Sonographic features of gastrointestinal lymphoma in 15 dogs.

OBJECTIVES: The purpose of this study is to describe the sonographic appearance of lymphoma of the gastrointestinal tract in dogs. METHOD: A retrospective review was conducted and patients with gastrointestinal lymphoma diagnosed by histopathology (including immunohistochemistry, where available) or cytology that had an abdominal ultrasound were included. RESULTS: Four of 15 (26·7%) cases with histopathologically confirmed lymphoma exhibited no sonographic abnormalities. In the dogs with sonographic abnormalities, features including intestinal wall thickness and the presence or absence of wall layering were highly variable. Clinical signs pertaining to the gastrointestinal tract were also unreliable markers of gastrointestinal lymphoma, with weight loss, vomiting, and diarrhoea being uncommon presenting complaints; intestinal obstruction was not present in any patient. CLINICAL SIGNIFICANCE: The sonographic appearance of gastrointestinal lymphoma in dogs is non-specific. Gastrointestinal lymphoma in dogs should be maintained as a differential diagnosis despite a sonographically normal appearing bowel.

Clotrimazole and enilconazole distribution within the frontal sinuses and nasal cavity of nine dogs with sinonasal aspergillosis.

OBJECTIVES: Multiple topical treatments are often required for clinical cure of mycotic rhinosinusitis in dogs. The objective of this study was to describe the distribution and retention of enilconazole and clotrimazole solutions using a temporary trephination protocol. METHODS: Nine client-owned dogs diagnosed with mycotic rhinosinusitis between March 2008 and December 2009 were prospectively enrolled and were sequentially allocated to receive treatment with either clotrimazole (1% in polyethylene glycol) or enilconazole (10% solution), after imaging and rhinoscopic assessment. Both frontal sinuses were trephined, debrided and flushed with saline. Infusion was administered via frontal sinuses with dogs in sternal recumbency and computed tomography (CT) performed 5 minutes after completion. Distribution was scored 1 to 4 at the canine tooth, premolar 4, cribriform plate and frontal sinus on both sides, for a maximum score of 32. RESULTS: Distribution of antifungal agents to all regions of the nasal cavity and frontal sinuses was achievable, but varied considerably. Retention was poor in 10 of 18 regions assessed. CLINICAL SIGNIFICANCE: Distribution of antifungal agents within the frontal sinuses is achievable using temporary trephination; however, distribution is variable and retention is often poor.

Computed tomography diagnosis of eight dogs with brain infarction.

OBJECTIVE: Medical records of eight dogs presenting with acute onset of neurological signs and a diagnosis of brain infarction as determined by computed tomography (CT) imaging were reviewed. DESIGN: Retrospective single-centre case review. RESULTS: Ischaemic infarction in the territory of the rostral cerebellar artery was identified in three spaniel-breed dogs. All cerebellar infarcts were non-haemorrhagic. Telencephalic infarcts were identified in five dogs, in the territories of the middle cerebral artery (2/5) and rostral cerebral artery (3/5). One of these dogs had an ischaemic infarction, but all other infarctions appeared haemorrhagic. All dogs were geriatric (≥ 8 years old), with concurrent medical conditions identified in six dogs. One dog was euthanased after diagnosis because of the severity of its neurological signs and one dog was euthanased as a result of associated renal disease 2 months after diagnosis. Six dogs were alive at least 1 year after diagnosis. CONCLUSIONS: CT is useful in the diagnosis of cerebrovascular accident in dogs, which can present as a spectrum of images with early changes in attenuation and subtle mass effects detected after infarction. CT is particularly sensitive for detecting haemorrhagic infarction, but under-represent ischaemic and lacunar infarctions when compared with MRI.

Nonsurgical treatment of gastroesophageal intussusception in a puppy.

A 7-week-old, female Siberian husky was presented to Murdoch University Veterinary Hospital with an acute onset of respiratory distress and regurgitation. Thoracic imaging identified an intraluminal esophageal mass with concurrent aspiration pneumonia. Esophagoscopy identified the mass as stomach, and a diagnosis of gastroesophageal intussusception was made. The intussusception was reduced endoscopically, and fixation of the stomach to the abdominal wall was performed using a tube gastropexy. Gastroesophageal intussusception is an uncommon disease in small animals and traditionally has been managed surgically. This case report describes an alternative method of treatment associated with a good outcome in this puppy.

Extradural haematoma secondary to brown snake (Pseudonaja species) envenomation.

A 4-year-old Siberian Husky dog was treated with brown snake antivenom by his regular veterinarian after a witnessed episode of brown snake envenomation. The dog was discharged 5 hours post presentation despite an ongoing coagulopathy. The dog was presented to the emergency centre 2 hours later because the owner believed the dog to be in pain. Initial examination revealed an ambulatory but neurologically normal patient with thoracolumbar pain and laboratory evidence of a coagulopathy. Despite correction of the coagulopathy, the signs progressed to bilateral hind limb paresis after approximately 3 hours of hospitalisation, and continued to deteriorate over the next 56 hours to loss of deep pain perception in the right hind limb. Computed tomography imaging identified the presence of an extradural haematoma which was subsequently removed via a hemilaminectomy. Surgical decompression was successful in treating the spinal compression and the dog recovered with minimal complications. To our knowledge this is the first report of extradural haematoma secondary to coagulopathy induced by brown snake envenomation.

Persistent isolated hypocortisolism following brief treatment with trilostane.

A 12-year-old male neutered Miniature Poodle with confirmed pituitary-dependent hyperadrenocorticism was treated with trilostane. After three doses, it developed clinical and laboratory changes suggestive of isolated hypocortisolism ('atypical hypoadrenocorticism'), which persisted and progressed for more than 3 months despite immediate withdrawal of the trilostane. The clinical signs of hyperadrenocorticism resolved without further trilostane. After 3 months, prednisolone treatment was started and the clinical signs of hypocortisolism resolved. Prednisolone therapy was required for more than 1 year. Ultrasonography initially demonstrated large hypoechoic adrenal cortices, typical of dogs with hyperadrenocorticism, which then became small and heteroechoic, consistent with the development of adrenal necrosis. Persistent isolated hypocortisolism has not been reported previously as a complication of trilostane therapy. The case is also remarkable for the very short duration of trilostane therapy that elicited this complication. Clinicians should be aware that trilostane therapy may result in adrenal necrosis, even in the very earliest stages of therapy, but prompt action can prevent a life-threatening situation.

Severe haemoptysis associated with seizures in a dog.

CASE HISTORY: A 7-year-old, sterilised male German Shepherd dog was presented with a history of three episodes of severe haemoptysis and associated dyspnoea within a 3-week period. A generalised tonic-clonic seizure was witnessed preceding the third episode. CLINICAL FINDINGS: Thoracic radiographs revealed a severe bilateral alveolar lung pattern of the caudodorsal lung fields; extension into the left cranial lung lobe was present but pulmonary vessels were within normal size limits. Frank blood was the only abnormality present at bronchoscopy. A coagulation profile, parasitological screening, thoracic and brain computed tomography (CT), and cerebrospinal fluid (CSF) cytological analysis did not identify any abnormalities. DIAGNOSIS: Haemoptysis due to either severe neurogenic pulmonary oedema or rupture of the pulmonary capillaries secondary to seizures was considered a possible diagnosis. The primary generalised seizures were attributed to late-onset idiopathic epilepsy diagnosed by exclusion of other causes. CLINICAL RELEVANCE: This is the first known case report describing severe haemoptysis associated with seizures in a dog.

Accuracy of prediction of canine litter size and gestational age with ultrasound.

Different sonographic criteria have been developed to estimate canine fetal age, including fetal mensuration and assessment of fetal organ development. This retrospective study assessed the accuracy of gestational age and litter size predictions in 76 bitches using one of two techniques. The first method used the differential features of fetal organ development that occur in early and mid pregnancy, based on published tables for beagles. The second method used biparietal head and trunk diameters to predict gestational age based on tables published for late gestational Labrador Retrievers. The accuracy of the two methods was compared and the effect of maternal body weight and litter size evaluated. Litter size and maternal body weight did not affect the accuracy of gestational age prediction. Using a combination of both methods, the overall accuracy of predicting parturition date within 65 +/- 1 day and +/- 2 days was 70.8% and 86.1%, respectively. The correct litter size was predicted in 65% of cases, and in 89.5% of cases for +/- 1 pup. Pearson's correlation between actual litter size and predicted litter size was high (R = 0.957, P < 0.001). The organ development method of predicting gestational age was more accurate than late gestational fetal mensuration (P = 0.019). The optimum time for sonographic estimation of fetal age and litter size is early and mid pregnancy.

Disseminated cryptococcosis including osteomyelitis in a horse.

A 4-year-old Arab mare was diagnosed with disseminated cryptococcosis, including osteomyelitis of the proximal phalanx of the left hind limb, osteomyelitis with associated soft tissue granuloma of a rib and disseminated, large cryptococcal nodules in the lungs. The lesion in the dorsoproximal aspect of the proximal phalanx had a large area of cortical lysis with spiculated periosteal new bone and extensive soft tissue swelling. The affected rib had a pathological fracture. Cryptococcal osteomyelitis has not been previously reported in horses but should be considered as a differential diagnosis, particularly in endemic regions.

Determinants of baroreflex function in juvenile end-stage renal disease.

Arterial baroreflex sensitivity (BRS) is markedly reduced in middle-aged patients with end-stage renal disease (ESRD), due to the combined effects of aging, arterial stiffening, and autonomic neuropathy. Much less is known about the effects of ESRD on arterial baroreflex in juvenile patients. Therefore, we investigated baroreflex function and its relation to carotid artery elasticity and heart rate variability in children and young adults with ESRD. We studied 42 subjects (9-30 years): 14 patients on maintenance hemodialysis (HD), 14 renal transplant recipients (RT), and 14 healthy control subjects (C). Baroreflex function was determined by pharmacological (BRS) and spontaneous (sequence and spectral indices) techniques. Carotid artery elasticity was characterized by stiffness index beta. Heart rate variability was assessed using time and frequency domain measures. Data are expressed as mean+/-s.d. BRS was markedly reduced in HD as compared to C (10.0+/-4.2 vs 25.7+/-5.9 ms/mm Hg); spontaneous indices were reduced to similar extent. Carotid artery stiffness was approximately 50% higher in HD than in C and was inversely related to BRS. Heart rate variability was also compromised in HD, and was directly related to spontaneous indices. No significant differences existed in any of these variables between RT and C. Decreased baroreflex function in juvenile HD is partly due to loss of carotid artery elasticity and partly due to impaired heart rate variability. Renal transplantation may partly prevent impairment or improve compromised baroreflex function in young patients with ESRD.

Impaired baroreflex function during pregnancy is associated with stiffening of the carotid artery.

OBJECTIVE: The baroreflex sensitivity and the distensibility of the carotid artery were measured during normotensive pregnancy to test the hypothesis that changes in baroreflex sensitivity are related to carotid artery stiffening. DESIGN: Data were obtained from pregnant subjects during each trimester (T1, T2, T3; n = 23) and postpartum (n = 11). End-diastolic diameter and pulsatile distension of the carotid artery were measured with an ultrasound wall-tracking system, and the distensibility coefficient was calculated. Spontaneous fluctuations in cardiac interval and systolic pressure were used to determine baroreflex sensitivity. RESULTS: Both distensibility coefficient and baroreflex sensitivity were reduced from T1 to T3 (5.1 +/- 1.6 vs. 3.7 +/- 0.9 10(-3)/mmHg and 10.1 +/- 2.9 vs. 5.7 +/- 1.8 ms/mmHg, respectively). Baroreflex sensitivity and carotid distensibility coefficient were linearly related in each subject (r = 0.62 +/- 0.12). Augmentation index and return time changes indicated a global increase in arterial distensibility. CONCLUSIONS: Stiffening of the carotid artery significantly contributes to the impairment of baroreflex sensitivity during pregnancy, and represents a region specific change as global arterial distensibility was found to increase during pregnancy.

Comparison of aortic arch and carotid sinus distensibility in humans--relation to baroreflex sensitivity.

We compared aortic arch (AA) and carotid sinus (CS) distensibility, and determined the relationship between baroreflex sensitivity (BRS) and distensibility coefficients of AA and CS (DCAA and DCCS, respectively). In 47 healthy 19-71-year-old subjects, AA and CS end-diastolic diameter (D) and pulsatile distension (delta D) was measured with ultrasound and arterial pressure by sphygmomanometer and Finapres. DC was calculated as 2delta D/(D x delta P), where delta P is the pulse pressure. BRS was determined by the sequence method. Data are given as mean +/- S.D.; significance was set at p < 0.05. DCAA and DCCS were linearly related across subjects (r = 0.80, p < 0.001). No difference between DCAA and DCCS (3.8 +/- 1.4 x 10(-3) and 4.2 + 2.2 x 10(-3) mm Hg(-1), respectively) was found for all subjects (paired t-test). However, at ages < 35 years, DCCS exceeded DCAA, whereas this relation was reversed at ages > 35 years. Age accounted for 53% of variability in DCAA and 73% of variability in DCCS. BRS was related to DC (linear regression), with the BRS-DCAA relation being steeper and closer (r = 0.73, p < 0.001) than the BRS-DCCS relation (r = 0.54, p < 0.05). It is suggested that aortic baroreceptors may have a dominant role in heart rate control.

Measurement of aortic arch distension wave with the echo-track technique.

The aim of this study was to use the echo-track method for measuring aortic arch diameter, distension waveform and elastic parameters. Data were obtained from 50 healthy volunteers of 32 +/- 15 y (mean +/- 1 SD). The aortic arch was interrogated from the suprasternal position with M-mode ultrasonography using a 3.5-MHz transducer; diameter and distension waves were determined by means of an echo-track algorithm (WTS, Pie Medical); arterial blood pressure was measured in the arm with sphygmomanometry. Aortic arch diameter, distension, distensibility and compliance were 24.55 +/- 2.99 mm, 2199 +/- 726 micrometer, 3.9 +/- 1.4. 10(-3) mmHg(-1) and 1.86 +/- 0.61 mm(2). mmHg(-1), respectively. Intrasession, interobserver and intersession variability was less than 10%, 10% and 18%, respectively. It is concluded that aortic arch distension wave can be recorded noninvasively with acceptable reproducibility, allowing assessment of aortic elastic parameters, and yielding insight into pressure wave reflection within the arterial system.

Static versus dynamic distensibility of the carotid artery in humans.

In clinical studies, the elastic behavior of central arteries is usually assessed by measuring dynamic distensibility. In this study, we aimed to investigate how dynamic and static distensibility of the common carotid artery (D(dyn) and D(stat), respectively) are related in 28 healthy volunteers of 20-71 years. The carotid diameter and its change with the pressure pulse were measured using an ultrasound echo-tracking device. Arterial blood pressure was measured by Finapres and carotid pressure was determined by applanation tonometry. D(dyn) was determined at rest using the pressure pulse, while D(stat) was determined during pressor responses induced by handgrip or cold pressor test. Data are given as mean +/- 1 SD. In younger subjects (<35 years), D(stat) did not differ from D(dyn) (7.0 +/- 3.4 vs. 6.5 +/- 2.1 x 10(-3) x mm Hg(-1), respectively), whereas in older subjects (>35 years), D(stat) was significantly higher than D(dyn) (3.8 +/- 1.4 vs. 2.1 +/- 0.9 x 10(-3) x mm Hg(-1), p < 0.001). For all subjects, D(stat) and D(dyn) decreased with increasing age and mean arterial pressure (MAP). Using stepwise multiple regression analysis, the strongest predictor of D(stat) proved to be MAP, while that of D(dyn) was age. D(stat) was found to be linearly related to the hysteresis loop area of the pressure-diameter relation (r = 0. 94), i.e. to vessel wall viscosity. It is concluded that, with increasing age, static distensibility overestimates the distension capacity of large arteries.

Assessment of the viscosity of the pulmonary artery wall.

Large artery wall viscosity reduces the efficiency of heart/vessel coupling. The aim of the present study was to assess pulmonary artery wall viscosity through comparison of the static (Dst) and dynamic distensibility (Ddyn) of the vessel wall. Right pulmonary artery pressure and diameter was measured in 13 patients and eight healthy volunteers. Ddyn was calculated as the relative change in end-diastolic diameter induced by the pressure pulse, and Dst as the relative change in mean diameter induced by the change in mean pressure during steady-state exercise. Dst did not differ significantly from Ddyn (mean+/-SD 22.8+/-19.2 versus 21.0+/-18.3 10(-3) mmHg(-1)), as tested by paired t-test and analysis of covariance, with age as covariant. End-diastolic diameter increased, whereas Dst and Ddyn decreased as a function of age (r=-0.69 and -0.67, respectively; p<0.01 for both). Ddyn did not change from rest to exercise in spite of a 23+/-16-beats-min(-1) increase in cardiac frequency. Pulmonary artery wall viscosity was negligible and no increase in wall viscosity occurred during cardioacceleration.

A tyrosine-phosphorylated protein that binds to an important regulatory region on the cool family of p21-activated kinase-binding proteins.

The p21-activated kinases (Pak) are major targets of the small GTPases Cdc42 and Rac. We, and others, recently identified a family of proteins termed Cool/Pix, which interact with Pak3. In cells, p50(Cool-1) suppresses Pak activation by upstream activators; p85(Cool-1) has a permissive effect on Pak activation, and we now show that the closely related Cool-2 stimulates Pak kinase activity. To understand the differential regulation of Pak by Cool proteins, we screened for Cool-interacting proteins by affinity purification and microsequencing. This has led to the identification of two closely related proteins called Cat (Cool-associated, tyrosine phosphorylated), which contain a zinc finger followed by three ankyrin repeats. Cat-1 is identical to the recently identified binding partner for the beta-adrenergic receptor kinase (betaARK or GRK-2), which was shown to have Arf-GAP activity. Cat-1 and Cat-2 both bind to the COOH-terminal region of p85(Cool-1) and p85(Cool-2) but do not bind to p50(Cool-1). Cat-1 is tyrosine-phosphorylated in growing NIH 3T3 fibroblasts, and its tyrosine phosphorylation is increased following cell spreading on fibronectin, decreased in cells arrested in mitosis, and increased in the ensuing G(1) phase. Cat proteins are tyrosine-phosphorylated when co-expressed in cells with the focal adhesion kinase Fak and Src. These findings suggest that in addition to playing a role in Cool/Pak interactions, Cat proteins may serve as points of convergence between G protein-coupled receptors, integrins, Arf GTPases, cell cycle regulators, and Cdc42/Rac/Pak signaling pathways.