrenal gland volumes for each dog were estimated using the algorithm, and compared with measured volumes of the affected glands. Linear measurement of the largest lesion diameter was also recorded. Fifty-eight adrenal glands were removed from 46 dogs, with pathology confirmed in all glands. Pathology included 28 adenomas, 13 carcinomas, 11 pheochromocytomas and 6 other benign pathologies. The volume of all removed adrenal glands was measured to be larger than the expected normal volume estimated by the algorithm, ranging from 1.1 to 212.9 times larger than estimated. Adrenal glands with malignant and benign pathology showed variable volumes with overlapping ranges recorded. Assessment of the dimensions of any focal lesion against a cut-off of 20 mm failed to discriminate malignancy. This study illustrates and supports the application of a validated volumetric algorithm for estimation of subject-specific adrenal gland volume to identify the presence of pathology and as a tool to assist clinical decision-making.

Clinical characteristics of two-hundred thirty-two dogs (2006-2018) treated for suspected anaphylaxis in Perth, Western Australia.

OBJECTIVE: To describe the clinical features of dogs treated for suspected anaphylaxis in Perth, Western Australia. DESIGN: Single-centre observational case series with retrospective and prospective phases. METHODS: This was a two-phase study of dogs with clinical suspicion of anaphylaxis presenting to the emergency service of a university teaching hospital. Dogs required evidence of, and appropriate treatment of, a type 1 hypersensitivity reaction as well as two or more organs affected (or cardiovascular signs alone) to be included. Phase 1 includes retrospective case series of 186 dogs (March 2006-December 2018). Phase 2 includes prospective descriptive case series of 46 dogs (October 2017-July 2018) focused on clinical signs. RESULTS: In phase 1, 88 (47%) dogs had evidence of insect exposure prior to the acute event. One hundred forty (75%) dogs had dermatological signs, 141 (76%) had gastrointestinal signs and 129 (69%) had cardiovascular signs. Ninety-two (49%) dogs had vasoconstrictive shock (5 with bradycardia), 24 (13%) had vasodilatory shock, 8 (4%) had mixed vasodilatory and vasoconstrictive shock and 5 (3%) had unclassifiable shock. On focused abdominal ultrasound, 42 of 71 (59%) dogs had gallbladder wall oedema and 3 of 71 (4%) dogs had peritoneal free fluid. In phase 2, the distributions of insect exposure, organ dysfunction and sonographic abnormalities were similar to phase 1. CONCLUSION: Dogs presenting with suspected anaphylaxis showed a broad range of presentations. Dermatological signs were absent in a proportion of dogs, vasoconstrictive shock was more frequent than vasodilatory and unique features of shock were identified. This study highlights the challenges of diagnosis based on presenting features alone.

Diagnostic imaging of migrating kebab (sosatie) sticks--a review of 8 cases.

Complications related to extraluminal migration of ingested kebab (sosatie) sticks are infrequently diagnosed in small animals. A total of 8 cases diagnosed with extragastric migration of ingested kebab sticks were retrospectively evaluated. No significant breed or sex predilection was found but there was a tendency for animals to present at a younger age (less than 3 years). Clinical signs (of variable duration) were non-specific and included haemoptysis, abdominal pain, regurgitation, subcutaneous abscessation and chronic draining sinus tracts, making a clinical diagnosis difficult. Ultrasonography proved invaluable in facilitating the diagnosis of kebab stick migration in 6 of the cases and computed tomography unexpectedly identified a kebab stick that had migrated into the thorax in 1 patient. Survey radiography was generally found to be insensitive in identifying the kebab sticks. The aim of this article is to alert veterinarians to a clinical syndrome that may not be considered a differential diagnosis in patients with non-specific inflammatory disease of the thorax, abdomen or pelvic regions and to illustrate the usefulness of the various diagnostic imaging modalities in facilitating a diagnosis of kebab stick ingestion and its possible secondary complications.

Evidence for Klein tunneling in graphene p-n junctions.

Transport through potential barriers in graphene is investigated using a set of metallic gates capacitively coupled to graphene to modulate the potential landscape. When a gate-induced potential step is steep enough, disorder becomes less important and the resistance across the step is in quantitative agreement with predictions of Klein tunneling of Dirac fermions up to a small correction. We also perform magnetoresistance measurements at low magnetic fields and compare them to recent predictions.

Incidence of canine elbow dysplasia in South Africa.

In South Africa, 1919 canine elbow dysplasia grading evaluations were performed from 1999-2006. Of these 1827 were evaluated by the senior author and form the basis of this article. Each report recorded the breed, age, sex, side affected and elbow dysplasia grading. The relationship between breed, age, sex, side affected, origin of radiographs and elbow dysplasia incidence was then analysed. Statistical evaluations were performed including means and standard deviations. The Rottweiler had the highest incidence of elbow dysplasia at 55 % followed by the Bullmastiff, Chow chow, Boerboel and Golden retriever, all of which had elbow dysplasia incidences of >38%. Males were significantly more affected than females. The incidence of elbow dysplasia in the various breeds was compared with those of the Orthopaedic Foundation for Animals in the United States and was found to be much higher in South Africa.

Transport measurements across a tunable potential barrier in graphene.

The peculiar nature of electron scattering in graphene is among many exciting theoretical predictions for the physical properties of this material. To investigate electron scattering properties in a graphene plane, we have created a gate-tunable potential barrier within a single-layer graphene sheet. We report measurements of electrical transport across this structure as the tunable barrier potential is swept through a range of heights. When the barrier is sufficiently strong to form a bipolar junction (n-p-n or p-n-p) within the graphene sheet, the resistance across the barrier sharply increases. We compare these results to predictions for both diffusive and ballistic transport, as the barrier rises on a length scale comparable to the mean free path. Finally, we show how a magnetic field modifies transport across the barrier.